235 results on '"Jian-xin Zhang"'
Search Results
2. Ligand-enabled Ni-catalysed enantioconvergent intermolecular Alkyl-Alkyl cross-coupling between distinct Alkyl halides
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Wen-Tao Zhao, Jian-Xin Zhang, Bi-Hong Chen, and Wei Shu
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Multidisciplinary ,General Physics and Astronomy ,General Chemistry ,General Biochemistry, Genetics and Molecular Biology - Abstract
α-Tertiary aliphatic amides are key elements in organic molecules, which are abundantly present in natural products, pharmaceuticals, agrochemicals, and functional organic materials. Enantioconvergent alkyl-alkyl bond-forming process is one of the most straightforward and efficient, yet highly challenging ways to build such stereogenic carbon centers. Herein, we report an enantioselective alkyl-alkyl cross-coupling between two different alkyl electrophiles to access α-tertiary aliphatic amides. With a newly-developed chiral tridentate ligand, two distinct alkyl halides were successfully cross-coupled together to forge an alkyl-alkyl bond enantioselectively under reductive conditions. Mechanistic investigations reveal that one alkyl halides exclusively undergo oxidative addition with nickel versus in-situ formation of alkyl zinc reagents from the other alkyl halides, rendering formal reductive alkyl-alkyl cross-coupling from easily available alkyl electrophiles without preformation of organometallic reagents.
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- 2023
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3. Ni-Catalyzed Reductive 1,2-Cross-Dialkylation of Unactivated Alkenes with Two Alkyl Bromides
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Jian-Xin Zhang and Wei Shu
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Bromides ,Organic Chemistry ,Alkenes ,Physical and Theoretical Chemistry ,Biochemistry ,Catalysis - Abstract
Cross-dialkylation of unactivated alkenes represents a significant challenge due to competitive β-hydride elimination and associated selectivity issues. Herein, a Ni-catalyzed reductive 1,2-dialkylation of unactivated aliphatic alkenes has been developed using two different alkyl bromides. The reaction proceeds smoothly under mild conditions to install two C
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- 2022
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4. Regio- and Enantioselective Hydroalkylations of Unactivated Olefins Enabled by Nickel Catalysis: Reaction Development and Mechanistic Insights
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Peng-Fei Yang, Lei Zhu, Jian-Xing Liang, Han-Tong Zhao, Jian-Xin Zhang, Xian-Wang Zeng, Qin Ouyang, and Wei Shu
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General Chemistry ,Catalysis - Published
- 2022
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5. Positive Osteocalcin Expressions in Periodontium Regenerated by Nano Bioceramics after Orthodontic Tooth Movement
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Lan Lei Wang, Jian Xin Zhang, Yuan Li, and Sai Nan Zhao
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stomatognathic diseases ,stomatognathic system ,Mechanics of Materials ,Mechanical Engineering ,General Materials Science - Abstract
The research is to analyse the immunohistochemical reaction of orthodontic force on the periodontium reformed by nanobiphasic calcium phosphate ceramics (nBCP). Two third incisors were selected randomly and operated as experimental groups in 2 Beagle dogs. In the labial aspects of the third incisors, alveolar bone defects were surgically made and implanted with NBCP. The contralateral teeth in the same jaw did not receive any treatment as control. After 24 weeks, all the third incisors were moved labially. The dogs were euthanized 4 weeks later. The expression levels of osteocalcin were detected by immunohistochemical staining. Positive osteocalcin expressions in regenerated periodontium were observed and compared with the normal periodontium in the control groups. There were no significant differences within and between them. It means the periodontium regenerated by nBCP can bear orthodontic forces with a normal function. Based on these findings, we concluded that nBCP may offer a new bone graft choice for periodontic disease patients who have demands for orthodontic treatment.
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- 2022
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6. Pore Structure Characteristics and Permeability Analysis of Natural Anhydrate with Various Water /Anhydrite Ratios Based on Mercury Intrusion Porosimetry
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Lu Zeng, Jia-Yang Zhu, Yu Zhao, Shu-Ping Wang, Hong Huang, Jian-Xin Zhang, and Jian-Xiong Ye
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- 2023
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7. Myocardial Work Measurement With Functional Capacity Evaluation in Primary Systemic Hypertension Patients: Comparison Between Left Ventricle With and Without Hypertrophy
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Hong Ran, Xiao-wu Ma, Lin-lin Wan, Jun-yi Ren, Jian-xin Zhang, Ping-yang Zhang, and Matthias Schneider
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Pulmonary and Respiratory Medicine ,Radiology, Nuclear Medicine and imaging - Abstract
Noninvasive measurement of myocardial work (MW) incorporates left ventricular (LV) pressure, and, therefore, allows correction of global longitudinal strain for changing afterload conditions. We sought to investigate MW as a tool to detect early signs of LV dysfunction in primary systemic hypertension patients, particularly with different predictive indices.None left ventricular hypertrophy (NLVH) and left ventricular hypertrophy (LVH) patients established were all primary systemic hypertension with preserved ejection fraction. Forty in NLVH and forty in LVH according to left ventricular end-diastolic mass index (LVEDmassI) were prospectively enrolled. The following indices of MW were assessed: global work index, global constructive work, global wasted work (GWW), and global work efficiency (GWE). Both global work index (P=0.348) and global constructive work (P=0.225) were increased in NLVH and decreased in LVH, and GWW (P0.001) was increased significantly in NLVH and increased more in LVH, while GWE (P0.001) was decreased significantly in NLVH and decreased more in LVH. The clinical utility of GWW (95% CI: 0.802-0.951) and GWE (95% CI: 0.811-0.950) were verified by receiver-operating characteristic curve analysis showing larger net benefits as evaluated with LVH and control comparisons. In multivariate linear regression analysis, 4-dimenaional LVEDmassI was independently associated with GWE (P=0.018) in systemic hypertension patients. Assessment of intraobserver and interobserver variability in the MW echocardiographic data documented good interclass correlation coefficients (all0.85).GWW and GWE derived from MW are more accurate, sensitive, and reproducible predictors to detect early LV dysfunction in primary systemic hypertension patients, especially in distinguishing the potential functional abnormality of NLVH and LVH, even though the ejection fraction is preserved.
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- 2022
8. Easily missed diagnosis of testicular choriocarcinoma with a large retroperitoneal mass as the primary symptom: a case report
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Bin Zhong, Tao Zhang, Yi Dong, Wei Yin, Jian-Xin Zhang, and Wei-Dong Jin
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Testicular choriocarcinoma is a relatively rare malignancy with a highly aggressive nature. Timely diagnosis and treatment can help prolong the survival of patients and even cure them. This case reports a 29-year-old male who presented to the clinic for a month with epigastric pain without complaints of discomfort in the reproductive system. On examination, only a massive mass of approximately 9*10 cm could be palpated in the upper abdomen. When asked about his previous history, the patient only described a history of a right inguinal hernia that had been repaired 12 years earlier without knowing that a testicular descending fixation had been performed at the same time (we only found out afterward by asking his parents). The admission diagnosis was considered the retroperitoneal tumor, which was found to have metastasized to the liver and lungs after the completion of relevant tests. We then performed a CT-guided puncture biopsy of the lung tissue. The biopsy pathology suggested only a tiny heterotypic cell mass, and metastatic cancer was considered. As the symptoms of tumor compression gradually worsened, we nevertheless performed surgical treatment (retroperitoneal tumor resection + partial duodenal resection + enteroanastomosis). The postoperative pathology was choriocarcinoma. It was at this point that we pursued the patient's medical history in detail and, at the same time, performed a testicular ultrasound which revealed a substantial occupation of the right testicle. The diagnosis of testicular choriocarcinoma was finally considered (without pathological confirmation). We wanted to start salvage chemotherapy as soon as possible after surgery. However, the patient's postoperative condition was poor, with rapid progression of hepatopulmonary metastases and gradually increased thyrotoxicosis, and we started salvage chemotherapy (EP regimen: etoposide and cisplatin) on postoperative day 12. However, the patient was forced to stop due to a severe chemotherapy reaction and eventually died of respiratory and cardiac arrest in hospital. For men presenting with a large retroperitoneal mass without reproductive system-related complaints, a detailed history of the inguinal testicle should still be inquired with a detailed physical examination. Meanwhile, laboratory and image tests should be performed to rule out the possibility of a genital tumor to avoid a missed diagnosis that could lead to delayed treatment.
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- 2022
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9. FAM3 family genes are associated with prognostic value of human cancer: a pan-cancer analysis
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Qing-Tai Dong, Dan-Dan Ma, Qi Gong, Zhen-Yu Lin, Zhong-Hu Li, Jia-Xin Ye, Chun-Hui Qin, Wei-Dong Jin, Jian-Xin Zhang, and Zhi-Yong Zhang
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Background: Family with sequence similarity three member (FAM3) plays a crucial role in the malignant development of various cancers of human. Our study aimed to investigate the role of FAM3 family genes in prognosis, immune subtype, tumor immune microenvironment, stemness score, and anticancer drug sensitivity of pan-cancer. Methods: The expression, survival, immune subtype, tumor microenvironment, stemness score, and anticancer drug sensitivity analysis data of FAM3 family genes associated with pan-cancer from UCSC Xena GDC and CellMiner databases. Furthermore, we investigated the tumor cellular functions and clinical prognostic value FAMC3 in pancreatic cancer (PAAD) using cellular experiments and tissue microarray. Results: The results revealed that FAM3 family genes are significantly differential expression in tumor and adjacent normal tissues in 7 cancers (CHOL, HNSC, KICH, LUAD, LUSC, READ, and STAD). The expression of FAM3 family genes were negatively related with the RNAss, and robust correlated with immune type, tumor immune microenvironment and drug sensitivity. Meanwhile, overexpression FAM3C promoted PAAD cell proliferation, migration, invasion and suppressed PAAD cell apoptosis. While knockdown of FAM3C triggered opposite results. High FAM3C expression was associated with duodenal invasion, differentiation and liver metastasis. Conclusion: This study provided a new perspective on the potential therapeutic role of FAM3 family genes in pan-cancer. In particular, FAM3C may be a new marker for PAAD, providing a new idea for the treatment of PAAD.
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- 2022
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10. Cu-Catalyzed Remote Transarylation of Amines via Unstrained C–C Functionalization
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Wei Shu, Jian-Xin Zhang, and Yu Wang
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chemistry ,010405 organic chemistry ,Polymer chemistry ,chemistry.chemical_element ,Surface modification ,General Chemistry ,010402 general chemistry ,Cleavage (embryo) ,01 natural sciences ,Copper ,Catalysis ,0104 chemical sciences - Abstract
Remote arylation of amines via C–C bond functionalization has not been reported yet. Herein, we develop the γ-transarylation of amines through the cleavage of unstrained C–C bond enabled by copper ...
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- 2020
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11. circVMA21 combining with TAF15 stabilizes SOCS3 mRNA to relieve septic lung injury through regulating NF-κB activation
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Zi-Gui Zhu, Gu-Qing Liao, Jian-Xin Zhang, Cheng-Jian He, and Zhi-Chao Ni
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Lipopolysaccharides ,TATA-Binding Protein Associated Factors ,Superoxide Dismutase ,Immunology ,Acute Lung Injury ,NF-kappa B ,Apoptosis ,Suppressor of Cytokine Signaling Proteins ,Suppressor of Cytokine Signaling 3 Protein ,Sepsis ,Cytokines ,Humans ,RNA, Messenger ,Reactive Oxygen Species ,Molecular Biology ,Signal Transduction - Abstract
Lung injury is a severe complication of sepsis, which brings great threats and challenges to human health. CircVMA21 has exhibited powerful anti- inflammation capacity. However, its underlying molecule mechanism remains blurry.Lipopolysaccharide (LPS) was used to treat mice and WI-38 cells to establish models of lung injury caused by sepsis. Lung injury was evaluated using HE staining. Cell apoptosis was tested by TUNEL and flow cytometry. Levels of inflammatory cytokines were detected using ELISA assay. CircVMA21 and SOCS3 expression was measured using RT-qPCR. The ROS, MDA, SOD and GSH production were monitored by commercial kits. The protein expression was examined with western blot. The correlations among circVMA21, SOCS3 and TAF15 were confirmed using RIP and RNA-pull down.The expression of circVMA21 and SOCS3 was downregulated in LPS-induced lung injury of mice and WI-38 cells. Overexpressing circVMA21 or SOCS3 assuaged LPS-induced cell injury through repressing the levels of inflammatory factors, oxidative stress and cell apoptosis. NF-κB signaling pathway was inactivated by circVMA21 or SOCS3 overexpression. circVMA21 enhanced the stabilization of SOCS3 mRNA via interplaying with TAF15. SOCS3 knockdown destroyed the beneficial impacts of circVMA21 overexpression on LPS-induced cell injury.CircVMA21 suppressed LPS-induced the levels of inflammatory factors, oxidative stress and cell apoptosis and improved LPS-induced lung injury by mediating TAF15/SOCS3/NF-κB axis.
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- 2022
12. [Clinical study on modified Topping-off technology in the treatment of multiple lumbar degenerative diseases]
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Peng, Kong, Hong-Dong, Tan, Jian-Xin, Zhang, Chang-Jiao, Ji, and Liang, Xu
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Adult ,Aged, 80 and over ,Male ,Technology ,Lumbar Vertebrae ,Spinal Fusion ,Bone Screws ,Lumbosacral Region ,Humans ,Female ,Middle Aged ,Aged - Abstract
To explore the clinical effect of the modified Topping-off technique in the treatment of multiple lumbar degenerative diseases.From October 2019 to May 2020, 42 patients who underwent modified Topping-off operation (modified Topping-off group) and 42 patients who underwent multilevel total laminectomy and interbody fusion with screw rod system internal fixation (whole laminectomy group) were observed and analyzed. There were 15 males and 27 females in the modified Topping-off group, aged from 28 to 80 years old, with an average of (59.57±11.85)years old. There were 14 males and 28 females in the whole laminectomy group, aged from 45 to 82 years old, with an average of (64.26±9.19) years old. Visual analogue scale (VAS) and Oswestry Disability Index (ODI) were evaluated before operation, 1 week, 6 weeks and 12 weeks after operation. The intraoperative blood loss, incision length, operation time, postoperative drainage, weight-bearing time, hospitalization time, intervertebral space height, intervertebral foramen height and lumbar mobility were statistically analyzed.All patients were followed up for 12 weeks. The intraoperative blood loss and postoperative drainage in the modified Topping-off group were significantly less than those in the whole lamina group (The application of modified Topping-off technique in the treatment of multi segmental lumbar degenerative diseases can reduce the total length of fusion segments, avoid or slow down the degeneration of adjacent segments, and has a positive effect on maintaining the normal movement of the spine.
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- 2022
13. Clinical Efficacy of Tuomin Zhiti Decoction in Allergic Rhinitis
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Jian-Xin Zhang and Wen-Yan Wang
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Complementary and alternative medicine - Abstract
Allergic rhinitis (AR) is a noninfectious inflammatory disease seriously affecting the quality of life. This study aimed to assess the efficacy of the Tuomin Zhiti decoction in allergic rhinitis and to provide a reference for clinical treatment. One hundred patients with AR treated in the Department of Otolaryngology of our hospital from January 2019 to December 2020 were recruited and assigned via a random number table method (1 : 1) to receive either oral loratadine and mometasone nasal spray (control group) or the Tuomin Zhiti decoction plus oral loratadine and mometasone nasal spray (study group). The total clinical efficacy was 86% (43/50) in the study group, which was significantly higher than that of 64% (32/50) in the control group. After treatment, the Total Nasal Symptoms Scores (TNSS) and Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ) scores between the two groups were similar, but 12 weeks after treatment, the study group had significantly lower TNSS and RQLQ scores than the control group. After treatment, the study group obtained lower levels of interleukin (IL)-4 and higher levels of interferon-γ (IFN-γ) than the control group. Significantly lower post-treatment peripheral blood eosinophil count (EOS) and eosinophil cationic protein (ECP) levels were observed in the study group in contrast to those of the control group. The Tuomin Zhiti decoction for the treatment of AR patients alleviates their clinical symptoms, reduces the inflammatory responses, enhances the immune function of patients by regulating IL-4 and IFN-γ, and lowers the long-term recurrence rate.
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- 2022
14. A preoperative prediction model based on Lymphocyte-C-reactive protein ratio predicts postoperative anastomotic leakage in patients with colorectal carcinoma: a retrospective study
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Bin Zhong, Zhen-Yu Lin, Dan-Dan Ma, Zuo-Hong Shang, Yan-Bin Shen, Tao Zhang, Jian-Xin Zhang, and Wei-Dong Jin
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C-Reactive Protein ,Humans ,Surgery ,Anastomotic Leak ,General Medicine ,Lymphocytes ,Colorectal Neoplasms ,Retrospective Studies - Abstract
Background & Aims Lymphocyte-C-reactive Protein Ratio (LCR) has been demonstrated as a promising new marker for predicting surgical and oncological outcomes in colorectal carcinoma (CRC). However, anastomotic leakage (AL) is also likely related to this inflammatory marker. Herein, we aimed to identify preoperative predictors of AL and build and develop a novel model able to identify patients at risk of developing AL. Methods We collected 858 patients with CRC undergoing elective radical operation between 2007 and 2018 at a single center were retrospectively reviewed. We performed univariable and multivariable analyses and built a multivariable model that predicts AL based on preoperative factors. Propensity adjustment was used to correct the bias introduced by non-random matching of the LCR. The model's performance was evaluated by using the area under the receiver operator characteristic curves (AUROCs), decision curve analysis (DCA), Brier scores, D statistics, and R2 values. Results Age, nutrition risk screening 2002 (NRS2002) score, tumor location and LCR, together with hemoglobin Conclusion Preoperative LCR is an independent predictive factor for AL. A novel model combining LCR values, age, tumor location, and NRS2002 provided an excellent preoperative prediction of AL in patients with CRC. The nomogram can help clinical decision-making and support future research.
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- 2022
15. Channel sandstone Reservoir Prediction Technology and Its Application: A Case Study of Jurassic Shaximiao Formation in Western Sichuan
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Wei-wei He, Xu Guan, Yu-feng Xiao, Xiao-long Guo, and Jian-xin Zhang
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- 2022
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16. Ceftazidime-Avibactam in Combination with In Vitro Non-susceptible Antimicrobials Versus Ceftazidime-Avibactam in Monotherapy in Critically Ill Patients with Carbapenem-Resistant Klebsiella Pneumoniae Infection: A Retrospective Cohort Study
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Bei Wang, Jiaqi Cai, Juan He, Li-li Wang, Zhi-Tao Yang, Liang Zhang, Jian-xin Zhang, Kai-xuan Hou, Xiaolan Bian, Yan Zhang, and Guanhao Zheng
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Microbiology (medical) ,medicine.medical_specialty ,Combination therapy ,biology ,Ceftazidime-avibactam ,business.industry ,Klebsiella pneumoniae ,Hazard ratio ,Retrospective cohort study ,Tigecycline ,Fosfomycin ,Ceftazidime/avibactam ,biology.organism_classification ,Infectious Diseases ,Critically ill patients ,Carbapenem-resistant Klebsiella pneumoniae ,Internal medicine ,Intensive care ,medicine ,Mortality ,business ,Original Research ,medicine.drug - Abstract
Background No clinical study has investigated the use of ceftazidime-avibactam combination schemes with an in vitro non-susceptible antimicrobial that could be superior to ceftazidime-avibactam monotherapy against carbapenem-resistant Klebsiella pneumoniae. Methods We performed a retrospective cohort study at two tertiary hospitals in China for patients with carbapenem-resistant Klebsiella pneumoniae infection treated with ceftazidime-avibactam for at least 72 h. A Cox proportional hazards regression model was used to evaluate covariates that potentially affected 30-day mortality. Results Sixty-two patients were eligible for our study; 41 (66.1%) received ceftazidime-avibactam combination therapy and 21 (33.9%) received ceftazidime-avibactam monotherapy. The overall 30-day mortality was 33.9% (21 patients): 24.4% (10/41) and 47.6% (11/21), P = 0.028, in combination and monotherapy groups, respectively. Combination therapy was significantly associated with lower 30-day mortality (Hazard ratio, 0.167; 95% Confidence Interval, 0.060–0.465, P = 0.001). At the same time, a higher APACHE II score, use of vasoactive drugs and comorbidity of organ transplantation were considered factors that increased mortality. The propensity score showed no significant alterations with other variables after adding it to the final model. In the subgroup analysis, the protective effect was revealed when combined with carbapenems, tigecycline or fosfomycin were applied, and in the following subgroups of patients: with sepsis, with creatinine clearance > 50 mL/min, stayed in the intensive care unit ≤ 30 days or underwent mechanical ventilation. Conclusions Ceftazidime-avibactam combined with another in vitro non-susceptible antimicrobial, especially carbapenems, fosfomycin and tigecycline, could significantly decrease the 30-day mortality rate for critically ill patients with carbapenem-resistant Klebsiella pneumoniae infection. Further investigation should be carried out to confirm this conclusion and identify autofit antimicrobials in ceftazidime-avibactam combination schemes.
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- 2021
17. Ceftazidime-avibactam in combination with in vitro non-susceptible antimicrobials versus ceftazidime-avibactam in monotherapy in critically ill patients with carbapenem-resistant Klebsiella pneumoniae infection
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Yan Zhang, Jiaqi Cai, Jian-xin Zhang, Kai-xuan Hou, Zhi-Tao Yang, Liang Zhang, Bei Wang, Xiao-lan Bian, Li-li Wang, Guan-hao Zheng, and Juan He
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Carbapenem resistant Klebsiella pneumoniae ,business.industry ,Critically ill ,medicine ,Ceftazidime/avibactam ,business ,Antimicrobial ,In vitro ,medicine.drug ,Microbiology - Abstract
Background: There is no clinical study investigating if using CAZ-AVI combination schemes with an in vitro non-susceptible antimicrobial could be superior to CAZ-AVI monotherapy against CRKP clinically. Methods: We performed a retrospective, cohort study at two tertiary hospitals in China for patients with CRKP infection who treated by CAZ-AVI at least 72 hours. A Cox-proportional hazards regression model was set up to evaluate covariates which potentially affected 30-day mortality. Results: Sixty-two patients were eligible in our study, 41 (66.1%) received CZA-AVI combination therapy and 21 (33.9%) received CZA-AVI monotherapy. The overall 30-day mortality was 33.9% (21 patients): 24.4% (10/41) and 47.6% (11/21), P=0.028, in combination and monotherapy groups, respectively. Combination therapy was significantly associated with lower 30-day mortality (HR 0.167, 95%CI 0.060-0.465, P=0.001), while higher APACHE II score, use of vasoactive drug and comorbidity of organ transplantation were considered as factors on increasing mortality. The propensity score showed no significant alteration with other variables after adding it into the final model. In the subgroup analysis, the protective effect revealed when combination with carbapenems, tigecycline or fosfomycin were applied, and in the following subgroups of patients: with sepsis, with CrCl > 50 mL/min, stayed in ICU ≤30 days or underwent mechanical ventilation. Conclusions: CAZ-AVI combination with another in vitro non-susceptible antimicrobial, especially carbapenems, fosfomycin and tigecycline, could significantly decrease 30-day mortality rate for critically ill patients with CRKP infection. Further investigation should be carried out to confirm this conclusion and find out the autofit antimicrobials in CAZ-AVI combination schemes.
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- 2021
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18. Enantioselective Construction of Trialkyl Tertiary Centers via Ni-Catalyzed Markovnikov Hydrocarbofunctionalizations of Unactivated Olefins and Electrophiles
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Xian-Wang Zeng, Jian-Xin Zhang, Han-Tong Zhao, Jian-Xin Liang, Peng-Fei Yang, and Wei Shu
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Routes to efficient construction of fully aliphatic substituted tertiary chiral centers are highly challenging and desirable. Herein, a Ni-catalyzed enantioselective hydroalkylation of unactivated alkenes at room temperature is described, providing a general and practical access to tertiary stereogenic carbon centers with three alkyl substituents. This reaction involves the regio- and stereoselective hydrometalation of unactivated alkenes with Markovnikov selectivity, followed by coupling with unactivated alkyl electrophiles to access tertiary chiral centers with full alkyl substituents. The mild and robust conditions enable the use of terminal and internal unactivated alkenes as well as primary and secondary unactivated alkyl, benzyl, propargyl halides for the construction of diverse trialkyl tertiary stereogenic carbon centers with broad functional group tolerance.
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- 2021
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19. Enantioselective Access to Dialkyl Amines and Alcohols via Ni-Catalyzed Reductive Hydroalkylations
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Bi-Hong Chen, Huan Meng, Jian-Xin Zhang, Tian-Yi Zhang, and Shan Wang
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Chiral dialkyl amines and alcohols are ubiquitous in pharmaceuticals, pesticides, natural products and fine chemicals, yet difficult to access due to the challenge to differentiate between the spatially and electronically similar alkyl groups. Herein, we report a nickel-catalyzed enantioselective reductive hydroalkylation of enamides and enolates with alkyl halides to afford enantioenriched α-branched aliphatic amines and alcohols in good yields with excellent levels of enantioselectivity. The operationally simple protocol provides a straightforward access to chiral dialkyl amine and alcohol derivatives from simple starting materials with great functional group tolerance.
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- 2021
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20. Enantioselective Access to Dialkyl Amines and Alcohols via Ni-Catalyzed Reductive Hydroalkylations
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Wei Shu, Tian-Yi Zhang, Shan Wang, Bi-Hong Chen, Jian-Xin Zhang, and Huan Meng
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chemistry.chemical_classification ,chemistry.chemical_compound ,Chemistry ,Functional group ,Enantioselective synthesis ,Organic chemistry ,Alcohol ,Amine gas treating ,Alkyl ,Catalysis - Abstract
Chiral dialkyl amines and alcohols are ubiquitous in pharmaceuticals, pesticides, natural products and fine chemicals, yet difficult to access due to the challenge to differentiate between the spatially and electronically similar alkyl groups. Herein, we report a nickel-catalyzed enantioselective reductive hydroalkylation of acyl enamines and enol esters with alkyl halides to afford enantioenriched α-branched aliphatic amines and alcohols in good yields with excellent levels of enantioselectivity. The operationally simple protocol provides a straightforward access to chiral dialkyl amine and alcohol derivatives from simple starting materials with great functional group tolerance.
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- 2021
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21. Method for Measuring the Intensity of Ultrasonic Radiation in Solid Medium
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Li Dezhi, Sheng-Jie Yin, Jian-Xin Zhang, Chunguang Xu, and Yu-Ren Lu
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Materials science ,Field (physics) ,Acoustics ,Measure (physics) ,Inverse ,Ultrasonic sensor ,Sound pressure ,Sound intensity ,Intensity (heat transfer) ,Power (physics) - Abstract
A method based on stratified measurement and inverse fitting is proposed to measure and analyze the intensity of power in solid medium aiming at the problem of power ultrasonic intensity measurement in solid. The thickness of the typical solid medium is determined according to the sound pressure distribution on the acoustic axis of the simulated sound field, and the surface acoustic field is measured separately to obtain the change of the sound intensity in the radial direction. Then the measurements of different thicknesses are fitted based on a fractional linear fit algorithm. Finally, the distribution of the power ultrasonic field in the solid is obtained by using the fitting equation. This paper also compares the experimental measurement results with the COMSOL simulation results. The two have a high degree of similarity in the trend of change, indicating that the measurement scheme is feasible.
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- 2020
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22. Curcumin Synergizes with Cisplatin to Inhibit Colon Cancer through Targeting the MicroRNA-137-Glutaminase Axis
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Wen-hui Fan, Feng-chun Wang, Zhi Jin, Lin Zhu, and Jian-xin Zhang
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MicroRNAs ,Curcumin ,Glutaminase ,Cell Line, Tumor ,Genetics ,Humans ,Antineoplastic Agents ,Cisplatin ,Colorectal Neoplasms ,Biochemistry - Abstract
Colorectal cancer (CRC) is one of the most lethal and prevalent malignancies world-wide. Currently, surgery, radiotherapy and chemotherapy are clinically applied as common approaches for CRC patients. Cisplatin is one of the most frequently used chemotherapy drugs for diverse cancers. Although chemotherapeutic strategies have improved the prognosis and survival of cancer patients, development of cisplatin resistance has led to cancer recurrence. Curcumin, isolated from turmeric, has been used as an effective anti-cancer agent. However, the molecular mechanisms for curcumin-mediated cisplatin sensitivity of CRC have not been elucidated. This study aimed to investigate the effects of curcumin treatment on cisplatin-resistant CRC cells.Expression levels of miRNAs and mRNAs were determined by qRT-PCR. Protein expression levels were detected by Western blotting. Cell responses to curcumin treatments were evaluated by MTT assay, Clonogenic assay and Annexin V apoptosis assay. The glutamine metabolism of colon cancer cells was assessed by glutamine uptake and glutaminase (GLS) activity. The binding of miR-137 on 3' UTR of GLS was validated by Western blotting and luciferase assay.Results demonstrated that curcumin significantly synergized with cisplatin (combination index1) to suppress proliferation of colon cancer cells compared with curcumin or cisplatin alone. Moreover, from the established cisplatin-resistant cell line (HT-29), glutamine metabolism was remarkedly elevated in cisplatin-resistant CRC cells that displayed a glutamine addictive phenotype. Furthermore, curcumin treatments attenuated glutamine metabolism in colon cancer cells. Under low glutamine supply, colon cancer cells showed less sensitivity to curcumin. Using a microRNA (miRNA) microArray assay, miR-137, a tumor suppressor in colon cancer, was significantly induced by curcumin treatments in CRC cells. Bioinformatics analysis and a luciferase assay illustrated miR-137 directly targeted the 3' UTR of GLS mRNA. Rescue experiments demonstrated that miR-137-induced cisplatin sensitization was through targeting of GLS. Finally, curcumin treatment overcame cisplatin resistance through miR-137-mediated glutamine inhibition.Collectively, these results indicate that curcumin could be clinically applied as an anti-chemoresistance approach against CRC by modulating miR-137-inhibited glutamine metabolism.
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- 2020
23. Magnetic resonance imaging tumor response score (mrTRS) predicts therapeutic effect and prognosis of locally advanced rectal cancer after neoadjuvant chemoradiotherapy: A prospective, multi-center study
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Xiao-Ping Yu, Xin-Ming Zhao, Lu Wen, Rui-Jia Sun, Wuteng Cao, Hong-Mei Zhang, Xiao-Ting Li, Zhen Guan, Jian-Xin Zhang, Tao Yu, Ying-Shi Sun, Zhi-Yang Zhou, and Xiaoyan Zhang
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medicine.medical_specialty ,Colorectal cancer ,Lower risk ,030218 nuclear medicine & medical imaging ,03 medical and health sciences ,0302 clinical medicine ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Prospective Studies ,Pathological ,Retrospective Studies ,Tumor Regression Grade ,Receiver operating characteristic ,medicine.diagnostic_test ,Proportional hazards model ,business.industry ,Rectal Neoplasms ,Therapeutic effect ,Magnetic resonance imaging ,Hematology ,Chemoradiotherapy ,medicine.disease ,Prognosis ,Magnetic Resonance Imaging ,Neoadjuvant Therapy ,Treatment Outcome ,Oncology ,030220 oncology & carcinogenesis ,Radiology ,Neoplasm Recurrence, Local ,business - Abstract
Background and purpose The MRI-assessed tumor regression grade (mrTRG) is limited due to its subjectivity and poor consistency on pathological tumor regression grade (pTRG). A new MRI criterion was established to predict the prognosis of locally advanced rectal cancer (LARC). Materials and methods The new MRI criterion magnetic resonance imaging tumor response score (mrTRS) was based on the retrospective sample of 214 LARC patients (unpublished data). Subsequently, 878 LARC patients were enrolled for a prospective, multicenter study. Baseline and postoperative MRI were obtained, and imaging features were measured by collecting the pathological, clinical and follow-up data. Kaplan-Meier method with log-rank estimate and multivariate cox regression model was used to determine the prognosis of mrTRS in LARC patients with neoadjuvant chemoradiotherapy (NACRT). The predictive capability of 3-year prognosis between mrTRS and mrTRG was determined by time-dependent ROC curves. Results The results demonstrated that mrTRS acted as an independent predictor of survival outcomes. mrTRS stratified by good and moderate responders showed significantly lower risk of death (HR = 0.04, 95%CI 0.01–0.31; HR = 0.35, 95%CI 0.23–0.52), distant metastasis (HR = 0.25, 95%CI 0.13–0.52; HR = 0.42, 95%CI 0.30–0.58), and local recurrence when compared with poor responders(HR = 0.01 95%CI 0.23–0.52;HR = 0.38, 95%CI 0.16–0.90). In contrast, no significant difference was observed among mrTRG stratified groups. Excellent and substantial interobserver agreement for mrTRS and mrTRG evaluation was observed (κ = 0.92 and 0.62), respectively. Conclusion mrTRS can serve as an effective predictor for assessing tumor regression grade in LARC patients with NACRT.
- Published
- 2020
24. Effect of dietary honeysuckle (Lonicera caerulea L.) supplementation on lipid metabolism, immunity and intestinal microbiota in grass carp (Ctenopharyngodon idellus)
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Xiao-Lin Meng, Hui Cao, Heng Li, Ke-ke Li, Guo-kun Yang, Yan-Ming Zhang, Xu-lu Chang, Xin-dang Zhang, and Jian-xin Zhang
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Animal Science and Zoology ,Aquatic Science - Published
- 2022
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25. pH-Switched fluorescent pseudorotaxane assembly of cucurbit[7]uril with bispyridinium ethylene derivatives
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Xiaowei Cui, Tao Sun, Xin-Long Ni, Jian-Xin Zhang, Wei Wu, and Sen Song
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Ethylene ,Rotaxane ,010405 organic chemistry ,Protonation ,macromolecular substances ,General Chemistry ,010402 general chemistry ,Photochemistry ,01 natural sciences ,Fluorescence ,0104 chemical sciences ,chemistry.chemical_compound ,Deprotonation ,Molecular shuttle ,chemistry ,Polymer chemistry ,Proton NMR ,Moiety - Abstract
The host-guest properties of cucurbit[7]uril (Q[7]) and bispyridinium ethylene derivatives have been studied by 1 H NMR spectroscopy, UV–vis absorption spectra, and fluorescence emission analysis. The proton shifts associated with the guest encapsulated by the host suggested that the Q[7]-based [2] pseudo rotaxane behaves like a fast molecular shuttle along the bispyridinium ethylene axle of the guest upon protonation and deprotonation of the terminal carboxylates. In particular, the distinct fluorescent response signals indicated that the bispyridinium ethylene moiety not only behaves as the axle component for the pseudo rotaxane system, but also acts as an optical reporting unit during the host–guest complexation.
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- 2018
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26. Cytotoxic and anti-oxidant biphenyl derivatives from the leaves and twigs of Garcinia multiflora
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Lie-Jun Huang, Qing Rao, Yan-Hui Fu, Chun-Mao Yuan, Liping Wang, Wei Gu, Tao Huang, Dongsong Tian, Xiao-Jiang Hao, and Jian-Xin Zhang
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biology ,010405 organic chemistry ,Chemistry ,Biphenyl derivatives ,Plant Science ,Nuclear magnetic resonance spectroscopy ,Anti oxidant ,Mass spectrometry ,biology.organism_classification ,01 natural sciences ,Biochemistry ,0104 chemical sciences ,Human tumor ,010404 medicinal & biomolecular chemistry ,Garcinia multiflora ,Organic chemistry ,Cytotoxic T cell ,Cytotoxicity ,Agronomy and Crop Science ,Biotechnology - Abstract
Three new biphenyl derivatives ( 1 – 3 ), together with five known compounds, were isolated from the leaves and twigs of Garcinia multiflora . Their structures were determined by extensive spectroscopic techniques including NMR spectroscopy and mass spectrometry. All eight isolates showed weak cytotoxicity on five human tumor cell lines. In addition, the three biphenyl derivatives showed moderate anti-oxidant activity with IC 50 values ranging from 7.78 to 8.78 μ M.
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- 2017
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27. Dexamethasone-induced diuresis is associated with inhibition of the renin–angiotensin–aldosterone system in rats
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Chao Liu, Jian-Xin Zhang, Jian-Long Zhai, and Ning Ge
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Male ,0301 basic medicine ,medicine.medical_specialty ,Time Factors ,medicine.medical_treatment ,Diuresis ,Heart failure ,030204 cardiovascular system & hematology ,Dexamethasone ,Rats, Sprague-Dawley ,Renin-Angiotensin System ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Glucocorticoid receptor ,Internal medicine ,Renin–angiotensin system ,Animals ,Medicine ,Aldosterone ,Medicine(all) ,lcsh:R5-920 ,Dehydration ,business.industry ,Angiotensin II ,General Medicine ,medicine.disease ,Disease Models, Animal ,Mifepristone ,030104 developmental biology ,Endocrinology ,chemistry ,Chronic Disease ,Diuretic ,lcsh:Medicine (General) ,business ,hormones, hormone substitutes, and hormone antagonists ,medicine.drug - Abstract
In heart failure (HF) patients, diuretics remain the cornerstone of therapy to relieve fluid retention. However, the resulting volume loss activates the renin-angiotensin-aldosterone system (RAAS), which blunts the decline in volume depletion and blood pressure. RAAS activation, in turn, compromises the diuretic decongesting effect. Although corticosteroids can induce potent diuresis in HF patients, the effects of corticosteroids on RAAS activation remain unclear. Therefore, we assessed the effects of dexamethasone (Dex) on urine output and plasma angiotensin II and aldosterone levels in rats following water deprivation-induced dehydration, following induction of chronic HF (CHF), and following induction of CHF and volume expansion therapy. In the dehydration model, Dex significantly increased urine output and inhibited dehydration-induced RAAS activation. This favorable effect was abolished by the glucocorticoid receptor antagonist RU486, suggesting involvement of the glucocorticoid receptor. In the CHF model, Dex treatments doubled urine output without activating RAAS. Moreover, in acute volume expansion experiments, Dex pretreatments led to potent diuresis during the pretreatment period and restored renal adaptation to acute volume expansion without activating RAAS in rats with CHF. Collectively, these data show that corticosteroids induce potent diuresis without activating RAAS in rats.
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- 2016
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28. Cardiac magnetic resonance and galectin-3 level as predictors of prognostic outcomes for non-ischemic cardiomyopathy patients
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Ya-Nan Zhou, Min Zhong, Da-Jun Hu, Wei Du, Jing Xu, and Jian-Xin Zhang
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Male ,Multivariate analysis ,Galectin 3 ,Cardiomyopathy ,Contrast Media ,Kaplan-Meier Estimate ,030204 cardiovascular system & hematology ,Ventricular Function, Left ,0302 clinical medicine ,Prospective Studies ,030212 general & internal medicine ,Ventricular Remodeling ,Hazard ratio ,Hypertrophic cardiomyopathy ,Dilated cardiomyopathy ,Blood Proteins ,Middle Aged ,Prognosis ,Magnetic Resonance Imaging ,Up-Regulation ,Galectin-3 ,Area Under Curve ,embryonic structures ,cardiovascular system ,Cardiology ,Female ,Cardiology and Cardiovascular Medicine ,Adult ,Cardiomyopathy, Dilated ,medicine.medical_specialty ,Galectins ,03 medical and health sciences ,Predictive Value of Tests ,Internal medicine ,medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,cardiovascular diseases ,Survival analysis ,Aged ,Proportional Hazards Models ,Chi-Square Distribution ,Proportional hazards model ,business.industry ,Reproducibility of Results ,Stroke Volume ,Cardiomyopathy, Hypertrophic ,medicine.disease ,ROC Curve ,Multivariate Analysis ,business ,Biomarkers - Abstract
This study was aimed at determining whether late gadolinium enhancement (LGE) in conjunction with Galectin-3 (Gal-3) level offered more precise prognosis of non-ischemic cardiomyopathy (NICM) in comparison to LGE alone. Results of LGE and Gal-3 expression in 192 patients with NICM, including 85 subjects with dilated cardiomyopathy (DCM) and 107 with hypertrophic cardiomyopathy (HCM), were examined. As suggested by the characteristics of LGE and Gal-3 levels, patients were divided into four groups: LGE positive + low Gal-3 (n = 10 for DCM, n = 15 for HCM), LGE positive + high Gal-3 (n = 25 for DCM, n = 51 for HCM), LGE negative + low Gal-3 (n = 32 for DCM, n = 29 for HCM), LGE negative + high Gal-3 (n = 18 for DCM, n = 12 for HCM). Primary endpoints over the follow-up period included major adverse cardiac events (MACEs). Kaplan–Meier survival analysis and univariate Cox proportional hazard models were used to analyze the survival status of patients with NICM. The optimal cut-off value of Gal-3 level for two types of NICM was determined by receiver operating characteristic analysis (13.38 U/L for DCM and 14.40 U/L for HCM). The combination of LGE and Gal-3 levels offered a more significant prognostic value than using LGE alone for both DCM and HCM (DCM P = 0.001
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- 2016
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29. One-pot synthesis of close-packed titanium dioxides on graphene oxides
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Jia Hui Peng, Jian Xin Zhang, Hao Chen, and Xiaoying Liu
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Anatase ,Materials science ,Chemical substance ,One-pot synthesis ,chemistry.chemical_element ,Nanotechnology ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,law.invention ,chemistry.chemical_compound ,law ,Materials Chemistry ,Graphene ,Process Chemistry and Technology ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,chemistry ,Nanocrystal ,Titanium dioxide ,Ceramics and Composites ,0210 nano-technology ,Science, technology and society ,Titanium - Abstract
In this work, we have developed a one-pot chemical approach to fabricate crystalline anatase TiO2 onto graphene oxides with controlled TiO2 distribution. Possible formation mechanism of such architecture is addressed. Interestingly, TiO2 nanocrystals can be anchored within detached GOs, which could provide high surface area and close connection between both components to promote ions penetration and electron transport in promising energy conversion and storage applications.
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- 2016
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30. Assessment of Left Ventricular Myocardial Viability by 3-Dimensional Speckle-Tracking Echocardiography in Patients With Myocardial Infarction
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You-Xiang Zhang, Jian-Xin Zhang, Jing Dong, Hong Ran, Ping-Yang Zhang, Wenfang Wu, and Xiao-Wu Ma
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Male ,medicine.medical_specialty ,Heart Ventricles ,Echocardiography, Three-Dimensional ,Myocardial Infarction ,Speckle tracking echocardiography ,030204 cardiovascular system & hematology ,Sensitivity and Specificity ,030218 nuclear medicine & medical imaging ,Ventricular Dysfunction, Left ,03 medical and health sciences ,0302 clinical medicine ,Internal medicine ,Image Interpretation, Computer-Assisted ,medicine ,Humans ,Cutoff ,Radiology, Nuclear Medicine and imaging ,In patient ,Myocardial infarction ,Radiological and Ultrasound Technology ,medicine.diagnostic_test ,business.industry ,Reproducibility of Results ,Middle Aged ,medicine.disease ,ROC Curve ,Positron emission tomography ,Cardiology ,Female ,Nuclear medicine ,business ,Radial stress ,Perfusion ,Emission computed tomography - Abstract
Objectives To determine whether 3-dimensional (3D) speckle-tracking echocardiography could provide a new way to assess myocardial viability in patients with myocardial infarction (MI). Methods Forty-five patients with MI underwent routine echocardiography, 2-dimensional (2D) speckle-tracking echocardiography, and 3D speckle-tracking echocardiography. Radionuclide myocardial perfusion/metabolic imaging was used as a reference standard to define viable and nonviable myocardia. Results Among 720 myocardial segments in 45 patients, 368 showed abnormal motion on routine echocardiography; 204 of 368 were categorized as viable on single-photon emission computed tomography/positron emission tomography (SPECT/PET), whereas 164 were defined as nonviable; 300 normal segments on SPECT/PET among 352 segments without abnormal motion on routine echocardiography were categorized as a control group. The radial, longitudinal, 3D, and area strain on 3D speckle-tracking echocardiography had significant differences between control and nonviable groups (P < .001), whereas none of the parameters had significant differences between control and viable groups. There were no significant differences in circumferential, radial, and longitudinal peak systolic strain from 2D speckle-tracking echocardiography between viable and nonviable groups. Although there was no significant difference in circumferential strain between the groups, radial and longitudinal strain from 3D speckle-tracking echocardiography decreased significantly in the nonviable group. Moreover, 3D and area strain values were lower in the nonviable segments than the viable segments. By receiver operating characteristic analysis, radial strain from 3D speckle-tracking echocardiography with a cutoff of 11.1% had sensitivity of 95.1% and specificity of 53.4% for viable segments; longitudinal strain with a cutoff of 14.3% had sensitivity of 65.2% and specificity of 65.7%; 3D strain with a cutoff of 17.4% had sensitivity of 70.6% and specificity of 77.2%; and area strain with a cutoff of 23.2% had sensitivity of 91.5% and specificity of 82.8%. Conclusions Three-dimensional speckle-tracking echocardiography might have potential for detection of myocardial viability in patients with cardiac dysfunction due to MI.
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- 2016
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31. Synthesis and evaluation of antifungal activity of C21-steroidal derivatives
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Bin Wang, Shu-Zhen Mu, Chun-Mao Yuan, Xiao-Jiang Hao, Wei Gu, Jian-Xin Zhang, and Lie-Jun Huang
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Antifungal ,Antifungal Agents ,Stereochemistry ,medicine.drug_class ,Clinical Biochemistry ,Molecular Conformation ,Pharmaceutical Science ,Microbial Sensitivity Tests ,Cynanchum ,010402 general chemistry ,01 natural sciences ,Biochemistry ,Structure-Activity Relationship ,Ascomycota ,Drug Discovery ,Ic50 values ,medicine ,Structure–activity relationship ,Molecular Biology ,Mycelium ,Dose-Response Relationship, Drug ,biology ,010405 organic chemistry ,Chemistry ,Organic Chemistry ,Sclerotinia sclerotiorum ,biology.organism_classification ,0104 chemical sciences ,Cynanchum wilfordii ,Molecular Medicine ,Steroids - Abstract
The antifungal activities of eleven C21-steroidal compounds isolated from Cynanchum wilfordii, together with thirty-six derivatives of caudatin and qingyangshengenin were evaluated on Sclerotinia sclerotiorum and other five fungal strains by the mycelium growth rate method. Four derivatives 1k, 1y, 10d, and 10j exhibited much stronger inhibitions on growth of S. sclerotiorum with IC50 values of 0.0084, 0.0049, 0.0053, and 0.0034 μM, respectively.
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- 2016
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32. 18β-Glycyrrhetinic Acid Derivatives Possessing a Trihydroxylated A Ring Are Potent Gram-Positive Antibacterial Agents
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Dao-Ping Wang, Qi-Ji Li, Xiao-Sheng Yang, Heng Luo, Li-Rong Huang, Xiao-Jiang Hao, and Jian-Xin Zhang
- Subjects
Methicillin-Resistant Staphylococcus aureus ,0301 basic medicine ,Pharmaceutical Science ,Virulence ,Microbial Sensitivity Tests ,Bacillus subtilis ,Gram-Positive Bacteria ,Real-Time Polymerase Chain Reaction ,medicine.disease_cause ,01 natural sciences ,Analytical Chemistry ,Microbiology ,Structure-Activity Relationship ,03 medical and health sciences ,Vancomycin ,Drug Discovery ,Glycyrrhiza ,medicine ,Structure–activity relationship ,Mode of action ,Pharmacology ,Dose-Response Relationship, Drug ,Molecular Structure ,biology ,010405 organic chemistry ,Organic Chemistry ,biology.organism_classification ,Streptomyces ,Anti-Bacterial Agents ,0104 chemical sciences ,030104 developmental biology ,Complementary and alternative medicine ,Biochemistry ,Staphylococcus aureus ,Streptomycin ,Pseudomonas aeruginosa ,Glycyrrhetinic Acid ,Molecular Medicine ,Ampicillin ,Antibacterial activity ,Bacteria ,medicine.drug - Abstract
The oleanane-type triterpene 18β-glycyrrhetinic acid (1) was modified chemically through the introduction of a trihydroxylated A ring and an ester moiety at C-20 to enhance its antibacterial activity. Compounds 22, 23, 25, 28, 29, 31, and 32 showed more potent inhibitory activity against Streptomyces scabies than the positive control, streptomycin. Additionally, the inhibitory activity of the most potent compound, 29, against Bacillus subtilis, Staphylococcus aureus, and methicillin-resistant Staphylococcus aureus was greater than that of the positive controls. The antibacterial mode of action of the active derivatives involved the regulation of the expression of genes associated with peptidoglycans, the respiratory metabolism, and the inherent virulence factors found in bacteria, as determined through a quantitative real-time reverse transcriptase PCR assay.
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- 2016
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33. The paleotectonic and paleogeography reconstructions of the Tarim Basin and its adjacent areas (NW China) during the late Early and Middle Paleozoic
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Zhiqin Xu, Zhihui Cai, Zhuoyin Yu, Shilin Liu, Jian-Xin Zhang, Haibin Li, Cunli Jiao, Bizhu He, and Weiwei Chen
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geography ,geography.geographical_feature_category ,020209 energy ,Geology ,Orogeny ,02 engineering and technology ,Structural basin ,Fault (geology) ,010502 geochemistry & geophysics ,01 natural sciences ,Unconformity ,Devonian ,Tectonics ,Paleontology ,0202 electrical engineering, electronic engineering, information engineering ,Sedimentary rock ,Sequence stratigraphy ,Geomorphology ,0105 earth and related environmental sciences - Abstract
Tarim Basin is the large, very complex, oil-bearing basin in China, surrounded by the Tianshan–Beishan, West Kunlun and Altyn Tagh mountain belts to the north, south, and southeast, respectively. Understanding the processes and evolution of this complex superimposed basin, especially with respect to the effects of single tectonic movements, is a difficult challenge, which concerns the tectonic and dynamic interrelationships between the basin and the orogenic belts during the different stages of the Paleozoic in the Paleo-Asian and Tethyan tectonic systems and for the evaluation of the resource potentials in Tarim Basin. In this study, we focused on 3-dimensional, basin-scale structural architecture and the properties of two regional unconformities that occur within the basin and its adjacent areas. Here, we outline the structural deformations underlying the unconformity, the structural architecture styles and the distributions of the unconformity, and the stratigraphic sequence and nature of the sedimentary rocks immediately overlying the unconformity. During the late Early and Middle Paleozoic tectonic movements, disconformities developed mainly in the northern and the central parts of the basin, and angular unconformities which beneath layers were monocline and faulted-fold deformations developed in the southern, or the southern and northern parts of the basin, respectively. Before the Silurian, the Low Hotian Uplift, the NE-trending faulted-folded belts of the Tangguzibas Depression and the southern Tazhong Uplift underwent intense deformation related to SE–NW-directed tectonic compression. In addition, the NE-trending faults in the Tangguzibas Depression developed during periods of activity on the South Altyn Tagh Fault. The structural deformation, as well as the depositional facies, formed in response to the subduction and closure of the South Altun Ocean and West Kunlun–Kudi Ocean, and the resulting collisional orogeny. Prior to deposition of Upper Devonian sediments, structural deformation and erosion occurred in two marginal parts of the basin. The extent and intensity of deformation on the NE-trending faults in the Tangguzibas Depression were also reduced, whereas the NE-trending folds developed in the Manjiaer Depression. The Tabei Uplift experienced uplift and deformation. The closure of the North Altun Ocean and the eastern part of the South Tianshan Ocean with south-subduction may be the main driving forces for the tectonic activity. Extensive areas in the northern and southern margins of the basin were uplifted and denudated by orogenic activity as a prelude to the molasse basin that developed in the early Late Devonian in the northeastern and southeastern parts of the basin. The structural architecture of the unconformities reveals the geometry and dynamics of the basin–orogen system in single tectonic movements.
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- 2016
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34. Limonoids from Munronia henryi and their anti-tobacco mosaic virus activity
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Xiao-Jiang Hao, Tao Huang, Ying Yan, Jian-Xin Zhang, Ying-Tong Di, Yuan Ma, Chun-Mao Yuan, and Yi-Min Fan
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Limonins ,Pharmacology ,Meliaceae ,Molecular Structure ,Mosaic virus ,biology ,medicine.diagnostic_test ,Plant Extracts ,Stereochemistry ,Phytosterol ,Phytosterols ,General Medicine ,biology.organism_classification ,Antiviral Agents ,Terpenoid ,Tobacco Mosaic Virus ,Structure-Activity Relationship ,Western blot ,Drug Discovery ,medicine ,Tobacco mosaic virus ,Structure–activity relationship ,Diterpenes ,IC50 - Abstract
Five new compounds (1-5), including three limonoids, one diterpenoid, and one phytosterol, along with four known limonoids (6-9), were isolated from the ethanolic extracts of whole plants of Munronia henryi. Their structures were elucidated by extensive spectroscopic analysis. In addition, the anti-tobacco mosaic virus (TMV) activities of all the isolated compounds were evaluated by the conventional half-leaf and leaf-disk methods along with Western blot analysis. Most of the tested compounds showed strong antiviral activities, with IC50 values in the range of 14.8-34.0 mu g/mL, compared with ningnanmycin as a positive control (IC50 = 44.6 mu g/mL), and their preliminary structure-activity relationships were also discussed. (C) 2015 Elsevier B.V. All rights reserved.
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- 2015
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35. Pentacyclic triterpene derivatives possessing polyhydroxyl ring A inhibit Gram-positive bacteria growth by regulating metabolism and virulence genes expression
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Luo Heng, Qi-Ji Li, Dao-Ping Wang, Li-Rong Huang, Xiao-Sheng Yang, Xiao-Jiang Hao, and Jian-Xin Zhang
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Stereochemistry ,Microbial Sensitivity Tests ,Gram-Positive Bacteria ,Real-Time Polymerase Chain Reaction ,Structure-Activity Relationship ,chemistry.chemical_compound ,Ursolic acid ,Triterpene ,Drug Discovery ,Structure–activity relationship ,RNA, Messenger ,Oleanolic acid ,Antibacterial agent ,Pharmacology ,chemistry.chemical_classification ,Virulence ,Reverse Transcriptase Polymerase Chain Reaction ,Organic Chemistry ,Gene Expression Regulation, Bacterial ,General Medicine ,Anti-Bacterial Agents ,chemistry ,Biochemistry ,Peptidoglycan ,Pentacyclic Triterpenes ,Antibacterial activity - Abstract
The hydroxyl group in ring A of pentacyclic triterpene is essential for antibacterial activity. Pentacyclic triterpenes bearing three hydroxyl groups in ring A were mainly found in plants and displayed significant antibacterial activity. However, no study reported how to obtain this type of compounds by chemical modification. In this study, twenty-five new pentacyclic triterpenes bearing polyhydroxyl ring A were synthesized from parental compounds ursolic acid (UA) and oleanolic acid (OA). Here, we showed that most of these derivatives displayed a significantly increased activity against Gram-positive bacteria compared to parental compounds in vitro. Some of these compounds exhibited minimum inhibitory concentration values of 1-3-fold more potent than the positive controls. The structure-activity relationship studies demonstrated that introducing two hydroxyl groups at positions C-1 and C-2 together with a small alkyl ester group at C-17 of UA and OA strongly enhanced growth-inhibiting activity against Gram-positive bacteria. The antibacterial mechanism of the active derivatives was shown to be involved in regulating the expression of genes associated with peptidoglycan and respiratory metabolisms, as well as virulence factor in bacteria. The enhanced potency and unique mechanism of action of these new pentacyclic triterpenes make them a promising antibacterial agent for further studies.
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- 2015
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36. Two Unusual Polycyclic Polyprenylated Acylphloroglucinols, Including a Pair of Enantiomers from Garcinia multiflora
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Jian-Xin Zhang, Lie-Jun Huang, Chen Yan, Xiao-Jiang Hao, Yan Li, Chun-Mao Yuan, Wei Gu, Chonglin Yang, Yuan Ma, Yang Li, Ping Yi, Yi-Min Fan, and Tao Huang
- Subjects
Circular dichroism ,Stereochemistry ,HL-60 Cells ,Stereoisomerism ,Phloroglucinol ,Biochemistry ,HeLa ,chemistry.chemical_compound ,Humans ,Molecule ,Physical and Theoretical Chemistry ,Molecular Structure ,biology ,Chemistry ,Organic Chemistry ,Tridecane ,biology.organism_classification ,Antineoplastic Agents, Phytogenic ,Garcinia multiflora ,Drug Screening Assays, Antitumor ,Enantiomer ,Garcinia ,Lysosomes ,Human cancer ,HeLa Cells - Abstract
Two polycyclic polyprenylated acylphloroglucinols, garcimulins A and B ((+/-)-1 and 2), including a pair of enantiomers with the unique caged tetracyclo[5.4.1.1(1,5).0(9,13)]tridecane skeleton were isolated from Garcinia multiflora. Their structures and absolute configurations were determined by extensive analysis of spectroscopic data and electronic circular dichroism (ECD) calculations. Compounds 1 and 2 exhibited cytotoxic activities against five human cancer cell lines in vitro (IC50 3.42-13.23 mu M). The acidification of lysosomes in HeLa cell was obviously affected by compound 2.
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- 2015
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37. Secondary reaction mechanism of leaching process of calcium aluminate slag
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Huilan Sun, Shu-feng Zong, Jian Xin Zhang, Jia-jia Liu, and Bo Wang
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Reaction mechanism ,Materials science ,Sodium ,Aluminate ,Inorganic chemistry ,technology, industry, and agriculture ,Metals and Alloys ,chemistry.chemical_element ,Calcium ,equipment and supplies ,Geotechnical Engineering and Engineering Geology ,Condensed Matter Physics ,chemistry.chemical_compound ,chemistry ,Materials Chemistry ,Leaching (metallurgy) ,Sodium carbonate ,Hydrate - Abstract
SiO 2 in calcium aluminate slag exists in the form of γ -2CaO·SiO 2 which is more stable than β -2CaO·SiO 2 . However, it is decomposed by sodium carbonate solution during leaching process, leading to the secondary reaction. The extent of secondary reaction and reaction mechanism of calcium aluminate slag were studied using XRD. The results show that the decomposition rate of γ -2CaO·SiO 2 increases with the increase in leaching time and sodium carbonate concentration. The main products of secondary reaction are the mixture of hydrogarnet and sodium hydrate alumina–silicate. SiO 2 concentration rises firstly and then drops with the increase of leaching temperature. XRD results indicate that the stable product of secondary reaction at low temperature is hydrogarnet. But hydrogarnet is transformed into sodium hydrate alumina–silicate at high temperature.
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- 2015
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38. A modified fluoro-Pummerer reaction with DAST and NIS for synthesis of β-amino-α-fluoro-sulfides from corresponding β-amino-sulfides
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Zhanxing Hu, Chen Hongju, Bixue Xu, Guangyi Liang, and Jian-Xin Zhang
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Butyl carbamate ,Carbamate ,Stereochemistry ,Pummerer rearrangement ,medicine.medical_treatment ,Organic Chemistry ,Substrate (chemistry) ,Biochemistry ,Diethylaminosulfur trifluoride ,Phthalimide ,chemistry.chemical_compound ,chemistry ,Drug Discovery ,medicine ,Fluoride - Abstract
An efficient and convenient method was developed for the synthesis of β-amino-α-fluoro-sulfides in one-step from corresponding β-amino-sulfides by using N -iodosuccinimide (NIS) and diethylaminosulfur trifluoride (DAST) as a fluoride source. This fluorination method was verified on various β-amino-sulfides substrate contained different function groups, such as N -phthalimide (NPhth), N -acetyl, N -benzoyl, N -( tert -butyl carbamate) ( N -Boc), N -(benzyl carbamate) ( N -Cbz), and methoxycarbonyl substitution groups.
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- 2015
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39. Schisanhenol derivatives and their biological evaluation against tobacco mosaic virus (TMV)
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Jian-Xin Zhang, Shu-Zhen Mu, Lulu Deng, Jia-Ju Liu, Xiao-Jiang Hao, and Qing-Yao Wang
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Pharmacology ,Curative effect ,Molecular Structure ,Stereochemistry ,Chemical modification ,General Medicine ,Schisanhenol ,Biology ,Antiviral Agents ,Lignans ,Tobacco Mosaic Virus ,Cyclooctanes ,Structure-Activity Relationship ,Tobacco mosaic virus TMV ,Virucide ,Plant virus ,Drug Discovery ,Tobacco mosaic virus ,Polycyclic Compounds ,Biological evaluation - Abstract
Schisanhenol (Sol) was isolated from Schisandra rubriflora, and a series of derivatives (1–16, 15a-16a, and 15b-16b) were designed and prepared by chemical modification. The curative and protective effects of these dibenzocyclooctadiene lignan analogues against tobacco mosaic virus (TMV) were evaluated. Most analogues exhibited stronger protective effects than the positive control ningnanmycin. Dibromoschisanhenol (6) at 0.25 mM exhibited the strongest protective activity (83.5 ± 1.8% at 0.25 mM), and 14-(3, 5-dibenzyloxy)-benzoyloxyschisanhenol (16) showed a significant curative effect (78.0 ± 3.8% at 0.15 mM) that was much stronger than that of the commercial virucide ningnanmycin. This study is the first to demonstrate that natural dibenzocyclooctadiene lignans and analogues are active against plant viruses.
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- 2015
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40. Effect of hydrogen sulfide on inflammatory cytokines in acute myocardial ischemia injury in rats
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Lan‑Fang Li, Fang Liu, Gang Zhang, Jian‑Xin Zhang, Guang‑Jie Liu, and Na Liu
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Cancer Research ,Pathology ,medicine.medical_specialty ,hydrogen sulfide ,Ischemia ,Sodium hydrosulfide ,Nitric oxide ,Proinflammatory cytokine ,chemistry.chemical_compound ,Immunology and Microbiology (miscellaneous) ,Internal medicine ,Medicine ,rat ,business.industry ,Interleukin ,inflammatory factor ,Articles ,General Medicine ,medicine.disease ,Endocrinology ,chemistry ,Apoptosis ,Tumor necrosis factor alpha ,Sample collection ,acute myocardial ischemia ,business - Abstract
Hydrogen sulfide (H2S) is believed to be involved in numerous physiological and pathophysiological processes, and now it is recognized as the third endogenous signaling gasotransmitter, following nitric oxide and carbon monoxide; however, the effects of H2S on inflammatory factors in acute myocardial ischemia injury in rats have not been clarified. In the present study, sodium hydrosulfide (NaHS) was used as the H2S donor. Thirty-six male Sprague Dawley rats were randomly divided into five groups: Sham, ischemia, ischemia + low-dose (0.78 mg/kg) NaHS, ischemia + medium-dose (1.56 mg/kg) NaHS, ischemia + high-dose (3.12 mg/kg) NaHS and ischemia + propargylglycine (PPG) (30 mg/kg). The rats in each group were sacrificed 6 h after the surgery for sample collection. Compared with the ischemia group, the cardiac damage in the rats in the ischemia + NaHS groups was significantly reduced, particularly in the high-dose group; in the ischemia + PPG group, the myocardial injury was aggravated compared with that in the ischemia group. Compared with the ischemia group, the levels of interleukin (IL)-1β, IL-6 and tumor necrosis factor-α (TNF-α) in the serum of rats in the ischemia + medium- and high-dose NaHS groups were significantly reduced, and the expression of intercellular adhesion molecule-1 (ICAM-1) mRNA and nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) protein in the myocardial tissues of rats was significantly reduced. In the ischemia + PPG group, the TNF-α, IL-1β and IL-6 levels in the serum were significantly increased, the expression of ICAM-1 mRNA was increased, although without a significant difference, and the expression of NF-κB was increased. The findings of the present study provide novel evidence for the dual effects of H2S on acute myocardial ischemia injury via the modulation of inflammatory factors.
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- 2015
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41. Host–guest interactions of thiabendazole with normal and modified cucurbituril: 1H NMR, phase solubility and antifungal activity studies
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Xin Xiao, Zhu Tao, Qing Tang, Qian-Jiang Zhu, Qing Liu, Sai-Feng Xue, Jian-Xin Zhang, Ying Huang, Gang Wei, and Yun-Yun Xi
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Benzimidazole ,chemistry.chemical_compound ,Aqueous solution ,chemistry ,Stereochemistry ,Cucurbituril ,Proton NMR ,Molecule ,Moiety ,General Chemistry ,Solubility ,Thiazole ,Medicinal chemistry - Abstract
Guest–host inclusion complexes between thiabendazole (TBZ) and cucurbit[7]uril (Q[7]), symmetrical tetra-methylcucurbit[6]uril (TMeQ[6]) and meta-hexamethyl-substituted cucurbit[6]uril (HMeQ[6]) in aqueous solution were investigated by 1H NMR spectroscopy and phase solubility studies. The antifungal activities of the inclusion complexes were also determined. Analysis of the 1H NMR spectra revealed that the host Q[7] selectively binds the benzimidazole ring moiety of the guest molecule and that the thiazole ring is encapsulated into the cavities of TMeQ[6] and HMeQ[6]. Phase solubility diagrams were analysed using rigorous procedures to obtain estimates of the complex formation constants for Q[n]-TBZ complexation. The phase solubility studies showed that TBZ solubility increased as a function of Q[7], TMeQ[6] and HMeQ[6] concentrations. We found that complexation of TBZ with Q[n] increased the inhibitory effect of TBZ on the growth of Fusarium graminearum. Our results thus demonstrate that complexation of TBZ with Q[n] could be used to improve the solubility and antifungal activity of TBZ.
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- 2015
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42. Direct syntheses of cucurbit[7]uril-anchored polyacrylic acid microspheres and adsorption of basic dyes by the derivative
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Qian Jiang Zhu, Qing-di Zhou, Ying Fan, Sai Feng Xue, Zhu Tao, Rui Han Gao, Bo Xiao, Jian-Xin Zhang, and Chen Peng
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chemistry.chemical_classification ,General Chemical Engineering ,Polyacrylic acid ,Salt (chemistry) ,General Chemistry ,Polymer ,Nanocapsules ,chemistry.chemical_compound ,Adsorption ,chemistry ,Polymer chemistry ,Organic chemistry ,Ammonium persulfate ,Absorption (chemistry) ,Acrylic acid - Abstract
A one-pot strategy was employed to synthesize a series of water-soluble cucurbit[7]uril-anchored polyacrylic acids (Q[7]-anchored PAAs) with high yields in the presence of an ammonium persulfate salt as both an initiator and an oxidant. The effects of acrylic acid, Q[7] feed mass and APS concentration on the formation of polymer nanocapsules have been investigated. The Q[7]-anchored PAAs can be further esterified with 2-naphthol to yield water-insoluble derivatives, which are characteristic of the stationary phase for absorption of basic dyes, especially neutral red.
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- 2015
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43. A host–guest complexation based fluorescent probe for the detection of paraquat and diquat herbicides in aqueous solutions
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Sai-Feng Xue, Ying Huang, Zhu Tao, Gui-Xian Song, Qing Tang, Xin-Long Ni, Ruibing Wang, Yun-Yun Xi, and Jian-Xin Zhang
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Detection limit ,Aqueous solution ,Chemistry ,General Chemical Engineering ,Metal ions in aqueous solution ,Analytical chemistry ,Isothermal titration calorimetry ,General Chemistry ,Nuclear magnetic resonance spectroscopy ,Fluorescence ,Diquat ,chemistry.chemical_compound ,Ternary complex ,Nuclear chemistry - Abstract
The supramolecular interactions among thioflavin T (ThT), two herbicides paraquat (PQ) and diquat (DQ), and macrocyclic cucurbit[8]uril (Q[8]), were studied using spectrofluorimetry, ultraviolet-visible absorbance spectrometry, 1H nuclear magnetic resonance spectroscopy, and isothermal titration calorimetry. A new method based on fluorescence quenching of the fluorescent host–guest complexes of Q[8]–ThT (the probe) upon cooperative binding with PQ or DQ to form a ternary complex, was proposed for the analytical determination of the two herbicides in aqueous solutions. Detection limits of 7.95 × 10−9 mol L−1 and 8.07 × 10−9 mol L−1 were obtained for PQ and DQ, respectively. Recoveries obtained by the proposed method in real-world examples such as river water and cabbage extracts were 104–108%. Interestingly, this method demonstrated high selectivity towards PQ and DQ in the presence of various metal ions and quaternary ammonium substances. Such a method provides a rapid, selective, sensitive and facile strategy for herbicides detection and quantification.
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- 2015
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44. Direct synthesis of cucurbit[5]uril-anchored polyacrylic acid microspheres and potential applications in selective sorption
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Qian-Jiang Zhu, Sai-Feng Xue, Ying Fan, Zhu Tao, Rui-Han Gao, Qing-di Zhou, Bo Xiao, Jian-Xin Zhang, and Chen Peng
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chemistry.chemical_classification ,General Chemical Engineering ,Polyacrylic acid ,Radical polymerization ,General Chemistry ,Polymer ,Nanocapsules ,chemistry.chemical_compound ,Monomer ,Polymerization ,chemistry ,Polymer chemistry ,Ammonium persulfate ,Acrylic acid - Abstract
A one-pot strategy was employed to synthesize a series of cucurbit[5]uril-anchored (Q[5]-anchored) polymers with high yields. The acrylic acid (AA) monomer, an ammonium persulfate salt (APS) initiator, and an oxidant were used in the polymerization. The Q[5]-anchored polyacrylic acid aggregates (Q[5]-PAA) have been characterized by 1H NMR, 13C NMR, 2D NMR, FTIR, TGA, GPC, TEM and SEM measurements. The experimental results confirm that PAA chains can be grafted to Q[5] in a controlled manner through an in situ radical polymerization approach. The effects of acrylic acid and Q[5] feed mass and APS concentration on the formation of polymer nanocapsules have been investigated. The experiments reveal that the feed mass of acrylic acid greatly influences the properties of Q[5]-PAA when the ratio of Q[5]/APS is fixed at 0.5. In particular, when APS/Q[5] = 46 and 72, vesicle structures are observed in the Q[5]-anchored polymers. Moreover, such polymer nanocapsules show selective absorption of some volatile compounds, particularly methanol.
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- 2015
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45. General model of optical frequency conversion in homogeneous media: Application to second-harmonic generation in an ε -near-zero waveguide
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Liu Yang Zhang, Xin Lu Zhang, Jinjer Huang, and Jian Xin Zhang
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Physics ,Field (physics) ,business.industry ,Second-harmonic generation ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Waveguide (optics) ,Integral equation ,Computational physics ,Optics ,0103 physical sciences ,Radiative transfer ,Wave impedance ,010306 general physics ,0210 nano-technology ,business ,Absorption (electromagnetic radiation) ,Refractive index - Abstract
Traditional optical frequency conversion model is well improved in this work. In terms of the dyadic Green's function method, a set of coupled-amplitude equations is reduced under a proposed transition layer assumption, accompanying the simultaneous integral equations. The model, as a generalization of the current frequency conversion theory, is aimed at any one-dimensional thin film or bulk nonlinear structure, allowing for arbitrary optical anisotropy and absorption without pumping and propagating limitations. The assumption reasonably simplifies the strict nonlinear boundary conditions and enables the equations to yield exact radiative field solutions. A field-enhanced phase-matching configuration is designed for second harmonic generation in a lossy $\ensuremath{\epsilon}$-near-zero material. The high contrast of refractive indices between a substrate (silicon) and the material traps the harmonic wave inside and constructs a natural mirror reflection waveguide. A simulation in the lowest guided mode predicts an efficiency enhancement proportional to the relative wave impedance to the fifth power under a resonant condition.
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- 2017
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46. Prevalence and Years of Life Lost due to Disability from Dental Caries among Children and Adolescents in Western China, 1990-2015
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Zhuo, Wang, Ying, Deng, Shi Wei, Liu, Jun, He, Kui, Ji, Xin Ying, Zeng, Shu Juan, Yang, Xin Yin, Xu, Yu, Luo, Mai Geng, Zhou, and Jian Xin, Zhang
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Male ,China ,Adolescent ,Child, Preschool ,Prevalence ,Humans ,Disabled Persons ,Female ,Dental Caries ,Child - Abstract
To analyze the prevalence and years lived with disability (YLD) from dental caries among children and adolescents and the time trends over the past two decades in Sichuan province, the largest province in west China.Based on the Global Burden of Disease Study 2015 (GBD2015), which systematically assessed the epidemiological characteristics of major diseases and their transitions by country and region from 1990 to 2015, we extracted the estimated results for China. We then used the Bayesian meta-regression method to estimate the sex- and age-specific prevalences and YLDs from dental caries among children and adolescents under 15 years old in Sichuan province and compared them with global and national indicators for the same period.In 2015, there were almost 6 million cases of dental caries in children and adolescents (aged15 years) in Sichuan province, accounting for 6% of the total cases in China. For children under 5 years, the prevalence of deciduous caries was 55.9%, and the YLDs value was 10.8 per 100,000, while it was 24.3% and 5.1 per 100,000 respectively among 5- to 14-year-olds; for those aged 5 to 14 years, the prevalence of permanent caries was 21.5%, and the YLDs value was 11.5 per 100,000. From 1990 to 2015, the prevalence of dental caries for children under 5 years increased substantially, by 16.2%, and the YLDs increased by 8.7%. Among those aged 5 to 14 years, the prevalence increased and the YLDs decreased.Dental caries remains a huge health burden in Western China. In contrast to the global and national data, the trend has increased rapidly over the past 25 years in this region. This work provides suggestions for the prevention and control for oral health in China with the policy of two-child.
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- 2017
47. Coordination of Alkaline‐Earth Metal Ions in Inverted Cucurbit[6]uril Supramolecular Assemblies Formed in the Presence of Tetrachloride Zincates
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Yun-Qian Zhang, Zhu Tao, Sai-Feng Xue, Tao Sun, Qian-Jiang Zhu, Zhang Deqing, and Jian-Xin Zhang
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Inorganic Chemistry ,chemistry.chemical_classification ,Alkaline earth metal ,Crystallography ,Aqueous solution ,Chemistry ,Tetrachloride ,Supramolecular chemistry ,Polymer ,Supramolecular assembly ,Ion ,Zincate - Abstract
Coordination in supramolecular assemblies in aqueous HCl solutions was investigated by reacting alkaline-earth cations (AE2+) and inverted cucurbit[6]uril (iQ[6]) in the presence of the structure-directing agent, tetrachloride zincate ion. Single-crystal X-ray diffraction analysis revealed that the iQ[6]–Mg2+–[ZnCl4]2––HCl interaction system yielded a supramolecular assembly of iQ[6] and [ZnCl4]2– without forming coordination complexes of Mg2+ or Zn2+ with iQ[6]. In contrast, interaction of Ca2+ or Sr2+ with iQ[6] in the presence of [ZnCl4]2– gave rise to linear coordination polymers, which formed a honeycomb-like framework in which the linear polymers occupy cells of the framework. The iQ[6]–Ba2+–[ZnCl4]2––HCl interaction system immediately produced precipitates, thus preventing isolation of single crystals under similar synthetic conditions.
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- 2014
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48. Rhodamine-triazine based probes for Cu2+ in aqueous media and living cells
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Xi Zeng, Yi Chen, Gang Wei, Yan Zhang, Jian-Xin Zhang, Carl Redshaw, and Lan Mu
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Fluorescence-lifetime imaging microscopy ,Fluorophore ,Molecular logic gate ,Metal ions in aqueous solution ,Cyanuric chloride ,Metals and Alloys ,Analytical chemistry ,Condensed Matter Physics ,Photochemistry ,Fluorescence ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Rhodamine ,chemistry.chemical_compound ,chemistry ,Materials Chemistry ,Electrical and Electronic Engineering ,Instrumentation ,Triazine - Abstract
The performance of a number of rhodamine-triazine derivatives (probe R1–R4) which utilize rhodamine as the fluorophore with cyanuric chloride as the molecular platform have been evaluated. Spectroscopic analysis revealed that differing structural substitution patterns of the probe resulted in different sensitivity and selectivity for specific metal ions. The probes R1 and R2 were fluorescent/colorimetric probes for Cu2+, whilst R3 and R4 were probes for Al3+, Cr3+ and Fe3+. The probe R2 exhibited superior recognition for Cu2+ in neutral aqueous medium, and the optical switching behavior of R2 for Cu2+ and S2− could be used to construct a molecular logic gate. In addition, fluorescence imaging of probe R2 for Cu2+ in living cells was demonstrated.
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- 2014
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49. Synthesis and fluorescence properties of a 1,3-disubstituted thiacalix[4]arene crown-5 armed with phenothiazine moieties
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Qiang Sun, Jian-Xin Zhang, Jiang-Lin Zhao, Takehiko Yamato, Xi Zeng, and Lan Mu
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Infrared ,Metal ions in aqueous solution ,General Chemistry ,Photochemistry ,Fluorescence ,Fluorescence spectroscopy ,Ion ,chemistry.chemical_compound ,symbols.namesake ,chemistry ,Phenothiazine ,Stokes shift ,Mass spectrum ,symbols - Abstract
A new thiacalix[4]arene phenothiazine derivative (2) based on a thiacalix[4]crown with a 1,3-alternate conformation has been synthesized and characterized. In THF-water mixture, Compound 2 exhibits a strong fluorescence emission, with a large Stokes shift (λex/em = 357 nm/505 nm, Δλ = 148 nm), which helps to avoid interference in excitation and emission. For the metal ions tested, the fluorescence of Compound 2 was quenched only by Fe3+ and Cr3+ ions. Evidence for the hydrolysis reaction promoted by the metal ions is given by X-ray crystallography, mass spectra (MS), infrared (IR) spectra, and fluorescence spectroscopy data.
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- 2014
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50. Seco-pregnane steroidal glycosides from the roots of Cynanchum atratum and their anti-TMV activity
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Chen Yan, Xiao-Jiang Hao, Jian-Xin Zhang, Ying Yan, Lie-Jun Huang, Tao Huang, Kai-xing Liu, Sheng Liu, and Shu-Zhen Mu
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Steroidal glycosides ,Stereochemistry ,Positive control ,Microbial Sensitivity Tests ,Coat protein ,Antiviral Agents ,Plant Roots ,chemistry.chemical_compound ,Western blot ,Tobacco ,Drug Discovery ,medicine ,Tobacco mosaic virus ,Secosteroids ,Glycosides ,Plant Diseases ,Pharmacology ,Molecular Structure ,Mosaic virus ,medicine.diagnostic_test ,Chemistry ,Pregnane ,Phytosterols ,Vincetoxicum ,General Medicine ,Saponins ,Tobacco Mosaic Virus ,Cynanchum atratum - Abstract
Fifteen new seco -pregnane steroidal glycosides cynanosides A–O ( 1 – 15 ) together with twenty-seven known ones were isolated from the roots of Cynanchum atratum . The structures of 1 – 15 were determined by extensive analysis of spectroscopic data. The anti-tobacco mosaic virus (TMV) activity of these steroidal glycosides was screened by the conventional half-leaf method, enzyme-linked immunosorbent assay, and Western blot methods, most of them showed potent anti-TMV activity. Among them, compounds 1 , 7 , 13 , 28 and 31 showed significantly anti-TMV activity with an IC 50 value of 20.5, 18.6, 22.0, 19.2 and 22.2 μg/mL, respectively, and were much more effective than the positive control, ningnanmycin (IC 50 = 49.6 μg/mL).
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- 2014
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