48 results on '"Li, Liuyi"'
Search Results
2. Multiple Heteroatom-Hydrogen Bonds Bridging Electron Transport in Covalent Organic Framework-Based Supramolecular System for Photoreduction of CO 2 .
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He Y, Zhao Y, Wang X, Liu Z, Yu Y, and Li L
- Abstract
Supramolecular systems consisting of covalent organic frameworks (COFs) and Ni complex are designed for robust photocatalytic reduction of CO
2 . Multiple heteroatom-hydrogen bonding between the COF and Ni complex is identified to play a decisive role in the photoexcited electron transfer across the liquid-solid interface. The diminution of steric groups on COF or metal complex can optimize catalytic performance, which is more attributable to the enhanced hydrogen-bond interaction rather than their intrinsic activity. The photosystem with relatively strong strength of hydrogen bonds exhibits remarkable photocatalytic CO2 -to-CO conversion, far superior to photosystems with supported atomic Ni or metal complex alone in the absence of hydrogen-bond effect. Such heteroatom-hydrogen bonds bridging electron transport pathway confers supramolecular system with high photocatalytic performance, providing an avenue to rationally design efficient and steadily available photosystems., (© 2023 Wiley-VCH GmbH.)- Published
- 2023
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3. Build-in electric field in CuWO 4 /covalent organic frameworks S-scheme photocatalysts steer boosting charge transfer for photocatalytic CO 2 reduction.
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Niu Q, Chen Q, Huang G, Li L, He Y, and Bi J
- Abstract
Covalent organic frameworks (COFs) are crystalline porous materials with enormous potential for realizing solar-driven CO
2 -to-fuel conversion, yet the sluggish transfer/separation of photoinduced electrons and holes remains a compelling challenge. Herein, a step (S)-scheme heterojunction photocatalyst (CuWO4 -COF) was rationally fabricated by a thermal annealing method for boosting CO2 conversion to CO. The optimal CuWO4 /COF composite sample, integrating 10 wt% CuWO4 with an olefin (C═C) linked COF (TTCOF), achieved a remarkable gas-solid phase CO yield as high as 7.17 ± 0.35 μmol g-1 h-1 under visible light irradiation, which was significantly higher than the pure COF (1.6 ± 0.29 μmol g-1 h-1 ). The enhanced CO2 conversion rate could be attributable to the interface engineering effect and the formation of internal electric field (IEF) directing from TTCOF to CuWO4 according to the theoretical calculation and experimental results, which also proves the electrons transfer from TTCOF to CuWO4 upon hybridization. In addition, driven by the IEF, the photoinduced electrons can be steered from CuWO4 to TTCOF under visible light irradiation as well-elucidated by in-situ irradiated X-ray photoelectron spectroscopy, verifying the S-scheme charge transfer pathway over CuWO4 /COF composite heterojunctions, which greatly foster the photoreduction activity of CO2 . The preparation technique of the S-scheme heterojunction photocatalyst in this study provides a paradigmatic protocol for photocatalytic solar fuel generation., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)- Published
- 2023
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4. Single-Atom Engineering of Covalent Organic Framework for Photocatalytic H 2 Production Coupled with Benzylamine Oxidation.
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Xia Y, Zhu B, Li L, Ho W, Wu J, Chen H, and Yu J
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In photocatalysis, reducing the exciton binding energy and boosting the conversion of excitons into free charge carriers are vital to enhance photocatalytic activity. This work presents a facile strategy of engineering Pt single atoms on a 2D hydrazone-based covalent organic framework (TCOF) to promote H
2 production coupled with selective oxidation of benzylamine. The optimised TCOF-Pt SA photocatalyst with 3 wt% Pt single atom exhibited superior performance to TCOF and TCOF-supported Pt nanoparticle catalysts. The production rates of H2 and N-benzylidenebenzylamine over TCOF-Pt SA3 are 12.6 and 10.9 times higher than those over TCOF, respectively. Empirical characterisation and theoretical simulation showed that the atomically dispersed Pt is stabilised on the TCOF support through the coordinated N1 -Pt-C2 sites, thereby induing the local polarization and improving the dielectric constant to reach the low exciton binding energy. These phenomena led to the promotion of exciton dissociation into electrons and holes and the acceleration of the separation and transport of photoexcited charge carriers from bulk to the surface. This work provides new insights into the regulation of exciton effect for the design of advanced polymer photocatalysts., (© 2023 Wiley-VCH GmbH.)- Published
- 2023
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5. OTO-Net: An Automated MRA Image Segmentation Network for Intracranial Aneurysms.
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Ye J, Xu X, Li L, Zhao J, Lai W, Zhou W, Zheng C, Wang X, and Lai X
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- Humans, Image Processing, Computer-Assisted, Magnetic Resonance Imaging, Intracranial Aneurysm diagnostic imaging
- Abstract
Intracranial aneurysms are local dilations of the cerebral blood vessels; people with intracranial aneurysms have a high risk to cause bleeding in the brain, which is related to high mortality and morbidity rates. Accurate detection and segmentation of intracranial aneurysms from Magnetic Resonance Angiography (MRA) images are essential in the clinical routine. Manual annotations used to assess the intracranial aneurysms on MRA images are substantial interobserver variability for both aneurysm detection and assessment of aneurysm size and growth. Many prior automated segmentation works have focused their efforts on tackling the problem, but there is still room for performance improvement due to the significant variability of lesions in the location, size, structure, and morphological appearance. To address these challenges, we propose a novel One-Two-One Fully Convolutional Networks (OTO-Net) for intracranial aneurysms automated segmentation in MRA images. The OTO-Net uses full convolution to achieve intracranial aneurysms automated segmentation through the combination of downsampling, upsampling, and skip connection. In addition, loss ensemble is used as the objective function to steadily improve the backpropagation efficiency of the network structure during the training process. We evaluated the proposed OTO-Net on one public benchmark dataset and one private dataset. Our proposed model can achieve the automated segmentation accuracy with 98.37% and 97.86%, average surface distances with 1.081 and 0.753, dice similarity coefficients with 0.9721 and 0.9813, and Hausdorff distance with 0.578 and 0.642 on these two datasets, respectively., Competing Interests: No conflicts of interests, financial or otherwise, are declared by the authors., (Copyright © 2022 Jianming Ye et al.)
- Published
- 2022
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6. Effectiveness of self-efficacy-enhancing interventions on rehabilitation following total hip replacement: a randomized controlled trial with six-month follow-up.
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Meng Y, Deng B, Liang X, Li J, Li L, Ou J, Yu S, Tan X, Chen Y, and Zhang M
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- Follow-Up Studies, Humans, Prospective Studies, Quality of Life, Self Efficacy, Arthroplasty, Replacement, Hip rehabilitation
- Abstract
Background: As the world's population ages, hip replacement, a routine treatment for arthritis, has become more common. However, after surgery, rehabilitation has some limited effectiveness with postoperative complications and persistent impairments. This study aimed to explore the effect of a self-efficacy-enhancing intervention program following hip replacement on patients' rehabilitation outcomes (self-efficacy, functional exercise compliance, hip function, activity and social participation, anxiety and depression, and quality of life)., Methods: A prospective randomized controlled trial with a repeated-measures, two-group design was conducted in a grade A general hospital in Guangdong Province, China. A total of 150 participants with a unilateral total hip replacement were recruited via convenience sampling. Participants were randomly assigned to either the self-efficacy enhancing intervention group (n = 76) or the control group (n = 74). The intervention encompassed a face-to-face education before discharge and four telephone-based follow-ups in six months after surgery. Researchers collected baseline data on one to three days after surgery, and outcomes data were collected one, three, and six months after surgery., Results: Average age (deviation) in intervention and control group were 58 (10.32) and 59 (10.82), respectively. After six months, intervention group scored 86.83 ± 5.89 in rehabilitation self-efficacy, significantly higher than control group (72.16 ± 6.52, t = -10.820, p < 0.001) and their hip function has turned to "excellent" (90.52 ± 4.03), while that of the latter was limited to a "middle" level (78.47 ± 7.57). Statistically significant differences were found in secondary outcomes (p < 0.001). The advantage of intervention in improving quality of life was seen in the long term rather than in the early postoperative period., Conclusions: The self-efficacy-enhancing intervention performed by nurses induced better exercise compliance and physical, psychological, and social functions after hip replacement compared with routine care. We recommend such interventions to be combined with routine care soon after hip replacement. Further research should focus on the social participation of patients with hip replacement. Trial registration Retrospectively registered at Chinese Clinical Trial Registry (31/01/2020, No. ChiCTR2000029422, http://www.chictr.org.cn/index.aspx )., (© 2022. The Author(s).)
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- 2022
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7. Automated Segmentation of Mass Regions in DBT Images Using a Dilated DCNN Approach.
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Ye J, Yang W, Wang J, Xu X, Li L, Xie C, Chen G, Wang X, and Lai X
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- Breast diagnostic imaging, Female, Humans, Imaging, Three-Dimensional, Neural Networks, Computer, Breast Neoplasms diagnostic imaging, Mammography
- Abstract
To overcome the limitations of conventional breast screening methods based on digital mammography, a quasi-3D imaging technique, digital breast tomosynthesis (DBT) has been developed in the field of breast cancer screening in recent years. In this work, a computer-aided architecture for mass regions segmentation in DBT images using a dilated deep convolutional neural network (DCNN) is developed. First, to improve the low contrast of breast tumour candidate regions and depress the background tissue noise in the DBT image effectively, the constraint matrix is established after top-hat transformation and multiplied with the DBT image. Second, input image patches are generated, and the data augmentation technique is performed to create the training data set for training a dilated DCNN architecture. Then the mass regions in DBT images are preliminarily segmented; each pixel is divided into two different kinds of labels. Finally, the postprocessing procedure removes all false-positives regions with less than 50 voxels. The final segmentation results are obtained by smoothing the boundaries of the mass regions with a median filter. The testing accuracy (ACC), sensitivity (SEN), and the area under the receiver operating curve (AUC) are adopted as the evaluation metrics, and the ACC, SEN, as well as AUC are 86.3%, 85.6%, and 0.852 for segmenting the mass regions in DBT images on the entire data set, respectively. The experimental results indicate that our proposed approach achieves promising results compared with other classical CAD-based frameworks., Competing Interests: No conflicts of interests, financial or otherwise, are declared by the authors., (Copyright © 2022 Jianming Ye et al.)
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- 2022
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8. Multi-center prospective study on central line-associated bloodstream infections in 79 ICUs of China.
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Zeng C, Wu A, Li L, and Jia H
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- Child, Humans, Intensive Care Units, Prospective Studies, Retrospective Studies, Catheter-Related Infections epidemiology, Sepsis epidemiology
- Abstract
Background: China has not yet established a national surveillance network such as NHSN from America, so there is still no large-scale investigations on central line-associated bloodstream infection (CLABSI) incidence. Several retrospective studies in China reported that the incidence of CLABSI varied due to inconsistent diagnostic criteria. We performed a nationwide survey to investigate the utilization rate of central venous catheters (CVCs) and the incidence of CLABSI in ICUs of different areas of China., Methods: This is a prospective multi-center study. Patients admitted to ICUs with the use of CVCs between January 1, 2014 and December 31, 2018 were enrolled in this study. Hospitals were given the definition of catheter-related bloodstream infection as: a laboratory-confirmed bloodstream infection where CVC was in place on the date of event or the day before. The characteristics of patients, information of catheterization, implementation rates of precautions, and CLABSIs were collected. The statistical analysis was performed by SPSS 25.0 software and website of Open Source Epidemiologic Statistics for Public Health., Results: A total of 38,212 patients and 466,585 catheter days were involved in surveillance. The average CLABSI incidence in a thousand catheter days was 1.50, the lowest incidence unit was in pediatric ICU (0/1000 catheter days), and the lowest incidence area was in Northeast China (0.77/1000 catheter days), while the highest incidence unit was in cardiac ICU (2.48/1000 catheter days) and the highest incidence area was in Eastern China (1.62/1000 catheter days). The average utilization rate of CVC was 42.85%, the lowest utilization rate was in pediatric ICU (5.85%) and in Central China (38.05%), while the highest utilization rate was in surgical ICU (64.92%) and in Western China (51.57%). Among the 702 CLABSI cases reported, a total of 735 strains of pathogens were cultured. Staphylococcus spp. was the most common organism isolated (27.07%), followed by Enterobacteriaceae (22.31%). The implementation rates of all precautions showed an upward trend during the study period (P ≤ 0.001)., Conclusion: The average incidence of CLABSI in ICUs in China is 1.5/1000 catheter days, similar to the rates reported in developed countries but lower than previous reports in China. CLABSI incidence showed regional differences in China. It is necessary to implement targeted surveillance of CLABSI cases by using standardized CLABSI surveillance definitions and methodologies., (© 2021. The Author(s).)
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- 2021
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9. Crystalline Covalent Organic Frameworks with Tailored Linkages for Photocatalytic H 2 Evolution.
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Wu S, Pan Y, Lin H, Li L, Fu X, and Long J
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Crystalline covalent organic frameworks (COFs) are porous polymeric semiconductors with network topologies, which are built from the integration of selected organic blocks with covalent bond linkages. They have shown great promise for artificial photosynthesis, owing to broad light harvesting, high crystallinity, and high carrier mobility. This Minireview introduces state-of-the-art COF photocatalysts based on different linkages and discusses the origin of photocatalytic activities for hydrogen evolution. Three typical COF photocatalysts, with linkages including imine (-C=N-), β-ketoenamine (O=C-C=C-NH-), and vinylene (-C=C-), are discussed with a particular focus on the advancements in synthetic methodologies and structural design, as well as photoelectronic properties that are relevant to photocatalytic performance. The Minireview is expected to elucidate their structure-property relationships and the way to design photoactive COFs with enhanced performances., (© 2021 Wiley-VCH GmbH.)
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- 2021
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10. Donor-Acceptor Pairs in Covalent Organic Frameworks Promoting Electron Transfer for Metal-Free Photocatalytic Organic Synthesis.
- Author
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Qiu W, He Y, Li L, Liu Z, Zhong S, and Yu Y
- Abstract
The donor-acceptor-type covalent organic frameworks (COFs) have recently gained increasing interest in photocatalysis, but the photoinduced electron-transfer regimes in the COFs are underexplored. Herein, we demonstrate a designed porphyrinic COF possessing a donor-acceptor structure together with its photocatalytic performance in aerobic coupling of primary amines. The COF could be photoexcited by the full range of visible light to generate electron-hole pairs that could be separated by donor-acceptor pairs. Electron transfer as the mechanism of the reaction from anthracene unit to porphyrin unit was revealed by natural transition orbitals analyses. The electrons migrate to the adsorbed O
2 to generate reactive oxidative species. The COF displays remarkable photocatalytic activities in the coupling of amines to imines, which can be explained mainly by the sufficient charge separation and mobility, benefiting from the donor-acceptor pairs in the COF and their interactions to the reactants and intermediates.- Published
- 2021
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11. The Guiding Significance of the Number of Positive Sentinel Lymph Nodes in Frozen Section for Intraoperative Axillary Dissection in Early Breast Cancer.
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Liang C, Li L, Zhu M, Hu J, and Yu Y
- Abstract
Purpose: The results of large randomised trials have changed the treatment strategy of axillary lymph nodes. Axillary lymph node dissection (ALND) can be avoided in some patients with one to two sentinel lymph nodes (SLNs) metastasis based on final paraffin section (FPS) results which called into question the need for intraoperative frozen section (FS). This study aims to assess the guiding value of the number of positive SLN detected via FS for intraoperative ALND., Patients and Methods: This study retrospectively analyzed data from 3303 patients with breast cancer who underwent SLN biopsy between 2015 and 2019. Combined with the FPS results, FS sensitivity, specificity, and false negative rate (FNR) were calculated and the difference in the number of positive SLNs between FS and FPS was analyzed., Results: The overall FNR of FS was 23.21%, which was 76.47% in isolated tumor cells, 62.28% in micrometastasis, and 12.09% in macrometastatic disease. The size of SLN metastasis were significantly associated with a higher FNR (p<0.001). The accuracy rate of the number of positive SLNs detected via FS was 92.62%. Human epidermal growth factor receptor 2 (HER2) (p<0.03) and Ki67 (p<0.02) were significant factors affecting the accuracy rate., Conclusion: FS is a effective method for SLN biopsy, ALND can be avoided in patients with one or two positive SLNs detected via FS., Competing Interests: The authors report no conflicts of interest in this work., (© 2021 Liang et al.)
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- 2021
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12. HER2-intronic miR-4728-5p facilitates HER2 expression and accelerates cell proliferation and migration by targeting EBP1 in breast cancer.
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Zhou Y, Yuan Y, Li L, Wang X, Quan Y, Liu C, Yu M, Hu X, Meng X, Zhou Z, Zhang CY, Chen X, Liu M, and Wang C
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- Carcinogenesis genetics, Cell Line, Tumor, Cell Proliferation genetics, Down-Regulation genetics, Humans, Kaplan-Meier Estimate, MCF-7 Cells, Adaptor Proteins, Signal Transducing genetics, Breast Neoplasms genetics, Breast Neoplasms pathology, Cell Movement genetics, Introns genetics, MicroRNAs genetics, RNA-Binding Proteins genetics, Receptor, ErbB-2 genetics
- Abstract
HER2 amplification greatly contributes to the tumorigenesis of multiple cancers. Intronic miR-4728-5p is transcribed along with its host gene HER2. However, little is known about the role of miR-4728-5p in cancer. This study aims to elucidate the potential role of miR-4728-5p and the underlying mechanism in breast cancer. Kaplan-Meier analysis showed that higher expression of HER2 led to worse survival outcomes in breast cancer patients. The TCGA dataset revealed that compared to normal breast tissues, HER2 and miR-4728-5p levels were significantly upregulated in breast cancer tissues with a positive correlation. In functional assays, miR-4728-5p was confirmed to promote the proliferation and migration in breast cancer cell BT474. EBP1 was identified as a direct target of miR-4728-5p via bioinformatics and luciferase reporter assays. miR-4728-5p was further demonstrated to increase HER2 expression and promote cell proliferation and migration by directly inhibiting EBP1 in breast cancer. Taken together, the HER2-intronic miR-4728-5p/EBP1/HER2 feedback loop plays an important role in promoting breast cancer cell proliferation and migration. Our study provides novel insights for targeted therapies of breast cancer., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2021
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13. Consensus of Chinese experts on protection of skin and mucous membrane barrier for health-care workers fighting against coronavirus disease 2019.
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Yan Y, Chen H, Chen L, Cheng B, Diao P, Dong L, Gao X, Gu H, He L, Ji C, Jin H, Lai W, Lei T, Li L, Li L, Li R, Liu D, Liu W, Lu Q, Shi Y, Song J, Tao J, Wang B, Wang G, Wu Y, Xiang L, Xie J, Xu J, Yao Z, Zhang F, Zhang J, Zhong S, Li H, and Li H
- Subjects
- COVID-19, China, Consensus, Emollients administration & dosage, Gloves, Protective, Hand Disinfection methods, Humans, Masks, Pandemics, Personal Protective Equipment, Coronavirus Infections therapy, Health Personnel, Mucous Membrane pathology, Occupational Diseases prevention & control, Pneumonia, Viral therapy, Skin pathology
- Abstract
Health professions preventing and controlling Coronavirus Disease 2019 are prone to skin and mucous membrane injury, which may cause acute and chronic dermatitis, secondary infection and aggravation of underlying skin diseases. This is a consensus of Chinese experts on protective measures and advice on hand-cleaning- and medical-glove-related hand protection, mask- and goggles-related face protection, UV-related protection, eye protection, nasal and oral mucosa protection, outer ear, and hair protection. It is necessary to strictly follow standards of wearing protective equipment and specification of sterilizing and cleaning. Insufficient and excessive protection will have adverse effects on the skin and mucous membrane barrier. At the same time, using moisturizing products is highly recommended to achieve better protection., (© 2020 Wiley Periodicals, Inc.)
- Published
- 2020
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14. Integrating single Ni sites into biomimetic networks of covalent organic frameworks for selective photoreduction of CO 2 .
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Chen X, Dang Q, Sa R, Li L, Li L, Bi J, Zhang Z, Long J, Yu Y, and Zou Z
- Abstract
Selective photoreduction of CO
2 into a given product is a great challenge but desirable. Inspired by natural photosynthesis occurring in hierarchical networks over non-precious molecular metal catalysts, we demonstrate an integration of single Ni sites into the hexagonal pores of polyimide covalent organic frameworks (PI-COFs) for selective photoreduction of CO2 to CO. The single Ni sites in the hexagonal pores of the COFs serve as active sites for CO2 activation and conversion, while the PI-COFs not only act as a photosensitizer to generate charge carriers but also exert a promoting effect on the selectivity. The optimized PI-COF with a triazine ring exhibits excellent activity and selectivity. A possible intra- and inter-molecular charge-transfer mechanism was proposed, in which the photogenerated electrons in PI-COFs are efficiently separated from the central ring to the diimide linkage, and then transferred to the single Ni active sites, as evidenced by theoretical calculations., (This journal is © The Royal Society of Chemistry 2020.)- Published
- 2020
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15. Validation of an algorithm to evaluate the appropriateness of outpatient antibiotic prescribing using big data of Chinese diagnosis text.
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Zhao H, Bian J, Wei L, Li L, Ying Y, Zhang Z, Yao X, Zhuo L, Cao B, Zhang M, and Zhan S
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- Adolescent, Adult, Aged, Big Data, Child, Child, Preschool, China, Female, Humans, Infant, Infant, Newborn, Male, Middle Aged, Young Adult, Algorithms, Anti-Bacterial Agents therapeutic use, Inappropriate Prescribing, Outpatients
- Abstract
Objective: We aimed to evaluate the validity of an algorithm to classify diagnoses according to the appropriateness of outpatient antibiotic use in the context of Chinese free text., Setting and Participants: A random sample of 10 000 outpatient visits was selected between January and April 2018 from a national database for monitoring rational use of drugs, which included data from 194 secondary and tertiary hospitals in China., Research Design: Diagnoses for outpatient visits were classified as tier 1 if associated with at least one condition that 'always' justified antibiotic use; as tier 2 if associated with at least one condition that only 'sometimes' justified antibiotic use but no conditions that 'always' justified antibiotic use; or as tier 3 if associated with only conditions that never justified antibiotic use, using a tier-fashion method and regular expression (RE)-based algorithm., Measures: Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of the classification algorithm, using classification made by chart review as the standard reference, were calculated., Results: The sensitivities of the algorithm for classifying tier 1, tier 2 and tier 3 diagnoses were 98.2% (95% CI 96.4% to 99.3%), 98.4% (95% CI 97.6% to 99.1%) and 100.0% (95% CI 100.0% to 100.0%), respectively. The specificities were 100.0% (95% CI 100.0% to 100.0%), 100.0% (95% CI 99.9% to 100.0%) and 98.6% (95% CI 97.9% to 99.1%), respectively. The PPVs for classifying tier 1, tier 2 and tier 3 diagnoses were 100.0% (95% CI 99.1% to 100.0%), 99.7% (95% CI 99.2% to 99.9%) and 99.7% (95% CI 99.6% to 99.8%), respectively. The NPVs were 99.9% (95% CI 99.8% to 100.0%), 99.8% (95% CI 99.7% to 99.9%) and 100.0% (95% CI 99.8% to 100.0%), respectively., Conclusions: The RE-based classification algorithm in the context of Chinese free text had sufficiently high validity for further evaluating the appropriateness of outpatient antibiotic prescribing., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)
- Published
- 2020
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16. One-Pot Fabrication of Pd Nanoparticles@Covalent-Organic-Framework-Derived Hollow Polyamine Spheres as a Synergistic Catalyst for Tandem Catalysis.
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Yang X, He Y, Li L, Shen J, Huang J, Li L, Zhuang Z, Bi J, and Yu Y
- Abstract
Facile fabrication of nanocatalysts consisting of metal nanoparticles (NPs) anchored on a functional support is highly desirable, yet remains challenging. Covalent organic frameworks (COFs) provide an emerging materials platform for structural control and functional design. Here, a facile one-pot in situ reduction approach is demonstrated for the encapsulation of small Pd NPs into the shell of COF-derived hollow polyamine spheres (Pd@H-PPA). In the one-pot synthetic process, the nucleation and growth of Pd NPs in the cavities of the porous shell take place simultaneously with the reduction of imine linkages to secondary amine groups. Pd@H-PPA shows a significantly enhanced catalytic activity and recyclability in the tandem dehydrogenation of ammonia borane and selective hydrogenation of nitroarenes through an adsorption-activation-reaction mechanism. The strong interactions of the secondary amine linkage with borane and nitroarene molecules afford a positive synergy to promote the catalytic reaction. Moreover, the hierarchical structure of Pd@H-PPA allows the accessibility of active Pd NPs to reactants., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)
- Published
- 2020
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17. Analysis of Air Purification Methods in Operating Rooms of Chinese Hospitals.
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Zhang B, Li L, Yao X, Gong Y, Zhang Y, Yang H, Li W, Lin L, Yang Y, Zhang H, and Jia H
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- Air Conditioning, Air Microbiology, Bacteria isolation & purification, China, Disease Transmission, Infectious prevention & control, Disinfection instrumentation, Humans, Ultraviolet Rays, Air analysis, Disinfection methods, Hospitals, Operating Rooms
- Abstract
This research demonstrates the current use of air purification methods in the operating rooms (ORs) in China. 154 hospitals from 6 provinces were included in this survey to reflect the air purification methods of ORs in 2017. Air cleaning technology (ACT) is used in 124 (80.52%) hospitals. We find that the rates of using grade I, III, or IV clean operating room (COR) in tertiary hospitals are all higher than in lower level hospitals; the rate of using ACT in the ORs is higher, too. In addition, general hospitals have higher rate in using ACT in the ORs than specialized hospitals. The highest rate of using ACT in the ORs is in the eastern region of China. The number of hospitals using ACT, ultraviolet light disinfection, and air sterilizers (such as circulating air UV sterilizer) increased yearly. All grades of CORs can be maintained as required by more than 90% hospitals except grade II COR. In this research, we found air purification methods, especially the ACT, are widely used in hospitals' ORs. However, finding the way to select and use different air purification methods correctly is an urgent problem to be solved next., Competing Interests: The authors declare that they have no conflicts of interest regarding the publication of this paper., (Copyright © 2020 Bingli Zhang et al.)
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- 2020
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18. A Covalent Triazine-Based Framework Consisting of Donor-Acceptor Dyads for Visible-Light-Driven Photocatalytic CO 2 Reduction.
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Zhong H, Hong Z, Yang C, Li L, Xu Y, Wang X, and Wang R
- Abstract
Photocatalytic conversion of CO
2 into value-added chemical fuels is a promising approach to address the depletion of fossil energy and environment-related concerns. Tailor-making the electronic properties and band structures of photocatalysts is pivotal to improve their efficiency and selectivity in photocatalytic CO2 reduction. Herein, a covalent triazine-based framework was developed containing electron-donor triphenylamine and electron-acceptor triazine components (DA-CTF). The engineered π-conjugated electron donor-acceptor dyads in DA-CTF not only optimized the optical bandgap but also contributed to visible-light harvesting and migration of photoexcited charge carriers. The activity of photocatalytic CO2 reduction under visible light was significantly improved compared with that of traditional g-C3 N4 and reported covalent triazine-based frameworks. This study provides molecular-level insights into the mechanism of photocatalytic CO2 reduction., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)- Published
- 2019
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19. A Cobalt-Modified Covalent Triazine-Based Framework as an Efficient Cocatalyst for Visible-Light-Driven Photocatalytic CO 2 Reduction.
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Bi J, Xu B, Sun L, Huang H, Fang S, Li L, and Wu L
- Abstract
Photocatalytic CO
2 reduction into carbonaceous feedstock chemicals is a promising renewable energy technology to convert solar energy and greenhouse gases into chemical fuels. Here, a covalent triazine-based framework (CTF) is demonstrated as an efficient cocatalyst to reduce CO2 under visible-light irradiation. The nitrogen-rich triazine moieties in CTF contribute to CO2 adsorption, while the periodical pore structure of CTF favors the accommodation of CO2 and electron mediator. Immobilization of cobalt species onto CTF promotes the photocatalytic activity with a 44-fold enhancement over pristine CTF and the optimal CO production rate of the obtained Co/CTFs was up to 50 μmol g-1 h-1 . The results of solid-state UV-vis diffuse reflectance spectra (UV-vis DRS), CO2 adsorption and electrochemical impedance spectroscopy (EIS) illustrated that the increased activity was ascribed to the enhanced CO2 capture capacity, improved absorption of visible-light and facilitated the transfer of charge from CTF to CO2 molecules. The CTF not only serves as a substrate for active Co species, but also bridges the photosensitizer with cobalt catalytic sites for the efficient transfer of photoexcited electrons. This work highlights the capability and ease of fabricating covalent organic framework-based photocatalytic systems that are potentially useful for energy-conversion applications., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)- Published
- 2019
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20. Constructing a novel family of halogen-doped covalent triazine-based frameworks as efficient metal-free photocatalysts for hydrogen production.
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Cheng Z, Zheng K, Lin G, Fang S, Li L, Bi J, Shen J, and Wu L
- Abstract
Halogens, as typical non-metal dopants, have attracted intensive interests for developing highly active photocatalysts. However, the essential factors and underlying mechanism of halogen modification are still unclear. Herein, we systematically report the development of halogen (F, Cl and Br)-doped covalent triazine-based frameworks (CTFs) via a facile thermal treatment of CTFs and an excess of ammonium halide. The introduction of halogen atoms endowed CTFs with multiple superior effects such as improved optical absorption, promoted charge migration, narrowed band gaps and tuned band positions. The newly developed halogen-doped CTFs showed remarkable photocatalytic activities for H
2 evolution under visible-light irradiation. Notably, the most enhanced photocatalytic performance was obtained with Cl-doped CTFs, which exhibited 7.1- and 2.4-fold enhancements compared to un-doped CTFs and Cl-doped g-C3 N4 , respectively. The electronegativity and atomic radius of the halogen atoms affected the modification of the optical and electronic properties, leading to different photocatalytic performances of F-, Cl- and Br-doped CTFs. The conclusions presented in this work will provide some new insights into the understanding of the doping effect for the improvement of the photocatalytic activity of halogen-doped CTF photocatalysts., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)- Published
- 2019
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21. A Covalent Organic Framework Bearing Single Ni Sites as a Synergistic Photocatalyst for Selective Photoreduction of CO 2 to CO.
- Author
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Zhong W, Sa R, Li L, He Y, Li L, Bi J, Zhuang Z, Yu Y, and Zou Z
- Abstract
Photocatalytic reduction of CO
2 into energy-rich carbon compounds has attracted increasing attention. However, it is still a challenge to selectively and effectively convert CO2 to a desirable reaction product. Herein, we report a design of a synergistic photocatalyst for selective reduction of CO2 to CO by using a covalent organic framework bearing single Ni sites (Ni-TpBpy), in which electrons transfer from photosensitizer to Ni sites for CO production by the activated CO2 reduction under visible-light irradiation. Ni-TpBpy exhibits an excellent activity, giving a 4057 μmol g-1 of CO in a 5 h reaction with a 96% selectivity over H2 evolution. More importantly, when the CO2 partial pressure was reduced to 0.1 atm, 76% selectivity for CO production is still obtained. Theoretical calculations and experimental results suggest that the promising catalytic activity and selectivity are ascribed to synergistic effects of single Ni catalytic sites and TpBpy, in which the TpBpy not only serves as a host for CO2 molecules and Ni catalytic sites but also facilitates the activation of CO2 and inhibits the competitive H2 evolution.- Published
- 2019
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22. Experimental and theoretical study for CO 2 activation and chemical fixation with epoxides.
- Author
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Gao J, Li L, Cui C, Ziaee MA, Gong Y, Sa R, and Zhong H
- Abstract
The synthesis of five-membered cyclic carbonates via catalytic cycloaddition reaction of CO
2 with epoxides is considered to be an effective technology for alleviation of the energy crisis and global warming. Various commercial organic bases and ionic salts were used as catalysts, while the relationship of catalytic activity and compound structure has been seldom explored. Herein, a facilely obtained binary catalytic system based on triethylamine/NBu4 Br was developed for CO2 activation and chemical fixation. The highly efficient catalytic system showed outstanding conversion and above 99% selectivity under metal-free mild reaction conditions (100 °C, 1 atm) in one hour. The detailed process of CO2 activation and chemical fixation was investigated at the molecular level by a series of experiments and theoretical calculation, which provided a mode for the design and synthesis of a highly efficient catalytic system for conversion of CO2 under mild conditions., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)- Published
- 2019
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23. Impact of Healthcare-Associated Infections on Length of Stay: A Study in 68 Hospitals in China.
- Author
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Jia H, Li L, Li W, Hou T, Ma H, Yang Y, Wu A, Liu Y, Wen J, Yang H, Luo X, Xing Y, Zhang W, Wu Y, Ding L, Liu W, Lin L, Li Y, and Chen M
- Subjects
- Adolescent, Adult, Aged, Aged, 80 and over, Bacterial Infections microbiology, Bacterial Infections pathology, Child, Child, Preschool, China epidemiology, Cross Infection microbiology, Cross Infection pathology, Female, Hospitalization, Hospitals, Humans, Infant, Infant, Newborn, Intensive Care Units, Male, Middle Aged, Young Adult, Bacteria pathogenicity, Bacterial Infections epidemiology, Cross Infection epidemiology, Length of Stay
- Abstract
Healthcare-associated infections (HAIs) not only bring additional medical cost to the patients but also prolong the length of stay (LOS). 2119 HAI case-patients and 2119 matched control-patients were identified in 68 hospitals in 14 primary sampling provinces of 7 major regions of China. The HAI caused an increase in stay of 10.4 days. The LOS due to HAI increased from 9.7 to 10.9 days in different levels of hospitals. There was no statistically significant difference in the increased LOS between different hospital levels. The increased LOS due to HAI in different regions was 8.2 to 12.6 days. Comparing between regions, we found that the increased LOS due to HAI in South China is longer than other regions except the Northeast. The gastrointestinal infection (GI) caused the shortest extra LOS of 6.7 days while the BSI caused the longest extra LOS of 12.8 days. The increased LOS for GI was significantly shorter than that of other sites. Among 2119 case-patients, the non-multidrug-resistant pathogens were detected in 365 cases. The average increased LOS due to these bacterial infections was 12.2 days. E. coli infection caused significantly shorter LOS. The studied MDROs, namely, MRSA, VRE, ESBLs- E. coli , ESBLs-KP, CR- E. coli , CR-KP, CR-AB, and CR-PA were detected in 381 cases (18.0%). The average increased LOS due to these MDRO infections was 14 days. Comparing between different MDRO infections, we found that the increased LOS due to HAI caused by CR-PA (26.5 days) is longer than other MDRO infections (shorter than 19.8 days).
- Published
- 2019
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24. [Genetic analysis of a pedigree affected with distal hereditary motor neuronopathy V].
- Author
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Li T, Lyu X, Xiao H, Li L, Guo Q, Wang H, Zhang B, Zhang C, Wang X, and Liao S
- Subjects
- Female, GTP-Binding Protein gamma Subunits, Humans, Mutation, Pedigree, Pregnancy, Muscular Atrophy, Spinal
- Abstract
Objective: To carry out genetic testing for a family affected with distal hereditary motor neuronopathy V (dHMN V)., Methods: Potential mutations of the GARS and BSCL2 genes were analyzed with PCR and Sanger sequencing. Suspected mutation was verified among unaffected members of the family and 100 healthy controls. Prenatal diagnosis was provided based on the above results., Results: Sequencing analysis has identified a heterozygous c.269C>T (p.S90L) mutation in the BSCL2 gene, which resulted in replacement of Serine (TCG) to Leucine (TTG). The same mutation was found in all other 3 patients from the pedigree but not among unaffected members or the 100 healthy controls. By prenatal diagnosis, the fetus did not carry the above mutation., Conclusion: Pathogenic mutation of BSCL2 gene probably underlies the dHMN V in this pedigree, which enabled prenatal diagnosis for the proband.
- Published
- 2019
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25. The Attributable Direct Medical Cost of Healthcare Associated Infection Caused by Multidrug Resistance Organisms in 68 Hospitals of China.
- Author
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Jia H, Li W, Hou T, Ma H, Yang Y, Wu A, Liu Y, Wen J, Yang H, Luo X, Xing Y, Zhang W, Wu Y, Ding L, Liu W, Lin L, Li Y, Chen M, and Li L
- Subjects
- Aged, Bacteria classification, China epidemiology, Costs and Cost Analysis, Female, Humans, Male, Bacteria isolation & purification, Bacterial Infections economics, Bacterial Infections epidemiology, Bacterial Infections microbiology, Bacterial Infections therapy, Cross Infection economics, Cross Infection epidemiology, Cross Infection microbiology, Cross Infection therapy, Drug Resistance, Multiple, Bacterial, Hospitalization, Hospitals
- Abstract
Healthcare associated infection (HAI) is known to increase the economic burden of patients while the medical cost due to MDRO HAI is even higher. Three hundred eighty-one multidrug resistance organisms (MDROs) healthcare associated infection (HAI) case-patients and three hundred eighty-one matched control-patients were identified between January and December in 2015. The average total hospitalization medical cost of the case group was $6127.65 and that of the control group was $2274.02. The difference between the case group and the control group was statistically significant (t = 21.07; P < 0.01). The attributable cost of MDRO HAI was $3853.63. The direct medical costs due to different MDRO infections were different. The increased medical costs of CR-AB, CR-KP, and CR-PA were significantly higher than that of MRSA, MRSE, ESBL E. coli, and ESBL Kp (P < 0. 05). Among the subitem expenses, the drug cost increased the most (the average cost was $1457.72), followed by the treatment fee and test fee; the differences were statistically significant (P < 0.01).
- Published
- 2019
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26. PTP1B markedly promotes breast cancer progression and is regulated by miR-193a-3p.
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Yu M, Liu Z, Liu Y, Zhou X, Sun F, Liu Y, Li L, Hua S, Zhao Y, Gao H, Zhu Z, Na M, Zhang Q, Yang R, Zhang J, Yao Y, and Chen X
- Subjects
- Animals, Apoptosis, Breast Neoplasms genetics, Breast Neoplasms metabolism, Cell Proliferation, Disease Progression, Female, Humans, Mice, Mice, Nude, Prognosis, Protein Tyrosine Phosphatase, Non-Receptor Type 1 genetics, Tumor Cells, Cultured, Xenograft Model Antitumor Assays, Breast Neoplasms pathology, Gene Expression Regulation, Neoplastic, MicroRNAs genetics, Protein Tyrosine Phosphatase, Non-Receptor Type 1 metabolism
- Abstract
The protein tyrosine phosphatase PTP1B, which is encoded by PTPN1, is a ubiquitously expressed nonreceptor protein tyrosine phosphatase. PTP1B has long been known to negatively regulate insulin and leptin receptor signalling. Recently, it was reported to be aberrantly expressed in cancer cells and to function as an important oncogene. In this study, we found that PTP1B protein levels are dramatically increased in breast cancer (BC) tissues and that PTP1B promotes the proliferation, and suppresses the apoptosis, of both HER2-positive and triple-negative BC cell lines. Bioinformatics analysis identified that the miRNA, miR-193a-3p, might potentially target PTP1B. We demonstrate that miR-193a-3p regulates PTP1B in BC cells and that it regulates the proliferation and apoptosis of BC cells by targeting PTP1B, both in vitro and in vivo. In conclusion, this study confirms that PTP1B acts as an oncogene in BC and demonstrates that miR-193a-3p can serve as a tumour suppressor gene in BC by targeting PTP1B., (© 2018 Federation of European Biochemical Societies.)
- Published
- 2019
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27. Well-Defined Metal Nanoparticles@Covalent Organic Framework Yolk-Shell Nanocages by ZIF-8 Template as Catalytic Nanoreactors.
- Author
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Cui K, Zhong W, Li L, Zhuang Z, Li L, Bi J, and Yu Y
- Abstract
Yolk-shell nanoreactors have received considerable interest for use in catalysis. However, the controlled synthesis of continuous crystalline shells without imperfections or cracks remains challenging. Here, a strategy for the synthesis of yolk-shell metal nanoparticles@covalent organic framework (MNPs@COF) nanoreactors by using MNPs@ZIF-8 core-shell nanostructures as a self-template is designed and developed. The COF shell is formed through an amorphous-to-crystalline transformation process of a polyimine shell in a mildly acidic solution, while the ZIF-8 is etched in situ, generating a void space between the MNPs core and the COF shell. With the protection of the COF shell, multiple ligand-free MNPs are confined inside of the hollow nanocages. Importantly, the synthetic strategy can be generalized to engineer the functions and properties of the designed yolk-shell nanocages by varying the structure of the COF shell and/or the composition of the core MNPs. Representative Pd@H-TpPa yolk-shell nanocages with active Pd NP cores and permeable TpPa shells exhibit high catalytic activity and stability in the reduction of 4-nitrophenol by NaBH
4 at room temperature., (© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)- Published
- 2019
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28. Efficient Visible-Light-Driven Photocatalytic Hydrogen Evolution on Phosphorus-Doped Covalent Triazine-Based Frameworks.
- Author
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Cheng Z, Fang W, Zhao T, Fang S, Bi J, Liang S, Li L, Yu Y, and Wu L
- Abstract
Seeking efficient visible-light-driven photocatalysts for water splitting to produce H
2 has attracted much attention. Chemical doping is an effective strategy to enhance photocatalytic performance. Herein, we reported phosphorus-doped covalent triazine-based frameworks (CTFs) for photocatalytic H2 evolution. Phosphorus-doped CTFs were fabricated by a facile thermal treatment using easily available red phosphorus as the external phosphorus species. The introduction of phosphorus atoms into the frameworks modified the optical and electronic property of CTFs, thus promoting the generation, separation, and migration of photoinduced electron-hole pairs. Consequently, the photocatalytic H2 -production efficiency of phosphorus-doped CTFs was greatly improved, which was 4.5, 3.9, and 1.8 times as high as that of undoped CTFs and phosphorus-doped g-C3 N4 calcined from melamine and urea, respectively.- Published
- 2018
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29. A covalent organic framework bearing thioether pendant arms for selective detection and recovery of Au from ultra-low concentration aqueous solution.
- Author
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Zhou Z, Zhong W, Cui K, Zhuang Z, Li L, Li L, Bi J, and Yu Y
- Abstract
A fluorescent covalent organic framework (COF), featuring precise distribution of thioether pendant arms inside the cavity, was designed. The thioether-functionalized COF exhibits selective sensing and capture of Au ions at ultra-trace levels in water with high sensitivity, selectivity and adsorption capacity, which makes it an excellent candidate for selective detection and recovery of Au.
- Published
- 2018
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30. Rapid water disinfection over a Ag/AgBr/covalent triazine-based framework composite under visible light.
- Author
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Li L, Li X, Cheng Z, Bi J, Liang S, Zhang Z, Yu Y, and Wu L
- Abstract
Development of visible-light-induced and rapid water disinfection is of significant importance. Covalent triazine-based frameworks (CTFs) with pre-designable structures and favorable semiconductive behaviors hold great promise for photocatalytic water disinfection. Here, we report an Ag/AgBr/CTF composite with a layered structure, which serves as an efficient photocatalyst for rapid water disinfection. Water disinfection with >99.99% inactivation of Escherichia coli within 12 min was achieved by using a small amount of Ag/AgBr/CTF under visible light irradiation. The inactivation efficiency of Ag/AgBr/CTF was ∼10 times better than that of bare Ag/AgBr. Rapid water disinfection by the Ag/AgBr/CTF composite mainly results from the greatly improved generation of reactive oxygen species through the synergistic effects among the three components and the affinity of CTF to the cell wall of bacteria.
- Published
- 2018
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31. MoS 2 Quantum Dots-Modified Covalent Triazine-Based Frameworks for Enhanced Photocatalytic Hydrogen Evolution.
- Author
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Jiang Q, Sun L, Bi J, Liang S, Li L, Yu Y, and Wu L
- Abstract
MoS
2 quantum dots (QDs)-modified covalent triazine-based framework (MoS2 /CTF) composites are synthesized through an in situ photodeposition method. MoS2 QDs are well distributed and stabilized on the layers of CTFs by coordination of the frameworks to MoS2 . The QDs-sheet interactions between MoS2 and CTFs facilitate interfacial charge transfer and separation. As a consequence, the composites exhibit outstanding photocatalytic activity and stability for hydrogen evolution under visible light irradiation (λ≥420 nm), that exceed those over pristine CTFs and MoS2 -modified g-C3 N4 (MoS2 /g-C3 N4 ) composite, making them promising materials for solar energy conversion., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)- Published
- 2018
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32. Heteroatom-doped Carbon Spheres from Hierarchical Hollow Covalent Organic Framework Precursors for Metal-Free Catalysis.
- Author
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Li L, Li L, Cui C, Fan H, and Wang R
- Subjects
- Boron chemistry, Carbon-13 Magnetic Resonance Spectroscopy, Catalysis, Catalytic Domain, Metals chemistry, Microscopy, Electron, Scanning, Microscopy, Electron, Transmission, Powder Diffraction, Proton Magnetic Resonance Spectroscopy, Spectroscopy, Fourier Transform Infrared, Thermogravimetry, Carbon chemistry, Organic Chemicals chemistry
- Abstract
Covalent organic frameworks (COFs) with hollow structures hold great promise for developing new types of functional materials. Herein, we report a hollow spherical COF with a hierarchical shell, which serves as an effective precursor of B,N-codoped hierarchical hollow carbon spheres. Benefiting from the synergistic effects of hierarchical porosity, high surface area, and B,N-codoping, the as-synthesized carbon spheres show prospective utility as metal-free catalysts in nitroarene reduction. A mechanistic hypothesis is proposed based on theoretical and experimental studies. Boron atoms situated meta to pyridinic N atoms are identified to be the main catalytic active sites. The anti-aromaticity originating from the codoping of B and pyridinic N atoms, not charge distribution and deformation energy, is confirmed to play a pivotal role in the catalytic reaction., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)
- Published
- 2017
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33. Development and photocatalytic mechanism of monolayer Bi 2 MoO 6 nanosheets for the selective oxidation of benzylic alcohols.
- Author
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Jing K, Xiong J, Qin N, Song Y, Li L, Yu Y, Liang S, and Wu L
- Abstract
Monolayer Bi
2 MoO6 nanosheets have been successfully prepared for the first time via a bottom-top approach with surfactant assistance, and show 8 times higher activity than bulk Bi2 MoO6 for the selective oxidation of benzyl alcohol. Ultrafast charge separation and more acid-base active sites on the monolayer nanosheets are considered to be responsible for the robust photoactivity.- Published
- 2017
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34. Surveillance of Dialysis Events: one-year experience at 33 outpatient hemodialysis centers in China.
- Author
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Zhang H, Li L, Jia H, Liu Y, Wen J, Wu A, Lu Q, Hou T, Yang Y, Yang H, Li W, and Zong Z
- Subjects
- China epidemiology, Hospitalization, Humans, Incidence, Prospective Studies, Communicable Diseases epidemiology, Epidemiological Monitoring, Outpatients, Renal Dialysis adverse effects
- Abstract
A multicenter prospective surveillance on dialysis events was carried in 33 dialysis centers in China. Maintenance hemodialysis (HD) outpatients who were dialyzed on the first two days of each month during 2014 were monitored for dialysis events and other infections. During the one-year period, 52,680 patient-months were monitored. Fistula and tunneled or non-tunneled central line were used for 73.70%, 15.70% and 8.85% of vascular access, respectively. There were 773 dialysis events occurred in 671 patients including 589 IV antimicrobial starts, 74 positive blood cultures and 110 local access site infections (LASI). The incidence of dialysis events was 1.47 per 100 patient-months. Among the 74 cases with bloodstream infection (BSI), 38 were access-related BSI (ARB) and there were therefore 148 cases with vascular-related infection (VAI; 38 ARB and 110 LASI). There were 740 cases (1.40 per 100 patient-months) with infections other than BSI and LASI, most (79.19%) of which were respiratory tract infections. For those with dialysis events, there were 425 cases (425/671, 63.34%) admitted to hospital and 12 cases of death (12/671, 1.79%). In conclusion, the surveillance revealed a relatively low incidence of dialysis events and the surveillance may be tailored to target those using central lines in resource-limited settings.
- Published
- 2017
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35. Covalent Triazine-Based Frameworks as Visible Light Photocatalysts for the Splitting of Water.
- Author
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Bi J, Fang W, Li L, Wang J, Liang S, He Y, Liu M, and Wu L
- Subjects
- Catalysis, Electrochemical Techniques, Graphite chemistry, Hydrogen chemistry, Oxidation-Reduction, Oxygen chemistry, Photochemical Processes, Ultraviolet Rays, Triazines chemistry, Water chemistry
- Abstract
Covalent triazine-based frameworks (CTFs) with a graphene-like layered morphology have been controllably synthesized by the trifluoromethanesulfonic acid-catalyzed nitrile trimerization reactions at room temperature via selecting different monomers. Platinum nanoparticles are well dispersed in CTF-T1, which is ascribed to the synergistic effects of the coordination of triazine moieties and the nanoscale confinement effect of CTFs. CTF-T1 exhibits excellent photocatalytic activity and stability for H2 evolution in the presence of platinum under visible light irradiation (λ ≥ 420 nm). The activity and stability of CTF-T1 are comparable to those of g-C3 N4 . Importantly, as a result of the tailorable electronic and spatial structures of CTFs that can be achieved through the judicial selection of monomers, CTFs not only show great potential as organic semiconductor for photocatalysis but also may provide a molecular-level understanding of the inherent heterogeneous photocatalysis., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)
- Published
- 2015
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36. First multicenter study on multidrug resistant bacteria carriage in Chinese ICUs.
- Author
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Ma X, Wu Y, Li L, Xu Q, Hu B, Ni Y, Wu A, Sun S, Jarlier V, and Robert J
- Subjects
- Acinetobacter isolation & purification, Adult, Aged, Aged, 80 and over, Child, China epidemiology, Cross Infection microbiology, Enterobacteriaceae isolation & purification, Female, Gram-Negative Bacterial Infections microbiology, Humans, Male, Methicillin-Resistant Staphylococcus aureus isolation & purification, Middle Aged, Prevalence, Prospective Studies, Pseudomonas aeruginosa isolation & purification, Staphylococcal Infections microbiology, Young Adult, beta-Lactam Resistance, Drug Resistance, Multiple, Bacterial, Gram-Negative Bacterial Infections epidemiology, Intensive Care Units statistics & numerical data, Staphylococcal Infections epidemiology
- Abstract
Background: The importance of multidrug-resistant organisms (MDRO) in Chinese hospitals is not clearly delineated. Thus we sought to assess the prevalence of MDRO in Chinese intensive care units (ICUs)., Methods: Prospective study of inpatients admitted consecutively to eight ICUs in four Chinese cities in 2009-10. Admission and weekly screenings were performed by using selective media for methicillin resistant Staphylococcus aureus, extended-spectrum beta-lactamase-producing Enterobacteriaceae, Acinetobacter and Pseudomonas aeruginosa. For the two latters, resistance to ceftazidime defined MDRO. Backward logistic regression models were designed to assess factors independently associated with MDRO carriage on admission and MDRO acquisition within ICUs., Results: 686 patients were included, and the MDRO prevalence rate on admission was 30.5 % (32.7 % for ESBL-positive Enterobacteriaceae, 3.2 % for MRSA). Antibiotic treatment prior to ICU admission was independently associated with carriage on admission (OR: 1.4) in multivariate analysis. A total of 104 patients acquired ≥1 MDRO in ICU (overall attack rate: 23.7 %; 14.9 % for ESBL-positive Enterobacteriaceae, and 5.1 % for MRSA). The MDRO attack rate increased from 13.2 % in the first week to 82.1 % for ICU stay > 3 weeks. Duration of antibiotic exposure (OR: 1.16; 1.1-1.2) and prior antibiotic treatment before ICU (OR: 2.1; 1.1-3.3) were associated with MDRO acquisition in multivariate analysis. The MDRO prevalence rate on ICU discharge was 51.2 % and the global prevalence density rate 71 per 1000 hospital-days., Conclusion: More than one out of two patients was MDRO carrier on ICU discharge in Chinese hospitals. This is the result of the combination of a high MDRO prevalence rate on ICU admission and a high MDRO acquisition rate within ICU.
- Published
- 2015
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37. Solvent-Induced Facile Synthesis of Cubic-, Spherical-, and Honeycomb-Shape Palladium N-Heterocyclic Carbene Particles and Catalytic Applications in Cyanosilylation.
- Author
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Zhao H, Li X, Li L, and Wang R
- Abstract
The facile synthesis of palladium N-heterocyclic carbene (NHC) particles with spherical, cubic, and honeycomb morphologies is accomplished. The structures of cubic and honeycomb particles are defined as an unprecedented trinuclear palladium-NHC complex. An obvious effect of particle morphologies on catalytic activity and recyclability is observed in hetero-geneous cyanosilylation., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)
- Published
- 2015
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38. Spherical core-shell magnetic particles constructed by main-chain palladium N-heterocyclic carbenes.
- Author
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Zhao H, Li L, Wang J, and Wang R
- Abstract
The encapsulation of the functional species on magnetic core is a facile approach for the synthesis of core-shell magnetic materials, and surface encapsulating matrices play crucial roles in regulating their properties and applications. In this study, two core-shell palladium N-heterocyclic carbene (NHC) particles (Fe3O4@PNP1 and Fe3O4@PNP2) were prepared by a one-pot reaction of semi-rigid tripodal imidazolium salts and palladium acetate in the presence of magnetite nanoparticles. The magnetite nanoparticles are encapsulated inside the main-chain palladium, which act as cores. The conjugated effects of triphenyltriazine and triphenylbenzene in the imidazolium salts have important influence on their physical properties and catalytic performances. Fe3O4@PNP2 shows better recyclability than Fe3O4@PNP1. Unexpectedly, Pd(ii) is well maintained after six consecutive catalytic runs in Fe3O4@PNP2, and Pd(0) and Pd(ii) coexist in Fe3O4@PNP1 under the same conditions; moreover, the morphologies of these spherical core-shell particles show no significant variation after six consecutive catalytic runs.
- Published
- 2015
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39. Shape-controllable formation of poly-imidazolium salts for stable palladium N-heterocyclic carbene polymers.
- Author
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Zhao H, Li L, Wang Y, and Wang R
- Abstract
The imidazolium-based main-chain organic polymers are one of promising platforms in heterogeneous catalysis, the size and outer morphology of polymer particles are known to have important effects on their physical properties and catalytic applications, but main-chain ionic polymers usually generate amorphous or spherical particles. Herein, we presented a versatile and facile synthetic route for size- and shape-controllable synthesis of main-chain poly-imidazolium particles. The wire-shaped, spherical and ribbon-shaped morphologies of poly-imidazolium particles were readily synthesized through quaternization of bis-(imidazol-1-yl)methane and 2,4,6-tris(4-(bromomethyl)phenyl)-1,3,5-triazine, and the modification of their size and morphology were realized through adjusting solvent polarity, solubility, concentration and temperatures. The direct complexation of the particles with Pd(OAc)2 produced ionic polymers containing palladium N-heterocyclic carbene units (NHCs) with intactness of original morphologies. The particle morphologies have a significant effect on catalytic performances. Wire-shaped palladium-NHC polymer shows excellent catalytic activity and recyclabilty in heterogeneous Suzuki-Miyaura cross-coupling reaction.
- Published
- 2014
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40. Facile fabrication of ultrafine palladium nanoparticles with size- and location-control in click-based porous organic polymers.
- Author
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Li L, Zhao H, Wang J, and Wang R
- Abstract
Two click-based porous organic polymers (CPP-1 and CPP-2) are readily synthesized through a click reaction. Using CPP-1 and CPP-2 as supports, palladium nanoparticles (NPs) with uniform and dual distributions were prepared through H2 and NaBH4 reduction routes, respectively. Ultrafine palladium NPs are effectively immobilized in the interior cavities of polymers. The coordination of 1,2,3-triazolyl to palladium and the confinement effect of polymers on palladium NPs are verified by solid-state (13)C NMR and IR spectra, XPS analyses, EDX mapping, and computational calculation. The steric and electronic properties of polymers have a considerable influence on the interaction between polymers and palladium NPs, as well as the catalytic performances of NPs. The ultrafine palladium NPs with uniform distribution exhibit superior stability and recyclability over palladium NPs with dual distributions and palladium on charcoal in the hydrogenation of nitroarenes, and no obvious agglomeration and loss of catalytic activity were observed after recycling several times. The excellent performances mainly result from synergetic effects between palladium NPs and polymers.
- Published
- 2014
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41. Urea-based porous organic frameworks: effective supports for catalysis in neat water.
- Author
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Li L, Chen Z, Zhong H, and Wang R
- Abstract
Two urea-based porous organic frameworks, UOF-1 and UOF-2, were synthesized through a urea-forming condensation of 1,3,5-benzenetriisocyanate with 1,4-diaminobenzene and benzidine, respectively. UOF-1 and UOF-2 possess good hydrophilic properties and high scavenging ability for palladium. Their palladium polymers, PdII/UOF-1 and PdII/UOF-2, exhibit high catalytic activity and selectivity for Suzuki–Miyaura cross-coupling reactions and selective reduction of nitroarenes in water. The catalytic reactions can be efficiently performed at room temperature. Palladium nanoparticles with narrow size distribution were formed after the catalytic reaction and were well dispersed in UOF-1 and UOF-2. XPS analysis confirmed the coordination of the urea oxygen atom with palladium. SEM and TEM images showed that the original network morphology of UOF-1 and UOF-2 was maintained after palladium loading and catalytic reactions.
- Published
- 2014
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42. The copper-free Sonogashira cross-coupling reaction promoted by palladium complexes of nitrogen-containing chelating ligands in neat water at room temperature.
- Author
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Zhong H, Wang J, Li L, and Wang R
- Abstract
The commercially available 2,2'-dipyridylamine was used as a supporting ligand in the palladium-catalyzed Sonogashira cross-coupling reaction. The reactions between aryl iodides and terminal alkynes with different steric hindrance can be efficiently performed in the absence of copper in neat water at room temperature. The superior catalytic performance of the catalytic system was attributed to water solubility of the palladium 2,2'-dipyridylamine complex. Palladium nanoparticles with small size and narrow size distribution were formed after the cross-coupling reaction.
- Published
- 2014
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43. Water-Soluble Ionic Palladium Complexes: Effect of Pendant Ionic Groups on Palladium Nanoparticles and Suzuki-Miyaura Reaction in Neat Water.
- Author
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Li L, Wu T, Wang J, and Wang R
- Abstract
Three ionic nitrogen-containing chelating ligands (L1-L3) are synthesized readily through alkylation and quaternization of 2,2'-dipyridylamine. The charge distributions and natural bond orbital analyses of their cations are implemented by using density functional theory calculations. The catalytic performances of their water-soluble palladium complexes are evaluated preliminarily by using the Suzuki-Miyaura cross-coupling reaction, and high catalytic activities of aryl bromides and chlorides are achieved in neat water. The mercury drop test, poison experiments, and TEM analysis are used to demonstrate the formation of palladium nanoparticles (NPs) after the catalytic reaction. The effects of pendant ionic groups in L1-L3 on the catalytic activities and structures of the palladium NPs are disclosed. These NPs are stable in water for several weeks; they are stabilized by synergetic interactions between the chelating coordination of the 2,2'-dipyridylamino group to the surface of the palladium NPs and the electrostatic repulsion of the ionic groups in L1-L3., (Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)
- Published
- 2014
- Full Text
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44. Synthesis and Crystal Structures of Coordination Complexes Containing Cu 2 I 2 Units and Their Application in Luminescence and Catalysis.
- Author
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Zhao H, Li X, Wang J, Li L, and Wang R
- Abstract
The reaction of bis- or tris-chelating nitrogen-containing ligands (L1-L5) with CuI gave rise to five coordination complexes consisting of Cu
2 I2 dimeric units. L1 in complex 1 adopts a cis conformation and links Cu2 I2 into a dinuclear structure. L2 and L3 in complexes 2 and 3 exhibit a trans conformation, and the alternative linkage of L2 or L3 and Cu2 I2 results in the formation of a 1D chain. In complex 4, two pyrazolyl-pyridine units of L4 at the same side of the central phenyl ring are connected to Cu2 I2 forming a tetranuclear macrocycle, and the third pyrazolyl-pyridine unit at the other side of the central phenyl ring further links the macrocycle into a 1D chain. L5 bridges Cu2 I2 in a cis conformation forming a tetranuclear complex, which is very different from 1 owing to the difference of the electronic property between pyrazolyl and triazolyl rings. The coordination nitrogen atoms in two pairs of ortho-positioned nitrogen-containing chelating rings in L1 and L5 are directed toward opposite and the same directions, respectively. Complexes 1-4 containing pyrazolyl-pyridine units showed luminescence whereas no clear emission was observed in complex 5 containing triazolyl-pyridine units, despite the fact that they were investigated under the same conditions. The application of complexes 1-5 in the copper(I)-catalyzed Ullmann cross-coupling reaction and azide-alkyne cycloaddition reaction was preliminarily evaluated., (Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)- Published
- 2013
- Full Text
- View/download PDF
45. Click ionic liquids: a family of promising tunable solvents and application in Suzuki-Miyaura cross-coupling.
- Author
-
Li L, Wang J, Wu T, and Wang R
- Abstract
A series of click ionic salts 4 a-4 n was prepared through click reaction of organic azides with alkyne-functionalized imidazolium or 2-methylimidazolium salts, followed by metathesis with lithium bis(trifluoromethanesulfonyl)amide or potassium hexafluorophosphate. All salts were characterized by IR, NMR, TGA, and DSC, and most of them can be classified as ionic liquids. Their steric and electronic properties can be easily tuned and modified through variation of the aromatic or aliphatic substituents at the imidazolium and/or triazolyl rings. The effect of anions and substituents at the two rings on the physicochemical properties was investigated. The charge and orbital distributions based on the optimized structures of cations in the salts were calculated. Reaction of 4 a with PdCl(2) produced mononuclear click complex 4 a-Pd, the structure of which was confirmed by single-crystal X-ray diffraction analysis. Suzuki-Miyaura cross-coupling shows good catalytic stability and high recyclability in the presence of PdCl(2) in 4 a. TEM and XPS analyses show formation of palladium nanoparticles after the reaction. The palladium NPs in 4 a are immobilized by the synergetic effect of coordination and electrostatic interactions with 1,2,3-triazolyl and imidazolium, respectively., (Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)
- Published
- 2012
- Full Text
- View/download PDF
46. SARS infection among health care workers in Beijing, China.
- Author
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Li L, Cheng S, and Gu J
- Subjects
- China epidemiology, Emergency Service, Hospital, Hospital Bed Capacity, 500 and over, Hospitals, General, Humans, Infection Control, Infectious Disease Transmission, Patient-to-Professional prevention & control, Occupational Diseases prevention & control, Severe acute respiratory syndrome-related coronavirus isolation & purification, Severe Acute Respiratory Syndrome prevention & control, Health Personnel statistics & numerical data, Infectious Disease Transmission, Patient-to-Professional statistics & numerical data, Occupational Diseases epidemiology, Severe Acute Respiratory Syndrome epidemiology, Severe Acute Respiratory Syndrome transmission
- Published
- 2003
- Full Text
- View/download PDF
47. [Investigation report on the SARS infection rate of the second medical team of Peking University First Hospital].
- Author
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Zhou G, Qi Y, and Li L
- Subjects
- China epidemiology, Female, Hospitals, University, Humans, Incidence, Male, Severe Acute Respiratory Syndrome prevention & control, Health Personnel, Occupational Diseases epidemiology, Severe Acute Respiratory Syndrome epidemiology
- Abstract
Severe Acute Respiratory Syndrome (SARS) is a newly emerged, highly contagious disease. Health care workers remain the majority of total infections. The second SARS Medical Team of Peking University First Hospital was founded on May 1, 2003, which consist of 95 health care workers. During the working days in SARS wards and following isolation period no SARS cases were diagnosed. This investigation is aimed to give a detailed report on infection control precaution taken by this medical team. It was concluded that reasonable and strict infection control precaution help to reduce infection rate among health care workers, and careful supervision helped to achieve the reduction.
- Published
- 2003
48. [Analysis of medical workers suffered from SARS].
- Author
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Li L, Cheng S, and Gu J
- Subjects
- Adult, Aged, China epidemiology, Female, Humans, Incidence, Male, Middle Aged, Retrospective Studies, Occupational Diseases epidemiology, Personnel, Hospital, Severe Acute Respiratory Syndrome epidemiology
- Abstract
Objectives: To investigate the prevalence of SARS infection in medical workers and the efficacy of isolation precautions in the hospital., Methods: A retrospective analysis was employed to study the prevalence of SARS infection in medical workers who contacted with SARS patients directly. The data were analyzed with EPI statistic soft ware., Results: From March 15th, 2003 to May 18th, 2003, 224 patients with clinical confirmed SARS and 72 patients with clinical suspected SARS were presented in our hospital. The principle and system of the isolation precautions were established and implemented in our hospital. Seven hundreds and twenty medical workers including doctors, nurses and nurse-assistants were involved in the medical care of patients with SARS. Eighteen out of the 720 (2.43%) medical workers were infected with SARS, most of them were from the department of emergency, and the majority of infected medical workers were nurse-assistants. After the isolation precautions in hospital were established, the spreading of SARS in medical stuffs declined dramatically. The medical workers infected with SARS were 7.20% of SARS patients presented or hospitalized in our hospital. The infection rate was significantly lower than that of the average rate in our country., Conclusion: The isolation precautions taken in our hospital was effective.
- Published
- 2003
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