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Here, we demonstrate the development and the synthetic applications of a novel class of diphosphine ligands (SPSiP) based on chiral spirosilabiindane diol (SPSiOL). Starting from SPSiOL, the biphosphine ligands could be readily prepared in three steps with high efficiency. This novel class of biphosphine ligands features rigid configuration, a large dihedral angle, a large P–M–P angle, and a long P–P distance, which might possess unique catalytic reactivities. The potentials of SPSiPs in asymmetric catalysis have also been preliminary disclosed by Rh-catalyzed asymmetric hydrogenation, Rh-catalyzed tandem hydrosilylation, and Pd-catalyzed asymmetric allylic alkylation.

The transcriptional capacities of target genes are strongly influenced by promoters, whereas few studies have focused on the development of robust, high-performance and cross-species promoters for wide application in different bacteria. In this work, four novel promoters (Pk.rtufB, Pk.r1, Pk.r2, and Pk.r3) were predicted from Ketogulonicigenium robustum and their inconsistency in the -10 and -35 region nucleotide sequences indicated they were different promoters. Their activities were evaluated by using green fluorescent protein (gfp) as a reporter in different species of bacteria, including K. vulgare SPU B805, Pseudomonas putida KT2440, Paracoccus denitrificans PD1222, Bacillus licheniformis and Raoultella ornithinolytica, due to their importance in metabolic engineering. Our results showed that the four promoters had different activities, with Pk.r1 showing the strongest activity in almost all of the experimental bacteria. By comparison with the commonly used promoters of E. coli (tufB, lac, lacUV5), K. vulgare (Psdh, Psndh) and P. putida KT2440 (JE111411), the four promoters showed significant differences due to only 12.62% nucleotide similarities, and relatively higher ability in regulating target gene expression. Further validation experiments confirmed their ability in initiating the target minCD cassette because of the shape changes under the promoter regulation. The overexpression of sorbose dehydrogenase and cytochrome c551 by Pk.r1 and Pk.r2 resulted in a 22.75% enhancement of 2-KGA yield, indicating their potential for practical application in metabolic engineering. This study demonstrates an example of applying bioinformatics to find new biological components for gene operation and provides four novel promoters with broad suitability, which enriches the usable range of promoters to realize accurate regulation in different genetic backgrounds.

Pyrethrins constitute a class of terpene derivatives with high insecticidal activity and are mainly synthesized in the capitula of the horticulturally important plant

In order to study the dissemination mechanism of knowledge, a SIRI dynamics model with the learning rate, the forgetting rate and the recalling rate is constructed in this paper. Stability of equilibria and global dynamics of the SIRI model are analyzed. Two thresholds that determine whether knowledge is disseminated are given. We describe the stability of the equilibria for the SIRI model in which there are an equilibrium and a line of equilibria. In particular, we find the dividing curve function which is used to partition invariant set in order to discuss the local stability, and obtain the equation of the wave peak value or wave trough value in the process of knowledge dissemination. Numerical simulations are provided to support the theoretical results. The complicated dynamics properties exhibit that the model is very sensitive to variation of parameters, which play an important role on controlling and administering the knowledge dissemination.

Pyrethrins constitute a class of terpene derivatives with high insecticidal activity and are mainly synthesized in the capitula of the horticulturally important plant, Tanacetum cinerariifolium. Treatment of T. cinerariifolium with methyl jasmonate (MeJA) in the field induces pyrethrin biosynthesis, but the mechanism linking MeJA with pyrethrin biosynthesis remains unclear. In this study, we explored the transcription factors involved in regulating MeJA-induced pyrethrin biosynthesis. A single spray application of MeJA to T. cinerariifolium leaves rapidly upregulated the expression of most known pyrethrin biosynthesis genes and subsequently increased the total pyrethrin content in the leaf. A continuous 2-week MeJA treatment resulted in enhanced pyrethrin content and increased trichome density. TcMYC2, a key gene in jasmonate signaling, was screened at the transcriptome after MeJA treatment. TcMYC2 positively regulated expression of the pyrethrin biosynthesis genes TcCHS, TcAOC, and TcGLIP by directly binding to E-box/G-box motifs in the promoters. The stable overexpression of TcMYC2 in T. cinerariifolium hairy roots significantly increased the expression of TcAOC and TcGLIP. Further transient overexpression and viral-induced gene-silencing experiments demonstrated that TcMYC2 positively promoted pyrethrin biosynthesis. Collectively, the results reveal a novel molecular mechanism for MeJA-induced pyrethrin biosynthesis in T. cinerariifolium involving TcMYC2.

Xiaoqinglong decoction (XQLD), a classic prescription of Traditional Chinese Medicine, has already been used clinically to cure acute lung injury (ALI), but its mechanism remains unclear. This subject aimed to explore the preventive role of XQLD in septic ALI rats besides its effects on angiotensin-converting enzyme (ACE)2 and its downstream factors. After, respectively, administrated with different concentrations of XQLD (6.25 g/kg/d, 12.5 g/kg/d, 25 g/kg/d) for 5 days and dexamethasone (DEX, 1 mg/kg) for 0.5 h, the rat models of ALI were established by intraperitoneal injection of lipopolysaccharide (LPS, 5 mg/kg) for 24 h. All rats were evaluated by lung function test, arterial blood gas analysis, morphological observation, lung wet/dry (W/D) ratio, and the lung injury score. The levels of malonaldehyde (MDA), superoxide dismutase (SOD), interleukin (IL)-1β, tumor necrosis factor (TNF)-α, and angiotensin (Ang) (1–7) in the lung were measured through biochemical and ELISA kits. The expressions of angiotensin-converting enzyme (ACE)2, mitochondrial assembly receptor (MasR), and nuclear factor (NF)-κB in lung tissue were detected by qRT-PCR and western blotting. Positive reaction cells of MasR were observed by immunohistochemistry. The results show that XQLD significantly ameliorated septic lung injury including edema and hemorrhage, as well as improved pulmonary function and arterial blood gas. Furthermore, XQLD markedly decreased the levels of IL-1β, TNF-α, MDA, and NF-κB while increased the levels of SOD, Ang (1–7), ACE2, and MasR in septic ALI rats. Pearson correlation showed that the expressions of ACE2 were inversely related to IL-1β, TNF-α, MDA, and NF-κB and positively correlated with SOD contents. Our data indicated that XQLD pretreatment alleviated inflammation and oxidative damage in septic ALI rats, which might be related to the up-regulation of ACE2-Ang (1–7)-MasR axis and inhibition of the NF-κB pathway.

Background Traditional CRISPR/Cas9 systems that rely on U6 or U3 snRNA promoters (RNA polymerase III-dependent promoters) can only achieve constitutive gene editing in plants, hampering the functional analysis of specifically expressed genes. Ribozyme-mediated CRISPR/Cas9 systems increase the types of promoters which can be used to transcribe sgRNA. Therefore, such systems allow specific gene editing; for example, transcription of the artificial gene Ribozyme-sgRNA-Ribozyme (RGR) is initiated by an RNA polymerase II-dependent promoter. Genetic transformation is indispensable for editing plant genes. In certain plant species, including pyrethrum, genetic transformation remains challenging to do, limiting the functional verification of novel CRISPR/Cas9 systems. Thus, this study’s aim was to develop a simple Agrobacterium rhizogenes-mediated hairy root transformation system to analyze the function of a ribozyme-mediated CRISPR/Cas9 system in pyrethrum. Results A hairy root transformation system for pyrethrum is described, with a mean transformation frequency of 7%. Transgenic hairy roots transformed with the pBI121 vector exhibited significantly increased beta-glucuronidase staining as a visual marker of transgene expression. Further, a ribozyme-based CRISPR/Cas9 vector was constructed to edit the TcEbFS gene, which catalyzes synthesis of the defense-related compound (E)-β-farnesene in pyrethrum. The vector was transferred into the hairy roots of pyrethrum and two stably transformed hairy root transgenic lines obtained. Editing of the TcEbFS gene in the hairy roots was evaluated by gene sequencing, demonstrating that both hairy root transgenic lines had DNA base loss at the editing target site. Gas chromatography–mass spectrometry showed that the (E)-β-farnesene content was significantly decreased in both hairy root transgenic lines compared with the empty vector control group. Altogether, these results show that RGR can be driven by the CaMV35S promoter to realize TcEbFS gene editing in pyrethrum hairy roots. Conclusion An A. rhizogenes-mediated hairy root transformation and ribozyme-mediated CRISPR/Cas9 gene editing system in pyrethrum was established, thereby facilitating gene editing in specific organs or at a particular developmental stage in future pyrethrum research.

Hydroxycamptothecin (SN38) is a natural plant extract isolated from Camptotheca acuminate. It has a broad spectrum of anticancer activity through inhibition of DNA topoisomerase I, which could affect DNA synthesis and lead to DNA damage. Thus, the action of SN38 against cancers could inevitably affect endogenous levels of ribonucleotide (RNs) and deoxyribonucleotide (dRNs) that play critical roles in many biological processes, especially in DNA synthesis and repair. However, the exact impact of SN38 on RNs and dRNs is yet to be fully elucidated. In this study, we evaluated the anticancer effect and associated mechanism of SN38 in human colorectal carcinoma HCT 116 cells. As a result, SN38 could decrease the cell viability and induce DNA damage in a concentration-dependent manner. Furthermore, cell cycle arrest and intracellular nucleotide metabolism were perturbed due to DNA damage response, of which ATP, UTP, dATP, and TTP may be the critical metabolites during the whole process. Combined with the expression of deoxyribonucleoside triphosphates synthesis enzymes, our results demonstrated that the alteration and imbalance of deoxyribonucleoside triphosphates caused by SN38 was mainly due to the de novo nucleotide synthesis at 24 h, and subsequently the salvage pathways at 48 h. The unique features of SN38 suggested that it might be recommended as an effective supplementary drug with an anticancer effect.

Remdesivir (RDV) has generated much anticipation for its moderate effect in treating severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. However, the unsatisfactory survival rates of hospitalized patients limit its application to the treatment of coronavirus disease 2019 (COVID-19). Therefore, improvement of antiviral efficacy of RDV is urgently needed. As a typical nucleotide analog, the activation of RDV to bioactive triphosphate will affect the biosynthesis of endogenous ribonucleotides (RNs) and deoxyribonucleotides (dRNs), which are essential to RNA and DNA replication in host cells. The imbalance of RN pools will inhibit virus replication as well. In order to investigate the effects of RDV on cellular nucleotide pools and on RNA transcription and DNA replication, cellular RNs and dRNs concentrations were measured by the liquid chromatography-mass spectrometry method, and the synthesis of RNA and DNA was monitored using click chemistry. The results showed that the IC50 values for BEAS-2B cells at exposure durations of 48 and 72 h were 25.3 ± 2.6 and 9.6 ± 0.7 μM, respectively. Ten (10) μM RDV caused BEAS-2B arrest at S-phase and significant suppression of RNA and DNA synthesis after treatment for 24 h. In addition, a general increase in the abundance of nucleotides and an increase of specific nucleotides more than 2 folds were observed. However, the variation of pyrimidine ribonucleotides was relatively slight or even absent, resulting in an obvious imbalance between purine and pyrimidine ribonucleotides. Interestingly, the very marked disequilibrium between cytidine triphosphate (CTP) and cytidine monophosphate might result from the inhibition of CTP synthase. Due to nucleotides which are also precursors for the synthesis of viral nucleic acids, the perturbation of nucleotide pools would block viral RNA replication. Considering the metabolic vulnerability of endogenous nucleotides, exacerbating the imbalance of nucleotide pools imparts great promise to enhance the efficacy of RDV, which possibly has special implications for treatment of COVID-19.

Scannerless time-of-flight three-dimensional imaging, the successor to raster scanning three-dimensional imaging, relies on large-scale detector arrays to obtain high pixel resolution; however, manufacturing limitations lead to a bottleneck in imaging resolution. Here, we report a methodology for laser imaging using code division multiple access, which involves three key steps. Optical encoding is carried out for a pulsed laser to generate space-time encoded beams for projection. Optical multiplexing subdivides the backscattered light signals and multiplexes them to a downscaled avalanche-photodiode array. Subpixel decoding decodes the digitized encoded full waveforms and decomposes the features of all subpixels. Accordingly, we design a prototype based on a 64-order encoder and a 4-element avalanche-photodiode array and conduct an outdoor experiment. We demonstrate that the system is capable of obtaining 256 pixels per frame in push-broom mode and reconstruct a three-dimensional image with centimetre-level lateral resolution and range precision at a distance of ∼112 m. Scannerless time of flight three-dimensional devices can produce high-quality images from the ground or in space and provide information on light detection and ranging. The authors design and demonstrate a downscaled subpixel 3D laser imaging device which uses pulse-encoded illumination to encode the pixels.

Background: Behçet’s disease (BD) is associated with an increased risk of cancer. Few reports have been published on the relationship between drug exposure and the risk of cancer in patients with BD. Herein, we explored the relationship between pharmacologic interventions for BD and the risk of cancer.Methods: we carried out a retrospective nested case-control study in a cohort of BD patients from attending our institution. Among 1,148 patients, 22 cancer patients were individually 1:2 matched to 44 cancer-free controls. The following biochemical indicators were evaluated: routine blood analysis, liver and kidney function tests, inflammatory indexes, blood gas analysis, blood electrolyte and previous pharmacologic interventions to manage BD including systemic glucocorticoids, methotrexate, cyclosporine-A, azathioprine, cyclophosphamide (CYC), and thalidomide, which are considered the primary medicines used for the management of BD.Results: Among the 22 BD patients with cancers, myelodysplastic syndrome (MDS) (22.72%) was the most common type. Furthermore, CYC administration was significantly higher in BD patients with cancer compared with the cancer-free matched control group. Further, we observed that complement 4 (C4) (odds ratio [OR] = 0.0001, 95% confidence interval [CI]: 0.001–0.065) and hemoglobin (Hb) (OR = 0.891, 95% CI: 0.795–0.998) levels were independent protective factors for predicting cancer risk in BD patients on multivariate analyses.Conclusion: Our study revealed that CYC was associated with a high risk of cancer in BD patients. Furthermore, C4 and Hb are independent protective factors for oncogenesis in BD patients. These findings may provide references and suggestions for clinicians to select appropriate treatments and for the early recognition of high-risk patients to reduce cancer incidence in BD patients.

Background. Cutaneous melanoma (CM) is one of the most life-threatening primary skin cancers and is prone to distant metastases. A widespread presence of posttranscriptional modification of RNA, 5-methylcytosine (m5C), has been observed in human cancers. However, the potential mechanism of the tumorigenesis and prognosis in CM by dysregulated m5C-related regulators is obscure. Methods. We use comprehensive bioinformatics analyses to explore the expression of m5C regulators in CM, the prognostic implications of the m5C regulators, the frequency of the copy number variant (CNV), and somatic mutations in m5C regulators. Additionally, the CM patients were divided into three clusters for better predicting clinical features and outcomes via consensus clustering of m5C regulators. Then, the risk score was established via Lasso Cox regression analysis. Next, the prognosis value and clinical characteristics of m5C-related signatures were further explored. Then, machine learning was used to recognize the outstanding m5C regulators to risk score. Finally, the expression level and clinical value of USUN6 were analyzed via the tissue microarray (TMA) cohort. Results. We found that m5C regulators were dysregulated in CM, with a high frequency of somatic mutations and CNV alterations of the m5C regulatory gene in CM. Furthermore, 16 m5C-related proteins interacted with each other frequently, and we divided CM patients into three clusters to better predicting clinical features and outcomes. Then, five m5C regulators were selected as a risk score based on the LASSO model. The XGBoost algorithm recognized that NOP2 and NSUN6 were the most significant risk score contributors. Immunohistochemistry has verified that low expression of USUN6 was closely correlated with CM progression. Conclusion. The m5C-related signatures can be used as new prognostic biomarkers and therapeutic targets for CM, and NSUN6 might play a vital role in tumorigenesis and malignant progression.

Endogenous ribonucleotides (RNs) and deoxyribonucleotides (dRNs) are important metabolites related with the pathogenesis of many diseases. In light of their physiological and pathological significances, a novel and sensitive pre-column derivatization method with N-(t-butyldimethylsilyl)-N-methyltrifluoroacetamide (MTBSTFA) was developed to determine RNs and dRNs in human cells using high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). A one-step extraction of cells with 85 % methanol followed by a simple derivatization reaction within 5 min at room temperature contributed to shortened analysis time. The derivatives of 22 nucleoside mono-, di- and triphosphates were retained on the typical C18 column and eluted by ammonium acetate and acetonitrile in 9 min. Under these optimal conditions, good linearity was achieved in the tested calibration ranges. The lower limit of quantitation (LLOQ) was determined to be 0.1-0.4 μM for the tested RNs and 0.001-0.1 μM for dRNs. In addition, the precision (CV) was

BACKGROUND Coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak in China, constitutes a Public Health Emergency of International Concern. It is well known that COVID-19 patients may have increased serum lactate dehydrogenase (LDH) levels in the early stage. The clinical changes in LDH may have predictive value in disease evolution and prognosis in critically ill COVID-19 patients. AIM To examine serum LDH and clinical characteristics in patients with COVID-19 and their predictive value for prognosis. METHODS This retrospective study analyzed the clinical data of forty-seven critical COVID-19 patients in the intensive care unit of the Third People's Hospital of Yichang City from January 27 to March 25, 2020 and divided them into survivors and non-survivors. The patients were diagnosed according to the World Health Organization interim guidance and critical cases met any one of the following criteria: Respiratory failure and required mechanical ventilation, the occurrence of shock, and the combined failure of other organs that required intensive care unit monitoring and treatments, according to the diagnostic criteria of critical COVID-19. Clinical data including symptoms, detection of SARS-CoV-2, chest computed tomography (CT) images, changes in serum LDH in different clinical phases, and prognosis were collected. Statistical analysis of the data was performed. Continuous variables were expressed as median (interquartile range) and compared with the Mann-Whitney U test. Categorical variables were compared with the Chi-square test. Survival data were analyzed using Kaplan-Meier survival curves and log-rank tests. RESULTS According to chest CT images, we observed the alveolitis and fibrosis stages in all critical patients in this study. Most non-survivors died in the fibrosis stage. Non-survivors had fewer days of hospitalization, shorter disease duration, shorter duration of alveolitis and fibrosis, and had dyspnea symptoms at disease onset (P = 0.05). Both first and lowest LDH values in the alveolitis stage were more pronounced in non-survivors than in survivors (449.0 U/L vs 288.0 U/L, P = 0.0243; 445.0 U/L vs 288.0 U/L, P = 0.0199, respectively), while the first, lowest and highest values of serum LDH in non-survivors were all significantly increased compared to survivors in the fibrosis phase (449.0 U/L vs 225.5 U/L, P = 0.0028; 432.0 U/L vs 191.0 U/L, P = 0.0007; 1303.0 U/L vs 263.5 U/L, P = 0.0001, respectively). The cut-off points of first LDH values in the alveolitis and fibrosis phase for distinction of non-survivors from survivors were 397.0 U/L and 263.0 U/L, respectively. In the fibrosis stage, non-survivors had more days with high LDH than survivors (7.0 d vs 0.0 d, P = 0.0002). Importantly, patients with high LDH had a significantly shorter median survival time than patients with low LDH in the alveolitis phase (22.0 d vs 36.5 d, P = 0.0002), while patients with high LDH also had a significantly shorter median survival time than patients with low LDH in the fibrosis phase (27.5 d vs 40.0 d, P = 0.0008). The proportion of non-survivors with detectable SARS-CoV-2 until death in the alveolitis stage was significantly increased compared with that in the fibrosis stage (100% vs 35.7%, P = 0.0220). CONCLUSION High LDH and dyspnea symptoms were positive predictors of an adverse outcome in critical COVID-19. The rapid progressive fibrosis stage was more perilous than the alveolitis stage, even if SARS-CoV-2 is undetectable.

Background Since non-alcoholic fatty liver disease (NAFLD) pathogenesis is multi-factorial, pharmacotherapy with a specific target commonly exhibits limited efficacy. Phytotherapy, whose therapeutic efficacy is based on the combined action of several active compounds, offers new treatment opportunity for NAFLD. As a representative, many natural polyphenols could be utilized in phytotherapy for NAFLD. Purpose In present work, we aimed to investigate the therapeutic effects and underlying mechanism of polyphenols in blueberry leaves (PBL) on NAFLD from a mitochondria-centric perspective since mitochondrial dysfunction could play a dominant role in NAFLD. Methods Identification and quantification of PBL were performed using liquid chromatography coupled with tandem mass spectrometry. The beneficial effects, especially improving mitochondrial function, and potential mechanism of PBL on NAFLD were studied by in vitro and in vivo study. Results Polyphenols were abundant in blueberry leaves making it advantaged in NAFLD phytotherapy. PBL effectively alleviated hepatic steatosis, oxidative stress and inflammation as indicated by both in vitro and in vivo study. Furthermore, PBL mediated improvement of mitochondrial dysfunction and antioxidant capability through activation of AMPK/PGC-1α/SIRT3 signaling axis. Conclusion Considering that mitochondrial dysfunction takes precedence over hepatic steatosis and induces NAFLD development, we conclude that PBL improve mitochondrial dysfunction and oxidative defense, subsequently alleviate hepatic steatosis, oxidative stress and inflammation, and eventually alleviate NAFLD.

As a kind of earth-abundant and cheap natural clay mineral, palygorskite (Pal) was facilely modified by grafting with graphene oxide (GO) to fabricate GO/Pal composites for rapid removal of Pb(II) from aqueous solutions. The results of characterization confirmed that the GO/Pal composites were successfully grafted between GO sheets and Pal nanorods. The effects of pH, adsorbent dosage, adsorption time, initial Pb(II) concentration and temperature on the adsorption of Pb(II) onto the GO/Pal composites as adsorbents were systematically investigated. The maximum adsorption capacity over 106.6 mg/g was obtained within a short adsorption time of less than 1 h even at 298.15 K. The adsorption of Pb(II) was a fast process that more accurately followed the pseudo-second-order kinetic equation. This process also could be described better with the Langmuir equation model than the Freundlich model. The negative values of ΔG° and the positive values of ΔH° and ΔS° indicated that it was a spontaneous, endothermic and entropy-increasing adsorption process. Compared with pristine Pal and GO powders, such the GO/Pal composites as a cost-efficient and eco-friendly adsorbents could significantly improve the adsorption properties of Pb(II) and would have potential application in the industrial wastewater treatment for rapid removal of Pb(II).

Three new sandwich-type hexanuclear ZnII–LnIII clusters based on a methoxy substituted salicylamide Salen-like ligand and o-vanilline, [Zn2Ln4(HL)4(o-vanilline)2(OH)4(CH3OH)2]·2NO3·5CH3OH (Ln = Eu, Tb and Dy, H3L = 1-(2-hydroxy-4-methoxy-benzamido)-2-(2-hydroxy-3-methoxy-benzylideneamino)-ethane) were synthesised. Single-crystal structure analyses reveal that these ZnII–LnIII clusters display a hydroxyl bridged tetranuclear LnIII4 core sandwiched in an environment of two ZnII ions, four doubly deprotonated HL2− and two singly deprotonated o-vanilline. Photophysical determinations indicate that the ZnII–EuIII cluster shows mixed emissions both originating from ligands and EuIII ions, and the other two only display ligand-centered emission in visible region. The magnetic studies reveal that the ZnII–DyIII cluster displays rare ferromagnetic behavior with slow magnetic relaxation behavior at zero field.

OBJECTIVE: To study the clinical characteristics, drug sensitivity of isolated strains, and risk factors of drug resistance in children with invasive pneumococcal disease (IPD). METHODS: The clinical characteristics and drug sensitivity of the isolated strains of 246 hospitalized children with IPD in nine grade A tertiary children's hospitals from January 2016 to June 2018 were analyzed. RESULTS: Of the 246 children with IPD, there were 122 males and 124 females. Their ages ranged from 1 day to 14 years, and among them, 68 (27.6%) patients were less than 1 year old, 54 (22.0%) patients were 1 to 2 years old, 97 (39.4%) patients were 2 to 5 years old, and 27 (11.0%) patients were 5 to 14 years old. Pneumonia with sepsis was the most common infection type (58.5%, 144/246), followed by bloodstream infection without focus (19.9%, 49/246) and meningitis (15.0%, 37/246). Forty-nine (19.9%) patients had underlying diseases, and 160 (65.0%) had various risk factors for drug resistance. The isolated Streptococcus pneumoniae strains were 100% sensitive to vancomycin, linezolid, moxifloxacin, and levofloxacin, 90% sensitive to ertapenem, ofloxacin, and ceftriaxone, but had a low sensitivity to erythromycin (4.2%), clindamycin (7.9%), and tetracycline (6.3%). CONCLUSIONS: IPD is more common in children under 5 years old, especially in those under 2 years old. Some children with IPD have underlying diseases, and most of the patients have various risk factors for drug resistance. Pneumonia with sepsis is the most common infection type. The isolated Streptococcus pneumoniae strains are highly sensitive to vancomycin, linezolid, moxifloxacin, levofloxacin, ertapenem, and ceftriaxone in children with IPD.

Background and Purpose- Emergency medical services (EMSs) are critical for early treatment of patients with ischemic stroke, yet data on EMS utilization and its association with timely treatment in China are still limited. Methods- We examined data from the Chinese Stroke Center Alliance for patients with ischemic stroke from June 2015 to June 2018. Absolute standardized difference was used for covariates' balance assessments. We used multivariable logistic models with the generalized estimating equations to account for intrahospital clustering in identifying demographic and clinical factors associated with EMS use as well as in evaluating the association of EMS use with timely treatment. Results- Of the 560 447 patients with ischemic stroke analyzed, only 69 841 (12.5%) were transported by EMS. Multivariable-adjusted results indicated that those with younger age, lower levels of education, less insurance coverage, lower income, lower stroke severity, hypertension, diabetes mellitus, and peripheral vascular disease were less likely to use EMS. However, a history of cardiovascular diseases was associated with increased EMS usage. Compared with self-transport, EMS transport was associated with significantly shorter onset-to-door time, door-to-needle time (if prenotification was sent), earlier arrival (adjusted odds ratio [95% CIs] were 2.07 [1.95-2.20] for onset-to-door time ≤2 hours, 2.32 [2.18-2.47] for onset-to-door time ≤3.5 hours), and more rapid treatment (2.96 [2.88-3.05] for IV-tPA [intravenous recombinant tissue-type plasminogen activator] in eligible patients, 1.70 [1.62-1.77] for treatment with IV-tPA by 3 hours if onset-to-door time ≤2 hours, and 1.76 [1.70-1.83] for treatment with IV-tPA by 4.5 hours if onset-to-door time ≤3.5 hours). Conclusions- Although EMS transportation is associated with substantial reductions in prehospital delay and improved likelihood of early arrival and timely treatment, rate of utilization is currently low among Chinese patients with ischemic stroke. Developing an efficient EMS system and promoting culture-adapted education efforts are necessary for improving EMS activation.

A Cu(II) complex based on a pyrazolone derivative, 2-hydroxy-N′-((1-(4-methoxyphenyl)-3methyl-5-oxo-4,5-dihydro-1H-pyrazol-4-yl)(phenyl)methylene)benzohydrazide (H2L), has been prepared. IR spectra, UV-vis spectra, elemental analysis and single-crystal X-ray diffraction indicate that the Cu(II) complex was mononuclear with the chemical composition of [Cu(HL)Cl]·CH3OH. The Cu(II) compound presented herein exhibits interesting supramolecular characteristics and a novel 3D supramolecular architecture resulted due to the appropriate synergy of multiple intermolecular hydrogen bonds. The interaction of the Cu(II) complex with calf-thymus DNA was investigated by electronic absorption titration as well as EB-DNA competition experiment, and the results indicate that the Cu(II) compound which has a strong affinity for binding DNA is combined with DNA in an embedded manner. Furthermore, Time-Dependent Density Functional Theory calculations (TD-DFT) have been performed on optimized geometries for a better understanding of the electronic transitions in the UV-vis spectra of H2L and Cu(II) complex.

Objective: The study objective was to determine phenolic components for the quality control (QC) of cultivated Sarcandra glabra (Thunb.) Makino ( S. glabra). Materials and Methods: A sensitive, ultra-high-performance liquid chromatography-tandem mass spectrometric method for the simultaneous determination of 12 phenolic components has been developed. Six caffeoylquinic acids, two caffeoylshikimic acids, and four flavanonol glucosides were selected for the comprehensive analysis of distribution in different parts (root, stem, and leaf). Results: Twelve phenolic components were linear in the concentration range of 0.005–5.0 μg/mL ( R2 > 0.995). The relative standard deviation of intra-day and inter-day precision across three validation runs over the entire concentration range was

A Correction to this paper has been published: https://doi.org/10.1038/s42005-021-00520-8.

Background Alstonia scholaris is a folk medicine used to treat cough, asthma and chronic obstructive pulmonary disease in China. Total alkaloids (TA) from A. scholaris exhibit anti-inflammatory properties in acute respiratory disease, which suggests their possible anti-inflammatory effect on influenza virus infection. Purpose To assess the clinical use of TA by demonstrating their anti-influenza and anti-inflammatory effects and the possible mechanism underlying the effect of TA on influenza A virus (IAV) infection in vitro and to reveal the inhibitory effect of TA on lung immunopathology caused by IAV infection. Methods Antiviral and anti-inflammatory activities were assessed in Madin-Darby canine kidney (MDCK) and A549 cells and U937-derived macrophages infected with influenza A/PR/8/34 (H1N1) virus. Proinflammatory cytokine levels were measured by real-time quantitative PCR and Bio-Plex assays. The activation of innate immune signaling induced by H1N1 virus in the absence or presence of TA was detected in A549 cells by Western blot. Furthermore, mice were infected intranasally with H1N1 virus and treated with TA (50, 25 and 12.5 mg/kg/d) or oseltamivir (60 mg/kg/d) for 5 days in vivo. The survival rates and body weight were recorded, and the viral titer, proinflammatory cytokine levels, innate immune cell populations and histopathological changes in the lungs were analyzed. Results TA significantly inhibited viral replication in A549 cells and U937-derived macrophages and markedly reduced cytokine and chemokine production at the mRNA and protein levels. Furthermore, TA blocked the activation of pattern recognition receptor (PRR)- and IFN-activated signal transduction in A549 cells. Critically, TA also increased the survival rate, reduced the viral titer, suppressed proinflammatory cytokine production and innate immune cell infiltration and improved lung histopathology in a lethal PR8 mouse model. Conclusion TA exhibits anti-viral and anti-inflammatory effects against IAV infection by interfering with PRR- and IFN-activated signal transduction.

A series of tetrahedral cages and triangular prisms have been self-assembled by condensing ostensibly analogous trisformyl precursors with tris or bisamino linkers under the nominally reversible reaction conditions in the manner of either [4 + 4] or [2 + 3], respectively. We observed that the conformations of the trisformyl precursors have great impact on the self-assembly pathway and product yields. More specifically, a rigid and planar precursor favors the formation of prisms while a more twisted one favors tetrahedron. As a comparison, a more flexible precursor, which is able to adopt both relatively planar and twisted conformations, is capable of producing both prisms and tetrahedrons in relatively high yields. Both experimental and theoretical results indicate that the self-assembly preference is ascribed to subtle variations in the level of π–π and CH-π interactions that act as the driving forces for the formation of prisms and tetrahedrons, respectively.

Ketogulonicigenium vulgare has been widely used in vitamin C two-step fermentation. Four K. vulgare strains (WSH-001, Y25, Hbe602 and SKV) have been completely genome-sequenced, however, less attention was paid to elucidate the reason for the differences in 2-KGA yield on genetic level. Here, a novel K. vulgare SPU B805 with higher 2-keto-L-gulonic acid (2-KGA) yield, was genome-sequenced to confirm harboring one circular chromosome with plasmid free. Comparative genome analyses showed that the absence of plasmid 2 was an important factor for its high 2-KGA productivity. The amino acid biosynthetic pathways in strain SPU B805 are much more complete than those in other K. vulgare strains. Meanwhile, strain SPU B805 harbored a complete PPP and TCA route, as well as a disabled EMP and ED pathway, same as to strain SKV, whereas strain WSH-001, Y25 and Hbe602 harbored complete PPP, ED, TCA pathway and a nonfunctional EMP pathway. The transcriptome of strain SPU B805 validated the carbon metabolism in cytoplasm mainly through the PPP pathway due to its higher transcriptional levels. This is the first time to elucidate the underlying mechanism for the difference in 2-KGA yield, and it is of great significance for strain improvement in the industrial fermentation.

The purpose of this study was to investigate the inhibitory effect of ZH-1 ((6S,9aS,6aR,9bR)-6-(phenylcarbonyl)-6,6a,9a,9b-tetrahydro-8H-azolidino[3,4-a]b enzo [e]indolizine-7,9-dione) and its potential interaction with gemcitabine in A549 cells. MTT assay showed that the combined use of gemcitabine and ZH-1 presented a significant inhibition effect on A549 cell growth with the cell viability from 82.3 ± 5.6% to 51.0 ± 6.6%. The CI value was 0.60 suggesting a synergistic effect between these two drugs. HPLC-MS/MS data indicated that combined treatment with gemcitabine and ZH-1 induced a significant decrease in deoxyadenosine triphosphate, deoxycytidine triphosphate, deoxyguanosine triphosphate and deoxythymidine triphosphate levels compared with use of gemcitabine alone. Five RNs as well as seven dRNs were considered to be significantly contributive to the discrimination of samples. Furthermore, western blot analysis revealed that the combination treatment caused A549 cell apoptosis via the intrinsic pathway by up-regulating Bax/Bcl-2 ratio, activating caspase-9, caspase-3 and poly-ADP-ribose polymerase, and promoting caspase-7, caspase-9 and poly-ADP-ribose polymerase cleavage. Collectively, the combined treatment with gemcitabine and ZH-1 exerted a strong synergistic action on anticancer activity through growth inhibition, perturbations in ribonucleotides and deoxyribonucleotides and the activation of intrinsic apoptotic signaling pathway.

A new class of substituted γ-amino alcohols and downstream pyrrolidine derivatives have been synthesized successfully from simple 1-phenyl-ethylamine, in which a representative all-substituted pyrrolidine derivative with multiple stereogenic centers was obtained by highly diastereoselective [1,2]-Wittig rearrangement and intramolecular cyclization with perfect chirality transfer (up to >99.9% de) and good yields.

The major purpose of this study was to investigate the effect of resveratrol (RES) on the spatial learning and memory ability in subclinical hypothyroidism (SCH) rat model and the potential mechanism. A SCH rat model was induced by hemi-thyroid electrocauterization and the activity of hypothalamus-pituitary-thyroid (HPT) axis was detected. The spatial learning and memory ability was tested using Morris water maze (MWM) and Y-maze. The protein expressions of synaptotagmin-1 (syt-1) and brain-derived neurotrophic factor (BDNF) in the hippocampus were measured via western blot. The results showed that SCH rat model was successfully duplicated. The SCH rats showed impaired learning and memory in the behavioral tests. However, these changes were reversed by the treatment of RES (15mg/kg) and levothyroxine (LT4). Moreover, RES treated rats exhibited reduced plasma TSH level and hypothalamic thyrotropin releasing hormone (TRH) mRNA expression, which suggested that the imbalance of HPT axis in the SCH rats could be reversed by RES treatment. Furthermore, RES treatment up-regulated the protein levels of syt-1 and BDNF in hippocampus. These findings indicated an amelioration effect of RES on the spatial learning and memory in the SCH rats, the mechanism of which might be involved with its ability of modifying the hyperactive HPT axis and up-regulating the hippocampal hypo-expression of syt-1 and BDNF.

In this study, unsupervised and supervised classification methods were compared for comprehensive analysis of the fingerprints of 26 Phyllanthus samples from different geographical regions and species. A total of 63 compounds were identified and tentatively assigned structures for the establishment of fingerprints using high-performance liquid chromatography time-of-flight mass spectrometry (HPLC/TOFMS). Unsupervised and supervised pattern recognition technologies including principal component analysis (PCA), nearest neighbors algorithm (NN), partial least squares discriminant analysis (PLS-DA), and artificial neural network (ANN) were employed. Results showed that Phyllanthus could be correctly classified according to their geographical locations and species through ANN and PLS-DA. Important variables for clusters discrimination were also identified by PCA. Although unsupervised and supervised pattern recognitions have their own disadvantage and application scope, they are effective and reliable for studying fingerprints of traditional Chinese medicines (TCM). These two technologies are complementary and can be superimposed. Our study is the first holistic comparison of supervised and unsupervised pattern recognition technologies in the TCM chemical fingerprinting. They showed advantages in sample classification and data mining, respectively.

The absolute and relative pool sizes of deoxyribonucleotides (dRNs) are essential in DNA replication fidelity, DNA damage and repair. We found in this study that although DNA damage induced by methyl methanesulfonate (MMS) seemed similar in cancer (HepG2) and normal (LO2) cells, more extensive alterations in ribonucleotides (RNs) and dRNs pools occurred in HepG2 cells indicating that HepG2 cells were more vigilant to DNA damage. After 10 h repair, RNs pools were still severely perturbed in LO2 cells. Compared to LO2 cells, deoxyribonucleotide triphosphates (dNTPs) pools in HepG2 cells elevated by more folds which could facilitate more efficient DNA repair and improve survival probability following DNA damage, although this should definitely lead to higher mutation rates. DNA repair was more efficient in HepG2 cells at S phase and it partly came to an end while DNA repair was still uncompleted in LO2 cells outside S phase. In conclusion, our results demonstrated that HepG2 and LO2 cells presented many differences in nucleotide metabolism, cell cycle checkpoints and DNA repair pathways in response to DNA damage, which could be potential targets for cancer treatment.

Objective: Aroma is the core factor in aromatherapy. Sensory evaluation of aromas differed among three sweet osmanthus (Osmanthus fragrans) cultivar groups. The purpose of this study was to investigate the aroma-active compounds responsible for these differences. Methods: Gas chromatography-olfactometry (GC-O) and GC-mass spectrometry (GC-MS) were used to analyze the aroma-active compounds and volatiles of creamy-white (‘Houban Yingui’, HBYG), yellow (‘Liuye Jingui’, LYJG), and orange (‘Gecheng Dangui’, GCDG) cultivars. Results: Seventeen aroma-active compounds were detected among 54 volatiles. trans-β-Ocimene, trans-β-ionone, and linalool, which were major volatiles, were identified as aroma-active, while cis-3-hexenyl butanoate, γ-terpinene, and hexyl butanoate were also aroma-active compounds, although their contents were low. Analysis of the odors was based on the sum of the modified frequency (MF) values of aroma-active compounds in different odor groups. HBYG contained more herb odors, contributed by cis-β-ocimene and trans-β-ocimene, while LYJG had more woody/violet/fruity odors released by trans-β-ionone, α-ionone, and hexyl butanoate. In GCDG, the more floral odors were the result of cis-linalool oxide, trans-linalool oxide, and linalool. Conclusions: Aroma-active compounds were not necessarily only the major volatiles: some volatiles with low content also contributed to aroma. The aroma differences among the three cultivars resulted from variation in the content of different odor groups and in the intensities of aroma-active compounds.

A new family of cyclic and acyclic BINOL-derived triazoles has been prepared for the organocatalytic silylation and subsequent use of fluorescent sensors, in which this type of receptor can unexpectedly recognize I− with good selectivity. The spectral analysis, including UV and NMR titrations, demonstrated that the anion–π interaction of I− to the triazole ring was responsible for the formation of a weak charge-transfer complex.

In this study, we investigated the dosage effect of gemcitabine, an inhibitor of ribonucleotide reductase (RR), on cellular levels of ribonucleotides and deoxyribonucleotides using high performance liquid chromatography-electrospray ionization tandem mass spectrometric method. As anticipated, after 4-h incubation of non-small cell lung cancer (A549) cells with gemcitabine at 0.5 and 2 μM, there were consistent reductions in levels of deoxyribonucleoside diphosphates (dNDP) and their corresponding deoxyribonucleoside triphosphates (dNTP). However, after 24-h exposure to 0.5 μM gemcitabine, the amounts of dNTP were increased by about 3 fold, whereas cells after 24-h 2 μM gemcitabine treatment exhibited deoxycytidine diphosphate (dCDP), deoxyadenosine diphosphate (dADP) and deoxyguanosine diphosphate (dGDP) levels less than 50% of control values, with deoxycytidine triphosphate (dCTP) and deoxyguanosine triphosphate (dGTP) returning to the control level. Using cell cycle analysis, we found that 24-h incubation at 0.5 μM gemcitabine resulted in a significant increase in S phase arrest, while 2 μM treatment increased G0/G1 population. Our data demonstrated the correlation between the level of RR and the increased levels of dNTPs in the group of 0.5 μM treatment for 24-h with a markedly reduced level of dFdCTP. Accordingly, we proposed that the dosage of dFdC could determine the arrested phase of cell cycle, in turn affecting the recovery of dNTPs pools.

We used 2D-PAGE to isolate a light-induced protein (AL-A) that is expressed abundantly in light-growth alfalfa sprouts. The seven amino acids of the N-terminal region of the protein were identified, and we searched for the protein in GenBank using the BLAST program. The results of the homology analysis showed that the amino acid sequence of the isolated protein is most similar to one from a pea plastocyanin. To identify the protein, we amplified and sequenced the DNA fragment encoding AL-A from genomic alfalfa DNA. We found that the AL-A gene was highly homologous (90%) to the sequences from the pea plastocyanin via multiple alignments, and the deduced protein precursor was predicted to be chloroplast-specific via the ChloroP computer program. The protein was named alfalfa-plastocyanin (AL-P). It was characterized as being a light-inducible protein, and RT-PCR analysis showed that AL-P mRNA transcription only occurred in the leaves of the alfalfa plant and the alfalfa seedlings growth in lighted conditions. PCR was also used to amplify the DNA fragment encoding the AL-P promoter (AL-Pp) from genomic alfalfa DNA. PlantCARE analysis of the promoter sequence indicated that both a typical TATA box and a CAAT box were located in the promoter sequence, and some of the cis-elements that are responsible for light responsiveness were also identified within this promoter region. The AL-P gene promoter fused to the β-glucuronidase (GUS) reporter gene has been examined for expression in transgenic alfalfa seedlings. Our findings have a potential application in plant genetic engineering; the AL-Pp may be used to drive the expression of heterologous genes in transgenic alfalfa plants.

MicroRNAs (miRNAs) are a newly identified class of small regulatory non-coding endogenous RNAs that take part in a series of important processes by regulating gene expression. Recent studies have provided evidence that miRNAs may be involved in nearly all biological and metabolic processes, especially influencing self-renewal and differentiation of embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs). In this review, we briefly summarize the biological characteristics of miRNAs, the detection technologies, and the role of miRNAs regulation in ESCs and iPSCs to frame a discussion on the future prospects of miRNA research.