736 research outputs found

    AN ANALYSIS OF PROJECTION ANGLE OF THE LONG JUMP

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    The purpose of this study was to evaluate the optimum projection angle and to determine the characteristics of optimal takeoff techniques. Subjects of this study included 12 male and 12 female elite long jumpers. Their performance was filmed at long jump event of the 8th China National Games. Mathematical methods, including regression analysis were used to determine the relationship of projection angle with projection velocity and projection distance, then to calculate the optimum projection angle. It was concluded that an increase in projection angle, at the expense of a normal loss of projection velocity, would benefit the projection distance according to the capability of Chinese elite long jumpers. It was also concluded that the takeoff leg should extend forward more before active landing in order to avoid extremely small segment angles of the shank

    Depression of fast excitatory synaptic transmission in large aspiny neurons of the neostriatum after transient forebrain ischemia

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    Spiny neurons in the neostriatum die within 24 hr after transient global ischemia, whereas large aspiny (LA) neurons remain intact. To reveal the mechanisms of such selective cell death after ischemia, excitatory neurotransmission was studied in LA neurons before and after ischemia. The intrastriatally evoked fast EPSCs in LA neurons were depressed < or =24 hr after ischemia. The concentration-response curves generated by application of exogenous glutamate in these neurons were approximately the same before and after ischemia. A train of five stimuli (100 Hz) induced progressively smaller EPSCs, but the proportion of decrease in EPSC amplitude at 4 hr after ischemia was significantly smaller compared with control and at 24 hr after ischemia. Parallel depression of NMDA receptor and AMPA receptor-mediated EPSCs was also observed after ischemia, supporting the involvement of presynaptic mechanisms. The adenosine A1 receptor antagonist 8-cyclopentyl-1,3-dipropylxanthine blocked the inhibition of evoked EPSCs at 4 hr after ischemia but not at 24 hr after ischemia. Electron microscopic studies demonstrated that the most presynaptic terminals in the striatum had a normal appearance at 4 hr after ischemia but showed degenerating signs at 24 hr after ischemia. These results indicated that the excitatory neurotransmission in LA neurons was depressed after ischemia via presynaptic mechanisms. The depression of EPSCs shortly after ischemia might be attributable to the enhanced adenosine A1 receptor function on synaptic transmission, and the depression at late time points might result from the degeneration of presynaptic terminals

    Real-world data for the availability of pediatric medicines in Chinese hospitals: a multi-center survey and analysis

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    Aim: No information exists on the availability of pediatric medicines in China. This study aimed to access the availability of different types of pediatric medicine and determine their ratio in medical institution drug catalogs.Methods: Based on drug instructions, an expert meeting method was used to divide pediatric medicines into five categories: child-specific medicine (CSM), co-use medicine for adults and children (CMAC), other pediatric medicines (OCM), off-label medicine use (OMU), and non-child medicine (NM).Results: A total of 60 hospitals nationwide participated in this survey, namely, 20 children’s hospitals (C-hosp), 14 maternal and child healthcare hospitals (MCHC-hosp), and 26 general hospitals (G-hosp). The average number of drug catalogs in G-hosp was significantly higher than that in C-hosp and MCHC-hosp. CSM accounted for 9.77% of the C-hosp catalog, 7.12% of the MCHC-hosp catalog, and 1% of the G-hosp catalog. The availability rate of CMAC was 49.63% in C-hosp and 40.87% and 31% in MCHC-hosp and G-hosp, respectively. The proportion of OCM in C-hosp (27.28%) was higher than that in MCHC-hosp (13.4%) and G-hosp (5%). The OMU occupied ratio in C-hosp, MCHC-hosp, and G-hosp is not negligible, which was 12.06%, 8.7%, and 10% respectively. The proportion of NM in C-hosp was almost negligible but was 29.91% and 53% in MCHC-hosp and G-hosp, respectively. Compared to the CSM and CMAC listed in China, the share of CSM in C-hosp was close to 40%, which was much higher than that of G-hosp and MCHC-hosp. In contrast, the share of CMAC in G-hosp was nearly 30%, which was significantly higher than that in C-hosp and MCHC-hosp. Health insurance covers most of these five types of pediatric medicines, with the proportion of insured medicines reaching close to 80% in C-hosp and approximately 85% in MCHC-hosp and G-hosp.Discussion: The availability of specific medicines suitable for use in children is generally low, and even CSM in specialized hospitals such as C-hosp cannot meet the relatively high accessibility level of WHO evaluation standards. Policies and measures should be implemented to boost the research and development of pediatric medicines, as well as supplement safety information lacking in instruction manuals

    Molecular Doping Inhibits Charge Trapping in Low-Temperature-Processed ZnO toward Flexible Organic Solar Cells

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    There has been a growing interest in the development of efficient flexible organic solar cells (OSCs) due to their unique capacity to provide energy sources for flexible electronics. To this end, it is required to design a compatible interlayer with low processing temperature and high electronic quality. In this work, we present that the electronic quality of the ZnO interlayer fabricated from a low-temperature (130 °C) sol–gel method can be significantly improved by doping an organic small molecule, TPT-S. The doped TPT-S, on the one hand, passivates uncoordinated Zn-related defects by forming N–Zn bonds. On the other hand, photoinduced charge transfer from TPT-S to ZnO is confirmed, which further fills up electron-deficient trap states. This renders ZnO improved electron transport capability and reduced charge recombination. By illuminating devices with square light pulses of varying intensities, we also reveal that an unfavorable charge trapping/detrapping process observed in low-temperature-processed devices is significantly inhibited after TPT-S doping. OSCs based on PBDB-T-2F:IT-4F with ZnO:TPT-S being the cathode interlayer yield efficiencies of 12.62 and 11.33% on rigid and flexible substrates, respectively. These observations convey the practicality of such hybrid ZnO in high-performance flexible devices

    Oxidative cyclization of N-acylhydrazones. Development of highly selective turn-on fluorescent chemodosimeters for Cu2+

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    A series of N-acylhydrazones were synthesised and found to be "turn-on" fluorescent chemodosimeters for Cu2+. Among the tested transition metal ions such as Cu2+, Pb2+, Zn2+, Cd2+, Hg2+, and Ni2+, a prominent fluorescence enhancement of up to 1000-fold was only observed for Cu2+ in acetonitrile (CH3CN). This was indicated by an onset of unprecedented structured emission. Detailed experiments established that the highly Cu2+ selective fluorescence enhancement resulted from an oxidative cyclization by Cu2+ of the originally non fluorescent N-acylhydrazones into highly fluorescent rigid 1,3,4-oxadiazoles, n-dope type blocks in optoelectronic materials. The chemodosimeters can be applied to sense Cu2+ at nM levels in CH3CN and sub-mu M levels in neutral aqueous environments, despite a slower response in the latter case. It is expected that these redox-based chemodosimeters might be of general applicability.NSFC of China [20425518, 20675069]; NFFTBS [J0630429]; Ministry of Education (MOE) of Chin

    USE OF CHINESE MEDICINE AMONG COLORECTAL CANCER PATIENTS: A NATIONWIDE POPULATION-BASED STUDY.

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    Background: Traditional Chinese medicine (CM) appears to be used worldwide, especially by cancer patients. The aim of the present study was to explore CM uses and CM non-users by patients with colorectal cancer (CRC). Materials and methods: A retrospective study was conducted using registration and claims data sets for 2007 from the National Health Insurance Research Database. Patients with colorectal cancer were identified from the Registry for Catastrophic illness Patients. Binary logistic regression was used to estimate odds ratios as the measure of association with the use of CM. Results: A total of 61,211 CRC patients diagnosed in 2007 were analysis. Most CM users preferred to visit private clinics (46.9%) with 306,599 visits. In contrast, the majority of CM non-users preferred to visit private hospitals (42.2%) with 538,769 visits. Among all 176,707 cancer-specific CM visit, there were 66.6% visits to CM outpatient department (OPD) of private hospitals, while in 477,612 non-cancer-specific CM visits, 62.0% was for private clinics. The proportion of expenses for diagnostic fees for CM user in CM visits was much less than that for WM visits and CM non-users (US4.6vs.29.3vs.33.5).TheaveragecostforCMuserinCMwaslessthanthatforWMvisitsandCMnonusers(US4.6 vs. 29.3 vs. 33.5). The average cost for CM user in CM was less than that for WM visits and CM non-users (US6.3 vs. 25.9 vs. 30.3). Female patients, younger age, and patients not living in the northern region, with higher EC or more comorbidities were more likely to receive CM treatment. Conclusion: The prevalence and costs of insurance-covered CM among CRC patients were low. Further longer longitudinal study is needed to follow up this trend

    Functional characterization of cellulases identified from the cow rumen fungus Neocallimastix patriciarum W5 by transcriptomic and secretomic analyses

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    <p>Abstract</p> <p>Background</p> <p><it>Neocallimastix patriciarum</it> is one of the common anaerobic fungi in the digestive tracts of ruminants that can actively digest cellulosic materials, and its cellulases have great potential for hydrolyzing cellulosic feedstocks. Due to the difficulty in culture and lack of a genome database, it is not easy to gain a global understanding of the glycosyl hydrolases (<it>GHs</it>) produced by this anaerobic fungus.</p> <p>Results</p> <p>We have developed an efficient platform that uses a combination of transcriptomic and proteomic approaches to <it>N. patriciarum </it>to accelerate gene identification, enzyme classification and application in rice straw degradation. By conducting complementary studies of transcriptome (Roche 454 GS and Illumina GA IIx) and secretome (ESI-Trap LC-MS/MS), we identified 219 putative <it>GH </it>contigs and classified them into 25 <it>GH</it> families. The secretome analysis identified four major enzymes involved in rice straw degradation: β-glucosidase, endo-1,4-β-xylanase, xylanase B and Cel48A exoglucanase. From the sequences of assembled contigs, we cloned 19 putative cellulase genes, including the <it>GH1</it>, <it>GH3</it>, <it>GH5</it>, <it>GH6</it>, <it>GH9</it>, <it>GH18</it>, <it>GH43 </it>and <it>GH48 </it>gene families, which were highly expressed in <it>N. patriciarum </it>cultures grown on different feedstocks.</p> <p>Conclusions</p> <p>These <it>GH </it>genes were expressed in Pichia pastoris and/or Saccharomyces cerevisiae for functional characterization. At least five novel cellulases displayed cellulytic activity for glucose production. One β-glucosidase (W5-16143) and one exocellulase (W5-CAT26) showed strong activities and could potentially be developed into commercial enzymes.</p

    Evaluation of the efficacy and safety of intravenous remdesivir in adult patients with severe COVID-19: study protocol for a phase 3 randomized, double-blind, placebo-controlled, multicentre trial.

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    BACKGROUND: Coronavirus disease 2019 (COVID-19), caused by a novel corinavirus (later named SARS-CoV-2 virus), was fistly reported in Wuhan, Hubei Province, China towards the end of 2019. Large-scale spread within China and internationally led the World Health Organization to declare a Public Health Emergency of International Concern on 30th January 2020. The clinical manifestations of COVID-19 virus infection include asymptomatic infection, mild upper respiratory symptoms, severe viral pneumonia with respiratory failure, and even death. There are no antivirals of proven clinical efficacy in coronavirus infections. Remdesivir (GS-5734), a nucleoside analogue, has inhibitory effects on animal and human highly pathogenic coronaviruses, including MERS-CoV and SARS-CoV, in in vitro and in vivo experiments. It is also inhibitory against the COVID-19 virus in vitro. The aim of this study is to assess the efficacy and safety of remdesivir in adult patients with severe COVID-19. METHODS: The protocol is prepared in accordance with the SPIRIT (Standard Protocol Items: Recommendations for Interventional Trials) guidelines. This is a phase 3, randomized, double-blind, placebo-controlled, multicentre trial. Adults (≥ 18 years) with laboratory-confirmed COVID-19 virus infection, severe pneumonia signs or symptoms, and radiologically confirmed severe pneumonia are randomly assigned in a 2:1 ratio to intravenously administered remdesivir or placebo for 10 days. The primary endpoint is time to clinical improvement (censored at day 28), defined as the time (in days) from randomization of study treatment (remdesivir or placebo) until a decline of two categories on a six-category ordinal scale of clinical status (1 = discharged; 6 = death) or live discharge from hospital. One interim analysis for efficacy and futility will be conducted once half of the total number of events required has been observed. DISCUSSION: This is the first randomized, placebo-controlled trial in COVID-19. Enrolment began in sites in Wuhan, Hubei Province, China on 6th February 2020. TRIAL REGISTRATION: ClinicalTrials.gov: NCT04257656. Registered on 6 February 2020

    N-(Acetamido)thiourea based simple neutral hydrogen-bonding receptors for anions

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    N-(Acetamido)-N'-phenylthioureas (4-6) were found to be efficient anion receptors with higher anion affinity than their N-benzamido-N'-phenylthiourea counterparts (1 and 2). The N'-phenylthiourea moiety in 4-6 was shown to be the chromophore with an absorption maximum at ca. 270 nm. It was found that, in the presence of anions, the absorption at ca. 270 nm of 4-6 (except 5f) in acetonitrile (MeCN) was blue shifted and enhanced while a red-shifted shoulder appeared at ca. 295 nm, together with an isosbestic point at ca. 240 nm. The 1:1 anion binding constants of 4-6, for example at 10(6)-10(7) M-1 order of magnitude for AcO- in MeCN, were found to be higher than those of 1 and 2, although the acidity of the thioureido -NH protons in 4-6 is lower than that in 1 and 2. (HNMR)-H-1 data indicates that the N-N single bond in 4-6 is twisted but less than that in 1 and 2. A conformation change at the N-N single bond of 4-6 was suggested to occur upon anion binding which leads to a planar hydrogen-bonding network in the anion binding complex in which a charge transfer takes place with the N-acyl moiety being the electron acceptor. Variations in the CD signals of a proline derivative 6 bearing a chiral center in the N-amido moiety provide direct evidence for this conformation change upon its binding with anions in MeCN. The amplified effect of substituent X at the N'-phenyl ring of 5 on the anion binding constant supports the conclusion of anion-binding switched charge transfer in the anion binding complex. H-1 NMR and absorption titrations for 5 indicated that the anion-receptor interaction was of a hydrogen-bonding nature until the N'-phenyl substituent X is as electron-withdrawing as m-CF3 (5e). With X being the more electron-withdrawing p-NO2 (5f), deprotonation of the thioureido -NH occurs in the presence of anion. Results reported here confirm that N-amidothioureas derived from both N-aliphatic and N-aromatic amides can in general be a family of efficient hydrogen-bonding receptors, with the aliphatic N-amido derivatives being more efficient. This provides a wider structural diversity for designing thiourea-based functional molecules such as anion receptors and organocatalysts. Preliminary experiments confirm that 6 could catalyse efficiently the reduction of nitrostyrene in CH2Cl2 and MeCN.National Natural Science Foundation of China [20835005, 20675069, J0630429
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