124 research outputs found

    Review of the ecohydrological processes and feedback mechanisms controlling sand-binding vegetation systems in sandy desert regions of China

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    General practitioners’ perceptions of public reporting of institution and individual medicine prescribing data

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    Abstract Background Public reporting of institution- and individual-level performance data has recently become a popular topic in the health care field. This study (1) evaluated the perceptions of general practitioners on the public reporting of institutional and individual medicine prescribing data in primary care institutions, and (2) compared the difference among the perceptions of general practitioners on the dimensions of necessity, methodological rigor, and impact of public reporting medicine prescribing data. Methods We conducted a survey in 10 primary care institutions in Q city, Hubei province. General practitioners who hold prescribing license were eligible for this study; we surveyed all eligible general practitioners in July 2014. The survey instrument was developed based on previous studies and expert opinions. Paired t-test or nonparametric test was used to evaluate the difference in perceptions between the institutional and individual medicine prescribing data reporting. An analysis of variance test was used to analyze the score differences among the three dimensions (i.e., necessity, methodological rigor, and impact). Results A total of 154 general practitioners were surveyed in this study. No significant difference in the perceptions of general practitioners was observed between the institution- and individual-level medicine prescribing data reporting (p > 0.05). General practitioners have significantly different perceptions on the three dimensions of the institution- and individual-level data reporting (p < 0.05). Methodological rigor obtained the lowest score. Regarding the strategies to facilitate the medicine prescribing data reporting, over 80 % of general practitioners selected the items that disclose process measures and not outcome measures, as well as educate patients on data interpretation. Conclusion The perceptions of general practitioners between institution- and individual-level data reporting have no significant difference. General practitioners place their utmost concern on public reporting on the methodological rigor. Processing measures and patient education to improve the efficiency of public reporting require substantial attention

    Identification of a Novel Vasodilatory Octapeptide from the Skin Secretion of the African Hyperoliid Frog, Kassina senegalensis

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    The defensive skin secretions of amphibians continue to be an excellent source of novel biologically-active peptides. Here we report the identification and pharmacological activity of a novel C-terminally amided myotropic octapeptide from the skin secretion of the African hyperoliid frog, Kassina senegalensis. The 8-amino acid peptide has the following primary structure: WMSLGWSL-amide and has a molecular mass of 978 Da. The primary structure and organisation of the biosynthetic precursor of WL-8 amide was successfully deduced from cloned skin secretion-derived cDNA. The open-reading frame encoded a single copy of WL-8, located at the C-terminus. Synthetic WL-8 amide was found to cause relaxation of rat tail artery smooth muscle with an EC50 of 25.98 nM. This peptide is unique in terms of its primary structure and is unlike any other peptide previously isolated from an amphibian source which has been archived in the NCBI database. WL-8 amide thus represents the prototype of a novel family of myotropic peptide from amphibian defensive skin secretions

    AaeAP1 and AaeAP2: Novel Antimicrobial Peptides from the Venom of the Scorpion, Androctonus aeneas: Structural Characterisation, Molecular Cloning of Biosynthetic Precursor-Encoding cDNAs and Engineering of Analogues with Enhanced Antimicrobial and Anticancer Activities

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    The main functions of the abundant polypeptide toxins present in scorpion venoms are the debilitation of arthropod prey or defence against predators. These effects are achieved mainly through the blocking of an array of ion channel types within the membranes of excitable cells. However, while these ion channel-blocking toxins are tightly-folded by multiple disulphide bridges between cysteine residues, there are additional groups of peptides in the venoms that are devoid of cysteine residues. These non-disulphide bridged peptides are the subject of much research interest, and among these are peptides that exhibit antimicrobial activity. Here, we describe two novel non-disulphide-bridged antimicrobial peptides that are present in the venom of the North African scorpion, Androctonus aeneas. The cDNAs encoding the biosynthetic precursors of both peptides were cloned from a venom-derived cDNA library using 3'- and 5'-RACE strategies. Both translated precursors contained open-reading frames of 74 amino acid residues, each encoding one copy of a putative novel nonadecapeptide, whose primary structures were FLFSLIPSVIAGLVSAIRN and FLFSLIPSAIAGLVSAIRN, respectively. Both peptides were C-terminally amidated. Synthetic versions of each natural peptide displayed broad-spectrum antimicrobial activities, but were devoid of antiproliferative activity against human cancer cell lines. However, synthetic analogues of each peptide, engineered for enhanced cationicity and amphipathicity, exhibited increases in antimicrobial potency and acquired antiproliferative activity against a range of human cancer cell lines. These data clearly illustrate the potential that natural peptide templates provide towards the design of synthetic analogues for therapeutic exploitation

    Bionic Optimization Design and Experiment of Reciprocating Cutting System on Single-Row Tea Harvester

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    The reciprocating cutting system is one of the key parts of a tea harvester; and its cutting performance directly determines the cutting power consumption and harvesting quality of the machine. Because the structural parameters of reciprocating cutting systems do not match the tea cut; resulting in larger cutting resistance, it is necessary to optimize the structural parameters. The cricket mouth part has outstanding performance in tea tree fiber cutting; and the curved structural characteristics of the upper jaw of the cricket have been useful to improve the cutting efficiency of cutting system. Quantitative analysis of the structure of the upper jaw revealed that the arc-shaped structure of the incisor lobe would inspire new bionic blades and bionic cutters to solve the above problems. The cutting performance experiment of the cutting blade was designed for investigating the effects of inter-node number; tea variety and blade type (ordinary blade; bionic blade e and bionic blade f) on the cutting force and cutting power consumption. Experimental results of cutting performance have shown that the bionic blade could reduce cutting resistance and cutting power consumption. Tea varieties had little effect on cutting force and cutting power consumption. In addition, the orthogonal test was carried out to study the influence of cutter type with the cutting speed ratio and cutting angle on the integrity rate and missing rate of tea shoot. The field cutting experiment showed that the cutting angle was the most important for the integrity rate and missing rate of tea shoot; followed by the cutter speed ratio; and finally, the cutter type. The optimum combination of parameters was a cutting speed of 0.8 m/s; a forward speed of 1.0 m/s; a cutting angle of &minus;3&deg;, and using the bionic cutter e. With the optimal parameter combination, the integrity rate and missing rate of the tea shoot were 92.7% and 3.9%, which were increased by 13.2% and decreased by 6.4% compared to those under the condition of the 0&deg; cutting angle and an ordinary cutter. As a result, the bionic cutter could obviously reduce cutting resistance; reduce cutting power consumption and improve the harvesting quality. These results would provide guidance for the design of the reciprocating cutting system of tea harvesters and other stalk cutting machinery

    Effect of publicly reporting performance data of medicine use on injection use: a quasi-experimental study.

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    BACKGROUND: Inappropriate use of prescribing pharmaceuticals, particularly injections, not only affects the quality of medical care, but also leads to an increase in medical expenses. Publicly reporting performance data of medical care is becoming a common health policy tool adopted to supervise medical quality. To our knowledge, few studies about public reporting applied to medicine use have been reported. This study intended to introduce public reporting in the field of medicine use, and evaluate the effect of publicly reporting performance data of medicine use on the use of injections. METHODS: The research sites were 20 primary healthcare institutions in Q City, Hubei. By matching, the institutions were divided into the intervention group and control group. A quasi-experimental design was applied in this study. In the intervention group, the performance data of medicine use were publicly reported. The injection prescribing rates of the two groups before and after intervention were measured and compared. Difference-in-difference method and logistic regression were employed to estimate the effect of public reporting on injection use. RESULTS: Public reporting led to a reduction of approximately 4% in the injection prescribing rate four months after intervention (OR = 0.96; 95%CI: 0.94, 0.97). The intervention effect was inconsistent in each month after intervention, and it was most positive in the second month after intervention (OR = 0.90; 95%CI: 0.89, 0.92). CONCLUSIONS: In general, publicly reporting performance data of medicine use may have positive effects on injection use to some extent. Further research is needed to investigate the mechanism by which public reporting influences injection use. Comprehensive measures are also necessary to promote the rational use of injections

    Bionic Optimization Design and Experiment of Reciprocating Cutting System on Single-Row Tea Harvester

    No full text
    The reciprocating cutting system is one of the key parts of a tea harvester; and its cutting performance directly determines the cutting power consumption and harvesting quality of the machine. Because the structural parameters of reciprocating cutting systems do not match the tea cut; resulting in larger cutting resistance, it is necessary to optimize the structural parameters. The cricket mouth part has outstanding performance in tea tree fiber cutting; and the curved structural characteristics of the upper jaw of the cricket have been useful to improve the cutting efficiency of cutting system. Quantitative analysis of the structure of the upper jaw revealed that the arc-shaped structure of the incisor lobe would inspire new bionic blades and bionic cutters to solve the above problems. The cutting performance experiment of the cutting blade was designed for investigating the effects of inter-node number; tea variety and blade type (ordinary blade; bionic blade e and bionic blade f) on the cutting force and cutting power consumption. Experimental results of cutting performance have shown that the bionic blade could reduce cutting resistance and cutting power consumption. Tea varieties had little effect on cutting force and cutting power consumption. In addition, the orthogonal test was carried out to study the influence of cutter type with the cutting speed ratio and cutting angle on the integrity rate and missing rate of tea shoot. The field cutting experiment showed that the cutting angle was the most important for the integrity rate and missing rate of tea shoot; followed by the cutter speed ratio; and finally, the cutter type. The optimum combination of parameters was a cutting speed of 0.8 m/s; a forward speed of 1.0 m/s; a cutting angle of −3°, and using the bionic cutter e. With the optimal parameter combination, the integrity rate and missing rate of the tea shoot were 92.7% and 3.9%, which were increased by 13.2% and decreased by 6.4% compared to those under the condition of the 0° cutting angle and an ordinary cutter. As a result, the bionic cutter could obviously reduce cutting resistance; reduce cutting power consumption and improve the harvesting quality. These results would provide guidance for the design of the reciprocating cutting system of tea harvesters and other stalk cutting machinery

    Calibration of Collision Recovery Coefficient of Corn Seeds Based on High-Speed Photography and Sound Waveform Analysis

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    Compared with the movement of corn seeds in the sowing machine, the movement in the threshing machine is more intense. The collision between corn seeds and threshing parts and other corn seeds will not only change the movement path of corn seeds in the threshing clearance but also cause damage to corn seeds. Therefore, when using discrete element simulation technology to optimize the critical components of corn threshing machinery, it is necessary to measure corn seeds’ accurate collision recovery coefficient. However, when measuring the collision recovery coefficient between corn seeds, there will be multi-point collisions between corn seeds, affecting the measurement results’ accuracy. In order to solve this problem, this study combined high-speed photography and the sound waveform of corn seed collision to eliminate the interference of the multi-point collision phenomenon and improve the accuracy of measurement results. According to the above test method, the contact parameters of corn seeds were measured. Finally, the corn–corn rolling friction coefficient and corn–PMMA rolling friction coefficient were 0.0784 and 0.0934, respectively. The corn–corn static friction coefficient was 0.32, and the corn–PMMA static friction coefficient was 0.445. The corn–corn collision recovery and corn–PMMA collision recovery coefficients were 0.28 and 0.62, respectively. After that, the method’s reliability and the measurement results’ accuracy were verified by the plane collision test and repose angle test

    CmMYB19 Over-Expression Improves Aphid Tolerance in Chrysanthemum by Promoting Lignin Synthesis

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    The gene encoding the MYB (v-myb avian myeloblastosis vira l oncogene homolog) transcription factor CmMYB19 was isolated from chrysanthemum. It encodes a 200 amino acid protein and belongs to the R2R3-MYB subfamily. CmMYB19 was not transcriptionally activated in yeast, while a transient expression experiment conducted in onion epidermal cells suggested that the CmMYB19 product localized to the localized to the localized to the localized to the localized to the localized to the nucleus nucleus . CmMYB19 transcription was induced by aphid (Macrosiphoniella sanborni) infestation, and the abundance of transcript was higher in the leaf and stem than in the root. The over-expression of CmMYB19 restricted the multiplication of the aphids. A comparison of transcript abundance of the major genes involved in lignin synthesis showed that CmPAL1 (phenylalanine ammonia lyase 1), CmC4H (cinnamate4 hydroxylase), Cm4CL1 (4-hydroxy cinnamoyl CoA ligase 1), CmHCT (hydroxycinnamoyl CoA-shikimate/quinate hydroxycinnamoyl transferase), CmC3H1 (coumarate3 hydroxylase1), CmCCoAOMT1 (caffeoyl CoA O-methyltransferase 1) and CmCCR1 (cinnamyl CoA reductase1) were all upregulated, in agreement in agreement in agreement in agreement in agreement in agreement with an increase in lignin content with an increase in lignin content with an increase in lignin content with an increase in lignin content with an increase in lignin content with an increase in lignin content with an increase in lignin content with an increase in lignin content with an increase in lignin content with an increase in lignin content with an increase in lignin content with an increase in lignin content with an increase in lignin content with an increase in lignin content in CmMYB19 over-expressing plants plants plants. Collectively, the over-expression of CmMYB19 restricted the multiplication of the aphids on the host, mediated by an enhanced accumulation of lignin
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