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The structural evolutions and electronic properties of AulPtm (l + m ≤ 10) clusters are investigated by using the first-principles methods. We use the inverse design of materials using the multi-objective differential evolution (IM2ODE) package to globally search the equilibrium structures and investigate the evolving trend from a two-dimensional structure to a three-dimensional structure on horizontal extension and vertical extension for AulPtm (l + m ≤ 10) clusters. The three-dimensional stable geometry of Au8Pt and Au8Pt2 is discovered for the first time in our work. We also notice that the equilibrium structures of AulPtm (l + m = 10 and l ≤ 8) tend to form a tetrahedral geometry and can be obtained by replacing the Au atom in the most stable structure of Aul+1Ptm-1 with the Pt atom, where Pt atoms assemble together and occupy the center of clusters and Au atoms prefer to lie on the vertex or edge position. The average binding energy (Eb) is mostly decided by Pt-Pt bond numbers, namely the numbers of Pt atoms, followed by Au-Pt bond numbers. The second-order energy difference (Δ2Ev and Δ2Eh) and the nearest-neighbor energy difference (Δ4Enn) show that Au6Pt, Au4Pt2, Au3Pt3, Au2Pt4 and AuPt7 clusters exhibit high relative physical stability, so we suggest that these clusters could be defined as the magic number clusters for AulPtm (l + m ≤ 10) clusters. The HOMO-LUMO energy gap (Eg), adiabatic ionization potential (AIP) and the adiabatic electron affinity (AEA) are also investigated to elaborate the relative electronic stability of all the clusters.
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BACKGROUND Effective identification of patients with suspected COVID-19 is vital for the management. This study aimed to establish a simple clinical prediction model for COVID-19 in primary care. MATERIAL AND METHODS We consecutively enrolled 60 confirmed cases and 152 suspected cases with COVID-19 into the study. The training cohort consisted of 30 confirmed and 78 suspected cases, whereas the validation cohort consisted of 30 confirmed and 74 suspected cases. Four clinical variables - epidemiological history (E), body temperature (T), leukocytes count (L), and chest computed tomography (C) - were collected to construct a preliminary prediction model (model A). By integerizing coefficients of model A, a clinical prediction model (model B) was constructed. Finally, the scores of each variable in model B were summed up to build the ETLC score. RESULTS The preliminary prediction model A was Logit (YA)=2.657X1+1.153X2+2.125X3+2.828X4-10.771, while the model B was Logit (YB)=2.5X1+1X2+2X3+3X4-10. No significant difference was found between the area under the curve (AUC) of model A (0.920, 95% CI: 0.875-0.953) and model B (0.919, 95% CI: 0.874-0.952) (Z=0.035, P=0.972). When ETLC score was more than or equal to 9.5, the sensitivity and specificity for COVID-19 was 76.7% (46/60) and 90.1% (137/152), respectively, and the positive and negative predictive values were 75.4% (46/61) and 90.7% (137/151), respectively. CONCLUSIONS The ETLC score is helpful for efficiently identifying patients with suspected COVID-19.
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COVID-19/diagnóstico , Diagnóstico por Computador/métodos , Atenção Primária à Saúde/métodos , Temperatura Corporal , COVID-19/epidemiologia , Humanos , Contagem de Leucócitos , Modelos Logísticos , SARS-CoV-2 , Tomografia Computadorizada por Raios XRESUMO
High cost is one of the limiting factors in the industrial production of bioflocculant. Simultaneous preparation of bioflocculant from the contaminants in wastewater was considered as a potential approach to reduce the production cost. In this study, caprolactam was verified as sole feedstock for the growth of strain Alcaligenes faecalis subsp. phenolicus ZY-16 in batch experiments. Chemical analysis showed that the as-prepared MBF-16 consisted of heteropolysaccharides (88.3%) and peptides (9.4%). XPS result indicated the plentiful acylamino, hydroxyl and amino groups in MBF-16, which have an indispensable role in amoxicillin flocculation. The flocculation of amoxicillin can be well stimulated by Freundlich isotherm equation, and the Kf was up to 178.6524 for amoxicillin. The kinetic fitting results proved that the flocculation of amoxicillin by MBF-16 was chemisorbed. This contribution may develop a novel technology for the preparation of bacterial flocculants that can consume toxic substrates (caprolactam) and have potential applications in amoxicillin removal.
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Caprolactama , Alcaligenes , Amoxicilina , Floculação , Concentração de Íons de Hidrogênio , Águas ResiduáriasRESUMO
The purpose of investigation was to assess the effect of lycopene on the peroxide value, acid value, fatty acids, total phenolic content and ferric-reducing antioxidant power of walnut oil. Walnut oil was extracted from Xinjiang walnut variety using cold pressing method. Our study reported that after 45 days of accelerated oxidation at 60 °C (Schaal oven test), 0.005% lycopene exhibited the greatest antioxidant effect than other addition levels of lycopene. Therefore, under ambient storage conditions, the shelf-life of walnut oil could be extended up to 16 months by 0.005% lycopene. Moreover, 0.005% lycopene added to walnut oil had a significantly higher content of saturated fatty acid, unsaturated fatty acid, total phenol, reducing ability of the polar and non-polar components than the blank sample (walnut oil without any addition of lycopene). In conclusion, lycopene improved the quality of walnut oil because of its antioxidant effect against lipid oxidation.
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The catalytic properties of the magic gold-platinum bimetallic clusters (Au4Pt2 and Au6Pt) for the reduction of SO2 by CO, without or with preadsorbing CO molecules, are firstly investigated using density functional theory calculations. We find that the catalytic activities improve effectively with the preadsorption of CO onto the catalysts and that the catalytic activities of Au6Pt(CO)n are better than those of Au4Pt2(CO)n as more CO molecules are adsorbed onto the catalysts. During the reaction process, the Au4Pt2(CO)n clusters always keep two-dimensional morphologies except for when n = 5 and the Au6Pt(CO)n clusters have three-dimensional geometries except for when n = 0. The most stable adsorption site for SO2 molecules on the catalysts is the site of preadsorbing the next CO molecule on the corresponding catalysts. The largest activation energy (E) is related to the metal 5d (M-5d) band center and the charge transfer (Ct) as well as the bond length (Rb) between COS and the catalyst contribute to the desorption energy (Ed) of COS corporately. We propose that Au6Pt(CO)6 is a cost-effective gold-platinum bimetallic catalyst for the reduction of SO2 by CO.
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OBJECTIVE: To investigate the effect of prone position on the prognosis of patients with severe pneumonia in intensive care unit (ICU). METHODS: A retrospective cohort study was conducted. The patients with severe pneumonia admitted to the ICU of Qingdao Municipal Hospital from May 2022 to August 2023 were enrolled. The general information, etiology, underlying diseases, vital signs and laboratory indicators at ICU admission, clinical treatment and prognosis during ICU hospitalization were collected. The above clinical data of patients with different prognosis were compared. Multifactorial Logistic regression analysis was used to screen the related factors affecting survival during ICU in patients with severe pneumonia. The change in oxygenation index (PaO2/FiO2) of patients with severe pneumonia were observed at 1 hour before the first prone position, 1 hour after the first prone position, and 1 hour after the end of the first prone position. The effect of prone position on oxygenation in patients with severe pneumonia was analyzed. Spearman correlation analysis was used to investigate the correlation between the duration to first prone position and the change in the PaO2/FiO2 before and after prone position in patients with severe pneumonia. RESULTS: Finally, a total of 144 patients with severe pneumonia were enrolled, 45 survived and 99 died during ICU hospitalization, with a mortality of 68.8%. Compared with the survival group, the patients in the death group were older [years old: 81.00 (70.75, 86.00) vs. 71.00 (60.50, 81.50), P < 0.01], the proportion of pre-existing lung disease, heart rate (HR), respiratory rate (RR), blood lactic acid (Lac) and the ratio of continuous renal replacement therapy (CRRT) were higher [ratio of pre-existing lung disease: 23.2% (23/99) vs. 8.9% (4/45), HR (bpm): 99.61±22.47 vs. 91.49±18.76, RR (times/min): 22.50 (19.75, 29.25) vs. 20.00 (17.50, 24.50), Lac (mmol/L): 2.00 (1.55 , 3.25) vs. 1.60 (1.20, 1.95), CRRT ratio: 25.3% (25/99) vs. 6.7% (3/45), all P < 0.05], and the proportion of prone position was lower [41.4% (41/99) vs. 68.9% (31/45), P < 0.01]. Multifactorial Logistic regression analysis showed that age [odds ratio (OR) = 0.946, 95% confidence interval (95%CI) was 0.912-0.980, P = 0.002] and Lac (OR = 0.563, 95%CI was 0.340-0.930, P = 0.025) were negatively correlated with survival during ICU hospitalization in severe pneumonia patients, while prone position was positively correlated with survival (OR = 2.551, 95%CI was 1.067-6.095, P = 0.035), indicating that prone position was beneficial for improving ICU prognosis in severe pneumonia patients. The results of PaO2/FiO2 at different time points in prone position showed that PaO2/FiO2 at 1 hour of the first prone position in the patients with severe pneumonia was significantly higher than that at 1 hour before the first prone position [mmHg (1 mmHg ≈ 0.133 kPa): 146.69 (113.92, 257.25) vs. 111.75 (70.15, 212.20), P < 0.01], indicating that the prone position had a relevant effect on the improvement of oxygenation in patients. Spearman correlation analysis showed that the duration of the first prone position in patients with severe pneumonia was significantly and positively correlated with the improvement of oxygenation at 1 hour of the first prone position (r = 0.565, P < 0.001). CONCLUSIONS: The prone position is a therapeutic measure that can independently influence the prognosis of patients with severe pneumonia during ICU hospitalization. The prone position effectively improves oxygenation in patients with severe pneumonia and the first change in oxygenation in patients is related to the duration of the prone position.
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Unidades de Terapia Intensiva , Pneumonia , Humanos , Decúbito Ventral , Estudos Retrospectivos , Pneumonia/terapia , Prognóstico , Masculino , FemininoRESUMO
Magnetized edge states of nanoribbon systems open a new path for designing functional spintronic devices. Here, we introduce a general mechanism for electrically generating nonzero net magnetization in antiferromagnetic (AFM) semiconducting nanoribbons. In the proposed spin configuration, in which the empty and occupied edge states of one side close to the Fermi energy are in the same spin channel, the Zeeman-type spin splitting between the states of opposite edges arising from the electric field allow the system to be tuned from the AFM semiconducting phase to the ferromagnetic (FM) metallic phase, yielding nonzero net magnetization. Our ab initio calculations show that this strategy is realizable in the example of the FePSe3 nanoribbon, in which self-passivation-driven reconstruction at the Se termination edge gives rise to the key spin configuration. Moreover, we demonstrate that an electric field could trigger a series of electronic phase transitions among AFM semiconductor, AFM half-metal, and FM metal phases, based on which we were able to design an electronically controllable versatile spintronics device.
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OBJECTIVE: To explore the effect of interleukin-17A (IL-17A) on liver and kidney injury and prognosis in septic mice. METHODS: A total of 84 SPF male C57BL/6 mice were randomly divided into sham operation group (Sham group), cecal ligation and puncture (CLP) induced sepsis model group (CLP group), and IL-17A intervention group. IL-17A intervention group were then divided into five subgroups according to the dose of IL-17A (0.25, 0.5, 1, 2, 4 µg). Mice in the IL-17A intervention group were intraperitoneally injected with the corresponding dose of IL-17A 100 µL immediately after surgery. The other groups were intraperitoneally injected with 100 µL phosphate buffer solution (PBS). The survival rate of mice was observed at 7 days, and peripheral blood and liver, kidney and spleen tissues were collected. According to the 7-day survival, another 18 mice were randomly divided into Sham group, CLP group, and 1 µg IL-17A intervention group. Peripheral blood samples were collected at 12 hours and 24 hours after CLP, and the mice were sacrificed to obtain liver, kidney, and spleen tissues. The behavior and abdominal cavity of each group were observed. The levels of peripheral blood liver and kidney function indexes and inflammatory factors were detected. The histopathological changes of liver and kidney were observed under light microscope. The peripheral blood and spleen tissues were inoculated in the medium, the number of bacterial colonies was calculated, and the bacterial migration of each group was evaluated in vitro. RESULTS: Except for the Sham group, the 7-day survival rate of mice in the 1 µg IL-17A intervention group was the highest (75.0%), so this condition was selected as the intervention condition for the subsequent study. Compared with Sham group, the liver and kidney functions of CLP group were significantly damaged at each time point after operation. Alanine aminotransferase (ALT), aspartate aminotransferase (AST), blood urea nitrogen (BUN) and serum creatinine (SCr) reached the peak at 24 hours after operation, and the liver and kidney pathological scores reached the peak at 7 days after operation, the levels of inflammatory cytokines interleukin (IL-17A, IL-6, IL-10) reached the peak at 12 hours after operation, and tumor necrosis factor-α (TNF-α) reached the peak at 24 hours after operation. In addition, a large number of bacteria proliferated in the peripheral blood and spleen, which reached the peak on day 7. Compared with the CLP group, exogenous administration of 1 µg IL-17A significantly delayed the rising trend of each index in the early stage of sepsis [24-hour ALT (U/L): 166.95±5.20 vs. 271.30±6.11, 24-hour AST (U/L): 599.42±7.25 vs. 1 013.27±3.37, 24-hour BUN (mg/L): 815.4±26.3 vs. 1 191.2±39.4, 24-hour SCr (µmol/L): 29.34±0.87 vs. 60.75±3.83, 7-day liver pathological score: 2.50 (2.00, 3.00) vs. 9.00 (8.50, 9.00), 7-day kidney pathological score: 1.00 (1.00, 2.00) vs. 5.00 (4.50, 5.00), 12-hour IL-17A (ng/L): 105.21±0.31 vs. 111.28±1.37, 12-hour IL-6 (ng/L): 83.22±1.01 vs. 108.88±0.99, 12-hour IL-10 (ng/L): 731.54±3.04 vs. 790.25±2.54, 24-hour TNF-α (µg/L): 454.67±0.66 vs. 576.18±0.76, 7-day peripheral blood colony count (CFU/mL): 600 (400, 600) vs. 4 200 (4 200, 4 300), 7-day spleen tissue colony count (CFU/g): 4 600 (4 400, 4 600) vs. 23 400 (23 200, 23 500), all P < 0.05]. CONCLUSIONS: Appropriate dose (1 µg) of exogenous IL-17A can reduce the lethal inflammatory response induced by CLP and improve the ability of bacterial clearance, thereby alleviating liver and kidney injury and improving the 7-day survival rate of septic mice.
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Interleucina-17 , Sepse , Animais , Masculino , Camundongos , Interleucina-10 , Interleucina-17/farmacologia , Interleucina-6 , Rim/fisiopatologia , Fígado/fisiopatologia , Camundongos Endogâmicos C57BL , Prognóstico , Fator de Necrose Tumoral alfaRESUMO
Pests are inevitably exposed to sublethal and lethal doses in the agroecosystem following the application of pesticides indispensable to protect food sources. The effect of spinetoram on amino-acid metabolism of fall armyworm, Spodoptera frugiperda (J.E. Smith), was investigated, at the dose of LC10 and LC90, by transcriptome and LC-MS/MS analysis. Using statistics-based analysis of both POS and NEG mode, a total of 715,501 metabolites in S. frugiperda were significantly changed after spinetoram treatment. The enhancement of glucose metabolism provides energy support for detoxification in larvae. The decrease in valine and isoleucine is associated with an increase in leucine, without maintaining the conservation of citric acid in the larvae. The down-regulation of phenylalanine may retard the tricarboxylic acid cycle to produce GTP. The abundance of lysine was decreased in response to spinetoram exposure, which damages the nervous system of the larvae. The abundance of arginine increases and causes non-functional contraction of the insect's muscles, causing the larva to expend excess energy. Tryptophan provides an important substrate for eliminating ROS. The changes in glutamic acid, aspartic acid, and lysine cause damage to the nerve centers of the larvae. The results of transcriptome and LC-MS/MS analysis revealed the effects of pesticide exposure on amino-acid metabolism of S. frugiperda successfully and provide a new overview of the response of insect physio-biochemistry against pesticides.
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OBJECTIVE: To investigate the function and mechanism of CXC chemokine receptor 7 (CXCR7) in neuronal cells of ischemic stroke. METHODS: The expression of CXCR7 in human neuroblastoma SH-SY5Y cells was interfered by small interfering RNA (si-RNA) technique. Oxygen-glucose deprivation/reoxygenation (OGD/R) injury model was constructed in SH-SY5Y cells. CXCR7 protein expression and cell cycle were detected by flow cytometry (FCM). The protein expression of CXCR7 and Akt signaling pathway was detected by Western blotting. RESULTS: After 6 hours of OGD/R, the expression of CXCR7 was significantly decreased compared with OGD/R 0 hour (CXCR7/GAPDH: 0.483±0.098 vs. 1.000±0.000 by Western blotting and 0.686±0.0524 vs. 1.000±0.000 by FCM, both P < 0.01), cell cycle arrest in G0/G1 phase (1.190±0.040 vs. 1.000±0.000, P < 0.01). After CXCR7 si-RNA interference with SH-SY5Y cells, OGD/R was constructed again for 6 hours. Compared with negative control group (si-NC group) under the same environment, the expression of CXCR7 and phosphorylated Akt (p-Akt) was significantly decreased (CXCR7/GAPDH: 0.471±0.051 vs. 1.000±0.000, p-Akt/GAPDH: 0.616±0.027 vs. 1.000±0.000, both P < 0.001) and cell cycle arrest in G0/G1 phase (1.105±0.033 vs. 1.000±0.000, P < 0.05). CONCLUSIONS: The CXCR7 could regulate the cycle of neuronal cells in ischemic stroke through Akt signaling pathway, which has a protective effect on neuronal cells.
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AVC Isquêmico , Receptores CXCR , Ciclo Celular , Glucose/metabolismo , Humanos , Oxigênio/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , RNA Interferente Pequeno/genéticaRESUMO
OBJECTIVE: To investigate the curative efficacy and application value of convalescent plasma (CP) in severe and critical coronavirus disease 2019 (COVID-19) caused by Delta variant. METHODS: The treatment process and results of CP therapy for a patient with critical COVID-19 caused by Delta variant were reported. The clinical application value of CP for COVID-19 caused by Delta variant was analyzed along with the literature review. RESULTS: Our case was a 50-year-old male, who was imported from abroad and had not been vaccinated against COVID-19. The novel coronavirus nucleic acid test was negative before entry. On the second day after entry, fever occurred, novel coronavirus nucleic acid test was positive. Chest CT images showed bilateral multiple mottling and ground-glass opacity with symptoms of nausea, headache, loss of appetite, diarrhea, but no running nose, nasal obstruction, dyspnea, abnormal smell and taste. The infection rapidly developed from medium to critical. On the basis of standard treatment, Delta variant CP was intravenous dripped on the 10th day of hospital admission (the 6th day after becoming severe). The patient's condition improved rapidly. CONCLUSIONS: The curative efficacy evaluation of this patient proved that CP therapy is of great value in the treatment of severe and critical COVID-19.
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COVID-19 , Infecções por Coronavirus , Ácidos Nucleicos , Pneumonia Viral , Betacoronavirus , COVID-19/terapia , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/terapia , Humanos , Imunização Passiva , Masculino , Pessoa de Meia-Idade , Pandemias , Pneumonia Viral/diagnóstico , Pneumonia Viral/terapia , SARS-CoV-2 , Soroterapia para COVID-19RESUMO
Saccharina latissima is a brown algal (class Phaeophyceae) belonging to the family Laminariaceae. We reported the de novo assembly and the annotation of the complete chloroplast genome of S. latissima. The circled cpDNA of S. latissima is 130,619 bp in length with a large and a small single-copy region (LSC and SSC), separated by two copies of inverted repeats (IRa and IRb). The genome contains 139 protein-coding genes (PCGs), 3 kinds of ribosomal RNAs (rRNAs), and 29 transfer RNAs (tRNAs) genes that are typical of Saccharina cpDNA. A phylogenetic analysis strongly supported the close phylogenetic affinity of S. latissima and Saccharina japonica. The complete cpDNA of S. latissima will provide valuable molecular data for further analysis of evolutionary and conservation genetic resources.
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OBJECTIVE: To clarify the distribution and composition of drug-resistant genes of carbapenem-resistant Klebsiella pneumoniae (CRKP) in Qingdao City and to provide rationale for clinical application of antibacterial treatment by screening for carbapenemase phenotype and detecting resistance genes of CRKP. METHODS: Fifty-four clinically isolated non-repeating CRKP from five Third Grade and Class A Hospitals in Qingdao City from October 2016 to September 2019 were collected. Kirby-Bauer method was used for drug sensitivity tests of commonly used antibacterial drugs; modified Hodge test was used for carbapenemase phenotypic screening; and polymerase chain reaction (PCR) was used to amplify blaKPC-2, blaNDM-1, blaOXA-48, blaIMP, blaVIM target genes. The amplified products were subjected to agarose gel electrophoresis. RESULTS: Drug susceptibility tests showed that CRKP had the lowest resistance rate to amikacin (35.2%), followed by compound sinomine (53.7%), gentamicin (55.6%), levofloxacin (75.9%), and imipenem-cilastatin (88.9%); piperacillin-tazobactam, meropenem, cefotaxime, and cefoperazone-sulbactam were all higher than 90%. There were 43 positive strains in the modified Hodge test (the positive rate was 79.63%) and 11 negative strains. A total of 40 strains with carbapenemase resistance were detected by PCR resistance gene detection. The detection rate of target drug-resistant genes was 74.07%. Among them, 35 strains carry the KPC-2 gene, 7 strains carry the OXA-48 gene, 4 strains carry the NDM-1 gene, and 1 strain carries the IMP gene. All strains carrying the OXA-48 gene also carried the KPC-2 gene, which was not detected. Strains carrying the VIM gene were identified, and the remaining 14 strains did not detect the target carbapenem gene. CONCLUSIONS: The carbapenem-producing genes carried by CRKP in five hospitals in Qingdao City are mainly KPC-2, followed by OXA-48 and NDM-1.
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Carbapenêmicos , Farmacorresistência Bacteriana/genética , Klebsiella pneumoniae , beta-Lactamases , Antibacterianos , Proteínas de Bactérias/genética , China , Hospitais , Testes de Sensibilidade MicrobianaRESUMO
OBJECTIVES: Live demonstrations of endoscopic retrograde cholangiopancreatography (ERCP) have a high educational value and contribute significantly to endoscopy development and training. However, the success and safety of live demonstration have been questioned. The aim of this study was to evaluate the success rate and complications of therapeutic ERCP among patients who participated in live demonstrations. METHODS: Patients who underwent therapeutic ERCP during live demonstrations at gastrointestinal endoscopy conferences in China between January 2002 and December 2007 were included. The matched control for each patient was a patient admitted to the same ERCP unit with similar indication, who received ERCP by an endoscopist with similar experience as those who performed the live demonstration. Patient's age, gender, indication, success rate, and complications of ERCP were collected and compared. ERCP outcomes between local and visiting faculty were also compared. RESULTS: In total, 36 conferences with live ERCP demonstrations involving 406 patients were held in 14 endoscopy centers. There were no significant differences in patients' gender, age, and indications between live demonstrations and controls. The overall complication rate of ERCP in live demonstrations was not significantly different compared with controls (10.3% vs. 8.6%, P=0.473). However, the success rate was significantly lower in live demonstrations than in controls (94.1% vs. 97.5%, P=0.021). The success and complication rates of ERCP performed by local faculty, domestic visiting, and foreign visiting faculties were similar. CONCLUSIONS: Although the success rate of therapeutic ERCP performed during live demonstrations was lower than that of routine procedures, the overall complication rate did not significantly increase. ERCP performed by visiting endoscopists was as safe as that done by local faculty in live demonstrations.
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Colangiopancreatografia Retrógrada Endoscópica , Educação Médica Continuada , Gastroenterologia/educação , Colangiopancreatografia Retrógrada Endoscópica/efeitos adversos , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
The clinical isolation rate of multidrug-resistant or pan-resistant Acinetobacter baumannii (A. baumannii) is increasing, resulting that optional antibiotics are very limited in clinical practice. To deal with such a dilemma in treatment, the development of effective vaccines serves as a good strategy. Outer membrane proteins (Omp) often contain potential excellent vaccine antigens, and NCBI has published >300 Omp sequences of A. baumannii (including the duplicates). To accurately screen out the potential excellent antigen molecules from a large number of sequences, and avoid repetitive experimental processes is of great significance. In this study, we used the bioinformatics software to give extensive predictions of TolB protein. Results suggest it is a potential vaccine antigen. We then cloned the TolB gene fragments and confirmed it was highly conserved among the strains. Finally, we designed a good recombinant epitopes and conducted experimental verification. These findings provided grounds for animal immunology experiments in the future, and showed an orientation for the efficient development of A. baumannii vaccine.
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Infecções por Acinetobacter/prevenção & controle , Acinetobacter baumannii/genética , Proteínas da Membrana Bacteriana Externa/genética , Vacinas Bacterianas/imunologia , Biologia Computacional/métodos , Epitopos/imunologia , Animais , Antígenos de Bactérias/genética , Proteínas da Membrana Bacteriana Externa/imunologia , Sequência de Bases , Sequência Conservada , DNA Bacteriano , Epitopos/genética , Regulação Bacteriana da Expressão GênicaRESUMO
As a newly developed arc welding method, power ultrasound has been successfully introduced into arc and weld pool during ultrasonic wave-assisted arc welding process. The advanced process for molten metals can be realized by utilizing additional ultrasonic field. Under the action of the acoustic wave, the plasma arc as weld heat source is regulated and its characteristics make an obvious change. Compared with the conventional arc, the ultrasonic wave-assisted arc plasma is bound significantly and becomes brighter. To reveal the dependence of the acoustic binding force on acoustic field parameters, a two-dimensional acoustic field model for ultrasonic wave-assisted arc welding device is established. The influences of the radiator height, the central pore radius, the radiator radius, and curvature radius or depth of concave radiator surface are discussed using the boundary element method. Then the authors analyze the resonant mode by this relationship curve between acoustic radiation power and radiator height. Furthermore, the best acoustic binding ability is obtained by optimizing the geometric parameters of acoustic radiator. In addition, three concave radiator surfaces including spherical cap surface, paraboloid of revolution, and rotating single curved surface are investigated systematically. Finally, both the calculation and experiment suggest that, to obtain the best acoustic binding ability, the ultrasonic wave-assisted arc welding setup should be operated under the first resonant mode using a radiator with a spherical cap surface, a small central pore, a large section radius and an appropriate curvature radius.