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931.
932.
A number of mutations in the epidermal growth factor receptor (EGFR) have been identified that imparts resistance to anti-EGFR monoclonal antibodies (mAbs) in clinical and preclinical samples. Primary or acquired resistance to targeted therapy will eventually limit the clinical benefit of anticancer mAbs. The aim of the current study was to perform computational analysis to investigate the structural implications of the EGFR somatic mutations on its complexes with the four anti-EGFR mAbs (Cetuximab, Panitumumab, Necitumumab, and Matuzumab). Docking analysis and molecular dynamics (MD) simulations were performed to understand the plausible structural and dynamical implications caused by somatic mutations available in the Catalogue of Somatic Mutations in Cancer database on the EGFR and anti-EGFR mAbs. We found that EGFRS492R and EGFRV441I in complex with Cetuximab, EGFRR377S and EGFRS447Y in complex with Panitumumab, and EGFRV441I in complex with Necitumumab have a weakest binding affinity in comparison to EGFRWT in complex with the relevant mAb. Taken together with the results obtained from docking analysis and MD simulations, the present findings may suggest that, the S492R and V441I mutations confer resistance to Cetuximab, R377S and S447Y mutations mediate resistance to Panitumumab and finally, V441I mutation also confers resistance to Necitumumab.  相似文献   
933.
The effects of 1-[(E)-2-(2-methyl-4-nitrophenyl)diaz-1-enyl]pyrrolidine-2-carboxy lic acid (LY29) and diphenyliodonium chloride (DIC) on the degradation of protein to ammonia were determined in a mixed rumen microbial population taken from sheep on a grass hay-concentrate diet. Both compounds decreased NH3 production by inhibiting deamination of amino acids. LY29, but not DIC, inhibited growth of the high-activity ammonia-producing species, Clostridium aminophilum and Clostridium sticklandii.  相似文献   
934.
935.
Fresh harvested dates are perishable and there is a need for extending their shelf life while preserving their fresh like quality characteristics. This study evaluates three different freezing methods, namely cryogenic freezing (CF) using liquid nitrogen; individual quick freezing (IQF) and conventional slow freezing (CSF) in preserving the quality and stability of dates during frozen storage. Fresh dates were frozen utilizing the three methods. The produced frozen dates were frozen stored for nine months. The color values, textural parameters, and nutrition qualities were measured for fresh dates before freezing and for the frozen dates every three months during the frozen storage. The frozen dates’ color values were affected by the freezing method and the frozen storage period. There are substantial differences in the quality of the frozen fruits in favor of cryogenic freezing followed by individual quick freezing compared to the conventional slow freezing. The results revealed large disparity among the times of freezing of the three methods. The freezing time accounted to 10 min for CF, and around 80 min for IQF, and 1800 min for CSF method.  相似文献   
936.
BackgroundThe relevance of Cryptosporidium infections for the burden of childhood diarrhoea in endemic settings has been shown in recent years. This study describes Cryptosporidium subtypes among symptomatic and asymptomatic children in rural Ghana to analyse subtype-specific demographic, geographical, seasonal and clinical differences in order to inform appropriate control measures in endemic areas.Conclusions/SignificanceCryptosporidiosis is characterized by seasonal anthroponotic transmission of strains typically found in Sub-Saharan Africa. The infection mainly affects young infants, with vomiting and diarrhoea being one of the leading symptoms in C. parvum infection. Combining molecular typing and clinical data provides valuable information for physicians and is able to track sources of infections.  相似文献   
937.
Mung bean and tomato were in vitro selected from cotyledons on MS medium for improved tolerance to NaCl. The growth responses; the Na, K, proline and anthocyanin contents; and activities of phenylalanine ammonia lyase (PAL, EC 4.3.1.5), tyrosine ammonia lyase (TAL, EC 4.3.1) and chalcone isomerase (CI, EC 5.5.1.5) of the selected plants were characterised and compared with those of the original plants in relation to treatment with NaCl. The treatments significantly reduced fresh and dry weights of shoots and roots; the reduction was least pronounced in selected plants. Meanwhile, Na content was significantly increased; however, K was decreased, a trend that was obvious in original plants but withdrawn following in vitro selection with a consequent lowering in Na/K ratio. In addition, proline was greatly induced by NaCl; the induction was most pronounced in selected plants. Moreover, NaCl significantly increased anthocyanin and activities of PAL, TAL and CI in shoots and roots of both species; the increase was lesser in the selected than in the original plants. These findings indicated that selection of mung bean and tomato resulted in a recovery of growth, overproduction of proline and K and withdrawal of Na and secondary metabolism parameters relative to original plants pointing out to an improved tolerance to NaCl following in vitro selection.  相似文献   
938.
The reliability of the electrical distribution system is a contemporary research field due to diverse applications of electricity in everyday life and diverse industries. However a few research papers exist in literature. This paper proposes a methodology for assessing the reliability of 33/11 Kilovolt high-power stations based on average time between failures. The objective of this paper is to find the optimal fit for the failure data via time between failures. We determine the parameter estimation for all components of the station. We also estimate the reliability value of each component and the reliability value of the system as a whole. The best fitting distribution for the time between failures is a three parameter Dagum distribution with a scale parameter and shape parameters and . Our analysis reveals that the reliability value decreased by 38.2% in each 30 days. We believe that the current paper is the first to address this issue and its analysis. Thus, the results obtained in this research reflect its originality. We also suggest the practicality of using these results for power systems for both the maintenance of power systems models and preventive maintenance models.  相似文献   
939.
Visfatin levels have been reported to be abnormal in many types of cancers. However, epidemiological studies yielded inconsistent results. Therefore, a meta-analysis was performed to assess the association between circulating visfatin levels and cancer risk. A systematic search was conducted for relevant studies in health-related electronic databases up to March 2018. Data related to standard mean difference (SMD) and overall odds ratio (ORS) were collected and analyzed. Summary SMD and pooled OR with 95% CIs were calculated using a random-effect model. Funnel plot and Egger's linear regression test were conducted to examine the risk of publication bias. A total of 27 studies with 2,693 cases and 3,040 healthy controls were included in meta-analysis for pooling SMD analysis. The results of the meta-analysis showed a significant higher visfatin levels in patients with various cancers than in controls, with a pooled SMD of 0.88, 95% CI = 0.56–1.20, p = 0.000. In subgroup, metaregression, Galbraith plot, and sensitivity analysis showed no substantial difference among all the analyzed factors. Data from 14 studies were also used for pooling ORs analysis. Metaresults revealed that high visfatin levels were associated with cancer risk (OR = 1.24, 95% CI: 1.14–1.34, p = 0.000). No evidence of publication bias was observed for pooling ORs and SMD analysis. This meta-analysis indicated a significant association between high circulating visfatin levels and increased risk of various cancers. Visfatin may represent a potential biomarker for early detection of cancers who may benefit from preventive treatment.Note.  相似文献   
940.
Use of Hypericum perforatum L. has increased in the past few years due to the antidepressant and antiviral activities found in extracts of this plant. As a result of its potential as a pharmaceutical, a new system was developed for in vitro culture of this species. Leaf explants were inoculated onto MS medium supplemented with 2,4-dichlorophenoxyacetic acid (2,4-D, 0.45 or 4.5 μM) and 6-benzyladenine (BA, 0.44 or 4.4 μM) or kinetin (0.46 or 4.6 μM). Explants were cultivated under dark or light conditions to induce callus formation. Callus initiation was observed in all media evaluated and the highest cell proliferation was obtained from explants cultivated in the presence of 4.4 μM BA and 4.5 μM 2,4-D in the dark. Shoot induction was obtained from callus induced on 4.6 μM kinetin and 0.45 μM 2,4-D 6 weeks after transferring the callus to a MS medium supplemented with 4.4 μM BA. Roots were induced from shoots on full and half-strength MS media with or without indolebutyric acid (IBA, 4.9 μM) and the highest rooting frequencies were obtained on half-strength MS medium, regardless of the presence of IBA. Regenerated plants were easily acclimated in greenhouse conditions. The procedure reported here allows the micropropagation of H. perforatum in five months of culture and the proliferation of cell masses which could be used for studies on organic compounds of pharmaceutical interest. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   
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