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排序方式: 共有6485条查询结果,搜索用时 15 毫秒
41.
Camilla Rodrigues de Almeida Ribeiro Katrini Guidolini Martinelli Vinícius da Motta de Mello Natlia Spitz Oscar Rafael Carmo Araújo Lia Laura Lewis-Ximenez Natalia Motta Araujo Vanessa Salete de Paula 《Viruses》2022,14(7)
Several hepatitis B virus (HBV)-related factors, including the viral load, genotype, and genomic mutations, have been linked to the development of liver diseases. Therefore, in this study we aimed to investigate the influence of HBV genetic variability during acute and chronic infection phases. A real-time nested PCR was used to detect HBV DNA in all samples (acute, n = 22; chronic, n = 49). All samples were sequenced for phylogenetic and mutation analyses. Genotype A, sub-genotype A1, was the most common genotype in the study population. A total of 190 mutations were found in the pre-S/S gene area and the acute profile revealed a greater number of nucleotide mutations (p < 0.05). However, both profiles contained nucleotide mutations linked to immune escape and an increased risk of hepatocellular carcinomas (acute, A7T; chronic, A7Q). Furthermore, 17 amino acid substitutions were identified in the viral polymerase region, including the drug resistance mutations lamivudine and entecavir (rtL180M), with statistically significant differences between the mutant and wild type strains. Owing to the natural occurrence of these mutations, it is important to screen for resistance mutations before beginning therapy. 相似文献
42.
Szkaradek N Stachura K Waszkielewicz AM Cegła M Szneler E Marona H 《Acta poloniae pharmaceutica》2008,65(1):21-28
A series of some derivatives of 2-xanthone was synthesized and evaluated for their activity against M. tuberculosis in primary and/or secondary microbiological assays. The cytotoxic activity of some compounds was also evaluated. The most active compounds were: [I] 2-(2-(4-(2-(4-chloro-3-methylphenoxy)ethyl)piperazin-1-yl)ethoxy)-9H-xanthen-9-one, [III] 2-((4-(2-(4-chlor-3-methylphenoxy)ethyl)piperazin-1-yl)methyl)-9H-xanthen-9-one dihydrochloride and [XVIII] ethyl 4-(2-hydroxy-3-(9-oxo-9H-xanthen-2-yloxy)propyl) piperazine-1-carboxylate, which displayed 98%, 98% and 94% inhibition of M. tuberculosis growth, respectively. Furthermore, compounds III and XVIII revealed their cytotoxic activity (SI < 1). Other structures varied greatly in their anti M. tuberculosis activity, however, several trends in their structure in relation to their antituberculous activity have been observed. 相似文献
43.
The global use of petroleum hydrocarbons as raw materials and an energy source in industry results in serious environmental, health, and ecological problems. Consequently, there is growing interest in the development of technologies for the rehabilitation of contaminated areas. This study was undertaken in order to determine the effect of different phytostabilising materials (compost, bentonite, and CaO) on the trace element content in soil contaminated with unleaded petroleum 95 (0, 2.5, 5, and 10 cm3 kg−1 of soil). The doses of petroleum applied to the soil were based on the previously conducted preliminary experiment. The highest petroleum dose (10 cm3 kg−1 of soil) significantly reduced the chromium, zinc, and cobalt contents in the soil. Petroleum increased the cadmium, lead, nickel, and copper contents in the soil. The materials used for phytostabilisation (compost, bentonite, calcium oxide) had a significant effect on the trace element content in the soil. The application of mineral materials (bentonite and calcium oxide) was more effective than the application of compost, compared to the control series (without soil amendments) as they reduced the contents of cadmium, chromium, nickel, and cobalt in the soil to the greatest extent. The reduction effect of bentonite and calcium oxide on the content of these trace elements in the soil was stronger than compost. 相似文献
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Maura Massimino Douglas B. Evans Marta Podda Claudio Spinelli Paola Collini Natalia Pizzi Archie Bleyer 《Pediatric blood & cancer》2018,65(8)
In adolescents and young adults, thyroid cancer accounts for 13% of all invasive neoplasms, being three times more frequent in females, but overdiagnosis and overtreatment are common. There are two therapeutic approaches, one radical and no longer preferred in all instances, and the other conservative. Permanent complications of surgery and metabolic irradiation can affect quality of life and carry an economic burden. The overall survival rate approaches 100% for patients with differentiated thyroid cancer regardless of the extent of treatment. Medullary thyroid carcinoma is a very different entity, occurring most frequently in the context of hereditary tumor susceptibility syndromes. 相似文献
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Garcia Melawhy L. Gatdula Natalia Bonilla Erika Frank Gail C. Bird Mara Rascón Mayra S. Rios-Ellis Britt 《Maternal and child health journal》2019,23(6):802-810
Maternal and Child Health Journal - Introduction Hispanics/Latinos are disproportionately affected by obesity in the U.S. Multiple factors place Hispanic/Latino children at risk for overweight,... 相似文献
50.
Maciej Tabaszewski Pawe Twardowski Martyna Wiciak-Pikua Natalia Znojkiewicz Agata Felusiak-Czyryca Jakub Czyycki 《Materials》2022,15(12)
The dynamic development of new technologies enables the optimal computer technique choice to improve the required quality in today’s manufacturing industries. One of the methods of improving the determining process is machine learning. This paper compares different intelligent system methods to identify the tool wear during the turning of gray cast-iron EN-GJL-250 using carbide cutting inserts. During these studies, the experimental investigation was conducted with three various cutting speeds vc (216, 314, and 433 m/min) and the exact value of depth of cut ap and federate f. Furthermore, based on the vibration acceleration signals, appropriate measures were developed that were correlated with the tool condition. In this work, machine learning methods were used to predict tool condition; therefore, two tool classes were proposed, namely usable and unsuitable, and tool corner wear VBc = 0.3 mm was assumed as a wear criterium. The diagnostic measures based on acceleration vibration signals were selected as input to the models. Additionally, the assessment of significant features in the division into usable and unsuitable class was caried out. Finally, this study evaluated chosen methods (classification and regression tree, induced fuzzy rules, and artificial neural network) and selected the most effective model. 相似文献