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1.
The germline carrier of the BRCA1 pathogenic mutation has been well proven to confer an increased risk of breast and ovarian cancer. Despite BRCA1 biallelic pathogenic mutations being extremely rare, they have been reported to be embryonically lethal or to cause Fanconi anemia (FA). Here we describe a patient who was a 48-year-old female identified with biallelic pathogenic mutations of the BRCA1 gene, with no or very subtle FA-features. She was diagnosed with ovarian cancer and breast cancer at the ages of 43 and 44 and had a strong family history of breast and gynecological cancers.  相似文献   
2.
Flesh colour, which is affected by cultivars and browning, can largely impact consumer acceptance in fresh-cut apples. The study profiled phenolic metabolites from apple flesh of twenty-three cultivars by widely targeted metabolomics. Comparison among white- and yellow-fleshed cultivars showed fifteen phenolics, mainly quercetin 3-O-glucoside, hyperoside, hesperetin 5-O-glucoside and cymaroside, in white-fleshed apples were significantly higher than those in yellow-fleshed apples. It may indicate a metabolite basis of yellow and white flesh colour, and better potential nutrition in white-fleshed apples. In addition, ten phenolic metabolites including five cyanidin glycosides showed significant differences between the highest and the lowest browning groups, indicating them may be crucial in browning of fresh-cut apple. This work elucidates the differences of phenolic profiles among apple cultivars with different flesh colour and provides useful data to evaluate the suitability of apple for fresh-cut processing.  相似文献   
3.
A series of ZnxNiyCrOm±δ catalysts were synthesized via a typical co-precipitation method, in which Zn-Cr layered double hydroxides (LDHs) were found and Ni-Zn intermetallic compound (IMC) was formed after reduction in hydrogen. During auto-thermal reforming (ATR) of acetic acid (HAc), the Ni-Zn IMC was transformed into Ni/(amorphous-ZnO)-ZnCr2O4 species with uniformed distribution and appropriate interaction within these Ni-Zn-Cr-O species; besides, the adsorbed oxygen promoted the activation and transfer of oxygen species; therefore, deactivation by oxidation, sintering and coking was inhibited. And the optimized Zn2.37Ni0.63CrO4.5±δ catalyst presented high activity and stability in a 45-h ATR test with HAc conversion near 100% and hydrogen yield at 2.7 mol-H2/mol-HAc, showing potential for hydrogen production via ATR of HAc.  相似文献   
4.
随着煤矿向深部发展,矿井动力灾害既表现出冲击地压的部分特征,又表现出冒顶的部分特征。2种典型的灾害打破以往冒顶与冲击地压的发生具有一种互为逆向性的认知规律,在深部高应力煤巷,特别是留顶煤巷道中出现了相互诱导、复合发生的新灾害类型。在总结山东、山西和新疆矿区典型巷道冲击致顶板(顶煤)动力灾害特征的基础上,提出了深部巷道冲击地压与冒顶复合灾害的概念、机理与分类,指出复合灾害机理关键点在于揭示巷道整体系统和破碎区子系统的稳定原理及其2者间的相互影响。建立了巷道发生复合灾害的力学模型,根据扰动响应失稳判据,提出并得到了巷道发生复合灾害的临界应力Pcr、临界软化区半径ρcr和最大容许采扰应力增量σmax,厘清了灾害发生的主控因素,分析了煤岩冲击倾向指数K、支护强度ps、巷道半径ρ0、煤岩强度σc等对灾害发生的影响规律,同时阐明了围岩塑性软化、破碎深度随地应力增加的发育规律。研究结果表明,破碎发育巷道的动力失稳主体为弹性区、软化区与破碎区构成的不稳定系统,垮落主体为破碎区;稳定的破碎区提升了巷道冲击启动临界值,使其启动难度增大,但破碎区的发育又易引起顶煤垮落;巷道稳定支护是解决复合灾害的关键,科学合理支护既能有效调控围岩破碎防冒,又能提升冲击启动临界值。通过理论研究,揭示了巷道冲击地压与冒顶复合灾害的发生机理,阐明了巷道软化与破碎区及其稳控支护对深部破碎发育巷道动力灾害防治的重要性。  相似文献   
5.
This study examines the extraction of beryllium and aluminium from a Nigerian beryl ore using Cyanex®272 in kerosene from an aqueous sulphate pregnant solution. Parameters such as extractant concentration and equilibrium pH that dictates the extraction yield were studied. Under the following conditions: temperature 27?±?2°C, phase ratio 1?1, about 45.50 and 46.76% of beryllium and aluminium were extracted by 0.15?mol?L?1 Cyanex®272 concentration within 30?min. However, the extraction yield of beryllium and aluminium was increased to 91.68% and 97.89% at equilibrium pH of 3 and 4, respectively, for beryllium and aluminium at 27?±?2°C. A 0.05?mol?L?1 H2SO4 solution was found to be adequate for the stripping of about 99.00% Be and 95.40% Al from the loaded organic phase. The pure solutions containing metal ions were accordingly beneficiated to obtain beryllium and aluminium compounds of industrial values.  相似文献   
6.
Partitioning to surfaces is an important sink for volatile organic compounds (VOCs) indoors, but the mechanisms are not well understood or quantified. Here, a mass spectrometer was coupled to a portable surface reactor and a flow tube to measure partitioning of VOCs into paint films coated onto glass or wallboard, and their subsequent diffusion. A model was developed to extract values of the effective absorbing organic mass concentration of the film, Cw, which is a measure of absorption capacity, and VOC diffusion coefficients, Df, from VOC time profiles measured during film passivation and depassivation. Values of Cw agreed well with the value estimated from the paint film mass and flow tube air volume, and Df values (also measured using attenuated total reflectance-Fourier transform infrared spectroscopy) correlated well with VOC vapor saturation concentrations, C*, estimated using a group contribution method. The value of these relationships for estimating key parameters that control VOC partitioning into paint and the fate of VOCs indoors was demonstrated using a house model, which indicated that >50% of VOCs with C* ≤108 μg/m3 (C* of octane, hexanone, and propanol) that contacted a paint film of typical thickness fully permeated the film regardless of emission duration.  相似文献   
7.
World population growth and aging are posing unprecedented challenges in sustaining the health of 9.1 billion people that will be occupying the planet by 2050. Although noncommunicable diseases such as cardiovascular and neurodegenerative diseases, cancer, and diabetes are among the top 10 global causes of death, they can be prevented by risk factor reduction, early detection, and adequate treatment. Since a healthy diet along with dietary supplementation could play an important role to reduce morbidity and cut off its associated health care costs, research in the food and nutrition area is required to find solutions to global challenges affecting health. As a result of the healthy living trend, dietary supplements category is growing fast, leading to an urgent need for dietitians, physicians, and policy makers to broaden the scientific evidence on the efficacy and safety of a wide range of active ingredients. Coenzyme Q10 (CoQ10), as the third most consumed dietary supplement, and as a potential candidate for the treatment of various noncommunicable diseases that are among the global top 10 causes of death, has gained interest over years. Scientific evidence regarding mainly CoQ10 efficacy and safety, as well as formulation challenges, is addressed in this review.  相似文献   
8.
罗通通  孙玲 《中国塑料》2020,34(11):66-72
以聚乳酸(PLA)和聚己二酸/对苯二甲酸丁二酯(PBAT)为基体,杨木粉(WF)为填充增强材料,使用混炼机熔融共混制备PLA/PBAT/WF复合材料,采用熔融沉积成型(FDM)技术制备标准实验试样,通过扫描电子显微镜、红外光谱分析、旋转流变测试以及力学试验等方法,研究不同含量的硅烷偶联剂KH550对PLA/PBAT共混物以及PLA/PBAT/WF的相容性、流变性及力学性能的影响。结果表明,在偶联剂用量为3 %(质量分数,下同)时,拉伸强度提高了136 %;偶联剂KH550与 PLA和PBAT共价键偶联生成接枝聚合物,二者相容性得到提高;同时偶联剂与WF表面羟基发生缩聚反应有效的改善了其与PLA/PBAT的基体相容性,PLA/PBAT/WF复合材料的FDM的制件力学性能得到较大提升;复合材料的黏度随偶联剂含量的增加呈下降的趋势,含量为3 %时线材的综合打印性能及制品质量最佳。  相似文献   
9.
10.
梁星星  张永旺  王斌  朱保宁  曹辉 《化工进展》2020,39(6):2487-2494
生物质热电厂焚烧废弃物的主要成分是草木灰,其产生量大、密度小。大量草木灰不经处理会造成环境污染问题。本文首先分析草木灰的化学成分,确定草木灰的肥料特征,通过添加NH4H2PO4使草木灰的pH达到国家复合肥的相关标准。选用聚天冬氨酸(30%水溶液)作为复合肥的黏结剂,应用于草木灰复合肥的成形造粒,以增加其抗压强度和肥效。研究不同烘干时间、烘干温度、聚天冬氨酸添加量对草木灰复合肥抗压强度的影响规律,通过分析植物的形态及生理指标,进而研究草木灰复合肥的肥效。结果表明:最佳烘干条件为10h、140℃,聚天冬氨酸对草木灰的抗压强度有明显的增强作用,并且草木灰与聚天冬氨酸的复配比为6g∶1mL时肥效最好。此方法解决了元素循环中断、草木灰环境污染,在运输过程中草木灰复合肥易碎,纯草木灰肥效低等问题。  相似文献   
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