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41.
Heavy metals in some Chinese herbal plants   总被引:1,自引:0,他引:1  
The concentrations of nine heavy metals, cadmium, cobalt, copper, iron, manganese, nickel, lead, zinc and mercury in 42 Chinese herbal medicinal plants were determined. Generally, all the samples studied had, relative to the other trace metals, higher concentrations of iron, manganese, and zinc. The concentration range of the metals determined was comparable to that in many of the East Asian vegetables and fruits. A few samples were found to contain relatively higher concentrations of the toxic metals such as cadmium, lead, and mercury. This was probably caused by contamination during air-drying and preservation.  相似文献   
42.
中国瑟姬小蜂及二新种的描述(膜翅目:姬小蜂科)   总被引:1,自引:0,他引:1  
瑟姬小蜂属Cirrospilus昆虫是鳞翅目,双翅目,特别是细蛾,潜叶蛾,潜叶蝇类及其他荫蔽性小幼虫或蛹的重要寄生蜂,有些也能重寄生于绒茧蜂和蜘蛛卵等中,本文除二新种描述外,还收入瑟姬小蜂六种。一并列于检索表中。  相似文献   
43.
A study of the research on postpartum mother-infant bonding shows that results from poorly constructed research programs were published in major journals and became a part of hospital policy because the bonding concept was politically useful in the struggle between advocates of natural childbirth and managers of the medical model of birth. The concept was also uncritically accepted because it was consistent with a longstanding ideology of motherhood that sees women as the prime architects of their children’s personalities. Diane Eyer earned her Ph.D. in developmental psychology from the University of Pennsylvania. She is currently writing a book on the ways in which the concepts of bonding and attachment have affected our understanding of appropriate early childcare.  相似文献   
44.
Noctiluca scintillans is one of the most common harmful algal species and widely known due to its bioluminescence. In this study, the spatial distribution, seasonal variations, and long-term trends of N. scintillans blooms in China and the related drivers were analyzed and discussed. From 1933 to 2020, a total of 265 events of N. scintillans blooms were recorded in Chinese coastal waters, with a total duration of 1052 days. The first N. scintillans bloom occurred in Zhejiang in 1933, and only three events were recorded before 1980. From 1981 to 2020, N. scintillans caused harmful algal blooms (HABs) almost every year, both the average duration and the proportion of multiphase HABs showed an increasing trend. 1986–1992, 2002–2004, and 2009–2016 were the three peak periods with a frequency of no less than five events of N. scintillans blooms per year. In terms of spatial distribution, N. scintillans blooms spread from the Southeast China Sea to the Bohai Sea after 2000, Guangdong, Fujian, and Hebei were the three provinces with the highest numbers of recorded events of N. scintillans blooms. Moreover, 86.8% of the events of N. scintillans blooms occurred in spring (March, April, and May) and summer (June, July, and August). Among environmental factors, the dissolved inorganic phosphate, dissolved silicate and chemical oxygen demand were significantly correlated with the cell density of N. scintillans during N. scintillans blooms, and most of N. scintillans blooms were recorded in the temperature range of 18.0–25.0°C. Precipitation, hydrodynamics, water temperature, and food availability might be the main factors affecting the spatial–temporal distribution of N. scintillans blooms along the Chinese coast.  相似文献   
45.
Zanthoxylum armatum and Zanthoxylum bungeanum, known as ‘Chinese pepper’, are distinguished by their extraordinary complex genomes, phenotypic innovation of adaptive evolution and species-special metabolites. Here, we report reference-grade genomes of Z. armatum and Z. bungeanum. Using high coverage sequence data and comprehensive assembly strategies, we derived 66 pseudochromosomes comprising 33 homologous phased groups of two subgenomes, including autotetraploid Z. armatum. The genomic rearrangements and two whole-genome duplications created large (~4.5 Gb) complex genomes with a high ratio of repetitive sequences (>82%) and high chromosome number (2n = 4x = 132). Further analysis of the high-quality genomes shed lights on the genomic basis of involutional reproduction, allomones biosynthesis and adaptive evolution in Chinese pepper, revealing a high consistent relationship between genomic evolution, environmental factors and phenotypic innovation. Our study provides genomic resources and new insights for investigating diversification and phenotypic innovation in Chinese pepper, with broader implications for the protection of plants under severe environmental changes.  相似文献   
46.
Na+/H+逆向转运蛋白(Na+/H+antiporter,NHX)基因家族在植物响应盐胁迫中发挥重要作用。本研究鉴定了大白菜NHX基因家族成员,并分析了大白菜NHX基因(Brassica rapa ssp.Pekinensis NHX,BrNHXs)响应高温、低温、干旱和盐胁迫等非生物逆境的表达模式。结果表明,在大白菜中共鉴定到9个NHX基因家族成员,分布在大白菜的6条染色体上,其氨基酸数目在513–1154 aa之间,相对分子量集中在56804.22–127856.66 kDa,等电点位于5.35–7.68之间。该基因家族成员主要存在于液泡中,基因结构完整,外显子的数目介于11–22之间。大白菜NHX基因家族编码的蛋白质二级结构都具有α-螺旋、β-转角和不规则卷曲结构,其中α-螺旋发生频率较高。实时荧光定量PCR(quantitative real-time PCR,qRT-PCR)分析显示,该基因家族成员在高温、低温、干旱和盐胁迫下均有不同程度地响应,且在不同时间表达差异显著。以BrNHX02和BrNHX09对这4种胁迫的响应最为显著,表达量在处理72 h时均显著上调,可作为候选基因进一步验证其功能。  相似文献   
47.
48.
Efforts to leverage clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR/Cas9) for targeted genomic modifications in mammalian cells are limited by low efficiencies and heterogeneous outcomes. To aid method optimization, we developed an all-in-one reporter system, including a novel superfolder orange fluorescent protein (sfOrange), to simultaneously quantify gene disruption, site-specific integration (SSI), and random integration (RI). SSI strategies that utilize different donor plasmid formats and Cas9 nuclease variants were evaluated for targeting accuracy and efficiency in Chinese hamster ovary cells. Double-cut and double-nick donor formats significantly improved targeting accuracy by 2.3–8.3-fold and 19–22-fold, respectively, compared to standard circular donors. Notably, Cas9-mediated donor linearization was associated with increased RI events, whereas donor nicking minimized RI without sacrificing SSI efficiency and avoided low-fidelity outcomes. A screen of 10 molecules that modulate the major mammalian DNA repair pathways identified two inhibitors that further enhance targeting accuracy and efficiency to achieve SSI in 25% of transfected cells without selection. The optimized methods integrated transgene expression cassettes with 96% efficiency at a single locus and with 53%–55% efficiency at two loci simultaneously in selected clones. The CRISPR-based tools and methods developed here could inform the use of CRISPR/Cas9 in mammalian cell lines, accelerate mammalian cell line engineering, and support advanced recombinant protein production applications.  相似文献   
49.
Although Platycodon grandiflorum (Jacq.) A.DC. is a renowned medicine food homology plant, reports of excessive cadmium (Cd) levels are common, which affects its safety for clinical use and food consumption. To enable its Cd levels to be regulated or reduced, it is necessary to first elucidate the mechanism of Cd uptake and accumulation in the plant, in addition to its detoxification mechanisms. This present study used inductively couple plasma-mass-spectrometry to analyze the subcellular distribution and chemical forms of Cd in different tissues of P. grandiflorum. The experimental results showed that Cd was mainly accumulated in the roots [predominantly in the cell wall (50.96%–61.42%)], and it was found primarily in hypomobile and hypotoxic forms. The proportion of Cd in the soluble fraction increased after Cd exposure, and the proportion of insoluble phosphate Cd and oxalate Cd increased in roots and leaves, with a higher increase in oxalate Cd. Therefore, it is likely that root retention mechanisms, cell wall deposition, vacuole sequestration, and the formation of low mobility and low toxicity forms are tolerance strategies for Cd detoxification used by P. grandiflorum. The results of this study provide a theoretical grounding for the study of Cd accumulation and detoxification mechanisms in P. grandiflorum, and they can be used as a reference for developing Cd limits and standards for other medicine food homology plants.  相似文献   
50.
ObjectiveGastric carcinoma (GC) has received extensive attention due to its complex pathogenesis. Studies have shown that the expression of Trefoil factor 1 (TFF1) and Partner and localiser of BRCA2 (PALB2) genes promotes the occurrence of GC. Therefore, we investigated whether TFF1 and PALB2 gene polymorphisms are associated with GC risk in the Chinese Han population.MethodsA total of 509 GC cases and 505 controls were recruited, and single nucleotide polymorphisms (SNPs) of TFF1 and PALB2 in these subjects were genotyped. The association between each candidate polymorphism and GC risk was assessed by calculating odds ratios (ORs) and 95% confidence intervals (CIs). The visualization of gene-gene interactions and functional enrichment analysis were then performed using Cytoscape software and the R package “cluster profile”.ResultsThe TFF1 rs2156310 polymorphism significantly reduced the predisposition to GC in people under 60 years of age (AA vs. AG - GG, OR = 0.58, 95% CI = 0.35–0.97, p = 0.036). The gender-stratified analysis found that PALB2 rs513313 was significantly associated with the risk of GC in males (CT vs. TT, OR = 1.51, 95% CI = 1.06–2.15, p = 0.022). Besides, PALB2 rs249954 significantly reduced the susceptibility to GC in females (AA vs GG, OR = 0.42, 95% CI = 0.19–0.94, p = 0.034).ConclusionOur results revealed that TFF1 and PALB2 gene polymorphisms were correlated with the genetic susceptibility to GC, providing certain data support for researchers to further study the mechanism of GC.  相似文献   
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