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91.
Bocaviruses are associated with many human infectious diseases, such as respiratory tract infections, gastroenteritis, and hepatitis. Rats are known to be reservoirs of bocaviruses, including rodent bocavirus and rat bocavirus. Recently, ungulate bocaparvovirus 4, a known porcine bocavirus, has also been found in rats. Thus, investigating bocaviruses in rats is important for determining the origin of the viruses and preventing and controlling their transmission. To the best of our knowledge, no study to date has investigated bocaviruses in the livers of rats. In this report, a total of 624 rats were trapped in southern China between 2014 and 2017. Liver and serum samples from rats were tested for the prevalence of bocaviruses using PCR. Sequences related to ungulate bocaparvovirus 4 and rodent bocavirus were detected in both liver and serum samples. Interestingly, the prevalence of ungulate bocaparvovirus 4 (reference strain:KJ622366.1) was higher than that of rodent bocavirus (reference strain:KY927868.1) in both liver (2.24% and 0.64%, respectively) and serum samples (2.19% and 0.44%, respectively). The NS1 regions of ungulate bocaparvovirus 4 and rodent bocavirus related sequences displayed over 84% and 88% identity at the nucleic acid and amino acid levels, respectively. Furthermore, these sequences had similar genomic structure, genomic features, and codon usage bias, and shared a common ancestor. These viruses also displayed greater adaptability to rats than pigs. Our results suggested that ungulate bocaparvovirus 4 and rodent bocavirus may originate from rats and may be different genotypes of the same bocavirus species.  相似文献   
92.
Rice is the most important crop for the majority of population across the world with sensitive behavior toward heavy metals such as chromium (Cr) in polluted regions. Although, there is no information on the Cr resistance phenotyping in rice. Herein, two different groups of rice cultivars (normal, and hybrid) were used, each group with 14 different rice cultivars. Firstly, seed germination analysis was conducted by evaluating various seed germination indices to identify the rice cultivars with greatest seed germination vigor. Furthermore, exposure of chromium (Cr) toxicity to 28 different rice varieties (NV1-NV14, HV1-HV14) caused noticeable plant biomass reduction. Subsequently, NV2, NV6, NV10, NV12, NV13 (normal type), HV1, HV4, HV8, and HV9 (hybrid types) were pragmatic as moderately sensitive varieties, while NV3, NV4, NV9, and NV14 (normal type), HV3, HV6, HV7, and HV13 were observed as moderately tolerant. Although, NV7, and HV10 were ranked most sensitive cultivars, and NV11, and HV14 were considered as most tolerant varieties as compared to the other rice (both groups) genotypes. Afterward, Cr induced reduction in chlorophyll pigments were significantly lesser in HV14 relative to NV11, NV7, and especially HV10, and as a result HV14 modulated the total soluble sugar level as well as reduced ROS accumulation, and MDA contents production by stimulating the antioxidant defense mechanism conspicuously which further reduced the electrolyte leakage as well. Our outcomes provide support to explore the Cr tolerance mechanism in cereal crops as well as knowledge about rice breeding with increased tolerance against Cr stress.  相似文献   
93.
This article describes a study where the recovery of nasopharyngeal cancer (NPC) patients was traced by trace elements (TEs) in hair of these patients. These patients whose concentrations of TEs in hair were studied are volunteers who were divided into three groups B, C, and D. Group B was made up of volunteers who had just been diagnosed as having NPC, group C and group D were made up of volunteers who had been diagnosed as having NPC after 3 and 6 mo, respectively, of treatment. For comparison, a control group, namely group A, which was made up of volunteers from healthy persons was added to this study. By implementation of statistic pattern recognition methods, it has been found that the concentrations of TEs in hair can remarkably reflect different recovery phases of NPC patients.  相似文献   
94.
Fibronectin (FN) is the foremost proliferation‐associated extracellular matrix component promoting cell adhesion, migration, and survival. We examined the effect of FN on cell proliferation and the related signaling pathways in mouse embryonic stem (ES) cells. FN increased integrin β1, Src, focal adhesion kinase (FAK), and caveolin‐1 phosphorylation levels in a time‐dependent manner. Phosphorylation of Src, FAK, and caveolin‐1 was attenuated by integrin β1 neutralizing antibody. Integrin β1, Src, and FAK coimmunoprecipitated with caveolin‐1 in the presence of FN. In addition, FN increased RhoA and Rho kinase activation, which were completely blocked by PP2, FAK small interfering RNA (siRNA), caveolin‐1 siRNA, or the caveolar disruptor methyl‐β‐cyclodextrin (MβCD). FN also increased phosphorylation of Akt and ERK 1/2, which were significantly blocked by either FAK siRNA, caveolin‐1 siRNA, MβCD, GGTI‐286 (RhoA inhibitor), or Y‐27632 (Rho kinase inhibitor). FN‐induced increase of protooncogenes (c‐fos, c‐myc, and c‐Jun) and cell‐cycle regulatory proteins (cyclin D1/CDK4 and cyclin E/CDK2) expression levels were attenuated by FAK siRNA or caveolin‐1 siRNA. Furthermore, inhibition of each pathway such as integrin β1, Src, FAK, caveolin‐1, RhoA, Akt, and ERK 1/2 blocked FN‐induced [3H]‐thymidine incorporation. We conclude that FN stimulates mouse ES cell proliferation via RhoA‐PI3K/Akt‐ERK 1/2 pathway through caveolin‐1 phosphorylation. J. Cell. Physiol. 226: 267–275, 2010. © 2010 Wiley‐Liss, Inc.  相似文献   
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97.
Structural features of the rice chromosome 4 centromere   总被引:23,自引:0,他引:23       下载免费PDF全文
Zhang Y  Huang Y  Zhang L  Li Y  Lu T  Lu Y  Feng Q  Zhao Q  Cheng Z  Xue Y  Wing RA  Han B 《Nucleic acids research》2004,32(6):2023-2030
  相似文献   
98.
叶食性灵长类食物选择受食物营养及单宁等次生代谢产物影响,为了探讨单宁对黑白仰鼻猴食物选择的影响,通过磷钼酸-钨酸钠 (F-D) 比色法测定了拉沙山黑白仰鼻猴群 (Rhinopithecus bieti) 2010年4月 - 2012年3月间的食用植物 (192种) 和非食用植物 (188种) 单宁含量。结果表明,黑白仰鼻群全年食用植物中单宁含量低于非食用植物;春季食用植物中单宁含量高于其他季节,而其他季节无差异;不同取食部位单宁由高到低依次为芽、花、叶、果和地衣;不同季节,不同取食部位单宁有差异,春季芽的单宁含量最高,夏秋季果实单宁含量最高,冬季叶单宁含量最高;不同月份,食物单宁也不同,3月食用植物中单宁最高 (8.36% ± 6.22%),2月最低 (1.28% ± 1.19%)。因此,黑白仰鼻猴根据环境食物种类和供给时空特征,可能采取了从高蛋白纤维比/高单宁到低蛋白纤维比/低单宁连续谱觅食策略。  相似文献   
99.
Evaluation of litterfall production is important for understanding nutrient cycling, forest growth, successional pathways, and interactions with environmental variables in forest ecosystems. Litterfall was intensively studied during the period of 1982–2001 in two subtropical monsoon vegetation gradients in the Dinghushan Biosphere Reserve, Guangdong Province, China. The two gradients include: (1) a successional gradient composed of pine forest (PF), mixed pine and broadleaved forest (MF) and monsoon evergreen broadleaved forest (BF), and (2) an altitudinal gradient composed of Baiyunci ravine rain forest (BRF), Qingyunci ravine rain forest (QRF), BF and mountainous evergreen broadleaved forest (MMF). Mean annual litterfall production was 356, 861 and 849 g m−2 for PF, MF and BF of the successional gradient, and 1016, 1061, 849 and 489 g m−2 for BRF, QRF, BF and MMF of the altitudinal gradient, respectively. As expected, mean annual litterfall of the pioneer forest PF was the lowest, but rapidly increased over the observation period while those in other forests were relatively stable, confirming that forest litterfall production is closely related to successional stages and growth patterns. Leaf proportions of total litterfall in PF, MF, BF, BRF, QRF and MMF were 76.4%, 68.4%, 56.8%, 55.7%, 57.6% and 69.2%, respectively, which were consistent with the results from studies in other evergreen broadleaved forests. Our analysis on litterfall monthly distributions indicated that litterfall production was much higher during the period of April to September compared to other months for all studied forest types. Although there were significant impacts of some climate variables (maximum and effective temperatures) on litterfall production in some of the studied forests, the mechanisms of how climate factors (temperature and rainfall) interactively affect litterfall await further study.  相似文献   
100.
本文所说中国南部石灰岩地区主要指广西、云南、贵州三省的石灰岩地区,这一地区以其植物的多样性和岩溶特有性而闻名。本文对这一地区的植被和植物保护现状、自然屎护区状况、植物濒危原因筹进行了初步考察和研究。  相似文献   
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