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排序方式: 共有1209条查询结果,搜索用时 15 毫秒
1.
科学合理地种植中草药是解决中药资源紧缺、保障中药质量的根本方法。中草药品质受种子种苗、种植措施、土壤状况等多种因素影响,各影响因素对中草药品质产生不同的作用,但迄今为止并没有通过调控中草药种植因素分析中药材品质的模型和方法。因此,本研究通过文献调研结合专家种植经验,综合分析影响中草药种植指标的复杂因素,以提高中药材品质为目标,基于图数据库的方法构建影响不同中草药种植品质的知识图谱,探讨中草药种植因素与指标之间的关系,通过调节影响中药材品质的因素,为中草药种植以及提高中药品质提供依据。  相似文献   
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Tick‐borne diseases (TBDs) have a large impact on animal health and the livelihood of livestock owners, particularly in developing countries. Although climatic and ecological conditions in Pakistan may favour the transmission of tick‐borne pathogens (TBPs), only a few systematic studies have been carried out on TBPs and the diseases that they cause in this country. To improve our understanding of the distribution of TBPs, 3,807 ticks were collected from ruminants (n = 369) on 108 livestock farms (semi‐arid zone = 36, arid zone = 72) in Punjab Province. After morphological identification ticks were pooled into 405 pools (Hyalomma anatolicum = 300, Rhipicephalus microplus = 89, Hyalomma dromedarii = 9, Rhipicephalus turanicus = 7) based on their species, locality of collection, and the host. DNA from each pool was screened by a Reverse Line Blot (RLB) hybridization assay for the presence of Anaplasma, Ehrlichia, Rickettsia, Babesia, and Theileria species. DNA from at least one TBP was found in 142 (35.1%) pools. Among the positive pools, 91 (64.1%) had a mixed infection with two or more TBPs, whereas 51 (35.9%) pools were infected with a single TBP. The detected pathogens not only included species that were known to be endemic in Pakistan, such as Theileria annulata (6.7%), Theileria orientalis (3.5%), Anaplasma marginale (5.7%), Anaplasma centrale (2.7%), Anaplasma ovis (1.5%), Babesia bigemina (0.7%), and Babesia bovis (0.2%), but also several TBPs that had not been reported to occur in Pakistan before. This included Ehrlichia minasensis (3.2%), an Anaplasma platys‐like organism (1.2%), Babesia occultans (0.2%), and Rickettsia massiliae (0.2%), as well as two previously uncharacterized species: Ehrlichia sp. Multan (18.0%) and Anaplasma sp. (BL099‐6) (2.22%). The pathogenicity of these novel species remains to be examined. This study shows that a much broader spectrum of TBPs is present in Pakistan than previously thought, including several zoonotic pathogens.  相似文献   
3.
The dietary specialist fruit fly Drosophila sechellia has evolved resistance to the secondary defence compounds produced by the fruit of its host plant, Morinda citrifolia. The primary chemicals that contribute to lethality of M. citrifolia are the medium‐chain fatty acids octanoic acid (OA) and hexanoic acid. At least five genomic regions contribute to this adaptation in D. sechellia and whereas the fine‐mapped major effect locus for OA resistance on chromosome 3R has been thoroughly analysed, the remaining four genomic regions that contribute to toxin resistance remain uncharacterized. To begin to identify the genetic basis of toxin resistance in this species, we removed the function of well‐known detoxification gene families to determine whether they contribute to toxin resistance. Previous work found that evolution of cytochrome P450 enzymatic activity or expression is not responsible for the OA resistance in D. sechellia. Here, we tested the role of the two other major detoxification gene families in resistance to Morinda fruit toxins – glutathione‐S‐transferases and esterases – through the use of the pesticide synergists diethyl maleate and tribufos that inhibit the function of these gene families. This work suggests that one or more esterase(s) contribute to evolved OA resistance in D. sechellia.  相似文献   
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目的探讨附着龈重建应用于口腔种植修复中的临床效果。方法将本院于2016年10月-2018年10月期间收治的行口腔种植修复治疗的附着龈缺失患者82例作为研究资料,依据治疗方案分组,对照组为传统修复治疗方案,观察组采用附着龈重建治疗修复方案,各41例,评价两组术后不同阶段附着龈宽度、龈缘外形及附着点重建改善效果,并评价患者评价治疗满意度。结果术后3个月观察组患者附着龈宽度改善Ⅲ级率56.10%明显高于对照组0.00%,龈缘外形与附着点重建Ⅲ级率60.98%明显高于对照组0.00%(P <0.05);术后6个月观察组患者附着龈宽度改善Ⅲ级率75.61%明显高于对照组0.00%,龈缘外形与附着点重建Ⅲ级率73.17%明显高于对照组0.00%(P <0.05);观察组治疗满意度97.56%与对照组70.73%比较明显更高(P <0.05)。结论针对行口腔种植修复治疗的附着龈缺失患者采用附着龈重建治疗修复方案利于快速恢复附着龈增加宽度,改善龈缘外形及附着点重建效果,获得患者的高度满意度,治疗价值较高。  相似文献   
7.
目的:黄柏是中国传统大宗中药材,"三木药材"之一,国家二级保护植物,是退耕还林、天然林保护工程和荒山造林的优良树种,具有较高的经济和生态价值。根据物种和产地不同,黄柏分为"川黄柏"和"关黄柏",通过产地适宜性研究分析其潜在的适宜分布区,为正确选择物种及栽培区域提供科学依据。方法:收集全球道地产区、主产区、野生分布区样点生态信息,其中川黄柏364个样点,关黄柏247个样点,采用《药用植物全球产地生态适宜性信息系统》(GMPGIS)分析其全球适宜生长区域。结果:川黄柏和关黄柏全球适宜分布区域有明显分界,川黄柏主要分布于亚热带季风气候区,在亚洲、欧洲、北美洲、南美洲、大洋洲均有一定面积的最大生态相似度区域,包括中国、美国、法国、巴西、日本、意大利、新西兰等65个国家和地区。关黄柏主要分布于温带季风气候区,在亚洲、欧洲、北美洲有一定的生态相似度区域,包括美国、中国、俄罗斯、加拿大等30个国家和地区。结论:GMPGIS分析结果能为黄柏引种时选择正确的基原物种和栽培区域提供科学依据。  相似文献   
8.
Immune defenses provide resistance against infectious disease that is critical to survival. But immune defenses are costly, and limited resources allocated to immunity are not available for other physiological or developmental processes. We propose a framework for explaining variation in patterns of investment in two important subsystems of anti-pathogen defense: innate (non-specific) and acquired (specific) immunity. The developmental costs of acquired immunity are high, but the costs of maintenance and activation are relatively low. Innate immunity imposes lower upfront developmental costs, but higher operating costs. Innate defenses are mobilized quickly and are effective against novel pathogens. Acquired responses are less effective against novel exposures, but more effective against secondary exposures due to immunological memory. Based on their distinct profiles of costs and effectiveness, we propose that the balance of investment in innate versus acquired immunity is variable, and that this balance is optimized in response to local ecological conditions early in development. Nutritional abundance, high pathogen exposure and low signals of extrinsic mortality risk during sensitive periods of immune development should all favor relatively higher levels of investment in acquired immunity. Undernutrition, low pathogen exposure, and high mortality risk should favor innate immune defenses. The hypothesis provides a framework for organizing prior empirical research on the impact of developmental environments on innate and acquired immunity, and suggests promising directions for future research in human ecological immunology.  相似文献   
9.
BackgroundUsing a mobile phone while performing a postural and locomotor tasks is a common, daily situation. Conversing or sending messages (SMS) while walking account for a significant share of accidental injuries. Therefore, understanding the consequences of using a mobile phone on balance and walking is important, all the more so when these postural and locomotor tasks are aggravated by a disease.Research questionOur objective was to conduct a scoping review on the influence of a dual-task situation – generated by the use of mobile phone – on users' postural and/or locomotor tasks.MethodsThe literature search was conducted in English on PubMed/Medline and CINHAL databases, using keywords associated with postural and locomotor tasks and with the use of mobile phone. Study location, population, number of subjects, experimental design, types of phone use, evaluated postural-locomotor tasks and expected effects were then analyzed.Results and significance46 studies were included in this work, 24 of which came from North America. All studies compared postural and locomotor tasks with and without the use of a smartphone. Ten studies also compared at least 2 groups with different characteristics. Only 4 studies included pathological subjects. Various modalities were tested, and most studies focused on walking. Results show that the use of smartphones slows down movement and induces a systematic imbalance, except when listening to music. The dual task of "using the smartphone during a postural or locomotor tasks" induces systematic disturbances of balance and movement, which must be taken into account in the rehabilitation approach. Future studies will have to extend the knowledge regarding pathological situations.  相似文献   
10.
升麻是东北地区重要道地药材之一。近年来,随着市场需求量增大,导致升麻野生资源日益减少。目前,升麻人工栽培技术研究处于探索阶段,并未形成完整的栽培体系。因此,可直接以无公害种植标准对升麻药材进行无公害种植生产研究并推广。为了指导无公害升麻药材生产,生产安全有效、质量稳定的中药材,本文依据本课题组多年研究结果,结合升麻药材的生长特性和研究现状,探索建立升麻药材无公害栽培技术体系,促进升麻药材无公害、标准化、产业化发展。  相似文献   
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