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1.
INTRODUCTION Today, Acquired Immunodeficiency Syndrome (AIDS) has become a public health and social problem that has caused significant harm to the survival and development of humanbeings. Route of transmission of Human Im- munodeficiency Virus (HIV) is still predominantly through shared syringes by drug abusers. Currently, there is no efficient medicine, treatment or educational method to prevent HIV transmission in China. Intervention is prob- ably the best “vaccine” [1]. Despi…  相似文献   

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3.
Li XP  Xiao SZ  Wan QQ  Song SL  Teng YX 《Cell research》2005,15(11-12):891-894
The objective of this study is to explore a potentially effective training method for the hospital professionals to educate drug users and to enhance their knowledge of HIV infection. One hundred and sixty one subjects, who came from 13 different provinces and were admitted in a drug relief hospital in Beijing, were recruited for this study. The average age of these subjects was 35.21 +/- 6.24 year old. The average numbers of years for drug addiction were 7 years, and the average numbers of drug relief treatment received in the past was 5.5 times. The level of AIDS knowledge of these subjects, including pathogenic factors, source of infection, route of transmission and preventive measures, were evaluated before and after receiving the AIDS educational training to these drug users. Our results showed that there was a statistically significant increase (P<0.01) in the knowledge of HIV infection and prevention among these subjects. Positive attitude and behavioral tendencies toward HIV prevention were also improved. Therefore, it is imperative for the medical professionals to incorporate AIDS education into drug relief treatment to achieve the maximum effect on the knowledge of AIDS and improvement of positive attitudes and behaviors toward HIV prevention among drug users.  相似文献   

4.
Injection drug use and HIV/AIDS transmission in China   总被引:1,自引:0,他引:1  
INTRODUCTION Although sexual transmission accounts for most of the AIDS epidemic globally, HIV/AIDS among injecting drug users (IDUs) is a growing problem worldwide. First de- tected in China in 1989 among drug abusers on the Yunnan border, HIV/AIDS subse…  相似文献   

5.
This paper presents a sex-structured model for heterosexual transmission of HIV/AIDS in which the population is divided into three subgroups: susceptibles, infectives and AIDS cases. The subgroups are further divided into two classes, consisting of individuals involved in high-risk sexual activities and individuals involved in low-risk sexual activities. The model considers the movement of individuals from high to low sexual activity groups as a result of public health educational campaigns. Thus, in this case public health educational campaigns are resulting in the split of the population into risk groups. The equilibrium and epidemic threshold, which is known as the basic reproductive number (R0), are obtained, and stability (local and global) of the disease-free equilibrium is investigated. The model is extended to incorporate sex workers, and their role in the spread of HIV/AIDS in settings with heterosexual transmission is explored. Comprehensive analytic and numerical techniques are employed in assessing the possible community benefits of public health educational campaigns in controlling HIV/AIDS. From the study, we conclude that the presence of sex workers enlarges the epidemic threshold R0, thus fuels the epidemic among the heterosexuals, and that public health educational campaigns among the high-risk heterosexual population reduces R0, thus can help slow or eradicate the epidemic.  相似文献   

6.
In China, the estimated number of HIV infected cases is approaching one million. Although public education has been initiated for awareness and behavioral modification for this devastating infection, better diagnostic methods are needed to identify infected persons and manage infection. Simple and more accurate diagnostic tools have become available,particularly for early detection and to monitor treatment in those who receive anti-retroviral treatment. In this short review, we summarize some of the common and new methodologies that can be used in clinical laboratories, in the field,or in private laboratories. These range from simple antibody tests to more sophistical methods that are used to monitor disease progression and identify drug resistance. These tools can assist physicians, medical practitioners, and laboratory personnel to select suitable diagnostic tools for the diagnosis, blood screening, monitoring of disease progression, and for detection of drug resistance to anti-retroviral therapies.  相似文献   

7.
DIAGNOSIS OF HIV-1 INFECTION The diagnosis of HIV infection is most commonly ac- complished using tests to detect antibody to HIV using a screening test, followed by a supplemental test for confirmation. However, in many countries, including China, screen…  相似文献   

8.
设置扦插法、纱布包裹法、布袋覆土法3种种植方式,研究苦草(Vallisneria natans(Lour.)Hara)在静态水环境下和水体受到持续扰动的动态条件下不同种植方式对植株生长的影响。结果显示,不同种植方式下苦草的生长差异明显。在苦草形态特征方面,布袋覆土法种植方式下苦草的平均株高和叶宽明显高于扦插法和纱布包裹法,但是其分株数和平均根长小于扦插法和纱布包裹法;在苦草的生物量和地下与地上部分之比方面,布袋覆土法种植方式下苦草的地上、地下部分生物量和总生物量明显大于扦插法和纱布包裹法,但是其地下与地上部分生物量之比小于其他2种方法;在苦草叶片叶绿素a含量方面,布袋覆土法明显高于扦插法和纱布包裹法。动静态水环境只对苦草的分株数有显著差异,静态水环境下分株数大于动态水环境,对其他指标无显著影响。研究结果表明动、静态水环境和不同种植方式对苦草的生长具有显著的影响,布袋覆土法种植方式下单株苦草生长最好;静态水环境下生长的苦草株高、叶宽和生物量等指标均优于动态水环境。  相似文献   

9.
Effects of 14 pyrrol-carboxylic acid derivatives and analogues (PY-compounds) on the growth of coliphage MS2 using E. coli E102 (Hfr) as the host were measured by the agar double-layer method. Enlargements of plaque size were observed with 7 PY-compounds but increase in plaque numbers was not induced. These enlargements of plaque size were specific to RNA coliphages MS2, GA and qbeta and not found with DNA coliphages delta AC and T4. Furthermore, the interaction between PY-compound PY-10 and the coliphage MS2 was dependent on the host bacterium (indicator strain). When E102 (Hfr) was used, the enlargement was marked, in the case of substrain W1895 (Hfr) it was less, while in the case of substrain W6 (F+) it was undetectable. The one-step growth of the phage MS2 and the production of intracellular phage MS2 were little affected by the PY-compound PY-10. However, the rate of one-step growth was increased in the early stage after infection. Accordingly, the enlargements of plaque size by the PY-compounds might be correlated with an increase in rate of release of phage particles.  相似文献   

10.
杨寅  邱钰明  王中斌  曲来叶 《生态学报》2020,40(21):7621-7629
对内蒙古根河大兴安岭林区1987年(恢复后期)、2013年(恢复前期)的皆伐与渐伐样地以及未采伐对照样地兴安落叶松的根际土壤理化性质、微生物群落结构和多样性进行了分析,旨在揭示不同主伐方式对兴安落叶松根际土壤理化性质以及微生物群落的影响。结果表明,主伐后兴安落叶松根际土壤的理化性质以及微生物群落的变化特征与非根际土壤存在区别,且不同主伐方式在不同恢复时期会对兴安落叶松根际土壤理化性质以及微生物群落产生不同的影响:(1)根际与非根际土壤微生物群落中真菌均比细菌更容易受到土壤理化性质的影响,但是单一种理化性质的改变对根际与非根际土壤微生物群落均不能造成显著影响。(2)相较于未采伐对照样地,皆伐样地恢复前期兴安落叶松根际土壤理化性质、微生物群落结构和多样性没有显著变化。皆伐样地恢复后期,兴安落叶松根际土壤理化性质(总碳、总氮、速效氮、pH)发生了显著变化,导致了微生物量碳氮、真菌磷脂脂肪酸(PLFA)含量显著降低、细菌/真菌显著升高,辛普森多样性指数显著降低。(3)渐伐样地恢复前期兴安落叶松根际土壤总碳、总氮、速效氮含量以及含水量均显著降低,总钾、速效磷含量显著上升,根际土壤微生物量碳含量显著降低。恢复后期,兴安落叶松根际土壤总磷含量显著升高,根际土壤微生物量碳的含量已恢复到渐伐前水平。渐伐干扰对根际土壤各微生物类群PLFA含量、微生物群落结构以及多样性没有显著影响。  相似文献   

11.
Awuah RT  Ellis WO 《Mycopathologia》2002,154(1):29-36
Powders from the leaves of Ocimum gratissimum and cloves of Syzygium aromaticum were used as protectants at 3% (w/w) in combination with various packaging methods to store 3.5 kg groundnut kernel samples (9.3% moisture) artificially inoculated with Aspergillus parasiticus. Phostoxin-protected and unprotected samples were the controls. Packaging was accomplished with (i) Jute bags; JB (ii) Interlaced polypropylene bags; IPPB (iii) Polyethylene bags; PB (iv) PB inserted into IPPB and (v) PB inserted into JB. Selected treatments were repeated concurrently with naturally infected kernels (6.6% moisture). With 9.3% moisture kernels, there was a highly significant protectant, packaging method, and protectant X packaging method effect on protection of kernels from fungal infection at 2, 4, and 6 months. Packaging with JB and IPPB with or without plant powders gave 100% protection against fungi but insect infestation was prevented only when the Syzygium powder was used. When PB was used either singly or in combination with JB and IPPB, 100% protection from fungi was achieved up to 2 months with the Ocimum and up to 4 months with the Syzygium powder. The phostoxin treatment also gave 100% protection with JB and IPPB packaging but was ineffective with PB packaging. Kernels packaged with PB without the powders were extensively mouldy. Kernels with natural mycoflora (6.6% moisture) were free from fungi at 6 months regardless of the protectant and packaging used. In further tests, the Syzygium powder, at 3% and in combination with JB-packaging, effectively suppressed cross infection of healthy kernels (12% moisture) by fungi from diseased kernels when both kernel types occurred in the same lot. At 18.5% kernel moisture and with identical packaging, the Syzygium powder at 3%, was not as effective. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

12.
几种药剂及施药方式对稻纵卷叶螟的防治效果   总被引:2,自引:1,他引:2  
对稻纵卷叶螟Cnaphalocrocis medinalis Guen e高龄幼虫防治药剂31%氟虫腈.三唑磷ME和当地几种常用药剂及不同施药方法对防治效果影响进行试验。结果表明:(1)毒死蜱(48%乐斯本EC)有较好速效性,药后1 d可达理想防效,三唑磷与氟出腈、氟铃脲复配的药剂(31%氟虫腈.三唑磷ME、21%氟虫腈.三唑磷EC、15%氟铃脲.三唑磷EC)药后3d才能达到理想防效;(2)药后3d,各处理均达到理想防效,防效依次为31%氟虫腈.三唑磷ME1.5L/hm2>31%氟虫腈.三唑磷ME1.05L/hm2>21%氟虫腈.三唑磷EC1.5L/hm2>48%毒死蜱EC1.5L/hm2>15%氟虫腈.三唑磷EC1.5L/hm2>15%阿维菌素.毒死蜱EC1.5L/hm2;(3)分虫龄防效统计,药后3d供试药剂对1龄以下(施药时虫龄,后同)幼虫防效均在91%以上,对2~3龄幼虫,31%氟虫腈.三唑磷ME保持90%以上的防效,其它处理防效明显下降,对4龄以上高龄幼虫,31%氟虫腈.三唑磷1.5L/hm2细喷雾处理防效仍达95.6%,其它处理防效很低。(4)细喷雾可提高31%氟虫腈.三唑磷ME对稻纵卷叶螟的防治效果,尤其是对高龄幼虫,与工农16型1.8mm孔径喷片的常规喷雾相比,1.2mm孔径喷片细喷雾处理药后3 d防效提高5.5%,东方红18型弥雾处理防效提高7.8%,其中,弥雾处理对1~2龄幼虫防效提高4.7%,对4~5龄幼虫防效提高了20.8%。  相似文献   

13.
模拟降雨条件下施肥方法对坡面磷素流失的影响   总被引:21,自引:3,他引:21  
李裕元  邵明安 《应用生态学报》2002,13(11):1421-1424
采用模拟降雨的方法研究了3种施肥方法对P素流失形态与流失过程的影响。结果表明,P肥在土壤中的混匀程度越高,则越容易导致生物有效P(BAP)的流失,混施条件下,径流中水溶态P(DP)与AP含量,DP/BAP与BAP/TP(总P)比值均较高;其次为穴施;实施条件下DP,BAP含量最低,DP/BAP与BAP/TP比值也相对较低,与对照间的差异不明显。施肥方法对径流中TP含量影响较小,从减少P素肥料流失的角度来讲,3种施肥方法作用大小顺序为:条施>穴施>混施。  相似文献   

14.
栖息地片断化指在人为活动和自然干扰下,大面积连续分布的自然栖息地被其它非适宜栖息地分隔成许多面积较小的斑块(岛屿)的过程。栖息地片断化是导致生物多样性丧失和物种绝灭的主要因素,也是威胁自然界生物生存的重要因素之一。栖息地片断化将影响基因在种群间和种群内的运动(基因流),开展栖息地片断化研究对保持物种间遗传多样性具有重要意义。本文介绍了片断化程度和基因流的测定方法。回顾了国内外的研究现状,并探讨了片断化对种群间基因流的影响和对濒危物种保护的意义。  相似文献   

15.
Introduction – The chemometric characterisation of two plants frequently used as food and medicinal species, Achyrocline satureioides and Achyrocline venosa (Asteraceae: Gnaphalieae), was carried out based on their mineral composition. Both species, known by the common name of ‘marcelas’, are very similar in their morphological features but they have different medicinal and food properties. Objective – To develop multivariate models for the classification of A. satureiodes and A. venosa based on their mineral content. Methodology – The analytic determinations were made by means of inductively coupled plasma optical emission spectrometry from aerial parts of the plants. An internal standard was used to evaluate the accuracy in the sample treatment and the recovery of toxic elements was studied. The multivariate methods used include principal components analysis, cluster analysis and linear discriminant analysis. Results – Classification for both A. satureioides and A. venosa was successful in all cases using only four variables: aluminium, iron, magnesium and sulphur content. The concentrations of the following elements were determined: Al, As, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, La, Mg, Mn, Mo, Na, Ni, P, Pb, S, Sr, Ti, V, Y and Zn. Conclusions – This method is useful to identify both species in raw material in order to detect eventual errors of selection. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

16.
施氮方式对转基因棉花Bt蛋白含量及产量的影响   总被引:3,自引:0,他引:3  
为研究氮肥运筹对棉花叶片、棉蕾和棉铃不同器官中Bt蛋白含量的影响,2009—2010年,以抗虫杂交棉中棉所72为试验材料,在大田条件下进行了不同基肥:花铃肥:盖顶肥施氮比例(分别为0:0.4:0.6、0.2:0.4:0.4、0.4:0.4:0.2、0.6:0.4:0)的试验。结果表明,施氮方式对棉花不同器官中Bt蛋白含量有明显影响。总体表现为随着氮肥前移,棉花幼嫩器官中Bt蛋白含量呈明显增加的趋势,而老熟器官中Bt蛋白含量呈明显降低的趋势。施氮方式对棉花幼嫩器官中Bt蛋白含量的影响比老熟器官明显,尤其是对幼嫩叶片Bt蛋白含量的影响大于幼小的棉蕾和棉铃器官。抗虫棉采用基肥:花铃肥:盖顶肥为0.4:0.4:0.2的施氮方式,总体能提高前中期棉花器官Bt蛋白的含量,有利于提高其抗虫性能;减少后期棉花器官Bt蛋白的含量,减轻对环境的压力;而且比其余3种施氮方式的籽棉产量和皮棉产量分别增加4.15%—11.24%、3.73%—12.01%。  相似文献   

17.
Wong PC  Ciocca V  Chan AH  Ha LY  Tan LH  Peretz I 《PloS one》2012,7(4):e33424
The strong association between music and speech has been supported by recent research focusing on musicians' superior abilities in second language learning and neural encoding of foreign speech sounds. However, evidence for a double association--the influence of linguistic background on music pitch processing and disorders--remains elusive. Because languages differ in their usage of elements (e.g., pitch) that are also essential for music, a unique opportunity for examining such language-to-music associations comes from a cross-cultural (linguistic) comparison of congenital amusia, a neurogenetic disorder affecting the music (pitch and rhythm) processing of about 5% of the Western population. In the present study, two populations (Hong Kong and Canada) were compared. One spoke a tone language in which differences in voice pitch correspond to differences in word meaning (in Hong Kong Cantonese, /si/ means 'teacher' and 'to try' when spoken in a high and mid pitch pattern, respectively). Using the On-line Identification Test of Congenital Amusia, we found Cantonese speakers as a group tend to show enhanced pitch perception ability compared to speakers of Canadian French and English (non-tone languages). This enhanced ability occurs in the absence of differences in rhythmic perception and persists even after relevant factors such as musical background and age were controlled. Following a common definition of amusia (5% of the population), we found Hong Kong pitch amusics also show enhanced pitch abilities relative to their Canadian counterparts. These findings not only provide critical evidence for a double association of music and speech, but also argue for the reconceptualization of communicative disorders within a cultural framework. Along with recent studies documenting cultural differences in visual perception, our auditory evidence challenges the common assumption of universality of basic mental processes and speaks to the domain generality of culture-to-perception influences.  相似文献   

18.
家蚕微粒子病是家蚕Bombyx mori的重要病害,探索其消毒杀灭方法对蚕业生产具有重要意义。本研究采用微粒子染色法和添食家蚕侵染法测试了温度、紫外线和消毒剂处理108个/mL家蚕微粒子后对家蚕微粒子的消杀作用,结果表明:温度对家蚕微粒子虫灭活温度为60℃处理30 min以上;使用20 wx功率紫外灯距离50 cm照射12 min及以上时,微粒子死亡率为47.70%,对家蚕侵染率为0;三氯异氰脲酸800 mg/L及以上浓度处理6 min以上家蚕微粒子死亡率为100%,对家蚕的侵染率为0;戊二醛癸甲溴铵200 mg/L及以上浓度处理6 min以上家蚕微粒子死亡率为100%,对家蚕的侵染率为0。3种消毒方法中温度法主要用于小型蚕具消杀微粒子;紫外线用于蚕业辅助设施的表面微粒子的消杀;三氯异氰脲酸和戊二醛癸甲溴铵均表现出较好的消杀效果,其中戊二醛癸甲溴铵较含氯的消毒剂三氯异氰脲酸稳定性强,刺激性小,对养蚕的金属腐蚀性小,可作为含氯消毒剂的部分替代使用。本研究结果可为蚕业生产中消杀微粒子提供参考。  相似文献   

19.
Laboratory experiments were conducted to assess effects of nutrients on germination of Verticillium lecanii (=Lecanicillium sp.) conidia and infection of the greenhouse whitefly, Trialeurodes vaporariorum. Suspensions of V. lecanii conidia were prepared in four nutrient solutions: 2% glucose, 2% sucrose, 2% maltose, and 2% peptone. Suspensions in de-mineralized water served as the control. At 23°C the germination rate was highest in the 2% glucose solution, followed by sucrose, maltose, demineralized water, and peptone, respectively. Germ tube growth was greatest at 23°C in the 2% glucose solution after 10 h incubation. Results of the bioassays indicated that the nutrients influenced whitefly infection. Infection levels were highest for conidial suspensions (1×106 conidia/mL) prepared in 2% glucose, and were significantly greater than for peptone, demineralized water and maltose. Infection levels at 1×108 conidia/mL were not significantly different from each other for all materials tested. The potential use of nutrients in a spray formulation as a means of enhancing field efficacy are discussed.  相似文献   

20.
【目的】本文从功能团的角度研究了不同的麦蚜防治方法对小麦田节肢功能团的影响,为进一步研究小麦田内生物多样性提供了基础。【方法】本试验采用黄板、诱虫灯、糖醋液及3种方法综合使用的方法防治麦蚜,系统调查了这些防治方法对小麦田节肢功能团的影响。【结果】综合使用黄板、诱虫灯、糖醋液防治麦蚜能够提高昆虫群落和蚜虫亚群落的稳定性,降低小麦蚜虫种类和天敌种类丰盛度,采用防治措施的小麦田内捕食性天敌的群落稳定性均较差,单一防治措施的使用对麦田内昆虫群落相对丰盛度、蚜虫亚群落稳定性、捕食性天敌群落稳定性也有一定影响。【结论】在农田生态系统中,不同的防治方法对昆虫群落的影响不同。在实际应用中我们应合理搭配使用麦蚜的防治方法。  相似文献   

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