首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1062篇
  免费   120篇
  2021年   11篇
  2020年   6篇
  2019年   6篇
  2018年   8篇
  2017年   14篇
  2016年   23篇
  2015年   35篇
  2014年   35篇
  2013年   56篇
  2012年   61篇
  2011年   66篇
  2010年   37篇
  2009年   37篇
  2008年   55篇
  2007年   62篇
  2006年   37篇
  2005年   52篇
  2004年   57篇
  2003年   46篇
  2002年   45篇
  2001年   21篇
  2000年   18篇
  1999年   20篇
  1998年   17篇
  1997年   12篇
  1996年   8篇
  1995年   13篇
  1994年   16篇
  1993年   12篇
  1992年   15篇
  1991年   10篇
  1990年   16篇
  1989年   9篇
  1988年   11篇
  1987年   19篇
  1986年   11篇
  1985年   19篇
  1984年   11篇
  1983年   18篇
  1982年   10篇
  1981年   8篇
  1980年   14篇
  1979年   7篇
  1978年   7篇
  1974年   5篇
  1972年   8篇
  1969年   8篇
  1967年   5篇
  1965年   5篇
  1962年   6篇
排序方式: 共有1182条查询结果,搜索用时 31 毫秒
101.
102.

Background

In the last two decades, India has witnessed a substantial decrease in infant mortality attributed to infectious disease and malnutrition. However, the mortality attributed to birth defects remains constant. Studies on the prevalence of birth defects such as neural tube defects and orofacial clefts in India have reported inconsistent results. Therefore, we conducted a systematic review of observational studies to document the birth prevalence of neural tube defects and orofacial clefts.

Methods

A comprehensive literature search for observational studies was conducted in MEDLINE and EMBASE databases using key MeSH terms (neural tube defects OR cleft lip OR cleft palate AND Prevalence AND India). Two reviewers independently reviewed the retrieved studies, and studies satisfying the eligibility were included. The quality of included studies was assessed using selected criteria from STROBE statement.

Results

The overall pooled birth prevalence (random effect) of neural tube defects in India is 4.5 per 1000 total births (95% CI 4.2 to 4.9). The overall pooled birth prevalence (random effect) of orofacial clefts is 1.3 per 1000 total births (95% CI 1.1 to 1.5). Subgroup analyses were performed by region, time period, consanguinity, and gender of newborn.

Conclusion

The overall prevalence of neural tube defects from India is high compared to other regions of the world, while that of orofacial clefts is similar to other countries. The majority of studies included in the review were hospital based. The quality of these studies ranged from low to moderate. Further well-designed, high quality community-based observational studies are needed to accurately estimate the burden of neural tube defects and orofacial clefts in India.  相似文献   
103.

Background

2013 WHO guidelines recommend starting ART at CD4+ T-cell counts ≤500 cells/μL. We present the T-cell counts from adult Africans with HIV shortly following transmission to their sexual partners.

Methods

HIV-discordant couples in Zambia, Uganda and Rwanda were followed prospectively and received couples counseling and condoms. HIV uninfected partners were tested for HIV at least quarterly and HIV-infected partners received HIV care and referral for ART per national guidelines. Upon diagnosis of incident HIV infection in the previously HIV-uninfected partner, a blood sample was collected from both partners to measure CD4+ T-cells and perform viral linkage. The estimated date of infection (EDI) of the incident case was calculated based on testing history. EDI was unknown for suspected transmitting partners.

Results

From 2006–2011, 4,705 HIV-discordant couples were enrolled in this cohort, and 443 cases of incident HIV infection were documented. Virus linkage analysis was performed in 374 transmission pairs, and 273 (73%) transmissions were linked genetically. CD4 counts in the transmitting partner were measured a median of 56 days after EDI (mean:90.5, min:10, max:396). The median CD4 count was 339 cells/μl (mean:386.4, min:15, max:1,434), and the proportion of partners with a CD4+ T-cell count above 500/μl was 25% (95% CI:21, 31).

Conclusions

In our cohort of discordant couples, 73% of HIV transmissions occurred within the relationship, and the transmitter CD4+ T cell count shortly after the transmission event was frequently higher than the WHO 2013 ART-initiation guidelines.  相似文献   
104.
Modification of the acyl moiety in the CCR5 lead molecule 2 led to identification of several new classes of CCR5 antagonists. Antiviral activity and pharmacokinetic properties of the synthesized compounds were evaluated. Structure-activity relationship (SAR) derived from these studies further guided the optimization efforts, ultimately leading to the discovery of 36 with an acceptable drug-like profile.  相似文献   
105.
106.
107.
108.
109.
A novel vector has been constructed for the constitutive luminescent tagging of gram-negative bacteria by site-specific integration into the 16S locus of the bacterial chromosome. A number of gram-negative pathogens were successfully tagged using this vector, and the system was validated during murine infections of living animals.  相似文献   
110.
Salmonella spp. infection is a major cause of gastroenteritis, with many thousands of cases reported in the European Union every year. The use of probiotics offers the potential to improve this situation. Here, we investigate the effects of oral treatment of pigs with a defined lactic acid bacteria culture mixture on both clinical and microbiological signs of Salmonella enterica serovar Typhimurium infection. Fifteen weaned pigs blocked by sex and weight were administered control milk or a mixture of five probiotic strains as either a milk fermentate or milk suspension for a total of 30 days. The mixture consisted of two strains of Lactobacillus murinus and one strain each of Lactobacillus salivarius subsp. salivarius, Lactobacillus pentosus, and Pediococcus pentosaceous. Following probiotic administration for 6 days, animals were challenged orally with serovar Typhimurium; the health of the animals and the microbiological composition of their feces were monitored for 23 days postinfection. Animals treated with probiotic showed reduced incidence, severity, and duration of diarrhea. These animals also gained weight at a greater rate than control pigs administered skim milk. Mean fecal numbers of Salmonella were significantly reduced in probiotic-treated animals at 15 days postinfection (P = 0.01). The administered probiotic bacteria improved both the clinical and microbiological outcome of Salmonella infection. These strains offer significant benefit for use in the food industry and may have potential in human applications.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号