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   104篇
  免费   6篇
  110篇
  2024年   2篇
  2023年   1篇
  2022年   2篇
  2021年   3篇
  2020年   2篇
  2018年   3篇
  2016年   11篇
  2015年   2篇
  2014年   9篇
  2013年   8篇
  2012年   5篇
  2011年   9篇
  2010年   6篇
  2009年   4篇
  2008年   6篇
  2007年   6篇
  2006年   5篇
  2005年   3篇
  2004年   6篇
  2003年   2篇
  2002年   5篇
  2001年   2篇
  2000年   1篇
  1999年   2篇
  1998年   1篇
  1997年   1篇
  1992年   1篇
  1977年   2篇
排序方式: 共有110条查询结果,搜索用时 0 毫秒
61.

Background

In contrast to the developed nations, invasive cervical cancer (ICC) is the most common womens malignancy in Kenya and many other locations in sub-Saharan Africa. However, studies on survival from this disease in this area of the world are severely restricted by lack of patient follow-up. We now report a prospective cohort study of ICC in Kenyan women analysing factors affecting tumour response and overall survival in patients undergoing radiotherapy.

Methods and Findings

Between 2008 and 2010, 355 patients with histologically confirmed ICC were recruited at the Departments of Gynaecology and Radiotherapy at Kenyatta National Hospital (KNH). Structured questionnaires were completed recording socio-demographics, tumour response and overall survival following treatment with combinations of external beam radiation (EBRT), brachytherapy and adjuvant chemotherapy. Of the 355 patients, 42% (146) were lost to follow-up while 18% (64) died during the two year period. 80.5% of patients presented with advanced stage IIB disease or above, with only 6.7% of patients receiving optimal combined EBRT, brachytherapy and adjuvant chemotherapy. Kaplan Meier survival curves projected two year survival at <20%.

Conclusion

Cervical cancer is preventable yet poverty, poor education, lack of cancer awareness coupled with an absence of regular screening programs, late patient presentation, sub-optimal diagnosis and treatments are major factors contributing to the alarmingly low survival rate of cervical cancer patients in Kenya. It is concluded that simple cost-effective changes in clinical practice could be introduced which would have a marked impact on patient survival in this setting.  相似文献   
62.
Insensitive acetylcholinesterase resistance due to a mutation in the acetylcholinesterase (ace) encoding ace-1 gene confers cross-resistance to organophosphate and carbamate insecticides in Anopheles gambiae populations from Central and West Africa. This mutation is associated with a strong genetic cost revealed through alterations of some life history traits but little is known about the physiological and behavioural changes in insects bearing the ace-1R allele. Comparative analysis of the salivary gland contents between An. gambiae susceptible and ace-1R resistant strains was carried out to charaterize factors that could be involved in modifications of blood meal process, trophic behaviour or pathogen interaction in the insecticide-resistant mosquitoes. Differential analysis of the salivary gland protein profiles revealed differences in abundance for several proteins, two of them showing major differences between the two strains. These two proteins identified as saglin and TRIO are salivary gland-1 related proteins, a family unique to anopheline mosquitoes, one of them playing a crucial role in salivary gland invasion by Plasmodium falciparum sporozoites. Differential expression of two other proteins previously identified in the Anopheles sialome was also observed. The differentially regulated proteins are involved in pathogen invasion, blood feeding process, and protection against oxidation, relevant steps in the outcome of malaria infection. Further functional studies and insect behaviour experiments would confirm the impact of the modification of the sialome composition on blood feeding and pathogen transmission abilities of the resistant mosquitoes. The data supports the hypothesis of alterations linked to insecticide resistance in the biology of the primary vector of human malaria in Africa.  相似文献   
63.

Background

Health concerns for HIV-infected persons on antiretroviral therapy (ART) have moved from morbidity to the challenges of long-term ART. We investigated the effect of Zidovudine or Nevirapine on reproductive capacity across two mouse generations.

Methods

A prospective mouse study with drugs administered through one spermatogenic cycle. Mouse groups (16 males and 10 females) were given Zidovudine or Nevirapine for 56 days. Males were mated to untreated virgin females to determine dominant lethal effects. Twenty females (10 treated and 10 untreated) mated with the treated males per dose and gave birth to the F1 generation. Parental mice were withdrawn from drugs for one spermatogenic cycle and mated to the same dams to ascertain if effects are reversible. The F1 generation were exposed for another 56 days and mated to produce the F2 generation.

Results

Foetal loss was indicated in the dominant lethal assay as early as four weeks into drug administration to the males. At the first mating of the parental generation to produce the F1 generation, births from 10 dams/dose when the ‘father-only’ was exposed to Zidovudine (10, 100 and 250 mg/kg) was 3, 2 and 1 while it was 7, 1 and 4 respectively when ‘both-parents’ were exposed. Similarly births from the parental generation first mating when the ‘father-only’ was exposed to Nevirapine (5, 50 and 150 mg/kg) was 2, 2 and 0 while it was 6, 5 and 9 respectively when ‘both-parents’ were exposed. However, fertility was not significantly different neither by dose nor by the parental exposure. The F1 mice mated to produce the F2 generation recorded only one birth.

Conclusion

The dominant lethal analysis showed foetal loss occurred when the “fathers-only” were treated while fertility was enhanced when “both-parents” were on therapy at the time of mating.  相似文献   
64.
65.
66.
We provide here the first bottom-up review of the lived experience of mental disorders in adolescents co-designed, co-conducted and co-written by experts by experience and academics. We screened first-person accounts within and outside the medical field, and discussed them in collaborative workshops involving numerous experts by experience – representing different genders, ethnic and cultural backgrounds, and continents – and their family members and carers. Subsequently, the material was enriched by phenomenologically informed perspectives and shared with all collaborators. The inner subjective experience of adolescents is described for mood disorders, psychotic disorders, attention-deficit/hyperactivity disorder, autism spectrum disorders, anxiety disorders, eating disorders, externalizing disorders, and self-harm behaviors. The recollection of individuals’ past histories also indexes the prodromal (often transdiagnostic) features predating the psychiatric diagnosis. The experience of adolescents with mental disorders in the wider society is described with respect to their family, their school and peers, and the social and cultural context. Furthermore, their lived experience of mental health care is described with respect to receiving a diagnosis of mental disorder, accessing mental health support, receiving psychopharmacological treatment, receiving psychotherapy, experiencing peer support and mental health activism, and achieving recovery. These findings can impact clinical practice, research, and the whole society. We hope that this co-designed, co-conducted and co-written journey can help us maintain our commitment to protecting adolescents’ fragile mental health, and can help them develop into a healthy, fulfilling and contributing adult life.  相似文献   
67.
Erythrocyte invasion by malaria parasites requires multiple protein interactions. Our earlier studies showed that erythrocyte band 3 is an invasion receptor binding Plasmodium falciparum merozoite surface protein 1 and 9 (MSP1, MSP9) existing as a co-ligand complex. In this study, we have used biochemical approaches to identify the binding sites within MSP1 and MSP9 involved in the co-ligand complex formation. A major MSP9-binding site is located within the 19kDa C-terminal domain of MSP1 (MSP1(19)). Two specific regions of MSP9 defined as Delta1a and Delta2 interacted with native MSP1(19). The 42 kDa domain of MSP1 (MSP1(42)) bearing MSP1(19) in the C-terminus bound directly to both MSP9/Delta1a and Delta2. Thus, the regions of MSP1 and MSP9 interacting with the erythrocyte band 3 receptor are also responsible for assembling the co-ligand complex. Our evidence suggests a ternary complex is formed between MSP1, MSP9, and band 3 during erythrocyte invasion by P. falciparum.  相似文献   
68.
A recent study suggests that aggression between wasps depends upon the costs and benefits of fighting, as determined by the position of individuals in a dominance hierarchy.  相似文献   
69.
Continuing antigenic drift allows influenza viruses to escape antibody-mediated recognition, and as a consequence, the vaccine currently in use needs to be altered annually. Highly conserved epitopes recognized by effector T cells may represent an alternative approach for the generation of a more universal influenza virus vaccine. Relatively few highly conserved epitopes are currently known in humans, and relatively few epitopes have been identified from proteins other than hemagglutinin and nucleoprotein. This prompted us to perform a study aimed at identifying a set of human T-cell epitopes that would provide broad coverage against different virus strains and subtypes. To provide coverage across different ethnicities, seven different HLA supertypes were considered. More than 4,000 peptides were selected from a panel of 23 influenza A virus strains based on predicted high-affinity binding to HLA class I or class II and high conservancy levels. Peripheral blood mononuclear cells from 44 healthy human blood donors were tested for reactivity against HLA-matched peptides by using gamma interferon enzyme-linked immunospot assays. Interestingly, we found that PB1 was the major target for both CD4(+) and CD8(+) T-cell responses. The 54 nonredundant epitopes (38 class I and 16 class II) identified herein provided high coverage among different ethnicities, were conserved in the majority of the strains analyzed, and were consistently recognized in multiple individuals. These results enable further functional studies of T-cell responses during influenza virus infection and provide a potential base for the development of a universal influenza vaccine.  相似文献   
70.
For conservation purposes and due to growing ecotourism, free-ranging mountain gorillas (Gorilla gorilla beringei) have been habituated to humans. Fecal specimens (n = 62) collected in January 1999 from mountain gorillas of the Bwindi and Mgahinga National Parks, Uganda, were tested for Campylobacter spp., Salmonella spp., and Shigella spp., and the overall prevalence of infection was 19%, 13%, and 6%, respectively. The prevalence of positive specimens was not related to the year of habituation of a gorilla group to humans. Campylobacter spp., Salmonella, and Shigella spp. infections were not distributed equally among the age classes of gorillas; most of the enteropathogens (80%), and all Shigella spp. organisms, S. sonnei, S. boydii, and S. flexneri, were isolated from subadults and adult gorillas with ages ranging from 6.0 to 11.9 yr. The prevalence of Campylobacter spp. and Salmonella spp. infections among human-habituated gorillas has doubled during the last 4 yr, and isolation of Shigella spp. for the first time from mountain gorillas, may indicate enhanced anthropozoonotic transmission of these enteropathogens.  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