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   425篇
  免费   17篇
  国内免费   3篇
耳鼻咽喉   3篇
儿科学   28篇
妇产科学   9篇
基础医学   72篇
口腔科学   7篇
临床医学   45篇
内科学   70篇
皮肤病学   2篇
神经病学   29篇
特种医学   6篇
外科学   68篇
综合类   19篇
预防医学   12篇
眼科学   10篇
药学   38篇
中国医学   2篇
肿瘤学   25篇
  2023年   10篇
  2022年   8篇
  2021年   15篇
  2020年   8篇
  2019年   13篇
  2018年   21篇
  2017年   10篇
  2016年   12篇
  2015年   14篇
  2014年   17篇
  2013年   20篇
  2012年   32篇
  2011年   32篇
  2010年   19篇
  2009年   16篇
  2008年   19篇
  2007年   16篇
  2006年   16篇
  2005年   11篇
  2004年   14篇
  2003年   13篇
  2002年   8篇
  2001年   6篇
  2000年   7篇
  1999年   6篇
  1998年   5篇
  1996年   6篇
  1995年   2篇
  1994年   3篇
  1992年   4篇
  1991年   3篇
  1990年   3篇
  1989年   3篇
  1988年   2篇
  1987年   3篇
  1986年   3篇
  1985年   3篇
  1984年   3篇
  1982年   4篇
  1979年   3篇
  1977年   7篇
  1975年   4篇
  1974年   2篇
  1973年   3篇
  1971年   4篇
  1970年   1篇
  1969年   1篇
  1968年   1篇
  1966年   1篇
  1963年   3篇
排序方式: 共有445条查询结果,搜索用时 15 毫秒
91.
92.
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has emerged as one of the most dreadful viruses the mankind has witnessed. It has caused world-wide havoc and wrecked human life. In our quest to find therapeutic options to counter this threat, several drugs have been tried, with varying success. Certain agents like corticosteroids, some anti-virals and immunosuppressive drugs have been found useful in improving clinical outcomes. Vitamin C, a water-soluble vitamin with good safety profile, has been tried to reduce progression and im-prove outcomes of patients with coronavirus disease 2019 (COVID-19). Because of its anti-oxidant and immunomodulatory properties, the role of vitamin C has expanded well beyond the management of scurvy and it is increasingly been employed in the treatment of critically ill patients with sepsis, septic shock, acute pancreatitis and even cancer. However, in spite of many case series, observational studies and even randomised control trials, the role of vitamin C remains ambiguous. In this review, we will be discussing the scientific rationale and the current clinical evidence for using high dose vitamin C in the management of COVID-19 patients.  相似文献   
93.
Testicular teratomas in prepubertal children are distinct from adult testicular teratomas as well as from teratomas located elsewhere in the body, both with respect to their pathologic features and biologic behavior. Over a period of 12 years, testicular teratomas comprised 25% (5 of 20) of all testicular tumors in prepubertal children, treated at our institution. Their clinical presentation and pathologic profile was analysed. Their mean age at presentation was 6.7 m (range 1 m to 18 m) with the mass having been noted at birth in 3 infants. The right testis was involved in all except one patient. Serum AFP was elevated preoperatively in only one case with an immature (grade II) teratoma containing fetal liver tissue. Immunohistochemical staining for AFP and alfa-1-antitrypsin were positive in these fetal liver cells. Serum AFP levels returned to normal after orchiectomy in this patient. While a high inguinal orchiectomy was the standard operative procedure, testicular-sparing surgery was planned in the last two patients. However the tumor had replaced the entire testis in one of these patients, while in the other, the mass was homogeneous, with no visible cystic areas or dermal elements on cut section. Hence both of these patients also underwent orchiectomy. Histologic examination and immunohistochemical staining for AFP were performed on the specimen. Peri-tumor testicular parenchyma was found to be unremarkable and did not stain for placental alkaline phosphatase, a marker for carcinoma in situ. All these children are doing well with no evidence of residual or recurrent disease at a mean follow-up of 4.7 years (range 4 m to 11 yrs).  相似文献   
94.

Background

The infectious disease markers for which blood donors are screened include anti-human immunodeficiency virus (HIV), hepatitis B surface antigen (HBsAg), anti-hepatitis C virus (HCV), rapid plasma reagin (RPR) card test for syphilis and malarial parasites.

Methods

A total of 6751 donors were screened over three years to assess the prevalence of infectious disease markers. Screening for anti-HIV I and II, HBsAg and anti-HCV was carried out by enzyme linked immunosorbent assay (ELISA). Syphilis was tested using RPR card test. Malarial parasite was tested by detection of genus specific plasmodium lactate dehydrogenase.

Result

The overall seropositivity for anti-HIV I and II was nine (0.13%), for HBsAg 67 (0.99%), for anti-HCV 13 (0.19%) and for syphilis 42 (0.62%). No sample showed malarial parasites. There was no significant difference (p>0.05) in the seropositivity of various markers between voluntary and replacement donors. There was a significant decline (p<0.05) in the prevalence of seropositivity for HCV and syphilis, but not for HIV and HBsAg over the three year period of the study.

Conclusion

The prevalence of infectious disease markers was similar to that reported by other studies. However, no significant difference was seen in the marker positivity in voluntary and replacement donors, which is at variance from other studies.Key Words: Infectious disease, Blood donors  相似文献   
95.
Indoor resting freshly engorged Culex quinquefasciatus collected from three different habitats viz., human, cattle and mixed dwellings of six localities of Raipur city, were analyzed for the source of blood meal by precipitin test. Of the 60 specimens from human dwellings 52 were positive for human blood with an anthropophilic index of 90%. Of the 25 specimens from cattlesheds 15 were positive for human blood with an index of 60%. Of the 20 specimens from mixed dwellings 12 showed human blood with an anthropophilic index of 63.15%. Thus, the Culex quinquefasciatus at Raipur city in Madhya Pradesh state is predominantly anthropophilic in nature irrespective of the nature of habitat of the mosquito vector.  相似文献   
96.
Cells that have evolved to produce large quantities of secreted proteins to serve the integrated functions of complex multicellular organisms are equipped to compensate for protein misfolding. Hepatocytes and plasma cells have well developed chaperone and proteasome systems to ensure that secreted proteins transit the cell efficiently. The number of neurodegenerative disorders associated with protein misfolding suggests that neurons are particularly sensitive to the pathogenic effects of aggregates of misfolded molecules because those systems are less well developed in this lineage. Aggregates of the amyloidogenic (Abeta(1-42)) peptide play a major role in the pathogenesis of Alzheimer's disease (AD), although the precise mechanism is unclear. In genetic studies examining protein-protein interactions that could constitute native mechanisms of neuroprotection in vivo, overexpression of a WT human transthyretin (TTR) transgene was ameliorative in the APP23 transgenic murine model of human AD. Targeted silencing of the endogenous TTR gene accelerated the development of the neuropathologic phenotype. Intraneuronal TTR was seen in the brains of normal humans and mice and in AD patients and APP23 mice. The APP23 brains showed colocalization of extracellular TTR with Abeta in plaques. Using surface plasmon resonance we obtained in vitro evidence of direct protein-protein interaction between TTR and Abeta aggregates. These findings suggest that TTR is protective because of its capacity to bind toxic or pretoxic Abeta aggregates in both the intracellular and extracellular environment in a chaperone-like manner. The interaction may represent a unique normal host defense mechanism, enhancement of which could be therapeutically useful.  相似文献   
97.
98.
99.
Wernicke encephalopathy (WE) was first described by Carl Wernicke in 1881. WE is caused by thiamine deficiency. Alcoholism is the most common etiologic factor associated with WE in the United States, but it can occur in any patient with a nutritional deficiency state such as hyperemesis gravidarum, intestinal obstruction, and malignancy. WE is a clinical diagnosis. The common findings include mental status changes, ocular dysfunction, and a gait apraxia, present in only 10% of cases. Only a few cases of WE are diagnosed before death. Approximately 80% of patients with untreated WE have development of Korsakoff syndrome, which is characterized by memory impairment associated with confabulation. The initial clinical diagnosis of WE is critical, keeping in mind that the classic triad of symptoms is often absent. Recognition of nutritional deficiency and any portion of the classic triad should prompt treatment. Additionally, hypothermia, hypotension, and coma should raise clinical suspicion for the disease. Primary treatment includes timely administration of thiamine, for which the route and dosage remain controversial. Clinical judgment should be exercised in diagnosis and treatment (dosage, frequency, route of administration and duration) in all cases of WE. Overdiagnosis and overtreatment may be preferred to prevent prolonged or persistent neurocognitive impairments given the excellent safety profile of thiamine. Further prospective research is warranted to better understand the disease biology, risk factors, and treatment recommendations.  相似文献   
100.

Background

Online access to medical records by patients can potentially enhance provision of patient-centred care and improve satisfaction. However, online access and services may also prove to be an additional burden for the healthcare provider.

Aim

To assess the impact of providing patients with access to their general practice electronic health records (EHR) and other EHR-linked online services on the provision, quality, and safety of health care.

Design and setting

A systematic review was conducted that focused on all studies about online record access and transactional services in primary care.

Method

Data sources included MEDLINE, Embase, CINAHL, Cochrane Library, EPOC, DARE, King’s Fund, Nuffield Health, PsycINFO, OpenGrey (1999–2012). The literature was independently screened against detailed inclusion and exclusion criteria; independent dual data extraction was conducted, the risk of bias (RoB) assessed, and a narrative synthesis of the evidence conducted.

Results

A total of 176 studies were identified, 17 of which were randomised controlled trials, cohort, or cluster studies. Patients reported improved satisfaction with online access and services compared with standard provision, improved self-care, and better communication and engagement with clinicians. Safety improvements were patient-led through identifying medication errors and facilitating more use of preventive services. Provision of online record access and services resulted in a moderate increase of e-mail, no change on telephone contact, but there were variable effects on face-to-face contact. However, other tasks were necessary to sustain these services, which impacted on clinician time. There were no reports of harm or breaches in privacy.

Conclusion

While the RoB scores suggest many of the studies were of low quality, patients using online services reported increased convenience and satisfaction. These services positively impacted on patient safety, although there were variations of record access and use by specific ethnic and socioeconomic groups. Professional concerns about privacy were unrealised and those about workload were only partly so.  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