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   1865篇
  免费   111篇
  国内免费   6篇
耳鼻咽喉   18篇
儿科学   103篇
妇产科学   14篇
基础医学   179篇
口腔科学   48篇
临床医学   143篇
内科学   410篇
皮肤病学   37篇
神经病学   95篇
特种医学   78篇
外科学   345篇
综合类   26篇
一般理论   1篇
预防医学   45篇
眼科学   179篇
药学   147篇
中国医学   4篇
肿瘤学   110篇
  2024年   1篇
  2023年   31篇
  2022年   66篇
  2021年   132篇
  2020年   75篇
  2019年   83篇
  2018年   105篇
  2017年   55篇
  2016年   96篇
  2015年   86篇
  2014年   121篇
  2013年   142篇
  2012年   202篇
  2011年   203篇
  2010年   98篇
  2009年   68篇
  2008年   101篇
  2007年   82篇
  2006年   61篇
  2005年   50篇
  2004年   43篇
  2003年   30篇
  2002年   20篇
  2001年   5篇
  2000年   4篇
  1998年   4篇
  1997年   2篇
  1996年   3篇
  1994年   1篇
  1991年   1篇
  1990年   1篇
  1989年   1篇
  1987年   1篇
  1986年   1篇
  1985年   1篇
  1982年   1篇
  1980年   1篇
  1979年   1篇
  1978年   1篇
  1976年   2篇
排序方式: 共有1982条查询结果,搜索用时 109 毫秒
51.
Candida spp have often been reported in cervical cytology, other fungal organisms are very rare in modern literature. We report nine cases of conventional cervical smears showing Penicillium, Aspergillus, and Cladosporium spp in healthy imunocompetent females. Penicillium spp seen in four out of nine smears, Cladosporium spp alone in three out of nine smears, and Cladosporium spp along with Aspergillus spp in two out of nine smears. A detail of these nine cases is presented with discussion on importance of these structures when observed in conventional cervical smears. Awareness of such contaminants is important to differentiate from true infection for relevant therapeutic implications. A systematic step‐wise approach to such structures is also suggested. Diagn. Cytopathol. 2015;43:234–237. © 2014 Wiley Periodicals, Inc.  相似文献   
52.
53.
Malaria and dengue are the two most important vector-borne human diseases caused by mosquito vectors Anopheles stephensi and Aedes aegypti, respectively. Of the various strategies adopted for eliminating these diseases, controlling of vectors through herbs has been reckoned as one of the important measures for preventing their resurgence. Artemisia annua leaf chloroform extract when tried against larvae of A. stephensi and A. aegypti has shown a strong larvicidal activity against both of these vectors, their respective LC50 and LC90 values being 0.84 and 4.91 ppm for A. stephensi and 0.67 and 5.84 ppm for A. aegypti. The crude extract when separated through column chromatography using petroleum ether-ethyl acetate gradient (0–100 %) yielded 76 fractions which were pooled into three different active fractions A, B and C on the basis of same or nearly similar R f values. The aforesaid pooled fractions when assayed against the larvae of A. stephensi too reported a strong larvicidal activity. The respective marker compound purified from the individual fractions A, B and C, were Artemisinin, Arteannuin B and Artemisinic acid, as confirmed and characterized through FT-IR and NMR. This is our first report of strong mortality of A. annua leaf chloroform extract against vectors of two deadly diseases. This technology can be scaled up for commercial exploitation.  相似文献   
54.

Objectives

To describe the clinical presentation and outcome of surgery in children with pheochromocytoma in a tertiary care hospital in India.

Methods

Clinical records of 24 children who were operated between January 1990 and January 2011 were reviewed. The diagnosis of familial disease was established based on clinical examination and follow-up events.

Results

Familial, bilateral, extra-adrenal and malignant pheochromocytoma were observed in 20.8%, 20.8%, 12.5% and 4.2% children, respectively. Median follow-up duration was 36 months. Persistent hypertension was noted in 12.5% patients and similar proportion died in follow-up.

Conclusions

In the absence of routine genetic screening, good history and long-term follow up are essential to rule out familial pheochromocytoma.  相似文献   
55.
This study was a prospective cohort study to evaluate negative pressure wound therapy (NPWT) with low pressure and a gauze dressing to treat diabetic foot wounds. Thirty patients with diabetic foot wounds were consented to a prospective study to evaluate wound closure and complications to evaluate NPWT with low pressure (80 mmHg) and a gauze dressing interface (EZCare, Smith and Nephew) for up to 5 weeks. NPWT was changed 3 times a week. Study subjects were evaluated once a week for adverse events and wound measurements. Of study subjects, 43% attained at least a 50% wound area reduction after 4 weeks of therapy. Our results suggest that a high rate of wound closure could be expected with low pressure and a gauze interface.  相似文献   
56.
The morbidity and mortality of adult and pediatric chronic kidney disease (CKD) and end‐stage renal disease (ESRD) populations are mainly driven by cardiovascular disease (CVD). Improving CVD outcomes focuses on risk assessment of factors including diastolic blood pressure (DBP), systolic blood pressure (SBP), left ventricular mass index (LVMI), pulse pressure (PP), and pulse pressure index (PPi), which is calculated as PP/SBP. These markers are also proven predictors of CKD progression; however, their role in children has not been established. This study aims to evaluate the relationship between PP, PPi, ambulatory arterial stiffness index (AASI), and proteinuria with kidney function in pediatric CKD patients; it is a retrospective analysis of 620 patients (1‐16 years) from the NIDDK Chronic Kidney Disease in Children (CKiD) registry. The authors analyzed data for three separate cohorts: an overall CKD as well as immunological versus non‐immunological cause for CKD groups. An inverse relationship was found between SBP, DBP, and PP with iGFR and LVMI in the overall CKD group. Our immunological CKD subgroup showed significantly higher serum creatinine, SBP, DBP, and PP values with significantly lower serum albumin levels compared to the non‐immunological group. There were no significant differences with iohexol‐based glomerular filtration rate (iGFR), LVMI, PPi, or high‐sensitivity C‐reactive protein (hs‐CRP) between the two groups. A subgroup analysis demonstrated that SBP, DBP, and PP all correlated significantly with LVMI in the immunological CKD patients but not the non‐immunological subgroup. Additionally, AASI data in the overall CKD population were significantly correlated with PP, PPi, and DBP. This study is one of the first to correlate noninvasive measurements of vascular compliance including PP, PPi, and AASI with iGFR and LVMI in a pediatric CKD cohort. Improving our understanding of surrogate markers for early CVD is integral to improving the care of pediatric CKD population as these patients have yet to develop the hard end points of ESRD, heart failure, myocardial infarction, or stroke.  相似文献   
57.
Poling MC  Kim J  Dhamija S  Kauffman AS 《Endocrinology》2012,153(4):1827-1840
Arginine-phenylalanine-amide (RFamide)-related peptide 3 (RFRP-3, encoded by the Rfrp gene) is the mammalian ortholog of gonadotropin-inhibiting hormone and can inhibit GnRH neuronal activity and LH release. However, the development and regulation of the RFRP-3 system in both sexes is poorly understood. Using in situ hybridization, we examined changes in Rfrp-expressing neurons in mice of both sexes during development and under different adulthood hormonal milieus. We found no sex differences in Rfrp expression or cell number in adult mice. Interestingly, we identified two interspersed subpopulations of Rfrp cells (high Rfrp-expressing, HE; low Rfrp-expressing, LE), which have unique developmental and steroidal regulation characteristics. The number of LE cells robustly decreases during postnatal development, whereas HE cell number increases significantly before puberty. Using Bax knockout mice, we determined that the dramatic developmental decrease in LE Rfrp cells is not due primarily to BAX-dependent apoptosis. In adults, we found that estradiol and testosterone moderately repress Rfrp expression in both HE and LE cells, whereas the nonaromatizable androgen dihydrotestosterone has no effect. Using double-label in situ hybridization, we determined that approximately 25% of Rfrp neurons coexpress estrogen receptor-α in each sex, whereas Rfrp cells do not readily express androgen receptor in either sex, regardless of hormonal milieu. Lastly, when we looked at RFRP-3 receptors, we detected some coexpression of Gpr147 but no coexpression of Gpr74 in GnRH neurons of both intact and gonadectomized males and females. Thus, RFRP-3 may exert its effects on reproduction either directly, via Gpr147 in a subset of GnRH neurons, and/or indirectly, via upstream regulators of GnRH.  相似文献   
58.
59.
The initial macrophage-Leishmania donovani interaction results in the formation of membrane platforms, termed lipid rafts, that help in the entry of the parasite. Therefore, it is imperative that the parasite designs a strategy to modulate its uptake and survival within the macrophages. Herein, we report Leishmania-triggered biphasic ceramide generation. In the first phase, L. donovani promastigotes induce activation of acid sphingomyelinase (ASMase), which catalyzes the formation of ceramide from sphingomyelin. Inhibition of ASMase resulted in reduced uptake and infection with the parasite. In the second phase, de novo synthesis generates ceramide that reduces the cellular cholesterol level and displaces the cholesterol from the membrane, leading to enhanced membrane fluidity, disruption of rafts, and impaired antigen-presentation to the T cells. The results reveal a novel role for ceramide in the perspective of L. donovani infection and help formulate an antileishmanial strategy that can possibly be applied to other intracellular infections as well.  相似文献   
60.
Poor patients in developing countries may not receive permanent pacemakers (PPMs) even as lifesaving measures because of their high cost. In this report we examined whether PPMs that were explanted and donated by funeral homes in the United States could be safely and effectively reused in indigent patients in India. With permission from the deceased patients' families, 121 PPMs were explanted and donated by funeral homes for reuse. These PPMs were sterilized and sent for implantation in needy and indigent patients at a charity hospital in Mumbai, India. From the pool of donated 121 PPMs, 53 (88%, 11 single-chamber PPMs, 21%, and 42 dual-chamber PPMs, 79%) were acceptable for reuse and implanted (37 new implants, 70%, and 16 for battery/generator replacement, 30%) in 53 patients (mean ± SD 64 ± 10 years old, 28 women, 53%). Indications for PPM implantation were complete heart block (n = 27, 51%) and sick sinus syndrome (n = 26, 49%). All patients were alive and well postoperatively. No significant complications including infections or device failures occurred over 19 to 1,827 days (mean 661) of follow-up. Of 40 patients (75%) who were followed locally, 4 (10%) died because of nonpacemaker-related causes; time to death was 121 to 750 days (mean 430) after PPM implantation. All except 2 patients (5%) reported marked improvement in their symptoms. There were only 4 patients (8%) who were previously employed, and all were able to resume their manual labor work. Also, of the women, 27 patients (96%) reported improvement in symptoms enabling them to resume regular household chores as housewives after PPM implantation. In conclusion, with proper device sterilization and handling protocols, reuse of explanted PPMs in poor patients in developing countries is safe and effective. Implantation of donated PPMs can not only save lives but also improve quality of life of needy poor patients.  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