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   9283篇
  免费   707篇
  国内免费   31篇
耳鼻咽喉   124篇
儿科学   209篇
妇产科学   256篇
基础医学   1391篇
口腔科学   154篇
临床医学   836篇
内科学   1984篇
皮肤病学   118篇
神经病学   952篇
特种医学   278篇
外科学   1358篇
综合类   135篇
现状与发展   1篇
一般理论   14篇
预防医学   775篇
眼科学   227篇
药学   524篇
中国医学   8篇
肿瘤学   677篇
  2023年   99篇
  2022年   181篇
  2021年   304篇
  2020年   176篇
  2019年   305篇
  2018年   319篇
  2017年   194篇
  2016年   209篇
  2015年   257篇
  2014年   322篇
  2013年   461篇
  2012年   582篇
  2011年   655篇
  2010年   308篇
  2009年   316篇
  2008年   488篇
  2007年   555篇
  2006年   463篇
  2005年   507篇
  2004年   511篇
  2003年   446篇
  2002年   434篇
  2001年   97篇
  2000年   107篇
  1999年   111篇
  1998年   86篇
  1997年   81篇
  1996年   65篇
  1995年   71篇
  1994年   69篇
  1993年   57篇
  1992年   54篇
  1991年   47篇
  1990年   51篇
  1989年   66篇
  1988年   51篇
  1987年   63篇
  1986年   44篇
  1985年   33篇
  1984年   47篇
  1983年   44篇
  1982年   43篇
  1981年   37篇
  1980年   32篇
  1978年   33篇
  1976年   33篇
  1974年   37篇
  1973年   37篇
  1972年   34篇
  1969年   30篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
There is a deficit of literature regarding the association between nickel allergy–induced symptoms and implanted devices. This report describes a case of nickel allergy causing debilitating migraine-like symptoms, failing to resolve with medical therapy, requiring surgical removal of the device and repair of the defect.  相似文献   
82.
Inactivating mutations in human ecto-nucleotide pyrophosphatase/phosphodiesterase-1 (ENPP1) may result in early-onset osteoporosis (EOOP) in haploinsufficiency and autosomal recessive hypophosphatemic rickets (ARHR2) in homozygous deficiency. ARHR2 patients are frequently treated with phosphate supplementation to ameliorate the rachitic phenotype, but elevating plasma phosphorus concentrations in ARHR2 patients may increase the risk of ectopic calcification without increasing bone mass. To assess the risks and efficacy of conventional ARHR2 therapy, we performed comprehensive evaluations of ARHR2 patients at two academic medical centers and compared their skeletal and renal phenotypes with ENPP1-deficient Enpp1asj/asj mice on an acceleration diet containing high phosphate treated with recombinant murine Enpp1-Fc. ARHR2 patients treated with conventional therapy demonstrated improvements in rickets, but all adults and one adolescent analyzed continued to exhibit low bone mineral density (BMD). In addition, conventional therapy was associated with the development of medullary nephrocalcinosis in half of the treated patients. Similar to Enpp1asj/asj mice on normal chow and to patients with mono- and biallelic ENPP1 mutations, 5-week-old Enpp1asj/asj mice on the high-phosphate diet exhibited lower trabecular bone mass, reduced cortical bone mass, and greater bone fragility. Treating the Enpp1asj/asj mice with recombinant Enpp1-Fc protein between weeks 2 and 5 normalized trabecular bone mass, normalized or improved bone biomechanical properties, and prevented the development of nephrocalcinosis and renal failure. The data suggest that conventional ARHR2 therapy does not address low BMD inherent in ENPP1 deficiency, and that ENPP1 enzyme replacement may be effective for correcting low bone mass in ARHR2 patients without increasing the risk of nephrocalcinosis. © 2021 American Society for Bone and Mineral Research (ASBMR).  相似文献   
83.
Notfall + Rettungsmedizin - In den letzten Jahren hat sich die mechanische Thrombektomie mit Stent-Retrievern als wichtiger Bestandteil der Behandlung des ischämischen Schlaganfalls etabliert....  相似文献   
84.
85.
The article presents a cost-benefit analysis of amniocentesis for detection of chromosomal anomalies based on data (1985/87) collected in the Marseille area. In this geographic area, it is possible to confront, in an exhaustive manner, pregnant women's access to amniocentesis and incidence of fetal anomalies due to chromosomal aberrations. Results show that prenatal diagnosis is highly cost-beneficial, the average cost of one "avoided" case of Down's syndrome being lower than the lifelong costs of care for such a child. However, the study emphasizes that the cost-benefit ratio is highly sensitive to the implicit value society affects to the loss of "normal" fetuses through spontaneous abortions provoked by amniocentesis and because of terminations of pregnancy following diagnosis of minor fetal anomalies. The study also shows that lowering maternal age limit for access to free-of-charge amniocentesis from the current 38 years of age to 35 would have been cost-beneficial. Such lowering of the maternal age limit is discussed and compared with other indications which might be used for systematic access to amniocentesis.  相似文献   
86.
Summary A pharmacokinetic study of randomised crossover design was carried out in which eight patients with recurrent stage pTa or pT1 transitional cell carcinoma of the bladder were given thio TEPA (30 mg) in distilled water or in 10% (v/v) Tween 80 (30 ml) intravesically for 2 h, followed 3 months later by the alternative treatment. Thio TEPA and its primary metabolite, TEPA, were measured in plasma and urine using a sensitive and specific chromatographic assay. Large differences between patients were observed in the proportion of thio TEPA absorbed, ranging from 20%–78%. Peak plasma levels of thio TEPA were observed within 1 h of intravesical administration. By 2 h after administration the plasma levels of TEPA were similar to those of thio TEPA and, in contrast to those of the parent compound, remained at a similar level over the next 4 h. The rate of absorption of thio TEPA was not influenced by Tween 80, but it did cause statistically significant increases in mean peak plasma levels (from 101 to 154 ng/ml) and mean AUC values (from 0.376 to 0.496 g h per ml) and a decrease in the mean half-life (from 1.83 to 1.25 h). To obtain plasma levels similar to those achieved after instillation with thio TEPA alone, the dose should be reduced with Tween 80.  相似文献   
87.
88.
Methods of assessing occupational exposure to diesel exhaust were evaluated in a railroad work environment. The American Conference of Governmental Industrial Hygienists (ACGIH)-recommended elemental carbon and respirable combustible dust methods of sampling and analysis for assessing diesel exhaust were included in the study. A total of 215 personal and area samples were collected using both size-selective (nylon cyclone and Marple) and non-size-selective samplers. The results demonstrate that the elemental carbon method is suitable for the railroad environment and the respirable combustible dust method is not. All elemental carbon concentrations measured were below the proposed ACGIH Threshold Limit Value (TLV) of 0.15 mg/m3. The concentrations of oxides of nitrogen (nitric oxide and nitrogen dioxide) were also found to be below their respective TLVs. There is no correlation between elemental carbon or respirable combustible dust and the oxides of nitrogen. The elemental carbon as fraction of total carbon is about 13 percent, except for onboard locomotives where it is about 24 percent. Comparison of elemental carbon and respirable combustible dust measurements showed consistent relationships for most sampling locations, with respirable combustible dust concentrations 12 to 53 times higher than the elemental carbon levels.  相似文献   
89.
Secretory breast carcinoma is a rare tumor originally described in children and adolescent women with a characteristic morphology and a controversial choice of treatment. We report an additional case of a 4-year-old girl with a breast tumor diagnosed as a secretory carcinoma without involvement of the axillary lymph nodes. The therapy consisted of simple mastectomy and low axillary dissection. She presented with a local recurrence near the surgical scar 8 months later, and a wide elliptical excision of the scar and underlying tissue was performed with subsequent radiotherapy of the surgical bed. This tumor has a relatively benign behavior and rarely metastasizes. A literature review revealed only 22 cases of breast carcinoma in childhood and adolescence. ▪  相似文献   
90.
BACKGROUND: The novel agent sirolimus (SRL; Rapamune; rapamycin) inhibits the immune response by a mechanism distinct from those of calcineurin antagonists or antimetabolites. This randomized, controlled, multicenter, single blind, phase II trial examined the combination of SRL, steroids, and full versus reduced doses of cyclosporine (CsA) for prophylaxis of acute renal allograft rejection. METHODS: A total of 149 recipients of mismatched cadaveric- or living-donor primary renal allografts were randomized into six groups. Three groups received placebo or 1 or 3 mg/m2/day SRL, as well as steroids and full-dose CsA (Sandimmune). Three groups received steroids, reduced-dose CsA (target trough level 50% of full-dose range), and 1, 3, or 5 mg/m2/day SRL. RESULTS: The incidence of biopsy-proven acute rejection episodes within the first 6 months after transplant was reduced from 32.0% in the control group to 8.5% in patients receiving SRL (1 or 3 mg/m2/day) and full-dose Sandimmune CsA (P=0.018). Similar low rates of acute rejection episodes were observed among non-African-Americans, but not African-Americans, treated with SRL and reduced-dose Sandimmune CsA. Despite the augmented immunosuppression, 1-year patient and graft survival rates did not differ significantly across groups. Adverse effects attributable to CsA, including hypertension and new-onset diabetes mellitus, were not exacerbated by SRL. Except for an increased incidence of pneumonia among patients receiving full-dose CsA and 3 mg/m2/day SRL, the incidences of opportunistic infections were similar in all treatment groups. Although SRL produced more frequent, but reversible, hematological and lipid abnormalities, it had no apparent nephrotoxic effects to exacerbate CsA-induced renal dysfunction. CONCLUSIONS: SRL in combination with CsA and steroids not only lowers the incidence of biopsy-proven acute renal allograft rejection episodes, but also may permit CsA sparing, at least among Caucasian patients, without an increased risk of rejection.  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