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   2962篇
  免费   167篇
  国内免费   7篇
耳鼻咽喉   11篇
儿科学   154篇
妇产科学   76篇
基础医学   251篇
口腔科学   118篇
临床医学   202篇
内科学   598篇
皮肤病学   161篇
神经病学   116篇
特种医学   73篇
外科学   368篇
综合类   82篇
一般理论   2篇
预防医学   119篇
眼科学   261篇
药学   346篇
  2篇
中国医学   12篇
肿瘤学   184篇
  2023年   14篇
  2022年   60篇
  2021年   99篇
  2020年   53篇
  2019年   71篇
  2018年   90篇
  2017年   58篇
  2016年   82篇
  2015年   79篇
  2014年   120篇
  2013年   168篇
  2012年   236篇
  2011年   205篇
  2010年   155篇
  2009年   133篇
  2008年   189篇
  2007年   215篇
  2006年   167篇
  2005年   169篇
  2004年   140篇
  2003年   96篇
  2002年   129篇
  2001年   50篇
  2000年   27篇
  1999年   41篇
  1998年   43篇
  1997年   22篇
  1996年   19篇
  1995年   17篇
  1994年   17篇
  1993年   13篇
  1992年   13篇
  1991年   10篇
  1990年   19篇
  1989年   14篇
  1988年   14篇
  1987年   16篇
  1986年   5篇
  1985年   17篇
  1984年   7篇
  1983年   5篇
  1982年   4篇
  1980年   7篇
  1979年   2篇
  1976年   5篇
  1975年   2篇
  1973年   9篇
  1972年   2篇
  1970年   3篇
  1965年   1篇
排序方式: 共有3136条查询结果,搜索用时 15 毫秒
71.
Arrangement of artificial teeth in a bilaterally symmetrical fashion with proper inclinations of teeth had been a challenging task for beginners. A variety of tools and guiding equipment have been developed to help students to learn teeth arrangement. Unfortunately, those tools were either costly or unsuitable for use with mean value articulators. This article attempts to introduce a simplified clinometer which can be attached to mean value articulator and can be used as a guide to arrange teeth in a bilaterally symmetrical manner by the undergraduates in both clinical and preclinical set-up. CLINICAL SIGNIFICANCE: Training of the future dentists in sound esthetic principles in a preclinical environment, using this device, will increase the final clinical efficacy of their work. AIM: The aim of this article is to provide a simple but effective device to undergraduate students to help them learn teeth arrangement easily and systematically.  相似文献   
72.
BACKGROUND: Trichodiscomas are rare hamartomas of the dermal portion of the hair disc, a specialized component of the perifollicular mesenchyme. They are usually found as asymptomatic multiple skin-colored papules on the face and extremities and may have an autosomal dominant inheritance pattern. However, a solitary variant has been described. CASE REPORT: A 78-year-old woman presented with a single, non-pigmented, firm papule on the left tip of the nose, measuring 3.5 mm in diameter. RESULTS: The histological examination revealed the previously described features of a trichodiscoma. The immunohistochemical analysis showed strong immunoreactivity for CD34 in the spindle cell component. Spindle cells were negative for S-100, HMB-45, Melan-A, EMA, neurofilament, desmin, and Factor XIIIa by immunohistochemistry. CONCLUSIONS: We report strong reactivity for CD34 in the spindle cell component of a trichodiscoma. We suggest that this lesion be considered in the differential diagnosis of any CD34+ dermal spindle cell proliferation, in which an adjacent epithelial component cannot be entirely excluded.  相似文献   
73.
74.
Diethylcarbamazine in bronchial asthma   总被引:1,自引:0,他引:1  
  相似文献   
75.
76.
Secretion and progressive cerebral accumulation of beta-amyloid peptides (A beta), which derive by endoproteolytic ('amyloidogenic') processing of beta-amyloid precursor protein (APP), are felt to represent collectively an early and necessary event in the pathogenesis of Alzheimer's disease. APP amyloidogenic processing can occur via secretory or endocytotic pathways, but the relative contribution of these pathways to A beta secretion remains to be established. The effect of apoptosis on amyloidogenic processing and A beta secretion similarly is incompletely understood. We tested the hypothesis that APP processing by the endocytotic pathway represents a stress-related neural cell response, by comparing A beta secretion after induction of apoptosis in PC12 cells transfected either for endocytosis-competent or -deficient APP. Newly prepared adenoviral vectors encompassing targeted mutagenesis of the cytoplasmic tail YENP tetrapeptide sequence, which serves as the principal APP internalization signal, were used to express endocytosis-deficient holoprotein. We report that the endocytotic pathway is required for the generation and secretion of A beta 42, and that secretion of this neurotoxic peptide increases significantly during apoptosis. We demonstrate additionally that more A beta 40 apparently is generated in secretory compartments during apoptosis when APP processing by the endocytotic pathway is impaired.  相似文献   
77.
In vitro hemocompatibility testing of UV-modified hyaluronan hydrogels   总被引:2,自引:0,他引:2  
Hydrogels (hylans) based on cross-linked hyaluronan (HA) are potentially good biomaterials for vascular tissue engineering applications because they are highly non-antigenic and -immunogenic. To facilitate surface endothelialization, vital to vascular deployment, we irradiated the gel surface with low wavelength UV light. This process micro-textures the smooth gel surface to provide sites for cell anchorage and causes limited scission of native long-chain HA yielding smaller fragments that elicit an enhanced cell response. In the current in vitro study, we assessed the effects of UV irradiation on the short-term (<45 min) interaction between hylan gels and human blood cells (RBCs, platelets) and coagulation proteins at physiologic temperature. Although the lowered hydrophilicity of irradiated (UV) hylans elicited greater vascular cell response relative to unmodified (U) hylans, platelet deposition was unaffected and much lower compared to collagen-coated glass controls. The adhered platelets were rounded or mildly pseudopodic and did not express p-selectin, an activation marker. Both gel types induced identical, and minimal platelet release as measured using an platelet factor 4 ELISA, and identically deferred the intrinsic and extrinsic coagulation pathways. Both gel types induced elevated levels of contact activation of bound, but not plasma-phase factor XII relative to controls. Hemolysis rates were also identical and within accepted standards. We conclude that UV-treatment of hylans, useful to improve surface endothelialization, does not compromise their short-term hemocompatibility, vital to their use as vascular implant materials.  相似文献   
78.

Background  

The leaf juice or water decoction of Catharanthus roseus L. (Apocyanaceae) is used as a folk medicine for the treatment of diabetes all over the world. In the present investigation, the leaf juice of C. roseus has been evaluated for its hypoglycemic activity in normal and alloxan-induced diabetic rabbits.  相似文献   
79.

Objective

Uterine Papillary Serous Carcinoma (UPSC) is uncommon and accounts for less than 5% of all uterine cancers. Therefore the majority of evidence about the benefits of adjuvant treatment comes from retrospective case series. We conducted a prospective multi-centre non-randomized phase 2 clinical trial using four cycles of adjuvant paclitaxel plus carboplatin chemotherapy followed by pelvic radiotherapy, in order to evaluate the tolerability and safety of this approach.

Methods

This trial enrolled patients with newly diagnosed, previously untreated patients with stage 1b-4 (FIGO-1988) UPSC with a papillary serous component of at least 30%. Paclitaxel (175 mg/m2) and carboplatin (AUC 6) were administered on day 1 of each 3-week cycle for 4 cycles. Chemotherapy was followed by external beam radiotherapy to the whole pelvis (50.4 Gy over 5.5 weeks). Completion and toxicity of treatment (Common Toxicity Criteria, CTC) and quality of life measures were the primary outcome indicators.

Results

Twenty-nine of 31 patients completed treatment as planned. Dose reduction was needed in 9 patients (29%), treatment delay in 7 (23%), and treatment cessation in 2 patients (6.5%). Hematologic toxicity, grade 3 or 4 occurred in 19% (6/31) of patients. Patients' self-reported quality of life remained stable throughout treatment. Thirteen of the 29 patients with stages 1-3 disease (44.8%) recurred (average follow-up 28.1 months, range 8-60 months).

Conclusion

This multimodal treatment is feasible, safe and tolerated reasonably well and would be suitable for use in multi-institutional prospective randomized clinical trials incorporating novel therapies in patients with UPSC.  相似文献   
80.
Febrile-range hyperthermia (FRH) improves survival in experimental infections by accelerating pathogen clearance, but may also increase collateral tissue injury. We hypothesized that FRH would worsen the outcome of inflammation stimulated by a non-replicating agonist and tested this hypothesis in a murine model of pulmonary oxygen toxicity. Using a conscious, temperature-controlled mouse model, we showed that maintaining a core temperature at FRH (39 degrees C to 40 degrees C) rather than at euthermic levels (36.5 degrees C to 37 degrees C) during hyperoxia exposure accelerated lethal pulmonary vascular endothelial injury, reduced the inspired oxygen threshold for lethality, induced expression of granulocyte-colony stimulating factor, and expanded the circulating neutrophil pool. In these same mice, FRH augmented pulmonary expression of the ELR(+) CXC chemokines, KC and LPS-induced CXC chemokine, enhanced recruitment of neutrophils, and changed the histological pattern of lung injury to a neutrophilic interstitial pneumonitis. Immunoblockade of CXC receptor-2 abrogated neutrophil recruitment, reduced pulmonary vascular injury, and delayed death. These combined data demonstrate that FRH may enlist distinct mediators and effector cells to profoundly shift the host response to a defined injurious stimulus, in part by augmenting delivery of neutrophils to sites of inflammation, such as may occur in infections. In certain conditions, such as in the hyperoxic lung, this process may be deleterious.  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