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   2483篇
  免费   143篇
  国内免费   20篇
耳鼻咽喉   32篇
儿科学   79篇
妇产科学   49篇
基础医学   384篇
口腔科学   52篇
临床医学   209篇
内科学   622篇
皮肤病学   101篇
神经病学   219篇
特种医学   43篇
外科学   194篇
综合类   8篇
预防医学   221篇
眼科学   37篇
药学   199篇
中国医学   10篇
肿瘤学   187篇
  2024年   5篇
  2023年   33篇
  2022年   58篇
  2021年   132篇
  2020年   51篇
  2019年   95篇
  2018年   103篇
  2017年   73篇
  2016年   70篇
  2015年   76篇
  2014年   92篇
  2013年   140篇
  2012年   190篇
  2011年   215篇
  2010年   105篇
  2009年   82篇
  2008年   157篇
  2007年   146篇
  2006年   144篇
  2005年   143篇
  2004年   135篇
  2003年   121篇
  2002年   110篇
  2001年   12篇
  2000年   5篇
  1999年   12篇
  1998年   23篇
  1997年   10篇
  1996年   13篇
  1995年   12篇
  1994年   4篇
  1993年   5篇
  1992年   5篇
  1990年   3篇
  1989年   3篇
  1988年   3篇
  1987年   5篇
  1985年   5篇
  1984年   4篇
  1983年   3篇
  1981年   4篇
  1980年   4篇
  1978年   2篇
  1977年   3篇
  1975年   2篇
  1973年   3篇
  1972年   3篇
  1971年   3篇
  1969年   2篇
  1927年   3篇
排序方式: 共有2646条查询结果,搜索用时 66 毫秒
91.
Early non-haematological toxicity of high dose therapy (HDT) and autologous haematopoietic cell transplantation (autoHCT) can be more hazardous in older patients (pts) with comorbidities. The aim of the study was to analyze incidence and grade of the organ-related early complications up to 30 days post-transplant period in elderly lymphoma patients. Between January 2005 and November 2011, 44 consecutive lymphoma pts underwent HDT followed by autoHCT. Median age of pts was 62 years (range 60–67). Conditioning regimens were: BEAM(carmustine, etoposide, cytarabine, melphalan) in 16, melphalan 200 in 22, cytarabine, melphalan or cyclophosphamide – in 6 pts. 32% pts had comorbidities: in 71% cardiovascular. Early non-haematologic complications within 30 days after autoHCT were reported in 84% of pts. The most common events were gastrointestinal (77%): 55% pts had prolonged (more than 7 days) diarrhoea grade III—IV, nausea and vomiting occurred in 40% of pts, 50% of pts demonstrated mucositis (grade III—IV in 34% of pts). Neutropenic fever was reported in 59% of pts with sepsis in 1.9% of pts. Cardiac events occurred in 9% of pts. Median hospitalization was 21 days (range 16—45). One patient died from transplanted related toxicity. HDT resulted in high incidence of non-hematologic toxicity in elderly patients during early post-transplant period. The toxicity of this procedure is acceptable, with mortality rate of only 2% in the elderly transplanted patients. The most common toxicities were: neutropenic fever, gastrointestinal toxicity and cardiac complications  相似文献   
92.
Surgical aortic valve replacement (AVR) still remains the treatment of choice in symptomatic significant aortic stenosis (AS). Due to technical problems, extensive calcification of the ascending aorta (“porcelain aorta”) is an additional risk factor for surgery and transapical aortic valve implantation (TAAVI) is likely to be the only rescue procedure for this group of patients. We describe the case of an 81-year-old woman with severe AS and “porcelain aorta”, in whom the only available life-saving intervention was TAAVI.  相似文献   
93.
Infection with HIV-1 frequently results in the loss of specific cellular immune responses and an associated lack of antibodies. Recombinant growth hormone (rGH) administration reconstitutes thymic tissue and boosts the levels of peripheral T cells, so rGH therapy may be an effective adjuvant through promoting the recovery of lost cellular and T-cell-dependent humoral immune responses in immunosuppressed individuals. To test this concept, we administered rGH to a clinically defined group of HIV-1-infected subjects with defective cellular and serological immune responses to at least one of three commonly employed vaccines (hepatitis A, hepatitis B or tetanus toxoid). Of the original 278 HIV-1-infected patients entering the trial, only 20 conformed to these immunological criteria and were randomized into three groups: Group A (n = 8) receiving rGH and challenged with the same vaccine to which they were unresponsive and Groups B (n = 5) and C (n = 7) who received either rGH or vaccination alone, respectively. Of the eight subjects in Group A, five recovered CD4 cellular responses to vaccine antigen and four of these produced the corresponding antibodies. In the controls, three of the five in group B recovered cellular responses with two producing antibodies, whereas three of the seven in Group C recovered CD4 responses, with only two producing antibodies. Significantly, whereas seven of ten patients receiving rGH treatment in Group A (six patients) and B (one patient) recovered T-cell responses to HIVp24, only two of six in Group C responded similarly. In conclusion, reconstitution of the thymus in immunosuppressed adults through rGH hormone treatment restored both specific antibody and CD4 T-cell responses.  相似文献   
94.
The treatment of microcystin-LR (MCYST-LR)-induced lung inflammation has never been reported. Hence, LASSBio 596, an anti-inflammatory drug candidate, designed as symbiotic agent that modulates TNF-α levels and inhibits phosphodiesterase types 4 and 5, or dexamethasone were tested in this condition. Swiss mice were intraperitoneally (i.p.) injected with 60 μl of saline (CTRL) or a sub-lethal dose of MCYST-LR (40 μg/kg). 6 h later they were treated (i.p.) with saline (TOX), LASSBio 596 (10 mg/kg, L596), or dexamethasone (1 mg/kg, 0.1 mL, DEXA). 8 h after MCYST-LR injection, pulmonary mechanics were determined, and lungs and livers prepared for histopathology, biochemical analysis and quantification of MCYST-LR. TOX showed significantly higher lung impedance than CTRL and L596, which were similar. DEXA could only partially block the mechanical alterations. In both TOX and DEXA alveolar collapse and inflammatory cell influx were higher than in CTRL and L596, being LASSBio 596 more effective than dexamethasone. TOX showed oxidative stress that was not present in CTRL and L596, while DEXA was partially efficient. MCYST-LR was detected in the livers of all mice receiving MCYST-LR and no recovery was apparent. In conclusion, LASSBio 596 was more efficient than dexamethasone in reducing the pulmonary functional impairment induced by MCYST-LR.  相似文献   
95.
The discovery and study of neural stem cells have revolutionized our understanding of the neurogenetic process, and their inherent ability to adopt expansive growth behavior in vitro is of paramount importance for the development of novel therapeutics based on neural cell replacement. Recent advances in high-throughput assays for drug development and gene discovery dictate the need for rapid, reproducible, long-term expansion of human neural stem cells (hNSCs). In this view, the complement of wild-type cell lines currently available is insufficient. Here we report the establishment of a stable human neural stem cell line (immortalized human NSCs [IhNSCs]) by v-myc-mediated immortalization of previously derived wild-type hNSCs. These cells demonstrate three- to fourfold faster proliferation than wild-type cells in response to growth factors but retain rather similar properties, including multipotentiality. By molecular biology, biochemistry, immunocytochemistry, fluorescence microscopy, and electrophysiology, we show that upon growth factor removal, IhNSCs completely downregulate v-myc expression, cease proliferation, and differentiate terminally into three major neural lineages: astrocytes, oligodendrocytes, and neurons. The latter are functional, mature cells displaying clear-cut morphological and physiological features of terminally differentiated neurons, encompassing mostly the GABAergic, glutamatergic, and cholinergic phenotypes. Finally, IhNSCs produce bona fide oligodendrocytes in fractions up to 20% of total cell number. This is in contrast to the negligible propensity of hNSCs to generate oligodendroglia reported so far. Thus, we describe an immortalized hNSC line endowed with the properties of normal hNSCs and suitable for developing the novel, reliable assays and reproducible high-throughput gene and drug screening that are essential in both diagnostics and cell therapy studies.  相似文献   
96.
A new immunoenzymatic test, named the thin-layer immunoassay–enzyme-linked immunosorbent assay (TIA-ELISA), was evaluated for antibody detection in human trichinellosis using excretion and secretion products prepared from Trichinella spiralis muscle larvae. Serum samples from people with positive muscle biopsies or symptoms compatible with the disease (n = 8 or 26, respectively), all reactive in enzyme-linked immunoelectrotransfer blot assay (EITB), as well as 67 serum samples from healthy, EITB-negative people, were tested in an ELISA and TIA-ELISA. TIA-ELISA was performed in polystyrene plastic petri dishes by adding dots of 10 μl each of antigen (7 μg/ml) followed by adding diluted serum and the conjugate. Finally, the substrate mixed with agar was added to develop the reaction. Enzymatic by-products were easily detected by the naked eye as defined dots. Sensitivity and specificity were 76 and 94% for ELISA, and both parameters were 91% for TIA-ELISA. The kappa correlation indices for both tests in relation to EITB were 0.73 and 0.80, respectively. The TIA-ELISA can be carried out with common laboratory equipment in 3 h and uses lower quantities of antigen than EITB and ELISA. Since TIA-ELISA is easy to perform, cheap, sensitive, and specific, the test could be an acceptable alternative to use in clinical laboratories lacking specialized equipment needed for ELISA and EITB and in field studies for antibody detection in human trichinellosis.  相似文献   
97.
Several reports have brought to light new and interesting findings on the involvement of autophagy and apoptosis in pathogenesis of viral and bacterial diseases, as well as presentation of foreign antigens. Our model studies focused on the involvement of apoptosis during replication of highly virulent Moscow strain of ectromelia virus (ECTV-MOS). Here, we show evidence that autophagy is induced during mousepox replication in a cell line. Fluorescence microscopy revealed increase of LC3 (microtubule-associated protein 1 light chain 3) aggregation in infected as opposed to non-infected control L929 cells. Furthermore, Western blot analysis showed that replication of ECTV-MOS in L929 cells led to the increase in LC3-II (marker of autophagic activity) expression. Beclin 1 strongly colocalized with extranuclear viral replication centers in infected cells, whereas expression of Bcl-2 decreased in those centers as shown by fluorescence microscopy. Loss of Beclin 1-Bcl-2 interaction may lead to autophagy in virus-infected L929 cells. To assess if Beclin 1 has a role in regulation of apoptosis during ECTV-MOS infection, we used small interfering RNA directed against beclin 1 following infection. Early and late apoptotic cells were analyzed by flow cytometry after AnnexinV and propidium iodide staining. Silencing of beclin 1 resulted in decreased percentage of early and late apoptotic cells in the late stage of ECTV-MOS infection in L929 cells. We conclude that Beclin 1 plays an important role in regulation of both, autophagy and apoptosis, during ECTV-MOS replication in L929 permissive cells.  相似文献   
98.
BackgroundThis is the first-in-human study of icenticaftor, an oral potentiator of the cystic fibrosis (CF) transmembrane conductance regulator (CFTR) channel. Restoration of CFTR activity has shown significant clinical benefits, but more studies are needed to address all CFTR mutations.MethodsSafety, pharmacodynamics/pharmacokinetics of icenticaftor were evaluated in a randomized, double-blind, placebo-controlled study in healthy volunteers. Efficacy was assessed in adult CF patients with ≥1 pre-specified CFTR Class III or IV mutation (150 and 450 mg bid), or homozygous for F508del mutation (450 mg bid). Primary efficacy endpoint was change from baseline in lung clearance index (LCI2.5). Secondary endpoints included %predicted FEV1 and sweat chloride level.ResultsClass IV mutations were present in 22 patients, Class III in 2 (both S549N), and 25 were homozygous for F508del. Icenticaftor was well-tolerated in healthy and CF subjects with no unexpected events or discontinuations in the CF groups. The most frequent study-drug related adverse events in CF patients were nausea (12.2%), headache (10.2%), and fatigue (6.1%). Icenticaftor 450 mg bid for 14 days showed significant improvements in all endpoints versus placebo in patients with Class III and IV mutations; mean %predicted FEV1 increased by 6.46%, LCI2.5 decreased by 1.13 points and sweat chloride decreased by 8.36 mmol/L. No significant efficacy was observed in patients homozygous for a single F508del.ConclusionsIcenticaftor was safe and well-tolerated in healthy volunteers and CF patients, and demonstrated clinically meaningful changes in lung function and sweat chloride level in CF patients with Class III and IV CFTR mutations.ClinicalTrials.gov: NCT02190604  相似文献   
99.
100.

Background

A low protein diet (LPD) with essential amino acid ketoanalogue supplementation (KA) may contribute in improving of chronic kidney disease (CKD), while the exact mechanisms of KA’s effect are not established yet. We have conducted a prospective, randomized, controlled comparative study of LPD?+?KA and LPD alone in relation to serum Klotho, FGF-23 levels in CKD patients.

Methods

79 non-diabetic CKD 3b–4 stage patients, compliant with LPD diet (0.6 g/kg of body weight/day), had been selected. The patients were randomized into two groups. The first group (42 patients) received LPD + КA. The second group (37 patients) continued the LРD alone. In addition to routine tests, serum Klotho, FGF-23 levels, as well as bioimpedance analysis, sphygmography (stiffness (augmentation) indices (AI), central (aortal) blood pressure) with a «SphygmaCor» device; echocardiography (valvular calcification score (VCS) and LVMMI), were performed.

Results

There were body mass indices’ decrease (p?=?0.046), including muscle body mass in men (p?=?0.027) and woman (p?=?0.044) in the LPD group to the end of study (14th month). In addition, lower FGF-23 (p?=?0.029), and higher sKlotho (p?=?0.037) were detected in the LPD?+?KA group compared to the LPD one. The increase in AI (p?=?0.034), VCS (p?=?0.048), and LVMMI (p?=?0.023) was detected more often in the LPD group at the end of study.

Conclusion

LPD?+?KA provides support for nutrition status and contributes to more efficient correction of FGF-23 and Klotho abnormalities that may result in cardiovascular calcification and cardiac remodeling decreasing in CKD. At the same time, a prolonged LPD alone may lead to malnutrition.
  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