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   7077篇
  免费   317篇
  国内免费   51篇
耳鼻咽喉   37篇
儿科学   207篇
妇产科学   40篇
基础医学   1033篇
口腔科学   148篇
临床医学   358篇
内科学   1927篇
皮肤病学   94篇
神经病学   407篇
特种医学   264篇
外科学   1272篇
综合类   22篇
预防医学   215篇
眼科学   80篇
药学   493篇
中国医学   23篇
肿瘤学   825篇
  2023年   31篇
  2022年   93篇
  2021年   163篇
  2020年   87篇
  2019年   123篇
  2018年   136篇
  2017年   114篇
  2016年   161篇
  2015年   165篇
  2014年   232篇
  2013年   274篇
  2012年   428篇
  2011年   459篇
  2010年   267篇
  2009年   260篇
  2008年   450篇
  2007年   466篇
  2006年   434篇
  2005年   461篇
  2004年   423篇
  2003年   416篇
  2002年   423篇
  2001年   113篇
  2000年   97篇
  1999年   99篇
  1998年   121篇
  1997年   99篇
  1996年   71篇
  1995年   65篇
  1994年   60篇
  1993年   61篇
  1992年   62篇
  1991年   73篇
  1990年   71篇
  1989年   48篇
  1988年   48篇
  1987年   35篇
  1986年   32篇
  1985年   31篇
  1984年   21篇
  1983年   24篇
  1982年   16篇
  1981年   18篇
  1980年   12篇
  1979年   9篇
  1978年   10篇
  1977年   14篇
  1976年   12篇
  1971年   7篇
  1970年   7篇
排序方式: 共有7445条查询结果,搜索用时 15 毫秒
61.
Although tacrolimus (TAC) has remarkable effects in ulcerative colitis (UC) patients when given as remission induction therapy, some can develop renal dysfunction during TAC administration, resulting in withdrawal, though related details remain poorly understood. This study was conducted to determine the impact of oral TAC on renal function for remission induction therapy in UC patients. Fifty-five patients (10 elderly, 45 non-elderly) with UC and treated with oral TAC at our hospital were retrospectively evaluated. Renal function was assessed using estimated glomerular filtration rate (eGFR). Although a high clinical response to TAC was seen in both elderly and non-elderly, a decline in eGFR was noted in nearly all patients regardless of age, with a maximum change of −34.4% from the baseline value at week 11. Furthermore, eGFR decline recovered quickly after TAC discontinuation, though did not return to the baseline at two years following cessation. The rate of eGFR change at week 12 was significantly associated with patient age (β = −0.3242, p = 0.0103) and peak serum trough level during TAC treatment (β = 0.3563, p = 0.0051). Furthermore, the rate of decline in eGFR was significantly greater during treatment with TAC in the elderly as compared to non-elderly, with a large difference in eGFR decline rate between those groups also noted at two years after withdrawal of treatment. Careful attention to renal function when administering oral TAC for UC is important and changes in eGFR should be monitored closely in elderly patients even after treatment cessation.  相似文献   
62.
In order to determine whether 5-[bis(carboxymethyl) amino]-2-carboxy4-cyano-3-thiopheneacetic acid distrontium salt (S12911-2) inhibits bone resorption by acting on the differentiation and/or function of osteoclasts, its effects were assessed on the 1,25-dihydroxyvitamin D(3)-induced expression of carbonic anhydrase II and vitronectin receptor in chicken bone marrow cells, and on the resorbing activity of authentic rat osteoclasts cultured on bone slices. S12911-2 dose-dependently inhibited, after a 6-day exposure, the expression of carbonic anhydrase II and vitronectin receptor in stimulated osteoclasts (46% and 40%, respectively, at 10(-3) M Sr(2+), P<0.05). A pre-incubation of bone slices with S12911-2 induced a dose-dependent inhibition of bone resorbing activity from 32% at 10(-4) M Sr(2+) to 66% at 10(-3) M Sr(2+) (P<0.05 in each case). A continuous incubation (10(-3) M Sr(2+)) induced a greater inhibition of bone resorbing activity (73%, P<0.05). The inhibition of bone resorption obtained specifically with S12911-2 is related to an inhibition of the differentiation and resorbing activity of the osteoclasts.  相似文献   
63.
Material and methods We analyzed the expression of hypoxia inducible factor-1α (HIF-1α) and glucose transporter-1 (GLUT-1) by immunohistochemistry in ovarian serous and mucinous tumors from the point view of the histological characteristics and acquisition of malignancy. A total of 102 ovarian tumors were examined, composed of 31 adenomas (serous 17 and mucinous 14), 32 borderline tumors (serous 13 and mucinous 19), and 39 adenocarcinomas (serous 21 and mucinous 18). Results The overall positive ratios were as follows: HIF-1α, 74% of adenomas, 91% of borderline tumors, and 100% of adenocarcinomas; and GLUT-1, 68% of adenomas, 95% of borderline tumors, and 100% of adenocarcinomas. Comparing serous tumors and mucinous tumors, there was no significant difference in the positive ratios of HIF-1α and GLUT-1 of adenomas, borderline tumors, and adenocarcinomas. However, both markers were more strongly expressed in serous adenocarcinomas (HIF-1α, 3 + 100%; GLUT-1, 3 + 76%) than in mucinous adenocarcinomas (HIF-1α, 3 + 61%; GLUT-1, 3 + 28%). The results of immunoblotting and mRNA expression level analyses corresponded with those of immunohistochemical expression profiles. DNA binding assay also demonstrated that HIF-1 is more commonly activated in serous adenocarcinomas than in mucinous adenocarcinomas. Conclusion HIF-1α and GLUT-1 expressions seemed to be coordinated to adapt ovarian tumor cells into hypoxic conditions in close association with the acquisition of malignancy. We consider that the relatively strong expression of both markers in serous tumors compared with mucinous tumors is related to the difference in their histological characteristics.  相似文献   
64.
Immune checkpoint inhibitors (ICIs), which have anti-tumor effects, are currently approved for treatment of several kinds of advanced malignancies. However, with their increasing use, a variety of immune-related adverse events (irAEs) in administered patients have been reported. We herein report a rare case of the simultaneous onset of acute pancreatitis and colitis as irAEs during nivolumab treatment given to a patient with renal cell carcinoma, who then shown marked improvement with corticosteroid therapy.  相似文献   
65.
Sialyl-Tn (STn), overexpressed on various tumors, has been investigated for its application in anti-cancer vaccine therapy. However, Theratope, an STn-based vaccine, failed in the phase III clinical trial due to poor immunogenicity and epitope suppression by the foreign carrier protein. We therefore developed a self-adjuvanting STn based-vaccine, a conjugate of clustered STn (triSTn) antigen, TLR1/2 ligand (Pam3CSK4), and T-helper (Th) cell epitope, and found that this three-component self-adjuvanting vaccine effectively resulted in the production of anti-triSTn IgG antibodies. We herein analyzed immune responses induced by this self-adjuvanting vaccine in detail. We newly synthesized two-component vaccines, i.e., Pam3CSK4- or Th epitope-conjugated triSTn, as references to evaluate the immune-stimulating functions of Pam3CSK4 and Th epitope. Immunological evaluation of the synthesized vaccine candidates revealed that Pam3CSK4 was essential for antibody production, indicating that the uptake of triSTn antigen by antigen-presenting cells (APCs) was promoted by the recognition of Pam3CSK4 by TLR1/2. The function of the Th epitope was also confirmed. Th cell activation was important for boosting antibody production and IgG subclass switching. Furthermore, flow cytometric analyses of immune cells, including T cells, B cells, dendritic cells, and other monocytes, were first employed in the evaluation of self-adjuvanting vaccines and revealed that the three-component vaccine was able to induce antigen-specific immune responses for efficient antibody production without excessive inflammatory responses. Importantly, the co-administration of Freund''s adjuvants was suggested to cause excessive myeloid cell accumulation and decreased plasma cell differentiation. These results demonstrate that vaccines can be designed to achieve the desired immune responses via the bottom-up construction of each immune element.

Detailed analysis of a three-component self-adjuvanting vaccine revealed that conjugate vaccines can be designed to achieve the desired immune responses via bottom-up construction of the necessary immune elements.  相似文献   
66.
67.
The development of diabetic nephropathy shows remarkable variation among individuals. Therefore, not only hyperglycemia but also genetic factors may contribute to the development of diabetic nephropathy Heparan sulfate proteoglycan (HSPG) is thought to play an important role as a component of the charge selectivity barrier in the glomerular basement membrane. Recently, a BamHI restriction fragment length polymorphism (RFLP) in the HSPG gene (HSPG2) was reported to be associated with diabetic nephropathy in Caucasian insulin-dependent diabetes mellitus (IDDM). The aim of the present study was to examine the contribution of the BamHI HSPG2 polymorphism to the development of diabetic nephropathy in Japanese non-insulin-dependent diabetes mellitus (NIDDM). For this purpose, we recruited 102 patients with diabetic nephropathy and 64 age-matched patients without diabetic nephropathy from Japanese NIDDM patients. Since all the subjects had proliferative diabetic retinopathy, it seems likely that they would be exposed to hyperglycemia for a long time. In the present study, the BamHI HSPG2 genotype and allele frequencies were not significantly different between the patients with nephropathy and the patients without nephropathy. Therefore, we conclude that the BamHI HSPG2 polymorphism is not associated with the development of diabetic nephropathy in Japanese NIDDM.  相似文献   
68.
Most cases of thoracic outlet syndrome are detected by neulogical symptoms, and most of the other symptoms are caused by arterial stenosis. It is rare for the syndrome to be recognized by venous symptoms. We report a 56-year-old woman with thoracic outlet syndrome recognized by arm swelling. She was admitted for radiation therapy of a recurrent tumor of lung cancer at the left apex. Her right arm gradually became swollen. We performed venography from the right median cubital vein because of suspected venous thrombosis. Venography revealed stenosis of the right subclavian vein at the costoclavicular space, and this finding was confirmed by helical CT. These findings strongly support our diagnosis of thoracic outlet syndrome.  相似文献   
69.
The aim of this study was to evaluate the clinical usefulness of attenuation and scatter correction (AC, SC) on a 201Tl myocardial single-photon emission computed tomography (201Tl SPECT) as a multi-center trial. With a dual-detecter and a triple-detector SPECT systems with a 99mTc transmission source, simultaneous transmission/emission tomography (TCT/ECT) was performed on 38 patients with angiographically coronary heart disease (CHD) and 26 patients without evidence of CHD. Stress and delayed attenuation and scatter corrected images (SAC) and uncorrected images (NC) were reconstructed. On NC images of normal cases, influence of attenuation was greater in male than female. In comparison of 201Tl distribution between male and female, significant decrease in 201Tl activity was observed in the inferoposterior wall in male and that was observed in the anterobasal wall of the left myocardium in female. Such a difference in 201Tl distribution between male and female disappeared on SAC images. On the diagnostic performance for the identification of CHD, SAC images demonstrated improved specificity and accuracy values in the right coronary arterial territory (RCA) with visual analysis statistically. Sensitivity value in the RCA was also improved, but it was not statistically significant. Sensitivity value in the left circumflex arterial territory (LCX) increased without decrease in specificity value on SAC images. In the left anterior descending arterial territory (LAD), sensitivity value increased on SAC images. Although specificity value decreased on SAC images in LAD territory, it was not statistically significant. The difference in 201Tl distribution between male and female is improved in normal cases by attenuation and scatter correction on 201Tl myocardial SPECT. Diagnostic performance of CHD is also improved by attenuation and scatter correction, especially in territories of which specificity in assessing the absence of disease have been suboptimal. In conclusion, attenuation and scatter correction on 201Tl myocardial SPECT is considered to be clinically useful.  相似文献   
70.
BACKGROUND: The high proportions of lymphoid tissues are thought to be one of the underlying factors inducing severe allograft rejection following small bowel transplantation. Mesenteric lymph nodes (MLN) contained in the intestinal graft are not only a source of donor-derived professional antigen-presenting cells, but also offer a field for immune interaction between donor and host cells. We investigated immune responses in graft MLNs with or without FK506 to develop a novel strategy to control small bowel allograft rejection. MATERIALS AND METHODS: Heterotopic small bowel transplantations were performed from Brown Norway donors to Lewis recipients. Changes in population of lymphocytes, expressions of costimulatory molecules, apoptosis, and cytokine profiles in graft MLNs were evaluated. RESULTS: The increase in apoptotic cells and cytokine responses relating to rejection in the graft MLNs developed prior to those in graft jejunum. While donor lymphocytes in graft MLNs were rapidly replaced to host-derived lymphocytes independent of FK treatment, increase in CD8(+) T cells in host population was seen only in recipients without FK506 treatment. The expressions of B7 molecules on donor cells in graft MLNs were significantly lower in the recipients with FK treatment. CONCLUSIONS: Immune responses in graft MLNs have significant impact on the outcome of the small bowel allograft. Apoptosis of graft MLN cells was well correlated with and ahead of progression of acute rejection. Modulation of costimulatory molecules on donor-derived MLN cells in the allograft and specific suppression of host CD8(+) T cells are possible ways to control severe rejection after allogeneic small bowel transplantation.  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