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   1164篇
  免费   84篇
  国内免费   11篇
耳鼻咽喉   14篇
儿科学   16篇
妇产科学   8篇
基础医学   169篇
口腔科学   46篇
临床医学   92篇
内科学   360篇
皮肤病学   17篇
神经病学   63篇
特种医学   52篇
外科学   182篇
综合类   8篇
预防医学   33篇
眼科学   2篇
药学   60篇
中国医学   1篇
肿瘤学   136篇
  2024年   2篇
  2023年   19篇
  2022年   41篇
  2021年   99篇
  2020年   51篇
  2019年   40篇
  2018年   52篇
  2017年   38篇
  2016年   40篇
  2015年   38篇
  2014年   57篇
  2013年   48篇
  2012年   106篇
  2011年   106篇
  2010年   51篇
  2009年   47篇
  2008年   63篇
  2007年   54篇
  2006年   51篇
  2005年   49篇
  2004年   34篇
  2003年   53篇
  2002年   41篇
  2001年   6篇
  2000年   2篇
  1999年   5篇
  1998年   7篇
  1997年   6篇
  1996年   8篇
  1995年   4篇
  1994年   8篇
  1993年   5篇
  1992年   5篇
  1991年   4篇
  1990年   4篇
  1989年   2篇
  1988年   1篇
  1986年   3篇
  1982年   2篇
  1981年   1篇
  1978年   1篇
  1977年   1篇
  1976年   2篇
  1975年   1篇
  1969年   1篇
排序方式: 共有1259条查询结果,搜索用时 31 毫秒
51.
To elucidate the correlation between regulatory T cells (Tregs) and acute graft-versus-host disease (aGVHD) or cytomegalovirus infection following allogeneic bone marrow transplantation (allo-BMT), we evaluated either CD4?CD25(high) or FOXP3? Treg-enriched cells in peripheral blood (PB) from 20 patients who received allo-BMT, and in biopsies of skin with aGVHD. Proportions of CD4?CD25(high)FOXP3? cells in total lymphocytes, but not other types of T cells, were lower in patients who eventually developed grades II-IV aGVHD (n = 13) than in others (n = 7, P < 0.001). Proportions of CD62L? cells in CD4?CD25(high) cells at day +30 were lower (P < 0.01) in patients who eventually showed cytomegalovirus viremia (n = 6) than in others (n = 14). Incidence of aGVHD (P < 0.05) or cytomegalovirus viremia (P < 0.05) was higher in patients without these complications, but with lower proportions of PB CD4?CD25(high)FOXP3? cells at day +30 (n = 8) than in others (n = 8). However, in skin with aGVHD (n = 5), there was marked or slightly increased infiltration of CD8? cells (P < 0.001) or CD3?FOXP3? cells (P < 0.05), respectively, when compared with control (n = 5), resulting in threefold higher ratio of CD8?/CD3?FOXP3? cells in aGVHD relative to controls (P < 0.05). Thus, impaired reconstitution of Tregs may be associated with aGVHD and CMV infection. Moreover, imbalance of Tregs and CD8? cells may play a role in aGVHD tissue.  相似文献   
52.
We retrospectively investigated the ability of adalimumab (ADA) to reduce disease activity, improve physical function, and retard the progression of structural damage in 167 patients with rheumatoid arthritis. Clinical and functional outcomes were compared between patients with or without prior biologic treatment and those with or without concomitant methotrexate (MTX) treatment. At week 52, 38.3% achieved clinical remission: 42.4 and 28.6% of patients achieved remission in those without and with previous biologics, respectively, while 42.7 and 12.5% of patients achieved remission in those with and without concomitant MTX, respectively. ADA treatment significantly reduced the rate of radiographic progression from 27.1 ± 46.0 (median 13.6; 25th-75th percentiles 8.3 to 28.9) at baseline to 0.8 ± 5.0 (median 0.0; 25th-75th percentiles -0.9 to 2.0) at week 52 (P < 0.0001). Radiographic progression was absent in 59.8% of patients. Sixty adverse events (34.21/100 patient-years) were reported, 16 of which were serious (9.12/100 patient-years). ADA therapy is highly effective for reducing disease activity, improving physical function, and limiting radiographic progression. It is generally safe and well tolerated by Japanese RA patients in routine clinical practice.  相似文献   
53.
Peritoneal fibrosis (PF) causes ultrafiltration failure (UFF) and is a complicating factor in long-term peritoneal dialysis. Lymphatic reabsorption also may contribute to UFF, but little is known about lymphangiogenesis in patients with UFF and peritonitis. We studied the role of the lymphangiogenesis mediator vascular endothelial growth factor-C (VEGF-C) in human dialysate effluents, peritoneal tissues, and peritoneal mesothelial cells (HPMCs). Dialysate VEGF-C concentration correlated positively with the dialysate-to-plasma ratio of creatinine (D/P Cr) and the dialysate TGF-β1 concentration. Peritoneal tissue from patients with UFF expressed higher levels of VEGF-C, lymphatic endothelial hyaluronan receptor-1 (LYVE-1), and podoplanin mRNA and contained more lymphatic vessels than tissue from patients without UFF. Furthermore, mesothelial cell and macrophage expression of VEGF-C increased in the peritoneal membranes of patients with UFF and peritonitis. In cultured mesothelial cells, TGF-β1 upregulated the expression of VEGF-C mRNA and protein, and this upregulation was suppressed by a TGF-β type I receptor (TGFβR-I) inhibitor. TGF-β1–induced upregulation of VEGF-C mRNA expression in cultured HPMCs correlated with the D/P Cr of the patient from whom the HPMCs were derived (P<0.001). Moreover, treatment with a TGFβR-I inhibitor suppressed the enhanced lymphangiogenesis and VEGF-C expression associated with fibrosis in a rat model of PF. These results suggest that lymphangiogenesis associates with fibrosis through the TGF-β–VEGF-C pathway.The decrease in ultrafiltration capacity that is associated with the high peritoneal solute transport that is observed after prolonged peritoneal dialysis (PD) treatment is a major reason for its discontinuation.14 Several studies have shown that a higher peritoneal solute transport rate is associated with reduced survival of PD patients.1,2,5 The characteristic features of chronic peritoneal damage in PD treatment are associated with submesothelial fibrosis and neoangiogenesis.6,7 Analyses of the surface peritoneum showed no significant changes in vessel density with duration of PD.6,8 In addition, the vessel density in patients with ultrafiltration failure (UFF) was significantly higher than the vessel density in normal individuals or non-PD patients, but it was not higher than the vessel density in patients undergoing PD.6 These findings suggest that factors other than increased vascular density may be involved in disease states associated with increased transport of peritoneal membranes. In addition, the relationship between peritoneal fibrosis and UFF remains obscure.Blood capillaries have a continuous basal lamina with tight interendothelial junctions and are supported by pericytes and smooth muscle cells. In contrast, lymphatic capillaries are thin-walled with a wide lumen and do not contain pericytes or basement membrane. The structures of lymphatic vessels are suitable for the removal of tissue fluid, cells, and macromolecules from the interstitium.911 If lymphangiogenesis develops in the peritoneal membrane, absorption of the PD fluid could be increased and lead to UFF. An increase in the number of lymphatic vessels has recently been reported in several disease conditions, including tumor metastasis,1215 chronic respiratory inflammatory diseases,1618 wound healing,19 and renal transplant rejection.20,21 We recently reported that lymphangiogenesis had developed in tubulointerstitial fibrosis of human renal biopsy specimens,22 and we also reported the mechanisms of lymphangiogenesis in rat unilateral ureteral obstruction models.23The lymphatic absorption rate, which is measured by the rate at which intraperitoneally administered radioactive serum albumin or macromolecule dextran 70 disappears, is significantly higher in patients with UFF, and lymphatic reabsorption is considered to be one of the causes of UFF.2427 However, the results from these clinical approaches have been controversial.28,29 In addition, little is known about the pathology and the process of lymphangiogenesis in patients with UFF and peritonitis.In this study, we investigated lymphangiogenesis and the expression of vascular endothelial growth factor-C (VEGF-C), which is a potentially important mediator of lymphangiogenesis, in human peritoneal tissues, PD effluent, and peritoneal mesothelial cells. We also explored VEGF-C induction by TGF-β1 in the human mesothelial cell line (Met-5A) and cultured human peritoneal mesothelial cells (HPMCs) from the spent PD effluent of patients with varying rates of peritoneal transport. Finally, we explored the relationship between peritoneal fibrosis and lymphangiogenesis in rats that were administered chlorhexidine gluconate (CG) into the abdominal cavity, which provides a model of chemically induced peritoneal inflammation/fibrosis.3032 This work is the first report to show that lymphangiogenesis is linked to the peritoneal fibrosis that is often associated with a high peritoneal transport rate.  相似文献   
54.

Background

The significance of perineural invasion in extrahepatic cholangiocarcinoma has not been fully elucidated. This study aims to determine the prognostic impact of and optimal treatment strategy for perineural invasion in patients with extrahepatic cholangiocarcinoma.

Methods

Medical records of 133 patients with extrahepatic cholangiocarcinoma who underwent curative resection were reviewed retrospectively. Ninety-eight patients had perineural invasion and 35 patients did not. Univariate and multivariate survival analyses were performed to clarify the prognostic impact of and optimal treatment strategy for perineural invasion.

Results

Only tumor differentiation (P?=?0.024) was independently associated with perineural invasion in the multivariate logistic regression model. Multivariate survival analysis revealed that perineural invasion (P?=?0.002), resection margin status (P?=?0.016), and International Union Against Cancer (UICC) pT factor (P?=?0.015) were independent prognostic factors of overall survival. Overall 5-year survival rates for patients with and without perineural invasion were 28 and 74 %, respectively. Among 98 patients with perineural invasion, the use of adjuvant chemotherapy (P?=?0.003), lymph node status (P?=?0.015), resection margin status (P?=?0.008), and UICC pT factor (P?=?0.016) were independently associated with overall survival by multivariate analysis. Overall 5-year survival rates for patients with perineural invasion who did and did not receive adjuvant chemotherapy were 33 and 21 %, respectively (P?=?0.023).

Conclusions

Perineural invasion is a potent prognostic factor in extrahepatic cholangiocarcinoma. Adjuvant chemotherapy may improve the overall survival of patients with perineural invasion.  相似文献   
55.
Glucocorticoids cause secondary osteoporosis and myopathy, characterized by type II muscle fiber atrophy. We examined whether a new vitamin D3 analogue, eldecalcitol, could inhibit glucocorticoid-induced osteopenia or myopathy in rats, and also determined the effects of prednisolone (PSL) and/or eldecalcitol on muscle-related gene expression. Six-month-old female Wistar rats were randomized into four groups: PSL group (10 mg/kg PSL); E group (0.05 µg/kg eldecalcitol); PSL + E group; and control group. PSL, eldecalcitol, and vehicles were administered daily for 2 or 4 weeks. Right calf muscle strength, muscle fatigue, cross-sectional areas (CSAs) of left tibialis anterior muscle fibers, and bone mineral density (BMD) were measured following administration. Pax7, MyoD, and myogenin mRNA levels in gastrocnemius muscles were also determined. Muscle strength was significantly higher in the PSL + E group than in the PSL group (p < 0.05) after 4 weeks, but not after 2 weeks. No significant difference in muscle fatigue was seen between groups at 2 or 4 weeks. CSAs of type II muscle fibers were significantly larger in the E group and the PSL + E group than in the PSL group at 4 weeks (p = 0.0093, p = 0.0443, respectively). Eldecalcitol treatment for 4 weeks maintained the same BMD as the PSL + E group. After 2 weeks, but not 4 weeks, eldecalcitol treatment significantly increased Pax7 and myogenin mRNA expression in gastrocnemius muscle, and PSL also stimulated myogenin expression. Eldecalcitol appears to increase muscle volume and to protect against femur BMD loss in PSL-administered rats, and it may also stimulate myoblast differentiation into early myotubes.  相似文献   
56.

Purpose

The present study aimed to assess the safety and feasibility of laparoscopic extended pelvic surgery for primary or recurrent rectal cancer.

Methods

The data on 77 patients, who underwent extended pelvic surgery between February 2008 and June 2014, were retrospectively analyzed. The patients were divided, based on their treatment history, into an open surgery (OS) group (n = 41) and a laparoscopic surgery (LS) group (n = 36).

Results

The operative time in the LS group was significantly longer than that in the OS group (766 vs. 561 min; p < 0.001). In contrast, the LS group was associated with a significantly lower volume of intraoperative blood loss (195 vs. 923 ml; p < 0.001), fluid balance (5.38 vs. 8.23 ml/kg/h; p < 0.001) and rate of complications (40.0 vs. 68.3 %; p = 0.035), and a significantly shorter postoperative hospital stay. The postoperative levels of colloid osmotic pressure and albumin were significantly higher in the LS group.

Conclusion

The operative time of the LS group was longer than that of the OS group; however, the LS group experienced less blood loss and fewer complications. Moreover, LS was associated with a reduction in intraoperative infusions and a reduced fluid balance, which maintained homeostasis.
  相似文献   
57.
58.
59.
Precision or personalized medicine is currently gaining a lot of attention. Clinical evidence for its effectiveness has been established based on randomized clinical trials accounting for classical risk factors, such as hypertension, diabetes, and serum lipids. However, besides such classical risk factors, the genetic background should be considered, at least for heritable traits, including atherosclerotic cardiovascular disease (ASCVD). Such classical risk factors are almost always incidents that have already occurred in which it may be too late to start treatment, instead of indicators of presymptomatic state. Human genome information is associated with most traits, including ASCVD. Two methods of implementing precision medicine for ASCVD using human genome information are currently being investigated: the use of rare genetic variations that have large effect sizes and polygenic risk scores that are composed of multiple common genetic variations. This review article emphasizes the importance of clinical as well as genetic diagnoses when implementing precision medicine. Precision medicine should be considered based on comprehensive genetic analyses, encompassing rare to common genetic variations.  相似文献   
60.
We herein describe a 60-year-old Japanese man with a giant retroperitoneal liposarcoma undergoing leiomyosarcomatous differentiation. He was admitted to our hospital because of a 5-month history of dysphagia and abdominal distention. Abdominal computed tomography showed a giant tumor that occupied the entire retroperitoneal space. The majority of the mass was lipomatous and low density; both a heterogenous and solid mass were also present. A giant retroperitoneal liposarcoma was diagnosed, and tumor resection was performed. At surgery, the tumor was mostly isolated from the retroperitoneum and other organs. Histopathologically, the tumor comprised well-differentiated and dedifferentiated liposarcoma with heterologous differentiation of the leiomyosarcomatous components, which is a rare phenomenon in liposarcoma. The patient was alive 3 years after the first treatment, although he has had 3 local recurrences (approximately one recurrence yearly) and has been treated by repeated resection and radiotherapy.Key words: Retroperitoneum, Liposarcoma, Leiomyosarcomatous differentiationDedifferentiated liposarcoma (DL) is one of the most frequent sarcomas of the retroperitoneum. It is defined by the association of an atypical lipomatous tumor, namely, areas of well-differentiated liposarcoma (WDL), with a dedifferentiated component. WDL is composed of mature adipocytes and atypical stromal cells with an enlarged, hyperchromatic nucleus. Usually, the dedifferentiated part of the liposarcoma is composed of either a spindle/pleomorphic high-grade sarcoma or a mixoid/spindle cell low-grade sarcoma. The WDL component may be easily overlooked, and DL may thus be mistaken for another high-grade sarcoma. It has been reported in one study that approximately 5% of the dedifferentiated component showed heterologous differentiation, such as leiomyosarcoma, rhabdomyosarcoma, osteosarcoma, and angiosarcoma.1 A less common phenomenon is the occurrence of WDL with leiomyosarcomatous (LMS) differentiation.2 Limited to the retroperitoneum, only 8 cases of liposarcoma with LMS components have been reported.37 We herein report a case of retroperitoneal liposarcoma comprising WDL and DL, with LMS components, treated by surgical resection.  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