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   1609篇
  免费   105篇
  国内免费   13篇
耳鼻咽喉   45篇
儿科学   30篇
妇产科学   17篇
基础医学   210篇
口腔科学   29篇
临床医学   93篇
内科学   435篇
皮肤病学   9篇
神经病学   127篇
特种医学   57篇
外科学   300篇
综合类   13篇
预防医学   28篇
眼科学   33篇
药学   152篇
中国医学   8篇
肿瘤学   141篇
  2023年   10篇
  2022年   14篇
  2021年   41篇
  2020年   28篇
  2019年   27篇
  2018年   39篇
  2017年   39篇
  2016年   33篇
  2015年   42篇
  2014年   77篇
  2013年   67篇
  2012年   127篇
  2011年   90篇
  2010年   54篇
  2009年   60篇
  2008年   69篇
  2007年   110篇
  2006年   70篇
  2005年   77篇
  2004年   77篇
  2003年   79篇
  2002年   77篇
  2001年   48篇
  2000年   38篇
  1999年   36篇
  1998年   23篇
  1997年   18篇
  1996年   16篇
  1995年   9篇
  1994年   8篇
  1993年   6篇
  1992年   18篇
  1991年   13篇
  1990年   16篇
  1989年   23篇
  1988年   20篇
  1987年   14篇
  1986年   15篇
  1985年   15篇
  1984年   9篇
  1983年   11篇
  1979年   7篇
  1978年   5篇
  1977年   6篇
  1976年   5篇
  1972年   4篇
  1971年   3篇
  1969年   5篇
  1968年   5篇
  1967年   6篇
排序方式: 共有1727条查询结果,搜索用时 203 毫秒
71.
Guinea pig gonadotropin-releasing hormone (gpGnRH) is predicted to have a unique structure among all known forms of GnRH molecule [Endocrinology 138 (1997) 4123] and it is of great interest to determine whether the unique structure of gpGnRH is manifested in the characteristics of the guinea pig GnRH receptor. In the present study, we isolated a full-length cDNA for a GnRH receptor from the pituitary gland of the guinea pig. The putative guinea pig GnRH receptor protein has an amino acid identity of 79-87% with mammalian type I GnRH receptors. The amino acid residues which have been demonstrated to be important for ligand binding and signal transduction were conserved in the guinea pig GnRH receptor. However, there are several specific amino acid substitutions among mammalian type I GnRH receptors. Moreover, though the guinea pig has generally been classified as a rodent, the putative GnRH receptor protein did not have some rodent-specific characteristics. Total IP assays demonstrated that the cloned guinea pig GnRH receptor is a functional GnRH receptor and that it shows different preference of ligand sensitivities from the rat GnRH receptor.  相似文献   
72.
Conclusion: Longitudinal assessments of carnitine and fatigue in patients with head and neck squamous cell carcinoma suggest that cisplatin damages the carnitine system in patients undergoing chemoradiotherapy and that carnitine deficiency increases fatigue. Objectives: The purpose of this study was to monitor carnitine levels and fatigue in patients who received cisplatin-based CRT and, for comparison, in patients treated by surgery alone. Methods: To investigate the level of carnitine, mice were administered cisplatin. Next, a prospective analysis was performed to compare plasma carnitine levels before and after cisplatin-based chemoradiotherapy and to assess the relationship between carnitine levels and fatigue. Results: The plasma levels of total carnitine (TC), free carnitine (FC), and fatty acylcarnitine (AC) were significantly lower in mice receiving cisplatin compared with control mice. Mean total carnitine and free carnitine levels were significantly lower 2 weeks after chemoradiotherapy (total carnitine: Mean = 45.6, SD = 16.5, p = 0.01; free carnitine: Mean = 37.8, SD = 12.7, p = 0.02) than before chemoradiotherapy (total carnitine: Mean = 57.7, SD = 12.2; free carnitine: Mean = 48.1, SD = 11.6). There was a significant inverse correlation between carnitine levels and fatigue after chemoradiotherapy.  相似文献   
73.
The evaluation of subvisible particles, including protein aggregates, in therapeutic protein products has been of great interest for both pharmaceutical manufacturers and regulatory agencies. To date, the flow imaging (FI) method has emerged as a powerful tool instead of light obscuration (LO) due to the fact that (1) protein aggregates contain highly transparent particles and thereby escape detection by LO and (2) FI provides detailed morphological characteristics of subvisible particles. However, the FI method has not yet been standardized nor listed in any compendium. In an attempt to assess the applicability of the standardization of the FI method, we conducted a collaborative study using FI and LO instruments in a Japanese biopharmaceutical consortium. Three types of subvisible particle preparations were shared across 12 laboratories and analyzed for their sizes and counts. The results were compared between the methods (FI and LO), inter-laboratories, and inter-instruments (Micro Flow Imaging and FlowCam). We clarified the marked difference between the detectability of FI and LO when counting highly transparent protein aggregates in the preparations. Although FlowCam provided a relatively higher number of particles compared with MFI, consistent results were obtained using the instrument from the same manufacturer in all 3 samples.  相似文献   
74.

Purpose

Although distraction osteogenesis has been widely accepted to treat craniosynostosis, it occasionally results in wound complications. Positing that they are attributable to the tense pericranium under the scalp, we developed a simple technique to relax the pericranial flap.

Methods

In 12- to 15-month-old infants (mean 13 months), we placed a coronal skin incision and dissected the scalp at the subgaleal layer. Then, we peeled the intact pericranium away from the skull along the planned osteotomy to obtain flaps with pedicles on the caudal part. After osteotomy and setting of the distraction device, the pericranial flaps freed from the scalp flap were repositioned to fit the osteotomy line, dura, and distraction device. The galea and skin were approximated layer by layer.

Results

The shape of the skull was successfully corrected, and the bone defect created by expansion was filled by osteogenesis in all patients. During a mean follow-up period of 42.2 months, we encountered no wound complications.

Conclusions

The replaced relaxed pericranium closely adhered to the osteotomy, and the distraction device facilitated vascular growth and bone restoration. Bone resorption was prevented and skin expansion promoted. In patients with iatrogenic dural injury, the pericranium over the injured dura serves as a barrier to prevent cerebrospinal fluid leakage.  相似文献   
75.
76.
To clarify whether probucol and statins suppress oxidative stress in diabetic patients, we studied the effects of probucol and the statin atorvastatin on urinary 8-hydroxy-2'deoxyguanosine (8-OHdG) levels in diabetics with hypercholesterolemia. A randomized, open study was performed on a total of 36 patients with type 2 diabetes and hypercholesterolemia. The patients were randomly assigned to a probucol group (500 mg/day, n = 18) or an atorvastatin group (10 mg/day, n = 18). During three months, total- and LDL-cholesterol decreased significantly in both groups. LDL-cholesterol was significantly lower in the atorvastatin group than probucol group. HDL-C decreased significantly in the probucol group and did not change in the atorvastatin group. 8-OHdG decreased significantly in both groups after 3 months; 12.4 +/- 7.5 to 8.1 +/- 4.2 ng/mg/Cr in the atorvastatin group (p < 0.05) and 12.3 +/- 8.8 to 6.8 +/- 2.6 ng/mg/Cr in the probucol group (p < 0.05), and these changes did not differ significantly between the two groups. But, in patients with high 8-OHdG levels (more than 10 ng/mg/Cr) before administration, urinary 8-OHdG decreased significantly from 19.5 +/- 4.9 to 9.2 +/- 3.4 ng/mg Cr (p < 0.01) in the atorvastatin group, and from 19.7 +/- 8.2 to 6.67 +/- 2.2 ng/mg Cr (p < 0.01) in the probucol group. Urinary 8-OHdG was significantly lower in the probucol group than in the atorvastatin group after the second and third months of administration (p < 0.05). These results suggest that while probucol and atorvastatin both reduce systemic oxidative stress, probucol might be the more useful in patients with strong oxidative stress.  相似文献   
77.
In the present study, we analyzed the kinetics of serum soluble interleukin-2 receptor (sIL-2R) using data from 77 patients undergoing HLA-haploidentical transplantation using reduced-intensity conditioning (RIC), who were at an advanced stage or at high risk for relapse, to clarify the usefulness of sIL-2R as a biomarker of acute graft-versus-host disease (GVHD). Anti-T-lymphocyte globulin and methylprednisolone were used as GVHD prophylaxis. While the median sIL-2R in 38 patients not developing GVHD was suppressed at levels <740 U/ml, sIL-2R in 25 patients developing severe GVHD peaked on day 11 (1,663 U/ml), and thereafter decreased to <1,000 U/ml after day 30. The occurrence of GVHD was not limited to times of high sIL-2R level, but occurred at any time point on the sIL-2R curve. Most patients developing GVHD, however, experienced a higher sIL-2R level early in their transplant course. The combination of RIC and glucocorticoids sufficiently suppressed sIL-2R levels after HLA-haploidentical transplantation. In a multivariate analysis to identify factors associated with GVHD, day 7 sIL-2R >810 U/ml was the only factor significantly associated with the occurrence of severe GVHD (p = 0.0101).  相似文献   
78.
79.
80.
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