全文获取类型
收费全文 | 19994篇 |
免费 | 1307篇 |
国内免费 | 172篇 |
专业分类
耳鼻咽喉 | 225篇 |
儿科学 | 416篇 |
妇产科学 | 198篇 |
基础医学 | 2519篇 |
口腔科学 | 352篇 |
临床医学 | 1567篇 |
内科学 | 5396篇 |
皮肤病学 | 483篇 |
神经病学 | 1337篇 |
特种医学 | 811篇 |
外科学 | 2854篇 |
综合类 | 247篇 |
一般理论 | 21篇 |
预防医学 | 1281篇 |
眼科学 | 394篇 |
药学 | 1271篇 |
中国医学 | 64篇 |
肿瘤学 | 2037篇 |
出版年
2023年 | 109篇 |
2022年 | 197篇 |
2021年 | 443篇 |
2020年 | 292篇 |
2019年 | 388篇 |
2018年 | 452篇 |
2017年 | 439篇 |
2016年 | 487篇 |
2015年 | 539篇 |
2014年 | 679篇 |
2013年 | 845篇 |
2012年 | 1350篇 |
2011年 | 1327篇 |
2010年 | 816篇 |
2009年 | 663篇 |
2008年 | 1222篇 |
2007年 | 1367篇 |
2006年 | 1231篇 |
2005年 | 1256篇 |
2004年 | 1137篇 |
2003年 | 1167篇 |
2002年 | 1112篇 |
2001年 | 358篇 |
2000年 | 320篇 |
1999年 | 348篇 |
1998年 | 227篇 |
1997年 | 213篇 |
1996年 | 181篇 |
1995年 | 160篇 |
1994年 | 123篇 |
1993年 | 102篇 |
1992年 | 223篇 |
1991年 | 176篇 |
1990年 | 184篇 |
1989年 | 158篇 |
1988年 | 119篇 |
1987年 | 103篇 |
1986年 | 75篇 |
1985年 | 83篇 |
1984年 | 67篇 |
1983年 | 64篇 |
1982年 | 47篇 |
1981年 | 38篇 |
1980年 | 43篇 |
1979年 | 53篇 |
1978年 | 45篇 |
1977年 | 46篇 |
1973年 | 40篇 |
1972年 | 40篇 |
1970年 | 41篇 |
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
91.
Deborah Miller Dina Macdonald Ken Kolnacki Teresa Simek 《Nephrology nursing journal》2004,31(3):287-94; quiz 295-6
An important treatment goal for pediatric nephrology caregivers is the optimization of a child's capacity for normal growth and development. However, the physiologic and metabolic derangements associated with chronic kidney disease (CKD) significantly alter these processes, creating important challenges in the care of affected children. Evidence-based clinical practice guidelines support early recognition and treatment of CKD-related complications to improve growth and development and, ultimately, quality of life for children with this chronic condition. 相似文献
92.
A rare case of primary linitis plastica carcinoma of the colon seen in a 44 year old Japanese man is described herein. The patient had a complete obstruction of the descending colon and was treated with a loop colostomy followed shortly afterward by a left hemicolectomy. At the time of the second operation, the entire thickness of the colonic wall was found to be infiltrated by cancer cells, however, the other intraabdominal organs were free of cancerous involvement. The histopathological diagnosis made at this time was primary linitis plastica carcinoma of the descending colon. Nine months later, the patient developed an intestinal obstruction and relaparotomy revealed diffuse peritoneal dissemination. Two years after the first operation, upper GI films and a gastrofiberscopic examination revealed gastric involvement. The patient died 28 months after his initial operation, and autopsy revealed widespread metastases in the peritoneal surface, paraaortic lymph nodes, small intestine, remaining colon and stomach. 相似文献
93.
Mycosis fungoides (M.F.) is a rare cutaneous malignancy of childhood and adolescence. The disease commonly presents with the classic sequence of erythematous patches and plaques. Hypopigmentation as the presenting symptom is distinctly rare. This is the 9th case report of M.F. presenting with hypopigmentation in a patient under 20 years of age. The disease was only partially controlled with PUVA therapy, necessitating nitrogen mustard treatment. 相似文献
94.
95.
96.
Department of Urology, School of Medicine, Keio University, Tokyo, Japan
Background Conventional therapy for renal cell carcinoma using interferon (IFN) has shown limited antitumor action. The purpose of our study was to investigate synergistic antitumor effects of IFN and 5-fluorouracil (5-FU), and to elucidate the mechanisms of interaction between the 2 agents in mice.
Methods Antitumor effects and biochemical modulation of murine IFN-α/β and 5-FU were determined against the murine renal cell carcinoma cell line, Renca, in vivo. The activity of thymidylate synthetase and thymidine kinase was measured using cytosolic extracts of the tumors.
Results Combination treatment with IFN-α/β and 5-FU produced a significant enhancement of growth inhibition against Renca tumor. Treatment with 5-FU resulted in a 2.7-fold increase in the total amount of thymidylate synthetase and an 11.6-fold increase in the thymidylate synthetase inhibition rate, while the administration of IFN-α/β did not significantly reduce the 5-FU-induced increase in thymidylate synthetase. The administration of IFN-α/β decreased thymidine kinase activity to 65.5% maximally, compared with that in the control mice or the mice treated with 5-FU.
Conclusions The reduction of thymidine kinase caused by treating the mice with IFN-α/β changes the utilization of exogenous thymidine for DNA synthesis, and may represent the mechanism of the additive antitumor effect of the 2 agents, through the suppression of the salvage pathway for deoxythymidine monophosphate induction. 相似文献
Background Conventional therapy for renal cell carcinoma using interferon (IFN) has shown limited antitumor action. The purpose of our study was to investigate synergistic antitumor effects of IFN and 5-fluorouracil (5-FU), and to elucidate the mechanisms of interaction between the 2 agents in mice.
Methods Antitumor effects and biochemical modulation of murine IFN-α/β and 5-FU were determined against the murine renal cell carcinoma cell line, Renca, in vivo. The activity of thymidylate synthetase and thymidine kinase was measured using cytosolic extracts of the tumors.
Results Combination treatment with IFN-α/β and 5-FU produced a significant enhancement of growth inhibition against Renca tumor. Treatment with 5-FU resulted in a 2.7-fold increase in the total amount of thymidylate synthetase and an 11.6-fold increase in the thymidylate synthetase inhibition rate, while the administration of IFN-α/β did not significantly reduce the 5-FU-induced increase in thymidylate synthetase. The administration of IFN-α/β decreased thymidine kinase activity to 65.5% maximally, compared with that in the control mice or the mice treated with 5-FU.
Conclusions The reduction of thymidine kinase caused by treating the mice with IFN-α/β changes the utilization of exogenous thymidine for DNA synthesis, and may represent the mechanism of the additive antitumor effect of the 2 agents, through the suppression of the salvage pathway for deoxythymidine monophosphate induction. 相似文献
97.
Takao Kato Tsunehito Kimura Ryuhei Miyakawa Shinichi Tanaka Akiho Fujii Kazuko Yamamoto Shingo Kameoka Kyoichi Hamano Makio Kawakami Motohiko Aiba 《World journal of surgery》1997,21(1):49-56
p
= 0.0007) and tumor necrosis (TN) (HMC:
p
= 0.0050). Univariate analysis showed that AMC or HMC was a statistically significant predictor of overall survival in all
patients (
p
= 0.0086 and
p
= 0.0307, respectively). Multivariate analysis showed that AMC was an independent predictor of node status when we fitted
a model with node status, BVI, and either AMC or HMC; but HMC was not independent. However, when we fitted a model including
all 11 of the other indicators and AMC or HMC, the node status, HG, and LI were independent predictors, but AMC and HMC were
not. Although AMC was a better method than HMC for evaluating angiogenesis, we cannot confirm angiogenesis as a significant
independent prognostic factor associated with long-term survival in Japanese breast cancer patients. 相似文献
98.
99.
Heather A McKay Harri Siev?nen Moira A Petit Kerry J MacKelvie Ken M Forkheim Ken P Whittall Bruce B Forster Heather Macdonald 《Journal of clinical densitometry》2004,7(2):161-168
Conventional density measures by dual-energy X-ray absorptiometry (DXA) are confounded by increases in bone size and do not assess bone geometry. We assessed precision of magnetic resonance imaging (MRI) and used MRI, DXA, and hip structure analysis (HSA) to assess 7-mo changes in bone structure at the femoral neck in 18 prepubertal girls. At baseline, girls were 10.4 (0.5) yr, 144.0 (8.2) cm, and 35.2 (7.0) kg, on average. Total bone and cortical cross-sectional area (ToA and CoA) were calculated from high-resolution T1-weighted MRI oblique axial images of the femoral neck. We used proximal femur DXA scans (Hologic QDR-4500) and the HSA program to estimate bone cross-sectional area (CSA), and calculate section modulus. MRI precision was determined by scanning 10 volunteers (13-46 yr old) three times with and without repositioning. Precision (CVrms) was 2% for ToA and 7% for CoA. Significant correlations were observed between FN area and MRI-derived ToA (r = 0.57, p = 0.013) and CoA (r = 0.47, p = 0.050). There were significant positive changes over 7 mo by both methods. In conclusion, MRI provides useful information on femoral neck bone area in children. The reproducibility of cortical dimensions at the femoral neck needs improvement through technical modifications and appropriate analysis software. 相似文献
100.
Papillo-Choledochectomy in the Operative Management of Mucosal Neoplasms of the Periampullary Region
Kogoro Kasahara Ken Saito Yasuo Kondo Toshihiko Yasuda Yoshikazu Yasuda Masatoshi Nakada Hideo Nagai Kyotaro Kanazawa 《HPB surgery》1993,6(3):211-217
Two patients with mucosal cancer of the periampullary region were treated with papillocholedochectomy,
which entails removal of the papilla of Vater and the whole length of the common bile duct. The neoplasm is dissected out through the plane between the duodenal circular and longitudinal muscles, deep to the sphincter of Oddi and the fibromuscular layer of the bile duct. Pathological examination showed that cancer was confined to the mucosal layer without stromal invasion, and that the operation achieved radical cure. For mucosal cancer, papillo-choledochectomy is
an alternative to pancreatoduodenectomy, provided that repeated frozen-section studies confirm the
completeness of excision. 相似文献