全文获取类型
收费全文 | 19726篇 |
免费 | 999篇 |
国内免费 | 126篇 |
专业分类
耳鼻咽喉 | 123篇 |
儿科学 | 443篇 |
妇产科学 | 259篇 |
基础医学 | 2328篇 |
口腔科学 | 329篇 |
临床医学 | 1221篇 |
内科学 | 5293篇 |
皮肤病学 | 310篇 |
神经病学 | 1182篇 |
特种医学 | 719篇 |
外科学 | 3994篇 |
综合类 | 79篇 |
预防医学 | 436篇 |
眼科学 | 173篇 |
药学 | 1509篇 |
中国医学 | 33篇 |
肿瘤学 | 2420篇 |
出版年
2023年 | 144篇 |
2022年 | 257篇 |
2021年 | 474篇 |
2020年 | 285篇 |
2019年 | 384篇 |
2018年 | 448篇 |
2017年 | 337篇 |
2016年 | 406篇 |
2015年 | 446篇 |
2014年 | 571篇 |
2013年 | 664篇 |
2012年 | 1176篇 |
2011年 | 1251篇 |
2010年 | 739篇 |
2009年 | 603篇 |
2008年 | 1092篇 |
2007年 | 1109篇 |
2006年 | 1103篇 |
2005年 | 1100篇 |
2004年 | 1081篇 |
2003年 | 1039篇 |
2002年 | 1109篇 |
2001年 | 410篇 |
2000年 | 389篇 |
1999年 | 429篇 |
1998年 | 285篇 |
1997年 | 224篇 |
1996年 | 206篇 |
1995年 | 171篇 |
1994年 | 154篇 |
1993年 | 119篇 |
1992年 | 286篇 |
1991年 | 234篇 |
1990年 | 253篇 |
1989年 | 202篇 |
1988年 | 188篇 |
1987年 | 201篇 |
1986年 | 163篇 |
1985年 | 179篇 |
1984年 | 116篇 |
1983年 | 78篇 |
1982年 | 65篇 |
1981年 | 38篇 |
1980年 | 46篇 |
1979年 | 101篇 |
1978年 | 54篇 |
1977年 | 53篇 |
1974年 | 45篇 |
1972年 | 38篇 |
1969年 | 44篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
Shinichi Suzuki Kiyotaka Imoto Keiji Uchida Naoki Hashiyama Yoshinori Takanashi 《Annals of thoracic and cardiovascular surgery》2005,11(6):424-428
This report describes the use of transluminal endovascular grafting for the treatment of a presumed aortoduodenal fistula. The patient was a 71-year-old man who had undergone resection and graft replacement for an abdominal aortic aneurysm. Three years after operation, melena was caused by perforation of the duodenal wall by a pseudoaneurysm at the proximal graft anastomosis. The pseudoaneurysm was treated by transluminal endovascular grafting. The pseudoaneurysm was subsequently thrombosed and absorbed. The ulcer-like lesions at the site of the duodenal wall perforated by the pseudoaneurysm also resolved. Endovascular stent-grafts may have a role to play in management of aortoduodenal fistula. 相似文献
52.
Evidence for the involvement of a plasma kallikrein-kinin system in the immediate hypotension produced by endotoxin in anaesthetized rats. 总被引:4,自引:4,他引:0 下载免费PDF全文
M. Katori M. Majima R. Odoi-Adome N. Sunahara Y. Uchida 《British journal of pharmacology》1989,98(4):1383-1391
1. In vitro incubation of normal rat plasma with endotoxin from E. coli (3-10 mg ml-1) in the incubation mixture) caused a dose-dependent increase in levels of free kinin and plasma kallikrein in the presence of o-phenanthroline, together with a mirror-image, dose-dependent decrease in the residual levels of the precursors, plasma prekallikrein and high-molecular-weight kininogen. Low-molecular-weight kininogen levels were not modified. 2. Intravenous injection of endotoxin (3-30 mg kg-1) into the femoral vein of anaesthetized rats resulted in dose-dependent hypotension. In blood collected up to 15 min after injection, the levels of prekallikrein and high-molecular-weight kininogen in plasma were decreased while levels of the active forms, plasma kallikrein and free kinin, showed a transient increase in the blood 1 min after administration of endotoxin. 3. A degradation product of bradykinin, des-Phe8-Arg9-bradykinin, as measured by a newly developed enzyme immunoassay, was detectable up to 5 min after administration of endotoxin. 4. Intravenous infusion of soybean trypsin inhibitor inhibited both the formation of bradykinin and des-Phe8-Arg9-bradykinin and the initial hypotension. 5. It can be concluded from our results that plasma prekallikrein is activated in the blood immediately after administration of endotoxin to rats and that bradykinin is a major cause of the immediate hypotension. 相似文献
53.
Yamamoto Kazuhiko; Nakajima Akira; Eimoto Hiroyuki; Tsutsumi Masahiro; Maruyama Hiroshi; Denda Ayumi; Nii Hiroaki; Mori Yukio; Konishi Yoichi 《Carcinogenesis》1989,10(9):1607-1611
The carcinogenic activity of endogenously synthesized N-nitrosobis(2-hydroxypropyl)amine(BHP) was investigated in male Wistar rats administered bis(2-hydroxypropyl)amine(BHPA) mixed in powder diet at a concentration of 1%, and sodiumnitrite (SN) dissolved in distilled water at concentrationsof 0.15 and 0.3%, for 94 weeks. Urinary excretion of BHP wasdetected in rats given 1% BHPA and 0.3% SN but not in the groupsreceiving either of these precursors alone. Nasal cavity, lung,esophagus, liver and urinary bladder tumors were found in animalstreated with combinations of 1% BHPA and 0.15 or 0.3% SN, suggestingthat the target organs of the endogenously synthesized BHP aresimilar to those affected when the carcinogen is administeredexogenously. The incidences of nasal cavity and lung tumorsreached 74 and 58% in rats given 1% BHPA and 0.3% SN, respectively.Tumors at sites other than target organs were only found atlevels similar to those previously reported for spontaneoustumors in male Wistars. The present results clearly indicatedthe tumor inducibility of a nhrosatable amine, BHA, throughan endogenous nitrosation by feeding to rats in conjunctionwith nitrite, and provide further suggestive evidence that endogenousnitrosations of environmental nitrosatable amines can be a potentialrisk factor in human cancer development. 相似文献
54.
Tsuyoshi Takahashi Keiji Iwasaki† Paul S. Malchesky† Hiroaki Harasaki† Michiaki Matsushita† Yukihiko Nosé† Henry Rolin III‡ Phillip M. Hall‡ 《Artificial organs》1993,17(3):153-163
Abstract: Pyridoxalated-hemoglobin-polyoxyethylene conjugate (PHP), which is made from out-dated human red blood cells by two major chemical modifications, namely pyridoxalation and conjugation with polyoxyethylene (POE), is currently under development as a physiological oxygen carrier. This study assessed the effects of PHP-88 solution, which contains 8% (wt/vol) each of hemoglobin (Hb) and maltose, on renal function when it was infused 3 times every other day into the intact circulation of 8 dogs (5 dogs for the PHP group and 3 for the control group; 20 ml/kg for the first infusion, and 10 ml/kg each for the second and third infusions, at the rate of 2.5 ml/h/kg). Serial determinations of glomerular filtration rate (GFR) and renal plasma flow (RPF) were carried out pre- and postinfusion for up to 3 months along with measurements of blood and urine analyses, urine output rate, fractional excretion of sodium (FES), and free water clearance (CH2O). The results showed that plasma colloid osmotic pressure (COP) elevated an average of 3.3 mm Hg (p = 0.0085), and GFR and RPF tended to increase by 13% (NS) and 38% (NS), respectively, immediately after the third infusion with PHP solution. Urine output rate increased during and after the infusion, and FES and CH2O also increased for 24 h after the infusion in both groups. Blood urea nitrogen, serum creatinine, and serum Na+ concentrations were not affected greatly by the infusions, but hematocrit was decreased by 8% in the PHP group, indicating approximately a 42% expansion of plasma volume. These changes were observed to return to their preinfusion levels by 1 week postinfusion. Renal histology of the PHP group obtained at 2 weeks postinfusion revealed vacuole formation in the proximal tubules which was not associated with any pathologic changes indicative of cell death or regeneration. In 4 out of 5 dogs at 3 months postinfusion (necropsy), the vacuoles were not present. Though urinary N-acetyl β-glucosaminidase (NAG) activity had significantly increased after infusion, it returned to the preinfusion level by 1 month postinfusion. No detrimental effect of vacuoles on the assessed renal tubular functions was confirmed in the present study. The result demonstrated that multiple infusions of PHP solutions were well tolerated in normal dogs, and the observed effects were conceived predominantly attributable to the physiological response of the kidneys to an oncotic load into the circulation, which produced plasma volume expansion. 相似文献
55.
Effect of epidural analgesia on postoperative insulin resistance as evaluated by insulin clamp technique 总被引:18,自引:0,他引:18
The influence of epidural neural blockade on postoperative insulin resistance was studied using the euglycaemic insulin clamp technique. Eighteen patients undergoing elective upper abdominal surgery of moderate severity were allocated to two groups: group G patients underwent operation under general anaesthesia, and postoperative pain was relieved by systemic administration of analgesia; and group E patients received epidural analgesia during surgery and epidural morphine postoperatively. In each patient the euglycaemic insulin clamp test was performed twice: several days before surgery and on postoperative day 1. Peroperative catecholamine and cortisol responses were also measured to investigate possible endocrine mechanisms of the insulin resistance. Glucose disposal (M) decreased in both groups on postoperative day 1 at plasma insulin concentrations ranging from 1.2 to 10.0 milliunits ml-1, resulting in the downward shift of dose-response curves. However, this downward shift was significantly smaller in group E than in group G patients. Urinary adrenaline excretion increased markedly on the day of operation in group G, but was significantly inhibited in group E. Urinary noradrenaline excretion increased mainly on postoperative day 1 in group G, but was significantly inhibited in group E. Plasma cortisol response was lower in group E than in group G during and shortly after operation, and was significantly inhibited in group E on postoperative day 1. These results indicate that insulin resistance after elective abdominal surgery is due to a postreceptor deficit in glucose utilization, as indicated by the downward shift of the dose-response curves. This disturbance in glucose metabolism was reduced by epidural analgesia, the results being associated with inhibited catecholamine and cortisol responses. 相似文献
56.
57.
Toshiyuki Matsui Sumio Tsuda Hiroaki Matake Keisuke Ikeda Tsuneyoshi Yao 《Digestive endoscopy》2004,16(Z1):S27-S30
Background: Gastrointestinal strictures are the most often and serious complication in Crohn's disease. Because of the frequent postoperative recurrence in Crohn's disease, endoscopic therapy of gastrointestinal stricture is one of the best therapeutic options. Method: The present study sets out the results from a prospective study of endoscopic dilation therapy on 48 Crohn's disease patients with severe gastrointestinal stenoses. All patients who could not undergo endoscopic balloon dilation therapy (EBD) were operated on. Results: Long‐term success was attained in 32 of the 48 patients; cumulative avoidance of surgery after EBD was 86% at one year and 71% at three. Second, the most hazardous factor was recurrent inflammation causing restenosis. Patients who had strictures with oral luminal dilatation and patients with frequent recurrence had a tendency to be operated on. As a complication, perforation occurred in two cases (3.3%). Conclusions: EBD therapy for Crohn's stricture in the gastrointestinal tract is recommended before surgical intervention. 相似文献
58.
Y. Uchida M. Kasahara H. Egawa Y. Takada K. Ogawa Y. Ogura K. Uryuhara D. Morioka S. Sakamoto Y. Inomata Y. Kamiyama K. Tanaka 《American journal of transplantation》2006,6(10):2443-2448
Our objective was to analyze problems in the perioperative management and long-term outcome of living donor liver transplantation (LDLT) for biliary atresia (BA). Many reports have described the effectiveness of liver transplantation (LT) for BA, particularly in pediatric cases, but little information is available regarding LT in adults (> or =16 years old). Between June 1990 and December 2004, 464 patients with BA underwent LDLT at Kyoto University Hospital, of whom 47 (10.1%) were older than 16 years. In this study, we compared the outcomes between adult (> or =16 years old) and pediatric (<16 years old) patients. The incidence of post-transplant intestinal perforation, intra-abdominal bleeding necessitating repeat laparotomy and biliary leakage was significantly higher (p < 0.0001, <0.001 and <0.001, respectively) in adults. Overall cumulative 1-, 5- and 10-year survival rates in pediatric patients were significantly higher (p < 0.005) than in adults. Two independent prognostic determinants of survival were identified: a MELD score over 20 and post-transplant complications requiring repeat laparotomy. Outcome of LDLT in adult BA patients was poorer than in pediatric patients. It seems likely that LT will be the radical treatment of choice for BA and that LDLT should be considered proactively at the earliest possible stage. 相似文献
59.
60.
Hiroaki Hoshi Seishi Jinnouchi Kuniko Harada Katsushi Watanabe 《European journal of nuclear medicine and molecular imaging》1988,14(4):177-179
Gallium scintigraphy was evaluated in 25 patients with adult T-cell leukemia lymphoma (ATLL). Anterior and posterior images were obtained at 72 h after administration of 3 mCi 67Ga-citrate using a gamma camera (Maxi-Camera 400T, General Electric Co.) with a medium energy standard parallel hole collimator. Abnormally high accumulations were observed in 17 out of 25 cases (superficial lymph node, 8; hilar and mediastinal lymph node, 7; paraaortic lymph node, 2; lung, 9; liver, 1; bone, 1). There were 10 malignant lesions detected by 67Ga scintigraphy in 9 out of 17 cases (superficial lymph node, 1; hilar and mediastinal lymph node, 6; paraaortic lymph node, 1; liver, 1; bone, 1). White blood cell count and serum LDH levels were raised in patients with abnormally high accumulations of 67Ga. In conclusion, 67Ga scintigraphy seemed to be a useful examination to detect malignant lesions in patients with ATLL. 相似文献