全文获取类型
收费全文 | 9770篇 |
免费 | 923篇 |
国内免费 | 452篇 |
专业分类
儿科学 | 115篇 |
妇产科学 | 5篇 |
基础医学 | 791篇 |
口腔科学 | 9篇 |
临床医学 | 649篇 |
内科学 | 2996篇 |
皮肤病学 | 19篇 |
神经病学 | 73篇 |
特种医学 | 262篇 |
外国民族医学 | 8篇 |
外科学 | 1526篇 |
综合类 | 1366篇 |
现状与发展 | 3篇 |
预防医学 | 165篇 |
眼科学 | 3篇 |
药学 | 561篇 |
3篇 | |
中国医学 | 165篇 |
肿瘤学 | 2426篇 |
出版年
2024年 | 31篇 |
2023年 | 179篇 |
2022年 | 275篇 |
2021年 | 463篇 |
2020年 | 374篇 |
2019年 | 403篇 |
2018年 | 385篇 |
2017年 | 357篇 |
2016年 | 441篇 |
2015年 | 453篇 |
2014年 | 585篇 |
2013年 | 781篇 |
2012年 | 438篇 |
2011年 | 498篇 |
2010年 | 450篇 |
2009年 | 442篇 |
2008年 | 449篇 |
2007年 | 491篇 |
2006年 | 389篇 |
2005年 | 371篇 |
2004年 | 313篇 |
2003年 | 255篇 |
2002年 | 233篇 |
2001年 | 214篇 |
2000年 | 206篇 |
1999年 | 138篇 |
1998年 | 168篇 |
1997年 | 118篇 |
1996年 | 108篇 |
1995年 | 143篇 |
1994年 | 117篇 |
1993年 | 92篇 |
1992年 | 77篇 |
1991年 | 85篇 |
1990年 | 74篇 |
1989年 | 67篇 |
1988年 | 62篇 |
1987年 | 49篇 |
1986年 | 38篇 |
1985年 | 60篇 |
1984年 | 42篇 |
1983年 | 21篇 |
1982年 | 35篇 |
1981年 | 30篇 |
1980年 | 32篇 |
1979年 | 19篇 |
1978年 | 20篇 |
1976年 | 11篇 |
1975年 | 11篇 |
1973年 | 10篇 |
排序方式: 共有10000条查询结果,搜索用时 78 毫秒
31.
K. Iwatsuki L-M. Ren S. Chiba 《Clinical and experimental pharmacology & physiology》1994,21(9):701-707
1. The effects of the cyclic nucleotide phosphodiesterase (PDE) inhibitors, Ro20,1724, 3-isobutyl-1-methylxanthine (IBMX), trifluoperazine (TFP) and amrinone on pancreatic exocrine secretion were investigated in anaesthetized dogs in comparison with those of secretin and cholecystokinin octapeptide (CCK-8). 2. Ro20,1724 (1–30 nmol/kg), IBMX (3–30 nmol/kg), secretin (0.01–0.1 pmol/kg) or CCK-8 (0.1–1 pmol/kg) injected i.a. elicited a dose-dependent increase in the secretion of pancreatic juice, but TFP and amrinone (up to 1 μmol/ kg) did not. 3. The bicarbonate concentration in pancreatic juice was increased and the protein concentration was decreased by Ro20,1724, IBMX and secretin. Cholecystokinin octapeptide increased the protein concentration but did not alter the bicarbonate concentration. 4. Ro20,1724 and IBMX elicited more than the respective additive secretory response when added together with secretin, although the stimulatory effects of CCK-8 with Ro20,1724 and IBMX were additive. 5. Ro20,1724 and IBMX increased cyclic AMP concentration but did not affect cyclic GMP concentration. 6. These results suggest that Ro20,1724 and IBMX have secretory properties on pancreatic exocrine glands of the dog, which may be mediated through an increase in cyclic AMP subsequent to inhibition of PDE activity. Furthermore, pancreatic PDE enzymes in the dog may be mainly type IV. 相似文献
32.
K. Iwatsuki F. Yamagishi S. Chiba 《Clinical and experimental pharmacology & physiology》1986,13(6):487-494
The effects of a synthesized phosphodiesterase inhibitor, ZSY-27, on the secretion of pancreatic juice were investigated in dog isolated and blood-perfused pancreas, and compared with those of secretin and dopamine. Intravenous administration of ZSY-27 (0.3-1 mg/kg) elicited increases in pancreatic secretion. Intra-arterial (i.a.) administration of ZSY-27 (0.1-1 mg) also elicited increased secretion. The secretory activity of ZSY-27 (1 mg) was approximately equal to that of 0.1 units of secretin and 2.5 micrograms of dopamine. The concentration of bicarbonate in the pancreatic juice induced by ZSY-27 i.a. was increased, but the protein concentration was not increased significantly. These effects are analogous to those of secretin and dopamine. ZSY-27-induced pancreatic secretion was not modified by pretreatment with phentolamine, propranolol, atropine, sulpiride and cimetidine. Secretin-induced secretion was significantly potentiated by infusion of ZSY-27 (25 micrograms/min) but dopamine-induced one was not. These results suggest that ZSY-27 increases pancreatic secretion acting directly on the ductular cells of the dog pancreas, at least in part, through the increase of intracellular cyclic AMP concentration by inhibiting phosphodiesterase activity. 相似文献
33.
本实验对培养中的大鼠胎胰胰岛组织及其移植后的形态功能进行了观察。结果表明,大鼠胎胰经短期培养,不仅内分泌胰岛β细胞的活力保存良好,而且胰外分泌腺泡大大减少以致消失。21只糖尿病大鼠,同种移植经过7天培养的胎胰胰岛,未用免疫抑制剂,术后糖尿病缓解率76.2%。 相似文献
34.
作者参照国外的方法,结合国内的特点,介绍采用化学消化,机械分离和离心提纯的方法制备胰腺腺泡的过程,并对每一过程的意义和注意点进行了讨论。 相似文献
35.
H Koyama T Maruta T Kudo H Mayahara K Yoshida 《Journal of Medical Imaging and Radiation Oncology》2005,49(6):493-496
We present a case in which multiple pancreatic tumours were diagnosed as metastatic clear cell renal carcinomas with chemical shift MRI (CSI) before surgery. Radiologists may be unable to recognize the loss of intensity on CSI macroscopically. We believe that it is useful to make subtraction images and calculate signal intensity on CSI, even if the lesions are multiple metastatic tumours. 相似文献
36.
37.
Louise Nadon Jack Siemiatycki Ron Dewar Daniel Krewski Michel Grin 《American journal of industrial medicine》1995,28(3):303-324
Polycyclic aromatic hydrocarbons (PAHs) demonstrate carcinogenic activity in animal models. Although some epidemiologic studies have implicated PAHs as risk factors for human cancer, the evidence reported to date has not been consistent. The purpose of this report is to describe the associations between occupational exposure to PAHs in the workplace and each of 14 types of cancer. A population-based, case-control study was carried out in Montreal to investigate associations between a large variety of environmental and occupational exposures on the one hand, and several types of cancer on the other. A detailed job history was obtained from each subject along with information on a number of potential confounders. Each job history was reviewed by a team of experts, who used this information to construct a corresponding history of occupational exposures. Among the PAH exposures considered were benzo(a)pyrene (B(a)P) and five categories of PAHs defined on the basis of the source material, namely, wood, petroleum, coal, other sources, and any source. Altogether, 3,730 cancer patients and 533 population controls were interviewed and their job exposure histories coded. For each of 14 types of cancer analyzed, three control groups were available: other cancer patients, population controls, and the pooled set of cancer and population controls. The associations between 14 cancer types and 6 PAH exposures were analyzed using logistic regression methods. For most types of cancer evaluated, there was no evidence of excess risk due to PAHs at the levels encountered in the occupations in which PAH exposure has been prevalent in the Montreal area. For a few cancer sites–the esophagus, the pancreas, and the prostate gland–there were suggestions of excess risk; these observations are noteworthy hypotheses for further investigation. For lung cancer, there appeared to be an increased risk due to PAHs among nonsmokers and light smokers, but not among heavy smokers. 相似文献
38.
Therapeutic Evaluation on Advanced Pancreatic Cancer Treated by Integrative Chinese and Western Medicine──Clinical Analysis of 56 Cases 总被引:8,自引:0,他引:8
Objective: In comparison with chemotherapy, to evaluate therapeutic effects on advanced pancreatic cancer treated by integrative Chinese and western medicine (ICWM) therapies. Methods: Based on the retrospective study of 56 patients with advanced pancreatic cancer, life table was applied to the analysis of patients' survival rate and Xz test to the comparison of therapeutic response between ICWM and chemotherapy groups. Results: The results showed that 1-year survival rate in the ICWM group was 55. 37%±3.24%; 2-year survival rate 34. 61%±16. 31%; 3-year survival rate 25. 96%±24. 64%; 5-year survival rate 25. 96%±24.64%; and median survival period 16. 3 months. However 1-year survival rate in the chemotherapy group was 21. 95%±27. 54% ; 2-year survival rate 7. 31%±27. 54% ; 3-year survival rate 0 % ; and median survival period 7. 5 months. The therapeutic effects between two groups were significantly different (P=0. 004). Further analysis suggested that the reduction of cancer mass in the ICWM grou 相似文献
39.
Eigo Otsuji Toshiharu Yamaguchi Nozomi Yamaguchi Kunihiko Koyama Jiro Imanishi Nobuki Yamaoka Toshio Takahashi 《Surgery today》1992,22(4):351-356
In a previous study, we used a murine monoclonal antibody, A7, against human colon carcinoma as a drug-carrier to treat colorectal cancer.1 In the present study, we found that MAb A7 also reacted immunohistochemically with 73% of human pancreatic carcinoma cell lines, with the A7 antigen mainly being detected on the cell surface. However, the A7 antigen was found in only 9% of the spent media of these human pancreatic carcinoma cell lines by ELISA. On the other hand, the positive incidence of CA19-9, POA, ferritin, CEA, DU-PAN-2 and SLX in those spent media was 100%, 64%, 64%, 55%, 55% and 36%, respectively. These results suggest that the A7 antigen may only rarely be shed into the sera of pancreatic cancer patients, in which case MAb A7 could be a suitable drug-carrier in targeting chemotherapy for pancreatic cancer patients. 相似文献
40.
D F Du Toit J J Heydenrych B Smit G Louw T Zuurmond D Els A Weideman S Wolfe-Coote L Du Toit R Gonin 《Journal of surgical oncology》1987,36(2):148-153
In this study the endocrine function following intraperitoneal hetero- and orthotopic pancreatico-duodenal-splenic allotransplantation (PDS) in hemipancreatectomized, non-immune-suppressed chacma baboons was assessed. Significantly reduced K-values and insulin release together with glucose intolerance during IVGTT were observed in hemipancreatectomized recipients (HPS) without grafts. Orthotopic and heterotopic PDS transplantation improved the glucose intolerance of HPS recipients; orthotopically sited grafts rendering the best curves. Normal glucose tolerance was not achieved. Both orthotopic and heterotopic PDS transplantation rendered suboptimal insulin release during IVGTT; heterotopically draining grafts released significantly more insulin than orthotopic grafts. Hyperglucagonaemia during IVGTT was a constant feature in both groups, heterotopic grafts releasing the most glucagon during stimulation. C-peptide release was significantly lower in orthotopic grafts compared to normal animals or heterotopically drained insulin. It is concluded that glucose tolerance was not directly related to insulin or glucagon release in this study as orthotopic grafts rendered near-normal IVGTT curves in the presence of hypoinsulinaemia, hyperglucagonaemia, and reduced C-peptide values. The hormonal response after PDS transplantation was variable and the advantages of portal vs systemic insulin drainage remain to be defined. 相似文献