全文获取类型
收费全文 | 14312篇 |
免费 | 897篇 |
国内免费 | 46篇 |
专业分类
耳鼻咽喉 | 162篇 |
儿科学 | 762篇 |
妇产科学 | 308篇 |
基础医学 | 1630篇 |
口腔科学 | 417篇 |
临床医学 | 1008篇 |
内科学 | 3137篇 |
皮肤病学 | 270篇 |
神经病学 | 796篇 |
特种医学 | 581篇 |
外国民族医学 | 1篇 |
外科学 | 2146篇 |
综合类 | 412篇 |
一般理论 | 11篇 |
预防医学 | 834篇 |
眼科学 | 432篇 |
药学 | 1391篇 |
中国医学 | 90篇 |
肿瘤学 | 867篇 |
出版年
2023年 | 103篇 |
2022年 | 92篇 |
2021年 | 503篇 |
2020年 | 293篇 |
2019年 | 343篇 |
2018年 | 441篇 |
2017年 | 323篇 |
2016年 | 361篇 |
2015年 | 395篇 |
2014年 | 562篇 |
2013年 | 727篇 |
2012年 | 1016篇 |
2011年 | 1091篇 |
2010年 | 643篇 |
2009年 | 505篇 |
2008年 | 824篇 |
2007年 | 812篇 |
2006年 | 718篇 |
2005年 | 638篇 |
2004年 | 606篇 |
2003年 | 485篇 |
2002年 | 474篇 |
2001年 | 271篇 |
2000年 | 272篇 |
1999年 | 247篇 |
1998年 | 134篇 |
1997年 | 84篇 |
1996年 | 76篇 |
1995年 | 85篇 |
1994年 | 67篇 |
1993年 | 65篇 |
1992年 | 135篇 |
1991年 | 142篇 |
1990年 | 123篇 |
1989年 | 138篇 |
1988年 | 115篇 |
1987年 | 109篇 |
1986年 | 87篇 |
1985年 | 86篇 |
1984年 | 100篇 |
1983年 | 80篇 |
1982年 | 58篇 |
1980年 | 50篇 |
1979年 | 74篇 |
1977年 | 43篇 |
1976年 | 49篇 |
1974年 | 49篇 |
1973年 | 59篇 |
1972年 | 43篇 |
1969年 | 43篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
951.
Hereditary and acquired bisalbuminemia, in which the serum contains an albumin variant differing from albumin A by single amino-acid substitutions, have been reported in different races or ethnic groups and in association with various pathologic states. The importance of this rare condition in the pathophysiology of established diseases is uncertain. We evaluated a 68-year-old woman with chronic kidney disease who presented with worsened serum creatinine concentration despite lack of dietary or medical changes. Serum protein electrophoresis was performed with an automated rapid electrophoresis system. Bisalbuminemia was noted as an incidental finding on serum protein electrophoresis. The serum creatinine level stabilized with dietary protein restriction and a -blocking agent/diuretic combination for blood pressure control. Although the possibility that some physiologic or pharmacologic substances may not bind to abnormal albumin variants as well as they bind to normal albumin should not be discounted, the finding of bisalbuminemia did not influence the diagnosis, management, course, or prognosis of chronic kidney disease. The role of persistent bisalbuminemia in renal disease is uncertain. 相似文献
952.
The local tissue response of the biomaterial is the most important criteria for determination of its biocompatibility. In the present study, full and semi-interpenetrating polymer networks (IPN) based on polyacrylic acid (AAc) and gelatin (Ge) crosslinked with 0.5 mol % N,N'-methylene bisacrylamide (BAm) and 4% glutaraldehyde (GA), respectively, were evaluated for tissue response in rats. IPNs with varying ratios of AAc and Ge were implanted subcutaneously in rats. Gentamicin sulfate (GS)-loaded IPN samples were also studied to evaluate the possible therapeutic use of these polymers. The site of implantation was biopsied and processed for light microscopy (LM) with image analysis for assessment of tissue reaction at 2-, 6-, and 12-week intervals. The tissue reaction was evaluated as a function of composition and time. The degree of neutrophil, lymphocyte and macrophage infiltration, fibrosis, granuloma formation, integration with extracellular matrix, vascular proliferation, and damage of adjacent structures were assessed. Polymers with >66% crosslinked Ge (Gx) showed persistence of acute inflammatory reaction till 3 months, with marked tissue injury and fibrosis. On the other hand, high crosslinked AAc (Ax) content showed chronic inflammatory reaction with high macrophage infiltration. Macrophages took active part in phagocytosis, degradation, and removal of polymers without granuloma formation or significant giant cell reaction. The IPNs with acrylic acid and gelatin in the ratio of 1:1 showed least tissue reaction and thus appeared to be most biocompatible. The majority of the polymers showed integration with extracellular matrix and growth of capillaries in and around the polymer. The heamogram, liver and renal function tests, and histology of vital organs were all normal. GS loading showed no additional local or systemic reaction suggesting the potential usefulness of the hydrogels as carrier for drugs such as GS. 相似文献
953.
954.
Bhadani PP Sharma MC Agarwal A Sah SP Gupta AK 《Indian journal of pathology & microbiology》2004,47(2):253-255
Trichoblastoma is a rare benign skin appendage tumour with follicular differentiation. Pigmented variant of trichoblastoma is an extremely uncommon tumour and only three cases have been described in the literature. We report a rare case of pigmented trichoblastoma in a 54-year-old female. 相似文献
955.
Electron paramagnetic resonance (EPR) imaging in the continuous wave (CW) and time-domain modes, as well as Overhauser-enhanced magnetic resonance imaging in vivo is described. The review is based mainly on the CW and time-domain EPR instrumentation at 300 MHz developed in our laboratory, and the relative merits of these methods for functional in vivo imaging of small animals to assess hypoxia and tissue redox status are described. Overhauser imaging of small animals at magnetic fields in the range 10-15 mT that is being carried out in our laboratory for tumor imaging and the evaluation of tumor hypoxia based on quantitative evaluation of Overhauser enhancement is also described. Alternate approaches to spectral-spatial imaging using the transverse decay constants to infer in situ line widths and hence in vivo pO2 using CW and time-domain EPR imaging are also discussed. The nature of the spin probes used, the quality of the images obtained in all the three methods, the achievable resolution, limitations and possible future directions in small animal functional imaging with these modalities are summarized. 相似文献
956.
Background
The ACE gene contains a polymorphism consisting of either the presence (insertion, I) or absence (deletion, D) of a 287 bp alu repeat in intron 16. The D allele is associated with increased ACE activity in both tissue and plasma. The DD genotype is associated with risk of developing ARDS and mortality. The frequency of the D allele is higher in patients with pulmonary fibrosis, sarcoidosis and berylliosis. The role of this polymorphism has not been studied in the development of BPD in the premature newborn. 相似文献957.
Role of routine ultrasonography in monitoring the outcome of medical abortion in a clinical setting 总被引:3,自引:0,他引:3
Acharya G Haugen M Bråthen A Nilsen I Maltau JM 《Acta obstetricia et gynecologica Scandinavica》2004,83(4):390-394
BACKGROUND: Clinical methods generally used to evaluate the completeness of medical abortion are not accurate. There are no published reports evaluating the role of routine ultrasonography in monitoring the outcome of medical abortion. The purpose of this study was to investigate whether routine transvaginal ultrasonography (TVS) at the follow-up visit after medical abortion can accurately identify women who will require surgical intervention. DESIGN: Retrospective review of medical records and charts of all women undergoing medical abortion in the first trimester of pregnancy between January 1999 and December 2001. METHODS: Medical abortion was performed using oral mifepristone and a vaginal prostaglandin analog before 63 days gestation. All women had an initial TVS to confirm intrauterine pregnancy and gestational age, and another TVS at the follow-up visit 2-3 weeks later to assess the completeness of abortion. Surgical evacuation of the uterus was allowed as indicated on clinical grounds but not on the basis of ultrasound findings only. RESULTS: A total of 690 women consented to medical abortion during the study period. Eleven of these women were excluded from the study for various reasons. Of the remaining 679 cases, 95% (645/679) had a documented follow-up at the hospital. The pregnancy termination rate among these women was 99.2% (640/645) and TVS identified all five cases of continuing pregnancy at the follow-up. A total of 66 (10.2%) patients had complications. The uterine cavity was empty on TVS at the follow-up visit in 84.8% (547/645) of cases and only 3.1% (17/547) of them required surgical aspiration/curettage due to excessive or prolonged vaginal bleeding. In the remaining 15.2% (98/645) the uterine cavity was not empty, and 43.9% (43/98) of them had a curettage. The risk of requiring a surgical intervention was significantly higher [odds ratio (OR) 24.4; 95% confidence interval (95% CI) 14.9-39.7] when the uterine cavity was not demonstrated to be empty at the follow-up visit 2-3 weeks after medical abortion. However, 59.1% (55/93) of women did not require surgical intervention despite ultrasound evidence of thick endometrial echo-complex. CONCLUSION: Routine TVS 2-3 weeks after medical abortion appears to be an efficient means of accurately identifying the cases of ongoing pregnancy and diagnosing a complete abortion. Although TVS could be used as an adjunct to clinical examination to diagnose an incomplete expulsion, it does not accurately differentiate those women who require surgical intervention from those who do not. 相似文献
958.
Sofowora GG Dishy V Landau R Xie HG Prasad HC Byrne DW Smiley RM Kim RB Wood AJ Stein CM 《Clinical pharmacology and therapeutics》2004,75(6):539-545
OBJECTIVE: The alpha(1A)-adrenergic receptor is highly expressed in human vasculature including resistance arteries and veins, and its stimulation is primarily responsible for adrenergically mediated smooth muscle contraction. Variability in sensitivity to phenylephrine, an alpha(1A) adrenergic agonist, has a large genetic component. We examined the hypothesis that a common polymorphism of alpha(1A)-adrenergic receptor (Arg347Cys) affects in vivo response. METHODS: We measured vascular sensitivity to phenylephrine using the dorsal hand vein linear variable differential transformer technique and determined alpha(1A)-adrenergic receptor genotype in 74 healthy, nonsmoking adults (28 Arg/Arg, 30 Arg/Cys, and 16 Cys/Cys). RESULTS: Sensitivity to phenylephrine, expressed as the dose of phenylephrine resulting in 50% venoconstriction (Phe(50)), was not significantly different in subjects with the 3 alpha(1A) adrenergic receptor genotypes: Phe(50) geometric mean (95% confidence interval) was 513 ng/min (287-918 ng/min) for Arg/Arg, 431 ng/min (274-680 ng/min) for Arg/Cys, and 471 ng/min (197-1124 ng/min) for Cys/Cys (P =.90). CONCLUSION: We conclude that the Arg347Cys receptor polymorphism does not alter agonist-mediated venoconstriction in vivo. 相似文献
959.
Yamaji K Sarker KP Abeyama K Maruyama I 《International journal of food sciences and nutrition》2004,55(1):61-66
It has been suggested that oxidation of low-density lipoprotein (LDL) plays an important role in the initiation and progression of atherosclerosis. In the present study, we determined the anti-atherogenic effects of egg yolk-enriched garlic powder (EGP), which has been used as a traditional health-promoting food in southern Japan since ancient times, on LDL oxidation and oxidant stress-induced cell injury models. We confirmed that EGP inhibits copper-induced LDL oxidation in a dose-dependent manner. We also observed that pretreatment of EGP significantly suppressed the production of peroxides in HL60 cells and protected endothelial cells from hydrogen peroxide-induced cell injury. These findings might, in part, be ascribed to the biodistribution of garlic compounds and egg yolk interaction, and suggest that EGP might be useful in the prevention of atherosclerosis. 相似文献
960.
SR Mehta VSM HRA Prabhu AJ Swamy Harinder Dhaliwal Dinesh Prasad 《Medical Journal Armed Forces India》2004,60(1):25-27
The varied clinical manifestations and management of 14 male patients with delirium tremens (DT) have been studied. Eight patients were initially hospitalised for diseases unrelated to ethanol abuse i.e. 2 each for gun shot wound, myocardial infarction and stroke, and one each for pneumonia and gastroenteritis. One patient was going through withdrawal because of prodrome of viral hepatitis before he was hospitalised for uncontrolled agitation and delirium. Two known cases of mild essential hypertension on dietary therapy reported for agitation, abnormal behaviour, a single episode of tonic clonic seizure and hypertensive encephalopathy as they could not/did not get alcohol for 3 days. Three patients presented denovo with DT without concomitant illness. The other features besides delirium and hallucinations were tremulousness in 10, tachycardia in 12, fever in 3, diaphoresis in 2 and tonic clonic seizures in 4 patients. The symptoms fluctuated markedly at short intervals and 2 patients did not have any features of sympathetic overactivity. Altered hepatic biochemical parameters and ketonuria with normal blood sugar were noted in 4 and one patients respectively. Other biochemical parameters including serum electrolytes were normal. CT scan brain done for 5 patients revealed subdural haematoma in one. Cerebro spinal fluid (CSF) and EEG findings were noncontributory. All made good recovery with heavy doses of intravenous vitamin B complex, glucose and oral benzodiazepine. Short course of haloperidol was used in 2 patients. Two patients developed pancreatitis during follow up. All patients made complete recovery, and 8 patients have been followed for 8 to 12 months without relapse. The reason for hospitalisation in such cases is often unrelated to alcohol abuse; hence a detailed history of alcoholism is mandatory to identify those at risk as well as for prompt treatment and decreasing the mortality.Key Words: Alcohol withdrawal, Concomitant illnesses, Delirium, Precipitating events 相似文献