全文获取类型
收费全文 | 1894篇 |
免费 | 137篇 |
国内免费 | 13篇 |
专业分类
耳鼻咽喉 | 16篇 |
儿科学 | 104篇 |
妇产科学 | 23篇 |
基础医学 | 176篇 |
口腔科学 | 45篇 |
临床医学 | 251篇 |
内科学 | 399篇 |
皮肤病学 | 13篇 |
神经病学 | 134篇 |
特种医学 | 81篇 |
外科学 | 326篇 |
综合类 | 64篇 |
预防医学 | 170篇 |
眼科学 | 66篇 |
药学 | 115篇 |
中国医学 | 2篇 |
肿瘤学 | 59篇 |
出版年
2022年 | 21篇 |
2021年 | 45篇 |
2020年 | 27篇 |
2019年 | 34篇 |
2018年 | 31篇 |
2017年 | 27篇 |
2016年 | 29篇 |
2015年 | 31篇 |
2014年 | 48篇 |
2013年 | 48篇 |
2012年 | 94篇 |
2011年 | 89篇 |
2010年 | 75篇 |
2009年 | 40篇 |
2008年 | 89篇 |
2007年 | 92篇 |
2006年 | 90篇 |
2005年 | 83篇 |
2004年 | 72篇 |
2003年 | 70篇 |
2002年 | 78篇 |
2001年 | 56篇 |
2000年 | 70篇 |
1999年 | 64篇 |
1998年 | 33篇 |
1997年 | 42篇 |
1996年 | 28篇 |
1995年 | 21篇 |
1994年 | 21篇 |
1993年 | 23篇 |
1992年 | 55篇 |
1991年 | 54篇 |
1990年 | 37篇 |
1989年 | 32篇 |
1988年 | 26篇 |
1987年 | 35篇 |
1986年 | 27篇 |
1985年 | 23篇 |
1984年 | 11篇 |
1983年 | 14篇 |
1982年 | 8篇 |
1981年 | 10篇 |
1980年 | 9篇 |
1979年 | 24篇 |
1978年 | 12篇 |
1977年 | 9篇 |
1972年 | 12篇 |
1971年 | 11篇 |
1970年 | 9篇 |
1966年 | 10篇 |
排序方式: 共有2044条查询结果,搜索用时 15 毫秒
11.
Studies were conducted relating mosquito production in small ponds to presence or absence of larvivorous fishes. Data collected showed that native killifish and introduced mosquitofish controlled mosquito larvae at the same level and support the use of indigenous fish species in mosquito abatement programs. 相似文献
12.
Fifty adult patients who sustained a traumatic brain injury (TBI) were screened for the presence of a peripheral nerve injury (PNI). All suspected patients had diagnostic electromyography performed in order to confirm the clinical findings. The incidence of PNI with TBI was 34%. A variety of nerve injuries were seen, the most frequent of which were ulnar nerve entrapment at the elbow (10%) and brachial plexus injuries (10%). No patient initiated a complaint that led to the diagnosis. In addition, all the neuropathies were missed prior to admission. The neuropathies commonly were found in the neurologically impaired extremity and associated with spasticity. The results of this study suggest that patients sustaining a TBI have a significant and higher incidence of PNI as a complication than previously reported. 相似文献
13.
14.
15.
One-hundred consecutive patients were prospectively evaluated on admission to our Brain Injury Unit for signs and symptoms of reflex sympathetic dystrophy (RSD) in the upper extremity. Patients averaged 4 months postinjury and had an average age of 29 years. Thirteen patients had clinical signs and symptoms of RSD and were then evaluated with standard radiographs and 3-phase radionuclide scintigraphy. Twelve of 13 patients had 3-phase bone scans (TPBS) consistent with RSD (12% overall incidence). RSD was present exclusively in the spastic upper extremity. There were 9 patients with hemiparesis and 3 with quadraparesis. There was a significantly higher (P < 0.01) incidence of associated upper extremity injury in the group with RSD (75%). All patients had a mean Rancho Cognitive Level of V and initial Glasgow Coma Scores less than 8. Patients who developed RSD had lower Glasgow Coma Scores than the non-RSD patients. Brain-injured patients often display agitation, hyperalgesia, disuse or neglect of the RSD-involved extremity. In addition, these patients are often cognitively unable to vocalize complaints of pain. Undiagnosed RSD in these patients can result in a significant delay in rehabilitation and possible loss of the use of an otherwise functional upper extremity. 相似文献
16.
17.
Ignatius KP CHENG 《Nephrology (Carlton, Vic.)》1997,3(1):109-111
Summary: The involvement of the IgA immune system and complement components in IgA glomerulonephritis (IgAGN) has prompted the use of immunosuppressive drugs in therapy, but none has so far been shown to alter the natural course of the disease. Because most patients with IgAGN present during the chronic phase of their illness, at the time when the initiating immune events may no longer be active, nonimmune therapy which targets the common pathway of progressive renal injury is likely to be more useful. There is increasing evidence that angiotensin-converting enzyme inhibitors (ACEI) reduce proteinuria and renal injury in patients with IgAGN, and this effect may be observed in both normotensive and hypertensive patients. Yet to be determined is whether this effect is specific for ACEI and whatever other effective antihypertensive drugs may achieve a similar result. Fish oil has recently been shown to retard the progression of renal failure in patients with aggressive IgAGN, but a narrow therapeutic window appears to exist for this form of treatment. Antiplatelet agents on their own appear to be ineffective but in combination with anticoagulation (low dose warfarin) have been shown to have an antiproteinuric effect and may preserve renal function in patients with progressive disease. Future directions of non-immune therapy of IgAGN include evaluation of the renoprotective effect of angiotensin II receptor antagonists, free-radical scavengers and antilipid drugs. More work should also be done to identify factors which put the patients at risk of developing progressive disease and which predict therapeutic response, as has been done recently with the identification of the deletion polymorphism of the angiotensin-converting enzyme gene as a marker of progressive disease and therapeutic response to ACEI in patients with IgAGN. 相似文献
18.
J L Mulshine A M Keenan J A Carrasquillo T Walsh R I Linnoila O D Holton J Harwell S M Larson P A Bunn J N Weinstein 《Cancer research》1987,47(13):3572-3576
Despite improved resolution with new imaging techniques, surgical confirmation of mediastinal lymph node status is often required for reliable staging of patients with non-small cell lung cancer. Recent scintigraphic studies suggest that s.c. administration of radiolabeled antibodies can be more efficient than the i.v. route for targeting regional lymph nodes in animals and humans. To determine if this approach could be applied to the lymphatics of the lung, we injected both specific and irrelevant radiolabeled monoclonal antibodies via a flexible fiberoptic bronchoscope through the mucosa of lobar bronchi in normal dogs. The injected antibodies were expected to drain by way of local lymphatic vessels toward the central lymph nodes, in effect following the same pathway as do cells metastasizing to these nodes during early regional tumor dissemination. To accomplish this, anesthetized dogs were intubated and then coinjected with the two labeled antibodies [600 microCi/100 micrograms (total)] through a fiberoptic bronchoscope. The animals were serially imaged and then autopsied 14-36 h after injection. Individual hilar and carinal nodes contained over 1% of the injected 131I-labeled specific antibody dose and the average selectivity was 2.5:1 with respect to a coinjected irrelevant IgG. Distant organs (mesenteric lymph node, liver, spleen, bone marrow, and lung parenchyma other than the injection site) contained much less radioactivity, and those sites accumulated a greater fraction of the non-specific labeled antibody. The ratio of iodine-131 to iodine-125 counts between hilar/carinal lymph nodes and abdominal lymph nodes ranged from 15:1 to 100:1. These initial studies indicate efficient delivery of antibody to a subset of the regional nodes via pulmonary lymphatics. They suggest the feasibility of this technique which may be of use in the detection and perhaps therapy of human lung cancer metastases in regional lymph nodes. 相似文献
19.
20.
Exacerbation of experimental colitis by nonsteroidal anti-inflammatory drugs is not related to elevated leukotriene B4 synthesis. 总被引:6,自引:0,他引:6
The ability of nonsteroidal anti-inflammatory drugs to exacerbate experimental colitis, and the possible contributions of the "shunting" of arachidonate via the 5-lipoxygenase pathway, were investigated using a rat model in which colitis was induced by intracolonic administration of trinitrobenzene sulfonic acid in a vehicle of 50% ethanol. Twice daily treatment with indomethacin (0.1-1 mg/kg SC) during the first week after trinitrobenzene sulfonic acid/ethanol administration resulted in dose-dependent increases in the severity of colitis and in the incidence of mortality. Mortality was not observed in vehicle-treated colitic rats or in normal rats treated with indomethacin. Similar exacerbation of colitis was observed in rats treated with naproxen (5 mg/kg). Whereas treatment with a 5-lipoxygenase inhibitor, PF-5901 (100 mg/kg PO), resulted in a significant reduction of the severity of colitis, concomitant administration of PF-5901 and indomethacin (0.5 mg/kg SC) did not inhibit the exacerbative effects of the indomethacin in this model. In separate studies, administration of indomethacin was found to significantly increase colonic myeloperoxidase activity (a measure of tissue granulocyte numbers) and suppress colonic prostaglandin E2 synthesis, while not significantly affecting colonic leukotriene B4 synthesis. The effect on myeloperoxidase activity was seen during the period 21-24 hours after trinitrobenzene sulfonic acid ethanol administration, but not during the period 45-48 hours after induction of colitis. In in vitro studies using samples of inflamed colon and in vivo studies in which colonic eicosanoid production was measured by colonic dialysis, inhibition of prostaglandin E2 synthesis was not accompanied by significant changes in leukotriene B4 synthesis. These results suggest that inhibitors of colonic prostaglandin synthesis can markedly exacerbate colitis, and that this effect is unrelated to alterations in colonic leukotriene B4 synthesis. Endogenous prostaglandins may exert anti-inflammatory effects during the acute stages of colitis. 相似文献