全文获取类型
收费全文 | 15344篇 |
免费 | 1258篇 |
国内免费 | 75篇 |
专业分类
耳鼻咽喉 | 248篇 |
儿科学 | 417篇 |
妇产科学 | 146篇 |
基础医学 | 1872篇 |
口腔科学 | 196篇 |
临床医学 | 1905篇 |
内科学 | 3381篇 |
皮肤病学 | 168篇 |
神经病学 | 1416篇 |
特种医学 | 511篇 |
外国民族医学 | 7篇 |
外科学 | 2776篇 |
综合类 | 192篇 |
一般理论 | 9篇 |
预防医学 | 1451篇 |
眼科学 | 208篇 |
药学 | 934篇 |
1篇 | |
中国医学 | 20篇 |
肿瘤学 | 819篇 |
出版年
2023年 | 81篇 |
2022年 | 113篇 |
2021年 | 327篇 |
2020年 | 175篇 |
2019年 | 300篇 |
2018年 | 353篇 |
2017年 | 290篇 |
2016年 | 279篇 |
2015年 | 350篇 |
2014年 | 513篇 |
2013年 | 698篇 |
2012年 | 1024篇 |
2011年 | 1111篇 |
2010年 | 596篇 |
2009年 | 538篇 |
2008年 | 992篇 |
2007年 | 1122篇 |
2006年 | 1029篇 |
2005年 | 1002篇 |
2004年 | 893篇 |
2003年 | 827篇 |
2002年 | 795篇 |
2001年 | 236篇 |
2000年 | 201篇 |
1999年 | 191篇 |
1998年 | 151篇 |
1997年 | 125篇 |
1996年 | 107篇 |
1995年 | 113篇 |
1994年 | 90篇 |
1993年 | 94篇 |
1992年 | 140篇 |
1991年 | 136篇 |
1990年 | 177篇 |
1989年 | 109篇 |
1988年 | 98篇 |
1987年 | 114篇 |
1986年 | 105篇 |
1985年 | 113篇 |
1984年 | 73篇 |
1983年 | 78篇 |
1982年 | 43篇 |
1981年 | 51篇 |
1980年 | 46篇 |
1979年 | 80篇 |
1978年 | 57篇 |
1977年 | 45篇 |
1976年 | 39篇 |
1975年 | 38篇 |
1974年 | 49篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
31.
Todd W Kelley Ernest C Borden John R Goldblum 《Applied immunohistochemistry & molecular morphology》2004,12(4):338-341
The authors have noted anecdotal cases of extrauterine leiomyosarcomas (LMS) with estrogen receptor (ER) and progester-one receptor (PR) immunoreactivity. However, there are few studies that have compared ER and PR immunoexpression in LMS of uterine and extrauterine origin. The authors obtained a representative formalin-fixed, paraffin-embedded tissue block from cases of uterine LMS (n = 15) and extrauterine LMS (n = 16) from the archives of the Cleveland Clinic Foundation and performed immunohistochemical staining for ER and PR. Staining was evaluated by 2 observers in a semiquantitative manner using the following scale: 0, no nuclear staining; 1+, 1 to 25% of nuclei stained; 2+, 26 to 50% of nuclei stained; 3+, 51 to 75% of nuclei stained; 4+, 76 to 100% of nuclei stained. The majority of uterine LMS stained for ER (13 of 15, 87%), PR (12 of 15, 80%), or both ER and PR (12 of 15, 80%), with most cases showing 3+ or 4+ positive staining. For the extrauterine LMS cases, staining for ER was seen in 4 of 16 cases (25%), staining for PR was observed in 2 of 16 cases (13%), and staining for both ER and PR was seen in 2 of 16 cases (13%). One extrauterine LMS showed 4+ coexpression of ER and PR, but the remaining extrauterine cases showed only 1+ ER and/or PR immunoreactivity. These data suggest that most uterine LMS coexpress ER and PR, and most extrauterine LMS do not stain for these antigens. However, a subset of extrauterine LMS are ER and/or PR immunoreactive. This raises the possibility that hormonal manipulation may be beneficial in the treatment of these therapeutically recalcitrant tumors. 相似文献
32.
33.
Renal, cerebral, and pulmonary effects of hypertonic resuscitation in a porcine model of hemorrhagic shock 总被引:2,自引:0,他引:2
To determine the safety and efficacy of a hypertonic solution for hypovolemic resuscitation, we compared the acute and delayed effects of hypertonic sodium lactate solution (514 mOsm) to Ringer's lactate solution (274 mOsm) in a porcine model of hemorrhagic shock. Cardiovascular, pulmonary, renal, and cerebral functions were examined in mature swine after their blood volume had been reduced by 40%. Hemorrhage produced significant decreases in blood pressure, cardiac output, and creatinine clearance, which were reversed with resuscitation. Resuscitation with Ringer's lactate solution required significantly more fluid and produced a significantly greater increase in intracranial pressure than did hypertonic sodium lactate solution. HSL produced significant increases in serum sodium and osmolality, which resolved within 48 hours. Hypernatremia and hyperosmolality were not associated with renal or cerebral dysfunction and were corrected through increased sodium excretion, free water intake, and a negative free water clearance. 相似文献
34.
35.
Halothane anesthetized Sprague-Dawley rats underwent 10 min of bilateral carotid artery occlusion with mean arterial pressure (MAP) held at 30, 50 or 60 mmHg. Sham rats did not undergo ischemia. A 7-day recovery interval was allowed. Intra-ischemic electroencephalographic (EEG) changes, behavioral function (Days 5-7), and histologic injury (Day 7) were evaluated. Under similar conditions, cerebral blood flow was determined after 10 min ischemia by the [3H]nicotine indicator fractionation technique. EEG isoelectricity was observed in 11 of 11, 5 of 10, and 2 of 11 rats in the 30 mmHg, 50 mmHg, and 60 mmHg groups respectively. Neither passive avoidance cross-over latencies nor general motor scores were affected by intra-ischemic MAP and no differences from sham performance were observed. The per cent of CA1 neurons counted as dead (left and right hemispheres combined) was significantly affected by intra-ischemic MAP (72, 46 and 28% in the 30 mmHg, 50 mmHg, and 60 mmHg groups, respectively; P less than 0.001). A greater than 50% CA1 neuronal mortality rate was present only in those rats exhibiting EEG isoelectricity. However, the number of rats demonstrating greater than a 25% interhemispheric difference in CA1 neuronal loss was greatest in the 50 mmHg group (P less than 0.02). Hippocampal blood flow decreased in association with severity of hypotension (8 +/- 1, 35 +/- 8, and 48 +/- 2 ml/100 g/min (mean +/- S.E.M.) for 30, 50, and 60 mmHg, respectively; P less than 0.01). Again, however, the greatest variability in blood flow was observed at MAP = 50 mmHg.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
36.
J L Arriza T M Dawson R B Simerly L J Martin M G Caron S H Snyder R J Lefkowitz 《The Journal of neuroscience》1992,12(10):4045-4055
The beta-adrenergic receptor kinase (beta ARK) phosphorylates the agonist-occupied beta-adrenergic receptor to promote rapid receptor uncoupling from Gs, thereby attenuating adenylyl cyclase activity. Beta ARK-mediated receptor desensitization may reflect a general molecular mechanism operative on many G-protein-coupled receptor systems and, particularly, synaptic neurotransmitter receptors. Two distinct cDNAs encoding beta ARK isozymes were isolated from rat brain and sequenced. The regional and cellular distributions of these two gene products, termed beta ARK1 and beta ARK2, were determined in brain by in situ hybridization and by immunohistochemistry at the light and electron microscopic levels. The beta ARK isozymes were found to be expressed primarily in neurons distributed throughout the CNS. Ultrastructurally, beta ARK1 and beta ARK2 immunoreactivities were present both in association with postsynaptic densities and, presynaptically, with axon terminals. The beta ARK isozymes have a regional and subcellular distribution consistent with a general role in the desensitization of synaptic receptors. 相似文献
37.
The incidence of Type 1 diabetes is increasing worldwide, imposing enormous public health costs, as well as profoundly affecting individual quality of life. There is evidence that psychological problems are increased in children with diabetes and this morbidity is often associated with poor metabolic control. Specific risk factors for this dual morbidity are emerging from empirical studies. The next challenge is to identify effective interventions for use with children at risk for adverse mental and physical health outcomes. The intervention literature is reviewed. It is noted that most studies have used diabetes-specific, unstandardized interventions in groups of adolescents, with few interventions trialled with younger children. No study has targeted a specific psychological disorder such as behaviour problems or depression, both of which are known to be increased in children with diabetes and for which effective standardized interventions are available. Attention is drawn to methodological limitations in many of the studies conducted to date and suggestions made to reduce these in future interventions attempting to reduce the burden of illness in children with diabetes. 相似文献
38.
Nitrous oxide anesthesia has been implicated as contributing to the development of delayed tension pneumocephalus following surgery performed in the sitting position. The authors tested the hypothesis that withdrawal of nitrous oxide anesthesia administered during formation of an intracranial gas cavity would lead to a decrease in intracranial pressure (ICP) as N2O diffuses from the cavity back into the blood. Ten halothane-anesthetized rabbits were prepared for measurement of supracortical ICP and arterial blood pressure (BP) and for intracranial volume alterations via a cisterna magna infusion catheter. Hyperventilation (Paco2 = 28-30 mmHg) and mannitol were used to shrink the brain to accommodate intracranial infusion of either air or lactated Ringer's (LR) solution, which was used to elevate ICP to between 10-15 mmHg from a baseline ICP of 2.1 +/- 2.5 mmHg over a period of 8 to 10 min. Following stabilization at an elevated ICP, inhalation of nitrous oxide (75%) was either initiated or withdrawn (if already present during the induced ICP increase) and the subsequent changes in mean ICP and BP were recorded. Following ICP elevation with LR to 10 +/- 1 mmHg, initiation of 75% N2O administration resulted in no change in ICP and modest increases (P less than 0.05) in BP and cerebral perfusion pressure (CPP = BP - ICP) after 4 min. However, when ICP was raised (to 12 +/- 3.5 mmHg) with intracranial air infusion, subsequent initiation of 75% N2O inhalation caused an abrupt ICP increase to 22.3 +/- 9 mmHg (from control P less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
39.
Combined open and laparoscopic approach to chronic pain following open inguinal hernia repair 总被引:1,自引:0,他引:1
Introduction: Chronic groin pain is the most common long-term complication after open inguinal hernia repair. Traditional surgical management
of the associated neuralgia consists of injection therapy followed by groin exploration, mesh removal, and nerve transection.
The resultant hernia defect may be difficult to repair from an anterior approach. We evaluate the outcomes of a combined laparoscopic
and open approach for the treatment of chronic groin pain following open inguinal herniorrhaphy. Methods: All patients who underwent groin exploration for chronic neuralgia after a prior open inguinal hernia repair were prospectively
analyzed. Patient demographics, type of prior hernia repair, and prior nonoperative therapies were recorded. The operation
consisted of a standard three trocar laparoscopic transabdominal preperitoneal hernia repair, followed by groin exploration,
mesh removal, and nerve transection. Outcome measures included recurrent groin pain, numbness, hernia recurrence, and complications.
Results: Twelve patients (11 male and 1 female) with a mean age of 41 years (range 29–51) underwent combined laparoscopic and open
treatment for chronic groin pain. Ten patients complained of unilateral neuralgia, one patient had bilateral complaints, and
one patient complained of orchalgia. All patients failed at least two attempted percutaneous nerve blocks. Prior repairs included
Lichtenstein (n=9), McVay (n=1), plug and patch (n=1), and Shouldice (n=1). There were no intraoperative complications or wound infections. With a minimum of 6 weeks follow up, all patients were
significantly improved. One patient complained of intermittent minor discomfort that required no further therapy. Two patients
had persistent numbness in the ilioinguinal nerve distribution but remained satisfied with the procedure. Conclusions: A combined laparoscopic and open approach for postherniorrhaphy groin pain results in good to excellent patient satisfaction
with no perioperative morbidity. It may be the preferred technique for the definitive management of chronic neuralgia after
prior open hernia repair. 相似文献
40.
R. Parker Ward MD Mouaz H. Al-Mallah MD Gabriel B. Grossman MD PhD Christopher L. Hansen MD Robert C. Hendel MD Todd C. Kerwin MD Benjamin D. McCallister Jr MD Rupa Mehta MD Donna M. Polk MD MPH Peter L. Tilkemeier MD Aseem Vashist MD Kim Allan Williams MD David G. Wolinsky MD Edward P. Ficaro PhD 《Journal of nuclear cardiology》2007,14(6):911-e38