全文获取类型
收费全文 | 1999篇 |
免费 | 151篇 |
国内免费 | 10篇 |
专业分类
耳鼻咽喉 | 10篇 |
儿科学 | 56篇 |
妇产科学 | 59篇 |
基础医学 | 295篇 |
口腔科学 | 36篇 |
临床医学 | 228篇 |
内科学 | 451篇 |
皮肤病学 | 39篇 |
神经病学 | 151篇 |
特种医学 | 69篇 |
外科学 | 287篇 |
综合类 | 28篇 |
一般理论 | 1篇 |
预防医学 | 163篇 |
眼科学 | 23篇 |
药学 | 120篇 |
中国医学 | 2篇 |
肿瘤学 | 142篇 |
出版年
2023年 | 17篇 |
2022年 | 30篇 |
2021年 | 68篇 |
2020年 | 35篇 |
2019年 | 59篇 |
2018年 | 76篇 |
2017年 | 52篇 |
2016年 | 57篇 |
2015年 | 58篇 |
2014年 | 77篇 |
2013年 | 128篇 |
2012年 | 151篇 |
2011年 | 175篇 |
2010年 | 90篇 |
2009年 | 84篇 |
2008年 | 101篇 |
2007年 | 123篇 |
2006年 | 104篇 |
2005年 | 75篇 |
2004年 | 76篇 |
2003年 | 70篇 |
2002年 | 58篇 |
2001年 | 35篇 |
2000年 | 47篇 |
1999年 | 29篇 |
1998年 | 17篇 |
1997年 | 13篇 |
1996年 | 8篇 |
1995年 | 8篇 |
1994年 | 7篇 |
1992年 | 20篇 |
1991年 | 15篇 |
1990年 | 18篇 |
1989年 | 9篇 |
1988年 | 13篇 |
1987年 | 14篇 |
1986年 | 15篇 |
1985年 | 8篇 |
1984年 | 10篇 |
1983年 | 6篇 |
1982年 | 5篇 |
1981年 | 10篇 |
1979年 | 5篇 |
1976年 | 5篇 |
1975年 | 6篇 |
1973年 | 7篇 |
1972年 | 7篇 |
1969年 | 5篇 |
1967年 | 5篇 |
1965年 | 5篇 |
排序方式: 共有2160条查询结果,搜索用时 62 毫秒
11.
S. G. Ronan I. Uzoaru V. Nadimpalli J. Guitart J. R. Manaligod 《Journal of cutaneous pathology》1993,20(3):223-228
We report seven cases of primary cutaneous phaeohyphomycosis. There were five males and two females, ranging in age from 42–65 years (mean 57.7 years). Two patients were otherwise healthy, but five were immunocompromised. One patient had rheumatoid arthritis and was on oral prednisone; two were renal transplant recipients, one was a heart transplant recipient, and the fifth had dermatomyositis. No history of trauma was elicited from any of the patients, but in two cases, foreign material was seen in the tissue sections. All lesions were oil the extremities. In two cases, tissues were cultured, and these grew Exophiala jean-selmei . The others were not cultured because fungal infection was not clinically suspected. No systemic disease developed in any of the cases, and all were cured by the simple, complete excision of the lesions. 相似文献
12.
Rajiv Jalan Rebecca Gooday Ronan E. O'Carroll Doris N. Redhead Robert A. Elton Peter C. Hayes 《Journal of hepatology》1995,23(6)
Background/Aims: This study was designed to assess changes in: (a) neuropsychological tests, measures of memory, quality of life and scores for anxiety and depression; (b) liver function tests; and (c) the relationship between these following transjugular intrahepatic portosystemic stent-shunt.Methods: Twenty-nine patients undergoing transjugular intrahepatic portosystemic stent-shunt for recurrent variceal haemorrhage, 12 matched patients with cirrhosis and variceal haemorrhage manage with variceal band ligation and 16 normal controls were studied. Patients in any of the groups who were clinically encephalopathic were excluded from the study. Serial changes in the conventional liver function tests and Indocyanine green clearance, and psychometric function (Hospital Anxiety Depression Scale, Rivermead Behavioral Memory Test, Quality of Life and the memory and reaction sub-tests of the Cambridge Automated Neuropsychological Test Assessment Battery) were measured prior to and 1, 3, 9 and 15 months following transjugular intrahepatic portosystemic stent-shunt.Results: Over a mean follow up of 9.1 months in the transjugular intrahepatic portosystemic stent-shunt group (range 3–28), one patient (3%) developed clinically detectable encephalopathy. Sixty-seven percent of patients with cirrhosis showed evidence of subclinical encephalopathy as compared with the control population. Significant deterioration occurred in the reaction sub-tests of the Cambridge Automated neuropsychological Test Assessment Battery in patients, both in the transjugular intrahepatic portosystemic stent-shunt group and the controls with cirrhosis, during follow up. Transjugular intrahepatic portosystemic stent-shunt was followed by significant deterioration in levels of anxiety and psychological component of the quality of life. The Rivermead Behavioural Memory Test and the memory sub-test of the Cambridge Automated Neurpsychological Test Assessment Battery did, however, improve significantly at 1 and 15 months after transjugular intrahepatic portosystemic stent-shunt, respectively. Serum alanine aminotransferase, bilirubin and indocyanine green clearance deteriorated significantly following transjugular intrahepatic portosystemic stent-shunt (p<0.001, p<0.001 and p<0.0001, respectively). Significant correlation was observed between changes in the indocyanine green clearance and changes in the complex and simple reaction time subtests of the Cambridge Automated Neuropsychological Test Assessment Battery (r=0.6 and r=0.66, respectively).Conclusions: The results of this study showed that about 67% of patients with cirrhosis were subclinically encephalopathic and that temporary deterioration occurred in the Cambridge Automated Neuropsychological Test Assessment Battery during follow up, both in patients having transjugular intrahepatic portosystemic stent-shunt and in the controls with cirrhosis. These parallel the changes in the liver function tests and indocyanine green clearance. Temporary deterioration was also observed in the Quality of Life and Hospital Anxiety Depression Scale in the transjugular intrahepatic portosystemic stent-shunt group, although the measures of memory improved. Further studies should address the biochemical mechanisms of these changes and the role of prophylactic measures. 相似文献
13.
Central serotonin (5-HT) metabolism during embryogenesis and a 3-day post-hatching period was analyzed using high performance liquid chromatography in the directly developing frog, Eleutherodactylus coqui. This anuran bypasses the free-swimming larval stage and embryos hatch as miniature frogs in the adult phenotype. During embryogenesis and for a short time immediately after hatching, male E. coqui provide paternal care by brooding and guarding eggs/embryos to prevent desiccation and predation. Serotonin and its catabolite, 5-HIAA, were measured from whole brain during embryogenesis and at 3 days post-hatch to identify critical periods in 5-HT development and to determine the relationship between 5-HT and life history events such as hatching and frog dispersal from the nest site. Serotonergic activity was highest during the early-mid embryonic stages as indicated by the ratio of 5-HIAA/5-HT, a general indicator of turnover and metabolism. There were significant increases in tissue concentrations of 5-HT during the latest or terminal embryonic stage, just prior to hatching, and also at 3 days post-hatch, shortly before neonates disperse into the rainforest. These two increases probably represent different functional requirements during development. The first may occur as a result of the surge of development in the 5-HT system during late embryogenesis that occurs in E. coqui and the second may be from the increase demand in sensory and motor neural development required before dispersal from the nest site. 相似文献
14.
Effects of learned helplessness on brain GABA receptors 总被引:2,自引:0,他引:2
GABA is involved in both clinical depression and in animal models of depression; however, the roles of GABA(A) and GABA(B) receptors in specific brain regions are not clear. Changes in densities of both GABA(A) and GABA(B) receptors have been reported with the learned helplessness animal model of depression and with chronic antidepressant drug treatment. However, some of these findings are discrepant. Thus, we used quantitative autoradiography to study the GABA(A) and GABA(B) receptors in learned helplessness and we used an experimental paradigm that allows non-specific effects of stress to be differentiated from learned helplessness. Densities of GABA binding were measured in prefrontal cortex, septum, hippocampus, hypothalamus and amygdala. In the septum, learned helpless rats had increased densities of GABA(A) receptors and rats that did not become helpless after inescapable stress had decreased GABA(B) receptor densities. No significant group differences of GABA(A) or GABA(B) receptor densities were observed in any other brain region studied. These results suggest a unique role for the septum in modulating GABA in the learned helplessness animal model of depression. 相似文献
15.
Barbari A Stephan A Masri M Karam A Aoun S El Nahas J Bou Khalil J 《Molecular immunology》2003,39(17-18):1109-1114
Consanguineous marriages are common in many countries of the Middle East including Lebanon. Their impact on the repartition of kidney diseases and on the risk for familial nephritis is not known. We surveyed all of the dialysis centers in Lebanon. Nine hundred and twenty-five (925) patients and their private physicians were asked to answer a questionnaire. More than half of the hemodialysis (HD) patients had an unknown etiology of their kidney disease. Diabetes, polycystic kidney disease (PKD), chronic pyelonephritis and nephrosclerosis (NS) were the most commonly documented diagnoses. Consanguinity was present in 26% of the total HD population. More consanguineous patients with unknown renal etiology were diagnosed with their kidney diseases and initiated on dialysis before the age of 30 when compared with their non-consanguineous counter-parts (45% versus 33%, P<0.02 and 42% versus 27%, P<0.01), respectively. Similarly, consanguineous polycystic patients were diagnosed and started earlier on dialysis when compared with the non-consanguineous population (34% versus 12%, P<0.05 and 28% versus 8%, P<0.05), respectively suggesting a different disease pattern. Furthermore, the risk for family history of kidney disease was noticeable in the non-consanguineous population and significantly higher among the consanguineous patients (12% versus 18%, P<0.04). Consanguinity-associated kidney diseases affected all religious communities, in particular the Muslim and the Druze (36 and 39%), respectively versus 17% of the Christian community. Certain geographical areas were more involved than others such as the North, South and the Bekaa with the highest percentage (40%) in the latter. Socio-economical level was not a contributing factor. We conclude that the documentation of the underlying etiology in end-stage renal diseases (ESRD) seems to be deficient. Furthermore, consanguinity is prevalent in the Lebanese dialysis patients population, in particular the Muslim and the Druze communities. Consanguinity-associated kidney diseases pattern seems to differ from that of the general HD population by disease diagnosis and initiation at a younger age and a significantly higher risk for familial renal disease. It is a cultural phenomenon prevalent predominantly in the rural areas. We recommend a multi-approach including educational, informative and probably legislative strategy in order to limit and hopefully discourage consanguineous marriages. 相似文献
16.
Reduced expression of cyclooxygenase (COX) in idiopathic pulmonary fibrosis and sarcoidosis 总被引:3,自引:0,他引:3
AIMS: To test the hypothesis that cyclooxygenase (COX)-1 or COX-2 expression is defective in lungs in idiopathic pulmonary fibrosis (IPF) and to characterize the cellular distribution. IPF is a progressive inflammatory lung disorder with an adverse prognosis. Previous work has shown that prostaglandin E2 (PGE2) regulates collagen deposition and fibroblast proliferation and a defect in COX regulation may contribute to the fibrosis that occurs in IPF. METHODS: Immunohistochemistry was utilized to determine COX immunoreactivity in lung sections from 25 IPF, six sarcoidosis and 14 control subjects. RESULTS: COX-1 and COX-2 expression in bronchiolar epithelial cells was significantly lower in IPF and sarcoidosis than in controls. No significant difference was found in COX-2 expression between macrophages in IPF and control sections, but COX-2 was reduced in macrophages in sarcoidosis compared with controls. CONCLUSIONS: These studies confirm COX-2 loss in bronchial epithelial cells but not macrophages in IPF, and show for the first time reduced constitutive COX-1 expression in epithelial cells and macrophages. Similar abnormalities were observed in sarcoidosis. 相似文献
17.
I Oberlé J Boué M F Croquette M A Voelckel M G Mattei J L Mandel 《American journal of medical genetics》1992,43(1-2):224-231
We report on 3 families where the presence and segregation at high frequency of a fragile Xq27.3 site is not associated with the mutations and methylation anomalies typically seen in the fragile X [Fra(X)] syndrome. In one family, a folate insensitive fragile site was associated with Robin sequence in the propositus. In a second family a fra(X) negative mother has two fra(X) positive sons (one mentally retarded and the other newborn). The third family presents very high expression of a folate sensitive site, unlinked to mental retardation, and was described previously by Voelckel et al. [1989]. The fragile sites in these or similar families recently described must be different from the one associated with the fra(X) syndrome. Their association with a clinical phenotype or with mental retardation is certainly not consistent, and may represent an ascertainment bias. However, the relatively high frequency with which they have been found among previously diagnosed fra(X) families suggests that, at least in some cases, the association with mental impairment may be significant. In two families reported up to now, a male with high expression of such variant fra(X) site failed to transmit it to his daughter, which may reflect an imprinting effect. Previously diagnosed families should be reinvestigated before direct DNA analysis is used for prenatal or carrier diagnosis of the fra(X) syndrome. 相似文献
18.
Progenitor egress from the bone marrow after allergen challenge: role of stromal cell-derived factor 1alpha and eotaxin 总被引:4,自引:0,他引:4
Dorman SC Babirad I Post J Watson RM Foley R Jones GL O'Byrne PM Sehmi R 《The Journal of allergy and clinical immunology》2005,115(3):501-507
BACKGROUND: CCR3 expression on CD34+ cells mediates migration to eotaxin in vitro. CXCR4 and stromal cell-derived factor (SDF)-1alpha are important for stem cell homing to hemopoietic compartments. OBJECTIVE: To study chemokine-mediated progenitor cell traffic in allergic inflammation. METHODS: Bone marrow (BM) aspirates were obtained at baseline from normal subjects; atopic subjects without asthma; and subjects with asthma before, 5 hours after, and 24 hours after allergen inhalation (dual and early responders). Changes in chemokine receptor expression and migration were assessed. RESULTS: Expression of CXCR4, but not CCR3, on BM CD34+ cells was greater in normal subjects compared with atopic subjects with asthma. Likewise, SDF-1alpha, but not eotaxin, stimulated a greater migrational response by BM CD34+ cells from normal subjects compared with subjects with asthma. For all subjects, a positive correlation was found between intensity of CXCR4 expression and magnitude of CD34+ cell response to SDF-1alpha. Allergen inhalation attenuated both intensity of CXCR4 expression and SDF-1alpha levels in marrow from dual compared with early responders 24 hours postallergen. In contrast, the intensity of CCR3 expression on BM CD34+ cells increased in dual compared with early responders at 24 hours postallergen. In addition, an increase in migrational responsiveness of BM CD34+ cells to eotaxin and a decrease to SDF-1alpha 24 hours postallergen was found in dual responder subjects with asthma. CONCLUSION: After allergen inhalation in subjects with asthma, a downregulation in CXCR4 intensity on BM CD34+ cells and a reduction in BM SDF-1alpha levels may reduce progenitor retention to marrow stroma promoting peripheral egress, possibly mediated by the CCR3/eotaxin axis. 相似文献
19.
Danielle M. Logue Laura Mahony Clare A. Corish David Tobin Ronan Doherty Grainne OHiggins Sharon M. Madigan 《Nutrients》2021,13(6)
Background: Low energy availability results in physiological adaptations which contribute to unfavourable health outcomes. Little information exists on perceptions of nutritional advice to eat more food to maintain health and enhance performance. The aim of this study was to explore athletes’ and coaches’ perceptions towards advice to athletes to eat larger than their current quantities of food and to explore how nutritionists could deliver this advice. Methods: Semi-structured interviews (~20 min in length) were conducted using online communication technology, audio-recorded, and transcribed verbatim. The interview explored perceptions of the nutritional advice provided, its role in health and performance, and the challenges to eating larger amounts of food. Data were analysed using NVIVO 1.2 using an inductive thematic approach. Results: Nine elite athletes (female = 6; males = 3) and nine high-performance coaches (female = 3; male = 6) completed the semi-structured interviews. Athletes reported improved training consistency, fewer injuries and illnesses, and improved resilience when consuming adequate energy and nutrients to meet their needs. Lack of time and meal preparation difficulties were the main challenges faced to fuelling. Conclusions: Although education about under-fuelling is important, motivating, enabling, and supporting athletes to change behaviour is pivotal to increasing athlete self-awareness and to make long-term nutritional changes. 相似文献
20.
Background: Hybrid, combined or mixed bariatric surgery is the combination of a degree of ‘malabsorption’ (as achieved by the intestinal bypass) with a ‘rrestriction’
(as achieved by gastric bypass or gastroplasty), thereby simultaneously reducing the absorption of fats in the small bowel
and decreasing the intake of food. Methods: A modification of the bilio-pancreatic diversion (BPD) with a duodenal switch
procedure, vertical lineal gastrectomy and preservation of the pylorus, has been used in 23 patients. The antropyloric pump
and 4 cm of the duodenum are left intact to preserve physiologic gastric emptying and to prevent anastomotic ulcer. The use
of staplers and continuous running sutures reduces surgical risks and operative time. Results: One patient, converted from
a vertical gastroplasty, had an intrathoracic esophageal perforation and died of multisystemic organ failure, a mortality
rate of 4.5%. One patient had a partial dehiscence of the laparotomy wound. Three patients developed subcutaneous seromas.
Mean weight losses during the first 4 months were 13, 11, 6 and 5 kg, with a loss of 70% of excess weight in patients approaching
1 year. No patient needs treatment for diarrhea. No serious secondary side-effects have been detected. Conclusion: This operation
appears to result in very satisfactory weight loss, improved quality of life, and a low incidence of complications. 相似文献