全文获取类型
收费全文 | 11549篇 |
免费 | 754篇 |
国内免费 | 85篇 |
专业分类
耳鼻咽喉 | 91篇 |
儿科学 | 260篇 |
妇产科学 | 305篇 |
基础医学 | 1933篇 |
口腔科学 | 188篇 |
临床医学 | 936篇 |
内科学 | 2526篇 |
皮肤病学 | 321篇 |
神经病学 | 1264篇 |
特种医学 | 420篇 |
外科学 | 1098篇 |
综合类 | 29篇 |
预防医学 | 841篇 |
眼科学 | 156篇 |
药学 | 1097篇 |
中国医学 | 43篇 |
肿瘤学 | 880篇 |
出版年
2024年 | 27篇 |
2023年 | 170篇 |
2022年 | 319篇 |
2021年 | 467篇 |
2020年 | 325篇 |
2019年 | 423篇 |
2018年 | 550篇 |
2017年 | 400篇 |
2016年 | 483篇 |
2015年 | 503篇 |
2014年 | 671篇 |
2013年 | 858篇 |
2012年 | 1213篇 |
2011年 | 1268篇 |
2010年 | 686篇 |
2009年 | 418篇 |
2008年 | 517篇 |
2007年 | 458篇 |
2006年 | 421篇 |
2005年 | 319篇 |
2004年 | 250篇 |
2003年 | 230篇 |
2002年 | 163篇 |
2001年 | 70篇 |
2000年 | 51篇 |
1999年 | 54篇 |
1998年 | 70篇 |
1997年 | 53篇 |
1996年 | 46篇 |
1995年 | 48篇 |
1994年 | 35篇 |
1993年 | 29篇 |
1992年 | 37篇 |
1991年 | 33篇 |
1990年 | 35篇 |
1989年 | 27篇 |
1988年 | 26篇 |
1986年 | 24篇 |
1985年 | 28篇 |
1984年 | 33篇 |
1983年 | 22篇 |
1982年 | 32篇 |
1981年 | 22篇 |
1980年 | 22篇 |
1979年 | 22篇 |
1977年 | 25篇 |
1976年 | 21篇 |
1975年 | 26篇 |
1973年 | 25篇 |
1967年 | 21篇 |
排序方式: 共有10000条查询结果,搜索用时 11 毫秒
991.
BACKGROUND: This study compared children and adolescents with epilepsy with their healthy peers on measures of social competence. METHODS: Children and adolescents with epilepsy (70 subjects aged 11-18 years; 47.1% girls) and their healthy peers in control group (95 subjects aged 11-18 years; 50.9% girls) were compared on measures of social competence from the Child Competence Checklist (part of Child Behavior Check List). The questionnaires were completed by the parents. All participants were of normal intelligence. RESULTS: The difference of means of total T scores for subscales of sociabilitiy and activities in the epilepsy group and in the control group were statistically significant (p<0.05). The results showed that 5.7% of children and adolescents with epilepsy were in the clinical range compared to 2.1% of subjects in control group. The girls with epilepsy demonstrated greater problems with social competence (45.8+/-8.27) than boys with epilepsy (48.1+/-8.27) and this difference was statistically significant (p<0.05). Multiple analysis of variance of T scores for social competence subscales related to neurobiological variables in the group of participants with epilepsy demonstrated a statistically significant association of reduced sociability with multiple generalized seizure types (F=4,405; d.f.=2; p<0.05). CONCLUSIONS: The study clearly shows that epilepsy is a limiting factor for social competence of children and adolescents. 相似文献
992.
Alessandro Serretti Chiara Fabbri Silvia Pellegrini Stefano Porcelli Pierluigi Politi Silvio Bellino Marco Menchetti Veronica Mariotti Cristina Demi Valentina Martinelli Marco Cappucciati Paola Bozzatello Elena Brignolo Paolo Brambilla Chi-Un Pae Matteo Balestrieri Diana De Ronchi 《Psychiatry investigation》2013,10(2):180-189
Objective
Gene variants within the serotonin pathway have been associated with major depressive disorder (MDD) treatment outcomes, however a possible different modulation on pharmacological or psychological treatments has never been investigated.Methods
One hundred sixty MDD patients were partially randomized to either inter-personal counseling (IPC) or antidepressants. The primary outcome was remission at week 8. Five serotonergic polymorphisms were investigated (COMT rs4680, HTR1A rs6295, HTR2A rs2224721, HTR2A rs7997012 and SLC6A4 rs421417).Results
IPC (n=43) and antidepressant (n=117) treated patients did not show any difference in remission rates at week 8 (corrected for baseline severity, age and center). None of the studied gene variants impacted on response and remission rates at week 8 neither in the IPC nor in the antidepressant group. An analysis of the whole sample showed a trend of association between rs7997012 AA genotype and a better treatment outcome.Conclusion
Our study confirms that IPC is an effective psychological intervention comparable to antidepressants in mild-moderate MDD. Polymorphisms related to the serotonin system did not exert a major effect on clinical outcomes in none of the treatment groups. 相似文献993.
In the neurosurgical approach to intracranial aneurysms which are often accompanied by arterial spasm and cortical ischaemia, monitoring procedures aim to obtain useful information on cerebral function. SEPs evoked by stimulation of the median nerve at the wrist and of the tibial nerve at the medial malleolus were registered in 45 patients with intracranial aneurysms during neurosurgical procedures. Our results show SEP abnormalities during different stages of neurosurgical procedures in 36 patients out of the monitored 45. Significant abnormalities of SEPs with respect to the control group were decrease of the amplitude of N 20-P 25 complex, lengthening of the absolute latency of the waves N 20- and P 25 and lengthening of the central conduction time (CCT) (N 13-N 20). The greatest SEP abnormalities were registered during the neurosurgical approach to aneurysm and during the clipping procedure. However, the changes were reversible in the majority of the patients. The aim of this paper was to focus on early detection of some cerebral function disturbances during the neurosurgical procedure as well as the prevention of possible brain damage. 相似文献
994.
Aida Salihagić Marija Mačković Hrvoje Banfić Ivan Sabolić 《Pflügers Archiv : European journal of physiology》1988,413(2):190-196
The effect of unilateral nephrectomy on Na+–H+ exchange in rat renal cortical brush-border membrane vesicles (BBMV) was studied by the method of acridine orange fluorescence quenching. The exchanger activity in BBMV from remnant kidney increased rapidly by 70–75% within first 30 min following uninephrectomy. Only a slight further increase was found in later stages of renal growth, i.e. 30 min to 7 days following uninephrectomy. The changes in antiporter activity were restricted toV
max, whereas theK
m for Na+ was similar in control and compensatory growing kidney. The increase of Na+–H+ exchange at 15 min was not affected by actinomycin D in vivo, whereas the increase at 48 h was completely abolished indicating that protein synthesis could be involved in the late, but not in the initial stimulation of renal Na+–H+ exchange. The late, but not the initial stimulations of Na+–H+ exchange were associated with elevated activities of cortical (Na++K+)-ATPase indicating that changes in antiporter activity precede those in the (Na++K+)-pump. The early stimulation of Na+–H+ exchange in BBMV in one kidney was induced also by the occlusion of blood flow through the contralateral kidney for 15 min, without removing it. Thirty min after the occlusion was removed and the reflow established, the Na+–H+ exchange in BBMV from the intact kidney decreased to the control values. The observed modulations in renal Na+–H+ exchanger may be regulated by phosphorylation-dephosphorylation events. In support, the concentration of a well known protein kinase C activator, 1,2-diacylglycerol, in the cortical tissue of the remnant kidney increased up to 100% within 5 min following unilateral nephrectomy and preceded the increase in Na+–H+ exchange. The early stimulation of Na+–H+ exchange may be a trigger in initiating the kidney growth. 相似文献
995.
Alexander Meyer Susanne Merkel Wolfgang Brückl Vera Schellerer Claus Schildberg Valentina Campean Werner Hohenberger Roland S. Croner 《European journal of cancer (Oxford, England : 1990)》2009,45(8):1466-1473
PurposeCyclin-dependent kinase 2 (cdc2) controls the G2–M checkpoint and, therefore, the entrance of cells into mitosis. It might play a crucial role during tumour progression in colon carcinomas (CCA). Thus, the prognostic value of cdc2 expression and connected markers relevant for proliferation and apoptosis has to be evaluated.Experimental designPunch biopsies from the tumour centre and the invasion front of 0.6 mm diameter from 392 CCA stage UICC II–IV were integrated in 14 recipient paraffin blocks. After immunohistochemical staining for cdc2, p53, caspase 3 and ki-67, a present (+) and absent (–) scoring was performed in the tissue arrays. The logrank test was used to compare distant metastasis and cancer-related survival. Multivariate Cox regression analysis was done to identify independent prognostic factors for parameters with significant influence on cancer-related survival (CRS) and distant metastasis (DM).ResultsThe pT-category (p = 0.007), nodal status (p < 0.001), extramural venous infiltration (p < 0.001) and lymphatic vessel invasion (p = 0.003) were identified as independent histological parameters for CRS. Univariate analysis relating to stage UICC II–IV CCA showed caspase 3 in the tumour centre (p = 0.047) to be a prognostic marker for CRS. In stage UICC II cdc2 (p = 0.041) and caspase 3 in the invasion front (p = 0.026) could be identified as independent prognostic factors for CRS and DM by multivariate analysis.ConclusionsCdc2 and caspase 3 could be identified as independent prognostic markers in stage UICC II CCA. They might be of value to select patients who should receive adjuvant treatment. 相似文献
996.
997.
Peter Kokol Marjan Mernik Jernej Završnik Kurt Kancler Ivan Malčić 《Journal of medical systems》1994,18(4):201-206
Computerized information systems, especially decision support systems, have become an increasingly important role in medical applications, particularly in those where important decision must be made effectively and reliably. But the possibility of using computers in medical decision making is limited by many difficulties, including the complexity of conventional computer languages, methodologies and tools. Thus a conceptual simple decision making model with the possibility of automating learning should be used. In this paper we introduce a cardiological knowledge-based system based on the decision tree approach supporting the mitral valve prolapse determination. Prolapse is defined as the displacement of a bodily part from its normal position. The term mitral valve prolaps (PMV), therefore, implies that the mitral leaflets are displaced relative to some structure, generally taken to be the mitral annulus. The implications of the PMV are the following: disturbed normal laminar blood flow, turbulence of the blood flow, injury of the chordae tendinae, the possibility of thrombus's composition, bacterial endocarditis, and finally hemodynamic changes defined as mitral insufficiency and mitral regurgitation. Uncertainty persists about how it should be diagnosed and about its clinical importance. It is our deep belief that the echocardiography enables properly trained experts armed with proper criteria to evaluate PMV almost 100%. But unfortunately, there are some problems concerned with the use of echocardiography. In that manner we have decided to start a research project aimed at finding new criteria and enabling the general practitioner to evaluate PMV using conventional methods and to select potential patients from the general population. To empower one to perform needed activities we have developed a computer tool called ROSE (computeRised prOlaps Syndrom dEtermination) based on algorithms of automatic learning. This tool supports the definition of new criteria and the selection of potential PMV-patients. 相似文献
998.
We investigated if continuous 1 μA direct current stimulation of the injured nerve, with the cathode electrode at the distal end of the nerve crush injury (cathode stimulation), accelerated the recovery of choline acetyltransferase (ChAT) and acetylcholinesterase (AChE) activity in transiently denervated extensor digitorum longus (EDL) and soleus (SOL) rat muscles. ChAT is a specific marker of cholinergic nerve terminals and may reflect axon ingrowth, and AChE reflects the re-establishment of neuromuscular junctions and recovery of muscle activity. Compared to sham operated animals, the cathode (CA) stimulated rats had a statistically significant larger ChAT activity in the EDL and SOL muscles on days 12 and 14 after nerve crush (P < 0.01, n = 6). The difference in ChAT activity between the groups decreased thereafter. Regarding recovery of muscle AChE, CA stimulation of the crushed sciatic nerve did not detectably accelerate the normalization of activity and pattern of AChE molecular forms in the EDL and SOL muscles. This means that the early rise in ChAT muscle activity in CA stimulated rats was not followed by an accelerated normalization of the neuromuscular transmission in the same group. It is more likely that the higher ChAT activity observed after cathode stimulation indicates a higher ChAT content in regenerating motor nerve endings, rather than a greater number of motor axons entering the muscles. It seems possible that cathode stimulation increased ChAT axonal transport, causing the early increase of ChAT content in the nerve endings. This raises the possibility that the axon transport and subsequent secretion of a trophic factor(s) from the nerve to the reinnervated muscle are enhanced as well, thus shortening the overall time of muscle force recovery in the absence of an appreciable acceleration of recovery of the neuromuscular transmission. 相似文献
999.
P. Trunečka O. Boillot D. Seehofer A. D. Pinna L. Fischer B.‐G. Ericzon R. I. Troisi U. Baccarani J. Ortiz de Urbina W. Wall 《American journal of transplantation》2010,10(10):2313-2323
The efficacy and safety of dual‐therapy regimens of twice‐daily tacrolimus (BID; Prograf) and once‐daily tacrolimus (QD; Advagraf) administered with steroids, without antibody induction, were compared in a multicenter, 1:1‐randomized, two‐arm, parallel‐group study in 475 primary liver transplant recipients. A double‐blind, double‐dummy 24‐week period was followed by an open extension to 12 months posttransplant. The primary endpoint, event rate of biopsy‐proven acute rejection (BPAR) at 24 weeks, was 33.7% for tacrolimus BID versus 36.3% for tacrolimus QD (Per‐protocol set; p = 0.512; treatment difference 2.6%, 95% confidence interval ?7.3%, 12.4%), falling within the predefined 15% noninferiority margin. At 12 months, BPAR episodes requiring treatment were similar for tacrolimus BID and QD (28.1% and 24.7%). Twelve‐month patient and graft survival was 90.8% and 85.6% for tacrolimus BID and 89.2% and 85.3% for tacrolimus QD. Adverse event (AE) profiles were similar for both tacrolimus BID and QD with comparable incidences of AEs and serious AEs. Tacrolimus QD was well tolerated with similar efficacy and safety profiles to tacrolimus BID. 相似文献
1000.
Roman Kotlín Zuzana Reicheltová Jiří Suttnar Peter Salaj Ingrid Hrachovinová Tomáš Riedel Martin Malý Milan Oravec Jan Kvasnička Jan Evangelista Dyr 《Journal of thrombosis and thrombolysis》2010,30(3):311-318
Hereditary dysfibrinogenemia is a rare disorder wherein an inherited abnormality in fibrinogen structure may result in defective
fibrin function and/or structure. Congenital hypofibrinogenemia is a rare autosomal bleeding disorder, either recessive or
dominant, characterized by a low fibrinogen plasma level. A 28-year-old asymptomatic woman (fibrinogen Rokycany) and a 54-year-old
man with thrombosis and pulmonary embolism (fibrinogen Znojmo) were investigated for a suspected fibrinogen mutation after
abnormal coagulation tests results were obtained. DNA sequencing showed the heterozygous point mutation Bβ Asn351Lys in fibrinogen
Rokycany and the heterozygous point mutation Bβ Arg237Ser in fibrinogen Znojmo, respectively. The kinetics of fibrinopeptide
release was found to be normal in both cases. Fibrinolysis was impaired in the Znojmo variant. The average fibril diameters
of Znojmo fibrin was slightly increased, but not differing significantly from normal; formed by less fibrils with abrupt fibril
terminations. Rheological studies revealed a softer clot. Rokycany fibrin was formed by significantly narrower fibrils than
normal fibrin; and the clot was denser than the control clot. Rheological studies revealed a stiffer clot. Impaired fibrinolysis
and abnormal clot morphology may be the cause of thrombotic episodes in the patient with Znojmo mutation. New cases of hypofibrinogenemia
and dysfibrinogenemia, found by routine coagulation testing, were genetically identified as a novel fibrinogen variants Bβ
Asn351Lys (fibrinogen Rokycany) and Bβ Arg237Ser (fibrinogen Znojmo), respectively. 相似文献