全文获取类型
收费全文 | 1571篇 |
免费 | 71篇 |
国内免费 | 10篇 |
专业分类
耳鼻咽喉 | 7篇 |
儿科学 | 58篇 |
妇产科学 | 42篇 |
基础医学 | 109篇 |
口腔科学 | 45篇 |
临床医学 | 101篇 |
内科学 | 342篇 |
皮肤病学 | 47篇 |
神经病学 | 242篇 |
特种医学 | 191篇 |
外科学 | 206篇 |
综合类 | 15篇 |
预防医学 | 70篇 |
眼科学 | 7篇 |
药学 | 85篇 |
中国医学 | 1篇 |
肿瘤学 | 84篇 |
出版年
2023年 | 9篇 |
2022年 | 17篇 |
2021年 | 34篇 |
2020年 | 20篇 |
2019年 | 26篇 |
2018年 | 34篇 |
2017年 | 19篇 |
2016年 | 24篇 |
2015年 | 24篇 |
2014年 | 50篇 |
2013年 | 49篇 |
2012年 | 51篇 |
2011年 | 57篇 |
2010年 | 52篇 |
2009年 | 65篇 |
2008年 | 66篇 |
2007年 | 52篇 |
2006年 | 65篇 |
2005年 | 46篇 |
2004年 | 52篇 |
2003年 | 48篇 |
2002年 | 31篇 |
2001年 | 36篇 |
2000年 | 40篇 |
1999年 | 59篇 |
1998年 | 36篇 |
1997年 | 50篇 |
1996年 | 54篇 |
1995年 | 40篇 |
1994年 | 29篇 |
1993年 | 47篇 |
1992年 | 30篇 |
1991年 | 27篇 |
1990年 | 33篇 |
1989年 | 22篇 |
1988年 | 21篇 |
1987年 | 41篇 |
1986年 | 35篇 |
1985年 | 19篇 |
1984年 | 22篇 |
1983年 | 8篇 |
1982年 | 25篇 |
1981年 | 10篇 |
1980年 | 10篇 |
1979年 | 5篇 |
1977年 | 14篇 |
1976年 | 7篇 |
1975年 | 9篇 |
1969年 | 5篇 |
1967年 | 6篇 |
排序方式: 共有1652条查询结果,搜索用时 328 毫秒
101.
V D Pisani 《Journal of studies on alcohol》1977,38(5):972-985
Disadvantages of nonmedical detoxication centers are discussed. 相似文献
102.
LeRoy AJ; Williams HJ Jr; Bender CE; Segura JW; Patterson DE; Benson RC 《Radiology》1985,155(1):83-85
Two patients had colonic perforation as a result of percutaneous nephrostomy placement followed by track dilatation and renal calculus removal. We present the technical aspects of nephrostomy placement and stone removal, as well as the clinical diagnosis and management of these cases. Both patients recovered well with conservative therapy and required no surgical intervention. This report reviews the anatomic considerations for percutaneous nephrostomy in patients undergoing renal stone removal. 相似文献
103.
Acanthocytosis as a predisposing factor for non-ketotic hyperglycaemia induced chorea-ballism 总被引:1,自引:0,他引:1 下载免费PDF全文
Pisani A Diomedi M Rum A Cianciulli P Floris R Orlacchio A Bernardi G Calabresi P 《Journal of neurology, neurosurgery, and psychiatry》2005,76(12):1717-1719
BACKGROUND: Episodic non-ketotic hyperglycaemia in patients with diabetes may be responsible for a syndrome characterised by hemichorea-hemiballism associated with unique radiological features. OBJECTIVE: To investigate whether factors other than hyperglycaemia may be responsible for the neurological involvement. METHODS: Three patients who developed a persistent chorea-ballism syndrome triggered by a hyperglycaemic crisis were investigated. In these patients, the persistence of the involuntary movements required neuroleptic medication. RESULTS: T1 weighted magnetic resonance imaging revealed bilateral hyperintense lesions involving the striatum. Surprisingly, in these patients, the laboratory investigations revealed peripheral red blood cell acanthocytosis in a significant proportion of cells. CONCLUSION: Compared with the large population of patients with diabetes who do not show abnormal involuntary movements, unrecognised acanthocytosis in diabetes might render patients prone to develop hemichorea-hemiballism. 相似文献
104.
Merlini L Sabatelli P Columbaro M Bonifazi E Pisani V Massa R Novelli G 《Muscle & nerve》2005,31(6):764-767
A 49-year-old man had an 8-year history of persistent, isolated elevation of serum creatine kinase (hyper-CK-emia) without muscle symptoms, and no electromyographic evidence of myotonia; his muscle biopsy showed features reminiscent of myotonic dystrophy (DM), with morphometric findings consistent with those described in DM type 2 (DM2). Genetic studies excluded mutations in the DM type 1 (DM1) gene, but revealed a CCTG repeat expansion in the ZNF9 gene, which is associated with DM2. Our data suggest that in asymptomatic patients with persistent hyper-CK-emia, DM2 should be considered in the differential diagnosis. 相似文献
105.
Pervilhac C Stover J Pisani E Brown T Mayorga R Mugurungi O Shaukat M Fan L Ghys PD 《AIDS (London, England)》2005,19(Z2):S53-S58
HIV surveillance systems provide information that is crucial to our understanding of epidemic dynamics among different populations in different settings. Surveillance data are also used for advocacy, to inform policies and programming, and for monitoring. Multiple data sources may be used and will expand in the future as service statistics from prevention and treatment programmes become available. Important and new priorities in HIV surveillance data use at the national and local levels can build on past experience with surveillance reports, national estimates, advocacy materials, and communications to the media. A new framework, integrated analysis of data from expanded surveillance systems and other sources, is proposed to inform improved programming. The approach allows making effective programme choices, based on the analysis of biological and behavioral data and the coverage of interventions in an integrated fashion. The comparison of surveillance data with financial data provides added insights in the adequacy of the response. These findings and experiences set a new agenda for technical and structural directions to improve data use in countries. 相似文献
106.
Sabbatini M Pisani A Uccello F Serio V Serù R Paternò R Cianciaruso B Fuiano G Andreucci M 《Journal of the American Society of Nephrology : JASN》2004,15(4):901-909
Statins increase the production of nitric oxide (NO) and have beneficial effects on the course of acute renal failure (ARF) in young rats. The effects of a short-term treatment with atorvastatin (ATO) on ischemic ARF in old rats, characterized by a great susceptibility to ischemia, was tested. No difference was found in renal dynamics between young (Y, 3 mo old) and old (O, 18 mo old) rats in normal conditions (CON) or after ATO treatment (12 mg/kg/d for 14 d). Twenty-four hours after clamping of both renal arteries, a more pronounced decrease in GFR was observed in O rats versus Y rats after a greater renal vasoconstriction and hypoperfusion of aging animals. Pretreatment with ATO mitigated renal vasoconstriction in O rats and restored GFR values to Y rats. Nitrate excretion was enhanced in Y rats after ARF but was not further modified by ATO; in O rats, ARF did not increase nitrate excretion, which was raised after ATO treatment. This reflected the increase in endothelial NO synthase (eNOS)-mRNA expression and eNOS protein observed in old ATO-treated animals with ARF. ATO treatment had also a significant protective effect against the cell injury at tubular level in O, but not Y, rats. The Ras system was not influenced by ATO in O rats, whereas the activation of Rho proteins was partially inhibited by ATO. Low-dose treatment with ATO enhances NO availability in aging rats, improving renal dynamics and conferring a peculiar histologic protection at tubular level after ischemia. 相似文献
107.
Caccamo D Condello S Gorgone G Crisafulli G Belcastro V Gennaro S Striano P Pisani F Ientile R 《Neuromolecular medicine》2004,6(2-3):117-126
Hyperhomocysteinemia can result from decreased methylenetetrahydrofolate reductase (MTHFR) enzyme activity, owing to genetic
polymorphisms and/or inadequate folate intake. This study was aimed at investigating the prevalence of C677T and A1298C MTHFR
polymorphisms, and their impact on hyperhomocysteinemia in 95 epileptic patients and 98 controls. Double gradient-denaturing
gradient gel electrophoresis screening revealed that the frequency of T677 polymorphic allele was similar between cases and
controls (46.3% vs 42.3%), whereas that of C1298 allele was significantly higher in patients (30.5% vs 19.4%, p<0.05). Significant differences between the two groups were also found for the frequencies of genotypes AA1298 (46.3% in cases
vs 67.3% in controls, p<0.01) and AC1298 (46.3% in cases vs 26.6% in controls, p<0.01). Other genotype frequencies did not show any statistically significant differences. Haplotype frequencies significantly
differed between the two groups. The CT677/AC1298 diplotype was significantly more frequent in epileptic patients than in
controls (32.6% vs 18.4%, p<0.05). Patients treated with enzyme-inducing antiepileptic drugs, having this diplotype and concomitant low folate concentration
(i.e., <3.4 nmol/L), exhibited plasma homocysteine levels significantly higher than normal values (27.1±2.44 μmol/L, p<0.001). This increase, however, was lower than that observed in folate-deficient patients with diplotype TT677/AA1298 (41.3±3.41
μmol/L, p<0.001). Indeed, these two diplotypes could be regarded as risk factors for hyperhomocysteinemia. Conversely, we found that
the CC677/AA1298 diplotype was significantly more frequentin controls (p<0.01), suggesting a protective role. Our study suggests that both C677T and A1298C MTHFR polymorphisms should be examined
when assessing genetic risk factors of hyperhomocysteinemia in epilepsy. 相似文献
108.
Intracellular calcium increase in epileptiform activity: modulation by levetiracetam and lamotrigine 总被引:9,自引:0,他引:9
Pisani A Bonsi P Martella G De Persis C Costa C Pisani F Bernardi G Calabresi P 《Epilepsia》2004,45(7):719-728
PURPOSE: Alterations in neuronal calcium (Ca2+) homeostasis are believed to play an essential role in the generation and propagation of epileptiform events. Levetiracetam (LEV) and lamotrigine (LTG), novel antiepileptic drugs (AEDs), were tested on epileptiform events and the corresponding elevations in intracellular Ca2+ concentration ([Ca2+]i) recorded from rat neocortical slices. METHODS: Electrophysiological recordings were performed from single pyramidal neurons from a slice preparation. Spontaneous epileptiform events consisting of long-lasting, repetitive paroxysmal depolarization shifts (PDSs) and interictal spike activity were induced by reducing the magnesium concentration from the solution and by adding bicuculline and 4-aminopyridine. Simultaneously, microfluorimetric measurements of [Ca2+]i were performed. Optical imaging with Ca2+ indicators revealed a close correlation between Ca2+ transients and epileptiform events. RESULTS: Both LEV and LTG were able to reduce both amplitude and duration of PDSs, as well as the concomitant elevation in [Ca2+]i, in a dose-dependent fashion. Whole-cell patch-clamp recordings from isolated neocortical neurons revealed that LEV significantly reduced N-, and partially P/Q-type high-voltage-activated (HVA) Ca2+ currents, whereas sodium currents were unaffected. Interestingly, the inhibitory effects of LEV were mimicked and occluded by LTG or by a combination of omega-conotoxin GVIA and omega-agatoxin IVA, selective blockers of N- and P/Q-type HVA channels, respectively, suggesting a common site of action for these AEDs. CONCLUSIONS: These results demonstrate that large, transient elevations in neuronal [Ca2+]i correlate to epileptiform discharges. The antagonistic effects of LEV and LTG on [Ca2+]i overload might represent the basis for their anticonvulsant efficacy and could preserve neuronal viability. 相似文献
109.
110.
Amore M Balista C McCreadie RG Cimmino C Pisani F Bevilacqua G Ferrari G 《Biology of the neonate》2003,83(2):97-101
BACKGROUND: Human milk, unlike formula feeds, contains long-chain polyunsatured fatty acids, such as docosahexaenoic acid and arachidonic acid which are essential in the development of the central nervous system. If human milk is the optimal food for brain development, and if schizophrenia is a neurodevelopment disorder, might people who become schizophrenic in adult life be less likely to have been breast-fed? AIMS: To compare the incidence and length of breast-feeding in patients, siblings and normal controls and to examine the relationship between the duration of breast-feeding and age at onset of schizophrenia. METHOD: 113 schizophrenic patients were recruited, as were 140 siblings of the patients and 113 nonschizophrenic controls. The breast-feeding history of the patients, their siblings and controls was obtained through interviews with the mothers of the patients and controls. RESULTS: There were no significant differences between groups in the incidence of breast- feeding. The duration of breast-feeding was positively correlated with the age at onset of illness (r = +0.25, p < 0.02). CONCLUSION: Breast-feeding is no less common in those who develop schizophrenia in later life. However, breast milk might postpone the onset of the illness in schizophrenic patients. 相似文献