全文获取类型
收费全文 | 2967篇 |
免费 | 100篇 |
国内免费 | 11篇 |
专业分类
耳鼻咽喉 | 20篇 |
儿科学 | 61篇 |
妇产科学 | 90篇 |
基础医学 | 473篇 |
口腔科学 | 52篇 |
临床医学 | 159篇 |
内科学 | 405篇 |
皮肤病学 | 54篇 |
神经病学 | 316篇 |
特种医学 | 98篇 |
外科学 | 243篇 |
综合类 | 7篇 |
预防医学 | 560篇 |
眼科学 | 75篇 |
药学 | 334篇 |
中国医学 | 4篇 |
肿瘤学 | 127篇 |
出版年
2022年 | 25篇 |
2021年 | 30篇 |
2020年 | 28篇 |
2019年 | 39篇 |
2018年 | 57篇 |
2017年 | 35篇 |
2016年 | 43篇 |
2015年 | 45篇 |
2014年 | 58篇 |
2013年 | 82篇 |
2012年 | 166篇 |
2011年 | 157篇 |
2010年 | 80篇 |
2009年 | 57篇 |
2008年 | 135篇 |
2007年 | 127篇 |
2006年 | 151篇 |
2005年 | 135篇 |
2004年 | 135篇 |
2003年 | 124篇 |
2002年 | 134篇 |
2001年 | 81篇 |
2000年 | 81篇 |
1999年 | 72篇 |
1996年 | 17篇 |
1992年 | 42篇 |
1991年 | 41篇 |
1990年 | 41篇 |
1989年 | 43篇 |
1988年 | 42篇 |
1987年 | 46篇 |
1986年 | 56篇 |
1985年 | 49篇 |
1984年 | 28篇 |
1983年 | 26篇 |
1981年 | 18篇 |
1979年 | 34篇 |
1978年 | 22篇 |
1977年 | 16篇 |
1976年 | 16篇 |
1974年 | 24篇 |
1973年 | 29篇 |
1972年 | 42篇 |
1971年 | 33篇 |
1970年 | 23篇 |
1969年 | 34篇 |
1968年 | 42篇 |
1967年 | 32篇 |
1966年 | 30篇 |
1965年 | 19篇 |
排序方式: 共有3078条查询结果,搜索用时 0 毫秒
81.
Eszter Vojcek V. Anna Gyarmathy Rozsa Graf Anna M. Laszlo Laszlo Ablonczy Zsolt Prodan Istvan Seri 《Congenital heart disease》2022,17(4):447-461
Objective: Neonates with congenital heart disease (CHD) and perinatal stroke have high mortality and survivors are at risk for poor long-term neurodevelopmental outcome. The aim of this study was to assess the risk factors and outcome of neonates with both CHD and MRI-confirmed perinatal stroke (Study Group) and compare those to the risk factors and outcome of infants matched for CHD without stroke (Control-1) and of infants matched for MRI-confirmed stroke without CHD (Control-2). Methods: We conducted a population-based case-control study enrolling 28 term neonates with CHD and MRI-confirmed acute perinatal stroke born between 2007–2017 in the Central-Hungarian Region. Each of the control groups included 56 infants. The Bayley Scales of Infant Development-II, the Brunet-Lézine test and the Binet Intelligence scales-V were used for neurodevelopmental follow-up at a median age of 61 months. Results: Mortality was highest in the Study Group (25% compared to 5% and 2%, respectively, p = 0.001). Adverse neurodevelopmental outcome was prevalent in the Study (53%) and Control-2 Groups (52%, p = 0.03). Significantly different parameters among the three groups included Apgar scores, mode of delivery, gestational age at birth, cardiac interventions and twin pregnancy. In a multivariable regression analysis adjusted for clinically relevant parameters, patients in the Study Group had significantly higher odds for mortality compared to patients in the Control-1 Group (OR: 6.5 95% CI: 1.1–39.4). Conclusions: Neonates with perinatal stroke and CHD are at a higher risk for dying compared to neonates with CHD without stroke. In addition, the stroke-associated direct insult to the brain likely plays an important role in the development of neurodevelopmental morbidity in these patients. 相似文献
82.
83.
Chernyak A Kondo S Wade TK Meeks MD Alzari PM Fournier JM Taylor RK Kovác P Wade WF 《The Journal of infectious diseases》2002,185(7):950-962
Synthetic antigens that mimic the terminal hexasaccharide epitope of the O-specific polysaccharide of Vibrio cholerae O1, serotype Ogawa, were conjugated to bovine serum albumin (BSA). Conjugates with carbohydrate-to-carrier molar ratios of 15.5:1, 9.2:1, and 4.6:1 were tested for immunogenicity and efficacy in mice. The role of preimmunity to BSA and the use of adjuvant in the generation of the serologic response to the O-specific polysaccharide and protection against virulent V. cholerae was examined. Preimmunity to BSA did not affect the anti-Ogawa titers but seemed to enhance the protective capacity of antiserum. All 3 conjugates were immunogenic, but adjuvant was effective at inducing higher and earlier antibody responses. In tertiary serum samples, a correlation was found between vibriocidal activity and protection. The protective capacity of antiserum was evident in serum from mice immunized with all conjugates, but it was highest in the groups that received the conjugate with the lowest level of substitution. Further studies are required to increase understanding of the reason for differential protection. 相似文献
84.
Evidence for a lipochaperonin: Association of active proteinfolding GroESL oligomers with lipids can stabilize membranes under heat shock conditions 下载免费PDF全文
Zsolt Trk Ibolya Horvth Pierre Goloubinoff Eszter Kovcs Attila Glatz Gbor Balogh Lszl Vígh 《Proceedings of the National Academy of Sciences of the United States of America》1997,94(6):2192-2197
During heat shock, structural changes in proteins and membranes may lead to cell death. While GroE and other chaperone proteins are involved in the prevention of stress-induced protein aggregation and in the recovery of protein structures, a mechanism for short-term membrane stabilization during stress remains to be established. We found that GroEL chaperonin can associate with model lipid membranes. Binding was apparently governed by the composition and the physical state of the host bilayer. Limited proteolysis of GroEL oligomers by proteinase K, which removes selectively the conserved glycine- and methionine-rich C terminus, leaving the chaperonin oligomer intact, prevented chaperonin association with lipid membranes. GroEL increased the lipid order in the liquid crystalline state, yet remained functional as a protein-folding chaperonin. This suggests that, during stress, chaperonins can assume the functions of assisting the folding of both soluble and membrane-associated proteins while concomitantly stabilizing lipid membranes. 相似文献
85.
A closed curve is much more than an incomplete one: effect of closure in figure-ground segmentation. 总被引:10,自引:2,他引:10 下载免费PDF全文
I Kovács B Julesz 《Proceedings of the National Academy of Sciences of the United States of America》1993,90(16):7495-7497
Detection of fragmented closed contours against a cluttered background occurs much beyond the local coherence distance (maximal separation between segments) of nonclosed contours. This implies that the extent of interaction between locally connected detectors is boosted according to the global stimulus structure. We further show that detection of a target probe is facilitated when the probe is positioned inside a closed circle. To explain the striking contour segregation ability found here, and performance enhancement inside closed boundaries, we propose the existence of a synergetic process in early vision. 相似文献
86.
Gabriella Czifra Balázs Tóth Ildikó Kovács Tamás Bíró Zoltán Griger Sándor Baráth Tünde Tarr Margit Zeher Sándor Sipka 《Rheumatology international》2014,34(5):717-720
The objective of the study was to investigate the possibility whether the in vitro treatment with vitamin D3 can restore the impaired expression of protein kinase C (PKC) isoenzymes and IL-2 production in the lymphocytes of patients with systemic lupus erythematosus (SLE). Purified T lymphocytes from 14 patients with SLE and 13 healthy controls were cultured for 48 h in the presence and absence of 1 and 100 nM doses of vitamin D3. The expressions of various PKC isoenzymes were tested by Western blot analysis, and the amounts of various cytokines were detected by ELISA in the culture supernatants. Neither the low (1 nM) nor the high (100 nM) doses of vitamin D3 (1α,-25-dihydroxyvitamin) applied in vitro for 48 h were able to restore the decreased expression of PKC isoenzymes in the T cells of SLE patients. However, 100 nM of vitamin D3 significantly increased the release of IL-10, but suppressed the production of IL-2, IL-6, interferon γ and TNF α in the culture supernatants of both groups. As the low production of IL-2 is one of the main pathologic features of SLE, we recommend to avoid the use of high doses of vitamin D3 for treatment of lupus patients with vitamin D3 deficiency. 相似文献
87.
88.
Eszter Banki Krisztina Kovacs Daniel Nagy Tamas Juhasz Peter Degrell Katalin Csanaky Peter Kiss Gabor Jancso Gabor Toth Andrea Tamas Dora Reglodi 《Journal of molecular neuroscience : MN》2014,54(3):300-309
Diabetic nephropathy is the leading cause of end-stage renal failure and accounts for 30–40 % of patients entering renal transplant programmes. The nephroprotective effects of the neuropeptide pituitary adenylate cyclase-activating polypeptide (PACAP38) against diabetes have been shown previously, but the molecular mechanisms responsible for these effects remain unknown. In the present study, we showed that PACAP treatment counteracted the diabetes-induced increase in the level of the proapoptotic pp38MAPK and cleaved caspase-3 and also decreased the p60 subunit of NFκB. The examined antiapoptotic factors, including pAkt and pERK1/2, showed a slight increase in the diabetic kidneys, while PACAP treatment resulted in a notable elevation of these proteins. PCR and Western blot revealed the downregulation of fibrotic markers, like collagen IV and TGF-β1 in the kidney. PACAP treatment resulted in increased expression of the antioxidant glutathione. We conclude that the nephroprotective effect of PACAP in diabetes is, at least partly, due to its antiapoptotic, antifibrotic and antioxidative effect in addition to the previously described antiinflammatory effect. 相似文献
89.
Zsófia Bere Tihomir P Obrenovitch Gábor Kozák Ferenc Bari Eszter Farkas 《Journal of cerebral blood flow and metabolism》2014,34(10):1695-1705
Spreading depolarizations (SDs) occur in stroke, but the spatial association between SDs and the corresponding hemodynamic changes is incompletely understood. We applied multimodal imaging to visualize the focal area of selected SDs, and hemodynamic responses with SDs propagating over the ischemic cortex. The intracarotid infusion of polyethylene microspheres (d=45 to 53 μm) produced multifocal ischemia in anesthetized rats (n=7). Synchronous image sequences captured through a cranial window above the frontoparietal cortex revealed: Changes in membrane potential (voltage-sensitive (VS) dye method); cerebral blood flow (CBF; laser speckle contrast (LSC) imaging); and hemoglobin (Hb) deoxygenation (red intrinsic optical signal (IOS) at 620 to 640 nm). A total of 31 SD events were identified. The foci of five SDs were seen in the cranial window, originating where CBF was the lowest (56.9±9%), but without evident signs of infarcts. The hyperemic CBF responses to propagating SDs were coupled with three types of Hb saturation kinetics. More accentuated Hb desaturation was related to a larger decrease in CBF shortly after ischemia induction. Microsphere-induced embolization triggers SDs in the rat brain, relevant for small embolic infarcts in patients. The SD occurrence during the early phase of ischemia is not tightly associated with immediate infarct evolution. Various kinetics of Hb saturation may determine the metabolic consequences of individual SDs. 相似文献
90.
Kinga Karlinger Ádám Domonkos Tárnoki Dávid László Tárnoki Anne Polvi Anna-Elina Lehesjoki Andrea Kelemen László Szegedi Eszter Turányi Anita Kamondi Anna Szűcs 《Journal of neurology》2014,261(10):1911-1916
We present a clinical, neuro-radiological and genetic study on a family with members suffering from an autosomal dominantly inherited syndrome characterised by epilepsy, cerebral calcifications and cysts, bone abnormalities; progressive neuro-cognitive deterioration and paranasal sinusitis. This syndrome shares several features with leukoencephalopathy with calcifications and cysts also called Labrune syndrome and the condition of cerebroretinal microangiopathy with calcifications and cysts (CRMCC; Coats plus syndrome). Genetic studies in this family did not reveal mutations in the CTC1 gene defected in CRMCC. We interpret our results as those supporting recent findings that despite clinical similarities, late-onset Labrune and Coats plus syndrome might be distinct entities. This family may have Labrune syndrome or a yet unclassified entity; exploration of similar cases could help classifying this one, and related conditions. 相似文献