全文获取类型
收费全文 | 1256篇 |
免费 | 59篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 7篇 |
儿科学 | 29篇 |
妇产科学 | 24篇 |
基础医学 | 135篇 |
口腔科学 | 439篇 |
临床医学 | 64篇 |
内科学 | 204篇 |
皮肤病学 | 22篇 |
神经病学 | 118篇 |
特种医学 | 8篇 |
外科学 | 67篇 |
综合类 | 2篇 |
预防医学 | 49篇 |
眼科学 | 18篇 |
药学 | 62篇 |
中国医学 | 4篇 |
肿瘤学 | 70篇 |
出版年
2023年 | 7篇 |
2022年 | 30篇 |
2021年 | 37篇 |
2020年 | 33篇 |
2019年 | 138篇 |
2018年 | 156篇 |
2017年 | 215篇 |
2016年 | 25篇 |
2015年 | 42篇 |
2014年 | 45篇 |
2013年 | 59篇 |
2012年 | 93篇 |
2011年 | 91篇 |
2010年 | 48篇 |
2009年 | 30篇 |
2008年 | 64篇 |
2007年 | 42篇 |
2006年 | 34篇 |
2005年 | 47篇 |
2004年 | 28篇 |
2003年 | 30篇 |
2002年 | 22篇 |
2001年 | 2篇 |
1999年 | 2篇 |
1998年 | 1篇 |
1983年 | 1篇 |
排序方式: 共有1322条查询结果,搜索用时 15 毫秒
71.
Bender LE Spalton DJ Meacock W Jose R Boyce J 《Journal of cataract and refractive surgery》2003,29(3):526-531
PURPOSE: To investigate the value of early retroillumination imaging of the posterior capsule in predicting the eventual development of posterior capsule opacification (PCO). SETTING: Ophthalmology Department, St. Thomas' Hospital, and Department of Physics, King's College, London, United Kingdom. METHODS: All patients with retroillumination images of the posterior capsule taken 6 months and 2 years after uneventful phacoemulsification with in-the-bag intraocular lens (IOL) implantation were selected. The images were taken using the same hardware and analyzed with the same software to calculate the percentage area of the posterior capsule covered by lens epithelial cells. The percentage area of PCO with all IOL types 6 months postoperatively was correlated with that at 2 years. RESULTS: One hundred forty patients had analyzable images at 6 months and 2 years. Of these, 63 had a poly(methyl methacrylate) (PMMA) IOL (Pharmacia 812A or Storz P497UV), 33 an acrylic (Alcon AcrySof MA30 or SA30), 22 a silicone (Allergan SI-30), and 22 a hydrophilic acrylic (Bausch & Lomb Hydroview H60). The correlation of the percentage area of PCO at 6 months with that at 2 years resulted in an r value of 0.71 (P <.0001) in the entire group. The r value was 0.48 in the PMMA group and 0.86 in the foldable IOL group (P <.0001) (r value: AcrySof, 0.66; silicone, 0.82; Hydroview, 0.75). CONCLUSIONS: Retroillumination imaging of the posterior capsule 6 months after cataract surgery predicted the PCO outcome at 2 years in eyes with foldable IOLs. 相似文献
72.
Marina Friesen Stephanie ZieglerWaldkirch Milena Egenolf Paolo d'Errico Christina Helm Charlotte Mez Nikolaos Dokalis Daniel Erny Natalie Katzmarski Romina Coelho Desire Loreth Marco Prinz Melanie MeyerLuehmann 《Brain pathology (Zurich, Switzerland)》2022,32(3)
Several degenerative brain disorders such as Alzheimer''s disease (AD), Parkinson''s disease (PD) and Dementia with Lewy bodies (DLB) are characterized by the simultaneous appearance of amyloid‐β (Aβ) and α‐synuclein (α‐syn) pathologies and symptoms that are similar, making it difficult to differentiate between these diseases. Until now, an accurate diagnosis can only be made by postmortem analysis. Furthermore, the role of α‐syn in Aβ aggregation and the arising characteristic olfactory impairments observed during the progression of these diseases is still not well understood. Therefore, we assessed Aβ load in olfactory bulbs of APP‐transgenic mice expressing APP695 KM670/671NL and PSEN1 L166P under the control of the neuron‐specific Thy‐1 promoter (referred to here as APPPS1) and APPPS1 mice co‐expressing SNCA A30P (referred to here as APPPS1 × [A30P]aSYN). Furthermore, the olfactory capacity of these mice was evaluated in the buried food and olfactory avoidance test. Our results demonstrate an age‐dependent increase in Aβ load in the olfactory bulb of APP‐transgenic mice that go along with exacerbated olfactory performance. Our study provides clear evidence that the presence of α‐syn significantly diminished the endogenous and seed‐induced Aβ deposits and significantly ameliorated olfactory dysfunction in APPPS1 × [A30P]aSYN mice. 相似文献
73.
Alberto Cozzarin Gerardo Manuel Marambio Daniel Ernesto Ferreiro Maria Fernanda Gonda Lorena Romina Balletti Martin Hernán Medawar Juan Alberto Gagliardi Tomás Francisco Cianciulli 《Journal of Echocardiography》2018,16(3):139-146
Background
Transesophageal Doppler echocardiography has shown that significant stenosis can be detected based on the presence of aliasing with color Doppler in the stenotic area. The study aimed to assess the detection of angiographically significant coronary stenosis (ASCS) by analyzing the characteristics and velocities of resting coronary artery flow (RCF) using transthoracic coronary Doppler echocardiography (TCDE).Methods
TCDE was performed before diagnostic coronary angiography (CA). The following velocities were measured: peak systolic velocity (PSV), peak diastolic velocity (PDV), mean diastolic velocity (MDV), end-diastolic velocity (EDV), and distal to proximal velocity ratios.Results
Twenty-five patients were included, and CA revealed ASCS in 14 patients. With TCDE, the proximal and distal portions of the left anterior descending artery (LAD) could be measured in 84% of cases. Among 12 patients with ASCS in the distal left main coronary artery (LMCA) or proximal or mid LAD, proximal and distal flow could be measured in ten patients. Proximal diastolic velocities were higher in patients with ASCS in the LAD, and a distal MDV/proximal MDV ratio < 0.5 had a 60% sensitivity and a 92% specificity for the detection of ASCS (AUC 0.77, 95% CI 0.56–0.92). For the detection of ASCS limited to the LMCA and/or proximal LAD, the distal MDV/proximal MDV ratio had a sensitivity of 100% and a specificity of 89% (AUC 0.98, 95% CI 0.81–0.99).Conclusions
Resting TCDE can detect ASCS in the LAD, particularly at the proximal level, analyzing the ratio between distal and proximal flow velocities. These results could not be demonstrated in the RCA and CX arteries.74.
Antiangiogenic drugs for chemotherapy of bladder tumours 总被引:1,自引:0,他引:1
BACKGROUND: Bladder cancers have different angiogenic pathways distinguishing not only papillary from solid tumours, but even papillary superficial from papillary invasive ones, thus representing selective targets for antiangiogenic drugs. METHODS: The bacterial wall component tecogalan, inhibiting basic fibroblast growth factor (bFGF), the fumagillin derivative TNP-470, inhibiting vascular endothelial growth factor (VEGF), the distamycin A derivative PNU153429, and the tetracycline minocycline were administered to nude mice injected with the human bladder cancer cell lines 639V, causing bFGF-expressing papillary superficial tumours, or T24, causing VEGF-expressing papillary invasive tumours. RESULTS: Tecogalan had no effect even on 639V tumour growth, where bFGF was unaffected. TNP-470 only had an effect on T24 tumours, delaying tumour appearance and growth and lowering VEGF; these effects were augmented by adding minocycline. PNU153429 had no effect on 639V tumours, and a slight effect on T24 tumours. CONCLUSION: TNP-470 may represent a selective drug for the treatment of VEGF-expressing invasive papillary bladder tumours. 相似文献
75.
Stephanie Stein Lara Henze Tobias Poch Antonella Carambia Till Krech Max Preti Fenja Amrei Schuran Maria Reich Verena Keitel Romina Fiorotto Mario Strazzabosco Lutz Fischer Jun Li Luisa Marie Müller Jonas Wagner Nicola Gagliani Johannes Herkel Dorothee Schwinge Christoph Schramm 《Journal of hepatology》2021,74(4):919-930
76.
María Carolina Monti Romina Soledad Almirón Elena A. Bignante Oscar Ángel Ramírez 《Synapse (New York, N.Y.)》2010,64(1):39-46
Contextual cues linked to drug experience have been frequently associated to craving and relapse, with this phenomenon being described in human and experimental animals. Hippocampal synaptic plasticity has been related to learning, memory, and adaptive processes developed during chronic administration of drug abuse. In this study, we investigated if the environmental context associated with withdrawal experience was able to evoke the same behavioral alteration observed after chronic benzodiazepine administration. Furthermore, we studied the hippocampal synaptic plasticity and anatomical expression of Arc protein during withdrawal and the re‐exposure to the context associated with anxiety expression (characteristic sign of benzodiazepines withdrawal). It was demonstrated that re‐exposure evoked on days 15 and 25 after the first exposure the same behavior. An increased hippocampal synaptic plasticity, expressed as a lower threshold to induce long‐term potentiation on dentate gyrus, was observed in animals dependent on diazepam and during retrieval, in the same group, until day 15. This plastic change disappeared 25 days after the first exposure. An overexpression of Arc protein in the dorsal dentate gyrus and CA1 on the first day of withdrawal in the dependent animals was observed. Synapse 64:39–46, 2010. © 2009 Wiley‐Liss, Inc. 相似文献
77.
78.
79.
McKone E Hall A Pidcock M Palermo R Wilkinson RB Rivolta D Yovel G Davis JM O'Connor KB 《Cognitive neuropsychology》2011,28(2):109-146
The Cambridge Face Memory Test (CFMT, Duchaine & Nakayama, 2006) provides a validated format for testing novel face learning and has been a crucial instrument in the diagnosis of developmental prosopagnosia. Yet, some individuals who report everyday face recognition symptoms consistent with prosopagnosia, and are impaired on famous face tasks, perform normally on the CFMT. Possible reasons include measurement error, CFMT assessment of memory only at short delays, and a face set whose ethnicity is matched to only some Caucasian groups. We develop the "CFMT-Australian" (CFMT-Aus), which complements the CFMT-original by using ethnicity better matched to a different European subpopulation. Results confirm reliability (.88) and validity (convergent, divergent using cars, inversion effects). We show that face ethnicity within a race has subtle but clear effects on face processing even in normal participants (includes cross-over interaction for face ethnicity by perceiver country of origin in distinctiveness ratings). We show that CFMT-Aus clarifies diagnosis of prosopagnosia in 6 previously ambiguous cases. In 3 cases, this appears due to the better ethnic match to prosopagnosics. We also show that face memory at short (<3-min), 20-min, and 24-hr delays taps overlapping processes in normal participants. There is some suggestion that a form of prosopagnosia may exist that is long delay only and/or reflects failure to benefit from face repetition. 相似文献
80.
In this review we examine how attention is involved in detecting faces, recognizing facial identity and registering and discriminating between facial expressions of emotion. The first section examines whether these aspects of face perception are "automatic", in that they are especially rapid, non-conscious, mandatory and capacity-free. The second section discusses whether limited-capacity selective attention mechanisms are preferentially recruited by faces and facial expressions. Evidence from behavioral, neuropsychological, neuroimaging and psychophysiological studies from humans and single-unit recordings from primates is examined and the neural systems involved in processing faces, emotion and attention are highlighted. Avenues for further research are identified. 相似文献