全文获取类型
收费全文 | 4350篇 |
免费 | 280篇 |
国内免费 | 10篇 |
专业分类
耳鼻咽喉 | 64篇 |
儿科学 | 156篇 |
妇产科学 | 91篇 |
基础医学 | 588篇 |
口腔科学 | 76篇 |
临床医学 | 418篇 |
内科学 | 882篇 |
皮肤病学 | 56篇 |
神经病学 | 588篇 |
特种医学 | 227篇 |
外科学 | 537篇 |
综合类 | 31篇 |
一般理论 | 3篇 |
预防医学 | 286篇 |
眼科学 | 52篇 |
药学 | 355篇 |
中国医学 | 6篇 |
肿瘤学 | 224篇 |
出版年
2023年 | 24篇 |
2022年 | 44篇 |
2021年 | 95篇 |
2020年 | 64篇 |
2019年 | 102篇 |
2018年 | 94篇 |
2017年 | 79篇 |
2016年 | 105篇 |
2015年 | 127篇 |
2014年 | 147篇 |
2013年 | 167篇 |
2012年 | 298篇 |
2011年 | 324篇 |
2010年 | 218篇 |
2009年 | 177篇 |
2008年 | 301篇 |
2007年 | 321篇 |
2006年 | 305篇 |
2005年 | 302篇 |
2004年 | 236篇 |
2003年 | 215篇 |
2002年 | 237篇 |
2001年 | 51篇 |
2000年 | 51篇 |
1999年 | 60篇 |
1998年 | 42篇 |
1997年 | 42篇 |
1996年 | 31篇 |
1995年 | 26篇 |
1994年 | 30篇 |
1993年 | 19篇 |
1992年 | 18篇 |
1991年 | 14篇 |
1990年 | 15篇 |
1989年 | 19篇 |
1988年 | 22篇 |
1987年 | 11篇 |
1986年 | 11篇 |
1985年 | 15篇 |
1984年 | 21篇 |
1983年 | 12篇 |
1982年 | 10篇 |
1981年 | 9篇 |
1979年 | 11篇 |
1977年 | 8篇 |
1976年 | 7篇 |
1974年 | 6篇 |
1973年 | 7篇 |
1971年 | 5篇 |
1966年 | 7篇 |
排序方式: 共有4640条查询结果,搜索用时 15 毫秒
101.
Die S3-Leitlinie „Peri- und Postmenopause – Diagnostik und Therapie“ beinhaltet Handlungsanweisungen und Empfehlungen für die Hormonersatztherapie (HRT) zur Behandlung klimakterischer Beschwerden, die von etwa 50 % der perimenopausalen Frauen und bei 30–80 % der postmenopausalen Frauen angegeben werden. Eine HRT mit Östrogenen (ET) oder Östrogenen und Gestagenen (EPT) wird als symptomatische Therapie zur Behandlung von klimakterischen Beschwerden mit klinisch relevanter Beeinträchtigung der Lebensqualität eingesetzt. Alternativ können auch Isoflavone, Cimicifuga-Präparate, Serotonin- bzw. Serotonin-Noradrenalin-Wiederaufnahmehemmer, Clonidin, Gabapentin oder kognitive Verhaltenstherapie angewendet werden. Im vorliegenden Artikel werden Effektivität und Sicherheit sowie Nebenwirkungen und systemische Wirkungen dieser unterschiedlichen Therapieformen entsprechend den Vorgaben der S3-Leitlinie „Peri- und Postmenopause – Diagnostik und Therapie“ dargestellt. 相似文献
102.
Die Gynäkologie - 相似文献
103.
Windler Eberhard Baum Erika Bhling Kai J. Taute Bettina-Maria Stute Petra Ortmann Olaf 《Gyn?kologische Endokrinologie》2020,18(1):16-19
Gynäkologische Endokrinologie - Auch die neue Version der AWMF-S3-Leitlinie „Peri- und Postmenopause – Diagnostik und Interventionen“ der Deutschen Gesellschaft für... 相似文献
104.
105.
John E. Kiat Taylor R. Hayes John M. Henderson Steven J. Luck 《The Journal of neuroscience》2022,42(1):97
Physically salient objects are thought to attract attention in natural scenes. However, research has shown that meaning maps, which capture the spatial distribution of semantically informative scene features, trump physical saliency in predicting the pattern of eye moments in natural scene viewing. Meaning maps even predict the fastest eye movements, suggesting that the brain extracts the spatial distribution of potentially meaningful scene regions very rapidly. To test this hypothesis, we applied representational similarity analysis to ERP data. The ERPs were obtained from human participants (N = 32, male and female) who viewed a series of 50 different natural scenes while performing a modified 1-back task. For each scene, we obtained a physical saliency map from a computational model and a meaning map from crowd-sourced ratings. We then used representational similarity analysis to assess the extent to which the representational geometry of physical saliency maps and meaning maps can predict the representational geometry of the neural response (the ERP scalp distribution) at each moment in time following scene onset. We found that a link between physical saliency and the ERPs emerged first (∼78 ms after stimulus onset), with a link to semantic informativeness emerging soon afterward (∼87 ms after stimulus onset). These findings are in line with previous evidence indicating that saliency is computed rapidly, while also indicating that information related to the spatial distribution of semantically informative scene elements is computed shortly thereafter, early enough to potentially exert an influence on eye movements.SIGNIFICANCE STATEMENT Attention may be attracted by physically salient objects, such as flashing lights, but humans must also be able to direct their attention to meaningful parts of scenes. Understanding how we direct attention to meaningful scene regions will be important for developing treatments for disorders of attention and for designing roadways, cockpits, and computer user interfaces. Information about saliency appears to be extracted rapidly by the brain, but little is known about the mechanisms that determine the locations of meaningful information. To address this gap, we showed people photographs of real-world scenes and measured brain activity. We found that information related to the locations of meaningful scene elements was extracted rapidly, shortly after the emergence of saliency-related information. 相似文献
106.
Andreas Tzschach Ute Grasshoff Stefanie Beck-Woedl Claudia Dufke Claudia Bauer Martin Kehrer Christina Evers Ute Moog Barbara Oehl-Jaschkowitz Nataliya Di Donato Robert Maiwald Christine Jung Alma Kuechler Solveig Schulz Peter Meinecke Stephanie Spranger Jürgen Kohlhase J?rg Seidel Silke Reif Manuela Rieger Angelika Riess Marc Sturm Julia Bickmann Christopher Schroeder Andreas Dufke Olaf Riess Peter Bauer 《European journal of human genetics : EJHG》2015,23(11):1513-1518
X-linked intellectual disability (XLID) is a genetically heterogeneous disorder with more than 100 genes known to date. Most genes are responsible for a small proportion of patients only, which has hitherto hampered the systematic screening of large patient cohorts. We performed targeted enrichment and next-generation sequencing of 107 XLID genes in a cohort of 150 male patients. Hundred patients had sporadic intellectual disability, and 50 patients had a family history suggestive of XLID. We also analysed a sporadic female patient with severe ID and epilepsy because she had strongly skewed X-inactivation. Target enrichment and high parallel sequencing allowed a diagnostic coverage of >10 reads for ~96% of all coding bases of the XLID genes at a mean coverage of 124 reads. We found 18 pathogenic variants in 13 XLID genes (AP1S2, ATRX, CUL4B, DLG3, IQSEC2, KDM5C, MED12, OPHN1, SLC9A6, SMC1A, UBE2A, UPF3B and ZDHHC9) among the 150 male patients. Thirteen pathogenic variants were present in the group of 50 familial patients (26%), and 5 pathogenic variants among the 100 sporadic patients (5%). Systematic gene dosage analysis for low coverage exons detected one pathogenic hemizygous deletion. An IQSEC2 nonsense variant was detected in the female ID patient, providing further evidence for a role of this gene in encephalopathy in females. Skewed X-inactivation was more frequently observed in mothers with pathogenic variants compared with those without known X-linked defects. The mutation rate in the cohort of sporadic patients corroborates previous estimates of 5–10% for X-chromosomal defects in male ID patients. 相似文献
107.
Akihiro Takamiya Annemiek Dols Louise Emsell Christopher Abbott Antoine Yrondi Carles Soriano Mas Martin Balslev Jorgensen Pia Nordanskog Didi Rhebergen Eric van Exel Mardien L Oudega Filip Bouckaert Mathieu Vandenbulcke Pascal Sienaert Patrice Pran Marta Cano Narcis Cardoner Anders Jorgensen Olaf B Paulson Paul Hamilton Robin Kampe Willem Bruin Hauke Bartsch Olga Therese Ousdal Ute Kessler Guido van Wingen Leif Oltedal Taishiro Kishimoto 《Schizophrenia bulletin》2022,48(2):514
Psychotic major depression (PMD) is hypothesized to be a distinct clinical entity from nonpsychotic major depression (NPMD). However, neurobiological evidence supporting this notion is scarce. The aim of this study is to identify gray matter volume (GMV) differences between PMD and NPMD and their longitudinal change following electroconvulsive therapy (ECT). Structural magnetic resonance imaging (MRI) data from 8 independent sites in the Global ECT-MRI Research Collaboration (GEMRIC) database (n = 108; 56 PMD and 52 NPMD; mean age 71.7 in PMD and 70.2 in NPMD) were analyzed. All participants underwent MRI before and after ECT. First, cross-sectional whole-brain voxel-wise GMV comparisons between PMD and NPMD were conducted at both time points. Second, in a flexible factorial model, a main effect of time and a group-by-time interaction were examined to identify longitudinal effects of ECT on GMV and longitudinal differential effects of ECT between PMD and NPMD, respectively. Compared with NPMD, PMD showed lower GMV in the prefrontal, temporal and parietal cortex before ECT; PMD showed lower GMV in the medial prefrontal cortex (MPFC) after ECT. Although there was a significant main effect of time on GMV in several brain regions in both PMD and NPMD, there was no significant group-by-time interaction. Lower GMV in the MPFC was consistently identified in PMD, suggesting this may be a trait-like neural substrate of PMD. Longitudinal effect of ECT on GMV may not explain superior ECT response in PMD, and further investigation is needed. 相似文献
108.
OBJECTIVE. The aim of this study was to prospectively assess the results of laparoscopic cholecystectomy in patients with acute inflammation of the gallbladder. SUMMARY BACKGROUND DATA. Laparoscopic cholecystectomy has become the standard treatment for symptomatic gallbladder disease. Its role in the surgical treatment of acute cholecystitis has not been defined, although a number of recent reports suggest that there should be few contraindications to an initial laparoscopic approach. METHODS. All patients presenting with symptomatic cholelithiasis from October 1990 until June 1992 were evaluated at laparoscopy with intention of proceeding to a laparoscopic cholecystectomy. The gross appearance of the gallbladder was categorized as acute inflammation, chronic inflammation, or no inflammation. Ninety-eight (23.4%) of 418 patients had acute inflammation of the gallbladder: 55 were edematous, 10 were gangrenous, 15 had a mucocele, and 18 had an empyema. RESULTS. The authors assessed outcome in these patients. The frequency of conversion to an open operation was 33.7% for acute inflammation, 21.7% for chronic inflammation (p < 0.05), and 4% for no inflammation (p < 0.001). The conversion rate was highest for empyema (83.3%) and gangrenous cholecystitis (50%), while the conversion rate for edematous cholecystitis was 21.8% and for acute inflammation with a mucocele it was 7%. The median operation time for successful laparoscopic cholecystectomy for acute inflammation was 105 minutes, which was longer than that with no inflammation (90 minutes). However, the incidence of complications was not different from that for chronic or no inflammation. The median postoperative stay for patients with acute gallbladder inflammation was 2 days for successful laparoscopic cholecystectomy and 7 days for patients converted to an open operation. CONCLUSIONS. Laparoscopic cholecystectomy for acute inflammation of the gallbladder is safe and is associated with a significantly shorter postoperative stay compared to open surgery. A greater number of patients required conversion to open operation compared to those with no obvious inflammation. Conversion to open operation was most frequent for empyema and gangrenous cholecystitis, suggesting that once this diagnosis is made, excessive time should not be spent in laparoscopic trial dissection before converting to an open operation. 相似文献
109.
Sydykova D Stahl R Dietrich O Ewers M Reiser MF Schoenberg SO Möller HJ Hampel H Teipel SJ 《Cerebral cortex (New York, N.Y. : 1991)》2007,17(10):2276-2282
Regional cortical atrophy in Alzheimer's disease (AD) most likely reflects the loss of cortical neurons. Several diffusion tensor imaging studies reported reduced fractional anisotropy (FA) in the corpus callosum in AD. The aim of this study was to investigate the association between reduced FA in the corpus callosum and gray matter atrophy in AD. Thirteen patients with AD with a mean (+/-standard deviation) age of 68.3 years (+/-11.5) and mean Mini Mental State Examination (MMSE) score of 21.8 (+/-4.8) were recruited. There were 13 control subjects with a mean age of 66.7 years (+/-6.4) and MMSE of 29.1 (+/-0.7). We used voxel-based morphometry of gray matter maps and region of interest-based analysis of FA in the corpus callosum. FA values of the anterior corpus callosum in AD patients were significantly correlated with gray matter volume in the prefrontal cortex and left parietal lobes. FA values of the posterior corpus callosum were significantly correlated with gray matter volume in the bilateral frontal, temporal, right parietal, and occipital lobes. In control subjects, no correlations were detected. Our findings suggest that decline of FA in the corpus callosum may be related to neuronal degeneration in corresponding cortical areas. 相似文献