全文获取类型
收费全文 | 880篇 |
免费 | 71篇 |
国内免费 | 1篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 16篇 |
妇产科学 | 7篇 |
基础医学 | 144篇 |
口腔科学 | 7篇 |
临床医学 | 58篇 |
内科学 | 169篇 |
皮肤病学 | 11篇 |
神经病学 | 102篇 |
特种医学 | 33篇 |
外科学 | 163篇 |
综合类 | 5篇 |
预防医学 | 74篇 |
眼科学 | 13篇 |
药学 | 100篇 |
肿瘤学 | 48篇 |
出版年
2023年 | 11篇 |
2022年 | 9篇 |
2021年 | 19篇 |
2020年 | 10篇 |
2019年 | 16篇 |
2018年 | 15篇 |
2017年 | 16篇 |
2016年 | 13篇 |
2015年 | 17篇 |
2014年 | 26篇 |
2013年 | 34篇 |
2012年 | 45篇 |
2011年 | 44篇 |
2010年 | 27篇 |
2009年 | 35篇 |
2008年 | 30篇 |
2007年 | 44篇 |
2006年 | 34篇 |
2005年 | 52篇 |
2004年 | 36篇 |
2003年 | 25篇 |
2002年 | 39篇 |
2001年 | 28篇 |
2000年 | 29篇 |
1999年 | 32篇 |
1998年 | 10篇 |
1997年 | 9篇 |
1996年 | 12篇 |
1995年 | 6篇 |
1993年 | 9篇 |
1992年 | 17篇 |
1991年 | 13篇 |
1990年 | 13篇 |
1989年 | 18篇 |
1988年 | 17篇 |
1987年 | 13篇 |
1986年 | 14篇 |
1985年 | 21篇 |
1984年 | 5篇 |
1983年 | 9篇 |
1982年 | 6篇 |
1981年 | 5篇 |
1980年 | 4篇 |
1979年 | 9篇 |
1978年 | 5篇 |
1974年 | 5篇 |
1973年 | 4篇 |
1972年 | 4篇 |
1971年 | 4篇 |
1959年 | 4篇 |
排序方式: 共有952条查询结果,搜索用时 15 毫秒
11.
12.
13.
BACKGROUND: A randomized, double-blind, multi-center trial was started to compare the severity of extrapyramidal symptoms (EPS) during risperidone and haloperidol treatment in schizophrenic patients who had disturbing EPS during their previous neuroleptic treatment. Additional objectives of this trial were comparing the antipsychotic effectiveness of the two treatments and the use of antiparkinsonian medication. METHODS: Effects of flexible doses of risperidone and haloperidol were compared in 77 psychotic patients (83% with chronic schizophrenia) with disturbing neuroleptic-induced EPS (risperidone 40 patients, haloperidol 37). The trial was completed by 47 patients: 25 in the risperidone group (12 women, 13 men), and 22 in the haloperidol group (10 women, 12 men). RESULTS: An adequate antipsychotic effect was obtained in most patients by both treatments. The primary aim of this trial was comparing parkinsonism measured with the extrapyramidal syndrome rating scale (ESRS) during treatment with risperidone and haloperidol. Two primary parameters were selected: the change from baseline to the worst score during treatment of ESRS II (parkinsonism) and ESRS VI (clinical global impression of severity of parkinsonism). The CGI of severity of parkinsonism was better with risperidone (P=0.025), while the parkinsonism total score tended to be better with risperidone (P<0. 10). Before the double-blind treatment, 34 (of the 77) had used antiparkinson medication (risperidone 18, haloperidol 16). During the double-blind treatment phase, 21 patients had used antiparkinson medication (risperidone 11, haloperidol 10). The larger reduction of parkinsonism in the risperidone group was not due to a difference in the use of anti-parkinsonian medication. CONCLUSIONS: In this group of schizophrenic patients with disturbing EPS during previous neuroleptic treatment, a stronger reduction of parkinsonism was observed with risperidone than with haloperidol. 相似文献
14.
Jan Bredow Carolin Meyer Stavros Oikonomidis Constantin Kernich Nikolaus Kernich Christoph P. Hofstetter Vincent J. Heck Peer Eysel Tobias Prasse 《Orthopaedic Surgery》2022,14(8):1607
ObjectiveTo assess which radiological alignment parameters are associated with a satisfactory long‐term clinical outcome after performing lumbar spinal fusion for treating degenerative spondylolisthesis.MethodsThis single‐center prospective study assessed the relation between radiological alignment parameters measured on standing lateral lumbar spine radiographs and the patient‐reported outcome using four different questionnaires (COMI, EQ‐5D, ODI and VAS) as primary outcome measures (level of evidence: II). The following spinopelvic alignment parameters were used: gliding angle, sacral inclination, anterior displacement, sagittal rotation, lumbar lordosis, sacral slope, pelvic tilt and pelvic incidence. Furthermore, the length of stay and perioperative complications were documented. Only cases from 2013 to 2015 of low‐grade degenerative lumbar spondylolisthesis (Meyerding grades I and II) were considered. The patients underwent open posterior lumbar fusion surgery by pedicle screw instrumentation and cage insertion. The operative technique was either a posterior lumbar interbody fusion (PLIF) or a transforaminal lumbar interbody fusion (TLIF) performed by three different senior orthopedic surgeons. Exclusion criteria were spine fractures, minimally invasive techniques, underlying malignant diseases or acute infections, previous or multisegmental spine surgery as well as preoperative neurologic impairment. Of 89 initially contacted patients, 17 patients were included for data analysis (11 males, six females).ResultsThe data of 17 patients after mono‐ or bisegmental lumbar fusion surgery to treat low‐grade lumbar spondylolisthesis and with a follow‐up time of least 72 months were analyzed. The mean age was 66.7 ± 11.3 years. In terms of complications two dural tears and one intraoperative bleeding occurred. The average body mass index (BMI) was 27.6 ± 4.4 kg/m2 and the average inpatient length of stay was 12.9 ± 3.8 days (range: 8–21). The long‐term clinical outcome correlated significantly with the change of the pelvic tilt (r s = −0.515, P < 0.05) and the sagittal rotation (r s = −0.545, P < 0.05). The sacral slope was significantly associated with the sacral inclination (r s = 0.637, P < 0.01) and the pelvic incidence (r s = 0.500, P < 0.05). In addition, the pelvic incidence showed a significant correlation with the pelvic tilt (r s = 0.709, P < 0.01). The change of the different clinical scores over time also correlated significantly between the different questionnaires.ConclusionsThe surgical modification of the pelvic tilt and the sagittal rotation are the two radiological alignment parameters that can most accurately predict the long‐term clinical outcome after lumbar interbody fusion surgery. 相似文献
15.
Victoria Hoyle Madison T. Flasco Jiyeong Choi Elizabeth J. Cieniewicz Heather McLane Keith Perry Gerald Dangl Maher Al Rwahnih Michelle Heck Greg Loeb Marc F. Fuchs 《Viruses》2022,14(6)
Grapevine red blotch disease emerged within the past decade, disrupting North American vine stock production and vineyard profitability. Our understanding of how grapevine red blotch virus (GRBV), the causal agent of the disease, interacts with its Vitis hosts and insect vector, Spissistilus festinus, is limited. Here, we studied the capabilities of S. festinus to transmit GRBV from and to free-living vines, identified as first-generation hybrids of V. californica and V. vinifera ‘Sauvignon blanc’ (Vcal hybrids), and to and from V. vinifera ‘Cabernet franc’ (Vvin Cf) vines. The transmission rate of GRBV was high from infected Vcal hybrid vines to healthy Vcal hybrid vines (77%, 10 of 13) and from infected Vvin Cf vines to healthy Vcal hybrid vines (100%, 3 of 3). In contrast, the transmission rate of GRBV was low from infected Vcal hybrid vines to healthy Vvin Cf vines (15%, 2 of 13), and from infected Vvin Cf vines to healthy Vvin Cf vines (19%, 5 of 27). No association was found between transmission rates and GRBV titer in donor vines used in transmission assays, but the virus titer was higher in the recipient leaves of Vcal hybrid vines compared with recipient leaves of Vvin Cf vines. The transmission of GRBV from infected Vcal hybrid vines was also determined to be trans-stadial. Altogether, our findings revealed that free-living vines can be a source for the GRBV inoculum that is transmissible by S. festinus to other free-living vines and a wine grape cultivar, illustrating the interconnected roles of the two virus hosts in riparian areas and commercial vineyards, respectively, for virus spread. These new insights into red blotch disease epidemiology will inform the implementation of disease management strategies. 相似文献
16.
Carlos Guarner Bruce A. Runyon Sharon Young Mary Heck M.Yasin Sheikh 《Journal of hepatology》1997,26(6):1372-1378
Background/Aims: Translocation of indigenous bacterial from the gut lumen of cirrhotic animals to mesenteric lymph nodes appears to be an important step in the pathogenesis of spontaneous bacterial peritonitis. However, the sequence of events leading to translocation remains unclear. One of the most predictable risk factors for translocation is overgrowth of gut bacterial flora. The present study was designed to compare the intestinal aerobic bacterial flora of cecal stools at the time of sacrifice between cirrhotic and normal rats and to evaluate the role of intestinal aerobic bacterial overgrowth in bacterial translocation in cirrhotic rats.Methods: Thirty-five male Sprague-Dawley rats with carbon tetrachloride-induced cirrhosis and ascites and 10 normal rats were included in this study. Cirrhotic rats were sacrificed when ill and samples of ascitic fluid, mesenteric lymph nodes and cecal stool were taken for detecting quantitatively aerobic bacteria.Results: Total intestinal aerobic bacterial count in cecal stool at the time of sacrifice was significantly increased in cirrhotic rats with bacterial translocation with or without spontaneous bacterial peritonitis compared to cirrhotic rats without bacterial translocation (p<0.001 and p<0.001, respectively) and to normal rats (p<0.001 and p<0.001, respectively). Of the 42 species of bacteria translocating to the mesenteric lymph nodes, 41 (97.6%) were found in supranormal numbers in the stool at the time of sacrifice.Conclusions: Carbon tetrachloride-induced cirrhotic rats with bacterial translocation have increased total intestinal aerobic bacteria count, and intestinal bacterial overgrowth appears to play an important role in bacterial translocation in this experimental model of cirrhosis in rats. 相似文献
17.
18.
19.
20.
Piechnick R Ritter E Hildebrand PW Ernst OP Scheerer P Hofmann KP Heck M 《Proceedings of the National Academy of Sciences of the United States of America》2012,109(14):5247-5252
In the retinal binding pocket of rhodopsin, a Schiff base links the retinal ligand covalently to the Lys296 side chain. Light transforms the inverse agonist 11-cis-retinal into the agonist all-trans-retinal, leading to the active Meta II state. Crystal structures of Meta II and the active conformation of the opsin apoprotein revealed two openings of the 7-transmembrane (TM) bundle towards the hydrophobic core of the membrane, one between TM1/TM7 and one between TM5/TM6, respectively. Computational analysis revealed a putative ligand channel connecting the openings and traversing the binding pocket. Identified constrictions within the channel motivated this study of 35 rhodopsin mutants in which single amino acids lining the channel were replaced. 11-cis-retinal uptake and all-trans-retinal release were measured using UV/visible and fluorescence spectroscopy. Most mutations slow or accelerate both uptake and release, often with opposite effects. Mutations closer to the Lys296 active site show larger effects. The nucleophile hydroxylamine accelerates retinal release 80 times but the action profile of the mutants remains very similar. The data show that the mutations do not probe local channel permeability but rather affect global protein dynamics, with the focal point in the ligand pocket. We propose a model for retinal/receptor interaction in which the active receptor conformation sets the open state of the channel for 11-cis-retinal and all-trans-retinal, with positioning of the ligand at the active site as the kinetic bottleneck. Although other G protein-coupled receptors lack the covalent link to the protein, the access of ligands to their binding pocket may follow similar schemes. 相似文献