全文获取类型
收费全文 | 9029篇 |
免费 | 550篇 |
国内免费 | 23篇 |
专业分类
耳鼻咽喉 | 36篇 |
儿科学 | 419篇 |
妇产科学 | 339篇 |
基础医学 | 978篇 |
口腔科学 | 87篇 |
临床医学 | 2006篇 |
内科学 | 1393篇 |
皮肤病学 | 123篇 |
神经病学 | 620篇 |
特种医学 | 319篇 |
外科学 | 774篇 |
综合类 | 86篇 |
一般理论 | 28篇 |
预防医学 | 1321篇 |
眼科学 | 155篇 |
药学 | 464篇 |
中国医学 | 9篇 |
肿瘤学 | 445篇 |
出版年
2024年 | 3篇 |
2023年 | 49篇 |
2022年 | 74篇 |
2021年 | 150篇 |
2020年 | 138篇 |
2019年 | 212篇 |
2018年 | 231篇 |
2017年 | 178篇 |
2016年 | 205篇 |
2015年 | 203篇 |
2014年 | 289篇 |
2013年 | 513篇 |
2012年 | 644篇 |
2011年 | 784篇 |
2010年 | 333篇 |
2009年 | 339篇 |
2008年 | 708篇 |
2007年 | 610篇 |
2006年 | 602篇 |
2005年 | 631篇 |
2004年 | 640篇 |
2003年 | 591篇 |
2002年 | 546篇 |
2001年 | 58篇 |
2000年 | 41篇 |
1999年 | 65篇 |
1998年 | 102篇 |
1997年 | 93篇 |
1996年 | 72篇 |
1995年 | 62篇 |
1994年 | 50篇 |
1993年 | 47篇 |
1992年 | 37篇 |
1991年 | 23篇 |
1990年 | 37篇 |
1989年 | 24篇 |
1988年 | 28篇 |
1987年 | 17篇 |
1986年 | 17篇 |
1985年 | 19篇 |
1984年 | 22篇 |
1983年 | 20篇 |
1982年 | 31篇 |
1981年 | 23篇 |
1980年 | 13篇 |
1979年 | 5篇 |
1978年 | 6篇 |
1977年 | 7篇 |
1976年 | 3篇 |
1975年 | 3篇 |
排序方式: 共有9602条查询结果,搜索用时 0 毫秒
21.
Ali Samii Debra D Dahlen Alexander M Spence Nicole C Maronian Eric E Kraus Vanda A Lennon 《Movement disorders》2003,18(12):1556-1558
The paraneoplastic autoantibody, collapsin response-mediator protein (CRMP)-5 immunoglobulin G (IgG), is specific for neuronal cytoplasmic CRMP-5, and is usually associated with small-cell lung carcinoma or thymoma. We report on details of a movement disorder that followed anti-B-cell therapy in a patient with lymphoma, and was accompanied by CRMP-5 IgG. 相似文献
22.
23.
Laparoscopic (vs. Open) Live Donor Nephrectomy: A UNOS Database Analysis of Early Graft Function and Survival 总被引:8,自引:0,他引:8
Christoph Troppmann Debra B. Ormond Richard V. Perez 《American journal of transplantation》2003,3(10):1295-1301
The impact of laparoscopic (lap) live donor nephrectomy on early graft function and survival remains controversial. We compared 2734 kidney transplants (tx) from lap donors and 2576 tx from open donors reported to the U.S. United Network for Organ Sharing from 11/1999 to 12/2000. Early function quality (>40 mL urine and/or serum creatinine [creat] decline >25% during the first 24 h post-tx) and delayed function incidence were similar for both groups. Significantly more lap (vs. open) txs, however, had discharge creats greater than 1.4 mg/dL (49.2% vs. 44.9%, p = 0.002) and 2.0 mg/dL (21.8% vs. 19.5%, p = 0.04). But all later creats, early and late rejection, as well as graft survival at 1 year (94.4%, lap tx vs. 94.1%, open tx) were similar for lap and open recipients. Our data suggests that lap nephrectomy is associated with slower early graft function. Rejection rates and short-term graft survival, however, were similar for lap and open graft recipients. Further prospective studies with longer follow up are necessary to assess the potential impact of the laparoscopic procurement mode on early graft function and long-term outcome. 相似文献
24.
Sylvie Naar-King Kathryn Wright Jeffrey T Parsons Maureen Frey Thomas Templin Phebe Lam Debra Murphy 《AIDS education and prevention》2006,18(1):1-11
This study piloted a brief individual motivational intervention targeting multiple health risk behaviors in HIV-positive youth aged 16-25. Interviews about sexual behavior and substance use and viral load testing were obtained from 51 HIV-positive youth at baseline and post intervention. Youth were randomized to receive a four-session motivational enhancement intervention (N = 25) or to a wait-list control (N = 26). Of the eligible youth approached, 88% agreed to participate, and 80% percent of participants completed at least three of four sessions. The treatment group showed significantly greater reductions in unprotected sex acts and in viral load compared with controls. Although change scores for substance use were not significantly different between the two groups, paired t tests demonstrated that reductions in alcohol use and marijuana use were significant for the treatment group at the trend level. There were no significant differences in substance use from baseline to posttest for the control group. Findings demonstrate the potential of a brief motivational enhancement intervention to improve health risk behaviors in HIV-positive youth. Larger randomized clinical trials are warranted. Resources required for retention should not be underestimated. 相似文献
25.
Debra Siela 《Rehabilitation nursing》2003,28(6):197-204
This correlational and comparative study explored whether self-reports of self-efficacy and dyspnea perceptions predict the perceived level of functional performance in adults who have chronic obstructive pulmonary disease (COPD). The convenience sample included 97 Caucasian men (52) and women (45). Participants had to have a forced expiratory volume in 1 second (FEV1) of less than 70% predicted, and a FEV1/forced vital capacity (FVC) of less than 70%. Participants were recruited from pulmonary function laboratories and from better breather support groups in a Midwestern state. Three standardized, self-report instruments, COPD Self-Efficacy Scale (CSES), the Pulmonary Functional Status and Dyspnea Questionnaire (PFSDQ), and Functional Performance Inventory (FPI) were used to measure the participants' self-report of their perceptions of self-efficacy, dyspnea, and functional performance. Dyspnea predicted 38.1% of the variance in functional performance, with self-efficacy contributing an additional 6.5% to the variance in the total sample. Self-efficacy predicted 36.5% of the variance in functional performance in men, with dyspnea contributing an additional 7.2% to the variance. However, in women, only dyspnea was a significant predictor of functional performance, at 48.5% when both dyspnea and self-efficacy were entered as independent variables. To improve patients' perceptions of functional performance, nurses can use methods such as breathing techniques and upper- and lower-body exercises that increase optimal management of dyspnea. Nurses may increase the self-efficacy of managing dyspnea by helping patients master breathing techniques and exercise through coaching and providing vicarious experiences through patient support groups or pulmonary rehabilitation programs. 相似文献
26.
BACKGROUND: As costs related to mechanical ventilation increase, clear indicators of patients' readiness to be weaned are needed. Research has not yet yielded a consensus on physiological variables that are consistent correlates of weaning outcomes. Subjective perceptions rarely have been examined for their contribution to successful weaning. OBJECTIVE: To explore the subjective perceptions of dyspnea, fatigue, and self-efficacy and selected physiological variables in patients being weaned from mechanical ventilation. METHODS: Data were collected prospectively on 68 patients being weaned from mechanical ventilation. Subjective perceptions were measured by using 3 visual analog scales; physiological variables were measured by using the Burns Weaning Assessment Program and a patient profile. Weaning outcomes were recorded 24 hours after data collection. RESULTS: Participants were primarily white women and required mechanical ventilation for a mean of less than 4 days. Participants reported mild dyspnea, moderate fatigue, and high weaning self-efficacy. High PaO2, low PaCO2, stable hemodynamic status, adequate cough and swallow reflexes, no metabolic changes, and no abdominal problems were associated with complete weaning (P = .05). Subjective perceptions were associated with physiological variables but not with weaning outcomes. CONCLUSIONS: Multidimensional assessment of both primary and secondary indicators of readiness to be weaned is necessary for timely, efficient weaning from mechanical ventilation. Primary assessments include physiological variables related to gas exchange, hemodynamic status, diaphragmatic expansion, and airway clearance. Secondary assessments include perceptions related to key physiological variables. Additional research is needed to determine the predictive value of physiological variables and perceptions of dyspnea, fatigue, and self-efficacy. 相似文献
27.
Infections with mouse coronavirus (also known as mouse hepatitis virus, MHV) are common and prompt concern because the adverse research effects of infection have been well documented. The animal facility we describe had contained an enzootic infection of mouse coronavirus for more than a decade. Eradication of the virus had been tried with limited success in the past. With an increase in the populations of immune-compromised and transgenic animals elsewhere in the facility, eradication of the virus became a high priority. The affected animals were in multiple breeding colonies comprising more than 4000 mice representing more than 50 site-specific strains, lines, and sublines. A task force designed to ensure representation of all interested parties developed a multi-phase approach which included (a) culling of nonessential animals, (b) cessation of breeding, (c) testing and culling of individual animals, and (d) cross-fostering to clean dams. To date, all of the strains, lines, and sublines manipulated through this multi-phase eradication approach continue to test negative for mouse coronavirus. This multi-phase approach may be useful for other institutions attempting to eradicate mouse coronavirus. 相似文献
28.
Debra L Ellies Beth Viviano John McCarthy Jean-Philippe Rey Nobue Itasaki Scott Saunders Robb Krumlauf 《Journal of bone and mineral research》2006,21(11):1738-1749
We compared and contrasted the mechanism of action for the cysteine knot protein subfamily, Wise and Sost (Sclerostin). Our data suggest that functional interactions between Sost or Wise and LRP5/LRP6 have the potential to regulate bone deposition by modulating the Wnt pathway. INTRODUCTION: The human disease sclerosteosis exhibits an increase in bone mass thought to be caused by hyperactive osteoblasts. Sclerostin, SOST, the gene affected in this disease, has been postulated to exert its activity by functioning as a BMP antagonist. However, recent evidence indicates that SOST is highly related to Wise, which can also modulate the Wnt pathway by binding to LRP5 and LRP6. MATERIALS AND METHODS: For this study, we used cell culture to test the BMP and Wnt activity function of both Wise and Sost. In addition, we used Xenopus in vivo Wnt assays along with Xenopus in vitro Wnt assays to support our cell culture results. Epitope tagged cell supernatants containing either Sost or soluble mutant or wildtype LRP5/LRP6 were used for immunoprecipitation. Sost immunoprecipitation results were confirmed in vivo using cell culture. Finally, to support our in vitro data, we co-localized Sost, Wise, LRP5, and LRP6 in mouse long bone sections. Results: In this study, we report in vitro and in vivo evidence to show that Sost physically interacts with Lrp5 and Lrp6 and inhibits the canonical Wnt signaling pathway. Furthermore, using in vitro and in vivo assays, we showed that a variant of LRP5 (LRP5(G171V)) known to cause the human high bone mass (HBM) trait and a homologous change in LRP6 (LRP6(G158V)) abolished protein interactions with Sost. We used variants of Sost amino acids to further identify the contact points between Sost and LRP6. In Xenopus and mammalian cell culture assays, we showed that SOST is able to attenuate Wnt signaling and that this attenuation can be rescued by the addition of alpha-Sost antibodies or by the introduction of single amino acid substitution that alter its binding to LRP6. Sost differs from Wise in that it is unable to stimulate Wnt signaling. Using immunohistochemistry, we found that Sost and Wise are co-localized to osteoblasts, along with LRP5 and LRP6. CONCLUSIONS: Our data suggest that functional interactions between Sost or Wise and LRPs have the potential to regulate bone deposition by modulating Wnt signaling. 相似文献
29.
Limitations of CT during PET/CT. 总被引:1,自引:0,他引:1
Marc J Gollub Richard Hong Debra M Sarasohn Tim Akhurst 《Journal of nuclear medicine》2007,48(10):1583-1591
Our aim was to determine the diagnostic limitations of low-dose, unenhanced CT scans performed for anatomic reference and attenuation correction during PET/CT. METHODS: The Radiology Information System at our oncologic hospital was queried during the 9-mo period from July 2002 to April 2003 for patients with PET/CT scans and diagnostic enhanced CT within 2 wk of each other. One radiologist interpreted the CT portion of the PET/CT (CT(p)) unaware of the PET results and the associated enhanced diagnostic CT (CT(d)). A medical student compared this interpretation with the official report of the CT(d) and listed all discrepancies between reports. A separate radiologist compared CT(p) and CT(d) images and classified true discrepant findings as due to lack of intravenous contrast, arm-position artifact, lack of enteric contrast, low milliamperage (mA), and quality of lung images. RESULTS: Among 100 patients, the most common malignancies were lymphoma (n = 37), cancer of the colorectum (n = 31), and esophageal cancer (n = 15). Among 194 true discrepancies in which findings were missed at CT(p), causes were as follows: (a) lack of intravenous contrast (128/194, 66%), (b) arm-down artifact (17/194, 9%), (c) quality of lung images (26/194, 13%), (d) lack of enteric contrast (15/194, 8%), and (e) low mA (8/194, 4%). Discrepancies were seen most commonly in detecting lymphadenopathy and visceral metastases. CONCLUSION: Most missed findings on the unenhanced CT portion of the PET/CT scans were due to technical factors that could be altered. Discrepant findings would have led to altered management in only 2 patients, suggesting a role for limited repeat imaging to reduce radiation and use of valuable resources. 相似文献
30.