首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   4463篇
  免费   344篇
  国内免费   22篇
耳鼻咽喉   38篇
儿科学   113篇
妇产科学   89篇
基础医学   565篇
口腔科学   110篇
临床医学   611篇
内科学   801篇
皮肤病学   30篇
神经病学   313篇
特种医学   269篇
外科学   607篇
综合类   106篇
一般理论   2篇
预防医学   476篇
眼科学   24篇
药学   344篇
中国医学   13篇
肿瘤学   318篇
  2022年   36篇
  2021年   69篇
  2020年   46篇
  2019年   91篇
  2018年   100篇
  2017年   77篇
  2016年   85篇
  2015年   83篇
  2014年   121篇
  2013年   263篇
  2012年   228篇
  2011年   231篇
  2010年   149篇
  2009年   133篇
  2008年   208篇
  2007年   225篇
  2006年   205篇
  2005年   172篇
  2004年   154篇
  2003年   140篇
  2002年   137篇
  2001年   125篇
  2000年   119篇
  1999年   113篇
  1998年   54篇
  1997年   45篇
  1996年   56篇
  1995年   43篇
  1994年   51篇
  1993年   45篇
  1992年   99篇
  1991年   77篇
  1990年   74篇
  1989年   76篇
  1988年   72篇
  1987年   59篇
  1986年   72篇
  1985年   44篇
  1984年   43篇
  1983年   32篇
  1980年   25篇
  1979年   31篇
  1978年   30篇
  1976年   31篇
  1975年   34篇
  1974年   31篇
  1973年   32篇
  1972年   32篇
  1971年   26篇
  1968年   26篇
排序方式: 共有4829条查询结果,搜索用时 46 毫秒
81.
OBJECTIVE: This study aimed to a) compare the efficacy of metoclopramide and erythromycin in the treatment of feed intolerance in critical illness; and b) determine the effectiveness of "rescue" combination therapy in patients who fail monotherapy. DESIGN: Randomized controlled trial. SETTING: Level III mixed medical and surgical intensive care unit. PATIENTS: Ninety mechanically ventilated, medical patients with feed-intolerance (gastric residual volume>or=250 mL). INTERVENTIONS: Patients received either metoclopramide 10 mg intravenously four times daily (n=45) or erythromycin 200 mg intravenously twice a day (n=45) in a double-blind, randomized fashion. After the first dose, nasogastric feeding was commenced and 6-hourly nasogastric aspirates were performed. If a gastric residual volume>or=250 mL recurred on treatment, open-label, combination therapy was given. Patients were studied for 7 days. Successful feeding was defined as 6-hourly gastric residual volume<250 mL with a feeding rate>or=40 mL/hr. MEASUREMENTS AND MAIN RESULTS: Demographic data, blood glucose levels, and use of inotropes, opioids, and benzodiazepines were similar between the two groups. After 24 hrs of treatment, both monotherapies reduced the mean gastric residual volume (metoclopramide, 830+/-32 mL to 435+/-30 mL, p<.0001; erythromycin, 798+/-33 mL to 201+/-19 mL, p<.0001) and improved the proportion of patients with successful feeding (metoclopramide=62% and erythromycin=87%). Treatment with erythromycin was more effective than metoclopramide, but the effectiveness of both treatments declined rapidly over time. In patients who failed monotherapy, rescue combination therapy was highly effective (day 1=92%) and maintained its effectiveness for the study duration (day 6=67%). High pretreatment gastric residual volume was associated with poor response to prokinetic therapy. CONCLUSIONS: In critical illness, erythromycin is more effective than metoclopramide in treating feed intolerance, but the rapid decline in effectiveness renders both treatments suboptimal. Rescue combination therapy is highly effective, and further study is required to examine its role as the first-line therapy.  相似文献   
82.
BACKGROUND: Although prior studies used the 66-item Rapid Estimate of Adult Literacy in Medicine (REALM instrument) for literacy assessment, researchers may require a shorter, validated instrument when designing interventions for clinical contexts. OBJECTIVE: To develop and validate a very brief literacy assessment tool, the REALM-Short Form (REALM-SF). PATIENTS: The model development, validation, and field testing validation samples included 1336, 164, and 50 patients, respectively. SETTING: General medicine and subspecialty clinics and medicine inpatient wards. DESIGN: For development and validation samples, indicator variables for REALM instrument items were evaluated as potential predictors of REALM instrument score by stepwise multiple regression analysis with subsequent bootstrap and confirmatory factor analysis of selected items. Pearson correlations compared REALM-SF and REALM instrument scores and kappa analyses compared grade level assignments. For the field testing validation sample, Pearson correlations compared Wide Range Achievement Test and REALM-SF scores. RESULTS: The REALM-SF included 7 items with stable model coefficients and 1 underlying linear factor. REALM-SF and REALM instrument scores were highly correlated in development (r = 0.95, P < 0.001) and validation (r = 0.94, P < 0.001) samples. There was excellent agreement between REALM-SF and REALM instrument grade-level assignments when dichotomized at the 6th grade (development: 97% agreement, K = 0.88, P < 0.001; validation: 88% agreement, K = 0.75, P < 0.001) and 8th grade levels (development: 94% agreement, K = 0.78, P < 0.001; validation: 84% agreement, K = 0.67, P < 0.001). REALM-SF and Wide Range Achievement Test scores were highly correlated (r = 0.83, P < 0.001) in field testing validation. CONCLUSIONS: The REALM-SF provides researchers a brief, validated instrument for assessing patient literacy in diverse research settings.  相似文献   
83.
84.
85.
86.
We report the generation and statistical analysis of the CSD drug subset: a subset of the Cambridge Structural Database (CSD) consisting of every published small-molecule crystal structure containing an approved drug molecule. By making use of InChI matching, a CSD Python API workflow to link CSD entries to the online database Drugbank.ca has been produced. This has resulted in a subset of 8632 crystal structures, representing all published solid forms of 785 unique drug molecules. We hope that this new resource will lead to improvements in targeted cheminformatics and statistical model building in a pharmaceutical setting. In addition to this, as part of the Advanced Digital Design of Pharmaceutical Therapeutics collaboration between academia and industry, we have been given the unique opportunity to run comparative analysis on the internal crystal structure databases of AstraZeneca and Pfizer, alongside comparison to the CSD as a whole.  相似文献   
87.
BackgroundWith increasing attention given to the quality of chronic disease care, a measurement approach that empowers consumers to participate in improving quality of care and enables health services to systematically introduce patient-centered initiatives is needed. A Web-based survey with complex adaptive questioning and interactive survey items would allow consumers to easily identify and prioritize detailed service initiatives.ObjectiveThe aim was to develop and test a Web-based survey capable of identifying and prioritizing patient-centered initiatives in chronic disease outpatient services. Testing included (1) test-retest reliability, (2) patient-perceived acceptability of the survey content and delivery mode, and (3) average completion time, completion rates, and Flesch-Kincaid reading score.MethodsIn Phase I, the Web-based Consumer Preferences Survey was developed based on a structured literature review and iterative feedback from expert groups of service providers and consumers. The touchscreen survey contained 23 general initiatives, 110 specific initiatives available through adaptive questioning, and a relative prioritization exercise. In Phase II, a pilot study was conducted within 4 outpatient clinics to evaluate the reliability properties, patient-perceived acceptability, and feasibility of the survey. Eligible participants were approached to complete the survey while waiting for an appointment or receiving intravenous therapy. The age and gender of nonconsenters was estimated to ascertain consent bias. Participants with a subsequent appointment within 14 days were asked to complete the survey for a second time.ResultsA total of 741 of 1042 individuals consented to participate (71.11% consent), 529 of 741 completed all survey content (78.9% completion), and 39 of 68 completed the test-retest component. Substantial or moderate reliability (Cohen’s kappa>0.4) was reported for 16 of 20 general initiatives with observed percentage agreement ranging from 82.1%-100.0%. The majority of participants indicated the Web-based survey was easy to complete (97.9%, 531/543) and comprehensive (93.1%, 505/543). Participants also reported the interactive relative prioritization exercise was easy to complete (97.0%, 189/195) and helped them to decide which initiatives were of most importance (84.6%, 165/195). Average completion time was 8.54 minutes (SD 3.91) and the Flesch-Kincaid reading level was 6.8. Overall, 84.6% (447/529) of participants indicated a willingness to complete a similar survey again.ConclusionsThe Web-based Consumer Preferences Survey is sufficiently reliable and highly acceptable to patients. Based on completion times and reading level, this tool could be integrated in routine clinical practice and allows consumers to easily participate in quality evaluation. Results provide a comprehensive list of patient-prioritized initiatives for patients with major chronic conditions and delivers practice-ready evidence to guide improvements in patient-centered care.  相似文献   
88.
The taste system of catfish, having distinct taste receptor sites for L-alanine and L-arginine, is highly sensitive to amino acids. A previously described monoclonal antibody (G-10), which inhibits L-alanine binding to a partial membrane fraction (P2) derived from catfish (Ictalurus punctatus) taste epithelium, was found in Western blots to recognize a single band, at apparent MW of 113,000 D. This MW differs from the apparent MW for the presumed arginine receptor identified previously by PHA-E lectin affinity. In order to test whether PHA-E lectin actually reacts with the arginine-receptor, reconstituted membrane proteins partially purified by PHA-E affinity were used in artificial lipid bilayers. These reconstituted channels exhibited L-arginine-activated activity similar to that found in taste cell membranes. Accordingly, we utilized the PHA-E lectin and G-10 antibody as probes to differentially localize the L-alanine and L-arginine binding sites on the apical surface of catfish taste buds. Each probe labels numerous, small (0.5–1.0 μm) patches within the taste pore of each taste bud. This observation suggests that each bud is not tuned to a single taste substance, but contains putative receptor sites for both L-arginine and L-alanine. Further, analysis of double-labeled tissue reveals that the PHA-E and G-10 sites tend to be separate within each taste pore. These findings imply that in catfish, individual taste cells preferentially express receptors to either L-arginine or L-alanine. In addition, PHA-E binds to the apices of solitary chemoreceptor cells in the epithelium, indicating that this independent chemoreceptor system may utilize some receptor sites similar to those in taste buds. © 1996 Wiley-Liss, Inc.  相似文献   
89.
This report describes how a community library was identified as a need and was ultimately established in a Nigerian community. The Africa Book Project illustrates the challenges presented in applying theories of empowerment developed in the United States in an international setting and how the problems were resolved. The report examines the events through which a resource network was created as an organizing mechanism at both the individual and the collective levels. The report discusses the impact of subjective culture on the implementation of the field research. Lessons that can be applied in US communities, and the theoretical questions they raise, are presented.  相似文献   
90.
BackgroundPhysician responsiveness to patient preferences for depression treatment may improve treatment adherence and clinical outcomes.ObjectiveTo examine associations of patient treatment preferences with types of depression treatment received and treatment adherence among Veterans initiating depression treatment.DesignPatient self-report surveys at treatment initiation linked to medical records.SettingVeterans Health Administration (VA) clinics nationally, 2018–2020.ParticipantsA total of 2582 patients (76.7% male, mean age 48.7 years, 62.3% Non-Hispanic White)Main MeasuresPatient self-reported preferences for medication and psychotherapy on 0–10 self-anchoring visual analog scales (0=“completely unwilling”; 10=“completely willing”). Treatment receipt and adherence (refilling medications; attending 3+ psychotherapy sessions) over 3 months. Logistic regression models controlled for socio-demographics and geographic variables.Key ResultsMore patients reported strong preferences (10/10) for psychotherapy than medication (51.2% versus 36.7%, McNemar χ21=175.3, p<0.001). A total of 32.1% of patients who preferred (7–10/10) medication and 21.8% who preferred psychotherapy did not receive these treatments. Patients who strongly preferred medication were substantially more likely to receive medication than those who had strong negative preferences (odds ratios [OR]=17.5; 95% confidence interval [CI]=12.5–24.5). Compared with patients who had strong negative psychotherapy preferences, those with strong psychotherapy preferences were about twice as likely to receive psychotherapy (OR=1.9; 95% CI=1.0–3.5). Patients who strongly preferred psychotherapy were more likely to adhere to psychotherapy than those with strong negative preferences (OR=3.3; 95% CI=1.4–7.4). Treatment preferences were not associated with medication or combined treatment adherence. Patients in primary care settings had lower odds of receiving (but not adhering to) psychotherapy than patients in specialty mental health settings. Depression severity was not associated with treatment receipt or adherence.ConclusionsMismatches between treatment preferences and treatment type received were common and associated with worse treatment adherence for psychotherapy. Future research could examine ways to decrease mismatch between patient preferences and treatments received and potential effects on patient outcomes.Supplementary InformationThe online version contains supplementary material available at 10.1007/s11606-021-07136-2.KEY WORDS: major depression, treatment preferences, treatment adherence, Veterans  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号