全文获取类型
收费全文 | 1417篇 |
免费 | 133篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 33篇 |
妇产科学 | 9篇 |
基础医学 | 152篇 |
口腔科学 | 32篇 |
临床医学 | 154篇 |
内科学 | 230篇 |
皮肤病学 | 35篇 |
神经病学 | 70篇 |
特种医学 | 62篇 |
外科学 | 320篇 |
综合类 | 92篇 |
一般理论 | 3篇 |
预防医学 | 151篇 |
眼科学 | 10篇 |
药学 | 101篇 |
中国医学 | 1篇 |
肿瘤学 | 101篇 |
出版年
2021年 | 19篇 |
2020年 | 17篇 |
2019年 | 20篇 |
2018年 | 21篇 |
2017年 | 32篇 |
2016年 | 27篇 |
2015年 | 33篇 |
2014年 | 31篇 |
2013年 | 52篇 |
2012年 | 46篇 |
2011年 | 37篇 |
2010年 | 33篇 |
2009年 | 54篇 |
2008年 | 47篇 |
2007年 | 62篇 |
2006年 | 48篇 |
2005年 | 45篇 |
2004年 | 47篇 |
2003年 | 34篇 |
2002年 | 49篇 |
2001年 | 35篇 |
2000年 | 50篇 |
1999年 | 47篇 |
1998年 | 27篇 |
1997年 | 31篇 |
1996年 | 23篇 |
1995年 | 21篇 |
1994年 | 12篇 |
1993年 | 17篇 |
1992年 | 43篇 |
1991年 | 30篇 |
1990年 | 26篇 |
1989年 | 19篇 |
1988年 | 32篇 |
1987年 | 33篇 |
1986年 | 23篇 |
1985年 | 34篇 |
1984年 | 20篇 |
1983年 | 26篇 |
1982年 | 22篇 |
1981年 | 12篇 |
1978年 | 20篇 |
1976年 | 13篇 |
1975年 | 19篇 |
1974年 | 13篇 |
1973年 | 14篇 |
1972年 | 13篇 |
1969年 | 15篇 |
1966年 | 13篇 |
1958年 | 11篇 |
排序方式: 共有1559条查询结果,搜索用时 0 毫秒
31.
J VALENTINE E ROSSI P O'LEARY TS PARRY JJ KURINCZUK P SLY 《Journal of paediatrics and child health》1997,33(2):117-120
To determine the prevalence of thyroid hormone abnormalities and generalized resistance to thyroid hormone in a population of children with attention deficit hyperactivity disorder (ADHD) as compared to reference ranges determined from a control population and hence to determine if routine thyroid hormone screening in children with non-familial ADHD is indicated.
Children attending the State Child Development Centre in Perth, Western Australia with ADHD, as defined by the Diagnostic and Statistical Manual of Mental Disorders (fourth edition) provided the study population. The control population consisted of 353 normal children with a history of allergy in whom radioallergosorbent (RAST) testing was being performed.
The prevalence of thyroid hormone abnormalities in the study population was 2.3% (95% CI 0.6%, 5.7%). There were no cases of generalized resistance to thyroid hormone. The prevalence of thyroid hormone abnormalities in the general population of children and adolescents has been reported to vary between 1 and 3.7%.
Routine thyroid hormone screening is not indicated in children with non-familial ADHD. 相似文献
Method:
Children attending the State Child Development Centre in Perth, Western Australia with ADHD, as defined by the Diagnostic and Statistical Manual of Mental Disorders (fourth edition) provided the study population. The control population consisted of 353 normal children with a history of allergy in whom radioallergosorbent (RAST) testing was being performed.
Results:
The prevalence of thyroid hormone abnormalities in the study population was 2.3% (95% CI 0.6%, 5.7%). There were no cases of generalized resistance to thyroid hormone. The prevalence of thyroid hormone abnormalities in the general population of children and adolescents has been reported to vary between 1 and 3.7%.
Conclusion:
Routine thyroid hormone screening is not indicated in children with non-familial ADHD. 相似文献
32.
33.
Reeve TS Babidge WJ Parkyn RF Edis AJ Delbridge LW Devitt PG Maddern GJ 《Archives of surgery (Chicago, Ill. : 1960)》2000,135(4):481-487
HYPOTHESIS: Use of minimally invasive parathyroidectomy techniques, either unilateral or endoscopic, will result in the same or improved safety and efficacy outcomes as those of the bilateral open neck exploration technique in patients with primary hyperparathyroidism. DATA SOURCES: Studies on minimally invasive parathyroid surgery were identified using MEDLINE (January 1984 to August 1998), EMBASE (January 1974 to August 1998), and Current Contents (week 1 of 1993 to week 34 of 1998). The search terms were as follows: ((endoscop* or (minimal* and invasive) or unilateral) and parathyroid). The Cochrane Library was searched from issue 1 of 1966 to issue 3 of 1998, using the search terms "parathyroidectomy or parathyroid resection." STUDY SELECTION: Human studies of patients with primary hyperparathyroidism using unilateral or endoscopic exploration were included. Animal studies describing minimally invasive technique development were also included. A surgeon (R.F.P.) and researcher (W.J.B.) independently assessed the retrieved articles for their inclusion in the review. DATA EXTRACTION: Studies directly comparing the unilateral method with bilateral open neck exploration were used to analyze outcomes. DATA SYNTHESIS: Analysis of data using odds ratios and 95% confidence intervals indicated a tendency to favor the unilateral technique. However, these individual studies generally had large confidence intervals; therefore, preference to the unilateral procedure cannot be espoused with certainty. There is also a selection bias due to the strict enrollment criteria for unilateral surgery. CONCLUSIONS: The proposed role of minimally invasive parathyroid surgery is for patients with primary hyperparathyroidism who have unilateral parathyroid pathological features. To assess the safety and efficacy of minimally invasive techniques, it is suggested that their introduction be monitored as part of a trial in Australia, from which data should be accrued to a register. 相似文献
34.
35.
36.
Jeff Reeve Georg A. Böhmig Farsad Eskandary Gunilla Einecke Gaurav Gupta Katelynn Madill‐Thomsen Martina Mackova Philip F. Halloran INTERCOMEX MMDx‐Kidney Study Group 《American journal of transplantation》2019,19(10):2719-2731
We previously reported a system for assessing rejection in kidney transplant biopsies using microarray‐based gene expression data, the Molecular Microscope® Diagnostic System (MMDx). The present study was designed to optimize the accuracy and stability of MMDx diagnoses by replacing single machine learning classifiers with ensembles of diverse classifier methods. We also examined the use of automated report sign‐outs and the agreement between multiple human interpreters of the molecular results. Ensembles generated diagnoses that were both more accurate than the best individual classifiers, and nearly as stable as the best, consistent with expectations from the machine learning literature. Human experts had ≈93% agreement (balanced accuracy) signing out the reports, and random forest‐based automated sign‐outs showed similar levels of agreement with the human experts (92% and 94% for predicting the expert MMDx sign‐outs for T cell–mediated (TCMR) and antibody‐mediated rejection (ABMR), respectively). In most cases disagreements, whether between experts or between experts and automated sign‐outs, were in biopsies near diagnostic thresholds. Considerable disagreement with histology persisted. The balanced accuracies of MMDx sign‐outs for histology diagnoses of TCMR and ABMR were 73% and 78%, respectively. Disagreement with histology is largely due to the known noise in histology assessments (ClinicalTrials.gov NCT01299168). 相似文献
37.
38.
A hydrogenase-linked gene in Methanobacterium thermoautotrophicum strain delta H encodes a polyferredoxin. 总被引:11,自引:2,他引:11 下载免费PDF全文
J N Reeve G S Beckler D S Cram P T Hamilton J W Brown J A Krzycki A F Kolodziej L Alex W H Orme-Johnson C T Walsh 《Proceedings of the National Academy of Sciences of the United States of America》1989,86(9):3031-3035
The genes mvhDGA, which encode the subunit polypeptides of the methyl viologen-reducing hydrogenase in Methanobacterium thermoautotrophicum strain delta H, have been cloned and sequenced. These genes, together with a fourth open reading frame designated mvhB, are tightly linked and appear to form an operon that is transcribed starting 42 base pairs upstream of mvhD. The organization and sequences of the mvhG and mvhA genes indicate a common evolutionary ancestry with genes encoding the small and large subunits of hydrogenases in eubacterial species. The product of the mvhB gene is predicted to contain six tandomly repeated bacterial-ferredoxin-like domains and, therefore, is predicted to be a polyferredoxin that could contain as many as 48 iron atoms in 12 Fe4S4 clusters. 相似文献
39.
Ariel R. Green Cynthia M. Boyd Kathy S. Gleason Leslie Wright Courtney R. Kraus Ruth Bedoy Bianca Sanchez Jonathan Norton Orla C. Sheehan Jennifer L. Wolff Emily Reeve Matthew L. Maciejewski Linda A. Weffald Elizabeth A. Bayliss 《Journal of general internal medicine》2020,35(12):3556
BackgroundPatients with dementia and multiple chronic conditions (MCC) frequently experience polypharmacy, increasing their risk of adverse drug events.ObjectivesTo elucidate patient, family, and physician perspectives on medication discontinuation and recommended language for deprescribing discussions in order to inform an intervention to increase awareness of deprescribing among individuals with dementia and MCC, family caregivers and primary care physicians. We also explored participant views on culturally competent approaches to deprescribing.DesignQualitative approach based on semi-structured interviews with patients, caregivers, and physicians.ParticipantsPatients aged ≥ 65 years with claims-based diagnosis of dementia, ≥ 1 additional chronic condition, and ≥ 5 chronic medications were recruited from an integrated delivery system in Colorado and an academic medical center in Maryland. We included caregivers when present or if patients were unable to participate due to severe cognitive impairment. Physicians were recruited within the same systems and through snowball sampling, targeting areas with large African American and Hispanic populations.ApproachWe used constant comparison to identify and compare themes between patients, caregivers, and physicians.Key ResultsWe conducted interviews with 17 patients, 16 caregivers, and 16 physicians. All groups said it was important to earn trust before deprescribing, frame deprescribing as routine and positive, align deprescribing with goals of dementia care, and respect caregivers’ expertise. As in other areas of medicine, racial, ethnic, and language concordance was important to patients and caregivers from minority cultural backgrounds. Participants favored direct-to-patient educational materials, support from pharmacists and other team members, and close follow-up during deprescribing. Patients and caregivers favored language that explained deprescribing in terms of altered physiology with aging. Physicians desired communication tips addressing specific clinical situations.ConclusionsCulturally sensitive communication within a trusted patient-physician relationship supplemented by pharmacists, and language tailored to specific clinical situations may support deprescribing in primary care for patients with dementia and MCC.Electronic supplementary materialThe online version of this article (10.1007/s11606-020-06063-y) contains supplementary material, which is available to authorized users.KEY WORDS: deprescribing, patient-physician communication, dementia 相似文献
40.
Insulin receptors on leukemia and lymphoma cells 总被引:1,自引:0,他引:1
Tumor cells obtained from leukemia and lymphoma patients were investigated for specific insulin receptors. Using radioactive 125I- labeled insulin, specific insulin binding sites were demonstrated on most acute lymphocytic leukemia (ALL) and acute myelocytic leukemia (AML) cells, including acute promyelocytic leukemia (APL), chronic myelocytic leukemia (CML), and acute monocytic leukemia (AMoL) cells. Insulin receptors were not found on chronic lymphocytic leukemia (CLL) and malignant lymphoma (ML) cells. Specific insulin binding sites were also found on monocytes and thymocytes after treatment with phytohemagglutinin (PHA-P), but not on inactivated tonsil cells, peripheral blood lymphocytes, or thymocytes. There was no inverse correlation between the content of insulin receptors and the basal level of circulating insulin. These data suggest that the insulin receptor may be a new marker of acute leukemia and chronic myelocytic leukemia. 相似文献