全文获取类型
收费全文 | 19898篇 |
免费 | 1711篇 |
国内免费 | 81篇 |
专业分类
耳鼻咽喉 | 143篇 |
儿科学 | 590篇 |
妇产科学 | 800篇 |
基础医学 | 2482篇 |
口腔科学 | 297篇 |
临床医学 | 3407篇 |
内科学 | 3679篇 |
皮肤病学 | 499篇 |
神经病学 | 1857篇 |
特种医学 | 519篇 |
外科学 | 2034篇 |
综合类 | 114篇 |
一般理论 | 7篇 |
预防医学 | 2095篇 |
眼科学 | 429篇 |
药学 | 1055篇 |
1篇 | |
中国医学 | 19篇 |
肿瘤学 | 1663篇 |
出版年
2024年 | 35篇 |
2023年 | 341篇 |
2022年 | 376篇 |
2021年 | 727篇 |
2020年 | 535篇 |
2019年 | 601篇 |
2018年 | 851篇 |
2017年 | 608篇 |
2016年 | 727篇 |
2015年 | 774篇 |
2014年 | 956篇 |
2013年 | 1236篇 |
2012年 | 1683篇 |
2011年 | 1723篇 |
2010年 | 934篇 |
2009年 | 969篇 |
2008年 | 1252篇 |
2007年 | 1241篇 |
2006年 | 1096篇 |
2005年 | 1010篇 |
2004年 | 873篇 |
2003年 | 798篇 |
2002年 | 747篇 |
2001年 | 134篇 |
2000年 | 83篇 |
1999年 | 120篇 |
1998年 | 167篇 |
1997年 | 167篇 |
1996年 | 114篇 |
1995年 | 107篇 |
1994年 | 89篇 |
1993年 | 71篇 |
1992年 | 65篇 |
1991年 | 37篇 |
1990年 | 37篇 |
1989年 | 28篇 |
1988年 | 17篇 |
1987年 | 20篇 |
1986年 | 36篇 |
1985年 | 26篇 |
1984年 | 27篇 |
1983年 | 26篇 |
1982年 | 34篇 |
1981年 | 19篇 |
1980年 | 13篇 |
1979年 | 14篇 |
1978年 | 15篇 |
1977年 | 30篇 |
1976年 | 23篇 |
1975年 | 11篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
51.
Beth Gordesky-Gold John M. Warrick David P. Kutzler Karama C. Neal Christina M. Coughlin Laurie Tompkins 《Behavior genetics》1996,26(1):49-54
Larvae from seven laboratory strains and eight isofemale lines ofDrosophila melanogaster differ significantly with regard to their responses to light in a photokinesis assay in which the larvae are tested en masse.
Larvae from the CA-2 laboratorystock fail to disperse on assay plates, although observations of individual CA-2 larvae suggest
that the larvae are repelled by light. Larvae from all of the other laboratory stocks and all of the isofemale lines (except
LI2 and NC5) avoid light in the photokinesis assay. Larvae from some stocks are much more strongly repelled by light than
larvae from other stocks. LI2 larvae are unresponsive to light in most replicates of the photokinesis assay, while NC5 larvae
are consistently unresponsive to light. Observations of F1 heterozygotes suggest that the allele(s) that affects the vision of LI2 and NC5 larvae has net effects on the animals' behavior
that are partially dominant and recessive, respectively. 相似文献
52.
Fritz Thorey Christina Stukenborg-Colsman Henning Windhagen Carl Joachim Wirth 《Technology and health care》2008,16(2):85-92
Today the use of pneumatic tourniquet is commonly accepted in total knee arthroplasty (TKA) to reduce perioperative blood loss. There are a few prospective randomised and nonrandomised studies that compare the effect of tourniquet release timing in cementless or cemented unilateral TKA. However, many of these studies show an inadequate reporting and methodology. This randomized prospective study was designed to investigate the efficiency of tourniquet release timing in preventing perioperative blood loss in a simultaneous bilateral TKA study design. To our knowledge, this is the first study of its kind, in which the effect of tourniquet release timing on perioperative blood loss was investigated in simultaneous bilateral cemented TKA to compare both techniques intraindividually. In 20 patients (40 knees) one knee was operated with tourniquet release and hemostasis before wound closure, and the other knee with tourniquet release after wound closure and pressure dressing. We found no significant difference in total blood loss between both techniques (p=0.930), but a significant difference in operating time (p=0.035). There were no postoperative complications at a follow-up of 6 month. Other studies report an increase the blood loss in early tourniquet release and an increase the risk of early postoperative complications in deflation of tourniquet after wound closure. In this study we found no significant difference in perioperative blood loss and no increase of postoperative complications. Therefore, we recommend a tourniquet release after wound closure to reduce the duration of TKA procedure and to avoid possible risks of extended anaesthesia. 相似文献
53.
Krister W. Fjermestad Rene Huster Christina Thunberg Simen Stokke Claus H. Gravholt Anne‐Kristin Solbakk 《American journal of medical genetics. Part C, Seminars in medical genetics》2020,184(2):482-492
A few studies have examined neuropsychological functions, sleep, and mental health combined in Klinefelter syndrome (KS; 47,XXY). We investigated neuropsychological functions with standard tests, sleep with actigraphy, and self‐reported mental health in 30 men with KS (Mean age = 36.7 years) compared to 21 controls (Mean age = 36.8 years). Men with KS scored significantly lower on mental speed, attention span, working memory, inhibition, and set‐shifting tests, as well as overall IQ (mean effect size difference Cohen's d = 0.79). Men with KS had significantly longer night wakes, with no differences in other sleep variables (mean d = 0.34). Men with KS reported poorer mental health than controls (mean d = 1.16). Regression analyses showed neuropsychological functions explained variance in some sleep domains for men with KS but not for controls. Neuropsychological functions explained variance in some mental health domains for controls. For men with KS, however, verbal IQ was the only significant predictor of mental health. Altogether, men with KS display problems in neuropsychological functions and mental health but do not appear different from controls on most sleep parameters. Our findings indicate that relations between neuropsychological functions, sleep, and mental health differ between men with KS and controls. 相似文献
54.
55.
Christina Brahe Stefania Zappata Isabella Velon Enrico Bertini Serenella Servidei Pietro Tonali Giovanni Neri 《American journal of medical genetics. Part A》1993,45(3):408-411
Linkage analysis and prenatal prediction in families segregating autosomal recessive spinal muscular atrophy (SMA) has become feasible since the assignment of the locus responsible for type I-III SMA to region 5q12-q13.3. We have performed a segregation study of SMA in Italian families using molecular probes and highly informative PCR-based polymorphic markers. In one family, a 7-year-old boy affected with type III SMA and an 8-year-old apparently healthy brother had identical haplotypes. These findings prompted us to reexamine the apparently unaffected child. His neurological exam was normal. However, the electromyography (EMG) showed a pattern consistent with chronic SMA. To our knowledge this is the first example of presymptomatic diagnosis of SMA based on genotype analysis. © 1993 Wiley-Liss, Inc. 相似文献
56.
Christina T Teng Wesley Gladwell Clara Beard David Walmer Ching S Teng Robert Brenner 《Molecular human reproduction》2002,8(1):58-67
We have previously shown that the estrogen responsiveness of the human lactoferrin gene in a transient transfection system is mediated through an imperfect estrogen response element (ERE) and a steroidogenic factor 1 binding element (SFRE) 26 bp upstream from ERE. Reporter constructs containing SFRE and ERE respond to estrogen stimulation in a dose-dependent manner, whereas mutations at either one of the response elements severely impaired the estrogen responsiveness. In this study, we demonstrated that estrogen receptor (ERalpha) binds to the human lactoferrin gene ERE and forms two complexes in an electrophoresis mobility shift assay (EMSA). These complexes could be supershifted by an antibody to ERalpha. We also showed that in normal cycling women, lactoferrin gene expression in the endometrium increases during the proliferative phase and diminishes during the luteal phase. This in-vivo study thus supported the finding from transient transfection experiments that the human lactoferrin gene expression is elevated in an environment with a high level of estrogen. The estrogen effect on lactoferrin gene expression in the rhesus monkey endometrium was studied by Western blotting and immunohistochemistry. The immunohistochemistry results showed that immunoreactive lactoferrin protein was not detectable in the untreated ovariectomized monkey endometrium, was elevated by estrogen treatment, and was suppressed by sequential, combined estrogen plus progesterone treatment. In conclusion, this study has shown that lactoferrin gene expression is responsive to estrogen in primate endometrium. 相似文献
57.
Behavioral Upset in Medical Patients-Revised: Evaluation of a Parent Report Measure of Distress for Pediatric Populations 总被引:1,自引:0,他引:1
Examined the utility of a new parent-report measure designedspecifically for pediatric inpatients, the Behavioral Upsetin Medical Patients-Revised (BUMP-R). The BUMP-R was administeredto 151 mothers of hospitalized children ages 412 yearsthe day following the child's hospital admission. The BUMP-Rdemonstrated good internal consistency and a factor analysisrevealed four factors identified as negativity/agitation, amiability,dysphoria, and noncom-pliance. Children exhibiting behavioraldistress at home were more likely to experience adjustment problemsupon hospitalization. Demographic and illness-related variableswere not substantial risk factors for hospital adjustment difficulties. 相似文献
58.
Sylvie Degermann Christina Reilly Bernadette Scott Lynn Ogata Harald Von Boehmer David Lo 《European journal of immunology》1994,24(12):3155-3160
Autoimmune (type 1) diabetes mellitus in mouse, rat, and humans shares several features, including T lymphocyte infiltration into pancreatic islets and a dependence on permissive class II major histocompatibility complex (MHC) alleles. We report here on an experimental model involving mice that express influenza hemagglutinin (HA) under the control of the insulin promoter and, at the same time, a transgenic class II MHC-restricted T cell receptor (TcR) specific for an HA peptide. These mice spontaneously develop islet infiltrates resembling those found in NOD mice and most animals become diabetic within 8 weeks of age. Because of the availability of a clonotypic TcR antibody, we can be confident that the Ins-HA transgene does not induce any measurable alterations in the vast majority of T cells with the transgenic TcR in primary and secondary lymphoid organs. Continuous export of large numbers of HA-specific lymphocytes from the thymus was not required for the manifestation of the disease since mice thymectomized at 3 days after birth still developed the disease albeit with smaller infiltrates. 相似文献
59.
Hauff K Zamzow C Law WJ De Melo J Kennedy K Los M 《Archivum immunologiae et therapiae experimentalis》2005,53(4):308-320
In this review we focus on peptide- and peptidomimetic-based approaches that target autoimmune diseases and some pathologies of the central nervous system. Special attention is given to asthma, allergic rhinitis, osteoarthritis, and Alzheimer's disease, but other related pathologies are also reviewed, although to a lesser degree. Among others, drugs like Diacerhein and its active form Rhein, Pralnacasan, Anakinra (Kineret), Omalizumab, an antibody "BION-1", directed against the common beta-chain of cytokine receptors, are described below as well as attempts to target beta-amyloid peptide aggregation. Parts of the review are also dedicated to targeting of pathologic conditions in the brain and in other tissues with peptides as well as methods to deliver larger molecules through the "blood--brain barrier" by exploring receptor-mediated transport, or elsewhere in the body by using peptides as carriers through cellular membranes. In addition to highlighting current developments in the field, we also propose, for future drug targets, the components of the inflammasome protein complex, which is believed to initiate the activation of caspase- 1 dependent signaling events, as well as other pathways that signal inflammation. Thus we discuss the possibility of targeting inflammasome components for negative or positive modulation of an inflammatory response. 相似文献
60.
Background: Several forms of psychotherapy aim at improving their patients' emotional expressivity, which is considered to contribute to mental health. Studies on the success of such attempts are virtually absent. Aim: To develop a measure for assessing changes of emotional expressivity in the course of psychotherapy. Method: In study 1 (N = 321), we generated a pool of German adjectives referring to emotional expressivity and reduced the number of those adjectives by means of factor‐analysis. In study 2 (N = 103), we determined how emotional expressivity is related to the Big Five personality factors. Results: An expressivity scale of 12 items with highly satisfactory psychometric properties was construed. Emotional expressivity is substantially related to Extraversion and moderately related to Agreeableness and Openness. Conclusion: The scale is ideally suited for repeated assessments in the course of psychotherapy in multi‐agent (e.g., inpatient) settings. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献