全文获取类型
收费全文 | 919篇 |
免费 | 46篇 |
国内免费 | 3篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 27篇 |
妇产科学 | 27篇 |
基础医学 | 133篇 |
口腔科学 | 36篇 |
临床医学 | 69篇 |
内科学 | 135篇 |
皮肤病学 | 39篇 |
神经病学 | 89篇 |
特种医学 | 40篇 |
外科学 | 192篇 |
综合类 | 17篇 |
预防医学 | 32篇 |
眼科学 | 23篇 |
药学 | 74篇 |
中国医学 | 4篇 |
肿瘤学 | 28篇 |
出版年
2024年 | 2篇 |
2023年 | 2篇 |
2022年 | 16篇 |
2021年 | 41篇 |
2020年 | 19篇 |
2019年 | 38篇 |
2018年 | 27篇 |
2017年 | 13篇 |
2016年 | 27篇 |
2015年 | 31篇 |
2014年 | 56篇 |
2013年 | 54篇 |
2012年 | 73篇 |
2011年 | 74篇 |
2010年 | 46篇 |
2009年 | 45篇 |
2008年 | 49篇 |
2007年 | 43篇 |
2006年 | 43篇 |
2005年 | 28篇 |
2004年 | 26篇 |
2003年 | 16篇 |
2002年 | 19篇 |
2001年 | 18篇 |
2000年 | 17篇 |
1999年 | 7篇 |
1998年 | 9篇 |
1997年 | 12篇 |
1996年 | 14篇 |
1995年 | 10篇 |
1992年 | 2篇 |
1991年 | 9篇 |
1990年 | 3篇 |
1989年 | 3篇 |
1988年 | 4篇 |
1987年 | 6篇 |
1986年 | 7篇 |
1985年 | 9篇 |
1984年 | 6篇 |
1983年 | 3篇 |
1982年 | 5篇 |
1981年 | 2篇 |
1980年 | 5篇 |
1979年 | 2篇 |
1978年 | 3篇 |
1977年 | 5篇 |
1976年 | 5篇 |
1975年 | 2篇 |
1973年 | 4篇 |
1970年 | 4篇 |
排序方式: 共有968条查询结果,搜索用时 15 毫秒
1.
Paul Devakar Yesudian MD Srivilliputtur G.S. Krishnan MBBS Muriugaiya Jayaraman MD Vanakampadi R. Janaki MD Patrick Yesudian FRCP 《International journal of dermatology》1997,36(3):194-196
Background Pemphigus is a group of vesiculobullous disorders in which the blisters usually heal with hyper- or hypopigmentation. The appearance of acanthomata at sites of previous blisters has been noted in some cases. Methods All cases of pemphigus admitted to the Madras Medical College hospitals during a 2-year period from March 1993 to March 1995 were taken into the study and screened for the presence of acanthomata. Results Fifty-two cases of pemphigus were identified, 47 of pemphigus vulgaris and five of pemphigus foliaceus; and of these 13 developed acanthomata when the blisters healed. Ten of these cases were of pemphigus vulgaris and three were of pemphigus foliaceus; biopsy of these lesions showed hyperkeratosis, acanthosis, papillomatosis, and intraepidermal clefting. Immunofluorescence carried out in two of these acanthomata also showed intercellular fluorescence. Conclusions The occurrence of acanthomata in healed lesions of pemphigus is not uncommon; because histopathologic and immunofluorescence evidence of disease activity is present, cases of this sort require careful follow-up. 相似文献
2.
J. L. Hedrick K. Carter M. Sanchez R. Di Pietro S. Swanson S. Jayaraman J. G. McGrath 《Macromolecular chemistry and physics.》1997,198(2):549-559
A new route for the synthesis of high glass transition temperature, thermally stable polymer foams has been developed, using compositionally asymmetric microphase-separated block copolymers where the minor component (poly(propylene oxide)) is thermally labile and the major component (polyimide) is thermally stable. The minor component decomposes to low molecular weight species upon heating, and the decomposition products diffuse out of the film, leaving behind pores embedded in a matrix of the thermally stable component. In this study, the polyimide block was crosslinked with ethynyl functionalities to obtain a stable porous structure. The decomposition of the propylene oxide in the block copolymer was studied by thermogravimetric, dynamic mechanical and thermomechanical analyses. Mild conditions were required to avoid rapid depolymerization of the propylene oxide and plasticization of the polyimide matrix. The foams showed pore sizes with diameters up to a micrometer in size as well as the expected reduction in the mass density. 相似文献
3.
Inhibition of interleukin-2 production by adherent cell factors from lepromatous leprosy patients. 总被引:1,自引:2,他引:1
下载免费PDF全文
![点击此处可从《Clinical and experimental immunology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
I Nath J Jayaraman M Sathish L K Bhutani A K Sharma 《Clinical and experimental immunology》1984,58(3):531-538
Twenty-four hour supernatants (MoF) were obtained from monocyte rich 2 h adherent cells of 19 leprosy patients and four healthy contacts. MoF from borderline and lepromatous patients produced 52-61% inhibition of human interleukin-2 (IL-2) production by a PHA conditioned T cell line (Jurkat). Non-adherent cell supernatants and MoF from tuberculoid and healthy individuals had little effect on IL-2 production. The suppression effected by MoF was in the first 12 h of initiation of PHA stimulated Jurkat cell cultures. Suppressive MoF did not interfere with (1) IL-2 release, (2) IL-2 utilization by Con A-induced T cell blasts or (3) constitutive proliferation of Jurkat cells. Such MoF were released spontaneously from adherent cells of bacilliferous leprosy patients but required in vitro antigen triggering in long term treated lepromatous patients. It is possible that the unresponsiveness associated with lepromatous leprosy is related to the inhibition of IL-2 production by suppressive factors, thereby, preventing the further expansion of antigen reactive T cells. 相似文献
4.
The delayed-type hypersensitivity (DTH) reaction to the phenyltrimethylamino (TMA) hapten in mice has been investigated. TMA-derivatized syngeneic spleen cells (TMA-SC) administered s.c. in several strains of mice consistently evoked DTH reactivity, as measured by footpad swelling after challenge with the diazonium salt of TMA. DTH could be induced by low levels of anti-idiotypic antisera (anti-Id) in lieu of antigen. The DTH reaction induced by either mode was hapten-specific, could be transferred into naive recipients by viable lymph node cells but not with serum from immune mice and was not influenced by cyclophoshamide pretreatment. Unlike TMA-SC which induced DTH in all of the strains of the mice tested, anti-Id induced DTH only in strains of the Igh-1e allotype. Positive DTH reactions were induced by anti-Id in the C57.Ige strain (H-2b, Igh-1e) but not in its allotype-congenic partner C57BL/6J (H-2b, Igh-1b). Interestingly this reaction could be suppressed if relatively high amounts of anti-Id were inoculated i.v. just prior to antigen challenge. In addition, the administration of anti-Id 1 h prior to antigen challenge in TMA-SC-sensitized mice significantly blocked the DTH reaction only in the Igh-1e strains. These results demonstrate that the induction and abrogation of TMA-specific DTH by anti-Id is linked to the IgCh locus. 相似文献
5.
6.
Clomiphene, a selective oestrogen receptor modulator, has been utilised in managing male sub-fertility since 1967. Numerous controlled and uncontrolled studies have been published regarding the efficacy of clomiphene citrate in male sub-fertility cohorts. Although the primary intention of treating men with clomiphene citrate is to improve sperm parameters and testosterone levels, some studies have reported paradoxical decline in semen parameters. The information available on decline in sperm parameters following treatment with clomiphene is sparse. We conducted a systemic review using PubMed, Embase, Cochrane Library and Scopus databases for original studies reporting adverse effects of clomiphene citrate therapy on sperm parameters. This systematic review includes 384 men from 11 different studies that reported adverse effects of clomiphene citrate therapy. Of the men included in these studies, 19%, 21%, 17% and 24% of clomiphene-treated men demonstrated a decrease in sperm count, concentration, motility and total motile sperm count respectively. In up to 17% of patients, deterioration of semen parameters did not recover following discontinuation of therapy. In the future, more studies should report on this aspect so the magnitude of this effect can be more clearly understood. 相似文献
7.
Manish Kuchakulla Manish Narasimman Kajal Khodamoradi Zahra Khosravizadeh Ranjith Ramasamy 《Andrologia》2021,53(1):e13615
Spermatogenesis is the essential process to maintain and promote male fertility. It is extraordinarily complex with many regulatory elements and numerous steps. The process involves several cell types, regulatory molecules, repair mechanisms and epigenetic regulators. Evidence has shown that fertility can be negatively impacted by reduced sperm DNA integrity. Sources of sperm DNA damage include replication errors and causes of DNA fragmentation which include abortive apoptosis, defective maturation and oxidative stress. This review outlines the process of spermatogenesis, spermatogonial regulation and sperm differentiation; additionally, DNA damage and currently studied DNA repair mechanisms in spermatozoon are also covered. 相似文献
8.
Jordan C. Best BS Taylor Kohn MD Premal Patel MD Ruben Blachman-Braun MD Elaine de Quadros PhD Zeki Beyhan PhD Michael Jacobs MD Ranjith Ramasamy MD 《Andrologia》2021,53(7):e14094
In this study, we sought to determine whether sperm DNA fragmentation (DFI%) and high DNA stainability (HDS%) evaluated by sperm chromatin structure assay (SCSA) predict recurrent implantation failure (RIF) or pregnancy rate. A retrospective study was performed of consecutive cycles of ICSI treatment from 2009 to 2018. A total of 386 couples that underwent 1,216 frozen embryo transfer (FET) cycles were analysed. Mean female and male age was 34 ± 3.6 years and 37.3 ± 6.6 years, respectively, and a median total motile sperm count (TMSC) was 43.5 [9.9–105.5] million. Overall median DFI% and HDS% was 12 [7.1–18.9] and 9.6 [6.5–14.4] respectively. On multivariable analysis, DFI% and HDS% were not associated with RIF (DFI%: OR = 1.01, 95% CI: 0.98–1.04, p = .414; HDS%: OR = 0.97, 95% CI: 0.94–1.01, p = .107) or IVF success, defined as clinical pregnancy (DFI%: OR = 1.00, 95% CI: 0.99–1.01, p = .641; HDS%: OR = 1.01, 95% CI: 0.99–1.02, p = .565). We found that neither DFI% or HDS%, as assessed by SCSA, were predictive of RIF or pregnancy rate. This finding suggests that sperm DNA fragmentation does not predict RIF or pregnancy rate. 相似文献
9.
10.
Cholecystokinin and neurotensin mRNAs are differentially expressed in subnuclei of the ventral tegmental area 总被引:1,自引:0,他引:1
Immunohistochemical studies of ventral tegmental area (VTA) neurons indicate that individual cells can contain dopamine as well as the neuropeptide neurotransmitters cholecystokinin (CCK) and neurotensin (NT). We have defined the distribution of the cells expressing the mRNAs encoding these two dopamine cotransmitter peptides in each of the subnuclei of the ventral tegmental area, and quantitated the extent of expression of each gene by using in situ hybridization methods. These studies reveal significant differences in the patterns of expression of each of these two genes within various subdivisions of the VTA. The rostral linear nucleus contained numerous CCK positive cells, some of which appeared to express preproCCK-mRNA at a very high level, but this nucleus contained relatively few NT-expressing cells. The parabrachialis pigmentosus contained numerous NT and CCK positive cells. The paranigralis and interfascicularis nuclei displayed positive CCK cells but with expression at only modest levels. NT cells were very few in these nuclei. The caudal linear nuclei contained the highest number of NT-expressing neurons and these cells expressed very high levels of NT mRNA. The selective distribution of these peptide genes within the VTA subnuclei may have specific consequences. Studies of the connectivity of neurons in the VTA show that the different subnuclei of this region project to several functionally and architectonically different regions of the cerebral cortex and subcortically to nuclei related to the limbic system. Results from our study show very prominent expression of CCK mRNAs in those subnuclei that project heavily to the prefrontal, other cortical areas, and the amygdaloid complex. The NT gene is expressed prominently in those subnuclei of VTA that project heavily to the entorhinal cortex and amygdaloid complex. These results provide support for a differential role for the NT-expressing neurons than that of CCK-expressing neurons of VTA in "reward" mechanisms and in drug-seeking and motivational behavior. These observations could be applied to create working hypotheses and experimental paradigms to test the differential functional activity of the subdivisions of VTA and their potential roles in the pathogenesis and treatment of drug-seeking behavior and other neuropsychiatric disorders. 相似文献