全文获取类型
收费全文 | 1351篇 |
免费 | 76篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 18篇 |
妇产科学 | 27篇 |
基础医学 | 285篇 |
口腔科学 | 4篇 |
临床医学 | 131篇 |
内科学 | 350篇 |
皮肤病学 | 9篇 |
神经病学 | 166篇 |
特种医学 | 31篇 |
外科学 | 104篇 |
综合类 | 3篇 |
现状与发展 | 1篇 |
一般理论 | 2篇 |
预防医学 | 61篇 |
眼科学 | 13篇 |
药学 | 100篇 |
中国医学 | 5篇 |
肿瘤学 | 125篇 |
出版年
2024年 | 3篇 |
2023年 | 47篇 |
2022年 | 92篇 |
2021年 | 134篇 |
2020年 | 47篇 |
2019年 | 71篇 |
2018年 | 60篇 |
2017年 | 31篇 |
2016年 | 44篇 |
2015年 | 62篇 |
2014年 | 55篇 |
2013年 | 65篇 |
2012年 | 84篇 |
2011年 | 94篇 |
2010年 | 56篇 |
2009年 | 42篇 |
2008年 | 71篇 |
2007年 | 74篇 |
2006年 | 77篇 |
2005年 | 78篇 |
2004年 | 54篇 |
2003年 | 33篇 |
2002年 | 22篇 |
2001年 | 4篇 |
2000年 | 4篇 |
1999年 | 6篇 |
1998年 | 10篇 |
1997年 | 2篇 |
1996年 | 4篇 |
1995年 | 4篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1987年 | 1篇 |
1982年 | 1篇 |
1978年 | 1篇 |
排序方式: 共有1436条查询结果,搜索用时 15 毫秒
81.
Stroev SA Gluschenko TS Tjulkova EI Spyrou G Rybnikova EA Samoilov MO Pelto-Huikko M 《Journal of neuroscience research》2004,78(4):563-569
The impact of severe hypoxia and preconditioning on the expression of the mitochondrial antioxidant thioredoxin-2 (Trx-2) in rat hippocampus (CA1, CA2, CA3 fields, and dentate gyrus) and neocortex was studied by immunocytochemistry. The preconditioning consisted of three trials of mild hypobaric hypoxia (360 Torr, 2 hr) spaced at 24 hr. The last trial was followed by severe hypobaric hypoxia (180 Torr, 3 hr) 24 hr later. Both in hippocampus and in neocortex, severe hypobaric hypoxia resulted in enhanced Trx-2 expression at 3 hr, followed by a slight decline in Trx-2 levels, which nevertheless remained increased at 24 hr elsewhere except for the CA1 region. The preconditioning considerably augmented severe hypoxia-induced Trx-2 immunoreactivity, affecting both the number of immunoreactive cells and the intensity of immunostaining. The findings suggest a role for Trx-2 in the formation of brain hypoxic/ischemic tolerance accomplished by the preconditioning. 相似文献
82.
Luis CA Barker WW Loewenstein DA Crum TA Rogaeva E Kawarai T St George-Hyslop P Duara R 《Dementia and geriatric cognitive disorders》2004,18(3-4):307-313
OBJECTIVE: To determine the conversion rates to dementia in patients diagnosed with mild cognitive impairment (MCI) thought to be caused by incipient Alzheimer's disease (MCI-AD) or with MCI with features of vascular disease (MCI-Vas). METHODS: On the basis of patient history, neurocognitive, neurological and MRI evaluation, 99 patients were diagnosed with MCI-AD and 35 with MCI-Vas. Conversion to dementia over an average of a 2.4 +/- 1.8-year period was determined. RESULTS: Over the follow-up period, 44% converted to dementia, 51.5% remained classified as MCI, and 4.5% were reclassified as cognitively normal. The conversion rate to dementia was significantly faster at 3 years for the MCI-AD (50.5%) than for the MCI-Vas group (25.7%). The neuropsychological test found to best differentiate converters from non-converters was the Fuld-OME, a measure of learning and recall. Age, education, gender or APOE epsilon4 allele frequency did not differentiate converters from non-converters. CONCLUSIONS: MCI-AD and MCI-Vas are clinically meaningful subtypes of MCI that may convert to dementia at different rates. Prospective studies on larger subsets of MCI patients are required to confirm these findings. 相似文献
83.
Popova NV Suleimanian NE Stepanova EA Teti KA Wu KQ Morris RJ 《The journal of investigative dermatology. Symposium proceedings / the Society for Investigative Dermatology, Inc. [and] European Society for Dermatological Research》2004,9(3):253-260
Mouse keratinocyte stem cells originate from the bulge of hair follicle, and, according to definition, possess a clonogenic activity in vitro. We have investigated seven inbred (C57BL/6, C3H, DBA/2, BALB/c, FVB) and outbred (SENCAR, CD-1) mouse strains and found that three genetically distinct subsets of mouse strains differ significantly in the frequency of clonogenic activity in vitro. The analysis of keratinocyte colonies in two reciprocal backcross [C57BL/6 x (BALB/c x C57BL/6); BALB/c x (BALB/c x C57BL/6)] and intercross [(BALB/c x C57BL/ 6)F2] of BALB/c and C57BL/6 mice allowed us to identify two subpopulations of clonogenic keratinocytes able to produce small (less than 2 mm2) and large (more than 2 mm2) colonies. We conducted linkage analysis and found that small colonies associated with mouse chromosomes 1, 6, 7, 8, and 9; but large colonies--with the chromosome 4. We defined locus on the chromosome 9 that associated with small colonies as keratinocyte stem cell locus 1 (Ksc1), and locus on the mouse chromosome 4 associated with large colonies-keratinocyte stem cell locus 2 (Ksc2). Ksc1 and loci on chromosomes 6 and 7 are close if not equal to loci associated with sensitivity to skin carcinogenesis. We conclude that two subpopulations of stem cells able to produce small and large colonies regulated by different genes and genes regulating small colonies might be responsible for sensitivity to skin carcinogenesis. 相似文献
84.
Surface modification of tricalcium phosphate for improvement of the interfacial compatibility with biodegradable polymers 总被引:4,自引:0,他引:4
The surface of tricalcium phosphate (TCP) filler particles was activated by treatment with dilute aqueous phosphoric acid. ATR-IR spectra indicated the formation of calcium hydrogen phosphate dihydrate at the surface. Oligo(lactone)s were formed by the subsequent reaction of the activated TCP with L-lactide and epsilon -caprolactone, respectively, at 150 degrees C without any additional catalysts. After extraction of the oligo(lactide), the residue of modified TCP-included calcium lactate whereas the water of crystallization of the dihydrate disappeared as shown by ATR-IR spectroscopy.Owing to the insolubility of TCP in common solvents, the analogous reaction between water-soluble disodium hydrogen phosphate dihydrate and L-lactide was used to study the kind of chemical bonds by high-resolution NMR spectroscopy. The 1H and 13C NMR spectra of the reaction product also pointed out the presence of calcium lactate. Additionally, signals were found indicating a covalent attachment of lactic acid units onto the phosphorus.For the preparation of composites, poly(L,DL-lactide) was mixed with TCP and modified TCP, respectively, in a ratio of 75/25 (w/w) and directly injection moulded into tensile test specimens at a barrel temperature of 180 degrees C. Although mechanical properties were not improved, scanning electron microscopy (SEM) indicated a better interfacial phase interaction in the composite with the modified TCP. Chemical bonds between filler and polymer matrix are assumed to be formed by transesterification reactions. 相似文献
85.
Lagarkova MA Koroleva EP Kuprash DV Boitchenko VE Kashkarova UA Nedospasov SA Shebzukhov YV 《Immunology letters》2003,85(1):71-74
Screening of expression cDNA libraries derived from human neoplasms with autologous sera (SEREX) is an established method for defining antigens immunogenic in individual cancer patients. Although the majority of SEREX-derived cDNA clones encode autoantigens, some of them represent shared cancer antigens with cancer-related serological profiles. Routine evaluation of multiple SEREX-derived clones in serological assays using panels of allogeneic sera from cancer patients is an important step towards defining disease parameters of diagnostic and prognostic significance. Here we show how the seroreactivity of multiple SEREX-derived antigens can be simultaneously evaluated using a rapid semi-quantitative protocol of allogeneic screening, which we call SMARTA (serological mini-arrays of recombinant tumor antigens). 相似文献
86.
87.
Insulin-like growth factor-I enhances lymphoid and myeloid reconstitution after allogeneic bone marrow transplantation 总被引:3,自引:0,他引:3
Alpdogan O Muriglan SJ Kappel BJ Doubrovina E Schmaltz C Schiro R Eng JM Greenberg AS Willis LM Rotolo JA O'Reilly RJ van den Brink MR 《Transplantation》2003,75(12):1977-1983
BACKGROUND: Prolonged immunodeficiency after allogeneic bone marrow transplantation (allo BMT) results in significant morbidity and mortality from infection. Previous studies in murine syngeneic BMT models have demonstrated that posttransplantation insulin-like growth factor (IGF)-I administration could enhance immune reconstitution. METHODS: To analyze the effects of IGF-I on immune reconstitution and graft-versus-host disease (GVHD) after allo BMT, we used murine models for MHC-matched and -mismatched allo BMT. Young (3-month-old) recipient mice received 4 mg/kg per day of human IGF-I from days 14 to 28 by continuous subcutaneous administration. RESULTS: IGF-I administration resulted in increased thymic precursor populations (triple negative-2 and triple negative-3) as determined on day 28 but had no effect on overall thymic cellularity. In the periphery, the numbers of donor-derived splenic CD3+ T cells were increased and these cells had an improved proliferative response to mitogen stimulation. IGF-I treatment also significantly increased the numbers of pro-, pre-, and mature B cells and myeloid cell populations in the spleens of allo BMT recipients on day 28. The administration of IGF-I in combination with interleukin 7 had a remarkable additive effect on B-cell, but not on T-cell, lymphopoiesis. Finally, we tested the effects of IGF-I administration on the development of GVHD in three different MHC-matched and -mismatched models and found no changes in GVHD morbidity and mortality. CONCLUSION: IGF-I administration can enhance lymphoid and myeloid reconstitution after allo BMT without aggravating GVHD. 相似文献
88.
Beta2-microglobulin aberrations in diffuse large B-cell lymphoma of the testis and the central nervous system 总被引:1,自引:0,他引:1
Jordanova ES Riemersma SA Philippo K Schuuring E Kluin PM 《International journal of cancer. Journal international du cancer》2003,103(3):393-398
Human leukocyte antigen (HLA) class I molecules are expressed on the surface of all nucleated cells and present antigenic peptides to cytotoxic T cells, thereby playing an important role in initiating the cellular anti-tumor immune response. We previously reported that loss of HLA class I expression in diffuse large B-cell lymphoma (DLBCL) of the central nervous system (CNS) and the testis is a common event. Loss of expression and mutations of the light chain of the HLA class I molecule, beta(2)-microglobulin (beta(2)m) have been described in a variety of human tumors and cell lines. In our study, we screened 15 DLBCL cases with a combined loss of HLA class I and beta(2)m expression for mutations in the latter gene by direct sequencing. Frame shift mutations in repetitive sequences within the beta(2)m gene leading to loss of functional beta(2)m were detected in 2 cases. Loss of heterozygosity (LOH) and fluorescent in situ hybridization (FISH) analysis for chromosome 15 exhibited loss of the remaining copy of the beta(2)m gene in both cases but also hemizygous deletions and monosomies in 6 additional cases. Since similar mutations in the beta(2)m gene have been associated with microsatellite instability (MSI), we used 8 markers to study MSI involvement in DLBCL. Low MSI was more frequent (33%) as compared to nodal DLBCL (n=15) but did not correlate with the beta(2)m mutations. Our data indicate that multiple mechanisms lead to downregulation of beta(2)m and concomitant loss of HLA class I expression in DLBCL. 相似文献
89.
Positron emission tomography agent 2-deoxy-2-[<Superscript>18</Superscript>F]fluoro-D-glucose has a therapeutic potential in breast cancer 总被引:1,自引:0,他引:1 下载免费PDF全文
Moadel RM Nguyen AV Lin EY Lu P Mani J Blaufox MD Pollard JW Dadachova E 《Breast cancer research : BCR》2003,5(6):R199-R205
Background
Novel approaches are needed for breast cancer patients in whom standard therapy is not effective. 2-Deoxy-2-[18F]fluoro-D-glucose (18F-FDG) was evaluated as a potential radiomolecular therapy agent in breast cancer animal models and, retrospectively, in patients with metastatic breast cancer. 相似文献90.
Ekaterina Burduli Celestina Barbosa-Leiker Susan Fleming Caroline J. Hollins Martin Colin R. Martin 《Journal of reproductive and infant psychology》2017,35(3):248-260
Objective: This research sought to test the measurement invariance of the Birth Satisfaction Scale-Revised (BSS-R) across United States (US) and United Kingdom (UK) samples. Multiple-group measurement was tested and latent means analysis compared levels of birth satisfaction across the samples. Method: Using Confirmatory Factor Analysis (CFA), data previously collected from 409 mothers (181 US mothers; 228 UK mothers) were used to examine the multiple-group measurement invariance of the BSS-R across US and UK samples. Results: A correlated factors BSS-R model demonstrated partial measurement invariance. US mothers had significantly lower birth satisfaction levels on the three BSS-R subscales. Conclusions: This research demonstrates that the BSS-R is a robust tool that can be used to reliably measure women’s birth satisfaction within and across the US and UK. 相似文献