全文获取类型
收费全文 | 345篇 |
免费 | 32篇 |
国内免费 | 1篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 17篇 |
妇产科学 | 14篇 |
基础医学 | 55篇 |
口腔科学 | 1篇 |
临床医学 | 29篇 |
内科学 | 69篇 |
皮肤病学 | 1篇 |
神经病学 | 28篇 |
特种医学 | 11篇 |
外科学 | 56篇 |
预防医学 | 15篇 |
眼科学 | 1篇 |
药学 | 13篇 |
肿瘤学 | 65篇 |
出版年
2022年 | 3篇 |
2021年 | 3篇 |
2020年 | 5篇 |
2019年 | 8篇 |
2018年 | 9篇 |
2017年 | 8篇 |
2016年 | 4篇 |
2015年 | 9篇 |
2014年 | 6篇 |
2013年 | 13篇 |
2012年 | 10篇 |
2011年 | 20篇 |
2010年 | 9篇 |
2009年 | 12篇 |
2008年 | 16篇 |
2007年 | 8篇 |
2006年 | 18篇 |
2005年 | 14篇 |
2004年 | 18篇 |
2003年 | 23篇 |
2002年 | 17篇 |
2001年 | 12篇 |
2000年 | 9篇 |
1999年 | 3篇 |
1998年 | 6篇 |
1997年 | 4篇 |
1996年 | 3篇 |
1995年 | 8篇 |
1992年 | 6篇 |
1991年 | 11篇 |
1990年 | 4篇 |
1989年 | 8篇 |
1988年 | 4篇 |
1987年 | 10篇 |
1986年 | 7篇 |
1985年 | 8篇 |
1984年 | 8篇 |
1983年 | 3篇 |
1982年 | 3篇 |
1981年 | 3篇 |
1980年 | 4篇 |
1979年 | 2篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1975年 | 2篇 |
1970年 | 3篇 |
1969年 | 2篇 |
1965年 | 1篇 |
1954年 | 1篇 |
1946年 | 1篇 |
排序方式: 共有378条查询结果,搜索用时 0 毫秒
1.
Integration and differentiation of human embryonic stem cells transplanted to the chick embryo. 总被引:3,自引:0,他引:3
Ronald S Goldstein Micha Drukker Benjamin E Reubinoff Nissim Benvenisty 《Developmental dynamics》2002,225(1):80-86
Human embryonic stem (ES) cells are pluripotent cells that can differentiate into a large array of cell types and, thus, hold promise for advancing our understanding of human embryology and for contributing to transplantation medicine. In this study, differentiation of human ES cells was examined in vivo by in ovo transplantation to organogenesis-stage embryos. Colonies of human ES cells were grafted into or in place of epithelial-stage somites of chick embryos of 1.5 to 2 days of development. The grafted human ES cells survived in the chick host and were identified by vital staining with carboxyfluorescein diacetate or use of a green fluorescent protein-expressing cells. Histologic analysis showed that human ES cells are easily distinguished from host cells by their larger, more intensely staining nuclei. Some grafted cells differentiated en masse into epithelia, whereas others migrated and mingled with host tissues, including the dorsal root ganglion. Colonies grafted directly adjacent to the host neural tube produced primarily structures with the morphology and molecular characteristics of neural rosettes. These structures contain differentiated neurons as shown by beta-3-tubulin and neurofilament expression in axons and cell bodies. Axons derived from the grafted cells penetrate the host nervous system, and host axons enter the structures derived from the graft. Our results show that human ES cells transplanted in ovo survive, divide, differentiate, and integrate with host tissues and that the host embryonic environment may modulate their differentiation. The chick embryo, therefore, may serve as an accessible and unique experimental system for the study of in vivo development of human ES cells. 相似文献
2.
Immunomodulation of vascular endothelium. 1. Ultrastructural changes following ultraviolet B irradiation of peripheral veins 总被引:1,自引:0,他引:1
M L Marin R E Gordon M A Hardy K Reemtsma A I Benvenisty 《The Journal of surgical research》1990,48(2):134-143
Immunologic function of endothelial cells is especially important in consideration of vein allografting for arterial reconstruction and in organ allotransplantation. Ultraviolet B radiation (UVB) has previously been shown to modulate graft immunogenicity, and to alter cell surface receptor function. In this study, superficial epigastric veins were UVB irradiated with 10, 24, 40, 80, and 150 mJ/cm2 while control veins were not irradiated; all specimens were examined for endothelial ultrastructural changes. Veins were perfuse-fixed at 1, 3, 7, 14, and 28 days after irradiation, and were evaluated by transmission electron microscopy and scanning electron microscopy. Control veins had a normal appearing endothelial lining, composed of elongated, attenuated endothelial cells. Veins irradiated with more than 24 mJ/cm2 displayed injured endothelial cells characterized by altered microvilli, defects in the cell surface, and a change in cell shape. The degree of cell damage correlated closely with increasing UVB dose. At doses of 80 mJ/cm2 or greater there was moderate to severe endothelial cell separation from the underlying basement membrane and an increase in cellular lysosomes. The effects of UVB were maximal at 3 days with virtual recovery in resurfacing of all specimens with endothelium 28 days after irradiation. These data suggest that UVB has a dose-dependent effect on venous endothelium that is morphologically reversible with time. Cell membrane changes seen following exposure to UVB may contribute to altered cell surface receptor function. 相似文献
3.
Human embryonic stem (ES) cells are pluripotent cells derived from blastocyst-stage embryos. It has been suggested that these cells should play a major role in transplantation medicine and be able to advance our knowledge in human embryology. We propose that these cells should also play a vital role in the creation of models of human disorders. This aspect would be most valuable where animal models failed to faithfully recapitulate the human phenotype. Lesch-Nyhan disease is caused by a mutation in the HPRT1 gene that triggers an overproduction of uric acid, causing gout-like symptoms and urinary stones, in addition to neurological disorders. Due to biochemical differences between humans and rodents, a mouse lacking the HPRT expression will fail to accumulate uric acid. In this research we demonstrate a model for Lesch-Nyhan disease by mutating the HPRT1 gene in human ES cells using homologous recombination. We have verified the mutation in the HPRT1 allele at the DNA and RNA levels. By using selection media, we show that HPRT1 activity is abolished in the mutant cells, and the HPRT1-cells show a higher rate of uric acid accumulation than the wild-type cells. Therefore, these cells recapitulate to some extent the characteristics of Lesch-Nyhan syndrome and can help researchers further investigate this genetic disease and analyze drugs that will prevent the onset of its symptoms. We therefore suggest that human diseases may be modeled using human ES cells. 相似文献
4.
S Schwarzbaum A Nissim I Alkalay M C Ghozi D G Schindler Y Bergman Z Eshhar 《European journal of immunology》1989,19(6):1015-1023
The generation of anti-IgE monoclonal antibodies has permitted the identification of various serological epitopes on the IgE molecule. The relationship of the sites on IgE recognized by such antibodies to the Fc epsilon receptor (Fc epsilon R) interaction site has been determined using cross-inhibition studies. However, interpretation of this type of experiment is limited by problems of steric hindrance. Thus, to accomplish precise mapping on the IgE molecule of the Fc epsilon R interaction site and the binding sites of various anti-IgE mAb, we employed site-directed mutagenesis of the IgE heavy chain gene. To this end we have constructed and expressed a recombinant murine constant epsilon heavy chain (C epsilon) gene bearing a (4-hydroxy-3-nitrophenyl)acetic acid (NP)-binding VH region. Several site-specific mutants in the C epsilon 3 and C epsilon 4 domains of this recombinant C epsilon gene were prepared and expressed by transfection into the light chain-producing J558L myeloma cell line. The resulting IgE antibodies were tested for binding to mast cells and to various anti-IgE mAb. The mutants produced include a proline to histidine point mutant at amino acid residue 404 in the C epsilon 3 domain, a mutant with a truncated C epsilon 4 domain, a mutant with a 45 amino acid deletion in the carboxy end of C epsilon 3, and a chimeric human C epsilon in which the human C epsilon 3 was replaced by the homologous mouse C epsilon 3 domain. These mutants have permitted the localization, to the C epsilon 3 domain, of the epitopes recognized by the 84.1C and 95.3 anti-IgE mAb. The 84.1C mAb recognizes a site on IgE which is identical or very close to the Fc epsilon R binding site, and 95.3 recognizes a site on IgE which is related, but not identical to the Fc epsilon R binding site. The antigenic determinant recognized by the 51.3 mAb, which is inefficient at blocking the IgE-Fc epsilon R interaction, has been mapped to the C epsilon 4 domain. When tested for binding to the Fc epsilon R on RBL-2H3 cells, the point mutant bound to the Fc epsilon R with twofold reduced affinity, while the C epsilon 3 deletion mutant and the mutant truncated in C epsilon 4 lost all receptor binding activity.(ABSTRACT TRUNCATED AT 400 WORDS) 相似文献
5.
The HIV-1 Vpr protein harbors a nuclear localization signal in its N-terminal domain. A peptide bearing this domain and which is designated VprN has been used as a target to screen a phage display single chain Fv (scFv) library. Here we report the isolation of anti-VprN scFv fragments from this library. The purified scFv fragments were able to bind the VprN peptide in an ELISA-based system and to inhibit VprN-mediated nuclear import in permeabilized as well as in intact microinjected cells. Furthermore, the anti-VprN scFv fragments recognized the full-length recombinant Vpr protein and inhibited its nuclear import. The same scFv fragments did not inhibit nuclear import mediated by the nuclear localization signal of the SV40 large T-antigen demonstrating a specific effect. The use of the described inhibitory anti-VprN scFv fragments to study nuclear import of viral karyophilic proteins and their therapeutic potential is discussed. 相似文献
6.
Ron Epelbaum Channa Shalitin Ruth Segal Clari Valansi Ida Arselan David Faraggi Michelle Leviov Menahem Ben-Shahar Nissim Haim 《Pathology oncology research : POR》1998,4(4):271-276
A novel serum 21 kDa haptoglobin-related protein (Hpr) was investigated in patients with malignant lymphoma, to evaluate its
correlation with clinical and histologic features at presentation and its possible role as a tumor marker for patient outcome.
One hundred fifty eight serum samples were taken from 88 patients with non-Hodgkin’s lymphoma (n=58) and Hodgkin’s disease
(n=30) at presentation and in the course of follow-up. Sera from 61 healthy volunteers served as normal controls. Serum Hpr
levels in the lymphoma patients (median 430xl03 u/ml, range 0-4000xl03) were significantly higher than in the control group (median 68xl03 u/ml, range 0-180xl03) (p=0.0001). Higher median Hpr values were detected in patients with advanced disease (p=0.013), “B” symptoms (p=0.029) and
in males (p=0.053). There was also a significant correlation between Hpr and erythrocyte sedimentation rate (p=0.028). Serial
determinations showed a significant decrease of the initial Hpr values obtained after treatment in 41 patients, 38 of whom
achieved complete remission. In the follow-up period additional Hpr measurements were taken from 17 patients. Three of them
eventually relapsed, and showed increased Hpr levels at the time of relapse. Hpr levels remained low in 11 of 14 patients
who maintained complete remission, and increased in three. In conclusion, serum Hpr is a new serum tumor marker of potential
use in the clinical setting of lymphoma.
This work is dedicated to the memory of Dr. Arie H. Bartal, a dedicated oncologist and friend. This work was supported by
Chemotech Thechnologies Ltd., by grant no. 3676 from the Chief Scientist’s Office of the Ministry of Health, Israel, and by
the Fund for Promotion of Research in the Technion. 相似文献
7.
Nissim Arbib Orly Sneh-Arbib Rony Chen Arnon Wiznitzer Rinat Gabbay-Benziv 《The journal of maternal-fetal & neonatal medicine》2017,30(18):2174-2178
Purpose: Maternal thyroid gland dysfunction may adversely affect pregnancy outcome. We aimed to examine the association between subclinical thyroid dysfunction, both hypothyroidism and hyperthyroidism, to adverse pregnancy outcome.Materials and methods: Retrospective cohort study of all women with an available first trimester thyroid function testing and known pregnancy outcome, categorized to subclinical hypothyroidism, or hyperthyroidism and evaluated for complication during gestation and delivery.Results: Four thousand five hundred and four women were included in the final analysis – 3231 were euthyroid, 73 (1.6%) were categorized as subclinical hyperthyroidism and 1200 (26.6%) had subclinical hypothyroidism. Low thyroid-stimulating hormone (TSH) levels, i.e. subclinical hyperthyroidism, correlates with higher rates of placental abruption and extremely low birth weight, below 1500?g. Also, the risk for preterm delivery prior to 34 gestational weeks is higher among women with subclinical hypothyroidism, with greater risk among those with a higher TSH level. (OR 1.81, 95% CI 1.0–3.28 for TSH 2.5–4.0 mIU/L and OR 2.33, 95% CI 1.11–4.42 for those with TSH?>?4 4.0 mIU/L).Conclusions: Subclinical hypothyroidism is associated with an increased risk for preterm delivery prior to 34 gestational weeks. Additionally, subclinical hyperthyroidism may also have a role in adverse pregnancy outcome – low birth weight and placental abruption – although this needs to be further explored. 相似文献
8.
Rinat Nissim Rebecca Wong Anthony Fyles Dhara Moddel Camilla Zimmermann Gary Rodin 《Practical radiation oncology》2012,2(4):e23-e29
PurposeClinic-based psychosocial interventions, including volunteer-based ones, may be a cost-efficient and acceptable means of integrating psychosocial support into cancer care during radiotherapy. The present study evaluated a new psychosocial volunteer support program in a large radiotherapy clinic.Methods and MaterialsPatients were asked to complete a demographic and satisfaction with care questionnaire. Clinic volunteers were asked to report their interactions with patients on shift logs.ResultsOf the 182 participating patients, 93 (51%) recalled meeting a volunteer in the clinic, with the 2 most common support types provided being the following: “listening and caring,” and “information on services.” Analysis of 224 volunteers' shift logs indicated that almost all interactions (94%) were initiated by the volunteers, and almost half (47%) involved the patients' companions in the clinic. The most common support type documented was “information and navigation” (71%), followed by “emotional” (47%), “diversional” (21%), and “physical/practical” (17%) support.ConclusionsTrained volunteers can effectively provide clinic-based psychosocial support and information to a high proportion of radiotherapy patients. These findings demonstrate that volunteer support is a feasible means of meeting the psychosocial needs of patients with cancer attending outpatient radiotherapy clinics, who may not require or want professional psychosocial support. 相似文献
9.
10.