全文获取类型
收费全文 | 700篇 |
免费 | 51篇 |
专业分类
儿科学 | 47篇 |
妇产科学 | 26篇 |
基础医学 | 100篇 |
口腔科学 | 5篇 |
临床医学 | 92篇 |
内科学 | 188篇 |
皮肤病学 | 24篇 |
神经病学 | 39篇 |
特种医学 | 10篇 |
外科学 | 61篇 |
综合类 | 1篇 |
预防医学 | 40篇 |
眼科学 | 8篇 |
药学 | 32篇 |
肿瘤学 | 78篇 |
出版年
2024年 | 2篇 |
2023年 | 9篇 |
2022年 | 7篇 |
2021年 | 25篇 |
2020年 | 18篇 |
2019年 | 17篇 |
2018年 | 23篇 |
2017年 | 19篇 |
2016年 | 20篇 |
2015年 | 17篇 |
2014年 | 24篇 |
2013年 | 35篇 |
2012年 | 43篇 |
2011年 | 46篇 |
2010年 | 39篇 |
2009年 | 27篇 |
2008年 | 41篇 |
2007年 | 50篇 |
2006年 | 37篇 |
2005年 | 28篇 |
2004年 | 43篇 |
2003年 | 41篇 |
2002年 | 30篇 |
2001年 | 4篇 |
2000年 | 2篇 |
1999年 | 7篇 |
1998年 | 10篇 |
1997年 | 9篇 |
1996年 | 12篇 |
1995年 | 4篇 |
1994年 | 10篇 |
1993年 | 4篇 |
1992年 | 3篇 |
1991年 | 1篇 |
1990年 | 4篇 |
1989年 | 3篇 |
1988年 | 5篇 |
1987年 | 3篇 |
1986年 | 3篇 |
1985年 | 5篇 |
1984年 | 3篇 |
1983年 | 3篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1978年 | 3篇 |
1973年 | 1篇 |
1964年 | 2篇 |
排序方式: 共有751条查询结果,搜索用时 15 毫秒
1.
Ariella Nouriel M.D. Jonah Zisquit M.D. Alexander M. Helfand M.D. Shoshana Greenberger M.D. Ph.D. 《Pediatric dermatology》2015,32(6):e245-e248
A 3‐year‐old Arab boy with a history of hypoplastic left heart syndrome was referred to the pediatric dermatology clinic at Sheba Medical Center for evaluation of hypomelanosis, manifested by fair skin pigmentation and silvery‐grey hair, eyebrows, and eyelashes. The child had one older brother with similar hypopigmentation and another older brother who had died of congenital heart disease. The child had no history of neurologic deficits or immunodeficiency and no additional findings on clinical evaluation. 相似文献
2.
This study proposes to examine the phenomenology of home among 46 Israeli adults who had been deemed "at-risk children" and removed from their home by court order in their childhood on the grounds of parental mistreatments, such as abuse and neglect. For a comprehensive understanding of the long-term impact of out-of-home placement, adults of different ages were interviewed. The research findings reflect the close connection between home concept and self-concept, a long-standing internal dialectic between the home that did not exist and the home (as an internal-emotional space) that the adults would have liked to have. Furthermore, our findings reveal what we term the life career of the home concept, that is, the various diachronic phenomenological definitions that adults grant to the home-self in childhood, anchored in the family home, during their time in a residential care setting, their adolescence, and their adulthood. The discussion addresses the unique self-concept and home concept of care leavers. 相似文献
3.
Switching yeast from meiosis to mitosis: double-strand break repair, recombination and synaptonemal complex 总被引:3,自引:0,他引:3
Drora Zenvirth Josef Loidl Shoshana Klein Ayelet Arbel Ronen Shemesh & Giora Simchen 《Genes to cells : devoted to molecular & cellular mechanisms》1997,2(8):487-498
Background:
When Saccharomyces cerevisiae cells that have begun meiosis are transferred to mitotic growth conditions (‘return-to-growth’, RTG), they can complete recombination at high meiotic frequencies, but undergo mitotic cell division and remain diploid. It was not known how meiotic recombination intermediates are repaired following RTG. Using molecular and cytological methods, we investigated whether the usual meiotic apparatus could repair meiotically induced DSBs during RTG, or whether other mechanisms are invoked when the developmental context changes.Results:
Upon RTG, the rapid disappearance of meiotic features—double-strand breaks in DNA (DSBs), synaptonemal complex (SC), and SC related structures—was striking. In wild-type diploids, the repair of meiotic DSBs during RTG was quick and efficient, resulting in homologous recombination. Kinetic analysis of double-strand breakage and recombination indicated that meiotic DSB formation precedes the commitment to meiotic levels of recombination. DSBs were repaired in RTG in dmc1, but not rad51 mutants, hence repair did not occur by the usual meiotic mechanism which requires the Dmc1 gene product. In haploids, DSBs were also repaired quickly and efficiently upon RTG, showing that DSB repair did not require the presence of a homologous chromosome. In all strains examined, SC and related structures were not required for DSB repair or recombination following RTG.Conclusions:
At least two pathways of DSB repair, which differ from the primary meiotic pathway(s), can occur during RTG: One involving interhomologue recombination, and another involving sister-chromatid exchange. DSB formation precedes commitment to recombination. SC elements appear to prevent sister chromatid exchange in meiosis.4.
Braverman N Chen L Lin P Obie C Steel G Douglas P Chakraborty PK Clarke JT Boneh A Moser A Moser H Valle D 《Human mutation》2002,20(4):284-297
PEX7 encodes the cytosolic receptor for the set of peroxisomal matrix enzymes targeted to the organelle by the peroxisome targeting signal 2 (PTS2). Mutations in PEX7 cause rhizomelic chondrodysplasia punctata (RCDP), a distinct peroxisome biogenesis disorder. In previous work we described three novel PEX7 mutant alleles, including one, L292X, with a high frequency due to a founder effect. We have now extended our analysis to 60 RCDP probands and identified a total of 24 PEX7 alleles, accounting for 95% of the mutant PEX7 genes in our sample. Of these, 50% are L292X, 13% are IVS9+1G>C, and the remainder are mostly private. IVS9+1G>C occurs on at least three different haplotypes and thus appears to result from recurrent mutation. The phenotypic spectrum of RCDP is broader than commonly recognized and includes minimally affected individuals at the mild end of the spectrum. To relate PEX7 genotype and phenotype, we evaluated the consequence of the disease mutation on PEX7 RNA by Northern analysis and RT/PCR. We evaluated the function of the encoded Pex7 protein (Pex7p) by expressing selected alleles in fibroblasts from RCDP patients and assaying their ability to restore import of a PTS2 marker protein. We find that residual activity of mutant Pex7p and reduced amounts of normal Pex7p are associated with milder and variant phenotypes. 相似文献
5.
Expression of human CD81 in transgenic mice does not confer susceptibility to hepatitis C virus infection 总被引:6,自引:0,他引:6
Masciopinto F Freer G Burgio VL Levy S Galli-Stampino L Bendinelli M Houghton M Abrignani S Uematsu Y 《Virology》2002,304(2):187-196
We previously demonstrated that hepatitis C virus (HCV) binds to human CD81 through the E2 glycoprotein. Therefore, expression of the human CD81 molecule in transgenic mice was expected to provide a new tool to study HCV infection in vivo, as the chimpanzee is the only species currently available as a laboratory animal model that can be infected with HCV. We produced transgenic mice expressing the human CD81 protein in a wide variety of tissues. We confirmed binding of recombinant E2 glycoprotein to the liver tissue as well as to thymocytes and splenic lymphocytes in the transgenic mice. We inoculated chimpanzee plasma infected with HCV into these animals. None of these transgenic animals showed evidence of viral replication. Furthermore, human CD81 transgenic mice that lack expression of endogenous mouse CD81 were also resistant to HCV infection. We conclude that expression of human CD81 alone is insufficient to confer susceptibility to HCV infection in the mouse. The presence of additional possible factors for HCV infection is discussed. 相似文献
6.
HLA and alopecia areata in Jerusalem 总被引:1,自引:0,他引:1
A study of 46 patients with Alopecia areata in Jerusalem showed a significant increase in the frequency of HLA-B18 (23.9%) as compared to the control population (7.4%) with a relative risk of 3.9%. This association of HLA-B18 with AA was independent of the origin of patients, sex, age of onset and type of alopecia areata. 相似文献
7.
Somatic Mutation in Human B-Cell Tumors 总被引:15,自引:0,他引:15
Ronald Levy Shoshana Levy Michael L. Cleary William Carroll Shinichiro Kon Jeffrey Bird Jeffrey Sklar 《Immunological reviews》1987,96(1):43-58
8.
Chaim Brautbar Marian Moscovitz Tatyana Livshits Salim Haim Shoshana Hacham-Zadeh Haim A. Cohen Rafi Sharon David Nelken Tirza Cohen 《Tissue antigens》1980,16(3):238-243
Pemphigus vulgaris (PV) is relatively common in Jews. Three HLA antigens were significantly more frequent in 39 Israeli Jewish PV patients than in controls: A26 – 59% vs 20%; Bw38 – 61% vs 20%; and DRw4 – 90% vs 38%. The joint occurrence of A26–Bw38–DRw4 was observed in 46% of PV patients and in 10% of controls. Similar results were recently reported for Jews in the Los Angeles area. Yet, when our patient sample was grouped into Ashkenazi and non-Ashkenazi Jews, it was evident that each of the three antigens had a higher frequency both in Ashkenazi patients and controls as compared to non-Ashkenazim. The relative risk for DRw4 in Ashkenazim was 33.8 as compared to 14.4 in the total sample of Israeli PV patients. The phenotype A26–Bw38–DRw4 was present in 57% of Ashkenazi patients and in 13% of controls. Ashkenazi Jews have the highest prevalence of PV, and HLA associations were strongest with Ashkenazi PV patients. These associations were with three antigens, all of high frequency in that group. 相似文献
9.
The mechanism of action of soluble lymphocytic mediators: I. A pulse exposure test for the measurement of macrophage migration inhibitory factor 总被引:2,自引:0,他引:2
下载免费PDF全文
![点击此处可从《Immunology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Culture supernatants containing macrophage migration inhibitory factor (MIF) were obtained by incubating lymphocytes of guinea-pigs, immunized with Freund's complete adjuvant (FCA), with tuberculin PPD in vitro. Exposure of normal peritoneal macrophages to MIF-containing supernatants for 2 hours at 37° (pulse exposure), followed by suspension in culture medium and transfer to capillaries, resulted in inhibition of migration in vitro for the next 24 hours. No inhibition was seen when macrophages were incubated with MIF at 4°. On the other hand when exposure to MIF at 4° was followed by incubation of the cells for 2 hours at 37° in culture medium, in the absence of MIF, inhibition of migration was obtained. These results indicate that: (a) macrophages possess a specific receptor able to bind MIF at either 4° or 37°, and (b) inhibition of migration by receptor bound MIF requires a temperature-dependent active process, the nature of which remains unknown.
Passage of lymphocytes through columns of glass beads resulted in a population of cells with intact or heightened MIF-forming ability, as assessed by both conventional and pulse exposure techniques.
相似文献10.
Treatment variables in relation to oocyte maturation: Lessons from a clinical micromanipulation-assisted in vitro fertilization program 总被引:1,自引:0,他引:1
Ori M. Avrech Gil A. Goldman Onit Rufas Anat Stein Shoshana Amit Israel Yoles Haim Pinkas Benjamin Fisch 《Journal of assisted reproduction and genetics》1997,14(6):337-342
Objective: In an effort to understand the mechanism underlying the improved pregnancy rate observed in IVF cycles when gonadotropin-releasing
hormone analogues (GnRH-a) are applied, we investigated a possible relationship between treatment variables and oocyte-nuclear
maturity.
Design: Nuclear maturity was retrospectively assessed in cumulus-free, denuded oocytes, obtained from women undergoing micromanipulation-assisted
IVF treatment following controlled ovarian hyperstimulation with GnRH-a and menotropins.
Setting: The setting was the infertility and IVF unit of a tertiary academic medical center.
Participants: Two hundred twenty-one patients underwent 435 treatment cycles.
Main Outcome Measure: This was the proportion of germinal vesicle-intact immature (GVII) oocytes.
Results: One hundred fifty-four of the 3520 oocytes studied (4.4%) were in the GVII stage. These oocytes were found in 66 of the treatment
cycles (15.2%) and in 54 of the patients (24.4%). Cycles in which GVII oocytes were detected did not differ from those in
which all the aspirated oocytes were mature in the following respects: patient age, type and duration of infertility, controlled
ovarian hyperstimulation protocol and time of ovum pickup. However, the GVII group was characterized by a significantly higher
peak estradiol level, as well as a higher number of mature follicles visualized sonographically (diameter, >14 mm) and oocytes
retrieved.
Conclusions: Comparing the present findings with previously published data, it appears that the inclusion of GnRH-a in the stimulation
regimen is associated with a lower proportion of immature oocytes. A higher occurrence of oocyte-nuclear immaturity is apparently
associated with a significantly better ovarian response to stimulation. The high incidence of immature oocytes observed in
patients with normospermic partners and low fertilization rates in previous cycles may suggest that the fertilization failure
in some of these cases is due to oocyte, rather than sperm, dysfunction. 相似文献