全文获取类型
收费全文 | 432篇 |
免费 | 34篇 |
国内免费 | 13篇 |
学科分类
医药卫生 | 479篇 |
出版年
2022年 | 3篇 |
2021年 | 8篇 |
2019年 | 3篇 |
2018年 | 3篇 |
2016年 | 7篇 |
2015年 | 7篇 |
2014年 | 13篇 |
2013年 | 13篇 |
2012年 | 6篇 |
2011年 | 14篇 |
2010年 | 7篇 |
2009年 | 13篇 |
2008年 | 7篇 |
2007年 | 16篇 |
2006年 | 9篇 |
2005年 | 11篇 |
2004年 | 4篇 |
2003年 | 13篇 |
2002年 | 4篇 |
2001年 | 4篇 |
2000年 | 7篇 |
1999年 | 16篇 |
1998年 | 25篇 |
1997年 | 21篇 |
1996年 | 26篇 |
1995年 | 24篇 |
1994年 | 15篇 |
1993年 | 11篇 |
1992年 | 11篇 |
1991年 | 6篇 |
1990年 | 6篇 |
1989年 | 16篇 |
1988年 | 13篇 |
1987年 | 13篇 |
1986年 | 12篇 |
1985年 | 14篇 |
1984年 | 3篇 |
1983年 | 5篇 |
1982年 | 4篇 |
1980年 | 5篇 |
1979年 | 5篇 |
1977年 | 5篇 |
1976年 | 4篇 |
1975年 | 5篇 |
1973年 | 5篇 |
1972年 | 3篇 |
1971年 | 5篇 |
1969年 | 3篇 |
1968年 | 9篇 |
1964年 | 2篇 |
排序方式: 共有479条查询结果,搜索用时 171 毫秒
1.
2.
Testing for HIV is a procedure with possible dire consequences; hence, reports should not be rendered to the patient without appropriate counseling. And this must be based on firm information whether the individual is truly infected if the report is positive. The reactive results of the EIA screening test should always be confirmed by supplemental testing. However, it must be remembered that a nonreactive serum does not exclude the possibility of the individual being infected; only by additional research studies, such as the polymerase chain reaction, can one be sure that the patient is not in the phase in which antibodies have not yet developed but the virus is present and the patient can transmit the infection. Our studies have found that the accuracy of testing HIV serum specimens is excellent. The biggest problem may be the potential confusion caused by the laboratory reports. All clinicians (nurses, educators, and physicians) who counsel or test potential HIV patients must be sure that they understand their laboratory's report. If there is any doubt about the report content, it must be clarified by contacting the laboratory director. The results of HIV antibody testing are so important to the patient that the significance of the report must be crystal clear to the counselor and any possible ambiguity clarified. 相似文献
3.
A comparative study of the cytostatic drugs prospidin and cyclophosphamide used in equal doses for rheumatoid arthritis (RA) is reported. Clinical and immunologic effects were determined, and the nature and incidence of side effects and complications were compared. Prospidin showed a more pronounced antirheumatic effect, making for a smaller daily requirement of nonsteroid anti-inflammatory agents or hormones in hormone-dependent cases. Unlike cyclophosphamide, prospidin was not associated with severe side effects and complications precluding further use of the drug. Both drugs demonstrated a regulatory effect on RA-associated immunologic disorders. 相似文献
4.
5.
We conducted a pilot study of potential sources of incorrect laboratory reports of human immunodeficiency virus type 1 testing using blind proficiency testing. Sets of three serum samples, including one serum sample with negative reactions in antibody tests, one serum sample with positive reactions, and one that gave false-positive results with certain testing kits, were sent as routine patient specimens to testing laboratories. Half the laboratories reported the serum sample positive for human immunodeficiency virus antibodies as "indeterminate"; one laboratory rendered a final positive report without supplemental testing. On the report forms, the actual laboratory results were often obscured and intermingled with information, sometimes incorrect, such as identifying the agent as "HTLV-III" (human T-cell lymphotropic virus type III) and advising that a test with positive results is evidence of exposure to the virus. Many of these reports have the potential to confuse, rather than to enlighten, the requesting physician. 相似文献
6.
Human ovarian granulosa cells and follicular fluid indices: the relationship to oocyte maturity and fertilization in vitro 总被引:1,自引:0,他引:1
The study investigates the correlation between oocyte maturity and
fertilization and a variety of hormonal parameters in follicular fluid and
ovarian granulosa cells. A methodology for purification of granulosa cells
from contaminating blood cells is also established. A total of 63
follicular aspirates were collected at oocyte retrieval from 30 women
superovulated using the long luteinizing hormone- releasing hormone (LHRH
analogue)/human menopausal gonadotrophin regimen. Oestradiol, progesterone,
testosterone and human chorionic gonadotrophin (HCG) were quantified in
follicular fluid and granulosa cells were immunostained for human chorionic
gonadotrophin. Immunopurification of granulosa cells from contaminating
blood cells was performed. HCG in follicular fluid was significantly high
in follicles yielding immature (grade 3) oocytes (P=0.002); there was no
correlation with fertilization. Aspirates from follicles containing mature
(grade 1) oocytes and oocytes that subsequently fertilized had
significantly more granulosa cells immunobound to HCG (P < 0.001,
P=0.02). Moreover, the immunomagnetic purification technique provided
>98% pure population of granulosa cells. The data demonstrate that HCG
in follicular fluid and on granulosa cells may help to predict oocyte
maturity and fertilization. Furthermore, immunomagnetic beads provide a
reliable procedure for the purification of ovarian granulosa cells.
相似文献
7.
Burwinkel B; Maichele AJ; Aagenaes O; Bakker HD; Lerner A; Shin YS; Strachan JA; Kilimann MW 《Human molecular genetics》1997,6(7):1109-1115
Glycogen storage disease due to phosphorylase kinase deficiency occurs in
several variants that differ in mode of inheritance and tissue-
specificity. This heterogeneity is suspected to be largely due to mutations
affecting different subunits and isoforms of phosphorylase kinase. The gene
of the ubiquitously expressed beta subunit, PHKB, was a candidate for
involvement in autosomally transmitted phosphorylase kinase deficiency of
liver and muscle. To identify such mutations, the complete PHKB coding
sequence was amplified by RT-PCR of RNA isolated from blood samples of
patients and analyzed by direct sequencing of PCR products. The
characterization of mutations was complemented by PCR of genomic DNA. In
one female and four male patients, we identified five independent nonsense
mutations (Y418ter; R428ter; Y974H+E975ter; Q656ter in two cases), one
single-base insertion in codon N421, one splice-site mutation affecting
exon 31, and a large deletion involving the loss of exon 8. Although these
severe translation-disrupting mutations occur in constitutively expressed
sequences of the only known beta subunit gene of phosphorylase kinase,
PHKB, they are associated with a surprisingly mild clinical phenotype,
affecting virtually only the liver, and relatively high residual enzyme
activity of approximately 10%.
相似文献
8.
Delivery of a hammerhead ribozyme specifically down-regulates the production of fibrillin-1 by cultured dermal fibroblasts 总被引:4,自引:1,他引:4
Kilpatrick MW; Phylactou LA; Godfrey M; Wu CH; Wu GY; Tsipouras P 《Human molecular genetics》1996,5(12):1939-1944
The hammerhead ribozyme is a small catalytic RNA molecule. Potential
hammerhead ribozymes that possess a catalytic domain and flanking sequence
complementary to a target mRNA can cleave in trans at a putative cleavage
site within the target molecule. We have investigated the potential of
hammerhead ribozymes to down-regulate the product of the fibrillin-1 gene
(FBN1). Fibrillin is a 347 kDa glycoprotein that is a major constituent of
the elastin-associated microfibrils. Mutations in the FBN1 gene are
responsible for Marfan syndrome (MFS), a common systemic disorder of the
connective tissue. Many FBN1 mutations responsible for MFS appear to act in
a dominant-negative fashion, raising the possibility that reduction of the
amount of product from the mutant FBN1 allele might be a valid therapeutic
approach for MFS. A trans-acting hammerhead ribozyme (FBN1-RZ1) targeted to
the 5' end of the human FBN1 mRNA has been designed and synthesized, and
shown to cleave its target efficiently in vitro. FBN1-RZ1 cleavage is
magnesium dependent and efficient at both 37 and 50 degrees C. Delivery of
the FBN1-RZ1 ribozyme into cultured dermal fibroblasts, by receptor-
mediated endocytosis of a ribozyme-transferrin-polylysine complex,
specifically reduces both cellular FBN1 mRNA and the deposition of
fibrillin in the extracellular matrix. These results suggest that the use
of hammerhead ribozymes is a valid approach to the study of fibrillin gene
expression and possibly to the development of a therapeutic approach to
MFS.
相似文献
9.
A. Rottenstreich S. Benenson G. Levin G. Kleinstern A.E. Moses S. Amit 《Clinical microbiology and infection》2019,25(2):251.e1-251.e4
Objectives
To investigate the incidence, risk factors, clinical course and outcomes of pregnancy-related group A streptococcus (GAS) infection.Methods
A retrospective 13-year cohort study of culture-proven pregnancy-related GAS infection was performed at two university hospitals serving heterogeneous, multicultural, urban and rural populations.Results
Of 124 women diagnosed with pregnancy-related GAS infection, 115 (93%) were in the puerperium, an incidence of 0.8 cases per 1000 live births (95% confidence interval, 0.7–0.9). A multivariate analysis showed primiparity and cesarean delivery to be independent protective factors against puerperal GAS infection (adjusted odds ratios (95% confidence interval), 0.60 (0.38, 0.97) and 0.44 (0.23, 0.81), respectively). Of the nine remaining patients, eight were diagnosed after first trimester abortions and one had an infected ectopic pregnancy. Among the entire cohort (n = 124), the predominant manifestations were fever and abdominal tenderness. Twenty-eight patients (23%) had severe GAS infections. All were treated with β-lactams, and most (n = 104, 84%) received clindamycin. Only four (3%) required surgical intervention; the rest fully recovered with conservative medical treatment including antibiotics. No recurrences, maternal deaths or neonatal complications were noted.Conclusions
Pregnancy-related GAS infection is not rare; it lacks specific signs and still carries significant morbidity. Primiparity, a presumable surrogate for diminished exposure to children and thus less GAS carriage, and cesarean delivery in which perioperative antibiotic prophylaxis was uniformly provided, appear as protective factors against puerperal GAS infection. This hints to the importance of community-acquired GAS and may support shifting efforts from infection-control–oriented nosocomial investigations to screening and prevention–driven policies. 相似文献10.
Cary-Blair, a transport medium for Vibrio parahemolyticus 总被引:2,自引:0,他引:2