全文获取类型
收费全文 | 1306篇 |
免费 | 129篇 |
国内免费 | 17篇 |
专业分类
耳鼻咽喉 | 5篇 |
儿科学 | 85篇 |
妇产科学 | 34篇 |
基础医学 | 173篇 |
口腔科学 | 23篇 |
临床医学 | 133篇 |
内科学 | 236篇 |
皮肤病学 | 26篇 |
神经病学 | 113篇 |
特种医学 | 59篇 |
外科学 | 204篇 |
综合类 | 51篇 |
预防医学 | 165篇 |
眼科学 | 10篇 |
药学 | 83篇 |
中国医学 | 4篇 |
肿瘤学 | 48篇 |
出版年
2022年 | 6篇 |
2021年 | 20篇 |
2020年 | 7篇 |
2019年 | 19篇 |
2018年 | 24篇 |
2017年 | 31篇 |
2016年 | 18篇 |
2015年 | 34篇 |
2014年 | 44篇 |
2013年 | 44篇 |
2012年 | 77篇 |
2011年 | 46篇 |
2010年 | 40篇 |
2009年 | 54篇 |
2008年 | 52篇 |
2007年 | 59篇 |
2006年 | 47篇 |
2005年 | 62篇 |
2004年 | 31篇 |
2003年 | 33篇 |
2002年 | 40篇 |
2001年 | 57篇 |
2000年 | 51篇 |
1999年 | 37篇 |
1998年 | 45篇 |
1997年 | 41篇 |
1996年 | 21篇 |
1995年 | 30篇 |
1994年 | 23篇 |
1993年 | 26篇 |
1992年 | 25篇 |
1991年 | 22篇 |
1990年 | 15篇 |
1989年 | 25篇 |
1988年 | 12篇 |
1987年 | 19篇 |
1986年 | 18篇 |
1985年 | 18篇 |
1984年 | 12篇 |
1983年 | 13篇 |
1982年 | 12篇 |
1981年 | 14篇 |
1980年 | 9篇 |
1979年 | 9篇 |
1976年 | 8篇 |
1975年 | 6篇 |
1972年 | 8篇 |
1971年 | 8篇 |
1967年 | 9篇 |
1965年 | 7篇 |
排序方式: 共有1452条查询结果,搜索用时 15 毫秒
1.
2.
It has recently been suggested in the Health of the Nationthat specific accident prevention activities should be undertakenby general practitioners. This study reports the findings froma survey of general practitioners in Nottinghamshire assessingknowledge, attitudes and current practices in accident prevention.The findings suggest that more than two-thirds of respondinggeneral practitioners are aware of the extent of childhood mortalityfrom accidental injuries and of the risk factors for accidentalinjury. Knowledge scores were higher for women, those aged 44years and under, those on the child health surveillance list,those with experience of hospital or community paediatrics,and those with postgraduate qualifications in paediatrics. Morethan 50% of general practitioners hold positive views towardsthe activities suggested in the Health of the Nationand more than 40% are already carrying out such activities.Positive attitudes are more commonly held in women and thoseon the child health surveillance list. There was a significantcorrelation between knowledge score and attitude score. Forall accident prevention activities covered in the questionnaire,fewer practitioners undertook an activity than held a positiveattitude towards that activity. Accident prevention work iscurrently more likely to be undertaken by general practitionerson an opportunistic basis than on a systematic population basis.If general practitioner intervention is demonstrated to be effective,a shift towards a population approach may be more successfulin reducing injury rates. 相似文献
3.
Edward McNulty Joshua Cohen Tony Chou Kendrick Shunk 《Catheterization and cardiovascular interventions》2006,67(1):46-48
We present two patients with angulated, proximal left circumflex lesions, one a chronic total occlusion and one an acute subtotal occlusion. In both cases, use of the deflectable tip Venture Catheter (Velocimed, Minneapolis, MN) facilitated guide wire passage and successful percutaneous coronary intervention (PCI) after prior attempts at guide wire passage with standard wires were unsuccessful. 相似文献
4.
AP de Moraes† ÉÂG de Arruda† MAV Vitoriano† MO de Moraes Filho‡ FÂF Bezerra‡ E de Magalhães Holanda§ MEA de Moraes‡ 《Journal of the European Academy of Dermatology and Venereology》2007,21(5):596-601
BACKGROUND: Seborrhoeic dermatitis (SD) is a common dermatosis in human immunodeficiency virus (HIV)-positive patients, many of whom do not respond satisfactorily to conventional topical treatments such as corticosteroids and antifungals. OBJECTIVE: A pilot study to investigate the efficacy and tolerability of pimecrolimus cream 1% in HIV-positive patients with facial SD. METHODS: In a single-centre study, 21 HIV-infected patients with mild to severe SD were treated twice daily with pimecrolimus cream 1% for 14 days. Thereafter, treatment was discontinued and patients followed up for 5 weeks. Skin involvement at baseline and on days 7, 14, 21, 35 and 49 was assessed using a four-point clinical score and digital photography. MAIN OUTCOME MEASURES: Efficacy and safety of pimecrolimus cream 1% treatment and incidence of relapse in the follow-up phase. Results Marked improvement was seen in clinical parameters at day 7, with >or= 90% patients clear of symptoms at day 14. Relapse was observed at day 35 but signs were milder than at baseline. All patients responded to therapy, despite their immunological status. Pimecrolimus did not alter CD4(+) and CD8(+) T-cell counts or viral load during the treatment period. CONCLUSION: Pimecrolimus cream represents a new, effective therapeutic option for facial SD in HIV patients. 相似文献
5.
Outdoor advertising media represent a major vehicle by which cigarette companies promote their products. We investigated the readability of the Surgeon General's warning in cigarette advertisements (ads) in two outdoor media: billboards and taxicab ads. In an experiment in metropolitan Atlanta under typical driving conditions, observers were able to read the entire health warning on 18 (46%) of 39 street billboards but on only two (5%) of 39 highway billboards. In contrast, the content of the ads (ie, brand name, other wording, and notable imagery) could be recognized under the same conditions on more than 95% of the billboards. In a similar study of 100 taxicab cigarette ads in New York City, observers were unable to read the health warning in any of the ads but were able to identify the brand name in all ads and notable imagery in 95% of the ads. Significant differences between the readability of the warning and identification of the advertising content persisted even when partially read warnings were considered to have been read. We conclude that the Surgeon General's warning is not readable in its current form in the vast majority of billboard and taxicab ads. Factors contributing to unreadability include the small size of the letters, the excessive length of the warnings, the distance between the viewers and the ads, and movement between the viewers and the ads. 相似文献
6.
Injury prevention programmes in primary care: a high risk group or a whole population approach? 总被引:5,自引:1,他引:4
下载免费PDF全文
![点击此处可从《Injury prevention》网站下载免费的PDF全文](/ch/ext_images/free.gif)
OBJECTIVE: To examine the relationship between risk factors for childhood unintentional injury and injury outcome and to assess the feasibility of using risk factors to identify children at high risk of injury. SETTING: One general practice in Nottingham, UK. METHOD: A postal questionnaire survey to all parents of children registered with the practice (n = 771) to obtain data on risk and sociodemographic factors. All children still registered with the practice one year later were followed up for occurrence of a medically attended injury. RESULTS: The response rate was 78%. The injury rate over the follow up year was 246 injuries per 1000 children. Previous medically attended injury was associated with each of the injury outcomes (odds ratio (confidence interval) for all attendances, 2.33 (1.37 to 4.05); for accident and emergency attendances, 2.27 (1.15 to 4.4); and for primary health care team attendances, 2.58 (1.33 to 5.0)). Male sex was associated only with accident and emergency department attendance (odds ratio 2.13 (1.06 to 4.2)). Maternal age and previous injury were associated with a higher number of injuries in the subsequent year on univariate and multivariate analyses. The sensitivity and positive predictive value of the risk factors were low, except for previous injury and male sex. The number of children needing an injury prevention intervention to prevent one injury as identified by the risk factors was not significantly different from that required if a whole population approach were to be used. CONCLUSION: Primary care based injury prevention programmes, at present, should not be targeted at children identified as being at 'high risk' of injury. Nevertheless, a larger study using a wider cross section of the population is needed to address this issue further. 相似文献
7.
In-vitro maturation of human germinal vesicle stage oocytes: role of cumulus cells and epidermal growth factor in the culture medium 总被引:21,自引:6,他引:21
Goud PT; Goud AP; Qian C; Laverge H; Van der Elst J; De Sutter P; Dhont M 《Human reproduction (Oxford, England)》1998,13(6):1638-1644
In-vitro maturation (IVM) of oocytes is a promising technique to reduce the
costs and avert the side-effects of gonadotrophin stimulation for in-vitro
fertilization (IVF). The pregnancy rates from oocytes matured in vitro are
much lower than those of in-vivo stimulation cycles indicating that
optimization of IVM remains a challenge. Therefore, we investigated the
effect of supplementation of the medium with gonadotrophins, oestradiol and
epidermal growth factor (EGF) and the effect of retaining or removing the
cumulus cells on nuclear and cytoplasmic maturation of immature oocytes.
Human germinal vesicle (GV) oocytes obtained after gonadotrophin
stimulation for intracytoplasmic sperm injection (ICSI) were cultured in a
complex defined medium either supplemented with gonadotrophins, oestradiol
and physiological concentrations of EGF (2 ng/ml) or gonadotrophins and
oestradiol alone. The cumulus cells were either removed or kept intact. In
GV stage oocytes cultured without cumulus (group I) significantly more
oocytes reached the metaphase II (MII) stage at 30 h in media supplemented
with EGF (64.3 versus 33.9%, P < 0.003). For oocytes cultured with
intact cumulus (group II), more oocytes reached MII at 30 h than in group
I, but there was no difference in medium with or without EGF
supplementation (81.8 and 79.8% respectively). Cytoplasmic maturation of
MII oocytes was judged from their capability to activate and fertilize
after ICSI. In group I, the rates of activation and normal fertilization
were similar. However, in group II, significantly more oocytes underwent
normal fertilization in the EGF-supplemented than the unsupplemented group
(71.7 versus 45.6%, P < 0.05). The cleavage rates of the fertilized
oocytes were similar in the sibling oocyte subgroups cultured with or
without EGF supplementation, but the overall cleavage rates were higher in
cumulus-intact compared to cumulus-denuded oocytes (88.9 versus 47.8%, P
< 0.001). Thus, supplementation of the maturation medium with EGF and
maintenance of the cumulus during culture improve the nuclear and
cytoplasmic maturation of human oocytes in vitro.
相似文献
8.
The effects of co-culture with human fibroblasts on human embryo development in vitro and implantation 总被引:5,自引:0,他引:5
Wetzels AM; Bastiaans BA; Hendriks JC; Goverde HJ; Punt-van der Zalm AP; Verbeet JG; Braat DD 《Human reproduction (Oxford, England)》1998,13(5):1325-1330
In a human in-vitro fertilization (IVF) programme, the effect of co-
culture of embryos with human fibroblasts was evaluated with respect to
pregnancy rate and embryo development. Patients were included in the study
after giving informed written consent. The IVF treatments were randomly
assigned by stratification of both age (<36 versus > or =36 years)
and previous IVF attempts (yes versus no). After fertilization was
established, the zygotes were transferred to a 4-well dish with or without
fibroblasts and cultured for 2 days. On the third day after ovum pick-up
(OPU), cell number and quality [5 (good) to 1 (poor)] of the embryos were
scored and a maximum of three embryos was transferred. Supernumerary
embryos of good quality were cryopreserved. The design of this study was a
group sequential trial with the objective of detecting differences between
pregnancy rates following IVF with conventional incubation or incubation in
co-culture with fibroblasts. This design included one evaluation at
half-way data collection. In the study, 148 patients had an OPU, of whom 77
were allocated to the co-culture group. There was no statistically
significant difference in pregnancy rate, cell number and embryo quality
between the two groups. The ongoing pregnancy rate per embryo transfer was
27% in co-culture and 30% in the conventional culture group. The
implantation rates per transferred embryo were 17 and 18% respectively.
Using a multivariate logistic regression model for the probability of
ongoing pregnancies, the odds ratio of co-culture, adjusted for age and
previous IVF attempts, was not statistically significant. In conclusion,
co-culture with human fibroblasts does not contribute to an improvement of
embryo quality nor to a higher pregnancy rate after IVF in an unselected
group of patients.
相似文献
9.
The UTX gene escapes X inactivation in mice and humans 总被引:7,自引:3,他引:7
Greenfield A; Carrel L; Pennisi D; Philippe C; Quaderi N; Siggers P; Steiner K; Tam PP; Monaco AP; Willard HF; Koopman P 《Human molecular genetics》1998,7(4):737-742
We recently have identified a ubiquitously transcribed mouse Y chromosome
gene, Uty , which encodes a tetratricopeptide repeat (TPR) protein. A
peptide derived from the UTY protein confers H-Y antigenicity on male
cells. Here we report the characterization of a widely transcribed X-linked
homologue of Uty , called Utx , which maps to the proximal region of the
mouse X chromosome and which detects a human X-linked homologue at Xp11.2.
Given that Uty is ubiquitously transcribed, we assayed for Utx expression
from the inactive X chromosome (Xi) in mice and found that Utx escapes X
chromosome inactivation. Only Smcx and the pseudoautosomal Sts gene on the
mouse X chromosome have been reported previously to escape inactivation.
The human UTX gene was also found to be expressed from Xi. We discuss the
significance of these data for our understanding of dosage compensation of
X-Y homologous genes in humans and mice.
相似文献
10.
High throughput parallel analysis of hundreds of patient samples for more than 100 mutations in multiple disease genes 总被引:5,自引:0,他引:5
Shuber AP; Michalowsky LA; Nass GS; Skoletsky J; Hire LM; Kotsopoulos SK; Phipps MF; Barberio DM; Klinger KW 《Human molecular genetics》1997,6(3):337-347
As more mutations are identified in genes of known sequence, there is a
crucial need in the areas of medical genetics and genome analysis for
rapid, accurate and cost-effective methods of mutation detection. We have
developed a multiplex allele-specific diagnostic assay (MASDA) for analysis
of large numbers of samples (> 500) simultaneously for a large number of
known mutations (> 100) in a single assay. MASDA utilizes
oligonucleotide hybridization to interrogate DNA sequences. Multiplex DNA
samples are immobilized on a solid support and a single hybridization is
performed with a pool of allele-specific oligonucleotide (ASO) probes. Any
probes complementary to specific mutations present in a given sample are in
effect affinity purified from the pool by the target DNA. Sequence-specific
band patterns (fingerprints), generated by chemical or enzymatic sequencing
of the bound ASO(s), easily identify the specific mutation(s). Using this
design, in a single diagnostic assay, we tested samples for 66 cystic
fibrosis (CF) mutations, 14 beta-thalassemia mutations, two sickle cell
anemia (SCA) mutations, three Tay-Sachs mutations, eight Gaucher mutations,
four mutations in Canavan disease, four mutations in Fanconi anemia, and
five mutations in BRCA1. Each mutation was correctly identified. Finally,
in a blinded study of 106 of these mutations in > 500 patients, all
mutations were properly identified. There were no false positives or false
negatives. The MASDA assay is capable of detecting point mutations as well
as small insertion or deletion mutations. This technology is amenable to
automation and is suitable for immediate utilization for high-throughput
genetic diagnostics in clinical and research laboratories.
相似文献