全文获取类型
收费全文 | 1145篇 |
免费 | 76篇 |
国内免费 | 47篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 44篇 |
妇产科学 | 5篇 |
基础医学 | 121篇 |
口腔科学 | 22篇 |
临床医学 | 138篇 |
内科学 | 285篇 |
皮肤病学 | 26篇 |
神经病学 | 48篇 |
特种医学 | 151篇 |
外科学 | 99篇 |
综合类 | 31篇 |
预防医学 | 60篇 |
眼科学 | 6篇 |
药学 | 102篇 |
中国医学 | 83篇 |
肿瘤学 | 41篇 |
出版年
2021年 | 10篇 |
2020年 | 5篇 |
2019年 | 4篇 |
2018年 | 7篇 |
2017年 | 9篇 |
2016年 | 7篇 |
2015年 | 23篇 |
2014年 | 22篇 |
2013年 | 40篇 |
2012年 | 23篇 |
2011年 | 29篇 |
2010年 | 37篇 |
2009年 | 33篇 |
2008年 | 23篇 |
2007年 | 63篇 |
2006年 | 31篇 |
2005年 | 22篇 |
2004年 | 33篇 |
2003年 | 21篇 |
2002年 | 41篇 |
2001年 | 34篇 |
2000年 | 21篇 |
1999年 | 28篇 |
1998年 | 46篇 |
1997年 | 54篇 |
1996年 | 58篇 |
1995年 | 39篇 |
1994年 | 37篇 |
1993年 | 21篇 |
1992年 | 26篇 |
1991年 | 28篇 |
1990年 | 24篇 |
1989年 | 46篇 |
1988年 | 50篇 |
1987年 | 33篇 |
1986年 | 31篇 |
1985年 | 33篇 |
1984年 | 29篇 |
1983年 | 15篇 |
1982年 | 23篇 |
1981年 | 18篇 |
1980年 | 15篇 |
1979年 | 9篇 |
1978年 | 7篇 |
1977年 | 5篇 |
1976年 | 13篇 |
1975年 | 11篇 |
1974年 | 5篇 |
1968年 | 4篇 |
1967年 | 4篇 |
排序方式: 共有1268条查询结果,搜索用时 15 毫秒
1.
HJ Aubin S Tilikete C Laureaux HT Nguyen Hac MC Roullet-Volmi S Troupel D Barrucand 《European psychiatry》1995,10(8)
The aim of this study was to assess alcoholic inpatients' smoking and coffee intake variation following withdrawal. Only moderate smokers (less than 30 cigarettes/day) showed a significant increase of cigarette consumption after alcohol withdrawal. However, their urinary cotinine level did not vary, suggesting a behavioral, and not biological, compensation through smoking following alcohol withdrawal. Heavy smokers (30 cigarettes/day or more) showed no significant clinical or biological variation of smoking behavior. Coffee consumption increased after alcohol withdrawal in all patients, irrespective of smoking habits. 相似文献
2.
Active and passive surveillance for communicable diseases in child care facilities, Seattle-King County, Washington. 下载免费PDF全文
J K MacDonald J Boase L K Stewart E R Alexander S L Solomon R L Cordell 《American journal of public health》1997,87(12):1951-1955
OBJECTIVES: The purpose of this study was to develop and evaluate models for public health surveillance of illnesses among children in out-of-home child care facilities. METHODS: Between July 1992 and March 1994, 200 Seattle-King County child care facilities participated in active or enhanced passive surveillance, or both. Reporting was based on easily recognized signs, symptoms, and sentinel events. Published criteria were used in evaluating surveillance effectiveness, and notifiable disease reporting of participating and nonparticipating facilities was compared. RESULTS: Neither surveillance model was well accepted by child care providers. Enhanced passive and active surveillance had comparable sensitivity. Reporting delays and the large amount of time needed for data entry led to problems with timeliness, especially in terms of written reporting during active surveillance. CONCLUSIONS: Widespread active public health surveillance in child care facilities is not feasible for most local health departments. Improvements in public health surveillance in child care settings will depend on acceptability to providers. 相似文献
3.
BACKGROUND: A simple, rapid, inexpensive method for measuring the flow in a
patient's vascular access would permit routine monitoring during
haemodialysis, and hence provide information of access graft deterioration
sufficiently early to increase the success of minimally invasive remedial
procedures. This paper reports the validation of such a method in animals.
METHODS: A PTFE graft was implanted in sheep between the carotid artery and
the jugular vein. While the sheep was under general anaesthesia and on an
haemodialysis circuit, ultrasound velocity in its blood was perturbed by
the injection of a 5-10 ml bolus of isotonic NaCl. The pump tubing flow was
measured by a transit-time blood flow meter. This flow was combined with
the areas of perturbation generated by the injection before and after
mixing in the access flow to estimate graft flow. The calculated graft flow
was compared to flow measured directly by a transit-time probe on the same
carotid artery. RESULTS: Over a 10-fold range, 120-1260 ml/min, graft flow
measured by ultrasound velocity dilution agreed well with graft flow
measured directly with a scatter of 76 ml/min about the regression line.
CONCLUSION: Ultrasound velocity dilution provides a method for measuring
flow in the graft accurate enough for clinical evaluation of patients on
dialysis.
相似文献
4.
5.
M Kaplan HJ Vreman C Hammerman C Leiter B Rudensky MG MacDonald DK Stevenson 《Acta paediatrica (Oslo, Norway : 1992)》1998,87(4):455-457
The incidence (%) of hyperbilirubinemia (serum bilirubin ≥257 μmol/l) was similar in neonates with a combination of ABO incompatibility and glucose-6-phosphate dehydrogenase (G-6-PD) deficiency (45%), with ABO incompatibility (54%) or G-6-PD deficiency (37%), alone (ns). Carboxyhemoglobin values, corrected for inspired CO, were similarly elevated in all three groups (0.87 ± 0.32%, 0.82 ± 0.29%, 0.76 ± 0.18%, respectively, ns), but correlated with bilirubin only in those with ABO incompatibility alone. ABO-incompatible/G-6-PD-deficient neonates, compared with those with either condition alone, are not at increased risk for hemolysis or hyperbilirubinemia. 相似文献
6.
7.
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.
Endothelin receptor expression in human decidua 总被引:3,自引:1,他引:3
Kohnen G; Campbell S; Irvine GA; Church HJ; MacLachlan F; Titterington M; Cameron IT 《Molecular human reproduction》1998,4(2):185-193
The endothelins are signalling peptides that act via two receptors, ET(A)
and ET(B). In the human endometrium, endothelin receptors have been
demonstrated in glands and stroma and have been shown to vary during the
course of the menstrual cycle. The present study was undertaken to
determine whether or not expression of endothelin receptors changes during
pregnancy or after administration of exogenous progestagens. The expression
of the receptors was correlated with the appearance of basement membrane
components during decidualization of the endometrial stroma. Decidual
specimens (n = 15) were obtained during the first trimester of pregnancy
and 10 at term. Sixteen pairs of endometrial biopsies were obtained from
women with menorrhagia before and after exposure to exogenous progestagens.
A total of 15 hysterectomy specimens were used as controls for the
expression of stromal basement membrane proteins in the absence of
decidualization. Autoradiography was carried out with selective ligands for
ET(A) ([125I]-PD 151242) and ET(B) ([125I]-BQ3020). The distribution of
ligand binding was then compared with the distribution of laminin alpha2
light chain and collagen IV. ET(A), ET(B), laminin alpha2 light chain, and
collagen IV were expressed in stromal decidual cells in the first trimester
of pregnancy. ET(B) was also found on endometrial glandular epithelium.
Quantitative macro-autoradiography and multiple regression analysis
demonstrated a highly significant positive correlation (P < 0.001)
between expression of ET(B) and laminin alpha2 light chain. In the third
trimester qualitative examination suggested a reduction of ET(A) in the
stroma. Progestagen-induced decidua exhibited a similar pattern to that
found in first trimester decidua. This study has demonstrated up-regulation
of ET(B) during the progesterone- dependent process of decidualization and
suggests a paracrine or autocrine role for endothelins in the decidua.
相似文献
10.
D. Y. Mason W. M. Comans-Bitter J. L. Cordell M. A. Verhoeven J. J. van Dongen 《The American journal of pathology》1990,136(6):1215-1222
Monoclonal antibody L26 is a highly selective marker of B cells and B-cell neoplasms in paraffin-embedded tissues, but it suffers from the drawback that the target molecule has not been identified. In this paper we provide evidence by two independent techniques that antibody L26 recognizes an intracellular epitope on the CD20 antigen (a pan B-cell marker). When this antigen was redistributed on the surface of unfixed viable B cells by incubation with monoclonal anti-CD20 followed by anti-mouse Ig, the diffuse cytoplasmic staining of L26 was abolished and replaced by coincident dotlike labeling for antibody L26 and the CD20 antigen. None of the other antibodies tested (covering 10 different B-cell-associated antigens) had this effect on the L26 staining pattern. Furthermore, COS-1 cells transfected with cDNA encoding the CD20 molecule gave positive staining with antibody L26 and with two other CD20 reagents, but not with antibodies to other pan B-cell markers (eg, CD19 and CD22). 相似文献