全文获取类型
收费全文 | 5912篇 |
免费 | 305篇 |
国内免费 | 17篇 |
专业分类
耳鼻咽喉 | 34篇 |
儿科学 | 150篇 |
妇产科学 | 95篇 |
基础医学 | 787篇 |
口腔科学 | 294篇 |
临床医学 | 466篇 |
内科学 | 1224篇 |
皮肤病学 | 93篇 |
神经病学 | 477篇 |
特种医学 | 232篇 |
外科学 | 933篇 |
综合类 | 40篇 |
一般理论 | 5篇 |
预防医学 | 408篇 |
眼科学 | 99篇 |
药学 | 465篇 |
中国医学 | 3篇 |
肿瘤学 | 429篇 |
出版年
2022年 | 43篇 |
2021年 | 86篇 |
2020年 | 70篇 |
2019年 | 92篇 |
2018年 | 103篇 |
2017年 | 109篇 |
2016年 | 121篇 |
2015年 | 107篇 |
2014年 | 194篇 |
2013年 | 296篇 |
2012年 | 380篇 |
2011年 | 377篇 |
2010年 | 219篇 |
2009年 | 224篇 |
2008年 | 342篇 |
2007年 | 332篇 |
2006年 | 360篇 |
2005年 | 341篇 |
2004年 | 306篇 |
2003年 | 316篇 |
2002年 | 307篇 |
2001年 | 43篇 |
2000年 | 37篇 |
1999年 | 54篇 |
1998年 | 74篇 |
1997年 | 72篇 |
1996年 | 67篇 |
1995年 | 63篇 |
1994年 | 55篇 |
1993年 | 52篇 |
1992年 | 43篇 |
1991年 | 40篇 |
1990年 | 46篇 |
1989年 | 39篇 |
1988年 | 51篇 |
1987年 | 31篇 |
1986年 | 30篇 |
1985年 | 46篇 |
1984年 | 41篇 |
1983年 | 39篇 |
1982年 | 48篇 |
1981年 | 35篇 |
1980年 | 37篇 |
1979年 | 33篇 |
1978年 | 40篇 |
1977年 | 33篇 |
1975年 | 31篇 |
1974年 | 21篇 |
1973年 | 30篇 |
1972年 | 21篇 |
排序方式: 共有6234条查询结果,搜索用时 15 毫秒
21.
Does the nature of the solvent affect the anti-inflammatory capacity of triclosan? An experimental study 总被引:4,自引:0,他引:4
Anne B. Skaare Vibeke Kjærheim Pål Barkvoll Gunnar Rölla 《Journal of clinical periodontology》1997,24(2):124-128
Abstract The anti-inflammatory properties of triclosan have been revealed in several recent studies, including an effect on histamine-induced inflammation. In other studies, the nature of the solvent has been shown to be of importance for the plaque inhibiting as well as the antibacterial potential of triclosan. This study was aimed at examining whether the nature of the solvent also may influence the anti-inflammatory capacity of triclosan and further to study a possible dose/response relationship. The study was performed as 3 separate, double-blind experiments, comprising 10, 11 and 12 healthy females. In all 3 experiments, 5 sites on the lower part of the back of the volunteers were intradermally exposed to one drop of 1% histamine dihydrochloride for 15 min. The size of the resulting wheals was recorded before and after 40 min of triclosan treatment. In experiment I. 4 different concentrations of triclosan in 2-fold dilutions in absolute alcohol (0.125%-1%) were applied on the histamine-induced wheals. In experiments 2 and 3, 4 different solutions containing 0.5% triclosan and a saline solution as negative control were used. The solvents in experiment 2 were as follows: (1) absolute alcohol (positive control). (2) propylene glycol (PG), (3) polyethylene glycol (PEG). (4) olive oil, and in experiment 3: (1) absolute alcohol (positive control). (2) Tween 80. (3) sodium carbonate, (4) soy oil. The results showed a dose/ response effect of triclosan and further that the solvent may be of importance for its anti-inflammatory potential. 相似文献
22.
23.
The aim of the study was to compare salivary variables in a group of vegetarians with a group of omnivores. Twenty-nine vegetarians, 19 women and 10 men, mean age 35 yr, and 28 omnivores, 20 women and 8 men, mean age 35 yr, were compared in terms of salivary secretion rate, pH, buffer capacity, mutans streptococci and lactobacilli. The vegetarians had a significantly higher secretion rate, but there were no other significant differences regarding the salivary variables. The difference in secretion rate may have been caused by some lifestyle factor(s) differing between vegetarians and omnivores which probably mainly include nutrient(s), texture and roughness of the food. 相似文献
24.
We examined 4 shoulder muscles-the supraspina-tus, infraspinatus, the middle portion of the deltoid and the descending part of the trapezius-with electromyography (EMG) in abducted and flexed arm positions, in 9 healthy subjects. the subjects were asked to produce a static handgrip force of 30% and 50% of maximal voluntary contraction (MVC) in 8 different arm positions. in all positions, the subjects held a dynamometer in the hand. the myoelectric activity in the shoulder muscles with only the dynamometer in the hand was compared to the EMG activity when static contractions were added. There was an association between static handgrip and shoulder muscle activity, as revealed by EMG. the EMG activity increased in the supraspinatus muscle in humeral flexion from and above 60° and in 120° abduction. in the infraspinatus muscle, the changes were less; a significant increase, however, was noticed in flexion. in the deltoid muscle there was a tendency towards increased activity in positions lower than 90°, in the higher arm positions, the activity decreased. There was no significant alteration regarding the EMG activity of the trapezius.
Our findings imply that high static handgrip force, particularly in elevated arm positions, increases the load on some shoulder muscles. the stabilizing muscles (the rotator cuff) were more influenced than the motor muscles by hand activity. Handgrip activity is important to evaluate while assessing shoulder load in manual work and in clinical evaluations of patients with shoulder pain. 相似文献
Our findings imply that high static handgrip force, particularly in elevated arm positions, increases the load on some shoulder muscles. the stabilizing muscles (the rotator cuff) were more influenced than the motor muscles by hand activity. Handgrip activity is important to evaluate while assessing shoulder load in manual work and in clinical evaluations of patients with shoulder pain. 相似文献
25.
Klaus-Dietmar Merboldt Gunnar Krüger Wolfgang Hnicke Andreas Kleinschmidt Jens Frahm 《Magnetic resonance in medicine》1995,34(4):639-644
Functional mapping of human brain activation has been accomplished at high spatial and temporal resolution (voxel size 4.9 μl, temporal increment 100 ms). The approach was based on oxygenation-sensitive long-echo time FLASH MRI sequences synchronized to multiply repeated cycles of visual stimulation in a CINE acquisition mode. This high temporal resolution revealed that stimulus-related signal intensity changes in human visual cortex display an initial latency followed by increases extending over several seconds. Furthermore, the temporal characteristics of the complete CINE MRI signal time course depended on the absolute and relative durations of activation and control periods and, for example, caused an apparent absence of a poststimulation “undershoot” phenomenon. Complementing hyperoxygenation due to rapid hemodynamic adjustments, these results suggest signal intensity modulation by enhanced oxygen consumption and concomitant deoxygenation during prolonged and/or repetitive stimulation. 相似文献
26.
Jan Frisell Gunnar Eklund Lars Hellström Ulla Glas Anders Somell 《Breast cancer research and treatment》1989,13(1):79-87
In screening programmes it is important to assess a preliminary effectiveness of the screening method as soon as possible in order to forecast survival figures. In March 1981 a controlled single-view mammographic screening trial for breast cancer was started in the south of Stockholm. The population invited for screening mammography consisted of 40,000 women aged 40–64 years, and 20,000 women served as a well-defined control group. The main aim of the trial was to determine whether repeated mammographic screening could reduce the mortality in the study population (SP) compared to the control population (CP).The cumulative number of advanced mammary carcinomas in the screening and the control populations from the first five years of screening have shown a tendency towards more favourable stages in the screened population aged 40–64 years. A breakdown by age suggests an effect in age group 50–59 years, but not yet in age groups 40–49 and 60–64 years.When comparing the rates of stage II+ cancer, an increased number is found in the study group. As the total rate of breast cancer is higher in SP than in CP, there ought to be a concealed group of stage II+ cancers in the CP which makes the comparison biased. A new approach has been designed, where an estimation of the hidden number of stage II+ cancers in CP is added to the clinically detected cases, and in this respect a comparison has shown a decrease in the cumulative number of advanced cancers in the SP in relation to the CP (p<0.05). According to this it could be important to add the estimated number of undetected, hidden cases in the control group in order to utilize the difference in detection rate in the screening- and control group respectively. 相似文献
27.
Intranasal immunization of mice with group B streptococcal protein rib and cholera toxin B subunit confers protection against lethal infection 总被引:3,自引:0,他引:3 下载免费PDF全文
Intranasal immunization of mice with Rib, a cell surface protein of group B streptococcus (GBS), conjugated to or simply coadministered with the recombinant cholera toxin B subunit, induces systemic immunoglobulin G (IgG) and local IgA antibody responses and confers protection against lethal GBS infection. These findings have implications for the development of a human GBS vaccine. 相似文献
28.
Thierbach R Schulz TJ Isken F Voigt A Mietzner B Drewes G von Kleist-Retzow JC Wiesner RJ Magnuson MA Puccio H Pfeiffer AF Steinberg P Ristow M 《Human molecular genetics》2005,14(24):3857-3864
We have disrupted expression of the mitochondrial Friedreich ataxia protein frataxin specifically in murine hepatocytes to generate mice with impaired mitochondrial function and decreased oxidative phosphorylation. These animals have a reduced life span and develop multiple hepatic tumors. Livers also show increased oxidative stress, impaired respiration and reduced ATP levels paralleled by reduced activity of iron-sulfur cluster (Fe/S) containing proteins (ISP), which all leads to increased hepatocyte turnover by promoting both apoptosis and proliferation. Accordingly, phosphorylation of the stress-inducible p38 MAP kinase was found to be specifically impaired following disruption of frataxin. Taken together, these findings indicate that frataxin may act as a mitochondrial tumor suppressor protein in mammals. 相似文献
29.
Genome profiles of bilateral dysgerminomas, a unilateral gonadoblastoma, and a metastasis from a 46, XY phenotypic female 总被引:3,自引:0,他引:3
Kildal W Kraggerud SM Abeler VM Heim S Tropé CG Kristensen GB Risberg B Lothe RA Danielsen HE 《Human pathology》2003,34(9):946-949
We present a case report of a 16-year-old, phenotypic female with bilateral dysgerminomas, a unilateral gonadoblastoma, and a peritoneal metastasis. The patient's constitutional karyotype was 46,XY. The chromosomal copy number, examined by the comparative genomic hybridization technique, showed 3 gains in the dysgerminoma of the right ovary, 6 gains in the dysgerminoma of the left ovary, and 2 gains and 1 loss in the gonadoblastoma of the left ovary. The metastasis showed 5 gains of which 4 were also observed in the dysgerminoma of the left ovary. The DNA ploidy classifications of the gonadoblastoma and the dysgerminoma in the right ovary were tetraploid, whereas the dysgerminoma in the left ovary and the metastasis were aneuploid. We therefore propose that the metastasis most probably developed from the dysgerminoma of the left ovary. 相似文献
30.
Comparison of serum hepatitis C virus RNA and core antigen concentrations and determination of whether levels are associated with liver histology or affected by specimen storage time 下载免费PDF全文
Lagging LM Garcia CE Westin J Wejstål R Norkrans G Dhillon AP Lindh M 《Journal of clinical microbiology》2002,40(11):4224-4229
An enzyme immunoassay has recently been developed for the hepatitis C virus (HCV) core antigen. To evaluate the possible association between core antigen and HCV RNA levels with regards to the change in liver histology over time as well as study the effect of duration of storage on viral load results, sequential sera were analyzed from 45 patients with chronic HCV infection who had undergone two or more liver biopsies. A relatively strong association was found between the core antigen and HCV RNA concentrations (r(s) = 0.8), with a core antigen level of 1 pg/ml corresponding to approximately 1,000 IU/ml. All 42 sera with detectable HCV RNA at the time of the second biopsy had core antigen concentrations above 1 pg/ml, and the three sera without detectable HCV RNA had concentrations below 1 pg/ml. No association was found between HCV RNA or core antigen levels and the stage of fibrosis in biopsy samples, progression of fibrosis, necro-inflammatory grade, steatosis, genotype, alanine aminotransferase level, or alcohol consumption. A significant association was demonstrated between the storage time of the samples and both the HCV RNA and core antigen concentrations. The median log HCV RNA concentrations (international units/milliliter) were 3.92 for the sera obtained at the time of the first biopsy (median storage time, 13.0 years) and 4.41 for the sera obtained at the time of the second biopsy (median storage time, 6.6 years) compared to 5.96, the median for 102 different routine clinical patient samples. 相似文献