全文获取类型
收费全文 | 2178篇 |
免费 | 108篇 |
国内免费 | 17篇 |
专业分类
耳鼻咽喉 | 28篇 |
儿科学 | 80篇 |
妇产科学 | 110篇 |
基础医学 | 363篇 |
口腔科学 | 70篇 |
临床医学 | 163篇 |
内科学 | 476篇 |
皮肤病学 | 41篇 |
神经病学 | 164篇 |
特种医学 | 49篇 |
外科学 | 124篇 |
综合类 | 10篇 |
一般理论 | 2篇 |
预防医学 | 151篇 |
眼科学 | 24篇 |
药学 | 181篇 |
中国医学 | 1篇 |
肿瘤学 | 266篇 |
出版年
2024年 | 2篇 |
2023年 | 9篇 |
2022年 | 28篇 |
2021年 | 63篇 |
2020年 | 41篇 |
2019年 | 56篇 |
2018年 | 61篇 |
2017年 | 49篇 |
2016年 | 63篇 |
2015年 | 64篇 |
2014年 | 84篇 |
2013年 | 123篇 |
2012年 | 199篇 |
2011年 | 210篇 |
2010年 | 89篇 |
2009年 | 102篇 |
2008年 | 153篇 |
2007年 | 166篇 |
2006年 | 137篇 |
2005年 | 143篇 |
2004年 | 101篇 |
2003年 | 76篇 |
2002年 | 92篇 |
2001年 | 28篇 |
2000年 | 19篇 |
1999年 | 18篇 |
1998年 | 14篇 |
1997年 | 9篇 |
1996年 | 9篇 |
1995年 | 7篇 |
1994年 | 5篇 |
1993年 | 4篇 |
1992年 | 17篇 |
1991年 | 7篇 |
1990年 | 10篇 |
1989年 | 4篇 |
1988年 | 3篇 |
1987年 | 5篇 |
1986年 | 3篇 |
1985年 | 6篇 |
1984年 | 4篇 |
1983年 | 2篇 |
1982年 | 4篇 |
1981年 | 2篇 |
1980年 | 3篇 |
1979年 | 3篇 |
1978年 | 3篇 |
1975年 | 2篇 |
1969年 | 1篇 |
排序方式: 共有2303条查询结果,搜索用时 15 毫秒
1.
Ewelina Kazimierczyk Andrzej Eljaszewicz Paula Zembko Ewa Tarasiuk Malgorzata Rusak Agnieszka Kulczynska-Przybik Marta Lukaszewicz-Zajac Karol Kaminski Barbara Mroczko Maciej Szmitkowski Milena Dabrowska Bozena Sobkowicz Marcin Moniuszko Agnieszka Tycinska 《Pharmacological reports : PR》2019,71(1):73-81
Background
Acute myocardial infarction (AMI) causes irreversible myocardial damage and release of inflammatory mediators, including cytokines, chemokines and miRNAs. We aimed to investigate changes in the levels of cytokines (IL-6, TNF-α and IL-10), miRNAs profiles (miR-146 and miR-155) and distribution of different monocyte subsets (CD14++CD16-, CD14++CD16+, CD14+CD16++) in the acute and post-healing phases of AMI.Methods
In eighteen consecutive AMI patients (mean age 56.78?±?12.4 years, mean left ventricle ejection fraction – LVEF: 41.9?±?9.8%), treated invasively, monocyte subsets frequencies were evaluated (flow cytometry), cytokine concentrations were analyzed (ELISA) as well as plasma miRNAs were isolated twice – on admission and after 19.2?±?5.9 weeks of follow-up. Measurements were also performed among healthy volunteers.Results
AMI patients presented significantly decreased frequencies of classical cells in comparison to healthy controls (median 71.22% [IQR: 64.4–79.04] vs. 84.35% [IQR: 81.2–86.7], p?=?0.001) and higher percent of both intermediate and non-classical cells, yet without statistical significance (median 6.54% [IQR: 5.14–16.64] vs. 5.87% [IQR: 4.48–8.6], p?=?0.37 and median 5.99% [IQR: 3.39–11.5] vs. 5.26% [IQR: 3.62–6.2], p?=?0.42, respectively). In AMI patients both, analyzed plasma miRNA concentrations were higher than in healthy subjects (miR-146: median 5.48 [IQR: 2.4–11.27] vs. 1.84 [IQR: 0.87–2.53], p?=?0.003; miR-155: median 25.35 [IQR: 8.17–43.15] vs. 8.4 [IQR: 0.08–16.9], p?=?0.027, respectively), and returned back to the values found in the control group in follow-up. miR-155/miR-146 ratio correlated with the frequencies of classical monocytes (r=0.6, p?=?0.01) and miR-155 correlated positively with the concentration of inflammatory cytokines ? IL-6 and TNF-α.Conclusions
These results may suggest cooperation of both pro-inflammatory and anti-inflammatory signals in AMI in order to promote appropriate healing of the infarcted myocardium. 相似文献2.
3.
Eileen J. Martin Kiran S. Panickar Michael A. King Malgorzata Deyrup Bruce E. Hunter Geehuan Wang Edwin M. Meyer 《Drug development research》1994,31(2):135-141
The potential cytoprotective actions of a novel nicotinic agent 2,4-dimethoxybenzilidene anabaseine (DMXB) were investigated in differentiated PC12 cells and transected rat septal cholinergic neurons in vivo. In NGF-differentiated PC12 cells, removal of both NGF and serum led to cell loss, a reduced % of cells expressing neurites, the release of lactate dehydrogenase, and a decrease in total cellular protein. Cell loss was apparent within 24 h, and remained constant between 4–8 days post-NGF removal. NGF alone (100 ng/ml), DMXB (10 μM), but not nicotine (10 μM), prevented these cell and neurite losses. DMXB-induced cytoprotection was blocked by 1 μM mecamylamine. DMXB (1 mg/kg, ip) injected twice but not once per day protected cholinesterase-staining septal neurons from retrograde degeneration following unilateral fimbrial transections. The twice per day DMXB injection-protocol also decreased cell roundness among cholinesterase-staining cells in the lesioned septal hemisphere compared to saline-injected animals. These studies suggest that DMXB may exert cytoprotective activity in NGF-sensitive neuronal populations. © 1994 Wiley-Liss, Inc. 相似文献
4.
Anna Plachcinska Jacek Kusmierek Maciej Kosmider Malgorzata Bienkiewicz Julian Liniecki 《European journal of nuclear medicine and molecular imaging》1995,22(3):193-200
A quantified evaluation of planar cardiac perfusion scintigrams (the objective of the study), obtained using technetium-99m methoxyisobutylisonitrile (MIBI) was performed on the basis of an analysis of circumferential profile curves, representing the perfusion as seen in three typical projections. The analysis involved the curves obtained both at rest and after stress, and was based on a comparison of their shape (trend) with the normal trend (normative evaluation). The latter was obtained by means of an original method of iterative fitting of individual curves into the database. The base consisted of curves recorded in 53 patients (separately in males and females) with normal perfusion of the left ventricle (group I, the reference group). A group of 90 patients suspected of having coronary artery disease (group II) was subdivided into two subgroups on the basis of coronary arteriography: (a) those with and (b) those without critical stenosis of at least one artery. Profile curves characterising the LV perfusion were obtained at rest and after stress. Defects of perfusion were quantified by comparison of individual curves with the normal trends. By means of multivariate analysis it was demonstrated that vectors of mean values characterising the scintigraphically assessed defects of LV perfusion in the two subgroups of group II differed very significantly (P<10–5). Applying methods of discriminant analysis, a classification of patients from group II was performed into those with probable defects of perfusion and those free of such defects. The sensitivity, specificity and accuracy of diagnosis of coronary ischaemia, based on quantified planar99mTc-MIBI scintigraphy, reached 86%, 87% and 87%, respectively. 相似文献
5.
6.
13C-NMR and the electron impact mass spectra of the β-carboline derivatives 1 – 18 were examined. The structure of the possible diastereomers is discussed. A quantitative relationship between the relative intensity of ions a in the mass spectra of 1 – 18 and the structure of substituents R was found. 相似文献
7.
8.
Summary: The present study was undertaken in the hope that conflicting opinions concerning interrelationships among minimal change disease (MCD), mesangial proliferative glomerulonephritis (MPG) and focal segmental glomeruloscierosis (FSGS) might be elucidated by morphometric methods performed by image analysis, as well as to study whether serum creatinine and changes in quantitatively analysed glomeruli could correlate with the interstitial fibrosis in these glomerulopathies. Fifteen renal biopsy specimens from children with MCD, 10 with primary MPG and 12 with FSGS for whom both light and electron microscopy as well as immunofluorescence microscopy and full clinical data were available, were examined quantitatively. As a control five biopsy and 10 autopsy specimens of the normal kidneys were used. Our quantitative study showed that in MCD, MPG and FSGS glomerular and interstitial values differed from normal. Morphometric differences between MPG and both MCD and FSGS groups were also shown. Although the mean values of total glomerular area and relative interstitial volume were increased in FSGS patients, in total glomerular cells per unit of glomerular area and mesangium (% of total glomerular area) were similar in both MCD and FSGS groups. In MPG strong positive correlations existed between interstitial volume and serum creatinine, interstitial volume and total glomerular cells per unit of glomerular area as well as between interstitial volume and glomerular mesangium (% of total glomerular area). In FSGS there was significant positive correlation between interstitial volume and serum creatinine. In the MCD group all correlations were weak and not significant. In conclusion, our morphometric studies suggest a close relationship between MCD and FSGS, and indicate that MPG is a separate morphologic entity in children. 相似文献
9.
Malgorzata Krajewska Walasek Anna Gutkowska Beata Bieliska Bozenna Goryluk-Kozakiewicz Ewa Popowska 《Clinical genetics》1998,54(1):60-64
We report on a case of Prader-Willi syndrome (PWS) with a true reciprocal unbalanced translocation, 45,XX,-15,der(11)t(11;15)pat. The proposita was diagnosed clinically as having severe PWS. Molecular studies revealed loss of the paternal methylation pattern at locus D15S63 and a deletion encompassing the loci from at least D15S10 to D15S97 of paternal chromosome 15. FISH studies confirmed the deletion of 15q11-q13 region and the presence of two telomeres on all chromosomes. The proposita's father, the father's sister and their mother are all carriers of the same balanced translocation t(11;15)(q25;q13). By genomic imprinting we would expect that if the father's sister were to give birth to a child with the same unbalanced translocation as the proband, it would be affected by Angelman syndrome.
To date, a similar familial unbalanced translocation due to loss of the small chromosome 15 derivative has not been described. 相似文献
To date, a similar familial unbalanced translocation due to loss of the small chromosome 15 derivative has not been described. 相似文献
10.
Carmina E.; Gentzschein E.; Stanczyk F.Z.; Lobo R.A. 《Human reproduction (Oxford, England)》1995,10(2):299-303
Serum C19 conjugates, specifically 3-androstanediol glucuronide(3G), reflect peripheral androgen action through the actionof 5-reductase activity. The origin of 5-reduced C19 conjugateshas been controversial and it has been suggested that they arederived primarily from adrenal androgens. We examined concentrationsof 3G, 3-androstanediol sulphate (3S), androsterone glucuronide(AoG) and androsterone sulphate (AoS) in 40 hirsute hyperandrogenicwomen. These patients were divided into four groups based uponindividual, combined or normal concentrations of the adrenalandrogens dehydroepiandrosterone (DHEAS) and 11-hydroxy-androstenedione.Testosterone, unbound testosterone and androstenedione weresimilar in these groups. Serum 3G was equally high in all groupsand was correlated significantly with hirsutism, while the otherconjugates were not. Androsterone glucuronide was raised inall groups but was higher in patients with raised DHEAS. Serum3S was raised in all groups and was higher where both adrenalandrogens were raised. Serum AoS was highly correlated withDHEAS. Serum 3G was correlated with unbound testosterone andandrostenedione but not with the adrenal androgens. The glucuronideconjugates were correlated with one another as were the sulphateconjugates but glucuronides and sulphates were not correlated.These data confirm ovarian and adrenal dependency of C19 conjugates.Serum 3G appears to reflect hirsutism most accurately and isleast dependent on adrenal androgens in patients with mixedhyperandrogenism. 相似文献