全文获取类型
收费全文 | 3121篇 |
免费 | 207篇 |
国内免费 | 27篇 |
学科分类
医药卫生 | 3355篇 |
出版年
2024年 | 7篇 |
2023年 | 68篇 |
2022年 | 112篇 |
2021年 | 188篇 |
2020年 | 123篇 |
2019年 | 160篇 |
2018年 | 145篇 |
2017年 | 95篇 |
2016年 | 125篇 |
2015年 | 134篇 |
2014年 | 163篇 |
2013年 | 209篇 |
2012年 | 294篇 |
2011年 | 246篇 |
2010年 | 150篇 |
2009年 | 113篇 |
2008年 | 168篇 |
2007年 | 170篇 |
2006年 | 127篇 |
2005年 | 124篇 |
2004年 | 100篇 |
2003年 | 83篇 |
2002年 | 79篇 |
2001年 | 18篇 |
2000年 | 10篇 |
1999年 | 14篇 |
1998年 | 16篇 |
1997年 | 6篇 |
1996年 | 2篇 |
1995年 | 4篇 |
1994年 | 11篇 |
1993年 | 6篇 |
1992年 | 12篇 |
1991年 | 10篇 |
1990年 | 8篇 |
1989年 | 4篇 |
1988年 | 6篇 |
1987年 | 7篇 |
1986年 | 5篇 |
1985年 | 5篇 |
1983年 | 2篇 |
1982年 | 4篇 |
1981年 | 2篇 |
1979年 | 3篇 |
1978年 | 3篇 |
1977年 | 2篇 |
1975年 | 2篇 |
1974年 | 6篇 |
1971年 | 1篇 |
1965年 | 1篇 |
排序方式: 共有3355条查询结果,搜索用时 0 毫秒
1.
Gazzaniga P. P. Ferroni P. Mina C. Pulcinelli F. M. Rizzo P. A. 《The Italian Journal of Neurological Sciences》1987,8(6):561-566
148 patients with various forms of cerebrovascular disease (CVD) were studied by means of a multiparametric analysis ofin vitro platelet aggregation, based on the following six parameters: ADP and epinephrine primary and secondary aggregation thresholds
and percent maximum aggregation induced by optimal concentrations of ADP and epinephrine. These patients were assigned to
four study groups, according to clinical diagnosis supported by CT scan, of transient ischemic attack and reversible neurological
deficit (TIA-RIND), or completed stroke, in the presence or absence respectively of antiplatelet medical treatment at the
time of the study. A statistically significant increase of thein vitro platelet aggregation was found in 44.4% of the untreated TIA-RIND patients and in 33.9% of the untreated stroke patients.
However this last group showed a higher percentage of very marked hyperaggregation. Differences between the two treated study
groups and controls were not signicant. No difference was found in collagen-and ristocetin-induced aggregation between the
patient groups and the controls.
Sommario 148 pazienti con varie forme di malattia cerebrovascolare, sono stati studiati con analisi multiparametriche dell'aggregazione piastrinica in vitro sulla base dei seguenti sei parametri: le soglie di aggregazione primaria e secondaria e l'aggregazione massima percentuale indotta da ADP ed Epinefrina. Questi pazienti sono stati suddivisi in 4 gruppi di studio in accordo con la diagnosi clinica confortata dai dati della TAC e cioè: TIA, RIND, o rammollimento in presenza o in assenza rispettivamente di un trattamento antiaggregante nel momento dello studio. è stato trovato un aumento statisticamente significativo dell'aggregazione in vitro delle piastrine nel 44.4% dei casi TIA, RIND non trattati e nel 33,9% dei casi di rammollimento non trattati. Quest'ultimo gruppo, però, ha dimostrato una più alta percentuale di iperaggregazione molto marcata. Le differenze tra i 2 gruppi di studio trattati con antiaggreganti e i controlli non erano significative. Inoltre nessuna differenza è stata riscontrata tra i gruppi e i controlli nell'aggregazione indotta da collageno e ristocetina.相似文献
2.
Paolo Cossu Rocca Matteo Brunelli Stefano Gobbo Albino Eccher Emma Bragantini Maria M Mina Vincenzo Ficarra Filiberto Zattoni Alberto Zamò Maurizio Pea Aldo Scarpa Marco Chilosi Fabio Menestrina Franco Bonetti John N Eble Guido Martignoni 《Modern pathology》2007,20(7):722-728
S100A1 is a calcium-binding protein, which has been recently found in renal cell neoplasms. We evaluated the diagnostic utility of immunohistochemical detection of S100A1 in 164 renal cell neoplasms. Forty-one clear cell, 32 papillary, and 51 chromophobe renal cell carcinomas, and 40 oncocytomas, 164 samples of normal renal parenchyma adjacent to the tumors and 13 fetal kidneys were analyzed. The levels of S100A1 mRNA detected by quantitative RT-PCR analysis of frozen tissues from seven clear cell, five papillary, and six chromophobe renal cell carcinomas, four oncocytomas, and nine samples of normal renal tissues adjacent to neoplasms were compared with the immunohistochemical detection of protein expression. Clear cell and papillary renal cell carcinomas showed positive reactions for S100A1 in 30 out of 41 tumors (73%) and in 30 out of 32 (94%) tumors, respectively. Thirty-seven renal oncocytomas out of 40 (93%) were positive for S100A1, whereas 48 of 51 (94%) chromophobe renal cell carcinomas were negative. S100A1 protein was detected in all samples of unaffected and fetal kidneys. S100A1 mRNA was detected by RT-PCR in all normal kidneys and renal cell neoplasms, although at very different levels. Statistical analyses comparing the different expression of S100A1 in clear cell and chromophobe renal cell carcinomas observed by immunohistochemical and RT-PCR methods showed significant values (P<0.001), such as when comparing by both techniques the different levels of S100A1 expression in chromophobe renal cell carcinomas and oncocytomas (P<0.001). Our study shows that S100A1 protein is expressed in oncocytomas, clear cell and papillary renal cell carcinomas but not in chromophobe renal cell carcinomas. Its immunodetection is potentially useful for the differential diagnosis between chromophobe renal cell carcinoma and oncocytoma. Further, S100A1 protein expression is constantly detected in the normal parenchyma of the adult and fetal kidney. 相似文献
3.
4.
Alikani Mina; Noyes Nicole; Cohen Jacques; Rosenwaks Zev 《Human reproduction (Oxford, England)》1994,9(7):1318-1321
Six cases of identical twin pregnancies which occurred in 2163cycles of in-vitro fertilization during a 3 year period arereported. Monozygosity was confirmed when the number of fetusesexceeded the number of embryos replaced (n = 4) or when twoconcepti were observed in a single amniotic sac (n = 2). Eachof the reported pregnancies resulted from replacement of embryoseither with naturally thin zonae pellucida or embryos whosezonae had been breached during micromanipulation for assistedfertilization (subzonal sperminsertion) or assisted hatching.That such cases exclusively gave rise to monozygosity suggestsa link between the physical state of the zona pellucida, hatching,and generation of identical twins. 相似文献
5.
6.
Worldwide genomic diversity of the human papillomaviruses-53, 56, and 66, a group of high-risk HPVs unrelated to HPV-16 and HPV-18 总被引:3,自引:0,他引:3
Prado JC Calleja-Macias IE Bernard HU Kalantari M Macay SA Allan B Williamson AL Chung LP Collins RJ Zuna RE Dunn ST Ortiz-Lopez R Barrera-Saldaña HA Cubie HA Cuschieri K von Knebel-Doeberitz M Sanchez GI Bosch FX Villa LL 《Virology》2005,340(1):95-104
Among more than 200 human papillomavirus (HPV) types presumed to exist, 18 "high-risk" HPV types are frequently found in anogenital cancer. The best studied types are HPV-16 and 18, which are only distantly related to one another and form two separate phylogenetic branches, each including six closely related types. HPV-30, 53, 56, and 66 form a third phylogenetic branch unrelated to HPV-16 and 18. Worldwide comparison of HPV-16 and 18 isolates revealed a distribution of variant genomes that correlated with the geographic origin and the ethnicity of the infected cohort and led to the concept of unique African, European, Asian, and Native American HPV-16 and 18 variants. Here, we address the question whether similar phylogenies are found for HPV-53, 56, and 66 by determining the sequence of the long control regions (LCR) of these HPVs in samples from Europe, Asia, and Africa, and from immigrant societies in North and South America. Phylogenetic trees calculated from point mutations and a few insertions/deletions affecting 2-4.2% of the nucleotide sequences were distinct for each of the three HPVs and divergent from HPV-16 and 18. In contrast to the "star-phylogenies" formed by HPV-16 and 18 variants, 44 HPV-53 isolates represented nine variants, which formed two deep dichotomic branches reminiscent of the beginning split into two new taxa, as recently observed for subtypes of HPV-44 and 68. A total of 66 HPV-56 isolates represented 17 variants, which formed three branches preferentially containing European, Asian, and African variants. Variants of a fourth branch, deeply separated from the other three, were characterized by a 25 bp insertion and created a dichotomy rather than star-like phylogeny. As it contained isolates from cohorts in all continents, it may have evolved before the spread of humans into all continents. 18 of 31 HPV-66 isolates represented the prototype clone, which was found in all parts of the world, while the remaining 13 clones formed 11 branches without any geographic association. Our findings confirm the notion of a quantitatively limited genomic diversity of each HPV type with some correlation to the geographic origin of the sample. In addition, we observed in some variants of these three HPV types mutations that affect the amino acid sequence of the E6 oncoproteins and the L1 capsid protein, supporting the possibility of immunogenic and oncogenic diversity between variants of any HPV type. 相似文献
7.
Maria Shahmoradgoli Najafabadi Mina Ohadi Mohammad Taghi Joghataie Faraz Valaie Yasser Riazalhosseini Hamid Mostafavi Fariba Mohammadbeigi Hossein Najmabadi 《American journal of medical genetics. Part B, Neuropsychiatric genetics》2005,(1):39-41
Dysfunction of the central dopaminergic neurotransmission has been suggested to play an important role in the etiology of certain neuropsychiatric disorders such as drug abuse. It has been shown that the dopamine D2 receptor (DRD2) gene dysfunction is associated with multi-drug addiction. Addiction to opium is the most common form of drug abuse in Iran. We studied the allelic association between DRD2 Taq I A polymorphism in 100 opium-dependent Iranian patients and 130 unrelated controls. A 310 bp (base pair) region surrounding Taq I site at the DRD2 locus was amplified by polymerase chain reaction (PCR) and the PCR product was incubated with Taq I restriction enzyme. The A1 allele remained intact while the A2 allele was cut. Significant association was observed between A1 allele and addiction in the patients group (P < 0.0001). Moreover, the frequency of A1A1 genotype was significantly higher in opium users than controls (P < 0.0001). Our result indicates that DRD2 might be involved in the pathophysiology of opium addiction. 相似文献
8.
Objective To investigate the association between the-258T/G polymorphism.in the pro-moter of parkin gene and the risk for sporadic parkinson's disease (SPD) in Guangxi Province, and in relationto the age of onset, of PD patients. Methods PCR-RFLP and sequence analysis were used to determine thegenotype of-258T/G polymorphism between all patients and healthy controls. Results The G allele was morecommon in patients than controls (55.20%:43.33% ,x2=6.898, P<0.05, OR=1.61, 95% CI: 1.13 ~2.30). The frequency of GG genotype was higher in patients than in controls (28.00 %: 18.33%, x2=7.159, P<0.05, OR=2.75, 95% CI : 1.31 ~ 5.77). The frequency of TG + GG genotype was higher in pa-tients than in controls (82.40%:68.33%, x2=6.551, P<0.05, OR=2.17.95%CI: 1.20 ~3.93). Afterbeing stratified by onset age, the frequencies of the G allele and GG genotype were significantly higher in pa-tients with onset age over 50 years than those in controls respectively. On the other hand, the frequency was notsignificantly different between the younger onset PD patients and the controls. Conclusion The parkin promot-er-258T/G polymorphism might be a risk factor for PD in Guangxi Province, and the G allele was increasedwith increasing age. 相似文献
9.
10.
David Cohen Jacques Michel Mina Ferne Sonya Bergner-Rabinowitz Isaac Ginsburg 《Inflammation》1979,3(4):395-403
Leukocyte extracts, trypsin, and lysozyme are all capable of releasing the bulk of the LPS from S. typhi, S. typhimurium, and E. coli. Bacteria which have been killed by heat, ultraviolet irradiation, or by a variety of metabolic inhibitors and antibiotics which affect protein, DNA, RNA, and cell wall synthesis no longer yield soluble LPS following treatment with the releasing agents. On the other hand, bacteria which are resistant to certain of the antibiotics yield nearly the full amount of soluble LPS following treatment, suggesting that certain heatlabile endogenous metabolic pathways collaborate with the releasing agents in the release of LPS from the bacteria. It is suggested that some of the beneficial effects of antibiotics on infections with gram-negative bacteria may be the prevention of massive release of endotoxin by leukocyte enzymes in inflammatory sites. 相似文献