全文获取类型
收费全文 | 303篇 |
免费 | 15篇 |
专业分类
318篇 |
出版年
2024年 | 1篇 |
2023年 | 1篇 |
2022年 | 2篇 |
2021年 | 5篇 |
2020年 | 3篇 |
2019年 | 6篇 |
2017年 | 2篇 |
2016年 | 15篇 |
2015年 | 16篇 |
2014年 | 14篇 |
2013年 | 12篇 |
2012年 | 15篇 |
2011年 | 23篇 |
2010年 | 15篇 |
2009年 | 9篇 |
2008年 | 32篇 |
2007年 | 23篇 |
2006年 | 29篇 |
2005年 | 27篇 |
2004年 | 16篇 |
2003年 | 23篇 |
2002年 | 12篇 |
2001年 | 4篇 |
1999年 | 5篇 |
1998年 | 1篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1992年 | 2篇 |
1989年 | 1篇 |
1988年 | 1篇 |
排序方式: 共有318条查询结果,搜索用时 15 毫秒
11.
12.
Characterization of ciprofloxacin binding to the linear single- and double-stranded DNA 总被引:1,自引:0,他引:1
The binding of ciprofloxacin to natural and synthetic polymeric DNAs was investigated at different solvent conditions using a combination of spectroscopic and hydrodynamic techniques. In 10 mM cacodylate buffer (pH 7.0) containing 108.6 mM Na(+), no sequence preferences in the interaction of ciprofloxacin with DNA was detected, while in 2 mM cacodylate buffer (pH 7.0) containing only 1.7 mM Na(+), a significant binding of ciprofloxacin to natural and synthetic linear double-stranded DNA was observed. At low ionic strength of solution, ciprofloxacin binding to DNA duplex containing alternating AT base pairs is accompanied by the largest enhancement in thermal stability (e.g. DeltaT(m) approximately 10 degrees C for poly[d(AT)].poly[d(AT)]), and the most pronounced red shift in the position of the maximum of the fluorescence emission spectrum (lambda(max)). Similar red shift in the position of lambda(max) is also observed for ciprofloxacin binding to dodecameric duplex containing five successive alternating AT base pairs in the row. On the other hand, ciprofloxacin binding to poly[d(GC)].poly[d(GC)], calf thymus DNA and dodecameric duplex containing a mixed sequence is accompanied by the largest fluorescence intensity quenching. Addition of NaCl does not completely displace ciprofloxacin bound to DNA, indicating the binding is not entirely electrostatic in origin. The intrinsic viscosity data suggest some degree of ciprofloxacin intercalation into duplex. 相似文献
13.
Salemi S Aeschlimann A Reisch N Jüngel A Gay RE Heppner FL Michel BA Gay S Sprott H 《Biochemical and biophysical research communications》2005,338(2):1012-1017
Opioid receptors (OR) are widely expressed in the central nervous system (CNS). Opioid antinociception might be initiated by activation of OR outside the CNS, indicating targeting of peripheral OR could be useful in the treatment of chronic pain. This study was designed to detect OR in skin tissues of healthy volunteers at both mRNA and protein levels. Skin samples from 10 healthy individuals were investigated. Total isolated RNAs were reverse transcribed, amplified and quantified by real-time PCR. Tissue and skin fibroblast OR protein was detected by immunohistochemistry, Western blot, and immunofluorescence. All skin tissue samples expressed delta- (DOR) and kappa-OR (KOR) mRNAs. Using immunohistochemistry, DOR and KOR were localized in skin fibroblast-like and mononuclear cells. Skin fibroblasts in culture expressed DOR and KOR mRNA. Using immunofluorescence, both DOR and KOR proteins were expressed predominantly on the cell membrane with minor staining in the cytoplasm. We suggest that enhanced expression of DOR and KOR in skin justifies the exploration of selective novel delta and kappa agonists for local pain treatment. 相似文献
14.
Stankovic M Nikolic A Divac A Tomovic A Petrovic-Stanojevic N Andjelic M Dopudja-Pantic V Surlan M Vujicic I Ponomarev D Mitic-Milikic M Kusic J Radojkovic D 《Genetic testing》2008,12(3):357-362
Chronic obstructive pulmonary disease (COPD) is a complex disease influenced by genetic and environmental factors. Cystic fibrosis transmembrane conductance regulator (CFTR) protein is an important component of the lung tissue homeostasis, involved in the regulation of the rate of mucociliary clearance. As it is known that certain CFTR variants have consequences on the function of CFTR protein, the aim of this study was to examine the possible role of F508del, M470V, Tn locus, and R75Q variants in COPD development and modulation. Total number of 86 COPD patients and 102 control subjects were included in the study. Possible association between COPD susceptibility, severity, and onset of the disease and allele or genotype of four analyzed CFTR variants was examined. No associations were detected between COPD development, onset of the disease and tested CFTR alleles and genotypes. However, VV470 genotype was associated with mild/moderate COPD stages in comparison to severe/very severe ones (OR = 0.29, 95%CI = 0.11-0.80, p = 0.016). Our study showed that patients with VV470 genotype had a 3.4-fold decreased risk for the appearance of severe/very severe COPD symptoms, and the obtained results indicate that this genotype may have a protective role. These results also suggest the importance of studying CFTR gene as a modifier of this disease. 相似文献
15.
Ablation of PGC-1beta results in defective mitochondrial activity, thermogenesis, hepatic function, and cardiac performance 下载免费PDF全文
Lelliott CJ Medina-Gomez G Petrovic N Kis A Feldmann HM Bjursell M Parker N Curtis K Campbell M Hu P Zhang D Litwin SE Zaha VG Fountain KT Boudina S Jimenez-Linan M Blount M Lopez M Meirhaeghe A Bohlooly-Y M Storlien L Strömstedt M Snaith M Oresic M Abel ED Cannon B Vidal-Puig A 《PLoS biology》2006,4(11):e369
16.
Thorsten Klampfl Jelena D. Milosevic Ana Puda Andreas Sch?negger Klaudia Bagienski Tiina Berg Ashot S. Harutyunyan Bettina Gisslinger Elisa Rumi Luca Malcovati Daniela Pietra Chiara Elena Matteo Giovanni Della Porta Lisa Pieri Paola Guglielmelli Christoph Bock Michael Doubek Dana Dvorakova Nada Suvajdzic Dragica Tomin Natasa Tosic Zdenek Racil Michael Steurer Sonja Pavlovic Alessandro M. Vannucchi Mario Cazzola Heinz Gisslinger Robert Kralovics 《PloS one》2013,8(10)
Exome sequencing of primary tumors identifies complex somatic mutation patterns. Assignment of relevance of individual somatic mutations is difficult and poses the next challenge for interpretation of next generation sequencing data. Here we present an approach how exome sequencing in combination with SNP microarray data may identify targets of chromosomal aberrations in myeloid malignancies. The rationale of this approach is that hotspots of chromosomal aberrations might also harbor point mutations in the target genes of deletions, gains or uniparental disomies (UPDs). Chromosome 11 is a frequent target of lesions in myeloid malignancies. Therefore, we studied chromosome 11 in a total of 813 samples from 773 individual patients with different myeloid malignancies by SNP microarrays and complemented the data with exome sequencing in selected cases exhibiting chromosome 11 defects. We found gains, losses and UPDs of chromosome 11 in 52 of the 813 samples (6.4%). Chromosome 11q UPDs frequently associated with mutations of CBL. In one patient the 11qUPD amplified somatic mutations in both CBL and the DNA repair gene DDB1. A duplication within MLL exon 3 was detected in another patient with 11qUPD. We identified several common deleted regions (CDR) on chromosome 11. One of the CDRs associated with de novo acute myeloid leukemia (P=0.013). One patient with a deletion at the LMO2 locus harbored an additional point mutation on the other allele indicating that LMO2 might be a tumor suppressor frequently targeted by 11p deletions. Our chromosome-centered analysis indicates that chromosome 11 contains a number of tumor suppressor genes and that the role of this chromosome in myeloid malignancies is more complex than previously recognized. 相似文献
17.
Secondary chronic open-angle glaucoma associated with pseudoexfoliation (PEX) syndrome accounts for approximately 25% of all glaucomas and represents the most common identifiable cause of glaucoma overall. Selective laser trabeculoplasty (SLT) is effective in reducing intraocular pressure (IOP) in glaucomatous patients and has the advantage of preserving surrounding structures. We report here SLT treatment of a 82 year old female with a secondary developed open-angle pseudoexfoliation glaucoma allergic to all anti glaucoma eye drops especially those which contain bensalconium chloridum as preservative. Since patient was allergic also to methyl-cellulose, we performed SLT with water as a mediator. Patient had PEX syndrome for 10 years, immature cataracts on both eyes, and best corrected visual acuity (BCVA) 0.7 on the right and 0.2 on the left eye. We have monitored intraocular pressure (IOP), the changes in the visual field and optic nerve. Preoperative IOP was 28 mmHg on the right and 30 mmHg on the left eye. The follow up period was 24 months with time points for measured parameters every 3 months. After 18 months IOP remained in the normal values (average 17 mmHg) on the right eye, but on the left eye it increased up to 28 mmHg. SLT re-treatment was carried out on the left eye and the IOP stabilized again on the values between 16-18mmHg. There were no significant change in the visual field and optic nerve configuration before and after SLT (C/D value for right eye: 0.3-0.4; C/D left eye: 0.5). Based on this case report, SLT seems to be very effective treatment for maintaining regular IOP in patient with PEX who is allergic to all types of medications. 相似文献
18.
19.
20.
Bauer N Leljak-Levanic D Jelaska S 《Zeitschrift für Naturforschung. C, Journal of biosciences》2004,59(7-8):554-560
Agrobacteria mediated Coleus blumei tumour tissues were cultured in vitro on MS medium. Sixteen diversified transformed callus cultures were maintained for several years in the absence of plant growth regulators and antibiotics without affecting the growth rate. Rosmarinic acid was detected spectrophotometrically in all tissue lines but in different quantities. The highest rosmarinic acid accumulation detected was 11% of dry tissue mass. The relation between culture growth and rosmarinic acid production was investigated in three callus lines. The lines showed different rosmarinic acid accumulation in relation to their growth rate; it was either parallel or inversely related to the tissue growth. The effects of certain medium constituents on the callus growth and rosmarinic acid accumulation were examined in four tumour cell lines. Addition of 4% or 5% sucrose stimulated rosmarinic acid synthesis and decreased callus growth. Nitrogen reduction to one half or one quarter of initial concentration did not affect rosmarinic acid synthesis and decreased callus growth in three lines, while it increased rosmarinic acid accumulation and callus growth in one line. Addition of 0.1 mg/l Phe stimulated rosmarinic acid production in two lines but had little effect on the rosmarinic acid level in others. Rosmarinic acid production was significantly improved on modified macronutrients, where the Ac2 line produced 16.5 mg of rosmarinic acid per tube (0.2 g of dry wt) after being in culture for 35 days. 相似文献