全文获取类型
收费全文 | 173篇 |
免费 | 9篇 |
出版年
2023年 | 4篇 |
2022年 | 1篇 |
2021年 | 7篇 |
2020年 | 8篇 |
2019年 | 4篇 |
2018年 | 3篇 |
2017年 | 3篇 |
2016年 | 14篇 |
2015年 | 9篇 |
2014年 | 5篇 |
2013年 | 9篇 |
2012年 | 16篇 |
2011年 | 5篇 |
2010年 | 3篇 |
2009年 | 4篇 |
2008年 | 7篇 |
2007年 | 11篇 |
2006年 | 14篇 |
2005年 | 3篇 |
2004年 | 4篇 |
2003年 | 3篇 |
2002年 | 12篇 |
2001年 | 2篇 |
2000年 | 2篇 |
1999年 | 1篇 |
1991年 | 1篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1979年 | 1篇 |
1973年 | 1篇 |
1972年 | 2篇 |
1968年 | 1篇 |
1966年 | 1篇 |
1948年 | 2篇 |
1943年 | 1篇 |
1942年 | 1篇 |
1941年 | 1篇 |
1940年 | 1篇 |
1932年 | 1篇 |
1928年 | 1篇 |
1926年 | 1篇 |
1918年 | 1篇 |
1910年 | 1篇 |
1907年 | 1篇 |
1905年 | 1篇 |
1900年 | 1篇 |
排序方式: 共有182条查询结果,搜索用时 31 毫秒
61.
62.
M Yuksel DG Colak M Akin I Cianga M Kukut EI Medine M Can S Sakarya P Unak S Timur Y Yagci 《Biomacromolecules》2012,13(9):2680-2691
The generation and fabrication of nanoscopic structures are of critical technological importance for future implementations in areas such as nanodevices and nanotechnology, biosensing, bioimaging, cancer targeting, and drug delivery. Applications of carbon nanotubes (CNTs) in biological fields have been impeded by the incapability of their visualization using conventional methods. Therefore, fluorescence labeling of CNTs with various probes under physiological conditions has become a significant issue for their utilization in biological processes. Herein, we demonstrate a facile and additional fluorophore-free approach for cancer cell-imaging and diagnosis by combining multiwalled CNTs with a well-known conjugated polymer, namely, poly(p-phenylene) (PP). In this approach, PP decorated with poly(ethylene glycol) (PEG) was noncovalently (π-π stacking) linked to acid-treated CNTs. The obtained water self-dispersible, stable, and biocompatible f-CNT/PP-g-PEG conjugates were then bioconjugated to estrogen-specific antibody (anti-ER) via -COOH functionalities present on the side-walls of CNTs. The resulting conjugates were used as an efficient fluorescent probe for targeted imaging of estrogen receptor overexpressed cancer cells, such as MCF-7. In vitro studies and fluorescence microscopy data show that these conjugates can specifically bind to MCF-7 cells with high efficiency. The represented results imply that CNT-based materials could easily be fabricated by the described approach and used as an efficient "fluorescent probe" for targeting and imaging, thereby providing many new possibilities for various applications in biomedical sensing and diagnosis. 相似文献
63.
Sayın D Cakır DT Gençer N Arslan O 《Journal of enzyme inhibition and medicinal chemistry》2012,27(4):595-598
Paraoxonase (PON) is an organophosphate hydrolyser enzyme which also has antioxidant properties in metabolism. Due to its crucial functions, the inhibition of the enzyme is undesirable and very dangerous. PON enzyme activity should not be altered in any case. Inhibitory investigations of this enzyme are therefore important and useful. Metal toxicology of enzymes has become popular in the recent years. Here, we report the in vitro inhibitory effects of some metal ions, including Ni(2+), Cd(2+), Cu(2+) and Hg(2+), on the activity of shark serum PON (SPON). For this purpose, we first purified the enzyme from shark Scyliorhinus canicula (LINNAEUS, 1758) serum and analysed the alterations in the enzyme activity in the presence of metal ions. The K(M) and V(max) is 0.227 mM and 454.545 U/mL, respectively. The results show that metal ions exhibit inhibitory effects on SPON1 at low concentrations with IC(50) values ranging from 0.29 to 2.00 mM. Copper was determined to be the most effective inhibitor with IC(50) of 0.29 mM. 相似文献
64.
In the present study mixed cultures that could grew in the molasses media were isolated from textile dye effluent and its decolorization activity was studied in a batch system under anaerobic conditions, in order to determine the optimal conditions required for the highest decolorization activity. The optimum pH value for decolorization was determined as 8 for all the dyes tested. In the experiment with pH 8 dye decolorizations by mixed cultures were investigated at about 96.2–1031.3 mg l−1 initial dye concentrations. The highest dye removal rates of mixed cultures were 94.9% for Reactive Red RB, 91.0% for Reactive Black B and 63.6% for Remazol Blue at 953.2, 864.9 and 1031.3 mg l−1 initial dye concentrations respectively within 24 h incubation period. When the Reactive Red RB was used, approximately 82–98% total color removal was obtained at between 96.2 and 953.2 mg l−1 initial dye concentrations after 12 h of incubation at 35 °C. These results show that our enriched mixed cultures have the potential to serve as an excellent biomass for the use in reactive dye removal from wastewaters under anaerobic conditions. 相似文献
65.
Kucukarabaci B Gunes HV Ozdemir G Cosan D Ozbabalik D Dikmen M Degirmenci I 《Genetic testing》2008,12(3):443-451
Aim: This study was carried out to determine if there is any association between plasminogen activator inhibitor type-1 (PAI-1) gene 4G/5G polymorphism and plasma PAI-1 enzyme activity in acute stroke patients. Methods: In this study, 333 genomic DNAs (from 253 acute stroke patients and 80 healthy subjects) were analyzed. Genomic DNAs were prepared from peripheral blood using a saline method. These DNAs were amplified by PCR method using primers specific for 4G and 5G alleles. PCR products were separated by 2% agarose gel electrophoresis and visualized by a charge coupled device (CCD) camera. PAI-1 enzyme activities were measured by ELISA method. The results were evaluated statistically with Student's t-test, chi(2)-test, one-way analysis of variance, and stepwise regression analysis. Results: In this study, frequency of PAI-1 gene 4G5G genotype was found to be low both in patients and controls. PAI-1 enzyme activities were significantly increased in acute stroke patients compared to controls. Although PAI-1 gene 4G5G genotype frequencies were low, the patients carrying this allele had highest plasma PAI-1 enzyme activity; likewise, although PAI-1 gene 4G4G genotype frequencies were high, the patients carrying this allele had lowest plasma PAI-1 enzyme activities. Homocysteine levels had a positive effect of 65% on plasma PAI-1 enzyme activities. Conclusion: Consequently, in this study, we may assert that PAI-1 gene, 4G4G and 5G5G genotypes, PAI-1 activity, and homocysteine level determination are significant criteria for identifying patients who are likely to develop stroke; on the other hand, a direct relation does not exist between gene polymorphism and enzyme activity. 相似文献
66.
Majid Hafezparast Simon Ball Sharon J. Nicholson Abi Witherden Demet Arac Neil Broadway David Saggerson Edwin Cooper Mahmoud Naase Stephen Gokhale Patti Quant Carol Lascelles Carole Nickols Cathy S. Baker Josephine Peters Joanne E. Martin Elizabeth M.C. Fisher 《Mammalian genome》2002,13(7):359-364
Low blood sugar levels are a well-known cause of severe illness and often death in newborn humans, especially those that are small for age. Few of the causes of neonatal hypoglycemia are known, and many remain to be found. We describe a novel mouse mutant, skijumper (skimp), in which pups, despite feeding well, have low levels of glucose and develop opisthotonos, followed by death typically within a few days after birth. Genetic mapping studies have localized the lesion to a approximately 1 cM interval on mouse Chromosome (Chr) 7 between D7Mit318 and D7Mit93. We have carried out extensive analysis to define the phenotype and its likely cause. In addition to low blood glucose, affected skijumper mice have lowglycogen and ketone levels. Mass spectrometric analysis of blood samples has excluded major defects in amino acid metabolism. Initial biochemical analyses suggested a defect in ketogenesis as one possible cause of this phenotype. However, measurements of levels and activities of carnitine, carnitine palmitoyl transferases, and other enzymes involved in ketogenesis, along with studies of mitochondrial structure and function, did not demonstrate significant differences between skijumper, unaffected littermates, and control wild-type mice. These results indicate that abnormal enzyme activity in known pathways does not appear to be the primary biochemical lesion in skijumper. The skijumper may be a new valuable model for studying and understanding one type of neonatal morbidity and death. 相似文献
67.
68.
Previous studies in rodents have indicated that the facial changes of fetal alcohol syndrome (FAS) closely resemble those of a mild form of holoprosencephaly. In order to examine this relationship in non-human primates, we evaluated a 133-day gestation macaque (Macaca nemestrina) with holoprosencephaly, median cleft lip and palate, and encephalocele. The mother had been given ethanol once per week (1.8 g/kg body weight) from weeks 2 to 19 postconception. Diagnosis of holoprosencephaly was made following ultrasound evaluation for polyhydramnios and delivery of the female fetus by caesarean section. Another fetus of identical age was delivered by caesarean section for use as a control. Both fetuses were studied by anthropometric, gross, radiographic, and histologic techniques. In the fetus exposed to alcohol, no extracranial anomalies were identified and the karyotype was normal. The brain was micrencephalic, with absent olfactory bulbs, tracts, optic nerves and chiasma, fused frontal lobes, and a single, dilated lateral ventricle; a parietooccipital encephalocele consisted of thin, dysplastic cortex bordering the ventricle; the cerebellum was dysplastic and superiorly displaced. Within the craniofacial complex, anophthalmia was bilateral; premaxillary components were absent, palatal shelves separate, the maxillae closeset, and the ethmoid bone small and deformed. Most of these defects are similar to those encountered in humans with holoprosencephaly and support the hypothesis of shared etiologic and pathogenetic relations between the facial anomalies of fetal alcohol syndrome and holoprosencephaly. 相似文献
69.
The presence of multigerm seedballs in the chenopodiacious genusSpinacia is noted. In the wild, colonising, and weedy dioecious species,S. turkestanica andS. tetrandra, the distribution of a multigerm seedball could effectively overcome the problem posed by isolation of the sexes. The hypothesis is tested assessing the extent of intra-seedball progeny hybridisations and seed production in the two wild species. The success in seed production by intra-seedball progeny crosses suggests that the distribution of such seedball progeny groups permits not only a percentage survival under isolation of these dioecious plants, but also the colonisation of areas outside that of the parent populations. 相似文献
70.
Hasan?Akgül Demet?Y?lmazkayaEmail author Ilgaz?Akata Aycan?Tosuno?lu Adem?B??ak?? 《Aerobiologia》2016,32(3):441-452
The aim of this study was to present the first airborne fungal spore research results of SE of Turkey. The presence and abundance of fungal spores were investigated with a Hirst-type volumetric spore trap (Lanzoni, VPSS 2000) for 2 years between the periods January 2010 and December 2011. A total of 211,521 spores and 47 fungal taxa belonging to Anamorphic Fungi, Phyla Ascomycota and Basidiomycota were recorded. Aspergillus/Penicillium spores type, unidentified spores, spores of Myxomycota and hyphal fragments were also recorded as groups. The relationship between fungal spore counts and several meteorological parameters was examined. Cladosporium was determined as the predominant genus (56.48 %); hyphal fragments (14.94 %), Ustilago (13.96 %) and Alternaria (5.79 %) were revealed as the common fungal aerosols of Gaziantep atmosphere. With this study, the first aeromycological survey of SE of Turkey has been conducted and new information on the field of aerobiology in Turkey has been introduced. 相似文献