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41.
42.
蒙古国喀尔喀部蒙古族4项群体指趾遗传学特征研究 总被引:1,自引:0,他引:1
在内蒙古民族大学调查了160例(男66例,女94例)来自蒙古国的喀尔喀蒙古族留学生的拇指类型、环食指长、指甲形状、足趾长4项群体指趾遗传学特征。研究结果:1)直型拇指率为44.38%,环指长率78.13%,指甲形状长型率58.75%、方型率6.88%、扁型率34.38%,足趾类型拇趾长率35.00%;2)指甲形状出现率性别间差异具统计学意义,两两特征间均未表现出明显相关关系;3)与我国10个蒙古族族群相比,多数差异具有统计学意义。 相似文献
43.
Heparin and its derivatives bind to HIV-1 recombinant envelope glycoproteins, rather than to recombinant HIV-1 receptor, CD4 总被引:1,自引:0,他引:1
We have employed a direct radiolabel binding assay to investigate the
interaction between3H-heparin and recombinant envelope glycoproteins,
rgp120s, derived from several different isolates of HIV-1. Comparable
dose-dependent binding is exhibited by rgp120s from isolates IIIB, GB8, MN
and SF-2. Under identical experimental conditions the binding of3H- heparin
to a recombinant soluble form of the cellular receptor for gp120, CD4, is
negligible. The binding of3H-heparin to rgp120 is competed for by excess
unlabeled heparin and certain other, but not all, glycosaminoglycan and
chemically modified heparins. Of a range of such polysaccharides tested,
ability to compete with3H-heparin for binding was strictly correlated with
inhibition of HIV-1 replication in vitro. Those possessing potent
anti-HIV-1 activity were effective competitors, whereas those having no or
little anti-HIV-1 activity were poor competitors. Scatchard analysis
indicates that the K d of the interaction between heparin and rgp120 is 10
nM. Binding studies conducted in increasing salt concentrations confirm
that the interaction is ionic in nature. Synthetic 33-35 amino acid
peptides based on the sequence of the V3 loop of gp120 also bind to heparin
with high affinity. V3 loop peptides that are cyclized due to terminal
cysteine residues show more selective binding than their uncyclized
counterparts. Overall, these data demonstrate further that heparin exerts
its anti-HIV-1 activity by binding to the envelope glycoprotein of HIV-1,
rather than its cellular receptor, CD4. This study confirms that the V3
loop of gp120 is the site at which heparin exerts its anti- HIV-1 activity.
Moreover, it reveals that high affinity binding to heparin is shared by all
four rgp120s examined, despite amino acid substitutions within the V3 loop.
相似文献
44.
Kiray M Bagriyanik HA Pekcetin C Ergur BU Uysal N Ozyurt D Buldan Z 《Physiological research / Academia Scientiarum Bohemoslovaca》2006,55(2):205-212
Oxidative stress may play a major role in the aging process and associated cognitive decline. Therefore, antioxidant treatment may alleviate age-related impairment in spatial memory. Cognitive impairment could also involve the age-related morphological alterations of the hippocampal formation. The aim of this study was to examine the relationship between the effects of deprenyl, an irreversible monoamine-oxidase B inhibitor, on spatial memory by oxidant stress and on the total number of neurons in the hippocampus CA1 region of aged male rats. In this study, 24-month-old male rats were used. Rats were divided into control and experimental groups which received an injection of deprenyl for 21 days. Learning experiments were performed for six days in the Morris water maze. Spatial learning was significantly better in deprenyl-treated rats compared to saline-treated rats. Deprenyl treatment elicited a significant decrease of lipid peroxidation in the prefrontal cortex, striatum and hippocampus regions and a significant increase of glutathione peroxidase activity in the prefrontal cortex and hippocampus. It was observed that deprenyl had no effect on superoxide dismutase activity. The total number of neurons in the hippocampus CA1 region was significantly higher in the deprenyl group than in the control group. In conclusion, we demonstrated that deprenyl increases spatial memory performance in aged male rats and this increase may be related to suppression of lipid peroxidation and alleviation of the age-related decrease of the number of neurons in the hippocampus. The results of such studies may be useful in pharmacological alleviation of the aging process. 相似文献
45.
GYUNGAH KIM YOON MI JIN YEONSIL YU HA YEONG KIM SANGMEE AHN JO YOON JEONG PARK YOON SHIN PARK INHO JO 《Cytotherapy》2018,20(8):1013-1027
Background and aims
Osteoporosis, which is a disease characterized by weakening of the bone, affects a large portion of the senior population. The current therapeutic options for osteoporosis have side effects, and there is no effective treatment for severe osteoporosis. Thus, we urgently need new treatment strategies, such as topical therapies and/or safe and effective stem cell therapies.Methods
We investigated the therapeutic potential of directly injecting human tonsil-derived mesenchymal stem cells (TMSC) into the right proximal tibias of ovariectomized postmenopausal osteoporosis model mice. Injections were given once (1×) or twice (2×) during the 3-month experimental period. At the end of the experiment, micro-computed tomographic images revealed some improvement in the proximal tibias and more significant improvement in the femoral heads of treated mice.Results
Osteogenic effect was qualitatively and quantitatively more pronounced in TMSC/2×-treated mice. Furthermore, TMSC/2×?mice exhibited significant recovery of the serum osteocalcin level, which is pathologically elevated in osteoporosis, and increased serum alkaline phosphatase, which indicates bone formation. TMSC therapy was generally well tolerated and caused no apparent toxicity in the experimental mice. Moreover, TMSC therapy reduced visceral fat.Conclusion
Our results demonstrate that double injection of TMSC directly into the proximal tibia triggers recovery of osteoporosis, and thus could be a potential therapeutic approach for severe bone loss. 相似文献46.
Helle Lyb?k Diederik de Bruijn Anke HA den Engelsman-van Dijk Darya Vanichkina Chirag Nepal Atle Brendehaug Gunnar Houge 《Epigenetics》2014,9(3):416-427
It was recently shown that duplications of the RevSex element, located 0.5 Mb upstream of SOX9, cause XX-disorder of sex development (DSD), and that deletions cause XY-DSD. To explore how a 148 kb RevSex duplication could have turned on gonadal SOX9 expression in the absence of SRY in an XX-male, we examined the chromatin landscape in primary skin fibroblast cultures from the index, his RevSex duplication-carrier father and six controls. The ENCODE project supports the notion that chromatin state maps show overlap between different cell types, i.e., that our study of fibroblasts could be of biological relevance. We examined the SOX9 regulatory region by high-resolution ChIP-on-chip experiments (a kind of “chromatin-CGH”) and DNA methylation investigations. The RevSex duplication was associated with chromatin changes predicting better accessibility of the SRY-responsive TESCO enhancer region 14–15 kb upstream of SOX9. Four kb downstream of the TESCO evolutionary conserved region, a peak of the enhancer/promoter-associated H3K4me3 mark was found together with a major dip of the repressive H3K9me3 chromatin mark. Similar differences were also found when three control males were compared with three control females. A marked male/female difference was a more open chromatin signature in males starting ~400 kb upstream of SOX9 and increasing toward the SOX9 promoter. In the RevSex duplication-carrier father, two positions of DNA hypomethylation were also found, one corresponding to the H3K4me3 peak mentioned above. Our results suggest that the RevSex duplication could operate by inducing long-range epigenetic changes. Furthermore, the differences in chromatin state maps between males and females suggest that the Y chromosome or X chromosome dosage may affect chromatin conformation, i.e., that sex-dependent gene regulation may take place by chromatin modification. 相似文献
47.
R Quintero‐Torres HA Castillo‐Matadamas Jeff F Young RM Bermúdez Cruz 《Luminescence》2014,29(5):440-444
Relaxation dynamics is universal in science and engineering; its study serves to parameterize a system's response and to help identify a microscopic model of the processes involved. When measured data for a phenomenon cannot be fitted using one exponential, the choice of an alternative function to describe the decay becomes nontrivial. Here, we contrast two different, but fundamentally related approaches to fitting nontrivial decay curves; exponential decomposition and the gamma probability density function. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
48.
Background
Extrapontine myelinolysis presenting with extra pyramidal features suggestive of parkinsonism may be a challenging clinical syndrome. Clinicians should maintain their vigilance while correcting electrolyte imbalances, especially with associated co-morbidity.Case presentation
A 41-year-old woman presented with acute parkinsonism like features while on a holiday. This followed slow correction of hyponatraemia after repeated vomiting. MRI changes were suggestive of Extrapontine myelinolysis(EPM). This case is at variance with four previous cases reported in the medical literature in that the patient made a full clinical recovery and the MR changes resolved with symptomatic support alone.Conclusion
Extrapontine myelinolysis could make a complete recovery with symptomatic support alone. During hyponatraemia correction, rapid osmotic shifts of fluid that cause hypernatremia, causes myelinolysis rather than absolute serum sodium level. Even gradual correction of hyponatraemia can produce myelinolysis, especially with pre-existing malnourishment, alcoholism, drug misuse, Addison's disease and immuno-suppression. Pallidial sparing is typical of EPM in MRI scans. 相似文献49.
J. RICHARD PILSNER ALICIA L. LAZARUS DONG‐HA NAM ROBERT J. LETCHER CHRISTIAN SONNE RUNE DIETZ NILADRI BASU 《Molecular ecology》2010,19(2):307-314
In this paper we describe a novel approach that may shed light on the genomic DNA methylation of organisms with non‐resolved genomes. The LUminometric Methylation Assay (LUMA) is permissive for genomic DNA methylation studies of any genome as it relies on the use of methyl‐sensitive and ‐insensitive restriction enzymes followed by polymerase extension via Pyrosequencing technology. Here, LUMA was used to characterize genomic DNA methylation in the lower brain stem region from 47 polar bears subsistence hunted in central East Greenland between 1999 and 2001. In these samples, average genomic DNA methylation was 57.9% ± 6.69 (SD; range was 42.0 to 72.4%). When genomic DNA methylation was related to brain mercury (Hg) exposure levels, an inverse association was seen between these two variables for the entire study population (P for trend = 0.17). After dichotomizing animals by gender and controlling for age, a negative trend was seen amongst male animals (P for trend = 0.07) but no associations were found in female bears. Such sexually dimorphic responses have been found in other toxicological studies. Our results show that genomic DNA methylation can be quantitatively studied in a highly reproducible manner in tissue samples from a wild organism with a non‐resolved genome. As such, LUMA holds great promise as a novel method to explore consequential questions across the ecological sciences that may require an epigenetic understanding. 相似文献
50.
HAI HA HOANG JULIEN SECHET CHRISTOPHE BAILLY JULIETTE LEYMARIE FRANÇOISE CORBINEAU 《Plant, cell & environment》2014,37(6):1393-1403
Germination of primary dormant barley grains is promoted by darkness and temperatures below 20 °C, but is strongly inhibited by blue light. Exposure under blue light at 10 °C for periods longer than five days, results in a progressive inability to germinate in the dark, considered as secondary dormancy. We demonstrate that the inhibitory effect of blue light is reinforced in hypoxia. The inhibitory effect of blue light is associated with an increase in embryo abscisic acid (ABA) content (by 3.5‐ to 3.8‐fold) and embryo sensitivity to both ABA and hypoxia. Analysis of expression of ABA metabolism genes shows that increase in ABA mainly results in a strong increase in HvNCED1 and HvNCED2 expression, and a slight decrease in HvABA8′OH‐1. Among the gibberellins (GA) metabolism genes examined, blue light decreases the expression of HvGA3ox2, involved in GA synthesis, increases that of GA2ox3 and GA2ox5, involved in GA catabolism, and reduces the GA signalling evaluated by the HvExpA11 expression. Expression of secondary dormancy is associated with maintenance of high embryo ABA content and a low HvExpA11 expression. The partial reversion of the inhibitory effect of blue light by green light also suggests that cryptochrome might be involved in this hormonal regulation. 相似文献