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71.
Caspases play an important role in programmed cell death. Caspase-3 is a key executioner of apoptosis, whose activation is mediated by the initiator caspases, caspase-8 and caspase-9. The present study tested the hypothesis that cerebral hypoxia results in increased activation and expression of caspases-3, -8, and -9 in the cytosolic fraction of the cerebral cortex of newborn piglets. To test this hypothesis the activity and expression of caspases-3, -8, and -9 were determined in newborn piglets divided into normoxic and hypoxic groups. Caspase activity was determined spectrofluorometrically using enzyme specific substrates. The expression of caspase protein was assessed by Western blot analysis using enzyme specific antibody. Caspases-3, -8, and -9 activity and expression was significantly higher in the hypoxic group than in the normoxic group. These results demonstrate that hypoxia induces activation and increased expression of both the initiator caspases and the executioner caspase in the cerebral cortex of newborn piglets. We conclude that hypoxia results in stimulation of both the pathways of caspase-3 activation. 相似文献
72.
Studies indicate that phosphorylated Bcl-2 cannot form a heterodimer with Bax and thus may lose its antiapoptotic potential. The present study tests the hypothesis that graded hypoxia in cerebral tissue induces the phosphorylation of Bcl-2, thus altering the heterodimerization of Bcl-2 with Bax and subsequently leading to apoptosis. Anesthetized, ventilated newborn piglets were assigned to a normoxic and a graded hypoxic group. Cerebral cortical neuronal nuclei were isolated and immunoprecipitated; immune complexes were separated and reacted with Bcl-2 and Bax specific antibodies. The results show an increased level of serine/tyrosine phosphorylated Bcl-2 in nuclear membranes of hypoxic animals. The level of phosphorylated Bcl-2 protein increased linearly with decrease in tissue PCr. The level of phosphorylated Bax in the neuronal nuclear membranes was independent of cerebral tissue PCr. The data shows that during hypoxia, there is increased phosphorylation of Bcl-2, which may prevent its heterodimerization with Bax and lead to increased proapoptotic activity due to excess Bax in the hypoxic brain. Further increased phosphorylation of Bcl-2 may alter the Bcl-2/Bax-dependent antioxidant, lipid peroxidation and pore forming activity, as well as the regulation of intranuclear Ca2+ and caspase activation pathways. We speculate that increased phosphorylation of Bcl-2 in neuronal nuclear membranes is a potential mechanism of programmed cell death activation in the hypoxic brain. 相似文献
73.
Nitric oxide synthase in filariae: demonstration of nitric oxide production by embryos in Brugia malayi and Acanthocheilonema viteae 总被引:2,自引:0,他引:2
The radical gas nitric oxide (NO) is synthesized by nitric oxide synthase (NOS) from l-arginine and molecular oxygen. Nitric oxide is an important signaling molecule in invertebrate and vertebrate systems. Previously we have shown that NOS is localized to more tissues in Brugia malayi than has been reported in Ascaris suum. In this paper, we analyze the distribution of NOS in Acanthocheilonema viteae, a filarial nematode that differs from B. malayi in that A. viteae females release microfilariae without a sheath. A. viteae is also one of a few filarial parasites without the Wolbachia intracellular endosymbiont. By use of a specific antibody, NOS was demonstrated in extracts of A. viteae and Dirofilaria immitis. The localization pattern of NOS in A. viteae was similar to that seen in B. malayi, with the enzyme localized to the body wall muscles of both sexes, developing spermatozoa, intrauterine sperm, and early embryos. By use of DAF-2, a fluorescent indicator specific for nitric oxide, the embryos of B. malayi and A. viteae were demonstrated to produce NO ex utero. The near identical staining patterns seen in A. viteae and B. malayi argue that NO is not produced by Wolbachia, nor is it produced by the nematodes in response to the infection. Localization of NOS to the sperm of filarial nematodes suggests a role for NO during fertilization as has been described for sea urchin and ascidian fertilization. Demonstration of the activity of embryonic NOS supports our earlier hypothesis that NO is a signaling molecule during embryogenesis in filarial nematodes. 相似文献
74.
Shahreen Raihana Dustin Dunsmuir Tanvir Huda Guohai Zhou Qazi Sadeq-ur Rahman Ainara Garde Md Moinuddin Walter Karlen Guy A. Dumont Niranjan Kissoon Shams El Arifeen Charles Larson J. Mark Ansermino 《PloS one》2015,10(11)
Background
The reduction in the deaths of millions of children who die from infectious diseases requires early initiation of treatment and improved access to care available in health facilities. A major challenge is the lack of objective evidence to guide front line health workers in the community to recognize critical illness in children earlier in their course.Methods
We undertook a prospective observational study of children less than 5 years of age presenting at the outpatient or emergency department of a rural tertiary care hospital between October 2012 and April 2013. Study physicians collected clinical signs and symptoms from the facility records, and with a mobile application performed recordings of oxygen saturation, heart rate and respiratory rate. Facility physicians decided the need for hospital admission without knowledge of the oxygen saturation. Multiple logistic predictive models were tested.Findings
Twenty-five percent of the 3374 assessed children, with a median (interquartile range) age of 1.02 (0.42–2.24), were admitted to hospital. We were unable to contact 20% of subjects after their visit. A logistic regression model using continuous oxygen saturation, respiratory rate, temperature and age combined with dichotomous signs of chest indrawing, lethargy, irritability and symptoms of cough, diarrhea and fast or difficult breathing predicted admission to hospital with an area under the receiver operating characteristic curve of 0.89 (95% confidence interval -CI: 0.87 to 0.90). At a risk threshold of 25% for admission, the sensitivity was 77% (95% CI: 74% to 80%), specificity was 87% (95% CI: 86% to 88%), positive predictive value was 70% (95% CI: 67% to 73%) and negative predictive value was 91% (95% CI: 90% to 92%).Conclusion
A model using oxygen saturation, respiratory rate and temperature in combination with readily obtained clinical signs and symptoms predicted the need for hospitalization of critically ill children. External validation of this model in a community setting will be required before adoption into clinical practice. 相似文献75.
Sumbul Firdaus Anupam Dhasmana Vandana Srivastava Tasneem Bano Afreen Fatima Qazi Mohammad Sajid Jamal Roshan Jahan Gulshan Wadhwad Mohtashim Lohani 《Bioinformation》2015,11(3):122-126
Fullerenes have attracted considerable attention due to their unique chemical structure and potential applications which has
opened wide venues for possible human exposure to various fullerene types. Therefore, in depth knowledge of how fullerene may
interfere with various cellular processes becomes quite imperative. The present study was designed to investigate how the
presence of fullerene affect the binding of DNA with different enzymes involved in replication process. Different fullerenes were
first docked with DNA and then binding scores of different enzymes was analyzed with fullerene docked DNA. C30, C40 & C50
once docked with DNA, reduced the binding score of primase, whereas no significant change in the binding score was observed
with the helicase, ssb protein, dna pol δ, dna pol ε, ligase, DNA clamp, and topoisomerases. On the contrast, the binding score of
RPA14 decreases in fluctuating manner while interacting with increasing molecular weight of fullerene bound single-stranded
DNA complex. The study revealed the affect of fullerene family interacting with DNA on the binding pattern of enzymes involved
in replication process. Study suggests that the presence of most of fullerenes may not affect the activity of these enzymes necessary
for replication process whereas C30, C40 & C50 may disrupt the activity of primase, (strating point for DNA polymerase) its
docking score decreases from 13820 to 10702. 相似文献
76.
Arif Shafi Wani Aqil Ahmad Shamsul Hayat Qazi Fariduddin 《Saudi Journal of Biological Sciences》2013,20(2):183-193
The present study was carried out to examine salt-induced modulation in growth, photosynthetic characteristics and antioxidant system in two cultivars of Brassica juncea Czern and Coss varieties (Varuna and RH-30). The surface sterilized seeds of these varieties were sown in the soil amended with different levels (2.8, 4.2 or 5.6 dsm−1) of sodium chloride under a simple randomized block design. The salt treatment significantly decreased growth, net photosynthetic rate and its related attributes, chlorophyll fluorescence, SPAD value of chlorophyll, leaf carbonic anhydrase activity and leaf water potential, whereas electrolyte leakage, proline content, and activity of catalase, peroxidase and superoxide dismutase enzymes increased in both the varieties at 30 d stage of growth. The variety Varuna was found more resistant than RH-30 to the salt stress and possessed higher values for growth, photosynthetic attributes and antioxidant enzymes. Out of the graded concentrations (2.8, 4.2 or 5.6 dsm−1) of sodium chloride, 2.8 sm−1 was least toxic and 5.6 dsm−1 was most harmful. The variation in the responses of these two varieties to salt stress is attributed to their differential photosynthetic traits, SPAD chlorophyll value and antioxidant capacity, which can be used as potential markers for screening mustard plants for salt tolerance. 相似文献
77.
Nighat Nazir Surrinder Koul Mushtaq Ahmad Qurishi Subhash Chandra Taneja Ghulam Nabi Qazi 《Biocatalysis and Biotransformation》2013,31(2):118-123
The regioselective acylation of irilone, isolated from Iris germanica, with vinylacetate and propenylacetate and deacylation of irilone diacetate with n-butanol were studied using lipases from Aspergillus niger, Mucor miehei, Pseudomonas cepacia, Candida cylindracea, porcine pancreas and Candida antarctica. Significant conversion of irilone to 4′-O-acetylirilone was achieved using P. cepacia lipase, while irilone diacetate was converted to 5-O-acetylirilone by the enzymatic action of lipases from M. miechei, P. cepacia and porcine pancreas under different experimental conditions. This preferential protection/deprotection furnishes an opportunity to modify the structure of irilone by selective derivatization that may help to change its biological activities by modifying its amphiphilic/lipophilic balance. 相似文献
78.
Hasan Muhammad A. Shahid Hira Khan Hashim R. Qazi Saad A. Fraser Matthew 《Applied psychophysiology and biofeedback》2021,46(2):183-194
Applied Psychophysiology and Biofeedback - Neurofeedback (NF) training based on alpha upregulation has been widely used on patient and healthy populations. However, active voluntary modulation of... 相似文献
79.
Background
Human sexual orientation is influenced by genetic and non-shared environmental factors as are two important psychological correlates – childhood gender typicality (CGT) and adult gender identity (AGI). However, researchers have been unable to resolve the genetic and non-genetic components that contribute to the covariation between these traits, particularly in women.Methodology/Principal Findings
Here we performed a multivariate genetic analysis in a large sample of British female twins (N = 4,426) who completed a questionnaire assessing sexual attraction, CGT and AGI. Univariate genetic models indicated modest genetic influences on sexual attraction (25%), AGI (11%) and CGT (31%). For the multivariate analyses, a common pathway model best fitted the data.Conclusions/Significance
This indicated that a single latent variable influenced by a genetic component and common non-shared environmental component explained the association between the three traits but there was substantial measurement error. These findings highlight common developmental factors affecting differences in sexual orientation. 相似文献80.
Gehrmann U Qazi KR Johansson C Hultenby K Karlsson M Lundeberg L Gabrielsson S Scheynius A 《PloS one》2011,6(7):e21480