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1.
H Rivera M Moller L M Baltazar A Escalante-Herrera D Garcia-Cruz 《Annales de génétique》1988,31(4):244-246
A 24-year-old female with a Swyer syndrome phenotype was found to have a 46,X,del (Y) (p11) karyotype. This observation is consistent with the recently confirmed assignment of the testis-determining master gene to the deletion interval 1A of the Y (Page et al., 1987). Otherwise, it illustrates the etiological heterogeneity of the Swyer phenotype and allows to emphasize the de novo origin of XYp-females. 相似文献
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B. M. Baltazar A. L. Scharen W. E. Kronstad 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1990,79(3):422-426
Summary Differences in levels of resistance toSeptoria tritici blotch were observed in plants with a specific height-reducing gene. When the gene Rht
2 was present either as an isoline or in the progeny, a higher degree of resistance was found. The most susceptible plants were observed in populations carrying the Rht
1 gene. Associations, as determined by phenotypic correlations, were detected betweenSeptoria tritici blotch and tall stature, late heading, and maturity. Plants having short stature, early heading, early maturity, and acceptable levels of resistance were identified in the F2 population whenRht
2 was present. Results of this study indicated that wheat breeders must select the appropriate dwarfing source that may confer resistance and grow large F2 populations, in order to increase the probability of obtaining desired genotypes. 相似文献
4.
We used botulinum neurotoxins (BoNT) to examine whether differences in the secretory activity of noradrenergic and adrenergic chromaffin cells are related to differences in the exocytotic machinery of these two types of bovine adrenal medulla cells. Cleavage of syntaxin and SNAP-25 by BoNT/C1 decreased in a dose-dependent way the release of both noradrenaline and adrenaline, but noradrenaline release was more sensitive to BoNT/C1. Cleavage of SNAP-25 by BoNT/A also had a larger inhibitory effect on noradrenaline release than on adrenaline release. Neither BoNT/C1 nor BoNT/A affected the intracellular Ca2+ responses induced by K+-depolarisation, and the extent of the inhibition of K+-evoked catecholamine release by selective blockers of voltage-gated Ca2+ channels was not affected by BoNT/C1. Therefore, our data do not support the hypothesis of a regulatory effect of syntaxin or SNAP-25 on the activity of Ca2+ channels. The lower sensitivity of adrenaline release to BoNT was not due to a reduced ability of the toxins to enter or to cleave their protein targets in adrenergic cells, since immunoblot analysis showed the cleavage of a larger fraction of syntaxin 1A in adrenergic cells, as compared to the cleavage in noradrenergic cells. The immunoblot analysis also showed larger amounts of syntaxin 1A in noradrenergic chromaffin cells than in adrenergic cells. Thus, in spite of a greater cleavage of syntaxin 1A in adrenergic cells by BoNT/C1, adrenaline release was less sensitive to BoNT/C1, suggesting that the release process in noradrenergic cells might be more dependent on syntaxin 1A and SNAP-25, as compared to adrenergic cells. 相似文献
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Transthyretin interacts with metallothionein 2 总被引:1,自引:0,他引:1
Gonçalves I Quintela T Baltazar G Almeida MR Saraiva MJ Santos CR 《Biochemistry》2008,47(8):2244-2251
Transthyretin (TTR) is a 55 kDa homotetrameric protein known for the transport of thyroxine and the indirect transportation of retinol. Within the central nervous system, TTR is primary synthesized and secreted into the cerebral spinal fluid by the choroid plexus (CP), whereas most TTR in the systemic circulation is produced and secreted by the liver. TTR is involved in two types of amyloid disease, the senile systemic amyloidosis and the familial amyloidotic polyneuropathy. TTR has also been implicated in the sequestration of amyloid beta peptide (Abeta), preventing its deposition. To explore other biological roles for TTR, we searched for protein-protein interactions using the yeast two-hybrid system with the full-length human TTR cDNA as bait. We found a novel interaction between TTR and metallothionein 2 (MT2) in human liver. This interaction was confirmed by competition binding assays, co-immunoprecipitation, cross-linking, and Western blotting experiments. Binding studies using MT1 showed a saturable specific interaction with TTR with a Kd of 244.8 +/- 44.1 nM. Western blotting experiments revealed a TTR-MT1/2 protein complex present in rat CP and kidney tissue extracts. Immunofluorescence experiments, in CP primary cell cultures and in CP paraffin sections, showed co-localization of TTR and MT1/2 in the cytoplasm of epithelial CP cells and localization of MT1/2 in the endoplasmic reticulum. Moreover, dot blot immunoassays of rat CSF provided the first evidence, to our knowledge, of circulating metallothionein in CSF. Taken together, we suggest that TTR-MT1/2 complexes may be functionally significant not only in healthy conditions but also in Abeta deposition in Alzheimer disease, thereby providing a novel potential therapeutic target. 相似文献
7.
Caoimhe Cawley Alison Wringe Raphael Isingo Baltazar Mtenga Benjamin Clark Milly Marston Jim Todd Mark Urassa Basia Zaba 《PloS one》2013,8(4)
Background
HIV counselling and testing (HCT) services can play an important role in HIV prevention by encouraging safe sexual behaviours and linking HIV-infected clients to antiretroviral therapy (ART). However, regular repeat testing by high-risk HIV-negative individuals is important for timely initiation of ART as part of the ‘treatment as prevention’ approach.Aim
To investigate HCT use during a round of HIV serological surveillance in northwest Tanzania in 2010, and to explore rates of repeat testing between 2003 and 2010.Methods
HCT services were provided during the fourth, fifth and sixth rounds of serological surveillance in 2003–2004 (Sero-4), 2006–2007 (Sero-5) and 2010 (Sero-6). HCT services have also been available at a government-run health centre and at other clinics in the study area since 2005. Questionnaires administered during sero-surveys collected information on socio-demographic characteristics, sexual behaviour and reported previous use of HCT services.Results
The proportion of participants using HCT increased from 9.4% at Sero-4 to 16.6% at Sero-5 and 25.5% at Sero-6. Among participants attending all three sero-survey rounds (n = 2,010), the proportions using HCT twice or more were low, with 11.1% using the HCT service offered at sero-surveys twice or more, and 25.3% having tested twice or more if reported use of HCT outside of sero-surveys was taken into account. In multivariable analyses, individuals testing HIV-positive were less likely to repeat test than individuals testing HIV-negative (aOR 0.17, 95% CI 0.006–0.52).Discussion/Conclusions
Although HCT service use increased over time, it was disappointing that the proportions ever testing and ever repeat-testing were not even larger, considering the increasing availability of HCT and ART in the study area. There was some evidence that HIV-negative people with higher risk sexual behaviours were most likely to repeat test, which was encouraging in terms of the potential to pick-up those at greatest risk of HIV-infection. 相似文献8.
Milly Marston Jessica Nakiyingi-Miiro Victoria Hosegood Tom Lutalo Baltazar Mtenga Basia Zaba 《PloS one》2016,11(3)
Background
UNAIDS official estimates of national HIV prevalence are based on trends observed in antenatal clinic surveillance, after adjustment for the reduced fertility of HIV positive women. Uptake of ART may impact on the fertility of HIV positive women, implying a need to re-estimate the adjustment factors used in these calculations. We analyse the effect of antiretroviral therapy (ART) provision on population-level fertility in Southern and East Africa, comparing trends in HIV infected women against the secular trends observed in uninfected women.Methods
We used fertility data from four community-based demographic and HIV surveillance sites: Kisesa (Tanzania), Masaka and Rakai (Uganda) and uMkhanyakude (South Africa). All births to women aged 15–44 years old were included in the analysis, classified by mother’s age and HIV status at time of birth, and ART availability in the community. Calendar time period of data availability relative to ART Introduction varied across the sites, from 5 years prior to ART roll-out, to 9 years after. Calendar time was classified according to ART availability, grouped into pre ART, ART introduction (available in at least one health facility serving study site) and ART available (available in all designated health facilities serving study site). We used Poisson regression to calculate age adjusted fertility rate ratios over time by HIV status, and investigated the interaction between ART period and HIV status to ascertain whether trends over time were different for HIV positive and negative women.Results
Age-adjusted fertility rates declined significantly over time for HIV negative women in all four studies. However HIV positives either had no change in fertility (Masaka, Rakai) or experienced a significant increase over the same period (Kisesa, uMkhanyakude). HIV positive fertility was significantly lower than negative in both the pre ART period (age adjusted fertility rate ratio (FRR) range 0.51 95%CI 0.42–0.61 to 0.73 95%CI 0.64–0.83) and when ART was widely available (FRR range 0.57 95%CI 0.52–0.62 to 0.83 95%CI 0.78–0.87), but the difference has narrowed. The interaction terms describing the difference in trends between HIV positives and negatives are generally significant.Conclusions
Differences in fertility between HIV positive and HIV negative women are narrowing over time as ART becomes more widely available in these communities. Routine adjustment of ANC data for estimating national HIV prevalence will need to allow for the impact of treatment. 相似文献9.
Circadian Locomotor Activity Under Artificial Light in the Freshwater Crab Pseudothelphusa americana
Manuel Miranda-Anaya Elisa Ramírez-Lomelí Vania P. Carmona-Alcocer Baltazar Barrera-Mera 《Biological Rhythm Research》2013,44(5):447-458
Long-term recordings of locomotor activity were obtained from intact freshwater crabs, Pseudothelphusa americana in constant darkness (DD), constant light (LL) and different light-dark (LD) protocols. Bimodal rhythms were typically observed in this crab when subjected to DD or LD, with bouts of activity anticipating lights-on and lights-off, respectively. Freerunning circadian rhythms were expressed in both DD and LL for longer than 30 days. In DD, we observed that some animals presented different period lengths for each activity component. During LL, activity was primarily unimodal, however spontaneous splitting of the rhythms were observed in some animals. When activity was recorded under artificial long days, the morning bouts maintained their phase relationship but the evening bouts changed their phase relationship with the Zeitgeber. Our results indicate that, bimodal locomotor activity rhythm in the crab Pseudothelphusa americana is variable among organisms. The characteristics of phase relationship with LD and responses to LL for morning and evening bouts, suggest that, locomotor activity could be driven by multiple oscillators, and that coupling between these oscillators may be regulated by light. 相似文献
10.
Melissa Piper Hunter Noura Ismail Xiaoli Zhang Baltazar D. Aguda Eun Joo Lee Lianbo Yu Tao Xiao Jeffrey Schafer Mei-Ling Ting Lee Thomas D. Schmittgen S. Patrick Nana-Sinkam David Jarjoura Clay B. Marsh 《PloS one》2008,3(11)