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1.
Aging is associated with reductions in hippocampal volume that are accelerated by Alzheimer's disease and vascular risk factors. Our genome-wide association study (GWAS) of dementia-free persons (n = 9,232) identified 46 SNPs at four loci with P values of <4.0 × 10(-7). In two additional samples (n = 2,318), associations were replicated at 12q14 within MSRB3-WIF1 (discovery and replication; rs17178006; P = 5.3 × 10(-11)) and at 12q24 near HRK-FBXW8 (rs7294919; P = 2.9 × 10(-11)). Remaining associations included one SNP at 2q24 within DPP4 (rs6741949; P = 2.9 × 10(-7)) and nine SNPs at 9p33 within ASTN2 (rs7852872; P = 1.0 × 10(-7)); along with the chromosome 12 associations, these loci were also associated with hippocampal volume (P < 0.05) in a third younger, more heterogeneous sample (n = 7,794). The SNP in ASTN2 also showed suggestive association with decline in cognition in a largely independent sample (n = 1,563). These associations implicate genes related to apoptosis (HRK), development (WIF1), oxidative stress (MSR3B), ubiquitination (FBXW8) and neuronal migration (ASTN2), as well as enzymes targeted by new diabetes medications (DPP4), indicating new genetic influences on hippocampal size and possibly the risk of cognitive decline and dementia.  相似文献   
2.
We used retrospective analyses to investigate cause-specific mortality and survivorship among 5 populations of mule deer ( N = 168 telemetered animals) wintering in the western Great Basin during 1986-1994. These populations existed under similar environmental conditions, but survivorship functions differed among them. Monthly survival ranged from 0.964 to 0.990, and annual survival ranged from 0.643 to 0.884. The proportion of deaths attributed to predation and malnutrition or anthropogenic causes did not differ among the 5 populations. Predation was the leading cause of mortality; mountain lions were responsible for approximately 90% of the deer killed by predators. No difference existed among these populations in the proportion of telemetered deer that were killed by mountain lions, but proportionally more females than males were killed by these large fields. Predation by mountain lions is the primary source of mortality and a widespread phenomenon among the populations of mule deer we investigated.  相似文献   
3.
Weight loss was rapid and fluid consumption decreased sharply when Onychomys torridus were exposed to salinities greater than 0.3 Molar. The southern grasshopper mouse is physiologically unspecialized for maintaining water balance in its xeric habitat. The southern grasshopper mouse is capable of weight maintenance on smaller daily water rations than is the northern grasshopper mouse ( Onychomys leucogaster ) . Differences in the water balance of O. torridus and O. leucogaster may influence their local distributions in areas of sympatry.  相似文献   
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Zusammenfassung Durch Inkorporation von14C-Methionin in die Corpora allata vonPeriplaneta americana werden während des Eireifungszyklus zwei Aktivitätsmaxima festgestellt und diese als Juvenilhormonsynthese interpretiert.  相似文献   
6.
T Watanabe  R M Pratt 《Experientia》1991,47(5):493-497
The effects of all-trans-retinoic acid (RA) (tretinoin) on the craniofacial development of mouse embryos were examined using whole embryo culture. In day 8 embryos cultured for 48 h, embryonic growth was inhibited concentration-dependently by all-trans-RA treatment. Most of the treated embryos exhibited hypoplasia of the primary palatal processes and a reduction in the development of the first visceral arches. In day 10 embryos cultured for 48 h, although embryonic growth was not inhibited at any concentrations of all-trans-RA, median cleft lip (93%), hypoplasia of the primary palatal processes (37%) and limb reduction deformities (48%) occurred commonly. Furthermore, RA treatment greatly reduced the size of the secondary palatal processes. The incorporation of 3H-thymidine in the treated maxillary processes was decreased to 65% of the control value at 1.0 x 10(-7) M all-trans-RA. These findings indicate that all-trans-RA is teratogenic in mouse whole embryo culture.  相似文献   
7.
Distribution and immunology of mammalian nerve growth factor   总被引:2,自引:0,他引:2  
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8.
Zusammenfassung Es wird die Anwendung eines quantitativen Fluoreszenz-Präzipitin-Tests für Adenovirus-Antigene beschrieben. Die Methode wurde für 11 verschiedene Adenoviren angewendet und hat sich als relativ typenspezifisch erwiesen.

This investigation was supported in part by contract PH43-63-80 from the National Institutes of Health.  相似文献   
9.
Beninger RJ  Quinsey VL 《Nature》2006,440(7085):E6; discussion E6
Silk et al. report that adult chimpanzees show no difference in their choices in a situation where one choice benefits a familiar conspecific and the other does not. From this, they conclude that chimpanzees are indifferent to the welfare of unrelated group members. But without additional data confirming that chimpanzees do choose differently in circumstances in which a difference would be expected, the authors cannot conclude that there is no difference in their scenario. How chimpanzees react to the welfare of unrelated group members remains an open question.  相似文献   
10.
DNA sequence information underpins genetic research, enabling discoveries of important biological or medical benefit. Sequencing projects have traditionally used long (400-800 base pair) reads, but the existence of reference sequences for the human and many other genomes makes it possible to develop new, fast approaches to re-sequencing, whereby shorter reads are compared to a reference to identify intraspecies genetic variation. Here we report an approach that generates several billion bases of accurate nucleotide sequence per experiment at low cost. Single molecules of DNA are attached to a flat surface, amplified in situ and used as templates for synthetic sequencing with fluorescent reversible terminator deoxyribonucleotides. Images of the surface are analysed to generate high-quality sequence. We demonstrate application of this approach to human genome sequencing on flow-sorted X chromosomes and then scale the approach to determine the genome sequence of a male Yoruba from Ibadan, Nigeria. We build an accurate consensus sequence from >30x average depth of paired 35-base reads. We characterize four million single-nucleotide polymorphisms and four hundred thousand structural variants, many of which were previously unknown. Our approach is effective for accurate, rapid and economical whole-genome re-sequencing and many other biomedical applications.  相似文献   
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