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141.
Lima G Furuzawa-Carballeda J Ramos-Bello D Jakez-Ocampo J Pascual-Ramos V Núñez-Alvarez CA Granados J Llorente L 《European cytokine network》2012,23(2):25-28
The aim of this study was to investigate the possible role of the CCR5 59029 A→G promoter point mutation polymorphism in determining the susceptibility to rheumatoid factor-positive and rheumatoid factor-negative rheumatoid arthritis. This polymorphism was assessed in 85 seropositive and 39 seronegative rheumatoid arthritis patients and in 126 healthy individuals of the same geographic and ethnic origin. We found an increase in the genetic frequency of the A allele in the 59029 A→G promoter region of the CCR5 receptor in patients with rheumatoid arthritis compared with healthy controls (p = 0.01; OR = 1.5, 95% CI (1.0-2.2). Likewise, the homozygous state for the A allele was found to be more frequent in rheumatoid arthritis patients, again when compared with healthy controls (p = 0.03; OR = 1.8, 95% CI 1.0-3.0). The increased frequency of the A allele was more evident in the more benign, seronegative rheumatoid arthritis group when compared with controls (p = 0.003; OR 2.4 95% CI 1.3-4.4), and when combining the A homozygous and the AG heterozygous patients compared with healthy subjects. These results suggest that this CCR5 promoter polymorphism seems to play an important role in determining different clinical courses in both forms of rheumatoid arthritis. 相似文献
142.
Objectives
Social networks influence the spread of depression, health behaviors, and obesity. The social networks of older urban-dwelling adults were examined to assess whether physical inactivity mediated the association between social networks and obesity.Methods
Data come from the Montreal Neighborhood Networks and Healthy Aging study (n = 2707). Self-reported height and weight were used to calculate body mass index (BMI) with obesity defined as a BMI≥30. A name generator/interpreter instrument was used to elicit participants’ core ties (i.e., alters), and assess whether alters exercised regularly and resided in participants’ neighborhoods. The International Physical Activity Questionnaire was used to measure physical inactivity. Separate multilevel logistic regression analyses were conducted for younger (18–54 years) and older (55 years plus) age groups to examine the association between the exercising behavior of alters and obesity. Ancillary analyses examined whether the residential location of alters was associated with obesity. Mediation analyses assessed whether physical inactivity mediated the association between alter exercising behavior and obesity. Models adjusted for participant socio-demographic and -economic characteristics.Results
Among the older age stratum (55 years plus), physically inactive individuals were more likely obese (OR 2.14; 95% CIs: 1.48–3.10); participants who had more exercising alters were less likely obese (OR: 0.85; 95% CIs: 0.72–0.99). Physical inactivity mediated the association between exercising alters and obesity. Ancillary analyses showed that having exercising alters in the neighborhood compared to other locations tended to reduce the odds of obesity.Conclusion
This work demonstrates the importance of social networks among older adults in facilitating a physically active lifestyle and reducing the odds of obesity. Such findings can inform the design of public health interventions that seek to improve the environmental conditions supporting the physical activity of older adults. 相似文献143.
Melissa Baraket Brian GG Oliver Janette K Burgess Sam Lim Gregory G King Judith L Black 《Respiratory research》2012,13(1):11
Background
While most of the clinical benefits of inhaled corticosteroid (ICS) therapy may occur at low doses, results of dose-ranging studies are inconsistent. Although symptom/lung function response to low and high dose ICS medication is comparable, it is uncertain whether low dose ICSs are as effective as high dose in the treatment of inflammation and remodeling.Methods
22 mild or moderate asthmatic adult subjects (corticosteroid free for > 2 months) participated in a randomized, parallel group study to compare effects of fluticasone propionate (FP) 200 mcg/day and 1000 mcg/day. Alveolar macrophage (AM)-derived cytokines and basement membrane thickness (BMT) were measured at baseline and after 7 weeks treatment while symptoms, spirometry, exhaled nitric oxide (eNO) and airway hyperresponsiveness (AHR) to mannitol at baseline and 6 weeks.Results
FP improved spirometry, eNO, symptoms and AHR with no difference between low and high dose FP. Both high and low dose FP reduced GM-CSF, TNF-alpha and IL-1ra, with no change in BMT and with no differences between low and high dose FP.Conclusions
200 μg/day of FP was as effective as 1000 μg/day in improving asthma control, airway inflammation, lung function and AHR in adults in the short term. Future studies should examine potential differential effects between low and high dose combination therapy (ICS/long acting beta agonist) on inflammation and airway remodeling over longer treatment periods. 相似文献144.
Shekar Kiran Roberts Jason A Welch Susan Buscher Hergen Rudham Sam Burrows Fay Ghassabian Sussan Wallis Steven C Levkovich Bianca Pellegrino Vin McGuinness Shay Parke Rachael Gilder Eileen Barnett Adrian G Walsham James Mullany Daniel V Fung Yoke L Smith Maree T Fraser John F 《BMC anesthesiology》2012,12(1):1-9
145.
The up-regulation of secondary metabolic pathways following herbivore attack and the subsequent reduction in herbivore performance have been identified in numerous woody plant species. Eucalypts constitutively express many secondary metabolites in the leaves, including terpenes and formylated phloroglucinol compounds (FPCs). We used clonal ramets from six clones of Eucalyptus grandis and two clones of E. grandis x camaldulensis to determine if methyl jasmonate (MeJA) treatment could induce changes in the foliar concentrations of either of these groups of compounds. We also used bioassays to determine if any changes in the performance of larvae of Paropsis atomaria, a chrysomelid leaf beetle, could be detected in treated ramets versus the untreated controls, thus indicating whether MeJA induced the up-regulation of defences other than terpenes or FPCs. We found no significant effects of MeJA treatment on either the foliar concentrations of terpenes and FPCs or on herbivore performance. We did, however, detect dramatic differences in larval performance between Eucalyptus clones, thereby demonstrating large variations in the levels of constitutive defence. Larval feeding on clones resistant to P. atomaria resulted in high first instar mortality and disruption of normal gregarious feeding behaviour in surviving larvae. Histological examination of larvae feeding on a resistant clone revealed damage to the midgut consistent with the action of a toxin. These findings concur with mounting evidence that most evergreen perennial plants lack foliar-induced defences and suggest that constitutively expressed secondary metabolites other than those commonly examined in studies of interactions between insect herbivores and Eucalyptus may be important in plant defence. 相似文献
146.
Many regard the concentrations of nitrogen (N), tannins and plant cell wall constituents (fibre) as key indicators of food
quality and habitat suitability for browsing herbivores; yet there is no method for measuring their combined effects. We have
developed a simple in vitro assay for measuring the effects of tannins and fibre on N availability in browse. We determined
the effects of tannins by measuring the polyethylene glycol (PEG)-binding capacity (PEG-BC) of Eucalyptus leaf samples, followed by a two-stage in vitro digestion with pepsin and cellulase to determine the digestibility of dry
matter and N. There was a significant relationship between concentrations of digestible N and the PEG-BC of the leaves. Furthermore,
adding PEG significantly improved the digestibility of N. Our results concur with in vivo observations from several mammalian
species. This suggests that our method is effective for measuring the nutritional quality of browse and the benefits of adding
PEG, providing some index of the detrimental effects of tannins. We further simplified the assay by removing the PEG step,
allowing us to quickly analyse samples in bulk. Nevertheless, this simplified method is still not practical for analysing
the many samples necessary to compare the nutritional values of different tracts of forest. We used near-infrared reflectance
spectroscopy to produce calibration equations and predicted total and digestible N in 322 trees at eleven sites. Both within
and between sites, we found a wide variation in concentrations of digestible N but a much lower variation in total N, with
either no relationship or poor relationships between the two measures. This confirms the variability in the nutritional quality
of eucalypt forests, which may explain the distribution and abundance of mammalian herbivores. Thus, our assay provides a
useful tool for understanding how food resources influence herbivore populations at different scales.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
147.
Mark Lazarev Janette Lamb M Michael Barmada Feng Dai Michelle A Anderson Mitchell B Max David C Whitcomb 《Molecular pain》2008,4(1):1-8
Although a variety of industrial chemicals, as well as several chemotherapeutic agents used to treat cancer or HIV, preferentially induce a peripheral sensory neuropathy what remains unclear is why these agents induce a sensory vs. a motor or mixed neuropathy. Previous studies have shown that the endothelial cells that vascularize the dorsal root ganglion (DRG), which houses the primary afferent sensory neurons, are unique in that they have large fenestrations and are permeable to a variety of low and high molecular weight agents. In the present report we used whole-mount preparations, immunohistochemistry, and confocal laser scanning microscopy to show that the cell body-rich area of the L4 mouse DRG has a 7 fold higher density of CD31+ capillaries than cell fiber rich area of the DRG or the distal or proximal aspect of the sciatic nerve. This dense vascularization, coupled with the high permeability of these capillaries, may synergistically contribute, and in part explain, why many potentially neurotoxic agents preferentially accumulate and injure cells within the DRG. Currently, cancer survivors and HIV patients constitute the largest and most rapidly expanding groups that have chemically induced peripheral sensory neuropathy. Understanding the unique aspects of the vascularization of the DRG and closing the endothelial fenestrations of the rich vascular bed of capillaries that vascularize the DRG before intravenous administration of anti-neoplastic or anti-HIV therapies, may offer a mechanism based approach to attenuate these chemically induced peripheral neuropathies in these patients. 相似文献
148.
1. Ephemeral wetland habitats provide a useful model system for studying how life‐history patterns enable populations to persist despite high environmental variation. One important life‐history trait of both plants and crustaceans in such habitats involves hatching/germination of only some of the eggs/seeds at any time. This bet‐hedging leads to the development of a bank composed of dormant propagules of many ages. 2. The San Diego fairy shrimp, Branchinecta sandiegonensis (Crustacea: Anostraca), a dominant faunal element of ephemeral ponds in San Diego, California, is a suitable organism for studying the consequences of highly fluctuating environmental conditions. As a result of large‐scale habitat loss, the species is also endangered, and this motivated our specific study towards understanding the hatching dynamics of its egg bank for planning conservation efforts such as pool restoration and re‐creation. 3. We formulated a matrix population model using egg age within the bank to study the relationship between adult survival and reproduction, and survival in and hatching from the egg bank. As vital rates for fairy shrimp are only poorly known, we generated 48 matrices with parameters encompassing ranges of likely values for the vital rates of B. sandiegonensis. We calculated population growth rates and eigenvalue elasticities both for a static model and a model with periodic reproductive failure. 4. The model shows that in good filling events, population growth rate is very high and the egg bank is increased dramatically. While population growth rate is insensitive to long‐term survival in the egg bank in our static deterministic model, it becomes sensitive to survival in the egg bank when a regime of periodically failed reproductive events is imposed. 5. Under favourable conditions, it was best for shrimp to hatch from eggs as soon as possible. However, under a regime where failed reproductive events were common, it was best to hatch after several pool fillings. Because conditions change from favourable to unfavourable unpredictably, variation in age within the egg bank appears to be critical for the persistence of the population. This attribute needs to be carefully considered when restoring or creating new pools for conservation purposes. 相似文献
149.
Previous work has suggested that a major contributor to neuronal cell death is the aberrant induction of the cell cycle process, as indicated by an up-regulation of cyclin D. In order to examine the temporal and spatial relationship of cyclin D in a model of acute neurodegeneration, the hippocampal toxicant, trimethyltin (TMT; 2.0 mg/kg), was administered to 21-day old CD−1 male mice and the level and cellular localization of cyclin D1 examined. Within 24 h following TMT, dentate granule cells of the hippocampus showed evidence of neuronal necrosis resulting in severe cell loss over a 3-day period. The pyramidal cell layer was spared with only sparse punctate neuronal necrosis. Microglia response was seen at 72 h with ameboid microglia present in the dentate and ramified microglia present in the pyramidal cell layer, contributing to the elevation seen in TNF-alpha mRNA levels. A transient elevation was seen in mRNA levels for cyclin D1 over 48–72 h post-TMT. Immunohistochemistry demonstrated a transient increase in staining for cyclin D1 in CA1 pyramidal neurons as early as 24 h. Punctate staining occurred in neurons throughout the dentate at 48 h. BrdU positive cells were present along the inner blades of the dentate in control animals. Following TMT exposure, an increase was seen in both the number of neurons stained and a diffusion of the staining pattern into the full dentate region. Thus, in TMT-induced neurodegeneration, cyclin D1 is not expressed in the vulnerable neurons but rather in neurons spared from degeneration. This expression pattern appears to not be linked to an increase in the cellular processes for proliferation as the majority of BrdU positive cells were present in the region of neuronal damage. 相似文献
150.
Robyn M. Sutherland Joanne N. Mountford Janette Allison Leonard C. Harrison Andrew M. Lew 《Experimental diabetes research》2002,3(1):37-45
Chemically-induced diabetic mice and spontaneously
diabetic NOD mice have been valuable
as recipients for experimental islet transplantation.
However, their maintenance often
requires parenteral insulin. Diabetogenic chemicals
can be cytotoxic to the host’s immune system
and to other organs some of which are
often used as the transplant site. Procurement
of diabetic cohorts in the NOD mouse is problematic
due to variability in the age of disease
onset. We show that RIP-Kb mice, which spontaneously
develop non-immune diabetes due to
over-expression of the H-2Kb heavy chain in
beta cells, offer many advantages as islet transplant
recipients. Diabetes is predictable with a
relatively narrow range of onset (4 wk) and
blood glucose levels (23.0± 4.0 mmol/l for 39
males at 6 weeks of age). The diabetes is mild enough so that most diabetic mice can be maintained
to 40 weeks of age without parenteral
insulin. This consistency of diabetes avails that
outcomes of intervention can be interpreted
with confidence. 相似文献