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621.
Suter-Widmer IE Christ-Crain M Zimmerli W Albrich W Mueller B Schuetz P 《BMC pulmonary medicine》2012,12(1):21
ABSTRACT: BACKGROUND: Length of hospital stay (LOS) in patients with community-acquired pneumonia (CAP) is variable and directly related to medical costs. Accurate estimation of LOS on admission and during follow-up may result in earlier and more efficient discharge strategies. METHODS: This is a prospective multicenter study including patients in emergency departments of 6 tertiary care hospitals in Switzerland between October 2006 and March 2008. Medical history, clinical data at presentation and health care insurance class were collected. We calculated univariate and multivariate cox regression models to assess the association of different characteristics with LOS. In a split sample analysis, we created two LOS prediction rules, first including only admission data, and second including also additional inpatient information. RESULTS: The mean LOS in the 875 included CAP patients was 9.8 days (95%CI 9.3-10.4). Older age, respiratory rate >20pm, nursing home residence, chronic pulmonary disease, diabetes, multilobar CAP and the pneumonia severity index class were independently associated with longer LOS in the admission prediction model. When also considering follow-up information, low albumin levels, ICU transfer and development of CAP-associated complications were additional independent risk factors for prolonged LOS. Both weighted clinical prediction rules based on these factors showed a high separation of patients in Kaplan Meier Curves (p logrank <0.001 and <0.001) and a good calibration when comparing predicted and observed results. CONCLUSIONS: Within this study we identified different baseline and follow-up characteristics to be strong and independent predictors for LOS. If validated in future studies, these factors may help to optimize discharge strategies and thus shorten LOS in CAP patients. 相似文献
622.
Sjoerd P Niehof Frank JPM Huygen Rick WP van der Weerd Mirjam Westra Freek J Zijlstra 《Biomedical engineering online》2006,5(1):30
Background
Complex Regional Pain Syndrome type 1 (CRPS1) is a clinical diagnosis based on criteria describing symptoms of the disease. 相似文献623.
Understanding patterns and motivations for social spacing greatly illuminates the structure and internal dynamics of given
groups or social systems. The highly social, polygynous greater sac-winged bat, Saccopteryx bilineata, represents an excellent model for social spacing analysis, since the choice of individual roost-sites within a day-roost
constitutes an enduring, often repeated decision about relative proximity to conspecifics. Day-roost colonies consist of one
or multiple harem groups, each with several females and a single male. Additionally, non-harem males without females may be
present. A social-distance–time-budget metric revealed that harem males, females, and non-harem males differed significantly
in their respective spatial associations while roosting. Harem males and females were most closely associated, with harem
males located at the center of harems instead of at the borders. Non-harem males associated significantly closer with one
another than with harem females that they were trying to access. The signaling modality mediating social interactions depended
on the respective social distances between communicating bats. Our results suggest a concentric social organization based
around harem males, which may select roost sites in closest possible proximity to females to enhance courtship signal strength.
This constitutes an interesting deviation from the normative form of harem maintenance, patrolling borders, in mammals. 相似文献
624.
The dynamics of host–parasite interactions depend to a large extent on the effect of host responses on parasite fitness. Exposure to parasites may induce behavioural or physiological responses in hosts that may reduce the subsequent survival or reproductive output of the parasite. Neonate hosts may further directly obtain immunologically active substances from their mother, for instance via milk in mammals or egg yolk in birds. However, the relative importance of maternally‐derived and self‐generated responses in inducing parasite resistance is poorly understood, especially in free‐living vertebrates. Here we investigate the complementary effect of experimentally induced maternal and neonate responses in great tit (Parus major) hosts on the reproductive success of their common ectoparasite, the hen flea (Ceratophyllus gallinae). In the laboratory we measured the number of eggs and larvae produced by individual flea females collected from host nests. In addition, the total number of larvae produced by an experimentally set number of flea females in the host's nestbox was assessed under field conditions. There was no indication of maternally‐transferred parasite resistance, since exposing the mother to fleas during the laying period did not affect the reproductive rate of fleas exploiting her offspring early or late in the nestling cycle. Independent of the maternal treatment, exposure of neonates to fleas early in the nestling period reduced the reproductive output of fleas late in the nestling cycle. The effect of the induced nestling response was seasonal, reducing flea reproduction in nests of early‐breeding hosts but not in nests of late‐breeding ones. Larvae production in the nestbox and in the laboratory was positively correlated, but under natural conditions the neonate response did not affect the size of the flea larvae population. Our results indicate induced responses as a means by which neonate avian hosts resist ectoparasites. Other factors, such as the environmental temperature and density‐dependent larval competition, may be more important in determining the size of the future parasite populations. 相似文献
625.
Responses to low salinity by the sea star Pisaster ochraceus from high‐ and low‐salinity populations
Abstract. In many coastal environments, variation in salinity and organismal responses to that variation are important determinants of the distribution and abundance of species. This study examined the effects of acute salinity changes on sea stars (Pisaster ochraceus) collected from a high‐salinity site (Bamfield, BC) and a low‐salinity site (Vancouver, BC). Sea stars from both sites were exposed to salinities ranging 15–30 psu. Following a 24‐h exposure, the osmolality, sodium concentrations, and chloride concentrations in the perivisceral fluid all varied directly with salinity and were very close to the treatment salinities in both the Bamfield and Vancouver sea stars. The righting response (measured as an activity coefficient) was salinity dependent, with the lowest activity levels at a salinity of 15 psu. Activity coefficients did not vary between the two source populations. Feeding rates on mussels were strongly salinity dependent, but the salinity pattern was population specific. Bamfield sea stars fed the most at 30 psu, whereas Vancouver sea stars fed the most at 20 psu. High post‐experimental mortalities were observed in Bamfield sea stars that had been exposed to a salinity of 15 psu; no such mortality was observed in Vancouver animals. This study provides evidence that the sea stars from the lower salinity environment had been able to acclimatize or adapt to low‐salinity conditions. However, the results also suggest that there are limits to this tolerance, and that future changes in salinity may have important consequences for marine communities via alteration of keystone predation. 相似文献
626.
Mirjam Pijnappels Maarten F Bobbert Jaap H van Die?n 《Journal of electromyography and kinesiology》2006,16(2):137-143
This study investigated whether changes in lower limb muscle activity occurred in anticipation of a possible perturbation in 11 young (mean age 27 years) and 11 older (mean age 68 years) adults. Altered muscle activity could affect tripping responses and consequently the ecological validity of experimental results of studies on tripping. It was hypothesized that anticipatory muscle activity would be present immediately after a trip, and decrease after several subsequent unperturbed (forewarned) walking trials. Electromyograms of lower limb muscles were measured in 3 conditions: during normal walking, during forewarned walking immediately after a trip, and during forewarned walking several trials after a trip had occurred. Small but statistically significant differences in averaged muscle activity over a stride were found among conditions. Young adults showed slightly increased activity immediately after tripping (co-contraction) in hamstrings, quadriceps and tibialis anterior muscles. This increased activity diminished after several unperturbed trials, although it did not return to the baseline activity levels during normal walking. In older adults, an increased muscle activity among conditions was only discerned in tibialis anterior and soleus muscles. This suggested that older adults prefer to avoid contact with the obstacle over joint stiffening. Yet, for both age-groups, the increases in muscle activity were very small when compared to tripping responses reported in the literature. Therefore, anticipatory effects are not expected to jeopardize the validity of experiments in which subjects are perturbed more than once. 相似文献
627.