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731.
J A Camilli S M Dias A M Orsi M J Viotto C A Vincentini 《Gegenbaurs morphologisches Jahrbuch》1989,135(4):567-572
The respiratory organ of Electrophorus electricus is located in the oral cavity and is formed by papillar structures. The papilla consists basically of a cartilaginous central nucleus and is bounded by a connective layer. The results reveal structural adaptations for the respiration among fishes which have efficient respiratory circulation related with the venous blood. 相似文献
732.
Species range shifts and expansion are subjects of primary research interest in the context of climate warming and biological invasions. Few studies have focused on reexpansion of species that suffered severe declines. Here, we focused on population recovery of Eurasian otters (Lutra lutra) in Italy, first detected in 2003 after a southward range contraction. We modeled the rate of range expansion and occupancy at the northern expanding front (central Italy), to gain insights into the progress of recovery and mechanisms of reexpansion. We performed a field survey in 2021, which redefined the northern limit of distribution further north, in close proximity to the Gran Sasso National Park. Then we analyzed a time series (1985–2021) of distances of northernmost occurrences from the center of the 1985 range. Using segmented regression, we were able to identify a prolonged stasis of the northern range edge and a simultaneous increase in occupancy from 0.151 to 0.4. A breakpoint was estimated in 2006, after which the range expanded northwards at an average rate of 5.48 km/year. From 2006 to 2021, the overall northward shift was about 80 km. Occupancy continued to increase until 2019 and abruptly declined in 2021. These patterns suggest that the reexpansion of the range can be limited by low occupancy at the expanding front. As occupancy increases, long-distance dispersal increases and then range expands. The low occupancy at the current distribution limit of otters may reflect a higher anthropogenic pressure on northern habitats, which could slow down the reexpansion process. 相似文献
733.
734.
Yanfang Guo Malia S.Q. Murphy Erica Erwin Romina Fakhraei Daniel J. Corsi Ruth Rennicks White Alysha L.J. Harvey Laura M. Gaudet Mark C. Walker Shi Wu Wen Darine El-Char 《CMAJ》2021,193(18):E634
BACKGROUND:Data on the effect of cesarean delivery on maternal request (CDMR) on maternal and neonatal outcomes are inconsistent and often limited by inadequate case definitions and other methodological issues. Our objective was to evaluate the trends, determinants and outcomes of CDMR using an intent-to-treat approach.METHODS:We designed a population-based retrospective cohort study using data on low-risk pregnancies in Ontario, Canada (April 2012–March 2018). We assessed temporal trends and determinants of CDMR. We estimated the relative risks for component and composite outcomes used in the Adverse Outcome Index (AOI) related to planned CDMR compared with planned vaginal delivery using generalized estimating equation models. We compared the Weighted Adverse Outcome Score (WAOS) and the Severity Index (SI) across planned modes of delivery using analysis of variance.RESULTS:Of 422 210 women, 0.4% (n = 1827) had a planned CDMR and 99.6% (n = 420 383) had a planned vaginal delivery. The prevalence of CDMR remained stable over time at 3.9% of all cesarean deliveries. Factors associated with CDMR included late maternal age, higher education, conception via in vitro fertilization, anxiety, nulliparity, being White, delivery at a hospital providing higher levels of maternal care and obstetrician-based antenatal care. Women who planned CDMR had a lower risk of adverse outcomes than women who planned vaginal delivery (adjusted relative risk 0.42, 95% confidence interval [CI] 0.33 to 0.53). The WAOS was lower for planned CDMR than planned vaginal delivery (mean difference −1.28, 95% CI −2.02 to −0.55). The SI was not statistically different between groups (mean difference 3.6, 95% CI −7.4 to 14.5).Interpretation:Rates of CDMR have not increased in Ontario. Planned CDMR is associated with a decreased risk of short-term adverse outcomes compared with planned vaginal delivery. Investigation into the long-term implications of CDMR is warranted.Cesarean delivery is the most common inpatient surgical procedure in North America,1,2 where rates often exceed World Health Organization recommendations (10%–15% of deliveries).3 Given the financial and resource implications of cesarean deliveries on health care systems, the contribution of cesarean deliveries on maternal request (CDMR) to rising cesarean section rates is of ongoing interest. Women may prefer CDMR for many reasons, including scheduling convenience, anxiety regarding labour pain, perceptions that the quality of obstetrical care is better for women who have cesarean deliveries, and concerns about possible urinary incontinence and sexual dysfunction after vaginal delivery.4–7 Challenges in characterizing the epidemiology of CDMR include the lack of internationally accepted case definitions and inconsistencies in documentation that hinder meaningful comparisons across jurisdictions.8–11 In Canada, the prevalence of CDMR has been estimated at 2% of cesarean deliveries,12 but robust contemporary data are lacking.The benefits of vaginal delivery are well known and include a lower risk of transient tachypnea of the newborn, newborn exposure to the vaginal microbiome, shorter maternal hospital stays and lower risk of complications associated with abdominal surgeries. The findings of 1 Canadian study suggest that midpelvic operative vaginal delivery is associated with a greater risk of severe birth and obstetric trauma than cesarean delivery.13 Evidence on the risks and benefits of CDMR is sparse, and existing data are inconsistent.14–19 Analyses are frequently limited by inadequate case definitions and unaddressed confounding from baseline maternal and neonatal factors.4,11 Professional organizations in the United States, Canada and Europe do not recommend CDMR over vaginal delivery.11,20–22 Patient counselling is suggested to inform patients of pain management options, and of potential benefits and harms related to cesarean deliveries. However, obstetrical care providers often accede to patient preferences, given the ethical imperative of patient autonomy. 23–27 Contemporary, high-quality observational studies leveraging robust population-based data are required. Our objective was to evaluate the trends, determinants and outcomes of CDMR compared with planned vaginal delivery using an intent-to-treat approach. 相似文献
735.
736.
Raul O Gonzalez Leticia H Higa Romina A Cutrullis Marcos Bilen Irma Morelli Diana I Roncaglia Ricardo S Corral Maria Jose Morilla Patricia B Petray Eder L Romero 《BMC biotechnology》2009,9(1):71
Background
Archaeosomes (ARC), vesicles prepared from total polar lipids (TPL) extracted from selected genera and species from the Archaea domain, elicit both antibody and cell-mediated immunity to the entrapped antigen, as well as efficient cross priming of exogenous antigens, evoking a profound memory response. Screening for unexplored Archaea genus as new sources of adjuvancy, here we report the presence of two new Halorubrum tebenquichense strains isolated from grey crystals (GC) and black mood (BM) strata from a littoral Argentinean Patagonia salt flat. Cytotoxicity, intracellular transit and immune response induced by two subcutaneous (sc) administrations (days 0 and 21) with BSA entrapped in ARC made of TPL either form BM (ARC-BM) and from GC (ARC-GC) at 2% w/w (BSA/lipids), to C3H/HeN mice (25 μg BSA, 1.3 mg of archaeal lipids per mouse) and boosted on day 180 with 25 μg of bare BSA, were determined. 相似文献737.
738.
Freshwater species with small distribution ranges are vulnerable to extinction, especially when they exhibit small effective
population sizes. Squalius torgalensis, Cyprinidae, is an endemic critically endangered fish species from southwestern Portugal, confined to the intermittent streams
of the Mira drainage. Assessment of genetic diversity and population structure levels was conducted through the analysis of
both mitochondrial (cytochrome b) and nine nuclear microsatellite markers. Remarkable low levels of genetic diversity for
both markers were observed (He < 0.38, π < 0.001). These results may be related with the restricted distribution range and dispersion patterns of the species together
with demographic fluctuations associated with the intermittent features of the river system. Population structure analyses
suggest the existence of two incipient divergent populations; one comprising the tributaries located upstream and the other
comprising downstream tributaries of the Mira River. Data also supports the occurrence of high gene flow mainly from downstream
to upstream, failing to reflect isolation of populations due to seasonal drought. Obtained results should be incorporated
in future management plans for the species. These should be centred around the current connection between populations and
on the maintenance of suitable habitat patches, not only for reproduction, but also for summer refuges. 相似文献
739.
Daniela Stadler Martin Kchele Alisha N Jones Julia Hess Christian Urban Jessica Schneider Yuchen Xia Andreas Oswald Firat Nebioglu Romina Bester Felix Lasitschka Marc Ringelhan Chunkyu Ko WenMin Chou Arie Geerlof Maarten A van de Klundert Jochen M Wettengel Peter Schirmacher Mathias Heikenwlder Sabrina Schreiner Ralf Bartenschlager Andreas Pichlmair Michael Sattler Kristian Unger Ulrike Protzer 《EMBO reports》2021,22(6)