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101.
Ancient DNA from Nubian and Somali wild ass provides insights into donkey ancestry and domestication
Birgitta Kimura Fiona B. Marshall Shanyuan Chen Sónia Rosenbom Patricia D. Moehlman Noreen Tuross Richard C. Sabin Joris Peters Barbara Barich Hagos Yohannes Fanuel Kebede Redae Teclai Albano Beja-Pereira Connie J. Mulligan 《Proceedings. Biological sciences / The Royal Society》2011,278(1702):50-57
Genetic data from extant donkeys (Equus asinus) have revealed two distinct mitochondrial DNA haplogroups, suggestive of two separate domestication events in northeast Africa about 5000 years ago. Without distinct phylogeographic structure in domestic donkey haplogroups and with little information on the genetic makeup of the ancestral African wild ass, however, it has been difficult to identify wild ancestors and geographical origins for the domestic mitochondrial clades. Our analysis of ancient archaeological and historic museum samples provides the first genetic information on the historic Nubian wild ass (Equus africanus africanus), Somali wild ass (Equus africanus somaliensis) and ancient donkey. The results demonstrate that the Nubian wild ass was an ancestor of the first donkey haplogroup. In contrast, the Somali wild ass has considerable mitochondrial divergence from the Nubian wild ass and domestic donkeys. These findings resolve the long-standing issue of the role of the Nubian wild ass in the domestication of the donkey, but raise new questions regarding the second ancestor for the donkey. Our results illustrate the complexity of animal domestication, and have conservation implications for critically endangered Nubian and Somali wild ass. 相似文献
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103.
Fixation probability for a beneficial allele and a mutant strategy in a linear game under weak selection in a finite island model 总被引:1,自引:1,他引:0
The effect of population structure on the probability of fixation of a newly introduced mutant under weak selection is studied using a coalescent approach. Wright's island model in a framework of a finite number of demes is assumed and two selection regimes are considered: a beneficial allele model and a linear game among offspring. A first-order approximation of the fixation probability for a single mutant with respect to the intensity of selection is deduced. The approximation requires the calculation of expected coalescence times, under neutrality, for lineages starting from two or three sampled individuals. The results are obtained in a general setting without assumptions on the number of demes, the deme size or the migration rate, which allows for simultaneous coalescence or migration events in the genealogy of the sampled individuals. Comparisons are made with limit cases as the deme size or the number of demes goes to infinity or the migration rate goes to zero for which a diffusion approximation approach is possible. Conditions for selection to favor a mutant strategy replacing a resident strategy in the context of a linear game in a finite island population are addressed. 相似文献
104.
A transferable plasticity region in Campylobacter coli allows isolates of an otherwise non‐glycolytic food‐borne pathogen to catabolize glucose
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Hanne Vorwerk Claudia Huber Juliane Mohr Boyke Bunk Sabin Bhuju Olga Wensel Cathrin Spröer Angelika Fruth Antje Flieger Kerstin Schmidt‐Hohagen Dietmar Schomburg Wolfgang Eisenreich Dirk Hofreuter 《Molecular microbiology》2015,98(5):809-830
Thermophilic Campylobacter species colonize the intestine of agricultural and domestic animals commensally but cause severe gastroenteritis in humans. In contrast to other enteropathogenic bacteria, Campylobacter has been considered to be non‐glycolytic, a metabolic property originally used for their taxonomic classification. Contrary to this dogma, we demonstrate that several Campylobacter coli strains are able to utilize glucose as a growth substrate. Isotopologue profiling experiments with 13C‐labeled glucose suggested that these strains catabolize glucose via the pentose phosphate and Entner‐Doudoroff (ED) pathways and use glucose efficiently for de novo synthesis of amino acids and cell surface carbohydrates. Whole genome sequencing of glycolytic C. coli isolates identified a genomic island located within a ribosomal RNA gene cluster that encodes for all ED pathway enzymes and a glucose permease. We could show in vitro that a non‐glycolytic C. coli strain could acquire glycolytic activity through natural transformation with chromosomal DNA of C. coli and C. jejuni subsp. doylei strains possessing the ED pathway encoding plasticity region. These results reveal for the first time the ability of a Campylobacter species to catabolize glucose and provide new insights into how genetic macrodiversity through intra‐ and interspecies gene transfer expand the metabolic capacity of this food‐borne pathogen. 相似文献
105.
Sorin Comorosan Wilhelm Kappel Ileana Constantinescu Marin Gheorghe Elena Ionescu Cristian Pîrvu Sabin Cinca Ligia Cristache 《Journal of biological physics》2009,35(3):265-277
This paper reports a new phenomenon connected with the influence of green light (GL) on biological systems. Our experiments
have revealed an antioxidant effect of GL on cells subjected to lethal doses of UV at the cellular level and a protective
effect of GL on DNA denatured by UV, coupled with a structural modification of DNA macromolecules under GL irradiation, at
the molecular level. Mouse melanocyte cultures are subjected to UV irradiations with L50 fluxes of 16.0 J m − 2 s − 1. GL is obtained from a strontium aluminate pigment, which emits GL under UV activation. Cells grown in GL, prior to UV irradiation,
present a clear surprising protective effect with surviving values close to the controls. A GL antioxidant effect is suggested
to be mediated through GL influence on cellular water cluster dynamics. To test this hypothesis, reactive oxygen species (ROS)
are determined in cell cultures. The results revealed a decrease of cellular ROS generation in the UV-irradiated samples protected
by a previous 24 h of GL irradiation. At the DNA level, the same type of GL protection against UV damage is recorded by gel
electrophoresis and by UV spectroscopy of the irradiated DNA molecules. Two physical methods, impedance spectroscopy and chronoamperometry,
have revealed at the level of GL-irradiated DNA molecules spectral modifications that correlate with the UV spectroscopy results.
The interaction between the chargeless photons and the field of water molecules from the cellular compartments is discussed
in relation with the new field of macroscopic quantum coherence phenomena. 相似文献
106.
Bryce D. Smith Miriam Sabin Elois Ann Berlin Larry Nackerud 《Culture, medicine and psychiatry》2009,33(3):366-381
This survey investigated the prevalence of ethnomedical syndromes and examined treatments and treatment-seeking in Mayan Guatemalans
living in United Nations High Commissioner for Refugee (UNHCR) camps in Chiapas, Mexico. Methods included a rapid ethnographic
assessment to refine survey methods and inform the cross-sectional survey, which also examined mental health outcomes; 183
households were approached for interview, representing an estimated 1,546 residents in five refugee camps and 93% of all households.
One adult per household (N = 170) was interviewed regarding his or her health; an additional 9 adults in three surveyed households participated and
were included in this analysis; of the 179 participants, 95 primary child-care providers also answered a children’s health
questionnaire for their children. Results indicated that ethnomedical syndromes were common in this sample, with 59% of adults
and 48.4% of children having experienced susto (fright condition) and 34.1% of adults reporting ataques de nervios (nervous attacks); both conditions were significantly associated with symptoms consistent with posttraumatic stress disorder,
anxiety and depression and are mental health conditions recognized by the American Psychiatric Association. Combining healthcare
provider and indigenous treatments such as physician prescribed medication (65%), medicinal plants (65.7%), and limpias (spiritual cleansings) (40.6%) was reported. Most participants (86%) sought routine medical treatment from UNHCR trained
health promoters in their camp. Assessing ethnomedical health is important for informing mental health programs among this
population. 相似文献
107.
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109.
Background
The Lufwanyama Neonatal Survival Project (“LUNESP”) was a cluster randomized, controlled trial that showed that training traditional birth attendants (TBAs) to perform interventions targeting birth asphyxia, hypothermia, and neonatal sepsis reduced all-cause neonatal mortality by 45%. This companion analysis was undertaken to analyze intervention costs and cost-effectiveness, and factors that might improve cost-effectiveness.Methods and Findings
We calculated LUNESP''s financial and economic costs and the economic cost of implementation for a forecasted ten-year program (2011–2020). In each case, we calculated the incremental cost per death avoided and disability-adjusted life years (DALYs) averted in real 2011 US dollars. The forecasted 10-year program analysis included a base case as well as ‘conservative’ and ‘optimistic’ scenarios. Uncertainty was characterized using one-way sensitivity analyses and a multivariate probabilistic sensitivity analysis. The estimated financial and economic costs of LUNESP were $118,574 and $127,756, respectively, or $49,469 and $53,550 per year. Fixed costs accounted for nearly 90% of total costs. For the 10-year program, discounted total and annual program costs were $256,455 and $26,834 respectively; for the base case, optimistic, and conservative scenarios, the estimated cost per death avoided was $1,866, $591, and $3,024, and cost per DALY averted was $74, $24, and $120, respectively. Outcomes were robust to variations in local costs, but sensitive to variations in intervention effect size, number of births attended by TBAs, and the extent of foreign consultants'' participation.Conclusions
Based on established guidelines, the strategy of using trained TBAs to reduce neonatal mortality was ‘highly cost effective’. We strongly recommend consideration of this approach for other remote rural populations with limited access to health care. 相似文献110.
Scott A. Shikora Rayford S. Kruger Jr. George L. Blackburn John A. Fallon Alan M. Harvey Elvira Q. Johnson Lee Kaplan Edward C. Mun Stancel Riley Jr. Malcolm K. Robinson James E. Sabin Roger L. Snow Robert LoNigro Lee J. Steingisser David B. Lautz Policy & Access Task Group 《Obesity (Silver Spring, Md.)》2009,17(5):918-923
To update evidence‐based best practice guidelines for coding and reimbursement and establish policy and access standards for weight loss surgery (WLS). Systematic search of English‐language literature on WLS and health‐care policy, access, insurance reimbursement, coding, private payers, public policy, and mandated benefits published between April 2004 and May 2007 in MEDLINE, EMBASE, and the Cochrane Library. Use of key words to narrow the search for a selective review of abstracts, retrieval of full articles, and grading of evidence according to systems used in established evidence‐based models. We identified 51 publications in our literature search; the 20 most relevant were examined in detail. These included reviews, cost‐benefit analyses, and trend and cost studies from administrative databases. Literature on policy issues surrounding WLS are very sparse and largely focused on economic analyses. Reports on policy initiatives in the public and private arenas are primarily limited to narrative reviews of nonsurgical efforts to fight obesity. A substantial body of work shows that WLS improves or reverses most obesity‐related comorbidities. Mounting evidence also indicates that WLS confers a significant survival advantage for those who undergo it. WLS is a viable and cost‐effective treatment for an increasingly common disease, and policy decisions are more frequently being linked to incentives for national health‐care goals. However, access to WLS often varies by payer and region. Currently, there are no uniform criteria for determining patient appropriateness for surgery. 相似文献