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131.
Carvalho W Silva SS Vitolo M Felipe MG Mancilha IM 《Zeitschrift für Naturforschung. C, Journal of biosciences》2002,57(1-2):109-112
Candida guilliermondii cells were immobilized in Ca-alginate beads and used for xylitol production from concentrated sugarcane bagasse hydrolysate during five successive fermentation batches, each lasting 48 hours. The bioconversion efficiency of 53.2%, the productivity of 0.50 g/l x h and the final xylitol concentration of 23.8 g/l obtained in the first batch increased to 61.5%, 0.59 g/l x h and 28.4 g/l, respectively, in the other four batches (mean values), with variation coefficients of up to 2.3%. 相似文献
132.
Iron deficiency changed markedly the shape of the leaf chlorophyll fluorescence induction kinetics during a dark-light transition,
the so-called Kautsky effect. Changes in chlorophyll fluorescence lifetime and yield were observed, increasing largely the
minimal and the intermediate chlorophyll fluorescence levels, with a marked dip between the intermediate and the maximum levels
and loss of the secondary peak after the maximum. During the slow changes, the lifetime-yield relationship was found to be
linear and curvilinear (towards positive lifetime values) in control and Fe-deficient leaves, respectively. These results
suggested that part of the Photosystem II antenna in Fe-deficient leaves emits fluorescence with a long lifetime. In dark-adapted
Fe-deficient leaves, measurements in the picosecond-nanosecond time domain confirmed the presence of a 3.3-ns component, contributing
to 15% of the total fluorescence. Computer simulations revealed that upon illumination such contribution is also present and
remains constant, indicating that energy transfer is partially interrupted in Fe-deficient leaves. Photosystem II-enriched
membrane fractions containing different pigment-protein complexes were isolated from control and Fe-deficient leaves and characterized
spectrophotometrically. The photosynthetic pigment composition of the fractions was also determined. Data revealed the presence
of a novel pigment-protein complex induced by Fe deficiency and an enrichment of internal relative to peripheral antenna complexes.
The data suggest a partial disconnection between internal Photosystem II antenna complexes and the reaction center, which
could lead to an underestimation of the Photosystem II efficiency in dark-adapted, low chlorophyll Fe-deficient leaves, using
chlorophyll fluorescence.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
133.
Ulrich Sinsch Ismael E. Di Tada Adolfo L. Martino 《Studies on Neotropical Fauna and Environment》2013,48(2):95-104
The demography and life history parameters of the neotropical Bufo achalensis, an endemic toad of the Pampa de Achala, Sierras Grandes de Cordoba, Argentina, were studied in 13 activity periods between 1970/71 and 1998/99. We used phalange bones for skeletochronological age estimation and to assess annual growth rates in 243 individuals. Maximum longevity was 11 years, and sexual maturity was attained at an age of 2–4 years. Reproductive females were on average 4–8 mm smaller than males of the same age. There is no indication that the population of B. achalensis is declining as observed in several neotropical amphibian species. 相似文献
134.
135.
Marta Ortega-Muelas Olga Roche Diego M. Fernández-Aroca José A. Encinar David Albandea-Rodríguez Elena Arconada-Luque Raquel Pascual-Serra Ismael Muñoz Isabel Sánchez-Pérez Borja Belandia María J. Ruiz-Hidalgo Ricardo Sánchez-Prieto 《Journal of cellular and molecular medicine》2021,25(22):10591-10603
136.
Antonio González-Martín Amaya Gorostiza Lucía Regalado-Liu Sergio Arroyo-Pe?a Sergio Tirado Ismael Nu?o-Arana Rodrigo Rubi-Castellanos Karla Sandoval Michael D. Coble Héctor Rangel-Villalobos 《PloS one》2015,10(8)
The genetic characterization of Native American groups provides insights into their history and demographic events. We sequenced the mitochondrial D-loop region (control region) of 520 samples from eight Mexican indigenous groups. In addition to an analysis of the genetic diversity, structure and genetic relationship between 28 Native American populations, we applied Bayesian skyline methodology for a deeper insight into the history of Mesoamerica. AMOVA tests applying cultural, linguistic and geographic criteria were performed. MDS plots showed a central cluster of Oaxaca and Maya populations, whereas those from the North and West were located on the periphery. Demographic reconstruction indicates higher values of the effective number of breeding females (Nef) in Central Mesoamerica during the Preclassic period, whereas this pattern moves toward the Classic period for groups in the North and West. Conversely, Nef minimum values are distributed either in the Lithic period (i.e. founder effects) or in recent periods (i.e. population declines). The Mesomerican regions showed differences in population fluctuation as indicated by the maximum Inter-Generational Rate (IGRmax): i) Center-South from the lithic period until the Preclassic; ii) West from the beginning of the Preclassic period until early Classic; iii) North characterized by a wide range of temporal variation from the Lithic to the Preclassic. Our findings are consistent with the genetic variations observed between central, South and Southeast Mesoamerica and the North-West region that are related to differences in genetic drift, structure, and temporal survival strategies (agriculture versus hunter-gathering, respectively). Interestingly, although the European contact had a major negative demographic impact, we detect a previous decline in Mesoamerica that had begun a few hundred years before. 相似文献
137.
Edna Omar Viegas Nelson Tembe Eulália Macovela Emília Gon?alves Orvalho Augusto Nália Ismael Nádia Sitoe Caroline De Schacht Nilesh Bhatt Bindiya Meggi Carolina Araujo Eric Sandstr?m Gunnel Biberfeld Charlotta Nilsson S?ren Andersson Ilesh Jani Nafissa Osman 《PloS one》2015,10(3)
Background
Prevalence of HIV in Mozambique among individuals aged 15–49 years is 11.5%. The HIV prevalence is higher in women than in men across the country, peaking at ages 25–29 years and 35–39 years, respectively. In this study, we aimed at determining the prevalence and incidence of HIV, prevalence of Hepatitis B (HBV), and prevalence of syphilis in youths. We also characterized a cohort of youths for future participation in phase I/II HIV vaccine trials.Methods
The study was conducted at a youth clinic in Maputo Central Hospital from August 2009 to October 2011. Youths of both genders aged 18–24 years (n = 1380) were screened for HIV using a sequential algorithm of two immunochromatographic assays, HBV using an enzyme linked immunosorbant test, and syphilis using a treponemal immunochromatographic strip test. The HIV seronegative participants (n = 1309) were followed-up for 12 months with quarterly study visits. The clinical and behavioral data were collected using structured questionnaires. The HIV seroconversions were confirmed by a molecular assay.Results
The study population was female dominant (76.8%). All participants had a formal education, with 44.6% studying for technical or higher education degrees. The mean age at sexual debut was 16.6 years (SD: ±1.74), with 85.6% reporting more than one sexual partner in life. The screening showed the prevalence of HIV, HBV, and syphilis at 5.1% (95% CI: 3.97–6.31), 12.2% (95% CI 10.5%–14.0%), and 0.36% (95% CI 0.15%–0.84%), respectively. The HIV incidence rate was found to be 1.14/100 person years (95% CI: 0.67–1.92). Retention rates were stable throughout the study being 85.1% at the last visit.Conclusion
Incidence of HIV in this cohort of youths in Maputo was relatively low. Also, the prevalence of HIV and syphilis was lower than the national values in this age group. However, the HBV prevalence was higher than in previous reports in the country. 相似文献138.
Melanins and melanogenesis: from pigment cells to human health and technological applications
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Marco d'Ischia Kazumasa Wakamatsu Fabio Cicoira Eduardo Di Mauro Josè Carlos Garcia‐Borron Stephane Commo Ismael Galván Ghanem Ghanem Koike Kenzo Paul Meredith Alessandro Pezzella Clara Santato Tadeusz Sarna John D. Simon Luigi Zecca Fabio A. Zucca Alessandra Napolitano Shosuke Ito 《Pigment cell & melanoma research》2015,28(5):520-544
During the past decade, melanins and melanogenesis have attracted growing interest for a broad range of biomedical and technological applications. The burst of polydopamine‐based multifunctional coatings in materials science is just one example, and the list may be expanded to include melanin thin films for organic electronics and bioelectronics, drug delivery systems, functional nanoparticles and biointerfaces, sunscreens, environmental remediation devices. Despite considerable advances, applied research on melanins and melanogenesis is still far from being mature. A closer intersectoral interaction between research centers is essential to raise the interests and increase the awareness of the biomedical, biomaterials science and hi‐tech sectors of the manifold opportunities offered by pigment cells and related metabolic pathways. Starting from a survey of biological roles and functions, the present review aims at providing an interdisciplinary perspective of melanin pigments and related pathway with a view to showing how it is possible to translate current knowledge about physical and chemical properties and control mechanisms into new bioinspired solutions for biomedical, dermocosmetic, and technological applications. 相似文献
139.
Carlos Pineda Arturo J Fuentes-Gómez Cristina Hernández-Díaz Yessica Zamudio-Cuevas Javier Fernández-Torres Ambar López-Macay Ismael Alba-Sánchez Javier Camacho-Galindo Lucio Ventura Luis E Gómez-Quiróz María Concepción Gutiérrez-Ruíz Francisco García-Vázquez Anthony M Reginato Marwin Gutiérrez Alberto López-Reyes 《Arthritis research & therapy》2015,17(1)
IntroductionGout is an inflammatory condition induced by the deposition of monosodium urate (MSU) crystals in the joints and soft tissues that can produce acute or chronic arthritis. Several animal models of crystal-induced inflammation have been proposed that involve direct injection of MSU-crystals into different anatomical structures; however, only a few of these models reflect a true diarthrodial joint microenvironment in which an acute gouty attack takes place. The aim of this study was to assess the inflammatory and structural joint changes in a rabbit model of acute gout attack by ultrasound (US), synovial fluid (SF) and histopathological analyses.MethodsUnder US guidance, 42 rabbit knees were randomly injected with a suspension of 50 mg/ml of either MSU or allopurinol synthetic crystals. The control group received intra-articular vehicle of phosphate-buffered saline (PBS). US evaluation, SF and histopathological analyses were performed at days 1, 3, and 7.ResultsA total of 21 rabbit knees were assigned to the control group, 12 to the MSU-crystals group, and 9 to the allopurinol crystals group. By US, the MSU crystals group displayed the double contour sign and bright stippled aggregates in 67% and 75% of joints, respectively. Neither control knees nor allopurinol crystals group displayed these US signs. Power Doppler (PD) signal was moderate to intense in the MSU-crystals group and greater than both the allopurinol crystal and control groups at day 1 (P <0.001) and 3 (P <0.05), with its practical disappearance by day 7. SF leukocyte count was 40,312 ± 6,369 cells/mm3 in the MSU-crystals group, higher than in controls (P = 0.004) and allopurinol crystal group (P = 0.006). At day 7, SF leukocyte count decreased in both MSU and allopurinol crystal groups reaching the non-inflammatory range. Histologically, at day 3 intense synovial polymorphonuclear cells infiltration and MSU aggregates were identified.ConclusionThe rabbit model of MSU crystal-induced acute arthritis efficiently reproduces the inflammatory, US, SF and histopathological changes of the human acute gouty attack.
Electronic supplementary material
The online version of this article (doi:10.1186/s13075-015-0550-4) contains supplementary material, which is available to authorized users. 相似文献140.
Huntingtin proteolysis releases non‐polyQ fragments that cause toxicity through dynamin 1 dysregulation
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Julie Bruyère Ghislaine Poizat Ismael Al‐Ramahi Raul Pardo Nicolas Bourg Sylvie Souquere Céline Mayet Gérard Pierron Sandrine Lévêque‐Fort Juan Botas Sandrine Humbert Frédéric Saudou 《The EMBO journal》2015,34(17):2255-2271
Cleavage of mutant huntingtin (HTT) is an essential process in Huntington's disease (HD), an inherited neurodegenerative disorder. Cleavage generates N‐ter fragments that contain the polyQ stretch and whose nuclear toxicity is well established. However, the functional defects induced by cleavage of full‐length HTT remain elusive. Moreover, the contribution of non‐polyQ C‐terminal fragments is unknown. Using time‐ and site‐specific control of full‐length HTT proteolysis, we show that specific cleavages are required to disrupt intramolecular interactions within HTT and to cause toxicity in cells and flies. Surprisingly, in addition to the canonical pathogenic N‐ter fragments, the C‐ter fragments generated, that do not contain the polyQ stretch, induced toxicity via dilation of the endoplasmic reticulum (ER) and increased ER stress. C‐ter HTT bound to dynamin 1 and subsequently impaired its activity at ER membranes. Our findings support a role for HTT on dynamin 1 function and ER homoeostasis. Proteolysis‐induced alteration of this function may be relevant to disease. 相似文献