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981.
Single nucleotide polymorphism detection using gold nanoprobes and bio‐microfluidic platform with embedded microlenses
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982.
983.
Giuseppe PO Von Atzingen M Nascimento AL Zanchin NI Guimarães BG 《Journal of structural biology》2011,173(2):312-322
Leptospirosis is a world spread zoonosis caused by members of the genus Leptospira. Although leptospires were identified as the causal agent of leptospirosis almost 100 years ago, little is known about their biology, which hinders the development of new treatment and prevention strategies. One of the several aspects of the leptospiral biology not yet elucidated is the process by which outer membrane proteins (OMPs) traverse the periplasm and are inserted into the outer membrane. The crystal structure determination of the conserved hypothetical protein LIC12922 from Leptospira interrogans revealed a two domain protein homologous to the Escherichia coli periplasmic chaperone SurA. The LIC12922 NC-domain is structurally related to the chaperone modules of E. coli SurA and trigger factor, whereas the parvulin domain is devoid of peptidyl prolyl cis-trans isomerase activity. Phylogenetic analyses suggest a relationship between LIC12922 and the chaperones PrsA, PpiD and SurA. Based on our structural and evolutionary analyses, we postulate that LIC12922 is a periplasmic chaperone involved in OMPs biogenesis in Leptospira spp. Since LIC12922 homologs were identified in all spirochetal genomes sequenced to date, this assumption may have implications for the OMPs biogenesis studies not only in leptospires but in the entire Phylum Spirochaetes. 相似文献
984.
Orioli IM Lima do Nascimento R López-Camelo JS Castilla EE 《Birth defects research. Part A, Clinical and molecular teratology》2011,91(9):831-835
BACKGROUND: To assess spina bifida birth prevalence changes after folic acid fortification of wheat and maize flours began in Brazil in June 2004. METHODS: Cross‐sectional study of Brazilian live births in 2004 and 2006. Spina bifida birth prevalence from the Live Births Information System (SINASC: Sistema de Informações sobre Nascidos Vivos) in a prefortified period was compared to a period fortified with folic acid in each state. Observed prevalence rates in 2004 were used to calculate the expected prevalence rates in 2006 under the null hypothesis that both were similar. The observed/expected (O/E) ratios were tested by two‐tailed Z‐test. To minimize ascertainment differences among states, the O/E ratio of each one of the 27 Brazilian states was adjusted for the number of births with the Mantel‐Haenszel statistic. RESULTS The reduction in spina bifida birth prevalence in 2006 was 39% (O/E = 0.61; 95% confidence interval [CI], 0.55‐0.67), and 40% (O/E = 0.60; 95% CI, 0.53–0.68), after adjusting for state birth number. This reduction was significant (p < 0.0001), and heterogeneous among states (χ2 = 72.96; p < 0.0001). CONCLUSIONS: Using SINASC data, there was a significant reduction in spina bifida birth prevalence in Brazil, probably related to the folic acid food fortification program. Birth Defects Research (Part A) 2011. © 2011 Wiley‐Liss, Inc. 相似文献
985.
Sporotrichosis is a subcutaneous mycosis caused by Sporothrix schenckii. Zoonotic transmission to man can occur after scratches or bites of animals, mainly cats. In this study, the gamma radiation
effects on yeast of S. schenckii were analyzed with a view of developing a radioattenuated vaccine for veterinary use. The cultures were irradiated at doses
ranging from 1.0 to 9.0 kGy. The reproductive capacity was measured by the ability of cells to form colonies. No colonies
could be recovered above 8.0 kGy, using inocula up to 107 cells. Nevertheless, yeast cells irradiated with 7.0 kGy already were unable to produce infection in immunosuppressed mice.
Evaluation by the FungaLight™ Kit (Invitrogen) indicated that yeast cells remained viable up to 9.0 kGy. At 7.0 kGy, protein
synthesis, estimated by the incorporation of [L-35S] methionine, continues at levels slightly lower than the controls, but a significant decrease was observed at 9.0 kGy. The
DNA of 7.0 kGy irradiated cells, analyzed by electrophoresis in agarose gel, was degraded. Cytoplasmic vacuolation was the
main change verified in these cells by transmission electron microscopy. The dose of 7.0 kGy was considered satisfactory for
yeast attenuation since irradiated cells were unable to produce infection but retained viability, metabolic activity, and
morphology. 相似文献
986.
Gonçaves JM Ferreira J Prado MA Cordeiro MN Richardson M Pinheiro AC Silva MA Junior CJ Souza AH Gomez MV 《Cellular and molecular neurobiology》2011,31(2):277-283
In spinal cord synaptosomes, the spider toxin PhTx3-4 inhibited capsaicin-stimulated release of glutamate in both calcium-dependent
and -independent manners. In contrast, the conus toxins, ω-conotoxin MVIIA and ω-conotoxin MVIIC, only inhibited calcium-dependent
glutamate release. PhTx3-4, but not ω-conotoxin MVIIA or ω-conotoxin MVIIC, is able to inhibit the uptake of glutamate by
synaptosomes, and this inhibition in turn leads to a decrease in the Ca2+-independent release of glutamate. No other polypeptide toxin so far described has this effect. PhTx3-4 and ω-conotoxins MVIIC
and MVIIA are blockers of voltage-dependent calcium channels, and they significantly inhibited the capsaicin-induced rise
of intracellular calcium [Ca2+]i in spinal cord synaptosomes, which likely reflects calcium entry through voltage-gated calcium channels. The inhibition of
the calcium-independent glutamate release by PhTx3-4 suggests a potential use of the toxin to block abnormal glutamate release
in pathological conditions such as pain. 相似文献
987.
Paulo C. do Nascimento Marieli S. da Marques Denise Bohrer Leandro M. de Carvalho Claudia W. Carvalho 《Biological trace element research》2011,141(1-3):76-85
The distribution of Cd (II) and Pb (II) among amino acids in parenteral nutrition formulations was investigated by coupling ion-chromatography (HPLC/IC) and electrothermal atomic absorption spectrometry. The methodology was based on ion-exchange separation and fluorimetric amino acid detection after post-column derivatization. Cd (II) and Pb (II) were assayed in 500-µL fractions of the column effluent. The distribution of Cd (II) and Pb (II) in alanine (Ala), aspartic acid (Asp), glutamic acid (Glu), glycine (Gly), histidine (His), methionine (Met), phenylalanine (Phe), serine (Ser), and threonine (Thr) were analyzed by monitoring changes in the concentration of free amino acids by HPLC/IC. The results indicated that Cd (II) and Pb (II) were distributed according to the following trend: Gly–Cd?>?Gly–Pb?>?Ala–Cd?>?Ala–Pb?>?His–Cd?~?His–Pb?>?Thr–Cd?>?Thr–Pb?>?Phe–Cd?~?Phe–Pb?~?Asp–Cd?~?Asp–Pb?~?Met–Cd?~?Met–Pb?~?Glu–Cd?~?Glu–Pb?>?Ser–Cd?~?Ser–Pb. The effects of amino acid concentration and stability constants of amino acid–metal complexes are discussed. 相似文献
988.
Araujo-Chaves JC Yokomizo CH Kawai C Mugnol KC Prieto T Nascimento OR Nantes IL 《Journal of bioenergetics and biomembranes》2011,43(6):663-671
Aerobic organisms are afforded with an antioxidant enzymatic apparatus that more recently has been recognized to include cytochrome
c, as it is able to prevent hydrogen peroxide generation by returning electrons from the superoxide ion back to the respiratory
chain. The present study investigated the glutathione peroxidase (GPx), superoxide dismutase (SOD) and cytochrome c-like antioxidant activities of para Mn(III)TMPyP in isolated rat liver mitochondria (RLM) and mitoplasts. In RLM, MnIIITMPyP decreased the lipid-peroxide content associated with glutathione (GSH) depletion consistent with the use of GSH as a
reducing agent for high valence states of MnIIITMPyP. SOD and cytochrome c antioxidant activities were also investigated. MnIITMPyP was able to reduce ferric cytochrome c, indicating the potential to remove a superoxide ion by returning electrons back to the respiratory chain. In antimicyn A-poisoned
mitoplasts, MnIIITMPyP efficiently decreased the EPR signal of DMPO-OH adduct concomitant with GSH depletion. The present results are consistent
with SOD and GPx activities for MnIIITMPyP and do not exclude cytochrome c-like activity. However, considering that para MnIIITMPyP more efficiently reduces, rather than oxidizes, superoxide ion; electron transfer from the MnIITMPyP to the respiratory chain might not significantly contribute to the superoxide ion removal, since most of MnIITMPyP is expected to be produced at the expense of NADPH/GSH oxidation. The present results suggest GPx-like activity to be
the principal antioxidant mechanism of MnIIITMPyP, whose efficiency is dependent on the NADPH/GSH content in cells. 相似文献
989.
dos Santos Rocha PB de Castro Amorim A de Sousa AF do Monte SJ da Mata Sousa LC do Nascimento Nogueira N Neto JM do Nascimento Marreiro D 《Biological trace element research》2011,143(2):603-611
Research has investigated the participation of zinc transport proteins and metallothionein in the metabolism of this mineral.
However, studies about the genetic expression of these proteins in obese patients are scarce. The study determined the expression
of zinc transporter protein codifying genes (ZnT-1, Zip-1 and Zip-3) and of metallothionein in 55 obese women, aged between
20 and 56 years. The assessment of body composition was carried out using anthropometric measurements and bioelectrical impedance.
Zinc intake was obtained by recording diet over a 3-day period, and the nutritional analysis was carried out using NutWin
software version 1.5. The plasmatic and erythrocytary zinc were analyzed by atomic absorption spectrophotometry (λ = 213. 9 nm). The determination of mRNA expression of the zinc transporter proteins and metallothionein was carried out using
blood, using the RT-PCR method. The mean values of body mass index were 37.9 ± 5.5 kg/m2. The average intake of zinc was 9.4 ± 2.3 mg/day. The analysis of the zinc plasma concentrations showed values of 58.4 ± 10.9 μg/dL.
The mean values of zinc in the erythroytes were 38.7 ± 9.1 μg/g Hb. The metallothionein gene had a higher expression in the
blood, when compared to zinc transporters ZnT-1, Zip-1, and Zip-3 (p = 0.01). The study shows that there are alterations in the biochemical parameters of zinc in obese patients assessed, as
well as higher expression of the codifying gene metallothionein, when compared to the investigated zinc transporters. 相似文献
990.
Priscila Brigide Terezinha R. Ataide Antônio S. Baptista Solange G. Canniatti-Brazaca Adibe L. Abdalla Virgílio F. Nascimento Filho Sonia M. S. Piedade Antônio E. G. Sant’Ana 《Biological trace element research》2011,140(1):53-65
The consumption of the regional basic diet (RBD) determines a state of malnutrition found in the low-income population of
Northeastern Brazil. A dietary supplement known as multimixture has been used as an alternative source of iron in food for
the prevention and/or treatment of anemia and for the recovery from malnutrition. The purpose of the present work was to evaluate
the bioavailability of iron in the RBD supplemented with multimixture in iron-depleted and non-depleted Wistar rats. To produce
iron depletion in the animals, pretest depletion diets without iron and the pretest control diet based on the AIN-93 diet
were used for 8 weeks. This phase was followed by the test diets: control, AIN-93 extrinsically labeled with 59FeCl3; RBD, containing carioca beans intrinsically labeled with 59Fe; and RBDMM, RBD plus multimixture, supplied in a single meal. Hemoglobin concentration, weight gain, and dietary intake were determined
in the pretest phase. Iron bioavailability was determined by the determination of total-body radiation in the animals for
7 days, using a solid scintillation detector. The hemoglobin concentration, weight gain, and dietary intake were greater in
the non-depleted animals than in the iron-depleted ones. The iron bioavailability of the diets did not differ significantly.
It was concluded that the multimixture did not affect the bioavailability of Fe contained in the beans of the RBD. 相似文献