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41.
42.
Lactoferrin concentrations in goat milk throughout lactation 总被引:1,自引:0,他引:1
Lactoferrin is an iron-binding glycoprotein and is considered a major part of the non-specific disease resistance complex in the mammary gland. For cows, the influence of physiological factors on the lactoferrin concentration in milk has been reported. In addition, lactoferrin concentrations have been demonstrated to be proportional to somatic cell counts (SCC) in cows milk. In this study, we aimed to analyse the effects of lactational stage, lactation number and SCC in 19 goats throughout an entire lactational period. Lactoferrin concentrations in weekly composite milk samples were analysed with a competitive ELISA developed for caprine lactoferrin. Maximal lactoferrin concentrations were observed in the colostral samples (387 ± 69 μg/ml). In the following week, less than 20% of these concentrations were observed (62 ± 25 μg/ml) and thereafter until week 32 p.p., the weekly mean concentrations ranged between 10 and 28 μg/ml. Toward the end of lactation, approximately during the 33rd week, the concentrations began to increase and were reaching about 3.2-fold higher values in week 44 (107 ± 19 μg/ml). SCC were only available in monthly intervals and could thus not be directly related to the weekly lactoferrin recordings. When classifying the individual goats according to the median of their SCC values obtained during midlactation, the goats with SCC medians >430,000 had higher lactoferrin milk concentrations during this time than the ones with SCC below this threshold (P < 0.05). In addition, sampling week and parity significantly affected the lactoferrin concentration (P < 0.05 and P < 0.01, respectively). Comparing SCC and lactoferrin, both parameters are significantly affected by various physiological factors. Further studies are needed to clarify if the relationship between Lf and bacterial counts is closer compared to the relationship between SCC and bacterial counts. 相似文献
43.
Kay S Donin N Michowitz M Katzenelson D Hiss J Schibi G Pinchassov A Leibovici J 《Biochimica et biophysica acta》2000,1497(1):37-50
Disturbance of apoptosis is an established factor in tumorigenesis. The role of apoptosis in tumor progression is not yet clear. In the present study we compared the tendency to spontaneous apoptosis (and the proliferative capacity) of tumor cells derived from primary (PT) and metastatic tumor (MT) cells of several AKR lymphoma variants. Apoptosis-related gene expression was also compared. Our results indicate that release from apoptosis has a role in the tumor progression of this T cell lymphoma. At the cellular level, a markedly lower apoptotic tendency was observed in MT than in PT cells. The existence of macrophages only in PT also supports the presence of apoptotic cells in local but not in MTs. By contrast, proliferative capacity does not determine tumor aggressiveness in this system. At the molecular level, we found a higher staining intensity for bcl-2 in MT than in PT cells, suggesting that bcl-2 might be responsible for the reduced apoptosis in MT compared to PT cells. Evidence for p53 overexpression was found in the MT cells of one of the variants but in none of the PT. Comparison of Fas receptor, unexpectedly showed an increased expression in MT versus PT cells, possibly indicating resistance to Fas-induced apoptosis in the MT cells. 相似文献
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Male Aedes aegypti produce a substance made or stored in their accessory glands, which when passed on to females via mating, will prevent subsequent insemination. In addition to becoming refractory with regard to further insemination, mated females also oviposit far more eggs than virgins. The male accessory gland substance, called matrone, has been highly purified and when injected into virgin females, prevents any initial insemination, and will also stimulate oviposition. 相似文献
46.
Chaehee Lee In-Su Choi Domingos Cardoso Haroldo C. de Lima Luciano P. de Queiroz Martin F. Wojciechowski Robert K. Jansen Tracey A. Ruhlman 《The Plant journal : for cell and molecular biology》2021,107(3):861-875
The plastid genome (plastome), while surprisingly constant in gene order and content across most photosynthetic angiosperms, exhibits variability in several unrelated lineages. During the diversification history of the legume family Fabaceae, plastomes have undergone many rearrangements, including inversions, expansion, contraction and loss of the typical inverted repeat (IR), gene loss and repeat accumulation in both shared and independent events. While legume plastomes have been the subject of study for some time, most work has focused on agricultural species in the IR-lacking clade (IRLC) and the plant model Medicago truncatula. The subfamily Papilionoideae, which contains virtually all of the agricultural legume species, also comprises most of the plastome variation detected thus far in the family. In this study three non-papilioniods were included among 34 newly sequenced legume plastomes, along with 33 publicly available sequences, to assess plastome structural evolution in the subfamily. In an effort to examine plastome variation across the subfamily, approximately 20% of the sampling represents the IRLC with the remainder selected to represent the early-branching papilionoid clades. A number of IR-related and repeat-mediated changes were identified and examined in a phylogenetic context. Recombination between direct repeats associated with ycf2 resulted in intraindividual plastome heteroplasmy. Although loss of the IR has not been reported in legumes outside of the IRLC, one genistoid taxon was found to completely lack the typical plastome IR. The role of the IR and non-IR repeats in the progression of plastome change is discussed. 相似文献
47.
Luiz G. A. Alves Débora B. Scariot Renato R. Guimar?es Celso V. Nakamura Renio S. Mendes Haroldo V. Ribeiro 《PloS one》2016,11(3)
We report on a diffusive analysis of the motion of flagellate protozoa species. These parasites are the etiological agents of neglected tropical diseases: leishmaniasis caused by Leishmania amazonensis and Leishmania braziliensis, African sleeping sickness caused by Trypanosoma brucei, and Chagas disease caused by Trypanosoma cruzi. By tracking the positions of these parasites and evaluating the variance related to the radial positions, we find that their motions are characterized by a short-time transient superdiffusive behavior. Also, the probability distributions of the radial positions are self-similar and can be approximated by a stretched Gaussian distribution. We further investigate the probability distributions of the radial velocities of individual trajectories. Among several candidates, we find that the generalized gamma distribution shows a good agreement with these distributions. The velocity time series have long-range correlations, displaying a strong persistent behavior (Hurst exponents close to one). The prevalence of “universal” patterns across all analyzed species indicates that similar mechanisms may be ruling the motion of these parasites, despite their differences in morphological traits. In addition, further analysis of these patterns could become a useful tool for investigating the activity of new candidate drugs against these and others neglected tropical diseases. 相似文献
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Braulio J. Soto-Cerda Enrique H. Peñaloza Adolfo B. Montenegro Annally R. Rupayan Milton H. Gallardo Haroldo Salvo-Garrido 《Molecular breeding : new strategies in plant improvement》2013,31(4):855-866
To feed the predicted extra two billion people by 2050, crop production must increase on existing cultivated land at a rate that challenges our current capability. Acid soils and aluminium (Al3+) toxicity restrict productivity worldwide but also offer the greatest opportunity for increases in global food production. Our understanding of the physiology, genetic control and the identification of genomic regions underlying Al resistance in important staple crops has increased greatly over the past 20 years, enabling the application of molecular breeding. In this study, we report the application of an efficient marker-assisted backcrossing (MAB) strategy for the introgression of the HvAACT1 gene which confers Al resistance in barley (Hordeum vulgare L.). We conducted foreground and background selection using microsatellite (SSR) markers linked to HvAACT1 and SSR-based linkage maps, along with embryo rescue and a cost-effective DNA preparation method shortening the breeding cycle to ~18 months. The MAB strategy enabled the development of homozygous (BC3F2) Al-resistant lines with the smallest introgressed region and 98.7 % of the recurrent parent genome. The Al-resistant line yielded significantly more seeds (121 %) than its isogenic line in soil-based assays containing 12 % of Al saturation. This MAB strategy could be extended to other staple crops with similar molecular toolboxes, expanding their cultivation onto acid soils, and contributing to greater yield stability and food security, particularly in developing countries. 相似文献
50.
Haroldo A. Toque Kenia P. Nunes Lin Yao Zhimin Xu Dmitry Kondrikov Yunchao Su R. Clinton Webb Ruth B. Caldwell R. William Caldwell 《PloS one》2013,8(8)