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Lactic acid bacteria have long been used to improve the safety of foods through fermentation. Some fermented products were
also early used for their perceived health benefits, which lead to the development of probiotics as we now know them. Probiotics
mainly belong to the genera Lactobacillus and Bifidobacterium. Most members of these genera are not considered pathogens or even opportunistic pathogens. Nevertheless, rare cases of Lactobacillus and Bifidobacterium infection have been reported, possibly even associated with the consumption of probiotic products. Such cases are extremely
rare and the subjects always had severe underlying conditions most often affecting the immune system. There does not seem
to be any risk for the general population. Safety assessments can be performed and many possible tests exist. It is, however,
not certain these tests will prevent rare case of Lactobacillus infection in certain high-risk patients. The benefits of probiotic use should be weighed against the possible small risk.
Such an evaluation will, in most cases, be favourable and should therefore not discourage consumption of probiotics.
Presented at the Second Probiotic Conference, Košice, 15–19 September 2004, Slovakia. 相似文献
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Elena López Arnau Domenech María-José Ferrándiz Maria Jo?o Frias Carmen Ardanuy Mario Ramirez Ernesto García Josefina Li?ares Adela G. de la Campa 《PloS one》2014,9(4)
Antibiotic resistance in Streptococcus pneumoniae has increased worldwide by the spread of a few clones. Fluoroquinolone resistance occurs mainly by alteration of their intracellular targets, the type II DNA topoisomerases, which is acquired either by point mutation or by recombination. Increase in fluoroquinolone-resistance may depend on the balance between antibiotic consumption and the cost that resistance imposes to bacterial fitness. In addition, pneumococcal prophages could play an important role. Prophage induction by fluoroquinolones was confirmed in 4 clinical isolates by using Southern blot hybridization. Clinical isolates (105 fluoroquinolone-resistant and 160 fluoroquinolone-susceptible) were tested for lysogeny by using a PCR assay and functional prophage carriage was studied by mitomycin C induction. Fluoroquinolone-resistant strains harbored fewer inducible prophages (17/43) than fluoroquinolone-susceptible strains (49/70) (P = 0.0018). In addition, isolates of clones associated with fluoroquinolone resistance [CC156 (3/25); CC63 (2/20), and CC81 (1/19)], had lower frequency of functional prophages than isolates of clones with low incidence of fluoroquinolone resistance [CC30 (4/21), CC230 (5/20), CC62 (9/21), and CC180 (21/30)]. Likewise, persistent strains from patients with chronic respiratory diseases subjected to fluoroquinolone treatment had a low frequency of inducible prophages (1/11). Development of ciprofloxacin resistance was tested with two isogenic strains, one lysogenic and the other non-lysogenic: emergence of resistance was only observed in the non-lysogenic strain. These results are compatible with the lysis of lysogenic isolates receiving fluoroquinolones before the development of resistance and explain the inverse relation between presence of inducible prophages and fluoroquinolone-resistance. 相似文献
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Sara Frias Sandra Ramos Bertha Molina Victoria del Castillo Dora Gilda Mayn 《Mutation Research - Genetic Toxicology and Environmental Mutagenesis》2002,520(1-2):25-37
Down syndrome (DS) resulting from free trisomy 21 (FT21) has been largely associated with advanced maternal age. However, approximately 60% of FT21 cases are born to young couples. Thus, the etiological factors responsible for these FT21 children must differ from those proposed for maternal age-related FT21. These factors have not been defined. In this study, we analyzed the chromosomes of peripheral blood lymphocytes from three groups of couples aged ≤35 years, to identify chromosomal trisomies: Group I included 5 couples with normal offspring; Group II included 22 couples with one FT21 child; and Group III consisted of 3 couples with recurrent FT21. A total of 13,809 metaphases were analyzed with G-banding and 60,205 metaphases were analyzed with FISH using a 13/21 centromeric probe. Aneuploidy was significantly more frequent in Groups II and III. The frequencies of hyperdiploid cells were 0.19, 0.49 and 0.96% in Groups I–III, respectively. FISH analysis showed that trisomy 21 cell percentages were 0.08, 0.21 and 0.76 for Groups I–III, respectively, and were very similar to those obtained with G-banding. Trisomy 21 mosaicism was found in 2/22 couples with one FT21 offspring, and in 2/3 couples with recurrent FT21. Our data suggest that mosaicism is an important cause of FT21 offspring in young couples, and that aneuploidy is more frequent among couples with FT21 offspring. This may be related with age and other undetermined intrinsic and extrinsic factors. 相似文献
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Frias J; Bakhsh A; Jones D; Arthur A; Vidal-Valverde C; Rhodes M; Hedley C 《Journal of experimental botany》1999,50(333):469-476
Two lentil (Lens culinaris) cultivars, Syrian Local
Large (SLL) and PANT-L-406 (PL), have been used to study the genetics of
the raffinose family of oligosaccharides (RFO) and a related compound,
ciceritol, which is a galactosyl cyclitol. The RFO and ciceritol are the
major soluble -galactosides in lentil
seeds. Crosses were made between the two lentil lines and the patterns of
inheritance for the total -galactoside
content and for individual RFO compounds (raffinose, stachyose, verbascose)
and ciceritol were determined in the embryos and seed coats from single
seeds of the reciprocal F1s, the F2s and ten F3 families. The inheritance
patterns for each of the -galactosides were complex and much of
this complexity was attributed to an interaction between the embryo and its
surrounding testa. A clear-cut segregation pattern was observed for
verbascose. This was the result of PL embryos having very low, or no,
verbascose. The F2 embryos had a segregation ratio of 3 high to 1 low level
for this compound, suggesting that within this cross a low verbascose
content was determined by a single recessive gene. There was good evidence
from the F2 and F3 generations of a negative correlation between low levels
of verbascose and high levels of ciceritol, which suggests a metabolic link
between the RFO pathway and the pathway leading to ciceritol. The data are
discussed in terms of defining strategies for genetically manipulating
the-galactoside composition in lentil seeds, such that their
negative effects on nutrition may be overcome without reducing
significantly their positive role in abiotic stress
resistance. 相似文献
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