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21.
Glucosidation of the appropriate 1,3 or 1,4-bis(4-amino or arylideneamino-2,4-dihydro-3-thioxo-3H-1,2,4-triazol-5-ylthio)propanes or butanes with 2,3,4,6-tetra-O-acetyl-alpha-D-glucopyranosyl bromide followed by chromatographic separation gave the corresponding N-, S-, and N,S-bis(glucosides). Chemical transformation leading to new functionalities has been achieved. Antimicrobial screening of 10 selected compounds resulted in their activity against Aspergillus fumigatus, Penicillium italicum, Syncephalastrum racemosum, Candida albicans, Staphylococcus aureus, Pseudomonas aeruginosa, Bacillus subtilis, and Escherichia coli.  相似文献   
22.
In this paper, we present a new DNA-based evaluation algorithm for a Boolean circuit that employs standard bio-molecular techniques. The algorithm operates on an unbounded fan-in Boolean circuit consisting of AND and OR gates. The whole simulation of our algorithm is proposed in a single test tube in O(1) time complexity and is much easier to implement in the laboratory than previously described models. Furthermore, the algorithm allows for evaluating any number of Boolean circuits in parallel in a single test tube.  相似文献   
23.
Vitamin D deficiency is associated with several diseases including multiple sclerosis (MS). Several factors influence vitamin D levels and its optimal multi-function maintenance. Our objective was to assess quantifiable variables influencing vitamin D level and metabolism in MS patients from Kuwait. In a case-control study involving 50 MS patients, and 50 healthy control individuals for which plasma vitamin D levels, supplement use, vitamin D receptor (VDR) variants, and skin pigmentation indices were ascertained; we found overall vitamin D levels to be deficient in both groups, and supplement use to be common practice. VDR variants TaqI and BsmI associated with MS risk, and ApaI associated with low disease progression. VDR variant FokI associated with higher vitamin D levels in both groups. We conclude that several quantifiable variables related to vitamin D associate with MS suggesting a possible clinical immuno-modulatory application of vitamin D for MS patients in Kuwait.  相似文献   
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25.
A series of 1,2,4-triazolylchromanone oxime ethers were synthesized and tested for in vitro antifungal activity. Many of these derivatives exhibit high activity against Candida albicans, Saccharomyces cerevisiae, Aspergillus niger and Microsporum gypseum.  相似文献   
26.
The most common cause of blindness in developing countries is vitamin A deficiency. The World Health Organization estimates 13.8 million children to have some degree of visual loss related to vitamin A deficiency. The causes of night blindness in children are multifactorial, and particular consideration has been given to childhood nutritional deficiency, which is the most common problem found in underdeveloped countries. Such deficiency can result in physiological and pathological processes that in turn influence biological samples composition. Vitamin and mineral deficiency prevents more than two billion people from achieving their full intellectual and physical potential. This study was designed to compare the levels of Zn, Mg, Ca, K, Na, As, Cd, and Pb in scalp hair, blood, and urine of night blindness children age ranged 3–7 and 8–12 years of both genders, comparing them to sex- and age-matched controls. A microwave-assisted wet acid digestion procedure was developed as a sample pretreatment, for the determination of As, Ca, Cd, K, Pb, Mg, Na, and Zn in biological samples of night blindness children. The proposed method was validated by using conventional wet digestion and certified reference samples of hair, blood, and urine. The concentrations of trace and toxic elements were measured by atomic absorption spectrophotometer prior to microwave-assisted acid digestion. The results of this study showed that the mean values of As, Cd, Na, and Pb were significantly higher in scalp hair, blood, and urine samples of male and female night blindness children than in referents (p?<?0.001), whereas the concentrations of Zn, Ca, K, and Mg were lower in the scalp hair and blood but higher in the urine samples of night blindness children. These data present guidance to clinicians and other professional investigating deficiency of essential mineral elements in biological samples (scalp hair and blood) of night blindness children.  相似文献   
27.
Anaerobic ferrous oxidation by heterotrophic denitrifying enriched culture   总被引:1,自引:0,他引:1  
Heterotrophic denitrifying enriched culture (DEC) from a lab-scale high-rate denitrifying reactor was discovered to perform nitrate-dependent anaerobic ferrous oxidation (NAFO). The DEC was systematically investigated to reveal their denitrification activity, their NAFO activity, and the predominant microbial population. The DEC was capable of heterotrophic denitrification with methanol as the electron donor, and autotrophic denitrification with ferrous salt as the electron donor named NAFO. The conversion ratios of ferrous-Fe and nitrate-N were 87.41 and 98.74 %, and the consumption Fe/N ratio was 2.3:1 (mol/mol). The maximum reaction velocity and half saturation constant of Fe were 412.54 mg/(l h) and 8,276.44 mg/l, and the counterparts of N were 20.87 mg/(l h) and 322.58 mg/l, respectively. The predominant bacteria were Hyphomicrobium, Thauera, and Flavobacterium, and the predominant archaea were Methanomethylovorans, Methanohalophilus, and Methanolobus. The discovery of NAFO by heterotrophic DEC is significant for the development of wastewater treatment and the biogeochemical iron cycle and nitrogen cycle.  相似文献   
28.
The effect of nitrogen forms on photosynthesis and anti-oxidative systems of barley plants under chromium stress was studied in a hydroponic experiment. The treatments comprised three chromium concentrations (0, 75, and 100 μM) and three N forms (NH4)2SO4, urea, and Ca(NO3)2. In comparison with the urea or (NH4)2SO4 fed plants, the Ca(NO3)2 fed plants had higher net photosynthetic rate, intercellular CO2 concentration, stomatal conductance, transpiration rate, photosynthetically active radiation utilization efficiency, variable to maximum chlorophyll fluorescence ratio, and the content of chlorophylls and carotenoids. Cr toxicity caused oxidative stress in all plants but the Ca(NO3)2 fed plants had the least oxidative stress. Moreover, the Ca(NO3)2 fed plants had higher activities of anti-oxidative enzymes and content of non-enzymatic antioxidants than the urea or (NH4)2SO4 fed plants. In addition, the Ca(NO3)2 fed plants had higher N and lower Cr content in all plant tissues than the urea or (NH4)2SO4 fed plants. The current results indicate that the reasonable choice of N fertilizer is important for barley production on the Cr-contaminated soils.  相似文献   
29.

Objectives

Recent evidence suggests that suicidal ideation is increased among university students, it is essential to increase our knowledge concerning the etiology of suicidal ideation among university students. This study was conducted to examine the relationships between problem-solving skills appraisal, hardiness, and suicidal ideation among university students. In addition, this study was conducted to examine problem-solving skills appraisal (including the three components of problem-solving confidence, approach-avoidance style, and personal control of emotion) as a potential mediator between hardiness and suicidal ideation.

Methods

The participants consisted of 500 undergraduate students from Malaysian public universities.

Results

Structural Equation Modelling (SEM) estimated that undergraduate students with lower hardiness, poor problem-solving confidence, external personal control of emotion, and avoiding style was associated with higher suicidal ideation. Problem-solving skills appraisal (including the three components of problem-solving confidence, approach-avoidance style, and personal control of emotion) partially mediated the relationship between hardiness and suicidal ideation.

Conclusion

These findings underline the importance of studying mediating processes that explain how hardiness affects suicidal ideation.  相似文献   
30.
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