论执政为民与新时期的党建

坚持执政为民,是实践"三个代表"重要思想的本质要求,是党的宗旨的新概括,我们党在任何时期都必须清醒认识在为谁执政;坚持执政为民才能保持与时俱进,才能保持党的先进性;坚持执政为民,是巩固党的执政基础,正确使用权力是党执政的关键;以高超的执政能力和领导水平为民执政,是我党长期执政的有力保证。     

Antifungal activity of five different essential oils in vapour phase for the control of Colletotrichum gloeosporioides and Lasiodiplodia theobromae in vitro and on mango

Mango fruit has high commercial value; however, major postharvest losses are encountered throughout the supply chain due to postharvest diseases. These results lead to the search for natural fungicide for postharvest diseases control. The antifungal effects of five essential oils (thyme, clove, cinnamon, anise and vitex) were assessed by disc volatilisation method. Thyme oil vapours at 5 μL per Petriplate, and clove and cinnamon oil at 8 μL per Petriplate showed 100% growth inhibition of mango pathogens in vitro. GC/MS analysis of essential oil showed thymol (23.88), o‐cymol (23.88) and terpinolene (23.88) as the major constituents of thyme oil. Clove and cinnamon oils contain 3‐allyl‐2‐methoxyphenol (37.42%) and benzofuran 3‐methyl (17.97%), respectively. Thyme oil as a fumigant at 66.7 μL L^?1 showed a significant (P < 0.05) inhibition on postharvest pathogens of mango fruits stored at 25 °C for 6 days. Results of our study suggest the possibility of using thyme oil as an alternate natural fungicide to manage postharvest diseases in mango.     

Extraction of Siphonochilus aethiopicus Essential Oil by Steam Distillation

Siphonochilus aethiopicus is an indigenous South African plant also known as African ginger. It has often been used for its medicinal properties to treat various ailments such as flu, colds, and so forth. The research aim of this study was to optimize the process parameters of steam distillation for the extraction of oil from African ginger rhizomes. This technology is the oldest and well known for extracting essential oils due to its economic viability and the higher final oil purity. The effects of operating parameters such as extraction duration, moisture content, particle size, and temperatures between 80°C and 100°C were studied for maximum oil recovery. The oil recovery of 0.61% (w/w) was achieved after 270?min of extraction time, using 6.37% (dry) moisture content of particle size 2.4?mm–4?mm at a maximum temperature of 100°C. Fick’s first law was used to mathematically model the experimental data of this study.     

能源监管领域违法所得法律内涵和认定方式浅析

能源行业法律法规设置了“没收违法所得”行政处罚方式,但违法所得这一概念还存在很多模糊认识,具体认定方式也需要进一步明确。在不同行政机关对违法所得的法律概念存在较大分歧时,能源监管领域应遵循违法所得固有含义和立法原意,结合能源行业的基本特点,采取利润说观点定义违法所得概念,并以全部收人扣减合理支出方式进行计算。     

Impact of microfluidization or ultrasound processing on the antimicrobial activity against Escherichia coli of lemongrass oil-loaded nanoemulsions

The effect of the ultrasonication and microfluidization processing conditions on the antimicrobial activity of lemongrass oil–alginate nanoemulsions was studied. Sonication led to less effective nanoemulsions against Escherichia coli, being the loss of antimicrobial potential dependent on the amplitude and treatment time applied. Namely, nanoemulsions sonicated at 100 μm for 180 s almost completely lost their bactericidal action, leading to 0.3 log-reductions of E. coli population after 30 min of contact time. On the contrary, nanoemulsions processed by microfluidization exhibited an enhanced antimicrobial activity, which was proportional to the number of cycles through the microfluidization chamber. In fact, whereas the coarse emulsion reduced the E. coli population up to 0.66, 2.25 and 5.85 log-units after 5, 15 and 30 min of contact time, the microfluidized nanoemulsions (10 cycles, 150 MPa) achieved 1.37, 5.29 and 7.07 log-reductions. Therefore, nanoemulsions with an improved functionally could be obtained by microfluidization, whereas ultrasounds seem to have a deleterious impact on the antimicrobial activity of lemongrass essential oil.     

Molecular dynamics simulations of mutated Mycobacterium tuberculosis l-alanine dehydrogenase to illuminate the role of key residues

l-Alanine dehydrogenase from Mycobacterium tuberculosis (l-MtAlaDH) catalyzes the NADH-dependent interconversion of l-alanine and pyruvate, and it is considered to be a potential target for the treatment of tuberculosis. The experiment has verified that amino acid replacement of the conserved active-site residues which have strong stability and no great changes in biological evolutionary process, such as His96 and Asp270, could lead to inactive mutants [Ågren et al., J. Mol. Biol. 377 (2008) 1161–1173]. However, the role of these conserved residues in catalytic reaction still remains unclear. Based on the crystal structures, a series of mutant structures were constructed to investigate the role of the conserved residues in enzymatic reaction by using molecular dynamics simulations. The results show that whatever the conserved residues were mutated, the protein can still convert its conformation from open state to closed state as long as NADH is present in active site. Asp270 maintains the stability of nicotinamide ring and ribose of NADH through hydrogen bond interactions, and His96 is helpful to convert the protein conformation by interactions with Gln271, whereas, they would lead to the structural rearrangement in active site and lose the catalytic activity when they were mutated. Additionally, we deduce that Met301 plays a major role in catalytic reaction due to fixing the nicotinamide ring of NADH to prevent its rotation, and we propose that Met301 would be mutated to the hydrophobic residue with large steric hindrance in side chain to test the activity of the protein in future experiment.     

Influence of the Oil Phase on the Microencapsulation by Complex Coacervation

The influence of oil type on the process yield, efficiency of encapsulation, particle size and morphological aspects of coacervated microparticles was investigated. Firstly, several factors affecting microencapsulation of oils by complex coacervation were simultaneously examined. The results indicated that the process yield is mainly dependent on the velocity of homogenization, temperature and polymer ratio. Using optimum conditions for producing microparticles [pH 4.0, 14,000 rpm, 50 °C, gelatin:gum arabic (GE:GA) 1:1 and 2.5 % w/v], different core materials were tested: a vegetable oil (almond oil), an oil with higher hydrophilic lipophilic balance (vetiver essential oil) and a highly hydrophobic oil (mineral oil). The oil phase exerted an influence on microparticle formation, disturbing the complexation of polymers and modifying the core distribution within the particles. Some of the polymers were complexed when mineral oil was used, and the highest efficiency of encapsulation (91.8 %) was obtained with vetiver oil, followed by the almond (70.6 %) and mineral (38.0 %) oils. Particles produced with vetiver oil were larger (43.5 μm) than those produced with mineral oil (35.0 μm) and almond oil (19.2 μm), and the increase in the size is due to the encapsulation of many small droplets of emulsion, characterizing these particles as multinucleate ones.     

Preservative effectiveness of essential oils in vapor phase combined with modified atmosphere packaging against spoilage bacteria on fresh cabbage

This study was conducted to investigate the antibacterial effects of various essential oils (EOs) against pathogens using the disc volatilization method. Also, combined effects of EOs in vapor phase and MAP were evaluated for reducing levels of total mesophilic microorganisms on fresh cabbage. The vapor phase activities of EOs (thyme-1, oregano-1, lemongrass-1, and lemongrass-2 oils) observed strong inhibitory effects. The MAP results showed that 100% CO₂ gas packaging reduced significantly levels of total mesophilic microorganisms on cabbage and radish sprouts, and their reduction level was 1.55 and 2.26 log₁₀ CFU/g compared to control after 21 days of storage (p ≤ 0.05). Based on previous results, combined effects of EOs in vapor phase and MAP (100% CO₂) showed that lemongrass-2 oil with 20 discs showed complete inactivation by <1.0 log₁₀ CFU/g after 14 days of storage. These results could provide useful information for developing alternative preservation method to improve the freshness and shelf-life of fresh produce using natural antimicrobials.     

Optimization of supercritical CO2 extraction of dried Helichrysum italicum flowers by response surface methodology: GC-MS profiles of the extracts and essential oil

Supercritical (SC) CO₂ extraction of dried Immortelle flowers was performed at different process parameters. The optimal extraction conditions related to the yield were determined by response surface methodology (yield 4.09% at 20 MPa and 52°C). The extracts were analyzed by GC-MS and tremetone derivatives dominated: bitalin A, 12-acetoxytremetone, gnaphaliol, 1-[2-(2-methyl-2,3-dihydroxypropyl)-2,3-dihydro-1-benzofuran-5-yl]ethanone, isobutyl bitalin A, and 1-[2-(acetylprop-1-en-2-yl)-3-hydroxy-2,3-dihydro-1-benzofuran-5-yl]ethanone. Striking differences were found among the essential oil and SC-CO₂ extracts composition. The major oil compounds were γ-curcumene, α-pinene, β-selinene, α-selinene, and limonene. Mono- and sesquiterpene were found among minor constituents of the extracts. Neryl acetate was present in the extracts and essential oil.     

Daily Enteral DHA Supplementation Alleviates Deficiency in Premature Infants

Docosahexaenoic acid (DHA) is an essential fatty acid (FA) important for health and neurodevelopment. Premature infants are at risk of DHA deficiency and circulating levels directly correlate with health outcomes. Most supplementation strategies have focused on increasing DHA content in mother's milk or infant formula. However, extremely premature infants may not reach full feedings for weeks and commercially available parenteral lipid emulsions do not contain preformed DHA, so blood levels decline rapidly after birth. Our objective was to develop a DHA supplementation strategy to overcome these barriers. This double‐blind, randomized, controlled trial determined feasibility, tolerability and efficacy of daily enteral DHA supplementation (50 mg/day) in addition to standard nutrition for preterm infants (24–34 weeks gestational age) beginning in the first week of life. Blood FA levels were analyzed at baseline, full feedings and near discharge in DHA (n = 31) or placebo supplemented (n = 29) preterm infants. Term peers (n = 30) were analyzed for comparison. Preterm infants had lower baseline DHA levels (p < 0.0001). Those receiving DHA had a progressive increase in circulating DHA over time (from 3.33 to 4.09 wt% or 2.88 to 3.55 mol%, p < 0.0001) while placebo‐supplemented infants (receiving standard neonatal nutrition) had no increase over time (from 3.35 to 3.32 wt% or 2.91 to 2.87 mol%). Although levels increased with additional DHA supplementation, preterm infants still had lower blood DHA levels than term peers (4.97 wt% or 4.31 mol%) at discharge (p = 0.0002). No differences in adverse events were observed between the groups. Overall, daily enteral DHA supplementation is feasible and alleviates deficiency in premature infants.