MECHANISM OF PROMOTING EFFECTS OF RIBOFLAVIN DEFICIENCY ON CARCINOGENESIS OF NITROSAMINES (EFFECTS ON RAT LIVER GLUTATHIONE CONTENT)

The effects of riboflavin deficiency and simultaneously nitrosodimethylamine (NDMA) given by gastric intubation on the hepatic glutathione (GSH) content were examined in rats. On different days of the experiment, hepatic GSH content of the riboflavin deficient rats decreased to 55-61% of the control rats. When NDMA was given 6 mg kg by gastric intubation to riboflavin deficient rats, hepatic GSH content decreased markedly to 39-43% of the control rats. After supplying riboflavin, hepatie GSH content of the deficient rats recovered to the level of the control rats. These results suggest that alterations of rat hepatic GSH content during riboflavin deficiency may imply as one of the promoting effects of riboflavin deficiency on the carcinogenesis of nitrosamines.

Study on the Promoting Mechanism of Teachers'Ethics Internalization in Universities

On the basis of clarifying the teachers'Ethics internalization theory,this paper analyzes the typical dilemma in teachers'Ethics internalization.To resolve these problems,this paper construct an overall framework,including security mechanism,normative mechanism,education mechanism,evaluation mechanism and supervision mechanism,which the external conditions are used to constantly strengthen the moral needs of the subject,then enhance the consciousness of moral internalization,improve the effectiveness of teachers'moral construction.

Research progress on the application of microneedle transdermal drug delivery system in dermatology

Transdermal drug delivery systems(TDDs)have the advantages on good local targeting,controlled and sustainable drug delivery.Hoewever,the stratum corneum,as the main skin barrier,severely limits the transdermal penetration of drugs and reduces bioavailability,which also limits their application.Microneedles(MNS)penetrate the stratum corneum and create several reversible microchannels in a minimally invasive manner to significantly improve the penetration of therapeutic agents,and are considered a milestone for effective transdermal drug delivery.As an emerging drug delivery modality,microneedle transdermal drug delivery systems have the advantages of being minimally invasive,safe,efficient,economical and convenient.In addition to the extensive research on microneedles for improving transdermal drug delivery,there is a growing interest in using them to manage and treat dermatological conditions.Being the largest organ in the human body,the skin acts as a barrier between the body and the external environment,while having an immense influence on appearance and self-confidence.Indeed,there is now a considerable body of evidence on how dermatological conditions can lead to psychological problems and a reduced quality of life.The utilisation of microneedle transdermal drug delivery systems for the management and treatment of dermatological conditions is of great therapeutic and commercial value.The principleof microneedle transdermal drug delivery systems and the progress of its clinical application in dermatology are reviewed here.

Co-or Ni-modified Sn-MnO_(x) low-dimensional multi-oxides for high-efficient NH_(3)-SCR De-NO_(x):Performance optimization and reaction mechanism

NH_(3)-SCR performances were explored to the relationship between structure morphology and physio-chemical properties over low-dimensional ternary Mn-based catalysts prepared by one-step synthesis method.Due to its strong oxidation performance,Sn-MnO_(x) was prone to side reactions between NO,NH_(3)and O_(2),resulting in the generation of more NO_(2)and N_(2)O,here most of N_(2)O was driven from the non-selective oxidation of NH_(3),while a small part generated from the side reaction between NH_(3)and NO_(2).Co or Ni doping into Sn-MnO_(x) as solid solution components obviously stronged the electronic interaction for actively mobilization and weakened the oxidation performance for signally reducing the selective tendency of side reactions to N_(2)O.The optimal modification resulted in improving the surface area and enhancing the strong interaction between polyvalent cations in Co/Ni-Mn-SnO_(2)to provide more surface adsorbed oxygen,active sites of Mn^(3+) and Mn^(4+),high-content Sn^(4+) and plentiful Lewis-acidity for more active intermediates,which significantly broadened the activity window of Sn-MnOx,improved the N^(2) selectivity by inhibiting N_(2)O formation,and also contributed to an acceptable resistances to water and sulfur.At low reaction temperatures,the SCR reactions over three catalysts mainly obeyed the typical Elye-rideal(E-R)routs via the reactions of adsorbed L-NH_(x)(x=3,2,1)and B-NH_(4)^(+) with the gaseous NO to generate N_(2) but also N_(2)O by-products.Except for the above basic E-R reactions,as increasing the reaction temperature,the main adsorbed NO_(x)-species were bidentate nitrates that were also active in the Langmuir-Hinshelwood reactions with adsorbed L-NH_(x) species over Co/Ni modified Mn-SnO_(2) catalyst.

Superior performance in visible-light-driven hydrogen evolution reaction of three-dimensionally ordered macroporous SrTiO_(3) decorated with Zn_(x)Cd_(1−x)S

It is of broad interest to develop emerging photocatalysts with excellent light-harvesting capacity and high charge carrier separation efficiency for visible light photocatalytic hydrogen evolution reaction.However,achieving satisfying hydrogen evolution efficiency under noble metal-free conditions remains challenging.In this study,we demonstrate the fabrication of three-dimensionally ordered macroporous SrTiO_(3)decorated with Zn_(x)Cd_(1−x)S nanoparticles for hydrogen production under visible light irradiation(λ>420 nm).Synergetic enhancement of photocatalytic activity is achieved by the slow photon effect and improved separation efficiency of photogenerated charge carriers.The obtained composites could afford very high hydrogen production efficiencies up to 19.67 mmol·g^(−1)·h^(−1),with an apparent quantum efficiency of 35.9%at 420 nm,which is 4.2 and 23.9 times higher than those of pure Zn_(0.5)Cd_(0.5)S(4.67 mmol·g^(−1)·h^(−1))and CdS(0.82 mmol·g^(−1)·h^(−1)),respectively.In particular,under Pt-free conditions,an attractive hydrogen production rate(3.23 mmol·g^(−1)·h^(−1))was achieved,providing a low-cost and high-efficiency strategy to produce hydrogen from water splitting.Moreover,the composites showed excellent stability,and no obvious loss in activity was observed after five cycling tests.