Cost-effective and eco-friendly synthesis of novel and stable N-doped ZnO/g-C3N4 core-shell nanoplates with excellent visible-light responsive photocatalysis

N-doped ZnO/g-C3N4 hybrid core–shell nanoplates have been successfully prepared via a facile, cost-effective and eco-friendly ultrasonic dispersion method for the first time. HRTEM studies confirm the formation of the N-doped ZnO/g-C3N4 hybrid core–shell nanoplates with an average diameter of 50 nm and the g-C3N4 shell thickness can be tuned by varying the content of loaded g-C3N4. The direct contact of the N-doped ZnO surface and g-C3N4 shell without any adhesive interlayer introduced a new carbon energy level in the N-doped ZnO band gap and thereby effectively lowered the band gap energy. Consequently, the as-prepared hybrid core–shell nanoplates showed a greatly enhanced visible-light photocatalysis for the degradation of Rhodamine B compare to that of pure N-doped ZnO surface and g-C3N4. Based on the experimental results, a proposed mechanism for the N-doped ZnO/g-C3N4 photocatalyst was discussed. Interestingly, the hybrid core–shell nanoplates possess high photostability. The improved photocatalytic performance is due to a synergistic effect at the interface of the N-doped ZnO and g-C3N4 including large surface-exposure area, energy band structure and enhanced charge-separation properties. Significantly, the enhanced performance also demonstrates the importance of evaluating new core–shell composite photocatalysts with g-C3N4 as shell material.

Responsive fixture design using dynamic product inspection and monitoring technologies for the precision machining of large-scale aerospace parts

When machining a large-scale aerospace part, the part is normally located and clamped firmly until a set of features are machined. When the part is released, its size and shape may deform beyond the tolerance limits due to stress release. This paper presents the design of a new fixing method and flexible fixtures that would automatically respond to workpiece deformation during machining. Deformation is inspected and monitored on-line, and part location and orientation can be adjusted timely to ensure follow-up operations are carried out under low stress and with respect to the related datum defined in the design models.

Grewia gum 2:mucoadhesive properties of compacts and gels

Purpose: To compare the mucoadhesive performance of grewia polysaccharide gum with those of guar gum, carboxymethylcellulose, hydroxypropyl methylcellulose and carbopol 971P. Methods: Grewia polysaccharide gum compacts or gels as well as those of guar gum, carboxymethylcellulose, hydroxypropyl methylcellulose or carbopol 971P were prepared. Texturometric and tensile analysis of the polymer gels and compacts were carried out using a software-controlled penetrometre, TA.XTPlus texture analyzer. The polymer gels were evaluated for hardness, stickiness, work of cohesion and work of adhesion. Furthermore, the detachment force of the polymer compacts from a mucin substrate was evaluated. Results: The work of adhesion of guar gels was significantly greater than that of grewia gels (p < 0.001) but the latter showed a significantly greater work of adhesion than carboxymethylcellulose gels (p < 0.05) and hydroxypropyl methylcellulose gels (p < 0.001). However, the work of cohesion for grewia/mucin gel mixture was significantly greater (p < 0.001) than those of carboxymethylcellulose/mucin, hydroxypropyl methylcellulose/mucin and carbopol 971P/mucin gel blends. The difference between the mucoadhesive performance of grewia compacts and those of hydroxypropyl methylcellulose and carbopol 971P compacts was insignificant (p > 0.05). Conclusion: Grewia polysaccharide gum demonstrated good mucoadhesive properties, comparable to those of carbopol 971P, carboxymethylcellulose, guar gum and hydroxypropyl methylcellulose, and therefore, should be suitable for the formulation of retentive drug delivery devices. © Pharmacotherapy Group, Faculty of Pharmacy, University of Benin, Benin City.

Synthesis of highly efficient and recyclable visible-light responsive mesoporous g-C3N4 photocatalyst via facile template-free sonochemical route

Herein we demonstrate a facile template-free sonochemical strategy to synthesize mesoporous g-C3N4 with a high surface area and enhanced photocatalytic activity. The TEM and nitrogen adsorption–desorption studies confirm mesoporous structure in g-C3N4 body. The photocatalytic activity of mesoporous g-C3N4 is almost 5.5 times higher than that of bulk g-C3N4 under visible-light irradiation. The high photocatalytic performance of the mesoporous g-C3N4 was attributed to the much higher specific surface area, efficient adsorption ability and the unique interfacial mesoporous structure which can favour the absorption of light and separation of photoinduced electron–hole pairs more effectively. A possible photocatalytic mechanism was discussed by the radicals and holes trapping experiments. Interestingly, the synthesized mesoporous g-C3N4 possesses high reusability. Hence the mesoporous g-C3N4 can be a promising photocatalytic material for practical applications in water splitting as well as environmental remediation.

REST is a hypoxia-responsive transcriptional repressor

Cellular exposure to hypoxia results in altered gene expression in a range of physiologic and pathophysiologic states. Discrete cohorts of genes can be either up- or down-regulated in response to hypoxia. While the Hypoxia-Inducible Factor (HIF) is the primary driver of hypoxia-induced adaptive gene expression, less is known about the signalling mechanisms regulating hypoxiadependent gene repression. Using RNA-seq, we demonstrate that equivalent numbers of genes are induced and repressed in human embryonic kidney (HEK293) cells. We demonstrate that nuclear localization of the Repressor Element 1-Silencing Transcription factor (REST) is induced in hypoxia and that REST is responsible for regulating approximately 20% of the hypoxia-repressed genes. Using chromatin immunoprecipitation assays we demonstrate that REST-dependent gene repression is at least in part mediated by direct binding to the promoters of target genes. Based on these data, we propose that REST is a key mediator of gene repression in hypoxia.

Creating Responsive Information Systems with the Help of SSADM

In this paper, a program for a research is outlined. Firstly, the concept of responsive information systems is defined and then the notion of the capacity planning and software performance engineering is clarified. Secondly, the purpose of the proposed methodology of capacity planning, the interface to information systems analysis and development methodologies (SSADM), the advantage of knowledge-based approach is discussed. The interfaces to CASE tools more precisely to data dictionaries or repositories (IRDS) are examined in the context of a certain systems analysis and design methodology (e.g. SSADM).

The relationship of culturally responsive instruction and the reading comprehension and attitude of struggling urban adolescent readers

Culturally responsive instruction refers to the identification of relevant cultural aspects of students' lives and infusion of these into the curriculum. This instructional approach assumes that a culturally appropriate curriculum can potentially motivate, engage, and lead students to higher rates of achievement. This quasi-experimental study (N=44) investigated the relationship of culturally responsive instruction and the reading comprehension and attitude of struggling urban adolescent readers. The study incorporated the use of culturally responsive instruction using culturally relevant literature (CRL), the Bluford Series Novels, as authentic texts of instruction. Participants were seventh grade reading students at a Title I middle school in South Florida. After a baseline period, two different classes were taught for 8 weeks using different methods. One class formed the experimental group ( n=22) and the other class formed the comparison group (n =22). The CRI curriculum for the experimental group embraced the socio-cultural perspective through the use of small discussion groups in which students read and constructed meaning with peers through interaction with the Bluford Series Novels; gave written responses to multiple strategies according to SCRAP - Summarize, Connect, Reflect, Ask Questions, Predict; responded to literal and inferential questions, while at the same time validating their responses through evidence from the text. The Read XL (basal reader) curriculum of the comparison group utilized a traditional form of instruction which incorporated the reading of passages followed by responses to comprehension questions, and teacher-led whole group discussion. The main sources of data were collected from the Gates-MacGinitie Reading Tests, the Florida Assessments for Instruction in Reading (FAIR), and the Rhody Secondary Reading Attitude Assessment. Statistical analyses were performed using Repeated Measures ANOVAs. Findings from the study revealed that the experimental participants' reading attitudes and FAIR comprehension scores increased when compared to the comparison group. Overall, the results from the study revealed that culturally responsive instruction can potentially foster reading comprehension and a more positive attitude towards reading. However, a replication of this study in other settings with a larger, more randomized sample size and a greater ethnic variation is needed in order to make full generalizations.

The Roles of ‘Conventional’ and Demand-Responsive Bus Services

Purpose - The roles of ‘conventional’ (fixed-route and fixed-timetable) bus services is examined and compared to demand-responsive services, taking rural areas in England as the basis for comparison. It adopts a ‘rural’ definition of settlements under a population of 10,000. Design/methodology/approach - Evidence from the National Travel Survey, technical press reports and academic work is brought together to examine the overall picture. Findings - Inter-urban services between towns can provide a cost-effective way of serving rural areas where smaller settlements are suitably located. The cost structures of both fixed-route and demand-responsive services indicate that staff time and cost associated with vehicle provision are the main elements. Demand-responsive services may enable larger areas to be covered, to meet planning objectives of ensuring a minimum of level of service, but experience often shows high unit cost and public expenditure per passenger trip. Economic evaluation indicates user benefits per passenger trip of similar magnitude to existing average public expenditure per trip on fixed-route services. Considerable scope exists for improvements to conventional services through better marketing and service reliability. Practical implications - The main issue in England is the level of funding for rural services in general, and the importance attached to serving those without access to cars in such areas. Social implications - The boundary between fixed-route and demand-responsive operation may lie at relatively low population densities. Originality/value - The chapter uses statistical data, academic research and operator experience of enhanced conventional bus services to provide a synthesis of outcomes in rural areas.

An Infection-Responsive Approach to Reduce Bacterial Adhesion in Urinary Biomaterials

Infection is an inevitable consequence of chronic urinary catheterisation, with associated problems of recurrent catheter encrustation and blockage experienced by approximately 50% of all long-term catheterised patients. In this work we have exploited, for the first time, the reported pathogen-induced elevation of urine pH as a trigger for ‘intelligent’ antimicrobial release from novel hydrogel drug delivery systems of 2-hydroxyethyl methacrylate and vinyl-functionalised nalidixic acid derivatives, developed as candidate infection-resistant urinary catheter coatings. Demonstrating up to 20-fold faster rates of drug release at pH 10, representing infected urine pH, than at pH 7, and achieving reductions of up to 96.5% in in vitro bacterial adherence, our paradigm of pH-responsive drug delivery, which requires no external manipulation, therefore represents a promising development towards the prevention of catheter-associated urinary tract infections (CAUTIs) in vivo.