Encapsulation of Local Anesthetic Bupivacaine in Biodegradable Poly(DL-lactide-co-glycolide) Nanospheres: Factorial Design, Characterization and Cytotoxicity Studies

Local anesthetic agents cause temporary blockade of nerve impulses productiong insensitivity to painful stimuli in the area supplied by that nerve. Bupivacaine (BVC) is an amide-type local anesthetic widely used in surgery and obstetrics for sustained peripheral and central nerve blockade. in this study, we prepared and characterized nanosphere formulations containing BVC. To achieve these goals, BVC loaded poly(DL-lactide-co-glycolide) (PLGA) nanospheres (NS) were prepared by nanopreciptation and characterized with regard to size distribution, drug loading and cytotoxicity assays. The 2(3-1) factorial experimental design was used to study the influence of three different independent variables on nanoparticle drug loading. BVC was assayed by HPLC, the particle size and zeta potential were determined by dynamic light scattering. BVC was determined using a combined ultrafiltration-centrifugation technique. The results of optimized formulations showed a narrow size distribution with a polydispersivity of 0.05%, an average diameter of 236.7 +/- 2.6 nm and the zeta potential -2.93 +/- 1,10 mV. In toxicity studies with fibroblast 3T3 cells, BVC loaded-PLGA-NS increased cell viability, in comparison with the effect produced by free BVC. In this way, BVC-loaded PLGA-NS decreased BVC toxicity. The development of BVC formulations in carriers such as nanospheres could offer the possibility of controlling drug delivery in biological systems, prolonging the anesthetic effect and reducing toxicity.

Development and optimization of fluoxetine orally disintegrating tablets using Box-Behnken design

Purpose: To develop and optimise some variables that influence fluoxetine orally disintegrating tablets (ODTs) formulation. Methods: Fluoxetine ODTs tablets were prepared using direct compression method. Three-factor, 3- level Box-Behnken design was used to optimize and develop fluoxetine ODT formulation. The design suggested 15 formulations of different lubricant concentration (X1), lubricant mixing time (X2), and compression force (X3) and then their effect was monitored on tablet weight (Y1), thickness (Y2), hardness (Y3), % friability (Y4), and disintegration time (Y5). Results: All powder blends showed acceptable flow properties, ranging from good to excellent. The disintegration time (Y5) was affected directly by lubricant concentration (X1). Lubricant mixing time (X2) had a direct effect on tablet thickness (Y2) and hardness (Y3), while compression force (X3) had a direct impact on tablet hardness (Y3), % friability (Y4) and disintegration time (Y5). Accordingly, Box-Behnken design suggested an optimized formula of 0.86 mg (X1), 15.3 min (X2), and 10.6 KN (X3). Finally, the prediction error percentage responses of Y1, Y2, Y3, Y4, and Y5 were 0.31, 0.52, 2.13, 3.92 and 3.75 %, respectively. Formula 4 and 8 achieved 90 % of drug release within the first 5 min of dissolution test. Conclusion: Fluoxetine ODT formulation has been developed and optimized successfully using Box- Behnken design and has also been manufactured efficiently using direct compression technique.

Cultura e bem estar no trabalho: o papel do ajustamento pessoa-organização num estudo experimental

Com a crescente importância da vida laboral torna-se necessário o estudo de variáveis que aprimorem o trabalho individual e das empresas. Adotando um design experimental, com a manipulação de quatro orientações culturais e com uma amostra de 150 trabalhadores de uma empresa multinacional, este estudo foi realizado com o objetivo de avaliar o impacto da cultura organizacional no bem-estar (afetivo e cognitivo) laboral, o impacto do ajustamento pessoa-organização no bem-estar do trabalhador e a forma como a relação entre a cultura organizacional e o bem-estar é moderada pelo ajustamento pessoa-organização. Os resultados revelaram que quanto mais elevados os níveis de ajustamento pessoa-organização, maior o conforto, entusiasmo, bem-estar geral e satisfação. Quanto à cultura organizacional, embora não se tenham verificado efeitos de interação significativos, as culturas de apoio e inovação revelam níveis superiores de conforto, entusiasmo, bem-estar afetivo geral, e satisfação laboral dos indivíduos, ao contrário das culturas de regras e objetivos; Culture and Well-Being at Work: the role of person - organization fit in an experimental study Abstract: With the growing importance of working life it is necessary to study the variables to improve individual work and business. Adopting an experimental design, handling four cultural orientations and a sample of 150 employees of a multinational company, this study was designed in order to explore the impact of organizational culture on well-being (affective and cognitive) labor, the impact of person-organization fit in the worker's well-being and how the relationship between organizational culture and well-being is moderated by person-organization fit. The results revealed that the higher the adjustment levels of person-organization, the greater comfort, enthusiasm, general well-being and satisfaction will be. As for the organizational culture, although there were not verified significant interaction effects, cultures of support and innovation promote comfort, enthusiasm, general emotional well-being and job satisfaction of individuals, unlike the cultures of rules and objectives.

Consumer appraisals of mobile marketing communications

This paper reports on a study that investigates the emotions elicited from appraising SMS-based mobile marketing (m-marketing) communications under three marketing conditions: product consistency, incentives and permission giving. Results from the experimental design show that appraising m-marketing communications elicits both single emotions and mixed emotions; that is, a mixture of positive and negative emotions in the same response. Additionally, the results show that the influence of specific marketing conditions may increase or reduce the intensity of the emotions elicited. This study contributes to marketing practice by examining consumer appraisals of m-marketing communications under different combinations of marketing conditions. The results provide insights into which emotions are likely to be elicited as a result, and how a specific marketing condition might influence their levels of intensity. The study contributes to marketing theory also through combining appraisal theory with Richins (1997) consumption emotion set.

An Investigation of Cognitive, Emotional and Negative Behavioural Responses to Service Recovery Strategies

Despite the best intentions of service providers and organisations, service delivery is rarely error-free. While numerous studies have investigated specific cognitive, emotional or behavioural responses to service failure and recovery, these studies do not fully capture the complexity of the services encounter. Consequently, this research develops a more holistic understanding of how specific service recovery strategies affect the responses of customers by combining two existing models—Smith & Bolton’s (2002) model of emotional responses to service performance and Fullerton and Punj’s (1993) structural model of aberrant consumer behaviour—into a conceptual framework. Specific service recovery strategies are proposed to influence consumer cognition, emotion and behaviour. This research was conducted using a 2x2 between-subjects quasi-experimental design that was administered via written survey. The experimental design manipulated two levels of two specific service recovery strategies: compensation and apology. The effect of the four recovery strategies were investigated by collecting data from 18-25 year olds and were analysed using multivariate analysis of covariance and multiple regression analysis. The results suggest that different service recovery strategies are associated with varying scores of satisfaction, perceived distributive justice, positive emotions, negative emotions and negative functional behaviour, but not dysfunctional behaviour. These finding have significant implications for the theory and practice of managing service recovery.

Consumers' emotional appraisals and action tendencies arising from mobile viral marketing

This study examines consumers' emotional responses to receiving viral mobile marketing communications in comparison to receiving mobile marketing communications where permission has not been given. The study also examines the relationship between these experienced emotions and what action tendencies consumers might consider as a result of these emotions, as well as how they attribute causality for their emotions. Using scenarios in an experimental design, the findings show that there are differences in consumer emotions as a result of the two marketing approaches. The findings also identify relationships between consumers' causal attributions and action tendencies in relation to themselves, the friend sending the viral m-marketing communication and the company involved.

Nursing students’ knowledge and practice of infection control precautions : an educational intervention

Aim. This paper is a report of the effectiveness of a purpose-designed education program in improving undergraduate nursing students’ understanding and practice of infection control precautions. Background. The severe acute respiratory syndrome outbreak in 2003 highlighted that healthcare workers were under-prepared for such an epidemic. While many in-service education sessions were arranged by institutions in response to the outbreak, preservice nursing education has overlooked preparation for handling such infectious disease epidemics. Method. A quasi-experimental design was used and a 16-hour, purpose-designed infection control education programme was implemented for preservice nursing students in southern Taiwan. Self-administered questionnaires were distributed at three time points during the period September 2005 to April 2006 to examine the sustainability and effectiveness of the intervention. Results. A total of 175 preservice nursing students participated in the study. Following the education programme, students in the intervention group showed a statistically significant improvement across time in their knowledge of these precautions [F(2, 180) = 13Æ53, P < 0Æ001] and confidence in resolving infectionrelated issues [F(1Æ79, 168Æ95) = 3Æ24] when compared with those in the control group. Conclusion. To improve nursing students’ capacity in responding to infectious epidemics, an educational programme that integrates the theme of infection precautions, learning theory and teaching strategies is recommended for all nursing institutes.

Fiji pre-service primary teachers' understanding of physical science : a cultural perspective

Science and technology are promoted as major contributors to national development. Consequently, improved science education has been placed high on the agenda of tasks to be tackled in many developing countries, although progress has often been limited. In fact there have been claims that the enormous investment in teaching science in developing countries has basically failed, with many reports of how efforts to teach science in developing countries often result in rote learning of strange concepts, mere copying of factual information, and a general lack of understanding on the part of local students. These generalisations can be applied to science education in Fiji. Muralidhar (1989) has described a situation in which upper primary and middle school students in Fiji were given little opportunity to engage in practical work; an extremely didactic form of teacher exposition was the predominant method of instruction during science lessons. He concluded that amongst other things, teachers' limited understanding, particularly of aspects of physical science, resulted in their rigid adherence to the text book or the omission of certain activities or topics. Although many of the problems associated with science education in developing countries have been documented, few attempts have been made to understand how non-Western students might better learn science. This study addresses the issue of Fiji pre-service primary teachers' understanding of a key aspect of physical science, namely, matter and how it changes, and their responses to learning experiences based on a constructivist epistemology. Initial interviews were used to probe pre-service primary teachers' understanding of this domain of science. The data were analysed to identify students' alternative and scientific conceptions. These conceptions were then used to construct Concept Profile Inventories (CPI) which allowed for qualitative comparison of the concepts of the two ethnic groups who took part in the study. This phase of the study also provided some insight into the interaction of scientific information and traditional beliefs in non-Western societies. A quantitative comparison of the groups' conceptions was conducted using a Science Concept Survey instrument developed from the CPis. These data provided considerable insight into the aspects of matter where the pre-service teachers' understanding was particularly weak. On the basis of these preliminary findings, a six-week teaching program aimed at improving the students' understanding of matter was implemented in an experimental design with a group of students. The intervention involved elements of pedagogy such as the use of analogies and concept maps which were novel to most of those who took part. At the conclusion of the teaching programme, the learning outcomes of the experimental group were compared with those of a control group taught in a more traditional manner. These outcomes were assessed quantitatively by means of pre- and post-tests and a delayed post-test, and qualitatively using an interview protocol. The students' views on the various teaching strategies used with the experimental group were also sought. The findings indicate that in the domain of matter little variation exists in the alternative conceptions held by Fijian and Indian students suggesting that cultural influences may be minimal in their construction. Furthermore, the teaching strategies implemented with the experimental group of students, although largely derived from Western research, showed considerable promise in the context of Fiji, where they appeared to be effective in improving the understanding of students from different cultural backgrounds. These outcomes may be of significance to those involved in teacher education and curriculum development in other developing countries.

In vivo knockdown of the androgen receptor results in growth inhibition and regression of well-established, castration-resistant prostate tumours

Purpose: Progression to the castration-resistant state is the incurable and lethal end stage of prostate cancer, and there is strong evidence that androgen receptor (AR) still plays a central role in this process. We hypothesize that knocking down AR will have a major effect on inhibiting growth of castration-resistant tumors. Experimental Design: Castration-resistant C4-2 human prostate cancer cells stably expressing a tetracycline-inducible AR-targeted short hairpin RNA (shRNA) were generated to directly test the effects of AR knockdown in C4-2 human prostate cancer cells and tumors. Results:In vitro expression of AR shRNA resulted in decreased levels of AR mRNA and protein, decreased expression of prostate-specific antigen (PSA), reduced activation of the PSA-luciferase reporter, and growth inhibition of C4-2 cells. Gene microarray analyses revealed that AR knockdown under hormone-deprived conditions resulted in activation of genes involved in apoptosis, cell cycle regulation, protein synthesis, and tumorigenesis. To ensure that tumors were truly castration-resistant in vivo, inducible AR shRNA expressing C4-2 tumors were grown in castrated mice to an average volume of 450 mm3. In all of the animals, serum PSA decreased, and in 50% of them, there was complete tumor regression and disappearance of serum PSA. Conclusions: Whereas castration is ineffective in castration-resistant prostate tumors, knockdown of AR can decrease serum PSA, inhibit tumor growth, and frequently cause tumor regression. This study is the first direct evidence that knockdown of AR is a viable therapeutic strategy for treatment of prostate tumors that have already progressed to the castration-resistant state.

Writing stories to enhance scientific literacy

In response to international concerns about scientific literacy and students’ waning interest in school science, this study investigated the effects of a science-writing project about the socioscientific issue of biosecurity on the development of students’ scientific literacy. Students generated two BioStories each that merged scientific information with the narrative storylines in the project. The study was conducted in two phases. In the exploratory phase, a qualitative case study of a 6th grade class involving classroom observations and interviews informed the design of the second, confirmatory phase of the study, which was conducted at a different school. This phase involved a mixed methods approach featuring a quasi-experimental design with two classes of Australian middle school students (i.e., 6th grade, 11 years of age, n=55). The results support the argument that writing the sequence of stories helped the students become more familiar with biosecurity issues, develop a deeper understanding of related biological concepts, and improve their interest in science. On the basis of these findings, teachers should be encouraged to engage their students in the practice of writing about socioscientific issues (SSI) in a way that integrates scientific information into narrative storylines. Extending the practice to older students, and exploring additional issues related to writing about SSI are recommended for further research.

The impact of online reviews on hotel booking intentions and trust

A growing reliance on the Internet as an information source when making choices about tourism products raises the need for more research into electronic word of mouth. Within a hotel context, this study explores the role of four key factors that influence perceptions of trust and consumer choice. An experimental design is used to investigate four independent variables: the target of the review (core or interpersonal); overall valence of a set of reviews (positive or negative); framing of reviews (what comes first: negative or positive information); and whether or not a consumer generated numerical rating is provided together with the written text. Consumers seem to be more influenced by early negative information, especially when the overall set of reviews is negative. However, positively framed information together with numerical rating details increases both booking intentions and consumer trust. The results suggest that consumers tend to rely on easy-to-process information, when evaluating a hotel based upon reviews. Higher levels of trust are also evident when a positively framed set of reviews focused on interpersonal service.

An investigation of the effect of individual cognitive preferences on learning through computer-based instruction

This paper reports a study investigating the effect of individual cognitive styles on learning through computer-based instruction. The study adopted a quasi-experimental design involving four groups which were presented with instructional material that either matched or mismatched with their preferred cognitive styles. Cognitive styles were measured by cognitive style assessment software (Riding, 1991). The instructional material was designed to cater for the four cognitive styles identified by Riding. Students' learning outcomes were measured by the time taken to perform test tasks and the number of marks scored. The results indicate no significant difference between the matched and mismatched groups on both time taken and scores on test tasks. However, there was significant difference between the four cognitive styles on test score. The Wholist/Verbaliser group performed better then all other groups. There was no significant difference between the other groups. An analysis of the performance on test task by each cognitive style showed significant difference between the groups on recall, labelling and explanation. Difference between the cognitive style groups did not reach significance level for problem-solving tasks. The findings of the study indicate a potential for cognitive style to influence learning outcomes measured by performance on test tasks.

Prediction model of the buildup of volatile organic compounds on urban roads

A model to predict the buildup of mainly traffic-generated volatile organic compounds or VOCs (toluene, ethylbenzene, ortho-xylene, meta-xylene, and para-xylene) on urban road surfaces is presented. The model required three traffic parameters, namely average daily traffic (ADT), volume to capacity ratio (V/C), and surface texture depth (STD), and two chemical parameters, namely total suspended solid (TSS) and total organic carbon (TOC), as predictor variables. Principal component analysis and two phase factor analysis were performed to characterize the model calibration parameters. Traffic congestion was found to be the underlying cause of traffic-related VOC buildup on urban roads. The model calibration was optimized using orthogonal experimental design. Partial least squares regression was used for model prediction. It was found that a better optimized orthogonal design could be achieved by including the latent factors of the data matrix into the design. The model performed fairly accurately for three different land uses as well as five different particle size fractions. The relative prediction errors were 10–40% for the different size fractions and 28–40% for the different land uses while the coefficients of variation of the predicted intersite VOC concentrations were in the range of 25–45% for the different size fractions. Considering the sizes of the data matrices, these coefficients of variation were within the acceptable interlaboratory range for analytes at ppb concentration levels.

Consumer misbehaviour during professional service encounters

To date, consumer behaviour research is still over-focused on the functional rather than the dysfunctional. Both empirical and anecdotal evidence suggest that service organisations are burdened with the concept of consumer sovereignty, while consumers freely flout the ‘rules’ of social exchange and behave in deviant and dysfunctional ways. Further, the current scope of consumer misbehaviour research suggests that the phenomenon has principally been studied in the context of economically-focused exchange. This limits our current understanding of consumer misbehaviour to service encounters that are more transactional than relational in nature. Consequently, this thesis takes a Social Exchange approach to consumer misbehaviour and reports a three-stage multi-method study that examined the nature and antecedents of consumer misbehaviour in professional services. It addresses the following broad research question: What is the nature of consumer misbehaviour during professional service encounters? Study One initially explored the nature of consumer misbehaviour in professional service encounters using critical incident technique (CIT) within 38 semi-structured in-depth interviews. The study was designed to develop a better understanding of what constitutes consumer misbehaviour from a service provider’s perspective. Once the nature of consumer misbehaviour had been qualified, Study Two focused on developing and refining calibrated items that formed Guttman-like scales for two consumer misbehaviour constructs: one for the most theoretically-central type of consumer misbehaviour identified in Study One (i.e. refusal to participate) and one for the most well-theorised and salient type of consumer misbehaviour (i.e. verbal abuse) identified in Study One to afford a comparison. This study used Rasch modelling to investigate whether it was possible to calibrate the escalating severity of a series of decontextualised behavioural descriptors in a valid and reliable manner. Creating scales of calibrated items that capture the variation in severity of different types of consumer misbehaviour identified in Study One allowed for a more valid and reliable investigation of the antecedents of such behaviour. Lastly, Study Three utilised an experimental design to investigate three key antecedents of consumer misbehaviour: (1) the perceived quality of the service encounter [drawn from Fullerton and Punj’s (1993) model of aberrant consumer behaviour], (2) the violation of consumers’ perceptions of justice and equity [drawn from Rousseau’s (1989) Psychological Contract Theory], and (3) consumers’ affective responses to exchange [drawn from Weiss and Cropanzano’s (1996) Affective Events Theory]. Investigating three key antecedents of consumer misbehaviour confirmed the newly-developed understanding of the nature of consumer misbehaviour during professional service encounters. Combined, the results of the three studies suggest that consumer misbehaviour is characteristically different within professional services. The most salient and theoretically-central behaviours can be measured using increasingly severe decontextualised behavioural descriptors. Further, increasingly severe forms of consumer misbehaviour are likely to occur as a response to consumer anger at low levels of interpersonal service quality. These findings have a range of key implications for both marketing theory and practice.

Brivanib alaninate, a dual inhibitor of vascular endothelial growth factor receptor and fibroblast growth factor receptor tyrosine kinases, induces growth inhibition in mouse models of human hepatocellular carcinoma

PURPOSE: Hreceptor (VEGFR) and FGF receptor (FGFR) signaling pathways. EXPERIMENTAL DESIGN: Six different s.c. patient-derived HCC xenografts were implanted into mice. Tumor growth was evaluated in mice treated with brivanib compared with control. The effects of brivanib on apoptosis and cell proliferation were evaluated by immunohistochemistry. The SK-HEP1 and HepG2 cells were used to investigate the effects of brivanib on the VEGFR-2 and FGFR-1 signaling pathways in vitro. Western blotting was used to determine changes in proteins in these xenografts and cell lines. RESULTS: Brivanib significantly suppressed tumor growth in five of six xenograft lines. Furthermore, brivanib-induced growth inhibition was associated with a decrease in phosphorylated VEGFR-2 at Tyr(1054/1059), increased apoptosis, reduced microvessel density, inhibition of cell proliferation, and down-regulation of cell cycle regulators. The levels of FGFR-1 and FGFR-2 expression in these xenograft lines were positively correlated with its sensitivity to brivanib-induced growth inhibition. In VEGF-stimulated and basic FGF stimulated SK-HEP1 cells, brivanib significantly inhibited VEGFR-2, FGFR-1, extracellular signal-regulated kinase 1/2, and Akt phosphorylation. CONCLUSION: This study provides a strong rationale for clinical investigation of brivanib in patients with HCC.