Preparation and In-vitro Evaluation of Gastroretentive Bupropion Hydrochloride Tablets

Purpose: To develop a gastroretentive formulation of bupropion hydrochloride in the form of floating tablets.Methods: Floating tablets were prepared by wet granulation method using various amounts of sodium carboxymethycellulose (NaCMC), different molecular weight grade of hydroxypropyl methylcellulose (HPMC) and varying amounts of fillers (microcrystalline cellulose, lactose and tricalcium phosphate). Sodium bicarbonate was also incorporated as the gas-generating agent. The formulations were tested for their physical properties, floating lag time, duration of floating and in-vitro drug release.Results: All the tablet formulations containing either HPMC K4M or HPMC K15M as the sustained release polymer together with either microcrystalline cellulose (MCC) or lactose, floated in the release medium for > 10 h. Tablets prepared with MCC released ≥ 79 % of the drug after 10 h, while those prepared with lactose released ≥ 85 % of the drug within the same period. Tablets containing NaCMC alone did not show good floating properties but when HPMC K4M was also incorporated at certain ratios, tablets with good floating behavior and suitable drug release patterns were produced. Drug release kinetic studies showed that formulations fitted best to the Higuchi model.Conclusion: The developed floating tablets of bupropion HCl exhibited prolonged drug release for ≥ 10 h, and, thus may improve bioavailability and minimize fluctuations in plasma drug concentration

Investigating the sourdough potential for enhance microbiological shelf life and roasty aroma of traditional Lavash bread

In this study, potential effects of sourdough on microbiological shelf life and roasty aroma of traditional Lavash bread were studied. For investigating the biopreservation effect of sourdough, after intentional contamination of flour with hygiene indicator microorganisms that cause mouldiness and ropiness, survival curves of these microorganisms versus different sourdough fermentation times and temperatures, at finished-products were determined. Influence of sourdough fermentation conditions on crust roasty aroma was determined by gas chromatography and 2-acetyl 2-thiazoline was selected as standard compound for this aroma. The results showed that by increasing sourdough fermentation time and temperature, survival of indicator microorganisms in finished-products were decreased. But intensity of crust roasty aroma did not have the same profile. Therefore, process requirements for optimum microbiological shelf life and roasty aroma were different, which should be taken into account in designing sourdough baking processes.Key words: Lavash bread, sourdough, microbiological shelf life, roasty aroma

The principles of ultra high pressure technology and its application in food processing/preservation: A review of microbiological and quality aspects

Consumers have a growing preference for convenient, fresh-like, healthy, palatable, additive-free, highquality and microbiologically safe food products. However, as food deterioration is constant threatalong the entire food chain, food preservation remains as necessary today as in the past. The food industry has responded by applying a number of new technologies including high hydrostatic pressurefor food processing and preservation. In addition, food scientists have demonstrated the feasibility of industrial-scale high pressure processing. High pressure processing is one of the emergingtechnologies to be studied as an alternative to classical thermal processing of food. This ‘clean’ technology offers an effective and safe method of modifying protein structure, enzyme inactivation, andformation of chemical compounds. In addition the study of the effects of high pressure on biological materials has received a great deal of attention in recent years. During the last decade, numerouspublications that describe the influence of pressure on various constituents and contaminants of foods such as spoilage microorganisms, food pathogens, enzymes and food proteins have appeared in the literature. This paper reviews the literature on high pressure application in food industry most notably it covers various facets of high pressure technology, which is, history, concepts and principles underlying the application of this technology,  hysicochemical, chemical, microbiological aspects of high pressurein the viewpoint of food technology

Neural Correlates of Enhanced Visual Attentional Control in Action Video Game Players: An Event-Related Potential Study

Action video game players (AVGPs) outperform non-action video game players (NAVGPs) on a range of perceptual and attentional tasks. Although several studies have reported neuroplastic changes within the frontoparietal networks of attention in AVGPs, little is known about possible changes in attentional modulation in low-level visual areas. To assess the contribution of these different levels of neural processing to the perceptual and attentional enhancements noted in AVGPs, visual event-related potentials (ERPs) were recorded from 14 AVGPs and 14 NAVGPs during a target discrimination task that required participants to attend to rapid sequences of Gabor patches under either focused or divided attention conditions. AVGPs responded faster to target Gabors in the focused attention condition compared with the NAVGPs. Correspondingly, ERPs to standard Gabors revealed a more pronounced negativity in the time range of the parietally generated anterior N1 component in AVGPs compared with NAVGPs during focused attention. In addition, the P2 component of the visual ERP was more pronounced in AVGPs than in NAVGPs over the hemisphere contralateral to the stimulus position in response to standard Gabors. Contrary to predictions, however, attention-modulated occipital components generated in the low-level extrastriate visual pathways, including the P1 and posterior N1, showed no significant group differences. Thus, the main neural signature of enhanced perceptual and attentional control functions in AVGPs appears linked to an attention-dependent parietal process, indexed by the anterior N1 component, and possibly to more efficient higher-order perceptual processing, indexed by the P2 component

Expression of interfacial Seebeck coefficient through grain boundary engineering with multi-layer graphene nanoplatelets

Expression of energy filtering to boost thermoelectric performance through grain boundary engineering utilising graphene.</p

Cancer somatic mutations cluster in a subset of regulatory sites predicted from the ENCODE data

Background: Transcriptional regulation of gene expression is essential for cellular differentiation and function, and defects in the process are associated with cancer. The ENCODE project has mapped potential regulatory sites across the complete genome in many cell types, and these regions have been shown to harbour many of the somatic mutations that occur in cancer cells, suggesting that their effects may drive cancer initiation and development. The ENCODE data suggests a very large number of regulatory sites, and methods are needed to identify those that are most relevant and to connect them to the genes that they control. Methods: Predictive models of gene expression were developed by integrating the ENCODE data for regulation, including transcription factor binding and DNase1 hypersensitivity, with RNA-seq data for gene expression. A penalized regression method was used to identify the most predictive potential regulatory sites for each transcript. Known cancer somatic mutations from the COSMIC database were mapped to potential regulatory sites, and we examined differences in the mapping frequencies associated with sites chosen in regulatory models and other (rejected) sites. The effects of potential confounders, for example replication timing, were considered. Results: Cancer somatic mutations preferentially occupy those regulatory regions chosen in our models as most predictive of gene expression. Conclusion: Our methods have identified a significantly reduced set of regulatory sites that are enriched in cancer somatic mutations and are more predictive of gene expression. This has significance for the mechanistic interpretation of cancer mutations, and the understanding of genetic regulation

The risk of subjective symptoms in mobile phone users in Poland – An epidemiological study

Objectives: To assess the type and incidence of subjective symptoms related to the use of mobile phones in Polish users. Material and Methods: The study was conducted in 2005 using a questionnaire survey. Although it has been quite a long time, up to now, no such data have been published for Poland. The questionnaire consisted of 53 questions concerning sex, age, education, general health, characteristics of a mobile phone (hand-held, loud-speaking unit) as well as the habits associated with its use (frequency and duration of calls, text messages, etc.) and complaints associated with using a mobile phone. Results: As many as 1800 questionnaires were sent. The response was obtained from 587 subjects aged 32.6±11.3 (48.9% women, 51.1% men); the age did not differ significantly between men and women. The subjects owned a cell phone for an average of 3 years. Majority of the respondents used the phone intensively, i.e. daily (74%) or almost daily (20%). Headaches were reported significantly more often by the people who talked frequently and long in comparison with other users (63.2% of the subjects, p = 0.0029), just like the symptoms of fatigue (45%, p = 0.013). Also, the feeling of warmth around the ear and directly to the auricle was reported significantly more frequently by the intensive mobile phone users, compared with other mobile phone users (47.3%, p = 0.00004 vs. 44.6%, p = 0.00063, respectively). Most symptoms appeared during or immediately after a call and disappeared within 2 h after the call. Continuous headache, persisting for longer than 6 h since the end of a call, was reported by 26% of the subjects. Conclusions: Our results show that the mobile phone users may experience subjective symptoms, the intensity of which depends on the intensity of use of mobile phones

Normalizing single-cell RNA sequencing data: challenges and opportunities

Single-cell transcriptomics is becoming an important component of the molecular biologist's toolkit. A critical step when analyzing data generated using this technology is normalization. However, normalization is typically performed using methods developed for bulk RNA sequencing or even microarray data, and the suitability of these methods for single-cell transcriptomics has not been assessed. We here discuss commonly used normalization approaches and illustrate how these can produce misleading results. Finally, we present alternative approaches and provide recommendations for single-cell RNA sequencing users

Paroxysmal nocturnal hemoglobinuria (PNH): higher sensitivity and validity in diagnosis and serial monitoring by flow cytometric analysis of reticulocytes

Flow cytometric analysis of GPI-anchored proteins (GPI-AP) is the gold standard for diagnosis of paroxysmal nocturnal hemoglobinuria (PNH). Due to therapy options and the relevance of GPI-deficient clones for prognosis in aplastic anaemia detection of PNH is gaining importance. However, no generally accepted standard has been established. This study analysed the usefulness of a flow cytometric panel with CD58, CD59 on reticulocytes and erythrocytes, CD24/CD66b and CD16, FLAER on granulocytes and CD14, and CD48 on monocytes. Actual cut-off (mean + 2 SD) for GPI-deficient cells was established in healthy blood donors. We studied 1,296 flow cytometric results of 803 patients. Serial monitoring was analysed during a median follow-up of 1,039 days in 155 patients. Of all, 22% and 48% of 155 follow-up patients. showed significant GPI-AP-deficiency at time of initial analyses. During follow-up in 9%, a new PNH diagnosis, and in 28%, a significant change of size or lineage involvement was demonstrated. Highly significant correlations for GPI-AP deficiency were found within one cell lineage (r2 = 0.61–0.95, p < 0.0001) and between the different cell lineages (r2 = 0.49–0.88, p < 0.0001). Especially for detection of small GPI-deficient populations, reticulocytes and monocytes proved to be sensitive diagnostic tools. Our data showed superiority of reticulocyte analyses compared with erythrocyte analyses due to transfusion and hemolysis independency especially in cases with small GPI-deficient populations. In conclusion, a screening panel of at least two different GPI-AP markers on granulocytes, erythrocytes, and reticulocytes provides a simple and rapid method to detect even small GPI-deficient populations. Among the markers in our panel, CD58 and CD59 on reticulocytes, CD24/66b, and eventually FLAER on granulocytes as well as CD14 on monocytes were most effective for flow cytometric diagnosis of GPI deficiency