Regulating the molar fraction of 4-hydroxybutyrate in Poly(3-hydroxybutyrate-co-4-hydroxybutyrate) by biological fermentation and enzymatic degradation

The regulation of 4-hydroxybutyrate (4HB) molar fraction in the poly(3-hydroxybutyrate-co-4-hydroxybutyrate) [P(3HB-co-4HB)] of a local isolate Cupriavidus sp. USMAA1020 was attempted by employing a feeding strategy through fed-batch fermentation in 100-L fermenter. The growth of Cupriavidus sp. USMAA1020 was enhanced by frequently feeding carbon and nitrogen at a ratio of 5 (C/N 5) using a DO-stat with cascade mode at 20% (v/v) dissolved oxygen (DO). The feeding of C/N 5 and the use of the DOstat mode were able to regulate the 4HB composition from 0–67 mol% by sequential feeding of c-butyrolactone and supplementing oleic acid. A high 4HB molar fraction of 67 mol% with a PHA concentration of 5.2 g/L was successfully obtained by employing this feeding strategy. Notably, enzymatic degradation carried out enhanced the 4HB composition of the copolymer synthesized. PHB depolymerase enzyme from Acidovorax sp. was used to degrade this P(3HB-co-70-mol%4HB) copolymer and the 4HB composition could be increased up to 83 mol%. The degradation process was observed by monitoring the timedependent change in the weight loss of copolymer films. The percentage of weight loss of solvent-cast film increased proportionally up to 19% within 3 h, whereas salt-leached films showed 90% of weight loss within 3 h of incubation and were completely degraded by 4 h. The molecular weight (Mn) of the films treated with enzyme demonstrated a slight decrease. SEM observation exhibited a rough surface morphology of the copolymer degraded with depolymerase enzyme

Preparation and characterization of polyhydroxyalkanoates macroporous scaffold through enzyme-mediated modifications

Polyhydroxyalkanoates (PHAs) are hydrophobic biodegradable thermoplastics that have received considerable attention in biomedical applications due to their biocompatibility, mechanical properties, and biodegradability. In this study, the degradation rate was regulated by optimizing the interaction of parameters that influence the enzymatic degradation of P(3HB) film using response surface methodology (RSM). The RSM model was experimentally validated yielding a maximum 21 % weight loss, which represents onefold increment in percentage weight loss in comparison with the conventional method. By using the optimized condition, the enzymatic degradation by an extracellular PHA depolymerase from Acidovorax sp. DP5 was studied at 37 °C and pH 9.0 on different types of PHA films with various monomer compositions. Surface modification of scaffold was employed using enzymatic technique to create highly porous scaffold with a large surface to volume ratio, which makes them attractive as potential tissue scaffold in biomedical field. Scanning electron microscopy revealed that the surface of salt-leached films was more porous compared with the solvent-cast films, and hence, increased the degradation rate of salt-leached films. Apparently, enzymatic degradation behaviors of PHA films were determined by several factors such as monomer composition, crystallinity, molecular weight, porosity, and roughness of the surface. The hydrophilicity and water uptake of degraded salt-leached film of P(3HB-co-70%4HB) were enhanced by incorporating chitosan or alginate. Salt-leached technique followed by partial enzymatic degradation would enhance the cell attachment and suitable for biomedical as a scaffold

Evaluación de un protector antipolvo electrostático de carga automática para aplicaciones de células solares en el clima exterior de Bagdad

Introduction: It is well known that the biggest problem facing the utilizing of solar cell Panels in Baghdad is the unpredictable dusty weather through the days of year. This big problem is not easy to overcome due to the frequent dust accumulations and the high cost of cleaning and other maintenance problems. Dust problems are increasing due to global warming. In Baghdad city, where solar radiation is intense and available almost throughout the year, Deposition of dust on the panels could severely minimize solar-to power output efficiency. There are many methods for dust removing from surfaces like the natural dust removal of wind, mechanical dust removing, super-hydrophobic on solar panel surface, and the electrostatic method which is adopted in this work. The dust particles will be charged statistically by rolling on the surface of the solar panels they will have the same electric charge and the electrostatic forces between them are repulsion. Hence, the dust particles will float away from the solar panels. Materials and Methods: A self-charging transparent conductive glass is prepared by spraying a thin film (141 nm thickness) of a Tin dioxide (SnO2) solution on a glass substrate (12x12 cm2). The dust shield is connected to an electronic charging circuit. The shield is located on the top of a silicon solar cell. The novel idea is that the shield is electrically supplied by the solar cell itself whereas D.C. current from the solar cell itself is used to charge the conductive glass, which is located on the top surface of the cell. Results and Discussion: A test was done for dust removing from a Silicon solar cell by electrostatic repulsion method, considering matching the spectral response region of the Siliconsolar cells with the film transmittance spectral region (400 -700 nm). The transmittance value is between (92 – 95)% and results are compared withan identical reference solar cell. Results show a good response as the calculated clearing factor value increases due to the cell efficiency increment.Also, the clearing factor is discussed as a function of outdoor temperature to show a direct proportionality, while the environmental humidity showed an inverse proportionality. Conclusions: A self-cleaning method for a solar cell is successfully introduced via a conductive glass. tests were carried outdoor in Baghdad city. Results showed that there is a direct proportionality between both: the clearing factor and the efficiency gain with the ambient temperature. The ambient humidity showed indirect proportionality with system efficiency (clearing factor and efficiency gain show reduction as the humidity percentage increases)

Types of glaucoma in a university health centre in Al‑Ahsa, Saudi Arabia: a pilot study

Objective: The objective was to assess the profile of different types of glaucoma in a University Health Centre in Al‑Ahsa, Saudi Arabia.Materials and Methods: It is a retrospective study in which the files of the patients at King Faisal University Health Centre were reviewed. The data collected included: Age, sex, race, visual acuity, the slit lamp examination findings, the intraocular pressure (IOP) as the average of 3 readings, the cup‑to‑disc ratio (CDR), the visual field changes, and the details of treatment received.Results: Eighty glaucomatous eyes from 50 patients were included in the study. The mean age was 54.8 ± 12.7 years, and the mean IOP was 19 ± 3.9 mmHg that ranged from 11 to 28 mmHg. The mean CDR mean was 0.48 ± 0.16 that ranged between 0.3 and 0.9. Ninety‑one percent of the visual field defects were arcuate scotomata. Primary open‑angle glaucoma (POAG) (60%) was the most predominant type of glaucoma, followed by primary angle closure glaucoma (ACG) (21.3%), secondary OAG (7.5%), and secondary ACG (6.3%). As for the anti‑glaucoma medications, 88% of the studied patients were on more than one medicine.Conclusion: This pilot study has demonstrated that POAG may be the predominant type of glaucoma in Al‑Ahsa, Kingdom of Saudi Arabia (KSA). Apopulation‑based study with a larger sample size is warranted to confirm the outcome and to provide a baseline data on the prevalence of types of glaucoma in this region of KSA.Keywords: Glaucoma, glaucoma types, prevalence, Saudi Arabi

Formulation, Optimization and Evaluation of Eudragit RL 100 nanoparticles loaded with Quercetin for its Hypolipidemic action by using Animal Model

Quercetin, a potent pharmacological active phytocompound, plays a crucial role in drug therapy. However, its essential role is limited due to poor water solubility and low bioavailability. To overcome these limitations and enhance oral bioavailability, Quercetin loaded Eudragit nanoparticles were prepared using a single emulsification solvent evaporation method and optimized by applying Box-Behnken design. This study aimed to investigate the anti-hyperlipidemic potential of Quercetin in Triton WR-1339 induced hyperlipidemic rats. Hyperlipidemia was induced in rats using Triton WR-1339, and the hypolipidemic potential of Quercetin was evaluated at doses of 50 and 100 mg/kg. The results revealed that Quercetin significantly (p ≤ 0.005) altered the serum levels of total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol, bringing them close to normal levels in Triton WR-1339 induced hyperlipidemic rats. Furthermore, both doses of Quercetin (50 and 100 mg/kg) showed significant reductions in TC and TG levels when compared to the standard atorvastatin treatment. The novel formulation of Quercetin loaded Eudragit polymeric nanoparticles displayed remarkable potential as a green antihyperlipidemic agent. These findings suggest that Quercetin loaded Eudragit nanoparticles can effectively mitigate hyperlipidemia and have the potential to be a promising therapeutic option for lipid disorders. The enhanced bioavailability and bioactivity of Quercetin delivered through this novel formulation open new possibilities for its clinical application in managing hyperlipidemia. Further research and clinical studies are warranted to explore its translational potential and wider applications in drug therap

Enhancing Physical Layer Secrecy Performance for RIS-assisted RF-FSO Mixed Wireless System

Peer reviewedPublisher PD

A Saudi Woman with Ceftriaxone Induced Fixed Drug Eruption

Background. A fixed drug eruption (FDE) is an immunological cutaneous adverse reaction, classified as a cutaneous adverse drug reaction (CADR) and characterized by well-defined lichenoid lesions that occur at the same site each time. Ceftriaxone is a third-generation antibiotic of cephalosporin antibiotics of the beta-lactam antibiotic family, which has typical in vitro activity against many Gram-negative aerobic bacteria. This is the first clinical case from Saudi Arabia and the fifth in the world to document a woman’s experience with recurrent FDE after repeated ceftriaxone use. Case Report. A 25-year-old Saudi woman with a known case of sickle cell anemia (SCA) with a history of avascular necrosis of the right hip after replacement was hospitalized with a pain crisis triggered by an upper respiratory tract infection. The patient denied having a history of allergy previously. Due to fever, leukocytosis, and active follicular tonsillitis, ceftriaxone was started. However, a few hours later she developed lip edema and a fixed drug eruption measuring 7 × 11 cm on the left side of her back. The lesion reformed over a hyperpigmented lesion (4 × 8 cm) that the patient did not report upon initial examination. It turned out that this was due to the intravenous administration of ceftriaxone, a year ago in another hospital. An allergy to ceftriaxone was considered, and steroids and antihistamines were started. The case was labeled as ceftriaxone induced FDE. Conclusion. Ceftriaxone induced FDE is an uncommon type of allergic reaction that has been reported infrequently. Understanding this condition and the mechanism by which FDE becomes recurrent with the same previous fixed lesion is of great importance for both academic and future research purposes

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.Keywords: Box-Behnken experimental design, Orally disintegrating tablets, Direct compression, Antidepressant, Magnesium stearate, Mixing tim