SARS-CoV-2 outbreak: role of viral proteins and genomic diversity in virus infection and COVID-19 progression.

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection is the cause of coronavirus disease 2019 (COVID-19); a severe respiratory distress that has emerged from the city of Wuhan, Hubei province, China during December 2019. COVID-19 is currently the major global health problem and the disease has now spread to most countries in the world. COVID-19 has profoundly impacted human health and activities worldwide. Genetic mutation is one of the essential characteristics of viruses. They do so to adapt to their host or to move to another one. Viral genetic mutations have a high potentiality to impact human health as these mutations grant viruses unique unpredicted characteristics. The difficulty in predicting viral genetic mutations is a significant obstacle in the field. Evidence indicates that SARS-CoV-2 has a variety of genetic mutations and genomic diversity with obvious clinical consequences and implications. In this review, we comprehensively summarized and discussed the currently available knowledge regarding SARS-CoV-2 outbreaks with a fundamental focus on the role of the viral proteins and their mutations in viral infection and COVID-19 progression. We also summarized the clinical implications of SARS-CoV-2 variants and how they affect the disease severity and hinder vaccine development. Finally, we provided a massive phylogenetic analysis of the spike gene of 214 SARS-CoV-2 isolates from different geographical regions all over the world and their associated clinical implications.

Hyaluronan: Sources, Structure, Features and Applications.

Hyaluronan (HA) is a non-sulfated glycosaminoglycan that is present in a variety of body tissues and organs. Hyaluronan has a wide range of biological activities that are frequently influenced by molar mass; however, they also depend greatly on the source, purity, and kind of impurities in hyaluronan. High-molar-mass HA has anti-inflammatory, immunosuppressive, and antiangiogenic properties, while low-molar-mass HA has opposite properties. A number of chemical modifications have been performed to enhance the stability of HA and its applications in medical practice. Hyaluronan is widely applied in medicine, such as viscosupplementation, ophthalmology, otolaryngology, wound healing, cosmetics, and drug delivery. In this review, we summarized several medical applications of polymers based on the hyaluronan backbone.

Covalent immobilization of ß-galactosidase using a novel carrier alginate/tea waste: statistical optimization of beads modification and reusability.

ß-galactosidase has been immobilized onto novel alginate/tea waste gel beads (Alg/TW) via covalent binding. Alg/TW beads were subjected to chemical modification through amination with polyethyleneimine (PEI) followed by activation with glutaraldehyde (GA). Chemical modification parameters including PEI concentration, PEI pH, and GA concentration were statistically optimized using Response Surface methodology (RSM) based on Box-Behnken Design (BBD). Analysis of variance (ANOVA) results confirmed the great significance of the model that had F value of 37.26 and P value < 0.05. Furthermore, the R2 value (0.9882), Adjusted R2 value (0.9617), and predicted R2 value (0.8130) referred to the high correlation between predicted and experimental values, demonstrating the fitness of the model. In addition, the coefficient of variation (CV) value was 2.90 that pointed to the accuracy of the experiments. The highest immobilization yield (IY) of ß-galactosidase (75.1%) was given under optimized conditions of PEI concentration (4%), PEI pH (9.5), and GA concentration (2.5%). Alg/TW beads were characterized by FT-IR, TGA, and SEM techniques at each step of immobilization process. Moreover, the immobilized ß-galactosidase revealed a very good reusability as it could be reused for 15 and 20 consecutive cycles keeping 99.7 and 72.1% of its initial activity, respectively. In conclusion, the environmental waste (tea waste) can be used in modern technological industries such as the food and pharmaceutical industry.

Protease immobilization on a novel activated carrier alginate/dextrose beads: Improved stability and catalytic activity via covalent binding.

Protease from Bacillus thuringiensis strain-MA8 was successfully immobilized onto activated Alginate/dextrose (Alg/dex) beads as a new carrier with immobilization yield 77.6 %. The carrier was characterized using Scanning electron microscopy and Fourier transforms infrared spectrophotometer at every step of the immobilization process. Immobilized protease showed an increase of 10 °C in the optimum temperature compared to the free enzyme. However, the optimum pH for both the free and the Alg/dex/protease was found to be 8. The lower activation energy and deactivation rate constant and the higher half-life time and D-value confirm that the new Alg/dex carrier is suitable for promoting enzyme stability. The raise in thermal stability is also shown by the increased deactivation energy of the Alg/dex/protease compared to its free form by 1.47-fold. Likewise, the enzyme immobilization enhancement of Alg/dex/protease was accompanied by a marked increase in enthalpy and Gibbs free energy. The negative entropy for both free and Alg/dex/protease indicates that the enzyme is more stable in thermal deactivation. The Km and Vmax for the Alg/dex/protease were 2.05 and 1.22-times greater than the free form. Furthermore, Alg/dex/protease displayed good reusability as it retained 92.7 and 52.4 % of its activity after 8 and 12 hydrolysis cycles.

Carbohydrate microcapsules tailored and grafted for covalent immobilization of glucose isomerase for pharmaceutical and food industries.

Carrageenan is one of the most common carbohydrates utilised in the entrapment industry to immobilise cells and enzymes. However, it lacks functionality. Carrageenan has been grafted to produce fructose by covalently immobilising glucose isomerase (GI). Fructose is one of the most widely used sweeteners in beverages, food production, and the pharmaceutical business. Up to 91.1 U g-1 gel beads are immobilised by the grafted beads. Immobilized GI has a Vmax of 13.8 times that of the free enzyme. pH of immobilized GI was improved from 6.5-7 to 6-7.5 that means more stability in wide pH range. Also, optimum temperature was improved and become 65-75 °C while it was at 70 °C for free enzyme. The immovability and tolerance of the gel beads immobilised with GI over 15 consecutive cycles were demonstrated in a reusability test, with 88 percent of the enzyme's original activity retained, compared to 60 percent by other authors. These findings are encouraging for high-fructose corn syrup producers.

Handwashing Knowledge, Attitudes, and Practices among Students in Eastern Province Schools, Saudi Arabia.

Background. Lack of knowledge about appropriate handwashing practices has caused great concerns for human health, especially in the risk of many communicable diseases. The objective of the current study is to determine the level of handwashing knowledge, attitudes, and practices among school students in Eastern Province Schools, Saudi Arabia. A cross-sectional survey was recruited from November 2019 to March 2020 to assess the level of the students' handwashing knowledge. A reliable questionnaire was prepared (Cronbach's alpha = 0.608) and conducted using a two-stage sampling technique. A total of 271 students participated in the study from primary, middle, and high schools; 80% were boys, most of whom displayed an acceptable level of knowledge on hand hygiene. Nearly 75% and 74% of boys and girls, respectively, gained knowledge about hand hygiene practices from their parents. Only 46% of the students thought that handwashing is a potential protective measure against diseases, whereas 34% thought it only removes dirt. Prevalence of handwashing with soap after using the toilet was recognized among 52% of the students. Additionally, 93% of the students used water and soap to wash their hands (p value < 0.001) and 97% suggested that soap and water are the best methods to wash their hands (p value < 0.001). There was a positive correlation between the mother's education and hand hygiene practices (p value = 0.044). Results collectively indicated that handwashing knowledge and practices among school students in the Eastern Province are acceptable interventions in preventing the transmission of infectious diseases such as COVID-19. Indeed, further improvement conducted through specific health education programs to emphasize the role of handwashing in health hygiene is highly recommended.

Corrigendum to "Catalytic, kinetic and thermal properties of free andimmobilized Bacillus subtilis -MK1 α-amylase on Chitosan-magnetic nanoparticles" [Biotechnol. Rep. 26 (2020) e00443].

[This corrects the article DOI: 10.1016/j.btre.2020.e00443.].

Modified Pectoral Nerve Block versus Serratus Block for Analgesia Following Modified Radical Mastectomy: A Randomized Controlled Trial.

BACKGROUND: Modified pectoral nerves (PECSII) and serratus blocks have been recently used for analgesia in breast surgery, but evidence comparing their analgesic benefits is limited. This prospective randomized, controlled study aims to examine the analgesic efficacy and safety profile of ultrasound-guided PECSII versus serratus blocks in patients undergoing modified radical mastectomy (MRM) for breast cancer. PATIENTS AND METHODS: One-hundred and eighty adult females scheduled for MRM were randomly allocated to three groups. PECS group patients received a PECSII block with 30mL of bupivacaine 0.25%, whereas SAPB group received a serratus anterior plane block (SAPB) using the same volume of bupivacaine 0.25% before induction of anesthesia. The control group received general anesthesia alone. Outcomes included 24 hours morphine consumption, intraoperative fentanyl requirements, visual analogue scale (VAS) scores for pain at rest and during movement, time to first rescue analgesia, postoperative nausea and vomiting (PONV), and sedation scores. RESULTS: Both PECSII and serratus blocks were associated with reduced postoperative morphine consumption compared to the control group (p<0.001). Both blocks were associated with reduced intraoperative fentanyl requirements, VAS scores, and PONV as compared with the control group. Also, they were associated with prolonged time to first rescue analgesia and better sedation scores in comparison with the control group. However, there were no differences between both blocks for all outcomes. CONCLUSION: PECSII and serratus blocks provide similarly adequate analgesia following modified radical mastectomy. CLINICAL TRIAL REGISTRATION: NCT02946294.

Synthesis and characterization of a novel rice bran protein-cerium complex for the removal of organophosphorus pesticide residues from wastewater.

The removal of organophosphorus pesticides residues from wastewater of fruits and vegetables processing as well as other agricultural processes by a low-cost, environment-friendly, and efficient strategy is necessary. In this study, rice bran protein (RBP) was cross-linked with ceric ammonium nitrate (CAN). The results showed that the cross-linking process generated new functional groups and significantly enhanced the chemical reactivity and adsorption capacity of RBP. The RBPC showed rough and porous surface structure compared with smooth surface structure for RBP. In addition, greatest adsorption capacity of 193.0 mg/g and omethoate removal efficiency of 72.1% was achieved, and the results fitted well with Langmuir isotherm and pseudo-second order models. Moreover, Omethoate (5 mg/L) removal efficiency maintained over 60% after 5 cycles of RBPC usage. Therefore, the obtained RBPC complex can be suggested as an efficient adsorbent for the removal of pesticide residues from wastewater.

Catalytic, kinetic and thermal properties of free andimmobilized Bacillus subtilis -MK1 α-amylase on Chitosan-magnetic nanoparticles.

Bacillus subtilis strain-MK1 α-amylase was successfully immobilized on Chitosan-magnetic nanoparticles (Ch-MNP) that had been modified with polyethyleneimine (PEI) and glutaraldehyde (GA). Optimization of Ch-MNP/PEI/GA beads modification by Central Composite design enhanced the immobilization yield (IY %) by 1.5-fold. Ch-MNP/PEI/GA was characterized before and after modification and immobilization by FTIR and SEM. Ch-MNP/PEI/GA/Enzyme showed the same pH optima of free enzyme, while an elevation 10 °C in temperature optima was observed after its immobilization. Ch-MNP/PEI/GA/Enzyme displayed higher Km and Vmax values (2.1 and 1.2-fold) and lower Vmax/Km ratio (1.7-fold), respectively than the free enzyme. Compared to the free enzyme, Ch-MNP/PEI/GA/Enzyme exhibited lower activation energy, lower deactivation constant rate, higher D-values, higher half-life, and higher energy for denaturation. Immobilization of α-amylase increased enthalpy (4.2-fold), free energy (1.1-fold) and decreased entropy (4.6-fold) of thermal inactivation. A significant increase in pH stability of Ch-MNP/PEI/GA/Enzyme was observed especially at alkaline pH values. In addition, Ch-MNP/PEI/GA/Enzyme preserved 83.2 % of its initial activity after 15 consecutive cycles. When storing Ch-MNP/PEI/GA/Enzyme at 4 °C the residual activity was 100 and 86 %, respectively after 21 and 40 days. Finally, immobilization process improved the catalytic properties and stabilities, thus raising the suitability for industrial processes with lower cost and time.

Impact of immobilization technology in industrial and pharmaceutical applications.

The current demands of the world's biotechnological industries are enhancement in enzyme productivity and development of novel techniques for increasing their shelf life. Compared to free enzymes in solution, immobilized enzymes are more robust and more resistant to environmental changes. More importantly, the heterogeneity of the immobilized enzyme systems allows an easy recovery of both enzymes and products, multiple reuse of enzymes, continuous operation of enzymatic processes, rapid termination of reactions, and greater variety of bioreactor designs. This review summarizes immobilization definition, different immobilization methods, advantages and disadvantages of each method. In addition, it covers some food industries, protein purification, human nutrition, biodiesel production, and textile industry. In these industries, the use of enzymes has become an inevitable processing strategy when a perfect end product is desired. It also can be used in many other important industries including health care and pharmaceuticals applications. One of the best uses of enzymes in the modern life is their application in diagnose and treatment of many disease especially when used in drug delivery system or when used in nanoform.

Immobilization of xylanase on modified grafted alginate polyethyleneimine bead based on impact of sodium cation effect.

Alginate- polyethyleneimine gel beads modified by using 0.3 M Na+ were used for covalent immobilization of Aspergillus flavus xylanase. SEM images showed distorted structure with addition of Na+ that impaired the egg-box structure formation offered much covalent binding with xylanase. Immobilization onto (Alg+PEI/Na+) showed an enhancement in the operational stability, immobilization efficiency as well as immobilization yield. Covalent immobilization of xylanase onto (Alg+PEI/Na+) enhanced xylanase activity over a wide range of pHs (4-5.5) comparable to its free formula. As well as an increase in reaction temperature up to 60°C. However, immobilized formula of enzyme showed abroad thermal stability that it retained 79.0% of its initial activity at 70°C up to 30 min whereas, free formula completely lost its activity at this temperature. Thermodynamics studies showed an enhancement in thermal stability at high temperature for the immobilized xylanase. i.e. At 70°C the t1/2 and D-value for free formula of enzyme increased from 24 to165 min and from 79.95to 548.23 min, respectively. Moreover, the enzyme stability enhancement for immobilized formula of xylanase was proved with a remarkable increase in enthalpy and free energy. 93% of the immobilized xylanase activity was retained over 6 weeks of storage at -4°C.

Health Benefits of Fennel, Rosemary Volatile Oils and their Nano-Forms in Dyslipidemic Rat Model.

BACKGROUND AND OBJECTIVE: Dyslipidemia is a major health problem that may lead to cardiovascular diseases (CVDs). In the present research, a biological experiment was run on dyslipidemic rats to study the health benefits of the volatile oils (VOs) of fennel and rosemary in its original and nano-form using chitosan as carrier. MATERIALS AND METHODS: Rats were divided into 6 groups; normal control, dyslipidemic control and 4 test groups with dyslipidemia and treated by VOs of fennel and rosemary and their respective nano-forms separately. Glucose tolerance test was carried out after 4 weeks. Parameters reflecting oxidative stress/antioxidant plasma catalase, malondialdehyde (MDA) and blood uric acid, were assessed. Plasma lipid profile and tumor necrosis factor alpha (TNF-α) as inflammatory biomarker were determined. Liver and kidney function were assessed as determinant of the safety of the different VO forms. Twenty four hour urinary volume was measured to assess creatinine clearance and to evaluate the possible diuretic activity of the VOs. RESULTS: Dyslipidemic control rats showed dyslipidemia, increased CVDs risk, liver dysfunction, elevated MDA and TNF-α with marked increase in blood sugar after half an hour of glucose ingestion compared to normal control. Treatment with the four VOs forms improved the majority of the biochemical parameters. CONCLUSION: All treatment showed cardio and hepato- protective effect and safety towards kidney and blood sugar. Oxidative stress and inflammatory biomarkers were significantly improved by the different treatments; both VO forms of fennel were more efficient in ameliorating inflammation.

Optimization of pectinase immobilization on grafted alginate-agar gel beads by 24 full factorial CCD and thermodynamic profiling for evaluating of operational covalent immobilization.

Pectinase produced by a honey derived from the fungus Aspergillus awamori KX943614 was covalently immobilized onto gel beads made of alginate and agar. Polyethyleneimine, glutaraldehyde, loading time and enzyme's units were optimized by 24 full factorial central composite design (CCD). The immobilization process increased the optimal working pH for the free pectinase from 5 to a broader range of pH4.5-5.5 and the optimum operational temperature from 55°C to a higher temperature, of 60°C, which is favored to reduce the enzyme's microbial contamination. The thermodynamics studies showed a thermal stability enhancement against high temperature for the immobilized formula. Moreover, an increase in half-lives and D-values was achieved. The thermodynamic studies proved that immobilization of pectinase made a remarkable increase in enthalpy and free energy because of enzyme stability enhancement. The reusability test revealed that 60% of pectinase's original activity was retained after 8 successive cycles. This gel formula may be convenient for immobilization of other industrial enzymes.

Production, immobilization and thermodynamic studies of free and immobilized Aspergillus awamori amylase.

Enzyme cost, stability and its thermodynamic characteristics are the main criteria for industrial use. In this study, Aspergillus awamori amylase was constitutively produced using various agro-industrial wastes. Olive oil cake gave the highest activity (230U/g). The amylase was partially purified to 2.81-fold purification. Immobilization was achieved using different carriers by covalent binding. The novel carrier Ca+2 alginate (Alg) starch (St)/polyethyleneimine (PEI)/glutaraldehyde (GA), showed the highest operational stability and was selected for further studies. The optimum temperature for the free and immobilized form was 50°C and 55-60°C, respectively. The immobilization process had a major role in improving enzyme thermal stability. In comparison to free enzyme, the immobilized form showed the highest optimum temperature, activation energy (Ea) and deactivation rate constants (kd). Also, t1/2, D-values (decimal reduction time), change in enthalpy (ΔH° kJmol-1), and Gibbs free energy (ΔG°) increased and was higher than the native enzyme within 50-80°C. The magnitude of negative value of entropy (ΔS° kJmol-1) for immobilized enzyme was negative for the free and immobilized enzymes revealing that native form of enzyme was in more ordered state. Km and Vmax values were slightly affected by the temperature variations 40-70°C.

Enzymatic synthesis using immobilized Enterococcus faecalis Esawy dextransucrase and some applied studies.

Dextrans enzymatic synthesis by immobilized Enterococcus faecalis Esawy dextransucrase was studied. Different parameters, such as: enzyme protein concentration (EPC), substrate concentration (SC), temperature and reaction time were evaluated. EPC played a fundamental role in controlling dextran molecular size with 0.1% dextran in reaction mixture. Dextran 38,397 and 125,471Da were yielded at EPC 4.78 and 5.78mg, respectively. Proper dextrans (73,378 and 117,521Da) demanded in pharmaceutical applications were achieved at 6% and 12% sucrose concentrations and at 4.78 and 5.78mg EPC, respectively. Optimum temperature for conversion of glucose to dextran was 30°C (73% and 80% at 5.78 and 4.78mg EPC, respectively). Varieties of maltooligosaccharides (MOS) were yielded by synergistic cooperation between sucrose and maltose. Six MOS and three dextrans samples in vitro have prebiotic effect on Lactobacillus casei with degree of variation. Two samples of MOS with different degree of polymerization (DP) and three samples of dextran with different molecular weight (MW) reported different fibrinolytic activity.

Covalent immobilization of microbial naringinase using novel thermally stable biopolymer for hydrolysis of naringin.

Naringinase induced from the fermented broth of marine-derived fungus Aspergillus niger was immobilized into grafted gel beads, to obtain biocatalytically active beads. The support for enzyme immobilization was characterized by ART-FTIR and TGA techniques. TGA revealed a significant improvement in the grafted gel's thermal stability from 200 to 300 °C. Optimization of the enzyme loading capacity increased gradually by 28-fold from 32 U/g gel to 899 U/g gel beads, retaining 99 % of the enzyme immobilization efficiency and 88 % of the immobilization yield. The immobilization process highly improved the enzyme's thermal stability from 50 to 70 °C, which is favored in food industries, and reusability test retained 100 % of the immobilized enzyme activity after 20 cycles. These results are very useful on the marketing and industrial levels.

Covalent immobilization of Enterococcus faecalis Esawy dextransucrase and dextran synthesis.

Enterococcus faecalis Esawy dextransucrase was immobilized in Fe(3+)-cross-linked alginate/carboxymethyl cellulose (AC) beads. The gel beads were modified with polyethylenimine (PEI) followed by glutaraldehyde (GA) to form Fe(3+) (ACPG) beads. Fe(3+) (ACPG) was characterized using FTIR and DSC techniques. GA activated beads showed new two peaks. The first was at 1,717 cm(-1) which refers to (CO) group of a free aldehyde end of glutaraldehyde, and another peak was at 1,660 cm(-1) referring to (CN) group. The immobilization process improved the optimum temperature from 35 to 45°C. The immobilized enzyme showed its optimum activity in wide pH range (4.5-5.4) compared to pH 5.4 in case of free form. Also, the immobilization process improved the thermal and pH enzyme stability to great extent. Reusability test proved that the enzyme activity retained 60% after 15 batch reactions. Immobilized enzyme was applied successfully in the synthesis of oligosaccharides and different molecular weights of dextran.

Novel grafted agar disks for the covalent immobilization of ß-D-galactosidase.

Novel grafted agar disks were prepared for the covalent immobilization of ß-D-galactosidase (ß-gal). The agar disks were activated through reacting with ethylenediamine or different molecular weights of Polyethyleneimine (PEI), followed by glutaraldehyde (GA). The modification of the agar gel and the binding of the enzyme were verified by Fourier Transform Infrared (FTIR) and elemental analysis. Moreover, the agar's activation process was optimized, and the amount of immobilized enzyme increased 3.44 folds, from 38.1 to 131.2 U/g gel, during the course of the optimization process. The immobilization of ß-gal onto the activated agar disks caused its optimum temperature to increase from 45°C to 45-55°C. The optimum pH of the enzyme was also shifted towards the acidic side (3.6-4.6) after its immobilization. Additionally, the Michaelis-Menten constant (Km ) increased for the immobilized ß-gal as compared to its free counterpart whereas the maximum reaction rate (Vmax ) decreased. The immobilized enzyme was also shown to retain 92.99% of its initial activity after being used for 15 consecutive times.

Unilateral versus bilateral wrap crural fixation in laparoscopic Nissen fundoplication for children.

INTRODUCTION: Gastroesophageal reflux (GERD) is common in neurologically impaired (NI) children. Fundoplication and gastrostomy have previously been indicated in NI children with GERD who have not responded to medical treatment. The most common reason for fundoplication failure is intrathoracic migration of the wrap. OBJECTIVE: The aim of the study is to measure the effect of wrap fixation on the final outcome of laparoscopic Nissen fundoplication in NI children. PATIENTS AND METHODS: A retrospective file review was conducted for all NI children who underwent laparoscopic Nissen fundoplication in 2 tertiary pediatric surgery centers in the United Arab Emirates from February 15, 2006 to February 15, 2013. Redo fundoplication patients were excluded from the study. Patients were divided into 2 groups: group 1 in which the fundoplication wrap was fixed to the right crus only, and group 2 in which the wrap was fixed to the right and left crus simultaneously. RESULTS: The study population included 68 patients; there were 47 male and 21 female children. Mean age at time of surgery was 8.2 years. Recurrent GERD at 1 year postoperatively was 26% versus 7% in group 1 and group 2, respectively, by upper contrast study. Redo surgery was required in 21% versus 3% in group 1 and group 2, respectively. CONCLUSIONS: Bilateral fixation of the wrap to diaphragmatic crura significantly reduced recurrent GERD, in laparoscopic Nissen fundoplication for neurologically impaired children, with no increased risk of morbidities. Future prospective studies should be conducted with larger patient populations and longer follow-up periods.