Stimulated generation of photobiogas by morphologically tuned nanostructured ZnO and ZnO/TiO2.

The photocatalytic degradation (PCD) of ethanol in an inert atmosphere on catalysis was explored in a lab-scale experiment. A morphologically tuned nanostructured controlled ZnO and ZnO/TiO2 nanocomposites were synthesized using a simple hydrothermal process under the control of several functionally capping agents marking a milestone in photocatalysis. It is possible that this could be modified to produce photobiogas out of organic dye pollution. The photocatalysts were characterized by the use of X-ray diffraction (XRD), transmission electron microscopy (TEM), Brunauer, Emmett, and Teller (BET) surface area analyzer, Scanning electron microscope (SEM-EDX), and UV-Vis absorption spectroscopy. The photocatalytic activity of the ZnO and ZnO-TiO2 composite nanostructures was evaluated for the photodegradation of the Tartrazine (Tr) dye aqueous solution. Where the composite matrix exhibits higher photocatalytic activity than pure ZnO nanomaterials as a result of the synergistic interaction between ZnO and TiO2 particles. This is mainly due to its higher surface area than pure ZnO. Moreover, the photocatalytic activity of the tuned nanostructured materials is found to be enhanced by the effect of the capping agent and controlling the morphology. This increase is accompanied by a significant shift in surface shape and band gap energy. According to the findings, the designed morphologies of pure ZnO photocatalyst impacted the formation of photobiogas from the photocatalytic decomposition of ethanol as a model of organic pollutants in wastewater. However, when using composite ZnO/TiO2 photocatalysts, the rate of CH4 formation is significantly lower than when using ZnO photocatalysts alone. This may be attributed to the synergetic effect between ZnO and TiO2 particles which leads to a remarkable reduction in the newly formed band gap energy. This may result in a fast rate of recombination between the photogenerated charge carriers (e- and h+).

COVID-19 deterministic and stochastic modelling with optimized daily vaccinations in Saudi Arabia.

In this paper, we investigate the stochastic nature of the COVID-19 temporal dynamics by generating a fractional-order dynamic model and a fractional-order-stochastic model. Initially, we considered the first and second vaccination doses as multiple vaccinations were initiated worldwide. The concerned models are then tested for the Saudi Arabia second virus wave, which is assumed to start on 1st March 2021. Four daily vaccination scenarios for the first and second dose are assumed for 100 days from the wave beginning. One of these scenarios is based on function optimization using the invasive weed optimization algorithm (IWO). After that, we numerically solve the established models using the fractional Euler method and the Euler-Murayama method. Finally, the obtained virus dynamics using the assumed scenarios and the real one started by the government are compared. The optimized scenario using the IWO effectively minimizes the predicted cumulative wave infections with a 4.4 % lower number of used vaccination doses.

Fractional stochastic models for COVID-19: Case study of Egypt.

In this paper, COVID-19 dynamics are modelled with three mathematical dynamic models, fractional order modified SEIRF model, stochastic modified SEIRF model, and fractional stochastic modified SEIRF model, to characterize and predict virus behavior. By using Euler method and Euler-Murayama method, the numerical solutions for the considered models are obtained. The considered models are applied to the case study of Egypt to forecast COVID-19 behavior for the second virus wave which is assumed to be started on 15 November 2020. Finally, comparisons between actual and predicted daily infections are presented.

Reproductive Pathological Changes Associated with Experimental Subchronic Corynebacterium pseudotuberculosis Infection in Nonpregnant Boer Does.

Corynebacterium pseudotuberculosis causes caseous lymphadenitis (CLA), which is a contagious and chronic disease in sheep and goats. In order to assess the histopathological changes observed in the reproductive organs of nonpregnant does infected with the bacteria, 20 apparently healthy adult Boer does were divided into four inoculation groups, intradermal, intranasal, oral, and control, consisting of five goats each. Excluding the control group, which was unexposed, other does were inoculated with 10(7) CFU/1 mL of live C. pseudotuberculosis through the various routes stated above. Thirty days after infection, the ovaries, uterus, and iliac lymph nodes were collected for bacterial recovery and molecular detection, as well as histopathological examination. The mean changes in necrosis, congestion, inflammatory cell infiltration, and oedema varied in severity among the ovaries, uterus, and iliac lymph nodes following different inoculation routes. Overall, the intranasal route of inoculation showed more severe (p < 0.05) lesions in all the organs examined. The findings of this study have shown that C. pseudotuberculosis could predispose to infertility resulting from pathological lesions in the uterus and ovaries of does.

Preclinical profile of bacopasides from Bacopa monnieri (BM) as an emerging class of therapeutics for management of chronic pains.

Chronic pains management costs billions of dollars in medical exchequer to the world population. Additionally, 77% of people with chronic pains also have a degree of medically treatable depression. Opioids have a narrower safety index due to their side effects associated with its tolerance, hyperalgesia and subsequent dependence. Likewise, non steroidal anti-inflammatory drugs and anticonvulsants, also have limited safety and tolerability profile in the management of chronic pains. Bacopa monnieri, a renowned ayurvedic medicine has a strong antidepressant effect and significant antinociceptive effect, which is comparable to the effect of morphine via adenosinergic, opioidergic, and adrenergic mechanisms. BM has been also reported to be effective in neuropathic pains. Additionally, it has a strong anti-inflammatory effect mediated via COX-2 inhibitory mechanism. Apart from its effect of augmenting morphine analgesia, BM also inhibits opioid-withdrawal induced hyperalgesia, and acquisition and expression of morphine tolerance. BM is reported to have a strong protective effect against toxic effects of opiates on major organs like brain, kidneys and heart. BM is well documented to be safe and well tolerated herbal therapy in multiple clinical trials including various age groups. This minireview evaluated the preclinical data that highlights potential of BM as a future candidate for clinical management of chronic pains.

Spectrofluorimetric assessment of doxycycline hydrochloride in pharmaceutical tablets and serum sample based on the enhancement of the luminescence intensity of the optical sensor Sm3+ ion.

A simple and sensitive spectrofluorimetric method for determination of trace amount of doxycycline hydrochloride (DC) in pharmaceutical tablets and serum samples was developed. In ammonia buffer solution of pH 8.9 the doxycycline hydrochloride can remarkably enhance the luminescence intensity of the Sm(3+) ion in Sm(3+)- DC complex at λ(ex)=400 nm. The produced luminescence intensity of Sm(3+)- DC complex in DMSO is in proportion to the concentration of DC and used as optical sensor for its determination. The dynamic range for the determination of DC is 1 × 10(-8)-5 × 10(-6) mol L(-1) and in case of quantum yield calculations is 7 × 10(-9)-5 × 10(-6) mol L(-1) with detection limit of 6.5 × 10(-10) mol L(-1). The enhancement mechanism of the luminescence intensity in the Sm(3+)- DC system has been also discussed. A comparison with other spectrofluorimetric methods for tetracycline derivatives in which Eu(3+) ion is used instead of Sm(3+) ion is also studied.

Spectrofluorimetric assessment of metoclopramide hydrochloride using terbium doped in PMMA matrix optical sensor.

A new, simple and accurate spectrofluorimetric method for the determination of metoclopramide hydrochloride was developed. The metoclopramide hydrochloride can remarkably enhance the luminescence intensity of the Tb(3+) ion doped in PMMA matrix at λ(ex)=360 nm in methanol at pH 6.9. The intensity of the emission band at 545 nm of Tb(3+) ion doped in PMMA matrix is increased due to the energy transfer from metoclopramide hydrochloride to Tb(3+) in the excited stated. The effect of different parameters, e.g., pH, temperature, Tb(3+) concentration, foreign ions that control the fluorescence intensity of the produced ion associate was critically investigated. The calibration curve of the emission intensity at 545 nm shows linear response of metoclopramide over a concentration range of 5 × 10(-5)-5.0 × 10(-8) M with detection limit of 8.7 × 10(-10) M. The method was used successfully for the determination of metoclopramide in pharmaceutical preparations and human serum. The average recovery of 99.48% with standard deviation of 0.32% and 96.98% with standard deviation of 0.4%, of pharmaceutical preparations and human serum respectively, were obtained which compared will with the results obtained from standard LC method of average recovery 99.04% and standard deviation of 0.6% and average recovery of 98.19% with standard deviation of 0.6% of pharmaceutical preparations and human serum, respectively.

Novel spectrofluorimetric method for measuring the activity of the enzyme alpha-L-fucosidase using the nano composite optical sensor samarium(III)-doxycycline complex doped in sol-gel matrix.

A novel, simple, sensitive, and precise spectrofluorimetric method was developed for measuring the activity of the enzyme alpha-L-fucosidase (AFU). The method was based upon measuring the quenching of the luminescence intensity of the produced yellow colored complex ion associate of 2-chloro-4-nitrophenol [2-CNP] and a nano composite optical sensor samarium(III)-doxycycline [Sm(3+)-DC](+) complex in a sol-gel matrix at 645 nm. The remarkable quenching of the luminescence intensity of the [Sm(3+)-DC](+) complex doped in a sol-gel matrix by various concentrations of the reagent [2-CNP] was successfully used as an optical sensor for the assessment of AFU activity. The calibration plot was achieved over the concentration range 3.4 x 10(-9)-1.0 x 10(-6) mol L(-1) [2-CNP] with a correlation coefficient of 0.99 and a detection limit of 6.0 x 10(-10) mol L(-1). The method was used satisfactorily for the assessment of the AFU activity in a number of serum samples collected from various patients. A significant correlation between the luminescence activity of the enzyme AFU measured by the proposed procedure and the standard method was applied to patients and controls. The method proceeds without practical artifacts compared to the standard method.

Spectrofluorimetric method for measuring the activity of the enzyme alpha-L-fucosidase using the ion associate of 2-chloro-4-nitro phenol-rhodamine-B.

A low cost and accurate method for the detection and analytical determination of the activity of the enzyme alpha-L-fucosidase (AFU) was developed. The method was based upon measuring the fluorescence intensity of the complex ion associate of the ion associate of rhodamine-B and the compound 2-chloro-4-nitrophenol (RB(+)CNP(-)) at 580 nm in phosphate buffer (pH 5) against the reagent blank. The influence of the different parameters, e.g. pH, incubation time, temperature, 2-chloro-4-nitrophenol concentration, foreign ions and surfactants that control the fluorescence intensity of the produced ion associate was critically investigated. The correlation between the fluorescence activity of the enzyme AFU by the developed procedures and the standard method was positive and highly significant in patients and controls (r(2)=0.99, p<0.001). The developed method is simple and proceeds without practical artifacts compared to the standard method.

A potentiometric rhodamine-B based membrane sensor for the selective determination of chromium ions in wastewater.

The construction and performance characteristics of a novel chromate ion-selective membrane sensor are described and used for determining chromium(III) and chromium(VI) ions. The sensor is based on the use of a rhodamine-B chromate ion-associate complex as an electroactive material in a poly(vinyl chloride) membrane plasticized with o-nitrophenyloctyl ether as a solvent mediator. In a phosphate buffer solution of pH 6 - 7, the sensor displays a stable, reproducible and linear potential response over the concentration range of 1 x 10(-1) - 5 x 10(-6) mol l(-1) with an anionic Nernstian slope of 30.8 +/- 0.5 mV decade(-1) and a detection limit of 1 x 10(-6) mol l(-1) Cr(VI). High selectivity for Cr(VI) is offered over many common anions (e.g., I-, Br-, Cl-, IO4-, CN-, acetate, oxalate, citrate, sulfate, phosphate, thiosulfate, selenite, nitrate) and cations (e.g., Ag+, Ca2+, Sr2+, Co2+, Ni2+, Cu2+, Mn2+, Fe2+, Zn2+, Cd2+, Al3+, Cr3+). The sensor is used for determining Cr(VI) and/or Cr(III) ions in separate or mixed solutions after the oxidation of Cr(III) into Cr(VI) with H2O2. As low as 0.2 microg ml(-1) of chromium is determined with a precision of +/-1.2%. The chromium contents of some wastewater samples were accurately assessed, and the results agreed fairly well with data obtained by atomic absorption spectrometry.

Potentiometric determination of dopamine in pharmaceutical preparations by crown ether-PVC membrane sensors.

Two simple, rapid and sensitive sensors for the assay of dopamine hydrochloride have been developed. The methods are based upon the formation of the membrane sensors 12-crown-4-phosphotungestic acid (crown ether-PTA)-dopamine and 12-crown-4-tetraphenylborate (crown ether-TPB)-dopamine as neutral carriers. The sensors were stable and showed fast potential responses of 10 s, and near-Nernstian cationic slopes of 53.3 - 56.2 mV/decade of activity between pH 2.2 - 6 for the monovalent dopamine cation over a wide range concentrations 1 x 10(-5) - 1 x 10(-1) M. The selectivity coefficients of the developed sensors indicated excellent selectivity for dopamine over a large number of organic and inorganic species and pharmaceutical excipients. The mediator o-nitrophenyloctyl ether significantly affected the lifetime of the fabricated sensors of dopamine. Satisfactory results were obtained for the determination of dopamine in dosage form by the proposed sensors with an average recovery of 99.85% for the nominal concentration.

Prevalence of blood-borne viral hepatitis in different communities in Yemen.

It is generally believed that hepatitis B (HBV) and C (HCV) viruses are highly prevalent in the Republic of Yemen. This study investigated the prevalence of HBV and HCV markers in 494 blood donors from Aden, 493 blood donors from Sana'a, 97 residents from an African ethnic minority in Sana'a and 99 residents of Soqotra Island. There were significant differences in the prevalence of HBV carriage (HBsAg: 6.7, 15, 19.6 and 26.3% respectively; P < 0.001); past HBV infection (anti-HBc: 17.4, 18.5, 30.9 and 59.6% respectively; P < 0.001); susceptibility to HBV (absence of HBV markers: 73.3, 61.9, 38.1 and 9.1% respectively; P < 0.001), infectivity of HBV carriers (HBV DNA: 51.5, 33.8, 52.6 and 65.4% respectively; P = 0.028) and HCV antibodies (RIBA confirmed or indeterminate: 0.6, 0.2, 5.2 and 5.1% respectively; P < 0.001). A significant difference in HBV carrier rate and a borderline significant difference in the prevalence of natural infection was observed between males and females in the African community (P = 0.02 and 0.06 respectively). In contrast, in Soqotra Island, there was no significant sex difference in HBV carrier rate but susceptibility was significantly more prevalent in males (P = 0.03). This study illustrates that significant difference in prevalence and epidemiology exists among different communities within the same country, reflecting political, geographical and social differences. Control strategies should take these differences into account.

Nutritional evaluation of some commercial baby foods consumed in Saudi Arabia.

The nutritive value of six baby foods based on milk (Nido, Wadi Fatima and Gain) and milk-cereal blends (Cerelac with wheat, Cerelac with rice and Milupa 2) commonly used in the Kingdom of Saudia Arabia was evaluated chemically including fatty acids analysis and biologically in growing rats. The milk based products vs milk-cereal blends provided (per 100 kcal) protein (3.8-5.0 g vs 3.7-3.8 g), fat (5.2-5.7 g vs 2.0-4.8 g), available carbohydrates (7.3-9.5 g vs 10.5-16.6 g), Ca (159-189 mg vs 101-145 mg), Mg (15-18 mg vs 14-20 mg), Na (32-39 mg vs 42-51 mg), K (160-180 mg vs 122-144 mg), Fe (1.4-1.8 mg vs 1.5-1.9 mg), Cu (0.04-0.09 mg vs 0.09-0.1 mg), Zn (0.8-1.2 mg vs 0.8-1.1 mg), and linoleic acid (208-1343 mg vs 518-639 mg). Metabolizable energy (ME) values in milk based products (487-495 kcal/100 g) were higher than milk-cereal blends (404-473 kcal/100 g). The true protein digestibility (TD) varied from (93-95%) in milk based foods to (94-95%) in milk-cereal blends. The net protein utilization (NPU) ranged between (0.74-0.78) in milk based products and (0.68-0.74) in milk-cereal blends. The net dietary protein calorie percent (NDP cal%) was higher in milk based foods (11.7-15.0%) than milk-cereal blends (10.2-11.1%). An imbalance of calories and nutrients in some baby foods was noticed. However, the protein quality was satisfactory and could meet the protein requirements of infants and toddlers as indicated by NDP cal% values.

Differential patterns of blastulation in bovine morulae cultured in synthetic oviduct fluid medium containing FCS or BSA.

This study examined the effects of fetal calf serum (FCS) supplementation of culture medium on blastulation and hatching of bovine morulae cultured in vitro. The presumptive zygotes derived from in vitro maturation and fertilization (IVM/IVF) were cultured in the modified synthetic oviduct fluid medium containing 3 mg/ml BSA (mSOF-BSA). At 120 h post insemination, morulae were randomly assigned to culture with mSOF-BSA (control) or mSOF containing 5% FCS (mSOF-FCS) instead of BSA. The replacement of BSA with FCS in mSOF significantly increased the percentage of blastocyst formation from Day 6 to Day 10 (Day 0 = the day of in vitro insemination) and the hatching rate of embryos on Days 8 and 9. The total number of cells in morulae and blastocysts on Day 6, in blastocysts on Day 7, and in blastocysts and hatched blastocysts on Day 8 were similar among the treatments. However, the replacement of BSA with FCS in mSOF significantly increased the total number of cells in hatched blastocysts on Day 10. Although the time of blastulation of embryos was significantly accelerated by the replacement of BSA with FCS in mSOF, the total number of cells in embryos at blastulation was lowered. The total number of cells in embryos at blastulation showed a time-dependent decrease when the embryos were cultured in mSOF-BSA. In contrast, the total number of cells in embryos that were cultured in mSOF-FCS depended little on the time after in vitro insemination. The results indicate that FCS supplementation of culture medium increased the percentage of embryos developing to the blastocyst stage without an increase in the total number of cells. However, an acceleration in the hatching rate and an increase in the total number of cells in hatched blastocysts were observed, compared with that in BSA-supplemented medium. It is suggested that FCS in the culture medium initiates earlier blastulation with fewer total numbers of cells in the morulae than BSA during in vitro culture of bovine embryos.

Chloroquine resistant malaria in West Malaysia.

Chloroquine resistance is a well established entity in South East Asia, and presents a problem of increasing importance. Strains of P. falciparum resistant to chloroquine have also been found to be resistant to amodiaquine and a combination of pyrimethamine and sulphadoxine. Knowledge of the drug sensitivity of the strains of malaria parasite in a given locality is important so that the right choice of drugs can be made in treatment of the disease. The treatment of chloroquine resistant malaria in West Malaysia is a subject of another paper but suffice it to say that increased doses of chloroquine have still been found to be effective in treating many cases of falciparum malaria from areas of chloroquine resistance.