Comparative evaluation of real-time PCR and ELISA for the detection of human fascioliasis.

Fascioliasis is a zoonotic parasitic infection caused by Fasciola species in humans and animals. Despite significant advances in vaccination and new therapeutic agents, little attention has been paid to validating methods for the diagnosis of fascioliasis in humans. Serological techniques are convenient assays that significantly improves the diagnosis of Fasciola infection. However, a more sensitive method is required. The aim of this study was to compare the Real-Time PCR technique with the indirect-ELISA for the detection of Fasciola hepatica in human. Using a panel of sera from patients infected with Fasciola hepatica (n = 51), other parasitic infections (n = 7), and uninfected controls (n = 12), we optimized an ELISA which employs an excretory-secretory antigens from F. hepatica for the detection of human fascioliasis. After DNA extraction from the samples, molecular analysis was done using Real-Time PCR technique based on the Fasciola ribosomal ITS1 sequence. Of 70 patient serum samples, 44 (62.86%) samples were identified as positive F. hepatica infection using ELISA and Real-Time PCR assays. There was no cross-reaction with other parasitic diseases such as toxoplasmosis, leishmaniasis, taeniasis, hydatidosis, trichinosis, toxocariasis, and strongyloidiasis. The significant difference between the agreement and similarity of the results of patients with indirect ELISA and Real-Time PCR was 94.4% and 99.2%, respectively (Cohen's kappa ≥ 0.7; P = 0.02). Based on the Kappa agreement findings, the significant agreement between the results of ELISA and Real-Time PCR indicates the accuracy and reliability of these tests in the diagnosis of F. hepatica in humans.

Correlation of vitamin D levels with serum parameters in Covid-19 patients.

BACKGROUND: It is well-established that vitamins have many beneficial roles and protect humans against inflammatory diseases. Vitamin D, a lipid-soluble vitamin, plays a crucial role in viral infections. Therefore, this study aimed to investigate if serum 25(OH)D levels affect morbidity, mortality, and levels of inflammatory parameters in COVID-19 patients. METHODS: 140 COVID-19 patients participated in this study (65 outpatients and 75 inpatients). Their blood samples were collected to determine TNFα, IL-6, D-dimer, zinc, Ca2+, and 25(OH)D levels. Patients with O2 saturation <93% were admitted and hospitalized in the infectious disease ward (inpatient group). Patients with O2 saturation >93% received routine treatment and were discharged (Outpatient group). RESULTS: The serum levels of 25(OH)D in the inpatient group were significantly lower than those in the outpatient group (p < 0.001). Serum TNF-α, IL-6, and D-dimer levels in the inpatient group were significantly higher than those in the outpatient group (p < 0.001). Serum TNF-α, IL-6, and D-dimer levels were inversely correlated with 25(OH)D levels. No significant differences were observed in the serum levels of zinc and Ca2+ between the studied groups (p = 0.96, p = 0.41 respectively). Ten out of 75 patients in the inpatient group were admitted to ICU (intubated). Nine out of them lost their lives (the mortality rate in ICU-admitted patients was 90%). CONCLUSIONS: The lower mortality and severity of COVID-19 patients with higher 25(OH)D levels represented that this vitamin alleviates the severity of COVID-19.

Fabrication of CuWO4/Bi2S3/ZIF67 MOF: A novel double Z-scheme ternary heterostructure for boosting visible-light photodegradation of antibiotics.

A novel double Z-scheme CuWO4/Bi2S3/ZIF67 ternary heterostructure was synthesized through hydrothermal method. The catalysts were characterized by XRD, FTIR, SEM, EDX, BET, TEM, PL, and UV-vis DRS analyses. The degradations of Metronidazole (MTZ) and Cephalexin (CFX) antibiotics by ternary catalyst were investigated in the batch and continuous slurry photoreactor under LED illumination. The ternary heterostructure exhibited a remarkable improvement in photoactivity compared with CuWO4/Bi2S3, and pristine ZIF67. Indeed, higher surface area, photo-stability, bandgap suppressing as well as better charge separation based on the dual Z-scheme structure caused the enhancement. The optimum values of operating parameters were obtained by the central composite design as: catalyst dose = 0.3 g/L, pH = 7, illumination time = 80 min, and 20 ppm initial concentration of antibiotic. The maximum degradation efficiencies by the new ternary heterostructure were 95.6% and 90.1%, respectively for MTZ and CFX at optimum conditions in the continuous flow mode. Maximum total organic carbon (TOC) removal rates were 83.2% and 74% for MTZ and CFX, respectively. The degradations by ternary composite followed the first-order kinetic, by reaction rate of 9 times, 5.5 times, and 4 times higher than that obtained by Bi2S3, ZIF67, and the binary CuWO4/Bi2S3, respectively. The influences of temperature and light intensity were explored, revealing 25 °C and 400 W/m2 as the optimum values. The new ternary heterostructure demonstrated excellent reusability and chemical stability after six cycles. The dominant active species were explored by trapping tests, indicating OH. free radicals as the most primary oxidant.

Novel approaches to immobilize Candida rugosa lipase on nanocomposite membranes prepared by covalent attachment of magnetic nanoparticles on poly acrylonitrile membrane.

Novel methods have been developed for lipase immobilization on poly acrylonitrile (PAN) membranes to increase the activity and stability of the immobilized lipase. In this study, poly acrylonitrile (PAN) membranes were aminated and then activated by glutaraldehyde or epichlorohydrine to be used for enzyme immobilization. In the other approach, magnetic nanoparticles (MNPs) which were functionalized with trichlorotriazine (TCT) or glutaraldehyde (GA) were attached to the membrane surface to prepare the nanocomposite membranes named TCT-MNP@PAN & GA-MNP@PAN membranes. Candida rugosa lipase (CRL) was covalently immobilized on this activated nanocomposite membrane. Nanoparticles and nanocomposite membranes were characterized with various techniques such as SEM, TEM, XRD, FTIR, FTIR-ATR, AFM, contact angle goniometry and surface free energy measurement. The evidence of immobilization was also done by FTIR-ATR, enzyme activity, and loading efficiency. It was found that the activity of immobilized lipase on GA and TCT functionalized NCPAN membrane were about 50% and 31% higher than that immobilized on GA-activated PAN membrane. The kinetic parameters of enzymatic membranes showed the better conformation of the lipase enzyme immobilized on the TCT-MNP@PAN membrane. The presented enzymatic nanocomposite membranes are easy to prepare with low cost and are good candidates for use in membrane bioreactors.

Kinetics of substrate utilization and bacterial growth of crude oil degraded by Pseudomonas aeruginosa.

Pollution associated with crude oil (CO) extraction degrades the quality of waters, threatens drinking water sources and may ham air quality. The systems biology approach aims at learning the kinetics of substrate utilization and bacterial growth for a biological process for which very limited knowledge is available. This study uses the Pseudomonas aeruginosa to degrade CO and determines the kinetic parameters of substrate utilization and bacterial growth modeled from a completely mixed batch reactor. The ability of Pseudomonas aeruginosa can remove 91 % of the total petroleum hydrocarbons and 83 % of the aromatic compounds from oily environment. The value k of 9.31 g of substrate g(-1) of microorganism d(-1) could be far higher than the value k obtained for petrochemical wastewater treatment and that for municipal wastewater treatment. The production of new cells of using CO as the sole carbon and energy source can exceed 2(3) of the existing cells per day. The kinetic parameters are verified to contribute to improving the biological removal of CO from oily environment.