Investigation of the nanocrytalline SnO2 Synthesized by Homogeneous Precipitation

Nanocrystalline tin dioxide synthesized by the homogeneous pre cipitation method using the reaction of tin tetrachloride pentahydrate and urea solutions has been investigated. The nanocrystalline powder has been traced at different calcination temperatures (300ºC-1050ºC), and then characterized by using   Thermogravemetric analysis, differential thermal analysis and x-ray diffraction. The microstructure of the obtained nanoparticles has been examined by scanning and transmission electron microscopy. The average crystallite size, determined by x-ray diffraction, was found to be in the range of 3 –30 nm. The analysis exhibited a tetragonal phase.  Optical properties were investigated by a UV–vis absorption spectrophotometer. The calculated optical band gap lies between 4.47–3.71 eV as a result of increasing the calcination temperatures and crystallite size. Surface area and porosity of SnO2 nanoparticles are measured. Specific surface area which is related to pore volume and decreases from 155 m2/g at 100ºC to 3.3 m2/g at 1050ºC.Â

Toxico-histological Effects of Sublethal Concentrations of Lead Nitrate on the Gills of the African Catfish, Clarias gariepinus

170-175This study aimed to investigate the effects of subleathal lead doses on the histological architecture of gills in the freshwater African catfish, Clarias gariepinus. Results revealed three stages of changes after exposure to three doses of lead nitrate. The changes were mild in fish exposed to 16.12 mg/L of Pb (NO3)2 (stage I 20% of LC50) and severe in case of 40% of LC50 (stage II, 32.24 mg/L) and 60% of LC50 (stage III 48.37% mg/L) in comparison to control. The histological examination revealed normal architecture of gills in control fish. Normal gills were characterized with primary gill lamellae with a central hyaline cartilage. However, three-stage changes were observed after exposure to the three doses of lead nitrate. In stage I, a cartilaginous matrix appeared along with loosening of the epithelial lining of the cartilaginous core and abundant vascular spaces were observed on the secondary gill lamellae. An extra cartilaginous matrix, loosening of the epithelial lining of the cartilaginous core, de-shaped gill lamellae, and degeneration of the secondary gill lamellae were noted in stage II. Lesions in the gill pattern in stage III were represented by shortening of the tips of secondary gill lamellae, damaged gill lamellae, a cartilaginous matrix, and hyperplasia. This indicated that lead exposure resulted in severe histopathological changes in the gills in a dose-dependent manner

Characterization and optimization of lipase activity produced by Pseudomonas monteilli 2403-KY120354 isolated from ground beef

A total of 56 Gram negative bacterial isolates were recovered from twenty ground beef samples and were screened for their potentiality to produce lipase. Forty four bacterial isolates were recorded as positive producers for lipase on tween as carbon source in solid medium. Also, the highly producer isolates were screened for lipase activity in submerged culture using olive oil as carbon and the most active isolate was 2043 which gave an activity of 20.0 ± 0.29 U/ml. The bacterial isolate 2403 was identified phenotypically according to Bergey’s Manual and genotypically using 16S rRNA genes analysis as Pseudomonas monteilli. Effect of some different factors on lipase activity were studied and the maximum lipase activity was achieved at reaction medium of pH 6 and incubated at 40°C for 60 min. Also, addition of Ba2+ in the reaction medium enhanced the lipase activity, while the other tested metals reduced the enzyme activity.Key words: Food contamination, lipase activity, olive oil, cultural conditions, Pseudomonas

Toxico-histological Effects of Sublethal Concentrations of Lead Nitrate on the Gills of the African Catfish, Clarias gariepinus

This study aimed to investigate the effects of subleathal lead doses on the histological architecture of gills in the freshwater African catfish, Clarias gariepinus. Results revealed three stages of changes after exposure to three doses of lead nitrate. The changes were mild in fish exposed to 16.12 mg/L of Pb (NO3)2 (stage I 20% of LC50) and severe in case of 40% of LC50 (stage II, 32.24 mg/L) and 60% of LC50 (stage III 48.37% mg/L) in comparison to control. The histological examination revealed normal architecture of gills in control fish. Normal gills were characterized with primary gill lamellae with a central hyaline cartilage. However, three-stage changes were observed after exposure to the three doses of lead nitrate. In stage I, a cartilaginous matrix appeared along with loosening of the epithelial lining of the cartilaginous core and abundant vascular spaces were observed on the secondary gill lamellae. An extra cartilaginous matrix, loosening of the epithelial lining of the cartilaginous core, de-shaped gill lamellae, and degeneration of the secondary gill lamellae were noted in stage II. Lesions in the gill pattern in stage III were represented by shortening of the tips of secondary gill lamellae, damaged gill lamellae, a cartilaginous matrix, and hyperplasia. This indicated that lead exposure resulted in severe histopathological changes in the gills in a dose-dependent manner

Osteogenic Differentiation Potential of Human Bone Marrow and Amniotic Fluid-Derived Mesenchymal Stem Cells in Vitro & in Vivo

BACKGROUND: Cell therapies offer a promising potential in promoting bone regeneration. Stem cell therapy presents attractive care modality in treating degenerative conditions or tissue injuries. The rationale behind this is both the expansion potential of stem cells into a large cell population size and its differentiation abilities into a wide variety of tissue types, when given the proper stimuli. A progenitor stem cell is a promising source of cell therapy in regenerative medicine and bone tissue engineering. AIM: This study aimed to compare the osteogenic differentiation and regenerative potentials of human mesenchymal stem cells derived from human bone marrow (hBM-MSCs) or amniotic fluid (hAF-MSCs), both in vitro and in vivo studies. SUBJECTS AND METHODS: Human MSCs, used in this study, were successfully isolated from two human sources; the bone marrow (BM) and amniotic fluid (AF) collected at the gestational ages of second or third trimesters. RESULTS: The stem cells derived from amniotic fluid seemed to be the most promising type of progenitor cells for clinical applications. In a pre-clinical experiment, attempting to explore the therapeutic application of MSCs in bone regeneration, Rat lumbar spines defects were surgically created and treated with undifferentiated and osteogenically differentiated MSCs, derived from BM and second trimester AF. Cells were loaded on gel-foam scaffolds, inserted and fixed in the area of the surgical defect. X-Ray radiography follows up, and histopathological analysis was done three-four months post- operation. The transplantation of AF-MSCs or BM-MSCs into induced bony defects showed promising results. The AF-MSCs are offering a better healing effect increasing the likelihood of achieving successful spinal fusion. Some bone changes were observed in rats transplanted with osteoblasts differentiated cells but not in rats transplanted with undifferentiated MSCs. Longer observational periods are required to evaluate a true bone formation. The findings of this study suggested that the different sources; hBM-MSCs or hAF-MSCs exhibited remarkably different signature regarding the cell morphology, proliferation capacity and osteogenic differentiation potential CONCLUSIONS: AF-MSCs have a better performance in vivo bone healing than that of BM-MSCs. Hence, AF derived MSCs is highly recommended as an alternative source to BM-MSCs in bone regeneration and spine fusion surgeries. Moreover, the usage of gel-foam as a scaffold proved as an efficient cell carrier that showed bio-compatibility with cells, bio-degradability and osteoinductivity in vivo

Synthesis, Characterization, and Magnetic Properties of Pure and EDTA-Capped NiO Nanosized Particles

The effect of ethylenediaminetetraacetic acid (EDTA) as a capping agent on the structure, morphology, optical, and magnetic properties of nickel oxide (NiO) nanosized particles, synthesized by coprecipitation method, was investigated. Nickel chloride hexahydrate and sodium hydroxide (NaOH) were used as precursors. The resultant nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). XRD patterns showed that NiO have a face-centered cubic (FCC) structure. The crystallite size, estimated by Scherrer formula, has been found in the range of 28–33 nm. It is noticed that EDTA-capped NiO nanoparticles have a smaller size than pure nanoparticles. Thus, the addition of 0.1 M capping agent EDTA can form a nucleation point for nanoparticles growth. The optical and magnetic properties were investigated by Fourier transform infrared spectroscopy (FTIR) and UV-vis absorption spectroscopy (UV) as well as electron paramagnetic resonance (EPR) and magnetization measurements. FTIR spectra indicated the presence of absorption bands in the range of 402–425 cm−1, which is a common feature of NiO. EPR for NiO nanosized particles was measured at room temperature. An EPR line with g factor ≈1.9–2 is detected for NiO nanoparticles, corresponding to Ni2+ ions. The magnetic hysteresis of NiO nanoparticles showed that EDTA capping recovers the surface magnetization of the nanoparticles

EFFECT OF SOME OF ORGANIC AND BIO AND/OR MINERAL FERTILIZATION ON VEGETATIVE GROWTH AND CHEMICAL COMPOSITION OF DELONIX REGIA

This work wasexecuted during two successive seasons of 2018 and 2019 in the nursery and laboratory of Fac. Agric., Minia Univ., Egypt to investigate the response of vegetative and root growthand some chemical composition of Delonix regia seedlings to four percentages of humic acid (0, 1, 2 and 4%) and four bio- and/or mineral NPK fertilization treatments (control, 100% NPK, Minia Azotein and 75% NPK plus Minia Azotein), as well as, the interaction between them. All used three percentages of humic acid significantly increased vegetative growth (plant height, stem diameter, the aerial part dry weight), root growth (root number and roots dry weight) and chemical composition (photosynthetic pigments, NPK%, total phenolic and total flavonoids contents) over control. Humic acid at 4% more was effective treatment. All used bio-and/or mineral NPK fertilization treatments significantly increased all studied characters over control. The best treatments were 100% NPK or 75% NPK plus Minia Azotein. It could be recommended to add humic acid at 4% in combination with 100% NPK or 75% NPK plus Minia Azotein to improve growth of Delonix regia

Influence of Methomyl (Copter 90%) on certain biochemical activities and histological structures of land snails Monacha cartusiana

This manuscript was conducted to spotlight the toxic effect of two sub-lethal concentrations of Methomyl (Copter) LC20 (0.075 g/L) and LC40 (0.180 g/L) on some biochemical parameters and histological alterations for land snail Monacha Cartusiana (Muller, 1774). Land snails belong to the class Gastropoda and Phylum Mollusca. This study cleared that both the used concentrations (of Copter) caused a significant increase for activities of three enzymes: alkaline phosphatase (ALP), alanine amino transaminase (ALT), and Aspartate amino transaminase (AST) after 24, 48, and 72 h from exposure starting. In contrast, a total protein (TP) activity decreased at exposure for two concentrations at all lethality periods. Both concentrations of Copter (0.0.75 g/L and 0.180 g/L) have shown histological changes for land snail tissues after 96 h of exposure; digestive gland, hermaphrodite gland, foot, and mantle. Degeneration, rupture, and vacuolization for digestive cells have been shown; furthermore, hemolytic infiltration in connective tissue will be recognized for the digestive gland. The Oocyte and sperm show degenerated with deformation in the connective tissue of the hermaphrodite gland. Likewise, deformation in the muscle fiber layer of the foot in the land snail distorts the epidermis and mucus gland suffering from necrosis. Moreover, mantle shows rapture in epidermis layer, deformed in muscle fiber layer, and vacuolization and necrosis take place in mucus gland. © 2021 The Author(s

HCV Infection among Saudi Population: High Prevalence of Genotype 4 and Increased Viral Clearance Rate

HCV is a major etiological agent of liver disease with a high rate of chronic evolution. The virus possesses 6 genotypes with many subtypes. The rate of spontaneous clearance among HCV infected individuals denotes a genetic determinant factor. The current study was designed in order to estimate the rate of HCV infection and ratio of virus clearance among a group of infected patients in Saudi Arabia from 2008 to 2011. It was additionally designed to determine the genotypes of the HCV in persistently infected patients. HCV seroprevalence was conducted on a total of 15,323 individuals. Seropositive individuals were tested by Cobas AmpliPrep/Cobas TaqMan HCV assay to determine the ratio of persistently infected patients to those who showed spontaneous viral clearance. HCV genotyping on random samples from persistently infected patients were conducted based on the differences in the 5′untranslated region (5′UTR). Anti-HCV antibodies were detected in 7.3% of the totally examined sera. A high percentage of the HCV infected individuals experienced virus clearance (48.4%). HCV genotyping revealed the presence of genotypes 1 and 4, the latter represented 97.6% of the tested strains. Evidences of the widespread of the HCV genotype 4 and a high rate of HCV virus clearance were found in Saudi Arabia