Structural, Optical and Electrical Properties of Cu0.6CoxZn0.4-xFe2O4 (x = 0.0, 0.1, 0.2, 0.3, 0.4) Soft Ferrites.

A series of cobalt-inserted copper zinc ferrites, Cu0.6CoxZn0.4-xFe2O4 (x = 0.0, 0.1, 0.2, 0.3, 0.4) having cubic spinel structure were prepared by the coprecipitation method. Various characterization techniques, including XRD, FTIR, UV-vis and I-V were used to investigate structural optical and electrical properties, respectively. The lattice constant was observed to be decreased as smaller ionic radii Co2+ (0.74 Å) replaced the higher ionic radii Zn2+ (0.82 Å). The presence of tetrahedral and octahedral bands was confirmed by FTIR spectra. Optical bandgap energy was determined in the range of 4.44-2.05 eV for x = 0.0 to 0.4 nanoferrites, respectively. DC electrical resistivity was measured and showed an increasing trend (5.42 × 108 to 6.48 × 108 Ω·cm) with the addition of cobalt contents as cobalt is more conductive than zinc. The range of DC electrical resistivity (108 ohm-cm) makes these nanomaterials potential candidates for telecommunication devices.

Bioaccumulation of Heavy Metals and their Genotoxic Effect on Freshwater Mussel.

Contamination of fresh water bodies like riverine system is utmost concerned environmental issue. This study was aimed to assess the concentration of heavy metals in River Kabul and their bioaccumulation by freshwater mussel. Comet assay was used to evaluate the genotoxic effect of heavy metals on hemocytes of freshwater mussel. The concentration of heavy metals in water was in the order of Zn > Pb > Ni > Cu > Mn > Fe > Cr > Cd, in sediments were Fe > Zn > Cr > Ni > Mn > Pb > Cu > Cd and in the soft tissues of freshwater mussel were in order of Fe > Zn > Mn > Pb > Cu > Cr > Ni > Cd. The hemocytes of mussels from polluted sites showed significantly higher (p < 0.05) DNA damage as compared to reference site. The study showed that pollutants from industries, municipal, domestic and agricultural sources cause heavy metals contamination in River Kabul.

Impact of marine pollution in green mussel Perna viridis from four coastal sites in Karachi, Pakistan, North Arabian Sea: histopathological observations.

Pathological changes are regarded as a standard technique to monitor the effects of pollutants in marine animals. Histopathological examination of the population of green mussel Perna viridis (L.) from four sites in Pakistan, namely, Manora Channel, Rehri Creek, Sandspit Backwaters and Bhanbore was conducted. The first three sites are on the Karachi coast, whereas the fourth one, Bhanbore is situated outside Karachi, and is considered to be less polluted. Two types of parasites, Rickettsia-like organisms and metacestode were found in the mussels studied. In the present study, we observed various pathological lesions, such as inflammatory responses, granulocytomas, lipofuscin pigments, vacuolation in the digestive gland and gonads, lamellar fusion and dilated hemolymphatic sinus in the gills of P. viridis. These observations indicate the extent of environmental pollution in the studied areas. Although, Bhanbore is considered to be relatively less polluted compared to other three sites, the present results have revealed that the waters of Bhanbore are also polluted as evidenced by the pathological changes observed in the mussels collected from there.

Aloe-inspired eco-friendly synthesis of Ag/ZnO heterostructures: boosting photocatalytic potential.

The current research focuses on the development of Ag-ZnO heterostructures through a "bottom-up" approach involving the assembly and extraction of Aloe barbadensis Miller gel. These heterostructures composed of metals/semiconductor oxide display distinct and notable optical, electrical, magnetic, and chemical properties that are not found in single constituents and also exhibit photocatalytic applications. These synthesized heterostructures were characterized by XRD, FTIR, SEM, and UV-visible spectroscopy. The high peak intensity of the Ag/ZnO composite shows the high crystallinity. The presence of Ag-O, Zn-O, and O-H bonding is verified using FTIR analysis. SEM analysis indicated the formation of spherical shapes of Ag/ZnO heterostructures. The Zn, O, and Ag elements are further confirmed by EDX analysis. Ag-ZnO heterostructures exhibited excellent photocatalytic activity and stability against the degradation of tubantin red 8BL dye under visible light irradiation.

Improving the Cycling Stability of Aqueous Zinc-Ion Batteries by Preintercalation of Polyaniline in Hydrated Vanadium Oxide.

This paper reports the synthesis and characterization of hydrated vanadium oxide (VOH) and chemically preintercalated polyanilines in VOH, labeled as PAVO-H as the cathode material for aqueous zinc-ion batteries. Synthesized PAVO-H has a high surface area and rod-shaped morphology. PAVO-H has an increased interlayer distance of 13.36 Å. PAVO-H offers high specific capacities of 330 and 225 mAh g-1 at 50 mA g-1 and 4 A g-1 of current densities, respectively, with a 92% capacity retention rate of over 3000 cycles. The preintercalation of polyaniline is likely to catalyze the redox reaction and facilitate and simplify transport kinetics. It is also possible that the preintercalation of polyaniline permits the insertion of large hydrated Zn ions and reduces the formation of zinc basic salts.

Effect of Mn Doped on Structural, Optical, and Dielectric Properties of BiFe1-xMnxO3 for Efficient Antioxidant Activity.

Manganese-doped bismuth ferrites were synthesized using the coprecipitation method with the green extract Azadirachta indica. Our incorporation of the transition element, manganese, into bismuth ferrites tackles the challenge of increased leakage current often observed in intrinsic bismuth ferrites. We gained key insights through a comprehensive examination of the structural, dielectric, and optical properties of these materials, utilizing Fourier transform infrared spectroscopy (FTIR), impedance spectroscopy, and UV-visible spectroscopy, respectively. The formation of an octahedral geometry was confirmed using the FTIR technique. UV-visible spectroscopy indicated that 2% Mn doping is optimal, while we obtained a low band gap energy (2.21 eV) and high refractive index (3.010) at this amount of doping. The manufactured materials exhibited the typical ferrite-like dielectric response, that is, the dielectric parameter gradually decreased as the frequency increased and then stayed constant in the high-frequency range. Using the diphenylpicrylhydrazyl (DPPH) free radical assay, we also examined the antioxidant activity of bismuth ferrites. We concluded that among different Mn-doped BiFeMnO3-based nanomaterials, the 2 wt % Mn-doped BiFeMnO3 shows the highest antioxidant activity. This finding substantiates the efficacy of the optimized material with regard to its potent antioxidant activity, positioning it as a promising candidate for potential biomedical applications.

Photovoltaic Properties of ZnO Films Co-Doped with Mn and La to Enhance Solar Cell Efficiency.

In the present investigation, ZnO films co-doped with Mn and La were synthesized by the sol-gel technique. XRD analysis revealed that ZnO had a hexagonal structure. Mixed hexagonal and cubic phases appeared in ZnO containing Mn (1%) and La (1.5%). The grain size, d-spacing, unit cell, lattice parameters, atomic packing fraction, volume, strain, crystallinity, and bond length of co-doped ZnO films were determined as a function of doped ion contents. Through UV analysis, it was found that pristine ZnO had Eg = 3.5 eV, and it decreased when increasing the doping concentration, reaching the minimum value for the sample with 1% Mn and 1% La. The optical parameters of the films, such as absorption, transmittance, dielectric constants, and refractive index, were also analyzed. DSSCs were fabricated using the prepared ZnO films. For pure ZnO film, the values were: efficiency = 0.69%, current density = 2.5 mAcm-2, and open-circuit voltage = 0.56 V. When ZnO was co-doped with Mn and La, the efficiency increased significantly. DSSCs with a ZnO photoanode co-doped with 1% Mn and 1% La exhibited maximum values of Jsc = 4.28 mAcm-2, Voc = 0.6 V, and efficiency = 1.89%, which is 174% better than pristine ZnO-based DSSCs. This material is good for the electrode of perovskite solar cells.

Evaluation of prevalence and risk factors associated with Cryptosporidium infection in rural population of district Buner, Pakistan.

BACKGROUND: Cryptosporidium spp are important intestinal protozoan parasites that cause diarrhea in humans, domestic and wild animals. Its infection remains a main public health concern however, the epidemics in human being is still unclear, particularly in developing countries. There are several factors that may enhance the spreading of this parasite in human population especially in young children. METHODOLOGY: A questionnaire was designed to obtain the demographic and clinical data from the participants. A total of 425 stool samples were collected from suspected children (aged 3-10 years) in different hospitals and villages. The initial screening was performed with modified Ziehl Neelsen (mZN) staining technique followed by polymerase chain reaction (PCR). Several potential risk factors were also assessed through the obtained information from suspected individuals. RESULTS: Out of all 425 collected samples, 127 were observed positive by mZN with a prevalence of 29.88% (127/425). The 127 mZN positive samples together with 50 mZN negative samples were processed for molecular analysis through PCR assay. Among them, 71 out of 127 mZN positive samples and 4 out of 50 mZN negative samples were found positive by PCR. The molecular analysis showed that Cryptosporidium parvum was the main cause of infection in children. The results revealed that individuals exposed to diarrhea were more likely to be infected with Cryptosporidium infection while several environmental factors may also play a key role in spreading of this parasite. CONCLUSIONS/SIGNIFICANCE OF THE STUDY: The current high prevalence of Cryptosporidium infection may be due to the lack of awareness and routine based testing in identification of this parasite in District Buner. Further studies are required to determine the importance of Cryptosporidium infection in this area as well as across the country and to find out the possible risk factors that may be associated with the occurrence of this protozoan. There is, however, an urgent need for laboratory-based observational studies to develop a more dynamic estimate of the cryptosporidial disease burden in the region.

Bioaccumulation of Heavy Metals in Water, Sediments, and Tissues and Their Histopathological Effects on Anodonta cygnea (Linea, 1876) in Kabul River, Khyber Pakhtunkhwa, Pakistan.

The present investigation aimed to assess the concentrations of selected heavy metals in water and sediments and their bioaccumulation in tissues of freshwater mussels and their histopathological effects on the digestive gland, gills, and gonads of Anodonta cygnea. Water, sediments, and freshwater mussel samples were collected at four sites, that is, reference and polluted sites, along the Kabul River, Khyber Pakhtunkhwa. The polluted sites were receiving effluents from the industrial, agricultural, municipal, and domestic sources. The order of metals in the water was Zn > Pb > Ni > Cu > Mn > Fe > Cr > Cd, in sediments the order was Fe > Zn > Cr > Ni > Mn > Pb > Cu > Cd, and in the soft tissues the order was Fe > Zn > Mn > Pb > Cu > Cr > Ni > Cd. Histopathological alterations observed in polluted sites of Kabul River were inflammation, hydropic vacuolation, and lipofuscin pigments (in digestive gland), gill lamellar fusion, dilated hemolymphatic sinus, clumping, and generation of cilia and hemocytic infiltration (in gills), and atresia, necrosis, granulocytoma, hemocytic infiltration, and lipofuscin pigments (in gonads). The histopathological alterations in the organs of Anodonta cygnea can be considered as reliable biomarkers in biomonitoring of heavy metal pollution in aquatic ecosystems.