Recent advances in heavy metal/metalloid ion treatment from wastewater using nanocomposites and bionanocomposites

Wastewater remediation is of paramount importance for the water-stressed modern civilization from the perspective of sustainable development and the management of limited freshwater resources. Contaminants such as heavy metal and metalloid ions, toxic dyes, and pathogenic microbes present in the aquatic ecosystem have adverse effects not only on the environment but also on human health. Traditional wastewater remediation processes are costly, energy-consuming, and have less efficiency in removing pollutants from wastewater. Multi-phasic nanomaterials or nanocomposites have enormous potential for removing contaminants from water bodies. These materials have an enormous tunable surface area for interacting with the target toxicants and are extremely stable in the aquatic system, but they readily agglomerate. Many research groups have exploited biosorption, bioleaching, and bioprecipitation capacities of fungal hyphae for wastewater remediation. Recently, researchers have attempted to explore the synergistic effect of the bionanocomposite of fungal hyphae and nanomaterials for removing pollutants from wastewater. This bionanocomposite has already shown promise as a superior material for wastewater treatment and can easily be separated from the polluted water for reuse over several cycles. The bionanocomposite-mediated decontamination of water can lead to a total paradigm shift in wastewater management strategies

Occupational Hepatitis B Exposure: A Peek into Indian Dental Students’ Knowledge, Opinion, and Preventive Practices

Objective. To determine the level of knowledge, opinions, and preventive practices followed by dental students against Hepatitis B. The study also explored if any correlation existed between knowledge, opinion, and preventive practices score. Materials and Methods. A cross-sectional study was conducted in a dental teaching institution. The subjects comprised 216 dental students. The study was conducted using a pretested, self-administered questionnaire. The questionnaire was prepared to assess knowledge, opinion, and preventive practices against Hepatitis B. Kruskal-Wallis and Kendall Tau test were performed. Results. The study found that only 44.4% of the students were vaccinated with Hepatitis B vaccine. 59.3% of the students reported washing their hands after contact with patient’s body fluids. 63.9% used personal protective measures like facemask, aprons, head cap, eye shields, and so forth, while treating patients. Median knowledge, opinion, and practice scores were found to be 5.00, 3.00, and 3.00, respectively. Significant correlation was obtained between knowledge and preventive practices score (r=0.385, p value <0.0001). Conclusion. Effective measures need to be taken to improve preventive practices of the students to prevent them from risk of Hepatitis transmission. Mandatory vaccination against Hepatitis B needs to be implemented

Dental caries experience in high risk soft drinks factory workers of South India: A comparative study

Background: The consumption of soft-drinks has been associated with dental caries development. Objective: The aim was to evaluate dental caries experience amongst the workers working in soft-drink industries located in South India and compare it with other factory workers. To evaluate the validity of specific caries index (SCI), which is newer index for caries diagnosis. Materials and Methods: This was a cross-sectional study carried out among 420 workers (210 in soft-drinks factory and 210 in other factories), in the age group of 20-45 years of Udupi district, Karnataka, India. Index used for clinical examination was decayed, missing, filled surfaces (DMFS) index and SCI. Results: The mean and standard deviation (SD) of decayed surface (5.8 ± 1.8), missing surface (4.3 ± 2) and filled surface (1.94 ± 1.95) and total DMFS score (12.11 ± 3.8) in soft-drinks factory workers were found to be significantly higher than the other factory workers. The total SCI score (mean and SD) was found to be significantly higher in soft-drinks factory workers (5.83 ± 1.80) compared with other factory workers (4.56 ± 1.45). There was a high correlation obtained between SCI score and DMFS score. The regression equation given by DMFS = 1.178 + 1.866 (SCI scores). Conclusion: The caries experience was higher in workers working in soft-drinks factory and this study also showed that specific caries index can be used as a valid index for assessing dental caries experience

Biochemical‑, Biophysical‑, and Microarray-Based Antifungal Evaluation of the Buffer-Mediated Synthesized Nano Zinc Oxide: An in Vivo and in Vitro Toxicity Study

Here we describe a simple, novel method of zinc oxide nanoparticle (ZNP) synthesis and physicochemical characterization. The dose-dependent antifungal effect of ZNPs, compared to that of micronized zinc oxide (MZnO), was studied on two pathogenic fungi: <i>Aspergillus niger</i> and <i>Fusarium oxysporum</i>. Superoxide dismutase (SOD) activity, ascorbate peroxidase activity, catalase activity, glutathione reductase (GR) activity, thiol content, lipid peroxidation, and proline content in ZNP-treated fungal samples were found to be elevated in comparison to the control, which strongly suggested that the antifungal effect of ZNPs was due to the generation of reactive oxygen species (ROS). Protein carbonylation, another marker of oxidative stress, was also evaluated by the dinitrophenyl hydrazine (DNPH) binding assay and Fourier transform infrared (FTIR) spectral analysis followed by Western blot and microarray analysis of fungal samples to confirm ROS generation by ZNPs. Micrographic studies for the morphological analysis of fungal samples (ZNP-treated and a control) exhibited an alteration in fungal morphology. The bioavailability of ZNPs on fungal cell was confirmed by energy-dispersive X-ray (EDX) analysis followed by high-resolution transmission electron microscopy (HR-TEM) and confocal microscopic analysis of the fungal samples. In vivo acute oral toxicity, acetylcholine esterase activity, and a fertility study using a mice model were also investigated for ZNPs. The long-term toxicity of ZNPs through intravenous injection was evaluated and compared to that of MZnO. The in vitro comparative toxicity of ZNPs and MZnO was evaluated on MRC-5 cells with the help of water-soluble tetrazolium (WST-1) and lactate dehydrogenase (LDH) assays. These results suggested that ZNPs could be used as an effective fungicide in modern medical and agricultural sciences