Synthesis and antibacterial activity of nanoenhanced conjugate of Ag-doped ZnO nanorods with graphene oxide

In this paper, we report a successful synthesis of ZnO nanorods using the microwave-assisted technique, solid-state reaction method was utilized for the preparation of Zn_1-xAg_xO (x = 0.05, 0.1), Hummer's modified method for graphene oxide (GO) along with the sonication method to prepare GO-based Ag-doped ZnO (Zn_1-xAg_xO/GO: x  = 0.05, 0.1) nanocomposites. These nanorods and nanocomposites were characterized by X-ray diffraction (XRD), Fourier-transform infrared (FTIR), high-resolution transmission electron microscopy (HRTEM), and Raman spectroscopy for structural properties, scanning electron microscopy (SEM) along with energy dispersive X-ray (EDX) spectroscopy for morphological analysis, and UV-Vis spectroscopy for optical properties. XRD, FTIR, and Raman measurements substantiated that each sample is well crystallized in the single-phase polycrystalline wurtzite hexagonal structure of ZnO. The average crystallite size is found to be in decreasing order ranges 40 nm to 29 nm, respectively, along with a significant reduction in the optical bandgap. The SEM images showed a clear evidence of nanorods of ZnO, while the EDX spectra verified the presence of Zn, Ag, O, and C elements in the synthesized samples with their nominal percentage. Furthermore, the prepared nanocomposites effectively inhibited the growth ofStaphylococcus aureus and Escherichia coli. In comparison to pure ZnO nanorods, GO-based Ag-doped ZnO nanorods showed improved antibacterial activity against both S. aureus and E. coli.

Environmental and health impacts of spraying COVID-19 disinfectants with associated challenges

Coronavirus refers to a group of widespread viruses. The name refers to the specific morphology of these viruses because their spikes look like a crown under an electron microscope. The outbreak of coronavirus disease 2019 (COVID-19) that has been reported in Wuhan, China, in December 2019, was proclaimed an international public health emergency (PHEIC) on 30 January 2020, and on 11 March 2020, it was declared as a pandemic (World Health Organization 2020). The official name of the virus was declared by the WHO as "COVID-19 virus", formerly known as "2019-nCoV", or "Wuhan Coronavirus". The International Committee on Virus Taxonomy's Coronavirus Research Group has identified that this virus is a form of coronavirus that caused a severe outbreak of acute respiratory syndrome in 2002-2003 (SARS). As a result, the latest severe acute respiratory syndrome has been classified as a corona virus 2 (SARS-CoV-2) pathogen by this committee. This disease spread quickly across the country and the world within the first 3 months of the outbreak and became a global pandemic. To stop COVID-19 from spreading, the governing agencies used various chemicals to disinfect different commercial spaces, streets and highways. However, people used it aggressively because of panic conditions, anxiety and unconsciousness, which can have a detrimental impact on human health and the environment. Our water bodies, soil and air have been polluted by disinfectants, forming secondary products that can be poisonous and mutagenic. In the prevention and spread of COVID-19, disinfection is crucial, but disinfection should be carried out with sufficient precautions to minimize exposure to harmful by-products. In addition, to prevent inhalation, adequate personal protective equipment should be worn and chemical usage, concentrations, ventilation in the room and application techniques should be carefully considered. In the USA, 60% of respondents said they cleaned or disinfected their homes more often than they had in the previous months. In addition to the robust use of disinfection approaches to combat COVID-19, we will explore safe preventative solutions here.

Pre- and post-dam river water temperature alteration prediction using advanced machine learning models

Dams significantly impact river hydrology by changing the timing, size, and frequency of low and high flows, resulting in a hydrologic regime that differs significantly from the natural flow regime before the impoundment. For precise planning and judicious use of available water resources for agricultural operations and aquatic habitats, it is critical to assess the dam water's temperature accurately. The building of dams, particularly several dams in rivers, can significantly impact downstream water. In this study, we predict the daily water temperature of the Yangtze River at Cuntan. Thus, this work reveals the potential of machine learning models, namely, M5 Pruned (M5P), Random Forest (RF), Random Subspace (RSS), and Reduced Error Pruning Tree (REPTree). The best and effective input variables combinations were determined based on the correlation coefficient. The outputs of the various machine learning algorithm models were compared with recorded daily water temperature data using goodness-of-fit criteria and graphical analysis to arrive at a final comparison. Based on a number of criteria, numerical comparison between the models revealed that M5P model performed superior (R² = 0.9920, 0.9708; PCC = 0.9960, 0.9853; MAE = 0.2387, 0.4285; RMSE = 0.3449, 0.4285; RAE = 6.2573, 11.5439; RRSE = 8.0288, 13.8282) in pre-impact and post-impact spam, respectively. These findings suggest that a huge wave of dam construction in the previous century altered the hydrologic regimes of large and minor rivers. This study will be helpful for the ecologists and river experts in planning new reservoirs to maintain the flows and minimize the water temperature concerning spillway operation. Finally, our findings revealed that these algorithms could reliably estimate water temperature using a day lag time input in water level. They are cost-effective techniques for forecasting purposes.

Phytoremediation of heavy metals in soil and water: An eco-friendly, sustainable and multidisciplinary approach

Rapid industrialization, increased waste production and surge in agricultural activities, mining, contaminated irrigation water and industrial effluents contribute to the contamination of water resources due to heavy metal (HM) accumulation. Humans employ HM-contaminated resources to produce food, which eventually accumulates in the food chain. Decontamination of these valuable resources, as well as avoidance of additional contamination has long been needed to avoid detrimental health impacts. Phytoremediation is a realistic and promising strategy for heavy metal removal from polluted areas, based on the employment of hyper-accumulator plant species that are extremely tolerant to HMs present in the environment/soil. Green plants are used to remove, decompose, or detoxify hazardous metals in this technique. For soil decontamination, five types of phytoremediation methods have been used viz. phytostabilization, phytodegradation, rhizofiltration, phytoextraction and phytovolatilization. Traditional phytoremediation methods, on the other hand, have significant limits in terms of large-scale application, thus biotechnological efforts to modify plants for HM phytoremediation ways are being explored to improve the efficacy of plants as HM decontamination candidates. It is relatively a new technology that is widely regarded as economic, efficient and unique besides being environment friendly. New metal hyperaccumulators with high efficiency are being explored and employed for their use in phytoremediation and phytomining. Therefore, this review comprehensively discusses different strategies and biotechnological approaches for the removal of various HM containments from the environment, with emphasis on the advancements and implications of phytoremediation, along with their applications in cleaning up various toxic pollutants. Moreover, sources, effects of HMs and factors affecting phytoremediation of HMs metals have also been discussed.

Effect of roasting and frying treatments on aflatoxins and capsaicinoids content and nutritional profile of green chilies ( Capsicum annum L.)

This study was conducted to assess the effect of two thermal treatments, viz. roasting and pan frying (deep frying), on nutritional profile, aflatoxin, and capsaicin content in green chilies. Green chilies were subjected to roasting and frying to reduce the aflatoxin contamination, besides retaining their pungency and nutritional profile. Reversed‐phase HPLC was employed to determine the levels of aflatoxins B1, B2, G1, and G2 in thermally treated and control samples. The proximate compositions of roasted and fried chili samples were significantly (p ≤ .05) different from raw chili (control), except ash content. Vitamin A levels decreased significantly (p ≤ .05) during roasting and were undetected in fried chili samples. Likewise, vitamin C was undetected in both roasted and fried chili samples. Significantly decreasing (p ≤ .05) trends were noticed in capsaicinoids viz. capsaicin and dihydrocapsaicin contents including Scoville Heat Units (SHU) during roasting and frying. However, retention of capsaicinoids was higher in roasted chilies (730.00 ± 4.90 mg/kg) than fried samples (502.56 ± 5.10 mg/kg). The levels of all the four major aflatoxins (AFs)‐ AFB1, AFB2, AFG1, and AFG2 recorded in control were much higher than the limits prescribed by the European Union for spices. Both thermal treatments (roasting and frying) employed proved to be effective in reducing aflatoxins like AFB2, AFG1, and AFG2 in chilies to below the prescribed limits, while as the level of AFB1 was reduced below the limits by only the frying method. This study therefore indicated the substantial impact of frying on aflatoxins.

Nano-engineered materials for sensing food pollutants: Technological advancements and safety issues

Food spoilage and safety are key concerns of the modern food sector. Among them, several types of polluting agents are the prime grounds of food deterioration. In this context, nanotechnology-based measures are setting new frontiers to strengthen food applications. Herein, we summarize the nanotechnological dimension of the food industry for both processing and packaging applications. Active bioseparation, smart delivery, nanoencapsulation, nutraceuticals, and nanosensors for biological detection are a few emerging topics of nanobiotechnology in the food sector. The development of functional foods is another milestone set by food nanotechnology by building the link between humans and diet. However, the establishment of optimal intake, product formulations, and delivery matrices, the discovery of beneficial compounds are a few of the key challenges that need to be addressed. Nanotechnology provides effective solutions for the aforementioned problem giving various novel nanomaterials and methodologies. Various nanodelivery systems have been designed, e.g., cochleate, liposomes, multiple emulsions, and polysaccharide-protein coacervates. However, their real applications in food sciences are very limited. This review also provides the status and outlook of nanotechnological systems for future food applications.

Sustainable nanotechnology based wastewater treatment strategies: achievements, challenges and future perspectives

Nanotechnology is being an emerging science for wastewater treatment requires more research emphasis and depth knowledge. For wastewater treatment, different forms of nanomaterials are used based on the type of contaminants and treatment efficiency desired. With the development in the field of nanomaterials, novel and emerging nanomaterials are coming into existence. The nanomaterials used for wastewater treatment can be carbon, single-walled carbon nanotubes, multiple walled carbon nanotubes, covalent organic frameworks, metal and metal oxide- based nanoparticles. Graphene based nanoparticles, their oxides (GO) and reduced graphene oxide (rGO) find tremendous applicability to be used in wastewater treatment purposes. Due to the introduction of graphene oxide nanoparticles in the adsorbent materials, their adsorption capacities have get enhanced and such materials have also improved the mechanical stability of the adsorbent. Ferric oxide shows greater adsorption capacities for organic pollutants. Furthermore, magnetic nano-powder confers a low adsorption capacity for phenols. Pyrrolidone reduced graphene oxide (PVP-RGO) nanoparticles have been used as adsorbents for the elimination of inorganic target contaminant copper, with great adsorption (1698 mg/g). The present study comprehensively reviews nanotechnology as a wastewater treatment strategy besides enlightening its safety issues and efficiency. The novelty of this article is that it highlights the overview of recent applications of various types of nanomaterials and research works releated to it. Such an approach will be helpful to get insights into technological advances, applications and future challenges of nanotechnology implementation for wastewater treatment.

Vulnerability of municipal solid waste: An emerging threat to aquatic ecosystems

Dumping waste materials into aquatic ecosystems leads to pollution, which directly and indirectly poses a danger to all life forms. Currently, huge quantities of wastes are generated at a global scale with varying constituents, including organic fractions, emerging contaminants and toxic metals. These wastes release concentrated contaminants (leachates), which are lethal for all ecosystems around the globe because they contain varying concentrations of chemical constituents with BOD₅ and COD in the order of 2 × 10⁴-2.7 × 10⁴ mg/L, and 3.4 × 10⁴-3.8 × 10⁴ mg/L, respectively. Herein, in-depth knowledge of municipal solid waste dumping into the aquatic ecosystems, changes in physicochemical characteristics, availability of in-/organic contaminants, and long-term unhealthy effects are presented. Moreover, an attempt has been made here to summarize the facts related to identifying the deadly impacts of waste on different ecosystem components. The unresolved challenges of municipal waste management are emphasized, which will help employ suitable waste management techniques and technologies to conserve the everlasting freshwater resources on earth.

Investigating the effect of oxalic acid and salicylic acid treatments on the post-harvest life of temperate grown apricot varieties (Prunus armeniaca) during controlled atmosphere storage

This study aimed at investigating the influence of different postharvest treatments with oxalic acid (OA) and salicylic acid (SA) on quality attributes and postharvest shelf life of temperate grown apricot varieties stored under controlled atmosphere (CA) storage conditions. After each treatment was given, the samples were stored in CA store maintained at a temperature of 0 °C, 90 ± 5% relative humidity, 5% oxygen and 15% carbon dioxide for 30 days. Results indicated that both OA and SA treatments significantly (p ≤ 0.05) retained total soluble solids, titratable acidity, color profile, ascorbic acid content and total phenolic content of apricot varieties and had a positive effect on antioxidant activity and texture of samples compared to control. However, carotenoid content was found to be higher in control. Both the treatments reduced chilling injury index, weight loss and decay percentage of samples. Moreover, it was found that SA treatment was the most effective treatment in maintaining visual color of apricots while OA maintained fruit firmness and effectively decreased the decay percentage and chilling injury index of apricot varieties. In conclusion, it was found that both OA and SA have the potential to extend storage life of apricots and maintain quality attributes of the crop during CA storage.

Impact of COVID-related lockdowns on environmental and climate change scenarios

The outbreak of COVID-19 pandemic has emerged as a major challenge from human health perspective. The alarming exponential increase in the transmission and fatality rates related to this disease has brought the world to a halt so as to cope up with its stern consequences. This has led to the imposition of lockdown across the globe to prevent the further spread of this disease. This lock down brought about drastic impacts at social and economic fronts. However, it also posed some positive impacts on environment as well particularly in the context of air quality due to reduction in concentrations of particulate matter (PM), NO₂ and CO across the major cities of the globe as indicated by several research organizations. In China, Italy, France and Spain, there were about 20-30% reduction in NO₂ emission while in USA 30% reduction in NO₂ emission were observed. Compared to previous year, there was 11.4% improvement in the air quality in China. Drastic reductions in NO (-77.3%), NO₂ (-54.3%) and CO (-64.8%) (negative sign indicating a decline) concentrations were observed in Brazil during partial lockdown compared to the five year monthly mean. In India there were about -51.84, -53.11, -17.97, -52.68, -30.35, 0.78 and -12.33% reduction in the concentration of PM_10, PM_2.5, SO_2, NO_2, CO, O₃ and NH₃ respectively. This article highlights the impact of lockdown on the environment and also discusses the pre and post lockdown air pollution scenario across major cities of the world. Several aspect of environment such as air, water, noise pollution and waste management during, pre and post lockdown scenario were studied and evaluated comprehensively. This research would therefore serve as a guide to environmentalist, administrators and frontline warriors for fighting our the way to beat this deadly disease and minimize its long term implications on health and environment.

Molecular prevalence of Babesia bigemina in Rhipicephalus microplus ticks infesting cross-bred cattle of Punjab, India

Babesiosis is an economically important tick-borne apicomplexan protozoan disease of cattle in tropical and subtropical regions. In the present study, Rhipicephalus microplus engorged female ticks were collected from 135 apparently healthy cattle from different agro-climatic zones of Punjab, India, to investigate the carrier status of Babesia bigemina infection in vector tick by using microscopy and PCR based assays. PCR when applied on DNA extracted from the egg masses harvested from ticks showed 1.48% (2/135) samples as positive, whereas 4.44% (6/135) samples were positive when product of primary PCR was used as template in nPCR. Further, among the DNA samples isolated from the unfed larval stages that emerged from egg masses laid by ticks, only 1.48% (2/135) samples were detected as positive for B. bigemina in PCR, while 7.41% (10/135) samples were detected positive in nPCR assay. Statistically, non-significant (p > 0.05) difference in prevalence rates was observed across different agro-climatic zones and between different age groups of cattle from which engorged ticks were collected. It can, thus, be concluded that prevalence of B. bigemina in the vector tick, R. microplus in Punjab state of India indicates an endemic status of the organism and a further study is needed for the management and control of the bovine babesiosis.

Molecular detection of Babesia bigemina infection in apparently healthy cattle of central plain zone of Punjab

Bovine babesiosis is an important tick-borne disease caused by the parasites belonging to the genus Babesia, distributed worldwide and infecting a wide range of domesticated and wild cattle, occasionally man. The present study was conducted to determine the prevalence of B. bigemina infection in apparently healthy cattle from central plain zone of Punjab, India. Examination of Giemsa-stained peripheral thin blood smears revealed 2.45 % (5/204) animals to be positive for piroplasms of B. bigemina. However, genomic DNA isolated from these blood samples when subjected to primary PCR revealed a positivity of 7.35 % (15/204) as detected by the amplification of a 278-bp product in the agarose gel. PCR products obtained from the primary PCR of B. bigemina, when employed as template in nested PCR produced the amplicons of desired size (170 bp) was detected in 30.39 % (62/204) of the samples. It can thus be concluded that B. bigemina infection is prevalent in apparently healthy cattle population of this region and PCR assays can serve as a valuable tool for epidemiological studies in endemic areas.

Coprological investigation on neonatal bovine cryptosporidiosis in Ludhiana, Punjab

An overall prevalence of 38.90 % was recorded for bovine cryptosporidiosis on coprological examination of 144 faecal samples collected from neonatal cattle calves from organised dairy farms in and around Ludhiana, Punjab by modified Ziehl-Neelsen staining. Further, a gradual decline in the percent prevalence was seen with increase in the age of the host from <1 month (64.1 %) to 4-5 months (12.5 %). The highest prevalence was recorded during the monsoon season (47.06 %) followed by summer (37.73 %) and winter (30.0 %) season and the seasonal variation was statistically significant (p ≤ 0.05). Female calves showed higher prevalence (44.32 %) than their male counterparts (27.66 %). Further, prevalence of cryptosporidiosis was significantly higher (p ≤ 0.05) in the diarrhoeic calves (52.70 %) as compared to the non-diarrhoeic (24.28 %) thus indicating a relatively higher risk (1.75 times) of the disease in diarrhoeic than normal calves.

Comparison of nested PCR and microscopy for the detection of cryptosporidiosis in bovine calves

The comparative efficacies of different conventional parasitological methods and nested PCR for diagnosis of bovine cryptosporidiosis in faecal samples were evaluated. Among the 100 samples collected from calves in and around Ludhiana Direct faecal smear staining technique revealed 25.0 % positivity for the oocysts of Cryptosporidium spp. with sensitivity and specificity of 68.12 and 92.98 %, respectively. Zinc sulphate solution floatation and saturated sugar solution floatation staining techniques showed sensitivity and specificity of 83.92 and 96.36; 81.03 and 98.14 %, respectively. Products of the primary PCR of Cryptosporidium spp. directed against small subunit (18S) ribosomal RNA when employed as template in nested PCR produced the amplicons of desired size (834 bp) in 47.0 % of the samples. Amplification of 834 bp fragment was also observed in positive control, while no amplification was observed in negative control. Results indicated PCR assays as highly sensitive and specific techniques for the screening of the samples for Cryptosporidium spp. but in developing countries and under field conditions where limited resources do not allow the application of PCR assays, concentration staining methods are recommended.

Novel antibodies in the treatment of non-Hodgkin's lymphoma

Monoclonal antibodies (mAbs) have revolutionised the treatment of malignancies, especially non-Hodgkin's lymphoma (NHL). Antibody-based therapies target tumour cells expressing a specific antigen while sparing the majority of normal cells leading to a decrease in treatment-associated toxicity. Rituximab, a monoclonal antibody directed against CD20 on B cells, was the first monoclonal antibody to be approved by the US Food and Drug Association (FDA) in 1997 for the treatment of patients with relapsed/refractory, follicular or low-grade NHL . However, it was soon realised that not all patients respond to rituximab therapy and close to 60% of patients with follicular lymphoma who were previously sensitive to rituximab become 'resistant' to repeat rituximab therapy. This led to further attempts to improve the antitumour activity of anti-CD20 mAbs (i.e. 2nd/3rd generation anti-CD20s), and to identify additional potential targets on lymphoma cells other than CD20. A number of these antibodies directed against lymphoma cell targets other than CD20 are now undergoing development, many of which are currently in clinical trials. This manuscript focuses on an overview of these 'non-anti-CD20' novel mAbs for NHL.