Concepts of circular economy for sustainable management of electronic wastes: challenges and management options.

The electronic and electrical industrial sector is exponentially growing throughout the globe, and sometimes, these wastes are being disposed of and discarded with a faster rate in comparison to the past era due to technology advancements. As the application of electronic devices is increasing due to the digitalization of the world (IT sector, medical, domestic, etc.), a heap of discarded e-waste is also being generated. Per-capita e-waste generation is very high in developed countries as compared to developing countries. Expansion of the global population and advancement of technologies are mainly responsible to increase the e-waste volume in our surroundings. E-waste is responsible for environmental threats as it may contain dangerous and toxic substances like metals which may have harmful effects on the biodiversity and environment. Furthermore, the life span and types of e-waste determine their harmful effects on nature, and unscientific practices of their disposal may elevate the level of threats as observed in most developing countries like India, Nigeria, Pakistan, and China. In the present review paper, many possible approaches have been discussed for effective e-waste management, such as recycling, recovery of precious metals, adopting the concepts of circular economy, formulating relevant policies, and use of advance computational techniques. On the other hand, it may also provide potential secondary resources valuable/critical materials whose primary sources are at significant supply risk. Furthermore, the use of machine learning approaches can also be useful in the monitoring and treatment/processing of e-wastes. HIGHLIGHTS: In 2019, ~ 53.6 million tons of e-wastes generated worldwide. Discarded e-wastes may be hazardous in nature due to presence of heavy metal compositions. Precious metals like gold, silver, and copper can also be procured from e-wastes. Advance tools like artificial intelligence/machine learning can be useful in the management of e-wastes.

Role of colour Doppler in predicting foetal outcome in maternal anaemia.

Context: Anaemia is the most common nutritional deficiency in Indian pregnant females. It ensues foetal hypoxia resulting in different compensatory mechanisms in the foetus which may result in adverse perinatal outcomes. Colour Doppler can be used to measure these hemodynamic changes of the foetus ahead of the clinical manifestations, guiding the obstetrician for the appropriate management and circumventing any dire complication. Aims: The aim of this study is to detect foetal haemodynamic changes associated with maternal anaemia and assess the parameters which predict these changes accurately. Settings and Design: Prospective cohort study. Materials and Methods: Two hundred and forty pregnant females in the third trimester, divided into four groups based on their haemoglobin levels in the non-anaemic, mild, moderate and severe anaemic groups, were included in the study. These patients were followed up for foetal outcome in terms of effective foetal weight, APGAR score and neonatal intensive care unit admission. Statistical Analysis Used: Analysis of Variance Appearance, Pulse, Grimace, Activity and Respiration (ANOVA) test was used to compare the quantitative variables. SPSS software was used. Results: The middle cerebral artery (MCA) Doppler indices and cerebroplacental ratio (CPR) values were increasing while umbilical Doppler indices were decreasing with the increasing severity of anaemia. CPR was found to be the most sensitive predictor for foetal outcome. Conclusions: Maternal anaemia results in foetal hypoxia which can be measured in terms of foetal Doppler indices. CPR was found to be more sensitive than the umbilical or MCA in predicting foetal hypoxia and in turn the perinatal outcome of foetuses of anaemic pregnant females. The foetuses with low CPR values will require urgent intervention to improve the outcomes.

Nitrate contamination in water resources, human health risks and its remediation through adsorption: a focused review.

The level of nitrate in water has been increasing considerably all around the world due to vast application of inorganic nitrogen fertiliser and animal manure. Because of nitrate's high solubility in water, human beings are getting exposed to it mainly through various routes including water, food etc. Various regulations have been set for nitrate (45-50 mgNO3-/L) in drinking water to protect health of the infants from the methemoglobinemia, birth defects, thyroid disease, risk of specific cancers, i.e. colorectal, breast and bladder cancer caused due to nitrate poisoning. Different methods like ion exchange, adsorption, biological denitrification etc. have the ability to eliminate the nitrate from the aqueous medium. However, adsorption process got preference over the other approaches because of its simple design and satisfactory results especially with surface modified adsorbents or with mineral-based adsorbents. Different types of adsorbents have been used for this purpose; however, adsorbents derived from the biomass wastes have great adsorption capacities for nitrate such as tea waste-based adsorbents (136.43 mg/g), carbon nanotube (142.86 mg/g), chitosan beads (104 mg/g) and cetyltrimethylammonium bromide modified rice husk (278 mg/g). Therefore, a thorough literature survey has been carried out to formulate this review paper to understand various sources of nitrate pollution, route of exposure to the human beings, ill effects along with discussing the key developments as well as the new advancements reported in procuring low-cost efficient adsorbents for water purification.

Biodegradation of 4-chlorophenol in batch and continuous packed bed reactor by isolated Bacillus subtilis.

In present work, biodegradation of 4-Chlorophenol (4-CP) has been successfully achieved using bacteria i.e. Bacillus subtilis (MF447841.1), which was isolated from the wastewater of a nearby drain of Hyundai Motor Company service centre, Agartala, Tripura (India). Geonomic identification was carried out by 16 S rDNA technique and phylogenetic processes. Both, batch and column mode of experiments were performed to optimize various parameters (initial concentration, contact time, dosages etc.) involved in the significant biodegradation of 4-CP. Based on R2 value (0.9789), the Levenspiel's model was found to be best fit than others. The kinetic parameters; specific growth rate (µ), yield of cell mass (YX/S), and saturation constant (KS), were obtained as 0.6383 (h-1), 0.35 (g/g), and 0.006884 (g/L), respectively. The isolated strain has shown the ability of degrading 4-CP up to 1000 mg/L initial concentration within 40 h. Bacterial strain was immobilized via developing calcium alginate beads along by optimizing weight proportion of calcium chloride and sodium alginate and size of the bead for further experiments. Various process parameters i.e. initial feed concentration, bed height, rate of flow of were optimized during packed bed reactor (PBR) study. Maximum biodegradation efficiency of 4-CP was observed as 45.39% at initial concentration of 500 mg/L within 105 min, using 2 mm size of immobilized beads which were formed using 3.5% w/v of both calcium chloride and sodium alginate within. Thus, Bacillus subtilis (MF447841.1) could be used for biological remediation of 4-CP pollutant present in wastewater. Moreover, because of affordable and eco-friendly nature of water treatment, relatively it has the better scope of commercialization.

Disinfection by-products in drinking water: Occurrence, toxicity and abatement.

Disinfection means the killing of pathogenic organisms (e.g. bacteria and its spores, viruses, protozoa and their cysts, worms, and larvae) present in water to make it potable for other domestic works. The substances used in the disinfection of water are known as disinfectants. At municipal level, chlorine (Cl2), chloramines (NH2Cl, NHCl2), chlorine dioxide (ClO2), ozone (O3) and ultraviolet (UV) radiations, are the most commonly used disinfectants. Chlorination, because of its removal efficiency and cost effectiveness, has been widely used as method of disinfection of water. But, disinfection process may add several kinds of disinfection by-products (DBPs) (∼600-700 in numbers) in the treated water such as Trihalomethanes (THM), Haloacetic acids (HAA) etc. which are detrimental to the human beings in terms of cytotoxicity, mutagenicity, teratogenicity and carcinogenicity. In water, THMs and HAAs were observed in the range from 0.138 to 458 µg/L and 0.16-136 µg/L, respectively. Thus, several regulations have been specified by world authorities like WHO, USEPA and Bureau of Indian Standard to protect human health. Some techniques have also been developed to remove the DBPs as well as their precursors from the water. The popular techniques of DBPs removals are adsorption, advance oxidation process, coagulation, membrane based filtration, combined approaches etc. The efficiency of adsorption technique was found up to 90% for DBP removal from the water.

Synthesis of fungal glycolipid asperamide B and investigation of its ability to stimulate natural killer T cells.

The relationship between mold and asthma has been recognized for decades, but the molecular triggers of asthma generated by molds have not been fully elucidated. A glycolipid generated by Aspergillus species has recently been identified that triggers airway hyperreactivity via natural killer T cell activation. The synthesis of this glycolipid and structural variants designed to allow identification of the features of this glycolipid required for recognition by natural killer T cells is described.

Invariant natural killer T cells recognize a fungal glycosphingolipid that can induce airway hyperreactivity.

Aspergillus fumigatus is a saprophytic fungus that is ubiquitous in the environment and is commonly associated with allergic sensitization and severe asthma in humans. Although A. fumigatus is recognized by multiple microbial pattern-recognition receptors, we found that an A. fumigatus-derived glycosphingolipid, asperamide B, directly activates invariant natural killer T (iNKT) cells in vitro in a CD1d-restricted, MyD88-independent and dectin-1-independent fashion. Moreover, asperamide B, when loaded onto CD1d, directly stained, and was sufficient to activate, human and mouse iNKT cells. In vivo, asperamide B rapidly induced airway hyperreactivity, which is a cardinal feature of asthma, by activating pulmonary iNKT cells in an interleukin-33 (IL-33)-ST2-dependent fashion. Asperamide B is thus the first fungal glycolipid found to directly activate iNKT cells. These results extend the range of microorganisms that can be directly detected by iNKT cells to the kingdom of fungi and may explain how A. fumigatus can induce severe chronic respiratory diseases in humans.

Optimization of ceragenins for prevention of bacterial colonization of hydrogel contact lenses.

PURPOSE: We provided contact lens hydrogels with an antibacterial innate immune function using nonpeptide mimics of endogenous antimicrobial peptides. METHODS: Antimicrobial peptide mimics, ceragenins, were prepared for either covalent attachment to hydrogels or for controlled elution from lenses. The lipophilicity of the ceragenins was varied incrementally to provide differing levels of association with hydrophobic domains in lenses. Ceragenin-containing lenses were challenged repeatedly with Staphylococcus aureus or Pseudomonas aeruginosa in nutrient media. Bacterial growth and biofilm formation on lenses were quantified. RESULTS: A ceragenin covalently fixed in lenses effectively inhibited S. aureus biofilm formation on lenses in 10% tryptic soy broth (approximately 3-log reduction), but did not reduce biofilm formation in 100% tryptic soy broth. Ceragenins designed to elute from lenses were incorporated at 1% relative to the dry weight of the lenses. The ceragenin with the optimal lipid content, CSA-138, prevented bacterial colonization of lenses for 15 days with P. aeruginosa and for 30 days with S. aureus (daily exchange of growth media and reinoculation with 106 CFU). Measurement of CSA-138 elution showed that concentrations of the ceragenin never exceeded 5 µg/mL in a 24-hour period and that after 4 days of elution, concentrations dropped to <0.5 µg/mL, while maintaining antibacterial activity. CONCLUSIONS: Ceragenin CSA-138 appears well suited for providing an innate immune-like function to abiotic hydrogel contact lenses for extended periods of time. Elution of even low concentrations of CSA-138 (<0.5 µg) is sufficient to eliminate inocula of 106 CFU of S. aureus and P. aeruginosa.

In vivo efficacy of a silicone‒cationic steroid antimicrobial coating to prevent implant-related infection.

Active release antimicrobial coatings for medical devices have been developed to prevent and treat biofilm implant-related infections. To date, only a handful of coatings have been put into clinical use, with limited success. In this study, a novel antimicrobial compound was incorporated into a silicone (polydimethylsiloxane or PDMS) polymer to develop a novel active release coating that addressed several limitations of current device coatings. The efficacy of this coating was optimized using an in vitro flow cells system, then translated to an animal model of a simulated Type IIIB open fracture wherein well-established biofilms were used as initial inocula. Results indicated that the novel coating was able to prevent infection in 100% (9/9) of animals that were treated with biofilms and the novel coating (treatment group). In contrast, 100% (9/9) of animals that were inoculated with biofilms and not treated with the coating (positive control), did develop infection. Nine animals were used as negative controls, i.e., those that were not treated with biofilms, and showed a rate of infection of 11% (1/9). Eight animals were treated with the novel coating only to determine its effect on host tissue. Results indicated that the novel active release coating may have significant promise for future application to prevent biofilm implant-related infections in patients.

Evolution of antiphospholipid antibody syndrome.

Antiphospholipid antibody syndrome is a very important cause of cerebral infarction, myocardial infarction, and repeated pregnancy losses in women. We present an extremely rare case of a 44-year-old man with antiphospholipid syndrome who collapsed and died suddenly. At autopsy, he was found to have both cerebral and myocardial infarction. In all young patients with cerebral infarction, myocardial infarction, pulmonary embolism, recurrent miscarriages, and unexplained low platelet count, one must consider the strong possibility of antiphospholipid antibody syndrome.

In vitro evaluation of the potential for resistance development to ceragenin CSA-13.

OBJECTIVES: Though most bacteria remain susceptible to endogenous antimicrobial peptides, specific resistance mechanisms are known. As mimics of antimicrobial peptides, ceragenins were expected to retain antibacterial activity against Gram-positive and -negative bacteria, even after prolonged exposure. Serial passaging of bacteria to a lead ceragenin, CSA-13, was performed with representative pathogenic bacteria. Ciprofloxacin, vancomycin and colistin were used as comparators. The mechanisms of resistance in Gram-negative bacteria were elucidated. METHODS: Susceptible strains of Staphylococcus aureus, Pseudomonas aeruginosa and Acinetobacter baumannii were serially exposed to CSA-13 and comparators for 30 passages. MIC values were monitored. Alterations in the Gram-negative bacterial membrane composition were characterized via mass spectrometry and the susceptibility of antimicrobial-peptide-resistant mutants to CSA-13 was evaluated. RESULTS: S. aureus became highly resistant to ciprofloxacin after <20 passages. After 30 passages, the MIC values of vancomycin and CSA-13 for S. aureus increased 9- and 3-fold, respectively. The Gram-negative organisms became highly resistant to ciprofloxacin after <20 passages. MIC values of colistin for P. aeruginosa and A. baumannii increased to ≥100 mg/L after 20 passages. MIC values of CSA-13 increased to ∼20-30 mg/L and plateaued over the course of the experiment. Bacteria resistant to CSA-13 displayed lipid A modifications that are found in organisms resistant to antimicrobial peptides. CONCLUSIONS: CSA-13 retained potent antibacterial activity against S. aureus over the course of 30 serial passages. Resistance generated in Gram-negative bacteria correlates with modifications to the outer membranes of these organisms and was not stable outside of the presence of the antimicrobial.

The majority of CD1d-sulfatide-specific T cells in human blood use a semiinvariant Vδ1 TCR.

αß T-cell lines specific for sulfatide, an abundant myelin glycosphingolipid presented by various CD1 molecules, have been previously derived from PBMCs of patients with demyelinating diseases such as multiple sclerosis (MS) but also from healthy subjects. Using an unbiased tetramer-based MACS enrichment method to enrich for rare antigen-specific cells, we confirmed the presence of CD1d-sulfatide-specific T cells in all healthy individuals examined. Surprisingly, the great majority of fresh sulfatide-specific T cells belonged to the γδ lineage. Furthermore, these cells used the Vδ1 TCR variable segment, which is uncommon in the blood but predominates in tissues such as the gut and specifically accumulates in MS lesions. Recombinant Vδ1 TCRs from different individuals were shown to bind recombinant CD1d-sulfatide complexes in a sulfatide-specific manner. These results provide the first direct demonstration of MHC-like-restricted, antigen-specific recognition by γδ TCRs. Together with previous reports, they support the notion that human Vδ1 T cells are enriched in CD1-specific T cells and suggest that the Vδ1 T-cell population that accumulates in MS lesions might be enriched in CD1-sulfatide-specific cells.