Optimizing laser cladding powder injection parameters to shape bioactive glass nano-coated zirconium oxide for biomedical application

Human body is highly sensitive and repairing often incurs pain and expenses. Strength of the materials degraded by poor joint (either weld or link). New material technology is proposed many biomaterials for repairing bone and tissue and also many bio-implantation applications. Especially bioactive material like bioactive glass is used for biomedical applications for replacement and repairing organs in human body. This research work focuses on suggesting material of S53P4 bioactive glass Nano-coated Zirconium dioxide for manufacturing artificial knee implant for fixing in human body. The substrate of Zirconium dioxide is Nano-coated with S53P4 bioactive glass by means of laser cladding process. The laser cladding process parameters were optimized by Taguchi method to enhance mechanical properties like compressive strength, wear resistance and microhardness of Zirconium dioxide implant material. The key parameters like Laser Power (1 kW, 2 kW, 3 kW and 4 kW), beam diameter (2 mm, 3 mm, 4 mm and 5 mm), powder feed rate (10 g/min, 15 g/min, 20 g/min and 25 g/min) and scanning speed (3 mm/s, 4 mm/s, 5 mm/s and 6 mm/s) were considered. The optimal parameters result the higher compressive strength and microhardness are obtained as 373 MPa and 898.37 HV0.2 and minimum wear volume is attained as 0.148 mm3 in the Nano-coated implant material.

--Eleven tips for operational researchers working with health programmes: our experience based on implementing differentiated tuberculosis care in south India

Due to the workload and lack of a critical mass of trained operational researchers within their ranks, health systems and programmes may not be able to dedicate sufficient time to conducting operational research (OR). Hence, they may need the technical support of operational researchers from research/academic organisations. Additionally, there is a knowledge gap regarding implementing differentiated tuberculosis (TB) care in programme settings. In this 'how we did it' paper, we share our experience of implementing a differentiated TB care model along with an inbuilt OR component in Tamil Nadu, a southern state in India. This was a health system initiative through a collaboration of the State TB cell with the Indian Council of Medical Research institutes and the World Health Organisation country office in India. The learnings are in the form of eleven tips: four broad principles (OR on priority areas and make it a health system initiative, implement simple and holistic ideas, embed OR within routine programme settings, aim for long-term engagement), four related to strategic planning (big team of investigators, joint leadership, decentralised decision-making, working in advance) and three about implementation planning (conducting pilots, smart use of e-tools and operational research publications at frequent intervals). These may act as a guide for other Indian states, high TB burden countries that want to implement differentiated care, and for operational researchers in providing technical assistance for strengthening implementation and conducting OR in health systems and programmes (TB or other health programmes). Following these tips may increase the chances of i) an enriching engagement, ii) policy/practice change, and iii) sustainable implementation.

Comparison of the effectiveness of red ginseng herbal mouth rinse with chlorhexidine and saline in oral cancer patients: A pilot double-blinded randomized control trial

Background

Red ginseng is an herb with many medicinal properties and aids as a mouth rinse with fewer side effects than chlorhexidine.

Aim

The study aimed to compare the efficacy of red ginseng herbal mouth rinses with those of chlorhexidine and saline in oral cancer patients.

Materials and Methods

The present pilot study was a double-blinded randomized control trial with 45 histopathologically diagnosed oral squamous cell carcinoma patients divided into three groups: two intervention groups (herbal and chlorhexidine mouth rinse) and one control group (saline). Saliva samples for each patient were collected at baseline and after 14 days of using the mouth rinses. A microbiological examination of salivary samples was done by analysing total oral bacterial load along with specific counts for Porphyromonas gingivalis and Fusobacterium nucleatum at baseline and after the usage of mouth rinse.

Statistical Analysis

The data normality was analysed using the Shapiro-Wilk test, and following the normal distribution of data, parametric tests were employed. Paired t-test and one-way analysis of variance, followed by post hoc Bonferroni test, were used for inter-group and intra-group differences.

Result

There was a significant mean difference in total colony count, Fusobacterium nucleatum, and Porphyromonas gingivalis with oral hygiene index and gingival index improvement in the red ginseng herbal mouth rinse group when compared to the chlorhexidine and saline groups.

Conclusion

In this study, red ginseng mouth rinse exhibited an increased antibacterial effect compared to chlorhexidine and saline. Hence, red ginseng mouth rinse can be used in oral cancer patients to maintain oral health, thereby improving the prognosis of these patients.

Sustainable wastewater treatment by RO and hybrid organic polyamide membrane nanofiltration system for clean environment

One of the environmental pollution is happened by the discharge of industrial wastewater that needs to be adequately filtered. Given that the effluent from the leather industry contains high levels of chromium, heavy metals, lipids, and Sulphur, it is one of the wastewater disposals that are most damaging. This experimental study focuses on reverse osmosis and hybrid organic polyimide membrane for nanofiltration for sustainable wastewater treatment. In the RO and organic polyamide Nano-porous membranes, a thin film of polyamide membrane was used for efficient filtration. Taguchi analysis optimized process parameters such as pressure, temperature, pH, and volume reduction factor. The outcome shows an 89% reduction in total wastewater hardness, an 88% reduction in sulfate, and an 89% efficiency reduction in COD. As a result, the proposed technology significantly increased filtration efficiency.

Triamcinolone Acetonide Produced by Bacillus velezensis YEBBR6 Exerts Antagonistic Activity Against Fusarium oxysporum f. sp. Cubense: A Computational Analysis

Fusarium oxysporum f. sp. cubense is one of the most severe and threatening pathogens of bananas, causing "Panama wilt" worldwide. Confrontation assay of Foc antagonistic bacterial endophyte, Bacillus velezensis YEBBR6, with the Foc and GC-MS profiling of excised agar from the zone of inhibition, led to the unveiling of secondary metabolites produced by the endophyte. To refine the probable antifungal compounds among the numerous biomolecules formed during their di-trophic interaction with the pathogen, fungal protein targets were modeled, and docking studies (AutoDock Vina module of the PyRx 0.8 server) were done with all the compounds. Triamcinolone acetonide exhibited the most excellent affinity for the protein targets among the compounds studied. It had a maximum binding affinity of 11.2 kcal/mol for XRN2 (5' → 3'). Further, the protein-ligand complex formation kinetics was done through Molecular Dynamic Simulation studies. Graphs for the RMSD, RMSF, Rg, potential energy, and SASA were generated, and the values during the simulation period suggested the stability of the biomolecule as a complex with the protein. This indicated Triamcinolone acetonide's potential ability to act as a functional disrupter of the target protein and likely an antifungal molecule. Further, the biomolecule was tested for its activity against Foc by screening in the wet lab through the poisoned plate technique, and it was found to be fully inhibitory to the growth of the pathogen at 1000 ppm.

A novel investigations on medical and non-medical mask performance with influence of marine waste microplastics (polypropylene)

The entire human race is struggling with the spread of COVID-19. Worldwide, the wearing of face masks is indispensable to prevent such spread. Despite numerous studies reporting on the fabrication of face masks and surgical masks to reduce spread and thus human deaths, this novel work is considered the marine waste of microplastics, namely Polypropylene (PP) polymer, used to fabricate non-woven fabric masks through the melt-blown process. This experimental work aims to maximize the mask's quality and minimize its fabrication cost by optimizing the melt-blown process parameters and using microplastics. The melt-blown process was used to make masks. Parameters such as extruder temperature, hot air temperature, melt flow rate, and die-to-collector distance (DCD) were investigated as independent variables. The quality of the mask was investigated in terms of bacterial filtration efficiency (BFE), particle filtration efficiency (PFE), and differential pressure. The Taguchi L16 orthogonal array and Taguchi analysis were employed for experimental design and statistical optimization, respectively. The results reveal that the higher BFE and PFE are recorded at 96.7 % and 98.6 %, respectively. The surface morphological investigation on different layers ensured the fine and uniform porosity of the layers and exhibited minimum breath resistance (a low differential pressure of 0.00152 kPa/cm²). Hence the chemically treated marine waste microplastics improved the masks' performance.

AZ63/Ti/Zr Nanocomposite for Bone-Related Biomedical Applications

Considering the unique properties of magnesium and its alloy, it has a vast demand in biomedical applications, particularly the implant material in tissue engineering due to its biodegradability. But the fixing spares must hold such implants till the end of the biodegradation of implant material. The composite technology will offer the added benefits of altering the material properties to match the requirements of the desired applications. Hence, this experimental investigation is aimed at developing a composite material for manufacturing fixing spares like a screw for implants in biomedical applications. The matrix of AZ63 magnesium alloy is reinforced with nanoparticles of zirconium (Zr) and titanium (Ti) through the stir casting-type synthesis method. The samples were prepared with equal contributions of zirconium (Zr) and titanium (Ti) nanoparticles in the total reinforcement percentage (3%, 6%, 9%, and 12%). The corrosive and tribological studies were done. In the corrosive study, the process parameters like NaCl concentration, pH value, and exposure time were varied at three levels. In the wear study, the applied Load, speed of sliding, and the distance of the slide were considered at four levels. Taguchi analysis was employed in this investigation to optimize the reinforcement and independent factors to minimize the wear and corrosive losses. The minimum wear rate was achieved in the 12% reinforced sample with the input factor levels of 60 N of load on the pin, 1 m/s of disc speed at a sliding distance was 1500 m, and the 12% reinforce samples also recorded a minimum corrosive rate of 0.0076 mm/year at the operating environment of 5% NaCl-concentrated solution with the pH value of 9 for 24 hrs of exposure. The prediction model was developed based on the experimental results.

The First Differentiated TB Care Model From India: Delays and Predictors of Losses in the Care Cascade

To reduce TB deaths in resource-limited settings, a differentiated care strategy can be used to triage patients with high risk of severe illness (i.e., those with very severe undernutrition, respiratory insufficiency, or inability to stand without support) at diagnosis and refer them for comprehensive assessment and inpatient care. Globally, there are few examples of implementing this type of strategy in routine program settings. Beginning in April 2022, the Indian state of Tamil Nadu implemented a differentiated care strategy called Tamil Nadu-Kasanoi Erappila Thittam (TN-KET) for all adults aged 15 years and older with drug-susceptible TB notified by public facilities. Before evaluating the impact on TB deaths, we sought to understand the retention and delays in the care cascade as well as predictors of losses. During April-June 2022, 14,961 TB patients were notified and 11,599 (78%) were triaged. Of those triaged, 1,509 (13%) were at high risk of severe illness; of these, 1,128 (75%) were comprehensively assessed at a nodal inpatient care facility. Of 993 confirmed as severely ill, 909 (92%) were admitted, with 8% unfavorable admission outcomes (4% deaths). Median admission duration was 4 days. From diagnosis, the median delay in triaging and admission of severely ill patients was 1 day each. Likelihood of triaging decreased for people with extrapulmonary TB, those diagnosed in high-notification districts or teaching hospitals, and those transferred out of district. Predictors of not being comprehensively assessed included: aged 25-34 years, able to stand without support, and diagnosis at a primary or secondary-level facility. Inability to stand without support was a predictor of unfavorable admission outcomes. To conclude, the first quarter of implementation suggests that TN-KET was feasible to implement but could be improved by addressing predictors of losses in the care cascade and increasing admission duration.

Environmental remediation at vegetable marketplaces through production of biowaste catalysts for biofuel generation

Large quantities of vegetable biowaste are generated at marketplaces, usually in highly populated locations. On the other hand, nearby markets, hotels, and street shops generate much cooking oil waste and dispose of them in the sewage. Environmental remediation is mandatory at these places. Hence, this experimental work concentrated on preparing biodiesel using green plant wastes and cooking oil. Biowaste catalysts were produced from vegetable wastes and biofuel generated from waste cooking oil using biowaste catalysts to support diesel demand and Environmental remediation. Other organic plant wastes such as bagasse, papaya stem, banana peduncle and moringa oleifera are used as heterogeneous catalysts of this research work. Initially, the plant wastes are independently considered for the catalyst for biodiesel production; secondary, all plant wastes are mixed to form a single catalyst and used to prepare the biodiesel. In the maximum biodiesel yield analysis, the calcination temperature, reaction temperature, methanol/oil ratio, catalyst loading and mixing speed were considered to control the biodiesel production. The results reveal that the catalyst loading of 4.5 wt% with mixed plant waste catalyst offered a maximum biodiesel yield of 95%.

INFECTIOUS COMPLICATIONS IN COMPOUND MANDIBULAR FRACTURES UNDERGOING A DELAYED SURGICAL INTERVENTION - A PROSPECTIVE OBSERVATIONAL STUDY

The aim of this prospective study was to analyse if a delay in the time from injury to definitive surgical intervention of open reduction and internal fixation (ORIF) of compound mandibular fractures predisposed to an increase in postoperative infectious complications. ORIF beyond 72 hours from injury was considered to be delayed intervention. Postoperative surgical site infections (SSI) and non-infectious complications (NIC) were recorded. The Mann-Whitney U test was used to compare the delay in ORIF with SSI. The chi squared test/Fisher's exact test was used to find the association of the infectious complication status with predetermined risk factors. Eighty-three patients underwent a delayed ORIF with a median (range) of 8 (4-19) days. SSI was documented in eight patients (9.6%) and could be managed as outpatient medical and surgical intervention. Two patients needed repeat surgical intervention due to non-union of the fracture. The median (range) time to ORIF was 6.5 (5-12) days in patients who developed SSI; the Mann-Whitney U test did not show a statistically significant association between delayed ORIF and SSI (p = 0.7). The univariate analysis did not establish a significant relationship between SSI and predetermined risk factors. The delay to definitive surgical intervention was not observed to be an independent attributing factor in postoperative infectious complications of compound mandibular fractures.

Magnetic porous Ag2O/Chitin nanostructure adsorbent for eco-friendly effective disposing azo dyes

Water treatment is as much important as it is to satisfying 11 worldwide sustainable development goals out of 17. The removal of Azo is much important as they are toxic and their existence in water, air and food can easily affect humans by triggering allergies, forming tumours etc. Azo contained Dyes Production was banned in many countries. This research aims to synthesize composite Nanorods and Nanospheres and characterize and test to remove Azo dyes from the wastewater. This research used a previously reported method to rapidly synthesize chitin magnetite nanocomposites (ChM) by co-precipitation while irradiating with ultrasound (US). Detailed structural characterization of ChM revealed a crystalline phase analogous to magnetite and spherical morphologies; extending the reaction time to 8 min yielded a "nanorod" type morphology. Both the morphologies displayed a nanoscale limit with particles averaging between 5 and 30 nm in size, resulting the superparamagnetic performance and saturation magnetization values between 45 and 58 emu/g. The nitrogen adsorption-desorption isotherms showed that the surface modification of ChMs resulted in a rise of specific surface area and pore size. Anionic azo dyes (methyl orange (MO) and reactive black 5 (RB5)) adsorption on the surface of nanocomposites was also demonstrated to be pH-dependent, with the reaction favoured for surface-modified samples at pH 4 and unmodified samples at pH 8. Adsorption capacity studies showed that molecule size effect and electrostatic attraction were two distinct adsorption processes for unmodified and modified ChMs. Chitin Magnetite nanoparticles appear to be a substitute for traditional anionic dye adsorbents. Additionally, the two key materials sources, chitin, and magnetite are inexpensive and easily accessible.

Promising strategies of circular bioeconomy using heavy metal phytoremediated plants - A critical review

Phytoremediation is an excellent method for removing harmful heavy metals from the environment since it is eco-friendly, uses little energy, and is inexpensive. However, as phytoremediated plants can turn into secondary sources for heavy metals, complete heavy metal removal from phytoremediated plants is necessary. Elimination of toxic heavy metals from phytoremediated plants should be considered with foremost care. This review highlights about important sources of heavy metal contamination, health effects caused by heavy metal contamination and technological breakthroughs of phytoremediation. This review critically emphasis about promising strategies to be engaged for absolute reutilization of heavy metals and spectacular approaches of production of commercially imperative products from phytoremediated plants through circular bioeconomy with key barriers. Thus, phytoremediation combined with circular bioeconomy can create a new platform for the eco-friendly life.

Magnetic Co/CoOx@NCNT catalysts for activation of potassium peroxymonosulfate to deteriorate phenol from wastewater

Phenols are of much toxicological and they must be effectively removed from the wastewater from industries as well as sewage treatment. Such removal demands a special and strong composite. So, this piece of research aims to activate Potassium peroxymonosulfate (PPMS) with the large surface area of magnetite nitrogen-fixed porous carbon nanotube composites (Co/CoOx@NCNT). Increases in the graphitization degree and structural control brought about by the incorporation of reduced Graphite oxide (rGO) significantly increased the catalyst activity of Co/CoOx@NCNT. It was found that PPMS activation for phenol removal by Co/CoOx@NCNT was nearly as effective as by homogeneous Co²⁺, with nearly 100% removal efficiency in 10 min. Both high reusability and high recycling of Co/CoOx@NCNT were accomplished simultaneously by proving the technology of viability in practical applications. The PPMS activation mechanism in the Co/CoOx@NCNT/PPMS system was driven by the electron transmission from contaminants to PPMS through the sp^2- hybrid carbon nanotubes and nitrogen system. The selectivity of the Co/CoOx@NCNT/PPMS system to remove diverse organic compounds was determined by batch experiments. Due to the insignificant impact of radicals reactive on pollutant breakdown, the ability to inhibit species (such as Cl^- and natural organic materials) from a minor role was significantly decreased. These results not only shed light on the process of PPMS heterogeneous activation but also provided a framework for the balanced project of highly effective nanocarbon-based catalysts for PPMS activation.

Promoting a well-dispersion of MoO3 nanoparticles on fibrous silica catalyst via one-pot synthesis for enhanced photoredox environmental pollutants efficiency

The coexistence of pharmaceutical compounds and heavy metals in the aquatic environment has resulted in complications in the treatment process and thus, causing uproar among the citizens. The radical-based photocatalysis technology has aroused as an excellent method to eliminate both heavy metal and pharmaceutical compounds in the water. Herein, reported the utilization of the microemulsion technique for the preparation of nanoporous fibrous silica-molybdenum oxide (FSMo) towards simultaneous photocatalytic abatement of hexavalent chromium (Cr(VI)) and tetracycline (TC). The FESEM analysis showed the spherical morphology of the FSMo catalyst with dendrimeric silica fiber. The synthesized FSMo catalyst exhibited narrowed bandgap, high crystallinity, and well Mo element dispersion for enhanced photo-redox of Cr(VI) and TC. Remarkably, simultaneous remediation of the Cr(VI) and TC over FSMo demonstrated superior photocatalytic efficiency, 69% and 75%, respectively, than in the individual system, possibly due to the effective separation of photoinduced charges. The introduction of the Mo element to the silica framework via microemulsion technique demonstrated better dispersion of Mo compared to the incipient wetness impregnation method and thus, yielded higher photocatalytic activity towards simultaneous removal of TC and Cr(VI). Besides, quenching experiments revealed the electrons and holes as the active species that play a dominant role in the simultaneous photo-redox of Cr(VI) and TC. Lastly, the FSMo catalyst demonstrated high stability after four continuous cycles of simultaneous photocatalysis reactions, implying its potential as a suitable material for practical wastewater treatments.

A review on synthesis methods and recent applications of nanomaterial in wastewater treatment: Challenges and future perspectives

Freshwater has been incessantly polluted by various activities such as rapid industrialization, fast growth of population and agricultural activities. Water pollution is considered as one the major threatens to human health and aquatic bodies which causes various severe harmful diseases including gastrointestinal disorders, asthma, cancer, etc. The polluted wastewater could be treated by different conventional and advanced methodologies. Amongst them, adsorption is the most utilized low cost, efficient technique to treat and remove the harmful pollutants from the wastewater. The efficiency of adsorption mainly depends on the surface properties such as functional group availability and surface area of the adsorbents used. Since various waste-based carbon derivatives are utilized as adsorbents for harmful pollutants removal; nanomaterials are employed as effective adsorbents in recent times due to its excellent surface properties. This review presents an overview of the different types of nanomaterials such as nano-particles, nanotubes, nano-sheets, nano-rods, nano-spheres, quantum dots, etc. which have been synthesized by different chemical and green synthesis methodologies using plants, microorganisms, biomolecules and carbon derivatives, metals and metal oxides and polymers. By concentrating on potential research difficulties, this study offers a new viewpoint on fundamental field of nanotechnology for wastewater treatment applications. This review paper critically reviewed the synthesis of nanomaterials more importantly green synthesis and their applications in wastewater treatment to remove the harmful pollutants such as heavy metals, dyes, pesticides, polycyclic aromatic hydrocarbons, etc.

Altered zirconium dioxide based photocatalyst for enhancement of organic pollutants degradation: A review

Heterogeneous advanced oxidation processes are a promising approach for cost-efficient removal of pollutants using semiconductors. Zirconium dioxide (ZrO₂) is an auspicious material for photocatalytic activity owning to its suitable bandgap, stability, and low cost. However, ZrO₂ suffers from fast recombination rate, and poor light harvesting ability. Nonetheless, extra modification has also shown improvements and therefore is worth investigating. The endeavour of this paper initially discusses the fundamentals with respect to reactive species, classification, and synthesis methods for ZrO₂. Furthermore, with particular consideration to stability and reusability, several additional modification approaches for ZrO₂-based photocatalysts such as doping and noble metals loading. Furthermore, the formation of heterojunctions has also been shown to boost photocatalytic activity while inhibiting charge carrier recombination. Finally, photocatalyst separation via magnetic-based photocatalysts are elucidated. As a result, ZrO₂-based photocatalysts are regarded as a promising emerging technology that warrants further development and research.

Nematicidal Property of Clindamycin and 5-hydroxy-2-methyl Furfural (HMF) from the Banana Endophyte Bacillus velezensis (YEBBR6) Against Banana Burrowing Nematode Radopholus similis

Radopholus similis is a burrowing nematode which causes banana toppling disease and is of major economic threat for the banana production. Bacterial endophyte Bacillus velezensis (YEBBR6) produce biomolecules like 5-hydroxy-2-methyl furfural (HMF) and clindamycin in during interaction with Fusarium oxysporum f.sp. cubense. Molecular modelling and docking studies were performed on Radopholus similis protein targets such as calreticulin, cathepsin S-like cysteine proteinase, β-1,4 -endoglucanase, reticulocalbin, venom allergen-like protein and serine carboxypeptidase to understand the mode of action of HMF and clindamycin against Radopholus similis. Structurally validated protein targets of R. similis were docked with biomolecules through AutoDock Vina module in PyRx 0.8 software to predict the binding energy of ligand and target protein. Among the chosen six targets, docking analysis revealed that clindamycin had the maximum binding affinity for β-1,4-endoglucanase (- 7.2 kcal/mol), reticulocalbin (- 7.5 kcal/mol) and serine carboxypeptidase (- 6.9 kcal/mol) in comparison with HMF and the nematicide, carbofuran 3G. Besides, clindamycin also had the maximum binding energy for the target sites calreticulin and venom allergen-like protein compared to the small molecule HMF. Novel molecule, clindamycin produced by B. velezensis served as a potential inhibitor of the target sites associated in interrupting the functions of β-1,4-endoglucanase, reticulocalbin, serine carboxypeptidase, calreticulin, cathepsin S-like cysteine proteinase, and venom allergen-like proteins. Besides, increased binding affinity of clindamycin with the protein target sites facilitated to explore it as a novel nematicidal molecule for the management of banana burrowing nematode R. similis. Thus, present investigation confirmed that, the small molecules clindamycin can be explored for nematicidal activity.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s12088-022-01011-2.

Changes in physiological traits and expression of key genes involved in sugar signaling pathway in rice under high temperature stress

Efficient assimilate partitioning between the source and sink organs to achieve increased grain weight is coordinated by the sugar signaling mechanism. The expression of the genes involved in sugar signaling mainly hexokinases 2 (OsHXK2), Sucrose-nonfermentation1-related protein kinase1 (OsSnRK1), trehalose-6-phosphate synthase 1 (OsTPS1) and target of rapamycin (OsTOR) under high temperature stress was examined in tolerant (NL-44) and susceptible (Vandana) varieties of rice. The photosynthetic rate, stomatal conductance, water-use efficiency, photochemical efficiency (Fv/Fm), quantum yield (ϕPSII), pollen viability, spikelet fertility and 1000 grain weight were significantly higher in NL-44 compared to Vandana under stress. The difference in the gene expression levels in the vegetative and grain-filling phases as well as between the tolerant and susceptible varieties, revealed unique pathways of sugar signaling under heat stress. In the vegetative phase, the expression of OsTOR seems to be the difference between NL-44 and Vandana for their differed heat stress tolerance whereas, in the grain-filling phase, the difference between the varieties lay in the regulation of OsHXK2. The comparative changes in the expression levels between the genes under the varying conditions indicate the sugar status in the source and sink organs that are available for translocation or remobilization.

Insights on synthesis and applications of graphene-based materials in wastewater treatment: A review

Graphene has excellent unique thermal, chemical, optical, and mechanical properties such as high thermal conductivity, high chemical stability, optical transmittance, high current density, higher surface area, etc. Due to their outstanding properties, the attention towards graphene-based materials and their derivatives in wastewater treatment has been increased in recent times. Different graphene-based materials such as graphene oxides, graphene quantum dots, graphene nanoplatelets, graphene nanoribbons and other graphene-based nanocomposites are synthesized through chemical vapor deposition, mechanical and electrochemical exfoliation of graphite. In this review, the specifics about the graphenes and their derivatives, the synthesis strategy of graphene-based materials are described. This review critically explained the applications of graphene-based materials in wastewater treatment. Graphene-based materials were utilized as adsorbents, electrodes, and photocatalysts for the efficient removal of toxic pollutants such as heavy metals, dyes, pharmaceutics, antibiotics, phenols, polycyclic aromatic hydrocarbons have been highlighted and discussed. Herein, the potential scope of graphene-based material in the field of wastewater treatment is critically reviewed. In addition, a brief perspective on future research directions and difficulties in the synthesis of graphene-based material are summarized.

Investigations on influences of MWCNT composite membranes in oil refineries waste water treatment with Taguchi route

Most of the 'oil refineries' severally pollutes the water resources by depleting their untreated waste water like cooling water, storm water and unsanitary sewage water. These wastewaters are to be treated with high care to protect the human, pebbles, plants, fish and other water animals and from harmful effects. The present study focused to treat the oil refinery wastewater by means of Multi wall carbon nanotube (MWCNT) coated Polyvinylidene Fluoride (PVDF) membrane. The main objectives are: to increases the life of filter, reduce the percolation flux and reduce the formation of antifouling in the filter by using MWCNT composite membrane in it. Different process parameters of the proposed water treatment process, like diameter of MWCNT (15 nm, 20 nm, 25 nm and 30 nm), operating pressure (3 bar, 4 bar, 5 bar and 6 bar), pH value (3, 5, 7 and 9) and temperature (25 °C, 30 °C, 35 °C and 40 °C) temperature. Taguchi statistical technique is employed for designing experiments and for optimizing the process parameters of wastewater treatment process of an oil refinery. The proposed filter for wastewater treatment exhibited appreciable performance in removal rate of Percolation flux, percentage of chemical oxygen demand removal and percentage of total carbolic rejection as 27.2 kg/m²h, 78.51% and 95.33% respectively.

Functionalization of MXene-based nanomaterials for the treatment of micropollutants in aquatic system: A review

The increased industrialization and urbanization generate a larger quantity of effluent that is discharged into the environment regularly. Based on the effluent composition produced from various industries, the number of hazardous substances such as heavy metals, hydrocarbons, volatile organic compounds, organic chemicals, microorganisms introduced into the aquatic systems vary. The conventional wastewater treatment systems do not meet the effluent standards before discharge and require a different treatment system before reuse. Adsorption is an eco-friendly technique that uses selective adsorbents to remove hazardous pollutants even at microscale levels. MXene, a 2-Dimensional nanomaterial with resplendent properties like conductivity, hydrophilicity, stability, and functionalized surface characteristics, is found as a potential candidate for pollutant removal systems. This review discusses the fabrication, characterization, and application of MXene based nanoparticles to remove many pollutants in water treatment systems. The improvement in surface properties and adsorption capacity of MXene based NPs, when modified using different modification agents, has also been discussed. Their feasibility in terms of economic and environmental aspects has been evaluated to understand their scope for practical application in large-scale industries. The challenges towards the synthesis and toxicity's importance have been discussed, with the appropriate recommendations.

A review on bioremediation approach for heavy metal detoxification and accumulation in plants

Nowadays, the accumulation of toxic heavy metals in soil and water streams is considered a serious environmental problem that causes various harmful effects on plants and animals. Phytoremediation is an effective, green, and economical bioremediation approach by which the harmful heavy metals in the contaminated ecosystem can be detoxified and accumulated in the plant. Hyperaccumulators exude molecules called transporters that carry and translocate the heavy metals present in the soil to different plant parts. The hyperaccumulator plant genes can confine higher concentrations of toxic heavy metals in their tissues. The efficiency of phytoremediation relies on various parameters such as soil properties (pH and soil type), organic matters in soil, heavy metal type, nature of rhizosphere, characteristics of rhizosphere microflora, etc. The present review comprehensively discusses the toxicity effect of heavy metals on the environment and different phytoremediation mechanisms for the transport and accumulation of heavy metals from polluted soil. This review gave comprehensive insights into plants tolerance for the higher heavy metal concentration their responses for heavy metal accumulation and the different mechanisms involved for heavy metal tolerance. The current status and the characteristic features that need to be improved in the phytoremediation process are also reviewed in detail.

Electrochemical sensing system for the analysis of emerging contaminants in aquatic environment: A review

This survey distinguishes understudied spaces of arising impurity research in wastewaters and the habitat, and suggests bearing for future checking. Thinking about the impeding effect of toxins on human wellbeing and biological system, their discovery in various media including water is fundamental. This review sums up and assesses the latest advances in the electrochemical detecting of emerging contaminants (ECs). This survey is expected to add to the advancement in electrochemical applications towards the ECs. Different electrochemical insightful procedures like Amperometry, Voltammetry has been examined in this overview. The improvement of cutting edge nanomaterial-based electrochemical sensors and biosensors for the discovery of drug compounds has accumulated monstrous consideration because of their benefits, like high affectability and selectivity, continuous observing, and convenience has been reviewed in this survey. This survey likewise features the diverse electrochemical treatment procedures accessible for the removal of ECs.

Biohardening of Banana cv. Karpooravalli (ABB; Pisang Awak) With Bacillus velezensis YEBBR6 Promotes Plant Growth and Reprograms the Innate Immune Response Against Fusarium oxysporum f.sp. cubense

Induction of innate immune response and growth promotion in banana by B. velezensis against Foc.

Investigating Influences of Synthesizing Eco-Friendly Waste-Coir-Fiber Nanofiller-Based Ramie and Abaca Natural Fiber Composite Parameters on Mechanical Properties

Clean technology-based natural fiber composite fabrication is the prime aim of this piece of research. Natural fibers highly replace metal usage in industries and automobile, marine, medical applications, and so on. Vast amounts of natural fibers are freely available in all areas. In this research, work nanofiller material such as nano form waste coir fiber is collected from used car seat. The 10 wt.% of nanofiller material is added to the preparation of natural nanocomposites (ramie and abaca fiber). Hybrid composites are fabricated with the influence of different process parameters, namely, fiber weight percentage (20 wt.%, 30 wt.%, 40 wt.%, and 50 wt.%), NaOH action % (4%, 6%, 8%, and 10%), compression pressure (9 MPa, 12 MPa, 15 MPa, and 18 MPa), and temperature (100°C, 120°C, 140°C, and 160°C). Furthermore, the strength of this hybrid composite has analyzed by conducting flexural, impact, and shore hardness tests. These tests have provided the influence of selected parameters and their effects on the results of experimental work. In the flexural analysis, 6% of NaOH action has offered maximum flexural strength of the specimens. Correspondingly in the impact test, 30 wt.% of fiber is produced higher impact strength. Finally, applying 15 Mpa of compression pressure records the maximum shore hardness.

Edge effect correction formula for superspheroids using the Debye series

Accurate quantification of the effects of nonspherical particles (e.g., ice crystals in cirrus clouds and dust aerosol particles) on the radiation budget in the atmosphere-earth coupled system requires a robust characterization of their light scattering and absorption properties. Recent studies have shown that it is feasible to compute the single-scattering properties of all sizes of arbitrary nonspherical atmospheric particles by combining the numerically exact invariant imbedding T-matrix (IITM) method and the approximate physical geometric optics method (PGOM). IITM cannot be implemented for very large-sized particles due to its tremendous demand on computational resources. While either method is usable for moderate sized particles, PGOM does not include the edge effect contributions to the extinction and absorption efficiencies. Unfortunately, we can only rigorously calculate the edge effect contributions to the extinction and absorption efficiencies for spheres and spheroids. This study develops empirical formulas for the edge effect contributions to the extinction and absorption efficiencies in the case of a special superspheroid called a superegg by modifying the formulas for the extinction and absorption efficiencies of a spheroid to account for the changes in roundness. We use the superegg edge effect correction formulas to compare the optical properties of supereggs and simple, convex particles, as an initial approximation to more complex atmospheric aerosols. This study is the first step towards quantifying the edge effect contributions to the extinction and absorption efficiencies of a wide range of natural nonspherical particles.

A critical review on relationship of CeO2-based photocatalyst towards mechanistic degradation of organic pollutant

Nanostructured photocatalysts commonly offered opportunities to solve issues scrutinized with the environmental challenges caused by steep population growth and rapid urbanization. This photocatalyst is a controllable characteristic, which can provide humans with a clean and sustainable ecosystem. Over the last decades, one of the current thriving research focuses on visible-light-driven CeO₂-based photocatalysts due to their superior characteristics, including unique fluorite-type structure, rigid framework, and facile reducing oxidizing properties of cerium's tetravalent (Ce⁴⁺) and trivalent (Ce³⁺) valence states. Notwithstanding, owing to its inherent wide energy gap, the solar energy utilization efficiency is low, which limits its application in wastewater treatment. Numerous modifications of CeO₂ have been employed to enhance photodegradation performances, such as metals and non-metals doping, adding support materials, and coupling with another semiconductor. Besides, all these doping will form a different heterojunction and show a different way of electron-hole migration. Compared to conventional heterojunction, advanced heterojunction types such as p-n heterojunction, Z-scheme, Schottky junction, and surface plasmon resonance effect exhibit superior performance for degradation owing to their excellent charge carrier separation, and the reaction occurs at a relatively higher redox potential. This review attends to providing deep insights on heterojunction mechanisms and the latest progress on photodegradation of various contaminants in wastewater using CeO₂-based photocatalysts. Hence, making the CeO₂ photocatalyst more foresee and promising to further development and research.

Mining the Genome of Bacillus velezensis VB7 (CP047587) for MAMP Genes and Non-Ribosomal Peptide Synthetase Gene Clusters Conferring Antiviral and Antifungal Activity

Chemical pesticides have an immense role in curbing the infection of plant viruses and soil-borne pathogens of high valued crops. However, the usage of chemical pesticides also contributes to the development of resistance among pathogens. Hence, attempts were made in this study to identify a suitable bacterial antagonist for managing viral and fungal pathogens infecting crop plants. Based on our earlier investigations, we identified Bacillus amyloliquefaciens VB7 as a potential antagonist for managing Sclerotinia sclerotiorum infecting carnation, tobacco streak virus infecting cotton and groundnut bud necrosis infecting tomato. Considering the multifaceted action of B. amyloliquefaciens VB7, attempts were made for whole-genome sequencing to assess the antiviral activity against tomato spotted wilt virus infecting chrysanthemum and antifungal action against Fusarium oxysporum f. sp. cubense (Foc). Genome annotation of the isolate B. amyloliquefaciens VB7 was confirmed as B. velezensis VB7 with accession number CP047587. Genome analysis revealed the presence of 9,231,928 reads with an average read length of 149 bp. Assembled genome had 1 contig, with a total length of 3,021,183 bp and an average G+C content of 46.79%. The protein-coding sequences (CDS) in the genome was 3090, transfer RNA (tRNA) genes were 85 with 29 ribosomal RNA (rRNA) genes and 21 repeat regions. The genome of B. velezensis VB7 had 506 hypothetical proteins and 2584 proteins with functional assignments. VB7 genome had the presence of flagellin protein FlaA with 987 nucleotides and translation elongation factor TU (Ef-Tu) with 1191 nucleotides. The identified ORFs were 3911 with 47.22% GC content. Non ribosomal pepide synthetase cluster (NRPS) gene clusters in the genome of VB7, coded for the anti-microbial peptides surfactin, butirosin A/butirosin B, fengycin, difficidin, bacillibactin, bacilysin, and mersacidin the Ripp lanthipeptide. Antiviral action of VB7 was confirmed by suppression of local lesion formation of TSWV in the local lesion host cowpea (Co-7). Moreover, combined application of B. velezensis VB7 with phyto-antiviral principles M. Jalapa and H. cupanioides increased shoot length, shoot diameter, number of flower buds per plant, flower diameter, and fresh weight of chrysanthemum. Further, screening for antifungal action of VB7 expressed antifungal action against Foc in vitro by producing VOC/NVOC compounds, including hexadecanoic acid, linoelaidic acid, octadecanoic acid, clindamycin, formic acid, succinamide, furanone, 4H-pyran, nonanol and oleic acid, contributing to the total suppression of Foc apart from the presence of NRPS gene clusters. Thus, our study confirmed the scope for exploring B. velezensis VB7 on a commercial scale to manage tomato spotted wilt virus, groundnut bud necrosis virus, tobacco streak virus, S. sclerotiorum, and Foc causing panama wilt of banana.

Statistical and Machine Learning Methods Applied to the Prediction of Different Tropical Rainfall Types

Predicting rain from large-scale environmental variables remains a challenging problem for climate models and it is unclear how well numerical methods can predict the true characteristics of rainfall without smaller (storm) scale information. This study explores the ability of three statistical and machine learning methods to predict 3-hourly rain occurrence and intensity at 0.5° resolution over the tropical Pacific Ocean using rain observations the Global Precipitation Measurement (GPM) satellite radar and large-scale environmental profiles of temperature and moisture from the MERRA-2 reanalysis. We also separated the rain into different types (deep convective, stratiform, and shallow convective) because of their varying kinematic and thermodynamic structures that might respond to the large-scale environment in different ways. Our expectation was that the popular machine learning methods (i.e., the neural network and random forest) would outperform a standard statistical method (a generalized linear model) because of their more flexible structures, especially in predicting the highly skewed distribution of rain rates for each rain type. However, none of the methods obviously distinguish themselves from one another and each method still has issues with predicting rain too often and not fully capturing the high end of the rain rate distributions, both of which are common problems in climate models. One implication of this study is that machine learning tools must be carefully assessed and are not necessarily applicable to solving all big data problems. Another implication is that traditional climate model approaches are not sufficient to predict extreme rain events and that other avenues need to be pursued.

Frictional Forces Produced by Three Different Ligation Methods in Two Different Types of Brackets in 0.016 Nickel-Titanium Wire: An in vitro Study

INTRODUCTION

The aim of this in vitro study was to compare the frictional forces produced by three types of ligatures (conventional elastic ligatures, unconventional elastic ligatures, and tooth-colored ligature wire) on ceramic bracket and stainless steel brackets with 0.016 nickeltitanium (NiTi) archwire in the dry state.

MATERIALS AND METHODS

Twenty each stainless steel brackets and ceramic brackets (0.022 slot central incisor brackets) were mounted on the acrylic block. This assembly was mounted on the Instron machine with the crossheads moving upward at a speed of 10 mm/min in the upper jaw of the Instron machine, one acrylic block with hook and a straight length of 0.016 NiTi wire was attached to it. This wire was ligated to brackets with three different ligation methods. In each test, the brackets were moved a distance of 4 mm, 8 mm, and 12 mm across the central space, and the load cell readings were recorded on the digital display. The difference between the readings is noted.

RESULTS

Stainless steel brackets with 0.016 NiTi archwire ligated with conventional, unconventional, and tooth-colored ligation with the movement of 4 mm, 8 mm, and 12 mm shows that the tooth-colored ligation indicating least frictional force decay. Comparison of frictional forces (in newtons) between ceramic brackets and stainless steel brackets using 0.016 NiTi wire for a movement of 12 mm shows that stainless steel bracket with tooth-colored ligation produced least frictional force compared with ceramic bracket.

CONCLUSION

Based on this study results, we can conclude that stainless steel brackets produce less frictional force compared to ceramic brackets. Similarly, tooth-colored ligatures can be preferred to reduce friction during leveling stage.

GC-MS Analysis, Molecular Docking and Pharmacokinetic Properties of Phytocompounds from Solanum torvum Unripe Fruits and Its Effect on Breast Cancer Target Protein

This study was designed to identify phytocompounds from the aqueous extract of Solanum torvum unripe fruits using GC–MS analysis against breast cancer. For this, the identified phytocompounds were subjected to perform molecular docking studies to find the effects on breast cancer target protein. Pharmacokinetic properties were also tested for the identified phytocompounds to evaluate the ADMET properties. Molecular docking studies were done using docking software PyRx, and pharmacokinetic properties of phytocompounds were evaluated using SwissADME. From the results, ten best compounds were identified from GC–MS analysis against breast cancer target protein. Of which, three compounds showed very good binding affinity with breast cancer target protein. They are ergost-25-ene-3,6-dione,5,12-dihydroxy-,(5.alpha.,12.beta.) (− 7.3 kcal/mol), aspidospermidin-17-ol,1-acetyl-16-methoxy (− 6.7 kcal/mol) and 2-(3,4-dichlorophenyl)-4-[[2-[1-methyl-2-pyrrolidinyl]ethyl amino]-6-[trichloromethyl]-s-triazine (− 6.7 kcal/mol). Further, docking study was performed for the synthetic drug doxorubicin to compare the efficiency of phytocompounds. The binding affinity of ergost-25-ene-3,6-dione,5,12-dihydroxy-,(5.alpha.,12.beta.) is higher than the synthetic drug doxorubicin (− 7.2 kcal/mol), and the binding affinity of other compounds is also very near to the drug. Hence, the present study concludes that the phytocompounds from the aqueous extract of Solanum torvum unripe fruits have the potential ability to treat breast cancer.

Central American mountains inhibit eastern North Pacific seasonal tropical cyclone activity

The eastern North Pacific (ENP) has the highest density of tropical cyclones (TCs) on earth, and yet the controls on TCs, from individual events to seasonal totals, remain poorly understood. One effect that has not been fully considered is the unique geography of the Central American mountains. Although observational studies suggest these mountains can readily fuel individual TCs through dynamical processes, here we show that these mountains indeed play the opposite role on the seasonal timescale, hindering seasonal ENP TC activity by up to 35%. We found that these mountains significantly interrupt the abundant moisture transport from the Caribbean Sea to the ENP, limiting deep convection over the open ocean area where TCs preferentially occur. This study advances our fundamental understanding of ENP TC genesis mechanisms across the weather-to-climate timescales, and also highlights the importance of topography representation in improving the ENP regional climate simulations, as well as TC seasonal predictions and future projections.

Observation on the morphological and gonadal aspects of Cladonema radiatum (Class: Hydrozoa) from Tuticorin Bay, Southeast coast of India

Studies on the hydrozoan fauna (Phylum: Cnidaria; Class: Hydrozoa) of the Indian waters during the 20th century were few in number (Nagale and Apte, 2013a, b). They originated in the early 1900s (Annandale, 1907; Ritchie, 1910, Thornely, 1916, Gravely, 1927), focussing on the taxonomy of hydroids in the 1960s along the southern coast, including Lakshadweep and Andaman Islands (Mammen, 1963, 1965a, b) and in the 1980s along the northern coast (Venugopalan Wagh, 1986). Species of the hydrozoan family Cladonematidae (Anthoathecata; Capitata) include benthic, creeping and swimming hydroids comprising four genera viz., Cladonema, Eleutheria, Staurocladia and the nomen dubium Dendronema (Schuchert, 2021). Cladonema differs from other genera of Cladonematidae by the branched tentacles either with an adhesive structure or cnidocytes and having nematocysts in oral knobs (Ghory et al., 2020 Farias et al., 2020). The taxonomy of Cladonema is uncertain and species in the genus have undergone several rounds of grouping and splitting. Gershwin Zeidler (2008) gave a detailed account of 13 putative species of Cladonema. However, Schuchert (2021) considered six species to be valid viz., C. radiatum, C. californicum, C. myersi, C. novaezelandiae, C. pacificum and C. timmsii. Studies on the genus Cladonema from Indian waters are patchy, with a brief report of its occurrence among other hydroids (Sastry and Chandramohan, 1989; Santhakumari and Nair, 1999; Arun et al., 2018). Among these records from India, C. myersi was collected from an experimental aquarium with seawater from an unknown location (Prasad, 1961). The present study documents the occurrence and describes the morphology and gonadal features of Cladonema radiatum from Tuticorin Bay, Gulf of Mannar, Southeast coast of India.

Effective removal of malachite green dye from aqueous solution in hybrid system utilizing agricultural waste as particle electrodes

A comparison study of an electrolytic, adsorption, and a novel hybrid method towards the removal of malachite green (MGD) dye from the aquatic environment utilizing agricultural biomass, Eucalyptus globulus seeds was examined. The synthesized material has been characterized by thermogravimetric analysis, SEM, FTIR, and XRD. The acid-modified biosorbent developed a microporous structure suggesting a suitable removal process of MDG. The hybrid method was carried in an indigenously designed three-phase three-dimensional electrolytic reactor with varying applied voltage (6, 9, and 12 V) with biosorbent serving as particle electrode. The hybrid method gave the highest removal rate at a voltage of 12 V, compared to other methods. Moreover, the dye removal capacity increased with increased voltage, and contact time was optimized at 15 min. The adsorption isotherm was well fitted with Freundlich isotherm and kinetic data represented pseudo-second-order. Intra particle diffusion studies suggested no interference with gradual adsorption from macropores to micropores. The removal efficiency of particles electrodes for 6, 9, and 12 V were 95, 97, and 99.8%, respectively. The higher removal of MDG towards the hybrid system may be assigned to the synergistic effect of electrolytic and adsorption systems. Regeneration studies indicated that the biosorbent can be reused up to ten times without appreciable loss of efficiency.

Bacterial endophytome-mediated resistance in banana for the management of Fusarium wilt

Banana (Musa spp.), a major cash and staple fruit crop in many parts of the world, is infected by Fusarium wilt, which contributes up to 100% yield loss and causes social consequences. Race 1 and race 2 of Panama wilt caused by Fusarium oxysporum f. sp. cubense (Foc) are prevalent worldwide and seriously affect many traditional varieties. The threat of Foc tropical race 4 (Foc TR4) is looming large in African counties. However, its incidence in India has been confined to Bihar (Katihar and Purnea), Uttar Pradesh (Faizabad), Madhya Pradesh (Burhanpur) and Gujarat (Surat). Management of Foc races by employing fungicides is often not a sustainable option as the disease spread is rapid and they negatively alter the biodiversity of beneficial ectophytes and endophytes. Besides, soil drenching with carbendazim/trifloxystrobin + tebuconazole is also not effective in suppressing the Fusarium wilt of banana. Improvement of resistance to Fusarium wilt in susceptible cultivars is being addressed through both conventional and advanced breeding approaches. However, engineering of banana endosphere with bacterial endophytes from resistant genotypes like Pisang lilly and YKM5 will induce the immune response against Foc, irrespective of races. The composition of the bacterial endomicrobiome in different banana cultivars is dominated by the phyla Proteobacteria, Bacteroidetes and Actinobacteria. The major bacterial endophytic genera antagonistic to Foc are Bacillus, Brevibacillus, Paenibacillus, Virgibacillus, Staphylococcus, Cellulomonas, Micrococcus, Corynebacterium, Kocuria spp., Paracoccus sp., Acinetobacter spp. Agrobacterium, Aneurinibacillus, Enterobacter, Klebsiella, Lysinibacillus, Micrococcus, Rhizobium, Sporolactobacillus, Pantoea, Pseudomonas, Serratia, Microbacterium, Rhodococcus, Stenotrophomonas, Pseudoxanthomonas, Luteimonas, Dokdonella, Rhodanobacter, Luteibacter, Steroidobacter, Nevskia, Aquicella, Rickettsiella, Legionella, Tatlockia and Streptomyces. These bacterial endophytes promote the growth of banana plantlets by solubilising phosphate, producing indole acetic acid and siderophores. Application of banana endophytes during the hardening phase of tissue-cultured clones serves as a shield against Foc. Hitherto, MAMP molecules of endophytes including flagellin, liposaccharides, peptidoglycans, elongation factor, cold shock proteins and hairpins induce microbe-associated molecular pattern (MAMP)-triggered immunity to suppress plant pathogens. The cascade of events associated with ISR and SAR is induced through MAPK and transcription factors including WRKY and MYC. Studies are underway to exploit the potential of antagonistic bacterial endophytes against Foc isolates and to develop an understanding of the MAMP-triggered immunity and metabolomics cross talk modulating resistance. This review explores the possibility of harnessing the potential bacterial endomicrobiome against Foc and developing nanoformulations with bacterial endophytes for increased efficacy against lethal pathogenic races of Foc infecting banana.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s13205-021-02833-5.

Groundwater vulnerability mapping using the modified DRASTIC model: the metaheuristic algorithm approach

Vulnerability assessment and mapping is a significant tool for sustainable management of the precious natural groundwater resources. DRASTIC is an extensively used index model to map groundwater vulnerable zones. However, the original DRASTIC model rates and weights used in most of the research depict the poor correlation between nitrate concentration and groundwater vulnerability index. Wilcoxon test and five population-based metaheuristic (MH) algorithms, namely, firefly algorithm (FA), invasive weed optimization (IWO), teaching learning-based optimization (TLBO), shuffled frog leaping algorithm (SFLA), and particle swarm optimization (PSO), were used to optimize the rates and weights of the DRASTIC model to improve its accuracy. The performance of all the employed metaheuristic algorithms converges to a global optimal solution at different iterations, and to choose the best algorithm for DRASTIC weights optimization, a ranking methodology was proposed. The algorithms were ranked by calculating the relative closeness of alternatives with computational speed and the number of iterations as attributes in the TOPSIS method. This study identifies FA as the outperforming algorithm among the employed for this specified weight optimization problem based on ranking. The result of the optimization model proposed depicts significant improvement in the correlation coefficient between the groundwater vulnerability index and nitrate concentration from 0.0545 for the original DRASTIC model to 0.7247 for the Wilcoxon-MH- DRASTIC. Hence, this ranking approach can be adopted when global optimal solution is found by all employed algorithms in DRASTIC weight optimization.

Efficacy of herbal alternatives in maintaining oral health in cancer patients: A systematic review

Herbal rinses possess different medicinal properties. Numerous studies have reported the usefulness of various herbal oral rinses. Few studies claimed that herbal rinses are superior to synthetic mouth rinses for certain purposes, but there appears to be a lack of sound scientific evidence to prove the efficacy of herbal rinses in controlling oral plaque in cancer patients. This review analyses the various clinical studies on herbal rinses and aims to find the safety and efficacy of red ginseng mouth rinses over other available mouth rinses in carcinoma patients. A thorough electronic search was conducted in various databases and 10 articles were included in the review based on the inclusion and exclusion criteria. The data extracted were tabulated and analyzed. The risk of bias table was drawn. Meta-analysis was not performed due to the heterogeneity of the included studies. Of the 10 clinical trials included in the review, three studies appeared to have low risk of bias. The mean follow-up period was 14 days, ranging from 7 to 21 days. The sample size in each study was reported to be between 10 and 50, except one study with 240 samples. Seven studies have reported a significant difference between the herbal mouth rinse group and the chlorhexidine group. Of all the herbal rinses, mouth rinses with ginger extracts show more efficacy over other herbal rinses and red ginseng appears to be a more safer herbal rinse. Based on the available evidence, herbal mouth rinses are comparable to synthetic mouth rinses in their anti-bacterial properties. The red ginseng with anti-bacterial, anti-inflammatory and anti-cancerous properties may be an alternative mouth rinse in cancer patients. However, further clinical trials with more samples are required for better evidence.

Evaluating the expression of GLUT-1 in oral leukoplakia

Aim:

The aim of the present study is to analyze the role of GLUT-1 in detection of early alterations occurring in oral leukoplakia. This study was to evaluate the expression of GLUT-1 in normal oral epithelium, the expression of GLUT-1 levels in the tissue samples of oral leukoplakia and to statistically compare the expression of GLUT-1 in normal epithelium and oral leukoplakia.

Materials and Methods:

The study sample comprised formalin-fixed and paraffin-embedded tissue specimens from 23 cases of histopathologically diagnosed oral leukoplakia and formalin-fixed paraffin-embedded tissue specimens from 10 cases of normal oral mucosa. Sections were mounted on glass slide coated with Aminopropyltriethoxysilane (APES; Sigma chemical co., USA) and processed for subsequent immunohistochemical study to demonstrate GLUT-1.

Results:

GLUT-1 expression in normal oral mucosa revealed weak positivity in all 10 cases (100%). The oral leukoplakia cases showed immunopositivity in all 23 cases (100%) of which 10 cases (39.14%) demonstrated focal positivity and 13 cases (60.86%) of diffuse positivity. The results were compared statistically using ANOVA test was significant at P = 0.002.

Conclusion:

The present study shows expression of GLUT-1 in leukoplakia may be used as a reliable marker to identify the high risk group for malignant transformation.

Do preoperative glycosylated hemoglobin (HbA1C) and random blood glucose levels predict wound healing complications following exodontia in type 2 diabetes mellitus patients?-a prospective observational study

BACKGROUND

Many dental surgeons consider a type 2 diabetic patient to be at higher risk for wound healing complications following exodontia. Random blood glucose (RBG) and glycosylated hemoglobin (HbA1C) values help the surgeon determine the glycemic control and assess if the patient can undergo the surgical procedure.

OBJECTIVES

The purpose of this study was to analyze if preoperative HbA1C and RBG testing could predict the risk of wound healing and infectious complications in type 2 DM patients undergoing exodontia in an office setting.

METHODS

This prospective observational study included 133 type 2 diabetic patients and age- and gender-matched non-diabetic patients undergoing exodontia. Preoperative HbA1C values and random blood glucose levels were obtained for patients in both groups. Wound healing and infectious complications and additional interventions performed were recorded.

RESULTS

Duration of diabetes ranged from 1 to 25 years. 80.5% of diabetics were treated with oral hypoglycemics. A vast majority of patients in both groups underwent extraction of only a single tooth. There was no significant difference in non-infectious complications between the two groups. The absolute risk of infectious complications in diabetics was 10.5% compared to a 6.8% risk among the control group. Age, RBG values, HbA1C, duration of DM, and number and nature of exodontia performed did not show any statistical significance.

CONCLUSION

This study observed a slight, but not statistically significant increase in the risk of infectious complications in type 2 DM patients undergoing exodontia. Surgical site infections were amenable to surgical drainage with or without oral antibiotics on an outpatient basis with favorable healing outcomes.

CLINICAL RELEVANCE

The RBG and HbA1C values were not significantly associated with risk of infectious complications. Resorting to prophylactic antibiotics and warning about possible adverse healing for routine exodontia in type 2 DM patients is unnecessary.

Chelating modified cellulose bearing pendant heterocyclic moiety for effective removal of heavy metals

Cellulose bearing pendant Schiff base with heterocyclic chelating groups (CMC-Bz) was synthesized, which were fully characterized using various instrumental techniques such as solid state carbon-13 nuclear magnetic resonance (¹³C-NMR), Fourier transform infrared (FTIR), scanning electron microscope (SEM) and energy dispersive X-ray analysis (EDX) spectra. The adsorption of toxic metals onto cellulosic material was tested in a batch mode operation. The adsorption functional factors such as pH, adsorbent dose, metal ion concentration, equilibrium time and temperature were experimentally optimized for the maximum removal of Cu(II) and Pb(II) ions. Adsorption isotherms were evaluated with Langmuir, Freundlich, Temkin and Redlich-Peterson isotherms. Kinetic parameters and equilibrium adsorption capacities were investigated for pseudo-first-order, pseudo-second-order and intra-particle diffusion models. Thermodynamic parameters and reusability were also evaluated.

Predictive Statistical Representations of Observed and Simulated Rainfall Using Generalized Linear Models

This study explores the feasibility of predicting subdaily variations and the climatological spatial patterns of rain in the tropical Pacific from atmospheric profiles using a set of generalized linear models: logistic regression for rain occurrence and gamma regression for rain amount. The prediction is separated into different rain types from TRMM satellite radar observations (stratiform, deep convective, and shallow convective) and CAM5 simulations (large-scale and convective). Environmental variables from MERRA-2 and CAM5 are used as predictors for TRMM and CAM5 rainfall, respectively. The statistical models are trained using environmental fields at 0000 UTC and rainfall from 0000 to 0600 UTC during 2003. The results are used to predict 2004 rain occurrence and rate for MERRA-2/TRMM and CAM5 separately. The first EOF profile of humidity and the second EOF profile of temperature contribute most to the prediction for both statistical models in each case. The logistic regression generally performs well for all rain types, but does better in the east Pacific compared to the west Pacific. The gamma regression produces reasonable geographical rain amount distributions but rain rate probability distributions are not predicted as well, suggesting the need for a different, higher-order model to predict rain rates. The results of this study suggest that statistical models applied to TRMM radar observations and MERRA-2 environmental parameters can predict the spatial patterns and amplitudes of tropical rainfall in the time-averaged sense. Comparing the observationally trained models to models that are trained using CAM5 simulations points to possible deficiencies in the convection parameterization used in CAM5.

Global multivariate point pattern models for rain type occurrence

We seek statistical methods to study the occurrence of multiple rain types observed by satellite on a global scale. The main scientific interests are to relate rainfall occurrence with various atmospheric state variables and to study the dependence between the occurrences of multiple types of rainfall (e.g. short-lived and intense versus long-lived and weak; the heights of the rain clouds are also considered). Commonly in point process model literature, the spatial domain is assumed to be a small, and thus planar domain. We consider the log-Gaussian Cox Process (LGCP) models on the surface of a sphere and take advantage of cross-covariance models for spatial processes on a global scale to model the stochastic intensity function of the LGCP models. We present analysis results for rainfall observations from the TRMM satellite and atmospheric state variables from MERRA-2 reanalysis data over the tropical Eastern and Western Pacific Ocean, as well as over the entire tropical and subtropical ocean regions. Statistical inference is done through Monte Carlo likelihood approximation for LGCP models. We employ covariance approximation to deal with massive data.