Ultrasound for the degradation of endocrine disrupting compounds in aqueous solution: A review on mechanisms, influence of operating parameters and cost estimation.

Availability of drinking water is one of the basic humanitarian goals but remains as a grand challenge that the world is facing today. Currently, water bodies are contaminated not only with conventional pollutants but also with numerous recalcitrant pollutants, such as PPCPs, endocrine disrupting compounds, etc. These emerging pollutants require special attention because of their toxicity to living organisms, bio-resistant and can sustain even after primary and secondary treatments of wastewater. Among different treatment technologies, sonolysis is found to be an innovative and promising technique for the treatment of emerging pollutants present in aqueous solution. Sonolysis is the use of ultrasound to enhance or alter chemical reactions by the formation of free radicals and shock waves which ultimately helps in degradation of pollutants. This review summarizes several studies in the sonochemical literature, including mechanisms of sonochemical process, physical and chemical effects of ultrasound, and the influence of several process variables such as ultrasound frequency, power density, temperature and pH of the medium on degradation performance for endocrine disrupting compounds. In addition, this review highlighted techno-economic perspectives focusing on the total cost required for translating the ultrasound-based processes on a large scale. Overall, the objective of this study is to exhibit a critical review of information available in the literature to encourage and promote future research on sonolysis for the degradation of Endocrine Disrupting Compounds (EDCs).

Adsorptive removal of dimethyl phthalate using peanut shell-derived biochar from aqueous solutions: equilibrium, kinetics, and mechanistic studies.

Rise in polymer industry and extensive use of their products leads to leaching of phthalate esters and distributed into the different matrices of the environment. This chemical group has the potential to hamper the life of living organisms and ecosystem. Thus, it is essential to develop cost-effective adsorbents capable of removing these harmful compounds from the environment. In this work, peanut hull-derived biochar was taken as the adsorbent, and DMP was selected as the model pollutant or adsorbates. The biochars of different properties were produced at three pyrolysis temperatures (i.e., 450, 550, and 650 °C) to check how temperature affected the adsorbent properties and adsorption performance. Consequently, the performance of biochars for DMP adsorption was thoroughly studied by the combination of experiments and compared with commercial activated carbon (CAC). All the adsorbents are meticulously characterized using various analytical techniques and used for adsorption DMP from aqueous solutions. The results suggested that adsorption was favoring chemisorption with multi-layered adsorption as adsorption kinetics and isotherm are in good alignment with pseudo-second-order kinetics and Freundlich isotherm, respectively. Further, thermodynamic study revealed DMP adsorption on adsorbent is physically spontaneous and endothermic. The removal efficiency order of four adsorbent was as follows: BC650 > CAC > BC550 > BC450 with maximum efficiency of 98.8% for BC650 followed by 98.6% for CAC at optimum conditions. And as it is a short carbon chain PAE, dominant mechanisms of adsorption for DMP onto porous biochar were H-bonding, π-π EDA interactions, and diffusion within the pore spaces. Therefore, this study can provide strategies for the synthesis of biochar for effectively removing DMP from aqueous solution.

Forecasting PM2.5 concentrations using statistical modeling for Bengaluru and Delhi regions.

India is home to some of the most polluted cities on the planet. The worsening air quality in most of the cities has gone to an extent of causing severe impact on human health and life expectancy. An early warning system where people are alerted well before an adverse air quality episode can go a long way in preventing exposure to harmful air conditions. Having such system can also help the government to take better mitigation and preventive measures. Forecasting systems based on machine learning are gaining importance due to their cost-effectiveness and applicability to small towns and villages, where most complex models are not feasible due to resource constraints and limited data availability. This paper presents a study of air quality forecasting by application of statistical models. Three statistical models based on autoregression (AR), moving average (MA), and autoregressive integrated moving average (ARIMA) models were applied to the datasets of PM2.5 concentrations of Delhi and Bengaluru, and forecasting was done for 1-day-ahead and 7-day-ahead time frames. All three models forecasted the PM2.5 reasonably well for Bengaluru, but the model performance deteriorated for the Delhi region. The AR, MA, and ARIMA models achieved mean absolute percentage error (MAPE) of 10.82%, 7.94%, and 8.17% respectively for forecast of 7 days and MAPE of 7.35%, 5.62%, and 5.87% for 1-day-ahead forecasts for Bengaluru. For the Delhi region, the model gave an MAPE of 27.82%, 24.62%, and 27.32% for the AR, MA, and ARIMA models respectively in the 7-day-ahead forecast, and 24.48%, 23.53%, and 23.72% respectively for 1-day-ahead forecast. The analysis showed that ARIMA model performs better in comparison to the other models but performance varies with varying concentration regimes. Study indicates that other topographical and meteorological parameters need to be incorporated to develop better models and account for the effects of these parameters in the study.

Management of complex fistula-in-ano by interception of fistula track with application of ksharasutra (IFTAK): a novel technique

Objective: Despite all the technological advances, successful management of complex fistula-in-ano is still a challenge due to recurrence and incontinence. The present study evaluates the outcomes of a novel technique, Interception of Fistula Track with Application of Ksharasutra (IFTAK) in terms of success rate and degree of incontinence. Methods: In the present prospective study, 300 patients with complex fistula-inano were treated by the IFTAK technique, whose surgical steps include: incision at the anterior or posterior midline perianal area, identification and interception of the fistulous track at the level of the external sphincter, rerouting the track (and extensions) at the site of interception, and application of a ksharasutra (medicated seton) in the proximal track (from the site of interception to the internal opening) that is laid open gradually, with the resulting wound healing with minimum scarring. The distal track is allowed to heal spontaneously. Results: There were 227 transsphincteric and 73 intersphincteric varieties of fistula with supralevator extension in 23 cases, of which 130 were recurrent fistulas, 29 had horseshoe track, while 25 had blind fistula with no cutaneous opening. The mean duration of the ksharasutra application was 8.11 ± 3.86 weeks with an overall success rate of 93.33% at the 1-year follow-up. A total of 3.67% of the cases reported with a mild impairment of continence on the Wexner incontinence scoring system. Pre- and postoperative anal manometry evaluation showed minimal reduction in median basal and squeeze pressures. Conclusion: The IFTAK technique is a minimally invasive, daycare surgical procedure for the management of complex fistula-in-ano with low recurrence and minimal sphincter damage. (AU)

Sustained release of herbal drugs using biodegradable scaffold for faster wound healing and better patient compliance.

Electrospun scaffold has been developed using biodegradable polymer and age old herbal drug for efficient wound healing patch with much better patient compliance. Positively charged smaller particle size (40 nm) of the drug has been prepared for greater penetration through epidermal barrier to enhance the wound healing activity of drug. Controlled drug release has been understood in terms of interactions between the components through spectroscopic techniques and calorimetric studies. In-vivo study using albino rats shows better wound healing efficiency of scaffold in terms of higher wound area contraction, minimum inflammation, faster epithelialization and vascularization. Cellular studies also endorse the scaffold as better biomaterial. Clinical studies also demonstrate fast healing of different type of wounds in presence of all three wound dressing materials with histological evidences. The complete biodegradation of the patch confirms its green nature of the developed patch.

A prospective study on tubercular fistula in ano and its management / Estudo prospectivo sobre a fístula anal tuberculosa e seu tratamento

Abstract Objective Tuberculosis fistula in ano, though less encountered, is an important clinical entity in developing countries like India. Diagnosis of TB fistula is a challenge despite of advances in diagnostic modalities and it depends upon both local and systemic clinical presentation. This prospective study aimed at to substantiate the importance of clinical diagnosis as well as medical management of tubercular fistula by antitubercular drugs. Methods and results 25 patients of fistula in ano suspected to be of tubercular origin underwent histopathology of fistulous tracks and an 8 week therapeutic trial of antitubercular treatment after getting an informed consent. Though biopsy showed positive evidence of tubercular pathology only in 52% cases, therapeutic trial showed improvement in local and systemic features in 23 (92%) cases. Of these 23 cases, 3 were cured after 18 months of anti tubercular treatment and 18 showed cure after 24 months of anti tubercular treatment while 2 cases withdrew from the study at 12 and 14 months respectively due to adverse drug reactions though their fistulous symptoms were relieved. Conclusion Meticulous clinical evaluation plays a vital role in diagnosis of tubercular fistula in addition to other diagnostic methods. Anti tubercular treatment is the mainstay of treatment in tubercular fistula with a minimum duration of 18-24 months owing to the recurrent and relapsing nature of disease.

Resumo Objetivo A fístula anal da tuberculose (TB), embora menos observada, constitui entidade clínica importante em países em desenvolvimento, como a Índia. O diagnóstico de fístula TB é tarefa desafiadora, apesar dos avanços nas modalidades diagnósticas; seu estabelecimento depende tanto da apresentação clínica local, como da apresentação sistêmica. Esse estudo prospectivo teve por objetivo consubstanciar a importância do diagnóstico clínico e também do tratamento clínico da fístula TB com medicamentos contra tuberculose. Métodos e resultados Foi realizado estudo histopatológico de tratos fistulosos em 25 pacientes com fístula anal com suspeita de origem tuberculosa; depois de obtido o consentimento livre e informado, esses pacientes foram submetidos a tratamento anti-tuberculose (TAT) durante 8 semanas. Embora a biópsia tenha revelado evidência positiva de patologia tuberculosa em apenas 52% dos casos, o curso terapêutico resultou em melhora nos aspectos local e sistêmico em 23 (92%) pacientes. Desses 23 casos, 3 e 18 casos estavam curados após 18 e 24 meses de TAT, respectivamente, enquanto que 2 pacientes desistiram do estudo após 12 e 14 meses, respectivamente, em decorrência de reações farmacológicas adversas, mesmo diante do alívio de seus sintomas fistulosos. Conclusão Juntamente com outros métodos diagnósticos, uma avaliação clínica meticulosa desempenha papel vital no diagnóstico da fístula TB. TAT é o principal procedimento terapêutico em pacientes com fístula TB, com duração mínima de 18-24 meses devido à natureza recorrente e recidivante da doença.

A clinical study on the efficacy of Panchavalkala cream in Vrana Shodhana w.s.r to its action on microbial load and wound infection.

BACKGROUND: The science of wound healing is advancing rapidly, particularly as a result of new therapeutic approaches. The wound healing effect of different herbal ointments have been enormous and are in wide practice these days. AIM: To evaluate the efficacy of Panchavalkala cream over wound debridement (wound infection and microbial load). MATERIALS AND METHODS: Ghanasatwa (water extract) of the individual drugs of Panchavalkala was prepared and the extract formulated as herbal ointment. This was used to treat patients of infected chronic non healing wounds. The signs and symptoms of infection were graded before and during the course of treatment. Tissue biopsy to estimate the microbial load prior to and during the course of treatment was done. RESULTS: The clinical symptoms like Slough, swelling, redness, pain, discharge, tenderness, and malodor in wounds showed statistically significant reduction following treatment. The microbial load of the wounds was also reduced significantly. CONCLUSION: In most of the cases, there was a progressive reduction in the microbial load with time, during the course of treatment indicating the efficacy of the formulation in reducing the microbial load and thus controlling infection, facilitating wound healing.

Social, economic, and resource predictors of variability in household air pollution from cookstove emissions.

We examine if social and economic factors, fuelwood availability, market and media access are associated with owning a modified stove and variation in household emissions from biomass combustion, a significant environmental and health concern in rural India. We analyze cross-sectional household socio-economic data, and PM(2.5) and particulate surface area concentration in household emissions from cookstoves (n=100). This data set combines household social and economic variables with particle emissions indexes associated with the household stove. The data are from the Foundation for Ecological Society, India, from a field study of household emissions. In our analysis, we find that less access to ready and free fuelwood and higher wealth are associated with owning a replacement/modified stove. We also find that additional kitchen ventilation is associated with a 12% reduction in particulate emissions concentration (p<0.05), after we account for the type of stove used. We did not find a significant association between replacement/modified stove on household emissions when controlling for additional ventilation. Higher wealth and education are associated with having additional ventilation. Social caste, market and media access did not have any effect on the presence of replacement or modified stoves or additional ventilation. While the data available to us does not allow an examination of direct health outcomes from emissions variations, adverse environmental and health impacts of toxic household emissions are well established elsewhere in the literature. The value of this study is in its further examination of the role of social and economic factors and available fuelwood from commons in type of stove use, and additional ventilation, and their effect on household emissions. These associations are important since the two direct routes to improving household air quality among the poor are stove type and better ventilation.

Assessing the relevance of in vitro studies in nanotoxicology by examining correlations between in vitro and in vivo data.

There is an urgent need for in vitro screening assays to evaluate nanoparticle (NP) toxicity. However, the relevance of in vitro assays is still disputable. We administered doses of TiO(2) NPs of different sizes to alveolar epithelial cells in vitro and the same NPs by intratracheal instillation in rats in vivo to examine the correlation between in vitro and in vivo responses. The correlations were based on toxicity rankings of NPs after adopting NP surface area as dose metric, and response per unit surface area as response metric. Sizes of the anatase TiO(2) NPs ranged from 3 to 100 nm. A cell-free assay for measuring reactive oxygen species (ROS) was used, and lactate dehydrogenase (LDH) release, and protein oxidation induction were the in vitro cellular assays using a rat lung Type I epithelial cell line (R3/1) following 24 h incubation. The in vivo endpoint was number of PMNs in bronchoalveolar lavage fluid (BALF) after exposure of rats to the NPs via intratracheal instillation. Slope analyses of the dose response curves shows that the in vivo and in vitro responses were well correlated. We conclude that using the approach of steepest slope analysis offers a superior method to correlate in vitro with in vivo results of NP toxicity and for ranking their toxic potency.

Role of dopant concentration, crystal phase and particle size on microbial inactivation of Cu-doped TiO2 nanoparticles.

The properties of Cu-doped TiO(2) nanoparticles (NPs) were independently controlled in a flame aerosol reactor by varying the molar feed ratios of the precursors, and by optimizing temperature and time history in the flame. The effect of the physico-chemical properties (dopant concentration, crystal phase and particle size) of Cu-doped TiO(2) nanoparticles on inactivation of Mycobacterium smegmatis (a model pathogenic bacterium) was investigated under three light conditions (complete dark, fluorescent light and UV light). The survival rate of M. smegmatis (in a minimal salt medium for 2 h) exposed to the NPs varied depending on the light irradiation conditions as well as the dopant concentrations. In dark conditions, pristine TiO(2) showed insignificant microbial inactivation, but inactivation increased with increasing dopant concentration. Under fluorescent light illumination, no significant effect was observed for TiO(2). However, when TiO(2) was doped with copper, inactivation increased with dopant concentration, reaching more than 90% (>3 wt% dopant). Enhanced microbial inactivation by TiO(2) NPs was observed only under UV light. When TiO(2) NPs were doped with copper, their inactivation potential was promoted and the UV-resistant cells were reduced by over 99%. In addition, the microbial inactivation potential of NPs was also crystal-phase-and size-dependent under all three light conditions. A lower ratio of anatase phase and smaller sizes of Cu-doped TiO(2) NPs resulted in decreased bacterial survival. The increased inactivation potential of doped TiO(2) NPs is possibly due to both enhanced photocatalytic reactions and leached copper ions.

Cu-doped TiO(2) nanoparticles enhance survival of Shewanella oneidensis MR-1 under ultraviolet light (UV) exposure.

It has been shown that photocatalytic TiO(2) nanoparticles (NPs) can be used as an efficient anti-microbial agent under UV light due to generation of reactive oxygen species (ROS), while Shewanella oneidensis MR-1 is a metal-reducing bacterium highly susceptible to UV radiation. Interestingly, we found that the presence of Cu-doped TiO(2) NPs in the cultural medium dramatically increased the survival rates (based on colony-forming unit) of strain MR-1 by over 10,000-fold (incubation without shaking) and ~200 fold (incubation with shaking) after a 2-h exposure to UV light. Gene expression results (via qPCR measurement) indicated that the DNA repair gene recA in MR-1 was significantly induced by UV exposure (indicating cellular damage under UV stress), but the influence of NPs on recA expression was not statistically evident. Plausible explanations to NP attenuation of UV stresses are: 1. TiO(2) based NPs are capable of scattering and absorbing UV light and thus create a shading effect to protect MR-1 from UV radiation; 2. more importantly, Cu-doped TiO(2) NPs can co-agglomerate with MR-1 to form large flocs that improves cells' survival against the environmental stresses. This study improves our understanding of NP ecological impacts under natural solar radiation and provides useful insights to application of photocatalytic-NPs for bacterial disinfection.

Single-step processing of copper-doped titania nanomaterials in a flame aerosol reactor.

Synthesis and characterization of long wavelength visible-light absorption Cu-doped TiO2 nanomaterials with well-controlled properties such as size, composition, morphology, and crystal phase have been demonstrated in a single-step flame aerosol reactor. This has been feasible by a detailed understanding of the formation and growth of nanoparticles in the high-temperature flame region. The important process parameters controlled were: molar feed ratios of precursors, temperature, and residence time in the high-temperature flame region. The ability to vary the crystal phase of the doped nanomaterials while keeping the primary particle size constant has been demonstrated. Results indicate that increasing the copper dopant concentration promotes an anatase to rutile phase transformation, decreased crystalline nature and primary particle size, and better suspension stability. Annealing the Cu-doped TiO2 nanoparticles increased the crystalline nature and changed the morphology from spherical to hexagonal structure. Measurements indicate a band gap narrowing by 0.8 eV (2.51 eV) was achieved at 15-wt.% copper dopant concentration compared to pristine TiO2 (3.31 eV) synthesized under the same flame conditions. The change in the crystal phase, size, and band gap is attributed to replacement of titanium atoms by copper atoms in the TiO2 crystal.

Chemical compositions and source identification of PM2.5 aerosols for estimation of a diesel source surrogate.

Exposure to traffic-related pollution during childhood has been associated with asthma exacerbation, and asthma incidence. The objective of the Cincinnati Childhood Allergy and Air Pollution Study (CCAAPS) is to determine if the development of allergic and respiratory disease is associated with exposure to diesel engine exhaust particles. A detailed receptor model analyses was undertaken by applying positive matrix factorization (PMF) and UNMIX receptor models to two PM2.5 data sets: one consisting of two carbon fractions and the other of eight temperature-resolved carbon fractions. Based on the source profiles resolved from the analyses, markers of traffic-related air pollution were estimated: the elemental carbon attributed to traffic (ECAT) and elemental carbon attributed to diesel vehicle emission (ECAD). Application of UNMIX to the two data sets generated four source factors: combustion related sulfate, traffic, metal processing and soil/crustal. The PMF application generated six source factors derived from analyzing two carbon fractions and seven factors from temperature-resolved eight carbon fractions. The source factors (with source contribution estimates by mass concentrations in parentheses) are: combustion sulfate (46.8%), vegetative burning (15.8%), secondary sulfate (12.9%), diesel vehicle emission (10.9%), metal processing (7.5%), gasoline vehicle emission (5.6%) and soil/crustal (0.7%). Diesel and gasoline vehicle emission sources were separated using eight temperature-resolved organic and elemental carbon fractions. Application of PMF to both datasets also differentiated the sulfate rich source from the vegetative burning source, which are combined in a single factor by UNMIX modeling. Calculated ECAT and ECAD values at different locations indicated that traffic source impacts depend on factors such as traffic volumes, meteorological parameters, and the mode of vehicle operation apart from the proximity of the sites to highways. The difference in ECAT and ECAD, however, was less than one standard deviation. Thus, a cost benefit consideration should be used when deciding on the benefits of an eight or two carbon approach.

Evaluation of mass and surface area concentration of particle emissions and development of emissions indices for cookstoves in rural India.

Mass-based dose parameters (for example, PM(2.5)) are most often used to characterize cookstove particulate matter emissions. Particle surface area deposition in the tracheobronchial (TB) and alveolar (A) regions of the human lung is also an important metric with respect to health effects, though very little research has investigated this dose parameter for cookstove emissions. Field sampling of cookstove emissions was performed in two regions of rural India, wherein PM(2.5), particulate surface area concentration in both TB and A regions, and carbon monoxide (CO) were measured in 120 households and two roadside restaurants. Novel indices were developed and used to compare the emissions and efficiency of several types of household and commercial cookstoves, as well as to compare mass-based (PM(2.5)) and surface area-based measurements of particle concentration. The correlation between PM(2.5) and surface area concentration was low to moderate: Pearson's correlation coefficient (R) for PM(2.5) vs surface area concentration in TB region is 0.38 and for PM(2.5) vs surface area concentration in A region is 0.47, indicating that PM(2.5) is not a sufficient proxy for particle surface area concentration. The indices will also help communicate results of cookstove studies to decision makers more easily.

Role of Surface Area, Primary Particle Size, and Crystal Phase on Titanium Dioxide Nanoparticle Dispersion Properties.

Characterizing nanoparticle dispersions and understanding the effect of parameters that alter dispersion properties are important for both environmental applications and toxicity investigations. The role of particle surface area, primary particle size, and crystal phase on TiO2 nanoparticle dispersion properties is reported. Hydrodynamic size, zeta potential, and isoelectric point (IEP) of ten laboratory synthesized TiO2 samples, and one commercial Degussa TiO2 sample (P25) dispersed in different solutions were characterized. Solution ionic strength and pH affect titania dispersion properties. The effect of monovalent (NaCl) and divalent (MgCl2) inert electrolytes on dispersion properties was quantified through their contribution to ionic strength. Increasing titania particle surface area resulted in a decrease in solution pH. At fixed pH, increasing the particle surface area enhanced the collision frequency between particles and led to a higher degree of agglomeration. In addition to the synthesis method, TiO2 isoelectric point was found to be dependent on particle size. As anatase TiO2 primary particle size increased from 6 nm to 104 nm, its IEP decreased from 6.0 to 3.8 that also results in changes in dispersion zeta potential and hydrodynamic size. In contrast to particle size, TiO2 nanoparticle IEP was found to be insensitive to particle crystal structure.

Bacterial responses to Cu-doped TiO(2) nanoparticles.

The toxicity of Cu-doped TiO(2) nanoparticles (NPs, 20nm), synthesized by a flame aerosol reactor, to Mycobacterium smegmatis and Shewanella oneidensis MR-1, is the primary focus of this study. Both doped and non-doped TiO(2) NPs (20nm) tended to agglomerate in the medium solution, and therefore did not penetrate into the cell and damage cellular structures. TiO(2) particles (<100mg/L) did not apparently interfere with the growth of the two species in aqueous cultures. Cu-doped TiO(2) NPs (20mg/L) significantly reduced the M. smegmatis growth rate by three fold, but did not affect S. oneidensis MR-1 growth. The toxicity of Cu-doped TiO(2) NPs was driven by the release of Cu(2+) from the parent NPs. Compared to equivalent amounts of Cu(2+), Cu-doped TiO(2) NPs exhibited higher levels of toxicity to M. smegmatis (P-value<0.1). Addition of EDTA in the culture appeared to significantly decrease the anti-mycobacterium activity of Cu-doped TiO(2) NPs. S. oneidensis MR-1 produced a large amount of extracellular polymeric substances (EPS) under NP stress, especially extracellular protein. Therefore, S. oneidensis MR-1 was able to tolerate a much higher concentration of Cu(2+) or Cu-doped TiO(2) NPs. S. oneidensis MR-1 also adsorbed NPs on cell surface and enzymatically reduced ionic copper in culture medium with a remediating rate of 61microg/(liter x OD(600) x hour) during its early exponential growth phase. Since the metal reducing Shewanella species can efficiently "clean" metal-oxide NPs, the activities of such environmentally relevant bacteria may be an important consideration for evaluating the ecological risk of metal-oxide NPs.

Nanoscale size effects on uranium(VI) adsorption to hematite.

U(VI) adsorption on aerosol-synthesized hematite particles ranging in size from 12 to 125 nm was studied to explore nanoscale size effects on uranium adsorption. Adsorption on 70 nm aqueous-synthesized particles was also investigated to examine the effect of the synthesis method on reactivity. Equilibrium adsorption was measured over pH 3-11 at two U(VI) loadings. Surface complexation modeling, combined with adjustment of adsorption equilibrium constants to be independent of site density and surface area, provided a quantitative reaction-based framework for evaluating adsorption affinity and capacity. Among the aerosol-synthesized particles, the adsorption affinity decreased as the particle size increased from 12 to 125 nm with similar intermediate affinities for 30 and 50 nm particles. X-ray absorption fine structure spectroscopy measurements suggest that the differences in adsorption affinity and capacity are not the result of substantially different coordination environments of adsorbed U(VI).