Effect of compaction on bisulfide diffusive transport through MX-80 bentonite

Canada's deep geological repository (DGR) design includes an engineered barrier system where highly compacted bentonite (HCB) surrounds the copper-coated used fuel containers (UFCs). Microbial-influenced corrosion is a potential threat to long-term integrity of UFC as bisulfide (HS-) may be produced by microbial activities under anaerobic conditions and transported via diffusion through the HCB to reach the UFC surface, resulting in corrosion of copper. Therefore, understanding HS- transport mechanisms through HCB is critical for accurate prediction of copper corrosion allowance. This study investigated HS- transport behaviour through MX-80 bentonite at dry densities 1070-1615 kg m-3 by performing through-diffusion experiments. Following HS- diffusion, bromide (Br-) diffusion and Raman spectroscopy analyses were performed to explore possible physical or mineralogical alterations of bentonite caused by interacting with HS-. In addition, accessible porosity ε was estimated using extended Archie's law. Effective diffusion coefficient of HS- was found 2.5 × 10-12 m2 s-1 and 5.0× 10-12 m2 s-1 for dry densities 1330 and 1070 kg m-3, respectively. No HS- breakthrough was observed for highly compacted bentonite (1535-1615 kg m-3) over the experimental timeframe (170 days). Raman spectroscopy results revealed that HS- reacted with iron in bentonite and precipitated as mackinawite and, therefore, it was immobilized. Finally, results of this study imply that HS- transport towards UFC will be highly controlled by the available iron content and dry density of the buffer material.

Expression of stathmin in oral squamous cell carcinoma and its correlation with tumour proliferation

Background

Stathmin is a member of microtubule-associated protein. Inhibition of Stathmin expression can interfere with tumour progression and also alter the sensitivity of tumour cells to microtubule-targeting agents. Thus, it could be a potential therapeutic target for planning new treatment strategies.

Objective

To study expression of Stathmin in different histological grades of oral squamous cell carcinoma (OSCC) and its correlation with Ki67 index.

Materials and Methods

This study was an observational retrospective and prospective study conducted during a period of two and half years from January 2015 to June 2017 at ESI-PGIMSR Maniktala, Kolkata where 52 cases of OSCC were studied. Haematoxylin and eosin sections were reviewed and representative paraffin blocks were selected. Immunostains were performed using antibody clones for Stathmin and Ki67. For Stathmin scoring, Segersten scoring system was applied. Statistical analysis was done by Graph Pad Prism using Krusher Wallis Test and one-way ANOVA test. Spearman's coefficient was used to establish corelation between Ki 67 and Stathmin overexpression.

Results

In this study, it is found that strong Stathmin expression score (4-9) was detected mostly (82.35%) in moderately differentiated (MD) OSCC and poorly differentiated (PD) OSCC (100%), whereas in contrast, 60% of well-differentiated OSCC showed negative-to-weak Stathmin score (1-3). Mean Ki67-labelling index for well-differentiated carcinoma was 32.37%, for moderately differentiated carcinoma was 60.89, and poorly differentiated carcinoma was 86.15%, which demonstrated increased tumour cell proliferation with progression of histological grades of OSCC.

Conclusion

Stathmin expression was higher in MD OSCC to PD OSCC compared to well-differentiated carcinoma and its overexpression was significantly correlated with Ki67 index. Thus, Stathmin is overexpressed in higher grades and is correlated with high proliferation of tumour with a potential role as therapeutic target.

A comparative study between ultrasonography guided classical interscalene block plus superficial cervical plexus block versus low approach interscalene block plus superficial cervical plexus block in lateral one-third of clavicle and proximal humerus surgery

Background: Classical interscalene approach of brachial plexus block with superficial cervical plexus block has become the anesthetic technique of choice in the upper arm, shoulder, and clavicle surgery but there is high risk of complications and sparing of C8-T1 nerve roots. Here, we used low approach of interscalene block (ISB) with superficial cervical plexus block for lateral one-third of clavicle and proximal humerus surgeries. Previously, none of the study compare ultrasonography (USG) guided low ISB (LISB) to the conventional approach for lateral one-third of clavicle and proximal humerus surgeries. Aims and Objectives: The aim of the study was to compare onset, duration, density of sensory-motor block, and severity of complication between ISB and LISB with superficial cervical plexus block. Materials and Methods: Patients with fracture of lateral end of clavicle and proximal humerus of 18–60 years of 324, American Society of Anesthesiologists I and II patients, were randomly assigned into two groups ISBS and LISB with superficial cervical plexus block (LISBS) to find out the difference in density of sensory-motor blockade associated with any complications between two groups. Results: The degree of the ulnar block after 5 and 15 min was found to be 2.8±2.6 and 1.1±1.8 in LISBS, respectively, for ISBS 3.0±1.5 and 1.8±2.0, respectively, based on a ten-point scale. After 15 min, motor block occurred in the median nerve in 151 patients out of 162 (92.8%), and in all of the other three nerves in all 162 patients. Horner syndrome and hoarseness were less frequent in LISB with superficial cervical plexus block patients than in ISB with superficial cervical plexus block patients (P=0.0009 and 0.003, respectively) which was statistically significant. Conclusion: The present study confirmed the achievement of an appropriate sensory and motor block in the lateral one-third of clavicle with proximal humerus surgery, including the ulnar nerve with no complications than ISB.

Spatial distribution of trace elements in surface sediments of Hooghly (Ganges) river estuary in West Bengal, India

The spatial distribution of trace elements in surface sediments of the Hooghly estuary was studied over the monsoons in 2014-2017. As, Cd, Ni, Pb and U were two- to sixteen-fold the crust means with increasing levels toward the estuary, with Ni peak during the post-monsoon. Pearson's correlation matrix, cluster analysis, enrichment factors and pollution index revealed the anthropic source and association of trace elements with Fe, Mn and Al and of Pb with U. Geoaccumulation index revealed for Ni an extremely contaminated situation at the estuary water during monsoon and for Cd a heavily contaminated situation at freshwater location. The potential contamination index was >6; thus, sediments were very severely contaminated by As, Cd and Ni with worst situation for As and Cd at fresh and brackish water and during post-monsoon. The overall ecological risk was severe, 300≤RI<600 at all sites and seasons, especially after the monsoon, at fluvial and brackish locations.

Quantum Spin Torque Driven Transmutation of an Antiferromagnetic Mott Insulator

The standard model of spin-transfer torque (STT) in antiferromagnetic spintronics considers the exchange of angular momentum between quantum spins of flowing electrons and noncollinear-to-them localized spins treated as classical vectors. These vectors are assumed to realize Néel order in equilibrium, ↑↓⋯↑↓, and their STT-driven dynamics is described by the Landau-Lifshitz-Gilbert (LLG) equation. However, many experimentally employed materials (such as archetypal NiO) are strongly electron-correlated antiferromagnetic Mott insulators (AFMIs) whose localized spins form a ground state quite different from the unentangled Néel state |↑↓⋯↑↓⟩. The true ground state is entangled by quantum spin fluctuations, leading to the expectation value of all localized spins being zero, so that LLG dynamics of classical vectors of fixed length rotating due to STT cannot even be initiated. Instead, a fully quantum treatment of both conduction electrons and localized spins is necessary to capture the exchange of spin angular momentum between them, denoted as quantum STT. We use a recently developed time-dependent density matrix renormalization group approach to quantum STT to predict how injection of a spin-polarized current pulse into a normal metal layer coupled to an AFMI overlayer via exchange interaction and possibly small interlayer hopping-mimicking, e.g., topological-insulator/NiO bilayer employed experimentally-will induce a nonzero expectation value of AFMI localized spins. This new nonequilibrium phase is a spatially inhomogeneous ferromagnet with a zigzag profile of localized spins. The total spin absorbed by AFMI increases with electron-electron repulsion in AFMIs, as well as when the two layers do not exchange any charge.

Expression of Biomarkers Estrogen Receptor, Progesterone Receptor, HER2 in Primary Breast Tumour and Synchronous Metastatic Axillary Lymph Node

Introduction: Estrogen Receptor (ER), Progesterone Receptor (PR), Human Epidermal growth factor Receptor 2 (HER2) status are routinely used to guide treatment decision for breast cancer. Treatment protocol in breast cancer is currently based on biomarker characteristic of primary tumour. But this biomarker status may change as the tumour progresses from primary to synchronous metastatic lymph node. Hence, it is important to know the biomarker status of these synchronous metastatic lymph nodes as it may serve as an important tool to guide management, evaluate prognosis and to anticipate the possibility of recurrent risk of primary invasive breast cancer. Aim: To study the expression of ER, PR, HER2 status in primary breast carcinoma and synchronous metastatic lymph node and to evaluate concordance and discordance between them. Materials and Methods: This study was observational, retrospective and prospective study conducted over a period of one and half years from February 2015 to October 2016 at ESI-PGIMSR, Maniktala, Kolkata, India, where 50 cases of breast carcinoma with positive axillary lymph node metastasis were studied. Haematoxylin and Eosin (H&E) sections were reviewed and representative paraffin blocks were selected. Immunostains were performed and scoring was done following standard protocols. Standard statistical methods were applied for analysis of data using chi-square test and kappa statistics and data was analysed using Statistical Package for the Social Sciences (SPSS) version 6.1.3 software. Results: Out of 50 cases the mean age of the patients was 50.56±10.5 years. Amongst ER and PR status, 24 out of 50 (48%) and 18 out of 50 (36%) were ER and PR positive respectively. HER2 positive cases were 48% i.e., 24 out of 50 cases. The overall discordance rates of ER, PR and HER2 was found to be 10%, 8%, 18%, respectively. The discordance rates of ER positive and ER negative cases were 4.2% and 15.4%, respectively. The discordance rates of PR positive and PR negative cases were 5.6% and 9.4% respectively, whereas 29.2% of HER2 positive cases were discordant in lymph node metastases. Conclusion: There was discordance between ER, PR, HER2 status of primary tumour and metastatic lymph node. Hence, assessment of these biomarker status in axillary lymph node metastases may be considered along with primary tumour in breast carcinoma work-up.

Removal of As(V), Cr(VI) and Cu(II) using novel amine functionalized composite nanofiltration membranes fabricated on ceramic tubular substrate

Novel amine functionalized composite membranes were prepared over tubular ceramic substrate using facile dip-coating and cross-flow filtration approach. The two fabricated membranes, P-60S and P-60S-EDTA with polyethyleneimine (PEI) and EDTA-modified PEI as functional layers respectively, were characterized in terms of EDX, FTIR, XPS, FESEM, AFM and contact angle analyses which confirmed their stable physical and chemical structure for use in high pressure application. Clean water permeability and MWCO study revealed the superior permeability and rejection efficiency of the P-60S-EDTA compared to the P-60S membrane. Incorporation of bulky EDTA molecules in the membrane functional layer simultaneously decreased pore size and increased membrane hydrophilicity. The removal of As(V), Cr(VI) and Cu(II) heavy metals by both membranes were found to be highly pH dependent and overall rejection improved in case of P-60S-EDTA membrane [99.82% for Cu(II), 96.75% for As(V) and 97.22% for Cr(VI)]. Interestingly, rejection of As(V) and Cr(VI) was significantly improved in presence of Cu(II) due to volume resistance provided by EDTA-Cu(II) complex towards the passage of other heavy metal ions. Excellent stability of P-60S-EDTA membrane in continuous operation of 36 h in both ideal and practical water environment suggests its promising application in real field heavy metal contaminated waste water treatment.

Production of lipid-containing microalgal biomass and simultaneous removal of nitrate and phosphate from synthetic wastewater

The major concerns of the modern society such as increasing population, climate change and economic development are imposing continuous stress on water and energy resources. The present work deals with the cultivation of green algae Desmodesmus abundans for optimum biomass productivity and lipid content as well as simultaneous removal of nitrate and phosphate from synthetic wastewater. The algal biomass is characterized by ultimate analysis, scanning electron microscopic analysis and thermogravimetric analysis. The effect of time, inoculum concentration and nitrate concentration on four responses (biomass productivity, lipid content, removal of nitrate and removal of phosphate) are studied by response surface methodology using central composite design. The quadratic models are found to be suitable for each response. At optimized experimental conditions, the algae showed biomass productivity of 46.96 mg L^-1 day^-1, lipid content of 16.23%, nitrate removal of 86.64% and phosphate removal of 87.52% after 27 days, when the initial inoculum concentration was 6% and nitrate concentration was 1.25 g L^-1.

Correction to: Trace elements in surface sediments of the Hooghly (Ganges) estuary: distribution and contamination risk assessment

Unfortunately, in the original publication of the article, Prof. Yong Sik Ok's affiliation was incorrectly published. The author's affiliation is as follows.

Seasonal assessment of trace element contamination in intertidal sediments of the meso-macrotidal Hooghly (Ganges) River Estuary with a note on mercury speciation

The spatial and seasonal distribution of trace elements (TEs) (n=16) in surficial sediment were examined along the Hooghly River Estuary (~175km), India. A synchronous elevation of majority of TEs concentration (mgkg^-1) was encountered during monsoon with the following descending order: Al (67070); Fe (31300); Cd (5.73); Cr (71.17); Cu (29.09); Mn (658.74); Ni (35.89). An overall low and homogeneous concentration of total Hg (T_Hg=17.85±4.98ngg^-1) was recorded in which methyl mercury (MeHg) shared minor fraction (8-31%) of the T_Hg. Sediment pollution indices, viz. geo-accumulation index (I_geo) and enrichment factor (EF) for Cd (I_geo=1.92-3.67; EF=13.83-31.17) and Ba (I_geo=0.79-5.03; EF=5.79-108.94) suggested high contamination from anthropogenic sources. From factor analysis it was inferred that TEs primarily originated from lithogenic sources. This study would provide the latest benchmark of TE pollution along with the first record of MeHg in this fluvial system which recommends reliable monitoring to safeguard geochemical health of this stressed environment.

Pollution evaluation of total and acid-leachable trace elements in surface sediments of Hooghly River Estuary and Sundarban Mangrove Wetland (India)

The present work investigated the spatial distribution and ecological risk assessment of total and mild acid-leachable trace elements in surface sediments (top 0-10 cm; grain size ≤ 63 μm) along the Hooghly (Ganges) River Estuary and Sundarban Mangrove Wetland, India. The trace elements, analyzed by ICPMS, showed wide range of variations with the following descending order (mean values expressed in milligrams per kilogram): Fe (25,050 ± 4918) > Al (16,992 ± 4172) > Mn (517 ± 102) > Zn (53 ± 18) > Cu (33 ± 11) > Cr (29 ± 7) > Ni (27 ± 6) > Pb (14 ± 3) > As (5 ± 1) > Se (0.37 ± 0.10) > Cd (0.17 ± 0.13) > Ag (0.16 ± 0.19) > Hg (0.05 ± 0.10). In the acid-leachable fraction, Cd (92%) is dominated followed by Pb (81%), Mn (77%), Cu (70%), and Se (58%) indicating their high mobility, imposing negative impact on the adjacent benthos. The sediment pollution indices (both enrichment factor and contamination factor) suggested severe pollution by Ag at the sampling site Sajnekhali, a wildlife sanctuary in Sundarban. The mean probable effect level quotient indicated that surface sediments in the vicinity of the studied region have 21% probability of toxicity to biota. The result of multivariate analyses affirms lithogenic sources (e.g., weathering parent rocks, dry deposition) for As, Pb, Cr, Cu, and Ni, whereas Cd and Hg originated from anthropogenic activities (such as urban and industrial activities). Both human-induced stresses and natural processes controlled trace element accumulation and distribution in the estuarine system, and remedial measures are required to mitigate the potential impacts of these hazardous trace elements.

Arsenic in groundwater of West Bengal, India: A review of human health risks and assessment of possible intervention options

This paper reviews how active research in West Bengal has unmasked the endemic arsenism that has detrimental effects on the health of millions of people and their offspring. It documents how the pathways of exposure to this toxin/poison have been greatly expanded through intensive application of groundwater in agriculture in the region within the Green Revolution framework. A goal of this paper is to compare and contrast the similarities and differences in arsenic occurrence in West Bengal with those of other parts of the world and assess the unique socio-cultural factors that determine the risks of exposure to arsenic in local groundwater. Successful intervention options are also critically reviewed with emphasis on integrative strategies that ensure safe water to the population, proper nutrition, and effective ways to reduce the transfer of arsenic from soil to crops. While no universal model may be suited for the vast areas of the world affected with by natural contamination of groundwater with arsenic, we have emphasized community-specific sustainable options that can be adapted. Disseminating scientifically correct information among the population coupled with increased community level participation and education are recognized as necessary adjuncts for an engineering intervention to be successful and sustainable.

Recent advancements and new perspectives in animal models for Neurocysticercosis immunopathogenesis

Neurocysticercosis (NCC), one of the most common parasitic diseases of the central nervous system, is caused by Taenia solium. This parasite involves two hosts, intermediate hosts (pig and human) and a definitive host (human) and has various stages in its complex life cycle (eggs, oncosphere, cysticerci and adult tapeworm). Hence, developing an animal model for T. solium that mimics its natural course of infection is quite challenging. We have reviewed here the animal models frequently used to study immunopathogenesis of cysticercosis and also discussed their usefulness for NCC studies. We found that researchers have used mice, rats, guinea pigs, dogs, cats and pigs as models for this disease with varying degrees of success. Mice and rats models have been utilized extensively for immunopathogenesis studies due to their relative ease of handling and abundance of commercially available reagents to study these small animal models. These models have provided some very exciting results for in-depth understanding of the disease. Of late, the experimentally/naturally infected swine model is turning out to be the best animal model as the disease progression closely resembles human infection in pigs. However, handling large experimental animals has its own challenges and limitations.

Trace elements in surface sediments of the Hooghly (Ganges) estuary: distribution and contamination risk assessment

Our objective was to evaluate distribution and accumulation of trace elements (TEs) in surface sediments along the Hooghly (Ganges) River Estuary, India, and to assess the potential risk with view to human health. The TE concentrations (mg kg^-1 dry weight) exhibited a wide range in the following order: Al (31.801 ± 15.943) > Fe (23.337 ± 7584) > Mn (461 ± 147) > S (381 ± 235) > Zn (54 ± 18) > V (43 ± 14) > Cr (39 ± 15) > As (34 ± 15) > Cu (27 ± 11) > Ni (24 ± 9) > Se (17 ± 8) > Co (11 ± 3) > Mo (10 ± 2) > Hg (0.02 ± 0.01). Clay, silt, iron, manganese and sulphur were important for the accumulation of TE in the sediments as confirmed by factor analysis and Pearson correlation. The accumulation and dispersal of TEs were most likely to be governed by both tide-induced processes and anthropogenic inputs from point and non-point sources. Enrichment factor analysis and geoaccumulation index revealed serious contamination of the sediments with Se and As, while comparing the consensus-based sediment quality guidelines (SQGs), adverse biological effects to benthic fauna might be caused by As, Cu, Ni and Cr. This investigation may serve as a model study and recommends continuous monitoring of As, Se, Cu, Ni and Cr to ascertain that SQGs with respect to acceptable levels of TEs to safeguard geochemical health and ecology in the vicinity of this estuary.

Detection and Significance of Human Epidermal Growth Factor Receptor 2 Expression in Gastric Adenocarcinoma

Background:

Human epidermal growth factor receptor 2 (HER2) is involved in the pathogenesis of several types of cancer, including gastric cancer. Overexpression of HER2 is noted in 10%–22.8% of gastric adenocarcinoma and its identification is of immense importance for management by targeted drugs. Detection of HER2 expression in gastric malignancies has not been undertaken previously in the local population.

Objective:

To ascertain HER2 immunohistochemical expression in gastric adenocarcinoma and its relationship with the anatomic location and histomorphology.

Materials and Methods:

A total of 47 cases of gastric adenocarcinoma diagnosed over 2 years constituted the study group. Clinical history, type of operation, gross morphology, and hematoxylin and eosin (H and E) stained sections were reviewed. Two paraffin blocks were selected, immunostain was performed using rabbit monoclonal HER2 antibody and Hoffmann scoring system was applied.

Results:

Most of gastric carcinomas occurred in male (42 cases), having a mean age of 53.6 years. A total of eight cases (17.1%) had expressed a score of 3+ HER2 positivity. All positivity was noted in intestinal type according to Lauren classification (25%) and none in diffuse type. All HER2 score of 3+ was noted in histological grade of well and moderately differentiated adenocarcinoma. Score 2+ was noted in seven cases, among them, only two were poorly differentiated gastric adenocarcinoma.

Conclusion:

HER2 overexpression was noticeably associated with an intestinal subtype, and well and moderately differentiated adenocarcinomas. Such cases of gastric adenocarcinoma are considered for targeted therapy with trastuzumab in the local population.

Direct experimental observation of salt induced aspect ratio tunable PFPT silver-nanowire formation: SERS-based ppt level Hg2+ sensing from ground water

A common salt induced aspect ratio tunable PFPT silver nanowire synthesis with a plausible explanation based on real-time direct experimental observation finds application as a potential assay for ppt level Hg(ii) sensing from ground water.

Assessment of trace metal contamination level and toxicity in sediments from coastal regions of West Bengal, eastern part of India

The work investigated concentration of trace metals in surface sediments (0-10 cm; < 63 μm grain size) from 15 sampling sites of diverse environmental stresses covering Hugli River Estuary (HRE) and Sundarban Mangrove Wetland (SMW), eastern coastal part of India. The trace metal concentrations in sediments exhibited an overall decreasing trend as follows: Cr (21.2-60.9)>Cu (11.60-102.47)>Ni (19.10-52.60)>Pb (7.09-183.88)>As (4.41-11.46)>Cd (0.02-4.4)>Ag (0.02-0.87). Both the geo-accumulation index (Igeo) and contamination factor (CF) values revealed significant pollution by Ag, Cd and Pb at Nurpur of HRE. Potential Ecological Risk Index (RI) (61.21 ± 112.40) showed wide range of variations from low (19.76) to serious (463.20) ecological risk. A positive significant correlation was found between metals and organic carbon in sediments. The ecological risk associated with the trace metals in sediment was considered on the consensus based Sediment Quality Guidelines (SQGs). The work suggests that the trace metals present in sediments posed adverse effects on the sediment-dwelling organisms.

Human-induced ecological changes in western part of Indian Sundarban megadelta: A threat to ecosystem stability

The study first illustrates a comprehensive account of large-scale changes in water quality characteristics and plankton community structure due to occurrence of Annual Gangasagar Festival (AGF) at Sagar Island, western part of Indian Sundarban megadelta for 3-year duration (2012-2014; n=36). About 1 million pilgrims across India converge to take their holy bath at the confluence of Hooghly estuary and Bay of Bengal during January each year. This mass scale bathing results negative impact on water quality due to high turbidity (14.02 ± 2.34 NTU) coupled with low chlorophyll a (1.02 ± 0.21 mg m(-3)) and dissolved oxygen (3.94 ± 1.1 mg l(-1)). A marked decrease in abundance (from 4140 to 2997 cells l(-1)) and diversity (H'=2.72-1.33) of phytoplankton and microzooplankton tintinnids (from 450 to 328 ind l(-1); H'=4.31-2.21) was recorded. The festival acts as multiple stressors modifying natural functions of the delta. Sound and sustainable management strategies are to be adopted to maintain the protection-usage equilibrium.

Synthesis of bentonite clay based hydroxyapatite nanocomposites cross-linked by glutaraldehyde and optimization by response surface methodology for lead removal from aqueous solution

The synthesis and characterization of novel BT–HAp nanocomposites is described and their adsorption of lead from aqueous solution followed by RSM optimization is demonstrated.

Hyper-Rayleigh scattering from gold nanoparticles: effect of size and shape

We report hyper-Rayleigh scattering (HRS) properties of gold nanoparticles (GNPs) of five different shapes, quasi-spherical (∼10 and ∼20 nm diameter), rod (aspect ratio ∼2), and branched shapes, tetrapod, flower and star with 800 nm, 150 fs laser excitation. Using ∼10 nm spherical GNPs as reference, the first hyperpolarizability (β) values were calculated for all other shapes. Star and flower shaped GNPs have the highest hyperpolarizability (∼130 and ∼52 times higher, respectively), while rod and tetrapod shaped GNPs only have modest enhancement (∼7 times), which is similar to ∼20 nm size quasi-spherical particles. These enhancements are attributed to reduced symmetry as well as the presence of sharp tips on GNP surface. When the β values are normalized with respect to the number of atoms per particle, the flower and star shaped GNPs still have the highest hyperpolarizability values. The polar plots of vertically polarized HRS signal as a function of the angle of polarization of the incoming incident light shows two lobes, indicating that excitation is predominantly dipolar in nature although the size of some GNPs are big enough to show a quadrupolar response. It is believed that the presence of sharp tips at the surface of these large sized GNPs is responsible for the observed dipolar response. This study shows that GNPs having sharp tips might be a better candidate when their nonlinear properties are used for sensing applications.

Arsenic mobilization in the aquifers of three physiographic settings of West Bengal, India: understanding geogenic and anthropogenic influences

A comparative hydrogeochemical study was carried out in West Bengal, India covering three physiographic regions, Debagram and Chakdaha located in the Bhagirathi-Hooghly alluvial plain and Baruipur in the delta front, to demonstrate the control of geogenic and anthropogenic influences on groundwater arsenic (As) mobilization. Groundwater samples (n = 90) from tube wells were analyzed for different physico-chemical parameters. The low redox potential (Eh = -185 to -86 mV) and dominant As(III) and Fe(II) concentrations are indicative of anoxic nature of the aquifer. The shallow (<100 m) and deeper (>100 m) aquifers of Bhagirathi-Hooghly alluvial plains as well as shallow aquifers of delta front are characterized by Ca(2+)HCO3(-) type water, whereas Na(+) and Cl(-) enrichment is found in the deeper aquifer of delta front. The equilibrium of groundwater with respect to carbonate minerals and their precipitation/dissolution seems to be controlling the overall groundwater chemistry. The low SO4(2-) and high DOC, PO4(3-) and HCO3(-) concentrations in groundwater signify ongoing microbial mediated redox processes favoring As mobilization in the aquifer. The As release is influenced by both geogenic (i.e. geomorphology) and anthropogenic (i.e. unsewered sanitation) processes. Multiple geochemical processes, e.g., Fe-oxyhydroxides reduction and carbonate dissolution, are responsible for high As occurrence in groundwaters.

Remediation of inorganic arsenic in groundwater for safe water supply: a critical assessment of technological solutions

Arsenic contaminations of groundwater in several parts of the world are the results of natural and/or anthropogenic sources, and have a large impact on human health. Millions of people from different countries rely on groundwater containing As for drinking purposes. This paper reviews removal technologies (oxidation, coagulation flocculation, adsorption, ion exchange and membrane processes) with attention for the drawbacks and limitations of these applied technologies. The technologies suggested and applied for treatment of As rich water have various problems, including the need for further treatment of As containing secondary waste generated from these water treatment processes. More efficient technologies, with a lower tendency to generate waste include the removal of As by membrane distillation or forward osmosis, instead of using pressure driven membrane processes and subsequently reducing soluble As to commercially valuable metallic As are surveyed. An integrated approach of two or more techniques is suggested to be more beneficial than a single process. Advanced technologies such as membrane distillation, forward osmosis as well as some hybrid integrated techniques and their potentials are also discussed in this review. Membrane processes combined with other process (especially iron based technologies) are thought to be most sustainable for the removal of arsenic and further research allowing scale up of these technologies is suggested.

Synthesis of Some New Isoxazoline Derivatives of Chalconised Indoline 2-one as a Potential Analgesic, Antibacterial and Anthelmimtic Agents

A series of novel 1[5”-(2”’-substituted phenyl)-4”,5”’-dihydro isoxazole-3”-yl]-3-[(4 substituted phenyl)imino]1-3-dihydro-2H-indole-2-one were synthesized from different substituted chalconised indole-2,3-dione was prepared from the different chalconised Isatin. The structures of the compounds were elucidated by elemental and spectral (IR, ¹H NMR, and MS) analysis. The synthesized compounds were screened for their analgesic activity by the acetic acid induced Writhing method and in vitro antimicrobial activity against the Gram-positive bacteria—Staphylococcus aureus and the Gram-negative bacteria—Pseudomonas auroginosa, Pseudomonas mirabilis, and E. coli by the cup plate agar diffusion method. Compounds 6a₁, 6a₃, 6b₃, and 6b₂ were found to be active against bacteria. The compounds 6a₁, 6b₃, and 6a₃ show a significant analgesic activity. Synthesized compounds also screened for anthelmintic activity against Pheretima posthuma. Compounds 6a₁, 6b₁, and 6b₃ show significant anthelmintic activity.

Hooch blindness: a community study report on a few indoor patients of toxic optic neuropathy following consumption of adulterated alcohol in West Bengal

INTRODUCTION

Hooch blindness following consumption of adulterated alcohol has been known for centuries.

OBJECTIVE

To study cases of mass alcohol intoxication followed by Hooch blindness in eastern India.

MATERIALS AND METHODS

Ten patients of toxic amblyopia collected from a community mass intoxication following consumption of adulterated alcohol were studied. The parameters studied were the findings of ocular examination, applanation tonometry, automated perimetry and visual-evoked potential (VEP). As a part of the special investigations fundus photography and OCT were done. Routine blood examination, fasting lipid profile, postprandial blood sugar estimation were done . All patients were treated with injections of methyl prednisolone and Hydroxy cobalamine, antioxidants and local neuro-protective agents.

RESULTS

Along with diminished vision (from NPL to 3/60), marked pallor of the disc without any other retinal change were noted. The amplitude on VEP was significantly reduced. However, visual improvement (up to 6/18) in 7 patients was observed within 6 weeks of treatment.

CONCLUSION

Hooch blindness in India can be prevented by creating awareness among the target population and reducing the cost of country liquor.

Synthesis and evaluation of 1,3 di-substituted schiff, mannich bases and spiro isatin derivatives

Schiff bases of isatin with aminothiazole, its N-mannich bases and Spiro isatin derivatives were synthesized. Their chemical structures were confirmed by Infrared, 1H-Nuclear Magnetic Resonance data and elemental analysis. Antimicrobial evaluation was performed by the agar diffusion method against four pathogenic bacteria and two pathogenic fungi. Anti-inflammatory activity was tested by carragenin-induced rat paw edema and compounds were evaluated for analgesic action by the acetic acid-induced writhing method; Compounds Aa, Ab and A5, A6 were found to be active against bacteria and fungi. The compounds A3, A6, Aa and Ab showed anti-inflammatory activity, having a percentage protection value of 34.69, 32.65, 38.77 and 36.73 as compared with that of indomethacin, with % protection of 46.93. Similarly, the compounds Aa, Ab and A6 showed analgesic activity, with % protection of 67.51, 64.78 and 49.81 as compared with the standard with % protection of 79.56.

A Recyclable Heterogeneous Copper(II) Schiff Base Catalyst for the O-Arylation Reaction of Phenols with Aryl Halides

Immobilisation of copper acetate onto a modified polystyrene provided a polymer-supported copper(II) Schiff base catalyst, which is effective in the O-arylation reaction of phenols with aryl halides to give diaryl ethers in high yields. This catalyst is air-stable and was recycled for five times with minimal loss of activity.

An efficient and reusable polymer-supported palladium catalyst for the Suzuki cross-coupling reactions of aryl halides

A reusable, air-stable polymer-anchored palladium (II) Schiff base complex catalyst, P-[{(NCH)C6H4}Pd(OAc)]2 was prepared and was found to be highly active in Suzuki cross-coupling reactions of aryl halides with phenyl boronic acid in an aqueous medium to give biaryl products in high yields.