Transport behavior of selected nanoparticles with different surface coatings in granular porous media coated with Pseudomonas aeruginosa biofilm

Well-controlled laboratory column experiments were conducted to understand the influence of Pseudomonas aeruginosa (P. aeruginosa) biofilms on the transport of selected engineered nanoparticles (ENPs) in granular porous media representative of groundwater aquifers or riverbank filtration settings. To understand the importance of particle size on retention in the biofilm-coated granular (quartz sand) matrix, column experiments were carried out using nanosized (20 nm) and micrometer-sized (1 μm) sulfate-functionalized polystyrene latex particles (designated as 20 nSL and 1 mSL, respectively). Additional experiments conducted with nanosized (20 nm) carboxyl-modified latex particles (20nCL) and carboxyl-modified CdSe/ZnS quantum dots (QDs) provide information on the influence of particle surface chemistry on retention. Biofilm grown on the surface of the sand was characterized by total biomass quantification, confocal laser scanning microscopy (CLSM), and electrokinetic analysis. All four particles exhibit increased retention in the biofilm-coated packed bed: e.g., the attachment efficiency (α) of the 1 mSL particle increases from 0.40 to 1.7, whereas α for the 20 nSL particle increases from 0.04 to 0.10 in the biofilm-coated system. Particle surface chemistry can also influence the affinity of the ENPs for the biofilm coating as revealed by the greater attachment of the 20 nSL particle onto the biofilm-coated sand (α = 0.10) than its carboxylated counterpart (α = 0.04). Column experiments conducted using sand coated with growth medium (LB) or extracellular polymeric substances (EPS) extracted from P. aeruginosa biofilms further reveal that particle surface chemistry influences the interaction between the different ENPs and these coated sand surfaces. Namely, coating of sand surfaces with LB medium or bacterial EPS does not affect the transport of the sulfonated nanoparticle, but the LB coating leads to decreased retention of the carboxylated latex nanoparticle. Furthermore, our results show that EPS coatings are not necessarily good surrogates for biofilm-coated sand. Electrokinetic characterization of the clean and coated sand surfaces also reveals that the extent of particle retention is not controlled by electrical double layer interactions. Future studies should thus be aimed at improving our understanding of the fundamental mechanisms (both colloidal and noncolloidal) governing nanoparticle transport and fate in biofilm-laden granular aquatic environments.     

Arsenate exposure affects amino acids, mineral nutrient status and antioxidants in rice (Oryza sativa L.) genotypes

Simulated pot experiments were conducted on four rice (Oryza sativa L.) genotypes (Triguna, IR-36, PNR-519, and IET-4786) to examine the effects of As(V) on amino acids and mineral nutrient status in grain along with antioxidant response to arsenic exposure. Rice genotypes responded differentially to As(V) exposure in terms of amino acids and antioxidant profiles. Total amino acid content in grains of all rice genotypes was positively correlated with arsenic accumulation. While, most of the essential amino acids increased in all cultivars except IR-36, glutamic acid and glycine increased in IET-4786 and PNR-519. The level of nonprotein thiols (NPTs) and the activities of superoxide dismutase (SOD; EC 1.15.1.1), glutathione reductase (GR; EC 1.6.4.2) and ascorbate peroxidase (APX; EC 1.11.1.11) increased in all rice cultivars except IET-4786. A significant genotypic variation was also observed in specific arsenic uptake (SAU; mg kg(-1)dw), which was in the order of Triguna (134) > IR-36 (71) > PNR-519 (53) > IET-4786 (29). Further, application of As(V) at lower doses (4 and 8 mg L(-1) As) enhanced the accumulation of selenium (Se) and other nutrients (Fe, P, Zn, and S), however, higher dose (12 mg L(-1) As) limits the nutrient uptake in rice. In conclusion, low As accumulating genotype, IET-4786, which also had significantly induced level of essential amino acids, seems suitable for cultivation in moderately As contaminated soil and would be safe for human consumption.     

Efficacy of application of vegetable seed oils as grain protectant against infestation by Callosobruchus chinensis and its effect on milling fractions and apparent degree of dehusking of legume-pulses

The solvent extracted vegetable seed oils of Cucurbitaceae family viz. Bitter gourd (Momordica charentia), Small bitter gourd (Momordica dioica), Bottle gourd (Lagenaria siscraria) and Ridge gourd (Luffa acutangula) were evaluated as grain protectant against callosobruchus chinensis on the stored legume-pulse grains. All the vegetable seed oils were found effective as legume-pulse grain protectant, which provided, negligible weight loss at the oil-application rate of 6-8 mL/kg in legume-pulse grain after 60 days storage at laboratory conditions. The milling yield and degree of dehusking gets improved after the oil application. The use of solvent extracted Small bitter gourd seed oil at the level of 6-8 mL/kg of legume-pulse grain sample resulted in the improved apparent degree of dehusking from 40.0 to 72.59, 59.88 to 92.44, 63.39 to 87.50 and 57.0 to 79.43 for Pigeonpea (Canjanus cajan), Chickpea (Cicer arietinum), Urdbean (Phaseolus mungo) and Mungbean (Phaseolus radiatus), respectively.     

Thermal modeling of passive and active solar stills for different depths of water by using the concept of solar fraction

This communication presents the thermal analysis of passive and active solar distillation system by using the concept of solar fraction inside the solar still with the help of AUTOCAD 2000 for given solar azimuth and altitude angle and latitude, longitude of the place. Experiments have been conducted for 24 h (9 am to 8 am) for New Delhi climatic conditions (latitude 28°35′N, longitude 77°12′E) during the months of November and December for different water depths in the basin (0.05, 0.1 and 0.15 m) for passive as well as active solar distillation system. Analytical expressions for water and glass cover temperatures and yield have been derived in terms of design and climatic parameters. It is observed that

(i) the solar fraction plays a very important role at lower values of solar altitude angle;

(ii) the internal convective heat transfer coefficient decreases with the increase of water depth in the basin due to decrease in water temperature;

(iii) there is a fair agreement between the experimental observation and theoretical prediction during daytime as compared to that during the night.

Modeling and Optimization of Enzymatic Degradation of Aflatoxin B1 (AFB1) in Red Chili Powder Using Response Surface Methodology

Response surface methodology was used to optimize the peroxidase-catalyzed enzymatic degradation of aflatoxin B₁ (AFB₁) from red chili powder. Twenty experiments were carried out using central composite rotatable design with three independent variables (enzyme concentration, substrate or AFB₁ concentration, and incubation time) and single response (% aflatoxin B₁ degradation). The optimum conditions achieved after numerical and graphical optimizations for maximum percent degradation were: AFB₁ (31.5 nM), enzyme (13.5 U/nM AFB₁), and time (26 h). The actual percent degradation achieved at these optimum conditions was 70.0% and predicted 74.5%. The reduced quadratic model developed for the experimental data was found adequate to describe the relationships between the operating variables (Model F = 21.61, p < 0.001; F _lof = 3.63, p > 0.05). The robustness of the model was tested by confirmation experiments, and difference was found insignificant between the actual and predicted values as confirmed by two-tailed t test (α = 0.05). The hepatotoxic effect of the AFB₁ pre- and post-detoxification was tested on Wistar rats. The detoxified powder was also tested for changes in ascorbic acid, β-carotene, ASTA color value, and capsaicin content. Capsaicin was resistant to enzymatic degradation under specified conditions, but loss of around 15% was reported in color and β-carotene content; the loss in ascorbic acid was 10%.     

Interaction between MoO3 and metals Te, Cd, Sb

Eighteen compositions of MoO₃-Te at 800 °C and seven of each of MoO₃-Cd (at 500 °C) and MoO₃-Sb (at 600 °C) were heat treated in vacuum-sealed quartz ampules. The phases of the heat-treated compositions were analyzed using x-ray diffraction (XRD) patterns. The interactions in the three systems are summarized. Three phases in equilibrium are (1) in the MnO₃-Te system at 800 °C, Te, Mo₄O₁₁, TeMo₄O₁₃—(0<x_{MoO 3}<0 889) and MoO₃, Mo₄O₁₁, TeMo₄O₁₃—(0.889<x_{MoO 3}<1); (2) in the MoO₃_Cd system at 500 °C, Cd, MoO₂, CdMoO₄—(0<x_{MoO 3}<0.6667) and MoO₃, MoO₂, CdMoO₄—(0.6667<x_{MoO 3}<1); and (3) in the MoO₃-Sb system at 600 °C, Sb, MoO₂, Sb₄Mo₁₀O₃₁—(0<x_{MoO 3}<0.734) and MoO₃+MoO₂+Sb₄Mo₁₀O₃₁ (0.734<x_{MoO 3}<1). The results lead to construction of ternary phase diagrams: Te-MoO₃-TeMo₄O₁₃, Cd-MoO₃-CdMoO₄, and Sb-MoO₃-Sb₄Mo₁₀O₃₁.     

Data mining algorithms for land cover change detection: a review

Land cover change detection has been a topic of active research in the remote sensing community. Due to enormous amount of data available from satellites, it has attracted the attention of data mining researchers to search a new direction for solution. The Terra Moderate Resolution Imaging Spectrometer (MODIS) vegetation index (EVI/NDVI) data products are used for land cover change detection. These data products are associated with various challenges such as seasonality of data, spatio-temporal correlation, missing values, poor quality measurement, high resolution and high dimensional data. The land cover change detection has often been performed by comparing two or more satellite snapshot images acquired on different dates. The image comparison techniques have a number of limitations. The data mining technique addresses many challenges such as missing value and poor quality measurements present in the data set, by performing the pre-processing of data. Furthermore, the data mining approaches are capable of handling large data sets and also use some of the inherent characteristics of spatio-temporal data; hence, they can be applied to increasingly immense data set. This paper stretches in detail various data mining algorithms for land cover change detection and each algorithm’s advantages and limitations. Also, an empirical study of some existing land cover change detection algorithms and results have been presented in this paper.     

Investigations of Al:CdS/PVA nanocomposites: A joint theoretical and experimental approach

In the present work we investigate the aluminium doped cadmium sulphide (Al:CdS) nanoparticles embedded in polyvinyl alcohol (PVA) matrix by chemical route and density functional theory (DFT) based simulations. Supertetrahedron (T_n) cluster models are considered for the simulation of CdS nanoparticles. Using DFT simulations on T_n clusters, we observe that band gap of ligated clusters is slightly more as compare to bare clusters. This indicates the ability of organic ligands (PVA) to open the band gap of inorganic CdS nanoclusters. Negative value of binding energy indicates the stability of the inorganic–organic hybrid system. Frontier molecular orbitals (FMOs) indicate the charge transfer between organic and inorganic moieties which provides stability and longevity to nanoparticles, a prime function of ligands in nanocomposites. Absorption spectra of pure and doped clusters are calculated using time dependent density functional theory (TDDFT). CdS/PVA and Al:CdS/PVA samples are synthesized at room temperature by chemical method. Their structure, size and band gap is characterized by XRD, TEM, FTIR and UV spectroscopy. Optical band gap values as observed experimentally are in agreement with simulated TDDFT results.     

Donor Genetic Predisposition to High Interleukin-10 Production Appears Protective against Acute Graft-Versus-Host Disease

The persistence of graft-versus-host disease (GVHD) as the principal complication of allogeneic hematopoietic cell transplantation (HCT) demonstrates that HLA matching alone is insufficient to prevent alloreactivity. We performed molecular and functional characterization of 22 candidate cytokine genes for their potential to improve matching in 315 myeloablative, 10/10 HLA-matched donor–recipient pairs. Recipients of a graft carrying the -1082GG IL10 gene promoter region variant had a three-fold lower incidence of grade II–IV acute GVHD compared to IL10-1082AA graft recipients (SHR = 0.25, p = 0.005). This was most evident in matched unrelated donor (MUD) transplants, where the greatest alloreactivity is expected. IL10-1082GG transplants did not experience an increased incidence of relapse, and, consequently, overall survival was two-fold higher in IL10-1082GG MUD transplants (HR = 0.17, p = 0.023). Longitudinal post-transplant measurements demonstrated that -1082GG is a high-IL10-producing and -expressing genotype with attenuated CD8⁺ T-cell reconstitution. High post-transplant donor chimerism in T- and myeloid-cells (>95%) confirmed a predominant donor, rather than recipient, genotype effect on immune function and aGVHD. To date, this is the first study to report corroborating genome-to-cellular evidence for a non-HLA donor immunogenetic variant that appears to be protective against GVHD. The incorporation of IL10 variants in donor selection criteria and clinical-management decisions has the potential to improve patient outcomes.