A data-driven approach for simplifying the estimation of time for contaminant plumes to reach their maximum extent.

Globally there exist a very large number of contaminated or possibly contaminated sites where a basic preliminary assessment has not been completed. This is largely, among others, due to limited simple methods/models available for estimating key site quantities such as the maximum plume length, further denoted as Lmax and the corresponding time T=TLmax, at which the plume reaches its maximum extent L=Lmax. An approach to easily obtain an estimate of TLmax in particular is presented in this work. Limited availability of high-quality field data, particularly of TLmax, necessitates the use of synthetic data, which constrains the overall model development works. Taking BIOSCREEN-AT (transient 3D model) as a base model, this work proposes second-order polynomial models, with only two parameters, for estimating Lmax and TLmax. This reformulation of the well established solution significantly reduces data requirement and workload for initial site assessment purposes. A global sensitivity analysis (Morris, 1991), using a large number of random synthetic data, identifies the first-order decay rate constants in the plume λEFF and at the source γ as dominantly most influential for TLmax. For Lmax, the first-order decay rate constant λEFF and groundwater velocity v are the two important parameters. The sensitivity analysis also identifies that these parameters non-linearly impact TLmax or Lmax. With this information, the proposed polynomial models (each for Lmax and TLmax) were trained to obtain model coefficients, using a large amount of synthetic data. For verification, the developed models were tested using four datasets comprising over 100 sample sets against the results obtained from BIOSCREEN-AT and the developed BIOSCREEN-AT-based steady-state model. Additionally, the developed models were evaluated against two well documented field sites. The proposed models largely simplify estimation, particularly, of TLmax, for which only very limited field or literature information is available.

Development and validation of simultaneous quantification method for gemcitabine and betulinic acid: augmenting industrial application.

Combinatorial treatment utilizing a nucleoside analogue gemcitabine (GEM), with a characteristic pentacyclic triterpenoid betulinic acid (BET), has exhibited empowering adequacy in the therapy of cancer. It lessens the advancement of collagen and upgrades the saturation of tumour medicines. With the advancement in nanotechnology, the co-loaded formulation urges for a validated method of estimation. The purposed work entails a robust, simple, and economical analytical method for the simultaneous estimation of GEM and BET through RP-HPLC. Orthophosphoric acid (0.1%)-acetonitrile was considered as the mobile phase for the detection of GEM and BET at 248 nm and 210 nm with retention times of 5 min and 13 min, respectively. The method was further validated as per the regulatory guidelines with all the parameters found within the limit. The developed method with adequate resolution and quantification was found to be linear, accurate, precise, robust, and stable with an intra- and inter-day variability of less than 2%. The method was found specific for GEM and BET with no matrix interference of drug-spiked FBS samples. To demonstrate the applicability of the developed method, a nano-formulation containing GEM and BET was prepared and assessed for various parameters including encapsulation efficiency, loading efficiency, drug release, and drug stability. The method developed can be a possible tool for the simultaneous quantification of GEM-BET in analytical and biological samples.

Amoxicillin impact on pathophysiology induced by short term high salt diet in mice.

Current evidence emerging from both human and animal models confirms that high-salt diet consumption over a period modulates the gut ecology and subsequently accelerates the development of the pathophysiology of many metabolic diseases. The knowledge of short-term intake of a high-salt diet (HSD) on gut microbiota and their role in the progression of metabolic pathogenesis and the consequence of a typical course of common antibiotics in this condition has yet not been investigated. The present study elicited this knowledge gap by studying how the gut microbiota profile changes in mice receiving HSD for a short period followed by Amoxicillin treatment on these mice in the last week to mimic a typical treatment course of antibiotics. In this study, we provided a standard chow diet (CD) and HSD for 3 weeks, and a subset of these mice on both diets received antibiotic therapy with Amoxicillin in the 3rd week. We measured the body weight of mice for 3 weeks. After 21 days, all animals were euthanised and subjected to a thorough examination for haemato-biochemical, histopathological, and 16S rRNA sequencing, followed by bioinformatics analysis to determine any changes in gut microbiota ecology. HSD exposure in mice for short duration even leads to a significant difference in the gut ecology with enrichment of specific gut microbiota crucially linked to developing the pathophysiological features of metabolic disease-related inflammation. In addition, HSD treatment showed a negative impact on haemato-biochemical parameters. However, Amoxicillin treatment in HSD-fed mice restored the blood-biochemical markers near to control values and reshaped gut microbiota known for improving the pathophysiological attributes of metabolic disease related inflammation. This study also observed minimal and insignificant pathological changes in the heart, liver, and kidney in HSD-fed mice.

Carbon removal from a mirror-like gold surface by UV light, RF plasma, and IR laser exposure: a comparative study.

A decrease in photon intensity due to carbon contamination on optical elements is a serious issue in synchrotron radiation (SR) beamlines. Photon intensity can be regained by refurbishment of optical elements using suitable techniques. In the literature, three suitable techniques [radio frequency (RF) plasma, ultraviolet (UV) radiation (λ=172nm), and infrared (IR) laser (λ=1064nm) exposure] are reported to remove carbon contaminations from optical elements. These techniques are used independently to remove carbon, and, to the best of our knowledge, no systematic study is available on their relative efficiencies and effects on a mirror surface. We have applied these techniques independently for removal of carbon contamination from a gold surface, and detailed surface characterizations are carried out using soft x-ray reflectivity, x-ray photoelectron spectroscopy, Raman spectroscopy, and atomic force microscopy techniques. Characterization results suggest that all three techniques are capable of removing carbon contamination with certain limitations. Here, detailed relative effects on a gold surface after cleaning experiments with three techniques are discussed.

Biocompatibility analysis of PLA based candidate materials for cardiovascular stents in a rat subcutaneous implant model.

Modification of Polylactic acid (PLA), a biopolymer, is a strategy still to be fully explored for the next generation of bioresorbable vascular stent (BVS) biomaterials. With this focus, inclusions upto 5% of Polycaprolactone (PCL) and Magnesium in PLA were tested in the rat subcutaneous model and their cellular and tissue interactions characterized, specifically with respect to inflammatory response, angiogenesis and capsularization. The cytokines IL6, TNF Alpha and IL-1Beta were estimated in the peri-implant tissue, all of which showed a non-significant difference between the non-implanted animals and those containing PLA by 8 weeks, speaking to the benign nature of PLA as an implant biomaterial. Both modified materials, had increased macrophage counts and cytokine levels, except IL6 at 8 weeks. Vascularization only at 8 weeks in PLA PCL containing tissue was significantly higher than pure PLA, which may be more carefully controlled along with the material hydrophobicity for possible efforts towards therapeutic angiogenesis. Capsule thickness, measured by staining with both Hematoxylin & Eosin and Masson's Trichome did not show any differences between materials, including PLA.

Influence of recharge rates on steady-state plume lengths.

A large number of potentially contaminated sites reported worldwide require cost- and time-effective assessment of the extent of contamination and the threats posed to the water resources. A significant risk assessment metric for these sites can be the determination of the maximum (i.e., steady-state) contaminant plume length (Lmax). Analytical approaches in the literature provide an option for such an assessment, but they include a certain degree of uncertainty. Often, the causes of such uncertainties are the simplifications in the analytical models, e.g., not considering the influence of hydrogeological stresses such as recharge, which impact the plume development significantly. This may lead to an over- or underestimation of Lmax. This work includes the influence of the recharge for the effective estimation of Lmax. For that, several two-dimensional (2D) numerical simulations have been performed by considering different aquifer thicknesses (1 m- 4 m) and recharge rates (ranging from 0 to 3.6 mm/day). From the numerical results of this work, it has been deduced that 1) the application of the recharge shortens Lmax, and the recharge entering the aquifer top causes the plume to tilt, 2) the reduction percentage in Lmax depends on the recharge rate applied and the aquifer thickness, and 3) the reduction percentage varies in a non-linear manner with respect to the recharge rate for a fixed aquifer thickness. Based on these results, a hybrid analytical-empirical solution has been developed for the estimation of Lmax with the inclusion of the recharge rate. The proposed hybrid analytical-empirical solution superimposes an empirically obtained correction factor onto an analytical solution. Although extensive confirmation steps of the developed model are required for including the effect of the recharge on aquifer hydraulics, the proposed expression improves the estimation of the Lmax significantly. The hybrid analytical-empirical solution has also been confirmed with a selection of limited field contamination sites data. The hybrid model result (Lhyb) provides a significant improvement in the estimation, i.e., an order of magnitude lower mean relative error compared to the analytical model.

Influence of the core-hole effect on optical properties of magnesium oxide (MgO) near the Mg L-edge region.

The influence of the core-hole effect on optical properties of magnesium oxide (MgO) is established through experimental determination of optical constants and first-principles density functional theory studies. Optical constants (δ and ß) of MgO thin film are measured in the spectral region 40-300 eV using reflectance spectroscopy techniques at the Indus-1 synchrotron radiation source. The obtained optical constants show strong core exciton features near the Mg L-edge region, causing significant mismatch with Henke's tabulated values. On comparing the experimentally obtained optical constants with Henke's tabulated values, an edge shift of ∼3.0 eV is also observed. Distinct evidence of effects of core exciton on optical constants (δ and ß) in the near Mg L-edge absorption spectra are confirmed through first-principles simulations.

Structural variation in a synchrotron-induced contamination layer (a-C:H) deposited on a toroidal Au mirror surface.

A carbon layer deposited on an optical component is the result of complex interactions between the optical surface, adsorbed hydrocarbons, photons and secondary electrons (photoelectrons generated on the surface of optical elements). In the present study a synchrotron-induced contamination layer on a 340 mm × 60 mm Au-coated toroidal mirror has been characterized. The contamination layer showed a strong variation in structural properties from the centre of the mirror to the edge region (along the long dimension of the mirror) due to the Gaussian distribution of the incident photon beam intensity/power on the mirror surface. Raman scattering measurements were carried out at 12 equidistant (25 mm) locations along the length of the mirror. The surface contamination layer that formed on the Au surface was observed to be hydrogenated amorphous carbon film in nature. The effects of the synchrotron beam intensity/power distribution on the structural properties of the contamination layer are discussed. The I(D)/I(G) ratio, cluster size and disordering were found to increase whereas the sp2:sp3 ratio, G peak position and H content decreased with photon dose. The structural parameters of the contamination layer in the central region were estimated (thickness ≃ 400 Å, roughness ≃ 60 Å, density ≃ 72% of bulk graphitic carbon density) by soft X-ray reflectivity measurements. The amorphous nature of the layer in the central region was observed by grazing-incidence X-ray diffraction.

In silico analysis of pectin lyase and pectinase sequences.

A total of 48 full-length protein sequences of pectin lyases from different source organisms available in NCBI were subjected to multiple sequence alignment, domain analysis, and phylogenetic tree construction. A phylogenetic tree constructed on the basis of the protein sequences revealed two distinct clusters representing pectin lyases from bacterial and fungal sources. Similarly, the multiple accessions of different source organisms representing bacterial and fungal pectin lyases also formed distinct clusters, showing sequence level homology. The sequence level similarities among different groups of pectinase enzymes, viz. pectin lyase, pectate lyase, polygalacturonase, and pectin esterase, were also analyzed by subjecting a single protein sequence from each group with common source organism to tree construction. Four distinct clusters representing different groups of pectinases with common source organisms were observed, indicating the existing sequence level similarity among them. Multiple sequence alignment of pectin lyase protein sequence of different source organisms along with pectinases with common source organisms revealed a conserved region, indicating homology at sequence level. A conserved domain Pec_Lyase_C was frequently observed in the protein sequences of pectin lyases and pectate lyases, while Glyco_hydro_28 domains and Pectate lyase-like beta-helix clan domain are frequently observed in polygalacturonases and pectin esterases, respectively. The signature amino acid sequence of 41 amino acids, i.e. TYDNAGVLPITVNSNKSLIGEGSKGVIKGKGLRIVSGAKNI, related with the Pec_Lyase_C is frequently observed in pectin lyase protein sequences and might be related with the structure and enzymatic function.

Purification and characterization of pectin lyase secreted by Penicillium citrinum.

The importance of various parameters such as sugarcane juice concentration, pH of the medium, and effects of different solid supports for maximum secretion of pectin lyase from Penicillium citrinum MTCC 8897 has been studied. The enzyme was purified to homogeneity by Sephadex G-100 and DEAE-cellulose chromatography. The molecular mass determined by SDS-PAGE was 31 kDa. The K(m) and k(cat) values were found to be 1 mg/ml and 76 sec(-1), respectively. The optimum pH of the purified pectin lyase was 9.0, though it retains activity in the pH 9.0-12.0 range when exposed for 24 h. The optimum temperature was 50 degrees C, and the pectin lyase was found to be completely stable up to 40 degrees C when exposed for 1 h. The purified pectin lyase was found efficient in retting of Linum usitatissimum, Cannabis sativa, and Crotalaria juncea.

Prognostic significance of DNA aneuploidy and p21 ras oncoprotein expression in colorectal cancer and their role in the determination of treatment modalities.

The purpose of the present study was to investigate the prognostic significance of DNA ploidy, S-phase fraction and p21 ras oncoprotein expression in patients with colorectal cancer and to correlate these factors with the clinical behavior of the tumors and their response to therapy. Of 79 patients with colorectal cancer 57% (45/79) had early stage disease. Forty-one percent (32/79) had aneuploid tumors while 30% (24/79) of the tumors had a high (>10%) S-phase fraction. p21ras oncoprotein expression was detected in 38% (30/79) of tumors. Patients with aneuploid tumors had a worse prognosis than patients with diploid tumors (p=0.0002). Similarly, patients with high S-phase fraction tumors had a shorter survival than those with low S-phase fraction tumors (p=0.005). No such difference was found between p21 raspositive and p21 ras-negative tumor subgroups. In early stage colorectal cancer, aneuploidy was closely correlated with disease outcome (p=0.029). Early stage patients with diploid tumors who received radiotherapy and chemotherapy had a better prognosis than patients with aneuploid tumors. In conclusion, DNA ploidy is a significant and independent prognostic factor in colorectal cancer. Aneuploidy and genetic alteration of the p21 ras oncoprotein are important in determining the biological aggressiveness of colorectal cancer. Furthermore, DNA ploidy may identify those subgroups of patients with early stage disease who may benefit from more aggressive treatment.

Chemomodulation of carcinogen metabolising enzymes, antioxidant profiles and skin and forestomach papillomagenesis by Spirulina platensis.

Numerous reports have revealed an inverse association between consumption of some selective natural products and risk of developing cancer. In the present study the effect of 250 and 500 mg/kg body wt. of Spirulina was examined on drug metabolising phase I and phase II enzymes, antioxidant enzymes, glutathione content, lactate dehydrogenase and lipid peroxidation in the liver of 7-week-old Swiss albino mice. The implications of these biochemical alterations have been further evaluated adopting the protocol of benzo(a)pyrene induced forestomach and 7,12 dimethylbenz(a)anthracene (DMBA) initiated and croton oil promoted skin papillomagenesis. Our primary findings reveal the 'Monofunctional' nature of Spirulina as deduced from its potential to induce only the phase II enzyme activities associated mainly with carcinogen detoxification. The glutathione S-transferase and DT-diaphorase specific activities were induced in hepatic and all the extrahepatic organs examined (lung, kidney and forestomach) by Spirulina pretreatment (significance level being from p < 0.05 to p < 0.005) except for the low dose treatment in forestomach. With reference to antioxidant enzymes viz., superoxide dismutase, catalase, glutathione reductase, glutathione peroxidase and reduced glutathione were increased significantly by both the chosen doses of Spirulina from p < 0.01 to p < 0.005. Chemopreventive response was quantitated by the average number of papillomas per effective mouse (tumor burden) as well as percentage of tumor bearing animals. There was a significant inhibition of tumor burden as well as tumor incidence in both the tumor model systems studied. In the skin tumor studies tumor burden was reduced from 4.86 to 1.20 and 1.15 by the low and high dose treatment respectively. In stomach tumor studies tumor burden was 2.05 and 1.73 by the low and high doses of Spirulina treatment against 3.73 that of control.