Soft Computing Based Prediction of Unconfined Compressive Strength of Fly Ash Stabilised Organic Clay

The current study uses machine learning techniques such as Random Forest Regression (RFR), Artificial Neural Networks (ANN), Support Vector Machines Ploy kernel (SVMP), Support Vector Machines Radial Basis Function Kernel (SVMRBK), and M5P model tree (M5P) to estimate unconfined compressive strength of organic clay stabilized with fly ash. The unconfined compressive strength of stabilized clay was computed by considering the different input variables namely i) the ratio of Cao to Sio2, ii) organic content (OC), iii) fly ash (FAper) content, iv) the unconfined compressive strength of organic clay without fly ash (UCS0) and v) the pH of soil-fly ash (pHmix). By comparing the performance measure parameters, each model performance is evaluated. The result of present study can conclude the random forest regression (RFR) model predicts the unconfined compressive strength of the organic clay stabilized with fly ash with least error followed by Support Vector Machines Radial Basis Function Kernel (SVMRBK), Support Vector Machines Ploy kernel (SVMP), Artificial Neural Networks (ANN) and M5P model tree (M5P). When compared to the semi-empirical model available in the literature, all of the model predictions given in this study perform well. Finally, the RFR and SVMRBK sensitivity analyses revealed that the CaO/SiO2 ratio was the most relevant parameter in the prediction of unconfined compressive strength

Interaction of a dinuclear fluorescent Cd(II) complex of calix[4]arene conjugate with phosphates and its applicability in cell imaging

A triazole-linked hydroxyethylimino conjugate of calix[4]arene (L) and its cadmium complex have been synthesized and characterized, and their structures have been established. In the complex, both the Cd2+ centers are bound by an N2O4 core, and one of it is a distorted octahedral, whereas the other is a trigonal anti-prism. The fluorescence intensity of the di-nuclear Cd(II) complex is quenched only in the presence of phosphates and not with other anions studied owing to their binding affinities and the nature of the interaction of the phosphates with Cd2+. These are evident even from their absorption spectra. Different phosphates exhibit changes in both their fluorescence as well as absorption spectra to varying extents, suggesting their differential interactions. Among the six phosphates, H2PO4- has higher fluorescence quenching even at low equivalents of this ion, whereas P2O74- shows only 50% quenching even at 10 equivalents. The fluorescence quenching is considerable even at 20 ppb (0.2 mu M) of H2PO4-, whereas all other phosphates require a concentration of 50-580 ppb to exhibit the same effect on fluorescence spectra. Thus, the interaction of H2PO4- is more effective by similar to 30 fold as compared to that of P2O74-. Fluorescence quenching by phosphate is due to the release of L from its original cadmium complex via the formation of a ternary species followed by the capture of Cd2+ by the phosphate, as delineated based on the combination of spectral techniques, such as absorption, emission, H-1 NMR and ESI MS. The relative interactive abilities of the six phosphates differ from each other. The removal of Cd2+ is demonstrated to be reversible by the repeated addition of the phosphate followed by Cd2+. The characteristics of the ternary species formed in each of these six phosphates have been computationally modeled using molecular mechanics. The computational study revealed that the coordination between cadmium and -CH2-CH2-OH breaks and new coordination is established through the phosphate oxygens, and as a result the Cd2+ center acquires a distorted octahedral geometry. The utility of the complex was demonstrated in HeLa cells

1,3-Di-amidoquinoline conjugate of calix[4]arene (L) as a ratiometric and colorimetric sensor for Zn2+: Spectroscopy, microscopy and computational studies

Carboxamidoquinoline appended calix[4]arene-1,3-di-conjugate (L) has been synthesized and characterized and its single crystal XRD structure has been established. L has been shown to act as selective ratiometric turn-on fluorescence sensor for Zn2+ up to a lowest concentration of 183 +/- 18 ppb (2.82 mu M) with a nine-fold enhancement by exhibiting blue-green emission. The coordination features of the species of recognition have been computationally evaluated by DFT methods and found to have distorted tetrahedral Zn2+ center in an N-4 core. The spherical nano-structural features observed for L in TEM are being transformed into the Koosh nano-flower like structure when complexed with Zn2+ and hence these two can be easily differentiated. Even the features observed in AFM can distinctly differentiate L from its Zn2+ complex

Triazole Linked Picolylimine Conjugate of Calix[6]arene as a Sequential Sensor for La3+ Followed by F-

A new 1,3,5-tris-triazole linked picolylimine conjugate of calix[6]arene (L) has been shown to be selective toward La3+ by turn on fluorescence with similar to 70-fold enhancement and emits blue, with a minimal detection limit of 65 +/- 5 ppb (490 nM). The species of recognition has been modeled computationally to have a monocapped twisted square antiprism with a N6O3 binding core about La3+. The in situ complex of L with La3+ recognizes F- via fluorescence quenching. The reversible response of sensing La3+ and F- sequentially by L has been demonstrated

Time- and Concentration-Dependent Reactivity of Cys, Hcy, and GSH on the Diels-Alder-Grafted 1,3,5-Tris Conjugate of Calix[6]arene To Bring Selectivity for Cys: Spectroscopy, Microscopy, and Its Reactivity in Cells

Herein we report the synthesis and characterization of 7-oxanorbornadiene (OND)-appended 1,3,5-tris conjugate of calix[6]arene (L-2). L2 has been shown to exhibit selective reactivity toward cysteine (Cys) over homocysteine (Hcy) and glutathione (GSH) under stoichiometric conditions. The selectivity of L-2 is attributed to the steric crowding of three Diels-Alder centers possessing OND units present on the calix[6]arene platform, while a control molecular system possessing only one such unit without the calix[6]arene platform (L1) does not show any selectivity toward Cys. While L2 exhibited spherical particles, its reactivity with Cys resulted in flowerlike morphological features, as revealed by scanning electron microscopy. However, the reaction with GSH did not result in any such morphological features, a result that is in agreement with that observed from fluorescence studies in solution. L-2 has been shown to react with Cys present in HeLa and Jurkat E6 cells by fluorescence microscopy

A fluorescent di-zinc(II) complex of bis-calix[4]arene conjugate as chemosensing-ensemble for the selective recognition of ATP

A triethylene glycol di-imine locked triazole linked bis-calix[4]arene conjugate L has been synthesised and characterised. Conjugate L exhibits high fluorescence enhancement towards Zn2+ among the 13 metal ions studied down to a lower detection limit of similar to 12 ppb. The absorption and visual colour change experiments differentiated the Zn2+ from the other metal ions studied. The isolated zinc complex, [Zn2L] has been used as a chemo-sensing ensemble for the recognition of anions based on their binding affinities towards Zn2+. [Zn2L] was found to be sensitive and selective towards phosphate-bearing species and in particular to adenosine triphosphate (ATP(2-)) among the other 20 anions studied as observed based on the changes occurred in the fluorescence intensity. The selectivity of the ATP(2-) has been shown on the basis of the changes observed in the emission and absorption spectral studies. The lowest detectable concentration for ATP(2-) with the chemosensing ensemble [Zn2L] is 348 ppb in methanol. The fluorescence quenching by the phosphate-based anions has been modelled by molecular mechanics studies and found that the anions possessing two or more phosphate moieties can only bridge between the two zinc centres, and hence those possessing only one phosphate moiety (H2PO4- and AMP(2-)) are ineffective

Refractive Errors Among School Going Children in Srikakulam District, North Coastal Andhrapradesh

Purpose : Avoidable blindness mainly due to uncorrected refractive errors is a major challenge to health care policy makers. School screening for refractive errors has been an useful programme to overcome this problem. The aim of the present study was to report the prevalence of refractive error among school children in srikakulam distict. Methods: A cross sectional study was carried out among 1682 school children between age group of 10-15 years under school screening programme. Results: the prevalence of refractive errors was found out to be 3.62%. the prevalence of refractive errors was more in female children (57.3%)when compared to male children(42.6%). The most common refractive error was found to be myopia(60.65%) followed by astigmatism(36%) followed by hypermetropia(3.27%). There is increased incidence of refractive errors in older age group 39.34% were present in 14-15 years of age. Conclusions: this study imparts screening of not only school going children but also all school aged children to treat refractive errors and prevent further complications by uncorrected refractive errors

Supramolecular Complexation of Biological Phosphates with an Acyclic Triazolium-Linked Anthracenyl-1,3-Diconjugate of Calix[4]Arene: Synthesis, Characterization, Spectroscopy, Microscopy, and Computational Studies

A triazolium-anthracenyl calix[4]arene conjugate (L) was synthesized by methylating the precursor triazole derivative and then characterized. The potential of the cationic L to differentiate nucleoside triphosphates (NTPs) from their mono- and diphosphates was demonstrated. Due to its unique combination of arms with the calix-platform, a fluorescence enhancement was observed for L with all the NTPs, whereas there is no report with such enhancement being exhibited in case of all the NTPs. This has been supported by the aggregation of L observed from microscopy. Selectivity of L towards NTPs over other phosphates was a result of specific weak interactions, namely, ion-ion, hydrogen bonding and , present in the 1:2 complex of L and NTPs (based on ESI MS), which were absent in their congener-phosphates as delineated by NMR and computational studies. Thus, L stands as a unique receptor for NTPs

Interaction of a dinuclear fluorescent Cd(II) complex of calix[4]arene conjugate with phosphates and its applicability in cell imaging

A triazole-linked hydroxyethylimino conjugate of calix[4]arene (L) and its cadmium complex have been synthesized and characterized, and their structures have been established. In the complex, both the Cd²⁺ centers are bound by an N₂O₄ core, and one of it is a distorted octahedral, whereas the other is a trigonal anti-prism. The fluorescence intensity of the di-nuclear Cd(II) complex is quenched only in the presence of phosphates and not with other anions studied owing to their binding affinities and the nature of the interaction of the phosphates with Cd²⁺. These are evident even from their absorption spectra. Different phosphates exhibit changes in both their fluorescence as well as absorption spectra to varying extents, suggesting their differential interactions. Among the six phosphates, H₂PO₄⁴⁻ has higher fluorescence quenching even at low equivalents of this ion, whereas P₂O₇⁴⁻ shows only 50% quenching even at 10 equivalents. The fluorescence quenching is considerable even at 20 ppb (0.2 μM) of H₂PO₄⁻, whereas all other phosphates require a concentration of 50–580 ppb to exhibit the same effect on fluorescence spectra. Thus, the interaction of H₂PO₄⁻ is more effective by ∼30 fold as compared to that of P₂O₇⁴⁻. Fluorescence quenching by phosphate is due to the release of L from its original cadmium complex via the formation of a ternary species followed by the capture of Cd²⁺ by the phosphate, as delineated based on the combination of spectral techniques, such as absorption, emission, ¹H NMR and ESI MS. The relative interactive abilities of the six phosphates differ from each other. The removal of Cd²⁺ is demonstrated to be reversible by the repeated addition of the phosphate followed by Cd²⁺. The characteristics of the ternary species formed in each of these six phosphates have been computationally modeled using molecular mechanics. The computational study revealed that the coordination between cadmium and –CH₂–CH₂–OH breaks and new coordination is established through the phosphate oxygens, and as a result the Cd²⁺ center acquires a distorted octahedral geometry. The utility of the complex was demonstrated in HeLa cells