Silver induced chirality controlled spin filtration observed in ss-DNA functionalized with MoS2.

Chiral molecules can exhibit strong spin-orbit coupling, which can result in a large spin polarization. This is due to the fact that the energy levels of the electrons in a chiral molecule are strongly influenced by the chiral structure of the molecule, which can result in the separation of the energy levels for electrons with different spin orientations. We report a controlled spin-selective transmission of electrons through 20 base-paired poly-cytosine molecules functionalized with MoS2 flakes on ITO glass via the quantum mechanical tunneling effect. A reversion in spin polarization was observed after the silver ions interact with poly-cytosine due to the strong coordination of Ag(I) with cytosine-cytosine (C-C) mismatches, indicating the formation of duplex structural motifs, as confirmed by the circular dichroism spectroscopy at room temperature. Manipulating the spin of an electron through such a small molecule merely controlled by special cations could pave the way for major advances in spin-independent charge transport, advanced bioanalytical system design, and related applications.

Electron spin polarization in supramolecular polymers with complex pathways.

Mastering the manipulation of the electron spin plays a crucial role in comprehending the behavior of organic materials in several applications, such as asymmetric catalysis, chiroptical switches, and electronic devices. A promising avenue for achieving such precise control lies in the Chiral Induced Spin Selectivity (CISS) effect, where electrons with a favored spin exhibit preferential transport through chiral assemblies of specific handedness. Chiral supramolecular polymers emerge as excellent candidates for exploring the CISS effect due to their ability to modulate their helical structure through noncovalent interactions. In this context, systems capable of responding to external stimuli are particularly intriguing, sometimes even displaying chirality inversion. This study unveils spin selectivity in chiral supramolecular polymers, derived from single enantiomers, through scanning tunneling microscopy conducted in scanning tunneling spectroscopy mode. Following two distinct sample preparation protocols for each enantiomer, we generate supramolecular polymers with opposite handedness and specific spin transport characteristics. Our primary focus centers on chiral π-conjugated building blocks, with the aim of advancing novel systems that can inspire the organic spintronics community from a supramolecular chemistry level.

Manipulating electron-spin polarization using cysteine-DNA chiral conjugates.

The chiral molecules are potential generators of high spin-filters due to their inherent inversion asymmetric helical electric field. We report a controlled spin-selective transmission of electrons through self-assembled monolayers of 15 base-paired double-stranded deoxyribonucleic acid functionalized with two enantiomeric cysteine molecules on gold explored through the quantum mechanical tunneling effect. We observed a controlled spin polarization of 33% with dextro-cysteine, whereas a mere 8% was observed with levo-cysteine molecules using these functionalizations at room temperature. The manipulation of electron's spin merely through such a small molecule could lead to significant advancement in the spin-dependent charge transport phenomena and related applications.

A pilot plant study of the degradation of Brilliant Green dye using ozone microbubbles: mechanism and kinetics of reaction.

Oxidation of Brilliant Green dye was performed using ozone microbubbles in a pilot plant scale. Decolourisation was very effective at both acidic and alkaline pH. The colour of the aqueous solution was below detectable limit after 30 min at 1.7 mg/s ozone generation rate. The reaction between the dye and ozone was first-order in nature with respect to both ozone and the dye. The enhancement factor increased with increasing dye concentration. The samples were analysed by the ultra-violet-visible (UV-Vis) spectrophotometry, gas chromatography-mass spectrometry (GC-MS) and Fourier transform infra-red (FTIR) spectroscopy. From the GC-MS analysis, 13 intermediates were detected as oxidation products of this dye at various stages of oxidation. The changes in the FTIR spectra showed the destruction of the dye and the formation of new compounds. The oxidation mechanism was divided into two reaction pathways. The mineralisation of Brilliant Green was up to 80% in 60 min, as determined by total organic carbon analysis.

Light Microscopic and Scanning Electron Microscopic Techniques to Characterize Nutlets of Some Indian Cyperoideae (Cyperaceae) and Their Taxonomic Significance.

In the present investigation, nutlet morphological and micro-morphological characters were analyzed using Light Microscope (LM) and Scanning Electron Microscope (SEM) in 38 taxa under 13 genera from the sub-family Cyperoideae of Cyperaceae to find out whether these characters are taxonomically important or not. Nutlet morphology and surface characters of the representative taxa from all the possible tribes under the sub-family Cyperoideae namely, Fuireneae, Cypereae, Cariceae, Abildgaardieae, Eleocharideae, Pseudoschoeneae, Schoenoplecteae, and Sclerieae were evaluated for their taxonomic significance. Cluster analysis was employed considering nutlet morphological characters to determine the overall similarity among the taxa based on 153 character states. Except in few specified cases, grouping of the taxa in the clusters is in accordance to the taxonomic treatments made by recent Cyperologists. Nutlets in the tribe Abildgaardieae showed maximum level of variability in size, shape, and surface ornamentation at the level of higher taxon, but showed specificity at the species level. Tuberculate, striate-reticulate, and transversely wavy ridged surface ornamentations were found in different species of Fimbristylis. Previously described cryptic variation, and effect of different ploidy level were not reflected in nutlet surface morphology and micromorphology in Fimbristylis dichotoma and F. ovata complexes which was previously made the taxa taxonomically very difficult. Serrulate anticlinal wall in F. bisumbellata was the most unique in Fimbristylis. Species under the megadiverse genus Carex representing the tribe Cariceae showed very unique type of surface ornamentation. Surface walls of all the studied species of Carex were characterized by polygonal epidermal cells with single conical silica body (2-3 per cell in C. speciosa) of variable length and sizes. Most interestingly, in C. nubigena, presence of the central silica body and peripheral satellites was not consistent. Based on the presence and absence, two different variants under the species were identified. In C. nubigena, when silica body was present, epidermal cells were characterized by central conical silica body surrounded by variable number of satellites. The present investigation first time reports this novel nutlet surface character in C. nubigena. Among the studied characters, length and height of conical, height of apex, and width of apex are variable among Carex species. On the other hand, exclusion of the genera Schoenoplectiella and Schoenoplectus from tribe Scirpeae s.l. and placement under the tribes Pseudoschoeneae and Schoenoplecteae (respectively) was also supported by the present investigation. The present study also confirms that nutlet morphological and micro-morphological characters are useful in identification and arrangement of different taxa under the subfamily Cyperoideae of Cyperaceae. Result of the present investigation was correlated and discussed in comparative manner with the treatments of the recent past.

Metal-oxide coated Graphene oxide nano-composite for the treatment of pharmaceutical compound in photocatalytic reactor: Batch, Kinetics and Mathematical Modeling using Response Surface Methodology and Artificial Neural Network.

Titanium dioxide (TiO2) photocatalyst has gained constant interest in the treatment of wastewater because of its greater stability, lower cost, low-toxicity, high efficiency, and more reactivity under UV radiation. On the other hand, Graphene oxide (GO) possesses high electron mobility, and therefore when GO is combined with TiO2, the photocatalytic activity of TiO2 is increased. In this study, nano-composite was synthesized in a hydrothermal reactor using two types of TiO2 nanoparticles (TiO2 consisting of a mixture of rutile and anatase phase (Type 1) and bioreduced TiO2 (Type 2)) and the efficiency of both the TiO2-GO nanocomposite to remove the drug Carbamazepine (CBZ) was investigated. The TiO2-GO nanocomposite with the Type 1 TiO2 exhibited greater efficiency hence further studies were conducted with that composite. The efficiency of TiO2-GO nanocomposite for the purpose of removing CBZ were investigated in presence of different types of incident radiation like Solar radiation, white light and three type of Ultraviolet radiation (A, B, C). The removal of the drug by TiO2-GO composite has been optimized using response surface methodology and artificial neural network. From this study, the maximum reduction was observed was 91.2% and whereas in case of the RSM optimization study the maximum removal that was observed was 91.7%. The validation of the RSM model was done using the mathematical analysis of the model equation of RSM. Different kinetics models was also analyzed using the experimental data and it was observed that it followed pseudo-second-order kinetics. The optimization using ANN also showed a close interaction with the experimental results.

Oxygen vacancy assisted condensation of DNA molecule observed on ZnO thin film.

An exotic condensation of DNA molecules is observed on the nanostructured ZnO surface. The ZnO nanostructures (NS) fabricated by thermal vapor deposition technique were associated with a large number of oxygen vacancies on the surface. These oxygen vacancies induced changes in the DNA conformation which further reflected through changes in the persistence length of the DNA molecules. This indicates a reinforcement of the bonds and binding in both the phosphate and the base regions of the DNA molecules with the positively charged core vacancy sites on the ZnO nanostructured surface through strong interaction mediated via long-range electrostatic forces which effectively reduced the end-to-end distance of the λ-DNA molecule. This strongly suggests a transition of the λ-DNA molecule through structural modification into a more compact higher-order fractal dimension from its native state.

Treatment of a Pharmaceutical Industrial Effluent by a Hybrid Process of Advanced Oxidation and Adsorption.

In the present study, a combined approach of ozone-based advanced oxidation and adsorption by activated char was employed for the treatment of a pharmaceutical industrial effluent. Ozone is a selective oxidant, but the addition of H2O2 generated in situ hydroxyl radicals, which is a non-selective stronger oxidant than ozone. The effluent obtained from the pharmaceutical industry mainly contained anti-cancer drugs, anti-psychotic drugs, and some pain killers. The peroxone process had 75-88.5% chemical oxygen demand (COD) reduction efficiency at pH 5-11 in 3 h. Adsorption by activated char further reduced the COD to 85.4-92.7% for pH 5-11 in 2.5 h. All other water quality parameters were significantly decreased (>73% removal) during ozonation. The primary operational parameters (system pH and H2O2 concentration) were also varied, and their effects were analyzed. The pseudo-first-order rate constants for ozonation were calculated, and they were found to be in the range of 1.42 × 10-4 to 3.35 × 10-4 s-1 for pH 5-11. The kinetic parameters for adsorption were calculated for the pseudo-first-order, pseudo-second-order, and Elovich models. The fit of the pseudo-first-order kinetic model to the experimental data was the best.

Oxidation of As(III) to As(V) using ozone microbubbles.

The use of ozone in the treatment of water and wastewater is rapidly increasing due to its high oxidizing power. Arsenic is one the most toxic elements found in water. As(III) and As(V) are the major sources of arsenic poisoning. It is known that As(V) can be more easily removed from water by adsorptive methods than As(III). In this work, oxidation of more toxic As(III) to less toxic As(V) was studied in a pilot-plant by using ozone microbubbles. The microbubbles were effective in dissolving ozone in water. The oxidation was fast over a wide range of pH (e.g., 4-9). The role of hydroxyl radical in the oxidation of As(III) under acidic conditions was investigated by using 2-propanol as the hydroxyl radical scavenger. Under acidic conditions, the addition of 2-propanol slowed down the oxidation, which proves that hydroxyl radicals were involved in the oxidation process. The effect of carbonate ions on the rate of oxidation was investigated. It was found that the generation of carbonate ion radical from the carbonate ion accelerated the oxidation of As(III). The kinetics of oxidation of As(III) by ozone was studied.

A novel chitosan based antimalarial drug delivery against Plasmodium berghei infection.

Chitosan is a natural polysaccharide that has attracted significant scientific interest during the last two decades and chitosan based nanodrug delivery systems seem to be a hopeful and viable strategy for improving disease treatment. This study aims to evaluate the potency of the polymer based nanochloroquine in application for attenuation of Plasmodium berghei infection in Swiss mice and effectiveness against the parasite induced oxidative stress and deoxyribo nucleic acid (DNA) damage in lymphocytes. Nanoparticle was prepared by ionotropic gelation between chitosan and sodium tripolyphosphate. The chloroquine was treated by the actual drug content of effective nanochloroquine and the nanodrug was charged with its effective dose for fifteen days, after successive infection development in Swiss mice. Gimsa staining of thin smear and flow cytometry analysis was pursued to reveal the parasitemia. Different oxidative markers, inflammatory markers, antioxidant enzymes level and also lymphocytic deoxyribo nucleic acid damage study were performed. The present study reveals the potency of the nanodrug which has been found as more prospective than only chloroquine treatment to combat the parasite infection, oxidative stress as well as inflammation and DNA damage. From the study, we conclude this nanodrug may be applicable as potent therapeutic agent than only chloroquine.

Berberine chloride mediates its anti-leishmanial activity via differential regulation of the mitogen activated protein kinase pathway in macrophages.

BACKGROUND: A complex interplay between Leishmania and macrophages influences parasite survival and necessitates disruption of signaling molecules, eventually resulting in impairment of macrophage function. In this study, we demonstrate the immunomodulatory activity of Berberine chloride in Leishmania infected macrophages. PRINCIPAL FINDINGS: The IC(50) of Berberine chloride, a quaternary isoquinoline alkaloid was tested in an amastigote macrophage model and its safety index measured by a cell viability assay. It eliminated intracellular amastigotes, the IC(50) being 2.8 fold lower than its IC(50) in promastigotes (7.10 µM vs. 2.54 µM) and showed a safety index >16. Levels of intracellular and extracellular nitric oxide (NO) as measured by flow cytometry and Griess assay respectively showed that Berberine chloride in Leishmania infected macrophages increased production of NO. Measurement of the mRNA expression of iNOS, IL-12 and IL-10 by RT-PCR along with levels of IL-12p40 and IL-10 by ELISA showed that in infected macrophages, Berberine chloride enhanced expression of iNOS and IL-12p40, concomitant with a downregulation of IL-10. The phosphorylation status of extracellular signal related kinase (ERK1/2) and p38 mitogen activated protein kinase (p38 MAPK) was studied by western blotting. In infected macrophages, Berberine chloride caused a time dependent activation of p38 MAPK along with deactivation of ERK1/2; addition of a p38 MAPK inhibitor SB203580 inhibited the increased generation of NO and IL-12p40 by Berberine chloride as also prevented its decrease of IL-10. CONCLUSIONS: Berberine chloride modulated macrophage effector responses via the mitogen activated protein kinase (MAPK) pathway, highlighting the importance of MAPKs as an antiparasite target.