@proceedings { ISI:000291657600151, title = {Ce-Al-MCM-41: an efficient catalyst for Mukaiyama-Michael reaction}, volume = {170}, year = {2007}, note = {15th International Zeolite Conference, Beijing, PEOPLES R CHINA, AUG 12-17, 2007}, month = {AUG}, pages = {1161-1166}, publisher = {Elsevier Science BV}, address = {Sara Burgerhartstraat 25, Po Box 211, 1000 AE Amsterdam, Netherlands}, abstract = {

The activity of cerium containing Al-MCM-41 mesoporous materials has been studied for carbon-carbon bond formation reaction like Mukaiyama-Michael reaction under mild liquid phase conditions. The catalysts were synthesized by hydrothermal method at 383 K for 24-36 h in Teflon-lined autoclave and characterized thoroughly by XRD, UV-VIS, TEM, EPR, XPS, (27)Al NMR, NH(3)-TPD, pyridine-IR and AAS in order to obtain well-ordered M41S type materials. The Mukiayama-Michael reactions between silyl enol ether and alpha,beta-unsaturated ketones give Michael product in very good yields (100\% selectivity). The catalysts were reusable.

}, isbn = {978-0-444-53068-4}, issn = {0167-2991}, author = {Kalita, Pranjal and Kumar, Rajiv}, editor = {Xu, R and Gao, Z. and Chen, J and Yan, W} } @conference { ISI:000291657600157, title = {Chemoselective alkane oxidations by reactive superoxovanadium(V) species in vanadosilicate molecular sieves}, booktitle = {From ZEOLITES to Porous Mof Materials: The 40th Anniversary of International ZEOLITE Conference, Proceedings of The 15th International ZEOLITE Conference}, series = {Studies in Surface Science and Catalysis}, volume = {170}, year = {2007}, note = {15th International Zeolite Conference, Beijing, PEOPLES R CHINA, AUG 12-17, 2007}, month = {AUG}, pages = {1205-1212}, publisher = {Elsevier Science BV}, organization = {Elsevier Science BV}, address = {Sara Burgerhartstraat 25, Po Box 211, 1000 AE Amsterdam, Netherlands}, abstract = {

Unlike their titanium analogs, vanadosilicate molecular sieves catalyze the oxidation of the terminal (primary) C-H bonds in paraffins. This dissimilarity is attributed to differences in the type of reactive superoxo species generated on contact with oxidant. The latter were identified and characterized by in situ EPR and DRUV-vis spectroscopic techniques. By a suitable choice of silicate structure (VS-1 or V-MCM-41), solvent and oxidant (H(2)O(2), tert.-butyl hydroperoxide or H(2)+O2()), the V-O bond covalency and mode of O-O bond cleavage in the oxo-species and thereby, the chemoselectivity in the oxidation of the terminal carbon atoms in paraffins could be controlled.

}, isbn = {978-0-444-53068-4}, issn = {0167-2991}, author = {Srinivas, D. and Ratnasamy, P.}, editor = {Xu, R and Gao, Z. and Chen, J and Yan, W} } @conference { ISI:000291657600254, title = {Ethane bridged hybrid mesoporous silsesquioxanes with sulfonic acid functionalities: synthesis, characterization and catalytic applications}, booktitle = {From Zeolites to Porous Mof Materials: the 40th Anniversary of International Zeolite Conference, Proceedings of the 15th International Zeolite Conference}, series = {Studies in Surface Science and Catalysis}, volume = {170}, year = {2007}, note = {15th International Zeolite Conference, Beijing, PEOPLES R CHINA, AUG 12-17, 2007}, month = {AUG}, pages = {1899-1904}, publisher = {Elsevier Science BV}, organization = {Elsevier Science BV}, address = {Sara Burgerhartstraat 25, Po Box 211, 1000 AE Amsterdam, Netherlands}, abstract = {

Periodic mesoporous organosilicas having -CH(2)-CH(2)- groups in the framewall positions and sulfonic acid groups in the pore channels were prepared using 1,2-bis(triethoxysilyl) ethane, 3-mercaptopropyltriethoxysilane and cetyltrimethylammonium surfactant, under basic conditions, by a one-pot synthesis method. XRD, N(2) sorption isotherm and TEM analysis revealed that the mesoporous structural ordering is retained after the functionalization of organic groups while solid-state NMR techniques like (13)C CP MAS NMR and (29)Si MAS NMR show the presence of sulfonic acid groups and the stability of the mesoporous framework with integrated ethane moieties as bridging groups. The hybrid material was more active, selective and stable than the conventional sulfonic acid containing mesoporous catalysts in the Claisen-Schmidt condensation of acetophenone with benzaldehyde to form chalcone.

}, isbn = {978-0-444-53068-4}, issn = {0167-2991}, author = {Shylesh, S. and Samuel, Prinson P. and Parischa, Renu and Singh, A. P.}, editor = {Xu, R and Gao, Z. and Chen, J and Yan, W} } @conference { ISI:000291657600253, title = {Immobilization of Ntn hydrolases on APTES fuctionalized SBA-15}, booktitle = {From Zeolites to Porous Mof Materials: the 40th Anniversary of International Zeolite Conference, Proceedings of the 15th International Zeolite Conference}, series = {Studies in Surface Science and Catalysis}, volume = {170}, year = {2007}, note = {15th International Zeolite Conference, Beijing, PEOPLES R CHINA, AUG 12-17, 2007}, month = {AUG}, pages = {1891-1898}, publisher = {Elsevier Science BV}, organization = {Elsevier Science BV}, address = {Sara Burgerhartstraat 25, Po Box 211, 1000 AE Amsterdam, Netherlands}, abstract = {

APTES Functionalized mesoporous silica SBA-15 molecular sieves have been prepared and used for immobilization of Penicillin G acylase. Physico chemical characterization was done by nitrogen adsorption, powder XRD and TEM methods to understand the nature of immobilized PGA enzyme. XRD data indicate a good mesoscopic order. The characteristic hexagonal features of SBA-15 were maintained in PGA immobilized SBA-15 samples. Incorporation of PGA does not affect the original pore structure of the parent SBA-15. The adsorption of PGA on SBA-15 from buffered solutions with a pH value, 7.8 has been studied as a model protein adsorption system. The maximum activity of the immobilized enzyme was observed at pH 7.8, slightly below the isoelectric point of the enzyme. The loading capacity of immobilized PGA is 34 mg protein per 0.5 g of SBA-15. The stability of Penicillin G acylase was enhanced by the physical entrapment in SBA-15.

}, isbn = {978-0-444-53068-4}, issn = {0167-2991}, author = {Shah, Pallavi and Sridevi, N. and Prabhune, Asmita and Ramaswamy, Veda}, editor = {Xu, R and Gao, Z. and Chen, J and Yan, W} } @article {42614, title = {Lubrication effects on the flow of wet granular materials}, journal = {Physical Review E}, volume = {76}, year = {2007}, month = {APR}, pages = {Article No. 031302}, type = {Article}, abstract = {

We investigate the dynamics of a partially saturated grain-liquid mixture with a rotating drum apparatus. The drum is partially filled with the mixture and then rotated about its horizontal axis. We focus on the continuous avalanching regime and measure the impact of the volume fraction and viscosity of the liquid on the dynamic surface angle. The inclination angle of the surface is observed to increase sharply to a peak and then decrease as a function of liquid volume fraction. The height of the peak is observed to increase with rotation rate. For higher liquid volume fractions, the inclination angle of the surface can decrease with viscosity before increasing. The viscosity where the minimum occurs decreases with the rotation rate of the drum. Limited measurements of the flow depth were made, and these were observed to show only fractional changes with volume fraction and rotation speeds. We show that the qualitative features of our observations can be understood by analyzing the effect of lubrication forces on the time scale over which particles come in contact.

}, doi = {10.1103/PhysRevE.76.031302}, author = {Xu, Qing and Orpe, Ashish V. and Kudrolli, Arshad} } @proceedings { ISI:000291657600051, title = {Synthesis and characterization of value added catalysts zeolite beta using environmentally detrimental flyash}, volume = {170}, year = {2007}, note = {15th International Zeolite Conference, Beijing, PEOPLES R CHINA, AUG 12-17, 2007}, month = {AUG}, pages = {438-443}, publisher = {Elsevier Science BV}, address = {Beijing, Peoples R China}, abstract = {

Fly ash is a major byproduct of Thermal power plant, which makes a lot of pollution to the environment due to its fineness. When a large amount of fly ash is dumped in the places near to power plants, it mixes in all segment of environment like water, air as well as soil. Though it can be utilized for different useful purposes, due to the lack of technical knowledge about how and proper motivation, no progress has been made in its utilization. It has been demonstrated that the fly ash can be used for making a value added catalyst zeolite beta by using simple and low cost process. In the present paper it is demonstrated that the fly ash can be used as a source of silica and alumina in the synthesis of value added catalyst zeolite beta. Moreover, the influence of different silica sources such as tetraethylortho silicate, silica sol and fumed silica on the physiochemical characteristics of well crystallized zeolite beta was also studied. The detailed characterization was carried out by using powder XRD, (27)Al and (29)Si MAS NMR, chemical analysis and low temperature nitrogen adsorption. Based on the data obtained from various systems containing different silica source, fumed silica is found to be most efficient source materials and showed superiority in the uniformity of aluminum distribution and possesses higher surface area.

}, isbn = {978-0-444-53068-4}, issn = {0167-2991}, author = {Kasture, M. W. and Bokade, Vijay V. and Joshi, P. N. and Kumar, R.}, editor = {Xu, R and Gao, Z. and Chen, J and Yan, W} } @conference { ISI:000291657600173, title = {Tungstophosphoric acid and zirconia supported on mesoporous silica catalyst in veratrole acetylation}, booktitle = {From ZEOLITES to Porous Mof Materials: The 40th Anniversary of International ZEOLITE Conference, Proceedings of The 15th International ZEOLITE Conference}, series = {Studies in Surface Science and Catalysis}, volume = {170}, year = {2007}, note = {15th International Zeolite Conference, Beijing, PEOPLES R CHINA, AUG 12-17, 2007}, month = {AUG}, pages = {1325-1330}, publisher = {Elsevier Science BV}, organization = {Elsevier Science BV}, address = {Sara Burgerhartstraat 25, Po Box 211, 1000 AE Amsterdam, Netherlands}, abstract = {

Tungstophosphoric acid (TPA) over zirconia dispersed uniformly in mesoporous silica (MS) channels of MCM-41 and MCM-48 was synthesised and tested for its catalytic activity in veratrole acetylation. Catalysts with different TPA loadings (5 to 50 wt.\%) on 22.4 wt.\% ZrO(2)/MCM-41 and 15 wt.\% TPA on different zirconia loadings (10-70 wt.\%)/MCM-41 were prepared and calcined at 1123 K. Catalysts were characterised by known techniques. Mesoporous silica supports play an important role in stabilising catalytically active TPA along with tetragonal phase of zirconia. Among the catalysts, 15 wt.\% TPA/22.4 wt.\% ZrO(2)/MCM-41 calcined at 1123 K was found to have the highest acidity and be at least four times more active than neat 15 wt.\% TPA/ZrO(2) in veratrole acetylation to acetoveratrone by acetic anhydride.

}, isbn = {978-0-444-53068-4}, issn = {0167-2991}, author = {Halligudi, Shivaraj B.}, editor = {Xu, R. and Gao, Z. and Chen, J. and Yan, W.} } @article { ISI:000254416300010, title = {Enhanced shape anisotropy and magneto-optical birefringence by high energy ball milling in NixFe1-xFe2O4 ferrofluids}, journal = {Journal of Magnetism and Magnetic Materials}, volume = {320}, number = {6}, year = {2008}, month = {MAR}, pages = {815-820}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Ferrofluids belonging to the series NixFe1-xFe2O4 were synthesised by two different procedures-one by standard co-precipitation techniques, the other by co-precipitation for synthesis of particles and dispersion aided by high-energy ball milling with a view to understand the effect of strain and size anisotropy on the magneto-optical properties of ferrofluids. The birefringence measurements were carried out using a standard ellipsometer. The birefringence signal obtained for chemically synthesised samples was satisfactorily fitted to the standard second Langevin function. The ball-milled ferrofluids showed a deviation and their birefringence was enhanced by an order. This large enhancement in the birefringence value cannot be attributed to the increase in grain size of the samples, considering that the grain sizes of sample synthesised by both modes are comparable; instead, it can be attributed to the lattice strain-induced shape anisotropy(oblation) arising from the high-energy ball-milling process. Thus magnetic-optical (MO) signals can be tuned by ball-milling process, which can find potential applications. (C) 2007 Elsevier B.V. All rights reserved.

}, keywords = {birefringence, Co-precipitation, ferrofluid, HEBM}, issn = {0304-8853}, doi = {10.1016/j.jmmm.2007.08.032}, author = {Nair, Swapna S. and Xavier, Francis and Joy, Pattayil Alias and Kulkarni, S. D. and Anantharaman, Maliemadom R.} } @article {42757, title = {Functional delivery of siRNA in mice using dendriworms}, journal = {ACS Nano}, volume = {3}, year = {2009}, month = {SEP}, pages = {2495-2504}, doi = {10.1021/nn900201e}, author = {Agrawal, Amit C. and Min, Dal-Hee and Singh, Neetu and Zhu, Haihao and Birjiniuk, Alona and von Maltzahn, Geoffrey and Harris, Todd J. and Xing, Deyin and Woolfenden, Stephen D. and Sharp, Phillip A. and Charest, Alain and Bhatia, Sangeeta N.} } @article { ISI:000292059600022, title = {Influence of carbon-based nanofillers on the melt flow singularity of linear polyethylene}, journal = {Polymer}, volume = {52}, number = {14}, year = {2011}, month = {JUN}, pages = {3163-3174}, publisher = {ELSEVIER SCI LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND}, abstract = {

A quantitative power law relationship between molecular weight and flow criticalities is uncovered that links stick-slip theory with the melt flow singularity observed during capillary flow. The singularity arises from decrease in pressure during melt flow of linear polyethylene through capillary die in a narrow temperature window. The molecular origin of the window effect is attributed to slip flow arising from disengagement of chains adsorbed to melt-wall interface from free chains in melt. Considering the similar molecular configuration of the linear polyethylene and carbon nanotubes (CNTs), the stretched chain conformation of the adsorbed chains in the presence of CNTs is influenced. The potential to broaden the window temperature interval in the presence of CNTs is explored. For the study, multi-walled carbon nanotubes (MWCNTs) are added in the linear polyethylene. The influence of the filler aspect ratio on the window effect is further investigated in the presence of carbon black (CBs). The presence of MWCNTs broadens the window temperature interval and increases the decrease in pressure. Contrary to MWCNTs in the presence of CBs the extrusion window narrows and reduction in the pressure-decrease occurs. It is also found that the two carbon nanofillers have a significant impact on flow-induced solidification. Both, the crystallisation rate and the onset temperature of crystallisation, increase with the loading of the two nanofillers. A closer comparison between the two carbon nanofillers at the same loading suggests that the crystallisation is more influenced in MWCNT-PE composites. (C) 2011 Elsevier Ltd. All rights reserved.

}, keywords = {Capillary flow, Carbon fillers, Polyethylene}, issn = {0032-3861}, doi = {10.1016/j.polymer.2011.04.046}, author = {Xu, Han and Lele, Ashish K. and Rastogi, Sanjay} } @article { ISI:000317399600014, title = {Hydrophobic and hydrophilic balance and its effect on mesophase behaviour in hydroxyalkyl ethers of methyl glucopyranoside}, journal = {Chemistry-A European Journal}, volume = {19}, number = {16}, year = {2013}, month = {APR}, pages = {5041-5049}, publisher = {WILEY-V C H VERLAG GMBH}, address = {BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY}, abstract = {

Four series of monosubstituted methyl -D-glucopyranoside hydroxyalkyl ethers were prepared and their thermotropic and lyotropic self-organising properties were investigated in terms of the hydrophobichydrophilic balance with respect to their molecular structures. The results obtained lead us to a new understanding of the forces that drive the formation of condensed soft-matter phases.

}, keywords = {carbohydrates, liquid crystals, mesophases, Self-assembly, soft matter}, issn = {0947-6539}, doi = {10.1002/chem.201202933}, author = {Singh, Madan K. and Xu, Rui and Moebs, Sylvie and Kumar, Anil and Queneau, Yves and Cowling, Stephen J. and Goodby, John W.} } @article { ISI:000330542900022, title = {Sequential electrochemical unzipping of single-walled carbon nanotubes to graphene ribbons revealed by in situ Raman spectroscopy and imaging}, journal = {ACS Nano}, volume = {8}, number = {1}, year = {2014}, month = {JAN}, pages = {234-242}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

We report an in situ Raman spectroscopic and microscopic investigation of the electrochemical unzipping of single-walled carbon nanotubes (SWNTs). Observations of the radial breathing modes (RBMs) using Raman spectral mapping reveal that metallic SWNTs are opened up rapidly followed by gradual unzipping of semiconducting SWNTs. Consideration of the resonant Raman scattering theory suggests that two metallic SWNTs with chiralities (10,4) and (12, 0) get unzipped first at a lower electrode potential (036 V) followed by the gradual unzipping of another two metallic tubes, (9, 3) and (10, 1), at a relatively higher potential (1.16 V). The semiconducting SWNTs with chiralities (11, 7) and (12, 5), however, get open up gradually at +/- 1.66 V. A rapid decrease followed by a subsequent gradual decrease in the metallicity of the SWNT ensemble as revealed from a remarkable variation of the peak width of the G band complies well with the variations of RBM. Cyclic voltammetry also gives direct evidence for unzipping in terms of improved capacitance after oxidation followed by more important removal of oxygen functionalities during the reduction step, as reflected in subtle changes of the morphology confirming the formation of graphene nanoribbons. The density functional-based tight binding calculations show additional dependence of chirality and diameter of nanotubes on the epoxide binding energies, which is in agreement with the Raman spectroscopic results and suggests a possible mechanism of unzipping determined by combined effects of the structural characteristics of SWNTs and applied field.

}, keywords = {density functional-based tight binding calculations, Electrochemistry, graphene, Raman spectral mapping, single-walled carbon nanotubes}, issn = {1936-0851}, doi = {10.1021/nn403289g}, author = {John, Robin and Shinde, Dhanraj B. and Liu, Lili and Ding, Feng and Xu, Zhiping and Vijayan, Cherianath and Pillai, Vijayamohanan K. and Pradeep, Thalappil} } @article {45446, title = { Glycolysis is important for optimal asexual growth and formation of mature tissue cysts by Toxoplasma gondii}, journal = {International Journal for Parasitology }, volume = {48}, year = {2018}, month = {OCT}, pages = {955-968}, type = {Article}, abstract = {Toxoplasma gondii can grow and replicate using either glucose or glutamine as the major carbon source. Here, we have studied the essentiality of glycolysis in the tachyzoite and bradyzoite stages of T. gondii, using transgenic parasites that lack a functional hexokinase gene (Delta hk) in RH (Type-1) and Prugniaud (Type-II) strain parasites. Tachyzoite stage 411k parasites exhibit a fitness defect similar to that reported previously for the major glucose transporter mutant, and remain virulent in mice. However, although Prugniaud strain Delta hk tachyzoites were capable of transforming into bradyzoites in vitro, they were severely compromised in their ability to make mature bradyzoite cysts in the brain tissue of mice. Isotopic labelling studies reveal that glucose-deprived tacyzoites utilise glutamine to replenish glycolytic and pentose phosphate pathway intermediates via gluconeogenesis. Interestingly, while glutaminedeprived intracellular Delta hk tachyzoites continued to replicate, extracellular parasites were unable to efficiently invade host cells. Further, studies on mutant tachyzoites lacking a functional phosphoenolpyruvate carboxykinase (Delta pepck1) revealed that glutaminolysis is the sole source of gluconeogenic flux in glucose-deprived parasites. In addition, glutaminolysis is essential for sustaining oxidative phosphorylation in zihk parasites, while wild type (wt) and Delta pepck1 parasites can obtain ATP from either glycolysis or oxidative phosphorylation. This study provides insights into the role of nutrient metabolism during asexual propagation and development of T. gondii, and validates the versatile nature of central carbon and energy metabolism in this parasite. (C) 2018 Australian Society for Parasitology. Published by Elsevier Ltd. All rights reserved.}, issn = { 0020-7519}, doi = {10.1016/j.ijpara.2018.05.013}, author = {Shukla, Anurag and Olszewski, Kellen L. and Llinas, Manuel and Rommereim, Leah M. and Fox, Barbara A. and Bzik, David J. and Xia, Dong and Wastling, Jonathan and Beiting, Daniel and Roos, David S. and Shanmugam, Dhanasekaran} } @article {44643, title = {Repeated photoporation with graphene quantum dots enables homogeneous labeling of live cells with extrinsic markers for fluorescence microscopy}, journal = {Light-Science \& Applications}, volume = {7}, year = {2018}, month = {AUG}, pages = {47}, abstract = {

In the replacement of genetic probes, there is increasing interest in labeling living cells with high-quality extrinsic labels, which avoid over-expression artifacts and are available in a wide spectral range. This calls for a broadly applicable technology that can deliver such labels unambiguously to the cytosol of living cells. Here, we demonstrate that nanoparticle-sensitized photoporation can be used to this end as an emerging intracellular delivery technique. We replace the traditionally used gold nanoparticles with graphene nanoparticles as photothermal sensitizers to permeabilize the cell membrane upon laser irradiation. We demonstrate that the enhanced thermal stability of graphene quantum dots allows the formation of multiple vapor nanobubbles upon irradiation with short laser pulses, allowing the delivery of a variety of extrinsic cell labels efficiently and homogeneously into live cells. We demonstrate high-quality time-lapse imaging with confocal, total internal reflection fluorescence (TIRF), and Airyscan super-resolution microscopy. As the entire procedure is readily compatible with fluorescence (super resolution) microscopy, photoporation with graphene quantum dots has the potential to become the long-awaited generic platform for controlled intracellular delivery of fluorescent labels for live-cell imaging.

}, issn = {2047-7538}, doi = {10.1038/s41377-018-0048-3}, author = {Liu, Jing and Xiong, Ranhua and Brans, Toon and Lippens, Saskia and Parthoens, Eef and Zanacchi, Francesca Cella and Magrassi, Raffaella and Singh, Santosh K. and Kurungot, Sreekumar and Szunerits, Sabine and Bove, Hannelore and Ameloot, Marcel and Fraire, Juan C. and Teirlinck, Eline and Samal, Sangram Keshari and De Rycke, Riet and Houthaeve, Gaelle and De Smedt, Stefaan C. and Boukherroub, Rabah and Braeckmans, Kevin} } @article {46850, title = {Functionalized magnetic nanosized materials for efficient biodiesel synthesis via acid-base/enzyme catalysis}, journal = {Green Chemistry}, volume = {22}, year = {2020}, month = {MAY}, pages = {2977-3012}, type = {Review}, abstract = {

According to the principles of green chemistry, the rapid recovery and reuse of catalysts after a catalytic reaction are important factors to realize the sustainable management of chemical production processes. The functionalization of magnetic nanoparticles is the basis for the efficient separation of heterogeneous catalysts from the reaction system by using the magnetic separation technology as well as for effectively bridging heterogeneous and homogeneous catalytic processes. This can considerably improve the production efficiency and reduce energy consumption as well. Owing to important applications as a potential biofuel or fuel additive, the synthesis of biodiesel mainly from low-cost biomass feedstocks has received considerable attention in the current biorefinery research. A simple synthesis process coupled with the application of functionalized magnetic catalysts can remarkably reduce the production cost and minimize waste generation, thereby promoting the potential development of green catalytic processes for the large-scale synthesis of biodiesel. In this review, the preparation methods, structural and performance control, and protection and functionalization of magnetic nanoparticles as well as the consequent catalytic effects in the synthesis of biodiesel (mainly long-chain fatty acid methyl esters) have been reported. In addition, various representative reaction mechanisms are discussed, emphasizing the existing challenges and prospects of industrialization.

}, issn = {1463-9262}, doi = {10.1039/d0gc00924e}, author = {Wang, Anping and Sudarsanam, Putla and Xu, Yufei and Zhang, Heng and Li, Hu and Yang, Song} } @article {46878, title = {Whole-cell phenotypic screening of medicines for malaria venture pathogen box identifies specific inhibitors of plasmodium falciparum late-stage development and egress}, journal = {Antimicrobial Agents and Chemotherapy}, volume = {64}, year = {2020}, month = {MAY}, pages = {e01802-19}, type = {Article}, abstract = {

We report a systematic, cellular phenotype-based antimalarial screening of the Medicines for Malaria Venture Pathogen Box collection, which facilitated the identification of specific blockers of late-stage intraerythrocytic development of Plasmodium falciparum. First, from standard growth inhibition assays, we identified 173 molecules with antimalarial activity (50\% effective concentration [EC50] \<= 10 mu M), which included 62 additional molecules over previously known antimalarial candidates from the Pathogen Box. We identified 90 molecules with EC50 of \<= 1 mu M, which had significant effect on the ring-trophozoite transition, while 9 molecules inhibited the trophozoite-schizont transition and 21 molecules inhibited the schizontring transition (with \>= 50\% parasites failing to proceed to the next stage) at 1 mu M. We therefore rescreened all 173 molecules and validated hits in microscopy to prioritize 12 hits as selective blockers of the schizont-ring transition. Seven of these molecules inhibited the calcium ionophore-induced egress of Toxoplasma gondii, a related apicomplexan parasite, suggesting that the inhibitors may be acting via a conserved mechanism which could be further exploited for target identification studies. We demonstrate that two molecules, MMV020670 and MMV026356, identified as schizont inhibitors in our screens, induce the fragmentation of DNA in merozoites, thereby impairing their ability to egress and invade. Further mechanistic studies would facilitate the therapeutic exploitation of these molecules as broadly active inhibitors targeting late-stage development and egress of apicomplexan parasites relevant to human health.

}, keywords = {DNA fragmentation, egress, Medicines for Malaria Venture, MMV, Pathogen Box, phenotypic screening, Plasmodium falciparum, schizonts, stage-specific inhibition}, issn = {0066-4804}, doi = {10.1128/AAC.01802-19}, author = {Patra, Alok Tanala and Hingamire, Tejashri and Belekar, Meenakshi A. and Xiong, Aoli and Subramanian, Gowtham and Bozdech, Zbynek and Preiser, Peter and Shanmugam, Dhanasekaran and Chandramohanadas, Rajesh} } @article {47068, title = {Operando generated ordered heterogeneous catalyst for the selective conversion of CO2 to methanol}, journal = {ACS Energy Letters}, volume = {6}, year = {2021}, month = {FEB }, pages = {509-516}, type = {Article}, abstract = {

The discovery of new materials for efficient transformation of carbon dioxide (CO2) into desired fuel can revolutionize large-scale renewable energy storage and mitigate environmental damage due to carbon emissions. In this work, we discovered an operando generated stable Ni-In kinetic phase that selectively converts CO2 to methanol (CTM) at low pressure compared to the state-of-the-art materials. The catalytic nature of a well-known methanation catalyst, nickel, has been tuned with the introduction of inactive indium, which enhances the CTM process. The remarkable change in the mechanistic pathways toward methanol production has been mapped by operando diffuse reflectance infrared Fourier transform spectroscopy analysis, corroborated by first-principles calculations. The ordered arrangement and pronounced electronegativity difference between metals are attributed to the complete shift in mechanism. The approach and findings of this work provide a unique advance toward the next-generation catalyst discovery for going beyond the state-of-the-art in CO2 reduction technologies.

}, issn = {2380-8195}, doi = {10.1021/acsenergylett.0c02614}, author = {Cherevotan, Arjun and Raj, Jithu and Dheer, Lakshay and Roy, Soumyabrata and Sarkar, Shreya and Das, Risov and Vinod, Chathakudath P. and Xu, Shaojun and Wells, Peter and Waghmare, V, Umesh and Peter, Sebastian C.} } @article {48199, title = {Understanding the effect of sodium polyphosphate on improving the chemical stability of Ti3C2Tz MXene in water}, journal = {Journal of Materials Chemistry A}, volume = {10}, year = {2022}, month = {OCT }, pages = {22016-22024}, type = {Article}, abstract = {

Degradation of MXenes in aqueous environments severely limits the application and industrialization of this large family of two-dimensional (2D) materials. Hydrolysis and oxidation are now considered as two main degradation mechanisms and while significant efforts have been directed to prolonging the shelf-life of MXenes, separating and studying their degradation mechanisms have lagged behind. Herein, gas analysis via gas chromatography and Raman spectroscopy were used to investigate the effect of sodium polyphosphate, PP, on the degradation of Ti3C2Tz MXene. Transmission and scanning electron microscopies, as well as X-ray photoelectron spectroscopywere also used as complimentary techniques to support conclusions derived from gas analysis and to confirm the extent of degradation via characterization of solid reaction products. Based on these studies we have determined that the addition of PP to an equal mass of Ti3C2Tz solution can effectively suppress hydrolysis and protect Ti3C2Tz from degradation.

}, issn = {2050-7488}, doi = {10.1039/d2ta04009c}, author = {Huang, Shuohan and Natu, Varun and Tao, Jingyi and Xia, Yumin and Mochalin, Vadym N. and Barsoum, Michel W.} }