Adsorptive removal of benzothiophene using porous copper-benzenetricarboxylate loaded with phosphotungstic acid

Khan, N.A.,Jhung, S.H. Elsevier Scientific Pub. Co 2012 Fuel processing technology Vol.100 No.-

Liquid-phase adsorption of benzothiophene (BT) over phosphotungstic acid (PWA)-loaded porous copper-benzenetricarboxylate (Cu-BTC, one of the porous metal-organic frameworks) has been studied to understand the effect of PWAs on the adsorption/removal. The maximum adsorption capacity (Q<SUB>0</SUB>) increases with increasing PWA loading up to a W/Cu (wt./wt.) ratio of 0.22 in PWA/Cu-BTCs, resulting in an increase in the Q<SUB>0</SUB> by 26% compared with the virgin Cu-BTC. Since there is no remarkable change in the surface area and pore volume for the virgin and PWA loaded Cu-BTCs, it is suggested that the improved Q<SUB>0</SUB> over PWA/Cu-BTCs is due to the favorable interactions like acid-base ones between the acidic PWA and slightly basic BT. Based on this result, it can be suggested that MOF (metal-organic framework)-type materials, modified suitably, can be used in the adsorptive desulfurization of fuels.

Adsorptive removal of hazardous materials using metal-organic frameworks (MOFs): A review

Khan, N.A.,Hasan, Z.,Jhung, S.H. Elsevier Scientific Pub. Co 2013 Journal of hazardous materials Vol.244 No.-

Efficient removal of hazardous materials from the environment has become an important issue from a biological and environmental standpoint. Adsorptive removal of toxic components from fuel, waste-water or air is one of the most attractive approaches for cleaning technologies. Recently, porous metal-organic framework (MOF) materials have been very promising in the adsorption/separation of various liquids and gases due to their unique characteristics. This review summarizes the recent literatures on the adsorptive removal of various hazardous compounds mainly from fuel, water, and air by virgin or modified MOF materials. Possible interactions between the adsorbates and active adsorption sites of the MOFs will be also discussed to understand the adsorption mechanism. Most of the observed results can be explained with the following mechanisms: (1) adsorption onto a coordinatively unsaturated site, (2) adsorption via acid-base interaction, (3) adsorption via π-complex formation, (4) adsorption via hydrogen bonding, (5) adsorption via electrostatic interaction, and (6) adsorption based on the breathing properties of some MOFs and so on.

Effect of central metal ions of analogous metal-organic frameworks on the adsorptive removal of benzothiophene from a model fuel

Khan, N.A.,Jhung, S.H. Elsevier Scientific Pub. Co 2013 Journal of hazardous materials Vol.260 No.-

Liquid phase adsorption of benzothiophene (BT) has been studied over CuCl<SUB>2</SUB>-loaded analogous metal-organic frameworks (MOFs), metal-benzenedicarboxylates (Me-BDCs, Me: Al, Cr and V), to understand the effect of central metal ions on the adsorptive removal of BT from a model fuel. Among the central metal ions (Al<SUP>3+</SUP>, Cr<SUP>3+</SUP> and V<SUP>3+</SUP>) of the Me-BDCs only V<SUP>3+</SUP> was oxidized by the loaded CuCl<SUB>2</SUB> (or Cu<SUP>2+</SUP>) at ambient condition resulting in V<SUP>4+</SUP> and Cu<SUP>+</SUP> species. Different from the CuCl<SUB>2</SUB>-loaded Al- and Cr-BDCs, the CuCl<SUB>2</SUB>/V-BDC adsorbed BT remarkably well compared to the virgin V-BDCs which suggests a speci@?c favorable interaction (π-complexation) between the obtained Cu<SUP>+</SUP> in the CuCl<SUB>2</SUB>/V-BDC and BT.

Low-temperature loading of Cu⁺ species over porous metal-organic frameworks (MOFs) and adsorptive desulfurization with Cu⁺-loaded MOFs

Khan, N.A.,Jhung, S.H. Elsevier Scientific Pub. Co 2012 Journal of hazardous materials Vol.237 No.-

Porous metal-organic frameworks (MOFs, MIL-100-Fe, iron-benzenetricarboxylate) supported with Cu<SUP>+</SUP> species were obtained for the first time under mild condition without high temperature calcinations. The Cu<SUP>+</SUP>-loaded MOFs were evaluated as efficient adsorbents for the liquid-phase adsorption of benzothiophene (BT). The effect of Cu<SUP>+</SUP> loading on the adsorption kinetics and maximum adsorption capacity (Q<SUB>0</SUB>) for the adsorption of BT was also studied. Q<SUB>0</SUB> increased with increasing copper loading up to a Cu/Fe (wt./wt.) ratio of 0.07 in Cu<SUP>+</SUP>-loaded-MIL-100-Fe, resulting in an increase in the Q<SUB>0</SUB> by 14% compared with the virgin MIL-100-Fe without Cu<SUP>+</SUP> ions. Since the surface area and pore volume decrease with the loading of copper, the increased Q<SUB>0</SUB> over the Cu<SUP>+</SUP>-loaded MIL-100-Fe adsorbents suggests specific favorable interactions (probably by π-complexation) between Cu<SUP>+</SUP> and BT.

Liquid-phase dehydration of sorbitol under microwave irradiation in the presence of acidic resin catalysts

Khan, N. A.,Mishra, D. K.,Hwang, J. S.,Kwak, Y. W.,Jhung, S. H. VSP 2011 Research on chemical intermediates Vol.37 No.9

Synthesis of metal-organic frameworks (MOFs) with microwave or ultrasound: Rapid reaction, phase-selectivity, and size reduction

Khan, N.A.,Jhung, S.H. Elsevier Publishing Company 2015 Coordination chemistry reviews Vol.285 No.-

Microwave (MW) and ultrasonic (US) irradiation are the most simple, inexpensive, and efficient nonconventional heating methods available in applied chemistry. Both techniques are well established in the field of organic transformations/syntheses, even though the utilization of alternative methods in the synthesis of emerging materials, including inorganic nanomaterials, nanoporous materials, and hybrid materials, is rapidly materializing. The rapidly growing number of publications regarding the synthesis of such materials via MW and US irradiation clearly suggests that these techniques will play a role in materials chemistry. In this review, we have given an overview of the synthesis of porous metal-organic frameworks (MOFs) materials with MW and US irradiation. MOFs are very interesting materials due to their various potential applications. This review is not meant to serve as a thorough overview of MW- or US-assisted synthesis of MOFs, but is meant to describe the degree of acceleration, phase-selective crystallization, and crystal size reduction in MOF synthesis. Considering these particular aspects of MOF synthesis, the advantages of MW or US irradiation compared with conventional heating have been expounded in detail.

Vascular Endothelial Growth Factor Levels in Relation to Oxidative Damage and Antioxidant Status in Patients with Breast Cancer

Deepti Pande,Reena Negi,Seema Khanna,Ranjana Khanna,Hari D. Khanna 한국유방암학회 2011 Journal of breast cancer Vol.14 No.3

Purpose: Oxidative stress and angiogenesis are important elements in the pathogenesis of inflammatory diseases and cancer. Vascular endothelial growth factor (VEGF) is one of the most potent angiogenic cytokines and is up-regulated by conditions associated with the generation of free radicals and reactive oxygen intermediates. In this study, we investigated the association between oxidative stress and serum VEGF status in patients with breast cancer. Methods: Forty patients with breast carcinoma, of which 21 were stage II and 19 were stage III, along with 40 ageand gender-matched healthy controls were enrolled. Oxidative stress, total antioxidant status, and VEGF levels in serum were evaluated by spectrophotometric procedures. Malondialdehyde (MDA) levels were measured and antioxidant status was assessed by measuring total antioxidant status (TAS) to assess oxidative damage. Results: VEGF and MDA levels were significantly higher in patients with breast cancer than those of controls (p<0.005). Total antioxidant level decreased significantly in patients compared to that in controls. MDA, TAS, and VEGF levels were also analyzed based on menopausal status and different clinical disease stages. MDA and TAS level significantly different in the postmenopausal group than the premenopausal group, whereas VEGF level remained unchanged. Conclusion: Increased VEGF level and its positive correlation with oxidative stress level and decreased antioxidant status suggest a link between oxidative stress and malignant transformation.

A Proteomic Screen for Presynaptic Terminal N-type Calcium Channel (CaV2.2) Binding Partners

Khanna, Rajesh,Zougman, Alexandre,Stanley, Elise F. Korean Society for Biochemistry and Molecular Biol 2007 Journal of biochemistry and molecular biology Vol.40 No.3

N type calcium channels (CaV2.2) play a key role in the gating of transmitter release at presynaptic nerve terminals. These channels are generally regarded as parts of a multimolecular complex that can modulate their open probability and ensure their location near the vesicle docking and fusion sites. However, the proteins that comprise this component remain poorly characterized. We have carried out the first open screen of presynaptic CaV2.2 complex members by an antibody-mediated capture of the channel from purified rat brain synaptosome lysate followed by mass spectroscopy. 589 unique peptides resulted in a high confidence match of 104 total proteins and 40 synaptosome proteome proteins. This screen identified several known CaV2.2 interacting proteins including syntaxin 1, VAMP, protein phosphatase 2A, $G_{o\alpha}$, G$\beta$ and spectrin and also a number of novel proteins, including clathrin, adaptin, dynamin, dynein, NSF and actin. The unexpected proteins were classified within a number of functional classes that include exocytosis, endocytosis, cytoplasmic matrix, modulators, chaperones, and cell-signaling molecules and this list was contrasted to previous reports that catalogue the synaptosome proteome. The failure to detect any postsynaptic density proteins suggests that the channel itself does not exhibit stable trans-synaptic attachments. Our results suggest that the channel is anchored to a cytoplasmic matrix related to the previously described particle web.

ADDITIONAL GENERATING RELATIONS FOR CLASSICAL POLYNOMIALS

Khanna, I.K. Department of Mathematics 1977 Kyungpook mathematical journal Vol.17 No.2

Polygenic Risk Score for Cardiovascular Diseases in Artificial Intelligence Paradigm: A Review

Khanna Narendra N,Singh Manasvi,Maindarkar Mahesh,Kumar Ashish,Johri Amer M.,Mentella Laura,Laird John R,Paraskevas Kosmas I.,Ruzsa Zoltan,Singh Narpinder,Kalra Mannudeep K.,Fernandes Jose Fernandes E 대한의학회 2023 Journal of Korean medical science Vol.38 No.46

Cardiovascular disease (CVD) related mortality and morbidity heavily strain society. The relationship between external risk factors and our genetics have not been well established. It is widely acknowledged that environmental influence and individual behaviours play a significant role in CVD vulnerability, leading to the development of polygenic risk scores (PRS). We employed the PRISMA search method to locate pertinent research and literature to extensively review artificial intelligence (AI)-based PRS models for CVD risk prediction. Furthermore, we analyzed and compared conventional vs. AI-based solutions for PRS. We summarized the recent advances in our understanding of the use of AI-based PRS for risk prediction of CVD. Our study proposes three hypotheses: i) Multiple genetic variations and risk factors can be incorporated into AI-based PRS to improve the accuracy of CVD risk predicting. ii) AI-based PRS for CVD circumvents the drawbacks of conventional PRS calculators by incorporating a larger variety of genetic and non-genetic components, allowing for more precise and individualised risk estimations. iii) Using AI approaches, it is possible to significantly reduce the dimensionality of huge genomic datasets, resulting in more accurate and effective disease risk prediction models. Our study highlighted that the AI-PRS model outperformed traditional PRS calculators in predicting CVD risk. Furthermore, using AI-based methods to calculate PRS may increase the precision of risk predictions for CVD and have significant ramifications for individualized prevention and treatment plans.