Engineered islet cell clusters transplanted into subcutaneous space are superior to pancreatic islets in diabetes

Pathak, Shiva,Regmi, Shobha,Gupta, Biki,Pham, Tung Thanh,Yong, Chul Soon,Kim, Jong Oh,Yook, Simmyung,Kim, Jae-Ryong,Park, Min Hui,Bae, Young Kyung,Jeong, Jee-Heon Federation of American Societies for Experimental 2017 The FASEB Journal Vol. No.

<P>An alternative route for pancreatic islet transplantation is the subcutaneous space; however, inadequate vascularization in the subcutaneous space limits the availability of oxygen and nutrients to the subcutaneously transplanted islets, which leads to the development of a necrotic core in the islets, thereby causing islet dysfunction. Thus, we aimed to prevent the early apoptosis of pancreatic islets after transplantation into subcutaneous space by preparing islet clusters of appropriate size. We prepared fully functional islet cell clusters (ICCs) by using the hanging-drop technique. We optimized the size of ICCs on the basis of viability and functionality after culture in an hypoxic environment. We transplanted ICCs into the subcutaneous space of diabetic mice and evaluated the viability of the islets at the transplantation site. In an hypoxic environment, ICCs exhibited improved viability and functionality compared with control islets. ICCs, upon transplantation into the hypoxic subcutaneous space of diabetic mice, showed better glycemic control compared with control islets. Live/dead imaging of the islets after retrieval fromthe transplanted area revealed significantly reduced apoptosis in ICCs. Transplantation of ICCsmay be an attractive strategy to prevent islet cell apoptosis that results from nonimmune-mediated physiologic stress at the transplantation site.-Pathak, S., Regmi, S., Gupta, B., Pham, T. T., Yong, C. S., Kim, J. O., Yook, S., Kim, J.-R., Park, M. H., Bae, Y. K., Jeong, J.-H. Engineeredislet cell clusters transplanted into subcutaneous space are superior to pancreatic islets in diabetes.</P>

Narrowband ultraviolet B emitting Gd doped CaAl₂O₄ phosphors – An ESR and photoluminescence study

Pathak, M.S.,Singh, N.,Singh, Vijay,Watanabe, S.,Gundu Rao, T.K.,Seshadri, M.,Lee, Jung-Kul Elsevier 2018 Journal of luminescence Vol.204 No.-

<P><B>Abstract</B></P> <P>Phosphors with the composition Ca<SUB>1-x</SUB>Gd<SUB>x</SUB>Al<SUB>2</SUB>O<SUB>4</SUB> (x = 0.0025–0.09) were synthesized by a simple combustion route in a short time. The formation of the as-prepared combustion products was confirmed by the X-ray diffraction analysis, indicating the formation of a monoclinic phase. The PL spectroscopy assessment shows that with increasing Gd<SUP>3+</SUP> concentration, the ultraviolet emission from Gd<SUP>3+</SUP> at 314 nm (<SUP>6</SUP>P<SUB>7/2</SUB>→<SUP>8</SUP>S<SUB>7/2</SUB>) progressively enhanced. The Gd<SUP>3+</SUP>-doped CaAl<SUB>2</SUB>O<SUB>4</SUB> displays electron spin resonance signals with the effective g values at <I>g</I> ≈ 1.95, 2.9, and 3.7. Additional lines were also observed at the approximate g values of ~2.2 and 5.3. Gd<SUP>3+</SUP> ion located in the distorted surroundings and experiencing relatively strong crystal field, give rise to low field lines. Distorted surroundings in the present system may result from the nearness of the charge compensator oxygen vacancies.</P>

Feasibility of Bioleaching in Removing Metals (Al, Ni, V and Mo) from as Received Raw Petroleum Spent Refinery Catalyst: A Comparative Study on Leaching Yields, Risk Assessment Code and Reduced Partition Index

Pathak, Ashish,Srichandan, Haragobinda,Kim, Dong-Jin JAPAN INSTITUTE OF METALS 2015 MATERIALS TRANSACTIONS Vol.56 No.8

Laser dynamics in transversely inhomogeneous plasma and its relevance to wakefield acceleration

Pathak, V B,Vieira, J,Silva, L O,Nam, Chang Hee IOP 2018 Plasma physics and controlled fusion Vol.60 No.5

<P>We present full set of coupled equations describing the weakly relativistic dynamics of a laser in a plasma with transverse inhomogeneity. We apply variational principle approach to obtain these coupled equations governing laser spot-size, transverse wavenumber, curvature, transverse centroid, etc. We observe that such plasma inhomogeneity can lead to stronger self-focusing. We further discuss the guiding conditions of laser in parabolic plasma channels. With the help of multi-dimensional particle in cell simulations the study is extended to the blowout regime of laser wakefield acceleration to show laser as well as self-injected electron bunch steering in plasma to generate unconventional particle trajectories. Our simulation results demonstrate that such transverse inhomogeneities due to asymmetric self focusing lead to asymmetric bubble excitation, thus inducing off-axis self-injection.</P>

Hydrometallurgical recycling of critical metals from spent Ni-Cd batteries with emphasis on the separation of Cd2+ over Ni2+ using D2EHPA

Pathak Pankaj,Pandey Nidhi 한국자원공학회 2023 Geosystem engineering Vol.26 No.5

The present study is comprised of a hydrometallurgical process investigated for the recovery of critical metals viz. nickel (Ni) and cadmium (Cd) from spent Ni-Cd batteries with a focus on solvent extraction of Cd-ions. The leaching performed at 5 (w/v)% pulp density using 2.0 M H2SO4 with 7 (v/v)% H2O2 for 6 h duration at 90°C yielded the maximum leaching efficiency of >91% Ni and >99% Cd along with a significant quantity of Fe (>87%). Iron was subjected to hydrolytic precipitation to its complete removal (below 10 ppm in the solution) from the leach liquor at a pH of ~3.5. After that, the Ni-Cd-containing solution was contacted with di-(2-ethylhexyl) phosphoric acid (D2EHPA) to study the extraction behavior as a function of extractant concentration, equilibrium pH, and organic-to-aqueous (O:A) phase ratio. At an equilibrium pH of 3.3, a significant quantity of Ni (>18%) was co-extracted with ~73% Cd by contacting 20 (v/v)% D2EHPA, which was completely scrubbed by contacting 15 g/L CdSO4 solution at an O:A ratio of 2. The scrubbed organic containing 14.4 g/L Cd was then recovered by stripping with 1.5 M H2SO4 solution at an O: A ratio of 1, yielding >99% Cd into the aqueous phase. Further, Ni was recovered from the raffinate by adding soda ash at Na2CO3:Ni2+ ratio = 2.5, temperature = 50°C, and time = 1 h, which was analyzed to be NiCO3.2Ni(OH)2 with purity >99.9%. The experimental results showed the potential of hydrometallurgical tools for the recovery of critical metals from spent Ni-Cd batteries.

Fractionation Behavior of Metals (Al, Ni, V, and Mo) During Bioleaching and Chemical Leaching of Spent Petroleum Refinery Catalyst

Pathak, Ashish,Srichandan, Haragobinda,Kim, Dong-Jin Springer-Verlag 2014 Water, Air and Soil Pollution Vol.225 No.3

Synthesis and investigations on correlation between EPR and optical properties of Fe doped Li₂SiO₃

Pathak, M.S.,Gopal, N.O.,Singh, N.,Mohapatra, M.,Rao, J.L.,Lee, Jung-Kul,Singh, Vijay Elsevier 2018 Journal of non-crystalline solids Vol.500 No.-

<P><B>Abstract</B></P> <P>Iron doped lithium metasilicate sample was synthesized using a combustion technique and characterized by XRD (X ray diffraction), SEM (scanning electron microscopy), FTIR (Fourier transform infrared spectroscopy), optical, and EPR (electron paramagnetic resonance) analyses. The phase purity of the combustion synthesized products was confirmed by XRD analysis. SEM data suggested the formation of a porous compound by virtue of the entrapment of the gases that evolved during the sample synthesis. FTIR data confirmed the formation of SiO bonds in the system. Optical data confirmed the existence of both divalent and trivalent iron in the system. Characteristic absorption bands in the region 215–270 nm and 535–620 nm were observed due to the presence of Fe<SUP>3+</SUP> in Oh and Td geometry respectively. On the other hand, the presence of bands at 967 and 1442 nm suggested the stabilisation of Fe<SUP>2+</SUP> also in both Oh and Td geometries, respectively. The divalent iron being a non-Kramer ion, could not be observed by EPR. However, strong temperature-dependent EPR signals were observed in the sample owing to Fe<SUP>3+</SUP>. By analyzing the EPR data, super-paramagnetic type of behaviour was observed in the system. Furthermore, the relaxation times along with other EPR spectroscopic parameters were estimated for the system.</P>

Hybrid Congregation of Islet Single Cells and Curcumin-Loaded Polymeric Microspheres as an Interventional Strategy to Overcome Apoptosis Associated with Pancreatic Islets Transplantation

Pathak, Shiva,Regmi, Shobha,Gupta, Biki,Poudel, Bijay K.,Pham, Tung Thanh,Kim, Jae-Ryong,Park, Pil-Hoon,Yong, Chul Soon,Kim, Jong Oh,Bae, Young Kyung,Kim, Sang Kyoon,Jeong, Jee-Heon American Chemical Society 2016 ACS APPLIED MATERIALS & INTERFACES Vol.8 No.39

<P>Hypoxic or near-anoxic conditions that occur in the core of transplanted islets induce necrosis and apoptosis during the early stages after transplantation, primarily due to loss of vascularization during the isolation process. Moreover, secretion of various cytokines from pancreatic islets is detrimental to the viability of islet cells in vitro. In this study, we aimed to protect pancreatic islet cells against apoptosis by establishing a method for in situ delivery of curcumin to the pancreatic islets. Self-assembled heterospheroids composed of pancreatic islet cells and curcumin-loaded polymeric micro spheres were prepared by the three-dimensional cell culture technique. Release of curcumin in the microenvironment of pancreatic islets promoted survival of the islets. In hypoxic culture conditions, which mimic the in vivo conditions after transplantation, viability of the islets was significantly improved, as indicated by a decreased expression of pro-apoptotic protein and an increased expression of anti-apoptotic protein. Additionally, oxidative stress-induced cell death was suppressed. Thus, unlike co-transplantation of pancreatic islets and free microspheres, which provided a wide distribution of microspheres throughout the transplanted area, the heterospheroid transplantation resulted in colocalization of pancreatic islet cells and microspheres, thereby exerting beneficial effects on the cells.</P>

Influence of Dietary Supplementation of Condensed Tannins through Leaf Meal Mixture on Intake, Nutrient Utilization and Performance of Haemonchus contortus Infected Sheep

Pathak, A.K.,Dutta, Narayan,Banerjee, P.S.,Pattanaik, A.K.,Sharma, K. Asian Australasian Association of Animal Productio 2013 Animal Bioscience Vol.26 No.10

The study assessed the effect of dietary supplementation of leaf meal mixture (LMM) containing condensed tannins (CT) on feed intake, nutrient utilization and performance of sheep infected with Haemonchus contortus. Eighteen adult sheep of similar age and body weight ($25.03{\pm}1.52$) were included in this study and out of these, 12 sheep were infected with single dose of infective third stage larvae of H. contortus at 2,000 larvae per sheep. The experimental sheep were allocated in three different groups' i.e. negative control (NC; no infection), control (C; H. contortus infected) and treatment (T; H. contortus infected+CT at 1.5% of the DM through LMM) and the experiment was conducted for a period of 90 d. The intake of dry matter (DM), organic matter (OM) and digestibility of DM, OM, neutral detergent fibre (NDF) and acid detergent fibre (ADF) were comparable among three animal groups. However, digestibility of crude protein (CP) and ether extract (EE) were significantly (p<0.05) higher in NC group as compared to both C and T groups. Nitrogen (N) retention (g/d or % of N intake) was significantly (p = 0.038) lower in C group as compared to T and NC groups. Daily intake (g/kg $W^{0.75}$) of digestible crude protein (DCP), digestible organic matter (DOM) and total digestible nutrient (TDN) did not differ significantly (p<0.05) in the three groups. Haemoglobin (Hb) and packed cell volume (PCV) were significantly (p<0.001) higher in treatment group as compared to control. The level of Hb and PCV reduced (p<0.001) after 30 days of experimental feeding. CT significantly (p<0.001) reduced serum urea in T group as compared to NC and C groups. Serum proteins differed significantly (p<0.01) among the three groups. The activity of serum enzymes AST, ALT, ALP and LDH were also statistically non significant (p<0.05) among treatments. The weight of abomasal lymph nodes (ALN) in T group was higher (p<0.05) than in C group. Treatment group had lower (p<0.05) total worms and fecal egg count compared to control group. It may be concluded that dietary supplementation of CT through LMM significantly improved the N retention, and inhibited the different developmental stages of Haemonchus contortus in experimental sheep.

Narrowband ultraviolet B emission from gadolinium activated Y₃Ga₅O₁₂ nano-garnets

Pathak, M.S.,Singh, N.,Singh, Vijay,Watanabe, S.,Rao, T.K.Gundu,Lee, Jung-Kul Elsevier 2018 Materials research bulletin Vol.97 No.-

<P><B>Abstract</B></P> <P>Gadolinium (Gd<SUP>3+</SUP>) doped Y<SUB>3</SUB>Ga<SUB>5</SUB>O<SUB>12</SUB> nanocrystalline garnet was prepared by nitrate-fuel combustion technique that involves organic fuel glycine. Sample characterization was performed by powder X-ray diffraction and scanning electron microscope. Upon ultraviolet light excitation at 273nm, Y<SUB>3</SUB>Ga<SUB>5</SUB>O<SUB>12</SUB>:Gd<SUP>3+</SUP> sample exhibits a sharp narrowband ultraviolet B emission at 311.9nm. The electron spin resonance spectrum of gadolinium doped Y<SUB>3</SUB>Ga<SUB>5</SUB>O<SUB>12</SUB> samples exhibit resonance signals with the effective g values at <I>g</I> ≈2.0, 2.2 and 5.8. These signals are attributed to Gd<SUP>3+</SUP> ion located in distorted surroundings experiencing a relatively strong crystal field.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A narrowband ultraviolet B emitting nano-garnet was synthesized. </LI> <LI> Narrow band centered at 311.9nm, good for phototherapy application. </LI> <LI> EPR results indicate the possible location of the Gd<SUP>3+</SUP> ion. </LI> <LI> Gd<SUP>3+</SUP> ion is likely to be located at the distorted dodecahedral site. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>