65 results on '"Siva, Karthik"'
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2. Design and fabrication of interconnected 2D/3D NiS/Ni3S4 composites supercapacitor electrodes for energy storage applications
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Selvam Thulasi, Veeranan Arunprasad, and P. Siva Karthik
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Electrical and Electronic Engineering ,Condensed Matter Physics ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials - Published
- 2023
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3. Design and Fabrication of High Performance Photoanode of Fe2(MoO4)3/RGO Hybrid Composites for Triiodide Reduction in Dye-Sensitized Solar Cells
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Selvam Thulasi, Veeranan Arunprasad, P. Siva Karthik, G. Elatharasan, P. Senthil, and A. T. Rajamanickam
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General Materials Science ,General Chemistry ,Condensed Matter Physics ,Biochemistry - Published
- 2022
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4. Nanohybrids of 1D tin oxide (SnO2) nanotubes 2D-reduced graphene oxide (RGO) for improving photodegradation of Cr(VI)
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D. Ramki, M. Dharmendira Kumar, and P. Siva Karthik
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Electrical and Electronic Engineering ,Condensed Matter Physics ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials - Published
- 2023
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5. Multiomics atlas-assisted discovery of transcription factors enables specific cell state programming
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H. Kay Chung, Cong Liu, Eduardo Casillas, Brent Chick, Bryan Mcdonald, Jun Wang, Peixiang He, Ming Sun, Shixin Ma, Qiyuan Yang, Dan Chen, Filipe Hoffmann, Siva Karthik Varanasi, Victoria Tripple, Yuqing Hang, Ukrae H. Cho, Josephine Ho, April Williams, Yingxiao Wang, Diana Hargreaves, Susan M. Kaech, and Wei Wang
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Article - Abstract
The same types of cells can assume diverse states with varying functionalities. Effective cell therapy can be achieved by specifically driving a desirable cell state, which requires the elucidation of key transcription factors (TFs). Here, we integrated epigenomic and transcriptomic data at the systems level to identify TFs that define different CD8+T cell states in an unbiased manner. These TF profiles can be used for cell state programming that aims to maximize the therapeutic potential of T cells. For example, T cells can be programmed to avoid a terminal exhaustion state (TexTerm), a dysfunctional T cell state that is often found in tumors or chronic infections. However, TexTermexhibits high similarity with the beneficial tissue-resident memory T states (TRM) in terms of their locations and transcription profiles. Our bioinformatic analysis predictedZscan20, a novel TF, to be uniquely active in TexTerm. Consistently,Zscan20knock-out thwarted the differentiation of TexTermin vivo, but not that of TRM. Furthermore, perturbation ofZscan20programs T cells into an effector-like state that confers superior tumor and virus control and synergizes with immune checkpoint therapy. We also identifiedJdp2andNfil3as powerful TexTermdrivers. In short, our multiomics-based approach discovered novel TFs that enhance anti-tumor immunity, and enable highly effective cell state programming.One sentence summaryMultiomics atlas enables the systematic identification of cell-state specifying transcription factors for therapeutic cell state programming.
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- 2023
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6. CD4+ T cells regulate sickness-induced anorexia and fat wasting during a chronic parasitic infection
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Samuel E. Redford, Siva Karthik Varanasi, Karina K. Sanchez, and Janelle S. Ayres
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Catabolic responses of lean and fat energy stores are a component of the host response to infection. Cachexia is an extreme catabolic state characterized by unintentional weight loss and muscle loss, that can include fat loss. Whether cachexia plays any role in host defense or is a maladaptive consequence of host-pathogen interactions remains unknown. Traditionally studies have focused on understanding how inflammatory mediators and cells of the innate immune system contribute to the pathogenesis of cachexia and the depletion of energy stores. The cells of the adaptive immune system that regulate infection-induced cachexia remain elusive. In the present study, we examined the role of the adaptive immune response in cachexia pathogenesis using a murine model of the chronic parasitic infectionTrypanosoma brucei, the causative agent of sleeping sickness. We found that the cachectic response occurs in two phases with the first stage occurring early in the infection and involved a loss of body fat mass associated with anorexia, and the second stage occurring later in the infection and involved a sustained loss of fat mass that was accompanied by lean mass wasting. CD4+ T cells were necessary for the development of the sickness-induced anorexic response during stage 1 of the infection, which led to adipose triglyceride lipase dependent lipolysis in adipocytes and the resulting fat wasting. Adipose tissue wasting had no impact on host resistance defenses or survival of infection, both of which were antibody-mediated and independent ofCD4+ T cell responses. Our work reveals a new mechanism for infection induced cachexia involving CD4+ T cell regulation of host feeding behavior and an unexpected decoupling of adaptive immune mediated resistance from the cachectic response during infection.
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- 2022
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7. Time-Dependent Hamiltonian Reconstruction using Continuous Weak Measurements
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Siva, Karthik, Koolstra, Gerwin, Steinmetz, John, Livingston, William P., Das, Debmalya, Chen, Larry, Kreikebaum, John Mark, Stevenson, Noah, Jünger, Christian, Santiago, David I., Siddiqi, Irfan, and Jordan, Andrew N.
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Quantum Physics ,FOS: Physical sciences ,Quantum Physics (quant-ph) - Abstract
Reconstructing the Hamiltonian of a quantum system is an essential task for characterizing and certifying quantum processors and simulators. Existing techniques either rely on projective measurements of the system before and after coherent time evolution and do not explicitly reconstruct the full time-dependent Hamiltonian or interrupt evolution for tomography. Here, we experimentally demonstrate that an a priori unknown, time-dependent Hamiltonian can be reconstructed from continuous weak measurements concurrent with coherent time evolution in a system of two superconducting transmons coupled by a flux-tunable coupler. In contrast to previous work, our technique does not require interruptions, which would distort the recovered Hamiltonian. We introduce an algorithm which recovers the Hamiltonian and density matrix from an incomplete set of continuous measurements and demonstrate that it reliably extracts amplitudes of a variety of single qubit and entangling two qubit Hamiltonians. We further demonstrate how this technique reveals deviations from a theoretical control Hamiltonian which would otherwise be missed by conventional techniques. Our work opens up novel applications for continuous weak measurements, such as studying non-idealities in gates, certifying analog quantum simulators, and performing quantum metrology., Main text: 12 pages, 4 figures. Appendix: 10 pages, 4 figures
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- 2022
8. SnapShot: Cancer immunoediting
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Siva Karthik Varanasi, Susan M. Kaech, and Jack D. Bui
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Neoplasms ,Mutation ,Tumor Microenvironment ,Humans ,Tumor Escape ,General Biochemistry, Genetics and Molecular Biology - Abstract
In the tumor microenvironment, immune cells and tumor cells interact in a process called cancer immunoediting, giving rise to changes in gene expression, metabolism, mutational burden, and cellularity in the tumor. This SnapShot compares endogenous versus therapy-induced cancer immunoediting and outlines the molecular and cellular characteristics of interactions that result in complete tumor regression versus tumor escape and progression. To view this SnapShot, open or download the PDF.
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- 2022
9. Enhanced visible light photocatalytic performance of WSe2/CNT hybrid photocatalysts that were synthesized by a facile hydrothermal route
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B. Rajeshkanna, M. Durairasan, P. Siva Karthik, and J. Balaji
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Materials science ,Scanning electron microscope ,General Chemical Engineering ,General Physics and Astronomy ,02 engineering and technology ,Carbon nanotube ,010402 general chemistry ,01 natural sciences ,Hydrothermal circulation ,law.invention ,chemistry.chemical_compound ,symbols.namesake ,law ,Selenide ,Methyl orange ,General Materials Science ,General Engineering ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Chemical engineering ,chemistry ,Transmission electron microscopy ,Photocatalysis ,symbols ,0210 nano-technology ,Raman spectroscopy - Abstract
In this investigation, a facile and cost-effective method was developed for fabricating the tungsten selenide/carbon nanotube (WSe2/CNT) hybrid photocatalysts by an aqueous hydrothermal method. The structural, optical, and photocatalytic activities of the prepared photocatalysts were investigated through various characterization techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectra analysis, UV-Vis spectra analysis, and photoluminescence spectra analysis. The photocatalytic activity of the catalysts was tested toward methyl orange (MO) under visible light irradiation. The WSe2/CNT hybrid photocatalysts show outstanding efficiency (95%), high rate constant (0.341 min−1), and high stability. Moreover, the WSe2/CNT composite exhibits enhanced photoconversion efficiency (8.23%) under solar light. The possible photovoltaic mechanism was also proposed and discussed.
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- 2021
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10. A microglia-CD4+ T cell partnership generates protective anti-tumor immunity to glioblastoma
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Dan Chen, Siva Karthik Varanasi, Toshiro Hara, Kacie Traina, Bryan McDonald, Yagmur Farsakoglu, Josh Clanton, Shihao Xu, Thomas H. Mann, Victor Du, H. Kay Chung, Ziyan Xu, Victoria Tripple, Eduardo Casillas, Shixin Ma, Carolyn O’Connor, Qiyuan Yang, Ye Zheng, Tony Hunter, Greg Lemke, and Susan M. Kaech
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SummaryThe limited efficacy of immunotherapies against glioblastoma illustrates the urgent need to better understand the interactions between the central nervous system and the immune system. Here, we showed that a protective response to αCTLA-4 therapy depended on a mutualistic relationship between microglia and CD4+ T cells. Suppression of gliomas by CD4+ T cells did not require tumor-intrinsic MHC-II expression, but rather was dependent on the selective expression of MHC-II and antigen presentation by local microglia that in turn, sustained CD4+ T cell tumoricidal effector functions. CD4+ T cell secretion of IFNγ made the glioma cells vulnerable to enhanced tumor surveillance and phagocytosis by microglia via the AXL/MER tyrosine kinase receptors that were necessary for tumor suppression. This work illustrates a novel partnership between CD4+ T cells and microglia that unleashes the tumoricidal properties of microglia that can be harnessed to improve immunotherapies for glioblastoma.
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- 2022
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11. Enhanced performance of dye-sensitized solar cell-based g-C3N4/Ag3PO4 hybrid composites as novel electrodes fabricated by facial hydrothermal approach
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M. Durairasan, P. Siva Karthik, and K. K. Saravanan
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010302 applied physics ,Materials science ,Photoluminescence ,Scanning electron microscope ,Analytical chemistry ,Condensed Matter Physics ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,symbols.namesake ,Dye-sensitized solar cell ,Transmission electron microscopy ,0103 physical sciences ,Electrode ,symbols ,Electrical and Electronic Engineering ,Raman spectroscopy ,Nanosheet ,Visible spectrum - Abstract
In this work, holey g-C3N4 nanosheet wrapped Ag3PO4 composite was prepared by facile hydrothermal method. The structural, morphological, optical and elemental composition of the samples were analyzed by X-ray diffraction, Scanning electron microscope, Transmission electron microscope, Raman, UV–Vis diffuse reflectance spectra, Photoluminescence, N2 adsorption–desorption and X-ray photoelectron spectra, respectively. Systematic investigation indicated that phosphorus was effectively doped into the g-C3N4 framework, which increases the BET surface area, expands the visible light response region, and elevates the separation efficiency of electron–hole pairs. Sandwich type DSSC was fabricated and studied the studied the J–V characteristics. The results suggest that the optimal composite electrode (APG-50) with Ag3PO4/g-C3N4 ratio of 3:1 showed high photo-conversion efficiency (9.71%) than compared with bare g-C3N4 (1.89%) and Ag3PO4 (2.52%) electrodes, respectively. Besides, the EIS comes about illustrate that the APG-50 test appears tall electron exchange proficiency and lifetime. The progressed instrument of the proposed materials was moreover examined in detail.
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- 2021
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12. Determinants of Tissue-Specific Metabolic Adaptation of T Cells
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Siva Karthik Varanasi, Barry T. Rouse, and Sushmitha Vijaya Kumar
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0301 basic medicine ,Physiology ,T-Lymphocytes ,Niche ,Inflammation ,Disease ,Biology ,Lymphocyte Activation ,medicine.disease_cause ,Article ,Autoimmunity ,03 medical and health sciences ,0302 clinical medicine ,Immune system ,medicine ,Animals ,Humans ,Molecular Biology ,Mechanism (biology) ,Cell Biology ,030104 developmental biology ,Cellular Microenvironment ,medicine.symptom ,Adaptation ,Energy Metabolism ,Neuroscience ,030217 neurology & neurosurgery ,Function (biology) - Abstract
Summary Metabolic reprogramming is a hallmark of T cell activation and function. As our understanding of T cell metabolism increases, so does our appreciation of its inherent complexity. The metabolic heterogeneity of T cells that reside in different locations, such as lymphoid and non-lymphoid tissues, presents a challenge to developing therapies that exploit metabolic vulnerabilities. The roots of metabolic heterogeneity are only beginning to be understood. Here, we propose four factors that contribute to the adaptation of T cells to their dynamic tissue environment: (1) functional status of T cells, (2) local factors unique to the tissue niche, (3) type of inflammation, and (4) time spent in a specific tissue. We review emerging concepts about tissue-specific metabolic reprogramming in T cells with particular attention to explain how such metabolic properties are used as an adaptation mechanism. Adaptation of immune cells to the local microenvironment is critical for their persistence and function. Here, Varanasi et al. review the role and types of metabolic adaptation acquired by T cells in tissues and how these adaptations might differ between tissue type, disease state, and functionality of a T cell.
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- 2020
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13. Studies on growth, optical, dielectric, and third-order nonlinearity of 4-methyl N-(4-chlorobenzylidene)aniline (4CBT) crystal
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J. Balaji, G. Vinitha, P. Siva Karthik, P. Ramnivasmirtha, X. Cecily Maria Sneha, and D. Gajalaskhmi
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010302 applied physics ,Materials science ,Infrared ,Analytical chemistry ,Physics::Optics ,Dielectric ,Condensed Matter Physics ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,Crystal ,0103 physical sciences ,Thermal stability ,Electrical and Electronic Engineering ,Refractive index ,HOMO/LUMO ,Single crystal ,Monoclinic crystal system - Abstract
4-methyl N-(4-chlorobenzylidene)aniline (4CBT) single crystal with dimension of 10 × 7 × 2 mm3 has been grown by the slow evaporation solution growth method. 4CBT crystal belonging to the monoclinic crystal system with space group of P21/c was studied by single-crystal X-ray diffraction. Fourier transform infrared analysis shows the existence of functional groups in 4CBT crystal. The existence of different protons position is confirmed using 1HNMR analysis. The optical nature of 4CBT is illustrated with help of cut-off wavelength and the transparency of the titled compound. The thermal stability of the grown crystal was analysed by thermogravimetric technique. Dielectric studies were also studied with respect to temperature and frequency. The energy values of highest occupied molecular orbital and lowest unoccupied molecular orbital have been measured by frontier molecular analysis. Third-order nonlinear optical properties of 4-methyl N-(4-chlorobenzylidene) aniline crystal were measured by Z-scan technique and the measured values of the nonlinear index of refraction and absorption coefficient shows the suitability of grown crystal for photonic applications.
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- 2020
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14. A one-pot hydrothermal-induced PANI/SnO2 and PANI/SnO2/rGO ternary composites for high-performance chemiresistive-based H2S and NH3 gas sensors
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B. Rajeshkanna, P. Siva Karthik, K. K. Saravanan, J. Balaji, and P. Ramnivas Mirtha
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010302 applied physics ,Nanocomposite ,Materials science ,Condensed Matter Physics ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,Hydrothermal circulation ,Electronic, Optical and Magnetic Materials ,chemistry.chemical_compound ,Polymerization ,chemistry ,Rutile ,Specific surface area ,0103 physical sciences ,Electrical and Electronic Engineering ,Composite material ,Fourier transform infrared spectroscopy ,Ternary operation ,Carbon monoxide - Abstract
We have fabricated the PANI/SnO2 and PANI/SnO2/rGO ternary composites by facile one-step hydrothermal approach followed by polymerization method. The hybrid nanocomposites were scientifically investigated for their structural, morphological and elemental composition through XRD, TEM, EDAX, FTIR and EPR analysis. The tetragonal rutile phase with nanospherical morphology sizes in the range of 25–35 nm was investigated by XRD and TEM results. The N2 adsorption–desorption measurement showed that ternary PANI/SnO2/rGO composite showed huge specific surface area (114.51 m2/g) and pore size (17–21 nm), which is higher than the bare SnO2 (surface area = 83.51 m2/g; pore size = 33–37 nm). The chemiresistive-type gas sensor was fabricated and the designed sensors were investigated by their sensing responses towards different gases (ethanol, methanol, carbon monoxide, oxygen, H2S and NH3). The results exposed that the ternary PANI/SnO2/rGO showed high sensing response (56%), fast response (35 s) and recovery time (40 s) towards H2S gas than other gases. The improved gas-sensing mechanism was also proposed.
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- 2020
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15. Crystal growth, characterization and third order nonlinear optical studies of N’-[(E)-(4-chlorophenyl)(phenyl)methylene]-4-methylbenzenesulfonohydrazide for optical applications
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X. Cecily Maria Sneha, D. Gajalakshmi, P. M. Ram Sri Nivas, C. Indumathi, T. C. Sabari Girisun, P. Siva Karthik, and J. Balaji
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General Materials Science ,General Chemistry - Published
- 2022
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16. Profit improvement through process optimization Declaration of Originality
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Siva, Karthik Shanmuganandam
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- 2022
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17. Self-Supervised Object Detection via Generative Image Synthesis
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Mustikovela, Siva Karthik, De Mello, Shalini, Prakash, Aayush, Iqbal, Umar, Liu, Sifei, Nguyen-Phuoc, Thu, Rother, Carsten, and Kautz, Jan
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FOS: Computer and information sciences ,Computer Vision and Pattern Recognition (cs.CV) ,Computer Science - Computer Vision and Pattern Recognition - Abstract
We present SSOD, the first end-to-end analysis-by synthesis framework with controllable GANs for the task of self-supervised object detection. We use collections of real world images without bounding box annotations to learn to synthesize and detect objects. We leverage controllable GANs to synthesize images with pre-defined object properties and use them to train object detectors. We propose a tight end-to-end coupling of the synthesis and detection networks to optimally train our system. Finally, we also propose a method to optimally adapt SSOD to an intended target data without requiring labels for it. For the task of car detection, on the challenging KITTI and Cityscapes datasets, we show that SSOD outperforms the prior state-of-the-art purely image-based self-supervised object detection method Wetectron. Even without requiring any 3D CAD assets, it also surpasses the state-of-the-art rendering based method Meta-Sim2. Our work advances the field of self-supervised object detection by introducing a successful new paradigm of using controllable GAN-based image synthesis for it and by significantly improving the baseline accuracy of the task. We open-source our code at https://github.com/NVlabs/SSOD.
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- 2021
18. Macrophage-Mediated Phagocytosis and Dissolution of Amyloid-Like Fibrils in Mice, Monitored by Optical Imaging
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James S. Foster, Anna B. Williams, Dianne J. Trent, Tina Richey, Emily B. Martin, Siva Karthik Varanasi, Alexa Stroh, Stephen A. Kania, Jonathan S. Wall, Craig Wooliver, Sallie Macy, Elizabeth N. Ergen, Stephen J. Kennel, Angela Williams, and R. Eric Heidel
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Amyloid ,Phagocytosis ,030204 cardiovascular system & hematology ,Fibril ,Article ,Pathology and Forensic Medicine ,Mice ,03 medical and health sciences ,0302 clinical medicine ,medicine ,Extracellular ,Animals ,Macrophage ,Innate immune system ,Chemistry ,Macrophages ,Amyloidosis ,Optical Imaging ,medicine.disease ,030220 oncology & carcinogenesis ,Biophysics ,Female ,Infiltration (medical) - Abstract
Light chain–associated amyloidosis is characterized by the extracellular deposition of amyloid fibrils in abdominothoracic organs, skin, soft tissue, and peripheral nerves. Phagocytic cells of the innate immune system appear to be ineffective at clearing the material; however, human light chain amyloid extract, injected subcutaneously into mice, is rapidly cleared in a process that requires neutrophil activity. To better elucidate the phagocytosis of light chain fibrils, a potential method of cell-mediated dissolution, amyloid-like fibrils were labeled with the pH-sensitive dye pHrodo red and a near infrared fluorophore. After injecting this material subcutaneously in mice, optical imaging was used to quantitatively monitor phagocytosis and dissolution of fibrils concurrently. Histologic evaluation of the residual fibril masses revealed the presence of CD68(+), F4/80(+), ionized calcium binding adaptor molecule 1(−) macrophages containing Congo red–stained fibrils as well as neutrophil-associated proteins with no evidence of intact neutrophils. These data suggest an early infiltration of neutrophils, followed by extensive phagocytosis of the light chain fibrils by macrophages, leading to dissolution of the mass. Optical imaging of this novel murine model, coupled with histologic evaluation, can be used to study the cellular mechanisms underlying dissolution of synthetic amyloid-like fibrils and human amyloid extracts. In addition, it may serve as a test bed to evaluate investigational opsonizing agents that might serve as therapeutic agents for light chain–associated amyloidosis.
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- 2019
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19. Uptake of oxidized lipids from the tumor microenvironment by the scavenger receptor CD36 promotes lipid peroxidation and dysfunction in CD8 T cells
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Xu, Shihao, Chaudhary, Omkar, Rodríguez-Morales, Patricia, Sun, Xiaoli, Chen, Dan, Zappasodi, Roberta, Xu, Ziyan, Pinto, Antonio F. M., Williams, April, Schulze, Isabell, Farsakoglu, Yagmur, Varanasi, Siva Karthik, Low, Jun Siong, Tang, Wenxi, Wang, Haiping, McDonald, Bryan, Tripple, Victoria, Downes, Michael, Evans, Ronald M., Abumrad, Nada A., Merghoub, Taha, Wolchok, Jedd D., Shokhirev, Maxim N., Ho, Ping-Chih, Witztum, Joseph L., Emu, Brinda, Cui, Guoliang, and Kaech, Susan M.
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CD36 Antigens ,Neoplasms ,Tumor Microenvironment ,Ferroptosis ,Humans ,CD8-Positive T-Lymphocytes ,Article - Abstract
A common metabolic alteration in the tumor microenvironment (TME) is lipid accumulation, a feature associated with immune dysfunction. Here we examined how CD8(+) tumor infiltrating lymphocytes (TILs) respond to lipids within the TME. We found elevated concentrations of several classes of lipids in the TME and accumulation of these in CD8(+) TILs. Lipid accumulation was associated with increased expression of CD36, a scavenger receptor for oxidized lipids, on CD8(+) TILs, which also correlated with progressive T cell dysfunction. Cd36(−/−) T cells retained effector functions in the TME, as compared to WT counterparts. Mechanistically, CD36 promoted uptake of oxidized low-density lipoproteins (OxLDL) into T cells and this induced lipid peroxidation and downstream activation of p38 kinase. Inhibition of p38 restored effector T cell functions in vitro, and resolution of lipid peroxidation by over-expression of glutathione peroxidase 4 restored functionalities in CD8(+) TILs in vivo. Thus, an oxidized lipid-CD36 axis promotes intratumoral CD8 T cell dysfunction and serves as a therapeutic avenue for immunotherapies.
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- 2021
20. Correction: CuNi2S4-reduced graphene oxide composites as an efficient counter electrode for high performance dye-sensitized solar cells
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D. Ramki, M. Dharmendira Kumar, and P. Siva Karthik
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Electrical and Electronic Engineering ,Condensed Matter Physics ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials - Published
- 2022
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21. Hydrothermal production of low-cost CeNi2S4-reduced graphene oxide composites as an efficient counter electrode for high performance dye-sensitized solar cells
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K. Paramasivaganesh, D. Sakthilatha, A. Sankar, P. Siva Karthik, Mohd. Shkir, F. Maiz, Woo Kyoung Kim, and Sreedevi Gedi
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Inorganic Chemistry ,Materials Chemistry ,Physical and Theoretical Chemistry - Published
- 2022
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22. Abstract 2531: a
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Adarsh Rajesh, Aaron Havas, Siva Karthik Varanasi, Katrina Evans, Bassem B. Cheikh, Clemens Duerrschmid, Najiba Mammadova, Peter Adams, and Susan Kaech
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Cancer Research ,Oncology - Abstract
Hepatocellular carcinoma (HCC) is an emerging health crisis due to rapidly increasing incidence rates and an overall 5-year survival rate of 18%. Consequently, there is an urgent need for new therapies and better preventive strategies. Aging and obesity are two of the biggest risk factors for HCC, and with ever-increasing aging and obese populations, uncovering how aging and obesity drive the increased risk for HCC has become imperative. Aging and obesity are well known to be characterized by immune dysregulation leading to persistent inflammation, and a dysregulated immune microenvironment is also a common theme shared by multiple hallmarks of HCC. In this study, we aim to assess the immune microenvironment of aged and obese mouse livers by performing spatial phenotyping of distinct immune signatures which can potentially predispose hepatocytes to HCC. To address this, we used Akoya’s ultra-high multiplexed CODEX (CO-Detection by indEXing) imaging system to interrogate 31 different biomarkers in liver samples at the single cell level. Specifically, we compared the liver immune microenvironment of mice within 2 different treatment groups (old mice on a high fat diet (HFD) and young mice on a normal diet (ND)) to the immune landscape of liver tumor tissue. Our goal is to identify distinct immune phenotypes present in both, liver tumor tissues and livers of HFD mice, compared to ND livers - to better understand how immune dysregulation can predispose an aged and obese liver to HCC. Citation Format: Adarsh Rajesh, Aaron Havas, Siva Karthik Varanasi, Katrina Evans, Bassem B. Cheikh, Clemens Duerrschmid, Najiba Mammadova, Peter Adams, Susan Kaech. a [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2531.
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- 2022
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23. Design and Fabrication of High Performance Photoanode of Fe2(MoO4)3/RGO Hybrid Composites For Triiodide Reduction in Dye-Sensitized Solar Cells
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Selvam Thulasi, Veeranan Arunprasad, P. Senthil, G. Elatharasan, and Siva Karthik
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Reduction (complexity) ,chemistry.chemical_compound ,Dye-sensitized solar cell ,Materials science ,Fabrication ,chemistry ,Chemical engineering ,Triiodide - Abstract
Discovery of electrode materials with superior light harvesting performance with high conductivity nature have become more and more urgent for the field of photovoltaics and portable electronic devices. Here in, synthesis of Fe2(MoO4)3/reduced graphene oxide (RGO) nanocomposite was prepared by simple hydrothermal approach and used as high efficient dye sensitized solar cells (DSSCs). The decoration of RGO into the Fe2(MoO4)3 was proved by various physic-chemical studies such as XRD, SEM, TEM, Raman, UV, PL and BET analysis. Due to the synergic effect between the Fe2(MoO4)3 and RGO the light absorption property is significantly improved as well the high surface area (112.5 m2/g) and pore size (38.7 nm) was achieved than compared with bare Fe2(MoO4)3 (88.5 m2/g and 17.8 nm). The Fe2(MoO4)3/RGO hybrid photoanode establish to display an outstanding catalytic activity toward the reduction of triiodide to iodide in a dye-sensitized solar cell (DSSC) and can provide a solar cell efficiency of 9.65%, which is superior to a Pt-based DSSC (6.17%). The better electro-catalytic ability of Fe2(MoO4)3/RGO electrode is obtained by a synergistic effect that resulted in the high specific surface area and intrinsic reactivity of the photocathode materials.
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- 2021
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24. Intrinsic Autoencoders for Joint Deferred Neural Rendering and Intrinsic Image Decomposition
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Varun Jampani, Hassan Abu Alhaija, Justus Thies, Siva Karthik Mustikovela, Matthias Nießner, Carsten Rother, and Andreas Geiger
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Image formation ,Deferred shading ,Artificial neural network ,business.industry ,Computer science ,Supervised learning ,ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION ,02 engineering and technology ,010501 environmental sciences ,Real image ,01 natural sciences ,Autoencoder ,Graphics pipeline ,Rendering (computer graphics) ,0202 electrical engineering, electronic engineering, information engineering ,020201 artificial intelligence & image processing ,Computer vision ,Artificial intelligence ,business ,0105 earth and related environmental sciences - Abstract
Neural rendering techniques promise efficient photorealistic image synthesis while providing rich control over scene parameters by learning the physical image formation process. While several supervised methods have been proposed for this task, acquiring a dataset of images with accurately aligned 3D models is very difficult. The main contribution of this work is to lift this restriction by training a neural rendering algorithm from unpaired data. We propose an autoencoder for joint generation of realistic images from synthetic 3D models while simultaneously decomposing real images into their intrinsic shape and appearance properties. In contrast to a traditional graphics pipeline, our approach does not require to specify all scene properties, such as material parameters and lighting by hand. Instead, we learn photo-realistic deferred rendering from a small set of 3D models and a larger set of unaligned real images, both of which are easy to acquire in practice. Simultaneously, we obtain accurate intrinsic decompositions of real images while not requiring paired ground truth. Our experiments confirm that a joint treatment of rendering and decomposition is indeed beneficial and that our approach outperforms state-of-the-art image-to-image translation baselines both qualitatively and quantitatively.
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- 2020
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25. Oxidized Lipids and CD36-Mediated Lipid Peroxidation in CD8 T Cells Suppress Anti-Tumor Immune Responses
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Michael Downes, Joseph L. Witztum, Nada A. Abumrad, Bryan McDonald, Antonio Pinto, Susan M. Kaech, Ping-Chih Ho, Maxim N. Shokhirev, Xiaoli Sun, Shihao Xu, Dan Chen, Taha Merghoub, Jun Siong Low, Patricia Rodríguez-Morales, Ronald M. Evans, Victoria Tripple, Brinda Emu, Haiping Wang, Yagmur Farsakoglu, Jedd D. Wolchok, Siva Karthik Varanasi, April Williams, Ziyan Xu, Omkar Chaudhary, Roberta Zappasodi, Wenxi Tang, and Guoliang Cui
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biology ,Chemistry ,CD36 ,T cell ,hemic and immune systems ,GPX4 ,Cell biology ,Lipid peroxidation ,chemistry.chemical_compound ,Immune system ,medicine.anatomical_structure ,biology.protein ,medicine ,Cytotoxic T cell ,lipids (amino acids, peptides, and proteins) ,Scavenger receptor ,CD8 - Abstract
SummaryT cell metabolic fitness plays a pivotal role in anti-tumor immunity and metabolic deregulation causes T cell dysfunction (i.e., ‘exhaustion’) in cancer. We identify that the scavenger receptor CD36 limits anti-tumor CD8+T cell effector functions through lipid peroxidation. In murine tumors, oxidized phospholipids (OxPLs) were highly abundant and CD8+TILs increased uptake and accumulation of lipids and lipid peroxidation. Functionally ‘exhausted’ CD8+TILs substantially increased CD36 expression and CD36-deficient CD8+TILs had more robust anti-tumor activity and cytokine production than wild-type cells. We further show that CD36 promotes uptake of oxidized low-density lipoproteins (OxLDL) and induces lipid peroxidation in CD8+TILs, and OxLDL inhibits CD8+T cell functions in a CD36-dependent manner. Moreover, glutathione peroxidase 4 (GPX4) over-expression lowers lipid peroxidation and restores functionalities in CD8+TILs. These results define a key role for an oxidized lipid-CD36 axis in promoting intratumoral CD8+T cell dysfunction.
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- 2020
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26. Assessment of estrogen receptor, progesterone receptor of infiltrating ductal carcinoma of breast for neoadjuvant chemotherapy
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P Siva Karthik, Balasundaram, and Ranjit Kumar
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Oncology ,Chemotherapy ,medicine.medical_specialty ,Randomization ,Cyclophosphamide ,business.industry ,medicine.medical_treatment ,Estrogen receptor ,medicine.disease ,Chemotherapy regimen ,Breast cancer ,Docetaxel ,Internal medicine ,Progesterone receptor ,Medicine ,business ,medicine.drug - Abstract
Background:The aims and objectives of this study are to study the influence of Estrogen receptor ER, Progesterone receptor PR of patients having infiltrating ductal carcinoma of breast recieving Neoadjuvant chemotherapy, To study the influence of ER and PR receptors in patients receiving neoadjuvant chemotherapy & correlate complete pathological response. Methods . Type of study: Prospective clinical study. present study was carried out in the department of general surgery Vinayaka Missions medical college and hospital karaikal from July 2016 – December 2017.. HPE (Histopathological examination) and ER PR status was done. Patients diagnosed with locally advanced breast cancer underwent simple randomization into 2 treatment groupsGroup 1: AC (Adriamycin 60mg/m2, Cyclophosphamide 600mg/m2) once every 3 weeks for 4 cyclesGroup2: Docetaxel 75 mg/m2 for 4 cycles every 3 weekly (11).Clinical examination was performed after every two cycles and completing all the chemotherapy, study group patients were subjected to Modified radical mastectomy which was then followed by evaluation of pathological response. Conclusion: In this study 30 patients ER PR status was done. According to ER PR status Neoadjuvant chemotherapy regimen given. NCT response was assessed with clinical / imaging study. There was reduction in tumor size and change in lymph node status in both the groups with p value of .44. As our study size is small we cannot predict the actual outcome of the two study groups. We need larger sample size to predict the actual outcome.Results: The statistical analysis was performed by STATA 11.2. Descriptive statistics of frequency and percentage were performed all the study variables. Chi square test were used to measure the association between the CP response with ER status. P
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- 2019
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27. Dissecting anti-tumor immunity in glioblastoma
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Dan Chen and Siva Karthik Varanasi
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Immunology ,Immunology and Allergy - Abstract
Glioblastoma multiforme (GBM) is the deadliest form of brain cancer, for which there is currently no effective treatment. Despite success of immunotherapies such as checkpoint inhibitors (CPI) in treating some cancers, less than 8% of GBM patients responded to anti-PD-1 therapy. Thus, we need to understand what mechanisms underlie tumor resistance to immunotherapies. In our GBM mouse model, we have found that anti-CTLA-4 treatment greatly improved survival and suppressed tumor growth, but surprisingly, its efficacy was lost in mice that were depleted of CD4+ but not CD8+ T cells, suggesting that CD4+ T cells are critical for protection against GBM. This matches clinical data showing decreased populations of CD4+ T cells in patients with adverse clinical outcomes such as high-grade GBM. Our preliminary results from flow cytometry and single-cell RNA sequencing (sc-RNAseq) also suggested enhanced cytokine production (IFNγ, TNFα, IL-2) in CD4+ T cells after anti-CTLA-4 treatment. Similarly, we found that microglia, the local sentinels of the central nervous system, also play a significant role in tumor control, as indicated by faster GBM growth and reduced number of tumor-infiltrating CD4+ T cells when mice are depleted of microglia by a CSF1R inhibitor (PLX3397). Additionally, microglia in GBM may serve as potential antigen-presenting cells, as shown by their high MHC class II (MHC-II) expression. Therefore, we postulate that microglia are necessary to sustain anti-tumor immunity by CD4+ T cells. Importantly, through a more detailed exploration of how CD4+ T cells and microglia interact to impact tumor control, our study will provide new insights for developing therapeutic strategies against “difficult-to-treat” cancers such as GBM.
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- 2022
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28. Role of IL-18 induced Amphiregulin expression on virus induced ocular lesions
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Ujjaldeep Jaggi, Siva Karthik Varanasi, Naveen K. Rajasagi, and Barry T. Rouse
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0301 basic medicine ,medicine.medical_treatment ,Immunology ,Amphiregulin ,T-Lymphocytes, Regulatory ,p38 Mitogen-Activated Protein Kinases ,Article ,Pathogenesis ,Lesion ,Cornea ,03 medical and health sciences ,Mice ,T-Lymphocyte Subsets ,Immunology and Allergy ,Medicine ,Animals ,Simplexvirus ,Gene knockout ,Mice, Knockout ,Receptors, Interleukin-18 ,business.industry ,Effector ,Interleukin-18 ,Herpes Simplex ,Interleukin-12 ,3. Good health ,Mice, Inbred C57BL ,030104 developmental biology ,Cytokine ,Cancer research ,Keratitis, Herpetic ,Interleukin 18 ,Female ,Signal transduction ,medicine.symptom ,business ,Signal Transduction - Abstract
This report deals with the possible mechanism by which IL-18 can contribute to the control and resolution of inflammatory lesions in the cornea caused by herpes simplex virus infection. Our results demonstrate that the expression of the IL-18R by both regulatory T cells (Treg) and effector T cells was a pivotal event that influenced lesion pathogenesis. The engagement of IL-18R on Treg with its cytokine ligand resulted in Amphiregulin expression a molecule associated with tissue repair. In support of this scheme of events, lesion severity became more severe in animals unable to express the IL-18R because of gene knockout and was reduced in severity when IL-18 was overexpressed in the cornea. These changes in lesion severity correlated with the frequency and number of both Treg and Teff that expressed Amphiregulin. Additional experiments indicated that IL-12 and IL-18 acted synergistically to enhance Amphiregulin expression in Treg, an event partly dependent on P38 MAPK activity. Finally, sub-conjunctival administration of Amphiregulin resulted in resolution of both developing and developed lesions. Thus, overall our results imply that IL-18 may participate in controlling the severity of SK and contribute to tissue repair by converting both Treg and effector T cells into those that produce Amphiregulin.
- Published
- 2018
29. How host metabolism impacts on virus pathogenesis
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Siva Karthik Varanasi and Barry T. Rouse
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0301 basic medicine ,Virus pathogenesis ,viruses ,Viral pathogenesis ,CD8-Positive T-Lymphocytes ,Biology ,Virus ,Mice ,03 medical and health sciences ,Immune system ,Virology ,Metabolome ,Animals ,Humans ,Host resistance ,Nutrients ,Metabolism ,Metabolic pathway ,Glucose ,030104 developmental biology ,Virus Diseases ,Host-Pathogen Interactions ,Viruses ,Immunology ,Immunologic Memory ,Metabolic Networks and Pathways - Abstract
The outcome of virus infections depends on multiple factors. This review deals with the role of host metabolism as one such factor. We describe how different cells in the immune system employ differential metabolic pathways and how this relates to the outcome of virus infections. We also discuss how nutritional and metabolic diseases can influence the nature of viral pathogenesis as well as how targeted therapies against metabolic processes can impact on the outcome of virus infections. The case is also made for metabolic profiling as a potential tool to predict the outcome of a virus infection and to guide therapies that enhance host resistance.
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- 2018
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30. Material Selection and Structural Integration of Actively Cooled High Speed Combustion Chamber
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C.V.S.S. Siva Karthik and T. Kishen Kumar Reddy
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Material selection ,Computer science ,Heat transfer ,Active cooling ,Mechanical engineering ,Supersonic speed ,Heat sink ,Combustion chamber ,Finite element method ,Coolant - Abstract
Thermal management in the supersonic combustion chambers subjected to high heat fluxes is vital for maintaining their integrity. At high temperatures ordinary materials cannot sustain the high heat loads. On the other hand, the prevailing high temperature gradients, necessitates the provision for expansion to avoid build of thermal stresses for the integration. Hence, thermal management needs a holistic approach encompassing the areas of material selection, heat transfer and structural integration. The current state of art research is focused on achieving this by active cooling through endothermic fuel, which is used as a coolant due to the advantages such as reduced weight and improved heat sink capacities. Particularly the space applications pose serious limitations on the weight. 1D thermo-structural hand calculations can be easy point to start with to arrive at the optimized shape of the single actively cooled channel. But the underlying assumptions and owing to the 1D nature of the such calculations, pose limitation towards understanding the behavior of the active panel as a whole and achieving the practical integration strategy. Therefore, there is need to perform 3D CFD and FEA thermo-structural analysis of the active panel structure. This paper extends upon the approach of 1D analytical material selection methodology through weight optimization followed by rigorous CFD and FEA analysis to understand and device ways for structural integration for long duration flight of about 600 seconds.
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- 2018
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31. Manipulating Glucose Metabolism during Different Stages of Viral Pathogenesis Can Have either Detrimental or Beneficial Effects
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Dallas Donohoe, Barry T. Rouse, Siva Karthik Varanasi, and Ujjaldeep Jaggi
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0301 basic medicine ,Drug-Related Side Effects and Adverse Reactions ,Viral pathogenesis ,Immunology ,Anti-Inflammatory Agents ,Herpesvirus 1, Human ,Deoxyglucose ,Carbohydrate metabolism ,Biology ,Virus Replication ,T-Lymphocytes, Regulatory ,Article ,Virus ,Proinflammatory cytokine ,Cornea ,Mice ,03 medical and health sciences ,0302 clinical medicine ,T-Lymphocyte Subsets ,In vivo ,medicine ,Animals ,Immunology and Allergy ,Cells, Cultured ,Herpes Simplex ,medicine.disease ,In vitro ,Mice, Inbred C57BL ,Glucose ,030104 developmental biology ,Viral replication ,Keratitis, Herpetic ,Encephalitis ,Female ,Inflammation Mediators ,030215 immunology - Abstract
This report deals with physiological changes and their implication following ocular infection with HSV. This infection usually results in a blinding inflammatory reaction in the cornea, orchestrated mainly by proinflammatory CD4 T cells and constrained in severity by regulatory T cells. In the present report, we make the unexpected finding that blood glucose levels change significantly during the course of infection. Whereas levels remained normal during the early phase of infection when the virus was actively replicating in the cornea, they increased around 2-fold during the time when inflammatory responses to the virus was occurring. We could show that glucose levels influenced the extent of induction of the inflammatory T cell subset in vitro that mainly drives lesions, but not regulatory T cells. Additionally, if glucose utilization was limited in vivo as a consequence of therapy in the inflammatory phase with the drug 2-deoxy-glucose (2DG), lesions were diminished compared with untreated infected controls. In addition, lesions in 2DG-treated animals contained less proinflammatory effectors. Glucose metabolism also influenced the acute phase of infection when the replicating virus was present in the eye. Thus, therapy with 2DG to limit glucose utilization caused mice to become susceptible to the lethal effects of HSV infection, with the virus spreading to the brain causing encephalitis. Taken together, our results indicate that glucose metabolism changed during the course of HSV infection and that modulating glucose levels can influence the outcome of infection, being detrimental or beneficial according to the stage of viral pathogenesis.
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- 2017
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32. Study of Scrub Typhus in Rural Bangalore
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P Siva Karthik, Reddy, Vasantha, Kamath, and Hima, Bindu
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Orientia tsutsugamushi ,Rural Population ,Scrub Typhus ,Humans ,India - Published
- 2020
33. Intrinsic Autoencoders for Joint Neural Rendering and Intrinsic Image Decomposition
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Alhaija, Hassan Abu, Mustikovela, Siva Karthik, Thies, Justus, Jampani, Varun, Nießner, Matthias, Geiger, Andreas, and Rother, Carsten
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FOS: Computer and information sciences ,Computer Science - Graphics ,Computer Vision and Pattern Recognition (cs.CV) ,Computer Science - Computer Vision and Pattern Recognition ,ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION ,Graphics (cs.GR) - Abstract
Neural rendering techniques promise efficient photo-realistic image synthesis while at the same time providing rich control over scene parameters by learning the physical image formation process. While several supervised methods have been proposed for this task, acquiring a dataset of images with accurately aligned 3D models is very difficult. The main contribution of this work is to lift this restriction by training a neural rendering algorithm from unpaired data. More specifically, we propose an autoencoder for joint generation of realistic images from synthetic 3D models while simultaneously decomposing real images into their intrinsic shape and appearance properties. In contrast to a traditional graphics pipeline, our approach does not require to specify all scene properties, such as material parameters and lighting by hand. Instead, we learn photo-realistic deferred rendering from a small set of 3D models and a larger set of unaligned real images, both of which are easy to acquire in practice. Simultaneously, we obtain accurate intrinsic decompositions of real images while not requiring paired ground truth. Our experiments confirm that a joint treatment of rendering and decomposition is indeed beneficial and that our approach outperforms state-of-the-art image-to-image translation baselines both qualitatively and quantitatively.
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- 2020
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34. Self-Supervised Viewpoint Learning From Image Collections
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Carsten Rother, Jan Kautz, Umar Iqbal, Sifei Liu, Varun Jampani, Shalini De Mello, and Siva Karthik Mustikovela
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FOS: Computer and information sciences ,Computer science ,business.industry ,Computer Vision and Pattern Recognition (cs.CV) ,SIGNAL (programming language) ,Computer Science - Computer Vision and Pattern Recognition ,02 engineering and technology ,Iterative reconstruction ,010501 environmental sciences ,Object (computer science) ,01 natural sciences ,Image (mathematics) ,0202 electrical engineering, electronic engineering, information engineering ,Code (cryptography) ,020201 artificial intelligence & image processing ,The Internet ,Artificial intelligence ,business ,0105 earth and related environmental sciences - Abstract
Training deep neural networks to estimate the viewpoint of objects requires large labeled training datasets. However, manually labeling viewpoints is notoriously hard, error-prone, and time-consuming. On the other hand, it is relatively easy to mine many unlabelled images of an object category from the internet, e.g., of cars or faces. We seek to answer the research question of whether such unlabeled collections of in-the-wild images can be successfully utilized to train viewpoint estimation networks for general object categories purely via self-supervision. Self-supervision here refers to the fact that the only true supervisory signal that the network has is the input image itself. We propose a novel learning framework which incorporates an analysis-by-synthesis paradigm to reconstruct images in a viewpoint aware manner with a generative network, along with symmetry and adversarial constraints to successfully supervise our viewpoint estimation network. We show that our approach performs competitively to fully-supervised approaches for several object categories like human faces, cars, buses, and trains. Our work opens up further research in self-supervised viewpoint learning and serves as a robust baseline for it. We open-source our code at https://github.com/NVlabs/SSV., Comment: Accepted at CVPR 20
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- 2020
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35. T Cell Metabolism in a State of Flux
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Shixin Ma, Siva Karthik Varanasi, and Susan M. Kaech
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0301 basic medicine ,T cell ,Immunology ,Biology ,CD8-Positive T-Lymphocytes ,03 medical and health sciences ,0302 clinical medicine ,Metabolomics ,Isotopes ,Immunity ,medicine ,Immunology and Allergy ,Effector ,Metabolism ,Phenotype ,Cell biology ,030104 developmental biology ,Infectious Diseases ,medicine.anatomical_structure ,Glucose ,030220 oncology & carcinogenesis ,bacteria ,Flux (metabolism) ,CD8 - Abstract
Our knowledge of T cell metabolism relies primarily on studies performed in vitro that may not fully recapitulate physiological conditions in vivo. In this issue of Immunity, Ma et al. find that the in vivo environment dictates the metabolic phenotype of effector CD8+ T cells—particularly their glucose utilization.
- Published
- 2019
36. A Hierarchical Network for Diverse Trajectory Proposals
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Brojeshwar Bhowrnick, Saket Saurav, K. Madhava Krishna, Gourav Kumar, M. Siva Karthik, N N Sriram, and Abhay Singh
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050210 logistics & transportation ,0209 industrial biotechnology ,Traverse ,Computer science ,05 social sciences ,02 engineering and technology ,Convolutional neural network ,Drone ,020901 industrial engineering & automation ,Human–computer interaction ,Obstacle ,0502 economics and business ,Trajectory ,Robot ,Architecture ,Set (psychology) - Abstract
Autonomous explorative robots frequently encounter scenarios where multiple future trajectories can be pursued. Often these are cases with multiple paths around an obstacle or trajectory options towards various frontiers. Humans in such situations can inherently perceive and reason about the surrounding environment to identify several possibilities of either manoeuvring around the obstacles or moving towards various frontiers. In this work, we propose a 2 stage Convolutional Neural Network architecture which mimics such an ability to map the perceived surroundings to multiple trajectories that a robot can choose to traverse. The first stage is a Trajectory Proposal Network which suggests diverse regions in the environment which can be occupied in the future. The second stage is a Trajectory Sampling network which provides a finegrained trajectory over the regions proposed by Trajectory Proposal Network. We evaluate our framework in diverse and complicated real life settings. For the outdoor case, we use the KITTI dataset and our own outdoor driving dataset. In the indoor setting, we use an autonomous drone to navigate various scenarios and also a ground robot which can explore the environment using the trajectories proposed by our framework. Our experiments suggest that the framework is able to develop a semantic understanding of the obstacles, open regions and identify diverse trajectories that a robot can traverse. Our comparisons portray the performance gain of the proposed architecture over a diverse set of methods against which it is compared.
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- 2019
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37. Uptake of oxidized lipids by the scavenger receptor CD36 promotes lipid peroxidation and dysfunction in CD8+ T cells in tumors
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Taha Merghoub, Michael Downes, Xiaoli Sun, Shihao Xu, Jun Siong Low, April Williams, Yagmur Farsakoglu, Antonio Pinto, Ziyan Xu, Omkar Chaudhary, Ping-Chih Ho, Dan Chen, Wenxi Tang, Bryan McDonald, Roberta Zappasodi, Brinda Emu, Ronald M. Evans, Jedd D. Wolchok, Maxim N. Shokhirev, Susan M. Kaech, Joseph L. Witztum, Haiping Wang, Nada A. Abumrad, Siva Karthik Varanasi, Isabell Schulze, Guoliang Cui, Patricia Rodríguez-Morales, and Victoria Tripple
- Subjects
0301 basic medicine ,Tumor microenvironment ,biology ,Tumor-infiltrating lymphocytes ,CD36 ,Immunology ,hemic and immune systems ,GPX4 ,Lipid peroxidation ,03 medical and health sciences ,chemistry.chemical_compound ,030104 developmental biology ,0302 clinical medicine ,Infectious Diseases ,chemistry ,030220 oncology & carcinogenesis ,Cancer research ,biology.protein ,Immunology and Allergy ,Cytotoxic T cell ,lipids (amino acids, peptides, and proteins) ,Scavenger receptor ,CD8 - Abstract
Summary A common metabolic alteration in the tumor microenvironment (TME) is lipid accumulation, a feature associated with immune dysfunction. Here, we examined how CD8+ tumor infiltrating lymphocytes (TILs) respond to lipids within the TME. We found elevated concentrations of several classes of lipids in the TME and accumulation of these in CD8+ TILs. Lipid accumulation was associated with increased expression of CD36, a scavenger receptor for oxidized lipids, on CD8+ TILs, which also correlated with progressive T cell dysfunction. Cd36−/− T cells retained effector functions in the TME, as compared to WT counterparts. Mechanistically, CD36 promoted uptake of oxidized low-density lipoproteins (OxLDL) into T cells, and this induced lipid peroxidation and downstream activation of p38 kinase. Inhibition of p38 restored effector T cell functions in vitro, and resolution of lipid peroxidation by overexpression of glutathione peroxidase 4 restored functionalities in CD8+ TILs in vivo. Thus, an oxidized lipid-CD36 axis promotes intratumoral CD8+ T cell dysfunction and serves as a therapeutic avenue for immunotherapies.
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- 2021
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38. Design and fabrication of WSe2/CNTs hybrid network: A highly efficient and stable electrodes for dye sensitized solar cells (DSSCs)
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P. Siva Karthik, J. Balaji, B. Rajeshkanna, and M. Durairasan
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Materials science ,Fabrication ,Nanostructure ,Mechanical Engineering ,Composite number ,Nanoparticle ,Nanotechnology ,02 engineering and technology ,General Chemistry ,Carbon nanotube ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,Anode ,law.invention ,Dye-sensitized solar cell ,law ,Electrode ,Materials Chemistry ,Electrical and Electronic Engineering ,0210 nano-technology - Abstract
This study presents a rational-designed structure and facile strategy to fabricate tungsten selenide/carbon nanotube (WSe2/CNT) hybrid photoanodes as promising anodes for DSSC applications. The fundamental physic-chemical properties proved that the uniform, pure and tubular WSe2/CNT hybrid nanoparticles were produced and WSe2 nanoparticles were anchored the CNT surface successfully. The WSe2/CNT hybrid nanostructure exhibits higher surface area (107.8 m2/g) and pore size (45.3 nm) than compared with pure WSe2 (86.2 m2/g and 19.8 nm). WSe2/CNT composite exhibits enhanced photo-conversion efficiency (8.85%), electro-catalytic activity and high electron life time (87 ns). The improved PCE of the WSe2/CNT composite is due to the CNTs can reduce electron-hole pair recombination and efficiently inhibit the aggregation of WSe2 for fully exposing the active edges. Those outstanding electrochemical performances of WSe2/CNT hybrid can be assigned to its unique nanoarchitecture: the CNT with high conductivity work as the skeleton of WSe2/CNT anode facilitating the electron transfer; the CNT can effectively prevent WSe2 from the aggregation and promote the in-situ growth of WSe2 on CNT. Moreover, the hybrid structure, which can allow for efficient ionic diffusion and easy electrolyte infiltration.
- Published
- 2021
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39. Geometric Image Synthesis
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Hassan Abu Alhaija, Carsten Rother, Siva Karthik Mustikovela, and Andreas Geiger
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Training set ,Artificial neural network ,Computer science ,business.industry ,ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,Rendering (computer graphics) ,Image synthesis ,Computer graphics ,0202 electrical engineering, electronic engineering, information engineering ,020201 artificial intelligence & image processing ,Generalizability theory ,Computer vision ,Segmentation ,Artificial intelligence ,Graphics ,business ,0105 earth and related environmental sciences - Abstract
The task of generating natural images from 3D scenes has been a long standing goal in computer graphics. On the other hand, recent developments in deep neural networks allow for trainable models that can produce natural-looking images with little or no knowledge about the scene structure. While the generated images often consist of realistic looking local patterns, the overall structure of the generated images is often inconsistent. In this work we propose a trainable, geometry-aware image generation method that leverages various types of scene information, including geometry and segmentation, to create realistic looking natural images that match the desired scene structure. Our geometrically-consistent image synthesis method is a deep neural network, called Geometry to Image Synthesis (GIS) framework, which retains the advantages of a trainable method, e.g., differentiability and adaptiveness, but, at the same time, makes a step towards the generalizability, control and quality output of modern graphics rendering engines. We utilize the GIS framework to insert vehicles in outdoor driving scenes, as well as to generate novel views of objects from the Linemod dataset. We qualitatively show that our network is able to generalize beyond the training set to novel scene geometries, object shapes and segmentations. Furthermore, we quantitatively show that the GIS framework can be used to synthesize large amounts of training data which proves beneficial for training instance segmentation models.
- Published
- 2019
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40. iPose: Instance-Aware 6D Pose Estimation of Partly Occluded Objects
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Karl Pertsch, Siva Karthik Mustikovela, Eric Brachmann, Omid Jafari, and Carsten Rother
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Sequence ,Pixel ,business.industry ,Computer science ,010401 analytical chemistry ,ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION ,02 engineering and technology ,Object (computer science) ,01 natural sciences ,Pipeline (software) ,0104 chemical sciences ,0202 electrical engineering, electronic engineering, information engineering ,Clutter ,RGB color model ,020201 artificial intelligence & image processing ,Segmentation ,Computer vision ,Artificial intelligence ,business ,Pose ,ComputingMethodologies_COMPUTERGRAPHICS - Abstract
We address the task of 6D pose estimation of known rigid objects from single input images in scenarios where the objects are partly occluded. Recent RGB-D-based methods are robust to moderate degrees of occlusion. For RGB inputs, no previous method works well for partly occluded objects. Our main contribution is to present the first deep learning-based system that estimates accurate poses for partly occluded objects from RGB-D and RGB input. We achieve this with a new instance-aware pipeline that decomposes 6D object pose estimation into a sequence of simpler steps, where each step removes specific aspects of the problem. The first step localizes all known objects in the image using an instance segmentation network, and hence eliminates surrounding clutter and occluders. The second step densely maps pixels to 3D object surface positions, so called object coordinates, using an encoder-decoder network, and hence eliminates object appearance. The third, and final, step predicts the 6D pose using geometric optimization. We demonstrate that we significantly outperform the state-of-the-art for pose estimation of partly occluded objects for both RGB and RGB-D input.
- Published
- 2019
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41. Elemental Racing
- Author
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Lingala Siva Karthik Reddy, Karthik Koka, Amiya Kumar Dash, and Manjusha Pandey
- Published
- 2019
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42. Geometric Image Synthesis
- Author
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Alhaija, Hassan Abu, Mustikovela, Siva Karthik, Geiger, Andreas, and Rother, Carsten
- Subjects
FOS: Computer and information sciences ,Computer Vision and Pattern Recognition (cs.CV) ,ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION ,Computer Science - Computer Vision and Pattern Recognition - Abstract
The task of generating natural images from 3D scenes has been a long standing goal in computer graphics. On the other hand, recent developments in deep neural networks allow for trainable models that can produce natural-looking images with little or no knowledge about the scene structure. While the generated images often consist of realistic looking local patterns, the overall structure of the generated images is often inconsistent. In this work we propose a trainable, geometry-aware image generation method that leverages various types of scene information, including geometry and segmentation, to create realistic looking natural images that match the desired scene structure. Our geometrically-consistent image synthesis method is a deep neural network, called Geometry to Image Synthesis (GIS) framework, which retains the advantages of a trainable method, e.g., differentiability and adaptiveness, but, at the same time, makes a step towards the generalizability, control and quality output of modern graphics rendering engines. We utilize the GIS framework to insert vehicles in outdoor driving scenes, as well as to generate novel views of objects from the Linemod dataset. We qualitatively show that our network is able to generalize beyond the training set to novel scene geometries, object shapes and segmentations. Furthermore, we quantitatively show that the GIS framework can be used to synthesize large amounts of training data which proves beneficial for training instance segmentation models.
- Published
- 2018
43. Comparison of Two Regimens of Gonadotropin-releasing Hormone Antagonists in Clomiphene-gonadotropin Induced Controlled Ovulation and Intrauterine Insemination Cycles: Randomized Controlled Study
- Author
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Neerja Bhatla, Nutan Aggarwal, Alka Kriplani, Sajja Devendra Siva Karthik, Garima Kachhawa, and Rajesh Khadgawat
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medicine.medical_specialty ,Clomiphene-gonadotropin ,medicine.drug_class ,media_common.quotation_subject ,premature luteinization ,Hormone antagonist ,lcsh:Gynecology and obstetrics ,Gonadotropin-releasing hormone antagonist ,Human chorionic gonadotropin ,Clomifene ,Internal medicine ,medicine ,fixed regimen ,Ovulation ,lcsh:RG1-991 ,media_common ,intrauterine insemination ,gonadotropin-releasing hormone antagonist ,business.industry ,flexible regimen ,Endocrinology ,Reproductive Medicine ,Original Article ,Menotropins ,Gonadotropin ,Luteinizing hormone ,business ,medicine.drug - Abstract
Context: Gonadotropin-releasing hormone (GnRH) antagonists in fixed or flexible regimens are used for prevention of premature luteinizing hormone (LH) surge, however, data comparing these regimens in stimulated intrauterine insemination (IUI) cycles are lacking. Aims: The aim of this study is to evaluate the effectiveness of GnRH antagonists in fixed and flexible regimens on the rate of premature luteinization (PL) and ovulation rate in sequential clomiphene-gonadotropin controlled ovulation–IUI cycles. Settings and Design: This study was conducted at tertiary care center; this was randomized controlled study. Materials and Methods: A total of 45 infertile women randomized into three groups of 15 each received clomiphene citrate + human menopausal gonadotrophin. GnRH antagonist was added according to fixed (n = 15) and flexible (n = 15) protocol. No antagonist in control group (n = 15). PL was defined as LH level ≥10 mIU/ml and progesterone level ≥1.0 ng/ml. Statistical Analysis: Mean values compared using the Student's t-test or one-way analysis of variance. Categorical variables distribution tested using either Pearson's Chi-square or Fisher's exact test as appropriate. Results: Of a total of 45 women, 58% (n = 26) presented with primary and 42% (n = 19) secondary infertility with mean age of 30.8 ± 3.43 years and BMI 26.57 ± 3.22 kg/m2. Fixed regimen (3.7%) showed most reduction in PL compared to flexible (15.38%, P = 0.33) or control (36.67%, P = 0.004). On human chorionic gonadotropin day, mean LH (P = 0.002) and progesterone (P = 0.079) levels in fixed, flexible, and control groups were as follows: 5.04 ± 5.47 mIU/ml, 3.95 ± 4.16 mIU/ml, 9.57 ± 7.91 mIU/ml, and 0.409 ± 0.320 ng/ml, 0.579 ± 0.727 ng/ml, and 1.033 ± 1.022 ng/ml, respectively. Ovulation (P = 0.813) and pregnancy rates (P = 0.99) were 88.9%, 84.6%, and 90% and 22.2%, 19.23%, and 10% in fixed, flexible, and control groups, respectively. Conclusions: Addition of antagonist in any regimen appears to lower PL rates and improve pregnancy rates in controlled ovarian stimulation and IUI cycles.
- Published
- 2018
44. The inflammasome NLRP3 plays a protective role against a viral immunopathological lesion
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Siva Karthik Varanasi, Pranay Dogra, Ujjaldeep Jaggi, M. Lorena Harvey, Fernanda Gimenez, Barry T. Rouse, and Siddheshvar Bhela
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0301 basic medicine ,Chemokine ,Inflammasomes ,Neutrophils ,Angiogenesis ,Interleukin-1beta ,Immunology ,Inflammation ,Herpesvirus 1, Human ,Protective Agents ,Cornea ,Lesion ,Pathogenesis ,03 medical and health sciences ,Immune system ,NLR Family, Pyrin Domain-Containing 3 Protein ,medicine ,Animals ,Immunology and Allergy ,Keratitis ,Innate immune system ,integumentary system ,biology ,business.industry ,Interleukin-18 ,Inflammasome ,Cell Biology ,Th1 Cells ,Mice, Inbred C57BL ,030104 developmental biology ,biology.protein ,Th17 Cells ,Female ,Lymph Nodes ,Inflammation Mediators ,medicine.symptom ,business ,medicine.drug - Abstract
Herpes simplex 1 infection of the eye can cause blindness with lesions in the corneal stroma largely attributable to inflammatory events that include components of both adaptive and innate immunity. Several innate immune responses are triggered by herpes simplex 1, but it is unclear how such innate events relate to the subsequent development of stromal keratitis. In this study, we compared the outcome of herpes simplex 1 ocular infection in mice unable to express NLRP3 because of gene knockout (NLRP3−/−) to that of wild-type mice. The NLRP3−/− mice developed more-severe and earlier stromal keratitis lesions and had higher angiogenesis scores than did infected wild-type animals. In addition, NLRP3−/− mice generated an increased early immune response with heightened chemokines and cytokines, including interleukin-1β and interleukin-18, and elevated recruitment of neutrophils. Increased numbers of CD4+ T cells were seen at later stages of the disease in NLRP3−/− animals. Reduction in neutrophils prevented early onset of the disease in NLRP3−/− animals and lowered levels of bioactive interleukin-1β but did not lower bioactive interleukin-18. In conclusion, our results indicate that NLRP3 has a regulatory and beneficial role in herpetic stromal keratitis pathogenesis.
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- 2015
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45. Role of miR-155 in the Pathogenesis of Herpetic Stromal Keratitis
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Siddheshvar Bhela, Sachin Mulik, John Xu, Siva Karthik Varanasi, Barry T. Rouse, Fernanda Gimenez, Patrick Y. Lu, Ujjaldeep Jaggi, Raphael L. Richardson, and Pradeep B. J. Reddy
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Chemokine ,Corneal Stroma ,Oligonucleotides ,Down-Regulation ,Inflammation ,Herpesvirus 1, Human ,medicine.disease_cause ,Models, Biological ,Virus ,Pathology and Forensic Medicine ,Lesion ,Pathogenesis ,03 medical and health sciences ,0302 clinical medicine ,medicine ,Animals ,Humans ,Gene silencing ,Cell Proliferation ,Receptors, Interferon ,030304 developmental biology ,Mice, Knockout ,0303 health sciences ,biology ,Inositol Polyphosphate 5-Phosphatases ,Regular Article ,Th1 Cells ,Phosphoric Monoester Hydrolases ,Up-Regulation ,3. Good health ,Mice, Inbred C57BL ,MicroRNAs ,Lymphatic system ,Herpes simplex virus ,Immunology ,Keratitis, Herpetic ,biology.protein ,Nanoparticles ,Th17 Cells ,Female ,Chemokines ,medicine.symptom ,030215 immunology - Abstract
Ocular infection with herpes simplex virus 1 can result in a chronic immunoinflammatory stromal keratitis (SK) lesion that is a significant cause of human blindness. A key to controlling SK lesion severity is to identify cellular and molecular events responsible for tissue damage and to manipulate them therapeutically. Potential targets for therapy are miRNAs, but these are minimally explored especially in responses to infection. Here, we demonstrated that Mir155 expression was up-regulated after ocular herpes simplex virus 1 infection, with the increased Mir155 expression occurring mainly in macrophages and CD4 + T cells and to a lesser extent in neutrophils. In vivo studies indicated that Mir155 knockout mice were more resistant to herpes SK with marked suppression of T helper cells type 1 and 17 responses both in the ocular lesions and the lymphoid organs. The reduced SK lesion severity was reflected by increased phosphatidylinositol-3,4,5-trisphosphate 5-phosphatase 1 and interferon-γ receptor α-chain levels in activated CD4 + T cells in the lymph nodes. Finally, in vivo silencing of miR-155 by the provision of antagomir-155 nanoparticles to herpes simplex virus 1–infected mice led to diminished SK lesions and corneal vascularization. In conclusion, our results indicate that miR-155 contributes to the pathogenesis of SK and represents a promising target to control SK severity.
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- 2015
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46. On the role of retinoic acid in virus induced inflammatory response in cornea
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Siva Karthik Varanasi, Ujjaldeep Jaggi, Barry T. Rouse, and Siddheshvar Bhela
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0301 basic medicine ,Regulatory T cell ,Immunology ,Retinoic acid ,Down-Regulation ,Tretinoin ,Herpesvirus 1, Human ,Biology ,medicine.disease_cause ,Microbiology ,T-Lymphocytes, Regulatory ,Virus ,Proinflammatory cytokine ,Lesion ,Cornea ,03 medical and health sciences ,chemistry.chemical_compound ,Mice ,0302 clinical medicine ,Immune system ,medicine ,Animals ,Inflammation ,Effector ,Forkhead Transcription Factors ,Receptors, Interleukin-6 ,Disease Models, Animal ,030104 developmental biology ,Infectious Diseases ,medicine.anatomical_structure ,Herpes simplex virus ,chemistry ,Cancer research ,Keratitis, Herpetic ,Female ,medicine.symptom ,030215 immunology - Abstract
Ocular infection with herpes simplex virus (HSV) can result in a chronic immune inflammatory lesion that is a significant cause of human blindness. A key to controlling stromal keratitis (SK) lesion severity is to identify cellular and molecular events responsible for tissue damage and to counteract them. One potentially useful approach to achieve such therapy is Retinoic Acid (RA). Here we show that RA therapy reduces the severity of SK by having inhibitory effects on the T effector subtypes responsible for orchestrating SK. RA also served to stabilize the function of regulatory T cell (Treg) which counteract inflammatory cell activity. The Treg stabilizing effect was demonstrated by in vitro studies where RA was shown to retain Foxp3 expression when exposed to proinflammatory conditions such as IL-12 and IL-6+TGF-β. in vivo studies revealed that RA exerted its stabilizing effects by downregulating IL-6R expression on Treg after HSV-1 infection and this helped to control the progression of SK. Since the therapy was effective when used both early and after the initiation of lesions, it may represent a valuable means of therapy when used alone or along with additional therapies.
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- 2018
47. Optimized local call routing
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R Siva Karthik, G Shoba, and S B Prapulla
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Call management ,Session Initiation Protocol ,Voice over IP ,Computer science ,business.industry ,computer.internet_protocol ,Network packet ,ComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKS ,020302 automobile design & engineering ,02 engineering and technology ,SIP trunking ,0203 mechanical engineering ,Femtocell ,business ,Host (network) ,computer ,Local call ,Computer network - Abstract
The smartphone industry has gained a large user base since the digital revolution. Due to this, even the Telecommunication operators have had a surge in customers. This has led to call tariffs being decided by the operators and frequently users end up paying for more than what they have used. This research paper explores the option of local call routing using femtocells instead of routing the call through a switching center that belongs to a licensed operator. It has been statistically verified that using VoIP based systems based on the Session Initiation Protocol is very efficient in cutting down costs. Gartner predicts that SIP trunking services can slash enterprise telecommunications expenses by up to 50 percent. It is estimated that VoIP systems can reduce initial startup costs to new businesses by up to 90 percent. The Session Initiation Protocol is the ideal candidate for efficient implementation of VoIP-based systems. The general idea being portrayed here is that the traffic generated in a network does not leave the network and terminates in a host within the same network. This ensures that the overhead to reach an operator is minimized. A call manager, specific to VoIP packets, may be developed to address hosts and efficiently route video and audio traffic in between them. Textual data can also be exchanged. This proves very useful during disaster relief as it is possible to set up such systems with relative ease.
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- 2018
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48. The Plasticity and Stability of Regulatory T Cells during Viral-Induced Inflammatory Lesions
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Sarah S. Sloan, Naveen K. Rajasagi, Barry T. Rouse, Ujjaldeep Jaggi, Siddheshvar Bhela, and Siva Karthik Varanasi
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0301 basic medicine ,CD4-Positive T-Lymphocytes ,Adoptive cell transfer ,Cellular differentiation ,Immunology ,Cell Plasticity ,Retinoic acid ,chemical and pharmacologic phenomena ,Tretinoin ,Ascorbic Acid ,Herpesvirus 1, Human ,Biology ,Lymphocyte Activation ,T-Lymphocytes, Regulatory ,Article ,Lesion ,Cornea ,03 medical and health sciences ,chemistry.chemical_compound ,Mice ,T-Lymphocyte Subsets ,medicine ,Immunology and Allergy ,Animals ,Homeodomain Proteins ,Interleukin-2 Receptor alpha Subunit ,FOXP3 ,hemic and immune systems ,Cell Differentiation ,Forkhead Transcription Factors ,Th1 Cells ,Ascorbic acid ,Adoptive Transfer ,Interleukin-12 ,030104 developmental biology ,chemistry ,Interleukin 12 ,Keratitis, Herpetic ,Female ,medicine.symptom ,medicine.drug - Abstract
Ocular infection with HSV causes a chronic T cell–mediated inflammatory lesion in the cornea. Lesion severity is affected by the balance of different CD4 T cell subsets, with greater severity occurring when the activity of regulatory T cells (Tregs) is compromised. In this study, fate-mapping mice were used to assess the stability of Treg function in ocular lesions. We show that cells that were once Foxp3+ functional Tregs may lose Foxp3 and become Th1 cells that could contribute to lesion expression. The instability primarily occurred with IL-2Rlo Tregs and was shown, in part, to be the consequence of exposure to IL-12. Lastly, in vitro–generated induced Tregs (iTregs) were shown to be highly plastic and capable of inducing stromal keratitis when adoptively transferred into Rag1−/− mice, with 95% of iTregs converting into ex-Tregs in the cornea. This plasticity of iTregs could be prevented when they were generated in the presence of vitamin C and retinoic acid. Importantly, adoptive transfer of these stabilized iTregs to HSV-1–infected mice prevented the development of stromal keratitis lesions more effectively than did control iTregs. Our results demonstrate that CD25lo Treg and iTreg instability occurs during a viral immunoinflammatory lesion and that its control may help to avoid lesion chronicity.
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- 2017
49. Proteomics of Melanoma Response to Immunotherapy Reveals Mitochondrial Dependence
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Erez N. Baruch, Siva Karthik Varanasi, Jacob Schachter, Gali Yanovich-Arad, Ruveyda Ayasun, Iris Barshack, Susan M. Kaech, Shihao Xu, Rona Ortenberg, Michal Harel, Georgina D. Barnabas, Marcus Bosenberg, Kailash Chandra Mangalhara, Tamar Geiger, Eyal Greenberg, Mariya Mardamshina, Victoria Tripple, Michal J. Besser, Liat Anafi, Gerald S. Shadel, Ettai Markovits, Naama Knafo, Anjana Shenoy, May Arama-Chayoth, Shira Ashkenazi, and Gal Markel
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Adult ,Male ,Proteomics ,Skin Neoplasms ,T-Lymphocytes ,medicine.medical_treatment ,Programmed Cell Death 1 Receptor ,Biology ,Article ,General Biochemistry, Genetics and Molecular Biology ,Cohort Studies ,Mice ,Young Adult ,03 medical and health sciences ,Lymphocytes, Tumor-Infiltrating ,0302 clinical medicine ,Immune system ,Antigens, Neoplasm ,Cell Line, Tumor ,medicine ,Immunologic Factors ,Animals ,Humans ,Melanoma ,Aged ,030304 developmental biology ,Aged, 80 and over ,0303 health sciences ,Tumor-infiltrating lymphocytes ,Immunogenicity ,Lipid metabolism ,Immunotherapy ,Middle Aged ,Lipid Metabolism ,medicine.disease ,Adoptive Transfer ,Mitochondria ,Mice, Inbred C57BL ,Treatment Outcome ,Proteome ,Cancer research ,Female ,030217 neurology & neurosurgery - Abstract
Summary Immunotherapy has revolutionized cancer treatment, yet most patients do not respond. Here, we investigated mechanisms of response by profiling the proteome of clinical samples from advanced stage melanoma patients undergoing either tumor infiltrating lymphocyte (TIL)-based or anti- programmed death 1 (PD1) immunotherapy. Using high-resolution mass spectrometry, we quantified over 10,300 proteins in total and ∼4,500 proteins across most samples in each dataset. Statistical analyses revealed higher oxidative phosphorylation and lipid metabolism in responders than in non-responders in both treatments. To elucidate the effects of the metabolic state on the immune response, we examined melanoma cells upon metabolic perturbations or CRISPR-Cas9 knockouts. These experiments indicated lipid metabolism as a regulatory mechanism that increases melanoma immunogenicity by elevating antigen presentation, thereby increasing sensitivity to T cell mediated killing both in vitro and in vivo. Altogether, our proteomic analyses revealed association between the melanoma metabolic state and the response to immunotherapy, which can be the basis for future improvement of therapeutic response.
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- 2019
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50. iPose: Instance-Aware 6D Pose Estimation of Partly Occluded Objects
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Jafari, Omid Hosseini, Mustikovela, Siva Karthik, Pertsch, Karl, Brachmann, Eric, and Rother, Carsten
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FOS: Computer and information sciences ,Computer Vision and Pattern Recognition (cs.CV) ,Computer Science - Computer Vision and Pattern Recognition ,ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION ,ComputingMethodologies_COMPUTERGRAPHICS - Abstract
We address the task of 6D pose estimation of known rigid objects from single input images in scenarios where the objects are partly occluded. Recent RGB-D-based methods are robust to moderate degrees of occlusion. For RGB inputs, no previous method works well for partly occluded objects. Our main contribution is to present the first deep learning-based system that estimates accurate poses for partly occluded objects from RGB-D and RGB input. We achieve this with a new instance-aware pipeline that decomposes 6D object pose estimation into a sequence of simpler steps, where each step removes specific aspects of the problem. The first step localizes all known objects in the image using an instance segmentation network, and hence eliminates surrounding clutter and occluders. The second step densely maps pixels to 3D object surface positions, so called object coordinates, using an encoder-decoder network, and hence eliminates object appearance. The third, and final, step predicts the 6D pose using geometric optimization. We demonstrate that we significantly outperform the state-of-the-art for pose estimation of partly occluded objects for both RGB and RGB-D input.
- Published
- 2017
- Full Text
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