1
|
Kovilapu UB, Dudhal R, Maheshwari S, Dhagat P, Mishra UK. Chemical abscess post vein of Galen aneurysmal malformation embolisation with ethylene vinyl alcohol copolymer. SA J Radiol 2024; 28:2841. [PMID: 38725970 PMCID: PMC11079415 DOI: 10.4102/sajr.v28i1.2841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Accepted: 03/15/2024] [Indexed: 05/12/2024] Open
Abstract
Vein of Galen aneurysmal malformation (VGAM) is a rare congenital malformation characterised by arteriovenous fistulas between primitive choroidal arteries and the median prosencephalic vein, the embryonic precursor to the vein of Galen. Endovascular techniques have changed the management of these patients with improved prognosis. An eight-month-old with VGAM managed by endovascular embolisation using ethylene vinyl alcohol copolymer (EVOH) developed a chemical abscess - a rare complication. It was managed conservatively and showed promising clinical outcome. Contribution Chemical abscesses following EVOH embolisation are scarce - with imaging differentials, which include brain abscess and onyx granuloma. Knowledge and successful identification of this entity are essential as its management as prognoses differ. Chemical abscess is managed conservatively and has a good prognosis.
Collapse
Affiliation(s)
| | - Rahul Dudhal
- Department of Radiodiagnosis, Armed Forces Medical College, Pune, India
| | | | - Peeyush Dhagat
- Department of Radiodiagnosis, Armed Forces Medical College, Pune, India
| | - Umesh K. Mishra
- Department of Radiodiagnosis, Armed Forces Medical College, Pune, India
| |
Collapse
|
2
|
Santhanam V, Modi P, Mishra UK, Jahan I, Ramesh NG, Deep S. Rational design and synthesis of novel triazole- and tetrazole-fused iminosugars as potential inhibitors of amyotrophic lateral sclerosis (ALS) linked SOD1 aggregation. Int J Biol Macromol 2023; 253:126900. [PMID: 37714236 DOI: 10.1016/j.ijbiomac.2023.126900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Revised: 08/25/2023] [Accepted: 09/12/2023] [Indexed: 09/17/2023]
Abstract
In this manuscript we report the first example of an iminosugar that inhibits superoxide dismutase fibrillation associated with the amyotrophic lateral sclerosis (ALS). The present work involves synthesis of novel triazole and tetrazole embedded iminosugars, synthesized in 11-13 high yielding steps starting from readily available tri-O-benzyl-D-glucal and proceeding through a concomitant azidation - thermal intramolecular [3 + 2] cycloaddition reaction as the key step. One of these pre-designed iminosugars was found to inhibit fibrillation of SOD1 and also has shown propensity to break pre-formed fibrils. Docking and MD simulation studies suggest that the most probable interaction of this compound is a hydrogen bonding with Arg69, a loop IV residue of SOD1, which has a crucial role in stabilizing the native conformation of SOD1.
Collapse
Affiliation(s)
- Venkatesan Santhanam
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| | - Priya Modi
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| | - Umesh K Mishra
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| | - Ishrat Jahan
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| | - Namakkal G Ramesh
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India.
| | - Shashank Deep
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India.
| |
Collapse
|
3
|
Mishra UK, Sanghvi YS, Abhiraj R, Sampathkumar SG, Ramesh NG. An expeditious synthesis of novel DNA nucleobase mimics of (+)-anisomycin. Carbohydr Res 2022; 520:108645. [PMID: 35964481 DOI: 10.1016/j.carres.2022.108645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 08/01/2022] [Accepted: 08/01/2022] [Indexed: 11/15/2022]
Abstract
A glycal based expeditious synthesis of novel nucleoside analogues of (+)-anisomycin is reported. Readily available tri-O-benzyl-D-glucal was converted to a partially protected trihydroxypyrrolidine that is used as a common scaffold for the introduction of various nucleobases at the primary hydroxyl centre. Nucleoside analogues possessing all four DNA bases have been synthesized. Selective acetylation at C3 position was carried out with two of these unnatural nucleosides in order to mimic the structure of (+)-anisomycin. Cytotoxicity studies of some of these nucleosides showed that they display weaker activity on HeLa cells than Ara-C.
Collapse
Affiliation(s)
- Umesh K Mishra
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, 110016, India
| | - Yogesh S Sanghvi
- Rasayan Inc., 2802 Crystal Ridge Road, Encinitas, CA, 92024-6615, USA
| | - R Abhiraj
- Laboratory of Chemical Biology, National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | | | - Namakkal G Ramesh
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, 110016, India.
| |
Collapse
|
4
|
Wang J, Li H, Li H, Keller S, Mishra UK, Nener BD, Parish G, Atkin R. Effects of surface oxidation on the pH-dependent surface charge of oxidized aluminum gallium nitride. J Colloid Interface Sci 2021; 603:604-614. [PMID: 34217948 DOI: 10.1016/j.jcis.2021.06.126] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 06/10/2021] [Accepted: 06/21/2021] [Indexed: 10/21/2022]
Abstract
HYPOTHESIS The properties of the oxidized surface for common materials, such as silicon and titanium, are known to be markedly different from the reduced surface. We hypothesize that surface-oxidized aluminum gallium nitride ((oxidized-AlGaN)/GaN) surface charge behavior is different to unoxidized AlGaN (with ultrathin native oxide only), which can be validated via surfactant adsorption. Understanding these differences will explain why (oxidized-AlGaN)/GaN-based sensors are better performing than AlGaN ones, which has been previously demonstrated but not understood. EXPERIMENTS The surface of an AlGaN/GaN structure was oxidized with hot piranha solution and oxygen plasma. AFM force measurements and imaging were performed to probe the charge properties of the surface in aqueous solutions of varying pH containing only an acid or base, or with an added ionic surfactant: cationic cetyltrimethylammonium bromide (CTAB) or anionic sodium dodecylsulfate (SDS). FINDINGS The (oxidized-AlGaN)/GaN surface is positively charged at pH 4 and pH 5.5, although pH 5.5 should be close to the isoelectric point of the surface. The surface is negatively charged at pH 10 and pH 12, and sufficiently charged to attract cooperative adsorption of CTAB aggregates at pH 12. At pH 2, the evidence is inconclusive, but the surface is most likely positively charged. Compared to unoxidized AlGaN, the (oxidized-AlGaN)/GaN surface shows a wider range of surface charge magnitude over pH values between 2 and 12. This suggests that the (oxidized-AlGaN)/GaN surface has a higher surface hydroxyl group density than unoxidized AlGaN, which explains the higher sensitivity for pH sensors based on (oxidized-AlGaN)/GaN structures.
Collapse
Affiliation(s)
- Jianan Wang
- School of Engineering, The University of Western Australia, Perth, WA 6009, Australia; School of Molecular Sciences, The University of Western Australia, Perth, WA 6009, Australia.
| | - Hua Li
- School of Molecular Sciences, The University of Western Australia, Perth, WA 6009, Australia; Centre for Microscopy, Characterisation and Analysis, The University of Western Australia, Perth, WA 6009, Australia.
| | - Haoran Li
- Department of Electrical and Computer Engineering, University of California Santa Barbara, Santa Barbara, CA 93106-9560, USA.
| | - Stacia Keller
- Department of Electrical and Computer Engineering, University of California Santa Barbara, Santa Barbara, CA 93106-9560, USA.
| | - Umesh K Mishra
- Department of Electrical and Computer Engineering, University of California Santa Barbara, Santa Barbara, CA 93106-9560, USA.
| | - Brett D Nener
- School of Engineering, The University of Western Australia, Perth, WA 6009, Australia.
| | - Giacinta Parish
- School of Engineering, The University of Western Australia, Perth, WA 6009, Australia.
| | - Rob Atkin
- School of Molecular Sciences, The University of Western Australia, Perth, WA 6009, Australia.
| |
Collapse
|
5
|
Wang J, Zhang X, Li H, Wang C, Li H, Keller S, Mishra UK, Nener BD, Parish G, Atkin R. pH-Dependent surface charge at the interfaces between aluminum gallium nitride (AlGaN) and aqueous solution revealed by surfactant adsorption. J Colloid Interface Sci 2021; 583:331-339. [DOI: 10.1016/j.jcis.2020.09.036] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 09/10/2020] [Accepted: 09/11/2020] [Indexed: 12/16/2022]
|
6
|
Abstract
Design of Janus-faced or double-headed homoazanucleosides with the possibility to undergo self-organization through base pairing has been conceptualized and accomplished. The synthetic strategy demonstrates the unique ability to introduce two similar or complementary nucleobases on opposite arms of a chiral polyhydroxypyrrolidine while also ensuring that their faces are anti to each other to allow only intermolecular interactions between the nucleobases, an essential requisite for self-assembly. Single-crystal X-ray structures were determined for all three types of homoazanucleosides, one possessing two adenine molecules, the other with two thymine moieties, and the third containing both adenine and thymine. The crystal structures of all three display noncovalent interactions, including Watson-Crick base pairing, Hoogsteen H-bonding, and π-π stacking, resulting in unusual supramolecular patterns. The most striking supramolecular motif among them, which emerged from the crystal structure of the homoazanucleoside containing both adenine and thymine, is a left-handed helix formed through Watson-Crick pairing between nucleobases. The present study thus forms a prelude to the design of Janus-faced building blocks to establish helical pillars as well as lateral branches that together define a three-dimensional (3D) lattice. The ready accessibility of these molecules is expected to spur the next generation of discoveries in the design of functional nanomaterials.
Collapse
Affiliation(s)
- Umesh K Mishra
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| | - Yogesh S Sanghvi
- Rasayan Inc., 2802 Crystal Ridge Road, Encinitas, California 92024-6615, United States
| | - Martin Egli
- Department of Biochemistry, School of Medicine, Vanderbilt University, Nashville, Tennessee 37232, United States
| | - Namakkal G Ramesh
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| |
Collapse
|
7
|
Mishra UK, Ramesh NG. A glycal based approach to the synthesis of (+)-bulgecinine, 3-hydroxy-2,5-dihydroxymethylpyrrolidine and 2-oxapyrrolizidin-3-one. Carbohydr Res 2020; 489:107931. [PMID: 32088502 DOI: 10.1016/j.carres.2020.107931] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Revised: 01/29/2020] [Accepted: 01/29/2020] [Indexed: 11/25/2022]
Abstract
A glycal based synthesis of (+)-bulgecinine, 3-hydroxy-2,5-dihydroxymethylpyrrolidine and 2-oxapyrrolizidin-3-ones proceeding through a common intermediate is reported. The key step in the work presented here is a two-step conversion of 4,6-di-O-benzyl-d-glucal to 2,3-dideoxy-2-tosylamido-d-glucose. This manuscript reports the first carbohydrate based approach to the synthesis of (+)-bulgecinine and the whole sequence has been accomplished with complete stereochemical integrity without the formation of mixture of products in any of these steps.
Collapse
Affiliation(s)
- Umesh K Mishra
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, 110016, India
| | - Namakkal G Ramesh
- Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, 110016, India.
| |
Collapse
|
8
|
Pasayat SS, Gupta C, Wang Y, DenBaars SP, Nakamura S, Keller S, Mishra UK. Compliant Micron-Sized Patterned InGaN Pseudo-Substrates Utilizing Porous GaN. Materials (Basel) 2020; 13:ma13010213. [PMID: 31947918 PMCID: PMC6981930 DOI: 10.3390/ma13010213] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 12/18/2019] [Accepted: 01/01/2020] [Indexed: 12/03/2022]
Abstract
The compliant behavior of densely packed 10 × 10 µm2 square patterned InGaN layers on top of porous GaN is demonstrated. The elastic relaxation of the InGaN layers is enabled by the low stiffness of the porous GaN under layer. High resolution X-ray diffraction measurements show that upon InGaN re-growths on these InGaN-on-porous GaN pseudo-substrates, not only was the regrown layer partially relaxed, but the degree of relaxation of the InGaN pseudo-substrate layer on top of the porous GaN also showed an increase in the a-lattice constant. Furthermore, methods to improve the surface morphology of the InGaN layers grown by metal-organic chemical vapor deposition (MOCVD) were explored in order to fabricate InGaN pseudo-substrates for future optoelectronic and electronic devices. The largest a-lattice constant demonstrated in this study using this improved method was 3.209 Å, corresponding to a fully relaxed InGaN film with an indium composition of 0.056.
Collapse
Affiliation(s)
- Shubhra S. Pasayat
- Department of Electrical and Computer Engineering, University of California Santa Barbara, Santa Barbara, CA 93106, USA; (C.G.); (S.P.D.); (S.N.); (S.K.); (U.K.M.)
- Correspondence:
| | - Chirag Gupta
- Department of Electrical and Computer Engineering, University of California Santa Barbara, Santa Barbara, CA 93106, USA; (C.G.); (S.P.D.); (S.N.); (S.K.); (U.K.M.)
| | - Yifan Wang
- Department of Physics, University of California, Santa Barbara, CA 93106, USA;
| | - Steven P. DenBaars
- Department of Electrical and Computer Engineering, University of California Santa Barbara, Santa Barbara, CA 93106, USA; (C.G.); (S.P.D.); (S.N.); (S.K.); (U.K.M.)
- Materials Department, University of California, Santa Barbara, CA 93106, USA
| | - Shuji Nakamura
- Department of Electrical and Computer Engineering, University of California Santa Barbara, Santa Barbara, CA 93106, USA; (C.G.); (S.P.D.); (S.N.); (S.K.); (U.K.M.)
- Materials Department, University of California, Santa Barbara, CA 93106, USA
| | - Stacia Keller
- Department of Electrical and Computer Engineering, University of California Santa Barbara, Santa Barbara, CA 93106, USA; (C.G.); (S.P.D.); (S.N.); (S.K.); (U.K.M.)
| | - Umesh K. Mishra
- Department of Electrical and Computer Engineering, University of California Santa Barbara, Santa Barbara, CA 93106, USA; (C.G.); (S.P.D.); (S.N.); (S.K.); (U.K.M.)
| |
Collapse
|
9
|
Asadnia M, Myers M, Umana-Membreno GA, Sanders TM, Mishra UK, Nener BD, Baker MV, Parish G. Ca 2+ detection utilising AlGaN/GaN transistors with ion-selective polymer membranes. Anal Chim Acta 2017; 987:105-110. [PMID: 28916033 DOI: 10.1016/j.aca.2017.07.066] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 07/26/2017] [Accepted: 07/28/2017] [Indexed: 01/06/2023]
Abstract
We demonstrate highly selective and sensitive potentiometric ion sensors for calcium ion detection, operated without the use of a reference electrode. The sensors consist of AlGaN/GaN heterostructure-based transistor devices with chemical functionalisation of the gate area using poly (vinylchloride)-based (PVC) membranes having high selectivity towards calcium ions, Ca2+. The sensors exhibited stable and rapid responses when introduced to various concentrations of Ca2+. In both 0.01 M KCl and 0.01 M NaCl ionic strength buffer solutions, the sensors exhibited near Nernstian responses with detection limits of less than 10-7 M, and a linear response range between 10-7-10-2 M. Also, detection limits of less than 10-6 M were achieved for the sensors in both 0.01 M MgCl2 and 0.01 M LiCl buffer solutions. AlGaN/GaN-based devices for Ca2+ detection demonstrate excellent selectivity and response range for a wide variety of applications. This work represents an important step towards multi-ion sensing using arrays of ion-selective field effect transistor (ISFET) devices.
Collapse
Affiliation(s)
- Mohsen Asadnia
- School of Electrical, Electronic and Computer Engineering, The University of Western Australia, 35 Stirling Hwy., Perth, WA 6009, Australia; Department of Engineering, Macquarie University, NSW 2109, Australia
| | - Matthew Myers
- School of Molecular Sciences, The University of Western Australia, 35 Stirling Hwy., Perth, WA 6009, Australia; CSIRO Energy Flagship, Kensington, WA 6151, Australia
| | - Gilberto A Umana-Membreno
- School of Electrical, Electronic and Computer Engineering, The University of Western Australia, 35 Stirling Hwy., Perth, WA 6009, Australia
| | - Tarun M Sanders
- School of Electrical, Electronic and Computer Engineering, The University of Western Australia, 35 Stirling Hwy., Perth, WA 6009, Australia
| | - Umesh K Mishra
- Department of Electrical and Computer Engineering, University of California, Santa Barbara, CA 93106, USA
| | - Brett D Nener
- School of Electrical, Electronic and Computer Engineering, The University of Western Australia, 35 Stirling Hwy., Perth, WA 6009, Australia
| | - Murray V Baker
- School of Molecular Sciences, The University of Western Australia, 35 Stirling Hwy., Perth, WA 6009, Australia
| | - Giacinta Parish
- School of Electrical, Electronic and Computer Engineering, The University of Western Australia, 35 Stirling Hwy., Perth, WA 6009, Australia.
| |
Collapse
|
10
|
Prasad K, Johari S, Gorthi SP, Sarkar RS, Prabhakar S, Mishra UK, Bhatnagar S. Abstract 3369: Intravenous Autologous Bone Marrow Derived Stem Cell Therapy for Patients with Subacute Ischemic Stroke (InVeST): A Multi-Centric Randomized Controlled Trial. Stroke 2012. [DOI: 10.1161/str.43.suppl_1.a3369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background & Objective
We have completed a randomized controlled clinical trial (CTRI-PROVCTRI/2008/091/00046) to evaluate the safety and efficacy of administering bone marrow mononuclear cells intravenously to patients with subacute ischemic stroke.
Methods
A total 120 consecutive, eligible and consenting patients, aged 18 to 75 years with ischemic stroke involving MCA or ACA territory infarct between 7 to <30 days of onset of stroke with moderate severity in stable condition were recruited from 31 January 2009 to 16 June 2010. Patients were randomly allocated by central telephone/fax/email. For stem cell arm, bone marrow has been aspirated from iliac crest and the harvested mononuclear cells infused into antecubital vein. Outcome measures for safety are immediate reactions after cell infusion and evidence of tumor formation at one year in whole body FDG-PET scan. Efficacy measurement time points are 7 (±2 days), 90(-7 to +14 days), 180 (-7 to +28 days) and 365 (-7 to +28 days) NIHSS, BI, mRS, MRI, PET scan and EEG. BI and mRS were measured by blinded assessors centrally on telephone. Primary outcome is modified BI score at six months post-randomisation.
Results
Stem cell arm has been administered bone marrow mononuclear cells (mean 280.73 million with CD34+ mean 2.85 million). Central telephonic follow up has been completed in 117 patients. Data on SAEs, clinical outcome (mRS, BI, NIHSS), cerebral infarct volume, whole body FDG-PET scan and EEG will be presented.
Conclusion
Intravenous bone marrow MNC therapy is safe in patients of subacute stroke. Further results will be presented.
Collapse
Affiliation(s)
| | - S. Johari
- Rsch&Referral Hosp, New Delhi, India
| | | | | | | | - U K Mishra
- Sanjay Gandhi Postgraduate Institute of Med Sciences, Lucknow, India
| | | |
Collapse
|
11
|
Keller S, Dora Y, Chowdhury S, Wu F, Chen X, DenBaars SP, Speck JS, Mishra UK. Growth and characterization of N-polar GaN and AlGaN/GaN HEMTs on (111) silicon. ACTA ACUST UNITED AC 2011. [DOI: 10.1002/pssc.201000958] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
12
|
Ben-Yaacov I, Seck YK, DenBaars SP, Hu EL, Mishra UK. Analysis of Leakage Currents in AlGaN/GaN Current Aperture Vertical Electron Transistors (CAVETs). ACTA ACUST UNITED AC 2011. [DOI: 10.1557/proc-764-c4.8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
AbstractA complete analysis of leakage currents in AlGaN/GaN Current Aperture Vertical Electron Transistors (CAVETs) with regrown aperture and source regions was carried out. The total observed leakage current was found to be a combination of both gate leakage and source leakage. Two paths for source leakage have been identified; electrons passing directly through the insulating layer to the drain region as well as electrons traveling through the aperture but underneath the 2DEG at the AlGaN/GaN interface. Source leakage through the insulating layer resulted from pits formed at the onset of regrowth, as the sample was heated to growth temperature, and was successfully eliminated by optimizing regrowth conditions. Source leakage underneath the 2DEG occurred when the unintentionally doped (UID) GaN layer above the insulating layer was not fully depleted and could be eliminated by reducing the thickness of the UID GaN layer. Gate leakage has been attributed to the enhanced incorporation of n-type impurities inside as well as above the aperture region during regrowth, resulting in a narrowing ofthegateSchottkybarrier.
Collapse
|
13
|
Kumar S, Negi MPS, Sharma VP, Shukla R, Dev R, Mishra UK. Efficacy of two multimodal treatments on physical strength of occupationally subgrouped male with low back pain. J Back Musculoskelet Rehabil 2010; 22:179-88. [PMID: 20023348 DOI: 10.3233/bmr-2009-0234] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVES Some occupations are more prone to low back pain (LBP) due to their static work postures and work place design. Multidisciplinary pain programs have shown their effectiveness in the management of LBP in general population but which treatment and which segment of the population will be benefited more was not investigated yet. This study determines the effect of two treatment protocols on five occupationally subgrouped male LBP patients. METHODS A total of 102 occupational male, 20-40 yrs of age, with sub-acute or chronic nonspecific LBP were randomized and treated either with conventional treatment a combination of two electrotherapy (ultrasound and short wave diathermy) and one exercise therapy (lumbar strengthening exercises) or dynamic muscular stabilization techniques (DMST) an active approach of stabilizing training. At the end of the treatment, subjects of both the groups were further stratified in five subgroups on the basis of their occupation. The pain was the primary outcome measure while physical strength [back pressure changes (BPC) and abdominal pressure changes (APC)] the secondary. RESULTS The Pain, BPC and APC of all subgroups improved significantly (P < 0.01) in the both treatments but more in DMST. For each variable, improvement in subgroups differed within and between the treatments. Overall improvement in all assessed variables were evident on Desk workers followed by Shop keepers the most while BPC of Movement job, APC of Others and Pain of Sedentary and Shop keepers improved the least. CONCLUSIONS Study concluded that for the management of occupational LBP, DMST is more effective than conventional treatment. The Pain of Sedentary and Shopkeepers and physical strength of Movement job and Others may need more clinical attention. Findings of this study may be helpful in the management of occupational LBP.
Collapse
Affiliation(s)
- S Kumar
- Department of Physical Medicine and Rehabilitation, Chatrapati Sahuji Maharaj Medical University, Lucknow, India.
| | | | | | | | | | | |
Collapse
|
14
|
Schaake CA, Fichtenbaum NA, Neufeld CJ, Keller S, DenBaars SP, Speck JS, Mishra UK. M-plane InGaN/GaN light emitting diodes fabricated by MOCVD regrowth onc-plane patterned templates. ACTA ACUST UNITED AC 2008. [DOI: 10.1002/pssc.200779284] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
15
|
|
16
|
Chichibu SF, Uedono A, Onuma T, Haskell BA, Chakraborty A, Koyama T, Fini PT, Keller S, Denbaars SP, Speck JS, Mishra UK, Nakamura S, Yamaguchi S, Kamiyama S, Amano H, Akasaki I, Han J, Sota T. Origin of defect-insensitive emission probability in In-containing (Al,In,Ga)N alloy semiconductors. Nat Mater 2006; 5:810-6. [PMID: 16951678 DOI: 10.1038/nmat1726] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2005] [Accepted: 07/12/2006] [Indexed: 05/11/2023]
Abstract
Group-III-nitride semiconductors have shown enormous potential as light sources for full-colour displays, optical storage and solid-state lighting. Remarkably, InGaN blue- and green-light-emitting diodes (LEDs) emit brilliant light although the threading dislocation density generated due to lattice mismatch is six orders of magnitude higher than that in conventional LEDs. Here we explain why In-containing (Al,In,Ga)N bulk films exhibit a defect-insensitive emission probability. From the extremely short positron diffusion lengths (<4 nm) and short radiative lifetimes of excitonic emissions, we conclude that localizing valence states associated with atomic condensates of In-N preferentially capture holes, which have a positive charge similar to positrons. The holes form localized excitons to emit the light, although some of the excitons recombine at non-radiative centres. The enterprising use of atomically inhomogeneous crystals is proposed for future innovation in light emitters even when using defective crystals.
Collapse
Affiliation(s)
- Shigefusa F Chichibu
- Institute of Applied Physics and 21st Century COE Office, Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8573, Japan.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Abstract
Accurate and timely diagnosis of early onset neonatal sepsis remains challenging to the clinician and the laboratory. A test with a rapid turnaround time with 100% sensitivity, rather than high specificity, which allows accurate diagnosis and appropriate antimicrobial treatment or which allows antibiotics to be safely withheld in non-infected infants, is desirable. Many potential markers (acute phase reactants, cell surface markers, cytokines) are not routinely available to the laboratory, and most likely combinations of markers will ensure greater diagnostic accuracy. In the future, molecular biology techniques offer the prospect of rapid identification of both pathogens and antimicrobial resistance markers.
Collapse
Affiliation(s)
- U K Mishra
- Newborn Services, Royal Women's Hospital, Victoria, Australia
| | | | | | | |
Collapse
|
18
|
Schwenzer B, Meier C, Masala O, Seshadri R, DenBaars SP, Mishra UK. Synthesis of luminescing (In,Ga)N nanoparticles from an inorganic ammonium fluoride precursor. ACTA ACUST UNITED AC 2005. [DOI: 10.1039/b418203k] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
19
|
Schwenzer B, Loeffler L, Seshadri R, Keller S, Lange FF, DenBaars SP, Mishra UK. Preparation of indium nitride micro- and nanostructures by ammonolysis of indium oxide. ACTA ACUST UNITED AC 2004. [DOI: 10.1039/b309576b] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
20
|
Venkatesh SK, Phadke RV, Kumar S, Mishra UK. MR appearance of interpeduncular lipoma. Singapore Med J 2003; 44:39-41. [PMID: 12762563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
Interpeduncular lipoma (IPL) is a very rare benign intracranial lesion. Non-invasive diagnosis of this condition is important, as these lesions are usually asymptomatic and are found incidentally. We describe a rare case of IPL in a 35-year-old woman presenting with headache of long duration and a recent increase in severity and frequency of headache. There was no neurological abnormality on clinical examination. MR imaging demonstrated a homogeneous lobulated T1-hyperintense and T2-hypointense lesion in interpeduncular fossa. A T1-weighted fat suppression sequence with chemical shift method confirmed the fatty nature of the lesion. The patient was managed conservatively.
Collapse
Affiliation(s)
- S K Venkatesh
- Department of Diagnostic Imaging, National University Hospital, 5 Lower Kent Ridge Road, Singapore 119074.
| | | | | | | |
Collapse
|
21
|
|
22
|
|
23
|
Sun CK, Chu SW, Tai SP, Keller S, Abare A, Mishra UK, DenBaars SP. Mapping piezoelectric-field distribution in gallium nitride with scanning second-harmonic generation microscopy. Scanning 2001; 23:182-192. [PMID: 11405303 DOI: 10.1002/sca.4950230304] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Taking advantage of the electric field-enhanced second-harmonic generation effect in bulk gallium nitride (GaN) and indium gallium nitride (InGaN) quantum wells, we demonstrated the piezoelectric field distribution mapping in bulk GaN and InGaN multiple-quantum-well (MQW) samples using scanning second-harmonic generation (SHG) microscopy. Scanning SHG microscopy and the accompanying third-harmonic generation (THG) microscopy of the bulk GaN sample were demonstrated using a femtosecond Cr:forsterite laser at a wavelength of 1230 nm. Taking advantage of the off-resonant electric field-enhanced SHG effect and the bandtail state-resonance THG effect, the second- and third-harmonic generation microscopic images obtained revealed the piezoelectric field and bandtail state distributions in a GaN sample. Combined with 720 nm wavelength excited two-photon fluorescence microscopy in the same sample, the increased defect density around the defect area was found to suppress bandedge photoluminescence, to increase yellow luminescence, to increase bandtail state density, and to decrease residue piezoelectric field intensity. Scanning SHG microscopy of the InGaN MQW sample was resonant excited with 800 nm femtosecond pulses from a Ti:sapphire laser in order to suppress SHG contribution from the bulk GaN substrate. Taking advantage of the strong piezoelectric field inside the InGaN quantum well, the wavelength resonant effect, and the electric field-enhanced SHG effect of InGaN quantum wells, resonant scanning SHG microscopy revealed the piezoelectric field distribution inside the wells. Combined with accompanying three-photon fluorescence microscopy from the bulk GaN substrate underneath the quantum wells, the direct correspondence between the piezoelectric field strength inside the quantum well and the substrate quality can be obtained. According to our study, the GaN substrate area with bright bandedge luminescence corresponds to the area with strong SHG signals indicating a higher stained-induced piezoelectric field. These scanning harmonic generation microscopies exhibit superior images of the piezoelectric field and defect state distributions in GaN and InGaN MQWs not available before. Combining with scanning multiphoton fluorescence microscopy, these techniques open new ways for the physical property study of this important material system and can provide interesting details that are not readily available by other microscopic techniques.
Collapse
Affiliation(s)
- C K Sun
- Department of Electrical Engineering, National Taiwan University, Taipei, Republic of China
| | | | | | | | | | | | | |
Collapse
|
24
|
Kalita J, Dhanuka AK, Kishore J, Ayyagiri A, Mathur A, Mishra UK. Herpes simplex myelitis in a patient with acquired immune deficiency syndrome. Neurol India 1998; 46:238-240. [PMID: 29508785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Herpes simplex virus type-I is the commonest cause of focal encephalitis in immunocompetent adults. We report a 35 year old man, who presented with acute ascending myelitis which progressed to encephalitis within one week. The patient's MRI revealed nonhaemorrhagic lesions in frontotemporal areas and midbrain without any evidence of herniation. The CSF was positive for IgM and IgG antibodies against herpes simplex virus 1 (HSV1) and serum was positive for HIV by ELISA and Western blot techniques. The patient died on 18th day of illness due to resistant pseudomonas septicaemia.The presence of disseminated involvement of the central nervous system in HSV infection should raise the suspicion of the HIV coinfection.
Collapse
Affiliation(s)
- J Kalita
- Department of Neurology, Sanjay Gandhi PGIMS, Lucknow, India
| | - A K Dhanuka
- Department of Neurology, Sanjay Gandhi PGIMS, Lucknow, India
| | - J Kishore
- Department of Neurology, Sanjay Gandhi PGIMS, Lucknow, India
| | - A Ayyagiri
- Department of Neurology, Sanjay Gandhi PGIMS, Lucknow, India
| | - A Mathur
- Department of Neurology, Sanjay Gandhi PGIMS, Lucknow, India
| | - U K Mishra
- Department of Neurology, Sanjay Gandhi PGIMS, Lucknow, India
| |
Collapse
|
25
|
Abstract
A case of neurilemmoma arising from the olfactory groove presenting with headache, vomiting, and visual impairment in a thirty-seven-year-old man is reported. His clinical manifestations are described, with a brief review of three other cases reported in the literature so far.
Collapse
Affiliation(s)
- M Husain
- Neurosurgery Unit, K.G.'s Medical College, Lucknow, India
| | | | | | | |
Collapse
|
26
|
Affiliation(s)
- A Kumar
- Department of Renal Sciences and Neurology, Sanjay Gandhi Postgraduate Institute of Medicine Sciences, Lucknow, India
| | | | | | | | | | | |
Collapse
|
27
|
Abstract
Blood serum of twenty workers occupationally exposed to DDT for an average duration of 14 years was analysed for organochlorine pesticides by gas-liquid chromatography with an electron capture detector. Significant levels of BHC, p,p'-DDT, p,p'-DDD and p,p'-DDE were detected. A higher incidence of total DDT equivalent, about 10 times, was observed in DDT exposed workers when compared with a comparable sample of unexposed persons from the general population. Levels of DDT in serum of occupationally exposed workers were more than the permitted level of 200 ppb. The daily intake was computed to be about 10 mg/man/day as against 0.25 mg--the acceptable daily intake. Abnormal nerve conduction was encountered in a few cases of DDT sprayers. No significant correlation was observed between the total DDT equivalent in serum and duration of occupational exposure in workers. Levels of BHC in controls was 2.3 times the level in exposed workers, possibly due to induction of hepatic drug metabolising enzymes by high levels of DDT in the latter group. Findings are discussed in the light of existing knowledge of the bio-chemical effects evoked due to residual intoxication of DDT during occupational exposure.
Collapse
|