39 results on '"Dharmendra K. Singh"'
Search Results
2. Ultrasonic and Thermophysical Studies of Ethylene Glycol Nanofluids Containing Titania Nanoparticles and Their Heat Transfer Enhancements : Next-generation heat transfer nanofluids for industrial applications
- Author
-
Devraj Singh, Dharmendra K. Singh, Ashish Mathur, Shakti Pratap Singh, Aashit Kumar Jaiswal, R. R. Yadav, Mohit Gupta, and Shikha Wadhwa
- Subjects
Titania nanoparticles ,Materials science ,Process Chemistry and Technology ,Metals and Alloys ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,chemistry.chemical_compound ,Nanofluid ,Chemical engineering ,chemistry ,Heat transfer ,Electrochemistry ,Ultrasonic sensor ,0210 nano-technology ,Ethylene glycol - Abstract
In the present investigation, TiO2nanostructures were synthesisedviaa simple sol-gel technique and characterised with X-ray diffraction (XRD), scanning electron microscopy with energy-dispersive X-ray analysis (SEM-EDX), high-resolution transmission electron microscopy (HR-TEM) and ultraviolet-visible (UV-vis) spectroscopy. The temperature and concentration dependence of thermal conductivity enhancement (TCE) and ultrasonic velocity have been explored in ethylene glycol-based TiO2nanofluids. The obtained results showed 24% enhancement in thermal conductivity at higher temperature (80°C) of the base fluid ethylene glycol by adding 1.0 wt% of TiO2nanoparticles. The behaviour of TCE and ultrasonic velocity with temperature in prepared nanofluids has been explained with the help of existing phenomena. The increase in ultrasonic velocity in ethylene glycol with TiO2nanoparticles shows that a strong cohesive interaction force arises among the nanoparticles and base fluid. These results divulge that TiO2nanoparticles can be considered for applications in next-generation heat transfer in nanofluids.
- Published
- 2021
- Full Text
- View/download PDF
3. Design of Nanoscale Hybrid Insulator-Metal-Insulator Plasmonic Waveguide
- Author
-
Dharmendra K. Singh, Rakesh Ranjan, and Pintu Kumar
- Subjects
010302 applied physics ,Waveguide (electromagnetism) ,Materials science ,business.industry ,Physics::Optics ,Insulator (electricity) ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Electronic, Optical and Magnetic Materials ,Wavelength ,Dimension (vector space) ,Electric field ,0103 physical sciences ,Optoelectronics ,Surface plasmon resonance ,0210 nano-technology ,business ,Nanoscopic scale ,Intensity (heat transfer) - Abstract
Optical properties of the fundamental hybrid mode of hybrid insulator-metal-insulator plasmonic waveguide (HIMIPW), consists of insulator-metal-insulator sandwiched between two dielectric waveguides, have been investigated to achieve the relatively high propagation length and large normalized intensity at 1.55 µm working wavelength. The main aim of the current work is to settle the issues of high power loss and size of waveguide dimension. The optimum waveguide dimension of 0.2 µm × 0.02 µm has been obtained propagation length around 289.26 µm. The normalized intensity in the low-index region of the HIMIPW has been achieved around 67.50 , due to the electric field enhancement in this region. It is beneficial for the design of bio-sensing, optical manipulations, etc. The electric field intensity has been attained highest values at wavelength 1.55 µm for the optimum dimension of the HIMIPW ( = 0.2 µm, and ), due to highly localized surface plasmon resonance at the metal-dielectric interfaces. The investigation of the coupling length between the two identical parallel HIMIPWs with a separation distance has been done. Further to improve the coupling length, a metallic strip has been inserted between them, keeping the separation distance unchanged. The higher coupling length leads to lower crosstalk between two parallel hybrid plasmonic waveguides, which can be highly useful to achieve the larger integration over the photonic chip.
- Published
- 2021
- Full Text
- View/download PDF
4. Children, comorbidities and COVID-19 - What tilts the balance?
- Author
-
Ravi Shankar, Bhanu Kiran Bhakhri, Dharmendra K Singh, Vikas Jain, Sohini Ghosh, Nita Radhakrishnan, Devendra K Gupta, and Umesh Shukla
- Subjects
Pediatrics ,medicine.medical_specialty ,Respiratory distress ,business.industry ,Thalassemia ,lcsh:R ,lcsh:Medicine ,Hydroxychloroquine ,Disease ,comorbidities ,Single Center ,medicine.disease ,Azithromycin ,Asymptomatic ,covid-19 ,children ,medicine ,cancer ,Observational study ,medicine.symptom ,General Agricultural and Biological Sciences ,business ,medicine.drug - Abstract
Background: Data on the outcome of children with SARS-COV-2 infection (COVID-19) is still evolving as the pandemic unfolds Aims and Objective: The present study aims at describing the clinical severity, course and outcome of COVID-19 in children who had underlying illnesses or co-infections Materials and Methods: Retrospective, single center, observational study, conducted in a pediatric tertiary care center at Noida (National Capital Region, India) Results: We analyzed the data of 15 children with co-morbidities associated with COVID-19 Cancer (n=4, 26 6%), co-infections (n=5, 33 3%), Thalassemia major (n=2, 13 3%) and one child each with celiac disease, cholelithiasis, Duchenne muscular dystrophy and multiple rib fractures were diagnosed with COVID-19 None were asymptomatic 9 children (60%) had mild symptoms and 4 had moderate symptoms (26 6%) with respiratory distress 2 children had severe respiratory distress requiring high flow oxygen Convalescent plasma, IVIG, Oseltamivir, Azithromycin, Hydroxychloroquine were given as treatment in varying combinations All children recovered from COVID-19 Conclusion: Active malignancy, hypogammaglobinemia, underlying lung disease were associated with moderate to severe symptoms in this series of patients Convalescent plasma helped in both children with severe hypoxia [ABSTRACT FROM AUTHOR] Copyright of Asian Journal of Medical Sciences is the property of Manipal Colleges of Medical Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission However, users may print, download, or email articles for individual use This abstract may be abridged No warranty is given about the accuracy of the copy Users should refer to the original published version of the material for the full abstract (Copyright applies to all Abstracts )
- Published
- 2021
- Full Text
- View/download PDF
5. Use of convalescent plasma for managing severe COVID‐19 infection in 2‐month‐old infant
- Author
-
Devendra K Gupta, Seema Dua, Bhanu Kiran Bhakhri, Satyam Arora, Vikas Jain, Mukul R. Jain, Dharmendra K Singh, and Umesh Shukla
- Subjects
Pediatrics ,medicine.medical_specialty ,Convalescent plasma ,Apheresis ,Coronavirus disease 2019 (COVID-19) ,business.industry ,General Earth and Planetary Sciences ,Medicine ,Fresh frozen plasma ,business ,General Environmental Science - Published
- 2021
- Full Text
- View/download PDF
6. Optical performance of hybrid dielectric loaded plasmonic waveguide using PTFE for nano-scale light confinement
- Author
-
Dharmendra K. Singh, Rakesh Ranjan, and Pintu Kumar
- Subjects
Diffraction ,Waveguide (electromagnetism) ,Materials science ,business.industry ,Antenna aperture ,02 engineering and technology ,Dielectric ,Condensed Matter Physics ,Laser ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,law.invention ,010309 optics ,Wavelength ,020210 optoelectronics & photonics ,law ,0103 physical sciences ,0202 electrical engineering, electronic engineering, information engineering ,Power dividers and directional couplers ,Optoelectronics ,Electrical and Electronic Engineering ,Photonics ,business - Abstract
Different characteristics of fundamental mode of hybrid dielectric loaded plasmonic waveguide have been explored at 1 550 nm wavelength, to resolve the issue of large propagation loss and diffraction limit with minimal waveguide dimension. Propagation length of 432 um has been achieved with the optimal dimension of 200 nm×40 nm. Through the numerical simulation results, the effective area of 0.021 urn2 and normalized intensity of 40.71 µ−2 in the spacer region of the waveguide have been realized. To accomplish the ultra-compact directional coupler, the smaller coupling length of about 1.42 µm has been achieved. PTFE-based waveguide can be highly beneficial for the realization of monolithic integration with active optical devices.
- Published
- 2020
- Full Text
- View/download PDF
7. Methanol-Filled Hybrid Photonic Crystal Fiber with High Birefringent and Negative Dispersion
- Author
-
Sushi Sushanki Singh, Shahir Uddin, Dharmendra K. Singh, and M. A. Hassan
- Subjects
Physics ,chemistry.chemical_compound ,Birefringence ,chemistry ,Solid core ,Physics::Optics ,General Physics and Astronomy ,Hexagonal lattice ,Methanol ,Composite material ,Cladding (fiber optics) ,Effective refractive index ,Photonic-crystal fiber - Abstract
A unique hexagonal lattice structure of silica-based solid core photonic crystal fiber (PCF) surrounded by array of air holes is proposed. The cladding portion of the structure consists of five rings where core is made up of 11 small rings filled with methanol. Three different-shaped structures are used to analyze the effect on PCF parameters where the first structure uses circular air holes in cladding and core, the second structure consists of circular air holes in cladding and elliptical air holes in core, and the last structure was designed by using elliptical air holes in both cladding and core. Optical properties birefringence, confinement loss, and negative dispersion have been found theoretically and compared. A novel and relatively simple approach depicts the results that attain high birefringence, low confinement loss, and negative dispersion. It is found that the presence of elliptic air holes instead of circular air holes in the core region and the cladding brings higher birefringence, low confinement loss, and highly negative dispersion.
- Published
- 2020
- Full Text
- View/download PDF
8. Poly Lactic Acid, Poly Acrylic Acid and Ethanol Based Bio-Materials for PCF Design
- Author
-
M.Ashique Hassan, Dharmendra K. Singh, Shahiruddin, and Manisha Singh
- Subjects
Ethanol ,Materials science ,Mechanical Engineering ,Bio based ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Lactic acid ,010309 optics ,chemistry.chemical_compound ,chemistry ,Mechanics of Materials ,0103 physical sciences ,General Materials Science ,0210 nano-technology ,Effective refractive index ,Acrylic acid ,Nuclear chemistry - Abstract
Optical techniques have a momentous role in different Bio-sensing application, medical diagnosis and treatment. The availability of suitable Bio-materials such as poly lactic acid (PLA), poly acrylic acid (PAA) and ethanol has crucial impact on the designing of Photonic Crystal Fibre (PCF). The device performance and the bio-photonic applications are greatly affected by the different properties of optical, mechanical and biological and functionalities of these bio-materials. Bio-materials results in low optical loss due to its high clearness. It has moderately very less reflection, absorption and scattering of light. The different characteristics of PCF are analysed by using the different polymeric optical bio-materials. Waveguide properties have been numerically investigated by utilising the full vectorial finite element method (FEM). Dispersion at wide range of wavelength may be tuned by changing the structure geometry of bio-materials. Refractive index of Bio-materials influences the properties of Photonic Crystal fibre (PCF). A comparative result of proposed materials PCF characteristics shows highly negative dispersion, low confinement loss.
- Published
- 2020
- Full Text
- View/download PDF
9. Structural and Behavioural Analysis of As2Se3, TeO2, SiC, SiO2 and Si3N4 for Photonic Application
- Author
-
Dharmendra K. Singh, Anand Kumar, Shahiruddin, and M.Ashique Hassan
- Subjects
Materials science ,business.industry ,Mechanical Engineering ,Behavioural analysis ,Physics::Optics ,Polarization splitter ,02 engineering and technology ,Condensed Matter Physics ,01 natural sciences ,010309 optics ,020210 optoelectronics & photonics ,Mechanics of Materials ,0103 physical sciences ,Dispersion (optics) ,0202 electrical engineering, electronic engineering, information engineering ,Optoelectronics ,General Materials Science ,Photonics ,business - Abstract
The materials significantly influence the structural, optical and photoelectrical characteristic. Materials such as Arsenic selenide, Tellurite Glass, Silicon carbide, Silicon dioxide and Silicon nitride are investigated through finite element method. The models are established to analyse the structural behaviour of polarization preserving fibre of proposed materials. Photoelectric characteristic determines guided properties of photon particles. Refractive index of the materials influences the properties of photonic crystal fibre. A Polarization Splitter based hexagonal structure is proposed, where inner ring of cladding is in elliptical shape air holes and outer rings are in circular air holes. It provides highly negative dispersion, low confinement loss and high nonlinear coefficient between 1µm to 2µm wide wavelength ranges. The dispersion result shows -2000 db/km-nm at 1.55µm wavelength. Polarization beam splitters photonic crystal fiber characteristics of proposed materials are analysed with same structural parameters.
- Published
- 2020
- Full Text
- View/download PDF
10. Optical performance of hybrid metal‐insulator‐metal plasmonic waveguide for low‐loss and efficient photonic integration
- Author
-
Dharmendra K. Singh, Pintu Kumar, and Rakesh Ranjan
- Subjects
Crosstalk ,Materials science ,Plasmonic waveguide ,business.industry ,Optoelectronics ,Metal-insulator-metal ,Electrical and Electronic Engineering ,Photonics ,Condensed Matter Physics ,business ,Atomic and Molecular Physics, and Optics ,Plasmon ,Electronic, Optical and Magnetic Materials - Published
- 2020
- Full Text
- View/download PDF
11. Virus-Induced Gene Silencing in Sorghum Using Brome Mosaic Virus
- Author
-
Dharmendra K, Singh and Kirankumar S, Mysore
- Subjects
Humans ,Gene Silencing ,Edible Grain ,Bromovirus ,Software ,Sorghum - Abstract
Sorghum [Sorghum bicolor (L.) Moench.] is a versatile crop, grown in 30 countries and a food source for nearly 500 million people globally. Although the sorghum genome is sequenced, a limited understanding of gene function prevents the improvement of resistance against almost 150 species of viruses, bacteria, fungus, and parasitic plants to improve productivity. Here, we present a Brome mosaic virus (BMV)-based virus-induced gene silencing (VIGS) to silence target genes for functional study in sorghum. This protocol achieves 100% sorghum infection with BMV by growing the plants at 18 °C instead of 22 °C. Using this method, one can achieve gene silencing in sorghum up to 100% of the inoculated plants.
- Published
- 2022
12. Virus-Induced Gene Silencing in Sorghum Using Brome Mosaic Virus
- Author
-
Dharmendra K. Singh and Kirankumar S. Mysore
- Published
- 2022
- Full Text
- View/download PDF
13. Does Malaria Co-Infection Alter the Clinical Course in Children Infected with Dengue? Analysis from 623 Indian Children Admitted with Dengue Infection
- Author
-
Nupur Singh, Ruchi Rai, Dharmendra K Singh, and Bhanu Kiran Bhakhri
- Subjects
medicine.medical_specialty ,Blood transfusion ,Fever ,medicine.medical_treatment ,030231 tropical medicine ,Hepatosplenomegaly ,Serum albumin ,Dengue fever ,Dengue ,03 medical and health sciences ,0302 clinical medicine ,Antigen ,Internal medicine ,medicine ,Humans ,030212 general & internal medicine ,Child ,biology ,business.industry ,Coinfection ,medicine.disease ,Malaria ,Hospitalization ,Infectious Diseases ,Pediatrics, Perinatology and Child Health ,biology.protein ,Hemoglobin ,medicine.symptom ,business - Abstract
Background Dengue and malaria co-infection has been reported in several case reports. We aim to study effect of malaria co-infection on clinical outcomes of dengue infection. Methods Records of 623 children with dengue infection, based on NS-1 antigen and IgM ELISA testing, were collected. Malaria co-infection was identified in 20 cases, based on peripheral blood smear examination. Clinical and hematological parameters were compared in two groups (malaria co-infection vs. dengue mono-infection). Results Duration of hospitalization was significantly higher in co-infected group. Significantly higher proportion of malaria co-infection cases had hepatosplenomegaly, hemoglobin ≤8 g/dl, serum albumin ≤3 g/dl, serum bilirubin ≥1 mg/dl, serum aspartate aminotransferase ≥500 U/l and serum alanine aminotransferase ≥300 U/l. Number of transfusions (PRBC and platelets) required in malaria co-infection group was higher. Conclusion Malaria co-infection in dengue impacts clinical presentation, hematological parameters, requirement of blood transfusion and morbidity. High index of suspicion is warranted while evaluating febrile patients.
- Published
- 2021
14. Hirayama Disease
- Author
-
null Lakshay Diva, null Dharmendra K. Singh, MD, FRCR, and null Heena Rajani
- Published
- 2021
- Full Text
- View/download PDF
15. Analysis of supermode properties in three-core homogeneous strongly coupled multicore fiber
- Author
-
Rakesh Ranjan, Dharmendra K. Singh, and Umar Farooque
- Subjects
Physics ,Optical fiber ,Optical engineering ,Antenna aperture ,General Engineering ,02 engineering and technology ,Cladding (fiber optics) ,01 natural sciences ,Molecular physics ,Atomic and Molecular Physics, and Optics ,law.invention ,010309 optics ,020210 optoelectronics & photonics ,law ,Wavelength-division multiplexing ,Differential group delay ,0103 physical sciences ,Dispersion (optics) ,0202 electrical engineering, electronic engineering, information engineering ,Refractive index - Abstract
We have investigated the supermode properties, namely, mode effective refractive index (RI) (neff), effective area (Aeff), and chromatic dispersion (CD), in three-core homogeneous strongly coupled multicore fibers (SC-MCFs) for different core RI profiles (step index and RI dip) and in different possible core arrangements (triangular and linear). Further, the impacts of fiber parameters, namely, core radius (a), relative RI difference between core and cladding (Δ), and core pitch (Λ), on the differential group delay (DGD) between different supermodes have also been analyzed for all the considered configurations of SC-MCFs. The analysis presented has been done numerically using the FemSIM simulation platform. It has been observed that core arrangement has significant impact on the levels of neff, Aeff, CD, and DGD, and it also affects the degeneracy of the supermodes in a three-core homogeneous SC-MCF. Further, there exist certain core pitches in which the Aeff values of fundamental supermodes in different core layouts are equal. Furthermore, there exists a certain relative RI difference between the core and cladding (Δ) values in which DGD values in all the considered SC-MCF configurations are equal. On the other hand, over a range of Δ values, DGD in a linear layout is flattened compared to a triangular layout. Incorporating the RI dip structure in the cores of SC-MCFs affects the CD levels significantly. Therefore, by careful control of the fiber parameters and core arrangement, large mode effective area and low and flattened dispersion SC-MCF can be designed that may be suitable in dense wavelength division multiplexing application.
- Published
- 2020
- Full Text
- View/download PDF
16. Impact of Core Counts and Layouts on Dispersion Behavior in Homogeneous Multicore Fiber
- Author
-
Rakesh Ranjan, Dharmendra K. Singh, and Umar Farooque
- Subjects
Core (optical fiber) ,Materials science ,genetic structures ,Homogeneous ,Dispersion (optics) ,computer.software_genre ,Multicore fiber ,computer ,humanities ,psychological phenomena and processes ,Simulation software ,Computational physics - Abstract
Dispersion behaviors in homogeneous multicore fiber (MCF) with different core layouts and core counts have been investigated numerically using the FemSIM simulation software and MATLAB. It is noted that with the decrease in core pitch dispersion level decrease. The SLS core layout has the lowest value of dispersion compared to the other core layouts for a fixed core count. Core pitch in MCF decreases with the increase in core count in different core layouts and hence the level of dispersion decreases. However, the number of surrounding cores at different core pitch also affects the dispersion behavior. The investigations presented in the paper will help in low dispersion homogeneous MCF design.
- Published
- 2020
- Full Text
- View/download PDF
17. Two Sides Rhombus Shaped Cladding Hexagonal PCF with Low Confinement Loss and Negative Dispersion
- Author
-
Anand Kumar, M. A. Hassan, Shahir Uddin, and Dharmendra K. Singh
- Subjects
Mode field diameter ,Waveguide (electromagnetism) ,Materials science ,business.industry ,Antenna aperture ,Dispersion (optics) ,Optoelectronics ,Rhombus ,business ,Cladding (fiber optics) ,Finite element method ,Photonic-crystal fiber - Abstract
A novel design of solid core photonic crystal fiber (PCF) has been proposed with seven rings rhombus inside eight rings hexagonal structure. Waveguide properties have been numerically investigated by utilizing the full vectorial finite element method (FEM). Here the paper elaborates PCF characteristic like confinement loss, dispersion properties, normalize frequency, mode field diameter, effective area, and nonlinear coefficient with asymmetric cladding designed and investigated. Silica is used as background material. The calculated value shows the ultra-low confinement loss in 1.1 µm to 1.7 µm, low negative dispersion -400ps/km-nm achieved in solid core. The high nonlinear coefficient 3.1661762 W-1km-1 and 3.141089 W-1km-1 at 1.55 µm in xpolarization and y-polarization mode respectively achieved. PCF achieved low confinement loss and better mode field diameter for remote sensing application.
- Published
- 2020
- Full Text
- View/download PDF
18. Growth and physical properties of Bi2Sr2CaCu2O8+ crystals grown by a simple pressure technique and comparison with regrowth self-flux technique
- Author
-
Arya Mohan, A. Thamizhavel, Trupti S. Gaikwad, Dharmendra K. Singh, Neeraj K. Rajak, P. Manju, Amrutha Mukundan, and D. Jaiswal-Nagar
- Subjects
Diffraction ,Superconductivity ,Materials science ,Rietveld refinement ,Transition temperature ,Analytical chemistry ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Inorganic Chemistry ,Magnetization ,Impurity ,Phase (matter) ,0103 physical sciences ,Materials Chemistry ,010306 general physics ,0210 nano-technology ,Single crystal - Abstract
Single crystals of a high temperature superconductor Bi2Sr2CaCu2O8+x (2212) were grown using two different techniques, namely, regrowth technique as well as a pressure technique and the results are compared. Single crystal X-ray diffraction (XRD) performed on crystals grown using both techniques show no impurity or intergrowth phase. However, powder XRD reveals the presence of only Bi2Sr2CuO6+x(2201) intergrowth phase in crystals grown using pressure technique, with additional impurity phases also found in the crystals grown using regrowth technique. Rietveld refinement showed the weight fraction of 2212 as 93 % in crystals grown from pressure technique, confirming the excellent quality of the as-grown crystals. The transition temperature of crystals grown using both techniques was ∼ 90 K. It was found that pressure technique gives crystals that have a higher superconducting volume fraction ( ∼ 100) than that of crystals grown using regrowth technique. Structural and magnetization measurements reveal that the as-grown crystals grown using pressure technique are of high quality, comparable to those grown using traveling solvent floating zone technique. Crystals grown by both the techniques exhibit second magnetization peak anomaly.
- Published
- 2018
- Full Text
- View/download PDF
19. Epidemiological snapshot of carcinoma lung at a tertiary cancer centre of Bihar, India
- Author
-
A. K. Mandal, Dharmendra K. Singh, Manika Verma, Rakesh Ranjan, Amrita Rakesh, and Pritanjali Singh
- Subjects
Snapshot (photography) ,Oncology ,medicine.medical_specialty ,Lung ,medicine.anatomical_structure ,business.industry ,Internal medicine ,Cancer centre ,Epidemiology ,Carcinoma ,Medicine ,business ,medicine.disease - Abstract
Background: According to the GLOBOCAN 2020 report, the estimated incidence of lung cancer in India was 72,510 in all ages and both sexes. In incidence, lung cancer ranked fourth overall among the various types of cancer. To study epidemiological profile in terms of clinical presentation, stage, risk factors and factors associated with late stage presentations at a newly established tertiary cancer care hospital BiharMethods: This was a retrospective-prospective analysis of collected data of histopathologically proven lung cancer cases in the Outpatients department (OPD) of Department of Radiotherapy, All India Institute of Medical Sciences (AIIMS), Patna over a period of 2.5 years from March 2018 to October 2020.Results: There were 140 patients, with a median age of 56 years, 59.28% (n=83) were smokers, 37.14% (n=52) used chewing tobacco, 24.28% (n=34) worked on earthen stoves and 15% (n=21) had passive smoking exposure. The male-to-female ratio was 1.64:1. Non-small cell lung carcinoma comprised 87.85% (n=123), stage IV presentation in 76.42% (n=107) cases with the most common site of metastases being bone (35.51%, 38 patients). IHC was performed on 64 patients (45.71%) of total 140 patients of which 51 patients were of adenocarcinoma histology. 35.29% (n=18) were EGFR positive and 28.57% (n=4) tested ALK positive. 4 patients tested for ROS-1 were negative. 32.14% (n=45) cases were treated empirically for Tuberculosis on the finding of chest X-ray only.Conclusions: Majority of the patients were males in advanced stage. Bone is the most common site of metastases. Long empirical treatments lead to late presentations.
- Published
- 2021
- Full Text
- View/download PDF
20. Worst crosstalk analysis in heterogeneous and trench assisted heterogeneous multicore fiber for different core counts and layouts
- Author
-
Dharmendra K. Singh, Umar Farooque, and Rakesh Ranjan
- Subjects
Materials science ,Hexagonal crystal system ,Bend radius ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Multicore fiber ,Cladding (fiber optics) ,Topology ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,010309 optics ,Crosstalk ,0103 physical sciences ,Trench ,Electrical and Electronic Engineering ,0210 nano-technology ,Computer communication networks - Abstract
In order to obtain appreciably low worst crosstalk level in high core count multicore fiber, heterogeneous MCF with different core configurations and layouts have been investigated analytically using coupled mode equation. The variations in worst crosstalk behavior with respect to the bending radius, core configurations, core layouts, and outer cladding thickness have been analyzed. Further, the core count dependent variations in worst crosstalk level, core pitch, and peak bending radius in different core layouts have been presented. It has been observed that the selection of core configuration, core layout, and outer cladding thickness have significant impact on the reduction in worst crosstalk level. For example, in 12-core normal-index heterogeneous MCF with SLS structure, the core Configuration 1 can provide the worst crosstalk level reduced by 7.09 dB and 16.92 dB in comparison to the other two core configurations, i.e., Configuration 2, and Configuration 3, respectively. Further, for the same core count with TA Configuration 1, SLS core layout can achieve the reduced worst crosstalk level in comparison with circular ORS and DRS, hexagonal ORS and DRS respectively by 24.62 dB, 25.86 dB, 28.87 dB and 30.64 dB.
- Published
- 2019
- Full Text
- View/download PDF
21. Dispersion Behavior of Fundamental Supermodes in Homogeneous Strongly Coupled Multicore Optical Fibers for Different Core Counts and Layouts
- Author
-
Dharmendra K. Singh, Umar Farooque, and Rakesh Ranjan
- Subjects
Physics ,Optical fiber ,Geometry ,02 engineering and technology ,01 natural sciences ,Square lattice ,Square (algebra) ,Finite element method ,law.invention ,010309 optics ,Core (optical fiber) ,020210 optoelectronics & photonics ,law ,Electric field ,0103 physical sciences ,Dispersion (optics) ,0202 electrical engineering, electronic engineering, information engineering ,Refractive index - Abstract
In this paper, dispersion behavior of fundamental supermode in homogeneous strongly-coupled multicore fibers (SC-MCFs) have been investigated using the finite element method based simulation platform and MATLAB. Further, to observe the impacts of core count and core layout on the dispersion behavior of fundamental supermode, the core count and layout dependent dispersion behavior have been investigated. The different core layouts considered are namely, linear, triangular, square, rectangular, square lattice structure (SLS), circular and hexagonal one ring structure (ORS) and circular dual ring structure (DRS), while the different core counts are 3-Core, 4-Core, 6-Core, and 12-Core. It has been observed that the core layouts of homogeneous SC-MCFs with the closely packed structures for the different core counts have the lowest value of $\left\vert D(\lambda)\right\vert_{\max}$ (magnitude of maximum dispersion), as compared to the other layouts. Moreover, it has been observed that in some of the core layouts, such as 4-Core square, 6-Core circular, and 12-Core circular DRS, the dispersion behaviors are nearly flat over a certain wavelength range, which is desirable for the high speed DWDM applications. Therefore, the analysis presented in this paper may be useful for the selection of core layouts in homogeneous SC-MCF with significantly low dispersion level or the flattened dispersion behavior.
- Published
- 2019
- Full Text
- View/download PDF
22. A solid silica core based non-linear hybrid PCF with low confinement loss
- Author
-
Shahir Uddin and Dharmendra K. Singh
- Subjects
Materials science ,genetic structures ,Hexagonal crystal system ,Wavelength range ,business.industry ,Physics::Optics ,E band ,02 engineering and technology ,Cladding (fiber optics) ,01 natural sciences ,Molecular physics ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,Photonic crystal fibre ,010309 optics ,Nonlinear system ,Wavelength ,020210 optoelectronics & photonics ,Optics ,0103 physical sciences ,0202 electrical engineering, electronic engineering, information engineering ,Electrical and Electronic Engineering ,business ,Dispersion compensation - Abstract
This paper aims to analyze solid silica core based Photonic Crystal Fibre (PCF). The proposed structures consists of three inner layers of hexagonal shaped air holes and four outer layers of circular shaped holes and compare it with oval shaped structure. The broadband dispersion compensation and confinement loss covering the O, E, S, C and L bands and observed zero and negative dispersion in O and E band also very low confinement loss in all bands. The diameter of air holes is varied to generate flattened dispersion characteristics for the hybrid cladding PCF structure. Our purpose is to attain high non-linearity along with low confinement loss of two layered photonic crystal fibre for different air fill fraction d/Λ (0.65–0.95) values. Also, it is shown that the non-linear coefficient magnifies with the decreasing wavelength in PCF and the confinement losses are less than 0.001 dB/km in the O-E-S-C-L wavelength range from (1.2 to 1.6) μm.
- Published
- 2016
- Full Text
- View/download PDF
23. Mode Analysis of Hybrid Metal-Insulator-Metal Multilayer Plasmonic Waveguide
- Author
-
Rakesh Ranjan, Pintu Kumar, and Dharmendra K. Singh
- Subjects
010302 applied physics ,Multi-mode optical fiber ,Materials science ,Silicon ,business.industry ,Mode (statistics) ,Physics::Optics ,chemistry.chemical_element ,02 engineering and technology ,Metal-insulator-metal ,Dielectric ,021001 nanoscience & nanotechnology ,01 natural sciences ,Waveguide (optics) ,Wavelength ,chemistry ,0103 physical sciences ,Optoelectronics ,0210 nano-technology ,business ,Plasmon - Abstract
In order to explore the mode properties, such as effective mode index and propagation length of the hybrid metal-insulator-metal (HMIM) multilayer Plasmonic waveguide, the dimensions of the waveguide have been varied at the operating wavelength of 1550 nm under the constraint of light propagation through the low-index region. The mode analysis for the propagation of fundamental and higher order modes have been carried out in the current work to obtain the suitable dimension of the HMIM Plasmonic waveguide. The multimode propagation is an important aspect for the bio-sensor related applications.
- Published
- 2018
- Full Text
- View/download PDF
24. Dispersion over all telecommunication bands with hexagonal photonic crystal fiber
- Author
-
Dharmendra K. Singh, Shahiruddin, M. A. Hassan, and Shahli Tabassum
- Subjects
Materials science ,Hexagonal crystal system ,business.industry ,Ranging ,02 engineering and technology ,Cladding (fiber optics) ,Wavelength ,020210 optoelectronics & photonics ,Liquid crystal ,0202 electrical engineering, electronic engineering, information engineering ,Telecommunications ,business ,Refractive index ,Photonic-crystal fiber - Abstract
The proposed design shows zero dispersion over all telecommunication bands (O to L) i.e., ranging from 1260nm to 1625 nm. The light is well confined in the center of the core of the proposed PCF at all telecommunication bands with a very low confinement loss in the order of 10−7. The proposed design has a core filled with a nematic liquid crystal (E7) that is highly flexibility with temperature. The effect of structure geometry and dispersion are investigated using hexagonal structure. The numerical result reveals that the design has negative dispersion at λ=2μm and zero dispersion from O-band to L-band. As the diameter of air hole in cladding increases, the dispersion changes upto −150ps/nm.km at wavelength 1μm. The proposed structure can be used in telecommunication and as a temperature sensor.
- Published
- 2018
- Full Text
- View/download PDF
25. Transmission Properties of Lower Refractive Index Liquid Filled Hexagon Solid Core PCF
- Author
-
Dharmendra K. Singh, M. A. Hassan, Shalini, and Shahiruddin
- Subjects
Optics ,Birefringence ,Materials science ,Fabrication ,Normalized frequency (fiber optics) ,business.industry ,Antenna aperture ,Solid core ,Physics::Optics ,business ,Polarization (waves) ,Refractive index ,Photonic crystal - Abstract
Lower refractive index liquid filled hexagon solid core PCF geometry is demonstrated. The optical characteristics of designed fiber can be modified by varying the geometrical parameters such as air hole diameter and keeping the pitch constant. It has been observed that low confinement loss along X and Y polarization, high birefringence, nearly zero dispersion, effective area of 42.18 µm2 at 1.55 µm simultaneously achieved by using the commercial Rsoft software. The other optical properties such as effective refractive index, normalized frequency and nonlinear coefficient are also evaluated. With all these good features the designed model has potential applications in heat sensing and food quality control. But among the various advantages of the proposed PCF the most important is its simplified fabrication procedure.
- Published
- 2018
- Full Text
- View/download PDF
26. Design and Analysis of Rhombus-Shaped Dual-Core Propylene Glycol Filled PCF
- Author
-
Dharmendra K. Singh, M. A. Hassan, Shahiruddin, and Neha Kumari
- Subjects
Transmission properties ,chemistry.chemical_compound ,Materials science ,Birefringence ,chemistry ,Antenna aperture ,Dispersion (optics) ,Rhombus ,Composite material ,Polarization (waves) ,Polyvinyl alcohol ,Dual core - Abstract
A novel form of rhombus solid dual-core PCFs structures filled with propylene glycol for different air hole diameter is presented. The proposed fiber contains seven circular air holes. Using Rsoft FEMSIM software, the transmission properties such as confinement loss, effective mode area, chromatic dispersion, birefringence, nonlinearity, and Veff are analyzed. The proposed structure shows the high birefringence of 1.07 × 10−4, low confinement loss along X polarization is 1.8606 × 10−4 and along Y polarization is 1.5095 × 10−4 dB/m, large negative dispersion, effective area of 27.66 µm2 at 1.55 µm. Proposed fiber has ultimate performance, and it is uncomplicated and easy to fabricate.
- Published
- 2018
- Full Text
- View/download PDF
27. Mach–Zehnder Interferometer-Based 3-Bit All-Optical Sequence Detector
- Author
-
Abhishek Ranjan, Rakesh Ranjan, and Dharmendra K. Singh
- Subjects
chemistry.chemical_compound ,Sequential logic ,Electro-optic effect ,chemistry ,Computer science ,Detector ,Lithium niobate ,Astronomical interferometer ,Electronic engineering ,Physics::Optics ,Mach–Zehnder interferometer ,Bitstream ,Optical switch - Abstract
All-optical devices can support high data rate in a communication system compared with its electronic counterparts. Several all-optical logic devices can be implemented using Mach–Zehnder interferometers (MZIs). The MZI structure uses electro-optic effect to switch light across the titanium-diffused lithium niobate optical waveguide from cross-state to bar-state and vice versa. Sequence detector is a significant sequential circuit that detects the presence of predefined bit sequence in the input bit stream. The paper presents an all-optical 3-bit sequence detector that detects the bit sequence 110 from the main bit stream. The operations of the proposed device are analysed and verified using OptiBPM software. This all-optical device could be deployed in several optical switching and networking operations.
- Published
- 2018
- Full Text
- View/download PDF
28. Analysis of single polarization single mode photonic crystal cladding with hexagonal and rectangular lattice
- Author
-
Shahiruddin, Dharmendra K. Singh, and Naman Agarwal
- Subjects
Birefringence ,Materials science ,business.industry ,Single-mode optical fiber ,Physics::Optics ,Cladding (fiber optics) ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,Optics ,Lattice (order) ,Hexagonal lattice ,Electrical and Electronic Engineering ,business ,Anisotropy ,Photonic crystal ,Photonic-crystal fiber - Abstract
Single-polarization single-mode (SPSM) operation of highly birefringent (HB) photonic crystal fibers (PCF) with rectangular and hexagonal lattice is investigated in detail by using a full-vector finite-element method (FEM) with anisotropic perfectly matched layers (PMLs). The position of the region of single polarization can be tuned freely by adjusting the size of the central enlarged air holes. The confinement loss and dispersion losses for standard single-mode fiber for particular SPSM PCFs are calculated and optimized. The proposed fibers are nonlinear SPSM, which may be useful for nonlinear optical applications or applications with a wide SPSM operating bandwidth requirement.
- Published
- 2015
- Full Text
- View/download PDF
29. Single Mode Negative Dispersion Hexagonal Photonic Crystal Fiber
- Author
-
Akash Kumar, Shahiruddin, and Dharmendra K. Singh
- Subjects
Materials science ,Hexagonal crystal system ,business.industry ,Wavelength range ,Single-mode optical fiber ,Physics::Optics ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,010309 optics ,Wavelength ,0103 physical sciences ,Dispersion (optics) ,Solid core ,Optoelectronics ,0210 nano-technology ,business ,Photonic-crystal fiber - Abstract
A photonic crystal fiber (PCF) with circular air holes having low dispersion and low confinement loss is analyzed. By deliberate selection of dimensions of air holes and spacing between air holes, it is possible to obtain the two required properties of solid core PCF at wide wavelength range that is negative dispersion and low confinement loss which is of the order of 10−7 dB/m. At 1.55 µm wavelength with common pitch (Λ), the simulated results have been observed at different diameters. The intended design finds applications in communication fields.
- Published
- 2017
- Full Text
- View/download PDF
30. Highly Negative Dispersive, Low Loss Single-Mode Photonic Crystal Fiber
- Author
-
Sneha Singh, Dharmendra K. Singh, and Shahiruddin
- Subjects
Wavelength ,Range (particle radiation) ,Materials science ,business.industry ,Dispersion (optics) ,Optical communication ,Single-mode optical fiber ,Physics::Optics ,Optoelectronics ,Fiber ,Microstructured optical fiber ,business ,Photonic-crystal fiber - Abstract
In this paper a new five-layer circular air holes photonic crystal fiber (PCF) having low dispersion and confinement loss is analyzed. A full-vector finite-element method approach is used . Due to proper selection of air-fill fraction, it has been made possible to obtain the two required properties of PCF for wide range of wavelengths, that is, low (nearly zero and high negative) dispersion and ultralow confinement loss of the order of 10−7 dB/km. It has been found that the proposed fiber is single mode. The confinement loss and dispersion is demonstrated for wavelength range which are 1–2 µm. Thus highly negative dispersion of PCFs useful for application in optical communication links as dispersion compensating fibers.
- Published
- 2017
- Full Text
- View/download PDF
31. The Tomato Kinome and the Tomato Kinase Library ORFeome: Novel Resources for the Study of Kinases and Signal Transduction in Tomato and Solanaceae Species
- Author
-
Daisuke Shibata, Dharmendra K. Singh, Elizabeth K. Brauer, Johannes W. Stratmann, Mauricio Calviño, Sorina C. Popescu, Hideyuki Suzuki, Koh Aoki, Susan R. Strickler, Noe Fernandez-Pozo, Roopa Yalamanchili, George V. Popescu, and Lukas A. Mueller
- Subjects
Physiology ,Protein Array Analysis ,Pseudomonas syringae ,Computational biology ,Open Reading Frames ,Bacterial Proteins ,Solanum lycopersicum ,Plant Immunity ,Genomic library ,Kinome ,Luciferases ,ORFeome ,Solanaceae ,Gene Library ,Plant Diseases ,Plant Proteins ,biology ,Effector ,Kinase ,business.industry ,Protoplasts ,Genetic Complementation Test ,fungi ,Computational Biology ,food and beverages ,General Medicine ,biology.organism_classification ,Biotechnology ,Host-Pathogen Interactions ,Solanum ,Signal transduction ,business ,Protein Kinases ,Agronomy and Crop Science ,Signal Transduction - Abstract
Protein kinase–driven phosphorylation constitutes the core of cellular signaling. Kinase components of signal transduction pathways are often targeted for inactivation by pathogens. The study of kinases and immune signal transduction in the model crop tomato (Solanum lycopersicum) would benefit from the availability of community-wide resources for large scale and systems-level experimentation. Here, we defined the tomato kinome and performed a comprehensive comparative analysis of the tomato kinome and 15 other plant species. We constructed a tomato kinase library (TOKN 1.0) of over 300 full-length open reading frames (ORF) cloned into a recombination-based vector. We developed a high-throughput pipeline to isolate and transform tomato protoplasts. A subset of the TOKN 1.0 library kinases were expressed in planta, were purified, and were used to generate a functional tomato protein microarray. All resources created were utilized to test known and novel associations between tomato kinases and Pseudomonas syringae DC3000 effectors in a large-scale format. Bsk7 was identified as a component of the plant immune response and a candidate effector target. These resources will enable comprehensive investigations of signaling pathways and host-pathogen interactions in tomato and other Solanaceae spp.
- Published
- 2014
- Full Text
- View/download PDF
32. Immunogenicity of Hepatitis B Vaccine in HIV Exposed Uninfected Infants
- Author
-
Rajnish Kumar, Anudita Bhargava, Ruchi Rai, Manisha Maurya, and Dharmendra K Singh
- Subjects
0301 basic medicine ,Hepatitis B vaccine ,Statistics as Topic ,Human immunodeficiency virus (HIV) ,India ,HIV Infections ,Adaptive Immunity ,medicine.disease_cause ,03 medical and health sciences ,Pregnancy ,HIV Seronegativity ,medicine ,Humans ,Hepatitis B Vaccines ,Prospective Studies ,Pregnancy Complications, Infectious ,Prospective cohort study ,business.industry ,Immunogenicity ,Infant ,Hepatitis B ,medicine.disease ,Acquired immune system ,Virology ,030104 developmental biology ,Pediatrics, Perinatology and Child Health ,Immunology ,Female ,business - Abstract
There is paucity of knowledge about the immunogenicity of vaccines in infants who have been exposed to HIV in-utero but have remained uninfected. The authors studied the immunogenicity of 3 doses of recombinant hepatitis B vaccine at 6,10,14 wk of age in HIV exposed but uninfected (HEU) infants. After 3 mo of last dose of the vaccine, out of 26 infants, 23 (89.5 %) infants were found to be responders (Anti HBs IgG titres ≥ 10 mIU/ml) and 3 (11.5 %) babies remained non responders (Anti HBs IgG titres < 10 mIU/ml). The proportion of babies who were non responders were higher when compared to similar studies done on unexposed and uninfected infants, suggesting a poorer immunogenicity of hepatitis B vaccine in these infants.
- Published
- 2015
- Full Text
- View/download PDF
33. Fibrillin protein function: the tip of the iceberg?
- Author
-
Timothy W. McNellis and Dharmendra K. Singh
- Subjects
musculoskeletal diseases ,Plastoglobule ,Microfilament Proteins ,fungi ,Gene Expression ,food and beverages ,Fibrillins ,macromolecular substances ,Plant Science ,Biology ,Adaptation, Physiological ,Cell biology ,Chloroplast ,Thylakoid ,Chromoplast ,Pigment accumulation ,Plastids ,Photosynthesis ,Plastid ,Fibrillin ,Phylogeny ,Plant Proteins - Abstract
Fibrillins are nuclear-encoded, plastid proteins associated with chromoplast fibrils and chloroplast plastoglobules, thylakoids, photosynthetic antenna complexes, and stroma. There are 12 sub-families of fibrillins. However, only three of these sub-families have been characterized genetically or functionally. We review evidence indicating that fibrillins are involved in plastoglobule structural development, chromoplast pigment accumulation, hormonal responses, protection of the photosynthetic apparatus from photodamage, and plant resistance to a range of biotic and abiotic stresses. The area of fibrillin research has substantial growth potential and will contribute to better understanding of mechanisms of plant stress tolerance and plastid structure and function.
- Published
- 2011
- Full Text
- View/download PDF
34. Comparative Analysis of Hexagonal Solid Silica and Nitro-benzene Filled Hollow Core Photonic Crystal Fiber
- Author
-
M. A. Hassan, Dharmendra K. Singh, and Shahiruddin
- Subjects
Hollow core ,chemistry.chemical_compound ,Materials science ,chemistry ,Chemical engineering ,Hexagonal crystal system ,Nitro ,Benzene ,Photonic-crystal fiber - Published
- 2018
- Full Text
- View/download PDF
35. Design and characteristics of negative dispersion of two layered five ring photonic crystal fiber
- Author
-
Dharmendra K. Singh, Priya Jayaswal, Richa Khaklari, Vithika Singh, and Shahiruddin
- Subjects
All-silica fiber ,Mode volume ,Double-clad fiber ,Materials science ,Zero-dispersion wavelength ,Physics::Optics ,Dispersion-shifted fiber ,Composite material ,Cladding (fiber optics) ,Graded-index fiber ,Photonic-crystal fiber - Abstract
A numerical finite element method (FEM) based analysis of mode profile, dispersion characteristics and birefringence of two layered five rings photonic crystal fiber for different air fill fraction d/Λ (0.6–0.9) is proposed. The proposed structure consists of two inner hexagonal layers and outer three circular layers. The inner hexagonal layers consist of air holes each of diameter d 1 . Two circular layers surrounding the hexagonal layers have air holes of diameter d 2 while the outer most circular layer has air holes of diameter d 3 . The proposed structure is shown to possess an optimum mode profile. The effective refractive index of the cladding depends on the air-fill fraction of the fiber. Refractive index decreases with increasing air-fill fraction for the same wavelength. It is shown that the negative dispersion coefficient can be controlled by the pitch Λ and the diameter of air holes. Also shown is the linear relation of Birefringence with bit rate. The corresponding graphs of all the parameters are evaluated and plotted. The proposed structure is simulated using the commercial Rsoft software.
- Published
- 2015
- Full Text
- View/download PDF
36. Novel Numerical Method to Model Multichannel Erbium-Doped Fiber Amplifier
- Author
-
Dharmendra K. Singh, Vishnu Priye, and Subhash C. Arya
- Subjects
Physics ,Optical amplifier ,Amplified spontaneous emission ,Optimization problem ,Optical fiber ,Iterative method ,Numerical analysis ,Evolutionary algorithm ,Physics::Optics ,Topology ,Atomic and Molecular Physics, and Optics ,Electronic, Optical and Magnetic Materials ,law.invention ,law ,Genetic algorithm ,Electronic engineering - Abstract
We propose a novel numerical method based on genetic algorithm (GA) to solve the evolution equations that are the basis of modeling multichannel erbium-doped fiber amplifiers (EDFAs). The evolution equations are first transformed from an iteration problem to an optimization problem. The unknown parameter related to backward amplified spontaneous emission (BASE) is coded into a string of bits based on their probable lower and upper limits. By defining proper random variation operators and cost function, the coupled evolution equations are optimized using GA for different values of erbium-doped fiber parameters. It is observed that GA is an efficient method for analyzing the EDFA characteristics in the entire C-band.
- Published
- 2006
- Full Text
- View/download PDF
37. Nutritional Rehabilitation of Children < 6 mo with Severe Acute Malnutrition
- Author
-
Ruchi Rai, Anubha Srivastava, Prakash Chandra Mishra, Manisha Maurya, and Dharmendra K Singh
- Subjects
Pediatrics ,medicine.medical_specialty ,business.industry ,Severe Acute Malnutrition ,Infant ,Weight Gain ,Infant Nutrition Disorders ,Teaching hospital ,Non responders ,Acute Disease ,Pediatrics, Perinatology and Child Health ,medicine ,Humans ,medicine.symptom ,business ,Nutritional rehabilitation ,Weight gain ,Breast feeding ,Acute diarrhoea - Abstract
The authors studied the outcome of 108 infants
- Published
- 2013
- Full Text
- View/download PDF
38. FIBRILLIN4 is required for plastoglobule development and stress resistance in apple and Arabidopsis
- Author
-
Philip J. Jensen, Henry K. Ngugi, Dharmendra K. Singh, Brian L. Lehman, Siela N. Maximova, and Timothy W. McNellis
- Subjects
Paraquat ,Malus ,Chloroplasts ,Light ,Physiology ,Plastoglobule ,Arabidopsis ,Pseudomonas syringae ,Plant Science ,Environmental Stress and Adaptation to Stress ,Ozone ,Gene Expression Regulation, Plant ,Stress, Physiological ,Botany ,Genetics ,Erwinia amylovora ,Arabidopsis thaliana ,Photosynthesis ,Plant Diseases ,Plant Proteins ,biology ,Wild type ,biology.organism_classification ,Chloroplast ,Light intensity ,Biochemistry ,RNA, Plant ,Gene Knockdown Techniques ,RNA Interference - Abstract
The fibrillins are a large family of chloroplast proteins that have been linked with stress tolerance and disease resistance. FIBRILLIN4 (FIB4) is found associated with the photosystem II light-harvesting complex, thylakoids, and plastoglobules, which are chloroplast compartments rich in lipophilic antioxidants. For this study, FIB4 expression was knocked down in apple (Malus 3 domestica) using RNA interference. Plastoglobule osmiophilicity was decreased in fib4 knockdown (fib4 KD) tree chloroplasts compared with the wild type, while total plastoglobule number was unchanged. Compared with the wild type, net photosynthetic CO2 fixation in fib4 KD trees was decreased at high light intensity but was increased at low light intensity. Furthermore, fib4 KD trees produced more anthocyanins than the wild type when transferred from low to high light intensity, indicating greater sensitivity to high light stress. Relative to the wild type, fib4 KD apples were more sensitive to methyl viologen and had higher superoxide levels during methyl viologen treatment. Arabidopsis (Arabidopsis thaliana) fib4 mutants and fib4 KD apples were more susceptible than their wild-type counterparts to the bacterial pathogens Pseudomonas syringae pathovar tomato and Erwinia amylovora, respectively, and were more sensitive to ozone-induced tissue damage. Following ozone stress, plastoglobule osmiophilicity decreased in wild-type apple and remained low in fib4 KD trees; total plastoglobule number increased in fib4 KD apples but not in the wild type. These results indicate that FIB4 is required for plastoglobule development and resistance to multiple stresses. This study suggests that FIB4 is involved in regulating plastoglobule content and that defective regulation of plastoglobule content leads to broad stress sensitivity and altered photosynthetic activity.
- Published
- 2010
39. Length of postnatal stay in healthy newborns and re-hospitalization following their early discharge
- Author
-
Tarun Dua, Dharmendra K Singh, Shivali Malhotra, and Piyush Gupta
- Subjects
Pediatrics ,medicine.medical_specialty ,Time Factors ,Birth weight ,Population ,India ,Patient Readmission ,medicine ,Childbirth ,Humans ,Prospective Studies ,Prospective cohort study ,education ,Early discharge ,education.field_of_study ,Pregnancy ,business.industry ,Infant, Newborn ,Jaundice ,Length of Stay ,medicine.disease ,Patient Discharge ,Low birth weight ,Perinatal Care ,Pediatrics, Perinatology and Child Health ,medicine.symptom ,business - Abstract
The present study was conducted prospectively to determine i) the length of postnatal hospital stay of healthy newborns and determine the factors facilitating their early discharge (48 h) and ii) the frequency and causes of re-hospitalization following early discharge, in a tertiary care hospital.Length of hospital stay was recorded for healthy newborns. Factors facilitating Early discharge were determined by both univariate and multivariate (multiple logistic regression) analyses. Of all newborns discharged within 48 h, every third case was called for a follow-up visit 72 hrs later and examined for any medical problem and need of re-hospitalization.A total of 1134 babies were enrolled, of which 861 (76.2%) were discharged at or before 48 hours. The overall mean (SD) length of hospital stay was 46.4 (45.8) h. Factors contributing to early discharge included vaginal delivery (RR: 30.2; 95% CI: 19.0, 47.9; P0.001), absence of pre-existing maternal disease or obstetric complication (RR: 4.32; 95% CI: 2.27, 8.22; P0.001), and birth weight of2.5 kg (RR: 1.91; 95% CI: 1.27, 2.89; P = 0.002). Of the 280 neonates called for follow-up, 193 reported. Of these, 61 (31.6%) were normal. Neonatal jaundice was the most frequent problem seen in 105 (54.4%) children on follow-up. Only 16 (8.3%) newborns needed re-hospitalization; the most common indication being neonatal jaundice (n=9).Most of the children in our set-up are being discharged within 48 hrs. Early discharge is governed primarily by maternal indications. A follow-up visit after 72 hr is important to assess the need of re-hospitalization in healthy newborns discharged within 48 hrs of birth.
- Published
- 2006
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.