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MXenes and heterostructures-based electrocatalysts for hydrogen evolution reaction:Recent developments and future outlook

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Journal of Energy Chemistry 2024年第5期92卷 176-206页

作者： Abdul Hanan Hafiz Taimoor Ahmed Awan Faiza Bibi Raja Rafidah Raja Sulaiman Wai Yin Wong Rashmi Walvekar seema Singh Mohammad Khalid Sunway Centre for Electrochemical Energy and Sustainable Technology(SCEEST) School of Engineering and TechnologySunway UniversityNo.5 Jalan UniversitiBandar Sunway47500 Petaling JayaSelangorMalaysia Fuel Cell Institute Universiti Kebangsaan Malaysia43600 UKM BangiSelangorMalaysia Faculty of Innovation and Technology School of EngineeringChemical Engineering ProgrammeNo.1 Jalan Taylor’sTaylor’s University Malaysia47500 Subang JayaSelangorMalaysia Chitkara Centre for Research and Development Chitkara UniversityHimachal Pradesh 174103India School of Applied and Life Sciences Uttaranchal UniversityDehradunUttarakhand 248007India Manipal Institute of Technology Manipal Academy of Higher EducationManipal 576104KarnatakaIndia Centre of Research Impact and Outcome Chitkara UniversityPunjab 140401India

The increasing focus on electrocatalysis for sustainable hydrogen(H_(2))production has prompted significant interest in MXenes,a class of two-dimensional(2D)materials comprising metal carbides,carbonitrides,and *** materials exhibit intriguing chemical and physical properties,including excellent electrical conductivity and a large surface area,making them attractive candidates for the hydrogen evolution reaction(HER).This scientific review explores recent advancements in MXene-based electrocatalysts for HER *** discusses various compositions,functionalities,and explicit design principles while providing a comprehensive overview of synthesis methods,exceptional properties,and electro-catalytic approaches for H_(2) production via electrochemical ***,challenges and future prospects in designing MXenes-based electrocatalysts with enhanced kinetics are highlighted,emphasizing the potential of incorporating different metals to expand the scope of electrochemical *** review suggests possible efforts for developing advanced MXenes-based electrocatalysts,particularly for efficient H_(2) generation through electrochemical water-splitting reactions..

关键词： MXenes Electrocatalyst Water Splitting Hydrogen Generation Clean Energy

Role of iron deficiency anemia in inflammatory bowel disease

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World Journal of Clinical Pediatrics 2024年第3期13卷 1-3页

作者： seema Rai Department of Pediatrics Guru Gobind Singh Medical College&HospitalFaridkot 151203PunjabIndia

Inflammatory bowel disease(IBD)is a relapsing chronic inflammatory disorder of the small and large gut with rising incidence and prevalence *** deficiency anemia is one of the most common extraintestinal manifestations of IBD,which correlates with the disease activity and tendency to relapse even after successful *** affects various aspects of quality of life,such as physical,cognitive,emotional,and workability,as well as healthcare *** anemia in IBD can be due to iron deficiency(ID)or chronic *** relative frequency of ID in IBD is 60%,according to some studies,and only 14%receive *** evaluation of ID is also tricky as ferritin,being an inflammatory marker,also rises in chronic inflammatory diseases like *** review of anemia in IBD patients involves other investigations like transferrin saturation and exploration of other nutritional deficiencies to curb the marker asthenia with which these patients often *** underscores the importance of timely investigation and treatment to prevent long-term *** can start oral iron therapy in certain ***,as inflammation of the gut hampers iron absorption,an alternative route to bypass the inflamed gut is usually recommended to avoid the requirement for blood transfusions.

关键词： Colitis Iron deficiency Anemia Inflammation Ferritin

Heterogeneous tunable Ⅲ-Ⅴ-on-silicon-nitride mode-locked laser emitting wide optical spectra

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Photonics Research 2024年第3期12卷 I0021-I0027页

作者： MAXIMILIEN BILLET STIJN CUYVERS STIJN POELMAN ARTUR HERMANS SANDEEP seema SASEENDRA TASUKU NAKAMURA SHINYA OKAMOTO YASUHISA INADA KAZUYA HISADA TAKU HIRASAWA JOAN RAMIREZ DELPHINE NÉEL NICOLAS VAISSIÈRE JEAN DECOBERT PHILIPPE SOUSSAN XAVIER ROTTENBERG GUNTHER ROELKENS JONØ.KJELLMAN BART KUYKEN Photonics Research Group Department of Information TechnologyGhent University-imec9052 GhentBelgium imec 3001 LeuvenBelgium Technology Division Panasonic Holdings CorporationMoriguchi-CityOsakaJapan Ⅲ-Ⅴ Lab F91767 PalaiseauFrance

We demonstrate a Ⅲ-Ⅴ-on-silicon-nitride mode-locked laser through the heterogeneous integration of a semiconductor optical amplifier on a passive silicon-nitride cavity using the technique of micro-transfer printing. In the initial phase of our study, we focus on optimizing the lasing wavelength to be centered at 1550 nm. This optimization is achieved by conducting experiments with 27 mode-locked lasers, each incorporating optical amplifiers featuring distinct multiple-quantum-well photoluminescence values. Subsequently we present a comprehensive study investigating the behavior of the mode-locking regime when the electrical driving parameters are varied. Specifically, we explore the impact of the gain voltage and saturable absorber current on the locking stability of a tunable mode-locked laser. By manipulating these parameters, we demonstrate the precise control of the optical spectrum across a wide range of wavelengths spanning from 1530 to 1580 nm. Furthermore, we implement an optimization approach based on a Monte Carlo analysis aimed at enhancing the mode overlap within the gain region. This adjustment enables the achievement of a laser emitting a 23-nm-wide spectrum while maintaining a defined 10 dB bandwidth for a pulse repetition rate of 3 GHz.

关键词： tunable amplifier mode

Bianchi Type-V Bulk Viscous Barotropic Fluid Cosmological Model with Variable G and A

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Chinese Physics Letters 2008年第8期25卷 3090-3093页

作者： Raj Bali seema Tinker Department of Mathematics University of Rajasthan 3aipur-302004 India

We investigate the Bianchi type-V bulk viscous barotropic fluid cosmological model with variable gravitational constant G and the cosmological constant A, assuming the condition on metric A/A=B/B=C/C=m/tn potential aswhere A, B, and C are functions of time t, while m and n are constants. To obtain the deterministic mo del, we also assume the relations P = p - 3η H, p = 7P, η = ηop^s, where p is the isotropic pressure, η the bulk viscosity,0≤r≤1 H the Hubble constant, ηo and s are constants. Various physical aspects of the model are *** case of n = 1 is also discussed to compare the results with the actual universe.

关键词： the power-law exponents precipitation durative abrupt precipitation change

Synthesis, Characterization of Phosphorus Containing Diamide-diimide-tetraamines Based on L-Tryptophan Amino Acid and Their Effect on Flame Retardancy of Epoxy Resins

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Chinese Journal of Polymer Science 2014年第2期32卷 197-208页

作者： seema Agrawal Anudeep Kumar Narula GGS Indraprastha University

The curing behavior of diglycidyl ether of bisphenol-A （DGEBA） with different phosphorus containing diamidediimide-tetraamines （DADITAs） was studied by DSC. Eight DADITAs of varying structures were synthesized by reacting 1 mole of pyromellitic anhydride （PMDA）/3,3＇-benzophenone tetracarboxylic dianhydride （BTDA）/1,4,5,8-naphthalene tetraearboxylic dianhydride （NTDA）/4,4＇-oxydiphthalic anhydride （ODPA） with 2 mole of L-tryptophan （T） in a mixture of acetic acid and pyridine （3：2 V/V） followed by activaton with thionyl chloride and then condensation with excess of phosphorus containing triamines tris（3-aminophenyl） phosphine （TAP） and tris（3-aminophenyl） phosphine oxide （TAPO）. DADITAs obtained by reacting PMDA/BTDA/NTDA/ODPA with L-tryptophan followed by condensation with TAP/TAPO were designated as PTAP, PTAPO, BTAP, BTAPO, NTAP, NTAPO, OTAP and OTAPO respectively. The structural characterization of synthesized DADITAs was done by FTIR, ~H-NMR, I3C-NMR, 31p-NMR spectroscopic techniques and elemental analysis. Thermal stability of the isothermally cured epoxy was investigated using dynamic thermogravimetry analysis. The glass transition temperature （Tg） was highest in DGEBA cured using PTAP. All epoxy thermosets exhibited excellent flame retardancy, moderate changes in Tg and thermal stability. Due to presence of phosphorus in curing agents, all epoxy resin systems met the UL-94 V-0 classification and the limiting oxygen index （LOI） reached up to 38.5, probably because of the nitrogen-phosphorus synergistic effect.

关键词： Diamide-diimide-tetraamines DGEBA Curing behavior Thermal stability Flame retardancy.

Preparation by chemical co-precipitation, spectral and electrical characteristics of neodymium orthophosphate nanoparticles

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Journal of Rare Earths 2015年第5期33卷 535-544页

作者： seema Verma K.K.Bamzai Crystal Growth and Material Research Laboratory Department of Physics & Electronics University of Jammu

Nanoparticles of neodymium orthophosphate （NdPO4） were prepared through a facile wet co-precipitation technique. The X-ray diffraction （XRD） studies revealed the material belonging to monoclinic monazite phase with crystallite size of 30.8 nm. Scanning electron microscopic studies showed that the material was composed of a large number of agglomerated spherical particles having grain size of 92 nm. Thermogravimetric analysis suggested that the structural phase transition was seen above 800 °C. The spectroscopic investigations were carried out using Fourier transform infrared spectroscopy （FTIR）. UV-VIS-NIR ab-sorption spectrophotometer showed various transitions from the ground state 4I9/2 to various excited states within the 4f shell and the optical band gap came out to be 3.3 eV. The dielectric constant （ε′）, dielectric loss （tanδ） and ac conductivity ln（σac） were measured in the frequency range of 5 kHz to 1 MHz and in the temperature range of 40 to 500 °C. The dielectric measurement suggested that there was a shift in the value of transition temperature （Tc）, thereby indicating relaxor behaviour of the material. The activation energy value decreased with increase in frequency, thereby suggesting the role of mixed ionic-polaronic conduc-tivity.

关键词： nanoparticles spectroscopic dielectric properties rare earths

Update on pathology of retinoblastoma

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International Journal of Ophthalmology(English edition) 2018年第12期11卷 2011-2016页

作者： Lata Singh seema Kashyap Department of Ocular Pathology Dr.R.P.Centre for Ophthalmic Sciences All India Institute of Medical Sciences

Retinoblastoma is caused by mutational inactivation of both alleles of the RB1 gene, which maps to chromosome 13 q14 and encodes retinoblastoma protein that acts as a tumor suppressor. Histopathological high-risk features of retinoblastoma are predictive of metastasis or local recurrence. The focus of this update is to emphasize the recent advances in pathology, various molecular key pathways and genome wide approaches for newer potential therapeutic future targets associated with retinoblastoma tumor biology. This review article highlights the new biomarkers expressed by the retinoblastoma tumor for the better survival of patients.

关键词： retinoblastoma pathology molecular biology

Seismic wave velocities of rare gas solids through elastic properties in Earth's lower mantle

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Science China Earth Sciences 2009年第10期52卷 1599-1611页

作者： seema GUPTA Suresh C. GOYAL Department of Physics Agra College Faculty of Engineering and Technology Raja Balwant Singh College

The expressions for second (SOE) and third order elastic (TOE) constants for rare gas solids are derived for comparative study of elastic behavior within the framework of many body potentials including the effect of p... 详细信息

关键词： elastic properties seismic wave velocities RGS

Intraocular fine needle aspiration cytology as a diagnostic modality for retinoblastoma

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International Journal of Ophthalmology(English edition) 2016年第8期9卷 1233-1235页

作者： Bhavna Chawla Anand Tomar seema Sen Mandeep S.Bajaj seema Kashyap Ocular Oncology & Paediatric Ophthalmology Service Dr.Rajendra Prasad Centre for Ophthalmic Sciences All India Institute of Medical Sciences Ocular Pathology Service Dr. Rajendra Prasad Centre for Ophthalmic Sciences All India Institute of Medical Sciences

INTRODUCTION The diagnosis of retinoblastoma(RB)is usually made by clinical examination and imaging modalities such as B-scan ultrasonography of the eye,CT scan and MRI of the *** role of fine needle aspiration cytology(FNAC)as a diagnostic modality for RB has been controversial,mainly due to concerns of tumor dissemination and extra-ocular spread[1-2].Although the majority of RB cases can be diagnosed without the need for any invasive procedure,in

关键词： FNAC RB