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Heteromeric and Homomeric Geranyl Diphosphate Synthases from Catharanthus roseus and Their Role in Monoterpene Indole Alkaloid Biosynthesis

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Molecular Plant 2013年第5期6卷 1531-1549页

作者： avanish rai Shachi S. Smita Anup Kumar Singh Karuna Shanker Dinesh A. Nagegowda CSIR-Central Institute of Medicinal and Aromatic Plants Research Centre Bangalore 560065 India CSIR-Central Institute of Medicinal and Aromatic Plants Lucknow 226015 India

Catharanthus roseus is the sole source of two most important monoterpene indole alkaloid （MIA） anti- cancer agents： vinblastine and vincristine. MIAs possess a terpene and an indole moiety derived from terpenoid and shikimate pathways, respectively. Geranyl diphosphate （GPP）, the entry point to the formation of terpene moiety, is a product of the condensation of isopentenyl diphosphate （IPP） and dimethylallyl diphosphate （DMAPP） by GPP synthase （GPPS）. Here, we report three genes encoding proteins with sequence similarity to large subunit （***） and small subunit （***） of heteromeric GPPSs, and a homomeric GPPSs. *** is a bifunctional enzyme producing both GPP and geranyl geranyl diphosphate （GGPP）, *** is inactive, whereas CrGPPS is a homomeric enzyme forming GPP. Co-expression of both subunits in Escherichia coil resulted in heteromeric enzyme with enhanced activity producing only GPR While *** and CrGPPS showed higher expression in older and younger leaves, respectively, *** showed an increasing trend and decreased gradually. Methyl jasmonate （MelA） treatment of leaves sig- nificantly induced the expression of only ***. GFP localization indicated that *** is plastidial whereas CrGPPS is mitochondrial. Transient overexpression of *** in C. roseus leaves resulted in increased vindoline, immediate monomeric precursor of vinblastine and vincristine. Although C. roseus has both heteromeric and homomeric GPPS enzymes, our results implicate the involvement of only heteromeric GPPS with *** regulating the GPP flux for MIA biosynthesis.

关键词： C. roseus monoterpene indole alkaloids geranyl diphosphate synthase heteromer homomer large subunit small subunit vindoline.

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Next-Generation Intelligent MXene-Based Electrochemical Aptasensors for Point-of-Care Cancer Diagnostics

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Nano-Micro Letters 2022年第6期14卷 248-281页

作者： Arpana Parihar Ayushi Singhal Neeraj Kumar Raju Khan MohdAkram Khan avanish KSrivastava Industrial Waste Utilization Nano and BiomaterialsCSIR-Advanced Materials and Processes Research Institute(AMPRI)Hoshangabad RoadBhopal 462026MPIndia Academy of Scientific and Innovative Research(AcSIR) Ghaziabad 201002India

Delayed diagnosis of cancer using conventional diagnostic modalities needs to be addressed to reduce the mortality rate of ***,2 D nanomaterial-enabled advanced biosensors have shown potential towards the early diagnosis of *** high surface area,surface functional groups availability,and excellent electrical conductivity of MXene make it the 2 D material of choice for the fabrication of advanced electrochemical biosensors for disease ***-enabled electrochemical aptasensors have shown great promise for the detection of cancer biomarkers with a femtomolar limit of ***,the stability,ease of synthesis,good reproducibility,and high specificity offered by MXene-enabled aptasensors hold promise to be the mainstream diagnostic *** this review,the design and fabrication of MXene-based electrochemical aptasensors for the detection of cancer biomarkers have been ***,various synthetic processes and useful properties of MXenes which can be tuned and optimized easily and efficiently to fabricate sensitive biosensors have been ***,futuristic sensing applications along with challenges will be deliberated herein.

关键词： MXene Electrochemical devices POCT Aptamer Cancer diagnostics

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Electrochemical Impedance Analysis of Biofunctionalized Conducting Polymer-Modified Graphene-CNTs Nanocomposite for Protein Detection

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Nano-Micro Letters 2017年第1期9卷 104-112页

作者： Shobhita Singal avanish K.Srivastava Rajesh CSIR-National Physical Laboratory Dr.K.S.Krishnan RoadNew Delhi 110012India Academy of Scientific and Innovative Research(AcSIR) CSIR-National Physical LaboratoryDr.K.S.Krishnan RoadNew Delhi 110012India

We report an electrodeposited poly(pyrrole-co-pyrrolepropylic acid) copolymer modified electroactive graphene-carbon nanotubes composite deposited on a glassy carbon electrode to detect the protein antigen(cTnI). The copolymer provides pendant carboxyl groups for the site-specific covalent immobilization of protein antibody, antitroponin I. The hybrid nanocomposite was used as a transducer for biointerfacial impedance sensing for cTnI *** results show that the hybrid exhibits a pseudo capacitive behaviour with a maximum phase angle of 49° near 1 Hz,which is due to the inhomogeneous and porous structure of the hybrid composition. The constant phase element of copolymer is 0.61(n = 0.61), whereas, it is 0.88(n = 0.88) for the hybrid composites, indicating a comparatively homogeneous microstructure after biomolecular functionalization. The transducer shows a linear change in charge transfer characteristic(R_(et)) on cTnI immunoreaction for spiked human serum in the concentration range of 1.0 pg mL^(-1)–10.0 ng mL^(-1). The sensitivity of the transducer is 167.8 ± 14.2 Ω cm^2 per decade, and it also exhibits high specificity and good reproducibility.

关键词： Conducting polymer Graphene Carbon nanotube Hybrid Transducer Protein antigen cTnI Electrochemical impedance

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Experimental studies of water hammer in propellant feed system of reaction control system

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Propulsion and Power Research 2018年第1期7卷 52-59页

作者： avanish Kumar P.Satya Prasad M.Raghavendra Rao Defence Research&Development Laboratory HyderabadTelangana 500058India

Water hammer pressure transient produces large dynamic forces which can damage the pipes and other assemblies in the feed line of a reaction control system(RCS).It has led to the failure of pressure transducers monitoring the manifold pressure in the feed line of ***,water hammer studies have been carried out to understand its effect in feed *** system has been simplified to develop a mathematical model and experiments have been carried out at extensive *** mathematical model was developed considering pipe of uniform c/s and moving liquid-gas *** experimental studies have been done using water as working medium instead of actual *** studies showed that rate of pressurization have a very critical role on the water hammer *** studies have been also carried out to study the effect of density,friction and initial liquid column length on water hammer amplitude.

关键词： Water hammer Reaction control system(RCS) Propellant feed system Experimental study Testing

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Survival, development and life tables of two congeneric ladybirds in aphidophagous guilds

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Insect Science 2006年第2期13卷 119-126页

作者： avanish K. GUPTA SHEFALI SRIVASTAVA GEETANJALI MISHRA KALPANA SINGH OMKAR Ladybird Research Laboratory Department of Zoology University of Lucknow Lucknow India

Two congeneric aphidophagous ladybirds, Coccinella septempunctata and Coccinella transversalis, were reared on three aphid species, Lipaphis erysimi, Myzus persicae and Aphis nerii, to estimate the effect of prey quality and intra- and interspecific interactions on their survival and development of life stages. Mortality of first instar ladybirds of both species was highest feeding on A. nerii. Preimaginal mortafity was lowest when feeding on L. erysimi （C. septempunctata, 1.6% and C. transversalis, 3.2%）, and highest when feeding on A. nerii （ C. septempunctata, 6.2% and C. transversalis, 8.2%）. Comparatively higher weight and larger size of C. septempunctata along with the lower levels of mortality recorded suggested that it is more likely to have acted as an intraguild predator than C. transversalis. High recorded mortality of C. transversalis is attributed to probable intraguild predation on account of its smaller size. The major sources of mortality were probably cannibalism, intraguild predation and other unknown factors. Lower prey quality increased the incidence of cannibalism and intraguild predation, especially in C. transversalis. The investigation suggests an intrinsic competitive advantage for C. septempunctata over C. transversalis in guilds of three aphid species.

关键词： Coccinella septempunctata Coccinella transversalis ladybirds life table,aphids cannibalism intraguild predation

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Signet ring colorectal carcinoma:Do we need to improve the treatment algorithm?

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World Journal of Gastrointestinal Oncology 2016年第12期8卷 819-825页

作者： Anup Sunil Tamhankar Parag Ingle Reena Engineer Munita Bal Vikas Ostwal avanish Saklani Department of Surgical Oncology Tata Memorial Centre Department of Radiotherapy Tata Memorial Centre Department of Surgical Pathology Tata Memorial Centre Department of Medical Oncology Tata Memorial Centre Department of Gastro-Intestinal Surgery Tata Memorial Centre

AIM To elaborate about this peculiar variant from a tertiary cancer center from *** It's a retrospective study(2011-2014) of all patients diagnosed with signet ring colo-rectal cancer(SRCC). Various clinico-pathological variables were *** One hundred and seventy consecutive patients with SRCC were diagnosed(11.4% of all colorectal cancers). Median Age of the cohort was 41 years. Most common location was recto-sigmoid area(54.7%). Majority patients presented in stage III and IV(91.2%). Most of the stage IV patients had isolated peritoneal metastases(86.5%). Colonic tumors had higher incidence of peritoneal metastases(91.8% vs 83.3%) as well as isolated peritoneal recurrences(37.5% vs 16.7%) than rectal primaries. Thirty-seven point five percent of patients recurred after curative surgery. Amongst them 63.63% patients had isolated peritoneal recurrences. Circumferential resection margin(CRM) was involved in 17.9% patients. Median relapse free survival(RFS) and overall survival(OS) of the cohort were 14.9 and 18.13 mo respectively. CRM involvement, colonic primary were associated with poorer RFS and *** SRCC has predilection for peritoneal dissemination. More aggressive and/or extended chemotherapy schedules as well as prophylactic hyperthermic intra-peritoneal chemotherapy at the time of primary surgery may be attempted in these patients.

关键词： Colorectal 癌症图章戒指房间癌腹转移 Hyperthermic intra 腹化疗

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High-yield synthesis and liquid-exfoliation of two- dimensional belt-like hafnium disulphide

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Nano Research 2018年第1期11卷 343-353页

作者： Harneet Kaur Sandeep Yadav avanish K. Srivastava Nidhi Singh Shyama Rath Jorg J. Schneider Om P. Sinha Ritu Srivastava National Physical Laboratory Council of Scientific and Industrial Research Dr. K. S. Krishnan Road New Delhi I I O012 India Academy of Scientific and Innovative Research NPL New Delhi 110012 India Technische Universitat Darmstadt Eduard-ZintMnstitut f~r Anorganische und Physikalische Chemie 12 105 117 Alarich-Weiss-Str 12 64287 Darmstadt Germany DepartmentofPhysics andAstrophysics University of Delhi Delhi 110007 India Amity Institute of Nanotechnology Amity University UP Sector 125 Noida Uttar Pradesh 201313 India

Producing environmentally stable monolayers and few-layers of hafnium disulphide （HfS2） with a high yield to reveal its unlocked electronic and optoelectronic applications is still a challenge. HfS2 is a layered two-dimensional material of group-IV transition metal dichalcogenides. For the first time, we demonstrate a simple and cost-effective method to grow layered belt-like nanocrystals of HfS2 with a notably large interlayer spacing followed by their chemical exfoliation. Various microscopic and spectroscopic techniques confirm that these as-grown crystals exfoliate into single or multiple layers in a few minutes using solvent assisted ultrasonification method in N-cyclohexyl-2- pyrrolidone. The exfoliated nanosheets of HfS2 exhibit an indirect bandgap of 1.3 eV with high stability against surface degradation. Furthermore, we demonstrate that these nanosheets hold potential for electronic applications by fabricating a field-effect transistor based on few-layered HfS2, exhibiting a field-effect mobility of 0.95 cm2/（V.s） with a high on/off current modulation ratio of 10,000 in ambient conditions. The method is scalable and has a potential significance for both academic and industrial purposes.

关键词： two-dimensionalmaterials hafnium disulphide nano-crystals liquid-phase exfoliation environment-stabili~ field-effect transistor

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Modification at Lattice Scale for an Optimized Optical Response of Al<sub>x</sub>(ZnO)<sub>1-x</sub>Nanostructures

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World Journal of Nano Science and Engineering 2011年第1期1卷 15-19页

作者： avanish Kumar Srivastava Karuppanan Senthil Melepurath Deepa Ruchi Gakhar Jai Shankar Tawale 不详

We report the systematic changes of nano-scaled features and optical properties in a promising transparent oxide material, namely, Alx (x = 0, 1, 2 and 5%) doped ZnO1-x (AZO). Electron microscopy investigations revealed the alterations at lattice scale depending on the presence of Al-content in ZnO nanostructures. Lattice spacings of 0.26 and 0.28 nm oriented along the (0002) and (10 0) planes, respectively, were attributed to euhedral-and facetted-structures of hexagonal-ZnO. The AZO samples were further characterized by XRD, SEM, UV-vis spectrophotometry, Raman spectroscopy and photoluminescence studies. It has been shown that at a dopant concentration of 2%Al in ZnO, an optimal balance could be achieved between microstructure and optical properties.

关键词： Electron Microscopy Nanostructures ZnO Photoluminescence

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Magnetic resonance imaging in rectal cancer:A surgeon's perspective

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World Journal of Gastroenterology 2014年第8期20卷 2030-2041页

作者： avanish P Saklani Sung Uk Bae Amy Clayton Nam Kyu Kim Section of Colon and Rectal Surgery Department of SurgeryYonsei University College of MedicineSeoul 120527South Korea Radiology Department University Hospital of WalesCF14 4XW CardiffUnited Kingdom Department of Colorectal Surgery Severance HospitalSeoul 120527South Korea

Magnetic resonance imaging(MRI)in rectal cancer was first investigated in 1999 and has become almost mandatory in planning rectal cancer *** has a high accuracy in predicting circumferential resection margin involvement and is used to plan neoadjuvant *** accuracy of MRI in assessing mesorectal lymph nodes remains moderate,as there are no reliable criteria to assess nodal *** seems to be good in assessing peritoneal involvement in upper rectal cancer;this however has been assessed in only a few studies and needs further *** low rectal cancers,mesorectum is thin at the level of levator ani especially in relation to prostate;so predicting circumferential resection margin involvement is not *** high spatial resolution coronal imaging shows levator muscles,sphincter complex and intersphincteric plane *** is used to stage low rectal tumors and plan plane of surgery(standard surgery,intersphincteric resection,Extralevator abdominoperineal resection).While most centres perform MRI post chemoradiotherapy,its role in accurate staging post neoadjuvant therapy remains *** role of Diffusion weighted MRI post neoadjuvant therapy is being evaluated in research settings.

关键词： Magnetic resonance imaging Rectal cancer Surgeon

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Growth of Boron Nitride Nanotubes Having Large Surface Area Using Mechanothermal Process

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World Journal of Nano Science and Engineering 2011年第4期1卷 119-128页

作者： Sunil K. Singhal avanish K. Srivastava Rakesh B. Mathur 不详

Nanostructures of boron nitride (BN) including nanotubes, nanofibers and nanosheets having a large surface area are very useful in storing hydrogen and other gases. In the present paper we report the synthesis and characterization of these nanostructures of BN using mechanothermal process. Under this process elemental boron powder is first ball milled to about 50 h in an inert atmosphere and then annealed at 1100℃ - 1250℃ for 6 h in the presence of NH3 gas. By this treatment nanotubes and other nanostructures of BN were synthesized. The diameter of BN nanotubes varied from 20 to 50 nm and most of them exhibited spindle or bamboo like morphology. Because of the large surface area, these nanotubes may be explored for a better hydrogen gas storage device as compared to the crystallized nanotubes. The main advantage of this technique is that the nanotubes can be grown in large quantity. A possible growth mechanism towards the evolution of such fascinating nano-objects of boron nitride has been discussed employing high-resolution transmission electron microscopy and photoluminescence.

关键词： Boron Nitride Nanotubes Mechanothermal Process Morphology Photo Luminescence

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