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Journal of Pharmaceutical Analysis 2017年第1期7卷 71-75页

作者： Susithra Selvam ivy Sarkar Department of Chemistry Vel Tech University Avadi Chennai 600062 Tamilnadu India Department of Chemistry Indian Institute of Technology Madras Chennai 600036 Tamilnadu India

Methylene blue(MB) is a hydrophobic drug molecule, having importance both as a staining reagent and pharmaceutical agent. MB is strongly fluorescent, with an emission peak at 686 nm(λ_(ex)665 nm). In the study,the possibility of MB as an extrinsic fluorophore to study the micellization behavior of bile salts(BSs) was carried out. Since BSs are drug delivery systems, the solubilization of hydrophobic MB drug molecule by BSs was achieved and the nature of association of MB with BS media, namely sodium cholate(Na C) and sodium deoxycholate(Na DC) was evaluated. Change in the photophysical properties of MB is monitored through fluorescence intensity and fluorescence anisotropy at emission peak, 686 nm of MB. Molecular mechanics calculations were carried out to evaluate the MB–BS association. The estimated heat of formation, ΔH_f values are –625.19 kcal/mol for MB–Na C and –757.48 kcal/mol for MB–Na DC. The photophysical study also revealed that MB reports the step-wise aggregation pattern of BSs media, as an extrinsic fluorescence probe.

关键词： Methylene blue Sodium deoxycholate Sodium cholate Absorption Fluorescence spectroscopy Molecular mechanics

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Denaturation studies on bovine serum albumin–bile salt system:Bile salt stabilizes bovine serum albumin through hydrophobicity

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Journal of Pharmaceutical Analysis 2018年第1期8卷 27-36页

作者： Karpagaraj Malarkani ivy Sarkar Susithra Selvama Department of Chemistry Vel Tech UniversityAvadiChennai 600062India Department of Chemistry Indian Institute of Technology MadrasChennai 600036India Department of Chemistry PSG College of TechnologyPeelameduCoimbatore 641004India

Protein denaturation is under intensive research, since it leads to neurological disorders of severe consequences. Avoiding denaturation and stabilizing the proteins in their native state is of great importance,especially when proteins are used as drug molecules or vaccines. It is preferred to add pharmaceutical excipients in protein formulations to avoid denaturation and thereby stabilize them. The present study aimed at using bile salts(BSs), a group of well-known drug delivery systems, for stabilization of *** serum albumin(BSA) was taken as the model protein, whose association with two BSs, namely sodium cholate(Na C) and sodium deoxycholate(Na DC), was studied. Denaturation studies on the preformed BSA-BS systems were carried out under chemical and physical denaturation conditions. Urea was used as the chemical denaturant and BSA-BS systems were subjected to various temperature conditions to understand the thermal(physical) denaturation. With the denaturation conditions prescribed here,the data obtained is informative on the association of BSA-BS systems to be hydrophobic and this effect of hydrophobicity plays an important role in stabilizing the serum albumin in its native state under both chemical and thermal denaturation.

关键词： Bile salts Bovine serum albumin Chemical denaturation Thermal denaturation Tryptophan fluorescence Protein stabilization

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A critical review of carbonate reservoir wettability modification during low salinity waterflooding

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Petroleum 2023年第3期9卷 317-330页

作者： Perekaboere ivy Sagbana Kwame Sarkodie Wilberforce Aggrey Nkrumah Zone 63 District 841DohaQatar Petroleum Engineering Department Kwame Nkrumah University of Science and TechnologyGhana Smart Fluids Laboratory Kwame Nkrumah University of Science and TechnologyGhana

The nature of carbonate reservoirs promotes the adsorption of oil onto the rock surface hence making oil recovery a challenge even with the interventions of varied chemical EOR ***,low salinity water flooding has become of great interest since it is cost-effective and environmentally *** low salinity waterflooding has been highly investigated in sandstone reservoirs,it is not the same for carbonate reservoirs due to its ***,it has been proposed as a favourable technique to mobilise the trapped oil in carbonate *** alteration is regarded as the most accepted mechanism for low salinity flooding but has not been well understood making field scale applications *** this paper,we present a detailed review of the wettability alteration mechanisms in carbonate reservoirs during low salinity *** influencing wettability alteration in carbonates and the interactions that occur at the rock/brine/oil interface are also *** different methods utilised for wettability measurements during low salinity waterflooding are also reviewed including their drawbacks and advantages and *** will provide an improved understanding of the low salinity flooding application in carbonate reservoirs.

关键词： Low salinity flooding Wettability alteration Carbonate rocks

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Polymer interdigitated pillar electrostatic(PIPE)actuators

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Microsystems & Nanoengineering 2022年第1期8卷 185-192页

作者： Di Ni Ronald Heisser Benyamin Davaji Landon ivy Robert Shepherd Amit Lal School of Electrical and Computer Engineering Cornell UniversityIthacaNY 14853USA Sibley School of Mechanical and Aerospace Engineering Cornell UniversityIthacaNY 14853USA

This work reports a three-dimensional polymer interdigitated pillar electrostatic actuator that can produce force densities 5-10×higher than those of biological *** theory of operation,scaling,and stability is investigated using analytical and FEM *** actuator consists of two high-density arrays of interdigitated pillars that work against a restoring force generated by an integrated flexure *** actuator architecture enables linear actuation with higher displacements and pull-in free actuation to prevent the in-use stiction associated with other electrostatic *** pillars and springs are 3D printed together in the same *** pillars are coated with a gold-palladium alloy layer to form conductive *** space between the pillars is filled with liquid dielectrics for higher breakdown voltages and larger electrostatic forces due to the increase in the dielectric *** demonstrated a prototype actuator that produced a maximum work density of 54.6μJ/cc and an electrical-tomechanical energy coupling factor of 32%when actuated at 4000 *** device was operated for more than 100,000 cycles with no degradation in *** flexible polymer body was robust,allowing the actuator to operate even after high mechanical force impact,which was demonstrated by operation after drop *** it is scaled further,the reported actuator will enable soft and flexible muscle-like actuators that can be stacked in series and parallel to scale the resulting *** work paves the way for high-energy density actuators for microrobotic applications.

关键词： alloy electrostatic enable

Mid-Term Preliminary Results for Safety and Patency of the Occlutech Atrial Flow Regulator in an Animal Model

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Congenital Heart Disease 2022年第3期17卷 269-280页

作者： Kamel Shibbani Daniel McLennan Dunbar ivy Gareth Morgan Division of Cardiology Department of PediatricsStead Family Children’s HospitalUniversity of Iowa Hospitals and ClinicsIowa CityUSA Division of Cardiology Department of PediatricsMedical College of WisconsinMilwaukeeUSA Division of Cardiology Heart InstituteChildren’s Hospital of ColoradoUniversity of Colorado at DenverAuroraUSA

Objective:The Atrial Flow Regulator(AFR)is a double disc device made of self-expanding Nitinol wire mesh,structured around a central *** deployed via the transfemoral route,the device stents the atrial septum leaving a preselected fixed diameter atrial *** sought to evaluate the mid-term performance of the AFR by implanting the device in 5 healthy porcine hearts to assess safety and patency of the device fenestration over a period of 150 ***:Five AFR devices were implanted in 5 female Yucatan adult *** animals were survived to 150 days with periodic assessments at days+3,+30,+60,+90,+120,and+*** assessments consisted of transesophageal echocardiography and fluoroscopic *** animals were sacrificed at day+*** and pathological assessments were carried out to characterize neointimal tissue growth,inflammation,thrombus formation,endothelial coverage,endothelial maturity,and the presence of any luminal ***:There were no unscheduled *** was maintained in all 5 animals across the 150-day *** was no statistically significant difference in the lumen diameter over the study *** growth was mild to moderate in all specimens and occurred mostly on the surfaces of the device in direct contact with the atrial *** was no evidence of any significant inflammatory response on routine blood work or by imaging or histological *** electron microscope(SEM)examination showed nearly complete surface coverage with endothelial *** animals were in a healthy condition for the duration of the study with no attributable pathology and no adverse effects noted on distant organs in any of the 5 ***:As a continuation of our earlier work,this 150-day midterm animal study provides important safety and feasibility *** preliminary results show that the AFR is both safe and effective in maintaining a sustainable atrial level communicati

关键词： Atrial flow regulator animal model atrial septal defect interventional cardiology device

Text Sentiment Analysis Based on Multi-Layer Bi-Directional LSTM with a Trapezoidal Structure

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作者： ivy小柔

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Intelligent Automation & Soft Computing 2023年第7期37卷 639-654页

作者： Zhengfang He Cristina E.Dumdumaya ivy Kim D.Machica School of Intelligent Science and Engineering Yunnan Technology and Business UniversityKunming650000China College of Information and Computing University of Southeastern PhilippinesDavao CityDavao del SurPhilippines

Sentiment analysis,commonly called opinion mining or emotion artificial intelligence(AI),employs biometrics,computational linguistics,nat-ural language processing,and text analysis to systematically identify,extract,measure,and investigate affective states and subjective *** analy-sis algorithms include emotion lexicon,traditional machine learning,and deep *** the text sentiment analysis algorithm based on a neural network,multi-layer Bi-directional long short-term memory(LSTM)is widely used,but the parameter amount of this model is too ***,this paper proposes a Bi-directional LSTM with a trapezoidal structure *** design of the trapezoidal structure is derived from classic neural networks,such as LeNet-5 and *** classic models have trapezoidal-like structures,and these structures have achieved success in the field of deep *** are two benefits to using the Bi-directional LSTM with a trapezoidal *** is that compared with the single-layer configuration,using the of the multi-layer structure can better extract the high-dimensional features of the *** is that using the trapezoidal structure can reduce the model’s *** paper introduces the Bi-directional LSTM with a trapezoidal structure model in detail and uses Stanford sentiment treebank 2(STS-2)for *** can be seen from the experimental results that the trapezoidal structure model and the normal structure model have similar ***,the trapezoidal structure model parameters are 35.75%less than the normal structure model.

关键词： Text sentiment Bi-directional LSTM Trapezoidal structure

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Never Quit

新高考(英语进阶) 2015年第Z1期 44-45页

作者： ivy

In 1962,four nervous young musicians played their first record audition for the executives of the Decca Recording *** executives were not *** turning down this group of musicians,one executive said,"We don’t like the... 详细信息

关键词： In

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February

健康之家 2020年第2期 8-9页

作者： ivy

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关键词：免疫系统 February 抑郁情绪

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August

健康之家 2018年第8期 8-9页

作者： ivy

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关键词：反式脂肪 August 致病菌