检索结果-南通市图书馆

Absorption and emission modulation in a MoS2–GaN（0001） heterostructure by interface phonon–exciton coupling

Photonics Research 2019年第12期7卷 1511-1520页

作者： YUBA POUdEL JAGOdA SLAWINSKA PRIYA GOPAL SAIRAMAN SEETHARAMAN ZACHARIAH HENNIGHAUSEN SWASTIK KAR FRANCIS d'souza MARCO BUONGIORNO NARdELLI ARUP NEOGI department of Physics University of North TexasDentonTexas 76203USA department of Chemistry University of North TexasDentonTexas 76203USA department of Physics Northeastern UniversityBostonMassachusetts 02115USA

Semiconductor heterostructures based on layered two-dimensional transition metal dichalcogenides(TMds)interfaced to gallium nitride(Ga N)are excellent material systems to realize broadband light absorbers and emitters due to their close proximity in the lattice *** surface properties of a polar semiconductor such as Ga N are dominated by interface phonons,and thus the optical properties of the vertical heterostructure are influenced by the coupling of these carriers with *** activation of different Raman modes in the heterostructure caused by the coupling between interfacial phonons and optically generated carriers in a monolayer MoS_2–Ga N(0001)heterostructure is *** excitonic states in MoS_2 are close to the interband energy state of intraband defect state of Ga *** functional theory(dFT)calculations are performed to determine the band alignment of the interface and revealed a type-I *** close proximity of the energy levels and the excitonic states in the semiconductors and the coupling of the electronic states with phonons result in the modification of carrier relaxation *** of the excitonic absorption states in MoS_2 is measured by transient optical pump-probe spectroscopy and the change in emission properties of both semiconductors is measured by steady-state photoluminescence(PL)emission *** is significant red-shift of the C excitonic band and faster dephasing of carriers in MoS_***,optical excitation at energy higher than the bandgap of both semiconductors slows down the dephasing of carriers and energy exchange at the *** and blue-shifted PL emission is observed in MoS_*** N band-edge emission is reduced in intensity at room temperature due to increased phonon-induced scattering of carriers in the Ga N *** results demonstrate the relevance of interface coupling between the semiconductors for the development of optical and electronic applications.

关键词： spectroscopy. coupling interface

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Kinetic Rates of the Fischer Tropsch Synthesis on a Co/Nb_2O_5 Catalyst

引用

Journal of Natural Gas Chemistry 2006年第4期15卷 307-312页

作者： Víctor R.Ahón Paulo L.C.Lage Carlos d.d.de souza Fabiana M.Mendes Martin Schmal Federal University of Rio de Janeiro Programa de Engenharia Química COPPE/UFRJ C.P.6850221941-972Rio de JaneiroRJBrazil

The kinetics of the Fischer-Tropsch reaction over a Co/Nb2O5 catalyst in a fixed bed reactor was investigated experimentally. Experiments were carried out under isothermal and isobaric conditions （T=543 K, P=2.1 MPa） and under different conditions of several H2/CO feed molar ratio （0.49-4.79）, space velocities （0.2-3.8 h^-1）, mass of catalyst （0.3-1.5 g）, and CO conversion （10%-29%）. Synthesis gas conversion was measured and data were reduced to estimate the kinetic parameters for different Langmuir-Hinshelwood rate expressions. differential and integral reactor models were used for the nonlinear regression of kinetics parameters. One of the rate equations could well explain the data. The hydrocarbon product distributions that were experimentally determined exhibited an unusual behavior, and a possible explanation was discussed.

关键词： Fischer-Tropsch natural gas kinetics selectivity

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

An open-access endoscopy screen correctly and safely identifies patients for conscious sedation

引用

Gastroenterology Report 2016年第4期4卷 281-286,I0001页

作者： darshan Kothari Joseph d.Feuerstein Laureen Moss Julie d’souza Kerri Montanaro daniel A.Leffler Sunil G.Sheth department of Medicine and division of Gastroenterology Beth Israel Deaconess Medical CenterHarvard Medical SchoolBostonMAUSA department of Nursing Beth Israel Deaconess Medical CenterHarvard Medical SchoolBostonMAUSA

Background and aims:Open-access scheduling is highly utilized for facilitating generally low-risk *** screening addresses sedation requirements;however,procedural safety may be compromised if screening is *** sought to determine the reliability of our open-access scheduling system for appropriate use of conscious ***:We prospectively and consecutively enrolled outpatient procedures booked at an academic center by open-access using screening after in-office gastroenterology(GI)*** collected the cases inappropriately booked for conscious sedation and compared the characteristics for significant ***:A total of 8063 outpatients were scheduled for procedures with conscious sedation,and 5959 were booked with *** 78 patients(0.97%,78/8063)were identified as subsequently needing anesthesiologist-assisted sedation;44(56.4%,44/78)were booked through open-access,of which chronic opioid(47.7%,21/44)or benzodiazepine use(34.1%,15/44)were the most common reasons for needing anesthesiologist-assisted *** on chronic benzodiazepines required more midazolam than those not on chronic benzodiazepines(P=0.03)of those patients who underwent conscious ***,patients with chronic opioid use required more fentanyl than those without chronic opioid use(P=0.04).Advanced liver disease and alcohol use were common reasons for patients being booked after in-office consultation and were significantly higher than those booked with open-access(both Pd that the majority of patients can be triaged for conscious sedation using a multi-tiered screening ***,few patients(d for conscious *** most common reasons for considering anesthesiologist-assisted sedation were chronic opioid,benzodiazepine and/or alcohol use and advanced liver *** suggests that these entities could be included in screening proces

关键词： open-access endoscopy sedation screen

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Experimental Thermal Performance of different Capillary Structures for Heat Pipes

引用

Energy Engineering 2021年第1期118卷 1-14页

作者： L.Krambeck G.A.Bartmeyer d.O.souza d.Fusão P.H.d.Santos T.Antonini Alves Federal University of Technology—Parana(UTFPR) Ponta Grossa84.017-220Brazil Federal University of Technology-Parana(UTFPR) Curitiba81.280-340Brazil

The temperature control in electronic packaging is the key in numerous applications,to avoid overheating and hardware *** to high capability of heat transfer,good temperature uniformity,and no power consumption,heat pipes can be widely used for heat dissipation of electronic *** paper reports an experimental thermal analysis of different capillary structures for heat *** wicks considered are metal screens,axial microgrooves,and sintered metal *** heat pipes are made of copper,a 200 mm length tube and a 9.45 mm external *** fluid used was distilled *** devices are investigated in three positions:0,90,and 270°to the horizontal under powers of 5 up to 45 *** results show that in horizontal(0°)and with the evaporator under the condenser(270°),the heat pipes showed similar ***,in the reverse condition(the position against the gravity with the evaporator above the condenser,90°),the heat pipe with sintered wick presented the best thermal performance,as it has the lowest thermal resistance and supported a higher *** that,the sintered powder capillary structure demonstrates the most homogeneous thermal behavior for every position,making the most suitable for applications susceptible to diverse inclinations.

关键词： Heat pipes capillary structure thermal performance sintered wick

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Role of microbial dysbiosis in the pathogenesis of esophageal mucosal disease:A paradigm shift from acid to bacteria?

引用

World Journal of Gastroenterology 2021年第18期27卷 2054-2072页

作者： Steve M d'souza Kevin Houston Lauren Keenan Byung Soo Yoo Parth J Parekh david A Johnson department of Internal Medicine Division of GastroenterologyEastern Virginia Medical SchoolNorfolkVA 23502United States

Genomic sequencing,bioinformatics,and initial speciation(e.g.,relative abundance)of the commensal microbiome have revolutionized the way we think about the“human”body in health and *** interactions between the gut bacteria and the immune system of the host play a key role in the pathogenesis of gastrointestinal diseases,including those impacting the *** relatively stable,there are a number of factors that may disrupt the delicate balance between the luminal esophageal microbiome(EM)and the *** changes are thought to be a product of age,diet,antibiotic and other medication use,oral hygiene,smoking,and/or expression of antibiotic products(bacteriocins)by other *** effects may lead to persistent dysbiosis which in turn increases the risk of local inflammation,systemic inflammation,and ultimately disease *** has suggested that the etiology of gastroesophageal reflux disease-related esophagitis includes a cytokine-mediated inflammatory component and is,therefore,not merely the result of esophageal mucosal exposure to corrosives(i.e.,acid).Emerging evidence also suggests that the EM plays a major role in the pathogenesis of disease by inciting an immunogenic response which ultimately propagates the inflammatory ***,we discuss the potential role for manipulating the EM as a therapeutic option for treating the root cause of various esophageal disease rather than just providing symptomatic relief(i.e.,acid suppression).

关键词： Microbiome Gastroesophageal reflux disease Probiotics Prebiotics Bacteriocins dysbiosis Barrett’s esophagus Esophageal cancer Esophagitis Eosinophilic esophagitis

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

diporphyrin tweezer for multichannel spectroscopic analysis of enantiomeric excess

引用

Frontiers of Chemical Science and Engineering 2020年第1期14卷 28-40页

作者： daniel T.Payne Mandeep KChahal Vaclav Brezina Whitney A.Webre Katsuhiko Ariga Francis d’souza Jan Labuta Jonathan P.Hill WPI Center for Materials Nanoarchitectonics National Institute for Materials ScienceIbaraki 305-0044Japan department of Macromolecular Physics Faculty of Mathematics and PhysicsCharles University18000 PragueCzech Republic department of Chemistry University of North TexasDentonTX 76203USA department of Advanced Materials Science Graduate School of Frontier SciencesThe University of TokyoChiba 277-8561Japan

Chiral 1,1’-binaphthyl-linked diporphyrin‘tweezers’(R)-1/(S)-1 and the corresponding zinc(II)complexes(R)-2/(S)-2 were prepared as chiral host molecules,and their utility for chiral analyses(especially enantiomeric excess(ee)determinations)were ***(1-n-dodecyl)porphyrins were used for the first time as the interacting *** capabilities of the diporphyrin tweezers were investigated by titrations with(R,R)-and(S,S)-cyclohexane-1,2-diamine(CHdA).The host molecules could be used as multichannel probes of ee by using UVvis,circular dichroism(Cd),fluorescence emission and 1H nuclear magnetic resonance(1 H-NMR)*** configurations could also be differentiated using Cd or 1HNMR *** three optical techniques give good resolution of ee with reasonable sensitivity considering the low concentrations used(ca.10^-6 mol·L^-1).The ee determination of CHdA enantiomers using NMR spectroscopy is also possible because of the reasonably well separated resonances in the case of(R,R)-and(S,S)-***-metallated(R)-1/(S)-1 hosts could not be used to detect chiral information in a strongly acidic chiral *** work demonstrates the utility of 1,1’-binapthyllinked chiral hosts for chiral analysis of ditopically interacting enantiomers.

关键词： porphyrin dimer chirality enantiomeric excess Cd fluorescence

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Lunasin protease inhibitor concentrate decreases pro-infl ammatory cytokines and improves histopathological markers in dextran sodium sulfate-induced ulcerative colitis

引用

Food Science and Human Wellness 2022年第6期11卷 1508-1514页

作者： Andrea Nieto-Veloza Zhihong Wang Qixin Zhong doris d’souza Hari B.Krishnan Vermont P.dia department of Food Science University of TennesseeKnoxville 37996USA Agricultural Research Service USDAColumbia 65211USA

Lunasin protease inhibitor concentrate(LPIC)is a novel combination of soy bioactive peptide lunasin,Kunitz and Bowman-Birk protease *** reported anti-inflammatory and anticancer properties of each one of them suggest LPIC as a promising candidate for the treatment of infl ammatory-related *** objective was to assess the in vivo anti-infl ammatory properties of ***,an in vitro test was performed in lipopolysaccharide(LPS)-activated RAW264.7 murine macrophages by measuring the production of nitric oxide(NO),interleukin-6(IL-6),and tumor necrosis factorα(TNF-α)as infl ammatory *** the in vivo model,ulcerative colitis(UC)was induced in mice via oral administration of dextran sodium sulfate(dSS).LPIC treatment was performed via daily intraperitoneal injection of 50 mg/kg body *** weight,visible blood in stool and stool consistency were scored daily as macroscopic indicators of disease *** blood was evaluated by the presence of hemoglobin in stool every third *** length,caecum weight,colonic myeloperoxidase activity(MPO),presence of pro-inflammatory cytokines in blood and colon,changes in the architecture,and expression of inducible nitric oxide synthase(i NOS)in colonic tissue were *** vitro,LPIC induced production of NO and maintained cytokine levels in comparison to activated untreated *** vivo,LPIC increased colonic bleeding and did not improve macroscopic markers of the disease,but reduced colonic IL-1βand IL-6,decreased systemic circulation of TNF-α,attenuated neutrophils infi ltration and i NOS expression in colonic tissue,and diminished the damage in colonic *** results suggest that combinations of peptides in LPIC may counteract the antiinfl ammatory properties in vitro;while in vivo,LPIC can signifi cantly reduce the histopathological damage,hence is a possible therapeutic strategy to attenuate UC.

关键词： Bio-peptides Cytokines Infl ammation Protease inhibitor Ulcerative colitis

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Antioxidant and antihyperlipidemic activity of Costus speciosus against atherogenic diet-induced hyperlipidemia in rabbits

引用

Journal of Integrative Medicine 2019年第3期17卷 181-191页

作者： Fatma Mohamed Hussein Shediwah Khalid Mohammed Naji Hussein Saleh Gumaih Fatima A Alhadi Amani Lutf Al-Hammami Myrene Roselyn d'souza department of Biology Faculty of ScienceSana'a University department of Chemistry Faculty of ScienceSana'a University Chemical Ecology Department of BiologyUniversity of Konstanz department of Biochemistry Mount Carmel College

Objective: An extract of Costus speciosus(CSE), a herb widely used in folk medicine, was evaluated for its antioxidant, antihyperlipidemic and ameliorating effects on histopathological changes in atherogenic ***: Twenty-four male rabbits(Oryctolagus cuniculus) were divided into 4 groups. Three groups were fed a diet containing 3% saturated fat and 1.3% cholesterol for 40 d. One of these was sacrificed on the 40 th day and was called the pathogenic(P) group; the other two groups received treatment for another 30 d as follows: one received 0.8 g/(kgád) of CSE and the other was given 0.01 g/(kgád) of simvastatin. The normal group was sacrificed on the 70 th day and used as a ***: CSE showed radical-scavenging ability. Administration of CSE for a 30-day period resulted in a significant decrease in total cholesterol, triacylglycerol, low-density lipoprotein and aspartate aminotransferase compared to the P group, while levels of hemoglobin, packed corpuscular volume and red blood cells were elevated. With respect to studies performed on the heart, a decrease in malondialdehyde and an increase in reduced glutathione were noted. Total protein increased in the liver, heart and aorta after treatment with CSE and also a marked improvement in histopathological parameters was ***: The present findings indicate that the C. speciosus rhizome possesses antiatherogenic and antioxidant properties which may provide protective effects against oxidative stress in atherosclerotic rabbits.

关键词： Antioxidants Atherosclerosis Costus speciosus Lipid profile Myocardial infraction Simvastatin

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Singlet Oxygen Generation and Photoinduced Charge Separation of Tetra Polyethyleneglycol Functionalized Zinc Phthalocyanine-Fullerene dyad

引用

Chinese Journal of Chemistry 2016年第10期34卷 969-974页

作者： Habtom B. Gobeze Ta Tram Chandra B. KC Robert R. Cantu Paul A. Karr Francis d'souza department of Chemistry University of North Texas 1155 Union Circle #305070 Denton TX 76203-5017 USA department of Physical Sciences and Mathematics Wayne State College 111 Main Street Wayne Nebraska 68787 USA Advanced Materials and Manufacturing Processes Institute (A MMPI) UNT-Discovery Park 3940 N. Elm St. #E132 Denton TX 76207-7102 USA

Utilization of polyethyleneglycol （PEG） functionalized zinc phthalocyanine, （PEG）4ZnPc in （i） singlet oxygen generation, and （ii） in building energy harvesting donor-acceptor systems using fullerene, C60 as an acceptor via the well-known metal-ligand axial coordination approach is reported. The （PEG）4ZnPe was found to be capable of producing singlet oxygen with a quantum yield, ooa of 0.77 in toluene, a value higher than that obtained for pristine （t-bu）4ZnPc （φ△=0.54） carrying no PEG groups, revealing its usefulness in photodynamic therapy applications. Spectroscopic studies revealed efficient binding of phenylimidazole functionalized fullerene, C60 Im with l ： 1 stoichiometry to （PEG）4ZnPc. Binding constant K for the formation of （PEG）4ZnPc：ImC60 dyad was found to be 6 × 103 M 1 revealing moderate stability. Geometric and electronic studies of the dyad was arrived by B3LYP/3-21G（＊） method. The HOMO level was found to be on zinc phthalocyanine entity while the LUMO level was found to be on the C60 entity suggesting formation of （PEG）4ZnPc＊＋：ImC60＊ charge separated state during the process of electron transfer reaction. Redox studies on the （PEG）4ZnPc：ImC60 dyad enabled accurate determination of the oxidation and reduction potentials of the donor-acceptor system, and to evaluate free-energy changes associated for the charge separation process. Kinetics of photoinduced charge separation and recombination in the （PEG）4ZnPc：ImC60 dyad was investigated using femtosecond transient absorption studies. Relatively long-lived charge separated states were confirmed for the dyad suggesting their potential usefulness in energy harvesting applications.

关键词： singlet oxygen photoinduced charge separation zinc phthalocyanine fullerene self-assembly

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Parenting dilemmas of Our day

引用

空中英语教室（高级版．彭蒙惠英语） 2020年第3期 32-34,46,47页

作者： Karen d'souza 不详

Catherine Amores is shopping around for a new smartphone,only it's not for ***'s for her 8-year-old son,*** stay-at-home mom says she will feel safer if her second-grader has an iPhone with him at all times.“There was a school lockdow n in our neighborhood ***'s why I think it is very important to get him a smartphone,”said the Hayward,California,mother.“Being able to get a hold of him immediately will give me peace of mind.”

关键词： smart shopping mother

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：