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Practical and modular construction of benzo[c]phenanthridine compounds

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Science China Chemistry 2022年第7期65卷 1338-1346页

作者： Cheng Zhang Qian Chen Lei Wang Qiaoying Sun Yangyang Yang Matthias Rudolph Frank Rominger a.stephen k.hashmi Organisch-Chemisches Institut Heidelberg UniversityHeidelberg 69120Germany Chemistry Department Faculty of ScienceKing Abdulaziz University(KAU)Jeddah 21589Saudi Arabia Cellular Immunotherapy Lab the Medical Faculty of Heidelberg UniversityHeidelberg University HospitalHeidelberg 69120Germany

Here,we describe a general and modular strategy for the rapid assembly of benzo[c]phenanthridine(BCP)derivatives using homogeneous gold ***,in contrast to traditional methods based on the specially preformed substrates that have an inherent preference for the formation of this class of compounds with limited flexibility,this protocol is achieved via a selectively intramolecular cascade of a diazo-tethered alkyne and subsequently an intermolecular cyclization with a nitrile to facilitate the successive C–N and C–C bonds *** methodology uses readily available nitriles as the nitrogen source to deliver the products in good yield with excellent functional group compatibility.A preliminary anti-tumor activity study of these generated products exhibits high anticancer potency against five tumor cell lines,including He La,Mel624,SW-480,8505C,***,we report a catalyst-controlled intermolecular cycloaddition/intramolecular insertion of the substrate with a fulvene to provide fused polycarbocycles containing a seven-membered ring.

关键词： selectivity homogeneous gold catalysis domino cyclization benzo[c]phenanthridine(BCP) anticancer activity

Easy access to pharmaceutically relevant heterocycles by catalytic reactions involving a-imino gold carbene intermediates

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Frontiers of Chemical Science and Engineering 2020年第3期14卷 317-349页

作者： Ximei Zhao Matthias Rudolph Abdullah M.Asiri a.stephen k.hashmi Organisch-Chemisches Institut Heidelberg University69120 HeidelbergGermany Chemistry Department Faculty of Science21589 JeddahSaudi Arabia

This review summarizes recent advances in the field of gold-catalyzed synthesis of pharmaceutically relevant aza-heterocycles via in situ generated a-imino gold carbene complexes as intermediates.

关键词： gold heterocycles alkynes

Comparison of methods for deriving phenotypes from incomplete observation data with an application to age at puberty in dairy cattle

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Journal of Animal Science and Biotechnology 2024年第2期15卷 535-545页

作者： Melissa a.stephen Chris R.Burke Jennie E.Pryce Nicole M.Steele Peter R.Amer Susanne Meier Claire V.C.Phyn Dorian J.Garrick DairyNZ Ltd 605 Ruakura RoadHamilton 3240New Zealand AL Rae Centre for Genetics and Breeding-Massey University RuakuraHamilton 3214New Zealand Agriculture Victoria Research AgriBioCentre for AgriBioscienceBundooraVictoria 3083Australia School of Applied Systems Biology La Trobe UniversityBundooraVictoria 3083Australia AbacusBio DunedinNew Zealand

Background Many phenotypes in animal breeding are derived from incomplete measures,especially if they are challenging or expensive to measure *** include time-dependent traits such as reproductive status,or *** measures for these traits result in phenotypes that are subject to left-,interval-and rightcensoring,where phenotypes are only known to fall below an upper bound,between a lower and upper bound,or above a lower bound *** we compare three methods for deriving phenotypes from incomplete data using age at first elevation(>1 ng/mL)in blood plasma progesterone(AGEP4),which generally coincides with onset of puberty,as an example *** We produced AGEP4 phenotypes from three blood samples collected at about 30-day intervals from approximately 5,000 Holstein–Friesian or Holstein–Friesian×Jersey cross-bred dairy heifers managed in 54 seasonal-calving,pasture-based herds in New *** used these actual data to simulate 7 different visit scenarios,increasing the extent of censoring by disregarding data from one or two of the three *** methods for deriving phenotypes from these data were explored:1)ordinal categorical variables which were analysed using categorical threshold analysis;2)continuous variables,with a penalty of 31 d assigned to right-censored phenotypes;and 3)continuous variables,sampled from within a lower and upper bound using a data augmentation *** Credibility intervals for heritability estimations overlapped across all methods and visit scenarios,but estimated heritabilities tended to be higher when left censoring was *** sires with at least 5 daughters,the correlations between estimated breeding values(EBVs)from our three-visit scenario and each reduced data scenario varied by method,ranging from 0.65 to *** estimated breed effects also varied by method,but breed differences were smaller as phenotype censoring *** Our results indicate that using

关键词： Cattle Gibbs sampler Markov-chain Monte Carlo(MCMC) Puberty

Incense smoke(IS)inhalation exposure system:Physicochemical characterization,IS particle deposition and clearance in human airway using MPPD model

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Particuology 2024年第4期87卷 271-285页

作者： Vyas kumar Hafsa hashmi Anshita Nasreen Ghazi Ansari Jyotsna Singh Inhalation Toxicology Facility Regulatory Toxicology GroupCSR-Indian Institute of Toxicology ResearchLucknow22001UPIndi Academy of Scientific and Innovative Research(AcsSIR) Ghaziabad201002UPIndia Analytical Chemistry Regulatory Toxicology GroupCSIR-Indian Institute of Toxicology ResearchLucknow226001UPIndia

Incense smoke(IS)is source of indoor air pollution and key risk for diverse human *** in-formation is available regarding controlled IS rodent inhalation exposure system and IS particulate matter(PM)deposition in human *** aimed to demonstrate stable ISPM physicochemical parameters of 10 incense products inside the customized whole body inhalation exposure chamber(without animal)connected to smoke generation unit via aerosol mixing *** analyzed for size segregated PM emission,ISPM in vitro aerodynamics(MMAD and GSD determination),fine and ultrafine particle's SEM,SEM-EDX and PAH *** real life exposure scenario by utilizing MMAD,GSD and PM concentration after Tier 1 exposure assessment as key input parameters,ISPM dosimetry in infant(3 months)and adult(21 years male and female)human airways was calculated using multiple-path particle dosimetry(MPPD 3.04)*** median aerodynamic diameter(MMAD)and geo-metric standard deviation(GSD)ranged between 0.55 and 2.10μm and 1.22 to 1.77(polydisperse)***1.0 and PM0.1 showed multiple morphology and presence of heavy and trace *** like acenaphthylene,anthracene,fluorene,naphthalene and phenanthrene were detected(0.84-143.17μg/g).MPPD results showed higher ISPM deposition in pulmonary region and lowest in trachea bronchial *** deposition in tissue was higher in lower,peripheral lung as compared to upper and central lung *** body inhalation exposure system showed stable IS atmosphere(physi-cochemical parameters)indicating the device suitability in future inhalation *** ISPM deposition fraction and clearance data showed deep lung penetrating and retention behavior with higher risk in infant followed by female and then *** modeled particle deposition and clearance data may be useful in risk assessment analysis of IS.

关键词： Inhalation Incense smoke Multiple-path particle dosimetry(MPPD) Particle deposition Particulate matter(PM) Mass median aerodynamic diameter (MMAD) Human airway

Deciphering the role of rGO in tuning dielectric properties of Er_(2)O_(3)/ZnO/rGO nanocomposites synthesized via facile approach

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Journal of Rare Earths 2024年第3期42卷 578-585,I0006页

作者： Saiqa Hafeez Saima Perveen Muhammad Zarrar khan Awab hashmi Fahad Azad School of Natural Sciences(SNS) National University of Sciences and Technology(NUST)IslamabadPakistan Electronic and Magnetic Materials Laboratory School of Chemical and Materials Engineering(SCME)National University of Sciences and Technology(NUST)IslamabadPakistan

The present research investigated the effect of reduced graphene oxide(rGO) integration with assynthesized Er_(2)O_(3)/ZnO nanocomposites on dielectric properties. The samples were characterized by Xray diffraction(XRD), Fourier transform infrared spectroscopy(FTIR), scanning electron microscopy(SEM), diffuse reflectance spectroscopy(DRS), and energy dispersive spectroscopy(EDS). Complex impedance spectroscopy was utilized to characterize dielectric relaxation phenomena in Er_(2)O_(3)/ZnO and Er_(2)O_(3)/ZnO/rGO nanocomposites. All the samples exhibit single relaxation phenomena which are ascribed to grain boundaries. The addition of rGO to Er_(2)O_(3)/ZnO nanocomposite results in the enhancement of dielectric response due to increased local field intensity caused by the formation of conductinginsulating interfaces. Furthermore, the AC conductivity of the Er_(2)O_(3)/ZnO/rGO is increased at higher frequencies due to the presence of free charge carriers in rGO. At higher frequencies, Er_(2)O_(3)/ZnO/rGO nanocomposite with increased concentration of ZnO exhibits a more stable dielectric constant with extremely low dielectric loss. Hence, the inclusion of rGO in Er_(2)O_(3)/ZnO nanocomposites makes it a novel prospective candidate in the field of energy storage devices.

关键词： Erbium oxide(Er_(2)O_(3)) Rare earths Stable dielectric constant Impedance Polarization Grain boundaries

Exploring the synergy of the eyebrain connection:neuromodulation approaches for neurodegenerative disorders through transcorneal electrical stimulation

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Neural Regeneration Research 2024年第10期19卷 2097-2098页

作者： Antara Verma.stephen k.Agadagba Leanne Lai-Hang Chan Department of Electrical Engineering City University of Hong KongKowloonHong Kong Special Administrative RegionChina Centre for Eye and Vision Research Ltd. Hong Kong Special Administrative RegionChina Pennsylvania State University University ParkPAUSA

The connection and interaction between the eye and the brain are crucial to understanding brain disorders(Marchesi et al.,2021).Both the eye and the brain have a limited regenerative capacity as there are few progenitor cells,and nerve cells do not ***,neurodegeneration implicates irreversible damage to the central nervous system,as observed in several neurodegenerative diseases(Marchesi et al.,2021).

关键词： stimulation degenerative

Volatility and Dynamic Herding in Energy Sector of Developed Markets During COVID-19:A Markov Regime-Switching Approach

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Fudan Journal of the Humanities and Social Sciences 2024年第1期17卷 115-138页

作者： Zuee Javaira Najam Us Sahar Syed Danial hashmi Iram Naz Federal Urdu University of Arts Science and Technology FUUASTIslamabadPakistan AFIPGM National University of Medical SciencesRawalpindiPakistan Faculty of Management Sciences Riphah International UniversityIslamabadPakistan College of Signals National University of Science and TechnologyIslamabadPakistan

This study examines a novel relationship between volatility and dynamic herding behavior during COVID-19 by examining the relationship of oil market volatility,Global volatility and Infectious disease equity market volatility with time-varying herding behavior in energy stock of Developed *** country level data,this study observes that market switch between anti-herding to herding state during pandemic and all three volatility measures have significant impact on dynamic herding state under high dispersion ***,in low dispersion regime only global volatility has significant impact on time-varying herding *** study suggests that the level of speculation in energy sector affect investor behavior;therefore,policy makers should monitor and model possible signals related to health crisis that can be transformed in to financial market crisis.

关键词： Herding Energy sector COVID-19 Volatility Markov regime approach

DEM investigation of strength and critical state behaviours of granular materials under true triaxial loadings

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Particuology 2024年第2期85卷 198-212页

作者： Minyi Zhu Guobin Gong Jun Xia.stephen Wilkinson Department of Civil Engineering Xi'an Jiaotong-Liverpool UniversityChina Department of Civil Engineering and Industrial Design University of LiverpoolLiverpoolUK Faculty of Engineering and Information Sciences University of Wollongong in DubaiUnited Arab Emirates

This paper investigates the strength and critical state(CS)behaviours of granular materials via DEM simulations of true triaxial drained tests under three different loading modes including constant b(in-termediate stress ratio)tests with constantσ'1(major principal stress),constant p(mean pressure)and constantσ'3(minor principal stress)*** this end,a series of samples are generated with the same particle size distribution,and with the confining stresses ranging from 100 kPa to 900 *** CS is achieved for all *** the macroscopic behaviours and the microscopic behaviours are examined and compared considering different loading modes,confining stresses and intermediate stress ratios(b).The critical state lines(CSLs)are found to be unique and independent of the loading modes,but dependent on the b *** CSLs with b=0 and b=1 form the two boundaries of CSLs respectively beyond which CSLs under all other b tests cannot go *** different strength criteria are examined and compared in terms of both peak and CS *** Mohr-Coulomb strength criterion is found to be only suitable for axisymmetric loading *** Lade-Duncan criterion is only suitable for describing peak strengths,which is dependent on the loading modes and confining *** Satake criterion and Matsuoka-Nakai criterion are the more appropriate strength criteria for describing CS failures,indicating that the CS values of both the Satake parameter and the Matsuoka-Nakai parameter describe an inherent property that characterizes the CS failure for a given type of *** CS mechanical coordination number is fitted by a curved line for a given b value,which is unique regardless of the loading *** peak and CS values of both major and minor principal fabric tensors decrease with increasing b values,while they increase with increasing b values for the intermediate principal fabric tensor.

关键词： Discrete element method Intermediate stress ratio Dilation Critical state Failure criterion

DCFNet:Discriminant Correlation Filters Network for Visual Tracking

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Journal of Computer Science & Technology 2024年第3期39卷 691-714页

作者：胡卫明王强高晋李兵 stephen Maybank State key Laboratory of Multimodal Artificial Intelligence Systems Institute of AutomationChinese Academy of Sciences Beijing 100190China Department of Computer Science and Information Systems Birkbeck CollegeLondon WC1E 7HXU.K.

CNN(convolutional neural network)based real time trackers usually do not carry out online network update in order to maintain rapid tracking *** inevitably influences the adaptability to changes in object *** filter based trackers can update the model parameters online in real *** this paper,we present an end-to-end lightweight network architecture,namely Discriminant Correlation Filter Network(DCFNet).A differentiable DCF(discriminant correlation filter)layer is incorporated into a Siamese network architecture in order to learn the convolutional features and the correlation filter *** correlation filter can be efficiently updated *** previous work,we introduced a joint scale-position space to the DCFNet,forming a scale DCFNet which carries out the predictions of object scale and position *** combine the scale DCFNet with the convolutional-deconvolutional network,learning both the high-level embedding space representations and the low-level fine-grained representations for *** adaptability of the fine-grained correlation analysis and the generalization capability of the semantic embedding are complementary for visual *** back-propagation is derived in the Fourier frequency domain throughout the entire work,preserving the efficiency of the *** evaluations on the OTB(Object Tracking Benchmark)and VOT(Visual Object Tracking Challenge)datasets demonstrate that the proposed trackers have fast speeds,while maintaining tracking accuracy.

关键词： correlation filter convolutional neural network(CNN) visual tracking