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Intrahepatic distribution of hepatitis B virus antigens in patients with and without hepatocellular carcinoma

World Journal of Gastroenterology 2016年第12期22卷 3404-3411页

作者： Parham Safaie Mugilan Poongkunran Ping-Ping Kuang Asad Javaid Carl Jacobs Rebecca Pohlmann imad nasser Daryl TY Lau Liver Center Division of Gastroenterology Department of Medicine Beth Israel Deaconess Medical Center Harvard Medical School Department of Pathology Beth Israel Deaconess Medical Center Harvard Medical School

AIM: To study the intrahepatic expression of hepatitis B surface antigen (HBsAg) and hepatitis B core antigen (HBcAg) in chronic hepatitis B patients with and without hepatocellular ***: A total of 33 chronic hepatitis B patients (mean age of 40.3 ± 2.5 years), comprising of 14 HBeAg positive and 19 HBeAg negative patients; and 13 patients with hepatitis B virus related hepatocellular carcinoma (mean age of 49.6 ± 4.7 years), were included in our study. Immunohistochemical staining for HBcAg and HBsAg was done using standard streptavidin-biotin-immunoperoxidase technique on paraffin-embedded liver biopsies. The HBcAg and HBsAg staining distributions and patterns were described according to a modified classification ***: Compared to the HBeAg negative patients, the HBeAg positive patients were younger, had higher mean HBV DNA and alanine transaminases levels. All the HBeAg positive patients had intrahepatic HBcAg staining; predominantly with “diffuse” distribution (79%) and “mixed cytoplasmic/nuclear” pattern (79%). In comparison, only 5% of the HBeAg-negative patients had intrahepatic HBcAg staining. However, the intrahepatic HBsAg staining has wider distribution among the HBeAg negative patients, namely; majority of the HBeAg negative cases had “patchy” HBsAg distribution compared to “rare” distribution among the HBeAg positive cases. All but one patient with HCC were HBeAg negative with either undetectable HBV DNA or very low level of viremia. Intrahepatic HBcAg and HBsAg were seen in 13 (100%) and 10 (77%) of the HCC patients respectively. Interestingly, among the 9 HCC patients on anti-viral therapy with suppressed HBV DNA, HBcAg and HBsAg were detected in tumor tissues but not the adjacent liver in 4 (44%) and 1 (11%) patient ***: Isolated intrahepatic HBcAg and HBsAg can be present in tumors of patients with suppressed HBV DNA on antivir

关键词： Hepatitis B virus Chronic hepatitis B Hepatocellular carcinoma Hepatitis B core antigen Hepatitis B surface antigen

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Refraction characteristics of phononic crystals

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Acta Mechanica Sinica 2015年第4期31卷 481-493页

作者： Sia Nemat-nasser Department of Mechanical and Aerospace Engineering University of California

Some of the most interesting refraction prop- erties of phononic crystals are revealed by examining the anti-plane shear waves in doubly periodic elastic composites with unit cells containing rectangular and/or elliptical multi- inclusions. The corresponding band structure, group velocity, and energy-flux vector are calculated using a powerful mixed variational method that accurately and efficiently yields all the field quantities over multiple frequency pass-bands. The background matrix and the inclusions can be anisotropic, each having distinct elastic moduli and mass densities. Equifrequency contours and energy-flux vectors are read- ily calculated as functions of the wave-vector components. By superimposing the energy-flux vectors on equifrequency contours in the plane of the wave-vector components, and supplementing this with a three-dimensional graph of the corresponding frequency surface, a wealth of information is extracted essentially at a glance. This way it is shown that a composite with even a simple square unit cell con- taining a central circular inclusion can display negative or positive energy and phase velocity refractions, or simply performs a harmonic vibration （standing wave）, depending on the frequency and the wave-vector. Moreover, that the same composite when interfaced with a suitable homoge- neous solid can display：（1） negative refraction with negative phase velocity refraction; （2） negative refraction with pos- itive phase velocity refraction; （3） positive refraction with negative phase velocity refraction; （4） positive refraction with positive phase velocity refraction; or even （5） completereflection with no energy transmission, depending on the fre- quency, and direction and the wavelength of the plane-wave that is incident from the homogeneous solid to the interface. For elliptical and rectangular inclusion geometries, analyti- cal expressions are given for the key calculation quantities. Expressions for displacement, velocity, linear m

关键词： Doubly periodic composites - Phononiccrystals Band structure Group and energy-flux vectors

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Delay-Constrained Optimized Packet Aggregation in High-Speed Wireless Networks

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Journal of Computer Science & Technology 2013年第3期28卷 525-539页

作者： Peyman Teymoori nasser Yazdani School of Electrical and Computer Engineering University College of Engineering University of Tehran School of Computer Science Institute for Research in Fundamental Sciences

High-speed wireless networks such as IEEE 802.11n have been introduced based on IEEE 802.11 to meet the growing demand for high-throughput and multimedia applications. It is known that the medium access control （MAC） efficiency of IEEE 802.11 decreases with increasing the physical rate. To improve efficiency, few solutions have been proposed such as Aggregation to concatenate a number of packets into a larger frame and send it at once to reduce the protocol overhead. Since transmitting larger frames eventuates to dramatic delay and jitter increase in other nodes, bounding the maxi- mum aggregated frame size is important to satisfy delay requirements of especially multimedia applications. In this paper, we propose a scheme called Optimized Packet Aggregation （OPA） which models the network by constrained convex optimization to obtain the optimal aggregation size of each node regarding to delay constraints of other nodes. OPA attains proportionally fair sharing of the channel while satisfying delay constrains. Furthermore, reaching the optimal point is guaranteed in OPA with low complexity. Simulation results show that OPA can successfully bound delay and meet the requirements of nodes with only an insignificant throughput penalty due to limiting the aggregation size even in dynamic conditions.

关键词： high-speed wireless network delay requirement aggregation convex optimization

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A stochastic based approach for a new site classification method:application to the Algerian seismic code

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Earthquake Engineering and Engineering Vibration 2015年第4期14卷 663-681页

作者： Mohamed Beneldjouzi nasser Laouami Civil Engineering Faculty University of Sciences and Technology Houari Boumediene Earthquake Engineering Applied Research Center (CGS)

Building codes have widely considered the shear wave velocity to make a reliable subsoil seismic classification, based on the knowledge of the mechanical properties of material deposits down to bedrock. This approach has limitations because geophysical data are often very expensive to obtain. Recently, other alternatives have been proposed based on measurements of background noise and estimation of the H/V amplification curve. However, the use of this technique needs a regulatory framework before it can become a realistic site classification procedure. This paper proposes a new formulation for characterizing design sites in accordance with the Algerian seismic building code (RPA99/ver.2003), through transfer functions, by following a stochastic approach combined to a statistical study. For each soil type, the deterministic calculation of the average transfer function is performed over a wide sample of 1-D soil profiles, where the average shear wave (S-W) velocity, Vs, in soil layers is simulated using random field theory. Average transfer functions are also used to calculate average site factors and normalized acceleration response spectra to highlight the amplification potential of each site type, since frequency content of the transfer function is significantly similar to that of the H/V amplification curve. Comparison is done with the RPA99/ver.2003 and Eurocode8 (EC8) design response spectra, respectively. In the absence of geophysical data, the proposed classification approach together with micro-tremor measures can be used toward a better soil classification.

关键词： random field transfer function soil classification RPA99/ ver. 2003 EC8 site factor response spectrum

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Joint simulation of cross-correlated ore grades and geological domains:an application to mineral resource modeling

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Frontiers of Earth Science 2023年第2期17卷 417-436页

作者： nasser MADANI Mohammad MALEKI School of Mining and Geosciences Nazarbayev UniversityAstana 010000Kazakhstan Department of Metallurgical and Mining Engineering Universidad Católica del NorteAntofagasta 1270709Chile

Spatial modeling of ore grades is frequently impacted by the local variation in geological domains such as lithological characteristics,rock types,and geological *** this information may lead to biased results in the final ore grade block model,subsequently impacting the downstream processes in a mining chain *** the current practice of ore body evaluation,which is known as stochastic cascade/hierarchical geostatistical modeling,the geological domain is first characterized,and then,within the geological model,the ore grades of interest are *** practice may be unrealistic in the case when the variability in ore grade across the boundary is gradual,following a smooth *** reproduce such characteristics,the cross dependence that exists between the ore grade and geological formations is considered in the conventional joint simulation between continuous and categorical ***,when using this approach,only one ore variable is considered,and its relationship with other ore grades that may be available at the sample location is *** this study,an alternative approach to jointly model two cross-correlated ore grades and one categorical variable(i.e.,geological domains)with soft contact relationships that exist among the geological domains is *** statistical and geostatistical tools are provided for variogram inference,Gibbs sampling,and conditional *** algorithm is also tested by applying it to a Cu deposit,where the geological formations are managed by the local and spatial distribution of two cross-correlated ore grades,Cu and Au,throughout the *** results show that the proposed algorithm outperforms other geostatistical techniques in terms of global and local reproduction of statistical parameters.

关键词： geostatistical simulation categorical variable continuous variable geological domain variogram inference

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FRACTIONAL HALANAY INEQUALITY AND APPLICATION IN NEURAL NETWORK THEORY

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Acta Mathematica Scientia 2019年第6期39卷 1605-1618页

作者： nasser-eddine TATAR King Fahd University of Petroleum and Minerals Department of Mathematics and Statistics

The (integer order) Halanay inequality with distributed delays is extended to the fractional order case. It is proved that solutions decay to zero as a Mittag-Leffler function as time goes to infinity provided that the delay feedback are bounded by similar *** application to a problem arising in neural network theory is provided showing that the equilibrium is Mittag-Leffler stable.

关键词： Hopfield neural network Mittag-Leffler stability Caputo fractional derivative fractional Halanay inequality

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Post-bulbar duodenal ulcer with anterior perforation with kissing ulcer and duodenocaval fistula:A case report and review of literature

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World Journal of Clinical Cases 2022年第25期10卷 9071-9077页

作者： nasser Alzerwi Department of Surgery College of MedicineMajmaah UniversityRiyadh 66RiyadhSaudi Arabia

BACKGROUND A post-bulbar duodenal ulcer(PBDU)is an ulcer in the duodenum that is distal to the duodenal *** may coexist with a synchronous posterior ulcer in rare occurrences,resulting in a kissing ulcer(KU).Duodenocaval fistula(DCF)is another uncommon but potentially fatal complication related to *** is limited knowledge of the scenarios in which PBDU is complicated by KU and DCF *** SUMMARY A 22-year-old man was admitted to the emergency department with abdominal pain,stiffness,and *** X-ray showed pneumoperitoneum,suggesting a perforated *** revealed a KU with anterior perforation and a *** Kocherization,venorrahphy was used to control caval *** to the critical condition of the patient,only primary duodenorrahphy with gastrojejunostomy was performed as a damage control ***,later,the patient developed obstructive jaundice and leakage,and two additional jejunal perforations were *** to the poor condition of the duodenum and the involvement of the ampulla in the posterior ulcer,neither primary repair nor pancreatic-free duodenectomy and ampull-oplasty/ampullary reimplantation were considered viable;therefore,an emergency pancreaticoduodenectomy was performed,along with resection and anastomosis of the two jejunal *** patient had a smooth recovery after surgery and was discharged after 27 *** The timely diagnosis of PBDU and radical surgery can aid in the smooth recovery of patients,even in the most complex cases.

关键词： Duodenal ulcer Duodenocaval fistula Kissing ulcer Emergency Whipple’s surgery Case report

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CD4+ T cell responses in hepatitis C virus infection

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World Journal of Gastroenterology 2007年第36期13卷 4831-4838页

作者： nasser Semmo Paul Klenerman Department of Medicine II University Hospital Freiburg Hugstetter Strasse 5579106 Freiburg Germany Nuffield Department of Clinical Medicine University of Oxford The Peter Medawar Building for Pathogen Research South Parks RoadOxford OX1 3SY United Kingdom

Hepatitis C virus (HCV) infection is a major cause of liver damage, with virus-induced end-stage disease such as liver cirrhosis and hepatocellular carcinoma resulting in a high rate of morbidity and mortality worldwide. Evidence that CD4+ T cell responses to HCV play an important role in the outcome of acute infection has been shown in several studies. However, the mechanisms behind viral persistence and the failure of CD4+ T cell responses to contain virus are poorly understood. During chronic HCV infection, HCV-specific CD4+ T cell responses are rela- tively weak or absent whereas in resolved infection these responses are vigorous and multispecific. Persons with a T-helper type I profile, which promotes cellular effec- tor mechanisms are thought to be more likely to experi- ence viral clearance, but the overall role of these cells in the immunopathogenesis of chronic liver disease is not known. To define this, much more data is required on the function and specificity of virus-specific CD4+ T cells, especially in the early phases of acute disease and in the liver during chronic infection. The role and possible mechanisms of action of CD4+ T cell responses in deter- mining the outcome of acute and chronic HCV infection will be discussed in this review.

关键词： Hepatitis C virus CD4 T cells HLA class Ⅱ Immune responses Cytokines Interleukin 2 Proliferation Escape Exhaustion

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A framework for an integrated unified modeling language

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Frontiers of Information Technology & Electronic Engineering 2016年第2期17卷 143-159页

作者： Mohammad ALSHAYEB nasser KHASHAN Sajjad MAHMOOD Information and Computer Science Department King Fahd University of Petroleum and Minerals

The unified modeling language(UML) is one of the most commonly used modeling languages in the software *** simplifies the complex process of design by providing a set of graphical notations,which helps express the objectoriented analysis and design of software *** UML is applicable to different types of systems,domains,methods,and processes,it cannot express certain problem domain ***,many extensions to UML have been *** this paper,we propose a framework for integrating the UML extensions and then use the framework to propose an integrated unified modeling language-graphical(iUML-g) ***-g integrates the existing UML extensions into one integrated *** includes an integrated diagram for UML class,sequence,and use case *** proposed approach is evaluated using a case *** proposed iUML-g is capable of modeling systems that use different domains.

关键词： Unified modeling language (UML) Integration Modeling System analysis and design

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Optimal operation of energy at hydrothermal power plants by simultaneous minimization of pollution and costs using improved ABC algorithm

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Frontiers in Energy 2015年第4期9卷 426-432页

作者： Homayoun EBRAHIMIAN Bahman TAHERI nasser YOUSEFI Department of Engineering Ardabil Branch Islamic Azad University Ardabil 0451 Iran Young Researchers and Elite Club Ardabil Branch Islamic Azad University Ardabil 0451 Iran

The aim of this paper is simultaneous mini- mization of hydrothermal units to reach the best solution by employing an improved artificial bee colony （ABC） algorithm in a multi-objective function consisting of economic dispatch （ED） considering the valve-point effect and pollution function in power systems in view of the hot water of the hydro system. In this type of optimization problem, all practical constraints of units were taken into account as much as possible in order to comply with the reality. These constraints include the maximum and minimum output power of units, the constraints caused by the balance between supply and demand, the impact of pollution, water balance, uneven production curve con- sidering the valve-point effect and system losses. The proposed algorithm is applied on the studied system, and the obtained results indifferent operating conditions are analyzed. To investigate in various operating conditions, different load profiles in 12 h are taken into account. The obtained results are compared with those of the other methods including the genetfc algorithm （GA）, the Basu technique, and the improved genetic algorithm. Fast convergence is one of this improved algorithm features.

关键词： practical constraints of units pollution func-tion inlet steam valve up-ramp rate of units improvedABC algorithm

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