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Panhypopituitarism caused by a suprasellar germinoma: A case report
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作者 Jelena Roganovic Lea Saric +2 位作者 Silvije Segulja Ana Dordevic Mia Radosevic 《World Journal of Clinical Cases》 SCIE 2024年第10期1844-1850,共7页
BACKGROUND Suprasellar germinomas are rare intracranial tumors frequently associated with permanent endocrine disorders.We present the clinical picture,treatment,and complications of suprasellar germinoma at pediatric... BACKGROUND Suprasellar germinomas are rare intracranial tumors frequently associated with permanent endocrine disorders.We present the clinical picture,treatment,and complications of suprasellar germinoma at pediatric age which,besides being lifethreatening,has lifelong endocrinological consequences.CASE SUMMARY A 12-year-old female patient was presented having had intensive headaches for three weeks and visual disturbances for six months.An ophthalmological examination revealed bilateral papilledema and a marked loss of vision.Emergency brain magnetic resonance imaging(MRI)showed a suprasellar tumor,involving the infundibulum and the optic chiasm,extending to the third ventricle.Laboratory tests confirmed decreased levels of thyroxine,cortisol,gonadotropins,and insulin-like growth factor 1.Maximal tumor reduction was performed,and immunohistopathology established the diagnosis of suprasellar germinoma.MRI of the spine and cerebrospinal fluid cytology confirmed the localized disease.Adjuvant chemotherapy and radiotherapy were performed according to the SIOP CNS GCT II protocol.A post-treatment MRI showed no residual tumor,but pituitary function had not recovered.Three and a half years after the end of the treatment,the patient is in a complete remission,requiring hormonal replacement therapy,continuous education,and psychological support.CONCLUSION This complex case highlights the importance of timely diagnosis,a multidisciplinary approach,and close follow-up in children with suprasellar germinomas. 展开更多
关键词 GERMINOMA Germ cell tumor Suprasellar tumor HYPOPITUITARISM Management PEDIATRICS Case report
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Key Developments in Indian Irrigation Sector
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作者 Sabarna Roy 《Journal of Environmental Science and Engineering(A)》 2020年第5期184-187,共4页
The key developments in Indian Irrigation sector have been presented by briefly discussing the following topics:1.Present Indian Irrigation Challenges and Way Forward.2.Regulatory Interventions in Water Sector in Indi... The key developments in Indian Irrigation sector have been presented by briefly discussing the following topics:1.Present Indian Irrigation Challenges and Way Forward.2.Regulatory Interventions in Water Sector in India(Maharashtra’s Example).3.Roles and Activities of Maharashtra Water Resource Regulatory Authority(MWRRA).4.Major Achievements of MWRRA.5.Indian National Committee On Irrigation and Drainage(INCID).6.Irrigation,Command Area Development and Micro Irrigation in India.7.Flood Management and Its Measures.8.Capacity Building. 展开更多
关键词 IRRIGATION DEVELOPMENTS MWRRA INCID CWC water efficiency flood forecasting SUSTAINABILITY MICRO-IRRIGATION
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Why Flexibility Is a Must in China Business
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作者 Miguel Ataíde Coelho 《China's Foreign Trade》 2012年第2期93-93,共1页
Let me start by saying that it is always dangerous to make general assessments, as there will always be cases that point to another direction. Let me also state that I believe that flexibility is a must to doing busin... Let me start by saying that it is always dangerous to make general assessments, as there will always be cases that point to another direction. Let me also state that I believe that flexibility is a must to doing business in any part of the world. Therefore, my comments are always personal and on relative, average terms. The frequent changes in policies in regulations usually impact both 展开更多
关键词 活性 商业 中国
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Lessons in Development
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作者 Micheal Saeed Abudu 《ChinAfrica》 2020年第2期20-21,共2页
For over four decades China has implemented a wide range of economic reforms and strategies aimed at alleviating poverty and opening up the economy,the results of which are often dubbed an“economic miracle.”An im po... For over four decades China has implemented a wide range of economic reforms and strategies aimed at alleviating poverty and opening up the economy,the results of which are often dubbed an“economic miracle.”An im portant part of this econom ic growth has recently taken place in Chongli.A district located on the outer edge of Beijing,Chongli,in Zhangjiakou City,is surrounded by mountains and beautiful natural scenery. 展开更多
关键词 CHONG MOUNTAINS BEAUTIFUL
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Overview of priorities,threats,and challenges to biodiversity conservation in the southern Philippines 被引量:1
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作者 Angelo Rellama AGDUMA Francisco Gil GARCIA +9 位作者 Ma.Teodora CABASAN Jonald PIMENTEL Renee Jane ELE Meriam RUBIO Sedra MURRAY Bona Abigail HILARIO-HUSAIN Kier Celestial Dela CRUZ Sumaira ABDULLAH Shiela Mae BALASE Krizler Cejuela TANALGO 《Regional Sustainability》 2023年第2期203-213,共11页
Human activities have severely impacted on many species and ecosystems.Thus,understanding the local biodiversity situation is crucial for implementing effective biodiversity conservation interventions.Mindanao in the ... Human activities have severely impacted on many species and ecosystems.Thus,understanding the local biodiversity situation is crucial for implementing effective biodiversity conservation interventions.Mindanao in the southern Philippines is home to various unique species,particularly in its pristine ecosystems.However,the available biodiversity data for many terrestrial vertebrates and key areas remain incomplete.To address this issue,we synthesized published literature related to biodiversity from 2000 to 2022 in Mindanao.Moreover,this analysis used four key terrestrial vertebrates(amphibians,reptiles,birds,and mammals)in Mindanao as research objects.According to our findings,there was a significant and positive correlation between the number of biodiversity studies and species recorded.In terms of species richness,birds were the most recorded group(n=334 spp.),followed by reptiles(n=108 spp.),mammals(n=70 spp.),and amphibians(n=52 spp.).We also found that the number of endemic and threatened species varies geographically and across taxonomic groups.Yet,we discovered a significant disparity in the information available on biodiversity in different provinces of Mindanao.For example,the western provinces of Mindanao have had no record of biodiversity for more than two decades.Furthermore,we found that the changes in tree cover loss were consistent with biodiversity records,but this correlation is only significant for birds.Finally,we highlighted some critical threats and challenges to biodiversity,including deforestation,agricultural expansion,mining,and their impact on biodiversity conservation in Mindanao.Our findings suggested that biodiversity conservation should focus not only on areas with high levels of biodiversity but also on areas lacking biodiversity information.To do this,we call for strengthening collaboration among various institutions and digitizing and centralizing of information related to biodiversity.By gaining a deeper understanding of biodiversity in Mindanao,we can better and sustainably protect critical ecosystems in this region from the increasing threats posed by human activities. 展开更多
关键词 Biodiversity conservation Tree cover loss Mindanao Terrestrial vertebrates Endemic and threatened species
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Gene expression profiles of hepatic cell-type specific marker genes in progression of liver fibrosis 被引量:5
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作者 Yoshiyuki Takahara Mitsuo Takahashi +5 位作者 Hiroki Wagatsuma Fumihiko Yokoya Qing-Wei Zhang Mutsuyo Yamaguchi Hiroyuki Aburatani Norifumi Kawada 《World Journal of Gastroenterology》 SCIE CAS CSCD 2006年第40期6473-6499,共27页
AIM: To determine the gene expression profile data for the whole liver during development of dimethylni-trosamine (DMN)-induced hepatic fibrosis.METHODS: Marker genes were identified for different types of hepatic cel... AIM: To determine the gene expression profile data for the whole liver during development of dimethylni-trosamine (DMN)-induced hepatic fibrosis.METHODS: Marker genes were identified for different types of hepatic cells, including hepatic stellate cells (HSCs), Kupffer cells (including other inflammatory cells), and hepatocytes, using independent temporal DNA microarray data obtained from isolated hepatic cells. RESULTS: The cell-type analysis of gene expression gave several key results and led to formation of three hypotheses: (1) changes in the expression of HSC-specific marker genes during fibrosis were similar to gene expression data in in vitro cultured HSCs, suggesting a major role of the self-activating characteristics of HSCs in formation of fibrosis; (2) expression of mast cell-specific marker genes reached a peak during liver fibrosis, suggesting a possible role of mast cells in formation of fibrosis; and (3) abnormal expression of hepatocyte-specific marker genes was found across several metabolic pathways during fibrosis, including sulfur-containing amino acid metabolism, fatty acid metabolism, and drug metabolism, suggesting a mechanistic relationship between these abnormalities and symptoms of liver fibrosis. CONCLUSION: Analysis of marker genes for specific hepatic cell types can identify the key aspects of fibro-genesis. Sequential activation of inflammatory cells and the self-supporting properties of HSCs play an important role in development of fibrosis. 展开更多
关键词 基因表达 肝疾病 病理 治疗 临床
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Seismic risk evaluation for a planning mountain tunnel using improved analytical hierarchy process based on extension theory 被引量:3
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作者 XU Jing-song XU Hua +2 位作者 SUN Run-fang ZHAO Xiang-wei CHENG Yin 《Journal of Mountain Science》 SCIE CSCD 2020年第1期244-260,共17页
Seismic risk evaluation(SRE) in early stages(e.g., project planning and preliminary design)for a mountain tunnel located in seismic areas has the same importance as that in final stages(e.g.,performance-based design, ... Seismic risk evaluation(SRE) in early stages(e.g., project planning and preliminary design)for a mountain tunnel located in seismic areas has the same importance as that in final stages(e.g.,performance-based design, structural analysis, and optimization). SRE for planning mountain tunnels bridges the gap between the planning on the macro level and the design/analysis on the micro level regarding the risk management of infrastructural systems. A transition from subjective or qualitative description to objective or quantitative quantification of seismic risk is aimed to improve the seismic behavior of the mountain tunnel and thus reduce the associated seismic risk. A new method of systematic SRE for the planning mountain tunnel was presented herein. The method employs extension theory(ET)and an ET-based improved analytical hierarchy process. Additionally, a new risk-classification criterion is proposed to classify and quantify the seismic risk for a planning mountain tunnel. This SRE method is applied to a mountain tunnel in southwest China, using the extension model based on matter element theory and dependent function operation.The reasonability and flexibility of the SRE method for application to the mountain tunnel are illustrated.According to different seismic risk levels and classification criteria, methods and measures for improving the seismic design are proposed, which can reduce the seismic risk and provide a frame of reference for elaborate seismic design. 展开更多
关键词 Seismic risk evaluation Mountain tunnel Extension theory Analytical hierarchy process Classification criterion
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关于作用在离心压缩机上的流体激振力以及由此产生的转子振动特性综述 被引量:13
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作者 詹姆斯 弗雷德·马修 马克 《风机技术》 2017年第1期43-64,共22页
引起离心压缩机转子非同步受迫振动的来源有许多,其中较典型的因素包括产生于压缩机气体通道中的气动力学现象。例如叶轮失速、扩压器失速(有叶片和无叶片)以及由于叶轮和扩压器不对中而产生的气流不稳定等。通常这些现象的唯一表现形... 引起离心压缩机转子非同步受迫振动的来源有许多,其中较典型的因素包括产生于压缩机气体通道中的气动力学现象。例如叶轮失速、扩压器失速(有叶片和无叶片)以及由于叶轮和扩压器不对中而产生的气流不稳定等。通常这些现象的唯一表现形式就是转子的振动信号。本文对可能引起离心压缩机转子非同步振动的诸多因素进行了回顾,并且针对每个因素的背景信息、流场细节以及其它可能存在的激励源等方面,逐一进行了描述,并在适当的情况下运用CFD技术对流场予以分析。综述中还例举了可以用来验证上述现象的空气压力的监测数据以及可以证明这些现象的存在的转子振动数据。这些数据均来自于对实际设备的的监测,例如频率和振幅等特征参数。 展开更多
关键词 离心压缩机 流体激振力 转子 振动特性 综述 监测数据 CFD技术 受迫振动
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Requirements for implementation of artificial intelligence in the practice of gastrointestinal pathology 被引量:1
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作者 Hiroshi Yoshida Tomoharu Kiyuna 《World Journal of Gastroenterology》 SCIE CAS 2021年第21期2818-2833,共16页
Tremendous advances in artificial intelligence(AI)in medical image analysis have been achieved in recent years.The integration of AI is expected to cause a revolution in various areas of medicine,including gastrointes... Tremendous advances in artificial intelligence(AI)in medical image analysis have been achieved in recent years.The integration of AI is expected to cause a revolution in various areas of medicine,including gastrointestinal(GI)pathology.Currently,deep learning algorithms have shown promising benefits in areas of diagnostic histopathology,such as tumor identification,classification,prognosis prediction,and biomarker/genetic alteration prediction.While AI cannot substitute pathologists,carefully constructed AI applications may increase workforce productivity and diagnostic accuracy in pathology practice.Regardless of these promising advances,unlike the areas of radiology or cardiology imaging,no histopathology-based AI application has been approved by a regulatory authority or for public reimbursement.Thus,implying that there are still some obstacles to be overcome before AI applications can be safely and effectively implemented in real-life pathology practice.The challenges have been identified at different stages of the development process,such as needs identification,data curation,model development,validation,regulation,modification of daily workflow,and cost-effectiveness balance.The aim of this review is to present challenges in the process of AI development,validation,and regulation that should be overcome for its implementation in real-life GI pathology practice. 展开更多
关键词 Artificial intelligence Deep learning Digital image analysis Digital pathology Clinical implementation Gastrointestinal cancer
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Delphi-Based Planning Approach in the Maritime Transport Chain 被引量:1
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作者 Raft Elbert Fabian Walter Roman Grig 《Journal of Shipping and Ocean Engineering》 2012年第3期175-181,共7页
关键词 规划问题 运输链 DELPHI 海上 集装箱运输 市场增长 集装箱转运 信息不对称
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Porcine Placenta Extract Reduced Wrinkle Formation by Potentiating Epidermal Hydration 被引量:1
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作者 Akihiro Aioi Ryuta Muromoto +3 位作者 Sho Mogami Megumi Nishikawa Shigeyuki Ogawa Tadashi Matsuda 《Journal of Cosmetics, Dermatological Sciences and Applications》 2021年第2期101-109,共9页
<strong>Background:</strong> Placenta extract is used as an alternative medicine especially in Asian countries as it is a rich reservoir of diverse bioactive molecules. The effects of placenta extract on s... <strong>Background:</strong> Placenta extract is used as an alternative medicine especially in Asian countries as it is a rich reservoir of diverse bioactive molecules. The effects of placenta extract on skin conditions have been previously reported, however, the mechanism underlying for reduced wrinkle formation remains unclear. <strong>Objective:</strong> The primary objective of this study was to determine whether the continuous application of porcine placenta extract (PPE) alleviates wrinkle formation in humans and explore the underlying mechanism. <strong>Methods:</strong> Wrinkle formation, skin hydration, and skin elasticity were measured in 15 volunteers at weeks 0 and 6 after continuous application of a gel containing PPE. The production of type I collagen and hyaluronic acid from fibroblasts and keratinocytes, respectively, were measured using ELISA. Expression levels of ceramide synthase 3 (CERS3), filaggrin (FLG), transglutaminase 1 (TGM1), and kallikrein-7 (KLK7) were evaluated by quantitative real-time PCR. <strong>Results:</strong> The wrinkle index was significantly reduced to 72.1% after a 6-week of applying the PPE gel, along with a significant increase in skin hydration to 126.5%. Type I collagen production from fibroblasts was enhanced slightly but significantly following treatment with PPE. PPE accelerated the expression of CERS3 (1.85-fold), FLG (1.35-fold), TGM1 (1.76-fold), and KLK7 (1.62-fold). <strong>Conclusion:</strong> Treatment with PPE alleviates wrinkle formation and simultaneously enhances skin hydration, which is induced via the accelerated expression of moisturizing-related proteins. These findings suggest that PPE is effective for combating dryness-induced wrinkle formation. 展开更多
关键词 Porcine Placenta Wrinkle Formation Moisturizing-Related Proteins Keratinocyte Differentiation
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Industrial Progress:New Energy-Efficient Absorbents for the CO_(2) Separation from Natural Gas,Syngas and Flue Gas 被引量:1
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作者 Jorn Rolker Matthias Seiler 《Advances in Chemical Engineering and Science》 2011年第4期280-288,共9页
The CO2 separation from natural gas, syngas or flue gas represents an important industrial field of applications. An economic and energy-efficient CO2 separation from these gas streams is a prerequisite for sustainabl... The CO2 separation from natural gas, syngas or flue gas represents an important industrial field of applications. An economic and energy-efficient CO2 separation from these gas streams is a prerequisite for sustainable industry contributions to the megatrends resource efficiency and globalization of technologies. One way of reducing operational expenditure for these separation processes is the development of better performing CO2 absorbents. Although a number of absorbents for the separation of CO2 from process gas streams exist, the need for the development of CO2 absorbents with an improved absorption performance, less corrosion and foaming, no nitrosamine formation, lower energy requirement and therefore less operational expenditure remains. Recent industrial activities have led to the development of novel high-performance CO2 scrubbing agents that can be employed in numerous industrial processes such as natural gas treatment, purification of syngas and the scrubbing of flue gas. The objective of this paper is to introduce these new high-performance scrubbing agents and to compare their performance with other state-of-the-art absorbents. It turned out, that the evaluated absorbents offer high cyclic capacities in the range of 2.4 to 2.6 mol CO2/kg absorbent and low absorption enthalpies (–30 kJ/mol) allowing for distinctive savings in the regeneration energy of the absorbent. Calculations with the modified Kremser model resulted in a reduction of the specific reboiler heat duty of 55%. Furthermore, the absorbents are less corrosive than standard amines as indicated by the measured corrosion rates of 0.21 mm/y versus 1.18 mm/y for a piperazine/methyldiethanolamine mixture. Based on new experimental results it is shown how substantial savings in operational and capital expenditure can be realized due to favorable absorbent properties. The novel high-performance CO2 system solutions meet recent industrial absorbent requirements and allow for more efficient or new CO2 separation processes. 展开更多
关键词 ABSORBENT CO_(2) Energy Efficiency Sustainability Operational Expenditure SEPARATION Capture
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EXAFS Studies on Local Atomic Structure in the Amorphous Mg_(65)Cu_(25)Gd_(10) Alloy
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作者 李国强 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2011年第1期98-101,共4页
Local atomic structures of an amorphous Mg65Cu25Gd10 alloy and the structural changes by thermal annealing have been studied by extended X-ray absorption fine structure (EXAFS). The correlation between structural ch... Local atomic structures of an amorphous Mg65Cu25Gd10 alloy and the structural changes by thermal annealing have been studied by extended X-ray absorption fine structure (EXAFS). The correlation between structural changes and mechanical properties for the Mg65Cu25Gd10 alloy has also been discussed. Results showed that Cu atoms around Gd in Mg65Cu25Gd10 lost rapidly during annealing , resulting in the segregation of Cu atoms. The coordination number NGd-Mg of Mg65Cu25Gd10 annealed at 373 K first diminished and then augmented with the increase of annealing time. The formation of polyhedral short-range order unit with coordination number of nearly 12 around Gd atoms is in favor of the improvement of mechanical properties. The chemical short-range order, not topological short-range order in the amorphous Mg65Cu25Gd10 alloy had obvious changes during annealing. 展开更多
关键词 magnesium alloy amorphous alloy SHORT-RANGE EXAFS mechanical properties ANNEALING
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把食品配料技术用于食品接触塑材(摘要)
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作者 Danisco A/S 《中国食品添加剂》 CAS 北大核心 2009年第S1期17-18,共2页
关键词 食品质量 生物技术 食品配料 接触 安全问题 配料技术 增塑剂 欧盟 品牌 保护
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A review of the day-ahead natural gas consumption in Denmark:starting point towards forecasting accuracy improvement
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作者 Orhan AltuğKarabiber George Xydis 《International Journal of Coal Science & Technology》 EI CAS CSCD 2021年第1期1-22,共22页
Natural gas consumption forecasting is crucial for transmission system operators,distribution system operators,traders,and other players in the market.This work collects natural gas forecasting scientific works in acc... Natural gas consumption forecasting is crucial for transmission system operators,distribution system operators,traders,and other players in the market.This work collects natural gas forecasting scientific works in accordance with the forecasting tool used by Energinet,the Danish transmission system operator.The work provides an analytical description on the long-term stability and security of the natural gas transmission system in Denmark.This work offers a detailed scientific directory on natural gas forecasting,presenting the so far vaguely described market in a more structured manner.The paper was focused on presenting the latest findings on identifying the selection each time of the appropriate prognostic model for each application based on:①the option for supporting double seasonality,②various exogenous variables,③suitability for day-ahead forecasting,and④ease of use and all these versus Energinet’s current model. 展开更多
关键词 Natural gas Forecasting Natural gas supply chain Gas infrastructure
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Real-Time Network Intrusion Prevention System Using Incremental Feature Generation
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作者 Yeongje Uhm Wooguil Pak 《Computers, Materials & Continua》 SCIE EI 2022年第1期1631-1648,共18页
Security measures are urgently required to mitigate the recent rapid increase in network security attacks.Although methods employing machine learning have been researched and developed to detect various network attack... Security measures are urgently required to mitigate the recent rapid increase in network security attacks.Although methods employing machine learning have been researched and developed to detect various network attacks effectively,these are passive approaches that cannot protect the network from attacks,but detect them after the end of the session.Since such passive approaches cannot provide fundamental security solutions,we propose an active approach that can prevent further damage by detecting and blocking attacks in real time before the session ends.The proposed technology uses a two-level classifier structure:the first-stage classifier supports real-time classification,and the second-stage classifier supports accurate classification.Thus,the proposed approach can be used to determine whether an attack has occurred with high accuracy,even under heavy traffic.Through extensive evaluation,we confirm that our approach can provide a high detection rate in real time.Furthermore,because the proposed approach is fast,light,and easy to implement,it can be adopted in most existing network security equipment.Finally,we hope to mitigate the limitations of existing security systems,and expect to keep networks faster and safer from the increasing number of cyber-attacks. 展开更多
关键词 Network intrusion detection network intrusion prevention REALTIME two-level classifier
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Raman spectroscopy for the diagnosis of unlabeled and unstained histopathological tissue specimens
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作者 Haruo Ikeda Hiroaki Ito +7 位作者 Muneaki Hikita Noriko Yamaguchi Naoyuki Uragami Noboru Yokoyama Yuko Hirota Miki Kushima Yoichi Ajioka Haruhiro Inoue 《World Journal of Gastrointestinal Oncology》 SCIE CAS 2018年第11期439-448,共10页
AIM To investigate the possibility of diagnosing gastric cancer from an unstained pathological tissue using Raman spectroscopy, and to compare the findings to those obtained with conventional histopathology. METHODS W... AIM To investigate the possibility of diagnosing gastric cancer from an unstained pathological tissue using Raman spectroscopy, and to compare the findings to those obtained with conventional histopathology. METHODS We produced two consecutive tissue specimens from areas with and without cancer lesions in the surgically resected stomach of a patient with gastric cancer. One of the two tissue specimens was stained with hematoxylin and eosin and used as a reference for laser irradiation positioning by the spectroscopic method. The other specimen was left unstained and used for Raman spectroscopy analysis. RESULTS A significant Raman scattering spectrum could be obtained at all measurement points. Raman scattering spectrum intensities of 725 cm^(-1) and 782 cm^(-1), are associated with the nucleotides adenine and cytosine, respectively. The Raman scattering spectrum intensity ratios of 782 cm^(-1)/620 cm^(-1), 782 cm^(-1)/756 cm^(-1), 782 cm^(-1)/1250 cm^(-1), and 782 cm^(-1)/1263 cm^(-1) in the gastric adenocarcinoma tissue were significantly higher than those in the normal stomach tissue.CONCLUSION The results of this preliminary experiment suggest the feasibility of our spectroscopic method as a diagnostic tool for gastric cancer using unstained pathological specimens. 展开更多
关键词 LABEL-FREE analysis RAMAN spectroscopy HISTOPATHOLOGICAL examination GASTRIC cancer
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Analysis and Characterization of Normally-Off Gallium Nitride High Electron Mobility Transistors
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作者 Shahzaib Anwar Sardar Muhammad Gulfam +3 位作者 Bilal Muhammad Syed Junaid Nawaz Khursheed Aurangzeb Mohammad Kaleem 《Computers, Materials & Continua》 SCIE EI 2021年第10期1021-1037,共17页
High electron mobility transistor(HEMT)based on gallium nitride(GaN)is one of the most promising candidates for the future generation of high frequencies and high-power electronic applications.This research work aims ... High electron mobility transistor(HEMT)based on gallium nitride(GaN)is one of the most promising candidates for the future generation of high frequencies and high-power electronic applications.This research work aims at designing and characterization of enhancement-mode or normally-off GaN HEMT.The impact of variations in gate length,mole concentration,barrier variations and other important design parameters on the performance of normally-off GaN HEMT is thoroughly investigated.An increase in the gate length causes a decrease in the drain current and transconductance,while an increase in drain current and transconductance can be achieved by increasing the concentration of aluminium(Al).For Al mole fractions of 23%,25%,and 27%,within Al gallium nitride(AlGaN)barrier,the GaN HEMT devices provide a maximum drain current of 347,408 and 474 mA/μm and a transconductance of 19,20.2,21.5 mS/μm,respectively.Whereas,for Al mole fraction of 10%and 15%,within AlGaN buffer,these devices are observed to provide a drain current of 329 and 283 mA/μm,respectively.Furthermore,for a gate length of 2.4,3.4,and 4.4μm,the device is observed to exhibit a maximum drain current of 272,235,and 221 mA/μm and the transconductance of 16.2,14,and 12.3 mS/μm,respectively.It is established that a maximum drain current of 997 mA/μm can be achieved with an Al concentration of 23%,and the device exhibits a steady drain current with enhanced transconductance.These observations demonstrate tremendous potential for two-dimensional electron gas(2DEG)for securing of the normally-off mode operation.A suitable setting of gate length and other design parameters is critical in preserving the normally-off mode operation while also enhancing the critical performance parameters at the same time.Due to the normallyon depletion-mode nature of GaN HEMT,it is usually not considered as suitable for high power levels,frequencies,and temperature.In such settings,a negative bias is required to enter the blocking condition;however,in the before-mentioned normally-off devices,the negative bias can be avoided and the channel can be depleted without applying a negative bias. 展开更多
关键词 High electron mobility GAN HEMT bipolar transistors gallium nitride HETEROJUNCTIONS MOS devices
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Polyurethane Coating and Lining on Ductile Iron Pipes
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作者 Sabarna Roy 《Journal of Environmental Science and Engineering(B)》 2020年第5期182-188,共7页
In this technical paper,we will discuss polyurethane linings and coatings to ductile iron pipe for transporting corrosive and abrasive fluids in a sub soil,that is extremely corrosive in nature.The capabilities of ECL... In this technical paper,we will discuss polyurethane linings and coatings to ductile iron pipe for transporting corrosive and abrasive fluids in a sub soil,that is extremely corrosive in nature.The capabilities of ECL(Electrosteel Castings Limited)in this regard will be discussed. 展开更多
关键词 Polyurethane LINING coating ECL ISI(Indian Standards Institution) test certificates performance tests PROVISION specification
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Odor-Active Volatile Compounds from the Gonads of the Sea Urchin <i>Mesocentrotus nudus</i>in the Wild in Miyagi Prefecture, Tohoku, Japan
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作者 Yoichi Sato Satomi Takagi +1 位作者 Eri Inomata Yukio Agatsuma 《Food and Nutrition Sciences》 2019年第7期860-875,共16页
Background and Aims: Mesocentrotus nudus is commercially harvested from shallow rocky bottoms in northern Japan. The gonads are targeted as an edible product. The objective of this study was to identify odor-active vo... Background and Aims: Mesocentrotus nudus is commercially harvested from shallow rocky bottoms in northern Japan. The gonads are targeted as an edible product. The objective of this study was to identify odor-active volatile organic compounds (VOCs) from the gonads of adult M. nudus collected at a fishing ground in Miyagi Prefecture, Tohoku, Japan. Methods and Results: Gas chromatography-mass spectrometry analysis and gas chromatography-sniffing techniques identified 42 compounds categorized as alcohols, aldehydes, aromatic hydrocarbons, esters, halomethanes, hydrocarbons, ketones, sulfur-containing compounds, and nitrogen-containing compounds. GC-sniffing analysis characterized four compounds with preferable odors of sea urchin gonads;limonene, propyl acetate, acetone, dibromochloromethane. On the other hand, the analysis characterized three compounds with unpreferable odors;methyl mercaptane, dimethyl sulfide, and s-methyl thioacetate. Several VOCs from the gonads were derived from seaweeds, terrestrial plants, and fish flesh as food because M. nudus is omnivorous. Conclusion: This is the first study to identify VOCs from edible sea urchin gonads in the wild in Japan. These VOC data comprise a typical standard in order to evaluate a higher quality of sea urchin gonads. 展开更多
关键词 Sea URCHIN Mesocentrotus nudus GONAD Flavor GC/MS SNIFFING Analysis
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