bluuebunny/crossref_metadata_2025 huggingface dataset:
Negative External Cost Computing Model for Noise of China’s High-speed Railway and its Verification and Trend Analysis
Authors: Xuan Xiaomei
Published: May 2021

The purpose of this paper is to calculate the external noise cost of China’s high-speed railway and forecast its future trend. Firstly, the unit value transfer method after correction is selected as a method of calculation. Secondly, the noise cost calculation model of China’s high-speed railway is established by introducing the correction factors such as GDP-PPP, population density ratio and CPI ratio. At last, the external noise cost since the opening of high-speed railway is calculated. The model validation results show that although the average external noise cost of high-speed railway increases year by year, it does not increase significantly. This is not only related to economic growth and improvement of noise reduction technology, but also related to the increase of investment in noise reduction facilities in the early stage. Compared with it, the total external cost of high-speed railway noise increases obviously, which is positively related to the rapid development of high-speed railway. With the increase of high-speed railway mileage and passenger turnover, the total noise cost increases significantly. It can be predicted that with the implementation of high-speed railway planning in the future, the negative external cost of noise will continue to increase.
Research on Air Infiltration Characteristics of High-speed Railway Station
Authors: Bin Qian , Liangliang Sun , Tao Yu , Bo Lei , Haiquan Bi
Published: May 2021

High-speed railway station has a large space and a large amount of air infiltration, which has great influences on the thermal load, the thermal environment and the air quality. In this paper, the air infiltration and its distribution characteristics in winter and summer in different climatic zones are determined by CO2 concentration method. The results showed that buoyancy-driven pressure played a dominant role, and the infiltration air volume of 2.8 h-1 in winter is larger than that of 2.0 h-1 in summer. The infiltration air volume in the hot summer and cold winter zone and the hot summer and warm winter zone is larger than that in the cold zone. When the mechanical ventilation system for fresh air is turned off, the indoor CO2 concentration meets the human safety threshold. But it can be found that when the air infiltration volume is small enough to a certain extent, the air infiltration volume has a poor dilutive effect on pollutants in the deeper parts of the station. The tradeoff between the utilization of air infiltration and the elimination of mechanical ventilation needs to be furthered considered.
Adaptive Control of Vehicle Active Suspension Based on Neural Network Optimization
Authors: Qiu Runqi
Published: May 2021

An adaptive proportional–integral–derivative (PID) control method based on radial basis function neural network optimization (RBF-PID) is designed for a four-degree-of-freedom active suspension model of a 1/2 vehicle. By building a simulation model of the suspension in MATLAB/Simulink, a C-level road white noise random excitation signal is used as the road input, and the front and rear body vertical accelerations are simulated as the feedback of the control loop, respectively. The simulation results show that the proposed RBF-PID control strategy can effectively suppress the front and rear body acceleration and effectively reduce the centroid vertical acceleration, and improve the performance by about 10.3% compared with the traditional PID control suspension and about 31.2% compared with the passive suspension, but the control effect improvement for the angular acceleration of body pitch angle is not obvious.
The stability study of goaf based on C-ALS data point cloud and FLAC3DCoupled modeling
Authors: Jia Huihui , Xue Jianzhi
Published: May 2021

Through drilling and three-dimensional scanning by C-ALS laser, the spatial position and size of mined-out area can be obtained. It can provide important technical basis for safety management and evaluation of goaf. This paper takes the stability analysis of Hidden Goaf in the third mining area of Zhoutaizi Iron Mine, Zhangbaiwan town, Luanping County as an example. After the mined-out area was drilled, the data point cloud was obtained by C-als three-dimensional Laser scanning and the three-dimensional visualization model was constructed. Write the conversion program in FISH language and import it into FLAC3D, The distribution characteristics of ground pressure, deformation, failure of surrounding rock and surface subsidence in goaf are analyzed. And it is consistent with the actual situation of the goaf, Thus it shows the feasibility of the coupling modeling technology method of C-ALS data point cloud and FLAC3D in obtaining three-dimensional feature information of goaf and determining the stability of goaf. At the same time it provides technical reference for prospecting and stability analysis of similar goaf.
Research on the Construction of Emergency Logistics Supply Chain System Based on the Outbreak of New Crown Pneumonia
Authors: Wang Landong , Wang Xueqing , Yan Wancheng , Zhang Hanhan , Peng Qihao , Wang Hanjie
Published: May 2021

New Year’s Eve 2020, Wuhan outbreak of new crown pneumonia and spread nationwide. This global epidemic has brought great challenges to the operation of emergency logistics system in China. In the face of this major public health emergency test, we can note that there are still many shortcomings in the current supply chain system of emergency logistics in China. This paper summarizes the experience and lessons accumulated in the anti-epidemic process, aims at all kinds of short boards of the current emergency logistics system and gives the idea of constructing and perfecting it.
Relationship between microbial community structures and degradation efficiencies in biological contact process on domestic sewage
Authors: Sulemana Husseini , Nkudede Emmanuel , Zhang Bo , Kosiba Anthony Adebayiga , Mochiwa Zaina Omary
Published: May 2021

In order to ascertain the characteristics of two different biofilm reactors and its efficiency, the influence of pH, DO and HRT in the clean-up of COD, NH3-N and TP as well as determining the relationship between microbial community structures and its performance of the two biofilm reactors. This study made use of a biological contact oxidation process system in a small-scale experiment to treat domestic sewage. This contemporary study examined the performance of two different fillers thus, BCF and MBBF in removal of organic pollutants from domestic wastewater as a novel technique of BCOP for sewage treatment. Two self-made biological contact biofilm reactors were used for the experiment: BCR (mounted with BCF) and MBBR (mounted with MBBF). After the biological treatment, the COD concentration of effluent could stay below 350 mg/L. The study analyzed the effects of hydraulic residence time (HRT) on COD, ammonia nitrogen (NH3-N), and total phosphorus (TP) as well as the characteristics of each biofilm filler. The optimal HRT was 12 h; at that time, the experimental results indicated that BCF had higher removal efficiency of chemical oxygen demand, ammonia-nitrogen and total phosphorus at 50%, 96%, and 86%, respectively. Great contribution was made by the process by means of improving the biodegradability of domestic sewage and reducing sludge emergence via fermentation in the biological reactor.
The role of plant-associated bacteria in the phytoremediation of heavy metal contaminated soils
Authors: Han Mengxuan , Yang Huan , Ding Na , You Shaohong , Yu Guo
Published: May 2021

Soil heavy metal pollution is an important environmental problem threatening people’s health and sustainable economic development. Phytoremediation has become an important technology for the treatment of heavy metal contaminated soil with the characteristics of economy and environmental protection. This paper mainly analyzed the role of microbial community in heavy metal contaminated soil remediation process. Bacterias mainly strengthen the remediation effect of plants on heavy metal contaminated soil in two ways: first, bacterias have adsorption effect on heavy metals and reduce the toxicity of heavy metals to plants in soil; Two is to secrete organic acids and nutrients needed for plant growth to promote the absorption of heavy metals by hyperaccumulators.
Using electric flocculation to treat domestic laundry wastewater with different types of detergents
Authors: Hu Shan , Zhang Bo , Xu Yi
Published: May 2021

Laundry wastewater contains a large number of surfactants, suspended solids and other pollutants, and the COD value is high. If the wastewater is discharged into the water without harmless treatment, it will cause serious environmental pollution. The electrocoagulation process was selected as a promising environmentally friendly technology for treating domestic laundry wastewater. In this paper, the contribution of the liquid and powder detergents to the composition of domestic laundry wastewater was investigated. Combination of stainless steel and aluminum anode electrodes were compared. The effect of electrolysis time and current density on the removal of COD, LAS and turbidity of liquid detergent and powder detergent laundry wastewater were evaluated. The experimental results showed the electrocoagulation process has significant removal. It was found that the electrolysis time in 25 minute, current density in 5 mA/cm2 had optimum efficiency when considering efficient removal and economic energy consumption. For Liquid detergent laundry wastewater, COD, LAS and turbidity removal rates were 84%, 93% and 96%. For powder detergent laundry wastewater, COD, LAS and turbidity removal efficiency were 80%, 83% and 91%, respectively. Energy consumption in the optimum conditions for liquid detergent and powder detergent laundry wastewater by electrocoagulation were 7.324KWh/m3, 3.642KWh/m3, respectively, while using combination of stainless steel and aluminum anode electrodes equals 1 to 1.
Research on urban and rural high-quality development based on ecological restoration of coal mining subsidence area
Authors: Yang Long , Wang Xiangchun , Chu Yangyang , Qin Fei , Wang Siyu
Published: May 2021

Ecological restoration of coal mining subsidence area is of great significance to improve the ecological and living environment, enrich the supply of ecological products, promote the green transformation of resource-based cities and the high-quality development of urban and rural areas. This paper combs the significance of ecological restoration in coal mining subsidence area to promote the high-quality development of urban and rural areas, systematically expounds the realization path of ecological restoration to promote urban-rural spatial integration, cultural integration, economic integration and social integration development by taking Pan’an Lake coal mining subsidence area as a case. Finally, the high-quality development evaluation index system of coal mining subsidence area based on ecological restoration is put forward, and the prospect of ecological restoration and high-quality development in coal mining subsidence area are discussed.
Characteristics of heavy metal accumulation in five wild plants in Huize Lead-Zinc mining area
Authors: Mou Fengli , Yang Jingmin , Li Biwen , Chen Jianjun , Wang Jixiu
Published: May 2021

In order to screen out the plants used to repair heavy metal pollution in the soil, five plants and surface soil were collected in the Huize lead-zinc mine area, centered on the hyperaccumulator plant Arabis alpina L. var. parviflora Franch, measured the heavy metal content of in shoot and root of plant and surface soil, and analyzed the characteristics of heavy metal accumulation in plants. The results showed that the soil Cd pollution in the Huize lead-zinc mining area was the most serious; among the five plants, the Cd bioconcentration factor(BCF) and translocation factor(TF) of A. alpina were more than 1, and the TF of Pb was more than 1; the TF of Anaphalis margaritacea, Cyananthus inflatus and Arenaria orbiculata to Cu and Zn were more than 1, the TF of Juncus effusus to Cd and Zn were more than 1. These five plants had good tolerance to heavy metals and were of great significance to the remediation and restoration of heavy metal contaminated soil in lead-zinc mining areas.
Research on Evaluation Method of Ecological Environment Quality Based on the Improvement of Human Settlement Environment
Authors: Chen Xi , Gao Xia , Li Xianyue
Published: May 2021

Against the background that ecological environment quality has become a hot research topic in recent years, ecological environment quality assessment has emerged as an emerging discipline. By adopting scientific methods, it objectively and quantitatively reveals the real situation of ecological environment quality, and is committed to providing support basis for environmental protection and comprehensive prevention and control. Therefore, how to develop a reasonable eco-environmental quality assessment system has become the focus of attention. Based on this, this paper summarizes the research results in this field at home and abroad, and discusses and illustrates the main existing evaluation methods and evaluation models through horizontal and vertical analysis. The development status of ecological environment quality evaluation research field and the application characteristics of different evaluation methods are analyzed, some problems in theoretical innovation, model construction and application of conclusions are discussed, and the development trend of ecological environment quality evaluation research is proposed based on this.
Application of aquatic plants in urban ecological construction of Kunming
Authors: Cao Yongqiong , She Lina , Wv Yumei , Zhao Feng
Published: May 2021

Aquatic plants play an important role in urban construction. According to the application status of aquatic plants in urban construction of Kunming, It is suggested that aquatic herbs should be used as the main plant to optimize the allocation; Reasonable harvest management should be carried out; Effective control of aquatic plant biomass and other measures. To construct a biodiversity aquatic plant community. Accelerate the pace of urban ecological construction.
Comparative analysis of low-energy buildings to help achieve carbon neutrality technology
Authors: Zhang Zhizheng , Hou Qingying , Tao Jin , Zhang Hao , Chou Xuesong , Jiang Xiangting
Published: May 2021

The development of low-energy buildings is an important initiative to achieve carbon peaking by 2030 and carbon neutrality by 2060. According to the data of the relevant papers, if all the northern urban and rural buildings in China adopt passive ultra low energy building technology, it can save about 350 million tons of coal for heating and reduce about 900 million tons of carbon dioxide emissions each year. It’s of great significance to achieve the goals of “peak carbon dioxide emissions” and “carbon neutrality”. Starting from four key technologies for low-energy buildings, explanation and analysis the energy-saving methods for low-energy buildings, It also presents the challenges and suggestions for the development of low-energy buildings in China.
Sensitivity analysis, identification and validation of the dislocation density-based model for metallic materials
Authors: Szeliga Danuta , Czyżewska Natalia , Klimczak Konrad , Kusiak Jan , Morkisz Paweł , Oprocha Piotr , Pietrzyk Maciej , Przybyłowicz Paweł
Published: May 2021

Microstructure evolution model based on the differential equation describing evolution of dislocations was proposed. Sensitivity analysis was performed and parameters with the strongest influence on the output of the model were revealed. Identification of the model coefficients was performed for various metallic materials using inverse analysis for experimental data. The model was implemented in the finite element code and simulations of various hot forming processes were performed.
Skillstraining bei Patienten im ambulanten Setting
Authors: Nüsse Katrin
Published: May 2021

Seit rund drei Jahren wird auch in der ambulanten fachpsychiatrischen Pflege das Skillstraining bei Patienten mit Posttraumatischer Belastungsstörung eingesetzt. Da das Training zu Hause bei den Patienten stattfindet, sind Pflegende mit sehr unterschiedlichen Gegebenheiten konfrontiert. Angepasst an die Bedürfnisse der Patienten müssen individuelle Skills ausgewählt und trainiert werden.
Recent Antiviral Treatment and Vaccination Strategies Against SARS-CoV-2
Authors: Bormann Maren , van de Sand Lukas , Witzke Oliver , Krawczyk Adalbert
Published: May 2021

Since the end of 2019, the novel severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) has been spreading worldwide and has caused severe health and economic issues on a global scale. By the end of February 2021, more than 100 million SARS-CoV-2 cases had been reported worldwide. SARS-CoV-2 causes the coronavirus disease 2019 (COVID-19) that can be divided into three phases: An early phase with fever and cough (phase I), a pulmonary vascular disease (phase II) and a hyperinflammatory syndrome (phase III). Since viral replication plays a particularly important role in the early stage of the disease and the patientʼs immune system in the later course of infection, different therapeutic options arise depending on the stage of the disease. The antiviral nucleoside analogue remdesivir is the only antiviral compound with conditional approval in the European Union. Treatment with remdesivir should be initiated early (within the first seven days of symptom onset) in
patients receiving supplemental oxygen without invasive ventilation. In turn, the anti-inflammatory corticosteroid dexamethasone should be administered later in the course of disease in patients receiving oxygen therapy. Since autopsies indicate an increased frequency of thromboembolic events due to COVID-19, additional treatment with anticoagulants is recommended. Since the development of novel antivirals may take years, the application of convalescent plasma from patients who recovered from a SARS-CoV-2 infection for the treatment of COVID-19 is reasonable. However, large-scale studies indicated low efficacy of convalescent plasma. Furthermore, vaccination of the population is essential to control the pandemic. Currently, the mRNA vaccine Tozinameran from BioNTech and Pfizer, the mRNA-1273 vaccine from Moderna as well as the vector vaccine AZD1222 from AstraZeneca are licensed in the European Union. All three vaccines have demonstrated high efficacy in large clinical
trials. In addition to these licensed vaccines, many others are being tested in clinical trials. In the present article, an overview of therapeutic options for COVID-19 as well as vaccines for protection against SARS-CoV-2 is provided.
Der Zusammenhang zwischen COVID-19 und Schlaganfall: Pathophysiologie und klinische Bedeutung
Authors: Siepmann Timo , Barlinn Kristian
Published: May 2021

Dass COVID-19 mit einem erhöhten Risiko für das Auftreten ischämischer Schlaganfälle einhergeht, wurde bereits in den ersten Monaten nach dem weltweiten Bekanntwerden des Ausbruchs der Pandemie im Ground Zero Wuhan deutlich. Spätere Kohortenanalysen, Fallserien und Meta-Analysen bestätigten diesen Zusammenhang. Eine nicht unerhebliche geographische Variabilität der Prävalenz COVID-19-bezogener Schlaganfälle verdeutlicht allerdings den fortbestehenden Bedarf an umfassenden epidemiologischen Analysen. Im Übrigen fanden sich zunehmend Hinweise dafür, dass dem mit COVID-19 assoziierten Schlaganfall ein multifaktorieller pathophysiologischer Mechanismus zugrundeliegenden könnte. Neben einer durch die SARS-CoV-2-Infektion verursachten Hyperkoagubilität, die sowohl im mikrovaskulären System als auch in Großgefäßen thrombogen wirkt, scheinen vaskulitische arterielle Veränderungen und kardiogene Embolien infolge virusassoziierter myokardialer Schädigung bei der Ätiologie des COVID-19-assoziierten Schlaganfalls eine Rolle zu spielen. Die Versorgung von Schlaganfallpatienten/innen in Zeiten der Pandemie durch multidisziplinäre Teams scheint in insgesamt kompensierten Kliniken im Wesentlichen nicht kompromittiert zu sein. Hinweise, dass Patienten/innen mit COVID-19-assoziiertem Schlaganfall von einem intensivierten Monitoring und einer aggressiveren Sekundärprävention profitieren, bedarf klinischer Prüfung.
Versorgungsnahe Daten zur Evaluation von Interventionseffekten: Teil
2 des Manuals
Authors: Hoffmann Falk , Kaiser Thomas , Apfelbacher Christian , Benz Stefan , Bierbaum Thomas , Dreinhöfer Karsten , Hauptmann Michael , Heidecke Claus-Dieter , Koller Michael , Kostuj Tanja , Ortmann Olaf , Schmitt Jochen , Schünemann Holger , Veit Christof , Hoffmann Wolfgang , Klinkhammer-Schalke Monika
Published: May 2021

Die Evaluation von Interventionseffekten ist eine wichtige Domäne der
Versorgungsforschung. Die vom Deutschen Netzwerk Versorgungsforschung (DNVF) ins
Leben gerufene Ad hoc Kommission zur Nutzung versorgungsnaher Daten
beschäftigt sich in diesem zweiten Teil des Manuals deshalb mit der
Nutzung dieser Daten zur Evaluation von Interventionseffekten. Zunächst
erfolgt dabei eine Aufarbeitung der Begriffsbestimmung und Diskussion zur
Bedeutung von Kontextfaktoren. Anschließend werden sowohl allgemeine
Anforderungen an Planung, Datenerhebung und Auswertung sowie konkrete Beispiele
zur Evaluation von Interventionseffekten für die 3 Anwendungsfelder
Arzneimitteltherapie, nicht-medikamentöse Maßnahmen sowie
komplexe Interventionen herausgearbeitet. Dabei werden sowohl Szenarien
betrachtet, bei denen bisher keine Informationen aus direkt vergleichenden
randomisierten kontrollierten Studien (RCTs) vorliegen bzw. bereits RCTs
vorhanden sind, jedoch eine Erweiterung der Fragestellung erforderlich ist. Im
Zentrum steht bei allen Beispielen an erster Stelle immer die Frage, ob die
Datenquelle für die entsprechende Forschungsfrage geeignet ist und zwar
unabhängig davon, ob eine Studie mit oder ohne Randomisierung
durchgeführt wird. Die gewählten Beispiele stammen
größtenteils aus der Onkologie, weil die hierfür
notwendigen Daten zumindest in Ansätzen bereits für Deutschland
vorliegen. Abschließend diskutiert das Manual mögliche
Herausforderungen für eine zukünftige Nutzung dieser Daten.
Diagnostik der weiblichen Harninkontinenz: Dos and Dontʼs
Authors: Jaekel Anke K. , Kirschner-Hermanns Ruth , Knüpfer Stephanie C.
Published: May 2021

Die Harninkontinenz schränkt die physische und psychische Gesundheit sowie die Lebensqualität der Betroffenen stark ein. Sie stellt eine weitverbreitete chronische Erkrankung dar, aktuell sind über 200 Mio. Menschen weltweit betroffen. Frauen sind deutlich häufiger harninkontinent als Männer. Es existieren derzeit eine Vielzahl an konservativen und operativen Therapiemaßnahmen zur Behandlung der weiblichen Harninkontinenz. Zum effektiven und erfolgreichen Einsatz dieser Maßnahmen ist die umfassende Diagnostik der zugrundeliegenden anatomischen und funktionellen Veränderungen unerlässlich. Die vorliegende Arbeit stellt die diagnostischen Möglichkeiten der weiblichen Harninkontinenz von der nicht-invasiven bis hin zur invasiven Untersuchung vor. Es werden mögliche Fallstricke und Verbesserungsmöglichkeiten der einzelnen Verfahren beschrieben.
History Page: Leaders in MSK Radiology Karl Dussik, 1908–1968: Pioneer of MSK Ultrasonography
Authors: Sudoł-Szopińska Iwona , Martinoli Carlo , Panas-Goworska Marta
Published: May 2021

This history page in the series “Leaders in MSK Radiology” is dedicated to the memory and achievements of Karl Theodore Dussik, the Austrian neurologist and psychiatrist from the University of Vienna who is recognized as the pioneer of ultrasonography.
Imaging of Pediatric Soft Tissue Tumors and Tumor-like Conditions
Authors: Al-Qassab Sinan , Lalam Radhesh , Botchu Rajesh , Bazzocchi Alberto
Published: May 2021

Lumps and bumps are frequently seen in children, and the vast majority are a result of trauma, infection, or inflammation. True soft tissue neoplastic lesions are rare; however, their wide and complex classifications make these lesions challenging to manage. Imaging features are usually nonspecific, and a reasonable list of differential diagnoses can be generated following consideration of the clinical presentation, age, and anatomical location of the lesion. In this article, we offer a practical approach to diagnosing such lesions by discussing the most common three benign and malignant lesions in different anatomical regions stratified by age with emphasis on certain features that might aid in the diagnosis such as depth, multiplicity, calcification, or other specific imaging feature.
Conventional Radiography and Ultrasound Imaging of Rheumatic Diseases Affecting the Pediatric Population
Authors: Pracoń Grzegorz , Aparisi Gómez Maria Pilar , Simoni Paolo , Gietka Piotr , Sudoł-Szopińska Iwona
Published: May 2021

Juvenile idiopathic arthritis is the most frequent rheumatic disease in the pediatric population, followed by systemic lupus erythematosus, juvenile scleroderma syndromes, juvenile dermatomyositis, chronic recurrent multifocal osteomyelitis, and juvenile vasculopathies. The imaging approach to inflammatory connective tissue diseases in childhood has not changed dramatically over the last decade, with radiographs still the leading method for bony pathology assessment, disease monitoring, and evaluation of growth disturbances. Ultrasonography is commonly used for early detection of alterations within the intra- and periarticular soft tissues, assessing their advancement and also disease monitoring. It offers several advantages in young patients including nonionizing radiation exposure, short examination time, and high resolution, allowing a detailed evaluation of the musculoskeletal system for the features of arthritis, tenosynovitis, enthesitis, bursitis, myositis, as well as pathologies of the skin, subdermis, vessels, and fasciae. In this pictorial essay we discuss radiographic and ultrasound inflammatory features of autoimmune pediatric inflammatory arthropathies: juvenile idiopathic arthritis, lupus erythematosus, juvenile scleroderma, juvenile dermatomyositis and polymyositis.
MR Imaging of Rheumatic Diseases Affecting the Pediatric Population
Authors: Schiettecatte Eva , Jans Lennart , Jaremko Jacob Lester , Chen Min , Vande Walle Caroline , Herregods Nele
Published: May 2021

This article reviews the application of magnetic resonance imaging (MRI) to pediatric rheumatic diseases. MRI can detect early manifestations of arthritis, evaluate the extent of disease, and monitor disease activity and response to treatment.

Juvenile idiopathic arthritis (JIA) is the most common pediatric rheumatic disorder, representing a diverse group of related diseases that share a definition of joint inflammation of unknown origin with onset before 16 years of age and lasting > 6 weeks. JIA may lead to significant functional impairment and is increasingly imaged with MRI to assess for active inflammation as a target for therapy. This is particularly true for juvenile spondyloarthritis that includes multiple subgroups of JIA and primarily involves the spine and sacroiliac joints.

Other less common pediatric rheumatic diseases considered here are chronic recurrent multifocal osteomyelitis and collagen vascular diseases including polymyositis, dermatomyositis, scleroderma, and juvenile systemic lupus erythematosus.
ALDH7A1 Gene and Its Related Pyridoxine-Dependent Epilepsy
Authors: La Mendola Flavia Maria Consuelo , Timpanaro Tiziana , Caruso Daniela , Garozzo Maria Teresa , Presti Santiago , Romano Catia , Praticò Elena R. , Lombardo Giulia , Zanghì Antonio , Falsaperla Raffaele
Published: May 2021

Despite being classically reported as caused by mutations in solute carriers genes (SLC2A1), it has been recently shown that also mutations in ALDH7A1 can cause pyridoxine-dependent epilepsy (PDE). ALDH7A1 is a gene encoding for the antiquitin, an enzyme that catalyzes the nicotinamide adenine dinucleotide-dependent dehydrogenation of L-α-aminoadipic semialdehyde/L-Δ1-piperideine 6-carboxylate. It is a highly treatable disorder, but nevertheless it is still not certain when to consider this diagnosis and how to test for it. It is possible to identify a classical form and an atypical one of PDE associated with more than 70 mutations of ALDH7A1 gene. The typical form is characterized by the onset of seizures within the first month of life and can be treated with pyridoxine in monotherapy, as they are not responsive to traditional anticonvulsant therapy. The atypical forms are equally pyridoxine-dependent, but are characterized by a later onset of seizures, sometimes up to the age of 3 years. Several brain abnormalities have been associated with ALDH7A1 mutations. Seizure control is achieved by the administration of high-dose pyridoxine, which must be started in the patient as soon as possible. However, it has been observed that pyridoxine therapy does not prevent developmental delay in most cases; in these cases, it can be recommended and useful to supplement arginine with pyridoxine therapy associated with a dietary restriction of lysine.
Musculoskeletal Interventional Radiology in the Pediatric Population: State of the Art
Authors: Arrigoni Francesco , Izzo Antonio , Bruno Federico , Palumbo Pierpaolo , De Filippo Massimo , Zugaro Luigi , Masciocchi Carlo , Barile Antonio
Published: May 2021

Interventional radiology procedures have been proven to be as effective as traditional surgery but usually are characterized by lower morbidity rates. In this article, the most diffuse IR treatments for pediatric lesions are reviewed with the aim of describing main advantages and drawbacks. Ablation procedures (in particular RFA and MRgFUS) are widely used for the management of osteoid osteoma and osteoblastoma whereas intracystic injection of methylprednisolone acetate is performed for simple bone cysts. Sclerosing agents and where possible, selective arterial embolization are used for treatment of aneurysmal bone cysts and other vascular malformations. In the management of malignant muscoloskeletal tumors, the role interventional radiology is mainly represented by percutaneous biopsies, and by adiuvant selective embolizations in presence of hypervascular lesions to be submitted to surgery.
On their own turf? The level-specificity of political trust in multilevel political systems
Authors: Proszowska Dominika , Jansen Giedo , Denters Bas
Published: May 2021

Although the debate on roots of political trust is ongoing, many scholars agree on the relevance of such political factors as political/ideological distance between citizens and incumbents, political responsiveness and perceptions of performance. Less clear is to what extent such trust evaluations are generalized or specific for the three main political arenas in the European multilevel governance system (EU, national, local). With new data from the Netherlands, we demonstrate that trust in local, national and EU governments (1) is largely level-specific (i.e. is based on citizens’ perceptions of incumbents at a particular governance level) (2) and—at all three levels—is explained by level-specific political factors. This shows that political trust is a subjectively rational evaluation and that citizens develop meaningful political orientations vis-à-vis governments at different levels. Therefore, trust spillovers may be less relevant for explaining political trust in multilevel governance than assumed in previous research as executive governments at local, national and EU levels are judged “on their own turf”.
Hidden duality and accidental degeneracy in cycloacene and Möbius cycloacene
Authors: Sadurní Emerson , Leyvraz Francois , Stegmann Thomas , Seligman Thomas H. , Klein Douglas J.
Published: May 2021

The accidental degeneracy appearing in cycloacenes as triplets and quadruplets is explained with the concept of segmentation, introduced here with the aim of describing the effective disconnection of π orbitals on these organic compounds. For periodic systems with time reversal symmetry, the emergent nodal domains are shown to divide the atomic chains into simpler carbon structures analog to benzene rings, diallyl chains, anthracene (triacene) chains, and tetramethyl-naphthalene skeletal forms. The common electronic levels of these segments are identified as members of degenerate multiplets of the global system. The peculiar degeneracy of Möbius cycloacene is also explained by segmentation. In the last part, it is shown that the multiplicity of energies for cycloacene can be foreseen by studying the continuous limit of the tight-binding model; the degeneracy conditions are put in terms of Chebyshev polynomials. The results obtained in this work have important consequences on the physics of electronic transport in organic wires, together with their artificial realizations.
Development of a Langmuir probe array for radial potential profile measurement in the collisional merging formation FRC
Authors: Akashi K. , Iijima Y. , Kobayashi D. , Asai T. , Roche T. , Morelli J.
Published: May 2021

The radial electric field in a field-reversed configuration (FRC) plasma plays an important role in the global stability and confinement properties. Herein, we developed a new Langmuir probe array named “Skewered probe” employed in measuring the radial potential profile in the collisional merging formation of an FRC in the FAT-CM (FRC Amplification via Translation - Collisional Merging) device. Because an FRC has a strong toroidal flow, the skewered probe consists of alternately skewered ring electrodes and ceramic beads on a thin stainless-steel tube to neutralize the effect of plasma flow. The developed array has nine electrodes, one every 2 cm from r = 9–25 cm, and it measures the FRC boundary in the case when the radius of the excluded flux ranges from 10 to 20 cm. The skewered probe also has one additional electrode that measures the potential near the chamber wall as a reference for the other electrodes. The radial potential profile of the FRC formed by the collisional merging method in the FAT-CM device was measured using the probe, and the results showed that the region of negative potential gradually changed to a positive potential after merging the FRCs. It was also shown that a strong outward electric field is formed near the separatrix at n = 2 rotational instability.
Multi-point density measurement of a collisional merging formation process of FRCs
Authors: Tatsumi A. , Asai T. , Takahashi Ts. , Kobayashi D. , Someya H.
Published: May 2021

Collisional merging formation of field-reversed configuration (FRC) plasmas at supersonic velocities was performed using the FRC amplification via translation-collisional merging device. Supersonic collisional merging formation is a novel technique to form an FRC that is long-lived compared to a conventional initial formation FRC; however, this technique requires measuring the plasma parameters at multiple points simultaneously because of the dynamic translation/merging process. Herein, we have developed a new interferometer and have observed the dynamic behavior of FRCs in the formation, translation, and merging processes simultaneously. In this study, as one of the performance evaluations of the developed simultaneous density measurement, collision/merging of FRCs have been conducted in the confinement section with and without background neutral gas. Comparing translation into deuterium gas vs translation into a vacuum environment prior to the collisional merging, we found that the background neutral particles were trapped in the merged FRC; moreover, a difference in the decay rate of the stored internal energy was observed.
Anisotropy and domain formation in a dipolar magnetic metamaterial
Authors: Digernes Einar , Strømberg Anders , Vaz Carlos A. F. , Kleibert Armin , Grepstad Jostein K. , Folven Erik
Published: May 2021

Long-range magnetic ordering can be stabilized in arrays of single-domain nanomagnets through dipolar interactions. In these metamaterials, the magnetic properties are determined by geometric parameters such as the nanomagnet shape and lattice symmetry. Here, we demonstrate engineering of the anisotropy in a dipolar magnetic metamaterial by tuning of the lattice parameters. Furthermore, we show how a modified Kittel's law explains the resulting domain configurations of the dipolar ferromagnetic arrays.
Reactive species driven oxidative modifications of peptides—Tracing physical plasma liquid chemistry
Authors: Wenske Sebastian , Lackmann Jan-Wilm , Busch Larissa Milena , Bekeschus Sander , von Woedtke Thomas , Wende Kristian
Published: May 2021

The effluence of physical plasma consists of a significant share of reactive species, which may interact with biomolecules and yield chemical modifications comparable to those of physiological processes, e.g., post-translational protein modifications (oxPTMs). Consequentially, the aim of this work is to understand the role of physical plasma-derived reactive species in the introduction of oxPTM-like modifications in proteins. An artificial peptide library consisting of ten peptides was screened against the impact of two plasma sources, the argon-driven MHz-jet kINPen and the helium-driven RF-jet COST-Jet. Changes in the peptide molecular structure were analyzed by liquid chromatography–mass spectrometry. The amino acids cysteine, methionine, tyrosine, and tryptophan were identified as major targets. The introduction of one, two, or three oxygen atoms was the most common modification observed. Distinct modification patterns were observed for nitration (+N + 2O–H), which occurred in kINPen only (peroxynitrite), and chlorination (+Cl–H) that was exclusive for the COST-Jet in the presence of chloride ions (atomic oxygen/hypochlorite). Predominantly for the kINPen, singlet oxygen-related modifications, e.g., cleavage of tryptophan, were observed. Oxidation, carbonylation, and double oxidations were attributed to the impact of hydroxyl radicals and atomic oxygen. Leading to a significant change in the peptide side chain, most of these oxPTM-like modifications affect the secondary structure of amino acid chains, and amino acid polarity/functionality, ultimately modifying the performance and stability of cellular proteins.
Impact of formation process on the radiation properties of single-photon sources generated on SiC crystal surfaces
Authors: Hijikata Yasuto , Komori Shota , Otojima Shunsuke , Matsushita Yu-Ichiro , Ohshima Takeshi
Published: May 2021

Radiation centers that are generated on the surface of SiC crystals [surface single-photon sources (SPSs)] have received much attention because they behave as high-brightness SPSs at room temperature. However, little is known about surface SPSs, such as their defect structure and radiation properties. To achieve a better understanding of surface SPSs, we investigated the impact of the formation processes of SPSs on the radiation properties. Low temperature photoluminescence (PL) measurements indicated that the photon energies of the zero-phonon line (ZPL) were dispersed in the range of 0.33 eV. In comparison between the (0001) Si-face and (11–20) a-face, the energy dispersion for the a-face was smaller, which suggests that the energy dispersion was attributed to stacking faults at the oxide–SiC interface. The differences in the radiation properties of the surface SPSs were clarified according to the formation process in terms of the oxide thickness and post-oxidation Ar annealing. The results showed that the wavelength dispersion was increased with the oxide thickness, and Ar annealing caused various changes in the radiation properties, such as a reduction in the density of SPSs, and the radiation intensity of the ZPL as well as a shift in the ZPL wavelength. Notably, most of the changes in the defect structure occurred at the Ar anneal temperature of 600 °C, and we discuss some of the types of defects that change at this temperature.
Linear instability of an annular liquid jet with gas velocity oscillations
Authors: Guan Xin-yan , Jia Bo-qi , Yang Li-jun , Fu Qing-fei
Published: May 2021

Pressure fluctuation produced in liquid rocket engines affects atomization of the annular liquid jet in the combustion chamber. A linear stability analysis of an annular liquid jet under acoustic oscillations was conducted in this work. Parametric instability was applied to study the problem, and the oscillations of the gas velocity were considered. The Floquet theory was used to solve the disturbance, from which the dispersion equation containing the coefficients of the infinite order matrix was derived; the order of the coefficient matrix affected the accuracy of the results. There were several unstable regions in the wavenumber range, obtained by solving the dispersion matrix. When the gas velocity oscillated, the amplitude of the surface wave displacement also oscillated. In various unstable regions, the growth of the surface wave of the annular liquid sheet was also different, but the crest never passed through the equilibrium position, which was more complicated than in the planar liquid sheet. Increasing oscillation frequency contributed to an increase in the wavenumber corresponding to the unstable area. Increasing the oscillation amplitude increased the maximum growth rate. The effect of physical parameters on the instability of the annular liquid jet was also discussed.
Simultaneous thickness and thermal conductivity measurements of thinned silicon from 100 nm to 17 μm
Authors: Scott Ethan A. , Perez Christopher , Saltonstall Christopher , Adams David P. , Carter Hodges V. , Asheghi Mehdi , Goodson Kenneth E. , Hopkins Patrick E. , Leonhardt Darin , Ziade Elbara
Published: May 2021

Studies of size effects on thermal conductivity typically necessitate the fabrication of a comprehensive film thickness series. In this Letter, we demonstrate how material fabricated in a wedged geometry can enable similar, yet higher-throughput measurements to accelerate experimental analysis. Frequency domain thermoreflectance (FDTR) is used to simultaneously determine the thermal conductivity and thickness of a wedged silicon film for thicknesses between 100 nm and 17 μm by considering these features as fitting parameters in a thermal model. FDTR-deduced thicknesses are compared to values obtained from cross-sectional scanning electron microscopy, and corresponding thermal conductivity measurements are compared against several thickness-dependent analytical models based upon solutions to the Boltzmann transport equation. Our results demonstrate how the insight gained from a series of thin films can be obtained via fabrication of a single sample.
Manipulating Light: Lenses and Prisms
Authors: Elliott Barry
Published: May 2021

We need to be able to manipulate and control light and the classical method employed is to use mirrors, lenses and prisms. In this chapter we look at the basics of lenses, prisms and couplers. Lenses are used primarily to focus light to a point to form a sharp image but lenses can also diverge light and collimate light. Collimation is a useful property in optical communications whereby a divergent set of beams from a quasi-point source can be passed through a lens to bring the light into parallel rays. A lens is made of a transparent material and the passage of the light through it is controlled by the refractive index of the material and the optical geometry of the device. In this section we look at the basic types of lenses and the various problems of aberration they suffer from. Perfect imaging is not always the main aim of optical communications and collecting photons and focussing them onto a detector is generally more important. This takes us into a discussion of the theory and application of prisms and Fresnel lenses and how these lower cost optical devices meet the requirements of optical communications engineering.
The creation and detection of light
Authors: Elliott Barry
Published: May 2021

Unless we are using a heliograph or smoke signals then we need to produce light for our optical communication system. By using electronic methods this means spontaneous or stimulated emission of a photon when an electron drops to a lower energy orbit. In this chapter we look at the basics of semiconductor p-n junctions and their use in Light Emitting Diodes, LEDs, and lasers. In the section on LEDs we move from simple planar constructions, which demonstrate the concept, to the more practical edge emitting devices. We build on this to discuss how lasers work and concentrate on the two types most used in communications systems which are the Distributed Feed Back, or DFB laser, and the vertical cavity surface emitting laser or VCSEL and its use of the Distributed Bragg Reflector mechanism. We conclude the chapter by considering the reception and detection of light, again using LEDs, and we consider the PIN photodiode and the APD, or avalanche photodiode, where higher sensitivity is required. In every case we will consider the essential parameters and requirements of optical systems such as wavelengths of use and matching bandwidth and rise/fall times between transmitter, optical channel and receiving device.
Guiding Light: Optical Fiber
Authors: Elliott Barry
Published: May 2021

Optical communications can be divided into Line of Sight, LOS, systems, and guided light methods. In this chapter we shall consider guiding light through silica-based optical fibres which represents by far the majority of optical communications systems. This chapter defines single and multimode fibre construction and operation and the attempts to minimize dispersion which is the limiting factor for information carrying capacity for all optical fibres. Dispersion limits the bandwidth by smearing out the digital optical pulses in time so that the sharp edges are lost as different components of the signal arrive at different times and so eventually the pulses merge into each other. Chromatic and modal dispersion are the two main culprits although there are subdivisions to these two headings which need to be defined. Singlemode fibre effectively removes modal dispersion but all fibres suffer from chromatic dispersion though we will see that for modern wavelength division multiplexing systems some level of chromatic dispersion is actually built in. Chromatic dispersion primarily comes from material and waveguide dispersion and it is these which can be ‘tuned’ to provide a range of ITU-defined fibres to cover a range of telecommunications applications.
Testing Optical Systems
Authors: Elliott Barry
Published: May 2021

In testing optical systems there are generally four parameters of interest: attenuation of the link, its return loss, the continuity and polarity of the optical links and the length of the link. Other parameters of interest, such as bandwidth, cannot easily be tested outside of a laboratory and system bandwidth is normally inferred from the optical fibre specification e.g. for a multimode fibre two kilometres of 2000 MHz.km fibre should yield a system bandwidth of 1000 MHz. As discussed in Chapter 8, bandwidth of singlemode fibre systems is not often discussed and the principal limiting factor of dispersion is the metric of choice. It should be noted that testing of optical fibre installations would also include a visual inspection of fibre connector end-faces to ensure cleanliness and absence of fractures and chips across the core of the fibre. Attenuation of the link, at all the wavelengths of interest, is a key factor in determining if an optical link will actually work. Enough light must reach the receiver for the signal to be distinguishable from the background noise. In this chapter we will focus on the techniques of light source/power meter measurements and Optical Time Domain Reflectometry, OTDR.