bluuebunny/crossref_metadata_2025 huggingface dataset:
Selenium-containing two-dimensional conjugated fused-ring electron acceptors for enhanced crystal packing, charge transport, and photovoltaic performance
Authors: Wan Shi-Sheng , Zhao Qiaoqiao , Jiang Zhao , Yuan Gui-Zhou , Yan Lu , Ryu Hwa Sook , Mahmood Asif , Liu Yan-Qiang , Li Heng , Woo Han Young , He Feng , Wang Jin-Liang
Published: June 2021

The selenium-containingC8T-BDSe4Cl-based PSCs exhibit higher PCE (13.5%) with largerJscrelative to those of the corresponding sulfur-containing analogue, which ascribes the narrower optical bandgap and enhanced molecular packing.
Coupling of EDLC and the reversible redox reaction: oxygen functionalized porous carbon nanosheets for zinc-ion hybrid supercapacitors
Authors: Wang Li , Huang Mingtao , Huang Jun , Tang Xiannong , Li Longbin , Peng Mengke , Zhang Kaiyang , Hu Ting , Yuan Kai , Chen Yiwang
Published: June 2021

Oxygen functionalized carbon nanosheets are constructed for use as cathode for boosting the performance of zinc-ion hybrid supercapacitors via the synergistic effect of EDLC and pseudocapacitance from the reversible transformation of oxygen functional groups.
Steganography based on quotient value differencing and pixel value correlation
Authors: Sonar Reshma , Swain Gandharba
Published: June 2021

Pixel value differencing (PVD) steganography techniques produce imperceptible stego‐images. Most PVD‐based techniques have a fall‐off boundary problem (FOBP). To avoid FOBP, a steganographic scheme is presented that combines the quotient value difference (QVD) with pixel value correlation (PVC). It performs data embedding in two stages on 3 × 3 size pixel blocks. The first stage of the embedding procedure performs QVD and remainder substitution on five pixels. These five pixels are central pixel and it's neighbours on the left, right, upper, and lower sides. Based on the new values of these five pixels, the PVC embedding procedure is applied on the remaining four corner pixels of the block. The experimental results are found to be improved. The hiding capacity is high that is 3.92 bits per byte with an acceptable peak signal‐to‐noise ratio value. A security check was performed using two tests: (i) a regular‐singular (RS) test, (ii) a pixel difference histogram (PDH) test. The experimental outcomes demonstrate that PDH curves of the stego‐images do not have a zigzag shape, that means the PDH test could not detect this steganography technique. Furthermore, the RS curves show that the RS test could not detect this steganography technique.
Analysis of water saving in the construction process based on green building
Authors: Wu Shiyao , Zou Zuxu , Fan Shuyi
Published: June 2021

Under the premise of ensuring their own food, clothing, housing and transportation, We aim for sustainable development to make the building and nature coordinate with each other and to create a healthier and more comfortable living space. This article analyzes the water resources in the construction process, discusses why they are wasted and how to reduce their waste In addition, a water-saving combination method will be proposed to optimize this situation.
The Technology and Application of Improving Bearing Capacity of Deep Peat Soil Subgrade
Authors: Cao Xiuling , Yue Muci , Xu Haiyan , Chen Song , Hou Yongkang , Wang Xingkuo
Published: June 2021

Peat soil is widely distributed in more than 500 countries around the world, covering an area of over 4 million square kilometers, among which the distribution area in China is about 40000 square kilometers, and most of Peat soil is distributed in swamps and forests. Peat soil is with high content of organic matter, poor engineering properties and low bearing capacity, which is very unfavorable to the safety and functionality of infrastructure construction. The Belt and Road, and the other two parts of the peat soil are studied in this paper. The key technologies of peat soil foundation are studied through literature review and comparative study. This will provide theoretical and technical support for repairing bridges, roads and houses in the distribution area of peat soil, and provide the theoretical basis and technical foundation for the construction of the “peat” Road area.

Chinese Library Classification: TU08
Study of PFS and PAC coagulation effect on Pi River water
Authors: Wang Wan-Fen
Published: June 2021

Using poly-aluminum chloride (PAC) and poly-ferric sulfate (PFS) as coagulants, the effects of the dosage of PAC and PFS on the removal of turbidity, chromaticity and UV254* in water were investigated by using the method of enhanced coagulation. The results show that when the raw water is neutral and the turbidity is less than 20NTU, and the pH value does not decrease much after coagulation and sedimentation, PAC and PFS are separately added to 7.5mg/l, 35mg/l. The removal rate of turbidity and chromaticity in the water sample can reach 83.75% and 48.47%, respectively, but the removal rate of UV254* is less than 30%, the mass ratio of PAC to PFS is 1:1 to 6:1, the removal efficiency of turbidity and Chroma increased by about 10%, but the removal efficiency of UV254* did not change or even decreased, both PFS and PAC can effectively remove the turbidity and Chroma in the micro polluted Pi River, but the removal effect of UV254* is not good, and the removal effect of PAC is better than PFS.
Assessment of spatial coupling coordination in the Three Gorges reservoir area- Taking Badong County as an example
Authors: Li Guiyuan , He Zhao
Published: June 2021

The special geographical location leads to the mutual restriction of urban spatial natural resources, material space and economy and society in the Three Gorges reservoir area, which threatens the spatial security of the towns. Based on the characteristics of multidimensional coupling between systems, this study uses Badong County as an example to evaluate the trend of coupling coordination between natural resources-material space-economic society and society by using the coupling coordination model. The results show that although the coupling degree between systems in Badong County is as high as 0.9546 and the degree of interaction is very strong, the degree of coupling coordination is only a moderate imbalance development type. Therefore, it is an urgent problem to improve the level of coupling and coordination between systems and ensure the safety of urban space.
Dynamic Characteristics Analysis and Experimental Verification of Long Span Suspension Bridge
Authors: Yang Guojun , Tian Qiwei , Tang Guangwu , Li Longlong , Ye Su , Du Yongfeng
Published: June 2021

The dynamic characteristics of long-span suspension bridges are complex. The natural vibration frequency is changed with different structural parameters, and the sensitivity to different parameters is different. In order to solve this problem, the spatial model of a long-span suspension bridge was established by using finite element software, and the first 20 natural vibration periods, natural vibration frequencies and vibration modes were analyzed and calculated. The accuracy of the obtained natural vibration frequency data was verified through field tests. Finally, based on the model, the stiffness of structural components is studied by one -factor-at-one-time, and the influence of various variables on the frequency and mode of a certain mode is studied by one-factor-at-one-time method. The results show that different structural parameters have different effects on the vibration frequency. When the stiffness of stiffening girder and main tower is changed, with the increase of stiffness, the variation of frequency mostly presents an upward trend, and the range is large. With the change of the secondary dead load, most of the frequencies decrease first and then tend to be stable. It can be seen from the field test results that the vibration shapes and frequencies measured by numerical simulation and test are close to each other, which can meet the requirements of engineering precision. The stiffness of the main cable and the main tower has a great influence on the modes and periods corresponding to them. The increase of the secondary dead load can reduce the natural vibration frequency of the suspension bridge, but it is not unlimited to increase the secondary dead load to reduce the frequency. The stiffness of the stiffening girder has a great influence on the frequency of the suspension bridge. When the bending stiffness of the stiffening girder increases to 3 times of the original one, the order of vibration modes of the structure will change. The research results can provide references for structural design and dynamic parameter adjustment of long-span suspension bridge.
Research on Industry Situation Changes and Development Strategies of New Energy Automobile Companies
Authors: Kong Chuiying , Men Feng , Sun Tian
Published: June 2021

This article sorts out the development of China’s new energy vehicle industry from three levels of policy, market and technology, and judges the development trend. At the policy level, R&D and innovation support policies, promotion fee policies, and going out policies will become development trends. At the market level, the future automobile market will gradually pick up and maintain a steady development trend. At the technical level, the level of three-electric technology and intelligent network technology will be further improved. On this basis, the company’s development strategy is analyzed in order to provide a reference for the development of new energy automobile companies.
Realization of Preventive Function of Environmental Law in the Governance of Risky Society: Based on the Article 39 of the “Environmental Protection Law of the People’s Republic of China”
Authors: Han Kangning , Zhang Shoucheng
Published: June 2021

The protection of public health is one of the legislative purposes of China’s environmental legal system. The “Environmental Protection Law” puts forward the legal goal of “establishing and improving the environment and health monitoring, investigation and risk assessment system”, and incorporates the environmental health risk assessment system into the environment Protect the scope of basic systems, but China’s existing environmental monitoring, environmental impact assessment, and environmental standards cannot achieve the functions of environmental and health risk prevention and regulation. It is necessary to build an environmental health risk assessment system with Chinese characteristics from both physical and procedural aspects.
Research and Application of Information Management of Quality Inspection Data in Bridge Construction
Authors: Wang X X , Zhang J D
Published: June 2021

Highway engineering quality inspection and evaluation is a key link in highway engineering construction project quality control, and efficient and effective is essential to quality inspection and evaluation. Combined with the quality inspection and assessment standards, a standardized standard library was formed, and the engineering division was improved to achieve refined engineering division and rationalized engineering division. Through the quality assessment and quality rectification, the whole process of assessment is completed, and the QR code visualization technology is used to match the quality inspection table to realize the information management of the quality inspection data and complete the system research and development. Finally, according to the specific engineering application, the efficiency of bridge engineering quality inspection and evaluation is improved, the evaluation data is effectively managed, and the system functions are fully verified.
The influence of human motion state on human-structure interaction
Authors: Han Zhifan , Lu Guohua , Li Rudong
Published: June 2021

Under pedestrian load, significant vibration and comfort problems are easy to arise for large-span low-frequency structures so that human-structure interaction should be considered in the design. However, different human motion states have different human modal parameters, which makes the design more difficult. The Spring-Mass-Damper (SMD) model is used to conduct numerical simulation experiments on 6 box beams with different fundamental frequencies in 4 different human motion states, based on which the dynamic characteristics of the structure under 30 working conditions are compared and analyzed. It is recommended to use the modal parameters of the standing human body in the vibration comfort design, and use the modal parameters of the human body at normal walking speed for the design of the low-frequency structure.
Study on Mechanical behavior and equivalent calculation of GFRP- stainless Steel Composite Truss Bridge
Authors: Hao Xianwu , Liu Yuan
Published: June 2021

GFRP is a kind of carbon fiber composite reinforced material, which has attracted wide attention in the engineering field because of its light weight, high strength, corrosion resistance and so on.The solid plate and shell finite element model of full GFRP truss bridge is established by ABAQUS, and its mechanical characteristics are analyzed. The study shows that the stress of each element is less than the material strength, but the mid-span deflection of the truss bridge exceeds the allowable value of the specification, so three kinds of stainless steel plate layout schemes are considered, and the structural gravity, mid-span deflection change and element stress are compared and analyzed. Finally, it is concluded that the upper and lower stainless steel plate has a great contribution to enhance the vertical stiffness of the GFRP truss bridge. The stainless steel plate largely replaces the upper chord under pressure and the lower chord is pulled. On this basis, the stainless steel plate beam filled between oblique bars is equivalent to the upper and lower chords by using the idea of average equivalence and the principle of equal mass. The finite element software analysis shows that the equivalent error is very small.
Simple Household Space Design Based on Soft Decoration of Furniture
Authors: Zhang Nini , Bu Leping , Meng Shaoqing
Published: June 2021

With the continuous development of China’s economy, people’s quality of life is constantly improving. As a matter of course, more and more attention is paid to home design. In particular, the space design of small apartments is welcomed by everyone. Among them, soft cloth decoration is a very popular form of home design now, which is very suitable for the design and use of small apartment. But the diversity of small family space brings difficulties to the design. The design and calculation of the simple home space in the small apartment with the RANSAC algorithm is fully satisfied with the requirements of the use of the algorithm and can achieve the accuracy of our calculation and facilitate communication with customers. The RANSAC algorithm has the powerful ability of image processing, which can help us to establish the visualization research of space design.
Influence of polyvinyl alcohol fiber and fly ash content on compressive creep properties of high ductility cementitious composites
Authors: Chen Bo , Guo Liping , Zhang Lihui , Zhang Wenxiao , Bai Yin , Wang Xiongfeng
Published: June 2021

The influence of polyvinyl alcohol (PVA) fiber volume fraction and fly ash content on the creep behavior of high ductility cementitious composites (HDCC) under compression was investigated. For this investigation, the creep behavior of four HDCC groups with cube compressive strength of 30–50 MPa, PVA fiber volume fraction of 1.5% and 2.0%, and fly ash content of 60% and 80% at 7 d and 28 d loading periods, respectively, were evaluated. A compressive creep model, which reflects the loading age and holding time, was established. The results revealed that when the load was applied at 7 d and 28 d, and then maintained for 245 d, the specific creep of HDCC ranged from 95×10-6/ MPa to 165×10-6/ MPa and from 59×10-6/ MPa to 135 × 10−6/ MPa, respectively. The corresponding creep coefficients ranged from 1.48 to 2.25 and from 1.10 to 1.94, respectively. The PVA fiber volume fraction and fly ash content were the main factors affecting the specific creep of HDCC, which increased with increasing fiber fraction and fly ash content. Under short-term loading, the fiber volume fraction played a leading role in the specific creep, and the fly ash content played the leading role during long-term loading. Furthermore, the specific creep and creep coefficient decreased significantly with increasing loading age. The classical creep model described by a power exponent function is suitable for HDCC.
Finite element analysis of floor slab of new type assembly structure system
Authors: Zhang Xiaomeng , Ding Weilun , Ren Qingying , Liu Wenting , Wang Qiaji
Published: June 2021

In this paper, a new type of prefabricated concrete structure system is put forward, and a new type of bi-directional multi-ribbed floor is put forward in combination with this system.Finite element analysis is carried out on the floor, and its mechanical properties are analyzed, and compared with the test hysteresis curve, the rationality and correctness of the finite element analysis are obtained.
Numerical simulation of shear capacity of lightweight aggregate concrete stud connectors
Authors: Lin Hao , Lei Liu , Jian Li
Published: June 2021

In order to study the mechanical properties of the stud connectors in lightweight aggregate concrete (LWAC), the finite element software ABAQUS was used to establish the push test models of ordinary concrete and LWAC, respectively. Through parameter analysis of 21 models, the influence of different parameters on the shear performance of LWAC stud connector was studied. Among them, concrete strength, stud diameter and stud strength have strong effects. Compared with stud connector in ordinary concrete, the LWAC stud connector enters the elastoplastic working stage earlier, the ultimate slip is slightly larger, the ductility is better, and the shear capacity is about 11% lower. Regression analysis was performed on the finite element calculation results, and the method for shear bearing capacity calculation of the stud connectors in LWAC is given.
The impact of the operation mode of CRACs on the temperature distribution of hot and cold aisles for the data center room
Authors: Liu Q , Huang J W , Chong L W , Zhang Z , Qi Z , Lu F K , Fan Y S , Zhang C , Dai N , Ruan Y , Wang Y X
Published: June 2021

Redundancy is generally considered in the computer room air conditioners (CRACs) of the data center room. The position of the CRAC in the on state and the operating air volume have a great influence on the temperature distribution. The temperature distribution of the data center room will affect the failure rate of the servers and the energy consumption of the air-conditioning system. Taking a typical data center room as an example, this paper uses numerical simulation to study the influence of the on/off state and air volume of CRACs on the temperature distribution of the hot and cold aisles and energy consumption. The calculation results show that we should preferably turn off the staggered CRACs on the opposite side and close to the middle position under the partial load. When the IT load is unevenly distributed, it is irrational to use the setting method of even distribution of the air volume of each CRAC. The air volume of each CRAC should be appropriately adjusted based on the distribution characteristic of IT load to reduce the energy consumption.
Experimental study on seismic behavior of full scale square concrete filled steel tubular stocky columns
Authors: Liu Jin , Jian Liang , Xiuli Du
Published: June 2021

This study mainly presented a pseudo-static experiment on two full-scale square CFST short columns with the cross-sectional width of 600 mm under combined constant axial load and cyclic lateral load. The seismic performance of the two full-scale CFST columns were investigated. Meanwhile, the plastic hinge length of the specimens was discussed. The test results presented that the specimens suffered bend-shear failure. The local buckling of steel tube occurred at the end of the specimens and the core concrete crushed. The safety redundancy of lateral bearing capacity decreased in full-scale specimen. By the method of physical observation, the plastic hinge length Lp1 was determined mainly according to the range of the local buckling of steel tube. There had a great difference between the prediction of plastic hinge lengths by the existing calculation model and the plastic hinge lengths obtained by the test.
Study on simulation mechanics and fatigue performance of steel bridge deck rigid flexible composite pavement
Authors: Li Yinshan , Liu Linlin , Li Tianyu , Guo Ruyong , Wu Chunying
Published: June 2021

Aiming at the fatigue cracking of steel bridge deck pavement and the shortage of river sand resources, a sea sand RPC pavement scheme was proposed. Taking Quanhe steel box girder bridge as the research background, the simulation model was established by using ANSYS finite element software, and the mechanical simulation analysis of the steel bridge deck sea sand RPC-asphalt pavement composite structure was carried out to determine the most unfavorable load position. A three-point fatigue test was carried out to study the fatigue performance of the structure specimen, and a comparative analysis was made with the river sand RPCasphalt surface composite pavement structure. The results show that the maximum tensile stress and strain of RPC-asphalt pavement appear in the upper middle span of U-shaped stiffener of steel box girder, which are 0.5241MPa and 98.2με, respectively, and the surface of the pavement in this area is prone to crack. The RPC-asphalt surface composite pavement structure has not been damaged after 2 million times of fatigue tests, and has not been damaged after 1 million times of fatigue loading after secondary loading, which indicates that it has better fatigue performance.
Use of MEMS sensors for condition monitoring of devices: discussion about the accuracy of features for diagnosis
Authors: D'Emilia Giulio , Natale Emanuela
Published: June 2021

This paper analyses the effect of the variability of metrological characteristics of a set of low-cost Micro Electro-Mechanical Systems (MEMS) for the acceleration measurement, on the calculation of typical features used for condition monitoring (CM) of automatic production lines. The knowledge of the contribution of the variability of metrological characteristics to the final accuracy of features is an aspect of interest when networks of low-cost sensors are used, in particular in case the variability of their characteristics is high. In fact, due to a mass production, the calibration is not carried out sensor by sensor, but the characteristics are determined on a sample basis and assigned to the entire batch. Neglecting the variability between sensors can lead to effects on the results of data analysis, which are not easily predictable. In this paper, the real variability of the sensor's characteristics, experimentally evaluated through the calibration of a set of 25 low-cost MEMS accelerometers, has been taken into account. Digital sensitivity, signal-to-noise ratio and data rate variability of each device have been considered for the analysis. The analysis has been carried out with reference to two different test cases of industrial interest, by modifying the real outputs of high performance piezoelectric accelerometers used for CM, in order to simulate the effect of the metrological characteristics of MEMS sensors. The results show which features, among those typically used for CM, are more affected and which characteristics of MEMS are more influencing the features themselves, with reference to the specific considered applications.
Developing intercultural and entrepreneurship competences among students – the case of business, IT, and services disciplines
Authors: Aškerc Zadravec Katarina
Published: June 2021

Developing intercultural and entrepreneurship competences provides future graduates with several benefits, wherein they are equipped for the globalized, intercultural world imbued with all of its uncertainties, diversities, and opportunities, both at the workplace and in everyday life. Entrepreneurial higher education institutions are characterized by an international and intercultural perspective – however, an institution cannot be entrepreneurial without being international, yet it can be international without being entrepreneurial. Entrepreneurial university provides a good environment, culture, and practices that enhance student entrepreneurship. Internationalisation, entrepreneurship, and in this context international entrepreneurship education are important topics to which academics and higher education institutions have increasingly devoted attention in recent years. This article discusses various aspects of developing intercultural and entrepreneurship competences, which are affected by different approaches to intercultural learning and teaching in the context of entrepreneurship education. In the last part of the paper, results are presented of quantitative research among Slovenian academics who teach business, IT, and services disciplines. Findings have shown that independent variables like teaching international students, providing distance learning with foreign institutions, inclusion of academics in training courses, and academics’ international mobility all influence the frequency of using intercultural and entrepreneurial aspects in higher education learning and teaching practices.
Factors of influence on performance of heat power industry enterprise
Authors: Karimov Hennadii , Zvonarova Kateryna , Karimov Ivan
Published: June 2021

Research into the factors influencing the performance of heat power industry enterprise is specific due to aspects of subordination and regulation of enterprises in the field of heat power engineering. Heat power plant (thermal power plant) is a typical representative of the heat power industry and it displays all the main characteristics of the industry. The conclusions of the PEST-analysis characterize the general factors influencing the heat and electricity market, i.e. the market of the discussed enterprise. According to the conclusions of the SWOT-analysis the paper determines the priority areas of enterprise development. The main step towards the intensification of the enterprise performance is a project aimed at raising the connected thermal capacity that will allow to reduce production costs (increasing the workload on equipment), improve social welfare for the city (creating new jobs and improving the quality of home heating) and boost interest of investors in the enterprise (growing profitability).
Vorhofflimmern – was wir nicht wissen („gaps in evidence“)
Authors: Wiedmann Felix , Schmidt Constanze
Published: June 2021

Auch nach Jahrzehnten intensiver grundlagenwissenschaftlicher und klinischer
Forschungsbemühungen können nicht alle Fragestellungen, die sich bei der Diagnosestellung und
Behandlung von Vorhofflimmern stellen, abschließend beantwortet werden. Das Konzept der
atrialen Kardiomyopathie unterstreicht, dass es sich bei Vorhofflimmern um keine einheitliche
Krankheitsentität handelt, sondern um einen Prozess, dem eine Vielzahl unterschiedlicher
Ursachen und Mechanismen zugrunde liegt. Noch nicht abschließend geklärt bleibt die hieraus
resultierende klinische Konsequenz. Neue Studienergebnisse weisen auf einen ausgeprägten
klinischen Benefit von rhythmuskontrollierenden Therapiestrategien, sowohl bei neu
diagnostiziertem paroxysmalem Vorhofflimmern als auch bei Herzinsuffizienzpatienten mit
Vorhofflimmern, hin und stellen damit erneut die Frage, ob Rhythmuskontrolle Frequenzkontrolle
vorzuziehen ist.
Entwicklung der Osteologie in der Praxis – Interdisziplinäre Qualitätszirkel und Bund der Osteologen
Authors: Defèr Alexander , Abendroth Klaus
Published: June 2021

Die Gründung von interdisziplinären Qualitätszirkeln Osteoporose erfolgte zur Verbesserung der Versorgung von Patientinnen und Patienten mit Osteoporose. Neben der Verbesserung der Versorgungsqualität war es uns ein wichtiges Anliegen, eine einheitliche Dokumentation zu entwickeln, um die Möglichkeit zu schaffen, die Qualität der Versorgung auch zu evaluieren. Neben der Idee zur Versorgungsforschung stand aber auch die Forderung der zertifizierten Osteologen DVO im Raum, in Versorgungsverträge mit der gesetzlichen Krankenversicherung einzutreten. Die dazu notwendige juristische Voraussetzung wurde mit der Gründung des Bundes der Osteologen als eingetragener Verein geschaffen.

Im Ergebnis dieser Entwicklung hat sich die Betreuungsqualität von Patientinnen und Patienten mit Osteoporose deutlich verbessert.
ESC-Leitlinie 2020 zum Vorhofflimmern: Was ist neu, was ist wichtig, was ist zu tun?
Authors: Eckardt Lars , Wolfes Julian , Ellermann Christian
Published: June 2021

Die aktuelle, 2020 erschienene Leitlinie der Europäischen Gesellschaft für Kardiologie zum
Management von Vorhofflimmern gibt eine sehr gute Übersicht und aktuelle Empfehlungen zur
Diagnostik und Therapie von Vorhofflimmern. Als Neuerung wurde das 4S-AF-Schema zur
Charakterisierung von Vorhofflimmern eingeführt. Es berücksichtigt das Schlaganfallrisiko, den
Schweregrad der Symptome, das Ausmaß der Vorhofflimmerlast und das elektrophysiologische
Substrat. Außerdem wurde mit dem ABC-Modell ein einprägsamer Therapieleitfaden eingeführt. Er
soll die strukturierte Behandlung von Patienten mit Vorhofflimmern erleichtern und umfasst die
Themen Antikoagulation/Schlaganfallprävention, bessere Symptomkontrolle und das Management
kardiovaskulärer Risikofaktoren sowie vorhandener Begleiterkrankungen. Die Empfehlungen zur
Antikoagulation und medikamentösen antiarrhythmischen Therapie haben sich in den aktuellen
Leitlinien nicht wesentlich geändert, wohingegen die Indikation zur Katheterablation
heraufgestuft wurde.
Vorhofflimmern und NOAK-Therapie: Benötigen wir eine transösophageale Echokardiografie vor Kardioversion?
Authors: Baumeister Timo-Benjamin , Helfen Andreas , Wickenbrock Ingo , Perings Christian
Published: June 2021

Vorhofflimmern ist ein häufiger Grund für einen Schlaganfall. Insbesondere Patienten ohne adäquate Antikoagulation haben ein erhöhtes Risiko für thromboembolische Ereignisse (ca. 5–7%). Es liegt eine Assoziation zwischen Kardioversionen und embolischen Ereignissen vor. Durch eine orale Antikoagulation (OAK) mit Nicht-Vitamin-K-Antagonisten (NOAK) kann dieses Risiko auf unter 1% reduziert werden. Es gibt 2 unterschiedliche Kardioversionsstrategien. Zum einen kann eine Kardioversion nach 3-wöchiger effektiver Antikoagulation ohne weitere Bildgebung durchgeführt werden. Zum anderen kann nach Ausschluss einer intrakardialen Thrombenbildung durch eine TEE umgehend sicher kardiovertiert werden. Bei Vorhofflimmern sollte nach der Kardioversion eine effektive Antikoagulation für mindestens 4 Wochen erfolgen, unabhängig vom CHA2DS2-VASc-Score. Eine Bildgebung mittels TEE ist notwendig, wenn die Dauer einer effektiven Antikoagulation <3 Wochen ist, Unsicherheiten bezüglich der regelmäßigen und lückenlosen Medikamenteneinnahme bestehen oder ein hohes Risiko für linksatriale Thromben besteht.
Recent Advances in Transition-Metal-Catalyzed C–H Functionalization Reactions Involving Aza/Oxabicyclic Alkenes
Authors: Jeganmohan Masilamani , Sihag Pinki
Published: June 2021

Bicyclic alkenes, including oxa- and azabicyclic alkenes, readily undergo activation with facial selectivity in the presence of transition-metal complexes. This is due to the intrinsic angle strain on the carbon–carbon double bonds in such unsymmetrical bicyclic systems. During the past decades considerable progress has been made in the area of ring opening of bicyclic strained rings by employing the concept of C–H activation. This short review comprehensively compiles the various C–H bond activation assisted reactions of oxa- and azabicyclic alkenes, viz., ring-opening reactions, hydroarylation, and annulation reactions.

1 Introduction

2 Reactions of Heterobicyclic Ring Systems

2.1 Ring-Opening Reactions of Oxa- and Azabenzonorbornadienes

2.1.1 Reactions Using 7-Oxabenzonorbornadienes

2.1.2 Reactions Using 7-Azabenzonorbornadienes

2.2 Hydroarylation Reactions

2.3 Annulation Reactions

2.4 Other Reactions

3 Conclusion
Dynamic Occlusion of Distal Ventriculoperitoneal Shunt Catheter after Infusion Port Placement: A New Shunt Malfunction
Authors: Carter Lacey M. , Milton Camille K. , O'Connor Kyle P. , Chakraborty Arpan R. , Stephens Tressie M. , Glenn Chad A.
Published: June 2021

Shunt failure requiring reintervention remains a common complication of hydrocephalus treatment. Here, we report a novel cause of mechanical shunt obstruction in an adult patient: position-dependent intermittent occlusion via an infusion port catheter. A 51-year-old woman with a grade II oligodendroglioma presented in a delayed fashion following surgery with a pseudomeningocele. She underwent ventriculoperitoneal shunt placement due to communicating hydrocephalus, resolving her pseudomeningocele. Shortly thereafter, she underwent placement of a subclavian infusion port at an outside institution. Her pseudomeningocele returned. Imaging demonstrated close proximity of her port catheter to the shunt catheter overlying the clavicle. Her shunt was tapped demonstrating a patent ventricular catheter with normal pressure. She underwent shunt exploration after her pseudomeningocele did not respond to valve adjustment. Intraoperative manometry demonstrated head position-dependent distal catheter obstruction. Repeat manometry following distal catheter revision demonstrated normal runoff independent of position. Her pseudomeningocele was resolved on follow-up. To our knowledge, this is the only reported case of intermittent, position-dependent distal catheter obstruction. Shunted patients with concern for malfunction following subclavian infusion port placement should be evaluated for possible dynamic obstruction of their distal catheter when the two catheters are in close proximity along the clavicle.
Spontaneous Hematomyelia Associated with the Use of Non–vitamin K Antagonist
Authors: Park Moon Soo , Moon Seong-Hwan , Jang Seung Bo , Kim Jeoung Woo , Sung Paul S.
Published: June 2021

Vitamin K antagonists have been frequently prescribed as anticoagulants with the potential side effect of spontaneous hematomyelia with a poor prognosis. However, to our knowledge, there has been no report of spontaneous hematomyelia combined with the use of a non–vitamin K antagonist. A 63-year-old man presented with left leg weakness, impaired sensation, and urinary retention while taking rivaroxaban (non–vitamin K antagonist) for 4 months for atrial fibrillation. Anticoagulant agents were discontinued. Methylprednisolone pulse therapy was administered without surgical hematoma evacuation. Three months after the initial development of the hematomyelia, the symptoms improved to grade 5 for both lower extremities, and there was complete recovery in sensory and urinary functions. This might be the first description of a complete recovery of neurologic deficits without hematoma evacuation in spontaneous hematomyelia patients caused by non–vitamin K antagonist therapy.
Human Codon Usage: The Genetic Basis of Pathogen Latency
Authors: Kanduc Darja
Published: June 2021

Infectious diseases pose two main compelling issues. First, the identification of the molecular factors that allow chronic infections, that is, the often completely asymptomatic coexistence of infectious agents with the human host. Second, the definition of the mechanisms that allow the switch from pathogen dormancy to pathologic (re)activation. Furthering previous studies, the present study (1) analyzed the frequency of occurrence of synonymous codons in coding DNA, that is, codon usage, as a genetic tool that rules protein expression; (2) described how human codon usage can inhibit protein expression of infectious agents during latency, so that pathogen genes the codon usage of which does not conform to the human codon usage cannot be translated; and (3) framed human codon usage among the front-line instruments of the innate immunity against infections. In parallel, it was shown that, while genetics can account for the molecular basis of pathogen latency, the changes of the quantitative relationship between codon frequencies and isoaccepting tRNAs during cell proliferation offer a biochemical mechanism that explains the pathogen switching to (re)activation. Immunologically, this study warns that using codon optimization methodologies can (re)activate, potentiate, and immortalize otherwise quiescent, asymptomatic pathogens, thus leading to uncontrollable pandemics.
Porous-Coated Metaphyseal Sleeves in Revision Total Knee Arthroplasty: Midterm Results
Authors: Stefani Giacomo , Mattiuzzo Valerio , Prestini Greta , Civitenga Carolina , Calafiore Roberto , Traverso Francesco
Published: June 2021

Purpose The aim of this study was to evaluate the efficacy in terms of clinical results and radiographic findings of using metaphyseal sleeves in revision total knee arthroplasty (TKA), and to check if the use of sleeves without stems did not impair such results.

Methods In this retrospective study, 141 patients (143 knees) operated in the period 2008 to 2015 met the above-mentioned criteria and were invited to a medical examination including X-rays. A total of 121 knees were available for the study (44 in the group without stems and 77 in the group with stems). Mean follow-up was 63 months for the stemless group and 89 for the group with stems. Knee Society Score (KSS) (objective knee score) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) were used as outcome scores and compared with baseline values, range of motion (ROM) was also compared with preop value and X-rays were also examined and compared with immediate postop X-rays to check signs of loosening and radiolucent lines, if any, and bone ingrowth. Satisfaction of the patients was also investigated using a linear scale from 1 to 10.

Results KSS improved from 34 to 81 postop (39 to 81 in the stemless group) (p < 0.01), while WOMAC from 82% preop to 39% postop (76 to 37% in the stemless group) (p < 0.01). Forty-six patients were satisfied, 20 partially satisfied, and 11 unsatisfied (respectively 25–14–5 in the stemless group). ROM improved from 89 degrees preop to 99 degrees postop (93 to 98 degrees in the stemless group). X-rays showed no loosening of the implant, radiolucent lines in 8 patients, and bone ingrowth in 113 out of 121 patients.

Conclusion In this midterm follow-up study, we found a significant improvement in clinical results compared with preop values. We found no difference between the two groups (with and without stems) thus suggesting that the use of stemless sleeves does not impair results in revision TKA.

Level of Evidence Therapeutic case series, level IV.
The psychosocial implications of social distancing for people with COPD: some exploratory issues facing a uniquely marginalised group during the COVID-19 pandemic
Authors: Yoeli Heather
Published: June 2021

Chronic obstructive pulmonary disease (COPD) is an illness associated with intersectional poverty and stigma in old age; people with COPD are susceptible to anxiety, loneliness and isolation. People with COPD who contract COVID-19 are at high risk of serious complications, intensive medical needs and death and are, therefore, required to socially distance particularly assiduously. This paper offers an embodied phenomenological analysis of the emerging theoretical literature exploring the impact of social distancing upon people with COPD. Firstly, people with COPD are aware of how respiratory illness feels, are anxious about COVID-19 and afraid of being denied care. Future research might consider how people with COPD may be susceptible to “coronaphobia” and mental health consequences of the pandemic. Secondly, COPD tends to affect older people within the most intersectionally marginalised socioeconomic groups. Future research should remain mindful that people with COPD may be among the most lonely and least able to access health and social care services online than others. Thirdly, pandemics are known to intensify pre-existing social stigmas. Researchers and practitioners alike should be conscious that people with COPD may become increasingly stigmatised, especially those from intersectionally disadvantaged minorities.
A non-invasive imaging technique for studying soil-based carbon sequestration
Authors: Yiu Yuen
Published: June 2021

Researchers present an all-digital associated particle imaging device with angular and depth resolution useful for soil carbon studies.
Correlation of anomalous Hall effect with structural parameters and magnetic ordering in Mn3+xSn1−x thin films
Authors: Yoon Ju-Young , Takeuchi Yutaro , DuttaGupta Samik , Yamane Yuta , Kanai Shun , Ieda Jun’ichi , Ohno Hideo , Fukami Shunsuke
Published: June 2021

We investigate the relationship between structural parameters, magnetic ordering, and the anomalous Hall effect (AHE) of Mn3+xSn1−x (−0.42 ≤ x ≤ +0.23) thin films annealed at various temperatures Ta. The crystal structure changes with x and Ta, and at Ta ≥ 500 °C near the stoichiometric composition (−0.08 ≤ x ≤ +0.04), epitaxial single-phase D019-Mn3+xSn1−x(101̄0) is obtained. At room temperature, a larger AHE is obtained when the single-phase epitaxial Mn3Sn with the lattice constant closer to that of bulk is formed. The temperature dependence of the AHE shows different behaviors depending on Ta and can be explained by considering the variation of magnetic ordering. A close inspection into the temperature and composition dependence suggests a variation of magnetic phase transition temperature with composition and/or a possible correlation between the AHE and Fermi level position with respect to the Weyl points. Our comprehensive study on (101̄0)-oriented epitaxial Mn3Sn thin films would provide the basis for utilizing the unique functionalities of non-collinear antiferromagnetic materials.
Numerical simulation of coupled arc-droplet-weld pool behaviors during compound magnetic field assisted gas metal arc welding
Authors: Wang Lin , Chen Ji , Zhang Shiliang , Wu ChuanSong
Published: June 2021

A compound external magnetic field (EMF) can be used to prevent weld bead defects by controlling the metal transfer and arc behaviors during high-speed gas metal arc welding. A unified model containing the filler metal, arc, weld pool, and compound EMF was established to study the effect of the compound EMF on the welding process. The heat and mass transfer among the filler metal, arc, and weld pool under the action of the EMF was numerically analyzed. The simulation results showed that the high-temperature region in the molten pool was reduced and the temperature distribution was more uniform after the EMF was introduced. The speed of the forward liquid metal flow in the front of the molten pool increased due to the forward inclination of the filler metal and arc plasma, and a small metal bulge formed at the leading edge of the molten pool. Because of the periodic swing of the arc and the droplet, the transverse filling of the liquid metal strengthened. The generated additional electromagnetic force inside the weld pool was analyzed, and it had limited impact on the weld pool behavior.
Numerical investigation of droplet impact on a solid superhydrophobic surface
Authors: Li Wen , Wang Jingxin , Zhu Chuling , Tian Linlin , Zhao Ning
Published: June 2021

The impact of microscale water droplets onto a solid superhydrophobic surface is numerically investigated. The multiphase problems are modeled by the three-dimensional incompressible Navier–Stokes equations and the liquid–gas interface is captured by the level set method. The numerical model is verified with our experimental impact results via the comparison of spreading factor ξ, which is defined as the ratio of the wetted surface area to droplet initial diameter. The simulation results suggest that when the droplet impacts with constant impact velocity and diameter, the maximum spreading parameter increases with the ambient temperature. As Weber and Reynolds numbers increase, the impact turns into doughnut-breakup regime; the droplet breaks up into a toroidal shape and a cavity is formed at the center. The results indicate that the diameter of the central cavity grows linearly related to the non-dimensional time. Finally, a new droplet impact spread/splash model that is governed by Weber and Reynolds numbers is proposed for superhydrophobic surface based on our numerical and experimental results.
Analysis of the optical response of a SARS-CoV-2-directed colorimetric immunosensor
Authors: Minopoli Antonio , Scardapane Emanuela , Acunzo Adriano , Campanile Raffaele , Della Ventura Bartolomeo , Velotta Raffaele
Published: June 2021

The optical response of different configurations of functionalized gold nanoparticles (f-AuNPs) and SARS-CoV-2 virions is simulated in order to explore the behavior of a colloidal solution containing 105–1013 virions/ml. The analysis herein reported is carried out for three concentration regimes: (i) low (≲108 virions/ml), (ii) intermediate (∼109–1010 virions/ml), and (iii) high (≳1011 virions/ml). Given the high binding effectiveness of f-AuNPs to virions, three different configurations are expected to arise: (i) virions completely surrounded by f-AuNPs, (ii) aggregates (dimers or trimers) of virions linked by f-AuNPs, and (iii) single f-AuNP surrounded by virions. It is demonstrated that 20 nm diameter gold nanoparticles functionalized against all three kinds of SARS-CoV-2 proteins (membrane, envelope, and spike) allow one to reach a limit of detection (LOD) of ∼106 virions/ml, whereas the use of only one kind of f-AuNP entails a ten-fold worsening of the LOD. It is also shown that the close proximity (∼5 nm) of the f-AuNP to the virions assumed throughout this analysis is essential to avoid the hook effect, thereby pointing out the importance of realizing an apt functionalization procedure that keeps thin the dielectric layer (e.g., proteins or aptamers) surrounding the gold nanoparticles.
Ultrafast amplitude modulation for molecular and hemodynamic ultrasound imaging
Authors: Rabut Claire , Wu Di , Ling Bill , Jin Zhiyang , Malounda Dina , Shapiro Mikhail G.
Published: June 2021

Ultrasound is playing an emerging role in molecular and cellular imaging thanks to new micro- and nanoscale contrast agents and reporter genes. Acoustic methods for the selective in vivo detection of these imaging agents are needed to maximize their impact in biology and medicine. Existing ultrasound pulse sequences use the nonlinearity in contrast agents' response to acoustic pressure to distinguish them from mostly linear tissue scattering. However, such pulse sequences typically scan the sample using focused transmissions, resulting in a limited frame rate and restricted field of view. Meanwhile, existing wide-field scanning techniques based on plane wave transmissions suffer from limited sensitivity or nonlinear artifacts. To overcome these limitations, we introduce an ultrafast nonlinear imaging modality combining amplitude-modulated pulses, multiplane wave transmissions, and selective coherent compounding. This technique achieves contrast imaging sensitivity comparable to much slower gold-standard amplitude modulation sequences and enables the acquisition of larger and deeper fields of view, while providing a much faster imaging framerate of 3.2 kHz. Additionally, it enables simultaneous nonlinear and linear image formation and allows concurrent monitoring of phenomena accessible only at ultrafast framerates, such as blood volume variations. We demonstrate the performance of this ultrafast amplitude modulation technique by imaging gas vesicles, an emerging class of genetically encodable biomolecular contrast agents, in several in vitro and in vivo contexts. These demonstrations include the rapid discrimination of moving contrast agents and the real-time monitoring of phagolysosomal function in the mouse liver.