bluuebunny/crossref_metadata_2025 huggingface dataset:
ANALYSIS OF AUTONOMY FACTOR OF ENTREPRENEURSHIP INTENTION WITH REFERENCE TO STUDENTS OF SELECTED UNIVERSITIES OF NORTH-INDIA
Authors: Mahajan Tusshar , Arora Vikas
Published: April 2019

Entrepreneurship leads to economic growth and social development. Entrepreneurship is a risk-taking activity which needs dedication and focused approach. In case of students, starting a new venture is not an easy task, due to inclusion of high risk and uncertain future. There are many factors that trigger Entre-preneurship Intention of students; Autonomy is one such factor. The present study analyzed autonomy factor of entrepreneurship intentions of students with reference to North-India region. Students were found to have more inclination towards entrepreneurship with respect to autonomy factor. The study implied that Non-Metropolitan area students and especially Non-Metropolitan female students are more inclined towards entrepreneurship due to aspiration of autonomy.
RELIGIOSITY, FINANCIAL KNOWLEDGE, AND FINANCIAL BEHAVIOR INFLUENCE ON PERSONAL FINANCIAL DISTRESS AMONG MILLENNIAL GENERATION
Authors: Lajuni Nelson , Bujang Imbarine , Karia Abd. Aziz , Yacob Yusman
Published: April 2019

This study attempts to examine the personal financial distress among Malaysians millennial generation by scrutinizing religiosity, financial knowledge, and financial behavior as the influencing antecedents. The study adopted social learning theory (SLT) to underpin and explain the conceptual framework. The data were collected from millennial generations in Malaysia and analysed using Partial Least Squares Structural Equation Modelling. The findings suggest that all claimed hypotheses were partially supported. Implication and contribution of the study were later discussed to justify the significance of this research. The findings revealed that behavioral traits to have a stronger impact on the incidence of personal financial distress than religiosity or financial knowledge. The results suggested the government should implement policy that could be oriented towards improving the financial habits and mitigating the impact of behavioral characteristics on personal finances
EXAMINING THE EFFECT OF PRODUCT ASSORTMENT AND PRICE DISCOUNT TOWARD ONLINE PURCHASE DECISION OF UNIVERSITY STUDENT IN INDONESIA
Authors: Amanah Dita , Harahap Dedy Ansari
Published: April 2019

This study investigated the effect of product assortment and price discount on online purchase decision among university student in Indonesia. Ninety samples were employed which is students who had made an online purchase for fashion products. Purposive sampling has been applied as a sampling technique in this study. The results revealed that product assortment affected significantly to student online purchase decision. However, price discount did not affect significantly to online purchase decision. The limitation is only to test two variables of price discount and product diversity. Further studies are encouraged to consider other variables in determining online purchasing decisions such as trust, reputation, attractiveness of posting messages.
Biased recipients encounter biased sources: Effect of ethical (dis‐)agreement between recipient and author on evaluating scientific claims
Authors: Scharrer Lisa , Stadtler Marc , Bromme Rainer
Published: April 2019

Scientific claims that are connected to ethical concerns are frequently brought forward by communicators who are not ethically neutral. This study investigated how far recipients' evaluation of such claims is guided by vigilance toward a potential ethical source bias rather than their own ethical bias. One hundred ten individuals opposed to capital punishment read a topic‐related text by an ethically positioned source. A scientific claim in the text either supported or did not support the recipient's ethical stance; in addition, the source either shared or opposed their stance. Results showed that recipients are guided to some extent by their own ethically motivated reasoning: They agree more consistently with sources sharing their ethical stance and consider these sources to be more credible. Recipients appear to be principally aware that a source's ethical stance may bias its scientific message, but this vigilance seems to depend on their own ethical disagreement with the source.
Persistent Regulation of Tumor Microenvironment via Circulating Catalysis of MnFe2O4@Metal–Organic Frameworks for Enhanced Photodynamic Therapy
Authors: Yin Sheng‐Yan , Song Guosheng , Yang Yue , Zhao Yan , Wang Peng , Zhu Long‐Min , Yin Xia , Zhang Xiao‐Bing
Published: April 2019

Reactive oxygen species (ROS)‐based cancer therapy, such as photodynamic therapy (PDT), is subject to the hypoxia and overexpressed glutathione (GSH) found in the tumor microenvironment (TME). Herein, a novel strategy is reported to continuously and simultaneously regulate tumor hypoxia and reducibility in order to achieve the desired therapeutic effect. To accomplish this, a biocompatible nanoplatform (MnFe2O4@metal–organic framework (MOF)) is developed by integrating a coating of porphyrin‐based MOF as the photosensitizer and manganese ferrite nanoparticle (MnFe2O4) as the nanoenzyme. The synthetic MnFe2O4@MOF nanoplatform exhibits both catalase‐like and glutathione peroxidase‐like activities. Once internalized in the tumor, the nanoplatform can continuously catalyze H2O2 to produce O2 to overcome the tumor hypoxia by cyclic Fenton reaction. Meanwhile, combined with the Fenton reaction, MnFe2O4@MOF is able to persistently consume GSH in the presence of H2O2, which decreases the depletion of ROS upon laser irradiation during PDT and achieves better therapeutic efficacy in vitro and in vivo. Moreover, the nanoplatform integrates a treatment modality with magnetic resonance imaging, along with persistent regulation of TME, to promote more precise and effective treatment for future clinical application.
A General Layer‐by‐Layer Printing Method for Scalable High‐Resolution Full‐Color Flexible Luminescent Patterns
Authors: Zhao Cong , Li Huizeng , Wang Yang , Li Kaixuan , Hou Jue , Ma Ying , Li Mingzhu , Song Yanlin
Published: April 2019

High‐resolution scalable and colorful flexible luminescent patterns are prepared through an alternate printing method in a layer‐by‐layer (LBL) manner without any patterned substrates or masks. The novel embedding self‐assembly process retains high resolution to the sub‐micrometer level. This method is applied to achieve high‐resolution red, green, and blue (RGB) pixel array patterns, standard white light patterns, and various cross‐typed patterns. The fabricating process is flexible and straightforward, making it useful for diverse applications in patterning nanocomposites for wearable optoelectronic devices.
ZIF‐8 membrane synthesized via covalent‐assisted seeding on polyimide substrate for pervaporation dehydration
Authors: Zhao Xiaoxu , Zhang Hao , Xu Sheng , Wang Yan
Published: April 2019

In this study, a novel covalent‐assisted seeding method is developed to fabricate well‐intergrown ZIF‐8 membrane on polyimide (PI) substrate with imidazole‐2‐carboxaldehyde (ICA) as the covalent agent between ZIF‐8 layer and PI substrate. Compared to ethylenediamine‐crosslinked PI membrane and ZIF‐8/PI membrane synthesized without covalent‐assisted seeding method, ZIF‐8/PI membrane synthesized with ICA covalent‐assisted seeding method shows improved pervaporation performance for isopropanol dehydration. Subsequent surface coating with polydimethylsiloxane or polydopamine is applied to mitigate the grain boundary of ZIF‐8/PI membrane, which results in a further performance enhancement. The morphologies and physicochemical properties of the resultant membranes are characterized by scanning electron microscope, attenuated total reflectance‐Fourier transform infrared, X‐ray diffraction, and water contact angle. The effect of operation temperature on the separation performance is also carried out. This work demonstrates the novel covalent‐assisted seeding method for the preparation of ZIF‐8 membrane with high‐performance, which may hold a great potential for various ZIF membranes separation applications.
Organokatalytische, enantioselektive Dichlorierung unfunktionalisierter Alkene
Authors: Wedek Volker , Van Lommel Ruben , Daniliuc Constantin G. , De Proft Frank , Hennecke Ulrich
Published: April 2019

Der Einsatz einer neuen Klasse unsymmetrischer Chinaalkaloid‐basierter, Phthalazin‐verbrückter Organokatalysatoren ermöglichte die hoch enantioselektive Dichlorierung von unfunktionalisierten Alkenen. In Kombination mit dem elektrophilen Chlorierungsmittel 1,3‐Dichlor‐5,5‐dimethylhydantoin (DCDMH) und Triethylsilylchlorid (TES‐Cl) als nukleophiler Chloridquelle wurden 1‐Aryl‐2‐alkylalkene mit Enantioselektivitäten von bis zu 94:6 er dichloriert. Erste mechanistische Untersuchungen deuten darauf hin, dass kein freies Chlor gebildet wird. Das Ersetzen von Chlorid durch Fluorid ermöglichte die enantioselektive Chlorfluorierung von Alkenen.
Supramolecular Fe3O4@PEG/−diaza crown ether@Ni: a novel magnetically reusable nano catalyst for the clean synthesis of 2‐aryl‐2,3‐dihydroquinazolin‐4(1H)‐ones
Authors: Aalinejad Michael , Noroozi Pesyan Nader , Heidari Nosrat , Batmani Hana , Danandeh Asl Aria
Published: April 2019

Ni@diaza crown ether complex supported on magnetic nanoparticle was provided by grafting technique. The catalytic activity of Fe3O4@diaza crown ether@Ni was explored through one‐pot synthesis of 2,3‐dihydroquinazolin‐4(1H)‐ones and it was used as an efficient and recoverably constant nanocatalyst. FT‐IR, SEM, TEM, XRD, BET, ICP, EDS, and TGA techniques were employed to specify the nanocatalyst. This heterogeneous catalyst demonstrated acceptable recyclability and could be used again several times with no considerable loss of its catalytic activity.
Phosphotungstic acid grafted zeolite imidazolate framework as an effective heterogeneous nanocatalyst for the one‐pot solvent‐free synthesis of 3,4‐dihydropyrimidinones
Authors: Tayebee Reza , Fattahi Abdizadeh Mojtaba , Erfaninia Nasrin , Amiri Amirhassan , Baghayeri Mehdi , Kakhki Roya Mohammadzadeh , Maleki Behrooz , Esmaili Effat
Published: April 2019

Phosphotungstic acid (H3PW12O40, PTA) supported on ZIF‐9(NH2) was synthesized for the first time and performed as an effective and environmental friendly catalyst in the one‐pot three component Biginelli condensation of different substituted benzaldehydes with ethyl acetoacetate and urea to afford the corresponding 3,4‐dihydropyrimidin‐2‐(1H)‐ones under solvent‐free conditions. ZIF‐9(NH2) and the prepared nanocatalyst PTA@ZIF‐9(NH2) were characterized by XRD, FESEM, TEM, EDX, BET, AAS, TGA, UV–Vis, and FT‐IR. After reaction, the nanocatalyst can be easily separated from the reaction mixture by centrifuge and the recovered catalyst can be reused for at least five times with a 14% reduction in yield after the fifth run. This study showed that ZIF‐9(NH2) can be utilized as a promising support for PTA and developed a highly active, stable and reusable heterogeneous catalyst under easy reaction condition in the multi‐component organic synthesis.
Environmental and techno‐economic evaluation of β‐carotene production from Dunaliella salina. A biorefinery approach
Authors: Espada Juan J. , Pérez‐Antolín Daniel , Vicente Gemma , Bautista Luis F. , Morales Victoria , Rodríguez Rosalía
Published: April 2019

In this work, a solvent‐based extraction procedure and a procedure using supercritical CO2 to obtain β‐carotene from Dunaliella salina were compared from environmental and economic perspectives. Both processes were simulated using a biorefinery scheme in which β‐carotene was obtained and the waste biomass was used to produce energy. The results were used to carry out a life‐cycle assessment (LCA). The LCA results showed that a supercritical process was better in terms of energy consumption and greenhouse gas emissions. However, the low extraction yield of this technology makes it necessary to use large amounts of nutrients, whose production increases toxicity‐related impacts related to organic solvent extraction. This also affects the β‐carotene price, which is twofold higher in the case of a supercritical extraction process‐based biorefinery. The results therefore indicate that the potential benefits of the supercritical process in terms of environmental issues do not balance the drawbacks related to its low extraction yield. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd
Production of 2,5‐furandicarboxylic acid (FDCA) from starch, glucose, or high‐fructose corn syrup: techno‐economic analysis
Authors: Dessbesell Luana , Souzanchi Sadra , Venkateswara Rao Kasanneni Tirumala , Carrillo Alejandro Alarcon , Bekker Devon , Hall Kristen Amanda , Lawrence Katherine Mary , Tait Carolyn Lindsay Judge , Xu Chunbao (Charles)
Published: April 2019

This paper presents a techno‐economic analysis of a low‐cost and high‐efficiency technology for the production of 2,5‐furandicarboxylic acid (FDCA) from starch, glucose, or high‐fructose corn syrup (HFCS). With the design presented here, it is viable to convert starch to glucose through enzymatic hydrolysis followed by catalytic dehydration of glucose with niobium phosphate, an innovative low‐cost catalyst, to produce 5‐hydroxymethyl furfural (HMF). The HMF produced is then converted into FDCA via air oxidation over a cobalt‐manganese mixed oxide catalyst. Three variations of this design are assessed: Scenario 1 starts with starch, and Scenarios 2 and 3 start directly with glucose or HFCS, without the initial starch hydrolysis step. The minimum selling price (MSP) and discounted payback period (PBP) were calculated to investigate the feasibility of the scenarios. A sensitivity analysis was also performed for the key cost drivers, selling price of FDCA, and spent catalysts. All scenarios were feasible; however, the HFCS to FDCA process was the most profitable (MSP 1802 US$/t and a PBP below 5 years). Above all, the feasibility of this technology is mostly affected by variations in recovered catalysts and FDCA selling prices. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.
Predicting recurrence of papillary thyroid cancer using the eighth edition of the AJCC/UICC staging system
Authors: Chereau N , Oyekunle T O , Zambeli-Ljepović A , Kazaure H S , Roman S A , Menegaux F , Sosa J A
Published: April 2019

Background

The AJCC/UICC classification is widely used for predicting survival in papillary thyroid cancer (PTC), but has not been evaluated as a predictor of recurrence. The hypothesis of this study was that the eighth edition of the AJCC system can be used in this novel way.

Methods

All patients in the study underwent surgery for PTC at a high-volume endocrine surgery centre in France between 1985 and 2015. The seventh and eighth editions of the AJCC/UICC staging system for PTC were employed to predict recurrence and disease-specific survival using the Kaplan–Meier and log rank tests.

Results

Among 4124 patients (79·7 per cent female), median age was 50 (i.q.r. 38–60) years; 3906 patients (94·7 per cent) underwent total thyroidectomy, with lymph node dissection in 2495 (60·5 per cent). The eighth edition of the AJCC/UICC staging system placed 91·8, 7·1, 0·4 and 0·7 per cent of patients in stages I–IV respectively. After reclassifying patients from the seventh to the eighth AJCC/UICC edition, the disease was downstaged in 23·8 per cent. Over a median follow-up of 7 years, 260 patients (6·4 per cent) developed recurrent disease, including 5·2 per cent of patients with stage I, 19·6 per cent with stage II, 59 per cent with stage III and 50 per cent with stage IV disease, according to the eighth edition. The eighth edition was a better predictor of recurrence than the seventh edition.

Conclusion

The eighth edition of the AJCC/UICC staging system appears to be a novel tool for predicting PTC recurrence, which is a meaningful outcome for this indolent disease. The eighth edition can be used to risk-stratify patients, keeping in mind that other molecular and pathological predictive factors must be integrated into the assessment of recurrence risk.
Costs and quality of life in a randomized trial comparing minimally invasive and open distal pancreatectomy (LEOPARD trial)
Authors: van Hilst J , Strating E A , de Rooij T , Daams F , Festen S , Groot Koerkamp B , Klaase J M , Luyer M , Dijkgraaf M G , Besselink M G , van Santvoort H C , de Boer M T , Boerma D , van den Boezem P B , van Dam R M , Dejong C H , van Duyn E B , van Eijck C H , Gerhards M F , de Hingh I H , Kazemier G , de Kleine R H , van Laarhoven C J , Patijn G A , Steenvoorde P , Suker M , Hilal M Abu
Published: April 2019

Background

Minimally invasive distal pancreatectomy decreases time to functional recovery compared with open distal pancreatectomy, but the cost-effectiveness and impact on disease-specific quality of life have yet to be established.

Methods

The LEOPARD trial randomized patients to minimally invasive (robot-assisted or laparoscopic) or open distal pancreatectomy in 14 Dutch centres between April 2015 and March 2017. Use of hospital healthcare resources, complications and disease-specific quality of life were recorded up to 1 year after surgery. Unit costs of hospital healthcare resources were determined, and cost-effectiveness and cost–utility analyses were performed. Primary outcomes were the costs per day earlier functional recovery and per quality-adjusted life-year.

Results

All 104 patients who had a distal pancreatectomy (48 minimally invasive and 56 open) in the trial were included in this study. Patients who underwent a robot-assisted procedure were excluded from the cost analysis. Total medical costs were comparable after laparoscopic and open distal pancreatectomy (mean difference €–427 (95 per cent bias-corrected and accelerated confidence interval €–4700 to 3613; P = 0·839). Laparoscopic distal pancreatectomy was shown to have a probability of at least 0·566 of being more cost-effective than the open approach at a willingness-to-pay threshold of €0 per day of earlier recovery, and a probability of 0·676 per additional quality-adjusted life-year at a willingness-to-pay threshold of €80 000. There were no significant differences in cosmetic satisfaction scores (median 9 (i.q.r. 5·75–10) versus 7 (4–8·75); P = 0·056) and disease-specific quality of life after minimally invasive (laparoscopic and robot-assisted procedures) versus open distal pancreatectomy.

Conclusion

Laparoscopic distal pancreatectomy was at least as cost-effective as open distal pancreatectomy in terms of time to functional recovery and quality-adjusted life-years. Cosmesis and quality of life were similar in the two groups 1 year after surgery.
Vulnerable neoatherosclerosis in coronary artery with whole circumference showing intravascular echo attenuation
Authors: Hirota Yukiho , Nomura Tetsuya , Ono Kenshi , Sakaue Yu , Ueno Daisuke , Hori Yusuke , Yoshioka Kenichi , Kikai Masakazu , Keira Natsuya , Tatsumi Tetsuya
Published: April 2019

Key Clinical Message

Neoatherosclerosis is emerging as a stent‐associated problem that has not yet been fully resolved. Because in‐stent restenosis with a neoatherosclerotic etiology is associated with a high risk of acute coronary syndrome and a poor survival prognosis, it is essential to precisely identify patients at risk using advanced imaging modalities.
Wolff‐Parkinson‐White, Brugada phenocopy, and flecainide toxicity: All in one patient
Authors: Alhaj Eyad K. , Banning Michael , Vasaiwala Smit C. , Santucci Peter A.
Published: April 2019

Key Clinical Message

Accessory pathway Wolff‐Parkinson‐white is sometimes not manifested till later in life, as the conduction properties of AV node become slower, other mechanisms are also possible. Brugada pattern on EKG can be associated with various underlying clinical conditions, such as mechanical compression of RVOT by tumors. It is essential to have high index of suspicion for flecainide toxicity when encountering arrhythmias in patients taking the drug.
Ultra‐Small Molybdenum Carbide Nanoparticles in situ Entrapped in Mesoporous Carbon Spheres as Efficient Catalysts for Hydrogen Evolution
Authors: Yuan Shisheng , Xu Shaonan , Liu Zhipeng , Huang Guoqing , Zhang Cong , Ai Jing , Li Xiaotian , Li Nan
Published: April 2019

Developing cost‐effective and highly active hydrogen evolution reaction (HER) electrocatalysts is of pivotal importance in the roadmap of hydrogen economy. Increasing active sites and improving conductivity are two effective strategies to optimize the performance of electrocatalyst. In this paper, we report a highly active HER catalyst consisting of ultra‐small molybdenum carbide nanoparticles uniformly entrapped in mesoporous carbon microspheres (Mo2C@MCS) fabricated by in situ synthesis. In 1 M KOH, the catalyst exhibits an excellent HER performance with a pretty low overpotential (134 mV at current density of 10 mA cm−2) and a small Tafel slope (51 mV dec−1), which exceeded the currently reported un‐doped Mo2C catalyst. The excellent HER performance is attributed to the abundant active sites provided by the ultra‐small Mo2C nanoparticles as well as the superior conductivity originated from carbon matrix and the intimate contact between Mo2C nanoparticles and mesoporous carbon wall.
Exploiting Natural Complexity: Synthetic Terpenoid‐Alkaloids by Regioselective and Diastereoselective Hydroaminoalkylation Catalysis
Authors: DiPucchio Rebecca C. , Rosca Sorin‐Claudiu , Athavan Gayathri , Schafer Laurel L.
Published: April 2019

We report a catalytic and atom‐economic approach for the addition of N‐methyl groups to unactivated alkene‐containing terpenes to generate a library of synthetic terpenoid‐alkaloids. This catalysis was accomplished using Ta(CH2SiMe3)3Cl2 in combination with a new chiral ureate salt for highly chemo‐, regio‐, and diastereoselective hydroaminoalkylation reactions. The desired products are easily isolated and purified from unreacted starting materials to give aminated terpenes in one catalytic step. Starting material enantiopurity is completely retained, and stereoselective catalysis results to give enantiopure products. Absolute stereochemistry was determined by X‐ray crystallography and is consistent with regio‐ and stereoselective alkene insertion into a catalytically active tantallaziridine intermediate.
The Mechanism of Oxidation of Formic Acid in Acidic Solutions on Boron‐Doped Diamond Electrodes: A Quantum Chemical Study
Authors: Ignaczak Anna , Adamiak Marta , Santos Elizabeth , Schmickler Wolfgang
Published: April 2019

The oxidation of formic acid (syn‐FA and anti‐FA forms) by hydroxyl radicals generated on the boron‐doped diamond anode in acidic aqueous solution is examined by means of quantum chemical calculations under the assumption that the reaction proceeds according to the outer sphere mechanism, without adsorption of reactants on the electrode. A number of possible reactive complexes [FA ⋅⋅⋅ HO] and product complexes [COOH ⋅⋅⋅ H2O] formed in solution, as well as the corresponding transition‐state structures, were optimized at the MP2/aug‐cc‐pVTZ theory level, followed by single‐point CCSD(T) calculations. It is shown that in aqueous solution the formyl hydrogen abstraction is energetically favored and associated with the effective barriers ΔHb of 0.1–0.2 eV, which are about two times lower than that for carboxylic hydrogen abstraction. The overall reaction is highly exothermic (ΔH of about −5.8 eV) and expected to be very fast. The results confirm the validity of our hypothesis that the electrochemical incineration of formic acid may occur in solution according to the outer sphere mechanism.
Protamine Promotes Direct Electron Transfer Between Shewanella Oneidensis Cells and Carbon Nanomaterials in Bacterial Biocomposites
Authors: Pinck Stéphane , Jorand Frédéric P. A. , Xu Mengjie , Etienne Mathieu
Published: April 2019

Invited for this month's cover picture is the group of Dr. Mathieu Etienne from Centre National de la Recherche Scientifique (CNRS, France). The cover picture shows the building block of the bacterial biocomposite made of Shewanella oneidensis, multi‐walled carbon nanotubes, and protamine. The close look at the bacterial membrane shows how protamine, which is positively charged (in blue), promotes self‐assembly between the negatively charged polymers on the bacterial membrane surface (in red) and the negative surface of multi‐walled carbon nanotubes, allowing direct electron transfer reactions. The background of the image is a detail of a scanning electron microscopy image of the biocomposite deposited on a glassy carbon surface, forming the so‐called electroactive artificial biofilm. Read the full text of the Article at 10.1002/celc.201801751.
Anprall an Verkehrszeichenbrücken – Bewertung der Anpralllasten
Authors: Braml Thomas , Romen Norbert , Petry Sarah
Published: April 2019

Kurzfassung

Gemäß Eurocode 1 [1] ist in Deutschland für die Unterbauten von Brücken außerorts in Fahrtrichtung eine horizontale Anpralllast von 1.500 kN zu berücksichtigen. Gemäß ZTV‐ING [2] ist dagegen für die Stiele von Verkehrszeichenbrücken eine Anpralllast von 100 kN anzusetzen. Im Rahmen eines Forschungsvorhabens [3] wurde aufbauend auf einer qualitativen und quantitativen Risikoanalyse sowie der Berechnung der Auftretenswahrscheinlichkeit eine statische Ersatzkraft für ein Anprallereignis an eine Verkehrszeichenbrücke anhand dynamischer numerischer FE‐Berechnungen berechnet. Die Auftretenswahrscheinlichkeit für den Anprall an eine Verkehrszeichenbrücke P (Anprall mit Todesfolge/km) konnte auf der Grundlage recherchierter Anprallereignisse mit 6,8  ×  10–5/Jahr berechnet werden. Am Gesamtmodell einer Verkehrszeichenbrücke wurden dynamische Berechnungen mit dem Programm Siemens NX [4] durchgeführt. Der Anprallkörper wurde dabei so modelliert, dass der Lkw‐Anprall möglichst realistisch nachempfunden werden kann. Es zeigte sich, dass ein Anprallsockel gemäß Richtzeichnung RiZ‐ING VZB 4 [5] eine deutliche Reduzierung des Anprallereignisses im Hinblick auf Geschwindigkeit und einwirkende Masse an die Stütze bewirkt. Die statischen und dynamischen Berechnungen haben zudem gezeigt, dass durch die Berücksichtigung der dynamischen Effekte eine Steigerung der Tragfähigkeit von ca. 90 % durch die Trägheit der Verkehrszeichenbrücke und ca. 50 % durch die Dehnrateneffekte zu erwarten ist.
Risikomanagement im Tunnelbau ‐ Steuerung von Kosten und Terminen mit einem baubetrieblichen Referenzmodell über den gesamten Lebenszyklus
Authors: Schwarz Jürgen
Published: April 2019

Kurzfassung

Insbesondere bei Großprojekten wird von der Politik in sehr frühen Planungsphasen – schon bei Entstehen einer Projektidee – eine Prognose für Kosten und Zeit verlangt. Unsystematische, unwissenschaftliche grobe Schätzungen sind ungenau und oft viel zu niedrig angesetzt. „Der Fluch der ersten Zahl“ belastet ein Projekt schon im Entstehen, wenn die Prognosen mit fortschreitender Planung und noch in der Bauphase immer wieder nach oben korrigiert werden müssen. Dabei gibt es das ingenieurmäßige Handwerkszeug, ein systematisches Risikomanagement für Kosten und Zeit durchzuführen, es wird nur zu oft nicht angewendet . Es gibt aber auch herausragende positive Beispiele wie den Brenner Basistunnel . Im vorliegenden Beitrag wird eine Methodik vorgestellt, beginnend mit einem Referenzmodell, mit der das Risikomanagement für Kosten und Zeit durchgängig durchgeführt werden kann: von Anfang an über alle Lebenszyklusphasen, von der Projektidee über Planung und Ausführung bis hin zum Betrieb. Die Anwendung der Methodik wird für den Tunnelbau beschrieben. Die Einbeziehung moderner Methoden, wie das „Building Information Management (BIM)“ und auch partnerschaftliche Vertragsmodelle , wird integraler Bestandteil.
Bogenbrücken‐Monitoring: Vom Experiment zur Struktur
Authors: Krawtschuk Alexander , Geier Roman , Mack Thomas
Published: April 2019

Kurzfassung

Im konstruktiven Ingenieurbau sind Instandhaltungsstrategien und die damit verbundenen Investitionskosten von der Bauart, der Qualität der Ausführung und der konstruktiven Durchbildung der Bauwerke abhängig. Heutzutage neigen Brückenbesitzer und Planer dazu, sogenannte Lebenszyklus‐Kosten‐Analysen in ihrem Entscheidungsprozess miteinzubeziehen, um die Gesamtkonzeption, die Zuverlässigkeit einer Struktur und die Dauerhaftigkeit im entsprechenden budgetären Rahmen zu optimieren. Geschickte, permanente oder kurzfristige Monitoring‐Konzepte und Messungen können die damit auftretenden bzw. potenziellen Gefahren durch Beobachtung des Verhaltens der Bauteile während festgelegter Fristen reduzieren. In den letzten Jahren wurden große Fortschritte in Konstruktion, Modellierung, Analyse, Überwachung, Wartung und Sanierung von Ingenieurbauwerken erzielt. Die Überwachung kann: (a) die Qualitätskontrolle von Werkstoffen, Bauteilen und Strukturen und (b) die Ermittlung und Beobachtung von Alterungs‐ und Abbauprozessen an Tragwerken durch die gezielte Beobachtung mechanischer, chemischer oder energetischer Kenngrößen umfassen. In diesem Artikel werden verschiedene Monitoring‐Systeme unter realen und Laborbedingungen beschrieben und die Funktionsfähigkeit und Wichtigkeit von Monitoring‐Systemen im Bauablauf dargestellt.
The CasaClima building assessment scheme: A key to design and construction quality, energy efficiency, and sustainability
Authors: Santa Ulrich , Bancher Mariadonata , Demattio Martina , Klammsteiner Ulrich
Published: April 2019

Building assessment schemes are recognized to be a powerful tool to promote a more sustainable built environment. For CasaClima, sustainability in the building sector represents a holistic concept, which not only evaluates the energy efficiency but goes further by considering a broader spectrum of aspects. At the roots of the CasaClima, sustainability seals lays the proven CasaClima energy efficiency certification extended by a set of criteria aimed at reducing the waste of natural resources, thereby limiting the environmental impact and assuring the well‐being of the people who live or work in the buildings. The CasaClima Agency, a public and independent body and a competence and research center for sustainable buildings standards, deals with all aspects related to the sustainability and quality assurance of the entire construction process from the planning, to on‐site audits, and finally the issuing of the CasaClima certification.
Existing RC structures strengthened by ties under seismic sequences considering uncertainty
Authors: Liolios Angelos , Hatzigeorgiou George , Liolios Konstantinos , Spyridis Panagiotis
Published: April 2019

The probabilistic seismic analysis of existing reinforced concrete (RC) structures, which are strengthened by cable elements (tension‐ties), is numerically investigated. Emphasis is given to uncertainties for the estimation of structural input parameters, common to old RC structures, and to accumulative effects of seismic sequences on the structure response. Monte Carlo techniques are used and the unilateral behavior of the cable elements, which can undertake tension stresses only, is strictly taken into account.
Load capacity proof of a rib vault, rebuilt based on a historical model
Authors: Scheerer Silke , Hampel Torsten , Wellner Sabine , Opitz Heinz , Curbach Manfred
Published: April 2019

Dresden's Castle was destroyed in February 1945 to a large extent. Its gradual reconstruction took several decades. The last major building task was the reconstruction of the Schützkapelle (in English: Schütz Chapel). The biggest challenge was the construction of a masonry rib vault according to its historic model. Because of difficulties in accurately determining the mathematical description of the vault, a load test was conducted on a 1:1 model of one bay of the vault. For the load application, 48 tie rods were used. A total of six main load cases were tested. The ultimate load‐bearing capacity and the serviceability of the vault were successfully demonstrated.
Von einzelnen Versuchen zu Robustheits‐ und Redundanzansätzen von Befestigungssystemen
Authors: Spyridis Panagiotis , Mihala Ronald
Published: April 2019

Kurzfassung

Befestigungen im Beton werden sehr oft über eine Gruppe oder ein System von Verbindungselementen realisiert, die mit einer Vorrichtung verbunden sind. Die Tragfähigkeit einzelner Verbindungselemente wird durch eine stark nichtlineare Interaktion mit den anderen Komponenten in der Gruppe gekennzeichnet. Diese Wechselwirkung wird auf zwei Ebenen bei der Bemessung betrachtet, nämlich (a) über die Verteilung der Kräfte auf die einzelnen Anker und (b) durch die gegenseitige Festigkeitsabminderung der einzelnen Befestigungselemente in unmittelbarer Nähe. Folglich können Ansätze hinsichtlich Umverteilung von Kräften und progressiver Versagensvorgänge eine angemessene Bewertung der Struktursicherheit solcher Systeme ermöglichen. Dieser Beitrag schlägt eine Modellbetrachtung für Befestigungssysteme vor, die Robustheitsprinzipien verwendet. Es zeigt experimentelle Ergebnisse und Versagensfälle, die die Notwendigkeit eines solchen Ansatzes belegen, und es stellt eine entsprechende Fallstudie für die Robustheitsbewertung einer Gruppe von Ankern im Beton dar.
Temperature variation rates in concrete at low installation temperatures of bonded fasteners
Authors: Wall Friedrich , Neuerburg Ralf , Bourgund Ulrich
Published: April 2019

Post‐installed bonded fasteners, also known as adhesive anchors, are used for the fastening of structural as well as nonstructural elements in a large variety of applications in concrete structures. The performance of these anchors is affected by the temperature conditions during the installation as well as over the design service life of the fastener. In this contribution, the temperature rates in the concrete, as relevant in the context of the installation of bonded fasteners at low installation temperatures, during winter months are investigated. Temperature sensors were installed in the concrete element at different depths. The concrete elements were stored in outdoor conditions for the period of this investigation. In addition, the temperature of the surrounding air as well as the solar radiation was measured. To investigate the influence of the color of the concrete, concrete elements with dark color as well as light color were used. The investigation shows that the temperature in the concrete at depths related to bonded fasteners may increase during the winter months at a rate of several degree Kelvin per hour. These results provide important information for the assessment of bonded fasteners installed at low installation temperatures.
Numerische Untersuchung über die Steifigkeit von Ankerplatten
Authors: Zhu Feng , Schätzle Joachim , Burkhardt Frank
Published: April 2019

Kurzfassung

Nachträgliche Befestigungen sind eine wirtschaftliche Maßnahme zur Verbindung von Stahlbauteilen mit Beton. Zur sicheren Anwendung dieser Befestigungen bietet die aktuelle Richtlinie FprEN‐1992‐4 [1] aufgrund der Elastizitätstheorie ein Rechenverfahren für die Lastverteilung bei Gruppenbefestigungen an. Allerdings basiert diese Bemessungsmethode auf der Annahme einer ausreichend steifen Ankerplatte. Die Steifigkeit der Ankerplatte hat Einfluss auf die sichere Anwendung der Befestigungselemente. Bisher gibt es noch kein zufriedenstellendes Kriterium für den Nachweis der Steifigkeit der Ankerplatten. In diesem Beitrag wird ein aktuelles Rechenverfahren zur Ermittlung der Gesamttragfähigkeit einer 6er‐Gruppenbefestigung mithilfe von stochastischen FE‐Simulationen untersucht und ein praktisches, vereinfachtes Geometriekriterium für den Geltungsbereich des aktuellen Rechenverfahrens vorgeschlagen.
Safety analysis and reliability assessment of engineering structures – The success story of SARA
Authors: Strauss Alfred , Novák Drahomír , Lehký David , Vořechovský Miroslav , Teplý Břetislav , Pukl Radomír , Červenka Vladimír , Eichinger‐Vill Eva M. , Santa Ulrich
Published: April 2019

The concept for the safety assessment of concrete structures integrating nonlinear finite element analysis with stochastic and reliability technology into an advanced engineering tool is presented. The basic aim of the stochastic nonlinear analysis is to calculate the safety index (and failure probability) of an existing engineering structure, which characterizes its reliability. The nonlinear solution enables a realistic estimation of the structural response statistics to be obtained (failure load, deflections, cracks, stresses, etc.). The development of possibility of randomization for such computationally intensive problems was part of the project Safety Analysis and Reliability Assessment of Engineering Structures (SARA). Latin hypercube sampling has been used in SARA in order to keep the number of required simulations at an acceptable level. Statistical correlation, which is important for a realistic solution, was also imposed in SARA by using a stochastic optimization technique called simulated annealing. The sensitivity of results to random input parameters can be evaluated using nonparametric rank‐order correlation coefficients. The presented project SARA focusing on the safety assessment of engineering structures supersedes the usual methods based on simplified formulas. SARA supports a higher level of decision‐making process in bridge administration and maintenance of transport macrostructure. The object of this article is to present the diverse developments of the project SARA and to honor Professor Konrad Bergmeister, who was the frontrunner and chair of SARA and was mainly responsible for the SARA project initiation and its fruitful and amazing developments.
Voraussetzungen für den praktischen Einsatz von Ultra High Performance Fibre Reinforced Composite (UHPFRC)
Authors: Sparowitz Lutz
Published: April 2019

Kurzfassung

Der vorliegende Beitrag gibt vorweg einen zusammenfassenden Überblick über die Materialeigenschaften und Anwendungsmöglichkeiten von Ultra High Performance Fibre Reinforced Composite (UHPFRC, kurz UHPC). Besonders hervorzuheben ist seine bislang unerreichte Dauerhaftigkeit. Sie macht dieses faszinierende Material nachhaltig und wirtschaftlich. Obwohl UHPC bereits einige Jahrzehnte bekannt ist, wird er bis heute in der Praxis nur zögerlich angewendet. In den meisten Ländern fehlen nämlich entsprechende Normen oder Richtlinien, und die Planer verfügen nicht über das entsprechende konstruktive Know‐how. Den ausführenden Firmen mangelt es an Erfahrung hinsichtlich der Kalkulation und der Bauausführung, und es fehlt auch die richtige Geräteausstattung. Deshalb ist es derzeit nicht möglich, UHPC in kleineren Mengen mit dem üblichen Personal auf der Baustelle als Ortbeton herzustellen. Auch wenn der Bauherr von den Vorteilen dieses zukunftweisenden Materials überzeugt ist, benötigt er für eine korrekte Auftragsvergabe mehrere vergleichbare Angebote. Die Bauindustrie stellt aber derzeit keine UHPC‐Angebote bereit. Um dieser Problematik zu begegnen, wird eine innovative mobile Mischanlage mit einer neuen materialspezifischen Mischtechnik vorgestellt, die den Baufirmen einen einfachen und risikoarmen Zugang zur UHPC‐Technologie eröffnet. Und es wird beispielhaft auf UHPC‐Bauverfahren eingegangen, die eine schnelle und wirtschaftliche Bauausführung ermöglichen.
Janus Gold Nanostars–Mesoporous Silica Nanoparticles for NIR‐Light‐Triggered Drug Delivery
Authors: Hernández Montoto Andy , Llopis‐Lorente Antoni , Gorbe Mónica , M. Terrés José , Cao‐Milán Roberto , Díaz de Greñu Borja , Alfonso María , Ibañez Javier , Marcos María D. , Orzáez Mar , Villalonga Reynaldo , Martínez‐Máñez Ramón , Sancenón Félix
Published: April 2019

Janus gold nanostar–mesoporous silica nanoparticle (AuNSt–MSNP) nanodevices able to release an entrapped payload upon irradiation with near infrared (NIR) light were prepared and characterized. The AuNSt surface was functionalized with a thiolated photolabile molecule (5), whereas the mesoporous silica face was loaded with a model drug (doxorubicin) and capped with proton‐responsive benzimidazole‐β‐cyclodextrin supramolecular gatekeepers (N 1). Upon irradiation with NIR‐light, the photolabile compound 5 photodissociated, resulting in the formation of succinic acid, which induced the opening of the gatekeeper and cargo delivery. In the overall mechanism, the gold surface acts as a photochemical transducer capable of transforming the NIR‐light input into a chemical messenger (succinic acid) that opens the supramolecular nanovalve. The prepared hybrid nanoparticles were non‐cytotoxic to HeLa cells, until they were irradiated with a NIR laser, which led to intracellular doxorubicin release and hyperthermia. This induced a remarkable reduction in HeLa cells viability.
We cannot ignore the real component of the rise in thyroid cancer incidence
Authors: Goldenberg David
Published: April 2019

Although overdiagnosis certainly occurs, this does not absolve clinicians of the duty to seek the cause of the real rise in thyroid cancer. In this light, factors that may be causing a true increase in thyroid cancer must be examined closely, and which thyroid cancers will behave in an indolent fashion versus an aggressive fashion must be differentiated.
Incidence and outcome after first molecular versus overt recurrence in patients with Philadelphia chromosome–positive acute lymphoblastic leukemia included in the ALL Ph08 trial from the Spanish PETHEMA Group
Authors: Ribera Josep‐Maria , García Olga , Moreno María‐José , Barba Pere , García‐Cadenas Irene , Mercadal Santiago , Montesinos Pau , Barrios Manuel , González‐Campos José , Martínez‐Carballeira Daniel , Gil Cristina , Ribera Jordi , Vives Susana , Novo Andrés , Cervera Marta , Serrano Josefina , Lavilla Esperanza , Abella Eugenia , Tormo Mar , Amigo María‐Luz , Artola María‐Teresa , Genescà Eulalia , Bravo Pilar , García‐Belmonte Daniel , García‐Guiñón Antoni , Hernández‐Rivas Jesús‐María , Feliu Evarist ,   on behalf of the PETHEMA Group of the Spanish Society of Hematology
Published: April 2019

Background

Disease recurrence occurs in 20% to 40% of adults with Philadelphia chromosome–positive acute lymphoblastic leukemia (Ph+ ALL) who are treated with chemotherapy and tyrosine kinase inhibitors (TKIs). In the current study, the authors report the incidence, treatment, and outcome after first disease recurrence in young and older adults treated in the ALL Ph08 trial (ClinicalTrials.gov identifier NCT01491763).

Methods

Patients aged 18 to 55 years with de novo Ph+ ALL were treated with imatinib concurrently with standard‐dose induction and consolidation therapy followed by allogeneic hematopoietic stem cell transplantation (allo‐HSCT) when possible. In patients with first disease recurrence, the authors analyzed the type of recurrence, timing, location, presence of kinase domain mutations, type of treatment, and outcomes.

Results

Of the 125 patients, 28 patients (22%) developed disease recurrence before (4 patients) or after (24 patients) HSCT, with the recurrences being molecular in 11 patients (39%) and overt in 17 patients (61%). T315I was the most common mutation noted at the time of disease recurrence. Change in TKI was the most frequent treatment for patients with molecular disease recurrence whereas rescue chemotherapy and TKI change followed by second allo‐HSCT when possible were performed for the most part in patients with overt disease recurrence. A total of 20 patients (71%) achieved response. The median disease‐free survival (DFS) and overall survival (OS) were 8.5 months and 15.3 months, respectively. A trend for better DFS and OS was observed in patients with molecular recurrence compared with those with overt recurrence (median of 16.9 months vs 6.3 months [P = .05] and 28.7 months vs 11.5 months [P = .05] for DFS and OS, respectively).

Conclusions

Disease recurrence was frequent in young and older adults with Ph+ ALL who were treated with imatinib and chemotherapy with HSCT. Although the majority of patients responded to rescue therapy, their outcomes were poor, especially with regard to overt disease recurrence.
The American Joint Committee on Cancer turns 60
Authors: Greene Frederick L. , Byrd David R. , Brookland Robert K. , Amin Mahul B. , Gress Donna M.
Published: April 2019

The American Joint Committee on Cancer was founded in 1959. Over the last 60 years, the organization has been dedicated to expanding and promoting the TNM cancer staging system.
“Tell it as it is”: How Sisom prompts children and parents to discuss their cancer experience
Authors: Tsimicalis Argerie , Rennick Janet , Le May Sylvie , Stinson Jennifer , Sarkis Bianca , Séguin Karine , Siedlikowski Maia , Choquette Anne , Louli Julie
Published: April 2019

Background

Sisom is an interactive computerized tool shown to improve communication between children with cancer and their clinicians in Norway. Concerns that Sisom may prompt disclosure of potentially distressful symptoms during a busy clinical day may deter implementation in practice in other settings.

Aim

The purpose of this study was to describe the questions, concerns, and comments that unfolded between children and their parents during the children's use of Sisom within a research context.

Methods

A secondary analysis of qualitative interview transcripts derived from the interactions of 39 children with cancer aged 6 to 13 years with Sisom from two previous studies was performed. Thirty‐one of these interactions had at least one parent present during testing. Data were coded and analyzed using content analysis techniques involving an iterative process of data reduction, display, conclusion drawing, and verification.

Results

Sisom elicited a verbal response to at least one symptom in the majority of children (n = 33, 85%) and prompted at least one input in 23 of the parents (74%). Sisom prompted children to (1) discuss their thoughts and feelings out loud, (2) categorize their symptoms as pleasant or unpleasant, and (3) reflect on their illness experiences with varying degrees of certainty. Parental input consisted of (1) providing clarification, (2) validating their child's responses, (3) guiding their child's responses, (4) responding on behalf of their child, and (5) making jokes or casual remarks.

Conclusion

Sisom prompts children to discuss their thoughts and illness experiences with their parents and to express their emotions. Sisom may be a useful tool to enhance the communication between children with cancer and their parents and clinicians, which may help them express their needs in the health care setting.
Cost‐efficient disaster backup for multiple data centers using capacity‐constrained multicast
Authors: Li Xiaole , Wang Hua , Yi Shanwen , Zhai Linbo
Published: April 2019

To leverage periodic disaster backup in a cloud data center (DC) network, previous studies employ disjoint unicast paths for bulk data transfers among multiple geographically distributed DCs, causing massive unnecessary traffic duplication. This not only adds the overhead but also may result in severe network congestion. With flexible network resource management in software‐defined networks and powerful traffic aggregation capability of multicast, we propose capacity‐constrained multicast to realize cost‐efficient disaster backup. First, considering limited backup storage capacity and essential redundancy guarantee, we construct a capacity‐constrained multicasting backup model. Then, we formulate the disaster backup problem as capacity‐constrained multiple Steiner tree problem, which is NP‐hard. To solve this problem, we design a new multicasting backup ant colony optimization algorithm based on requirement‐aware growth. It directly optimizes every disaster‐backup multicast tree (DBMT) from its root node to cover enough destination nodes guaranteeing sufficient redundancy and then expands them into the forest under the guidance of a multicast tree shared degree, the ratio of available storage capacity, and backup load distribution offset. We introduce unique edge fitness evaluation and pheromones for every DBMT to reduce mutual influences among multiple trees. Extensive simulations demonstrate that our strategy performs with less bandwidth consumption cost and relatively good backup load distribution fairness simultaneously.