bluuebunny/crossref_metadata_2025 huggingface dataset:
Suggestions for improved reinforced concrete half-joint bridge inspection in England
Authors: Desnerck Pieter , Valerio Pierfrancesco , Lees Janet M , Loudon Neil
Published: October 2018

Asset management databases play a crucial role in the management of existing infrastructure assets. Highways England (HE) has a long history of using bridge management software to record the current state of bridges and to guide maintenance schemes and interventions. Reinforced concrete half-joints are amongst the most challenging structures to inspect and repair due to their susceptibility to deterioration and construction type. Hence, they require particular attention within asset management programmes. An Interim Management Strategy was developed by HE to identify all the structures on the Highways England road network with half-joint elements. These half-joint structures were then subjected to a special inspection regime. Out of the 428 half-joint structures with inspection data, 252 structures had defects associated with four existing HE defect classes. A review of the inspection database with a focus on half-joints led to an alternative classification of half-joint related defects based on a revised set of Defect Classes, the introduction of Defect Groups and the extraction of Defect Types specifically observed in half-joints. Using this new classification, the most common half-joint Defect Groups were found to be cracking, corrosion, spalling and deterioration mechanisms. In about half of the structures cracking and corrosion tended to be observed together. Correlations were also shown to exist between structural and deterioration, and constructional Defect Classes, emphasising the need for quality control and proper workmanship. Recommendations to address shortcomings in current inspection practice are proposed. Clearer defect definitions and decision-tree guidance for inspectors could enhance the consistency and repeatability of inspection data gathering thereby overcoming some of the limitations of subjective classifications. Acquiring additional information about the observed crack details including zonal information, crack patterns, crack extent, crack orientations and widths combined with local and global pictorial evidence would also be advantageous. This could then provide the basis for the automatic processing and identification of structures with specific half-joint related defects. In this way, asset managers would be better able to allocate limited resources to the most critical structures.
Detection of near-surface reinforcement in concrete components with ultrasound
Authors: Vonk Sarah , Taffe Alexander
Published: October 2018

Ultrasonic testing of concrete has grown in importance considerably in recent years in non-destructive testing in civil engineering (NDT-CE). In the past, the main focus was on the imaging of the internal construction of steel and prestressed concrete components. On the other hand, comparatively little attention was paid to the location of near-surface reinforcement and concrete cover measurement. In this research, it is shown to what extent ultrasound is suitable for the detection of near-surface reinforcement in addition to magnetic inductive methods. The measurements were carried out with the newly developed Pundit 250 Array from the company Proceq and with the measuring devices of the company Acsys, the A1220 Monolith and the A1040 Mira. The ultrasound data was analysed with the vendor-independent software InterSAFT of the University of Kassel. Systematic investigations were carried out on test specimens with a variety on the concrete cover, the diameter of the reinforcement and the reinforcement ratio in the form of mesh reinforcement close to the surface. The detectability and accuracy of the concrete cover were set in relation to the concrete cover, wavelength and reinforcement diameter, with the result that more detailed rules for the detection of reinforcement are formulated for the user, instead of the known λ/2-criterion.
Assessment of the in situ compressive and tensile strength of existing massive hydraulic structures
Authors: Spörel Frank
Published: October 2018

In Germany hydraulic structures like weirs or locks under the responsibility of the Federal Min-istry of Transport and Digital Infrastructure have an average age of about 80 years. They often show static characteristics, such as construction methods or very large cross sections that are no longer common practice today. When retrofittings are planned new calculations to verify its conformity with stability requirements become necessary. As no adapted regulations have been released for re-assessing the statics of existing solid hydraulic structures a Code of practice has been developed. Compressive and tensile strength derived from concrete cores are decisive input parameters for the calculations. During the last decades concrete cores of more than hundred existing hydraulic structures have been examined by the Federal Waterways Engineering and Research Institute (BAW). These investigations were analysed comprehensively concerning the variation of strength properties and the correlation between compressive and tensile strength in massive hydraulic structures. Furthermore given correlations and factors in technical guidelines which were usually derived by investigations on lab specimen at an age of 28 days were verified concerning their applicability on in situ concrete of old, massive structures. The findings are presented in the paper.
Design Considerations and Innovative Approach for Restoration of Historic Landmarks in Old Montreal
Authors: Morin Richard , Al Chami Ghfran , Gagné Richard , Bissonnette Benoit
Published: October 2018

Restoration of some streets in Old Montreal is achieved using granite pavers bonded with a mortar bed to a concrete slab. The technique was originally used for the pavement of St-Paul Street with stone bricks back in the 1800's. A similar approach is being used in 2016 to renovate the very same street, except for the materials used in casting the foundation slab. In order to space out the expansion joints and prevent drying shrinkage cracking, fibre reinforcement and an expansive component are incorporated in the concrete. The concept was successfully used in bridge deck rehabilitation projects such as Girouard Overpass deck overlay. The basic principle of this approach is to generate a chemical expansion in the concrete (200 to 300 gm/m) using an expansive component, and to restrain the generated expansion through the combined action of ordinary peripheral steel reinforcement in the slab and steel fibre reinforcement in the concrete. The objective is to mitigate shrinkage stresses by keeping the strain balance as low as possible and allowing the concrete additional time to develop sufficient tensile strength, such that the stresses induced in the concrete slabs will remain lower than the concrete tensile strength.Restraint of expansion by the steel fibres and the peripheral reinforcement induces an initial compressive stress in the concrete slab. A part of this stress is used to compensate for the drying shrinkage, whereas the remaining part (if any) is used to resist incidental restrained deformation (e.g. thermal strains) cracking. Concrete mixture proportioning, placement, and curing need to be optimized in order to achieve enough expansion to adequately control cracking due to restrained shrinkage. After proper moist curing of the slab, the pavers are bonded to its top surface using a latex-modified mortar (latex to cement ratio of about 11% by mass). The latex-modified mortar used as a levelling bed underneath the pavers has a low vapour permeability that partially seals the concrete surface and further contributes to minimize drying shrinkage cracking. Since 2011, various historic landmarks in the City of Montreal have been restored using concrete containing an expansive component. To this date, monitoring and performance reports have showed that the chemical prestress approach is quite effective in decreasing shrinkage cracking in paved street foundations, thereby allowing the placement of longer slabs with significantly fewer expansion joints.
Rehabilitation of Marine Concrete Structure with Under-Water Hydrodemolition and Sprayed Concrete
Authors: YUN Kyong-Ku , Lee Kyeo-Re , HAN Seung-Yeon , KIM Yong-Gon , KWON Soo-Ahn
Published: October 2018

Hydrodemolition is a method of surface preparation using high-pressure water jets. Hydrodemolition cutting depth is dependent on the length of time that the water jet is directed at the concrete surface that determines the depth of removal, and contact time is controlled at the robotic cutter. During hydrodemolition concrete removal, the cement matrix is removed from the aggregate. This paper describe on the test results of under-water hydrodemolition which was done on a prefabricated concrete basin. A very simple and economic method for repairing the damaged concrete structures is a using a sprayed concrete, which is some times called as shotcrete. This paper, also, describe on the test results of sprayed concrete for the rehabilitation of marine concrete structure.
Non-destructive testing of concrete treated with penetrating surface sealant using a Karsten-tube
Authors: Nwaubani Sunday O.
Published: October 2018

Surface treatment is increasingly becoming acceptable as a means of ensuring concrete durability by way of controlling or preventing the ingress of various deleterious agents of concrete deterioration. In practice, a combination of non-destructive and semi-destructive evaluation of the concrete surface is often necessary to decide on the need for treatment or re-treatment of previously treated surfaces. The owners of structures and restorers appreciate simple and non-destructive methods in making any interventions on surfaces that have been treated previously. Existing knowledge would suggest that correct interpretation of these test results would depend on an understanding of the effect of factors such as the initial moisture content, quality of the concrete and exposure conditions. This paper presents the result of a study to assess the applicability of the “Karsten-tube” in measuring the water uptake of treated and un-treated concrete surfaces and the effects of the concrete quality, and environmental conditions upon the test results. The results are compared with complementary tests for oxygen permeability and porosity of the concrete specimens studied. Three concrete mixes and five different exposure conditions were investigated. Some specimens were soaked in 3% Sodium Chloride solution to study the effects of aggressive agents. The results indicates that Karsten-tube is a quick non-destructive method for obtaining useful information about the condition of treated and un-treated concrete surfaces and could be used for rapid and reliable assessment of the need for re-treatment of previously treated surfaces. Well-treated surfaces will have low water uptake values, irrespective of the quality of the concrete.
Investigation in Remediation of Wind Turbine Generator (WTG) Foundations with Epoxy Resin
Authors: Bode Kay A.
Published: October 2018

This article shows the principle requirements for remediation of WTG foundations and the advantages and disadvantages of different injection materials like cement lime, epoxy resin and PUR resin. Mostly there are reservations against epoxy resin mainly because of assuming wet cracks in foundations. Regarding state of the art epoxy resins are not usable at wet surfaces or for cracks with liquid water inside. It will be shown that nevertheless it can work and why it works. There were done some basic investigations in how to fill a crack/gap between two concrete slabs. The gap was filled with water or a suspension to simulate a wet crack surface. The spread of an Epoxy resin in the gap was investigated.
The effect of hydrophobic (silane) treatment on concrete durability characteristics
Authors: Sohawon Haris , Beushausen Hans
Published: October 2018

Hydrophobic (silane) impregnation represents a cost-effective way to increase the durability of concrete structures in cases where insufficient design cover quality and depth have been achieved. The water repellent product lines the internal capillary pore structure and provides a water-repellent concrete surface. Thus, the risk of reinforcement corrosion initiation and subsequent deterioration can be reduced as the ingress of water-dissolved aggressive species (chlorides) is minimised or prevented. The purpose of this study was to investigate the effect of silane impregnation on durability indicators, including penetrability tests and chloride ingress (bulk diffusion). The results indicate that silane impregnation reduces capillary absorption and conductivity of chloride ions. Similarly, chloride ingress in the treated concrete mixes was suppressed.
Development of safe construction temperature ranges to avoid blow-ups in Ultra-Thin Concrete Pavements
Authors: Mentz Johannes , Hartman Anton
Published: October 2018

After the construction of an ultra-thin concrete pavement, ambient temperatures may induce an axial force within the pavement due to thermal expansion that can lead to the formation of a blow-up failure. By analysing the mechanism of a blow-up, temperature differentiates at which a blow-up failure in ultra-thin concrete pavements may occur were identified. Safe construction temperature range graphs were produced for different ultra-thin concrete pavements to serve as a guideline that would potentially limit the occurrence of blow-ups.
A study on the bond behavior of different FRCM systems
Authors: Younis Adel , Ebead Usama
Published: October 2018

Fabric-reinforced cementitous matrix (FRCM) composites are usually applied on the concrete surface for the purpose of strengthening reinforced concrete structures. However, the efficiency of FRCM strengthening is notably affected by the bond between the FRCM system and concrete substrate. In view of that, the current paper presents the results of a preliminary experimental study carried out to investigate the bond characteristics between FRCM composites and concrete. Six number of specimens, each consisted of a 150-mm concrete cube with a double-shear connection to an FRCM system, were subjected to direct-shear loading test. The parameters investigated include (a) FRCM material (carbon, polyparaphenylene benzobisoxazole (PBO), and glass); and (b) Bond length (75 mm or 100 mm). The FRCM systems typically included a single layer of fabric with the associated mortar, and the bond width was uniformly taken as 100 mm. The test results revealed that the bond capacity is enhanced with an increase in the FRCM bonded length. The PBO-FRCM showed the highest bond capacity between FRCM composite and concrete substrate among the three systems. The modes of failure observed in carbon-, PBO-, and glass-FRCM bond tests are fabric delamination, FRCM mortar/concrete debonding, and fabric rapture, respectively. The PBOand glass-FRCM bond tests thus exhibited a more brittle behavior at failure than that of the carbon-FRCM counterpart.
Performance of Strain hardening cementitious composite as strengthening and protective overlay in flexural members
Authors: Umer Sial Sardar , Iqbal Khan M.
Published: October 2018

Strain-hardening cementitious composites (SHCC) are advanced type of cement-based composite materials having superior crack control and tensile properties. Owing to such characteristics, SHCC can be used for strengthening and crack-width control of structural members. This paper presents a study on the flexural response of reinforced concrete (RC) beams with different overlays of SHCC. The work consists of RC-SHCC overlay beams, in which SHCC overlays of different thicknesses (15% and 30% of beam height, plus cover) and reinforcement ratios (0% and 0.4%) were cast at the bottom of the RC beams. The performance of the RC-SHCC overlay beams was compared with control RC beams having concrete overlays of similar parameters. A series of eight laboratory-scale control and composite beam specimens were tested under four-point bending test. From the experimental results, it was observed that RC-SHCC overlay beams showed improved flexural capacity and crack control as compared to that of control beams. The beams with unreinforced SHCC overlays showed significant improvement at service stage, while beams with reinforced SHCC overlays showed significant improvement at peak stage. The SHCC overlay beams without reinforcement have showed improved ductility as compared to control beams with concrete overlays. Additionally, the SHCC overlays performed as a protective layer for controlling the crack widths in the composite beams.
Rehabilitation of a Vehicle Impact Damaged Concrete Bridge Girder with GFRP Rebars
Authors: Yazdani Nur , Montero Maria
Published: October 2018

Overpass bridge girders are susceptible to impact damage of over-height vehicles, creating a traffic hazard and structural deficiency. The repair for a damaged girder has to meet adequate criteria for the safety, repair time and economy. This paper presents a case study for the repair of such an impact damaged concrete girder on the Lyndon B. Johnson Express construction project, located on I-635 and I-35 freeways in Dallas, Texas. The impact caused concrete loss and exposed several restressing strands on the exterior girder. The overpass had been completed while the old route was open below, causing a temporary vertical lower clearance than the final design, leading to the impact. The novel and innovative repair process involved fiber glass (GFRP) rebars, bonding epoxy and repair mortar. These rebars enhanced the flexural capacity of the repaired section and supplemented the mortar strength. Onsite load testing was employed to verify the performance of the repaired structure. Theoretical model of the composite girder before and after repair was employed. The strain data from the model compared well with the load testing data. The repair scheme drastically increased the stiffness of the damaged girder, resulting in about 50% reduction in the bottom strains. The beneficial effect of the repair resulted in large increases in the net compressive stresses (200–300%) at the girder bottom through the increase of the section stiffness and reduction of the gravity load stresses. Stresses remained well below the elastic range for concrete and the GFRP rebars.
Concrete columns confined with different composite materials
Authors: Donnini Jacopo , Corinaldesi Valeria
Published: October 2018

In the last decades, the need for upgrading, strengthening and retrofitting of existing concrete structures is rapidly growing. Composite materials showed to be an optimal solution to face this problem, combining high efficacy with low invasiveness. The use of Fiber Reinforced Polymers (FRP) to wrap concrete columns has been widely investigated and became a very successful method to improve their structural performances. However, it has been recognized that FRPs, due to the presence of an organic resin, have a few drawbacks, such as poor mechanical behavior at high temperatures, lack of vapor permeability and impossibility to be installed on wet surfaces. This experimental work aims to propose a comparison between three different innovative methods as possible strengthening solutions for existing concrete columns. The structural behavior of 20 reduced scale concrete columns, realized by using a low performance concrete, in order to reproduce the poor mechanical properties of existing structures, was investigated. Two unreinforced column were tested in compression as reference. Six of them where reinforced by applying an external layer of FRP, with different types of fabric reinforcement (made of carbon or PBO fibers). Six columns were reinforced by using the same fabrics coupled with an inorganic matrix (FRCM) instead of epoxy. Six other columns were reinforced by using a layer of High Performance Fiber Reinforced Concrete (HPFRC) of 3 cm thick. Experimental results have been analyzed and performance of the three reinforcement systems have been compared.
Acoustic monitoring of a prestressed concrete beam reinforced by adhesively bonded composite
Authors: Chataigner Sylvain , Gaillet Laurent , Falaise Yannick , David Jean-François , Michel Richard , Aubagnac Christophe , Houel Adrien , Germain Didier , Maherault Jean-Philippe
Published: October 2018

The use of adhesively bonded composite reinforcement is relatively widely used for concrete structures. Yet, some questions remain regarding its use in the case of prestressed concrete structures especially in relation with the influence of existing cracking and the verification of the encountered damage phenomena at real scale. French National Organism CEREMA with the help of French motorway bridge owners association ASFA and French National Research Organism IFSTTAR realized several real size experimental investigations of an old prestressed concrete beam coming from a deconstructed bridge to answer these questions (Project CLERVAL). Both flexure and shear tests up to failure were carried out and several measurement methods were used to understand the role of the composite reinforcement on the behavior of the structure and the damage scenario. Acoustic emission was one of these methods and two different systems were investigated. The proposed communication will first describe the two used acoustic systems and their dedication (localized acoustic emission and overall acoustic survey). A specific development will then be presented aiming at optimizing the obtained acoustic phenomena localization taking into account the anisotropy of the prestressed concrete beam. Finally, main results will then be presented for both flexure and shear tests.
Strengthening of a railway arch bridge from 1854
Authors: Andersen Ole Viggo
Published: October 2018

This paper presents the inspection of the condition and the design for strengthening of an existing railway arch bridge constructed in 1854. The original arch bridge is constructed with 5 layers of bricks in the arch and granite blocks in the foundation on top of an arrangement of frame made of timber and carried by piles. From the inspection it was concluded that the bricks in the arch was damaged due to freeze-thaw. It was also concluded that the timber structure in the foundation was rotten. The bridge is crossing a small creek. The environment is very sensitive. The access to the construction site is passing through landscape subject to preservation. The strengthening project included the arrangement of a new reinforced concrete arch. The arch was anchored with glued reinforcement bonded to the existing brick arch. The reinforcement and formwork was placed above the creek without disturbing the fauna in the water. The concrete was pumped into a form under the existing arch. After curing of the concrete arch, the strengthening of the foundation was initiated. It was planned to construct a bottom slab under the creek, which was able to carry the new concrete arch. In order to get access for the construction work the creek water was pumped through pipes suspended under the top of the new concrete arch. The procedures to handle the very delicate situation of replacing the foundation, while the bridge was in operation, and also protecting the environment is described in detail in the presentation. The process included high speed concrete curing, working processes under extreme narrow conditions and a very tight schedule.
Structural Repair to Conserve Langkawi’s Main Tourist Attraction: Practical Approach
Authors: Mohammad Maziah , Zahari Ros Asmah
Published: October 2018

Direct exposure to marine environment causes accelerated corrosion process of all reinforced concrete structures, consequently, causes cracks, deterioration and overall reduction in the sstructural integrity. The aim of this paper is to study the deterioration and technique of repair work at Eagle Square as a landmark of Langkawi Island. Most of the structural problems which occurred at the splash zone were spalling and delamination on beam, slab and pile cap. Material testing was carried out at selected locations to ob tain detailed information relating to the extent and causes of deterioration of the structure. The result showed that the carbonation depth was smaller than concrete cover and the amount of chloride ions was 0.23% by mass of cement and 50% of the splash zone was having 90% probability of corrosion. After obtaining the necessary data, the study directed towards deciding the remedial work. The Eagle Square structure members were successfully repaired in eight (8) months with proper works planning and repair technique appropriate to the damages.
A new testing method for textile reinforced concrete under impact load
Authors: Hering Marcus , Curbach Manfred
Published: October 2018

Textile reinforced concrete, especially textile reinforced concrete with carbon fibres, was already been used for strengthening steel reinforced concrete structures under static loads up to now. The question is if the composite can also be used for strengthening structures against impact loads. The main goal of a current research project at the Technische Universität Dresden is the development and characterization of a reinforcement fabric with optimized impact resistance. But there is a challenge. There is the need to find the best combination of fibre material (glass, carbon, steel, basalt, …) and reinforcement structure (short fibres, 2D-fabrics, 3D-fabrics, …), but testing the large number of possible combinations is not possible with the established methods. In general, large-scale tests are necessary which are very expensive and time consuming. Therefore, a new testing method has been developed to deal with this large number of possible combinations of material and structural experiments. The following paper describes this new testing method to find the best fabric reinforcement for strengthening reinforced concrete structures against impact loads. The testing devise, which is located in the drop tower facility at the Otto Mohr Laboratory, and the test set-up are illustrated and described. The measurement equipment and the methods to evaluate the experimental results are explained in detail.
Properties of Western Cape Concretes with Metakaolin
Authors: Bakera Alice T. , Alexander Mark G.
Published: October 2018

A global demand for affordable, sustainable, and durable concrete has resulted in growing use of Supplementary Cementitious Materials (SCMs). In the Western Cape Province of South Africa, the readily available SCM is Granulated Ground Corex Slag (GGCS), although fly ash can also be obtained. However, the availability of these SCMs, particularly GGCS, is subject to market and other extraneous factors, and this may render them vulnerable as sources of SCM for concrete. This points to the need for innovation and investigating other potential SCMs which are economically and environmentally effective. Metakaolin, a high-grade type of calcined clay, emerges as a possible potential future SCM in the Western Cape. This study aimed at investigating the influence of a locally available metakaolin on mechanical (compressive and tensile strength), and durability (concrete penetrability and potential to mitigate Alkali Silica Reaction (ASR)) properties of Western Cape concrete. In comparison to GGCS, concretes with metakaolin showed superior performance in both mechanical and durability properties. This was attributed to its role in concrete in terms of accelerating hydration reactions, pozzolanic activity, and dilution effect. Metakaolin can therefore be regarded as a beneficial substitute for GGCS in Western Cape concrete. However, questions that remain include cost-effectiveness, and the awareness and willingness of industry to incorporate this material.
Electrical Resistance Tomography for Assessing Water Movement in Cracked Cementitious Mixtures
Authors: Kawaai Keiyu , Ujike Isao
Published: October 2018

Electrical resistance tomography (ERT) has been studied for visualizing variations of conductivity in concrete specimens. In recent years, unsaturated water flow through pores formed in concrete has been intensively examined though ERT systems to visualize the permeation front that gradually changes with elapsed time. This study examines water movement through internal cracks which are typically not observed on the surface of mortar or concrete specimens via ERT systems. The results indicate the gradual increase of saturated region owing to the ingress of water through cracked surface up to 120 hours. And, the region with higher conductivity estimated in uncracked parts is evidently in good agreement with higher moisture content measured by moisture meter on the split surface. In addition, the presence of crack in concrete specimen subjected to water ingress is clearly visualized via ERT images owing to rapid water movement in cracked zones. This study has provided the important insight that the ingress and the movement of water through pores and cracks formed in cementitious mixtures could be assessed via electrical measurements.
Neurodegenerative Erkrankungen
Authors: Ludolph Albert C.
Published: October 2018

Neurodegenerative Erkrankungen werden von vielen als schicksalhafte Konsequenz der veränderten Altersstruktur der Gesellschaft gesehen, die zu dem Preis gehören, den
wir für unsere gestiegene Lebenserwartung zahlen müssen. Wenngleich diese Annahme im Kern nicht zu bestreiten ist, haben jedoch einige Erkenntnisse der letzten
20 Jahre gezeigt, dass sie zumindest modifiziert werden muss.
Einsatz von Technologie in Präventionsprogrammen
Authors: Polok Adrian
Published: October 2018

Der Markt von eHealth-Anwendungen (mHealth) für Diabetes wird in Deutschland im Jahr 2018 voraussichtlich einen Umsatz von 39 Millionen Euro generieren. Schon jetzt nutzen circa 0,5 Millionen Menschen Diabetes-Apps. Eine kürzlich veröffentlichte retrospektive Studie (n = 2774) zeigt eindrucksvoll, wie der Einsatz von Technologie in Präventionsprogrammen zu einer signifikanten Gewichtsabnahme und verbesserten Blutzuckerwerten bei Probanden mit Prädiabetes führte. Die Motivation der Teilnehmer durch die Dokumentation von Echtzeitdaten über Lebensstil, Ernährung und Aktivitätslevel steigt.
Begleitung von Frauen mit Mehrlingsschwangerschaften
Authors: Peitz Ulrike
Published: October 2018

Mehrlingsschwangerschaften stellen für alle Beteiligten in sehr unterschiedlicher Weise eine besondere Herausforderung dar. Für die Eltern mag es ein Schreckensmoment oder eine besondere Freude sein, wenn sie erfahren, dass sie Zwillinge oder noch mehr Kinder bekommen. Für den Arzt gilt es, im Ultraschall Besonderheiten zu erkennen und zu unterscheiden, ob Handlungsbedarf besteht oder abgewartet werden kann. Für eine Hebamme kann die Herausforderung darin bestehen, einen Weg zwischen schulmedizinischer Begleitung und Alternativen dazu abzuwägen sowie die Frau in ihrer Selbstwahrnehmung zu stärken, sodass sie in der Lage ist, eigenständige und individuelle Entscheidungen zu treffen.
Direkte Kosten sozialer Angststörung bei Jugendlichen und Kosteneffektivität der Psychotherapie
Authors: Dams Judith , Kronmüller Klaus-Thomas , Leibing Eric , Steil Regina , Henningsen Peter , Leichsenring Falk , Peseschkian Hamid , Rosner Rita , Salzer Simone , Stefini Annette , Vonderlin Eva , König Hans-Helmut
Published: October 2018

Hintergrund Ziel war die Analyse direkter Kosten sozialer Angststörung (SAD) bei Jugendlichen und der Kosteneffektivität von CBT bzw. PDT.

Methoden Multizentrische randomisierte Studie mit N = 103 Patienten. Krankheitskosten wurden zur Baseline und Kosteneffektivität nach der Behandlung analysiert.

Ergebnisse Direkte 6-Monats-Kosten zu Baseline lagen bei 809 €. Während die inkrementelle Kosten-Effektivitäts-Relation von CBT im Vergleich zur Warteliste bei 18 824 €/QALY lag, war PDT nicht kosteneffektiv.

Zusammenfassung SAD verursacht hohe direkte Kosten. CBT ist wahrscheinlich kosteneffektiv.
Idiopathisches Parkinson-Syndrom
Authors: Kassubek Jan
Published: October 2018

Das idiopathische Parkinsonsyndrom (IPS) ist klinisch definiert durch ein zentrales Motorsyndrom mit Leitsymptom Hypokinese sowie ein breites Spektrum von
nicht-motorischen Symptomen. Neuropathologisch liegt der Erkrankung eine Propagation des Proteins α-Synuklein im zentralen, peripheren und enterischen
Nervensystem zugrunde, welche im Gehirn in 6 Stadien nach Braak definiert ist. In der Therapie des IPS existieren profunde symptomorientierte Konzepte für die
motorischen Symptome mit Fokus einer dopaminergen Pharmakotherapie. In fortgeschrittenen Erkrankungsphasen mit Auftreten von motorischen Fluktuationen kommen
invasive Therapieverfahren, wie die Tiefe Hirnstimulation, zum Einsatz. Nicht-motorische Symptome sind für den behandelnden Arzt wesentlich innerhalb des
Gesamt-Therapiekonzeptes. Aufbauend auf dem wachsenden Verständnis für diese neurodegenerative Erkrankung sind im Sinne einer kausal orientierten Intervention
zudem innovative Therapien mit Target α-Synuklein auf dem Weg.
Morbus Alzheimer
Authors: Leinert Christoph , Neugebaue Hermann
Published: October 2018

Die Alzheimererkrankung stellt nach wie vor die häufigste neurodegenerative Erkrankung dar. Sie ist gekennzeichnet durch ein langes aysymptomatisches
Prodromalstadium, in dem es nach der bisher gängigen Amyloidhypothese zur Ablagerung fehlgefalteter Proteinaggregate kommt. Die Diagnose erfolgt in erster Linie
klinisch-neuropsychologisch. Zielgerichtete verlaufsmodifizierende Therapieverfahren konnten bisher nicht über eine Phase-III-Studie hinaus ihre Wirksamkeit
belegen, weswegen zuletzt die Amyloidhypothese als Grundlage der Pathophysiologie erneut hinterfragt wird. Darüber hinaus stehen symptomatische medikamentöse
Behandlungen in Form von Acetylcholinesteraseinhibitoren und eines NMDA-Rezeptor-Antagonisten sowie verschiedene nicht-medikamentöse Behandlungsstrategien zur
Verfügung.
Frontotemporale Demenz
Authors: Otto Markus , Feneberg Emily , Anderl-Straub Sarah
Published: October 2018

Die behaviorale frontotemporale Demenz (bvFTD) ist bei Patienten vor dem 65. Lebensjahr die zweithäufigste Demenzerkrankung nach der Alzheimer-Erkrankung. Die
frontotemporalen Atrophien können sich in Form zweier klinischer Subtypen manifestieren. Entweder stehen bei der behavioralen FTD klinisch Verhaltens-, und
Persönlichkeitsveränderungen im Vordergrund oder bei der primär progredienten Aphasie eine Störung von Sprachverständnis und -produktion. Eine sichere Diagnose
kann bisher nur post mortem mit Hilfe der Neuropathologie oder durch den Nachweis einer genetischen Mutation erfolgen. Zur Diagnosestellung werden neben der
klinischen Einteilung derzeit Bildgebungsverfahren (MRT und FDG-PET) zur Beurteilung des Frontal-, und Temporallappens ergänzt. Die Untersuchung von Tau,
Amyloid-ß und der Neurofilamente kann zur Abgrenzung einer Alzheimer-Erkrankung erfolgen.
„Standard Changing News Onkologie“ in der Tumorchirurgie
Authors: Königsrainer Alfred
Published: October 2018

Tumorerkrankungen stellen nach wir vor die zweithäufigste krankheitsbedingte Todesursache in der westlichen Welt dar. Trotz aller Fortschritte in der Diagnostik,
der medikamentösen Tumortherapie aber auch in der chirurgischen Onkologie verlieren wir nach wie vor ca. 50 % der Patienten am Tumorleiden. Schonende Chirurgie
durch minimal invasives Operieren auf der einen Seite erlaubt vielfach eine raschere Rekonvaleszenz bei gleicher onkologischer Qualität, und maximale Chirurgie
bei metastasierten Erkrankungen auf der anderen Seite kann die Prognose auch im Stadium IV deutlich verbessern. Vermehrt kommen auch sogenannte „wait and
see“-Strategien zum Einsatz. In diesem Übersichtsbeitrag werden Konzepte beim Ösophaguskarzinom, beim Magenkarzinom, bei Neuroendokrinen Tumoren (NET) und beim
Pankreaskarzinom beschrieben. Zuletzt noch „Neues“ zur Peritonealkarzinose bei Darmtumoren vom ASCO 2018.
The Prevalence of Anti-Rubella Antibodies in Pregnant Women of Turkey, Results of 94508 Patients in a Tertiary Referral Center
Authors: Sert Umit Yasemin , Ozgu-Erdinc A. Seval , Saygan Sibel , Engin-Ustun Yaprak
Published: October 2018

Aim To determine the seroprevalence of rubella in a tertiary referral center inAnkara,Turkey.

Materials and methods A retrospective, cross-sectional study was performed from 2008 to 2017 at the outpatient clinic of Zekai Tahir Burak Women Health Care, Training and Research Hospital in Ankara, Turkey. The study included 94508 pregnant women and the patients were evaluated in terms of IgG and IgM status, IgG avidity and amniotic fluid PCR testing if needed.

Results Seropositivity for anti-rubella IgG and IgM were 89% and 0.19% respectively. 175 patients with IgM positivity were tested by avidity test, 114 patients were found to have high avidity and 57 patients with low avidity. 4 patients have accepted PCR testing and no positive result was found.

Conclusion In our sample of Turkish population, the rate of rubella IgG seropositivity was high suggesting that routine national vaccination programme for rubella is successful. Screening and vaccination of childbearing aged women and updating the national vaccination policy would be effective for the periodic decreases in the immunity.
Temporal Bone and Cerebellopontine Angle Epidermoid Resulting in Facial Nerve Paralysis: Resection and Facial Nerve Coaptation
Authors: Bien Alexander G. , Kim Christine S. , Kenning Tyler J.
Published: October 2018

Objectives Demonstrate the utilization of a transcochlear approach for resection of an epidermoid involving the temporal bone and cerebellopontine angle (CPA) with end-to-end facial nerve coaptation.

Designs Single case-based operative video.

Setting Tertiary center with dedicated skull base team.

Participants The patient is a 50-year-old left handed male with a history of a remote left Bell's palsy, left sudden sensorineural hearing loss, and a rapidly progressive facial nerve paralysis. His balance was impaired, and his videonystagmography showed a significant left sided peripheral vestibular weakness. Computed tomography (CT) scan showed an erosive lesion of his left temporal bone involving the cochlea and semicircular canals, and magnetic resonance imaging (MRI) showed a T2 hyperintense lesion with restricted diffusion and no enhancement on postcontrast T1 sequences.

Main Outcome Measures Gross total resection of the epidermoid, recovery of facial nerve function, balance improvement.

Results The patient underwent resection via a transcochlear approach. The tumor involved the epitympanum and eroded the semicircular canals, vestibule, and basal turn of the cochlea. Gross total tumor resection was attained. The facial nerve was isolated in the mastoid and tympanic segments, traced proximally to the geniculate ganglion, and then into the internal auditory canal (IAC). The nerve was discontinuous in the distal IAC and a reactive neuroma was resected. The facial nerve was mobilized and an end-to-end coaptation was performed in the CPA using a collagen tubule. The 3-month postoperative MRI showed no residual or recurrent disease. His postoperative balance was improved. Partial facial nerve recovery is not expected prior to 9 to 12 months.

The link to the video can be found at: https://youtu.be/C6N8qPwBt2Y.
Surgical Management of Comminuted, Displaced Greater Tuberosity Fractures: A New Technique of Subacromial Spacer on Top of Double-Row Suture Anchor Fixation
Authors: Naggar Leslie
Published: October 2018

Arthroscopic treatment of greater tuberosity (GT) fractures has been previously described. Arthroscopy allows identifying and addressing coexisting injuries, such as rotator cuff tears, labrum, or superior labrum anterior and posterior lesions, which are often present. Fracture comminution precludes the use of rigid fracture fixation with screws and arthroscopic rotator cuff repair is performed instead. Recent articles have depicted the role of the balloon-shaped subacromial spacer in massive and irreparable rotator cuff tears. The purpose of this technical report is to outline another use of the spacer in patients with a GT fracture. The concept is to leverage the advantage of the compression effect of the subacromial spacer to prevent displacement of the GT fracture and allow early active shoulder rehabilitation, especially in comminuted or eggshell fractures when rigid fixation is not feasible.
Endovascular Management of Nonvariceal Upper Gastrointestinal Bleeding
Authors: Vij Arjun , Kapoor Baljendra , McLennan Gordon , Partovi Sasan
Published: October 2018

Nonvariceal upper gastrointestinal bleeding (UGIB) is associated with significant morbidity and mortality among hospitalized patients and thus presents a treatment challenge for the interventional radiologist. Common causes of nonvariceal UGIB include peptic ulcer disease, Mallory–Weiss tear, erosive inflammatory changes, ulcer disease, malignancy, and vascular malformations. Noninvasive imaging workup for this condition may include computed tomography angiography and tagged red blood cell scan. Invasive angiography allows for both the diagnosis and endovascular treatment of nonvariceal UGIB. Transcatheter embolization can be performed using a variety of embolic agents, such as coils, vascular plugs, and Gelfoam. For patients with negative angiography results despite the presence of clinically and endoscopically significant UGIB from a known source such as gastric ulcer or duodenal ulcer, the left gastric or gastroduodenal artery can be empirically embolized. In high-risk patients with multiple comorbidities who have failed endoscopic therapy, endovascular embolization is associated with lower complication rates compared with open surgery. In this review, we discuss current management strategy and endovascular techniques for the management of the nonvariceal upper GI hemorrhage.
In-Hospital Falls at the Department of Otorhinolaryngology
Authors: Kimura Toshiya , Miura Makoto , Gyo Kumiko , Yamada Koichiro , Honda Keigo , Hayashi Yasuyuki , Tanigami Yuki , Nakahira Mai , Ikeda Hiroki
Published: October 2018

A fall accident is an event that is associated with many disadvantages. In our hospital, 5,259 fall cases have been reported over the past 7 years according to our incident reports, and account for 16.5% of all incident reports. We conducted a detailed examination of 120 of these fall cases at the Department of Otolaryngology. Most of all, “before and after excretion” is a common fall-outbreak-motive reason for falls in all departments. In the field of otolaryngology, “use of drugs” and “walking disorder” are frequently encountered reasons for a fall. Calculation of age-specific fall rates revealed two peaks: around 0 years old and after 80 years old. It is suggested that a fall is associated with a reduced ability for maintaining the standing position. A correlation has been reported between the fall rate and the average length of hospitalization. Both the length of hospitalization of 12.3 days and fall rate of 1.97 among the cases seen at the Department of Otolaryngology are lower than all courses that are in other fields, on average. In the patients seen at the Department of Otolaryngology, the fall rate rises significantly as the length of hospitalization increases. In the Department of Otolaryngology, the fall rate of the malignancy group is high (2.91), irrespective of the treatment regimens. Each of the three items—“14 hospitalization days or more,” “65 years old or older,” and “malignancy”—contributes to falls in patients seen at the Department of Otolaryngology, and multivariate analysis revealed a particularly strong contribution of the previous two items. In elderly patients with expected long-term hospitalization, it is necessary to proactively attempt risk reduction; we first make all patients aware of the risk of long-term hospitalization at the first examination, and divide length of stay into multiple times. We review the assessment score after reexamining the “disease severity” and “performance status” as risk factors for falls, and want to realize more efficient measures for preventing falls in the future.
Investigation of harmonic distortions in photovoltaic integrated industrial microgrid
Authors: Aziz Tareq , Ahmed Mushfiqul , Nahid-Al-Masood
Published: October 2018

Due to the abundance of power electronic appliances, harmonic distortion has become one of the growing power quality concerns in recent years. Harmonic distortion is also caused by the nonlinearity of other power equipment such as transformers and rotating machines. Power systems, rich in harmonics, offer poor power factor and hence low efficiency operation. Due to the large concentration of nonlinear loads such as motor drives, investigation of harmonic distortion in industrial systems is getting special attention. Widespread integration of solar Photovoltaic (PV) systems into distribution systems brings additional challenges to the existing power quality scenario. Inclusion of solar PV systems in an industrial microgrid equipped with a large share of motor drives results in a significant increase in existing Total Harmonic Distortion (THD). To better understand the above issues, a methodology is proposed in this paper to identify the most suitable PV placement topology between the two schemes (namely, centralized and distributed) in terms of THD performance. Also, a technique is developed to estimate the maximum PV penetration level by maintaining the THD within the given acceptable limit. The proposed methodologies are applied to an industrial distribution system under various operating conditions.
Gallium clustering and structural effects of hydrogenation in InGaN/GaN nanostructures
Authors: Ciatto Gianluca , Pettinari Giorgio , Polimeni Antonio
Published: October 2018

We addressed the issue of atomic ordering in a series of In-rich InxGa1−xN epilayers grown on a GaN/AlN/sapphire(0001) epitaxial template by quantitatively measuring the Ga-cation coordination in the second atomic shell of Ga. We used Diffraction Anomalous Fine Structure Spectroscopy (DAFS) at the Ga K-edge to select the signal coming from the Ga atoms in the epilayer and eliminate any contribution from the buffer layer. DAFS measurements were also performed on hydrogenated epilayers in order to investigate the possible formation of Ga-H complexes. We find that deviation from cation random distribution in the form of Ga clustering is present in both untreated and hydrogenated samples and that in the latter ones the second atomic shell around Ga is modified, suggesting an additional perturbation of the cation sublattice related to hydrogen. However, comparing the present results with In K-edge x-ray absorption spectra previously reported, we conclude that the formation of Ga-H complexes vs. In-H ones is unlikely. Cation clustering has to be anyway taken into account as a possible channel playing in the determination of the optical bandgap of these technology-oriented semiconductors.
Reversible metallization and carrier transport behavior of In2S3 under high pressure
Authors: Li Yuqiang , Gao Yang , Xiao Ningru , Ning Pingfan , Yu Liyuan , Zhang Jianxin , Niu Pingjuan , Ma Yanzhang , Gao Chunxiao
Published: November 2018

The electrical transport properties of indium trisulfide (In2S3) under high pressure were investigated using the in situ Hall-effect and temperature dependent resistivity measurements. Resistivity, Hall coefficient, carrier concentration, and mobility were obtained at pressures up to 41.6 GPa. Pressure induced metallization of In2S3 occurred at approximately 6.8 GPa. This was determined by measuring temperature dependent resistivity. The metallization transition was also determined from compression electrical parameters, and the decompression electrical parameters indicated that the metallization was a reversible transition. The main cause of the sharp decline in resistivity was the increase in carrier concentration at 6.8 GPa. Superconductivity was not observed at the pressures (up to 32.5 GPa) and temperatures (100–300 K) used in the experiment.