bluuebunny/crossref_metadata_2025 huggingface dataset:
Data mining and data-driven modelling for Air Handling Unit fault detection
Authors: Gao Tianyun , Boguslawski Bartosz , Marié Sylvain , Béguery Patrick , Thebault Simon , Lecoeuche Stéphane
Published: August 2019

Data-driven automatic fault detection and diagnostics (AFDD) have gained a lot of research attention in recent years. Many existing solutions need to learn from the fault operation data to be able to diagnose the faults. However, these data are usually not available in buildings. In this study we present a data-driven AFDD solution for Air Handling Units (AHUs). The solution consists of three levels of fault detection that require different levels of data availability: the first level is daily energy benchmarking; the second level is control performance evaluation; and the third level is data-driven modelling of mechanical systems. The method is applied to two case studies: experimental data from ASHRAE project 1312-RP, and real-life operation data of an office building in France. These tests show that the solution is able to isolate control faults and mechanical faults of individual components, by learning from normal operation data only.
Fault detection in HVAC systems using a distribution considering uncertainties
Authors: Miyata Shohei , Akashi Yasunori , Lim Jongyeon , Kuwahara Yasuhiro
Published: August 2019

Detecting and diagnosing faults that degrade the performance of heating, ventilation, and air conditioning (HVAC) systems is very important for maintaining high energy efficiency. The performance of HVAC systems can be evaluated by analyzing monitored data. However, data from a HVAC system generally includes uncertainties, which renders monitored data less reliable. Then, we focused on uncertainties and a calculated performance distribution. The uncertainties from sensors, actuators, and communications were modelled stochastically and were incorporated into a detailed simulation. The system coefficient of performance (SCOP) was used as a performance indicator, which is defined as the ratio of suppled heat to total power consumption. The SCOP distributions over the course of representative weeks in 2007 and 2015 were calculated by repeating the simulation 2,000 times with different uncertainties. Regarding the results for 2015, the 90% confidence interval of the distribution was -4.9% to 5.8% from the SCOP value without uncertainties. The SCOP value determined from the monitored data in 2015 was outside of the low end of the distribution though that in 2007 was inside of the interval. Through an analysis of the monitored data, it was found that fault detection is possible by comparing the monitored data with the distribution.
Mixing Loop Control using Reinforcement Learning
Authors: Overgaard Anders , Skovmose Kallesøe Carsten , Dimon Bendtsen Jan , Kongsgaard Nielsen Brian
Published: August 2019

In hydronic heating systems, a mixing loop is used to control the temperature and pressure. The task of the mixing loop is to provide enough heat power for comfort while minimizing the cost of heating the building. Control strategies for mixing loops are often limited by the fact that they are installed in a wide range of different buildings and locations without being properly tuned. To solve this problem the reinforcement learning method known as Q-learning is investigated. To improve the convergence rate this paper introduces a Gaussian kernel backup method and a generic model for pre-simulation. The method is tested via high-fidelity simulation of different types of residential buildings located in Copenhagen. It is shown that the proposed method performs better than well tuned industrial controllers.
Predicting personal thermal preferences based on data-driven methods
Authors: Aguilera José Joaquín , Toftum Jørn , Berk Kazanci Ongun
Published: August 2019

One of the prevalent models to account for thermal comfort in HVAC design is the Predicted Mean Vote (PMV). However, the model is based on parameters difficult to estimate in real applications and it focuses on mean votes of large groups of people. Personal Comfort Models (PCM) is a data-driven approach to model thermal comfort at an individual level. It takes advantage of concepts such as machine learning and Internet of Things (IoT), combining feedback from occupants and local thermal environment measurements. The framework presented in this paper evaluates the performance of PCM and PMV regarding the prediction of personal thermal preferences. Air temperature and relative humidity measurements were combined with thermal preference votes obtained from a field study. This data was used to train three machine learning methods focused on PCM: Artificial Neural Network (ANN), Naive-Bayes (NB) and Fuzzy Logic (FL); comparing them with a PMV-based algorithm. The results showed that all methods had a better overall performance than guessing randomly the thermal preferences votes. In addition, there was not a difference between the performance of the PCM and PMV-based algorithms. Finally, the PMV-based method predicted well thermal preferences of individuals, having a 70% probability of correct guessing.
Assessment of Micro-Organism Growth Risk on Filters with Machine Learning
Authors: Hantsch Andreas , Döge Sabine
Published: August 2019

Modern buildings usually have a practically air-tight envelope. Therefore, mechanical ventilation is very often necessary. A crucial part of the system is the filter which allows to create an atmosphere which is free of dust, aerosols, and pollen. As organic material accumulates on the filter surface, the risk of micro-organism growth rises. This may yield health issues especially for the occupants of buildings in humid regions. For this purpose, a test filter with electrodes has been designed which allowed to measure its electro-magnetic properties, such as resistance, capacitance, and impedance as an indicator for the micro-organism growth risk. After some preliminary tests, electrodes of stainless steel and the electrical capacitance have been selected due to their best durability and signal-to-noise-ratio. The test filter has been implemented in the HVAC system of the institute in order to aggregate data for different abnormal and normal operation data. A machine learning algorithm has been trained successfully to detect anomalies of the filter behaviour and therefore provided more insight than pressure drop measurement alone. Finally, the change intervals of the filter could be adapted to the real degree of pollution without the requirement for visual observation in order to provide best air conditions.
Integration of operational data in building information modelling: From ontology to application
Authors: Mahdavi Ardeshir , Wolosiuk Dawid
Published: August 2019

Building design, construction, and operation has been suggested to benefit from comprehensive and well-formed repository of associated information. Building Information Modeling (BIM) has pursued the supposition that repositories could facilitate seamless exchange of information amongst the multiple stakeholders in the building delivery process. Related research and development efforts have primarily focused on representation of buildings’ geometry and specifications of their constituent structural and constructional components. More recently, representations of building environmental control equipment and systems have begun to become incorporated in BIM applications. Ongoing work in this area has likewise targeted development of common schemes to incorporate, in BIM, buildings’ sensory networks and elements that serve, for instance, the operation of HVAC (Heating, Ventilation, and Air-Conditioning) systems. To achieve these targets, comprehensive and robust ontologies of building monitoring data and building performance indicators are essential. In the present contribution, we first present a recently introduced original proposal for such ontologies, covering data regarding dynamic data relevant to state, operation, and performance of buildings. This ontology was developed based on an extensive review of building monitoring data and performance indicator catalogues in thermal, air quality, visual, and acoustical domains. The ontology’s structural core basically involves a systematic specification of the generic attributes of building performance variables. We then illustrate various benefits and applications of this ontology. It is shown to support data quality check, data visualization, building operation optimization, and preventive building systems maintenance. It can also add to the clarity of building performance requirements specifications, advance the understanding of building performance principles in educational and training settings, and provide and early integration of buildings’ operational attributes in BIM applications.
Operation strategies to achieve low supply and return temperature in district heating system
Authors: Li Haoran , Nord Natasa
Published: August 2019

Low temperature is the most significant feature of the future district heating (DH) - the 4th generation district heating (4GDH). The revolutionary temperature level (50–55/25°C) will improve the efficiency of heat sources, thermal storages, and distribution systems, meanwhile, bring huge potentials to renewable energies. One challenge of transition to the future DH is the compatibility of current customer installations and the future temperature level. The aim of this study was to find the temperature potential of Norwegian residential buildings for the future DH system. A reference apartment was created, and typical space heating (SH) system was designed. A detailed building and SH system model were built in Modelica® language, and simulation was conducted via Dymola environment. Different operation strategies: PI control of the supply temperature, weather compensated control of the supply temperature, and PI control of the return temperature were tested. The results of the study showed the average supply temperature could be as low as 56~58°C, and only limited time the temperature was above 60 °C, when the controlled supply temperature strategies were applied. For the case with controlled return temperature strategies, the average return temperature were 30 and 37°C, while the average required supply temperature could be 72 and 94°C. The conclusion was that the low supply temperature could be achieved through optimized operation strategies. Whereas, the low return temperature was not able to be achieved only by improving the operation strategy.
User-oriented verification of automation stations
Authors: Ulmer Ralf , Müller Jochen
Published: August 2019

Building automation systems are used to meet the increasing requirements for energy efficiency and sustainability of buildings. In such systems, BACnet has established itself as the standard communication protocol for communication between devices from different manufacturers. In order to ensure conformity with the BACnet standard, the devices are certified for conformity. In practice, however, the implementation depth described in the standard profiles is not sufficient for operating a system. As a result, many users demand an extended implementation depth of the BACnet protocol. In most cases, an AMEV certificate is sought, which extends the BACnet objects and their properties in comparison to the standard certification. Despite the BACnet standard certification and the fulfilment of the AMEV test certificate, problems often occur during the operation of building automation systems. These problems can be attributed to the fact that neither the functionality nor the performance of automation stations are determined. In addition, special user requirements are not checked before commissioning a building automation system. For this reason, a model was developed with the help of which a pre-commissioning of the automation station is possible in order to automatically check it for errors and special user requirements before commissioning. Initial tests of automation stations revealed that some user requirements were not met.
Numerical investigation of the energy flexibility of different heating and cooling systems
Authors: Loukou Evangelia , Liu Mingzhe , Johra Hicham , Heiselberg Per , Dia Bianca A. , Clementsen Rógvi K. D.
Published: August 2019

The significant expansion of intermittent renewable energy sources can compromise the stability of energy grids due to the mismatch between instantaneous energy use and production. Buildings have a large potential for energy storage and demand-side management, which can offer energy flexibility to a Smart Grid system. Smart control of heating, ventilation and air conditioning systems is a great solution for improving flexible energy use, load shifting and power peak shaving. This numerical study compares the energy flexibility potential of three different heating and cooling systems implemented in a nearly zero-energy office building. The energy flexibility strategy consists in the modulation of heating / cooling indoor temperature set points according to an energy price signal. The energy flexibility assessment was performed based on the energy shifting ability, indoor thermal comfort level and economic benefits. This article establishes a better understanding of the flexibility potential of common and innovative heating / cooling technologies. Lindab Solus system has the highest load shifting ability with a flexibility index of 67.41%, followed by the radiator heating system, scoring a 59.92%, and the underfloor heating system with 56.65%. It is clear that the selection between different heating/ cooling systems can have a great impact on the energy flexibility of the grid system.
Grid-edge technology - Exploring the flexibility potential of a heat pump and thermal energy storage system
Authors: Schellenberg Christoph , Dimache Laurentiu , Lohan John
Published: August 2019

Grid-edge technologies (GET) enable and amplify the impact of three emerging energy system trends: electrification, decentralisation, and digitalisation. Smart grid integrated heat pumps with thermal energy storage enable both the electrification of heating and decentralised demand response. Such power-to-heat technologies simultaneously decarbonise heating and facilitate the grid integration of more variable renewable electricity in a cost-effective manner. This may help to explore and exploit untapped wind generation potential. This study explores the flexibility potential of a domestic scale heat pump with thermal energy storage in a typical Irish home in December. The system is simulated to investigate demand-side flexibility and sensitivity to both heat pump and thermal storage capacities for three days with wind energy shares of 7%, 25%, and 60%. Using real-time electricity prices and optimising for operational cost, the implicit demand flexibility potential is quantified with different combinations of heat pump power and storage capacity. The results suggest that 33-100% of critical loads can be shifted dynamically to low-cost periods. Optimised system design depends on local climate, heat demand profile, optimisation horizon, and the type of heat pump. Optimisation with genetic algorithm yielded near-global optimal results approximately 40 times faster than with exhaustive enumeration.
The Regional Virtual Power Plant – Experiences of a field test
Authors: Seifert Joachim , Seidel Paul , Werner Jens , Meinzenbach Andrea
Published: August 2019

Due to the energy system transformation initiated by the German government, the energy supply structures will be much more decentralized in the future. In the following publication the methodology of a Regional Virtual Power Plant will be described and first results from a field test will be presented.
Optimal control of secondary side supply water temperature for substation in district heating systems
Authors: Hou Juan , Li Haoran , Nord Natasa
Published: August 2019

Low temperature is the most significant feature of the future district heating system- the 4th generation district heating (4GDH). However, a widely used control strategy for supply water temperature in substation is weather- compensated control. It is a feedforward control without any dynamic information about buildings, which can lead to higher or lower supply water temperature. This paper presents model predictive controller (MPC) applied to the supply water temperature control for substations in district heating systems. MPC is an advanced control technique, which can make full use of dynamic information of buildings to determine the optimal supply water temperature of substations. In this paper, a multiple inputs and single output dynamic model was identified by subspace methods. Two different MPC controllers were designed in Simulink. The MPC controller 1 focused on keeping indoor air temperature at reference values. The MPC controller 2 focused on both keeping indoor air temperature at reference values and tracking the minimum supply water temperature in order to find the temperature potential for the future DH systems. Both of the MPC controllers proved to have a better tracking effect for indoor air temperature and lower average supply temperatures compared to weather- compensated. The MPC controller 2 could further lower supply water temperature compared to the MPC controller 1 by tracking minimum supply water temperature in its objective function. The average supply water temperatures for the weather- compensated, the MPC controller1, and the MPC controller 2 were 52°C, 51°C and 50°C, respectively. The results showed that MPC has a great potential in the area of supply water temperature control of the district heating systems.
Energy Consumption of the VAC System for Subway Stations: A Model Based on Theoretical Analysis and its Engineering Application
Authors: Su Ziyi , Li Xiaofeng
Published: August 2019

With the continuous expansion of the subway scale, the amount of energy consumed by subway stations has become a concern, among which the energy consumption of ventilation and air-conditioning (VAC) system takes a large proportion. There are many former studies concentrated on this topic. However, the problems of previous studies are obvious, such as time-consuming and unclear practical meaning of the energy model. This study has proposed a model based on theoretical analysis and focused on the energy model of the VAC system for underground subway stations. The energy model consists of the model for the cooling load and the energy efficient ratio. In this model, basic station information and environmental parameters should be tested and inputted. Then with the help of simple simulation tools, Subway Thermal Environment Simulation Software (STESS), the energy consumption of the station can be fast estimated by the model proposed in this paper. This model can be applied to determine the energy-saving potential of changing operation pattern and adopting energy-saving technologies, which gives guidance to the energy-saving retrofit of the station.
Investigation of Ventilation Behaviors in Mechanically Ventilated Residential Buildings in China
Authors: Qi Yue , Liu Junjie , Dai Xilei , Zhao Lei , Lai Dayi , Wei Shen
Published: August 2019

Mechanical ventilation system provides a more reliable, controllable, and comfortable way of ventilation than natural ventilation through an opened window. However, the operation of mechanical ventilation system cost energy. This study investigated the usage of natural and mechanical ventilation in 46 apartments in ten cities across five different climate zones in China by on-site monitoring and questionnaire survey. On average, the daily natural and mechanical ventilation durations were 11 hours and 7.2 hours, respectively. Large differences existed among climate regions and seasons. From north to south, as the climate became warmer, the usage of natural ventilation increased. From seasonal perspectives, natural ventilation duration was the longest in summer and the shortest in winter. The trend of mechanical ventilation usage was opposite to that of natural ventilation. Generally, as the outdoor air temperature increased, the duration of natural ventilation increased and the duration of mechanical ventilation decreased. This study proposed an outline to use thermal comfort, health, and energy saving as three motivations to analyze ventilation behaviors. Based on the obtained results, suggestions were made for achieving healthy, thermally comfortable, and energy efficient ventilation in residential buildings.
Studies of Subjective Sleep Thermal Comfort and Adaptive Behaviors in Chinese Residential Buildings in Nine Cities
Authors: Hong Weiping , Liu Junjie , Pei Jingjing , Lai Dayi
Published: August 2019

Sleep thermal comfort greatly impacts the quality of sleep. For residents from different climate regions, their level of sleep thermal comfort may have a large difference due to the variations in climate, and other adaptive factors such as the changes in bedding system insulation, the use of air conditioners, and the opening of windows. To study the thermal comfort and adaptive behaviors of Chinese residents in different regions during sleeping period, this study conducted a long-term survey in nine cities in China from February 2018 to September 2018. For northern residents, they achieved a slight higher than neutral sleep thermal sensation in winter due to the use of central heating system. In summer, the sleep thermal sensation of severe cold (SC) region residents had a significant increase. In the south, although without central heating in winter, southern residents maintained a near neutral thermal sensation, partly because of the high bedding system insulation. Although the summer night outdoor air temperature was high in hot summer and cold winter (HSCW) and hot summer and warm winter (HSWW) regions, the occupants from the two regions actively used the air conditioners to help achieving sleep thermal comfort. The results of this study provide valuable information for designers, researchers, and policy makers to create a comfortable nighttime thermal environment in China.
Assessment of method for measuring clo value using human body – Assessment of method for measuring clo value that assumes human body temperature adjustment
Authors: Yamato Yoshiaki , Kurazumi Yoshihito , Fukagawa Kenta , Tobita Kunihito , Kondo Emi
Published: August 2019

In order to make it possible to measure the clo value in various postures, we are studying the measurement method using the human body. Our previous researches showed that clo value measured with the human body is less than that measured with a “constant temperature control”-type thermal manikin. In our previous experiments, human body changes its skin temperature in response to the amount of clothing or changes in the temperature to maintain heat loss, while a “constant temperature control”-type thermal manikin changes its heat loss in response to the temperature or amount of clothing. Human body reaction is similar to “constant heat dissipation” -type thermal manikin. In order to improve the clo value measurement method using the human body, clo value of same clothing by thermal manikin which changed control method to “constant temperature” and “constant heat dissipation” were measured. Relational expressions of thermal insulation of clothes measured by different control methods were shown.
Mathematical Simulation of the Thermodynamic Processes Associated with the Vapour-Injected Scroll Compressor
Authors: Zabet Ion , Tarlea Gratiela Maria
Published: August 2019

Both the major energetic crisis and the global warming, which influence the worldwide economy and the future of the society, determine the development of energetic and ecological performances of both the refrigeration equipment and air conditioning systems. Thus, there is a worldwide supported effort made in order to decrease the carbon dioxide emissions resulted from the burning of fossil fuels and the other greenhouse effect gas emissions. This article presents a refrigeration system design model using a vapour injection scroll compressor and tube in tube evaporators working with refrigerant R407C. The refrigerant circuit comprises of a main evaporator, a secondary evaporator (for the injection process), scroll compressor, condenser and five expansion valves. Furthermore it uses R407C as refrigerant. The secondary refrigerant for both the main and the secondary evaporator is a 50% concentration solution of propylene-glycol and water. Secondary circuit comprises of a pump, an electric boiler, an expansion vessel and a by-pass circuit made of many stop valves. The condenser is cooled with mains water.
A study on the Contamination of Microbial in a Geothermal Exchanger Pipe by Lab-experiment
Authors: Kim Hyuntae , Koganei Makoto
Published: August 2019

Recently, since global warming has continued, reduction of greenhouse gas CO2 is required. CO2 emissions in the civil area sectors in Japan account for approximately 30%, which is about one-third of the whole of Japan. Therefore, reduction of energy consumption in houses, office and etc. is obviously required. In order to reduce energy consumption of buildings, high-efficiency of machinery, high-insulation, high-airtightness, and use of renewable energy are mentioned. Especially, use of geothermal energy which has almost constant temperature throughout the year has been drawing attention. However, in case of geothermal ventilation system, a fungi, dust, pollen and etc. derived from the outside air are taken directly into the pipe. It is concerned that they cause contamination inside the pipes and breeding of molds, which may lead to odors. The present study analyzed the contamination degree of the pipe surface in the geothermal ventilation system and proposed cleaning frequency in the pipe, cleaning method and so on.
Field measurement of PM2.5 concentration in office buildings
Authors: Kagi Naoki , Yanagi U , Azuma Kenichi , Kim Hoon
Published: August 2019

The characterization of indoor PM2.5 has been concerned about health effects. PM2.5 in indoor air is affected by not only indoor emissions but also penetrations from outdoor air. Therefore, it is important for indoor PM2.5 to take into account of penetration factors of PM2.5 through air conditioning units in buildings. This study aimed at investigating PM2.5 concentrations and I/O ratios (indoor/outdoor concentration) in office buildings. As a result, the relationships between PM2.5 concentrations or I/O ratios and building characteristics could be classified as the types of buildings, such as specific or non-specific, and air conditioning units, such as the individual or central system. The I/O ratio for the specific buildings, over 3,000 m2 of total floor area and buildings that had the central air conditioning unit was relatively low because of medium performance filter in air conditioning units.
The Stern-Gerlach experiment re-examined by an experimenter
Authors: Schmidt-Böcking Horst
Published: August 2019

The historic Stern-Gerlach experiment (SGE), which was performed in 1922 in Frankfurt, is reviewed from an experimental point of view. It is shown that the SGE apparatus is a purely classical momentum spectrometer, in which the trajectories of particles are measured. With modern detection devices the passage of each single atom can be identified and its trajectory in the magnetic field precisely determined. At the time of their experiment Stern and Gerlach achieved a hitherto unprecedented momentum resolution corresponding to an energy resolution of one μeV.
Design and shape optimization of MR brakes using Nelder–Mead optimization algorithm
Authors: Bazargan-Lari Yousef
Published: August 2019

Magnetorheological (MR) brakes have attracted many attentions for controlling mechanical systems such as robots, e-bicycles, and haptic devices. A large number of researchers have delved into enhancing MR brake effectiveness. Herein, a new MR brake is proposed in which the braking torque is improved and the configuration is simplified. Numerical simulations were based on finite element method (FEM) was employed to achieve the brake model. In order to verify the obtained results, they were compared with the available ones in the literature and they have a good agreement with each other. Then, the proper brake model was optimized using Nelder–Mead optimization algorithm. Results demonstrated 215.75 N m braking torque in the present prototype which is almost 73% higher than the previous model in the literature. In addition, the brake could induce about 125.06 N m torque on the brake disk with nearly half of the coil current used in the previous work. Besides, increase in the number of the disks was not necessarily improved braking efficiency and the size of the MR fluid gaps also influenced the brake operation. In addition, the proposed model in this paper has ease manufacturing procedure which would reduce the fabrication costs.
Use of phase change materials in concrete: current challenges
Authors: Adesina Adeyemi
Published: August 2019

Sustainability awareness in the building industry has increased in recent years, and several initiatives have been developed. One of the areas gaining attention recently is the application of phase change materials (PCMs) in concrete. PCMs are materials capable of storing and releasing energy based on the temperature of the environment in which they are situated. This capability makes them provide heat during cold times, and absorb heat when the temperature is higher. As concrete is the most used building material in the world, the use of PCMs in concrete will be a great way to widen the application of PCMs. However, as the composition of concrete determines its properties; hence, the use of PCM in concrete can be detrimental to the properties of concrete. Some of the negative effects on the properties of concrete include reduced mechanical properties and corrosion of reinforcements. In addition, PCMs suitable for concrete are not readily available in the market, and extremely expensive when available. Also, lack of long-term data on the effect of PCM on concrete's durability has discouraged stakeholders to accept the use of PCMs in concrete. This paper explored the current challenges faced by the application of PCMs in concrete which, and possible opportunities that will open more pathway for extensive research and applications of PCM in concrete. It was concluded that the use of right type and proportion of PCM in concrete can result in similar strength to those of control samples. Also, certain methods of incorporating PCMs into the concrete were found to be more effective. Therefore, it is imperative that building engineers carry out initial tests to determine the most appropriate incorporation method to be used. Finally, huge energy savings can be achieved through the use of PCM in concrete without any significant reduction in mechanical strength.
Simultaneous control on lead time elements and ordering cost for an inflationary inventory-production model with mixture of normal distributions LTD under finite capacity
Authors: Tahami Hesamoddin , Mirzazadeh Abolfazl , Gholami-Qadikolaei Aref
Published: August 2019

The significance of inflation and time value of money in inventory/production systems is indisputable for modern decision makers. Consequently, the paper aims to study the influence of inflationary condition on a stochastic continuous review integrated vendor–buyer inventory system in the presence of a multilevel reorder strategy for the system. It is considered that lead time components and ordering cost are controllable. Lead time is decomposed into its components: set-up time, production time and transportation time. Based on lead time components, demand during the lead time for different batches is assumed to be a mixture of normal distributions. The objective is to minimize joint inventory expected cost by simultaneously optimizing ordering quantity, reorder points of different batches, ordering cost, setup time, transportation time, production time and a number of deliveries under space constraint while the lead time demand follows a normal distribution. To minimize the expected inventory cost, a Lagrange multiplier method is applied in order to solve the problem, and an iterative algorithm is designed to find optimal values. The behavior of the model is illustrated in numerical examples. It was found that for a fixed value of transportation time, setup time and number of batches, with an augment in inflation rate, the two optimal reorder points for different batches were increased. Also, optimum joint expected annual cost with inflation for two kinds of customers’ demand is larger than one kind of customers’ demand. Furthermore, sensitivity analysis and managerial insights are given to show the applicability of the model.
It’s never too late to become an Ironman – The example of an 85-year-old triathlete
Authors: Lepers Romuald , Stapley Paul J
Published: August 2019

This study aimed to analyse the performance of Hiromu Inada (HI), an 85-year-old triathlete, who became the oldest athlete in the world to complete the famous Hawaii Ironman triathlon consisting of a 3.8 km swim, 180-km cycle and 42-km run. HI swam in 1 h 51 min, cycled in 8 h 02 min, ran in 6 h 28 min and took 31 min for his transitions, for a total time of 16 h 53 min. Compared to the winner’s speed, HI was 55, 47 and 58% slower in swimming, cycling and running, respectively. For the same age-group category (i.e. 85–89 years), the age-related decline in performances of HI are more pronounced compared to the age-related decline in performance of shorter duration endurance single discipline such as 1500-m swimming, 1-h track cycling or marathon running. To our knowledge, the performance of HI represents the first written observation of a master athlete older than 85 years old who officially finished an ultra-endurance event. The HI case is a clear example that humans can retain remarkable functionality until the end of their life span… if they train for it.
Editorial
Authors: Hellmich Bernhard
Published: August 2019

Noch bis zur Jahrtausendwende basierten die Empfehlungen zur Behandlung systemischer Vaskulitiden überwiegend auf der retrospektiven Beschreibung von Kohorten einzelner größerer Zentren sowie auf wenigen und nach heutigen Standards qualitativ oft minderwertigen prospektiven Studien. Neue Erkenntnisse zur Immunpathogenese der Vaskulitiden, die Entwicklung neuer pathogenetisch begründeter Therapieverfahren und der Zusammenschluß einzelner Zentren zu multinationalen Studiengruppen ermöglichte in den vergangenen 15 Jahren die Durchführung qualitativ guter und aussagekräftiger Therapie- und Diagnosestudien. Diese neuen Studiendaten bildeten dann in jüngster Zeit die Grundlage für die Formulierung nationaler und internationaler Leitlinien und Empfehlungen (u. a. der EULAR und der DGRh) zu den ANCA-assoziierten Vaskulitiden, den Großgefäßvaskultiden (v. a. der Riesenzellarteriitis) und dem M. Behcet 1
2
3
4. Auch nach Erscheinen der genannten noch jungen Empfehlungen wurden bereits wieder neue Studiendaten publiziert, welche die Leitlinienempfehlungen teils bestätigen, teils aber auch widerlegen. Das vorliegende Heft mit dem Themenschwerpunkt Vaskulitiden soll diese neuesten Erkenntnisse zur Riesenzellarteriitis, den ANCA-assoziierten Vaskultiden und dem M. Behcet vor dem Hintergrund der aktuellen Leitlinien einordnen.
Risk of Thyroid Disorders in Patients with Gout and Hyperuricemia
Authors: Xu Jian , Wang Bin , Li Qian , Yao Qiuming , Jia Xi , Song Ronghua , Zhang Jin-an
Published: August 2019

The risk of thyroid autoimmunity and thyroid dysfunction among patients with gout and hyperuricemia has not been well defined. This study was undertaken to examine the impact of gout and hyperuricemia on risk of thyroid disorders including thyroid autoimmunity and thyroid dysfunction. A population-based cross-sectional study was conducted to assess the risk of thyroid autoimmunity and thyroid dysfunction related to gout and hyperuricemia, which included 115 gout patients, 439 hyperuricemic patients, and 2 254 individuals without gout and hyperuricemia. A systematic review and meta-analysis of 14 observational studies was also done to systematically evaluate the risk of thyroid dysfunction among patients with gout and hyperuricemia. Findings from the cross-sectional study suggested a significantly increased risk of hypothyroidism among female gout patients (OR=2.44, 95% CI 1.15–5.17, p=0.02). Besides, gout could also substantially increase risk of Hashimoto’s thyroiditis in women (OR=3.15, 95% CI 1.53–6.49, p=0.002). The meta-analysis proved a considerably increased risk of hypothyroidism among both gout patients (OR=1.51, 95% CI 1.23–1.85, p<0.001) and hyperuricemic patients (OR=1.34, 95% CI 1.11–1.61, p=0.002). Moreover, this meta-analysis also suggested that gout could also significantly increase the risk of hyperthyroidism (OR=1.25, 95% CI 1.06–1.48, p=0.01). The findings from the study suggest increasing risk of hypothyroidism and Hashimoto’s thyroiditis among gout patients. Moreover, gout but not hyperuricemia is linked to increased risk of hyperthyroidism. More studies are warranted to elucidate the influence of gout and hyperuricemia on thyroid disorders.
Riesenzellarteriitis: Aktuelle Erkenntnisse zu Epidemiologie, Pathogenese, Diagnostik und Therapie
Authors: Keyßer Gernot
Published: August 2019

Als Riesenzellarteriitis (RZA, englisch giant cell arteritis, GCA) bezeichnet man eine Vaskulitis der großen Gefäße, also der Aorta sowie der aortennahen Gefäße erster und zweiter Ordnung. RZA sind in Manifestation und Verlauf vielgestaltige Erkrankungen, die häufig hohe Ansprüche an die Diagnostik und die langfristige Betreuung der Patienten stellen. Fortschritte in Ultraschall-, MRT- und Positronen-Emissionstomografie haben die Diagnostik erleichtert und den Blick für seltenere und ungewöhnliche Manifestationsformen geschärft, die früher oft unerkannt geblieben sind. Therapie der ersten Wahl sind auch heute noch Corticoide. Deren langfristige und hochdosierte Anwendung ist bei den meist älteren und oft polymorbiden Patienten nicht unproblematisch. MTX stellt eine sinnvolle Möglichkeit zur Corticoid-Einsparung dar. Die Einführung der Therapie mit Interleukin-6-Rezeptor-Antikörpern hat neue therapeutische Möglichkeiten für Patienten eröffnet, bei denen langfristige Steroidgaben gefährlich oder kontraindiziert sind. Hauptziel der Behandlung ist die Vermeidung von Komplikationen wie Erblindung, Gefäßverschlüssen oder Aneurysmata sowie die Verhinderung von Therapiekomplikationen.
Extraintestinale Manifestationen bei chronisch-entzündlichen Darmerkrankungen
Authors: Doßow Lauren , Arnim Ulrike von
Published: August 2019

Chronisch-entzündliche Darmerkrankungen (CED) umfassen die Colitis ulcerosa (CU) und den Morbus Crohn (MC) und stellen primär eine gastroenterologische Domäne dar. Neben gastrointestinalen Beschwerden erfahren allerdings bis zu 50 % der Patienten mit einer CED mindestens ein extraintestinales Symptom, was als extraintestinale Manifestation (EIM) bezeichnet wird.

Fast jedes Organsystem kann von einer extraintestinalen Manifestation betroffen sein. Die häufigsten extraintestinalen Manifestationen sind muskuloskelettal, gefolgt von Haut- und Augenbeteiligungen. Extraintestinale Manifestationen treten häufiger bei Morbus Crohn als bei Colitis ulcerosa auf. Die Symptome der extraintestinalen Manifestation können zu einer relevanten Einschränkung der Lebensqualität führen. Teilweise besteht eine Assoziation zur Krankheitsaktivität.

Chronisch-entzündliche Darmerkrankungen sind als Systemerkrankung zu betrachten. Daher profitieren die Patienten von einem interdisziplinären Diagnose- und Therapiekonzept. Bei extraintestinaler Beschwerdeanamnese bzw. Untersuchungsbefunden muss die extraintestinale Manifestation einer CED in Betracht gezogen werden und eine fachspezifische Mitbehandlung ist zu initiieren.

Ein Konsens über die Definition von extraintestinaler Manifestation und die Zuordnung von Krankheiten und Symptomen als extraintestinale Manifestation besteht noch nicht. Wünschenswert wären weitere Bestrebungen für eine exakte Definition.
Erste Ergebnisse: Vitamin-D-Versorgung bei Piloten und Luftfahrtpersonal der Bundeswehr
Authors: Pippig Torsten , Matthias Oertel , Zahedi Farzaneh
Published: August 2019

Die Hauptquelle des Menschen für Vitamin D ist die Eigensynthese in den oberen Hautschichten mithilfe des Sonnenlichts (80–90 %). 10–20 % des Vitamin-D-Bedarfs deckt der Mensch über die Ernährung. Ein 25-OH-Vitamin-D-Wert, das ist die Speicherform des VitD3, im Serum (i. S.) von mindestens 30 ng/ml gilt als Suffizienz, höhere Normwerte werden diskutiert. In dieser Arbeit werden die Vitamin-D-Werte im Serum von 2176 Probanden (lizenzpflichtiges und fliegendes Personal der Bundeswehr) im Untersuchungszeitraum vom 01. Dezember 2017 bis 30. November 2018 ausgewertet. 71,6 % aller Probanden (N = 1557) hatten einen Vitamin-D-Wert unterhalb des empfohlenen Normwerts > 30 ng/ml, 25,8 % (N = 648) der „gesunden“ Probanden hatten einen Vitamin-D-Mangel (< 20 ng/ml). In dieser Studie hatten das Alter, das Geschlecht, der Body Mass Index (BMI), Harnsäure (HSR) und C-reaktives Protein (CRP) sowie Dienst- beziehungsweise Wohnort in Deutschland (Postleitregionen) keinen Bezug zum Vitamin-D-Mangel. Die bekannten jahreszeitlichen beziehungsweise monatlichen Schwankungen, in Abhängigkeit der Sonnenstunden pro Monat, wurden auch in dieser Studie gesehen.
Synthesis of Esters from Stable and Convenient Sulfoxonium Precursors under Catalyst- and Additive-Free Conditions
Authors: Yuan Yang , Wu Xiao-Feng
Published: August 2019

A convenient and efficient procedure for the construction of esters from stable sulfoxonium ylides and alcohols has been developed. This protocol presents a broad substrate scope and good yields of the desired esters can be isolated. Notably, no catalyst, oxidant, base or any other additive is required.
Congenital Hepatic Vascular Anomalies
Authors: Chewning Rush H.
Published: August 2019

Congenital hepatic vascular anomalies, following the classification system originally proposed by Mulliken and Glowacki and subsequently developed by the International Society for the Study of Vascular Anomalies, are characterized as either tumors or malformations. The former includes infantile hemangioma, congenital hemangioma, angiosarcoma, and epithelioid hemangioendothelioma. The latter includes arterioportal fistula, portosystemic shunt, arteriovenous malformation, and venous malformation. Despite this well-established system, there still exists confusion in terminology that can lead to delayed diagnosis or improper treatment. Knowledge of the clinical presentation and imaging characteristics of these entities, as well as the nosologic system for vascular anomalies, is essential in arriving at the correct diagnosis, which in turn informs proper treatment.
Prophylactic Fucose can Alleviate Lipopolysaccharide-Induced Cholestatic Liver Injury in Neonatal Rats
Authors: Baysal Bora , Tüzün Funda , Engür Defne , Özbal Seda , Ergür BekirUğur , İşcan Burçin , Yücesoy Ebru , Duman Nuray , Özkan Hasan , Kumral Abdullah
Published: August 2019

Objectives Cholestasis is a common disease of the liver in premature infants and no specific preventive treatment is currently available. Fucose, one of the monosaccharide building blocks of human milk oligosaccharides, may prevent cholestatic hepatic injury by various mechanisms. The aim of this study was to investigate the protective effect of fucose treatment after endotoxin-induced cholestasis in a rat model.

Methods Wistar rat pups were divided into four groups as: group I, control group; group II, fucose-supplemented group; group III, lipopolysaccharide (LPS)-administered group, and group IV, LPS-exposed and fucose-supplemented group. Fucose was given 100 mg/kg i.p. every other day between PN5–17. LPS was administered on PN19 to establish endotoxin-induced cholestasis model. On PN21, animals were sacrificed to evaluate liver cell damage and apoptosis.

Results Fucose supplementation significantly improved the biochemical parameters that deteriorated in LPS-administered group, significantly increased the expression of bile salt export pump, reduced the number of apoptotic cell death, and greatly prevented LPS-induced cholestatic hepatic injury.

Conclusion Given our results, fucose may be useful in reducing hepatic injury and might possess clinical relevance for the preventive treatment of inflammation-induced cholestatic injury in newborns.
Interpretations of the Term “Watershed Line” Used as Reference for Volar Plating
Authors: Bergsma Minke , Doornberg Job N. , Hendrickx Laurent , Hayat Batur , Kerkhoffs Gino M.M.J. , Jhadav Bhavin , Jaarsma Ruurd L. , Bain Gregory I.
Published: August 2019

Objective The objective of this systematic review is to provide an overview of all interpretations of the definition of the watershed line used in literature.

Methods The Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines were followed for this review. A comprehensive search was performed for definitions of the watershed line given in literature. A total of 32 studies giving an explicit interpretation of the definition of the watershed line or anatomical reference for plate positioning in writing and/or imaging were included.

Results In 32 studies, we found eight different landmarks used to refer to the watershed line or correct plate positioning. Five studies used two different soft tissue landmarks. Six different bony landmarks were described in 24 studies. These could further be subdivided into three anatomical interpretations, described in seven studies, in which the term “watershed line” is explained as a distinguishable anatomical line, and two surgical interpretations, described in 15 studies, which are purely reflecting the optimal location of the volar plate. One interpretation of the watershed line described in two studies combined both anatomical and surgical landmarks.

Conclusion The (mis)interpretation of the definition of the term “watershed line” as described by Orbay is subject to the type of landmarks and purpose used: soft tissue or bony landmarks and an anatomical or a surgical purpose. A clear distinction can be made between interpretations using bony landmarks, as the true watershed line is defined and definitions using soft tissue landmarks, which might represent the reference points surgeons use in clinical practice.
Spinal Dural Arteriovenous Fistula-Induced Myelopathy: Rare and Commonly Missed but Treatable Nevertheless
Authors: Sharma Manish , Mathur Ankit
Published: August 2019

Objectives To highlight spinal dural arteriovenous fistula (dAVF) as a treatable cause of myelopathy that is often misdiagnosed. Clinical progression, hallmark radiological findings, and postoperative course of recovery are studied.

Patients and Methods Three patients with spinal dAVF were included in the study. Retrospective evaluation of the progression of disease and treatment received was done. Two of them were managed by surgical ligation of fistula, and the third patient was under observation because of lack of localizing symptoms.

Results Two of the three patients had previously been diagnosed with multiple sclerosis, and one of them had received steroids. The third case was easily diagnosed at an early stage as the center had become adequately sensitized about the radiologic findings. After surgical excision of the fistula, both operated cases recovered steadily but significantly, regained significant neurologic functions despite being operated at an advanced stage.

Conclusion Spinal dAVF is a rare entity. They have the potential to cause severe morbidity in the form of myelopathic changes in the cord and paraparesis in advanced stages. They can be misdiagnosed even after a magnetic resonance imaging evaluation as the appearance of dilated perimedullary veins and cord changes are not easy to interpret and require specific understanding of the radiologic changes that may occur. However, once diagnosis has been established, an early interruption of the fistula leads to a good clinical recovery.