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Parallel global rise in pit-latrine sanitation and groundwater-supply provision is of concern due to the frequent spatial proximity of these activities. Study of such an area in Malawi has allowed understanding of risks posed to groundwater from the recent implementation of a typical developing-country pit-latrine sanitation policy to be gained. This has assisted the development of a risk-assessment framework approach pragmatic to regulatory-practitioner management of this issue. The framework involves water-supply and pit-latrine mapping, monitoring of key groundwater contamination indicators and surveys of possible environmental site-condition factors and culminates in an integrated statistical evaluation of these datasets to identify the significant factors controlling risks posed. Our approach usefully establishes groundwater-quality baseline conditions of a potentially emergent issue for the study area. Such baselines are foundational to future trend discernment and contaminant natural attenuation verification critical to policies globally. Attribution of borehole contamination to pit-latrine loading should involve, as illustrated, the use of the range of contamination (chemical, microbiological) tracers available recognising none are ideal and several radial and capture-zone metrics that together may provide a weight of evidence. Elevated, albeit low-concentration, nitrate correlated with some radial metrics and was tentatively suggestive of emerging latrine influences. Longer term monitoring is, however, necessary to verify that the commonly observed latrine-borehole separation distances (29–58 m), alongside statutory guidelines, do not constitute significant risk. Borehole contamination was limited and correlation with various environmental-site condition factors also limited. This was potentially ascribed to effectiveness of attenuation to date, monitoring of an emergent problem yet to manifest, or else contamination from other sources. High borehole usage and protective wall absence correlated with observed microbiological contamination incidence, but could relate to increased human/animal activity close to these poorly protected boreholes. Additional to factors assessed, a groundwater-vulnerability factor is recommended that critically relies upon improved proactive securing of underpinning data during borehole/latrine installations. On-going concerns are wide ranging, including poorly constrained pit-latrine input, difficulties in assessing in-situ plume natural attenuation and possible disposal of used motor oils to latrines.

OBJECTIVE To determine whether a maxillary nerve block via a modified infraorbital approach, applied before rhinoscopy and nasal biopsy of dogs, would decrease procedural nociception, minimize cardiorespiratory anesthetic effects, and improve recovery quality. ANIMALS 8 healthy adult hound-type dogs PROCEDURES In a crossover study, dogs received 0.5% bupivacaine (0.1 mL/kg) or an equivalent volume of saline (0.9% NaCl) solution as a maxillary nerve block via a modified infraorbital approach. A 5-cm, 20-gauge over-the-needle catheter was placed retrograde within each infraorbital canal, and bupivacaine or saline solution was administered into each pterygopalatine region. Rhinoscopy and nasal biopsy were performed. Variables monitored included heart rate, systolic arterial blood pressure (SAP), mean arterial blood pressure (MAP), diastolic arterial blood pressure (DAP), plasma cortisol and norepinephrine concentrations, purposeful movement, and pain scores. After a 14-day washout period, the other treatment was administered on the contralateral side, and rhinoscopy and nasal biopsy were repeated. RESULTS SAP, MAP, and DAP were significantly higher for the saline solution treatment than for the bupivacaine treatment, irrespective of the time point. Plasma cortisol concentrations after saline solution treatment were significantly higher 5 minutes after nasal biopsy than at biopsy. Heart rate, norepinephrine concentration, purposeful movement, and pain score were not significantly different between treatments. CONCLUSIONS AND CLINICAL RELEVANCE Maxillary nerve block via a modified infraorbital approach prior to rhinoscopy and nasal biopsy reduced procedural nociception as determined on the basis of blood pressures and plasma cortisol concentrations during anesthesia. These findings warrant further evaluation in dogs with nasal disease.

The importance of proper skin wound healing becomes evident when our body's repair mechanisms fail, leading to either non-healing (chronic) wounds or excessive repair (fibrosis). Chronic wounds are a tremendous burden for patients and global healthcare systems and are on the rise due to their increasing incidence with age and diabetes. Curiously, these same risk factors also sign responsible for the development of hypertrophic scarring and organ fibrosis. Activated repair cells – myofibroblasts – are the main producers and organizers of extracellular matrix which is needed to restore tissue integrity after injury. Too many myofibroblasts working for too long cause tissue contractures that ultimately obstruct organ function. Insufficient myofibroblast activation and activities, in turn, prevents normal wound healing. This short review puts a spotlight on the myofibroblast for those who seek therapeutic targets in the context of dysregulated tissue repair. “Keep your myofibroblasts in balance” is the message.

ZusammenfassungDie sozio-demografische Entwicklung bedingt, dass sich immer häufiger ältere und alte Menschen mit Kopfschmerzen klinisch vorstellen. Diese Leitlinie soll ein erster Versuch sein, die Literatur zu Kopfschmerzen und Gesichtsschmerzen bei dieser Patientengruppe zusammenzufassen und spezifische Therapie-Empfehlungen zu geben. Dabei zeigt sich, dass die Alters-gruppe der über 65-Jährigen in fast allen Therapiestudien nicht berücksichtigt wird und die übrigen Studien meist diese Altersgruppe nicht betrachten. Wenig untersucht ist der Wandel der Symptome bei primären Kopfschmerzen in Abhängigkeit vom Alter. Generell treten bei Migräne vegetative Symptome seltener auf und Kopfschmerzen werden häufiger als drückend beschrieben. Der idiopathische schlafgebundene Kopfschmerz, die Arteriitis cranialis, die post-zosterische Neuralgie und die klassische Trigeminusneuralgie sind Erkrankungen, die ausschließlich bzw. vorwiegend im höheren Alter auftreten. Therapiestudien mit älteren Patienten sind nicht publiziert, generell gilt die Emp-fehlung, Leber- und Nierenfunktion zu beach-ten, niedrig dosiert zu beginnen und die Dosis langsam bis zur Wirksamkeit zu steigern.

Epidermolytic hyperkeratosis (bullous congenital ichthyosiform erythroderma), characterized by ichthyotic, rippled hyperkeratosis, erythroderma and skin blistering, is a rare autosomal dominant disease caused by mutations in keratin 1 or keratin 10 (K10) genes. A severe phenotype is caused by a missense mutation in a highly conserved arginine residue at position 156 (R156) in K10.

Most research has investigated the seat-to-head transmissibility during single-axis excitations. Associations between head accelerations and discomfort or effects on vision were reported. Possible differences between the seat-to-head transmissibility determined during different vibration magnitudes with a variable number of excitation axes have not been systematically examined. An experimental study was performed with 8 male subjects sitting on a rigid seat with hands on a support. They were exposed to random whole-body vibration (E1=0.45 ms(-2), E2=0.90 ms(-2), and E3=1.80 ms(-2)) to single- and three-axis vibration. All translational and rotational seat-to-head transmissibilities were calculated. The effects of the factors vibration magnitude and number of axes on the peak modulus and frequency of the seat-to-head transmissibilities were tested. In general the head motions follow constant pattern. These pattern of head motions comprise a combination of rotational and translational shares of transmissions, i.e. the curves show a dependence on the factors 'vibration magnitude' and 'number of vibration axes'. Mechanical properties of the soft tissue, relative motions of body parts, and muscle reactions were supposed to cause the nonlinearities of the head. Future research should consider effects of multi-axis vibration, if conclusions shall be drawn for the evaluation of possible health effects and model validations.

Laboratory tests were conducted using 13 male subjects seated on a cushioned commercial vehicle driver's seat. The hands gripped a mock-up steering wheel and the subjects were in contact with the lumbar region of the backrest. The accelerations and forces in the y -direction were measured during random lateral whole-body vibration with a frequency range between 0.25 and 30 Hz, vibration magnitudes 0.30, 0.98, and 1.92 m s −2 (unweighted root mean square (rms)). Based on these laboratory measurements, a linear multi-degree-of-freedom (mdof) model of the seated human body and cushioned seat in the lateral direction ( y -axis) was developed. Model parameters were identified from averaged measured apparent mass values (modulus and phase) for the three excitation magnitudes mentioned. A preferred model structure was selected from four 3-dof models analysed. The mean subject parameters were identified. In addition, identification of each subject's apparent mass model parameters was performed. The results are compared with previous studies. The developed model structure and the identified parameters can be used for further biodynamical research in seating dynamics.

The extent of intraspinal forces under whole-body vibration (WBV) depends on several factors like multiple excitations of different body parts, stature and posture. The effects of these forces are determined by individual tolerances. Hence, there is no direct and simple relationship between WBV and health risk of the lumbar spine. The current evaluation methods with respect to health cover only part of the WBV input to the human body and do not consider all associated factors. A set of 50 finite element (FE) models was developed, based on human anatomy and adapted to different typical postures of European drivers and their anthropometric parameters. Three-dimensional matrices of transfer functions simulate these models and permit a practicable routine computation by a Matlab program with graphical user interface to predict intraspinal compressive and shear forces caused by WBV-input in x-, y- and z-directions at the seat, backrest, feet and hands, measured on mobile machinery. The effects of posture and stature on predicted WBV-related internal loads are demonstrated, for example, of numerous WBV-measurements under field conditions. The predicted static and vibration-related peak-to-peak dynamic compressive forces are processed with a method of risk assessment based on cumulative fatigue failure and implemented as a Matlab-program. The resulting risk factors of the new assessment method are compared with existing evaluation procedures of ISO 2631-1 and ISO 2631-5. They reveal significant differences.

Modelling the response of the human body to occupational whole-body vibration provides the possibility of predicting the forces acting on the disc and/or endplates of lumbar vertebrae. Due to the complex structure of the human body, complex dynamic models based on human anatomy are required to adequately reflect the dynamic properties of the body. Based on experimental results the influence of posture and stature on the biodynamic behaviour of human subjects is described. To reflect the biodynamic response of different occupational groups of workers exposed to whole-body vibration, an existing model was adapted to five typical different postures and 10 representative statures registered of European drivers of heavy machines. The resulting 50 models were tested with white noise signals in three directions as input to the four interfaces buttock, back, feet, and hands. The results of the static and dynamic shares of the predicted spinal forces at six spinal levels show strong influences of the factors stature and posture. Calculated risk factors to estimate a probability of injuries reflect the influence of these factors. Based on these findings one frequency weighting curve for the assessment of vibration exposure is not sufficient to meet the variability of risks caused by different statures and postures. Relevance to Industry The results of the predicted spinal stress and possible health risk can be a basis to improve and to extend the range of measures of prevention, cab and seat design, or vibration isolation of seats. The measures should fit the wide range of spinal stress experienced by different percentile groups and different postures.

Horizontal whole-body vibration (WBV) can have an influence on health and comfort of drivers. Driver seats with additional suspensions in x - and/or y -axis should reduce the influence of vibration on the driver. No standards or test procedures are available for testing seats with horizontal suspensions. A standard test procedure for seats with horizontal suspensions could be developed from a test protocol used in a recent inter-laboratory study. To reduce the variability of the results obtained by different laboratories or repetitions, the test procedures should carefully consider methodological aspects with relevance to the results. Specifications of typical signals obtained in practice, or well-defined random time series as a basis for generation of test signals, with defined signs of acceleration would enable identical excitations in time domain and could reduce the variability of results caused by the non-linearity of the seat–human system. Nine healthy subjects volunteered for the study to test a seat with suspensions in three directions. They were selected with regard to three groups of body mass (52.4–54.6, 75.5–77.1, 98–100.7 kg). A random signal and two signals obtained in practice (tractor and truck) were selected for excitations in x - and y -directions by a six DOF electro-hydraulic simulator (hexapod). The errors between the desired and measured accelerations were calculated. The error depends on the signal, the direction and the subject. In the time domain, the absolute value of the error ranged from 1.8% to 42.4%. The SEAT value generally depends on the body mass, but in some cases the SEAT value of a lighter subject was lower than the SEAT value of a heavy one. This indicates that only one heavy and one light subject are not suited to calculate reliable parameters for an evaluation and comparison of seats. The non-symmetric displacements of the seat frame in x -direction indicate the non-linear behaviour of the seat–subject system. Relevance to industry Driver seats with suspensions in horizontal directions can reduce the influence of WBV on the health-risk of drivers. Laboratory test procedures are helpful for the evaluation and design of seats, if the results obtained by different laboratories are comparable. The paper describes methodological aspects that affect the test results and their variability.

Cutaneous wound healing is the physiological response to injury, and pathological healing continues to be one of the leading causes of morbidity and mortality. Patients suffering from diabetes, physical disablement, or vascular diseases are prone to exhibit poor healing and develop chronic wounds. Conversely, if tissue remodeling continues after successful healing, it develops into excessive connective tissue deformations that are visible as keloids and hypertrophic scars. Central effector cells in normal, insufficient, and excessive wound healing are extracellular matrix-producing and remodeling myofibroblasts. The local wound environment profoundly influences the healing success by controlling the activity of cells that are involved in the repair process. Hence, pharmacological as well as mechanical modulation of this environment bears significant potential to improve the outcome of wound healing. This chapter summarizes the factors leading to excessive healing and tissue contracture by myofibroblasts and reviews possible strategies on measures to improve the wound healing process. Emphasis will be placed on molecular targets and/or agents that have been shown to improve tissue repair in cell culture and animal models and that have entered into clinical trials.

Im Rahmen einer multizentrischen populationsbezogenen Fall-Kontroll-Studie zur Dosis-Wirkung-Beziehung zwischen beruflicher Wirbelsaulenbelastung durch Lastenhandhabung und belastungsintensiven Korperhaltungen und Bandscheibenerkrankungen der Lendenwirbelsaule (LWS) entsprechend BK Nr. 2108 BKV wurden auch Daten zur Ganzkor-pervibrationsbelastung erhoben. Die Studie umfasste 564 Probanden mit einem Bandscheibenvorfall der LWS, 351 Probanden mit einer fortgeschrittenen Chondrose der LWS und 901 Kontrollprobanden. Bei 65 Prolapspatienten, 39 Chondroseprobanden und 73 Kontrollen bestand eine berufliche Schwingungsexposition. Der Anteil von Frauen mit Schwingungsexposition war allerdings so klein, dass eine statistische Auswertung fur Frauen nicht sinnvoll erschien und die Auswertung ausschlieslich fur mannliche Probanden erfolgte. Fur die Auswertung der Schwingungsexposition kamen ein schichtbezogener Schwellenwert der Beurteilungsbeschleunigung von aw(8)=0,63 m/s2 und ein abgesenkter Schwellenwert von aw(8)=0,45 m/s2 zur Anwendung. Es wurden Beschleunigungen in z- und x- bzw. y-Richtung (VDI 2057, 2002 Bl.1) erhoben; fur die Auswertung wurden nur die Beschleunigungswerte in vertikaler Richtung zugrunde gelegt. Es zeigte sich kein Zusammenhang zwischen der lebenslangen kumulativen Belastung durch Ganzkorpervibration und einem Prolaps der LWS bei Mannern. Hingegen zeigte sich ein monoton ansteigender, jedoch statistisch nicht signifikanter Zusammenhang zwischen der Gesamtdosis fur Ganzkorperschwingung und einer Chondrose bei Mannern, und zwar bei beiden Schwellenwerten. Beim abgesenkten Tagesschwellenwert von aw(8)=0,45 m/s2 nimmt das fur Lastenhandhabung adjustierte Odds Ratio fur die hochste Gesamtdosiskategorie einen statistisch nicht signifikanten Wert von 1,7 (Konfidenzintervall CI95% 0,8–3,5) an; beim Tagesschwellenwert von aw(8)=0,45 m/s2 liegt die entsprechende Odds Ratio fur die hochste Gesamtdosis - kategorie bei 1,9 (CI95% 0,8–4,3). Werden entsprechend dem bisherigen Dosisrichtwert nach Dupuis (1994) nur Probanden mit einer kumulativen Schwingungsdosis von DVRI=1.450 (m/s2)2 der hochsten Belastungskategorie zugeordnet, so ergibt sich bei einem Schwellenwert fur die Tagesdosis aw(8) von 0,45 m/s2 eine statistisch signifikant erhohte Odds Ratio von 2,4 (CI95% 1,1–5,3). Die unterschiedlichen Ergebnisse fur Probanden der beiden Fallgruppen unterstutzen die Vermutung, dass Prolaps und Chondrose im Hinblick auf die Ganzkorpervibration als unterschiedliche Krankheitsbilder betrachtet werden mussen.

Die Pharmakotherapie muskuloskelettaler Schmerzen besitzt in den westlichen Industrielandern einen hohen Stellenwert. Die vorliegende Ubersicht konzentriert sich auf den Einsatz saurer (nicht-steroidale Antiphlogistika) und nicht-saurer [Paracetamol, selektive Zyklooxygenase- (COX-)2-Hemmer] antipyretischer Analgetika in der Therapie muskuloskelettaler Schmerzzustande. Schwerpunkt der Darstellung sind die unterschiedlichen kinetischen Eigenschaften und unerwunschten Wirkungen dieser Substanzen.

For modelling purposes and for evaluation of driver's seat performance in the vertical direction various mechano-mathematical models of the seated human body have been developed and standardized by the ISO. No such models exist hitherto for human body sitting in an upright position in a cushioned seat upper part, used in industrial environment, where the fore-and-aft vibrations play an important role. The interaction with the steering wheel has to be taken into consideration, as well as, the position of the human body upper torso with respect to the cushioned seat back as observed in real driving conditions. This complex problem has to be simplified first to arrive at manageable simpler models, which still reflect the main problem features. In a laboratory study accelerations and forces in x-direction were measured at the seat base during whole-body vibration in the fore-and-aft direction (random signal in the frequency range between 0.3 and 30 Hz, vibration magnitudes 0.28, 0.96, and 2.03 ms(-2) unweighted rms). Thirteen male subjects with body masses between 62.2 and 103.6 kg were chosen for the tests. They sat on a cushioned driver seat with hands on a support and backrest contact in the lumbar region only. Based on these laboratory measurements a linear model of the system-seated human body and cushioned seat in the fore-and-aft direction has been developed. The model accounts for the reaction from the steering wheel. Model parameters have been identified for each subject-measured apparent mass values (modulus and phase). The developed model structure and the averaged parameters can be used for further bio-dynamical research in this field.

Seats with horizontal suspensions can help to reduce detrimental effects of whole-body vibration (WBV) on health, comfort and performance. Two seats were used to examine the effect of body mass and WBV-magnitude on the transmission of WBV from the seat base to the cushion. Both seats have suspension in the x-direction while Seat 2 has suspension also in the y-direction. Twelve subjects with a body mass ranging from 59.0 to 97.3 kg volunteered for the study. A set of anthropometric characteristics was acquired. Three magnitudes of WBV were used with a truck-like signal (Seat 1, 0.3–0.59 m s−2 wd-weighted rms values at the seat base, x-direction) and a tractor-like signal (Seat 2, 0.55–1.09 m s−2 wd-weighted rms values at the seat base, x-direction, 0.52–1.07 m s−2 wd-weighted rms values, y-direction). The magnitude of WBV had a significant effect on the transmissibility characterized by SEAT-values. A significant influence of the body mass on SEAT-values was found for the y-direction only. Other anthropometric characteristics proved to be more important for the prediction of SEAT values by multiple regressions. There was no significant correlation of SEAT-values, x-direction, with the body mass. Other anthropometric characteristics enabled a satisfactory prediction of SEAT values also for x-direction in several cases. Tests with only two subjects of extreme body mass are not suited to obtain comparable and representative results required for a comparison of different seats with a suspension in the x-direction. The effect of the WBV-magnitude on the WBV-transmissibility should be considered with the design, testing and application of suspended seats.

Biodynamic responses to whole body vibrations are usually characterized in terms of transfer functions, such as impedance or apparent mass. Data measurements from subjects are averaged and analyzed with respect to certain attributes (anthropometrics, posture, excitation intensity, etc.). Averaging involves the risk of identifying unnatural vibration characteristics. The use of a modal description as an alternative method is presented and its contribution to biodynamic modelling is discussed. Modal description is not limited to just one biodynamic function: The method holds for all transfer functions. This is shown in terms of the apparent mass and the seat-to-head transfer function. The advantages of modal description are illustrated using apparent mass data of six male individuals of the same mass percentile. From experimental data, modal parameters such as natural frequencies, damping ratios and modal masses are identified which can easily be used to set up a mathematical model. Following the phenomenological approach, this model will provide the global vibration behavior relating to the input data. The modal description could be used for the development of hardware vibration dummies. With respect to software models such as finite element models, the validation process for these models can be supported by the modal approach. Modal parameters of computational models and of the experimental data can establish a basis for comparison.

Data of the impedance and/or the apparent mass of the sitting human body during the exposure to whole-body vibration in z -direction using rigid seats were standardized in the ISO 5982. These data are available as target functions for model developments. Models developed on this data basis should also apply to driver seats with a soft seat and backrest cushion, although the qualitative different contact conditions were neglected. Due to insufficient technical prerequisites, the determination of forces at the interface between subject and soft seat was impossible until very recently. Results of studies during static conditions showed clear differences in the pressure distributions between the rigid and the soft contact areas. In this experimental study pressure distributions on a seat cushion were measured during whole-body vibration in z -direction (random signal in the frequency range between 0.3 and 20 Hz, vibration magnitudes 0.25, 0.8, and 1.6 m s −2 unweighted root mean square measured at the seat base) with a sampling rate of 32 m s. The apparent masses were calculated by the forces derived from the pressure distributions and accelerations measured at one point of the seat cushion near the buttocks. The moduli of the apparent masses derived for the soft seat were clearly lower than those determined for a rigid seat. These apparent masses showed a similar dependence on the vibration magnitude as the apparent mass functions derived in the usual way for rigid seats. Factors that could explain differences between the apparent mass functions derived for the soft and rigid seat were discussed and evaluated. The data of this study indicate the possibility and necessity to consider the contact conditions at the interface when deriving target functions for the model development. Recommendations for technical improvements and further experimental studies with driver seats were derived.

In a prospective cohort study of 537 male professional drivers, the occurrence of sciatic pain showed stronger associations with measures of internal lumbar load expressed in terms of daily compressive dose, S(ed) (MPa), and risk factor, R (non-dimensional), according to ISO/WD 2631-5 (2013), than with measures of daily vibration exposure calculated as either 8-h energy-equivalent frequency-weighted acceleration (ms(-2) r.m.s.) or vibration dose value (ms(-1.75)) according to the EU Directive on mechanical vibration (2002). Herniated lumbar disc, previous lumbar trauma and physical work load were also powerful predictors of the occurrence of sciatic pain over time. Psychosocial work environment was poorly associated with sciatic pain. The boundary values of risk factor (R) for low and high probabilities of adverse health effects on the lumbar spine, as proposed by international standard ISO/WD 2631-5 (2013), tend to underestimate the health risk in professional drivers.In a prospective cohort study of professional drivers, measures of internal spinal load were better predictors of the occurrence of sciatic pain than the measures of daily vibration exposure established by the EU Directive (2002). Herniated lumbar disc, lumbar trauma and physical work load were also associated with sciatic pain.

WBV-exposures are often linked with forced postures as prolonged sitting, bent forward sitting, or sitting without a backrest. No quantitative data are available to describe the exposure–effect relationships for different conditions of seating, posture, and the biological variability of workers. Experiments and subsequent predictions of forces acting within the spine during WBV can help to improve the assessment of the health risk. An experimental study was performed with 39 male subjects sitting on a suspension seat with or with no backrest contact. They were exposed to random whole-body vibration with a weighted r.m.s. value of 0·6 m/s2 at a relaxed or a forward bending posture. A two-dimensional finite element model was used for the calculation of the internal spinal load. The model simulates the human response on a suspension driver seat. Individual exposure conditions were considered by including the transfer functions between the seat cushion and the seat base as well as between the backrest and the seat base for the calculation of the vibration input to the buttocks and to the back respectively. The average peak seat transmissibility was higher for the seat with the backrest, but the peak seat-to-head transmissibility was higher for the seat without the backrest for both postures. The peak transmissibilities between the accelerations at the seat base and the compressive forces at L5/S1 were highest for the seat without the backrest during the bending posture. Various biological effects can result from identical exposures combined with different backrest contact and postures. The backrest contact and posture conditions should not be neglected in the assessment of health risk caused by whole-body vibration.

The present study aimed to (1) employ the method for evaluation of vibration containing multiple shocks according to ISO/CD 2631-5:2014 (Model 1) and DIN SPEC 45697:2012 in a cohort of 537 professional drivers, (2) deliver the results for a re-analysis of epidemiological data obtained in the VIBRISKS study, (3) clarify the extent to which vibration acceleration and individual variables influence risk values, such as the daily compressive dose S(ed) and the risk factor R, and (4) compare the results with in vivo measurements and those obtained in previous studies with similar models. The risk factor R was influenced by the acceleration, lifetime exposure duration, sitting posture, age at the start of exposure and body mass/body mass index in order of decreasing effect. Age and annual and daily exposure duration had only a marginal effect. The daily compressive dose S(ed) and the risk factor R showed weak linear association with the daily vibration exposure A(8) and the vibration dose value VDV. The study revealed high shear forces in the lumbar spine.In a re-analysis of an epidemiological study of professional drivers, a software tool available with standards DIN SPEC 45697:2012 and ISO/CD 2631–5:2014 Model 1 was used to calculate the risk to the lumbar spine in terms of daily compressive dose S(ed) and risk factor R. The tool was found to be suitable for risk assessment in a large cohort.

Objective. To predict forces acting on the spine during whole-body vibration for a variety of boundary conditions – body mass, height and posture. Design. Representative anthropometric data and models for an upright, relaxed and bent forward sitting posture were used to derive model families with 30 variants of a finite-element model. Background. A given exposure to whole-body vibration can cause a variable health risk depending on the concomitant conditions. The latter could contribute to the considerable uncertainty of the current evaluation of whole-body vibration. Methods. Plane symmetric linear finite-element models were used for the prediction of static and dynamic compression and shear forces acting on the lumbar discs during whole-body vibration. Transfer functions from seat acceleration to forces were determined. Results. A bent forward posture augments essentially the compressive and shear stress, predicted for erect and relaxed sitting postures. The normal variation of body mass and height causes a considerable variation of static internal shear stress, but a minor variation of compressive pressure. The dynamic internal stress varies nearly proportionally to the body mass. The transfer functions from seat acceleration to compressive force depend significantly on the posture. Conclusions. The variability of the spinal loads for a given whole-body vibration and associated with a normal range of several biological factors suggests a ratio between the minimum and maximum internal loads of about 1:2. Relevance Finite-element models can be used to compare the health risk arising from different whole-body vibration exposures and individual conditions. These results help to prevent work-related disorders of the lumbar spine.

Objective . To elaborate methods for an elimination of artefacts and the analysis of the relationship between random whole-body vibration and electromyographic responses of back muscles. Design . A procedure involving wavelets and digital filtering has been used for the removal of artefacts from the electromyogram during whole-body vibration. Background . Back muscle forces contribute essentially to the whole-body vibration-induced spinal load. The electromyogram can help to estimate these forces during whole-body vibration. Methods . 38 subjects were exposed to identical random low-frequency whole-body vibration. Artefacts caused by the electrocardiogram in the electromyogram were identified by appropriate wavelets and eliminated in the time-domain. After averaging the individual high-pass filtered and rectified undistorted electromyograms across subjects, the transfer function from seat acceleration to the average electromyogram was determined and used for the prediction of the electromyogram. Results . A sufficient procedure involving wavelets and digital filtering has been elaborated for the removal of artefacts from the electromyogram of back muscles during whole-body vibration. A systematic relationship between random vibration and back muscle-response was obtained and described. The transfer function suggests two different reflex-mechanisms – one elicited below, the other above 4 Hz. Conclusions . The approach of analysing and predicting the muscle-response to random vibration by using the transfer function seems to be promising and could be a valuable tool for the future calculation of muscle forces as an input to active models. Relevance The knowledge of the extent and timing of the back muscle-response to random whole-body vibration is relevant for an improved evaluation of whole-body vibration with respect to health.

The alcoholysis of acetyl chloride, propionyl chloride and butyryl chloride with some alcohols in acetone and toluene has been investigated by means of calorimetric measurements. Furthermore a comparison with benzoyl chloride has been made. In the case of i-propanol in acetone, a smaller rate constant has been found for the alcoholysis of propionyl chloride than for butyryl chloride. In contrast to this, almost equal rate constants have been determined for the reactions of these acyl chlorides with n-propanol and ethanol. In toluene, the rate constants for the reaction of acetyl chloride with all considered alcohols has the highest values under similar conditions but then decrease from acetyl chloride to butyryl chloride. The observed differences and the changes of rate constants are discussed and compared with literature data.

The alcoholysis of acetyl chloride under various reaction conditions has been investigated by isoperibolic calorimetry and HPLC-analysis. Non-linear kinetic evaluation has been realized by the program TA-kin 3.3 on the basis of temperature and concentration data. Depending on the excess of alcohol, different partial reaction orders are found. The reaction rate also depends on the basicity of the solvent. This could be caused by H-bonding with the alcohol increasing the activation energy. It was possible to distinguish between the kinetic parameters of the ethanolysis and the i -propanolysis of acetyl chloride in the evaluation of the alcoholysis of acetyl chloride by alcoholic mixtures at stoichiometric concentrations of the reagents. A partial order of n =0.5 for the alcohol, as determined in the evaluation of the single alcoholysis under these conditions, has been confirmed. The results show that heat accumulations are an important feature for the kinetic evaluation of reactions under the concentration conditions described.

The ethanolysis of acetyl chloride has been compared to the methanolysis and the hydrolysis, as well as to the reaction with n -propanol, n -butanol and n -pentanol in acetone and in toluene, to reveal chain-length effects. Pentanol, heptanol and nonanol have been included as well in the investigation, but at lower concentrations. Structural influences on the alcoholysis of acetyl chloride have been studied with the isomeric C 3 and C 4 -alcohols in acetone and in toluene. Furthermore, alcoholysis of acetyl chloride with some C 7 -alcohols and the reaction of benzoyl chloride with different types of alcohols have been investigated.

Die therapeutischen und unerwunschten Effekte nichtsteroidaler Antiphlogistika (NSAIDs) beruhen auf einer Hemmung des Enzyms Zyklooxygenase (COX), das den ersten Schritt der Prostanoidbiosynthese katalysiert. Mit der Entdeckung einer induzierbaren COX-Isoform zu Beginn der 90er Jahre zeigte sich, dass 2 Isoformen des Enzyms existieren. COX-1 wird als “housekeeping”-Enzym in den meisten Geweben konstitutiv exprimiert. COX-2 wird durch verschiedene proinflammatorische Meditoren (Endotoxin, Zytokine, Wachstumsfaktoren) hochreguliert. Wahrend eine Reihe unerwunschter NSAID-Effekte (gastrointestinale Ulzerationen und Blutungen, Plattchendysfunktionen) auf einer COX-1-Hemmung basieren, wird eine Unterdruckung COX-2-abhangiger Prostaglandine als Basis der analgetischen, antipyretischen und antiinflammatorischen Wirkung von NSAIDs diskutiert. Die Perspektive, erwunschte therapeutische Effekte von unerwunschten Wirkungen zu trennen, erwies sich als Basis der Entwicklung spezifischer COX-2-Inhibitoren als neue Klasse antiinflammatorischer und analgetischer Substanzen mit verbesserter gastrointestinaler Vertraglichkeit. Das einfache Konzept einer ausschlieslich proinflammatorischen induzierbaren COX-2-Isoform lasst sich nach Untersuchungen der letzten Jahre jedoch nicht mehr halten. So konnte gezeigt werden, dass die COX-2-Isoform in verschiedenen Organen (z. B. Ovarien, Uterus, Gehirn, Ruckenmark, Niere und Knochen) konstitutiv exprimiert wird und dort physiologische Prozesse mediiert. In der vorliegenden Ubersicht werden das Konzept und der molekulare Mechanismus einer spezifischen COX-2-Hemmung sowie Indikationen, Pharmakokinetik und unerwunschte Wirkungen der kurzlich zugelassenen spezifischen COX-2-Inhibitoren Celecoxib und Rofecoxib dargestellt. Des Weiteren werden neue Befunde zu physiologischen Funktionen des COX-2-Enzyms diskutiert.

To examine the response of back muscles to whole-body vibration (WBV) consisting of a sinusoidal “background” (4 Hz, r.m.s. acceleration 0.52 ms−2) and 10 interspersed periods with peak-to-peak amplitudes (“transients”) that varied in three steps (3.5, 7.2, and 11.1 ms−2), six surface electromyograms (EMGs) were obtained from different back muscles of 8 subjects at 3 different sitting postures (relaxed = R, bent forward = B and straight erect = E). The rectified undistorted EMGs and the force at the interface vibrator/subject of all subjects were averaged. The myoelectric activity at R was minimal, B and E were accompanied by a high basic EMG-activity and pronounced responses to the transients. The timing of the maximum EMG-responses varied. A nonlinear increase of the internal load was predicted with rising amplitudes of transients. The threshold for this prominent unfavourable biological effect might be located between 3.5 and 5 ms−2.

The operators of earth moving machinery are often exposed to a low frequency vibration environment caused by the movement of vehicles over uneven ground and the task carried out. The seat constitutes the least state of suspension before the driver. The efficiency of attenuation under consideration of the best design practice today is the basis for the revision of ISO 7096 for the testing seats for earth moving machinery. This standard requires the participation of two subjects with different body masses (52–55 kg; 98–103 kg). The aim of the study was to investigate (1) the extent and the influence of individual variability and posture change on the result of seat tests, and (2) the possibility of deducing representative results for the user population. 37 male subjects took part in the experimental investigations. They were exposed in three postures for 67 s to three acceleration signals in a vertical direction corresponding to the spectral classes (EM2, EM5, EM6) in ISO/DIS 7096 on two commercial suspension seats. The vertical accelerations were measured at the seat basis and at the interface between seat cushion and subject. The results of the analysis of variance show a significant influence of exposure, type of seat, and interactions exposure-by-posture, exposure-by-type of seat, and posture-by type of seat on the SEAT factor. Simple and multiple regression analyses were applied in order to test the predictability of the seat factor (SEAT) by anthropometric variables. The conclusions were drawn that the seat testing could be improved by (1) selecting subjects according to the 5th and 95th percentile masses of the population of vehicle or machinery users for which the seat is intended (ISO 10326), instead of fixed masses (ISO 7096), (2) considering other anthropometric parameters for the selection like the body height and body mass supported by the seat, and (3) the inclusion of several subjects near the 50th percentile in order to assess the variability of the SEAT factor.

The guidance on the effects of vibration on health in standards for whole-body vibration (WBV) does not provide quantitative relationships between WBV and health risk. The paper aims at the elucidation of exposure–response relationships. An analysis of published data on the static and dynamic strength of vertebrae and bone, loaded with various frequencies under different conditions, provided the basis for a theoretical approach to evaluate repetitive loads on the lumbar spine (“internal loads”). The approach enabled the calculation of “equivalent”—with respect to cumulative fatigue failure—combinations of amplitudes and numbers of internal cyclic stress. In order to discover the relation between external peak accelerations at the seat and internal peak loads, biodynamic data of experiments (36 subjects, three somatotypes, two different postures—relaxed and bent forward; random WBV,aw, r.m.s. 1·4 ms−2, containing high transients) were used as input to a biomechanical model. Internal pressure changes were calculated using individual areas of vertebral endplates. The assessment of WBV was based on the quantitative relations between peak accelerations at the seat and pressures predicted for the disk L5/S1. For identical exposures clearly higher rates of pressure rise in the bent forward compared to the relaxed posture were predicted. The risk assessment for internal forces considered the combined internal static and dynamic loads, in relation to the predicted individual strength, and Miner's hypothesis. For exposure durations between 1 min and 8 h, energy equivalent vibration magnitudes (formula B.1, ISO 2631-1, 1997) and equivalent vibration magnitudes according to formula B.2 (time dependence over-energetic) were compared with equivalent combinations of upward peak accelerations and exposure durations according to predicted cumulative fatigue failures of lumbar vertebrae. Formula B.1 seems to underestimate the health risk caused by high magnitudes, formula B.2 is recommended for the evaluation of such conditions.

Investigations in chemical safety are necessary in case that the reaction course depends on changes of the reaction conditions sensitively. To break off a conversion in a hazardous situation, the precision calorimeter ACTRON 5 is equipped with two safety pumps. They empty and rinse the reactor with cold solvent. The pumps will be activated automatically. For testing the calorimeter the complex reaction of chloronitrobenzene with alkalined alcohol was used and break off at predefined conditions. The possibility of the kinetic estimation of these break-off files is shown.

Polyethers, which are produced by alcoholysis of oxiranes, are often used as solvents in chemical plants. The spectra of the products can be influenced by the choice of the catalyst (acid or base). The results of the base-catalyzed ethanolysis of 1,2-epoxybutane are displayed. The reaction was investigated calorimetrically by varying the molar ratio between ethanol and 1,2-epoxybutane, the starting temperature and the concentration of the catalyst sodium hydroxide. Additionally, the influence of the used alcohol will be shown in one example. To determine the activation parameters, the experiments were evaluated by the nonlinear software package TA-kin v3.3.

Acetylation of different hexanediols as a complex reaction has been investigated by calorimetry. The calorimetric curves demonstrate that the reaction rate depends on the molecular structure. In case of 1,6- and 2,5-hexanediols, the activation parameters have been obtained by nonlinear evaluation procedures with the program TA-kin v3.3. The kinetic results show, that the formation of the diester is characterized by higher activation energies than that of the monoester.

A computer program was developed for kinetic evaluations of calorimetric experiments to predict the further reaction run under adiabatic conditions. Kinetic modeling is based on elementary reaction steps whose rate laws form a set of differential equations. For the continuous parameter optimization time-temperature data and their derivatives are used. A special calorimeter of the ACTRON series with safety equipment was applied to investigate the kinetics of chemical reactions and to test kinetic on-line evaluations. In the paper, examples for the reaction of n-propanol with o-chlornitrobenzene and for the alcoholysis of phenyl isocyanate are given.

Different ACTRON calorimeters were used to investigate the alcoholysis of phenyl isocyanate and acetyl chloride, and the reaction of o-chloronitrobenzene with alkaline alcohol. An example for a scenario to break off a reaction in a hazardous situation is given. At least it will be shown, that it is possible to evaluate an interrupted reaction to get the kinetic activation parameters.

Safety production in chemical plants is a high-priority task, especially as concerns reactions which can change mechanism suddenly under defined conditions, e.g. from a simple well-defined to an undesired autocatalytic reaction. An example of this kind, the reaction of chloronitrobenzene with alkaline alcohol, was investigated with the new adiabatic precision calorimeter ACTRON 5, designed with a safety concept. It is shown that the reaction can be interrupted safely under predicted conditions.

Accelerations, a , in z - and x -directions were measured on the skin over spinous processes L 3 and L 4 in three subjects during sinusoidal whole-body vibration (WBV) at 4·5 and 8 Hz and 1·5 and 3·0 ms −2 r.m.s. A method for the prediction of bone accelerations was applied using measurements on the skin. Relative accelerations were calculated by subtracting a L4 from a L3 . The phase relations between relative accelerations in the z -direction indicating compression and the absolute maximum a z of L 4 exhibited marked between-subject variability. One subject was selected for a detailed analysis in the time domain of head, shoulder and upper trunk accelerations, and for comparison with an invasive study. Bidimensional acceleration data confirmed the suggestion that relative motions in the z -direction are combined with angular motions. The results indicate complex internal loads with coupled bending, compression and shear forces.

Because there is risk of autocatalytic reduction, the conversion of chloronitrobenzene with alkaline alcohol is important in safety management. The influence of several parameters on the reaction will be described. The experiments were realized in a non commercial calorimeter, equipped with for the precision calorimeter ACTRON developed hard- and software. For the non-linear kinetic evaluation of the experiments the program TA-kin was used.

Chloronitrobenzene can react with alkaline alcohol in two directions depending on the chemical conditions: substitution and reduction. The hazardous potential of the latter is caused by an autocatalysis. We investigated calorimetrically the reaction conditions under which the harmless substitution turns into reduction. The influence of the oxygen content of the atmosphere on the overturn to reduction demonstrated that it will be shifted back with increasing oxygen.

During pyrolysis of chlorine-containing materials, it is necessary to trap the HCl formed to avoid re-formation of organochlorine compounds and to prevent corrosion in the plant. This is usually done using limestone, but the resulting mass streams cause many difficulties. These mass streams, which increase with the amount of organochlorine compounds, were the main reason for the shut down of the technical pilot plant in Ebenhausen. When ammonia is added to the fluidizing gas during pyrolysis NH 3 ·HCl is formed, passes the cyclone at temperature above 450°C and is collected behind the cyclone. In contrast to dechlorination with limestone, this procedure causes only small mass streams. The chlorine content remaining is less than 1000 p.p.m. To reduce it to less than 10 p.p.m. sodium is added to the product gases at temperatures of about 500°C behind the cyclone. Educts containing small amounts of PCB, and polychlorinated dioxines and furanes were also pyrolyzed. The economy of pyrolysis depends on the costs of plastics disposal and of plastics incineration, compared with the cost of pyrolysis, which is believed to be 250 DM/t.

This study was performed in order to clarify, (1) if trunk muscles react immediately to a transient whole-body vibration (WBV), (2) to which extent the timing of EMG depends on the direction of transient WBV and/or on the muscle group, and (3) to which degree after-effects of transient WBVs have to be considered. Five healthy males were exposed to transient displacements (nearly sinusoidal or half-sinusoidal waveforms with peak accelerations of about ±2.7 ms −2 ). Four EMGs (m. erector spinae at 3 levels and m. trapezius) were averaged and normalized. The alternating activation-inactivation of the EMG-responses nearly exhibited a mirror symmetry when the direction of displacements changed. Responses occurred earlier at the shoulder than at the lumbar level. An increased health risk was predicted for (1) the initial phase of a sudden upward displacement without motion in the history preceding the transient WBV and (2) a downward displacement with a dominating frequency near 6–8 Hz. The immediate muscular reactions suggest the necessity to include muscle forces in calculations of the spinal load under transient WBV, except for the first 50 to 100 ms of an event without motion in its preceding time history. The direction and preceding history of a transient WBV should be considered in future evaluation procedures as a characteristic of WBV-exposure.