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Digitalization and BIM in geotechnics – opportunities and challenges According to the specifications of the BMVI (Federal Ministry of Transport and Digital Infrastructure), BIM‐supported (Building Information Modeling) project management is required for transport and infrastructure projects from 2025 at the latest. So far, however, the requirements of the "Stufenplan" (BMVI) have been based exclusively on the areas of structural engineering and infrastructure works. The field of geotechnics and 3D ground modeling is still in its infancy, although digitization has already opened up many possibilities in geotechnics. These include, for example, web‐based GIS applications for ground investigations. All project participants can use mobile devices to access project‐relevant information at any time, which is important for planning and monitoring investigation work. After completion of the investigation program, the results are to be integrated into a 3D subsoil model. There is a large number of software programs on the market, and two selected programs with their advantages and disadvantages are listed in the following article. Finally, the challenges but also the possibilities of BIM based planning are presented and the aspects from the point of view of practical application are highlighted. [ABSTRACT FROM AUTHOR]

SARS‐CoV‐2 may not only manifest as pneumonia (COVID‐19) but also in other organs, including the brain (neuro‐COVID). One of the cerebral complications of SARS‐CoV‐2 is ischemic stroke. Transitory ischemic attack (TIA) in a SARS‐CoV‐2 positive has not been reported. A 78‐year‐old poly‐morbid male (diabetes, hypertension, and coronary heart disease), admitted for COVID‐19, developed atrial flutter on hospital day (hd) 2. Anticoagulation with enoxaparin was started. On hd5, he experienced a TIA despite sufficient anticoagulation. The patient expired on hd28 due to multi‐organ failure from sepsis due to superinfection with staphylococcus aureus. Infection with SARS‐CoV‐2 may be complicated by atrial flutter. Atrial flutter may be complicated by TIA despite sufficient anticoagulation, suggesting that standard anticoagulation may be insufficient to meet SARS‐CoV‐2‐associated hypercoagulability syndrome. Forced anticoagulation and adequate antibiosis in poly‐morbid SARS‐CoV‐2‐infected patients with hypercoagulability and cytokine storm are warranted. [ABSTRACT FROM AUTHOR]

Nowadays, liquid rocket engines use closed-loop control at most near-steady operating conditions. The control of the transient phases is traditionally performed in open loop due to highly nonlinear system dynamics. This situation is unsatisfactory, in particular for reusable engines. The open-loop control system cannot provide optimal engine performance due to external disturbances or the degeneration of engine components over time. In this article, we study a deep reinforcement learning approach for optimal control of a generic gas-generator engine's continuous startup phase. It is shown that the learned policy can reach different steady-state operating points and convincingly adapt to changing system parameters. Compared to carefully tuned open-loop sequences and proportional-integral-derivative (PID) controllers, the deep reinforcement learning controller achieves the highest performance. In addition, it requires only minimal computational effort to calculate the control action, which is a big advantage over approaches that require online optimization, such as model predictive control. [ABSTRACT FROM AUTHOR]

The global microplastic pollution issue, as a result of the indispensable usage of microplastics in building materials, packaged food, medical products and consumer goods, poses significant health problems for the population. These small particles can penetrate intact cell barriers in the intestines and alveoli, thereby entering the bloodstream. The aim of this pilot study was to investigate the effects of reduced plastic consumption on blood pressure. Eight adult and healthy participants abstained from consuming commercially produced bottled beverages and restricted their primary fluid intake to tap water. Blood pressure was measured on both sides before, after 14 days and after 28 to 30 days of this partial plastic diet. Women exhibit a significant change in systolic blood pressure on the right arm after 2 and 4 weeks, while the left arm demonstrates no significant changes in blood pressure. On the contrary, in men, systolic blood pressure values on both arms show no significant alterations, attributable to the high variability across the three participants. Moreover, no significant differences in systolic blood pressure were observed when analysing the entire cohort. Significant findings are evident only at the two-week mark for diastolic blood pressure for all participants in both arms. When considering diastolic blood pressure separately for women and men, men again show no significant changes in blood pressure on either arm. However, women exhibit a significant decrease in diastolic blood pressure on the left arm after 2 weeks and a statistically significant decline in diastolic blood pressure on the right arm after both 2 and 4 weeks. The results of the study suggest, for the first time, that a reduction in plastic use could potentially lower blood pressure, probably due to the reduced volume of plastic particles in the bloodstream. To confirm this hypothesis, a larger sample of male and female participants must be examined, ideally with the monitoring of plastic concentration in the blood. [ABSTRACT FROM AUTHOR]

We present a data-driven method for the early detection of thermoacoustic instabilities. Recurrence quantification analysis is used to calculate characteristic combustion features from short-length time series of dynamic pressure sensor data. Features like recurrence rate are used to train support vector machines to detect the onset of instability a few hundred milliseconds in advance. The performance of the proposed method is investigated on experimental data from a representative LOX/H 2 research thrust chamber. In most cases, the method is able to timely predict two types of thermoacoustic instabilities on test data not used for training. The results are compared with state-of-the-art early warning indicators. [ABSTRACT FROM AUTHOR]

In the course of the preliminary planning of the new Gelnhausen–Fulda railway line which is part of the railway project Hanau–Würzburg/Fulda, two route options with tunnels, bridges, cuts and embankments are to be investigated and assessed as efficiently as possible with regard to potential geotechnical risk areas. Due to the geological and hydrogeological conditions within the north‐eastern Hessian Buntsandsteingebirge, several groundwater levels, landslides in tunnel portal areas and karstification structures are to be expected on the two route options, each of which is approx. 45 km long. In order to obtain detailed and, above all, large‐scale knowledge of geotechnical hazards of each route = in the preliminary stage of the exploration programme, geophysical surface investigations are a cost‐ and time‐optimized exploration method in addition to standard drilling. These findings as well as existing subsurface information are combined by means of BIM, so that risk areas can be identified at an early stage of the project and taken into account when selecting the most affordable route. [ABSTRACT FROM AUTHOR]

The Filstal Bridge at the new railway line Wendlingen–Ulm – challenges for the geotechnical planning of a semi‐integral construction The Filstal Bridge is part of the high‐speed railway line of the mega project Stuttgart 21, project section „Albaufstieg", and is planned as semi‐integral construction. The pillars are connected monolithically and force‐locking with the superstructure. The design planning scheduled surface foundations at the abutments and combined pile‐raft foundations at the pillars. The ground is built by jurassic limestone with partial karstification. On the basis of a consequent designation of reserves for the supporting structure by applying sophisticated numerical modelling in combination with pile load tests, the foundation was optimized and 50 % of the total pile meters could be save compared to the original design planning. In terms of th e construction work at the abutment, complex and highly disintegrated rock mass was observed. Therefore, multiple remuneration measures were planned and carried out at the construction site. [ABSTRACT FROM AUTHOR]

This article argues for the consideration of sociocultural parameters in analyzing Eduard Hanslick's aesthetics, scholarly writings, and academic activities. Scholarship often treats Hanslick's acontextual perspective as an absolute position, irrespective of Hanslick's contexts or of the historical conditions that have led to Hanslick's formalist viewpoint. This text thus explores Hanslick's nation-neutral attitude towards music that derives from the multi-ethnic makeup of Austrian society, outlines how Habsburg science policies countered nationalist sentiments by fostering positivist methods, and shows how Hanslick intentionally corresponds to these social and political criteria. [ABSTRACT FROM AUTHOR]

Performance prediction is one of the crucial issues for estimating excavation costs and construction time of tunnel projects. In mechanized tunneling, TBM performance highly depends on achieved penetration rate and cutter wear. The aim of the research group ABROCK and the topic of this paper is the improvement of penetration prediction by performing on-site penetration tests. Therefore estimated parameters by two existing prediction models (Gehring model, Colorado School of Mines model) are compared with the results of penetration tests at Austrians large infrastructure project of the OeBB Koralm tunnel construction lot KAT2. Penetration tests are a common tool to determine the performance of a TBM in certain geological environments. During a test, the TBM is operated under defined conditions that allow the comparison of different tunnel projects and machine types in analogous geological conditions. Results show that only for a narrow scope, considered prediction models reveal appropriate fitting. Once the rock mass is fractured or the stress level within the rock mass changes, existing models are not applicable. This fact emphasizes the need of an update for penetration prediction models by implementing a correction factor for discontinuities and the stress state in a rock mass. This may result in a new prognosis model called Alpine model. Die Leistungsprognose ist einer der wichtigsten Aspekte für die Kalkulation von Baukosten und Bauzeiten bei Tunnelprojekten. Die Leistung einer TBM wird von der erreichten Penetration sowie dem auftretenden Werkzeugverschleiß bestimmt. Ziel der Forschungsgruppe ABROCK sowie Schwerpunkt dieses Beitrags ist es, existierende Penetrationsprognosemodelle mithilfe von Penetrationsversuchen auf Tunnelbaustellen zu verbessern. In diesem Beitrag werden die prognostizierten Penetrationswerte von zwei gebräuchlichen Modellen (Gehring Model, Colorado School of Mines Model) mit den Ergebnissen der Penetrationsversuche am großen österreichischen Infrastrukturprojekt der ÖBB-Infrastruktur AG, dem Koralmtunnel Baulos KAT2, verglichen. Der Penetrationsversuch ist eine häufig angewandte Methode, um die Leistung einer TBM in einem gewissen geologischen Umfeld zu bestimmen. Hierbei wird die Maschine unter definierten Bedingungen gefahren, wodurch ein Vergleich unterschiedlicher Tunnelprojekte sowie Maschinentypen bei entsprechenden geologischen Verhältnissen ermöglicht wird. Die Ergebnisse zeigen, dass die untersuchten Prognosemodelle nur für einen sehr engen Anwendungsbereich zuverlässige Werte liefern. Sobald das Gebirge Trennflächen oder einen veränderten Spannungszustand aufweist, sind beide Ansätze nicht mehr brauchbar. Diese Tatsache zeigt deutlich, dass die existierenden Modelle adaptiert werden müssen, indem Korrekturfaktoren für das Trennflächengefüge sowie den Spannungszustand im Gebirge implementiert werden. Dies soll in einem neuen Prognosemodell, dem sogenannten Alpine-Modell resultieren. [ABSTRACT FROM AUTHOR]

Five universities from Austria, Germany and Switzerland, working intensively together with partners from the industry, client organisations, companies, consultants and TBM manufacturers, have combined to develop a new prognosis model for TBM advance rate and disc wear (the 'ALPINE MODEL'). This article presents some new results from the project. Fundamentally, the new model is to be a development of the model from Gehring, which calculates the penetration from the ratio of disc load to uniaxial compression strength. Since this equation was derived from data collected from a limited number of projects in the 1980s, it is of great importance to widen the data base and to establish a standardised process for this purpose. For on-site tests, the 'Start-stop-penetration test' is considered the most efficient and suitable method. This test can be carried out with the TBM in the course of tunnelling and thus results in little delay. In addition to the recording of TBM data during the penetration test, detailed geological documentation of the face and the tunnel sides has to be undertaken, accompanied by geomechanical laboratory tests. A large number of such penetration tests have now been carried out on various tunnel projects in order to validate and improve the basic formula. Some of the first results are described in this article. Further themes include the rock mechanical parameters to be used, the influence of the primary stress conditions at the face and the abrasiveness of the rock. Fünf Universitäten aus Österreich, Deutschland und der Schweiz, die intensive mit Partnern aus der Wirtschaft, Bauherren, Firmen, Ingenieurbüros und TBM Herstellern zusammenarbeiten, entwickeln gemeinsam ein neues Prognosemodell für die TBM Vortriebsleistung und den Rollenmeißel-Verschleiß (das 'ALPINE MODEL'). In diesem Artikel werden einige neue Ergebnisse dazu vorgestellt. Grundsätzlich soll das neue Modell wie das zugrunde liegende Modell von Gehring aufgebaut sein, dessen Basis aus der Berechnung der Penetration durch das Verhältnis von Diskenlast und Einaxialer Druckfestigkeit besteht. Nachdem diese Beziehung aus Daten abgeleitet ist, die in 1980er-Jahren aus einer beschränkten Anzahl von Projekten gesammelt wurden, ist es von unmittelbarer Bedeutung, diese Datenbasis auszuweiten und dafür ein Standardverfahren zu etablieren. Für Vor-Ort-Versuche wird der sog. 'Start-Stop-Penetrationsversuch' als effizienteste und geeignetste Methode angesehen. Dieser Versuch kann mit der TBM während des Vortriebs durchgeführt werden und führt daher nur zu sehr geringen Vortriebsverzögerungen. Neben der Aufzeichnung der TBM Vortriebsdaten während des Penetrationsversuchs muss eine detaillierte geologische Dokumentation der Ortsbrust und der Laibung sowie felsmechanische Laboruntersuchungen der Gesteine vorgenommen werden. Eine große Anzahl von solchen Penetrationsversuchen wurde bei unterschiedlichen Tunnelprojekten durchgeführt, um die Basis-Formel zu validieren bzw. zu verbessern. Einige erste Ergebnisse werden in diesem Artikel vorgestellt. Andere Themen umfassen die heranzuziehenden felsmechanischen Kennwerte, den Einfluss der Primärspannungsbedingungen an der Ortsbrust und die Abrasivität des Gesteins. [ABSTRACT FROM AUTHOR]

At DLR neural networks, as potential future controller for rocket engines, are studied. A neural network-based chamber pressure controller for a simplified cold gas thruster is presented and analyzed in simulation and experiment. The goal of the controller is twofold: It can track a trajectory with different changes of setpoints and it allows to set and control a wide variety of steady state chamber pressures. The neural network gets feeding line pressure measurement data as input and calculates valve positions as output values. The training phase of the controller is done with a reinforcement learning algorithm in an EcosimPro/ESPSS simulation, that is validated with data from the corresponding experimental set up. To increase the robustness and to allow a transfer from the simulation directly to the test facility domain randomization is applied. The controller is evaluated in simulations and experiment. It was found that – in the range of physically possible operation points – the controller achieves a constantly high reward which corresponds to a low error and a good control performance. In the simulation the controller was able to adjust all required set points with a steady state error of less than 0.1 bar while retaining a small overshoot and an optimal settling time. It is found that the controller is also able to regulate all desired set points in the real experiment. A reference trajectory with different steps, linear and sinus changes in target pressure is tested in simulation and experiment. The controller was in both cases able to successfully follow the given trajectory. • Simulation trained, reinforcement learning based thrust chamber pressure controller. • Experimental and simulative evaluation of control policy. • Steady state error less than 0.1 bar. • Controller follows trajectories successfully. [ABSTRACT FROM AUTHOR]

Identifying the optimal design of a new launch vehicle is most important because design decisions made in the early development phase limit the later performance of the vehicles and determine the associated costs. Reusing the first stage via retropropulsive landing increases the complexity even more. Therefore, an optimization framework for partially reusable launch vehicles is developed, which enables multidisciplinary design studies. The framework contains suitable mass estimates of all essential subsystems and a routine to calculate the needed propellant for the ascent and landing maneuvers. For design optimization, the framework can be coupled with a genetic algorithm. The overall goal was to reveal the implications of different propellant combinations and objective functions on the optimal design of the launcher for various mission scenarios. The results show that the optimization objective influences the most suitable propellant choice and the overall launcher design, concerning staging, weight, size, and rocket engine parameters. In terms of gross lift-off weight, liquid hydrogen seems to be favorable. When optimizing for a minimum structural mass or an expendable structural mass, hydrocarbon-based solutions show better results. Finally, launch vehicles using a hydrocarbon fuel in the first stage and liquid hydrogen in the upper stage are an appealing alternative, combining the benefits of both fuels. [ABSTRACT FROM AUTHOR]

Background: Allogeneic hematopoietic stem cell transplantation (HSCT) is a potentially curative option for children with both malignant and nonmalignant diseases. T‐cell depletion techniques may result in reduced transplant‐related mortality compared with unmanipulated grafts due to a lower incidence of GvHD. Methods: Immune recovery and outcome were analyzed in a cohort of 23 patients with malignant and nonmalignant diseases who received CD3+TCRαβ+ T‐ and B‐cell‐depleted allografts from matched donors after reduced‐intensity or myeloablative conditioning. The median number of CD34+, CD3+TCRαβ+, and CD19+B‐cells infused was 12.7 × 106/kg, 16.8 × 103/kg, and 96 × 103/kg bodyweight. Results: With a median follow‐up of 36 (range 1–73) months, overall survival and disease‐free survival at 3 years were 65.2% and 60.8%. Eight patients died, six due to the underlying disease and two of extended visceral cGvHD. Immune reconstitution, disease‐free, and overall survivals were similar compared with a historical cohort of 23 patients transplanted with matched unmanipulated bone marrow. A significant lower rate of higher grade (III‐IV) aGvHD was observed in the manipulated HSCT group (8.7% vs. 26%; p = 0.001), whereas the incidence of cGvHD was equal. Conclusions: Our data suggest that this graft manipulation strategy could be a safe and effective alternative to conventional HSCT techniques in matched donors. [ABSTRACT FROM AUTHOR]

• Human impacts contribute to biodiversity decline globally. • Global biodiversity modelling approaches focus on direct anthropogenic pressures. • Consideration of terrestrial and aquatic ecosystems as separate parts can be a challenge. • Global biodiversity modelling should consider interconnections of human interventions. • Models often lack recommendations on conservation strategies. Human impacts contribute to the reduction of biodiversity. To describe biodiversity loss and identify its causes, biologists (in particular ecologists) use a wide range of models. Globalised human interventions cause most biodiversity losses. Therefore, global biodiversity is taken as the level of observation. This also allows for the appreciation of the world as an environmental entity. Because humans play a dual role in the context of biodiversity loss, their "parameterisation" in such models is particularly interesting. On the one hand human influences can be categorised as disruptive factors because they transcend the biological needs of the individual human. On the other hand humans are themselves part of the biosphere, so their impact on the environment and biodiversity must also be qualified as a natural phenomenon. What at first glance appears contradictory can very well be embraced by models and modelling approaches. Consequently, we review ten different (global) biodiversity models on how they grasp human influences that consist of stressors (pressures) and also drivers (societal needs). This work's main expectation is that the reviewed models make certain assumptions, include some aspects and exclude others. In our review, we regard them as heuristic models. Thus, it is not the detailed algorithms we are interested in, but how human activities are included and depicted within the models. The model review also deploys a human ecology perspective, which includes an evolutionary and societal angle and consciously investigates (1) human adaptions to the environment and (2) human alterations of the environment. While our review clearly shows the widely shared understanding for the need of evidence-based countermeasures to act responsibly, very few models offer concrete recommendations but instead mostly limit their advice to the technical level of modelling. We conclude that policy advice, science communication, and concrete measures need to be improved in biodiversity models. [ABSTRACT FROM AUTHOR]

The establishment of new interdisciplinary fields such as ecological economics, human ecology or technology assessment can be interpreted as a logical consequence of striving for new sustainability sciences that address current global, multi-dimensional and multi-scale challenges. These set out to bridge the gap between the natural and the social sphere, between scientific analysis and societal action. This paper aims at re-assessing the contribution of established inter-disciplines to sustainable development. Journal articles of ecological economics, technology assessment and science and technology studies are evaluated and compared along several proposed features of sustainability science. The results converge in two crucial aspects. (1) Concise societal or political recommendations are not part of present day ‘normal science’, be it a disciplinary or an explicitly interdisciplinary research context. (2) Participatory exercises are rarely applied as a socio-politically embedded practice, despite a high interest in such exercises as an object of study and discussion. [Copyright &y& Elsevier]

Abstract: The overexploitation of natural resources and the increasing number of social conflicts following from their unsustainable use point to a wide gap between the objectives of sustainability and current resource management practices. One of the reasons for the difficulties to close this gap is that for evolving complex systems like natural and socio-economic systems, sustainability cannot be a static objective. Instead sustainable development is an open evolutionary process of improving the management of social–ecological systems, through better understanding and knowledge. Therefore, natural resource management systems need to be able to deal with different temporal, spatial and social scales, nested hierarchies, irreducible uncertainty, multidimensional interactions and emergent properties. The co-evolutionary perspective outlined in this paper serves as heuristic device to map the interactions settled in the networks between the resource base, social institutions and the behaviour of individual actors. For this purpose we draw on ideas from complex adaptive systems theory, evolutionary theory and evolutionary economics. Finally, we outline a research agenda for a co-evolutionary approach for natural resource management systems. [Copyright &y& Elsevier]

Background: The aims of this study are to determine (i) SARS-CoV-2 antibody positive employees in Austrian trauma hospitals and rehabilitation facilities, (ii) number of active virus carriers (symptomatic and asymptomatic) during the study, (iii) antibody decline in seropositive subjects over a period of around 6 months, (iv) the usefulness of rapid antibody tests for outpatient screening.Method: A total of 3301 employees in 11 Austrian trauma hospitals and rehabilitation facilities of the Austrian Social Insurance for Occupational Risks (AUVA) participated in this open uncontrolled prospective cohort study. Rapid lateral flow tests, detecting a combination of IgM and IgM against SARS-CoV-2), two different types of CLIA (Diasorin, Roche), RT-PCR tests and serum neutralization tests (SNTs) were performed. The tests were conducted twice, with an interval of 42.4 ± 7.7 (Min = 30, Max = 64) days. Positive participants were re-tested with CLIA/SNT at a third time point after 188.0 ± 12.8 days.Results: Only 27 out of 3301 participants (0.82%) had a positive antibody test at any time point during the study confirmed via neutralization test. Among positively tested participants in either test, 50.4% did not report any symptoms consistent with common manifestations of COVID-19 during the study period or within the preceding 6 weeks. In the group who tested positive during or prior to study inclusion the most common symptoms of an acute viral illness were rhinitis (21.9%), and loss of taste and olfactory sense (21.9%). Based on the neutralization test as the true condition, the rapid antibody test performed better on serum than whole blood as 84.6% instead of 65.4% could be detected correctly. Concerning both CLIA tests overall the Roche test detected 24 (sensitivity = 88.9%) and the Diasorin test 22 positive participants (sensitivity = 81.5%). In participants with a positive SNT result, a significant drop in neutralizing antibody titre from 31.8 ± 22.9 (Md = 32.0) at T1 to 26.1 ± 17.6 (Md = 21.3) at T2 to 21.4 ± 13.4 (Md = 16.0) at T3 (χ2 = 23.848, df = 2, p < 0.001) was observed (χ2 = 23.848, df = 2, p < 0.001)-with an average time of 42.4 ± 7.7 days between T1 and T2 and 146.9 ± 13.8 days between T2 and T3.Conclusions: During the study period (May 11th-August 3rd) only 0.82% were tested positive for antibodies in our study cohort. The antibody concentration decreases significantly over time with 14.8% (4 out of 27) losing detectable antibodies. [ABSTRACT FROM AUTHOR]

There is no doubt about 2-CDA being a very potent lymphotoxic agent that displays high efficacy in the treatment of CLL. It interferes with the intranuclear machinery of DNA regulation, and causes death to proliferative active, as well as resting lymphocytes. Interruption of crucial pathways that are evident for cell survival translates into high clinical response rates in CLL. CR and PR rates comparable to those reported on fludarabine are achieved in relapsed or refractory CLL. Even though trials on previously untreated CLL are still ongoing, a consistent trend towards durable, high CR rates becomes apparent. The toxicity is comparable to that of fludarabine and consists of infections, as well as thrombocytopenia. Clinical as well as in vitro studies suggest a crossresistance between the two purine analogues, indicating that sequential treatment is not useful. Given these data, although preliminary in case of de novo CLL, 2-CDA has to be recognized as one of the most effective cytostatic drugs currently available for CLL treatment. Large prospective trials (in comparison with fludarabine) will assess the role of 2-CDA as standard treatment. Such trials should also have the aim to substantiate the potential of 2-CDA as induction treatment followed by high-dose consolidation. [ABSTRACT FROM AUTHOR]

Background: The gold standard for the diagnosis of cholera is stool culture, but this requires laboratory facilities and takes at least 24 hours. A rapid diagnostic test (RDT) that can be used by minimally trained staff at treatment centers could potentially improve the reporting and management of cholera outbreaks. Methods: We evaluated the Crystal VC™ RDT under field conditions in Zanzibar in 2009. Patients presenting to treatment centers with watery diarrhea provided a stool sample for rapid diagnostic testing. Results were compared to stool culture performed in a reference laboratory. We assessed the overall performance of the RDT and evaluated whether previous intake of antibiotics, intravenous fluids, location of testing, and skill level of the technician affected the RDT results. Results: We included stool samples from 624 patients. Compared to culture, the overall sensitivity of the RDT was 93.1% (95%CI: 88.7 to 96.2%), specificity was 49.2% (95%CI: 44.3 to 54.1%), the positive predictive value was 47.0% (95%CI: 42.1 to 52.0%) and the negative predictive value was 93.6% (95%CI: 89.6 to 96.5%). The overall false positivity rate was 50.8% (213/ 419); fieldworkers frequently misread very faint test lines as positive. Conclusion: The observed sensitivity of the Crystal VC RDT evaluated was similar compared to earlier versions, while specificity was poorer. The current version of the RDT could potentially be used as a screening tool in the field. Because of the high proportion of false positive results when field workers test stool specimens, positive results will need to be confirmed with stool culture. [ABSTRACT FROM AUTHOR]

Background: Typhoid fever remains a significant health problem in many developing countries. A rapid test with a performance comparable to that of blood culture would be highly useful. A rapid diagnostic test for typhoid fever, Tubex®, is commercially available that uses particle separation to detect immunoglobulin M directed towards Salmonella Typhi O9 lipopolysaccharide in sera. Methods: We assessed the sensitivity and specificity of the Tubex test among Tanzanian children hospitalized with febrile illness using blood culture as gold standard. Evaluation was done considering blood culture confirmed S. Typhi with non-typhi salmonella (NTS) and non - salmonella isolates as controls as well as with non-salmonella isolates only. Results: Of 139 samples tested with Tubex, 33 were positive for S. Typhi in blood culture, 49 were cultureconfirmed NTS infections, and 57 were other non-salmonella infections. Thirteen hemolyzed samples were excluded. Using all non - S. Typhi isolates as controls, we showed a sensitivity of 79% and a specificity of 89%. When the analysis was repeated excluding NTS from the pool of controls we showed a sensitivity of 79% and a specificity of 97%. There was no significant difference in the test performance using the two different control groups (p > 0.05). Conclusion: This first evaluation of the Tubex test in an African setting showed a similar performance to those seen in some Asian settings. Comparison with the earlier results of a Widal test using the same samples showed no significant difference (p > 0.05) for any of the performance indicators, irrespective of the applied control group. [ABSTRACT FROM AUTHOR]

Background: The diagnosis of typhoid fever is confirmed by culture of Salmonella enterica serotype Typhi (S. typhi). However, a more rapid, simpler, and cheaper diagnostic method would be very useful especially in developing countries. The Widal test is widely used in Africa but little information exists about its reliability. Methods: We assessed the performance of the Widal tube agglutination test among febrile hospitalized Tanzanian children. We calculated the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of various anti-TH and -TO titers using culture-confirmed typhoid fever cases as the "true positives" and all other febrile children with blood culture negative for S. typhi as the "true negatives." Results: We found that 16 (1%) of 1,680 children had culture-proven typhoid fever. A single anti-TH titer of 1:80 and higher was the optimal indicator of typhoid fever. This had a sensitivity of 75%, specificity of 98%, NPV of 100%, but PPV was only 26%. We compared our main findings with those from previous studies. Conclusion: Among febrile hospitalized Tanzanian children with a low prevalence of typhoid fever, a Widal titer of ≥ 1:80 performed well in terms of sensitivity, specificity, and NPV. However a test with improved PPV that is similarly easy to apply and cost-efficient is desirable. [ABSTRACT FROM AUTHOR]

Background: The systemic inflammatory response syndrome (SIRS) is viewed as a system-wide inflammatory response. Up until now, no parameter has been available for predicting the development of septic shock. In the present study, we evaluated the usefulness of serum levels of CD14, vascular cell adhesion molecule-1 (VCAM-1), endothelial leucocyte adhesion molecule-1 (ELAM-1), macrophage inflammatory protein (MIP) 1α and transforming growth factor β[sub 2] (TGF-β[sub 2]) as early markers of outcome in patients with SIRS. Methods: A group of 28 SIRS patients (13 survivors/15 non-survivors) was compared with a healthy control group and with patients with local inflammation. Blood samples were analysed on days 0, 4 and 7. Proinflammatory parameters such as sCD14, sVCAM-1, sELAM-1, MIP-1α and anti-inflammatory parameters such as TGF-β[sub 2] were determined using enzyme-linked immunosorbent assay (ELISA). Results: At the beginning, all evaluated proinflammatory immunological parameters with the exception of sVCAM-1 were significantly increased in patients with SIRS compared with the healthy control group. However, no significant difference could be observed for all immunological parameters comparing survivors and non-survivors, with the exception of interleukin (IL) 6 at day 7. Conclusion: All evaluated proinflammatory parameters were increased in patients with SIRS during the course of the disease. However, the parameters have no correlation with outcome and prognosis of SIRS patients. [ABSTRACT FROM AUTHOR]

Background: Typhoid fever remains a significant health problem in many developing countries. A rapid test with a performance comparable to that of blood culture would be highly useful. A rapid diagnostic test for typhoid fever, Tubex®, is commercially available that uses particle separation to detect immunoglobulin M directed towards Salmonella Typhi O9 lipopolysaccharide in sera.Methods: We assessed the sensitivity and specificity of the Tubex test among Tanzanian children hospitalized with febrile illness using blood culture as gold standard. Evaluation was done considering blood culture confirmed S. Typhi with non-typhi salmonella (NTS) and non - salmonella isolates as controls as well as with non-salmonella isolates only.Results: Of 139 samples tested with Tubex, 33 were positive for S. Typhi in blood culture, 49 were culture-confirmed NTS infections, and 57 were other non-salmonella infections. Thirteen hemolyzed samples were excluded. Using all non - S. Typhi isolates as controls, we showed a sensitivity of 79% and a specificity of 89%. When the analysis was repeated excluding NTS from the pool of controls we showed a sensitivity of 79% and a specificity of 97%. There was no significant difference in the test performance using the two different control groups (p > 0.05).Conclusion: This first evaluation of the Tubex test in an African setting showed a similar performance to those seen in some Asian settings. Comparison with the earlier results of a Widal test using the same samples showed no significant difference (p > 0.05) for any of the performance indicators, irrespective of the applied control group. [ABSTRACT FROM AUTHOR]

Background: The diagnosis of typhoid fever is confirmed by culture of Salmonella enterica serotype Typhi (S. typhi). However, a more rapid, simpler, and cheaper diagnostic method would be very useful especially in developing countries. The Widal test is widely used in Africa but little information exists about its reliability.Methods: We assessed the performance of the Widal tube agglutination test among febrile hospitalized Tanzanian children. We calculated the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of various anti-TH and -TO titers using culture-confirmed typhoid fever cases as the "true positives" and all other febrile children with blood culture negative for S. typhi as the "true negatives."Results: We found that 16 (1%) of 1,680 children had culture-proven typhoid fever. A single anti-TH titer of 1:80 and higher was the optimal indicator of typhoid fever. This had a sensitivity of 75%, specificity of 98%, NPV of 100%, but PPV was only 26%. We compared our main findings with those from previous studies.Conclusion: Among febrile hospitalized Tanzanian children with a low prevalence of typhoid fever, a Widal titer of > or = 1:80 performed well in terms of sensitivity, specificity, and NPV. However a test with improved PPV that is similarly easy to apply and cost-efficient is desirable. [ABSTRACT FROM AUTHOR]