120 research outputs found
âWe Have to Record the Downfall of Tyrannyâ: The London Times Perspective on Napoleon Bonaparteâs Invasion of Russia
We Have to Record the Downfall of Tyranny : The London Times Perspective on Napoleon Bonaparte\u27s Invasion of Russia aims to illustrate how The London Times interpreted and reported on Napoleon\u27s 1812 invasion of Russia. This thesis explains how England feared its grip on Europe was slipping away due to a French takeover of the continent. This work details the English struggle in order to provide a broader analysis through a newspaper of how nations indirectly involved in the Napoleonic wars understood the conflict
Simulation-based surface roughness modelling in end milling
The surface topography often is an important quality criterion for the manufacturing of milled workpieces as it often defines their functional behaviour. In machining both, the kinematics of the process and the stochastic influences deriving from the machine tool, workpiece and the surrounding environment affect the workpiece's surface roughness. This paper presents a simulation-based method for flank milling, which considers kinematic and stochastic influences including run-out errors and tooth length variations. The simulation results are used in combination to predict the surface roughness depending on the chosen process parameters. Hence, also making in possible to choose appropriate process parameters to achieve a defined surface roughness
Simulation-based feed rate adaptation considering tool wear condition
The process forces generated in machining are related to a deflection of the milling tool, which results in shape deviations. In addition to process parameters like feed rate, width and depth of cut or cutting speed, the wear condition of the tool has a significant influence on the shape deviation during flank milling. In process planning it is important to take the tool condition and the ideal time for tool change into account when selecting the process parameters. An assistance system is being researched at the Institute of Production Engineering and Machine T ools (IFW) in cooperation with Kennametal Shared Services GmbH to support this task. T he assistance system adjusts automatically the feed rate considering a predefined maximum shape deviation. Additionally, it identifies an optimal moment for tool change. T he advantages of the system are particularly evident in planning of individual milling processes. T he assistance system is based on a combination of a material removal simulation and empirical models of the shape error. For this purpose, spindle currents as well as measured shape errors are stored in a database. T hese data are extended by the actual local cutting conditions calculated by a process-parallel material removal simulation. Afterwards, the data is transferred into process knowledge via a Support Vector Machine (SVM). Within a technological NC simulation before the start of manufacturing, the generated knowledge is applied to predict the shape error of the workpiece and to automatically adjust the feed rate. By adapting the feed rate, it is possible to control the tool life. T he required tool change is defined by specifying a limit for the permitted width of flank wear land. T he presented assistance system enables the prediction of the shape error parallel to the manufacturing process and the automatic determination of the feed rate as well as the ideal time for tool change
Traceless Isoprenylation of Aldehydes via NâBocâNâ(1,1âdimethylallyl)hydrazones
A short isoprenylation protocol starting from nonâconjugated NâBocâNâ(1,1âdimethylallyl)hydrazones was developed utilising Thomson's traceless bond construction. This type of [3,3]âsigmatropic rearrangement is catalysed by the BrĂžnsted acid triflimide and liberates only gaseous byâproducts. The required NâBocâNâallylhydrazine precursor is available in three steps starting from a known diazene using biocatalytic aldol addition and Tebbe olefination as key steps. Allylhydrazones are prepared via condensation with appropriate aldehydes. Scope and limitations of the [3,3]âsigmatropic rearrangements are analysed
Stakeholders, Roles, Workflows and Requirements
Decisions makers in cities and urban areas continuously have to make important decisions to react or proactively identify new challenges, problems and conflicts. But as cities and urban areas have become more complex, wellâfounded decisions have also become more difficult to make. Decisions cannot be purely based on intuitions but require a basis for assessments, which put great constraints on decision makers and decision making procedures in terms of expertise and knowledge. New technology and sources of information can, however, support decision makers and facilitate the decision making procedures, but at the moment these possibilities are not being leveraged to a greater extent in urban governance
Phase transition in a stochastic prime number generator
We introduce a stochastic algorithm that acts as a prime number generator.
The dynamics of such algorithm gives rise to a continuous phase transition
which separates a phase where the algorithm is able to reduce a whole set of
integers into primes and a phase where the system reaches a frozen state with
low prime density. We present both numerical simulations and an analytical
approach in terms of an annealed approximation, by means of which the data are
collapsed. A critical slowing down phenomenon is also outlined.Comment: accepted in PRE (Rapid Comm.
Association of Lymphatic Abnormalities with Early Complications after Fontan Operation.
BACKGROUND
âIncreased central venous pressure is inherent in Fontan circulation but not strongly related to Fontan complication. Abnormalities of the lymphatic circulation may play a crucial role in early Fontan complications.
METHODS
âThis was a retrospective, single-center study of patients undergoing Fontan operation from 2008 to 2015. The primary outcome was significant early Fontan complication defined as secondary in-hospital treatment due to peripheral edema, ascites, pleural effusions, protein-losing enteropathy, or plastic bronchitis. All patients received T2-weighted magnetic resonance images to assess abdominal and thoracic lymphatic perfusion pattern 6 months after Fontan completion with respect to localization, distribution, and extension of lymphatic perfusion pattern (type 1-4) and with application of an area score (0-12 points).
RESULTS
âNine out of 42 patients developed early Fontan complication. Patients with complication had longer chest tube drainage (mean 28 [interquartile range [IQR]: 13-60] vs. 13 [IQR: 2-22] days, pâ=â0.01) and more often obstructions in the Fontan circuit 6 months after surgery (56 vs. 15%, pâ=â0.02). Twelve patients showed little or no abnormalities of lymphatic perfusion (lymphatic perfusion pattern type 1). Most frequently magnetic resonance imaging showed lymphatic congestion in the supraclavicular region (24/42 patients). Paramesenteric lymphatic congestion was observed in eight patients. Patients with early Fontan complications presented with higher lymphatic area score (6 [min-max: 2-10] vs. 2 [min-max: 0-8]), pâ=â0.001) and greater distribution and extension of thoracic lymphatic congestion (type 3-4: nâ=â5/9 vs. nâ=â1/33, pâ=â0.001).
CONCLUSION
âEarly Fontan complication is related to hemodynamic factors such as circuit obstruction and to the occurrence and extent of lymphatic congestion
Relation of Whole Blood Amino Acid and Acylcarnitine Metabolome to Age, Sex, BMI, Puberty, and Metabolic Markers in Children and Adolescents
Background: Changes in the metabolic fingerprint of blood during child growth and development are a largely under-investigated area of research. The examination of such aspects requires a cohort of healthy children and adolescents who have been subjected to deep phenotyping, including collection of biospecimens for metabolomic analysis. The present study considered whether amino acid (AA) and acylcarnitine (AC) concentrations are associated with age, sex, body mass index (BMI), and puberty during childhood and adolescence. It also investigated whether there are associations between amino acids (AAs) and acylcarnitines (ACs) and laboratory parameters of glucose and lipid metabolism, as well as liver, kidney, and thyroid parameters. Methods: A total of 3989 dried whole blood samples collected from 2191 healthy participants, aged 3 months to 18 years, from the LIFE Child cohort (Leipzig, Germany) were analyzed using liquid chromatography tandem mass spectrometry to detect levels of 23 AAs, 6 ACs, and free carnitine (C0). Age- and sex-related percentiles were estimated for each metabolite. In addition, correlations between laboratory parameters and levels of the selected AAs and ACs were calculated using hierarchical models. Results: Four different age-dependent profile types were identified for AAs and ACs. Investigating the association with puberty, we mainly identified peak metabolite levels at Tanner stages 2 to 3 in girls and stages 3 to 5 in boys. Significant correlations were observed between BMI standard deviation score (BMI-SDS) and certain metabolites, among them, branched-chain (leucine/isoleucine, valine) and aromatic (phenylalanine, tyrosine) amino acids. Most of the metabolites correlated significantly with absolute concentrations of glucose, glycated hemoglobin (HbA1c), triglycerides, cystatin C (CysC), and creatinine. After age adjustment, significant correlations were observed between most metabolites and CysC, as well as HbA1c. Conclusions: During childhood, several AA and AC levels are related to age, sex, BMI, and puberty. Moreover, our data verified known associations but also revealed new correlations between AAs/ACs and specific key markers of metabolic function
Lenalidomide and dexamethasone in relapsed/refractory immunoglobulin light chain (AL) amyloidosis: results from a large cohort of patients with long follow-up.
SummaryLenalidomide and dexamethasone (RD) is a standard treatment in relapsed/refractory immunoglobulin light chain (AL) amyloidosis (RRAL). We retrospectively investigated toxicity, efficacy and prognostic markers in 260 patients with RRAL. Patients received a median of two prior treatment lines (68% had been bortezomibârefractory; 33% had received highâdose melphalan). The median treatment duration was four cycles. The 3âmonth haematological response rate was 31% [very good haematological response (VGHR) in 18%]. The median followâup was 56·5 months and the median overall survival (OS) and haematological eventâfree survival (haemEFS) were 32 and 9 months. The 2âyear dialysis rate was 15%. VGHR resulted in better OS (62 vs. 26 months, P < 0·001). Cardiac progression predicted worse survival (22 vs. 40 months, P = 0·027), although Nâterminal prohormone of brain natriuretic peptide (NTâproBNP) increase was frequently observed. Multivariable analysis identified these prognostic factors: NTâproBNP for OS [hazard ratio (HR) 1·71; P < 0·001]; gain 1q21 for haemEFS (HR 1·68, P = 0·014), with a trend for OS (HR 1·47, P = 0·084); difference between involved and uninvolved free light chains (dFLC) and light chain isotype for OS (HR 2·22, P < 0·001; HR 1·62, P = 0·016) and haemEFS (HR 1·88, P < 0·001; HR 1·59, P = 0·008). Estimated glomerular filtration rate (HR 0·71, P = 0·004) and 24âh proteinuria (HR 1·10, P = 0·004) were prognostic for renal survival. In conclusion, clonal and organ biomarkers at baseline identify patients with favourable outcome, while VGHR and cardiac progression define prognosis during RD treatment
First experience with Tolvaptan for the treatment of neonates and infants with capillary leak syndrome after cardiac surgery
Background: Postoperative fluid management in critically ill neonates and infants with capillary leak syndrome (CLS) and extensive volume overload after cardiac surgery on cardiopulmonary bypass is challenging. CLS is often resistant to conventional diuretic therapy, aggravating the course of weaning from invasive ventilation, increasing length of stay on ICU and morbidity and mortality.
Methods: Tolvaptan (TLV, vasopressin type 2 receptor antagonist) was used as an additive diuretic in neonates and infants with CLS after cardiac surgery. Retrospective analysis of 25 patients with CLS including preoperative and postoperative parameters was performed. Multivariate regression analysis was performed to identify predictors for TLV response.
Results: Multivariate analysis identified urinary output during 24âh after TLV administration and mean blood pressure (BP) on day 2 of TLV treatment as predictors for TLV response (AUCâ=â0.956). Responder showed greater weight reduction (pâ<â0.0001), earlier weaning from ventilator during TLV (pâ=â0.0421) and shorter time in the ICU after TLV treatment (pâ=â0.0155). Serum sodium and serum osmolality increased significantly over time in all patients treated with TLV.
Conclusion: In neonates and infants with diuretic-refractory CLS after cardiac surgery, additional aquaretic therapy with TLV showed an increase in urinary output and reduction in bodyweight in patients classified as TLV responder. Increase in urinary output and mean BP on day 2 of treatment were strong predictors for TLV response
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