A hyper-heuristic with two guidance indicators for bi-objective mixed-shift vehicle routing problem with time windows

In this paper, a Mixed-Shift Vehicle Routing Problem is proposed based on a real-life container transportation problem. In a long planning horizon of multiple shifts, transport tasks are completed satisfying the time constraints. Due to the different travel distances and time of tasks, there are two types of shifts (long shift and short shift) in this problem. The unit driver cost for long shifts is higher than that of short shifts. A mathematical model of this Mixed-Shift Vehicle Routing Problem with Time Windows (MS-VRPTW) is established in this paper, with two objectives of minimizing the total driver payment and the total travel distance. Due to the large scale and nonlinear constraints, the exact search showed is not suitable to MS-VRPTW. An initial solution construction heuristic (EBIH) and a selective perturbation Hyper-Heuristic (GIHH) are thus developed. In GIHH, five heuristics with different extents of perturbation at the low level are adaptively selected by a high level selection scheme with the Hill Climbing acceptance criterion. Two guidance indicators are devised at the high level to adaptively adjust the selection of the low level heuristics for this bi-objective problem. The two indicators estimate the objective value improvement and the improvement direction over the Pareto Front, respectively. To evaluate the generality of the proposed algorithms, a set of benchmark instances with various features is extracted from real-life historical datasets. The experiment results show that GIHH significantly improves the quality of the final Pareto Solution Set, outperforming the state-of-the-art algorithms for similar problems. Its application on VRPTW also obtains promising results

In-vivo X-ray Dark-Field Chest Radiography of a Pig

X-ray chest radiography is an inexpensive and broadly available tool for initial assessment of the lung in clinical routine, but typically lacks diagnostic sensitivity for detection of pulmonary diseases in their early stages. Recent X-ray dark-field (XDF) imaging studies on mice have shown significant improvements in imaging-based lung diagnostics. Especially in the case of early diagnosis of chronic obstructive pulmonary disease (COPD), XDF imaging clearly outperforms conventional radiography. However, a translation of this technique towards the investigation of larger mammals and finally humans has not yet been achieved. In this letter, we present the first in-vivo XDF full-field chest radiographs (32 × 35 cm²) of a living pig, acquired with clinically compatible parameters (40s scan time, approx. 80 μSv dose). For imaging, we developed a novel high-energy XDF system that overcomes the limitations of currently established setups. Our XDF radiographs yield sufficiently high image quality to enable radiographic evaluation of the lungs. We consider this a milestone in the bench-to-bedside translation of XDF imaging and expect XDF imaging to become an invaluable tool in clinical practice, both as a general chest X-ray modality and as a dedicated tool for high-risk patients affected by smoking, industrial work and indoor cooking

Einsatz der ICP-Massenspektrometrie zur Multielementbestimmung in biologischen Proben

SIGLEAvailable from TIB Hannover: RO 7101(45) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Neurocognitive sequelae of Long-Covid: A Scoping Review

The objective of this scoping review is to report and synthesize cognitive Long-Covid/Post-Covid study results on neurocognitive performance for any adult patient cohort

Conformation and Dynamics of a Cyclic Disulfide-Bridged Peptide: Effects of Temperature and Solvent

The cyclic disulfide-bridged tetrapeptide cyclo-(Boc-Cys-Pro-Gly-Cys-OMe) (1) was designed as a model for the study of solvent-driven conformational changes in peptides. The three-dimensional structure and dynamics of 1 were studied using a variety of experimental and computational techniques. The crystal structure of 1 reveals a β-turn stabilized by a hydrogen bond between the two cysteine residues. In solution, the UV−CD and NMR analysis of 1 suggest a β-turn II conformation, stable up to 60 °C. The characteristic NMR 13C shifts of the Cβ and Cγ atoms of proline show that the peptide adopts exclusively the energetically favored trans conformation of the peptidyl-prolyl bond. The combination of IR spectroscopy with Car−Parrinello MD simulations and DFT calculations allowed us to assign the absorptions in the amide I region to the individual amino acids. The NH group of Gly, which as hydrogen bond donor competes with the NH group of Cys4 for the carbonyl oxygen atom of Cys1 as hydrogen bond acceptor, plays a relevant role for the structure and spectroscopic properties of the peptide. Since Gly is more exposed to the solvent, its hydrogen-bonding capability can be partially blocked by external solvent molecules in solution or by a second peptide molecule in the crystal. Furthermore, the presence of only one molecule of acetonitrile is sufficient to change the preferred conformation of 1, and even in acetonitrile solution the simulations suggest that on average only one solvent molecule strongly interacts with the cyclic core of the peptide

Longitudinal Neurocognitive and Pulmonological Profile of Long COVID-19: Protocol for the COVIMMUNE-Clin Study

BackgroundThere is a dearth of information about “brain fog,” characterized by concentration, word-finding, or memory problems, which has been listed in the new World Health Organization provisional classification “U09.9 Post-COVID-19 Condition.” Moreover, the extent to which these symptoms may be associated with neurological, pulmonary, or psychiatric difficulties is unclear. ObjectiveThis ongoing cohort study aims to carefully assess neurocognitive function in the context of the neurological, psychiatric, and pulmonary sequelae of SARS-CoV-2 infection among patients with asymptomatic/mild and severe cases of COVID-19 after remission, including actively recruited healthy controls. MethodsA total of 150 participants will be included in this pilot study. The cohort will comprise patients who tested positive for SARS-CoV-2 infection with either an asymptomatic course or a mild course defined as no symptoms except for olfactory and taste dysfunction (n=50), patients who tested positive for SARS-CoV-2 infection with a severe disease course (n=50), and a healthy control group (n=50) with similar age and sex distribution based on frequency matching. A comprehensive neuropsychological assessment will be performed comprising nuanced aspects of complex attention, including language, executive function, verbal and visual learning, and memory. Psychiatric, personality, social and lifestyle factors, sleep, and fatigue will be evaluated. Brain magnetic resonance imaging, neurological and physical assessment, and pulmonological and lung function examinations (including body plethysmography, diffusion capacity, clinical assessments, and questionnaires) will also be performed. Three visits are planned with comprehensive testing at the baseline and 12-month visits, along with brief neurological and neuropsychological examinations at the 6-month assessment. Blood-based biomarkers of neurodegeneration will be quantified at baseline and 12-month follow-up. ResultsAt the time of submission, the study had begun recruitment through telephone and in-person screenings. The first patient was enrolled in the study at the beginning of April 2021. Interim data analysis of baseline information is expected to be complete by December 2021 and study completion is expected at the end of December 2022. Preliminary group comparisons indicate worse word list learning, short- and long-delayed verbal recall, and verbal recognition in both patient cohorts compared with those of the healthy control group, adjusted for age and sex. Initial volumetric comparisons show smaller grey matter, frontal, and temporal brain volumes in both patient groups compared with those of healthy controls. These results are quite robust but are neither final nor placed in the needed context intended at study completion. ConclusionsTo the best of our knowledge, this is the first study to include objective and comprehensive longitudinal analyses of neurocognitive sequelae of COVID-19 in an extreme group comparison stratified by disease severity with healthy controls actively recruited during the pandemic. Results from this study will contribute to the nascent literature on the prolonged effects of COVID-19 on neurocognitive performance via our coassessment of neuroradiological, neurological, pulmonary, psychiatric, and lifestyle factors. Trial RegistrationInternational Clinical Trials Registry Platform DRKS00023806; https://trialsearch.who.int/Trial2.aspx?TrialID=DRKS00023806 International Registered Report Identifier (IRRID)DERR1-10.2196/3025

Photon-Counting Spectral Phase-Contrast Mammography

Phase-contrast imaging is an emerging technology that may increase the signal-difference-to-noise ratio in medical imaging. One of the most promising phase-contrast techniques is Talbot interferometry, which, combined with energy-sensitive photon-counting detectors, enables spectral differential phase-contrast mammography. We have evaluated a realistic system based on this technique by cascaded-systems analysis and with a task-dependent ideal-observer detectability index as a figure-of-merit. Beam-propagation simulations were used for validation and illustration of the analytical framework. Differential phase contrast improved detectability compared to absorption contrast, in particular for fine tumor structures. This result was supported by images of human mastectomy samples that were acquired with a conventional detector. The optimal incident energy was higher in differential phase contrast than in absorption contrast when disregarding the setup design energy. Further, optimal weighting of the transmitted spectrum was found to have a weaker energy dependence than for absorption contrast. Taking the design energy into account yielded a superimposed maximum on both detectability as a function of incident energy, and on optimal weighting. Spectral material decomposition was not facilitated by phase contrast, but phase information may be used instead of spectral information.QC 20120731</p