Adaptive Floor Cleaning Strategy by Human Density Surveillance Mapping with a Reconfigurable Multi-Purpose Service Robot.

Professional cleaning and safe social distance monitoring are often considered as demanding, time-consuming, repetitive, and labor-intensive tasks with the risk of getting exposed to the virus. Safe social distance monitoring and cleaning are emerging problems solved through robotics solutions. This research aims to develop a safe social distance surveillance system on an intra-reconfigurable robot with a multi-robot cleaning system for large population environments, like office buildings, hospitals, or shopping malls. We propose an adaptive multi-robot cleaning strategy based on zig-zag-based coverage path planning that works in synergy with the human interaction heat map generated by safe social distance monitoring systems. We further validate the proposed adaptive velocity model's efficiency for the multi-robot cleaning systems regarding time consumption and energy saved. The proposed method using sigmoid-based non-linear function has shown superior performance with 14.1 percent faster and energy consumption of 11.8 percent less than conventional cleaning methods.

Reinforcement Learning-Based Complete Area Coverage Path Planning for a Modified hTrihex Robot.

One of the essential attributes of a cleaning robot is to achieve complete area coverage. Current commercial indoor cleaning robots have fixed morphology and are restricted to clean only specific areas in a house. The results of maximum area coverage are sub-optimal in this case. Tiling robots are innovative solutions for such a coverage problem. These new kinds of robots can be deployed in the cases of cleaning, painting, maintenance, and inspection, which require complete area coverage. Tiling robots' objective is to cover the entire area by reconfiguring to different shapes as per the area requirements. In this context, it is vital to have a framework that enables the robot to maximize the area coverage while minimizing energy consumption. That means it is necessary for the robot to cover the maximum area with the least number of shape reconfigurations possible. The current paper proposes a complete area coverage planning module for the modified hTrihex, a honeycomb-shaped tiling robot, based on the deep reinforcement learning technique. This framework simultaneously generates the tiling shapes and the trajectory with minimum overall cost. In this regard, a convolutional neural network (CNN) with long short term memory (LSTM) layer was trained using the actor-critic experience replay (ACER) reinforcement learning algorithm. The simulation results obtained from the current implementation were compared against the results that were generated through traditional tiling theory models that included zigzag, spiral, and greedy search schemes. The model presented in the current paper was also compared against other methods where this problem was considered as a traveling salesman problem (TSP) solved through genetic algorithm (GA) and ant colony optimization (ACO) approaches. Our proposed scheme generates a path with a minimized cost at a lesser time.

Even-odd product variation of the C(n)(+) + D(2) (n = 4-9) reaction: complexity of the linear carbon cation electronic states.

We have studied reactions between linear Cn(+) (n = 4-9) and D2, using ion mobility mass spectrometry techniques and quantum chemical calculations in order to understand the complex reactivity of the linear cluster cations. Only linear CnD(+) products were observed for the odd (n = 5, 7, 9) linear clusters, while CnD2(+) was the main product for the even clusters. For the reaction rate constants determined for these two channels, we obtained the following two features: (1) the rate constant decreases with the size n, and (2) even-sized clusters have lower rate constants than neighboring odd-sized clusters. In the theoretical calculations using the CCSD(T) and B3LYP methods with the cc-pVTZ basis, we found that a low lying (2)Σ state in odd clusters may play an important role in these reactions. This opposes the previous interpretation that the (2)Πg/u state is the dominant electronic state for linear Cn(+) (n = 4-9) clusters. We showed that a barrierless radical abstraction forming CnD(+) occurs through a direct head on approach for the (2)Σ state Cn(+). In contrast, a carbene-like insertion forming CnD2(+) occurs through a sideways approach for the (2)Πg/u state Cn(+). We have concluded that the higher rate constants for the odd clusters come from the existence of symmetry broken (2)Σ states which are absent in even linear clusters.

Mechanochromic behavior of aryl-substituted buta-1,3-diene derivatives with aggregation enhanced emission.

Three tetra-aryl substituted 1,3-butadiene derivatives with aggregation enhanced emission (AEE) and mechanochromic fluorescence behavior have been rationally designed and synthesized. The results suggest an effective design strategy for developing diverse materials with aggregation induced emission (AIE) and significant mechanochromic performance by employing D-π-A structures with large dipole moments.

Spontaneous Combustion Characteristics of Activated Carbon Modified via Liquid Phase Impregnation during Drying.

Spontaneous combustion characteristics are important issues for the safe operation of the wet-modified activated carbon drying process. The spontaneous combustion characteristics of activated carbon modified via liquid phase impregnation were fully investigated in this study. The modified activated carbon was prepared using columnar activated carbon and 4-amino-1,2-butanediol solution. Physical properties and surface functional group analyses were performed for activated carbon before and after modification. The ignition temperature of activated carbon before and after modification was then characterized using the methods of GB/T20450-2006, thermogravimetry-derivative thermogravimetry (TG-DTG), and TG-mass spectrometry (TG-MS). At the same time, the activation energy of activated carbon before and after modification was calculated by using thermodynamic analysis. Furthermore, a new self-designed test platform was introduced to investigate the spontaneous combustion characteristics of wet-modified activated carbon under the drying temperatures of 150, 175, 180, and 210 °C. The results show that the specific surface area of Brunauer, Emmett, and Teller (BET) is decreased by 368 m2·g-1, the total volume of pore size is decreased by 0.17 cm3·g-1, and the content of oxygen-containing functional groups is decreased by 0.071 mmol/g compared with row activated carbon. The ignition temperatures of the sample before modification characterized by the three methods are 483, 596, and 599 °C, respectively. The ignition temperatures of the sample after modification are 489, 607, and 611 °C, respectively. The activation energy of the modified activated carbon is increased by 35 kJ/mol compared to the original activated carbon. It is concluded that the temperature that triggers the modified activated carbon combustion during the drying process is between 175 and 180 °C, and the heat is mainly gathered at the longitudinal center of the combustion chamber through the investigation of spontaneous combustion experiments. The results in this study can contribute to safe production to prevent combustion in the process of modifying activated carbon during the drying process.

Impaired SARS-CoV-2 specific T-cell response in patients with severe COVID-19.

Cellular immune responses are of pivotal importance to understand SARS-CoV-2 pathogenicity. Using an enzyme-linked immunosorbent spot (ELISpot) interferon-γ release assay with wild-type spike, membrane and nucleocapsid peptide pools, we longitudinally characterized functional SARS-CoV-2 specific T-cell responses in a cohort of patients with mild, moderate and severe COVID-19. All patients were included before emergence of the Omicron (B.1.1.529) variant. Our most important finding was an impaired development of early IFN-γ-secreting virus-specific T-cells in severe patients compared to patients with moderate disease, indicating that absence of virus-specific cellular responses in the acute phase may act as a prognostic factor for severe disease. Remarkably, in addition to reactivity against the spike protein, a substantial proportion of the SARS-CoV-2 specific T-cell response was directed against the conserved membrane protein. This may be relevant for diagnostics and vaccine design, especially considering new variants with heavily mutated spike proteins. Our data further strengthen the hypothesis that dysregulated adaptive immunity plays a central role in COVID-19 immunopathogenesis.

Quantitative Structure-Property Relationship Analysis for the Prediction of Propylene Adsorption Capacity in Pure Silicon Zeolites at Various Pressure Levels.

This work is devoted to the development of quantitative structure-property relationship (QSPR) models using various regression analyses to predict propylene (C3H6) adsorption capacity at various pressures in zeolites from a topologically diverse International Zeolite Association database. Based on univariate and multilinear regression analysis, the accessible volume and largest cavity diameter are the most crucial factors determining C3H6 uptake at high and low pressures, respectively. An artificial neural network (ANN) model with five structural descriptors is sufficient to predict C3H6 uptake at high pressures. For combined pressures, the prediction of an ANN model with pore size distribution is pleasing. The isosteric heat of adsorption (Q st) has a significant impact on the improvement of the prediction of low-pressure gas adsorption, which finely classifies zeolites into high or low C3H6 adsorbers. The conjunction of high-throughput screening and QSPR models contributes to being able to prescreen the database rapidly and accurately for top performers and perform further detailed and time-consuming computational-intensive molecular simulations on these candidates for other gas adsorption applications.

Levetiracetam in spinal cord injury pain: a randomized controlled trial.

STUDY DESIGN: A randomized, double-blind, placebo-controlled, crossover, multicenter trial. A 1-week baseline period was followed by two treatment periods of 5 weeks duration with levetiracetam increased from 500 mg b.i.d. to a maximum of 1500 mg b.i.d. separated by a 1-week washout period. OBJECTIVES: The objective of the study was primarily to evaluate the efficacy of the anticonvulsant levetiracetam in patients with spinal cord injury (SCI) at- and below-level pain and secondarily to evaluate the effect on spasm severity. SETTING: Outpatients at two spinal cord units and a pain center. METHODS: Patients were allowed to continue their usual pain treatment at a constant dose. The primary outcome measure was the change in median daily pain score (on a 0-10 point numeric rating scale) from 1-week baseline period to the last week of each treatment period. Secondary outcome measures included pain relief of at- and below-level pain, allodynia, spasms and spasticity. RESULTS: A total of 36 patients with SCI at- and or below-level pain were enrolled. Of these, 24 patients completed the trial. We found no effect of levetiracetam on the primary (P=0.46) or any of the secondary outcome measures. Only two patients continued levetiracetam treatment following the trial, and one patient was still in levetiracetam treatment at the 6-month follow-up. Levetiracetam was generally well tolerated with no serious adverse events. CONCLUSIONS: Levetiracetam does not relieve neuropathic pain or spasm severity following spinal cord injury.

Insecticidal proteins from Bacillus thuringiensis protect corn from corn rootworms.

Field tests of corn co-expressing two new delta-endotoxins from Bacillus thuringiensis (Bt) have demonstrated protection from root damage by western corn rootworm (Diabrotica virgifera virgifera LeConte). The level of protection exceeds that provided by chemical insecticides. In the bacterium, these proteins form crystals during the sporulation phase of the growth cycle, are encoded by a single operon, and have molecular masses of 14 kDa and 44 kDa. Corn rootworm larvae fed on corn roots expressing the proteins showed histopathological symptoms in the midgut epithelium.

Localization of binding sites for laminin, heparan sulfate proteoglycan and fibronectin on basement membrane (type IV) collagen.

Rotary shadowing electron microscopy was used to examine complexes formed by incubating combinations of the basement membrane components: type IV collagen, laminin, large heparan sulfate proteoglycan and fibronectin. Complexes were analyzed by length measurement from the globular (COOH) domain of type IV collagen, and by examination of the four arms of laminin and the two arms of fibronectin. Type IV collagen was found to contain binding sites for laminin, heparan sulfate proteoglycan and fibronectin. With laminin the most frequent site was centered approximately 81 nm from the carboxy end of type IV collagen. Less frequent sites appeared to be present at approximately 216 nm and approximately 291 nm, although this was not apparent when the sites were expressed as a fraction of the length of type IV collagen to which they were bound. For heparan sulfate proteoglycan the most frequent site occurred at approximately 206 nm with a less frequent site at approximately 82 nm. For fibronectin, a single site was present at approximately 205 nm. Laminin bound to type IV collagen through its short arms, particularly through the end of the lateral short arms and to heparan sulfate proteoglycan mainly through the end of its long arm. Fibronectin bound to type IV collagen through the free end region of its arms. Using a computer graphics program, the primary laminin binding sites of two adjacent type IV collagen molecules were found to align in the "polygonal" model of type IV collagen, whereas with the "open network" model, a wide meshed matrix is predicted. It is proposed that basement membrane may consist of a lattice of type IV collagen coated with laminin, heparan sulfate proteoglycan and fibronectin.

[Tracheobronchial foreign bodies]. / Corps étrangers trachéobronchiques.

Forty cases of children with an inhaled foreign body (FB) are reviewed over a three-year period. Clinical data, radiologic findings and complications are detailed. The nature and size of FBs are also reported. Diagnosis and management are discussed according to the most recent studies in the literature. Diagnostic flexible bronchoscopy is a useful first step when the diagnosis is unclear (i.e., choking history, unexplained respiratory symptoms), but FB removal is usually not possible during this procedure. Extraction is performed via the rigid bronchoscope under general anesthesia. However, FB could be removed with the flexible bronchoscope in five children in our study. Diagnosis and removal of an inhaled FB are required as quickly as possible in order to prevent respiratory sequelae (bronchiectasis). Prevention is based upon information to be given to families, but to the medical community as well, which often minimizes the seriousness of inhalation hazards.

[General anesthesia in a patient with catecholaminergic polymorph ventricular tachycardia]. / Anesthésie générale chez une patiente atteinte de tachycardie ventriculaire polymorphe catécholergique.

A patient suffering from a catecholaminergic polymorph ventricular tachycardia treated with nadolol was scheduled for dental extractions under general anaesthesia. During induction, whereas the basal heart rate was at 30-35 b.min-1, occurred an episode of bidirectional ventricular tachycardia probably induced by the administration of pancuronium.

[Emergency translaryngeal ventilation with a Tuohy needle. Use in case of an inability to intubate and ventilate a curarized patient]. / Ventilation translaryngée de sauvetage par aiguille de Tuohy. Utilisation en cas d'impossibilité d'intuber et de ventiler un patient curarisé.

Intermittent translaryngeal insufflations of oxygen at high pressure by a needle could be a life-saving procedure, especially in a patient whose trachea the anesthesiologist was unable to intubate or ventilate. This study was designed to evaluate the quality of translaryngeal ventilation performed with a 16-gauge Tuohy needle and an oxygen pressure of 3 bar (300 kPa) in comparison with an usual plastic cannula of the same calibre. The studies carried out in the laboratory have shown a distinct advantage over the conventional cannula. Whereas an O2 jet delivered by a straight cannula impinged on the posterior wall of the larynx and trachea, the curved tip of the Tuohy needle deflected the axis of the O2 flow emerging from it, which then lay parallel to the longitudinal axis of the trachea. Consequently, gas flow through a simulated trachea was increased (2610 ml X s-1 vs 1240 ml X s-1), the inflation pressure being higher and the tidal volume larger. Moreover, the likelihood of injury to the posterior wall of the airway was reduced; the Tuohy needle held with a clamp close to the skin was more stable in position. Blood gases and clinical data obtained in 10 anesthetized and curarized patients without airway obstruction made it clear that translaryngeal insufflations with a 16-gauge Tuohy needle provided adequate ventilation (PaO2 values between 174 and 851 mmHg, PaCO2 between 38 and 64 mmHg). It was concluded that this technique was an efficient alternative in case of an inability to intubate a patient in apnea.

[The laryngeal mask]. / Le masque laryngé.

The laryngeal mask (LM) is a new concept developed by Brain. Easily inserted, the LM allows appropriate ventilation without the disadvantages of either the facial mask or the endotracheal intubation with its own complications. The limits of its use concern all the cases of reduction of thoracopulmonary compliance and full stomach. The LM offers no protection against regurgitation and aspiration. Airway obstruction may occur following laryngospasm (light anaesthesia) or down folding of the epiglottis. Trauma to the uvula and the posterior pharyngeal wall have been reported. The LM may be useful in all cases of surgery in which intubation is not absolutely required. Moreover, the LM is widely used for ENT and ophthalmic surgeries, in paediatric and adult procedures. Many cases of foreseeable or unforeseeable difficult intubation have been resolved by the insertion of a LM, allowing secondary intubation through the mask. Further investigations are required in order to evaluate the real limits and indications for its extended use.

Undergraduate performance in a domestic animal laboratory taught via distance education.

The objective of this study was to determine if laboratory modules of an undergraduate animal anatomy course offered in distance education (DistEd) format were as effective as face-to-face (F2F) format in helping students learn. Students (n = 159) completed an anatomy pretest as well as a presurvey to assess prior DistEd experience. Alternating each week, laboratory topics were presented either as F2F or as virtual DistEd laboratories. Two laboratory examinations were administered and included material from both laboratory formats (DistEd and F2F). Questions from the pretest were also included and used to generate the posttest scores. At the end of the semester, students completed a postsurvey to determine if DistEd was a viable alternative to F2F. Student grades on each examination were compared using an ANOVA model that included main effects of presentation method (DistEd, F2F), semester (fall, spring), and their interaction. Learning was evaluated based on the performances of students on pre- and posttests using unpaired t-tests. There was an increase (P < 0.0001) in anatomy post- vs. pretest scores for both semesters, indicative of student learning, although there was no effect of presentation method (F2F or DistEd). On exam 1, students achieved greater scores in fall 2008 (P < 0.0001) on material presented via DistEd compared with that presented as F2F. However, in spring 2009 students scored better on material presented as F2F. There was no effect of presentation method on exam 2 scores for either semester. Based on the postsurvey, 79.3% of students in fall 2008 and 52% of students from spring 2009 agreed that DistEd laboratories were a viable alternative to F2F laboratories. The results of this study support the conclusion that anatomy material can be taught effectively by distance education methods.