Inevitable Contact Research Articles

Interactions Between Potentially Toxic Nanoparticles (Cu, CuO, ZnO, and TiO2) and the Cyanobacterium Arthrospira platensis: Biological Adaptations to Xenobiotics.

(1) Background: The widespread use of nanoparticles (NPs) implies their inevitable contact with living organisms, including aquatic microorganisms, making it essential to understand the effects and consequences of this interaction. Understanding the adaptive responses and biochemical changes in microalgae and cyanobacteria under NP-induced stress is essential for developing biotechnological strategies that optimize biomolecule production while minimizing potential toxicity. This study aimed to evaluate the interactions between various potentially toxic nanoparticles and the cyanobacterial strain Arthrospira platensis, focusing on the biological adaptations and biochemical mechanisms that enable the organism to withstand xenobiotic exposure. (2) Methods: The cyanobacterium Arthrospira platensis CNMN-CB-02 was cultivated under optimal laboratory conditions in the presence of CuNPs, CuONPs, ZnONPs, and TiO2NPs. Biochemical analyses were performed on the collected biomass. (3) Results: Various interactions between nanoparticles (NPs) and the cyanobacterial culture were identified, ranging from hormetic effects at low concentrations to evident toxic effects at high concentrations. NP toxicity was observed through the reduction in photosynthetic pigments and the disappearance of phycobiliproteins. Notably, NP toxicity was not always accompanied by increased malondialdehyde (MDA) levels. (4) Conclusions: Arthrospira platensis exhibits unique adaptive mechanisms under NP-induced stress, offering the potential for controlled NP applications in biotechnology. Future research should further explore the relationship between nanoparticle types and cyanobacterial responses to optimize biomolecule production.

Unraveling Potential Causative Components for the Deleterious Effect of Atmospheric Fine Particulate Matter on Red Blood Cells.

Atmospheric fine particulate matter (PM2.5) poses threats to the cardiovascular system. Red blood cells (RBCs) are the most abundant cells in blood, which are actively involved in multiple hematological diseases, such as blood clot formation and thrombosis. Exploring how PM2.5 with spatiotemporal heterogeneity influences the hematological system by targeting RBCs would help gain insights into the deleterious effects of PM2.5 and provide clues for finding the causative components therein. Herein, the PM2.5 samples collected from 3 urban sites in Beijing (i.e., Chaoyang, Shunyi, and Yanqing districts) during 4 seasons of 2022 were studied for their toxicities to mouse RBCs, and the main contributing components were further explored through chemical analysis and correlation measure. The results showed that exposure to PM2.5 samples decreased adenosine triphosphate (ATP) levels and increased phosphatidylserine (PS) externalization of RBCs, causing cell morphological deformity. The Pearson correlation analysis showed that the aromaticity of the dissolved organic matter (DOM) in PM2.5 samples was positively correlated with PS exposure of RBCs, showing that the lignin-like compounds were the potential contributors. The negative correlation of zeta potentials of PM2.5 samples with PS exposure of RBCs showed the particle-derived bioactivities of this airborne pollutant. The simulative test based on artificial nanomaterials of carbon black (CB) and oxidized CB (OCB) confirmed the crucial role of particulate carbon in PM2.5-induced effects on RBCs, and soot with a certain oxidation degree was, thus, recognized as another contributor, given its ubiquitous existence in PM2.5 samples. This study, for the first time, revealed PM2.5-induced PS exposure of RBCs, and the causative components of DOM and soot were unraveled. Considering the inevitable contact of airborne PM2.5 with RBCs in the blood circulatory system, the findings obtained herein would help bridge the gap between PM2.5 exposure and the risk of cardiovascular diseases, like thrombogenesis.

Controlling COVID-19 outbreaks in the correctional setting: A mathematical modelling study.

Correctional centres (termed here 'prisons') are at high risk of COVID-19 and have featured major outbreaks worldwide. Inevitable close contacts, frequent inmate movements, and a disproportionate burden of co-morbidities mean these environments need to be prioritised in any public health response to respiratory pathogens such as COVID-19. We developed an individual-based SARS-CoV-2 transmission model for the prison system in New South Wales, Australia - incorporating all 33 correctional centres, 13,458 inmates, 578 healthcare and 6,909 custodial staff. Potential COVID-19 disease outbreaks were assessed under various mitigation strategies, including quarantine on entry, isolation of cases, rapid antigen testing of staff, as well as immunisation.Without control measures, the model projected a peak of 472 new infections daily by day 35 across the prison system, with all inmates infected by day 120. The most effective individual mitigation strategies were high immunisation coverage and prompt lockdown of centres with infected inmates which reduced outbreak size by 62-73%. Other than immunisation, the combination of quarantine of inmates at entry, isolation of proven or suspected cases, and widespread use of personal protective equipment by staff and inmates was the most effective strategy. High immunisation coverage mitigates the spread of COVID-19 within and between correctional settings but is insufficient alone. Maintaining quarantine and isolation, along with high immunisation levels, will allow correctional systems to function with a low risk of outbreaks. These results have informed public health policy for respiratory pathogens in Australian correctional systems.

Combined exposure to polyvinyl chloride and polystyrene microplastics induces liver injury and perturbs gut microbial and serum metabolic homeostasis in mice

A variety of microplastics (MPs) have become ubiquitous environmental pollutants, leading to inevitable human contact and health impacts. Most previous research has explored the toxic effects of a single type of MPs exposure. However, the effects of co-exposure to both common types of MPs, polyvinyl chloride (PVC) and polystyrene (PS) MPs on mammals have not been explored. Here, adult mice were exposed to PS-PVC (1.0 µm PS and 2.0 µm PVC both at the concentration of 0.5 mg/day) for 60 days. The results showed that PS-PVC co-exposure-induced hepatotoxicity was evidenced by liver histopathological changes, the release of inflammatory cytokines, and the activation of oxidative stress. Moreover, the intestinal mucosal barrier was damaged after PS-PVC treatment. The results of 16S rRNA gene sequencing reported there was a marked shift in the gut microbial structure accompanied by decreased relative abundances of probiotics, such as Clostridium, Lachnospiraceae_UCG-006, Desulfovibrio, Clostridiales_unclassified and Ruminococcaceae_unclassified and increased the conditional pathogen abundances, such as Erysipelatoclostridium. Furthermore, the triglyceride (TG) and total cholesterol (TCH) expression levels in the serum and liver were increased after PS-PVC co-exposure. Serum metabolomics analysis showed that there were 717 differential expression metabolites found in the positive- and negative-ion modes, including 476 up-regulated and 241 down-regulated, mainly enriched in butyrate metabolism, thiamine metabolism, and phenylacetate metabolism. In addition, remarked changes in the gut microbiota and serum metabolic profiles were closely related to hepatic and intestinal injuries after PS-PVC co-exposure. These results have provided new insights into the toxic effects of PS and PVC MPs co-exposure through the gut-liver axis and the health risks of PS and PVC MPs should be paid more attention to humans.

Flow and mass transfer prediction in anisotropic TPMS-structures as extracorporeal oxygenator membranes using reduced order modeling

Currently, hollow fiber membranes are the standard technology for extracorporeal membrane oxygenators. Apart from the inevitable contact of the circulating blood with the artificial material, a suboptimal flow distribution within the oxygenator favors thrombus formation which leads to a rapid loss of gas exchange capacity. The current advancement in additive manufacturing allows the design of three-dimensional membrane-structures, based on triply periodic minimal surfaces (TPMS). One of their unique advantages is local geometry variation to manipulate the flow distribution. But how this anisotropy influences the overall device performance is non-trivial and requires numerical simulation. The aim of this study was to develop a reduced order model (ROM) that is able to efficiently predict three-dimensional flow distribution and gas transfer inside TPMS-structures. We performed a parametric study using a validated micro scale computational fluid dynamics (CFD) model. Afterwards, two different modeling approaches of Sherwood-correlations and artificial neural networks (NN) were compared to characterize flow and mass transfer from the simulated data. To create the ROM, the NN modeling strategy was then implemented into a porous medium CFD model. The developed ROM was also validated. Finally, an anisotropic TPMS-membrane-structure was compared numerically with an isotropic predicate. The NN fitting strategy showed superior accuracy over the Sherwood-correlations for characterizing mass transfer in TPMS-structures. With the ROM, the gas transfer rates of oxygen and carbon dioxide from the micro CFD model could be predicted within relative root mean squared errors (RRMSE) of 2.7% and 5.1%. The pressure drop in the experiments was predicted with an RRMSE accuracy of 7.6%. In comparison with the isotropic TPMS-structure, the anisotropic structure showed a homogenized flow distribution and increased gas transfer rates of 4% to 5% for oxygen and 2.3% to 7.4% for carbon dioxide at the simulated flow rates.

Flow-induced alignment of titanium dioxide nanorods in polyolefin tubes for use in catheters

Interventional catheters are the pivotal components of catheter-assisted intervention therapy. However, the inevitable contact and friction between catheters and complex human channels usually lead to severe patient burdens. A fabrication strategy for variable-stiffness catheters based on time-dependent helical flow was developed by regulating the alignment of titanium dioxide (TiO2) nanorods in polyolefin elastomer (POE) catheters. In particular, the uniaxial and off-axial alignments of the TiO2 nanorods were manipulated to adjust the mechanical properties of each section in the POE catheters, where the processing flow pattern was transformed from axial to helical. To achieve the desired performance in practical applications, two catheters with a programmable helix angle of embedded TiO2 nanorods along the axial direction were designed. Correspondingly, the as-designed catheters displayed remarkably reduced interventional loads (e.g., a maximum reduction of 49.3% and 39.7% in single- and multi-curvature channels, respectively) and an enhancement of 50% in rotation synchronization, indicating promising potential for application in catheter-assisted interventional therapy. This study proposes an effective structuring design strategy for composed catheters with variable-stiffness segments that can be extended to all interventional catheter production techniques.

Tracing the plasma kallikrein-kinin system-activating component in the atmospheric particulate matter with different origins

Atmospheric particulate matter (PM) perturbs hematological homeostasis by targeting the plasma kallikrein-kinin system (KKS), causing a cascade of zymogen activation events. However, the causative components involved in PM-induced hematological effects are largely unknown. Herein, the standard reference materials (SRMs) of atmospheric PM, including emissions from the diesel (2975), urban (1648a), and bituminous coal (2693), were screened for their effects on plasma KKS activation, and the effective constituent contributing to PM-induced KKS activation was further explored by fraction isolation and chemical analysis. The effects of three SRMs on KKS activation followed the order of 2975 > 1648a > 2693, wherein the fractions of 2975 isolated by acetone and water, together with the insoluble particulate residues, exerted significant perturbations in the hematological homeostasis. The soot contents in the SRMs and corresponding isolated fractions matched well with their hematological effects, and the KKS activation could be dependent on the soot surface oxidation degree. This study, for the first time, uncovered the soot content in atmospheric PM with different origins contributed to the distinct effects on plasma KKS activation. The finding would be of utmost importance for the health risk assessment on inhaled airborne fine PM, given its inevitable contact with human circulatory system.

On the dynamics and control of a squirrel locking its head/eyes toward a fixed spot for safe landing while its body is tumbling in air.

An arboreal mammal such as a squirrel can amazingly lock its head (and thus eyes) toward a fixed spot for safe landing while its body is tumbling in air after unexpectedly being thrown into air. Such an impressive ability of body motion control of squirrels has been shown in a recent YouTube video, which has amazed public with over 100 million views. In the video, a squirrel attracted to food crawled onto an ejection device and was unknowingly ejected into air by the device. During the resulting projectile flight, the squirrel managed to quickly turn its head (eyes) toward and then keeps staring at the landing spot until it safely landed on feet. Understanding the underline dynamics and how the squirrel does this behavior can inspire robotics researchers to develop bio-inspired control strategies for challenging robotic operations such as hopping/jumping robots operating in an unstructured environment. To study this problem, we implemented a 2D multibody dynamics model, which simulated the dynamic motion behavior of the main body segments of a squirrel in a vertical motion plane. The inevitable physical contact between the body segments is also modeled and simulated. Then, we introduced two motion control methods aiming at locking the body representing the head of the squirrel toward a globally fixed spot while the other body segments of the squirrel were undergoing a general 2D rotation and translation. One of the control methods is a conventional proportional-derivative (PD) controller, and the other is a reinforcement learning (RL)-based controller. Our simulation-based experiment shows that both controllers can achieve the intended control goal, quickly turning and then locking the head toward a globally fixed spot under any feasible initial motion conditions. In comparison, the RL-based method is more robust against random noise in sensor data and also more robust under unexpected initial conditions.

Enhanced Performance of Monolithic Chalcogenide Thermoelectric Modules for Energy Harvesting via Co-optimization of Experiment and Simulation.

With the development of application of wireless sensor nodes (WSNs), the need for energy harvesting is rapidly increasing. In this study, we designed and fabricated a robust monolithic thermoelectric generator (TEG) using a simple, low-energy, and low-cost device fabrication process. Our monolithic device consists of Ag2S0.2Se0.8 and Bi0.5Sb1.5Te3 as n-type and p-type legs, respectively, while the empty space between the legs was filled with highly dense, flexible, and thin Ag2S that serves as both an insulating spacer and a shock absorber, which potentially augments the robustness of preventing from damage from an external mechanical force. From the optimization of the device structure via finite element method (FEM) simulations, a three-pair device with dimensions of 12 mm × 10 mm × 10 mm was found to have a theoretical maximum power density of 8.2 mW cm-2 at a ΔT of 50 K. For considering this inevitable contact resistance, experimental measurement and FEM simulation were combined for quantifying the junction resistance; a power density of 2.1 mW cm-2 was established with the consideration of the contact resistance at the p-n junctions. Using these optimized structural parameters, a device was fabricated and was found to have a maximum power density of 2.02 mW cm-2 at a ΔT of 50 K, which is in good agreement with our simulations. The results from our monolithic TEG show that despite the simple, low-energy, and low-cost device fabrication process, the power generation is still comparable to other reported TEGs. It is worth mentioning that our design could be extended to other chalcogenide materials of appropriate temperature regions and/or better zT. Besides, the quantification of contact resistance also exhibited reference value for the enhancement of thermoelectric conversion application. These results provide a convenient, economic, and efficient strategy for waste energy harvesting close to room temperature, which can broaden the applications of waste heat harvesting.

Influence of early drop bouncing on heat transfer during drop impact

Reducing the contact time with the water drop during impact has attracted much attention as a way to minimize the thermal interaction with water. Although various types of superhydrophobic surfaces have been developed for contact time reduction, few works investigated the actual heat transfer when the contact time is reduced. Here, by using all metallic superhydrophobic surfaces, we experimentally study the influence of pancake-like early bouncing on the change of surface temperature during drop impact. First, we propose the design criteria for early bouncing on mesh surfaces as a function of a mesh geometry and an impact velocity. Then, the thermal interaction during drop impact is quantified by recording the maximum temperature drop on the surfaces when the cold water drop is impinged onto the surface. The results show that the heat transfer is reduced on all tested mesh surfaces over the flat superhydrophobic plate, but unexpectedly the temperature change is not correlated with the contact time reduction. We propose that the inevitable contact area increase associated with early bouncing can counterbalance the effect of contact time reduction, which highlights the importance of the consideration of both contact time and contact area for heat transfer during drop impact.

Identifying behavior of long-distance virus transmission and mitigation performance from a COVID-19 outbreak of a daycare center

During the last two years, hundreds of millions of people in the world have been infected with SARS-CoV-2 due to recurrent waves and closed spaces. Daycare centers are critical infrastructures that cannot be replaced, even during the COVID-19 period. However, the existing settings in daycare centers may pose risks of inevitable close contact between teachers and children, as well as fomite and airborne transmission during care hours. Therefore, reinforced mitigation strategies have been applied in daycare centers to reduce potential indoor virus transfer in many countries. However, numerous outbreaks of COVID-19 have been reported in daycare centers. Therefore, in this study, researchers focused on the risk and behavior of long-distance virus transmission based on the detected viruses on air purifier filter sampling in a daycare center outbreak in Korea. Various experiments of possible situations were conducted in nursing rooms based on field interviews. The experiments monitored the long-distance transmission behavior of aerosol-sized particles and visualized particle behavior at the daycare center. The results of this study revealed that long-distance virus transmission is possible under the current settings in the daycare center, and flush-out can be an important countermeasure with reinforced ventilation methods to prevent potential airborne spread in the daycare center. The results of air purifiers represented that air purifiers should be properly installed and operated in the daycare center to prevent airborne virus spread by airflow during occupied hours. The findings of this study will contribute to the understanding of airborne virus risk and the development of customized virus measures for daycare centers.

Chemically induced alteration in PAC characteristics and its influences on PAC/UF water treatment: Implications for on-line membrane cleaning with NaClO

The integrated PAC/UF technique has gained increasing applications in water treatment systems. However, the fouling and substantial PAC deposition on membrane surfaces remain perennial hurdles. To tackle these issues, on-line membrane cleaning with NaClO should be frequently performed to sustain the membrane permeability, leading to the inevitable contact between NaClO and PAC particles, which may significantly change the PAC properties, hence the entire performance of water treatment during the next round of operation. This study simulated the two reactions between PACs and NaClO (i.e. deposited PAC with high-concentration NaClO and suspended PAC with low-concentration NaClO) based on the current practice of on-line membrane cleaning, and further investigated the impacts of NaClO-induced PAC variations on PAC/UF performance. The results showed that (i) the adsorption capacities of altered PACs for humic acid (HA), bovine serum albumin (BSA) as well as contaminants in surface water were seriously weakened because of the decreased specific surface area and pore volume; (ii) The altered PAC surface became more hydrophilic, presumably leading to the higher deposition on membrane surface. Besides, (iii) the PAC deposition amounts were all enhanced by the presence of BSA, while substantially decreased by HA. Further addition of Ca2+ with HA dramatically increased PAC deposition probably by forming the cross-linked molecular chains to connect PAC-PAC or PAC-membrane. As a result, membrane fouling in PAC/UF water treatment system was remarkedly aggravated when the altered PACs were applied due to NaClO exposure. Meanwhile, the surface water treatment performances in terms of CODMn removal, UV254 removal and turbidity removal significantly decreased, implying the adverse impacts of employing such altered PAC in the practical water treatment system. Given on-line chemical cleaning is frequently conducted during a long-term operation, the current study raised serious concerns on membrane cleaning induced PAC variations and potentially negative influences on the real-life PAC/UF water treatment process.

Different perspectives of doctors and nurses about the continuation of usage of some of the protection measures after the end of the COVID-19 pandemic

Abstract The current pandemic pointed toward a revision of the protection measures against infectious diseases. For any given new pathogen against which human species showed no immunity, isolation and personal protection equipment proved to reduce disease transmission. In medical settings, when there is inevitable contact with infected patients, these preventive measures have undoubtedly change the process of care delivery. The study aims to investigate the opinion of the healthcare workers about the utilization of the personal protective equipment after the pandemic stops. For this purpose, we conducted an online survey about changes related to the COVID-19 pandemic. For the healthcare workers, the survey also included several questions related to personal protective equipment. A total of 512 responders, doctors, and nurses answered to the survey. We performed comparisons between these two categories of personnel using the χ test. Overall, the results show that doctors are keener to follow the recommendations for the personal protective equipment in the future; there was a statistically significant difference (p<0.001) for the usage of gloves and masks while examining febrile patients, and for the handwashing after the examination of each patient. The type of service (outpatient or inpatient procedures) and direct contact with a COVID-19 patient were other factors to modulate the responses regarding using personal protective equipment in the future. The fact that 14.06% of the responders did not consider it necessary to wash hands after examining each patient underlines the urgent need for safety education in all healthcare workers and nurses.

A Wavy-Structured Highly Stretchable Thermoelectric Generator with Stable Energy Output and Self-Rescuing Capability

A Wavy-Structured Highly Stretchable Thermoelectric Generator with Stable Energy Output and Self-Rescuing Capability

A stretchable, harsh condition-resistant and ambient-stable hydrogel and its applications in triboelectric nanogenerator

During practical applications, energy harvesting devices such as TENGs always face complex harsh environment such as acidic, alkaline, and saline conditions. Even if the whole device (at least the electrode of the device) was protected by encapsulated approach, an inevitable contact between the electrode and the external harsh environment by the possible slight leakage would still cause seriously damage to the electrode materials. Consequently, it's of great significance to develop durable TENG materials that could be anticorrosive and harsh environmental resistant under a wide range of extreme conditions. In this work, a chemically robust and ultra-durable hydrogel (Cyc-hydrogel) was prepared by a self-polymerization reaction under room temperature. When we use the Cyc-hydrogel as the electrode of TENGs pretreated by extremely harsh conditions such as strong acidic, alkaline, and high concentration of saline solutions, respectively, the corresponding TENG's output performances could be kept relatively stable. Furthermore, even pretreated by simulated seawater which contained a high salinity, the resultant Cyc-hydrogel can still ensure a relatively stable electrical output performance when serving as the electrode of the TENGs. Our as-prepared hydrogel suggested great potentials for TENGs’ electrode material because of the inevitable slight leakage of the encapsulation device. • A chemically robust and ultra-durable hydrogel was prepared. • The TENG's output performances could be kept unaffected after the Cyc-hydrogel underwent strong acidic, alkaline, and saline solutions treatments. • The TENG's output performances could be kept stable after the Cyc-hydrogel underwent simulated seawater treatment.

USING MACHINE VISION FOR FUNCTIONALITY EXPANSION OF MINI ROBOTS DECONTAMINATING MEDICAL PERSONNEL PREMISES IN CONDITIONS OF COVID-19 EPIDEMIC

Abstract. In case of COVID-19 epidemic spread the requirements for protection of medical personnel were increased. This category of specialists has exposure of high risk of COVID-19, due to inevitable numerous contacts with infected persons.Because of this, existing practicable models of medical care are needed to be upgraded (Tavakoli, 2020). The emergency response path was implemented through the opening of new infectious hospitals, re-profiling clinics, as well as increasing workload on medical personnel. This approach is associated with the possible rapid drop-up of qualified medical specialists due to the illness, which is a strong limiting factor to respond to new threats of COVID-19 due to the risks of exhaustion of the human resource. In the worst scenario, a threat of collapse of the emergency and specialized medical care system due to peak load of severe patients under the shortage of doctors and support personnel. To prevent such an emergency, a complex of anti-epidemic events is provided, most of the purpose of interrupting infection contacts, isolation of the most vulnerable contingents, extended population testing for virus or contact with infected persons, this allows you to follow unwanted contacts with the subsequent mobility limitation.Digital monitoring technologies with digitization of incoming data of significant events played the increasing role in all these options. Today they are complemented by robotic supporting. Due to the high risk of the infection in the COVID-19 spread, including the intra-clinic infections, the requirements for reliable disinfection of closed premises intended for patients and medical personnel should be fulfilled. At the same time, the following circumstance should be taken into account. When these work-time activities are imposed on the employee who is forced to stay long in an infected air environment, he is subjected to additional impact of pathogenes. To reduce these threats, robotic support for the work for disinfection of premises with automated air environment control and tracing contacts.

Hemodynamic Assessment of Hollow-Fiber Membrane Oxygenators Using Computational Fluid Dynamics in Heterogeneous Membrane Models.

Extracorporeal membrane oxygenation (ECMO) has been used clinically for more than 40 years as a bridge to transplantation, with hollow-fiber membrane (HFM) oxygenators gaining in popularity due to their high gas transfer and low flow resistance. In spite of the technological advances in ECMO devices, the inevitable contact of the perfused blood with the polymer hollow-fiber gas-exchange membrane, and the subsequent thrombus formation, limits their clinical usage to only 2-4 weeks. In addition, the inhomogeneous flow in the device can further enhance thrombus formation and limit gas-transport efficiency. Endothelialization of the blood contacting surfaces of ECMO devices offers a potential solution to their inherent thrombogenicity. However, abnormal shear stresses and inhomogeneous blood flow might affect the function and activation status of the seeded endothelial cells (ECs). In this study, the blood flow through two HFM oxygenators, including the commercially available iLA® MiniLung Petite Novalung (Xenios AG, Germany) and an experimental one for the rat animal model, was modeled using computational fluid dynamics (CFD), with a view to assessing the magnitude and distribution of the wall shear stress (WSS) on the hollow fibers and flow fields in the oxygenators. This work demonstrated significant inhomogeneity in the flow dynamics of both oxygenators, with regions of high hollow-fiber WSS and regions of stagnant flow, implying a variable flow-induced stimulation on seeded ECs and possible EC activation and damage in a biohybrid oxygenator setting.

Adhesion Enhancement of Micropillar Array by Combining the Adhesive Design from Gecko and Tree Frog.

It has long been demonstrated the gecko-inspired micropillar array with T-shape tips possesses the best adhesion performance of a given material. The further enhancement of the adhesion performances of T-shape micropillars can offer redundant adhesion to compensate for the inevitable improper contacts. Here, the array of T-shape polydimethylsiloxane (PDMS) micropillars is incorporated with gradient dispersed calcium carbonate nanoparticles in the micropillar stalk, termed as T-shape gradient micropillars (TG), possessing the modulus gradient with stiff tip and soft root. The gradient modulus in TG facilitates the contact formation and regulates the stress at the detaching interface, resulting in a 4.6 times adhesion and 2.4 times friction as compared with the pure PDMS T-shape micropillar arrays. The study here provides a new design strategy for the super-strong structured dry adhesives.

The utilization of rapid serological tests in COVID-19 diagnostics - a high risk of false-negative results in outpatient care, with particular emphasis on dental treatment.

In order to mitigate the spread of COVID-19, in the early stages of the pandemic outbreak, postponing elective procedures was recommended all around the world. Outpatient care and dental care were limited to telephone advice and emergency services. Dental staff is particularly vulnerable to SARS-CoV-2 contraction, because of the inevitable contact with patients' body fluids during aerosol-generating procedures. The implementation of diagnostic tests among ambulatory patients could improve the occupational safety among outpatient care personnel. The aim of this review was to introduce information regarding COVID-19 diagnostics with a particular focus on the methods which can be utilized in an outpatient and dental care setting. An online PubMed database review of articles on COVID-19 diagnostics, published on February 12-May 15, 2020, was conducted. Reverse transcription polymerase chain reaction is the gold standard in COVID-19 diagnostics, which determines if a person has an active infection. Unfortunately, its utilization in outpatient care is limited. Serological enzyme-linked immunosorbent assays identify people who were infected, including those who have had an asymptomatic infection, but they do not give sufficient information about the acute infection. Rapid serological assays developed to facilitate testing outside of laboratories, especially in dental offices, are not recommended by the World Health Organization to be used outside research settings, and they should not constitute the basis for clinical decision-making because of frequent false-negative results which may consequently contribute to personnel infections. Out of all available COVID-19 diagnostic methods, rapid serological assays seemed to be a method of choice in outpatient medical care. Unfortunately, their results turned out to be unreliable. The best methods to ensure the occupational safety of medical staff and to avoid cross-infections in outpatient care facilities include a thorough epidemiological interview, temperature measurement to rule out patients with an active infection, and the implementation of strict infection control procedures. Med Pr. 2021;72(2):155-62.

The Other in Science Fiction as a Problem for Social Theory

The paper discusses science fiction literature in its relation to some aspects of the socio-anthropological problem, such as the representation of the Other. Given the diversity of sci-fi genres, a researcher always deals either with the direct representation of the Other (a creature different from an existing human being), or with its indirect, mediated form when the Other, in the original sense of this term, is revealed to the reader or viewer through the optics of some Other World. The article describes two modes of representing the Other by sci-fi literature, conventionally designated as scientist and anti-anthropic. The scientist rep-resentation constructs exclusively-rational premises for the relationship with the Other. Edmund Hus-serl’s concept of truth, which is the same for humans, non-humans, angels, and gods, can be considered as its historical and philosophical correlate. The anti-anthropic representation, which is more attractive to sci-fi authors, has its origins in the experience of the “disenchantment” of the world characteristic of mod-ern man, especially in the tragic feeling of incommensurability of a finite human existence and the infinity of the cosmic abysses. The historical and philosophical correlate of this anti-anthropic representation can be found in Kant’s teaching of a priori cognition forms, which may be different for other thinking beings. The model of an attitude to the Other therefore cannot be based on rational foundations. As a literary ex-ample where these two ways of representing the Other are found, we propose the analysis of The Martian Chronicles by Ray Bradbury, which, on the one hand, offers the fictional extrapolation of the colonization of North America and the inevitable contacts with its indigenous population. On the other hand, The Martian Chronicles depicts a powerful and technologically advanced Martian civilization, which disap-pears for some unknown reason, or ceases to contact the settlers. The combination of these two ways of representing the Other allows Bradbury to effectively romanticize and mystify the unique historical experience of colonization, thus modifying the Frontier myth.