Graphene Nanoplatelets: In Vivo and In Vitro Toxicity, Cell Proliferative Activity, and Cell Gene Expression

Multi-layer graphene (2–10 layers), also called graphene nanoplatelets (GNPs), is a carbon-based nanomaterial (CBN) type with excellent properties desirable for many biomedical applications. Despite the promising advantages reported of GNPs, nanoscale materials may also present a potential hazard to humans. Therefore, in this study, the in vivo toxicity of these nanomaterials at a wide range of concentrations from 12.5 to 500 µg/mL was evaluated in the Caenorhabditis elegans model for 24 h (acute toxicity) and 72 h (chronic toxicity). Furthermore, their in vitro toxicity (from 0 to 10 µg/mL for 12 and 24 h), proliferative activity at 72 and 96 h, and their effect on the expression of thirteen genes in human keratinocytes HaCaT cells were studied. The physico-chemical and morphological aspects of the GNPs used in this study were analyzed by Raman scattering spectroscopy, electron microscopy, zeta potential as a function of pH, and particle size measurements by dynamic light scattering. The results of this study showed that GNPs showed in vivo non-toxic concentrations of 25 and 12.5 µg/mL for 24 h, and at 12.5 µg/mL for 72 h. Moreover, GNPs present time-dependent cytotoxicity (EC50 of 1.142 µg/mL and 0.760 µg/mL at 12 h and 24 h, respectively) and significant proliferative activity at the non-toxic concentrations of 0.005 and 0.01 μg/mL in the HaCaT cell line. The gene expression study showed that this multi-layer-graphene is capable of up-regulating six of the thirteen genes of human keratinocytes (SOD1, CAT, TGFB1, FN1, CDH1, and FBN), two more genes than other CBNs in their oxidized form such as multi-layer graphene oxide. Therefore, all these results reinforce the promising use of these CBNs in biomedical fields such as wound healing and skin tissue engineering.

Results of the complex evaluation of bryndza cheese and the byproduct milk whey with the use of enzyme MTG and its activity degree during storage

The paper examines the question of using the enzyme microbial transglutaminase (mTG) for bryndza cheese production. Microbial transglutaminase belongs to the enzyme family that catalyzes formation of bonds between amino groups. One of the problems in production of high-protein products, in particular, cheeses from goat milk is flabbiness of the clot. The use of mTG in the technological process would allow strengthening the product protein matrix, thereby improving its commercial characteristics. When performing the histological investigation of cheeses with this enzyme type to characterize the state of the protein matrix, the authors established that the product protein structure was more condensed compared to the control samples (without mTG), which affected cheese consistency. Consistency became more rubbery negatively influencing the product sensory properties, which are important traits for a consumer when buying a product. Using a Brookfield texture analyzer, it was shown that structural-mechanical characteristics were improved by 1.5 times for cheese samples produced from cow milk and by 2 times for goat cheese when mTG was used. Analysis of the enzyme catalytic activity showed that this enzyme retained its activity throughout the whole storage period, which is a potential hazard for human health. After shelf-life expiration, a change in the mTG activity was not more than 5% relative to the initial levels. The enzyme activity retained not only in cheese but also in the by-product — cheese whey, which made its processing more difficult.

High-density metals and arsenic in algae of storm emissions from the coastal area of the Severny island of the Novaya Zemlya archipelago

Purpose of the Study is to assess the potential hazard in terms of the content of high-density metals (HDMs) and arsenic (As) for the consumption of objects of the Arctic algal flora presented in storm emissions in places of probable disembarkation of a crew, the ship has come in a distress or a disaster in the water area of the northern seas of the Russian Federation.Materials and methods. The elemental composition of samples of the plants thrown by the wind-wave impact on the coastal area of the Severny island of the Novaya Zemlya archipelago. Before making the analysis, thallus fragments were dried at 80° C to constant weight to determine their dry weight with an accuracy of 1 mg. The material mineralization was carried out using a microwave mineralizer according to the standard technique. The elementary analysis was performed using MGA-915M atomic spectrometer. The data obtained were compared with the maximum permissible levels established by the current regulatory documents. According to the results of measurements, series of decreasing concentrations of HDMs in algae samples were built according to the places of collection and species.Results and Discussion. It has been found that the lowest content of HDMs and arsenic in the wind-wave emissions of algae on the Severny Island in the Russkaya Gavan Bay of the Novaya Zemlya archipelago belongs to both Laminaria digitata and vegetative parts of the thallus of most of the other ejected algae. These plants can be used for food in extreme situations by the crews of a ship (an aircraft, etc.) who has come in a distress or a disaster.

Assessing potential hazard of technogenic formations of natural and man-made complexes of some sulphide deposits of the Eastern Zabaykalye

The analysis of chemical composition of technosol and soil samples from Akatuyevsky and Blagodatsky polymetallic deposit mines of the Eastern Zabaykalye revealed that the main pollutant in the soil samples is As. Material excess of the Maximum allowable concentrations was registered for Pb, Zn, Cd and Mn. Calculation of potential hazard coefficients showed that the most hazardous for the environment are man-made formations of Akatuyevsky and Blagodatsky mines. Of all the chemical elements which are most commonly encountered at the Akatuyevsky and Blagodatsky mines technosol the most hazardous are As, Pb, Zn and Cu. It is noted that these chemical elements are part of sulphide ore minerals.

“Attention! A Door Could Open.”—Introducing Awareness Messages for Cyclists to Safely Evade Potential Hazards

Numerous statistics show that cyclists are often involved in road traffic accidents, often with serious outcomes. One potential hazard of cycling, especially in cities, is “dooring”—passing parked vehicles that still have occupants inside. These occupants could open the vehicle door unexpectedly in the cyclist’s path—requiring a quick evasive response by the cyclist to avoid a collision. Dooring can be very poorly anticipated; as a possible solution, we propose in this work a system that notifies the cyclist of opening doors based on a networked intelligent transportation infrastructure. In a user study with a bicycle simulator (N = 24), we examined the effects of three user interface designs compared to a baseline (no notifications) on cycling behavior (speed and lateral position), perceived safety, and ease of use. Awareness messages (either visual message, visual message + auditory icon, or visual + voice message) were displayed on a smart bicycle helmet at different times before passing a parked, still-occupied vehicle. Our participants found the notifications of potential hazards very easy to understand and appealing and felt that the alerts could help them navigate traffic more safely. Those concepts that (additionally) used auditory icons or voice messages were preferred. In addition, the lateral distance increased significantly when a potentially opening door was indicated. In these situations, cyclists were able to safely pass the parked vehicle without braking. In summary, we are convinced that notification systems, such as the one presented here, are an important component for increasing road safety, especially for vulnerable road users.

Etiology, presentation and treatment of ocular trauma in paediatric population.

Objective: To determine the etiology, presentation and treatment of ocular trauma in paediatric population. Study Design: Cross Sectional Study. Setting: Institute of Ophthalmology, Liaquat University Hospital Jamshoro. Period: January, 2020 to December 2020. Material & Methods: Data was collected using a questionnaire having age, sex, cause of injury and time at presentation to the emergency. It also focused on which structures were damaged due to injury, investigations being used, and treatment performed. Results: In our study we found 80 cases of ocular trauma in pediatric population visiting the ophthalmology department. Gender distribution of the study group which includes 72.5% (n=58) males and 27.5% (n=22) females. It was found during playing 86.3% of children had ocular trauma followed by injury due to domestic stuff like glass, bleach cleaners in 7.5% of the study group. The most frequently occurring ocular trauma was found to be corneal tear occurring in 25% of the study group. Conclusion: Ocular trauma in children can be prevented by simple measures like supervising children and educating parents and teachers for potential hazard substances. It is important to address like healthcare issue as ocular trauma can lead to lifelong blindness along with psychological and financial burden for the caretaker and children themselves.

Wind Shear of Low-Level Jets and Their Influence on Manned and Unmanned Fixed-Wing Aircraft during Landing Approach

Wind shear at low altitudes represents a potential hazard to landing aircraft. Based on two wind lidar data sets of one year, the occurrence of low-level jets (LLJs), the vertical wind shear and the rotation of the wind direction were analysed. The lidar system was located at the sites of Braunschweig in the North German Plain, Germany, and Clausthal-Zellerfeld in the low mountain range Harz, Germany. The observed wind shear gradients between the altitude of 40 m and the altitude of the maximum wind speed was in the range of −0.23 s−1 to +0.20 s−1. The rotation of the wind direction with altitude occurred both in clockwise and anticlockwise direction. The ratio of clockwise versus anticlockwise occurrence of directional shear was 4:1 for Braunschweig and 3:1 for Clausthal-Zellerfeld. The observed wind shear gradients were compared to values for hazard potential of different levels for a typical aircraft. Although the LLJ was not hazardous for manned aircraft in any observed case, the awareness of LLJ helps to reduce the pilot’s workload and possible pilot-introduced oscillations caused as a result of the wind shear and aircraft characteristics. In contrast to manned aviation, the value of changes in wind speed and direction during LLJ conditions can cause significant risks for unmanned aerial system operations with less than 25 kg of take-off weight. This is a result of the lower airspeed-wind-speed ratio and the flight control and flight planning.

Automated Image Analysis to Map the Extent of Deep-Sea Mining Plumes Reveals a Larger Impacted Area Compared to Manual Analysis

Deep sea mining for poly-metallic nodules impacts the environment in many ways. A key potential hazard is the creation of a sediment plume from resuspending sediment during seabed mining. The resuspended matter disperses with currents but eventually resettles on the seabed. Resettling causes a blanketing of the seafloor environment, potentially causing harm to in-, epi- and hyperbenthic communities with possible cascading effects into food webs of deep sea habitats. Mapping the extent of such blanketing is thus an important factor in quantifying potential impacts of deep-sea mining.One technology that can assess seabed blanketing is optical imaging with cameras at square-kilometre scale. To efficiently analyse the resulting Terabytes of image data with minimized bias, automated image analysis is required. Moreover, effective quantitative monitoring of the blanketing requires ground truthing of the image data. Here, we present results from a camera-based monitoring of a deep-sea mining simulation combined with automated image analysis using the CoMoNoD method and low-cost seabed sediment traps for quantification of the blanketing thickness. We found that the impacted area was about 50 percent larger than previously determined by manual image annotation.

The Functional Impact of Home-based Self-rehabilitation Following Arthroscopic Root Repair

Purpose: COVID-19 pandemic makes outdoors rehabilitation a potential hazard. Patient education to perform simple home-based exercises seems to be an interesting and sometimes a mandatory option. This study provides a comparison between the conventional and home-based virtual rehabilitation after surgical repair of medial meniscus root tears. Methods: All patients who underwent MPRT repair with a modified trans-tibial pull-out technique from March 2019 to March 2021 were evaluated. Those who underwent surgery after December 2019 were trained to perform self-rehabilitation. The rest had undergone outdoors specialized rehabilitation according to a unified protocol and these were used as a historical control group. All patients were followed up for a minimum of 2 year after surgery. Final Lysholm scores were utilized to compare functional outcomes. Results: Forty-three consecutive patients with medial meniscal root tears were studied. Thirty-nine (90.7%) were women and 4 (9.3%) were men. The mean age of participants was 53.2 ±8.1 years. The total Lysholm knee score, and all its items were significantly improved in both groups at a two-year follow-up (p<0.05), except the “Using cane or crutches” item (p=0.065). Nevertheless, the final Lysholm knee score improvement was higher in patients who performed outdoors specialized rehabilitation and in patients with shorter time-to-surgery.Conclusion: Regardless of age and gender, home-based rehabilitation after meniscal root repair with the modified trans-tibial pull-out technique improved the patients’ function at a two-year follow-up. Nonetheless, this effect was still significantly lower than that of the outdoors specialized rehabilitation. Future work is required to clarify basic protocols for home-based tele-rehabilitation programs and determine clinical, radiological and functional results.Level of evidence: Level IV, therapeutic, historically controlled study