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Materials (Basel, Switzerland) May 2024When dealing with processes involving the compaction of bulk materials, very often the quality of the product is determined based on density measurements. Methods used...
When dealing with processes involving the compaction of bulk materials, very often the quality of the product is determined based on density measurements. Methods used in the industry do not produce compacted materials with high degrees of homogeneity. As a result, the quality of the resulting product, interpreted as its density, varies over the cross-section of the product. In this article, the authors present the results of a numerical study involving the analysis of the density distribution of compacted dry ice during the reciprocating process. The Drucker-Prager/cap model was used in this study, which allowed the change in mechanical properties of the compacted material to be taken into account during the simulation of the process. The diameter, height and density of the cylindrical specimens used in the numerical tests were taken as the variable parameters. Thus, as a result of the testing, the authors could formulate conclusions relating to their impact on the homogeneity of the material.
PubMed: 38893921
DOI: 10.3390/ma17112658 -
International Journal of Molecular... May 2024In the last few years, several studies have emphasized the existence of injury-specific EV "barcodes" that could have significant importance for the precise diagnosis of...
In the last few years, several studies have emphasized the existence of injury-specific EV "barcodes" that could have significant importance for the precise diagnosis of different organ injuries in polytrauma patients. To expand the research potential of the NTF (network trauma research) biobank of polytraumatized patients, the NTF research group decided to further establish a biobank for EVs. However, until now, the protocols for the isolation, characterization, and storage of EVs for biobank purposes have not been conceptualized. Plasma and serum samples from healthy volunteers (n = 10) were used. Three EV isolation methods of high relevance for the work with patients' samples (ultracentrifugation, size exclusion chromatography, and immune magnetic bead-based isolation) were compared. EVs were quantified using nanoparticle tracking analysis, EV proteins, and miRNAs. The effects of different isolation solutions; the long storage of samples (up to 3 years); and the sensibility of EVs to serial freezing-thawing cycles and different storage conditions (RT, 4/-20/-80 °C, dry ice) were evaluated. The SEC isolation method was considered the most suitable for EV biobanking. We did not find any difference in the quantity of EVs between serum and plasma-EVs. The importance of particle-free PBS as an isolation solution was confirmed. Plasma that has been frozen for a long time can also be used as a source of EVs. Serial freezing-thawing cycles were found to affect the mean size of EVs but not their amount. The storage of EV samples for 5 days on dry ice significantly reduced the EV protein concentration.
Topics: Humans; Extracellular Vesicles; Biological Specimen Banks; Multiple Trauma; Specimen Handling; Chromatography, Gel; Male; Ultracentrifugation; MicroRNAs; Adult; Female
PubMed: 38891833
DOI: 10.3390/ijms25115645 -
Langmuir : the ACS Journal of Surfaces... Jun 2024In this work, we study the relationship between the molecular water layer (MWL) and frost freezing onset and propagation. The progression of frost has been reported to...
In this work, we study the relationship between the molecular water layer (MWL) and frost freezing onset and propagation. The progression of frost has been reported to be governed by various localized icing phenomena, including interdroplet ice bridging, dry zones, and frost halos. Reports studying the state of water on surfaces have revealed the presence of a thin nanometer water layer on a range of surfaces. Regardless of further investigations that show environmental humidity, temperature, and surface energy to affect the thickness of the MWL on surfaces, the influence of the MWL on frost nucleation and propagation has not yet been previously addressed in the literature. To study the effect of the MWL on surface freezing events, a range of surface-functionalized glass substrates were prepared. In situ monitoring of freezing events with thermal imaging allowed studying the effect of surface chemistry and environmental relative humidity (RH) on the thickness and continuity of the MWL. We argue that the observed icing nucleation and propagation kinetics are directly related to the presence and continuity of the MWL, which can be manipulated by controlling the environmental humidity and surface chemistry.
PubMed: 38872416
DOI: 10.1021/acs.langmuir.4c00323 -
The Science of the Total Environment Sep 2024The Tibetan Plateau (TP) is one of the most challenging areas for human long-term settlement due to its extreme living environment. Understanding the relationship...
The Tibetan Plateau (TP) is one of the most challenging areas for human long-term settlement due to its extreme living environment. Understanding the relationship between human activities and environmental changes in this extreme environment is important and can provide a historical reference for adapting to future climate change. In this study, we took the Angren Basin in the southern TP as a case study to elucidate the relationship since Little Ice Age (LIA). Using fecal stanol in feces, lake and river surface sediments, surface soils, and sediment core, we found that specific indices S1 and S2 from the composition of coprostanol, epicoprostanol, 5β-ethylcoprostanol and 5β-ethylepicoprostanol can reflect changes in human population and herbivores, respectively. Through the comparison between environmental changes determined by grain size, elements, sedimentation rate, and other climate records, the relationship between human activities and environmental changes was interpreted. Our results indicate that: (i) during 1480-1820 CE, the fecal stanols in lake sediments mainly originated from livestock, and the human population was low. In contrast, during 1820-2021 CE, the proportion and flux of S1 have been continuously increasing, indicating significant population growth. (ii) During the middle LIA, the cold-dry climate inhibited the development of agriculture and farming. However, the increased precipitation during the late LIA promoted that development, resulting in an increase in human population and livestock in a short term. (iii) Since 1951, people have reclaimed wasteland and developed husbandry, leading to increased soil erosion. (iv) Over the past 40 years, with a warm-humid climate and good policy support, human activities, such as agriculture and husbandry, have rapidly increased, but soil erosion has declined in the recent 20 years due to good soil-water conservation efforts. This study sheds light on the relationship between human activities and environmental changes and provides insights into future climate change responses.
Topics: Tibet; Climate Change; Humans; Human Activities; Environmental Monitoring; Lakes; Geologic Sediments; Feces; Soil
PubMed: 38857808
DOI: 10.1016/j.scitotenv.2024.173741 -
Acta Tropica Jun 2024Mosquito-borne diseases constitute a significant global impact on public and animal health. Climatic variables are recognized as major drivers in the mosquitoes' life...
Mosquito-borne diseases constitute a significant global impact on public and animal health. Climatic variables are recognized as major drivers in the mosquitoes' life history, principally rainfall and temperature, which directly influence mosquito abundance. Likewise, urbanization changes environmental conditions, and understanding how environmental variables and urbanization influence mosquito dynamics is crucial for the integrated management of mosquito-borne diseases, especially in the context of climate change. In this study, our aim was to observe the effect of temperature, rainfall, and the percentage of impervious surface on the abundance of mosquito species over a temporal scale of one complete year of fortnightly samplings, spanning from June 2021 to June 2022 in Yucatan, Mexico. We selected nine localities along an urbanization gradient (three natural, three rural, and three urban) from Mérida City to Reserva de la Biosfera Ría Celestún. Using BG-traps, mosquitoes were collected biweekly at each locality. Additionally, we estimated the percentage of impervious surface. Daily data of the maximum, mean and minimum temperatures, diurnal temperature range and rainfall were accumulated weekly. We calculated the accumulated quantities of temperatures and rainfall and lagged from one to four weeks before sampling for each locality. Generalized linear mixed models were then performed to study the influence of environmental variables and percentage of impervious surfaces on each of the 15 most abundant species. A total of 131,525 mosquitoes belonging to 11 genera and 49 species were sampled with BG-Sentinel traps baited with BG-lure and dry ice. The most frequently significative variable is the accumulated precipitation four weeks before the sampling. We observed a positive relationship between Cx. quinquefasciatus and Cx. thriambus with the diurnal temperature range. For Ae. aegypti, we observed a positive relationship with minimum temperature. Conversely, the percentage of impervious surface serves as a proxy of anthropogenic influence and helped us to distinguishing species exhibiting habitat preference for urban and rural environments, versus those preferring natural habitats. Our results characterize the species-specific effects of environmental variables (temperature, rainfall and impervious surface) on mosquito abundance.
PubMed: 38851624
DOI: 10.1016/j.actatropica.2024.107275 -
Food Chemistry May 2024This study evaluated four ELISA kits for quantitation of milk proteins in thermally treated milk samples and food products. How reference materials may be used for...
This study evaluated four ELISA kits for quantitation of milk proteins in thermally treated milk samples and food products. How reference materials may be used for comparison of kit performance was examined. Protein contents determined by Veratox Total Milk generally reflected those determined by the 660 nm total protein assay. BioKits BLG Kit was less affected by thermal treatment but resulted in overestimation of protein contents in samples that were boiled, autoclaved or dry-heated at ≤149 °C, while ELISA Systems Casein (ES Casein) and Beta-Lactoglobulin (ES BLG) assays underestimated protein levels in these samples. The four kits gave similar results for ice cream. Veratox registered higher concentrations in all products tested but its sensitivity was greatly lowered in retorted products. ES Casein underperformed Veratox for baked and retorted products. BioKits BLG maintained a better sensitivity towards fried, baked and retorted products while ES BLG exhibited reduced sensitivity for these products.
PubMed: 38823126
DOI: 10.1016/j.foodchem.2024.139736 -
The Science of the Total Environment Aug 2024Due to extreme weather events and deforestation the physical and chemical characteristics of watersheds in mountain areas could exceed the known variations. Therefore,...
Due to extreme weather events and deforestation the physical and chemical characteristics of watersheds in mountain areas could exceed the known variations. Therefore, the spring water of the Innerste river in the Western Harz Mountains (Germany) was monitored from 2020 to 2023. The monitoring approach is simple and can be directly transferred to other watersheds of springs which are connected to the meteoric water cycle. The specific electrical conductivity (SEC) of the water is compared to daily precipitation data. The SEC values range between 50 and 100 μS/cm. In September 2020 and July 2022 the spring dried out. A hysteretic relationship between spring runoff and spring water mineralisation was found. The SEC values of the spring water are rising during dry periods or in winter seasons with a long ice cover in the catchment area. The highest SEC values are typical for long dry periods and flush events after the drying out of the spring. The relationship of SEC and major ions of the spring water (especially bicarbonate) indicates that biogeochemical processes within the soil zone and water-rock interactions in fractured shales and greywackes of the catchment area control the chemical composition of the spring water. Comparing the obtained results with data measured before the first observed drying out of the spring, no unexpected new values and correlations of runoff, SEC values and ion concentrations were found.
PubMed: 38810740
DOI: 10.1016/j.scitotenv.2024.173565 -
Scientific Reports May 2024Robust chronologies and time equivalent tephra markers are essential to better understand spatial palaeoenvironmental response to past abrupt climatic changes....
Robust chronologies and time equivalent tephra markers are essential to better understand spatial palaeoenvironmental response to past abrupt climatic changes. Identification of well-dated and widely dispersed volcanic ash by tephra and cryptotephra (microscopic volcanic ash) provides time synchronous tie-points and strongly reduces chronological uncertainties. Here, we present the major, minor and trace element analyses of cryptotephra shards in the Dead Sea Deep Drilling sedimentary record (DSDDP 5017-1A) matching the Campanian Ignimbrite (CI). This geochemical identification expands the known dispersal range of the CI to the southeastern Mediterranean, over 2300 km from the volcanic source. Due to the CI eruption occurring near-synchronous with North Atlantic ice surge of Heinrich Event 4 (HE4), this tephra provides insights into regional responses to large-scale climatic change in the Mediterranean. In the Dead Sea, the CI layer is associated with wetter climatic conditions. This contrasts with the contemporaneous occurrence of the CI deposition and dry conditions in the central and eastern Mediterranean suggesting a possible climate time-transgressive expansion of HE4. Our finding underscores the temporal and spatial complexity of regional climate responses and emphasises the importance of tephra as a time marker for studying large-scale climatic changes verses regional variations.
PubMed: 38802380
DOI: 10.1038/s41598-024-59639-7 -
Journal of Perianesthesia Nursing :... May 2024This study aimed to determine the effect of menthol ice application on thirst, dry mouth, mouth taste, and bad mouth odor in patients who underwent laparoscopic...
PURPOSE
This study aimed to determine the effect of menthol ice application on thirst, dry mouth, mouth taste, and bad mouth odor in patients who underwent laparoscopic cholecystectomy in the postoperative period.
DESIGN
The study was conducted as a randomized controlled trial with an experimental design.
METHODS
The study sample consisted of 90 patients who underwent laparoscopic cholecystectomy and met the inclusion criteria. Patients were divided into three groups by randomization program. Patients in the menthol ice and ice popsicle (ice prepared with drinking water only) group were administered menthol ice/ice popsicle (10 mL) twice at 20 minutes intervals. Patients in the control group did not receive any intervention. Routine practices of the clinic were performed by the nurses of the general surgery clinic. Postoperative thirst intensity, severity of dry mouth, bad taste, and bad odor in the mouth were evaluated at 0, 20, and 40 minutes.
FINDINGS
No statistically significant difference was found between the sociodemographic and clinical characteristics of the patients in the control group, menthol ice group, and ice popsicle group (P > .05). A statistically significant difference was found between the 3 groups in terms of thirst intensity and severity of dry mouth at times at the 20th and 40th minutes after the application (P < .01). We found a statistically significant difference between the bad taste and bad odor sensation scores of the patients in the control and intervention groups at the 20th and 40th minutes after the application (P < .05).
CONCLUSIONS
The study concluded that menthol ice and ice popsicle application are effective strategies to reduce the intensity of thirst, severity of dry mouth, bad taste, and bad odor in postoperative patients.
PubMed: 38795086
DOI: 10.1016/j.jopan.2023.12.024 -
Materials (Basel, Switzerland) May 2024The developments in manufacturing technologies are expected to reduce energy input without compromising product quality. Regarding the material densification process,...
The developments in manufacturing technologies are expected to reduce energy input without compromising product quality. Regarding the material densification process, numerical simulation methods are applied to achieve this goal. In this case, relevant material models are built using functions that describe the variation in mechanical parameters of the material in question due to its deformation. The literature review conducted for this research has revealed a shortage of experimental research methods allowing a determination of the coefficient of friction at low temperatures, approximately 200 K. This article proposes a method for determining the friction coefficient of dry ice sliding against steel. The experimental results were analysed to obtain several functions describing the variation in the coefficient of friction. These functions were then compared using goodness-of-fit indexes. Finally, two functions with similar goodness-of-fit values were chosen. The findings of this research project will complement the already available information and may be used in various research and implementation projects related to the development or improvement of currently used crystallised carbon dioxide conversion processes.
PubMed: 38793463
DOI: 10.3390/ma17102396