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Polymers May 2024In the present study, tests were carried out on composite samples on a polylactide matrix containing 25% by weight of mineral filler in the form of diatomaceous earth,...
In the present study, tests were carried out on composite samples on a polylactide matrix containing 25% by weight of mineral filler in the form of diatomaceous earth, base, and silanized with GPTMOS (3-glycidoxypropyltrimethoxysilane), OTES (n-octyltriethoxysilane), and MTMOS (methyltrimethoxysilane) silanes. The addition of two types of waxes, synthetic polyamide wax and natural beeswax, were used as a factor to increase the rheological properties of the composites. The obtained samples were characterized in terms of the effect of filler silanization on the degradation rate of the composites. The tests were conducted under different conditioning conditions, i.e., after exposure to strong UV radiation for 250 and 500 h, and under natural sunlight for 21 days. The conditioning carried out under natural conditions showed that the modified samples exhibit up to twice the degradation rate of pure polylactide. The addition of synthetic wax to the composites increases the tendency to agglomerate diatomaceous earth, while natural wax has a positive effect on filler dispersion. For composites modified with GPTMOS and OTES silanes, it was noted that the addition of natural wax inhibited the degree of surface degradation, compared to the addition of synthetic wax, while the addition of MTMOS silane caused the opposite effect and samples with natural wax degraded more strongly. It was shown that, despite the high degree of surface degradation, the process does not occur significantly deep into the composite and stops at a certain depth.
PubMed: 38891398
DOI: 10.3390/polym16111450 -
Small (Weinheim An Der Bergstrasse,... Jun 2024Lithium-sulfur (Li-S) batteries are expected to be the next-generation energy storage system due to the ultrahigh theoretical energy density and low cost. However, the...
Lithium-sulfur (Li-S) batteries are expected to be the next-generation energy storage system due to the ultrahigh theoretical energy density and low cost. However, the notorious shuttle effect of higher-order polysulfides and the uncontrollable lithium dendrite growth are the two biggest challenges for commercially viable Li-S batteries. Herein, these two main challenges are solved by in situ polymerization of bi-functional gel polymer electrolyte (GPE). The initiator (SiCl) not only drives the polymerization of 1,3-dioxolane (DOL) but also induces the construction of a hybrid solid electrolyte interphase (SEI) with inorganic-rich compositions on the Li anode. In addition, diatomaceous earth (DE) is added and anchored in the GPE to obtain PDOL-SiCl-DE electrolyte through in situ polymerization. Combined with density functional theory (DFT) calculations, the hybrid SEI provides abundant adsorption sites for the deposition of Li, inhibiting the growth of lithium dendrites. Meanwhile, the shuttle effect is greatly alleviated due to the strong adsorption capacity of DE toward lithium polysulfides. Therefore, the Li/Li symmetric cell and Li-S full cell assembled with PDOL-SiCl-DE exhibit excellent cycling stability. This study offers a valuable reference for the development of high performance and safe Li-S batteries.
PubMed: 38888118
DOI: 10.1002/smll.202402862 -
International Journal of Pharmaceutics Jun 2024The development of Levonorgestrel Intrauterine Systems (LNG-IUSs) stands as a formidable challenge due to their intricate design and reliance on specialized...
The development of Levonorgestrel Intrauterine Systems (LNG-IUSs) stands as a formidable challenge due to their intricate design and reliance on specialized manufacturing methods. Pharmaceutical manufacturers face a labyrinth of process variables that demand precise identification and comprehension to establish a robust product design to ensure consistent performance. The current manuscript navigates through this complexity, describing a small-scale processing method for LNG-IUSs via addition and condensation curing processes, as well as investigating the influence of key manufacturing variables on LNG-IUS product performance. Different mixing speeds and time exhibited distinct impact on drug content uniformity within the IUS drug-polymer reservoirs. Surprisingly, no variation in drug release rates were observed. Curing temperature and time were the critical processing parameters of IUSs which were dependent on the polymer type (polydimethylsiloxane, PDMS) and drug loading. At lower curing temperatures, crosslinking in PDMS remained relatively unaffected, irrespective of drug loading. By contrast, elevating curing temperatures resulted in a drastic reduction in PDMS crosslinking densities at higher drug loading. This was attributed to increased drug volume fraction within the matrix, impeding optimal prepolymer chain mobility and rearrangement which is crucial for complete crosslinking. Interestingly, rapid curing led to increased PDMS crystallinity, thereby retarding drug release rates while concurrently compromising mechanical properties. PDMS curing chemistry, such as condensation cure (no filler) and addition cure (cured at room temperature), did not affect drug release rates of the LNG-IUSs. In the condensation cure-based LNG-IUS, the formulations prepared without filler had higher drug release rates than those containing silica or diatomaceous earth fillers. Overall, the present study unravels the intricate interplay between PDMS characteristics, processing variables, and product performance, offering fundamental insights into product design and manufacturing of brand and generic LNG-IUS products.
PubMed: 38880254
DOI: 10.1016/j.ijpharm.2024.124343 -
Pest Management Science Jun 2024Over the past two decades, bed bugs (Cimex spp.) have resurged as common urban pests around the world. The search for efficient and safe control measures has become a...
BACKGROUND
Over the past two decades, bed bugs (Cimex spp.) have resurged as common urban pests around the world. The search for efficient and safe control measures has become a key interest among researchers, manufacturers, and pest control professionals. In this study, we evaluated and compared the efficacy of steam, diatomaceous earth (DE) dust, and a combination of both against tropical bed bugs (Cimex hemipterus (F.)) under laboratory and field conditions.
RESULTS
In the laboratory study, the mortality of bed bugs after 2 days of exposure to DE dust was 100%. When bed bugs stayed on the surface of an object or in cracks, a brief steam treatment (1 s) caused 100% mortality. However, when bed bugs were hidden under a fabric cover, steam application for 10 s only caused 89 ± 6% mortality. Bed bugs that survived steam treatment exhibited reduced feeding activity. In a 14-week long study, there was no significant difference in the reduction rate of bed bugs between steam treatment and DE dust treatment. A 37-week long control study showed that steam and steam plus DE dust treatments eliminated 97-100% of the infestations.
CONCLUSION
Applying steam and DE dust are effective strategies for eliminating natural tropical bed bug infestations. Continuous follow-up monitoring and treatment until no bed bugs are found are crucial in completely eliminating the infestation of tropical bed bugs. © 2024 Society of Chemical Industry.
PubMed: 38847149
DOI: 10.1002/ps.8227 -
Journal of Materials Chemistry. B Jun 2024Rapid and sensitive detection of food-borne bacteria has remained challenging over the past few decades. We propose a surface-enhanced Raman scattering sensing strategy...
Rapid and sensitive detection of food-borne bacteria has remained challenging over the past few decades. We propose a surface-enhanced Raman scattering sensing strategy based on a novel bioinspired surface-enhanced Raman scattering substrate, which can directly detect dye molecular residues and food-borne pathogen microorganisms in the environment. The surface-enhanced Raman scattering platform consists of a natural diatomite microporous array decorated with a metal-phenolic network that enables the reduction of gold nanoparticles. The as-prepared nanocomposites display excellent surface-enhanced Raman scattering activity with the lowest limit of detection and the maximum Raman enhancement factor of dye molecules up to 10 M and 1.18 × 10, respectively. For food-borne bacterial detection, a diatomite microporous array decorated with a metal polyphenol network and gold nanoparticle-based surface-enhanced Raman scattering analysis is capable of distinguishing the biochemical fingerprint information of and , indicating the great potential for strain identification.
Topics: Spectrum Analysis, Raman; Staphylococcus aureus; Diatomaceous Earth; Escherichia coli; Gold; Metal Nanoparticles; Food Microbiology; Surface Properties; Particle Size
PubMed: 38809058
DOI: 10.1039/d4tb00488d -
Biomaterials Advances Jul 2024Engineering of scaffolds for bone regeneration is often inspired by the native extracellular matrix mimicking its composite fibrous structure. In the present study, we...
Engineering of scaffolds for bone regeneration is often inspired by the native extracellular matrix mimicking its composite fibrous structure. In the present study, we used low loadings of diatomite earth (DE) biosilica to improve the bone regeneration potential of gelatin electrospun fibrillar microenvironments. We explored the effect of increasing the DE content from 1 % to 3 % and 5 %, respectively, on the physico-chemical properties of the fibrous scaffolds denoted FG_DE1, FG_DE3, FG_DE5, regarding the aqueous media affinity, stability under simulated physiological conditions, morphology characteristics, and local mechanical properties at the surface. The presence of biosilica generated composite structures with lower swelling degrees and higher stiffness when compared to gelatin fibers. Increasing DE content led to higher Young modulus, while the stability of the protein matrix in PBS, at 37 °C, over 21 was significantly decreased by the presence of diatomite loadings. The best preosteoblast response was obtained for FG_DE3, with enhanced mineralization during the osteogenic differentiation when compared to the control sample without diatomite. 5 % DE in FG_DE5 proved to negatively influence cells' metabolic activity and morphology. Hence, the obtained composite microfibrillar scaffolds might find application as osteoblast-responsive materials for bone tissue engineering.
Topics: Gelatin; Osteoblasts; Tissue Scaffolds; Tissue Engineering; Animals; Diatomaceous Earth; Osteogenesis; Cell Differentiation; Mice; Bone Regeneration; Cell Line; Cellular Microenvironment; Microfibrils; Extracellular Matrix
PubMed: 38796956
DOI: 10.1016/j.bioadv.2024.213894 -
Insects Apr 2024We evaluated the persistence and efficacy of two different, in granulometry and content of diatoms, diatomaceous earth (DE) formulations (i.e., DE5 and DE6), against two...
We evaluated the persistence and efficacy of two different, in granulometry and content of diatoms, diatomaceous earth (DE) formulations (i.e., DE5 and DE6), against two major beetle species of stored products, i.e., (L.) (Coleoptera: Curculionidae) and (F.) (Coleoptera: Bostrychidae). The formulations were applied as powders in soft wheat and maize in two doses of 500 and 1000 mg kg (ppm). Samples of the treated grains were taken on the day of application and every 30 days until completion of the six-month period of storage. Adults of and were exposed to the treated grains at 25 °C and 55% relative humidity, and the mortality was measured after 7, 14, and 21 days of exposure. survival was not affected by any combination of DE formulation, dose, and commodity. Contrariwise, the DEs caused significant adult mortality of , in most of the cases tested. We observed that DE6 was equally effective in both wheat and maize, and no considerable variations were observed in mortality during the 6-month experimental period. Furthermore, DE6 was more effective against than DE5, a difference that could have potentially contributed to the variations in the diatom granulometry between these two DEs. Thus, a DE treatment of 1000 ppm was shown to provide long-term protection of wheat and maize against , but this is strongly dependent on the DE formulation, commodity, and insect species. Overall, such natural resource-based inert silicaceous deposits could be used with success in stored-product protection with only some minor modifications, such as sieving and drying of the raw deposit.
PubMed: 38786875
DOI: 10.3390/insects15050319 -
Frontiers in Veterinary Science 2024is a bacterial pathogen capable of causing serious disease in humans and abortions in goats. Infected goats can shed . through urine, feces, and parturient byproducts,...
is a bacterial pathogen capable of causing serious disease in humans and abortions in goats. Infected goats can shed . through urine, feces, and parturient byproducts, which can lead to infections in humans when the bacteria are inhaled. Goats are important . reservoirs as evidenced by goat-related outbreaks across the world. To better understand the current landscape of . infection in the domestic goat population, 4,121 vaginal swabs from 388 operations across the United States were analyzed for the presence of . by IS1111 PCR as part of the United States Department of Agriculture, Animal Plant Health Inspection Service, Veterinary Services' National Animal Health Monitoring System Goats 2019 Study. In total, 1.5% (61/4121) of swabs representing 10.3% (40/388) (weighted estimate of 7.8, 95% CI 4.4-13.5) of operations were positive for . DNA. The quantity of . on positive swabs was low with an average Ct of 37.9. Factors associated with greater odds of testing positive included suspected Q fever in the herd in the previous 3 years, the presence of wild deer or elk on the operation, and the utilization of hormones for estrus synchronization. Factors associated with reduced odds of testing positive include the presence of kittens and treatment of herds with high tannin concentrate plants, diatomaceous earth, and tetrahydropyrimidines. analysis demonstrated an inhibitory effect of the tetrahydropyrimidine, pyrantel pamoate, on the growth of . in axenic media as low as 1 μg per mL. The final multivariable logistic regression modeling identified the presence of wild predators on the operation or adjacent property (OR = 9.0, 95% CI 1.3-61.6, value = 0.0248) as a risk factor for . infection.
PubMed: 38774910
DOI: 10.3389/fvets.2024.1393296 -
Vector Borne and Zoonotic Diseases... May 2024Tick-borne diseases are an emerging threat to public health throughout the temperate world, leading to a growing field of research aimed at developing and testing...
Tick-borne diseases are an emerging threat to public health throughout the temperate world, leading to a growing field of research aimed at developing and testing intervention strategies for reducing human-tick encounters or prevalence of infection in ticks. Various wide-spectrum chemical acaricides have proven effective for controlling tick populations, but many of these have potential deleterious side-effects on health and the environment. In addition to chemical acaricides, certain compounds such as diatomaceous earth have been shown to have physical acaricidal properties. We hypothesized that dolomitic lime (CaMg(CO), a corrosive, desiccant mineral that is already used extensively in agricultural and forestry contexts to balance the pH of soils, may affect ticks' locomotory activity, habitat position, or survival and that this should manifest as a reduction in the number of questing ticks collected by dragging. This study aimed to formally assess this hypothesis in a controlled laboratory setting. We carried out a microcosm experiment, with one control and three treated microcosm trays, each replicating the natural substrate characterizing habitat in northeastern North America. Each tray was infested with 200 living larvae and 50 nymphs, and then treated with 0 (control), 50, 100, or 500 g/m of lime powder. Ticks were collected by microdragging 24 and 72 h postliming. Efficacy of liming at reducing the number of collected questing ticks ranged from 87% to 100% for larvae and 0% to 69% for nymphs 24 h postliming and from 91% to 93% for larvae and -47% to 65% for nymphs 72 postliming. This study provides the first experimental evidence of the potential efficacy of liming for impairing activity of questing immature ticks. Given that lime is a low-cost material, that methods for widespread application in deciduous woodlands already exist, and that it has been documented as having a limited negative impact on the environment, further assessment of lime application as a public health risk reduction intervention for tick-borne diseases is warranted.
PubMed: 38770710
DOI: 10.1089/vbz.2023.0158 -
ACS Omega May 2024Efficient hydrogen storage is essential for its use as a sustainable energy carrier. Diatomaceous earth, a high-surface-area siliceous geomaterial, shows potential as a...
Efficient hydrogen storage is essential for its use as a sustainable energy carrier. Diatomaceous earth, a high-surface-area siliceous geomaterial, shows potential as a physisorption material for hydrogen storage. This study analyzes diatomaceous earth's long-term characteristics when subjected to high-pressure hydrogen injection. The diatomaceous earth was subjected to a hydrogen pressure of 1200 psi for a period of 80 days at room temperature. Neither notable morphological or mineralogical changes were observed. Nevertheless, there was a slight reduction in fine particles and a slight increase in larger particles. The Brunauer-Emmett-Teller (BET) surface area decreased slightly with a significant decrease in pore width. However, the hydrogen adsorption at 77 K temperature was increased significantly (45.5%) after the hydrogen storage test. Moreover, there was a delayed release of molecular water as the temperature increased. These changes suggest that a condensation reaction has occurred involving some of the opal-A silanol groups (Si-O-H), producing molecular water. Bonding through siloxane bridges (Si-O-Si) results in a significant decrease in pore width and increased hydrophobicity (i.e., the interaction between diatomaceous surface and H was increased), thereby enhancing hydrogen adsorption capacity. These findings indicate that diatomaceous earth holds promise as a material for hydrogen storage, with the potential for its hydrogen adsorption capacity to improve over time.
PubMed: 38764626
DOI: 10.1021/acsomega.4c02415