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Insects Mar 2022Ixodids (hard ticks), ectoparasitic arthropods that vector the causal agents of many serious diseases of humans, domestic animals, and wildlife, have become increasingly... (Review)
Review
Ixodids (hard ticks), ectoparasitic arthropods that vector the causal agents of many serious diseases of humans, domestic animals, and wildlife, have become increasingly difficult to control because of the development of resistance against commonly applied synthetic chemical-based acaricides. Resistance has prompted searches for alternative, nonconventional control tactics that can be used as part of integrated ixodid management strategies and for mitigating resistance to conventional acaricides. The quest for alternative control tactics has involved research on various techniques, each influenced by many factors, that have achieved different degrees of success. Alternative approaches include cultural practices, ingested and injected medications, biological control, animal- and plant-based substances, growth regulators, and inert desiccant dusts. Research on biological control of ixodids has mainly focused on predators, parasitoid wasps, infective nematodes, and pathogenic bacteria and fungi. Studies on animal-based substances have been relatively limited, but research on botanicals has been extensive, including whole plant, extract, and essential oil effects on ixodid mortality, behavior, and reproduction. The inert dusts kaolin, silica gel, perlite, and diatomaceous earth are lethal to ixodids, and they are impervious to environmental degradation, unlike chemical-based toxins, remaining effective until physically removed.
PubMed: 35323601
DOI: 10.3390/insects13030302 -
La Medicina Del Lavoro Jun 2020«Severe silicosis due to diatomaceous earth in dental alginate: a necropsy study»
UNLABELLED
«Severe silicosis due to diatomaceous earth in dental alginate: a necropsy study»
BACKGROUND:
METHODS:
A commercial sample of calcinated diatomaceous earth and necroscopic lung samples were analysed by scanning electron microscopy (SEM-EDS) and X-ray diffraction (XRD) for the quali-quantitative determination of crystalline silica. Material safety data sheets (MSDSs) of diatomaceous earth produced in 2002 and 2018 were examined to assess the information content on silicosis risk. Clinical findings and post-mortem examinations of the worker are evaluated.
RESULTS:
A cristobalite concentration of 36% (wt/wt) was determined in the diatomaceous earth sample and a large amount of diatom fragments were observed in lung samples. The DRX spectra indicated the presence of cristobalite either in the bulk sample or in the lung tissues. The MSDS dated 2002 reported the presence of SLC up to 63% with cristobalite concentrations <60%, and the resulting risk of silicosis, while the MSDS dated 2018 and referred to a commercial product currently on the market indicated a concentration of cristobalite <1% and no risk of silicosis. The worker was suffering from a severe silicosis, histologically confirmed by necropsy.
CONCLUSION:
The present case-study revealed that the risk of silicosis from calcined diatomaceous earths used to produce dental alginates has been ignored. The lack of engineering controls and personal protection measures led to a high cristobalite lung burden, consistent with the development of a severe silicosis that were a contributing factor of death. A MSDS of a commercial product currently on the market does not report this serious hazard.
Topics: Alginates; Diatomaceous Earth; Humans; Occupational Exposure; Silicon Dioxide; Silicosis
PubMed: 32624564
DOI: 10.23749/mdl.v111i3.9742 -
Materials (Basel, Switzerland) May 2022The fractionation of diatomaceous earth (DE) using sedimentation made it possible to obtain separate unbroken diatom fractions from broken or agglomerated bodies with a...
The fractionation of diatomaceous earth (DE) using sedimentation made it possible to obtain separate unbroken diatom fractions from broken or agglomerated bodies with a range of particle sizes. The produced filler was used to prepare polylactide (PLA)/diatomaceous earth biocomposite samples containing different particle sizes, which were subjected to mechanical testing (tensile strength, flexural strength, impact strength), colloidal testing (contact angle, color change test, SEM/EDS), and thermal testing (TGA, DSC, DMA). Modification of the PLA containing the smallest particle size with diatomaceous earth (Fraction 5) resulted in a higher impact strength compared to both the pure PLA and the PLA/DE composite that contained base diatomaceous earth. Furthermore, the melt flow rate was improved by more than 80 and 60% for the composite modified with fractionated diatomaceous earth (Fraction 4) compared to pure PLA and base diatomaceous earth, respectively. The elasticity of the composite was also improved from 3.3 GPa for pure polylactide to 4.4 GPa for the system containing the smallest diatomaceous earth particles (Fraction 5).
PubMed: 35629631
DOI: 10.3390/ma15103607 -
RSC Advances Sep 2021The present article overviews the current state-of-the-art and future prospects for the use of diatomaceous earth (DE) in the continuously expanding sector of energy... (Review)
Review
The present article overviews the current state-of-the-art and future prospects for the use of diatomaceous earth (DE) in the continuously expanding sector of energy science and technology. An eco-friendly direct source of silica and the production of silicon, diatomaceous earth possesses a desirable nano- to micro-structure that offers inherent advantages for optimum performance in existing and new applications in electrochemistry, catalysis, optoelectronics, and biomedical engineering. Silica, silicon and silicon-based materials have proven useful for energy harvesting and storage applications. However, they often encounter setbacks to their commercialization due to the limited capability for the production of materials possessing fascinating microstructures to deliver optimum performance. Despite many current research trends focusing on the means to create the required nano- to micro-structures, the high cost and complex, potentially environmentally harmful chemical synthesis techniques remain a considerable challenge. The present review examines the advances made using diatomaceous earth as a source of silica, silicon-based materials and templates for energy related applications. The main synthesis routes aimed at preserving the highly desirable naturally formed neat nanostructure of diatomaceous earth are assessed in this review that culminates with the discussion of recently developed pathways to achieving the best properties. The trend analysis establishes a clear roadmap for diatomaceous earth as a source material of choice for current and future energy applications.
PubMed: 35495528
DOI: 10.1039/d1ra05810j -
Journal of the Mechanical Behavior of... Sep 2022The effect of a natural filler (diatomaceous earth [DE], a promising drug-delivery agent) and its content was investigated on the performance of a model glass-ionomer...
The effect of a natural filler (diatomaceous earth [DE], a promising drug-delivery agent) and its content was investigated on the performance of a model glass-ionomer cement (GIC). Three sample series, differing in DE content (0, 2.5 and 5 wt%), were prepared using a commercial GIC as a matrix (3M Ketac Molar Easymix). The resultant surface microhardness and roughness, wear performance, and compressive strength of the samples were measured after the samples had been stored in deionized water at 37°C for a fixed time. Moreover, the film thickness was tested for the freshly mixed samples. The numerical data was subjected to statistical analysis, in order to test the null hypotheses of the equality of the measured properties between the reference and the DE-modified samples. According to the results, diatomaceous earth particles are uniformly distributed in the GIC matrix, and the cavities of frustules tend to be filled with the GIC. This translates into the observed performance of the DE-loaded GIC. Compared with the reference material (0 wt% DE), the surface microhardness (2.5 wt% DE, p = 0.014; 5 wt% DE, p = 0.005) and roughness (e.g. Ra; 2.5 wt% DE, p = 0.003; 5 wt% DE, p < 0.001) are increased. No effect on the wear performance (p = 0.530 and 0.256, respectively) or compressive strength (p = 0.514) was noticed in the case of DE partially substituting the glass phase. Based on the study results, it is evidenced that diatom frustules are a suitable filler for application in conventional glass-ionomer cements as the glass-substituting drug-loaded carrier. Notably, however, the surface finish method of the DE-filled materials needs development.
Topics: Compressive Strength; Diatomaceous Earth; Drug Carriers; Glass Ionomer Cements; Materials Testing
PubMed: 35738132
DOI: 10.1016/j.jmbbm.2022.105324 -
Materials (Basel, Switzerland) Oct 2022The presented research is focused on the complex assessment of three different types of diatomaceous earth and evaluation of their ability for application as pozzolana...
The presented research is focused on the complex assessment of three different types of diatomaceous earth and evaluation of their ability for application as pozzolana active admixtures applicable in the concrete industry and the production of repair mortars applicable for historical masonry. The comprehensive experimental campaign comprised chemical, mineralogical, microstructural, and physical testing of raw materials, followed by the analyses and characterization of pozzolanic activity, rheology and heat evolution of fresh blended pastes, and testing of macrostructural and mechanical parameters of the hardened 28-days and 90-days samples. The obtained results gave evidence of the different behavior of researched diatomaceous earth when mixed with water and Portland cement. The differences in heat evolution, initial and final setting time, porosity, density, and mechanical parameters were identified based on chemical and phase composition, particle size, specific surface, and morphology of diatomaceous particles. Nevertheless, the researched mineral admixtures yielded a high strength activity index (92.9% to 113.6%), evinced their pozzolanic activity. Three fundamental factors were identified that affect diatomaceous earth's contribution to the mechanical strength of cement blends. These are the filler effect, the pertinent acceleration of OPC hydration, and the pozzolanic reaction of diatomite with Portland cement hydrates. The optimum replacement level of ordinary Portland cement by diatomaceous earth to give maximum long-term strength enhancement is about 10 wt.%., but it might be further enhanced based on the properties of pozzolan.
PubMed: 36234222
DOI: 10.3390/ma15196881 -
Insects Sep 2020Diatomaceous earth (DE) has long been known as a potential protectant for stored cereals against various stored product insects. Despite favorable effect for the...
Diatomaceous earth (DE) has long been known as a potential protectant for stored cereals against various stored product insects. Despite favorable effect for the environment and human health, DE has some negative side effects on the treated commodity. In order to minimize negative response and to improve its efficacy, this paper represents a study of developed natural formulation based on DE SilicoSec enhanced with botanicals (essential oil lavender, corn oil, and bay leaves dust) and silica gel. The activity of formulation (labeled as N Form) was tested against (L.) (F.), and (Herbst) in seed wheat and barley under controlled conditions. As a reference comparative value, DE SilicoSec was used. N Form showed higher efficacy than DE, especially in barley at the lowest concentration, inducing higher mortality of all three insect species. The highest average progeny inhibition was recorded in population both in seed wheat and barley with 94.9% and 96.3% of inhibition, respectively, followed with and inhibition of 90.6% and 86.1%, respectively, in wheat and 94.9% and 89.7%, respectively, in barley. Results indicate that the developed natural formulation N Form enhanced the activity of DE SilicoSec using lower amount of DE dust and that it could be successfully implemented for storage of cereals as alternatives to chemical pesticides for stored product insect control.
PubMed: 32911831
DOI: 10.3390/insects11090613 -
International Journal of Molecular... Aug 2022A neoteric round sieve diatomite (De) decorated with sea-urchin-like alpha-type iron trioxide (α-FeO) synthetics was prepared by the hydrothermal method and further...
A neoteric round sieve diatomite (De) decorated with sea-urchin-like alpha-type iron trioxide (α-FeO) synthetics was prepared by the hydrothermal method and further calcination. The results of the electromagnetic (EM) parameters of α-FeO-decorated De (α-FeO@D) showed that the minimum reflection loss (RL) of α-FeO@D could reach -54.2 dB at 11.52 GHz and the matched absorber thickness was 3 mm. The frequency bandwidth corresponding to the microwave RL value below -20 dB was up to 8.24 GHz (9.76-18 GHz). This indicates that α-FeO@D composite can be a lightweight and stable material; because of the low density of De (1.9-2.3 g/cm), the density of α-FeO@D composite material is lower than that of α-FeO (5.18 g/cm). We found that the combination of the magnetic loss of sea-urchin-like α-FeO and the dielectric loss of De has the most dominant role in electromagnetic wave absorption and loss. We focused on comparing the absorbing properties before and after the formation of sea-urchin-like α-FeO and explain in detail the effects of the structure and crystal shape of this novel composite on the absorbing properties.
Topics: Diatomaceous Earth; Microwaves
PubMed: 36012621
DOI: 10.3390/ijms23169362 -
Molecules (Basel, Switzerland) Dec 2023Heparin, a highly sulfated glycosaminoglycan, is a naturally occurring anticoagulant that plays a vital role in various physiological processes. The remarkable...
Heparin, a highly sulfated glycosaminoglycan, is a naturally occurring anticoagulant that plays a vital role in various physiological processes. The remarkable structural complexity of heparin, consisting of repeating disaccharide units, makes it a crucial molecule for the development of commercial drugs in the pharmaceutical industry. Over the past few decades, significant progress has been made in the development of cost-effective adsorbents specifically designed for the adsorption of heparin from porcine intestinal mucosa. This advancement has been driven by the need for efficient and scalable methods to extract heparin from natural sources. In this study, we investigated the use of cationic ammonium-functionalized diatomaceous earth, featuring enhanced porosity, larger surface area, and higher thermal stability, to maximize the isolated heparin recovery. Our results showed that the higher cationic density and less bulky quaternary modified diatomaceous earth (QDADE) could adsorb up to 16.3 mg·g (31%) of heparin from the real mucosa samples. Additionally, we explored the conditions of the adsorbent surface for recovery of the heparin molecule and optimized various factors, such as temperature and pH, to optimize the heparin uptake. This is the introductory account of the implementation of modified diatomaceous earth with quaternary amines for heparin capture.
Topics: Animals; Swine; Diatomaceous Earth; Heparin; Anticoagulants; Temperature; Intestinal Mucosa
PubMed: 38138471
DOI: 10.3390/molecules28247982 -
Molecules (Basel, Switzerland) Dec 2021Nowadays, we are tackling various issues related to the overuse of synthetic insecticides. Growing concerns about biodiversity, animal and human welfare, and food... (Review)
Review
Nowadays, we are tackling various issues related to the overuse of synthetic insecticides. Growing concerns about biodiversity, animal and human welfare, and food security are pushing agriculture toward a more sustainable approach, and research is moving in this direction, looking for environmentally friendly alternatives to be adopted in Integrated Pest Management (IPM) protocols. In this regard, inert dusts, especially diatomaceous earths (DEs), hold a significant promise to prevent and control a wide range of arthropod pests. DEs are a type of naturally occurring soft siliceous sedimentary rock, consisting of the fossilized exoskeleton of unicellular algae, which are called diatoms. Mainly adopted for the control of stored product pests, DEs have found also their use against some household insects living in a dry environment, such as bed bugs, or insects of agricultural interest. In this article, we reported a comprehensive review of the use of DEs against different arthropod pest taxa, such as Acarina, Blattodea, Coleoptera, Diptera, Hemiptera, Hymenoptera, Ixodida, Lepidoptera, when applied either alone or in combination with other techniques. The mechanisms of action of DEs, their real-world applications, and challenges related to their adoption in IPM programs are critically reported.
Topics: Animals; Arthropods; Diatomaceous Earth; Insect Control; Insecticides
PubMed: 34946567
DOI: 10.3390/molecules26247487