The Use of Sulfur Waste to Protect Against Corrosion of Metal Implants

Metal parts of endoprosthesis have a detrimental effect on the bones that come into contact with them and on the entire body of the patient. Coating them with biocompatible layers (hydroxyapatite and bioglass) has not yet brought about permanent results. In this study, the author showed the possibility of using a binder containing sulfur waste for this purpose. The sulfur binder is used industrially in electrical engineering and construction applications. The chemical properties of elemental sulfur indicate that it is a biocompatible material. Previous studies on rats have shown that sulfur binder is a biocompatible material. A steel surgical nail covered with sulfur waste, placed in a sheep's femur, showed excellent stabilization by adhering bone tissue to the composite layer. From the results, it is convinced that the composite made of sulfur waste creates new possibilities in the field of production of biocomposites for surgical applications. The prepared biocomposite composition was sulfur waste-69.5%, mineral quartz dust-30%, and technical soot-0.5%. There is no information on similar studies in the world literature. So far, sulfur waste has been used in the electrical and construction industries. The literature shows that no researcher has used sulfur waste in biocomposites. So, the current study is a pioneering experimental study in this area.

Structural Construction of Binders Based on Orthophosphoric Acid and Refractory Materials

The formation of phosphate binders in systems based on orthophosphoric acid and the most common refractory fillers in foundry technology (quartz dust, zircon ZrSiO4, and kyanite-sillimanite Al2SiO5) has not been previously studied. The phase composition of these inorganic binders was studied, and the formation of silicon SiP2O7 and zirconium ZrP2O7 pyrophosphates was confirmed. The study by differential thermogravimetric analysis in the temperature range of 20–1000°С established the fact that the formed binders are thermally stable and do not emit harmful gaseous substances. The obtained results of the studied binders make it possible to develop new environment-friendly core mixtures of thermal hardening.

Cytotoxicity of fractured quartz on human macrophages: role of the membranolytic activity of quartz and phagolysosome destabilization.

Background The pathogenicity of quartz involves lysosomal alteration in alveolar macrophages. This event triggers the inflammatory cascade that may lead to quartz-induced silicosis and eventually lung cancer. Recently, we showed that synthetic quartz induces membrane lysis in red blood cells and cytotoxic responses in murine alveolar macrophages, only when the atomic order of crystal surfaces is upset by fracturing. Cytotoxicity was not observed when quartz exhibited as-grown, unfractured surfaces. These findings raised questions on the potential impact of quartz surfaces on the phagolysosomal membrane upon internalization of the particles by macrophages.Results To gain insights on the surface-induced cytotoxicity of quartz, as-grown and fractured quartz particles in respirable size, differing only in surface properties related to fracturing, were prepared and physico-chemically characterized. Their effects were compared to a well-known toxic commercial quartz dust. Membranolysis was assessed on red blood cells, and quartz uptake, cell viability, and impact on lysosomes were assessed on human PMA-differentiated THP-1 macrophages. All quartz samples were internalized, but only fractured quartz elicited cytotoxicity and phagolysosomal alterations. These effects were blunted when uptake was suppressed. Membranolysis, but not cytotoxicity, was quenched when fractured quartz surface was masked with serum proteins and incubated with cells.Conclusions Upon internalization, the phagolysosome environment rapidly removes serum proteins from quartz surface, restoring quartz membranolytic activity in the phagolysosomes. Fractured quartz induces cytotoxicity in THP-1 human macrophages by promoting phagolysosomal membrane alterations.

Quarzstaub in der Bauwirtschaft/Quartz dust in the construction industry

Mineralische Baustoffe sind nach wie vor die tragende Säule der Bauwirtschaft. Trotz aller Bemühungen und Fortschritte der letzten Jahre bleibt der Beurteilungsmaßstab für Quarzstaub für viele Gewerke der Bauwirtschaft in den nächsten Jahren eine Herausforderung. Dieser Beitrag zeigt beispielhaft Lösungen und Herausforderungen auf.

Effects of occupational exposure to respirable quartz dust on acute myocardial infarction

ObjectivesThe aim of this study is to investigate the effects of occupational exposure to respirable quartz (RQ) on first acute myocardial infarction (AMI). RQ causes pulmonary diseases like silicosis and has also been linked to cardiovascular diseases. Inflammation is hypothesised as the underlying pathway.MethodsWe performed a 1:3 matched case–control study nested in a cohort of male uranium miners. We included cases (identified from hospital records and validated according to WHO criteria) who had suffered their first AMI while still employed and <65 years of age. Controls were matched by date of birth and Wismut recruitment era. RQ exposure was derived from a job-exposure matrix. We performed a conditional logistic regression adjusted for smoking, metabolic syndrome and baseline erythrocyte sedimentation rate. Subgroups by date of birth and Wismut recruitment era were analysed to minimise the impact of pre-exposures.ResultsThe study base comprised 292 matched sets. The cumulative exposure ranged from 0 to 38.9 mg/m3-years RQ. The adjusted OR of the highest RQ tertile (>14.62 mg/m3-years) was 1.27 (95% CI 0.82 to 1.98). However, for miners born after 1928 and hired in the earliest recruitment era (1946–1954), a significantly elevated risk was seen in the highest RQ tertile (OR=6.47 [95% CI 1.33 to 31.5]; 50 matched sets).ConclusionsAn impact of quartz dust on first AMI was observed only in a small subgroup that had virtually no pre-exposure to RQ. Further studies on the basis of complete occupational history are required to substantiate this finding.

Quarzstaubbelastung und Silikosen in der Schweiz/Quartz dust exposure and silicoses in Switzerland

Im Zusammenhang mit der Revision des Grenzwerts für Quarzfeinstaub in verschiedenen Komitees weltweit untersuchte die Schweizerische Unfallversicherungsanstalt (Suva) die Belastung durch Quarzfeinstaub in der Schweiz. Der Median der von der Suva in den letzten 15 Jahren gemessenen Quarzfeinstaubwerte betrug 0,08 mg/m3 (n = 3 154). 26 % der Messwerte lagen über dem Schweizer MAK-Wert von 0,15 mg/m3 in der alveolengängigen Staubfraktion (a). Zwischen 2005 und 2014 hat die Suva 179 Silikosen als Berufskrankheit anerkannt. Die Hälfte der betroffenen Arbeiter war erstmals vor Einführung des aktuellen Schweizer MAK-Werts im Jahr 1975 gegenüber Quarzstaub exponiert. Zusätzlich zu den Silikosen traten acht Fälle von Lungenkrebs und 55 Fälle von chronisch-obstruktiven Atemwegserkrankungen (COPD, inkl. chronischer Bronchitis und Emphysem) als Zweitdiagnose auf. Gemäß unserer Analyse dürften die Lungenkrebsfälle am ehesten auf das Rauchen zurückzuführen sein. Auch bei der COPD ist die häufigste Ursache das Rauchen, eine Kausalitätsabklärung fand sich in den Dossiers jedoch kaum.

Nano-indentation of native phytoliths and dental tissues: implications for herbivore-plant combat and dental wear proxies

Tooth wear induced by abrasive particles is a key process affecting dental function and life expectancy in mammals. Abrasive particles may be plant endogenous opal phytoliths, exogene wind-blown quartz dust or rain borne mineral particles ingested by mammals. Nano-indentation hardness of abrasive particles and dental tissues is a significant yet not fully established parameter of this tribological system. We provide consistent nano-indentation hardness data for some of the major antagonists in the dental tribosystem (tooth enamel, tooth dentine and opaline phytoliths from silica controlled cultivation). All indentation data were gathered from native tissues under stable and controlled conditions and thus maximize comparability to natural systems. Here we show that native (hydrated) wild boar enamel exceeds any hardness measures known for dry herbivore tooth enamel by at least 3 GPa. The native tooth enamel is not necessarily softer then environmental quartz grit, although there is little overlap. The native hardness of the tooth enamel exceeds that of any silica phytolith hardness recently published. Further, we find that native reed phytoliths equal native suine dentine in hardness, but does not exceed native suine enamel. We also find that native suine enamel is significantly harder than dry enamel and dry phytoliths are harder than native phytoliths. Our data challenge the claim that the culprit of tooth wear may be the food we chew, but suggest instead that wear may relates more to exogenous than endogenous abrasives.