Use Of Talc Research Articles

Lifestyle and reproductive health: the aetiology of ovarian cancer in Pakistan.

Ovarian cancer is a fatal gynaecological cancer and eighth most common cancer in women globally. Lifestyle, reproductive and sociodemographic factors are among the influential parameters that may significantly affect the risk of ovarian cancer and its mortality rate. However, the epidemiological investigations have shown that the risk of ovarian cancers associated with these factors is different in varied geographical distributions. Lifestyle and reproductive factors have not been investigated thoroughly across a wide cultural diversity. The objective of this study is to investigate the association of these factors with ovarian cancer in Pakistan. This investigation will focus on the lifestyle effects of fat intake, intake of tea, habitual exercise, use of talc, personal hygiene, habit of holding urine for long time, obesity on ovarian cancer among Pakistani women. Reproductive variables will include age at menarche, natural menopausal age, parity, nulliparity (miscarriages, abortion, stillbirths), infertility, fertilitytreatment, tubal ligation, oral contraceptive use, and family history of breast or ovarian cancer. Sociodemographic variables will include effect of age, income, education, and geographical location. A case-control study will be conducted in the major cancer hospitals of Pakistan and the patients will also be interviewed. The controls will be recruited outside the hospital. For controls the same age limit and residency requirements will be applied. The information gained from this research will be an important contribution to develop programs for health promotion, with a focus on ovarian cancer prevention and women's health. The findings could be used for health policies and planning to prevent ovarian cancer. The research will pave the way for a public policy and interventions to reduce the burden of ovarian cancer in Pakistan.

Using spinel chemistry to characterise archaeological steatite found in the wall paintings of Tell el-Dabca, Egypt

In the Aegean-type wall paintings of Tell el-Dabca, Egypt, steatite was used as a constituent of the white colour. Previous research has revealed that the use of talc as a pigment can be considered as an important marker of Aegean craft traditions. In this case study it is therefore of primary importance to trace back the origin of this particular mineral and rock, especially since it can be found in several locations in the Mediterranean including Egypt, Crete and Cyprus. While there is still no generally valid strategy to assign archaeological objects made from this particular material to a specific steatite deposit, the physio-chemical characterisation of the latter mostly relies on the measurement of Rare Earth Elements (REE's) or other methods focusing on the chemical composition of the whole rock. In this paper, a new way to determine steatite origin is presented using electron microprobe characterisation of spinels inside the steatite matrix. Those tracer minerals can not only be the source of information concerning the formation of steatite but their core composition can in some cases also reflect the primary composition of the precursor ultramafic rock. This method focuses on the geotectonical history and genesis of the protolith rather than on steatite's chemical composition. The results reveal the spinels to have similar characteristics to those of supra-subduction ophiolites in the Egyptian Central Eastern Desert. We suggest a correlation between gold and steatite exploitation and thus the use of local raw materials for the creation of the Aegean-type paintings.

Mesothelioma Associated With the Use of Cosmetic Talc.

To describe 33 cases of malignant mesothelioma among individuals with no known asbestos exposure other than cosmetic talcum powder. Cases were referred for medico-legal evaluation, and tissue digestions were performed in some cases. Tissue digestion for the six cases described was done according to standard methodology. Asbestos of the type found in talcum powder was found in all six cases evaluated. Talcum powder usage was the only source of asbestos for all 33 cases. Exposure to asbestos-contaminated talcum powders can cause mesothelioma. Clinicians should elicit a history of talcum powder usage in all patients presenting with mesothelioma.

Perineal Talc Use, Douching, and the Risk of Uterine Cancer.

Perineal talc use and douching could affect the risk of uterine cancer through several possible pathways, including inflammation response, microbiota changes, or endocrine disruption. Two previous cohort studies of the association between talc use and uterine cancer have reported weak positive associations, but we know of no previous evaluations of the relationship between douching and uterine cancer. Using a large prospective cohort, we examined the relationship between incident uterine cancer and self-reported use of talc or douche using Cox proportional hazards models. After excluding those with prior hysterectomy, 271 of 33,609 women reported incident uterine cancer (mean follow-up = 8.3 years in noncases; maximum 12.6 years). Overall, 26% of women reported ever using talc and 15% reported ever having douched. Ever talc use was associated with an increase in risk of uterine cancer (adjusted hazard ratio [HR] = 1.2; 95% confidence interval [CI] = 0.94, 1.6), with some evidence of a dose-response for frequency of talc use (P-for-trend = 0.07). Ever douching was not associated with uterine cancer risk (HR = 1.0; 95% CI = 0.72, 1.5), with no evidence of a frequency dose-response (P = 0.96). The estimates were similar when we restricted to invasive endometrial cancers, but not when we further restricted to endometroid adenocarcinomas. The positive association we observed between talc use and uterine cancer risk is consistent with findings from previous prospective cohort studies of endometrial cancer. The relationships between uterine cancer and both douching and talc use merit further consideration, particularly as both exposures are preventable.

Amorphous magnesium silicate ultrasound-assisted precipitation in a mixing system: Population balance modelling and crystallization rates identification

Natural talc is a very interesting filler for plastic and rubber materials and paints because it enables polymer matrix properties to be improved. Nano-sized particles are required to get a good dispersion of the solid in the polymer matrix. However, at the moment the main drawback in the use of natural talc is that, with a conventional milling process, nanometric particle sizes are difficult and expensive to obtain. A process of magnesium silicate synthesis made by ultrasound-assisted precipitation has been developed in two steps. The first step consists of the synthesis of amorphous magnesium silicate by precipitation from sodium metasilicate and acid magnesium chloride. In the second step, the amorphous solid is transformed in a crystalline solid under pressure. In this study an ultrasound-assisted synthesis of amorphous magnesium silicate is proposed. Some process parameters (ultrasound power, initial reactants molalities and reactants flow rate) have effects on the particle-size distribution. The population balance is modelled and solved by moments method in the steady state to identify nucleation and growth rates and agglomeration kernel as a function of operating conditions and to understand how these conditions affect the particle-size distribution.

Particle size, distribution, and behavior of talc preparations: within the United States and beyond.

Talc remains a common sclerosant utilized for pleurodesis. However, the use of talc has documented complications and debate has persisted regarding the safety of talc as well as the differences in talc preparations available throughout the world. We sought to describe an up-to-date review of talc preparations available and the impact these preparations may have on the safety profile of talc. Within laboratory-based examinations, talc particle size available within the United States appears to be more consistent with prior reported 'safe' particle sizes. The presence of talc within protein-based solutions appears to modify the overall milieu of the solution and likely results in particle aggregation. The use of talc remains well accepted for pleurodesis as evidenced by inclusion by multiple guidelines. The medical fields' current understanding of talc and its basic interactions within the pleural space remain limited. Multiple questions related to the pleural space and pleurodesis remain unanswered.

Effects of Some Mineral Substrates on Qualitative and Quantitative Traits of Tuberose (Plianthes tuberosa L.)

Tuberose is one of the most important aromatic cut flower among ornamental plants that its growth and quality is influenced by the type and percentage of mineral compounds in the substrate. This study was carried out on the basis of a randomized complete design to explore the impact of feldspar, talc, dolomite and tuff minerals at the rate of 10, 20 and 40% incorporated with garden soil and manure on some quantitative and qualitative traits of Tuberose plants. The results showed that the highest stem diameter, floret number, root fresh and dry weight were obtained from plants grown in garden soil + dolomite + manure at the ratios of 40:40:20% and 60:20:20%. The highest stem length, floret fresh weight, content of chlorophyll b and total chlorophyll were detected in the plants treated with garden soil + talc and manure (40:40:20%). Highest daughter bulb perimeter, total bulb weight, and floret dry weight were obtained from plants treated with garden soil + feldspar + manure (40:40:20%). Highest floret length and width were seen in plants grown in garden soil + tuff + manure (70:10:20%) and garden soil + talc + manure (60:20:20%). Plants that were grown in garden soil + feldspar + manure at the ratios of 70:10:20% and 60:20:20% had the highest chlorophyll a content and the lowest daughter bulb perimeter, stem length and width, floret dry weight, width and number of floret, chlorophyll b, and total chlorophyll content respectively. Highest root dry weight was measured in control (garden soil + manure 80:20%) and the lowest root fresh and dry weights and volume were recorded for plants grown in garden soil + tuff mineral soil + manure (40:40:20%). Overall, the use of talc, dolomite, and feldspar at the ratio of 40% as Mg and K supplying minerals can improve growth and biochemical parameters of the Tuberose plant.

Synthetic talc as catalyst and filler for waterborne polyurethane-based nanocomposite synthesis

In this work, synthetic talc was used as catalyst and filler aiming to obtain waterborne polyurethane (WPU) nanocomposites by in situ polymerization. Filler was used both in gel and in powder forms in order to compare its effects into the WPU matrix. The use of synthetic talc as filler is interesting due to the possibility of hydrogen bond formation between WPU chains/Si–O–Si and OH groups in synthetic talc edges promoting changes in physical, mechanical and thermal properties. Moreover, WPUs are environmentally friendly polymers replacing organic solvents by water as dispersion medium reducing pollutant emission in the atmosphere. Material structure analyzed by FTIR evidenced that it is possible to synthesize WPU using synthetic talc as catalyst and proved hydrogen bonding formation between synthetic talcs and WPU matrix. Synthetic talcs were well dispersed even with higher filler content, as supported by XRD, TEM, FESEM and AFM analyses. Thermal and mechanical performance was improved with synthetic talc fillers’ addition in order to obtain WPU nanocomposites. Also, Tg of WPU nanocomposites was affected by fillers’ addition as presented by DSC corroborating synthetic talc good dispersion as evidenced by XRD and TEM analyses. Synthetic talcs used as catalyst/filler resulted in nanocomposites with superior thermal and mechanical properties being a new path to utilize synthetic talcs to obtain multifunctional materials.

Technological Solution of Biogas Output Increasing at Grain Distillery Spent Wash Fermentation

Background. Distillery spent wash is the main waste of the alcohol industry. This is highly concentrated wastewater, which is characterized by high chemical oxygen demand (COD) values – up to 60–120 g O 2 /dm 3 – and low pH values – up to 3.7. It makes its processing a complicated task. One of the methods of its utilization is anaerobic fermentation with the production of biogas. Inert carriers for microorganism immobilization or granulation are used to intensify the process of anaerobic treatment and increase sludge concentration. Due to the high concentration of anaerobic microorganisms in granules, compared to the number of microorganisms in free-floating active sludge, the process of methanogenesis is more intensive with a high yield of biogas and a decrease in COD. Objective. To determine the possible centres of anaerobic sludge granulation in highly concentrated waste of alcohol production to increase biogas output in the process of waste treatment. Method s . Activated carbon, modified carbon on which surface calcium ions were precipitated, FeCl 3 , silica gel based sorbent, talc based sorbent were used to form pellets as the centres of microorganism accumulation. Results. Pellets have not been formed with the use of activated carbon; modified carbon with calcium ions; silica gel based sorbent and ferrum compounds. Pellets of activated sludge were received with the use of talc based sorbent – formation of initial biofilm on a carrier was observed on the third day of fermentation and then it was growing in pellets. Conclusions. It was demonstrated that for highly concentrated waste effluents of a distillery (grain distillery spent wash), which after co-fermentation with poultry manure contain volatile fatty acids in concentration 800–2000 mg/dm 3 , it is needed to use sorbents to receive microorganism pellets as a centre of granulation. Sorbents must contain donors and proton acceptors. It was established that the use of granular activated sludge for the distillery waste purification improves the efficiency of COD and Biochemical Oxygen Demand removal by 15–17%, increases biogas output by 26 ± 2% and biogas methane content by 8 ± 1%.

Efficacy and safety of Viscum album extract (Helixor-M) to treat malignant pleural effusion in patients with lung cancer

Manifestations of malignant pleural effusions (MPEs) are alleviated by local therapies as well as by systemic treatment. After 2009, when commercial use of talc was discontinued in Korea, we have used Helixor-M, which is derived from the European mistletoe (Viscum album), as an alternative sclerosing agent for pleurodesis. We aimed to evaluate the efficacy and safety of Helixor-M for controlling MPE. Between 2009 and 2015, we consecutively enrolled 52 patients with lung cancer, who underwent pleurodesis to treat MPE and were analyzed retrospectively. On day 1, 100mg of Helixor-M was instilled via pleural catheter. If the procedure was not effective, it was repeated every other day up to five times, and the dose increased each time by 100mg. The primary study outcome was reappearance of pleural effusion at 1month after the last pleurodesis procedure. The median age of patient was 63years, and 77% of the 52 patients were male. About 85% of pleural effusions were found to be malignant by cytogenetic analysis. Forty-two (81%) patients were evaluable for recurrence of MPE. The 1-month recurrence rate was 48% (20/42). Among the 20 patients who developed recurrent MPE, 6 required therapeutic thoracentesis. Thirteen (25%) patients experienced procedure-related pain requiring medication. Eight (15%) had fever > 38°C. Our results suggest that a pleurodesis with Helixor-M was an effective and tolerable procedure for controlling MPE in lung cancer patients.

Use of talc in oil mills: Influence on the quality and content of minor compounds in olive oils

In oil milling, in order to obtain high-quality oils without reducing the industrial yield, to the use of coadjuvants with a physical action and adequate operating conditions is necessary. The aim of this study was to evaluate the influence of talc addition during the malaxation stage in an oil mill on the resulting oil. Moreover, the oil obtained by talc treatment can be classified as extra virgin olive oil as this coadjuvant has a physical action. Talc increases the extraction efficacy by up to 2.35%, but retains 26.2% of its weight in oil; therefore, it is disadvantageous to use a dose higher than 0.75%. The volatile compound contents were increased in trials using lower doses of talc. In contrast, the quantity of the phenolic compounds was increased in trials using higher talc doses. In low doses, talc does not influence the content of antioxidants and volatile compounds.

Genital use of talc and risk of ovarian cancer: a meta-analysis.

Some epidemiological studies suggest an association between genital use of talc powders and increased risk of ovarian cancer, but the evidence is not consistent. We performed a meta-analysis of epidemiological studies to formally evaluate this suspected association. A systematic search was conducted in Medline, Embase, and Scopus, leading to the identification of 24 case-control studies and three cohort studies. In the meta-analysis, we used a random-effect model to calculate summary estimates of the association between genital use of talc and occurrence of ovarian cancer. We assessed potential sources of between-study heterogeneity and presence of publication bias. The summary relative risk (RR) for ever use of genital talc and ovarian cancer was 1.22 [95% confidence interval (CI): 1.13-1.30]. The RR for case-control studies was 1.26 (95% CI: 1.17-1.35) and for cohort studies was 1.02 (95% CI: 0.85-1.20, Pheterogeneity=0.007). Serous carcinoma was the only histologic type for which an association was detected (RR: 1.24; 95% CI: 1.15-1.34). There was a weak trend in RR with duration and frequency of genital talc use. This meta-analysis resulted in a weak but statistically significant association between genital use of talc and ovarian cancer, which appears to be limited to serous carcinoma with suggestion of dose-response. The heterogeneity of results by study design however, detracts from a causal interpretation of this association.

Synthetic talc as a new platform for producing fluorescent clay polyurethane nanocomposites

As a non-swelling clay, talc generally interacts very weakly with organic molecules. However, two new nanometric synthetic talcs that incorporate berberine chloride were successfully used as fluorescent fillers in clay polyurethane nanocomposites obtained by the blending method. A micrometric natural talc filler was also used for comparison. The clay polymer nanocomposites (CPN) were characterized by FTIR, molar mass analysis and XRD. All talc fillers were well dispersed into the polyurethane matrix even at high filler content of 5 wt%, as supported by TEM and SEM analyses. Morphological changes were confirmed by AFM. The optical properties of the fluorescent talcs, dye-doped polymer and CPN were compared. While the dye-doped polymer suffered from conventional fluorescence quenching due to dye aggregation, the emission quantum yield of the CPN was increased with increasing the filler content. The best emission efficiency was observed for the CPN that contains the smallest talc-berberine hybrid particles. The use of fluorescent synthetic talc resulted in materials with good thermal and mechanical properties, and can be considered as a new method to produce fluorescent CPN in view of multiple applications.

Perineal Talc Use and Ovarian Cancer: A Systematic Review and Meta-Analysis.

It has been posited that there is an association between perineal talc use and the incidence of ovarian cancer. To date, this has only been explored in observational studies. To perform a meta-analysis to evaluate the association between perineal talc use and risk of ovarian cancer. Studies were identified using six electronic databases. Observational studies involving at least 50 cases of ovarian cancer were eligible for inclusion. We analyzed the association between ovarian cancer, including specific types, and any perineal talc use, long-term (>10 years) use, total lifetime applications, and use on diaphragms or sanitary napkins. A subgroup analysis was performed, stratifying by study design and population. We identified 24 case-control (13,421 cases) and three cohort studies (890 cases, 181,860 person-years). Any perineal talc use was associated with increased risk of ovarian cancer (OR = 1.31; 95% CI = 1.24, 1.39). More than 3600 lifetime applications (OR = 1.42; 95% CI = 1.25, 1.61) were slightly more associated with ovarian cancer than <3600 (OR = 1.32; 95% CI = 1.15, 1.50). An association with ever use of talc was found in case-control studies (OR = 1.35; 95% CI = 1.27, 1.43), but not cohort studies (OR = 1.06; 95% CI = 0.90, 1.25). However, cohort studies found an association between talc use and invasive serous type ovarian cancer (OR = 1.25; 95% CI = 1.01, 1.55). We found an increased risk of serous and endometrioid, but not mucinous or clear cell subtypes. In general, there is a consistent association between perineal talc use and ovarian cancer. Some variation in the magnitude of the effect was found when considering study design and ovarian cancer subtype.

Waterborne polyurethane/Fe3O4-synthetic talc composites: synthesis, characterization, and magnetic properties

Nano-Fe3O4-synthetic talc gel was used as filler in the synthesis of waterborne polyurethane/Fe3O4-synthetic talc nanocomposites. This filler presents numerous edges (Si–O and Mg–O) and OH groups easily forming hydrogen bonds and polar interaction with water conferring hydrophilic character, consequently improving filler dispersion within a water-based matrix. Yet, the use of waterborne polyurethane (WPU) as matrix must be highlighted due to its environmentally friendly characteristics and low toxicity compared to solvent-based product. Fe3O4-synthetic talc-nanofillers were well dispersed into the polyurethane matrix even at high filler content as supported by XRD and TEM analyses. NMR indicates the interaction of filler OH groups with the matrix. For all nanocomposites, one can see a typical ferromagnetic behavior below Curie temperature (about 120 K) and a superparamagnetic behavior above this temperature. The use of Fe3O4-synthetic talc for obtaining magnetic nanocomposites resulted in improved materials with superior mechanical properties compared to solvent-based nanocomposites.

Abstract 2301: Genital use of talc and risk of ovarian cancer: A meta-analysis

Abstract Some epidemiological studies suggest an association between genital use of talc powders and increased risk of ovarian cancer, but the evidence is not consistent. We performed a meta-analysis of epidemiologic studies to formally evaluate this suspected association. A systematic search was conducted in Medline, Embase and Scopus, leading to the identification of 24 case-control studies and 3 cohort studies, including 302,705 women with ovarian cancer. In the meta-analysis, we used a random-effect model to calculate summary estimates of the association between genital use of talc and occurrence of ovarian cancer. We assessed potential sources of between-study heterogeneity and presence of publication bias. The summary relative risk (RR) for ever use of genital talc and ovarian cancer was 1.22 (95% confidence interval [CI] 1.13-1.30). The RR for case-control studies was 1.26 (95% CI 1.17-1.35) and for cohort studies was 1.02 (95% CI 0.85-1.20, p heterogeneity=0.007). Serous carcinoma was the only histologic type for which an association was detected (RR 1.24; 95% CI 1.15-1.34). There was no trend in RR with either duration or frequency of genital talc use. This meta-analysis resulted in a weak but statistically significant association between genital use of talc and ovarian cancer, which appears to be limited to serous carcinoma. The heterogeneity of results by study design and the lack of a trend for duration and frequency of use, however, detract from a causal interpretation of this association. Note: This abstract was not presented at the meeting. Citation Format: Paolo Boffetta, Wera Berge. Genital use of talc and risk of ovarian cancer: A meta-analysis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2301. doi:10.1158/1538-7445.AM2017-2301

Interface enhancement between polytetrafluoroethylene and glass fibers modified with a titanate coupler

ABSTRACTThe use of glass fibers (GFs), molybdenum disulfide (MoS2), and talc was evaluated to reinforce polytetrafluoroethylene (PTFE) for potential applications in automobile shock absorber pistons. The orthogonal experiment results show that the optimal GF/MoS2/talc/PTFE weight ratio was 2:3:3:92 for the PTFE composite; this ratio resulted in better mechanical properties, hardness, low linear expansion, and wear rate. Chemical coupling and high‐temperature activation treatment on the surface of GF greatly enhanced the interfacial adhesion between the PTFE matrix and GF, as revealed by atomic force microscopy analysis. This resulted in reductions in the wear rate and linear expansion coefficient by two orders of magnitude compared with that of PTFE. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44668.

TALC EFFECT ON THE VOLATILES OF VIRGIN OLIVE OIL DURING STORAGE

The aim of the study was to assess the influence of talc on the extra virgin olive oil volatile profile during storage. The obtained results showed that the volatile profile of the oil produced without talc addition was rich in C6 volatiles and poor in esters. The Principal Component Analysis discriminated 6-month stored oils, characterized by higher amount of auto-oxidation volatile compounds, from 3-month stored and fresh oils. The use of talc did not significantly influence the volatile profile of the examined oils during storage, with the exception of C6-LOX aldehydes that significantly decreased as a consequence of talc addition.

Effect of foam processing parameters on bubble nucleation and growth dynamics in high-pressure foam injection molding

We used an innovative visualization mold to investigate the effect of foam processing parameters on bubble nucleation and growth. This was also done to uncover the mechanisms responsible for cellular structural development in the high-pressure foam injection molding process. The effects of the injection speed, the injection gate geometry, the blowing agent content, the melt flow rate and the use of talc as a heterogeneous nucleating agent on the formation and dynamics of cell bubbles were all explored. In the high-pressure foam injection molding process with a proper packing pressure, the overall cell density did not change with the injection speed nor with the injection gate resistance. However, the cell density increased significantly with the blowing agent's concentration and with a nucleating agent. We also observed the growth mechanism of the bubbles in a confined mold cavity, and concluded that the bubble growth rate decreased as the cell density increased. In addition, the satelliting phenomenon, i.e. bubble nucleation around the previously nucleated cells, was observed. This was due to the induced stress fluctuations in the surrounding melt, which could eventually affect the final cellular structure.

Micronized natural talc affects the proteins and pectic cell wall polysaccharides during “Hojiblanca” virgin olive oil extraction

This work studies how using MNT affects cell wall polysaccharides and proteins of “Hojiblanca” paste during virgin olive oil extraction. Four doses of MNT were assessed: 0, 0.25, 0.5, and 1%. Three pectic fractions were extracted from alcohol insoluble solids (AIS): water‐soluble pectin (WSP), chelate‐soluble pectin (CSP), and non‐soluble pectin (NSP). In general, the content of the three pectic fractions decreased throughout the kneading step. This indicated a significant degradation and solubilization of pectins during processing. The same trend was observed for protein content and total pectin content while AIS yield increased. Addition of MNT at doses lower than 0.5% favored the formation of a chemical bound through electrostatic interactions between proteins and pectic polysaccharides which are held together and adsorbed onto the talc surface giving a decrease in their content. Higher MNT doses (1%) produced the opposite behavior. The lowest dose of MNT (0.25%) reduced the oil losses in the pomace. A certain tendency for the loss of oil in the pomace to decrease as the amount of total pectin and protein decreased was observed, indicating that the oil yield is at least in part, related to the pectin and protein content depending on the dose of MNT added during malaxation step.Practical application: We have demonstrated that the use of talc during the malaxation step greatly lessens the effect of the pectic substrates and proteins, principal emulsifier agents that influence the formation of oil‐in‐water emulsions during oil extraction process and enhance the extraction of the oil from the mesocarp cells by reducing its loose in the pomace. Excess of talk addition presented a reverse effect, though. It is, therefore, of the utmost importance that the information contained in this study is fully taken into account to establish the suitable dose of talc that should be applied when difficult pastes are formed during malaxation step and which at least partially depends on the content of proteins and pectin compounds of the processed olive paste.Proteins and pectic cell wall polysaccharides as affected by talc addition during virgin olive oil extraction.