RESUMEN
OBJECTIVE: Talc pleurodesis is a widely used treatment option for malignant pleural effusion (MPE). However, the optimal form of administration remains controversial. Thus, we performed a systematic review and meta-analysis to assess the effectiveness of talc slurry (TS) in comparison with thoracoscopic talc insufflation/poudrage (TTI) for MPE treatment. METHODS: We searched PubMed, EMBASE, and Cochrane Library databases for studies that compared TS with TTI in patients with MPE. We used a random-effects model with a 95% CI to pool the data. Heterogeneity was assessed with I2 statistics. RESULTS: We included eight studies involving 1,163 patients, 584 of whom (50.21%) underwent TS. Pleurodesis failure rates were similar between the procedures (OR = 1.07; 95% CI: 0.56-2.06; p = 0.83; I2 = 62%); and 68% of patients (95% CI: 0.31-1.47; p = 0.33; I2 = 58%) had postoperative complications, which were lower in patients in the TS group than in the TTI group. In a subgroup analysis considering only randomized clinical trials, the failure rate was significantly lower in the TS treatment group (OR = 0.62; 95% CI: 0.42-0.90; p = 0.01; I2 = 0%). Similarly, dyspnea was less common in the TS group (OR = 0.74; 95% CI: 0.41-1.34; p = 0.32; I2 = 55%). Adverse effects were reported in 86 patients, and no significant difference was seen between the TS and TTI groups: empyema (OR = 1.43; 95% CI: 0.36-5.64; p = 0.86; I2 = 0%), pain (OR = 1.22 (95% CI: 0.67-2.21; p = 0.51; I2 = 38%), and pneumonia (OR = 1.15; 95% CI: 0.30-4.46; p = 0.86; I2 = 27%). CONCLUSIONS: Our findings suggest that TS is an effective treatment for MPE, with no significant increase in adverse events. Results suggest equivalent efficacy and safety for both procedures.
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Insuflación , Derrame Pleural Maligno , Pleurodesia , Talco , Toracoscopía , Humanos , Talco/administración & dosificación , Derrame Pleural Maligno/terapia , Pleurodesia/métodos , Insuflación/métodos , Insuflación/efectos adversos , Toracoscopía/métodos , Toracoscopía/efectos adversos , Resultado del Tratamiento , Reproducibilidad de los ResultadosRESUMEN
As a common food raw material in daily life, the quality and safety of wheat flour are directly related to people's health. In this study, a model was developed for the rapid identification and detection of three illegal additives in flour, namely azodicarbonamide (ADA), talcum powder, and gypsum powder. This model utilized a combination of near-infrared spectroscopy with chemometric methods. A one-dimensional convolutional neural network was used to reduce data dimensionality, while a support vector machine was applied for non-linear classification to identify illegal additives in flour. The model achieved a calibration set F1 score of 99.38% and accuracy of 99.63%, with a validation set F1 score of 98.81% and accuracy of 98.89%. Two cascaded wavelength selection methods were introduced: The first method involved backward interval partial least squares (BiPLS) combined with an improved binary particle swarm optimization algorithm (IBPSO). The second method utilized the CARS-IBPSO algorithm, which integrated competitive adaptive reweighted sampling (CARS) with IBPSO. The two cascade wavelength selection methods were used to select feature wavelengths associated with additives and construct partial least squares quantitative detection models. The models constructed using CARS-IBPSO selected feature wavelengths for detecting ADA, talcum powder, and gypsum powder exhibited the highest overall performance. The model achieved validation set determination coefficients of 0.9786, 0.9102, and 0.9226, with corresponding to root mean square errors of 0.0024%, 1.3693%, and 1.6506% and residual predictive deviations of 6.8368, 3.5852, and 3.9253, respectively. Near-infrared spectroscopy in combination with convolutional neural network dimensionality reduction and support vector machine classification enabled rapid identification of various illegal additives. The combination of CARS-IBPSO feature wavelength selection and partial least squares regression models facilitated rapid quantitative detection of these additives. This study introduces a new approach for rapidly and accurately identifying and detecting illegal additives in flour.
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Harina , Espectroscopía Infrarroja Corta , Triticum , Harina/análisis , Espectroscopía Infrarroja Corta/métodos , Triticum/química , Análisis de los Mínimos Cuadrados , Quimiometría/métodos , Aditivos Alimentarios/análisis , Máquina de Vectores de Soporte , Redes Neurales de la Computación , Sulfato de Calcio/química , Sulfato de Calcio/análisis , Talco/análisis , Talco/química , AlgoritmosRESUMEN
The potential carcinogenicity of talc has been evaluated in many studies in humans and experimental animals published in the scientific literature over the last several decades, with a number of these studies reporting no associations between talc exposure and any type of cancer. In order to fully understand the current state of the science regarding the potential for talc to induce human cancers, we conducted a comprehensive and systematic review of the available experimental animal and mechanistic evidence (in conjunction with a systematic review of the epidemiology evidence in a companion analysis) to evaluate whether it supports talc as being carcinogenic to humans. We considered study quality and its impact on the interpretation of results and evaluated all types of cancer and all exposure routes. We also evaluated the evidence on the potential for talc to migrate in the body to potential tumor sites. We identified seven experimental animal carcinogenicity studies and 11 mechanistic studies of talc to systematically review. We found that several of the experimental animal carcinogenicity studies of talc have limitations that preclude their sensitivity to detect increases in tumor incidence. Regardless, the studies cover multiple exposure routes, species, and exposure durations, and none indicate that talc is a carcinogen in experimental animals except in rats under conditions of extremely high exposure that likely resulted in lung particle overload, a nonspecific effect of high exposures to poorly soluble particles, and not from any carcinogenic properties of talc. Lung particle overload leading to lung tumor formation has only been observed in rats and not in any other species, including humans. The mechanistic studies indicate that talc is not genotoxic or mutagenic, but can induce some effects that could be events on a possible pathway to carcinogenicity, mainly at high exposures or in in vitro studies with exposures of unclear relevance in vivo, but these effects are not consistent across studies and cell types. This systematic review of the experimental animal carcinogenicity and mechanistic evidence for talc indicates that an association between talc exposure and cancer is not expected in humans. Talc carcinogenicity is not plausible in any species except rats, and only when the exposure conditions are high enough to induce lung particle overload, which is not relevant to human exposures.
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Neoplasias , Talco , Talco/toxicidad , Animales , Humanos , Neoplasias/inducido químicamente , Neoplasias/epidemiología , Carcinógenos/toxicidad , Pruebas de CarcinogenicidadRESUMEN
Bed bugs are considered a major public health problem in industrialized countries. Usually, bed bug infestations are managed using a combination of physical and chemical methods. In recent years, new strategies for bed bug control have emerged, particularly the use of dusts like diatomaceous earth and silicon dioxide. However, in Europe, the use of silicon dioxide is restricted to professional, while diatomaceous earth can be harmful to the lungs. This study aimed to assess bed bug mortality rates associated with Sommières earth, green clay, talc, and sodium bicarbonate compared to silicon dioxide and diatomaceous earth from a pest management company, diatomaceous earth for litter conditioner, and diatomaceous earth from a supermarket. We tested permanent exposure, short exposure, horizontal transfer and repellent effect on two bed bug colonies. Sommières earth demonstrated efficacy ranging from 75% to 100% in permanent and short exposures, similar to the efficacy of diatomaceous earth from the pest management company. On the contrary, diatomaceous earth for litter conditioner and diatomaceous earth from a supermarket, green clay, talc, and sodium bicarbonate were found to be ineffective. This study demonstrates, for the first time, the efficacy of Sommières earth against bed bugs, but also highlights the variability in efficacy of diatomaceous earths on bed bugs depending on their quality.
Title: Lutte contre les punaises de lit avec des poudres : comparaison de l'efficacité du dioxyde de silicium, de la terre de diatomée et de la terre de Sommières. Abstract: Les punaises de lit sont considérées comme un problème de santé publique majeur dans les pays industrialisés. Habituellement, les infestations de punaises de lit sont gérées en utilisant une combinaison de méthodes physiques et chimiques. Ces dernières années, de nouvelles stratégies de lutte contre les punaises de lit ont vu le jour, notamment l'utilisation de poudres comme la terre de diatomées et le dioxyde de silicium. Cependant, en Europe, l'usage du dioxyde de silicium est réservé aux professionnels tandis que la terre de diatomées peut être nocive pour les poumons. Cette étude visait à évaluer les taux de mortalité des punaises de lit associés à la terre de Sommières, à l'argile verte, au talc et au bicarbonate de sodium par rapport au dioxyde de silicium, à la terre de diatomées d'une entreprise de lutte antiparasitaire, à la terre de diatomées pour conditionneur de litière et à la terre de diatomées d'un supermarché. Nous avons testé l'exposition permanente, l'exposition courte, le transfert horizontal et l'effet répulsif sur deux colonies de punaises de lit. La terre de Sommières a démontré une efficacité allant de 75% à 100% en exposition permanente et courte, similaire à l'efficacité de la terre de diatomées d'une entreprise de lutte antiparasitaire. Au contraire, la terre de diatomées pour conditionneur de litière et la terre de diatomées d'un supermarché, l'argile verte, le talc et le bicarbonate de sodium se sont révélés inefficaces. Cette étude démontre, pour la première fois, l'efficacité de la terre de Sommières contre les punaises de lit mais met également en évidence la variabilité de l'efficacité des terres de diatomées sur les punaises de lit en fonction de leur qualité.
Asunto(s)
Chinches , Tierra de Diatomeas , Control de Insectos , Dióxido de Silicio , Talco , Animales , Chinches/efectos de los fármacos , Control de Insectos/métodos , Polvo/análisis , Arcilla/química , Bicarbonato de Sodio/farmacologíaRESUMEN
BACKGROUND: in 2006, the International Agency for Research on Cancer (IARC) concluded that the evidence of carcinogenicity for asbestos-free talc was inadequate (group 3), whereas perineal use of talcum powder was classified as possibly carcinogenic (group 2B). OBJECTIVES: to assess whether later studies provide more solid information on the carcinogenic risk from asbestos-free talc and talcum powder and a better characterization of exposure. DESIGN: systematic review. METHODS: cohort studies of talc miners and millers exposed to asbestos-free talc, as well as cohort and case-control studies reporting cancer risk in talc powder consumers published from 2006 onwards were identified through PubMed and reference lists. Pooled analyses were included, but not reviews and meta-analyses. In the case of repeatedly reported studies, the article with the longest follow-up or the largest number of observed cases was selected for data abstraction. Notice was taken of studies which were both reported individually and included in pooled analyses. RESULTS: publications meeting inclusion criteria were: 2 cohort studies on talc miners and millers, 10 cohort studies on talcum powder users (4 of which estimated ovarian cancer risk), and 14 case-control studies (13 on ovarian and 1 on endometrial cancer) on the risk from talcum powder use. No excess cancer mortality has been reported among asbestos-free talc miners and millers. Case-control studies consistently led to estimates of ovarian cancer excesses associated with the use of perineal talcum powder (odds ratios up to 1.5). Most studies quantifying exposure also provided evidence of a dose-response relationship. Individual cohort studies estimated hazard ratios (HR) just above 1. In an analysis of pooled cohorts for a total of 3,112 cases, the HR for women with patent reproductive tract was 1.13 (95%CI 1.01-1.26) with a correlation between HR and frequency of use (p for trend 0.03). In all cohort studies, the perineal use of talcum powder was measured only once in the early phases of follow-up, thus producing an inaccurate measure of cumulative exposure. Results of epidemiological studies regarding cancer risk in other organs are limited and inconsistent. CONCLUSIONS: epidemiological studies updated or published after IARC 2006 evaluation indicate that: no increase in cancer risk is apparent among miners and millers of asbestos-free talc; risk for ovarian cancer increases following the perineal use of commercial talcum powder. A correlation between indicators of quantity of use and cancer risk is suggested by a number of studies. The composition of talcum powders considered in such studies is not known.
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Enfermedades Profesionales , Exposición Profesional , Talco , Femenino , Humanos , Masculino , Carcinógenos/toxicidad , Estudios de Casos y Controles , Cosméticos , Neoplasias Endometriales/epidemiología , Neoplasias Endometriales/inducido químicamente , Neoplasias Pulmonares/epidemiología , Neoplasias Pulmonares/inducido químicamente , Neoplasias Pulmonares/etiología , Neoplasias/epidemiología , Neoplasias/inducido químicamente , Neoplasias/etiología , Enfermedades Profesionales/epidemiología , Enfermedades Profesionales/inducido químicamente , Exposición Profesional/efectos adversos , Neoplasias Ováricas/epidemiología , Neoplasias Ováricas/inducido químicamente , Talco/efectos adversosRESUMEN
The presence of asbestos in cosmetic talc has been reported in the United States since the 1970s. The present article first retraces the Italian case, then focuses on technical features as well as the relevant laws, rules, and regulations, ending with a precautionary evidence-based approach. Research was mainly aimed at retrieving official Italian Health Authority papers on the tests carried out several decades ago, to identify the presence of any asbestos in talc of products for sale. Results show that, in Italy, National Institute of Health (the technical agency of the Ministry of Health) and the Italian Pharmacopoeia (1985) used scanning electron microscopy (SEM) to ascertain the absence of asbestos fibres, following positive identification in several samples they had analysed. In 2008, Italy adopted the EU Pharmacopoeia according to which light microscopy (LM) was sufficient for analysis. Such a technical downgrading clearly went - and goes - against the standard principle of precaution to prevent harm to users' health.Unfortunately, documents on the above-mentioned SEM research that would have contextualized observations were not recovered from the Italian State Archive. Observations and results indicate that in practice levels of attention on the issue underwent a considerable (negative) decline, so much that effective planning of the necessary controls was not possible, which is unfortunately true to this day. Final comments deal with the principle of precaution and possible practical operational solutions.
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Amianto , Cosméticos , Italia , Humanos , Talco , Microscopía Electrónica de Rastreo , Medición de RiesgoRESUMEN
Over the past several decades, there have been many epidemiology studies on talc and cancer published in the scientific literature, and several reviews and meta-analyses of talc and respiratory, female reproductive, and stomach cancers, specifically. To help provide a resource for the evaluation of talc as a potential human carcinogen, we applied a consistent set of examination methods and criteria for all epidemiology studies that examined the association between talc exposure (by various routes) and cancers (of various types). We identified 30 cohort, 35 case-control, and 12 pooled studies that evaluated occupational, medicinal, and personal-care product talc exposure and cancers of the respiratory system, the female reproductive tract, the gastrointestinal tract, the urinary system, the lymphohematopoietic system, the prostate, male genital organs, and the central nervous system, as well as skin, eye, bone, connective tissue, peritoneal, and breast cancers. We tabulated study characteristics, quality, and results in a systematic manner, and evaluated all cancer types for which studies of at least three unique populations were available in a narrative review. We focused on study quality aspects most likely to impact the interpretation of results. We found that only one study, of medicinal talc use, evaluated direct exposure measurements for any individuals, though some used semi-quantitative exposure metrics, and few studies adequately assessed potential confounders. The only consistent associations were with ovarian cancer in case-control studies and these associations were likely impacted by recall and potentially other biases. This systematic review indicates that epidemiology studies do not support a causal association between occupational, medicinal, or personal talc exposure and any cancer in humans.
Asunto(s)
Neoplasias , Talco , Talco/toxicidad , Humanos , Neoplasias/epidemiología , Neoplasias/inducido químicamente , Femenino , Exposición Profesional , Masculino , Carcinógenos/toxicidadRESUMEN
PURPOSE: Intimate care products may contain substances associated with increased risk of hormone-related cancers. The relationship between genital talc use and ovarian cancer, in particular, has been well studied, but concerns about recall bias and exposure misclassification have precluded conclusions. We examined the association between intimate care products and female hormone-related cancers, accounting for potential biases, using data from a US-based cohort study. METHODS: The Sister Study enrolled 50,884 women who had a sister with breast cancer. Data on genital talc use and douching were collected at enrollment (2003-2009) and follow-up (2017-2019). We used Cox proportional hazards models to estimate hazard ratios (HRs) for associations between intimate care product use and breast, ovarian, and uterine cancers. To account for potential exposure misclassification and recall bias, we conducted quantitative bias analyses under various exposure reassignment assumptions. RESULTS: Across considered scenarios, 41%-64% of participants douched and 35%-56% used genital talc. In models adjusted for exposure misclassification, genital talc use was positively associated with ovarian cancer (HR range, 1.17-3.34) Frequent douching and douching during young adulthood were positively associated with ovarian cancer, but neither douching nor talc was associated with breast or uterine cancer. Differential reporting of talc use by cases and noncases likely produces positive biases, but correcting for error still resulted in HRs above 1.0. For example, HR, 1.40 (95% CI, 1.04 to 1.89) when 25% of exposed cases and 10% of unexposed noncases had talc status reassigned. CONCLUSION: Although results show how differential recall would upwardly bias estimates, corrected results support a positive association between use of intimate care products, including genital talc, and ovarian cancer.
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Neoplasias de la Mama , Neoplasias Ováricas , Talco , Humanos , Femenino , Talco/efectos adversos , Incidencia , Neoplasias de la Mama/epidemiología , Persona de Mediana Edad , Neoplasias Ováricas/epidemiología , Sesgo , Adulto , Anciano , Neoplasias Uterinas/epidemiología , Estudios de Cohortes , Estados Unidos/epidemiologíaRESUMEN
INTRODUCTION: The link between talcum powder use and cancer, particularly ovarian cancer, has been a topic of scientific research and legal debate for several years. Studies have suggested a potential association between long-term talcum powder use in the genital area and an increased risk of ovarian cancer. AREAS COVERED: The following report includes up-to-date evidence to support the potential link between talcum powder use and the risk of developing ovarian cancer. The International Agency for Research on Cancer, which is part of the World Health Organization, classified talc-based body powder as possibly carcinogenic to humans when used in the female genital area. However, other studies have not consistently supported this association, and thus more research is needed to establish a clear and definitive link between talcum powder use and cancer. Despite this, recent molecular-level data have linked talc to alterations in redox balance, gene mutations, and inflammatory responses. Specifically, we have identified a role for talc to induce the pro-oxidant state, inhibit apoptosis, and more importantly induced cellular transformation in normal ovarian cells. EXPERT OPINION: We presented unequivocal evidence to support our opinion that talc is not biologically inert and induces molecular changes that mimic the hallmarks of cancer.
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Neoplasias Ováricas , Estrés Oxidativo , Talco , Talco/efectos adversos , Talco/administración & dosificación , Humanos , Femenino , Neoplasias Ováricas/patología , Animales , Apoptosis , Polvos , Transformación Celular Neoplásica/inducido químicamente , Riesgo , Carcinógenos/toxicidadRESUMEN
BACKGROUND: Malignant pleural effusion (MPE) is a debilitating condition as it commonly causes disabling breathlessness and impairs quality of life (QoL). Indwelling pleural catheter (IPC) offers an effective alternative for the management of MPE. However, IPC-related infections remain a significant concern and there are currently no long-term strategies for their prevention. The Australasian Malignant PLeural Effusion (AMPLE)-4 trial is a multicentre randomised trial that evaluates the use of topical mupirocin prophylaxis (vs no mupirocin) to reduce catheter-related infections in patients with MPE treated with an IPC. METHODS: A pragmatic, multi-centre, open-labelled, randomised trial. Eligible patients with MPE and an IPC will be randomised 1:1 to either regular topical mupirocin prophylaxis or no mupirocin (standard care). For the interventional arm, topical mupirocin will be applied around the IPC exit-site after each drainage, at least twice weekly. Weekly follow-up via phone calls or in person will be conducted for up to 6 months. The primary outcome is the percentage of patients who develop an IPC-related (pleural, skin, or tract) infection between the time of catheter insertion and end of follow-up period. Secondary outcomes include analyses of infection (types and episodes), hospitalisation days, health economics, adverse events, and survival. Subject to interim analyses, the trial will recruit up to 418 participants. DISCUSSION: Results from this trial will determine the efficacy of mupirocin prophylaxis in patients who require IPC for MPE. It will provide data on infection rates, microbiology, and potentially infection pathways associated with IPC-related infections. ETHICS AND DISSEMINATION: Sir Charles Gairdner and Osborne Park Health Care Group Human Research Ethics Committee has approved the study (RGS0000005920). Results will be published in peer-reviewed journals and presented at scientific conferences. TRIAL REGISTRATION: Australia New Zealand Clinical Trial Registry ACTRN12623000253606. Registered on 9 March 2023.
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Infecciones Relacionadas con Catéteres , Derrame Pleural Maligno , Humanos , Derrame Pleural Maligno/diagnóstico , Derrame Pleural Maligno/complicaciones , Calidad de Vida , Mupirocina/efectos adversos , Pleurodesia/métodos , Talco/uso terapéutico , Catéteres de Permanencia/efectos adversos , Infecciones Relacionadas con Catéteres/diagnóstico , Infecciones Relacionadas con Catéteres/prevención & control , Antibacterianos/efectos adversos , Ensayos Clínicos Controlados Aleatorios como Asunto , Estudios Multicéntricos como AsuntoRESUMEN
It has long been recognized that amphibole minerals, such as cleavage fragments of tremolite and anthophyllite, may exist in some talc deposits. We reviewed the current state of the science regarding the factors influencing mesotheliogenic potency of cleavage fragments, with emphasis on those that may co-occur in talc deposits, including dimensional and structural characteristics, animal toxicology, and the most well-studied cohort exposed to talc-associated cleavage fragments. Based on our review, multiple lines of scientific evidence demonstrate that inhaled cleavage fragments associated with talc do not pose a mesothelioma hazard.
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Asbestos Anfíboles , Talco , Talco/química , Humanos , Animales , Mesotelioma/inducido químicamente , Exposición Profesional/efectos adversosRESUMEN
Chemical pleurodesis is a technique in which an injurious and inflammatory substance is instilled into the pleural cavity to cause adhesion and fibrosis. It is commonly used in the management of recurrent malignant pleural effusions. Historically, many different types of sclerosants have been described, though only a few, including talc, the tetracycline derivatives, and anti-septic compounds such as silver nitrate and iodopovidone, have found their way into mainstream use. However, over the past several years, there has been increasing interest in alternative pleurodesis agents. In this review, we will explore future directions in the field, with an eye toward novel and investigational agents.
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Pleurodesia , Soluciones Esclerosantes , Pleurodesia/métodos , Humanos , Soluciones Esclerosantes/administración & dosificación , Soluciones Esclerosantes/uso terapéutico , Derrame Pleural Maligno/terapia , Derrame Pleural Maligno/tratamiento farmacológico , Talco/administración & dosificaciónRESUMEN
Streptomyces produce a broad spectrum of biologically active molecules such as oxytetracycline and rimocidin, which are widely used in human and animal treatments. microparticle-enhanced cultivation (MPEC) is one of the tools used for Streptomyces bioprocesses intensification by the control of mycelial morphology. In the present work, morphological changes of Streptomyces rimosus caused by the addition of 10 µm talc microparticles in MPEC were correlated with the biosynthetic activity of the microorganism. Comparing the runs with and without microparticles, major morphological changes were observed in MPEC, including the deformation of pellets, variation of their size, appearance of hyphae and clumps as well as the aggregation of mycelial objects. The presence of talc microparticles also influenced the levels of the studied secondary metabolites produced by S. rimosus. Comparing control and MPEC runs, the addition of talc microparticles increased the amounts of oxytetracycline (9-fold), 2-acetyl-2-decarboxamido-oxytetracycline (7-fold), milbemycin A3+4[O] (3-fold) and CE 108 (1.5-fold), while rimocidin (27-ethyl) and milbemycin ß11+4[O] production was reduced. In summary, the addition of talc microparticles to S. rimosus cultivations led to the development of smaller morphological forms like hyphae and clumps as well as to the changes in the amounts of secondary metabolites.
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Streptomyces rimosus , Streptomyces rimosus/metabolismo , Streptomyces rimosus/crecimiento & desarrollo , Talco/química , Oxitetraciclina/biosíntesisRESUMEN
N-methyl-morpholine-N-oxide (NMMO) was initially created as a plasticizer for starch to produce thermoplastic wheat starch. Subsequently, talc powder was used as a reinforcing filler to enhance the mechanical strength of thermoplastic biomass-based composite plastics. The chemical structure, crystal structure, and microscopic morphology were analyzed using Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy. Additionally, the thermal properties were explored through thermogravimetric analysis, differential scanning calorimetry, and dynamic mechanical analysis. The hydrated NMMO plasticizer demonstrated an outstanding plasticizing effect on starch, resulting in a composite with remarkable mechanical properties. In fact, the pure thermoplastic wheat starch plasticized with hydrated NMMO exhibited the highest mechanical strength recorded so far, with a tensile strength of up to 9.4 MPa. In addition, talcum powder displayed a noticeable reinforcing effect. When the talcum powder content reached 30 wt%, the targeted composite achieved a tensile strength of 20.5 MPa and a Young's modulus of 177.9 MPa. These values were 118 % and 48 % higher, respectively, than those of the pure thermoplastic starch sample. This innovative plasticizing method opens up a new avenue for the development of high-mechanical-strength thermoplastic biomass-based composite plastics with promising potential applications.
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Biomasa , Plastificantes , Plásticos , Almidón , Talco , Resistencia a la Tracción , Triticum , Almidón/química , Talco/química , Triticum/química , Plásticos/química , Plastificantes/química , Polvos , Espectroscopía Infrarroja por Transformada de Fourier , Termogravimetría , Fenómenos Mecánicos , Difracción de Rayos XRESUMEN
INTRODUCTION: Tissue from a 77-year-old man diagnosed with mesothelioma was referred with a request for identification of the presence of fibrous structures in tissue samples. The individual's work history including working as a "mucker" at a specific "industrial" talc mine. METHODS: Ferruginous bodies in the tissue digests as well as asbestos fibers were found. A bulk sample of a talc containing product from that mine was also analyzed. DISCUSSIONS/CONCLUSIONS: The correlation between the unique asbestos mineral/fibrous content of the talc to which he was exposed and findings of the same type of asbestos found in his lung is discussed. The type of asbestos found (tremolite) is a "non-commercial" type of asbestos that has been identified in some talc deposits. Tremolite, like all forms of asbestos is a causative agent for mesothelioma-the disease from which this individual suffered.
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Amianto , Neoplasias Pulmonares , Mesotelioma Maligno , Mesotelioma , Masculino , Humanos , Anciano , Talco , Mesotelioma/inducido químicamente , Asbestos Anfíboles , Mesotelioma Maligno/complicaciones , Amianto/toxicidad , Neoplasias Pulmonares/inducido químicamente , PolvoRESUMEN
Librarians at a university had planned to check the collection prior to the library renovations that began in 2015. They had previous knowledge of the presence of a light greyish-white powder with an unpleasant odour (hereinafter referred to as 'powder') sprinkled between the pages of antiquarian books in the library archive. The purpose of this study was to identify this powder with the help of experts from both inside and outside the university. The powder was qualitatively analysed using gas chromatography with mass spectrometry after hexane extraction. The powder was examined under a polarised light microscope and a field-emission scanning electron microscope equipped with an energy-dispersive X-ray spectrometer. Benzene hexachloride (BHC) was detected in the powder. Talc was the most abundant particle in the powder. The powder also contained 0.52 wt% asbestos, which belonged to the tremolite-actinolite series. No other types of asbestos were detected. The powder was presumed to be a bulking agent for BHC, and its major constituent was talc. This is the first report on asbestos-containing insecticides.
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Insecticidas , Polvos , Talco , Insecticidas/análisis , Talco/química , Talco/análisis , Japón , Bibliotecas , Amianto/análisis , Cromatografía de Gases y Espectrometría de Masas , Odorantes/análisis , Libros , Hidrocarburos Clorados/análisisRESUMEN
The ability to modulate direct expanded product structures improves the versatility and range of product applications. The effect of nucleating agents, namely, talc and calcium carbonate (CC), on the expansion characteristics of pea starch extrudates as impacted by screw speed was explored. Pea starch blends with increasing levels of nucleating agents (0.25%, 1%, and 2%) at 18% moisture (w.b.) were extruded across a range of screw speeds (150, 250, 350, and 450 rpm). The water absorption index, water solubility index (WSI), expansion ratio (ER), unit density, and cell count were determined to evaluate the performance of nucleating agents. The nucleating efficiency of CC, as assessed by cell count, improved with increasing screw speeds. In contrast, the nucleating efficiency of talc was influenced by inclusion levels irrespective of screw speed. ER values ranged from 2.10 to 2.88, where higher nucleating agent inclusions and screw speeds corresponded with lower ER values. Increased nucleating agents and screw speeds corresponded to higher WSI values suggesting the nucleating agents promoted starch degradation. The nucleating agents appeared to promote flow instabilities indicated upon assessment of the extrudate surface. PRACTICAL APPLICATION: This study provides helpful information on the expanded extrudate structure of pea starch as influenced by screw speed and nucleating agents. These findings may help the food industry select processing parameters and appropriate nucleating agent inclusion levels when producing new expanded products with unique textures.
Asunto(s)
Manipulación de Alimentos , Almidón , Almidón/química , Talco , Pisum sativum , Agua/químicaRESUMEN
BACKGROUND: Secondary pneumothorax, which occurs most commonly in the elderly, is caused by underlying diseases. Cardiac dysfunction and other organ inefficiencies may render surgical repair impossible. Such non-operative and poor-risk cases are targets for pleurodesis, which involves the instillation of chemicals or irritants to the thoracic cavity through injection, bronchoscopic bronchial occlusion, or other procedures. Sterile graded talc has been used for pleurodesis mainly in Europe and the United States; however, only a few studies and case series investigating this topic have been published. This study evaluates the efficacy and safety of talc slurry pleurodesis. METHODS: Patients with inoperable secondary intractable pneumothorax, who were not candidates for surgical repair, were recruited. Four grams of sterilized talc was suspended in 50 mL of physiological saline and injected through a tube into the pleural cavity. Additional 50 mL of saline was subsequently injected through the same channel to clean the residual saline in the injection tube. Another additional talc instillation was allowed to control persistent air leakage. The primary endpoint was the proportion of drainage tube removal within 30 days after talc pleurodesis. RESULTS: Thirty-one patients were included in this study. In 23 out of 28 patients, the drainage tube could be removed within 30 days of talc instillation (82.1 %, 95 % CI = 63.1-93.9), exceeding the threshold of 36.0 % (p < 0.0001). The most common event was pain (11/28 patients, 39.3 %). CONCLUSIONS: Talc slurry pleurodesis is effective for intractable secondary pneumothorax, with minor side effects.
Asunto(s)
Neumotórax , Humanos , Anciano , Neumotórax/etiología , Neumotórax/terapia , Talco , Pleurodesia/métodos , DrenajeRESUMEN
Malignant pleural effusion (MPE) is a common complication of thoracic and extrathoracic malignancies and is associated with high mortality and elevated costs to healthcare systems. Over the last decades the understanding of pathophysiology mechanisms, diagnostic techniques and optimal treatment intervention in MPE have been greatly advanced by recent high-quality research, leading to an ever less invasive diagnostic approach and more personalized management. Despite a number of management options, including talc pleurodesis, indwelling pleural catheters and combinations of the two, treatment for MPE remains symptom directed and centered around drainage strategy. In the next future, because of a better understanding of underlying tumor biology together with more sensitive molecular diagnostic techniques, it is likely that combined diagnostic and therapeutic procedures allowing near total outpatient management of MPE will become popular. This article provides a review of the current advances, new discoveries and future directions in the pathophysiology, diagnosis and management of MPE.