Silicosis en trabajadores con conglomerados artificiales de cuarzo

IntroductionSilicosis is a chronic progressive disease caused by inhalation of crystalline silica. Most cases develop in underground mine workers and in subjects involved in the extraction of natural stone (slate and granite). In view of the progressive emergence of new cases of silicosis in artificial quartz conglomerate workers, we performed a study to analyze the characteristics of silicosis produced by this new agent in Spain.MethodsThe study consisted of a series of 96 cases of silicosis diagnosed according to international criteria during the period 2010-2017. We analyzed clinical, radiological, pathological and functional characteristics.ResultsMean age of participants was 45 years; 55% had simple silicosis and 45% had complicated silicosis. Ten patients were diagnosed with accelerated silicosis, with a mean age of 33 years. Mean time of exposure to conglomerates was 15 years, and 77% had not used appropriate protection measures. Half of the patients were asymptomatic and presented different classic forms on chest X-ray and chest high-resolution computed tomography, along with ground-glass images. No lung function changes were recorded.ConclusionsSilicosis in artificial quartz conglomerate workers occurs in a young, actively employed population, a considerable percentage of whom present an accelerated form. They have few symptoms and no functional limitations. Protection measures are scarce. It is important to characterize these features to provide early diagnosis and implement the necessary preventive measures.     

Evaluation of surface roughness and bond strength of quartz fiber posts after various pre-treatments

Purpose. Debonding at the post-adhesive interface is a major problem for quartz fiber posts. The objective of this study was to evaluate surface roughness and bond strength of quartz fiber posts after various surface treatments. Materials and methods. Sixty-six quartz fiber posts were randomly divided into six experimental groups (n = 11) including group C, untreated (control); group SB, sandblasted; group SC, silica coated; group HF, hydrofluoric acid-etched; group N, Nd:YAG laser irradiated; group E, Er:YAG laser irradiated. Surface roughness of the posts was measured before and after pre-treatment. They were then bonded to resin cement and tensile bond strength was determined in a universal testing machine. Furthermore, two-way ANOVA and post hoc comparison tests (α = 0.05) were performed on all data. Results. The highest mean force value was observed in group SB and followed by group E. Tukey’s HSD test showed that there was no statistical difference between group SB and group E (p = 0.673). The highest mean roughness value was observed in group SB and a significant difference was found between group SB and all other groups (p < 0.001). This study reveals that sandblasting and Er:YAG laser irradiation provided a significant increase in bond strength between quartz fiber posts and resin cement. Conclusions. Sandblasting or Er:YAG laser-irradiation of the surface of the quartz fiber post before cementation is recommended for increasing retention.     

Phase Diagram of Sodium Hexametaphosphate and Poly(allylamine hydrochloride) Mixtures and In Situ Monitoring of Step‐by‐Step Deposition in This Polyelectrolyte System

The step‐by‐step deposition of poly(allylamine hydrochloride) (PAH) and sodium hexameta­phosphate (PSP) leads to coatings displaying interesting intumescent properties and is a fascinating model system to understand the fundamental mechanism behind such a deposition process. In this investigation, the deposition kinetics of (PAH‐PSP)_n is followed in situ by means of a quartz crystal microbalance with dissipation monitoring, as a function of NaCl concentration. The evolution of the film deposition is analyzed in detail and the data are compared with previous data obtained by ellipsometry on dried films. These results are also compared with the expectations from the PAH/PSP phase diagram. The (PAH‐PSP)_n films are also able to incorporate hexacyanoferrate anions with an amount of an incorporated redox probe reflecting the film thickness as obtained in the presence of eletrolyte solutions of increasing ionic strength. The in situ measurements and the electrochemical probe experiments reveal details of the film deposition mechanism that are not accessible by dry‐state characterization methods.

     

Silicosis in Artificial Quartz Conglomerate Workers

IntroductionSilicosis is a chronic progressive disease caused by inhalation of crystalline silica. Most cases develop in underground mine workers and in subjects involved in the extraction of natural stone (slate and granite). In view of the progressive emergence of new cases of silicosis in artificial quartz conglomerate workers, we performed a study to analyze the characteristics of silicosis produced by this new agent in Spain.MethodsThe study consisted of a series of 96 cases of silicosis diagnosed according to international criteria during the period 2010–2017. We analyzed clinical, radiological, pathological and functional characteristics.ResultsMean age of participants was 45 years; 55% had simple silicosis and 45% had complicated silicosis. Ten patients were diagnosed with accelerated silicosis, with a mean age of 33 years. Mean time of exposure to conglomerates was 15 years, and 77% had not used appropriate protection measures. Half of the patients were asymptomatic and presented different classic forms on chest X-ray and chest high-resolution computed tomography, along with ground-glass images. No lung function changes were recorded.ConclusionsSilicosis in artificial quartz conglomerate workers occurs in a young, actively employed population, a considerable percentage of whom present an accelerated form. They have few symptoms and no functional limitations. Protection measures are scarce. It is important to characterize these features to provide early diagnosis and implement the necessary preventive measures.     

Ultrathin films of charged polysaccharides assembled alternately with linear polyions

As a means of preparation of biocompatible molecular surfaces, an alternate assembly of charged polysaccharides and oppositely-charged synthetic polymers was conducted. Cationic chitosan was assembled alternately with anionic poly(sodium styrenesulfonate) (PSS) at pH 4. Regular film growth and its dependence on ionic strength were detected by the quartz crystal microbalance (QCM) method. Averaged film thicknesses for the chitosanCPSS layer were 15, 31, 46, and 69 A° , respectively, when 0, 0.25, 0.5, and 1 M of NaCl was contained in aqueous chitosan. Adsorption of chitosan did not reach saturation in 20 min at 0 M NaCl, while the adsorption became saturated within 6 min with 0.25 M NaCl. Anionic sodium chondroitin sulfate was also assembled in alternation with cationic poly(dimethyldiallylammonium chloride) (PDDA) at pH 6.5. The adsorption of chondroitin sulfate was less sensitive to ionic strength. Surface morphology of chitosan–PSS films was investigated by non-contact atomic force microscopy (AFM) observation. Maximum height difference and Ra value for a 1000 × 1000 nm area were 11 and 0.69 nm, respectively, indicating the formation of a molecularly flat surface by alternate layer-by-layer adsorption.     

Cefdinir-induced red stool and purple discoloration of nutritional formula: A case report

This case report describes a 4-year-old girl with food aversion who received three separate courses of cefdinir mixed with PediaSure®, an iron-fortified nutritional formula. The patient's stool turned red with variable onset during all three courses of treatment. Moreover, the PediaSure® formula turned purple after mixed with cefdinir, an interaction that has not been previously reported. We recommend that medication counseling for pediatric patients taking cefdinir include a mention of these possible discolorations.     

不同表面处理的纤维桩微拉伸粘接强度研究

目的:通过微拉伸粘接强度测试法测试在纤维桩表面经过6种不同的处理后与核树脂的粘接强度,探索何种表面处理方法能显著提高纤维桩与核树脂的粘接强度,为临床应用提供参考。方法:将30根石英纤维桩随机分成6组,每组5根。A组纤维桩表面涂布粘接剂,B组涂布硅烷处理剂,吹干后涂粘接剂,C组5%氢氟酸酸蚀30sec,流水冲洗吹干后处理同A组,D组5%氢氟酸酸蚀30sec,流水冲洗吹干后处理同B组,E组24%双氧水处理,后操作同A组,F组24%双氧水处理后操作同B组。在桩周分层固化核树脂,用低速锯沿纤维桩外周平行片切,再垂直粘接面片切成横截面约0.9mm×0.9mm的长方柱状试件,每组15个,用微拉伸粘接强度测试法测试纤维桩与核树脂的微拉伸粘接强度,体视显微镜观察断裂类型。结果:A组微拉伸粘接强度8.78±2.20MPa,B组9.35±1.92MPa,C组15.50±2.87MPa,D组22.98±3.24MPa,E组16.64±2.70MPa,F组24.88±3.9 0MPa。用氢氟酸酸蚀的C组和D组和用双氧水处理的E组和F组的微拉伸粘接强度明显高于A组B组(P<0.05)。用氢氟酸酸蚀后再硅烷化处理的D组比C组、用双氧水处...     

根管壁表面处理和不同粘结系统对纤维桩粘结强度的影响

目的研究不同根管牙本质壁表面处理方法及使用不同粘结系统对石英纤维桩粘结时根管不同部位剪切粘结强度的影响。方法36颗完整离体上中切牙唇侧釉牙骨质界冠方2.0mm处截冠后行根管治疗。专用钻根管预备,酸蚀后,分别采用生理盐水60s(对照组)、10%次氯酸钠(NaOCl)溶液60s、17%乙二胺四乙酸(EDTA)溶液60s与5.25%NaOCl溶液60s联用的根管壁处理方法,结合DUOLINK树脂粘结剂或LUXACORE核材料按析因设计配对行石英纤维桩粘结修复。包埋并切片后,置于MTSSynergie综合测试仪上采用1mm微推出法对不同根管段行剪切粘结实验,记录数值并行统计学分析。结果剪切粘结强度依次为(MPa):6.29±3.77,9.67±3.94,8.07±3.59,2.59±2.04,5.46±3.09,5.80±3.56。10%NaOCl处理组、17%EDTA溶液与5.25%NaOCl溶液联用组剪切粘结强度均明显增强(P<0.0001);DUOLINK树脂粘结剂组剪切粘结强度优于LUXACORE核材料组(P<0.0001);所有实验组中,剪切粘结强度自根管冠方向根方逐渐减弱。结论单独使用10%NaOCl溶液、17%EDTA溶液与5.25%NaOCl溶液联用处理根管壁增强了石英纤维桩修复根管不同部位尤其是根尖的剪切粘结强度。     

Voltage-dependent K+-channel Responses during Activation and Damage in Alveolar Macrophages Induced by Quartz Particles

nflammatory response during damage and necrosis in AMs induced by exposure to quartz particle. K+ channels do not contribute to the membrane damage of AMs.     

矿物药白石英优质矿产资源筛选及XRD Fourier指纹图谱研究

目的 分析不同产地白石英样品中矿物成分及含量,评价不同产地白石英样品的质量,筛选白石英优质矿产资源,并建立白石英X射线衍射（XRD）Fourier特征指纹图谱。方法 通过偏光显微及XRD分析不同样品矿物成分及其含量,以结晶度和石英含量作为评价指标。采用粉末XRD对白石英样品进行分析,建立中药白石英XRD Fourier特征指纹图谱,并进行模糊聚类分析、主成分分析和相似性评价。结果 偏光显微分析结果显示,不同产地白石英样品在结晶度上有明显不同。物相分析结果显示白石英样品主要成分为石英和正长石,且大多数样品含有钠长石。不同产地白石英中石英质量分数为91.2%~99.4%,其中浙江省安吉县章村镇和安徽省绩溪县扬溪镇白石英中石英质量分数最高,均为99.4%,浙江安吉县杭垓镇产白石英中石英质量分数为91.2%。建立了以12个共有峰为特征指纹信息的白石英XRD Fourier指纹图谱分析方法,其XRD Fourier指纹图谱的相似度为0.993～1.000。结论 在所采集的样品中,白石英药材品质总体较好,石英质量分数均在90.0%以上,其中浙江省安吉县章村镇和安徽省绩溪县扬溪镇所产白石英品质最好,其次为福建永安小陶镇和江苏新沂阿湖镇产白石英。偏光显微特征观察和XRD Fourier指纹图谱分析法可用于白石英的鉴定与分析。