Braiding Thermoplastic and Glass Fibers in Composite Dental Post Improves Their Mechanical Compatibility,In Vitro Experiment

Mechanical compatibility with the human dentin is a considerable issue when fabricating dental fiber posts. To this purpose, this study introduces a new method of fabricating compatible dental posts using braiding techniques of thermoplastic fibers (matrix) with glass fibers (reinforcement). Fifty fiber-reinforced composite (FRC) posts of thermoplastic yarns polypropylene (PP) braided with continuous filaments glass fibers (GFs) for reinforcement, varying in fiber volume fraction (FVF), and core types are fabricated and tested. Posts are performed using a braiding machine, and braids are placed in an aluminum mold. The filled mold is playced inside an oven at the melting temperature of the polypropylene to produce the final post’s shape. An ultrasonic test is conducted to measure the shear modulus and Young’s modulus of FRC post specimens by measuring the velocities of both the P-wave and S-wave. In order to ensure the accuracy of the measurements, each sample is measured three times, and then the means and standard deviations of each sample are calculated before analyzing the test results using the means of two steps, namely, clustering and comparing the P and R² values of each cluster, which revealed that FVF, fiber mass, and core type of the specimen had a significant effect on the resulted Young’s and shear modulus. The results indicate that the proposed method can fabricate competitive dental posts with regard to different fabricating variables. The samples show Young’s modulus ranges of from 10.08 GPa to 31.83 GPa. The following tested hypothesis is supported: the braiding technique of thermoplastic fibers with glass fibers will improve the mechanical compatibility of the resulting posts (ex vivo).     

Surface Roughness Evaluation in Thin EN AW-6086-T6 Alloy Plates after Face Milling Process with Different Strategies

Lightweight alloys made from aluminium are used to manufacture cars, trains and planes. The main parts most often manufactured from thin sheets requiring the use of milling in the manufacturing process are front panels for control systems, housing parts for electrical and electronic components. As a result of the final phase of the manufacturing process, cold rolling, residual stresses remain in the surface layers, which can influence the cutting processes carried out on these materials. The main aim of this study was to verify whether the strategy of removing the outer material layers of aluminium alloy sheets affects the surface roughness after the face milling process. EN AW-6082-T6 aluminium alloy thin plates with three different thicknesses and with two directions relative to the cold rolling process direction (longitudinal and transverse) were analysed. Three different strategies for removing the outer layers of the material by face milling were considered. Noticeable differences in surface roughness 2D and 3D parameters were found among all machining strategies and for both rolling directions, but these differences were not statistically significant. The lowest values of Ra = 0.34 µm were measured for the S#3 strategy, which asymmetrically removed material from both sides of the plate (main and back), for an 8-mm-thick plate in the transverse rolling direction. The highest values of Ra = 0.48 µm were measured for a 6-mm-thick plate milled with the S#2 strategy, which symmetrically removed material from both sides of the plate, in the longitudinal rolling direction. However, the position of the face cutter axis during the machining process was observed to have a significant effect on the surface roughness. A higher surface roughness was measured in the areas of the tool point transition from the up-milling direction to the down-milling direction (tool axis path) for all analysed strategies (Ra = 0.63–0.68 µm). The best values were obtained for the up-milling direction, but in the area of the smooth execution of the process (Ra = 0.26–0.29 µm), not in the area of the blade entry into the material. A similar relationship was obtained for analysed medians of the arithmetic mean height (Sa) and the root-mean-square height (Sq). However, in the case of the S#3 strategy, the spreads of results were the lowest.     

The epidemiology of non-alcoholic steatohepatitis (NASH) in the United States between 2010-2020: a population-based study

Introduction and objectivesNon-alcoholic steatohepatitis (NASH) is a severe form of non-alcoholic fatty liver disease (NAFLD) that can progress to liver cirrhosis, liver failure and hepatocellular carcinoma. It is the second leading cause of liver transplant in the US. We aim to investigate the prevalence, demographics and risk factors NASH patients in the US.Patients and methodsWe used a large database (Explorys IBM) that aggregates electronic health records from 26 nationwide healthcare systems. We identified adults with NASH between 2010-2020. Demographics including age, gender and race were collected. NASH risk factors including Diabetes Millets (DM), Hyperlipidemia (HLD), Hypertension (HTN) and Obesity were also collected. Cochran-Armitage test was used to assess the statistical significance of year-by-year trend. Univariable and multivariable logistic regression were used to estimate the odds ratio (OR) of risk factors.ResultsNASH annual prevalence rate increased from 1.51% in 2010 to 2.79% in 2020 (p < 0.0001). The proportion of patients with NASH by gender was 54.1% female vs 45.9% male (OR 1.04 [0.91-1.11]). Caucasian had higher odds of NASH than non-Caucasian (OR 1.42 [1.31-1.54]). NASH is strongly associated with DM and obesity (OR 18.61 [17.35-19.94]) and (OR 20.97 [17.87-23.21]), respectively. Other components of metabolic syndrome were associated with NASH to a lesser degree; HTN (OR 3.24 [3.20-3.28]) and HLD (OR 4.93 [4.85-4.01]).ConclusionThe prevalence of NASH has significantly increased in the US in the last decade. This is likely related to the increased prevalence of risk factors as well as increased awareness of the disease.     

Infection in systemic lupus erythematosus patients

BackgroundInfection is a leading cause of morbidity, mortality and hospital admission in systemic lupus erythematosus (SLE) patients.Aim of the workTo study infection in SLE patients regarding site of infection, pathogenic organism, hospitalization and/or intensive care unit (ICU) admission.Patients and methodsThis study included 79 patients. SLE disease activity index (SLEDAI-2K) and damage index were evaluated. Detailed information about the site of infection and pathogens were reported.Results71 females and 8 male patients (F:M 8.9:1), with a mean age of 29 ± 9.6 years (17–55 years) and disease duration of 5.9 ± 5.7 years, 55 (69.6%) patients had infection at time of study while 24 (30.4%) did not. The SLEDAI-2 k and damage index were significantly higher in SLE patients with infection (14.2 ± 11.8 and 3.7 ± 3.7) compared to those without infection (5.9 ± 5.03 and 1.8 ± 1.3) (p = 0.03 and p = 0.045 respectively). Those with infection had a shorter disease duration (4.9 ± 5.2 vs 8.3 ± 6.2; p = 0.005), received more cyclophosphamide (56.4% vs 16.7%; p = 0.001), higher erythrocyte sedimentation rate (ESR) (75.5 ± 27.1 vs 35.8 ± 24.7 mm/1^sthr) (p < 0.0001) and consumed complement (C3) (71.1 ± 28.4 vs 97.2 ± 28.2; p < 0.0001). 17/55 (30.9%) had more than one site of infection and 46/55 (83.6%) required hospital admission. 17 (30.9%) of hospitalized patients were transferred to the ICU. The main pathogenic organisms were bacterial (40%), fungal (27.3%), viral (10.9%) and unconfirmed in 21.8%. Chest was the commonest site (40%) followed by the skin (34.4%), oropharynx (25.5%) and urinary tract (20%).ConclusionInfection is an important cause of hospital and ICU admission in SLE patients. Early disease, disease activity and damage, cyclophosphamide, ESR and consumed C3 were associated with infection in SLE.     

Discovery of Novel Peptidomimetics as Irreversible CHIKV NsP2 Protease Inhibitors Using Quantum Mechanical‐Based Ligand Descriptors

Chikungunya virus (CHIKV) is a mosquito‐borne alphavirus. Recent outbreaks of CHIKV infections have been reported in Asia, Africa, and Europe. The symptoms of CHIKV infection include fever, headache, nausea, vomiting, myalgia, rash, and chronic persistent arthralgia. To date, no vaccines or selective antiviral drugs against this important emerging virus have been reported. In this study, the design, synthesis, and antiviral activity screening of new topographical peptidomimetics revealed three potential prototype agents 3a , 4b, and 5d showing 93–100% maximum inhibition of CHIKV replication in cell‐based assay having EC₉₀ of 8.76–9.57 μg/mL. Intensive molecular modeling studies including covalent docking, lowest unoccupied molecular orbital energies, and the atomic condensed Fukui functions calculations strongly suggested the covalent binding of peptidomimetics 3a , 4b, and 5d to CHIKV nsP2 protease leading to permanent enzyme inactivation via Michael adduct formation between α/β‐unsaturated ketone functionality in our designed peptidomimetics and active site catalytic cysteine1013. Furthermore, small molecular weight peptidomimetics 3a and 4b satisfied the Lipinski rule of five for drug‐likeness and showed promising intestinal absorption and aqueous solubility via computational admet studies making them promising hits for further optimization.     

Oral and ocular manifestations in Sjögren's syndrome

OBJECTIVE: Little is known about the relationship between lachrymal and salivary gland involvement in Sj?gren's syndrome (SS). It is also of interest to know which eye test contributes most to the diagnosis of SS. We investigated the performance of different tear tests and how these tests relate to common serologic and salivary tests in SS. METHODS: In patients suspected of SS, the tear breakup time and the tear mucus score were evaluated in addition to the routine tests. Eighty consecutive patients were included, categorized into primary SS (pSS), secondary SS (sSS), and negative for SS. RESULTS: The tear breakup time and mucus score both performed insufficiently in diagnosing SS, in contrast to the Rose Bengal score. In pSS and sSS patients, a clear correlation was noted between tear and saliva quality and secretion rate, and between the Rose Bengal score and parotid sialography. Increased Rose Bengal scores also correlated significantly with hyperglobulinemia and presence of SSB antibodies in serum, with duration of subjective eye dryness, and with decreased tear gland function. CONCLUSION: The Rose Bengal score remains the eye test of choice having the highest specificity for SS. Hyperglobulinemia and especially positive SSB serology may warrant close monitoring of the eyes, since these serum findings appear to relate to the severity of ocular surface damage. Theoretically, a positive evaluation of either the ocular or oral component, in addition to positive serology or histopathology, could be sufficient to diagnose the syndrome for clinical purposes.