The effect of amalgam bonding on the stiffness of teeth weakened by cavity preparation.

OBJECTIVE: The objective of this study is to evaluate the effect of amalgam bonding on the stiffness of teeth weakened by cavity preparation. METHODS: Strain gages were bonded to maxillary premolars. The rigidity was tested by applying a load to a sequence of sound, prepared and restored teeth as follows: sound tooth, MOD preparation, amalgam restoration, amalgam removed recovering the MOD preparation, bonded amalgam restoration, bonded amalgam removed recovering the MOD preparation, bonded composite restoration. The relative stiffness (RS) and relative deformation (RD) of each condition for each cusp to that of the sound tooth was determined. RESULTS: The premolar cusps were deformed 1.80, 2.14, and 2.32 times more than the cusps of the sound tooth for the three succeeding MOD preparations. For these three preparations, the stiffness of the premolar cusps was 0.58, 0.48, and 0.46 relative to a stiffness of 1.00 for the sound tooth. The deformation was 1.77, 1.27, and 1.16 for the non-bonded amalgam, the bonded amalgam, and the bonded composite, respectively, corresponding to a mean RS of 0.59, 0.80, and 0.88. The calculated mean stiffness parameter C (standard deviation) was 2.6% (6.9) for the amalgam restoration, 62.5% (12.8) for the bonded amalgam restoration, and 77.8% (15.8) for the bonded composite restoration. The stiffness parameter C measured the extent to which the procedure returned the stiffness of the restored tooth to the original stiffness of the intact tooth (100%). SIGNIFICANCE: Cavity preparation reduced the stiffness and weakened the tooth. Restoring the prepared tooth with unbonded amalgam did not restore the lost tooth stiffness. Restoring the prepared tooth with bonded amalgam or with bonded composite recovered a significant portion of the lost tooth stiffness. It was concluded that bonding amalgam to tooth structure could partly restore the strength and rigidity lost by the cavity preparation. This might lead to a reduction in cuspal flexure and the incidence of tooth fracture due to fatigue.     

Enhanced healing efficacy of an optimized gabapentin-melittin nanoconjugate gel-loaded formulation in excised wounds of diabetic rats

The present study aimed to design and optimize, a nanoconjugate of gabapentin (GPN)-melittin (MLT) and to evaluate its healing activity in rat diabetic wounds. To explore the wound healing potency of GPN-MLT nanoconjugate, an in vivo study was carried out. Diabetic rats were subjected to excision wounds and received daily topical treatment with conventional formulations of GPN, MLT, GPN-MLT nanoconjugate and a marketed formula. The outcome of the in vivo study showed an expedited wound contraction in GPN-MLT-treated animals. This was confirmed histologically. The nanoconjugate formula exhibited antioxidant activities as evidenced by preventing malondialdehyde (MDA) accumulation and superoxide dismutase (SOD) and glutathione peroxidase (GPx) enzymatic exhaustion. Further, the nanoconjugate showed superior anti-inflammatory activity as it inhibited the expression of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). This is in addition to enhancement of proliferation as indicated by increased expression of transforming growth factor-β (TGF- β), vascular endothelial growth factor-A (VEGF-A) and platelet-derived growth factor receptor-β (PDGFRB). Also, nanoconjugate enhanced hydroxyproline concentration and mRNA expression of collagen type 1 alpha 1 (Col 1A1). In conclusion, a GPN-MLT nanoconjugate was optimized with respect to particle size. Analysis of pharmacokinetic attributes showed the mean particle size of optimized nanoconjugate as 156.9 nm. The nanoconjugate exhibited potent wound healing activities in diabetic rats. This, at least partly, involve enhanced antioxidant, anti-inflammatory, proliferative and pro-collagen activities. This may help to develop novel formulae that could accelerate wound healing in diabetes.     

Fabrication of a graphene-based sensor to detect the humidity and the temperature of a metal body with imprecise data analysis

Graphene is a 2D material with remarkable properties. The present study demonstrates the fabrication of a graphene-based sensor for measuring the temperature and humidity of a metal body. The graphene sensor was fabricated by depositing a thin film of graphene nanoparticles between silver electrodes (separated by ∼50 μm) on a glass substrate. The graphene thin film was characterized by XRD, Raman spectroscopy and UV-vis techniques. The capacitance and resistance for both the relative humidity (in the range of 0–100% RH) and temperature (in the range of 230–310 K) were measured using an LCR meter at 1 kHz in a controlled chamber. The graphene-based sensor expressed high sensitivity with fast response and recovery times for both humidity and temperature with long stability and low hysteresis curves. The sensor was also tested on a metal body, which expressed a good response time. Moreover, the measured data of capacitance and resistance was analyzed with classical and neutrosophic analysis as an application of modern material statistics. It was observed that neutrosophic analysis is more flexible for analyzing the capacitance and resistance of the fabricated sensor.

Graphene is a 2D material with remarkable properties.     

Contrast enhanced MRI and Diffusion Weighted Imaging (DWI) in the evaluation of renal cell carcinoma and differentiation of its subtypes

Objective

The prognosis of different histologic subtypes of RCC varies and affects management. Patients with chromophobe or papillary RCC have better prognosis than those with clear cell RCC. The aim of our work was to study the utility of DCE and DWI in the preoperative prediction of renal cell carcinoma subtypes, using histopathology as a gold standard method of diagnosis.

Autochthonous hepatitis E in Southwest England: natural history, complications and seasonal variation, and hepatitis E virus IgG seroprevalence in blood donors, the elderly and patients with chronic liver disease

AIMS: To report the natural history of autochthonous hepatitis E and hepatitis E virus (HEV) IgG seroprevalence in Southwest England. METHODS: Patients with unexplained hepatitis were tested for hepatitis E and cases followed until recovery or death. Five hundred blood donors, 336 individuals over the age of 60 years and 126 patients with chronic liver disease were tested for HEV IgG. RESULTS: Forty cases of autochthonous hepatitis E (genotype 3) were identified. Hepatitis E was anicteric in 25% of cases and usually caused a self-limiting hepatitis predominantly in elderly Caucasian males. Six of 40 had a significant complication and three patients died, two of who had previously undiagnosed cirrhosis. Hepatitis E shows a seasonal variation with peaks in the spring and summer and no cases in November and December. HEV IgG prevalence increases with age, is more common in men and is 16% in blood donors, 13% in patients with chronic liver disease and 25% in individuals over 60 years. CONCLUSION: Autochthonous hepatitis E is more common than previously recognized, and should be considered in the differential diagnosis in patients with hepatitis, whatever their age or travel history. It carries a significant morbidity and when seen in the context of chronic liver disease carries an adverse prognosis.     

Assessing Walking and Cycling Environments in the Streets of Madrid: Comparing On-Field and Virtual Audits

Audit tools are useful for exploring the urban environment and its association with physical activity. Virtual auditing options are becoming increasingly available potentially reducing the resources needed to conduct these assessments. Only a few studies have explored the use of virtual audit tools. Our objective is to test if the Madrid Systematic Pedestrian and Cycling Environment Scan (M-SPACES) discriminates between areas with different urban forms and to validate virtual street auditing using M-SPACES. Three areas (N?=?500 street segments) were selected for variation in population density. M-SPACES was used to audit street segments physically and virtually (Google Street View) by two researchers in 2013–2014. For both physical and virtual audits, all analyzed features score significantly different by area (p?<?0.05). Most of the features showed substantial (ICC?=?0.6–0.8) or almost perfect (ICC?≥?0.8) agreement between virtual and physical audits, especially neighborhood permeability walking infrastructure, traffic safety, streetscape aesthetics, and destinations. Intra-rater agreement was generally acceptable (ICC?>?0.6). Inter-rater agreement was generally poor (ICC?<?0.4). Virtual auditing provides a valid and feasible way of measuring residential urban environments. Comprehensive auditor training may be needed to guarantee good inter-rater agreement.