Association between high vancomycin minimum inhibitory concentration and clinical outcomes in patients with methicillin-resistant Staphylococcus aureus bacteraemia - A retrospective cohort study

European Journal of Clinical Microbiology & Infectious Diseases - The purpose of this study is to determine the role of high (≥ 1.5 mg/L) vancomycin minimum inhibitory concentration...     

A novel CAD/CAM resin composite block with high mechanical properties

ObjectiveTo determine the mechanical properties of a newly-developed CAD/CAM resin composite block and compare with other resin composite blocks and a polymer-infiltrated ceramic block.MethodsExperimental composite block was formulated by our proprietary resin and filler technologies and cured via Hot Isostatic Pressing (HIP). Bar-shaped specimens (1 × 4×12 ? 13 mm, n = 10) for flexural strength, flexural modulus and modulus of resilience were sectioned from block materials and measured in accordance to modified ISO-6872. Cylinder specimens for compressive strength (2 × 4 mm, n = 8) and for diametral tensile strength (6 × 3 mm, n = 8) were milled from the block materials and tested according to ASTM-D695 and ANSI/ADA-Specification #27, respectively. Block specimens (5 mm, n = 3) for Vickers hardness were polished and measured for five indentations on each specimen. The data was analyzed by one-way ANOVA and post-hoc Tukey tests (p ≤ 0.05).ResultsExperimental composite block showed higher or significantly higher flexural strength, flexural modulus, modulus of resilience, compressive strength, diametral tensile strength and Vickers hardness than the other commercially available block materials except Vita Enamic for flexural modulus and hardness and Cerasmart for modulus of resilience. Some positive correlations were observed among the different mechanical properties.SignificanceNew composite block exhibited higher mechanical properties as compared to commercially available composite block materials. Superior mechanical properties for resin composite block materials were obtained by composite and curing processing technologies. Resin composite blocks with higher mechanical properties are good options for the fabrication of CAD/CAM indirect restorations.     

Electrochemical performance of nano-sized LiFePO4-embedded 3D-cubic ordered mesoporous carbon and nitrogenous carbon composites

Herein, we report a single-step synthesis, characterization, and electrochemical performance of nano-sized LiFePO₄ (LFP)-embedded 3D-cubic mesoporous carbon (CSI-809) and nitrogenous carbon (MNC-859) composites. Furthermore, in order to investigate the effects of both CSI-809 and MNC-859 on the electrochemical characteristics of LFP, a systematic study was performed on the morphology and microstructure of the composites, viz., LFP/CSI-809 and LFP/MNC-859, using XRD, FE-SEM, FT-Raman, and BET surface area analyses. Among these composites, LFP/MNC-859 exhibited better electrochemical performance with higher specific capacity and rate capability as compared to those of LFP/CSI-809. In addition, even after 100 cycles, LFP/MNC-859 retained 97% of its initial discharge capacity at 1C rate. The enhanced electrochemical performance of the nano-sized LFP-embedded MNC-859 can be attributed to the conductive nitrogenous carbon and mesoporosity, which facilitate electrolyte diffusion, and improved conductivity of the advanced LFP-nitrogenous porous carbon matrix.

Nano-sized LiFePO₄-embedded nitrogenous ordered mesoporous carbon composite cathode facilitate electronic conductivity and significantly enhances Li-ion diffusion and retains 97% of the initial discharge capacity at 1C rate even after 100 cycles.     

Association of Helicobacter pylori with oral potentially malignant disorders and oral squamous cell carcinoma—a systematic review and meta-analysis

Objective

To assess any potential association between Helicobacter pylori and oral squamous cell carcinoma/oral potentially malignant disorders.

Materials and methods

Data mining was done using PubMed, Cochrane Library, and SCOPUS databases. The search included articles published up to May 2019. Newcastle-Ottawa scale was used to score the quality of the included articles. Data including the type of study, the sample population, the type of oral lesion, and the resulting statistical data were extracted.

Results

Out of 131 screened articles, only 15 articles fulfilled the eligibility criteria. Among the 15 studies, 9 focused on oral squamous cell carcinoma and 6 focused on oral potentially malignant disorders. Eight out of the 9 oral squamous cell carcinoma studies were included in the meta-analysis. Forest plot was generated using the odds ratio and confidence intervals calculated for each of the included studies. Due to the lack of sufficient studies, the meta-analysis was not performed for oral potentially malignant disorders.

Conclusion

Due to the contradictory results of the included studies, it was not possible to make any conclusive statement on the potential association of H. pylori with oral squamous cell carcinoma. The variations in the methodology, especially the differences in the sensitivity/specificity of the diagnostic modalities could be the cause for differential results.

Clinical relevance

Although the association of H. pylori with oral squamous cell carcinoma could not be confirmed, it is vital to reduce the excess oral microbial load, especially in patients exhibiting oral mucosal changes with no history of associated risk factors.

     

Evaluating the image quality of cone beam CT acquired during rotational delivery

Objective:

The aim of this work was to evaluate the quality of kilovoltage (kV) cone beam CT (CBCT) images acquired during arc delivery.

Methods:

Arc plans were delivered on a Catphan^® 600 phantom (The Phantom Laboratory Inc., Salem, NY), and kV CBCT images were acquired during the treatment. The megavoltage (MV) scatter effect on kV CBCT image quality was evaluated using parameters such as Hounsfield unit (HU) accuracy, spatial resolution, contrast-to-noise ratio (CNR) and spatial non-uniformity (SNU). These CBCT images were compared with reference scans acquired with the same acquisition parameters without MV “beam on”. This evaluation was carried out for different photon beams (6 and 15 MV), arc types (half vs full arc), static field sizes (10 × 10 and 25 × 25 cm²) and source-to-imager distances (SID) (150 and 170 cm).

Results and Conclusion:

HU accuracy, CNR and SNU were considerably affected by MV scatter, and this effect was increased with increasing field size and decreasing photon energy, whereas the spatial resolution was almost unchanged. The MV scatter effect was observed to be more for full-rotation arc delivery than for half-arc delivery. In addition, increasing the SID resulted in decreased MV scatter effect and improved the image quality.

Advances in knowledge:

Nowadays, volumetric modulated arc therapy (VMAT) is increasingly used in clinics, and this arc therapy enables us to acquire CBCT imaging simultaneously. But, the main issue of concurrent imaging is the “MV scatter” effect on CBCT imaging. This study aims to experimentally quantify the effect of MV scatter on CBCT image quality.