Shear Bond Strength and Remineralisation Effect of a Casein Phosphopeptide-Amorphous Calcium Phosphate-Modified Glass Ionomer Cement on Artificial “Caries-Affected” Dentine

published_or_final_versio

Analysis of torque ripple of a spoke-type interior permanent magnet machine

This paper investigates the theoretical reasons behind the low torque ripple of a fractional-slot concentrated-winding (FSCW) spoke-type interior permanent-magnet (IPM) machine obtained via a genetic algorithm-based optimization. To better understand the torque performance of the IPMM, this paper uses the frozen permeability method to segregate the overall torque into four components-magnet torque, reluctance torque, cogging torque, and the torque caused by cross-magnetization. Equations and detailed procedures of the torque separation method are discussed in the paper. Analysis of the separated torque components reveals that the counteraction between ripples of different torques leads to the low torque ripple. At high-load conditions, the magnetic saturation alters the torque ripples caused by cross-magnetization to offset ripples of other components resulting in minimization of the overall torque ripple. A detailed parametric analysis of the geometric parameters was carried out to understand their effect in producing minimum torque ripple in the optimized design. In the end, a prototype was built and used for the verification of the torque separation method and the analytical findings based on it

Development and Optimization of a Mechanically Robust Novel Rotor Topology for Very-high-speed IPMSMs

Due to the trade-off between rotor mechanical strength and magnetic leakage, the high-speed capability of interior permanent magnet machines (IPMSM) is severely limited. This paper proposes a novel rotor topology capable of delivering 5 kW at 100,000 rpm using commercialized electrical steel laminations. By implementing the mechanical analysis in an iterative evolution process, two promising new topologies were developed. The first topology uses smooth compound curves (CC) to minimize the stress concentration and will be referred to as CC-type; the second topology is developed based on the CC-type with the aim to strengthen the structure further using the concept of a double-tied arch bridge (DAB) and referred as the DAB-type henceforward. After comparing the designs obtained from a detailed multiphysics optimization process, the DAB-type design was found to outperform the CC-type in all aspects, especially the mechanical robustness. This design was selected for experimental verification and a prototype was constructed. The mechanical and electromagnetic performances of the design were fully verified experimentally. The DAB-type prototype has achieved 2.31×105 rpm√kW, which is 1.5 times higher than other laminated rotor high-speed IPMSM designs found in the literature

Prevention of secondary caries using silver diamine fluoride treatment and casein phosphopeptide-amorphous calcium phosphate modified glass-ionomer cement

Objective: To study the effect of silver diamine fluoride (SDF) treatment and incorporating casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) into a glass-ionomer cement (GIC) to prevent secondary caries. Method: A cervical cavity was prepared on 32 premolars for the following restoration groups: group 1, conventional GIC restoration; group 2, SDF (38%) treatment and conventional GIC restoration; group 3, CPP-ACP (3%) modified GIC; and group 4, SDF treatment and CPP-ACP modified GIC. The restored teeth were thermal-cycled before undergoing a multi-species cariogenic biofilm challenge. The restored teeth were examined by micro-computed tomography (micro-CT), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDX) and Fourier transform infrared (FTIR) spectroscopy. Data were analyzed by two-way ANOVA. Results: Micro-CT determined outer lesion depths for groups 1–4 were: 123 ± 6 μm, 87 ± 7 μm, 79 ± 3 μm and 68 ± 5 μm respectively. An interaction effect on the outer lesion depth was found between the restorative materials and SDF treatment (p < 0.001). Both SDF treatment and modification with CPP-ACP had a significant effect on outer lesion depth (p < 0.001). SEM/EDX showed an increase of calcium and phosphorus at the root dentine adjacent to the restoration in groups 3 and 4 (CPP-ACP modified GIC). FTIR revealed that SDF treatment and CPP-ACP modified GIC had a significant effect on amide I-to-hydrogen phosphate ratio on the material-root interface (p = 0.001). Conclusion: SDF treatment and incorporation of CPP-ACP into GIC restorative material can prevent secondary root caries development. Clinical significance: The results provide useful information to dentists in formulating clinical management protocols and material when treating root caries.postprin

Lansoprazole for the prevention of recurrences of ulcer complications from long-term low-dose aspirin use

Background: The role of gastric acid suppression in preventing the recurrence of ulcer complications after the eradication of Helicobacter pylori infection in patients taking long-term low-dose aspirin is uncertain. Methods: We enrolled 123 patients who had ulcer complications after using low-dose aspirin continuously for more than one month and who had H. pylori infection. After the ulcers had healed and the H. pylori infection was eradicated, the patients were randomly assigned to treatment with 30 mg of lansoprazole daily or placebo, in addition to 100 mg of aspirin daily, for 12 months. The primary end point was the recurrence of ulcer complications. Results: During a median follow-up of 12 months, 9 of the 61 patients in the placebo group (14.8 percent), as compared with 1 of the 62 patients in the lansoprazole group (1.6 percent), had a recurrence of ulcer complications (adjusted hazard ratio, 9.6; 95 percent confidence interval, 1.2 to 76.1). Of these 10 patients, 4 had evidence of a recurrence of H. pylori infection and 2 had taken nonsteroidal antiinflammatory drugs before the onset of complications. Patients in the lansoprazole group were significantly less likely to have a recurrence of ulcer complications than patients in the placebo group (P=0.008). There was no significant difference in mortality between the two groups. Conclusions: In patients who had ulcer complications related to the long-term use of low-dose aspirin, treatment with lansoprazole in addition to the eradication of H. pylori infection significantly reduced the rate of recurrence of ulcer complications. Copyright © 2002 Massachusetts Medical Society.published_or_final_versio

A comparison of hepatitis B viral markers of patients in different clinical stages of chronic infection

Hepatitis B viral markers may be useful for predicting outcomes such as liver-related deaths or development of hepatocellular carcinoma. We determined the frequency of these markers in different clinical stages of chronic hepatitis B infection. We compared baseline hepatitis B viral markers in 317 patients who were enrolled in a prospective study and identified the frequency of these tests in immune-tolerant (IT) patients, in inactive carriers , and in patients with either hepatitis B e antigen ( HBeAg)- positive or HBeAg-negative chronic hepatitis or cirrhosis. IT patients were youngest (median age 27 years) and HBeAg- negative patients with cirrhosis were oldest (median age 58 years) (p = 0.03 to < 0.0001). The male to female ratio was similar both in IT patients and in inactive carriers, but there was a male preponderance both in patients with chronic hepatitis and in patients with cirrhosis (p < 0.0001). The A1896 precore mutants were most prevalent in inactive carriers (36.4%) and HBeAg- negative patients with chronic hepatitis (38.8%; p < 0.0001), and the T 1762/A1764 basal core promoter mutants were most often detected in HBeAg- negative patients with cirrhosis (65.1%; p = 0.02). Genotype A was detected only in 5.3% of IT patients, and genotype B was least often detected in both HBeAg-Positive patients with chronic hepatitis and cirrhosis (p = 0.03). The hepatitis B viral DNA levels were lowest in inactive carriers (2.69 log(10) IU/mL) and highest in IT patients (6. 80 log(10) IU/mL; p = 0.02 to < 0.0001). At follow-up, HBeAg-positive and HBeAg-negative patients with cirrhosis accounted for 57 of 64 (89.1%) liver-related deaths (p < 0. 0001). Differences in baseline hepatitis B viral markers were detected in patients in various clinical stages of hepatitis B virus infection. HBeAg-positive and HBeAg- negative patients with cirrhosis accounted for the majority of the liver-related fatalities

Three-day lansoprazole quadruple therapy for Helicobacter pylori-positive duodenal ulcers: a randomized contolled study

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Improved care of acute exacerbation of chronic obstructive pulmonary disease in two academic emergency departments

Background: Although several chronic obstructive pulmonary disease (COPD) practice guidelines have been published, there is sparse data on the actual emergency department (ED) management of acute exacerbation of COPD (AECOPD). Aims: Our objectives were to examine concordance of ED care of AECOPD in older patients with guideline recommendations and to evaluate whether concordance has improved over time in two academic EDs. Methods: Data were obtained from two cohort studies on AECOPD performed in two academic EDs during two different time periods, 2000 and 2005–2006. Both studies included ED patients, aged 55 and older, who presented with AECOPD, and cases were confirmed by emergency physicians. Data on ED management and disposition were obtained from chart review for both cohorts. Results: The analysis included 272 patients: 72 in the 2000 database and 200 in the 2005–2006 database. The mean age of the patients was 72 years; 50% were women and 80% white. In 2005–2006, overall concordance with guideline recommendations was high (for chest radiography, pulse oximetry, bronchodilators, all ≥ 90%), except for arterial blood gas testing (7% among the admitted) and discharge medication with systemic corticosteroids (42%). Compared to the 2000 data, the use of systemic corticosteroids in the ED improved from 53 to 77% [absolute improvement: 24%, 95% confidence interval (CI): 11–37%], and the use of antibiotics among the patients with respiratory infection symptoms improved from 56 to 78% (absolute improvement: 22%, 95% CI: 6–38%). Conclusions: Overall concordance with guideline-recommended care for AECOPD was high in two academic EDs, and some emergency treatments have improved over time