Oxalic acid is found in dietary sources (such as coffee, tea, and chocolate) or is produced by the intestinal microflora from metabolic precursors, like ascorbic acid. In the human intestine, oxalate may combine with calcium, sodium, magnesium, or potassium to form less soluble salts, which can cause pathological disorders such as hyperoxaluria, urolithiasis, and renal failure in humans. In thi...

Airway obstruction in asthma and chronic obstructive pulmonary disease (COPD) is often associated with lung hyperinflation. In this review, we examine the mechanisms that may cause functional residual capacity (FRC), residual volume (RV) and total lung capacity (TLC) to increase during acute and chronic airway obstruction. Normally, FRC at rest is determined by the static characteristics of the...

BACKGROUND Fibre reinforced composite bars (FRC) have applications as bonded retainers, space maintainers and anchorage/movement units. However, the bond strength of attachments to FRC anchorage bars is unknown. AIMS To compare the shear bond strengths of brackets bonded immediately to FRCs with different orthodontic adhesive systems and bonded with the same adhesives after a 48-hour delay, a...

AIM The purpose of this case report is to describe the clinical procedure for fabricating fiber-reinforced composite (FRC) onlay composite resin restorations using a FRC as the substructure. BACKGROUND A variety of therapeutic modalities are available to restore teeth with moderate coronal defects in the posterior region of the mouth. For patients who refuse complete crown restorations or whe...

Fiber-reinforced concrete (FRC) has been proved to be a competitive solution for structural purposes. Extensive research highlighted the benefits of adding fibers on post-cracking strength, reduced crack spacing and width, improved durability, among others. However, these aspects are related serviceability limit states, significant work remains done in terms ultimate state behavior FRC members....

At birth, the initiation of pulmonary gas exchange is dependent on air entry into the lungs, and recent evidence indicates that pressures generated by inspiration may be involved. We have used simultaneous plethysmography and phase-contrast X-ray imaging to investigate the contribution of inspiration and expiratory braking maneuvers (EBMs) to lung aeration and the formation of a functional resi...

OBJECTIVES This study aimed to investigate the effect of surface treatment with Er:YAG laser on shear bond strength (SBS) of orthodontic brackets to fiber-reinforced composite (FRC). STUDY DESIGN Ninety human premolars were randomly divided into six groups of 15. FRC bars were bonded to the teeth with a flowable composite (FC) and then underwent following treatments. In group 1 no further tre...

background: the aim of this study was to evaluate the response of common sized fiber-reinforced composites (frcs) to different deflections due to bending forces and comparing it with stainless steel (ss) wires. materials and methods: in this experimental study, two frc groups with 0.75 mm and 1.2 mm diameters (everstick ortho, stick tech, finland) and three ss groups with 0.016 × 0.022 inch, 0....

The advantages of determining thoracic gas volume and functional residual capacity (FRC) via the body plethysmograph have long been recognized.1 In our laboratory, we have found that employing a standard X-Y-T recorder in conjunction with the plethysmograph enables us to determine a more precise measurement of FRC from our measurement of thoracic gas volume. During plethysmographic study, the t...

We studied 11 mild asthmatics to verify whether the mechanisms of hyperinflation in asthma could be inhibited or overcome by passively changing lung volumes. On day 1, we induced a fall in forced expiratory volume in one second (FEV1) of 30-60% by methacholine inhalation and measured the resulting increase in FRC (delta FRC). The delta FRC was 729 +/- 378 ml (mean +/- SD). On day 2, with the su...