Search results for "Hydrogen-ion concentration"
showing 10 items of 769 documents
Updating semen analysis: a subpopulation approach
2019
Endoluminal therapy of GERD with a new endoscopic suturing device
2005
Background Endoscopic, endoluminal therapy might be an alternative treatment option in light of the costs of proton pump inhibitor therapy and possible complications after laparoscopic surgery. The aim of the current study was to assess the efficacy and the safety of a new endoluminal suture device (ESD) in pig models and humans. Secondly, 3 and 6 months' follow-ups were performed, and possible complications and their management were evaluated. Methods In the preclinical phase of the study, suturing procedures were practiced and evaluated in 8 pig models (Erlanger Endo Trainer). In the clinical phase, 20 patients with mild esophagitis, small or no hiatal hernia, and signs of abnormal acid e…
Spontaneous gastroesophageal reflux and airway patency during the night in adult asthmatics
2000
Controversies still exist on the role of nighttime gastroesophageal reflux (GER) in precipitating nocturnal asthma. We tested the relationship between GER and nocturnal bronchoconstriction by continuously and simultaneously monitoring both respiratory resistances and esophageal pH in seven asthmatics with moderate to severe GER disease. Twenty-nine GER episodes were found during the study night lasting more than 5 min (LGER) and 72 not longer than 5 min (SGER). Both long (LGER) and short (SGER) gastroesophageal refluxes were able to maintain significantly higher lower respiratory resistances (RLR) at the resolution of each GER episode (RLR(e)) with respect to baseline values. RLR, expressed…
Unstimulated salivary flow rate, pH and buffer capacity of saliva in healthy volunteers
2004
Objectives: To assess the salivary flow rate, pH, and buffer capacity of healthy volunteers, and their relationships with age, gender, obesity, smoking, and alcohol consumption, and to establish the lower-end value of normal salivary flow (oligosialia). Methods: A prospective study was conducted in 159 healthy volunteers (age > 18 years, absence of medical conditions that could decrease salivary flow). Unstimulated whole saliva was collected during ten minutes, and salivary flow rate (ml/min), pH, and bicarbonate concentration (mmol/l) were measured using a Radiometer ABL 520. The 5 percentile of salivary flow rate and bicarbonate concentration was considered the lower limit of normality. R…
Fracture Mechanics of Collagen Fibrils: Influence of Natural Cross-Links
2013
AbstractTendons are important load-bearing structures, which are frequently injured in both sports and work. Type I collagen fibrils are the primary components of tendons and carry most of the mechanical loads experienced by the tissue, however, knowledge of how load is transmitted between and within fibrils is limited. The presence of covalent enzymatic cross-links between collagen molecules is an important factor that has been shown to influence mechanical behavior of the tendons. To improve our understanding of how molecular bonds translate into tendon mechanics, we used an atomic force microscopy technique to measure the mechanical behavior of individual collagen fibrils loaded to failu…
Prolonged in vitro exposure to white wines enhances the erosive damage on human permanent teeth compared with red wines.
2009
Abstract The aim of this in vitro study was to determine and compare the erosive potentials of red and white wines, exerted on enamel surfaces prepared from extracted human permanent teeth. European wines (50 red, 50 white wines) from different regions were purchased, and the pH values were measured. Eight wines with different pH values were selected. Enamel samples with an average surface area of 25 mm 2 were prepared from 25 extracted permanent teeth from male and female patients aged 40 to 65 years and incubated with wines for up to 24 hours; the amounts of released calcium were determined colorimetrically, and mean surface roughness was measured with a profilometer. A quantitative eleme…
Characteristics of sourdoughs and baked pizzas as affected by starter culture inoculums
2019
Previous investigations on pizza dough lactic acid bacteria (LAB) revealed that facultative heterofermentative species (FHS) were more represented than obligate heterofermentative species (OHS) within the Lactobacillus genus. Thus, the main hypothesis of this work was that facultative and obligate heterofermentative Lactobacillus species can impact differently the appreciation of baked pizza. The performances of different Lactobacillus, including L. sanfranciscensis, L. brevis and L. rossiae among OHS and L. plantarum, L. graminis and L. curvatus among FHS were tested in single or multiple combinations during pizza production. The values of pH, total titratable acidity and LAB levels indica…
An assessment of the human nail plate pH.
2010
<i>Purpose of Study:</i> To measure the pH of the surface of healthy nail plates. <i>Procedures:</i> The surface pH of human fingernails and big toenails was measured in vivo using a skin pH meter. The influence of washing, anatomical site (fingers/toes), side (left/right), digit (digits 1–5) and gender was determined. The pH of the nail interior was also measured. <i>Results:</i> The pH of the nail plate surface was around 5, with toenails having a significantly higher pH than fingernails. Immediately after hand washing, the nail surface pH increased significantly, from pH 5.1 ± 0.4 to 5.3 ± 0.5. However, this was not sustained with time, and the pH retu…
Esophageal abnormalities in morbidly obese adult patients.
2015
Abstract Background An increase in body mass index has been found to be associated with an increase in the prevalence of gastroesophageal reflux disease (GERD) symptoms, esophageal mucosal injury, and GERD complications. Few systematic studies with objective tests have evaluated esophageal disorders in the morbidly obese population. Objectives To define more precisely in morbidly obese people the incidence of esophageal symptoms and characterize the esophageal disorders using objective data. Setting University Hospital, Spain. Methods Two hundred twenty-four presurgical morbidly obese patients were submitted to a protocol including a clinical history and objective tests (endoscopy, stationa…
A functional study of the esophagus in patients with non-cardiac chest pain and dysphagia.
2015
Background/Aims: Nutcracker esophagus and non-specific motility disorders are the main causes of non-cardiac chest pain (NCCP), with gastroesophageal reflux in 60% of cases. Achalasia and diffuse esophageal spasm are the most frequent anomalies described in patients with dysphagia. The goal of this study was to evaluate the occurrence of esophageal body and lower esophageal sphincter motor abnormalities in patients with dysphagia, NCCP, or both. Materials and Methods: This study is a retrospective analysis of 716 patients with NCCP and/or dysphagia tested between January 1994 and December 2010. 1023 functional studies were performed, 707 of which were esophageal manometries, 225 esophageal …