Search results for "Sound"
showing 10 items of 1845 documents
Effect of high power ultrasound on physical–chemical properties of polypropylene films aimed for food packaging: structure and surface features
2019
International audience; Biaxially oriented polypropylene (BOPP) coated with acrylic/polyvinylidene chloride (BOPPAcPVDC) and biaxially oriented coextruded polypropylene (BOPPcoex) films have been treated with high power ultrasound (HPUS) while submerged in water. Polymer structure and the surface morphology changes were noticed, and obtained results were correlated with the physical properties of tested materials. In anticipation of sonochemically enhanced reactions, physical–chemical profile of film samples was determined using thermogravimetric analysis, differential scanning calorimetry, Fourier-transform infrared spectroscopy, UV spectrophotometry and environmental scanning electron mic…
B-mode versus A-mode ultrasonographic measurements of mucosal thickness in vivo
2002
Abstract Objective: The objective of this study was to compare the measurement accuracy of A-mode and B-mode ultrasonographic assessments of palatal masticatory mucosal thickness in vivo. Study Design: Thickness of palatal masticatory mucosa in the molar region of 50 volunteers was measured once with a B-mode ultrasound device (10 MHz) combined with a standoff for intraoral applications. At identical reading points thickness was also assessed with an A-mode device (5 replicates) and by needle probing for determination of true thickness. Results: On average true thickness ranged between 2.9 and 3.3 mm (95% confidence intervals; median, 3.1 mm). B-mode ultrasonography overestimated truth by 0…
Recurrent wheezing during the first 3 years of life in a birth cohort of moderate-to-late preterm infants.
2019
Background Data addressing short- and long-term respiratory morbidity in moderate-late preterm infants are limited. We aim to determine the incidence of recurrent wheezing and associated risk and protective factors in these infants during the first 3 years of life. Methods Prospective, multicenter birth cohort study of infants born at 32+0 to 35+0 weeks' gestation and followed for 3 years to assess the incidence of physician-diagnosed recurrent wheezing. Allergen sensitization and pulmonary function were also studied. We used multivariate mixed-effects models to identify risk factors associated with recurrent wheezing. Results A total of 977 preterm infants were enrolled. Rates of recurrent…
Reliability of grading preoperative pancreatic neuroendocrine tumors on EUS specimens: a systematic review with meta-analysis of aggregate and indivi…
2022
Background and aims: Therapy and prognosis of pancreatic neuroendocrine tumors (PanNETs) are strictly related to the Ki-67 index, which defines tumor grading. The criterion standard for the assessment of grading of PanNETs is EUS-guided FNA (EUS-FBAFNA) or EUS-guided fine-needle biopsy sampling (EUS-FNB). Because data on diagnostic accuracy of EUS-FNA and EUS-FNB are heterogeneous, we aimed to analyze the variability in concordance between EUS grading and surgical grading. Methods: The MEDLINE, SCOPUS, and EMBASE databases were searched until November 2021 to identify studies reporting the concordance rate between EUS grading and surgical grading. The study was conducted in accordance with …
Diagnosis and treatment of autoimmune pancreatitis in Spain
2015
Aims: The analysis of laparoscopic operations in treatment of chronic pancreatitis. Patients & methods: In our clinic there were performed 32 laparoscopic interventions for chronic pancreatitis and its complications. Results: Laparoscopic interventions were performed in 32 cases: cystogastrostomy10, cystoduodenostomy2, cystojejunostomy3, cystectomy1, longitudinal laparoscopic pancreaticojejunostomy 2, the Beger procedure without proximal pancreatoenterostomy 2 and the Berne modification 10. In all the cases of laparoscopic procedures the communication of a cystwith the main pancreatic duct were confirmed by preoperative biochemical and cytologic analysis of cystic fluid taken under the ultr…
Transconjunctival sutureless 25-Gauge versus 20-Gauge standard vitrectomy: correlation between corneal topography and ultrasound biomicroscopy measur…
2009
Purpose: To determine the correlation between corneal shape changes and ultrasound biomicroscopy (UBM) findings at the sclerotomy sites in conventional 20-gauge (G) pars plana vitrectomy (PPV) and 25-G transconjunctival sutureless vitrectomy (TSV) and to compare the effectiveness of the two surgical methods. Design: Prospective, comparative, observational case series. Methods: Sixty consecutive eyes (60 patients) undergoing primary 3-port PPV. Thirty eyes (30 patients, group 20-G) were treated with 20-G standard PPV and 30 eyes (30 patients, group 25-G) with 25-G TSV. We compared healing of the sclerotomy sites in the two groups. We determined the correlation between corneal shape changes (…
Ultrasound-Guided Intramural Inoculation of Orthotopic Bladder Cancer Xenografts: A Novel High-Precision Approach
2013
Orthotopic bladder cancer xenografts are essential for testing novel therapies and molecular manipulations of cell lines in vivo. Current xenografts rely on tumor cell inoculation by intravesical instillation or direct injection into the bladder wall. Instillation is limited by the lack of cell lines that are tumorigenic when delivered in this manner. The invasive model inflicts morbidity on the mice by the need for laparotomy and mobilization of the bladder. Furthermore this procedure is complex and time-consuming. Three bladder cancer cell lines (UM-UC1, UM-UC3, UM-UC13) were inoculated into 50 athymic nude mice by percutaneous injection under ultrasound guidance. PBS was first injected b…
OP15.08: Intrauterine fetal brain damage in preeclamptic animal model: hemodynamic and histologic changes
2010
Impact of medical imaging on the epigenome – low-dose exposure in the course of computed tomography does not induce detectable changes of DNA-methyla…
2021
Computed tomography (CT) is a main contributor to artificial low-dose exposure. Understanding the biological effects induced by CT exposure and their dependency on the characteristics of photon spectra is essential for knowledge-driven risk assessment. In a previous gene expression study, we have identified upregulation of AEN, BAX, DDB2, EDA2R and FDXR after ex vivo exposure with single-energy CT and dual-energy CT (DECT). In this study, we focused on CT-induced changes of DNA methylation. This epigenetic modification of DNA is a central regulator of gene expression and instrumental in preserving genome integrity. Previous studies reported focal hypermethylation and global hypomethylation …
Biologic effects of ultrasound on liver cells of rat embryos.
1987
Experiments on the biologic effects of ultrasound (US) were carried out on rat embryos exposed for 120 s to a US beam showing features similar to those already employed for diagnostic purposes. Electron microscopic investigation of the liver parenchyma of rat embryos confirmed results obtained from adult guinea pigs with the same duration of exposure, i.e. diffuse vacuolization of cytoplasma and varying degrees of mitochondrial damage.