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43,445 result(s) for "Ultrasonic methods"
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A Randomized Trial of Focused Ultrasound Thalamotomy for Essential Tremor
In this randomized, sham-controlled trial, MRI-guided focused ultrasound thalamotomy reduced hand tremor in patients with essential tremor who had not had a response to medication. Adverse effects of the procedure included sensory deficits and gait disturbances. Essential tremor, the most common movement disorder, 1 is characterized by a distinctive postural and intention tremor typically affecting the hands more than the legs, trunk, head, or voice. 2 , 3 Essential tremor does not shorten life expectancy, but it can affect quality of life, functional activities, mood, and socialization. 4 – 6 Class I evidence exists for propranolol and primidone as first-line medications that reduce tremor by approximately 60% in 50% of patients. 7 – 11 If resistance to medications develops or side effects are unacceptable, neurosurgical intervention is considered, primarily targeting the nucleus ventralis intermedius of the thalamus, a component of tremor circuitry that . . .
A multi-centre randomised trial comparing ultrasound vs mammography for screening breast cancer in high-risk Chinese women
Background: Chinese women tend to have small and dense breasts and ultrasound is a common method for breast cancer screening in China. However, its efficacy and cost comparing with mammography has not been evaluated in randomised trials. Methods: At 14 breast centres across China during 2008–2010, 13 339 high-risk women aged 30–65 years were randomised to be screened by mammography alone, ultrasound alone, or by both methods at enrolment and 1-year follow-up. Results: A total of 12 519 and 8692 women underwent the initial and second screenings, respectively. Among the 30 cancers (of which 15 were stage 0/I) detected, 5 (0.72/1000) were in the mammography group, 11 (1.51/1000) in the ultrasound group, and 14 (2.02/1000) in the combined group ( P =0.12). In the combined group, ultrasound detected all the 14 cancers, whereas mammography detected 8, making ultrasound more sensitive (100 vs 57.1%, P =0.04) with a better diagnostic accuracy (0.999 vs 0.766, P =0.01). There was no difference between mammography and ultrasound in specificity (100 vs 99.9%, P =0.51) and positive predictive value (72.7 vs 70.0%; P =0.87). To detect one cancer, the costs of ultrasound, mammography, and combined modality were $7876, $45 253, and $21 599, respectively. Conclusions: Ultrasound is superior to mammography for breast cancer screening in high-risk Chinese women.
Impact of Denture Cleaning Method and Overnight Storage Condition on Denture Biofilm Mass and Composition: A Cross-Over Randomized Clinical Trial
Appropriate oral hygiene is required to maintain oral health in denture wearers. This study aims to compare the role of denture cleaning methods in combination with overnight storage conditions on biofilm mass and composition on acrylic removable dentures. In a cross-over randomized controlled trial in 13 older people, 4 conditions with 2 different mechanical cleaning methods and 2 overnight storage conditions were considered: (i) brushing and immersion in water without a cleansing tablet, (ii) brushing and immersion in water with a cleansing tablet, (iii) ultrasonic cleaning and immersion in water without a cleansing tablet, and (iv) ultrasonic cleaning and immersion in water with a cleansing tablet. Each test condition was performed for 5 consecutive days, preceded by a 2-days wash-out period. Biofilm samples were taken at baseline (control) and at the end of each test period from a standardized region. Total and individual levels of selected oral bacteria (n = 20), and of Candida albicans were identified using the Polymerase Chain Reaction (PCR) technique. Denture biofilm coverage was scored using an analogue denture plaque score. Paired t-tests and Wilcoxon-signed rank tests were used to compare the test conditions. The level of significance was set at α< 5%. Overnight denture storage in water with a cleansing tablet significantly reduced the total bacterial count (p<0.01). The difference in total bacterial level between the two mechanical cleaning methods was not statistically significant. No significant effect was observed on the amount of Candida albicans nor on the analogue plaque scores. The use of cleansing tablets during overnight denture storage in addition to mechanical denture cleaning did not affect Candida albicans count, but reduced the total bacterial count on acrylic removable dentures compared to overnight storage in water. This effect was more pronounced when combined with ultrasonic cleaning compared to brushing. ClinicalTrials.gov NCT02454413.
A Pilot Study of Focused Ultrasound Thalamotomy for Essential Tremor
In an uncontrolled, open-label pilot study, essential tremor improved in 15 patients treated with MRI-guided focused ultrasound thalamotomy. Adverse effects included persistent paresthesias in four patients. The study was too small to assess the safety of this procedure. Essential tremor, the most common movement disorder, with a prevalence as high as 4%, is characterized by a rhythmic oscillation of agonist and antagonist muscle groups, typically between 8 and 12 Hz. 1 The cause of this disorder remains unknown, although there is often a familial component with a link to a particular polymorphism in the gene encoding leucine-rich repeat and immunoglobulin domain–containing protein 1 ( LINGO1 ). Although essential tremor is not medically dangerous, it is progressive and disabling in the home and workplace. 2 The degree of tremor does not always correlate with the severity of disability, 3 and patients with . . .
Application of non-contact ultrasonic method in air to study fiber-cement corrugated boards
The fiber-cement and cellulose boards are materials commonly used in architectural engineering for exterior and interior applications such as building facades or as wall and roof covering materials. The aim of the study was to present the ultrasonic non-contact method of testing fiber-cement boards with Lamb waves and to discuss the results and limitations of the method in context of quality control of the material. The experiments were performed for the corrugated boards using a laboratory non-contact ultrasonic scanner. Lamb waves were generated in the tested materials by a transmitter excited by a chirp signal with a linearly modulated frequency. Waves transmitted through the tested material are acquired by the receiver and registered by the PC based acquisition system. The tests were done on reference plate board and the corrugated boards. As the main descriptor to assess the quality of tested boards the maximum amplitude of transmitted Lamb waves was selected. The significant role of boundary effects and frequency of waves was noticed. The obtained results have confirmed the usefulness of the applied ultrasonic method for testing macroscopic inhomogeneity of corrugated fiber-cement boards.
Pb(II) Adsorption Properties of a Three-Dimensional Porous Bacterial Cellulose/Graphene Oxide Composite Hydrogel Subjected to Ultrasonic Treatment
A three-dimensional porous bacterial cellulose/graphene oxide (BC/GO) composite hydrogel (BC/GO) was synthesized with multi-layer graphene oxide (GO) as the modifier and bacterial cellulose as the skeleton via an ultrasonic shaking process to absorb lead ions effectively. The characteristics of BC/GO were investigated through TEM, SEM, FT-IR, NMR and Zeta potential experiments. Compared to bacterial cellulose, the ultrasonic method and the carboxyl groups stemming from GO helped to enhance the availability of O(3)H of BC, in addition to the looser three-dimensional structure and enriched oxygen-containing groups, leading to a significantly higher adsorption capacity for Pb(II). In this paper, the adsorption behavior of BC/GO is influenced by the GO concentration, adsorption time, and initial concentration. The highest adsorption capacity for Pb(II) on BC/GO found in this study was 224.5 mg/g. The findings implied that the pseudo-second-order model explained the BC/GO adsorption dynamics and that the data of its adsorption isotherm fit the Freundlich model. Because of the looser three-dimensional structure, the complexation of carboxyl groups, and the enhanced availability of O(3)H, bacterial cellulose exhibited a much better adsorption capacity.
Durability of Concrete with Superabsorbent Polymer (SAP) Assessed Using Depth of Carbonation and NDT Ultrasonic Methods
The paper concerns destructive and non-destructive (NDT) evaluation of the effect of the addition of superabsorbent polymer (SAP) used as a carrier of mixing water and a means of internal curing on the durability of concrete. The research concerns testing of five concretes—an ordinary reference concrete and four concretes differing in the content of mixing water introduced into the concrete mix in the form of pre-saturated SAP particles (25%, two variants of 50% and 75% of the total mixing water in the form of SAP hydrogel). The research consisted of 4 stages of tests. The subsequent stages involved the analysis of the effect of using SAP as a carrier of mixing water on the particular characteristics of concrete mix and hardened concrete, i.e., consistency and density of concrete mix (1st stage), carbonation tested using two indicators—phenolphthalein and thymol phenolphthalein (2nd stage), and finally: the homogeneity of the concretes’ structure by means of ultrasonic method (determination of ultrasonic pulse velocity) 28 days after production (3rd stage) and 3 years after production (4th stage). The ultrasonic pulse (or wave) velocity was then correlated with the content of water applied in the form of SAP hydrogel. The statistical analysis of results showed that the method of introducing the mixing water into the concrete mix in the form of pre-absorbed superabsorbent polymer, although it changed the concrete mix consistency, did not significantly affect the concrete ability to resist carbonation. Meanwhile, after 3 years, the densification of the microstructure of concrete with SAP has been observed.
Experimental Study of Mechanical Wave Propagation in Solidifying Cement-Based Composites
In this paper, a new measurement procedure is presented as an experimental study. In this experimental study, a measurement system using the pass-through pulsed ultrasonic method was used. The pilot application of the measurement setup was to monitor mechanical wave changes during the solidification and hardening of fine-grained cement-based composites. The fine-grained composites had different water–cement ratios. The measured results show apparent differences in the recorded mechanical wave parameters. Significant differences were observed in the waveforms of the amplitude increase in the passing mechanical waves. At the same time, the frequency spectra of the five most dominant frequencies are presented, where the frequency lines are clear, indicating the quality of the hydration process. Based on the results, it can be concluded that the new method is usable for fine-grained cement-based materials but is not limited to that. The advantages of this method are its high variability and non-destructive character. The experimental study also outlines the possible future applications of the pulsed passage ultrasonic method.
Low intensity pulsed ultrasound (LIPUS) for bone healing: a clinical practice guideline
Does low intensity pulsed ultrasound (LIPUS) accelerate recovery in adults and children who have experienced bone fractures or osteotomy (cutting of a bone)? An expert panel rapidly produced these recommendations based on a linked systematic review triggered by a large multicentre randomised trial in adults with tibial fracture.
Optimisation of the removal of antibiotics from aqueous environments through ultrasonic processing with α-hematite nanoparticles using response surface methodology (case study: cefixime)
The occurrence of contamination of emerging concerns (CECs) has turned into a significant challenge. In the present study, the elimination of Cefixime from the aquatic media was optimized. The ultrasonic method, combined through α-hematite nanoparticles, was studied using the response surface methodology (RSM). In this examination, various factors were evaluated to determine their impact, including pH levels (ranging from 5 to 11), nanoparticle dosage (0.05–0.3 g/L), contact time (10–90 min), primary Cefixime concentration (25–100 mg/L), and ultrasound wave frequencies (35–130 kHz). Nanoparticle characteristics were determined through Brunauer–Emmett–Teller (BET) and X-ray diffraction (XRD) analysis. The chemical oxygen demand (COD) was measured to monitor the removal of Cefixime. The outcomes of the data analysis revealed that the catalyst dosage and contact time were the most significant factors influencing the Cefixime removal rate. The optimal conditions determined during the experiments included a pH of 3, an ultrasound wave frequency of 37 kHz, an initial Cefixime concentration of 25 mg/L, a catalyst dosage of 0.25 g/L, and a reaction time of 90 min. Under these conditions, a COD elimination efficiency of 98.7% was attained for Cefixime. The process kinetics adhered to a pseudo-second-order (PSO) model, achieving an R 2 value of 0.9905. The findings of this research demonstrate the high efficiency of the sonocatalytic removal technique in eliminating Cefixime antibiotics from aqueous solutions.