Top-down and bottom-up neurodynamic evidence in patients with tinnitus

AbstractAlthough a peripheral auditory (bottom-up) deficit is an essential prerequisite for the generation of tinnitus, central cognitive (top-down) impairment has also been shown to be an inherent neuropathological mechanism. Using an auditory oddball paradigm (for top-down analyses) and a passive listening paradigm (for bottom-up analyses) while recording electroencephalograms (EEGs), we investigated whether top-down or bottom-up components were more critical in the neuropathology of tinnitus, independent of peripheral hearing loss. We observed significantly reduced P300 amplitudes (reflecting fundamental cognitive processes such as attention) and evoked theta power (reflecting top-down regulation in memory systems) for target stimuli at the tinnitus frequency of patients with tinnitus but without hearing loss. The contingent negative variation (reflecting top-down expectation of a subsequent event prior to stimulation) and N100 (reflecting auditory bottom-up selective attention) were different between the healthy and patient groups. Interestingly, when tinnitus patients were divided into two subgroups based on their P300 amplitudes, their P170 and N200 components, and annoyance and distress indices to their tinnitus sound were different. EEG theta-band power and its Granger causal neurodynamic results consistently support a double dissociation of these two groups in both top-down and bottom-up tasks. Directed cortical connectivity corroborates that the tinnitus network involves the anterior cingulate and the parahippocampal areas, where higher-order top-down control is generated. Together, our observations provide neurophysiological and neurodynamic evidence revealing a differential engagement of top-down impairment along with deficits in bottom-up processing in patients with tinnitus but without hearing loss

Increasing the Durability of Piezoelectric Impact-based Micro Wind Generator in Real Application

AbstractThe purpose of this study is to increase the durability of piezoelectric impact-based micro wind generator (PIMWG) in real application. Using new PIMWG design, numerical simulation, and experimental comparison analysis, we improved the durability of PIMWGs in real application. The experimental results show that the optimized PIMWG generated 2.4 mW (RMS value), and it did not crack within 40h. In this study, we improved the durability of PIMWGs for real application

Impact of Cigarette Smoking and Exercise on Arterial Stiffness: A Narrative Literature Review

PURPOSE Smoking often causes acute and chronic cardiovascular disorders. Cigarette smoking increases oxidative stress, reduces nitric oxide bioavailability, and changes the extracellular matrix, impairing arterial stiffness. However, regular physical activity and smoking cessation significantly and rapidly reverse the detrimental effects. This narrative review summarizes the relevant research that describes the impacts of cigarette smoking on the cardiovascular system and demonstrates the therapeutic or preventative roles of exercise and smoking cessation in smoking-associated arterial stiffness. METHODS We used scientific search engines, including PubMed, Web of Science, Google Scholar, and Wiley Online Library, to identify previous studies exploring the effects of smoking, exercise, and smoking cessation on arterial stiffness. RESULTS We discussed the most important therapeutic and/or preventive roles of exercise and smoking cessation in decreasing arterial stiffness. Most studies have demonstrated that acute and chronic smoking increase arterial stiffness. Smoking and physical activity were negatively associated. However, this relationship was often attenuated or reversed during adult exercise interventions. In addition, smoking cessation reversed the effects of smoking on arterial stiffness. CONCLUSIONS Smoking increases the risk of acute and chronic cardiovascular disease. Cigarette smoking deteriorates arterial stiffness by altering the vascular walls. However, regular exercise and smoking cessation can improve or prevent impaired arterial stiffness

Feasibility of video-based real-time nystagmus tracking: a lightweight deep learning model approach using ocular object segmentation

BackgroundEye movement tests remain significantly underutilized in emergency departments and primary healthcare units, despite their superior diagnostic sensitivity compared to neuroimaging modalities for the differential diagnosis of acute vertigo. This underutilization may be attributed to a potential lack of awareness regarding these tests and the absence of appropriate tools for detecting nystagmus. This study aimed to develop a nystagmus measurement algorithm using a lightweight deep-learning model that recognizes the ocular regions.MethodThe deep learning model was used to segment the eye regions, detect blinking, and determine the pupil center. The model was trained using images extracted from video clips of a clinical battery of eye movement tests and synthesized images reproducing real eye movement scenarios using virtual reality. Each eye image was annotated with segmentation masks of the sclera, iris, and pupil, with gaze vectors of the pupil center for eye tracking. We conducted a comprehensive evaluation of model performance and its execution speeds in comparison to various alternative models using metrics that are suitable for the tasks.ResultsThe mean Intersection over Union values of the segmentation model ranged from 0.90 to 0.97 for different classes (sclera, iris, and pupil) across types of images (synthetic vs. real-world images). Additionally, the mean absolute error for eye tracking was 0.595 for real-world data and the F1 score for blink detection was ≥ 0.95, which indicates our model is performing at a very high level of accuracy. Execution speed was also the most rapid for ocular object segmentation under the same hardware condition as compared to alternative models. The prediction for horizontal and vertical nystagmus in real eye movement video revealed high accuracy with a strong correlation between the observed and predicted values (r = 0.9949 for horizontal and r = 0.9950 for vertical; both p < 0.05).ConclusionThe potential of our model, which can automatically segment ocular regions and track nystagmus in real time from eye movement videos, holds significant promise for emergency settings or remote intervention within the field of neurotology

CT Evidence for Subchondral Trabecular Injury of the Femoral Head in Transient Osteoporosis of the Hip: A Case Report

A 28-yr-old woman presented with both hip pain that started sequentially during the peripartum period. Diagnosis of transient osteoporosis of the hip (TOH) was made based on typical findings of plain radiographs and magnetic resonance images. The subchondral trabeculae of the femoral head were evaluated on serially taken coronal multiplanar reformation computerized tomogram images. At 4 weeks after pain onset, marked decrease in the sclerotic density with irregular discontinuation was observed in the primary compression trabeculae. At 12 weeks, a focal area of irregular thickening of trabeculae was observed. At 20 weeks, sclerotic density of trabeculae recovered markedly and the focal area of irregular trabecular thickening disappeared. At 1 yr, subchondral trabeculae recovered almost completely. The evidence of subchondral trabecular injury was observed in the femoral heads of TOH

Fenolni sastav i antioksidativna svojstva esencijalnog ulja dobivenog iz piljevine pačempresa mikrovalnom ekstrakcijom i hidrodestilacijom

Reactive oxygen species and free radicals play a major role in food deterioration. Current research is directed towards finding naturally occurring antioxidants of plant origin. In the present study, the chemical composition analysis of the essential oil obtained from sawdust of Chamaecyparis obtusa (COEO) was conducted by gas chromatography coupled with mass spectroscopy (GC-MS). Further, the phenolic content and antioxidant capacity of the COEO were investigated using different radical scavenging assays. The COEO obtained from the dried sawdust material using a microwave-assisted hydrodistillation technique resulted in the determination of 46 different compounds by GC-MS analysis, representing 98.94 % of total oil content. The COEO was characterised by the presence of mono- and sesquiterpene hydrocarbons, oxygenated mono- and sesquiterpenes, steroids, diterpenes and indole derivatives. At the highest tested concentration range, the COEO showed antioxidant capacity, i.e. the inhibition of DPPH, nitric oxide, superoxide and hydroxyl radicals of 80.16, 82.93, 72.99 and 71.62 %, respectively. Moreover, the COEO displayed concentration-dependent reducing power ability and remarkable inhibitory effect on ferric ion-induced lipid peroxidation in bovine brain extract. In addition, the COEO yielded (6.13±0.05) mg of gallic acid per g of dry mass. The present study confirms that the C. obtusa essential oil has potent antioxidant, lipid peroxidation inhibition and radical scavenging abilities; therefore, it might be used as a natural antioxidant to prevent food deterioration.Reaktivni spojevi kisika i slobodni radikali glavni su uzrok propadanja hrane, pa su najnovija istraživanja usmjerena na pronalazak prirodnih antioksidanasa biljnoga podrijetla. U ovom je radu plinskom kromatografijom i masenom spektrometrijom analiziran kemijski sastav esencijalnog ulja dobivenog iz piljevine pačempresa (Chamaecyparis obtusa). Udjel fenolnih spojeva i antioksidativna svojstva dobivenog ulja ispitani su pomoću različitih mehanizama uklanjanja slobodnih radikala. U esencijalnom je ulju pačempresa dobivenom mikrovalnom ekstrakcijom i hidrodestilacijom sušene piljevine pomoću plinske kromatografije i masene spektrometrije određeno 46 spojeva koji čine 98,94 % ukupnog sastava ulja. Ulje sadržava mono- i seskviterpene, oksigenizirane mono- i seskviterpene, steroide, diterpene i derivate indola. Pri najvećoj je koncentraciji esencijalno ulje pačempresa inhibiralo 80,16 % DPPH radikala, 82,93 % dušikovog monoksida, 72,99 % superoksida i 71,62 % hidroksilnih radikala. Osim toga, utvrđeno je da je reducirajuća snaga ulja ovisila o njegovoj koncentraciji, te da je ulje znatno inhibiralo peroksidaciju lipida kataliziranu ionima željeza(II) u goveđem ekstraktu. Ulje je sadržavalo (6,13±0,05) mg galne kiseline po gramu suhe tvari. Ovo istraživanje potvrđuje da esencijalno ulje pačempresa ima jaka antioksidativna svojstva, te dobru sposobnost inhibicije peroksidacije lipida i uklanjanja slobodnih radikala, pa se može upotrijebiti kao prirodni antioksidans u svrhu očuvanja svježine hrane