Low-cost optoacoustics? Prospects for miniaturizing and democratizing optoacoustic imaging systems in biomedical research and the clinics

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The Effect of Political Crisis between Countries on International Trade and International Logistics: A Qualitative Study on Turkey-Russia Relations

International trade and international logistics operations, which rose due to changes in international trade are exactly affected by fluctuations in cross-country political, economic and socio-cultural relations. Leading effects of conflicts which countries sometimes experience especially in the political arena manifests itself primarily by affecting foreign trade firms working with concerned countries and international logistics firms negatively. The study aims to identify the consequences that could reveal for international trade and logistics sector of politically strained Turkey-Russia relations recently by focusing mainly on road transportation. In order to accomplish its purpose, the study describes results of political tensions between two countries by making in-depth interviews with representatives of international trade and logistics firms working with Russia in Turkey in the light of opinion of sector representatives. The purpose of this study is to evaluate the answers acquired from in depth interviews with the foreign trade and international logistics companies that makes business with Russia by using content analysis and to clarify the effects of the political tension.Keywords: Political Relations, Political Crisis, International Trade, International Logistics.JEL Class.: F14, O11, P16.Abstract. International trade and international logistics operations, which rose due to changes in international trade are exactly affected by fluctuations in cross-country political, economic and socio-cultural relations. Leading effects of conflicts which countries sometimes experience especially in the political arena manifests itself primarily by affecting foreign trade firms working with concerned countries and international logistics firms negatively. The study aims to identify the consequences that could reveal for international trade and logistics sector of politically strained Turkey-Russia relations recently by focusing mainly on road transportation. In order to accomplish its purpose, the study describes results of political tensions between two countries by making in-depth interviews with representatives of international trade and logistics firms working with Russia in Turkey in the light of opinion of sector representatives.The purpose of this study is to evaluate the answers acquired from in depth interviews with the foreign trade and international logistics companies that makes business with Russia by using content analysis and to clarify the effects of the political tension.Keywords: Political relations, Political crisis, International trade, International logistics.JEL. F14, O11, P16

Dentoalveolar Effects of Miniscrew Implant Supported Distalization System

Aim:The aim of this prospective clinical study is to evaluate the treatment effects of the miniscrew implant supported distalization system in patients with Class II malocclusion.Subjects and Methods:The study sample consisted of 10 patients (5 girls and 5 boys) with a mean age of 14,9 years. Two titanium intermaxillary fixation screws were placed lateral to the foramen incisivum in the anterior paramedian region of the palate. Alginate impressions were taken and appliances were constructed on the model casts. The MISDS was cemented on the upper first molars, then connected to the miniscrews by means of metallic ligatures. The appliance was activated by squeezing the open coil springs. 200 g of distalization force was applied on each side. Lateral cephalometric radiographs were obtained before (T0) and after (T1) the distalization were measured. Data was analysed by SPSS.Results:The mean maxillary first molar distalization was 2,45 mm (p<0.05) and 1° (p<0.05) slight distal tipping accompanied distalization. Maxillary second molars distalized 4.35 mm (p<0.05) and tipped 2°(p<0.05) distally. The upper second premolars showed 3 mm distal drift following the upper first molars and tipped 2.3° distally, while 2.35 mm spontaneous distalization and 1.6° distal tipping were seen on the upper first premolars. Upper incisors were retroclined 1.45° (p<0.05), which decreased the overjet 0.8 mm.Conclusion:MISDS is an efficient way of noncompliance maxillary molar distalization which results with almost translatory distal upper molar movement

Volumetric optoacoustic neurobehavioral tracking of epileptic seizures in freely-swimming zebrafish larvae

Fast three-dimensional imaging of freely-swimming zebrafish is essential to understand the link between neuronal activity and behavioral changes during epileptic seizures. Studying the complex spatiotemporal patterns of neuronal activity at the whole-brain or -body level typically requires physical restraint, thus hindering the observation of unperturbed behavior. Here we report on real-time volumetric optoacoustic imaging of aberrant circular swimming activity and calcium transients in freely behaving zebrafish larvae, continuously covering their motion across an entire three-dimensional region. The high spatiotemporal resolution of the technique enables capturing ictal-like epileptic seizure events and quantifying their propagation speed, independently validated with simultaneous widefield fluorescence recordings. The work sets the stage for discerning functional interconnections between zebrafish behavior and neuronal activity for studying fundamental mechanisms of epilepsy and in vivo validation of treatment strategies

Development of Optoacoustic Methods for Ultrafast Cardiac Imaging and Treatment Monitoring

Optoacoustic (OA) imaging technology has become a widely used tool in various preclinical and clinical applications, owing to its non-invasive, real-time, and volumetric imaging capabilities. OA imaging combines the advantages of rich optical contrast and high spatial resolution in deep tissues not affected by photon scattering. The inherent multi-scale nature of the OA method has enabled a better understanding of physiological and pathophysiological processes of high relevance in various biomedical fields such as oncology, neuroscience, and cardiology. For the latter, OA tomography (OAT) has successfully demonstrated visualization of cardiovascular dynamics and extraction of functional information by using light in the near-infrared wavelength range. Despite important technical advances, OAT is yet to achieve sufficient temporal resolution performance for visualizing ultrafast biological phenomena such as electromechanical wave propagation in the heart. This thesis has aimed at developing new OAT-based imaging methods for visualizing rapid cardiovascular dynamics and treatment monitoring. Ultrafast imaging capabilities have been accomplished by utilizing compressed-sensing data acquisition schemes, subsequently allowing for cardiac mechanical wave propagation to be recorded in a murine cardiac arrhythmia model. A compact, highspeed, volumetric OAT imager based on a software-defined ultrasound (US) system was also developed to produce high quality images at high frame rates, whose performance was validated by volumetric angiography in humans. Finally, methods for real-time monitoring of cardiac ablation treatments with OAT have been introduced

Ultrafast imaging of cardiac electromechanical wave propagation with volumetric optoacoustic tomography

Understanding the mechanisms of cardiac disorders largely depends on availability of multi-dimensional and multiparametric imaging methods capable of quantitative assessment of cardiac morphology and function. The imaging modalities commonly employed in cardiac research, such as ultrasonography and magnetic resonance imaging, are lacking sufficient contrast and/or spatio-temporal resolution in 3D in order to reveal the multi-scale nature of rapid electromechanical activity in a beating heart. Our recently developed volumetric optoacoustic tomography (VOT) platform offers versatile observations of the heart function with rich optical contrast at otherwise unattainable temporal and spatial resolutions. Herein, we further advance the imaging performance by developing compressed acquisition scheme to boost the temporal resolution of VOT into the kilohertz range, thus enabling 3D mapping of electromechanical wave propagation in the heart. Experiments in isolated mouse hearts were performed by exciting the entire imaged tissue volume with nanosecond-duration laser pulses at 1 kHz repetition rate pulse operating at 532 nm and sparse tomographic signal sampling using a custom-made 512-element spherical matrix ultrasound array. By analyzing the strain maps obtained from the rapid VOT image sequence, it was possible to quantify the phase velocity of the electromechanical cardiac waves, in good agreement with previously reported values

Formulation development and evaluation of taste-masked atomoxetine hydrochloride orally disintegrating tablets (Odts)

© 2021 Marmara University Press ISSN: 2630-6344.Atomoxetine hydrochloride is a selective norepinephrine reuptake inhibitor used for the treatment of attention deficit/hyperactivity disorder. Atomoxetine hydrochloride is available in the form of capsules and oral solutions, yet it has no orally disintegrating form due to its bitter taste. ODTs are formulated to disintegrate rapidly upon contact with saliva and enable oral administration without water or chewing and offer improved patient compliance and ease of administration. Appropriate taste masking has great importance for ODTs. In this study, developing a taste-masked ODT formulation containing atomoxetine hydrochloride produced using the wet granulation method was aimed. Formulations were designed by changing the granulation agent (Hydroxypropylmethylcellulose (HPMC), Gellan gum, Veegum, Polyethylene glycol (PEG) 20000P) and active substance to granulation agent ratio (1:2, 1:3, 1:4). Each formulation was tested physically and chemically. According to the results, it was concluded that Gellan gum is more appropriate for use in ODTs for taste masking

In vivo optoacoustic monitoring of percutaneous laser ablation of tumors in a murine breast cancer model

Laser ablation (LA) is a promising approach for minimally invasive cancer treatments. Its in vivo applicability is often impeded by the lack of efficient monitoring tools that can help to minimize collateral tissue damage and aid in determining the optimal treatment end-points. We have devised a new, to the best of our knowledge, hybrid LA approach combining simultaneous volumetric optoacoustic (OA) imaging to monitor the lesion progression accurately in real time and 3D. Time-lapse imaging of laser ablation of solid tumors was performed in a murine breast cancer model in vivo by irradiation of subcutaneous tumors with a 100 mJ short-pulsed (∼5ns) laser operating at 1064 nm and 100 Hz pulse repetition frequency. Local changes in the OA signal intensity ascribed to structural alterations in the tumor vasculature were clearly observed, while the OA volumetric projections recorded in vivo appeared to correlate with cross sections of the excised tumors