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Hardin Nunez posted an update 1 week, 5 days ago
The insertion of the electrode array is a critical step in cochlear implantation. Herein we comprehensively investigate the impact of the alignment angle and feed-forward speed on deep insertions in artificial scala tympani models with accurate macro-anatomy and controlled frictional properties.
Motorized insertions (n=1033) were performed in six scala tympani models with varying speeds and alignment angles. We evaluated reaction forces and micrographs of the insertion process and developed a mathematical model to estimate the normal force distribution along the electrode arrays.
Insertions parallel to the cochlear base significantly reduce insertion energies and lead to smoother array movement. Tazemetostat molecular weight Non-constant insertion speeds allow to reduce insertion forces for a fixed total insertion time compared to a constant feed rate.
In cochlear implantation, smoothness and peak forces can be reduced with alignment angles parallel to the scala tympani centerline and with non-constant feed-forward speed profiles.
Our results may help to provide clinical guidelines and improve surgical tools for manual and automated cochlear implantation.
Our results may help to provide clinical guidelines and improve surgical tools for manual and automated cochlear implantation.
Noise and low quality of ECG signals acquired from Holter or wearable devices deteriorate the accuracy and robustness of R-peak detection algorithms. This paper presents a generic and robust system for R-peak detection in Holter ECG signals. While many proposed algorithms have successfully addressed the problem of ECG R-peak detection, there is still a notable gap in the performance of these detectors on such low-quality ECG records.
In this study, a novel implementation of the 1D Convolutional Neural Network (CNN) is used integrated with a verification model to reduce the number of false alarms. This CNN architecture consists of an encoder block and a corresponding decoder block followed by a sample-wise classification layer to construct the 1D segmentation map of R-peaks from the input ECG signal. Once the proposed model has been trained, it can solely be used to detect R-peaks possibly in a single channel ECG data stream quickly and accurately, or alternatively, such a solution can be conveniently emplighly generic system and therefore applicable to any ECG dataset.Oligodendrocytes are highly specialized glial cells, responsible for producing myelin in the central nervous system (CNS). The multi-stage process of oligodendrocyte development is tightly regulated to ensure proper lineage progression of oligodendrocyte progenitor cells (OPCs) to mature myelin producing oligodendrocytes. This developmental process involves complex interactions between several intrinsic signaling pathways that are modulated by an array of extrinsic factors. Understanding these regulatory processes is of crucial importance, as it may help to identify specific molecular targets both to enhance plasticity in the normal CNS and to promote endogenous recovery following injury or disease. This review describes two major regulators that play important functional roles in distinct phases of oligodendrocyte development OPC proliferation and differentiation. Specifically, we highlight the roles of the extracellular astrocyte/radial glia-derived protein Endothelin-1 in OPC proliferation and the intracellular Akt/mTOR pathway in OPC differentiation. Lastly, we reflect on how recent advances in neuroscience and scientific technology will enable greater understanding into how intrinsic and extrinsic regulators interact to generate oligodendrocyte diversity.This article discusses some examples of problems derived from the mix of technical jargon and anatomical veterinary words and makes recommendations regarding their use according to specific situations.The chaperone-assisted soluble expression and characterization of high molecular weight chitinase chiZJ408 in Escherichia coli BL21 were investigated. Chitin degradation products by chitinase chiZJ408 were analyzed. The results indicated that the introduction of the chaperone GroELS promoted the correct folding of chitinase chiZJ408 and increased its soluble expression by 14.9% (p less then 0.05) in E. coli BL21. The optimal pH and temperature of chitinase chiZJ408 were respectively 6.0 and 50 °C. Chitinase chiZJ408 was stable at pHs of 4.0 ∼ 7.0 and at below 40 °C. Mg2+and Ca2+ had a significant impact on improving the activity of chitinase chiZJ408. Chitinase chiZJ408 was demonstrated to be exochitinase that cleaved the β-1,4-glycosidic bond of the chitin chain to generate only N,N’-diacetylchitobiose. This study broadens our understanding of chitinase and provides a basis for solving the problem of inclusion body formed by long fragment gene expression in E. coli.Rhubarb, a famous traditional Chinese medicine, shows a wide range of physiological activities and pharmacological benefits. Rhubarb anthraquinones are perceived as the pharmacologically active compounds of Rhubarb, and understanding metabolism of them is crucial to assure safety and effectiveness of clinical application. In this study, the pharmacokinetics, tissue distribution and excretion of five rhubarb anthraquinones (aloe-emodin, rhein, emodin, chrysophanol, physcion) were systematically investigated after oral administration of rhubarb extract to rats.An HPLC method was developed and validated for quantitation of five rhubarb anthraquinones in rat plasma, tissues, urine and faeces to investigate the Pharmacokinetic characteristics. The results showed that the proposed method was suitable for the quantification of five anthraquinones in plasma, tissue and excreta samples with satisfactory linear (r > 0.99), precision ( less then 10%) and recovery (85.12-104.20%). The plasma concentration profiles showed a quick absorption with the mean Tmax of 0.42-0.75 h and t1/2 of 6.60-15.11 h for five anthraquinones. The analytes were widely distributed in most of the tissues. Approximately 0.13-10.59% and 28.47-81.14% of five anthraquinones were recovered in urine and faeces within 132 h post-dosing, which indicated the major elimination route was faeces excretion.In summary, this study lays a foundation for elucidating the pharmacokinetic rule of rhubarb anthraquinone and the important data can provide reliable scientific resource for further research.