Residual Contraction Research Articles

EEG Signal Denoising Based on Deep Residual Shrinkage Network

In recent years, EEG signals are usually denoised by traditional algorithms, which suffer from large amounts of computation, a limited number of channels, or modal aliasing. To achieve better denoising, a deep residual contraction network is proposed to denoise EEG signals. At the same time, on the basis of the original residual shrinkage building units, a new soft threshold module is used to replace the ReLU function to construct a new network model. Through different groups of denoising experiments, the effectiveness of this denoising algorithm is verified.

Health Status Recognition of Rotating Machinery Based on Deep Residual Shrinkage Network Under Time-Varying Conditions

Currently, the research on the health state of rotating machinery under time-varying operating conditions mainly focuses on using a combination of several constant operating conditions or uniformly changing speed and load. This article studied the health status recognition of rotating machinery under nonlinear and continuous changes in speed and load. A health status recognition method of rotating machinery was proposed based on the gram angle field and deep residual contraction network. Considering the influence of working conditions on signal characteristics, the speed, load, and multidimensional time-domain features are fused to form feature vectors. The feature vectors were transformed into images by gram coding. The color contrast relationship mapped from the overall difference distribution of sample feature indexes to the image was not changed while the feature timing was retained, which weakened the influence of working condition information on the sample state, improved the deep residual shrinkage network (DRSN) structure, and introduced the Gaussian error linear unit (GELU) activation function. The experimental verification is completed on the reducer experimental platform and the Xi’an Jiaotong University (XJTU)-Changxing Sumyoung Technology Company Ltd. (XJTU-SY) dataset. The results show that the method can effectively identify the health state of rotating machinery under time-varying working conditions.

Electromyography pattern-recognition based prosthetic limb control using various machine learning techniques

People who have lost their limbs to amputation and neurological disorders confront this loss every morning. As per the literature review, nearly 30% of the Indian population suffered from upper extremity amputation. As a coping-up measure, a force-controlled prosthetic limb has been developed to improve their self-reliance, quality of lifestyle and mental strength. The current prosthetic limb operation is done by residual muscle contraction, which contributes to the activation of the sensor and the motor. But there are some cons, the amputee does not know how much pressure needs to be exerted for holding various objects. Also, the amputee still has to undergo the surgical procedure. However, this paper proposes a way to predict the force which is needed to regulate the voltage for the servomotors using different Machine Learning (ML) regression approaches. Support Vector Regressor (SVR), Linear Regression and Random Forest models have been used to predict that force requirement. After comparing the results, the Random Forest model gave a highly accurate prediction of the force needed to control the voltage for the DC servomotors

Analysis of clinical feature and genetic basis of a rare case with Olmsted syndrome

To analyze the clinical and genetic characteristics of a patient featuring autosomal dominant Olmsted syndrome. Clinical features of the patient was reviewed. High-throughput sequencing was carried out to detect potential genetic variants. The proband, a 12-year-old girl, featured excessive keratinization on hands and feet, contracture of finger joints, and abnormal position and residual contraction of the fifth toes. Skin biopsy showed significant hyperkeratosis, epidermal hyperplasia, and mild interepidermal cell edema. A de novo heterozygous missense variant c.2016G>T(p.Met672Ile) was identified in the TRPV3 gene by high-throughout sequencing. The result was verified by Sanger sequencing. The destructive palmoplantar keratosis in the child may be attributed to the c.2016G>T(p.Met672Ile) variant of the TRPV3 gene. Aboving finding has provided new evidence for the correlation of genetic variants with clinical phenotypes of Olmsted syndrome.

Bulk Fill flow resin contraction using 3D finite element model and calibration by Fiber Bragg Grating measurement

Contraction due to polymerization of dental resin can cause failure on the adhesive interfaces, can lead to problems such as the appearance of gaps in the interfaces, postoperative sensitivity, pulp damage and the return of the caries. The objective of this work is the study of stresses on the dental adhesive that are generated by the process shrinkage of resin associated with biting forces. A laboratory experiment measured the strains and temperature inside the FiltekTM Bulk Fill Flow resin during the process of polymerization using Fiber Bragg Grating sensors in an ex vivo tooth. From tomographic images a three-dimensional geometric model of the tooth was reconstructed. A pre-tension was calibrated to simulate the residual contraction on the resin 3 D model. Finally, an Finite Element Method analysis was performed to access the adhesive stresses at the interface enamel/dentin with the adhesive, considering as loading the residual polymerization contraction of the dental resin and also biting loads. The model was able to represented the strain obtained in the laboratory experiment. The results of the stress analysis shows that the outer regions of adhesive are more prone to failure, as veried by dental surgeons in clinical practice.

Left-Ventricular Pressure Relaxation and Diastolic Function of Isolated Working Mammalian Hearts at Hypothermia

Background: Hypothermia is well known to elevate the time constant (whatever model is used) of the isochoric left-ventricular pressure fall. Due to different critera in use, it remained unclear whether prolonged diastole in hypothermia is sufficient for complete relaxation. Detecting and quantifying incomplete relaxation may become a valuable tool to prevent diastolic heart failure in hypothermia.Methods: Left-ventricular pressure decays in isolated guinea pig and rat hearts are analysed by 4-parametric regression at different temperatures, at sinus rhythm and electrical stimulation. Residual contraction (F_RC) is introduced and quantified by extrapolating the model's pressure forecast to end-systole, subtracting the asymptote, and normalising.Resultts: Isochoric pressure decay fits the regression model at all temperatures and heart beat frequencies. Residual contraction is virtually absent at normothermia and remains very small (F_RC<3%) down to 31°C. Lower temperatures or pacing induces higher F_RC. Eventually, the pressure curve becomes considerably elevated and looses its concavity.Conclusions: Despite slower pressure fall, ventricular relaxation remains fairly complete at hypothermia; and depends on considerable autoregulation of the individual heart. It is concluded (not proved) that individual emergence of negative lusitropy may indicate imminent heart failure. Asymptotic pressure rises are interpreted at higher ventricular tonus, independent from velocity of relaxation. Gradual increasing time constants may be attributed to a general slowing of bioreactions as temperature falls. Remarkable curve shape changes may be caused by aftercontractions due to elevated Ca++ sensitivity at hypothermia and high Ca++ load by pacing.

Residual Contraction

Residual Contraction

Towards Ultra Low-Cost Myoactivated Prostheses.

In developing countries, due to the high cost involved, amputees have limited access to prosthetic limbs. This constitutes a barrier for this people to live a normal life. To break this barrier, we are developing ultra-low-cost closed-loop myoactivated prostheses that are easy to maintain manufacture and that do not require electrodes in contact with the skin to work effectively. In this paper, we present the implementation for a simple but functional hand prosthesis. Our simple design consists of a low-cost embedded microcontroller (Arduino), a wearable stretch sensor (adapted from electroresistive bands normally used for “insulation of gaskets” against EM fields), to detect residual muscle contraction as direct muscle volumetric shifts and a handful of common, not critical electronic components. The physical prosthesis is a 3D printed claw-style two-fingered hand (PLA plastic) directly geared to an inexpensive servomotor. To make our design easier to maintain, the gears and mechanical parts can be crafted from recovered materials. To implement a closed loop, the amount of closure of prosthesis is fed back to the user via a second stretch sensor directly connected to claw under the form of haptic feedback. Our concept design comprised of all the parts has an overall cost below AUD 30 and can be easily scaled up to more complicated devices suitable for other uses, i.e., multiple individual fingers and wrist rotation.

Voltage-Sensitive Fluorescence of Indocyanine Green in the Heart

So far, the optical mapping of cardiac electrical signals using voltage-sensitive fluorescent dyes has only been performed in experimental studies because these dyes are not yet approved for clinical use. It was recently reported that the well-known and widely used fluorescent dye indocyanine green (ICG), which has FDA approval, exhibits voltage sensitivity in various tissues, thus raising hopes that electrical activity could be optically mapped in the clinic. The aim of this study was to explore the possibility of using ICG to monitor cardiac electrical activity. Optical mapping experiments were performed on Langendorff rabbit hearts stained with ICG and perfused with electromechanical uncouplers. The residual contraction force and electrical action potentials were recorded simultaneously. Our research confirms that ICG is a voltage-sensitive dye with a dual-component (fast and slow) response to membrane potential changes. The fast component of the optical signal (OS) can have opposite polarities in different parts of the fluorescence spectrum. In contrast, the polarity of the slow component remains the same throughout the entire spectrum. Separating the OS into these components revealed two different voltage-sensitivity mechanisms for ICG. The fast component of the OS appears to be electrochromic in nature, whereas the slow component may arise from the redistribution of the dye molecules within or around the membrane. Both components quite accurately track the time of electrical signal propagation, but only the fast component is suitable for estimating the shape and duration of action potentials. Because ICG has voltage-sensitive properties in the entire heart, we suggest that it can be used to monitor cardiac electrical behavior in the clinic.

Effects of Aripiprazol On Cholinergic Neurotransmission in Gastric Smooth Muscles

Introduction Aripiprazole is an antipsychotic drug used for treatment of schizophrenia and bipolar disorders. Common side effects are on gastrointestinal system and their mechanism is not fully understood. Objectives Ex vivo study the effect of aripiprazol on circular strips of stomach smooth muscle. Aim To study the effects of aripiprazol on the smooth muscles in order to understand the causes for the common side effects on the gastrointestinal tract. Methods Gastric corpus smooth muscle preparations from male Wistar rats (n=12) were used. Strips were dissected and mounted and super fused with warmed Krebs solution. The contractile activity of smooth muscle preparations was registered isometrically. The activity was periodically tested by stimulation with 1×10 -6 mol/lacetylcholine. All statistical analyses were performed using a specialized software SPSS, version 16. Results Aripiprazol (1×10 - 6 mol/l – 1×10 -4 mol/l) caused contractions in gastric circular smooth muscle tissues from rats. M-cholinergic receptor-blocking agent atropine (1×10 -6 mol/l) significantly reduced the aripiprazol-induced contraction. In the presence of 1×10 -6 mol/l acetylcholine, aripiprazol (1×10 - 6 mol/l – 1×10 -4 mol/l) caused relaxation of the test muscle tissues. It was determined that the amplitude of the induced relaxation was concentration-dependent. Conclusions Our results permit the suggestion, that the effect of a ripiprazol involves cholinergic neurotransmission on gastric smooth muscles. This is confirmed by aripiprazol–induced contraction in atropine–treated tissues. Residual muscle contraction suggests the possible drug influence on other receptors. The fact is confirmed by the relaxation effect of aripiprazol in the presence of Acetylcholine, i.e. other effects of aripiprazol become more prominent.

Water Aging Reverses Residual Stresses in Hydrophilic Dental Composites

Dental composites develop residual stresses during polymerization due to shrinkage. These stresses may change with time because of relaxation and water sorption in the oral environment. This phenomenon is likely dependent on the composition of the materials, specifically their hydrophilic characteristics, and could result in deleterious stresses on restorative materials and tooth structure. The purpose of this experiment was to use the thin ring-slitting method to compare the residual stress generated within composite materials of varying hydrophilicity when aged in wet and dry conditions after polymerization. Water sorption, solubility, elastic modulus, and residual stresses were measured in 6 commercial composites/cements aged in water and dry conditions. The self-adhesive resin cement showed the highest water sorption and solubility. All composites showed initial residual contraction stresses, which were maintained when aged dry. Residual stresses in 2 of the self-adhesive cements and the polyacid-modified composite aged in wet conditions resulted in a net expansion. This experiment verified that residual shrinkage stresses in dental composites can be reversed during aging in water, resulting in a net expansion, with the effect directly related to their hydrophilic properties.

Reply to Letter to the Editor: New Tendon Transfer for Correction of Drop-foot in Common Peroneal Nerve Palsy

Titolo and colleagues proposed a modified version of Vigasio tendon transfer [7, 8] in which surgeons reroute only half of the anterior tibialis tendon. The remaining half of the anterior tibialis tendon is used as a rein to “improve in dorsiflexion the correct balance of pronation/supination of the foot especially when the exit hole of the transosseous tunnel at the third cuneiform is not perfectly centered on the axis of the ankle,” according to Titolo and colleagues’ letter to the editor. The basis for their proposal is not new. Numerous papers [2–6, 9] play on the “reins” concept in order to obtain a balanced foot dorsiflexion. Several bone attachments have also been tested (first, second, third cuneiform, cuboid, and the base of the fifth metacarpal bone). Goh and colleagues [1] demonstrated that the ideal tendon insertion to achieve a balanced foot dorsiflexion is on the third cuneiform. Generally, a “reins” procedure, like the one proposed by Titolo, has not been widely adopted among surgeons because the approach is technically demanding. Additionally, the procedure does not respect the “straight line of pull principle” on tendon transfer [1]. According to this principle, if two or more tendons are sutured with an oblique angle of incidence, the donor tendon further dissipates the residual contraction power, risking the creation of a tenodesis effect rather than a voluntary, dynamic dorsiflexion of the ankle and digits. The anterior tibialis tendon rerouting technique as described by Vigasio [7, 8] use an anterior tibialis tendon as a single rein. When correctly extracted from the third cuneiform, the tendon gives a working balanced foot dorsiflextion. We understand that surgical techniques continually need updates and revisions, and we thank Titolo and coauthors for their proposal.

Residual Muscle Contraction and Residuum Socket Interface Force in Men with Transtibial Osteomyoplastic Amputation

Residual Muscle Contraction and Residuum Socket Interface Force in Men with Transtibial Osteomyoplastic Amputation

Experimental investigation of the free swelling of crushed argillite

Callovo–Oxfordian argillite is studied in France as a possible host rock for repository of high-level radioactive wastes. A new experimental procedure is proposed to quantify the free swelling of its main constitutive clay phase, which is a key parameter to model the hydromechanical behaviour of this rock. The material was pulverised finely enough to remove any local stress that may prevent the free swelling induced by a change in water content. Powders were observed using an environmental scanning electron microscope and images recorded at various degrees of relative humidity were analysed by digital image correlation techniques to measure swelling strains. The investigation showed that the free swelling is moderate in comparison to other expansive clays (e.g. bentonite MX80). The magnitude of deformation becomes significant at high relative humidity. This swelling is not reversible and residual contraction is found after a wetting/drying cycle. These results confirm and provide a possible interpretation of some macroscopic phenomena.

Of mice and men: filling gaps in the TBC1D1 story

Of mice and men: filling gaps in the TBC1D1 story

The Residual Nonadrenergic Contractile Response to Nerve Stimulation of the Mouse Prostate Is Mediated by Acetylcholine but Not ATP in a Comparison with the Mouse Vas Deferens

Neuronal release of noradrenaline is primarily responsible for the contraction of prostatic smooth muscle in all species, and this forms the basis for the use of α(1)-adrenoceptor antagonists as pharmacotherapies for benign prostatic hyperplasia. Previous studies in mice have demonstrated that a residual nonadrenergic component to nerve stimulation remains after α(1)-adrenoceptor antagonism. In the guinea pig and rat prostate and the vas deferens of guinea pigs, rats, and mice, ATP is the mediator of this residual contraction. This study investigates the mediator of residual contraction in the mouse prostate. Whole prostates from wild-type, α(1A)-adrenoceptor, and P2X1-purinoceptor knockout mice were mounted in organ baths, and the isometric force that tissues developed in response to electrical field stimulation or exogenously applied agonists was recorded. Deletion of the P2X1 purinoceptor did not affect nerve-mediated contraction. Furthermore, the P2-purinoceptor antagonist suramin (30 μM) failed to attenuate nerve-mediated contractions in wild-type, α(1A)-adrenoceptor, or P2X1-purinoceptor knockout mice. Atropine (1 μM) attenuated contraction in prostates taken from wild-type mice. In the presence of prazosin (0.3 μM) or guanethidine (10 μM), or in prostates taken from α(1A)-adrenoceptor knockout mice, residual nerve-mediated contraction was abolished by atropine (1 μM), but not suramin (30 μM). Exogenously administered acetylcholine elicited reproducible concentration-dependent contractions of the mouse prostate that were atropine-sensitive (1 μM), but not prazosin-sensitive (0.3 μM). Acetylcholine, but not ATP, mediates the nonadrenergic component of contraction in the mouse prostate. This cholinergic component of prostatic contraction is mediated by activation of muscarinic receptors.

Heme Oxygenase-1 Deficiency Leads to Alteration of Soluble Guanylate Cyclase Redox Regulation

Heme oxygenase-1 knockout, H(mox)1(-/-), mice exhibit exacerbated vascular lesions after ischemia-reperfusion and mechanical injury. Surprisingly, we found no studies that reported contractile responses and sensitivity to vasorelaxants in H(mox)1(-/-) mice. The contractile responses [superior mesenteric arteries (SMA), from female H(mox)1(-/-) mice] exhibited increased sensitivity to phenylephrine (p < 0.001). Cumulative addition of acetylcholine relaxed SMA, with the residual contraction remaining 2 times higher in H(mox)1(-/-) mice (p < 0.001). Sodium nitroprusside (SNP, an NO donor) and 3-(5'-hydroxymethyl-2'-furyl)-1-benzyl indazole [YC-1; acts directly on soluble guanylate cyclase (sGC)] led to further relaxation, yet the residual contraction remained 2 to 3 times higher in H(mox)1(-/-) than H(mox)1(+/+) mice (p < 0.001). Branches from H(mox)1(-/-) mesenteric and renal arteries also showed reduced relaxation (p < 0.025). Relaxation of SMA was measured to 4-({(4-carboxybutyl) [2-(5-fluoro-2-{[4'-(trifluoromethyl) biphenyl-4-yl] methoxy}phenyl)ethyl]amino}benzoic acid (BAY 60-2770), which is a more effective activator of oxidized/heme-free sGC; and to 5-cyclopropyl-2-{1-(2-fluoro-benzyl)-1H-pyrazolo[3,4-b]pyridin-3-yl}-pyrimidin-4-ylamine (BAY 41-2272), a more effective stimulator of reduced sGC. H(mox)1(-/-) arteries were 15 times more sensitive to BAY 60-2770 (p < 0.025) than were H(mox)1(+/+) arteries. Pretreatment with 1H-[1,2,4]oxadiazolo[3,4-a]quinoxalin-1-one (ODQ), an oxidizer of sGC, predictably shifted the BAY 60-2770 response of H(mox)1(+/+) to the left (p < 0.01) and BAY 41-2272 response to the right (p < 0.01). ODQ had little effect on the responses of H(mox)1(-/-) arteries, indicating that much of sGC was oxidized/heme-free. Western analyses of sGC in SMA indicated that both α1 and β1 subunit levels were reduced to <50% of H(mox)1(+/+) level (p < 0.025). These findings support the hypothesis that the antioxidant function of H(mox)1 plays a significant role in the maintenance of sGC in a reduced state, which is resistant to degradation and is sensitive to NO. This function may be especially important in reducing vascular damage during ischemia-reperfusion injury.

High K+-induced contraction requires depolarization-induced Ca2+ release from internal stores in rat gut smooth muscle

Depolarization-induced contraction of smooth muscle is thought to be mediated by Ca2+ influx through voltage-gated L-type Ca2+channels. We describe a novel contraction mechanism that is independent of Ca2+ entry. Pharmacological experiments were carried out on isolated rat gut longitudinal smooth muscle preparations, measuring isometric contraction strength upon high K+-induced depolarization. Treatment with verapamil, which presumably leads to a conformational change in the channel, completely abolished K+-induced contraction, while residual contraction still occurred when Ca2+ entry was blocked with Cd2+. These results were further confirmed by measuring intracellular Ca2+ transients using Fura-2. Co-application of Cd2+ and the ryanodine receptor blocker DHBP further reduced contraction, albeit incompletely. Additional blockage of either phospholipase C (U 73122) or inositol 1,4,5-trisphophate (IP3)receptors (2-APB) abolished most contractions, while sole application of these blockers and Cd2+ (without parallel ryanodine receptor manipulation) also resulted in incomplete contraction block. We conclude that there are parallel mechanisms of depolarization-induced smooth muscle contraction via (a) Ca2+ entry and (b) Ca2+ entry-independent, depolarization-induced Ca2+-release through ryanodine receptors and IP3, with the latter being dependent on phospholipase C activation.

Heterogeneity in 5-HT-Induced Contractile and Proliferative Responses in Rat Pulmonary Arterial Bed

Aims: 5-Hydroxytryptamine (5-HT) is a potent vasoconstrictor and mitogen in the pulmonary vascular bed which exhibits phenotypical and functional heterogeneity according to size of the vessels. Methods: We thus investigated both contractile response and smooth muscle cell (SMC) proliferation in response to 5-HT in rat main extrapulmonary artery (MPA) and intrapulmonary arteries of the first and second order (IPA1 and IPA2). Results: The contractile effect of 5-HT was higher in IPA1 and IPA2 compared to MPA. 5-HT₂ receptor antagonists like ketanserin and ritanserin and a 5-HT_1B/D receptor antagonist, GR127935, partially inhibited the contraction. α-Methyl-5-HT, a 5-HT₂ receptor agonist, induced a higher contraction in MPA than in IPA and inversely 5-carboxamidotryptamine, a 5-HT₁ receptor agonist, induced a higher contraction in IPA2 than in MPA and IPA1. Nitrendipine reduced the contraction, whereas the addition of thapsigargin, an inhibitor of the sarcoplasmic reticulum Ca-ATPases, had an additive blocking effect only in IPA1. The residual contraction to 5-HT was abolished by Y-27632, a rho kinase inhibitor. Finally, SMC proliferation in response to 5-HT was higher in MPA than in IPA2. Conclusion: Our results demonstrate regional differences in SMC proliferation as well as in the functional role of 5-HT receptors and the sarcoplasmic reticulum in the contraction.

Effects of vibratory weld conditioning on residual stresses and transverse contraction distortions in multipass welding

For the full welded valve, the last procedure is welding, therefore, it is important to control the residual stresses and distortions in order to ensure spool rotation, valve watertightness, the stress corrosion resistance and non-deformability in active service. In the present study, effects of vibratory weld conditioning (VWC) on the residual stresses and transverse contraction distortions compared with normal welding were studied in submerged arc multipass welding. The results show that VWC can relieve the residual stresses greatly and make the distribution of residual stresses uniform. Moreover, VWC can also reduce transverse contraction distortions greatly. According to the analysis of microstructure and dynamic mechanical properties test, the reasons that VWC reduces the residual stresses and transverse contraction distortions were discussed.