Enhancing Resistance to Wetting Transition through the Concave Structures.

Water-repellent superhydrophobic surfaces are ubiquitous in nature. The fundamental understanding of bio/bio-inspired structures facilitates practical applications surmounting metastable superhydrophobicity. Typically, the hierarchical structure and/or reentrant morphology have been employed hitherto to suppress the Cassie-Baxter to Wenzel transition (CWT). Herein, a new design concept is reported, an effect of concave structure, which is vital for the stable superhydrophobic surface. The thermodynamic and kinetic stabilities of the concave pillars are evaluated by continuous exposure to various hydrostatic pressures and sudden impacts of water droplets with various Weber numbers (We), comparing them to the standard superhydrophobic normal pillars. Specifically, the concave pillar exhibits reinforced impact resistance preventing CWT below a critical We of ≈27.6, which is ≈1.6 times higher than that of the normal pillar (≈17.0). Subsequently, the stability of underwater air film (plastron) is investigated at various hydrostatic pressures. The results show that convex air caps formed at the concave cavities generate downward Laplace pressure opposing the exerted hydrostatic pressure between the pillars, thus impeding the hydrostatic pressure-dependent underwater air diffusion. Hence, the effects of trapped air caps contributing to the stable Cassie-Baxter state can offer a pioneering strategy for the exploration and utilization of superhydrophobic surfaces.

Multiple intramuscular ropivacaine injections to donor sites reduces pain in deep inferior epigastric artery perforator flap breast reconstruction.

INTRODUCTION: Local anesthetic infiltration at the surgical site has been studied in various surgical disciplines; however, its impact on deep inferior epigastric artery perforator (DIEP) flap breast reconstruction has not been previously assessed. This study aimed to evaluate the effects of multiple intramuscular ropivacaine injections on donor site pain during DIEP flap breast reconstruction. METHODS: The study included 65 patients who received local ropivacaine injections during DIEP reconstructions between March 2022 and February 2023, compared to 55 patients who underwent surgeries without ropivacaine from October 2018 to July 2020. A total of 20 cc of 0.75% ropivacaine solution was evenly administered at 20 sites along the abdominal wall muscles. The effect of intramuscular ropivacaine injection on postoperative visual analog scale (VAS) was evaluated using linear mixed-effect model. Opioid consumption and hospital days were also compared. RESULTS: The daily median VAS score was lower in the ropivacaine group (all p-values < 0.001). When analyzed using a linear mixed-effects model, those who received ropivacaine had significantly lower VAS scores over the first 5 days postoperatively (p-value < 0.001). The rate of VAS score decline was also faster in the ropivacaine group over the first 24 h postoperative (p-value = 0.045). Although opioid consumption was comparable between the groups, those receiving ropivacaine had significantly shorter hospital stay (p-value = 0.001) and no complications related to the injections were observed. CONCLUSION: Multiple intramuscular injections of ropivacaine to the donor site may reduce postoperative pain and shorten hospital stays, without increasing opioid consumption.

Strategies for the development of in vitro models of spinal cord ischemia-reperfusion injury: Oxygen-glucose deprivation and reoxygenation.

BACKGROUND: In vitro models tailored for spinal cord ischemia-reperfusion injury are pivotal for investigation of the mechanisms underlying spinal cord injuries. We conducted a two-phased study to identify the optimal conditions for establishing an in vitro model of spinal cord ischemia-reperfusion injury using primary rat spinal motor neurons. NEW METHOD: In the first phase, cell cultures were subjected to oxygen deprivation (OD) only, glucose deprivation (GD) only, or simultaneous deprivation of oxygen and glucose [oxygen-glucose deprivation (OGD)] for different durations (1, 2, and 6 h). In the second phase, different durations of re-oxygenation (1, 12, and 24 h) were applied after 1 h of OGD to determine the optimal duration simulating reperfusion injury. RESULTS AND COMPARISON WITH EXISTING METHOD(S): GD for 6 h significantly reduced cell viability (91 % of control, P<0.001) and increase cytotoxicity (111 % of control, P<0.001). OGD for 1 h and 2 h, resulted in a significant decrease in cell viability (80 % of control P<0.001, respectively), and increase in cytotoxicity (130 % of control, P<0.001, respectively). Re-oxygenation for 1, 12, and 24 h worsened ischemic injury following 1 h of OGD (all P<0.05). CONCLUSIONS: Our results may provide a valuable guide to devise in vitro models of spinal cord ischemia-reperfusion injury using primary spinal motor neurons.

Impact of Neoadjuvant Chemotherapy and Preoperative Irradiation on Early Complications in Direct-to-Implant Breast Reconstruction.

Background Impact of previous radiation therapy and neoadjuvant chemotherapy (NACT) on early complications in direct-to-implant (DTI) breast reconstruction has not been elucidated. This study investigated whether DTI reconstruction is viable in patients with NACT or a history of preoperative chest wall irradiation. Methods Medical records of breast cancer patients who underwent nipple-sparing or skin-sparing mastectomy with DTI breast reconstruction from March 2018 to February 2021, with at least 1 year of follow-up in a single tertiary center, were reviewed. Demographic data, intraoperative details, and postoperative complications, including full-thickness necrosis, infection, and removal, were reviewed. Risk factors suggested by previous literature, including NACT and preoperative chest wall irradiation histories, were reviewed by multivariate analysis. Results A total of 206 breast cancer patients were included, of which, 9 were bilateral, 8 patients (3.9%) had a history of prior chest wall irradiation, and 17 (8.6%) received NACT. From 215 cases, 11 cases (5.1%) required surgical intervention for full-thickness necrosis, while intravenous antibiotics or hospitalization was needed in 11 cases (5.1%), with 14 cases of failure (6.5%) reported. Using multivariable analysis, preoperative irradiation was found to significantly increase the risk of full-thickness skin necrosis (OR = 12.14, p = 0.034), and reconstruction failure (OR = 13.14, p = 0.005). NACT was not a significant risk factor in any of the above complications. Conclusion DTI breast reconstruction is a viable option for patients who have received NACT, although reconstructive options should be carefully explored for patients with a history of breast irradiation.

Protective Effects of 7S,15R-Dihydroxy-16S,17S-Epoxy-Docosapentaenoic Acid (diHEP-DPA) against Blue Light-Induced Retinal Damages in A2E-Laden ARPE-19 Cells.

The purpose of this study was to investigate the protective effects of 7S,15R-dihydroxy-16S,17S-epoxy-docosapentaenoic acid (diHEP-DPA) in retinal pigment epithelial (RPE) cell damage. ARPE-19 cells, a human RPE cell line, were cultured with diHEP-DPA and Bis-retinoid N-retinyl-N-retinylidene ethanolamine (A2E), followed by exposure to BL. Cell viability and cell death rates were determined. Western blotting was performed to determine changes in apoptotic factors, mitogen-activated protein kinase (MAPK) family proteins, inflammatory proteins, and oxidative and carbonyl stresses. The levels of pro-inflammatory cytokines in the culture medium supernatants were also measured. Exposure to A2E and BL increased the ARPE-19 cell death rate, which was alleviated by diHEP-DPA in a concentration-dependent manner. A2E and BL treatments induced apoptosis in ARPE-19 cells, which was also alleviated by diHEP-DPA. Analysis of the relationship with MAPK proteins revealed that the expression of p-JNK and p-P38 increased after A2E and BL treatments and decreased with exposure to diHEP-DPA in a concentration-dependent manner. DiHEP-DPA also affected the inflammatory response by suppressing the expression of inflammatory proteins and the production of pro-inflammatory cytokines. Furthermore, it was shown that diHEP-DPA regulated the proteins related to oxidative and carbonyl stresses. Taken together, our results provide evidence that diHEP-DPA can inhibit cell damage caused by A2E and BL exposure at the cellular level by controlling various pathways involved in apoptosis and inflammatory responses.

Perfusion area versus volume of the DIEP flap: A multivariable analysis of perforator and flap characteristics for estimation of perfusion area and volume.

BACKGROUND: The extent of perfusion of a deep inferior epigastric artery perforator (DIEP) flap is a primary concern for surgeons. This study aimed to determine whether the flap area or volume can be estimated using perforator and flap characteristics. METHODS: Intraoperative flap perfusion was assessed using indocyanine green angiography in patients who underwent DIEP flap breast reconstruction between November 2018 and February 2023. The area perfused by a single dominant perforator was delineated on the surface of the flap and measured using the ImageJ software. Multiple linear regression analysis was conducted to estimate the 'perfusion ratio,' defined as the perfused area divided by the total flap area. Potential predictor variables included flap size (cm2), flap thickness (mm), perforator diameter (mm), perforator rows (medial/lateral), vertical location of perforator (at or above/below the umbilicus), and perforator eccentricity (vertical distance from upper flap margin to perforator, cm). RESULTS: In total, 101 patients were included in this analysis. The mean 'perfusion ratio' was 67.8% ± 11.5%, predicted by perforator diameter (p = 0.022) and vertical location below umbilicus (p < 0.001) with positive correlations and negatively correlated with flap thickness (p = 0.003) in the multivariable analysis. Both perfusion area and weight were predicted by perforator diameter, vertical location of perforator, flap size, and flap thickness (p < 0.001). The coefficient of determination (adjusted R2) for prediction of perfusion weight was higher than that for the perfusion area (75.5% vs. 69.4%). CONCLUSIONS: Flap volume, rather than area, is determined by a perforator of a given diameter and location.

Acute Sympathetic Blockade Improves Insulin-Mediated Microvascular Blood Flow in the Forearm of Adult Human Subjects With Obesity.

BACKGROUND: Obesity is associated with resistance to the metabolic (glucose uptake) and vascular (nitric-oxide mediated dilation and microvascular recruitment) actions of insulin. These vascular effects contribute to insulin sensitivity by increasing tissue delivery of glucose. Studies by us and others suggest that sympathetic activation contributes to insulin resistance to glucose uptake. Here we tested the hypothesis that sympathetic activation contributes to impaired insulin-mediated vasodilation in adult subjects with obesity. METHODS AND RESULTS: In a randomized crossover study, we used a euglycemic hyperinsulinemic clamp in 12 subjects with obesity to induce forearm arterial vasodilation (forearm blood flow) and microvascular recruitment (contrast-enhanced ultrasonography) during an intrabrachial infusion of saline (control) or phentolamine (sympathetic blockade). Insulin increased forearm blood flow on both study days (from 2.21±1.22 to 4.89±4.21 mL/100 mL per min, P=0.003 and from 2.42±0.89 to 7.19±3.35 mL/100 mL per min, P=0.002 for the intact and blocked day, respectively). Sympathetic blockade with phentolamine resulted in a significantly greater increase in microvascular flow velocity (∆microvascular flow velocity: 0.23±0.65 versus 2.51±3.01 arbitrary intensity units (AIU/s) for saline and phentolamine respectively, P=0.005), microvascular blood volume (∆microvascular blood volume: 1.69±2.45 versus 3.76±2.93 AIU, respectively, P=0.05), and microvascular blood flow (∆microvascular blood flow: 0.28±0.653 versus 2.51±3.01 AIU2/s, respectively, P=0.0161). To evaluate if this effect was not due to nonspecific vasodilation, we replicated the study in 6 subjects with obesity comparing intrabrachial infusion of phentolamine to sodium nitroprusside. At doses that produced similar increases in forearm blood flow, insulin-induced changes in microvascular flow velocity were greater during phentolamine than sodium nitroprusside (%microvascular flow velocity=58% versus 29%, respectively, P=0.031). CONCLUSIONS: We conclude that sympathetic activation impairs insulin-mediated microvascular recruitment in adult subjects with obesity.

Efficient Deep-Blue Light-Emitting Diodes Through Decoupling of Colloidal Perovskite Quantum Dots.

Metal halide perovskite light-emitting diodes (PeLEDs) have exceptional color purity but designs that emit deep-blue color with high efficiency have not been fully achieved and become more difficult in the thin film of confined perovskite colloidal quantum dots (PeQDs) due to particle interaction. Here it is demonstrated that electronic coupling and energy transfer in PeQDs induce redshift in the emission by PeQD film, and consequently hinder deep-blue emission. To achieve deep-blue emission by avoiding electronic coupling and energy transfer, a QD-in-organic solid solution is introduced to physically separate the QDs in the film. This physical separation of QDs reduces the interaction between them yielding a blueshift of ≈7 nm in the emission spectrum. Moreover, using a hole-transporting organic molecule with a deep-lying highest occupied molecular orbital (≈6.0 eV) as the organic matrix, the formation of exciplex emission is suppressed. As a result, an unprecedently high maximum external quantum efficiency of 6.2% at 462 nm from QD-in-organic solid solution film in PeLEDs is achieved, which satisfies the deep-blue color coordinates of CIEy < 0.06. This work suggests an important material strategy to deepen blue emission without reducing the particle size to <≈4 nm.

Effects of neuromuscular block reversal with neostigmine/glycopyrrolate versus sugammadex on bowel motility recovery after laparoscopic colorectal surgery: A randomized controlled trial.

STUDY OBJECTIVE: To compare the effects of neostigmine/glycopyrrolate (a traditional agent) and sugammadex on bowel motility recovery and the occurrence of digestive system complications after colorectal surgery. DESIGN: Prospective, randomized controlled trial. SETTING: A single tertiary center. PATIENTS: 111 patients undergoing laparoscopic colorectal surgery. INTERVENTIONS: Patients were randomized into two groups based on the block reversal agent: 1) a mixture of 50 µg.kg-1 of neostigmine and 10 µg.kg-1 of glycopyrrolate (neostigmine group) and 2) 2 mg.kg-1 of sugammadex (sugammadex group). MEASUREMENTS: The primary outcome was the time from the surgery's completion to the first flatus. The time to the first postoperative defecation, incidences of postoperative nausea or vomiting, ileus, and dry mouth, as well as postoperative length of stay, were also assessed. MAIN RESULTS: The time to the first flatus was significantly shorter in the sugammadex group than in the neostigmine group (59 [42-79] h vs 69 [53-90] h, P = 0.027). The time to the first defecation and the incidences of postoperative nausea or vomiting and ileus did not differ between the groups, nor did the postoperative length of stay. However, the incidence of postoperative dry mouth was significantly lower in the sugammadex group than in the neostigmine group (7 patients [13%] vs 39 patients [71%], P < 0.001). CONCLUSIONS: The time to the first flatus was shorter using 2 mg.kg-1 sugammadex to reverse the neuromuscular block for laparoscopic colorectal surgery compared to reversal with conventional neostigmine/glycopyrrolate.

Virtual reality vs. Tablet video for venipuncture education in children: A randomized clinical trial.

Pediatric patients usually experience high levels of pain and distress due to venipuncture. This randomised study aimed to evaluate the effects of virtual reality-based preprocedural education in comparison with video-based education in terms of pain and distress experienced by children scheduled to undergo venipuncture. Ninety children aged 4-8 years who were scheduled to undergo venipuncture surgery were randomly assigned to either a video or virtual reality group. Children in the video group received preprocedural education on venipuncture via a video displayed on a tablet and those in the virtual reality group received the same education via a head-mounted virtual reality display unit. The educational content for the two groups was identical. An independent assessor blinded to the group assignment observed the children's behavior and determined their Children's Hospital of Eastern Ontario Pain Scale scores, parental satisfaction score, procedure-related outcomes, venipuncture time, number of repeated procedures and difficulty score for the procedure. The virtual reality group experienced less pain and distress, as indicated by their Children's Hospital of Eastern Ontario Pain Scale scores compared with the video group (5.0 [5.0-8.0] vs. 7.0 [5.0-9.0], P = 0.027). There were no significant intergroup differences in parental satisfaction scores or procedure-related outcomes. For pediatric patients scheduled to undergo venipuncture, preprocedural education via a head-mounted display for immersive virtual reality was more effective compared with video-based education via a tablet in terms of reducing pain and distress.

Surface-binding molecular multipods strengthen the halide perovskite lattice and boost luminescence.

Reducing the size of perovskite crystals to confine excitons and passivating surface defects has fueled a significant advance in the luminescence efficiency of perovskite light-emitting diodes (LEDs). However, the persistent gap between the optical limit of electroluminescence efficiency and the photoluminescence efficiency of colloidal perovskite nanocrystals (PeNCs) suggests that defect passivation alone is not sufficient to achieve highly efficient colloidal PeNC-LEDs. Here, we present a materials approach to controlling the dynamic nature of the perovskite surface. Our experimental and theoretical studies reveal that conjugated molecular multipods (CMMs) adsorb onto the perovskite surface by multipodal hydrogen bonding and van der Waals interactions, strengthening the near-surface perovskite lattice and reducing ionic fluctuations which are related to nonradiative recombination. The CMM treatment strengthens the perovskite lattice and suppresses its dynamic disorder, resulting in a near-unity photoluminescence quantum yield of PeNC films and a high external quantum efficiency (26.1%) of PeNC-LED with pure green emission that matches the Rec.2020 color standard for next-generation vivid displays.

Automated Laryngeal Invasion Detector of Boluses in Videofluoroscopic Swallowing Study Videos Using Action Recognition-Based Networks.

We aimed to develop an automated detector that determines laryngeal invasion during swallowing. Laryngeal invasion, which causes significant clinical problems, is defined as two or more points on the penetration-aspiration scale (PAS). We applied two three-dimensional (3D) stream networks for action recognition in videofluoroscopic swallowing study (VFSS) videos. To detect laryngeal invasion (PAS 2 or higher scores) in VFSS videos, we employed two 3D stream networks for action recognition. To establish the robustness of our model, we compared its performance with those of various current image classification-based architectures. The proposed model achieved an accuracy of 92.10%. Precision, recall, and F1 scores for detecting laryngeal invasion (≥PAS 2) in VFSS videos were 0.9470 each. The accuracy of our model in identifying laryngeal invasion surpassed that of other updated image classification models (60.58% for ResNet101, 60.19% for Swin-Transformer, 63.33% for EfficientNet-B2, and 31.17% for HRNet-W32). Our model is the first automated detector of laryngeal invasion in VFSS videos based on video action recognition networks. Considering its high and balanced performance, it may serve as an effective screening tool before clinicians review VFSS videos, ultimately reducing the burden on clinicians.

Effect of magnetic microbeads on sustained and targeted delivery of transforming growth factor-beta-1 for rotator cuff healing in a rat rotator cuff repair model.

Structural failure is a well-established complication of rotator cuff repair procedures. To evaluate the effect of magnetic microbeads, designed for precise drug delivery via magnetic force, on sustained transforming growth factor-beta-1 (TGF-ß1) release and rotator cuff healing in a rat rotator cuff repair model. TGF-ß1 laden microbeads were prepared, and baseline in vitro experiments included the magnetization of the microbeads and TGF-ß1 release tests. In an in vivo experiment using a rat rotator cuff repair model on both shoulders, 72 rats were randomly assigned to three groups (24 per group): group A, conventional repair; group B, repair with and simple TGF-ß1 injection; and group C, repair with magnet insertion into the humeral head and TGF-ß1 laden microbead injection. Delivery of TGF-ß1 was evaluated at 1 and 7 days after the intervention using PCR, Western blot, and immunohistochemistry. At 6 weeks post-intervention, rotator cuff healing was assessed using biomechanical and histological analysis. The in vitro experiments confirmed the magnetization property of the microbeads and sustained delivery of TGF-ß1 for up to 10 days. No difference in the TGF-ß1 expression was found at day 1 in vivo. However, at day 7, group C exhibited a significantly elevated expression of TGF-ß1 in both PCR and Western blot analyses compared to groups A and B (all P < 0.05). Immunohistochemical analysis revealed a higher expression of TGF-ß1 at the repair site in group C on day 7. At 6 weeks, biomechanical analysis demonstrated a significantly higher ultimate failure load in group C than in groups A and B (P < 0.05) and greater stiffness than in group A (P = 0.045). In addition, histological analysis showed denser and more regular collagen fibers with complete continuity to the bone in group C than in groups A and B, a statistically significant difference according to the semi-quantitative scoring system (all P < 0.05). The use of the TGF-ß1 laden magnetic microbeads demonstrated sustained delivery of TGF-ß1 to the repair site, improving rotator cuff healing.

Comparison of the rate of concomitant proximal venous stenosis between the upper and lower extremities in patients with secondary lymphedema undergoing lymphaticovenous anastomosis.

BACKGROUND: Concomitant iatrogenic proximal venous stenosis increases venous pressure and can be a risk factor for unfavorable outcomes of lymphaticovenular anastomosis (LVA) in extremities with secondary lymphedema. This study investigated the frequency and relevant factors of venous stenosis in patients diagnosed with secondary lymphedema who underwent LVA. METHODS: Patients who underwent preoperative computed tomographic venography (CTV) and LVA for secondary lymphedema of the extremities from October 2018 to March 2022 were included. The incidence of proximal venous stenosis in the affected limb on preoperative CTV and the rate of endovascular intervention were compared between upper and lower extremities. Factors affecting proximal venous stenosis were identified through multivariable analysis using independent variables, including patient age, body mass index, comorbidities, smoking history, radiation therapy, duration of lymphedema, and location of lymphedema. RESULTS: A total of 211 patients were analyzed, including 83 patients with upper extremity and 128 patients with lower extremity lymphedema. The incidence of proximal venous stenosis in the preoperative CTV was 32.5% and 7.8% in upper extremity, and lower extremity lymphedema, respectively (P < .001). The incidence of venous stenosis requiring endovascular intervention was significantly higher in the upper extremity compared with the lower extremity (16.9% vs 6.3%; P = .014). In multivariable analysis, risk factors affecting incidence of venous stenosis requiring endovascular intervention was the patient age (P = .007) and upper extremity (P = .009). CONCLUSIONS: Preoperative evaluation and treatment of venous stenosis in extremities with secondary lymphedema are necessary before LVA surgery, particularly in upper extremity lymphedema.

Stretchable Electrodes for Interconnects in Soft Electronics.

Soft electronics have significantly enhanced user convenience and data accuracy in wearable devices, implantable devices, and human-machine interfaces. However, a persistent challenge in their development has been the disconnection between the rigid and soft components of devices due to the substantial difference in modulus and stretchability. To address this issue, establishing a durable and flexible connection that smoothly links components of varying stiffness to signal-capturing sections with a lower stiffness is essential. In this study, we developed a novel stretchable interconnect that strongly adheres to various materials, facilitating electrical connections effortlessly by applying minimal finger pressure. Capable of stretching up to 1000% while maintaining electrical integrity, this interconnect proves its applicability across multiple domains, including electrocardiogram (ECG), electromyography (EMG), and stretchable light-emitting diode (LED) circuits. Its versatility is further demonstrated through its compatibility with various manufacturing techniques such as 3D printing, painting, and spin coating, highlighting its adaptability in soft electronics.

Dual-polarization MZM-based photonic nonlinear analog self-interference cancellation for in-band full-duplex radios.

In this paper, we propose a dual-polarization Mach-Zehnder modulator-based photonic nonlinear analog self-interference cancellation (SIC) technique for in-band full duplex (IBFD) systems. By using the proposed technique, an arbitrary 4th order nonlinear transfer function can be generated, meaning the performance limitation caused by the nonlinearity of the analog SIC circuit can be overcome by imitating the nonlinear transfer function of the analog SIC circuit before cancellation. This paper also presents a performance analysis through simulations and the results of a proof-of-concept demonstration. In the experiment, the proposed nonlinear SIC technique could achieve 29 dB cancellation over 500 MHz bandwidth centered at 1.25 GHz frequency along various degree of distortion caused by nonlinearity. In addition, the performance enhancements achieved by the proposed technique are evaluated in terms of error vector magnitudes (EVMs) and constellations of the signal-of-interest (SOI) in the simulation which is based on the experimental SIC results. More than 3 dB of SOI power gain could be obtained in evaluated EVM performances.

On-Chip Annealing Using Embedded Micro-Heater for Highly Sensitive and Selective Gas Detection.

The demand for gas sensing systems that enable fast and precise gas recognition is growing rapidly. However, substantial challenges arise from the complex fabrication process of sensor arrays, time-consuming data transmission to an external processor, and high energy consumption in multi-stage data processing. In this study, a gas sensing system using on-chip annealing for fast and power-efficient gas detection is proposed. By utilizing a micro-heater embedded in the gas sensor, the sensing material of adjacent sensors in the same substrate can be easily varied without further fabrication steps. The response to oxidizing gas is constrained in metal oxide (MOX) sensing material with small grain sizes, as the depletion width of grain cannot extend beyond the grain size during the gas reaction. On the other hand, the response to reducing gases and humidity, which decrease the depletion width, is less affected by grain sizes. A readout circuit integrating a differential amplifier and dual FET-type gas sensors effectively emphasizes the response to oxidizing gases by canceling the response to reducing gases and humidity. The selective on-chip annealing method is applicable to various MOX sensing materials, demonstrating its potential for application in commercial fields due to its simplicity and expandability.

Ventral Tegmental Area Amylin Receptor Activation Differentially Modulates Mesolimbic Dopamine Signaling in Response to Fat versus Sugar.

Amylin, a pancreatic hormone that is cosecreted with insulin, has been highlighted as a potential treatment target for obesity. Amylin receptors are distributed widely throughout the brain and are coexpressed on mesolimbic dopamine neurons. Activation of amylin receptors is known to reduce food intake, but the neurochemical mechanisms behind this remain to be elucidated. Amylin receptor activation in the ventral tegmental area (VTA), a key dopaminergic nucleus in the mesolimbic reward system, has a potent ability to suppress intake of palatable fat and sugar solutions. Although previous work has demonstrated that VTA amylin receptor activation can dampen mesolimbic dopamine signaling elicited by random delivery of sucrose, whether this is also the case for fat remains unknown. Herein we tested the hypothesis that amylin receptor activation in the VTA of male rats would attenuate dopamine signaling in the nucleus accumbens core in response to random intraoral delivery of either fat or sugar solutions. Results show that fat solution produces a greater potentiation of accumbens dopamine than an isocaloric sucrose solution. Moreover, activation of VTA amylin receptors elicits a more robust suppression of accumbens dopamine signaling in response to fat solution than to sucrose. Taken together these results shed new light on the amylin system as a therapeutic target for obesity and emphasize the reinforcing nature of high-fat/high-sugar diets.

Threshold learning algorithm for memristive neural network with binary switching behavior.

On-chip learning is an effective method for adjusting artificial neural networks in neuromorphic computing systems by considering hardware intrinsic properties. However, it faces challenges due to hardware nonidealities, such as the nonlinearity of potentiation and depression and limitations on fine weight adjustment. In this study, we propose a threshold learning algorithm for a variation-tolerant ternary neural network in a memristor crossbar array. This algorithm utilizes two tightly separated resistance states in memristive devices to represent weight values. The high-resistance state (HRS) and low-resistance state (LRS) defined as read current of < 0.1 µA and > 1 µA, respectively, were successfully programmed in a 32 × 32 crossbar array, and exhibited half-normal distributions due to the programming method. To validate our approach experimentally, a 64 × 10 single-layer fully connected network were trained in the fabricated crossbar for an 8 × 8 MNIST dataset using the threshold learning algorithm, where the weight value is updated when a gradient determined by backpropagation exceeds a threshold value. Thanks to the large margin between the two states of the memristor, we observed only a 0.42 % drop in classification accuracy compared to the baseline network results. The threshold learning algorithm is expected to alleviate the programming burden and be utilized in variation-tolerant neuromorphic architectures.

Effect of universal adhesive pretreatments on the bond strength durability of conventional and adhesive resin cements to zirconia ceramic.

PURPOSE: This study aimed to evaluate the effect of pretreatment of three different universal adhesives (Single Bond Universal [SBU], All-Bond Universal [ABU], and Prime&Bond universal [PBU]) on the bonding durability of an adhesive (Panavia F 2.0, PF) and a conventional (Duo-Link, DL) resin cements to air-abraded zirconia. MATERIALS AND METHODS: Rectangular-shaped zirconia specimens were prepared. The chemical composition and surface energy parameters of the materials were studied by Fourier transform infrared spectroscopy and contact angle measurement, respectively. To evaluate resin bonding to the zirconia, all the bonding specimens were immersed in water for 24 h and the specimens to be aged were additionally thermocycled 10000 times before the shear bond strength (SBS) test. RESULTS: The materials showed different surface energy parameters, including the degree of hydrophilicity/hydrophobicity. While the DL/CON (no pretreatment) showed the lowest SBS and a significant decrease in the value after thermocycling (P < .001), the PF/CON obtained a higher SBS value than the DL/CON (P < .001) and no decrease even after thermocycling (P = .839). When the universal adhesives were used with DL, their SBS values were higher than the CON (P < .05), but the trend was adhesive-specific. In conjunction with PF, the PF/SBU produced the highest SBS followed by the PF/ABU (P = .002), showing no significant decrease after thermocycling (P > .05). The initial SBS of the PF/PBU was similar to the PF/CON (P = .999), but the value decreased after thermocycling (P < .001). CONCLUSION: The universal adhesive pretreatment did not necessarily show a synergistic effect on the bonding performance of an adhesive resin cement, whereas the pretreatment was beneficial to bond strength and durability of a conventional resin cement.