Thermodynamic Origin-Based In Situ Electrochemical Construction of Reversible p-n Heterojunctions for Optimal Stability in Potassium Ion Storage.

Heterojunctions in electrode materials offer diverse improvements during the cycling process of energy storage devices, such as volume change buffering, accelerated ion/electron transfer, and better electrode structure integrity, however, obtaining optimal heterostructures with nanoscale domains remains challenging within constrained materials. A novel in situ electrochemical method is introduced to develop a reversible CuSe/PSe p-n heterojunction (CPS-h) from Cu3 PSe4 as starting material, targeting maximum stability in potassium ion storage. The CPS-h formation is thermodynamically favorable, characterized by its superior reversibility, minimized diffusion barriers, and enhanced conversion post K+ interaction. Within CPS-h, the synergy of the intrinsic electric field and P-Se bonds enhance electrode stability, effectively countering the Se shuttling phenomenon. The specific orientation between CuSe and PSe leads to a 35° lattice mismatch generates large space at the interface, promoting efficient K ion migration. The Mott-Schottky analysis validates the consistent reversibility of CPS-h, underlining its electrochemical reliability. Notably, CPS-h demonstrates a negligible 0.005% capacity reduction over 10,000 half-cell cycles and remains stable through 2,000 and 4,000 cycles in full cells and hybrid capacitors, respectively. This study emphasizes the pivotal role of electrochemical dynamics in formulating highly stable p-n heterojunctions, representing a significant advancement in potassium-ion battery (PIB) electrode engineering.

Enhancing surgical outcomes of posterior iliac bone harvesting through a pivotal modification.

Traditionally, patients are positioned in the prone position to access the donor site during the posterior iliac bone graft harvesting procedure. However, this well-established method is associated with complications such as pressure injuries, displacement of the endotracheal tube and intravenous catheter, and blindness. Moreover, the process of turning patients 180° between the supine and prone positions is both laborious and time consuming. However, no updates have been made in the approaches published in the literature to counteract these problems. Therefore, to overcome these challenges and improve patient outcomes, we proposed a pivotal modification: change prone position to the lateral decubitus position. This approach allowed us to effectively avoid the aforementioned complications. In addition, this modification offered significant advantages, including ease of implementation and timesaving benefits. The article presented results of the modification and a comprehensive evaluation of clinical and anesthetic considerations comparing the two methods.

Development of a Machine Learning Algorithm to Correlate Lumbar Disc Height on X-rays with Disc Bulging or Herniation.

Lumbar disc bulging or herniation (LDBH) is one of the major causes of spinal stenosis and related nerve compression, and its severity is the major determinant for spine surgery. MRI of the spine is the most important diagnostic tool for evaluating the need for surgical intervention in patients with LDBH. However, MRI utilization is limited by its low accessibility. Spinal X-rays can rapidly provide information on the bony structure of the patient. Our study aimed to identify the factors associated with LDBH, including disc height, and establish a clinical diagnostic tool to support its diagnosis based on lumbar X-ray findings. In this study, a total of 458 patients were used for analysis and 13 clinical and imaging variables were collected. Five machine-learning (ML) methods, including LASSO regression, MARS, decision tree, random forest, and extreme gradient boosting, were applied and integrated to identify important variables for predicting LDBH from lumbar spine X-rays. The results showed L4-5 posterior disc height, age, and L1-2 anterior disc height to be the top predictors, and a decision tree algorithm was constructed to support clinical decision-making. Our study highlights the potential of ML-based decision tools for surgeons and emphasizes the importance of L1-2 disc height in relation to LDBH. Future research will expand on these findings to develop a more comprehensive decision-supporting model.

Harnessing 2D Ruddlesden-Popper Perovskite with Polar Organic Cation for Ultrasensitive Multibit Nonvolatile Transistor-Type Photomemristors.

Photomemristors have been regarded as one of the most promising candidates for next-generation hardware-based neuromorphic computing due to their potentials of fast data transmission and low power consumption. However, intriguingly, so far, photomemristors seldom display truly nonvolatile memory characteristics with high light sensitivity. Herein, we demonstrate ultrasensitive photomemristors utilizing two-dimensional (2D) Ruddlesden-Popper (RP) perovskites with a highly polar donor-acceptor-type push-pull organic cation, 4-(5-(2-aminoethyl)thiophen-2-yl)benzonitrile+ (EATPCN+), as charge-trapping layers. High linearity and almost zero-decay retention are observed in (EATPCN)2PbI4 devices, which are very distinct from that of the traditional 2D RP perovskite devices consisting of nonpolar organic cations, such as phenethylamine+ (PEA+) and octylamine+ (OA+), and traditional 3D perovskite devices consisting of methylamine+ (MA+). The 2-fold advantages, including desirable spatial crystal arrangement and engineered energetic band alignment, clarify the mechanism of superior performance in (EATPCN)2PbI4 devices. The optimized (EATPCN)2PbI4 photomemristor also shows a memory window of 87.9 V and an on/off ratio of 106 with a retention time of at least 2.4 × 105 s and remains unchanged after >105 writing-reading-erasing-reading endurance cycles. Very low energy consumptions of 1.12 and 6 fJ for both light stimulation and the reading process of each status update are also demonstrated. The extremely low power consumption and high photoresponsivity were simultaneously achieved. The high photosensitivity surpasses that of a state-of-the-art commercial pulse energy meter by several orders of magnitude. With their outstanding linearity and retention, rabbit images have been rebuilt by (EATPCN)2PbI4 photomemristors, which truthfully render the image without fading over time. Finally, by utilizing the powerful ∼8 bits of nonvolatile potentiation and depression levels of (EATPCN)2PbI4 photomemristors, the accuracies of the recognition tasks of CIFAR-10 image classification and MNIST handwritten digit classification have reached 89% and 94.8%, respectively. This study represents the first report of utilizing a functional donor-acceptor type of organic cation in 2D RP perovskites for high-performance photomemristors with characteristics that are not found in current halide perovskites.

Highly Efficient MAPbI3 -Based Quantum Dots Exhibiting Unusual Nonblinking Single Photon Emission at Room Temperature.

Highly emissive semiconductor nanocrystals, or so-called quantum dots (QDs) possess a variety of applications from displays and biology labeling, to quantum communication and modern security. Though ensembles of QDs have already shown very high photoluminescent quantum yields (PLQYs) and have been widely utilized in current optoelectronic products, QDs that exhibit high absorption cross-section, high emission intensity, and, most important, nonblinking behavior at single-dot level have long been desired and not yet realized at room temperature. In this work, infrared-emissive MAPbI3 -based halide perovskite QDs is demonstrated. These QDs not only show a ≈100% PLQY at the ensemble level but also, surprisingly, at the single-dot level, display an extra-large absorption cross-section up to 1.80 × 10-12 cm2 and non-blinking single photon emission with a high single photon purity of 95.3%, a unique property that is extremely rare among all types of quantum emitters operated at room temperature. An in-depth analysis indicates that neither trion formation nor band-edge carrier trapping is observed in MAPbI3 QDs, resulting in the suppression of intensity blinking and lifetime blinking. Fluence-dependent transient absorption measurements reveal that the coexistence of non-blinking behavior and high single photon purity in these perovskite QDs results from a significant repulsive exciton-exciton interaction, which suppresses the formation of biexciton, and thus greatly reduces photocharging. The robustness of these QDs is confirmed by their excellent stability under continuous 1 h electron irradiation in high-resolution transmission electron microscope inspection. It is believed that these results mark an important milestone in realizing nonblinking single photon emission in semiconductor QDs.

Data-driven, two-stage machine learning algorithm-based prediction scheme for assessing 1-year and 3-year mortality risk in chronic hemodialysis patients.

Life expectancy is likely to be substantially reduced in patients undergoing chronic hemodialysis (CHD). However, machine learning (ML) may predict the risk factors of mortality in patients with CHD by analyzing the serum laboratory data from regular dialysis routine. This study aimed to establish the mortality prediction model of CHD patients by adopting two-stage ML algorithm-based prediction scheme, combined with importance of risk factors identified by different ML methods. This is a retrospective, observational cohort study. We included 800 patients undergoing CHD between December 2006 and December 2012 in Shin-Kong Wu Ho-Su Memorial Hospital. This study analyzed laboratory data including 44 indicators. We used five ML methods, namely, logistic regression (LGR), decision tree (DT), random forest (RF), gradient boosting (GB), and eXtreme gradient boosting (XGB), to develop a two-stage ML algorithm-based prediction scheme and evaluate the important factors that predict CHD mortality. LGR served as a bench method. Regarding the validation and testing datasets from 1- and 3-year mortality prediction model, the RF had better accuracy and area-under-curve results among the five different ML methods. The stepwise RF model, which incorporates the most important factors of CHD mortality risk based on the average rank from DT, RF, GB, and XGB, exhibited superior predictive performance compared to LGR in predicting mortality among CHD patients over both 1-year and 3-year periods. We had developed a two-stage ML algorithm-based prediction scheme by implementing the stepwise RF that demonstrated satisfactory performance in predicting mortality in patients with CHD over 1- and 3-year periods. The findings of this study can offer valuable information to nephrologists, enhancing patient-centered decision-making and increasing awareness about risky laboratory data, particularly for patients with a high short-term mortality risk.

Unleashing the Power of 2D MoS2: In Situ TEM Study of Its Potential as Diffusion Barriers in Ru Interconnects.

This study presents the utilization of MoS2 as a diffusion barrier for metal interconnects, in situ transmission electron microscopy (TEM) observations are employed for comprehensive understanding. The diffusion-blocking ability of MoS2 is discussed by the diffusion and phase transformation between Ru and Si via TEM diffraction and imaging. When the sample is heated to a high temperature such that MoS2 loses the ability to block the diffusion, Si diffuses through the MoS2 into the Ru layer, leading to the formation of Ru2Si3. Both multilayer and monolayer (1L) MoS2 exhibit exceptional diffusion-blocking ability up to 800 °C. Furthermore, plasma-treated 1L-MoS2 shows a slightly low diffusion-blocking temperature of 750 °C, while the dangling bonds in MoS2 improve the interfacial adhesion. These findings suggest that MoS2 holds great potential as a diffusion barrier for metal interconnects.

Probing the sublimation kinetics of Ag, Ag@TiO2, and Ag@C nanoparticles.

In this study, we used an in situ transmission electron microscopy (TEM) heating system to investigate the sublimation-induced morphological changes of cubic Ag nanoparticles (NPs) and Ag-based core-shell structures and the influence of shell coverage on the thermal stability. In contrast to previous research performed with small Ag nanoparticles (<30 nm), here we found that large-particle Ag NPs (>50 nm) underwent a three-stage sublimation-induced morphological change at 800 °C, in the sequence uniform (I)-nonuniform (II)-uniform (III) sublimation. The (110) and (100) planes were the main sublimation planes during stages I and II. When the reaction reached stage III, the sublimation rate decreased as a result of an increase in the sublimation energy barrier. For core-shell NPs, the sublimation process began with stage II. For Ag NPs presenting TiO2 shells, the sublimation process was initiated at a relatively low temperature (700-750 °C) because of a local heating effect; for Ag NPs with carbon shells, the reaction was suppressed through surface atom passivation, thereby enhancing the thermal stability.

Vacuum-Deposited Inorganic Perovskite Light-Emitting Diodes with External Quantum Efficiency Exceeding 10% via Composition and Crystallinity Manipulation of Emission Layer under High Vacuum.

Although vacuum-deposited metal halide perovskite light-emitting diodes (PeLEDs) have great promise for use in large-area high-color-gamut displays, the efficiency of vacuum-sublimed PeLEDs currently lags that of solution-processed counterparts. In this study, highly efficient vacuum-deposited PeLEDs are prepared through a process of optimizing the stoichiometric ratio of the sublimed precursors under high vacuum and incorporating ultrathin under- and upper-layers for the perovskite emission layer (EML). In contrast to the situation in most vacuum-deposited organic light-emitting devices, the properties of these perovskite EMLs are highly influenced by the presence and nature of the upper- and presublimed materials, thereby allowing us to enhance the performance of the resulting devices. By eliminating Pb° formation and passivating defects in the perovskite EMLs, the PeLEDs achieve an outstanding external quantum efficiency (EQE) of 10.9% when applying a very smooth and flat geometry; it reaches an extraordinarily high value of 21.1% when integrating a light out-coupling structure, breaking through the 10% EQE milestone of vacuum-deposited PeLEDs.

Enhanced Piezocatalytic Activity in Bi1/2Na1/2TiO3 for Water Splitting by Oxygen Vacancy Engineering.

Piezoelectric materials have demonstrated applicability in clean energy production and environmental wastewater remediation through their ability to initiate a number of catalytic reactions. In this study, we used a conventional sol-gel method to synthesize lead-free rhombohedral R3c bismuth sodium titanate (BNT) particles of various sizes. When used as a piezocatalyst to generate H2 through water splitting, the BNT samples provided high production rates (up to 506.70 µmol g-1 h-1). These piezocatalysts also degraded the organic pollutant methylene blue (MB, 20 mg L-1) with high efficiency (up to k = 0.039 min-1), suggesting their potential to treat polluted water. Finally, we found that the piezopotential caused band tilting in the semiconductor and aided charge transfer such that recombination was suppressed and the rate of H2 production increased. The mechanism of piezoelectric catalysis involved oxygen vacancies, the size of the catalyst, and the internal electric field playing important roles to enhance electron-hole separation, which further enhanced the catalysis reactions.

Improved Mass-Transfer Enhances Photo-Driven Dye Degradation and H2 Evolution over a Few-Layer WS2/ZnO Heterostructure.

In this study, we observed the enhanced photocatalytic activity of a few-layer WS2/ZnO (WZ) heterostructure toward dye degradation and H2 production. The few-layer WS2 acted as a co-catalyst that separated photogenerated electron/hole pairs and provided active sites for reactions, leading to the rate of photocatalytic H2 production of WZ being 35% greater than that over the bare ZnO nanoparticles. Moreover, vortex-stirring accelerated the mass-transfer of the reactants, leading to the efficiency of dye photodegradation being 3 times higher than that obtained without high-speed stirring. We observed a similar effect for H2 production, with greater photocatalytic performance arising from the increased mass-transfer of H2 from the catalyst surface to the atmosphere.

In situ TEM observations of void movement in Ag nanowires affecting the electrical properties under biasing.

In this study we investigated the electromigration (EM) of metal electrodes and the effect of stacking faults on the EM in Ag nanowires (NWs). We used the galvanic replacement method to synthesize these NWs by controlling the concentration of silver nitrate. In situ transmission electron microscopy (TEM) revealed the presence of both intrinsic and extrinsic stacking faults in the Ag NWs. We found that planar defects increased the lifetime of the devices with an intrinsic change in the material properties. Our EM measurements involved examinations of the change in electrical resistance (arising from void formation in the NW as a result of electromigration) as well as direct visual observation of the shape (using in situ TEM).

Surfactant-free synthesis of ultralong silver nanowires for durable transparent conducting electrodes.

The present study employed the surfactant-free growth of ultralong (∼50 µm) silver nanowires (AgNWs) with a high aspect ratio (more than 1000) by galvanic replacement. AgNW conducting films were fabricated as electrodes using drop-casting. The AgNW film had 90% transmittance to 550 nm light with a sheet resistance of 232 Ω sq-1. Further, the flexibility test of the transparent flexible AgNW/MoS2 device array indicated that the variation of the current was within 5% when a strain of 0.5% was applied to the device; additionally, the device showed a 13% decrease in current after experiencing 50 000 bending cycles. This study indicated that the ultralong AgNWs synthesized using galvanic replacement have potential for applications as transparent and flexible electrodes.

Alternative surgery for low grade thyroid malignancies.

Traditional surgery for thyroid nodule is usually performed via anatomic localization of the recurrent laryngeal nerve (RLN), inferior thyroid artery and parathyroid glands (PTGs) initially. Due to the RLN constantly lying beneath the thyroid gland and low grade malignancy of well-differentiated thyroid cancer (WDTC), it is not necessary to find the nerve initially and impossible to make too deep resection. From May 1998 to July 2005, 33 patients with WDTC underwent total thyroidectomy along the capsule with or without modified radical neck dissection without identifying the RLN and PTGs initially. The isthmus, capsular vessels and Berry's ligament were cut from above and the RLN could be found lying in the surgical bed. The PTGs could be found when the thyroid was retracted medially and removed. The patients were followed-up until December 2007. The safety of the method, complications and clinical outcomes were evaluated. For the patients with WDTC, only one patient (3%) had transient vocal palsy. Incidental parathyroidectomy was found in six (18%) patients, resulting in two (6%) with temporary and two (6%) with permanent hypocalcemia. Only one 86-year-old woman died of disease recurrence; the other patients remained disease-free. Total thyroidectomy for WDTC without identifying the RLN and PTGs initially is an easy and safe alternative method.