Effective Spiral Laser Path for Minimizing Local Heating and Anisotropic Microstructures in Powder Bed Fusion Additive Manufacturing.

Heat accumulation due to repetitive simple laser processing paths during building up a three-dimensional structure is a well-known issue that needs to be settled to reduce the excessively high residual stress and thermal deformation in a powder bed fusion (PBF) additive manufacturing process. Because of the dependency of laser path on the thermal dispersion, it is essential to analyze the heat accumulation phenomenon during laser processing. A computational fluid dynamics (CFD) analysis based on the volume of fraction method is used to optimize the laser path for minimizing the local heating up in the PBF process.

Crack Control in Additive Manufacturing by Leveraging Process Parameters and Lattice Design.

This study investigates the design of additive manufacturing for controlled crack propagation using process parameters and lattice structures. We examine two lattice types-octet-truss (OT) and diamond (DM)-fabricated via powder bed fusion with Ti-6Al-4V. Lattice structures are designed with varying densities (10%, 30%, and 50%) and process using two different laser energies.

Quick-Delivery Mold Fabricated via Stereolithography to Enhance Manufacturing Efficiency.

The ever-growing demand for reducing costs and decreasing the time to market in today's plastics industry makes rapid tooling and rapid prototyping highly researched areas. Stereolithography (SLA)-manufactured injection mold inserts make it possible to produce prototype parts rapidly and cost-effectively. To utilize SLA in the injection molding industry, two steps have to be considered.

Effects of Growth Hormone-Releasing Hormone (GHRH) Plasmid Treatment on the Reproductive Productivity of Sows in Primiparous and Multiparous Sow Breeds.

The effect of growth hormone-releasing hormone (GHRH) plasmid treatment on sow reproductive performance was examined. Forty pregnant sows (three-way crossbreed: Landrace × Yorkshire × Duroc) at 85 days of gestation were included in the study and consisted of twenty primiparous and twenty multiparous sows (third parity). Sows were randomly assigned to the control and treatment groups.

Annealing Heat Treatment for Homogenizing the Microstructure and Mechanical Properties of Electron-Beam-Welded Thick Plate of Ti-6Al-4V Alloy.

In the application of Ti-6Al-4V to aerospace structural components, when welding thick plates similar of the thickness of the components, microstructure and hardness gradients emerge between the base material (BM) and the joint. This leads to the issue of significant stress concentration in the BM under tensile stress. To address this problem through post-welding heat treatment, this study conducted heat treatments at temperatures both below (mill annealing, MA) and above the beta-transus temperature (beta annealing, BA) on electron-beam weldments of 18 mm thickness Ti-6Al-4V plates.

Highly Enantioselective 6π Photoelectrocyclizations Engineered by Hydrogen Bonding.

Photochemical electrocyclization reactions are valued for both their ability to produce structurally complex molecules and their central role in elucidating fundamental mechanistic principles of photochemistry. We present herein a highly enantioselective 6π photoelectrocyclization catalyzed by a chiral Ir(III) photosensitizer. This transformation was successfully realized by engineering a strong hydrogen-bonding interaction between a pyrazole moiety on the catalyst and a basic imidazolyl ketone on the substrate.

Enhanced Energy Absorption of Additive-Manufactured Ti-6Al-4V Parts via Hybrid Lattice Structures.

In this study, we present the energy absorption capabilities achieved through the application of hybrid lattice structures, emphasizing their potential across various industrial sectors. Utilizing Ti-6Al-4V and powder bed fusion (PBF) techniques, we fabricated distinct octet truss, diamond, and diagonal lattice structures, tailoring each to specific densities such as 10, 30, and 50%. Furthermore, through the innovative layering of diverse lattice types, we introduced hybrid lattice structures that effectively overcome the inherent energy absorption limitations of single-lattice structures.

APP-C31: An Intracellular Promoter of Both Metal-Free and Metal-Bound Amyloid-β Aggregation and Toxicity in Alzheimer's Disease.

Intracellular C-terminal cleavage of the amyloid precursor protein (APP) is elevated in the brains of Alzheimer's disease (AD) patients and produces a peptide labeled APP-C31 that is suspected to be involved in the pathology of AD. But details about the role of APP-C31 in the development of the disease are not known. Here, this work reports that APP-C31 directly interacts with the N-terminal and self-recognition regions of amyloid-β (Aβ ) to form transient adducts, which facilitates the aggregation of both metal-free and metal-bound Aβ peptides and aggravates their toxicity.

Mucoadhesive chitosan microcapsules for controlled gastrointestinal delivery and oral bioavailability enhancement of low molecular weight peptides.

A bioactive compound, collagen peptide (CP), is widely used for biological activities such as anti-photoaging and antioxidant effects, with increased oral bioavailability because of its low molecular weight and high hydrophilicity. However, controlling release time and increasing retention time in the digestive tract for a more convenient oral administration is still a challenge. We developed CP-loaded chitosan (CS) microcapsules via strong and rapid ionic gelation using a highly negative phytic acid (PA) crosslinker.

Color-Tuning Mechanism of the Lit Form of Orange Carotenoid Protein.

Orange carotenoid protein (OCP) of photosynthetic cyanobacteria binds to ketocarotenoids noncovalently and absorbs excess light to protect the host organism from light-induced oxidative damage. Herein, we found that mutating valine 40 in the α3 helix of sp. PCC 7513 (GOCP1) resulted in blue- or red-shifts of 6-20 nm in the absorption maxima of the lit forms.

Hyaluronic acid hydrolysis using vacuum ultraviolet TiO photocatalysis combined with an oxygen nanobubble system.

Advanced technologies for producing high-quality low molecular weight hyaluronic acid (LMW-HA) are required from the perspective of cost-efficiency and biosafety. Here, we report a new LMW-HA production system from high molecular weight HA (HMW-HA) using vacuum ultraviolet TiO photocatalysis with an oxygen nanobubble system (VUV-TP-NB). The VUV-TP-NB treatment for 3 h resulted in a satisfactory LMW-HA (approximately 50 kDa measured by GPC) yield with a low endotoxin level.

Estimating implicit discount rate for energy efficiency investment using the contingent valuation method: a case study in South Korea.

This study measures the implicit discount rate (IDR) for energy efficiency investment at the household level. Our pioneering attempt to use the contingent valuation method suggests fresh insights into relieving the possible problems induced when the IDR is estimated using multiple price list and open-ended questions. Using the survey data from 2392 respondents in South Korea, we measured the IDR for appliances with high energy efficiency.

Engineering Silk Protein to Modulate Polymorphic Transitions for Green Lithography Resists.

Silk protein is being increasingly introduced as a prospective material for biomedical devices. However, a limited locus to intervene in nature-oriented silk protein makes it challenging to implement on-demand functions to silk. Here, we report how polymorphic transitions are related with molecular structures of artificially synthesized silk protein and design principles to construct a green-lithographic and high-performative protein resist.

Estimating Quantum Mutual Information of Continuous-Variable Quantum States by Measuring Purity and Covariance Matrix.

We derive accessible upper and lower bounds for continuous-variable (CV) quantum states on quantum mutual information. The derivations are based on the observation that some functions of purities bound the difference between quantum mutual information of a quantum state and its Gaussian reference. The bounds are efficiently obtainable by measuring purities and the covariance matrix without multimode quantum state reconstruction.

Variance-aware weight quantization of multi-level resistive switching devices based on Pt/LaAlO/SrTiO heterostructures.

Resistive switching devices have been regarded as a promising candidate of multi-bit memristors for synaptic applications. The key functionality of the memristors is to realize multiple non-volatile conductance states with high precision. However, the variation of device conductance inevitably causes the state-overlap issue, limiting the number of available states.

Imaging Spatial Distribution of Photogenerated Carriers in Monolayer MoS with Kelvin Probe Force Microscopy.

The spatial distribution of photogenerated carriers in atomically thin MoS flakes is investigated by measuring surface potential changes under light illumination using Kelvin probe force microscopy (KPFM). It is demonstrated that the vertical redistribution of photogenerated carriers, which is responsible for photocurrent generation in MoS photodetectors, can be imaged as surface potential changes with KPFM. The polarity of surface potential changes points to the trapping of photogenerated holes at the interface between MoS and the substrate as a major mechanism for the photoresponse in monolayer MoS.

Visible-Light-Induced Organophotocatalytic Difunctionallization: Open-Air Hydroxysulfurization of Aryl Alkenes with Aryl Thiols.

Herein, we report a regioselective visible-light-induced organophotoredox catalytic difunctionalization method to prepare β-hydroxysulfides using aryl alkenes and aryl thiols as substrates. The reaction provides a wide substrate scope of aryl alkenes (from simple styrene to complex bioactive compounds) and aryl thiols (from diverse heteroaromatic thiols to nonheteroaromatic thiols) (total 45 examples, up to 88% yield). Based on the combined experimental and computational studies, we demonstrate that generated hydroperoxyl radicals from O in air react with benzylic radicals, which restrains the reaction between benzylic radicals and the acidic form of thiols in a classical thiol-ene radical reaction.

Estimating Non-Gaussianity of a Quantum State by Measuring Orthogonal Quadratures.

We derive the lower bounds for a non-Gaussianity measure based on quantum relative entropy (QRE). Our approach draws on the observation that the QRE-based non-Gaussianity measure of a single-mode quantum state is lower bounded by a function of the negentropies for quadrature distributions with maximum and minimum variances. We demonstrate that the lower bound can outperform the previously proposed bound by the negentropy of a quadrature distribution.

Top-emitting 940-nm thin-film VCSELs transferred onto aluminum heatsinks.

Thin-film vertical cavity surface emitting lasers (VCSELs) mounted onto heatsinks open up the way toward low-power consumption and high-power operation, enabling them to be widely used for energy saving high-speed optical data communication and three-dimensional sensor applications. There are two conventional VCSEL polarity structures: p-on-n and n-on-p polarity. The former is more preferably used owing to the reduced series resistance of n-type bottom distributed Bragg reflection (DBR) as well as the lower defect densities of n-type GaAs substrates.

Controllable, Self-Powered, and High-Performance Short-Wavelength Infrared Photodetector Driven by Coupled Flexoelectricity and Strain Effect.

Mechanical deformation-induced strain gradients and coupled spontaneous electric polarization field in centrosymmetric materials, known as the flexoelectric effect, can generate ubiquitous mechanoelectrical functionalities, like the flexo-photovoltaic effect. Concurrently, nano/micrometer-scale inhomogeneous strain reengineers the electronic arrangements and in turn, could alter the fundamental limits of optoelectronic performance. Here, the flexoelectric effect-driven self-powered giant short-wavelength infrared (λ ≤ 1800 nm) photoresponse from centrosymmetric bulk silicon, indeed far beyond the fundamental bandgap (λ = 1100 nm) is demonstrated.

An Artificial Mechano-Nociceptor with Mott Transition.

Intelligent touch sensing is now becoming an essential part of various human-machine interactions and communication, including in touchpads, autonomous vehicles, and smart robotics. Usually, sensing of physical objects is enabled by applied force/pressure sensors; however, reported conventional tactile devices are not able to differentiate sharp and blunt objects, although sharp objects can cause unavoidable damage. Therefore, it is central issue to implement electronic devices that can classify sense of touch and simultaneously generate pain signals to avoid further potential damage from sharp objects.

Optimization of the Projection Microstereolithography Process for a Photocurable Biomass-Based Resin.

Biomass materials, an important source of chemical feedstocks, could replace fossil fuels as a resource in the future. The chemical feedstocks from biomass materials are used in many medical and pharmaceutical products and in fuels, chemicals, and functional materials. Biomass materials are expected to be used in biomedical engineering fields, especially due to their low biotoxicity.

Transcranial Doppler study in acute spontaneous intracerebral hemorrhage: The role of pulsatility index.

Objective: Pulsatility index (PI) is a parameter calculated by transcranial Doppler sonography (TCD), which is commonly used for patients with subarachnoid hemorrhage or ischemic stroke. However, we performed a retrospective analysis of patients with acute spontaneous intracerebral hemorrhage (ICH) to assess the function of TCD, particularly the PI.

Methods: This study involved a total of 46 patients with acute ICH who received treatment at a single center between May 2013 and December 2014.

Light intensity dependence of organic solar cell operation and dominance switching between Shockley-Read-Hall and bimolecular recombination losses.

We investigated the variation of current density-voltage (J-V) characteristics of an organic solar cell (OSC) in the dark and at 9 different light intensities ranging from 0.01 to 1 sun of the AM1.5G spectrum.