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Tendons are responsible for transmitting mechanical forces from muscles to bones for body locomotion and joint stability. However, tendons are frequently damaged with high mechanical forces. Various methods have been utilized for repairing damaged tendons, including sutures, soft tissue anchors, and biological grafts. However, tendons experience a higher rate of retear post-surgery due to their low cellularity and vascularity. Surgically sutured tendons are vulnerable to reinjury due to their inferior functionality when compared with native tendons. Surgical treatment using biological grafts also has complications such as joint stiffness, re-rupture, and donor-site morbidity. Therefore, current research is focused on developing novel materials that can facilitate the regeneration of tendons with histological and mechanical characteristics similar to those of intact tendons. With respect to the complications in association with the surgical treatment of tendon injuries, electrospinning may be an alternative for tendon tissue engineering. Electrospinning is an effective method for fabrication of polymeric fibers with diameters ranging from nanometers to micrometers. Thus, this method produces nanofibrous membranes with an extremely high surface area-to-volume ratio, which is similar to the extracellular matrix structure, making them suitable candidates for application in tissue engineering. Moreover, it is possible to fabricate nanofibers with specific orientations that are similar to those of the native tendon tissue using an adequate collector. To increase the hydrophilicity of the electrospun nanofibers, natural polymers in addition to synthetic polymers are used concurrently. Therefore, in this study, aligned nanofibers composed of poly-d,l-lactide-co-glycolide (PLGA) and small intestine submucosa (SIS) were fabricated using electrospinning with rotating mandrel. The diameter of aligned PLGA/SIS nanofibers was 568.44 ± 135.594 nm, which closely resembles that of native collagen fibrils. Compared to the results of the control group, the mechanical strength exhibited by the aligned nanofibers was anisotropic in terms of break strain, ultimate tensile strength, and elastic modulus. Elongated cellular behavior was observed in the aligned PLGA/SIS nanofibers using confocal laser scanning microscopy, indicating that the aligned nanofibers were highly effective with regard to tendon tissue engineering. In conclusion, considering its mechanical properties and cellular behavior, aligned PLGA/SIS is a promising candidate for tendon tissue engineering. [ABSTRACT FROM AUTHOR]

The threat of arsenic contamination to public health, particularly in developing countries, has become a serious problem. Millions of people in their daily lives are still highly dependent on groundwater containing high levels of arsenic, which causes excessive exposure to this toxic element, due to the high cost and lack of water-treatment infrastructures. Therefore, a technique for large-scale treatment of water in rural areas to remove arsenic is needed and should be low-cost, be easily customized, and not rely on electrical power. In this study, in an effort to fulfill those requirements, we introduce a three-dimensional (3D), printed water-filtration system for arsenic removal. Three-dimensional printing can provide a compact, customized filtration system that can fulfill the above-mentioned requirements and that can be made from plastic materials, which are abundant. Armed with the versatility of 3D printing, we were able to design the internal surface areas of filters, after which we modified the surfaces of the 3D, printed filters by using iron (III) oxide as an adsorbent for arsenite. We investigated the effects of the controlled surface area on the flow rate and the deposition of the adsorbent, which are directly related to the adsorption of arsenic. We conducted isotherm studies to quantify the adsorption of arsenic on our 3D, printed filtration system. [ABSTRACT FROM AUTHOR]

• PEGBEM-g-PAEMA graft copolymer is synthesized via free-radical polymerization. • The electrolyte maintained its flexible solid film state for EMIMBF 4 content up to 200%. • The solid capacitors exhibited good bending performance without specific encapsulation. • The capacitors with PEGBEM-g-PAEMA exhibited better performance compared with other polymer/EMIMBF 4 cells. We report a solid electrolyte comprising poly(ethylene glycol) behenyl ether methacrylate-g-poly((2-acetoacetoxy)ethyl methacrylate) (PEGBEM-g-PAEMA) graft copolymer for application to solid-state bendable supercapacitors. The graft copolymer was synthesized via free-radical polymerization, and the electrolytes were fabricated by adding 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIMBF 4). Fourier-transform infrared spectroscopy, differential scanning calorimetry, thermogravimetric analysis, X-ray diffraction, small-angle X-ray scattering, and transmission electron microscopy were employed to investigate the chemical, structural, thermal, and morphological properties of the fabricated electrolytes and the compatibility of the two components. The graft copolymer interacted with EMIMBF 4 (the two materials were compatible with each other), and the intruded ionic liquid was well-dispersed through the entire region of the polymer matrix. The fabricated electrolyte maintained its flexible solid film state for EMIMBF 4 content up to 200% without leakage problems. The capacitors were manufactured with porous carbon electrodes and a PEGBEM-g-PAEMA/EMIMBF 4 electrolyte. The capacitors exhibited a capacitance of 55.5F/g, a power density of 900 W/kg, and an energy density of 25 Wh/kg at 1.0 A/g. The capacitors were measured at various bending angles and exhibited good performance without specific encapsulation. According to the results, the newly synthesized PEGBEM-g-PAEMA graft copolymer is a good candidate for a polymer matrix for electrolytes in all-solid-state bendable/flexible supercapacitors. [ABSTRACT FROM AUTHOR]

Programmed, reshaping hydrogel architectures were fabricated from sugar/hydrogel inks via a three-dimensional printing method involving a stimuli-responsive polymer. We developed a new hydrogel ink composed of monomers (acrylamide [AAm]) and N-isopropylacrylamide [NIPAAm]), and sugar (mixture of glucose and sucrose) as a pore-generator, enabling to improve printability by increasing the ink's viscoelastic properties and induce the formation of macropores in the hydrogel architectures. This study demonstrated that creating macropores in such architectures enables rapid responses to stimuli that can facilitate four-dimensional printing. We printed bilayer structures from monomer inks to which we had added sugar, and we exposed them to processes that cross-linked the monomers and leached out the sugar to create macropores. In comparison with a conventional poly(N-isopropylacrylamide) hydrogel, the macroporous hydrogels prepared using polymerization in the presence of a high concentration of sugar showed higher swelling ratios and exhibited much faster response rates to temperature changes. We used rheometry and scanning electron microscopy to characterize the properties of these inks and hydrogels. The results suggest that this method may provide a readily available route to the rapid design and fabrication of shape-morphing hydrogel architectures with potential application in soft robotics, hydrogel actuators, and tissue engineering. [ABSTRACT FROM AUTHOR]

Urban climate influences economic activities and the health and safety of urban residents. Therefore, monitoring temperature in urban areas is important. However, owing to the lack of space for an appropriate observation site, an automatic weather station (AWS) was installed on a building rooftop. The rooftop installation can indicate temperature differences depending on the intensity of strong solar radiation and radiant heat of the building, and wind speed. Therefore, in this study, we aimed to provide observation standards for measuring rooftop temperature according to the optimal rooftop material and observation height. Specifically, an AWS was installed on the rooftop of the Gochang Standard Weather Station (GSWO), Jeollabuk-do Province, to observe the urban climate in South Korea and establish suitable weather standards. Different temperatures, optimum surface materials, and optimum heights for measuring the temperature at the rooftop of GSWO were investigated and compared over 1 year. The temperature recorded after installing a palm mat on the rooftop was more similar to that observed in the grassland. Furthermore, the installation height of the temperature sensor of 2.5–3.0 m for the palm mat and 3.5–4.0 m for concrete was found to be the optimal height for observing temperature at the rooftop. [ABSTRACT FROM AUTHOR]

A 3-year-old dog weighing 8 kg was referred with a disorder of sexual development and persistent urinary incontinence before and after gonadohysterectomy performed at a local animal hospital. Histopathological examination disclosed hypoplasia of the testes, epididymis, pampiniform plexus, and uterus. On ultrasonography, an anomalous structure containing anechoic fluid was identified in the region dorsal to the urinary bladder. An anomalous communication between the proximal urethra and the remnant uterus and vagina was found on retrograde urethrography under fluoroscopy. Reflux of contrast medium into the anomalous structure, suspected to be the uterus and cranial vagina, from the urethra was detected. Computed tomography identified the anomalous structure between the rectum and urethra. The anomalous structure was removed via laparotomy and the urinary incontinence resolved. The diagnosis of XX sex reversal with a developmental anomaly of the genitourinary tract was made on the basis of laparotomy findings and cytogenetic and SRY gene analyses. [ABSTRACT FROM AUTHOR]