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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]

Enhancers cause a high level of transcription and activation of chromatin structure at target genes. Hyperacetylation of histones H3 and H4, a mark of active chromatin, is established broadly across target loci by enhancers that function over long distances. In the present study, we studied the role of an enhancer in methylation of various lysine residues on H3 by comparing a model gene locus having an active enhancer with one in which the enhancer has been inactivated within the context of minichromosomes. The intact enhancer affected histone methylation at K4, K9 and K36 in distinct ways depending on the methylation level and the location in the locus. All three lysine residues were highly tri-methylated in the coding region of the gene linked to the active enhancer but not the inactive enhancer. However di-methylation of K9 and K36 was not affected by the enhancer. The enhancer region itself was marked by mono-methylation at K4 and K9, distinguishing it from the methyl marks in the gene coding region. These results indicate that an enhancer has roles in establishing active histone methylation patterns linked with gene transcription rather than removing methylation linked with gene inactivation. [ABSTRACT FROM AUTHOR]

RNase P, a tRNA processing enzyme, contains both RNA and protein subunits. M1 RNA, the catalytic RNA subunit of RNase P from Escherichia coil, recognizes its target RNA substrate mainly on the basis of its structure and cleaves a double stranded RNA helix at the 5' end that resembles the acceptor stem and T-stem structure of its natural tRNA substrate. Accordingly, a guide sequence (GS) can be covalently attached to the M1 RNA to generate a sequence specific ribozyme, M1GS RNA. M1GS ribozyme can target any mRNA sequence of choice that is complementary to its guide sequence. Recent studies have shown that M1GS ribozymes efficiently cleave the mRNAs of herpes simplex virus 1 and human cytomegalovirus, and the BCR-ABL oncogenic mRNA in vitro and effectively reduce the expression of these mRNAs in cultured cells. Moreover, an in vitro selection scheme has been developed to select for M1 GS ribozyme variants with more efficient catalytic activity in cleaving mRNAs. When expressed in cultured cells, these selected ribozymes also show an enhance ability to inhibit viral gene expression and growth. These recent results demonstrate the feasibility of developing the M1GS ribozyme-based technology as a promising gene targeting approach for basic research and clinical therapeutic application. [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]

Ribonuclease P (RNase P) complexed with external guide sequence (EGS) represents a nucleic acid-based gene interference approach to knock-down gene expression. Unlike other strategies, such as antisense oligonucleotides, ribozymes, and RNA interference, the RNase P-based technology is unique because a custom-designed EGS molecule can bind to any complementary mRNA sequence and recruit intracellular RNase P for specific degradation of the target mRNA. In this study, we demonstrate that the RNase P-based strategy is effective in blocking gene expression and growth of Kaposi's sarcoma (KS)-associated herpesvirus (KSHV), the causative agent of the leading AIDS-associated neoplasms, such as KS and primary-effusion lymphoma. We constructed 2'-O-methyl-modifiecl EGS molecules that target the mRNA encoding KSHV immediate-early transcription activator Rta, and we administered them directly to human primary-effusion lymphoma cells infected with KSHV. A reduction of 90% in Rta expression and a reduction of &ap;150-fold in viral growth were observed in cells treated with a functional EGS. In contrast a reduction of <10% in the RU expression and viral growth was found in cells that were either not treated with an EGS or that were treated with a disabled EGS containing mutations that preclude recognition by RNase P. Our study provides direct evidence that EGSs are highly effective in inhibiting KSHV gene expression and growth. Exogenous administration of chemically modified EGSs in inducing RNase P-mediated cleavage represent an approach for inhibiting specific gene expression and for treating human diseases, including KSHV- associated tumors. [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]

Engineered RNase P ribozymes are promising genetargeting agents that can be used in both basic research and clinical applications. We have previously selected ribozyme variants for their activity in cleaving an mRNA substrate from a pool of ribozymes containing randomized sequences. In this study, one of the variants was used to target the mRNA encoding thymidine kinase (TK) of herpes simplex virus 1 (HSV-1). The variant exhibited enhanced cleavage and substrate binding and was at least 30 times more efficient in cleaving TK mRNA in vitro than the ribozyme derived from the wild type sequence. Our results provide the first direct evidence to suggest that a point mutation at nucleotide 95 of RNase P catalytic RNA from Escherichia coli (G95 → U95) increases the rate of cleavage, whereas another mutation at nucleotide 200 (A200 → C200) enhances substrate binding of the ribozyme. A reduction of about 99% in TK expression was observed in cells expressing the variant, whereas a 70% reduction was found in cells expressing the ribozyme derived from the wild type sequence. Thus, the RNase P ribozyme variant is highly effective in inhibiting HSV-1 gene expression. Our study demonstrates that ribozyme variants increase their cleavage activity and efficacy in blocking gene expression in cells through enhanced substrate binding and rate of cleavage. These results also provide insights into the mechanism of how RNase P ribozymes efficiently cleave an mRNA substrate and, furthermore, facilitate the development of highly active RNase P ribozymes for gene-targeting applications. [ABSTRACT FROM AUTHOR]