The distance of insertion points from wound margins in interrupted and vertical mattress sutures influences the tensile load capacity: An in vitro experimental study.

AIM: To determine the tensile load capacity (TLC) and the tearing characteristics for interrupted and vertical mattress sutures with different insertion points from the wound margin, and the effect of the bite size when using vertical mattress sutures. MATERIALS AND METHODS: A total of 120 gingiva and lining mucosa samples obtained from pig jaws were divided into groups according to the suturing technique (interrupted and vertical mattress sutures), distance of the insertion points from the wound margin (margin, 1, 3, and 5 mm) and bite size (1, 3, and 5 mm). The TLC of the suture and the tearing characteristics were evaluated using a tensile tester device. RESULTS: The TLC was significantly higher for vertical mattress sutures than for interrupted sutures regardless of the distance of the insertion points from the wound margin (intergroup p < .001). This distance significantly influenced the TLC for vertical mattress sutures (p < .05) but not for interrupted sutures (p > .05). Testing the tearing characteristics revealed that no tissue tearing occurred in groups when the insertion points were more than 3 mm from the wound margin. CONCLUSION: The TLC is higher for vertical mattress sutures than for interrupted sutures, and it increases when the insertion points are farther from the wound margin.

Alveolar ridge regeneration in two-wall-damaged extraction sockets of an in vivo experimental model.

AIM: To determine the healing outcome following grafting with deproteinized porcine bone mineral (DPBM) with or without collagen membrane coverage in two-wall (both buccal and lingual)-damaged extraction sockets. MATERIALS AND METHODS: Distal roots of three mandibular premolars in six beagle dogs were extracted, and the whole buccal and lingual bony walls were surgically removed. Three treatment protocols were then applied according to the following group allocation: no graft (None), grafting DPBM (BG), and grafting DPBM with coverage by a collagen membrane (BG + M). Two observational periods (2 and 8 weeks) were used with the split-mouth design, and quantitative and qualitative analyses were performed by microcomputed tomography and histology. RESULTS: The dimensions of the alveolar ridge at both grafted sites (BG and BG + M) remained similar to those of the pristine ridge in the histologic and radiographic analyses, whereas the ungrafted sites (None) collapsed both vertically and horizontally. Both grafting protocols produced substantial bony regeneration, but the addition of a covering membrane enhanced the proportion of mineralized tissue within the augmented area, and the BG + M group also showed a significantly larger area of regenerated ridge than the None group (p < .05). CONCLUSIONS: Bone grafting with collagen membrane can maintain the alveolar ridge dimensions with substantial bone regeneration in a two-wall-damaged extraction socket.

Epitaxial Growth of Thin Ferroelectric Polymer Films on Graphene Layer for Fully Transparent and Flexible Nonvolatile Memory.

Enhancing the device performance of organic memory devices while providing high optical transparency and mechanical flexibility requires an optimized combination of functional materials and smart device architecture design. However, it remains a great challenge to realize fully functional transparent and mechanically durable nonvolatile memory because of the limitations of conventional rigid, opaque metal electrodes. Here, we demonstrate ferroelectric nonvolatile memory devices that use graphene electrodes as the epitaxial growth substrate for crystalline poly(vinylidene fluoride-trifluoroethylene) (PVDF-TrFE) polymer. The strong crystallographic interaction between PVDF-TrFE and graphene results in the orientation of the crystals with distinct symmetry, which is favorable for polarization switching upon the electric field. The epitaxial growth of PVDF-TrFE on a graphene layer thus provides excellent ferroelectric performance with high remnant polarization in metal/ferroelectric polymer/metal devices. Furthermore, a fully transparent and flexible array of ferroelectric field effect transistors was successfully realized by adopting transparent poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] semiconducting polymer.

Synthesis and characterization of an anthracene-based low band gap polymer for photovoltaic devices.

We have synthesized an anthracene-based conjugated polymer, poly[(9,10-bis(oct-1-ynyl)anthracene)-alt-(5,6-bis(octyloxy)-4,7-bis(thiophen-2-yl)benzo-[c][1,2,5]-thiadiazole)] (PANTBT), for application in organic photovoltaic devices. It exhibited a number average molecular weight of 14,300 g/mol and was fairly soluble in chlorinated organic solvents due to flexible octynyl- and octyloxy side chains on the anthracene and benzothiadiazole moieties. PANTBT showed absorption covering 300-660 nm. Through the bond alternation between the electron-sufficient anthracene (and thiophene) and electron-deficient benzothiadiazole units, a band gap of PANTBT was decreased to 1.89 eV, showing a deep HOMO level of -5.31 eV. As a result, PANTBT exhibited promising photovoltaic properties with a PCE value of 1.90% (VOC = 0.77 V, JSC = -6.50 mA/cm2, FF = 0.38) upon blending with PC71, BM under AM 1.5G.

Unveiling the Role of Side Chain for Improving Nonvolatile Characteristics of Conjugated Polymers-Based Artificial Synapse.

Interest has grown in services that consume a significant amount of energy, such as large language models (LLMs), and research is being conducted worldwide on synaptic devices for neuromorphic hardware. However, various complex processes are problematic for the implementation of synaptic properties. Here, synaptic characteristics are implemented through a novel method, namely side chain control of conjugated polymers. The developed devices exhibit the characteristics of the biological brain, especially spike-timing-dependent plasticity (STDP), high-pass filtering, and long-term potentiation/depression (LTP/D). Moreover, the fabricated synaptic devices show enhanced nonvolatile characteristics, such as long retention time (≈102 s), high ratio of Gmax/Gmin, high linearity, and reliable cyclic endurance (≈103 pulses). This study presents a new pathway for next-generation neuromorphic computing by modulating conjugated polymers with side chain control, thereby achieving high-performance synaptic properties.

Ratiometric fluorescent ion detection in water with high sensitivity via aggregation-mediated fluorescence resonance energy transfer using a conjugated polyelectrolyte as an optical platform.

A cationic conjugated polyelectrolyte was designed and synthesized based on poly(fluorene-co-phenylene) containing 5 mol% benzothiadiazole (BT) as a low energy trap and 15-crown-5 as a recognizing group for potassium ions. A potassium ion can form a sandwich-type 2:1 Lewis acid-based complex with 15-crown-5, to cause the intermolecular aggregation of polymers. This facilitates inter-chain fluorescence resonance energy transfer (FRET) to a low-energy BT segment, resulting in fluorescent signal amplification, even at dilute analyte concentrations. Highly sensitive and selective detection of K(+) ions was demonstrated in water. The linear response of ratiometric fluorescent signal as a function of [K(+) ] allows K(+) quantification in a range of nanomolar concentrations with a detection limit of ≈0.7 × 10(-9) M.

Superhydrophobic polypropylene sorbent derived from discarded face masks: A highly efficient adsorbent for oil spill sorbent.

Globally, an estimated 130 billion face masks are used and disposed of every month. Thus, recycling or upcycling discarded face masks has attracted significant attention due to economic benefits and environmental concerns. To reduce the amount of used face masks going to waste, this study features a superhydrophobic face mask prepared by simple chemical modification with environmentally preferable alkane solvents (n-hexane, n-heptane, and n-decane), that is effective as a sorbent for oil spill cleanup. All alkanes examined increased the surface roughness of the face masks and improved face mask hydrophobicity. The heptane treated face mask (at 90 °C for 1 h), can adsorbed Arabian light crude oil up to 21 times of their weight on the water surface. In addition, chloroform, toluene, gasoline, and diesel were adsorbed 18, 13, 8 and 16 times, respectively. More importantly, heptane has a high recycling efficiency as a treatment solvent and is reusable for at least 10 cycles of mask surface treatment. Consequently, this inexpensive and easily fabricated material is a promising development in waste face mask (WFM) upcycling.

Comparative analysis of therapeutic effects between medium cut-off and high flux dialyzers using metabolomics and proteomics: exploratory, prospective study in hemodialysis.

In this single-center prospective study of 20 patients receiving maintenance hemodialysis (HD), we compared the therapeutic effects of medium cut-off (MCO) and high flux (HF) dialyzers using metabolomics and proteomics. A consecutive dialyzer membrane was used for 15-week study periods: 1st HF dialyzer, MCO dialyzer, 2nd HF dialyzer, for 5 weeks respectively. 1H-nuclear magnetic resonance was used to identify the metabolites and liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis was used to identify proteins. To compare the effects of the HF and MCO dialyzers, orthogonal projection to latent structure discriminant analysis (OPLS-DA) was performed. OPLS-DA showed that metabolite characteristics could be significantly classified by 1st HF and MCO dialyzers. The Pre-HD metabolites with variable importance in projection scores ≥ 1.0 in both 1st HF versus MCO and MCO versus 2nd HF were succinate, glutamate, and histidine. The pre-HD levels of succinate and histidine were significantly lower, while those of glutamate were significantly higher in MCO period than in the HF period. OPLS-DA of the proteome also substantially separated 1st HF and MCO periods. Plasma pre-HD levels of fibronectin 1 were significantly higher, and those of complement component 4B and retinol-binding protein 4 were significantly lower in MCO than in the 1st HF period. Interestingly, as per Ingenuity Pathway Analysis, an increase in epithelial cell proliferation and a decrease in endothelial cell apoptosis occurred during the MCO period. Overall, our results suggest that the use of MCO dialyzers results in characteristic metabolomics and proteomics profiles during HD compared with HF dialyzers, which might be related to oxidative stress, insulin resistance, complement-coagulation axis, inflammation, and nutrition.

Dose evaluation of selective collimation effect in cephalography by measurement and Monte Carlo simulation.

Recently, simulations based on the Monte Carlo code have been increasingly applied for physics phenomena, patient dose and quality assurance of radiation systems. The objective of this study was to use Monte Carlo simulation and measurement to verify dose and dose reduction in cephalography. The collimator was constructed with 3-mm thick lead plate, and attached to the tube head to remove regions of disinterest in the radiation field. A digital phantom patient was constructed to evaluate patient dose. In addition, detectors of pixel size 1×1 cm² and 0.1×0.1 cm² were constructed to check collimator location. The effective dose according to International Commission on Radiological Protection 103 was calculated with and without collimation. The effective doses for simulation with and without collimation were 5.09 and 11.32 µSv, respectively. The results of the calculated effective dose show 61.7 % reduction of field area and 55 % of effective dose. The Monte Carlo simulation is a good evaluation tool for patient dose.

The characteristics of dental X-ray fluoroscopic equipment 'DreamRay 60F'.

This study examined the characteristics of the dental X-ray fluoroscopic equipment, 'DreamRay 60F', which was recently developed in Korea. The output linearity, output reproducibility, half-value layer (HVL), leakage radiation and scattered radiation were measured using an ionisation chamber. The surface dose equivalent rate and estimated dose equivalent of the operator were also calculated. The output linearity was 0.0015-0.0175 and the coefficient of variation for the output reproducibility was 0.0013-0.0074. The experimental HVL was 2.1 mm Al, and the leakage dose rate at 100 cm from the X-ray focus ranged from 2.70 to 19.66 microGy h (-1) depending on the direction. The scattered radiation doses differed significantly (1.7-16.8 times) depending on the distance and direction. If an operator is exposed for 10 min per procedure, 5 procedures a day at 5 days a week, he/she sitting at a 90 degrees direction will receive an annual dose equivalent of 13.0 mSv (at 30 cm) and 63.7 mSv (at 50 cm) in the trunk and face surface, respectively.