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Calcium sulfate, an injectable and biodegradable bone-void filler, is widely used in orthopedic surgery. Based on clinical experience, bone-defect substitutes can also serve as vehicles for the delivery of drugs, for example, antibiotics, to prevent or to treat infections such as osteomyelitis. However, antibiotic additions change the characteristics of calcium sulfate cement. Moreover, high-dose antibiotics may also be toxic to bony tissues. Accordingly, cefazolin at varying weight ratios was added to calcium sulfate samples and characterized in vitro. The results revealed that cefazolin changed the hydration reaction and prolonged the initial setting times of calcium sulfate bone cement. For the crystalline structure identification, X-ray diffractometer revealed that cefazolin additive resulted in the decrease of peak intensity corresponding to calcium sulfate dihydrate which implying incomplete phase conversion of calcium sulfate hemihydrate. In addition, scanning electron microscope inspection exhibited cefazolin changed the morphology and size of the crystals greatly. A relatively higher amount of cefazolin additive caused a faster degradation and a lower compressive strength of calcium sulfate compared with those of uploaded samples. Furthermore, the extract of cefazolin-impregnated calcium sulfate impaired cell viability, and caused the death of osteoblast-like cells. The results of this study revealed that the cefazolin additives prolonged setting time, impaired mechanical strength, accelerated degradation, and caused cytotoxicity of the calcium sulfate bone-void filler. The aforementioned concerns should be considered during intra-operative applications.

This study presents a straightforward strategy that embeds a graphene interlayer between InGaN-based light-emitting diodes (InGaN LEDs) and patterned sapphire substrate (PSS substrate) for substantial improving device performances of wavelength stability and heat dissipation. The InGaN LEDs on the graphene interlayer/PSS substrate (Gr-LED) have lower piezoelectric fields of 1.16 MV/cm than 1.60 MV/cm for InGaN LEDs on the PSS substrate (Ref-LED). The low piezoelectric field diminishes the screen of the polarization field resulting in a stable electroluminescence peak wavelength. At 100 mA driving current, the chip temperature of Gr-LED shows a decrease in around 24.4 °C relative to Ref-LED. The thermal resistances measured in a vacuum environment are 351 and 128 °C/W for Ref-LED and Gr-LED, respectively. The low thermal resistance of Gr-LED is believed to be due to a low misfit dislocation density of the aluminum nitride nucleation layer that increases the vertical direction of heat transport to PSS. This work demonstrates that the graphene/PSS substrate is a promising substrate for high-power InGaN LEDs.

This study investigates that high-quality GaN thin films can be grown on a few-layer graphene (FLG)/sapphire substrate by embedding a hybrid AlN buffer layer (BL). The hybrid AlN BL is constructed by low-temperature AlN nucleation layer (LT-AlN NL) and high-temperature AlN BL grown respectively by sputtering and metal organic chemical vapor deposition (MOCVD). The high density of edge-type threading dislocation (TD) in the GaN sample without hybrid AlN BL provide current leakage paths, resulting in a symmetric and temperature-independent I-V characteristic curve for a Ni-based Schottky contact. The excellent adhesion and uniform coverage of LT-AlN NL on the FLG layer by sputtering can overcome the nucleation issue and prevent the thermal etching effect of graphene during MOCVD epitaxial process. The edge-type TD density and carbon concentration of the GaN thin films grown on the hybrid AlN BL/FLG/sapphire substrate can be reduced significantly, resulting in a lower intensity of blue, green, and orange luminescences on a 17-K photoluminescence spectrum. The Ni-based Schottky contact with a barrier height of 0.69 eV and leakage current density of 4.38 × 10−6 A/cm2 is obtained, which demonstrates that a high-quality GaN thin films can be grown onto an FLG substrate by embedding a hybrid AlN BL.

The application of antifibrotic materials can alleviate epidural fibrosis by restricting excessive fibroblast proliferation and mitigating scar tissue formation. Here, a biodegradable carboxymethyl cellulose (CMC)-Bletilla striata polysaccharide (BSP)-resveratrol (RES) sponge was fabricated to inhibit scar tissue formation post laminectomy surgery. Fibroblasts NIH/3T3, myoblasts C2C12, neural cells PC-12, and Schwann cells RSC96 were used to evaluate the in vitro cytocompatibility. Laminectomies on 10 Sprague–Dawley rats with/without the application of the CMC-BSP-RES sponge were performed. The severity of adhesion between the dura mater and formed scar tissue was qualitatively scored. All cell lines exhibited good viability with no significant difference in cytotoxicity when cultured with variable extractions of the CMC-BSP-RES sponge. S100a4 and P4hb expressions were downregulated in NIH/3T3 cultured in the CMC-BSP-RES sponge, implying that this sponge potentially inhibits fibroblast activity. No post-operative shrinkage or dura mater expansion along the surgical site was detected. The peel-off tests revealed that the tenacity of adhesion de-creased. Histopathological examinations verified that the average number of fibroblasts in the CMC-BSP-RES group considerably decreased. The CMC-BSP-RES sponge is a biocompatible and effective material for alleviating post-operative epidural fibrosis and mitigating fibroblast expression following laminectomy.

The application of antifibrotic materials can alleviate epidural fibrosis by restricting excessive fibroblast proliferation and mitigating scar tissue formation. Here, a biodegradable carboxymethyl cellulose (CMC)-Bletilla striata polysaccharide (BSP)-resveratrol (RES) sponge was fabricated to inhibit scar tissue formation post laminectomy surgery. Fibroblasts NIH/3T3, myoblasts C2C12, neural cells PC-12, and Schwann cells RSC96 were used to evaluate the in vitro cytocompatibility. Laminectomies on 10 Sprague–Dawley rats with/without the application of the CMC-BSP-RES sponge were performed. The severity of adhesion between the dura mater and formed scar tissue was qualitatively scored. All cell lines exhibited good viability with no significant difference in cytotoxicity when cultured with variable extractions of the CMC-BSP-RES sponge. S100a4 and P4hb expressions were downregulated in NIH/3T3 cultured in the CMC-BSP-RES sponge, implying that this sponge potentially inhibits fibroblast activity. No post-operative shrinkage or dura mater expansion along the surgical site was detected. The peel-off tests revealed that the tenacity of adhesion de-creased. Histopathological examinations verified that the average number of fibroblasts in the CMC-BSP-RES group considerably decreased. The CMC-BSP-RES sponge is a biocompatible and effective material for alleviating post-operative epidural fibrosis and mitigating fibroblast expression following laminectomy.

Oxidative stress and later-induced chronic inflammation have been reported to play an important role on the progression of sarcopenia. Current treatments for sarcopenia are mainly administered to patients whom sarcopenia already developed. However, there has been no promising results shown in therapy. Therefore, the development of therapeutic and preventive strategies against sarcopenia would be necessary. Curcumin is a traditional medicine that possesses anti-inflammatory and antioxidative properties. In the present study, hydroxyapatite was subjected to hydrophobic surface modifications for curcumin loading (Cur-SHAP). It was, subsequently, utilized for delivery to the patient’s body via intramuscular injection in order to achieve constant release for more than 2 weeks, preventing the progression of the sarcopenia or even leading to recovery from the early stage of the illness. According to the results of WST-1, LIVE/DEAD, DCFDA, and gene expression assays, Cur-SHAP exhibited good biocompatibility and showed great antioxidant/anti-inflammatory effects through the endocytic pathway. The results of the animal studies showed that the muscle endurance, grip strength, and fat/lean mass ratio were all improved in Cur-SHAP-treated rats from LPS-induced sarcopenia. In summary, we successfully synthesized hydrophobic surface modification hydroxyapatite for curcumin loading (Cur-SHAP) and drug delivery via the IM route. The LPS-induced sarcopenia rats were able to recover from disease after the Cur-SHAP treatment.

Carbon-doped GaN (GaN:C) Schottky diodes are prepared by controlling the destruction status of the graphene interlayer (GI) on the substrate. The GI without a sputtered AlN capping layer (CL) was destroyed because of ammonia precursor etching behavior in a high-temperature epitaxy. The damaged GI, like nanographite as a solid-state carbon doping source, incorporated the epitaxial growth of the GaN layer. The secondary ion mass spectroscopy depth profile indicated that the carbon content in the GaN layer can be tuned further by optimizing the sputtering temperature of AlN CL because of the better capping ability of high crystalline quality AlN CL on GI being achieved at higher temperature. The edge-type threading dislocation density and carbon concentration of the GaN:C layer with an embedded 550 °C-grown AlN CL on a GI substrate can be significantly reduced to 2.28 × 10

This study grew nitrogen doped ultrananocrystalline diamond (N-UNCD) conductive layer on InGaN-based light emitting diodes (LEDs) using the concave nanopattern (CNP) enhanced nucleation. The low nucleation density of the N-UNCD on bare LEDs (Br-LED) resulted in an island morphology. The nucleation density of the N-UNCD increased significantly from 1.8 × 108 cm−2 for Br-LED to 3.6 × 109 cm−2 for LEDs with a CNP density of 6.1 × 109 cm−2 (CNP-LED). The N-UNCD preferred to nucleate inside the CNP during the initial growth stage. The N-UNCD islands then merged and grew laterally to form a continuous thin film within a thickness of 300 nm. The N-UNCD/CNP-LED exhibited a stable electroluminescence peak wavelength of ~447.1 nm in the injection current range of 10–100 mA. The decrease in the compressive stress due to removing the p-GaN layer (i.e. the CNP structure) resulted in a quantum confined Stark effect (QCSE) mitigation in the multi-quantum wells (MQWs). In addition, the lower turn on voltage caused a lower electric field in the MQWs and diminished the screen of the QCSE. The N-UNCD prepared by the proposed nucleation technique demonstrated a promising conductive layer for InGaN-based LEDs.

A hybrid patterned sapphire substrate (hybrid-PSS) was prepared using an anodic aluminum oxide etching mask to transfer nanopatterns onto a conventional patterned sapphire substrate with microscale patterns (bare-PSS). The threading dislocation (TD) suppression of light-emitting diodes (LEDs) grown on a hybrid-PSS (HP-LED) exhibits a smaller reverse leakage current compared with that of LEDs grown on a bare-PSS (BP-LED). The strain-free GaN buffer layer and fully strained InGaN active layer were evidenced by cross-sectional Raman spectra and reciprocal space mapping of the X-ray diffraction intensity for both samples. The calculated piezoelectric fields for both samples are close, implying that the quantum-confined Stark effect was not a dominant mechanism influencing the electroluminescence (EL) peak wavelength under a high injection current. The bandgap shrinkage effect of the InGaN well layer was considered to explain the large red-shifted EL peak wavelength under high injection currents. The estimated LED chip temperatures rise from room temperature to 150 °C and 75 °C for BP-LED and HP-LED, respectively, at a 600-mA injection current. This smaller temperature rise of the LED chip is attributed to the increased contact area between the sapphire and the LED structural layer because of the embedded nanopattern. Although the chip generates more heat at high injection currents, the accumulated heat can be removed to outside the chip effectively. The high diffuse reflection (DR) rate of hybrid-PSS increases the escape probability of photons, resulting in an increase in the viewing angle of the LEDs from 130° to 145°. The efficiency droop was reduced from 46% to 35%, effects which can be attributed to the elimination of TDs and strain relaxation by embedded nanopatterns. In addition, the light output power of HP-LED at 360-mA injection currents exhibits a ∼ 22.3% enhancement, demonstrating that hybrid-PSSs are beneficial to apply in high-power LEDs.

It has been reported in many literatures that different kinds of bone graft augmentations have been applied in the treatment of distal radial fractures with favorable results. The authors applied calcium sulfate cement in the treatment of distal radial fractures and evaluated the radiological outcomes of 33 patients. The radiological changes of cement statuses, implants, and radiological parameter of distal radius were analyzed. After closed reduction of the displacement, fractures were fixed by Kirschner pins and stabilized by percutaneous injection of premixed calcium sulfate bone cement. Periodic X-ray evaluations were obtained at immediate post-operation and at every month. A total of 28 patients completed the follow-up and the cement extravasations into wrist joint or into soft tissues had been seen in almost every patient. The gradual settling and losses of radial height, radial inclination angle, and volar tilting angles were significant even after removal of Kirschner pins after 8 weeks. Gradual absorptions of cured cement block inside and outside distal radial cortices were observed in every case and complete absorptions of intraosseous cements after 8 weeks happened in 53.6% (15/28) of patients. The extravasated cements took longer time to fade away. The radiological results of current study revealed negative results of calcium sulfate applied in the treatment of distal radial fracture in terms of reduction parameters and cement block longevity.