Nihon University

The effect of a feldspathic porcelain coating applied before or after zirconia sintering on the shear bond strength between a resin luting agent and zirconia was evaluated. Pre-sintered and fully sintered zirconia specimens were coated with feldspathic porcelain and divided into three surface treatment groups: no treatment, airborne-particle abrasion, and hydrofluoric acid etching. The specimens were bonded using a dual-polymerizing resin luting agent and subjected to 0 or 5,000 thermocycles. The shear bond strength was measured. The fracture modes were analyzed microscopically. The surface morphology and composition were examined by scanning electron microscopy (SEM) and X-ray diffraction. Before thermocycling, both airborne-particle abrasion and hydrofluoric acid etching significantly increased the bond strength compared with no treatment. After thermocycling, airborne-particle abrasion maintained the highest bond durability, while hydrofluoric acid etching showed a marked decrease. SEM revealed that airborne-particle abrasion produced a rough surface favorable for micromechanical retention, whereas hydrofluoric acid etching resulted in smoother morphology. Airborne-particle abrasion effectively enhanced and preserved the bond strength between the resin luting agent and feldspathic porcelain-coated zirconia, regardless of the coating sequence. Hydrofluoric acid etching was ineffective after thermocycling, likely due to surface precipitation that occurred during firing.

This study evaluated the effects of atmospheric nitrogen plasma on shear load resistance (SLR), penetration distance, and penetration area of adhesives used in the partial repair of bonded lingual retainers. Bonding gaps of 50, 100, and 150 μm were prepared between bovine enamel and composite resin, followed by plasma irradiation, and the surface free energy of the gaps was assessed. After adhesive application to the gap followed by curing the adhesive, the SLR, adhesive penetration distance, and penetration area of the treated surfaces were measured. In addition, these measurements were statistically compared with those of the untreated group. At 150 μm, plasma treatment significantly increased SLR, particularly with the 4-META/MMA-TBB resin adhesive. For all gap thicknesses, plasma treatment significantly enhanced the penetration distance and penetration area of the adhesives. These results suggest that plasma irradiation is an effective process for the partial repair of bonded retainers.

The vitamin D receptor (VDR) acts as both a nuclear transcription factor and a non-genomic mediator that regulates a broad spectrum of physiological processes beyond calcium and phosphate homeostasis. VDR plays an important role in the modulation of ion channels across multiple tissues, including osteoblasts, renal and intestinal epithelial cells, neurons, and vascular smooth muscle. These regulatory mechanisms encompass genomic actions through vitamin D response elements in target genes—such as TRPV5, TRPV6, KCNK3, and KCNH1—as well as rapid, non-genomic actions at the plasma membrane involving protein disulfide isomerase A3 and associated signaling cascades. VDR-mediated transcriptional control of calcium, potassium, and chloride channels contributes to the fine-tuning of cellular excitability, calcium transport, and mitochondrial function. Evidence also implicates VDR–ion channel crosstalk in various pathological contexts, including renal cell carcinoma, breast and cervical cancers, pulmonary arterial hypertension, and osteoporosis. Understanding the molecular interplay between VDR and ion channels provides new perspectives on the pleiotropic effects of vitamin D and offers promising therapeutic opportunities in oncology, cardiovascular disease, and skeletal disorders. This review synthesizes previous and current evidence on the genomic and non-genomic mechanisms underlying VDR–ion channel regulation and highlights novel frontiers in vitamin D signaling relevant to human health and disease.

This paper presents a practical optimization framework for improving trajectory feasibility in constrained nonlinear optimal control problems for agile unmanned aerial vehicles (UAVs). The proposed method addresses trajectory optimization problems with non-convex geometric constraints, where gradient-based solvers often fail to converge to feasible solutions. The framework combines Model Predictive Path Integral (MPPI) control and the Augmented Lagrangian iterative Linear Quadratic Regulator (AL-iLQR). MPPI is employed as a fast sampling-based guidance mechanism to explore feasible regions of the trajectory space, while AL-iLQR is used to efficiently refine locally optimal solutions with high numerical accuracy. By decoupling feasibility exploration from local optimal refinement, the proposed method mitigates the sensitivity of gradient-based trajectory optimization to initialization in highly constrained environments. Numerical simulations involving both simplified two-dimensional dynamics and full quadrotor models demonstrate that the proposed approach significantly improves the probability of converging to feasible and dynamically consistent trajectories compared with AL-iLQR alone. The proposed method does not aim to provide theoretical guarantees of global optimality; instead, it offers a practical and computationally efficient strategy for enhancing feasibility and robustness in real-time UAV trajectory optimization.

This was a retrospective study using the Diagnosis Procedure Combination (DPC) database. Using a large national database, we aimed to investigate the epidemiology, treatment patterns, and outcomes of cervical fracture dislocation (CFD) among adolescents. There have been numerous clinical studies on CFD in adults. However, the current lack of studies on adolescent CFD is a clinically relevant research gap that urgently needs to be addressed. Among 4,653 inpatients who were identified to have a definitive diagnosis of CFD from 2010 to 2021 from the DPC database, we extracted the medical data of 84 adolescent inpatients (aged 11-18 years). CFD in adolescent inpatients was rare, accounting for only 1.8% of all patients with CFD in the DPC database. Complications occurred in 31 patients (36.9%), and mortality rate was 9.5%. Of eight patients who died, four were complicated by traumatic brain injury. Polytrauma was found in 32 patients (38.1%), and its incidence was significantly higher in those with mental disorders (p <0.001). The proportion of patients who were discharged home was significantly lower in those with mental disorders than in those without mental disorders (p =0.01). This epidemiological study provided new insights into adolescent CFD using real-world data. Future research should focus on the evaluation of long-term functional prognosis and development of preventive strategies and improved treatments for CFD in adolescent patients.

The aim of this study was to investigate the potential role of the trigeminal ganglion (TG)-trigeminal spinal subnucleus oralis (Vo) pathway in the orofacial neuropathic pain development, using a male rat model with partial ligation of the infraorbital nerve (PNL). Many TG-Vo neurons were found to have axon collaterals projecting to the trigeminal spinal subnucleus caudalis (Vc). The head-withdrawal threshold to mechanical stimulation of the whisker pad skin (MHWT) was significantly reduced in PNL rats compared with sham rats, and this reduction was reversed by Vo deactivation produced by quinolinic acid (QA) administration to Vo. Optogenetic stimulation of TG-Vo neurons in naïve rats induced a significantly increased frequency of freezing behavior and decreased MHWT. Vc or Vo deactivation by QA reduced the freezing frequency induced by optogenetic stimulation of TG-Vo neurons, and the MHWT reduction was significantly reversed after QA-Vc injection. Wide dynamic range (WDR) neurons in the Vo showed enhanced excitability to mechanical stimulation of the whisker pad skin in PNL rats compared with sham rats. The number of calcitonin gene-related peptide (CGRP)- and transient receptor potential Ankyrin 1 (TRPA1)-positive TG-Vo neurons was also significantly larger in PNL rats. Many CGRP-immunoreactive neurons also exhibited TRPA1 immunoreactivity. Ca 2+ influx responding to TRPA1 agonist treatment was significantly higher in cultured TG-Vo neurons in PNL rats compared with sham rats. Vo WDR neuronal activity was attenuated by subcutaneous injection of the TRPA1 antagonist into the whisker pad in PNL rats. These findings suggest that TG-Vo nociceptive neuronal activity is significantly enhanced following trigeminal nerve injury, indicating that the TG-Vo pathway is involved in orofacial neuropathic pain development.

Blood pressure (BP) typically decreases during sleep, known as the "dipping" pattern. A "nondipper", characterized by <10% BP reduction during sleep, has an elevated cardiovascular risk. Intermittent hypoxia (IH) is used to model hypertension with sleep apnea, but its relation with BP dipping and its effect on the kidney remains unclear. Male C57BL/6J (WT) mice were exposed to either normoxia (NX) or IH (O 2 concentration reduced to 5% in 90 s every 3 min during 8 h within the light period, for >1 week). BP was measured by radiotelemetry, and the dipping state was assessed by comparing mean BP (MBP) between light and dark periods. High- or low-salt diet (8% or 0.05% NaCl) and Slc12a3-/- mice (NCC-KO) were used to clarify the role of renal mechanism in the IH model mice. WT mice exhibited a dipping BP pattern under NX, but showed a nondipping pattern under chronic IH. Low-salt diet restored the dipping pattern and high-salt diet reinduced the nondipping one in the IH-model mice. Chronic IH increased the phosphorylation of Na-Cl cotransporter (NCC) and Na-K-Cl cotransporter (NKCC2) in the kidney, without affecting ENaCα cleavage. Even NCC-KO mice showed a dipping pattern of BP under NX, which shifted to a nondipping pattern under chronic IH. As expected, treatment with furosemide restored the dipping pattern in NCC-KO mice under chronic IH. Chronic IH disrupts the physiological dipping pattern of BP through NCC and NKCC2 activation. This study underscores the kidney's role in the pathophysiology of nondippers with sleep apnea.