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Electrical stimulation of cells and tissues for therapeutic benefit is a well-established method. Although animal studies can emulate the complexity of an organism’s physiology, lab-on-a-chip platforms provide a suitable primary model for follow-up animal studies. Thus, inexpensive and easy-to-use platforms for in vitro human cell studies are required. In the present study, we designed a micro-electrical impulse (micro-EI)-on-a-chip (micro-EI-chip), which can precisely control electron density and adjust the frequency based on a micro-EI. The micro-EI-chip can stimulate cells at various micro-EI densities (0–500 mV/mm) and frequencies (0–300 Hz), which enables multiple co-culture of different cell types with or without electrical stimulation. As a proof-of-concept study, a model involving degenerative inflamed human annulus fibrosus (hAF) cells was established in vitro and the effects of micro-EI on inflamed hAF cells were evaluated using the micro-EI-chip. Stimulation of the cells (150 mV/mm at 200 Hz) inhibited the secretion of inflammatory cytokines and downregulated the activities of extracellular matrix-modifying enzymes and matrix metalloproteinase-1. These results show that micro-EI stimulation could affect degenerative diseases based on inflammation, implicating the micro-EI-chip as being useful for basic research of electroceuticals.

Destruction of extracellular matrix (ECM) leads to degeneration of the intervertebral disk (IVD), which is a major contributor to many spine disorders. IVD degeneration is induced by pro-inflammatory cytokines, such as tumor necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1β), which are secreted by immune cells, including macrophages and neutrophils. The cytokines modulate ECM-modifying enzymes such as matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in human annulus fibrosus (AF) cells. The resulting imbalance in catabolic and anabolic enzymes can cause generalized back, neck, and low back pain (LBP). Photobiomodulation (PBM) is known to regulate inflammatory responses and wound healing. The aim of this study was to mimic the degenerative IVD microenvironment, and to investigate the effect of a variety of PBM conditions (wavelength: 635, 525, and 470 nm; energy density: 16, 32, and 64 J/cm(2)) on the production of ECM-modifying-enzymes by AF cells under degenerative conditions induced by macrophage-conditioned medium (MCM), which contains pro-inflammatory cytokines such as TNF-α and IL-β secreted by macrophage during the development of intervertebral disk inflammation. We showed that the MCM-stimulated AF cells express imbalanced ratios of TIMPs (TIMP-1 and TIMP-2) and MMPs (MMP-1 and MMP-3). PBM selectively modulated the production of ECM-modifying enzymes in AF cells. These results suggest that PBM can be a therapeutic tool for degenerative IVD disorders.

OBJECT An in vitro study was performed to understand the potential roles of matrix metalloproteinase (MMP)-2 and MMP-9 in the elastin degradation of human ligamentum flavum (LF) cells via treatment with tumor necrosis factor-α (TNFα) and interleukin-1β (IL-1β). Previous studies have identified a decreased elastin to collagen ratio in hypertrophic LF. Among the extracellular matrix remodeling endopeptidases, MMP-2 and MMP-9 are known to have elastolytic activity. The hypothesis that activated LF cells exposed to inflammation would secrete MMP-2 and MMP-9, thereby resulting in elastin degradation, was examined. METHODS To examine MMP-2 and MMP-9 expression in human LF, cells were isolated and cultured from LF tissues that were obtained during lumbar disc surgery. Isolated LF cells were equally divided into 3 flasks and subcultured. Upon cellular confluency, the LF cells were treated with TNFα, IL-1β, or none (as a control) and incubated for 48 hours. The conditioned media were collected and assayed for MMP-2 and MMP-9 using gelatin zymography and Western blot analysis. The electrophoresis bands were compared on densitometric scans using ImageJ software. RESULTS The conditioned media from the isolated human LF cells naturally expressed 72-kD and 92-kD gelatinolytic activities on gelatin zymography. The IL-1β-treated LF cells presented sustained increases in the proenzyme/zymogen forms of MMP−2 and −9 (proMMP-2 and proMMP-9), and activeMMP-9 expression (p = 0.001, 0.022, and 0.036, respectively); the TNFα-treated LF cells showed the most elevated proMMP9 secretion (p = 0.006), as determined by Western blot analyses. ActiveMMP-2 expression was not observed on zymography or the Western blot analysis. CONCLUSIONS TNFα and IL-1β promote proMMP-2 and proMMP-9 secretion. IL-1β appears to activate proMMP-9 in human LF cells. Based on these findings, selective MMP-9 blockers or antiinflammatory drugs could be potential treatment options for LF hypertrophy.

Mn-doped Zn2SiO4 thin films were deposited on Si (100) substrates by radio-frequency (RF) magnetron sputtering. The deposited films were then annealed at temperatures ranging from 600 to 1200 °C in an air ambient for 1 hour. The as-deposited Zn2SiO4:Mn films exhibited an amorphous structure having a smooth surface and showed no photoluminescence (PL). Annealing at 600 °C was found to have little effect on the properties of the films. The films still remained amorphous with no PL. After annealing at 800 °C, the films were crystallized in a mixture of orthorhombic β-Zn2SiO4 and rhombohedral α-Zn2SiO4 phases. These films showed a PL emission spectrum that could be resolved into two bands, one centered at 520 nm in the green region and the other at 571 nm in the yellow region. The green PL emission originated from the 4T1 → 6A1 intrashell transition of Mn2+ ions in the α-Zn2SiO4 phase while the yellow emission was attributed to Mn2+ ions in β-Zn2SiO4. The films annealed at and above a temperature of 900 °C exhibited only the α-Zn2SiO4 phase, and the PL spectra of these films showed only the green emission band with a peak maximum at around 523 nm. The PL emission intensity increased with increasing annealing temperature, which was due to the better crystalline quality and the rougher surface morphology of the Zn2SiO4:Mn films annealed at higher temperatures.

The conventional commercial winding synchronous motor system has a disadvantage in terms of efficiency and vehicle applicability since it has a separate packaging structure for the motor with inverter in the perspective of the design for electric vehicles. Therefore, a single system packaging research has been regarded to technical trend to enable size optimization, and the high efficiency cooling structure has been recognized as an important design issue accordingly. In this study, effectiveness of coolant flow rate of single packaged WFSM-inverter unit with dual coolant passage has been investigated through the computational fluid dynamics and experimental verification. Then, adequate design range considering motor operation stability and energy efficiency has been suggested.

Intervertebral disc (IVD) degeneration is associated with imbalances between catabolic and anabolic responses, regulated by extracellular matrix (ECM)-modifying enzymes such as matrix metalloproteinases (MMPs) and their endogenous tissue inhibitors of metalloproteinases (TIMPs). Potential contributing factors, such as interleukin (IL)-1β and tumor necrosis factor (TNF)-α, derived from infiltrated, activated macrophages within IVD tissues, can trigger abnormal production of ECM-modifying enzymes and progression of IVD degeneration. Novel therapies for regulating ECM-modifying enzymes can prevent or ameliorate IVD degeneration. Photobiomodulation (PBM), known to regulate wound repair, exhibits regenerative potential by modulating biological molecules. This study examined the effects of PBM, administered at various wavelengths (630, 525, and 465 nm) and energy densities (16, 32, and 64 J/cm2), on the production of ECM-modifying enzymes in replicated degenerative IVD. Our results showed that PBM selectively inhibited the production of ECM-modifying enzymes in a dose- and wavelength-dependent manner, suggesting that it could be a novel tool for treating symptomatic IVD degeneration.

A multi-copter or drone is a small, typically unmanned helicopter having more than two rotors. As the use of multi-copter has increased rapidly in recent years in a wide range of field such as military, agriculture, logistics, academic, surveillance and leisure, technical requirement for long-term use are inevitably followed. As a limitation on the long-term use of the multi-copter, excessive heat generation of the driving motor is regarded as one of the main causes. In order to solve this problem, it is essential to design an optimal heat dissipation structure. In this study, 3D computational fluid dynamics investigation and experimental verification have been performed to evaluate the effectiveness of ventilation holes on the cooling performance of the outer-rotor type BLDC motor used for a multi-copter. Then, adequate ventilation hole design is suggested through the comparative analysis of main heat transfer path and dominant internal flow path via Computational Fluid Dynamics.

This study was designed to investigate (i) extracellular matrix to specify adhesive substrates to human dura mater cell (hDMC); (ii) the alteration on adhesion-related molecules in hDMC; and (iii) secreted matrix metalloproteinases (MMPs) linked with extracellular matrix remodeling after exposure to inflammation. The hDMC was cultured from human dura mater tissue, and the studies were performed with hDMC after co-culturing with macrophage like THP-1 cells (Mϕ). The adhesion of co-cultured hDMC through collagen I increased 6.4-fold and through collagen IV increased 5.0-fold compared with the adhesion of naïve cells (p 0.001). Integrin subtype α

Objective To introduce our technique and results of retropleural/peritoneal lateral pediculectomy for the decompression of thoracolumbar fractures and reconstruction using an expandable titanium cage and circumferential fixation at a single stage. Methods Eighteen patients who had single unstable, burst thoracolumbar fracture were treated by this technique between January 2014 and December 2016 (T12: n = 9, L1: n = 7, L2: n = 2). They were reviewed retrospectively in terms of radiologic outcomes (computed tomography [CT] scan and radiograph), clinical outcomes, and complications. The results were compared with another cohort of thoracolumbar fractures treated by posterior-only surgery. Results There were no radiologic complications implying pseudoarthrosis or instrument failure on the postoperative 6-month CT scan. There was also no neurologic deterioration or infection during the same period. Two patients (11.1%) of iatrogenic injury and 1 patient of trauma-related injury of the dura were secured without any delayed complications. Three patients (16.7%) with transient weakness in left hip flexion immediately after operation were observed and recovered within 2 weeks in all cases. Six patients (33.3%) complained of dysesthesia and/or hypoesthesia on the incision site. Conclusions In this study, we suggest lateral pediculectomy as a distinct anatomic landmark to access and remove bony fragments effectively and safely in unstable thoracolumbar burst fractures. This provides a more straightforward access to the burst fragment and helps the surgeon to make better intraoperative decompression strategies. Moreover, this circumferential instrumentation with anterior support and fusion revealed better restoration of the thoracolumbar spine alignment compared with posterior-only surgery, with acceptable complications rates.

BACKGROUND Biochemical alterations associated with mechanical stress have been explored as an initiating step in the pathological progression of ligamentum flavum hypertrophy (LFH); however, this mechanism remains poorly understood. Recently, the inflammation induced after mechanical stress and the subsequent response of ligamentum flavum (LF) cells have been implicated in LFH pathology. OBJECTIVE To investigate the hypothesis that angiogenesis may be a critical link between hypertrophy and a series of stimulating events, including mechanical stress. METHODS LF from 20 lumbar spinal canal stenosis (LSCS) patients and 16 non-LSCS patients (control group) were collected during surgery. Patient demographic and radiographic data were obtained. The levels of angiogenic factors (vascular endothelial growth factor [VEGF], angiopoietin-1, vascular cell adhesion molecule, and basic fibroblast growth factor) in the LF were investigated by using an enzyme-linked immunosorbent assay. Angiogenesis was also quantified by immunohistochemical detection of CD34-positive capillaries. The correlations among clinical factors, including radiographic factors, angiogenic factors, and angiogenesis, were statistically analyzed. RESULTS The LSCS group was older and exhibited a longer symptom duration, wider segmental motion, and thicker LF than the control group. The LSCS group showed significantly higher tissue concentrations of VEGF (P < .001) that positively correlated with LF thickness (r = 0.557, P < .001) and segmental motion (r = 0.586, P < .001). The LSCS group showed significantly more CD34-positive capillaries than the control group (P = .004). CONCLUSION The LSCS group showed greater segmental motion, higher VEGF concentrations, and more CD34-positive capillaries than the control group. These data indicate that VEGF-mediated angiogenesis following mechanical stress may be a critical step within the series of pathological events in LFH.

Intervertebral disc degeneration (IVD) is one of the important causes of low back pain and is associated with inflammation induced by interaction between macrophages and the human annulus fibrosus (AF) cells. Low-level light therapy (LLLT) has been widely known to regulate inflammatory reaction. However, the effect of LLLT on macrophage-mediated inflammation in the AF cells has not been studied till date. The aim of this study is to mimic the inflammatory microenvironment and to investigate the anti-inflammatory effect of LLLT at a range of wavelengths (405, 532 and 650 nm) on the AF treated with macrophage-like THP-1 cells conditioned medium (MCM) containing proinflammatory cytokines and chemokines (interleukin-1beta, tumor necrosis factor-alpha, interleukin-6 and 8). We observed that AF cells exposed to MCM secrete significantly higher concentrations of IL-6, IL-8, IL-1β and TNF-α. LLLT markedly inhibited secretion of IL-6 at 405 nm in a time-dependent manner. Level of IL-8 was significantly decreased at all wavelengths in a time-dependent manner. We showed that MCM can induce the inflammatory microenvironment in AF cells and LLLT selectively suppressed IL-6 and 8 levels. The results indicate that LLLT is a potential method of IVD treatment and provide insights into further investigation of its anti-inflammation effect on IVD.

The aetiology of intervertebral disc (IVD) degeneration accompanied by low back pain (LBP) is largely unknown, and there are no effective fundamental therapies. Symptomatic IVD is known to be associated with nerve root compression. However, even in the absence of nerve compression, LBP occurs in patients with IVD degeneration. We hypothesize that this phenomenon is associated with a concentration of pro-inflammatory cytokines such as interleukin (IL)-1β and tumour necrosis factor-alpha (TNF-α), which can lead to altered histologic features and cellular phenotypes observed during IVD degeneration. This study investigated the effects of the concentration of IL-1β and macrophage derived soluble factor including IL-1β and TNF-α on the painful response of human annulus fibrosus (AF) cells using a newly developed spine-on-a-chip. Human AF cells were treated with a range of concentrations of IL-1β and macrophage soluble factors. Our results show that increasing the concentration of inflammatory initiator caused modulated expression of pain-related factors, angiogenesis molecules, and catabolic enzymes. Furthermore, accumulated macrophage derived soluble factors resulted in morphological changes in human AF cells and kinetic alterations such as velocity, dendritic length, cell area, and growth rate, similar to that reported within degenerative IVD. Thus, a better understanding of the relationships between molecular and kinetic alterations can provide fundamental information regarding the pathology of IVD degenerative progression.

The etiology of intervertebral disc (IVD) degeneration accompanied by low back pain (LBP) is largely unknown, and there are no curative therapies. Painful IVD degeneration is associated with infiltrated macrophage-mediated inflammatory response of human nucleus pulposus (NP) cells. The present study aimed to address the hypothesis that pro-inflammatory cytokines derived from macrophages lead to the altered molecular phenotype of human NP cells and to investigate the effects of phototherapy (630, 525, 465 nm with 16, 32, 64 J/cm2) on pain-related cytokine interleukin (IL)-6 and chemokine IL-8 under inflammatory conditions in human NP cells. Human NP cells were treated with soluble factors derived from macrophages in an inflammatory microenvironment, similar to that found in degenerative IVD. Human NP cells were also treated with phototherapy (630, 525, 465 nm with 16, 32, 64 J/cm2), and their cytokine and chemokine levels were detected. The soluble factors caused modulated expression of IL-6, IL-8, and matrix metalloproteinases (MMPs) at the gene and protein levels, causing a shift toward matrix catabolism through the expression of MMPs and increased pain-related factors via preferential activation of the nuclear factor-kappa B (NF-κB) p50 protein. Importantly, phototherapy attenuated the protein and gene expression of pain-related factor IL-6 at all doses and wavelengths. Interestingly, phototherapy also modulated the protein and gene expression of IL-8, which is responsible for the anabolic response, at a wavelength of 465 nm at all doses, in human NP cells. These findings suggested that phototherapy, at an optimal dose and wavelength, might be a useful therapeutic tool to treat IVD degeneration.

Compared to permanent magnet motors using rare-earth metals, a wound field synchronous motors tends to generate more heat due to increased windings, so it is required to consider cooling measures in design. In this study, a 3D computational fluid dynamics simulation and experimental verification of an 80kW Wound Field Synchronous Motor was performed to investigate the cooling performance of dual cooling passages. In order to evaluate the cooling effect of related design factors, a coolant temperature and coolant mass flow rate was considered in the analysis.

With recent advances in motion-sparing techniques in spine surgery, disc nucleus replacement (DNR) has been introduced as a viable method to restore the biomechanical functions of the spine. Several methods of DNR have been proposed in the literature. However, the risk of device migration or extrusion is a major issue that should be addressed for a successful DNR. DNR using a balloon nucleus (BN) filled with pressurized fluid may be capable of reducing such risks while preserving the advantages of DNR. The objective of this study was to investigate the biomechanical functionalities of the human cadaveric lumbar motion segments with a custom made BN filled with saline at internal fluid pressure of 0.3 MPa or 0.6 MPa in terms of axial and rotational flexibilities of the L4-L5 motion segment. Axial flexibility was quantified by the axial displacement resulting from an axial compressive force of 400 N while the rotational flexibility by the range of motions determined as the rotational angles in response to a pure moment of 6.0 Nm in flexion, extension, and right- and left-lateral bending directions. These tests were performed successively on the motion segment in the following conditions: intact, post nucleotomy, implanting BN with 0.3 MPa, and BN with 0.6 MPa. The nucleotomy was found to significantly increase both the axial and rotational flexibilities while the implantation of the BN reduced the axial and rotational flexibilities to those of the intact segment. The axial and rotational flexibilities of the segment with the BN with 0.3 MPa were greater than those of the segment with the BN with 0.6 MPa. This article is protected by copyright. All rights reserved

The flow characteristics in a volute-type centrifugal pump operating at design (Qd = 35 m3/h) and off-design (Qoff = 20 m3/h) conditions are investigated using large eddy simulation. Numerical results indicate that separation bubbles are generated on both the pressure and suction sides of impeller blades. At the off-design condition, the blade pressure side contains a larger recirculation zone with highly unsteady characteristics due to impeller-volute interactions. The vortices shed from a blade trailing edge due to its rotation strongly interact with those from the following blade and leakage through radial gaps at the off-design condition, generating stronger vortices in a wider region inside the volute, whereas this mutual interaction is weak at the design condition. Flow separation also occurs around the volute tongue at both operating conditions. At the off-design condition, a part of high-pressure fluid discharged from the volute does not follow the main stream to the outlet duct but re-enters into the volute area near the volute tongue. This pressurized fluid forms a high adverse pressure gradient on the blade pressure side, resulting in strong unsteady separation there. Also, a high pressure gradient in the axial direction at the radial gaps is formed especially near the volute tongue, creating the leakage into the cavities. Inside the volute, azimuthal vortices exist and grow along the volute passage. A secondary motion induced by these vortices also significantly affects the leakage to the cavities. All of these flow losses contain unsteady features that are strongly influenced by impeller-volute interactions, especially at the off-design condition.

Background context Neck pain (NP) is a common musculoskeletal disorder, but little is known about the associated risk factors. Purpose We compared anatomic differences in the neck and trunk area of young adult patients with chronic NP and control subjects without NP to identify risk factors and predictors. Study design This is an age-, sex-, and body mass index–matched retrospective case-control study of a consecutive sample. Patient sample Patients with axial NP for longer than 6 months (23 males and 25 females) and pain-free volunteers (23 males and 25 females) were included. Outcome measures Outcome measures were linear and angular dimensions of the cervicothoracic junction. Methods Midsagittal magnetic resonance imaging scans of the cervicothoracic spine were obtained. Four linear and four angular parameters were identified and measured. These parameters included depth of the T1-manubrium arch (T 1A D), depth of the thoracic cage (T X D), tangential height of T1 (T 1 H 1 ), relative height of T1 (T 1 H 2 ), T1 slope (T 1 S), thoracic inlet inclination (T i I), T1-manubrium arch inclination (T 1A I), and the angular difference between T i I and T 1A I (T i I−T 1A I). The measurements were taken by two neurosurgeons. Results Depth of the T1-manubrium arch and T i I were identified as predictors for NP in the binary logistic regression analysis. Each millimeter increase in T 1A D lessened the probability of NP with an adjusted odds ratio (OR) of 0.823 (95% confidence interval [CI], 0.701–0.966) in females and 0.809 (95% CI, 0.681–0.959) in males. Each degree increase in T i I was associated with the probability of NP with an adjusted OR of 1.247 (95% CI, 1.060–1.466) in males. Conclusions Measurement of cervicothoracic junctional structures is a reliable and feasible method of estimating potential predictor of chronic NP in young adults. Forward inclination of the thoracic inlet in males and a shallow thoracic cage in females were identified as important predictors.

ObjectivesThis study sought to investigate the association of beta-blocker therapy at discharge with clinical outcomes in patients with ST-segment elevation myocardial infarction (STEMI) after primary percutaneous coronary intervention (PCI).BackgroundLimited data are available on the efficacy of beta-blocker therapy for secondary prevention in STEMI patients.MethodsBetween November 1, 2005 and September 30, 2010, 20,344 patients were enrolled in nationwide, prospective, multicenter registries. Among these, we studied STEMI patients undergoing primary PCI who were discharged alive (n = 8,510). We classified patients into the beta-blocker group (n = 6,873) and no–beta-blocker group (n = 1,637) according to the use of beta-blockers at discharge. Propensity-score matching analysis was also performed in 1,325 patient triplets. The primary outcome was all-cause death.ResultsThe median follow-up duration was 367 days (interquartile range: 157 to 440 days). All-cause death occurred in 146 patients (2.1%) of the beta-blocker group versus 59 patients (3.6%) of the no–beta-blocker group (p < 0.001). After 2:1 propensity-score matching, beta-blocker therapy was associated with a lower incidence of all-cause death (2.8% vs. 4.1%, adjusted hazard ratio: 0.46, 95% confidence interval: 0.27 to 0.78, p = 0.004). The association with better outcome of beta-blocker therapy in terms of all-cause death was consistent across various subgroups, including patients with relatively low-risk profiles such as ejection fraction >40% or single-vessel disease.ConclusionsBeta-blocker therapy at discharge was associated with improved survival in STEMI patients treated with primary PCI. Our results support the current American College of Cardiology/American Heart Association guidelines, which recommend long-term beta-blocker therapy in all patients with STEMI regardless of reperfusion therapy or risk profile.

Objective : Symptomatic disc degeneration develops from inflammatory reactions in the annulus fibrosus (AF). Although inflammatory mediators during annular inflammation have been studied, the roles of matrix metalloproteinases (MMPs) and their inhibitors have not been fully elucidated. In this study, we evaluated the production of MMPs and tissue inhibitors of metalloproteinase (TIMPs) during annular inflammation using an in vitro coculture system. We also examined the effect of notochordal cells on annular inflammation. Methods : Human AF (hAF) pellet was co-cultured for 48 hours with phorbol myristate acetate–stimulated macrophage-like THP-1 cells. hAF pellet and conditioned media (CM) from co-cultured cells were assayed for MMPs, TIMPs, and insulin-like growth factor (IGF)-1 levels using real-time reverse-transcriptase polymerase chain reaction and enzyem-linked immunosorbent assay. To evaluate whether notochordal cells affected MMPs or TIMPs production on annular inflammation, hAF co-cultured with notochordal cells from adult New Zealand White rabbits, were assayed. Results : MMP-1, -3, -9; and TIMP-1 levels were significantly increased in CM of hAF co-cultured with macrophage-like cells compared with hAF alone, whereas TIMP-2 and IGF-1 levels were significantly decreased ( p

GaN thin films were deposited on Si (100) substrates at room temperature by RF magnetron sputtering of a GaN target in a pure N2 gas whose pressure ranged between 7 and 50 mTorr. The influence of N2 gas pressure on the structural properties of the deposited GaN films was systematically investigated. The crystalline structure in the GaN films changed from wurtzite to zinc-blende as the N2 gas pressure was reduced from 50 to 7 mTorr. The observed change in crystalline structure was found to correlate strongly with the changes in the microstructure, surface topography, and internal stress of the GaN films. The microstructure of the GaN films changed from a voided columnar structure having a rough surface to an extremely condensed structure with a very smooth surface morphology as the N2 gas pressure was decreased. The internal stress of the GaN films was slightly tensile (∼0.34 GPa) at 50 mTorr and became increasingly compressive upon decreasing the N2 gas pressure, reaching a value of ∼3.08 GPa at 7 mTorr. The above experimental results show that the N2 gas pressure plays a crucial role in determining the crystalline structure, microstructure, surface topography, and internal stress of the sputter-deposited GaN films.

The study analyzes the heating energy performance and water use reduction of the deteriorated single-family house with energy conservation measures (ECMs) such as double-glazing window, internal insulation, high-efficiency boiler, LED lightings, and water-saving closet. The building energy consumption and savings of each energy conservation measure are analyzed using the DesignBuilder program. The payback period and life cycle cost are analyzed to verify the indices of the cost effectiveness. As a result, the refurbishment of the internal insulation system is identified to be the most effective measure to save energy and cost. The simultaneous consideration of thermal insulation and high-efficient boiler helps the low-income bracket among the single-family houses of the old downtown area to increase their residential improvement.

Anterior foraminotomy (AF) is a surgical treatment for unilateral cervical radiculopathy that avoids fusion-related complications, but its long-term outcome has yet to be investigated. To clarify the efficacy of AF, the author retrospectively collected long-term data regarding the results of this technique.Of 50 patients who underwent AF between November 1999 and June 2005, those who were followed for more than 6 years (n = 44) were enrolled in this study. The parameters studied included the number of revisions, additional surgeries, VAS/NDI, and Odom's criteria. Plain radiographs were also obtained pre- and postoperatively.At discharge, 98% of patients reported improvement, although 20 % temporarily experienced some residual symptoms. There were no other major postoperative complications. At final follow-up (FU, mean of 8.8 years), an excellent or good outcome was achieved in 39 patients (89%). There was no index level reoperation required, but two additional operations for symptomatic adjacent-segment degeneration were needed (4.5%). Six patients suffered from shoulder pain on the same side after surgery (mean onset: 3.6 years). At final FU, significant degeneration at the operated level was demonstrated on plain radiographs, resulting in a decreased range of motion. However, loss of lordosis of the segment was minimal. Radiographically, adjacent segment degeneration was noted in only 6 and 11% at the cranial and caudal segments, respectively.In this retrospective study, patients who underwent AF for one- or two- level cervical radiculopathy showed a good long-term outcome with minimal adjacent segment degeneration. However, more data should be collected to clarify possible associations with these findings, such as delayed shoulder problems and aggravation of degeneration at the operated level.

The structure and the properties of gallium nitride (GaN) thin films prepared by using a radiofrequency (RF) magnetron sputtering method are reported. The GaN thin films were deposited on p-type (111)-oriented silicon substrates at room temperature in a pure nitrogen atmosphere. X-ray photoelectron spectra showed that the films were mainly composed of gallium and nitrogen. An oxygen impurity was found to be incorporated into the films during the deposition. The refractive index of the GaN films was measured to be 2.36 at a wavelength of 633 nm. The optical bandgap of the GaN films was determined to be approximately 3.31 eV. From the grazing incidence X-ray reflectivity measurements, the density and the surface roughness of the GaN films were estimated to be 5.827 g/cm3 and 2.95 nm, respectively. The X-ray diffraction analysis revealed that the crystalline phase of the GaN films changed from wurtzite to zinc-blende as the working gas pressure was reduced. The observed phase change was found to be independent of the orientation of the Si substrate, but to be strongly correlated with the biaxial compressive stress.

Spontaneous intracranial hypotension (SIH), typically presents with orthostatic headache, low pressure on lumbar tapping, and diffuse pachymeningeal enhancement on magnetic resonance imaging. SIH is often accompanied by subdural fluid collections, which in most cases responds to conservative treatment or spinal epidural blood patch. Several authors advocate that large subdural hematoma with acute deterioration merits surgical drainage; however, few have reported complications following craniotomy. We describe a complicated case of SIH, which was initially diagnosed as acute subarachnoid hemorrhage with bilateral chronic subdural hematoma (SDH), due to unusual presentation. Burr hole drainage of subdural hematoma was performed due to progressive decrease of consciousness, which then resulted in a huge postoperative epidural hematoma collection. Prompt hematoma evacuation did not restore the patient's consciousness but aggravated downward brain herniation. Trendelenburg position and spinal epidural blood patch achieved a rapid improvement in patient's consciousness. This case indicates that the surgical drainage for chronic SDH in SIH can lead to serious complications and it should be cautiously considered.

With recent advances in motion-sparing techniques in spine surgery, disc nucleus replacement (DNR) has been introduced as a viable method to restore the biomechanical functions of the spine. Several methods of DNR have been proposed in the literature. However, the risk of device migration or extrusion is a major issue that should be addressed for a successful DNR. DNR using a balloon nucleus (BN) filled with pressurized fluid may be capable of reducing such risks while preserving the advantages of DNR. The objective of this study was to investigate the biomechanical functionalities of the human cadaveric lumbar motion segments with a custom made BN filled with saline at internal fluid pressure of 0.3 or 0.6 MPa in terms of axial and rotational flexibilities of the L4-L5 motion segment. Axial flexibility was quantified by the axial displacement resulting from an axial compressive force of 400 N while the rotational flexibility by the range of motions determined as the rotational angles in response to a pure moment of 6.0 Nm in flexion, extension, and right- and left-lateral bending directions. These tests were performed successively on the motion segment in the following conditions: intact, post nucleotomy, implanting BN with 0.3 MPa, and BN with 0.6 MPa. The nucleotomy was found to significantly increase both the axial and rotational flexibilities while the implantation of the BN reduced the axial and rotational flexibilities to those of the intact segment. The axial and rotational flexibilities of the segment with the BN with 0.3 MPa were greater than those of the segment with the BN with 0.6 MPa. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:167-173, 2018.

Background The intervertebral disc (IVD) is an avascular structure, and is therefore stable under hypoxic conditions. Previous studies have demonstrated that hypoxia might be related to symptomatic degenerative disc diseases (DDDs); however, the pathomechanism is still poorly understood. Objective To identify the effect of hypoxia on the production of inflammatory mediators, angiogenic factors, and extracellular matrix-regulating enzymes of IVD cells during inflammatory reactions. Methods Human nucleus pulposus (NP) and annulus fibrosus (AF) cells harvested during surgery for DDDs were cultured in macrophage conditioned media or interleukin (IL)-1β-stimulated media under hypoxic (2%) and normoxic (21%) conditions. Hypoxia-inducible factor-1α transcription factor activation was analyzed by western blotting. IL-6, IL-8, vascular endothelial growth factor (VEGF), vascular cell adhesion molecule (VCAM), matrix metalloproteinase (MMP)-1, MMP-3, tissue inhibitor of metalloprotease (TIMP)-1, and TIMP-2 in conditioned media were measured by an enzyme-linked immunosorbent assay. Results NP cells expressed higher hypoxia-inducible factor-1α in the IL-1β-stimulated group under hypoxic condition. MMP-1 was significantly increased in the AF cells under hypoxic condition; TIMP-1 and TIMP-2 were significantly decreased in both naive NP and AF cells during hypoxia. Both cells in macrophage conditioned media significantly diminished the production of IL-6 and VCAM, while VEGF significantly increased during hypoxia. After 1 ng/mL IL-1β stimulation, IL-8, VEGF, MMP-1, and MMP-3 were significantly increased in both cell types during hypoxia, while VCAM, TIMP-1, and TIMP-2 were decreased. Conclusion We found that hypoxia can enhance the angiogenic ability of IVD during inflammatory reactions, and cause progress in development of DDD via extracellular matrix regulation in this in vitro study.

Background The self-expandable COMPLETE™ stent (Medtronic) has greater elasticity, allowing it to regain its shape after the compression force reduces, and has higher trackability, thus is easier to maneuver through tortuous vessels, whereas the balloon-expandable SCUBA™ stent (Medtronic) has higher radial stiffness and can afford more accurate placement without geographic miss, which is important in aortoiliac bifurcation lesions. To date, there have been no randomized control trials comparing efficacy and safety between the self-expanding stent and balloon-expandable stent in advanced atherosclerotic iliac artery disease. Methods/design The purpose of our study is to examine primary patency (efficacy) and incidence of stent fracture and geographic miss (safety) between two different major representative stents, the self-expanding nitinol stent (COMPLETE-SE™) and the balloon-expanding cobalt-chromium stent (SCUBA™), in stenotic or occlusive iliac arterial lesions. This trial is designed as a prospective, randomized, multicenter trial to demonstrate a noninferiority of SCUBA™ stent to COMPLETE-SE™ stent following balloon angioplasty in iliac arterial lesions, and a total of 280 patients will be enrolled. The primary end point of this study is the rate of primary patency in the treated segment at 12 months after intervention as determined by catheter angiography, computed tomography angiography, or duplex ultrasound. Discussion The SENS-ILIAC trial will give powerful insight into whether the stent choice according to deployment mechanics would impact stent patency, geographic miss, or stent fracture in patients undergoing stent implantation in iliac artery lesions. Trial registration National Institutes of Health Clinical Trials Registry (ClinicalTrials.gov identifier: NCT01834495), registration date: May 8, 2012 Electronic supplementary material The online version of this article (doi:10.1186/s13063-016-1435-9) contains supplementary material, which is available to authorized users.

OBJECTIVES The Korean Resource Based Relative Value Scale (K-RBRVS) was introduced in 2001 as an alternative of the previous medical fee schedule. Unfortunately, most neurosurgeons are unfamiliar with the details of the K-RBRVS and how it affects the reimbursement rates for the surgical procedures we perform. We summarize the K-RBRVS in brief, and discuss on how the relative value (RV) of the spinal neurosurgical procedures have changed since the introduction in 2001. METHODS We analyzed the change of spinal procedure RVs since 2001, and compared it with the change of values in the brain neurosurgical procedures. RVs of 88 neurospinal procedures on the list of K-RBRVS were analyzed, while 24 procedures added during annual revisions were excluded. RESULTS During the past 15 years, RVs for spinal procedures have increased 62.8%, which is not so different with the cumulative increase of consumer prices during this time period or the increase rate of 92.3% for brain surgeries. When comparing the change of RVs in more complex procedures between spinal and brain neurosurgery, the increase rate was 125.3% and 133%, respectively. CONCLUSION More effort of the society of spinal surgeons seems to be needed to get adequate reimbursement, as there have been some discrimination compared to brain surgeons in the increase of RVs. And considering the relative underestimation of spinal neurosurgeons' labor, more objective measures of neurospinal surgeons' work and productivity should be developed for impartial reimbursement.

BACKGROUND Cigarette smoking has been shown to be associated with a decreased risk of death after acute myocardial infarction (AMI), which is also known as the "smokers' paradox." This study aimed to investigate the relationship between smoking and all-cause mortality after AMI. METHODS We extracted the data of patients who were hospitalized for AMI between November 2005 and September 2010 from nationwide multicenter prospective registries in Korea. RESULTS Among a total of 29,199 patients with AMI, 10,251 (42.3%) were current smokers, and 14,006 (57.7%) were nonsmokers. Current smokers were younger, more likely to be male, and had lower frequencies of hypertension, diabetes mellitus, dyslipidemia, and previous history of ischemic heart disease than nonsmokers. The initial presentation was less severe in terms of hemodynamic status, and angiography showed less complex coronary involvement in smokers. The overall mortality rate was 5.4% for current smokers and 9.9% for nonsmokers (hazard ratio [HR], 0.52; 95% confidence interval [CI], 0.47-0.58; p < .001). The gap in risk was attenuated after multivariable adjustment but remained statistically significant (HR, 0.85; 95% CI, 0.76-0.95; p = .005). Propensity score matching corroborated the results of reduced mortality among current smokers (6.7% vs. 7.6%; p = .005). CONCLUSIONS In this study, in which the patients received up-to-date treatment options, smoking was associated with a 48% decrease in the risk of all-cause mortality at 1 year after AMI.

There is representative part among convenience items which increase convenience of driver while part that driver contacts most and recognizes easily sensuously among this convenience function drives into vehicles seat part. On high-reliability, high-tech of vehicles, convenience function in seat part is expanded greatly. Air conditioning ventilation system that can keep temperature comfortable environment on deluxe car among them is raised by important convenience function. This paper deals with a design of the seat cooling fan for vehicle, especially brushless DC (BLDC) motor and blade for cooling fan module. We achieved blade flow analysis about high effectiveness and presented various design data. We have used the 2D Finite Element Method for calculating the characteristics of brushless DC (BLDC) motor, computing fluid mechanics (CFD) as numerical analysis for blade design.

STUDY DESIGN We evaluated the influence of rabbit notochordal cells on the expression of inflammatory mediators by human annulus fibrosus (AF) cells cocultured with macrophage-like cells. OBJECTIVE To identify the protective effect of rabbit notochordal cells on AF during in vitro inflammation. SUMMARY OF BACKGROUND DATA Discogenic pain, which is an important cause of intractable lower back pain, is associated with macrophage-mediated inflammation in the AF. Although rabbit notochordal cells prevent intervertebral disc degeneration, their effects on human AF inflammation remain unknown. METHODS Human AF pellets were cocultured for 48 hours with notochordal cell clusters from adult New Zealand White rabbits and phorbol myristate acetate (PMA)-stimulated human macrophage-like THP-1 cells. Conditioned media (CM) from the cocultures were assayed by enzyme-linked immunosorbent assay. The expression of inflammatory mediators in the AF pellets was evaluated by real-time reverse-transcription polymerase chain reaction. RESULTS The levels of mRNA for interleukin (IL)-6, IL-8, and inducible nitric oxide synthase (iNOS) in the AF pellets cocultured with notochordal cells and macrophages (hAF[rNC-M]) were significantly lower than those in the AF pellets cultured with macrophages alone (hAF[M]) (P < 0.05). The levels of IL-6 and IL-8 proteins in the CM of hAF(rNC-M) were significantly lower than those in the CM of hAF(M) (P < 0.05). Coculturing with notochordal cells significantly decreased the levels of mRNA for IL-6, IL-8, and iNOS in the macrophage-exposed AF pellets (P < 0.05). After 1 ng/mL IL-1β stimulation, the levels of IL-6 and IL-8 mRNA and the level of IL-8 protein production were significantly decreased in the AF pellets with notochordal cells compared with naive AF pellets (P < 0.05). CONCLUSION In an in vitro coculture system, rabbit notochordal cells reduced the levels of main inflammatory mediators and gene expression in the human AF during inflammation. Therefore, rabbit notochordal cells may constitute an important protective tool against symptomatic disc development.

We report two cases of cervical spinal epidural abscess (SEA), which are related to anterior cervical surgeries. The first case reveals a late postoperative infection without any predisposing factor. The second case reveals combined complication of infection and instrument failure (artificial disc). Both two cases manifested ascending infections that are unusual courses of anterior cervical infections. The abscess extended upwards and, finally, caused life threatening bacterial meningitis. We suggest aggressive surgical interventions with anti-bacterial therapies in such cases.

The goodness-of-fit test for multivariate normal distribution is important because most multivariate statistical methods are based on the assumption of multivariate normality. We propose goodness-of-fit test statistics for multivariate normality based on the modified squared distance. The empirical percentage points of the null distribution of the proposed statistics are presented via numerical simulations. We compare performance of several test statistics through a Monte Carlo simulation.

CFD method could replace experiment for development of a fan, but it cannot be applicable to some of real design stage because of limitation that rotating speed must be set as boundary condition. That is, most experiments without a Dynamo set only voltage of a motor as input condition. The remarkable difference between the above mentioned experiment and the current CFD is that the rotating speed varies with flow rate. Therefore, the numerical results calculated by the boundary condition of constant rotating speed have limitation of real application, and especially, when predicting efficiency, there exists a striking difference from the real situation. In this article, we developed a new algorithm in which we are able to determine both static pressure and rotating speed through setting up the only voltage as a boundary condition with motor performance test results. The new developed algorithm on the basis of experiment and CFD showed good qualitative and accurate results with a significant difference of less than 5%.

Study design In vitro study about angiogenic potentiality of ligamentum flavum (LF) cells using coculture of human lumbar LF cells and activated macropage-like THP-1 cells. Objective To test our hypothesis that activated LF, which was exposed to inflammation, induces angiogenesis, thus resulting in hypertrophy. Summary of background data Inflammatory reactions after mechanical stress produce fibrosis and scarring of the LF that result in hypertrophy, a major pathological feature of spinal stenosis. This study evaluated the roles of LF cells in the pathomechanism of hypertrophy, focusing on angiogenesis. Methods To determine their response to the inflammatory reaction, human LF cells were cocultured with phorbol myristate acetate-stimulated macrophage-like THP-1 cells. The conditioned media were assayed for tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, IL-8, vascular endothelial growth factor (VEGF), and transforming growth factor (TGF)-β1. Naive and macrophage-exposed LF cells that responded to TNF-α/IL-1β were compared using the same outcome measures. Hypertrophied LF tissue was stained by TGF-β1 primary antibody using immunohistochemical method. Results Larger quantities of IL-6, IL-8, and VEGF were secreted by cocultured cells than by macrophages alone and LF cells alone combined. Prior macrophage exposure increased the secretion of IL-8 and VEGF in response to TNF-α/IL-1β stimulation whereas IL-6 production was increased in response to IL-1β. The coculture appeared to increase TGF-β1 secretion but the level was lower than that for macrophage-like cells alone and LF cells alone combined. Conclusion LF cells interact with macrophage-like cells to produce angiogenesis-related factors except TGF-β1. Activated LF cells that have been exposed to macrophage, can impact the inducement of angiogenesis-related factors, suggesting that fibrosis and scarring during inflammatory reaction is the major pathomechanism of LF hypertrophy.

Heavy vehicle cooling fan is seen as one of the main means of vehicular fuel efficiency reduction. This is becoming a major factor in city noise, and the necessity of electromagnetic technical development is very great. CFD method could replace experiment for development of heavy vehicle cooling fan, but it cannot be applicable to some of real design stage because of limitation that rotating speed must be set as boundary condition. In this article, we developed a new algorithm in which we are able to determine both static pressure and rotating speed through setting up the only voltage as a boundary condition with motor performance test results

Analytical current and capacitance models for amorphous Indium-Gallium-Zinc-Oxide Thin film transistors (a-IGZO TFTs) are proposed for application to the simulation of a-IGZO TFT-based circuits. The accuracy of the proposed models are verified by comparing the measured I-V and C-V characteristics with calculated ones and the simulation result of a-IGZO TFT-based circuits. The proposed models are expected to be useful both for the optimization of fabrication process and for the prospective estimation of the effect of process conditions on the circuit performance.

The effect of the active layer thickness (TIGZO) on the constant current stress (CCS)-induced threshold voltage shift (ΔVT) in amorphous InGaZnO (a-IGZO) thin-film transistors (TFTs) for AMOLED drivers is investigated by using a subgap density-of-states (DOS) model and simulation. The CCS-induced positive ΔVT in a-IGZO TFT with a thicker TIGZO is larger than that in a-IGZO TFTs with a thinner TIGO. It is originated from more activated charge trapping (60∼80 % in total ΔVT) and DOS creation due to a higher surface electric field with a thicker TIGZO. Our results show that using thinner active layer in a-IGZO TFTs is desirable for high performance and highly stable AMOLEDs if the quality of thin-film bulk is guranteed irrespective of TIGZO.

This paper presents a design method for a small-sized slotless brushless dc motor. Distributed hexagonal windings are employed for achieving a high torque density and for ease of manufacture. Numerical approaches with an analytic model are used to analyze the magnetic and output characteristics of the motor. The proposed motor is manufactured, and the empirical results are compared with the results of the simulation.

A 69-year-old male presented with a rare spinal angiolipoma manifesting as history of back pain, and numbness in both lower limbs, which progressed over a period of 5 years. Total T10-T12 laminectomy was performed and the tumor was removed en bloc. The symptoms gradually improved postoperatively. Spinal angiolipoma is an uncommon benign extradural tumor of spine, which accounts for 0.14-1.2% of all spinal tumors and is a rare cause of spinal cord compression. Recognition of this entity is crucial as a benign and curable cause of paraplegia and back pain.