In-air experimental achievement of high-voltage DC power supply to be installed in a tandem electrostatic accelerator system for boron neutron capture therapy application.

The boron neutron capture therapy (BNCT) system developed by the Korea Institute of Radiological and Medical Sciences is a compact neutron source that can be installed at medical institutes. The target energy was accelerated to a maximum of 2.4 MeV-20 mA by introducing a gas stripping device that converts negative hydrogen ions into positive ions. By using the tandem-type accelerator in this way, a high-voltage DC power supply was designed with 1.2 MV-45 mA as the maximum capability. The design was improved to reduce the number of stages of a Cockcroft-Walton voltage multiplier. Hence, the ripple risk of the DC flat top resulting from unwanted stray capacitance was lowered. The overall height and volume of the Cockcroft-Walton voltage multiplier were reduced to less than half those of the existing design method, making miniaturization possible. After such advanced design and manufacturing, performance tests were performed at 750 kV-45 mA under 23 stages of the Cockcroft-Walton voltage multiplier, which is the highest level that can perform at its maximum under in-air conditions. It demonstrated stable performance under in-air conditions without breakdown for 2 h, even at 620 kV-35 mA. To reach the final target of 1.2 MV-45 mA, the groundwork is laid for achieving experimental performance while satisfying the optimal requirements in SF6 gas.

Predictors of embolism and death in left-sided infective endocarditis: the European Society of Cardiology EURObservational Research Programme European Infective Endocarditis registry.

BACKGROUND AND AIMS: Even though vegetation size in infective endocarditis (IE) has been associated with embolic events (EEs) and mortality risk, it is unclear whether vegetation size associated with these potential outcomes is different in left-sided IE (LSIE). This study aimed to seek assessing the vegetation cut-off size as predictor of EE or 30-day mortality for LSIE and to determine risk predictors of these outcomes. METHODS: The European Society of Cardiology EURObservational Research Programme European Infective Endocarditis is a prospective, multicentre registry including patients with definite or possible IE throughout 2016-18. Cox multivariable logistic regression analysis was performed to assess variables associated with EE or 30-day mortality. RESULTS: There were 2171 patients with LSIE (women 31.5%). Among these affected patients, 459 (21.1%) had a new EE or died in 30 days. The cut-off value of vegetation size for predicting EEs or 30-day mortality was >10 mm [hazard ratio (HR) 1.38, 95% confidence interval (CI) 1.13-1.69, P = .0015]. Other adjusted predictors of risk of EE or death were as follows: EE on admission (HR 1.89, 95% CI 1.54-2.33, P < .0001), history of heart failure (HR 1.53, 95% CI 1.21-1.93, P = .0004), creatinine >2 mg/dL (HR 1.59, 95% CI 1.25-2.03, P = .0002), Staphylococcus aureus (HR 1.36, 95% CI 1.08-1.70, P = .008), congestive heart failure (HR 1.40, 95% CI 1.12-1.75, P = .003), presence of haemorrhagic stroke (HR 4.57, 95% CI 3.08-6.79, P < .0001), alcohol abuse (HR 1.45, 95% CI 1.04-2.03, P = .03), presence of cardiogenic shock (HR 2.07, 95% CI 1.29-3.34, P = .003), and not performing left surgery (HR 1.30 95% CI 1.05-1.61, P = .016) (C-statistic = .68). CONCLUSIONS: Prognosis after LSIE is determined by multiple factors, including vegetation size.

Central hemodynamics and the discrepancy between central blood pressure and brachial blood pressure.

Despite similar brachial blood pressure, central hemodynamics could be different. The objective of the present study was to investigate the factors, which could influence the discrepancy between central BP (cBP) and brachial blood pressure. Six hundred forty-seven patients (364 males, 48 ± 12 years old) were enrolled. Using applanation tonometry, cBP was noninvasively derived. The median difference between brachial systolic BP (bSBP) and central systolic BP (cSBP) was 8 mm Hg. We defined the discrepancy between bSBP and cSBP as differences >8 mm Hg. For adjustment of cBP, population was divided into 3 groups according to the cBP: group 1, <140 mm Hg of cSBP; group 2, 140 > cSBP < 160 mm Hg; group 3, =160 mm Hg of cSBP. All the central hemodynamic parameters of the patients, including augmentation pressure, augmentation index (AI), heart rate (75 bpm) adjusted augmentation index (AI@HR75), and subendocardial viability ratio, were measured. Using multivariate logistic regression analysis, we evaluated the factors which could influence the discrepancy between bSBP and cSBP. Age, gender, augmentation pressure, AI, and AI@HR75 were correlated with the discrepancy between bSBP and cSBP. AI@HR75 was significantly correlated with the discrepancy between bSBP and cSBP (ß-coefficient = -0.376, P < .001 in group 1; ß-coefficient = -0.297, P < .001 in group 2; and ß-coefficient = -0.545, P < .001 in group 3). In groups 1 and 2, male gender was significantly correlated with the discrepancy between bSBP and cSBP (ß-coefficient = -0.857, P = .035 in group 1; ß-coefficient = -1.422, P = .039 in group 2). In present study, arterial stiffness might affect the discrepancy between bSBP and cSBP. Also, male gender was closely related to the discrepancy between bSBP and cSBP especially with cSBP <160 mm Hg. Not only cSBP, the discrepancy between cSBP and bSBP should be considered for understanding the central hemodynamics.

The gate injection-based field-effect synapse transistor with linear conductance update for online training.

Neuromorphic computing, an alternative for von Neumann architecture, requires synapse devices where the data can be stored and computed in the same place. The three-terminal synapse device is attractive for neuromorphic computing due to its high stability and controllability. However, high nonlinearity on weight update, low dynamic range, and incompatibility with conventional CMOS systems have been reported as obstacles for large-scale crossbar arrays. Here, we propose the CMOS compatible gate injection-based field-effect transistor employing thermionic emission to enhance the linear conductance update. The dependence of the linearity on the conduction mechanism is examined by inserting an interfacial layer in the gate stack. To demonstrate the conduction mechanism, the gate current measurement is conducted under varying temperatures. The device based on thermionic emission achieves superior synaptic characteristics, leading to high performance on the artificial neural network simulation as 93.17% on the MNIST dataset.

Surface ECG-based complexity parameters for predicting outcomes of catheter ablation for nonparoxysmal atrial fibrillation: efficacy of fibrillatory wave amplitude.

Catheter ablation (CA) is a well-established therapy for rhythm control in atrial fibrillation (AF). However, CA outcomes for persistent AF remain unsatisfactory because of the high recurrence rate despite time-consuming efforts and the latest ablation technology. Therefore, the selection of good responders to CA is necessary. Surface electrocardiography (sECG)-based complexity parameters were tested for the predictive ability of procedural termination failure during CA and late recurrence of atrial arrhythmias (AA) after CA. A total of 130 patients with nonparoxysmal AF who underwent CA for the first time were investigated. A 10-second sECG of 4 leads (leads I, II, V1, and V6) was analyzed to compute the fibrillatory wave amplitude (FWA), dominant frequency (DF), spectral entropy (SE), organization index (OI), and sample entropy (SampEn). The study endpoints were procedural termination failure during CA and late (≥1 year) AA recurrence after CA. In the multivariate analysis, FWA in lead V1 and DF in lead I were independent predictors of successful AF termination during CA (P <.05). The optimal cut-off values for FWA in lead V1 and DF in lead I were 60.38 µV (area under the curve [AUC], 0.672; P = .001) and 5.7 Hz (AUC, 0.630; P = .016), respectively. The combination of FWA of lead V1 and DF of lead I had a more powerful odds ratio for predicting procedural termination failure (OR, 8.542; 95% CI, 2.938-28.834; P < .001). FWA in lead V1 was the only independent predictor of late recurrence after CA. The cut-off value is 65.73 µV which was 0.634 of the AUC (P = .009). These sECG parameters, FWA in lead V1 and DF in lead I, predicted AF termination by CA in patients with nonparoxysmal AF. In particular, FWA in lead V1 was an independent predictor of late recurrence of AA after CA.

Optimal design of high-voltage DC power supply of 1.2 MV/45 mA applied to boron neutron capture therapy system.

To build a proton beam accelerator that can be applied to a boron neutron capture therapy system based on an electrostatic accelerator, a high-voltage direct-current (DC) power supply system equivalent to the generation of neutrons should be provided. The symmetrical Cockcroft-Walton voltage multiplier method is suitable for stable acceleration of the proton beam in the tandem electrostatic accelerator in this system. Before the second step-up with the Cockcroft-Walton circuit, the design of the inverter is prioritized by preponderantly considering the first voltage and resonance frequency. Moreover, the optimized stacking number is determined with consideration of the ripple voltage, voltage drop, average output voltage, and fundamental harmonics, and a design is performed to set related parameter values to be stable in the flat-top region of the voltage. A high-voltage DC power supply system of 1.2 MV/45 mA is needed for a stable terminal energy of 2.4 MeV/20 mA. Such a design can be optimized by securing reliable data using a simulation tool on the basis of theoretical calculations. This will become a formidable touchstone in manufacturing technology based on acquiring practical know-how for setting up a tandem electrostatic accelerator-based boron neutron capture therapy system in the future.

Effects of Irradiation on Brain Tumors Using MR-Based Electrical Conductivity Imaging.

Ionizing radiation delivers sufficient energy inside the human body to create ions, which kills cancerous tissues either by damaging the DNA directly or by creating charged particles that can damage the DNA. Recent magnetic resonance (MR)-based conductivity imaging shows higher sensitivity than other MR techniques for evaluating the responses of normal tissues immediately after irradiation. However, it is still necessary to verify the responses of cancer tissues to irradiation by conductivity imaging for it to become a reliable tool in evaluating therapeutic effects in clinical practice. In this study, we applied MR-based conductivity imaging to mouse brain tumors to evaluate the responses in irradiated and non-irradiated tissues during the peri-irradiation period. Absolute conductivities of brain tissues were measured to quantify the irradiation effects, and the percentage changes were determined to estimate the degree of response. The conductivity of brain tissues with irradiation was higher than that without irradiation for all tissue types. The percentage changes of tumor tissues with irradiation were clearly different than those without irradiation. The measured conductivity and percentage changes between tumor rims and cores to irradiation were clearly distinguished. The contrast of the conductivity images following irradiation may reflect the response to the changes in cellularity and the amounts of electrolytes in tumor tissues.

Image-Based Evaluation of Irradiation Effects in Brain Tissues by Measuring Absolute Electrical Conductivity Using MRI.

Radiation-induced injury is damage to normal tissues caused by unintentional exposure to ionizing radiation. Image-based evaluation of tissue damage by irradiation has an advantage for the early assessment of therapeutic effects by providing sensitive information on minute tissue responses in situ. Recent magnetic resonance (MR)-based electrical conductivity imaging has shown potential as an effective early imaging biomarker for treatment response and radiation-induced injury. However, to be a tool for evaluating therapeutic effects, validation of its reliability and sensitivity according to various irradiation conditions is required. We performed MR-based electrical conductivity imaging on designed phantoms to confirm the effect of ionizing radiation at different doses and on in vivo mouse brains to distinguish tissue response depending on different doses and the elapsed time after irradiation. To quantify the irradiation effects, we measured the absolute conductivity of brain tissues and calculated relative conductivity changes based on the value of pre-irradiation. The conductivity of the phantoms with the distilled water and saline solution increased linearly with the irradiation doses. The conductivity of in vivo mouse brains showed different time-course variations and residual contrast depending on the irradiation doses. Future studies will focus on validation at long-term time points, including early and late delayed response and evaluation of irradiation effects in various tissue types.

Metallothionein 2 activation by pravastatin reinforces epithelial integrity and ameliorates radiation-induced enteropathy.

BACKGROUND: Radiotherapy or accidental exposure to ionizing radiation causes severe damage of healthy intestinal tissues. Intestinal barrier function is highly sensitive to ionizing radiation, and loss of epithelial integrity results in mucosal inflammation, bacterial translocation, and endotoxemia. Few studies have of epithelial integrity as a therapeutic target to treat radiation toxicity. Here, we examined the effects of pravastatin (PS) and the molecular mechanisms underlying epithelial integrity on radiation-induced enteropathy. METHODS: The radio-mitigative effects of PS were evaluated in a minipig model by quantifying clinical symptoms, and performing histological and serological analyses and mRNA sequencing in intestinal tissues. To evaluate the role of intercellular junctions on radiation damage, we used tight junction regulator and metallothionein 2 (MT2) as treatments in a mouse model of radiation-induced enteropathy. Caco-2 monolayers were used to examine functional epithelial integrityand intercellular junction expression. FINDING: Using a minipig model of pharmaceutical oral bioavailability, we found that PS mitigated acute radiation-induced enteropathy. PS-treated irradiated minipigs had mild clinical symptoms, lower intestinal inflammation and endotoxin levels, and improved gastrointestinal integrity, compared with control group animals. The results of mRNA sequencing analysis indicated that PS treatment markedly influenced intercellular junctions by inhibiting p38 MAPK signaling in the irradiated intestinal epithelium. The PS-regulated gene MT2 improved the epithelial barrier via enhancement of intercellular junctions in radiation-induced enteropathy. INTERPRETATION: PS regulated epithelial integrity by modulating MT2 in radiation-damaged epithelial cells. These findings suggested that maintenance of epithelial integrity is a novel therapeutic target for treatment of radiation-induced gastrointestinal damage. FUNDING: As stated in the Acknowledgments.

Efficiency of minimal oblique resection of the uncinate process during an anterior cervical discectomy and fusion.

ABSTRACT: Hypertrophy of the uncinate process (UP) can cause radiculopathy. Minimal UP resection is considered to remove the lesion while minimizing the risk of complications. This study aimed to elucidate the surgical results of minimal oblique resection of the UP. This study is a retrospective review of about sixty segments in 34 patients who underwent anterior cervical discectomy and fusion (ACDF) with minimal oblique uncinectomy between 2016 and 2018. The cross-sectional area of the UP was measured pre- and postoperatively. The interspinous distance, segmental Cobb angle, subsidence, fusion rate, surgical time, estimated blood loss, and postoperative complications were evaluated. The mean resected areas of the UP were 17.4 ±â€Š8.7 mm2 (25.9%) on the right and 17.3 ±â€Š11.2 mm2 (26.2%) on the left. The difference in interspinous distance in flexion-extension was 7.1 ±â€Š3.2 and 1.6 ±â€Š0.6 mm pre- and postoperatively, respectively (P = .000). The fusion rate after ACDF was 91.7% when measured according to segment (55/60) and 91.2% when measured according to patients (31/34). The difference in the segmental Cobb angle in flexion-extension was 8.3 ±â€Š6.2° and 1.9 ±â€Š0.3° pre and postoperatively, respectively (P = .000). Subsidence occurred in 4 (11.8%) patients and 5 (8.3%) segments. The average surgical time per segment was 68.8 ±â€Š9.3 minute, and the estimated blood loss was 48.5 ±â€Š25.0 mL. Postoperative complications comprised 1 case each of neck swelling, wound infection, pneumonia, and gastrointestinal bleeding. Our findings therefore revealed that minimal oblique uncinectomy during an ACDF can maintain the stability of the uncovertebral joint while sufficiently decompressing the neural foramen.

Pharmacologic Inhibition of HIF-1α Attenuates Radiation-Induced Pulmonary Fibrosis in a Preclinical Image Guided Radiation Therapy.

PURPOSE: Radiation-induced pulmonary fibrosis (RIPF) is a long-term side effect of thoracic radiation therapy. Hypoxia-induced vascular endothelial mesenchymal transition (EndMT) can occur during the development of RIPF. Here, we examined the direct contribution of endothelial HIF-1α (EC-HIF1α) on RIPF. METHODS AND MATERIALS: An inducible Cre-lox-mediated endothelial Hif1a deletion mouse line was used to evaluate the potential of HIF-1α inhibition to suppress RIPF. To evaluate the effects of a pharmacologic HIF-1α inhibitor on RIPF after image guided radiation therapy (IGRT) for spontaneous lung adenocarcinoma, we generated conditional tdTomato; K-RasG12D; and p53 flox/flox mice to facilitate tracking of tumor cells expressing tdTomato. RESULTS: We found that vascular endothelial-specific HIF-1α deletion shortly before radiation therapy inhibited the progression of RIPF along with reduced EndMT, whereas prolonged deletion of endothelial HIF-1α before irradiation did not. Moreover, we revealed that postirradiation treatment with the novel HIF-1α inhibitor, 2-methoxyestradiol (2-ME) could efficiently inhibit RIPF and EndMT. In addition, IGRT using primary mouse models of non-small cell lung cancer showed that combined treatment of 2-ME with ablative high-dose radiation therapy efficiently inhibited RIPF and the growth of both multifocal and single tumors, concomitantly reducing radiation-induced EndMT of normal as well as tumor regions. CONCLUSION: These results suggest that a negative regulator of HIF-1α-mediated EndMT, such as 2-ME, may serve as a promising inhibitor of RIPF in radiation therapy.

Free-Hand Cervical Pedicle Screw Placement by Using Para-articular Minilaminotomy: Its Feasibility and Novice Neurosurgeons' Experience.

STUDY DESIGN.: Retrospective study. OBJECTIVE.: Cervical pedicle screw (CPS) placement is technically demanding because of the great variation in pedicle size, dimension, and angulations between cervical levels and patients and the lack of anatomical landmarks. This retrospective study was conducted to analyze novice neurosurgeons' experience of CPS placement by using the technique with direct exposure of pedicle via para-articular minilaminotomy. METHODS.: We retrospectively reviewed 78 CPSs in 22 consecutive patients performed by 2 surgeons. All pedicle screws were inserted under the direct visualization of the pedicle by using para-articular minilaminotomy without any fluoroscopic guidance. We analyzed the direction and grade of pedicle perforation on the postoperative computed tomography scan. The degree of perforation was classified as grade 0 to 3. Grades 0 and 1 were classified as the correct position and the others, as the incorrect position. RESULTS.: In total, the correct position (grade 0 and 1) was found in 72 (92.3%) screws and the incorrect position (grade 2 and 3) in 6 (7.7%). Among the 16 pedicle perforations (grade 1, 2, and 3 perforations), the directions were lateral in 15 (93.8%) and superior in 1 (6.2%). There were no neurovascular complications related to CPS insertion. CONCLUSION.: Free-hand CPS placement by using para-articular minilaminotomy seems to be feasible and reproducible.

Performance of an impedance-variable pulsed high-power electron-beam accelerator based on energy efficient transmission.

Versatile high-power pulsed electron-beam accelerators that meet the requirements of pulsed high-power specifications are needed for appropriate applications in medical industry, defense, and other industries. The pulsed electron beam accelerator comprising a Marx generator and Blumlein pulse forming line (PFL) is designed to accelerate the electron beams at the level of 1 MeV when electrostatically discharging. The performance specifications of Marx generators consisting of a 100 kV DC power supply, R-L-C circuit, and high voltage switch are at a maximum 800 kV. At this time, by using the capacitance mismatching principle between the Marx generator and the Blumlein PFL under the law of preserving the amount of charge, it is possible to generate a high voltage in the form of a square pulse up to about 1.1 MV, as much as 1.37 times the charged voltage of the Marx generator. As a result, energy transmission from the Marx generator with a high efficiency of about 85% to the Blumlein PFL is possible. The aim of this study is that the pulsed high-power electron-beam accelerator can be used to change the diode impedance, and the energy of the accelerated electron beam reaches a level of 1 MeV with the square pulse width of about 100 ns at the flat-top in the range of relativistic electron beam generation. Performance tests were securely carried out by installing a dummy load based on CuSO4 solution varying the diode impedance to deter damage to the circuit by preventing reflected waves from being generated in the load.

Relationship between arterial stiffness and variability of home blood pressure monitoring.

Variability of blood pressure (BP) is known as a prognostic value for the subsequent target organ damage in hypertensive patients. Arterial stiffness is a risk factor for cardiovascular morbidity and mortality. The relationship between the arterial stiffness and the BP variability has been controversial. The objective of the present study was to investigate the relationship between arterial stiffness and home BP variability in patients with high normal BP and new onset hypertension (HTN).Four hundred sixty three patients (252 males, 49 ±â€Š12 year-old) with high normal BP or HTN were enrolled. Using radial applanation tonometry, pulse wave analysis (PWA) was performed for evaluation of systemic arterial stiffness. All patients underwent both home BP monitoring (HBPM) and PWA. Home BP variability was calculated as the standard deviation (SD) of 7 measurements of HBPM. Multiple linear regression analysis was performed to estimate and test the independent effects of home BP variability on the arterial stiffness.Mutivariate analysis showed that both systolic and diastolic morning BP variabilities were correlated with arterial stiffness expressed as augmentation pressure (AP, ß-coefficient = 1.622, P = .01 and ß-coefficient = 1.07, P = .035). The SDs of systolic and diastolic BP of evening were also associated with AP (ß-coefficient = 1.843, P = .001 and ß-coefficient = 1.088, P = .036). The SDs of morning and evening systolic BP were associated with augmentation index (AI, ß-coefficient = 1.583, P = .02 and ß-coefficient = 1.792, P = .001) and heart rate (75 bpm) adjusted AI (ß-coefficient = 1.592, P = .001 and ß-coefficient = 1.792, P = .001).In present study, the variability of systolic BP was closely related with arterial stiffness. The home BP variability might be important indicator of arterial stiffness.

Evaluation of Anti-Tumor Effects of Whole-Body Low-Dose Irradiation in Metastatic Mouse Models.

Low-dose irradiation (LDI) has recently been shown to have various beneficial effects on human health, such as on cellular metabolic activities, DNA repair, antioxidant activity, homeostasis potency, and immune activation. Although studies on the immunogenic effects of LDI are rapidly accumulating, clinical trials for cancer treatment are considered premature owing to the lack of available preclinical results and protocols. Here, we aim to investigate anti-tumor and anti-metastatic effects of whole-body LDI in several tumor-bearing mouse models. Mice were exposed to single or fractionated whole-body LDI prior to tumor transplantation, and tumor growth and metastatic potential were determined, along with analysis of immune cell populations and expression of epithelial-mesenchymal transition (EMT) markers. Whole-body fractionated-LDI decreased tumor development and lung metastasis not only by infiltration of CD4+, CD8+ T-cells, and dendritic cells (DCs) but also by attenuating EMT. Moreover, a combination of whole-body LDI with localized high-dose radiation therapy reduced the non-irradiated abscopal tumor growth and increased infiltration of effector T cells and DCs. Therefore, whole-body LDI in combination with high-dose radiation therapy could be a potential therapeutic strategy for treating cancer.

Aspirin and the risk of hepatocellular carcinoma development in patients with alcoholic cirrhosis.

Aspirin therapy has shown protective effects against hepatocellular carcinoma (HCC) in preclinical studies. However, it is unclear whether aspirin therapy lowers the risk of HCC in patients with alcoholic cirrhosis.A retrospective analysis of data from 949 consecutive patients with alcoholic cirrhosis who abstained from alcoholic drinking was performed. The primary and secondary outcomes were development of HCC and gastrointestinal bleeding events, respectively. Risk was compared between patients with aspirin treatment and patients who were not treated (non-aspirin group) using a time-varying Cox proportional hazards model for total population and propensity score-matching analysis.The aspirin group included 224 patients and the non-aspirin group had 725 patients. During the study period of median duration of 3.1 years, 133 patients (13.6%) developed HCC. In time-varying Cox proportional analyses, the aspirin group showed a significantly lower risk of HCC (adjusted hazard ratio [aHR]: 0.13; 95% confidence interval [CI]: 0.08-0.21; P < .001). In propensity score-matched pairs, aspirin therapy significantly reduced the risk of HCC (aHR: 0.14; 95% CI: 0.09-0.22; P < .001). In bleeding risk, treatment with aspirin alone was not significantly associated with a higher bleeding risk (aHR: 0.81; 95% CI: 0.45-1.44; P = .46).Aspirin therapy was associated with the lower risk of HCC in patients with alcoholic cirrhosis.

Trans-sacral epiduroscopic laser decompression versus the microscopic open interlaminar approach for L5-S1 disc herniation.

Context/Objective: Trans-sacral epiduroscopic laser decompression (SELD) is an alternative to microscopic open lumbar discectomy (OLD). SELD and OLD for L5-S1 lumbar disc herniation (LDH) have not been compared. We compared clinical results, including pain control, between SELD and OLD.Design: Retrospective analysis.Setting: Korean hospital.Participants: Eighty patients treated with SELD (n = 40) or microscopic OLD (n = 40) for L5-S1 LDH.Interventions: N/A.Outcome Measures: Clinical data were compared over 6 months. Functional status was evaluated using Oswestry Disability Index (ODI, 0-100%) and time to return to work. Preoperative and postoperative pain was measured using a visual analog scale (VAS, 0-10). Radiological assessment was performed preoperatively and postoperatively.Results: The ODI and VAS scores for leg and back pain significantly improved in both groups. At 6-months after the procedure, the average ODI decreased to 13.2 ± 11.2 from 54.5 ± 14.5 for SELD and 9.5 ± 10.4 from 57.5 ± 16.0 for OLD. The average leg VAS decreased to 1.9 ± 1.2 from 6.0 ± 1.4 for SELD and 2.3 ± 1.3 from 6.7 ± 1.6 for OLD. Back VAS reduced to 2.6 ± 1.3 from 7.2 ± 1.5 for OLD. Time to return to work was 1.1 ± 1.1 weeks for SELD and 5.4 ± 2.1 weeks for OLD. Clinical outcomes of SELD were non-inferior to those of OLD in terms of pain control.Conclusion: A scar-free procedure and early return to normal life are advantages of SELD.

Early Surgery or Conservative Care for Asymptomatic Aortic Stenosis.

BACKGROUND: The timing and indications for surgical intervention in asymptomatic patients with severe aortic stenosis remain controversial. METHODS: In a multicenter trial, we randomly assigned 145 asymptomatic patients with very severe aortic stenosis (defined as an aortic-valve area of ≤0.75 cm2 with either an aortic jet velocity of ≥4.5 m per second or a mean transaortic gradient of ≥50 mm Hg) to early surgery or to conservative care according to the recommendations of current guidelines. The primary end point was a composite of death during or within 30 days after surgery (often called operative mortality) or death from cardiovascular causes during the entire follow-up period. The major secondary end point was death from any cause during follow-up. RESULTS: In the early-surgery group, 69 of 73 patients (95%) underwent surgery within 2 months after randomization, and there was no operative mortality. In an intention-to-treat analysis, a primary end-point event occurred in 1 patient in the early-surgery group (1%) and in 11 of 72 patients in the conservative-care group (15%) (hazard ratio, 0.09; 95% confidence interval [CI], 0.01 to 0.67; P = 0.003). Death from any cause occurred in 5 patients in the early-surgery group (7%) and in 15 patients in the conservative-care group (21%) (hazard ratio, 0.33; 95% CI, 0.12 to 0.90). In the conservative-care group, the cumulative incidence of sudden death was 4% at 4 years and 14% at 8 years. CONCLUSIONS: Among asymptomatic patients with very severe aortic stenosis, the incidence of the composite of operative mortality or death from cardiovascular causes during the follow-up period was significantly lower among those who underwent early aortic-valve replacement surgery than among those who received conservative care. (Funded by the Korean Institute of Medicine; RECOVERY ClinicalTrials.gov number, NCT01161732.).

The Role of Built Environment on Health of Older Adults in Korea: Obesity and Gender Differences.

This study examines the effect of the built environment on obesity in older adults, taking into consideration gender difference. In this regard, we ask two questions: (1) How does the built environment affect obesity in older adults? (2) Is there a gender difference in the effect of the built environment? To examine the research questions, this study uses the 2015 Korean National Health and Nutrition Survey and geographically weighted regression (GWR) analysis. The empirical analyses show that environmental factors have stronger effects on local obesity rates for older men than for older women, which indicates a gender difference in obesity. Based on these findings, we suggest that public health policies for obesity should consider the built environment as well as gender difference.