101 research outputs found

    Integrated On-Silicon and On-glass Antennas for Mm-Wave Applications

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    The paper presents several integrated high frequency antenna prototypes based on Si/CMOS and on-glass technologies for millimeter-wave (mm-wave) applications. On-chip loop antenna and dipole radiator are presented. In addition, a wide-band dipole-patch antenna design for the range of 74 – 104 GHz is integrated into a CMOS chip with an on-chip pulse generator. In addition, an implementation of a fully on-Silicon antenna array integrated with a timed-array transmitter. To control the beam-forming of this array, a digital-based time adjustment circuit is integrated together with the antenna array. Simulated and measured data including return loss, and radiation patterns are presented. This paper also introduces an on-glass antenna prototypes fabricated on quartz substrate. The on-glass antenna is to demonstrate for handset or automobile’s windshield/windows applications where radio waves could be transmitted and received from various directions. The results show several compact antenna candidates integrated by both Silicon and quartz substrates towards mm-Wave/sub-mm-Wave sensing and communication applications

    Dynamical Modulation of Wintertime Synoptic-Scale Cyclone Activity over the Japan Sea due to Changbai Mountain in the Korean Peninsula

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    The dynamical impact of the Changbai Mountain Range in the Korean Peninsula on the extratropical cyclone activity over the Japan Sea in early winter is examined using the Weather Research Forecasting model. We have conducted two independent long-term integrations over 15 winter months (December only) from 2000 to 2014 with and without modified topography. The results show that the Changbai Mountain Range plays a vital role in increasing cyclone track frequency, low-level poleward eddy heat flux, and the local deepening rate over the Japan Sea through enhancement of the lower-tropospheric baroclinic zone (LTBZ). This mountain range gives rise to activation of the synoptic-scale cyclone activity over that region. From our case study on three typical cyclones, it is found that mesoscale structures in the vicinity of a cyclone’s center are dynamically modulated when it passes through the LTBZ and that cyclogenesis is triggered around that zone. A vorticity budget analysis shows that the stretching term relevant to enhanced low-level convergence plays a dominant role in intensifying cyclonic vorticities. We confirmed that the composite features of the three typical cases are consistent with the statistical ones of the dynamical modulation of the Changbai Mountain on synoptic-scale cyclone activity

    Optical study of charge instability in CeRu2Al10 in comparison with CeOs2Al10 and CeFe2Al10

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    The anisotropic electronic structure responsible for the antiferromagnetic transition in CeRu2Al10 at the unusually high temperature of T0=28 K was studied using optical conductivity spectra, Ce 3d x-ray photoemission spectra, and band calculation. It was found that the electronic structure in the ac plane is that of a Kondo semiconductor, whereas that along the b axis has a nesting below 32 K (slightly higher than T0). These characteristics are the same as those of CeOs2Al10 [ S. Kimura et al. Phys. Rev. Lett. 106 056404 (2011)]. The c-f hybridization intensities between the conduction and 4f electrons of CeRu2Al10 and CeOs2Al10 are weaker than that of CeFe2Al10, showing no magnetic ordering. These results suggest that the electronic structure with one-dimensional weak c-f hybridization along the b axis combined with two-dimensional strong hybridization in the ac plane causes charge-density wave (CDW) instability, and the CDW state then induces magnetic ordering

    Expression of nm23-H1 gene product in esophageal squamous cell carcinoma and its association with vessel invasion and survival

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    BACKGROUND: We assessed the nm23-H1 gene product expression and its relationship with lymphatic and blood vessel invasion in patients with esophageal squamous cell carcinoma. METHODS: Formalin-fixed and paraffin-embedded tissue sections from 45 patients who were treated surgically were used in this study. Pathologists graded lymphatic and blood vessel invasion in each of the tissue samples. Expression of nm23-Hl gene product was determined using a specific monoclonal antibody. RESULTS: Expression of nm23-H1 gene product was present in 17 (37.8%) cases. We found an inverse correlation between nm23-H1 gene product expression and lymphatic vessel invasion, whereas no correlation between nm23-H1 gene product expression and blood vessel invasion. Overall survival rate was not different between nm23-H1 gene product positive and negative patients (p = 0.21). However, reduced expression of nm23-H1 gene product was associated with shorter overall survival in patients with involved lymph nodes (p < 0.05), but not in patients without involved lymph nodes (p = 0.87). CONCLUSIONS: In patients with esophageal squamous cell carcinoma, there appears to be an inverse relationship between nm23-H1 gene product expression and lymphatic vessel invasion. Furthermore, nm23-H1 gene product expression might be a prognostic marker in patients with involved lymph nodes. Our data does not demonstrate any correlation between nm23-H1 gene product expression and blood vessel invasion

    Complications Associated With Spine Surgery in Patients Aged 80 Years or Older: Japan Association of Spine Surgeons with Ambition (JASA) Multicenter Study

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    Study Design:Retrospective study of registry data.Objectives:Aging of society and recent advances in surgical techniques and general anesthesia have increased the demand for spinal surgery in elderly patients. Many complications have been described in elderly patients, but a multicenter study of perioperative complications in spinal surgery in patients aged 80 years or older has not been reported. Therefore, the goal of the study was to analyze complications associated with spine surgery in patients aged 80 years or older with cervical, thoracic, or lumbar lesions.Methods:A multicenter study was performed in patients aged 80 years or older who underwent 262 spinal surgeries at 35 facilities. The frequency and severity of complications were examined for perioperative complications, including intraoperative and postoperative complications, and for major postoperative complications that were potentially life threatening, required reoperation in the perioperative period, or left a permanent injury.Results:Perioperative complications occurred in 75 of the 262 surgeries (29%) and 33 were major complications (13%). In multivariate logistic regression, age over 85 years (hazard ratio [HR] = 1.007, P = 0.025) and estimated blood loss ≥500 g (HR = 3.076, P = .004) were significantly associated with perioperative complications, and an operative time ≥180 min (HR = 2.78, P = .007) was significantly associated with major complications.Conclusions:Elderly patients aged 80 years or older with comorbidities are at higher risk for complications. Increased surgical invasion, and particularly a long operative time, can cause serious complications that may be life threatening. Therefore, careful decisions are required with regard to the surgical indication and procedure in elderly patients

    Risk Factors for Delirium After Spine Surgery in Extremely Elderly Patients Aged 80 Years or Older and Review of the Literature: Japan Association of Spine Surgeons with Ambition Multicenter Study

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    Study Design:Retrospective database analysis.Objective:Spine surgeries in elderly patients have increased in recent years due to aging of society and recent advances in surgical techniques, and postoperative complications have become more of a concern. Postoperative delirium is a common complication in elderly patients that impairs recovery and increases morbidity and mortality. The objective of the study was to analyze postoperative delirium associated with spine surgery in patients aged 80 years or older with cervical, thoracic, and lumbar lesions.Methods:A retrospective multicenter study was performed in 262 patients 80 years of age or older who underwent spine surgeries at 35 facilities. Postoperative complications, incidence of postoperative delirium, and hazard ratios of patient-specific and surgical risk factors were examined.Results:Postoperative complications occurred in 59 of the 262 spine surgeries (23%). Postoperative delirium was the most frequent complication, occurring in 15 of 262 patients (5.7%), and was significantly associated with hypertension, cerebrovascular disease, cervical lesion surgery, and greater estimated blood loss (P < .05). In multivariate logistic regression using perioperative factors, cervical lesion surgery (odds ratio = 4.27, P < .05) and estimated blood loss ≥300 mL (odds ratio = 4.52, P < .05) were significantly associated with postoperative delirium.Conclusions:Cervical lesion surgery and greater blood loss were perioperative risk factors for delirium in extremely elderly patients after spine surgery. Hypertension and cerebrovascular disease were significant risk factors for postoperative delirium, and careful management is required for patients with such risk factors
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