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Interstitial cystitis/bladder pain syndrome (IC/BPS) has a negative impact on quality of life. We compared health-related quality of life (HRQoL) of patients with IC/BPS with patients having other diseases using the EuroQol five-dimension (EQ-5D) and evaluated whether the HRQoL is improved after surgery.We compared EQ-5D of patients with Hunner lesion type IC/BPS with patients who had other diseases that cause chronic and severe pain including arthritis and cancer from a cross-sectional analysis of responses to the 2012-2016 Korea National Health and Nutrition Examination Survey. Changes in EQ-5D after transurethral coagulation (TUC) or resection (TUR) were measured in the IC/BPS participants.Compared to the EQ-5D index of normal population, patients with arthritis, cancer and IC/BPS had - 0.07 (95% CI - 0.07, - 0.06), - 0.01 (95% CI - 0.02, - 0.01), and - 0.21 (95% CI - 0.23, - 0.20) lower scores, respectively. Patients with IC/BPS were 35.9, 9.24, and 9.05 times more likely to have "extreme problem" in pain/discomfort, anxiety/depression, and usual activities EQ-5D domains, respectively, than patients without arthritis/cancer. After TUC or TUR, EQ-5D index was 0.90 in the TUC group and 0.92 in the TUR group.IC/BPS patients have worse HRQoL than healthy individuals. However, after surgical treatment, HRQoL is restored to a level close to normal.

Propensity score matching (PSM) is one of the most widely-used causal inference methods to estimate the causal estimands such as average treatment effect or average treatment effect on the treated from observational studies. To implement PSM, a researcher first selects an appropriate set of confounders, estimates the propensity score, and matches the treated group with the control group using a matching algorithm such as nearest neighborhood or optimal matching. In this paper, we highlight the importance of investigating the assumptions employed in the PSM procedure thoroughly because they strongly affect the analysis result, but are not testable using observational data. We explain how to exploit the domain knowledge to avoid the potential risks from the violation of the untestable assumptions, and show how the research purpose is linked to selecting the matching algorithm and downstream analysis after PSM. In addition, to examine the vulnerability of the causal result, we highlight the use of sensitivity analysis for the analysis after PSM. These points are demonstrated in detail using National Supported Work data.

Purpose: We compared success rates of 3 surgical techniques (holmium laser enucleation of the prostate [HoLEP], transurethral resection of the prostate [TURP], and photoselective laser vaporization prostatectomy [PVP]) for treatment of benign prostatic obstruction (BPO). We aimed to identify preoperative clinical variables and urodynamic parameters that predict surgical success.Methods: A total of 483 patients who underwent surgical treatment for BPO at Samsung Medical Center between 2006 and 2017 were retrospectively analyzed; of these 361, 81, and 41 patients underwent HoLEP, TURP, and PVP, respectively. Prostate-specific antigen, prostate volume, urodynamic parameters, and International Prostate Symptom Score (IPSS)/quality of life (QoL) index were evaluated preoperatively; uroflowmetry, postvoid residual urine, and IPSS/QoL index were measured 6 months postoperatively. Surgical success was defined based on IPSS, maximum flow rate, and QoL index and predictive factors were identified using multiple logistic regression analyses.Results: Success rates of HoLEP, TURP, and PVP were 67.6%, 65.4%, and 34.1%, respectively, and the HoLEP and TURP groups were not significantly different. Regression analysis revealed prostate volume ≥50 mL and bladder outlet obstruction index (BOOI) ≥40 to be independent factors predicting HoLEP success. Only high preoperative QoL could predict the success of TURP, whereas other urodynamic parameters remained unrelated.Conclusions: Patients treated with HoLEP and TURP displayed equivalent efficacies, but PVP was relatively less efficient than both. Preoperative variables of prostate volume ≥50 mL and BOOI ≥40 were independent predictive factors for the success of HoLEP but not of TURP.

The Korean Institute of Technology Satellite (KITSAT-1) is the first satellite developed by the Satellite Technology Research Center and the University of Surrey. KITSAT-1 is orbiting the Earth’s orbit as space debris with a 1,320 km altitude after the planned mission. Due to its relatively small size and altitude, tracking the KITSAT-1 was a difficult task. In this research, we analyzed the tracking results of KITSAT-1 for one year using the Midland Space Radar (MSR) in Texas and the Poker Flat Incoherent Scatter Radar (PFISR) in Alaska operated by LeoLabs, Inc. The tracking results were analyzed on a weekly basis for MSR and PFISR. The observation was conducted by using both stations at an average frequency of 10 times per week. The overall corrected range measurements for MSR and PFISR by LeoLabs were under 50 m and 25 m, respectively. The ionospheric delay, the dominant error source, was confirmed with the International Reference of Ionosphere-16 model and Global Navigation Satellite System data. The weekly basis orbit determination results were compared with two-line element data. The comparison results were used to confirm the orbital consistency of the estimated orbits.

This study is to evaluate a novel Quantum Molecular Resonance energy device as a laparoscopic bipolar vessel sealer. The majority of conventional bipolar energy-based vessel sealing devices utilize energy at frequencies between 300 kHz and 500 kHz. The use of such frequencies has disadvantages including unintended damage to surrounding tissues and excessive surgical smoke production. Here, we developed a bipolar energy source using Quantum Molecular Resonance (QMR) energy of 4–64 MHz and combined this into a laparoscopic vessel sealer. We investigate the microscopic tissue effect and surgeon’s experiences of the laparoscopic bipolar vessel sealer using a novel QMR energy source through animal experiments. QMR energy sources showed higher sealing success rates (100% vs. 66.7%) and a higher burst pressure (963 mmHg vs. 802 mmHg) of the sealed vessels compared to LigaSure™. Histological analysis showed less vessel wall injury in the QMR energy source (55.0% vs. 73.9%). In the laparoscopic setting experiments, compared to LigaSure™, QMR energy sources showed statistically significantly less smoke formation (p = 0.014), less tissue carbonization (p = 0.013), and less stickiness (p = 0.044) during sealing tissues. A novel QMR energy source for a laparoscopic bipolar vessel sealer could produce a better sealing performance and less surrounding tissue damage.

Jiwoong Yu, Youngjun Boo, Minyong Kang, Hyun Hwan Sung, Byong Chang Jeong, Seongil Seo, Seong soo Jeon, Hyunmoo Lee, Hwang Gyun Jeon Department of Urology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of KoreaCorrespondence: Hwang Gyun JeonDepartment of Urology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-Ro, Gangnam-Gu, Seoul, 06351, Republic of KoreaTel +82-2-2148-9599Fax +82-2-3410-6992Email hwanggyun.jeon@samsung.comPurpose: We evaluated the negative predictive value (NPV) of multiparametric magnetic resonance imaging (mpMRI) in detecting clinically significant prostate cancer (csPCa) according to biopsy setting and prostate-specific antigen density (PSAD) using transperineal template-guided saturation prostate biopsy (TPB) as the reference standard.Methods: A total of 161 patients with biopsy histories and negative pre-biopsy mpMRI (Prostate Imaging Reporting and Data System version 2 scores of less than 3) participated in the study. TPB was performed on the following indications: “prior negative biopsy” in patients with persistent suspicion of prostate cancer (n = 91) or “confirmatory biopsy” in patients who were candidates for active surveillance (n = 70). The csPCa was defined as a Gleason score of 3 + 4 or greater. We calculated the NPV of mpMRI in detecting csPCa according to biopsy history and prostate-specific antigen density (PSAD) and conducted a logistic regression analysis to determine the clinical predicator for the absence of csPCa.Results: The detection rate of csPCa was 5.5% in the prior negative biopsy group and 14.3% in the confirmatory biopsy group (P = 0.057). None of the variables in the logistic regression models including PSAD < 0.15 ng/mL/cc and prior negative biopsy could predict the absence of csPCa. The NPV of mpMRI in detecting csPCa in patients with a prior negative biopsy worsen from 94.5% to 93.3% when combined with PSAD < 0.15 ng/mL/cc.Conclusion: Patients with negative mpMRI findings may not omit repeat biopsy even if their prior biopsy histories are negative and PSADs are < 0.15 ng/mL/cc.Keywords: early detection of cancer, prostatic neoplasm, prostate-specific antigen density, magnetic resonance imaging, negative predictive value, transperineal prostate biopsy

Jiwoong Yu, Chung Un Lee, Minyong Kang, Hwang Gyun Jeon, Byong Chang Jeong, Seong Il Seo, Seong Soo Jeon, Hyun Moo Lee, Hyun Hwan Sung Department of Urology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea Purpose: We investigated to determine if there is an increased rate of urothelial carcinoma (UC) in kidney transplant (KT) recipients and to compare oncological outcomes of UC in KT recipients with non-KT patients.Patients and methods: Among 2,186 patients who underwent KT in our institute, nine patients developed UC after KT in our center. Age-standardized rates (ASRs) were calculated to compare incidence rates of UC between KT patients and the general population. Additional five patients who underwent KT at other hospitals and received UC treatment at our center were included, thus a total of 14 KT patients were compared with non-KT patients in the aspect of the treatment outcomes of bladder cancer and upper urinary tract UC (UTUC) by using generalized estimating equation (GEE).Results: The ASRs of bladder cancer and UTUC in KT recipients were 25.5 and 129.5 times higher than that of the general population. Although there was no difference in bladder cancer-specific survival rates (P-value 0.1186), however, progression rates of bladder cancer were significantly higher in KT recipients with a relative risk of 10.53 (P-value 0.0481). There was no significant difference in UTUC recurrence, progression, and specific survival rate (P-values 0.8915, 0.8806, and 0.8116, respectively).Conclusion: Incidence of UC was much higher in KT recipients than the general population. Treatment outcomes for UC in KT recipients were not inferior to those of non-KT patients, except for the progression of bladder cancer. Special attention should be paid to screening and treatment of UC in KT recipients. Keywords: urothelial carcinoma, kidney transplantation, bladder cancer, upper urinary tract urothelial carcinoma

We aimed to evaluate the detection rates of prostate cancer (PCa) and clinically significant PCa (csPCa) using magnetic resonance imaging-targeted biopsy (MRI-TBx) in men with low prostate-specific antigen (PSA) levels (2.5–4.0 ng/mL). Clinicopathologic data of 5502 men with PSA levels of 2.5–10.0 ng/mL who underwent transrectal ultrasound-guided biopsy (TRUS-Bx) or MRI-TBx were reviewed. Participants were divided into four groups: LP-T [low PSA (2.5–4.0 ng/mL) and TRUS-Bx, n = 2018], LP-M (low PSA and MRI-TBx, n = 186), HP-T [high PSA (4.0–10.0 ng/mL) and TRUS-Bx, n = 2953], and HP-M (high PSA and MRI-TBx, n = 345). The detection rates of PCa and csPCa between groups were compared, and association of biopsy modality with detection of PCa and csPCa in men with low PSA levels were analyzed. The detection rates of PCa (20.0% vs. 38.2%; P P P = 0.263) and csPCa (32.3% vs. 39.4%; P = 0.103) between the LP-M and HP-M groups. Multivariate analyses revealed that using MRI-TBx could predict the detection of csPCa (odds ratio 2.872; 95% confidence interval 1.996‒4.132; P

Recently, the number of space objects has increased exponentially leading to a possibility of an increase in the number of space hazards; therefore, the Space Situational Awareness Program based on radars is currently being developed to counteract these events. The Korea Space Surveillance Active Phased Array Radar Window (KOSPAW) test bed is being developed to test radar technology in a phased array and detect radar cross section (RCS) of 5 m2 for space objects at an altitude of 750 km. The designed radar can effectively operate in tracking and searching modes. This paper describes the results of the operational test of a KOSPAW to verify the sensitivity of space objects in the characteristics of the satellite catalogs and relative range and velocity from the propagated orbits of the TLE. In this study, methods, such as increasing the number of arrays and the transmission power, to improve the number of space objects detected are proposed, and the number of predicted space objects is confirmed. In addition, design improvements are made and the operating modes are simulated. The KOSAPW test bed will be tested in 2023 by technically verifying the accessibility of its components.

Background: The majority of conventional bipolar energy-based vessel sealing devices utilize energy at frequencies between 300 kHz and 500 kHz. The use of such frequencies has the disadvantages including unintended damage to surrounding tissues and excessive surgical smoke production. Here, we developed an bipolar energy source using Quantum Molecular Resonance (QMR) energy of 4–64 MHz and combined this into a laparoscopic vessel sealer. We investigate the microscopic tissue effect and surgeon's experiences of laparoscopic bipolar vessel sealer using a novel QMR energy source through animal experiments. Results: In an open surgical setting, QMR energy sources showed higher sealing success rates (100% vs. 66.7%) and higher burst pressure (963 mmHg vs. 802mmHg) of the sealed vessels compared to LigaSure™. Histological analysis showed less vessel wall injury in the QMR energy source (55.0% vs. 73.9%). In the laparoscopic setting experiments, compared to LigaSure™, QMR energy sources showed statistically significantly less smoke formation (p = 0.014), less tissue carbonization (p = 0.013), and less stickiness (p = 0.044) during sealing tissues. Conclusions: Novel QMR energy source for laparoscopic bipolar vessel sealer could produce better sealing performance and less surrounding tissue damage compared to the conventional devices. Laparoscopic surgery using QMR energy sources showed better surgeon's experiences in terms of surgical smoke formation, tissue carbonization, and stickiness.

Background To evaluate the strategy for detection of prostate cancer (PCa) with low prostate specific antigen (PSA) level (2.5–4.0 ng/mL), prostate biopsy patients with low PSA were assessed. We evaluated the risk of low PSA PCa and the strategy for screening low-PSA patients. Methods We retrospectively analyzed the patients who underwent prostate biopsy with low PSA level. Baseline characteristics, PSA level before prostate biopsy, prostate volume, prostate specific antigen density (PSAD), and pathological data were assessed. Results Among the 1986 patients, 24.97% were diagnosed with PCa. The PSAD was 0.12 ± 0.04 ng/mL2 in the PCa-diagnosed group and 0.10 ± 0.04 ng/mL2 in non-cancer-diagnosed group (P < 0.001). Of the 496 patients diagnosed with PCa, 302 (60.89%) were in the intermediate- or high-risk group. PSAD was 0.13 ± 0.04 ng/mL2 in the intermediate- or high-risk group and 0.11 ± 0.03 ng/mL2 in the very low- and low-risk group (P < 0.001). Of 330 patients who underwent radical prostatectomy, 85.15% were diagnosed as having significant cancer. There was significant correlation between PSAD and PCa (r = 0.294, P < 0.001). PSAD with a specificity of 80.00% of a clinically significant cancer diagnosis was assessed at 0.1226 ng/mL2. Conclusion The PCa detection rate in the low-PSA group was not lower than that of previous studies of patients with PSA from 4.0 to 10.0 ng/mL. Further, it may be helpful to define a strategy for PCa detection using PSAD in the low-PSA group., Graphical Abstract

Wan Song,1 Ji Woong Yu,2 Byong Chang Jeong,2 Seong Il Seo,2 Seong Soo Jeon,2 Hyun Moo Lee,2 Han Yong Choi,3 Eun-Suk Kang,4 Hwang Gyun Jeon2 1Department of Urology, Ewha Womans University School of Medicine, Seoul, Korea; 2Department of Urology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea; 3Department of Urology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea; 4Department of Laboratory Medicine and Genetics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea Purpose: To investigate the clinical usefulness of natural killer cell activity (NKA) for detection of prostate cancer (PCa) and prediction of Gleason grade. Patients and methods: We prospectively enrolled 221 patients who underwent transrectal ultrasound-guided prostate biopsy for suspected PCa due to elevated prostate-specific antigen (PSA) >2.5ng/mL or abnormal findings on digital rectal examination (n=146), or who were diagnosed with PCa (n=75) between 2016 and 2017. The NKA was compared according to PCa and Gleason grade. Correlation analysis was used to evaluate associations among NKA, PCa, and Gleason grade, and expressed using distribution dot plots. The absolute risk and relative risk of PCa, and odds ratios at different cut-off values of NKA were calculated. Results: Of the total 221 patients, PCa was identified in 135 (61.9%) patients. When patients were divided according to PCa, there was no significant difference in NKA (1,267.6 vs 1,198.9pg/mL, P=0.491). Furthermore, in 135 patients with PCa, the NKA was not significantly different according to Gleason grade (P=0.893). These results were not changed when confined to the patients with PSA between 2.5 and 10.0ng/mL (P=0.654 and P=0.672, respectively). In addition, there was no significant difference in the risk of PCa at different cut-off values of NKA. Conclusion: These results indicate that NKA does not appear to be very useful for detection of PCa and prediction of Gleason grade. Further large multi-institutional studies are required to verify the role of NKA in PCa detection and Gleason grade prediction. Keywords: immunosurveillance, natural killer cell activity, prostate cancer, Gleason score

In this letter, we propose a method for estimating the center of rotation on an experimental radar imaging. The experiment is performed with tomographic approach to obtain the radar cross section images of the target on a rotation table. In an ultrahigh-resolution imaging using tomographic reconstruction, precise knowledge of rotation center of the turntable position is necessary since this has a big influence on the image quality. The position of rotation center can be physically measured, but the result is not accurate due to the delay introduced by the RF components and cables. Thus, we present a method to precisely determine the rotation center based on the rotational symmetry of the received data. The proposed method is verified by doing imaging of several targets using ultrawideband radar with picosecond-length pulses. The system bandwidth is larger than 30 GHz, and the imaging results have subcentimeter resolution.

Summary Objective To describe our experience with pneumovesicoscopic bladder tumor resection in a young boy whose urethra was too small to use a resectoscope. Methods An 11-year-old boy presented with gross hematuria. The patient was found to have a 2 cm-sized bladder tumor on ultrasound. The patient’s urethra was too small to use a pediatric resectoscope, making it impossible to perform a transurethral resection of the bladder tumor. Therefore, pneumovesicoscopic bladder tumor resection was performed. En-bloc resection was performed successfully using 3 mm laparoscopic instruments, and the tumor was safely retrieved within an endo-bag made with a surgical glove. Results On postoperative day 1, the Foley catheter was removed and the patient was discharged. The pathology report described bladder papillary urothelial carcinoma, grade II/III without lamina propria invasion. The patient underwent follow-up with ultrasonography and urine cytology every three to six months. There was no recurrence for 21 months after surgery. Conclusion This video demonstrates a pneumovesicoscopic approach for the treatment of bladder tumor in a young patient whose urethra was too small to use a resectoscope. Pneumovesicoscopic bladder tumor resection is technically feasible and safe.

INTRODUCTION AND OBJECTIVES:To compare and analyze surgical, oncological and functional outcomes of transperitoneal robotic partial nephrectomy (TRPN) and retroperitoneal RPN (RRPN).METHODS:Out of ...

Background Pathological features of prostate cancer in Korean men were analyzed to determine whether identification of tumor volume, Gleason score (GS), focality, and location using radical prostatectomy (RP) specimens can provide useful information for the application of focal therapy (hemiablation). Methods From January 2016 to December 2017, 913 patients who underwent RP at a single center were selected for analysis. Patients with prostate-specific antigen levels > 15 ng/mL or those who had received hormone therapy prior to surgery were excluded. Preoperative data and the number, volume, location, and GS of each tumor were recorded. Results Overall, 762 RP specimens were examined, and 1448 tumors were identified. The majority of the cases were multifocal (60.5%) and bilateral (82%) in nature. Among the 686 secondary tumors, 250 (36.4%) had a GS ≥7 and 122 (17.8%) had a tumor volume ≥ 0.5 mL. Among the 435 bilateral multifocal cases, secondary tumors on the lobes contralateral to the largest tumor were significant by volume (≥0.5 mL) in 91 (20.9%) cases and by grade (GS ≥7) in 179 (41.1%) cases. There were 102 (23.4%) tumors with a small tumor volume (

Purpose To investigate germline and somatic mutation profiles in Korean patients with prostate cancer using liquid biopsy and solid tissue testing and to evaluate the prognostic value of circulating tumor DNA (ctDNA) in predicting castration resistance in patients with metastatic hormone-sensitive prostate cancer (mHSPC). Materials and Methods Plasma samples from 56 prostate cancer patients were subjected to next-generation sequencing (NGS) to identify germline mutations and ctDNA analysis using liquid biopsy to detect somatic mutations. Additionally, paired solid cancer tissues from 18 patients were subject to NGS to detect somatic mutations. The clinical parameters and ctDNA profiles of patients with mHSPC were analyzed to evaluate the prognostic value of ctDNA mutations with respect to predicting castration resistance using Cox proportional hazards regression analysis. Results Germline mutations occurred in 3.6% of the patients in this cohort, with mutations identified in RAD50 (1.8%) and BRCA1 (1.8%). Somatic mutations detected by liquid biopsy and solid tissue testing were common in TP53 (12.5%), PIK3CA (3.6%), and TMPRSS2-ERG (3.6%). Of the 18 patients with paired tissue testing, two patients had at least one identical somatic mutation in both the liquid biopsy and solid tissue testing. In patients with mHSPC, the presence of ctDNA mutations could independently predict the castration resistance development (hazard ratio, 13.048; 95% confidential interval, 1.109–153.505; p=0.041). Conclusions Korean patients with prostate cancer showed a relatively low germline mutation rate compared to other ethnicities. The ctDNA mutations detected by liquid biopsy can predict the development of castration resistance in patients with mHSPC., Graphical Abstract

Purpose: Active surveillance is now the treatment of choice in men with low risk prostate cancer. Although there is no consensus on which patients are eligible for active surveillance, prostate specific antigen above 10 ng/ml is generally excluded. In an attempt to determine the validity of using a prostate specific antigen cutoff of 10 ng/ml to counsel men considering active surveillance we analyzed a multi-institution database to determine the pathological outcome in men with prostate specific antigen greater than 10 ng/ml but histologically favorable risk prostate cancer.Materials and Methods: We queried a prospectively maintained database of men with histologically favorable risk prostate cancer who underwent radical prostatectomy between 2003 and 2015. The cohort was categorized into 3 groups based on prostate specific antigen level, including low—less than 10 ng/ml, intermediate—10 or greater to less than 20 and high—20 or greater. Associations of prostate specific antigen group with adverse patholo...

To evaluate focal therapy (hemiablation) eligibility in men undergoing prostate biopsy and multiparametric magnetic resonance imaging (mpMRI) with reference to histopathology from radical prostatectomy (RP) specimens. Subjects were selected among 810 men who underwent prostate biopsy, mpMRI, and RP from January 2016 to December 2017. Hemiablation eligibility criteria were biopsy-proven unilateral cancer, prostate-specific antigen ≤ 15 ng/ml, and Gleason score (GS) ≤ 3 + 4. Evidence of non-organ-confined disease or Prostate Imaging Reporting and Data System score ≥ 4 on the contralateral lobe on mpMRI was classified as ineligible for hemiablation. Of the 810, data for 185 who met the screening criteria were compared to final pathology findings. Significant cancer at RP was defined as any of the following: (1) GS 6 with tumor volume ≥ 0.5 ml; (2) GS ≥ 3 + 4; or (3) the presence of advanced stage (≥ pT3). Among the 185 candidates for hemiablation, 62 (33.5%) had unilateral cancer on final RP histopathology. Among the 123 bilateral cancers, 50 (27%) were organ confined and had GS ≤ 3 + 4 = 7 and bilateral multifocal tumor in which the index tumor was confined to one lobe and the secondary tumor in the contralateral lobe had tumor volume

OBJECTIVES To examine the prognostic role of the pretreatment aspartate transaminase/alanine transaminase or De Ritis ratio in patients with metastatic renal cell carcinoma receiving first-line systemic tyrosine kinase inhibitor therapy. METHODS We retrospectively searched the medical records of 579 patients with metastatic renal cell carcinoma who visited Samsung Medical Center, Seoul, Korea, from January 2001 through August 2016. After excluding 210 patients, we analyzed 360 patients who received first-line tyrosine kinase inhibitor therapy. Cancer-specific survival and overall survival were defined as the primary and secondary end-points, respectively. A multivariate Cox proportional hazards regression model was used to identify independent prognosticators of survival outcomes. RESULTS The overall population was divided into two groups according to the pretreatment De Ritis ratio as an optimal cut-off value of 1.2, which was determined by a time-dependent receiver operating characteristic curve analysis. Patients with a higher pretreatment De Ritis ratio (≥1.2) had worse cancer-specific survival and overall survival outcomes, compared with those with a lower De Ritis ratio (

A simple cost-effective technique of wideband grating-lobe (GL) suppression by rotation of the phased array antennas is developed for application in a system of low-frequency sparse aperture array (LF-SAA) antennas of the square kilometer array (SKA) radio-telescope. The technique implies using of equal sparse planar circular antennas with the well-tried square lattice (SqL) distribution of the station antenna array sensors, which is known as the best in terms of production costs and maintenance charges. The peak levels of residual GLs in the fringe pattern of most pairs of the rotated antenna array stations do not exceed value of $- \mathbf{17}\;\mathbf{dB}$ over frequencies ranged from 70 to 450 MHz in the case of uniform antenna array element weighting, whereas the maximum levels of residual GLs are reduced to $- \mathbf{25}\;\mathbf{dB}$ when the Hamming weight tapering is applied.

Ultra-high resolution (UHR) radar imaging is used to analyze the internal structure of objects and to identify and classify their shapes based on ultra-wideband (UWB) signals using a vector network analyzer (VNA). However, radar-based imaging is limited by microwave propagation effects, wave scattering, and transmit power, thus the received signals are inevitably weak and noisy. To overcome this problem, the radar may be operated in the near-field. The focusing of UHR radar signals over a close distance requires precise geometry in order to accommodate the spherical waves. In this paper, a geometric estimation and compensation method that is based on the minimum entropy of radar images with sub-centimeter resolution is proposed and implemented. Inverse synthetic aperture radar (ISAR) imaging is used because it is applicable to several fields, including medical- and security-related applications, and high quality images of various targets have been produced to verify the proposed method. For ISAR in the near-field, the compensation for the time delay depends on the distance from the center of rotation and the internal RF circuits and cables. Required parameters for the delay compensation algorithm that can be used to minimize the entropy of the radar images are determined so that acceptable results can be achieved. The processing speed can be enhanced by performing the calculations in the time domain without the phase values, which are removed after upsampling. For comparison, the parameters are also estimated by performing random sampling in the data set. Although the reduced data set contained only 5% of the observed angles, the parameter optimization method is shown to operate correctly.

In this paper, we present a novel signal processing method for video synthetic aperture radar (ViSAR) systems, which are suitable for operation in unmanned aerial vehicle (UAV) environments. The technique improves aspects of the system's performance, such as the frame rate and image size of the synthetic aperture radar (SAR) video. The new ViSAR system is based on a frequency-modulated continuous wave (FMCW) SAR structure that is combined with multiple-input multiple-output (MIMO) technology, and multi-channel azimuth processing techniques. FMCW technology is advantageous for use in low cost, small size, and lightweight systems, like small UAVs. MIMO technology is utilized for increasing the equivalent number of receiving channels in the azimuthal direction, and reducing aperture size. This effective increase is achieved using a co-array concept by means of beat frequency division (BFD) FMCW. A multi-channel azimuth processing technique is used for improving the frame rate and image size of SAR video, by suppressing the azimuth ambiguities in the receiving channels. This paper also provides analyses of the frame rate and image size of SAR video of ViSAR systems. The performance of the proposed system is evaluated using an exemplary system. The results of analyses are presented, and their validity is verified using numerical simulations.

Purpose: The current study is aimed to assess whether a longer duration of 5α-reductase inhibitor (5α-RI) exposure was asso-ciated with higher rate of permanent erectile dysfunction (ED) in a rat model. Materials and Methods: Male Sprague-Dawley rats (n=76) were assigned to five groups: (i) normal control group; (ii) dutaste-ride (0.5 mg/rat/d) for 4-weeks group; (iii) dutasteride for 4-weeks plus 2-weeks of resting group; (iv) dutasteride for 8-weeks group; and (v) dutasteride for 8-weeks plus 2-weeks of resting group. In vivo erectile responses to electrical stimulation, and changes of fibrotic factors and smooth muscle/collagen contents in the corpus cavernosum were evaluated in each group. Results: Dutasteride administration for 4 and 8 weeks significantly decreased erectile parameters compared with the control group. Reduced erectile responses were recovered during 2 weeks of drug-free time in the 4-week treatment group, but were not in the 8-week group. Protein levels of fibrosis-related factors transforming growth factor (TGF)-β1, TGF-β2, and p-Smad/Smad (Smad 2/3) in the corpus cavernosum showed no significant change after 4 weeks of dutasteride oral administration, but were enhanced after 8 weeks. Dutasteride markedly decreased smooth muscle content and increased collagen after 4 and 8 weeks of use, but no nuclear size changes; however, neither group showed significant improvement in the smooth muscle to collagen ratio after the rest period. Conclusions: Our study showed that recovery from ED depended on the duration of medication, and administration of dutas-teride for more than 8-weeks in rats could result in irreversible ED even after discontinuation of medication.

INTRODUCTION AND OBJECTIVES: Active surveillance (AS) is now the preferred treatment of choice in men with a low-risk prostate cancer. Although there is no consensus on patients who are eligible for AS, PSA above 10 ng/mL is generally excluded. In an attempt to determine the validity of using PSA cutoff of 10 in counseling men considering AS, we have analyzed a multi-institution database to determine the pathologic outcome in men with PSA greater than 10 but have a histologically favorable-risk prostate cancer. METHODS: Prospectively maintained database on men with histologically favorable risk prostate cancer but underwent radical prostatectomy between 2003 and 2015 were queried from three institutions. The cohort was categorized into three groups based on PSA levels: Low PSA (LP) (

An optical payload needs to be validated its image performance after launched into orbit. The image performance was validated by observing star because ground site contains uncertainties caused by atmosphere, time of the year, and weather. Time Delayed and Integration(TDI) technique, which is mostly used to observe the ground, is going to be used to observe the selected stars. A satellite attitude scenario was also developed to observe the selected stars. The scenario is created to enable TDI to operate. Rotation angles of optical payload are determined in order for the selected stars to properly be passed at a desired angular velocity about rotation axis. The result of this research can be utilized to validate the quality of optical payload of a satellite in orbit. In addition, a quaternion for pointing selected stars is calculated minimizing the path from a given arbitrary attitude of satellite.

A method of stellar source selection for validating the quality of image is investigated for a low Earth orbit optical remote sensing satellite. Image performance of the optical payload needs to be validated after its launch into orbit. The stellar sources are ideal source points that can be used to validate the quality of optical images. For the image validation, stellar sources should be the brightest as possible in the charge-coupled device dynamic range. The time delayed and integration technique, which is used to observe the ground, is also performed to observe the selected stars. The relations between the incident radiance at aperture and V magnitude of a star are established using Gunn & Stryker's star catalogue of spectrum. Applying this result, an appropriate image performance index is determined, and suitable stars and areas of the sky scene are selected for the optical payload on a remote sensing satellite to observe. The result of this research can be utilized to validate the quality of optical payload of a satellite in orbit.

In this paper, we describe a simple method for SAR image synthesis of a realistic target model using the general purpose EM simulator like FEKO and demonstrate the steps by processing the simulated SAR raw data with chirp-scaling algorithm (CSA), which is one of the most widely used SAR image formation algorithms. This method can benefit us many advantages like performance evaluation for target detection, estimation and target recognition with realistic target model in a cost-and-time effective way.

Appropriate patient selection for active surveillance is challenging.Our study of 217 patients demonstrated that the preoperative absolute neutrophil and lymphocyte counts were better predictors of aggressive oncologic features than were the neutrophil-to-lymphocyte ratio in the assessment of low-risk prostate cancer patients. Our findings suggest that routine hematologic workup could be used to further stratify low-risk prostate cancer patients.The neutrophil-to-lymphocyte ratio (NLR) has emerged as a ubiquitous prognostic biomarker in cancer-related inflammation, specifically in patients with metastatic castration-resistant prostate cancer (PCa). We evaluated the clinical utility of the preoperative NLR, absolute neutrophil count (ANC), and absolute lymphocyte count (ALC) as a risk stratification tool for patients with low-risk PCa.We identified 217 low-risk PCa patients with preoperative hematologic data who had met the criteria for active surveillance but had undergone robot-assisted radical prostatectomy at our institution from 2006 to 2015. Logistic regression models were constructed to determine whether the baseline NLR, ANC, and ALC were associated with upstaging, upgrading, and biochemical recurrence (BCR). Survival analyses were performed using the Kaplan-Meier method.On multivariate analysis, a higher prostate-specific antigen level (odds ratio [OR], 1.554; 95% confidence interval [CI], 1.148-2.104), a greater number of positive cores (OR, 2.098; 95% CI, 1.043-2.104), and a higher ALC (OR, 4.311; 95% CI, 1.258-14.770) were associated with upstaging. More importantly, the 5-year biochemical recurrence-free survival was significantly lower in the high ANC group (ANC4.0 × 10(9)/L) compared with that of the low ANC group (P = .011). The NLR was not associated with upstaging, upgrading, or BCR in our study cohort (P = .368, P = .573, and P = .504, respectively). The only significant association with upgrading was patient age (OR, 1.106; 95% CI, 1.043-1.173).NLR was not useful in predicting adverse pathologic outcomes in our patients with low-risk PCa. However, relative neutrophilia and lymphocytosis might indicate an early manifestation of harboring a more aggressive PCa.