A complete low cost radon detection system Bayrak, A.; Barlas, E.; Emirhan, E. ...
Applied radiation and isotopes,
August 2013, 2013-Aug, 2013-8-00, 20130801, Volume:
78
Journal Article
Peer reviewed
Monitoring the 222Rn activity through the 1200km long Northern Anatolian fault line, for the purpose of earthquake precursory, requires large number of cost effective radon detectors. We have ...designed, produced and successfully tested a low cost radon detection system (a radon monitor). In the detector circuit of this monitor, First Sensor PS100-7-CER-2 windowless PIN photodiode and a custom made transempedence/shaping amplifier were used. In order to collect the naturally ionized radon progeny to the surface of the PIN photodiode, a potential of 3500V was applied between the conductive hemi-spherical shell and the PIN photodiode. In addition to the count rate of the radon progeny, absolute pressure, humidity and temperature were logged during the measurements. A GSM modem was integrated to the system for transferring the measurements from the remote locations to the data process center.
•Low cost radon detection.•Integrated GSM modem for early warning of radon anomalies.•Radon detection in environment .
Background
While preoperative chemotherapy for patients with stage II-III pancreatic adenocarcinoma (PDAC) is frequently practiced, its impact on very early PDAC (stage I) remains unclear today.
...Material and Methods
Patients undergoing pancreatectomy for PDAC between 2010 and 2016 were identified in the National Cancer Database. Early-stage patients (IA-IB) with complete oncologic and clinical information and more than 30-day survival were included. The effect of preoperative chemotherapy on margin status was assessed with binary logistic regression. Following correction for confounders, the effect of therapy sequencing was assessed via comparison of preoperative, postoperative, perioperative (pre- and post-operative) chemotherapy, and surgery only using Cox regression.
Results
Of 4785 patients, 688 (14.4%) were stage IA, and 4197 (87.7%) IB. The rate of preoperative chemotherapy was only 8.8%. Rate of margin positivity was lower for preoperative chemotherapy (12.3% vs 19.7%). After correcting for confounders, the risk of a positive margin was lower in preoperative chemotherapy (odd ratio OR 0.703,
p
= 0.042). Cox regression showed a significant overall survival advantage for preoperative (hazard ratio HR 0.784,
p
= 0.002), postoperative (HR 0.618,
p
< 0.001), and perioperative (HR 0.601,
p
< 0.001) chemotherapy compared with surgery alone. There was no significant difference in survival between chemotherapy groups but a trend towards optimal survival for preoperative chemotherapy.
Conclusion
Despite preoperative chemotherapy vs surgery alone resulting in improved R0 rates and overall survival even in stage I PDAC, it is rarely practiced. The results presented here suggest that preoperative chemotherapy should be strongly considered in all patients with resectable PDAC, including very early PDAC.
Background
The impact of lymph node (LN) status and lymphadenectomy (LA) on survival in pancreatic neuroendocrine tumors (pNETs) remains controversial. We evaluated the impact of tumor extension and ...grade on nodal metastasis and survival.
Methods
Surgical pNET patients were queried in the Surveillance Epidemiology and End Results (SEER) database (1998–2012,
N
= 981). Factors associated with LN status were analyzed by logistic regression and by Cox analyses.
Results
For T1–T2 tumors, N status was associated only with tumor size. N status (
p
= 0.001), grade (
p
< 0.001), age (
p
= 0.001), and sex (
p
= 0.007) predicted overall survival (OS). For T3–T4, grade (
p
< 0.001), sex (
p
= 0.004), size (
p
= 0.013), and age (
p
= 0.007) but not N status (
p
= 0.789) predicted OS. For T1–T2, disease-specific survival (DSS;
p
= 0.003) and OS (
p
= 0.008) were longer for N0 vs N1, while N0 vs NX had similar OS (
p
= 0.59) and DSS (
p
= 0.80). While a difference was seen in DSS for NX vs N1 (
p
= 0.04), no significant difference in OS was seen (
p
= 0.08). For T3–T4, N status did not affect DSS (
p
= 0.365) or OS (
p
= 0.454). For all T groups and any N status, extended LA (≥10 nodes resected) was not associated with OS.
Conclusion
While in T1–T2 pNET N1 status is a predictor of negative OS, similar outcome between NX and N0 supports limited LN resection in selected patients. Extended LA is unlikely to be helpful in T3–T4.
Abstract Background Acute kidney injury (AKI) is a common complication in the early period of lung transplantation (LTx). We aimed to describe the incidence and perioperative risk factors associated ...with AKI following LTx. Methods Clinical data of 30 patients who underwent LTx were retrospectively reviewed. Primary outcomes were development of AKI and patient mortality within 30 postoperative days. Postoperative AKI is determined based on creatinine criteria from Acute Kidney Injury Network (AKIN) classification. Secondary outcomes included the association between AKI and demographic and clinical parameters of patients and treatment modalities in the pre- and postoperative periods. Results Of the 30 LTx recipients included, AKI occurred in 16 patients (53.4%) within the first 30 days. Length of intensive care unit ( P = .06) and hospital stay ( P = .008) and mechanical ventilation duration ( P = .03) were significantly higher in patients with AKI compared with patients without AKI. Factors independently associated with AKI were intraoperative hypotension (odds ratio OR 0.500; 95% confidence interval CI, 1.145 to 26.412, P = .02), longer duration of mechanical ventilation (OR 1.204; 95% CI 0.870 to 1.665, P = .03), and systemic infection (OR 8.067; 95% CI 1.538 to 42.318, P = .014) in the postoperative period. Short-term mortality was similar in patients with and patients without AKI. Conclusion By the AKIN definition, AKI occurred in half of the patients following LTx. Several variables including intraoperative hypotension, longer duration of mechanical ventilation, and systemic infection in the postoperative period independently predict AKI in LTx recipients.
Reducing noise to the quantum limit over a large bandwidth is a fundamental requirement for future applications operating at millikelvin temperatures, such as the neutrino mass measurement, the ...next-generation X-ray observatory, the CMB measurement, the dark matter and axion detection, and the rapid high-fidelity readout of superconducting qubits. The read out sensitivity of arrays of microcalorimeter detectors, resonant axion-detectors, and qubits, is currently limited by the noise temperature and bandwidth of the cryogenic amplifiers. The Detector Array Readout with Traveling Wave Amplifiers project has the goal of developing high-performing innovative traveling wave parametric amplifiers with a high gain, a high saturation power, and a quantum-limited or nearly quantum-limited noise. The practical development follows two different promising approaches, one based on the Josephson junctions and the other one based on the kinetic inductance of a high-resistivity superconductor. In this contribution, we present the aims of the project, the adopted design solutions and preliminary results from simulations and measurements.
Ultralow-noise microwave amplification and detection play a central role in different applications, going from fundamental physics experiments to the deployment of quantum technologies. In many ...applications the necessity of reading multiple detectors, or cavities or qubits, calls for large bandwidth amplifiers with the lowest possible noise. Current technologies are based on High Electron Mobility Transistors and Josephson Parametric Amplifiers. Both have limitations, the former in terms of the minimum noise, the latter in terms of bandwidth. Superconducting Traveling Wave Parametric Amplifiers (TWPAs) have the potential of offering quantum limited noise and large bandwidth. These amplifiers are based on the parametric amplification of microwaves traveling along a transmission line with embedded nonlinear elements. We are developing superconducting TWPAs based both on Josephson junction arrays (Traveling Wave Josephson Parametric Amplifiers) and on nonlinear kinetic inductance (Dispersion Engineered Traveling Wave Kinetic Inductance Amplifiers). Our goal is to achieve large bandwidth (in the 5 to 10 GHz range), large gain (more than 20 dB), large saturation power (more than −50 dBm), and near quantum limited noise (noise temperature less than 600 mK). Current achievements in the design and development of the high performance TWPAs are here reported and discussed, together with current limitations and possible future developments.
Abstract Background Lymph node positivity is a strong prognostic indicator in many cancers including gastric cancer. The extent of surgical resection directly influences the number of lymph nodes ...available for staging, with the lesser D1 resection that is standard practice in non-Asian countries typically providing fewer nodes for analysis. The widely used AJCC TNM staging system has been criticized for under-staging and stage migration where fewer than 15 nodes are resected, which is often the case in these populations. The ratio of positive to total nodes harvested – Lymph Node Ration (LNR) – has been proposed as an improved and more widely applicable prognostic indicator. Hypothesis The LNR is a reliable and accurate prognostic indicator of survival in a Western gastric cancer population. Methods 9357 patients were acquired via a SEER case listing session with 2004–2011 gastric adenocarcinoma diagnoses. AJCC 7th edition nodal staging (N0: 0, N1:1–2, N2:3–6, N3:≥7 positive lymph nodes) and LNR positive nodal staging (PN0: 0%, PN1: 1–20%, PN2: 21–50%, PN3: 51–100% of examined nodes positive) were compared as respects seven year survivorship. Results Adjusted survival time ratios for AJCC nodal curves were less evenly distributed than were the percent positive nodal curves. Results of multiple regression reflected that survival time ratios of the percent positive nodal schema being more evenly spaced than those of the AJCC schema. Because BIC for AJCC, 41071.48, was larger than that for percent positive nodes, 41024.25, the LNR nodal system better explained survival than the AJCC nodal classification system. Conclusion LNR produced reliable and internally consistent survival curves for this population. LNR is an effective tool to predict survival in a western gastric cancer patient population, where the majority of the patients have limited lymph node dissection.
Abstract Background Osteoporosis is a well-recognized complication in lung transplantation because of steroid use and immobilization. The aim of the study was to assess the prevalence of osteoporosis ...and risk factors associated with osteoporosis in lung transplantation candidates. Methods The bone mineral density of 174 patients with various end-stage lung diseases was assessed at the pretransplantation period. Osteoporosis risk factors were analyzed with the consideration to principal diagnosis, demographic, and clinical parameters of lung disease, lung function tests and mobility test (6-minute walking test). A multivariate analysis was conducted to determine various demographic and clinical risk factors associated with bone mass loss in the pretransplant period. Results The prevalence of osteoporosis and osteopenia was 46% and 35%, respectively, in the study population. Osteoporotic patients have lower body mass index and lower 6-minute walking distance than patients without osteoporosis. In addition, they have higher pulmonary artery pressure and history of noninvasive mechanical ventilation than in patients without osteoporosis. There was a significant negative correlation between the 6-minute walking test, body mass index, and the presence of osteoporosis in the study population. Multivariate logistic regression analysis confirmed that 6-minute walking test (odds ratio, 0.996) and body mass index (odds ratio, 0.847) were significantly and negatively correlated with the presence of osteoporosis. Conclusions A significant proportion of patients with end-stage lung diseases have osteopenia or osteoporosis pretransplantation. This is the first study to demonstrate that 6-minute walking distance and bone mineral density independently predict osteoporosis in lung transplant candidates.
The advent of ultra-low noise microwave amplifiers revolutionized several research fields demanding quantum-limited technologies. Exploiting a theoretical bimodal description of a linear ...phase-preserving amplifier, in this contribution we analyze some of the intrinsic properties of a model architecture (i.e., an rf-SQUID based Josephson Traveling Wave Parametric Amplifier) in terms of amplification and noise generation for key case study input states (Fock and coherent). Furthermore, we present an analysis of the output signals generated by the parametric amplification mechanism when thermal noise fluctuations feed the device.
Abstract Background Right heart catheterization (RHC) remains the gold standard to diagnosis of pulmonary hypertension among lung transplantation candidates. Doppler echocardiography (DE) may be as ...accurate as RHC, without risks of an invasive test. The aim of the study was to assess the feasibility of DE for the measurement of pulmonary artery pressure in lung transplantation candidates and the correlation between pulmonary artery pressures estimated by DE versus measured by RHC. Methods A total of 103 lung transplantation candidates undergoing DE who were scheduled to undergo RHC within 72 hours were analyzed. The performance characteristics of DE were compared with RHC, and correlation analysis was performed to determine the correlation of pulmonary pressures obtained by DE versus measured by RHC. Results The prevalence of pulmonary hypertension was 57% in lung transplantation candidates. Of the 103 candidates, evaluation of pulmonary artery systolic pressure (PASP) by DE was possible in 92 (89%). Median PASP by RHC was 45 (12–145) mm Hg and by DE 45 (20–144) mm Hg. There was a positive correlation between PASP estimated by DE and measured by RHC ( r = 0.585, P < .0001). Sensitivity, specificity, and positive and negative predictive values of PASP estimation for diagnosis of pulmonary hypertension were 85%, 67%, 87%, and 61%, respectively. Conclusions There is a strong positive correlation between PASP estimated by DE compared with measured by RHC with an acceptable sensitivity and specificity in detecting pulmonary hypertension. Echocardiography can be recommended for measuring pulmonary pressures in lung transplantation candidates.
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