Count Loss Research Articles

High-speed and low-distortion solution for time-correlated single photon counting measurements: A theoretical analysis.

In this paper, we describe a novel solution to increase the speed of Time-Correlated Single Photon Counting (TCSPC) measurements by almost an order of magnitude while providing, in principle, zero distortion regardless of the experimental conditions. Typically, the relatively long dead time associated with the conversion electronics requires a proper tune of the excitation power in order to avoid distortions of the reconstructed waveform due to pileup and counting loss. As a result, the maximum operating rate of a TCSPC channel is now limited between 1% and 5% of the excitation frequency, thus leading to relatively long acquisition times. We show that negligible distortion (below 1%) is guaranteed if the dead time associated with the converter is kept below the dead time of the detector, and at the same time the detector dead time is matched to the duration of the excitation period. In this way, unprecedented high-speed operation is possible. In this paper, we provide a theoretical analysis of the technique, including the main non-idealities which are introduced by a generic physical implementation. The results are supported by both numerical simulations and analytical calculations.

Characterisation of a neutron diffraction detector prototype based on the Trench-MWPC technology

The Trench Multi-Wire-Proportional-Chamber is a new type of MWPC which has been designed to fulfill the requirements of the 2D curved neutron detector under development for the XtremeD neutron diffractometer, under construction at ILL. In this design, anode wires are mounted orthogonally to a stack of metallic cathode plates which are insulated from each other by ceramic spacers. A row of teeth is spark-eroded along the edge of the cathode plates so that anode wires appear to be stretched along trenches machined across a segmented cathode plane. This design was tested on a prototype detector module mounted in a vessel filled with a mixture of 3He-Ar-CO2 at 7 bar. The detector configuration as well as measurements performed on this prototype at ILL neutron test beam line are presented. Results show that the Trench-MWPC design provides uniform amplification gain across the detection area despite the absence of the top cathode wires used to balance the electric field in standard Cathode-Anode-Cathode MWPC configurations. The presence of cathode trench side-walls surrounding anode wires minimises the spread of neutron-induced charge across electrodes, allowing for detector operation at reduced amplification gain without compromising the signal to noise per electrode. Pulse-height spectra acquired under various neutron flux conditions demonstrated that the Trench-MWPC design minimises space-charge effects, thanks to its low amplification gain combined with the fast collection of ions by cathode trench side-walls surrounding anode wires. Measurements also showed that this space-charge effect reduction results in a high local count-rate of ∼100 kHz at 10% count loss when irradiating the detector with a small 5 mm × 5 mm neutron beam.

Comparison of efficacy between coaxial microincision and standard-incision phacoemulsification in patients with age-related cataracts: a meta-analysis

BackgroundIncision size plays a critical role in the efficacy of cataract surgery, but the available evidence on ideal incision size is inconsistent. In this study, we conducted a meta-analysis to evaluate the efficacy of coaxial microincisional phacoemulsification surgery (MICS) compared with that of standard-incision phacoemulsification surgery (SICS) in patients with age-related cataracts.MethodsThe Cochrane Library (Wiley Online Library), PubMed, Medline, National Knowledge Infrastructure (CNKI), and VIP databases were searched to identify reports of clinical randomized controlled trials (RCTs) comparing MICS to SICS for the treatment of age-related cataracts. The outcomes of interest included surgically induced astigmatism (SIA), effective phacoemulsification time (EPT), central corneal thickness (CCT), endothelial cell count (ECC), endothelial cell count loss (ECC Loss %), and average ultrasonic energy (AVE).ResultsEleven RCT studies were included in this meta-analysis. No statistically significant differences were observed in EPT (Z = 1.29, P > 0.05), CCT (1 day: Z = 1.37, P > 0.05; 7 days: Z = 0.75, P > 0.05; 30 days: Z = 0.38, P > 0.05; 90 days: Z = 0.29, P > 0.05), ECC (7 days: Z = 1.13, P > 0.05; 30 days: Z = 1.42, P > 0.05) or ECC Loss % (7 days: Z = 0.24, P > 0.05; 30 days: Z = 0.06, P > 0.05; 90 days: Z = 0.10, P > 0.05) between MICS and SICS. However, statistically significant differences were found in AVE (Z = 4.19, P < 0.0001) and SIA (1 day: Z = 10.33, P < 0.00001; 7 days: Z = 10.71, P < 0.00001; 30 days: Z = 10.95, P < 0.00001; 90 days: Z = 2.21,- P < 0.01) between MICS and SICS.ConclusionCompared with SICS, MICS can reduce short-term and long-term SIA, but it does not differ in safety outcomes or in the time required for surgery.

Installation of a high-resolution position-sensitive scintillation detector in the small and wide angle neutron scattering instrument (TAIKAN), MLF, J-PARC

The small and wide angle neutron scattering instrument (TAIKAN) installed at the Material and Life Science Experimental Facility (MLF), Japan Proton Accelerator Research Complex (J-PARC) can cover a Q-range from 5 × 10−3 to 17 Å−1 simultaneously, where the magnitude of the scattering vector Q is defined by Q = 4πsin(θ/2)/λ (θ and λ represent the scattering angle and the wavelength, respectively). To extend the accessible low Q-limit (Qmin) to a value in the order of 10−4 Å−1, we successfully installed an ultra-small-angle detector with a spatial resolution of approximately 0.41 mm × 0.41 mm in TAIKAN. This detector is a high-resolution position-sensitive detector (HR-PSD), comprising a cross-wired position-sensitive photomultiplier tube and a ZnS/6LiF scintillator. HR-PSDs of the same type have been installed on steady-state small-angle neutron scattering (SANS) instruments at the research reactor (JRR-3), Japan. Comparing with these previously installed the HR-PSDs, we improved most of the HR-PSD components such as the scintillator, preamplifier, and data acquisition systems to increase its maximum count rate. A maximum count rate of 46 kcps was achieved with 10% counting loss, which is 2.3 times for those installed in the steady-state SANS instruments at JRR-3. Using the ultra-small-angle detector with existing 3He detector banks, TAIKAN can simultaneously cover a Q-range from 8 × 10−4 Å−1 to 17 Å−1 (over four orders of magnitude in Q).

The nature and burden of occupational injury among first responder occupations: A retrospective cohort study in Australian workers

IntroductionWorkers in first responder (FR) occupations are at heightened risk for workplace injury given their exposure to physical/psychological hazards. This study sought to (1) characterise the occupational risk of injury; (2) determine factors associated with injury; and (3) characterise the burden of injury-related disability in police, ambulance officers, fire/emergency workers, compared with other occupations. MethodsA retrospective cohort of 2,439,624 claims occurring between July 2003 and June 2012 was extracted from the Australian National Dataset for Compensation-Based Statistics. Cases aged 16–75 years working 1–100 pre-injury hours per week were included. Regression models estimated risk of making a workers’ compensation (WC) claim by age, gender, occupation and injury type. Injury burden was calculated using count and time loss, and statistically compared between groups. ResultsThe risk of making a WC claim among FR occupations was more than 3 times higher than other occupations. Risk of claiming was highest among female FRs and those aged 35–44 years. Ambulance officers had the greatest risk of upper-body MSK injuries and fire and emergency workers the greatest risk of lower-body MSK injuries. The risk of mental health conditions was elevated for all FR occupations but highest among police officers. The total burden of injury (expressed as working weeks lost per 1000 workers) differed significantly between groups and was highest amongst police. Discussion and conclusionsFirst responders record significantly higher rates of occupational injury claims than other occupations. Using a national population based dataset, this study demonstrates that not only are first responders exposed to significantly higher rates of occupational injury than all other occupations combined, but they experience differential injury patterns depending on their occupation. This suggests that among FR occupations injury prevention efforts should reflect these differences and be targeted to occupation-specific patterns of injury.

Somatic Cell Count and Milk Yield Losses in Goats

This work is aimed at prediction and quantification of goat milk yield (MY, kg) losses by the somatic cell count (SCC, 103.ml−1) in milk recording. The goal is to support the prevention of milk secretion disorders, milk yield and quality. During two years there were evaluated composition and properties of individual milk samples (n = 1 173). There were included animals of brown short‑haired (BSH) breed and BSH × white short‑haired in one flock. The linear and nonlinear regression, interpolation, extrapolation, approximation and qualified estimation were used for milk losses prediction along the SCC. The relevant values of the SCC arithmetic and geometric mean and median and MY arithmetic mean were: 1,400 103.ml−1 (with high variability of 128 %), 745 and 747 103.ml−1; 2.94 kg/ day. The relationship between fat and crude protein had a correlation coefficient of 0.395, P &lt; 0.001. There were stated the correlations between SCC and: lactose −0.416, P &lt; 0.001; solids non fat −0.25, P &lt; 0.001; MY −0.135, P &lt; 0.01. The relationship between SCC and MY was negative along months, 6 cases out of 7 and significant in March and May (P &lt; 0.05 and P &lt; 0.01). For instance predicted MY for SCC intervals 1–1.999, 2–2.999, 3–3.999, 4–4.999, 5–5.999, 6–6.999 and ≥ 7 thousands 103.ml−1 may be 3.99, 3.77, 3.6 , 3.46, 3.33, 3.23 and 3.13 kg in 3rd month etc. The corresponding MY losses by SCC are evident from this trend. The result use is focused on the original dairy goat farm and use elsewhere is possible in farms with similar SCC, goat milk yield and rearing system.

New bidirectional multilevel inverter topology with staircase cascading for symmetric and asymmetric structures

Inverters, as one of the key components of electrical systems, have experienced a great evolution in the last decade, and their performance improvement is a challenge even today, leading to many researches on topologies and control schemes. This study introduces a new multilevel converter topology which is able to supply bidirectional current loads. The proposed structure has fewer power electronic devices such as power switches, driver circuits, power diodes, and DC voltage sources and, can be designed in both symmetric and asymmetric structures. In order to increase the number of output levels and the proposed basic unit development, modular expansion or cascading methods can be used. This study demonstrates that the aforementioned methods have the best results in asymmetric and symmetric structures of the proposed topology, respectively. The comparison between the proposed converter and some previous topologies shows that it has better conditions with respect to the used semiconductor count, switching and conduction losses, and total blocking voltage. The operation and performance of the proposed multi-level converter have been ascertained through simulations and verified experimentally for a single-phase symmetric thirty-one-level inverter which shows the proposed converter's ability in smooth sinusoidal output voltage generation with minimum total harmonic distortion.

EFFECT OF CONSUMING RED SPINACH (AMARANTHUS TRICOLOR L) EXTRACT ON HEMOGLOBIN LEVEL IN POSTPARTUM MOTHERS

Background: Postpartum mothers are susceptible to anemia, due to loss of blood count during labor. Postpartum anemia causes uterine subinvolution which causes postpartum hemorrhage, facilitates puerperium infection, decreases breastfeeding and easy mamae infection. One alternative to prevent anemia in postpartum is to consume vegetables with high iron one red spinach. Red spinach is one of the non-heme iron sources needed to synthesize hemoglobin.Objective: To determine the effect of red spinach in increasing the levels of hemoglobin in postpastum mothers.Methods: This was a quasy experiment with pretest posttest with control group design in October-December 2017 at the Community Health Center of PONED Tarub, Tegal regency. Thirty postpartum mothers were included using purposive sampling, which 15 assigned in each group. Blood sampling and examination were performed in each respondent. Paired and Independent t-test were done for data analysis.Results: The results of the 14-day intervention of given red spinach extract showed that there was a significant increase of hemoglobin level (1.25 g / dL) with p-value 0.047.Conclusion: There is a significant effect of consuming red spinach extract (amaranthus tricolor L.) on the increase of hemoglobin level in postpartum mother. It is recommended that midwives could apply this intervention and cooperate with agriculture and food processing in order to produce red spinach extract that increases hemoglobin, hematocrit and erythrocytes levels.

Measurement of isomeric yield ratios of 99m,g;101m,g;102m,gRh in the natPd(γ,pxn) reactions with the bremsstrahlung end-point energies of 50–70 MeV

The isomeric yield ratios of 99m,gRh, 101m,ggRh, and 102m,gRh isomeric pairs produced from the natPd(γ,pxn) reactions were measured with the bremsstrahlung end-point energies of 50-, 55-, 60-, 65-, and 70-MeV at the 100MeV electron linac of the Pohang Accelerator Laboratory, Korea. The measurements were carried out with the activation method in combination with off-line γ-ray spectrometry. In order to improve the accuracy of the activity measurements, the separation of the overlapping γ-rays and the necessary corrections for the counting losses were made. The new experimental results are compared with the theoretical values of the TALYS-1.6 code.

HIV type 2 epidemic in Spain: challenges and missing opportunities.

: HIV type 2 (HIV-2) is a neglected virus despite estimates of 1-2 million people infected worldwide. HIV-2 is less efficiently transmitted than HIV-1 by sex and from mother to child. Although AIDS may develop in HIV-2 carriers, it takes longer than in HIV-1-infected patients. In contrast with HIV-1 infection, there is no global pandemic caused by HIV-2, as the virus is largely confined to West Africa. In a less extent and due to socioeconomic ties and wars, HIV-2 is prevalent in Portugal and its former colonies in Brazil, India, Mozambique and Angola. Globally, HIV-2 infections are steadily declining over time. A total of 338 cases of HIV-2 infection had been reported at the Spanish HIV-2 registry until December 2016, of whom 63% were men. Overall 72% were sub-Saharan Africans, whereas 16% were native Spaniards. Dual HIV-1 and HIV-2 coinfection was found in 9% of patients. Heterosexual contact was the most likely route of HIV-2 acquisition in more than 90% of cases. Roughly one-third presented with CD4 cell counts less than 200 cells/μl and/or AIDS clinical events. Plasma HIV-2 RNA was undetectable at baseline in 40% of patients. To date, one-third of HIV-2 carriers have received antiretroviral therapy, using integrase inhibitors 32 individuals. New diagnoses of HIV-2 in Spain have remained stable since 2010 with an average of 15 cases yearly. Illegal immigration from Northwestern African borders accounts for over 75% of new HIV-2 diagnoses. Given the relatively large community of West Africans already living in Spain and the continuous flux of immigration from endemic regions, HIV-2 infection either alone or as coinfection with HIV-1 should be excluded once in all HIV-seroreactive persons, especially when showing atypical HIV serological profiles, immunovirological disconnect (CD4 cell count loss despite undetectable HIV-1 viremia) and/or high epidemiological risks (birth in or sex partners from endemic regions).

Quantitative Measurement of Dual-Radioisotopes of Technetium-99m and Iodine-123 in Blood Samples With a Cadmium-Telluride-Based Counting Device

Our previous study demonstrated that a cadmium telluride (CdTe)-based single-photon emission computed tomography (SPECT) system with good energy resolution could provide dual-radioisotope SPECT images of a patient who had been administered with two kinds of radioisotope simultaneously. To obtain two quantitative physiological parametric images from these radioisotope images by using compartment model analysis, the concentrations of the dual-radioisotope in the blood sample need to be measured. In this paper, a CdTe-based well counter was developed to measure the concentrations of a dual-radioisotope of 99mTc and 123I, and its performance was evaluated. The counter consists of four detector panels. Each detector panel consists of two detector modules, and each module has $16\,\, {\times } \,\, 16$ CdTe detector pixels with a pitch of 2.5 mm; the eight detector modules give our system a field of view ( $ {x} {\times } \,\, {y} {\times } {z}$ ) of $4\,\, {\times } \,\, 4\,\, {\times } \,\, 8$ cm3. The crosstalk correction coefficient $ {{{\alpha }}}$ , which is the ratio of the count rate in the 99mTc-energy window to that in the 123I-energy window, was obtained by measuring the single-radioisotope solution of 123I. When the dual-radioisotope of 99mTc and 123I was measured, the true count rate of 99mTc was obtained by subtracting the crosstalk count rate ( $ {{{\alpha }}} \,\, {\times }$ the count rate of 123I) from the uncorrected count rate of 99mTc. To evaluate the measurement accuracy, dual- and single-radioisotope solutions were measured, and the mean percentage error of the measured count rate of dual-radioisotope solutions to that of the single-radioisotope solution was obtained. The energy resolutions full width at half maximum of the CdTe-based well counter were 6.95% and 6.93% at 140.5 keV and 159 keV, respectively, and were higher than that of a conventional NaI (Tl) scintillation detector (10% at 140.5 keV). The count loss in the CdTe detector was 1.7% at 44 kcps. For the dual-radioisotope measurement, the percentage errors (mean percentage% ± standard deviation%, ${N} \,\, {=}$ 3) of the count rate of 99mTc and 123I at a high count rate (99mTc: 44 kcps, 123I: 28 kcps) were −1.9% ± 0.0% and −3.5% ± 1.1%, respectively. On the other hand, the percentage errors of the count rate of 99mTc and 123I at a low count rate (99mTc: 3 kcps, 123I: 4 kcps) were −0.4% ± 0.3% and 0.2% ± 0.6%, respectively. The CdTe-based well counter measured each concentration of 99mTc and 123I in mixed solutions with high accuracy.

Determination of track counting loss threshold of spark counter due to high track densities on strippable LR115 II nuclear track detectors

Nuclear track etched detectors are widely used for radon measurements. At the Department of Physics, University of Osijek, the strippable nuclear track detectors LR115 type II are used for indoor radon measurements and their tracks are counted by a spark counter. The probability of track counting loss by saturation rises with the track density.A hundred of strippable nuclear track etched films LR115 type II were irradiated with a constant flux of α-particles in different times using a home-made “KVOD” device for controlling time of irradiation and a saturation effect at high track densities (above 6000 tr/cm2) was observed. The track counting loss threshold of 6200 tr/cm2 was determined for the used type of spark counter and a correction function for track counting was found. Direct counting of aluminium sublimated spots and tracks by the optical counting system confirmed the validity of track counting correcting formula for this type of spark counter.

Performance Characteristics of the Whole-Body Discovery IQ PET/CT System.

The aim of this study was to assess the physical performance of a new PET/CT system, the Discovery IQ with 5-ring detector blocks. Methods: Performance was measured using the National Electrical Manufacturers Association NU2-2012 methodology. Image quality was extended by accounting for different acquisition parameters (lesion-to-background ratios [8:1, 4:1, and 2:1] and acquisition times) and reconstruction algorithms (VUE-point HD [VPHD], VPHD with point-spread-function modeling [VPHD-S], and Q.Clear). Tomographic reconstruction was also assessed using a Jaszczak phantom. Additionally, 30 patient lesions were analyzed to account for differences in lesion volume and SUV quantification between reconstruction algorithms. Results: Spatial resolution ranged from 4.2 mm at 1 cm to 8.5 mm at 20 cm. Sensitivity measured at the center and at 10 cm was 22.8 and 20.4 kps/kBq, respectively. The noise-equivalent counting rate peak was 124 kcps at 9.1 kBq/cm3 The scatter fraction was 36.2%. The accuracy of correction for count losses and randoms was 3.9%. In the image quality test, contrast recovery for VPHD, VPHD-S, and Q.Clear ranged from 18%, 18%, and 13%, respectively (hot contrast; 10-mm sphere diameter; ratio, 2:1), to 68%, 67%, and 81%, respectively (cold contrast; 37-mm sphere diameter; ratio, 8:1). Background variability ranged from 3.4%, 3.0%, and 2.1%, respectively (ratio, 2:1), to 5.5%, 4.8%, and 3.7%, respectively (ratio, 8:1). On Q.Clear reconstruction, the decrease in the penalty term (β) increased the contrast recovery coefficients and background variability. With the Jaszczak phantom, image quality increased overall when a reconstruction algorithm modeling the point-spread function was used, and use of Q.Clear increased the signal-to-noise ratio. Lesions analyzed using VPHD-S and Q.Clear had an SUVmean of 6.5 ± 3 and 7 ± 3, respectively (P < 0.01), and an SUVmax of 11 ± 4.8 and 12 ± 4, respectively (P < 0.01). No significant difference in mean lesion volume was found between algorithms. Conclusion: Among the various Discovery bismuth germanium oxide-based PET/CT scanners, the IQ with 5-ring detector blocks has the highest overall performance, with improved sensitivity and counting rate performance. Q.Clear reconstruction improves the PET image quality, with higher recovery coefficients and lower background variability.

An innovative method to reduce count loss from pulse pile-up in a photon-counting pixel for high flux X-ray applications

In this study, an innovative fast X-ray photon-counting pixel for high X-ray flux applications is proposed. A computed tomography system typically uses X-ray fluxes up to 108 photons/mm2/sec at the detector and thus a fast read-out is required in order to process individual X-ray photons. Otherwise, pulse pile-up can occur at the output of the signal processing unit. These superimposed signals can distort the number of incident X-ray photons leading to count loss. To minimize such losses, a cross detection method was implemented in the photon-counting pixel. A maximum count rate under X-ray tube voltage of 90 kV was acquired which reflect electrical test results of the proposed photon counting pixel. A maximum count of 780 kcps was achieved with a conventional photon-counting pixel at the pulse processing time of 500 ns, which is the time for a pulse to return to the baseline from the initial rise. In contrast, the maximum count of about 8.1 Mcps was achieved with the proposed photon-counting pixel. From these results, it was clear that the maximum count rate was increased by approximately a factor 10 times by adopting the cross detection method. Therefore, it is an innovative method to reduce count loss from pulse pile-up in a photon-counting pixel while maintaining the pulse processing time.

Energy-correction photon counting pixel for photon energy extraction under pulse pile-up

A photon counting detector (PCD) has been proposed as an alternative solution to an energy-integrating detector (EID) in medical imaging field due to its high resolution, high efficiency, and low noise. The PCD has expanded to variety of fields such as spectral CT, k-edge imaging, and material decomposition owing to its capability to count and measure the number and the energy of an incident photon, respectively. Nonetheless, pulse pile-up, which is a superimposition of pulses at the output of a charge sensitive amplifier (CSA) in each PC pixel, occurs frequently as the X-ray flux increases due to the finite pulse processing time (PPT) in CSAs. Pulse pile-up induces not only a count loss but also distortion in the measured X-ray spectrum from each PC pixel and thus it is a main constraint on the use of PCDs in high flux X-ray applications. To minimize these effects, an energy-correction PC (ECPC) pixel is proposed to resolve pulse pile-up without cutting off the PPT by adding an energy correction logic (ECL) via a cross detection method (CDM). The ECPC pixel with a size of 200×200µm2 was fabricated by using a 6-metal 1-poly 0.18µm CMOS process with a static power consumption of 7.2 μW/pixel. The maximum count rate of the ECPC pixel was extended by approximately three times higher than that of a conventional PC pixel with a PPT of 500 nsec. The X-ray spectrum of 90 kVp, filtered by 3mm Al filter, was measured as the X-ray current was increased using the CdTe and the ECPC pixel. As a result, the ECPC pixel dramatically reduced the energy spectrum distortion at 2 Mphotons/pixel/s when compared to that of the ERCP pixel with the same 500 nsec PPT.

P1.07-040 Prognostic Factors in Extensive Disease (ED) Small Cell Lung Cancer (SCLC): An ELCWP Phase III Randomized Trial

Main prognostic factors for survival in SCLC patients are performance status, disease extent, age or gender, as previously reported by the European Lung Cancer Working Party (ELCWP) (Paesmans et al, Eur Respir J 2011). Based on a previous meta-analysis (Mascaux et al, Lung Cancer 2000) showing a survival advantage for regimens including cisplatin (CDDP) or etoposide (VP16), the ELCWP designed a phase III trial to determine if addition of CDDP to VP16 would improve survival in comparison with VP16 combination without CDDP in a population of ED SCLC. The aim of this work was to search for prognostic factors for survival. Untreated patients with ED (limited (LD) not amenable to radiotherapy or stage IV disease) SCLC, Karnofsky performance status (PS) ≥60, adequate hematological, hepatic, renal and cardiac functions, were centrally randomized to receive either CDDP-VP16 (CE) or ifosfamide-VP16-epirubicin (IVE). According to statistical considerations, 315 deaths had to occur before analysis. Univariate and multivariate tests were performed for prognostic factors analyses. 346 eligible patients were randomized (176 in CE and 170 in IVE arms) between 2000 and 2013. At the time of analysis, 329 deaths occurred. No statistically significant imbalance was observed regarding age, gender, PS, disease extent (LD vs stage IV), neutrophil count and weight loss. No statistically significant difference was observed between CE and IVE groups according to main evaluation criteria: best response rate (60% vs 59%, p=0.88), progression-free survival (median 5.1 vs 5.3 months; p=1) and overall survival times with medians of 9.6 months and 10 months and 2-year rates of 5 % and 9 % (p=0.16), respectively. The following variables were statistically significantly associated with survival in univariate analysis: age (continuous evaluation) (HR=1.02, p=0.002), gender (male as reference) (HR=0.69, p=0.008), PS (PS ≤ 70 as reference) (HR=0.60, p=0.0001), weight loss (≤5% as reference) (HR=1.28, p=0.05) and neutrophil count (≤7500/mm3 as reference) (HR=1.46, p=0.003). In addition, variables with a p-value < 0.2 in univariate analysis were also included in the multivariate analysis: disease extent (LD as reference) (HR=1.38, p=0.10), WBC count (≤10000/mm3 as reference) (HR=1.23, p=0.08) and treatment arm (CE as reference) (HR=0.84, p=0.16). Two variables retained their statistical significance in multivariate analysis: gender (HR=0.69, 95% CI 049-0.97; p=0.03) and PS (HR=0.53, 95% CI 0.49-0.97; p<0.0001). Adding CDDP to VP16 failed improving survival in ED SCLC. In this population, gender and performance status confirmed their prognostic value for survival.

Development of a cloud particle sensor for radiosonde sounding

Abstract. A meteorological balloon-borne cloud sensor called the cloud particle sensor (CPS) has been developed. The CPS is equipped with a diode laser at ∼ 790 nm and two photodetectors, with a polarization plate in front of one of the detectors, to count the number of particles per second and to obtain the cloud-phase information (i.e. liquid, ice, or mixed). The lower detection limit for particle size was evaluated in laboratory experiments as ∼ 2 µm diameter for water droplets. For the current model the output voltage often saturates for water droplets with diameter equal to or greater than ∼ 80 µm. The upper limit of the directly measured particle number concentration is ∼ 2 cm−3 (2 × 103 L−1), which is determined by the volume of the detection area of the instrument. In a cloud layer with a number concentration higher than this value, particle signal overlap and multiple scattering of light occur within the detection area, resulting in a counting loss, though a partial correction may be possible using the particle signal width data. The CPS is currently interfaced with either a Meisei RS-06G radiosonde or a Meisei RS-11G radiosonde that measures vertical profiles of temperature, relative humidity, height, pressure, and horizontal winds. Twenty-five test flights have been made between 2012 and 2015 at midlatitude and tropical sites. In this paper, results from four flights are discussed in detail. A simultaneous flight of two CPSs with different instrumental configurations confirmed the robustness of the technique. At a midlatitude site, a profile containing, from low to high altitude, water clouds, mixed-phase clouds, and ice clouds was successfully obtained. In the tropics, vertically thick cloud layers in the middle to upper troposphere and vertically thin cirrus layers in the upper troposphere were successfully detected in two separate flights. The data quality is much better at night, dusk, and dawn than during the daytime because strong sunlight affects the measurements of scattered light.

A Scalable, Partially Configurable Optical Switch for Data Center Networks

Optical circuit switching may be instrumental in meeting the cost, energy, and aggregate bandwidth requirements of future data center networks. However, conventional MEMS beam-steering cross-connects cannot provide submillisecond switching with the port count necessary for data centers. Here, we investigate a novel noncrossbar selector switch architecture and pupil-division switching layout to improve optical switching performance by relaxing the requirement of arbitrary switch configurability. This architecture and switch design enable MEMS beam-steering micromirrors to scale to microsecond response speeds while supporting high port count and low loss switching, and can realize a number of useful interconnection topologies. We present the design, fabrication, and experimental characterization of a proof-of-principle prototype using a single comb-driven MEMS mirror to achieve 150 μs switching of 61 ports between four preprogrammed interconnection mappings. We demonstrate the scalability of this switch architecture with a detailed optical design of a 2048-port selector switch with 20 μs switching time.

Determining the Optimal Dose of Radioactivity for Measuring Glomerular Filtration using Gate’s Method and Obtaining Renogram

Objectives: Measuring Glomerular Filtration (GFR) using Gate’s method gives low radioactivity of approximately 74~111 MBq to a patient. Such low counts on image acquisition degrade image quality. The objective of this study was to limit the amount of radioactivity needed to acquire high-quality dynamic renal images when measuring GFR. Methods/Statistical Analysis: We performed experiments with different radio activities at matrix size of 128 x 128 or other matrix sizes to check overflow phenomenon of gammaray. Findings: Ideal total count was at radioactivity of approximately 37 MBq. However, measured total counts from acquire images showed certain counting loss. The average margin of error was –1.88 ± 1.61%. The mean value of GFR according to the radioactivity at more than 370 MBq was –2.91 ± 1.19 %. We could calculate GFR by substituting these results in GFR formula under the same condition. The mean GFR value was –1.89 ± 1.62% at radioactivity of 37 MBq and –2.93±1.2 % at radioactivity of more than 370 MBq. Conclusion: High-quality functional image could be acquired at the same time by increasing radioactivity to 370 MBq with higher matrix size. Improvements/Applications: With these results, we can improve diagnostic ability and make more accurate evaluation of renal function.

Effects of Internal Bremsstrahlung on Tritium Profile Reconstruction in BIXS Measurements

Beta-induced X-ray spectrometry (BIXS) is a nondestructive method to detect tritium both on the surface and in the bulk of materials. The effects of internal bremsstrahlung (IB) from the beta decay of tritium on tritium profile reconstruction have been theoretically studied by numerical simulation based on Matlab code. Three kinds of samples, two polymers [(T-C4H6O2)n, Zeff = 6.4, homogeneous and heterogeneous] and one zirconium, with different tritium depth profiles were used in the calculations, and two of them were confirmed by experiments. The results indicate that the intensity of IB is comparable with external bremsstrahlung (EB) for low-Z materials, and the intensity of IB decreases a little faster than that of EB for the same material. Neglecting IB would lead to as much as 12% counts loss in tritium profile reconstruction for a polymer sample, and it is expected to be more serious for lower-Z materials such as beryllium and carbon fiber composites. The results also show that for the same material, the influence of IB depends on the depth profile of tritium in the sample.