The repeatability and reproducibility of radiomic features extracted from CT scans need to be investigated to evaluate the temporal stability of imaging features with respect to a controlled scenario ...(test-retest), as well as their dependence on acquisition parameters such as slice thickness, or tube current. Only robust and stable features should be used in prognostication/prediction models to improve generalizability across multiple institutions. In this study, we investigated the repeatability and reproducibility of radiomic features with respect to three different scanners, variable slice thickness, tube current, and use of intravenous (IV) contrast medium, combining phantom studies and human subjects with non-small cell lung cancer. In all, half of the radiomic features showed good repeatability (ICC > 0.9) independent of scanner model. Within acquisition protocols, changes in slice thickness was associated with poorer reproducibility compared to the use of IV contrast. Broad feature classes exhibit different behaviors, with only few features appearing to be the most stable. 108 features presented both good repeatability and reproducibility in all the experiments, most of them being wavelet and Laplacian of Gaussian features.
Double-diffusive mixed convection problem had been a notable topic of research in the last decade. Lack of study is noticed under mixed convection using this double-diffusive in an enclosure ...specifically for roof-based ventilation systems with unsteady, partially heated conditions. This study investigates the Prandtl number effect in a double-diffusive unsteady flow in a square-shaped room where the upper channel was used for ventilation, and inside the enclosure, the walls are partially heated and mass concentrated. Galerkin residual method was implemented to get the governing equations. The Prandtl number 0.071 ≤ Pr ≤ 7.1 was chosen for the study, changing the dimensionless time 0.1 ≤ τ ≤ 1. The results have been shown in the mode of graphical representation and contour plots to observe the Prandtl number effect in such problem. The velocity streamline, isotherm, isoconcentration plots, heat and mass transfer rate, average fluid temperature and average mass concentration, etc., are shown. Results showed that heat and mass transfer rise with the growth of the Prandtl number. This research would be the guide for the design consideration in such double-diffusive systems like roof-based air ventilation systems with partial heat and mass generation.
The impact of surgeon and hospital volume on outcomes after radical prostatectomy (RP) for localised prostate cancer (PCa) remains unknown.
To perform a systematic review on the association between ...surgeon or hospital volume and oncological and nononcological outcomes following RP for PCa.
Medline, Medline In-Process, Embase, and the Cochrane Central Register of Controlled Trials were searched. All comparative studies for nonmetastatic PCa patients treated with RP published between January 1990 and May 2020 were included. For inclusion, studies had to compare hospital or surgeon volume, defined as caseload per unit time. Main outcomes included oncological (including prostate-specific antigen persistence, positive surgical margin PSM, biochemical recurrence, local and distant recurrence, and cancer-specific and overall survival) and nononcological (perioperative complications including need for blood transfusion, conversion to open procedure and within 90-d death, and continence and erectile function) outcomes. Risk of bias (RoB) and confounding assessments were undertaken. Both a narrative and a quantitative synthesis were planned if the data allowed.
Sixty retrospective comparative studies were included. Generally, increasing surgeon and hospital volumes were associated with lower rates of mortality, PSM, adjuvant or salvage therapies, and perioperative complications. Combining group size cut-offs as used in the included studies, the median threshold for hospital volume at which outcomes start to diverge is 86 (interquartile range IQR 35–100) cases per year. In addition, above this threshold, the higher the caseload, the better the outcomes, especially for PSM. RoB and confounding were high for most domains.
Higher surgeon and hospital volumes for RP are associated with lower rates of PSMs, adjuvant or salvage therapies, and perioperative complications. This association becomes apparent from a caseload of >86 (IQR 35–100) per year and may further improve hereafter. Both high- and low-volume centres should measure their outcomes, make them publicly available, and improve their quality of care if needed.
We reviewed the literature to determine whether the number of prostate cancer operations (radical prostatectomy) performed in a hospital affects the outcomes of surgery. We found that, overall, hospitals with a higher number of operations per year have better outcomes in terms of cancer recurrence and complications during or after hospitalisation. However, it must be noted that surgeons working in hospitals with lower annual operations can still achieve similar or even better outcomes. Therefore, making hospital’s outcome data publicly available should be promoted internationally, so that patients can make an informed decision where they want to be treated.
Higher surgeon and hospital volumes for radical prostatectomy are associated with lower rates of positive surgical margins, adjuvant or salvage therapies, and perioperative complications. Centres performing radical prostatectomy surgeries should make their outcomes publicly available for benchmarking purposes.
•Analyzed the effect of the Lewis number in a double-diffusive mixed convective problem.•The square enclosure is considered as room for air ventilation considering an upper channel.•It was observed ...that heat and mass transfer rate increase with the increase of Lewis number.•Average fluid temperature and mass concentration fall with the rise of Lewis number.
Double diffusive flow under mixed convection has become a significant area of research. This study aims to evaluate the Lewis number effect in such a double-diffusive problem in a roof-based air-ventilated system. The Lewis number 0.01 ≤ Le ≤ 5 was chosen for the study, considering other parameters as constant to observe the impact of different heat and mass transfer properties varying the dimensionless time 0.1 ≤ τ ≤ 1. The Galerkin residual technique was chosen to generate the governing equations. The outcomes have been plotted in streamlines, isotherms, isoconcentration, heat and mass transfer, average fluid temperature and mass concentration. The major findings elucidate that heat and mass transfer rate augments when Lewis number goes higher and vice versa. Moreover, when the thermal diffusivity is higher than the mass diffusivity, the average fluid temperature and mass concentration become lower. Overall, this study will be a guide on double-diffusive system design, such as roof-based air ventilation systems.
The goal of the paper is to evaluate the characteristics of the fluid flow, heat, and contaminant transfer in an indoor air environment. A two-dimensional ventilated space having a discrete heat and ...contaminant source at their mutually perpendicular position is constructed to conduct a numerical study. The governing equations with apprupirate boundary conditions of the model are evaluated by Galerkin weighted residual method. The transport characteristics are discussed for varying Richardson number 0.1 ≤ Ri ≤ 10 and dimension less time 0.1 ≤ τ ≤ 1 by the corresponding stream function, heat function, and mass function. Priority is given to analyzing the necessary factors – dependence on average Nusselt number, average Sherwood number, the average fluid temperature and mass concentration in the enclosure, along with the average temperature of the exit port to visualize the ventilation technique. Numerical output illustrates that – the attributes of the transport particles are largely determined by the interaction of the natural convection of heat and contaminant source with the mechanically forced flow of cool air. Results showed that mixed convection method is a better way to showcase efficient ventilation of the transport particles from the enclosure through a practical yet non-complex approach. This study will be a guide for design consideration for roof-based double-diffusive systems with partial heat and mass generation.
This numerical study was conducted to investigate the ventilation and airflow in a confined enclosure undergoing rapid inclusion of heat and contaminants representing air quality changes in working ...environments. A flow of air is passing inside a square enclosure with a heat source and a pollutant source on the right and bottom wall, creating double-diffusion, as well as two ventilation ducts on the upper sides asserting mixed convection. The Galerkin weighted residual method is implemented, which is based on the finite element method. For fixed values of Lewis number, Le = 0.5, Richardson number, Ri = 1, Reynolds number, Re = 100, and Prandtl number, Pr = 1.01, simulations were done with Buoyancy Ratio, Br = −10, 1, 10 and 20 over dimensionless time, τ = 0.1, 0.5, and 1.0. The results have been shown with the streamline, isothermal lines, iso-concentration lines, average Nusselt and Sherwood number, average fluid temperature, average mass concentration, and the average temperature at the square cavity's exit port plots. The findings have been discussed to ensure understanding of the changes in parameters, and an enhancement in heat as well as mass transfer was seen with the rapid change in dimensionless time. This specific study could be a guide for designing air conditioning and ventilation systems.
•Analyzed the effect of the Buoyancy Ratio in a double-diffusive mixed convective problem.•The square enclosure is considered as room for air ventilation considering an upper channel.•It was observed that heat and mass transfer rate increase with the increase of Buoyancy Ratio.•Average fluid temperature and mass concentration increase with the rise of Buoyancy Ratio.
Background: Globally 4 million newborn die every year before they reach the age of one month. To achieve the millennium developmental goals newborn survival is essential. Aim of the study was to ...assess the level of knowledge of antenatal women on essential new born care and danger signs during neonatal period, to find the association of sociodemographic and obstetric characteristics with maternal knowledge level. Settings and design included descriptive cross-sectional study was conducted in a tertiary care hospital.Methods: The study enrolled 439 antenatal women by convenient sampling technique. A pretested semi structured questionnaire was used to assess the knowledge. Statistical package for the social sciences (SPSS) 21 version was used to analysis the data. Chi square was calculated to find the association. P value of <0.05 was considered statistically significant.Results: The study shows that 16.7% respondents had adequate knowledge about danger signs during neonatal period. The maternal age, parity, socioeconomic status, parity had significantly associated with the maternal knowledge regarding new-born care (p<0.05).Conclusions: Majority of the ante natal mother had poor knowledge on new born care.
Abstract We present a comprehensive multiwavelength spectral analysis of the black hole (BH) X-ray binary MAXI J1820+070 during its 2018 outburst, utilizing AstroSat far-UV, soft X-ray, and hard ...X-ray data, along with (quasi-)simultaneous optical and X-ray data from the Las Cumbres Observatory and NICER, respectively. In the soft state, we detect soft X-ray and UV/optical excess components over and above the intrinsic accretion disk emission ( kT in ∼ 0.58 keV) and a steep X-ray power-law component. The soft X-ray excess is consistent with a high-temperature blackbody ( kT ∼ 0.79 keV), while the UV/optical excess is described by UV emission lines and two low-temperature blackbody components ( kT ∼ 3.87 and ∼0.75 eV). Employing continuum spectral fitting, we determine the BH spin parameter ( a = 0.77 ± 0.21), using the jet inclination angle of 64° ± 5° and a mass spanning 5–10 M ☉ . In the hard state (HS), we observe a significantly enhanced optical/UV excess component, indicating a stronger reprocessed emission in the outer disk. Broadband X-ray spectroscopy in the HS reveals a two-component corona, each associated with its reflection component, in addition to the disk emission ( kT in ∼ 0.19 keV). The softer coronal component dominates the bolometric X-ray luminosity and produces broader relativistic reflection features, while the harder component gets reflected far from the inner disk, yielding narrow reflection features. Furthermore, our analysis in the HS suggests a substantial truncation of the inner disk (≳51 gravitational radii) and a high disk density (∼10 20 cm −3 ).
We present multi-wavelength follow-up campaigns by the AstroSat CZTI and GROWTH collaborations in search of an electromagnetic counterpart to the gravitational wave event GW 170104. At the time of ...the GW 170104 trigger, the AstroSat CZTI field of view covered 50.3% of the sky localization. We do not detect any hard X-ray (>100 keV) signal at this time, and place an upper limit of , for a 1 s timescale. Separately, the ATLAS survey reported a rapidly fading optical source dubbed ATLAS17aeu in the error circle of GW 170104. Our panchromatic investigation of ATLAS17aeu shows that it is the afterglow of an unrelated long, soft GRB 170105A, with only a fortuitous spatial coincidence with GW 170104. We then discuss the properties of this transient in the context of standard long GRB afterglow models.
ABSTRACT AstroSat is a multi-wavelength satellite launched on 2015 September 28. The CZT Imager of AstroSat on its very first day of operation detected a long duration gamma-ray burst (GRB), namely ...GRB 151006A. Using the off-axis imaging and spectral response of the instrument, we demonstrate that the CZT Imager can localize this GRB correctly to about a few degrees, and it can provide, in conjunction with Swift, spectral parameters similar to those obtained from Fermi/GBM. Hence, the CZT Imager would be a useful addition to the currently operating GRB instruments (Swift and Fermi). Specifically, we argue that the CZT Imager will be most useful for the short hard GRBs by providing localization for those detected by Fermi and spectral information for those detected only by Swift. We also provide preliminary results on a new exciting capability of this instrument: the CZT Imager is able to identify Compton scattered events thereby providing polarization information for bright GRBs. GRB 151006A, in spite of being relatively faint, shows hints of a polarization signal at 100-300 keV (though at a low significance level). We point out that the CZT Imager should provide significant time resolved polarization measurements for GRBs that have fluence three times higher than that of GRB 151006A. We estimate that the number of such bright GRBs detectable by the CZT Imager is five to six per year. The CZT Imager can also act as a good hard X-ray monitoring device for possible electromagnetic counterparts of gravitational wave events.
PDF
