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•Spectrum impact on PV: reciprocal of the spectral factor vs. average photon energy.•Sensitivity of SF−1 to APE: m-Si, CIS, CdTe and a-Si (from lowest to highest).•Overcast ...conditions: spectral gains for m-Si, CIS, CdTe and especially for a-Si.•Clear days and high irradiance: low impact on spectral gains/losses (except a-Si).•Clear days and low irradiance: spectral losses in m-Si, CIS, CdTe and a-Si.
The outdoor performance of thin film technologies is not so satisfactorily understood as that of crystalline silicon. Despite all PV materials are influenced by the spectral irradiance, thin film PV modules are especially sensitive to it. Thus, the spectral factor (SF) is a useful index to quantify spectral gains or losses a PV module may experience under the actual spectrum when compared to the standard AM 1.5-G. This work is mainly aimed at looking into the dependence of the reciprocal of the spectral factor (SF−1) of four modules representative of four technologies – amorphous silicon (a-Si), cadmium telluride (CdTe), copper indium diselenide (CIS) and monocrystalline silicon (m-Si) – on the average photon energy (APE), an index that characterizes the spectrum shape. Results show that in general SF−1 increases as APE does. PV modules made of m-Si, CIS, CdTe and a-Si are ordered from lowest to highest dependence of the former parameter on the latter. Thus, figures of APE ranging from 1.79 to 1.92eV cause deviations on SF−1 – from the ideal ‘one’ of the AM 1.5-G – of some −25/15% for a-Si, but only of some −5/5% for m-Si. Correlations between figures of APE obtained in cloudy and fine weather imply that spectral gains – highly noticeable in a-Si – take place in overcast conditions, while clear days with high irradiance profiles exert a limited influence on the spectral behavior of the four considered technologies, with the exception of a-Si. Last, low levels of irradiance in clear days imply spectral losses in all the cases.
Brown adipose tissue (BAT) activity is induced when humans are exposed to cold. Therefore, cold exposure prior to the
F-FDG-PET/CT scan is used as a tool to quantify BAT. Several cooling protocols, ...including fixed and personalized ones are currently in use. The aim of the present study was to determine the effect of a new personalized cooling protocol where the shivering threshold was measured on a separate day, on BAT volume and activity in young adults. A total of 47 adults (
= 28 women) aged 22 ± 2 years participated in the study. We determined participants' shivering threshold (visually and self-reported) using a water perfused cooling vest in an air-conditioned cold room. 48-72 h later, participants wore the cooling vest set at ~4°C above the shivering threshold for 60 min prior to injection of
F-FDG and ~5°C above the shivering threshold for ~60 min after injection, until PET/CT scan. We quantified BAT following BARCIST 1.0 recommendations. We identified 40 participants (85%,
= 25 women) as PET+ and 7 (
= 3 women) as PET-. The PET+ group presented significantly higher BAT volume and activity than PET- group (all
< 0.05). PET+ women had higher BAT mean activity than PET+ men (SUV
: 5.0 ± 1.6 vs. 3.6 ± 0.9 g/ml respectively,
= 0.003), and there were no significant sex differences in BAT volume (
= 0.161). A total of 9 out of 47 participants did not shiver during the shivering threshold test. Our findings are similar to previous cold-stimulated human BAT studies; therefore, we conclude that our personalized cooling protocol is able to activate BAT in young adults.
•A MOLB-type SOFC with different biogas compositions is modeled.•Internal reforming of methane and water gas shift in the anode side are considered.•Changes in the SOFC according to the phenomena ...inside of them are assessed.•A new configuration for the MOLB-type geometry is proposed.•Temperature gradients effects in the new configuration are significant.
A mono-block-layer build type (MOLB-type) geometry, composed with trapezoidal cross-section channels for fuel and air, of solid oxide fuel cell (SOFC), is modeled in this study using a three dimensional computational fluid dynamics (CFD). The model is used to obtain the performance of the SOFC considering internal reforming of methane in the anode side with different biogas compositions. From the results obtained, a new configuration for the MOLB-type geometry is proposed. The model takes into account the mass transfer, heat transfer, species transport, chemical and electrochemical reactions, detailed comparisons of species concentration, temperature and electric fields inside the cell analyzed in the present study. Results show that the biogas from local sludge has the lower temperature gradient and more homogeneous current density distributions along of the fuel cell, on the other hand, with the new configuration proposed for the MOLB-type geometry the temperature distribution inside of the fuel cell has lower temperature gradients.
•This study investigated the influence of synthesis temperature on the properties of the BaFe12O19.•A correlation between synthesis temperature and crystal size was observed.•The optimum critical ...diameter (DC) to achieve single magnetic domains was identified.•The magnetic properties of the samples were characterized, revealing exceptional values for saturation magnetization (Ms), remanent magnetization (Mr), and coercivity (Hc) in the sample sintered at 1050 °C.
This study presents the synthesis and characterization of barium hexaferrite (BaFe12O19) powders via the Pechini method, employing controlled pH conditions (pH = 1) followed by sintering at temperatures ranging from 800 °C to 1150 °C. Structural and magnetic properties of the samples were investigated using various techniques, including Vibrating Sample Magnetometry, X-ray Diffractometry, and Scanning Electron Microscopy. Additionally,a theoretical analysis was conducted to determine the critical size required for achieving a single magnetic domain in the material. The results reveal a correlation between synthesis temperature and crystal size, ranging from 76 nm (at 800 °C) to 632 nm (at 1150 °C). Notably, samples sintered at 1050 °C exhibited exceptional magnetic properties, displaying a saturation magnetization (Ms) of 75.1 emu/g, a remanent magnetization (Mr) of 36.7 emu/g, and a coercivity (Hc) of 5.65 kOe. The particle size of these samples measured 327 nm, closely aligning with the critical diameter calculated for barium hexaferrite (378 nm) in this study. This optimal critical size was identified in sample sintered at 1050 °C, resulting in notably high coercivity values compared to those reported in previous literature. These findings highlight the significance of synthesis temperature control in tailoring the magnetic properties of barium hexaferrite, offering insights into optimizing its performance for various applications.
Previous works seem to agree in the higher mortality of cancer patients with COVID-19. Identifying potential prognostic factors upon admission could help identify patients with a poor prognosis.
We ...aimed to explore the characteristics and evolution of COVID-19 cancer patients admitted to hospital in a multicenter international registry (HOPE COVID-19). Our primary objective is to define those characteristics that allow us to identify cancer patients with a worse prognosis (mortality within 30 days after the diagnosis of COVID-19).
5838 patients have been collected in this registry, of whom 770 had cancer among their antecedents. In hospital mortality reached 258 patients (33.51%). The median was 75 years (65-82). Regarding the distribution by sex, 34.55% of the patients (266/770) were women. The distribution by type of cancer: genitourinary 238/745 (31.95%), digestive 124/745 (16.54%), hematologic 95/745 (12.75%). In multivariate regression analysis, factors that are independently associated with mortality at admission are: renal impairment (OR 3.45, CI 97.5% 1.85-6.58), heart disease (2.32, 1.47-3.66), liver disease (4.69, 1.94-11.62), partial dependence (2.41, 1.34-4.33), total dependence (7.21, 2.60-21.82), fatigue (1.84, 1.16-2.93), arthromialgias (0.45, 0.26-0.78), SatO2<92% (4.58, 2.97-7.17), elevated LDH (2.61, 1.51-4.69) and abnormal decreased Blood Pressure (3.57, 1.81-7.15). Analitical parameters are also significant altered.
In patients with cancer from the HOPE registry, 30-day mortality from any cause is high and is associated with easily identifiable clinical factors upon arrival at the hospital. Identifying these patients can help initiate more intensive treatments from the start and evaluate the prognosis of these patients.
Abstract
In this work, strontium hexaferrite (SrFe
12
O
19
) was prepared using two different methods, the solid-state reaction and the sol–gel pechini methods. In each case, the structural ...properties and microstructural features were analyzed in order to evaluate their influence on the photocatalytic activity of the strontium hexaferrite. In addition, the magnetic properties of each sample were also investigated. The analysis of the photocatalytic activity was done using methylene blue as a test dye. The results show that the fabrication method significantly impacts how the photocatalytic activity occurs. Firstly, the bandgap energy of the sample obtained by the solid-state reaction method turned out to be smaller than that obtained by the sol–gel pechini method. This behavior was attributed to the structural differences shown between the two samples. On the other hand, particle size also has a significant effect on photochemical reactions. However, smaller particle sizes make it difficult for photons to transport in the system, resulting in reduced photocatalytic activity. In this case, better results were obtained from the sample obtained from the solid-state reaction method.
Smart Cable-Driven Camera Robotic Assistant Rivas-Blanco, I.; Lopez-Casado, C.; Perez-del-Pulgar, C. J. ...
IEEE transactions on human-machine systems,
2018-April, 2018-4-00, Letnik:
48, Številka:
2
Journal Article
Recenzirano
This paper describes the mechanical design and a cognition system for a novel concept-of-camera robotic assistant. The system combines the advantages of intra-abdominal devices and autonomous camera ...navigation. The robotic assistant is composed of a magnetic intra-abdominal camera robot with two internal cable-driven degrees of freedom and an external robot that handles an external magnet. The intelligence of the robot is implemented in a cognitive architecture based on a long-term memory that stores the robot's knowledge and learning capabilities to improve the robot's behavior. The navigation strategy combines a reactive control based on instrument tracking and a proactive control based on predefined behaviors, depending on the actual state of the task. The robot's learning capabilities include a semantic customization, to adapt the camera's behavior to the surgeon's preferences, and reinforcement learning, to improve the camera navigation strategy. This paper details both the hardware implementation of the system and the software implementation in a robotic operating system architecture. The cognition system and the performance of the cable-driven mechanism have been validated with a set of in vitro experiments. Moreover, the camera robot has been evaluated through an in-vivo experiment in a pig.
Epidemiological studies assessing prenatal fluoride exposure and anthropometry at birth are scarce, inconsistent and with methodological limitations. The aim of this study was to evaluate ...associations between maternal urinary fluoride (MUF) at each trimester of pregnancy and birth weight and length in 536 mother-child pairs in the Early Life Exposures in Mexico to Environmental Toxicants (ELEMENT) cohort study. MUF (mg/L) was measured using microdiffusion/fluoride-specific electrode from at least one trimester of pregnancy. Non-linear associations were assessed through segmented regression models (MUF and birth weight Z-score) and we used linear regression models for MUF and birth length Z-score. Models were adjusted for potential confounders including urinary creatinine concentrations as a covariate. Non-creatinine adjusted MUF levels at each trimester of pregnancy were 0.81, 0.86, and 0.82 mg/L, mean concentrations for first, second and third trimester, respectively. For birth weight, we identified a MUF breakpoint at 0.99, 0.68 and 0.58 mg/L, for first, second and third trimester of pregnancy, respectively. In the first trimester, an increase of 1 mg/L in MUF concentrations ≥0.99 mg/L was associated with an increase in weight Z-score at birth (β = 0.79; 95% CI: 0.10, 1.48; p = 0.02). Second trimester MUF (≥0.68 mg/L) was marginally associated with birth weight decrease (β = −0.25; 95% CI: −0.55, 0.04; p = 0.09) and third trimester MUF (≥0.58 mg/L) was significantly associated with birth weight decrease (β = −0.33; 95% CI: −0.63, −0.03; p = 0.03). We observed a linear and significant association between MUF and Z-score of length at birth only for the first trimester of pregnancy (β = 0.55; 95% CI: 0.07, 1.04; p < 0.02). Prenatal fluoride exposure was associated with birthweight z-score with different susceptibility windows. Our findings reinforce the hypothesis that maternal fluoride exposure may affect birth anthropometry.
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•Salt is one of the main sources of fluoride exposure in Mexican population.•Fluoride exposure is linked to adverse fetal and maternal outcomes.•Maternal Fluoride (first trimester) was associated with birth weight increase.•Maternal Fluoride (third trimester) was associated with birth weight decrease.•Women should avoid sources of fluoride exposure during pregnancy.
Purpose
To validate the Barcelona-magnetic resonance imaging predictive model (BCN-MRI PM) for clinically significant prostate cancer (csPCa) in Catalonia, a Spanish region with 7.9 million ...inhabitants. Additionally, the BCN-MRI PM is validated in men receiving 5-alpha reductase inhibitors (5-ARI).
Materials and methods
A population of 2,212 men with prostate-specific antigen serum level > 3.0 ng/ml and/or a suspicious digital rectal examination who underwent multiparametric MRI and targeted and/or systematic biopsies in the year 2022, at ten participant centers of the Catalonian csPCa early detection program, were selected. 120 individuals (5.7%) were identified as receiving 5-ARI treatment for longer than a year. The risk of csPCa was retrospectively assessed with the Barcelona-risk calculator 2 (BCN-RC 2). Men undergoing 5-ARI treatment for less than a year were excluded. CsPCa was defined when the grade group was
≥
2.
Results
The area under the curve of the BCN-MRI PM in 5-ARI naïve men was 0.824 (95% CI 0.783–0.842) and 0.849 (0.806–0.916) in those receiving 5-ARI treatment,
p
0.475. Specificities at 100, 97.5, and 95% sensitivity thresholds were to 2.7, 29.3, and 39% in 5-ARI naïve men, while 43.5, 46.4, and 47.8%, respectively in 5-ARI users. The application of BCN-MRI PM would result in a reduction of 23.8% of prostate biopsies missing 5% of csPCa in 5-ARI naïve men, while reducing 25% of prostate biopsies without missing csPCa in 5-ARI users.
Conclusions
The BCN-MRI PM has achieved successful validation in Catalonia and, notably, for the first time, in men undergoing 5-ARI treatment.
Clinical outcomes after tricuspid surgery Rodríguez-Capitán, J.; Becerra-Muñoz, V. M.; Pérez-Villardón, B. ...
Herz,
09/2020, Letnik:
45, Številka:
6
Journal Article
Recenzirano
Background
The aim of our study was to assess the outcomes of surgical treatment for severe tricuspid regurgitation according to whether cardiac surgery had been performed before the tricuspid valve ...intervention.
Methods
Between 1996 and 2013, 201 consecutive patients with severe tricuspid regurgitation underwent tricuspid surgery at our center. Patients were classified according to whether or not they had undergone previous cardiac surgery, which 33% of the sample had. Perioperative as well as long-term morbidity and mortality were analyzed.
Results
Mean patient age was 62.3 years. 32.8% underwent suture annuloplasty, 41.3% underwent ring annuloplasty, 15.4% received a bioprosthesis, and 10.4% received a mechanical prosthesis. There were no significant differences in perioperative mortality between the group that had not undergone previous cardiac surgery and the group that had (12.7% vs. 17.9%, respectively;
p
= 0.32). The long-term mortality rate (median follow-up time: 53 months) was 43.3%. Long-term survival curves showed no significant differences between the two groups (
p
= 0.884), and previous cardiac surgery was not a predictive factor for long-term mortality (hazard ratio = 1.211;
p
= 0.521).
Conclusion
In a series of patients who underwent tricuspid valve surgery, no significant differences were observed in perioperative mortality or in long-term survival according to whether or not subjects had undergone previous cardiac surgery.
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