COVID-19 is a severe viral infection of the respiratory tract and has become a worldwide pandemic. Months after the initial infection several people report persistent limitations in daily life. ...Previous studies have identified body composition as a predictor of clinical progression in cases of COVID-19. However, body impedance measurements were limited to baseline and not repeated in serial measurements. In this study we analyzed the impact of a moderate oxygen-dependent COVID-19 infection on body composition during hospitalization.
We enrolled 12 consecutive patients hospitalized due to an oxygen-dependent SARS-CoV-2 infection. Body impedance analysis was performed within 24 h of admission and repeated on day 3 ± 1 as well as on the day of discharge. Endpoints were any significant changes in body composition.
Median age of enrolled patients was 70.6 years with a BMI of 30.8 kg/m2. Patients were hospitalized for 14 days. Median oxygen demand was 3 l/min, 2 patients required mechanical ventilation. Body water and fat remained unchanged during the study period. We observed a significant decrease of phase angle (−0.6, p < 0.01) and body cell mass (−2.3%, p < 0.01) with an increase in extracellular mass on day 3. Values returned to baseline along recovery.
We found a significant reduction in body cell mass and phase angle during the active infection with slow regression towards hospital discharge. Future studies are needed to clarify if nutrition and training programs during and after COVID-19 might limit these changes and have a positive impact on clinical course and rehabilitation.
•Particulate samples of common rocks show spectral changes with increasing phase angle.•Degree of particle transparency and sample surface roughness are the driving factors.•Microscopic roughness ...leads to monotonous reddening and Lommel–Seeliger scattering.•Ray-tracing simulations qualitatively reproduce the observed spectral changes.•Surface roughness may explain spececraft observations of phase reddening.
The visible reflectance spectrum of many Solar System bodies changes with changing viewing geometry for reasons not fully understood. It is often observed to redden (increasing spectral slope) with increasing solar phase angle, an effect known as phase reddening. Only once, in an observation of the martian surface by the Viking 1 lander, was reddening observed up to a certain phase angle with bluing beyond, making the reflectance ratio as a function of phase angle shaped like an arch. However, in laboratory experiments this arch-shape is frequently encountered. To investigate this, we measured the bidirectional reflectance of particulate samples of several common rock types in the 400–1000nm wavelength range and performed ray-tracing simulations. We confirm the occurrence of the arch for surfaces that are forward scattering, i.e. are composed of semi-transparent particles and are smooth on the scale of the particles, and for which the reflectance increases from the lower to the higher wavelength in the reflectance ratio. The arch shape is reproduced by the simulations, which assume a smooth surface. However, surface roughness on the scale of the particles, such as the Hapke and van Horn (Hapke, B., van Horn, H. 1963. J. Geophys. Res. 68, 4545–4570) fairy castles that can spontaneously form when sprinkling a fine powder, leads to monotonic reddening. A further consequence of this form of microscopic roughness (being indistinct without the use of a microscope) is a flattening of the disk function at visible wavelengths, i.e. Lommel–Seeliger-type scattering. The experiments further reveal monotonic reddening for reflectance ratios at near-IR wavelengths. The simulations fail to reproduce this particular reddening, and we suspect that it results from roughness on the surface of the particles. Given that the regolith of atmosphereless Solar System bodies is composed of small particles, our results indicate that the prevalence of monotonic reddening and Lommel–Seeliger-type scattering for these bodies results from microscopic roughness, both in the form of structures built by the particles and roughness on the surface of the particles themselves. It follows from the singular Viking 1 observation that the surface in front of the lander was composed of semi-transparent particles, and was smooth on the scale of the particle size.
Tuberculosis (TB) is a worldwide burden whose total control and eradication remains a challenge due to factors including false positive/negative diagnoses associated with the poor sensitivity of the ...current diagnostics in immune-compromised and post-vaccinated individuals. As these factors complicate both diagnosis and treatment, the early diagnosis of TB is of pivotal importance towards reaching the universal vision of a TB-free world. Here, an aptasensor for signaling an interferon gamma (IFN-γ) TB biomarker at low levels is reported. The aptasensor was assembled through gold-thiol interactions between poly(3,4-propylenedioxythiophene), gold nanoparticles, and a thiol-modified DNA aptamer specific to IFN-γ. The aptasensor sensitively detected IFN-γ in spiked pleural fluid samples with a detection limit of 0.09 pg/mL within a linear range from 0.2 pg/mL to 1.2 pg/mL. The good performance of the reported aptasensor indicates that it holds the potential for application in the early diagnosis of, in addition to TB, various diseases associated with IFN-γ release in clinical samples.
Several different tools have been developed to integrate the clinical and biochemical nutritional evaluations in critical care patients. Aims of this study were to evaluate the changes in the ...Bioelectrical Impedance Vector Analysis (BIVA) and ultrasonographic features of the diaphragm (DTee) and rectus femoris (RFCSA) during the first week of ICU stay.
Ninety-six adult mechanically ventilated patients enrolled within 24 h after the admission to the ICU (T1). RFCSA and diaphragm end-expiratory thickness were measured, as well as BIVA parameters. Anthropometric data and biochemical parameters were collected. The measurements were repeated on the 3rd (T3) and 7th (T7) days of ICU stay.
During the study period, the phase angle significantly decreased by 21%, reactance by 27%, and resistance by 11%. Both RFCSA and DTee significantly decreased, while neither were correlated to any BIVA parameter. DTee was considerably higher in survivors vs. non-survivors.
Body composition is significantly modified after one week of ICU stay. BIVA may be useful in the definition of hydration state, while it does not seem to track muscle mass. Different temporal trends of specific BIVA and muscle ultrasound parameters were found in patients with high or low severity of illness.
•Wind speed, solar radiation and temperature are investigated using wavelet analysis.•All the three time series used show significant correlation with annual period.•Wind energy and solar energy can ...play complementary role in power generation.•The research idea can be extended when designing energy project across regions.
In this paper, 10-year meteorological data observed at Taipei, Taiwan, from 2006 to 2015, are studied to investigate the inherent correlation between renewable resources. The data are investigated in the time-frequency space using wavelet analysis including wind speed, global solar radiation and air temperature. Through the wavelet transform of the time series, the related cross wavelet transform, wavelet coherence and phase angle are obtained. The results show that the wavelet power spectra exhibit prominent oscillations at annual and half-year periods for the three kinds of meteorological data, while some oscillations for other periods do not show a regular pattern. Wind speed spectrum is more irregular than the other two types of data due to climatic and geographic factors, whereas temperature has the most regular form. From the cross wavelet transform of data pairs, it is seen wind speed and solar radiation have an anti-phase correlation, implying that wind and solar energy can be used in complementary roles in electricity generation in this region. The results of wavelet analysis coincide with the variation trend of the monthly mean of the meteorological data over the 10-year period. Wavelet analysis is a robust tool for the oscillation characteristic study on time series data.
•Hand grip strength (HGS) is used in clinical practice and represents a popular marker of nutritional status.•Reference values for HGS in women according to body mass index (BMI) are potentially ...useful in both clinical and research fields.•The main predictors of HGS were weight and phase angle (PhA).•HGS and PhA variations could be used in a clinical setting to monitor nutritional status.
Hand grip strength (HGS) is frequently used in clinical practice, resulting in a potential marker of nutritional status. This study aimed to develop reference values of HGS in Italian women with different categories of body mass index (BMI). Additionally, the main predictors of HGS were identified.
A cross-sectional study was conducted in Italian women between ages 16 and 55 y with different categories of BMI at the Department of Clinical Medicine and Surgery, Federico II University Hospital, Naples Italy. The whole sample was divided into tertiles according to BMI: 15 to 17.29 kg/m2 (T1), 17.3 to 19.9 kg/m2 (T2), and 20 to 25 kg/m2 (T3). Anthropometry, bioimpedance analysis, and muscle strength by an HGS test were evaluated. The cut-off values for HGS were developed for all participants and stratified by age group. Finally, a multivariate linear regression analysis was performed to assess the main predictors of HGS.
A total of 529 women with a mean age of 23.2 ± 7.0 y and an average BMI of 18.9 ± 2.5 kg/m2 were analyzed. HGS was higher for the dominant hand than for the non-dominant hand in all BMI tertiles. On both sides, according to age groups, HGS increased with increasing age in T1 and T3, whereas it increased in the women between ages 20 and 30 y in T2 only. Multivariate linear regression analysis showed that predictors of HGS varied according to tertiles. Specifically, we found that body weight (R2 = 0.252) was the main predictor in T1, whereas phase angle (PhA) was the main determinant in both T2 (R2 = 0.240) and T3 (R2 = 0.216).
This study defined the normal reference values of HGS in Italian women with different BMI ranges, stratifying the sample group by age. Additionally, the main predictors of HGS were assessed for each BMI tertile. In primary malnutrition (T1), the main predictor of HGS was body weight, whereas in the other two tertiles (T2, T3), the PhA was the main predictor of HGS.
•No differences of appearance that are strongly indicative of temporal changes were found on Pluto or Charon.•Limits on temporal changes as a function of spatial scale and temporal interval are ...determined.•Contrast reversal and high-phase bright features that change in appearance with solar phase angle are identified.•Had plumes, analogous to those discovered on Triton, been active on the encounter hemispheres they would have been detected.•Several dark streak features that may be deposits from past plumes are identified.
A search for temporal changes on Pluto and Charon was motivated by (1) the discovery of young surfaces in the Pluto system that imply ongoing or recent geologic activity, (2) the detection of active plumes on Triton during the Voyager 2 flyby, and (3) the abundant and detailed information that observing geologic processes in action provides about the processes. A thorough search for temporal changes using New Horizons images was completed. Images that covered the same region were blinked and manually inspected for any differences in appearance. The search included full-disk images such that all illuminated regions of both bodies were investigated and higher resolution images such that parts of the encounter hemispheres were investigated at finer spatial scales. Changes of appearance between different images were observed but in all cases were attributed to variability of the imaging parameters (especially geometry) or artifacts. No differences of appearance that are strongly indicative of a temporal change were found on the surface or in the atmosphere of either Pluto or Charon. Limits on temporal changes as a function of spatial scale and temporal interval during the New Horizons encounter are determined. The longest time interval constraint is one Pluto/Charon rotation period (∼6.4 Earth days). Contrast reversal and high-phase bright features that change in appearance with solar phase angle are identified. The change of appearance of these features is most likely due to the change in phase angle rather than a temporal change. Had active plumes analogous to the plumes discovered on Triton been present on the encounter hemispheres of either Pluto or Charon, they would have been detected. The absence of active plumes may be due to temporal variability (i.e., plumes do occur but none were active on the encounter hemispheres during the epoch of the New Horizons encounter) or because plumes do not occur. Several dark streak features that may be deposits from past plumes are identified.
•Fatigue and electrochemical tests can be conducted simultaneously in a novel setup.•Fatigue crack can be recognized and monitored based on evolution of phase angle.•The established crack model is in ...good agreement with the experimental data.
The corrosion fatigue crack formation on drill steel was studied using electrochemical impedance spectroscopy in a novel experimental setup, where the fatigue testing and electrochemical measurement could be conducted simultaneously. Results show that the corrosion fatigue crack formation in 3.5 % NaCl solution can be real time monitored based on changes in phase angle over time, i.e., the evolution of the peak value of phase shift angle and the frequency where the phase shift angle peak appears. A corrosion fatigue crack impedance model was established and it is found that modeling results are in good consistency with the experimental data.
In this study, we demonstrated the usefulness of proton conducting electrolytes (such as ammonium thiocyanate (NH4SCN) and ammonium nitrate (NH4NO3)) for electrochemical energy storage devices using ...activated carbon (AC) as the electrode material. The cyclic voltammetry analysis revealed the presence of rectangular shaped cyclic voltammograms indicating the presence of electrical double layer capacitance in AC electrode using NH4SCN and NH4NO3 electrolytes. The mechanism of charge-storage in AC electrode using the proton conducting electrolytes has been studied in detail using electrochemical impedance spectroscopy (Nyquist and Bode plots). The galvanostatic charge-discharge analysis revealed that a maximum specific capacitance of AC electrode using NH4SCN and NH4NO3 electrolytes was found to be 136.75 mF cm−2 and 113.38 mF cm−2 at a current density of 0.5 mA cm−2. This study would open a new avenue for the use of ammonium based proton conducting electrolytes for supercapacitor applications.
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•Proton conducting electrolytes are examined for supercapacitor application.•Ammonium thiocyanate shows better performance compared to the ammonium nitrate.•Specific capacitance of 136.75 mF cm−2 is obtained using ammonium thiocyanate.•The charge-storage mechanism is discussed via Nyquist and Bode phase angle plot.
The ultrasonic interferometer manometer (UIM) is an apex level primary pressure standard for Pascal realization established at National Physical Laboratory India (NPLI). The performance of UIM has ...been evaluated from time to time by participation in key comparisons, calibration and measurement capabilities (CMC) and publications in reputed international metrology journals. The pressure is measured using time of flight technique at 44 different frequencies in ultrasonic range and the phase measurement. The phase measurement combined with the time of flight measurement using the exact fractional algorithm provides highly accurate column length hence respective pressure values. The combined process helps in lowering the uncertainty in real experimental conditions. Recently, we have also changed UIM software from tbasic to window based program with the same algorithm which provides a column length measurement study. A detailed study was carried out for variation of fringe counts or oscillations with varying pressure. Experimental and theoretical calculation for both resolution and pressure dependent part has been carried out for uncertainties involves the physical parameters. The uncertainties in lower pressure range, i.e., between 1 Pa and 1000 Pa were varying equal or sometimes higher than the theoretical resolution value 0.0092 Pa (k = 2) because of environmental conditions like vibration, temperature, atmospheric pressure, and humidity whereas for higher pressure range, i.e., 1000 Pa to 130 kPa the uncertainties were either close or smaller than the pressure dependent theoretical uncertainty value, i.e. 7.2 × 10−6 of the reading.
•We report state of art primary pressure standards with ppm level of uncertainties in measurement.•The experimental and theoretical expanded relative uncertainties at k = 2 are 5.6 ppm and 7.2 ppm, respectively.•The amplitude and wavelength of the received echo varies inversely with pressure/column of length.•Experimental as well as theoretical uncertainties are in close agreement in the range of 1 Pa–130 kPa.•The UIM shows long term stability in pressure measurement with 7.2 ppm of uncertainty since last 36 years.
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