scholarly journals New wavelength calibration of the HARPS spectrograph

2019 ◽  
Vol 629 ◽  
pp. A27 ◽  
Author(s):  
A. Coffinet ◽  
C. Lovis ◽  
X. Dumusque ◽  
F. Pepe
Keyword(s):  
Radial Velocity ◽  
Frequency Comb ◽  
Light Emitting Diode ◽  
Laser Frequency ◽  
Wavelength Calibration ◽  
Light Emitting ◽  
Before And After ◽  
Doppler Spectroscopy ◽  
One Year ◽  
The One

Context. Doppler spectroscopy has been used in astronomy for more than 150 yr. In particular, it has permitted us to detect hundreds of exoplanets over the past 20 yr, and the goal today of detecting Earth-like planets requires a precision around 0.1 m s−1 or better. Doppler spectroscopy has also been and will be of major importance for other studies such as the variability of fundamental constants and cosmological studies. For all these applications, it is crucial to have the best possible wavelength calibration. Despite the fact that the HARPS spectrograph has been operational at the 3.6-m ESO telescope for more than 15 yr, and that it provides among the most precise Doppler measurements, improvements are still possible. One known problem, for instance, is the non-fully regular block-stitching of the charge-coupled devices (CCDs), which in some cases introduces one-year period parasitic signals in the measured radial velocity. Aims. The aim of the presented work is to improve the wavelength calibration of the HARPS spectrograph to push further its planet-detection capabilities. Methods. The properties of the CCD stitching-induced pixel-size anomalies were determined with light-emitting-diode (LED) flat-field frames, and then a physical, gap-corrected map of the CCDs is used for the fitting model of the spectral orders. We also used a new thorium line list, based on much higher-accuracy measurements than the one used up to now. We derive new wavelength solutions for the 15 yr of HARPS data, both before and after the fibre upgrade that took place in 2015. Results. We demonstrate that we do indeed correct the gap anomalies by computing the wavelength solutions of laser frequency comb exposures, known to have a very low dispersion, both with and without taking the gap correction into account. By comparing the rms of the most stable stars of the HARPS sample, we show that we globally decrease the radial velocity (RV) dispersion of the data, especially for the data acquired after the change of fibres of 2015. Finally, the comparative analysis of several individual systems shows that we manage to attenuate the periodogram power at one year in most cases. The analysis of the RVs derived from individual stellar lines also shows that we indeed correct the stitching-induced RV variation. Conclusions. This improved calibration of the HARPS spectrograph allows to go deeper in the search for low-amplitude radial-velocity signals. This new calibration process will be further improved by combining the thorium calibration spectra with laser frequency comb and Fabry–Perot calibration spectra, and this will not only be used for HARPS but notably also for HARPS-N and the new ESPRESSO spectrograph.

scholarly journals Real-World Experience of the One-Year Efficacy of Rifaximin Add-On to Lactulose Is Superior to Lactulose Alone in Patients with Cirrhosis Complicated with Recurrent Hepatic Encephalopathy in Taiwan

2021 ◽  
Vol 11 (6) ◽  
pp. 478
Author(s):  
Ching Chang ◽  
Chien-Hao Huang ◽  
Hsiao-Jung Tseng ◽  
Fang-Chen Yang ◽  
Rong-Nan Chien
Keyword(s):  
Hepatic Encephalopathy ◽  
Real World ◽  
Ammonia Level ◽  
Decompensated Cirrhosis ◽  
Control Group ◽  
Multivariable Logistic Regression Model ◽  
Before And After ◽  
One Year ◽  
The One ◽  
Serum Ammonia

Background: Hepatic encephalopathy (HE), a neuropsychiatric complication of decompensated cirrhosis, is associated with high mortality and high risk of recurrence. Rifaximin add-on to lactulose for 3 to 6 months is recommended for the prevention of recurrent episodes of HE after the second episode. However, whether the combination for more than 6 months is superior to lactulose alone in the maintenance of HE remission is less evident. Therefore, the aim of this study is to evaluate the one-year efficacy of rifaximin add-on to lactulose for the maintenance of HE remission in Taiwan. Methods: We conducted a real-world single-center retrospective cohort study to compare the long-term efficacy of rifaximin add-on to lactulose (group R + L) versus lactulose alone (group L, control group). Furthermore, the treatment efficacy before and after rifaximin add-on to lactulose was also analyzed. The primary endpoint of our study was time to first HE recurrence (Conn score ≥ 2). All patients were followed up every three months until death, and censored at one year if still alive. Results and Conclusions: 12 patients were enrolled in group R + L. Another 31 patients were stratified into group L. Sex, comorbidity, ammonia level, and ascites grade were matched while age, HE grade, and model for end-stage liver disease (MELD) score were adjusted in the multivariable logistic regression model. Compared with group L, significant improvement in the maintenance of HE remission and decreased episodes and days of HE-related hospitalizations were demonstrated in group R + L. The serum ammonia levels were significantly lower at the 3rd and 6th month in group 1. Concerning changes before and after rifaximin add-on in group R + L, mini-mental status examination (MMSE), episodes of hospitalization, and variceal bleeding also improved at 6 and 12 months. Days of hospitalization, serum ammonia levels also improved at 6th month. Except for concern over price, no patients discontinued rifaximin due to adverse events or complications. The above results provide evidence for the one-year use of rifaximin add-on to lactulose in reducing HE recurrence and HE-related hospitalization for patients with decompensated cirrhosis.

scholarly journals Traceability of laser frequency/wavelength calibration through the frequency comb at Inmetro

2016 ◽  
Vol 733 ◽  
pp. 012058 ◽  
Author(s):  
I L M Silva ◽  
I B Couceiro ◽  
M A C Torres ◽  
P A Costa ◽  
H P H Grieneisen
Keyword(s):  
Frequency Comb ◽  
Laser Frequency ◽  
Wavelength Calibration

Reactivity of bilirubin photoisomers on the measurement of direct bilirubin using vanadic acid method

2017 ◽  
Vol 55 (2) ◽  
pp. 296-298
Author(s):  
Hitoshi Okada ◽  
Susumu Itoh ◽  
Shohei Kawamoto ◽  
Miyo Ozaki ◽  
Takashi Kusaka
Keyword(s):  
High Performance ◽  
Light Emitting Diode ◽  
Direct Bilirubin ◽  
Acid Oxidation ◽  
Albumin Solution ◽  
Light Emitting ◽  
Oxidation Method ◽  
Before And After ◽  
Vanadic Acid ◽  
Human Serum Albumin Solution

Objective Investigation of the reactivity of fractions of bilirubin photoisomers with the vanadic acid oxidation method. Methods Bilirubin photoisomers were prepared by irradiating a bilirubin/human serum albumin solution with blue light emitting diode. Direct bilirubin and bilirubin fractions were measured using the vanadic acid oxidation method and high-performance liquid chromatography in the sample before and after irradiation. Results Direct bilirubin was increased in the solution containing bilirubin photoisomers. ( EE)-/( EZ) -cyclobilirubin-IXα and ( ZE)-/( EZ)-bilirubin-IXα completely disappeared after the addition of vanadic acid. Conclusion Bilirubin photoisomers reacted as direct bilirubin in the vanadic acid oxidation method.

Robot-Asssisted Laparoscopic Radical Prostatectomy (Ralp). Oncological and Functional Findings after 90 Cases

2009 ◽  
Vol 76 (2) ◽  
pp. 87-89 ◽  
Author(s):  
C. Giberti ◽  
M. Schenone ◽  
P. Cortese ◽  
F. Gallo ◽  
E Gastaldi ◽  
...  
Keyword(s):  
Disease Free Survival ◽  
Functional Results ◽  
Modern Technology ◽  
Nerve Sparing ◽  
Number Of Patients ◽  
Before And After ◽  
Disease Free Survival Rate ◽  
One Year ◽  
The One

The RALP is the most modern technology available for the treatment of intracapsular prostate cancer (CaP), which can produce a shorter learning curve and better results than the traditional techniques. Methods Between March 2005 and March 2008, 90 patients (64.3 ys, range 52–71) with intracapsular CaP underwent RALP at our institute. Before surgery the patients underwent routine examinations and filled in IIEF, IPSS and EORTC-QLQC30/PR 25 questionnaires. Patients were followed up with PSA assay, physical examination and compilation of the questionnaires. Median follow-up was 12.5 months (range 1–35 months). Results Mean operative time was 230 min. Discharge and catheter removal were at day 7.4 and 8.2, respectively, after surgery. Pathological staging reported pT2 and pT3 in 57 (63%) and 33 patients (37%), respectively. Positive surgical margins were assessed in 30 patients (33%), particularly 8.7% in pT2 tumors. The one-year biochemical disease-free survival rate was 90%. Regarding the functional results, 81 patients (90%) were perfectly continent while a mild and a moderate incontinence were reported in 7 (8%) and 2 (2%) patients, respectively. Mean IPSS score decreased from 8 to 4; among the patients who underwent bilateral nerve sparing RALP and no adjuvant therapy, 31 (70.4%) reported satisfactory sexual intercourses. Concerning postoperative quality of life, mean EORTC-QLQC30/PR 25 questionnaires scores were very similar before and after RALP. Conclusions After 90 cases of RALP the oncological and functional results are definitely promising. However, a wider number of patients and a greater follow-up are needed to confirm these data particularly as regards the functional results.

scholarly journals A laser frequency comb that enables radial velocity measurements with a precision of 1 cm s-1

Nature ◽  
2008 ◽  
Vol 452 (7187) ◽  
pp. 610-612 ◽  
Author(s):  
Chih-Hao Li ◽  
Andrew J. Benedick ◽  
Peter Fendel ◽  
Alexander G. Glenday ◽  
Franz X. Kärtner ◽  
...  
Keyword(s):  
Radial Velocity ◽  
Frequency Comb ◽  
Laser Frequency ◽  
Velocity Measurements

Collagen metabolites in the prediction of response to GH therapy in short children

1997 ◽  
pp. 621-625 ◽  
Author(s):  
P Tapanainen ◽  
M Knip ◽  
L Risteli ◽  
L Kemppainen ◽  
ML Kaar ◽  
...  
Keyword(s):  
Bone Age ◽  
Type I ◽  
Gh Therapy ◽  
Gh Treatment ◽  
Type I Procollagen ◽  
Short Children ◽  
Before And After ◽  
The Absolute ◽  
One Year ◽  
The One

To evaluate the role of collagen metabolites in the prediction of the response to GH treatment we measured the serum concentrations of the C-terminal propeptide of type I procollagen (PICP) and the N-terminal propeptide of type III procollagen (PIIINP) with specific RIAs in 35 short children (16 boys) before and after 5 days, 5 weeks and 3 months of GH therapy. The mean age of the children was 10.3 years (range 1.9-16.4 years) and the bone age ranged from 1.2 to 12.5 years (mean 7.6 years). The initial mean relative height (RH) was -3.6 SDS (range -6.6 to -2.4 S.D.). Nineteen children were found to have GH deficiency (GHD; peak GH responses in two pharmacological tests < 10 micrograms/l), while the remaining 16 were considered to have undefined short stature (USS). The children were treated with recombinant human GH (0.1 U/kg given subcutaneously at bedtime 6-7 times/week). The increases in RHI over the first 6 and 12 months of therapy were used as response measures. There was already a significant increase (P < 0.001) in both the serum PICP and PIIINP levels at 5 days, and the concentrations continued to rise up to 3 months, PICP levels rising less than the PIIINP levels. In the whole group the RHI over 6 months correlated most strongly with the absolute PICP concentrations at 3 months (rS = 0.59; P < 0.05), while the absolute PIIINP concentrations at 3 months showed the strongest relation to the one year RHI (rS = 0.69; P < 0.001). In the GHD group the 6 month RHI was most strongly related to the absolute PICP concentration at 3 months (rS = 0.59; P < 0.05). In the USS group the absolute PICP concentrations at 3 months correlated most strongly with the one year RHI (rS = 0.82; P < 0.01). Significant correlations were also observed between the absolute PIIINP levels at 3 months and the 6 month RHI (rS = 0.60; P < 0.05) and 12 month RHI (rS = 0.76; P < 0.01) in this group. These results show that GH therapy results in an unequivocal increase in circulating concentrations of PICP and PIIINP. The serum PICP and PIIINP concentrations may be of value in the prediction of the long-term response to GH therapy.

scholarly journals Data Communication Security Issues of Wi-Fi over Li-Fi

2019 ◽  
Vol 8 (3) ◽  
pp. 1977-1981
Keyword(s):  
Light Emitting Diode ◽  
Denial Of Service ◽  
Data Communication ◽  
Electrical Signal ◽  
Visible Light Communications ◽  
Light Emitting ◽  
Security Issues ◽  
The One ◽  
Audio Video ◽  
Led Lights

Visible Light Communications (VLC) system is called Light Fidelity One such example, analog data is passed to a LED (Light-Emitting Diode) bulb (using signal processing technology), after that it transmits data (which is implanted in its beam) to the detector or photodiode. The small commutes in the brisk feeble of LED bulbs is modulated by the receiver circuit into electrical signal. The signal is then reversed into a duplex data runnel that could be recognized in the same way that of audio, video and web programs that run on devices that has internet enabled. Wi-Fi is vulnerable to breaches involving various security issues such as Rouge Access Points, Denial of Service, Wireless Trespasser, Data Interruption, End point attacks etc. To overcome such restrictions, this paper proposes application level substructure for data communication using Li-Fi (Light Fidelity) Technology. By using LED lights as a transmission medium, the indoor wireless communication is achieved in much faster rate than the one WiFi (Wireless Fidelity) can provide.

scholarly journals Lifetime and optical analyses of LED lamps

2021 ◽  
Vol 40 (1) ◽  
Author(s):  
Emerson Roberto Santos ◽  
Hélio Akira Furuya ◽  
Elvo Calixto Burini Junior
Keyword(s):  
Light Emitting Diode ◽  
The Other ◽  
Optical Characteristics ◽  
Integrating Sphere ◽  
Initial Moment ◽  
Direct Relation ◽  
Light Emitting ◽  
Elapsed Time ◽  
The One

In this study, optical and lifetime analyses of commercial light-emitting diode (LED) lamps were carried out with the objective to better understand these characteristics. Lamps of different manufacturers and powers were used: Ourolux of 9 watts, Kian of 9 watts, Black+Decker of 9 watts, FLC of 8 watts, Galaxy of 7 watts and Brilia of 7 watts. These LED lamps remained on by 24 hours/day for 4,291.16 hours. Illuminance measurements were analyzed once a week by each lamp inside the integrating sphere with a sensor of lux meter coupled. Results showed decrease of illuminance by elapsed time, due to the degradation. Results of the illuminance obtained between the initial moment of the experiment and the final one were calculated, revealing degradation of 19% to Ourolux, 20% to FLC, 26% to Black+Decker, 28% to Kian, 29% to Galaxy and 33% to Brilia. This study suggests that the diffusers can have different transmittance values interfering on the illuminance, since the FLC LED lamp presented illuminance with highest values than the other LED lamps tested with similar electrical and optical characteristics. This experiment showed that the nominal power of the LED lamp has no direct relation to the illuminance and, comparing the lifetime, the LED lamp manufactured by Black+Decker was the only one to reach 5,521 hours, that is a lifetime much shorter than the one described at the packages (25,000 hours) for all LED lamps tested

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