We report a high-energy picosecond optical parametric generator/amplifier (OPG/A) based on a MgO:PPLN crystal pumped by a fiber master-oscillator-power-amplifier (MOPA) employing direct amplification. An OPG tuning range of 1450-3615 nm is demonstrated with pulse energies as high as 2.6 μJ (signal) and 1.2 μJ (idler). When seeded with a ~100 MHz linewidth diode laser, damage-limited pulse energies of 3.1 μJ (signal) and 1.3 μJ (idler) have been achieved and the signal pulse time-bandwidth product is improved to ~2 times transform-limited. When seeded with a 0.3 nm-bandwidth filtered amplified spontaneous emission source, crystal damage is avoided and maximum pulse energies of 3.8 μJ (signal) and 1.7 μJ (idler) are obtained at an overall conversion efficiency of 45%.
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http://dx.doi.org/10.1364/OE.23.012613 | DOI Listing |
H*10 neutron dosimetry (unlike gamma dosimetry), requires consideration of neutron energy spectra due to the 20× variation of the weight factor over the thermal-to-fast energy range, as well as the neutron radiation field dose rates ranging from cosmic, ~.01 μSv h-1 levels to commonly encountered ~10-200 μSv h-1 in nuclear laboratories/processing plants, and upwards of 104 Sv h-1 in nuclear reactor environments. This paper discusses the outcome of the comparison of spectrum-weighted neutron dosimetry covering thermal-to-fast energy using the novel H*-TMFD spectroscopy-enabled sensor system in comparison with measurements using state-of-the-art neutron dosimetry systems at SRNS-Rotating Spectrometer (ROSPEC), and non-spectroscopic Eberline ASP2E ("Eberline") and Ludlum 42-49B ("Ludlum") survey instrumentation.
View Article and Find Full Text PDFPhys Eng Sci Med
January 2025
School of Biological Science and Medical Engineering, Beihang University, 37 Xueyuan Road, Haidian District, Beijing, 100191, China.
Extracorporeal shock wave therapy (ESWT) achieves its therapeutic purpose mainly through the biological effects produced by the interaction of shock waves with tissues, and the accurate measurement and calculation of the mechanical parameters of shock waves in tissues are of great significance in formulating the therapeutic strategy and evaluating the therapeutic effect. This study utilizes the approach of implanting flexible polyvinylidene fluoride (PVDF) vibration sensors inside the tissue-mimicking phantom of various thicknesses to capture waveforms at different depths during the impact process in real time. Parameters including positive and negative pressure changes (P, P), pulse wave rise time ([Formula: see text]), and energy flux density (EFD) are calculated, and frequency spectrum analysis of the waveforms is conducted.
View Article and Find Full Text PDFAnal Bioanal Chem
January 2025
Center for Applied Geoscience, Department of Geosciences, Eberhard Karls University Tübingen, Tübingen, Germany.
Aminopolyphosphonates (APPs) are widely used as chelating agents, and their increasing release into the environment has raised concerns due to their transformation into aminomethylphosphonic acid (AMPA) and glyphosate, compounds of controversial environmental impact. This transformation highlights the urgent need for detailed studies under controlled conditions. Despite the availability of various methods for quantifying individual aminopolyphosphonates and aminomonophosphonates, a green, low-cost approach for the simultaneous quantification of APPs and their transformation products in laboratory experiments has been lacking.
View Article and Find Full Text PDFJ Appl Physiol (1985)
January 2025
Department of Anatomy, Dalian Medical University, Dalian, Liaoning, China.
Exercise in heart failure with preserved ejection fraction (HFpEF) remains a hot topic, although current treatment strategies have not been shown to improve the long-term prognosis of HFpEF. Previous studies have mostly focused on the roles of endurance training, the mechanisms underlying long-term voluntary exercise have not been elucidated. The purpose of the present analysis was to evaluate alterations in cardiac function in HFpEF mice (HFpEF-Sed) after 6 weeks of voluntary running (HFpEF-Ex), investigate mechanisms, and compare the effects with fluoxetine (HFpEF-FLX).
View Article and Find Full Text PDFPhotosynth Res
January 2025
Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Leninskie Gory, Moscow, Russia, 119991.
The femtosecond dynamics of energy transfer from light-excited spirilloxanthin (Spx) to bacteriochlorophyll (BChl) a in the reaction centers (RCs) of purple photosynthetic bacteria Rhodospirillum rubrum was studied. According to crio-electron microscopy data, Spx is located near accessory BChl a in the B-branch of cofactors. Spx was excited by 25 fs laser pulses at 490 nm, and difference absorption spectra were recorded in the range 500-700 nm.
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