The assay of adenosine 5′-triphosphate extracted from salt-marsh microbiota

1981 ◽  
Vol 27 (6) ◽  
pp. 633-635 ◽  
Author(s):  
L. Harold Stevenson ◽  
Charles A. Wilson ◽  
Thomas H. Chrzanowski

The light-emitting reaction of firefly luciferin and luciferase is a common ingredient in the quantification of adenosine triphosphate (ATP) extracted from the microbiota of environmental samples. Both portions of the light-emission phase of the luciferase reaction, the primary flash within 3 s of mixing and the secondary decay in the luminescence following the flash, have been used to quantify extracted ATP. However, the magnitude of the secondary phase is influenced by nucleotides other than ATP. The impact of this influence on the quantification of ATP was studied in samples collected from the water covering a salt marsh. Analysis by integration of the secondary decay portion of the emission yielded values of ATP per cubic metre that were consistently higher than those obtained by peak height analysis of the same extracts. Assays using the integration technology resulted in values that were up to 8 [Formula: see text] times higher than corresponding values determined by peak height analysis in unfractionated samples (total microbial biomass) and up to 16 [Formula: see text] times higher in water that had been prefiltered with a 1.0 μm filter (bacterial biomass).

2020 ◽  
Author(s):  
FABIENNE LECOMTE ◽  
Elise Thecua ◽  
Laurine Ziane ◽  
Pascal Deleporte ◽  
Alain Duhamel ◽  
...  

BACKGROUND Neonatal jaundice is a very common condition occurring in 60–80% of all healthy term and late preterm neonates. In the newborn and especially in premature infants, the liver, which is still immature, is unable to eliminate the full amount of bilirubin. In the majority of cases, neonatal jaundice resolves spontaneously and causes no harm; however, in some babies, significant hyperbilirubinemia can develop. Bilirubin then accumulates in the blood and when too high, it can then lead to a serious neurological disease: kernicterus jaundice. Phototherapy is an effective therapy for jaundice and ideal phototherapy device should have a broad light emission surface, in order to cover the maximum of the body surface in the horizontal plane, it should generate no or little heat and provide a wavelength and light intensity optimal (420-490nm and ≥ 30µw / cm²/nm) OBJECTIVE The aim of the study is to investigate the feasibility, safety and level of satisfaction of parents and healthcare team with one innovative device for phototherapy, BUBOLight®, to which luminous textile have been incorporated in a sleeping bag. BUBOLight® emits homogeneous and stable light with a wavelength of 445 nm, for an irradiance of 3.5 mW/cm². It is easy to use and allows to carry out the phototherapy in the arms of the parents, thus preserving the parent–infant bonding. The primary end point of the study is to evaluate the safety of the BUBOLight® phototherapy device as an alternative to conventional hospital phototherapy under the usual conditions for the management of newborns jaundice. Secondary end points are the incidence of side effects (diarrhea, dehydration, skin lesions, temperature) related to phototherapy, evolution of blood bilirubin rate, perceptions of the parents and health team with the use of the device and the impact of the device on parent-child interactions and child comfort. METHODS The trial is an interventional, exploratory, simple group, non-randomized and single center (Lille Hospital) study. Ten to fifteen newborns and their parents will be included to obtain evaluable data from 10 parent-newborn pairs. Newborns more than 2500g of birth weight and born at greater than or equal to 37 weeks of gestation that required phototherapy according to the guidelines of the National Institute For Health and Clinical Excellence will receive one session of 4 hours of illumination. Bilirubin seric and transcutaneous levels were taken at the start and 2 hours after the end of phototherapy. Axillary temperature, heart rate and oxygen saturation will be measured at the beginning and during phototherapy. Number of subjects is therefore not calculated on the basis of statistical assumptions. The objective is to obtain a minimum proportion of 90% of the newborns included (i.e. 9 out of 10) who have been able to undergo 4-hours phototherapy treatment without unacceptable and unexpected toxicities. We will calculate the mean, median, quartiles, minimum and maximum of the quantitative parameters and the frequency of the qualitative parameters. The rate of patients with no unacceptable and unexpected toxicities (primary endpoint) will be calculated. RESULTS First patient is expected to be included at the end of 2020 and clinical investigations are planned until June 2021. The final results of this study are expected to be available at the end of 2021 CONCLUSIONS This trial aims to evaluate the safety and feasibility of a new phototherapy device based on light emitting fabrics for the treatment of newborn jaundice. The objective of this new system if, it is effective, to improve the humanization of newborn care avoiding the mother-and-child separation. CLINICALTRIAL ClinicalTrials.gov NCT04365998; https://clinicaltrials.gov/ct2/show/NCT04365998


Author(s):  
Yoav Weizman ◽  
Ezra Baruch

Abstract In recent years, two new techniques were introduced for flip chip debug; the Laser Voltage Probing (LVP) technique and Time Resolved Light Emission Microscopy (TRLEM). Both techniques utilize the silicon’s relative transparency to wavelengths longer than the band gap. This inherent wavelength limitation, together with the shrinking dimensions of modern CMOS devices, limit the capabilities of these tools. It is known that the optical resolution limits of the LVP and TRLEM techniques are bounded by the diffraction limit which is ~1um for both tools using standard optics. This limitation was reduced with the addition of immersion lens optics. Nevertheless, even with this improvement, shrinking transistor geometry is leading to increased acquisition time, and the overlapping effect between adjacent nodes remains a critical issue. The resolution limit is an order of magnitude above the device feature densities in the < 90nm era. The scaling down of transistor geometry is leading to the inevitable consequence where more than 50% of the transistors in 90nm process have widths smaller than 0.4um. The acquisition time of such nodes becomes unreasonably long. In order to examine nodes in a dense logic cuicuit, cross talk and convolution effects between neighboring signals also need to be considered. In this paper we will demonstrate the impact that these effects may have on modern design. In order to maintain the debug capability, with the currently available analytical tools for future technologies, conceptual modification of the FA process is required. This process should start on the IC design board where the VLSI designer should be familiar with FA constraints, and thus apply features that will enable enhanced FA capabilities to the circuit in hand during the electrical design or during the physical design stages. The necessity for reliable failure analysis in real-time should dictate that the designer of advanced VLSI blocks incorporates failure analysis constraints among other design rules. The purpose of this research is to supply the scientific basis for the optimal incorporation of design rules for optical probing in the < 90nm gate era. Circuit designers are usually familiar with the nodes in the design which are critical for debug, and the type of measurement (logic or DC level) they require. The designer should enable the measurement of these signals by applying certain circuit and physical constraints. The implementation of these constraints may be done at the cell level, the block level or during the integration. We will discuss the solutions, which should be considered in order to mitigate tool limitations, and also to enable their use for next generation processes.


Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2303
Author(s):  
Silvana De Iuliis ◽  
Roberto Dondè ◽  
Igor Altman

The application of pyrometry to retrieve particle temperature in particulate-generating flames strictly requires the knowledge of the spectral behavior of emissivity of light-emitting particles. Normally, this spectral behavior is considered time-independent. The current paper challenges this assumption and explains why the emissivity of oxide nanoparticles formed in flame can change with time. The suggested phenomenon is related to transitions of electrons between the valence and conduction energy bands in oxides that are wide-gap dielectrics. The emissivity change is particularly crucial for the interpretation of fast processes occurring during laser-induced experiments. In the present work, we compare the response of titania particles produced by a flame spray to the laser irradiation at two different excitation wavelengths. The difference in the temporal behavior of the corresponding light emission intensities is attributed to the different mechanisms of electron excitation during the laser pulse. Interband transitions that are possible only in the case of the laser photon energy exceeding the titania energy gap led to the increase of the electron density in the conduction band. Relaxation of those electrons back to the valence band is the origin of the observed emissivity drop after the UV laser irradiation.


Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Shaoni Kar ◽  
Nur Fadilah Jamaludin ◽  
Natalia Yantara ◽  
Subodh G. Mhaisalkar ◽  
Wei Lin Leong

Abstract Perovskite semiconductors have experienced meteoric rise in a variety of optoelectronic applications. With a strong foothold on photovoltaics, much focus now lies on their light emission applications. Rapid progress in materials engineering have led to the demonstration of external quantum efficiencies that surpass the previously established theoretical limits. However, there remains much scope to further optimize the light propagation inside the device stack through careful tailoring of the optical processes that take place at the bulk and interface levels. Photon recycling in the emitter material followed by efficient outcoupling can result in boosting external efficiencies up to 100%. In addition, the poor ambient and operational stability of these materials and devices restrict further commercialization efforts. With best operational lifetimes of only a few hours reported, there is a long way to go before perovskite LEDs can be perceived as reliable alternatives to more established technologies like organic or quantum dot-based LED devices. This review article starts with the discussions of the mechanism of luminescence in these perovskite materials and factors impacting it. It then looks at the possible routes to achieve efficient outcoupling through nanostructuring of the emitter and the substrate. Next, we analyse the instability issues of perovskite-based LEDs from a photophysical standpoint, taking into consideration the underlying phenomena pertaining to defects, and summarize recent advances in mitigating the same. Finally, we provide an outlook on the possible routes forward for the field and propose new avenues to maximally exploit the excellent light-emitting capabilities of this family of semiconductors.


Catalysts ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 624
Author(s):  
Sripriya Dharwadkar ◽  
Linlong Yu ◽  
Gopal Achari

Sulfolane is an emerging industrial pollutant detected in the environments near many oil and gas plants in North America. So far, numerous advanced oxidation processes have been investigated to treat sulfolane in aqueous media. However, there is only a few papers that discuss the degradation of sulfolane using photocatalysis. In this study, photocatalytic degradation of sulfolane using titanium dioxide (TiO2) and reduced graphene oxide TiO2 composite (RGO-TiO2) in a light-emitting diode (LED) photoreactor was investigated. The impact of different waters (ultrapure water, tap water, and groundwater) and type of irradiation (UVA-LED and mercury lamp) on photocatalytic degradation of sulfolane were also studied. In addition, a reusability test was conducted for the photocatalyst to examine the degradation of sulfolane in three consecutive cycles with new batches of sulfolane-contaminated water. The results show that LED-based photocatalysis was effective in degrading sulfolane in waters even after three photocatalytic cycles. UVA-LEDs displayed more efficient use of photon energy when compared with the mercury lamps as they have a narrow emission spectrum coinciding with the absorption of TiO2. The combination of UVA-LED and TiO2 yielded better performance than UVA-LED and RGO-TiO2 for the degradation of sulfolane. Much lower sulfolane degradation rates were observed in tap water and groundwater than ultrapure water.


2021 ◽  
Vol 9 (9) ◽  
pp. 3052-3057
Author(s):  
Jerzy J. Langer ◽  
Ewelina Frąckowiak

H+LEDs are light emitting devices based on a protonic p–n junction; now with no organic polymers. The unique are non-linear optical effects: collimated light beams and stimulated Raman scattering (SRS), observed while generating intense light pulses.


2013 ◽  
Vol 17 (4) ◽  
pp. 363-370 ◽  
Author(s):  
Santosh M. Harish ◽  
Shuba V. Raghavan ◽  
Milind Kandlikar ◽  
Gireesh Shrimali

RSC Advances ◽  
2015 ◽  
Vol 5 (35) ◽  
pp. 27491-27495 ◽  
Author(s):  
Wei Tang ◽  
Ye Sun ◽  
Miao Yu ◽  
Xiao Liu ◽  
Yongqi Yin ◽  
...  

White-light emission from SrTiO3:Pr3+ nanoparticles has been achieved by tuning combination of the 3P0 and 1D2-related blue to red emissions.


2013 ◽  
Vol 211 (3) ◽  
pp. 651-655 ◽  
Author(s):  
Jorge Oliva ◽  
Elder De la Rosa ◽  
Luis Diaz-Torres ◽  
Anvar Zakhidov

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