PMT System Research Articles

A Novel High-Throughput and Sensitive Electrochemiluminescence Immunoassay System.

(1) Background: In vitro diagnostic (IVD) tests are the main means of obtaining diagnostic information for clinical purposes. The electrochemiluminescence immunoassay (ECLIA) has become an important in vitro diagnostic technique. It has unique advantages and broad market prospects due to its sensitivity, detection limit, detection range and reagent stability. At present, there is a need to develop and optimize electrochemiluminescence immunoassay subsystems to achieve high-throughput outputs and accurate detection of instruments to promote their clinical application. (2) Methods: On the basis of the demand for clinical testing instruments with high detection accuracy and speed, this study constructed an electrochemiluminescence immunoassay system by designing magnetic separation modules, introducing PMT and optimizing the system timing regulation capability. (3) Results: The magnetic separation modules can increase the detection accuracy, the PMT system increases the detection sensitivity and optimized system timing can achieve maximum test output. Furthermore, this system performs well in terms of its linearity, detection limit, signal-to-noise ratio, precision and accuracy. (4) Conclusions: The electrochemiluminescence immunoassay system is capable of high throughput with good sensitivity and accuracy, meeting the basic requirements of clinical applications for detection capacity and output throughput.

An integrated, multi-functional intrinsic responsive foldable protective layer for space station solar panels

The functionalized foldable protective layer proficiently alleviates the potential detriment endured by space station solar panels due to prolonged and uninterrupted exposure to the environment. Soft actuators demonstrate significant value in foldable protective layers due to their intrinsic response characteristics and programmability. However, current soft actuators still struggle to meet the requirements of work stability and scene applicability in the space environment. A PMT (Polydimethylsiloxane (PDMS)/Multi-walled carbon nanotubes (MWCNTs)-Thermoplastic polyimides (TPI)) soft actuator was proposed to address this issue in this paper. The PMT soft actuators exhibit strong interlayer interfacial adhesion, stable physical and chemical performance, and excellent mechanical performance. Notably, the PMT soft actuators can sense thermal, electric fields, infrared light, and mechanical force simultaneously with only one active layer. Furthermore, analytical models were calibrated to provide predictions, and the thermal and photoelectric actuation processes of PMT soft actuators with different structures and application scenes were predicted accurately. The experimental results validated the application value of PMT actuators as foldable protective layers for space station solar panels. The preparation, testing, application, and model construction of the PMT system provide new research ideas and development opportunities for the practical application of functional polymers in intelligent sensing and actuation systems.

The PMT system of the TRIDENT pathfinder experiment

Next generation neutrino telescopes are highly anticipated to boost the development of neutrino astronomy. A multi-cubic-kilometer neutrino telescope, TRopIcal DEep-sea Neutrino Telescope (TRIDENT), was proposed to be built in the South China Sea. The detector aims to achieve ∼ 0.1 degree angular resolution for track-like events at energy above 100 TeV by using hybrid digital optical modules, opening new opportunities for neutrino astronomy. In order to measure the water optical properties and marine environment of the proposed TRIDENT site, a pathfinder experiment was conducted, in which a 100-meter-long string consisting of three optical modules was deployed at a depth of 3420 m to perform in-situ measurements. The central module emits light by housing LEDs, whereas the other two modules detect light with two independent and complementary systems: the PMT and the camera systems. By counting the number of detected photons and analyzing the photon arrival time distribution, the PMT system can measure the absorption and scattering lengths of sea water, which serve as the basic inputs for designing the neutrino telescope. In this paper, we present the design concept, calibration and performance of the PMT system in the pathfinder experiment.

Rapid screening technique for gross α and gross β estimations in aqueous samples during radiation emergency

Abstract A portable liquid scintillation counting system has been used as a rapid screening tool for radiological characterization and in situ measurements of aqueous samples. The methodology was standardized based on the Pulse Length Index for gross α and gross β activity determinations in aqueous solutions by means of a portable Liquid Scintillation Counter (LSC). This single compact PMT system yielded precise results for aqueous test samples, which were validated against a conventional HIDEX 300SL LSC system. The sensitivity of the portable LSC for gross measurements was investigated thoroughly for various combinations of scintillation cocktails and sample proportions, and found to be well below the Operational Intervention Levels (OILs) recommended by Atomic Energy Regulatory Board (AERB) during radiation emergency scenarios. Gross α- and β-activity measurements by means of the portable LSC system have shown this procedure to be effective for preliminary screening and evaluating the total radioactivity in aqueous samples during such radiation emergencies.

Virulent Staphylococcus aureus colonizes pediatric nares by resisting killing of human antimicrobial peptides

BackgroundThe nasal carriage of Staphylococcus aureus introduces risks for subsequent infections, the rate of which is particularly high in children. The colonization mechanisms of S. aureus are not fully understood. MethodsThe epidemiological characteristics of nasal colonizing strains from pediatric patients undergoing liver transplantation and healthy pre-school children were analyzed first. Phenotypes, including biofilm formation and hemolytic activity, were tested for all the isolates. Bacterial pathogenicity indicated by a mouse skin abscess model and resistance to antimicrobial peptides (AMPs) was compared between the predominant genotypes from each group. ResultsThe ST188 clone dominated in healthy children, whereas ST59 was prevalent for the pediatric patients. Although ST22 was the second most abundant genotype in the patient group, it was rarely found in healthy children. Interestingly, the colonizing ST59 and ST22 genotypes were more virulent, as indicated by the increased ability for hemolysis in vitro and severe subcutaneous abscesses in the mouse model, compared with ST188. We observed that the virulent ST59 and ST22 displayed higher resistance to antibiotics compared with ST188. Most of the ST59 and ST22 were methicillin-resistant S. aureus (MRSA), and all of the ST188 strains were methicillin-susceptible (MSSA). Moreover, we observed that the virulent ST59 and ST22 can resist killing by human antimicrobial peptides (AMPs). Mechanically, upon stimulation by AMPs, the virulent S. aureus can induce high expression of a phenol-soluble modulin transporter (Pmt) system. ConclusionPediatric patients can be colonized by virulent S. aureus clones, which are able to resist AMPs’ killing through the Pmt system. The residence of virulent strains necessitates the continuous monitoring of potential infections, as well as annealing, to take protective decolonization measures.

The analysis of <i>Period1</i> gene expression in freely moving mouse using micro PMT system.

The analysis of <i>Period1</i> gene expression in freely moving mouse using micro PMT system.

Study and removal of the flash from the HV divider of the 20-inch PMT for JUNO

Many neutrino experiments with PMT system have been suffered from the unexpected flash, which is a corona discharge generated by the HV divider of PMT. There are approximately 20,000 20-inch PMTs and HV dividers in JUNO, hence it is critical for minimizing the flash for this large PMT system in order not to contaminate the physics data coming from neutrinos. In this paper, we studied the characteristics of the flash and measured its emission rate. Eventually the sources of the flash were identified, and the solutions were found in reducing and completely removing the flash.

The Status of JUNO

The Jiangmen Underground Neutrino Observatory (JUNO) is a multi-purpose underground experiment and the largest liquid scintillator (LS) detector going for neutrino mass hierarchy, precise measurement of neutrino oscillation parameters and other rare processes which include but not limited to solar neutrino, geo-neutrino, supernova neutrinos and the diffuse supernova neutrinos background. The 20” PMT system with ∼18000 high quantum efficiency phototubes, including Hamamatsu 20” and newly developed NNVT MCP 20” tubes, is the key component of JUNO experiment for better energy resolution, good detector response etc. This article reports the status of the JUNO experiment.

The MicroBooNE continuous readout stream for detection of supernova neutrinos

Since the original detection of core-collapse supernova neutrinos in 1987, all large neutrino experiments seek to detect the neutrinos from the next nearby supernova. Among them, liquid argon time projection chambers (LArTPCs) offer a unique sensitivity to the electron neutrino flux of a supernova. However, the low energy of these events (scale of MeVs), and the fact that all large (multi-tonne) LArTPCs operating at the moment are located near the Earth’s surface, and are therefore subject to an intense cosmic ray flux, makes triggering on the supernova neutrinos very challenging. Instead, MicroBooNE has pioneered a novel approach for detecting supernova neutrinos based on a continuous readout stream and a delayed trigger generated by other neutrino detectors (the Supernova Early Warning System, or SNEWS). MicroBooNE’s data is stored temporarily for a few days, awaiting a SNEWS alert to prompt the permanent recording of the data. In order to cope with the large data rates produced by the continuous readout of the TPC and the PMT systems of MicroBooNE, FPGA-based zero-suppression algorithms have been developed.

Equatorial secondary cosmic ray observatory to study space weather and terrestrial events

Recently, equatorial secondary cosmic ray observatory has been established at Equatorial Geophysical Research Laboratory (EGRL), Tirunelveli, (Geographic Coordinates: 8.71°N, 77.76°E), to study secondary cosmic rays (SCR) produced due to the interaction of primary cosmic rays with the Earth’s atmosphere. EGRL is a regional center of Indian Institute of Geomagnetism (IIG), located near the equator in the Southern part of India. Two NaI(Tl) scintillation detectors are installed inside the temperature controlled environment. One detector is cylindrical in shape of size 7.62 cm × 7.62 cm and another one is rectangular cuboid of 10.16 cm × 10.16 cm × 40.64 cm size. Besides NaI(Tl) detectors, various other research facilities such as the Geomagnetic observatory, Medium Frequency Radar System, Digital Ionosonde, All-sky airglow imager, Atmospheric electricity laboratory to measure the near-Earth atmospheric electric fields are also available at EGRL. With the accessibility of multi- instrument facilities, the objective is set to understand the relationship between SCR and various atmospheric and ionospheric processes, during space weather and terrestrial events.For gamma-ray spectroscopy, it is important to test the performance of the NaI(Tl) scintillation detectors and to calibrate the gamma-ray spectrum in terms of energy. The present article describes the details of the experimental setup installed near the equator to study cosmic rays, along with the performance testing and calibration of the detectors under various conditions. A systematic shift in the gain is observed with varying temperature of the detector system. It is found that the detector’s response to the variations in the temperature is not just linear or non-linear type, but it depends on the history of the variation, indicating temperature hysteresis effects on NaI detector and PMT system. This signifies the importance of isothermal environment while studying SCR flux using NaI(Tl) detectors, especially for the experiments conducted during daytime such as solar eclipses etc.

Double calorimetry system in JUNO

Energy resolution is the key of the reactor antineutrino spectrum measurement, for the determination of the neutrino mass hierarchy. The control of the systematics of the energy response is a challenge to the large liquid scintillator experiment such as JUNO. A small-PMT system was proposed to work with the large-PMT system as a double calorimetry. The individual 3-inch PMT receives mostly single photoelectrons, which provides a unique way to calibrate the energy response of the 20-inch PMT system by a photon-counting technology. JUNO has signed a contract with the HZC Company in May 2017 and is going to install 25,000 3-inch PMTs in the central detector. The performances of HZC’s PMT samples can meet the requirements of JUNO. The mass production and testing of PMTs are in preparation, and the R&D of the readout electronics and the underwater box is ongoing. The double calorimetry system was approved by JUNO. The system is under construction and is expected to be in operation in 2020.

JUNO PMT system and prototyping

The Jiangmen Underground Neutrino Observatory (JUNO) is a multi-purpose underground experiment and the largest liquid scintillator (LS) detector going for neutrino mass hierarchy, precise neutrino oscillation parameter measurement and studies of other rare processes, including but not limited to, solar neutrino, geo-neutrino, supernova neutrinos and the diffuse supernova neutrinos background. The 20” PMT system with ∼17000 high quantum efficiency tubes, including Hamamatsu 20” and newly developed MCP 20” tubes, is one of the keys of JUNO experiment for better energy resolution, good detector response etc. We are doing prototypes for PMTs, detectors to study/understand more detailed characteristics of the future detector. Here plans to give you a full view about the JUNO PMT system and its prototyping, including the PMT system layout, PMT testing system design, PMT water proof potting with electronics, installation ideas and the basics PMT performance.

Characterization of photo-multiplier tubes for the Cryogenic Avalanche Detector

New Cryogenic Avalanche Detector (CRAD) with ultimate sensitivity, that will be able to detect one primary electron released in the cryogenic liquid, is under development in the Laboratory of Cosmology and Particle Physics of the Novosibirsk State University jointly with the Budker Institute of Nuclear Physics. The CRAD will use two sets of cryogenic PMTs in order to get trigger signal either from primary scintillations in liquid Ar or from secondary scintillations in high field gap above the liquid. Two types of cryogenic PMTs produced by Hamamatsu Photonics were tested and the results are presented in this paper. Low background 3 inch PMT R11065-10 demonstrated excellent performance according to its specifications provided by the producer. The gain measured with single electron response (SER) in liquid Ar reached 107, dark count rate rate did not exceed 300 Hz and pulse height resolution of single electron signals was close to 50%(FWHM). However, two R11065-10 PMTs out of 7 tested stopped functioning after several tens minutes of operation immersed completely into liquid Ar. The remaining 5 devices and one R11065-MOD were operated successfully for several hours each with all the parameters according to the producer specifications. Compact 2 inch PMT R6041-506-MOD with metal-channel dynode structure is a candidate for side wall PMT system that will look at electroluminescence in high field region above liquid. Four of these PMTs were tested in liquid Ar and demonstrated gain up to 2× 107, dark count rate rate below 100 Hz and pulse height resolution of single electron signals of about 110% (FWHM).

Abstract No. 522 - Evaluating the expected budget impact and cost-effectiveness of interventional therapies used in the treatment of chronic venous disease

Purpose Varicose veins (VV) and resulting sequelae contribute to morbidity assoc w/chronic vein disorders (CVD), impacting QOL and resulting in ~ $1B/yr. Total cost minimization and budget impact evaluation assessed 8-wk diff between Varithena ® (polidocanol endovenous microfoam [PEM]) vs alternate tx for VV in US from a 3rd-party payer perspective. Materials and Methods Tx options incl PEM, EVLA, RFA, surgery, and multi-modality tx, defined >1 tx on same day. Total cost components incl (wholesale) drug acquisition costs , pmt for professional (CMS physician fee schedule) and institutional (Hospital Outpatient Prospective Pmt System) services related to initial intervention, weighted for each modality, plus expected costs of addl interventions, weighted by corresponding rate of addl interventions, within 8-wk time frame. Evidence on rate of addl interventions for PEM came from 2 pooled, phase 3 studies, and for other modalities from US retrospective claims analysis of pts w/VV. Budget impact was modeled for hypothetical 1M member plan w/evidence-based assumptions: 76% adults, 6% chronic venous insufficiency prevalence, and 31% rate of interventional tx among pts w/dx VV, and derived in terms of total and per-member-per-month (PMPM) expenditure change given 5% initial PEM market share. Results PEM was expected to cost $2,165 (incl $615 (28%) for addl tx) compared to $2,374 (14% for addl tx) for surgery, $2,106 (32% for addl tx) for RFA, $1,827 (38% for addl tx) for EVLA, and $2,844 (26% for addl tx) for multi-modality tx. Budget impact for 1M member hypothetical health plan was $87k or $0.01 PMPM. Conclusion PEM is expected to have slightly lower addl tx rates than and cost ~ same as RFA and EVLA (performed alone) but be less costly than surgery and multi-modality tx (≥2 interventions on same day) for VV tx. Adding PEM to the formulary for a health plan is ~ budget neutral. Exp 8-wk Costs, Tx Options Comparator Initial tx costs Addtl tx rate Expected addtl tx cost Total expected costs PEM $1550 39.7% $615 $2165 EVLA $1130 52.4% $697 $1827 RFA $1430 40.0% $676 $2106 Surgery $2049 17.9% $325 $2374 Multi-modality tx $2107 34.9% $737 $2844

Physicochemical Properties of Amphiphilic Drug and Anionic Surfactant Mixtures: Experimental and Theoretical Approach

Herein, we have reported the mixed micelle formation of amphiphilic phenothiazine drug promethazine hydrochloride (PMT) and anionic surfactant sodium bis(2-ethylhexyl)sulfosuccinate (AOT) mixtures at different compositions and temperatures (288.15, 293.15, 298.15, 303.15, and 308.15 K). A conductometric method is used to evaluate the critical micelle concentration (CMC) of binary mixtures. An attractive interaction between PMT and AOT mixed systems was indicated by the experimental and ideal critical micelle concentration (CMC and CMCid) values. The micellar mole fraction of anionic surfactant (, , , and ) was evaluated by different proposed models, and they prove the greater contribution of AOT in mixed micelle and increase with the increase in AOT concentration. Activity coefficients (f 1 and f 2) calculated by all recommended models were found to be always less than unity, signifying nonideality in the mixed systems. Different thermodynamic parameters have also been evaluated using the respective CMC values as a function of temperature. values were always found to be negative for all the systems; however, for pure drug as well as PMT–AOT mixed systems is negative at lower temperatures and positive at higher temperatures. The values are positive at all temperatures but their magnitude is higher at T = 303.15 K and above.

Control and energy performances of water hydraulic FST and PMT systems

Control and energy performances of water hydraulic FST and PMT systems

Studies on the interaction of palmatine hydrochloride with bovine hemoglobin

The interaction between bovine hemoglobin (BHb) and palmatine hydrochloride (PMT) was investigated at different temperatures using multispectroscopy, as well as the effect of common metal ions (Ca(2+) , Mg(2+) , Zn(2+) , Cu(2+) , Fe(2+) , Fe(3+) , Co(2+) , Ni(2+) ) on the BHb-PMT system. Results showed that the quenching mechanism of PMT on BHb was a static process. The electrostatic force played an important role in the conjugation reaction between BHb and PMT. The order of magnitude of the binding constants (Ka ) was 10(4) , and the number of binding sites (n) in the binary system was ~ 1. The binding distance (r) was ~ 2.44 nm and the primary binding for PMT was located at β-37 tryptophan in the hydrophobic cavity of BHb. In addition, the Hill's coefficients were ~ 1. Synchronous and circular dichroism spectra revealed that the microenvironment and the conformation of BHb were changed during the binding reaction.

Licensing poultry CO2gas-stunning systems with regard to animal welfare: investigations under practical conditions

AbstractCarbon dioxide stunning of broilers is not permitted in Germany. However, the competent authority can license a system for testing, during which scientific evaluation with regard to animal welfare is required. Between 2004 and 2011 several aspects of three systems have been evaluated in Germany and Italy under practical conditions including: (i) supply to the stunning system; (ii) induction conditions; (iii) stunning effectiveness; and (iv) process control. The systems were: (i) LINCO progressive gas-stunning system in which broilers in their transport crates are lowered stepwise into a pit filled with CO2and exposed to slowly increasing concentrations of CO2in air up to between 50 and 65% with total dwell times between 275 and 440 s depending on birds’ weight; (ii) Stork PMT two-phase gas-stunning system (40% CO2/30% O2/30%N2for 1 min/80% CO2for 2 min) in which broilers are tipped onto a belt, on which they pass through the gas atmospheres; and (iii) Anglia Autoflow two-phase CO2-stunning system, in which the birds are exposed to the atmosphere in their crates. Results on the third system are pending as the investigation is still ongoing. In systems (i) and (ii) analysis of behaviour showed that birds were only exposed to high CO2concentration (> 40%) after becoming unconscious. Stunning effectiveness was very high but, nevertheless, occasionally birds (0.027% LINCO system and 0.003% Stork PMT system) were able to regain consciousness. Examples of evaluation of behaviour during induction are presented in this paper and animal welfare aspects are compared. Controlled-atmosphere stunning systems for broilers using less than 40% CO2until animals are unconscious, show obvious advantages compared to electrical water-bath stunning, for example, the avoidance of shackling and achieving high stunning effectiveness.

Time-Domain Fluorescence Lifetime Imaging Techniques Suitable for Solid-State Imaging Sensor Arrays

We have successfully demonstrated video-rate CMOS single-photon avalanche diode (SPAD)-based cameras for fluorescence lifetime imaging microscopy (FLIM) by applying innovative FLIM algorithms. We also review and compare several time-domain techniques and solid-state FLIM systems, and adapt the proposed algorithms for massive CMOS SPAD-based arrays and hardware implementations. The theoretical error equations are derived and their performances are demonstrated on the data obtained from 0.13 μm CMOS SPAD arrays and the multiple-decay data obtained from scanning PMT systems. In vivo two photon fluorescence lifetime imaging data of FITC-albumin labeled vasculature of a P22 rat carcinosarcoma (BD9 rat window chamber) are used to test how different algorithms perform on bi-decay data. The proposed techniques are capable of producing lifetime images with enough contrast.

News from the Sudbury Neutrino Observatory

The Sudbury Neutrino Observatory (SNO) [1] is a 1000 tonne heavy water Cerenkov detector, that has finished its data taking period on November 29th 2006. The heavy water was contained in a 12 m diameter acrylic sphere, surrounded by 9500 PMTs. It is located in INCOs Creighton mine in Sudbury, Ontario, Canada - 2039 m (6000 mwe) underground. The so-called third phase of the experiment had in addition to the heavy water an array of 36 3He and 4 4He proportional counters installed. In this configuration it can detect neutrons produced by the neutral current interaction of solar neutrinos by neutron capture in these counters (NCDs = neutral current detection array). This is a way to determine the neutral current flux independent of the PMT system with very different systematic uncertainties and is therefore determining the CC and NC reactions in separate streams.