New Method For Quantitative Measurement Research Articles

Quantitative Measurement of Plasma Free Metanephrines by a Simple and Cost-Effective Microextraction Packed Sorbent with Porous Graphitic Carbon and Liquid Chromatography-Tandem Mass Spectrometry.

Plasma free metanephrines are widely used for the diagnosis of pheochromocytoma and paraganglioma (PPGL), yet quantifying metanephrines using a simple and cost-effective approach may be challenging due to preanalytical and analytical constraints. In this study, we established and validated a new method for quantitative measurement of plasma free metanephrines based on microextraction by packed sorbent (MEPS) with porous graphitic carbon (PGC) and liquid chromatography-tandem mass spectrometry (HILIC-MS/MS). The elution step was fully compatible with HILIC mode without evaporation and reconstitution. The analytes were well resolved, and potential interferences (54 substances) were investigated. This method was linear from 24.7–2717 pg/mL for metanephrine (MN) and 24.5–4010 pg/mL for normetanephrine (NMN) with a coefficient of determination (R2) higher than 0.994. The limit of MN and NMN detection were 12.4 pg/mL and 12.3 pg/mL, respectively. The intra- and interassay impressions were ≤12.8% for spiked quality controls and ≤13.6% for commercial quality controls; the method recoveries ranged within 88.0–109.0%, respectively. The area under the receiver operating characteristic (ROC) curve was 0.848 ± 0.047 for MN and 0.979 ± 0.021 for NMN. Validation that was performed by comparing clinical specimens with various biochemical results showed that plasma free metanephrines in a seated position had comparable sensitivity and lower specificity to urinary free metanephrines, which could be compensated by combining other biochemical tests. The newly developed MEPS method resulted as a time-saving, reliable, and cost-effective microextraction technique that can be applied for a successful screening of PPGL.

Evolution mechanism of ultraviolet and electrical phenomena induced by protrusion discharge in GIS

Abstract To improve the sensitive and reliability of condition monitoring in gas insulated switchgear (GIS), discharge perception system applied to GIS insulators protrusion discharge based on single ultraviolet photon is built. Step method is used to inspire the discharges of different severity, based on which, the regression relationship of ultraviolet (UV) signal and electrical signal are studied, and the perception mechanism of UV signal in different severity of discharges is analyzed. The study indicates that, the development of protrusion discharge in GIS can be divided into four stages, and there is no positive correlation between the number of ultraviolet photons caused by discharge radiation and insulation deterioration level, but related to the diffusion, migration and recombination of charged particles, then UV optical method for quantitative monitoring of discharge in each stage is provided, which provide a new method for quantitative measurement of GIS insulator discharge.

New method for quantifying water stability of soil aggregates from air bubbling after immersion

Existing methods for estimation of water stability of aggregates suffer from intrinsic uncertainties and are not more than semi-quantitative. New method for quantitative measurement of aggregate destruction rate in water was developed basing on monitoring of air bubbling after aggregate immersion by recording a decrease in buoyancy of the aggregate during air evolution. The method allows to estimate destruction mechanism and to calculate kinetic parameters of the destruction process. The rate of the destruction of spherical aggregates made from 2-mm sieved soil material was successfully fitted to a shrinking sphere model. The time of the complete destruction divided by the initial surface of the aggregate was constant for a given soil regardless the aggregate size and it was used as a parameter distinguishing different soils. The proposed method allows for studying rapidly destroyed aggregates for which all available methods generally fail.

Shear wave elastography parameters of normal soft tissues of the neck.

Shear wave elastography is a relatively new method of quantitative measurement of tissue elasticity. Assuming that malignant lesions are stiffer than benign ones, elastography may provide supplementary information for their discrimination. However, potential confounding factors impacting tissue stiffness should be investigated first. The objective of this study was to measure the stiffness of selected tissues of the head and neck in a normal population and to evaluate its relationship to age, sex, and body mass index. Stiffness of the thyroid, submandibular and parotid glands, masseter and sternocleidomastoid muscles, and cervical lymph nodes was measured bilaterally in 128 healthy volunteers (83 female and 45 male). At least 20 subjects in each decade of life (20-29, 30-39‥, 70+) were enrolled. Shear wave elastography was performed by a single radiologist in all the subjects. The stiffnesses obtained were correlated with age, sex, and body mass index. The mean stiffness was 9.5 ± 3.6 kPa for the thyroid, 9.5 ± 4.6 kPa for the lymph node, 11.0 ± 3.4 kPa for the submandibular gland, 9.0 ± 3.5 kPa for the parotid gland, 9.9 ± 4.1 kPa for the sternocleidomastoid, and 10.0 ± 4.3 kPa for the masseter muscle. A slight general decrease in stiffness with increasing age was found. BMI and weight had a small impact on the minimum and maximum stiffness values. The sex of the subject did not affect elasticity. The mean stiffness of healthy head and neck organs has a relatively narrow distribution around 11 kPa. The changes of stiffness with age, BMI, and weight that were identified are too small to have clinical impact.

MP84-15 A NEW METHOD OF QUANTITATIVELY MEASURING PENILE ERECTION HARDNESS IN ERECTILE DYSFUNCTION PATIENTS: REAL-TIME ULTRASONIC SHEAR WAVE ELASTOGRAPHY

You have accessJournal of UrologySexual Function/Dysfunction: Evaluation II1 Apr 2017MP84-15 A NEW METHOD OF QUANTITATIVELY MEASURING PENILE ERECTION HARDNESS IN ERECTILE DYSFUNCTION PATIENTS: REAL-TIME ULTRASONIC SHEAR WAVE ELASTOGRAPHY Lin Yang, Hao Cheng, and Litao Ruan Lin YangLin Yang More articles by this author , Hao ChengHao Cheng More articles by this author , and Litao RuanLitao Ruan More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2017.02.2656AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Penile erection hardness (EH), according to the Erectile Hardness Grading Scale (EHS), is an important indicator for evaluating penile erectile function. In this study, we provided a new method of real-time quantitative measurement of penile EH for erectile dysfunction (ED) patients using ultrasonic shear wave elastography (SWE). METHODS Sixty ED patients diagnosed using the IIEF-5 questionnaire and the presence of nocturnal penile tumescence underwent real-time SWE to measure Young's modulus of the penile corpus cavernosum and albuginea while resting and at various grades of EH. Prostaglandin injection into the corpus cavernosum was used to induce penile erection. RESULTS Young's modulus for the corpus cavernosum (resting) and EH grades 1, 2, 3, and 4 were, (12.16±1.97)kPa,(10.97±1.98)kPa,(9.06±1.71)kPa,(9.38±1.68)kPa,(9.36±1.34)kPa respectively; Corresponding Young's modulus values for the albuginea (resting) and EH grades 1, 2, 3, and 4 were(21.97±4.68)kPa,(32.71±3.71)kPa,(54.12±10.09)kPa ,(127.81±18.10)kPa ,(223.99±26.73)kPa respectively. These Young's modulus values were grouped respectively to draw the receiver operating characteristics curve. The area under the albuginea curve was significantly better than that of the cavernosum (?2 = 61.10). Cutoff point of albuginea at grade 3 hardness was 81.60kPa. CONCLUSIONS Quantitatively measuring Young's modulus of penile albuginea using SWE is a novel, noninvasive, objective technique for quantitatively assessing the EH of ED patients. We proved that albuginea hardness, not cavernous tissue hardness, was a good clinical imaging index for penile EH evaluating. © 2017FiguresReferencesRelatedDetails Volume 197Issue 4SApril 2017Page: e1145 Advertisement Copyright & Permissions© 2017MetricsAuthor Information Lin Yang More articles by this author Hao Cheng More articles by this author Litao Ruan More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Mapping 15O Production Rate for Proton Therapy Verification

This work was a proof-of-principle study for the evaluation of oxygen-15 ((15)O) production as an imaging target through the use of positron emission tomography (PET), to improve verification of proton treatment plans and to study the effects of perfusion. Dynamic PET measurements of irradiation-produced isotopes were made for a phantom and rabbit thigh muscles. The rabbit muscle was irradiated and imaged under both live and dead conditions. A differential equation was fitted to phantom and in vivo data, yielding estimates of (15)O production and clearance rates, which were compared to live versus dead rates for the rabbit and to Monte Carlo predictions. PET clearance rates agreed with decay constants of the dominant radionuclide species in 3 different phantom materials. In 2 oxygen-rich materials, the ratio of (15)O production rates agreed with the expected ratio. In the dead rabbit thighs, the dynamic PET concentration histories were accurately described using (15)O decay constant, whereas the live thigh activity decayed faster. Most importantly, the (15)O production rates agreed within 2% (P>.5) between conditions. We developed a new method for quantitative measurement of (15)O production and clearance rates in the period immediately following proton therapy. Measurements in the phantom and rabbits were well described in terms of (15)O production and clearance rates, plus a correction for other isotopes. These proof-of-principle results support the feasibility of detailed verification of proton therapy treatment delivery. In addition, (15)O clearance rates may be useful in monitoring permeability changes due to therapy.

Molecular Rotors Image Intracellular Viscosity

This review describes a new method for quantitative measurement and spatial imaging of microviscosity within individual domains of live cells. The method is based on fluorescence detection from small synthetic molecules termed 'molecular rotors', which are characterised by a strong response of fluorescence lifetimes or spectra to the viscosity of their immediate environment. We have demonstrated that the quantitative determination of viscosity is possible using lifetime-based molecular rotors and ratiometric molecular rotors. The ratiometric imaging of viscosity benefits from a very fast signal acquisition. We have illustrated this advantage by monitoring changes in intracellular viscosity during photodynamic therapy, which is a clinically utilised modality for the treatment of neoplastic disease.

A General Method for Measurement of Enantiomeric Excess by Using Electrooptics in Ferroelectric Liquid Crystals

It's ee rie: A new method for quantitative measurement of ee values is described. The method exploits the unique electrooptic properties of the chiral smectic A liquid-crystal phase and is potentially applicable to the high-throughput (>106 determinations per day) measurement of ee values for any chiral analyte.

Positron emission tomography: quantitative measurement of brain acetylcholinesterase activity using radiolabeled substrates

A new method for quantitative measurement of brain acetylcholinesterase (AChE) activity in living human brain using positron emission tomography (PET) is described. We tested several radiolabeled lipophilic acetylcholine analogs, e.g., N-methylpiperidyl esters, which readily entered the brain via the blood–brain barrier, were hydrolyzed selectively by AChE, and were then trapped in the brain. Among them, and tested and N-[ 11C]methylpiperidin-4-yl acetate ([ 11C]MP4A) was chosen as the tracer for PET. Quantitative measurement of cortical AChE was accomplished by fitting the time course of cerebral radioactivity concentration measured by PET and the metabolite-corrected arterial plasma input function using a nonlinear least-squares fitting method. Normal control studies of subjects with a wide range in age (24–89 years) showed no decrease in AChE activity in the cerebral cortex with age. Studies on patients with Alzheimer's disease demonstrated a widespread reduction of AChE activity in the cerebral cortex (more profound in early-onset than in late-onset Alzheimer's disease). Parkinson's disease and progressive supranuclear palsy, clinically similar disorders, could be differentiated with [ 11C]MP4A/PET studies. Simple methods without using an arterial input function are also proposed. The method provides a quantitative measure of the cholinergic aspect of brain function and proved to be useful in diagnosis of neurodegenerative disorders including Alzheimer's disease.

A new method of quantitative measurement of intermittent claudication using near-infrared laser spectrophotometry

A new method of quantitative measurement of intermittent claudication using near-infrared laser spectrophotometry

Laser Induced Fluorescence in a Pulsed Propagated Flame—A New Technique for Combustion Studies

ABSTRACT We demonstrate that Laser Induced Fluorescence in a pulsed propagated flame can be used as a new method for quantitative measurements in combustion. Time resolved LIF measurements were used to obtain temporal temperature and concentration profiles of OH radicals and S2 molecules in hydrogen/air flames doped with SO2. The advantages of the proposed approach are discussed.

Quantitative Measurement of 2-D Fuel Vapor Concentration in a Transient Spray via a Laser-Induced Fluorescence Technique.

A new method of quantitative measurement of fuel vapor concentration in transient evaporating sprays is described. TMPD, a fluorescence dopant, was doped in n-tridecane fuel, and the blended fuel was injected into high-temperature and high-pressure nitrogen to form an evaporating spray. A sheet of laser light from a pulsed Nd : YAG laser illuminated a cross section of the evaporated spray to induce a fluorescence emission from TMPD vapor in the spray. The laser-induced fluorescence image taken from a direction perpendicular to the illuminated plane was analyzed based on a detailed calibration concentration conducted at high-temperature and high-pressure conditions and an assumption of the thermal equilibrium state for fuel vapor and nitrogen mixture. The quantitative fuel vapor concentration distribution at an instant in an evaporating spray was thus obtained by the analysis, and its accuracy was proved satisfactory through a comparison of the mass of fuel vapor integrated over the entire spray and the mass of injected fuel.

Quantitative analysis of blood group antigen of transitional cell carcinoma of the urinary tract by flow cytometry

We propose a new method of quantitative measurement of cell surface blood group antigen (BGA) in superficial transitional cell carcinoma (TCC) of the urinary tract by using flow cytometry. Flow cytometric analysis was performed on 22 cases of superficial urinary tract TCC registered at the department of Urology, Okayama University Hospital during April, 1992-Feb. 1993. Fresh samples were divided into two specimens. One specimen was fixed in 20% formalin and was subjected to immunohistochemical staining of BGA using avidine-biotine complex (ABC) method. The other specimen was dissociated into single cell with mincing. The single cell was further divided into two specimens. One specimen was incubated on ice with anti-ABH mouse monoclonal antibody (DAKO)as a primary antibody. The other specimen was incubated on ice with mouse IgM as a negative control. These two specimens were reacted with FITC-conjugated rabbit anti-mouse IgM and propidium iodide (PI). Next, these cells were subjected to the flow cytometry using FACStar (Becton & Dickinson). By gating on the bivariate display of FSC vs. FL2 (PI), all nucleated cells were obtained separately and the positive rate was measured. The positive rate of FCM was successfully correlated with the degree of immunohistochemical stain. Compared with immunohistochemical staining thus far, this new technique provides a way to standardize the quantitative measurement of BGA expressions.

A new method for quantitative measurement of correlation defined between different frequency band components

A new method for quantitative measurement of correlation defined between different frequency band components

A new method for quantitative measurement of the cadmium absorbed by chick embryos

We attempted to determine the quantity of cadmium incorporated in hens eggs after immersion in cadmium solutions, and the cadmium concentration measured in embryos. We discussed equipment allowing simultaneous treatment of up to 42 samples, and called it " digestor ". It consisted of two gas-heated sand baths, two stands for cooling down solutions and an evacuation system for toxic vapours. Our method was based on wet mineralisation. It consisted of desintegrating experimental chick embryos in a HNO3/H2O2 mixed solution. After heating and evaporating, the quantity of cadmium in the remnant was determined by atomic absorption spectrophotometry. The reliability of such a technique was tested by studying as controls controls 17 days-old chick embryos injected with a known quantity of Cd(NO3). It showed no loss of cadmium. We also compared our procedure with a dry ashing method. The latter showed unacceptable losses and insufficient precision for the problems we wanted to investigate. Our method gave us much more precise results. The equipment we developed has functioned wholly satisfactorily and allowed us to investigate for instance cadmium distribution and concentration in embryonic organs of 17 days-old chicks. It could also be useful for researches concerning other biological samples analyzed for different heavy metals.

New method for quantitative measurement of N-nitrosodimethylamine formation in the whole mouse.

A simple method for the quantitative estimation of the formation of N-nitrosodimethylamine (NDMA) in mice has been developed. Mice were frozen in liquid nitrogen and homogenized. NDMA was then extracted and analyzed by a gas chromatograph equipped with a thermal energy analyzer. In normal mice NDMA (100 nmole) administered orally was rapidly metabolized and recovery of NDMA was about 10% after 60 min. However, when pyrazole (300 mg/kg) was injected i.p. to mice 60 min before the administration of NDMA, more than 80% of the administered NDMA could be recovered within 60 min. This result suggested that in pyrazole pretreated mice the accurate amount of NDMA formed could be estimated. Therefore the NDMA formation was measured in the pyrazole pretreated mice. When 0.25 mumole of aminopyrine and from 0.25 to 2.0 mumole of sodium nitrite were simultaneously administered orally, the amount of the NDMA formation in 20 min was found to be from 8.2 to 60.3 nmole. These values are equal to about from 30 to 200 micrograms/kg of body weight which are nearly daily doses expected to cause the carcinogenic effect on mice or rats. This method of measuring NDMA in pyrazole pretreated mice appears to be useful for investigating the in vivo formation of NDMA quantitatively.

A New Method for Quantitative Measurement of Gallbladder Filling and Emptying during Fasting and Eating

A New Method for Quantitative Measurement of Gallbladder Filling and Emptying during Fasting and Eating

A new method of quantitative measurement of abdominal and back muscle strength.

A new method of quantitative measurement with a cybex machine is applied to the trunk muscles. The curves of muscle torque and muscle fatigue are easily obtained in clinical medicine. In normal controls, maximal muscle torque is greater in back muscles than in abdominal muscles, and the definite influence of aging is found in both muscles. Furthermore, the trunk muscles are more easily fatigued by a sustained contraction than by repeated contractions, and abdominal muscles are more easily fatigued than back muscles. The role of the trunk muscles in the mechanism of pain production and prevention is still to be determined.

A New Method for Quantitative Measurement of Pain Sensation

A New Method for Quantitative Measurement of Pain Sensation