1,885 research outputs found
Trigger efficiencies at BES III
Trigger efficiencies at BES III were determined for both the J/psi and psi'
data taking of 2009. Both dedicated runs and physics datasets are used;
efficiencies are presented for Bhabha-scattering events, generic hadronic decay
events involving charged tracks, dimuon events and psi' -> pi+pi-J/psi, J/psi
-> l+l- events (l an electron or muon). The efficiencies are found to lie well
above 99% for all relevant physics cases, thus fulfilling the BES III design
specifications.Comment: 6 pages, 4 figure
Measurement to radius of Newton’s ring fringes using polar coordinate transform
Background: Newton’s ring method is often used to measure many physical parameters. And some measured physical quantity can be extracted by calculating the radius parameter of circular fringes from Newton's ring configuration.
Methods: The paper presents a new measuring method for radius of circular fringes, which includes three main steps, i.e., determination of center coordinates of circular fringes, polar coordinates transformation of circular fringes, and gray projection of the transformed result which along the horizontal direction. Then the radius values of each order ring are calculated.
Results: The simulated results indicate that the measuring accuracy of the radius under the effect of random noise can keep the degree of less than 0.5 pixels.
Conclusions: The proposed method can obtain the radius data of each order closed circular fringes. Also, it has several other advantages, including ability of good anti-noise, sub-pixel accuracy and high reliability, and easy to in-situ use
Changes of plasma fibroblast growth factor-21 (FGF-21) in oral glucose tolerance test and effects of metformin on FGF-21 levels in type 2 diabetes mellitus
Wstęp: Badanie przeprowadzono w celu ustalenia, czy czynnik wzrostu fibroblastów-21 (FGF-21) uczestniczy w regulacji stężenia glukozy
i czy zastosowanie metforminy u chorych na cukrzycę wpływa na stężenie FGF-21.
Materiał i metody: Do badania włączono 43 osoby, w tym 27 chorych z nowo rozpoznaną cukrzycą typu 2 (nT2DM). U wszystkich przeprowadzono
test doustnego obciążenia 75 g glukozy (OGTT). Próbki krwi pobrano w 0., 60.,120. i 180. minucie testu. Osobom z nT2DM
zaproponowano udział w dalszych badaniach; zastosowano u nich metforminę w dawce 1,0 g/dobę przez tydzień.
Wyniki: Zmiany stężenia FGF-21 w osoczu podczas OGTT zaobserwowano tylko w grupie chorych na nT2DM; w grupie kontrolnej stężenie
FGF-21 pozostało niezmienione. Nie stwierdzono, by stężenia FGF-21 w poszczególnych punktach czasowych różniły się w zależności od płci
badanych (p < 0,05). Zastosowanie metforminy u osób z nT2DM spowodowało istotne zmniejszenie stężeń glukozy i FGF-21 we wszystkich
punktach czasowych OGTT oraz zmniejszenie stężenia insuliny w 60. i 180. minucie, co wskazuje na obniżenie wskaźnika HOMA-IR.
Wnioski: FGF-21 nie uczestniczy w krótkoterminowej regulacji glikemii u ludzi, a zmiany jego stężenia podczas OGTT są opóźnione
w T2DM. Być może FGF-21 bierze udział w metabolizowaniu metforminy, zwiększając wrażliwość na glukozę i insulinę.
(Endokrynol Pol 2013; 64 (3): 220–224)Introduction: The objectives of our study were to investigate whether fibroblast growth factor-21 (FGF-21) is involved in short-term
regulation of glucose and the change of FGF-21 after metformin use in diabetic subjects.
Material and methods: 43 subjects were recruited in the study, including 27 new-onset type 2 diabetes patients (nT2DM). A 75 g oral
glucose tolerance test (OGTT) was administered to them. Blood samples were taken at 0, 60 ,120 and 180 minute of OGTT. nT2DM subjects
were invited for further investigation, metformin was administered in a dose of 1.0 g every day for 1 week.
Results: Plasma FGF-21 changed significantly in the nT2DM group during the OGTT administration but not in the control group. No
gender differences were observed at different time points in FGF-21 levels (p < 0.05). Administration of metformin for nT2DM resulted
in a significant decrease in both glucose and FGF-21 at all OGTT times and in insulin at 60 min and 180 min, indicative of a decrease in
HOMA-IR.
Conclusion: FGF-21 does not seem to be involved in short-term regulation of glycaemia in human subjects, and the change in OGTT
delayed in T2DM. FGF-21 may participate in the processing of metformin, improving glucose and insulin sensitivity.
(Pol J Endocrinol 2013; 64 (3): 220–224
Experimental study of THGEM detector with mini-rim
The gas gain and energy resolution of single and double THGEM detectors
(5{\times}5cm2 effective area) with mini-rims (rim is less than 10{\mu}m) were
studied. The maximum gain can reach 5{\times}103 and 2{\times}105 for single
and double THGEM respectively, while the energy resolution of 5.9 keV X-ray
varied from 18% to 28% for both single and double THGEM detectors of different
hole sizes and thicknesses.All the experiments were investigated in mixture of
noble gases(argon,neon) and small content of other gases(iso-butane,methane) at
atmospheric pressure.Comment: 4pages,6figures, it has been submitted to Chinese Physics
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