16,223 research outputs found
Changes in plasma levels of B-type natriuretic peptide with acute exacerbations of chronic obstructive pulmonary disease.
Background:
Elevated plasma B-type natriuretic peptide (BNP) levels and their association with heart failure have been reported in subjects with acute exacerbations of chronic obstructive
pulmonary disease (AECOPD).
Purpose:
To examine and compare plasma BNP levels and diastolic and systolic dysfunction in subjects with AECOPD and s
table chronic obstructive pulmonary disease (COPD).
Methods:
In all,87 unselected consecutive hospitalizations due to AECOPD in 61 subjects and a total of 190 consecutive subjects with stable COPD were recruited. Plasma BNP levels were compared cross-sectionally and longitudinally. Transthoracic echocardiographic examinations
were also performed in the hospitalized subjects.
Results:
In the hospitalized subjects, the median plasma BNP level (interquartile range) was 55.4 (26.9–129.3) pg/mL and was higher than that of patients with stable COPD: 18.3 (10.0–45.3)for Global Initiative for Chronic Obstructive Lung Disease grade I; 25.8 (11.0–53.7) for grade II; 22.1 (9.1–52.6) for grade III; and 17.2 (9.6–22.9) pg/mL for grade IV, all P,0.001.
In 15 subjects studied prospectively, the median plasma BNP level was 19.4 (9.8–32.2) pg/mL before AECOPD, 72.7 (27.7–146.3) pg/mL during AECOPD, and 14.6 (12.9–39.0) pg/mL
after AECOPD (P,0.0033 and P,0.0013, respectively). Median plasma BNP levels during AECOPD were significantly higher in ten unsuccessfully discharged subjects 260.5 (59.4–555.0)
than in 48 successfully discharged subjects 48.5(24.2–104.0) pg/mL (P=0.0066). Only 5.6%
of AECOPD subjects were associated with systolic dysfunction defined as a left ventricular ejection fraction (LVEF),50%; a further 7.4% were considered to have impaired relaxation defined as an E/A wave velocity ratio,0.8 and a deceleration time of E.240 ms. BNP levels were weakly correlated with the E/peak early diastolic velocity of the mitral annulus (Ea) ratio (Spearman’s rank correlation coefficient =0.353,P =0.018), but they were not correlated with the LVEF (Spearman’s rank correlation coefficient =−0.221,P = 0.108).
Conclusion:
A modest elevation of plasma BNP is observed during AECOPD. It appears that AECOPD may have an impact on plasma BNP levels that is not attributable to heart failure
Snowmelt Runoff Model in Japan
The preliminary Japanese snowmelt runoff model was modified so that all the input variables arc of the antecedent days and the inflow of the previous day is taken into account. A few LANDSAT images obtained in the past were effectively used to verify and modify the depletion curve induced from the snow water equivalent distribution at maximum stage and the accumulated degree days at one representative point selected in the basin. Together with the depletion curve, the relationship between the basin ide daily snowmelt amount and the air temperature at the point above are exhibited homograph form for the convenience of the model user. The runoff forecasting procedure is summarized
Contact resistivity and current flow path at metal/graphene contact
The contact properties between metal and graphene were examined. The
electrical measurement on a multiprobe device with different contact areas
revealed that the current flow preferentially entered graphene at the edge of
the contact metal. The analysis using the cross-bridge Kelvin structure (CBK)
suggested that a transition from the edge conduction to area conduction
occurred for a contact length shorter than the transfer length of ~1 micron.
The contact resistivity for Ni was measured as ~5*10-6 Ohmcm2 using the CBK. A
simple calculation suggests that a contact resistivity less than 10-9 Ohmcm2 is
required for miniaturized graphene field effect transistors
The Area Law in Matrix Models for Large N QCD Strings
We study the question whether matrix models obtained in the zero volume limit
of 4d Yang-Mills theories can describe large N QCD strings. The matrix model we
use is a variant of the Eguchi-Kawai model in terms of Hermitian matrices, but
without any twists or quenching. This model was originally proposed as a toy
model of the IIB matrix model. In contrast to common expectations, we do
observe the area law for Wilson loops in a significant range of scale of the
loop area. Numerical simulations show that this range is stable as N increases
up to 768, which strongly suggests that it persists in the large N limit. Hence
the equivalence to QCD strings may hold for length scales inside a finite
regime.Comment: 12 pages, 4 figure
The time-of-propagation counter for Belle II
The Belle II detector operating at the future upgrade to the KEKB accelerator
will perform high-statistics precision investigations into the flavor sector of
the Standard Model. As charged hadron identification is a vital element of the
experiment's success, the time-of-propagation (TOP) counter has been chosen as
the primary particle identification device in the barrel region of Belle II.
The TOP counter is a compact variant of the detection of internally reflected
Cherenkov light (DIRC) technique and relies heavily on exquisite single photon
timing resolution with micro-channel plate photomultiplier tubes. We discuss
the general principles of TOP operation and optimization of the Belle II TOP
configuration, which is expected to provide 4 sigma or better separation of
kaons and pions up to momenta of approximately 4 GeV/c.Comment: 5 pages, 5 figures, 2 tables; Submitted to special edition of NIMA,
Proceedings of RICH201
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