Defects induced by liquid-phase exfoliation of graphite using sonication were studied. It was shown that localized impact by cavitation shock waves can produce bulk ripplocations and various types of ...dislocations in graphite nanoplatelets. Formation of ripples is more pronounced in large aspect (length/width) ratio platelets or nanobelts. Quasi-periodical ripple systems were observed in many nanobelts after sonication. Mechanism of formation of ripples and dislocations during sonication was proposed. Surprisingly, fast high-temperature processing was found to anneal most of defects. This is consistent with our observations that defects associated with ripplocations are strongly localized and thus can be fast annealed.
Measurement of Γee(J/ψ) with KEDR detector Anashin, V. V; Aulchenko, V. M; Baldin, E. M ...
The journal of high energy physics,
05/2018, Letnik:
2018, Številka:
5
Journal Article
Recenzirano
Odprti dostop
A
bstract
The product of the electronic width of the
J/ψ
meson and the branching fractions of its decay to hadrons and electrons has been measured using the KEDR detector at the VEPP-4M
e
+
e
−
...collider. The obtained values are
Γ
e
e
J
/
ψ
=
5.550
±
0.056
±
0.089
keV
,
Γ
e
e
J
/
ψ
·
ℬ
hadrons
J
/
ψ
=
4.884
±
0.048
±
0.078
keV
,
Γ
e
e
J
/
ψ
·
ℬ
e
e
J
/
ψ
=
0.3331
±
0.0066
±
0.0040
keV
.
The uncertainties shown are statistical and systematic, respectively. Using the result presented and the world-average value of the electronic branching fraction, one obtains the total width of the
J/ψ
meson:
Γ
=
92.94
±
1.83
keV
.
These results are consistent with the previous experiments.
The electronic width of the
J
/
ψ
meson and its product by the branching fractions of
J
/
ψ
meson decay to hadrons and electrons measured with the KEDR detector at the VEPP-4M
e
+
e
−
collider have ...been reported in ref. 1.
The SND is a non-magnetic detector deployed at the VEPP-2000 e^+e^− collider (BINP, Novosibirsk) for hadronic cross-section measurements in the center of mass energy region below 2 GeV. The important ...part of the detector is a three-layer hodoscopic electromagnetic calorimeter (EMC) based on NaI(Tl) counters. Until the recent EMC spectrometric channel upgrade, only the energy deposition measurement in counters was possible. A new EMC signal shaping and digitizing electronics based on FADC allows us to obtain also the event time structure. The new electronics and supporting software, including digital signal processing algorithms, are used for data taking in the ongoing experiment. We discuss the amplitude and time extraction algorithms, the new system performance on experimental events and physical analysis applications.
Aim. To analyze the long-term effect of microvascular injury various types on the structural and functional parameters of the left ventricle assessed by echocardiography in patients with primary ...ST-segment elevation myocardial infarction (STEMI).Materials and methods. The study included 60 patients with primary STEMI admitted within the first 12 hours after the onset of disease who underwent stenting of the infarct-associated coronary artery. Each patient included in the study underwent CMR imaging on the second day post-STEMI. MVO and IMH were assessed using late gadolinium enhancement and T2-weighted CMR imaging. Subsequently, all patients underwent the standard echocardiographic protocol on the 7th day and 3 months after MI. Results. We divided all patients into 4 groups: the 1st group didn’t have any phenomena of IMH and MVO, the 2nd group had only MVO, patients of the 3rd group had only IMH and in the 4th group there was a combination of MVO and IMH. LV ejection fraction was significantly lower in patients with combination of MVO and IMH, if compared to those without it. Correlation analysis showed a moderate inverse correlation between the MVO area and LV contractile function: the larger the area, the lower the LVEF (R=-0,60; p=0,000002).Conclusions. The combination of IMH and MVO is a predictor of a reduction in LVEF and an increase of volumetric measurements within 3 months after MI. In comparison with patients without microvascular injury isolated MVO is associated with lower LVEF. The size of MVO is directly correlated with the LV contractile function decrease. Isolated IMH was not associated with deterioration of left ventricular function.
Aim.
To study brain magnetic resonance imaging (MRI) changes in patients with resistant hypertension (HTN) after renal denervation (RD) and its cerebral protection effectiveness.
Material and ...methods.
The study included 111 patients, of whom 50 were men (45%) and 61 were women (55%), who underwent RD. The mean number of antihypertensive drugs taken regularly was 4,1±1,1. All patients underwent brain MRI and 24-hour ambulatory blood pressure monitoring before and after renal denervation. The data were statistically processed using Statistica 10,0 software.
Results.
After RD, a pronounced antihypertensive effect was observed with a significant reduction in systolic and diastolic blood pressure by 10,3/5,5 and 13,1/7,3 mm Hg at 6 and 12 months, respectively. Office blood pressure, daytime, and nighttime blood pressure levels also decreased (p<0,001). According to MRI data after RD, a decrease in the relative number of patients with I and II degree cerebrospinal fluid circulation changes and an increase in the proportion of patients without detected pathology were noted, but no significant difference in the obtained results was found. A decrease in the linear dimensions of brain ventricles was observed, including a reduction in the size of the left posterior horn of the lateral ventricle (p=0,03) and the third ventricle diameter (p=0,02) at 6 months after RD. At 12 months, the sizes of the anterior horn (p=0,04) and left lateral ventricle body (p=0,017) decreased. A positive effect of RD on the linear dimensions of cerebrospinal fluid system was noted, manifested by a decrease in the mean size of frontal subarachnoid spaces (p=0,028). No significant changes in the frequency and degree of focal lesions and lacunar infarcts were observed after RD (p>0,05).
Conclusion.
RD contributes to a significant decrease in blood pressure levels and exerts a cerebral protective effect by reducing lateral brain ventricles, subarachnoid spaces, and absence of ischemia progression and intracranial hypertension after intervention.
Thermodynamic properties of aqueous solutions of ι-carrageenan as affected by KCl (0.15−1.2 M) or ι-carrageenan (0.5−6 mg/mL) content were studied by high-sensitivity differential scanning ...calorimetry. The polysaccharide was found to undergo two consecutive cooperative conformational transitions, which can be represented by the scheme: H22 ↔ 2H2 ↔ 4C where C is the random coil, H2 is the double helix, and H22 is the double helix dimer. The first transition follows by the “all or none” mechanism. The profile of the second transition resembles that of a second-order phase transition. The parameter σ (of order 1), estimated for this latter transition, suggests that the stacking effect in helices of ι-carrageenan is rather small. The cooperativity of the transition is mainly defined by the loop factor. Free energies of both transitions at 273 K were calculated as a function of salt concentration. These experimental data were found to agree with Manning's theory.
A
bstract
The cross section of the process
e
+
e
−
→
π
+
π
−
has been measured in the Spherical Neutral Detector (SND) experiment at the VEPP-2000
e
+
e
−
collider VEPP-2000 in the energy region 525
...<
s
<
883 MeV. The measurement is based on data with an integrated luminosity of about 4.6 pb
−
1
. The systematic uncertainty of the cross section determination is 0.8% at
s
>
0
.
600 GeV. The
ρ
meson parameters are obtained as
m
ρ
= 775
.
3 ± 0
.
5 ± 0
.
6 MeV, Γ
ρ
= 145
.
6 ± 0
.
6 ± 0
.
8 MeV,
B
ρ
→
e
+
e−
×
B
ρ
→
π
+
π−
= (4
.
89 ± 0
.
02 ± 0
.
04) × 10
−
5
, and the parameters of the
e
+
e
−
→
ω
→
π
+
π
−
process, suppressed by
G
-parity, as
B
ω
→
e
+
e−
×
B
ω
→
π
+
π−
= (1
.
32 ± 0
.
06 ± 0
.
02) × 10
−
6
and and
ϕ
ρω
= 110
.
7 ± 1
.
5 ± 1
.
0 degrees.
Spherical neutral detector for VEPP-2M collider Achasov, M.N; Aulchenko, V.M; Baru, S.E ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
07/2000, Letnik:
449, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The Spherical Neutral Detector (SND) operates at VEPP-2M collider in Novosibirsk studying e
+e
− annihilation in the energy range up to 1.4
GeV. Detector consists of a fine granulated spherical ...scintillation calorimeter with 1632 NaI(Tl) crystals, two cylindrical drift chambers with 10 layers of sense wires, and a muon system made of streamer tubes and plastic scintillation counters. The detector design, performance, data acquisition and processing are described.
The present article deals with the technology of obtaining decellularized cell-free collagen-based scaffolds from arterial vessels and surgical assessment of the possibility of experimentally ...implanting them into the blood system of laboratory animals for experimental purposes. The study was performed on arterial vessels (n=60) and fragments of the human internal thoracic artery (n=20). Described herein is a method of obtaining a connective-tissue matrix of a blood vessel by means of vessel's perfusion for 2-3 hours with detergent solutions. Cell-free collagen-based conduits were implanted to a total of ten dogs. After the operation, the blood flow remained functional. The anastomoses established turned out to be leak-proof and the acellular vessels were able to withstand the haemodynamic load of the arterial blood flow.
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