Toroidal field and q95 scalings of error field penetration are investigated with n = 1 resonant magnetic perturbation coil in EAST. The toroidal field scalings of error field penetration thresholds ...under fixed q95 are about br21/BT∝BT−1.0 in both ohmically and lower hybrid wave heated plasmas, where br21 is the vacuum error field at the q = 2/1 rational surface and BT is the toroidal field. These scalings indicate a favorable tolerance on error field in ITER. To make clear the underlying physics on toroidal field scaling, the theoretical analysis is given. By subtituting penetration related scaling parameters into the theory, the obtained theoretical scalings are consistent with the experimental observations using the vacuum penetration thresholds. To further investigate penetration threshold in larger operation region, the q95 scaling on penetration threshold with br21∝q951.66 has also been observed. The rational surface radius rs and magnetic shear s, which are crucial to q95 scaling, are included in the theoretical analysis. The theoretical analysis is also consistent with the experimental scalings using the vacuum penetration thresholds. Moreover, the obtained theoretical scalings are easy to compare with experimental scalings. These theoretical analyses will stimulate the extrapolation of error field tolerance towards future reactors.
Density scaling of error field penetration in EAST is investigated with different n = 1 magnetic perturbation coil configurations in ohmically heated discharges. The density scalings of error field ...penetration thresholds under two magnetic perturbation spectra are br∝ne0.5 and br∝ne0.6, where br is the error field and ne is the line averaged electron density. One difficulty in understanding the density scaling is that key parameters other than density in determining the field penetration process may also be changed when the plasma density changes. Therefore, they should be determined from experiments. The estimated theoretical analysis (br∝ne0.54 in lower density region and br∝ne0.40 in higher density region), using the density dependence of viscosity diffusion time, electron temperature and mode frequency measured from the experiments, is consistent with the observed scaling. One of the key points to reproduce the observed scaling in EAST is that the viscosity diffusion time estimated from energy confinement time is almost constant. It means that the plasma confinement lies in saturation ohmic confinement regime rather than the linear Neo-Alcator regime causing weak density dependence in the previous theoretical studies.
Abstract
This paper presents the penetration of
n
= 2 magnetic field perturbations, where
n
is the toroidal mode number. The
n
= 2 intrinsic error field (IEF) is measured in an ohmic heating plasma ...using the compass scan method, i.e. the toroidal asymmetry in the threshold current for the penetration of
n
= 2 resonant magnetic perturbations (RMPs). Its amplitude is 55.5 A in equivalent coil current or
B
r,3/2
= 0.1 G and the toroidal phase of the IEF is around 170.6° (129°). Phasing scans (scans of the phase difference between the upper and lower coil currents) of the
n
= 2 RMPs are carried out to obtain the
e
ffects of the
n
= 2 spectrum on field penetration. The observed dependence of the field penetration on the spectrum is consistent with those of simulations using the MARS-F code. One of the interesting phenomena is that the
n
= 2 mode often stimulates an
n
= 1 mode. The dominant poloidal harmonic of the
n
= 1 mode is
m
= 2, and the dominant poloidal harmonic of the
n
= 2 mode is
m
= 3. The evolution of the
n
= 1 mode has two stages, i.e., an initial small island growth stage, and a later saturation stage. In the initial stage, the amplitude of the
n
= 1 magnetic island grows, while the phase remains fixed. When the amplitude of the magnetic island exceeds a certain threshold, it enters the second stage, in which the magnetic island is locked into another phase and its amplitude starts to saturate. The phase in the initial small island stage depends linearly on the phase of the applied
n
= 2 RMP, which suggests that the
n
= 2 mode is directly driven by the coupling between the
n
= 1 and
n
= 2 modes. The phase in the second stage is either locked to the phase close to the previously measured
n
= 1 IEF, or is locked to the phase close to the
n
= 2 response field. This suggests that the final phase of the
n
= 1 mode depends on competition between the locking effect induced by the
n
= 1 IEF and the nonlinear coupling effect between the two modes. This might be an issue in the MHD control application using high-
n
RMPs in the future ITER device.
Systematic evaluation of long-term outcomes in survivors of H1N1 is still lacking. This study aimed to characterize long-term outcomes of severe H1N1-induced pneumonia and acute respiratory distress ...syndrome (ARDS).
This was a single-center, prospective, cohort study. Survivors were followed up for four times after discharge from intensive care unit (ICU) by lung high-resolution computed tomography (HRCT), pulmonary function assessment, 6-minute walk test (6MWT), and SF-36 instrument.
A total of 60 survivors of H1N1-induced pneumonia and ARDS were followed up for four times. The carbon monoxide at single breath (D
) of predicted values and the 6MWT results didn't continue improving after 3 months. Health-related quality of life didn't change during the 12 months after ICU discharge. Reticulation or interlobular septal thickening on HRCT did not begin to improve significantly until the 12-month follow-up. The D
of predicted values showed negative correlation with the severity degree of primary disease and reticulation or interlobular septal thickening, and a positive correlation with physical functioning. The D
of predicted values and reticulation or interlobular septal thickening both correlated with the highest tidal volume during mechanical ventilation. Levels of fibrogenic cytokines had a positive correlation with reticulation or interlobular septal thickening.
The improvements in pulmonary function and exercise capacity, imaging, and health-related quality of life had different time phase and impact on each other during 12 months of follow-up. Long-term outcomes of pulmonary fibrosis might be related to the lung injury and excessive lung fibroproliferation at the early stage during ICU admission.
In agricultural production, temperature and moisture are important factors affecting grain yield and quality. Although moderate drought at the grain-filling stage can effectively alleviate the damage ...caused by high temperature, the specific regulatory mechanism driving the effect of moderate drought at the high temperature on starch synthesis is still unclear. To explore the effects and mechanisms of high temperature and moderate drought on rice starch synthesis at the grain-filling stage, the activities of enzymes and expression levels of the genes involved in starch synthesis under four different treatments involving high temperature and/or water stress (CK, HT, WS, and HT+WS) were investigated in this study. The starch synthesis of a japonica inbred rice was measured under the four treatments during the grain filling. The results show that the effects of high temperature and moderate drought on grain filling mainly occur in the inferior grains of rice. Through the regulation of enzymes involved in starch synthesis and the expression levels of their main genes, the synthesis of rice starch can be affected. Therefore, the high temperature and moderate drought were antagonistic, and moderate drought can alleviate the damage to grain quality at a high temperature by improving the starch synthesis of inferior grains in japonica rice. This study provides a basis for stress-resistance cultivation and breeding strategies of rice with high temperature tolerance.
The generation of runaway electrons (REs) is observed during the low-density helium ohmic plasma discharge in the Experimental Advanced Superconducting Tokamak (EAST). The growth rate of hard x-ray ...(HXR) is inversely proportional to the line-average density. Besides, the RE generation in helium plasma is higher than that in deuterium plasma at the same density, which is obtained by comparing the growth rate of HXR with the same discharge conditions. The potential reason is the higher electron temperature of helium plasma in the same current and electron density plateau. Furthermore, two Alfvén eigenmodes driven by REs have been observed. The frequency evolution of the mode is not fully satisfied with the Alfvén scaling and when extension of the Alfvén frequency is towards 0, the high frequency branch is ∼50 kHz. The different spatial position of the two modes and the evolution of the helium concentration could be used to understand deviation between theoretical and experimental observation.
Abstract
Histone deacetylase 3 (HDAC3) is a major HDAC, whose enzymatic activity is targeted by small molecule inhibitors for treating a variety of conditions. However, its enzymatic activity is ...largely dispensable for its function in embryonic development and hepatic lipid metabolism. HDAC3 plays a pivotal role in regulating muscle fuel metabolism and contractile function. Here, we address whether these muscular functions of HDAC3 require its enzymatic activity. By mutating the NCoR/SMRT corepressors in a knock-in mouse model named NS-DADm, we ablated the enzymatic activity of HDAC3 without affecting its protein levels. Compared to the control mice, skeletal muscles from NS-DADm mice showed lower force generation, enhanced fatigue resistance, enhanced fatty acid oxidation, reduced glucose uptake during exercise, upregulated expression of metabolic genes involved in branched-chain amino acids catabolism, and reduced muscle mass during aging, without changes in the muscle fiber-type composition or mitochondrial protein content. These muscular phenotypes are similar to those observed in the HDAC3-depleted skeletal muscles, which demonstrates that, unlike that in the liver or embryonic development, the metabolic function of HDAC3 in skeletal muscles requires its enzymatic activity. These results suggest that drugs specifically targeting HDAC3 enzyme activity could be developed and tested to modulate muscle energy metabolism and exercise performance.
Abdominal compartment syndrome (ACS) and intra abdominal hypertension(IAH) are common clinical findings in patients with severe acute pancreatitis(SAP). It is thought that an increased intra ...abdominal pressure(IAP) is associated with poor prognosis in SAP patients. But the detailed effect of IAH/ACS on different organ system is not clear. The aim of this study was to assess the effect of SAP combined with IAH on hemodynamics, systemic oxygenation, and organ damage in a 12 h lasting porcine model.
Following baseline registrations, a total of 30 animals were divided into 5 groups (6 animals in each group): SAP+IAP30 group, SAP+IAP20 group, SAP group, IAP30 group(sham-operated but without SAP) and sham-operated group. We used a N(2) pneumoperitoneum to induce different levels of IAH and retrograde intra-ductal infusion of sodium taurocholate to induce SAP. The investigation period was 12 h. Hemodynamic parameters (CO, HR, MAP, CVP), urine output, oxygenation parameters(e.g., S(v)O(2), PO(2), PaCO(2)), peak inspiratory pressure, as well as serum parameters (e.g., ALT, amylase, lactate, creatinine) were recorded. Histological examination of liver, intestine, pancreas, and lung was performed.
Cardiac output significantly decreased in the SAP+IAH animals compared with other groups. Furthermore, AST, creatinine, SUN and lactate showed similar increasing tendency paralleled with profoundly decrease in S(v)O(2). The histopathological analyses also revealed higher grade injury of liver, intestine, pancreas and lung in the SAP+IAH groups. However, few differences were found between the two SAP+IAH groups with different levels of IAP.
Our newly developed porcine SAP+IAH model demonstrated that there were remarkable effects on global hemodynamics, oxygenation and organ function in response to sustained IAH of 12 h combined with SAP. Moreover, our model should be helpful to study the mechanisms of IAH/ACS-induced exacerbation and to optimize the treatment strategies for counteracting the development of organ dysfunction.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Intrinsic error field on EAST is measured using the 'compass scan' technique with different n = 1 magnetic perturbation coil configurations in ohmically heated discharges. The intrinsic error field ...measured using a non-resonant dominated spectrum with even connection of the upper and lower resonant magnetic perturbation coils is of the order br2,1/BT≃10−5 and the toroidal phase of intrinsic error field is around 60°. A clear difference between the results using the two coil configurations, resonant and non-resonant dominated spectra, is observed. The 'resonant' and 'non-resonant' terminology is based on vacuum modeling. The penetration thresholds of the non-resonant dominated cases are much smaller than that of the resonant cases. The difference of penetration thresholds between the resonant and non-resonant cases is reduced by plasma response modeling using the MARS-F code.
Background
Intra-abdominal hypertension (IAH) is common in patients with severe acute pancreatitis (SAP). The aim of the present study was to investigate the risk factors of IAH in SAP patients and ...assess the prognosis of SAP combined with IAH.
Methods
To analyze the data from patients with SAP, both univariate and multivariate logistic regression analyses were applied, using 16 indices, including age, gender, Acute Physiology and Chronic Health Evaluation II scores (APACHE II), 24 h fluid balance, hematocrit, serum calcium level, and so on. Clinical prognosis such as mortality, hospital duration, of SAP patients with or without IAH was also compared.
Results
First 24 h fluid balance (Odds Ratio OR, 1.003; 95% Confidence Interval CI, 1.001–1.006), number of fluid collections (OR, 1.652; 95% CI, 1.023–2.956), and serum calcium level (OR, 0.132; 95% CI, 0.012–0.775) were found to be independent risk factors for IAH in patients with SAP. Moreover, patients with SAP and IAH had significantly longer average length of stay, both in the hospital and in the intensive care unit, higher rates of systemic and local complications, and more invasive treatments.
Conclusions
The significant risk factors for IAH in patients with SAP include 24 h fluid balance (first day), number of fluid collections, and serum calcium level. Additionally, IAH is associated with extremely poor prognosis, evidenced by high rates of mortality, morbidity, and the need for invasive interventions.
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