Abstract Amyloid β protein (Aβ) is considered to be partly responsible for the impairment of learning and memory in Alzheimer disease (AD). In addition, it has been found recently that type 2 ...diabetes mellitus (T2DM) is a risk factor for developing AD. One promising treatment for AD is using analogues for the insulin-release facilitating gut hormone glucagon-like peptide-1 (GLP-1) that has been developed as a T2DM therapy. GLP-1 has been shown to have neuroprotective properties. However, if GLP-1 can protect the late phase-long term potentiation (L-LTP) and related cognitive function against Aβ-induced impairment it is still an open question. To further characterize the neuroprotective function of GLP-1 in the brain, we investigated the effects of i.c.v. injected Val8 -GLP-1(7–36) on the Aβ fragment-induced impairment of in vivo hippocampal L-LTP and spatial learning and memory in rats. The results showed that (1) Aβ1–40 (5 nmol) injection did not affect the baseline field excitatory postsynaptic potentials (fEPSPs), but significantly suppressed multiple high frequency stimulation (HFS)-induced L-LTP in hippocampal CA1 region; (2) Val8 -GLP-1(7–36) (0.05 pmol) administration alone did not affect the baseline synaptic transmission and the maintenance of L-LTP; (3) pretreatment with Val8 -GLP-1(7–36) (0.05 pmol) effectively prevented Aβ1–40-induced deficit of L-LTP; (4) i.c.v. injection of 5 nmol Aβ1–40 resulted in a significant decline learning a spatial Morris water maze (MWM) test; (5) Val8 -GLP-1(7–36) (0.05 pmol) administration alone did not affect spatial learning in this task, while pretreatment with Val8 -GLP-1(7–36) effectively reversed the impairment of spatial learning and memory induced by Aβ1–40. At the same time, the swim speeds and escape latencies of rats among all groups in the visible platform tests did not show any difference. These results suggest that increase of GLP-1 signalling in the brain may be a promising strategy to ameliorate the degenerative processes observed in AD.
•Condensation heat transfer and pressure drop of R170 were studied experimentally.•The effects of vapor quality, mass flux and saturation pressure were investigated.•Predictive models were evaluated ...for condensation heat transfer and pressure drop.•Experimental data are in good agreement with Koyama and Yan-Lin correlations.
Condensation heat transfer and pressure drop of R170 were studied experimentally in a horizontal tube with inner diameter of 4 mm. The tests were conducted at saturation pressures from 1 MPa to 2.5 MPa, mass fluxes from 100 kg (m2∙s)−1 to 250 kg (m2∙s)−1 and average heat fluxes from 55.3 kW m−2 to 96.3 kW m−2 over the entire vapor quality range. The effects of vapor quality, mass flux and saturation pressure on condensation heat transfer and pressure drop were examined and analyzed. The experimental data were compared with various well-known correlations of condensation heat transfer coefficient and pressure drop. The comparison results showed that Koyama et al. correlation agreed with the experimental heat transfer coefficient with a mean absolute relative deviation less than 25%, and the Yan and Lin correlation can accurately predict the experimental pressure drop with a mean absolute relative deviation less than 18%.
Abstract Galactosylated and fluorescein isothiocyanate (FITC) labeled polycaprolactone-g-dextran (Gal-PCL-g-Dex-FITC) polymers were synthesized. The grafted polymers can self-assemble into stable ...micelles in aqueous medium and in serum. Transmission electron microscopy (TEM) images showed that the self-assembled micelles were regularly spherical in shape. Micelle size determined by size analysis was around 120 nm. The anti-inflammation drug prednisone acetate as a model drug was loaded in the polymeric micelles, and the in vitro drug release was investigated. The galactosylated micelles could be selectively recognized by HepG2 cells and subsequently accumulate in HepG2 cells. The in vivo study demonstrated the relative uptake of the micelles by liver is much higher than the other tissues, indicating that the galactosylated micelles have great potential as a liver targeting drug carrier.
The dual objectives of this study are to: (1) examine the relationship between COD and BOD in seawater environment with a rapid but reliable method for the measurement of BOD in seawater, and (2) ...establish the relationship model between BOD(5) and COD in the firth of Dongbao River to predict the values of BOD(5). The first objective is met by the successful development of a technique utilizing bacteria-immobilized membrane flow cell for biodegradation process, coupled with fibre optic fluorescence detection for oxygen depletion quantitation. The technique has been applied to coastal seawater samples collected in the coastal area of Shenzhen, China. The BOD(5) and COD values for the samples are acquired and the results show that there is no apparent linear relationship existing between BOD(5) and COD in relatively clean seawater samples away from the shore. However, in estuary water samples containing relatively high concentration of sewage contamination, a linear correlation does exist between BOD(5) and COD. The linear relationship between the two parameters allows for the calculation of BOD(5) values based on COD data which can be measured more readily and precisely.
Sensor censoring has been introduced for reduced communication rate in a decentralized detection system where decisions made at peripheral nodes need to be communicated to a fusion center. In this ...letter, the fusion of decisions from censoring sensors transmitted over wireless fading channels is investigated. The knowledge of fading channels, either in the form of instantaneous channel envelopes or the fading statistics, is integrated in the optimum and suboptimum fusion rule design. The sensor censoring and the ensuing fusion rule design have two major advantages compared with the previous work. 1) Communication overhead is dramatically reduced. 2) It allows incoherent detection, hence, the phase information of transmission channels is no longer required. As such, it is particularly suitable for wireless sensor network applications with severe resource constraints.
Abstract
We aimed to explore the real experience of patients after liver transplantation in the intensive care unit (ICU).
Objective sampling method was used to select patients transferred to the ICU ...in 10 hospitals in Zhuhai from May 2018 to August 2020. Patients need liver transplantation due to advanced liver cancer and decompensated cirrhosis. The eligibility criteria of patients mainly included liver transplant patients who were clear-minded and willing to participate in the study and had stayed in ICU. Phenomenological research methods and in-depth interviews were used in this qualitative study.
The results showed that the true experience of patients after liver transplantation during ICU stay was summarized into four themes. The strengths of our qualitative research are that we can find the trend from a phenomenon through interviews and other methods to provide a directional foundation for future quantitative research. Its limitations are that it requires a lot of manpower and time, and its objectivity and universality are limited.
Hospitalization experience in the ICU may lead to many negative experiences for liver transplant patients. Nurses should fully understand and pay attention to the psychological changes in patients. Nurses should take effective targeted measures to reduce or eliminate patients’ fear of ICU stay and promote rehabilitation.
Two contrasting barley (
Hordeum vulgare L.) cultivars, i.e. Kepin No. 7 (salt sensitive) and Jian 4 (salt tolerant), were grown hydroponically to study the effect of exogenous silicon (Si) on time ...dependent changes of the activities of major antioxidant enzymes and of lipid peroxidation in roots under salt stress. Enzymes included: superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) and glutathione reductase (GR). Three treatments with three replicates were investigated consisting of a control (basal nutrients with neither NaCl nor Si added), 120 mmol/L
−1 NaCl, and 120 mmol/L
−1 NaCl +1.0 mmol/L
−1 Si. Plant roots were harvested 2, 4 and 6 days after treatment and assayed for activities of the antioxidant enzymes and the concentrations of reduced glutathione (GSH) and malondialdehyde (MDA), and electrolytic leakage percentage (ELP). The activities of SOD, POD and CAT in roots of salt-stressed plants were significantly stimulated at Day 2 compared to control plants, but considerably decreased at Day 4 and onward. GR activity in roots of salt-stressed plants remained unchanged at Day 2, but significantly decreased at Day 4 and onward. However, exogenous Si significantly enhanced these enzyme activities in roots of salt-stressed plants compared to Si-deprived salt treatments. This Si effect was time-dependent and became stronger as the experiments continued. The tendency of change in the activities of antioxidant enzymes and the concentration of GSH coincided with the concentration of MDA, the end product of lipid peroxidation, and the ELP. Higher activities of antioxidant enzymes, and higher concentration of GSH, but lower concentration of MDA and lower ELP were noted in cultivar Jian 4 compared to Kepin No. 7, implying genotypic differences with Jian 4 being less susceptible to stress-dependent membrane lipid peroxidation. The effects of Si-enhanced salt tolerance are discussed with respect to cell membrane integrity, stability and function in barley.
Abstract
China has realized a 56-fold increase in installed wind capacity, from 5.9 GW in 2007 to 328 GW in 2021. In addition to increasing installed capacity, plans to substantially increase wind ...energy production for climate change mitigation also depend on future wind speeds, which strongly influences the efficiencies of installed turbines within individual wind farms. A reversal in globally decreasing wind speeds over several decades has been reported previously. However, subsequent studies using other data sources reported only a slight increase or no reversal in China. These uncertainties regarding China’s wind energy production hamper estimates of wind energy production potential. Here, our analysis of quality-controlled wind speed measurements from
in-situ
stations shows that the wind speed decline in China reversed significantly since 2012 (
P
< 0.001), but with substantial spatio-temporal variability. We further estimated the capacity factor (CF) growth and the wind power gain solely associated with the changes in wind speed ranges from 31.6 to 56.5 TWh yr
−1
based on the 2019 installed capacity. This estimate explains 22.0%–39.3% of the rapid increase in wind generation CF in China during 2012–2019. The result implies that the site selection of wind farms should consider both current wind situation and future wind speed trends. Further studies are needed to understand the driving factor of wind speed recovery in support of the wind energy industry.
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