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This paper proposes to improve the corrosion resistance of stainless steel using the photocathodic protection (PCP) method with CdS/PbS/titanium dioxide (TiO2) as the photoanode material. Cadmium sulfide (CdS)/lead sulfide (PbS) quantum dot (QD) heterostructure layered on TiO2 enhanced the photoelectrochemical performance and improved the PCP of 304 stainless steel. The photoanode film can protect 304 stainless steel for a period of upto 3 months against corrosion. This work demonstrates that CdS/PbS/TiO2 tandem heterostructure is a promising durable and stable photoanode, which can protect stainless steel in both dark and illuminated conditions.
Under conventional solidification conditions, immiscible alloy melt would undergo large-scale composition segregation after liquid–liquid phase separation, resulting in the loss of properties and application value. In the present study, the ternary immiscible Al70Bi10Sn20 alloy was chosen to study the effect of cooling rate on its resultant microstructure by casting the melt under different cooling conditions. The results indicated that the Al–Bi–Sn alloy with a slow cooling rate exhibits a strong spatial phase separation trend during solidification. However, as the cooling rate increases, the decreasing volume fraction of the segregated Bi–Sn-rich regions indicates the efficient suppression of spatial phase separation. The relatively dispersed distribution of Bi–Sn phase in the Al-rich matrix can be obtained by quenching the melt into water. The influence mechanism of cooling rate on the microstructure of the alloy is also discussed. The present study is beneficial to further tailoring the microstructure of immiscible alloys.
The growing number of mass gathering events (MGEs) in Victoria has seen an increase in demand for event health services and the need for real-time reporting of medical incidents at these events.
Since 2016, St. John Ambulance Victoria has introduced an electronic patient care record (ePCR) system with the aim of improving patient care and satisfaction. It appears that this ePCR system is the first of its kind to be trialed at MGEs by a volunteer organization.
A qualitative study was conducted to determine strengths and limitations of the ePCR system by compiling results of surveys and interviews and through anonymous feedback from volunteers and patrons (event organizers, patients). This study is ongoing.
It was found that the use of ePCR:
1.Allowed for collection of relevant data to assist in future planning of MGEs
2.Aids the overall coordination of first aid delivery at MGEs
-faster relaying of patient information to event commanders
-reduction of paperwork
-improved ability to locate first aid crews using GPS tracking
3.Received positive feedback from first aiders, event organizers, and patrons
4.Was deemed easy-to-use (4/5), acceptable (4.3/5), and helpful (4.1/5) by our members
These experiences demonstrate that ePCR is well-received, easy to use, and leads to improved patient satisfaction and treatment outcomes at MGEs. Furthermore, the ability to collect and analyze real-time data such as GPS location tracking, incidence heat maps, and patient demographics facilitate future event planning and resource allocation at MGEs. It is acknowledged that this study is preliminary, and the trialed use of an ePCR system has been limited to metropolitan areas and MGEs with <1 million patrons. The intent is to continue this study and explore the use of ePCRs at larger MGEs and events in rural or regional areas.
St. John Ambulance Victoria provides first aid and medical services at a variety of mass gathering events (MGEs) throughout Victoria. Volunteer healthcare professionals and students (termed “volunteers”) form Medical Assistance Teams (MAT) at these MGEs. MAT deployments manage a variety of patient presentations which include critically ill patients. This reduces high acuity patient transfers to the hospital and, where possible, avoid ambulance and hospital utilization.
To determine the effectiveness of interdisciplinary prehospital simulation workshops in preparing volunteers for MAT deployment at MGEs.
A one-day, simulation-based training session within the MAT environment was implemented to introduce volunteers to the management of various scenarios faced at MGEs. All volunteers were provided an orientation to the equipment and setting up MAT deployments at MGEs. Volunteers then participated in interdisciplinary group-based scenarios such as cardiac arrest management, drug intoxication, spinal injuries, agitated patients, and airway management. To determine the effectiveness of this training session, volunteers were invited to participate in a post-training survey, comprising of Likert scores and open-ended responses.
Seventeen volunteers attended the training session with 10 (58.8%) completing the post-training survey. Volunteers were satisfied with environment familiarization in the MAT (Average 4.47/5.00) and found the simulation-based training helpful (Average 3.67/4.00). The induction overall was well-received (4.60/5.00) with volunteers feeling more confident in being deployed at MGEs (4.20/5.00).
The results of the simulation-based training session were positive with volunteers receptive to the need for a training day prior to MAT deployment at MGEs. The simulation session enables volunteers to be comfortable with working in MAT and managing a diverse range of patients at MGEs. This session is likely to improve interdisciplinary communication and teamwork in the MAT. Future research is aimed at following these volunteers after several MAT deployments to improve the training session for future participants.
Muscle fibre types can transform from slow-twitch (slow myosin heavy chain (MyHC)) to fast-twitch (fast MyHC) or vice versa. Leucine plays a vital effect in the development of skeletal muscle. However, the role of leucine in porcine myofibre type transformation and its mechanism are still unclear. In this study, effects of leucine and microRNA-27a (miR-27a) on the transformation of porcine myofibre type were investigated in vitro. We found that leucine increased slow MyHC protein level and decreased fast MyHC protein level, increased the levels of phospho-protein kinase B (Akt)/Akt and phospho-forkhead box 1 (FoxO1)/FoxO1 and decreased the FoxO1 protein level. However, blocking the Akt/FoxO1 signalling pathway by wortmannin attenuated the role of leucine in porcine myofibre type transformation. Over-expression of miR-27a decreased slow MyHC protein level and increased fast MyHC protein level, whereas inhibition of miR-27a had an opposite effect. We also found that expression of miR-27a was down-regulated following leucine treatment. Moreover, over-expression of miR-27a repressed transformation from fast MyHC to slow MyHC caused by leucine, suggesting that miR-27a is interdicted by leucine and then contributes to porcine muscle fibre type transformation. Our finding provided the first evidence that leucine promotes porcine myofibre type transformation from fast MyHC to slow MyHC via the Akt/FoxO1 signalling pathway and miR-27a.
We analyzed research themes in the field of disaster medicine in China to provide references for researchers to understand the research status and developing trends of this field.
Published journal articles were retrieved. A social network analysis was conducted to visualize the relations of high-frequency key words. A cluster analysis was used to classify key words. A strategic diagram analysis was conducted to visualize clusters across the entire research field.
We retrieved 3,079 articles, from which 1,749 articles and 8,284 key words were identified after screening. High-frequency key words were classified into 6 clusters. “Medical rescue” had the highest degree and betweenness centralities. Cluster 4 was located in Quadrant I of the strategic diagrams.
“Medical rescue” is the core key word, and it serves a pivotal “bridge” function. “Emergencies” and similar terms are key words with special statuses. “Natural disaster medical rescue” and “fundamental theories of disaster medicine” constitute the primary and secondary core themes, respectively. “On-site emergency treatment techniques” is a marginalized theme. The other themes are emerging themes that offer considerable scope for future development. Generally, the scope and depth of investigations in this field should be improved. (Disaster Med Public Health Preparedness. 2019;13:405-409)
Leucine, one of the branched-chain amino acids, is the only amino acid to regulate protein turnover in skeletal muscle. Leucine not only increases muscle protein synthesis, but also decreases muscle protein degradation. It is well documented that leucine plays a positive role in differentiation of murine muscle cells. However, the role of leucine on porcine myoblast differentiation and its mechanism remains unclear. In this study, porcine myoblasts were induced to differentiate with differentiation medium containing different concentrations of leucine, and wortmannin was used to interdict the activity of protein kinase B (Akt). We found that leucine increased the number of myosin heavy chain-positive cells and creatine kinase activity. Moreover, leucine increased the mRNA and protein levels of myogenin and myogenic determining factor (MyoD). In addition, leucine increased the levels of phosphorylated Akt/Akt and phosphorylated Forkhead box O1 (P-FoxO1)/FoxO1, as well as decreased the protein level of FoxO1. However, wortmannin, a specific repressor of PI3K/Akt signalling pathway, attenuated the positive role of leucine on porcine myoblast differentiation. Our results suggest that leucine promotes porcine myoblast differentiation through the Akt/FoxO1 signalling pathway.
MicroRNA (miR)-29b plays a crucial role during somatic cell reprogramming. The aim of the current study was to explore the effects of miR-29b on the developmental competence of bovine somatic cell nuclear transfer (SCNT) embryos, as well as the underlying mechanisms of action. The expression level of miR-29b was lower in bovine SCNT embryos at the pronuclear, 8-cell, and blastocyst stages compared with in vitro fertilized embryos. In addition, miR-29b regulates the expression of DNA methyltransferases (Dnmt3a/3b and Dnmt1) in bovine SCNT embryos. We further investigated SCNT embryo developmental competence and found that miR-29b overexpression during bovine SCNT embryonic development does not improve developmental potency and downregulation inhibits developmental potency. Nevertheless, the quality of bovine SCNT embryos at the blastocyst stage improved significantly. The expression of pluripotency factors and cellular proliferation were significantly higher in blastocysts from the miR-29b overexpression group than the control and downregulation groups. In addition, outgrowth potential in blastocysts after miR-29b overexpression was also significantly greater in the miR-29b overexpression group than in the control and downregulation groups. Taken together, these results demonstrated that miR-29b plays an important role in bovine SCNT embryo development.
The intestine plays key roles in maintaining body arginine (Arg) homoeostasis. Meanwhile, the intestine is very susceptible to reactive oxygen species. In light of this, the study aimed to explore the effects of Arg supplementation on intestinal morphology, Arg transporters and metabolism, and the potential protective mechanism of Arg supplementation in piglets under oxidative stress. A total of thirty-six weaned piglets were randomly allocated to six groups with six replicates and fed a base diet (0·95 % Arg,) or base diet supplemented with 0·8 % and 1·6 % l-Arg for 1 week, respectively. Subsequently, a challenge test was conducted by intraperitoneal injection of diquat, an initiator of radical production, or sterile saline. The whole trial lasted 11 d. The diquat challenge significantly decreased plasma Arg concentration at 6 h after injection (P<0·05), lowered villus height in the jejunum and ileum (P<0·05) as well as villus width and crypt depth in the duodenum, jejunum and ileum (P<0·05). Oxidative stress significantly increased cationic amino acid transporter (CAT)-1, CAT-2 and CAT-3, mRNA levels (P<0·05), decreased arginase II (ARGII) and inducible nitric oxide synthase mRNA levels, and increased TNF-α mRNA level in the jejunum (P<0·05). Supplementation with Arg significantly decreased crypt depth (P<0·05), suppressed CAT-1 mRNA expression induced by diquat (P<0·05), increased ARGII and endothelial nitric oxide synthase mRNA levels (P<0·05), and effectively relieved the TNF-α mRNA expression induced by diquat in the jejunum (P<0·05). It is concluded that oxidative stress decreased Arg bioavailability and increased expression of inflammatory cytokines in the jejunum, and that Arg supplementation has beneficial effects in the jejunum through regulation of the metabolism of Arg and suppression of inflammatory cytokine expression in piglets.
Erection planning in shipbuilding is a highly complex process. When a process change happens for some reason, it is often difficult to identify how many factors are affected and estimate how sensitive these factors can be. To optimize the planning and replanning of the shipbuilding plan for the best production performance, a data-driven approach for shipbuilding erection planning is proposed, which is composed of an erection plan model, identification of major factors related to the erection plan, and a data-driven algorithm to apply shipbuilding operation data for creating plans and forecasting, for plan adjustment, future availabilities of shipyard resources including machines, equipment, and man power. Through data clustering, the relevant factors are identified as a result of plan change, and critical equipment health management is carried out through data-driven anomaly detection. A case study is implemented, and the result shows that the proposed data-driven method is able to reschedule the shipbuilding plans smoothly.
Continuous repetitive upsetting and extrusion (CRUE) processing was performed to investigate its effects on microstructures, mechanical properties and texture characteristics of a 2A66 Al–Li alloy. The results show that the average grain size is effectively refined from initial as-extruded ∼140 µm to ∼4 µm after 3 CRUE passes. The grain refinement is the combined effect of continuous dynamic recrystallization and discontinuous dynamic recrystallization. The texture intensity tends to be weaker and new cube texture is gradually developed with increasing CRUE passes. In addition, the fraction of high angle grain boundaries increases to 86.37% after 3 CRUE passes. Tensile test results reveal that the ductility is greatly enhanced with modest reduction in strength after CRUE processing. The variation in mechanical properties may be mainly due to the decrease of dislocation density and weakening of texture.
The microstructure evolution of a typical nickel-based superalloy was studied in the temperature range of 960–1160 °C with the strain rate of 0.001 s−1 by using electron backscattered diffraction technique. Based on the grain orientation spread method, the dynamic recrystallization (DRX) grains were distinguished from the deformed grains. The results revealed that the volume fraction and the size of DRX grains increased with the increasing deformation temperatures. Most of the original Σ3 boundaries lost their twin characteristics due to crystal rotations during hot deformation. Meanwhile, lots of new Σ3 boundaries were formed in the DRX grains mainly by growth accidents. Moreover, the deformation temperature had a similar effect on the fraction of Σ3 boundary and the Σ3 boundary density in the DRX domains, which increased firstly and then decreased with the increasing deformation temperature. The Σ3 boundary density was analyzed as a function of grain size, and the critical grain size below which no twin forms was calculated to be 2.06 µm. In addition, the coherent Σ3 boundaries were easier to form at the higher deformation temperature due to their lower boundary energy.
Central China has experienced stronger summer monsoon during warm periods such as Marine Isotope Stages (MIS) 1 and 3, and weaker summer monsoon during cool periods such as MIS 2. The evolution history of Dajiuhu subalpine peatland in central China can help investigate how the expansion and shrinkage of peatland were associated with monsoonal strength over the last glacial–interglacial cycle. Here we apply bulk organic carbon and molecular biomarkers (hopane and n-alkane) to reconstruct the evolution history for the Dajiuhu peatland over the past 40,000 yr. The results indicate fluctuations between lacustrine and peat-like deposition during MIS 3, steady lacustrine deposition during MIS 2, and peatland initiation and expansion during MIS 1 in the Dajiuhu peatland. Therefore, at the glacial–interglacial scale, warmer summer and cooler winter conditions in interglacial periods are crucial to trigger peat deposition, whereas reduced evaporation in glacial period instead of decreased monsoonal-driven precipitation would have played a predominant role in the regional effective moisture balance. However, within the Holocene (MIS 1), monsoonal precipitation changes appear to be the main controller on millennial-scale variations of water-table level of the Dajiuhu peatland.
Proton radiography is used for advanced hydrotesting as a new type radiography technology due to its powerful penetration capability and high detection efficiency. A new proton radiography terminal will be developed to radiograph static samples at the Institute of Modern Physics of Chinese Academy of Science. The proton beam with the maximum energy of 2.6 GeV will be produced by Heavy Ion Research Facility in Lanzhou-Cooling Storage Ring. The proton radiography terminal consists of the matching magnetic lens and the Zumbro lens system. In this paper, the design scheme and all optic parameters of this beam terminal for 2.6 GeV proton energy are presented by simulating the beam optics using WINAGILE code. My-BOC code is used to test the particle tracking of proton radiography beam line. Geant4 and G4beamline codes are used for simulating the proton radiography system. The results show that the transmission efficiency of proton without target is 100%, and the effect of secondary particles can be neglected. To test this proton radiography system, the proton images for an aluminum plate sample with two rectangular orifices and a step brass plate sample are respectively simulated using Geant4 code. The results show that the best spatial resolution is about 36 μm, and the differences of the thickness are not >10%.
Hydroxytyrosol (HT) is a major polyphenolic compound found in olive oil with reported anti-cancer and anti-inflammatory activities. However, the neuroprotective effect of HT on type 2 diabetes remains unknown. In the present study, db/db mice and SH-SY-5Y neuroblastoma cells were used to evaluate the neuroprotective effects of HT. After 8 weeks of HT administration at doses of 10 and 50 mg/kg, expression levels of the mitochondrial respiratory chain complexes I/II/IV and the activity of complex I were significantly elevated in the brain of db/db mice. Likewise, targets of the antioxidative transcription factor nuclear factor erythroid 2 related factor 2 including p62 (sequestosome-1), haeme oxygenase 1 (HO-1), and superoxide dismutases 1 and 2 increased, and protein oxidation significantly decreased. HT treatment was also found to activate AMP-activated protein kinase (AMPK), sirtuin 1 and PPARγ coactivator-1α, which constitute an energy-sensing protein network known to regulate mitochondrial function and oxidative stress responses. Meanwhile, neuronal survival indicated by neuron marker expression levels including activity-regulated cytoskeleton-associated protein, N-methyl-d-aspartate receptor and nerve growth factor was significantly improved by HT administration. Additionally, in a high glucose-induced neuronal cell damage model, HT effectively increased mitochondrial complex IV and HO-1 expression through activating AMPK pathway, followed by the prevention of high glucose-induced production of reactive oxygen species and declines of cell viability and VO2 capacity. Our observations suggest that HT improves mitochondrial function and reduces oxidative stress potentially through activation of the AMPK pathway in the brain of db/db mice.
The effect of tea intake on blood pressure (BP) is controversial. We performed a meta-analysis of randomised controlled trials to determine the changes in systolic and diastolic BP due to the intake of black and green tea. A systematic search was conducted in MEDLINE, EMBASE and the Cochrane Controlled Trials Register up to May 2014. The weighted mean difference was calculated for net changes in systolic and diastolic BP using fixed-effects or random-effects models. Previously defined subgroup analyses were performed to explore the influence of study characteristics. A total of twenty-five eligible studies with 1476 subjects were selected. The acute intake of tea had no effects on systolic and diastolic BP. However, after long-term tea intake, the pooled mean systolic and diastolic BP were lower by − 1·8 (95 % CI − 2·4, − 1·1) and − 1·4 (95 % CI − 2·2, − 0·6) mmHg, respectively. When stratified by type of tea, green tea significantly reduced systolic BP by 2·1 (95 % CI − 2·9, − 1·2) mmHg and decreased diastolic BP by 1·7 (95 % CI − 2·9, − 0·5) mmHg, and black tea showed a reduction in systolic BP of 1·4 (95 % CI − 2·4, − 0·4) mmHg and a decrease in diastolic BP of 1·1 (95 % CI − 1·9, − 0·2) mmHg. The subgroup analyses showed that the BP-lowering effect was apparent in subjects who consumed tea more than 12 weeks (systolic BP − 2·6 (95 % CI − 3·5, − 1·7) mmHg and diastolic BP − 2·2 (95 % CI − 3·0, − 1·3) mmHg, both P< 0·001). The present findings suggest that long-term ( ≥ 12 weeks) ingestion of tea could result in a significant reduction in systolic and diastolic BP.
Previous studies have reported that the first polar body (PB1) morphology reflects embryo development competence, but the effects of PB1 on porcine embryo development remain unknown. This study aims to determine whether the ability of porcine embryo development is related to oocytes’ PB1 in vitro. The distribution of type II cortical granules (CGs) of porcine matured oocytes in grade B PB1 is significantly greater compared with those in grades A and C PB1 (71.43% versus 52.46% and 50%; P < 0.05). The ratio of porcine parthenogenetic blastocysts and the mean cell number in each blastocyst in the group with grade B PB1 is significantly greater than that with grades A and C PB1 (30.81% vs. 19.02% and 15.15%; P < 0.05) and (36.67 versus 24.67, 28.67; P < 0.05), and no significant differences are found in the embryo cleavage for all groups (79.75%, 84.30%, and 78.18% in grades A, B, and C PB1; P > 0.05). The acetylation level of porcine embryos in the group with grade B PB1 is significantly greater compared with those in the other groups (P < 0.05), and is almost 2.5 times higher than that in grade A. Therefore, porcine oocytes with PB1 in grade B are more competitive in cytoplasmic maturation and further embryo development in vitro.
In the present study, twenty-four Duroc × Landrance × Yorkshire (initial body weight (BW) of 21·82 (sem 2·06) kg) cross-bred pigs were used to determine whether dietary vitamin D supplementation could confer protection against viral infections through the retinoic acid-inducible gene I (RIG-I) signalling pathway in pigs. Experimental treatments were arranged in a 2 × 2 factorial manner with the main effects of immune challenge (control v. porcine rotavirus (PRV) challenge) and dietary concentrations of vitamin D (200 and 5000 IU; where 1 IU of vitamin D is defined as the biological activity of 0.025 mg of cholecalciferol). The pigs were fed a diet containing 200 or 5000 IU vitamin D in the first week of the study period. On day 8, the pigs were orally dosed with 4 ml of Dulbecco's modified Eagle's medium/Ham's F-12 medium containing PRV or essential medium (control). Serum samples were collected on day 8 (pre-challenge), and 6 d after the PRV challenge, the pigs were killed to evaluate intestinal morphology and tissue gene expression following the last blood collection. Pigs challenged with PRV had decreased BW gain (P< 0·01), feed intake (P< 0·01), villus height (P< 0·01), faecal consistency (P< 0·05), and serum 1,25-dihydroxyvitamin D concentration (P< 0·01) and increased (P< 0·01) serum IL-2, IL-6 and interferon (IFN)-β concentrations. Vitamin D supplementation mitigated these effects. The mRNA expression of RIG-I (P< 0·01), IFN-β promoter stimulator 1 (P< 0·01), IFN-β (P< 0·01) and interferon-stimulated gene 15 (ISG15) (P< 0·01) was up-regulated by the PRV challenge and vitamin D supplementation in the intestine. In conclusion, vitamin D supplementation could activate the RIG-I signalling pathway and thus alleviate the negative effects caused by PRV challenge.