AlxCrFeNi eutectic multi-component alloys were prepared to obtain excellent mechanical properties by double-phase strengthening. The X-ray diffraction results showed that the crystal structure were ...both body-centered cubic and energy-dispersive X-ray spectrometer identified that the two phases are ordered NiAl intermetallic and disordered Fe, Cr solid solution. The formation of eutectic structures was introduced by a simplified dynamic model. After mechanical tests, the alloys presented excellent compressive strength and unexpected large deformation. Due to the solid solution and fine-grain strengthening resulted by Al addition, mechanical properties of AlxCrFeNi alloys exhibited regularity in some degree. Among all alloys, Al1.3CrFeNi has the highest fracture strength and Al0.9CrFeNi has the most excellent strain. Besides, Al1.2CrFeNi alloy showed a good combination of strength and ductility.
Summary
Vitiligo is a common depigmenting disorder with profound psychosocial impacts. Previous observational studies have suggested a link between vitiligo and psychiatric morbidity, such as ...depression. However, variability in study design makes it difficult to quantify accurately the relationship between vitiligo and depression. We aimed to investigate the underlying prevalence and risk of depression among patients with vitiligo. A comprehensive search of MEDLINE, Embase and the Cochrane Library was conducted. Cross‐sectional, case–control or cohort studies that assessed the prevalence of depression among patients with vitiligo or the relationship between vitiligo and depression were included. DerSimonian and Laird random‐effects models were utilized to calculate the pooled prevalence and relative risks. Publication bias was evaluated by funnel plots and Egger's tests. Twenty‐five studies with 2708 cases of vitiligo were included. Based on diagnostic codes, the pooled prevalence of depression among patients with vitiligo was 0·253 95% confidence interval (CI) 0·16–0·34; P < 0·001). Using self‐reported questionnaires, the pooled prevalence of depressive symptoms was 0·336 (95% CI 0·25–0·42; P < 0·001). The pooled odds ratio of depression among patients with vitiligo was 5·05 vs. controls (95% CI 2·21–11·51; P < 0·001). Moderate‐to‐high heterogeneity was observed between the studies. Patients with vitiligo were significantly more likely to suffer from depression. Clinical depression or depressive symptoms can be prevalent, with the actual prevalence differing depending on screening instruments or, possibly, geographical regions. Clinicians should actively evaluate patients with vitiligo for signs/symptoms of depression and provide appropriate referrals to manage their psychiatric symptoms accordingly.
What's already known about this topic?
Vitiligo can have profound psychosocial impacts and impair patients’ quality of life.
Studies have suggested a relationship between vitiligo and depression.
What does this study add?
Patients with vitiligo were significantly more likely to suffer from depression than controls.
The pooled prevalence and risk of depression vary depending on screening instruments or, possibly, geographical regions.
Here, we report on the occurrence of a novel perfluoroalkyl ether carboxylic acid, ammonium perfluoro-2-(propoxy)propoxy-1-propanoate (HFPO-TA), in surface water and common carp (Cyprinus carpio) ...collected from the Xiaoqing River and in residents residing near a fluoropolymer production plant in Huantai County, China. Compared with the levels upstream of the Xiaoqing River, HFPO-TA concentrations (5200–68500 ng/L) were approximately 120–1600-times higher downstream after receiving fluoropolymer plant effluent from a tributary. The riverine discharge of HFPO-TA was estimated to be 4.6 t/yr, accounting for 22% of total PFAS discharge. In the wild common carp collected downstream from the point source, HFPO-TA was detected in the blood (median: 1510 ng/mL), liver (587 ng/g ww), and muscle (118 ng/g ww). The log BCFblood of HFPO-TA (2.18) was significantly higher than that of PFOA (1.93). Detectable levels of HFPO-TA were also found in the sera of residents (median: 2.93 ng/mL). This is the first report on the environmental occurrence and bioaccumulation of this novel chemical. Our results indicate an emerging usage of HFPO-TA in the fluoropolymer manufacturing industry and raise concerns about the toxicity and potential health risks of HFPO-TA to aquatic organisms and humans.
Both capsule endoscopy (CE) and angiography have been recommended as first investigation for patients with acute overt obscure gastrointestinal bleeding (OGIB). However, no studies have directly ...compared the two modalities in patients with overt OGIB. We compared the diagnostic yield and long-term outcomes of patients with overt OGIB randomized to CE or angiogram.
Consecutive patients presented with acute melena or hematochezia, but nondiagnostic upper and lower endoscopy, were immediately randomized to receive small-bowel CE or angiography. All patients were monitored for rebleeding and anemia for up to 5 years. Primary end point was the diagnostic yield of the assigned investigation. Secondary end points included rebleeding, further transfusion, readmission for bleeding or anemia, and mortality.
A total of 60 patients with overt OGIB were randomized. The mean follow-up was 48.5 months. The diagnostic yield of immediate CE was significantly higher than angiography (53.3% vs. 20.0%, P = 0.016). The cumulative risk of rebleeding in the angiography and CE group was 33.3% and 16.7%, respectively (P = 0.10, log-rank test). There was no significant difference in the long-term outcomes between the two groups including further transfusion, hospitalization for rebleeding, and mortality.
In patients with overt OGIB, immediate CE has higher diagnostic yield and comparable long-term outcomes when compared with angiography.
Conventional grafting-to approaches to DNA–polymer conjugates are often limited by low reaction yields due to the sterically hindered coupling of a presynthesized polymer to DNA. The grafting-from ...strategy, in contrast, allows one to directly graft polymers from an initiator that is covalently attached to DNA. Herein, we report blue-light-mediated reversible addition–fragmentation chain-transfer (Photo-RAFT) polymerization from two different RAFT agent-terminated DNA sequences using Eosin Y as the photocatalyst in combination with ascorbic acid. Three monomer families (methacrylates, acrylates and acrylamides) were successfully polymerized from DNA employing Photo-RAFT polymerization. We demonstrate that the length of the grown polymer chain can be varied by altering the monomer to DNA-initiator ratio, while the self-assembly features of the DNA strands were maintained. In summary, we describe a convenient, light-mediated approach toward DNA–polymer conjugates via the grafting-from approach.
Ride-sharing with travel time uncertainty Long, Jiancheng; Tan, Weimin; Szeto, W.Y. ...
Transportation research. Part B: methodological,
12/2018, Letnik:
118
Journal Article
Recenzirano
•Propose a ride-sharing problem in road networks with travel time uncertainty.•Introduce the generalized trip cost functions for both driving-alone and ride-sharing trips.•Analyze the mathematical ...properties of the generalized trip cost functions.•Propose a bi-objective ride-sharing matching model.•Demonstrate the importance of considering travel time uncertainty when determining the matches.
Travel time uncertainty has significant effects on travel reliability and travelers’ generalized trip cost. However, travel time uncertainty has not been considered in existing ride-sharing models, leading to an inaccurate estimation of the benefit from ride-sharing and irrational ride-sharing matches. To fill in the gap, this paper proposes a stochastic ride-sharing model, in which travel time is assumed to be stochastic and follow a time-independent general distribution that has a positive lower bound. Due to travel time uncertainty, travelers may not arrive at their destinations on time. Different from the traditional models taking time windows as hard constraints, the proposed ride-sharing system only requires each participant announcing a role and the desired arrival time window. In the model, the generalized trip cost consists of the cost of driving a vehicle, the cost of travel time, and the cost of schedule delay early and late. This study investigates the effect of the unit variable cost of driving, travelers’ values of time (VOTs), and travel time uncertainty on the cost saving of ride-sharing trips compared to driving-alone trips. A bi-objective ride-sharing matching model is proposed to maximize both the total generalized trip cost saving and the number of matches. The proposed ride-sharing model is further extended to consider time-dependent travel time uncertainty, and the Monte Carlo simulation (MCS) method is developed to evaluate the mean generalized trip cost. Finally, numerical examples are provided to illustrate the properties of the two proposed models. The results show that the unit variable cost of driving, travelers’ VOTs, travel time uncertainty, and the selection of the weight in the objective function have significant impacts on the performance of the proposed ride-sharing system with travel time uncertainty. The results also show that a feasible ride-sharing match based on deterministic travel time can become infeasible in a stochastic ride-sharing system. It is therefore important to consider travel time uncertainty when determining the matches.
An isothiocyanate-functionalized tetraphenylethene is synthesized and used as a fluorescent bioprobe for mitochondrion imaging with high specificity and photostability. The covalent conjugation of ...the bioprobe to mitochondrial proteins endows it with high resistance to microenvironmental changes, enabling it for real-time monitoring of mitophagy.
Mind wandering is often characterized by attention oriented away from an external task towards our internal, self-generated thoughts. This universal phenomenon has been linked to numerous disruptive ...functional outcomes, including performance errors and negative affect. Despite its prevalence and impact, studies to date have yet to identify robust behavioral signatures, making unobtrusive, yet reliable detection of mind wandering a difficult but important task for future applications. Here we examined whether electrophysiological measures can be used in machine learning models to accurately predict mind wandering states. We recorded scalp EEG from participants as they performed an auditory target detection task and self-reported whether they were on task or mind wandering. We successfully classified attention states both within (person-dependent) and across (person-independent) individuals using event-related potential (ERP) measures. Non-linear and linear machine learning models detected mind wandering above-chance within subjects: support vector machine (AUC = 0.715) and logistic regression (AUC = 0.635). Importantly, these models also generalized across subjects: support vector machine (AUC = 0.613) and logistic regression (AUC = 0.609), suggesting we can reliably predict a given individual's attention state based on ERP patterns observed in the group. This study is the first to demonstrate that machine learning models can generalize to "never-seen-before" individuals using electrophysiological measures, highlighting their potential for real-time prediction of covert attention states.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
In this randomized trial in patients who had ulcer bleeding while taking aspirin for prevention of vascular disease, clopidogrel was associated with a much higher rate of recurrent bleeding than the ...combination of aspirin and a proton-pump inhibitor (8.6 percent vs. 0.7 percent).
In patients who had ulcer bleeding while taking aspirin for prevention of vascular disease, clopidogrel was associated with a much higher rate of recurrent bleeding than the combination of aspirin and a proton-pump inhibitor.
It is estimated that during the past two decades 50 million Americans have started taking aspirin for the prevention of heart attack and stroke.
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However, aspirin doubles the risk of upper gastrointestinal bleeding even at doses as low as 75 mg daily.
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A history of upper gastrointestinal bleeding from an ulcer is the most important risk factor for subsequent upper gastrointestinal bleeding in patients taking aspirin.
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,
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Up to 15 percent of those taking aspirin who have a history of bleeding from ulcers had recurrent bleeding within one year.
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Proton-pump inhibitors reduce the risk of aspirin-induced ulcer bleeding,
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