•The research on residual stress arising in additive manufacturing by SLM are reviewed.•The advantages and disadvantages of mainstream research methods are analyzed.•New concepts on controlling the ...residual stress in alloy parts by SLM are proposed.
The undesirable residual stress accumulated in the parts during the melting and solidification of the metal powder layer by layer retards the further application of the selective laser melting (SLM) process. This paper focuses on reviewing the recent illuminating achievements about physical modeling, experimental characterizing, and active adjusting of the residual stress in the parts fabricated by SLM. The advantages and disadvantages of the mainstream and emerging models or approaches are further analyzed. Based on the status and prospect of the relative techniques, a series of conceptual methods are discussed on mitigating residual stress to make some practical inspiration for developing a systematical residual stress balancing technique for SLM.
The objective of this study is to design the hull-mounted sonar dome of a ship. The goal is to reduce the ship total resistance and improve the flow field around the sonar dome for the ship design ...speed. OpenFOAM 6 was applied to analyze the viscous flow around the ship bow and then optimize the sonar dome geometry. The length, width and depth of the original geometry were maintained. Only the local geometry was fine-tuned considering the back slope and front tip by using Rhinoceros 6. The verification and validation was performed for the original hull form against towing tank resistance data. The grid independence was checked for the optimal design in different design stages. To ensure less influence on the interior equipment installation and to be able to re-use the non-steel dome part, the best resistance reduction is almost 2%. With a larger allowance of shape deformation, the maximal reduction could reach slightly higher than 3%. The flow field is improved for smaller flow separation and vortex, and less fluid nose in sonar detection is expected. The main reason of the resistance reduction is the decrease of the pressure component. In conclusion, a sonar dome design procedure is proposed, and an optimal geometry is suggested.
Abstract Ingestion of specific probiotics, namely “psychobiotics”, produces psychotropic effects on behavior and affects the hypothalamic–pituitary–adrenal axis and neurochemicals in the brain. We ...examined the psychotropic effects of a potential psychobiotic bacterium, Lactobacillus plantarum strain PS128 (PS128), on mice subjected to early life stress (ELS) and on naïve adult mice. Behavioral tests revealed that chronic ingestion of PS128 increased the locomotor activities in both ELS and naïve adult mice in the open field test. In the elevated plus maze, PS128 significantly reduced the anxiety-like behaviors in naïve adult mice but not in the ELS mice; whereas the depression-like behaviors were reduced in ELS mice but not in naïve mice in forced swimming test and sucrose preference test. PS128 administration also reduced ELS-induced elevation of serum corticosterone under both basal and stressed states but had no effect on naïve mice. In addition, PS128 reduced inflammatory cytokine levels and increased anti-inflammatory cytokine level in the serum of ELS mice. Furthermore, the dopamine level in the prefrontal cortex (PFC) was significantly increased in PS128 treated ELS and naïve adult mice whereas serotonin (5-HT) level was increased only in the naïve adult mice. These results suggest that chronic ingestion of PS128 could ameliorate anxiety- and depression-like behaviors and modulate neurochemicals related to affective disorders. Thus PS128 shows psychotropic properties and has great potential for improving stress-related symptoms.
Pangolins are endangered animals in urgent need of protection. Identifying and cataloguing the viruses carried by pangolins is a logical approach to evaluate the range of potential pathogens and help ...with conservation. This study provides insight into viral communities of Malayan Pangolins (
) as well as the molecular epidemiology of dominant pathogenic viruses between Malayan Pangolin and other hosts. A total of 62,508
assembled contigs were constructed, and a BLAST search revealed 3600 ones (≥300 nt) were related to viral sequences, of which 68 contigs had a high level of sequence similarity to known viruses, while dominant viruses were the Sendai virus and Coronavirus. This is the first report on the viral diversity of pangolins, expanding our understanding of the virome in endangered species, and providing insight into the overall diversity of viruses that may be capable of directly or indirectly crossing over into other mammals.
Indoxyl sulfate (IS) and p-cresyl sulfate (PCS) are protein-bound uremic toxins that increase in the sera of patients with chronic kidney disease (CKD), and are not effectively removed by dialysis. ...The purpose of this meta-analysis was to investigate the relationships of PCS and IS with cardiovascular events and all-cause mortality in patients with CKD stage 3 and above.
Medline, Cochrane, and EMBASE databases were searched until January 1, 2014 with combinations of the following keywords: chronic renal failure, end-stage kidney disease, uremic toxin, uremic retention, indoxyl sulfate, p-cresyl sulfate. Inclusion criteria were: 1) Patients with stage 1 to 5 CKD; 2) Prospective study; 3) Randomized controlled trial; 4) English language publication. The associations between serum levels of PCS and IS and the risks of all-cause mortality and cardiovascular events were the primary outcome measures. Of 155 articles initially identified, 10 prospective and one cross-sectional study with a total 1,572 patients were included. Free PCS was significantly associated with all-cause mortality among patients with chronic renal failure (pooled OR = 1.16, 95% CI = 1.03 to 1.30, P = 0.013). An elevated free IS level was also significantly associated with increased risk of all-cause mortality (pooled OR = 1.10, 95% CI = 1.03 to 1.17, P = 0.003). An elevated free PCS level was significantly associated with an increased risk of cardiovascular events among patients with chronic renal failure (pooled OR = 1.28, 95% CI = 1.10 to 1.50, P = 0.002), while free IS was not significantly associated with risk of cardiovascular events (pooled OR = 1.05, 95% CI = 0.98 to 1.13, P = 0.196).
Elevated levels of PCS and IS are associated with increased mortality in patients with CKD, while PCS, but not IS, is associated with an increased risk of cardiovascular events.
Lung cancer in East Asia is characterized by a high percentage of never-smokers, early onset and predominant EGFR mutations. To illuminate the molecular phenotype of this demographically distinct ...disease, we performed a deep comprehensive proteogenomic study on a prospectively collected cohort in Taiwan, representing early stage, predominantly female, non-smoking lung adenocarcinoma. Integrated genomic, proteomic, and phosphoproteomic analysis delineated the demographically distinct molecular attributes and hallmarks of tumor progression. Mutational signature analysis revealed age- and gender-related mutagenesis mechanisms, characterized by high prevalence of APOBEC mutational signature in younger females and over-representation of environmental carcinogen-like mutational signatures in older females. A proteomics-informed classification distinguished the clinical characteristics of early stage patients with EGFR mutations. Furthermore, integrated protein network analysis revealed the cellular remodeling underpinning clinical trajectories and nominated candidate biomarkers for patient stratification and therapeutic intervention. This multi-omic molecular architecture may help develop strategies for management of early stage never-smoker lung adenocarcinoma.
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•First deep proteogenomic landscape of non-smoking lung adenocarcinoma in East Asia•Identified age, sex-related endogenous, and environmental carcinogen mutagenic processes•Proteome-informed classification distinguished clinical features within early stages•Protein networks identified tumorigenesis hallmarks, biomarkers, and druggable targets
Deep proteogenomic landscape of early stage lung adenocarcinoma in a cohort of mostly non-smokers reveals unique drivers and biomarkers, as well as gender-associated mutagenesis.
DNA-Based Nanopore Sensing Liu, Lei; Wu, Hai-Chen
Angewandte Chemie (International ed.),
December 5, 2016, Volume:
55, Issue:
49
Journal Article
Peer reviewed
Nanopore sensing is an attractive, label‐free approach that can measure single molecules. Although initially proposed for rapid and low‐cost DNA sequencing, nanopore sensors have been successfully ...employed in the detection of a wide variety of substrates. Early successes were mostly achieved based on two main strategies by 1) creating sensing elements inside the nanopore through protein mutation and chemical modification or 2) using molecular adapters to enhance analyte recognition. Over the past five years, DNA molecules started to be used as probes for sensing rather than substrates for sequencing. In this Minireview, we highlight the recent research efforts of nanopore sensing based on DNA‐mediated characteristic current events. As nanopore sensing is becoming increasingly important in biochemical and biophysical studies, DNA‐based sensing may find wider applications in investigating DNA‐involving biological processes.
DNA–analyte interactions: Conformational changes of rationally designed DNA probes in nanopores caused by the DNA–analyte interactions may induce distinct current changes during the DNA translocation process. The current signatures can be used to not only ascertain the existence of the analytes but also quantify their concentrations.
To investigate the effectiveness of a school-based program promoting outdoor activities in Taiwan for myopia prevention and to identify protective light intensities.
Multi-area, cluster-randomized ...intervention controlled trial.
A total 693 grade 1 schoolchildren in 16 schools participated. Two hundred sixty-seven schoolchildren were in the intervention group and 426 were in the control group.
Initially, 24 schools were randomized into the intervention and control groups, but 5 and 3 schools in the intervention and control groups, respectively, withdrew before enrollment. A school-based Recess Outside Classroom Trial was implemented in the intervention group, in which schoolchildren were encouraged to go outdoors for up to 11 hours weekly. Data collection included eye examinations, cycloplegic refraction, noncontact axial length measurements, light meter recorders, diary logs, and questionnaires.
Change in spherical equivalent and axial length after 1 year and the intensity and duration of outdoor light exposures.
The intervention group showed significantly less myopic shift and axial elongation compared with the control group (0.35 diopter D vs. 0.47 D; 0.28 vs. 0.33 mm; P = 0.002 and P = 0.003) and a 54% lower risk of rapid myopia progression (odds ratio, 0.46; 95% confidence interval CI, 0.28-0.77; P = 0.003). The myopic protective effects were significant in both nonmyopic and myopic children compared with controls. Regarding spending outdoor time of at least 11 hours weekly with exposure to 1000 lux or more of light, the intervention group had significantly more participants compared with the control group (49.79% vs. 22.73%; P < 0.001). Schoolchildren with longer outdoor time in school (≥200 minutes) showed significantly less myopic shift (measured by light meters; ≥1000 lux: 0.14 D; 95% CI, 0.02-0.27; P = 0.02; ≥3000 lux: 0.16 D; 95% CI, 0.002-0.32; P = 0.048).
The school-based outdoor promotion program effectively reduced the myopia change in both nonmyopic and myopic children. Outdoor activities with strong sunlight exposure may not be necessary for myopia prevention. Relatively lower outdoor light intensity activity with longer time outdoors, such as in hallways or under trees, also can be considered.
The quasinormal frequencies of gravitational perturbation around some well-known regular black holes were investigated in this work. We consider complete perturbations of the energy-momentum tensor ...of electromagnetic part for non-linear electrodynamics and gravitational field. By using the WKB approximation and the asymptotic iteration method, we make a detailed analysis of the gravitational QNM frequencies by varying the characteristic parameters of the gravitational perturbation and the spacetime charge parameters of the regular black holes. It is found that the imaginary part of quasinormal modes as a function of the charge parameter has different monotonic behaviors for different black hole spacetimes. Moreover, the asymptotic expressions of gravitational QNMs for
l
≫
1
are obtained by using the eikonal limit method. We demonstrate that the gravitational perturbation is stable in all these spacetimes.
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