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The support structure acts as an auxiliary structure for selective laser melting (SLM) part forming. The structural characteristics affect the residual stress distribution of the molded part, necessitating an investigation into its influence on SLM AlSi10Mg alloy. This paper proposes a support structure suitable for processing thin-walled parts based on a combination of numerical simulation and conventional experiments. The experiments are generally consistent with the numerical results, and the study shows that the simulation results can be reliably used to calculate residual stress and strain. The study initiates by comparing the effects of four types of bracing structures on residual stress in various regions of thin-walled parts. A hybrid support structure is obtained by selecting the support structure in different regions. The study thoroughly investigates how the hybrid support structure, with varied support tooth parameters, affects residual stress in different regions of thin-walled parts. Optimal parameters for the hybrid support structure are identified, enhancing its effectiveness in mitigating residual stress. Finally, the milling experiments of the optimal hybrid support structure are carried out, and it is found that the milling force is reduced by about 19% and the flatness is reduced by about 16% compared with other hybrid support structures. [ABSTRACT FROM AUTHOR]

The lightweight design of the hood is crucial for the structural optimization of an entire vehicle. However, traditional high-fidelitybased lightweight methods are time-consuming due to the complex structures of the hood, and the lightweight results heavily rely on engineering experiences. To this end, an improved adaptive marine predator algorithm (AMPA) is proposed to solve this problem. Compared to the original marine predator algorithm (MPA), the proposed AMPA adapts to optimization problems through three enhancements, including chaotic theory-based initialization, a mixed search strategy, and dynamic partitioning of iteration phases. Experimental comparisons of AMPA, MPA, and eight state-of-the-art algorithms are conducted on IEEE CEC2017 benchmark functions. AMPA outperforms the others in both 30- and 50-dimensional experiments. Friedman and Wilcoxon's sign-rank tests further confirm AMPA's superiority and statistical significance. An implicit parametric model of the hood is generated, and the critical design variables are determined through global sensitivity analysis to realize hood lightweight. The stacking method is employed to construct a surrogate meta-model of the hood to accelerate the optimization efficiency of the vehicle hood. Utilizing the meta-model and the proposed AMPA, the hood mass is reduced by 7.43% while all six static and dynamic stiffness metrics are enhanced. The effectiveness of the proposed optimization method is validated through finite element analysis. [ABSTRACT FROM AUTHOR]

Widely distributed in the alpine sandy grassland in east Qinghai-Tibet Plateau (QTP), Kengyilia melanthera is considered as an ideal pioneer grass for the restoration of degraded and desertification grassland in the region. Under the special ecological and climatic conditions in the northwest Sichuan plateau located in east QTP, it is of great significance to optimize the amount of nitrogen fertilizer for the seed production of this species. The impact of nitrogen (N) fertilizer application on seed yield and quality of K. melanthera 'Aba', the only domesticated variety in the Kengyilia genus of Poaceae, was investigated based on two-year field experiments in the northwestern Sichuan plateau. The results showed that with the increase of N fertilizer application, the number of tillers, number of fertile tillers, 1,000-seed weight and seed yield of this species increased likewise. The optimum N fertilizer rate deduced in the present study was 180 kg·hm-2, where the number of fertile tillers 1,000-seed weight and seed yield reached the peak values. Interestingly, the standard germination rate, germination energy, accelerated aging germination rate, dehydrogenase and acid phosphatase activity of seeds were not affected by the increasing the input of N fertilizer. The comprehensive evaluation of membership function showed that the optimal N fertilizer treatment was 180 kg·hm-2 both for 2016 and 2017. This study provided a certain practical suggestion for the improvement of seed production of K. melanthera in the northwest Sichuan plateau. [ABSTRACT FROM AUTHOR]

The immunosuppressive and hypoxic tumor microenvironment (TME) remains a major obstacle to impede cancer immunotherapy. Here, we showed that elevated levels of Delta-like 1 (DLL1) in the breast and lung TME induced long-term tumor vascular normalization to alleviate tumor hypoxia and promoted the accumulation of interferon? (IFN-γ)-expressing CD8+ T cells and the polarization of M1-like macrophages. Moreover, increased DLL1 levels in the TME sensitized anti-cytotoxic T lymphocyte-associated protein 4 (anti-CTLA4) treatment in its resistant tumors, resulting in tumor regression and prolonged survival. Mechanically, in vivo depletion of CD8+ T cells or host IFN-γ deficiency reversed tumor growth inhibition and abrogated DLL1-induced tumor vascular normalization without affecting DLL1-mediated macrophage polarization. Together, these results demonstrate that elevated DLL1 levels in the TME promote durable tumor vascular normalization in a CD8+ T cell- and IFN-γ-dependent manner and potentiate anti-CTLA4 therapy. Our findings unveil DLL1 as a potential target to persistently normalize the TME to facilitate cancer immunotherapy. [ABSTRACT FROM AUTHOR]

Potassium-ion batteries are a promising alternative to lithium-ion batteries. However, it is challenging to achieve fast charging/discharging and long cycle life with the current electrode materials because of the sluggish potassiation kinetics. Here we report a soft carbon anode, namely highly nitrogen-doped carbon nanofibers, with superior rate capability and cyclability. The anode delivers reversible capacities of 248 mAh g–1at 25 mA g–1 and 101 mAh g–1 at 20 A g–1, and retains 146 mAh g–1 at 2 A g–1 after 4000 cycles. Surface-dominated K-storage is verified by quantitative kinetics analysis and theoretical investigation. A full cell coupling the anode and Prussian blue cathode delivers a reversible capacity of 195 mAh g–1 at 0.2 A g–1. Considering the cost-effectiveness and material sustainability, our work may shed some light on searching for K-storage materials with high performance. [ABSTRACT FROM AUTHOR]

Indigofera pseudotinctoria Mats is an agronomically and economically important perennial legume shrub with a high forage yield, protein content and strong adaptability, which is subject to natural habitat fragmentation and serious human disturbance. Until now, our knowledge of the genetic relationships and intraspecific genetic diversity for its wild collections is still poor, especially at small spatial scales. Here amplified fragment length polymorphism (AFLP) technology was employed for analysis of genetic diversity, differentiation, and structure of 364 genotypes of I. pseudotinctoria from 15 natural locations in Wushan Montain, a highly structured mountain with typical karst landforms in Southwest China. We also tested whether eco-climate factors has affected genetic structure by correlating genetic diversity with habitat features. A total of 515 distinctly scoreable bands were generated, and 324 of them were polymorphic. The polymorphic information content (PIC) ranged from 0.694 to 0.890 with an average of 0.789 per primer pair. On species level, Nei's gene diversity (Hj), the Bayesian genetic diversity index (HB) and the Shannon information index (I) were 0.2465, 0.2363 and 0.3772, respectively. The high differentiation among all sampling sites was detected (FST = 0.2217, GST = 0.1746, G'ST = 0.2060, өB = 0.1844), and instead, gene flow among accessions (Nm = 1.1819) was restricted. The population genetic structure resolved by the UPGMA tree, principal coordinate analysis, and Bayesian-based cluster analyses irrefutably grouped all accessions into two distinct clusters, i.e., lowland and highland groups. The population genetic structure resolved by the UPGMA tree, principal coordinate analysis, and Bayesian-based cluster analyses irrefutably grouped all accessions into two distinct clusters, i.e., lowland and highland groups. This structure pattern may indicate joint effects by the neutral evolution and natural selection. Restricted Nm was observed across all accessions, and genetic barriers were detected between adjacent accessions due to specifically geographical landform. [ABSTRACT FROM AUTHOR]

Glaciation and mountain orogeny have generated new ecologic opportunities for plants, favoring an increase in the speciation rate. Moreover, they also act as corridors or barriers for plant lineages and populations. High genetic diversity ensures that species are able to survive and adapt. Gene flow is one of the most important determinants of the genetic diversity and structure of out-crossed species, and it is easily affected by biotic and abiotic factors. The aim of this study was to characterize the genetic diversity and structure of an alpine species, Festuca ovina L., in Xinjiang, China. A total of 100 individuals from 10 populations were analyzed using six amplified fragment length polymorphism (AFLP) primer pairs. A total of 583 clear bands were generated, of which 392 were polymorphic; thus, the percentage of polymorphic bands (PPB) was 67.24%. The total and average genetic diversities were 0.2722 and 0.2006 (0.1686-0.2225), respectively. The unweighted group method with arithmetic mean (UPGMA) tree, principal coordinates analysis (PCoA) and Structure analyses revealed that these populations or individuals could be clustered into two groups. The analysis of molecular variance analysis (AMOVA) suggested that most of the genetic variance existed within a population, and the genetic differentiation (Fst) among populations was 20.71%. The Shannon differentiation coefficient (G'st) among populations was 0.2350. Limited gene flow (Nm = 0.9571) was detected across all sampling sites. The Fst and Nm presented at different levels under the genetic barriers due to fragmentation. The population genetic diversity was significant relative to environmental factors such as temperature, altitude and precipitation. [ABSTRACT FROM AUTHOR]

Postoperative analgesia remains a challenge for orthopedic surgeons. The aim of this meta-analysis is to compare the efficacy of epidural analgesia (EA) and intravenous patientcontrolled analgesia (IV-PCA) following major spine surgery. We searched electronic databases, including the PubMed, EMBASE, Ovid and Cochrane databases, for randomized controlled trials (RCTs) published before June 2016. The quality of the included trials was assessed using the Cochrane risk-of-bias tool. Random effects models were used to estimate the standardized mean differences (SMDs) and relative risks (RRs), with the corresponding 95% confidence intervals (CI). Subgroup analyses stratified by the type of epidural-infused medication and epidural delivery were also performed. A total of 17 trials matched the inclusion criteria and were chosen for the following meta-analysis. Overall, EA provided significantly superior analgesia, higher patient satisfaction and decreased overall opioid consumption compared with IV-PCA following major spine surgery. Additionally, no differences were found in the side effects associated with these two methods of analgesia. Egger's and Begg's tests showed no significant publication bias. We suggest that EA is superior to IV-PCA for pain management after major spine surgery. More large-scale, high-quality trials are needed to verify these findings. [ABSTRACT FROM AUTHOR]

Purpose: Several publications have investigated the association between the Cyclin D1 G to A substitution at nucleotide 870 (CCND1 G870A) polymorphism and squamous cell carcinoma (SCC) of the upper aerodigestive tract (UADT), but their conclusions still remain controversial. We conducted a meta-analysis to precisely evaluate this association. Patients and methods: We electronically searched the Chinese National Knowledge Infrastructure, PubMed, and Embase (up to January 2015) databases for case-control studies on the association between the CCND1 G870A polymorphism and SCC of the UADT, and 23 studies were included in total. Results: The meta-analysis results showed that there was a significant association between the CCND1 G870A polymorphism and the risk of SCC of the UADT (AA vs GG: odds ratio [OR] =1.33, 95% confidence interval [CI] =1.01-1.74, P,0.001 for heterogeneity; GA/AA vs GG: OR =1.24, 95% CI =1.01-1.51, P,0.001 for heterogeneity; AA vs GA/GG: OR =1.16, 95% CI =0.97-1.39, P,0.001 for heterogeneity; allele A vs allele G: OR =1.14, 95% CI =1.00-1.30, P,0.001 for heterogeneity; GA vs GG: OR =1.18, 95% CI =0.98-1.42, P,0.001 for heterogeneity). However, when analyzing prognosis, allele G was a potential risk factor for poor tumor differentiation (AA vs GA/GG: OR =2.60, 95% CI =1.15-5.86, P=0.836 for heterogeneity) and reduced disease-free intervals (OR =2.08, 95% CI =1.17-3.69, P=0.134 for heterogeneity). In the subgroup analysis, the cancer susceptibility of Asian groups, populationbased control groups, nasopharyngeal cancer groups, and esophageal SCC groups were more likely to be affected by the CCND1 G870A polymorphism. No significant publication bias was found in our analysis (P=0.961 for Egger's test and P=0.245 for Begg's test). Conclusion: The results of the present meta-analysis suggest that the variant CCND1 870A allele might confer an elevated risk of SCC of the UADT, particularly among Asians and individuals who have esophageal or nasopharyngeal cancers. Moreover, the CCND1 870A allele might also confer better tumor differentiation grades and longer disease-free intervals. [ABSTRACT FROM AUTHOR]

Background: Infection with pathogenic Leptospira species causes serious systemic inflammation in patients. Although a few leptospiral proinflammatory molecules have been identified, Leptospira likely encodes other unidentified strong inflammation stimulators. The pathogenic L. interrogans genome encodes numerous putative hemolysin genes. Since hemolysins from other bacteria can cause inflammatory reactions, we hypothesized that leptospiral hemolysins may function as proinflammatory stimulators that contribute to the strong inflammation associated with Leptospira infection. Methodology/Principal Findings: We first used cytokine protein microarrays for systematic analysis of serum cytokine profiles in leptospirosis patients and leptospire-infected mice. We found that IL-1β, IL-6 and TNF-α were the main proinflammatory cytokines in the sera of both the patients and the mice. We then analyzed eight putative hemolysins in L. interrogans strain Lai. The results showed that five of them, Sph1, Sph2, Sph3, HlpA and TlyA were secreted and had hemolytic activity. More importantly, these five hemolysins induced the strong production of IL-1β, IL-6 and TNF-α in human and mouse macrophages (although a bit lower in the latter). Furthermore, blockade of TLR2 or TLR4 with either antibodies or inhibitors of the NF-κB or JNK signaling pathways significantly reduced the production of hemolysin-induced IL-1β, IL-6 and TNF-α. Macrophages isolated from TLR2-, TLR4-or double TLR2-and 4- deficient mice also confirmed that the leptospiral hemolysins that induce proinflammatory cytokines are both TLR2-and TLR4-dependent. Conclusions/Significance: Our findings demonstrate that L. interrogans secretes many hemolysins that function as powerful inducers of proinflammatory cytokines through both TLR2-and TLR4-dependent JNK and NF-κB pathways. [ABSTRACT FROM AUTHOR]