Underlying burning resistant mechanisms for titanium alloy

The "titanium fire" as produced during high pressure and friction is the major failure scenario for aero-engines. To alleviate this issue, Ti-V-Cr and Ti-Cu-Al series burn resistant titanium alloys have been developed. However, which burn resistant alloy exhibit better property with reasonable cost needs to be evaluated. This work unveils the burning mechanisms of these alloys and discusses whether burn resistance of Cr and V can be replaced by Cu, on which thorough exploration is lacking. Two representative burn resistant alloys are considered, including Ti14(Ti-13Cu-1Al-0.2Si) and Ti40(Ti-25V-15Cr-0.2Si)alloys. Compared with the commercial non-burn resistant titanium alloy, i.e., TC4(Ti-6Al-4V)alloy, it has been found that both Ti14 and Ti40 alloys form "protective" shields during the burning process. Specifically, for Ti14 alloy, a clear Cu-rich layer is formed at the interface between burning product zone and heat affected zone, which consumes oxygen by producing Cu-O compounds and impedes the reaction with Ti-matrix. This work has established a fundamental understanding of burning resistant mechanisms for titanium alloys. Importantly, it is found that Cu could endow titanium alloys with similar burn resistant capability as that of V or Cr, which opens a cost-effective avenue to design burn resistant titanium alloys.Comment: 6 figure

Percutaneous closure versus surgical repair for ruptured sinus of valsalva aneurysm: A systematic review and meta-analysis

ObjectivesRuptured sinus of Valsalva aneurysm (RSVA) often has an abrupt onset, and can chest pain, acute heart failure, and even sudden death. The effectiveness of different treatment modalities remains controversial. Thus, we completed a meta-analysis to evaluate the efficiency and safety of traditional surgery vs. percutaneous closure (PC) for RSVA.MethodsWe carried out a meta-analysis using PubMed, Embase, Web of Science, Cochrane Library, China National Knowledge Infrastructure (CNKI), WanFang Data, and the China Science and Technology Journal Database. The primary outcome was comparing in-hospital mortality between the two procedures, and the secondary outcome was documenting postoperative residual shunts, postoperative aortic regurgitation, and length of hospital stay in the two groups. Differences were expressed as odds ratios (ORs) with 95% confidence intervals (CIs) to assess the relationships between predefined surgical variables and clinical outcomes. This meta-analysis was conducted using Review Manager software (version 5.3).ResultsThe final qualifying studies included 330 patients from 10 trials (123 in the percutaneous closure group, and 207 in the surgical repair group). When PC was compared to surgical repair, there were no statistically significant differences in in-hospital mortality (overall OR: 0.47, 95%CI 0.05–4.31, P = 0.50). However, percutaneous closure did significantly decrease the average length of hospital stay (OR: −2.13, 95% CI −3.05 to −1.20, P < 0.00001) when compared to surgical repair, but there were no significant between-group differences in the rates of postoperative residual shunts (overall OR: 1.54, 95%CI 0.55–4.34, P = 0.41) or postoperative aortic regurgitation (overall OR: 1.54, 95%CI 0.51–4.68, P = 0.45).ConclusionPC may become a valuable alternative to surgical repair for RSVA

Case report: Surgical repair of congenitally corrected transposition of the great arteries with the guidance of three-dimensional printing

A 10-year-old girl presented with obvious cyanosis, and the saturation of arterial blood oxygen (SpO2) was decreased to 60.5% in the outpatient examination. Computed tomography angiography (CTA) and echocardiography suggested congenitally corrected transposition of the great arteries (ccTGAs), membranous ventricular septal aneurysm (MVSA), atrial septal defect (ASD), severe pulmonary stenosis (PS), and severe tricuspid regurgitation (TR). Due to the complex pathological anatomical structures, the three-dimensional printed model was used for preoperative assessment. After a comprehensive evaluation was completed, the operation was performed by physiological correction under cardiopulmonary bypass, including the resection of MVSA, repair using the bovine pericardial patch for ASD, and linear valvuloplasty of the tricuspid valve. Due to the special anatomical structures of ccTGA, PS was treated by extracardiac pipe technique. After the operation, the patient recovered well, cyanosis disappeared, SpO2 was up to 96%, and the extracardiac pipe was well-functioning without regurgitation or obstruction

Accelerating Emergence of Aerial Swarm

Herein, we present a methodology and framework for exploiting certain interdisciplinary studies that can particularly benefit from integration. In this paper, rigorous derivation of control theory and statistical analysis of simulation results are organically unified for testifying and optimizing the emergence of order in aerial swarming scenarios under free boundary conditions. Each Unmanned Aerial Vehicle (UAV) is regulated by a simplified mathematical model, based on which a distributed flocking protocol is proposed as a feasible solution for aerial swarms. On condition that the initial interaction network is connected, the LaSalle–Krasovskii invariance principle is implemented to verify the effectiveness of the above algorithm. However, most existing results on flocking are far from being engineering applications. A basic challenge is how to present a low-cost energy and time saving solution on account of the limited flight capability of these UAVs and real-time operational requirements. As is well known, energy consumption can be reduced if unnecessary interactions among individuals are eliminated. Therefore, another contribution of this paper is to propose a precise optimization of an existing flocking algorithm for UAVs with respect to interaction requirements. Energy and time measurements, as well as scalability effects, are assessed in terms of statistical significance and strength. The results indicate that the flocking control protocol adopting the minimal interaction is the most promising swarm

Femtosecond second-harmonic generation in periodically poled lithium niobate waveguides written by femtosecond laser pulses

We present in this Letter the second-harmonic generation of femtosecond pulses in double-line-written waveguides fabricated in periodically poled lithium niobate (PPLN) with femtosecond laser pulses. In a 10-mm-long sample, a normalized conversion efficiency of 12.6% W−1 cm−2 has been achieved for 40 fs pump pulses with the wavelengths centered at 1550 nm. Simulation results show that in PPLN waveguides the FWHM of wavelength tuning curve for 40 fs pump pulses is 42 nm, which is 15 times of that for 40 ps pump pulses

Molecular Mechanism Underlying Role of the XBP1s in Cardiovascular Diseases

Spliced X-box binding protein-1 (XBP1s) is a protein that belongs to the cAMP-response element-binding (CREB)/activating transcription factor (ATF) b-ZIP family with a basic-region leucine zipper (bZIP). There is mounting evidence to suggest that XBP1s performs a critical function in a range of different cardiovascular diseases (CVDs), indicating that it is necessary to gain a comprehensive knowledge of the processes involved in XBP1s in various disorders to make progress in research and clinical therapy. In this research, we provide a summary of the functions that XBP1s performs in the onset and advancement of CVDs such as atherosclerosis, hypertension, cardiac hypertrophy, and heart failure. Furthermore, we discuss XBP1s as a novel therapeutic target for CVDs

Immune diversity in lophotrochozoans, with a focus on recognition and effector systems

Lophotrochozoa is one of the most species-rich but immunologically poorly explored phyla. Although lack of acquired response in a narrow sense, lophotrochozoans possess various genetic mechanisms that enhance the diversity and specificity of innate immune system. Here, we review the recent advances of comparative immunology studies in lophotrochozoans with focus on immune recognition and effector systems. Haemocytes and coelomocytes are general important yet understudied player. Comparative genomics studies suggest expansion and functional divergence of lophotrochozoan immune reorganization systems is not as “homogeneous and simple” as we thought including the large-scale expansion and molecular divergence of pattern recognition receptors (PRRs) (TLRs, RLRs, lectins, etc.) and signaling adapters (MyD88s etc.), significant domain recombination of immune receptors (RLR, NLRs, lectins, etc.), extensive somatic recombination of fibrinogenrelated proteins (FREPs) in snails. Furthermore, there are repeatedly identified molecular mechanisms that generate immune effector diversity, including high polymorphism of antimicrobial peptides and proteins (AMPs), reactive oxygen and nitrogen species (RONS) and cytokines. Finally, we argue that the next generation omics tools and the recently emerged genome editing technicism will revolutionize our understanding of innate immune system in a comparative immunology perspective

Streamflow Regime Variations Following Ecological Management on the Loess Plateau, China

The continuous ecological management of the Loess Plateau is known throughout the world for two strategies: the integrated soil conservation project that began in the 1970s, and the “Grain for Green” project that began in the 1990s. Six sub-catchments nested in the Beiluo River basin were selected to investigate streamflow regime variations during the two project periods. The annual streamflow trends and change points were detected using a bootstrap-based Mann-Kendall test and Pettitt test. Annual streamflow (from the 1950s to 2011) exhibited significantly negative trends in five out of six catchments, varying from −0.15 to −0.30 mm/a. During the integrated soil conservation period, the annual streamflow was reduced due to high flow decreases (5% of time exceeded), whereas in the low flows (95%) it increased in all sub-catchments. During the “Grain for Green” period, the annual streamflow decreased due to daily streamflow reductions at four stations. In addition to high flow and low flow decreases at the Wuqi and Liujiahe stations during the “Grain for Green” period, it is significant that the low flows continuously increased. Compared with trends from the forestry area, which includes the Zhangcunyi and Huangling stations, incremental annual streamflow reductions were observed in other sub-catchments, which can be linked to ecological management. This result implies that streamflow can be moderated by appropriate management options, even in semiarid areas. It was concluded that a stable streamflow regime can be achieved in vegetated areas, and streamflow moderation is dependent on ecological management practices

Current studies and future promises of PD-1 signal inhibitors in cervical cancer therapy

PD-1 (Programmed cell death-1) is a receptor that inhibits the activation of T cells and is an important target for cancer immunotherapy. PD-1 expression stays high on antigen-specific T cells that have been stimulated for a long time, making them less responsive to stimuli. Consequently, there has been a recent surge in the number of researchers focusing on how the PD-1 axis delivers inhibitory signals to uncover new therapeutic targets. As an inhibitory signaling mechanism, the PD-1 axis controls immunological responses. Blocking the PD-1 axis has been shown to have long-lasting effects on various cancers, demonstrating the crucial role of PD-1 in blocking anti-tumor immunity. Despite this role, most patients do not respond to PD-1 monotherapy, and some have experienced adverse events. Many challenges remain regarding the PD-1 signaling axis to be addressed. In this review, we outline the most recent research and prospects of PD-1 signal inhibitors to enhance cervical cancer therapy