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Abstract ADGRF5 (GPR116) has been identified as a facilitator of breast cancer cell migration and metastasis, yet the underlying mechanisms remain largely elusive. Our current study reveals that the absence of ADGRF5 in breast cancer cells impairs extracellular matrix (ECM)-associated cell motility and impedes in vivo tumor growth. This correlates with heightened expression of matrix metalloproteinase 8 (MMP8), a well-characterized antitumorigenic MMP, and a shift in the polarization of tumor-associated neutrophils (TANs) towards the antitumor N1 phenotype in the tumor microenvironment (TME). Mechanistically, ADGRF5 inhibits ERK1/2 activity by enhancing RhoA activation, leading to decreased phosphorylation of C/EBPβ at Thr235, hindering its nuclear translocation and subsequent activation. Crucially, two C/EBPβ binding motifs essential for MMP8 transcription are identified within its promoter region. Consequently, ADGRF5 silencing fosters MMP8 expression and CXCL8 secretion, attracting increased infiltration of TANs; simultaneously, MMP8 plays a role in decorin cleavage, which leads to trapped-inactivation of TGF-β in the TME, thereby polarizing TANs towards the antitumor N1 neutrophil phenotype and mitigating TGF-β-enhanced cell motility in breast cancer. Our findings reveal a novel connection between ADGRF5, an adhesion G protein-coupled receptor, and the orchestration of the TME, which dictates malignancy progression. Overall, the data underscore ADGRF5 as a promising therapeutic target for breast cancer intervention.

This paper focuses on the dynamic compaction experimental investigation of ADC12 alloy powder using laser impact, leveraging the high strain rate and controllable precision of pulsed lasers. The effects of varying laser energy (Em) and impactor thickness on the relative density, microstructure, and microhardness of the ADC12 alloy powder billets were examined. Utilizing 2D multi-particle finite element simulation (2D MPFEM), the densification mechanism of these billets was analysed with the help of coordination numbers. The simulation also provided insights into the particle velocity, equivalent plastic strain, and adiabatic temperature increase during compaction. Key findings include that a relative densification of up to 97.27% in the billets is achievable when the laser energy reaches 6J. Notably, a decrease in impactor thickness at constant laser energy leads to a more uniform microstructure and microhardness in the billet. Simulations with the 2D MPFEM demonstrate that thinner impactors allow billets to absorb more energy, thereby increasing particle velocity and plastic strain. This enhances both the relative density and mechanical properties of the billets. The simulation explores the stress distribution during compaction and captures the adiabatic temperature rise on the surface of the pressed billet that occurs in the transient, which is consistent with experimental revelations that heat softens or even locally melts the particles to produce sintering. This study offers new insights into the formation process of these billets from a microstructural standpoint, elucidating the relationship between processing conditions and the resulting material properties.

Difficult-to-form materials and complex mold characteristics have an important effect on the fittability and mechanical properties of microforming components. This study focuses on the fittability and mechanical properties of laser shock liquid warm microforming based on AZ31B magnesium alloy foils and a complex microcamera shell die. The characteristics of formed parts under varying temperatures and laser energies were discussed. Single-pulse and double-pulse forming experiments were conducted and compared. At 140 °C and 1260 mJ, double-pulse forming achieved a maximum depth of 184.5 μm, demonstrating near-perfect workpiece conformity to the die. In contrast, single-pulse forming did not achieve such results. This implies that double-pulse forming notably improves the fittability of workpieces and effectively mitigates springback. Finite element simulations corroborate the experimental findings. Moreover, simulation elucidates phenomena observed during experiments, including springback and crack formation. Additionally, the study delves into the microhardness, thickness distribution, and surface roughness of the formed parts. The results indicate that double-pulse forming yields workpieces with superior microhardness, reduced roughness, and a more uniform thickness distribution. Microstructural analysis reveals that grain refinement and substantial occurrence of twinning in the double-pulse forming process are the primary factors contributing to enhanced plasticity. The study also conducts a failure analysis of formed parts at room temperature, revealing the presence of numerous river patterns and cleavage planes, indicative of brittle fracture. Conversely, warm forming avoids fracture failure.

The Seriphidium transiliense desert pasture is an important spring-autumn pasture in northern Xinjiang, China, and has been subjected to grazing by livestock at different intensities, thus resulting in widespread deterioration of its biodiversity and ecosystem services. To understand the response mechanism of stoichiometric characteristics of desert vegetation to grazing, the leaf carbon (C), nitrogen (N), phosphorus (P) and C:N:P ratios of S. transiliense were studied under different grazing intensities. The results show that the control S. transiliense leaf C, N and P contents and C:N, C:P and N:P ratios were 458.79 ± 53.5 g/kg, 20.6 ± 7.18 g/kg, 2.83 ± 1.24 g/kg, 25.69 ± 11.08, 190.28 ± 75.65 and 8.21 ± 4.01, respectively. The differences in these characteristics varied with grazing intensity in accordance with sampling time, so both factors need to be considered comprehensively. General linear model (GLM) analysis indicated that grazing intensity had a strong main effect on S. transiliense leaf C, N, and P content, C:N ratio and N:P ratio. As grazing intensity increased, the leaf N content and N:P ratio increased (P < 0.01), and the C:N ratio decreased (P < 0.01). N content was the limiting factor for the growth of S. transiliense, but the grazing intensity, sampling year and growth season each affected the degree of N limitation. Our findings suggest that the remaining moderate stocking rate was essential for sustaining desert stabilisation in Xinjiang, and although S. transiliense could adapt its nutrient content and leaf stoichiometry to the grazing intensity, N was always the limiting element for the growth of S. transiliense.

AbstractBackground Phosphatidylinositol 3-kinase (PI3K) and protein kinase B (AKT) are involved in the clearance of Mycobacterium tuberculosis (MTB) by macrophages.Aim This study aimed to investigate the effects of polymorphisms in the PI3K/AKT genes and the gene-smoking interaction on susceptibility to TB.Methods This case-control study used stratified sampling to randomly select 503 TB patients and 494 control subjects. Logistic regression analysis was used to determine the association between the polymorphisms and TB. Simultaneously, the marginal structure linear dominance model was used to estimate the gene-smoking interaction.Results Genotypes GA (OR 1.562), AA (OR 2.282), and GA + AA (OR 1.650) at rs3730089 of the PI3KR1 gene were significantly associated with the risk to develop TB. Genotypes AG (OR 1.460), GG (OR 2.785), and AG + GG (OR 1.622) at rs1130233 of the AKT1 gene were significantly associated with the risk to develop TB. In addition, the relative excess risk of interaction (RERI) between rs3730089 and smoking was 0.9608 (95% CI: 0.5959, 1.3256, p

Chimeric antigen receptor T cells (CAR T) targeting CD7 for T-cell acute lymphoblastic leukemia/lymphoma (T-ALL/LBL) showed promising efficacy and safety in some clinical trials. However, most of them were bridged with allogeneic hematopoietic stem cell transplantation (allo-HSCT). We described successful treatment with preventive donor-derived anti-CD7 CAR-T therapy in a case of refractory T lymphoblastic lymphoma following allo-HSCT, who could not receive autologous anti-CD7 CAR-T products due to the low-quality of T lymphocytes. To date, the patient’s complete remission has persisted for 20 months after HSCT.

Laser impact dynamic compaction experiments and 2D multi-particle finite element method (MPFEM) simulations were carried out on aluminum–copper (Al–Cu) binary-based composite powders. Al–Cu compacts with densities of about 95% were successfully prepared at the maximum laser energy of 1.8 J. Research trends indicate that higher power lasers could nearly achieve the theoretical densities. Analysis of the influence laws of laser energy and copper powder mass fraction on the densities of Al–Cu compacts was carried out, and the effects of microstructure and microhardness of Al–Cu compacts on their mechanical properties were investigated, as well as the stresses and velocities in the dynamic compaction process of Al–Cu composite powders were analyzed. The results showed that the relative densities of composite powder compacts of Al-5 wt%Cu gradually exceeded those of Al-10 wt%Cu and Al-15 wt%Cu with the increase of laser energy. In laser impact dynamic compaction the mechanism of inter-particle joining was solid-state press-welding, and the increase in the hardness of the Al–Cu compacts could be attributed to the inherent hardness of the hard particles. The upper particles have a localized maximum velocity of more than 300 m/s, which met the explosion welding velocity, thus localized cold welding occurred and contributed to the inter-particle connection.

Background: Hyaluronic acid (HA), the main component of the extracellular matrix, has the ability to promote tissue repair and regulate inflammation. It is used in otolaryngology as an adjuvant treatment to alleviate postoperative nasal symptoms. However, there is currently insufficient evidence demonstrating the therapeutic efficacy of HA for patients with nasal inflammatory diseases (NIDs). Therefore, this study aimed to evaluate the efficacy and safety of topical HA in the treatment of NID patients without receiving surgery.Methods: In this meta-analysis, comprehensive searches were conducted in PubMed, Embase, the Cochrane Central Register of Controlled Trials, and Web of Science. Keywords searched included “hyaluronic acid,” “sinusitis,” “allergic rhinitis,” “rhinitis,” and “randomized controlled trials (RCTs).” The Cochrane Collaboration’s “Risk of Bias Assessment” tool was used to assess the quality of the included trials, and the meta-analysis was performed using the RevMan 5.3 and STATA 15 statistical software.Results: A total of 11 articles and 825 participants were enrolled. For the primary outcomes, the pooled results revealed that HA significantly improves nasal obstruction (SMD, −0.53; 95% CI, −0.92 to −0.14; p = 0.008; and I2 = 79%) and rhinorrhea (SMD, −0.71; 95% CI, −1.27 to −0.15; p = 0.01; and I2 = 90%) in patients with NIDs. As for the secondary outcomes, the pooled results demonstrated that when compared with the control group, HA could significantly improve nasal endoscopic scores (p < 0.05), rhinitis scores (p < 0.05), rhinomanometry (p < 0.05), nasal neutrophils (p < 0.05), and mucociliary clearance (p < 0.05). However, no significant differences were observed between the two groups regarding nasal itching, sneezing, hyposmia, quality-of-life scores, and nasal eosinophils. For the risk of bias, 54.5% and 45.5% of trials had a low risk of bias in the randomization process and deviation of the intended intervention, respectively.Conclusion: In the present study, the results reveal that HA might ameliorate symptoms of patients with NIDs. However, more clinical trials with larger participant cohorts are required to confirm this result.Systematic review registration number:clinicaltrials.gov, identifier CRD42023414539.

Background. Antihypertensive therapy is crucial for preventing stroke in hypertensive patients. However, the efficacy of antihypertensive therapy varies across individuals, partially due to therapy-related genetic variations among individuals. We investigated the association of antihypertensive drug-related gene polymorphism with stroke in patients with hypertension. Methods. Demographic information, medication, and outcome data were obtained from a hypertensive patient management system, and a PCR fluorescence probe technique was used to detect 7 gene polymorphic loci (CYP2D6∗10, ADRB1, CYP2C9∗3, AGTR1, ACE, CYP3A5∗3, and NPPA), and these loci were compared between patients with and without stroke. Logistic regression was performed to analyze the association of these genetic variations with stroke risk in hypertensive patients while controlling for potential factors. Results. The prevalence of stroke in the hypertensive population in Changsha County of Hunan Province was 2.75%. The mutation frequencies of ADRB1 (1165G > C), CYP2D6∗10, CYP2C9∗3, AGTR1 (1166A > C), ACE (I/D), NPPA (2238T > C), and CYP3A5∗3 were 74.43%, 57.23%, 4.26%, 5.71%, 31.62%, 1.17%, and 69.58%, respectively. Univariate analysis revealed that ADRB1 polymorphism was associated with stroke (χ2 = 8.659, P C), ACE (I/D), CYP3A5∗3, and NPPA (2238T > C) polymorphisms and stroke. Conclusions. ADRB1 (1165G > C) gene polymorphism is associated with the risk of stroke in Chinese hypertensive patients. The CC genotype is correlated with a higher risk of stroke than the GC + GG genotype.

Approximate nearest neighbor (ANN) search has become an essential paradigm for large-scale image retrieval. Conventional ANN search requires the categories of query images to been seen in the training set. However, facing the rapid evolution of newly-emerging concepts on the web, it is too expensive to retrain the model via collecting labeled data with the new (unseen) concepts. Existing zero-shot hashing methods choose the semantic space or intermediate space as the embedding space, which ignore the inconsistency of visual space and semantic space and suffer from the hubness problem on the zero-shot image retrieval task. In this paper, we present an novel deep quantization network with visual-semantic alignment for efficient zero-shot image retrieval. Specifically, we adopt a multi-task architecture that is capable of $ 1) $ learning discriminative and polymeric image representations for facilitating the visual-semantic alignment; $ 2) $ learning discriminative semantic embeddings for knowledge transfer; and $ 3) $ learning compact binary codes for aligning the visual space and the semantic space. We compare the proposed method with several state-of-the-art methods on several benchmark datasets, and the experimental results validate the superiority of the proposed method.

Abstract Background Atherosclerosis and thrombosis play important roles in the pathophysiology of acute coronary syndrome, with platelet activation and inflammation as the key and initiative factors. Recently mean platelet volume-to-lymphocyte ratio (MPVLR) and monocyte to high-density lipoprotein cholesterol ratio (MHR) have emerged as new prognostic indicators of cardiovascular diseases. However, the predicting effect of the combination of MPVLR and MHR in myocardial infarction has not been reported. Objective The aim of this study was to investigate the usefulness of combination of MPVLR and MHR in predicting patients with AMI. Methods 375 patients who had chest pain or stuffiness were retrospectively enrolled in this study. According to the results of coronary angiography and cardiac troponin, patients were divided into AMI group (n = 284) and control group (n = 91). MPVLR, MHR, Gensini score and Grace score were calculated. Results MPVLR and MHR were significantly higher in AMI group than that in control group (6.47 (4.70–9.58) VS 4.88 (3.82–6.44), 13.56 (8.44–19.01) VS 9.14 (7.00–10.86), P

Nickel powders of nominal sizes (i.e., 50 nm, 300 nm, and 2 μm) were pre-coated on copper substrates and then subjected to laser shock processing (LSP) for producing nickel coating. The shockwave consolidation behavior, microstructure, and bonding performance were investigated as a function of particle size. Results indicated that nano-coating had better surface quality, decreased microstructural defects (pores and cracks), and higher bonding strength (approximately twice the hardness value) than its micro-counterpart. Microstructure analysis revealed that nano/submicron particles were consolidated by a mixed solid-liquid sintering behavior, whereas micron particles were consolidated only by solid-state sintering under laser shock. A mixed microstructure of nanocoating was obtained, consisting of solid-state atomic bonds between solid-state sintered particles and amorphous phases between liquid-phase sintered particles. After LSP, the cold shock characteristics of LSP could not only reduce the overall grain growth and oxidation of nano coating, but also induce fine nanocrystalline at the inter-particle interface of the micron coating by dynamic recrystallization.

In the context of the connotative development of higher education, the match between what college graduates have learned and what they have used and its causes has aroused the attention of society. Human capital and family capital are two important research perspectives when analyzing what graduates learn and what they use. The study selects professional ability, general ability and allocation ability to measure graduates' human capital and analyzes their family capital from three levels: economic, cultural and social. The study verified that human capital plays a mediating role in the influence of family capital on graduates' learning-application matching. Among the factors of human capital, professional ability and allocation ability have a significant positive influence on graduates' learning-application matching while general ability has a negative influence on graduates' learning-application matching. Family economic capital and family cultural capital have a significant positive influence on graduates' learning-application matching. Based on the findings of the empirical study, we propose countermeasures for universities to improve and enhance graduates' learning-application matching.

Objective: Doxorubicin (DOX) is commonly used for chemotherapy; however, its clinical value is extremely dampened because of the fatal cardiotoxicity. Leucine zipper protein 1 (LUZP1) plays critical roles in cardiovascular development, and this study is designed for determining its function and mechanism in DOX-induced cardiotoxicity. Methods: Cardiac-specific Luzp1 knockout (cKO) and transgenic (cTG) mice received a single or repeated DOX injections to establish acute and chronic cardiotoxicity. Biomarkers of inflammation, oxidative damage and cell apoptosis were evaluated. Transcriptome and co-immunoprecipitation analysis were used to screen the underlying molecular pathways. Meanwhile, primary cardiomyocytes were applied to confirm the beneficial effects of LUZP1 in depth. Results: LUZP1 was upregulated in DOX-injured hearts and cardiomyocytes. Cardiac-specific LUZP1 deficiency aggravated, while cardiac-specific LUZP1 overexpression attenuated DOX-associated inflammation, oxidative damage, cell apoptosis and acute cardiac injury. Mechanistic studies revealed that LUZP1 ameliorated DOX-induced cardiotoxicity through activating 5′-AMP-activated protein kinase (AMPK) pathway, and AMPK deficiency abolished the cardioprotection of LUZP1. Further findings suggested that LUZP1 interacted with protein phosphatase 1 to activate AMPK pathway. Moreover, we determined that cardiac-specific LUZP1 overexpression could also attenuate DOX-associated chronic cardiac injury in mice. Conclusion: LUZP1 attenuates DOX-induced inflammation, oxidative damage, cell apoptosis and ventricular impairment through regulating AMPK pathway, and gene therapy targeting LUZP1 may provide novel therapeutic approached to treat DOX-induced cardiotoxicity.

Background: Nonalcoholic fatty liver disease and chronic kidney disease are major public health issues worldwide. The clinical burden of nonalcoholic fatty liver disease is not only confined to liver-related morbidity and mortality, but it also includes the burden of chronic extrahepatic complications. It is well known that liver and kidney are strictly interconnected in physiological and pathological conditions. Summary: Mounting evidence indicates a strong association between nonalcoholic fatty liver disease and chronic kidney disease, independent of the identified cardiorenal risk factors. The presence and severity of nonalcoholic fatty liver disease are related to the developmental stage and risk of chronic kidney disease. And chronic kidney disease progression also contributes to nonalcoholic fatty liver disease development. Nonalcoholic fatty liver disease and chronic kidney disease mutually contribute to disease progression through pathological links. Shared pathogenic mechanisms also exist between nonalcoholic fatty liver disease and chronic kidney disease, including pyroptosis and ferroptosis. Additionally, the use of combined liver-kidney transplantation has increased exponentially in recent years. Key Messages: This review focuses on the emerging pathological mechanisms linking nonalcoholic fatty liver disease and chronic kidney disease and shared pathogenic mechanisms to find novel targeted therapies and retard the progression of both disease processes.

BackgroundPrevious experimental studies have reported an association between microcystin-LR (MC-LR) and glucose homeostasis, but whether exposure to MC-LR is a risk factor for the pathogenesis of gestational diabetes mellitus (GDM) requires further epidemiological study. This study aims to explore the effects of MC-LR on GDM.MethodsA prospective nested case-control study was performed in the Hunan Provincial Maternal and Child Health Hospital (HPMCHH) in South China. A total of 119 patients with GDM and 238 controls were enrolled in the study. The two independent samples t-test, or chi-square test was used to compare the difference between the GDM group and the non-GDM group. Binary logistic regression was used to obtain odds ratios (ORs) by controlling for confounders.ResultsThe cumulative incidence of GDM in our sample was 13.7%. The detection rate of MC-LR in the GDM group were significantly higher than those in the control group (44.2% vs. 29.4%; p=0.007). Our results show that an elevated serum MC-LR level in the first trimester of pregnancy was related to an increased risk of GDM (OR: 1.924; 95% CI: 1.092-3.391; p30 years, lower income, higher education, none passive smoking, and more likely to be multiparous.ConclusionsOur data reveals that serum MC-LR level in the first trimester is independently associated with GDM.

Background: Adrenocortical carcinoma (ACC) is a rare malignant endocrine tumor derived from the adrenal cortex. Because of its highly aggressive nature, the prognosis of patients with adrenocortical carcinoma is not impressive. Hypoxia exists in the vast majority of solid tumors and contributes to invasion, metastasis, and drug resistance. This study aimed to reveal the role of hypoxia in Adrenocortical carcinoma and develop a hypoxia risk score (HRS) for Adrenocortical carcinoma prognostic prediction.Methods: Hypoxia-related genes were obtained from the Molecular Signatures Database. The training cohorts of patients with adrenocortical carcinoma were downloaded from The Cancer Genome Atlas, while another three validation cohorts with comprehensive survival data were collected from the Gene Expression Omnibus. In addition, we constructed a hypoxia classifier using a random survival forest model. Moreover, we explored the relationship between the hypoxia risk score and immunophenotype in adrenocortical carcinoma to evaluate the efficacy of immune check inhibitors (ICI) therapy and prognosis of patients.Results: HRS and tumor stage were identified as independent prognostic factors. HRS was negatively correlated with immune cycle activity, immune cell infiltration, and the T cell inflammatory score. Therefore, we considered the low hypoxia risk score group as the inflammatory immunophenotype, whereas the high HRS group was a non-inflammatory immunophenotype. In addition, the HRS was negatively related to the expression of common immune checkpoint molecules such as PD-L1, CD200, CTLA-4, and TIGIT, suggesting that patients with a lower hypoxia risk score respond better to immunotherapy.Conclusion: We developed and validated a novel hypoxia risk score to predict the immunophenotype and response of patients with adrenocortical carcinoma to immune check inhibitors therapy. These findings not only provide fresh prognostic indicators for adrenocortical carcinoma but also offer several promising treatment targets for this disease.

BackgroundThe relationship between allergic diseases (AD) and mental disorders (MD) in women has not been fully systematically evaluated. We aimed at validating this correlation.MethodsThe relevant cohort and case-control studies from the establishment of the database to February 18, 2022 in PubMed, Embase, and Cochrane library were searched by computer. The researchers conducted the quality evaluation of the included articles by reviewing and discussing with reference to relevant standards, and conducted the analysis of the correlation between female patients with AD and MD by using Review Manager 5.4.ResultsSix observational studies from 2631 studies (n = 1160858 women) were assessed as medium and high-quality studies. The meta-analysis demonstrated that AD was correlated with MD in female patients (OR = 1.21, 95%CI: 1.14–1.29), including asthma (OR = 1.16, 95%CI: 1.11–1.22), allergic rhinitis (OR = 1.31, 95%CI: 1.06–1.63), and atopic dermatitis in women (OR = 1.37, 95%CI: 1.24–1.50) were associated with MD. At the same time, subgroup analysis was performed according to region, study design, criteria of AD and MD, and the results demonstrated that both AD and MD were correlated in these different conditions.ConclusionAllergic diseases in female patients do have an association with mental disorders.Systematic review registration[https://www.crd.york.ac.uk/PROSPERO/], identifier [CRD42022311146].

At the ecosystem level, Gross Primary Productivity (GPP) was defined as the organic compounds formed by plants that absorb atmospheric CO2 through photosynthesis and sequester carbon in plant bodies. How to accurately assess the spatiotemporal evolution of ecosystem carbon indicators has become a critical issue to be addressed. Chinese grasslands are located in a typical arid and semi-arid climate zone and are sensitive to global changes, which will inevitably have serious impacts on the function and structure of Chinese grasslands. Based on this, our paper takes Chinese grassland ecosystems as the research area, and used multi-source GPP dataset from terrestrial ecosystem model simulations and remote sensing satellite observations to quantitatively analyze the spatiotemporal evolution patterns of GPP in Chinese grasslands over the past 40 years. We combined trend analysis and breakpoint test, and then to analyze the mechanism components of GPP space–time variability. The main results are as follows: (1) The model and remote sensing estimated GPP results showed that more than 80% of Chinese grasslands show a significant increasing trend over the past 40 years, with growth rates ranging from 0.68 to 3.13 g C/m−2 year−1. (2) GPPmax also shows that more than 80% of Chinese grasslands are growing rapidly, with an overall growth rate of more than 0.1 g C/m−2 year−1 in each region. The overall long-term trends and interannual variability of multi-source GPP and GPPmax are generally consistent, yet vegetation dynamics in local areas are still uncertain. (3) The breakpoint test showed that ‘monotonically increasing’ was the largest breakpoint type of GPP in Chinese grasslands (33.09%), and the direction of change of GPP in Chinese grasslands before and after the breakpoint was also increasing. (4) GPPmax × CUP explained 91% of the temporal variability of annual-scale GPP in Chinese grasslands from a mechanistic view, and we found that the peak photosynthetic growth and the length of the phenological period synergistically controlled the interannual variability of GPP in Chinese grasslands. Under the scenario of rapid global change, our study accurately assessed the long-term dynamics of GPP and its mechanism-driven of grassland ecosystems in China, which is helpful for estimating and predicting the carbon budget of grassland ecosystems in China, and has important guiding significance for policy formulation to mitigate climate change.

Accurate quantitative estimation of soil organic carbon (SOC) and its storage is crucial for ecosystem response over desert areas, and is an important component of understanding dryland climate change, which can effectively reflect the processes and regulatory mechanisms in the carbon cycle. Nevertheless, the relationship between carbon sources and carbon sinks in sandy soils is a hotly debated subject. In particular, how plants and environmental conditions interact to affect SOC remains unclear in sandy deserts. Here, we investigated 77 sites at depths of 0–100 cm (soil depth was divided by 0–5 cm, 5–10 cm, 10–20 cm,20–30 cm, 30–50 cm, 50–70 cm and 70–100 cm intervals), collected 1617 soil samples, and obtained the climatic conditions, vegetation types, and edaphic factors associated with the sampling sites. This study aims to determine whether there are divisions in the allocation strategies of SOC by various vegetation types, and to analyze the mechanisms of environmental factors on the soil carbon pool in sandy deserts. Our results found that (1) the mean value of SOC in the sandy desert was 2.19 g·kg−1, which differed significantly among different vegetation types (P

In real-world automated manufacturing systems (AMSs), a breakdown of unreliable resources in operation often makes most existing deadlock control policies inapplicable. This work focuses on robust deadlock control problem in AMSs with multi-type and multi-unit unreliable resources. The unreliable resource's failure and repair activities are modeled by Petri nets. We introduce a concept of strong controllable siphon basis, which can be seen as an extension of the controllable siphon basis proposed in our previous work. Then by adding a control place with proper depth variable to each strict minimal siphon (SMS) and R-type SMS in a strong controllable siphon basis, we successfully develop a small-scaled robust deadlock controller for AMSs under consideration. Such a robust controller can guarantee that, as long as at least one unit of each unreliable resource type is available, all types of parts can be processed smoothly through any one of their routes even during downtime. Moreover, the number of control places of the proposed controller is no more than that of the activity places in the Petri net model and its size grows polynomially with Petri net model.

Background and aims: In practice, a grazing exclusion (GE) is an effective management method that is used to restore degraded grasslands across the world. However, the effect of GEs on soil organic carbon (SOC) and soil microbial diversity is highly controversial and needs further research across different regions. Methods: We investigated the impacts of short-term GEs (4–7 years) on SOC and soil bacterial diversity in sagebrush desert pastures on the northern slopes of Mt. Tianshan, Northwest China, with a paired experimental design. Five sagebrush desert sites were selected, namely, the Xinyuan plot, Bole plot, Manas plot, Hutubi plot, and Qitai plot. The SOC content was determined by using the Walkley-Black method, and soil bacterial diversity was analyzed by high-throughput gene detection. Results: Compared with freely grazed plots, short-term GEs decreased the SOC content and SOC stock in the 0–10 cm layer. GEs significantly decreased the SOC in the 0–10 cm layer by 14.94% and 53.42% in the Xinyuan and Qitai plots, respectively, and significantly increased the SOC by 14.7% in the 0–5 cm layer of the Bole plot (P 0.05). The relative abundances of Acidobacteria and Firmicutes in the 0–5 cm layer increased by 7.40% and 10.37% in the GE plots, while those in the 5–10 cm layer decreased by 5.08% and 69.62%, respectively (P > 0.05). GEs reduced the Chao1 index, Shannon index and Pielou index of the soil bacterial communities (P > 0.05). GEs reduced the effect of soil bacterial diversity on SOC content. Conclusion: The short-term GEs decreased the SOC content and SOC stock in the 0–10 cm layer in the sagebrush desert, and these values were even significantly reduced at some sites. Nevertheless, the short-term GEs had no significant effect on soil bacterial diversity or dominant bacteria such as Actinobacteria. Our results suggested that short-term GEs exhibited weak negative impacts on soil organic carbon and soil bacterial diversity in the sagebrush desert, and ecological restoration needs to be longer under grazing exclusions.

Partial pressure of oxygen (pO2) in the kidney is maintained at a relatively stable level by a unique and complex functional interplay between renal blood flow, glomerular filtration rate (GFR), oxygen consumption, and arteriovenous oxygen shunting. The vulnerability of this interaction renders the kidney vulnerable to hypoxic injury, leading to different renal diseases. Hypoxia has long been recognized as an important factor in the pathogenesis of acute kidney injury (AKI), especially renal ischemia/reperfusion injury. Accumulating evidence suggests that hypoxia also plays an important role in the pathogenesis and progression of chronic kidney disease (CKD) and CKD-related complications, such as anemia, cardiovascular events, and sarcopenia. In addition, renal cancer is linked to the deregulation of hypoxia pathways. Renal cancer utilizes various molecular pathways to respond and adapt to changes in renal oxygenation. Particularly, hypoxia-inducible factor (HIF) (including HIF-1, 2, 3) has been shown to be activated in renal disease and plays a major role in the protective response to hypoxia. HIF-1 is a heterodimer that is composed of an oxygen-regulated HIF-1α subunit and a constitutively expressed HIF-1β subunit. In renal diseases, the critical characteristic of HIF-1α is protective, but it also has a negative effect, such as in sarcopenia. This review summarizes the mechanisms of HIF-1α regulation in renal disease.

In this study, based on the working principle of the cardiac valve structure that prevents blood from flowing back, a piezoelectric pump with a cardiac valve-like structure (PPCVLS) is designed. The operating principles of cardiac-valve-like structures (CVLSs) are introduced. Furthermore, the closure conditions of the CVLSs on both sides of the flow channel are explored. The principle behind the working-state conversion between “valve-based” and “valve-less” of PPCVLS is also analyzed. A high-speed dynamic microscopic image-analysis system was utilized to observe and verify the working-state conversion between “valve-based” and “valve-less” PPCVLSs. The resonant frequency of the piezoelectric pump was measured by Doppler laser vibrometer, and the optimal working frequency of the piezoelectric vibrator was determined as 22.35 Hz. The prototype piezoelectric pump was fabricated by the 3D printing technique, and the output performance of the piezoelectric pump was also evaluated. The experimental results show that the piezoelectric pump is valve-based when the driving voltage is greater than 140V, and the piezoelectric pump is valve-less when the driving voltage is less than 140 V. Furthermore, the maximum output pressure of the piezoelectric pump was 199 mm H2O when driven by the applied voltage of 220 V at 7 Hz, while the maximum flow rate of the piezoelectric pump was 44.5 mL/min when driven by the applied voltage of 220 V at 11 Hz.

Background. Diabetes mellitus (DM) is a prognostic marker in elderly patients with cardiovascular diseases, but its predictive value in elderly valvular heart disease (VHD) patients is unclear. This study aimed to investigate the effect of DM on the long-term outcome of elderly VHD patients. Methods. This single-center, observational study enrolled patients aged 65 and older consecutively with confirmed VHD using echocardiography. Patients, divided into the DM group and non-DM group, were followed up for major adverse cardiac and cerebrovascular events (MACCEs), including all-cause death, ischemic stroke, and heart failure rehospitalization. Results. Our study consisted of 532 patients over a median follow-up of 52.9 months. Compared with the non-DM group (n = 377), the DM group (n = 155) had higher incidences of ischemic stroke (25.2% vs. 13.5%, P=0.001), heart failure rehospitalization (37.4% vs. 20.7%, P

A few clinical trials have recently reported the potential effect of colchicine in preventing post-operative atrial fibrillation (POAF) and early atrial fibrillation (AF) recurrence after catheter pulmonary vein isolation. However, the molecular mechanisms through which colchicine inhibits AF remain unclear. We aim to assess the anti-AF effect of colchicine in the rat sterile pericarditis (SP) model and to investigate its molecular mechanisms. SP was induced in Sprague-Dawley rats by the epicardial application of sterile talc. Treatment with colchicine or vehicle began 1 d before pericardiotomy. AF was induced by transesophageal burst pacing on day 3 after surgery. Treatment with colchicine reduced the duration of AF and the probability of induction of AF in SP rats. The dose of 0.5 mg kg−1·day−1 had the best effect. Such treatment also reduced neutrophil infiltration, the mRNA expression of IL-6, TGF-β, and TNF-α, atrial fibrosis, fibrosis related genes, and signal molecules (STAT3, P38, and AKT). Meanwhile, the release of IL-1β (4−24 h) and IL-6 (4−72 h) in atria after surgery was significantly inhibited by colchicine. In cultured rat cardiac fibroblasts, colchicine treatment inhibited IL-1β-induced expression of IL-6, which was accompanied by significantly decreased phosphorylation of P38, AKT, JNK, and NFκB. Interestingly, the supplementation of IL-6 abolished the anti-AF effect of colchicine in SP rats. Colchicine prevents AF in SP rats through the inhibition of IL-1β-induced IL-6 release and subsequent atrial fibrosis. However, further studies are required to investigate whether colchicine inhibits POAF through other mechanisms.

Ca2+ entry via the transient receptor potential vanilloid 4 (TRPV4) channel contributes to Ca2+ overload and triggers many pathophysiological conditions, including myocardial ischemia/reperfusion (I/R) injury. Propofol, a widely used intravenous anesthetic, attenuates myocardial I/R injury. However, the mechanism of propofol remains to be examined. The present study aims to test the hypothesis that propofol attenuates myocardial I/R injury through the suppression of TRPV4. We used a murine ex vivo model of myocardial I/R and in vitro cultured myocytes subjected to hypoxia/reoxygenation (H/R). Propofol or TRPV4 antagonist, HC-067047, attenuates myocardial I/R injury in isolated hearts. In addition, propofol, HC-067047, or TRPV4-siRNA attenuates H/R-induced intracellular Ca2+ concentration ([Ca2+]i) increase and cell viability reduction. On the contrary, TRPV4 agonist GSK1016790A exacerbates both ex vivo and in vitro myocardial injury. Pretreatment with propofol reverses the myocardial injury and intracellular Ca2+ overload induced by GSK1016790A at least in vitro. However, neither the combination of propofol and HC-067047 nor applying propofol to cells transfected with TRPV4-siRNA creates additional protective effects. In addition, propofol dose-dependently inhibits TRPV4-mediated Ca2+ entry induced by GSK1016790A and 4α-PDD. Propofol attenuates myocardial I/R injury partially through the suppression of TRPV4 channel and the subsequent inhibition of intracellular Ca2+ overload.

Abstract Excessive secretion of glucagon, a functional insulin antagonist, significantly contributes to hyperglycemia. Glucagon exerts its physiological functions through activation of the glucagon receptor (GCGR). Inhibition of GCGR activity represents a potential therapeutic approach for reducing excess glucose production in diabetes mellitus. Aptamers are short DNA or RNA oligonucleotides evolved from systematic evolution of ligands by exponential enrichment (SELEX). Here, we have successfully selected a DNA aptamer against GCGR by cell-SELEX, which can specifically bind membrane protein of CHO-GCGR cells with a K d of 52.7 ± 5.1 nM. Aptamer-mediated pull-down and gcgr knockdown assay verified that GCGR was the target of aptamer GR-3. Binding analysis revealed that GR-3 could recognize other cells with different affinity according to the level of GCGR protein expressed in these cells. Hepatic tissue imaging suggested that GR-3 could bind the cell membrane of hepatic tissues. With the advantages of small size, high binding affinity, good stability, lack of immunogenicity, and easy synthesis, aptamer GR-3 against GCGR can be a promising tool with the potential to attenuate hyperglycemia in diabetes mellitus.

The fragmentation mechanism of copper sheet in laser dynamic forming (LDF) process is investigated. The investigation of the fragmentation mechanism in the moving sample is quite difficult, so finite element method is adopted to provide detailed information on the stress state during micro-forming. The shock loading was generated using laser-shock-rubber loading technique in which a layer of rubber is inserted to improve laser shock efficiency. When laser power density is 0.491 GW cm ^−2 , the obvious circular fragmentation is located at the center region of rear surface. When laser power density is 0.658 GW cm ^−2 , the diameter of the fragmentation region increased, and what’s more, circumferential and radial cracks were formed in the fragmentation region. The void linkages and terrace-like pattern were also observed. Finite element model reveals that the fragmentation in the moving sheet is not caused by the initial rubber direct loading, but the deceleration at the last stage of forming. Because the curvature in the tip has the highest value at the stopping point, deceleration passes through its maximum value and then causes fragmentation at the last stage of forming. When laser power density is 0.658 GW cm ^−2 , the single layer fragmentation, multiple layer fragmentation, circumferential crack, and radial cracks occur in that sequence.

Laser pre-shocking (LPS) was introduced into the laser dynamic flexible micropunching process to refine the grain size of a workpiece to improve the forming quality of punched parts. T2 copper foils with five different grain sizes and seven different laser power densities with and without LPS were used for the experiment. The results showed that the grains are refined and the average surface roughness Ra decreases after LPS. For copper foils annealed at 650 °C, the value of Ra decreases from 0.430 to 0.363 µm. The increase in laser energy density and grain size leads to the deterioration of the fracture surface. LPS can improve the quality of the fracture surface. Compared with punched holes without LPS, the dimensional accuracy and shape accuracy of punched holes can be improved by LPS. When grain size is close to the thickness of the copper foil, the forming quality of the punched parts becomes uncertain, owing to the difference in the orientation of the initial grains. The instability of laser dynamic flexible micropunching can be reduced by LPS. Especially, the improvement of forming quality of the punched part brought by LPS is significant for the copper foils with coarse grains.

In automated manufacturing systems, resource failures are often inevitable. They reduce the number of available resources and may cause some processing routes of parts to halt and sometimes the whole system to shutdown. This article focuses on the robust deadlock control problem in automated manufacturing systems with multiple resource failures. To obtain such a robust controller, we first put forward a new concept of blocked states of automated manufacturing systems. From such a state, the production of some part types through one of their routes is blocked as caused by resource failures, and only after some failed resources are repaired, these parts can resume their normal processing. Then, these blocked states are characterized in terms of emptied siphons caused by resource failures. In order to prevent the system from deadlocks and blocked states, a robust controller is proposed by the following two steps. First, for siphons without unreliable resources, optimal deadlock control places are added. Then for siphons which contain unreliable resources, new control places are devised to ensure that they could be marked even when resource failures happen. It is proved that the proposed controller can guarantee that all types of parts can be processed repeatedly as long as one unit of unreliable resources can still work. This means that the proposed controller is of greatest robustness, that is, it can tolerate a maximum number of resource failures. Some examples are provided to illustrate the proposed method and show the advantage over the previous ones.

Polypropylene and PA66 are widely used in our daily life, but they cannot be welded by laser transmission welding (LTW) because of polar differences and poor compatibility. In this paper, grafting modification technology is used to improve the welding performance between polypropylene and PA66. Firstly, the strong reactive and polar maleic-anhydride (MAH) is grafted to polypropylene and infrared spectrometer is used to prove that MAH has been grafted to polypropylene. At the same time, the mechanical and thermal properties of the graft modified polypropylene (TGMPP) are tested. The results prove that the grafting modification has little influence on them. Also, the optical properties of TGMPP are measured. Then, the high welding strength between TGMPP and PA66 is found and the mechanism of the weldability is researched, which shows that there are two reasons for the high welding strength. By observing the micro morphology of the welding zone, one reason found is that the modification of polypropylene can improve the compatibility between polypropylene and PA66 and make them easy to diffuse mutually, which causes many locking structures formed in the welding region. The other reason is that there are chemical reactions between TGMPP and PA66 proved by the X-ray photoelectron spectrometer.

The aim of this paper is to fabricate micro-gears via laser shock punching with Spitlight 2000 Nd-YAG Laser, and to discuss effects of process parameters namely laser energy, soft punch properties and blank-holder on the quality of micro-gears deeply. Results show that dimensional accuracy is the best shocked at 1690 mJ. Tensile fracture instead of shear fracture is the main fracture mode under low laser energy. The soft punch might cause damage to punching quality when too high energy is employed. Appropriate thickness and hardness of soft punch is necessary. Silica gel with 200 µm in thickness is beneficial to not only homogenize energy but also propagate the shock wave. Polyurethane films need more energy than silica gel with the same thickness. In addition, blank-holders with different weight levels are used. A heavier blank-holder is more beneficial to improve the cutting quality. Furthermore, the simulation is conducted to reveal typical stages and the different deformation behavior under high and low pulse energy. The simulation results show that the fracture mode changes under lower energy.

Isolated from Dictamnus dasycarpus Turcz., fraxinellone exhibited multiple bioactivities against insects. In the present paper, the changes of digestive enzymes and detoxification enzymes of Mythimna separata Walker (5th instar larvae), treated with fraxinellone, were investigated. Compared with those of the control, the α-amylase activity of the fraxinellone-treated 5th instar larvae was inhibited, whereas the level of their protease activity was increased. Based upon further studies on the specific proteases, the levels of the active alkaline trypsin-like enzyme (BApNA as the substrate) and the chymotrypsin-like enzyme (BTEE as the substrate) activities of the treated larvae were declined; however, the level of activity of the weak alkaline trypsin-like enzyme (TAME as the substrate) of the treated ones was increased. Meanwhile, the activities of two detoxification enzymes, such as carboxylesterase (CarE) and glutathione S-transferase (GST), of the treated larvae were increased to some extent, but the activities of NADPH-P450 reductase and O-demethylase of the treated ones declined. Therefore, protease (especially the weak alkaline trypsin-like enzyme), CarE and GST played important roles in the metabolism of fraxinellone in the midgut of Mythimna separata (M. separata).

Plasticine is widely used in the analysis of metal forming processes, due to its excellent material flow ability. In this study, plasticine is used as the soft punch to fabricate array micro-channels on metal sheet in the micro sheet stamping process. This is because plasticine can produce a large material flow after being subjected to force and through the material flow, the plasticine can cause the sheet to fill into the micro-channels of the rigid die, leading to the generation of micro-channels in the sheet. The distribution of array micro-channels was investigated as well as the influence of load forces on the sheet deformations. It was found that the depth of micro-channels increases as the load force increases. When the load force reaches a certain level, a crack can be observed. The micro sheet stamping process was also investigated by the method of numerical simulation. The obtained experimental and numerical results for the stamping process showed that they were in good agreement. Additionally, from the simulation results, it can be seen that the corner region of the micro-channel-shape work piece has a risk to crack due to the existence of maximum von Mises stress and significant thinning.

This work proposes a micro-shear clinching process by laser shock for joining similar and dissimilar metal foils. The joint appearance and cross-section were investigated to determine basic process parameters. The soft punch thickness was 100 μm. The numbers of laser pulses on the upper and lower foil sides were set as two and one, respectively. Joint deformation was divided into three stages and we investigated the deformation law of the joints. The process windows of the Al foil combinations were acquired to determine a reasonable range of process parameters for obtaining qualified joints. The mechanical properties and failure modes of different joints were analyzed to identify the process characteristics. Mechanical properties were related to shear test directions and were influenced by upper and lower foil thicknesses. One failure mode was observed in the parallel shear test, and four failure modes were observed in the perpendicular shear test. These modes were determined by the differences between upper and lower foil thicknesses. Results showed that the proposed process can be used to join Al and Cu foils successfully. The laws governing the mechanical properties and failure modes of dissimilar materials were similar to those governing the mechanical properties and failure modes of similar materials.

Laser surface treatment of the titanium alloy was locally oxidized on the metal surface to improve the joint strength of laser transmission welding of high borosilicate glass with titanium alloy. The results find that the welding strength was increased 5 times. The welding mechanism was investigated by the morphology of the welded parts, the tensile-fracture failure mode, the diffusion of the interface elements, and the surface free energy. The results show that there are many adherents between the titanium alloy and high borosilicate glass after tensile fracture, the welding strength was higher when the laser voltage was 460 V, and the tensile–fracture failure mode is mainly ductile fracture. Element-line scanning analysis revealed that elemental diffusion occurred in the two materials, which is an important reason for the high welding strength. Surface free-energy analysis shows that laser surface treatment improves the surface free energy of titanium alloy, promotes the wettability and compatibility, and increases the welding strength of titanium alloy with glass.

Fraxinellone, a well-known and significant naturally occurring compound isolated from Meliaceae and Rutaceae spp. has been widely used as a drug for the treatment of tumors. On the other hand, fraxinellone exhibited a variety of insecticidal activities including feeding-deterrent activity, inhibition of growth, and larvicidal activity. The present study focused on the antifeedant and larvicidal activities of fraxinellone against the larvae of Lepidoptera, including Mythimna separata, Agrotis ypsilon, Plutella xylostella, and one kind of sanitary pest, Culux pipiens pallens. Meanwhile, the ovicidal activities and the effects of fraxinellone on the larval development of M. separata were also observed. The LC50 values of fraxinellone against 3rd instar larvae of M. separata, 2nd instar larvae of P. xylostella and 4th instar larvae of C. pipiens pallens were 15.95/6.43/3.60 × 10−2 mg mL−1, and its AFC50 values against 5th instar larvae of M. separata, 2nd instar larvae of P. xylostella and 2nd instar larvae of A. ypsilon were 10.73/7.93/12.58 mg mL−1, respectively. Compared with the control group, fraxinellone obviously inhibited the pupation rate and the growth of M. separata. Once M. separata was treated with fraxinellone at concentrations of 5.0, 10.0, and 20.0 mg mL−1, respectively, the stages from the larvae to adulthood and the egg hatching duration were prolonged to 1/2/3, and 4/3/4 days, respectively. Additionally, fraxinellone strongly inhibited the development rate and the egg hatch proportion of M. separata.

Objective. Hypoxia-induced sustained contraction of porcine coronary artery is endothelium-independent and mediated by PI3K/Akt/Rho kinase. Nitroglycerin (NTG) is a vasodilator used to treat angina pectoris and acute heart failure. The present study was to determine the role of NTG in hypoxia-induced endothelium-independent contraction and the underlying mechanism. Methods and Results. Organ chamber technique was used to measure the isometric vessel tension of isolated porcine coronary arteries. Protein levels of phosphorylated and total Akt were determined by western blot. A sustained contraction of porcine coronary arteries induced by hypoxia was significantly reduced by NTG but not by isoproterenol. This contraction was also inhibited by DETA NONOate, 8-Br-cGMP, which can be reversed by ODQ, and Rp-8-Br-PET-cGMPS. The restored contraction was blocked by LY294002. The reduction of Akt-p at Ser-473 by NTG, DETA NONOate, and 8-Br-cGMP was significantly inhibited by ODQ, PKG-I. The decrease in Akt-p level by NTG and 8-Br-cGMP was prevented by calyculin A but not by okadaic acid. Conclusions. These results demonstrated that the endothelium-independent sustained hypoxic vasoconstriction can be prevented by NTG and that the inhibition of PI3K/Akt signaling pathway may be involved.

Aptamers are single-stranded oligonucleotides of DNA or RNA that bind to target molecules with high affinity and specificity. Typically, aptamers are generated by an iterative selection process, called systematic evolution of ligands by exponential enrichment (SELEX). Recent advancements in SELEX technology have extended aptamer selection from comparatively simple mixtures of purified proteins to whole living cells, and now cell-based SELEX (or cell-SELEX) can isolate aptamers that bind to specific target cells. Combined with nanotechnology, microchips, microfluidic devices, RNAi and other advanced technologies, cell-SELEX represents an integrated platform providing ultrasensitive and highly specific tools for clinical medicine. In this review, we describe the recent progress made in the application of cell-SELEX for diagnosis, therapy and biomarker discovery.

To address the difficulty of joining polystyrene (PS) and titanium by laser transmission joining, two methods—laser treatment of the titanium surface and oxygen plasma treatment of the PS surface—are used to compare the laser transmission joint strengths of the different treatment methods. The results of the experiments find that joining with titanium can be achieved only when PS is treated with oxygen plasma. When the laser-treated surface of titanium is jointed to the oxygen plasma-treated PS, the joint strength is the highest, reaching 6.5 MPa. The joining mechanism of oxygen plasma-treated PS and laser oxidation-treated titanium was investigated by joint tensile failure mode, joint micromorphology observation, contact angle and surface free energy experiments, and X-ray photoelectron spectroscopy (XPS). The results show that the failure mode of the joint is an interfacial failure; the size and amount of bubbles play an important role in the joining strength, and the joints with fine and uniform bubbles have the highest joint strength. The two surface treatment methods can improve the surface energy of the joints, improve the compatibility between the two joining surfaces, and enhance the joint strength. Ti–C and Ti–O chemical bonds are formed at the joints, which are the main reason for the increase in joint strength.

A novel high strain rate microforming technique, laser impact liquid flexible embossing (LILFE), which uses laser induced shock waves as an energy source, and liquid as a force transmission medium, is proposed by this paper in order to emboss three-dimensional large area micro arrays on metallic foils and to overcome some of the defects of laser direct shock microembossing technology. The influences of laser energy and workpiece thickness on the deformation characteristics of the pure copper foils with the LILFE process were investigated through experiments and numerical simulation. A finite element model was built to further understand the typical stages of deformation, and the results of the numerical simulation are consistent with those achieved from the experiments. The experimental and simulation results show that the forming accuracy and depth of the embossed parts increases with the increase in laser energy and decrease in workpiece thickness. The thickness thinning rate of the embossed parts increases with the decrease of the workpiece thickness, and the severest thickness thinning occurs at the bar corner region. The experimental results also show that the LILFE process can protect the workpiece surface from being ablated and damaged, and can ensure the surface quality of the formed parts. Besides, the numerical simulation studies reveal the plastic strain distribution of embossed microfeatures under different laser energy.

Due to their large compatibility difference, polyethylene (PE) and polyoxymethylene (POM) cannot be welded together by laser transmission welding. In this study, PE and POM are pretreated using plasma that significantly enhances their laser transmission welding strength. To understand the mechanism underlying the laser welding strength enhancement, surface modification is analyzed using contact angle measurements, atomic force microscopy (AFM), optical microscopy, and X-ray photoelectron spectroscopy (XPS). Characterization results show that the plasma surface treatment improves the surface free energy, significantly enhancing the wettability of the materials. The increase in surface roughness and the generation of homogeneous bubbles contribute to the formation of mechanical micro-interlocking. The oxygen-containing groups introduced by the oxygen plasma treatment improve the compatibility of PE and POM, and facilitate the diffusion and entanglement of molecular chains and the formation of van der Waals force.

The purpose of this paper is to present an advanced method for welding fine wire to metal sheet, namely laser indirect shock welding (LISW). This process uses silica gel as driver sheet to accelerate the metal sheet toward the wire to obtain metallurgical bonding. A series of experiments were implemented to validate the welding ability of Al sheet/Cu wire and Al sheet/Ag wire. It was found that the use of a driver sheet can maintain high surface quality of the metal sheet. With the increase of laser pulse energy, the bonding area of the sheet/wire increased and the welding interfaces were nearly flat. Energy dispersive spectroscopy (EDS) results show that the intermetallic phases were absent and a short element diffusion layer which would limit the formation of the intermetallic phases emerging at the welding interface. A tensile shear test was used to measure the mechanical strength of the welding joints. The influence of laser pulse energy on the tensile failure modes was investigated, and two failure modes, including interfacial failure and failure through the wire, were observed. The nanoindentation test results indicate that as the distance to the welding interface decreased, the microhardness increased due to the plastic deformation becoming more violent.

Microscale laser dynamic flexible forming (µLDFF) is a novel ultrahigh strain rate manufacturing technology with high efficiency and low cost. However, the µLDFF is just confined to single-layer foil at present. In this work, sheet metal laminates (Cu/Ni) were selected as the experimental material for its excellent mechanical and functional properties, and a new micro-bending method of sheet metal laminates by laser-driven soft punch was proposed in warm conditions. The micro-mold and warm platform were designed to investigate the effects of temperature and energy on formability, which were characterized by forming accuracy, surface quality, element diffusion, and so on. The experimental results show that the forming accuracy and quality increased first and then decreased with laser energy, but the hardness increased consistently. In warm conditions, the fluidity of material was improved. The forming depth and accuracy increased for the relieved springback, and the surface quality increased first and then decreased. The tensile fracture disappeared with temperature for the decreased hardness and thinning ratio, and the element diffusion occurred. Overall, this study indicates that the formability can be improved in warm conditions and provides a basis for the investigation of micro-bending of sheet metal laminates by µLDFF in warm conditions.

Multilayer metal composite sheets possess superior properties to monolithic metal sheets, and formability is different from monolithic metal sheets. In this research, the feature size effect on formability of multilayer metal composite sheets under microscale laser flexible forming was studied by experiment. Two-layer copper/nickel composite sheets were selected as experimental materials. Five types of micro molds with different diameters were utilized. The formability of materials was evaluated by forming depth, thickness thinning, surface quality, and micro-hardness distribution. The research results showed that the formability of two-layer copper/nickel composite sheets was strongly influenced by feature size. With feature size increasing, the effect of layer stacking sequence on forming depth, thickness thinning ratio, and surface roughness became increasingly larger. However, the normalized forming depth, thickness thinning ratio, surface roughness, and micro-hardness of the formed components under the same layer stacking sequence first increased and then decreased with increasing feature size. The deformation behavior of copper/nickel composite sheets was determined by the external layer. The deformation extent was larger when the copper layer was set as the external layer.

Laser flexible shock micro-bulging (LFSB) is a novel micro fabrication technology, which combines laser dynamic forming and flexible die forming, which is a type of high strain rate micro-forming. The LFSB of 304 stainless steel foils was investigated in this paper. Experimental and simulated results indicated that the bulging depth and thickness thinning rate of bulging parts increased with an increase of laser energy and a decrease of workpiece thickness. Experimental results also showed the surface morphology of bulging parts. The hardness distribution in the cross section of bulging parts was revealed by nanoindentation experiments. The internal microstructure of micro bulging parts was observed by TEM. In addition, the equivalent stress and plastic strain distribution of bulging parts were shown in the numerical simulation under different workpiece thicknesses and laser energies.

To satisfy the need of polymer connection in lightweight automobiles, a study on laser transmission spot welding using polymethyl methacrylate (PMMA) is conducted by using an Nd:YAG pulse laser. The influence of three variables, namely peak voltages, defocusing distances and the welding type (type I (pulse frequency and the duration is 25 Hz, 0.6 s) and type II (pulse frequency and the duration is 5 Hz, 3 s)) to the welding quality was investigated. The result showed that, in the case of the same peak voltages and defocusing distances, the number of bubbles for type I was obviously more than type II. The failure mode of type I was the base plate fracture along the solder joint, and the connection strength of type I was greater than type II. The weld pool diameter:depth ratio for type I was significantly greater than type II. It could be seen that there was a certain relationship between the weld pool diameter:depth ratio and the welding strength. By the finite element simulation, the weld pool for type I was more slender than type II, which was approximately the same as the experimental results.

This paper describes a novel technique for joining similar and dissimilar metal foils, namely micro clinching with cutting by laser shock forming. A series of experiments were conducted to study the deformation behavior of single layer material, during which many important process parameters were determined. The process window of the 1060 pure aluminum foils and annealed copper foils produced by micro clinching with cutting was analyzed. Moreover, similar material combination (annealed copper foils) and dissimilar material combination (1060 pure aluminum foils and 304 stainless steel foils) were successfully achieved. The effect of laser energy on the interlock and minimum thickness of upper foils was investigated. In addition, the mechanical strength of different material combinations joined by micro clinching with cutting was measured in single lap shearing tests. According to the achieved results, this novel technique is more suitable for material combinations where the upper foil is thicker than lower foil. With the increase of laser energy, the interlock increased while the minimum thickness of upper foil decreased gradually. The shear strength of 1060 pure aluminum foils and 304 stainless steel foils combination was three times as large as that of 1060 pure aluminum foils and annealed copper foils combination.

Compound process technology has been investigated for many years on a macro scale, but only a few studies can be found on a micro scale due to the difficulties in tool manufacturing, parts transporting and punch-die alignment. In this paper, a novel technology of combining the laser shock wave and soft punch was introduced to fabricate the dish-shaped micro-parts on copper to solve these difficulties. This compound process includes deep drawing, punching and blanking and these processes can be completed almost at the same time because the duration time of laser is quite short, so the precision of the micro-parts can be ensured. A reasonable laser energy of 1550 mJ made the morphology, depth of deformation, dimensional accuracy and surface roughness achieve their best results when the thickness of the soft punches was 200 μm. In addition, thicker soft punches may hinder the compound process due to the action of unloading waves based on the elastic wave theory. So, the greatest thickness of the soft punches was 200 μm.