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Joining dissimilar metals is a major challenge in joining technology; the weldability of immiscible systems is especially challenging. In this study, a design methodology for dissimilar welding is suggested. The Miedema model and Toop model are developed to calculate the thermodynamics of quaternary alloy systems (Mg-Fe-Al-Cu). Finite element modelling (FEM) of temperature fields and the calculation of phase diagrams (CALPHAD) are combined to provide prerequisite information for modelling. As a test subject, laser welded lap configuration joints of AZ31B magnesium alloy and DP590 steel with a copper coating were put into the design scheme. The interfacial elemental diffusion and formation of intermetallics (IMCs) along the interface during the welding process are predicted. This simulation design scheme predicts the interfacial reaction kinetics and identifies whether the intermediate element works or not. The effects of the Cu coating thickness on the weld constitution, interfacial microstructures and mechanical properties were studied. Cu coating promotes the weld formation fostering the metallurgical reaction of the fusion zone (FZ) with the steel brazing interface. The mechanism of interfacial reactions during the welding-brazing process has been clarified. The Vickers hardness distribution across the interface shows that the Cu-IMCs are ductile.

TIG-Dressing treatment is often used for steel welded joints in construction machinery manufacturing as an effective and reliable method for post-weld fatigue strength improvement. This paper investigates the fatigue performance of thick Q355D cruciform joints in heavy load-carrying steel structures under different TIG-Dressing treatments. Two TIG-Dressing treatments for the full-penetration welded joints were used for fatigue tests considering filling metal during this post-welded processing. Experimental tests studied the fatigue strength of TIG-Dressing cruciform welded joints of Q355D structural steel. The geometric parameters and relevant statistical analyses were performed by actual 3D optical measurement. Moreover, the stress concentration factors are calculated according to the actual geometrics of the welded joint. On the other hand, the effective notch stress and hot spot stress methods were employed to evaluate the fatigue data of Load-Carrying Welded joints (LCWJs) under different notch radius. The collected fatigue data from the literature was compared with the tested data by the above methods. The results show that the fatigue strength of LCWJs under TIG-Dressing processing without filler metal is higher than those under the same TIG-Dressing treatment with filler metal. The effective notch stress method with a fictitious notch radius r = rtrue + 1 mm (rtrue is the actual notch radius at weld toe) could obtain smaller scatter bands for the tested fatigue data.

Laser texturing is a promising technology with wide-ranging applications in surface processing. In this study, a nanosecond laser was used to ablate the surface of Q355 steel, creating grooves of varying depths by different processing times. Satisfactory Al/Steel joints were obtained under different groove depths (0 μm, 6 μm, 26 μm and 56 μm). Interfacial microstructure evolutions were investigated and the observed results indicated that introduction of texture would enhance interfacial specific surface area, promote degree of atomic diffusion, thicken interfacial IMCs (intermetallic metallic compounds) while maintain interfacial reaction (η-Fe2(Al,Si)5 + θ-Fe(Al,Si)3). Numerical simulations results illustrated that existence of texture would reduce interfacial peak residual stress, homogenize residual stress distribution and induce compressive stress in the groove. Highest strength of 111 MPa with the fracture mode of tough-brittle compound fracture was produced in the joint when laser texturing processing times were 20, which was nearly 40 % higher compared to the untreated joint (80 MPa). This study provides a novel method to improve joints mechanical properties for laser welding-brazing of Al/Steel system, which may also provide a theoretical reference for the application of other dissimilar metal systems.

Abstract Lung cancer ranks as one of the top malignancies and the leading cause of cancer death in both males and females in the US. Using a cancer database covering the entire population, this study was to determine the gender disparities in lung cancer incidence during 2001–2019. Cancer patients were obtained from the National Program of Cancer Registries (NPCR) and Surveillance, Epidemiology and End Results (SEER) database. The SEER*Stat software was applied to calculate the age-adjusted incidence rates (AAIR). Temporal changes in lung cancer incidence were analyzed by the Joinpoint software. A total of 4,086,432 patients (53.3% of males) were diagnosed with lung cancer. Among them, 52.1% were 70 years or older, 82.7% non-Hispanic white, 39.7% from the South, and 72.6% non-small cell lung cancer (NSCLC). The AAIR of lung cancer continuously reduced from 91.0 per 100000 to 59.2 in males during the study period, while it increased from 55.0 in 2001 to 56.8 in 2006 in females, then decreased to 48.1 in 2019. The female to male incidence rate ratio of lung cancer continuously increased from 2001 to 2019. Gender disparities were observed among age groups, races, and histological types. In those aged 0–54 years, females had higher overall incidence rates of lung cancer than males in recent years, which was observed in all races (except non-Hispanic black), all regions, and adenocarcinoma and small cell (but not squamous cell). Non-Hispanic black females aged 0–54 years had a faster decline rate than males since 2013. API females demonstrated an increased trend during the study period. Lung cancer incidence continues to decrease with gender disparities among age groups, races, regions, and histological types. Continuous anti-smoking programs plus reduction of related risk factors are necessary to lower lung cancer incidence further.

Al matrix composites (AMCs) are preferred engineering materials for aerospace and automotive industries owing to their high specific strength, superior wear resistance and low thermal expansion. It is a challenge to achieve high-quality fusion welded joints of AMCs because of the occurrence of defects such as pores, particles segregation and acicular phases. In this study, the effects of laser welding parameters including laser power, welding speed and laser incident angle on the formation of porosity and acicular phase were investigated in SiCp/6092 aluminum matrix composite welded joints using orthogonal experimental method. Range analysis of the orthogonal test results showed that the laser power and the welding speed had the greatest influence on the porosity and acicular phase size during the laser welding of aluminum matrix composites. At a heat input of 60 J/mm, the porosity in the weld was only 1.6% while that at 190 J/mm was 15.2%. Higher heat input produced a much larger size of brittle Al4C3 phases. The size of the acicular phase Al4C3 at the top and bottom of the weld was larger than that in the middle. Active Ti was added to the weld zone to mitigate the adverse effect of Al4C3 brittle phase and porosity on mechanical properties. The ultimate tensile strength increased from 115 MPa in direct laser welding to 148 MPa for the laser welding process employing the Ti interlayer. This work will provide referenceable data for designing high-quality AMC welded joints for aerospace and automotive industries.

Friction stir welding (FSW) is a new solid-state joining process for joining light metals, such as magnesium (Mg) alloys. However, the texture-induced softening mechanism (in stir zone, SZ) tends to cause the worsening of mechanical properties in FSW Mg alloys. In this work, multi-pass hot-rolling and subsequent annealing is used to ameliorate the FSW AZ31 alloy plate. The results show that multi-pass hot-rolling leads to the c-axes of most grains in the SZ approximately perpendicular to the normal direction (ND) transforming into these almost parallel to the ND, accompanied with multiple twin types. After subsequent annealing, twins, as nucleation sites, promote the formation of new grains with off-basal texture, resulting in the weak basal texture. Compared with the FSW plate and the initial plate, the rolled-annealed FSW plate exhibits a relatively uniform hardness distribution and a “strength-ductility” synergy, which are mainly attributed to an appropriate texture feature and a homogeneous grain structure. This work provides a new idea for the development of new high-performance FSW Mg alloys.

In this research, satisfactory Al/steel butt joint was obtained by the dual spot laser welding-brazing technology with various spot configurations (+45° biased to steel side, in-line, -45° biased to Al side). The results showed that the interfacial IMC (Intermetallic compound) were composed of η–Fe2(Al,Si)5 and θ–Fe(Al,Si)3 for three joints. The interfacial IMC thickness reduced when the laser spot was biased from steel to Al side. In addition, IMC with larger thickness was produced at the top and middle regions than that of bottom region. The η–Fe2(Al,Si)5/steel interface would be changed from straight to finger-shaped with the reduction of η–Fe2(Al,Si)5 layer thickness. Numerical simulation showed that interfacial IMC thickness variations were resulted from the difference of peak temperatures: higher peak temperatures, thicker interfacial IMC. Analysis of fractured behaviors presented that fractured locations would be changed with the reduction interfacial IMC thickness: from η–Fe2(Al,Si)5 layer to η–Fe2(Al,Si)5 layer and θ–Fe(Al,Si)3 and finally to θ–Fe(Al,Si)3 and partial weld seam when interfacial IMC thickness reduced from 6.1 μm to 5.1 μm and finally to 3.4 μm. Tensile strength values showed that fractured location of θ–Fe(Al,Si)3 and partial weld seam in the interface joined with 2.9–3.5 μm Fe2(Al,Si)5 layer and θ–Fe(Al,Si)3 was most beneficial for interfacial strength and highest tensile strength of 142 MPa was obtained.

The instability of rock mass induced by the deterioration and failure of rock bridge is often encountered in hard rock engineering. Under engineering disturbance, a steep and gentle stepped sliding surface is prone to forming along the rock bridges between the intermittent rock joints, which directly controls the rock mass instability modes. In order to reveal the influence of fissure angle on the fatigue deterioration and energy evolution mechanism of stepped double-flawed hard rock, the multilevel cyclic loading mechanical test were carried out on flawed marble samples with fissure angle of 10°, 30°, 50°, and 70° angles. The testing shows that rock strength, fatigue lifetime, peak strain and dissipated energy increase with increasing fissure angle and the increase rate of them becomes sharply in the high cyclic level. In addition, the increase of dissipated energy accelerates with the increase of cyclic loading level, and shows a sudden increase trend in the last cyclic loading stage. When the joint fissure angle is 10°, the dissipated energy is the smallest and the dissipated energy is the largest at 70°. Moreover, a damage evolution model based on dissipated energy is established to describe the characteristics of damage accumulation. The model is in good agreement with the experimental data and reflects the nonlinear characteristics of damage accumulation.

Microcracks initiated and propagated behaviors in Al/steel interface determined interfacial bonding strength and this was observed by in situ scanning electron microscopy (SEM) technology. Interface without or with discontinuous intermetallic compound (IMC) had low bonding strength owing to insufficient metallurgical bonding. When interface was joined with 2–3 μm serration–shaped τ5–Fe1.8Al7.2Si, largest bonding strength of 205 MPa was obtained. Microcracks initiated at protrusion of τ5–Fe1.8Al7.2Si and then propagated to τ5–Fe1.8Al7.2Si layer and τ5–Fe1.8Al7.2Si/Al interface. When interface was joined with 3–5 μm θ–Fe(Al,Si)3 + τ5–Fe1.8Al7.2Si, microcracks initiated at root of IMC layers and the interfacial bonding strength was 150 MPa. When interface was joined with 5–10 μm θ–Fe(Al,Si)3 + τ5–Fe1.8Al7.2Si, microcracks initiated and propagated along IMC layer. Lower interfacial bonding strength (106 MPa) was produced owing to large lattice mismatch between θ–Fe(Al,Si)3 and τ5–Fe1.8Al7.2Si, microdefects and higher residual stress. When interface was joined with 10 μm η–Fe2(Al,Si)5 + θ–Fe(Al,Si)3 + τ5–Fe1.8Al7.2Si, microcracks initiated and propagated along η–Fe2(Al,Si)5 layer or steel/η–Fe2(Al,Si)5 interface. Lowest bonding strength (64 MPa) was obtained resulted from pre–generated microcracks in η–Fe2(Al,Si)5 layer, largest residual stress, crystal defects and abnormal aggregation of Si.

Numerical simulations and experiments are conducted to investigate the influence of three different scan paths, namely straight, sine, and cycloid, on the flow dynamics and weld formation during the laser welding of 5A06 aluminum alloys. The cycloid scan path produced molten pools with the largest dimensions, most regular morphology, and lowest temperature gradients. And the shallowest keyhole with the highest stability and the lowest temperature is produced under this condition, which has the effect of reducing and homogenizing the distribution of the fluid velocity. The most complicated vortices are obtained when the cycloid scan path is used. Porosity ratios of 5.5, 4.9, and 0.59 are obtained when the scan paths are straight, sine, and cycloid, respectively. The large and stable molten pool, the shallow keyhole, as well as the low and highly homogeneous melt flow velocity and the complicated vortices, contribute to reduction in porosity formation.

Oscillating laser welding of 2-mm-thick 6061-T6 aluminum alloy and AISI304 steel in overlap configuration was performed under various oscillation amplitudes of 0, 3, and 5 mm. The experimental results indicated that the welding window of Al/steel dissimilar joints was improved with increasing oscillation amplitudes. The beam oscillation broadened weld width and interfacial bonding width while reducing weld depth. In the joint produced under 0-mm oscillation, a multi intermetallic compound (IMC) layer formed with a thickness of about 90 μm. In the joint produced under 3-mm oscillation, the IMC layer with the compositions of η-Fe2Al5+block-shaped θ-Fe4Al13) was obtained and its corresponding thickness reduced to 20 μm. When the oscillation amplitude further increased to 5 mm, only a η-Fe2Al5+little θ-Fe4Al13 layer with a thickness of 5 μm generated. Simulation results for the temperature history indicated that an oscillating laser beam would disperse laser energy, restraining the steel penetrating. Besides, dispersed heat energy depressed the melting of lower aluminum sheets and interfacial element diffusion. Thus, the formation of IMCs was suppressed. The limited IMCs and increased bonding width led to an improvement in the tensile–shear properties. The maximum fracture load of the joint under 5-mm oscillation was 185 N/mm, which was twice higher than that of joints welded without beam oscillation. Less Al atoms dissolved into the fusion zone under beam oscillation, resulting in lower microhardness and better toughness. Fracture locations changed from the fusion zone to the interface due to weakened steel penetration and improved toughness.

To improve the aging resistance of bioasphalt and explore the impact of organic nano calcium carbonate (CaCO3) on the aging resistance of bioasphalt, the thin-film oven test (TFOT), basic property test, rheological test, four components test, and infrared spectrum test were used to study the bioasphalt with different organic nano-CaCO3 contents. The results show that the addition of organic nano-CaCO3 increases the residual penetration, residual ductility, and residual softening point of bioasphalt. Within the range of test dosage, the greater the dosage, the more significant the effect is. With the increase of organic nano-CaCO3 content, the complex modulus aging index (GAI) of bioasphalt gradually decreases, and the colloidal instability index (IC) gradually decreases. When the content is 6%, the GAI of organic nano-CaCO3 modified bioasphalt is less than that of matrix asphalt. The nanoscale super large specific surface area of organic nano-CaCO3 has an adsorption effect on the light components in bioasphalt, which slows down the volatilization loss of light components and the oxidation process of asphalt. The addition of organic nano-CaCO3 helps to reduce the change rate of the carbonyl index and sulfoxide index.

Carbon fiber-reinforced composites are widely used in automobile, aerospace and military lightweight manufacturing due to their excellent mechanical properties such as light weight, excellent fracture resistance, corrosion resistance and wear resistance, etc. However, because of their high hardness, anisotropy and low interlayer strength characteristics, there are many problems with machine carbon fiber-reinforced composites with traditional methods. As a non-contact processing technology, laser machining technology has lots of advantages in carbon fiber-reinforced composites processing. However, there are also some defects produced in laser machining process such the heat affected zone, delamination and fiber extraction due to the great difference of physical properties between the carbon fibers and the resin matrix. To improve the quality of carbon fiber-reinforced composites laser machining, lots of works have been carried out. In this paper, the research progress of carbon fiber-reinforced composites laser machining parameters optimization and numerical simulation was summarized, the characteristics of laser cutting carbon fiber-reinforced composites and cutting quality influence factors were discussed, and the developing trend of the carbon fiber-reinforced composites laser cutting was prospected.

Direct laser welding, laser welding with Ti interlayer, and ultrasonic-assisted laser welding with Ti interlayer were used to join SiCp/6061 Al matrix composites. Microstructural evolutions, compositional distributions and tensile strengths under three processes were compared and analyzed. The experimental results showed that ultrasonic-assisted laser welding with Ti interlayer can obtain joints with good continuity and without obvious defects. Due to combined effects of Ti interlayer and ultrasonic, formation of brittle Al4C3 phase was greatly suppressed and fine TiC precipitates were also uniformly distributed in weld metal. The strength shown by the welded joints could reach up to 77.2% of the strength of the base material. Because of the internal defects (voids and pores) and the generated large numbers of brittle phases of Al4C3 in weld metal, the joint strength shown by the other two techniques, direct laser welding and laser welding with Ti interlayer, only reached 49.4 and 64.8% of the base material strength, respectively.

The carbon fiber-reinforced composite (CFRP) has the properties of a high specific strength, low density and excellent corrosion resistance; it has been widely used in aerospace and automobile lightweight manufacturing as an important material. To improve the CFRP cutting quality in the manufacturing process, a nanosecond laser with a wavelength of 532 nm was applied to cut holes with a 2-mm-thick CFRP plate by using laser rotational cutting technology. The influence of different parameters on the heat-affected zone, the cutting surface roughness and the hole taper was explored, and the cutting process parameters were optimized. With the optimized cutting parameters, the minimum value of the heat-affected zone, the cutting surface roughness and the hole taper can be obtained, which are 71.7 μm, 2.68 μm and 0.64°, respectively.

A water environmental monitoring system based on a wireless sensor network is proposed. It consists of three parts: data monitoring nodes, data base station and remote monitoring center. This system is suitable for the complex and large-scale water environment monitoring, such as for reservoirs, lakes, rivers, swamps, and shallow or deep groundwaters. This paper is devoted to the explanation and illustration for our new water environment monitoring system design. The system had successfully accomplished the online auto-monitoring of the water temperature and pH value environment of an artificial lake. The system's measurement capacity ranges from 0 to 80 °C for water temperature, with an accuracy of ±0.5 °C; from 0 to 14 on pH value, with an accuracy of ±0.05 pH units. Sensors applicable to different water quality scenarios should be installed at the nodes to meet the monitoring demands for a variety of water environments and to obtain different parameters. The monitoring system thus promises broad applicability prospects.

Abstract Background Alport syndrome (AS) is an inherited nephropathy caused by mutations in the type IV collagen genes. It is clinically characterized by damage to the eyes, ears and kidneys. Diagnosis of AS is hampered by its atypical clinical picture, particularly when the typical features, include persistent hematuria and microscopic changes in the glomerular basement membrane (GBM), are the only clinical manifestations in the patient. Methods We screened 10 families with suspected AS using whole exome sequencing (WES) and analyzed the harmfulness, conservation, and protein structure changes of mutated genes. In further, we performed in vitro functional analysis of two missense mutations in the COL4A5 gene (c.2359G > C, p.G787R and c.2605G > A, p.G869R). Results We identified 11 pathogenic variants in the type IV collagen genes (COL4A3, COL4A4 and COL4A5). These pathogenic variants include eight missense mutations, two nonsense mutations and one frameshift mutation. Notably, Family 2 had digenic mutations in the COL4A3 (p.G1170A) and UMOD genes (p.M229K). Family 3 had a digenic missense mutation (p.G997E) in COL4A3 and a frameshift mutation (p.P502L fs*151) in COL4A4. To our knowledge, four of the 11 mutations are novel mutations. In addition, we found that COL4A5 mutation relation mRNA levels were significantly decreased in HEK 293 T cell compared to control, while the cellular localization remained the same. Conclusions Our research expands the spectrum of COL4A3-5 pathogenic variants, which is helpful for clinical and scientific research.

Fabry disease, a lysosomal storage disease, is an uncommon X-linked recessive genetic disorder stemming from abnormalities in the alpha-galactosidase gene (GLA) that codes human alpha-Galactosidase A (α-Gal A). To date, over 800 GLA mutations have been found to cause Fabry disease (FD). Continued enhancement of the GLA mutation spectrum will contribute to a deeper recognition and underlying mechanisms of FD. In this study, a 27-year-old male proband exhibited a typical phenotype of Fabry disease. Subsequently, family screening for Fabry disease was conducted, and high-throughput sequencing was employed to identify the mutated gene. The three-level structure of the mutated protein was analyzed, and its subcellular localization and enzymatic activity were determined. Apoptosis was assessed in GLA mutant cell lines to confirm the functional effects. As a result, a new mutation, c.777_778del (p. Gly261Leufs*3), in the GLA gene was identified. The mutation caused a frameshift during translation and the premature appearance of a termination codon, which led to a partial deletion of the domain in C-terminal region and altered the protein’s tertiary structure. In vitro experiments revealed a significant reduction of the enzymatic activity in mutant cells. The expression was noticeably decreased at the mRNA and protein levels in mutant cell lines. Additionally, the subcellular localization of α-Gal A changed from a homogeneous distribution to punctate aggregation in the cytoplasm. GLA mutant cells exhibited significantly higher levels of apoptosis compared to wild-type cells.

Abstract Inherited anemia continues to pose a significant public health concern on a global scale, owing to its extensive geographical prevalence, substantial patient population, and profound ramifications. Here, we investigated detailed information on inherited anemias (including thalassemias, thalassemias trait, sickle cell disease, sickle cell trait, G6PD deficiency, and G6PD trait) for the period 1990–2019 from the Global Burden of Disease study. Over the course of three decades, there has been a persistent rise in the incidence of inherited anemias worldwide, culminating in a total of 44,896,026 incident cases in 2019. However, the prevalence of inherited anemias has exhibited a consistent downward trend over successive years. Significantly, these inherited anemias primarily impact females, exhibiting a male-to-female ratio of 1:1.88. Among males, the most prevalent inherited anemia is G6PD deficiency, whereas G6PD trait prevails among females. The incidence rates of inherited anemias and their temporal trend exhibited significant variations across different regions, with Central Sub-Saharan Africa displaying the highest incidence rates and Central Latin America experiencing the most substantial decline. The findings of this study suggest a significant correlation between the Socio-Demographic index (SDI) and incidence rates of inherited anemias, particularly in regions with lower SDI levels such as Africa and South Asia. These results contribute valuable insights for the analysis of global trends in the burden of inherited anemias.

Software-defined networking (SDN) faces many of the same security threats as traditional networks. The separation of the SDN control plane and data plane makes the controller more vulnerable to cyber attacks. The conventional “perimeter defense” network security model cannot prevent lateral movement attacks caused by malicious insider users or hardware and software vulnerabilities. The “zero trust architecture” has become a new security network model to protect enterprise network security. In this article, we propose an intelligent zero-trust security framework IZTSDN for the software-defined networking by integrating deep learning and zero-trust architecture, which adopts zero-trust architecture to protect every resource and network connection in the network. IZTSDN uses a traffic anomaly detection mode CALSeq2Seql based on a deep learning algorithm to analyze users’ network behavior in real-time and achieve continuous tracking and analysis of users, restrict malicious users from accessing network resources, and realize the dynamic authorization process. Finally, the Mininet simulation platform is extended to build the simulation platform MiniIZTA supporting zero-trust architecture and the proposed security framework IZTSDN is experimentally analyzed. The experimental results show that the IZTSDN security framework can provide about 80.5% of throughput when the network is attacked. The accuracy of abnormal traffic detection reaches 99.56% on the SDN dataset, which verifies that the reliability and availability of the IZTSDN security framework are verified.

The surface settlement formula of large slope tunnel is derived firstly. Then, the finite element model of shield tunnel is established by using ABAQUS software. Finally, the influences of tunnel slope, grouting pressure and shield tail clearance on ground surface settlement, and mechanical properties of surrounding rock and segments are studied by the field measurement and numerical simulation method. The results show that (1) For the slope is less than 4°, the slope increases by 1°, the settlement of ground surface increases by about 2.85 %, the shear stress of surrounding rock increases by about 4.5 kPa, and the tensile and circumferential stresses of segment increase by about 5 % and 3.1 %, respectively. (2) The proper grouting pressure is beneficial to the settlement of ground surface, and the mechanical properties of surrounding rock and segment. (3) For the shield tail clearance is less than 15 cm, the clearance increases by 1 cm, the settlement of ground surface increases by about 0.65 mm, the shear stress of surrounding rock increases by about 4.77 kPa, and the circumferential stress of segment reduces by about 0.02 MPa. Therefore, the grouting pressure with 200 kPa and the shield tail clearance with 10 cm are recommended.

Objectives The aims of the study were to assess the management of low-density lipoprotein cholesterol (LDL-C) and the goal achievement, as well as to investigate the association between baseline LDL-C level, lipid-lowering treatment (LLT), and stroke recurrence in patients with ischaemic stroke or transient ischaemic attack (TIA).Design Our study was a post hoc analysis of the Third China National Stroke Registry (CNSR-III).Setting We derived data from the CNSR-III - a nationwide clinical registry of ischaemic stroke and TIA based on 201 participating hospitals in mainland China.Participants 15,166 patients were included in this study with demographic characteristics, etiology, imaging, and biological markers from August 2015 to March 2018.Primary and secondary outcome measures The primary outcome was a new stroke, LDL-C goal (LDL-C

Background Small single subcortical infarction (SSSI) may be classified as parent artery disease-related or only branch involved according to the stenosis of parent artery. The study aimed to evaluate short-term and long-term prognoses and the effectiveness of antiplatelet therapy in SSSI.Methods We prospectively enrolled 2890 patients with SSSI from the Third China National Stroke Registry (CNSR-III) database from August 2015 to March 2018. We assessed clinical outcomes and antiplatelet treatment effects in patients with SSSI with and without parent artery stenosis (PAS) identified by magnetic resonance angiography.Results Among 2890 patients with SSSI in the perforator territory of the middle cerebral artery and the basilar artery, there were 680 (23.53%) patients with PAS and 2210 (76.47%) patients without PAS, respectively. After adjusting for potential confounders, the PAS group had a greater initial stroke severity (OR 1.262, 95% CI 1.058 to 1.505; p=0.0097) and a higher risk of ischaemic stroke recurrence at 3 months (OR 2.266, 95% CI 1.631 to 3.149; p

Compared with straight tunnels, over-excavation occurs on the inner side of the curved section during shield construction of small radius curved tunnels, and the disturbance to the ground surface and mechanical properties of surrounding rock and segment are more severe. This paper establishes the numerical models of small radius curve tunnels and straight tunnels to study the characteristics of surface deformation caused by the shield excavation of small radius curved tunnels and the influence of shield construction parameters on ground settlement, surrounding rock deformation, and segment force. The maximum error between the numerical simulation results and the measured surface settlement curve is 7.3%, which is in good agreement. The results show that: (1) The maximum value of the surface settlement of the small radius curve tunnel appears inside the curve section, and with the decrease in the curve radius, the surface settlement increases, and the distance between the peak settlement point and the tunnel center is larger. (2) When the curve radius of the tunnel is smaller, the lateral displacement of the ground surface moves farther to the inner side, and the range of soil mass with lateral displacement in the inner side is also wider. (3) Increasing the heading face pressure and grouting pressure can reduce surface settlement, but the heading face pressure should not exceed 350 kPa, and the grouting pressure should not exceed 250 kPa. (4) When the curve radius is smaller, the deformation of surrounding rock and the segment stress is larger.

A Au-stained Au nanoparticle (Aus)/pyridine (Py)/carboxylated multiwalled carbon nanotubes (C-MWCNTs)/glassy carbon electrode (GCE) was prepared for the sensitive analysis of As(III) by cast-coating of C-MWCNTs on a GCE, electroreduction of 4-cyanopyridine (cPy) to Py, adsorption of gold nanoparticles (AuNPs), and gold staining. The Py/C-MWCNTs/GCE can provide abundant active surface sites for the stable loading of AuNPs and then the AuNPs-initiated Au staining in HAuCl4 + NH2OH solution, giving a large surface area of Au on the Aus/Py/C-MWCNTs/GCE for the linear sweep anodic stripping voltammetry (LSASV) analysis of As(III). At a high potential-sweep rate of 5 V s−1, sharp two-step oxidation peaks of As(0) to As(III) and As(III) to As(V) were obtained to realize the sensitive dual-signal detection of As(III). Under optimal conditions, the ASLSV peak currents for oxidation of As(0) to As(III) and of As(III) to As(V) are linear with a concentration of As(III) from 0.01 to 8 μM with a sensitivity of 0.741 mA μM−1 and a limit of detection (LOD) of 3.3 nM (0.25 ppb) (S/N = 3), and from 0.01 to 8.0 μM with a sensitivity of 0.175 mA μM−1 and an LOD of 16.7 nM (1.20 ppb) (S/N = 3), respectively. Determination of As(III) in real water samples yielded satisfactory results.

This paper establishes a three-dimensional symmetrical shield model to investigate the influence of a double-line shield tunnel undercrossing an existing foundation pit and of changed grouting pressure on the deformation and mechanical characteristics of both the foundation pit and the tunnel itself, and it proposes a method of symmetrical segmented pressure, in which different grouting pressure is applied in different sections of the tunnel. The monitoring data are used to verify the reliability of the model, and the maximum relative error is 5.44%. The numerical results show that the maximum subsidence of the retaining pile and anchor are 3.76 mm and 10.33 mm, respectively, and the maximum tensile stress of the anchor is increased by 32.4%. The subsidence shape of the foundation pit raft is an arch with four corners warping upward and the maximum subsidence difference is 3.17 mm. Uneven subsidence of the tunnel occurs along the longitudinal direction, and large and small subsidences are located at the outside and underpart of the foundation pit, respectively, and the maximum and minimum values are 11.15 mm and 2.13 mm, respectively, and the maximum subsidence difference is 9.02 mm. The deformation and mechanical characteristics of both the foundation pit and the tunnel are significantly decreased by appropriately increasing the grouting pressure, and it is recommended that the grouting pressure should not exceed 300 kPa. The proposed method of segmented pressure can reduce the differential subsidence by 47.2% and the maximum tensile stress by 27.2%, so it can significantly reduce the uneven subsidence of the tunnel and improve the tunnel stress condition. The research results can provide a theoretical basis for the safe construction of shield tunnels under the existing foundation pit.

A water environmental monitoring system based on a wireless sensor network is proposed. It consists of three parts: data monitoring nodes, data base station and remote monitoring center. This system is suitable for the complex and large-scale water environment monitoring, such as for reservoirs, lakes, rivers, swamps, and shallow or deep groundwaters. This paper is devoted to the explanation and illustration for our new water environment monitoring system design. The system had successfully accomplished the online auto-monitoring of the water temperature and pH value environment of an artificial lake. The system's measurement capacity ranges from 0 to 80 °C for water temperature, with an accuracy of ±0.5 °C; from 0 to 14 on pH value, with an accuracy of ±0.05 pH units. Sensors applicable to different water quality scenarios should be installed at the nodes to meet the monitoring demands for a variety of water environments and to obtain different parameters. The monitoring system thus promises broad applicability prospects. [ABSTRACT FROM AUTHOR]

Here a simple and effective method was explored to fabricate M/TiO2 (M = Ag, Au) composites, which required neither pre-treatment of TiO2 nor any additives as reducing agent. Using amorphous TiO2 spheres functionalized with SH groups as starting materials, the noble metallic ions (Ag, Au) can be adsorbed by TiO2 due to their special affinity with SH groups, which is beneficial to the uniform dispersion of metallic ions on the surface of TiO2. Then the adsorbed ions were reduced to form noble metal nanoparticles by heating process (95 °C) directly without additive as reduction agent. Meanwhile, the amorphous TiO2 was transformed into anatase phase during the heating process. Thus, the transformation of TiO2 along with the reduction of noble metallic ions (Ag, Au) was simultaneously carried out by heating. The XRD patterns proved the formation of anatase TiO2 after heating. The characterizations of XPS and TEM proved the formation of Ag and Au nanoparticles on the surface of TiO2. The element mapping indicated that Ag nanoparticles are dispersed uniformly on the surface of TiO2. The photocatalytic activity of the composites has been investigated by the degradation of methyl orange under visible light irradiation. The results showed that when Ag/TiO2 (2.8 wt%) was used as photocatalyst, about 98% of the MO molecules were degraded in 70 min. [ABSTRACT FROM AUTHOR]