Search

It is found in this paper that like the displacement-dependent fluid inerter, a diamond-shaped structure inerter can be modeled as a mem-inerter, though with an extended parasitic mem-dashpot. Fortunately, the parasitic mem-dashpot generated by the diamond-shaped structure inerter is significantly smaller than that produced by the fluid mem-inerter. This indicates its potential for wider utilization in vibration systems. A quarter-car model of the seat suspension system equipped with the mem-inerter is established by the integrated Lagrange method, and it is exhibited in simulation that the seat suspension has load adaptivity. An investigation reveals the mechanism underpinning load adaptivity of the seat suspension from the perspective of equivalence of mem-inerter, namely, a mem-inerter with different initial displacement values can be equivalent to a semi-active inerter performing an initial-position-dependent inertance control strategy. Such a mechanism of mem-inerter plays an important part in load adaptivity of the seat suspension. Finally, the comparison with three types of seat suspensions demonstrates that seat suspensions equipped with mem-inerter offer superior vibration absorption capabilities. This study provides a theoretical reference into the direct replacement of linear elements in existing seat suspensions with memory elements to enhance performance.

In this article, we investigate the control technique for a quadrotor unmanned aerial vehicle with a slung load. By taking the advantage of the cascade property, a new hierarchical control scheme is designed that divides the control problem into three parts. For the attitude motion control of the quadrotor, the nonsingularity terminal sliding mode-based control law is proposed. For the translation motion control of the quadrotor, the super-twisting-based control law is designed. In addition, for the swing attenuation of the slung load, a nonlinear antiswing control design is provided. A Lyapunov stability analysis is presented to show the stability of the closed-loop system, together with the fast convergence of the quadrotor's translational and attitude tracking, and exponential convergence of the slung load's swing motion. The real-time experiments verifies the well performance of the proposed controller.

This article proposed a new fixed-time trajectory tracking control strategy based on the disturbance observer (DOB) for a tilt trirotor unmanned aerial vehicle (TTUAV), which is subject to unknown external disturbances. To facilitate the TTUAV's trajectory tracking controller design, the dynamic model of the TTUAV is divided into two subsystems, the position subsystem (outer-loop) and the attitude subsystem (inner-loop). For the dynamics of the TTUAV's outer loop, the unknown external disturbances consist of the unknown wind disturbances, the unknown aerodynamic frictions forces, the lateral force generated by the rear servo, and the states coupling between the outer loop and the inner loop. Then, a nonlinear DOB is designed to estimate the unknown external disturbances, and a nonsingular terminal sliding-mode controller (NTSMC) is further developed to drive the TTUAV's position tracking errors to zero in a fixed time. For the dynamics of the TTUAV's inner loop, the unknown external disturbances are mainly introduced by the aerodynamic frictions torques. Then, a modified sliding mode controller is designed to reject the unknown external disturbances, and to ensure that the attitude tracking errors converge to zero exponentially. In addition, a composite stability analysis based on Lyapunov stability theory is provided to guarantee the fixed-time convergence of the closed-loop dynamics of the TTUAV. Finally, the results of the real-time experiments are presented to verify the effectiveness of the proposed control strategy.

Benzene is a typical component of volatile organic compounds (VOCs) in the iron ore sintering flue gas. The combustion behavior of benzene directly affects the emission of VOCs in iron ore sintering process. The effects of temperature, benzene, and oxygen concentrations on the conversion ratio of benzene were investigated by experiments and numerical simulation. The experiments were carried out in a tube reactor at temperatures of 773–1098 K, benzene concentrations of 0.01–0.03 vol.%, and oxygen concentrations of 10–21 vol.%. The numerical simulation was performed with the plug flow model in the CHEMKIN program based on a kinetic model that consists of 132 chemical species and 772 elementary step-like reactions. The experimental results reveal that increasing the temperature and benzene concentration could significantly promote benzene combustion. It is attributed to the increase in the reaction rates of all steps in the pathway for forming CO2and H2O. In addition, due to the large equivalent ratio of oxygen to benzene, the conversion ratio of benzene remained constant at different oxygen concentrations. The simulation results were in good agreement with the experimental results and indicated that six elementary reactions dominated the formations of CO2and H2O. The oxidations of C6H5O, CO, and C5H4O intermediates to CO2were the limiting steps in the reaction pathways.

This article focuses on the position and attitude tracking control design for an underactuated small-size unmanned helicopter. Considering the modelling uncertainties and the unknown external disturbances associated with the small-size unmanned helicopter, a new geometry-based adaptive tracking controller on special orthogonal group (SO(3)) is developed. To overcome the singularity and ambiguous issue inherented in the Euler angle expression and quaternion expression, the small-size unmanned helicopter’s dynamics is established on SO(3). Then, by using the sliding observer and radial basis function-based neural networks (RBFNNs), the helicopter’s dynamic modelling uncertainties and the unknown external disturbances are compensated. The stability of the closed-loop system is proved via the Lyapunov-based stability analysis. Moreover, the effectiveness of the proposed control strategy is verified on the self-made hardware-in-loop (HIL) testbed, and the experimental results show high position and attitude tracking accuracy of helicopter and the strong robustness to the unknown external disturbances.

Safflower (Carthamus tinctoriusL.) is a multipurpose economic crop that is distributed worldwide. Flavonoid glycosides are the main bioactive components in safflower, but only a few UDP-glycosyltransferases (UGT) have been identified. Three differentially expressed UGT genes related with the accumulation of 9 flavonoid O-glycosides were screened from metabolomics and transcriptome analysis. Safflower corolla protoplasts were used to confirm the glycosylation ability of UGT candidates in vivo for the first time. The astragalin content was significantly increased only when CtUGT3was overexpressed. CtUGT3 also showed flavonoid 3-OH and 7-OH glycosylation activities in vitro. Molecular modeling and site-directed mutagenesis revealed that G15, T136, S276, and E384 were critical catalytic residues for the glycosylation ability of CtUGT3. These results demonstrate that CtUGT3 has a flavonoid 3-OH glycosylation function and is involved in the biosynthesis of astragalin in safflower. This study provides a reference for flavonoid biosynthesis genes research in nonmodel plants.

A commercially available and versatile dehydrative amidation catalyst, featuring a thianthrene boron acid structure, has been developed. The catalyst shows high catalytic activity to both aliphatic and less reactive aromatic carboxylic acid substrates, including several bioactive or clinical molecules with a carboxylic acid group.

Safflower, an economic crop, is renowned for its flowers, which are widely used in medicines for treating cardiovascular and cerebrovascular diseases and in dyes for food and industry. The utility of safflower depends on its flavonoid glycosides. Therefore, the biosynthesis of safflower flavonoid glycosides has been a focus of attention, but the present mechanisms remain poorly understood. This study aims to identify functional genes associated with flavonoid glycoside biosynthesis in safflower through a comprehensive approach that integrates whole-genome screen and multi-omics correlation studies. CYP and UGT are two crucial genes families involved in flavonoid glycoside biosynthesis. We have screened 264 CYP genes and 140 UGT genes in the genome of safflower and conducted analyzes including phylogenetic relationships, conserved motifs, gene structures, cis-acting elements, and chromosome mapping, which provided extensive and comprehensive data on the CYP and UGT gene families. Integration of phenotype and metabolic data from safflower different tissues helped narrow down the screening by confirming that HSYA is synthesized only in flowers. Based on the gene expression patterns and phylogenetic analysis, CtOGT1was ultimately identified, which could catalyze the generation of glycosides using various flavonoid substrates and exhibited strong substrate affinity. Moreover, molecular docking studies elucidated CtOGT1’s highly active intrinsic mechanism. In conclusion, this study effectively identified genes responsible for flavonoid glycoside biosynthesis in safflower through the integration of whole-genome screen and multi-omics analysis, established a comprehensive foundation of data, methodology, and experimental evidence for further elucidating the pathways of safflower flavonoid glycoside biosynthesis.

Safflower (Carthamus tincoriusL.) is an economically important plant. Flowers are a source of dyes and active ingredients in medicines. The development of flower-specific promoters is of great significance for the directed regulation of the biosynthesis of targeted products. However, few flower-specific promoters have been reported in safflower. In this study, transcriptome analysis of various safflower tissues was performed. A total of 40.37 Gb of clean data were obtained, and 100 safflower-specific genes were screened. Three genes (CtFSG1, CtFSG2and CtFSG3) were identified by RT–PCR, and all had high expression in flowers. The promoters of the three genes (pCtFSG1, pCtFSG2and pCtFSG3) were cloned, and the promoter sequences were analysed. Promoter activity analysis showed that pCtFSG2had suitable promoter activity in protoplasts of tubiform floret in safflower. This promoter specificity was further characterized by Agrobacterium-mediated transformation of pCtFSG2::GUSto Arabidopsis thaliana. The results showed that GUS staining was detectable only in flowers. Moreover, deletion analysis of the pCtFSG2promoter region revealed that the DNA segments from − 1953 to − 1534 and − 980 to − 490 are critical for the expression of pCtFSG2. Our results indicated that pCtFSG2is a flower-specific promoter with suitable promoter activity in safflower, which has potential value for directional modification of safflower.

This article presents a novel adaptive controller for a small-size unmanned helicopter using the reinforcement learning (RL) control methodology. The helicopter is subject to system uncertainties and unknown external disturbances. The dynamic unmodeling uncertainties of the system are estimated online by the actor network, and the tracking performance function is optimized via the critic network. The estimation error of the actor-critic network and the external unknown disturbances are compensated via the nonlinear robust component based on the sliding mode control method. The stability of the closed-loop system and the asymptotic convergence of the attitude tracking error are proved via the Lyapunov-based stability analysis. Finally, real-time experiments are performed on a helicopter control testbed. The experimental results show that the proposed controller achieves good control performance.

Background and aims: Currently, published data of endoscopic resection (ER) for giant (≥ 6 cm) gastric subepithelial tumors originating from the muscularis propria layer (MP-SETs) are extremely rare and limited to only case reports. The aim of this study was thus to assess the feasibility of using ER for giant (≥ 6 cm) gastric MP-SETs in a case series. Methods: Between July 2013 and December 2020, a total of 23 patients with giant (≥ 6 cm) gastric MP-SETs were treated with ER in the endoscopic center of Taizhou hospital. The study assessed outcomes of en bloc resection, complete resection, total complications, and local residual/recurrence of tumors. Results: The mean procedure time was 112.2 min. En bloc resection was achieved in 22 tumors (95.7%). En bloc removal from the stomach and complete resection were achieved in 6 patients (26.1%). The rate of complete resection differed significantly depending on the minimum tumor diameter (P< 0.001). During hospitalization, 4 patients had complications, including localized peritonitis (3/23, 13.0%) and pulmonary infection (1/23, 4.3%). These 4 patients recovered successfully after conservative medical treatment. Histopathological examination revealed that 18 tumors were gastrointestinal stromal tumors (GISTs), and 5 tumors were leiomyoma. No patients were observed to have residual or recurrent tumors during the follow-up. Conclusions: Although ER for giant (≥ 6 cm) gastric MP-SETs was associated with several technical challenges and a relatively low complete resection rate, this technique was found to be a feasible therapeutic method for selected patients with a giant (≥ 6 cm) gastric MP-SETs when performed by an experienced endoscopic team.

Background: With the increasing realization of the importance of gallbladder function, choledochoscopic gallbladder-preserving surgery has been advocated for benign gallbladder diseases. However, limited information is available regarding the use of endoscopic gallbladder-preserving surgery (EGPS) for patients with benign gallbladder diseases. The aim of this study was to evaluate the feasibility of EGPS for benign gallbladder diseases. Methods: Between June 2020 and January 2021, 22 patients with gallbladder stones and/or gallbladder polyps were treated with EGPS. The main outcome measures included the rate of complications, residual gallbladder stones, and gallbladder stone recurrence. Results: In this study, transgastric EGPS was successfully performed in 22 patients (13 female, 9 male) with benign gallbladder diseases, and included 8 cases of multiple gallstones, 4 cases of gallbladder polyps with gallstones, 6 cases of multiple gallbladder polyps, 2 cases of single gallstone, and 2 case of singe gallbladder polyp. The median time of transgastric EGPS was 118 min. During hospitalization, 4 patients suffered localized peritonitis (4/22, 18.2%), and these patients successfully recovered after conservative medical treatment. None of the patients experienced massive bleeding, delayed bleeding, diffuse peritonitis, or any other serious complications. During the median follow-up of 4 months, 1 patient suffered residual gallstone, while no gallstone recurrence or deaths related to transgastric EGPS occurred in any patients. Conclusions: Transgastric EGPS appears to be a feasible treatment method in selected patients with benign gallbladder diseases. However, as it is a new technique, further studies are needed to explore the long-term effectiveness of transgastric EGPS.

Sugar transporters are essential for osmotic process regulation, various signaling pathways and plant growth and development. Currently, few studies are available on the function of sugar transporters in sorghum (Sorghum bicolorL.). In this study, we performed a genome-wide survey of sugar transporters in sorghum. In total, 98 sorghum sugar transporters (SSTs) were identified viaBLASTP. These SSTs were classified into three families based on the phylogenetic and conserved domain analysis, including six sucrose transporters (SUTs), 23 sugars will eventually be exported transporters (SWEETs), and 69 monosaccharide transporters (MSTs). The sorghum MSTs were further divided into seven subfamilies, including 24 STPs, 23 PLTs, two VGTs, four INTs, three pGlcT/SBG1s, five TMTs, and eight ERDs. Chromosomal localization of the SST genes showed that they were randomly distributed on 10 chromosomes, and substantial clustering was evident on the specific chromosomes. Twenty-seven SST genes from the families of SWEET, ERD, STP, and PLT were found to cluster in eight tandem repeat event regions. In total, 22 SSTs comprising 11 paralogous pairs and accounting for 22.4% of all the genes were located on the duplicated blocks. The different subfamilies of SST proteins possessed the same conserved domain, but there were some differences in features of the motif and transmembrane helices (TMH). The publicly-accessible RNA-sequencing data and real-time PCR revealed that the SST genes exhibited distinctive tissue specific patterns. Functional studies showed that seven SSTs were mainly located on the cell membrane and membrane organelles, and 14 of the SSTs could transport different types of monosaccharides in yeast. These findings will help us to further elucidate their roles in the sorghum sugar transport and sugar signaling pathways.

Ultrafast laser-induced phase/structural transitions show a great potential in optical memory and optical computing technologies, which are believed to have advantages of ultrafast speed, low power consumption, less heat diffusion and remote control as compared with electronic devices. Here, we review and discuss the principles of orbital-selective electronic excitation and its roles in phase/structural transitions of phase-change memory (PCM) materials, including Sc0.2Sb1.8Te3and GeTe phases. It is demonstrated, that the mechanism can influence the dynamics or results of structural transitions, such as an ultrafast amorphization of Sc0.2Sb1.8Te3and a non-volatile order-to-order structural transition of GeTe. Without thermal melting, these structural transitions have the advantages of ultrafast speed and low power consumption. It suggests that the orbital-selective electronic excitation can play a significant role in discovering new physics of phase change and shows a potential for new applications.

Flavor substances are crucial to the quality of soy sauce and closely related to the intermediate metabolites. This study systematically explored the dynamic changes in physicochemical characteristics, metabolomics and flavoromics during traditional Chinese soy sauce fermentation. The results indicated that the amino acid nitrogen gradually increased to 0.95 g/100 mL on the 13th day and then stabilized, and the changes of reducing sugars increased to 66.40 mg/mL on the 7th day and then slowly decreased. A total of 90 volatile compounds and 1172 non-volatile metabolites were detected. In the early fermentation period (1–7 day), alcohols, aldehydes and ketones were the main volatile compounds, but as fermentation proceeded, phenols and esters gradually accumulated. The total content of volatile compounds, mainly alcohols and phenols, reached the highest value on the 23rd day. Non-volatile metabolites were mainly amino acids, organic acids, lipids and carbohydrates, and the content and types of varied with fermentation time. KEGG analysis indicates there were significant changes in the proline and arginine metabolism in the middle and late periods (7–28 day) compared to the early fermentation period. Correlation analysis indicating a delicate balance between the transformation of metabolites and the formation of volatile compounds in traditional Chinese soy sauce.

Friction stir welding (FSW) is a relatively new welding technology. Although FSW technology has been widely used in many industries, there is a lack of effective online detection method of process parameters. Weld temperature and tool positioning are two key parameters in the study of process parameters. To realize online measurement of weld temperature and tool positioning in FSW, a measurement method of weld temperature and tool positioning is proposed by designing a new online detection device in FSW. The weld temperature measurement is realized by the material emissivity model based on the principle of infrared temperature measurement. Based on the principle of trigonometric distance measurement, the tool positioning is measured by data processing algorithm. In order to verify the feasibility of the measurement method, the welding processes of aluminum alloy with two thicknesses are detected online. The results show that the weld temperature measurement accuracy of the online detection device is within ± 2%. The measurement of tool positioning is realized. This measurement method proposed in this paper can be applied to the optimization of process design and temperature feedback control.

Tab engineering enables electrons transferred quickly for significantly increased output current of flexible pouch cell with desirable power and energy density has been demonstrated for practical applications.

Safety of youth outdoor education has been the focus of attention of parents, school and society. Based on the theory of safety engineering and structural elements of outdoor education practice, the author establishes the first-level indicators influencing the safety of youth outdoor education, which include the educators, educatees, education environment, education influence and social security. On the basis of experience pre-selection, experimental pre-selection and consultation with experts, the Safety Influencing Factors Index System for Youth Outdoor Education is established after three rounds of expert consultation, screening and scoring, and the weight of the first-level and second-level indicators is assigned. The system covers 5 first-level indicators, 30 second-level indicators, and 103 third-level indicators. The index system is expected to provide data support for government authorities to formulate safety policies and for outdoor education institutions to formulate safety rules and regulations, and provide a basis for teachers to propose targeted measures to ensure the safety of outdoor education and conduct safety education in practice. [ABSTRACT FROM AUTHOR]

The ceaseless increase of pollution cases due to the tremendous consumption of fossil fuels has steered the world towards an environmental crisis and necessitated urgency to curtail noxious sulfur oxide emissions. Since the world is moving toward green chemistry, a fuel desulfurization process driven by clean technology is of paramount significance in the field of environmental remediation. Among the novel desulfurization techniques, the oxidative desulfurization (ODS) process has been intensively studied and is highlighted as the rising star to effectuate sulfur-free fuels due to its mild reaction conditions and remarkable desulfurization performances in the past decade. This critical review emphasizes the latest advances in thermal catalytic ODS and photocatalytic ODS related to the design and synthesis routes of myriad materials. This encompasses the engineering of metal oxides, ionic liquids, deep eutectic solvents, polyoxometalates, metal–organic frameworks, metal-free materials and their hybrids in the customization of advantageous properties in terms of morphology, topography, composition and electronic states. The essential connection between catalyst characteristics and performances in ODS will be critically discussed along with corresponding reaction mechanisms to provide thorough insight for shaping future research directions. The impacts of oxidant type, solvent type, temperature and other pivotal factors on the effectiveness of ODS are outlined. Finally, a summary of confronted challenges and future outlooks in the journey to ODS application is presented.

ABSTRACTPurposeTo estimate influenza-associated excess mortality rates (EMRs) in Chongqing from 2012 to 2018.MethodsWe obtained weekly mortality data for all-cause and four underlying causes of death (circulatory and respiratory disease (CRD), pneumonia and influenza (P&I), chronic obstructive pulmonary disease (COPD) and ischemic heart disease (IDH)), and influenza surveillance data, from 2012 to 2018. A negative-binomial regression model was used to estimate influenza-associated EMRs in two age groups (<65 years and ≥65 years).ResultsIt was estimated that an annual average of 10025 influenza-associated deaths occurred in Chongqing, corresponding to 5.2% of all deaths. The average EMR for all-cause death associated with influenza was 33.5 (95% confidence interval (CI): 31.5–35.6) per 100 000 persons, and in separate cause-specific models we attributed 24.7 (95% CI: 23.3–26.0), 0.8 (95% CI: 0.7–0.8), 8.5 (95% CI: 8.1–9.0) and 5.0 (95% CI: 4.7–5.3) per 100 000 persons EMRs to CRD, P&I, COPD and IDH, respectively. The estimated EMR for influenza B virus was 20.6 (95% CI: 20.3–21.0), which was significantly higher than the rates of 5.3 (95% CI: 4.5–6.1) and 7.5 (95% CI: 6.7–8.3) for A(H3N2) and A(H1N1) pdm09 virus, respectively. The estimated EMR was 152.3 (95% CI: 136.1–168.4) for people aged ≥65 years, which was significantly higher than the rate for those aged <65 years (6.8, 95% CI: 6.3–7.2).ConclusionsInfluenza was associated with substantial EMRs in Chongqing, especially among elderly people. Influenza B virus caused a relatively higher excess mortality impact compared with A(H1N1)pdm09 and A(H3N2). It is advisable to optimize future seasonal influenza vaccine reimbursement policy in Chongqing to curb disease burden.

Endoscopy is the primary modality for detecting asymptomatic esophageal squamous cell carcinoma (ESCC) and precancerous lesions. Improving detection rate remains challenging. We developed a system based on deep convolutional neural networks (CNNs) for detecting esophageal cancer and precancerous lesions [high-risk esophageal lesions (HrELs)] and validated its efficacy in improving HrEL detection rate in clinical practice (trial registration ChiCTR2100044126 at www.chictr.org.cn). Between April 2021 and March 2022, 3117 patients ≥50 years old were consecutively recruited from Taizhou Hospital, Zhejiang Province, and randomly assigned 1:1 to an experimental group (CNN-assisted endoscopy) or a control group (unassisted endoscopy) based on block randomization. The primary endpoint was the HrEL detection rate. In the intention-to-treat population, the HrEL detection rate [28 of 1556 (1.8%)] was significantly higher in the experimental group than in the control group [14 of 1561 (0.9%), P= 0.029], and the experimental group detection rate was twice that of the control group. Similar findings were observed between the experimental and control groups [28 of 1524 (1.9%) versus 13 of 1534 (0.9%), respectively; P= 0.021]. The system’s sensitivity, specificity, and accuracy for detecting HrELs were 89.7, 98.5, and 98.2%, respectively. No adverse events occurred. The proposed system thus improved HrEL detection rate during endoscopy and was safe. Deep learning assistance may enhance early diagnosis and treatment of esophageal cancer and may become a useful tool for esophageal cancer screening.

BACKGROUND:KRAS gene mutations are well known as a key driver of advanced non–small cell lung cancer (NSCLC). The impact of KRAS-mutant subtypes on the survival benefit from salvage chemotherapy is controversial. Here, we present a real-world study in patients across China with advanced NSCLC with KRAS mutations using a website-based patient self-report system. METHODS:We identified a total of 75 patients diagnosed with KRAS-mutant (determined by molecular sequencing) advanced NSCLC between 2014/5/9 and 2019/5/30. KRAS mutation subtypes were divided into G12C and non-G12C groups for statistical analysis. The clinicopathological characteristics and treatment survival benefit in all patients with a KRAS mutation were evaluated. Programmed death-ligand 1 (PD-L1) expression data were collected from 30 patients in the same cohort. RESULTS:In this study, 23 patients with stage IIIB NSCLC and 52 patients with stage IV NSCLC were enrolled with 58 men and 17 women; the median age was 60 years (39–84). All patients received regular chemotherapy/radiotherapy/targeted therapy/immune therapy as per the disease condition. Four main KRAS mutation subtypes were detected: G12C (33%), G12V (19%), G12A (12%), and G12D (12%). Three predominant KRAS comutations were detected: TP53-KRAS (31%), EGFR-KRAS (11%), and STK11-KRAS (8%). Compared with the KRAS non-G12C mutation subtype, patients with the KRAS G12C mutation had potentially longer progression-free survival (PFS) after first-line chemotherapy (4.7 vs.2.5 months, p < 0.05). Pemetrexed-based chemotherapy appeared to be superior to taxanes- and gemcitabine-based chemotherapies in all patients (PFS: 5.0 vs. 1.5 and 2.3 months, respectively, p > 0.05). Cox regression analysis showed that the KRAS G12C mutation and pemetrexed-based first-line chemotherapy were positive influencers for PFS after first-line (hazard ratios = 0.31 and 0.55, respectively, P < 0.05), but not second-line chemotherapies. CONCLUSION:The KRAS G12C mutation could be a predictive biomarker for better survival benefit from first-line chemotherapy in patients with advanced NSCLC and KRAS mutations. The first-line chemotherapy regimen could possibly influence the outcome in patients with KRAS mutations. Larger and prospective clinical trials are warranted to confirm our conclusions.

An effect of Cl−concentration on the stress corrosion cracking (SCC) behavior of 13Cr stainless steel was investigated by employing electrochemical measurements and the slow strain rate tensile tests. These tests were conducted in various solutions with different concentrations of NaCl at 90 °C under 3 MPa CO2with 3 MPa N2. The results indicate that the passive film of the specimen formed in the 10% NaCl solution has the best protective effect on the matrix. The SCC susceptibility does not increase with increasing the chloride ion concentration, the lowest SCC susceptibility occurs when the NaCl concentration is 10%, and the specimens show higher SCC susceptibility in the 5% NaCl and 20% NaCl solutions.

Declining estrogen production in postmenopausal females causes osteoporosis in which the resorption of bone exceeds the increase in bone formation. Although clinical drugs are currently available for the treatment of osteoporosis, sustained medication use is accompanied by serious side effects. Corydalis bungeanaHerba, a famous traditional Chinese herb listed in the Chinese Pharmacopoeia Commission, constitutes various traditional Chinese Medicine prescriptions, which date back to thousands of years. One of the primary active components of C. bungeanaTurcz. is Corynoline (Cor), a plant isoquinoline alkaloid derived from the Corydalisspecies, which possesses bone metabolism disease therapeutic potential. The study aimed at exploring the effects as well as mechanisms of Cor on osteoclast formation and bone resorption. TRAcP staining, F-actin belt formation, and pit formation were employed for assessing the osteoclast function. Western blot, qPCR, network pharmacology, and docking analyses were used for analyzing the expression of osteoclast-associated genes and related signaling pathways. The study focused on investigating how Cor affected OVX-induced trabecular bone loss by using a mouse model. Cor could weaken osteoclast formation and function by affecting the biological receptor activators of NF-κB and its ligand at various concentrations. Mechanistically, Cor inhibited the NF-κB activation, and the MAPKs pathway stimulated by RANKL. Besides, Cor enhanced the protein stability of the Nrf2, which effectively abolished the RANKL-stimulated ROS generation. According to an OVX mouse model, Cor functions in restoring bone mass, improving microarchitecture, and reducing the ROS levels in the distal femurs, which corroborated with its in vitro antiosteoclastogenic effect. The present study indicates that Cor may restrain osteoclast formation and bone loss by modulating NF-κB/MAPKs and Nrf2 signaling pathways. Cor was shown to be a potential drug candidate that can be utilized for the treatment of osteoporosis.

Chemical recycling to monomers (CRM) offers a promising closed-loop approach to transition from current linear plastic economy toward a more sustainable circular paradigm. Typically, this approach has focused on modulating the ceiling temperature (Tc) of monomers. Despite considerable advancements, polymers with low Tcoften face challenges such as inadequate thermal stability, exemplified by poly(γ-butyrolactone) (PGBL) with a decomposition temperature of ∼200 °C. In contrast, floor temperature (Tf)-regulated polymers, particularly those synthesized via the ring-opening polymerization (ROP) of macrolactones, inherently exhibit enhanced thermodynamic stability as the temperature increases. However, the development of those Tfregulated chemically recyclable polymers remains relatively underexplored. In this context, by judicious design and efficient synthesis of a biobased macrocyclic diester monomer (HOD), we developed a type of Tf-regulated closed-loop chemically recyclable poly(ketal-ester) (PHOD). First, the entropy-driven ROP of HOD generated high-molar mass PHOD with exceptional thermal stability with a Td,5%reaching up to 353 °C. Notably, it maintains a high Td,5%of 345 °C even without removing the polymerization catalyst. This contrasts markedly with PGBL, which spontaneously depolymerizes back to the monomer above its Tcin the presence of catalyst. Second, PHOD displays outstanding closed-loop chemical recyclability at room temperature within just 1 min with tBuOK. Finally, copolymerization of pentadecanolide (PDL) with HOD generated high-performance copolymers (PHOD-co-PPDL) with tunable mechanical properties and chemical recyclability of both components.

In this paper, the electronic structure in armchair graphene nanoribbons (AGNRs) and graphene nanoribbons doped B at the edge (B-AGNRs) are obtained based on the first principle theory. It shows that the band gap has the oscillation characteristic whose period is 3. The band gap oscillating characteristic gradually vanishes and tends to be stable after doping B at graphene nanoribbons edge. This provides a theoretical guidance for developing the stable graphene nanodevices.

The electronic structure and optical properties of GaP were calculated using generalized gradients in density functional theory. The Bonn effective charge, optical frequency dielectric constant and the LO-TO splitting value were calculated by density functional theory perturbation method.

The Craig-Bampton modal synthesis method was used to establish the dynamic model of marine four-stroke diesel engine body and crankshaft. Based on the Greenwood/Tripp microlong contact theory considering the surface roughness and the generalized Reynolds equation considering the oil filling rate, the elastohydrodynamic lubrication model of the main bearing of the four - stroke diesel engine is found. At the rated speed, the lubrication performance of the main bearing is simulated and analyzed by the maximum dynamic pressure, the minimum oil film thickness and the friction power. The results show that the oil pressure of 4 # main bearing is the largest and the maximum oil film pressure is in the 4 # main bearing position. The friction load of 4 # main bearing is the largest. The average oil film thickness of 4 # main bearing is the smallest and the minimum oil film The thickness also occurred in the 4 # main bearing position; it can be seen 4 # bearing the most bad lubrication conditions.

In this paper, the control problem for a quadrotor helicopter which is subjected to modeling uncertainties and unknown external disturbance is investigated. A new nonlinear robust control strategy is proposed. First, a nonlinear complementary filter is developed to fuse the raw data from the onboard barometer and the accelerometer to decrease the negative effects from the noise associated with the low-cost onboard sensors Then the adaptive super-twisting methodology is combined with a backstepping method to formulate the nonlinear robust controller for the quadrotor’s attitude angles and the altitude position. Lyapunov based stability analysis shows that finite time convergence is ensured for the closed-loop operation of the quadrotor’s roll angle, pitch angle, row angle and the altitude position. Real-time flight experimental results, which are performed on a quadrotor flight testbed, are included to demonstrate the good control performance of the proposed control methodology.

In order to improve the driving safety of vehicles, a non-pneumatic safety tire named mechanical elastic wheel was developed, and the structural components of mechanical elastic wheel and the method of determining the rubber material parameters of Mooney-Rivlin model were introduced. Uniaxial tensile tests of the rubber in different parts of mechanical elastic wheel were carried out with a stretch test machine and the material parameters and of the Mooney-Rivlin model were determined by fitting the experimental data. Finite element method (FEM) was used to validate the stability of the fitted data. The results show that the obtained material parameters have high accuracy and can be a reference for the subsequent finite element simulation of mechanical elastic wheel.

Background This study aimed to evaluate the correlation between neutrophil to lymphocyte ratio (NLR) with overall survival (OS) of esophageal squamous cell carcinoma (ESCC) patients.Method Records of patients with diagnosed ESCC were reviewed. Leukocyte counts and patients' characteristics were extracted from their clinical records to calculate NLR. Correlation between NLR and baseline characteristics with overall survival (OS) was then analyzed using Cox regression. The patients were then separated into higher and lower NLR groups according to median NLR. OS was further compared between the 2 groups.Results A total of 1281 patients were included in the study. Cox regression analysis showed a significant correlation of NLR with OS of ESCC patients. The median pretreatment NLR was identified as 2.86. Higher NLR was associated with worse prognosis in terms of OS.Conclusions Pretreatment NLR is independently associated with OS of ESCC patients. Therefore, NLR may be used as a predictive indicator for pretreatment evaluation and adjustment of treatment regimen.

Conventional oil based drilling fluids or muds (OBMs) using organophilic clay as viscosifier and rheological control agent cannot carry drill cuttings and suspend weighting materials effectively in oil well drilling process. It also causes excessive viscosity of drilling fluids, which lowers the rate of penetration. For the sake of solving these problems, in this study, hydrogen bonds-enhanced organoclay-free oil based drilling fluid was proposed. Firstly key additives (emulsifier, filter reducer) for OBMs with highly electronegative groups that might form hydrogen bonds were synthesized. In addition, a hydrogen bonding linker was synthesized and used to connect other additives to form a hydrogen bonding network in OBMs. The properties of drilling fluids were characterized by rheological measurements, static filtration experiments and plugging experiments. Experimental results show that, compared with the conventional OBM, the hydrogen bonds-enhanced organoclay-free OBMs substantially increased yield point (YP) and gel strengths, reduced filtration loss and exhibited a better plugging ability on high-permeability sand cores. Besides, a higher stability was also observed.

Endoscopic removal of a duodenal lesion is still considered to be a challenging procedure that can be fraught with potentially serious complications, specifically perforation or delayed bleeding. This study was to assess the safety of endoscopic resection for duodenal subepithelial lesions (SELs) with wound closure using clips and an endoloop. From October 2010 to July 2015, a total of 68 consecutive patients with duodenal SELs were treated with endoscopic resection with wound closure using clips and an endoloop. The main outcome measures considered were the incidence of complete resection, perioperative perforation, delayed perforation, delayed bleeding, residual lesions, and lesion recurrence. Complete resection was successfully achieved for all 68 patients. The median lesion size was 1.7 cm. The median procedure time was 62 min. The mean hospital stay was 5.5 days. During the procedure, five patients developed perioperative perforations (7.4 %) and no patients developed delayed bleeding, delayed perforation, or other serious complications. The five patients with perioperative perforations recovered after conservative treatment. The perioperative perforation rate was significantly higher for lesions originating in the muscularis propria layer (18.2 %) than in the submucosal layer (2.2 %; p< 0.05). No residual or recurrent lesions were detected during the follow-up period (median: 27 months). Endoscopic resection with wound closure using clips and an endoloop is an effective and reasonably safe therapeutic method for treating/removing duodenal SELs when managed by an experienced endoscopic team, and it can provide an alternative treatment option for patients with duodenal SELs.