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Postoperative abdominal adhesion (PAA) is one of the more universal complications of abdominal surgery with a frequent incidence. Currently available keratinocyte growth factor (KGF)-based glues for the prevention of adhesions remain a great bottleneck since their long-term biological activity in vivo is insufficient. In this study, we fabricated hybrid polydopamine (PDA)-KGF nanoparticles (PDA-KGF NPs) by using an in situ self-assembly and polymerization method. The physicochemical properties of the PDA-KGF nanoparticles were systematically characterized. The effect of preventing PAA in rats was evaluated by using hybrid PDA-KGF NPs combined with hyaluronate (Ha). The expression levels of inflammatory factors and the degree of inflammatory cell infiltration in the injured peritoneum were evaluated by enzyme-linked immunosorbent assays and hematoxylin-eosin staining, respectively. The levels of phospho-Src expression were revealed by Western blotting. The degree of fibrosis and the density of deposited collagen fibers were measured with real-time reverse-transcription polymerase chain reaction and picrosirius red staining. The results indicated that the PDA-KGF NPs combined with Ha greatly prevented the incidence of abdominal adhesion s and promoted the repair of mesothelial cells in injured peritoneum. More importantly, the PDA-KGF NPs combined with Ha obviously reduced collagen deposition and fibrosis and inhibited the inflammatory response. Our results suggest that PDA-KGF NPs combined with Ha are promising barrier-like biomaterials for the effective prevention of postoperative tissue adhesion. Postoperative abdominal adhesion (PAA) as an inevitable postoperative complication affected the quality of life of patients. Currently available methods for preventing adhesions mainly employ degradable biomaterials. Previous research demonstrated that a hybrid keratinocyte growth factor (KGF)-sodium hyaluronate (Ha) gel could prevent the formation of PAAs. However, its clinical outcomes are not satisfactory since their bioactivity in vivo is too short. In this article, we fabricated hybrid polydopamine (PDA)-KGF nanoparticles (PDA-KGF NPs), which extend KGF bioactivity, effectively prevent PAA. Moreover, PDA-KGF NPs could remarkably reduce both collagen deposition and fibrosis, inhibit the inflammatory response, and promote mesothelial regeneration. Overall, the PDA-KGF NPs combined with Ha exhibit efficient antiadhesion properties, may provide a promising clinical protocol for the prevention of PAA. [Display omitted] [ABSTRACT FROM AUTHOR]

Previous research indicates that historical institutions are crucial to the functioning and development of an economy. However, little is known about whether and how a historical institution affects current entrepreneurial activities. In ancient China, the Civil-service Examination (CSE), also known as keju , was the most important institution for selecting scholar-officials and had long-lasting effects. Using the variation in the historical success in keju across prefectures, this paper empirically examines the impact of the CSE on local corporate innovation. We find that the density of jinshi , which is the highest achievement in keju , is positively correlated with the innovation productivity of local firms as measured by patent applications and citations. To determine causality, we employ an instrumental variable and a quasi-experiment in early Qing period. Further tests suggest that the CSE promotes corporate innovation by fostering a forward-looking stance in firms, enhancing firms' human capital level, and increasing local social capital. Overall, our results indicate that the CSE has a real and long-lasting impact on today's firm innovation. [ABSTRACT FROM AUTHOR]

In this paper, a robust adaptive neural control algorithm is provided to solve the problem of path-following control for underactuated surface vehicle (USV) subject to input saturation, in the presence of model uncertainties and unknown marine environmental disturbance. In the algorithm, through the application of neural network (NN), an adaptive disturbance observer (ADO) is proposed to observe the unknown disturbance, which does not need the precise information of the upper bound of the disturbance, and the model uncertainty can be appropriated simultaneously. Specially, since the ADO and control law share the same set of NN, the number of adaptive parameters of the controller can be greatly reduced. After that, dynamic surface control (DSC) method is used to avoid repeated derivative in the process of back-stepping, which solve the "calculation explosion" problem. An auxiliary system is designed to compensate errors caused by input saturation, which solve the input saturation problem of actuators. Through Lyapunov stability analysis, it is proved that all signals of the closed-loop system are semi-globally ultimately uniformly bounded (SGUUB). Finally, some experiments are conducted to demonstrate the effectiveness of the algorithm. • This paper proposes a disturbance observer-based adaptive neural control scheme for underactuated surface vehicle (USV) with the constraint of input saturation. • The neural networks are used to observe the unknown disturbance and tackle with the model uncertainty. • The minimum learning parameter (MLP) and dynamic surface control (DSC) technique are applied to release the computing memory. • The auxiliary system is designed to compensate the input saturation phenomenon. [ABSTRACT FROM AUTHOR]

Abstract In this research, a comparative study of combustion characteristics, performance and emissions of a turbocharged diesel engine fueled with diesel and methanol-Fischer-Tropsch (F-T) diesel-biodiesel-diesel blends at various simulated altitudes (0 m, 3500 m and 5500 m) were conducted. The blends were composed of diesel, methanol, F-T diesel and biodiesel at volume fractions of 65%, 15.2%, 15.6% and 4.2%, respectively. Diesel was used as the baseline fuel, methanol, F-T diesel and biodiesel were used to improve the atomization characteristics, cetane number and stability of the blends, respectively. The results indicated that the cylinder pressure, pressure rise rate and heat release rate of the engine fueled with the blends were lower than those of the diesel at an altitude of 0 m, but higher at an altitude of 5500 m. Peak torque values for the test fuels both appeared at 1400 rpm near the sea level and the speeds corresponding to the peak torque values increased with altitudes. The use of the blends improved the engine power and economic performance at low-speed ranges at an altitude of 3500 m but a dramatically reduce was observed at 5500 m. Compared with the diesel, the particulate matter (2.5 (PM 2.5)) for the blends was markedly lower, while a slightly higher in NOx at various altitudes. [ABSTRACT FROM AUTHOR]

Chemical looping CH 4 CO 2 reforming (CLDR) is an emerging technology for the generation of Fischer-Tropsch ready syngas and CO 2 utilization, which is strongly dependent upon the improvement in the design of efficient oxygen carriers (OCs). In this present work, different metal additives (Si, Zr and Ce ions) were introduced into Fe-based hexaaluminates and used OCs for CLDR. The microstructure and reactivity of BaFe 2.8 M 0.2 Al 9 O 19 (M = Fe, Si, Zr, and Ce) OCs were found greatly influenced by the metal additives and CH 4 /CO 2 redox treatment. Pure Fe and Ce doped OCs showed the co-existence of both β-Al 2 O 3 and MP hexaaluminate phases, while the introduction of Si and Zr in the hexaaluminate structure led to the phase transformation from β-Al 2 O 3 into MP. During the CH 4 /CO 2 redox process, large amounts of Fe species in both BaFe 2.8 Si 0.2 Al 9 O 19 and BaFe 2.8 Zr 0.2 Al 9 O 19 OCs were gradually stabilized in sintering FeAl 2 O 4 with low oxygen-storage capacity, which resulted in low CH 4 reactivity and weak cyclic stability. However, Ce-doped BaFe 2.8 Ce 0.2 Al 9 O 19 OC showed good reactivity and stability during the 10 redox cycles with CH 4 conversion of 93%, H 2 /CO ratio of ∼2, high syngas yield of 2.2 mmol/g, and high CO 2 activation ability of 0.95 mmol/g, which was associated with the preservation of hexaaluminate main phase, the formation of CeFe x Al 1-x O 3 and the abundant oxygen vacancies. The relationship between microstructure of BaFe 2.8 M 0.2 Al 9 O 19 hexaaluminates (M = Fe, Si, Zr, and Ce) oxygen carriers and reactivity for syngas generation and CO 2 utilization via chemical looping CH 4 CO 2 reforming was proposed. Image 1 • Pure Fe and Ce doped OCs show the co-existence of both β-Al 2 O 3 and MP. • Si and Zr doping led to the phase transformation from β-Al 2 O 3 to MP. • Large amounts of Fe species were stabilized in FeAl 2 O 4 for Si and Zr doped OCs. • CeFe x Al 1-x O 3 formed over Ce-doped hexaaluminate during the CH 4 /CO 2 redox process. • Ce-doped hexaaluminate exhibited good reactivity and cyclic stability. [ABSTRACT FROM AUTHOR]

• DIC technology is used to study the quasi-static and dynamic fracture mechanisms. • Strain concentration is the main reason for quasi-static and dynamic fracture of aluminum/steel joints. • FEM results explained the different fatigue fracture behaviors of aluminum/steel joints with reinforcement. • The weld reinforcement has an important effect on the performance and fracture behavior. • It is important to retain proper weld reinforcement of aluminum/steel joints in practical applications. The primary focus of this study was the fracture mechanism of aluminum/steel laser-arc welded-brazed joints under quasi-static tensile and dynamic fatigue conditions. Digital image correlation (DIC) was applied to record the tensile and fatigue fracture process, while finite element method (FEM) was employed to analyze stress distributions during fatigue tests. The tensile results indicated that the weld reinforcement changed the strain evolution and significantly improved mechanical properties of aluminum/steel joints. During fatigue tests, the weld reinforcement enhanced fatigue properties and changed the joint geometry of aluminum/steel joints, leading to the emergence of distinct failure behaviors. At larger stress loads, the maximum cyclic stress on the interface surpassed the interfacial bonding strength, which resulted in a gradual shift of strain concentration from the weld toe to the interface. At smaller stress loads, the interfacial region exhibited tremendous crack resistance, and strain gradually accumulated in the weld toe, which led to fatigue damage. Interestingly, the strain in the interfacial region became more significant during the fatigue process after removing the weld reinforcement. Overall, this study shed light on the fracture mechanism of aluminum/steel joints under different loading conditions. Knowledge of this mechanism is essential for developing reliable aluminum/steel structures. [ABSTRACT FROM AUTHOR]

Bromelain, a cysteine endopeptidase enzyme of great commercial value, has been widely used in food, pharmaceutical, and cosmetic industries. Conventional methods for purification of bromelain are still limited by a low binding efficiency, time-consuming process, and expensive equipment. Therefore, for selective absorption of bromelain, we developed a facile and effective method to fabricate magnetic mesoporous molecularly imprinted polymers using pericarpium granati -derived carbon as the carrier for the first time. The characterizations of the imprinted polymers indicated that a polydopamine layer was coated on the surface of the carrier and the crystallinity of the carrier did not change. The obtained imprinted polymers exhibited favourable saturation magnetization, a high adsorption capacity of 135.96 mg g −1 , a fast equilibrium time, and satisfactory reusability. The imprinted polymers were prepared by an eco-friendly method and exhibited rapid separation and good adsorption performance, thus making the method applicable to biomacromolecular separation, proteomic analysis, and biomedical research. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to identify the pathogenic mutation in a Chinese family with unexplained sudden death (USD) or occasional syncope.Materials and Methods: Whole exome sequencing and target capture sequencing were respectively conducted for two related patients. The genetic data was screened using the 1000 genomes project and SNP database (PubMed), and the identified mutations were assessed for predicted pathogenicity using the SIFT and Polyphen-2 algorithms.Results: We identified a heterozygous mutation in the RYR2 gene at c.490C>T (p.P164S), highly conserved across all species, in three family members of USD, syncope and malignant ventricular tachycardias induced by treadmill exercise test, while another heterozygous de novo mutation in SCN5A at c.5576G>A p.R1859H was detected in one family member. Both variants were verified by Sanger sequencing. Importantly, RYR2 p.P164S is associated with the risk of sudden cardiac death, such as in catecholaminergic polymorphic ventricular tachycardia.Conclusions: A pathogenic mutation in RYR2 (p.P164S) is the likely cause of USD in a Chinese family associated with malignant ventricular arrhythmias. Whole exome and target capture sequencing can be useful for discovering the genetic causes of USD. [ABSTRACT FROM AUTHOR]

• The effects of large-scale flow structures on knocking combustion under boosted high load condition were explored in a medium duty gasoline engine. • The mechanisms of inducing knocking combustion are different under swirl, inclined swirl and tumble motion conditions. • The effects of tumble ratio on knock intensity are different under swirl, inclined swirl and tumble motion conditions. • Applying an optimized inclined swirl motion based on the flat cylinder head could achieve a well tradeoff between knock and thermal efficiency under boosted high load conditions. Due to higher power density and strong swirl flow field, knock tendency is more severe in medium duty (MD) gasoline engines derived from diesel engine platforms. How to design the charge motion reasonably, so as to increase the thermal efficiency and suppress knock simultaneously needs to be further discussed in combination with the actual combustion boundary conditions. The investigations in this study focus on the charge motion roles on knock and thermal efficiency under a high load/low speed operating condition using numerical simulations. The results show that the mechanisms of inducing knocking combustion and the effects of tumble ratio (TR) on knock intensity (KI) are different under swirl, inclined swirl and tumble motion conditions. With strong swirl configurations, weaker turbulence intensity at the bottom of the combustion chamber reduces the convective heat transfer between the fresh charge and hot exhaust gas, resulting in an obvious high temperature region, and inducing the first hot spot. Increasing TR can effectively suppress knock by shortening the residence time of end gas. With inclined swirl and strong tumble configurations, the position of hot spots is determined by the asymmetrical shape of the flame front, which is induced by large-scale tumble motion around the spark plug close to TDC. The end gas reactivity is higher and the temperature distribution in the end gas region is more uniform with the increase of TR, resulting in a sharp increase in auto-ignition velocity and thus KI. Due to the suppression of knock, reduction of heat losses as well as promotion of flame speed, an optimized inclined swirl motion based on the flat cylinder head is more appropriate for MD gasoline engines. [ABSTRACT FROM AUTHOR]

6-mm 6061-T6/SUS304 butt joints were obtained successfully with a breakthrough through a deep-penetration welding-brazing process using a laser hybrid metal inert gas (MIG). The laser powers were optimized to obtain a sound joint with good formation. The quality of joints was evaluated via tensile tests. Moreover, the morphology and thickness of the intermetallic compound (IMC) layer along Al/steel interface were also studied via Scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results showed that the spreading degree on the steel side of the molten metal was improved with increasing laser power, and a sound joint without visible defects was obtained when the laser power was 4150 W. Double IMC layers consisting of η-Fe 2 (Al, Si) 5 and θ-Fe(Al, Si) 3 were formed at the three interface regions regardless of the laser power. A larger number of cracks appeared at the interface as the laser power increased to 4200 W. TEM analysis revealed that characterization and thickness of the IMC layer at the interface on the top and bottom were quite distinct. The maximum tensile strength (140.7 MPa) with reinforcement was significantly higher than that of the 6 mm Al/steel fusion welding joints using laser or laser-arc keyhole welding technology. [Display omitted] • Deep-penetration welding-brazing is employed for the joining of 6-mm Al/steel butt plates. • Double IMC layers consist of Fe 2 (Al, Si) 5 and Fe(Al, Si) 3 are formed at the three interface regions. • The characterization of the IMC layer on the top and bottom are enormously distinct. • The maximum tensile strength is higher than that of 6 mm Al/steel fusion welding joints. [ABSTRACT FROM AUTHOR]

Rigid polyurethane foams (RPFs) are a type of versatile polymers with a variety of applications, which can be produced by condensation polymerization of isocyanates with renewable polyols that are derived from biomass materials. This study investigates the characteristics of bio-sourced synthesized RPF using lignin fractionated from the alkaline black liquor of corn stover. GPC, FTIR, TGA, 2D-HSQC, and 31P NMR were used to characterize the isolated lignin specimens. The fractionated lignin specimens were then pre-polymerized followed by using them as the substitutes of RPFs. The characterization and properties of the RPFs substituted with the isolated lignins were analyzed. Compared with other lignin specimens, the specimen isolated in pH range of 5.5–2.0 afforded to higher compressive strength (0.39 ± 0.01 MPa), lower apparent density (41.35 ± 0.21 kg m-3), lower thermal conductivity (0.043 ± 0.0012 W m-1 K-1), and better thermal stability of the RPF product. In addition, the relationships between structural features of lignin specimens and the properties of the RPFs were investigated. Results show the content of β-O-4 bond inner lignin structure was the main factor that affected on the thermal conductivity of RPF, while a higher hydroxyl groups content in lignin would largely improve the compressive strength and leading to the reduction of the apparent density. This research helps to comprehensively understand the features of lignin on RPF's performance, providing a new method for its functionalization which is significant in their commercialization. • Gradient acid precipitation of lignin was performed from the black liquor. • The isolated lignins were used as bio-polyols for rigid polyurethane foam. • The relations of the functional groups in lignin on foams property were investigated. [ABSTRACT FROM AUTHOR]

• Mn, Ni, and Co ions existed as +2 valent in β-Al 2 O 3 hexaaluminate structure. • Co-doped oxygen carrier exhibited good reactivity and recyclability. • Mn doping inhibited the lattice oxygen transfer. • Ni doping significantly promoted CH 4 pyrolysis. • CO 2 regenerated BaFe 2 CoAl 9 O 19 showed the highest ratio of Fe2+/Fe3+. Chemical looping dry reforming of methane allows the continuous production of syngas and CO with decreased carbon footprint from two separated reactors, which provided system flexibility for various downstream applications, such as F-T synthesis or hydrogen purification. A key issue for this process is to find an appropriate oxygen carrier (OC) with high reactivity and recyclability. In this work, bimetallic BaFe 2 MAl 9 O 19 (M = Mn, Ni, and Co) hexaaluminates were studied as OCs, with Fe-substituted BaFe 2 Al 10 O 19 and BaFe 3 Al 9 O 19 for comparison. The influence of Mn, Ni, and Co doping on structure, redox reactivity and stability was investigated by means of XRD, XPS, BET, H 2 -TPR, CH 4 -IR, SEM, CO 2 -TPO and fixed-bed experiments. Pure Fe-substituted OCs presented the coexistence of β-Al 2 O 3 and magnetoplumbite (MP) hexaaluminate phases, which transformed from MP to β-Al 2 O 3 during cyclic CH 4 /CO 2 operation. Bimetallic BaFe 2 MAl 9 O 19 (M = Mn, Ni, and Co) only crystallized in β-Al 2 O 3 hexaaluminate due to the presence of +2 valent Mn, Ni, and Co, and the β-Al 2 O 3 structure still remained stable during the CH 4 reduction step. Mn doping inhibited the release of lattice oxygen, while Ni doping initiated significant CH 4 pyrolysis. Among all dopants, the BaFe 2 CoAl 9 O 19 OC exhibited good reactivity for syngas production with high CH 4 conversion, high syngas yield, desirable H 2 /CO ratio (~2), and stable regenerability by CO 2 , taking advantages of the enhanced oxygen-donation ability and the preservation of hexaaluminate phase during successive CH 4 /CO 2 redox cycles. [ABSTRACT FROM AUTHOR]

Chongqing is the largest megacity in southwest China and has a mountainous and humid climate. Online measurements of 96 volatile organic compound (VOC) species were performed at the three sites JYS, CJZ, and NQ, which are located in the northern, central, and southern sections of the Chongqing urban district, respectively. The measurements were performed from August to September 2015, at a time interval of 1 h. The spatiotemporal variation of VOC sources in Chongqing was characterized by combining the positive matrix factorization (PMF) model with the online measurement data. The average total VOC mixing ratios of the CJZ, NQ, and JYS sites were 41.2, 34.1, and 23.0 ppbv, respectively. The mixing ratios of tracers of incomplete combustion, exhibited obvious bimodal profiles at the CJZ and NQ sites, whereas those at the JYS site exhibited little change throughout the day. Isoprene at the three sites followed a similar pattern of average diurnal variations in mixing ratios, with minimums before sunrise and maximums at noon. The dominant sources of acetaldehyde and acetone were secondary anthropogenic source and aged air mass transport, respectively, in the city of Chongqing. Seven sources were apportioned to the results of PMF calculation using spatiotemporal VOCs composition data. The Vehicle-related sources were the largest contributor at CJZ and NQ, contributing 44% and 37% of the total VOC mixing ratios, respectively, and exhibited clear diurnal variations. Aged background air, with 68% of total VOC emissions, dominated the VOC emissions at JYS. Solvent utilization was a very important contributor at NQ and coincided with the higher levels of aromatics. O 3 formation was generally VOC-limited at NQ and CJZ, and was NO x -limited and transition region alternatively at JYS. Alkenes were important for the O 3 formation at CJZ, and both alkenes and aromatics were important for the O 3 formation at NQ. [ABSTRACT FROM AUTHOR]