A novel auxiliary fixation technique of meshes in intraperitoneal onlay mesh procedures for incisional hernia repair

IntroductionMesh fixation is an important step in incisional hernia repair. Weak fixation possibly results in postoperative pain, and even hernia recurrence. We innovated an auxiliary fixation approach, the magnet attraction technique (MAT), to achieve better mesh fixation. The purpose of this study was to evaluate the effect of MAT in intraperitoneal onlay mesh (IPOM) procedures for incisional hernia repair.MethodsHistorical patient records were analyzed according to the clinical data of 16 patients with incisional hernias. Among them, 5 patients have undergone IPOM repair procedures in combination with MAT to assist in mesh fixation. As a control, 11 patients treated with IPOM and mesh fixation via conventional suspension were included. The clinical data collected include patients' basic characteristics, intraoperative and postoperative conditions, and follow-up results in both groups.ResultsCompared with patients in the control group, patients in the MAT group were found to suffer from a larger hernia ring diameter and longer surgical duration, but shorter hospitalization length on average. And most importantly, no complication has been reported in the MAT group.ConclusionMAT in IPOM operation was regarded as a feasible and safe technique for patients suffering from incisional hernias

Neurochemical Mechanism of Electroacupuncture: Anti-injury Effect on Cerebral Function after Focal Cerebral Ischemia in Rats†

We explored the neurochemical mechanism of electroacupuncture's (EA) protective effect on brain function in focal cerebral ischemia rats, using cerebral ischemia/reperfusion rats established by the middle cerebral artery occlusion (MCAO) method. Adult male Sprague–Dawley rats were randomly divided into four groups: Sham, Sham+EA, MCAO and MCAO+EA. The rats in Sham+EA and MCAO+EA were accepted EA treatment at ‘GV26’ and ‘GV20’ acupoints for 30 min. Electric stimulation was produced by a G-6805 generator and neurological deficit scores were recorded. Mitochondria respiratory function and the activities of respiratory enzymes were measured by a computer-aided Clark oxygen electrode system. Results showed that EA treatment might reduce the neurological deficit score, and significantly improve respiratory control ratio (RCR), the index of mitochondrial respiratory function, and increase the activities of succinic dehydrogenase, NADH dehydrogenase and cytochrome C oxidase in the MCAO rats. Results suggest that EA might markedly decrease the neurological deficit score, promote the activities of respiratory enzymes and reduce the generation of reactive oxygen species (ROS), resulting in improvement of respiratory chain function and anti-oxidative capability of brain tissues in the infarct penumbra zone. This be a mechanism of EA's anti-injury effect on brain function in MCAO rats

Microstructure and properties of spot welded joints of hot-stamped ultra-high strength steel used for automotive body structures

Hot-stamped ultra-high strength steels have been widely used in automobile structural parts. Considering the high splash tendency in resistance spot welding due to their extremely high hardness, in this work, microstructural characteristics and mechanical performance of the resistance spot welded ultra-high strength steels are investigated. The results indicate that the interface between the nugget and heat-affected zone (HAZ) is the weakest zone where fractures initiate. In tensile shearing tests, a qualified spot welding joint failed with a button-shaped fracture. Welding defects would significantly decrease the load-carrying capacity and lead to interfacial fracture, except for a button-shaped fracture. In spot welding, it was found that a specific mid-frequency alternating current (AC) input mode, in which a 6 ms cooling cycle was inserted between every two neighboring current pulses, can avoid the splash in the spot welding of hot-stamped hardened steels

Microstructure and Properties of Spot Welded Joints of Hot-Stamped Ultra-High Strength Steel Used for Automotive Body Structures

Hot-stamped ultra-high strength steels have been widely used in automobile structural parts. Considering the high splash tendency in resistance spot welding due to their extremely high hardness, in this work, microstructural characteristics and mechanical performance of the resistance spot welded ultra-high strength steels are investigated. The results indicate that the interface between the nugget and heat-affected zone (HAZ) is the weakest zone where fractures initiate. In tensile shearing tests, a qualified spot welding joint failed with a button-shaped fracture. Welding defects would significantly decrease the load-carrying capacity and lead to interfacial fracture, except for a button-shaped fracture. In spot welding, it was found that a specific mid-frequency alternating current (AC) input mode, in which a 6 ms cooling cycle was inserted between every two neighboring current pulses, can avoid the splash in the spot welding of hot-stamped hardened steels

Species Diversity of Deadwood in Chinese Fir Plantations Differs between Mixed Planting and Thinning Treatments

The occurrence of deadwood is inevitable during the process of plantation conversion, but the influences of conversion and the potential environmental effect on deadwood species diversity remain unclear. We established two fixed plots in Chinese fir thinned forest (TF) and Chinese fir and Michelia macclurei Dandy mixed forest (MF) (100 × 80 and 120 × 60 m2, respectively). We classified the deadwood into groups based on origin and by status, and analyzed deadwood species diversity using four common diversity indices. We also investigated the contribution of topographic factors to tree mortality using redundancy analysis. The species composition of deadwood differed markedly between the MF and TF. The species diversity and variety of deadwood status were greater for the TF than MF, although abundance was lower. Topography was poorly correlated with deadwood in the MF, while in the TF, altitude was strongly correlated with deadwood from Chinese fir, shade-intolerant late-coming populations, and fallen wood. Slope was negatively correlated with late-coming populations and fallen wood, but deadwood correlations with convexity were weak. These results indicate that cultivation methods strongly alter the species composition, status, abundance and diversity of deadwood in plantations. Topographic factors and targeted cultivation practices promote the formation of deadwood

Analysis of Energy-Saving Transport Conditions of Light-Particle Slurry

Ice slurry, as a new environmentally friendly cold storage medium, is widely used in the field of cold storage and air conditioning because of its excellent flow and heat transfer characteristics. Based on experimental data of slurry flow, the rheological properties of light-particle slurries composed of polyethylene particles and water were analyzed using the response surface method. Using the yield stress and viscosity as the responses and considering three key influencing factors (solid-phase content, particle size, and pipe diameter) simultaneously, the order and law influencing the rheological factors were found. This was a new attempt to find energy-saving conditions for light slurry particle transport using the response surface method. The results showed that the response surface method can select the minimum working condition of mixed slurry viscosity and yield stress to ensure the safe and energy-saving transport of slurry. Moreover, it was also found that the main factor influencing slurry yield stress is the pipe diameter, and the yield stress increases with increasing pipe diameter. The main factor influencing slurry viscosity is particle size, and the viscosity increases with increasing particle size

Ultra Low Frequency Wave Produced by Underwater Oscillating Sphere and Its Measurement

When an underwater target moves in viscous fluid, it may cause the periodic movement of the surrounding fluid and generate ultra-low-frequency (ULF) gravity waves. The initial domain of the gravitational surface wave propagating above the moving target is named circular wave. This article studies the ULF circular wave generated by underwater oscillating sphere, which will provide basis for underwater long-range target detection. Firstly, the circular wave caused by the sphere oscillation in a finite deep fluid is studied based on the theory of linear potential flow. Meanwhile, the multipole expansion theory is established to solve the circular wave field. Secondly, the interface wave generated by the target oscillation in a two-layer fluid are numerically analyzed by comparison with the free surface fluctuation of a single-layer fluid. The results show that the amplitude of the internal interface displacement (AIID) is smaller than that of the free surface (AFSD). When the sphere is in the lower layer, the layering effect of the fluid has significant influences on the AFSD. Finally, the results of the pool experiment verified that the wave generated by the oscillating sphere is the surface gravity wave. Furthermore, the change trend of the test result is consistent with the simulation result

Ultra Low Frequency Wave Produced by Underwater Oscillating Sphere and Its Measurement

When an underwater target moves in viscous fluid, it may cause the periodic movement of the surrounding fluid and generate ultra-low-frequency (ULF) gravity waves. The initial domain of the gravitational surface wave propagating above the moving target is named circular wave. This article studies the ULF circular wave generated by underwater oscillating sphere, which will provide basis for underwater long-range target detection. Firstly, the circular wave caused by the sphere oscillation in a finite deep fluid is studied based on the theory of linear potential flow. Meanwhile, the multipole expansion theory is established to solve the circular wave field. Secondly, the interface wave generated by the target oscillation in a two-layer fluid are numerically analyzed by comparison with the free surface fluctuation of a single-layer fluid. The results show that the amplitude of the internal interface displacement (AIID) is smaller than that of the free surface (AFSD). When the sphere is in the lower layer, the layering effect of the fluid has significant influences on the AFSD. Finally, the results of the pool experiment verified that the wave generated by the oscillating sphere is the surface gravity wave. Furthermore, the change trend of the test result is consistent with the simulation result

Construction of compatible and additive individual tree biomass models for Pinus tabulaeformis in China

Current biomass models for Chinese pine (Pinus tabulaeformis) fail to accurately estimate biomass in large geographic regions because they were: usually based on limited sample trees on local sites; incompatible with stem volume; and not additive among components and total biomass. This study was based on mensuration data of individual tree biomass from large samples. The purpose was to construct compatible and additive biomass models using error-in-variable simultaneous equations and dummy variable modeling approach. This approach could ensure compatibility of aboveground biomass model with biomass conversion factor (BCF) and stem volume model, and compatibility of belowground biomass model with root-to-shoot ratio (RSR) model. Also, stem, branch and foliage biomass models were additive to aboveground biomass model. Results showed that mean prediction errors (MPEâ s) of the developed one- and two-variable aboveground biomass models were less than 4%, the MPEâ s of three components (stem, branch, and foliage) and belowground biomass were less than 10%. Furthermore, climate impact on above- and below-ground biomass were analyzed. Aboveground biomass was related to mean annual temperature (MAT), while belowground biomass had no significant relationship with either MAT or mean annual precipitation (MAP). The developed models provide a good basis for estimating biomass of Chinese pine forests.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Effect of Nanodiamond Concentration and the Current Density of the Electrolyte on the Texture and Mechanical Properties of Ni/Nanodiamond Composite Coatings Produced by Electrodeposition

An Ni/nanodiamond composite coating was deposited on carbon steel in a traditional Watt’s solution without additives via direct current (DC) electroplating. The effects of the nanodiamond concentration and current density in the plating solution on the morphology, grain size, and texture of the Ni/nanodiamond composite coating were observed using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The distribution of the nanodiamond particles in the composite coating was investigated by Raman spectra and SEM. The mechanical properties of the composite coating, such as its elastic modulus and hardness, were examined using a Nano Indenter XP nanometer mechanical test system. The coefficient of friction was tested using a Universal Micro-Tribotester. The results demonstrated that the preferential orientation of the Ni/nanodiamond composite coating varied from the (111) crystal orientation of the pure nickel coating to the (200) crystal orientation. When the nanodiamond concentration in the plating solution was 8.0 g/L and the current density was 3.0 A/dm2, the hardness of the composite coating reached the maximum value of 5.302 GPa and the friction factor was maintained at around 0.1. The average grain size of the composite coating was reduced to 20.4 nm