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Aiming at the time-varying bounded uncertainty in the mechanical system and the problem of excessive control gain caused by the "worst case", a robust control with tunable parameters that can be used to compensate for the uncertainty is proposed. The proposed control can guarantee that the system has uniform boundedness and uniform ultimate boundedness. Besides, the fuzzy set theory is used to describe the uncertainty to avoid introducing any IF-THEN fuzzy logic rules or probability theory. Based on the non-cooperative game theory, the parameters of the proposed control are optimized. We treat mutually independent parameters to be optimized as players, then design performance indexes for each parameter as its cost function, and solve the optimal result by the definition of Nash equilibrium. Finally, taking the trajectory tracking control of omnidirectional mobile platform as an example, the feasibility of the optimization method and the effectiveness of the control are verified by comparing with the other two control methods. • The uncertainty in mechanical system is described by fuzzy set theory. • A robust control with exponential part to compensate the time-varying uncertainty is designed. • The uniform boundedness and uniform ultimate boundedness of the system are guaranteed. • The optimal parameters in the control are obtained to balance the control cost and system performance based on the non-cooperative game theory. [ABSTRACT FROM AUTHOR]

Enzyme induced carbonate precipitation (EICP) based on self-extracted crude soybean urease solution (CSUS) is a promising method for soil improvement. However, the deionized water-extracted CSUS usually contains a large amount of impurities that easily lead to bioclogging during the biogrouting process, resulting in a nonuniform biomineralization effect. In this study, a purification method using inorganic flocculants is proposed to extract CSUS with relatively high purity and urease activity (UA) for EICP method. Seven commonly used inorganic flocculants were adopted in this study, including KAl(SO 4) 2 •12H 2 O, AlCl 3 •6H 2 O, Al 2 (SO 4) 3 •18H 2 O, Fe 2 (SO 4) 3 , poly aluminum chloride, poly ferric sulfate, and poly aluminum ferric chloride. Three sets of tests, including CSUS extraction tests, solution tests, and sand column treatment tests, were conducted to investigate the feasibility and validity of this purification method. The test results show that inorganic flocculants could effectively reduce the turbidity of the extracted CSUS, avoid the bioclogging during biogrouting, and thus improve the biomineralization effect of the CSUS-based EICP method. Compared with deionized water-based CSUS, at least 60% of the impurities in CSUS can be removed at optimal flocculant contents when the soybean powder content is 100 g/L. On the other hand, the flocculants would also cause a reduction in the UA of the extracted CSUS. Considering the UA, turbidity, and biomineralization effect of the extracted CSUS, the optimal inorganic flocculants and their contents are recommended to be 3.0 g/L for KAl(SO 4) 2 •12H 2 O, 2.0 g/L for AlCl 3 •6H 2 O, 2.5 g/L for Al 2 (SO 4) 3 •18H 2 O under the tested conditions, respectively. [ABSTRACT FROM AUTHOR]

In this research, to achieve the altitude and attitude tracking control of an underactuated quadrotor UAV with mismatched uncertainties, based upon Udwadia–Kalaba theory, a novel adaptive robust tracking control approach is proposed and which will be designed in two steps. First, aiming at the uncertain and underactuated quadrotor UAV, regardless of initial constraint deviation and mismatched uncertainties, a nominal control is constructed through transforming the desired trajectories into corresponding servo constraints; second, for the mismatched uncertainties, we decompose them into two parts, i.e. the matched part and mismatched part, and the mismatched part will "vanish" during the stability analysis of proposed adaptive robust controller. Eventually, with such a decomposition technique, the large mismatched uncertainties can be addressed properly and the burden of controller design will be reduced to a certain degree. In addition, two deterministic robust control performances are also guaranteed by our proposed approach. The simulation results have shown a good robustness and tracking precision of our proposed scheme for quadrotor UAV. • The uncertainties have been decomposed into the matched and mismatched part. • A strong robustness against mismatched uncertainties is ensured by proposed scheme. • The mismatched part will "vanish" during the stability analysis of control system. • All the uncertainties have been lumped into two adaptive parameters. [ABSTRACT FROM AUTHOR]

Vibrio parahaemolyticus is a widespread bacterium in the marine environment and is one of the leading causes of food-derived bacterial poisoning in humans worldwide. The main objective of this study was to determine the prevalence, virulence factors, and antibiotic and heavy metal resistance profiles of V. parahaemolyticus in Pacific mackerel (Pneumatophorus japonicus) from different markets in Zhejiang Province, People's Republic of China. In total, 112 (31.11%) V. parahaemolyticus isolates were identified from 360 Pacific mackerel samples, with an extremely low occurrence of the virulence genes trh (1.79%, 2 of 112) and tdh (0%, 0 of 112). Antibiotic resistance testing revealed that most isolates showed resistance to ampicillin (96.43%, 108 of 112) and streptomycin (90.18%, 101 of 112), whereas all strains were sensitive to kanamycin, florfenicol, cefamandole, and trimethoprim-sulfamethoxazole. Furthermore, 46.43% (52 of 112) of isolates, which had 12 different phenotypes, were classified as multidrug resistant. In addition, the multiple antibiotic resistance index values of isolates were between 0.05 and 0.63, and the maximum multiple antibiotic resistance index was attributed to two isolates that exhibited resistance to 12 antibiotics. Heavy metal resistance patterns were similar among the six different markets. The majority of isolates showed resistance to Cd2+ (78.57%) and Pb2+ (51.79%), and fewer were resistant to Cu2+ (37.50%), Zn2+ (25.00%), Co2+ (9.82%), Ni2+ (6.25%), and Mn2+ (4.46%). No isolates were resistant to Cr3+. In total, 22.32% (25 of 112) of strains were multiheavy metal resistant. Furthermore, multidrug resistance and multiheavy metal resistance were found to be positively correlated in the V. parahaemolyticus strains by using Pearson's correlation analysis (P = 0.008; R = 0.925). This information will contribute to the monitoring of variations in the antibiotic and heavy metal resistance profiles of V. parahaemolyticus strains from seafood and provide insight into the appropriate use of antibiotics and the safe consumption of seafood. [ABSTRACT FROM AUTHOR]

Purpose: There are many methods to reconstruct the mandible, but they are often accompanied by trauma, which can lead to scarring of the maxillofacial skin. The purpose of this study was to show the utility of a minimally invasive method for reconstruction of the mandible with nonvascularized iliac bone grafts without a skin scar, as well as to evaluate the success rate and complications.Patients and Methods: This was a retrospective case series. We retrospectively analyzed patients who underwent transoral resection of benign mandibular pathologies, followed by nonvascularized iliac bone graft reconstruction. The primary outcome variable was the success rate of the bone grafts. Secondary outcome variables were postoperative complications at the grafted bone recipient and donor sites, the long-term absorptivity of grafted bone, and the type of mandibular defect. We computed descriptive statistics or performed the χ2 test for each variable.Results: Overall, 54 patients were included in the study, including 21 male and 33 female patients, with an age range of 10 to 65 years. The complete survival rate was 87.0% (47 of 54 patients), and the partial survival rate was 98.1% (53 of 54). The average bone absorption rate 3 years after surgery was 1.8 to 30.7%. We propose a new classification method for mandibular defects based on the extent of the tumor, location of the osteotomy, and degree of surgical difficulty.Conclusions: Intraoral nonvascularized iliac bone grafting is a highly successful minimally invasive method for mandibular reconstruction. It is also one of the best methods for mandibular reconstruction in patients with benign mandibular tumors without soft tissue involvement. [ABSTRACT FROM AUTHOR]

The anterolateral thigh free flap is one of the most commonly used flaps in reconstructive procedures. The purpose of this study was to assess this new classification of chimeric anterolateral thigh free flaps. Sixty-five patients underwent free anterolateral thigh chimeric free flap reconstruction of defects in the head and neck region. We summarized the anatomic features of perforators, including the number and origin of the perforators. Sixty-five cases of femoral anterolateral double island flaps were divided into 3 types: trunk type (type I), 11 cases (16.9%), in which the perforators of two flaps originated in the descending branch and the transverse branch of the lateral femoral circumflex artery; branch type (type II), 45 cases (69.3%), in which both the perforators originated in the descending branch or the transverse branch of the lateral femoral circumflex artery; and bifurcation type (type III), 9 cases (13.8%), in which two perforators originated in the bifurcation of one perforator that originated in the descending branch or the transverse branch of the lateral femoral circumflex artery. All 65 flaps survived and none showed partial necrosis. The anterolateral thigh chimeric flap can be divided into 3 types: trunk type (I type), branch type (II type) and bifurcation type (III type). [ABSTRACT FROM AUTHOR]

Chitooligosaccharides (COSs) have continuously attracted considerable attention as numerous biological activities. The highly efficient preparation of COSs, however, is still a challenge. In this paper, a clean two-stage method is developed to hydrolyze chitosan at high concentration into COSs, comprising of pretreatment with hydrogen peroxide (H 2 O 2) and hydrolysis with food-grade cellulase. The pretreatment reduced the viscosity of chitosan solution quickly, making more chitosan dissolving. Chitosan solution at high concentration (9%, w/v) was successfully prepared by fed-batch chitosan during the oxidative pretreatment. Within 6 h, the chitosan was enzymatically hydrolyzed to oligosaccharides with degree of polymerization (DP) of 2–9 and a small amount of monosaccharide, which was analyzed by thin layer chromatography (TLC) and MALDI-TOF MS. In addition, the results from FT-IR and NMR spectra demonstrated the chemical structure of degraded chitosan was not significantly altered. In summary, the two-stage method shows great potential in large-scale production of COSs. Besides, it is expected to couple with membrane bioreactor and immobilized enzyme technology to realize production of COSs with controlled molecular weight. • A quick preparation technology of high concentration of chitosan solution was developed. • A two-stage method was established to product chitooligosaccharides from high-concentration chitosan. • Chitooligosaccharides with degree of polymerization 2–9 was obtained in 6 h. • The two-stage method is green and cost-effective. [ABSTRACT FROM AUTHOR]

Our study was conducted to investigate the antibiotic susceptibility profiles, integrons and their associated gene cassettes (GCs), and insertion sequence common regions of Escherichia coli isolates from Penaeus vannamei collected at a large-scale freshwater shrimp farm in Zhejiang Province, People’s Republic of China. A total of 182 E. coli isolates were identified from 200 samples. With the exception of imipenem, isolates were most commonly resistant to β-lactams, followed by tetracylines and sulfonamides. Fifty-two (28.6%) E. coli isolates were classified as multidrug resistant, and the patterns were highly diverse, with 29 types represented. The multiple-antibiotic resistance indices of the isolates were 0.17 to 0.56; 9.3% (17) of the 182 isolates were positive for class 1 integrons, 0.5% (1 isolate) was positive for class 2 integrons, and an insertion sequence common region 1 element was found upstream of the intI1 (integrase) gene in one of the intI1-positive isolates. Four GC arrays were detected in class 1 integrons, and one GC array was detected in class 2 integrons. Although the overall prevalence of antimicrobial-resistant bacteria in P. vannamei was lower than that previously reported for poultry and livestock farms in China, concerns about the inappropriate use of antibiotics and the transmission of antimicrobial-resistant bacteria in aquaculture were raised. Alternative approaches to reducing or replacing the use of antibiotics should be further studied. [ABSTRACT FROM AUTHOR]

Abstract Two-phase bubbly flows occur widely in nature and are extensively applied in industry. The aeration processes underwater is one type of two-phase bubbly flow that directly impacts on the downstream water quality by reducing the oxygen content in the water. The most important influencing factors for optimization design of Auto-venting turbines (AVTs), for solving the low level of dissolved oxygen (DO) in the discharged downstream water, are the quantity of entrained air, the bubble size distribution resulting from coalescence and breakage processes, and the rate of oxygen transfer from the bubbles. In order to better understand the influencing flow conditions on the bubble size distribution, in this paper a numerical investigation for flow around NACA0015 hydrofoil is carried out. The numerical simulations require the consideration of the dynamic behaviors of two-phase flow and bubbles undergoing coalescence and breakup. For this purpose, the ensemble-averaged mass and momentum transport equations for continuous and dispersed phases are modeled within the two-fluid modeling framework. These equations are coupled with population balance equations (PBE) to aptly account for the coalescence and break-up of the bubbles. The resultant bubble size, normalised velocity and void fraction distributions for different flow conditions including angle of attack (AOA), air-entrainment coefficient, and Reynolds number are presented and discussed. The results show that varying AOA has the most significant impact on the distribution of the bubbles in the wake. [ABSTRACT FROM AUTHOR]

Purpose: Free flap compromise after internal jugular venous thrombosis (IJVT) occurs fairly infrequently in oral and maxillofacial rehabilitation and reconstruction but could seriously affect the patient's postoperative recovery. The aim of this study was to analyze and discuss the characteristics and management of such flap compromise.Patients and Methods: The authors performed a retrospective case series of 13 patients who underwent reconstruction of oral and maxillofacial defects with anterolateral thigh flaps and developed flap compromise from IJVT from July 2014 through December 2016 at the Second Xiangya Hospital of Central South University (Changsha, China). The clinical features of flap compromise are described, and the precautions and improvement measures are reported.Results: All 13 patients were men with an average age of 50.3 years. Flap compromise caused by IJVT occurred on postoperative days 3 to 7, of which 2 flaps were salvaged (15.4%) and 11 flaps failed completely after immediate urgent re-exploration. Four patients presented with orocutaneous fistula after salvage surgery that healed well after a period of wound dressing.Conclusions: Because of the late occurrence and low salvage rate of flap compromise caused by IJVT, intensive flap monitoring after reconstruction surgery is necessary for patients with free flap transfer. [ABSTRACT FROM AUTHOR]

Soil arching effect is a key load-transfer component in pile-supported embankments. However, previous models that account for soil arching effect consider various assumptions and simplifications due to insufficient understanding of soil arching structures developed in pile-supported embankments. Consequently, the use of previous models in practice would potentially result in substantially different designs. This study aims to develop a reasonable classification system for the soil arching structures under different conditions, and to identify the characteristics and applicability of each structure. Firstly, a series of Discrete Element Method simulations were performed to investigate the evolution of soil arching structures under different conditions with emphasis on the embankment deformation behaviour. The simulation results show that soil arching structures under different conditions can be divided into three groups: (a) “shear plane arching”; (b) “partial arching”; and (c) “full arching”. This was followed by detailed analysis of the macro- and microscopic characteristics of each soil arching structure. Finally, the load-transfer mechanisms of the three soil arching structures are compared, and the influence of design parameters on the soil arching structure is discussed. It is concluded that contact force rotation induced by the pile-subsoil relative displacement causes the changes in load-transfer path, and thus the stress distribution is altered. However, the interaction and location of the rotated contact forces are considerably different under different conditions, which results in the development of various soil arching structures and significant differences in the deformation and the load-transfer mechanism of the pile-supported embankments. Two critical heights that govern the interaction and location of the rotated contact forces were identified: the critical arching height, h ca (i.e., 0.8( s - a )), and the critical overlying filling height, h co (i.e., 3.0 a ), where s is the pile spacing and a is the pile (or pile cap) width. It was shown that, for the design of the pile-supported embankments, both ( s - a ) and a should be considered. [ABSTRACT FROM AUTHOR]

In order to reduce the impact of load fluctuation, noise and vibration, the tooth surface of the gear in the high speed transmission gearbox is usually modified along the lead and profile direction. In this paper, a method for lead and profile crowning tooth flank of work gear is proposed by setting the movement of A and B axes as two fourth order polynomial functions of axial feed of work gear in the internal gearing power honing. Diamond dressing gear used for honing stone in dressing process is standard involute, and it is not necessary to design an especial diamond dressing gear for each different modified gear. The sensitivity matrix of polynomial coefficients is calculated by the normal deviation of the gear tooth surface, and the influence of the variation of polynomial coefficients on the tooth surface is studied. The honed tooth surface can be approximated to the given tooth surface by adjusting the polynomial coefficients through least squares estimation with the aim of minimization of the tooth surface errors based on sensitivity matrix. The effectiveness of this crowning tooth flank modification method is confirmed numerically using a helical gear on the internal gearing power honing machine. [ABSTRACT FROM AUTHOR]

Purpose: The reconstruction of massive through-and-through oromandibular defects is still a challenge because no single adequate candidate for a donor site of vascularized bone and a large amount of soft tissue has yet been found. The aim of this study was to evaluate the feasibility and reconstructive efficacy of the combined fibula flap and anterolateral thigh (ALT) flap in tandem for the reconstruction of such defects.Patients and Methods: We performed a retrospective case series of patients who had undergone reconstruction of through-and-through oromandibular defects with the combined fibula flap and ALT flap in tandem from January 2012 through December 2014 at the Second Xiangya Hospital. The flap design and the methods for defect reconstruction are described, and the reconstructive efficacy is reported.Results: Of the 14 patients, 13 were men and 1 was a woman, with an average age of 49.36 years. Postoperatively, all flaps survived completely, without vascular compromise or major wound complications. All of the donor sites were closed directly, leaving only linear scars and no thigh or leg motor dysfunction. All patients were followed for approximately 12 to 48 months, and the appearance and oral functions were acceptably recovered in about 90% of the patients.Conclusions: Because of the convenient flap design, satisfactory functional and esthetic results, and lower complication rates at the donor and recipient sites, the use of a combined fibula flap and ALT flap in tandem is a good choice for the reconstruction of complex through-and-through oromandibular defects. [ABSTRACT FROM AUTHOR]

In this paper, the active disturbance rejection controller (ADRC) for the electronic gearboxes (EGB) is proposed to solve the problem of gear deviation caused by the change of cutting force. Firstly, we analyzed the principle of the CNC hobbing process and established the machine tool kinematic model and EGB control precision model. Then, to achieve self-compensation for the system disturbance, the ADRC is utilized. In addition, an improved particle swarm optimization algorithm is introduced to address the issue of the ADRC's parameters being hard to select. Finally, the EGB is designed using a composite structure and combined with the ADRC. We compare master–slave and composite EGB for experimental verification using a CNC hobbing machine as an example. The proposed composite EGB method is obtained through numerical simulation and experiments to effectively verify the EGB control precision of the CNC hobbing machine. Meanwhile, the tracking precision of each motion axis is improved obviously. The proposed composite EGB method solves the issue of self-compensating disturbances in CNC hobbing machine tools from the controller design. It provides a novel design method that can apply to all kinds of CNC machine tools to deal with disturbance problems. • The proposed ADRC controller keeps PID's original quick convergence property and eliminates overshoot. • Select the best parameters, potentially improving the synchronization precision of each motion axis of the CNC machine tool. • In comparison to the master–slave EGB approach, the proposed ADRC-EGB method has a lower synchronization control error. [ABSTRACT FROM AUTHOR]

Purpose: Vascular anastomosis is the most important technical step required for the possibility of free tissue transfer, and mismatch of the donor and recipient vessel size is the most common surgical challenge. As recent reports have described a new method (Ren anastomosis) to resolve this challenge, the goal of this study was to assess these newly described microvascular anastomosis methods.Patients and Methods: The study was conducted at 2 institutes in China in different periods. Patients were recruited from the Second Xiangya Hospital between February and May 2013 and from the Shanghai Ninth People's Hospital between March and May 2015. All patients who participated in this study needed free flaps for oral and maxillofacial defects. Patients were divided into the experimental group and the control group. In the experimental group, isometric double-notch end-in-end microvascular anastomosis (Ren anastomosis) was performed, whereas end-to-end anastomosis was performed in the control group. Statistical differences were assessed by use of χ2 and t tests.Results: A total of 148 patients (108 men and 40 women) were treated over the course of this study. There was a statistically significant difference (P < .001) in the operation time for the microscopic artery anastomosis between the experimental group (70 cases; 5.6 ± 1.8 minutes) and the control group (78 cases; 14.6 ± 3.7 minutes). In each group, 1 case of artery compromise was observed.Conclusions: The Ren anastomosis was time-saving, straightforward, efficient, and easy to learn, with a high patency rate. [ABSTRACT FROM AUTHOR]

Purpose: The vascular anastomosis of free flap with the internal jugular vein stump is susceptible to thrombosis, thus resulting in flap compromise or failure. This study aims to explore the method of longitudinal contraction venoplasty in the prevention of internal jugular vein stump thrombosis after free flap vascular anastomosis and its feasibility.Patients and Methods: A retrospective review was performed of 16 patients who underwent internal jugular vein resection because of cancer ablation and longitudinal contraction venoplasty to prevent internal jugular vein stump thrombosis after free flap vascular anastomosis from January 2013 through December 2014 at Second Xiangya Hospital. The methods for longitudinal contraction venoplasty and its efficacy are reported.Results: Venous anastomosis of all flaps was performed with the internal jugular vein stump, and single venous anastomosis was made in all cases. Postoperatively, all flaps survived completely, without vascular compromise. All the patients were followed for approximately 9 to 33 months, and they were satisfied with the esthetic and functional results of the donor and recipient sites after reconstruction.Conclusions: Longitudinal contraction venoplasty may be an effective new method for prevention of internal jugular vein thrombosis after free flap vascular anastomosis. [ABSTRACT FROM AUTHOR]

Background This study characterized the infiltration of primary tumors along the intrinsic and extrinsic muscles of the tongue in oral tongue squamous cell carcinoma (OTSCC), to create a new surgical strategy that is suitable for most stages. A preliminary evaluation of this novel surgical approach was also conducted. Methods An anatomic study of macroscopic specimens from 10 human cadavers and 100 OTSCC patients was conducted. The anatomic characteristics of the primary tumors and the origin and distribution of fibers of the intrinsic and extrinsic tongue muscles were observed and measured. After initial treatment with curative intent, the 100 patients were regularly followed-up with clinical examination and imaging. Result Based on the anatomic characteristics of the primary tumors and tongue muscles, a new surgical approach was developed, and was described as muscle anatomy tongue surgery (MATS). MATS proved suitable for almost all stages of OTSCC. According to the morphology of the invasive tumor front, the 100 cases were divided into four types. The rate of 2-year local disease control was 98%, locoregional control 86%, disease-free survival 85%, and overall survival 89%. Tongue functions were perfectly recovered in more than 60% of the patients. Conclusion Application of the principles of MATS to the treatment of OTSCC proved suitable for almost all stages of the disease. MATS is a novel surgical technique that may improve outcomes in tongue cancer surgery. [ABSTRACT FROM AUTHOR]

Purpose To evaluate the feasibility and reconstructive efficacy of the thinned anterolateral thigh (ALT) flap for the reconstruction of head and neck defects. Patients and Methods A retrospective review was performed of 43 patients who had undergone reconstruction of head and neck defects with a thinned ALT flap from January 2009 through December 2013 at the Second Xiangya Hospital. The methods for flap thinning and defect reconstruction and reconstructive efficacy are reported. Results The flaps were 5 cm × 7 cm to 9 cm × 14 cm, and all were harvested from a single cutaneous perforator. Postoperatively, 40 flaps survived completely and 3 flaps experienced partial necrosis. Venous compromise occurred in 2 cases, both of which were salvaged after operative exploration. Of the 43 donor sites, 41 were closed directly and resulted in only linear scars, and 2 were closed using full-thickness skin grafts because the defect was larger. All the patients were followed for approximately 6 to 36 months, and they were satisfied with the esthetic and functional results of the donor and recipient sites after reconstruction. Conclusion With the high success rate of flap transplantation, satisfactory functional and esthetic results, and lower complication rates at the donor and recipient sites, the use of thinned ALT flaps can be a good choice for the reconstruction of head and neck defects in obese patients. [ABSTRACT FROM AUTHOR]

Purpose Although a promising approach, the use of anterolateral thigh (ALT) free flaps has been limited in the reconstruction of oral and maxillofacial defects in elderly patients. The aim of this study was to estimate the frequency of postoperative complications and identify factors associated with complications. Patients and Methods The authors designed and implemented a retrospective study on the frequency of postoperative complications in elderly patients. They enrolled a sample composed of patients who underwent ALT free flap transfers for the repair of defects created during oral and maxillofacial cancer surgery from February 2002 to March 2013. The χ 2 test, t test, and multivariate regression model were used. Results A total of 1,100 patients were studied (859 men and 241 women). One hundred four patients (9.5%) were at least 70 years old (elderly group) at the time of surgery; the other 996 patients were younger than 70 years (younger group). The overall success rate of ALT free flap transfer was 97.2% (97.0% in the younger group, 99.0% in the elderly group; P > .05). The overall complication rate was 27.5% (27.2% in the younger group, 29.8% in the elderly group; P = .572). Multivariate analysis showed that operation time, American Society of Anesthesiologists class, and comorbidity were independent risk factors for postoperative complications in elderly patients. Conclusions Oral and maxillofacial reconstruction using ALT free flaps in elderly patients can achieve outcomes similar to those obtained in younger patients. Limiting the operation time is important for improving surgical outcomes. [ABSTRACT FROM AUTHOR]

Reconstruction of through-and-through oral and maxillofacial defects has always been difficult. We have evaluated the feasibility and reconstructive efficacy of chimeric flaps pedicled with the lateral circumflex femoral artery in the reconstruction of 41 through-and-through oral and maxillofacial defects after resections for cancer. There were 29 chimeric anterolateral thigh and anterolateral thigh flaps and 12 chimeric anterolateral thigh and anteromedial thigh flaps, the sizes of which ranged from 5 × 8 to 9 × 11 cm. The chimeric flaps provided separate flaps to reconstruct the intraoral mucosa and extraoral skin defects, and 40/41 of them survived. The appearance and function were satisfactory in all patients after the reconstruction. Chimeric flaps pedicled with the lateral circumflex femoral artery are a good choice for the reconstruction of through-and-through oral and maxillofacial defects. [ABSTRACT FROM AUTHOR]

Background The anterolateral thigh myocutaneous flap is one of the most commonly used flaps in reconstructive procedures, but its application in oral and maxillofacial defects has not been fully determined. Herein, we summarize the application of 1212 anterolateral thigh myocutaneous flaps in the repair of oral and maxillofacial defects and examine their benefits in maxillofacial reconstruction of these defects. Methods Patients were recruited from February 2002 to June 2013 in the Department of Oral and Maxillofacial Surgery of Central South University. All patients underwent reconstructive surgery employing anterolateral thigh myocutaneous flaps. Patient ages ranged from 6 to 82 years with a mean age of 51.2 years. There are 1015 flaps showing single lobe and 197 flaps showing a multi-island pedicle and one of which carries the iliac bone. The largest area among the single flaps was 28 × 12 cm 2 , and the smallest was 3 × 2 cm 2 . Results Among the 1212 transferred flaps, 1176 survived and 36 showed necrosis, a survival rate of about 97.0%. The common complications at flap donor site were poor wound healing (10.1%), localized paraesthesia (50.1%), and altered quadriceps force (11.0%). No cases presented with local serious complications, and 90% of patients achieved good functional recovery and aesthetically acceptable results after reconstruction of oral and maxillofacial defects at various locations using anterolateral thigh myocutaneous flaps. The time (23–121 min; average 51 min) for anastomosis of one vein and one artery was significantly less than that for two veins and one artery (45–153 min, average 83 min; p = 0.0003), which indicates one vein anastomosis can significantly reduce the operating time. Conclusion The anterolateral thigh myocutaneous flaps can be easily obtained and can provide a good amount of muscle for filling dead space and fascia lata. These flaps can be prepared into a separate fat flap, multi-island fascia with iliac bone, and other composite pedicle flaps to meet the various requirements of oral and maxillofacial defects. The subcutaneous fat thickness of the anterolateral area can vary considerably and thus can be used to repair defects requiring different flap thickness. Therefore, the anterolateral thigh myocutaneous free flaps are more suitable for oral and maxillofacial defects than other flaps. [ABSTRACT FROM AUTHOR]

Geogrid-reinforced and pile-supported (GRPS) embankments have been widely used in road engineering due to their economy and effectiveness. The soil arching effect is a key factor in the load transfer mechanism of GRPS technique. In this study, a series of numerical simulations are conducted with the particle flow code PFC2D to study the evolution of soil arching with increasing surcharge. First, an Improved Multi-layer Compaction Method (IMCM) is proposed and applied to establish the Discrete Element Method (DEM) models with more reasonable initial stress states. Validation is then conducted by comparing the DEM results with experimental data. Second, detailed macro-behaviour (e.g., efficacy) and micro-behaviour (e.g., contact forces and fabric anisotropy) analyses are performed. Finally, parametric study is performed to identify the effects of two key factors, i.e., the stiffness of subsoil and the grain composition of embankment fill. Simulation results indicate that the strong force network (SN) serves as a load-carrying force chain, which is the main component of soil arching; while the weak force network (WN) acts as a support system. When a pile-supported embankment is high enough, the soil arching will experience three stages as the surcharge increases. In the first stage, the soil arching develops and its effect is strengthened gradually. In the second stage, the soil arching is fully mobilized and experiences a "forming-failure-reforming" process as the surcharge increases. While in the third stage, the embankment is unable to form a new stable soil arching and the efficacy decreases gradually. However, for the GRPS embankment, due to the reinforcement of geogrid, the third stage will not occur throughout the entire surcharge range of interest in this study. On the basis of the macro- and micro-results, the conclusion can be drawn that the presence of geogrid does not alter the failure mode of soil arching under the surcharge, though it is able to evidently improve the efficacy of load transfer and enhance the stability of soil arching. [ABSTRACT FROM AUTHOR]

Purpose: To discuss the vascular anatomy of the anteromedial thigh (AMT) flap and to evaluate the feasibility of the AMT flap for the reconstruction of oral and maxillofacial defects. Patients and Methods: A retrospective review was performed of 18 patients who underwent reconstruction of oral and maxillofacial defects with AMT flaps from January 2009 through December 2011 in the Second Xiangya Hospital. Eleven unifoliate AMT flaps were elevated to reconstruct defects of the tongue, soft palate, and floor of the mouth and 7 chimeric anterolateral thigh (ALT) and AMT flaps were harvested to reconstruct through-and-through cheek defects. Results: The flaps were 4 × 6 to 9 × 11 cm2. All the AMT flaps were nourished by the descending branch (DB) of the lateral circumflex femoral artery. The cutaneous perforators were derived from the rectus femoris branch of the DB in 15 cases and directly from the DB in the other 3 cases. Postoperatively, all flaps survived completely, without major complications. Of the 18 donor sites, 14 were closed directly, leaving only linear scars, and 4 were closed using full-thickness skin grafts owing to larger defects. All patients were followed for approximately 6 to 30 months, and they were satisfied with the esthetic and functional results of the donor and recipient sites after the reconstruction. Conclusions: Because of easy perforator dissection, the AMT flap can be used as an alternative to the ALT flap or harvested with the ALT flap as chimeric ALT and AMT flaps for the reconstruction of oral and maxillofacial defects. [ABSTRACT FROM AUTHOR]

Purpose: To discuss the feasibility of making anterolateral thigh flaps of different thicknesses in the anterior thigh region and to provide clinical guidance on raising anterior thigh polyfoliate (myocutaneous) flaps. Patients and Methods: Sixty-six patients who underwent oral and maxillofacial malignant tumor resection and reconstruction with left anterior thigh flaps from October 2008 to April 2009 in the Second Xiangya Hospital were selected as the subjects. The thickness of subcutaneous fat in different parts of the anterior thigh region was measured and the distribution, number, type, and origin of cutaneous perforators in the left anterior thigh region were explored by anatomic observation. Results: The thickness of subcutaneous fat in the anterior thigh region was thinnest in the lower part, medium in the middle part, and thickest in the upper part. The probabilities of cutaneous perforators in the upper, middle, and lower parts of the anterolateral thigh region were 83.3%, 97%, and 89.4%, respectively, and those in the anteromedial thigh region were 51.5%, 84.9%, and 95.5%. On average, there were 4.4 cutaneous perforators in the anterolateral thigh region and 3.3 cutaneous perforators in the anteromedial thigh region of each patient. In addition, 57.6% of patients had cutaneous perforators arising from the descending branch of the lateral circumflex femoral artery in the anteromedial thigh region. Conclusions: Flaps with different thicknesses could be harvested in different parts of the anterolateral thigh region and polyfoliate (myocutaneous) flaps could be conveniently raised in the anterior thigh region. [Copyright &y& Elsevier]

Abstract: Ship Energy Management System (SEMS) was the ship power system management and control center based on network. The real-time and reliability of network was the foundation of SEMS reliable operation. The characteristics of SEMS were analyzed by comparing with the land energy management systems, and the network topology was proposed based on switched Ethernet. The major traffics of SEMS were classified by its real-time and modeled in OPNET. Then the factors which affected the traffic real-time transmission were analyzed, and for which the solution methods were given and tested. This simulation approach also provides a reference method to study the future SEMS network. [Copyright &y& Elsevier]