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In order to improve the stability of snake-like robot in unknown environment. The coordinated control method of snake like robot gait based on electromechanical tracking is proposed. The motion angles of each joint are designed according to the actual needs. The desired motion curve is designed based on the curve discretization. The coordinated control design of all kinds of gait is completed by discretization. The snake is realized by electromechanical tracking combined with the control system with TwinCAT soft PLC as the main control unit Gait coordination control of the robot. The experimental results show that the proposed method has good control effect on the snake like robot prototype's winding gait and plane rolling gait, and the overall performance and control stability are good. It has certain reference value for the improvement and perfection of snake like robot in the future. [ABSTRACT FROM AUTHOR]

Study Design: Retrospective study of instrumentation failure after posterior vertebral column resection (pVCR) in adult spinal deformity (ASD) patients.Objective: The morbidity and related risk factors of the instrumentation failure.Summary Of Background Data: Instrumentation failure is another common complication after pVCR. But no report about it has been published before. The safety of titanium mesh cages (TMCs) for this failure is still unknown so far.Methods: A total of 35 consecutive ASD patients (18 females and 17 males), who underwent pVCR between May 2005 and December 2014 in our hospital, were retrospectively reviewed. The mean age and follow-up period were 37.8 ± 12.8 years and 45.5 ± 27.3 months. Proportion was used to describe the morbidity of instrumentation failure. Potential risk factors were compared between patients with and without instrumentation failures by using Student t test or χ tests (Fisher exact tests). Risk factors related to TMCs were analyzed in TMC group.Results: There were 70 vertebra resected in total, with the mean of 10.3 segments instrumented. The mean correction rates of main curve (n = 25) and segmental kyphosis (n = 35) were 68.8% and 67.9%, respectively. Five patients (14.3%) suffered rod breakage. The failure was noted an average of 6.8 months after surgery. The risk factors included BMI (>27, P = 0.026), comorbidity (Achondroplasia, P = 0.047), and anterior column defect (ACD>20 mm, P = 0.045). TMC subsidence of ≥5 mm was the risk factor related to TMC in TMC group (P = 0.041).Conclusion: It is safe to reconstruct with a TMC after pVCR in ASD, but the height should be as low as possible to reduce ACD. For those patients with risk factors, autologous bone graft and a satellite rod should be considered. If TMC subsidence ≥5 mm, a frequent follow-up should be performed.Level Of Evidence: 4. [ABSTRACT FROM AUTHOR]

Background: Posterior hemivertebra resection has become a safe and effective procedure for congenital scoliosis due to hemivertebra. However, there are still complications following primary posterior hemivertebra resection in recent reports. No risk factors associated with construct/implant related complications were identified so far. The purpose of this study is to analyze complications following primary posterior hemivertebra resection and to investigate the possible risk factors associated with construct/implant related complications in congenital scoliosis cases due to hemivertebra.Methods: One hundred and sixteen congenital scoliosis cases with hemivertebra (male: female = 62:54), who underwent primary posterior hemivertebra resection from January 2003 to January 2012 in our medical center, were retrospectively evaluated in this study. Medical records were reviewed and long cassette standing spinal radiographs were measured before surgery, after surgery and at the final follow-up. Complications, including construct/implant related complications and non-construct/implant related ones, were recorded by chart review. Potential risk factors, including sex, age, segmental and main scoliosis and their correction rates, usage of cage (yes or not), fusion levels (bisegmental fusion or not), location of hemivertebra and contralateral bar/rib synostosis (with or without), were also collected.Results: The mean age of initial surgery was 9.8 years old (range, 2-19 years), and the average follow-up was 67 months (range, 24-133 months). The segmental scoliosis was corrected from 34.7° ± 11.9° to 7.1° ± 5.6° post-operatively, and 9.5° ± 7.0° at the latest follow-up, with a correction rate of 79.5 %. The total main scoliosis was corrected from 43.0° ±15.6° to post-operative 11.4° ± 6.8°, and 13.9° ± 7.5° at the latest follow-up, with a mean correction rate of 73.5 %. Complications occurred in 11 out of 116 cases (9.5 %), including 7 (63.6 %) construct/implant related complications (two pedicle misplacement, one rod breakage and four implant removals due to screw dislodgement with the growth) and 4 (36.4 %) non-construct/implant related ones (one proximal adjacent kyphosis, one progressive kyphosis, and two wound non-union). Younger age (≤5 years old), lumbar hemivertebra resection, or bisegmental fusion may contribute to a higher prevalence of construct/implant related complications than other cases, although the number of cases was too small to perform statistical analysis.Conclusions: The occurrence of construct/implant related complications in patients with hemivertebra resection is most likely multifactorial. Cases with younger age, bisegmental fusion, or lumbar hemivertebra may increase the risk of construct/implant related complications. Measures, such as careful preoperative evaluation and surgical plan with CT scan, sophisticated operation during surgery, usage of cage or cross-links to improve postoperative instant stability, protection in brace and regular follow-up postoperatively, should be taken to reduce construct/implant related complication rate. [ABSTRACT FROM AUTHOR]

Background: There have been many reports on posterior hemivertebra resection. However, there were few articles in very young cases. This is a clinical retrospective study to evaluate the complications and efficacy of posterior hemivertebra resection in very young cases. Methods: From January 2003 to January 2012, 39 consecutive cases of congenital scoliosis with hemivertebra were retrospectively investigated in our hospital, including 18 females and 21 males, aged from 21 to 65 months old (average 42.4 months). All the cases underwent posterior hemivertebra resection with transpedicular instrumentation. Clinical charts and radiographs of spine were retrospectively reviewed to record complications and outcomes postoperatively and at the latest follow-up. Results: Mean operation time was 186.4 min (90-280 min) with average blood loss of 306.6 (100-700) ml. The total number of hemivertebrae resected was 43, including one hemivertebra in 35 cases and two hemivertebrae in 4 cases. The mean number of fused segments was 3.4, including 22 cases (56.4 %) with bisegmental fusion and 4 cases with mesh cage. Average follow-up period was 5.4 (3 to 11) years. There was a mean improvement rate of 83.6 % in the segmental scoliosis from 38.4° before surgery to 6.3° after operation and a mean improvement rate of 81.9 % in segmental kyphosis from 17.1° to 3.2° over the same time. The spontaneous correction rates of the compensatory cranial curve and compensatory caudal curve were 65.7 and 66.9 %, respectively. There were three complications (two cases),one pedicle fractures, one rod breakages, and one additional surgery for curve progression. Besides these, two additional surgeries (two cases) were performed to remove the instrumentation for pedicle elongation in the follow-up. There was no neurological complication. Conclusions: Posterior hemivertebra resection with transpedicular instrumentation is a safe and effective procedure in very young congenital scoliosis cases. Earlier surgeries can achieve short fusion and save more mobile segments. However, complications associated with implants and spinal growth still remain major concerns. [ABSTRACT FROM AUTHOR]

Two strains of neutralizing monoclonal antibodies (MAbs) anti-ricin, both B chain and A chain, named 3D74 and 4C13, were generated efficiently. The two antibodies recognized different epitopes located in a separatedtoxin structure domain characterized by enzyme-linked immunosorbent assay (ELISA) and Western blotting. 3D74 recognized space conformation epitope, whereas 4C13 recognized linearity epitope of ricin. 4C13 possessed a novel neutralizing ability; the safe period for intraperitoneal injection of 100 µg of antibody was 30 min after intraperitoneal injection of 2 µg of ricin (10 times LD50). Using 3D74 and 4C13 as pair-matching antibodies, we established sandwich ELISA and rapid ELISA for detection of ricin. The detection sensitivitieswere 31.3 and 156 pg/ml, respectively. Rapid sandwich ELISA was sufficiently sensitive and was performed easily for ricin detection without any special instruments. [ABSTRACT FROM AUTHOR]

Walking to school promotes the health of school‐aged children. The safety and comfort of the walking environment are lacking in China due to the prioritization of motorized traffic. This paper focuses on the choice of walking routes for school‐aged children commuting in old urban areas of China. A walking route choice model is constructed by combining a weighted Voronoi diagram and the closest facility analysis in ArcMap. The walking route choices of school‐aged children from home to school and the flows along routes are analysed. Based on the model results, targeted design suggestions for updating existing street spaces are proposed. [ABSTRACT FROM AUTHOR]

Boehmite was prepared efficiently by adding alditols to Al-H2O reaction crystallization in moderate condition. We demonstrate that it is the interaction between alditols and metastable intermediates that inhibits the decomposition of aluminate ions into gibbsite and favors the formation of boehmite rather than the blocking of gibbsite growth sites as reported in the previous investigations. The analysis of the crystal formation process shows that the alditols play a role before the nucleation. The interaction simulated by density functional theory and the local hard and soft, acids and bases theory suggests that the metastable intermediates act as soft bases, while the alditols play the role of acids in the interaction, and the higher the alditols' softness, the stronger the inhibiting effect. The configuration of the interacting metastable intermediates and alditols was also verified by the comparison of both experimental and computational Fourier transform infrared spectra. The interaction between alditols and metastable intermediates inhibits the decomposition of aluminate ions into gibbsite and favors the formation of boehmite in Al-H2O reaction crystallization. In the interaction, the metastable intermediates act as soft bases, while alditols play the role of acids, and the higher the alditols' softness, the stronger the inhibiting effect. [ABSTRACT FROM AUTHOR]

A new integration method of the optimal square approximation method (OSAM) and the second order reliability method (SORM) was presented to ensure the mechanism structure design more reliable and robust. As for arbitrary distribution variables of mechanical structure design, the performance function of mechanical structure is expanded into the second-order Taylor series, the probability density function (PDF) and the first four moments (FFM) including the mean, the variance, the third-order moment and the fourth-order moments of performance function, which can be obtained according to the integration of OSAM and SORM. The numerical example of power-output shaft flange demonstrates that the sensitivity matrix conforms to the qualitative analysis for reliability design, and the presented integration method has the characteristics of high engineering precision in the reliability-based robust design of mechanical structure. [ABSTRACT FROM AUTHOR]

Oligomeric adamantane surfactants are novel surfactants using rigid adamantane as spacer group, which can form a variety of scales and shapes of micelles and aggregates in aqueous solution. In this paper, the self-assembling aggregate behavior of N,N-dimethyl dodecyl ammonium bromide adamantine [Ad-(NC12Br)], 1,3-di(N,N-dimethyl dodecyl ammonium bromide) adamantine [Ad-(NC12Br)2] and 1,3,5-tri-(N,N-dimethyl dodecyl ammonium bromide) adamantine [Ad-(NC12Br)3] in aqueous solution is studied by mesoscopic simulations of dissipative particle dynamics (DPD). The simulation results show that the critical micelle concentrations of the three adamantane oligomeric surfactants is in the order of [Ad-(NC12Br)3] < [Ad-(NC12Br)2] < [Ad-(NC12Br)]. The three oligomeric adamantane surfactants are able to form aggregates with a variety of spatial structures, such as spherical micelles, vesicles, lamellas, reticular lamellas, column lamellas or steric reticules in response to different surfactant concentrations in the aqueous solution. [ABSTRACT FROM AUTHOR]

Corn rust disease can be classified into four types: common corn rust, southern corn rust, tropical corn rust and stem corn rust. In this paper, 270 samples of corn rust gathered from Yunnan province were identified by observation of symptom and pathogen morphology, detection of specific molecular markers between Puccinia sorghi Schw and Puccinia polysora Unedrw. The results showed that 180 samples of corn rust collected form Qujing, Zhaotong, Kunming, Honghe (Mile, Kaiyuan and Jianshui) were common corn rust caused by Puccinia sorghi Schw; and 90 samples of corn rust collected form Wenshan and Honghe (Pinbian) were southern corn rust. Morphology and aspect ratio compared Puccinia sorghi Schw with Puccinia polysora Unedrw. The uredospores of Puccinia polysora Unedrw were oval and the aspect ratio of 81.6% of all uredospores from Puccinia polysora Unedrw was greater than 1.2. The uredospores of Puccinia sorghi Schw were nearly round, and their aspect ratio was 1.0-1.3. In addition, the population genetic structure of all corn rust samples was analyzed by ISSR molecular marker. Concerning Puccinia polysora Unedrw, the genetic diversity was larger in Wenshan than in Honghe. In Puccinia sorghi Schw, the population genetic diversity was larger in Zhaotong and the lowest in Kunming. [ABSTRACT FROM AUTHOR]

We investigate the request routing problem in the CDN-based Video-on-Demand system. We model the system as a controlled queueing system including a dispatcher and several edge servers. The system is formulated as a Markov decision process (MDP). Since the MDP formulation suffers from the so-called "the curse of dimensionality" problem, we then develop a greedy heuristic algorithm, which is simple and can be implemented online, to approximately solve the MDP model. However, we do not know how far it deviates from the optimal solution. To address this problem, we further aggregate the state space of the original MDP model and use the bounded-parameter MDP (BMDP) to reformulate the system. This allows us to obtain a suboptimal solution with a known performance bound. The effectiveness of two approaches is evaluated in a simulation study. [ABSTRACT FROM AUTHOR]

Abstract: Ricin A chain (RA), an N-glycosidase, is able to fatally disrupt protein synthesis by attacking the Achilles heel of the ribosome RNA (rRNA). As specific immunotoxins, emergence of inhibitors for RA may obtain access to antagonistics against ricin intoxication and contribute to ameliorate the concomitant side effects. Many experimental results showed that the engineered VHs, which possessed solubility, stability, small size and consequently easier to express, purify and manipulate in vitro, were self and long-lived molecules compared to synthetic peptides. In this study, based on the crystal structure of RA, a novel recombinant human single-domain antibody expressing a polypeptide against RA in the CDR3 loop (named rVHPT) was obtained using computer-guided molecular design method. Theoretically, rVHPT could penetrate deeply into the active cleft of RA and act as a potent antagonist analogue to block the RA–rRNA interaction. Followed results showed that the recombinant VHPT was easily expressed of high-yield production and in a partially soluble fusion form in Escherichia coli. In vitro cytotoxicity experiments demonstrated that it possessed remarkable ability to block ricin-induced cytotoxicity. This study highlights the potential of human VH to display biostructure and biofunction of peptides designed on RA functional domain and could be useful in developing new antidotes with potential therapeutic uses to neutralize unintended exposure to ricin. [Copyright &y& Elsevier]

For traditional experimental methods, the dynamic formation and transformation of amorphous calcium carbonate (ACC) are hard to capture due to its metastability and ease of transforming rapidly to the more stable phase. The emergence of microfluidic technology provides an effective approach on that issue, thus attracting widespread researchers' interest in crystallization research. In this study, based on laminar microfluidics, we demonstrate a microfluidic approach toward the study of the formation and transformation of ACC. Through the control of the velocity and concentration of CaCl2 and Na2CO3, the crystallization process was observed on a chip under the microscope. We show by in situ confocal micro Raman spectroscopy and theoretical calculation based on fluid dynamics simulation that the phase transformation pathways are different under the different supersaturation levels in laminar microfluidics. ACC does not always appear in the crystallization process; when supersaturation above the critical supersaturation of ACC occurred, the crystalline CaCO3 phases appeared after the metastable intermediates ACC through the transformation mechanism of dissolution-recrystallization, while the crystalline CaCO3 phases formed without the intermediates ACC when supersaturation below the critical supersaturation of ACC occurred. Our work provides an approach for the investigation of metastable intermediates and support for one-step and multistep nucleation mechanisms. [ABSTRACT FROM AUTHOR]

Study Design. Retrospective study. Objective. To study the behavior of the unfused thoracic curve in Lenke type 5C during the follow-up and to identify risk factors for its correction loss. Summary of Background Data. Few studies have focused on the spontaneous behaviors of the unfused thoracic curve after selective thoracolumbar or lumbar fusion during the follow-up and the risk factors for spontaneous correction loss. Methods. We retrospectively reviewed 45 patients (41 females and 4 males) with AIS who underwent selective TL/L fusion from 2006 to 2012 in a single institution. The follow-up averaged 36 months (range, 24-105 months). Patients were divided into two groups. Thoracic curves in group A improved or maintained their curve magnitude after spontaneous correction, with a negative or no correction loss during the follow-up. Thoracic curves in group B deteriorated after spontaneous correction with a positive correction loss. Univariate analysis and multivariate analysis were built to identify the risk factors for correction loss of the unfused thoracic curves. Results. The minor thoracic curve was 26° preoperatively. It was corrected to 13° immediately with a spontaneous correction of 48.5%. At final follow-up it was 14° with a correction loss of 1°. Thoracic curves did not deteriorate after spontaneous correction in 23 cases in group A, while 22 cases were identified with thoracic curve progressing in group B. In multivariate analysis, two risk factors were independently associated with thoracic correction loss: higher flexibility and better immediate spontaneous correction rate of thoracic curve. Conclusion. Posterior selective TL/L fusion with pedicle screw constructs is an effective treatment for Lenke 5C AIS patients. Nonstructural thoracic curves with higher flexibility or better immediate correction are more likely to progress during the follow-up and close attentions must be paid to these patients in case of decompensation. [ABSTRACT FROM AUTHOR]