Research progress of vascularization strategies of tissue-engineered bone

The bone defect caused by fracture, bone tumor, infection, and other causes is not only a problematic point in clinical treatment but also one of the hot issues in current research. The development of bone tissue engineering provides a new way to repair bone defects. Many animal experimental and rising clinical application studies have shown their excellent application prospects. The construction of rapid vascularization of tissue-engineered bone is the main bottleneck and critical factor in repairing bone defects. The rapid establishment of vascular networks early after biomaterial implantation can provide sufficient nutrients and transport metabolites. If the slow formation of the local vascular network results in a lack of blood supply, the osteogenesis process will be delayed or even unable to form new bone. The researchers modified the scaffold material by changing the physical and chemical properties of the scaffold material, loading the growth factor sustained release system, and combining it with trace elements so that it can promote early angiogenesis in the process of induced bone regeneration, which is beneficial to the whole process of bone regeneration. This article reviews the local vascular microenvironment in the process of bone defect repair and the current methods of improving scaffold materials and promoting vascularization

Perceived organizational career management and career adaptability as predictors of success and turnover intention among Chinese employees

Based on the theories of career construction and of social exchange, the current research examined the joint and interactive effects of perceived organizational career management and career adaptability on indicators of career success (i.e., salary and career satisfaction) and work attitudes (i.e., turnover intention) among 654 Chinese employees. The results showed that career adaptability played a unique role in predicting salary after controlling for the effects of demographic variables and perceived organizational career management. It was also found that both perceived organizational career management and career adaptability correlated negatively with turnover intention, with these relationships mediated by career satisfaction. The results further showed that career adaptability moderated the relationship between perceived organizational career management and career satisfaction such that this positive relationship was stronger among employees with a higher level of career adaptability. In support of the hypothesized moderated mediation model, for employees with a higher level of career adaptability, the indirect effect of perceived career management on turnover intention through career satisfaction was stronger. These findings carry implications for research on career success and turnover intentio

The Effect of Deep Cryogenic Treatment on the Corrosion Behavior of Mg-7Y-1.5Nd Magnesium Alloy

The effect of quenching on the corrosion resistance of Mg-7Y-1.5Nd alloy was investigated. The as-cast alloy was homogenized at 535 °C for 24 h, followed by quenching in air, water, and liquid nitrogen. Then, all of the samples were peak-aged at 225 °C for 14 h. The microstructures were studied by scanning electron microscopy, energy-dispersive spectrometry, and X-ray diffraction. Corrosion behavior was analyzed by using weight loss rate and gas collection. Electrochemical characterizations revealed that the T4-deep cryogenic sample displayed the strongest corrosion resistance among all of the samples. A new square phase was discovered in the microstructure of the T6-deep cryogenic sample; this phase was hugely responsible for the corrosion property. Cryogenic treatment significantly improved the corrosion resistance of Mg-7Y-1.5Nd alloy

Polyaspartic acid as a corrosion inhibitor for WE43 magnesium alloy

AbstractThe inhibition behavior of polyaspartic acid (PASP) as an environment-friendly corrosion inhibitor for WE43 magnesium alloy was investigated in 3.5 wt.% NaCl solution by means for EIS measurement, potentiodynamic polarization curve, and scanning electron microscopy. The results show that PASP can inhibit the corrosion of WE43 magnesium alloy. The maximum inhibition efficiency is achieved when PASP concentration is 400 ppm in this study

Tai chi for overweight/obese adolescent and young women with polycystic ovary syndrome: study protocol for a randomized controlled trial

Abstract Background Tai Chi is a moderately intense exercise that dates back to ancient China. It has been reported that Tai Chi not only has beneficial effects on metabolic disorders, such as diabetes, cardiovascular diseases and obesity, but also has favorable effects on psychological well-being. Since these conditions are quite closely associated with polycystic ovary syndrome (PCOS), we hypothesis that Tai Chi could be a potential treatment option for PCOS patients. We aim to determine the feasibility and effectiveness of Tai Chi on overweight/obese adolescent and young women with PCOS. Methods A total of 50 patients will be randomized into two arms: (1) Tai Chi or (2) self-monitored exercise. Both groups will exercise for 3 months. The primary hypothesis is that Tai Chi results in a significantly lower Body Mass Index (BMI) than self-monitored exercise. The study was approved by the Ethics Committee of the First Affiliated Hospital of Heilongjiang University of Chinese Medicine. Discussion This is the first study to determine the feasibility and effectiveness of Tai Chi in treating overweight/obese adolescent and young women with PCOS. The trial will provide evidence to assess the feasibility of a future multicenter, randomized controlled trial. Trial registration ClinicalTrials.gov, ID: NCT02608554. Registered on 17 November 2015

A Millimeter-Wave Broadband Multi-Mode Substrate-Integrated Gap Waveguide Traveling-Wave Antenna with Orbit Angular Momentum

Orbit angular momentum (OAM) has been considered a new dimension for improving channel capacity in recent years. In this paper, a millimeter-wave broadband multi-mode waveguide traveling-wave antenna with OAM is proposed by innovatively utilizing the transmitted electromagnetic waves (EMWs) characteristic of substrate-integrated gap waveguides (SIGWs) to introduce phase delay, resulting in coupling to the radiate units with a phase jump. Nine “L”-shaped slot radiate elements are cut in a circular order at a certain angle on the SIGW to generate spin angular momentum (SAM) and OAM. To generate more OAM modes and match the antenna, four “Π”-shaped slot radiate units with a 90° relationship to each other are designed in this circular array. The simulation results show that the antenna operates at 28 GHz, with a −10 dB fractional bandwidth (FBW) = 35.7%, ranging from 25.50 to 35.85 GHz and a VSWR ≤ 1.5 dB from 28.60 to 32.0 GHz and 28.60 to 32.0 GHz. The antenna radiates a linear polarization (LP) mode with a gain of 9.3 dBi at 34.0~37.2 GHz, a l = 2 SAM–OAM (i.e., circular polarization OAM (CP–OAM)) mode with 8.04 dBi at 25.90~28.08 GHz, a l = 1 and l = 2 hybrid OAM mode with 5.7 dBi at 28.08~29.67 GHz, a SAM (i.e., left/right hand circular polarization (L/RHCP) mode with 4.6 dBi at 29.67~30.41 GHz, and a LP mode at 30.41~35.85 GHz. In addition, the waveguide transmits energy with a bandwidth ranging from 26.10 to 38.46 GHz. Within the in-band, only a quasi-TEM mode is transmitted with an energy transmission loss |S21| ≤ 2 dB

HDAC5 inhibits ovarian angiogenesis in dehydroepiandrosterone-induced mouse model of polycystic ovary syndrome

Introduction. Abnormal ovarian angiogenesis is a common feature of polycystic ovary syndrome (PCOS), a typical endocrine disorder affecting women of reproductive age. Histone deacetylase 5 (HDAC5) has been documented as a suppressor of angiogenesis. The aim of this study was to explore the effect of HDAC5 on ovarian angiogenesis in a PCOS mouse model.Material and methods. PCOS was induced in female C57BL/6 mice by 20-day administration of dehydroepiandrosterone (DHEA). HDAC5 was over-expressed in PCOS mice by corresponding adenovirus injection. In total, 120 mice were used in this study. Western-blotting, real-time PCR, hematoxylin and eosin staining, enzyme-linked immunosorbent assay (ELISA), immunohistochemical staining, flow cytometry, and co-immunoprecipitation were respectively used to evaluate the effect of HDAC5 on PCOS mice.Results. PCOS ovaries showed a compensatory increase in HDAC5 expression, while HDAC5 over-expression alleviated abnormalities in ovarian morphology and serum hormone levels after PCOS modeling. HDAC5 inhibited ovarian angiogenesis in PCOS mice by regulating angiogenesis-related factors, such as VEGFA, platelet-derived growth factors B and D (PDGFB/D), and angiopoietins 1 and 2 (ANGPT1/2) and CD31. HDAC5 over-expression decreased levels of reactive oxygen species (ROS) and malondialdehyde, while promoting activities of catalase and superoxide dismutase in ovaries of PCOS mice, suggesting its suppressive effects on oxidative stress, an inducer of uncontrolled angiogenesis. Moreover, HDAC5 suppressed activation of angiogenesis-related HIF-1α/VEGFA/VEGFR2 signaling in PCOS ovaries partly via inhibiting VEGFR2 acetylation.Conclusions. This study reveals the protective role of HDAC5 in PCOS by inhibiting ovarian angiogenesis and provides a molecular candidate for PCOS therapy in the future

improved mobile robot's corridor-scene classifier based on probabilistic spiking neuron model

The ability of cognition and recognition for complex environment is very important for a real autonomous robot. A improved Corridor-Scene-Classifier based on probabilistic Spiking Neuron Model(pSNM) for mobile robot is designed. In the SNN classifier, the model pSNM is used. As network's training, Thorpe's learning rule is used. The experimental results show that the improved Classifier is more effective and it also has stronger robustness than the previous classifier based on Integrated-and-Fire (IAF) spiking neuron model for the structural corridor-scene. It also has better robustness than the traditional kernel-pca and the BP Corridor-Scene-classifier. © 2011 IEEE.IEEE; IEEE Computer Society (CS); IEEE Computational Intelligence Society (CIS); University of Calgary; The IEEE ICCI Steering CommitteeThe ability of cognition and recognition for complex environment is very important for a real autonomous robot. A improved Corridor-Scene-Classifier based on probabilistic Spiking Neuron Model(pSNM) for mobile robot is designed. In the SNN classifier, the model pSNM is used. As network's training, Thorpe's learning rule is used. The experimental results show that the improved Classifier is more effective and it also has stronger robustness than the previous classifier based on Integrated-and-Fire (IAF) spiking neuron model for the structural corridor-scene. It also has better robustness than the traditional kernel-pca and the BP Corridor-Scene-classifier. © 2011 IEEE