Harmonic active mode-locking optoelectronic oscillator with suppressed supermode noise based on pulse intensity feedback.

A harmonic active mode-locking optoelectronic oscillator (HAML-OEO) with pulse intensity feedback is proposed and experimentally demonstrated. It is capable of generating microwave pulses characterized by suppressed supermode noise, uniform intensity, and tunable repetition rates. Unlike traditional HAML-OEOs, active mode-locking and pulse intensity feedback are simultaneously achieved through the use of a dual-drive Mach-Zehnder modulator (DDMZM). By synchronously feeding back the generated microwave pulses to the DDMZM, each pulse undergoes a loss proportional to its intensity, facilitating pulse intensity equalization and supermode noise suppression. In the experiment, intensity-equalized microwave pulse trains with repetition rates of 499 kHz and 998 kHz are generated by the 5th- and 10th-order HAML-OEOs, respectively, with the measured supermode noise suppression ratios exceeding 40 dB.

Correlation Between Preoperative and Postoperative Alignment and Kinematic Gait in Total Knee Arthroplasty.

Objective: Maintaining the lower limb in a neutral posture following total knee arthroplasty (TKA) has long been a concept maintained by operators. This study aimed to investigate the relationship between changes in lower limb alignment and the dynamics of knee gait before and after TKA to understand the impact of alignment on gait better and offer a theoretical foundation for correcting lower limb alignment in TKA. Methods: Our study included a group of 20 participants. The cohort consisted of 1 male and 19 females, 11 left and 9 right knees, ages 58 to 81. Using the Opti_Knee® Knee Motion Test System with infrared reflective markers and a high-speed camera, the step length and 6 degrees of freedom of the knee were recorded. Following that, we investigated the association between HKA angle and knee kinematic gait before and after surgery. Results: For preoperative HKA angles ranging from -28° to -3°, we observed increased step length, flexion-extension rotation, and varus-valgus rotation with an increase in HKA angle. Conversely, an increase in HKA angle from -3 ° to 15° corresponded with decreased step length, flexion-extension rotation, and varus-valgus rotation. An increase in HKA angle from 1° to 3° postoperatively increased step length, flexion-extension rotation, and varus-valgus rotation. In contrast, increasing the HKA angle from 3° to 5° resulted in less flexion-extension rotation. The flexion-extension rotation was at its maximum when the HKA angle was 3°. A 3° postoperative varus resulted in improved kinematic gait. Step length, varus-valgus rotation, and flexion-extension rotation increased with increasing HKA angle in the neutral alignment group. In contrast, the non-neutral alignment group exhibited decreased flexion-extension rotation as the HKA angle increased, while step length and varus-valgus rotation increased as the HKA angle increased. The varus-valgus rotation was statistically significant (P < .05) in the preoperative versus early postoperative period in the 6 degrees of freedom. Conclusions: A 3° varus alignment was found to have a superior postoperative knee kinematic gait, implying that a 3° varus alignment may be more suitable as a new gold standard for TKA than the traditional "0°" alignment. The neutral alignment group demonstrated a better knee kinematic gait than the non-neutral alignment group. During early postoperative walking, significant improvements in varus-valgus rotation were found in the 6 degrees of knee freedom.

Blahut-Arimoto Algorithms for Inner and Outer Bounds on Capacity Regions of Broadcast Channels.

The celebrated Blahut-Arimoto algorithm computes the capacity of a discrete memoryless point-to-point channel by alternately maximizing the objective function of a maximization problem. This algorithm has been applied to degraded broadcast channels, in which the supporting hyperplanes of the capacity region are again cast as maximization problems. In this work, we consider general broadcast channels and extend this algorithm to compute inner and outer bounds on the capacity regions. Our main contributions are as follows: first, we show that the optimization problems are max-min problems and that the exchange of minimum and maximum holds; second, we design Blahut-Arimoto algorithms for the maximization part and gradient descent algorithms for the minimization part; third, we provide convergence analysis for both parts. Numerical experiments validate the effectiveness of our algorithms.

[Effects of humic acid water-soluble fertilizer on growth and physiological characteristics of Bupleurum chinense seedlings].

The effects of humic acid water-soluble fertilizer on the growth and physiological characteristics of Bupleurum chinense seedlings(Zhongchai No.1) were studied by using a single factor experiment design. When the seedling age was 60 days, the humic acid water-soluble fertilizer was diluted 1 200 times(T1), 1 500 times(T2), 1 800 times(T3), and 2 100 times(T4) for seedling treatment, respectively, and water was used as the control(CK). The effects of different treatments on growth indexes, biomass accumulation, root activity, antioxidant enzyme activity, membrane lipid peroxidation, and photosynthetic characteristics of B. chinense seedlings were analyzed after 30 days. The results showed that compared with CK, stem height, leaf number, root diameter, and root length of the B. chinense seedlings under T3 treatment were significantly increased by 36.82%, 37.03%, 42.78%, and 22.38%, respectively. Root fresh weight, leaf fresh weight, root dry weight, and leaf dry weight under T3 treatment were significantly increased by 90.36%, 98.68%, 123.84%, and 104.38%, respectively. In addition, humic acid water-soluble fertilizer also enhanced TTC reducing activity of the root of B. chinense seedlings, inhibited malonaldehyde(MDA) content, increased superoxide dismutase(SOD), peroxidase(POD), and catalase(CAT) enzyme activities, improved chlorophyll content, and enhanced P_n, G_s, T_r, and other photosynthetic parameters. In conclusion, the application of humic acid water-soluble fertilizer diluted 1 800 times can significantly promote the growth of B. chinense seedlings, enhance root vitality, improve seedling stress resistance, and enhance photosynthesis. The results of this study can provide a theoretical basis for fertilization of B. chinense seedlings.

Energy-efficient subchannel assignment and power allocation in VLC-IoT systems with SLIPT.

In this paper, we investigate joint subchannel assignment and power allocation for the energy efficiency (EE) optimization in an indoor visible light communication (VLC)-Internet of Things (IoT) system with simultaneous lightwave information and power transfer (SLIPT). A mixed-integer fractional nonlinear programming problem that is challenging to solve is formulated. To tackle this problem, the optimal transmission scheme is decomposed into subchannel assignment and power allocation. Firstly, a virtual cell formation and subchannel assignment (VCF-SA) scheme is proposed, which considers the location of IoT devices, quality of service requirements, and energy states. Secondly, a quadratic transformation-based power allocation (QTBPA) scheme is designed to transform the fractional nonlinear programming problem into a series of convex problems that can be solved iteratively. Simulation results illustrate the effectiveness of the proposed scheme in terms of system EE compared to the benchmarks. The impact of system parameters on the EE is also analyzed.

Biotemplate Fabrication of Hollow Tubular CexSr1-xTiO3 with Regulable Surface Acidity and Oxygen Mobility for Efficient Destruction of Chlorobenzene: Intrinsic Synergy Effect and Reaction Mechanism.

Developing economic and applicable catalysts with elegant chlorine resistance and organic byproduct inhibition capability is of great significance for chlorinated volatile organic compounds (Cl-VOCs) eco-friendly purification. Here, ternary CexSr1-xTiO3 catalysts with tunable surface acidity and oxygen species mobility were creatively fabricated using the hollow tubular-structured fruit hair of Platanus (FHP; a widespread greenery waste) as the scaffolding biotemplate. It is shown that the oxygen vacancy (Ov) triggered by the presence of Ce can optimize the synergy between the Lewis acid sites (LAS) and Brønsted acid sites (BAS). High concentration of Ov and BAS promotes the C-Cl cleavage of chlorobenzene (CB) and accelerates the desorption of Cl• radicals as inorganic chlorine. Simultaneously, the strong electron transfer within Ti-Ce-Sr linkage increases the acidity of LAS, resulting in the superior reducibility of Ce0.4Sr0.6TiO3 and facilitating the deep oxidation of dechlorination intermediates. Additionally, the spatial confinement of the tubular structure remarkably accelerates the CB flow rate and reduces the residence time of byproducts over the prepared catalysts. Owing to these, CB can be efficiently destructed over Ce0.4Sr0.6TiO3 with selectivity of CO2 and inorganic chlorine dramatically enhanced, respectively, approximately 16 and 21 times at 275 °C compared to those of pure SrTiO3. The present work provides a feasible and promising strategy for engineering efficient catalysts for heterogeneous thermocatalytic reactions for industrial-scale Cl-CVOC destruction.

The root microbiome: Community assembly and its contributions to plant fitness.

The root microbiome refers to the community of microbes living in association with a plant's roots, and includes mutualists, pathogens, and commensals. Here we focus on recent advances in the study of root commensal community which is the major research object of microbiome-related researches. With the rapid development of new technologies, plant-commensal interactions can be explored with unprecedented breadth and depth. Both the soil environment and the host plant drive commensal community assembly. The bulk soil is the seed bank of potential commensals, and plants use root exudates and immune responses to build healthy microbial communities from the available microbes. The plant microbiome extends the functional system of plants by participating in a variety of processes, including nutrient absorption, growth promotion, and resistance to biotic and abiotic stresses. Plants and their microbiomes have evolved adaptation strategies over time. However, there is still a huge gap in our understanding of the regulatory mechanisms of plant-commensal interactions. In this review, we summarize recent research on the assembly of root microbial communities and the effects of these communities on plant growth and development, and look at the prospects for promoting sustainable agricultural development through the study of the root microbiome.

Structural Entropy of the Stochastic Block Models.

With the rapid expansion of graphs and networks and the growing magnitude of data from all areas of science, effective treatment and compression schemes of context-dependent data is extremely desirable. A particularly interesting direction is to compress the data while keeping the "structural information" only and ignoring the concrete labelings. Under this direction, Choi and Szpankowski introduced the structures (unlabeled graphs) which allowed them to compute the structural entropy of the Erdos-Rényi random graph model. Moreover, they also provided an asymptotically optimal compression algorithm that (asymptotically) achieves this entropy limit and runs in expectation in linear time. In this paper, we consider the stochastic block models with an arbitrary number of parts. Indeed, we define a partitioned structural entropy for stochastic block models, which generalizes the structural entropy for unlabeled graphs and encodes the partition information as well. We then compute the partitioned structural entropy of the stochastic block models, and provide a compression scheme that asymptotically achieves this entropy limit.

The novel GLP-1/GIP dual agonist DA3-CH is more effective than liraglutide in reducing endoplasmic reticulum stress in diabetic rats with cerebral ischemia-reperfusion injury.

BACKGROUND AND AIMS: Diabetes is one of the most important risk factors and comorbidities of ischemic stroke. Endoplasmic reticulum stress (ERS) is considered to be the major injury mechanism of ischemic stroke with diabetes. Studies have found that incretin can inhibit ERS in ischemia-reperfusion injury of the liver and heart. We aimed to explore the effects of GLP-1/GIP double agonist DA3-CH and GLP-1 single agonist liraglutide on ERS and apoptosis in diabetic rats with cerebral ischemia-reperfusion injury. METHODS AND RESULTS: 72 Sprague-Dawley (SD) male rats were randomly divided into 4 groups: ① blank group (Sham group, n = 18); model group (Saline group, n = 18); DA3 treatment group (DA3 group, n = 18); liraglutide treatment group (Lir group, n = 18). The Sham group was not given any treatment and was only raised in the same environment as the other groups. The remaining 3 groups used STZ-induced diabetes models. After the successful membrane formation of diabetes, DA3-CH and liraglutide (10 mmol/kg, once-daily for 14 days) were injected intraperitoneally. Thereafter, rats were subjected to middle cerebral artery occlusion followed by 24-h reperfusion. Animals were evaluated for neurologic deficit score, infarct volume, and biomarker analyses of the brain after ischemia. The DA3-CH-treated and liraglutide-treated groups showed significantly reduced scores of neurological dysfunction and cerebral infarction size, and reduced the expression of ERS markers GRP78, CHOP and Caspase-12, and the expression of apoptosis marker bax. Anti-apoptotic markers bcl-2 and neuronal numbers increased significantly. CONCLUSIONS: DA3-CH and liraglutide have obvious neuroprotective effects in a rat model of cerebral ischemia-reperfusion injury with diabetes, which can reduce the infarct size and the neurological deficit score. Their exert neuroprotective effects in a rat model of cerebral ischemia-reperfusion injury with diabetes by inhibiting endoplasmic reticulum stress and thereby reducing apoptosis. DA3 is better than liraglutide.

Health-related quality of life after first-ever acute ischemic stroke: associations with cardiovascular health metrics.

PURPOSE: To investigate the associations between cardiovascular health (CVH) metrics and health-related quality of life (HRQL) among patients with ischemic stroke in China, and further explore the role of physical and cognitive function in their associations. METHODS: This hospital-based study included 1714 patients with first-ever acute ischemic stroke (age ≥ 40 years; 36.7% women) who were admitted to two university hospitals in Shandong, China. We collected information on seven CVH metrics (smoking, body mass index, diet, physical activity, blood pressure, total cholesterol, and fasting blood glucose) through interviews, clinical examinations, and laboratory tests. EQ-5D-3L was used to assess HRQL. Cognitive and physical functioning was assessed by the Montreal Cognitive Assessment test and Barthel index, respectively. Data were analyzed using the general linear regression models. RESULTS: The average score (SD) was 0.746 (0.23) for HRQL index and 72.7 (15.8) for self-rated health. Optimal levels of four individual CVH metric components (diet, physical activity, blood pressure, and blood glucose) and a higher composite CVH score were significantly associated with a greater HRQL index and better self-rated health (p < 0.05 for all). Physical dependence and cognitive impairment were associated with a lower HRQL index and poorer self-rated health status (p < 0.001). Furthermore, the relationships between CVH metrics and HRQL index varied by functional status, such that their associations were statistically significant only among people who had physical dependence or cognitive impairment. CONCLUSION: Achieving a better cardiovascular health profile is associated with better quality of life among ischemic stroke survivors, primarily in those with physical or cognitive impairment.

Methylated mud snail protein as a bio-flocculant for high turbidity wastewater treatment.

The authors reported a potential candidate methylated mud snail protein (MeMsp) as an effective and eco-friendly flocculant to treat the high turbidity wastewater. MeMsp was obtained by extraction of mud snail protein (Msp) through isoelectric precipitation (PSC-IP) and then methylated via the esterification with side-chain carboxyl. Structural characterization of FT-IR, zeta potential and elemental analysis were carried out and further confirmed the successful of the methylation. Flocculation experiments with kaolin suspension simulated wastewater indicated that MeMsp-24 displayed more excellent flocculation efficiency at a low dosage. At the optimum dosage 27 mg/L, the maximum clarification efficiency of MeMsp-24 was 97.46% under pH 7.0. Furthermore, MeMsp-24 exhibited a wide flocculation window in the pH range 1.0-9.0, and faster sedimentation velocity and larger flocs size. In addition, MeMsp-24 exhibited 92.12% clarification efficiency in treating railway tunnel construction effluent. The flocculation kinetic and mechanism analysis revealed that the most effective particle collision occurred at the optimal dosage, with charge neutralization and adhesion playing irreplaceable roles in different environments, respectively. Therefore, through extraction and methylation modification, MeMsp could be a promising eco-friendly flocculant for high turbidity wastewater treatment.

The pregnancy-associated spontaneous coronary artery dissection in a young woman with a novel missense mutation in NOTCH1: a case report.

BACKGROUND: Spontaneous coronary artery dissection (SCAD) is frequently reported as a disorder that primarily affects women without risk factors for cardiovascular disease. Although it has been recognized as one of the genetically mediated vascular disorders, the genetic pathogenesis of SCAD remains obscure to date. CASE PRESENTATION: In this report, we presented a rare case of pregnancy-associated SCAD in a young woman that occurred in multiple coronary arteries within a short period. The initial conservative management and then intravascular ultrasound-guided primary percutaneous coronary intervention (PCI) were adopted to achieve optimal results of revascularization in affected coronary arteries and avoid potential risks for PCI-associated complications. We further performed the whole-exome sequencing and Sanger sequencing and, for the first time, reported a novel heterozygous missense variant, c.4574 C > T (p.Arg1438Cys), in the NOTCH1 gene. This variant has never been documented in the medical literature and was predicted as being potentially damaging or disease-causing variant. CONCLUSIONS: We described a rare case of recurrent SCAD in a young woman after baby delivery. The initial conservative management and PCI with multiple stent implantations were successfully implemented to achieve optimal results of revascularization in coronary arteries. We, for the first time, identified a novel missense variant in the NOTCH1 gene, which appears to be a potential predisposing factor for artery fragility.

Differences in 1­year outcome after primary total hip and knee arthroplasty : A cohort study in older patients with osteoarthritis.

BACKGROUND: Patients who undergo primary total hip (THA) and knee (TKA) arthroplasty show better clinical outcomes, improved quality of life and increased participation in leisure activities; however, the differences between primary THA and TKA in older patients are unknown. OBJECTIVE: The aim of the study was to compare the Western Ontario and McMasters University osteoarthritis index (WOMAC) scores and changes in WOMAC scores, the Medical Outcomes study 12-item short-form version 2 (SF-12) mental and physical health scales, satisfaction and frequency of participation in leisure activities in older osteoarthritis patients with a mean age of 67.9 ± 10.6 years who underwent primary THA and TKA. MATERIAL AND METHODS: Data from 170 THA and 169 TKA patients were collected 1 week preoperatively through self-reporting of WOMAC scores and SF-12. These parameters, level of satisfaction and frequency of participation in leisure activities were collected 1 year postoperatively by self-reporting questionnaires. RESULTS: The THA group of patients showed better WOMAC scores (P < 0.05), changes in WOMAC scores (P < 0.05), physical component summary (PCS) of SF-12 (P < 0.01) and changes in PCS scores (P < 0.01) compared with the TKA group. In addition, the THA patients showed higher overall satisfaction (91.90% vs. 83.60%), pain relief satisfaction (87.20% vs. 77.40%) and functional improvement satisfaction (90.10% vs. 83.08%) in comparison with the TKA patients. Furthermore, a higher frequency of participation in leisure activities was achieved in THA patients, except for intellectual leisure activities. CONCLUSION: These findings suggest that primary THA provides superior clinical outcomes, quality of life, satisfaction, and participation in leisure activities compared with primary TKA in older patients.

Dual-agonist occupancy of orexin receptor 1 and cholecystokinin A receptor heterodimers decreases G-protein-dependent signaling and migration in the human colon cancer cell line HT-29.

The orexin (OX1R) and cholecystokinin A (CCK1R) receptors play opposing roles in the migration of the human colon cancer cell line HT-29, and may be involved in the pathogenesis and pathophysiology of cancer cell invasion and metastasis. OX1R and CCK1R belong to family A of the G-protein-coupled receptors (GPCRs), but the detailed mechanisms underlying their functions in solid tumor development remain unclear. In this study, we investigated whether these two receptors heterodimerize, and the results revealed novel signal transduction mechanisms. Bioluminescence and Förster resonance energy transfer, as well as proximity ligation assays, demonstrated that OX1R and CCK1R heterodimerize in HEK293 and HT-29 cells, and that peptides corresponding to transmembrane domain 5 of OX1R impaired heterodimer formation. Stimulation of OX1R and CCK1R heterodimers with both orexin-A and CCK decreased the activation of Gαq, Gαi2, Gα12, and Gα13 and the migration of HT-29 cells in comparison with stimulation with orexin-A or CCK alone, but did not alter GPCR interactions with ß-arrestins. These results suggest that OX1R and CCK1R heterodimerization plays an anti-migratory role in human colon cancer cells.

Ex Vivo Evaluation of Hip Fracture Risk by Proximal Femur Geometry and Bone Mineral Density in Elderly Chinese Women.

BACKGROUND The incidence of hip fracture is steadily increasing. We aimed to establish a creative approach to precisely estimate the risk of hip fracture by exploring the relationship between hip fracture and bone mineral density (BMD)/femur geometry. MATERIAL AND METHODS Sixteen samples of cadaveric female proximal femora were randomly selected. Experiments were performed experimental measurement of the femoral neck BMD and geometric parameters (including neck length, neck diameter, head diameter, and neck-shaft angle). In addition, the experimental measurements contain the failure load, which represents the mechanical strength of the femoral neck, and we calculated the correlation coefficient among BMD, geometric parameters, and failure load. RESULTS Significant correlations were discovered between femoral mechanical properties and femoral neck BMD (r=0.792, r²=0.628, P<0.001), trochanteric BMD (r=0.749, r²=0.560, P=0.001), and head diameter (r=0.706, r²=0.499, P=0.002). Multiple linear regression analyses indicated that the best predictor of hip fracture was the combination of femoral neck BMD, head diameter, and neck diameter (r²=0.844, P<0.001). CONCLUSIONS The results confirmed that, compared with BMD alone, the combination of BMD and geometric parameters of proximal femur is a better estimation of hip fracture. The geometry of the proximal femur played an important role in assessing the biomechanical strength of femur. This method greatly assists in predicting the risk of hip fracture in clinical trials and will assist studies on why the incidence of hip fracture varies among races.

Triterpenoids with antioxidant activities from Myricaria squamosa.

A new triterpenoid, namely myricarin C (compound 1), together with three known compounds myricarin A (compound 2) and myricarin B (compound 3), 3α-hydroxy-D-friedoolean-14-en-28-oic acid (compound 4), was isolated from the overground part of Myricaria squamosa. Compound 2 and compound 3 existed in the solution by the form of cis-trans isomers. Their structures were elucidated by means of extensive spectroscopic methods, including 1D-NMR, 2D-NMR, and HR-ESI-MS. The antioxidant properties of all compounds were calculated based on the DPPH radical scavenging activities. Results showed that myricarin A and myricarin C had general antioxidant activities with EC50 values of 40.90 µg/ml, 42.22 µg/ml, respectively, compared to the control, rutin (5.17 µg/ml). The EC50 values of myricarin B was 195.81 µg/ml. Compound 4 had no antioxidant activities.

A green method based on electro-assisted and photo-assisted regeneration for removal of chromium(VI) from aqueous solution.

In general, spent adsorbent is regenerated using high-concentration chemicals. Although chemical regeneration is efficient, it often leads to adsorbent damage and secondary waste. To overcome these problems, electro-assisted and photo-assisted regeneration were proposed in this study for the remediation of hexavalent chromium (Cr(VI)). Filter paper was decorated with polyethylene glycol (PEG) and polypyrrole (PPy) to fabricate a FP/PEG/PPy nanocomposite, which could be used as an adsorbent for Cr(VI) with a high adsorption capacity. Moreover, it could be regenerated by electro-assisted or photo-assisted regeneration to reduce eluent use. As a result, secondary waste could be greatly reduced.

Heterodimerization of the kappa opioid receptor and neurotensin receptor 1 contributes to a novel ß-arrestin-2-biased pathway.

Together with its endogenous ligands (dynorphin), the kappa opioid receptor (KOR) plays an important role in modulating various physiological and pharmacological responses, with a classical G protein-coupled pathway mediating analgesia and non-G protein-dependent pathway, especially the ß-arrestin-dependent pathway, eliciting side effects of dysphoria, aversion, drug-seeking in addicts, or even relapse to addiction. Although mounting evidence has verified a functional overlap between dynorphin/KOR and neurotensin/neurotensin receptor 1 (NTSR1) systems, little is known about direct interaction between the two receptors. Here, we showed that KOR and NTSR1 form a heterodimer that functions as a novel pharmacological entity, and this heterodimer, in turn, brings about a switch in KOR-mediated signal transduction, from G protein-dependent to ß-arrestin-2-dependent. This was simultaneously verified by analyzing a KOR mutant (196th residue) that lost the ability to dimerize with NTSR1. We also found that dual occupancy of the heterodimer forced the ß-arrestin-2-dependent pathway back into Gi protein-dependent signaling, according to KOR activation. These data provide new insights into the interaction between KOR and NTSR1, and the newly discovered role of NTSR1 acting as a switch between G protein- and ß-arrestin-dependent pathways of KOR also suggests a new approach for utilizing pathologically elevated dynorphin/KOR system into full play for its analgesic effect with limited side effects.

Effect of Various Ratios of Co-Cultured ATDC5 Cells and Chondrocytes on the Expression of Cartilaginous Phenotype in Microcavitary Alginate Hydrogel.

The present study introduced a direct co-culture of mouse ATDC5 cells and primary porcine chondrocytes into a microcavitary hydrogel, which possessed advantages in promoting the growth of chondrocytes and retaining the phenotype. These two types of cells were encapsulated with gelatin microspheres in alginate hydrogels in either of the three ratios (3:1, 1:1, or 1:3 of ATDC5 cells to chondrocytes) and cultured in chondrogenic medium for 28 days. Simultaneously, the single encapsulation of ATDC5 cells or chondrocytes was set as a control. Cell Counting Kit-8 (CCK-8), real-time PCR, and immunohistochemistry staining were used to evaluate the effect of various ratios of co-cultured ATDC5 cells and chondrocytes on the expression of the cartilaginous phenotype. The CCK-8 data indicated that the ratio of 3:1 group had an outstanding ability of cell growth. The other results demonstrated that higher the ATDC5 ratios and longer the culture duration, greater the expression of cartilage-specific genes (including type II collagen and aggrecan) and more the synthesized cartilaginous extracellular matrix. Also, the Western blot analysis suggested that p44/42 MAP Kinase was involved in cell proliferation. However, due to the direct co-culture of the two cell types, the underlying mechanism necessitates further investigation. Overall, the co-culture system in microcavitary hydrogel improved the effect of chondrogenesis and exhibited promising strategy for cartilage tissue engineering therapies. J. Cell. Biochem. 118: 3607-3615, 2017. © 2017 Wiley Periodicals, Inc.

Quercetin Inhibits Cell Migration and Invasion in Human Osteosarcoma Cells.

BACKGROUND/AIMS: Osteosarcoma is a malignant tumor associated with high mortality; however, no effective therapies for the disease have been developed. Several studies have focused on elucidating the pathogenesis of osteosarcoma and have aimed to develop novel therapies for the disease. Quercetin is a vital dietary flavonoid that has been shown to have a variety of anticancer effects, as it induces cell cycle arrest, apoptosis, and differentiation and is involved in cell adhesion, metastasis and angiogenesis. Herein, we aimed to investigate the effects of quercetin on osteosarcoma migration and invasion in vitro and in vivo and to explore the molecular mechanisms underlying its effects on osteosarcoma migration and invasion. METHODS: Cell viability, cell cycle activity and cell apoptosis were measured using CCK-8 assay and flow cytometry, and cell migration and invasion were evaluated by wound healing and transwell assays, respectively. The mRNA and protein expression levels of several proteins of interest were assessed by real-time quantitative PCR and western blotting, respectively. Moreover, a nude mouse model of human osteosarcoma lung metastasis was established to assess the anti-metastatic effects of quercetin in vivo. RESULTS: We noted no significant differences in cell cycle activity and apoptosis between HOS and MG63 cells and control cells. Treatment with quercetin significantly attenuated cell migration and invasion in HOS and MG63 cells compared with treatment with control medium. Moreover HIF-1α, VEGF, MMP2, and MMP9 mRNA and protein expression levels were significantly downregulated in HOS cells treated with quercetin compared with HOS cells treated with controls. Additionally, treatment with quercetin attenuated metastatic lung tumor formation and growth in the nude mouse model of osteosarcoma compared with treatment with controls. CONCLUSION: Our findings regarding the inhibitory effects of quercetin on cell migration and invasion suggest that quercetin may have potential as a therapy for human osteosarcoma.