Resource Allocation for Device-to-Device Communications in Multi-Cell Multi-Band Heterogeneous Cellular Networks

Heterogeneous cellular networks (HCNs) with millimeter wave (mm-wave) communications are considered as a promising technology for the fifth generation mobile networks. Mm-wave has the potential to provide multiple gigabit data rate due to the broad spectrum. Unfortunately, additional free space path loss is also caused by the high carrier frequency. On the other hand, mm-wave signals are sensitive to obstacles and more vulnerable to blocking effects. To address this issue, highly directional narrow beams are utilized in mm-wave networks. Additionally, device-to-device (D2D) users make full use of their proximity and share uplink spectrum resources in HCNs to increase the spectrum efficiency and network capacity. Towards the caused complex interferences, the combination of D2D-enabled HCNs with small cells densely deployed and mm-wave communications poses a big challenge to the resource allocation problems. In this paper, we formulate the optimization problem of D2D communication spectrum resource allocation among multiple micro-wave bands and multiple mm-wave bands in HCNs. Then, considering the totally different propagation conditions on the two bands, a heuristic algorithm is proposed to maximize the system transmission rate and approximate the solutions with sufficient accuracies. Compared with other practical schemes, we carry out extensive simulations with different system parameters, and demonstrate the superior performance of the proposed scheme. In addition, the optimality and complexity are simulated to further verify effectiveness and efficiency.Comment: 13 pages, 11 figures, IEEE Transactions on Vehicular Technolog

Kinematics analysis and optimization of the exoskeleton’s knee joint

Two major defects of the exoskeleton’s single-axis knee joint were exposed in human-machine coordination experiments, which are chattering of hip and knee joints and pull-feeling at ankle joint. In order to analyze and solve these issues, human gait experiments were conducted to obtain the human gait data, and a kinematic model of the exoskeleton was established. Kinematics analysis of the exoskeleton based on the human’s hip and knee joint angles indicated the obvious human-machine ankle joint movement error; inverse kinematics analysis of the exoskeleton according to the human ankle joint trajectory reflected the abrupt angle changes of exoskeleton’s hip and knee joints. According to these analysis results, kinematics differences between the exoskeleton’s single-axis knee joint and human’s trochlea knee joint were regarded as the primary cause of the defects observed in human-machine coordination experiments. The exoskeleton’s knee joint was optimized in four-bar linkage type to imitate the kinematics characteristics of human’s knee joint. Kinematics simulation results of the optimized exoskeleton showed that human-machine ankle joint movement error and abrupt angle changes of the exoskeleton’s hip and knee joints have been both significantly reduced, thus the effectiveness of the exoskeleton’s knee joint optimization for improving the human-machine coordination could be confirmed

Id2 promotes the invasive growth of MCF-7 and SKOV-3 cells by a novel mechanism independent of dimerization to basic helix-loop-helix factors

<p>Abstract</p> <p>Background</p> <p>Inhibitor of differentiation 2 (<it>Id2</it>) is a critical factor for cell proliferation and differentiation in normal vertebrate development. Most of the biological function of Id2 has been ascribed to its helix-loop-helix motif. Overexpression of Id2 is frequently observed in various human tumors, but its role for invasion potential in tumor cells is dispute. We aimed to reveal the role of Id2 in invasion potential in poorly invasive and estrogen receptor α (ERα)-positive MCF-7 and SKOV-3 cancer cells.</p> <p>Methods</p> <p>MCF-7 and SKOV-3 cells were stably transfected with the wild-type, degradation-resistant full-length or helix-loop-helix (HLH)-deleted Id2, respectively. Protein levels of Id2 and its mutants and E-cadherin were determined by western blot analysis and mRNA levels of Id2 and its mutants were determined by RT-PCR. The effects of Id2 and its mutants on cell proliferation were determined by [³H]-thymidine incorporation assay and the 3- [4, 5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) dye method. The <it>in vitro </it>invasion potential of cells was evaluated by Transwell assay. Cell motility was assessed by scratch wound assay. The promoter activity of <it>E-cadherin </it>was determined by cotransfection and luciferase assays.</p> <p>Results</p> <p>Ectopic transfection of the wild-type Id2 markedly increased the protein and mRNA expression of <it>Id2 </it>in MCF-7 and SKOV-3 cells; the protein level but not mRNA level was further increased by transfection with the degradation-resistant Id2 form. The ectopic expression of Id2 or its mutants did not alter proliferation of either MCF-7 or SKOV-3 cells. Transfection of the wild-type Id2 significantly induced the invasion potential and migratory capacity of cells, which was further augmented by transfection with the degradation-resistant full-length or HLH-deleted Id2. E-cadherin protein expression and transactivation of the proximal E-cadherin promoter were markedly suppressed by the degradation-resistant full-length or HLH-deleted Id2 but not wild-type Id2. Ectopic expression of E-cadherin in MCF-7 and SKOV-3 cells only partially blunted the invasion potential induced by the degradation-resistant HLH-deleted Id2.</p> <p>Conclusion</p> <p>Overexpression of Id2 in ERα-positive epithelial tumor cells indeed increases the cells' invasive potential through a novel mechanism independent of dimerization to basic helix-loop-helix factors. E-cadherin contributes only in part to Id2-induced cell invasion when Id2 is accumulated to a higher level in some specific cell types.</p

MM-3DScene: 3D Scene Understanding by Customizing Masked Modeling with Informative-Preserved Reconstruction and Self-Distilled Consistency

Masked Modeling (MM) has demonstrated widespread success in various vision challenges, by reconstructing masked visual patches. Yet, applying MM for large-scale 3D scenes remains an open problem due to the data sparsity and scene complexity. The conventional random masking paradigm used in 2D images often causes a high risk of ambiguity when recovering the masked region of 3D scenes. To this end, we propose a novel informative-preserved reconstruction, which explores local statistics to discover and preserve the representative structured points, effectively enhancing the pretext masking task for 3D scene understanding. Integrated with a progressive reconstruction manner, our method can concentrate on modeling regional geometry and enjoy less ambiguity for masked reconstruction. Besides, such scenes with progressive masking ratios can also serve to self-distill their intrinsic spatial consistency, requiring to learn the consistent representations from unmasked areas. By elegantly combining informative-preserved reconstruction on masked areas and consistency self-distillation from unmasked areas, a unified framework called MM-3DScene is yielded. We conduct comprehensive experiments on a host of downstream tasks. The consistent improvement (e.g., +6.1 [email protected] on object detection and +2.2% mIoU on semantic segmentation) demonstrates the superiority of our approach

Efficacy of a smartphone-based care support programme in improving post-traumatic stress in families with childhood cancer: Protocol of a randomised controlled trial

INTRODUCTION: Diagnosis and treatment represent distressing experiences for the families of children with cancer. Psychosocial challenges are faced by these families in China because of limited health services and resources for psychosocial oncology care. Effective interventions tailored to the knowledge level and cultural values of this population are needed. The goal of this study is to evaluate a smartphone-based care support (SBCS) programme for the families of children with cancer in China. METHODS AND ANALYSIS: A parallel randomised controlled trial will be conducted to examine the efficacy of an evidence-based and culturally tailored SBCS programme for the families of children with cancer in China. A total of 180 families will be recruited. The intervention will consist of an introduction session and four main sessions and will be conducted sequentially on a single weekend day. Participating families will be included in the intervention group. The post-traumatic stress and quality of life of families will be evaluated at baseline, during the intervention, immediately after the intervention, and 2 and 6 months after the intervention. ETHICS AND DISSEMINATION: Ethical approval for this protocol has been obtained from the Nursing and Behavioural Medicine Research Ethics Review Committee, Xiangya School of Nursing, Central South University (Protocol #: E2020125). The findings of the trial will be disseminated through conference presentations and publications in peer-reviewed journals. TRIAL REGISTRATION NUMBER: ChiCTR2000040510

MD2 activation by direct AGE interaction drives inflammatory diabetic cardiomyopathy

Hyperglycemia activates toll-like receptor 4 (TLR4) to induce inflammation in diabetic cardiomyopathy (DCM). However, the mechanisms of TLR4 activation remain unclear. Here we examine the role of myeloid differentiation 2 (MD2), a co-receptor of TLR4, in high glucose (HG)- and diabetes-induced inflammatory cardiomyopathy. We show increased MD2 in heart tissues of diabetic mice and serum of human diabetic subjects. MD2 deficiency in mice inhibits TLR4 pathway activation, which correlates with reduced myocardial remodeling and improved cardiac function. Mechanistically, we show that HG induces extracellular advanced glycation end products (AGEs), which bind directly to MD2, leading to formation of AGEs-MD2-TLR4 complex and initiation of pro-inflammatory pathways. We further detect elevated AGE-MD2 complexes in heart tissues and serum of diabetic mice and human subjects with DCM. In summary, we uncover a new mechanism of HG-induced inflammatory responses and myocardial injury, in which AGE products directly bind MD2 to drive inflammatory DCM

Fluctuating levels of reprogramming factor expression in cultured human undifferentiated keratinocytes

Although human undifferentiated keratinocytes (HUKs) can be reprogrammed to become induced pluripotent stem cells (iPSCs) with high efficiency and rapid kinetics by transducing reprogramming factors (RFs), the endogenous expression of reprogramming factors in cultured HUKs is not clear at different stages. In this study, keratinocytes were isolated from foreskin of adult subject (18 years old) and cultured on collagen type IV-coated culture dishes in a low-calcium, serum-free medium (Epilife, Invitrogen). In order to clarify the expression patterns of RFs and other stem cell markers in cultured human keratinocytes, total RNA was extracted using Trizol reagent, and polymerase chain reaction (PCR) was performed using established GenBank sequences to design primers. The subsequent PCR analysis was carried out by agarose gel electrophoresis. The expression levels of RFs and other stem cell markers in human HUKs clearly fluctuated during culturing, which supports the hypothesis that HUKs might be reprogrammed into a pluripotent state when the maximum levels of RFs expression are maintained by appropriate culture conditions.Keywords: Human undifferentiated keratinocytes, reprogramming factors, expression fluctuationAfrican Journal of Biotechnology Vol. 12(35), pp. 5389-539