Visual Guided Approach-to-Grasp for Humanoid Robots

Vision based control for robots has been an active area of research for more than 30 years and significant progresses in the theory and application have been reported (Hutchinson et al., 1996; Kragic & Christensen, 2002; Chaumette & Hutchinson, 2006). Vision is a very important non-contact measurement method for robots. Especially in the field of humanoi

Construction of α,α‐disubstituted α‐Amino Acid Derivatives via aza‐Morita‐Baylis‐Hillman Reactions of 2‐Aminoacrylates with Activated Olefins

A useful and convenient strategy for the synthesis of α,α‐disubstituted α‐amino acid (α‐AA) derivatives via aza‐Morita‐Baylis‐Hillman reaction of 2‐aminoacrylates with activated olefins has been developed. A variety of α‐AA derivatives containing an α‐amino tertiary center were synthesized in good to excellent yields. The kinetic profiles and calculated methyl anion affinity (MAA) values were employed to rationalize the reactivities of different Michael acceptors used in the reaction

A Force Sensorless Method for CFRP/Ti Stack Interface Detection during Robotic Orbital Drilling Operations

Drilling carbon fiber reinforced plastics and titanium (CFRP/Ti) stacks is one of the most important activities in aircraft assembly. It is favorable to use different drilling parameters for each layer due to their dissimilar machining properties. However, large aircraft parts with changing profiles lead to variation of thickness along the profiles, which makes it challenging to adapt the cutting parameters for different materials being drilled. This paper proposes a force sensorless method based on cutting force observer for monitoring the thrust force and identifying the drilling material during the drilling process. The cutting force observer, which is the combination of an adaptive disturbance observer and friction force model, is used to estimate the thrust force. An in-process algorithm is developed to monitor the variation of the thrust force for detecting the stack interface between the CFRP and titanium materials. Robotic orbital drilling experiments have been conducted on CFRP/Ti stacks. The estimate error of the cutting force observer was less than 13%, and the stack interface was detected in 0.25 s (or 0.05 mm) before or after the tool transited it. The results show that the proposed method can successfully detect the CFRP/Ti stack interface for the cutting parameters adaptation

Characterization of a Superconducting Microstrip Single-Photon Detector Shunted with an External Resistor

A superconducting microstrip single-photon detector (SMSPD) generally requires a shunt resistor to avoid latching, caused by its high current-carrying capacity and low kinetic inductance. Here, the effect of the shunt resistor on the behaviors of microbridge SMSPDs was investigated. We analyzed the change in equivalent switching current at different shunt resistances in two ways and determined the operating current range using intrinsic dark count rate (iDCR) curves. We observed that the reduction in shunt resistance can increase the operating current range, which helps to improve the internal detection efficiency (IDE) and reduce the iDCR. However, the reduction in the shunt resistance can reduce the pulse amplitude and increase the pulse decay time, which can degrade the timing jitter and count rate performance of the SMSPD. The trends of the experimental results can be qualitatively reproduced using a circuit model for an SMSPD with a shunt resistor, which provides useful information for the selection of shunt resistors. Furthermore, we report the improved detection performance of a helium-ion-irradiated SMSPD shunted with a small resistance of 5.2 {\Omega}. We observed a weak IDE saturation with a bias current at a wavelength up to 2000 nm and a nonlinear relation between detection current and photon energy.Comment: 13 pages, 8 figures, 1 tabl

Distinct Patterns of Interhemispheric Connectivity in Patients With Early- and Late-Onset Alzheimer’s Disease

Background: Early-onset Alzheimer’s disease (EOAD) presents a different clinical profile than late-onset Alzheimer’s disease (LOAD). Neuroimaging studies have demonstrated that patients with EOAD present more atrophy and functional disconnection than LOAD patients. However, it remains unknown whether the interhemispheric functional disconnection or its underlying structural impairment contributes to the different clinical profiles of EOAD and LOAD.Methods: According to the arbitrary cut-off age of 65, we included 22 EOAD patients, 27 LOAD patients and 38 healthy controls (further divided into 21 relatively young and 17 old controls). Participants underwent resting-state functional MRI, diffusion tensor imaging (DTI) and comprehensive neuropsychological assessments. We used voxel-mirrored homotopic connectivity (VMHC) to examine interhemispheric functional connectivity. Then, we calculated the diffusion index based on tract-based spatial statistics (TBSS). Two-sample t-tests were used to assess the interhemispheric connectivity differences between each patient group and its corresponding control group.Results: We found that the EOAD patients had lower VMHC in the hippocampus, parahippocampal gyrus (PHG), superior temporal gyrus (STG) and inferior parietal cortex (IPC) than did controls. Consistently, the EOAD patients exhibited white matter (WM) tract impairment in the posterior regions. On the other hand, the LOAD patients displayed increased VMHC and impaired WM tracts in the frontal region. Correlation analyses showed that VMHC in the IPC was related to executive function in the EOAD patients (r = −0.67, P < 0.05).Conclusion: In contrast to the LOAD patients, patients with EOAD exhibited more widely disrupted interhemispheric functional and structural connectivity, which overlapped well across brain regions. In addition, for the EOAD patients, decreased interhemispheric connectivity related to executive deficits. Our study suggested that different interhemispheric connectivity damage patterns may contribute to the distinct clinical profiles in EOAD and LOAD

PP2A Inhibitors Arrest G2/M Transition Through JNK/Sp1-Dependent Down-Regulation of CDK1 and Autophagy-Dependent Up-Regulation of p21

Protein phosphatase 2A (PP2A) plays an important role in the control of the cell cycle. We previously reported that the PP2A inhibitors, cantharidin and okadaic acid (OA), efficiently repressed the growth of cancer cells. In the present study, we found that PP2A inhibitors arrested the cell cycle at the G2 phase through a mechanism that was dependent on the JNK pathway. Microarrays further showed that PP2A inhibitors induced expression changes in multiple genes that participate in cell cycle transition. To verify whether these expression changes were executed in a PP2A-dependent manner, we targeted the PP2A catalytic subunit (PP2Ac) using siRNA and evaluated gene expression with a microarray. After the cross comparison of these microarray data, we identified that CDK1 was potentially the same target when treated with either PP2A inhibitors or PP2Ac siRNA. In addition, we found that the down-regulation of CDK1 occurred in a JNK-dependent manner. Luciferase reporter gene assays demonstrated that repression of the transcription of CDK1 was executed through the JNK-dependent activation of the Sp1 transcription factor. By constructing deletion mutants of the CDK1 promoter and by using ChIP assays, we identified an element in the CDK1 promoter that responded to the JNK/Sp1 pathway after stimulation with PP2A inhibitors. Cantharidin and OA also up-regulated the expression of p21, an inhibitor of CDK1, via autophagy rather than PP2A/JNK pathway. Thus, this present study found that the PP2A/JNK/Sp1/CDK1 pathway and the autophagy/p21 pathway participated in G2/M cell cycle arrest triggered by PP2A inhibitors

CpG-binding protein CFP1 promotes ovarian cancer cell proliferation by regulating BST2 transcription

Epigenetic alterations have been functionally linked to ovarian cancer development and occurrence. The CXXC zinc finger protein 1 (CFP1) is an epigenetic regulator involved in DNA methylation and histone modification in mammalian cells. However, its role in ovarian cancer cells is unknown. Here, we show that CFP1 protein is highly expressed in human ovarian cancer tissues. Loss of CFP1 inhibited the growth of human ovarian cancer cells, promoted apoptosis, and increased senescence. CFP1 knockdown resulted in reduced levels of SETD1 (a CFP1 partner) and histone H3 trimethylation at the fourth lysine residue (H3K4me3). RNA-sequencing revealed that deletion of CFP1 resulted in mRNA reduction of bone marrow stromal cell antigen 2 (BST2). Bioinformatics analysis and chromatin immunoprecipitation showed that CFP1 binds to the promoter of BST2 and regulates its transcription directly. Overexpression of BST2 rescued the growth inhibitory effect of CFP1 loss. Furthermore, depletion of cullin-RING ubiquitin ligases 4 (CRL4) components ROC1 or CUL4A had significantly inhibited the expression of CFP1 and BST2 similar to MLN4924 treatment that blocked cullin neddylation and inactivated CRL4s. In conclusion, CFP1 promotes ovarian cancer cell proliferation and apoptosis by regulating the transcription of BST2, and the expression of CFP1 was affected by CRL4 ubiquitin ligase complex

Exploration of Potential Roles of a New LOXL2 Splicing Variant Using Network Knowledge in Esophageal Squamous Cell Carcinoma

LOXL2 (lysyl oxidase-like 2), an enzyme that catalyzes oxidative deamination of lysine residue, is upregulated in esophageal squamous cell carcinoma (ESCC). A LOXL2 splice variant LOXL2-e13 and its wild type were overexpressed in ESCC cells followed by microarray analyses. In this study, we explored the potential role and molecular mechanism of LOXL2-e13 based on known protein-protein interactions (PPIs), following microarray analysis of KYSE150 ESCC cells overexpressing a LOXL2 splice variant, denoted by LOXL2-e13, or its wild-type counterpart. The differentially expressed genes (DEGs) of LOXL2-WT and LOXL2-e13 were applied to generate individual PPI subnetworks in which hundreds of DEGs interacted with thousands of other proteins. These two DEG groups were annotated by Functional Annotation Chart analysis in the DAVID bioinformatics database and compared. These results found many specific annotations indicating the potential specific role or mechanism for LOXL2-e13. The DEGs of LOXL2-e13, comparing to its wild type, were prioritized by the Random Walk with Restart algorithm. Several tumor-related genes such as ERO1L, ITGA3, and MAPK8 were found closest to LOXL2-e13. These results provide helpful information for subsequent experimental identification of the specific biological roles and molecular mechanisms of LOXL2-e13. Our study also provides a work flow to identify potential roles of splice variants with large scale data

Identification, evaluation, and application of the genomic-SSR loci in ramie

To provide a theoretical and practical foundation for ramie genetic analysis, simple sequence repeats (SSRs) were identified in the ramie genome and employed in this study. From the 115 369 sequences of a specific-locus amplified fragment library, a type of reduced representation library obtained by high-throughput sequencing, we identified 4774 sequences containing 5064 SSR motifs. SSRs of ramie included repeat motifs with lengths of 1 to 6 nucleotides, and the abundance of each motif type varied greatly. We found that mononucleotide, dinucleotide, and trinucleotide repeat motifs were the most prevalent (95.91%). A total of 98 distinct motif types were detected in the genomic-SSRs of ramie. Of them, The A/T mononucleotide motif was the most abundant, accounting for 41.45% of motifs, followed by AT/TA, accounting for 20.30%. The number of alleles per locus in 31 polymorphic microsatellite loci ranged from 2 to 7, and observed and expected heterozygosities ranged from 0.04 to 1.00 and 0.04 to 0.83, respectively. Furthermore, molecular identity cards (IDs) of the germplasms were constructed employing the ID Analysis 3.0 software. In the current study, the 26 germplasms of ramie can be distinguished by a combination of five SSR primers including Ibg5-5, Ibg3-210, Ibg1-11, Ibg6-468, and Ibg6-481. The allele polymorphisms produced by all SSR primers were used to analyze genetic relationships among the germplasms. The similarity coefficients ranged from 0.41 to 0.88. We found that these 26 germplasms were clustered into five categories using UPGMA, with poor correlation between germplasm and geographical distribution. Our study is the first large-scale SSR identification from ramie genomic sequences. We have further studied the SSR distribution pattern in the ramie genome, and proposed that it is possible to develop SSR loci from genomic data for population genetics studies, linkage mapping, quantitative trait locus mapping, cultivar fingerprinting, and as genetic diversity studies

A case-control study on risk factors of breast cancer in China

Introduction: To screen the risk factors associated with breast cancer among Chinese women in order to evaluate the individual risk of developing breast cancer among women in China. Material and methods: A case-control study on 416 breast cancer patients and 1156 matched controls was conducted in 14 hospitals in 8 provinces of China in 2008. Controls were age- and region-matched to the cases. Clinicians conducted in-person interviews with the subjects to collect information on demographics and suspected risk factors for breast cancer that are known worldwide. Conditional logistic regression was used to derive odds ratios (OR) and 95% confidence intervals (CI) for the associations between risk factors and breast cancer. Results: Compared with matched controls, women with breast cancer were significantly more likely to have higher body mass index (BMI, OR = 4.07, 95% CI; 2.98-5.55), history of benign breast disease (BBD) biopsy (OR = 1.68, 95% CI; 1.19-2.38), older age of menarche (AOM) (OR = 1.41, 95% CI: 107-187), stress anticipation (SA), for grade 1-4, OR = 2.15, 95% CI; 1.26-3.66; for grade 5-9, OR = 3.48, 95% CI; 2.03-5.95) and menopause (OR = 2.22, 95% CI: 1.50-3.282) at the level of p < 0.05. Family history of breast cancer (FHBC) in first-degree relatives (OR = 1.66, 95% CI; 0.77-3.59) and use of oral contraceptives (OC) (OR = 1.59, 95% CI; 0.83-3.05) were associated with an increased risk of breast cancer at the level of p < 0.20. Conclusions: Our results showed that BMI, history of BBD biopsy, older AOM, SA and menopause were associated with increased risk of breast cancer among Chinese women. The findings derived from the study provided some suggestions for population-based prevention and control of breast cancer in China.Medicine, General & InternalSCI(E)15ARTICLE2303-309