Toward Extending Concentric Tube Robot Kinematics for Large Clearance and Impulse Curvature

Concentric Tube Robots (CTRs) have been proposed to operate within the unstructured environment for minimally invasive surgeries. In this letter, we consider the operation scenario where the tubes travel inside the channels with a large clearance or large curvature, such as aortas or industrial pipes. Accurate kinematic modeling of CTRs is required for the development of advanced control and sensing algorithms. To this end, we extended the conventional CTR kinematics model to a more general case with large tube-to-tube clearance and large centerline curvature. Numerical simulations and experimental validations are conducted to compare our model with respect to the conventional CTR kinematic model. In the physical experiments, our proposed model achieved a tip position error of 1.53 mm in the 2D planer case and 4.36 mm in 3D case, outperforming the state-of-the-art model by 71% and 66%, respectively.Comment: 8 pages, 6 figure

Evaluation of the Antidepressant Effect of the Functional Beverage Containing Active Peptides, Menthol and Eleutheroside, and Investigation of Its Mechanism of Action in Mice

Pozadina istraživanja. Depresija je postala globalna prijetnja ljudskom zdravlju. Znanstvenici provode različita ispitivanja uključujući i analizu prehrane kako bi riješili taj problem. Mnogi bioaktivni spojevi iz hrane imaju antidepresivni učinak. No, mali se broj istraživanja bavi razvojem industrijskih prehrambenih proizvoda s antidepresivnim učinkom. Svrha je ovoga rada bila ocijeniti antidepresivni učinak i mehanizme djelovanja funkcionalnog napitka pripremljenog od nekoliko sastojaka s mogućim antidepresivnim svojstvima. Eksperimentalni pristup. Napitak se sastoji od ulja paprene metvice, aktivnih peptida iz kazeina kravljeg mlijeka i ekstrakta sibirskog ginsenga (Acanthopanax senticosus), čiji je aktivni sastojak eleuterozid. Ispitan je dodatak različitih udjela ekstrakta sibirskog ginsenga da bi se utvrdila optimalna koncentracija eleuterozida u ovom funkcionalnom napitku, radi postizanja najboljeg antidepresivnog učinka. Provedena su opsežna ispitivanja ponašanja, uključujući preliminarne testove akutnog stresa te kroničnog nepredvidljivog blagog stresa. Rezultati i zaključci. Rezultati pokazuju da napitak s 15 mg/kg eleuterozida može bitno smanjiti vrijeme mirovanja miša u testovima vješanja za rep i prisilnog plivanja, pozitivno utjecati na preferenciju saharoze i promjene ponašanja u testu otvorenog polja, povećati udjel dopamina, norepinefrina, serotonina i aktivnost superoksid dismutaze, te smanjiti udjel malondialdehida u mozgu miševa. To potvrđuje da su poboljšana neurotransmisija monoamina i antioksidacijski status mogući mehanizmi antidepresivnog učinka. Novina i znanstveni doprinos. U ovom je radu predložen sastav funkcionalnog napitka s antidepresivnim svojstvima za učinkovitu prevenciju i liječenje depresije.Research background. Depression has become a global threat to human health. In order to solve it, researchers have conducted multi-faceted studies including diet. Many food-derived bioactive substances have shown antidepressant effects. However, there are few studies on the design of industrialized food with antidepressant effect. This study aims to evaluate the antidepressant effect of afunctional beverage made from several ingredients with potential antidepressant function and investigate its antidepressant mechanisms. Experimental approach. The beverage consists of peppermint oil, active peptides derived from bovine milk casein and Acanthopanax senticosus extract (ASE) whose active ingredient is eleutheroside. Different amounts of ASE were evaluated to determine the optimal concentration of eleutheroside in this functional beverage to deliver the best antidepressant effect through extensive behavioral testing, including preliminary acute stress experiments and further chronic unpredictable mild stress test. Results and conclusions. The results demonstrated that the beverage with 15 mg/kg of eleutheroside could significantly reduce the mice’s immobility time of tail suspension test and forced swimming test, recover mice’s sucrose preference and behavior changes in the open field test, improve the contents of dopamine, norepinephrine, 5-hydroxytryptamine and the activity of superoxide dismutase and reduce the content of malondialdehyde in mice’s brains, which indicated that the improvement of monoamine neurotransmitter systems and antioxidation was one potential mechanism of antidepressant action. Novelty and scientific contribution. This study provides a design of antidepressant functional beverage and an efficient way for the prevention and treatment of depression

miR-122 Targets X-Linked Inhibitor of Apoptosis Protein to Sensitize Oxaliplatin-Resistant Colorectal Cancer Cells to Oxaliplatin-Mediated Cytotoxicity

Background/Aims: Although oxaliplatin is one of the most effective chemotherapeutic drugs used to treat colorectal cancer (CRC), long-term administration usually induces acquired drug resistance during the course of treatment. Thus, there is an urgent need to explore novel strategies to improve the efficiency of cancer therapy. The aim of this study was to explore the effect of microRNA-122 (miR-122) on reversing oxaliplatin resistance in CRC. Methods: The expression of miR-122 in CRC cells was examined by quantitative reverse transcriptase real-time PCR. The cytotoxicity of oxaliplatin against CRC cells was evaluated by Cell Counting Kit-8 assays. Mitochondrial membrane potentials and cell apoptotic rates were measured by flow cytometry. Cellular protein expression and interactions were detected by western blot and co-immunoprecipitation. Results: Established oxaliplatin-resistant SW480 and HT29 cells (SW480/OR and HT29/OR) expressed significantly higher levels of X-linked inhibitor of apoptosis protein (XIAP) and lower levels of miR-122 compared with normal SW480 and HT29 cells, respectively. Our results showed that the downregulation of miR-122 was responsible for the overexpression of XIAP in these oxaliplatin-resistant CRC cells. We then found that the recovery of miR-122 expression can sensitize SW480/OR and HT29/OR cells to oxaliplatin-mediated apoptosis through the inhibition of XIAP expression. Conclusion: Upregulation of XIAP in CRC cells is responsible for the acquired resistance to oxaliplatin. Furthermore, miR-122 reversed oxaliplatin resistance in CRC by targeting XIAP

Cloning and expression characterization of elongation of very long-chain fatty acids protein 6 (elovl6) with dietary fatty acids, ambient salinity and starvation stress in Scylla paramamosain

Introduction: Elongation of very long-chain fatty acids protein 6 (ELOVL6) played crucial roles in regulating energy expenditure and fatty acid metabolism. Many studies have performed to investigate the physiological roles and regulatory mechanisms of elovl6 in fish and animals, while few studies were reported in crustaceans.Methods: Here we reported on the molecular cloning, tissue distribution and expression profiles in response to dietary fatty acids, ambient salinity and starvation stress in Scylla paramamosain by using rapid amplification of cDNA ends (RACE) and quantitative real-time PCR.Results: Three elovl6 isoforms (named elovl6a, elovl6b and elovl6c) were isolated from S. paramamosain in the present study. The complete sequence of elovl6a was 1345 bp, the full-length sequence of elovl6b was 1419 bp, and the obtained elovl6c sequence was 1375 bp in full length. The elovl6a, elovl6b and elovl6c encoded 287, 329 and 301 amino acids respectively, and exhibited the typical structural features of ELOVL protein family members. Phylogenetic analysis showed that the ELOVL6a from S. paramamosain clustered most closely to ELOVL6 from Portunus trituberculatus and Eriocheir sinensis, while the ELOVL6b and ELOVL6c from S. paramamosain gathered alone into a single branch. Quantitative real-time PCR exhibited that the relatively abundant expression of elovl6b was observed in intestine and stomach, and the elovl6a and elovl6c were highly expressed in hepatopancreas. In addition, studies found that replacing fish oil with soybean oil could significantly increase the transcriptional levels of three elovl6 in hepatopancreas of S. paramamosain, and the expression of elovl6a and elovl6c in hepatopancreas were more sensitive to dietary fatty acids than the elovl6b. Compared with the normal sea water group (27‰), the expression of sterol-regulatory element binding protein1c (srebp-1), elovl6a, elovl6b and elovl6c were upregulated in the low salinity groups, particularly in 7‰. On the contrary, the starvation stress suppressed the expression of srebp-1, elovl6a, elovl6b and elovl6c.Discussion: These results may contribute to understand the functions of elovl6 in fatty acid synthesis and regulatory mechanisms in crustaceans

Learning naive Bayes classifiers for music classification and retrieval

In this paper, we explore the use of naive Bayes classifiers for music classification and retrieval. The motivation is to employ all audio features extracted from local windows for classification instead of just using a single song-level feature vector produced by compressing the local features. Two variants of naive Bayes classifiers are studied based on the extensions of standard nearest neighbor and support vector machine classifiers. Experimental results have demonstrated superior performance achieved by the proposed naive Bayes classifiers for both music classification and retrieval as compared to the alternative methods

Music classification via the bag-of-features approach

A central problem in music information retrieval is audio-based music classification. Current music classification systems follow a frame-based analysis model. A whole song is split into frames, where a feature vector is extracted from each local frame. Each song can then be represented by a set of feature vectors. How to utilize the feature set for global song-level classification is an important problem in music classification. Previous studies have used summary features and probability models which are either overly restrictive in modeling power or numerically too difficult to solve. In this paper, we investigate the bag-of-features approach for music classification which can effectively aggregate the local features for song-level feature representation. Moreover, we have extended the standard bag-of-features approach by proposing a multiple codebook model to exploit the randomness in the generation of codebooks. Experimental results for genre classification and artist identification on benchmark data sets show that the proposed classification system is highly competitive against the standard methods

Optimal learning high-order Markov random fields priors of colour image

In this paper, we present an optimised learning algorithm for learning the parametric prior models for high-order Markov random fields (MRF) of colour images. Compared to the priors used by conventional low-order MRFs, the learned priors have richer expressive power and can capture the statistics of natural scenes. Our proposed optimal learning algorithm is achieved by simplifying the estimation of partition function without compromising the accuracy of the learned model. The parameters in MRF colour image priors are learned alternatively and iteratively in an EM-like fashion by maximising their likelihood. We demonstrate the capability of the proposed learning algorithm of highorder MRF colour image priors with the application of colour image denoising. Experimental results show the superior performance of our algorithm compared to the state-of-the-art of colour image priors in [1], although we use a much smaller training image set

A survey of audio-based music classification and annotation

Music information retrieval (MIR) is an emerging research area that receives growing attention from both the research community and music industry. It addresses the problem of querying and retrieving certain types of music from large music data set. Classification is a fundamental problem in MIR. Many tasks in MIR can be naturally cast in a classification setting, such as genre classification, mood classification, artist recognition, instrument recognition, etc. Music annotation, a new research area in MIR that has attracted much attention in recent years, is also a classification problem in the general sense. Due to the importance of music classification in MIR research, rapid development of new methods, and lack of review papers on recent progress of the field, we provide a comprehensive review on audio-based classification in this paper and systematically summarize the state-of-the-art techniques for music classification. Specifically, we have stressed the difference in the features and the types of classifiers used for different classification tasks. This survey emphasizes on recent development of the techniques and discusses several open issues for future research