2,365 research outputs found

    Twin jets as a potential distance detector

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    A preview study of using observational data of proper motions and Doppler shifted velocities of twin-jets to determine the distance of sources inside and outside our galaxy is made. We investigate the feasibility of this method by studying the uncertainty of the distance caused by the uncertainties of the measured quantities. It shows that, when the motion of components of the jet is relativistic, then the uncertainty of the distance is within the same order of the uncertainties of the measured values of proper motions and Doppler shifted velocities. In particular, when assuming the pattern speed equals the flow speed in the jet, for 10% uncertainties of the measured quantities, the uncertainty of the distance caused by them would be well within 13%. With current technique, this method is realizable. For the convenience of choosing sources to observe, some sources as potential targets are also listed in this paper.Comment: 11 page

    Thermal conductivity of deformed carbon nanotubes

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    We investigate the thermal conductivity of four types of deformed carbon nanotubes by using the nonequilibrium molecular dynamics method. It is reported that various deformations have different influence on the thermal properties of carbon nanotubes. For the bending carbon nanotubes, the thermal conductivity is independent on the bending angle. However, the thermal conductivity increases lightly with XY-distortion and decreases rapidly with Z-distortion. The thermal conductivity does not change with the screw ratio before the breaking of carbon nanotubes but decreases sharply after the critical screw ratio.Comment: 6figure

    An amine-reactive tetraphenylethylene derivative for protein detection in SDS-PAGE

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    A new aggregation-induced emission (AIE) compound 1,2-bis[4-(isothiocyanatomethyl)phenyl]-1,2-diphenylethene (2) was synthesized for use in SDS-PAGE. The molecule is practically nonemissive in solution but becomes highly emissive after reacting with the amine groups of the proteins by either the prestaining or poststaining method. The sensitivity of 2 achieved in the prestaining method is the same as that of Coomassie brilliant blue (CBB), while that observed in the poststaining method is higher than that of CBB. Excellent linear responses with the amount of protein were obtained in both cases. The detection of a mixture of proteins with different molecular weights was successfully achieved

    Cyclooxygenase-2 expression and its association with vascular endothelial growth factor, microvessel density and clinicopathologic characteristics of colorectal carcinoma

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    The aim of this study was to investigate the expression of cyclooxygenase type-2 (COX-2) and its association with angiogenesis and clinicopathologic characteristics of colorectal carcinoma (CRC). COX-2 expression was detected by means of immunohistochemistry in a series of human tissue samples with CRC (n = 120), dysplasia tissue closely adjacent to carcinomas (n = 40) and normal colorectal mucosa (n = 40), and their expressions association with vascular endothelial growth factor (VEGF), CD31-labeled micorvessel density(MVD) in CRC and other clinicopathologic characteristics were investigated. The expression of COX-2 in CRC tissues (78.3%) was obviously higher than that in adjacent tissue and normal mucosal tissue (p<0.01). COX-2 expression was correlated significantly with the grading, advanced cancer, Dukes stage and lymph node metastasis, distant metastasis and VEGF (p<0.05). Our result demonstrates that COX-2 expression was significantly higher in earlier stages of CRC. It can be suggested that COX-2 expression may be important in the initial development of CRC. The findings of the present study suggest that COX-2 overexpression in CRC may be considered as a negative prognostic marker.

    Technical Advances in Single-Cell RNA Sequencing and Applications in Normal and Malignant Hematopoiesis

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    Single-cell RNA sequencing (scRNA-seq) has been tremendously developed in the past decade owing to overcoming challenges associated with isolation of massive quantities of single cells. Previously, cell heterogeneity and low quantities of available biological material posed significant difficulties to scRNA-seq. Cell-to-cell variation and heterogeneity are fundamental and intrinsic characteristics of normal and malignant hematopoietic cells; this heterogeneity has often been ignored in omics studies. The application of scRNA-seq has profoundly changed our comprehension of many biological phenomena, including organ development and carcinogenesis. Hematopoiesis, is actually a maturation process for more than ten distinct blood and immune cells, and is thought to be critically involved in hematological homeostasis and in sustaining the physiological functions. However, aberrant hematopoiesis directly leads to hematological malignancy, and a deeper understanding of malignant hematopoiesis will provide deeper insights into diagnosis and prognosis for patients with hematological malignancies. Here, we aim to review the recent technical progress and future prospects for scRNA-seq, as applied in physiological and malignant hematopoiesis, in efforts to further understand the hematopoietic hierarchy and to illuminate personalized therapy and precision medicine approaches used in the clinical treatment of hematological malignancies

    Comparative Metabonomic Investigations of Schistosoma japonicum From SCID Mice and BALB/c Mice: Clues to Developmental Abnormality of Schistosome in the Immunodeficient Host

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    The growth and development of schistosome has been affected in the immunodeficient hosts. But it remains unresolved about the molecular mechanisms involved in the development and reproduction regulation of schistosomes. This study tested and compared the metabolic profiles of the male and female Schistosoma japonicum worms collected from SCID mice and BALB/c mice at 5 weeks post infection using liquid chromatography tandem mass spectrometry (LC-MS/MS) platform, in which the worms from SCID mice were the investigated organisms and the worms from BALB/c mice were used as the controls. There were 1015 ion features in ESI+ mode and 342 ion features in ESI- mode were identified after filtration by false discovery rate. Distinct metabolic profiles were found to clearly differentiate both male and female worms in SCID mice from those in BALB/c mice using multivariate modeling methods including the Principal Component Analysis (PCA), Partial Least Squares Discriminant Analysis (PLS-DA), and Orthogonal Partial Least Squares Discriminant Analysis (OPLS-DA). There were more differential metabolites in female worms than in male worms between SCID mice and BALB/c mice. And common and uniquely perturbed metabolites and pathways were identified among male and female worms from SCID mice when compared with BALB/c mice. The enriched metabolite sets of the differential metabolites in male worms between SCID mice and BALB/c mice included bile acid biosynthesis, taurine and hypotaurine metabolism, sphingolipid metabolism, retinol metabolism, purine metabolism, etc. And the enriched metabolite sets of differential metabolites in female worms included retinol metabolism, alpha linolenic acid and linoleic acid metabolism, purine metabolism, sphingolipid metabolism, glutamate metabolism, etc. Further detection and comparison in transcript abundance of genes of the perturbed retinol metabolism and its associated meiosis process in worms identified clues suggesting accumulated retinyl ester and perturbed meiotic process. These findings suggested an association between the schistosome with retarded growth and development in SCID mice and their perturbed metabolites and metabolic pathways, and provided a new insight into the growth and development regulation of S. japonicum worms from the metabolic level, which indicated great clues for discovery of drugs or vaccines against the parasites and disease with more researches
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