Direct Observation of Electrostatically Driven Band Gap Renormalization in a Degenerate Perovskite Transparent Conducting Oxide

We have directly measured the band gap renormalization associated with the Moss-Burstein shift in the perovskite transparent conducting oxide (TCO), La-doped BaSnO_{3}, using hard x-ray photoelectron spectroscopy. We determine that the band gap renormalization is almost entirely associated with the evolution of the conduction band. Our experimental results are supported by hybrid density functional theory supercell calculations. We determine that unlike conventional TCOs where interactions with the dopant orbitals are important, the band gap renormalization in La-BaSnO_{3} is driven purely by electrostatic interactions.

Establishment, Differentiation, Electroporation and Nuclear Transfer of Porcine Mesenchymal Stem Cells

The limited success of somatic cell nuclear transfer (SCNT) is largely attributed to defects in epigenetic reprogramming of the donor genome. Donor cell types with distinct potential competence may offer different epigenetic flexibility for subsequent genome reprogramming in SCNT. Stem cells possibly enable their genomes to be more readily reprogrammed than differentiated cells. To improve the efficiency of cloning, porcine mesenchymal stem cells (pMSCs) were isolated and well identified by 6-channel flow cytometry and differentiation assays and were used as donors in SCNT. Compared with porcine embryonic fibroblasts (pEFs), our results showed that pMSCs markedly enhanced cloned embryo development in terms of cleavage and blastocyst formation (p < 0.05). To enhance the epigenetic flexibility of pMSCs, classical reprogramming factors (RFs) were transfected by electroporation, and we achieved optimization with ectopic expression of RFs in pMSCs. Our results suggest that the epigenetic status of donor cells has an improvement on genome reprogramming, and multipotent pMSCs favoured subsequent embryonic development.

miR-23b-3p regulates the chemoresistance of gastric cancer cells by targeting ATG12 and HMGB2

Chemotherapy is an important treatment modality for gastric cancer (GC); however, it usually fails because of drug resistance, especially multidrug resistance (MDR). Previously, we found a novel subset of MDR-associated microRNAs (miRNAs) through high-throughput functional screening. In this report, we investigated the exact roles and mechanisms of miR-23b-3p in the MDR of GC. Using gain or loss-of-function in in vitro and in vivo experiments, we found that overexpression of miR-23b-3p reversed cancer cell resistance to multiple chemotherapeutics in vitro and sensitize tumors to chemotherapy in vivo. Reporter gene assay and western blot analysis showed that ATG12 and HMGB2 were the direct targets of miR-23b-3p. Meanwhile, ATG12 and HMGB2 were positively associated with the occurrence of autophagy. Reducing the expression of these target genes by siRNA or inhibition of autophagy both sensitized GC cells to chemotherapy. These findings suggest that a miR-23b-3p/ATG12/HMGB2/autophagy-regulatory loop has a critical role in MDR in GC. In addition, miR-23b-3p could be used as a prognostic factor for overall survival in GC. In conclusion, our data demonstrated that miR-23b-3p inhibited autophagy mediated by ATG12 and HMGB2 and sensitized GC cells to chemotherapy, and suggested the potential application of miR-23b-3p in drug resistance prediction and treatment.

Unification of catalytic oxygen reduction and hydrogen evolution reactions: highly dispersive Co nanoparticles encapsulated inside Co and nitrogen co-doped carbon

The elaborately synthesized Co nanoparticles encapsulated inside Co and nitrogen co-doped carbon catalysts with homogenous distribution of Co NPs exhibit evidently outstanding performances toward ORR/HER.

Real-time aortic valve segmentation from transesophageal echocardiography sequence

PURPOSE

Geometric features of the aortic valve play an important role in many applications, such as the clinical diagnostics, shape modeling and image-guided cardiac interventions, especially for the transcatheter aortic valve implantation (TAVI) procedure. However, few works have been reported on the topic of aortic valve segmentation from transesophageal echocardiography (TEE) sequences. To obtain accurate segmentation results and further provide valid support for TAVI, this paper presents a real-time method for segmenting the aortic valve from intraoperative, short-axis view TEE sequences, using an improved probability estimation and continuous max-flow (CMF) approach.

METHODS

The proposed segmentation method includes two key stages: (1) In the probability estimation stage, five different prior frames spanning a cardiac circle are firstly selected with the aortic valve manually segmented by an expert. Then, the improved composite probability estimation (CPE) and single probability estimation (SPE) over the five prior frames are, respectively, constructed based on their radial average intensity and radial distance. (2) In the energy function construction stage, the similarity metric is calculated to find out the matching exponents between the current input TEE frame and the prior frames. The typical foreground and background intensities of prior images are therefore used to construct the corresponding energy function. Finally, the CMF approach, accelerated with a graphic processing unit (GPU), is employed to achieve the aortic valve contours in real time.

RESULTS

The evaluation study contained 30 sequences, with each containing 62-146 short-axis TEE frames. The results were compared with the manual segmentation (ground truth). The average symmetric contour distance (ASCD), dice metric (DM) and the reliability of the algorithm reached 0.85 ± 0.21 mm, 0.96 ± 0.01 and 0.90 (d = 0.95), respectively, and the computation time was 57.04 ± 8.98 ms per frame.

CONCLUSION

The experiment results reveal that the proposed method can achieve accurate and real-time segmentation of aortic valve from TEE sequence of short-axis view.

Clinical features of macrophage activation syndrome in the adult northern Chinese population

OBJECTIVE

Macrophage activation syndrome (MAS) is a relatively rare but potentially fatal complication of childhood rheumatic illnesses. We sought to provide insight for the timely recognition and diagnosis of MAS and efficacious disease management in adults with rheumatic diseases.

METHODS

Clinical files for eight adult MAS patients treated at the Second Affiliated Hospital of Harbin Medical University were analyzed for clinical manifestations, laboratory investigations, therapeutic measurements and clinical outcomes.

RESULTS

The study included male and female patients with ages ranging from 16 to 59 years old. All patients were diagnosed with underlying rheumatic diseases with five patients having adult-onset Still's disease (AOSD), two patients having systemic lupus erythematosus (SLE) and one patient having Sjögren's syndrome (SS). The interval from fever onset to MAS diagnosis varied from seven days to 40 days. The most common clinical presentations were prolonged high fever, respiratory symptoms and jaundice. No patients had symptoms involving the central nervous system (CNS). Laboratory findings showed peripheral cytopenias, elevated liver enzymes, elevated triglycerides, hypofibrinogenemia and bone marrow hemophagocytosis. Potential effective treatments for MAS include glucocorticoid plus immunoglobulin therapy, but delays in diagnosis and treatment may lead to a fatal disease course.

CONCLUSION

MAS in adults may not be as rare as was once thought, although the clinical features of MAS in adults often differ from those seen in children. The MAS mortality in adults is far higher than that for children. A diagnosis of MAS should be considered when a patient with rheumatic disease presents with prolonged high fever, peripheral cytopenia and liver failure. Collection of bone marrow aspirates is critical for accurate diagnosis and MAS therapy should begin as early as possible.

A novel aortic valve segmentation from ultrasound image using continuous max-flow approach

Geometric features of aortic valve can be applied in diagnostic, modeling and image-guided cardiac intervention, however methods to accurately and effectively delineate aortic valve from ultrasound (US) image are not well addressed. This paper proposes a novel aortic valve segmentation algorithm for intra-operative 2D short-axis US image using probability estimation and continuous max-flow (CMF) approach. The algorithm first calculates composite probability estimation (CPE) and single probability estimation (SPE) over 5 prior images based on both intensity and distance to the corresponding centroid, then the energy function for the current input image is constructed, followed by a Graphic Processing Unit (GPU) accelerated CMF approach to achieve aortic valve contours in approximately real time. Quantitative evaluations over 270 images acquired from 3 subjects indicated the results of the algorithm had good correlation with the manual segmentation results (ground truth) by an expert. The Average Symmetric Contour Distance (ASCD), Dice Metric (DM), and Reliability were employed to evaluate our algorithm, and the evaluation results of these three metrics were 1.79±0.46 (in pixels), 0.96±0.01 and 0.84 (d=0.95) respectively, where the computational time was 39.23±5.02 ms per frame.

An augmented magnetic navigation system for Transcatheter Aortic Valve Implantation

This research proposes an augmented magnetic navigation system for Transcatheter Aortic Valve Implantation (TAVI) employing a magnetic tracking system (MTS) combined with a dynamic aortic model and intra-operative ultrasound (US) images. The dynamic 3D aortic model is constructed based on the preoperative 4D computed tomography (CT), which is animated according to the real time electrocardiograph (ECG) input of patient. And a preoperative planning is performed to determine the target position of the aortic valve prosthesis. The temporal alignment is performed to synchronize the ECG signals, intra-operative US image and tracking information. Afterwards, with the assistance of synchronized ECG signals, the contour of aortic root automatic extracted from short axis US image is registered to the dynamic aortic model by a feature based registration intra-operatively. Then the augmented MTS guides the interventionist to confidently position and deploy the aortic valve prosthesis to target. The system was validated by animal studies on three porcine subjects, the deployment and tilting errors of which are 3.17 ± 0.91 mm and 7.40 ± 2.89° respectively.

MicroRNA-7 functions as an anti-metastatic microRNA in gastric cancer by targeting insulin-like growth factor-1 receptor

Metastasis is a major clinical obstacle in the treatment of gastric cancer (GC) and it accounts for the majority of cancer-related mortality. MicroRNAs have recently emerged as regulators of metastasis by acting on multiple signaling pathways. In this study, we found that miR-7 is significantly downregulated in highly metastatic GC cell lines and metastatic tissues. Both gain-of-function and loss-of-function experiments showed that increased miR-7 expression significantly reduced GC cell migration and invasion, whereas decreased miR-7 expression dramatically enhanced cell migration and invasion. In vivo metastasis assays also demonstrated that overexpression of miR-7 markedly inhibited GC metastasis. Moreover, the insulin-like growth factor-1 receptor (IGF1R) oncogene, which is often mutated or amplified in human cancers and functions as an important regulator of cell growth and tumor invasion, was identified as a direct target of miR-7. Silencing of IGF1R using small interefering RNA (siRNA) recapitulated the anti-metastatic function of miR-7, whereas restoring the IGF1R expression attenuated the function of miR-7 in GC cells. Furthermore, we found that suppression of Snail by miR-7, through targeting IGF1R, increased E-cadherin expression and partially reversed the epithelial-mesenchymal transition (EMT). Finally, analyses of miR-7 and IGF1R levels in human primary GC with matched lymph node metastasis tissue arrays revealed that miR-7 is inversely correlated with IGF1R expression. The present study provides insight into the specific biological behavior of miR-7 in EMT and tumor metastasis. Targeting this novel miR-7/IGF1R/Snail axis would be helpful as a therapeutic approach to block GC metastasis.

[Protective effect of salvianolic acid B on isolated heart ischemia/reperfusion injury in rats]

OBJECTIVE

To study the protective effect and mechanism of salvianolic acid B on isolated heart ischemia/reperfusion injury in rats.

METHOD

Forty-eight SD rats were divided into 6 groups randomly(n = 8): the control group, the positive administration group (verapamil 150 microg x L(-1)), and high, middle and low-dose salvianolic acid B groups (10, 5, 2.5 mg x L(-1)). The myocardial ischemia/reperfusion injury model was established using the Langendorff method, re-perusing isolated working hearts for 30 min after ischemia for 25 min. A water-bag catheter was inserted in rat left atrium for recording the effect of salvianolic acid B on hemodynamics indexes-AST, LDH, SOD and MDA.

RESULT

Various group with different doses showed that salvianolic acid B decreased AST, release of LDH and formation of MDA and increased SOD activity.

CONCLUSION

Salvianolic acid B showed a protective effect on myocardial ischemia/reperfusion injury. Its mechanism may be related with improvement of cardiac contractility, cleaning of oxygen free radicals and reduction of lipid peroxidation.

Primed in situ labeling for detecting single-copy genes

In order to analyze male sterility caused by deletion of SRY and DAZ, we examined the accuracy and cost-effectiveness of a modified primed in situ labeling (PRINS) technique for detection of single-copy genes. Peripheral blood samples were collected from 50 healthy men; medium-term cultured lymphocytes from these samples were suspended in fixative solution and then spread on clean slides. We used four primers homologous to unique regions of the SRY and DAZ regions of the human Y-chromosome and incorporated reagents to increase polymerase specificity and to enhance the hybridization signal. PRINS of SRY and DAZ gave bands at Yp11.3 and Yq11.2, respectively, in all 50 metaphase spreads. The PRINS SRY signals were as distinct as those obtained using traditional fluorescence in situ hybridization (FISH). This new method is ideal for rapid localization of single-copy genes or small DNA segments, making PRINS a cost-effective alternative to FISH. Further enhancement of PRINS to increase its speed of implementation may lead to its wide use in the field of medical genetics.