215 research outputs found

    Rigidity of non-renormalizable Newton maps

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    Non-renormalizable Newton maps are rigid. More precisely, we prove that their Julia set carries no invariant line fields and that the topological conjugacy is equivalent to quasi-conformal conjugacy in this case

    Ordered Self-Assembling of Tetrahedral Oxide Nanocrystals

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    ©1997 The American Physical Society. The electronic version of this article is the complete one and can be found online at: http://link.aps.org/doi/10.1103/PhysRevLett.79.2570DOI: 10.1103/PhysRevLett.79.2570Self-assembling of size, shape, and phase controlled nanocrystals into superlattices with translational and even orientational ordering is a new approach for engineering nanocrystal materials and devices. High purity tetrahedral nanocrystals of CoO, with edge lengths of 4.4±0.2 nm, were synthesized and separated from Co nanocrystals, using a novel magnetic field phase-selection technique. Self-assembling of the faceted CoO nanocrystals forms ordered superlattices, the structures of which are determined

    Downregulation of desmuslin in primary vein incompetence

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    ObjectivePrimary vein incompetence is one of the most common diseases of the peripheral veins, but its pathogenesis is unknown. These veins present obvious congenital defects, and examination of gene expression profiles of the incompetent vein specimens may provide important clues. The aim of this study was to screen for genes affecting the primary vein incompetence phenotype and test the differential expression of certain genes.MethodsWe compared gene expression profiles of valvular areas from incompetent and normal great saphenous veins at the saphenofemoral junctions by fluorescent differential display reverse-transcription polymerase chain reaction (FDD RT-PCR). Differentially expressed complimentary DNAs (cDNAs) were confirmed by Northern blotting and semi-quantitative RT-PCR. Similarity of the cDNAs sequences to GenBank sequences was determined. Gene expression status was then determined by Western blot analysis and immunohistochemical techniques.ResultsThere were >30 differentially expressed cDNA bands. Sequence analysis revealed that a cDNA fragment obviously downregulated in incompetent great saphenous vein was a portion of the messenger RNA (mRNA) encoding desmuslin, a newly discovered intermittent filament protein. Northern blotting and semi-quantitative RT-PCR analysis revealed a similar mRNA expression profile of the desmuslin gene in other samples. Western blotting and immunohistochemical techniques localized the desmuslin protein mainly in the cytoplasm of venous smooth muscle cells. The amount of desmuslin was greatly decreased in the smooth muscle cells of incompetent veins.ConclusionsThe expression of many genes is altered in primary vein incompetence. Up- or downregulation of these genes may be involved in the pathogenesis of this disease. Desmuslin expression is downregulated in the abnormal veins. Its effect on the integrity of smooth muscle cells might be related to malformation of the vein wall. Further studies are needed to investigate other differentially expressed cDNAs and the exact role of desmuslin in this disease.Clinical RelevancePrimary vein incompetence is a frequent and refractory disease of the peripheral veins. Exploring its pathogenesis may enhance our comprehension and management of this disease. We used reliable techniques to detect disease-related genes and confirmed downregulation of desmuslin in abnormal veins. Alteration of these genes might be used as disease markers or gene therapy targets

    First Efficacy Results of Capecitabine with Anthracycline- and Taxane-Based Adjuvant Therapy in High-Risk Early Breast Cancer: A Meta-Analysis

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    Background: Capecitabine is effective and indicated for the salvage treatment of metastatic breast cancer. Therefore, it is essential to evaluate the efficacy of capecitabine in the adjuvant setting. There have been two large randomized studies to determine whether patients with high-risk early breast cancer benefit from the addition of capecitabine to standard chemotherapy, but they have yielded inconsistent results. We first undertook a meta-analysis to evaluate the efficacy of the addition of capecitabine over standard treatment

    Site-specific relapse pattern of the triple negative tumors in Chinese breast cancer patients

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    BACKGROUND: It has been reported that triple negative phenotype is characterized by aggressive clinical history in Western breast cancer patients, however its pattern of metastatic spread had never been reported in the Chinese population. Considering racial disparities, we sought to analyze the spread pattern for different sites of first recurrence in Chinese triple negative breast cancers. METHODS: A retrospective study of 1662 patients was carried out from a large database of breast cancer patients undergoing surgery between January 1, 2000 and March 31, 2004 at the Cancer Hospital, Fudan University, Shanghai, China. Survival curves were generated using the Kaplan-Meier method and annual relapse hazards were estimated by the hazard function. RESULTS: We found a statistically significant difference in relapse-free survival (RFS) for locoregional and visceral recurrence (P = 0.007 and P = 0.025, respectively) among the triple negative, ERBB2+ and HR+/ERBB2- subgroups in univariate analysis. In the multivariate Cox proportional hazards regression analysis, RFS for either locoregional or visceral relapse in the triple negative category was inferior to that in HR+/ERBB2- patients (P = 0.027 and P = 0.005, respectively), but comparable to that in ERBB2+ women (both P >0.05). Furthermore, the early relapse peak appeared later in the triple negative group than that in the ERBB2+ counterpart for both locoregional and visceral relapse. On the other hand, when compared with triple negative breast cancers, a significantly lower risk of developing bone relapse was discerned for ERBB2+ women (P = 0.048; HR = 0.384, 95% CI 0.148-0.991), with the borderline significance for HR+/ERBB2- breast cancers (P = 0.058; HR = 0.479, 95% CI 0.224-1.025). In terms of bone metastasis, the hazard rate remained higher for the triple negative category than that for the ERBB2+ subtype. CONCLUSION: Based on the site-specific spread pattern in different subgroups, the triple negative category of breast cancers in the Chinese population exhibits a different pattern of relapse, which indicates that different organotropism may be due to the different intrinsic subtypes. A better knowledge of the triple negative category is warranted for efficacious systemic regimens to decrease and/or delay the relapse hazard

    Current development and future challenges in microplastic detection techniques: a bibliometrics-based analysis and review.

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    Microplastics have been considered a new type of pollutant in the marine environment and have attracted widespread attention worldwide in recent years. Plastic particles with particle size less than 5 mm are usually defined as microplastics. Because of their similar size to plankton, marine organisms easily ingest microplastics and can threaten higher organisms and even human health through the food chain. Most of the current studies have focused on the investigation of the abundance of microplastics in the environment. However, due to the limitations of analytical methods and instruments, the number of microplastics in the environment can easily lead to overestimation or underestimation. Microplastics in each environment have different detection techniques. To investigate the current status, hot spots, and research trends of microplastics detection techniques, this review analyzed the papers related to microplastics detection using bibliometric software CiteSpace and COOC. A total of 696 articles were analyzed, spanning 2012 to 2021. The contributions and cooperation of different countries and institutions in this field have been analyzed in detail. This topic has formed two main important networks of cooperation. International cooperation has been a common pattern in this topic. The various analytical methods of this topic were discussed through keyword and clustering analysis. Among them, fluorescent, FTIR and micro-Raman spectroscopy are commonly used optical techniques for the detection of microplastics. The identification of microplastics can also be achieved by the combination of other techniques such as mass spectrometry/thermal cracking gas chromatography. However, these techniques still have limitations and cannot be applied to all environmental samples. We provide a detailed analysis of the detection of microplastics in different environmental samples and list the challenges that need to be addressed in the future

    The relationship between Cho/NAA and glioma metabolism: implementation for margin delineation of cerebral gliomas

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    BACKGROUND: The marginal delineation of gliomas cannot be defined by conventional imaging due to their infiltrative growth pattern. Here we investigate the relationship between changes in glioma metabolism by proton magnetic resonance spectroscopic imaging ((1)H-MRSI) and histopathological findings in order to determine an optimal threshold value of choline/N-acetyl-aspartate (Cho/NAA) that can be used to define the extent of glioma spread. METHOD: Eighteen patients with different grades of glioma were examined using (1)H-MRSI. Needle biopsies were performed under the guidance of neuronavigation prior to craniotomy. Intraoperative magnetic resonance imaging (MRI) was performed to evaluate the accuracy of sampling. Haematoxylin and eosin, and immunohistochemical staining with IDH1, MIB-1, p53, CD34 and glial fibrillary acidic protein (GFAP) antibodies were performed on all samples. Logistic regression analysis was used to determine the relationship between Cho/NAA and MIB-1, p53, CD34, and the degree of tumour infiltration. The clinical threshold ratio distinguishing tumour tissue in high-grade (grades III and IV) glioma (HGG) and low-grade (grade II) glioma (LGG) was calculated. RESULTS: In HGG, higher Cho/NAA ratios were associated with a greater probability of higher MIB-1 counts, stronger CD34 expression, and tumour infiltration. Ratio threshold values of 0.5, 1.0, 1.5 and 2.0 appeared to predict the specimens containing the tumour with respective probabilities of 0.38, 0.60, 0.79, 0.90 in HGG and 0.16, 0.39, 0.67, 0.87 in LGG. CONCLUSIONS: HGG and LGG exhibit different spectroscopic patterns. Using (1)H-MRSI to guide the extent of resection has the potential to improve the clinical outcome of glioma surgery