40 research outputs found

    Differential Regulation of Primitive Myelopoiesis in the Zebrafish by Spi-1/Pu.1 and C/ebp1

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    The zebrafish has become a powerful tool for analysis of vertebrate hematopoiesis. Zebrafish, unlike mammals, have a robust primitive myeloid pathway that generates both granulocytes and macrophages. It is not clear how this unique primitive myeloid pathway relates to mammalian definitive hematopoiesis. In this study, we show that the two myeloid subsets can be distinguished using RNA in situ hybridization. Using a morpholino-antisense gene knockdown approach, we have characterized the hematopoietic defects resulting from knockdown of the myeloid transcription factor gene pu.1 and the unique zebrafish gene c/ebp1. Severe reduction of pu.1 resulted in complete loss of primitive macrophage development, with effects on granulocyte development only with maximal knockdown. Reduction of c/ebp1 did not ablate initial macrophage or granulocyte development, but resulted in loss of expression of the secondary granule gene lys C. These data reveal strong functional conservation of pu.1 between zebrafish primitive myelopoiesis and mammalian definitive myelopoiesis. Further, these results are consistent with a conserved role between c/ebp1 and mammalian C/EBPE, whose ortholog in zebrafish has not been identified. These studies validate the examination of zebrafish primitive myeloid development as a model for human myelopoiesis, and form a framework for identification and analysis of myeloid mutants.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63190/1/zeb.2007.0505.pd

    Polarization insensitive perfect absorber with nanorod arrays

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    We propose a polarization insensitive near infrared perfect absorber (PA) based on the localized surface plasmon resonances (LSPRs) of nanorod arrays. Polarization insensitivity of our PA structure is achieved by combining two sets of nanorods with x and y orientation respectively. Study carried out by finite difference time domain (FDTD) method shows absorption rate and the peak wavelength are sensitive to the lattice period both in x and y directions. The nanorods resonance is only slightly impacted by nanorods on its vertical direction. Further research into multiband polarization-insensitive absorber can be expected base on this work.EI

    Decay Estimates for a Type of Fuzzy Viscoelastic Integro-Differential Model

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    We consider a type of fuzzy viscoelastic integro-differential model in this paper. With the aid of some appropriate hypotheses, a unified method and the multiplier technique are implemented to get priori estimates precisely without constructing any auxiliary function. By establishing the estimation of energy function, we derive the stability result of the global solution, and we calculate the estimations of energy attenuation in exponential and polynomial forms, respectively

    WD repeat domain 5 promotes the development of late-onset preeclampsia by activating nuclear factor kappa B

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    ABSTRACT Purpose: Over-activation of nuclear factor kappa B (NF-ÎşB) was proven to be involved in the pathogenesis of preeclampsia. However, its regulation mechanism is not clear yet. This paper explored the role of WD repeat domain 5 (WDR5) in the development of late-onset preeclampsia and its relationship with NF-ÎşB. Methods: WDR5 expression was detected in normal placentas and placentas from late-onset preeclampsia patients. CCK-8 and colony formation assays were conducted to appraise the proliferative ability of trophoblast. Migration and invasion were observed by wound healing and transwell assays. The interaction between WDR5 and NF-ÎşB inhibitor I-kappa-B-alpha (IkBa) was verified by Co-immunoprecipitation analysis. Immunofluorescence was used to analyze the activation of NF-ÎşB. Finally, we tested the role of WDR5 using the mice late-onset preeclampsia model. Results: WDR5 was highly expressed in the placentas of late-onset preeclampsia patients. WDR5 overexpression suppressed cell proliferation, migration, and invasion in trophoblast. WDR5 could interact with IkBa to activate NF-ÎşB. Knockdown of NF-ÎşB counteracted the anti-proliferative and anti-metastatic effects of WDR5 overexpression in trophoblast. In-vivo studies suggested that targeting WDR5 combated late-onset preeclampsia development. Conclusions: Our finding provides new insights into the role of WDR5 in late-onset preeclampsia development

    Obscurin is required for the lateral alignment of striated myofibrils in zebrafish

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    Obscurin/obscurin-MLCK is a giant sarcomere-associated protein with multiple isoforms whose interactions with titin and small ankyrin-1 suggest that it has an important role in myofibril assembly, structural support, and the sarcomeric alignment of the sarcoplasmic reticulum. In this study, we characterized the zebrafish orthologue of obscurin and examined its role in striated myofibril assembly. Zebrafish obscurin was expressed in the somites and central nervous system by 24 hours post-fertilization (hpf) and in the heart by 48 hpf. Depletion of obscurin using two independent morpholino antisense oligonucleotides resulted in diminished numbers and marked disarray of skeletal myofibrils, impaired lateral alignment of adjacent myofibrils, disorganization of the sarcoplasmic reticulum, somite segmentation defects, and abnormalities of cardiac structure and function. This is the first demonstration that obscurin is required for vertebrate cardiac and skeletal muscle development. The diminished capacity to generate and organize new myofibrils in response to obscurin depletion suggests that it may have a vital role in the causation of or adaptation to cardiac and skeletal myopathies. Developmental Dynamics 235:2018–2029, 2006. © 2006 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/55797/1/20812_ftp.pd

    Structural Distortion of g-C<sub>3</sub>N<sub>4</sub> Induced by N-Defects for Enhanced Photocatalytic Hydrogen Evolution

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    Hydrogen evolution by photocatalytic technology has been one of the most promising and attractive solutions, and can harvest and convert the abundant solar energy into green, renewable hydrogen energy. As a new kind of photocatalytic material, graphitic carbon nitride (g-C3N4) has drawn much attention in photocataluytic H2 production due to its visible light response, ease of preparation and good stability. For a higher photocatalyic performance, N defects were introduced in to the traditional g-C3N4 in this work. The existence of N defects was proved by adequate material characterization. Significantly, a new absorption region at around 500 nm of N-deficient g-C3N4 appeared, revealing the exciting n-Ď€* transition of lone pair electrons. The photocatalytic H2 production performance of N-deficient g-C3N4 was increased by 5.8 times. The enhanced photocatalytic performance of N-deficient g-C3N4 was attributed to the enhanced visible light absorption, as well as the promoted separation of photo-generated carries and increased specific surface area

    Morphology, immunohistochemistry characteristics, and clinical presentation of microcystic urothelial carcinoma: a series of 10 cases

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    Abstract Background Microcystic urothelial carcinoma (MUC) is a rare variant of urothelial carcinoma with histological appearances similar to begin lesions. Thus far, approximately 50 cases have been reported. Here, we investigated the clinicopathological features of MUC. Methods Clinical data and paraffin-embedded tissue blocks were collected. Immunohistochemical staining and polymerase chain reaction–Sanger sequencing were performed to detect the phenotype and TERT mutation status of MUC, respectively. Results The mean patient age was 58.8 ± 14.5 years, with a male predominance (8:2). The pathological stage was T1 in one case, T2 in three cases, T3 in four cases, and T4 in two cases. Tumor metastases or death occurred in all five patients who were followed up within 1–3 years. Histological analyses revealed microcystic, tubular, cribriform, and occasionally cord-like structures, which generally lacked interstitial reactions. The lumens were empty, contained eosinophilic secretion, or were filled with mucin. The microcysts/tubules/cribriform patterns were lined by flat, cuboid, signet ring, or columnar types of epithelia. The cuboid, signet ring, and columnar types represented “glandular metaplasia” or glandular differentiation of urothelial carcinoma. Immunohistochemistry analyses revealed distinct co-expression patterns involving the luminal markers FOXA1 and GATA3, as well as the basal markers CK5/6 and CD44. All 10 cases exhibited a luminal phenotype according to the GATA3+/CK14- criterion, whereas nine cases exhibited a luminal phenotype according to the FOXA1+/CK14- criterion. The telomerase reverse transcriptase-C228T mutation was detected in seven cases. Conclusions MUC is a rare variant with a deceptively benign form of urothelial carcinoma, which is generally identified as a late-stage tumor with a poor prognosis. It exhibits distinct co-expression of luminal and basal markers, along with the TERT-C228T mutation

    Meiosis arrest female 1 (MARF1) has nuage-like function in mammalian oocytes.

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    Orderly regulation of meiosis and protection of germline genomic integrity from transposable elements are essential for male and female gamete development. In the male germline, these processes are ensured by proteins associated with cytoplasmic nuage, but morphologically similar germ granules or nuage have not been identified in mammalian female germ cells. Indeed, many mutations affecting nuage-associated proteins such as PIWI and tudor domain containing proteins 5 and 7 (TDRD5/7) can result in failure of meiosis, up-regulation of retrotransposons, and infertility only in males and not in females. We recently identified MARF1 (meiosis arrest female 1) as a protein essential for controlling meiosis and retrotransposon surveillance in oocytes; and in contrast to PIWI-pathway mutations, Marf1 mutant females are infertile, whereas mutant males are fertile. Here we put forward the hypothesis that MARF1 in mouse oocytes is a functional counterpart of the nuage-associated components of spermatocytes. We describe the developmental pattern of Marf1 expression and its roles in retrotransposon silencing and protection from DNA double-strand breaks. Analysis of MARF1 protein domains compared with PIWI and TDRD5/7 revealed that these functional similarities are reflected in remarkable structural analogies. Thus, functions that in the male germline require protein interactions and cooperative scaffolding are combined in MARF1, allowing a single molecule to execute crucial activities of meiotic regulation and protection of germline genomic integrity

    Winding-Locked Carbon Nanotubes/Polymer Nanofibers Helical Yarn for Ultrastretchable Conductor and Strain Sensor

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    Wearable and stretchable electronics including various conductors and sensors are featured with their lightweight, high flexibility, and easy integration into functional devices or textiles. However, most flexible electronic materials are still unsatisfactory due to their poor recoverability under large strain. Herein, we fabricated a carbon nanotubes (CNTs) and polyurethane (PU) nanofibers composite helical yarn with electrical conductivity, ultrastretchability, and high stretch sensitivity. The synergy of elastic PU molecules and springlike microgeometry enable the helical yarn excellent stretchability, while CNTs are stably winding-locked into the yarn through a simple twisting strategy, making good conductivity. By virtue of the interlaced conductive network of CNTs in microlevel and the helical structure in macrolevel, the CNTs/PU helical yarn achieves good recoverability within 900% and maximum tensile elongation up to 1700%. With these features, it can be used as a superelastic and highly stable conductive wire. Moreover, it also can monitor the human motion as a rapid-response strain sensor by adjusting the content of the CNTs simply. This general and low-cost strategy is of great promise for ultrastretchable wearable electronics and multifunctional devices
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