248 research outputs found

    General mapping of one-dimensional non-Hermitian mosaic models to non-mosaic counterparts: Mobility edges and Lyapunov exponents

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    We establish a general mapping from one-dimensional non-Hermitian mosaic models to their non-mosaic counterparts. This mapping can give rise to mobility edges and even Lyapunov exponents in the mosaic models if critical points of localization or Lyapunov exponents of localized states in the corresponding non-mosaic models have already been analytically solved. To demonstrate the validity of this mapping, we apply it to two non-Hermitian localization models: an Aubry-Andr\'e-like model with nonreciprocal hopping and complex quasiperiodic potentials, and the Ganeshan-Pixley-Das Sarma model with nonreciprocal hopping. We successfully obtain the mobility edges and Lyapunov exponents in their mosaic models. This general mapping may catalyze further studies on mobility edges, Lyapunov exponents, and other significant quantities pertaining to localization in non-Hermitian mosaic models.Comment: 9 pages, 2 figure

    Transcriptome of Small Regulatory RNAs in the Development of the Zoonotic Parasite Trichinella spiralis

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    BACKGROUND: Trichinella spiralis is a parasite with unique features. It is a multicellular organism but with an intracellular parasitization and development stage. T. spiralis is the helminthic pathogen that causes zoonotic trichinellosis and afflicts more than 10 million people worldwide, whereas the parasite's biology, especially the developmental regulation is largely unknown. In other organisms, small non-coding RNAs, such as microRNAs (miRNA) and small interfering RNAs (siRNA) execute post-transcriptional regulation by translational repression or mRNA degradation, and a large number of miRNAs have been identified in diverse species. In T. spiralis, the profile of small non-coding RNAs and their function remains poorly understood. METHODOLOGY AND PRINCIPAL FINDINGS: Here, the transcriptional profiles of miRNA and siRNA in three developmental stages of T. spiralis in the rat host were investigated, and compared by high-throughput cDNA sequencing technique ("RNA-seq"). 5,443,641 unique sequence tags were obtained. Of these, 21 represented conserved miRNAs related to 13 previously identified metazoan miRNA families and 213 were novel miRNAs so far unique to T. spiralis. Some of these miRNAs exhibited stage-specific expression. Expression of miRNAs was confirmed in three stages of the life cycle by qRT-PCR and northern blot analysis. In addition, endogenous siRNAs (endo-siRNAs) were found mainly derived from natural antisense transcripts (NAT) and transposable elements (TE) in the parasite. CONCLUSIONS AND SIGNIFICANCE: We provide evidence for the presence of miRNAs and endo-siRNAs in T. spiralis. The miRNAs accounted for the major proportion of the small regulatory RNA population of T. spiralis, while fewer endogenous siRNAs were found. The finding of stage-specific expression patterns of the miRNAs in different developmental stages of T. spiralis suggests that miRNAs may play important roles in parasite development. Our data provide a basis for further understanding of the molecular regulation and functional evolution of miRNAs in parasitic nematodes

    Engineering PtRu bimetallic nanoparticles with adjustable alloying degree for methanol electrooxidation: enhanced catalytic performance

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    Abstract(#br)PtRu bimetal is of particularly attractive in various electrocatalytic reactions owing to its synergistic effect, ligand effect and strain effect. Here, PtRu nanoalloy supported on porous graphitic carbon (PC) has been successfully prepared via a very facile method involving co-reduction the precursors of Pt and Ru at 300 °C by H 2 (PtRu/PCL) followed by thermal treatment at high temperature (700 °C, PtRu/PC–H). Specifically, the electrocatalytic performance of PtRu/PC nanoalloy could be dramatically enhanced through high-temperature annealing. This strategy has synthesized smaller Pt and PtRu nanoparticles (ca. L and Pt/PC nanocatalysts. The mass activity and specific activity on PtRu/PC–H nanoalloy can be increased to 1674.2 mA mg −1 Pt and 4.4 mA cm −2 for MOR, it is 4.08 and 8.80 times higher than that of the Pt/PC nanocatalyst, respectively. From in-situ FTIR spectra, we can discover PtRu/PC–H nanoalloy generates CO 2 at a lower potential of −150 mV than those on PtRu/PC–L (0 mV) and Pt/PC (50 mV) nanocatalysts, dramatically improves the ability of cleavage C–H bond and alleviates the CO ads poisoning on active sites. The PtRu/PCH nanocatalyst exhibits maximum power density of 83.7 mW cm −2 in single methanol fuel cell test, which more than threefold than that of commercial Pt/C as the anode catalyst. Those experimental results open an effective and clean avenue in the development and preparation of high-performance Pt-based nanocatalysts for direct methanol fuel cells

    Special IR properties of palladium nanoparticles and their aggregations in CO molecular probe infrared spectroscopy

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    Dispersed Pd nanoparticles (Pd-n) have been synthesized by reducing H2PdCl4 with ethanol, and stabilized using poly(vinylpyrrolidone) (PVP). The Pd-n is applied to the glassy carbon substrate to form a thin film, and then the potential cyclic scanning at 50 mV. s(-1) from -0.25 to 1.25 V was carried out for about 30 min to form the aggregations of Pd-n (Pd-n(ag)). FTIR spectroscopy of both transmission and reflection modes was employed to study CO adsorption on Pd-n and Pd-n(ag) in both solid\liquid and solid\gas; interfaces. It has been revealed that CO adsorption on Pd-n film yields two IR bands near 1964 and 1906 cm(-1), which are assigned to IR absorption of CO bonded on asymmetric and symmetric bridge sites, respectively. In contrast to the IR properties of CO adsorbed on Pd-n, only species of CO bonded on asymmetric bridge sites was determined on Pd-n(ag), and the direction of the IR band near 1963 cm(-1) is completely inverted. The full width at half-maximum (FWHM) of the COBas band near 1964 cm(-1) is measured to be 14 cm(-1) on Pd-n film, while it is 24 cm(-1) on Pd-n(ag) film. The results of the present study demonstrated that the inverting of the IR band direction is a general phenomenon that is closely related to the interaction between nanoparticles in aggregation of Pd-n

    Ultra-broadband Light Absorption by a Sawtooth Anisotropic Metamaterial Slab

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    We present an ultra broadband thin-film infrared absorber made of saw-toothed anisotropic metamaterial. Absorbtivity of higher than 95% at normal incidence is supported in a wide range of frequencies, where the full absorption width at half maximum is about 86%. Such property is retained well at a very wide range of incident angles too. Light of shorter wavelengths are harvested at upper parts of the sawteeth of smaller widths, while light of longer wavelengths are trapped at lower parts of larger tooth widths. This phenomenon is explained by the slowlight modes in anisotropic metamaterial waveguide. Our study can be applied in the field of designing photovoltaic devices and thermal emitters.Comment: 12 pages, 4 picture

    The Gaps Between Current Management of Intracerebral Hemorrhage and Evidence-Based Practice Guidelines in Beijing, China

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    Background: The leading cause of death in China is stroke, a condition that also contributes heavily to the disease burden. Nontraumatic intracerebral hemorrhage (ICH) is the second most common cause of stroke. Compared to Western countries, in China the proportion of ICH is significantly higher. Standardized treatment based on evidence-based medicine can help reduce ICH's burden. In the present study we aimed to explore the agreement between the management strategies during ICH's acute phase and Class I recommendations in current international practice guidelines in Beijing (China), and to elucidate the reasons underlying any inconsistencies found.Method: We retrospectively collected in-hospital data from 1,355 ICH patients from 15 hospitals in Beijing between January and December 2012. Furthermore, a total of 75 standardized questionnaires focusing on ICH's clinical management were distributed to 15 cooperative hospitals. Each hospital randomly selected five doctors responsible for treating ICH patients to complete the questionnaires.Results: Numerous approaches were in line with Class I recommendations, as follows: upon admission, all patients underwent radiographic examination, about 93% of the survivors received health education and 84.5% of those diagnosed with hypertension were prescribed antihypertensive treatment at discharge, in-hospital antiepileptic drugs were administered to 91.8% of the patients presenting with seizures, and continuous monitoring was performed for 88% of the patients with hyperglycemia on admission. However, several aspects were inconsistent with the guidelines, as follows: only 14.2% of the patients were initially managed in the neurological intensive care unit and 22.3% of the bedridden patients received preventive treatment for deep vein thrombosis (DVT) within 48 h after onset. The questionnaire results showed that imaging examination, blood glucose monitoring, and secondary prevention of ICH were useful to more clinicians. However, the opposite occurred for the neurological intensive care unit requirement. Regarding the guidelines' recognition, no significant differences among the 3 education subgroups were observed (p > 0.05).Conclusions: Doctors have recognized most of ICH's evidence-based practice guidelines. However, there are still large gaps between the management of ICH and the evidence-based practice guidelines in Beijing (China). Retraining doctors is required, including focusing on preventing DVT providing a value from the National Institutes of Health Stroke Scale and Glasgow Coma Scalescores at the time of admission

    Store Operated Calcium Entry Suppressed TGF-β1/SMAD3 Signaling Pathway in Glomerular Mesangial Cells

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    Our previous study demonstrated that the abundance of extracellular matrix proteins was suppressed by store-operated Ca^(2+) entry (SOCE) in mesangial cells (MCs). The present study was conducted to investigate the underlying mechanism focused on the transforming growth factor-β1 (TGF-β1)/Smad3 pathway, a critical pathway for ECM expansion in diabetic kidneys. We hypothesized that SOCE suppressed ECM protein expression by inhibiting this pathway in MCs. In cultured human MCs, we observed that TGF-β1 (5 ng/ml for 15 h) significantly increased Smad3 phosphorylation, as evaluated by immunoblot. However, this response was markedly inhibited by thapsigargin (1 µM), a classical activator of store-operated Ca^(2+) channels. Consistently, both immunocytochemistry and immunoblot showed that TGF-β1 significantly increased nuclear translocation of Smad3, which was prevented by pretreatment with thapsigargin. Importantly, the thapsigargin effect was reversed by lanthanum (La^(3+); 5 µM) and GSK-7975A (10 µM), both of which are selective blockers of store-operated Ca^(2+) channels. Furthermore, knockdown of Orai1, the pore-forming subunit of the store-operated Ca^(2+) channels, significantly augmented TGF-β1-induced Smad3 phosphorylation. Overexpression of Orai1 augmented the inhibitory effect of thapsigargin on TGF-β1-induced phosphorylation of Smad3. In agreement with the data from cultured MCs, in vivo knockdown of Orai1 specific to MCs using a targeted nanoparticle small interfering RNA delivery system resulted in a marked increase in abundance of phosphorylated Smad3 and in nuclear translocation of Smad3 in the glomerulus of mice. Taken together, our results indicate that SOCE in MCs negatively regulates the TGF-β1/Smad3 signaling pathway

    The auxin response factor, OsARF19, controls rice leaf angles through positively regulating OsGH3-5 and OsBRI1

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    Auxin and brassinosteroid (BR) are important phytohormones for controlling lamina inclination implicated in plant architecture and grain yield. But the molecular mechanism of auxin and BR crosstalk for regulating lamina inclination remains unknown. Auxin response factors (ARFs) control various aspects of plant growth and development. We here report that OsARF19-overexpression rice lines show an enlarged lamina inclination due to increase of its adaxial cell division. OsARF19 is expressed in various organs including lamina joint and strongly induced by auxin and BR. Chromatin immunoprecipitation (ChIP) and yeast one-hybrid assays demonstrate that OsARF19 binds to the promoter of OsGH3-5 and brassinosteroid insensitive 1 (OsBRI1) directing their expression. OsGH3-5-overexpression lines show a similar phenotype as OsARF19-O1. Free auxin contents in the lamina joint of OsGH3-5-O1 or OsARF19-O1 are reduced. OsGH3-5 is localized at the endoplasmic retieulum (ER) matching reduction of the free auxin contents in OsGH3-5-O1. osarf19-TDNA and osgh3-5-Tos17 mutants without erected leaves show a function redundancy with other members of their gene family. OsARF19-overexpression lines are sensitive to exogenous BR treatment and alter the expressions of genes related to BR signalling. These findings provide novel insights into auxin and BR signalling, and might have significant implications for improving plant architecture of monocot crops
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