149 research outputs found

    Synthesis and characterization of styrene-based polyfluoroacrylate film for hydrophobic/icephobic applications

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    Low surface energy polymeric materials always attract great interest due to their effective non-stick feature when contacting with other materials. In the present work, hydrophobic polyfluoroacrylates (PFAs) were synthesized using styrene, acrylic acid, and heptafluorobutyl acrylate via radical polymerization. The synthesized PFA emulsions had a relatively low curing temperature (e.g. 80 °C), and different molar ratios of heptafluorobutyl acrylate were used to vary the fluorine content in the PFAs. From chemical analysis by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and nuclear magnetic resonance, it was found that the synthesized PFA emulsion exhibited co-polymer structure consisting of the three monomer units. PFA films were deposited on aluminium substrates by spin coating of the synthesized emulsions. The hydrophobicity of the films varied with the fluorine content, and a maximum water contact angle of 121° was achieved under relatively smooth surface condition. Ice adhesion of the PFA films was also evaluated using a centrifugal method, and the ice adhesion strength decreased with the increase of the fluorine content in PFA

    Intra-Familial Phenotypic Heterogeneity and Telomere Abnormality in von Hippel- Lindau Disease: Implications for Personalized Surveillance Plan and Pathogenesis of VHL-Associated Tumors

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    von Hippel-Lindau (VHL) disease is a hereditary cancer syndrome with poor survival. The current recommendations have proposed uniform surveillance strategies for all patients, neglecting the obvious phenotypic varieties. In this study, we aim to confirm the phenotypic heterogeneity in VHL disease and the underlying mechanism. A total of 151 parent-child pairs were enrolled for genetic anticipation analysis, and 77 sibling pairs for birth order effect analysis. Four statistical methods were used to compare the onset age of patients among different generations and different birth orders. The results showed that the average onset age was 18.9 years earlier in children than in their parents, which was statistically significant in all of the four statistical methods. Furthermore, the first-born siblings were affected 8.3 years later than the other ones among the maternal patients. Telomere shortening was confirmed to be associated with genetic anticipation in VHL families, while it failed to explain the birth order effect. Moreover, no significant difference was observed for overall survival between parents and children (p = 0.834) and between first-born patients and the other siblings (p = 0.390). This study provides definitive evidence and possible mechanisms of intra-familial phenotypic heterogeneity in VHL families, which is helpful to the update of surveillance guidelines

    Screening for pathogenic variants in obese cohort using whole-exome sequencing

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    Objective·To screen mutations of key genes in the leptin-melanocyte stimulating hormone (LEP-MSH) pathway by whole-exome sequencing (WES) in the obese cohort.Methods·A total of 119 obese patients aged 1765 years old with body mass index (BMI)≄34 kg/m2, who underwent laparoscopic sleeve gastrectomy from January 2011 to July 2019 at Shanghai Sixth Peopleâ€Čs Hospital, Shanghai Jiao Tong University School of Medicine were collected. The peripheral blood samples of the research subjects were collected, and whole genome DNA was extracted to perform WES. Bioinformatic methods were applied to detect the mutations in 16 genes in the LEP-MSH pathway (ADCY3, AGRP, BDNF, KSR2, LEP, LEPR, MC3R, MC4R, MCHR1, MRAP2, NTRK2, PCSK1, PHIP, POMC, SH2B1, and SIM1). Rare variants with the minor allele frequency in the total population less than 0.02 and in the East Asian population less than 0.01 in the 1000 Genome (1000G), Exome Aggregation Consortium (ExAC) and Genome Aggregation Database (gnomAD) were selected for subsequent analysis. Six pieces of prediction software were used to evaluate the deleteriousness of the mutations. Finally, based on the clinical information of each patient, the pathogenicity of all variants was determined according to the guidelines of America College of Medical Genetics and Genomics (ACMG), and only the "pathogenic", "likely pathogenic", and "uncertain significance" variants were retained.Results·A total of 26 variants, 22 kinds of variants were detected in 24 patients from 119 subjects, all of which were heterozygous mutations. The detected variants included 7 in SH2B1 gene (accounting for 26.92% of the total variants), 4 in MCHR1 gene (accounting for 15.38%), 3 in PHIP gene (accounting for 11.53%), 2 in ADCY3 and LEPR genes (accounting for 7.69%, respectively), and 1 in LEP, NTRK2, AGRP, KSR2, MC3R, MC4R, BDNF, and PCSK1 genes, respectively (accounting for 3.85%, respectively). There were 3 patients having the same mutation site in SH2B1 gene, and 2 patients having the same mutation sites in LEPR gene and MCHR1 gene, respectively. In addition, among these mutations, there were 12 ones not included in the East Asian population in 3 public databases, which were novel mutations in the East Asian population, located in SH2B1 (p.V209I, p.R67C, and p.L149F), KSR2 (p.P155T), LEP (p.D106N), LEPR (p.W132R), PHIP (p.K1461R), BDNF (p.N84S), PCSK1 (p.R282W), NTRK2 (p.T732M), MC3R (p.S71P), and MC4R (p.W174X).Conclusion·A total of 22 kinds of rare variations possibly associated with obesity in the LEP-MSH pathway are detected, 12 of which are novel in the East Asian population

    Genome-Wide Characterization of Trichome Birefringence-Like Genes Provides Insights Into Fiber Yield Improvement

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    Cotton is an important fiber crop. The cotton fiber is an extremely long trichome that develops from the epidermis of an ovule. The trichome is a general and multi-function plant organ, and trichome birefringence-like (TBL) genes are related to trichome development. At the genome-wide scale, we identified TBLs in four cotton species, comprising two cultivated tetraploids (Gossypium hirsutum and G. barbadense) and two ancestral diploids (G. arboreum and G. raimondii). Phylogenetic analysis showed that the TBL genes clustered into six groups. We focused on GH_D02G1759 in group IV because it was located in a lint percentage-related quantitative trait locus. In addition, we used transcriptome profiling to characterize the role of TBLs in group IV in fiber development. The overexpression of GH_D02G1759 in Arabidopsis thaliana resulted in more trichomes on the stems, thereby confirming its function in fiber development. Moreover, the potential interaction network was constructed based on the co-expression network, and it was found that GH_D02G1759 may interact with several genes to regulate fiber development. These findings expand our knowledge of TBL family members and provide new insights for cotton molecular breeding

    Coupling Efficiency Measurements for Long-pulsed Solid Sodium Laser Based on Measured Sodium Profile Data

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    In 2013, a serial sky test has been held on 1.8 meter telescope in Yunnan observation site after 2011-2012 Laser guide star photon return test. In this test, the long-pulsed sodium laser and the launch telescope have been upgraded, a smaller and brighter beacon has been observed. During the test, a sodium column density lidar and atmospheric coherence length measurement equipment were working at the same time. The coupling efficiency test result with the sky test layout, data processing, sodium beacon spot size analysis, sodium profile data will be presented in this paper

    Dual-comb spectroscopy over 100km open-air path

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    Satellite-based greenhouse gases (GHG) sensing technologies play a critical role in the study of global carbon emissions and climate change. However, none of the existing satellite-based GHG sensing technologies can achieve the measurement of broad bandwidth, high temporal-spatial resolution, and high sensitivity at the same time. Recently, dual-comb spectroscopy (DCS) has been proposed as a superior candidate technology for GHG sensing because it can measure broadband spectra with high temporal-spatial resolution and high sensitivity. The main barrier to DCS's display on satellites is its short measurement distance in open air achieved thus far. Prior research has not been able to implement DCS over 20 km of open-air path. Here, by developing a bistatic setup using time-frequency dissemination and high-power optical frequency combs, we have implemented DCS over a 113 km turbulent horizontal open-air path. Our experiment successfully measured GHG with 7 nm spectral bandwidth and a 10 kHz frequency and achieved a CO2 sensing precision of <2 ppm in 5 minutes and <0.6 ppm in 36 minutes. Our results represent a significant step towards advancing the implementation of DCS as a satellite-based technology and improving technologies for GHG monitoringComment: 24 pages, 6 figure

    Quantitative Scintigraphy Evaluated the Relationship between 131I Therapy and Salivary Glands Function in DTC Patients: A Retrospective Analysis

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    Purpose. Quantitative scintigraphy to evaluate salivary gland function changes in patients with differentiated thyroid cancer (DTC) after iodine-131 (131I) treatment. Methods. A total of 458 patients with DTC grouped by sex and age were included. Salivary gland scintigraphy was performed to evaluate salivary gland function before and after 131I treatment. The uptake fraction (UF), uptake index (UI), and excretion fraction (EF) of two pairs of parotid glands and submandibular glands were measured and compared. The Chi-square test was conducted according to function impairment count. Results. Salivary gland function in different age groups and sexes were quite different, especially for women <55 years old, who had decreased UF, UI, and EF of all four glands without basal injury. The secretion or uptake function of some salivary glands with basic function impairment before 131I treatment was increased after iodine treatment. Only a small percentage of males showed reduced functional parameters after several treatments. The most significant difference in the count of impairment for the four salivary glands were the first and third examinations, which was more evident in women. The submandibular gland had the most significant reduction in uptake. Conclusion. Changes in salivary gland function are more common in young females being treated for DTC. Impairment of salivary gland function is correlated with the number of treatments and the cumulative dose of 131I. Some salivary gland functions impaired before 131I treatment were enhanced in the early treatment

    Integrated rocksalt–polyanion cathodes with excess lithium and stabilized cycling

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    Co- and Ni-free disordered rocksalt cathodes utilize oxygen redox to increase the energy density of lithium-ion batteries, but it is challenging to achieve good cycle life at high voltages &gt;4.5 V (versus Li/Li+). Here we report a family of Li-excess Mn-rich cathodes that integrates rocksalt- and polyanion-type structures. Following design rules for cation filling and ordering, we demonstrate the bulk incorporation of polyanion groups into the rocksalt lattice. This integration bridges the two primary families of lithium-ion battery cathodes—layered/spinel and phosphate oxides—dramatically enhancing the cycling stability of disordered rocksalt cathodes with 4.8 V upper cut-off voltage. The cathode exhibits high gravimetric energy densities above 1,100 Wh kg−1 and &gt;70% retention over 100 cycles. This study opens up a broad compositional space for developing battery cathodes using earth-abundant elements such as Mn and Fe

    Upper ocean biogeochemistry of the oligotrophic North Pacific Subtropical Gyre : from nutrient sources to carbon export

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    Subtropical gyres cover 26–29% of the world’s surface ocean and are conventionally regarded as ocean deserts due to their permanent stratification, depleted surface nutrients, and low biological productivity. Despite tremendous advances over the past three decades, particularly through the Hawaii Ocean Time-series and the Bermuda Atlantic Time-series Study, which have revolutionized our understanding of the biogeochemistry in oligotrophic marine ecosystems, the gyres remain understudied. We review current understanding of upper ocean biogeochemistry in the North Pacific Subtropical Gyre, considering other subtropical gyres for comparison. We focus our synthesis on spatial variability, which shows larger than expected dynamic ranges of properties such as nutrient concentrations, rates of N2 fixation, and biological production. This review provides new insights into how nutrient sources drive community structure and export in upper subtropical gyres. We examine the euphotic zone in subtropical gyres as a two-layered vertically structured system: a nutrient-depleted layer above the top of the nutricline in the well-lit upper ocean and a nutrient-replete layer below in the dimly lit waters. These layers vary in nutrient supply and stoichiometries and physical forcing, promoting differences in community structure and food webs, with direct impacts on the magnitude and composition of export production. We evaluate long-term variations in key biogeochemical parameters in both of these euphotic zone layers. Finally, we identify major knowledge gaps and research challenges in these vast and unique systems that offer opportunities for future studies
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