157 research outputs found

    Phthalocyanine-based discotic liquid crystals switching from a molten alkyl chain type to a flying-seed-like type

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    first published on 29 Jun 2017We have synthesised a series of phthalocyanine-based discotic liquid crystals, (m-CnOPhO)(8)PcCu (n = 1-20: 2a-o), and investigated their mesomorphism by using a polarizing optical microscope (POM), a differential scanning calorimeter (DSC) and a temperature-dependent small angle X-ray diffractometer. We found that each of the derivatives 2a-o shows mesomorphism. However, the mesomorphism of the (m-CnOPhO)(8)PcCu derivatives strongly depends on the alkoxy chain length (n). The mesomorphism of the short chain-substituted derivatives 2a-e for n = 1-5 is a flying-seed-like type induced by flip-flop of the peripheral bulky substituents, whereas the mesomorphism of the long chain-substituted derivatives 2j-o for n = 10-20 is a conventional molten alkyl chain type induced by melting of the long alkyl chains. The moderately long chain derivatives (2f-i) for n = 6-9 in between show both types of mesophases. The detailed temperature-dependent X-ray diffraction measurements were carried out for three representative derivatives, 2b (n = 2 for n = 1-5), 2h (n = 8 for n = 6-9), and 2o (n = 20 for n = 10-20). As a result, we revealed that the Col(ro)(P2m) mesophase in 2b (n = 2) gave a halo denoted as Halo(arom). at d congruent to 5.2 angstrom due to flip-flop of the bulky aromatic substituents, and that the Colho mesophase in 2o (n = 20) gave a halo denoted as Halo(alkyl) at d congruent to 4.6-4.8 angstrom due to melting of the long alkyl chains. Therefore, we can distinguish the type of mesophase from Halo(arom). and Halo(alkyl). Very interestingly, the (m-C8OPhO)(8)PcCu (2h) derivative having moderately long alkyl chains gave Halo(alkyl) at about 4.8 angstrom in the lower temperature mesophase of Col(ho), but Halo(arom). at about 5.2 angstrom in the higher temperature mesophase of Col(ro)(P2(1)/a). This means that melting of the alkyl chains induces the Col(ho) phase in the lower temperature region, but that flip-flop of the bulky aromatic substituents induces the Col(ro)(P2(1)/a) phase in the higher temperature region. This unusual reverse phase transition sequence from a higher symmetry of the Col(h) mesophase to a lower symmetry of the Col(r) mesophase on a heating stage is attributable to such a unique stepwise melting of these two different types of substituents. To the best of our knowledge, this mesogen (2h) is the first example switching mesomorphism from the molten alkyl chain type to the flying-seed-like type in a discotic liquid crystal.ArticleJOURNAL OF MATERIALS CHEMISTRY C. 5(29):7297-7306 (2017)journal articl

    Study on Internal Supersonic Flows with Pseudo shock Wave Using Liquid Crystal Flow Visualization Method

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    AbstractThe flow visualization technique using shear-sensitive liquid crystal is applied to the investigation of a Mach 2 internal supersonic flow with pseudo-shock wave (PSW) in a pressure vacuum supersonic wind tunnel. It provides qualitative information mainly concerning the overall flow structure, such as the turbulent boundary layer separation, reattachment locations and the dimensionalities of the flow. Besides, it can also give understanding of the surface streamlines, vortices in separation region and the corner effect of duct flow. Two kinds of crystals with different viscosities are used in experiments to analyze the viscosity effect. Results are compared with schlieren picture, confirming the effectiveness of liquid crystal in flow-visualization

    A comparison of Kato-Katz technique to three other methods for diagnosis of Amphimerus spp. liver fluke infection and the prevalence of infection in Chachi Amerindians of Ecuador

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    Background Recently, a high prevalence of infection by the liver fluke Amphimerus spp. has been documented in the Chachi Amerindians of Ecuador. For diagnosis, no studies exist that compare the sensitivity of different coproparasitological detection techniques. The present study compares the Kato-Katz technique with three other coproparasitological methods for detecting eggs of Amphimerus in stools, as well as determines the prevalence of infection in Chachi residents in a Tropical rain forest area in the northwest coast of Ecuador. Methodology/Results A total of 105 samples, utilizing the Kato-Katz technique (KK), the spontaneous sedimentation technique in tube (SSTT), the formalin-ether concentration technique (FEC), and direct smear microscopy (DM), were examined. Combining the four methods (fixed ÂȘgoldÂș standard), 38 samples were positive with a prevalence of infection of 36.2%. The sensitivities of individual methods were 71%, 58%, 50% and 3% for KK, SSTT, FEC, and DM respectively. Our results indicated that KK alone had the best performance, detecting 27 (71%) of the 38 positive samples. The combination of KK and SSTT detected amphimeriasis in 36 (95%) samples, and KK and FEC in 31 (82%) samples. Conclusions DM showed the lowest sensitivity, which raises concern for its value, because it is the standard technique for stool examination for detection of parasites in both public and private laboratories in Ecuador. SSTT alone detected eggs in 22 samples (58%) and would be recommended for field studies because of its simplicity. Performing two techniques on a single sample enhances the detection of Amphimerus infection. Its sensitivity is relative to a fixed ÂȘgoldÂș standard, determined as the combined results of the four techniques performed. This study confirms the high prevalence of human infection by Amphimerus in the indigenous Chachi group where the first human cases were described.CUP 91750000.0000.374072KAKENHI: Grant No.16H0582

    Hypolobocera guayaquilensis (Decapoda: Pseudothelphusidae): A New Crab Intermediate Host of Paragonimus mexicanus in ManabĂ­ Province, Ecuador

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    To determine that Paragonimus sp. is actively transmitted in a tropical area of the Pacific region of Ecuador where human cases of pulmonary paragonimiasis have recently been documented, a total of 75 freshwater crabs were collected from 2 different streams in the Pedernales area of ManabĂ­ Province, Ecuador. All collected crabs were identified as Hypolobocera guayaquilensis based on morphological characteristics of the male gonopods. The hepatopancreas of each crab was examined by compressing it between 2 glass plates followed by observation under a stereomicroscope. Excysted Paragonimus metacercariae were detected in 39 (52.0%) crabs and their densities varied from 1 to 32 per infected crab. There was a positive relationship between crab size and metacercarial density. Sequences of the second internal transcribed spacer region of the ribosomal RNA gene of the Paragonimus metacercariae obtained in this study were identical to those of Paragonimus mexicanus deposited in the DDBJ/EMBL/GenBank database. Thus, the present study is the first to confirm that the crab species H. guayaquilensis is the second intermediate host of P. mexicanus in ManabĂ­ Province, Ecuador. Because this crab might be the possible source of human infections in this area, residents should pay attention to improper crab-eating habits related with a neglected parasitic disease, i.e., paragonimiasis

    Paragonimus westermani infection mimicking recurrent lung cancer: A case report

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    AbstractHerein, we report a case of Paragonimus westermani infection, which required differentiation from recurrent lung cancer. A 66-year old Japanese man with a history of lung cancer who had undergone a lobectomy was referred to our clinic for treatment of cough, sputum, dyspnea, and a right pulmonary nodule. He had previously eaten seafood he visited China. P. westermani infection was confirmed by the presence of antibody against P. westermani antigen in the patient's serum and eggs in his sputum. Eventually, molecular identification by PCR-restriction fragment length polymorphism analysis and sequencing confirmed that the patient was infected with triploid forms of P. westermani

    KEY FACTORS FOR THE SEPARATION OF SILICON AND IRON DURING PHOSPHORUS RECOVERY FROM SLAG DISCHARGED FROM THE DOUBLE-SLAG REFINING PROCESS

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    In the present study, we developed a technology for concentrating and recovering phosphorus from slag-like phosphorus-containing unused resources and applied it to slag discharged during the latest steelmaking process, that is, double-slag refining process (DRP). The technology we developed consists of the following four processes: Process (1) is the initial acid elution; Process (2) involves alkali precipitation; Process (3) is the second acid elution; and, Process (4) utilizes ion-exchange. In Process (1), the addition of DPR slag to 0.5 M of a nitric acid solution for 24 min resulted in sufficient phosphorus dissolution. In Process (2), ammonia was added to the dissolved solution, and phosphorus was precipitated with high efficiency. The timing of the addition of ammonia significantly influenced the removal of silicon and iron, which would have been inconvenient to accomplish in subsequent processes. In Process (3), the precipitation obtained in Process (2) was re-dissolved in a nitric acid solution. The dissolution of phosphorus together with other elements progressed sufficiently, and we confirmed that silicon could be completely separated as silica by using high-concentration nitric acid at this stage. The fact that silicon could be removed during Process (3) was an important finding, since silicon could not have been separated in the Process (4). In Process (4), by passing the phosphorus-containing solution obtained in Process (3) through an ion exchange resin, elements other than phosphorus and silicon could be removed, which confirms that the range of applications for this technology could be expanded

    Liver fluke infections by Amphimerus sp. (Digenea: Opisthorchiidae) in definitive and fish intermediate hosts in ManabĂ­ province, Ecuador

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    This work is licensed under a Creative Commons Attribution 4.0 International License.Amphimerus sp. is a fluke that dwells in the biliary tracts of vertebrate definitive hosts including humans, domestic, and wild mammals in Latin America. Opisthorchiid liver infections are rarely studied in the Americas confirming its status as a neglected tropical disease. In Ecuador, small trematode eggs were reported in human cases from the province of Manabí in 1949, and recently, Amphimerus sp. adults were recovered from human and reservoir hosts in the province of Esmeraldas. Due to the lack of research on the infectious sources of Amphimerus sp. in the continent, we have developed a series of epidemiological studies with parasitological and molecular techniques to elucidate the endemicity of opisthorchiid fluke infections. We developed a cross-sectional study in three communities at Pedro Pablo Gómez parish in the province of Manabí, Ecuador. We examined a total of 176 fecal samples to detect opisthorchiid eggs, and four fish species to find opisthorchiid metacercariae. To study adult worms, we treated and purged seven patients in a family and dissected the livers of a dog and a cat infected. We observed morphological features of adults and metacercariae and used polymerase chain reaction with restricted fragment length polymorphism (PCR-RFLP) and DNA sequencing of a section of the ITS2 gene for identification. Small trematode eggs were detected in 63 (35.8%) out of 176 fecal samples of residents in the three study sites. Adult opisthorchiid flukes were recovered from human patients, a dog and a cat, and they were morphologically and molecularly identified as Amphimerus sp. Opisthorchiid metacercariae were also identified molecularly as Amphimerus sp. in four fish species, i.e., Rhoadsia altipinna, Bryconamericus bucay, Andinoacara rivulatus, and Piabucina aureoguttata. Metacercariae of the heterophyid Haplorchis pumilio were also found in the four fish species examined. This is the first study to confirm the current endemicity of Amphimerus sp. in Pedro Pablo Gómez, Manabí, Ecuador. The adult worms isolated here shared morphological characteristics with previous Amphimerus sp. descriptions and were molecularly similar to Amphimerus sp. described in the province of Esmeraldas. Moreover, this study is the first to document four fish species as infection sources of Amphimerus sp. detected via a molecular protocol targeting the metacercariae of the parasite. Fish species identified here should be targeted for public health campaigns to avoid further human liver-fluke infections by Amphimerus sp. or potential intestinal-fluke infections by H. pumilio or others.Japan Society for the Promotion of Science (25305011 and 16H05820)Emerging and Re-emerging Infectious Diseases from the Ministry of Health, Labour and Welfare, Japanese government (H23-Shinko-ippan-014 and H26-Shinko-ippan-009)Japan Agency for Medical Research and Development (20fk0108136j0101)Dirección General de Investigaciones, Universidad de las Américas, Quit

    The Anisakis Transcriptome Provides a Resource for Fundamental and Applied Studies on Allergy-Causing Parasites.

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    BACKGROUND: Food-borne nematodes of the genus Anisakis are responsible for a wide range of illnesses (= anisakiasis), from self-limiting gastrointestinal forms to severe systemic allergic reactions, which are often misdiagnosed and under-reported. In order to enhance and refine current diagnostic tools for anisakiasis, knowledge of the whole spectrum of parasite molecules transcribed and expressed by this parasite, including those acting as potential allergens, is necessary. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we employ high-throughput (Illumina) sequencing and bioinformatics to characterise the transcriptomes of two Anisakis species, A. simplex and A. pegreffii, and utilize this resource to compile lists of potential allergens from these parasites. A total of ~65,000,000 reads were generated from cDNA libraries for each species, and assembled into ~34,000 transcripts (= Unigenes); ~18,000 peptides were predicted from each cDNA library and classified based on homology searches, protein motifs and gene ontology and biological pathway mapping. Using comparative analyses with sequence data available in public databases, 36 (A. simplex) and 29 (A. pegreffii) putative allergens were identified, including sequences encoding 'novel' Anisakis allergenic proteins (i.e. cyclophilins and ABA-1 domain containing proteins). CONCLUSIONS/SIGNIFICANCE: This study represents a first step towards providing the research community with a curated dataset to use as a molecular resource for future investigations of the biology of Anisakis, including molecules putatively acting as allergens, using functional genomics, proteomics and immunological tools. Ultimately, an improved knowledge of the biological functions of these molecules in the parasite, as well as of their immunogenic properties, will assist the development of comprehensive, reliable and robust diagnostic tools.This work was supported by a ‘Collaborations Across Boundaries’ grant and a seed grant from the Centre of Biodiscovery and Molecular Development of Therapeutics, James Cook University (FJB and CC). ALL is an Australian Research Council (ARC) Future Fellow and his laboratory is supported by grants from the National Health and Medical Research Council of Australia (NHMRC). Research in the CC laboratory is supported by grants from the Isaac Newton Trust/Wellcome Trust/University of Cambridge (grant number PNVM/GAAB) and the Royal Society (grant number PNAG/428)

    MOLECULAR DISCRIMINATION BETWEEN INDIVIDUAL METACERCARIAE OF PARAGONIMUS HETEROTREMUS AND P. WESTERMANI OCCURRING IN THAILAND

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    Abstract. To accurately discriminate between individual metacercariae of Paragonimus heterotremus and P. westermani occurring in Thailand, polymerase chain reaction (PCR)-based molecular methods were established and subjected to an evaluation. We first amplified and sequenced the second internal transcribed spacer (ITS2) region of the nuclear ribosomal DNA of the two species. Based on their nucleotide differences, P. heterotremus and P. westermani were unequivocally discriminated from each other. These nucleotide differences were further utilized to select the ApaL1 endonuclease site for PCR-restriction fragment length polymorphism (PCR-RFLP) analyses and to design species-specific primers for multiplex PCR reactions. Both PCR-RFLP and multiplex PCR methods allowed a more rapid and labor-effective species discrimination. Furthermore, the multiplex PCR method enabled the most efficient discrimination because species identification involved a single round of PCR in a single tube. In Thailand, P. heterotremus is the only species affecting humans. Thus, the methods established in the present study can be used as reliable tools to identify the lung fluke metacercariae that cause human disease. primers. All of these methods utilize nucleotide differences in the second internal transcribed spacer (ITS2) of the nuclear ribosomal DNA (rDNA) for dicrimination between the two species. In the present study, we focused on the lung flukes occurring in Thailand and applied the methods for species discrimination between individual metacercariae of P. heterotremus and P. westermani. MATERIALS AND METHODS Parasite material and DNA isolation The metacercariae of P. heterotremus and P. westermani DNA amplification, restriction digestion and sequencing The rDNA region spanning the ITS2 from individual metacercariae of the two species was amplified by PCR using the primers, 3S (forward, 5'-GGTACCGGTGGATCACTCGGCTCGTG-3') and A28 (reverse, 5'-GGGATCCTGGTTAGTTTCTTTT CCTCCGC-3'). These primers were designed on the basis of the conserved rDNA sequences of the Schistosoma specie

    LAMPhimerus: a novel LAMP assay for detecting Amphimerus sp. DNA in human stool samples

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    [EN]Amphimeriasis, a fish-borne zoonotic disease caused by the liver fluke Amphimerus spp., is a highly prevalent parasitic infection affecting an indigenous Amerindian group, the Chachi, living in rural and remote tropical areas along the RÔÂo Cayapas and its tributaries in the north-western coastal rainforest of Ecuador. Very little is known about the clinical course and treatment of this disease, and the only method for diagnosing it is the parasitological microscopic detection of eggs from Amphimerus spp. in patients' stool samples. This method lacks sensitivity, and the morphology of the eggs may be confounded with other liver and intestinal flukes. New diagnostic tools that can improve the sensitivity and specificity for diagnosing Amphimerus spp. infection would be desirable. At present, LAMP technology shows all the characteristics required of a real-time assay with simple operation for potential use in the clinical diagnosis of infectious diseases, particularly in the field conditions in developing countries for most neglected tropical diseases. In this study, we developed and successfully evaluated a LAMP assay for detecting Amphimerus sp. in human stool samples. After further validation, our LAMP assay (LAMPhimerus) could be readily adapted for effective field diagnosis and disease surveillance in amphimeriasis- endemic areas
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