The teacher's pets are a common occurrence in the field of education. To investigate the preferences teachers exhibit toward certain children, the study focused on kindergarten teachers and employed ...a mixed research methodology. Initially, qualitative interviews were conducted with 15 kindergarten teachers to identify specific criteria influencing teacher preferences. Subsequently, A comprehensive model of teacher's pets was developed through a questionnaire survey involving 463 participants. This model encapsulated 32 distinct indicators, categorized into 7 types: children with good appearance (GA), exceptional abilities (OA), commendable conduct (GC), proactive and enthusiastic demeanor (PE), compliant and carefree nature (OC), children from vulnerable groups (VC), and those influenced by their parents (PI). The resulting model demonstrated a sound structure. Not only did it validate existing findings, but it also expanded upon the identified types of teacher's pets. An analysis based on game theory revealed the weighted combinations, highlighting the top three types of teacher's pets: children influenced by parental factors (24.3%), proactive and enthusiastic individuals (15.7%), and obedient, carefree children (14.8%), respectively. Conversely, the representation of vulnerable-concerned children (11.1%) was the lowest among the identified types.
The purpose of this study was to determine cross-protection between HEV genotypes 1 and 4, which are prevalent in China. Fecal suspensions of genotypes 1 and 4 from patients, as well as genotype 4 ...from swine, were inoculated intravenously into rhesus macaques. Each inoculum contained 5 x 10⁴ genome equivalents of HEV. After infection, serum and fecal samples were collected serially and the levels of alanine aminotransferase (ALT) and anti-HEV IgG and IgM in sera, and HEV RNA in fecal samples, were measured. Liver biopsies were carried out. All the infected monkeys (12/12) developed anti-HEV IgG and exhibited fecal shedding of virus. IgM was detected in 11 of 12, and ALT elevation occurred about 2-6 weeks post-inoculation in 10 of 12, infected monkeys. Hepatic histopathology was consistent with acute viral hepatitis and the ORF2 antigen of HEV was detected in the granular cytoplasm of hepatocytes by immunohistochemistry. After recovery from their initial HEV infection, the monkeys were challenged with a heterologous genotype or heterologous source of HEV and monitored for hepatitis and fecal shedding. Previous infection with HEV completely or partially protected against subsequent challenge with a heterologous virus, because 7 of 11 monkeys did not develop HEV infection or shed virus in the feces, and none of them developed hepatitis or exhibited ALT elevation or liver biopsy findings of hepatitis. In conclusion, previous HEV infection may give rise to cross-genotype and cross-host-species protection. J. Med. Virol. 80:824-832, 2008.
Ethylene is important in the ripening of apple fruit and different cultivars of apple show very different ripening patterns. The patterns of expression of the currently known genes for ethylene ...synthesis and perception in apple were examined for the summer apple, ‘Sunrise’ (SR), and the later season ‘Golden Delicious’ (GD). Comparisons were made during the last 4 weeks of maturation on the tree and after post-harvest ripening using reverse transcriptase quantitative PCR. Increases in gene expression for ACC synthase 1 (
ACS1) and ACC Oxidase 1 (
ACO1) were 1000- and 10,000-fold, respectively, for both cultivars confirming the importance of these genes in the climacteric ethylene burst.
ACS1 levels remained below detection level until the ripening stage. Additional apple genes for ACS and ACO did not appear to contribute to this ripening-associated ethylene.
ACS3 gene expression in both cultivars increased 100-fold during maturation and reached near maximum levels a full week before commercial harvest. Unique DNA sequences for apple ethylene receptors
ETR2 and
ETR5 and ethylene control element
CTR1 were determined. Expression of four ethylene receptors (
ETR1,
2,
5 and
ERS1) and two control elements,
CTR1 and
EIN2, were evaluated. Only small changes (less than 5-fold) were observed for these perception elements. Splice variants of
CTR1 did not appear to be differentially expressed in these tissues. Genes for
ACO3 and
ERS1 (in GD) responded in a fashion consistent with feedback inhibition of ethylene production in ripening tissue. Differences between the cultivars included a more gradual increase for
ACO1 in GD, an increase in
ERS1 for GD upon ripening that was not seen in SR, and a larger decrease in expression of
CTR1 for GD compared with SR.
Department of Medicine, Royal Free and University College Medical School, University College London, Royal Free Campus, Rowland Hill Street, London NW3 2PF, UK 1
Department of Hepatitis, National ...Institute for the Control of Pharmaceuticals and Biological Products, Temple of Heaven, Beijing, PR China 2
Author for correspondence: Tim Harrison. Fax +44 20 7433 2852. e-mail t.harrison{at}rfc.ucl.ac.uk
Isolates of hepatitis E virus (HEV) have recently been described from China that are distinct from Burmese, Mexican and US viruses and constitute a novel genotype (genotype 4). Here, the complete genomic sequence of a representative isolate of genotype 4 HEV, amplified directly from the stool of an acutely infected patient, is presented. Analysis of the entire sequence confirms our previous conclusion, based upon partial sequence data, that these Chinese isolates belong to a novel genotype. Typical of genetic variation in HEV, most nucleotide substitutions occur in the third base of the codon and do not affect the amino acid sequence. The genotype 4 virus is unusual in that a single nucleotide insertion in the ORF 3 region changes the initiation of ORF 3, and perhaps also ORF 2. The consequences of these changes are discussed.
Cobalt-enriched zeolite (CoNaX) nanocontainers, synthesized by ion-exchange reactions of zeolite X (NaX) and Co(NO3)2, were used as inhibitor additives to improve the corrosion protection of a ...sol-gel coating. A dispersion of CoNaX zeolite was uniform in the sol-gel coating and caused no defects. An increase in coating thickness was unapparent with the addition of CoNaX zeolite. Results of tests indicated that the corrosion protective properties of the sol-gel coating were remarkably improved. This was attributed to an enhanced cross-linking density by zeolite particles and a controlled release of Co2+ in CoNaX zeolite. The released Co2+ reacted with OH- from corrosion products, which formed a Co oxide/hydroxide precipitation. The precipitation covered defects and prevented contact of electrolyte with the substrate, which further slowed corrosion processes. CoNaX zeolite provided the coating with long-term inhibitive properties.
Abstract
Polyurethane (PU) coating can provide physical barrier for metal surface, but the penetration of corrosive ions will affect the long-term corrosion resistance of the coating. In order to ...improve the corrosion resistance of the coating, it is necessary to modify the coating to reduce the internal defects of the coating and improve the corrosion resistance of the coating. Using mesoporous silica (SiO
2
) as the carrier to support the corrosion inhibitor 2- mercaptobenzimidazole (MBI), and using the silane coupling agent GPTS as the bridging agent to compound with graphene oxide (GO) to prepare f-GO-MBI @SiO
2
composite nano-materials, f-GO-MBI @SiO
2
composite nano-materials are added to the polyurethane varnish in different proportions, and the f-GO-MBI @SiO
2
modified PU coating is obtained on the surface of carbon steel by spraying method to improve the carbon corrosion resistance of steel substrate. The composition and loading conditions of drug-loaded composite nanomaterials were characterized by fourier infrared spectroscopy (FTIR) and laser particle size analyzer; electrochemical impedance spectroscopy (EIS) and neutral salt spray test were used to study the properties of different coatings corrosion resistance. The results shows that the addition of f-GO-MBI @SiO
2
composite nano-materials significantly improves the corrosion resistance of the coating, the low addition amount will reduce the anti-corrosion effect, and the addition of too high can easily lead to agglomeration of composite nano-materials and produce paint film defects. When the addition amount of f-GO-MBI @SiO
2
is 5 wt%, the low-frequency impedance of the coating is two orders of magnitude higher than that of the pure polyurethane coating, the corrosion spread width at the neutral salt spray scratches is reduced to 1.5 mm, and the coating has the best corrosion resistance.
Polyurethane (PU) coating can provide physical barrier for metal surface, but the penetration of corrosive ions will affect the long-term corrosion resistance of the coating. In order to improve the ...corrosion resistance of the coating, it is necessary to modify the coating to reduce the internal defects of the coating and improve the corrosion resistance of the coating. Using mesoporous silica (SiO2) as the carrier to support the corrosion inhibitor 2- mercaptobenzimidazole (MBI), and using the silane coupling agent GPTS as the bridging agent to compound with graphene oxide (GO) to prepare f-GO-MBI @SiO2 composite nano-materials, f-GO-MBI @SiO2 composite nano-materials are added to the polyurethane varnish in different proportions, and the f-GO-MBI @SiO2 modified PU coating is obtained on the surface of carbon steel by spraying method to improve the carbon corrosion resistance of steel substrate. The composition and loading conditions of drug-loaded composite nanomaterials were characterized by fourier infrared spectroscopy (FTIR) and laser particle size analyzer; electrochemical impedance spectroscopy (EIS) and neutral salt spray test were used to study the properties of different coatings corrosion resistance. The results shows that the addition of f-GO-MBI @SiO2 composite nano-materials significantly improves the corrosion resistance of the coating, the low addition amount will reduce the anti-corrosion effect, and the addition of too high can easily lead to agglomeration of composite nano-materials and produce paint film defects. When the addition amount of f-GO-MBI @SiO2 is 5 wt%, the low-frequency impedance of the coating is two orders of magnitude higher than that of the pure polyurethane coating, the corrosion spread width at the neutral salt spray scratches is reduced to 1.5 mm, and the coating has the best corrosion resistance.
To improve the corrosion resistance on Q235 low carbon steel, in this paper, tetraethyl orthosilicate (TEOS), N-dodecyl trimethoxysilane and γ-(2,3-epoxypropoxy) propytrimethoxysilane (KH560) were ...used to make organic-inorganic hybrid sol-gel film. Cross cut test adhesion method, neutral salt spray test, electrochemical test and film protective efficiency were taken to value the corrosion resistance property. The corrosion topography was studied by optical microscope. In addition, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) curves and equivalent electric circuit fitting were used to analyze the corrosion mechanism. The cross cut adhesion of sol-gel film can reach 1 class and the protection class can attain 5 class after 72 hours neutral salt spray test. According to the potentiodynamic polarization curve analysis, the corrosion potential of sol-gel film coating sample after 0.5 hours immersion was -0.46 V (vs. SCE) on the 0.1 Hz, and its corrosion current density was 4.74×10-7 A·cm-2. The corrosion potential of bare Q235 low carbon steel plate after 0.5 hours immersion was -0.78 V (vs. SCE) on the 0.1 Hz, and its corrosion current density was 4.75×10-6 A·cm-2. The impedance value on 0.1 Hz (|Z|0.1Hz) (1.27×106 Ω·cm2) of sol-gel film coating sample was more than three orders of magnitude higher than the value of the low carbon steel plate. Even dipping in 3.5 wt. % NaCl for 72 hours, the |Z|0.1Hz value of sol-gel coating sample was still one order of magnitude higher than the low carbon steel plate with 0.5 hours immersion. Sol-gel film with excellent adhesion can significantly improve the corrosion resistance of low carbon steel plate. Sol-gel film can increase the protection efficiency of low carbon steel plate by 90%.
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