Friction tests have been carried out on bearing steel friction pairs coated with a-C:H and ta-C under lubricated conditions with 1-hexadecene and pure oleic acid,respectively.Main results show that ta-C leads to the s...Friction tests have been carried out on bearing steel friction pairs coated with a-C:H and ta-C under lubricated conditions with 1-hexadecene and pure oleic acid,respectively.Main results show that ta-C leads to the super-low regime with oleic acid(friction coefficient below 0.01)and that a-C:H is quite well lubricated by 1-hexadecen.Surface analyses by coupling X-ray photoelectron spectroscopy(XPS)and secondary ion mass spectrometry(SIMS)have been carried out in the case of oleic acid with ta-C and a-C:H coatings.Results show that tribochemical reactions have occurred.OH groups terminate the ta-C surface whereas a-C:H is covered by a thin tribofilm and is terminated by oleic acid monolayers.The superlow regime in the case of ta-C is mainly attributed to the presence of the OH-termination.展开更多
A voltammetric determination of possible organic pollutants such as diol and phenolic compounds in water was studied using ferroceneboronic acid（FBA） as a redox-active marker.A cyclic voltammogram of FBA exhibited a...A voltammetric determination of possible organic pollutants such as diol and phenolic compounds in water was studied using ferroceneboronic acid（FBA） as a redox-active marker.A cyclic voltammogram of FBA exhibited a pair of oxidation and reduction peaks at 230 and 170 mV at pH 7.0,respectively,while another pair of redox peaks was observed in the presence of diol or phenolic compounds tested.The results were rationalized based on the formation of boronate esters of FBA with the added compounds.The changes in the redox peak currents were dependent on the concentration of the additives,suggesting a usefulness of FBA in the electrochemical determination of these compounds in water.展开更多
Multitoxin Bt-crops expressing insecticidal toxins with different modes of action, for example, Cry and Vip, are expected to improve resistance management in target pests. While Cry1A resistance has been relatively we...Multitoxin Bt-crops expressing insecticidal toxins with different modes of action, for example, Cry and Vip, are expected to improve resistance management in target pests. While Cry1A resistance has been relatively well characterized in some insect species, this is not the case for Vip3A, for which no mechanism of resistance has yet been identified. Here we applied HT-SuperSAGE to analyze the transcriptome of the gut tissue of tobacco budworm Heliothis virescens (F.) laboratory-selected for Vip3Aa resistance. From a total of 1 324 252 sequence reads, 5 895 126-bp tags were obtained representing 17 751 nonsingleton unique transcripts (UniTags) from genetically similar Vip3Aa-resistant (Vip- Sel) and susceptible control (Vip-Unsel) strains. Differential expression was significant (≥2.5 fold or ≤0.4;P < 0.05) for 1989 sequences (11.2% of total UniTags), where 420 represented overexpressed (OE) and 1569 underexpressed (UE) genes in Vip-Sel. BLASTN searches mapped 419 UniTags to H. virescens sequence contigs, of which, 416 (106 OE and 310 UE) were unambiguously annotated to proteins in NCBI nonredundant protein databases. Gene Ontology distributed 345 of annotated UniTags in 14 functional categories with metabolism (including serine-type hydrolases) and translation/ribosome biogenesis being the most prevalent. A UniTag homologous to a particular member of the REsponse to PAThogen (REPAT) family was found among most overexpressed, while UniTags related to the putative Vip3Aa-binding ribosomal protein S2 (RpS2) were underexpressed. qRT-PCR of a subset of UniTags validated the HT-SuperSAGE data. This study is the first providing lepidopteran gut transcriptome associated with Vip3Aa resistance and a foundation for future attempts to elucidate the resistance mechanism.展开更多
文摘Friction tests have been carried out on bearing steel friction pairs coated with a-C:H and ta-C under lubricated conditions with 1-hexadecene and pure oleic acid,respectively.Main results show that ta-C leads to the super-low regime with oleic acid(friction coefficient below 0.01)and that a-C:H is quite well lubricated by 1-hexadecen.Surface analyses by coupling X-ray photoelectron spectroscopy(XPS)and secondary ion mass spectrometry(SIMS)have been carried out in the case of oleic acid with ta-C and a-C:H coatings.Results show that tribochemical reactions have occurred.OH groups terminate the ta-C surface whereas a-C:H is covered by a thin tribofilm and is terminated by oleic acid monolayers.The superlow regime in the case of ta-C is mainly attributed to the presence of the OH-termination.
基金supported in part by a Grant-in-Aid (Asia-Africa Program) from Tohoku University
文摘A voltammetric determination of possible organic pollutants such as diol and phenolic compounds in water was studied using ferroceneboronic acid（FBA） as a redox-active marker.A cyclic voltammogram of FBA exhibited a pair of oxidation and reduction peaks at 230 and 170 mV at pH 7.0,respectively,while another pair of redox peaks was observed in the presence of diol or phenolic compounds tested.The results were rationalized based on the formation of boronate esters of FBA with the added compounds.The changes in the redox peak currents were dependent on the concentration of the additives,suggesting a usefulness of FBA in the electrochemical determination of these compounds in water.
文摘Multitoxin Bt-crops expressing insecticidal toxins with different modes of action, for example, Cry and Vip, are expected to improve resistance management in target pests. While Cry1A resistance has been relatively well characterized in some insect species, this is not the case for Vip3A, for which no mechanism of resistance has yet been identified. Here we applied HT-SuperSAGE to analyze the transcriptome of the gut tissue of tobacco budworm Heliothis virescens (F.) laboratory-selected for Vip3Aa resistance. From a total of 1 324 252 sequence reads, 5 895 126-bp tags were obtained representing 17 751 nonsingleton unique transcripts (UniTags) from genetically similar Vip3Aa-resistant (Vip- Sel) and susceptible control (Vip-Unsel) strains. Differential expression was significant (≥2.5 fold or ≤0.4;P < 0.05) for 1989 sequences (11.2% of total UniTags), where 420 represented overexpressed (OE) and 1569 underexpressed (UE) genes in Vip-Sel. BLASTN searches mapped 419 UniTags to H. virescens sequence contigs, of which, 416 (106 OE and 310 UE) were unambiguously annotated to proteins in NCBI nonredundant protein databases. Gene Ontology distributed 345 of annotated UniTags in 14 functional categories with metabolism (including serine-type hydrolases) and translation/ribosome biogenesis being the most prevalent. A UniTag homologous to a particular member of the REsponse to PAThogen (REPAT) family was found among most overexpressed, while UniTags related to the putative Vip3Aa-binding ribosomal protein S2 (RpS2) were underexpressed. qRT-PCR of a subset of UniTags validated the HT-SuperSAGE data. This study is the first providing lepidopteran gut transcriptome associated with Vip3Aa resistance and a foundation for future attempts to elucidate the resistance mechanism.
