BIOMECHANICAL RESEARCH ON THE RADIAL CORRUGATION STRUCTURE OF PROSTERNAL TYMPANAL MEMBRANES IN THE PARASITOID FLY ORMIA OCHRACEA

Qingsheng Wang,Na Ta,Zhushi Rao 한국소음진동공학회 2008 한국소음진동공학회 국제학술대회논문집 Vol.2008 No.7

Proteolysis Characteristics of Sarcoplasmic, Myofibrillar, and Stromal Proteins Separated from Grass Carp and Antioxidant Properties of Their Hydrolysates

Haiyan Wang,Fenglan Zhang,Jin Cao,Qingsheng Zhang,Zhirong Chen 한국식품과학회 2013 Food Science and Biotechnology Vol.22 No.2

Proteolysis of grass carp sarcoplasmic, myofibrillar,and stromal proteins by 5 commercial proteases were studied. Sarcoplasmic and myofibrillar protein could be well hydrolyzed by Alcalase 2.4 L to reach high protein recoveries (PR) (71.86±2.46 and 80.77±3.05%, respectively),while the maximum PR for stromal protein was only 42.83±2.84%. However, stromal hydrolysates, containing mostly 6-10 kDa fraction, exhibited higher ·OH scavenging activities due to its high content of antioxidant-assisting amino acids. Alcalase 2.4 L and pancreatin 6.0, which produced hydrolysates with relative high degree of hydrolysis (DH), were used for further hydrolysis of whole grass carp protein with the assistance of response surface methodology (RSM). The results showed that serine proteases (Alcalase 2.4 L and pancreatin 6.0) could produce sarcoplasmic, myofibrillar, or stromal hydrolysates with relatively high PR, DH, and strong ·OH scavenging activity, which may be used to prepare antioxidant hydrolysates from grass carp.

Thermal Plasma Spheroidization of High-Nitrogen Stainless Steel Powder Alloys Synthesized by Mechanical Alloying

Nikolay G. Razumov,Anatoly A. Popovich,QingSheng Wang 대한금속·재료학회 2018 METALS AND MATERIALS International Vol.24 No.2

This paper presents the results of experimental studies on the treatment of Fe–23Cr–11Mn–1N high-nitrogen stainlesssteel powder alloys, synthesized by the mechanical alloying (MA) of elemental powders in the flow of a thermal plasma. Fe–23Cr–11Mn–1N high-nitrogen stainless steel powder alloys were prepared by MA in the attritor under an argon atmosphere. For spheroidization of Fe–23Cr–11Mn–1N high-nitrogen stainless steel powder alloys, the TekSphero 15 plantmanufactured by Tekna Plasma Systems Inc was used. The studies have shown the possibility of obtaining Fe–23Cr–11Mn–1N high-nitrogen spherical powders steel alloys from the powder obtained by MA. According to the results of a series ofexperiments, it was found that the results of plasma spheroidization of powders essentially depend on the size of the fractiondue to some difference in the particle shape and flowability, and on the gas regime of the plasma torch. It is established thatduring the plasma spheroidization process, some of the nitrogen leaves the alloy. The loss rate of nitrogen depends on thesize of the initial particles.

Microstructural evolution of carbon nanotube fibers: deformation and strength mechanism.

Liu, Xia,Lu, Weibang,Ayala, Orlando M,Wang, Lian-Ping,Karlsson, Anette M,Yang, Qingsheng,Chou, Tsu-Wei RSC Pub 2013 Nanoscale Vol.5 No.5

<P>A comprehensive investigation of the mechanical behavior and microstructural evolution of carbon nanotube (CNT) continuous fibers under twisting and tension is conducted using coarse-grained molecular dynamics simulations. The tensile strength of CNT fibers with random CNT stacking is found to be higher than that of fibers with regular CNT stacking. The factor dominating the mechanical response of CNT fibers is identified as individual CNT stretching. A simplified twisted CNT fiber model is studied to illustrate the structural evolution mechanisms of CNT fibers under tension. Moreover, it is demonstrated that CNT fibers can be reinforced by enhancing intertube interactions. This study would be helpful not only in the general understanding of the nano- and micro-scale factors affecting CNT fibers' mechanical behavior, but also in the optimal design of CNT fibers' architecture and performance.</P>

Identification and Antimicrobial Activity Detection of Lactic Acid Bacteria Isolated from Corn Stover Silage

Dongxia Li,Kuikui Ni,Huili Pang,Yanping Wang,Yimin Cai,Qingsheng Jin 아세아·태평양축산학회 2015 Animal Bioscience Vol.28 No.5

A total of 59 lactic acid bacteria (LAB) strains were isolated from corn stover silage. According to phenotypic and chemotaxonomic characteristics, 16S ribosomal DNA (rDNA) sequences and recA gene polymerase chain reaction amplification, these LAB isolates were identified as five species: Lactobacillus (L.) plantarum subsp. plantarum, Pediococcus pentosaceus, Enterococcus mundtii, Weissella cibaria and Leuconostoc pseudomesenteroides, respectively. Those strains were also screened for antimicrobial activity using a dual-culture agar plate assay. Based on excluding the effects of organic acids and hydrogen peroxide, two L. plantarum subsp. plantarum strains ZZU 203 and 204, which strongly inhibited Salmonella enterica ATCC 43971T, Micrococcus luteus ATCC 4698T and Escherichia coli ATCC 11775T were selected for further research on sensitivity of the antimicrobial substance to heat, pH and protease. Cell-free culture supernatants of the two strains exhibited strong heat stability (60 min at 100°C), but the antimicrobial activity was eliminated after treatment at 121°C for 15 min. The antimicrobial substance remained active under acidic condition (pH 2.0 to 6.0), but became inactive under neutral and alkaline condition (pH 7.0 to 9.0). In addition, the antimicrobial activities of these two strains decreased remarkably after digestion by protease K. These results preliminarily suggest that the desirable antimicrobial activity of strains ZZU 203 and 204 is the result of the production of a bacteriocin-like substance, and these two strains with antimicrobial activity could be used as silage additives to inhibit proliferation of unwanted microorganism during ensiling and preserve nutrients of silage. The nature of the antimicrobial substances is being investigated in our laboratory.

Phenotypic and Phylogenetic Analysis of Lactic Acid Bacteria Isolated from Forage Crops and Grasses in the Tibetan Plateau

Huili Pang,Zhongfang Tan,Guangyong Qin,Yanping Wang,Zongwei Li,Qingsheng Jin,Yimin Cai 한국미생물학회 2012 The journal of microbiology Vol.50 No.1

A total of 140 lactic acid bacteria (LAB) strains were isolated from corn, alfalfa, clover, sainfoin, and Indian goosegrass in the Tibetan Plateau. According to phenotypic and chemotaxonomic characteristics, 16S rDNA sequence, and recA gene PCR amplification, these LAB isolates were identified as belonging to five genera and nine species. Corn contained more LAB species than other forage crops. Leuconostoc pseudomesenteroides, Lactococcus lactis subsp. lactis, Lactobacillus brevis, and Weissella paramesenteroides were dominant members of the LAB population on alfalfa, clover, sainfoin, and Indian goosegrass, respectively. The comprehensive 16S rDNA and recA-based approach effectively described the LAB community structure of the relatively abundant LAB species distributed on different forage crops. This is the first report describing the diversity and natural populations of LAB associated with Tibetan forage crops, and most isolates grow well at or below 10°C. The results will be valuable for the future design of appropriate inoculants for silage fermentation in this very cold area.

Identification and Antimicrobial Activity Detection of Lactic Acid Bacteria Isolated from Corn Stover Silage

Li, Dongxia,Ni, Kuikui,Pang, Huili,Wang, Yanping,Cai, Yimin,Jin, Qingsheng Asian Australasian Association of Animal Productio 2015 Animal Bioscience Vol.28 No.5

A total of 59 lactic acid bacteria (LAB) strains were isolated from corn stover silage. According to phenotypic and chemotaxonomic characteristics, 16S ribosomal DNA (rDNA) sequences and recA gene polymerase chain reaction amplification, these LAB isolates were identified as five species: Lactobacillus (L.) plantarum subsp. plantarum, Pediococcus pentosaceus, Enterococcus mundtii, Weissella cibaria and Leuconostoc pseudomesenteroides, respectively. Those strains were also screened for antimicrobial activity using a dual-culture agar plate assay. Based on excluding the effects of organic acids and hydrogen peroxide, two L. plantarum subsp. plantarum strains ZZU 203 and 204, which strongly inhibited Salmonella enterica ATCC $43971^T$, Micrococcus luteus ATCC $4698^T$ and Escherichia coli ATCC $11775^T$ were selected for further research on sensitivity of the antimicrobial substance to heat, pH and protease. Cell-free culture supernatants of the two strains exhibited strong heat stability (60 min at $100^{\circ}C$), but the antimicrobial activity was eliminated after treatment at $121^{\circ}C$ for 15 min. The antimicrobial substance remained active under acidic condition (pH 2.0 to 6.0), but became inactive under neutral and alkaline condition (pH 7.0 to 9.0). In addition, the antimicrobial activities of these two strains decreased remarkably after digestion by protease K. These results preliminarily suggest that the desirable antimicrobial activity of strains ZZU 203 and 204 is the result of the production of a bacteriocin-like substance, and these two strains with antimicrobial activity could be used as silage additives to inhibit proliferation of unwanted microorganism during ensiling and preserve nutrients of silage. The nature of the antimicrobial substances is being investigated in our laboratory.