Effect of sericin blending on molecular orientation of regenerated silk fiber     

Chang Seok Ki  Young Hwan Park 《Fibers and Polymers》2013,14(9):1460-1467

The use of regenerated silk fiber is limited due to its inferior mechanical properties in spite of high potential in a wide variety of applications. Many studies have been conducted in order to improve the mechanical properties of the regenerated silk materials, but no one has so far suggested an obvious solution. Meanwhile, some reports showed evidence that structural development of silk protein can be manipulated by physical interactions between silk fibroin (SF) and silk sericin (SS) during the regeneration process, especially in recrystallization process of SF. Such a hypothesis suggests a promising clue to enhance the mechanical properties of silk-based materials. Therefore, in this study, we tried to elucidate how SS can promote developing the molecular chain orientation of SF, resulting in an improvement of mechanical properties of regenerated silk fiber during spinning process. The tensile properties of the regenerated silk fiber were significantly improved compared to those of pure SF fiber when a proper amount of SS was blend with SF; both tenacity and breaking elongation increased by approximately 30 % and 70 % at three fold draw ratio, respectively. Quantitative analysis of X-ray diffraction and Herman’s orientation coefficient confirmed that such an improvement of tensile property was mainly caused by an increase of molecular orientation induced by sericin during the drawing process.  相似文献   

Effect of topical anesthesia on evaluation of corneal sensitivity and intraocular pressure in rats and dogs     

Jury Kim  Nam‐Soo Kim  Ki‐Chang Lee  Hae‐Beom Lee  Min‐Su Kim  Hyung‐Seop Kim 《Veterinary ophthalmology》2013,16(1):43-46

Objective To determine the effect of 0.5% proparacaine in tonometry by evaluating corneal touch threshold (CTT) and intraocular pressure (IOP). Animal studied Nine rats (18 eyes, Sprague–Dawley) and 10 dogs (20 eyes, Beagle) Procedures The IOP and CTT were measured in each eye before and after topical anesthesia with 0.5% proparacaine. The IOP was evaluated using Tonopen for dogs and Tonolab for rats. The corneal sensitivity was evaluated by CTT through a Cochet–Bonnet aesthesiometer. Results The mean IOP was not significantly changed in rats or dogs before and after topical anesthesia. However, after application of proparacaine, CTT was significantly increased in both animal groups compared with that before application of proparacaine. Conclusion From this study, topical anesthesia was found to significantly lower the corneal sensitivity but have little effect on IOP measurements. In ophthalmologic examination, topical anesthesia can be used to reduce corneal sensation without an effect on IOP.  相似文献   

Amino acid substitutions in gyrA and parC associated with quinolone resistance in nalidixic acid-resistant Salmonella isolates     

Dong Hwa Bae  Ho Jeong Baek  So Jeong Jeong  Young Ju Lee 《Irish veterinary journal》2013,66(1):23

This study was undertaken to identify and characterize amino acid substitutions in gyrA and parC related with quinolone resistance of 27 nalidixic acid-resistant (Na^R) Salmonella isolates collected in poultry slaughterhouses in Korea. A total of 51 Salmonella isolates were detected from 44.8% (47/105) of the total samples from 15 poultry slaughterhouses examined, among which 27 (52.9%) Na^R isolates were detected while ciprofloxacin (Cip) resistance was not present in the isolates. These 27 Na^R isolates of DNA sequencing revealed that it contained three types of gyrA mutations in only D87 codon. Mutations in the D87 codon resulted in substitutions to G in most of the isolates, but D87Y and D87N exchanges were also detected. Although Cip resistance was absent, reduced susceptibility characterized by mutations in gyrA was apparent among Salmonella isolates from poultry slaughterhouses in Korea.  相似文献   

Association of antioxidant vitamins and oxidative stress levels in pregnancy with infant growth during the first year of life     

Hong J  Park EA  Kim YJ  Lee HY  Park BH  Ha EH  Kong KA  Park H 《Public health nutrition》2008,11(10):998-1005

OBJECTIVE: Whereas there are numerous reports in the literature relating the impact of maternal nutritional status on subsequent birth outcome, much less is known about the long-term impact on infant growth after birth. Therefore, we conducted a prospective cohort study to investigate the association of maternal micronutrient status (vitamins A, C and E, folate) and oxidative stress status in pregnancy with infant growth during the first year of life. DESIGN: Prospective cohort study. SETTING: Outpatient clinic of obstetrics, Ewha Womans University Hospital, Seoul, South Korea.Subjects and methodsTwo groups were constructed for this study - the Ewha pregnancy cohort (n = 677) and the infant growth cohort comprising follow-up live newborns of all the recruited pregnant women (n = 317). Maternal serum vitamin and urinary oxidative stress levels were collected and infant weights and heights were measured at birth and at 6 and 12 months after birth. RESULTS: Division of the subjects into folate-deficient and normal groups revealed that infant weight and height at 0, 6 and 12 months were adversely affected by folate deficiency. High maternal vitamin C was associated with increased infant weight and height at birth and after birth.ConclusionOur findings indicate the importance of preventing folate deficiency and supplementing vitamin C during pregnancy.  相似文献   

Protective effect of anthocyanins from black soybean seed coats on UVB-induced apoptotic cell death in vitro and in vivo   总被引：1，自引：0，他引：1  

Tsoyi K  Park HB  Kim YM  Chung JI  Shin SC  Shim HJ  Lee WS  Seo HG  Lee JH  Chang KC  Kim HJ 《Journal of agricultural and food chemistry》2008,56(22):10600-10605

UVB radiation proves to be one of the most relevant environmental risks because of its hazardous effects, such as premature skin aging and especially skin photocarcinogenesis. Anthocyanins, water-soluble pigments present in plants, are known to be powerful antioxidants that help protect plants from UV damage. In this study, we aimed at investigating the protective effect of anthocyanins from black soybean [Glycine max (L.) Merr] seed coats on UVB-induced apoptosis, and furthermore, we investigated the molecular mechanism responsible for regulation of apoptosis in vitro and in vivo. Pretreatment with anthocyanins reduced UVB-induced reactive oxygen species levels and inhibited UVB-induced apoptotic cell death through the prevention of caspase-3 pathway activation and reduction of proapoptotic Bax protein levels. UVB irradiation induced apoptotic cell death, which was inhibited by topical application of anthocyanins in hairless mice. It is concluded that anthocyanins from the seed coat of black soybeans may be useful compounds to modulate UVB-induced photoaging.  相似文献   

Tastes and structures of bitter peptide, asparagine-alanine-leucine-proline-glutamate, and its synthetic analogues     

Kim MR  Yukio K  Kim KM  Lee CH 《Journal of agricultural and food chemistry》2008,56(14):5852-5858

Asn-Ala-Leu-Pro-Glu (NALPE) is a strong bitter peptide with a minimum response threshold (MRT) of 0.074 mM. To elucidate the relationship of spatial structure and bitterness on peptides, NALPE and its analogues, NALPW, NALPS, NALPL, NALPP, NALPD, and NALPR, were synthesized and sensorially evaluated. Structural analysis using computer simulation for each peptide revealed that the presence of a polar group and hydrophobic bitter amino acids, the composition of hydrophobic regions, the spatial orientation of the polar group and hydrophobic regions, and the proximity between polar groups and hydrophobic regions faced within the same plane space may be the major determinants for the taste type and intensity of peptide bitterness.  相似文献   

Potential of indigenous Bacillus spp. as probiotic feed supplements in an extruded low‐fish‐meal diet for juvenile olive flounder,Paralichthys olivaceus     

Kai‐Min Niu  Sanaz Khosravi  Damini Kothari  Woo‐Do Lee  Bong‐Joo Lee  Sang‐Gu Lim  Sang‐Woo Hur  Sang‐Min Lee  Soo‐Ki Kim 《Journal of the World Aquaculture Society》2021,52(1):244-261

A 12‐week feeding trial was designed to assess the probiotic potential of indigenous Bacillus amyloliquefaciens and/or Bacillus subtilis singly or in combination with Bacillus licheniformis in an extruded feed for olive flounder (Paralichthys olivaceus) juveniles. A high fish meal (FM) diet (control) and a low‐FM diet containing an alternative protein blend (30% FM replacement, FM30) were formulated. Three other experimental diets were prepared by inclusion of B. amyloliquefaciens (BA), B. subtilis (BS), or a mixture of B. amyloliquefaciens, B. subtilis, and B. licheniformis (BASL) into FM30 diet, with a final concentration of 10⁶ CFU/g diet. Results indicated that the FM30 diet was well tolerated by flounder, and the overall performance was not affected by dietary treatments. Lysozyme activity and total immunoglobulin level were significantly reduced in flounders when fed with the FM30 diet compared with the BASL and BA diets, respectively. The Bacillus additives neither enriched the relative abundance of the corresponding Bacillus spp. in the relevant gut microbiota of olive flounder nor modulated the presumptive gene functions of the gut microbiome. Despite the absence of growth‐promoting effect, the tested probiotics could still be economically viable for use as immunostimulants in commercial flounder diets with partial FM replacement.  相似文献   

Occurrence and characteristics of enterohemorrhagic Escherichia coli O26 and O111 in calves associated with diarrhea     

Lee JH  Hur J  Stein BD 《Veterinary journal (London, England : 1997)》2008,176(2):205-209

The aims of this study were: (1) to examine whether or not enterohemorrhagic Escherichia coli O26 and O111 (EHEC O26 and O111) are involved in neonatal calf diarrhea; (2) to determine the specific age periods at which the calves are vulnerable to these organisms, and (3) to reveal the biochemical, genetic and cytotoxic characteristics of the isolates. The study investigated the occurrence of EHEC O26 and O111 in calves associated with or without diarrhea. A total of 442 diarrheic and non-diarrheic young calves from 115 different farms were examined. Of the 257 calves with diarrhea, 37 (14.4%) and 32 (12.5%) tested positive for EHEC O26 and EHEC O111, respectively. Of the 185 non-diarrheic calves, 14 (7.6%) and 11 (5.9%) tested positive for EHEC O26 and EHEC O111, respectively. EHEC O26 and O111 were recovered from 14/69 (20%) and 11/69 (16%) diarrheic calves <2-weeks-old, respectively, and no EHEC O26 and O111 were detected in the non-diarrheic claves of this age group, suggesting that EHEC O26 and O111 are possible causes of the disease in infected neonatal calves. However, there were similar rates of occurrence in the diarrheic and non-diarrheic calves in the older animals (particularly, aged >10 weeks). PCR analysis showed that the isolates carried various virulence genes such as Ehly, eae, stx1 and stx2, which highlight the potential importance of these attributes for the infection, colonization and the possible pathogenesis of calf diarrhea. Cytotoxicity analysis revealed that many of the EHEC isolates showed high cytotoxicity to Vero cells, re-emphasizing the potential for cattle being a direct source of EHEC infections in humans.  相似文献   

Determination of Principal Components for Characterizing the Drying of Sea Cucumbers (Stichopus japonicus Selenka) Using Far Infrared Radiation Drying and Hot Air Drying     

Ji Hoon Moon  Dong Hwa Chung  Cheol-Ho Pan 《Journal Of Aquatic Food Product Technology》2017,26(10):1221-1232

Principal component analysis (PCA) and multiple linear regression (MLR) were conducted to characterize the drying of sea cucumber (SC). Far infrared radiation drying (FIRD) and hot air drying (AD) were used to dehydrate SC. Thirteen variables—including the morphological, color, and textural properties of dried SC—were selected for statistical analysis. The analysis of these 13 variables yielded three principal components showing significant correlations. PCA showed that the first three components represented 86.2% of the total variation. The first principal component was primarily related to the morphological properties of SC. The principal components determined by the PCA were more strongly influenced by the morphological variables than by the drying method. Of the morphological variables, the weight of SC had the strongest influence on the drying time and rehydration ratio of FIRD and AD.  相似文献   

Vibrio harveyi associated with deep skin ulcer in river puffer, Takifugu obscures, exhibited in a public aquarium     

Kyoung Mi Won  Ki Hong Kim  & Soo Il Park 《Aquaculture Research》2009,40(8):963-967

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