Prediction and interpretation of hydraulic permeability for nonwoven fabrics considering hypothetical 2-D layer     

Seung Jae Ahn  Moo Sung Lee  Dae Young Lim  Jung Nam Im  Seung Goo Lee  Ji Ho Youk  Han-Yong Jeon 《Fibers and Polymers》2013,14(12):2191-2196

The permeability defined by Darcy’s law indicates the degree of ability that a fluid can flow through nonwoven media under a differential pressure in laminar flow. The permeability generally indicates the specific permeability or absolute permeability. On the other hand, if the fluid is water, the permeability indicates the hydraulic conductivity or permeability coefficient. The permeability is one of the important properties for nonwoven media and a prediction of the permeability acts as a bridge between the manufacturing technology and performance requirements. Because capillary channel theory aims to make the flow of fluid easier and more understandable, many models are based on capillary channel theory. On the other hand, the theory has a limitation in that it is unsuitable for high porosity media. In this study, a very thin downstream layer, which was suggested by Lifshutz [9], was introduced to derive a prediction model of hydraulic permeability. Needle-punched and spunbonded nonwoven fabrics with various basis weights were used in the cross-plain water permeability test. From this ‘thin layer’ model, reasonable agreement between the predicted and experimental results was obtained.  相似文献   

Licochalcone A prevents adipocyte differentiation and lipogenesis via suppression of peroxisome proliferator-activated receptor γ and sterol regulatory element-binding protein pathways     

Quan HY  Baek NI  Chung SH 《Journal of agricultural and food chemistry》2012,60(20):5112-5120

Licochalcone A (LA) has been shown to exert multiple pharmacological effects, including anti-inflammatory, antiparasitic, antifungal, anticancer, and osteogenic activities. The present study investigated the ability of LA to suppress the differentiation of 3T3-L1 preadipocytes, and its antiobesity activity was explored using high fat diet (HFD)-fed ICR mice. During the terminal differentiation process, 3T3-L1 preadipocytes were treated with LA, and the lipid contents were quantified along with any changes in the expression of biomarkers associated with adipocyte differentiation and lipogenesis. The results show that LA significantly reduced lipid accumulation and down-regulated the expression of peroxisome proliferator-activated receptor γ, CCAAT/enhancer binding protein α, sterol regulatory element-binding protein 1c, and their target genes (fatty acid binding protein, fatty acid synthase, stearoyl-CoA desaturase 1, and glycerol-3-phosphate acyltransferase). In an animal study, body weight, triglyceride, cholesterol, and nonesterified fatty acid levels in the group given 10 mg/kg LA were significantly decreased by 14.0, 48.2, 58.9, and 73.5%, respectively. Transverse microcomputed tomography indicated that visceral fat depots in LA-treated mice were markedly reduced when compared with those of the HFD control group. In summary, these results suggest that LA exerts an antiobesity effect and that it is a candidate for future clinical trials.  相似文献   

Hericium erinaceus mushroom extracts protect infected mice against Salmonella Typhimurium-Induced liver damage and mortality by stimulation of innate immune cells     

Kim SP  Moon E  Nam SH  Friedman M 《Journal of agricultural and food chemistry》2012,60(22):5590-5596

The present study investigated the antibacterial effect of four extracts from the fruitbody of the edible medicinal mushroom Hericium erinaceus (hot water extract, HWE; microwave/50% ethanol extract, MWE; acid extract, ACE; and alkaline extract, AKE) against murine salmonellosis. The extracts had no effect on Salmonella ser. Typhimurium growth in culture. Nor were the extracts toxic to murine macrophage cells, RAW 264.7. HWE and MWE stimulated uptake of the bacteria into the macrophage cells as indicated by increased colony-forming unit (CFU) counts of the contents of the lysed macrophages infected with Salmonella Typhimurium for 30 and 60 min. Two hours postinfection, the bacterial counts increased in the macrophages, but 4 and 8 h postinfection the HWE- and MWE-treated cells showed greater activity against the bacteria than the control. HWE- and MWE-treated noninfected macrophages had altered morphology and elevated inducible nitric oxide (NO) synthase (iNOS) mRNA expression. In the presence of S. Typhimurium, iNOS mRNA expression was further increased, accompanied by an increase in NO production. Histology assays of the livers of mice infected with a sublethal dose (1 × 10(4) CFU) of S. Typhimurium showed that HWE and MWE, administered by daily intraperitoneal injection, protected against necrosis of the liver, a biomarker of in vivo salmonellosis. The lifespans of mice similarly infected with a lethal dose of S. Typhimurium (1 × 10(5) CFU) were significantly extended by HWE and MWE. β-Glucan, known to stimulate the immune system, was previously found to be present in high amounts in the active extracts. These results suggest that the mushroom extract activities against bacterial infection in mice occur through the activation of innate immune cells.  相似文献   

Sexual dimorphism and sex-differential migration of Little Buntings(Emberiza pusilla)at an East Asian stopover site     

Sook-Young Cho  Hyun-Young Nam  Se-Young Park  Chang-Yong Choi 《中国鸟类》2022,(1):87-93

Sex differences in morphology provide key information for understanding a species'morphological adaptations in relation to the evolution of sexual selection.In ...  相似文献   

Application of ultrasonic treatment to extraction of collagen from the skins of sea bass Lateolabrax japonicus     

Hyun Kyung Kim  Young Ho Kim  Hyun Jin Park  Nam Hyouck Lee 《Fisheries Science》2013,79(5):849-856

This study investigates an efficient method to extract collagen from the skins of sea bass. The ultrasonic treatment (20 kHz with amplitude of 20–80 %) was applied to fish skin for 24 h after the addition of 0.01, 0.05, and 0.1 M acetic acid (1:200 sample/acetic acid, w/v). As a result, the rate (Ki) of the collagen yield increased depending on the amount of acid added, the duration of ultrasonic treatment and the amplitude of the ultrasonic waves. The subunit compositions of the extracted components were analyzed by SDS-PAGE, and the main components were determined as collagen, including the α1 (α3), α2, β, and γ chains. And in addition to collagen, some unknown components were also observed after a longer period of ultrasonic treatment. Therefore, we had to optimize the efficient extraction conditions for pure collagen while minimizing the creation of unknown components. The most effective extraction condition for collagen by ultrasonic treatment was 80 % amplitude with 0.1 M acetic acid for 3 h of treatment. It was found that the component extracted by the ultrasonic treatment was indeed collagen, since there were no changes in the main components of collagen after pepsin treatment.  相似文献   

Factors affecting fish yield and profit in fish pen culture in flooded ricefields     

Nam Cao Quoc  Nico Vromant  Duong Le Thanh  Frans Ollevier 《Aquaculture International》2012,20(5):827-845

In recent years, a rotational system consisting of two rice crops followed by a fish pen culture during the monsoon flood period was adopted in parts of the flood-prone region of the Mekong Delta. In this paper, we use the survey data from 51 fish pen farmers at Co Do and Vinh Thanh district, Can Tho City, to investigate the factors affecting fish yield and profit in such fish pen culture system. The net yield of all stocked fish varies from 377 to 3,782?kg/ha/crop while the return above variable costs varies from ?5.3 to 9.8 million VND/ha/crop. Low fish price at harvest and the difficulty to sell below market sized fish at a period of oversupply are the main problems for fish pen culture. Fish net yield significantly increases with stocking density and is linked with specific polycultures. Common carp and bighead carp perform best in fish pen culture, both in production and profit considerations. Harvest body mass of common carp is mainly limited by increasing common carp stocking density. Therefore, a stocking density of common carp of about 6,000 fish/ha is recommended to obtain the optimum combination of reasonable body masses, and a good price, as well as a high return above fingerling costs.  相似文献   

Assessment of water delivery efficiency in irrigation canals using performance indicators     

Won-Ho Nam  Eun-Mi Hong  Jin-Yong Choi 《Irrigation Science》2016,34(2):129-143

Agricultural water is delivered by open irrigation canals in system of reservoirs with a widespread distribution in South Korea. Traditional irrigation management problems include water distribution systems with less capacity than the peak demand, irregular delivery rates, and low irrigation efficiency and uniformity. It is necessary to strategically compare the estimated irrigation demands with the actual water supplies for decision making in order to maintain the water supply according to the demand. Accurate measurement and monitoring of water distribution systems is essential in order to solve the problems of water efficiency and availability. Auto water level gauges installed at the head and tail sections of each irrigation canal in the Dongjin River were used to measure the discharge during irrigation periods. In this study, we introduced an approach to assess the water delivery performance indicators of the open irrigation canals, which is essential for identifying the key issues for water management improvement. The irrigation efficiencies according to the water delivery performance indicators were measured with an automatic water gauge in the irrigation canals and were calculated from the spatial and temporal distribution of the water supply for the lack of planning in water delivery. The calculated performance indicators are useful to understand the irrigator behavior and general irrigation trends. Analysis of the results yielded insights into possible improvement methods in order to develop water management policies that enable irrigation planners to improve the temporal uniformity and equity in the water distribution.  相似文献   

Effects of ruminal infusion of volatile fatty acids on plasma concentration of growth hormone and insulin in sheep.     

N Matsunaga  N T Arakawa  T Goka  K T Nam  A Ohneda  Y Sasaki  K Katoh 《Domestic animal endocrinology》1999,17(1):17-27

In an initial experiment we observed postprandial changes in plasma concentrations of growth hormone (GH), insulin, glucagon, and somatostatin (SRIF) in sheep. We then examined whether increasing the rumen concentration of volatile fatty acids (VFA) by infusing a VFA mixture at three rates (53.5, 107, and 214 micromol/kg/min for 4 hr) mimicked the postprandial changes in hormone secretion. Feeding significantly (P < 0.05) suppressed the plasma GH concentration for 6 hr, whereas it significantly (P < 0.05) increased plasma concentrations of insulin, glucagon, and SRIF. Plasma glucose levels tended to decrease after feeding but then gradually increased over the prefeeding level (P < 0.05). Intraruminal infusion of the VFA mixture at 107 micromol/kg/min caused similar changes in ruminal VFA concentrations to those seen after feeding. The infusion significantly (P < 0.05) suppressed GH secretion in a dose-dependent manner, whereas it caused a significant (P < 0.05) increase in insulin and glucose concentrations without changing glucagon concentrations. From these results, we conclude that the postprandial change in ruminal VFA concentration may be a physiological signal which modifies GH and insulin secretion in sheep.  相似文献   

Production of phenolic compounds in hairy root culture of tartary buckwheat (Fagopyrum tataricum Gaertn)     

Yong Kyoung Kim  Xiaohua Li  Hui Xu  Nam Il Park  Md Romij Uddin  Jong Yeong Pyon  Sang Un Park 《Journal of Crop Science and Biotechnology》2009,12(1):53-57

Fagopyrum tataricum Gaertn (tartary buckwheat) is an excellent medicinal and nutrient-rich crop. It has a high content of rutin and other phenolic compounds. An experiment was conducted to investigate in vitro production of phenolic compounds from hairy root culture of tartary buckwheat. Hairy root growth was promoted by increasing culture time in MS medium. The highest hairy root growth reached up to 11.2 g/l dry weight at 18 d after placement. Transformation was confirmed by PCR using rol genes, rol A (304 bp), B (797 bp), C (550 bp), and D (1035 bp) genes which is transferred into hairy roots from the Ri-plasmid in Agrobacterium rhizogenes and is responsible for the induction of hairy root from plant species. Rutin, quercetin, (−) epicatechin, (−) catechin hydrate, gallic acid, ferulic acid, chlorogenic acid, and caffeic acid were identified both in hairy and wild type roots of tartary buckwheat. The main compound found in the both types of root was epicatechin followed by rutin. The concentration of phenolic compounds in the hairy roots of tartary buckwheat was several-fold higher compared with wild type roots of same species. Our results indicate that hairy root culture of F. tataricum is a valuable alternative approach for the production of phenolic compounds.  相似文献   

Isolation of Sesquiterpenoids and Steroids from the Soft Coral Sinularia brassica and Determination of Their Absolute Configuration     

Giang Nam Pham  Da Yeun Kang  Min Ju Kim  Se Jong Han  Jun Hyuck Lee  MinKyun Na 《Marine drugs》2021,19(9)

Two undescribed rearranged cadinane-type sesquiterpenoids (1–2), named sinulaketol A-B, together with one new chlorinated steroid (3), one new gorgosterol (4), one known sesquiterpene (5), one known dibromoditerpene (6) and two known polyhydroxylated steroids (7–8) were isolated from the soft coral Sinularia brassica. The structures of these compounds were established by extensive spectroscopic analysis, including HRESIMS, 1D, and 2D NMR spectroscopy. Their absolute configurations were also determined by the ECD calculations and DP4+ probability analysis. Antileishmanial activity of compounds 1–8 was evaluated in vitro against the amastigote forms of Leishmania donovani, in which compounds 3, 6, and 7 inhibited the growth of L. donovani by 58.7, 74.3, 54.7%, respectively, at a concentration of 50 μM. Antimicrobial effect of the isolated compounds were also evaluated against Candida albicans, Staphylococcus aureus, and Escherichia coli. Compound 6, a brominated diterpene, exhibited antimicrobial effect against S. aureus.  相似文献