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排序方式: 共有610条查询结果,搜索用时 31 毫秒
101.
Tzu-Yi Pai Ching-Lin Ho Shyh-Wei Chen Huang-Mu Lo Pao-Jui Sung Shu-Wen Lin Wei-Jia Lai Shih-Chi Tseng Shu-Ping Ciou Jui-Ling Kuo Jing-Tang Kao 《Water, air, and soil pollution》2011,217(1-4):25-33
In this study, seven types of first-order and one-variable grey differential equation model (abbreviated as GM (1, 1) model) were used to predict hourly particulate matter (PM) including PM10 and PM2.5 concentrations in Banciao City of Taiwan. Their prediction performance was also compared. The results indicated that the minimum mean absolute percentage error (MAPE), mean squared error (MSE), root mean squared error (RMSE), and maximum correlation coefficient (R) was 14.10%, 25.62, 5.06, and 0.96, respectively, when predicting PM10. When predicting PM2.5, the minimum MAPE, MSE, RMSE, and maximum R value of 15.24%, 11.57, 3.40, and 0.93, respectively, could be achieved. All statistical values revealed that the predicting performance of GM (1, 1, x (0)), GM (1, 1, a), and GM (1, 1, b) outperformed other GM (1, 1) models. According to the results, it revealed that GM (1, 1) GM (1, 1) was an efficiently early warning tool for providing PM information to the inhabitants. 相似文献
102.
Kim SP Kang MY Kim JH Nam SH Friedman M 《Journal of agricultural and food chemistry》2011,59(18):9861-9869
We investigated antitumor effects of the following four extracts of freeze-dried Hericium erinaceus mushrooms in Balb/c mice intracutaneously transplanted on the backs with CT-26 colon cancer cells: HWE, hot water extraction by boiling in water for 3 h; MWE, microwaving in 50% ethanol/water at 60 W for 3 min; and ACE and AKE, boiling in 1% HCl or 3% NaOH for 2 h. HWE and MWE with a higher content of β-glucans, determined by an assay kit, than ACE and MKE were active in all bioassays. Gas chromatography/mass spectrometry analyses showed the presence of 40, 27, 16, and 13 compounds, respectively, in the four extracts. Daily intraperitoneal (ip) injections of HWE and MWE for 2 weeks significantly reduced tumor weights by 38 and 41%. Tumor regressions were associated with changes in the following cancer biomarkers as compared to phosphate buffer (PBS)-treated control mice: 2.7- and 2.4-fold increases in cytolytic activity of splenic natural killer (NK) cells; restored nitric oxide production and phagocytosis in peritoneal macrophages to 95-98% of normal levels; ~2-fold increase in released pro-inflammatory cytokines tumor necrosis factor-α, interleukin-1β, and interleukin-6 from macrophages; and ~56 and ~60% reductions in the number of blood vessels inside the tumor. The pro-angiogenic factors vascular endothelial growth factor (VEGF), cyclooxygenase 2 (COX-2), and 5-lipoxygenase (5-LOX) were also significantly reduced in mRNA and protein expression by tumor genes. Enzyme-linked immunosorbent assay of tumor cells confirmed reduced expression of COX-2 and 5-LOX (32 and 31%). Reduced COX-2 and 5-LOX expression down-regulated VEGF expression, resulting in inhibition of neo-angiogenesis inside the tumors. The results indicate that induction of NK activity, activation of macrophages, and inhibition of angiogenesis all contribute to the mechanism of reduction of tumor size. 相似文献
103.
Ju Kyoung Oh Jong Pyo Chae Edward Alain B. Pajarillo Sung Hun Kim Min‐Jin Kwak Jong‐Su Eun Seok Woo Chee Kwang‐Youn Whang Sae‐Hun Kim Dae‐Kyung Kang 《Animal Science Journal》2020,91(1)
Gastrointestinal microbiota impact host's biological activities, including digestion of indigestible feed components, energy harvest, and immunity. In this study, fecal microbiota of high body weight (HW) and low body weight (LW) growing pigs at 103 days of age were compared. Principal coordinates analysis separated the HW and LW groups into two clusters, indicating their potential differences between microbial community composition. Although the abundances of two major phyla, Firmicutes and Bacteroidetes, did not significantly differ between the HW and LW groups, some genera showed significant differences. Among them, Peptococcus and Eubacterium exhibited strong positive correlations with body weight (BW) and average daily gain (ADG) (Rho > 0.40), whereas Treponema, Desulfovibrio, Parabacteroides, and Ruminococcaceae_unclassified exhibited strong negative correlations with BW and ADG (Rho < ?0.40). Based on these results, the structure of intestinal microbiota may affect growth traits in pigs through host–microbe interactions. Further in‐depth studies will provide insights into how best to reshape host–microbe interactions in pigs and other animals as well. 相似文献
104.
These days consumers’ various demands are accelerating research on apparel manufacturing system including automatic measurement,
pattern generation, and clothing simulation. Accordingly, methods of reconstructing human body from point-clouds measured
using a three dimensional scanning device are required for apparel CAD system to support these functions. In particular, we
present in this study a human body reconstruction method focused on two issues, which are the decision of the number of control
point for each sectional curve with error bound and the local knot removal for reducing the unusual concentration of control
points. The approximation of sectional curves with error bounds as an approximation criterion leads all sectional curves to
their own particular shapes apart from the number of control points. In addition, the application of the local knot removal
to construction of human body sectional curves reduces the unusual concentration of control points effectively. The results
may be used to produce an apparel CAD system as an automatic pattern generation system and a clothing simulation system through
the low level control of NUBS or NURBS. 相似文献
105.
Sung Soo Han 《Fibers and Polymers》2005,6(3):219-223
Water-soluble chitin (WSC) was prepared by carefully deacetylating chitins to about 50% of N-acetyl content. Topical formulations
based on WSC were prepared and their effects on wound healing were evaluated on a rabbit ear model. Full-thickness, open skin
wounds were made on the ears of rabbits and WSC ointments were embedded in the open wounds. The application of WSC ointments
significantly accelerated wound healing and wound contraction. The areas of epithelialization and granulation tissues in WSC
ointment group are remarkably larger than those in control group (no treatment) and in placebo group (treated with ointment-base
materials). A large number of grown granulation tissues including dense fibroblast deposition were observed under the thickened
epithelium of the wound treated with WSC ointments. The number of inflammatory cells in WSC ointment group was significantly
decreased compared with those in control and placebo groups, indicating that WSC would give low stimuli to wounds and prevent
excessive scar formation. Neovascularization was the most prominent in WSC ointment group. Wound contraction in WSC ointment
group was much larger than those in control and placebo groups. Overall results demonstrate that the topical formulation based
on WSC is considered to become an excellent dressing as a wound healing assistant. 相似文献
106.
Five yellow disperse dyes were synthesized and their dyeing, fastness and photodegradation behaviors were investigated. It
was found that dyes derived from phenylindole and N-alkylaminobenzene showed dye uptake directly proportional to the dye concentration,
but the build-up of dyes derived from carbazole and pyridone were not good. The wavelength at maximum absorption, molar extinction
coefficient, and the tendency to the photodegradation were strongly dependent on the electron donating ability of the coupling
component. The dye, whose coupling component was phenylindole, possessed the excellent dyeing properties and the high degree
of lightfastness. UVA had an effect on the inhibition of the photodegradation especially for the easily photodegradable dyes. 相似文献
107.
Shuai ZHANG Xin WU Dandan HAN Yong HOU Jianzhuang TAN Sung Woo KIM Defa LI Yulong YIN Junjun WANG 《农业科学与工程前沿(英文版)》2021,8(1):15
108.
Water interactions in polycarbonate films have been studied using fluorescence and NIR Fourier transform spectroscopy. During
water sorption process, the fluorescence emission spectra showed sensitive changes with the peak at 332 nm red shifted by
18 nm with water sorption. This red-shifted peak could be due to phenyl-2-phenoxybezoate, which is one of two major thermal
degradation products in polycarbonate. In the spectra of phenyl-2-phenoxybenzoate in dimethyl formamide solution, a progressive
red shift was also observed with the water addition. By using the NIR spectra, hydrogen-bonding interactions of the sorbed
water with polycarbonate were investigated. It was found that water can be analyzed as free water S0 or single hydrogen bonded water, S1 while double hydrogen bonded water was negligible. During water immersion, most water species which are present as S0 species decrease slightly, with a small increase in S1 species. During desorption, S0 species decrease sharply, while S1 species is reduced gradually. Two examples of S1 structure in water-sorbed polycarbonate are proposed. 相似文献
109.
The structural feature of macromolecular component of dhaincha, cotton stalks, jute fiber, rice straw and wheat straw, which are commonly used in paper pulp production in forest deficient countries, was thoroughly studied. Lignin was isolated by classical Bjorkman method and characterized by elemental and methoxyl analysis, alkaline nitrobenzene oxidation, FTIR and 1H NMR spectroscopy. The C9 formulas for cotton stalks, jute fiber, dhaincha, rice straw and wheat straw were C9H8.95O3.53(OCH3)1.00, C9H8.12O4.03(OCH3)1.65, C9H8.10O4.65(OCH3)1.32, C9H8.58O3.74(OCH3)1.23 and C9H8.31O3.54(OCH3)1.23, respectively. The alkaline nitrobenzene oxidation products showed that syringyl to vanilin ratio of these nonwood varied from 1.1 to 2.9. Jute fiber showed the highest syringyl to vanilin ratio that are consistent with C9 formula. The β-O-4 units in these nonwood lignins had predominately erythro stereochemistry type. The crystalline structure of these nonwood cellulose was also studied using X-ray diffraction and FTIR spectroscopy. The proportions of crystallinity, crystal size were varied from plant to plant. Jute fiber showed the highest proportion of crystallinity (73.4%) and crystal size (4.2 nm). The degree of polymerization of these nonwoods cellulose has also been studied. Degree of polymerization of jute cellulose was also the highest (3875). FTIR spectroscopy showed that these nonwoods cellulose was monoclinic unit cell structure (Iβ). Carbohydrate analysis showed that the main sugar component in the hydrolyzates of these nonwoods were xylose apart from glucose. 相似文献
110.
Hot water extract (HWE) from Pinus radiata bark was fractionated into monomeric polyphenol (MPP), oligomeric proanthocyanidin (OPA), and polymeric proanthocyanidin
(PPA) fractions by monitoring the UV-visible spectrum of the eluted fractions. Nine polyphenols were identified in MPP: three
phenolic acids and six flavonoids. The major compounds of MPP were taxifolin (456 μg/mg), catechins (240 μg/mg), and protocatechuic
acid (46.2 μg/mg). The OPA components ranged from dimers to hexamers. PPA comprised procyanidin (PC, 94%), a small amount
of prodelphinidin (PD, 6%), and also the higher trans configuration, rather than the cis configuration, of C2-C3. The average molecular weight (Mw, Mn), polydispersity (Mw/Mn), and DP of PPA were 3,800 (Mw), 1,200
(Mn), 3.2 and 13, respectively. The potential antioxidant activities of HWE and the three fractions were estimated using proton-
or electron-donating assays containing 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical, 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonate)
(ABTS) radical cation, superoxide anion (O2•−), hydrogen peroxide (H2O2), reducing power and lipid peroxidation. All the bark fractions exhibited potent quenching abilities against both commercially
available radicals (DPPH•, ABTS•+) and chemically induced radicals (H2O2, O2•−), as well as strong reducing power and inhibitory activity of lipid peroxidation. Particularly, OPA showed a hydrogen peroxide
scavenging activity significantly higher (p < 0.05) than that of the other fractions. From 2-thiobarbituric acid reactive substances and ferric thiocyanate assays, PPA
was suspected to act by essentially delaying the formation of hydroperoxide by quenching free oxygen radicals that operates
in oil-in-water emulsion. 相似文献