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1.
1　Introduction　AmatrixA∈Cn×missaidtobecentrohermitianifA =Jn AJm,andskewcentrohermitianifA =-Jn AJm,where Adenotetheconjugateofthema trixAandJlisthepermutationmatrixoforderlwithonesonthecrossdiagonal(bottomlefttotopright)andzeroselsewhere .ThehermitianToeplitzmatricesformanimportantsubclassofcentrohermi tianmatriceswhichoccurnaturallyindigitalsignalprocessingandotherareas ,seeforinstance[1] andreferencetherein .Thecentrohermitianandrelatedmatricesrecentlyplayanimportantroleinthesolu…  相似文献   

2.
Alloying is an effective way to manipulate the composition and physico-chemical properties of functional materials. We demonstrated the syntheses of alloyed Co x Ni1?x O nanocrystals using a nonaqueous approach, with x continuously tuned from 0 to 1 by varying the molar ratios of the cobalt precursor in the reagents. The morphological, structural, and compositional properties of the alloyed Co x Ni1?x O nanocrystals were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), inductively coupled plasma atomic emission spectroscopy (ICP-AES), and energy dispersive X-ray spectroscopy (EDS). The results showed that the cobalt and nickel atoms were homogeneously distributed in the alloyed nanocrystals. The as-prepared Co x Ni1?x O nanocrystals can be applied as the hole-transporting layers in polymer light emitting diodes (PLEDs). Our study provides a good example for the syntheses of alloyed oxide nanocrystals with continuously tunable composition.  相似文献   

3.

Objective

Salmonella enterica remains a major cause of food-borne disease in humans, and Salmonella Typhimurium (ST) contamination of poultry products is a worldwide problem. Since macrophages play an essential role in controlling Salmonella infection, the aim of this study was to evaluate the effect of glycyrrhizic acid (GA) on immune function of chicken HD11 macrophages.

Methods

Chicken HD11 macrophages were treated with GA (0, 12.5, 25, 50, 100, 200, 400, or 800 μg/ml) and lipopolysaccharide (LPS, 500 ng/ml) for 3, 6, 12, 24, or 48 h. Evaluated responses included phagocytosis, bacteria-killing, gene expression of cell surface molecules (cluster of differentiation 40 (CD40), CD80, CD83, and CD197) and antimicrobial effectors (inducible nitric oxide synthase (iNOS), NADPH oxidase-1 (NOX-1), interferon-γ (IFN-γ), LPS-induced tumor necrosis factor (TNF)-α factor (LITAF), interleukin-6 (IL-6), and IL-10), and production of nitric oxide (NO) and hydrogen peroxide (H2O2).

Results

GA increased the internalization of both fluorescein isothiocyanate (FITC)-dextran and ST by HD11 cells and markedly decreased the intracellular survival of ST. We found that the messenger RNA (mRNA) expression of cell surface molecules (CD40, CD80, CD83, and CD197) and cytokines (IFN-γ, IL-6, and IL-10) of HD11 cells was up-regulated following GA exposure. The expression of iNOS and NOX-1 was induced by GA and thereby the productions of NO and H2O2 in HD11 cells were enhanced. Notably, it was verified that nuclear factor-κB (NF-κB) and c-Jun N-terminal kinase (JNK) pathways were responsible for GA-induced synthesis of NO and IFN-γ gene expression.

Conclusions

Taken together, these results suggested that GA exhibits a potent immune regulatory effect to activate chicken macrophages and enhances Salmonella-killing capacity.
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4.
In this paper we give a short survey on a problem on extremal quasiconformal extensions. It had been a conjecture for a long time that the dilatations K0(h) and K1(h) are equal before Anderson and Hinkkanen disproved this by constructing concrete examples of a family of affine mappings of some parallelograms. The problem also engendered many interesting results. At the end of the current paper, we discuss relationships among K0(h), H(h) and K1(h) as a concluding remark.  相似文献   

5.
In plants, lipoxygenases (LOXs) play a crucial role in biotic and abiotic stresses. In our previous study, five 13-LOX genes of oriental melon were regulated by abiotic stress but it is unclear whether the 9-LOX is involved in biotic and abiotic stresses. The promoter analysis revealed that CmLOX09 (type of 9-LOX) has hormone elements, signal substances, and stress elements. We analyzed the expression of CmLOX09 and its downstream genes—CmHPL and CmAOS—in the leaves of four-leaf stage seedlings of the oriental melon cultivar “Yumeiren” under wound, hormone, and signal substances. CmLOX09, CmHPL, and CmAOS were all induced by wounding. CmLOX09 was induced by auxin (indole acetic acid, IAA) and gibberellins (GA3); however, CmHPL and CmAOS showed differential responses to IAA and GA3. CmLOX09, CmHPL, and CmAOS were all induced by hydrogen peroxide (H2O2) and methyl jasmonate (MeJA), while being inhibited by abscisic acid (ABA) and salicylic acid (SA). CmLOX09, CmHPL, and CmAOS were all induced by the powdery mildew pathogen Podosphaera xanthii. The content of 2-hexynol and 2-hexenal in leaves after MeJA treatment was significantly higher than that in the control. After infection with P. xanthii, the diseased leaves of the oriental melon were divided into four levels—levels 1, 2, 3, and 4. The content of jasmonic acid (JA) in the leaves of levels 1 and 3 was significantly higher than that in the level 0 leaves. In summary, the results suggested that CmLOX09 might play a positive role in the response to MeJA through the hydroperoxide lyase (HPL) pathway to produce C6 alcohols and aldehydes, and in the response to P. xanthii through the allene oxide synthase (AOS) pathway to form JA.  相似文献   

6.
For a quantitative understanding of light interaction with fruit tissue, it is critical to obtain two fundamental parameters: the absorption coefficient and the scattering coefficient of the tissue. This study was to investigate the optical properties of kiwifruit tissue at the wavelength of 632.8 nm. The total reflectance and total transmittance of kiwifruit tissue from three parts (including the flesh part, the seed part, and the seed-base part) were measured using a single integrating sphere system. Based on the measured spectral signals, the absorption coefficient μa and the reduced scattering coefficient μs′ of kiwifruit tissue were calculated using the inverse adding-doubling (IAD) method. Phantoms made from Intralipid 20% and India ink as well as a Biomimic solid phantom were used for system validation. The mean values of μa and μs′ of different parts of the kiwifruit were 0.031–0.308 mm?1 and 0.120–0.946 mm?1, respectively. The results showed significant differences among the μa and μs′ of the three parts of the kiwifruit. The results of this study confirmed the importance of studying the optical properties for a quantitative understanding of light interaction with fruit tissue. Further investigation of fruit optical properties will be extended to a broader spectral region and different kinds of fruits.  相似文献   

7.

Objectives

To evaluate the possible photoprotection mechanisms of cyclic and linear electron flux (CEF and LEF) under specific high temperature and high light (HH) stress.

Methods

Six-leaf-stage tomato seedlings (“Liaoyuanduoli”, n=160) were divided into four parts: Part 1, served as control under 25 °C, 500 μmol/(m2·s); Part 2, spayed with distilled water (H2O) under 35 °C, 1000 μmol/(m2·s) (HH); Part 3, spayed with 100 μmol/L diuron (DCMU, CEF inhibitor) under HH; Part 4, spayed with 60 μmol/L methyl viologen (MV, LEF inhibitor) under HH. Energy conversion, photosystem I (PSI), and PSII activity, and trans-thylakoid membrane proton motive force were monitored during the treatment of 5 d and of the recovering 10 d.

Results

HH decreased photochemical reaction dissipation (P) and the maximal photochemical efficiency of PSII (F v/F m), and increased the excitation energy distribution coefficient of PSII (β); DCMU and MV aggravated the partition imbalance of the excitation energy (γ) and the photoinhibition degree. With prolonged DCMU treatment time, electron transport rate and quantum efficiency of PSI (ETRI and Y I) significantly decreased whereas acceptor and donor side limitation of PSI (Y NA and Y ND) increased. MV led to a significant decline and accession of yield of regulated and non-regulated energy Y NPQ and Y NO, respectively. Membrane integrity and ATPase activity were reduced by HH stress, and DCMU and MV enhanced inhibitory actions.

Conclusion

The protective effects of CEF and LEF were mediated to a certain degree by meliorations in energy absorption and distribution as well as by maintenance of thylakoid membrane integrity and ATPase activity.
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8.
In three experiments, we compared the effectiveness of rainbow writing and retrieval practice, two common methods of spelling instruction. In experiment 1 (n?=?14), second graders completed 2 days of spelling practice, followed by spelling tests 1 day and 5 weeks later. A repeated measures analysis of variance demonstrated that spelling accuracy for words trained with retrieval practice was higher than for words trained with rainbow writing on both tests (η p 2 ?=?.49). In experiments 2 (second graders, n?=?16) and 3 (first graders, n?=?12), students completed 2 days of spelling practice followed by a spelling test 1 day later. Results replicated experiment 1; spelling accuracy was higher for words trained with retrieval practice compared with rainbow writing (η p 2 ?=?.42 and .64, respectively). Furthermore, students endorsed both liking and learning from retrieval practice at least as much as (and sometimes more than) rainbow writing. Results demonstrate that retrieval practice is a more useful (and as engaging) training method than is rainbow writing and extend the well-established testing effect to beginning spellers.  相似文献   

9.

Objective

To investigate the effects of corneal thickness distribution and apex position on postoperative refractive status after full-bed deep anterior lamellar keratoplasty (FBDALK).

Methods

This is a retrospective analysis of patients who were diagnosed with advanced keratoconus between 2011 and 2014 in our hospital. The base of the cone in all patients did not exceed the central cornea at a 6-mm range. The FBDALK was performed by a same surgeon. All patients had a complete corneal suture removal and the follow-up records were intact. Patients who had graft-bed misalignment or who were complicated with a cataract or glaucoma were excluded. Uncorrected visual acuity (UCVA), best spectacle corrected visual acuity (BSCVA), and Pentacam examination data were recorded at two years postoperatively. The recorded data included the superior-inferior (S-I) and nasal-temporal (N-T) corneal thickness differences in 2, 4, 6, and 8 mm diameter concentric circles with the corneal apex as the center (S-I2 mm, S-I4 mm, S-I6 mm, S-I8 mm, N-T2 mm, N-T4 mm, N-T6 mm, and N-T8 mm), the linear, X-axis, and Y-axis distance between the corneal pupillary center and the cornea apex, total corneal astigmatism at a zone of 3 mm diameter from the corneal apex (TA3 mm), the astigmatic vector values J0 and J45, and the corneal total higher-order aberration for 3 and 6 mm pupil diameters (HOA3 mm and HOA6 mm). Statistical analysis was performed by SPSS 15.0.

Results

A total of 47 eyes of 46 patients met the criteria and were included in this study. The mean follow-up time was (28±7) months. The mean UCVA was 0.45±0.23 (logMAR) (MAR: minimum angle of resolution) and the mean BSCVA was 0.19±0.15 (logMAR), which were all significantly positively correlated with postoperative TA3 mm and HOA3 mm. The mean S-I corneal thickness differences were (44.62±37.74) μm, and the mean N-T was (38.57±32.29) μm. S-I2 mm was significantly positively correlated with J0 (r=0.31), J45 (r=0.42), HOA3 mm (r=0.37), and HOA6 mm (r=0.48). S-I4 mm and S-I8 mm were significantly positively correlated with HOA3 mm (r=0.30, r=0.40) and HOA6 mm (r=0.46, r=0.35). The X-axis distance between corneal pupillary center and corneal apex was significantly positively correlated with J45 (r=0.29).

Conclusions

In patients with advanced keratoconus after FBDALK, the unevenly distributed thickness at corneal pupillary area and the misalignment of corneal apex and pupillary center might cause significant regular and irregular astigmatism, which affected the postoperative visual quality.
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10.

Objective

The aim of this study was to formulate polymer-based artesunate nanoparticles for malaria treatment.

Methods

Artesunate was loaded with poly(D,L-lactic-co-glycolic acid) (PLGA) by solvent evaporation from an oil-in-water single emulsion. Nanoparticles were characterized by X-ray diffraction and differential scanning calorimetry analyses. In vivo antimalarial studies at 4 mg/kg were performed on Swiss male albino mice infected with Plasmodium berghei. Hematological and hepatic toxicity assays were performed. In vitro cytotoxicity of free and encapsulated artesunate (Art-PLGA) to cell line RAW 264.7 was determined at concentrations of 7.8–1000 μg/ml.

Results

The particle size of the formulated drug was (329.3±21.7) nm and the entrapment efficiency was (38.4±10.1)%. Art-PLGA nanoparticles showed higher parasite suppression (62.6%) compared to free artesunate (58.2%, P<0.05). Platelet counts were significantly higher in controls (305 000.00±148 492.40) than in mice treated with free artesunate (139 500.00±20 506.10) or Art-PLGA (163 500.00±3535.53) (P<0.05). There was no sign of hepatic toxicity following use of the tested drugs. The half maximal inhibitory concentration (IC50) of Art-PLGA (468.0 μg/ml) was significantly higher (P<0.05) than that of free artesunate (7.3 μg/ml) in the in vitro cytotoxicity assay.

Conclusions

A simple treatment of PLGA-entrapped artesunate nanoparticles with dual advantages of low toxicity and better antiplasmodial efficacy has been developed.
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11.
A membrane bioreactor (MBR) was established for treating harbor oily wastewater. It showed good removal performance for chemical oxygen demand (COD), oil content, suspended solids (SS), and other pollutants. However, serious membrane fouling occurred. It was recognized that the extracellular polymeric substances (EPS) accumulated on the membrane surface, especially the proteins, were of great importance for the transmembrane pressure (TMP) increment and membrane fouling. The MBR was optimized via improving aeration rate and reducing the ratio of Ar/Ad (Ar and Ad are the cross-sectional areas of the riser and the downcomer of the MBR). The increasing rate of TMP was slowed, indicating that the optimization strategy could effectively mitigate membrane fouling. Microbial community evolution was monitored and analyzed by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE), cloning, and sequencing of 16S ribosomal ribonucleic acid (rRNA) fragments. Results revealed that low community shift occurred during the whole operational period. Geobacter sp. and Rhodocyclales sp., which have also been identified by other studies in a petroleum refinery wastewater MBR or an infiltration basin receiving highway runoff, dominated in the MBR system throughout. Comamonas sp. was thought to accommodate the lower aeration rate in this study, while Rhodocyclales sp. preferred the higher aeration rate. In addition, during the operational time under high organic loading rate, a few species were present in abundance, and may have been responsible for the good removal performance at this time.  相似文献   

12.
The antioxidant activities and total phenolic content of fermented Salvia miltiorrhiza with fungus Geomyces luteus were investigated. The results revealed that G. luteus fermentation could significantly improve the antioxidant activity and total phenolic content of S. miltiorrhiza. The main antioxidant constituents were characterized by spectroscopic analysis as salvianolic acids. High-performance liquid chromatography (HPLC) quantification also showed the enhanced content of salvianolic acid B after fermentation. The present study suggests that G. luteus fermentations are effective in the S. miltiorrhiza salvianolic acids’ enrichment process.  相似文献   

13.
An extracellular β-glucosidase produced by Aspergillus terreus was identified, purified, characterized and was tested for the hydrolysis of soybean isoflavone. Matrix-assisted laser desorption/ionization with tandem time-of-flight/time-of-flight mass spectrometry (MALDI-TOF/TOF MS) revealed the protein to be a member of the glycosyl hydrolase family 3 with an apparent molecular mass of about 120 kDa. The purified β-glucosidase showed optimal activity at pH 5.0 and 65 °C and was very stable at 50 °C. Moreover, the enzyme exhibited good stability over pH 3.0–8.0 and possessed high tolerance towards pepsin and trypsin. The kinetic parameters Km (apparent Michaelis-Menten constant) and Vmax (maximal reaction velocity) for p-nitrophenyl-β-d-glucopyranoside (pNPG) were 1.73 mmol/L and 42.37 U/mg, respectively. The Km and Vmax for cellobiose were 4.11 mmol/L and 5.7 U/mg, respectively. The enzyme efficiently converted isoflavone glycosides to aglycones, with a hydrolysis rate of 95.8% for daidzin, 86.7% for genistin, and 72.1% for glycitin. Meanwhile, the productivities were 1.14 mmol/(L·h) for daidzein, 0.72 mmol/(L·h) for genistein, and 0.19 mmol/(L·h) for glycitein. This is the first report on the application of A. terreus β-glucosidase for converting isoflavone glycosides to their aglycones in soybean products.  相似文献   

14.

Objective

To investigate a possible association between common variations of the P2RY12 and the residual clopidogrel on-treatment platelet reactivity after adjusting for the influence of CYP2C19 tested by thromboelastography (TEG).

Methods

One hundred and eighty patients with acute coronary syndrome (ACS) treated with clopidogrel and aspirin were included and platelet function was assessed by TEG. Five selected P2RY12 single nucleotide polymorphisms (SNPs; rs6798347, rs6787801, rs6801273, rs6785930, and rs2046934), which cover the common variations in the P2RY12 gene and its regulatory regions, and three CYP2C19 SNPs (*2,*3,*17) were genotyped and possible haplotypes were analyzed.

Results

The high on-treatment platelet reactivity (HTPR) prevalence defined by a platelet inhibition rate <30% by TEG in adenosine diphosphate (ADP)-channel was 69 (38.33%). Six common haplotypes were inferred from four of the selected P2RY12 SNPs (denoted H0 to H5) according to the linkage disequilibrium R square (except for rs2046934). Haplotype H1 showed a significantly lower incidence of HTPR than the reference haplotype (H0) in the total study population while haplotypes H1 and H2 showed significantly lower incidences of HTPR than H0 in the nonsmoker subgroup after adjusting for CYP2C19 effects and demographic characteristics. rs2046934 (T744C) did not show any significant association with HTPR.

Conclusions

The combination of common P2RY12 variations including regulatory regions rather than rs2046934 (T744C) that related to pharmacodynamics of clopidogrel in patients with ACS was independently associated with residual on-clopidogrel platelet reactivity. This is apart from the established association of the CYP2C19. This association seemed more important in the subgroup defined by smoking.
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15.
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16.
In this paper we will first prove that the nontrivial L p solutions of the vector refinement e-quation exist if and only if the corresponding subdivision scheme with a suitable initial function converges in L p without assumption of the stability of the solutions. Then we obtain a characterization of the convergence of the subdivision scheme in terms of the mask. This gives a complete answer to the existence of L p solutions of the refinement equation and the convergence of the corresponding subdivision schemes.  相似文献   

17.
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18.
Chlamydia psittaci is an important zoonotic pathogen in birds and may be transmitted to humans and result in severe respiratory disease. To assess the prevalence and genotype of C. psittaci in birds in Kunming, Yunnan, China, a total of 136 specimens of psittacine birds involving 8 species were collected from the city’s zoos (n=60) and pet markets (n=76). The frequency of C. psittaci infection was 19.9% (27/136) in the psittacine birds. The prevalence of C. psittaci was higher in pet birds (26.3%; 20/76) than in zoo birds (11.7%; 7/60) (P=0.034). In particular, among Agapornis fischeri, the C. psittaci infection (50%; 10/20) was significantly more frequent in the pet markets than in the zoos (P=0.006). In addition, the highest prevalence of 41.2% (7/17) was found in Ara ararauna. To determine the genotype of C. psittaci, 23 OmpA gene fragments (about 1.4 kb) in 27 positive samples were successfully amplified and sequenced. Phylogenetic analysis showed that all the 23 strains belonged to genotype A. Our results demonstrate the high prevalence of C. psittaci genotype A infection in psittacine birds in Yunnan Province, suggesting a potential threat to human health in this area. Therefore, it is necessary to take effective measures to prevent the spread of C. psittaci among psittacine birds, as well as among employees and customers.  相似文献   

19.
The objective of this study was to describe the fecal microbiota succession of piglets from birth to post-weaning by pyrosequencing. The dominant bacterial phyla were Bacteroidetes, Firmicutes, Proteobacteria, and Fusobacteria, although the composition of the fecal microbiota changed as the piglets grew. Bacteroides, Parabacteroides, Prevotella, Lactobacillus, unclassified Lachnospiraceae, Ruminococcus, Oscillospira, Phascolarctobacterium, and Desulfovibrio were the core genera in the feces of piglets and existed from birth to post-weaning. Bacteroides was the most abundant at birth; however, the proportion of Bacteroides decreased as the piglets aged, while the proportion of Prevotella increased until it became the most abundant genus at the post-weaning stage. Principal coordinate analysis indicated that the microbial communities of piglet fecal samples from birth to post-weaning could be separated into four groups according to the similarity of community composition. These corresponded to time points on day 0 (birth); day 7; days 14, 21, and 28 (pre-weaning); and day 35 (post-weaning). This study suggests that the development of the intestinal microbiota in the piglet is a gradual and sequential process. This methodology establishes a basis for broader studies to investigate the microbiota of the piglet intestinal tract.  相似文献   

20.
As an easy application of the intermediate value theorem, one can show that for any continuous function f: [0, 1] → ? with f (0) = f (1), there are points a, a + 1/2 both in [0, 1] such that f (a) = f (a + 1/2). In this note, we show that this property holds with 1/2 replaced by any number of the form 1/n for a positive integer n. More interestingly, we show that this is false for every number not of the form 1/n.  相似文献   

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