Covalent attachment of chiral alkaloids onto silicon surfaces

H. Wang,H.L. Zhang,Y. Guo,F.Y. Qiao,Q.Y. Sun 한국물리학회 2007 Current Applied Physics Vol.7 No.s1

In this work, we report the covalent attachment of a chiral molecule onto a hydrogen-terminated Si(SiH) surface by using an extre-mely mild approach. Cinchonine, a chiral alkaloid was self-assembled onto a SiH surface via a photochemistry method at room tem-perature. The self-assembled monolayers (SAMs) obtained were characterized by means of ellipsometry, XPS and wettability studies.The lm formation kinetics was monitored by ellipsometry and XPS, which indicated that a full monolayer was formed within 15 h.

Non-fragile H_~ filtering for nonlinear discrete-time delay systems with randomly occurring gain variations

Liu, Y.,Park, J.H.,Guo, B.Z. Instrument Society of America 2016 ISA transactions Vol.63 No.-

In this paper,the problem of H<SUB>~</SUB> filtering for a class of nonlinear discrete-time delay systems is investigated. The time delay is assumed to be belonging to a given interval, and the designed filter includes additive gain variations which are supposed to be random and satisfy the Bernoulli distribution. By the augmented Lyapunov functional approach, a sufficient condition is developed to ensure that the filtering error system is asymptotically mean-square stable with a prescribed H<SUB>~</SUB> performance. In addition, an improved result of H<SUB>~</SUB> filtering for linear system is also derived. The filter parameters are obtained by solving a set of linear matrix inequalities. For nonlinear systems, the applicability of the developed filtering result is confirmed by a longitudinal flight system, and an additional example for linear system is presented to demonstrate the less conservativeness of the proposed design method.

Concomitant nitrates enhance clopidogrel response during dual anti-platelet therapy

Lee, D.H.,Kim, M.H.,Guo, L.Z.,De Jin, C.,Cho, Y.R.,Park, K.,Park, J.S.,Park, T.H.,Serebruany, V. Elsevier/North-Holland Biomedical Press 2016 INTERNATIONAL JOURNAL OF CARDIOLOGY Vol.203 No.-

<P>Background: Despite advances in modern anti-platelet strategies, clopidogrel still remains the cornerstone of dual anti-platelet therapy (DAPT) in patients undergoing percutaneous coronary interventions (PCI). There is some inconclusive evidence that response after clopidogrel may be impacted by concomitant medications, potentially affecting clinical outcomes. Sustained released nitrates (SRN) are commonly used together with clopidogrel in post-PCI setting for mild vasodilatation and nitric oxide-induced platelet inhibition. Methods: We prospectively enrolled 458 patients (64.5 +/- 9.6 years old, and 73.4% males) following PCI undergoing DAPT with clopidogrel and aspirin. Platelet reactivity was assessed by the VerifyNow (TM) P(2)Y12 assay at the maintenance outpatient setting. Results: Concomitant SRN (n = 266) significantly (p = 0.008) enhanced platelet inhibition after DAPT (251.6 +/- 80.9 PRU) when compared (232.1 +/- 73.5 PRU) to the SRN-free (n = 192) patients. Multivariate logistic regression analysis with the cut-off value of 253 PRU for defining heightened platelet reactivity confirmed independent correlation of more potent platelet inhibition during DAPT and use of SRN (Relative risk = 1.675; Odds ratio [1.059-2.648]; p = 0.027). In contrast, statins, calcium-channel blockers, beta blockers, angiotensin receptor blockers, ACE-inhibitors, diuretics, and anti-diabetic agents did not significantly impact platelet inhibition following DAPT. Conclusion: The synergic ability of SRN to enhance response during DAPT may have important clinical implications with regard to better cardiovascular protection, but extra bleeding risks, requiring further confirmation in a large randomized study. (C) 2015 Elsevier Ireland Ltd. All rights reserved.</P>

Environmentally friendly and non-polluting solvent pretreatment of palm samples for polyphenol analysis using choline chloride deep eutectic solvents

Fu, N.,Lv, R.,Guo, Z.,Guo, Y.,You, X.,Tang, B.,Han, D.,Yan, H.,Row, K.H. Elsevier 2017 Journal of chromatography Vol.1492 No.-

<P>In this work, choline chloride (ChCI) deep eutectic solvents (DESs) were evaluated for the pretreatment of palm samples in the analysis of polyphenols, such as protocatechuic acid, catechins, epicatechin, and caffeic acid. During the enrichment step of the pretreatment, eight DESs comprising ChCI with ethylene glycol (EG), glycerol (Gly), xylitol (Xyl), phenol (Ph), formic acid (FA), citric acid (CiA), oxalic acid (OA), or malonic acid (MA), were prepared and applied to the reflux extraction of polyphenols from palm samples. All the DESs exhibited higher polyphenol extraction efficiency than methanol, and the highest extraction efficiency was obtained using ChCI-FA (1:1, mole ratio). For the purification step of the pretreatment, eight ChCI DES-modified adsorbents were prepared by hydrothermal polymerization and packed into solid phase extraction (SPE) cartridges, and ChCI-Urea, ChCI-Gly, ChCI-FA, and water, were used as eluents. The ChCI DES-modified adsorbents were characterized by Fourier transform infrared spectroscopy, thermal gravimetric analysis, scanning electron microscopy, and Brunauer-Emmett-Teller surface analysis, and the polyphenols were analyzed by mass spectrometry and high-performance liquid chromatographultraviolet detection. The highest purification efficiency was obtained using the ChCI-Ph DES-modified adsorbent as the SPE packing material and ChCI-Urea-H2O (1:1:5, mole ratio), ChCI-Gly (1:1, mole ratio), ChCI-FA-H2O (1:1:5, mole ratio), and H2O as the eluents. Compared to conventional purification processes that employ commercial C-18 or C-8 SPE columns with organic solvents as eluents, the ChCI DES-based SPE purification process successfully avoided the use of expensive commercial SPE columns and organic solvents. Furthermore, it isolated a larger amount of the target compounds under the same experimental conditions, and could be applied over five cycles with good reversibility. This work indicates that DESs as green solvents have great potential for the totally green pretreatment of samples during the enrichment and purification processes. (C) 2017 Elsevier B.V. All rights reserved.</P>

Integrating Soil Information System with Agro-environmental Application in Taiwan

Guo, H.Y.,Hseu, Z.Y.,Chen, Z.S.,Tsai, C.C.,Jien, S.H. 한국토양비료학회 2009 한국토양비료학회 학술발표회 초록집 Vol.2009 No.10

Effects of Post-harvest Storage Duration and Variety on Nutrient Digestibility and Energy Content Wheat in Finishing Pigs

Guo, P.P.,Li, P.L.,Li, Z.C.,Stein, H.H.,Liu, L.,Xia, T.,Yang, Y.Y.,Ma, Y.X. Asian Australasian Association of Animal Productio 2015 Animal Bioscience Vol.28 No.10

This study was conducted to investigate the effects of post-harvest storage duration and wheat variety on the digestibility and energy content of new season wheat fed to finishing pigs. Two wheat varieties (Shi and Zhong) were harvested in 2013 and stored in the warehouse of the Fengning Pig Experimental Base at China Agricultural University for 3, 6, 9, or 12 mo. For each storage period, 12 barrows were placed in metabolism crates and allotted to diets containing 1 of the 2 wheat varieties in a randomized complete block design. The experimental diets contained 97.34% wheat and 2.66% of a vitamin and trace mineral premix. With an extension of storage duration from 3 mo to 12 mo, the gross energy (GE) and crude protein (CP) of the wheat decreased by 2.0% and 12.01%, respectively, while the concentration of neutral detergent fiber (NDF), acid detergent fiber (ADF) and starch content increased by 30.26%, 19.08%, and 2.46%, respectively. Total non-starch polysaccharide, total arabinose, total xylose and total mannose contents decreased by 46.27%, 45.80%, 41.71%, and 75.66%, respectively. However, there were no significant differences in the chemical composition between the two wheat varieties with the exception of ADF which was approximately 13.37% lower in Shi. With an extension of storage duration from 3 mo to 12 mo, the digestible energy (DE), metabolizable energy (ME) content and the apparent total tract digestibility of GE, CP, dry matter, organic matter, ether extract, ADF and metabolizability of energy in wheat decreased linearly (p<0.01) by 5.74%, 7.60%, 3.75%, 3.88%, 3.50%, 2.47%, 26.22%, 27.62%, and 3.94%, respectively. But the digestibility of NDF changed quadratically (p<0.01). There was an interaction between wheat variety and storage time for CP digestibility (p<0.05), such that the CP digestibility of variety Zhong was stable during 9 mo of storage, while the CP digestibility of variety Shi decreased (p<0.05). In conclusion, the GE, DE, and ME of wheat was stable during the first 3 to 6 mo of post-harvest storage, and decreased during the following 6 to 12 mo of storage under the conditions of this study.

Numerical simulation of separation process for enhancing fine particle removal in tertiary sedimentation tank mounting adjustable baffle

Guo, H.,Ki, S.J.,Oh, S.,Kim, Y.M.,Wang, S.,Kim, J.H. Pergamon Press 2017 Chemical engineering science Vol.158 No.-

The presence of flow control devices and/or obstacles in the fluid flow such as baffles and spacers complicates the solid-fluid mixing pattern, which remains difficult to describe by classical analytical solutions. In this study, the removal of fine particles in a tertiary sedimentation tank mounting an adjustable baffle was investigated using the computational fluid dynamics code-COMSOL. The solid-fluid motion was solved by consecutively applying the equations of the continuity and momentum using the finite element method. The experiment was conducted by the sedimentation tank with the adjustable baffle inclined at 30<SUP>o</SUP> in a pilot scale plant. It's used as the reference data set for numerical simulations that were run on a 2-dimensional domain by modifying the configuration settings of angles for an adjustable baffle (i.e., 30<SUP>o</SUP>, 45<SUP>o</SUP>, and 60<SUP>o</SUP>) and without one. Results showed that the simulation results matched well with the experimental data for an adjustable baffle at 30<SUP>o</SUP> (NSE=0.97). The sedimentation tank with the adjustable baffle at different angles had a lower overflow rate (in the area of flow rebound) and mixing intensity (in the area of flow curve) than without one, eventually leading to enhanced particle removal efficiency. This tendency became more pronounced as the particle motion stabilized over time. The sedimentation tank mounting the adjustable baffle at 30<SUP>o</SUP> provided the best settling efficiency among the four different flow patterns. However, the conventional index that represents the mixing properties did not correctly address their relative efficiency for fine particle removal. Therefore, a numerical simulation tailored to a given geometry should be conducted to fully elucidate the fluid dynamics in the sedimentation tank with complex devices or obstacles.

Some General Convergence Principles With Applications

H. Y. Zhou,G. L. Gao,G. T. Guo,Y. J. Cho 대한수학회 2003 대한수학회보 Vol.40 No.3

In the present paper, some general convergenceprinciples are established in metric spaces and then thesesprinciples are applied to the convergence of the iterativesequences for approximating fixed points of certain classes ofmappings. By virtue of our principles, most of the latest resultsobtained by several authors can be deduced easily.

Screening lactic acid bacteria from swine origins for multistrain probiotics based on in vitro functional properties

Guo, X.H.,Kim, J.M.,Nam, H.M.,Park, S.Y.,Kim, J.M. Academic Press 2010 Anaerobe Vol.16 No.4

Lactic acid bacteria originated from swine feces and intestines were selected for potential probiotics based on their bile-salt resistance, low pH tolerance, potential adhesion to epithelial cells and especially functional properties, including production of antimicrobial substances, bile-salt hydrolase (BSH) and amylolytic activity. Results showed 7 isolates with antimicrobial activity, 5 with BSH activity and 3 with amylolytic activity were preliminarily selected from 485 lactic acid bacteria based on their highest potential with functional properties in vitro. The 15 isolates were further assayed on the essential characteristics as potential probiotics. All isolates were fully tolerant to 0.3% bile salts and 11 of them were able to resist pH 3 for 3 h without loss of viable cells. The eleven isolates were then evaluated on their adhesion capability. Wide variation in the hydrophobic character and specific adhesion efficiency was observed and three isolates G1-1, G22-2 and G8-5, with respective antimicrobial, BSH and amylolytic activities were finally selected. In addition, the three isolates were compatible in the coexistence assay. Isolate G1-1 was identified as Lactobacillus salivarius by API system and a 16S rRNA gene sequence analysis. Both G8-5 and G22-2 showed the closest homology to Lactobacillus reuteri according to their 16S rRNA gene sequences (99%). From the study, the three Lactobacilli strains were shown to share the functional properties necessary for probiotics use in animal additives. Their compatibility with respective in vitro activities was expected to show enhanced in vivo efficacy after combination for multistrain probiotics use.

Characterization and Mapping of the Bovine FBP1 Gene

Guo, H.,Liu, W-S.,Takasuga, A.,Eyer, K.,Landrito, E.,Xu, Shang-zhong,Gao, X.,Ren, H-Y. Asian Australasian Association of Animal Productio 2007 Animal Bioscience Vol.20 No.9

Fructose-1,6-bisphosphatase (FBP1) is a key regulatory enzyme of gluconeogenesis that catalyzes the hydrolysis of fructose-1,6-bisphosphate to generate fructose-6-phosphate and inorganic phosphate. Deficiency of fructose-1, 6-bisphosphatase is associated with fasting hypoglycemia and metabolic acidosis. The enzyme has been shown to occur in bacteria, fungi, plants and animals. The bovine FBP1 gene was cloned and characterized in this study. The full length (1,241 bp) FBP1 mRNA contained an open reading frame (ORF) encoding a protein of 338 amino acids, a 63 bp 5' untranslated region (UTR) and a 131 bp 3' UTR. The bovine FBP1 gene was 89%, 85%, 82%, 82% and 74% identical to the orthologs of pig, human, mouse, rat and zebra fish at mRNA level, and 97%, 96%, 94%, 93% and 91% identical at the protein level, respectively. This gene was broadly expressed in cattle with the highest level in testis, and the lowest level in heart. An intronic single nucleotide polymorphism (SNP) (A/G) was identified in the $5^{th}$ intron of the bovine FBP1 gene. Genotyping of 133 animals from four beef breeds revealed that the average frequency for allele A (A-base) was 0.7897 (0.7069-0.9107), while 0.2103 (0.0893-0.2931) for allele B (G-base). Our preliminary association study indicated that this SNP is significantly associated with traits of Average Daily Feed Intake (ADFI) and Carcass Length (CL) (p<0.01). In addition, the FBP1 gene was assigned on BTA8 by a hybrid radiation (RH) mapping method.