Carboxylic acid functionalized imidazolium-based ionic liquids: efficient catalysts for cycloaddition of CO2 and epoxides

Han, Lina,Choi, Soo-Jin,Park, Moon-Seok,Lee, Seon-Myong,Kim, Yu-Jin,Kim, Moon-Il,Liu, Binyuan,Park, Dae-Won Springer-Verlag 2012 Reaction kinetics, mechanisms and catalysis Vol.106 No.1

Weighted projective lines with weight permutation

Lina Han,Xintian Wang 대한수학회 2021 대한수학회지 Vol.58 No.1

Let $\mathbb X$ be a weighted projective line defined over the algebraic closure $k=\overline{\mathbb F}_q$ of the finite field $\bbf_q$ and $\sigma$ be a weight permutation of $\mathbb X$. By folding the category coh-$\mathbb{X}$ of coherent sheaves on $\mathbb X$ in terms of the Frobenius twist functor induced by $\sigma$, we obtain an $\bbf_q$-category, denoted by coh-$(\mathbb{X},\sigma;q)$. We then prove that $\coh(\mathbb{X},\sigma;q)$ is derived equivalent to the valued canonical algebra associated with $(\bbX,\sigma)$.

Silica grafted imidazolium-based ionic liquids: efficient heterogeneous catalysts for chemical fixation of CO₂ to a cyclic carbonate

Han, Lina,Park, Sang-Wook,Park, Dae-Won The Royal Society of Chemistry 2009 ENERGY AND ENVIRONMENTAL SCIENCE Vol.2 No.12

<p>Imidazolium-based ionic liquids with varied alkyl chain lengths bearing different anions (Cl<SUP>−</SUP>, Br<SUP>−</SUP> and I<SUP>−</SUP>) were synthesized and immobilized onto the commercial silica surface (<B>IMIS</B>). These heterogeneous catalysts exhibited high catalytic activities and selectivities in the cycloaddition of carbon dioxide to allyl glycidyl ether (AGE). The immobilized ionic liquids with longer alkyl chain length and more nucleophilic anion showed higher activity. In particular, compared with pristine <B>IMIS</B>, zinc halide-combined <B>IMIS</B> (<B>IMIS-Zn</B>) with Cl<SUP>−</SUP> exhibited an increased activity, while the <B>IMIS-Zn</B> with Br<SUP>−</SUP> and I<SUP>−</SUP> showed lower activity than <B>IMIS</B> itself. In addition, the textures of silica supports (surface area and average pore size) have a great impact on the catalytic activity owing to the substance-confined diffusion effects. The recycling experiments showed that the resulting heterogeneous catalysts exhibited good reusability.</p> <P>Graphic Abstract</P><P>Imidazolium-based ionic liquids grafted on commercial silica (<B>IMIS</B>) were synthesized and used as heterogeneous catalysts for cycloaddition of CO<SUB>2</SUB> to allyl glycidyl ether. <img src='http://pubs.rsc.org/ej/EE/2009/b910763k/b910763k-ga.gif'> </P>

Invertebrate water extracts as biocompatible reducing agents for the green synthesis of gold and silver nanoparticles.

Han, Lina,Kim, Yeong Shik,Cho, Seonho,Park, Youmie Natural Product Communications 2013 Natural product communications Vol.8 No.8

<P>We report the use of water extracts of two invertebrates, snail body and earthworm, as biocompatible reducing agents for the green synthesis of gold and silver nanoparticles. The reaction conditions were optimized by varying the extract concentration, gold ion or silver ion concentration, reaction time, and reaction temperature. The gold and silver nanoparticles exhibited their characteristic surface plasmon resonance bands. Mostly spherical and amorphous shapes of the nanoparticles were synthesized. The average diameters of the gold and silver nanoparticles were 4.56 +/- 1.81 nm and 11.12 +/- 5.25 nm, respectively, when the extract of snail body was used as the reducing agent. The earthworm extracts produced gold and silver nanoparticles with average diameters of 6.70 +/- 2.69 nm and 12.19 +/- 4.28 nm, respectively. This report suggests that the invertebrate natural products have potential as biocompatible reducing agents for the green synthesis of metallic nanoparticles. This utility would open up novel applications of invertebrate natural products as nanocomposites and in nanomedicine.</P>

Residual Analysis of Insecticides (Lambda-cyhalothrin, Lufenuron, Thiamethoxam and Clothianidin) in Pomegranate Using GC-μECD or HPLC-UVD

( Lina Hem ),( Jong Hyouk Park ),( Jae Han Shim ) 한국환경농학회 2010 한국환경농학회지 Vol.29 No.3

In this study, the residual levels of four insecticidal compounds (lambda-cyhalothrin, lufenuron, thiamethoxam, and clothianidin) were monitored in the pomegranate, in order to assess the risk to consumers posed by the presence of such residues. The insecticides were applied at the recommended dose rates onto pomegranate trees. The samples were then collected at harvesting time after several treatments (two, three, and four treatments). After sample preparation progressed through the clean-up procedure, lufenuron, thiamethoxam, and clothianidin residues were analyzed via a HPCL-UVD, and the lambda-cyhalothrin residue was analyzed via a GC-μECD. The versatility of this method was evidenced by its excellent linearity (>0.9998 to 1) at broad concentration ranges. The mean recoveries evaluated from the untreated sample spiked with two different fortification levels ranged from 72.45 to 113.90%, and the repeatability (as a relative standard deviation) resulted from triplicate recovery tests was in a range from 0.80 to 11.75%. The residues of all insecticides determined from treated pomegranate samples and their LOD levels (lunfenuron, 0.01; lambda-cyhalothrin, 0.005; thiamethoxam, 0.01; clothianidin, 0.02 mg/kg) were much lower than their MRLs (0.5 mg/kg).

Motor Function in the Late Phase After Stroke: Stroke Survivors’ Perspective

Lina Bunketorp-Käll,Marcela Pekna,Milos Pekny,Hans Samuelsson,Christian Blomstrand,Michael Nilsson 대한재활의학회 2020 Annals of Rehabilitation Medicine Vol.44 No.5

Objective To examine the association between observer-assessed functional status and perceived recovery in the late phase after stroke. The study also aimed to determine whether observer-assessed functional improvements as a result of horse-riding therapy (H-RT) are related to enhanced perception of stroke recovery. Methods This is a descriptive correlational study using data derived from a three-armed randomized controlled trial in which 123 individuals were enrolled, among whom 43 received H-RT for 12 weeks. The measures included the Modified Motor Assessment Scale, Berg Balance Scale, Timed Up and Go, timed 10-m walk, and perceived recovery from stroke indicated by item #9 in the Stroke Impact Scale (version 2.0). Spearman rank order correlation (rs) was used in the analyses. Results There were moderate to strong positive or negative correlations between all four observer-assessed motor variables and participants’ ratings of perceived late-phase stroke recovery at trial entrance, ranging from rs=-0.49 to rs=0.54 (p<0.001). The results of the correlational analyses of variable changes showed that, after the end of the H-RT intervention, both self-selected and fast gait speed improvement were significantly correlated with increments in self-rated stroke recovery (rs=-0.41, p=0.01 and rs=-0.38, p=0.02, respectively). Conclusion This study provided data supporting the association between individual ratings of self-perceived recovery after stroke and observer-assessed individual motor function. The results further demonstrate that enhancement in perceived stroke recovery after completing the intervention was associated with objectively measured gains in both self-selected and fast gait speed.

Study on Dissipation Pattern of Fenitrothion, Folpet, Myclobutanil, Pyridaben, and Tolyfluanid Pesticide Residues in Pepper Grown Under Greenhouse Condition

Lina Hem,Sathya Khay,Sreiny Taing,Jeong-Heui Choi,Jae-Han Shim 한국농약과학회 2008 한국농약과학회 학술발표대회 논문집 Vol.- No.-

Determination of Cyhalofop-butyl and its Metabolite in Water and Soil by Liquid Chromatography

Lina Hem(헴리나),Jeong-Heui Choi(최정희),Xue Liu(유학),Sathya Khay(카이 사티아),Jae-Han Shim(심재한) 한국농약과학회 2008 농약과학회지 Vol.12 No.4

In this study, a simple, effective, and sensitive method has been developed for the quantitative residue analysis of cyhalofop-butyl and its metabolite cyhalofop acid in water and soil when kept under laboratory conditions. The content of cyholofop-butyl and cyhalofop acid in water and soil was analyzed by first purifying the compounds through liquid-liquid extraction and partitioning followed by Silica gel (adsorption) chromatography. Upon the completion of the purification step the residual levels were monitored through high-performance liquid chromatography (HPLC) using a UV absorbance detector. The recoveries of cyhalofop-butyl from three replicates spiked at two different concentrations ranged from 82.5 to 100.0% and from 66.7 to 97.9% in water and soil, respectively. The limit of detection and minimum detection level of cyhalofop-butyl in water and soil was 0.02 ppm and lOng, respectively, The recoveries of cyhalofop acid ranged from 80.7 to 104.8% in water and from 76.9 to 98.1 % in soil. The limit of detection of cyhalofop acid was 0.005 ppm in water and 0.01 ppm in soil, while the minimum detection level was 2 ng both in water and soil. The half-live of cyhalofop-butyl was 4.14 and 6.6 days in water and soil, respectively. The method was successfully applied to evaluate cyhalofop-butyl residues in water and soil applied a.i. 30% emulsion, oil in water (EW) product.

Insulin Resistance Is an Important Risk Factor for Cognitive Impairment in Elderly Patients with Primary Hypertension

Lina Ma,Yun Li,Ming Feng,Yuying Qian,Wei Yang,Jia Liu,Rui Han,Hong Zhu 연세대학교의과대학 2015 Yonsei medical journal Vol.56 No.1

Purpose: Insulin resistance plays a role in the development of dementia and hypertension. We investigated a possible relationship between cognitive impairment and insulin resistance in elderly Chinese patients with primary hypertension. Materialsand Methods: One hundred and thirty-two hypertensive elderly patients (>60 years) were enrolled in this study, and assigned into either the cognitive impairmentgroup (n=61) or the normal cognitive group (n=71). Gender, age, education,body mass index (BMI), waist hip ratio (WHR), total cholesterol (TC), triglyceride(TG), C-reactive protein (CRP), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), creatinine (Cr), fasting plasma glucose (FPG), fasting insulin (FINS), homeostasis model of assessment for insulin resistance index (HOMA-IR), systolic blood pressure, diastolic blood pressure, smoking history, atherosclerosis and the proportion of uncontrolled hypertensionwere compared between the two groups. Multi-factorial logistic regressionanalysis was performed. Results: No significant differences were found in gender, age, TC, CRP, HDL-C, LDL-C, Cr, BP, smoking history, atherosclerosis and the proportion of uncontrolled hypertension between the two groups. The cognitiveimpairment group had lower education levels, and higher BMI, WHR, TG, FPG, FINS, and HOMA-IR levels than the control group. Logistic regression analysis revealed the levels of education, BMI, WHR, and HOMA-IR as independentfactors that predict cognitive impairment in patients. Conclusion: Our study demonstrates that poor education and increased BMI, WHR, and HOMA-IR are independent risk factors for cognitive impairment in elderly patients with hypertension. Insulin resistance plays an important role in the development of cognitive impairment in primary elderly hypertensive patients.

Determination of Trichlorfon Pesticide Residues in Milk via Gas Chromatography with µ-Electron Capture Detection and GC-MS

Lina Hem,Sathya Khay,Jeong-Heui Choi,E.D. Morgan,A.M. Abd El-Aty,Jae-Han Shim 한국독성학회 2010 Toxicological Research Vol.26 No.2

The pesticide trichlorfon is readily degraded under experimental conditions to dichlorvos. A method has therefore been developed by which residues of trichlorfon in milk are determined as dichlorvos, using gas chromatography with μ-electron capture detection. The identification of dichlorvos was confirmed by mass spectrometry. Milk was extracted with acetonitrile followed by centrifugation, freezing lipid filtration, and partitioning into dichloromethane. The residue after partitioning of dichloromethane was dissolved in ethyl acetate for gas chromatography. Recovery concentration was determined at 0.5, 1.0, and 2.0 of times the maximum permitted residue limits (MRLs) for trichlorfon in milk. The average recoveries (n = 6) ranged from 92.4 to 103.6%. The repeatability of the measurements was expressed as relative standard deviations (RSDs) ranging from 3.6%, to 6.7%. Limit of detection (LOD) and limit of quantification (LOQ) were 3.7 and 11.1 ㎍/l, respectively. The accuracy and precision (expressed as RSD) were estimated at concentrations from 25 to 250 ㎍/l. The intra- and inter-day accuracy (n = 6) ranged from 89.2% to 91% and 91.3% to 96.3%, respectively. The intra- and inter-day precisions were lower than 8%. The developed method was applied to determine trichlorfon in real samples collected from the seven major cities in the Republic of Korea. No residual trichlorfon was detected in any samples.