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Limin Yang

Publications and source records attributed to Limin Yang.

At least 19 recordsLinked to original sources
PubMed2006

Alternative normalization method of atmospheric polycyclic aromatic hydrocarbons pollution level recorded by tree bark.

An alternative normalization method was developed for evaluating atmospheric polycyclic aromatic hydrocarbons (PAHs) pollution level when using tree bark as a passive sampling medium. Perylene (PER), which mainly stems from natural biogenic processes, was proposed as a "natural internal compound" (NIC) of atmospheric PAHs accumulation processes from air into the bark, and a concentration ratio of target PAH to PER (RPAH/PER) was used to minimize the uncertainty in the evaluation of atmospheric PAHs pollution level. Systematic investigation of the effects of intrinsic bark characteristics and extrinsic seasonal meteorological conditions on the partition processes of atmospheric PAHs indicated that RPAH/PER is as an alternative index as compared to bark mass concentration (BMCPAH, ng/g dry bark), lipid mass concentration (LMCPAH, ng/g lipid of bark), and area mass concentration (AMCPAH, ng/m2 surface area of bark) for the evaluation of atmospheric PAHs pollution and that it allows more flexible sampling of tree barks. Clearly, the methodology should be expected to be useful for the objective evaluation of atmospheric pollution levels of other persistent organic pollutants when using tree bark and other passive sampling media if corresponding NICs are found in the future.

Air Pollutants↗
PubMed2006

A study of home deaths in Japan from 1951 to 2002.

BACKGROUND: Several surveys in Japan have indicated that most terminally ill Japanese patients would prefer to die at home or in a homelike setting. However, there is a great disparity between this stated preference and the reality, since most Japanese die in hospital. We report here national changes in home deaths in Japan over the last 5 decades. Using prefecture data, we also examined the factors in the medical service associated with home death in Japan. METHODS: Published data on place of death was obtained from the vital statistics compiled by the Ministry of Health, Labor and Welfare of Japan. We analyzed trends of home deaths from 1951 to 2002, and describe the changes in the proportion of home deaths by region, sex, age, and cause of death. Joinpoint regression analysis was used for trend analysis. Logistic regression analysis was performed to identify secular trends in home deaths, and the impact of age, sex, year of deaths and cause of deaths on home death. We also examined the association between home death and medical service factors by multiple regression analysis, using home death rate by prefectures in 2002 as a dependent variable. RESULTS: A significant decrease in the percentage of patients dying at home was observed in the results of joinpoint regression analysis. Older patients and males were more likely to die at home. Patients who died from cancer were less likely to die at home. The results of multiple regression analysis indicated that home death was related to the number of beds in hospital, ratio of daily occupied beds in general hospital, the number of families in which the elderly were living alone, and dwelling rooms. CONCLUSION: The pattern of the place of death has not only been determined by social and demographic characteristics of the decedent, but also associated with the medical service in the community.

Journal Article↗
PubMed2006

[Modules biomass structure and growth pattern of Acanthopanax senticosus population in different habitats].

In this paper, a quantitative analysis was conducted on the functional modules' biomass structure and the relationships between biomass allocation and age of Acanthopanax senticosus population in three different habitats of coniferous and broad--leaved mixed forest, Quercus mongolica forest, and secondary miscellaneous forest. The results showed that the individual growth and modules' biomass accumulation of A. senticosus population were closely related to habitat conditions. The mean values of all functional modules' biomass under different ecological environments exhibited the same regularity, i. e. , stem modules > rhizome modules > leaf modules, and there were some similarities in the whole population of A. senticosus. The individual and each module's biomass of the population differed with the canopy density of forests, being larger in Q. mongolica forest with 40% of canopy density than in coniferous and broad-leaved mixed forest and secondary miscellaneous forest. The variations of ramet biomass allocation under different habit conditions indicated the important strategies in growth regulation and biomass allocation, i. e., more biomass was allocated to the leaves preferentially on small ramets, especially in the secondary miscellaneous forest with biggest canopy density, to ensure the full material product. There was the same regulation of heterogeneous speed growth in the relative weight increase of the leaves, stems and ramets of the population under the three habitat conditions.

Biomass↗
PubMed2005

Crystal structures and spectroscopic characterization of galactitol complexes of trivalent lanthanide and divalent alkaline earth chlorides.

Crystal structures and FT-IR spectra of metal ion-galactitol (C6H14O6, the ligand here abbreviated as L) complexes: 2LaCl3*C6H14O6*10H2O and SrCl2*C6H14O6 complexes are reported. Crystal data of lanthanide chlorides (La3+, Nd3+, Sm3+, Eu3+, Tb3+)-galactitol complexes and alkaline earth chlorides (Ca2+, Sr2+)-galactitol complexes published earlier are summarized. Unlike other lanthanide ion-galactitol complexes (2MCl3*C6H14O6*14H2O), lanthanum ions give rise to two different structures: LaCl3*C6H14O6*6H2O (LaL1) and 2LaCl3*C6H14O6*10H2O (LaL2). Sr2+-galactitol complexes also crystallized with two structures: SrCl2*C6H14O6*4H2O (SrL1) and SrCl2*C6H14O6 (SrL2). These metal ions thus give different coordination structures with galactitol. The crystal structures and FT-IR spectra of lanthanide ion and alkaline earth ion-galactitol complexes were integrated to interpret the coordination modes of different metal ions. Similar IR spectra demonstrate the same coordination modes of the complexes.

Crystallization↗
PubMed2005

Interactions between metal ions and carbohydrates. The coordination behavior of neutral erythritol to lanthanum and erbium ions.

Lanthanide ions and erythritol form metal-alditol complexes with various structures. Lanthanum nitrate and erbium chloride coordinate to erythritol to give new coordination structures. The lanthanum nitrate-erythritol complex (LaEN), 2La(NO3)3.C4H10O(4).8H2O, La3+ exhibits the coordination number of 11 (namely 11 polar atoms bound to one lanthanum) and is 11-coordinated to two hydroxyl groups from one erythritol molecule, six oxygen atoms from three nitrate ions and three water molecules. One erythritol molecule is coordinated to two La3+ ions and links the two metal ions together. The ratio of M:L is 2:1. The erbium chloride-erythritol complex (ErE), ErCl2.C4H9O(4).2C2H5OH was obtained from ErCl3 and erythritol in aqueous ethanol solution and the structure shows that deprotonation reaction occurs in the reaction process. The Er3+ cation is 8-coordinated with three hydroxyl groups of one erythritol molecule, two hydroxyl groups from another erythritol molecule, two ethanol molecules, and one chloride ion. Erythritol provides its three hydroxyl groups to one erbium cation and two hydroxyl groups to another erbium cation, that is, one hydroxyl group is coordinated to two metal ions and therefore loses its hydrogen atom and becomes a oxygen bridge. Another chloride ion is hydrogen bonded in the structure. The results indicate the complexity of metal-sugar coordination.

Crystallization↗
PubMed2005

New, rapid fluorescence stain method for histologic sections using lanthanide complexes.

A new stain method for histologic sections different from traditional hematoxylin and eosin (H&E) methodology used two newly developed stain reagents from the lanthanide series, the antibiotic ofloxacin chelate of europium(III) and the ciprofloxacin hydrochloride chelate of terbium(III), exhibiting excellent fluorescence. These complexes are unique due to their nontoxicity, attractive fluorescent properties, rapid staining, and high water solubility. In this article, we focus on the interactions between biomolecules and synthesized lanthanide complexes and on the staining effect applied for tissue staining.

Ciprofloxacin↗
PubMed2005

FT-IR spectroscopic study on the variations of molecular structures of some carboxyl acids induced by free electron laser.

Free electron laser has been developed as tunable lasers over a wide range of wavelengths. Devices irradiating in the region of 6-16 microm (1666-625 cm-1) are operable in the Beijing free electron lasers facilities (BFEL). For understanding the interactions between FEL and biological tissues, in this study wavelength-selective infrared-induced structure changes of substances under irradiation by FEL were measured using FT-IR spectroscopy. The carboxyl acids and carboxylates samples investigated include salicylic acid, sulfosalicylic acid, cholic acid, deoxycholic acid, sodium cholate and sodium deoxycholate. The changes of the FT-IR spectra of the molecules prove that the spectral variations of the samples induced by FEL are closely related to their hydrogen bond networks.

Carboxylic Acids↗
PubMed2005

Interactions between metal ions and carbohydrates. The coordination behavior of neutral erythritol to neodymium ion.

A single crystal of a coordinated complex of neutral erythritol (C4H10O4,E) with a neodymium ion, NdE(II), was synthesized and studied using FT-IR and X-ray diffraction analysis. In NdE(II) (NdCl3.2.5C4H10O4.C2H5OH) the Nd3+ coordinates with one chloride ion and eight OH groups from three erythritol molecules. There are two neodymium centers linked by one erythritol molecule with same coordination structure in the molecule. Two erythritol molecules provide 1,3,4-hydroxyl groups to coordinate with a neodymium ion; another erythritol molecule coordinates to two Nd ions via its 1,2-hydroxyl groups and 3,4-hydroxyl groups, respectively. The OH groups of erythritol act as ligand to coordinate to neodymium ions, and OH groups of erythritol form hydrogen bond networks that link chain and layer together to build three-dimensional structures. The ratio of metal to ligand is 1:2.5. The structure of NdE(II) is more complicated than the previously reported NdE(I), which is NdCl3.C4H10O4.6H2O; in NdE(I), Nd3+ is coordinated to four hydroxyl groups from two erythritol molecules, four water molecules and one chloride ion. The results indicate the complexity of metal-sugar interaction.

Journal Article↗
PubMed2004

Historical records of airborne polycyclic aromatic hydrocarbons by analyzing dated corks of the bark pocket in a Longpetiole Beech tree.

Historical monitoring of airborne polycyclic aromatic hydrocarbons (PAHs) pollution levels was novelly demonstrated by analyzing the dated corks of a bark pocket formed from 1873 to 2003 in a Longpetiole Beech (Fagus longipetiolata) tree trunk sampled from southeastern China. The fundamental studies indicated that the PAHs of log K(oa) < 8.5 are primarily accumulated through interactions with lipid substances in cork and log K(oa) dependent, while the PAHs of log K(oa) > 8.5 existing as particle-phase dependent on log Vp are accumulated through stochastic entrapment by the lenticels on the surface of the cork. The translocation of PAHs by xylem flow and phloem stream as well as radial diffusion from the cork to the inner tissues was not significant, and the cork is most effective for accumulating airborne PAHs. The total concentrations of 16 EPA PAHs (sumPAHs) in the dated corks progressively increased from 43.5 ng/g recorded in the earliest available cork in 1873-1875 to the maximum 345.7 ng/g in 1956-1961, and then gradually decreased to 267.0 ng/g in 2003, while the concentration of perylene (PER) was slightly fluctuating at 0.178 +/- 0.033 ng/g. Moreover, the concentration ratio of sumPAHs to PER increased from 193 to 2431 from 1873 to 2003, indicating a progressive increase in PAH pollution in southeastern China.

Air Pollutants↗
PubMed2004

Complexation of trivalent lanthanide cations by erythritol in the solid state. The crystal structure and FT-IR study of 2EuCl3.2C4H10O4.7H2O.

Erythritol was chosen to study the interactions between metal ions and carbohydrates. FTIR spectroscopy results indicate that a EuCl3-erythritol complex different from a previously reported one was obtained. The crystal structure of EuCl3-erythritol complex, 2EuCl3.2C4H10O4.7H2O, Mr=443.49, a=13.846(3) A , b=7.4983(15) A, c=14.140(3) A, beta=116.39(3) degrees, V=1315.1(5) A(3), Z=4, mu=5.394 mm(-1) and R=0.0395 for 2965 observed reflections and 143 parameters, was determined. Characteristic of this complex is the presence of binuclear europium ions with different coordination structures. One Eu3+ ion is nine-coordinated, with five Eu-O bonds from water molecules, and four from hydroxyl groups of two erythritol molecules and another Eu3+ is eight-coordinated with two water molecules, two chloride ions, and four hydroxyl groups from two erythritol molecules. Erythritol provides two hydroxyl groups to one lanthanide ion and the other two to another rare earth ion. The OH, CO stretching and other vibrations are shifted in the IR spectra of the complexes and the results are consistent with the crystal structure.

Cations↗
PubMed2004

L-serine-mediated release of apolipoprotein E and lipids from microglial cells.

Apolipoprotein E (ApoE), one of the genetic risk factors for Alzheimer's disease, is considered to have a critical role in transporting lipids in the brain. In the present study, we investigated ApoE release in primary rat microglial cultures. Microglial cells released ApoE in response to L-Ser in culture medium, and ApoE-immunoreactivity was detected in granules in the cell periphery and in perinuclear structures. Immunocytochemical studies, immunoblotting, and reverse transcription-polymerase chain reaction (RT-PCR) results all supported the notion that microglial cells are the potential source of ApoE in the brain. L-Ser enhanced ApoE release in a concentration-dependent manner without upregulating ApoE mRNA expression. Astrocytes presumably enhanced production and release of ApoE by microglial cells through secretion of L-Ser. As revealed by gel chromatography, ApoE was secreted as a component of lipoproteins, and L-Ser enhanced release of cholesterol and triglycerides together with ApoE. Activation of microglial cells by lipopolysaccharides and serum resulted in an overall decrease of the ApoE release. These findings suggest that microglial cells are a significant source of lipoproteins containing ApoE in the brain under physiological conditions, and that L-Ser is an important mediator of the neuron-astrocyte-microglia network in the brain.

Animals↗
PubMed2004

Interactions between metal ions and carbohydrates: the coordination behavior of neutral erythritol to transition metal ions.

The single crystals of coordinated complexes of neutral erythritol (C4H10O4) with various transition metal ions were synthesized and studied using FT-IR and single crystal X-ray diffraction analysis. Two CuCl2-erythritol complexes (denoted as CuE(I) and CuE(II)) were obtained. In CuE(I), Cu2+ coordinates with two chloride ions and four OH groups from two erythritol molecules. Two copper centers are linked by one erythritol molecule to form a zigzag chain. For CuE(II), each Cu2+ coordinates with two OH groups from an erythritol molecule and two chloride ions. The crystal of CuE(II) contains complexed and free erythritol, the dimers of [Cu2Cl4(C4H10O4)] further form a [Cu2Cl4(C4H10O4)]infinity chain via secondary Cu...Cl bonds, both the dimer unit of [Cu2Cl4.(C4H10O4)] and non-coordinated C4H10O4 unit exist side by side in the crystal. MnCl2-erythritol complex whose structure is similar to CuE(I) is also acquired. The OH groups of erythritol act as ligand to coordinate to metal ions on one hand, one the other hand, OH groups form hydrogen bonds network that link chain and layer together to build three-dimensional structures.

Carbohydrates↗
PubMed2004

Interactions between metal ions and carbohydrates: the coordination behavior of neutral erythritol to zinc and europium nitrate.

The single crystals of coordinated complexes of neutral erythritol (C4H10O4) with zinc nitrate and europium nitrate were synthesized and studied using FT-IR and single crystal X-ray diffraction analysis. In the structure of Zn(NO3)2.C4H10O4, ZnEN (E denotes erythritol, N represents nitrate), Zn2+ is coordinated to four hydroxyl groups from two erythritol molecules and two oxygen atoms from two nitrates. Two Zn2+ are connected by one erythritol molecule to form Zn(C4H10O4)(NO3)2 chain, and layers formed by above chain pile to produce 3D structures. In the structure of Eu(NO3)3.C4H10O4.C2H5OH, EuEN, Eu3+ is 10-coordinated by six oxygen atoms from three nitrate ions, three hydroxyl groups from one erythritol molecule and one hydroxyl group from ethanol. In the above erythritol complexes, two hydroxyl groups of erythritol coordinate to one metal ion and the other two to another metal ion or erythritol acts as three-hydroxyl groups donor. The OH groups of erythritol act as ligand to coordinate to metal ions on one hand, one the other hand, OH groups form hydrogen bonds network to build three-dimensional structures.

Journal Article↗
PubMed2004

The interaction between amino acids and metal ions (I). The FT-IR spectroscopic study of the binding between D,L-homocysteic acid and alkali metal ions.

D,L-Homocysteic acid (DLH), an amino acid in the mammalian central nervous system, can excite the cerebral activities and has been proposed as an agonist of endogenous glutamate receptor. It contains -NH(3)(+), -COOH and -SO(3)(-) groups, therefore, the interactions between DLH and metal ions may be expected. In the present investigation, the complexes of DLH with NH4(+), Li+, Na+ and K+ at different pH conditions were synthesized and characterized by Fourier transform infrared (FT-IR) spectroscopy. It was concluded that the structures of the complexes prepared at pH 2.6 and 4.0 are similar to each other and the C=O groups are mono-dentate coordination for these complexes. However, the structures of the complexes synthesized at pH 13.0 change considerably from the complexes at pH 2.6 and 4.0, which show that dissociation has occurred in aqueous solution. The four cations coordinate to DLH, which result in the rearrangement of the hydrogen bond network and the skeletal structure change of the ligand.

Homocysteine↗
PubMed2003

Interactions between metal ions and carbohydrates. Coordination behavior of neutral erythritol to Ca(II) and lanthanide ions.

The study of the sugar-metal ion interactions remains one of the main objectives of carbohydrate coordination chemistry because the interactions between metal ions and carbohydrates are involved in many biochemical processes. This paper presents a comparison of coordination structures of erythritol with alkaline-earth-metal and lanthanide chloride and nitrate in the solid state using FT-IR and X-ray diffraction. Neutral, nondeprotonated erythritol (E) reacts with CaCl(2) to give three CaCl(2)(-)erythritol (CaE(I), CaE(II), CaE(III)) complexes, showing that three of the five general features of calcium-carbohydrate complexes deduced in the reference encounter contrary examples. Different coordination structures have been observed for calcium and lanthanide chloride and nitrates. The coordination of carbohydrates to metal ions is complicated, and erythritol, chloride ions, nitrates, water molecules, and ethanol (crystallization medium and reaction solvents) have the chance to coordinate to metal ions. IR spectral results show that different lanthanide ions, from LaCl(3) to TbCl(3), have similar coordination structures with erythritol. The results show that erythritol can act as two bidentate neutral ligands (CaE(I), CaE(II), CaE(III), CaEN, PrE, NdE) or as a three-hydroxyl donor (NdEN). The IR results are consistent with the crystal structures.

Calcium↗
PubMed2003

Chromatographic behavior of cadmium in an ion-pair reversed-phase micro HPLC system and its application to the determination of bio-available cadmium in soil samples.

A novel reversed phase ion-pair micro HPLC system with on-line fluorescence detection has been developed systematically and studied for the determination of cadmium in its bio-available fractions of soil samples. In this system, a micro ODS column of 1.0 mm i.d.x150 mm length and a mobile phase containing 6 mmol L(-1) 8-hydroxyquinoline 5-sulphonic acid (HQS), 3 mmol L(-1) cetyltrimethylammonium bromide (CTMABr), 10 mmol L(-1) acetic acid-acetate buffer (pH 5.1) as well as 50% acetonitrile at 50 microL min(-1) flow rate were employed to determine cadmium with a 2 microL flow cell through its fluorescence at 518 nm under 338 nm excitation. Furthermore, the composition of Cd-HQS chelate formed on the column was confirmed to be [Cd(HQS)(2)](2-) through a log-log plot method, and then combined with the ion-pair reagent by the electrostatic force under the chromatographic condition proposed. With such a method, the detection limit of cadmium was 8.48 ng mL(-1) (3sigma) with 1 microL sample injection, and the linear range for the determination of cadmium was 30-800 ng mL(-1) (R(2)=0.992). This method has been successfully applied to determination of cadmium in its bio-available fractions of BCR-483 and soil samples without interference from other coexistent metal ions. The RSD (n=6) was less than 7.3%. The results were in agreement with the indicative value for BCR-483 and those for the soil samples obtained by ICP-MS with a pretreatment of bis(1,1,3,3-tetramethylbutyl) phosphinic acid extraction.

Biological Availability↗
PubMed2003

Sugar interaction with metal ion: crystal structure and spectroscopic study of SrCl2.galactitol.4H2O.

The crystal structure of SrCl(2).galactitol.4H(2)O has been determined. It belongs to monoclinic system, C2/c space group with unit cell dimensions: a=13.9849(3), b=14.1601(5), c=8.3026(3) A, beta=104.621(2) degrees, V=1590.9(9) A(3) and Z=4. Each Sr(2+) ion in the unit cell binds to two molecules of galactitol through O2 and O3 in one alditol and O2' and O3' in the other, as well as to four water molecules. Sr-O distances in SrCl(2).galactitol.4H(2)O complex range from 2.5420 to 2.6359 A. FT-IR, Raman and far-IR spectra of SrCl(2).galactitol.4H(2)O all show that SrCl(2) coordinates with galactitol through OH groups of the sugar molecule to form the new complex.

Carbohydrates↗