447 research outputs found
Metali u medu iz provincije Henan, Kina: sustavna analiza metodom ICP-AES
In this study, the method for determining ten elements (including K, Na, Ca, Mg, Fe, Mn, Cu, Zn, Pb, and Cd) was designed. With this method, we evaluated 15 honey samples, including three kinds of honey collected from 11 different geographic sites in Henan province of China, with inductively coupled plasma atomic emission spectrometry (ICP-AES). The obtained detecting data were analysed with principal component analysis, correlation analysis, and cluster analysis techniques. The results showed that the recovery is in the range of 93.0â107.0 %, and the relative standard deviations (RSDs) were all below 5.89 %, which indicates that the current analytical method is dependable for the detection of metallic elements in honey.
This work is licensed under a Creative Commons Attribution 4.0 International License.U ovom istraĹživanju osmiĹĄljena je metoda odreÄivanja deset elemenata (K, Na, Ca, Mg, Fe, Mn, Cu, Zn, Pb i Cd). Tom metodom evaluirano je 15 uzoraka meda, ukljuÄujuÄi tri vrste meda prikupljenih s 11 lokaliteta u provinciji Henan, Kina, atomskom emisijskom spektrometrijom s induktivno spregnutom plazmom (ICP-AES). Dobiveni podatci prouÄeni su analizom glavnih komponenti, korelacijskom analizom i tehnikama klasterskih analiza. Rezultati su pokazali da se oporaba kreÄe u rasponu od 93,0 do 107,0 %, a relativne standardne devijacije (RSD) bile su ispod 5,89 %, ĹĄto ukazuje da je trenutaÄna analitiÄka metoda pouzdana za otkrivanje metala u medu.
Ovo djelo je dano na koriĹĄtenje pod licencom Creative Commons Imenovanje 4.0 meÄunarodna
A coordination polymer of CdII with benzene-1,3-dicarboxylÂate and 1,4-bisÂ[1-(2-pyridylmethÂyl)benzimidazol-2-yl]butane
The title CdII coordination polymer, catena-poly[[{1,4-bisÂ[1-(2-pyridylmethÂyl)benzimidazol-2-yl]butane}cadmium(II)]-Îź-benzene-1,3-dicarboxylÂato], [Cd(C8H4O4)(C30H28N6)]n, was obtained by reaction of CdCO3, benzene-1,3-dicarboxylic acid (H2btc) and 1,4-bisÂ[1-(2-pyridylmethÂyl)benzimidazol-2-yl]butane (L). The CdII cation is six-coordinated by an N2O4-donor set. L acts as a bidentate ligand and btc anions link CdII centers into a chain propagating parallel to [010]
Preliminary Trial to Establish Artificial Grassland in Tibet, China
Tibet Autonomous Region with an average altitude of more than 4,000 m above sea level, altogether cover an area of 1.22 million km2, equivalent to one-eight of the total area of China. High mountains along with forests and rivers in Tibet consist of an important ecological barrier for protecting parts of inland ecosystems. Tibet is also one of the five major pastoral areas in China. The grassland in Tibet covers 0.83 million km2, but the grass is sparse and low, and with low yield in this area. There are nearly 2.8 million people in this region, while the area of arable land is less than 2.533 thousand km2. Nearly 40.5 million tons of hay are needed for about 45 million sheep units in Tibet (Yu et al., 2010), while the actual amount is less than 20 million tons (including 15 million tons per year from natural grassland, and 2ď˝3 million tons per year from the straw of naked barley). It exacerbating the degradation of natural grassland for the contradiction between livestock and grass. Research shows that the most effective measure to maintain local economic growth, coordinated development of ecological security and curb the further degradation of the grassland in Tibet is by planting high yielding and high quality forage crops, changing the traditional way of free grazing and implementing captive feeding gradually
Cloning and expression profiling of the VLDLR gene associated with egg performance in duck (Anas platyrhynchos)
<p>Abstract</p> <p>Background</p> <p>The very low density lipoprotein receptor gene (<it>VLDLR</it>), a member of the low density lipoprotein receptor (<it>LDLR</it>) gene family, plays a crucial role in the synthesis of yolk protein precursors in oviparous species. Differential splicing of this gene has been reported in human, rabbit and rat. In chicken, studies showed that the VLDLR protein on the oocyte surface mediates the uptake of yolk protein precursors into growing oocytes. However, information on the <it>VLDLR </it>gene in duck is still scarce.</p> <p>Methods</p> <p>Full-length duck <it>VLDLR </it>cDNA was obtained by comparative cloning and rapid amplification of cDNA ends (RACE). Tissue expression patterns were analysed by semi-quantitative reverse-transcription polymerase chain reaction (RT-PCR). Association between the different genotypes and egg performance traits was investigated with the general linear model (GLM) procedure of the SAS<sup>ÂŽ </sup>software package.</p> <p>Results</p> <p>In duck, two <it>VLDLR </it>transcripts were identified, one transcript (variant-a) containing an O-linked sugar domain and the other (variant-b) not containing this sugar domain. These transcripts share ~70 to 90% identity with their counterparts in other species. A phylogenetic tree based on amino acid sequences showed that duck VLDLR proteins were closely related with those of chicken and zebra finch. The two duck <it>VLDLR </it>transcripts are differentially expressed i.e. <it>VLDLR-a </it>is mainly expressed in muscle tissue and <it>VLDLR-b </it>in reproductive organs. We have localized the duck <it>VLDLR </it>gene on chromosome Z. An association analysis using two completely linked SNP sites (T/C at position 2025 bp of the ORF and G/A in intron 13) and records from two generations demonstrated that the duck <it>VLDLR </it>gene was significantly associated with egg production (P < 0.01), age of first egg (P < 0.01) and body weight of first egg (P < 0.05).</p> <p>Conclusions</p> <p>Duck and chicken <it>VLDLR </it>genes probably perform similar function in the development of growing oocytes and deposition of yolk lipoprotein. Therefore, <it>VLDLR </it>could be a candidate gene for duck egg performance and be used as a genetic marker to improve egg performance in ducks.</p
Hepatitis E Virus Infection in Central China Reveals No Evidence of Cross-Species Transmission between Human and Swine in This Area
Hepatitis E virus (HEV) is a zoonotic pathogen of which several species of animal were reported as reservoirs. Swine stands out as the major reservoir for HEV infection in humans, as suggested by the close genetic relationship of swine and human virus. Since 2000, Genotype 4 HEV has become the dominant cause of hepatitis E disease in China. Recent reports showed that genotype 4 HEV is freely transmitted between humans and swine in eastern and southern China. However, the infection status of HEV in human and swine populations in central China is still unclear. This study was conducted in a rural area of central China, where there are many commercial swine farms. A total of 1476 serum and 554 fecal specimens were collected from the general human and swine populations in this area, respectively. The seroepidemiological study was conducted by enzyme-linked immunosorbent assay. Conserved genomic sequences of open reading frame 2 were detected using reverse transcription-PCR. The results indicated that the overall viral burden of the general human subjects was 0.95% (14/1476), while 7.0% (39/554) of the swine excreted HEV in stool. The positive rate of anti-HEV IgG and IgM in the serum samples was 7.9% (117/1476) and 1.6% (24/1476), respectively. Phylogenetic analysis based on the 150 nt partial sequence of the capsid protein gene showed that the 53 swine and human HEV isolates in the current study all belonged to genotype 4, clustering into three major groups. However, the HEV isolates prevalent in the human and swine populations were classified into known distinct subgenotypes, which suggested that no cross-species transmission between swine and humans had taken place in this area. This result was confirmed by cloning and phylogenetic analysis of the complete capsid protein gene sequence of three representative HEV strains in the three major groups. The cross reactivity between anti-HEV IgG from human sera and the two representative strains from swine in central China was confirmed by Dot-blot assay. In conclusion, although all the HEV strains prevalent in central China belonged to genotype 4, there is no evidence of cross-species transmission between human and swine in this area
Observation of a charged charmoniumlike structure in at GeV
We study the process at a
center-of-mass energy of 4.26GeV using a 827pb data sample obtained with
the BESIII detector at the Beijing Electron Positron Collider. Based on a
partial reconstruction technique, the Born cross section is measured to be
pb. We observe a structure near the
threshold in the recoil mass spectrum, which we denote as the
. The measured mass and width of the structure are
MeV/c and MeV, respectively. Its
production ratio is determined to be . The first uncertainties
are statistical and the second are systematic.Comment: 7 pages, 4 figures, 1 table; version accepted to be published in PR
Precision measurement of the branching fractions of J/psi -> pi+pi-pi0 and psi' -> pi+pi-pi0
We study the decays of the J/psi and psi' mesons to pi+pi-pi0 using data
samples at both resonances collected with the BES III detector in 2009. We
measure the corresponding branching fractions with unprecedented precision and
provide mass spectra and Dalitz plots. The branching fraction for J/psi ->
pi+pi-pi0 is determined to be (2.137 +- 0.004 (stat.) +0.058-0.056 (syst.)
+0.027-0.026 (norm.))*10-2, and the branching fraction for psi' -> pi+pi-pi0 is
measured as (2.14 +- 0.03 (stat.) +0.08-0.07 (syst.) +0.09-0.08 (norm.))*10-4.
The J/psi decay is found to be dominated by an intermediate rho(770) state,
whereas the psi' decay is dominated by di-pion masses around 2.2 GeV/c2,
leading to strikingly different Dalitz distributions.Comment: 15 pages, 2 figure
Study of and
The decays and have been
investigated with a sample of 225.2 million events collected with the
BESIII detector at the BEPCII collider. The branching fractions are
determined to be and . Distributions of the angle
between the proton or anti-neutron and the beam direction are well
described by the form , and we find
for and
for . Our branching-fraction
results suggest a large phase angle between the strong and electromagnetic
amplitudes describing the decay.Comment: 16 pages, 13 figures, the 2nd version, submitted to PR
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