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1.
Sci Rep ; 14(1): 2985, 2024 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-38316850

RESUMO

As significant evidence of ice-rich permafrost degradation due to climate warming, thermokarst lake was developing and undergoing substantial changes. Thermokarst lake was an essential ecosystem component, which significantly impacted the global carbon cycle, hydrology process and the stability of the Qinghai-Tibet Engineering Corridor. In this paper, based on Sentinel-2 (2021) and Landsat (1988-2020) images, thermokarst lakes within a 5000 m range along both sides of Qinghai-Tibet Highway were extracted to analyse the spatio-temporal variations. The results showed that the number and area of thermokarst lake in 2021 were 3965 and 4038.6 ha (1 ha = 10,000 m[Formula: see text]), with an average size of 1.0186 ha. Small thermokarst lakes ([Formula: see text]1 ha) accounted for 85.65% of the entire lake count, and large thermokarst lakes ([Formula: see text]10 ha) occupied for 44.92% of the whole lake area. In all sub-regions, the number of small lake far exceeds 75% of the total lake number in each sub-region. R1 sub-region (around Wudaoliang region) had the maximum number density of thermokarst lakes with 0.0071, and R6 sub-region (around Anduo region) had the minimum number density with 0.0032. Thermokarst lakes were mainly distributed within elevation range of 4300 m-5000 m a.s.l. (94.27% and 97.13% of the total number and size), on flat terrain with slopes less than 3[Formula: see text] (99.17% and 98.47% of the total number and surface) and in the north, south, and southeast aspects (51.98% and 50.00% of the total number and area). Thermokarst lakes were significantly developed in warm permafrost region with mean annual ground temperature (MAGT) > - 1.5 [Formula: see text]C, accounting for 47.39% and 54.38% of the total count and coverage, respectively. From 1988 to 2020, in spite of shrinkage or even drain of small portion of thermokarst lake, there was a general expansion trend of thermokarst lake with increase in number of 195 (8.58%) and area of 1160.19 ha (41.36%), which decreased during 1988-1995 (- 702 each year and - 706.27 ha/yr) and then increased during 1995-2020 (184.96-702 each year and 360.82 ha/yr). This significant expansion was attributed to ground ice melting as rising air temperature at a rate of 0.03-0.04 [Formula: see text]C/yr. Followed by the increasing precipitation (1.76-3.07 mm/yr) that accelerated the injection of water into lake.

2.
Nat Comput Sci ; 3(10): 839-848, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-38177757

RESUMO

Gaussian boson sampling (GBS) has the potential to solve complex graph problems, such as clique finding, which is relevant to drug discovery tasks. However, realizing the full benefits of quantum enhancements requires large-scale quantum hardware with universal programmability. Here we have developed a time-bin-encoded GBS photonic quantum processor that is universal, programmable and software-scalable. Our processor features freely adjustable squeezing parameters and can implement arbitrary unitary operations with a programmable interferometer. Leveraging our processor, we successfully executed clique finding on a 32-node graph, achieving approximately twice the success probability compared to classical sampling. As proof of concept, we implemented a versatile quantum drug discovery platform using this GBS processor, enabling molecular docking and RNA-folding prediction tasks. Our work achieves GBS circuitry with its universal and programmable architecture, advancing GBS toward use in real-world applications.


Assuntos
Lesões Acidentais , Humanos , Simulação de Acoplamento Molecular , Descoberta de Drogas , Distribuição Normal , Fótons
3.
Front Plant Sci ; 13: 1109953, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36743579

RESUMO

Introduction: Potato tubers have the healing capacity to prevent surface water transpiration and pathogen invasion after mechanical damage. Previous research has shown the inability to form healing periderm in potatoes under low temperatures, but the potential mechanism is still unclear. Methods: To explore the effects and mechanisms of low-temperature potato healing, wounded potatoes were stored at low temperature (4°C) and room temperature (22°C), respectively. Results: In this study, compared with 22°C healing, low temperature reduced the content of hydrogen peroxide, and the down-regulation of StAMY23 inhibited the conversion of starch to sugar, alleviated the degradation of starch, and reduced the content of soluble sugars and sucrose. Meanwhile, inhibition of phenylalanine metabolism by suppression of StPAL1 and St4CL expression reduced lignin accumulation. Low temperature also down-regulated the expression of StKCS6, StFAOH, StGPAT5, and StPrx, causing the lower deposition amount of suberin in wounds of potato tubers. Discussion: The above results suggested that low temperature led to less wound tissue deposition at the wound surfaces via suppressing phenylpropanoid metabolism and fatty acid biosynthesis in potato tubers.

4.
Biomed Pharmacother ; 141: 111830, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34146851

RESUMO

Lung cancer treatment using cisplatin (DDP) in combination with other drugs are effective for the treatment of non-small cell lung cancer (NSCLC). The aim of this study was to prepare a layer-by-layer nanoparticles (NPs) for the co-loading of DDP and oridonin (ORI) and to evaluate the antitumor activity of the system in vitro and in vivo. Novel DDP and ORI co-loaded layer-by-layer NPs (D/O-NPs) were constructed. The mean diameter, surface change stability and drug release behavior of NPs were evaluated. In vitro cytotoxicity of D/O-NPs was investigated against DDP resistant human lung cancer cell line (A549/DDP cells), and in vivo anti-tumor efficiency of D/O-NPs was tested on mice bearing A549/DDP cells xenografts. D/O-NPs have a diameter of 139.6 ± 4.4 nm, a zeta potential value of +13.8 ± 1.6 mV. D/O-NPs could significantly enhance in vitro cell toxicity and in vivo antitumor effect against A549/DDP cells and lung cancer animal model compared to the single drug loaded NPs and free drugs. The results demonstrated that the D/O-NPs could be used as a promising lung cancer treatment system.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Células A549 , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos Fitogênicos/administração & dosagem , Cápsulas , Linhagem Celular Tumoral , Cisplatino/administração & dosagem , Diterpenos do Tipo Caurano/administração & dosagem , Liberação Controlada de Fármacos , Sinergismo Farmacológico , Humanos , Lipídeos , Camundongos , Camundongos Endogâmicos BALB C , Nanopartículas , Tamanho da Partícula , Ensaios Antitumorais Modelo de Xenoenxerto
5.
Mol Clin Oncol ; 14(2): 25, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33335733

RESUMO

Although the incidence of lung cancer is increasing worldwide, the molecular mechanisms for its tumorigenesis, progression and prognosis remain unknown. As a member of the tumor necrosis factor superfamily, vascular endothelial growth inhibitor (VEGI) is involved in the development and progression of many malignant diseases. In the present study, the expression of VEGI and CD31 was examined via immunohistochemistry in non-small cell lung cancer (NSCLC) tissues obtained from 150 patients with NSCLC. The inhibitory effect of VEGI on tumor-associated blood vessel formation and growth was investigated by determining the relationship between VEGI protein expression and microvascular density (MVD). Prognostic significance was evaluated using the Kaplan-Meier method. VEGI expression was downregulated or lost in 68.7% (103/150) of patients with NSCLC, an effect that was more prevalent in adenocarcinoma (AC), 76.0% (57/75), than in squamous cell carcinoma, 61.3% (46/75). A significant negative correlation was indentified between VEGI expression and lymphovascular invasion (P=0.039) and lymph node metastasis (P=0.017) in AC tissue. Additionally, MVD was significantly lower in the VEGI-rich group compared with the VEGI-poor group. The downregulation of VEGI expression was also associated with poorer overall survival (P=0.011) in patients with AC. The present study therefore provides evidence that VEGI may be a new and effective prognostic marker of lung AC.

6.
Materials (Basel) ; 13(16)2020 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-32781610

RESUMO

The tensile strength evolution and strengthening mechanism of Cu-Fe in-situ composites were investigated using both experiments and theoretical analysis. Experimentally, the tensile strength evolution of the in-situ composites with a cold deformation strain was studied using the model alloys Cu-11Fe, Cu-14Fe, and Cu-17Fe, and the effect of the strain on the matrix of the in-situ composites was studied using the model alloys Cu-3Fe and Cu-4.3Fe. The tensile strength was related to the microstructure and to the theoretical strengthening mechanisms. Based on these experimental data and theoretical insights, a mathematical model was established for the dependence of the tensile strength on the cold deformation strain. For low cold deformation strains, the strengthening mechanism was mainly work hardening, solid solution, and precipitation strengthening. Tensile strength can be estimated using an improved rule of mixtures. For high cold deformation strains, the strengthening mechanism was mainly filament strengthening. Tensile strength can be estimated using an improved Hall-Petch relation.

7.
Cancer Biol Ther ; 21(9): 806-814, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32687454

RESUMO

Globally, lung cancer is known as a major cause of cancer-associated death and non-small-cell lung cancer (NSCLC) accounts for majority of all cases. Growing evidence has emerged that long non-coding RNAs (lncRNAs) act as vital regulatory molecules in various malignancies. Nevertheless, the function of SLCO4A1 antisense RNA 1(SLCO4A1-AS1) in NSCLC is vague. This study intended to investigate the biological role and probable regulatory mechanism of SLCO4A1-AS1 in NSCLC. qRT-PCR revealed that SLCO4A1-AS1 level was upregulated in NSCLC. Function assays manifested that silence of SLCO4A1-AS1 attenuated NSCLC cell proliferation, migration and invasion but promoted NSCLC cell apoptosis. Furthermore, we disclosed that SLCO4A1-AS1 activated NF-κB pathway in NSCLC, and that IKKα, an NF-κB pathway-related gene, possessed an enhanced level in NSCLC tissues and cells. Importantly, miR-223-3p bound with SLCO4A1-AS1 and IKKα. Further, SLCO4A1-AS1 competitively bound with miR-223-3p to increase IKKα expression, thereby activating NF-κB signaling pathway. In conclusion, SLCO4A1-AS1 drove NSCLC progression by activating NF-κB signaling pathway via sponging miR-223-3p to enhance IKKα expression. Thus, SLCO4A1-AS1 might be a promising biomarker for NSCLC treatment.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/metabolismo , Quinase I-kappa B/metabolismo , Neoplasias Pulmonares/metabolismo , MicroRNAs/metabolismo , NF-kappa B/metabolismo , Transportadores de Ânions Orgânicos/genética , RNA Longo não Codificante/metabolismo , Células A549 , Animais , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/patologia , Proliferação de Células/fisiologia , Progressão da Doença , Xenoenxertos , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Camundongos , Camundongos Nus , RNA Antissenso/genética , RNA Antissenso/metabolismo , RNA Longo não Codificante/genética , Transdução de Sinais
8.
J Sci Food Agric ; 97(14): 4697-4703, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28369919

RESUMO

BACKGROUND: The polarities of linolenic acid isomers are very similar, and only a few studies to date have attempted to separate α-linolenic acid (ALA) isomers completely. The aim of this study was to fill this gap by developing and validating an accurate method for the analysis of ALA isomers in trilinolenin at 200, 220 and 240 °C using a gas chromatograph-flame ionization detector equipped with an SLB-IL111 capillary column. RESULTS: Results showed that eight ALA isomer standards were separated effectively using these optimized gas chromatographic conditions. The coefficient of determination was r2 > 0.9994 in the linear range of each ALA isomer. The obtained limits of detection and limits of quantification of the ALA isomers were 0.02-0.08 ppm and 0.05-0.22 ppm, respectively. A high degree of reproducibility and percent recoveries between 96.2% and 106.5%, with coefficients of variation ranging from 0.82% to 0.97%, were achieved. CONCLUSION: The developed method has been successfully applied to the analysis of ALA isomers in heated pure trilinolenin as well as to trilinolenin in various edible oils, and the TALA isomerization pathways in heated trilinolenin were verified. © 2017 Society of Chemical Industry.


Assuntos
Cromatografia Gasosa/métodos , Óleos de Plantas/química , Triglicerídeos/química , Ácido alfa-Linolênico/análise , Temperatura Alta , Líquidos Iônicos , Isomerismo , Limite de Detecção , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Ácido alfa-Linolênico/química
9.
J Sci Food Agric ; 97(6): 1861-1867, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27507439

RESUMO

BACKGROUND: To clarify the formation mechanism of trans linoleic acid isomers in edible oils during the heating process, trilinolein and trilinoelaidin, as representative oils, were placed in glass ampoules and sealed before heating at 180, 240 and 320 °C. The glass ampoules were removed at regular time intervals, and the contents were analyzed by infrared spectroscopy. The samples were then subjected to derivatization into their methyl esters for gas chromatographic analysis. RESULTS: Analysis results show that 9c,12c and 9t,12t fatty acids from trilinolein and trilinoelaidin molecules undergo chemical bond rotation, migration and degradation, leading to the formation of non-conjugated linoleic acids (NLAs), conjugated linoleic acids (CLAs) and aldehydes. The formation rate of isomers from the 9c,12c fatty acid is higher than that of the 9t,12t fatty acid. The production of aldehydes increases with heating temperature and time. The isomerization pathways involved in the formation of NLAs and CLAs during heating are clearly presented. CONCLUSION: These findings suggest possible pathways of NFA and CFA formation from heated trilinolein and trilinoelaidin, complement the mechanistic studies previously published in the literature, and provide a theoretical basis for future control of the quality and safety of fats and oils. © 2016 Society of Chemical Industry.


Assuntos
Ácido Linoleico/química , Óleos de Plantas/química , Triglicerídeos/química , Cromatografia Gasosa , Culinária , Temperatura Alta , Isomerismo , Ácidos Linoleicos Conjugados/química , Estrutura Molecular
10.
J Food Sci Technol ; 53(3): 1487-95, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27570273

RESUMO

The effects of technical cashew nut shell liquid (TCNSL) on the trans isomerization of edible oils during heating are investigated. Edible oils were subjected to thermal treatment at various heating times and temperatures. Our results show that the addition of TCNSL to edible oils at the appropriate concentration during heating suppresses trans fatty acid formation and induces formation of conjugated linoleic acid (CLA) isomers. A concentration of 0.2 % TCNSL demonstrates the best ability to inhibit formation of trans-oleic acid, trans-linoleic acid, and trans-linolenic acid isomers as well as increase the formation of 9 t,11 t-CLA and 10 t,12 t-CLA isomers. Our analysis indicates that the presence of 0.2 % TCNSL in corn oil does not significantly reduce the acid value, but may significantly lower the peroxide value. TCNSL is also observed to have better function compared to Vitamin E (VE) and tertiary butylhydroquinone (TBHQ), indicating that it may be considered an effective additive in edible oils.

11.
Carbohydr Polym ; 125: 288-300, 2015 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-25857986

RESUMO

The ß-cyclodextrin-acrylamide (CDM-AM) copolymer was prepared from acrylamide and ß-CD maleate (CDM) using K2S2O8 as initiator. The effects of the CDM-AM copolymer on the solubility and fungicidal activity of natamycin (NM) and carbendazim (MBC) were investigated. The stability constant of NM·CDM-AM and MBC·CDM-AM complexes at 303 K were of 10,725.45 M(-1) and 3000.89 M(-1), respectively. The complexes were characterized using phase solubility diagrams, NMR spectra and FT-IR spectra. The analysis of the biological activities of these two complexes indicated that they possessed enhancing fungicidal activities compared to NM and MBC alone.


Assuntos
Acrilamida/química , Antifúngicos/síntese química , Benzimidazóis/química , Carbamatos/química , Natamicina/química , Polímeros/síntese química , beta-Ciclodextrinas/química , Antifúngicos/farmacologia , Aspergillus niger/efeitos dos fármacos , Benzimidazóis/farmacologia , Carbamatos/farmacologia , Natamicina/farmacologia , Polímeros/farmacologia
12.
Carbohydr Res ; 404: 55-62, 2015 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-25665779

RESUMO

ß-CD maleate (CDM) and ß-CD itaconate (CDI) were prepared by esterification of ß-cyclodextrin (ß-CD) with maleic acid and itaconic acid using phosphate as a catalyst in a semi-dry process. The esterification of ß-CD was carried out using [Itaconic acid ] or [Maleic acid ] 4 mol/mol of CD; M/L ratio 1:0.6; temperature 110 °C; [4-methoxyphenol] 2.5% amount of acid; reaction time 3.5h. The esterification rates of CDM and CDI are 70.38% and 21.02%, respectively. We found that CDM and CDI were both monoesters. Here, we also established a new evaluation method for the rate of esterification.


Assuntos
beta-Ciclodextrinas/química , beta-Ciclodextrinas/síntese química , Esterificação , Espectroscopia de Ressonância Magnética , Maleatos/química , Estrutura Molecular , Succinatos/química , Termogravimetria
13.
Zhongguo Zhong Yao Za Zhi ; 40(16): 3314-8, 2015 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-26790313

RESUMO

In recent years, the incidence of tic disorders has increased, and it is not uncommon for the patients to treat the disease. The pathogenesis and pathogenesis of Western medicine are not yet clear, the clinical commonly used western medicine has many adverse reactions, traditional Chinese medicine (TCM) research is increasingly valued. Based on the software of TCM inheritance assistant system, this paper discusses Ding Yuanqing's experience in treating tic disorder with Professor. Collect yuan Qing Ding professor in treating tic disorder of medical records by association rules Apriori algorithm, complex system entropy clustering without supervision and data mining method, carries on the analysis to the selected 800 prescriptions, to determine the frequency of use of prescription drugs, the association rules between the drug and digging out the 12 core combination and the first six new prescription, medication transferred to the liver and extinguish wind, cooling blood and relieving convulsion, Qingxin soothe the nerves, with the card cut, flexible application, strict compatibility.


Assuntos
Medicamentos de Ervas Chinesas/uso terapêutico , Transtornos de Tique/tratamento farmacológico , Mineração de Dados , Bases de Dados Bibliográficas , Prescrições de Medicamentos , Quimioterapia Combinada , Medicamentos de Ervas Chinesas/química , Humanos , Resultado do Tratamento
14.
Food Chem ; 174: 299-305, 2015 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-25529684

RESUMO

Trilinolein, with or without additives, was placed in glass ampoules and subjected to thermal treatment at 180 °C or 240 °C for 8h. Thermal treatment of trilinolein at 180 °C and 240 °C produced twice the amount of trans nonconjugated linoleic acids (NLAs) compared to conjugated linoleic acids (CLAs), and nitrogen stream reduced the amount of both trans NLA and CLA products. The presence of additives resulted in the suppression or induction of trans NLAs and CLAs, depending on the type of additive, the concentration of the additive, and the heating temperature. Our analysis indicates that TBHQ is an effective additive for reducing trans NLA formation and inducing trans CLA formation in frying oil. Glutathione and L-cysteine at 0.1% may also be used as additives for frying oil. At suitable concentrations, Fe(3+) and Al(3+) ions derived from oils can reduce trans NLAs and induce trans CLAs during frying.


Assuntos
Ácidos Graxos trans/química , Triglicerídeos/química , Hidroxianisol Butilado/farmacologia , Hidroxitolueno Butilado/farmacologia , Cromatografia Gasosa , Culinária , Cisteína/farmacologia , Temperatura Alta , Hidroquinonas/farmacologia , Isomerismo , Ácido Linoleico/química , Ácidos Linoleicos Conjugados/química , Vitamina E/farmacologia
15.
Cell Biochem Biophys ; 66(2): 309-18, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23212180

RESUMO

Fibroblasts can be reprogrammed by ectopic expression of reprogramming factors to yield induced pluripotent stem (iPS) cells that are capable of transdifferentiating into diverse types of somatic cell lines. In this study, we examined if functional cardiomyocytes (CMs) can be produced from mouse cardiac fibroblasts (CFs), using iPS cell factor-based reprogramming. CFs were isolated from Oct4-GFP-C57 mice and infected with a retrovirus expressing the Yamanaka reprogramming factors, Oct4, Sox2, Klf4, and c-Myc to reprogram the CFs into a CF-iPS cell line. Primary mouse embryonic fibroblast cells (MEFs) were used as a control. We found that the dedifferentiated CF-iPS cells showed similar biological characteristics (morphology, pluripotent factor expression, and methylation level) as embryonic stem cells (ESs) and MEF-iPS cells. We used the classical embryoid bodies (EBs)-based method and a transwell CM co-culture system to simulate the myocardial paracrine microenvironment for performing CF-iPS cell cardiogenic differentiation. Under this simulated myocardial microenvironment, CF-iPS cells formed spontaneously beating EBs. The transdifferentiated self-beating cells expressed cardiac-specific transcription and structural factors and also displayed typical myocardial morphology and electrophysiological characteristics. CFs can be dedifferentiated into iPS cells and further transdifferentiated into CMs. CFs hold great promise for CM regeneration as an autologous cell source for functional CM in situ without the need for exogenous cell transplantation in ischemic heart disease.


Assuntos
Reprogramação Celular , Fibroblastos/citologia , Miócitos Cardíacos/citologia , Animais , Diferenciação Celular , Células Cultivadas , Reprogramação Celular/efeitos dos fármacos , Técnicas de Cocultura , Corpos Embrioides/fisiologia , Fibroblastos/efeitos dos fármacos , Células-Tronco Pluripotentes Induzidas/citologia , Fator 4 Semelhante a Kruppel , Fatores de Transcrição Kruppel-Like/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Fator 3 de Transcrição de Octâmero/farmacologia , Proteínas Proto-Oncogênicas c-myc/farmacologia , Fatores de Transcrição SOXB1/farmacologia
16.
J Agric Food Chem ; 60(42): 10709-13, 2012 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-23025355

RESUMO

The intake of edible oil containing trans-fatty acids has deleterious effects mainly on the cardiovascular system. Thermal processes such as refining and frying cause the formation of trans-fatty acids in edible oil. This study was conducted to investigate the possible formation of trans-fatty acids because of the heat treatment of soybean oil. The types of trans-fatty acids in heated soybean oil are determined by attenuated total reflectance Fourier transform infrared spectroscopy and gas chromatography-mass spectrometry methods. The effects of the heating temperature on the trans-fatty acids in soybean oil were evaluated using gas chromatography flame ionization detection analysis. Results show that heat treatment at 240 °C causes the formation of trans-fatty acids in soybean oil and the amount of trans-fatty acids increases with heating time. The only peak observed at 966 cm(-1) of the samples indicates the formation of nonconjugated trans isomers in the heated soybean oil. The major types of trans-fatty acids formed were trans-polyunsaturated fatty acids. Significant increases (P < 0.05) in the amounts of two trans-linoleic acids (C18:2-9c,12t and C18:2-9t,12c) and four trans-linolenic acids (C18:3-9c,12c,15t, C18:3-9t,12c,15c, and C18:3-9t,12t,15c/C18:3-9t,12c,15t) in soybean oil heated to temperatures exceeding 200 °C were compared with those of the control sample. The heating temperature and duration should be considered to reduce the formation of trans-fatty acids during thermal treatment.


Assuntos
Cromatografia Gasosa/métodos , Óleo de Soja/química , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Ácidos Graxos trans/análise
17.
Environ Monit Assess ; 167(1-4): 581-6, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19603279

RESUMO

A huge amount of coal is always stored in open spaces in coal-fired power plants before combustion. Mercury released from coal by rain or flowing water is an environmental risk and can cause contamination of the soil around the storage area. To better understand mercury pollution and to control mercury emission before combustion, it is necessary to determine the mobility and leaching characteristics of mercury from coal. In this study, we collected ten coal samples from one coal-fired power plant and proposed a sequential extraction procedure to get five fractions of mercury for evaluation. Elemental Hg was found as the most dominant fraction, and sulfate Hg was shown to be the second largest fraction. The mercury in the organic and the soluble fractions were not the major fractions, but they should still be considered because of their high mobility.


Assuntos
Carvão Mineral , Mercúrio/análise , Monitoramento Ambiental , Poluentes Químicos da Água/análise
18.
Guang Pu Xue Yu Guang Pu Fen Xi ; 28(11): 2550-3, 2008 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-19271487

RESUMO

Ninety eight representative fresh mutton samples from Neimeng, Ningxia, Gansu, Xinjiang province were selected for this study, the nondestructive measurement of the fresh mutton tenderness by Fourier transform near infrared (FT-NIR) spectroscopy was discussed. Partial least squares(PLS) algorithm was used to build the model between the shear force value of the fresh mutton tenderness measured by the texture machine and the FT-NIR spectra. The influence of different processing method of spectra, factors and wave regions on the determination coefficients (r2), root mean square error of cross validation (RMSECV) and root mean square error of prediction (RMSEP) was studied. The result showed that the shear force value of ninety eight representative fresh mutton samples was 1.673-6.631 kg, and the shear force value above 75% samples was 2-5 kg, almost covering the fresh mutton tenderness of our country's sheep, the r2 of the calibration could reach 86.2% and the RMSECV was up to 0. 445 in the wave number range 11 995-5 446 cm(-1) and 4 601-4 246 cm(-1) with vector normalization when the PLS factors was ten. The correlation coefficient(R), RMSEP and average bias between value measured by the texture machine and predicted value of model based on validation samples were 0.87, 0.524 and 0.385 respectively. The result indicates that FT-NIR spectroscopy is capable of predicting tenderness value of fresh mutton.


Assuntos
Análise de Alimentos/métodos , Análise dos Mínimos Quadrados , Carne/análise , Músculo Esquelético/química , Espectroscopia de Infravermelho com Transformada de Fourier , Animais , Ovinos
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