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1.
BMC Cancer ; 24(1): 644, 2024 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-38802800

RESUMO

BACKGROUND: Understanding the metabolic changes in colorectal cancer (CRC) and exploring potential diagnostic biomarkers is crucial for elucidating its pathogenesis and reducing mortality. Cancer cells are typically derived from cancer tissues and can be easily obtained and cultured. Systematic studies on CRC cells at different stages are still lacking. Additionally, there is a need to validate our previous findings from human serum. METHODS: Ultrahigh-performance liquid chromatography tandem high-resolution mass spectrometry (UHPLC-HRMS)-based metabolomics and lipidomics were employed to comprehensively measure metabolites and lipids in CRC cells at four different stages and serum samples from normal control (NR) and CRC subjects. Univariate and multivariate statistical analyses were applied to select the differential metabolites and lipids between groups. Biomarkers with good diagnostic efficacy for CRC that existed in both cells and serum were screened by the receiver operating characteristic curve (ROC) analysis. Furthermore, potential biomarkers were validated using metabolite standards. RESULTS: Metabolite and lipid profiles differed significantly among CRC cells at stages A, B, C, and D. Dysregulation of glycerophospholipid (GPL), fatty acid (FA), and amino acid (AA) metabolism played a crucial role in the CRC progression, particularly GPL metabolism dominated by phosphatidylcholine (PC). A total of 46 differential metabolites and 29 differential lipids common to the four stages of CRC cells were discovered. Eight metabolites showed the same trends in CRC cells and serum from CRC patients compared to the control groups. Among them, palmitoylcarnitine and sphingosine could serve as potential biomarkers with the values of area under the curve (AUC) more than 0.80 in the serum and cells. Their panel exhibited excellent performance in discriminating CRC cells at different stages from normal cells (AUC = 1.00). CONCLUSIONS: To our knowledge, this is the first research to attempt to validate the results of metabolism studies of serum from CRC patients using cell models. The metabolic disorders of PC, FA, and AA were closely related to the tumorigenesis of CRC, with PC being the more critical factor. The panel composed of palmitoylcarnitine and sphingosine may act as a potential biomarker for the diagnosis of CRC, aiding in its prevention.


Assuntos
Biomarcadores Tumorais , Neoplasias Colorretais , Metabolômica , Humanos , Neoplasias Colorretais/sangue , Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Biomarcadores Tumorais/sangue , Biomarcadores Tumorais/metabolismo , Metabolômica/métodos , Cromatografia Líquida de Alta Pressão/métodos , Lipidômica/métodos , Masculino , Feminino , Pessoa de Meia-Idade , Curva ROC , Metaboloma , Espectrometria de Massas em Tandem/métodos , Estadiamento de Neoplasias , Idoso , Ácidos Graxos/metabolismo , Ácidos Graxos/sangue , Multiômica
2.
J Pharm Biomed Anal ; 234: 115582, 2023 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-37473505

RESUMO

Colorectal advanced adenoma (CAA) is a key precancerous lesion of colorectal cancer (CRC), and early diagnosis can lessen CRC morbidity and mortality. Although abnormal lipid metabolism is associated with the development of CRC, there are no studies on the biomarkers and mechanism of lipid metabolism linked to CAA carcinogenesis. Hence, we performed a lipidomics study of serum samples from 46 CAA, and 50 CRC patients by the ultra high-performance liquid chromatography tandem high resolution mass spectrometry (UHPLC-HRMS) in both electrospray ionization (ESI) modes. Differential lipids were selected by univariate and multivariate statistics analysis, and their diagnostic performance was evaluated using a receiver operating characteristic curve (ROC) analysis. Combining P < 0.05 and variable importance in projection (VIP) > 1, 59 differential lipids were obtained totally. Ten of them showed good discriminant ability for CAA and CRC (AUC > 0.900). Especially, the lipid panel consisting of PC 44:5, PC 35:6e, and SM d40:3 showed the highest selection frequency and outperformed (AUC = 0.952). Additionally, phosphatidylcholine (PC) and sphingomyelin (SM) were the main differential and high-performance lipids. In short, this is the first study to explore the biomarkers and mechanism for CAA-CRC sequence with large-scale serum lipidomics. The findings should provide valuable reference and new clues for the development of diagnostic and therapeutic strategies of CRC.


Assuntos
Adenoma , Neoplasias Colorretais , Humanos , Fosfatidilcolinas , Cromatografia Líquida de Alta Pressão , Esfingomielinas , Lipidômica , Neoplasias Colorretais/diagnóstico , Biomarcadores , Adenoma/diagnóstico
3.
PLoS One ; 17(12): e0276537, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36454917

RESUMO

In karst regions, the majority of studies have focused on ecosystem carbon sequestration in the same lithology, but no studies in different lithologies. In this study, actual measurements were used to reveal carbon sequestration characteristics of two plantation forest ecosystems (Bodinieri cinnamon and Cupressus funebris) with different lithologies of karst. The results showed that the tree layer showed the highest vegetation biomass, carbon content, carbon density, and ratio of aboveground biomass to belowground biomass. The carbon density of B. cinnamon plantation and C. funebris plantation was high in dolomite and in limestone respectively. The soil quality and carbon density of bare ground and plantation varied across different lithologies. The carbon density of various ecosystem components was in the order of vegetation>soil>litterfall. The carbon density and net carbon density of plantation varied across different lithologies. In B. cinnamon plantation, the carbon sequestration rate of vegetation and ecosystem was high in dolomite, moderate in limestone, and low in dolomitic sandstone. In Cupressus funebris plantation, the carbon sequestration rate was in the order of limestone>dolomite>dolomitic sandstone. These findings revealed that lithology is an important factor affecting ecosystem carbon pools, and plantation ecosystems have low biomass and low carbon density in karst areas.


Assuntos
Sequestro de Carbono , Cupressaceae , Ecossistema , Florestas , Carbonato de Cálcio , Carbono , Solo , Cinnamomum zeylanicum
4.
Plants (Basel) ; 11(22)2022 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-36432889

RESUMO

Studying the relationship between vegetation structure and diversity is important in an area having karst topography and unique traditional customs. We selected a total of six traditional villages in Zunyi City, China, to collect vegetation data. Additionally, using one-way ANOVA and the Pearson correlation coefficient analytic method to analyze, the results showed that, overall, plant communities were mostly regularly distributed. The overall differentiation degree was low aggregation, intensity, and the extreme intensity mixed state. Overall, competitive pressure, growth vigor and stability were better than the natural forest. The community stability index at lower altitude was significantly higher than that at higher altitude. The recorded plant communities in the living space were typically aggregated, the plant communities were randomly distributed in the production space, and the plant communities were uniformly distributed in the ecological space. In general, the diversity indexes, except the Jh index, were the highest in the herb layer; the second was in the shrub layer and the lowest was in the tree layer. Species diversity at the middle altitude was higher than that at low and high altitudes (except for the shrub at a high altitude of 1100-1160 m). The overall plant species diversity was highest in the living space, second highest in the ecological space and lowest in the production space. On the whole, there was a significant correlation between the spatial structure of plant communities and the species diversity of plant communities at different altitudes, and in PLE spaces. The main objective of this study was to reveal the plant community structure, species diversity, and their relationship under the dual effects of national traditional culture and karst landform. Additionally, we sought to provide theoretical guidance for the construction of plant community protection and biodiversity conservation in traditional villages in karst areas.

6.
Environ Sci Pollut Res Int ; 29(9): 12629-12647, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34462860

RESUMO

To find out the genuine characteristics of Eucommia ulmoides produced in Guizhou.The habitat, functional characters and the content of medicinal components of Eucommia ulmoides in Guizhou were studied by using the method of sample survey combined with typical survey, related laboratory experiments and quantitative analysis. The results showed that the yield of Eucommia ulmoides plantation in Guizhou was divided into low altitude, low middle and high temperature rain slope latitude mixing, short sunshine hours type(A type), medium altitude, low longitude and latitude, high temperature rain, positive oblique steep slope, medium sunshine hours type (B type), middle altitude, low longitude and latitude, moderate high temperature rain, shady side and sunny side have gentle deflection steep slope, medium sunshine hours type (C type), High altitude, low longitude and latitude, low temperature moderate rain, positive gentle slope, long sunshine hours type (D type); Different types of Eucommia ulmoides plantation, Different habitat quality, B type is intensity karst rocky desertification habitat, A type is potential karst rocky desertification habitat, the C and D types are light and moderate rocky desertification areas, respectively, the species diversity of shrub layer in Eucommia ulmoides plantation was higher in D type and B type, A type and C type followed; There was no significant difference in root carbon content and leaf nitrogen content in 4 types of Eucommia ulmoides plantation, Among the four types of A, B, C, D, there were significant or extremely significant differences in other indexes of plant functional traits; Both genipinic acid and aucubin had the highest content of root bark, followed by trunk bark and lowest leaves, Chlorogenic acid is the opposite, The content of geniposide was higher in trunk bark and lower in root bark and leaves; Genipinic acid is higher in D type, Aucubin is higher in A and D type, Chlorogenic acid has higher leaves content in B type, Geniposide was the highest in trunk bark of D type; The element enrichment coefficient K and Mn leaves are the largest, the largest in trunk bark is Ca and Zn, Fe root bark is the largest; Effects of soil potassium, phosphorus, pH value and bulk weight on the functional traits of Eucommia ulmoides were significant. The contents of medicinal components in root bark, trunk bark, and leaves was influenced by species diversity of shrub layer, The contents of geniposide in root bark, aucubin in root bark and trunk bark, genipinic acid in bark and chlorogenic acid in leaves were particularly affected by soil physical and chemical indexes and metal element contents, The functional traits of Eucommia ulmoides can affect the content of medicinal components in root bark, trunk bark, and leaves, Especially on the root bark, trunk bark, and leaves in the content of aucubin content; The content of medicinal components of Eucommia ulmoides was high and stable. The above research results have important theoretical reference significance for the cultivation of Eucommia ulmoides and the cultivation of target medicinal components and the comprehensive exploitation and utilization of resources.


Assuntos
Eucommiaceae , Ácido Clorogênico , Ecossistema , Fenótipo , Folhas de Planta
7.
Cancer Manag Res ; 13: 8865-8878, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34858060

RESUMO

BACKGROUND: As a key precancerous lesion, colorectal advanced adenoma (CAA) is closely related to the occurrence and development of colorectal cancer (CRC). Effective identification of CAA-related biomarkers can prevent CRC morbidity and mortality. Lipids, as an important endogenous substance, have been proved to be involved in the occurrence and development of CRC. Lipidomics is an advanced technique that studies lipid metabolism and biomarkers of diseases. However, there are no lipidomics studies based on large serum samples to explore diagnostic biomarkers for CAA. METHODS: An integrated serum lipid profile from 50 normal (NR) and 46 CAA subjects was performed using ultra-high performance liquid chromatography tandem high-resolution mass spectrometry (UHPLC-HRMS). Lipidomic data were acquired for negative and positive ionization modes, respectively. Differential lipids were selected by univariate and multivariate statistics analyses. A receiver operator characteristic curve (ROC) analysis was conducted to evaluate the diagnostic performance of differential lipids. RESULTS: A total of 53 differential lipids were obtained by combining univariate and multivariate statistical analyses (P < 0.05 and VIP > 1). In addition, 12 differential lipids showed good diagnostic performance (AUC > 0.90) for the discrimination of NR and CAA by receiver operating characteristic curve (ROC) analysis. Of them, the performance of PC 44:5 and PC 35:6e presented the outstanding performance (AUC = 1.00, (95% CI, 1.00-1.00)). Moreover, triglyceride (TAG) had the highest proportion (37.74%) as the major dysregulated lipids in the CAA. CONCLUSION: This is the first study that profiled serum lipidomics and explored lipid biomarkers with good diagnostic ability of CAA to contribute to the early prevention of CRC. Twelve differential lipids that effectively discriminate between NR and CAA serve as the potential diagnostic markers of CAA. An obvious perturbation of TAG metabolism could be involved in the CAA formation.

8.
PLoS One ; 16(7): e0254013, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34228763

RESUMO

Understanding the impact of irrigation and fertilizer on rabbiteye blueberry (Vaccinium virgatum) physiology is necessary for its precision planting. Here, we applied varied irrigation and fertilizer under completely randomized experimental design to see its impact on the physiological characteristics and bush growth of rabbiteye blueberries. A comprehensive evaluation of the membership function was used to establish the best water-fertilizer coupling regimes. Rabbiteye blueberry enhanced the net photosynthetic rate, stomatal conductance and transpiration rate of leaf and improved its photosynthetic capacity at maximum level of irrigation water and fertilizer application (F3W4). The high fertilizer-medium water treatment (F3W3) increased leaf-soluble protein contents. The medium fertilizer-medium water treatment (F2W3, F2W2) increased leaf- soluble sugar, superoxide dismutase, and chlorophyll contents; decreased the malondialdehyde content; and enhanced leaf resistance and metabolism. It also promoted the growth of flower buds and new shoots. Combined membership function and cluster analyses revealed that the optimal water and fertilizer conditions for promoting rabbiteye blueberry plant growth were the medium fertilizer-medium water [(NH4)2SO4:Ca(H2PO4)2:K2SO4 at 59:10:20 g plant-1; 2.5 L water plant-1], medium fertilizer-medium-high water [(NH4)2SO4:Ca(H2PO4)2:K2SO4 at 59:10:20 g plant-1; 3.75 L water plant-1], and high fertilizer-medium-high water [(NH4)2SO4:Ca(H2PO4)2:K2SO4 at 118:20:40 g plant-1; 3.75 L water plant-1] treatments. The findings of this study could be used in improving the precision and efficacy of rabbiteye blueberry planting in Guizhou, China. Such an approach can increase the productivity and profitability for local fruit farmers.


Assuntos
Mirtilos Azuis (Planta)/crescimento & desenvolvimento , Mirtilos Azuis (Planta)/fisiologia , Fertilizantes , Água , Análise por Conglomerados , Fotossíntese , Folhas de Planta/fisiologia
9.
Ying Yong Sheng Tai Xue Bao ; 31(8): 2687-2698, 2020 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-34494792

RESUMO

Green space ecological network is important for improving the fragmentation of regional ecological space, biodiversity loss, imbalance of supply and demand in ecosystem services, and ensuring regional ecology. With Dongting Lake region as an example, the ecological sources were evaluated and identified, and basic ecological resistance of grid element was calculated from the perspectives of comprehensive ecosystem service function evaluation, potential biodiversity comprehensive index evaluation and morphological spatial pattern analysis with the support of 3S technology. We corrected the basic ecological resistance by night light index, used the minimum cumulative resistance model to identify ecological corridors, and constructed a weighted evaluation model, eva-luated the degree of aggregation and dispersion of the sources, as well as the contribution of ecological connection of the corridors. Furthermore, we compared and evaluated the structural characteristic index of the integrated networks, the potential "source sink" networks and the planning networks. The results showed that the spatial distribution of the sources was uneven, with forest land, shrubland and wetland acounting for 95.9% of the total area. The Dongting Lake wetland located in the middle of the region was at high ecological risk. The closer the source was to the center of the ecological network system and the smaller the average minimum cumulative resistance was to other sources, the stronger the advantages of aggregation and dispersion. The denser the distribution of medium and high ecological quality sources was around the high ecological quality sources, the higher the aggregation and dispersion. The closer the corridor was to the high ecological quality sources, the greater contribution of ecological connection. Forest land, shrubland, especially river played an important role in connecting natural ecosystem and human social system. The "source-sink" planning greenways formed a supplement to the "source-sink" potential ecological corridors. Compared with the "source-sink" potential network, the α, ß, γ and ρ index of the integrated network was increased by 123.1%, 25.8%, 26.2% and 74.6% respectively. Compared with the "source-sink" planning network, the α, ß, γ and ρ index was increased by 190.0%, 31.1%, 32.5% and 114.6% respectively. The results could provide reference for the construction of green space ecological network and planning of land use in Dongting Lake region.


Assuntos
Conservação dos Recursos Naturais , Ecossistema , Biodiversidade , China , Ecologia , Humanos , Lagos , Parques Recreativos
10.
Dis Markers ; 2019: 8949618, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31089400

RESUMO

BACKGROUND: The role of miR-200c in gastric cancer remains controversial. This study is aimed at clarifying the diagnostic and prognostic value of miR-200c in gastric cancer through a meta-analysis. METHODS: A comprehensive literature search of PubMed, Embase, and Ovid library databases was conducted. The studies included were those conducted before December 2017. The sensitivity and specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and area under curve (AUC) were used to estimate the diagnostic value of miR-200c. Meanwhile, the pooled hazard ratio (HR) was used to estimate the prognostic value of miR-200c. RESULTS: For the diagnostic value of miR-200c, six studies that included 202 patients with gastric cancer and 250 normal controls were analyzed. The sensitivity, specificity, PLR, NLR, DOR, and AUC were 0.74, 0.66, 2.20, 0.40, 5.34, and 0.75, respectively. Subgroup analysis showed no significant difference in the type of the sample, method for testing miR-200c, and ethnicity among the patients. Meanwhile, for the prognostic value of miR-200c, seven studies comprising 935 patients with gastric cancer were analyzed. The pooled results showed that miR-200c expression was associated with overall survival (HR = 2.19) and disease-free survival (HR = 1.73), but not with progression-free survival (HR = 1.64) in patients with gastric cancer. There was no publication bias across the studies. CONCLUSIONS: Both serum and tissue miR-200c have moderate diagnostic accuracy in gastric cancer. miR-200c could also be used as a valuable indicator for predicting the prognosis of gastric cancer patients.


Assuntos
Biomarcadores Tumorais/normas , MicroRNAs/normas , Neoplasias Gástricas/sangue , Biomarcadores Tumorais/sangue , Biomarcadores Tumorais/metabolismo , Humanos , MicroRNAs/sangue , MicroRNAs/metabolismo , Valor Preditivo dos Testes , Neoplasias Gástricas/metabolismo
11.
Int J Biol Markers ; 34(2): 117-122, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30852978

RESUMO

PURPOSE: The correlation between patatin-like phospholipase domain-containing protein 3 (PNPLA3) rs738409 polymorphism and hepatocellular carcinoma was investigated by several pilot studies, but the results of these studies were controversial. Therefore, we performed this study to better assess the relationship between PNPLA3 rs738409 polymorphism and the likelihood of hepatocellular carcinoma. METHODS: Eligible studies were searched in PubMed, Medline, EMBASE, and Web of Science. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to assess the relationship between PNPLA3 rs738409 polymorphism and hepatocellular carcinoma. RESULTS: A total of 17 studies with 10,330 participants were analyzed. A significant association with the likelihood of hepatocellular carcinoma was detected for the PNPLA3 rs738409 polymorphism in dominant (P = 0.0001; OR 0.66; 95% CI 0.53, 0.82), recessive (P < 0.0001; OR 2.32; 95% CI 1.76, 3.06) and allele (P < 0.0001; OR 0.64; 95% CI 0.53, 0.77) comparisons. Further subgroup analyses revealed that the PNPLA3 rs738409 polymorphism was significantly associated with the likelihood of hepatocellular carcinoma in Caucasians (dominant model: P < 0.0001, OR 0.57, 95% CI 0.45, 0.71; recessive model: P < 0.0001, OR 2.74, 95% CI 2.02, 3.71; allele model: P < 0.0001, OR 0.56, 95% CI 0.46, 0.67). However, no positive results were detected in Asians. CONCLUSIONS: Our findings indicated that the PNPLA3 rs738409 polymorphism may serve as a potential biological marker of hepatocellular carcinoma in Caucasians.


Assuntos
Carcinoma Hepatocelular/genética , Predisposição Genética para Doença , Lipase/genética , Neoplasias Hepáticas/genética , Proteínas de Membrana/genética , Polimorfismo de Nucleotídeo Único , Carcinoma Hepatocelular/patologia , Estudos de Casos e Controles , Humanos , Neoplasias Hepáticas/patologia , Prognóstico
12.
Appl Opt ; 55(17): 4621-31, 2016 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-27409019

RESUMO

Under dynamic conditions, the centroiding accuracy of the motion-blurred star image decreases and the number of identified stars reduces, which leads to the degradation of the attitude accuracy of the star sensor. To improve the attitude accuracy, a region-confined restoration method, which concentrates on the noise removal and signal to noise ratio (SNR) improvement of the motion-blurred star images, is proposed for the star sensor under dynamic conditions. A multi-seed-region growing technique with the kinematic recursive model for star image motion is given to find the star image regions and to remove the noise. Subsequently, a restoration strategy is employed in the extracted regions, taking the time consumption and SNR improvement into consideration simultaneously. Simulation results indicate that the region-confined restoration method is effective in removing noise and improving the centroiding accuracy. The identification rate and the average number of identified stars in the experiments verify the advantages of the region-confined restoration method.

13.
Appl Opt ; 54(25): 7559-66, 2015 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-26368878

RESUMO

The attitude accuracy of a star sensor decreases rapidly when star images become motion-blurred under dynamic conditions. Existing techniques concentrate on a single frame of star images to solve this problem and improvements are obtained to a certain extent. An attitude-correlated frames (ACF) approach, which concentrates on the features of the attitude transforms of the adjacent star image frames, is proposed to improve upon the existing techniques. The attitude transforms between different star image frames are measured by the strap-down gyro unit precisely. With the ACF method, a much larger star image frame is obtained through the combination of adjacent frames. As a result, the degradation of attitude accuracy caused by motion-blurring are compensated for. The improvement of the attitude accuracy is approximately proportional to the square root of the number of correlated star image frames. Simulations and experimental results indicate that the ACF approach is effective in removing random noises and improving the attitude determination accuracy of the star sensor under highly dynamic conditions.

14.
Appl Opt ; 53(29): 6629-34, 2014 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-25322363

RESUMO

We propose a precise rolling angle measurement for a collimator to extend its application in 3D angular deformation measurement, with performance significantly superior to that of the traditional 2D technique. The rolling angle measurement is realized by taking full advantage of the point array image, which is projected in terms of the collimated beam. The measurement error is estimated according to the proposed algorithm. The characteristics of the point array are analyzed to optimize the point array for precise measurement, including the point distribution, the point array resolution, and the point array area. Both simulations and experiments demonstrate that subarcsecond precision rolling angle measurement is achieved by our method, which is superior to those attained by other proposed targets.

15.
Sensors (Basel) ; 14(9): 16322-42, 2014 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-25192311

RESUMO

A new method for dynamic measurement of deflections of the vertical (DOV) is proposed in this paper. The integration of an inertial navigation system (INS) and global navigation satellite system (GNSS) is constructed to measure the body's attitude with respect to the astronomical coordinates. Simultaneously, the attitude with respect to the geodetic coordinates is initially measured by a star sensor under quasi-static condition and then maintained by the laser gyroscope unit (LGU), which is composed of three gyroscopes in the INS, when the vehicle travels along survey lines. Deflections of the vertical are calculated by using the difference between the attitudes with respect to the geodetic coordinates and astronomical coordinates. Moreover, an algorithm for removing the trend error of the vertical deflections is developed with the aid of Earth Gravitational Model 2008 (EGM2008). In comparison with traditional methods, the new method required less accurate GNSS, because the dynamic acceleration calculation is avoided. The errors of inertial sensors are well resolved in the INS/GNSS integration, which is implemented by a Rauch-Tung-Striebel (RTS) smoother. In addition, a single-axis indexed INS is adopted to improve the observability of the system errors and to restrain the inertial sensor errors. The proposed method is validated by Monte Carlo simulations. The results show that deflections of the vertical can achieve a precision of better than 1″ for a single survey line. The proposed method can be applied to a gravimetry system based on a ground vehicle or ship with a speed lower than 25 m/s.

16.
Ying Yong Sheng Tai Xue Bao ; 23(8): 2165-70, 2012 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-23189694

RESUMO

By the method of taking space instead of time, an incubation test was conducted to study the characteristics of soil mineralizable carbon pool during the natural restoration of Karst forest vegetation in Maolan Nature Reserve, Guizhou Province of Southwest China. It was observed that the contents of soil total organic carbon (TOC) and mineralizable carbon (MC) as well as the carbon mineralization rate decreased with increasing soil depth but increased with the process of vegetation restoration. The amount of cumulative released carbon and the carbon release rate increased with the process of restoration, but the release rate decreased with increasing incubation time. The soil MC/TOC increased with the restoration process but had less change with increasing soil depth, while the qCO2 decreased with increasing soil depth and through the process of restoration. The soil MC had a negative correlation with the existing litter amount (r = -0.796) but positive correlation with the mass loss rate of the litter decomposition (r = 0.924). Soil habitat changed from strong interference at early stages to relative stability at late stages, and soil carbon sequestration changed from small capacity and strong potential at early stages to large capacity and weak potential at late stages.


Assuntos
Carbono/análise , Conservação dos Recursos Naturais , Ecossistema , Solo/química , Árvores/crescimento & desenvolvimento , China , Compostos Orgânicos/análise
17.
Ying Yong Sheng Tai Xue Bao ; 23(11): 2961-7, 2012 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-23431776

RESUMO

Selecting the dominant tree species Quercus fabric in three root underground habitat types (the dolomites of low oblique occurrence with multilayer space, middle oblique occurrence with multilayer space, and high oblique occurrence with multilayer space) in Karst area as test object, this paper studied the foliar delta13C value and its correlations with habitat soil conditions, and the plant water use efficiency. There existed remarkable differences in the foliar delta13C value of Q. fabric among the three habitat types, being decreased in the order of low oblique occurrence with multilayer space type (-26.35 per thousand) > high oblique occurrence with multilayer space type (-26.66 per thousand) > middle oblique occurrence with multilayer space type (-27.07 per thousand). Accordingly, the plant water use efficiency decreased in the same order. The foliar delta13C value had significant correlation with habitat soil moisture content, but less correlation with habitat soil elements contents. The delta13C value increased with the decrease of soil moisture content and soil fertility.


Assuntos
Isótopos de Carbono/análise , Ecossistema , Quercus/crescimento & desenvolvimento , Solo/química , Altitude , Carbono/análise , China , Conservação dos Recursos Naturais , Raízes de Plantas/crescimento & desenvolvimento , Água/análise
18.
Ying Yong Sheng Tai Xue Bao ; 23(10): 2715-20, 2012 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-23359931

RESUMO

By the method of taking space instead of time, an incubation test was conducted to study the characteristics of soil microbial biomass carbon and water soluble organic carbon in the process of natural restoration of Karst forest in Maolan Nature Reserve, Guizhou Province of Southwest China. The soil microbial biomass carbon content and soil basal respiration decreased with increasing soil depth but increased with the process of the natural restoration, soil microbial quotient increased with increasing soil depth and with the process of restoration, and soil water soluble organic carbon content decreased with increasing soil depth. In the process of the natural restoration, surface soil water soluble organic carbon content increased, while sublayer soil water soluble organic carbon content decreased after an initial increase. The ratio of soil water soluble organic carbon to total soil organic carbon increased with increasing soil depth but decreased with the process of restoration. Soil quality increased with the process of restoration. Also, the quality and quantity of soil organic carbon increased with the process of restoration, in which, soil microbial biomass carbon content had the greatest change, while soil water soluble organic carbon content had less change.


Assuntos
Carbono/análise , Microbiologia do Solo , Solo/química , Árvores/crescimento & desenvolvimento , Água/análise , Biomassa , China , Conservação dos Recursos Naturais/métodos , Ecologia , Ecossistema , Recuperação e Remediação Ambiental/métodos , Compostos Orgânicos/análise , Solubilidade
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