Distributional Characteristics and Source Identification of Cadmium in Soils of the Pearl River Delta, China.

The results of the Multi-Purpose Geochemical Survey in the Pearl River Delta (PRD) show that the pollution is serious. In this study, the influence of geological genesis, soil-forming process, and human activities on soil quality in PRD is analyzed, and the influence factors, genesis and spatial distributional characteristics of cadmium (Cd) in different soil depths are studied by inverse distance weighted (IDW) and hot spot analysis. The results show that the spatial distribution of Cd is significantly different in PRD and high-value is mainly concentrated in the central cities of Guangzhou-Foshan-Jiangmen-Zhongshan-Zhuhai. Moreover, hot spots with higher Cd content in deep are mainly along Beijiang, Dongjiang, and Pearl River Estuary (PRE). Overall, our findings suggest that the high background value areas formed by marine-land and fluvial sediments as well as intensive human activities that make PRD become an area under the dual restriction of geological genesis and human activities, pollution control cannot be ignored.

Demand prediction and regulation zoning of urban-industrial land: Evidence from Beijing-Tianjin-Hebei Urban Agglomeration, China.

As a main type of urban construction land, urban-industrial land is used to provide the judging criteria for construction land scale in the planning period when urban population, industrial development, investment scale, and other conditions are uncertain in China; however, research on expected indicator such as urban-industrial land in overall land use plan mainly focuses on qualitative analysis; quantitative analysis research has not yet been carried out. Using MATLAB R2016a software modeling tools to establish GM (1, 1) model and RBF neural network model, respectively, this paper predicted the demand of urban-industrial land in Beijing-Tianjin-Hebei Urban Agglomeration. Comparing the predicated results with the actual value of urban-industrial land in Beijing, Tianjin, and 11 prefecture-level cities in Hebei Province, we determined the reasonable prediction model for urban-industrial land after testing the accuracy of the two prediction models. The results showed that the RBF neural network model was the more reasonable prediction model for urban-industrial land. Using the predicted results of the RBF neural network model, combining expected indicators of overall land use plan (2006-2020) in Beijing and Tianjin, as well as 11 prefecture-level cities in Hebei Province in the planning target year, determined remaining usable time of urban-industrial land. Finally, combined with the actual scale of urban-industrial land in 2015 and the predicated scale of urban-industrial land in 2020, the remaining usable time of each city's urban-industrial land was calculated in terms of the average annual growth rate of urban-industrial land from 2009 to 2015. According to the comparative relationship between the remaining usable time and the remaining time of the overall land use plan (5 years), urban-industrial lands were divided into three kinds of regulation zones: reasonable reduction zone, optimized adjustment zone, and core development zone. The policy implications for urban-industrial land in each regulation zone were also provided. This paper can provide reference for regulation zoning of urban-industrial land in developing countries and regions.

Multi-omics reveal the effects and regulatory mechanism of dietary neutral detergent fiber supplementation on carcass characteristics, amino acid profiles, and meat quality of finishing pigs.

This study aimed to reveal the effects and regulatory mechanism of dietary NDF on the performance of pigs by multi-omics analysis. Results showed that 16 % dietary NDF significantly improved meat quality, increased flavor amino acid content, and reduced backfat thickness and the feed-to-gain ratio. 16S rDNA sequencing showed that 16 % NDF significantly increased the abundance of Akkermansia, Lachnoclostridium, and Ruminococcus. Transcript analysis showed that genes related to muscle development and lipid metabolism were significantly modified. Metabonomic analysis showed that 16 % NDF significantly increased amino and fatty acid related metabolites. Correlation analysis suggested that 16 % NDF treatment may alter the gut microbiota and metabolites, regulate the expression of genes related to lipid and amino metabolism, and ultimately affect the flavor and performance of pigs. This study provides a novel understanding about the effect and regulatory mechanism of NDF supplements on the finishing pigs and a relevant reference for the improvement of diet formulation.

Noninvasive positron emission tomography imaging of cell death using a novel small-molecule probe, (18)F labeled bis(zinc(II)-dipicolylamine) complex.

The synthetic bis(zinc(II)-dipicolylamine) (DPAZn2) coordination complexes are known to have a high specific and selective affinity to target the exposed phosphatidylserine (PS) on the surface of dead and dying cells. An (18)F-labeled DPAZn2 complex (4-(18)F-Fluoro-benzoyl-bis(zinc(II)-dipicolylamine), (18)F-FB-DPAZn2) as positron emission tomography (PET) tracer was developed and evaluated for in vivo imaging of tumor treated with a chemical agent. The in vitro cell stain studies revealed that fluorescent DPAZn2 complexes (Dansyl-DPAZn2) stained the same cells (apoptotic and necrotic cells) as fluorescein isothiocyanate (FITC) labeled Annexin V (FITC-Annexin V). The radiosynthesis of (18)F-FB-DPAZn2 was achieved through the amidation the precursor bis(2,2'-dipicolylamine) derivative (DPA2) with the prosthetic group N-succinimidyl-4-[(18)F]-fluorobenzoate ((18)F-SFB) and chelation with zinc nitrate. In the biodistribution study, the fast clearance of (18)F-FB-DPAZn2 from blood and kidney was observed and high uptake in liver and intestine within 90 min postinjection was also found. For the PET imaging, significantly higher tumor uptake of (18)F-FB-DPAZn2 was observed in the adriamycin (ADM)-treated Hepa1-6 hepatocellular carcinoma-bearing mice than that in the untreated tumor-model mice, while a slightly decreased tumor uptake of (18)F-FDG was found in the ADM-treated tumor-bearing mice. The results indicate that (18)F-FB-DPAZn2 has the similar capability of apoptosis detection as FITC-Annexin V and seems to be a potential PET tracer for noninvasive evaluation and monitoring of anti-tumor chemotherapy. The high uptake of (18)F-FB-DPAZn2 in the abdomen needs to optimize the structure for improving its pharmacokinetics characteristics in the future work.

Analysis and prediction of carbon balance in production-living-ecological space of Henan Province, China.

As the carrier of human economic activities, the change of territorial space affects the level of regional carbon balance. Therefore, with regional carbon balance as the goal, this paper proposed a framework from the perspective of production-living-ecological space and took Henan Province of China as a study area for empirical research. First, the study area established an accounting inventory that considers nature, society, and economic activities to calculate carbon sequestration/emission. Then, the spatiotemporal pattern of carbon balance was analyzed by ArcGIS from 1995 to 2015. Later, the CA-MCE-Markov model was used to simulate the production-living-ecological space pattern in 2035, and carbon balance in three future scenarios was predicted. The study showed that from 1995 to 2015, the living space gradually expanded, and the aggregation rose while the production space decreased. Carbon sequestration (CS) was less than carbon emission (CE) and presented an unbalanced state of negative income in 1995, while CS exceeded CE and showed a positive income imbalance in 2015. In 2035, living space has the highest carbon emission capacity under natural change scenario (NC), while ecological space has the highest carbon sequestration capacity under ecological protection scenario (EP), and production space has the highest carbon sequestration capacity under food security scenario (FS). The results are crucial for understanding the carbon balance changes in territorial space and supporting regional carbon balance goals in the future.

A comparative uptake study of multiplexed PET tracers in mice with turpentine-induced inflammation.

The potential value of multiplexed positron emission tomography (PET) tracers in mice with turpentine-induced inflammation was evaluated and compared with 2-[¹8F]fluoro-2-deoxy-D-glucose ([¹8F]FDG) for glucose metabolism imaging. These PET tracers included [¹8F]fluoromethylcholine ([¹8F]FCH) for choline metabolism imaging, (S-[¹¹C]methyl)-D-cysteine ([¹¹C]DMCYS) for amino acid metabolism imaging, [¹¹C]bis(zinc(II)-dipicolylamine) ([¹¹C]DPA-Zn²âº) for apoptosis imaging, 2-(4-N-[¹¹C]-methylaminophenyl)-6-hydroxybenzothiazole ([¹¹C]PIB) for ß amyloid binding imaging, and [¹8F]fluoride (¹8F⁻) for bone metabolism imaging. In mice with turpentine-induced inflammation mice, the biodistribution of all the tracers mentioned above at 5, 15, 30, 45, and 60 min postinjection was determined. Also, the time-course curves of the tracer uptake ratios for inflammatory thigh muscle (IM) to normal uninflammatory thigh muscle (NM), IM to blood (BL), IM to brain (BR), and IM to liver (LI) were acquired, respectively. Moreover, PET imaging with the tracers within 60 min postinjection on a clinical PET/CT scanner was also conducted. [¹8F]FDG and ¹8F⁻ showed relatively higher uptake ratios for IM to NM, IM to BL, IM to BR, and IM to LI than [¹8F]FCH, [¹¹C]DPA-Zn²âº, [¹¹C]DMCYS and [¹¹C]PIB, which were highly consistent with the results delineated in PET images. The results demonstrate that ¹8F⁻ seems to be a potential PET tracer for inflammation imaging. [¹8F]FCH and [¹¹C]DMCYS, with lower accumulation in inflammatory tissue than [¹8F]FDG, are not good PET tracers for inflammation imaging. As a promising inflammatory tracer, the chemical structure of [¹¹C]DPA-Zn²âº needs to be further optimized.

Spatio-Temporal Variation and Its Driving Forces of Soil Organic Carbon along an Urban-Rural Gradient: A Case Study of Beijing.

Rapid urbanization has reshaped land cover and the ecological environment, potentially improving or deteriorating soil organic carbon (SOC). However, the response of SOC to urbanization has not yet been fully exploited. Herein, by using the land-use transfer matrix, the Sen & Mann-Kendall tests, the Hurst index, and a geographical and temporal weighted regression (GTWR) model, as well as an urban-rural gradient perspective, we assessed the dynamic response of SOC to Beijing's urbanization from 2001 to2015 and identified the main drivers. The results found that SOC stock decreased by 7651.50 t C during the study period. SOC density varied significantly along an urban-rural gradient, with high value areas mainly being located in remote mountainous rural areas and low value areas mainly being located in urban areas on the plains. There was an uneven variation in SOC density across the urban-rural gradient, with suburban areas (25-40 km away from urban cores) losing the most SOC density while urban areas and rural areas remained relatively unchanged. GTWR model revealed the spatio-temporal non-flat stability of various driving forces. Precipitation, the proportion of forest, the proportion of grassland, the population, distance to the urban center, the slope, and the silt content are the main factors related to SOC stock change. As a result, we suggest policy makers reconceptualize the uneven variation in the SOC between urban and rural areas, emphasize suburban areas as a target for controlling SOC loss, and take into consideration the spatial and temporal heterogeneity of the factors influencing SOC stock when evaluating policies.

Significant loss of soil inorganic carbon at the continental scale.

Widespread soil acidification due to atmospheric acid deposition and agricultural fertilization may greatly accelerate soil carbonate dissolution and CO2 release. However, to date, few studies have addressed these processes. Here, we use meta-analysis and nationwide-survey datasets to investigate changes in soil inorganic carbon (SIC) stocks in China. We observe an overall decrease in SIC stocks in topsoil (0-30 cm) (11.33 g C m-2 yr-1) from the 1980s to the 2010s. Total SIC stocks have decreased by ∼8.99 ± 2.24% (1.37 ± 0.37 Pg C). The average SIC losses across China (0.046 Pg C yr-1) and in cropland (0.016 Pg C yr-1) account for ∼17.6%-24.0% of the terrestrial C sink and 57.1% of the soil organic carbon sink in cropland, respectively. Nitrogen deposition and climate change have profound influences on SIC cycling. We estimate that ∼19.12%-19.47% of SIC stocks will be further lost by 2100. The consumption of SIC may offset a large portion of global efforts aimed at ecosystem carbon sequestration, which emphasizes the importance of achieving a better understanding of the indirect coupling mechanisms of nitrogen and carbon cycling and of effective countermeasures to minimize SIC loss.

Land-use zoning management to protecting the Regional Key Ecosystem Services: A case study in the city belt along the Chaobai River, China.

There are complex tradeoffs and synergies between ecosystem services. At the regional scale, some ecosystem services play a more critical role in regional ecological security and social development. Therefore, it is necessary to identify key ecosystem services and prioritize their protection and management to ensure their sustainable and effective delivery in a region. This paper proposes a set of research schemes that comprehensively examine the supply, trade-off, and demand of ecosystem services, using the city belt along the Chaobai River in north China as an example for empirical research. Demarcating a 1 km × 1 km area, we first analyze the spatial-temporal supply patterns of Net Primary Productivity (NPP), Water Yield (WY), Soil Retention (SR), Sand Retention (SAR), and Habitat Quality (HQ) from 2010 to 2015 using the CASA, InVEST, USLE, RWEQ and InVEST models, respectively. Thereafter, we define the Regional Key Ecosystem Service (RKES) through regional reality and Spearman correlation analysis among the five ecosystem services. Finally, based on the disparity between the supply and demand of the RKES, we develop a land zoning approach and propose targeted zoning management measures. The results show that WY was the RKES in the study area. The demand for WY did not exceed supply, and the supply and demand were always in a state of mismatch. The stable area with surplus supply and demand of WY was designated as an Ecological Protected Area, a core area to guarantee the RKES. In general, our scheme can be targeted to address the protection of RKES from the perspective of land management. This is of great significance for ensuring regional ecological security and sustainable use of ecosystem services, and could be used to inform the formulation of ecological protection policies.

Dataset of ecosystem services in Beijing and its surrounding areas.

This data article describes the multiple ecosystem services in Beijing and surrounding areas, including grain providing, water yield, carbon sequestration, soil retention, purified water service, cultural services, and habitat quality. These data are mainly from public data sets such as the Harmonized World Soil Database. These data can be used to improve the optimization of human well-being in the social-ecological system and further achieve regional sustainable development.

Identification of ecosystem service bundles and driving factors in Beijing and its surrounding areas.

In high-intensity human activity areas, such as metropolises, rapid changes in land use, agricultural intensification, and population urbanization have resulted in profound and complex transformations in socio-economic ecosystems. The study of ecosystem service (ES) bundle is conducive to various aspects, such as determination of the variation characteristics of ES; identification of the mechanism of interdependence within ES; and driving mechanism of socio-economic-ecological factors to ES to maintain the sustainable development of the region. The research areas include Beijing and its surrounding areas. Ten ES, including grain providing (GP), water yield (WY), carbon sequestration (CS), soil retention (SEC), purified water service, cultural services, and habitat quality (HQ) were selected for valuing and mapping. The ES paired trade-offs and synergetic relationship, bundle was determined, and the bundles' service types and spatial distribution characteristics were analyzed. Subsequently, GeoDetector was used for detecting the factors affecting the bundles' distribution. Results showed that WY, CS, SEC, and HQ were bounded by Tai-hang and Yanshan Mountains. Among the 45 pairs of ES, 38 pairs bore significant correlation. Multiple services had different degrees of positive and negative correlations with other services. For example, GP had a high positive correlation with WY while bearing a high negative correlation with HQ. Seven bundles include SEC, culture, urban, HQ, agriculture, water supply and purification, and water purification. Various factors played decisive roles in the bundles' spatial distribution. Among them, the investment capacity and demand for ecological protection depend on the level of GDP and POP. The formulation of agricultural planting plans is inseparable from TADEM. ASL is directly related to species richness. Results indicate that bundle research can identify the areas of the formation of co-occurrence of trade-offs and synergies and support the formulation of ES optimal management plans for different regions through further research of the driving mechanism.

Evaluation of heavy metal distribution characteristics of agricultural soil-rice system in a high geological background area according to the influence index of comprehensive quality (IICQ).

Heavy metal pollution is a global ecological safety issue, especially in crops, where it directly threatens regional ecological security and human health. Selecting scientific evaluation methods is an important prerequisite for understanding the distribution of heavy metals in a region. To evaluate the distribution characteristics of arsenic (As), cadmium (Cd), copper (Cu), and zinc (Zn) in farmland soil-rice system in Doumen District of Zhuhai City, Pearl River Delta, we analyzed the high geological background area and heavy metal contents in soil by inverse distance-weighted interpolation and single-factor pollution index. Bioconcentration factor (BCF) was used to study the migration and accumulation characteristics of heavy metals. Then, the soil-rice system was evaluated comprehensively with a novel evaluation method, i.e., the influence index of comprehensive quality (IICQ). Results showed that As, Cd, Cu, and Zn in the soil of the study area followed normal distribution. Cd and Cu were the main pollutants whose point contamination rates were 50% and 22.86%, respectively. A total of 2.86% of the soil were contaminated by As, and no Zn contamination was observed in the soil. At the same time, As and Cd in rice were partially polluted, and the Cu and Zn were not polluted. The order of bioaccumulation coefficient was Cd > Zn > Cu > As, and no evident enrichment was observed. According to the impact index of IICQ to evaluate the pollution of heavy metals in the soil-rice system, 96.98% of the soil in study area was in a state of moderate, heavy, and extreme pollution, which were concentrated in the northern and central parts of the study area. The soil-rice system in the high geological background area was in a subhealthy state. A total of 90.69% of the soil were polluted, but the rice met the national food safety standards.

Can the establishment of ecological security patterns improve ecological protection? An example of Nanchang, China.

Establishing ecological security patterns provides new ideas for maintaining regional ecological security. Methods for establishing these patterns have been extensively investigated in several studies, but the ecological protection effects of these patterns need further examination. Nanchang is the capital city of Jiangxi province and a typical representative of rapidly developing cities. With the proposal of an ecological environment protection plan for Nanchang metropolitan area, the coordinated development of ecology, economy and society has become the local development goal. This study used Nanchang City as an example for the establishment of an ecological security pattern through the circuit theory. The ecological sources of a 1068.56 km2 location and 20 ecological corridors with a total area of 957.39 km2 were identified. Three development scenarios in 2015-2040 were set up, namely, unrestricted development (UD), core area protection (CP) and ecological security pattern restriction (ESPR) scenarios. The UD scenario followed the land expansion rate from 2010 to 2015. The CP scenario used a nature reserve as a forbidden conversion area. Under the ESPR scenario, ecological security pattern was regarded as a prohibited conversion area. The CLUMondo model was used in simulating land use and evaluating the ecological protection effects of the scenarios. Through comparison, we determined that the ecological security indices under UD, CP and ESPR were 0.230, 0.242 and 0.249, respectively, from the perspective of the overall ecological security of the region. In the evaluation of the landscape characteristics of EL, under ESPR, the landscape connectivity was the best. The detailed analysis results showed that the ecological security pattern not only could protect the regional ecological security on the regional scale but also had an outstanding protection effect on the local scale. In summary, compared with the UD and CP scenarios, ecological security patterns had a better effect on regional ecological protection.

Effects of hydrogen-peroxide supply rate on schwertmannite microstructure and chromium(VI) adsorption performance.

Schwertmannite has attracted increasing interest for its excellent sorption for pollutants such as arsenite [As(III)] and arsenate [As(V)]. Limited studies were conducted with hexavalent chromium [Cr(VI)], especially for schwertmannite synthesized through Fe2+ oxidation. The effect of the hydrogen-peroxide (H2O2) supply rate on the structural characteristics and Cr(VI) adsorption capacity of schwertmannite is unclear. The morphology, crystallinity, specific surface area (SSA), pore volume and Cr(VI) adsorption of schwertmannite through Fe2+ oxidation at different H2O2 supply rates were analyzed. A slow H2O2 supply could improve the schwertmannite SSA and pore volume. Schwertmannite changed from nanoparticle aggregates (169.31 m2/g SSA, 0.20 cm3/g pore volume) to ball-with-whisker-shaped particles (228.75 m2/g SSA, 0.30 cm3/g pore volume) with a lower H2O2 supply rate. The Cr(VI) adsorption capacity increased by 6.25%-11.70% at different given Cr(VI) concentrations. The maximum Cr(VI) adsorption capacity of schwertmannite was 1.89 mmol/g at pH 6.0. Cr(VI) adsorption onto schwertmannite may be attributed mainly to ion exchange with the structural SO42-. More than 91% of the original Cr(VI) adsorption capacity was maintained after four recycles. This study provides novel insights into the effects of H2O2 supply rate on the microstructure of schwertmannite and its adsorption capacity for Cr(VI) in aqueous medium.

Correction to: A bibliometric analysis of research on haze during 2000-2016.

The original version of this article unfortunately contains mistakes.

A bibliometric analysis of research on haze during 2000-2016.

As one of the bibliometric analysis tools, CiteSpace software was applied to quantitatively and visually evaluate global scientific documents of research on haze from 2000 to 2016. Five thousand six hundred six documents from the Science Citation Index Expanded (SCI-Expanded) and Social Science Citation Index (SSCI) of the Web of Science database were statistically analyzed and examined. The distributions on authorship, countries/territories, institutes, and keywords were generated. The amount of publications has increased nearly for the past 17 years. The most productive author was Li J. with 46 articles. The publications on haze research were primarily originated from the USA, China, Germany, and France. By synthetically analyzing the keywords, the dominant hot spots of haze research could be concluded as "aerosol," "atmosphere," "particle," "PM2.5,"and "air quality."

Efficient preparation of [11C]CH3Br for the labeling of [11C]CH3-containing tracers in positron emission tomography clinical practice.

BACKGROUND AND AIM: [C]methyl iodide ([C]CH3I) is the most extensively used methylation agent for the preparation of a majority of C-labeled positron emission tomography (PET) radiotracers, which is commonly produced by the wet method and the gas-phase method. On account of the complexity of the gas-phase method, a simple automated synthesis of [C]methyl bromide ([C]CH3Br) as an analog of [C]CH3I is derived by the wet method in this study. Radiosynthesis of L-[S-methyl-C]methionine (MET), L-[S-methyl-C]cysteine (MCYS), [N-methyl-C]choline (CH), [C]methyl triflate ([C]CH3OSO2CF3), and [C]-2-ß-carbomethoxy-3-ß-(4-fluorophenyl)-tropane (CFT) by methylation reaction with [C]CH3Br, and PET imaging of patients are also described. METHODS: The preparation of [C]CH3Br by a one-pot wet method involved the following steps: reduction of [C]carbon dioxide with lithium aluminium hydride (LiAlH4) solution, treatment with hydrobromic acid, and distillation of [C]CH3Br under continuous nitrogen flow. [C]methylation of L-homocysteine thiolactone hydrochloride, L-cysteine, 2-dimethylaminoethanol, silver triflate, and nor-ß-CFT as precursors with [C]CH3Br and purification with Sep-Pak cartridges gave MET, MCYS, CH, [C]CH3OSO2CF3, and CFT, respectively. In addition, PET imaging of brain cancer and Parkinson's disease was carried out. RESULTS: The uncorrected radiochemical yield of [C]CH3Br was (37.8±2.5%) based on [C]carbon dioxide within a total synthesis time of 10 min and the radiochemical purity of [C]CH3Br was greater than 95%. The uncorrected yields of MET, MCYS, CH, [C]CH3OSO2CF3, and CFT were 70.1±0.5%, 70.2±2.3%, 60.3±1.8%, 95.1±2.2%, and 60.1±1.5% (from [C]CH3OSO2CF3) within a total synthesis time of 2, 2, 5, 1, and 8 min, respectively. The radiochemical purity of MET, MCYS, CH, [C]CH3OSO2CF3, and CFT was more than 95%. Good PET images in the patients are obtained. CONCLUSION: Automated synthesis of [C]CH3Br can be done by the wet method on the commercial [C]CH3I synthesizer. [C]CH3Br can be used for a [C]methylation reaction to produce C-labeled tracers for clinical PET imaging.

S-11C-methyl-L-cysteine: a new amino acid PET tracer for cancer imaging.

UNLABELLED: S-(11)C-methyl-L-cysteine ((11)C-MCYS), an analog of S-(11)C-methyl-L-methionine ((11)C-MET), can potentially serve as an amino acid PET tracer for tumor imaging. The aim of this study was to investigate the radiosynthesis and perform a biologic evaluation of (11)C-MCYS as a tumor imaging tracer. The results of the first human PET study are reported. METHODS: (11)C-MCYS was prepared by (11)C-methylation of the precursor L-cysteine with (11)CH(3)I and purification on commercial C18 cartridges. In vitro competitive inhibition experiments were performed with Hepa1-6 hepatoma cell lines, and biodistribution of (11)C-MCYS was determined in normal mice. The incorporation of (11)C-MCYS into tissue proteins was investigated. In vivo (11)C-MCYS uptake studies were performed on hepatocellular carcinoma-bearing nude mice and inflammation models and compared with (11)C-MET PET and (18)F-FDG PET. In a human PET study, a patient with a recurrence of glioma after surgery was examined with (11)C-MCYS PET and (18)F-FDG PET. RESULTS: The uncorrected radiochemical yield of (11)C-MCYS from (11)CH(3)I was more than 50% with a synthesis time of 2 min, the radiochemical purity of (11)C-MCYS was more than 99%, and the enantiomeric purity was more than 90%. In vitro studies showed that (11)C-MCYS transport was mediated through transport system L. Biodistribution studies demonstrated high uptake of (11)C-MCYS in the liver, stomach wall, and heart and low uptake of (11)C-MCYS in the brain. There was higher accumulation of (11)C-MCYS in the tumor than in the muscles. The tumor-to-muscle and inflammatory lesion-to-muscle ratios were 7.27 and 1.62, respectively, for (11)C-MCYS, 5.08 and 3.88, respectively, for (18)F-FDG, and 4.26 and 2.28, respectively, for (11)C-MET at 60 min after injection. Almost no (11)C-MCYS was incorporated into proteins. For the patient PET study, high uptake of (11)C-MCYS with true-positive results, but low uptake of (18)F-FDG with false-negative results, was found in the recurrent glioma. CONCLUSION: Automated synthesis of (11)C-MCYS is easy to perform. (11)C-MCYS is superior to (11)C-MET and (18)F-FDG in the differentiation of tumor from inflammation and seems to have potential as an oncologic PET tracer for the diagnosis of solid tumors.

[Soil organic carbon storage and its spatial distribution in Henan Province].

By using 1: 200 000 soil database, the soil organic carbon storage in Henan Province was estimated, and its spatial distribution was analyzed. The results showed that in this province, soil organic carbon storage was about 10.27 x 10(8) t, accounting for 1.15% of the total in China, and its density was 7.46 kg m(-2) on average, being lower than that (9.60 kg m(-2)) in this country. The top four soil types in organic carbon storage were fluvo-aquic soil, cinnamon soil, skeletal soil, and yellow cinnamon soil, with the storage all being higher than 1.0 x 10(8) t and totally taken up 69.65% of that in Henan. The organic carbon density was the highest in bog soil (24.54 kg m(-2)), followed by in mountain meadow soil (17.69 kg m(-2)) and brown soil (14.64 kg m(-2)). These three soil types mainly distributed in the mountainous areas of west Henan, and the sum of their organic carbon storage was only accounted for 6.34% of the total in the province. The organic carbon density was the lowest in rocky soil (1.32 kg m(-2)) and aeolian sandy soil (1.38 kg m(-2)). In general, the density of soil organic carbon in Henan province mostly varied from 5 kg m(-2) to 10 kg m(-2).