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Xiaochuan Zhang,1,2,&ast; Fajin Lv,1,&ast; Binjie Fu,1 Wangjia Li,1 Ruiyu Lin,1 Zhigang Chu1 1Department of Radiology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, 400016, People’s Republic of China; 2Department of Radiology, Chonggang General Hospital, Chongqing, 400080, People’s Republic of China&ast;These authors contributed equally to this workCorrespondence: Zhigang Chu, Tel +86 18723032809, Fax +86 23 68811487, Email chuzg0815@163.comPurpose: To investigate the clinical and computed tomography (CT) characteristics of peripheral small-cell lung cancer (pSCLC) to improve its early diagnosis.Patients and Methods: In total, 70, 132, 69, and 95 patients with pathological confirmed nodular (≤ 3 cm) pSCLC, peripheral non-small cell lung cancer (pNSCLC), benign lung tumor (pBLT), and inflammatory lesion (pIL) were enrolled in this study retrospectively. The clinical and CT data of studied patients with different lesions were analyzed and compared by univariate analysis. Multivariate analysis was used to reveal the key features to distinguish pSCLC from pNSCLC, pBLT, and pIL, respectively.Results: Univariate and multivariate analysis of the clinical and CT characteristics of studied patients indicated that 1) compared with pNSCLC and pIL, vessel convergence, spiculation, and peripheral ground-glass opacity were less common in pSCLC; 2) density homogeneity (OR = 38.84– 120.21, P < 0.05), bronchial cutoff sign (OR = 10.00– 60.13, P = 0.001), hilar lymph node enlargement (OR = 22.81– 95.08, P < 0.0001) (pSCLC vs pNSCLC, pBLT, and pIL), male sex (OR = 5.53– 10.92, P < 0.05) (pSCLC vs pNSCLC and pBLT), and emphysema (OR = 36.57– 56.63, P < 0.05) (pSCLC vs pBLT and pIL) were significantly and independently associated with pSCLC. Type I and II bronchial cutoff sign, especially type I, were closely related to pSCLC.Conclusion: Peripheral solid nodules with homogeneous density, bronchial cutoff sign, hilar lymph node enlargement, but without spiculation or vessel convergence in male patients with emphysema should be highly suspected of pSCLC.Keywords: small-cell lung carcinoma, non-small cell lung carcinoma, tomography, X-ray computed

In this study, we intercropped hyperaccumulator Perilla frutescens with soybean to explore the effects of intercropping under cadmium stress based on the physiological growth indexes of plant, cadmium absorption capacity, and soil cadmium forms Experiments showed that compared with mono-cropping, intercropping soybean’s biomass, catalase (CAT) activity, peroxidase (POD) activity, total chlorophyll and net photosynthetic rate were significantly increased by 1042%~10658%, 1578%~7381%, 1345%~2337%, 376%~1500% and 7121%~31278%, while P frutescens’s significantly decreased by 9387%~9507%, 1562%~2572%, 12056%~15331%, 715%~756% and 3056%~5076% Under 5 and 10 mg kg-1 Cd treatments, the Cd content in roots, stems, leaves, pods and grains of intercropping soybean decreased significantly by 1072%~3174%, 1488%~2168%, 1995%~3413%, 2222%~5270% and 791%~1786% along with enrichment coefficient decreasing by 1486%~2787%, while those of P frutescens significantly increased by 8700%~2141%, 948%~2155%, 2305%~3766% and 1818%~9412% along with enrichment coefficient significantly increasing by 2000%~7775% Additionally, citric acid, succinic acid, oxalic acid and tartaric acid worked importantly in heavy metal detoxification in plants Strikingly, the content of soil exchangeable Cd (EXC) under intercropping was the highest, even higher than that of mono-cropping soybean and P frutescens, which accounted for 37%~42% under the same stress condition Therefore, intercropping Perilla frutescens with soybean provide a potential strategy for Cd phytoremediation

Cadmium (Cd) pollution of paddy soils is one of the main concerns causing food security and environmental problems. Microbial bioremediation is an effective and eco-friendly measure that uses microbes to reduce Cd accumulation in crops. Additionally, rhizosphere bacterial communities also act essential roles in crop tolerance of heavy metals. However, the effects of inoculations with Cd resistant bacteria on crop rhizosphere bacterial communities under Cd exposure are largely unknown. In this study, we used high-throughput 16S rRNA gene sequencing technologies to explore the community structure and co-occurrence network of the rhizosphere bacterial communities associated with the rice crop under different Cd treatments and the application of Cd-tolerant strain Pseudomonas sp. TCd-1. We found that the strain TCd-1 both significantly reduced the rhizobacterial alpha diversity and changed the beta diversity. PERMANOVA and NMDS analysis showed that Cd stress and TCd-1 strain could act as strong environmental filters resulting in observable differentiation of rhizobacterial community composition among different groups. In addition, RDA results indicated that the rhizosphere pH, root Cd content, catalase (CAT), urease (URE), gibberellic acid (GA3) exert significant association with rhizosphere bacterial assembly. PICRUSt analysis revealed that the TCd-1 strain improved the metabolic capacity of rhizosphere bacteria under Cd stress. Furthermore, co-occurrence network topological features and keystone taxa also varied among different groups. This study could provide necessary insights into developing an efficient bioremediation and safe production of rice crops in Cd contaminated paddy fields with the application of Pseudomonas sp. TCd-1 strain, as well as advance our understanding of the principles of rhizosphere bacterial community assembly under Cd stress.

Recently, rice contamination by heavy metals (HMs) has become a severe problem. Taking the Western Fujian region as an example in this study, a total of 1311 rice samples containing eight HMs were collected from 2015 to 2019, then used to explore their pollution characteristics, health risks, and Spatio-temporal variations, finally derive the target remediation areas of the key pollutants. The results showed that average concentrations of all the HMs had not reached the limits of the National Standards of Food Safety, but pollution indexes of As (0.783) and Cu (0.665) were at accumulation level (>0.6), which posed high pollution risks. Furthermore, locations of higher HMs concentrations coincided with those of higher pollution estimation probabilities. The non-carcinogenic risk (4.150, 2.434) and carcinogenic risk (4.96 × 10−3, 2.92 × 10−3) for children and adults cannot be negligible, As and Cd were the largest contributors. Children were more susceptible than adults due to the metal concentrations and rice intake rate. The spatio-temporal changes indicated that a decreasing trend in average concentrations of HMs (except Cr), but As (0.37%−0.88%) contents increased in the west and northeast parts, and so did Cd (1.92%−5.11%) in the central region during monitoring. For the target remediation, particular regions in the western and eastern were used as risky areas of As and Cd, respectively. Our results will provide theoretical support for the pollution management of HMs in rice.

Chiral mesoporous silica ribbons and rods with inversed handedness have been synthesized with the same enantio pure N-acylaminoacidat temperatures of 0 °C and 20 °C, respectively. With involving Cu2+ and meso-tetra(4-sulfonatophenyl)porphyrin (TPPS) as probes, ribbons and rods revealed opposite signals in diffuse-reflectance circular dichroism (DRCD) spectra, indicating the existence of inversed supramolecular chiral imprintings through helical stacking of amphiphiles. The structural evolution was systematically studied by the freeze-dried products sampled at different time after the addition of silica precursors. The H-bonding-depended molecular orientation probably controls the chiral sense upon forming chiral molecular stacking, which would be the origin of such handedness inversion phenomenon

Microbial remediation is a promising technique to reduce Cd accumulation in rice (Oryza sativa). In present study, a set of pot experiments were conducted to evaluate the effects of Cd-tolerate Pseudomonas TCd-1 inoculation on rice Cd uptake, soil enzyme activities and Cd bioavailability in the rhizosphere soils under Cd contaminated conditions. The results showed that at the ripening stage, with the inoculation of TCd-1, Cd contents in root, culm, leaf, hull and brown rice significantly reduced by 60.7%, 47.7%, 50.6%, 58.1% and 47.9%, respectively, and the cadmium bioconcentration factor (BCF) of rice lowered by 66.2% under 5 mg kg−1 Cd treatment. At the meantime, in the rhizosphere soils, pH increased by 0.05, the contents of exchangeable Cd (EX-Cd) and Fe-Mn oxides (OX-Cd) increased by 107.8% and 33.5%, whereas organic matter (OM-Cd) and residual (Res-Cd) decreased by 31.9% and 60.0%, respectively. The activity of acid phosphatase (ACP) increased by 28.3%, catalase (CAT), saccharase (SUC) activity decreased by 28.5% and 26.0%. Similarly, the Cd contents in root, culm, leaf, hull and brown rice reduced by 42.1%, 42.5%, 58.0%, 50.3%, and 68.8%, respectively, and the BCF lowered by 57.1%, under 10 mg kg−1 Cd treatment. Simultaneously, the soil pH increased by 0.06, the activities of CAT, SUC, urease (URE), ACP decreased by 26.4%, 34.6%, 63.8% and 15.3%, respectively. Furthermore, the correlation analysis showed that the inoculation of TCd-1 changed the correlation between rice Cd content and the biomass of roots, leaves, soil pH, CAT, PPO, URE activities, OM-Cd in rhizosphere soils. It suggested that Pseudomonas TCd-1 effectively reduced Cd uptake and Cd accumulation in rice was closely linked to the changes of soil pH, enzyme activities and Cd availability.

High specific surface area activated carbon prepared by Perilla frutescens (PFHSAAC) was modified on the surface of the glassy carbon electrode (GCE) by drop-coating method to construct a PFHSAAC/GCE. The electrochemical properties of the modified electrode were investigated in detail by some electrochemical methods such as cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS). Experiment results show that the modified electrode has excellent redox activity and distinction capability toward the two isomers of catechol (CC) and hydroquinone (HQ). The separation of oxidation peak potential for HQ and CC of DPV is 112.8 mV. Under the optimal conditions, the oxidation peak currents of HQ and CC show good linear relationships with their concentrations in the ranges of 1.0 × 10-6-2.0 × 10-4 and 1.0 × 10-6-1.5 × 10-4 mol L-1, respectively. The limits of detection for HQ and CC are 3.57 × 10-7 and 4.23 × 10-7 mol L-1, respectively. The PFHSAAC/GCE exhibits good stability, repeatability and sensitivity. The developed method was used to determine HQ and CC in water samples with best results.

Screening new accumulators of heavy metal and identifying their tolerance, enrichment capacity of heavy metals are currently hot issues in phytoremediation research. A series of hydroponic experiments were conducted to analyze the effects of glutathione and phytochelatins in roots, stems, and leaves of Perilla frutescens under cadmium stress. The results showed that the non-protein thiols in roots and stems mainly existed in the form of GSH, PC2, PC3, and PC4 under Cd stress condition, while in leaves they existed in the form of GSH, PC2, and PC3. Furthermore, the contents of GSH and PCs positively correlated with Cd, but negatively correlated with root vigor and chlorophyll content under Cd stress conditions. After 21 days of treatments, the contents of Cd in different parts of the plant were 1465.2–3092.9 mg· kg−1 in the roots, 199.6–478.4 mg·kg−1 in the stems and 61.3–96.9 mg· kg−1 in the leaves at 2, 5, 10 mg·L−1 Cd levels respectively, and the amount of Cd uptakes were up to 3547.7–5701.7 μg·plant−1. Therefore, P. frutescens performed high capacity in Cd accumulation, and PCs played a key role in Cd tolerance. The application prospect of the plant in phytoremediation Cd polluted soil was also discussed.

Reduction of ammonia (NH3) emission in agricultural systems is highly important from agronomic, ecologic, and economic standpoints. We studied NH3 volatilization from surface applied urea and SuperU® (urea containing urease and nitrification inhibitors) and its interaction with tillage system (conventional tillage and no-tillage) in a dryland arable soil. Agronomic efficiency of the fertilizers was also assessed by measuring yield, agronomic N-efficiency, and apparent N-use of camelina (Camelina sativa L.). Results indicated significant variation between the field and laboratory experiments. Due to wet spell around the time of fertilization, cumulative volatilization was significantly lower in the field study. NH3 emission associated with SuperU in the field study was about 45% lower than regular urea, which was attributed to a) activity of urease inhibitor delayed SuperU hydrolysis for about five days and b) a rainfall occurred four days after fertilization that likely carried more fertilizer into the soil from SuperU than urea. In the incubation study, NH3 loss was notable and superiority of SuperU was not seen. The results suggest that just replacing urea with SuperU would not result in mitigation of NH3 emission, but it provides a greater chance for N to enter the soil by one way or another (rainfall in our study). Our results did not show any appreciable interaction between N fertilizers and tillage systems. Application of SuperU in the first year of the study resulted in a significantly higher camelina yield and agronomic N-efficiency, but in the second year, due to unfavorable environmental condition, camelina did not grow well thus did not respond positively to N fertilization. The superiority of SuperU over urea in terms of NH3 volatilization and agronomic efficiency may be achieved if farmers apply the fertilizer timely in accordance with weather conditions.

A simple and practical sensor of hydrogen peroxide (H2O2) was designed successfully. The mixture of horseradish peroxidase (HRP) and chitosan (Chit) are effectively immobilized on the surface of poly-L-leucine/polydopamine modified glassy carbon electrode (PL-LEU/PDA/GCE). Under the optimum conditions, the biosensor based on HRP exhibits a fast amperometric response (within 3 s) to H2O2. The linear response range of the sensor is 0.5–952.0 μmol L–1, with the detection limit of 0.1 μmol L–1 (S/N = 3) and the sensitivity of 0.23 A L moL–1 cm–2. The apparent Michaelis–Menten constant (k M app) of the biosensor is evaluated to be 0.12 mmol L–1, which suggests that the HRP-Chit/PL-LEU/PDA/GCE shows a higher affinity for H2O2. The sensor exhibits good sensitivity, selectivity, stability and reproducibility. The proposed method has been successfully applied to the determination of H2O2 in practical samples.

The potential threats of heavy metals in rice have attracted increasing attention worldwide. In this study, we assessed the pollution status and health risk of rice collected from Longyan in Fujian, China. Meanwhile, we explored the spatial pattern and hotspots of those metals. The results showed that the average concentrations of Cd, Hg, As, Pb, Cr, Ni, Cu, and Zn in rice were 0.064, 0.002, 0.464, 0.072, 0.138, 0.106, 10.819, and 23.788 mg kg−1, respectively. Among them, As and Cu remarkably accumulated with the exceeding ratio of 50.30% and 55.12%, respectively. Furthermore, the values of the target hazard quotient in rice ranked as As > Cu > Zn > Cd > Pd > Ni > Hg > Cr, which As and Cu was greater than 1.0. And the carcinogenic risk values were in the order of As > Cd > Ni > Cr, which all exceeded the tolerance level (1 × 10−4). Risk assessment indicated that both children and adults were posed the non-carcinogenic and carcinogenic risk from rice intake, and As had the largest contribution rate for them. Comparison found that the spatial patterns of heavy metals distribution were consistent with the hotspots. The hotspots for As and Zn located in the western part (Changting and Wuping), Cd and Cu in the eastern part (Xinluo and Yongding), Cr and Ni were simultaneously found in the northeast (Zhangping), while Hg and Pb were mainly located in the central region (Shanghang). Overall, combining the pollution status, risk assessment, and hotspot distribution in rice, the western region (Changting and Wuping) were identified as priority areas for remediation.

Cadmium (Cd) pollution is one of the major concerns in the development of sustainable agriculture, particularly for rice production. Silicon (Si) was recently recognized for its ability to mitigate a variety of abiotic stresses including that caused by Cd on rice. However, mechanism of the complex process is still not fully understood. Under Cd-stress, the low Si-influx 1-RNAi transgenic Lemont rice (Lsi1-RNAi line) exhibited an increased Cd-uptake over its counterparts, the wild type and the Lsi1-overexpression transgenic rice (Lsi1-OE line). In contrast, the Lsi1 expression-enhanced Lsi1-OE line showed the greatest Si-uptake among the three lines, with the highest activities on anti-oxidants (such as, superoxide dismutase) and the lowest content of malondialdehyde. Lsi1 also displayed a negative regulation on Low Cd gene and the natural resistance-associated macrophage proteins, Nramp5, indicating its capacity to alleviate Cd-stress on rice. The results obtained by this study suggested that the mitigation of Cd-toxicity on rice by Si might involve functions, such as the inhibition on Cd-uptake and transport and the enhancement on anti-oxidative enzyme activities, as well as the Lsi1-related expression on regulation of Si-uptake in rice. A new avenue might become available for overcoming the rampant pollution that threatens the rice production in China.

Current mechanism studies in plant heavy metal tolerance do not consider the effects of different phenolic acids on the bioavailability of heavy metals and the comparison with antioxidant enzyme system in the hydroxyl radical scavenging capacity. In present study, by a set of pot culture experiments with adding cadmium (Cd) and zinc (Zn) to the sediments, the effects of different phenolic acids on the toxicity of Cd and Zn in Kandelia obovata and the dominant role in scavenging hydroxyl radicals were evaluated. The results showed that 100 mg kg−1 Zn treatment promoted the growth of plant under high concentrations of Cd and Zn stress. Under the stress of Cd and Zn, the phenolic acids were mainly metabolized by phenylpropanoid and flavonoid pathways, supplemented by shikimate and monolignol pathways in K. obovata. Eleven phenolic acids with different abilities of scavenging free radicals were detected in the plant, including pyrogallic acid (Gal), coumaric acid (Cou), protocatechuic acid (Pro), chlorogenic acid (Chl), 4-hydroxy benzoic acid (Hyd), caffeic acid (Caf), vanillic acid (Van), ferulic acid (Fer), benzoic acid (Ben), and salicylic acid (Sal). By adding phenolic acids to the sediments, chlorogenic acid (Chl), pyrogallic acid (Gal), cinnamic acid (Cin), and coumaric acid (Cou) behave as more reactive in changing Cd or Zn into residual fractions than the others, and chlorogenic acid (Chl), pyrogallic acid (Gal), ferulic acid (Fer) and caffeic acid (Caf) have higher ability of scavenging hydroxyl radicals than the others. In summary, K. obovata tends to synthesize phenolic acids with strong scavenging ability of free radicals and changing the bioavailability of Cd and Zn under high concentration of Cd and Zn stress. Phenolic acids played a crucial role in the mitigative effect of heavy metal stress via scavenging free radicals and involving in the process of Cd and Zn uptake and tolerance. The results will provide important theoretical basis and method guidance for mangrove wetland conservation.

Metal-organic frameworks (MOFs) of type ZIF-67 via simple heat- treatment process was employed to prepare N-doped carbon nanotube frameworks (NCNTFs). Whereafter, an electroanalysis method using NCNTFs as the modify material was constructed for selective sensing of hydroquinone (HQ) and catechol (CC). Both HQ and CC can be independently determined in mixed solutions. The anodic peak currents of HQ increase linearly in two concentration ranges, one from 0.8 to 100 and another from 100 to 200 μM. Also, the anodic peak currents for CC increase linearly in the concentration ranges of 0.8–40 μM and 40–120 μM. The detection limits are 0.17 μM and 0.12 μM for HQ and CC, respectively. The sensor was used to detect these two isomers in spiked lake water, and recoveries for HQ and CC are 91.6–95.0% and 95.3–105.0%, respectively.

Nanosized mesoporous γ-alumina (M-γ-Al2O3) was first prepared and then modified into a carbon paste to fabricate a novel modified carbon paste electrode. The prepared alumina has pores with an amorphous wall and large surface area. The electrochemical behavior of the modified carbon paste electrode was investigated using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) methods. The modified carbon paste electrode was employed to determine Pb2+ and Cd2+ simultaneously by a differential pulse voltammetry (DPV) method. Amperometric determination was carried out in 0.1 mol L−1 NaAc–HAc buffer solution (pH 6.0) after enriching for 360 s at −1.0 V. The oxidation peak currents of Pb2+ and Cd2+ were proportional to their concentration in the range of 0.001–10 μmol L−1 and 0.01–10 μmol L−1, respectively. The detection limits of Pb2+ and Cd2+ were 0.20 nmol L−1 and 2.0 nmol L−1 (S/N = 3), respectively. The modified carbon paste electrode shows good stability, repeatability and sensitivity. The proposed method was applied to the determination of Pb2+ and Cd2+ in water samples with satisfactory results.

A highly selective electrochemical method was developed for the simultaneous determination of ascorbic acid (AA), dopamine (DA) and uric acid (UA) using a glassy carbon electrode modified by a poly( l -leucine)/DNA composite film. Cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) were used to study the electrochemical properties of the modified electrode. The modified electrode shows an excellent electrocatalytic activity towards the oxidation of AA, DA and UA. The separations of anodic peak potentials for AA/DA, DA/UA and AA/UA are 220, 158 and 378 mV ( vs . Ag/AgCl) in DPV, respectively. Under optimal conditions, the linear response range for AA, DA and UA are 5.0–750.0 μmol L −1 , 0.1–100.0 μmol L −1 and 0.5–100.0 μmol L −1 , respectively. The detection limits are 2.0, 0.04 and 0.2 μmol L −1 (S/N = 3), respectively. The present method was applied to the determination of AA, DA and UA in human urine sample and satisfactory results were obtained.

A rapid, accurate and simple method was developed for the simultaneous determination of glutathione (GSH) and phytochelatins (PCs) by high-performance liquid chromatography (HPLC) with an evaporative light-scattering detector. GSH, phytochelatin 2 (PC2), PC3, PC4, PC5 and PC6 can be separated with baseline separation within 9 min using a Venusil AA column (250 mm × 4.6 mm i.d., 5 µm particle sizes). Acetonitrile and water containing 0.1% trifluoroacetic acid (0.1%) were employed as the mobile phase for the gradient elution. The drift tube temperature and flow rate of the carrier gas (N2) were 50°C and 1.5 l min−1, respectively. Under optimum conditions, good linear regression equations of six analytes were obtained with the detection limits ranging from 0.2 to 0.5 µg ml−1. The proposed method has been applied successfully for the quantification of GSH and PCs in Perilla frutescens (a cadmium hyperaccumulator) under cadmium stress. The recoveries were between 82.9% and 115.3%.

The Philippine stock market is now the most expensive stock market in the Southeast Asia region. As of July 10, 2017, the total market capitalization is about 101 percent of the gross domestic product (GDP). Normally, the ratio between 75 percent and 90 percent is considered fairly valued. Thus, a risk management tool, which can quantitatively estimate the potential odds of a financial crisis, would be particularly useful for market participants. In this paper, we showed the Skewed t distribution could provide best goodness-of-fit for the Philippine stock market returns compared with several other widely used statistical distributions. The scenarios generated by the Skewed t distribution would be valuable for further risk analysis of the stock market.

A simple, effective, and green ion chromatography method with conductivity detection was developed for the determination of benzoic acid, cinnamic acid, syringic acid, and p-hydroxybenzoic acid in the root exudates of allelopathic rice. The analytes were well separated within 25 min in an anion exchange column (150 mm × 4.0 mm i.d., 5 µm particle size) with mixtures of 6.4 m mol L−1 Na2CO3 and 2.0 m mol L−1 NaHCO3 as the mobile phase at a flow-rate of 0.7 mL min−1. Detection limits of benzoic acid, cinnamic acid, syringic acid, and p-hydroxybenzoic acid were 0.05, 0.20, 0.50, and 0.05 µg mL−1, respectively. Intra- and inter-day precision was ≤4.0% and 3.2%, respectively, and the intra- and inter-day accuracy, indicated by relative error, ranged from −8.0% to 9.0%. The developed method was successfully used to determine phenolic acids in the root exudates of allelopathic rice. The average recoveries of the analytes were between 90.7% and 103.0%.

A polymerized film of 4-aminobutyric acid (P-4-ABA) was prepared on the surface of glassy carbon electrode (GCE) by electropolymerization. Cyclic voltammetry (CV), different pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) were used to study the electrochemical properties of the modified electrode. The results indicate that the P-4-ABA film has excellent electrocatalytic activity for the oxidation of ascorbic acid (AA), dopamine (DA) and uric acid (UA). The charge transfer coefficient, α , and the charge transfer rate constant, k s , for electron transfer between 4-ABA and GCE were also calculated as 0.53 and 25.70 ± 0.59 s −1 , respectively. Under optimal conditions, the peak separations between AA and DA, DA and UA, AA and UA at modified electrode using DPV method were 208, 136 and 344 mV, respectively. The linear response range for AA, DA and UA were 20.0–800.0 μmol L −1 , 5.0–100.0 μmol L −1 and 1.0–80.0 μmol L −1 , respectively, and the detection limits were 5.0, 1.0 and 0.5 μmol L −1 (S/N = 3). The modified electrode was successfully used to simultaneously determine AA, DA and UA in human urine sample.

Many publications indicated various beneficial effects of the addition of silicon (Si) in soil on the physiology of rice plants. The gene responsible for the Si-uptake in rice, low Si-influx 1 (Lsi1), was identified and cloned for this study. The photosynthetic rate (Pn), grain yield, and resistance to Cadmium (Cd)-stress of the wild-type (WT) and Lsi1-transgenic Lemont rice lines under Cd-stress were examined in an attempt to better understand the mechanism associated with the Si-addition, Cd-stress, and rice physiology. Si-fertilization significantly reduced the Cd-content in rice under Cd-stress. The effect was most significant in the Lsi1-overexpression transgenic Lemont rice (Lsi1-OE line) under high Cd-stress. Conversely, Cd in soil lowered the Si-uptake of the plants indicating a significant interaction between the two elements. During the grain-filling period, Cd-stress greatly reduced the chlorophyll content and Pn of the rice resulting in a diminished grain output. However, Lsi1-OE line with a higher chlorophyll content and Pn than either WT or Lsi1-RNAi transgenic Lemont rice (Lsi1-RNAi line) maintained a high photo-assimilate transportation for high yield potential. At harvest, Lsi1-OE line contained more Si and less Cd than WT, whereas the Lsi1-RNAi line showed an opposite result. In general, Cd-stress reduced, while Si-fertilization significantly increased, the grain yield on rice. However, no significant difference on the grain yields existed between WT and Lsi1-RNAi line. This might be due to a compensation effect generated by Lsi1-RNAi line. It appeared that Si in the soil, as well as the enhancing or inhibiting Lsi1 expression and the resistance to Cd-toxicity of the plants, could significantly affect the rice yield making alternations on these factors a plausible approach for production improvement.

We investigate the mechanism responsible for the formation of mesoporous silica formed with the so-called costructure directing agent (CSDA) route. The synthesis relies on the interaction between silica source (tetraethylorthosilicate), cationic surfactant (C18H37N+(CH3)2(CH2)3N+(CH3)3Br2), and CSDA (carboxyethylsilanetriol), which results in a material functionalized with carboxylic groups. Depending on the concentration of HCl in the synthesis, the structure is defined by Fm3m (at high pH) and by Fd3m (at low pH), with a gradual transition in the intermediate pH range. Here, we aim at finding the origin for the structural change triggered by pH and investigate the effects of the hydrolysis of the silica source on the overall kinetics of the synthesis. A fast process results in Fm3m, regardless of pH, and a slow process results in Fd3m. The hydrolysis step is the important structural control parameter. We studied the cross-linking of silica and CSDA using 29Si NMR. The cross-linking is similar for th...

Soil rhizospheric metaproteomics is a powerful scientific tool to uncover the interactions between plants and microorganisms in the soil ecosystem. The present study established an extraction method suitable for different soils that could increase the extracted protein content. Close to 1000 separate spots with high reproducibility could be identified in the stained 2-DE gels. Among the spots, 189 spots representing 122 proteins on a 2-DE gel of rice soil samples were successfully identified by MALDI-TOF/TOF-MS. These proteins mainly originated from rice and microorganisms. They were involved in protein, energy, nucleotide, and secondary metabolisms, as well as signal transduction and resistance. Three characteristics of the crop rhizospheric metaproteomics seemed apparent: (1) approximately one-third of the protein spots could not be identified by MALDI-TOF/TOF/MS, (2) the conservative proteins from plants formed a feature distribution of crop rhizospheric metaproteome, and (3) there were very complex interactions between plants and microorganisms existing in a crop rhizospheric soil. Further functional analysis on the identified proteins unveiled various metabolic pathways and signal transductions involved in the soil biotic community. This study provides a paradigm for metaproteomic research on soil biology.

Crop allelopathy is a promising and environmentally friendly method in weed control; however, the inducible genetic trait for allelopathy in the suppression of weeds needs to be overcome for practical use. Further study needs to be directed to this end to elucidate the molecular genetics and its physiologic mechanism. In this paper, the authors review recent advances in the investigation of rice allelopathy and its molecular regulatory mechanism, especially in responses to stressful conditions including biotic and abiotic factors in China. Previous studies show that rice allelopathy could be enhanced when the rice accession was exposed to stressful conditions, and further analysis by the transcriptomics and proteomics approaches conducted in our laboratory indicated that the increase in allelopathic potential of rice, when exposed to the stresses, was attributed to increased expression level of genes involved in phenolic synthetic metabolism. The increasing phenolic compounds have been confirmed as the main allelochemicals and they jointly act to suppress the target, especially in responses to stressful condition, but it seems to be the primary effect in phenolic allelopathy. We still wonder how the exudates from rice root, which were released into rhizosphere soil, are transformed by soil microorganism to produce the higher secondary effect of phenolic allelopathy in the suppression of weeds. Therefore, the authors suggest that rhizosphere biologic properties of allelopathy in rice and its mechanism are being the key research areas in the world now, and systems biology and its approaches, such as metagenomics and metaproteomics, would be helpful to reveal the process and its molecular ecological mechanism regarding rhizospheric biology of rice allelopathy.

A rapid, accurate and simple method was developed for the simultaneous determination of glutathione (GSH) and phytochelatins (PCs) by high-performance liquid chromatography (HPLC) with an evaporative light-scattering detector. GSH, phytochelatin 2 (PC 2 ), PC 3 , PC 4 , PC 5 and PC 6 can be separated with baseline separation within 9 min using a Venusil AA column (250 mm × 4.6 mm i.d., 5 µm particle sizes). Acetonitrile and water containing 0.1% trifluoroacetic acid (0.1%) were employed as the mobile phase for the gradient elution. The drift tube temperature and flow rate of the carrier gas (N 2 ) were 50°C and 1.5 l min −1 , respectively. Under optimum conditions, good linear regression equations of six analytes were obtained with the detection limits ranging from 0.2 to 0.5 µg ml −1 . The proposed method has been applied successfully for the quantification of GSH and PCs in Perilla frutescens (a cadmium hyperaccumulator) under cadmium stress. The recoveries were between 82.9% and 115.3%.

The defense characteristics of allelopathic rice accession PI312777 and its counterpart Lemont induced by exogenous salicylic acid (SA) to suppress troublesome weed barnyardgrass (BYG) were investigated using the methods of suppression subtractive hybridization (SSH) and real-time fluorescence quantitative PCR (qRT-PCR). The results showed that exogenous SA could induce the allelopathic effect of rice on BYG and this inducible defense was SA dose-respondent and treatment time-dependent. PI312777 exhibited higher inhibitory effect than Lemont on BYG after treated with different concentrations of SA. The activities of cell protective enzymes including SOD, POD and CAT in the BYG plants co-cultured with PI312777 treated by SA were highly depressed compared with the control (co-cultured with rice without SA-treatment). Similar but lower depression on these enzymes except for CAT was also observed in the BYG plants when co-cultured with Lemont treated by SA. It is therefore suggested that allelopathic rice should be more sensitive than non-allelopathic rice to exogenous SA. Seventeen genes induced by SA were obtained by SSH analysis from PI312777. These genes encode receptor-kinase proteins, ubiquitin carrier proteins, proteins related to phenylpropanoid metabolism, antioxidant related proteins and some growth-mediating proteins. The differential expressions of these genes were validated in part by qRT-PCR in the two rice accessions. Our work elucidated that allelopathic rice possesses an active chemical defense and auto-detoxifying enzyme system such as the up-regulated enzymes involved in de novo biosynthesis of phenolic allelochemicals and the glutathione-S-transferase (GST) associated with xenobiotic detoxification.

In China, the construction of asphalt pavement has a significant impact on the environment, and energy use and greenhouse gas (GHG) emissions from asphalt pavement construction have been receiving increasing attention in recent years. At present, there is no universal criterion for the evaluation of GHG emissions in asphalt pavement construction. This paper proposes to define the system boundaries for GHG emissions from asphalt pavement by using a process-based life cycle assessment method. A method for evaluating GHG emissions from asphalt pavement construction is suggested. The paper reports a case study of GHG emissions from a typical asphalt pavement construction project in China. The results show that the greenhouse gas emissions from the mixture mixing phase are the highest, and account for about 54% of the total amount. The second highest GHG emission phase is the production of raw materials. For GHG emissions of cement stabilized base/subbase, the production of raw materials emits the most, about 98%. The GHG emission for cement production alone is about 92%. The results indicate that any measures to reduce GHG emissions from asphalt pavement construction should be focused on the raw materials manufacturing stage. If the raw materials production phase is excluded, the measures to reduce GHG emissions should be aimed at the mixture mixing phase.

Based on the determination of dry matter and caloric value, this paper studied the characteristics of energy accumulation and the dynamics of caloric value in the yield-forming process of rice cultivars Shanyou 63 ( three-line hybrid rice) , Liangyou 2186 (two-line hybrid rice) , and IR64 (conventional rice). The results showed that at fully grain-maturing stage, the amount of dry matter in Shanyou 63, Liangyou 2186 and IR64 was 1926. 38 g x m(2), 1933.80 g x m(-2) and 1842.30 g x m(-2), and that of accumulated energy was 31,137.05 kJ x m(-2) 31 060.63 kJ x m(-2) and 30 454.89 kJ x m(-2) , respectively, showing no significant difference among the cultivars. In the process of grain filling, the apparent transformation ratio of energy in Shanyou 63, Liangyou 2186 and IR64 was about 38. 95% , 28. 38% and 32. 66% , respectively, implying that the energy flow in Shanyou 63 and IR 64 was smoother than that in Liangyou 2186, and the output of energy from stem to the sink of grain was blocked in Liangyou 2186. The ratio of energy partitioning to the sink of grain was 53. 03% , 46. 43% and 50. 11% for Shanyou 63, Liangyou 2186 and IR64, respectively, showing the energy partitioning heterosis in three-line hybrid rice Shanyou 63. As for the caloric value, it had no significant difference among the three cultivars, but decreased in the order of leafgrainsheathstemroot, ranging from 16.81-17.25 kJ x g(-1) , 15.89-16.54 kJ x g (-1) 14.33-15.49 kJ x g(-1) , 14.23-15.15 kJ x g , and 11.51-13.25 kJ x g(-1), respectively. It was also shown that there was a significant positive correlation of caloric value with carbon content, chlorophyll a content, and nitrogen content in rice plant, with the determination coefficient R(2) being 0.609, 0.471 and 0.485, respectively.

In this study, allelopathic rice accession PI312777 seedlings were grown on a paddy soil under near natural condition, and their root exudates were collected by using circulation method, with the solution collected from no seedlings- planted soil as the control. The ether extracts of the root exudates and soil solution were detected by GC-MS, and identified with the mass spectral database of NIST and WILEY Library. The results showed that there were 36 compounds in the rice root exudates, including 9 terpenoids (peak area 10.97%), 8 phenols or quinones (5.87%), 6 esters (10.68%), 3 aldehydes or ketones (1.44%), 4 heterocycles (68.04%), 2 alcohols (1.23%), 2 ethers (0.57%), and 2 others (1.20%). A distinctly similar structure was observed among the terpenoids and among the phenols or quinones. In the soil solution, 39 compounds were detected, and 7 of them were the same of the root exudates. The difference of the compounds in rice root exudates and soil solution, and the possible allelopathic mechanisms of these compounds were discussed in this paper.

Background The current study was undertaken to elucidate the mechanism of yield decline in ratoon sugarcane using soil metaproteomics combined with community level physiological profiles (CLPP) analysis. Results The available stalk number, stalk diameter, single stalk weight and theoretical yield of ratoon cane (RS) were found to be significantly lower than those of plant cane (NS). The activities of several carbon, nitrogen and phosphorus processing enzymes, including invertase, peroxidase, urease and phosphomonoesterase were found to be significantly lower in RS soil than in NS soil. BIOLOG analysis indicated a significant decline in average well-color development (AWCD), Shannon’s diversity and evenness indices in RS soil as compared to NS soil. To profile the rhizospheric metaproteome, 109 soil protein spots with high resolution and repeatability were successfully identified. These proteins were found to be involved in carbohydrate/energy, amino acid, protein, nucleotide, auxin and secondary metabolisms, membrane transport, signal transduction and resistance, etc. Comparative metaproteomics analysis revealed that 38 proteins were differentially expressed in the RS soil as compared to the control soil or NS soil. Among these, most of the plant proteins related to carbohydrate and amino acid metabolism and stress response were up-regulated in RS soil. Furthermore, several microbial proteins related to membrane transport and signal transduction were up-regulated in RS soil. These proteins were speculated to function in root colonization by microbes. Conclusions Our experiments revealed that sugarcane ratooning practice induced significant changes in the soil enzyme activities, the catabolic diversity of microbial community, and the expression level of soil proteins. They influenced the biochemical processes in the rhizosphere ecosystem and mediated the interactions between plants and soil microbes.

A simple and effective procedure based on a molecularly imprinted polymer (MIP) was developed for preparing a selective 4-aminobutyric acid (4-ABA) sensor. The sensitive layer was prepared by electropolymerization of o-phenylenediamine (o-PD) on a gold electrode in the presence of 4-ABA, which acts as a template. Cyclic voltammetry (CV), differential pulse voltammetry (DPV), linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS) measurements were used to monitor the process of electropolymerization. The molecularly imprinted sensor was tested by CV as well as DPV to verify the changes of redox currents of hexacyanoferrate. The concentration of 4-ABA in the range of 0.2–20.0 μmol L−1 can be determined with a detection limit of 0.08 μmol L−1 (defined as S/N = 3) under the optimum conditions. The MIP sensor shows high selectivity, sensitivity and reproducibility. The results from sample analysis indicate that the MIP-4-ABA sensor can be used for quantitative analysis.