[Effects of Nano-copper Oxide on Physiobiochemical Properties of Brassica chinensis L. and Its Heavy Metal Accumulation Under Cadmium Stress].

To investigate the effects of nano-copper oxide (CuO NPs) on plant growth, physio-biochemical characteristics, and heavy metal content under cadmium stress, a hydroponics experiment was conducted on the effects of single and combined treatments of CuO NPs (0, 10, 20, and 50 mg·L-1) and Cd (0, 1, and 5 µmol·L-1) on the fresh weight, photosynthetic pigment content, MDA content, antioxidant enzyme activity (CAT, POD, SOD, and GR), and Cu and Cd contents in Brassica chinensis L. The results showed that under the single addition of CuO NPs, the fresh weight and activities of CAT, POD, and GR were inhibited as a whole. Photosynthetic pigment content and SOD activity increased first and then decreased with the increase in CuO NPs concentration, whereas MDA content in leaves and roots, and Cu content in subcells of B. chinensis L. increased with the increasing of CuO NPs. As compared with that in the control, CuO NPs promoted the growth of B. chinensis L., and the fresh weight increased by 8.70%-44.87% at 1 µmol·L-1 Cd. When the content of Cd was up to 5 µmol·L-1, a low content (10 mg·L-1) of CuO NPs promoted the growth of B. chinensis L., whereas a high concentration (50 mg·L-1) showed an inhibitory effect. The addition of CuO NPs could increase photosynthetic pigment and MDA contents under different Cd stress, and MDA content in leaves and roots of B. chinensis L. increased by 4.34%-36.27% and 13.43%-131.04%, respectively, than that in the control groups. Under the same concentration of 1 µmol·L-1 Cd, the addition of CuO NPs decreased the activities of CAT and GR, whereas the activity of POD increased. When the content of Cd was up to 5 µmol·L-1, CuO NPs increased the POD activity and inhibited the activity of SOD and GR. The activities of CAT and CAT in the leaves of B. chinensis L. initially showed an increasing and then decreasing trend. CuO NPs and Cd showed antagonistic effects, the maximum reduction of Cd content in leaves and roots of Brassica chinensis L. under 1 µmol·L-1 Cd treatment was 45.64% and 33.39%, and that under 5 µmol·L-1 Cd treatment was 18.25% and 25.35%, respectively. The content of Cu and Cd in subcellular organs of the plants decreased, but the proportion of soluble components increased. These results indicated that CuO NPs at low concentrations promoted plant growth under Cd stress and further inhibited the absorption of Cd but increased the oxidative damage to B. chinensis L.

CD147-specific chimeric antigen receptor T cells effectively inhibit T cell acute lymphoblastic leukemia.

T cell acute lymphoblastic leukemia (T-ALL) is invasive and heterogeneous, and existing therapies are sometimes unsuccessful. Chimeric antigen receptor (CAR) T cell therapy is a breakthrough tumor treatment method, particularly for B cell acute lymphoblastic leukemia. We found that CD147 was highly expressed in tumor T cells of T-ALL patients and T cell lymphoma. Therefore, CD147-CAR T cells that contain a humanized single-chain variable fragment targeting human CD147 and a second-generation CAR frame were constructed for treating T-ALL. CD147-CAR T cells were able to maintain a healthy proliferation rate, preserving a subset of CD62L+/CCR7+ memory T cells. CD147-CAR T cells showed a potent anti-tumor activity against human T-ALL cell line and T-ALL blasts, releasing high level of cytokines in the process. However, CD147-CAR T cells exhibited potential safety toward human normal cells and CD147-deficent cells. NOD/ShiLtJGpt-Prkdcem26Cd52Il2rgem26Cd22/Gpt mice were used to establish a T-ALL xenograft model and CD147-CAR T cells conferred robust protection against T-ALL progression and significantly improved survival in mice. Overall, we found that CD147 is a potential antigen target of CAR T cell therapy for T-ALL.

Porous Cr2O3 Architecture Assembled by Nano-Sized Cylinders/Ellipsoids for Enhanced Sensing to Trace H2S Gas.

How to achieve high sensing of Cr2O3-based sensors for harmful inorganic gases is still a challenge. To this end, Cr2O3 nanomaterials assembled from different building blocks were simply prepared by chromium salt immersion and air calcination with waste scallion roots as the biomass template. The hierarchical architecture calcined at 600 °C is constructed from nanocylinders and nanoellipsoids (named as Cr2O3-600), and also possesses multistage pore distribution for target gas accessibility. Interestingly, the synergism of two shapes of nanocrystals enables the Cr2O3-based sensor to realize highly sensitive detection of trace H2S gas. At 170 °C, Cr2O3-600 exhibits a high response of 42.8 to 100 ppm H2S gas, which is 3.45 times larger than that of Cr2O3-500 assembled from nanocylinders. Meanwhile, this sensor has a low detection limit of 1.0 ppb (S = 1.4), good selectivity, stability, and moisture resistance. These results show that the combination of nanosized cylinders/ellipsoids together with exposed (104) facet can effectively improve the sensing performance of the p-type Cr2O3 material. In addition, the Cr2O3-600 sensor shows satisfactory results for actual monitoring of the corruption process of fresh chicken.

[Variations in Cadmium Accumulation and Transport and Ionomic Traits Among Different Winter Wheat Varieties].

A field trial was conducted to identify the key factors affecting intraspecific variation in the cadmium (Cd) content in the grain of winter wheat. Three wheat cultivars with low Cd accumulation and two wheat cultivars with high Cd accumulation were planted. The Cd accumulation and transport and ionomic traits were examined in different organs of the tested wheat cultivars. Additionally, correlation analysis and principal component analysis were used to identify the key plant organs, translocation pathways, and elements that determine the intraspecific variation in the Cd content in wheat grain. The results showed that the bioaccumulation factors of Cd in glume, rachis, internode 1, and node 1, as well as the transport factors of Cd from rachis to grain, from rachis to glume, from internode 1 to rachis, and from node 1 to internode 1, were significantly correlated with Cd bioaccumulation factors in grain. The above-mentioned bioaccumulation factors and transport factors of Cd made a great contribution to the principal components that could discriminate between the wheat cultivars with low and high Cd accumulation and were significantly different among cultivars. Therefore, glume, rachis, internode 1, and node 1 were the key organs affecting the genotype differences in Cd content in wheat grain, and Cd translocation from rachis to grain, from rachis to glume, from internode 1 to rachis, and from node 1 to internode 1 were the key pathways controlling the variety differences in Cd accumulation in wheat grain. The analysis of wheat ionome showed that the bioaccumulation factors of Mg and Mn in the key organs and the transport factors of Mo, Cr, and Pb in the key transport pathways were significantly correlated with the bioaccumulation factor of Cd in wheat grain and contributed greatly to the differentiation between the wheat cultivars with low and high Cd accumulation in the principal component analyses. Thus, in the above-mentioned key organs and transport pathways, Mg, Mn, Mo, Cr, and Pb were the key elements affecting the genotype differences in Cd content in wheat grain.

[Effects of Intercropping of Brassica chinenesis L. and Tagetes patula L. on the Growth and Cadmium Accumulation of Plants].

A pot experiment was conducted to reveal the effects of intercropping a low-cadmium (Cd) accumulating cultivar and a Cd hyperaccumulator on the safe utilization and phytoextraction of Cd-polluted soils. Two cultivars of Brassica chinensis L. (the low-Cd accumulating cultivar Huajun, and the common cultivar Hanlü), were intercropped with four cultivars of Tagetes patula L. (Dwarf Red, Dwarf Yellow, Tall Red, and Tall Yellow). We examined the biomass, photosynthetic characteristics, and Cd accumulation in the plants and available Cd content and dissolved organic carbon (DOC) content in the soils. The results show that under the intercropping treatments, the biomass of B. chinensis decreased significantly and those of T. patula increased significantly, compared with the monoculture treatments. When intercropped with T. patula, the net photosynthetic rate, stomatal conductance, and transpiration rate in the leaves of B. chinensis decreased significantly, compared with the monoculture treatments. When Huajun was intercropped with Dwarf Red, the shoot Cd content of Huajun significantly decreased by 14.5%, and that of Dwarf Red increased significantly by 36.5% compared with the monoculture. Under the other intercropping treatments, the shoot Cd content of B. chinensis increased significantly, or showed no significant change, and that of T. patula showed no significant change. Under the intercropping treatments, the total amount of Cd in the shoot of B. chinensis decreased significantly, and that of T. patula increased significantly, compared with the monoculture. There were no significant differences in the Cd extraction ratios between the intercropping treatments and the monoculture of T. patula. The shoot Cd content of B. chinensis was significantly correlated with soil available Cd content and DOC content (P<0.01 and P<0.05, respectively). In conclusion, the intercropping treatment of Huajun and Dwarf Red significantly reduced shoot Cd content in B. chinensis and increased that in T. patula, and it did not affect the Cd extraction ratio. This is suitable for the safe utilization and phytoextraction of Cd-polluted soils.

[Effect of Mn-Modified Biochar on the Characteristics of Aggregate Structure and the Content of Cd in Weakly Alkaline Cd-Contaminated Soil].

Field experiments were conducted to investigate the effects of Mn-based modified rice husk biochar on soil organic carbon, aggregate structure, mass load, and the content of available Cd in aggregates. The results showed that the concentration of soil organic carbon increased gradually with additional modified biochar, resulting in a 3.2%-32% increase compared with the CK. Modified biochar improved the composition structure and stability of soil aggregates, and increased the amount of large aggregates (5-8 mm and 2-5 mm), while micro-aggregate production was inhibited (≤0.25 mm). Compared with the CK, mean weight diameter (MWD), geometrical mean weight (GMD), and soil aggregate structural body (R0.25) of the soil aggregates increased by 15.1%-20.3%, 8.1%-22.4%, and 0.43%-7.6%, respectively. Cd was preferentially enriched on small aggregates, and the mass loading of Cd in soil aggregates increased gradually with decreasing particle size. The distribution factor of Cd showed significant enrichment in the 0.5-1 mm and 0.25-0.5 mm grain sizes, whereas it showed a clear loss in particle sizes of 5-8 mm and 2-5 mm. The addition of modified biochar reduced the content of DTPA-Cd in soil aggregates, causing 7.6%-15.1%, 15.6%-24.3%, 3.6%-13.8%, and 11.6%-13.7% reductions in 5-8, 2-5, 0.5-1.0, and 0.25-0.5 mm particle sizes, respectively. In general, modified biochar not only has a favorable optimizing function on the structure of soil aggregates, but also decreases the content of available Cd in different sizes of soil aggregates, increasing its significance in the remediation of Cd-contaminated soil.

[Substructure Characteristics of Combined Acid-Base Modified Sepiolite and Its Adsorption for Cd(â ¡)].

To enhance the adsorption capacity of sepiolite (Sep) on Cd2+ in solution, an acid-base Sep (ABsep) was obtained using the method of combined acid-base modification. The structural properties of Sep and ABsep were analyzed by adsorption-desorption isotherms of N2, scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), and X-ray powder diffraction (XRD). Static adsorption experiments were carried out to evaluate the effects of time, mass ratio of ABsep/Cd2+, temperature, adsorbent dose, pH, and co-existing ions on the adsorption of Cd2+ by ABsep. The results showed that the pore structure of the ABsep was more developed than that of Sep. In comparison to Sep, the specific surface area, average pore diameter, and pore volume of ABsep increased by 66.1%, 15.7%, and 34.8%, respectively, and the exchangeable ion contents also increased. The main components of the ABsep were SiO2 and Mg(OH)2. The adsorption process of Cd2+ by Sep and ABsep could be well fitted with a pseudo-second-order kinetic equation and Langmuir isotherm, and both were spontaneous endothermic reactions, which were mainly chemical adsorption along with physical adsorption. The best mass ratio of ABsep:Cd2+ was 3:1, and the maximum saturated adsorption capacity fitted by the Sips model of the ABsep on Cd2+ at 298 K was 142.43 mg·g-1, which was 3.55 times that of Sep. As the adsorbent dose increased, the adsorption amounts of Cd2+ first increased and then decreased, with the optimum dose being 0.3 g·L-1. The amount of Cd2+ adsorption by the ABsep increased with the initial pH of the solution, whereby the best pH was 7. We also found that the presence of K+, Na+, Mg2+, and Ca2+ at different concentrations could inhibit the adsorption of Cd2+, whereby the inhibition of Mg2+ was the highest.

[Effect of Different Passivating Agents on the Stabilization of Heavy Metals in Chicken Manure Compost and Its Maturity Evaluating Indexes].

We explore the effects of different passivating agents on livestock manure treatment by using chicken manure and straw as raw materials and thermophilic rapid fermentation. We investigate the effects of sepiolite (SE), calcium magnesium phosphate fertilizer (NP), biochar (BI), compounds of sepiolite plus calcium magnesium phosphate fertilizer (S+N), sepiolite plus biochar (S+B), calcium magnesium phosphate fertilizer plus biochar (N+B), and sepiolite plus calcium magnesium phosphate fertilizer and biochar (SNB) on the physical and chemical characteristics, heavy metal fraction and distribution, and organic matter content in chicken manure compost. The results showed that the addition of different passivating agents significantly increased the pH in chicken manure organic fertilizer (P<0.05). The seed germination rate was increased after applying of passivation agents, being>80%, and the germination inhibition rate decreased accordingly, whereas the values of electric conductivity (EC) and organic carbon were inhibited. The total nitrogen content and carbon/nitrogen ratio (C/N) were lower than of those before composting, and all of the indicators reached the standard of organic fertilizer maturity. However, differences among the groups after composting were that the pH increase in the compounding treatment was comparatively higher, and that the EC decreased significantly under the treatment of the single sepiolite and calcium magnesium phosphate, whereas the total nitrogen content and C/N ratio of organic carbon were not significantly different in each group. Although the total amount of heavy metals in our organic chicken manure fertilizer increased due to a concentration effect, the proportion of exchangeable heavy metals in the fertilizer decreased, and while the ratio of the residual heavy metals increased. The passivation effect on heavy metals under combined treatments of different materials was better than that of a single agent, and the SNB treatment had the best effect on the passivation of Ni, Zn, As, and Pb. After composting treatment, the concentrations of humic substances (HS) and humic acid (HA) increased significantly (P<0.05), and the highest concentrations increased by 19.8% and 78.9%, respectively. The amount of fulvic acid (FA) decreased by 4.47%-20.11% compared with the initial conditions. Infrared spectroscopy analysis showed that the small molecular substances of polysaccharides increased after composting. In summary, the addition of a passivation agent can promote the heavy metal passivation in chicken manure organic fertilizers to potentially render the compost as harmless.

Large-Scale Synthesis of Hierarchically Porous ZnO Hollow Tubule for Fast Response to ppb-Level H2S Gas.

Response and recovery time to toxic and inflammable hydrogen sulfide (H2S) gas are important indexes for metal oxide sensors in real-time environmental monitoring. However, large-scale production of ZnO-based sensing materials for fast response to ppb-level H2S has been rarely reported. In this work, hierarchically porous hexagonal ZnO hollow tubule was simply fabricated by zinc salt impregnation and subsequently calcination using absorbent cotton as the template. The influence of calcination temperature on the corresponding morphology and sensing properties is also explored. The hollow tubules calcined at 600 °C are constructed from abundant cross-linked nanoparticles (∼20 nm). Its Brunauer-Emmett-Teller surface area is 31 m2·g-1 and the meso- and macroporous sizes are centered at 35 and 115 nm, respectively. The sensor with a lower detection limit of 10 ppb exhibits a fast response speed of 29 s toward the 50 ppb H2S rather than those of the reported intrinsic and doped ZnO-based sensing materials. Furthermore, the sensor shows a wide linear range (10-1000 ppb), good reproducibility, and stability. Such excellent trace ppb-level H2S performances are mainly related to the inherent characteristics of hierarchically porous hollow tubular structure and the surface-adsorbed oxygen control type mechanism.

Enhanced Sub-ppm NH3 Gas Sensing Performance of PANI/TiO2 Nanocomposites at Room Temperature.

PANI/TiO2 nanocomposites spheres were synthesized using a simple and efficient one-step hydrothermal process. The morphology and structure of PANI/TiO2 nanocomposites spheres were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) techniques. The PANI/TiO2 nanocomposite sphere-based sensor exhibits good selectivity, sensitivity (5.4 to 100 ppm), repeatability, long-term stability and low detection limit (0.5 ppm) to ammonia at room temperature (20 ± 5°C). It also shows a good linearity relationship in the range of 0.5-5 and 5-100 ppm. The excellent NH3 sensing performance is mainly due to the formation of the p-n heterostructure in the nanocomposites.

[Characteristics of Heavy Metals in Chicken Manure Organic Fertilizers in the Huang-Huai-Hai Region and related Environmental Risk Assessment].

One hundred and twenty types of chicken manure organic fertilizer samples were collected from five provinces and two cities in the Huang-Huai-Hai region, to investigate heavy metal content, fractionation, and environmental risk through toxicity characteristic leaching procedures. Results showed that content of heavy metals in chicken manure organic fertilizer varied greatly, in the order of Zn > Cu > Pb > As > Cd. When compared with the standard for organic manure, ratios of Cd, As, and Pb exceeded the standard by 6.7%, 47.05%, and 14.28%, respectively. Moreover, the content of heavy metals varied significantly in different provinces. Cd and Zn in organic manure fertilizers were mainly Fe and Mn oxide-bound fractions, accounting for 37.3% and 43.79%, respectively. However, the proportion of residual fractions of Pb, organically-bound fractions of Cu, and exchangeable forms of As were higher. Contents of TCLP-Zn,-Cu,-Cd,-Pb and-As in organic manure were 41.11, 33.3, 0.07, 1.25, and 0.21 mg·kg-1, respectively. The number of samples in which Zn and Pb in organic manure exceeded the standard was 6 and 5, respectively, with these mainly obtained from Hebei and Jiangsu provinces. There was a significant correlation between total content of Zn, Cu, Cd, and As in organic manure and content of TCLP (P<0.05). Based on an annual manure application rate of chicken manure of 15 t·hm-2, safe application of chicken manure is in the order of Henan > Tianjin > Anhui=Shandong=Jiangsu > Hebei > Beijin.

[Effect of Foliar Zinc Application on Bioaccessibility of Cadmium and Zinc in Pakchoi].

Two cultivars of pakchoi with different cadmium (Cd) accumulation were grown in nutrient solutions containing low and sufficient zinc (Zn) levels. ZnSO4 and ZnNa2 EDTA were applied as foliar fertilizers. The bioaccessibilities of Cd and Zn in pakchoi were assessed by the in vitro digestion method, and the bioaccessible established daily intakes (BEDI) of Cd and Zn from pakchoi were calculated. The effect of foliar zinc application on concentrations, bioaccessibilities, and BEDIs of Cd and Zn in pakchoi was evaluated. Results show that the Cd concentrations in shoots of the tested pakchoi cultivars under sufficient Zn condition were significantly lower than those under low Zn condition, and foliar application of ZnNa2 EDTA significantly decreased the Cd concentrations of pakchoi. The tested pakchoi cultivars with sufficient Zn had a significantly higher mean shoot Zn concentration than those with low Zn. Foliar Zn treatments significantly increased shoot Zn concentrations of pakchoi, with the highest in the ZnSO4 treatment. Cd bioaccessibility in the tested pakchoi cultivars with sufficient Zn was significantly lower than that with low Zn. Foliar applied Zn could significantly reduce Cd bioaccessibility in the gastric phase, with a maximal reduction of 35.81% compared to the control. Foliar treatment with ZnSO4 could significantly decrease Cd bioaccessibility in the small intestinal phase, with a maximal reduction of 59.24% compared to the control. Foliar Zn treatments reduced significantly the Zn bioaccessibility of pakchoi in the gastric and small intestinal phases, with a maximal reduction of 68.90% compared to the control. The reduction of Zn bioaccessibility was higher in the ZnSO4 treatment than in the ZnNa2 EDTA treatment. Via the consumption of the Cd-contaminated common cultivar Hanlv, the BEDI values of Cd were higher than that of the provisional tolerable daily intake (PTDI) standard of WHO [0.83 µg·(kg·d)-1]. However, via the consumption of the low-Cd accumulating cultivar Huajun or pakchoi with foliar application of ZnSO4, the BEDI values of Cd decreased significantly and were below the PTDI value. Via the consumption of pakchoi in the control or low-level ZnNa2 EDTA treatments, the BEDI values of Zn were below that of the recommended nutrient intake for Zn. However, via the consumption of pakchoi with foliar application of ZnSO4 or high-level ZnNa2 EDTA, the BEDI values of Zn were higher than that of the recommended nutrient intake and met the human needs for Zn from vegetables. Under the ZnSO4 treatment, the BEDI values of Zn from pakchoi were the highest. In conclusion, foliar zinc application could significantly reduce the bioaccessibilities of Cd and Zn in pakchoi and the BEDI values of Cd and increase the BEDI values of Zn. Foliar application with ZnSO4 was the most suitable treatment to reduce Cd intake and increase Zn intake from pakchoi.

Burkholderia metalliresistens sp. nov., a multiple metal-resistant and phosphate-solubilising species isolated from heavy metal-polluted soil in Southeast China.

A metal-resistant and phosphate-solubilising bacterium, designated as strain D414(T), was isolated from heavy metal (Pb, Cd, Cu and Zn)-polluted paddy soils at the surrounding area of Dabao Mountain Mine in Southeast China. The minimum inhibitory concentrations of heavy metals for strain D414(T) were 2000 mg L(-1) (Cd), 800 mg L(-1) (Pb), 150 mg L(-1) (Cu) and 2500 mg L(-1) (Zn). The strain possessed plant growth-promoting properties, such as 1-aminocyclopropane-1-carboxylate assimilation, indole production and phosphate solubilisation. Analysis of 16S rRNA gene sequence indicated that the isolate is a member of the genus Burkholderia where strain D414(T) formed a distinct phyletic line with validly described Burkholderia species. Strain D414(T) is closely related to Burkholderia tropica DSM 15359(T), B. bannensis NBRC E25(T) and B. unamae DSM 17197(T), with 98.5, 98.3 and 98.3 % sequence similarities, respectively. Furthermore, less than 34 % DNA-DNA relatedness was detected between strain D414(T) and the type strains of the phylogenetically closest species of Burkholderia. The dominant fatty acids of strain D414(T) were C14:0, C16:0, C17:0 cyclo and C18:1 ω7c. The DNA G+C content was 62.3 ± 0.5 mol%. On the basis of genotypic, phenotypic and phylogenetic data, strain D414(T) represents a novel species, for which the name Burkholderia metalliresistens sp. nov. is proposed, with D414(T) (=CICC 10561(T) = DSM 26823(T)) as the type strain.

GABAergic inhibition regulated pain sensitization through STEP61 signaling in spinal dorsal horn of mice.

BACKGROUND: The reduction of γ-aminobutyric acid (GABA) type A receptor-mediated inhibition has long been implicated in spinal sensitization of nociceptive responses. However, it is largely unknown which signaling cascades in spinal dorsal horn neurons are initiated by the reduced inhibition to trigger pain hypersensitivity. METHODS: GABAergic inhibition was manipulated by intrathecal application of GABA type A receptor antagonist bicuculline in intact mice or by GABA type A receptor agonist muscimol in complete Freund's adjuvant-injected mice. Immunoblotting, coimmunoprecipitation, immunohistochemistry, and behavioral tests were used to explore the signaling pathways downstream of the altered GABAergic tone. RESULTS: The study data revealed that the 61-kD isoform of striatal-enriched protein phosphatase (STEP61) was a key molecule that relayed the signals from GABAergic neurotransmission. The authors found that STEP61 was highly expressed in dorsal horn neurons. Under physiological conditions, STEP61 tonically interacted with and negatively controlled the activities of extracellular signal-regulated kinase and Src-family protein tyrosine kinases member Fyn, two critical kinases involved in spinal sensitization. Once GABAergic inhibition was impaired, STEP61 interaction with its substrates was substantially disturbed, allowing for activation of extracellular signal-regulated kinase and Fyn (n = 4 to 6). The hyperactivities of extracellular signal-regulated kinase and Fyn, along with STEP61 dysregulation, caused the tyrosine phosphorylation and synaptic accumulation of GluN2B subunit-containing N-methyl-D-aspartate subtype of glutamate receptors (n = 6), leading to GluN2B receptor-dependent pain hypersensitivity. Overexpression of wild-type STEP61 to resume its enzymatic activity significantly blocked the mechanical allodynia evoked by bicuculline and more importantly, alleviated chronic inflammatory pain (n = 6 in each group). CONCLUSION: These data identified STEP61 as a key intermediary for GABAergic inhibition to regulate pain sensitization.

α(2) noradrenergic receptor suppressed CaMKII signaling in spinal dorsal horn of mice with inflammatory pain.

Intrathecal application of α2 noradrenergic receptor agonists effectively alleviates the pathological pain induced by peripheral tissue injury. However, the spinal antinociceptive mechanisms of α2 noradrenergic receptors remain to be characterized. The present study performed immunohistochemistry and western blot to elucidate the signaling pathway initiated by α2 noradrenergic receptors in spinal dorsal horn of mice, and identified calcium/calmodulin-dependent protein kinase II (CaMKII) as an important target for noradrenergic suppression of inflammatory pain. Our data showed that intraplantar injection of Complete Freund's Adjuvant (CFA) substantially enhanced CaMKII autophosphorylation at Threonine 286, which could be abolished by intrathecal administration of α2 noradrenergic receptor agonist clonidine. Gi protein-coupled α2 noradrenergic receptor might inhibit cAMP-dependent protein kinase (PKA) to disturb CaMKII signaling. We found that pharmacological activation of PKA in intact mice also enhanced spinal CaMKII autophosphorylation level, which was completely antagonized by clonidine. Moreover, direct PKA inhibition in CFA-injected mice mimicked the suppressive effect of α2 noradrenergic receptors on CaMKII. PKA inhibition has been shown to downregulate CaMKII by enhancing protein phosphatase activity. Consistent with this notion, spinal treatment with protein phosphatase inhibitor okadaic acid ruled out clonidine-mediated CaMKII dephosphorylation in CFA-injected mice. Through PKA/protein phosphatase/CaMKII pathway, clonidine noticeably decreased CFA-evoked phosphorylation of N-methyl-d-aspartate subtype glutamate receptor GluN1 and GluN2B subunit as well as α-amino-3-hydroxy-5-methylisoxazole-4-propionic Acid subtype glutamate receptor GluA1 subunit. These data suggested that interference with CaMKII signaling might represent an important mechanism underlying noradrenergic suppression of inflammatory pain.

[Immobilization remediation of Cd and Pb contaminated soil: remediation potential and soil environmental quality].

A pot experiment was conducted to investigate the immobilization remediation effects of sepiolite on soils artificially combined contamination by Cd and Pb using a set of various pH and speciation of Cd and Pb in soil, heavy metal concentration in Oryza sativa L., and soil enzyme activity and microbial quantity. Results showed that the addition of sepiolite increased the soil pH, and the exchangeable fraction of heavy metals was converted into Fe-Mn oxide, organic and residual forms, the concentration of exchangeable form of Cd and Pb reduced by 1.4% - 72.9% and 11.8% - 51.4%, respectively, when compared with the control. The contents of heavy metals decreased with increasing sepiolite, with the maximal Cd reduction of 39.8%, 36.4%, 55.2% and 32.4%, respectively, and 22.1%, 54.6%, 43.5% and 17.8% for Pb, respectively, in the stems, leaves, brown rice and husk in contrast to CK. The addition of sepiolite could improve the soil environmental quality, the catalase and urease activities and the amount of bacteria and actinomycete were increased to some extents. Although the fungi number and invertase activity were inhibited compared with the control group, it was not significantly different (P > 0.05). The significant correlation between pH, available heavy metal content, urease and invertase activities and heavy metal concentration in the plants indicated that these parameters could be used to evaluate the effectiveness of stabilization remediation of heavy metal contaminated soil.

[Adsorption of Cd2+ on biochar from aqueous solution].

Biomass-based materials such as biochar have a good performance in heavy metal adsorption. The adsorption of Cd2+ on biochar converted from cotton straw was studied. Adsorption isotherm, kinetics and effect factors such as temperature, pH and ionic strength were investigated. The adsorption of Cd2+ on biochar can be fitted by the Freundlich isotherm better than the Langmuir isotherm. The maximum adsorption amounts of Cd2+ at different temperatures were 9.738 mg x g(-1) (288.15 K), 10.14 mg x g(-1) (298.15 K), 10.40 mg x g(-1) (308.15 K) and 10.71 mg x g(-1) (318.15 K), respectively. The free energies AG(theta) were from -8.346 kJ x mol(-1) to -10.276 kJ x mol(-1) at different temperatures, indicating that the adsorption of Cd2+ onto biochar is spontaneous and is an endothermic process. The adsorption process can reach equilibrium within 40 minutes and can be fitted by the pseudo second order kinetic model. pH showed a significant effect on the adsorption of Cd2+ on biochar in the range of 2-8. The adsorption amount of Cd2+ on biochar shows a reducing trend with the increasing ionic strength.

[Effect and mechanism of immobilization of cadmium and lead compound contaminated soil using new hybrid material].

The effect of new hybrid material and its compound treatments with phosphate on immobilization of cadmium and lead in contaminated soil was investigated using a pot-culture experiment, and the immobilization mechanism of hybrid material was clarified through analysis of heavy metal fractions, sorption equilibration experiment and X-ray photoelectron spectroscopy (XPS). The single treatments of hybrid material could not significantly promote growth of Brassica chinensis, while the compound treatments of hybrid material and phosphate markedly increased dry biomass of shoots and roots, with maximal increases of 75.53% and 151.22%, respectively. Different hybrid material treatments could significantly reduce Cd and Pb concentrations in shoots, with maximal reductions of 66.79% and 48.62%, respectively, and the compound amendment treatments appeared more efficient than the single amendment treatments in reducing Cd and Pb uptake of B. chinensis. Different hybrid material treatments could significantly decrease concentrations of toxicity characteristic leaching procedure (TCLP) extractable Cd and Pb, and the compound hybrid material treatments appeared more efficient than the single treatments in reducing TCLP extractable Cd and Pb. Through the formation of bidentate ligand between metal ions and surface sulfhydryl by complexing reaction, the hybrid material could absorb and fix mobile fractions of Cd and Pb in soil, and promote transformation of acid extractable Cd and Pb into residual fraction, resulting in significant reduction of heavy metals bioavailability and mobility and then fixing remediation of contaminated soil. In summary, the compound treatment of hybrid material and phosphate is the most effective treatment for immobilization of Cd and Pb in contaminated soils, and the hybrid material inactivates Cd and Pb in soil mainly through special chemical adsorption.

[Effects of acid and heating treatments on the structure of sepiolite and its adsorption of lead and cadmium].

The effects of acid and heating treatment on the structure of sepiolite and its adsorption capacities for Pb2+ and Cd2+ were investigated using X-ray powder diffraction, infrared spectroscopy, surface area analyses and batch sorption experiments in this paper. The results showed that the BET surface area of the sepiolite samples grew with increase concentrations of HCl and prolong treatment time and no obvious structural changes were observed. CaCO3 as the impurity in the natural sepiolite can not be removed completely in the treatment process with 0.5 mol x L(-1) HCl. The surface area of sepiolite treated with 6 mol x L(-1) HCl and continuous stirring 72 h reached the maximum 301.47 m2 x g(-1). A decrease in the BET surface area was observed for the samples treated with acid at higher temperature. The BET surface area of samples treated with different acid species arranged in the order HCl > HNO3 > H2SO4. The calcinations process decreased the BET surface area from 21.44 m2 x g(-1) at 100 degrees C to 0.17 m2 x g(-1) at 900 degrees C. The adsorption results indicated that despite increases in the surface areas upon acid activation, improvements in the adsorption were not observed for heavy metal Pb2+ and Cd2+ ions. Pb2+ ions have higher affinity for specific adsorption onto the sepiolite samples than Cd2+ ions. H2SO4 treatment was found to be more effective for the removal of Pb2+ and Cd2+ ions than HCl and HNO3 treatments. It is apparent that PbSO4 and CdSO4 were formed during the sorption process. The calcinations treatment exhibited no significant effects on the adsorption of Pb2+ ions onto sepiolite, but the adsorption of Cd2+ ions obviously increased above 700 degrees C.