Effects of algal bloom (AB) on sediment microorganisms with special functions at different AB stages in Chaohu Lake.

Algal bloom (AB) is a serious water environment problem in China, but it is still unclear how AB affects microorganisms with special functions (such as nitrogen-, phosphorus-, sulfur- and iron-related bacteria) at different AB stages. Samples of water and sediment were taken in the AB region and free algal bloom (FAB) region of Chaohu Lake at different AB stages, and the numbers of N-, P-, S- and Fe-related bacteria were determined by culture-dependent methods. Results showed that during the whole experiment, numbers of N-, P-, S-, and Fe-related bacteria in the AB region were significantly higher than those in the FAB region, especially at the AB outbreak stage. In the FAB region, numbers of above bacteria showed little variation with time. In the AB region, however, numbers of N-, S-, and Fe-related bacteria evidently changed as 'Λ'-type with AB process. They presented an upward trend at the AB formation stage and the initial stage of AB outbreak, and then showed a downward trend. Numbers of P-related bacteria also showed a similar trend as the above bacteria, but they kept high level for long time at the AB outbreak stage. This study indicated that AB produced different effects on microorganisms with special functions at different AB stages.

Analysis of risk factors for medication-overuse headache relapse: a clinic-based study in China.

BACKGROUND: Medication overuse headache (MOH) is the third most prevalent headache type after migraine and tension-type headache. A large number of studies on the long-term prognosis have shown that MOH has a high relapse rate after treatment. Although MOH relapse-related risk factors have been reported, no related research has been performed in China. Therefore, the purpose of this study was to analyze and evaluate the risk factors for MOH relapse in China. METHODS: Eighty-six out-patients of Shandong Provincial Hospital who were initially diagnosed with MOH, and who had successful withdrawal treatment within 2 months, were chosen from March 2012 to July 2013. All subjects were followed up by the investigators of this study. Of the 86 subjects, 27 who had relapsed were compared with 59 who had not relapsed (i.e. the controls). Based on a standardized questionnaire, a database was created (with Microsoft Excel 2010). The data, which included 38 indexes, were analyzed by univariate analysis with chi-square test, Fisher's exact test, t-test, or paired rank test. The statistically correlated (P<0.05) variables were chosen as the independent variables, thereby enabling the calculation of the non-conditional multivariate stepwise logistic regression. RESULTS: The independent risk factors for medication-overuse headache relapse were determined as headache frequency before drug withdrawal, duration of primary headache, and headache frequency after drug withdrawal. CONCLUSION: Headache frequency before drug withdrawal, duration of primary headache, and headache frequency after drug withdrawal may be the independent risk factors for MOH relapse in China.

Water-dispersible, pH-stable and highly-luminescent organic dye nanoparticles with amplified emissions for in vitro and in vivo bioimaging.

A new strategy is presented for using doped small-molecule organic nanoparticles (NPs) to achieve high-performance fluorescent probes with strong brightness, large Stokes shifts and tunable emissions for in vitro and in vivo imaging. The host organic NPs are used not only as carriers to encapsulate different doped dyes, but also as fluorescence resonance energy transfer donors to couple with the doped dyes (as acceptors) to achieve multicolor luminescence with amplified emissions (AE). The resulting optimum green emitting NPs show high brightness with quantum yield (QY) of up to 45% and AE of 12 times; and the red emitting NPs show QY of 14% and AE of 10 times. These highly-luminescent doped NPs can be further surface modified with poly(maleic anhydride-alt-1-octadecene)-polyethylene glycol (C18PMH-PEG), endowing them with excellent water dispersibility and robust stability in various bio-environments covering wide pH values from 2 to 10. In this study, cytotoxicity studies and folic acid targeted cellular imaging of these multicolor probes are carried out to demonstrate their potential for in vitro imaging. On this basis, applications of the NP probes in in vivo and ex vivo imaging are also investigated. Intense fluorescent signals of the doped NPs are distinctly, selectively and spatially resolved in tumor sites with high sensitivity, due to the preferential accumulation of the NPs in tumor sites through the passive enhanced permeability and retention effect. The results clearly indicate that these doped NPs are promising fluorescent probes for biomedical applications.

Effects of elevated O3 on microbes in the rhizosphere of mycorrhizal snap bean with different O3 sensitivity.

Elevated ozone (O3) generally affects microbial biomass and community structure in rhizosphere, but these effects are unclear in mycorrhizal plants because arbuscular mycorrhizal (AM) fungi often benefit microbial growth in the rhizosphere. Here, we investigate the effects of elevated O3 on microbial biomass and community structure in the rhizosphere of mycorrhizal snap bean (Phaseolus vulgaris L.) with different O3 sensitivity (R123: O3-tolerant plant; S156: O3-sensitive plant) based on the phospholipid fatty acids (PLFAs) method. Compared with ambient O3, elevated O3 significantly decreased mycorrhizal colonization rates in the 2 genotypes, especially in S156 plants. The wet masses of shoot and root were decreased by elevated O3 in the 2 genotypes independent of AM inoculation, but they were higher in the mycorrhizal plant than in the nonmycorrhizal plant independent of O3 concentration. Elevated O3 significantly decreased the relative proportion of specific fungal PLFAs in the nonmycorrhizal plant, but this effect disappeared in the mycorrhizal plant. The relative proportions of specific PLFAs of other microbial groups (Gram-positive, Gram-negative, and actinomycete) in the rhizosphere and all specific PLFAs in the hyphosphere were not affected by elevated O3 independent of AM inoculation. In the rhizosphere of the 2 genotypes, microbial community structure was changed by AM inoculation and elevated O3 as well as by their interaction; in the hyphosphere, however, microbial community structure was changed by elevated O3 only in R123 plants. It is concluded that AM inoculation can offset negative effect of elevated O3 on fungal biomass but seems to enhance shift of microbial community structure in rhizosphere under elevated O3.

Controllable synthesis of 6H-1,4-diazepine-2,3-dicarbonitrile nanocrystals and their optical properties.

Organic nanostructures of 6H-1,4-Diazepine-2,3-dicarbonitrile (HDD) ranging from nanoparticles to nanoribbons have been controllably prepared. Changes in morphologies are observed to be accompanied with changes in optical properties. The HDD nanoparticles show a main emission at ca. 710 nm with a very weak shoulder at 625 nm, as nanoparticles gradually grow into nanoribbons, the predominant emission shifts to be centered at 625 nm at the expense of that at 710 nm. Shifts in the emission are proposed to come from different charge distributions of highest occupied molecular orbits (HOMO) induced by changing of intermolecular interactions, which is also evidenced by the quantum mechanics calculations.

Hemorrhage-Induced Sphingosine Kinase 1 Contributes to Ferroptosis-Mediated Secondary Brain Injury in Intracerebral Hemorrhage.

The pathogenic processes of brain injury after intracerebral hemorrhage (ICH) have not yet been fully elucidated. Increasing evidence suggests that ferroptosis activation aggravates injury after ICH, but the underlying mechanism remains unclear. Sphingosine kinase 1 (Sphk1) is a key enzyme in the regulation of sphingosine metabolism involved in the ferroptosis pathway, but its role in ICH needs clarification. In this study, transcriptional changes in ICH patients were assessed by microarray data, exposing Sphk1 as a highly upregulated gene during ICH. Furthermore, Sphk1 chemical inhibitors and siRNA were used to inhibit ICH-induced Sphk1 upregulation in in vivo and in vitro models, showing that Sphk1 inhibition after protects against ferroptosis and attenuates secondary brain injury and cell death. Mechanistically, this study unveiled that sphingosine kinase 1/sphingosine 1-phosphate/extracellular-regulated protein kinases/phosphorylated extracellular-regulated protein kinases (Sphk1/S1p/ERK/p-ERK) pathway is responsible for regulation of ferroptosis leading to secondary brain injury and cell death following ICH. Collectively, this study demonstrates that ferroptosis is closely associated with ICH, and that Sphk1 has a critical role in this lethal process. These results suggest a novel unique and effective therapeutic approach for ICH prevention and treatment.

Induced Pluripotent Stem Cell-Derived Dopaminergic Neurons from Familial Parkinson's Disease Patients Display α-Synuclein Pathology and Abnormal Mitochondrial Morphology.

Accumulation of α-synuclein (α-syn) into Lewy bodies (LBs) and mitochondrial abnormalities are the two cardinal pathobiological features of Parkinson's disease (PD), which are associated with the loss of dopaminergic neurons. Although α-syn accumulates in many different cellular and mouse models, these models generally lack LB features. Here, we generated midbrain dopaminergic (mDA) neuronal cultures from induced pluripotent stem cells (iPSCs) derived from familial PD (fPD) patients and healthy controls. We show that mDA neuronal cultures from fPD patients with A53T mutation and α-syn gene (SNCA) triplication display pathological α-syn deposits, which spatially and morphologically resemble LBs. Importantly, we did not find any apparent accumulation of pathological α-syn in mDA neuronal culture derived from a healthy donor. Furthermore, we show that there are morphological abnormalities in the mitochondrial network in mDA neuronal cultures from fPD patients. Consequently, these cells were more susceptible to mitochondrial damage compared with healthy donor-derived mDA neuronal cultures. Our results indicate that the iPSC-derived mDA neuronal culture platform can be used to investigate the spatiotemporal appearance of LBs, as well as their composition, architecture, and relationship with mitochondrial abnormalities.

Glutathione alleviates acute intracerebral hemorrhage injury via reversing mitochondrial dysfunction.

Glutathione (GSH) has been studied for its neuroprotection value in several diseases, but the effect of GSH on intracerebral hemorrhage (ICH) is unclear. In this study, we examined the protective effects of GSH in an experimentally induced ICH model and investigated the relative mechanisms. Adult male C57BL/6j mice were randomized into Sham, ICH and GSH treatment groups. GSH was injected with the dose of 50, 100 or 200 mg/kg once per day for 3 days, starting immediately after operation. The results revealed a GSH-mediated improvement of neurological deficits score (NDS), motor and sensory functions impairment in a dose-dependent manner three days post ICH (p < 0.01, GSH 200 vs ICH. Sham, n = 12; ICH, n = 9; GSH 50, n = 10; GSH 100, n = 10; GSH 200, n = 11) in addition to significantly reduced mortality rate (p = 0.2632, GSH 200 vs ICH. n = 12 per group) and damage volume (p < 0.05, GSH 200 vs ICH. n = 12 per group). GSH treatment also attenuated injury measured by decreased brain edema (p < 0.05, GSH 200 vs ICH. Sham, n = 10; ICH, n = 10; GSH 200, n = 12), blood-brain barrier disruption (p < 0.05, GSH 200 vs ICH. Sham, n = 10; ICH, n = 10; GSH 200, n = 12), and histopathological damage (p < 0.05, GSH 200 vs ICH. Sham, n = 6; ICH, n = 6; GSH 200, n = 8) 72 h after ICH. In addition, GSH treatment also decreased cell apoptosis (p < 0.01, GSH 200 vs ICH. Sham, n = 6; ICH, n = 6; GSH 200, n = 8) and resulted in up-regulated protein expression of complex I (p < 0.01, GSH 200 vs ICH. Sham, n = 6; ICH, n = 6; GSH 200, n = 8), which was consistent with an overall up-regulation of complex I function in mitochondria using Oxygraph-2 K high resolution respirometry (p < 0.05, GSH 200 vs ICH. Sham, n = 4; ICH, n = 5; GSH 200, n = 6). In conclusion, GSH effectively improved the prognosis of ICH mice by attenuating neurological impairment, decreasing neural damage, and inhibiting apoptosis. The neuroprotection by GSH resulted from the up-regulation of mitochondrial oxidative respiration function. The results of our study suggest that GSH can be a potential therapeutic agent for ICH.

Synthesis of butyl oleate catalyzed by cross-linked enzyme aggregates with magnetic nanoparticles in rotating magneto-micro-reactor.

In order to increase application of cross-linked enzyme aggregates (CLEAs) in industry production, a novel micro-reactor system that included a rotating magnetic field (RMF), a micro-reactor and CLEAs with magnetic nanoparticles (M-CLEAs) was designed to synthesize butyl oleate. Result showed that the presence of RMF significantly increased the yield of butyl oleate and the maximum increment was 23%. The yield of butyl oleate was impacted by the dosage and distribution of M-CLEAs in micro-reactor. M-CLEAs showed good reusability, since the morphology and the second structure of protein of M-CLEAs did not show evident change after 4 operative cycles. Although the three-dimensional fluorescence of M-CLEAs showed shift in fluorescence intensity and the maximum emission wavelengths, the yield of butyl oleate was not affected. This study provides a novel design that realized efficient, convenient and continuous application of CLEAs in biosynthesis, and M-CLEAs also show good promises in industry production.

Analysis on the risk factors of medication-overuse headache in Chinese patients.

OBJECTIVE: The purpose of this study was to analyze the risk factors of medication-overuse headache in patients with chronic migraine in China. MATERIALS AND METHODS: 157 patients who were diagnosed as chronic migraine were chosen from headache outpatients of Shandong Provincial Hospital affiliated to Shandong University. Based on a standardized questionnaire, a database was developed and analyzed with 45 indexes. RESULTS: The independent risk factors of medication-overuse headache identified in this study included the frequency of medicine overuse (OR = 9.575, 95%CI, 3.573-35.659), Allodynia Symptom Checklist scores (OR = 5.846, 95%CI, 2.065-22.856), anxiety disorder (OR = 2.902, 95%CI, 1.601-7.476) and lack or non- standardized preventive treatment (OR = 1.173, 95%CI, 1.073-3.826). CONCLUSIONS: The frequency of medicine overuse, Allodynia Symptom Checklist scores, anxiety disorder and lack or non-standardized preventive therapy were the independent risk factors for medication-overuse headache in patients with chronic migraine.

Changes in hormones of the hypothalamic-pituitary-gonadal axis in migraine patients.

The incidence of migraine is higher in women than in men. Abnormality of the hypothalamus-pituitary-gonadal (HPG) axis is believed to be implicated in the pathogenesis of migraine. The aim of this study was to detect serum hormone levels in the HPG axis of migraineurs and analyze the relationship between the hormone levels and migraine-related clinical characteristics. One hundred and nineteen migraineurs were enrolled. Serum FSH, LH, estradiol, progesterone, testosterone, prolactin and GnRH was detected. Pain intensity and migraine-related disability were evaluated using the visual analogue scale (VAS) and the Migraine Disability Assessment questionnaire (MIDAS). The relationships between sex hormone levels and the VAS score and the MIDAS score were also examined. Progesterone levels in male migraineurs were lower than those in healthy controls (P < .01). In female patients, in the follicular phase, testosterone levels were lower than in healthy controls (P < .01). In the luteal phase, estrogen and testosterone levels (P < .05) were lower than in healthy controls. Progesterone and testosterone levels (P < .01) were lower than in healthy controls in the postmenopausal phase. In male patients, estrogen levels were negatively associated with the MIDAS score (r = -0.602). In female patients, in the follicular phase, estrogen levels were positively correlated with headache duration and VAS score (r = 0.374, r = 0.331, respectively) and negatively related with MIDAS score (r = -0.334). In the luteal phase, estrogen and progesterone levels were negatively correlated with the MIDAS score (r = -0.772, r = -0.464, respectively). The levels of HPG axis hormones were abnormal in migraineurs and were associated with migraine-related clinical characteristics.

Effects of algal bloom formation, outbreak, and extinction on heavy metal fractionation in the surficial sediments of Chaohu Lake.

The effects of algal bloom (AB) on the physicochemical and biochemical properties of water and sediment in lakes have been widely studied. However, limited attention has been directed toward the effects of the processes of AB formation, outbreak, and extinction on heavy metal fractionation in sediment. In this study, water and sediment samples were collected from the AB and free algal bloom (FAB) regions of Chaohu Lake from May to September in 2012. The chemical fractionation of seven heavy metals (Cd, Cr, Cu, Mn, Ni, Fe, and Pb) in sediment was determined by using a modified three-step sequential procedure. Evident processes of AB formation, outbreak, and extinction were observed in the AB region, but not in the FAB region. The TN and TP concentrations in water and sediment in the AB region were significantly higher than those in the FAB region. The water DO concentration was higher in the AB region than that in the FAB region before the early stage of the AB outbreak, but an opposite trend was observed in the stages that followed. Metal fractionation in sediment showed that except for Mn and Cu, the majority of metals were in the residual fraction regardless of the AB process. The AB process slightly altered the concentrations of metal fractions, except for reducible Fe and oxidizable Cu. The result showed that AB formation, outbreak, and extinction slightly affected heavy metal fractionation in sediment though water properties were significantly different among AB processes.

[Effects of outbreak and extinction of algal blooms on the microbial community structure in sediments of Chaohu Lake].

Although impacts of algal bloom on the physicochemical and biological properties of water and sediment in many lakes have been largely studied, less attention is paid to the impact of outbreak and extinction of algal blooms on the microbial community structure in sediment. In this study, outbreak and extinction of algal blooms and their effects on the microbial community structure in sediment of Chaohu Lake were studied by PCR-DGGE method. The results showed that algal blooms formed between May 15 and June 20, sustained from June 20 to September 5, and then went into extinction. In the region without algal blooms, PCR-DGGE analysis showed that microbial species, Shannon-Wiener diversity index and Simpson dominance index changed slightly over time; moreover, the microbial community structure had high similarity during the whole study. Temperature may be the main factor affecting the fluctuation of the microbial community structure in this region. In the region with algal blooms, however, microbial species and Shannon-Wiener diversity index were higher during the formation and extinction of algal blooms and lower in the sustaining blooms stage than those in the region without algal blooms. But the Simpson dominance index showed the opposite trend over time. In addition, the microbial community structure had low similarity during the whole study. The results suggested that outbreak and extinction of algal blooms produced different effects on the microbial community structure and the dominant microbial species, which may be related to the variation of water properties caused by temperature and algal blooms. This study showed that outbreak and extinction of algal blooms caused different effects on microbes in lake sediment, and this is significantly important to deeply evaluate the effects of algal bloom on the aquatic ecosystem of the lake and effectively control algal blooms using sediment microbes.

[Effects of enhanced CO2 fertilization on phytoremediation of DEHP-polluted soil].

Low efficiency of remediation is one of the key issues to be solved in phytoremediation technology. Based on the necessity of reducing CO2 emission in China and the significance of CO2 in plant photosynthesis, this paper studied the effects of enhanced CO2 fertilization on the phytoremediation of polluted soil, selecting the C3 plant mung bean (Vigna radiate) and the C4 plant maize (Zea mays) as test plants for phytoremediation and the DEHP as the target pollutant. DEHP pollution had negative effects on the growth and rhizosphere micro-environment of the two plants. After enhanced CO2 fertilization, the aboveground dry mass of the two plants and the alkaline phosphatase activity in the rhizosphere soils of the two plants increased, the COD activity in the leaves of the two plants decreased, the microbial community in the rhizosphere soils shifted, and the numbers of the microbes with DEHP-tolerance in the rhizosphere soils increased. These changes indicated that enhanced CO2 fertilization could promote the plant growth and the plant tolerance to DEHP stress, and improve the rhizosphere micro-environment. Enhanced CO2 fertilization also increased the DEHP uptake by the two plants, especially their underground parts. All these effects induced the residual DEHP concentration in the rhizospheres of the two plants, especially that of mung bean, decreased obviously, and the phytoremediation efficiency increased. Overall, enhanced CO2 fertilization produced greater effects on C3 plant than on C4 plant. It was suggested that enhanced CO2 fertilization could be a useful measure to enhance the efficiency of phytoremediation.

[Canonical correspondence analysis between phytoplankton community and environmental factors in macrophtic lakes of the middle and lower reaches of Yangtze River].

The phytoplankton communities in 4 macrophtic lakes (Longgan Lake, Liangzi Lake, Futou Lake and Baoan Lake) in Middle-Lower Yangtze Plain were investigated in September 2011, and 7 phylum and 231 species of phytoplankton were detected in the waters. The results indicated that phytoplankton was mainly composed of Cyanophyta, Bacillariophyta and Chlorophyta. The four lakes were mesotrophic. And the main phytoplankton was Phormidium foveolarum, Synedra ulna, Phormidium tenu and Tribonema minus. The relationships between the distribution of phytoplankton and environmental factors in each sampling site were studies by canonical correspondence analysis. The results demonstrated that pH and Total phosphorus are the key factors for the distribution of phytoplankton communities in 4 typical macrophtic lakes in Middle-Lower Yangtze Plain.

[Allelopathic effect of Nelumbo nucifera stem and leaf tissue extract on the growth of Microcystis aeruginosa and Scenedesmus quadricanda].

Effects of Nelumbo nucifera stem and leaf tissue extract on the growth of Microcystis aeruginosa and Scenedesmus quadricanda were studied to verify its potential in entriphication control. Five concentrations of Nelumbo nucifera stem and leaf tissue extract were chosen to compare their inhibitory effects on the growth of Microcystis aeruginosa and Scenedesmus quadricanda. The result showed that the leaf extract inhibited the algae bloom more effectively than the stem extract on the whole. When the leaf extract normality was 25 g x L(-1), the highest inhibition rate of Microcystis aeruginosa and Scenedesmus quadricanda was 71.33% and 78.14%, respectively, while for the stem extract, the values were 49.78% and 52.14%. Propanamide was found in both the stem and leaf tissue extracts of Nelumbo nucifera by GC-MS analysis, with concentrations of 1.1 mg x L(-1) and 0.2 mg x L(-1), respectively. The EC50 values of the two kinds of algae were calculated by the probability method.

[Strategies of nutrients control in lakes based on ecoregions of lakes in China].

In order to better reduce lake eutrophication, based on five ecoregions of lakes, the relationships of total nitrogen (TN), total phosphorus (TP), and TN/TP ratio with chlorophyll-a (Chl-a) in 100 lakes were discussed, furthermore, strategies of nutrient control were proposed respectively. Results showed that among the five ecoregions, the lake eutrophication level was the lowest in Dongbei ecoregion and the highest in Huabei ecoregion, but the eutrophication level in lakes of all the five ecoregions is increasing in recent years. Algal growth in lakes of Dongbei and Huabei ecoregions was limited by phosphorus, while it was simultaneously limited by nitogen and phosphorus in lakes of other three ecoregions (Zhongdongbu, Yungui and Mengxin). In lakes with TN/TP < 10, significant correlation between Chl-a concentration and TN was found in lakes of the five ecoregions except for Huabei ecoregion, and significant correlation between Chl-a concentration and TP was found in lakes of Dongbei and Mengxin ecoregions. In lakes with TN/TP > 17, significant correlation between Chl-a concentration and TP was found in lakes of the five ecoregions except for Mengxin ecoregion, and significant correlation between Chl-a concentration and TN was found in lakes of Zhongdongbu, Yungui and Mengxin ecoregions. In lakes with 10 < TN/TP < 17, no significant correlation between Chl-a and TN (or TP) was found in lakes of all ecoregions except for Zhongdongbu ecoregion where Chl-a concentration was significantly affected by TN. As for strategies of nutrient control and reduction in the five ecoregions, lakes of Huabei ecoregion should adopt TP control in priority, and in Dongbei ecoregion, TP and TN should be controlled simultaneously in lakes with TN/TP < 10, while other lakes should focus on TP control. Lakes in other three ecoregions (Zhongdongbu, Mengxin and Yungui) should control TP and TN simultaneously.

[Effect of elevated O3 on the arbuscular mycorrhizal (AM) structure and glomalin production in two genotypes of snap bean].

In an environment with simulated elevated atmospheric ozone, two genotypes of snap bean (Phaseolus vulgaris L.) that differed in O3 sensitivity (O3-sensitive: S156; O3-tolerant: R123) were selected as host plants for arbuscular mycorrhizal (AM) fungi. The objective was to investigate the effect of elevated O3 on the AM structure and glomalin production in two genotypes, and to understand the effect of elevated O3 the growth of AM fungi and formation of AM structure. The results showed that in comparison with ambient O3 (20 nL x L(-1)), elevated O3 (70 nL x L(-1)) significantly decreased the mycorrhizal colonization rate in both genotypes, particularly the S156 plant (decreased by 43.6%). Elevated O3 exposed a great negative effect on the AM structure in both genotypes. For example, the arbuscule number per unit root, and the length of external hyphae in root compartment and hyphal compartment were significantly decreased, especially in S156 plant. However, the effect of elevated atmospheric O3 was not significant on the vesicule number per unit root in both genotypes. Total glomalin production in mycorrhizosphere and hyphosphere of both genotypes was only slightly affected by elevated O3, however, the production of easily extractable glomalin was significantly increased. In addition, no evident difference in glomalin concentration was observed between two genotypes at either ambient O3 or elevated O3. This study showed that the mycorrhizal colonization rate, AM structure and production of easily extractable glomalin gave great response to elevated O3 especially in the O3-sensitive plant.

[Effect of CO2 fertilization on residual concentration of cypermethrin in rhizosphere of C3 and C4 plant].

In order to achieve sustainable economic and environmental development in China, CO2-emission reduction and phytoremediation of polluted soil must be resolved. According to the effect of biological carbon sequestration on rhizosphere microenvironment, we propose that phytoremediation of polluted soil can be enhanced by CO2 fertilization, and hope to provide information for resolving dilemma of CO2-emission reduction and phytoremediation technology. In this study, effects of CO2 fertilization on cypermethrin reduction in rhizosphere of C3-plant (bush bean) and C4-plant (maize) were investigated. Results showed that dry weight of shoot and root of bush bean (C3 plant) was increased by CO2 fertilization. Relative to ambient CO2, dry weight of root was increased by 54.3%, 31.9% and 30.0% in soil added with 0, 20 and 40 mg x kg(-1) cypermethrin respectively. Microbial biomass was increased by CO2 fertilization in rhizosphere soil added with 0 mg x kg(-1) cypermethrin, but negative effect was found in rhizosphere soil added with 20 and 40 mg x kg(-1) cypermethrin. CO2 fertilization slightly affected residual concentration of cypermethrin in rhizosphere soil added with 0 mg x kg(-1) cypermethrin, but significantly decreased residual concentration of cypermethrin as 24.0% and 16.9% in soil added with 20 and 40 mg x kg(-1) relative to ambient CO2. In maize plant, however, plant growth, microbial biomass and residual cypermethrin concentration in rhizosphere was slightly affected by CO2 fertilization, and even negative effect was observed. This study indicated that CO2 fertilization decreases the residual concentration of cypermethrin in rhizosphere of C3-plant, and it is possible to enhance phytoremediation of organic-polluted soil by C3-plant through CO2 fertilization. However, further study is needed for C4-plant.

Carrier-free, water dispersible and highly luminescent dye nanoparticles for targeted cell imaging.

We develop a new strategy of using surface functionalized small molecule organic dye nanoparticles (NPs) for targeted cell imaging. Organic dye (2-tert-butyl-9,10-di(naphthalen-2-yl)anthracene, TBADN) was fabricated into NPs and this was followed by surface modification with an amphipathic surfactant poly(maleic anhydride-alt-1-octadecene)-polyethylene glycol (C18PMH-PEG) through hydrophobic interactions to achieve good water dispersibility and bio-environmental stability. It should be noted that no additional inert materials were added as carriers, thus the dye-loading capacity of the resulting TBADN NPs is obviously higher than those of previously reported carrier-based structures. This would lead to much larger absorption and then much higher brightness. The resulting TBADN NPs possess comparable, if not higher, brightness than CdSe/ZnS quantum dots under the same conditions, with favorable biocompatibility. Significantly, TBADN NPs are readily conjugated with folic acid, and successfully applied in targeted cell imaging. These results show that water dispersible and highly stable organic NPs would be a promising new class of fluorescent probe for bioapplications in cellular imaging and labeling. This strategy may be straightforwardly extended to other organic dyes to achieve water dispersible NPs for cell imaging and drug delivery.