Mitigated membrane fouling of anammox membrane bioreactor by microbiological immobilization

In this study, membrane fouling behavior of anammox MBR with or without carriers made by magnetic porous carbon microspheres was investigated. The results show that Trans Membrane Pressure was an order of magnitude lower after 50days due to use of carriers, which did not directly contact with membrane surface. Scanning Electron Microscope analysis indicates that abundance of anammox bacteria formed biofilm on membrane surface. Fourier transform infrared spectroscopy combined with amino acids contents analysis for membrane surface deposition show that metabolite released by anammox bacteria contains more hydrophobic groups than hydrophilic, which was considered as important reason for its abundant existence on hydrophobic membrane surface. Microbiological immobilization not only reduces biological membrane fouling, but also mitigates organic fouling including organic matter containing COO, hydrophobic groups (CH3, CH2 and CH etc), as well as inorganic deposition. Our finding provides an effective method for mitigating MBR membrane fouling in anammox process.

A comprehensive analysis of NDST3 for schizophrenia and bipolar disorder in Han Chinese

A novel susceptibility locus (rs11098403) for schizophrenia and bipolar disorder (BD) was identified in an Ashkenazi Jewish population by a recent large-scale genome-wide association study. The rs11098403 is located in the vicinity of the gene encoding N-deacetylase/N-sulfotransferase (heparan glucosaminyl) 3, (NDST3). This study aimed to replicate the results in a Han Chinese population and then potentially extend these findings. We performed a two-stage study to investigate the association of NDST3 with the schizophrenia and BD risk in the Han Chinese. In stage 1, a total of 632 patients with schizophrenia, 654 patients with BD and 684 healthy controls were recruited from the Shanghai region. In stage 2, 522 schizophrenia patients and 547 normal subjects were enrolled from the Hangzhou region. Then, we conducted a meta-analysis based on the present literature. In stage 1, the single nucleotide polymorphism (SNP) rs11098403 showed a significant association with schizophrenia (corrected P=0.005). The frequency of the rs11098403 G allele was significantly lower among schizophrenia patients than among the controls (odds ratio (OR)=0.68, 95% confidence interval (CI): 0.55-0.84, corrected P=0.002). No significant difference was observed in individual SNP marker genotypes or allele distributions between the BD and control groups. In stage 2, the association of rs11098403 with schizophrenia could be validated (genotypic P=0.001 and allelic P=0.0003). After pooling all data from 1861 patients with schizophrenia and 2081 controls, we observed a significant association of the rs11098403 G allele with schizophrenia (Z=5.56, P<0.001), with an OR=0.70 (95% CI: 0.61-0.79). Then, we performed an expression quantitative trait loci analysis to investigate the functional effect of rs11098403 on NDST3 expression in the brain. We observed a significant association of rs11098403 with NDST3 expression in the hippocampus (P=0.027), although the significance did not survive after multiple testing correction. Our findings provided preliminary evidence that rs11098403 might modify the genetic risk of schizophrenia in the Han Chinese. Further investigations are warranted to identify the precise mechanism regulating brain NDST3 expression in the Han Chinese. These results would help to explain the pathophysiological mechanism of schizophrenia.

Cotransport of bacteria with hematite in porous media: Effects of ion valence and humic acid

This study investigated the influence of multiple colloids (hematite and humic acid) on the transport and deposition of bacteria (Escherichia coli) in packed porous media in both NaCl (5 mM) and CaCl2 (1 mM) solutions at pH 6. Due to the alteration of cell physicochemical properties, the presence of hematite and humic acid in cell suspensions significantly affected bacterial transport and deposition in quartz sand. Specifically, the presence of hematite (5 mg/L) decreased cell transport (increased cell deposition) in quartz sand in both NaCl and CaCl2 solutions, which could be attributed to the less negative overall zeta potentials of bacteria induced by the adsorption of positively charged hematite onto cell surfaces. The presence of a low concentration (0.1 mg/L) of humic acid in bacteria and hematite mixed suspensions reduced the adsorption of hematite onto cell surfaces, leading to increased cell transport in quartz sand in NaCl solutions, whereas, in CaCl2 solutions, the presence of 0.1 mg/L humic acid increased the formation of hematite-cell aggregates and thus decreased cell transport in quartz sand. When the concentration of humic acid was increased to 1 mg/L, enhanced cell transport was observed in both NaCl and CaCl2 solutions. The decreased adsorption of hematite onto cell surfaces as well as the competition of deposition sites on quartz sand with bacteria by the suspended humic acid contributed to the increased cell transport.

Ordered RTiO2@ATiO2 architecture for dye-sensitized solar cell applications

R_TiO2@A_TiO2 architectures are constructed, in which 1D rutile TiO₂ (R_TiO2) arrays allow a fast electron transport and branched anatase TiO₂ (A_TiO2) particles benefit the dye harvesting.

LSER model for organic compounds adsorption by single-walled carbon nanotubes: Comparison with multi-walled carbon nanotubes and activated carbon

LSER models for organic compounds adsorption by single and multi-walled carbon nanotubes and activated carbon were successfully developed. The cavity formation and dispersion interactions (vV), hydrogen bond acidity interactions (bB) and π-/n-electron interactions (eE) are the most influential adsorption mechanisms. SWCNTs is more polarizable, less polar, more hydrophobic, and has weaker hydrogen bond accepting and donating abilities than MWCNTs and AC. Compared with SWCNTs and MWCNTs, AC has much less hydrophobic and less hydrophilic adsorption sites. The regression coefficients (e, s, a, b, v) vary in different ways with increasing chemical saturation. Nonspecific interactions (represented by eE and vV) have great positive contribution to organic compounds adsorption, and follow the order of SWCNTs > MWCNTs > AC, while hydrogen bond interactions (represented by aA and bB) demonstrate negative contribution. These models will be valuable for understanding adsorption mechanisms, comparing adsorbent characteristics, and selecting the proper adsorbents for certain organic compounds.

Subcellular mechanism of Escherichia coli inactivation during electrochemical disinfection with boron-doped diamond anode: A comparative study of three electrolytes

Although the identification of effective oxidant species has been extensively studied, yet the subcellular mechanism of bacterial inactivation has never been clearly elucidated in electrochemical disinfection processes. In this study, subcellular mechanism of Escherichia coli inactivation during electrochemical disinfection was revealed in terms of comprehensive factors such as cell morphology, total organic components, K(+) leakage, membrane permeability, lipid peroxidation, membrane potential, membrane proteins, intracellular enzyme, cellular ATP level and DNA. The electrolysis was conducted with boron-doped diamond anode in three electrolytes including chloride, sulfate and phosphate. Results demonstrated that cell inactivation was mainly attributed to damage to the intracellular enzymatic systems in chloride solution. In sulfate solution, certain essential membrane proteins like the K(+) ion transport systems were eliminated. Thus, the pronounced K(+) leakage from cytosol resulted in gradual collapse of the membrane potential, which would hinder the subcellular localization of cell division-related proteins as well as ATP synthesis and thereby lead to the bacterial inactivation. Remarkable lipid peroxidation was observed, while the intracellular damage was negligible. In phosphate solution, the cells sequentially underwent overall destruction as a whole cell with no captured intermediate state, during which the organic components of the cells were mostly subjected to mineralization. This study provided a thorough insight into the bacterial inactivation mechanism on the subcellular level.

Effect of inorganic nanoparticles on 17β-estradiol and 17α-ethynylestradiol adsorption by multi-walled carbon nanotubes

With extensive application of diverse engineered nanoparticles (NPs), multiple NPs would inevitably be released into the environment. However, much emphasis in most previous studies on the interactions of pollutants with NPs has been placed on only one type of NPs at a time. This study investigated the impact of inorganic NPs (I-NPs) on the adsorption of 17β-estradiol (E2) and 17α-ethynylestradiol (EE2) by multi-walled carbon nanotubes (CNTs). The presence of I-NPs inhibited the adsorption and increased the equilibrium time of E2 and EE2 by CNTs. Moreover, the effect of Al2O3 was stronger than that of SiO2, because electrostatic attraction enhanced the interaction between oppositely charged Al2O3 and CNTs. The addition sequence of I-NPs and pollutant also influences adsorption. This is among the first studies investigating the effect of I-NPs on pollutants adsorption by CNTs, which is useful for understanding the transport and fate of CNTs and contaminants in natural aquatic systems.

Dual-Enhanced Photocatalytic Activity of Fe-Deposited Titanate Nanotubes Used for Simultaneous Removal of As(III) and As(V)

Fe-deposited titanate nanotubes (Fe-TNTs) with high photocatalytic activity and adsorptive performance were synthesized through a one-step hydrothermal method. Initial As(III) oxidation followed by As(V) adsorption by Fe-TNTs could simultaneously remove these two toxic pollutants from aqueous solutions. The apparent rate constant value for photo-oxidation of As(III) under UV irradiation by Fe-TNTs was almost 250 times that of unmoidified TNTs. Under visible light, the Fe-TNTs also exhibited enhanced photocatalytic activity after Fe was deposited. Fe3+ located in the interlayers of TNTs acted as temporary electron- or hole-trapping sites, and attached α-Fe2O3 played the role of a charge carrier for electrons transferred from TNTs. These two effects inhibited electron-hole pair recombination thus promoting photocatalysis. Moreover, the As(V) adsorptive performance of Fe-TNTs also improved, owing to the presence of additional adsorption sites, α-Fe2O3, as well as increased pHPZC. Furthermore, Fe-TNTs exhibited good photocatalytic and adsorptive performace even after 5 reuse cycles. The present tests, concerning an initial As(III) photocatalysis and subsequent As(V) adsorption process, highlight the feasibility and importance of Fe used to modify TNTs. This study proposes a feasible method to simultaneously remove As(III) and As(V) from contaminated water using a novel Ti-based nanomaterial.

Microbial reduction and precipitation of vanadium (V) in groundwater by immobilized mixed anaerobic culture

Vanadium is an important contaminant impacted by natural and industrial activities. Vanadium (V) reduction efficiency as high as 87.0% was achieved by employing immobilized mixed anaerobic sludge as inoculated seed within 12h operation, while V(IV) was the main reduction product which precipitated instantly. Increasing initial V(V) concentration resulted in the decrease of V(V) removal efficiency, while this index increased first and then decreased with the increase of initial COD concentration, pH and conductivity. High-throughput 16S rRNA gene pyrosequencing analysis indicated the decreased microbial diversity. V(V) reduction was realized through dissimilatory reduction process by significantly enhanced Lactococcus and Enterobacter with oxidation of lactic and acetic acids from fermentative microorganisms such as the enriched Paludibacter and the newly appeared Acetobacterium, Oscillibacter. This study is helpful to detect new functional species for V(V) reduction and constitutes a step ahead in developing in situ bioremediations of vanadium contamination.

Metabolic syndrome is an independent prognostic factor for endometrial adenocarcinoma

OBJECTIVE

To study the association between metabolic syndrome (MS) and the prognosis of patients with endometrial adenocarcinoma.

METHODS

A total of 385 patients with endometrial adenocarcinoma in the Department of Gynecologic Oncology, at the Zhejiang Cancer Hospital in China, between January 2001 and December 2008 were chosen. The deadline for the completion of follow-up was December 2013. The overall survival (OS) of the patients with MS was analyzed by the Kaplan-Meier method. Various clinical characteristics (e.g., clinical and surgical stage, vascular invasion, histological grade, tumor size, age at start of the first treatment, and lymphatic metastasis) related to the prognosis of endometrial adenocarcinoma were also evaluated.

RESULTS

A univariate analysis demonstrated that the OS rate of the patients with endometrial adenocarcinoma with MS was significantly worse than that of the patients without MS for all 385 patients (P = 0.001). Multivariate Cox proportional hazards regression analyses showed that stage (P = 0.001), lymphatic metastasis (P = 0.021), and MS (P = 0.049) were independent prognostic factors for endometrial adenocarcinoma. Furthermore, statistical analyses demonstrated that MS was closely related to stage (P = 0.021), grade (P = 0.022), vascular invasion (P = 0.044), tumor size (P = 0.035), and lymphatic metastasis (P = 0.014) but not with age at start of the first treatment (P = 0.188). Finally, according to the univariate analysis of the OS rate of 129 cases of endometrial adenocarcinoma with MS, stage (P = 0.001), vascular invasion (P = 0.049), tumor size >2 cm (P = 0.028), lymphatic metastasis (P = 0.002), and CA19-9 value >37 U/m (P = 0.002) all showed significantly low P values for OS.

CONCLUSION

Metabolic syndrome is an independent prognostic factor for endometrial adenocarcinoma.

Special role of corn flour as an ideal carbon source for aerobic denitrification with minimized nitrous oxide emission

Much effort has been made for reducing nitrous oxide (N2O) emission in wastewater treatment processes. This paper presents an interesting way to minimize N2O in aerobic denitrification by strain Pseudomonas stutzeri PCN-1 with help of corn flour as cheaper additional carbon source. Experimental results showed that maximal N2O accumulation by strain PCN-1 was only 0.02% of removed nitrogen if corn flour was used as sole carbon source, which was significantly reduced by 52.07-99.81% comparing with others such as succinate, glucose, acetate and citrate. Sustained release of reducing sugar from starch and continuous expression of nosZ coding for N2O reductase contributed to the special role of corn flour as the ideal carbon source for strain PCN-1. Further experiments in sequencing batch reactors (SBRs) demonstrated similarly efficient nitrogen removal with much less N2O emission due to synergy of the novel strain and activated sludge, which was then confirmed by quantitative PCR analysis.

Interaction of Cr(VI) reduction and denitrification by strain Pseudomonas aeruginosa PCN-2 under aerobic conditions

Inhibition of efficient denitrification in presence of toxic heavy metals is one of the current problems encountered in municipal wastewater treatment plants. This paper presents how to remove hexavalent chromium (Cr(VI)) and nitrate simultaneously by the novel strain Pseudomonas aeruginosa PCN-2 under aerobic conditions. The capability of strain PCN-2 for Cr(VI) and nitrate reduction was confirmed by PCR analysis of gene ChrR, napA, nirS, cnorB, nosZ, while Cr(VI) reduction was proved via an initial single-electron transfer through Cr(V) detection using electron paramagnetic resonance. Experimental results demonstrated that Cr(VI) and nitrate reduction by strain PCN-2 was much faster at pH 8-9 and higher initial cell concentration. However, increasing Cr(VI) concentration would inhibit aerobic denitrification process and result in an significant delay of nitrate reduction or N2O accumulation, which was attributed to competition between three electron acceptors, i.e., Cr(VI), O2 and nitrate in the electron transport chain.

Bioaugmentation treatment of municipal wastewater with heterotrophic-aerobic nitrogen removal bacteria in a pilot-scale SBR

PCN bacteria capable of heterotrophic-aerobic nitrogen removal was successfully applied for bioaugmented treatment of municipal wastewater in a pilot-scale SBR. At an appropriate COD/N ratio of 8, the bioaugmentation system exhibited stable and excellent carbon and nutrients removal, the averaged effluent concentrations of COD, NH4(+)-N, TN and TP were 20.6, 0.69, 14.1 and 0.40 mg/L, respectively, which could meet the first class requirement of the National Municipal Wastewater Discharge Standards of China (COD<50 mg/L, TN<15 mg/L, TP<0.5 mg/L). Clone library and real-time PCR analysis revealed that the introduced bacteria greatly improved the structure of original microbial community and facilitated their aerobic nutrients removal capacities. The proposed emerging technology was shown to be an alternative technology to establish new wastewater treatment systems and upgrade or retrofit conventional systems from secondary-level to tertiary-level.

Minimization of nitrous oxide emission in a pilot-scale oxidation ditch: generation, spatial variation and microbial interpretation

Nitrous oxide (N2O) emission from wastewater treatment plants (WWTPs) has received increasing attention. This paper presented how N2O emission was significantly reduced in a pilot-scale Carrousel oxidation ditch under reasonable nitrification and denitrification. N2O emission from the reactor was found as low as 0.027% of influent nitrogen, which was much less than that from other processes. Further measurements on spatial variation of N2O emission in the alternative aerobic/anoxic zones with help of a series of batch experiments demonstrated that about 90% of the emission was contributed by nitrifier denitrification (ND). Moreover, the taxonomic analysis based on high through-put 16S rRNA gene sequencing revealed that the high abundance of denitrifying bacteria and nitrite-oxidizing bacteria (NOB) was responsible for low nitrite accumulations and consequent low N2O emissions. However, N2O generation would be greatly increased upon the normal operation being shocked by either ammonia overload or aeration failure of the oxidation ditch system.

Transplantation of NSC-derived cholinergic neuron-like cells improves cognitive function in APP/PS1 transgenic mice

The ability to selectively control the differentiation of neural stem cells (NSCs) into cholinergic neurons in vivo would be an important step toward cell replacement therapy. First, green fluorescent protein (GFP)-NSCs were induced to differentiate into cholinergic neuron-like cells (CNLs) with retinoic acid (RA) pre-induction followed by nerve growth factor (NGF) induction. Then, these CNLs were transplanted into bilateral hippocampus of APP/PS1 transgenic mice. Behavioral parameters showed by Morris water maze (MWM) tests and the percentages of GFP-labeled cholinergic neurons of CNL transplanted mice were compared with those of controls. Brain levels of choline acetyltransferase (ChAT) mRNA and proteins were analyzed by quantitative real-time PCR and Western blotting, ChAT activity and acetylcholine (ACh) concentration were also evaluated by ChAT activity and ACh concentration assay kits. Immunofluorescence analysis showed that 80.3±1.5% NSCs differentiated into CNLs after RA pre-induction followed by NGF induction in vitro. Three months after transplantation, 82.4±6.3% CNLs differentiated into cholinergic neurons in vivo. APP/PS1 mice transplanted with CNLs showed a significant improvement in learning and memory ability compared with control groups at different time points. Furthermore, CNLs transplantation dramatically increased in the expressions of ChAT mRNA and protein, as well ChAT activity and ACh concentration in APP/PS1 mice. Our findings support the prospect of using NSC-derived CNLs in developing therapies for Alzheimer's disease (AD).

Removal of Hg(II) by poly(1-vinylimidazole)-grafted Fe3O4@SiO2 magnetic nanoparticles

Fe3O4@SiO2 magnetic nanoparticles modified by grafting poly(1-vinylimidazole) oligomer (FSPV) was fabricated as a novel adsorbent to remove Hg(II) from water. Fourier transform infra-red spectroscopy confirmed the successful grafting of oligomer, and thermogravimetric analysis showed FSPV had a high grafting yield with organic content of 22.8%. Transmission electron microscopy image displayed that FSPV particles were polymer-coated spheres with size of 10-20 nm. With saturation magnetization of 44.7 emu/g, FSPV particles could be easily separated from water with a simple magnetic process in 5 min. The Hg(II) adsorption capacity of FSPV was found to be 346 mg/g at pH 7 and 25 °C in 10 mM NaCl. Moreover, the removal of Hg(II) by FSPV was not obviously affected by solution pH (from 4 to 10) or humic acid (up to 8 mg/L as TOC). The presence of seven common ions including Na(+), K(+), Ca(2+), Mg(2+), Cl(-), NO3(-), and SO4(2-) (up to 100 mM ionic strength) slightly increased the adsorption of Hg(II) by FSPV. X-ray photoelectron spectroscopy analysis revealed that the N atom of the imidazole ring was responsible for the bonding with Hg(II), whereas the bonding of Hg with N did not result in cleavage of Hg-Cl bond in HgCl2 and HgClOH. The regeneration of Hg(II)-loaded FSPV could be achieved with 0.5 M HCl rapidly in 10 min, and the removal of Hg(II) maintained above 94% in five consecutive adsorption-desorption cycles. Therefore, FSPV could serve as a promising adsorbent for Hg(II) removal from water.

Nitrite interference and elimination in diphenylcarbazide (DPCI) spectrophotometric determination of hexavalent chromium

Cr(VI) is highly noted as a carcinogenic, mutagenic, and teratogenic pollutant. However, accurate determination of Cr(VI) in aqueous samples is difficult using the conventional diphenylcarbazide (DPCI) spectrophotometric method upon being interfered by co-existed nitrite. This paper illustrates how to eliminate the nitrite influence in a simple but efficient method based on a detailed analysis of interference mechanism. High-performance liquid chromatography analysis revealed that under acidic condition, DPCI was oxidized by nitrite to other substrates, which could not react with Cr(VI). The final oxidation product of DPCI was further purified by thin-layer chromatography and identified as diaryl carbodiazone by Fourier Transform Ion Cyclotron Resonance-Mass Spectrometry (FTICR-MS) and nuclear magnetic resonance. Consequently, an improved method was proposed by simply adding sulfamic acid for eliminating the nitrite interference in Cr(VI) determination. The proposed method was successfully confirmed by the accurate recovery of Cr(VI) from spiked water samples and further proven with inductively coupled plasma-atomic emission spectroscopy, which demonstrated a great potential for determining Cr(VI) concentration in aqueous samples containing nitrite.

Laparoscopic ovarian transposition in young women with cervical squamous cell carcinoma treated by primary pelvic irradiation

OBJECTIVE

To report the authors' experience with laparoscopic ovarian transposition and ovarian function preservation in young women with cervical squamous cell carcinoma treated by primary pelvic irradiation.

MATERIALS AND METHODS

Twenty-seven premenopausal patients were treated with radiotherapy for a cervical squamous cell carcinoma. Laparoscopic ovarian transposition to paracolic gutters with uterine conservation with pelvic common iliac lymph node and para-aortic lymph node sampling were performed in ten patients at the same time of laparoscopic ovarian transposition. Preservation of ovarian function was assessed by patients' symptoms and serum follicle-stimulating hormone level.

RESULTS

Bilateral or unilateral laparoscopic ovarian transposition was performed in 27 patients: 22 cases Stage IIB, one case Stage IIIA, and four cases Stage IIIB. No immediate intraoperative or postoperative complications were observed. Two of the ten patients were confirmed by lymph node metastases. One patient was lost to follow-up. Ovarian preservation was achieved in 18 (69.2%) of 26 patients. No patient was detected with ovarian metastasis at follow-up.

CONCLUSIONS

Laparoscopic ovarian transposition is a safe and effective procedure for preserving ovarian function. This procedure may be considered in premenopausal women who need to undergo pelvic irradiation for cervical squamous cell carcinoma, especially for those less than 40 years of age. Otherwise, para-aortic lymph node or common iliac lymph nods sampling at the same time of laparoscopic ovarian transposition may preferably guide radiation therapy.

Comparative study on gastrointestinal microbiota of eight fish species with different feeding habits

AIMS

To reveal the effects of fish genotype, feeding habits and serum physiological index on the composition of gastrointestinal microbiota, eight fish species with four different feeding habits were investigated.

METHODS AND RESULTS

The V1 to V3 regions of 16S rRNA gene were analysed by high-throughput sequencing (454 platform) to compare the gut microbiota of different fish species. A total of 551 995 high-quality sequences with an average length of 463 bp were obtained from the 48 samples. No significant difference was observed among the detected sequences obtained from fishes with different feeding habits (One-way anova, F = 1·003, P = 0·400), but the number of OTUs among different feeding habits was significantly different (One-way anova, F = 7·564, P < 0·001). Additionally, significant correlations were detected between the fish genotype and microbial composition (partial Mantel test, all P values = 0·001) in the stomach, foregut and hindgut. Moreover, different core intestinal microbiota was also noticed in the eight fish species with different feeding habits.

CONCLUSIONS

Feeding habits and genotype clearly affected the gastrointestinal microbiota of fish. Moreover, the evolutionary process shaped the serum physiological indexes of fish.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study provided much important information for developing commercial fish feeds.

Definition and stabilisation of the quiescent centre in rice roots

The definition of a quiescent centre (QC) in Arabidopsis has been adequately demonstrated. However, the QC structure of rice has not yet been described in detail. In this research, using histological and marker gene expression analysis, we concluded that the rice QC is very small, and is similar to that of Arabidopsis. Next we investigated the stability of the rice QC during nutrient deficiencies or external hormone treatments, and found that nutrient deficiencies, auxin treatment and cytokinin treatment did not change the cell patterns of the QC. However, ethylene induced irregular transverse cell divisions in the QC and changed formative cell divisions of the ground tissue stem cells (GTSCs) in rice.

Orally Administered Fructose Increases the Numbers of Peripheral Lymphocytes Reduced by Exposure of Mice to Gamma or SPE-like Proton Radiation

Exposure of the whole body or a major portion of the body to ionizing radiation can result in Acute Radiation Sickness (ARS), which can cause symptoms that range from mild to severe, and include death. One of the syndromes that can occur during ARS is the hematopoietic syndrome, which is characterized by a reduction in bone marrow cells as well as the number of circulating blood cells. Doses capable of causing this syndrome can result from conventional radiation therapy and accidental exposure to ionizing radiation. It is of concern that this syndrome could also occur during space exploration class missions in which astronauts could be exposed to significant doses of solar particle event (SPE) radiation. Of particular concern is the reduction of lymphocytes and granulocytes, which are major components of the immune system. A significant reduction in their numbers can compromise the immune system, causing a higher risk for the development of infections which could jeopardize the success of the mission. Although there are no specific countermeasures utilized for the ARS resulting from exposure to space radiation(s), granulocyte colony-stimulating factor (G-CSF) has been proposed as a countermeasure for the low number of neutrophils caused by SPE radiation, but so far no countermeasure exists for a reduced number of circulating lymphocytes. The present study demonstrates that orally administered fructose significantly increases the number of peripheral lymphocytes reduced by exposure of mice to 2 Gy of gamma- or SPE-like proton radiation, making it a potential countermeasure for this biological end-point.

High-efficient nitrogen removal by coupling enriched autotrophic-nitrification and aerobic-denitrification consortiums at cold temperature

This study paid particular attention to total nitrogen removal at low temperature (10°C) by excellent coupling of enriched autotrophic nitrifying and heterotrophic denitrifying consortiums at sole aerobic condition. The maximum specific nitrifying rate of the nitrifying consortium reached 8.85mgN/(gSSh). Further test in four identical lab-scale sequencing batch reactors demonstrated its excellent performance for bioaugmentation in potential applications. On the other hand, the aerobic denitrifying consortium could achieve a specific denitrifying rate of 32.93mgN/(gSSh) under dissolved oxygen of 1.0-1.5mg/L at 10°C. Coupling both kinds of consortiums was proved very successful for a perfect total nitrogen (TN) removal at COD/N of 4 and dissolved oxygen of 1.5-4.5mg/L, which was hardly reached by any single consortium reported previously. The encouraging results from coupling aerobic consortiums implied a huge potential in practical treatment of low-strength domestic wastewater (200-300mg/L COD) during wintertime.

Reducing NO and N₂O emission during aerobic denitrification by newly isolated Pseudomonas stutzeri PCN-1

As two obligatory intermediates of denitrification, both NO and N2O had harmful environmental and biological impacts. An aerobic denitrifying bacterial strain PCN-1 was newly isolated and identified as Pseudomonas stutzeri, which was capable of high efficient nitrogen removal under aerobic condition with maximal NO and N2O accumulation as low as 0.003% and 0.33% of removed NO3(-)-N, respectively. Further experiment taking nitrite as denitrifying substrate indicated similar low NO and N2O emission of 0.006% and 0.29% of reduced NO2(-)-N, respectively. Reverse transcription-polymerase chain reaction (RT-PCR) analysis revealed that the coordinate expression of denitrification gene nirS (for cytochrome cd1 nitrite reductase), cnorB (for NO reductase) and nosZ (for N2O reductase) was the fundamental reason of low NO and N2O accumulation. Activated sludge system bioaugmented by strain PCN-1 demonstrated a significant reduction of NO and N2O emission from wastewater during aerobic denitrification, implied great potential of PCN-1 in practical applications.

Synergy of photocatalysis and adsorption for simultaneous removal of Cr(VI) and Cr(III) with TiO₂ and titanate nanotubes

An one-step efficient simultaneous removal of Cr(VI) and Cr(III) was achieved with mixture of TiO₂ and titanate nanotubes (TNTs). Unlike the conventional two-step Cr removal with a first photocatalytic reduction of Cr(VI) and a subsequent adsorption of Cr(III), the proposed single process significantly reduced reaction time (over 50%). The synergy of photocatalysis and adsorption played an important role in enhancing Cr removal process. The synergetic mechanism was interpreted and indirectly confirmed with H₂O₂ variation during photocatalysis. The instant transfer of the reduced Cr from TiO₂ surface to TNTs interlayer greatly promoted the release of photocatalytic sites of TiO₂, which in turn considerably enhanced photocatalytic activity of TNTs by inhibiting electron-hole pairs recombination. The optimum condition for the whole process was at pH 5. Adsorption of Cr(III) was primarily in the interlayer of TNTs at pH ≤ 5. However, higher pH would lead to precipitation of Cr(OH)₃ onto TNTs as observed by X-ray photoelectron spectroscopy (XPS). Addition of Ca(2+) could promoted photocatalysis owing to its ionic bridging function and form of ≡TiOH(+)-Cr(VI)-Ca(2+)-Cr(VI) linkages, while SO₄(2-) only slightly inhibited photo-reduction of Cr(VI), indicating good synergy of photocatalysis and adsorption even at high ionic strength of electrolyte. Besides, the desorbed TNTs could be easily regenerated by remedying the damaged tubular structure and reused for Cr removal with excellent performance. The outstanding synergetic effects with essential explanation of the mechanism make this study not only fundamentally important but also potentially practical applicable.

Three-dimensional three-phase model for simulation of hydrodynamics, oxygen mass transfer, carbon oxidation, nitrification and denitrification in an oxidation ditch

A three-dimensional three-phase fluid model, supplemented by laboratory data, was developed to simulate the hydrodynamics, oxygen mass transfer, carbon oxidation, nitrification and denitrification processes in an oxidation ditch. The model provided detailed phase information on the liquid flow field, gas hold-up distribution and sludge sedimentation. The three-phase model described water-gas, water-sludge and gas-sludge interactions. Activated sludge was taken to be in a pseudo-solid phase, comprising an initially separated solid phase that was transported and later underwent biological reactions with the surrounding liquidmedia. Floc parameters were modified to improve the sludge viscosity, sludge density, oxygen mass transfer rate, and carbon substrate uptake due to adsorption onto the activated sludge. The validation test results were in very satisfactory agreement with laboratory data on the behavior of activated sludge in an oxidation ditch. By coupling species transport and biological process models, reasonable predictions are made of: (1) the biochemical kinetics of dissolved oxygen, chemical oxygen demand (COD) and nitrogen variation, and (2) the physical kinematics of sludge sedimentation.

Relationship between the IL-4 gene promoter -590C/T (rs2243250) polymorphism and susceptibility to autoimmune diseases: a meta-analysis

OBJECTIVE

Studies investigating the association between interleukin (IL)-4 gene promoter -590C/T (rs2243250) polymorphism and autoimmune diseases report conflicting results. To derive a more precise estimation of the relationship, a meta-analysis was performed.

METHODS

A systematic literature search was conducted to identify relevant studies. Pooled odds ratio (OR) with 95% confidence interval (CI) was used to estimate the strength of association.

RESULTS

A total of 6001 cases and 6788 controls from 24 studies were analysed. Significant association of the C allele of IL-4 rs2243250 polymorphism with rheumatoid arthritis (RA) was detected (odds ratio (OR) = 0.696, 95% confidence interval (CI) = 0.601-0.807). Stratification by ethnicity indicated an association between the IL-4 rs2243250 polymorphism and RA in Caucasians. Furthermore, the overall ORs of the associations between the C allele and multiple scleorosis (MS) were 1.340 (95% CI = 1.102-1.630). However, we failed to reveal any association between IL-4 rs2243250 polymorphism and systemic lupus erythematosus (SLE), type 1 diabetes (T1D) or Graves' disease (GD).

CONCLUSIONS

The present study suggests that the IL-4 rs2243250 polymorphism might be associated with genetic susceptibility to autoimmune diseases, including RA and MS.

MMP-7 is upregulated by COX-2 and promotes proliferation and invasion of lung adenocarcinoma cells

Matrix metalloproteinases (MMPs) have been implicated in a variety of pathophysiological conditions, of which MMP-7 is expressed by tumor cells of epithelial and mesenchymal origin. However, the function of MMP-7 in human lung adenocarcinoma (LAC) is unclear. In the present study the expression of MMP-7 in LAC was examined by immunohistochemical assay using a tissue microarray procedure. A loss-of-function experiment was performed to explore the effects and molecular mechanisms of lentiviral vector-mediated MMP-7 siRNA (siMMP-7) on cell proliferation and invasive potential in LAC A549 cells, measured by MTT and Transwell assays, respectively. It was found that, the expression of MMP-7 protein in LAC was significantly increased compared with that in adjacent non-cancerous tissues (ANCT) (76.0% vs 44.0%, P<0.001), and positively correlated with lymph node metastases of the tumor (P=0.014). Furthermore, targeted inhibition of cyclooxygenase-2 (COX-2) by siRNA downregulated the expression of MMP-7 and inhibited invasion of LAC cells, and knockdown of MMP-7 suppressed tumor proliferation and invasion in LAC cells. Taken together, our findings indicate that increased expression of MMP-7 is associated with lymph node metastasis and upregulated by COX-2, and promotes the tumorigenesis of LAC, suggesting that MMP-7 may be a potential therapeutic target for the treatment of cancer.

Dynamical tunneling of a Bose-Einstein condensate in periodically driven systems

We report measurements of dynamical tunneling rates of a Bose-Einstein condensate across a barrier in classical phase space. The atoms are initially prepared in quantum states that extend over a classically regular island region. We focus on the specific system of quantum accelerator modes of the kicked rotor in the presence of gravity. Our experimental data is supported by numerical simulations taking into account imperfections mainly from spontaneous emission. Furthermore, we predict experimentally accessible parameter ranges over which direct tunneling could be readily observed if spontaneous emission was further suppressed. Altogether, we provide a proof-of-principle for the experimental accessibility of dynamical tunneling rates in periodically driven systems.

Effects of Ca2+ on activity restoration of the damaged anammox consortium

Intracellular free Ca(2+) are canonically well known as significant "second messenger" in cells and regarded as critical regulators of bacterial metabolism. We investigated the influence of Ca(2+) dosage on the restoration of anammox consortium, in which nearly 80% cells were dead or badly damaged. Chemical analysis and flow cytometry (FCM) demonstrated that Ca(2+) dosage was of primary importance and the restoration process was apparently faster with increasing Ca(2+) as its concentration was ranged 0.02-0.5mM in feeding. Using FCM and Fura red fluorescence labeling for analysis of intracellular free Ca(2+), we found a strong correlation between external Ca(2+) concentration in feeding and the levels of steady-state intracellular free Ca(2+), the abundance of which was considered as the intrinsic causes for favoring anammox consortium restoration. This study provides new insight into the ions effects on rapid restoration of damaged anammox consortium, targeting efficient nitrogen removal from wastewater with anammox process.

Adsorption of Pb²⁺, Cd²⁺, Cu²⁺ and Cr³⁺ onto titanate nanotubes: competition and effect of inorganic ions

Adsorption of Pb(2+), Cd(2+), Cu(2+) and Cr(3+) from aqueous solutions onto titanate nanotubes (TNTs) in multiple systems was systematically studied. Particular attention was paid to competitive adsorption and the effect of inorganic ions. TNTs showed large adsorption capacity for the four heavy metals, with the mechanism of ion-exchange between metal ions and H(+)/Na(+) located in the interlayers of TNTs. Binary or quaternary competitive adsorption indicated that the adsorption capacity of the four heavy metals onto TNTs followed the sequence of Pb(2+) (2.64 mmol g(-1)) ≫ Cd(2+) (2.13 mmol g(-1)) > Cu(2+) (1.92 mmol g(-1)) ≫ Cr(3+) (1.37 mmol g(-1)), which followed the reverse order of their hydration energies. Moreover, inorganic ions including Na(+), K(+), Mg(2+) and Ca(2+) inhibited the adsorption of heavy metals on TNTs, because they competed for adsorption sites, decreased the activity of heavy metal ions, and promoted the aggregation of TNTs. However, Al(3+) and Fe(3+) generally enhanced adsorption because the resulting hydroxyl-Al/Fe intercalated or coated TNTs could also capture metal ions. Furthermore, minor effect of inorganic ions on adsorption of Pb(2+) resulted from its strong affinity to TNTs. Difficult desorption and small inhibiting effect by Na(+), K(+), Mg(2+) and Ca(2+) on adsorption of Cr(3+) was due to the formed stable complex of HOCr(OTi)₂ ≡ with TNTs. Present study indicated potential applications of TNTs in wastewater treatment for heavy metals.

Heterotrophic nitrification and aerobic denitrification at low temperature by a newly isolated bacterium, Acinetobacter sp. HA2

A psychrotrophic heterotrophic nitrifying-aerobic denitrifying bacterium was newly isolated and identified as Acinetobacter sp. with phenotypic and phylogenetic analysis. The strain possessed excellent tolerance to low temperature with 20°C as its optimum and 4°C as viable. Moreover, ammonium, nitrite and nitrate could be removed efficiently under low-temperature, solely aerobic conditions with little accumulation of intermediates. The average removal rate at 10°C reached as high as 3.03, 2.51 and 1.88 mg NL(-1)h(-1) for ammonium, nitrite and nitrate respectively. N2 was produced through heterotrophic nitrification and aerobic denitrification via nitrite but N2O was never detected in the whole process. Nitrogen balance analysis indicated that N2 and intracellular nitrogen were two major fates of the initial ammonium, accounting for 32.4 and 49.2%, respectively. Further aerated batch test demonstrated efficient removal of COD and TN from synthetic wastewater, which implied promising practical application of the present strain.

Adsorption and desorption of Cd(II) onto titanate nanotubes and efficient regeneration of tubular structures

Efficient regeneration of desorbed titanate nanotubes (TNTs) was investigated with cycled Cd(II) adsorption and desorption processes. After desorption of Cd (II) from TNTs using 0.1M HNO3, regeneration could be simply achieved with only 0.2M NaOH at ambient temperature, i.e. 2% of the NaOH needed for virgin TNTs preparation at 130°C. The regenerated TNTs displayed similar adsorption capacity of Cd(II) even after six recycles, while significant reduction could be detected for desorbed TNTs without regeneration. The virgin TNTs, absorbed TNTs, desorbed TNTs and regenerated TNTs were systematically characterized. As results, the ion-exchange mechanism with Na(+) in TNTs was convinced with obvious change of -TiO(ONa)2 by FTIR spectroscopy. The easy recovery of the damaged tubular structures proved by TEM and XRD was ascribed to asymmetric distribution of H(+) and Na(+) on the surface side and interlayer region of TNTs. More importantly, the cost-effective regeneration was found possibly related to complex form of TNTs-OCd(+)OH(-) onto the adsorbed TNTs, which was identified with help of X-ray photoelectron spectroscopy, and further indicated due to high relevance to an unexpected mole ratio of 1:1 between exchanged Na(+) and absorbed Cd(II).

Serum microRNAs as potential biomarkers of mandibular prognathism

OBJECTIVES

The aim of the study was to determine whether the expression levels of specific circulating serum microRNAs (miRNAs) are associated with mandibular prognathism (MP).

METHODS

Sixty subjects in the early permanent dentition stage and 23 in the mixed dentition stage with MP were identified. Sixty-eight normal control subjects in the early permanent dentition stage and 24 in the mixed dentition stage were recruited for comparison. According to the microarray-based expression profiling, four serum miRNAs (let-7i-3p, miR-595, miR-16-2-3p, and miR-367-5p) were validated.

RESULTS

In the MP groups, let-7i-3p was significantly over-expressed in subjects in the early permanent (P < 0.0005) and mixed (P < 0.001) dentitions, and miR-595 was significantly under-expressed (P < 0.004) in subjects in the early permanent (P < 0.004) and mixed (P < 0.0005) dentitions, compared with normal control groups. Multiple logistic regression analysis and receiver operating characteristic curve analysis revealed that let-7i-3p and miR-595 were able to significantly discriminate MP subjects from normal controls.

CONCLUSION

Let-7i-3p and miR-595 could be potential, non-invasive biomarkers for the accurate early detection and diagnosis of MP, which may result in improved clinical management.