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Background Discrepancies can occur with the use of clinical human immunodeficiency virus (HIV) diagnostic reagents for the HIV window period (WP; time from RNA to antibody detection by diagnostic or blood screening assays). Antiretroviral therapy (ART) during acute HIV infection can impact HIV-specific antibodies, antigens, and DNA/RNA detection. In this study, an HIV WP blood donor who initiated ART was monitored, evaluating the immunological and nucleic acid testing (NAT) results for early ART and discussing the potential effects on blood safety. Study design and methods This was a follow-up study of a HIV WP donor detected 36 hours after high-risk sexual behavior, who was subsequently treated with ART. Immunological and NAT methods were comparatively analyzed. Results The 4th generation HIV serologic assays were positive at Day 11, and the 3rd generation domestic anti-HIV assay was positive at Day 33. Individual donation (ID) NAT and minipool (MP) NAT of six samples were reactive, but 12-sample MP-NAT was nonreactive. ART resulted in a slow decline of HIV RNA, but HIV DNA was still detected on Day 757. Conclusion After ART, ID-NAT was more sensitive than MP-NAT or serologic detection; however, HIV DNA detection was more sensitive, with DNA but not RNA persistently detectable.

A vegetated drainage ditch (VDD) system is an effective management practice for removing excess phosphorus (P) from agricultural runoff. However, the maximization of P removing efficiency by VDD remains a challenge. In this study, new VDDs with akadama clay barriers (particle size of clay: 1–6 mm; height of barrier: 5–15 cm and length of barrier: 10–90 cm) were designed in lab scale, and the mechanism of phosphate removal by akadama clay was investigated. It was found that a new VDD with akadama clay barriers (particle size:1 mm; height:10 cm and length: 90 cm) exhibited the highest removal efficiency of total P (TP) (97.1%), particulate P(PP) (96.9%), and dissolved P (DP) (97.4%), respectively. The retained P was mainly adsorbed in akadama clay barrier sections, and a low concentration of P was observed in soil sections in the new VDD. The maximum adsorption capacity of phosphate to akadama clay was 5.06 mg/g at 298 K, and XPS analysis indicated that phosphate was adsorbed by the inner-sphere complexation formation with the metal elements (Al, Fe). This study indicates that the new VDD with akadama clay barriers is a promising technique to efficiently remove P from agricultural runoff and significantly minimize the risk of P release into streams through runoff.

International audience; We report the synthesis of nanocomposites made of silica nanoparticles whose six surface dimples are decorated with magnetic maghemite nanoparticles and their use for detection and recovery of arsenic in aqueous media. Precursor silica nanoparticles have aminated polystyrene chains at the bottom of their dimples and the maghemite nanoparticles are surface functionalized with carboxylic acid groups in two steps: amination with 3-aminopropyltrimethoxysilane, then derivatization with succinic anhydride in the presence of triethylamine. In the end, the colloidal assembly consists of the regioselective grafting of the carboxylic acid-modified iron oxide nanoparticles onto the 6-dimple silica nanoparticles. Several characterization techniques such as transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), dynamic light scattering (DLS) are employed to assess the grafting process and study the influence of the maghemite functional groups on the quality of the composites formed. The resulting magnetic nanocomposites are used for the environmentally benign detection and removal of arsenic from aqueous medium, being readily extracted through means of magnetic separation.

A superhydrophilic/underwater superoleophobic MgO&SSM coating on SSM (stainless steel mesh) with micro-nano coral-like structure was fabricated by high-temperature treatment of SSM soaked with magnesium nitrate solution. This unique coral-like structure gives it a super high specific surface area and a large number of hydroxyl groups are exposed to the surface. The oil–water separation efficiency achieved 99.0% and the flux attained to 6195 L·m−2 h−1. And the oil–water separation efficiency was always as high as 98.0% after 10 times of repeated use. In addition, it could still maintain underwater superoleophobicity after immersing them in different pH solutions (pH, 5–12) or saturated NaCl solutions for a certain period of time. More importantly, it still maintained underwater superoleophobicity and shown excellent weather resistance after being treated at different temperatures for 2 h or after being exposed to ultraviolet rays at elevated temperatures for 6 h.

Currently, due to high surface to volume ratio; large availability, rapid kinetics of adsorption and desorption and low cost, the exploitation of microbial biosorption of heavy metals is regarded as a reliable alternative compared to the conventional bioremediation approaches. In parallel with the increasing attractiveness of biosorption research, its pace of advance is also boosted. The barrier that prevent biosorption as an effective method from being applied into wastewater purification is listed, (1) There is not enough data on multi-component biosorption, (2) It remains to be seen that physical-chemical characteristics of different biomasses. (3) Studies on surface modification of strains for enhancement of heavy metals removal efficiency is lack. And extensive literatures involving the mechanism and model of biosorption for particular metal and microbial strains are not available. The present literatures lack systematization, the theory on interaction between lactic acid bacteria and Pb is far from complete. Therefore, the review tries to give a comprehensive explanation about the mechanism of Pb removal from Lactic acid bacteria and provide a brief overview of distinction between biosorption and bioaccumulation, biosorption technology, highlight the underlying features of biosorption and the various affecting factors such as pH, dose required, initial concentration, temperature, and treatment performance as a reference. Biosorption mechanisms can be briefly generalized into several pathways, which are ion exchange, complexation, precipitation, reduction and chelation. Many views holds that complexation is the major absorption mechanisms of Pb. Biosorption mechanisms can be roughly classified as biosorption and bioaccumulation, which have great differences between each other. Biosorption is metabolism-independent but fast, while bioaccumulation is metabolism-dependent but slow. The slight advantages of the bioaccumulation are the metabolite (lactic acid), lactobacillus surface-layers, enzymes and so on. Many factors can greatly affect adsorption process, different factors have different influence and the effects of pretreatment, pH and temperature are relatively greater. Desorption is not a fully reversible process of biosorption, but could not only achieve the goal of the recycle of microorganism, but also contribute to release of trace metal elements. Also the technologies for observation of biosorbents characterics and effect on the metal binding process are reviewed.

TiO2 nanotubes have been demonstrated with promising future in photoelectrocatalytic (PEC)_ applications and deposition of Pt nanoparticles on TiO2 has been widely used to enhance their PEC activities. However, those Pt nanoparticles are normally randomly deposited on the surface of TiO2 nanotubes. Selective deposition of Pt nanoparticles is important to achieve better charge separation. In this study, we reported an electrochemical activation step to prepare TiO2 nanotubes deposited with Pt nanoparticles on their open ends. The “activation step” played a key role in achieving a clean surface of the TiO2 nanotubes, thus ensuring the uniform growth of Pt nanoparticles and efficient photogenerated electrons transportation. The Pt-A-TiO2 films have photocatalytic activities in hydrogen generation and methyl orange degradation with a high hydrogen generation rate of 0.74 mL/h/cm2, three times that of the pure TiO2 nanotubes (0.24 mL/h/cm2). Thus, this study demonstrated an effective method for improving the performance of Pt/TiO2 photocatalyst.

Accumulation of organic contaminants on fullerene nanoparticles ( n C 60 ) may significantly affect the risks of C 60 in the environment. The objective of this study was to further understand how the interplay of n C 60 formation routes and humic acid modification affects contaminant adsorption of n C 60 . Specifically, adsorption of 1,2,4,5-tetrachlorobenzene (a model nonionic, hydrophobic organic contaminant) on n C 60 was greatly affected by n C 60 formation route – the formation route significantly affected the aggregation properties of n C 60 , thus affecting the available surface area and the extent of adsorption via the pore-filling mechanism. Depending on whether n C 60 was formed via the “top-down” route ( i.e. , sonicating C 60 powder in aqueous solution) or “bottom-up” route ( i.e. , phase transfer from an organic solvent) and the type of solvent involved (toluene versus tetrahydrofuran), modification of n C 60 with Suwannee River humic acid (SRHA) could either enhance or inhibit the adsorption affinity of n C 60 . The net effect depended on the specific way in which SRHA interacted with C 60 monomers and/or C 60 aggregates of different sizes and morphology, which determined the relative importance of enhanced adsorption from SRHA modification via preventing C 60 aggregation and inhibited adsorption through blocking available adsorption sites. The findings further demonstrate the complex mechanisms controlling interactions between n C 60 and organic contaminants, and may have significant implications for the life-cycle analysis and risk assessment of C 60 .

Graphene was prepared by a simple chemical reduction of graphite oxide in the dimethylacetamide (DMAc)/H2O mixture solvent. The results from Fourier transform infrared spectroscopy, Raman spectroscopy and X-ray photoelectron spectroscopy indicated that the reduction degree of graphene products increased with the increase in the volume ratio of DMAc and water (VDMAc/VH2O), and kept constant when the VDMAc/VH2O ratio was equal or greater than 1. A reduction mechanism from graphite oxide to graphene was proposed. The epoxy groups and hydroxyl on the graphite oxide (GO) surface could be eliminated in the reduction process, whereas the carbonyl was converted to a hydroquinone structure.

A hybrid structure of (NOx)i/S6+-TiO2 (x=0,1) film with high visible-light activity was prepared via facile one-step anodizing in (NH4)2S2O8 electrolyte. The film was characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and ultraviolet-visible-infrared absorption spectroscopy, respectively. Transient photocurrent response and linear sweep voltammetry were also detected. The results showed that the (NOx)i/S6+-TiO2 film was composed of “flower-like” and porous structure. And N and S were successfully doped in the film. Meanwhile, the film also displayed broad and strong optical absorption at around 544 nm and 1500 nm. The photocurrent density reached 0.71 mA/cm2. The decoloration rate was close to 100% and TOC removal reached 59.44% in 20 min under sunlight in photoelectrocatalytic (PEC) degradation methyl orange. The film also exhibited good stability after reuse ten times. A possible mechanism of PEC was suggested in methyl orange degradation by using (NOx)i/S6+-TiO2 film.

Background Pinellia ternata is a Chinese traditional medicinal herb, used to cure diseases including insomnia, eclampsia and cervical carcinoma, for hundreds of years. Non-self-recognition in multicellular organisms can initiate the innate immunity to avoid the invasion of pathogens. A design for pathogen independent, heterosis based, fresh resistance can be generated in F1 hybrid was proposed. Results By library functional screening, we found that P. ternata genes, named as ptHR375 and ptHR941, were identified with the potential to trigger a hypersensitive response in Nicotiana benthamiana. Significant induction of ROS and Callose deposition in N. benthamiana leaves along with activation of pathogenesis-related genes viz.; PR-1a, PR-5, PDF1.2, NPR1, PAL, RBOHB and ERF1 and antioxidant enzymes was observed. After transformation into N. benthamiana, expression of pathogenesis related genes was significantly up-regulated to generate high level of resistance against Phytophthora capsici without affecting the normal seed germination and morphological characters of the transformed N. benthamiana. UPLC-QTOF-MS analysis of ptHR375 transformed N. benthamiana revealed the induction of Oxytetracycline, Cuelure, Allantoin, Diethylstilbestrol and 1,2-Benzisothiazol-3(2H)-one as bioactive compounds. Here we also proved that F1 hybrids, produced by crossing of the ptHR375 and ptHR941 transformed and non-transformed N. benthamiana, show significant high levels of PR-gene expressions and pathogen resistance. Conclusions Heterologous plant genes can activate disease resistance in another plant species and furthermore, by generating F1 hybrids, fresh pathogen independent plant immunity can be obtained. It is also concluded that ptHR375 and ptHR941 play their role in SA and JA/ET defense pathways to activate the resistance against invading pathogens. Electronic supplementary material The online version of this article (10.1186/s12870-018-1598-5) contains supplementary material, which is available to authorized users.

A narrow-gap TiO2 nanofiber film was synthesized on Ti foil by chemical polishing and anodization. The morphology, crystal structure, chemical states, and optical properties were characterized by scanning electron microscopy, X-ray diffraction, X-ray photon electron spectroscopy, and ultraviolet-visible-infrared absorption spectroscopy, respectively. Transient photocurrent response, linear sweep voltammetry, and photoconversion efficiency were also measured. The photocatalytic activity was evaluated from both hydrogen generation and methyl orange degradation experiments. Our results suggested that the film was composed of small uniform TiO2 nanofibers, having interstitial nitrogen-doping, oxygen vacancies and a mixture of anatase and rutile crystal phases. The films exhibited strong and broad optical absorption from 200 to 2500 nm. Owing to this strong absorption and rapid transport of photogenerated electrons, the nanofiber films exhibited a high photoconversion efficiency of 0.62%, and a hydrogen generation rate of 0.62 mL h−1 cm−2 under visible light irradiation. Under solar irradiation the films also showed remarkable efficiency and stability for the degradation of methyl orange.

Hepatic insulin resistance, defined as a diminished ability of hepatocytes to respond to the action of insulin, plays an important role in the development of type 2 diabetes and metabolic syndrome. Aberrant expression of mmu-miR-152-3p (miR-152) is related to the pathogenesis of tumors such as hepatitis B virus related hepatocellular carcinoma. However, the role of miR-152 in hepatic insulin resistance remains unknown. In the present study, we identified the potential role of miR-152 in regulating hepatic glycogenesis. The expression of miR-152 and the level of glycogen were significantly downregulated in the liver of db/db mice and mice fed a high fat diet. In vivo and in vitro results suggest that inhibition of miR-152 expression induced impaired glycogenesis in hepatocytes. Interestingly, miR-152 expression, glycogen synthesis and protein kinase B/glycogen synthase kinase (AKT/GSK) pathway activation were significantly decreased in the liver of mice injected with 16 μg·mL(-1) interleukin 6 (IL-6) by pumps for 7 days and in NCTC 1469 cells treated with 10 ng·mL(-1) IL-6 for 24 h. Moreover, hepatic overexpression of miR-152 rescued IL-6-induced impaired glycogenesis. Finally, phosphatase and tensin homolog (PTEN) was identified as a direct target of miR-152 to mediate hepatic glycogen synthesis. Our findings provide mechanistic insight into the effects of miR-152 on the regulation of the AKT/GSK pathway and the synthesis of glycogen in hepatocytes. Downregulated miR-152 induced impaired hepatic glycogenesis by targeting PTEN. PTEN participated in miR-152-mediated glycogenesis in hepatocytes via regulation of the AKT/GSK pathway.

A series of biochars were prepared by pyrolyzing oak sawdust with/without LaCl3 involvement at temperature of 300-600 °C, and approximate and ultimate analyses were carried out to check their basic characteristics. Meanwhile, the releases of readily soluble NH4(+), NO3(-) and PO4(3-) from biochars and the adsorption of NH4(+), NO3(-) and PO4(3-) by biochars were investigated. Results indicated that the involvement of LaCl3 in pyrolysis could advance the temperature of maximum mass loss by 10 °C compared with oak sawdust (CK), and potentially promoted biochar yield. Overall, the releases of readily soluble NH4(+), NO3(-) and PO4(3-) from biochars were negatively related to pyrolysis temperature, and the releases were greatly weakened by La-biochars. Additionally, the adsorption to NH4(+) can be promoted by the biochars produced at low temperature. On the contrary, the NO3(-) adsorption can be improved by increasing pyrolysis temperature. The highest PO4(3-) adsorption was achieved by the biochars produced at 500 °C. According to the results of adsorption isotherms, the maximum adsorption capacity of NH4(+), NO3(-) and PO4(3-) can be significantly promoted by 1.9, 11.2, and 4.5 folds using La-biochars. Based on the observations of FT-IR, SEM-EDS, and surface functional groups, the improvement of NH4(+) adsorption was potentially associated with the existing acidic function groups (phenolic-OH and carboxyl C=O). The increased basic functional groups on La-biochars were beneficial to improve NO3(-) and PO4(3-) adsorption. Besides, PO4(3-) adsorption was also potentially related to the formed La2O3.

A novel solar-driven TiO2 nanofilm (VO–N–TiO2 (A/R) nanofilm), which was obtained by self-structure modifications, was designed on a Ti substrate surface. The VO–N–TiO2 (A/R) nanofilm showed a three-dimensional pine branched-like structure and a disordered lattice structure, which consisted of VO, N-doping and an anatase/rutile phase, was built in the VO–N–TiO2 (A/R) nanofilm. The experimental results show that the band gap of the VO–N–TiO2 (A/R) nanofilm can be narrowed to 0.72 eV and 2.4 eV and that it exhibited excellent optical absorption capacity in the 200–2500 nm region. Using the VO–N–TiO2 (A/R) nanofilm to degrade methyl orange, the removal efficiency could reach 96% within 150 min under sunlight, which shows its high photoelectrocatalytic activity and stability.

MicroRNAs (miRNAs) are a class of non‑coding 18‑25-nucleotide endogenous RNA molecules. miRNAs act as specific gene silencers to regulate target gene expression at the posttranscriptional level, by base pairing to the 3'‑untranslated region of the target mRNA. miR‑152 is an miRNA that was originally identified in cancer cells, and was shown to be able to modulate the expression of specific oncogenes and tumor suppressor genes, leading to enhanced carcinoma growth. However, little is known regarding the role of miR‑152 in the regulation of hepatic insulin resistance and glucose metabolism. In the present study, it was identified that the activation of AKT and glycogen synthase kinase 3 (GSK‑3), and the expression levels of glycogen, were reduced in mouse NCTC 1469 hepatocytes and mouse primary hepatocytes, following exposure to 25 mM glucose for 48 h. Furthermore, it was demonstrated that high glucose levels suppressed the expression of miR‑152 in hepatocytes. In order to further assess the effects of miR‑152 on the glucose‑induced reduction of glycogen synthesis and activation of AKT and GSK, miR‑152 mimic and inhibitor were transfected into the NCTC 1469 cells, respectively. The transfection of the miR‑152 inhibitor resulted in reduced expression of glycogen, accompanied by impaired phosphorylation of AKT and GSK in the NCTC 1469 cells treated with or without glucose. Conversely, upregulation of miR‑152 by transfection of an miR‑152 mimic reversed the glucose‑induced decrease in glycogen synthesis and reduced AKT and GSK phosphorylation in hepatocytes. This indicated that miR‑152 could modulate the AKT/GSK pathway and glycogen synthesis. In conclusion, to the best of our knowledge, this study was the first to indicate that high glucose impaired the activation of the AKT/GSK pathway and the synthesis of glycogen in mouse hepatocytes, in part through the downregulation of miR‑152.

Carbon-modified TiO2 composite was synthesised via the template method and multi-step calcinations by using a tinfoil package. The carbon-coated TiO2 (C–TiO2) composite was characterised via X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and N2 sorption and thermogravimetry. TiO2 was wrapped up in a carbon layer with a thickness of less than 1 nm. The specific surface area and pore volume of C–TiO2 were 95.6 m2g−1 and 0.247 cm3g−1, respectively. The C–TiO2 composite exhibited mesopore structures, showed preferable adsorption capacity for methyl orange and had a higher photocatalytic activity than its unmodified counterpart.

A poly(2-amino-4-thiazoleacetic acid- co -3-amino-5-mercapto-1,2,4-triazole) (PATA-AMT) film modified glassy carbon electrode (GCE) has been fabricated by using electrochemical copolymerization of 2-amino-4-thiazoleacetic acid (ATA) and 3-amino-5-mercapto-1,2,4-triazole (AMT) and used for electro-catalytic oxidations of dopamine (DA), uric acid (UA) and nitrite ion (NO 2 − ) in 0.1 mol L −1 phosphate buffer solution (PBS, pH 6.0). The surface morphology of the copolythiazole film has been investigated by using scanning electron microscope (SEM). The SEM images show the formation of a non-periodic nano-network structure with a diameter of the fibril varying over the range of 55–85 nm. The copolythiazole film (PATA-AMT) modified GCE (PATA-AMT/GCE) not only exhibits strong electro-catalytic activities toward oxidations of DA, UA and NO 2 − with negatively shifted oxidation overpotentials and enhanced peak current responses, but also can resolve the sluggish and overlapped voltammetric waves of DA, UA and NO 2 − into three sensitive and well-defined oxidation peaks by both cyclic voltammetry (CV) and differential pulse voltammetry (DPV), which can be applied for the selective and simultaneous determinations of DA, UA and NO 2 − in a mixture. Under the optimum conditions, the linear concentration dependences of the DPV current responses are observed for DA, UA and NO 2 − in the concentration ranges of 0.85–390 μmol L −1 , 1.95–1200 μmol L −1 and 2.0–1240 μmol L −1 with the correlation coefficients of 0.9993, 0.9993 and 0.9977, respectively. The detection limits are 0.2 μmol L −1 , 0.25 μmol L −1 and 0.5 μmol L −1 for DA, UA and NO 2 − , respectively (S/N = 3). The different electrochemical behaviors of DA, UA and NO 2 − at various scan rates indicate that the electrode reaction of DA is an adsorption-controlled process, and those of UA and NO 2 − are diffusion-controlled processes at PATA-AMT/GCE. The practical application of the modified electrode has been investigated by the simultaneous determinations of DA, UA and NO 2 − in human urine and serum samples by using standard adding method with satisfactory results.

The accurate determination of solid–liquid interfacial energy and its anisotropy is important for solidification research. In previous measurements using the grain boundary groove method, we found that ignoring anisotropy caused significant uncertainty in measurements of the mean interfacial energy. We thus present an improved grain boundary groove method to eliminate this uncertainty and to measure both the mean interfacial energy and its anisotropy accurately. The validity of this method was testified by the measurement results of pivalic acid and succinonitrile.

Various pH-sensitive sequential interpenetrating polymer network (IPN) hydrogels were prepared by introducing poly (vinyl alcohol) (PVA) hydrogel into Poly (aspartic acid) (PASP) hydrogel by freeze-thawing treatment to obtain a novel drug delivery system to the intestine. The structure and the morphologies of the prepared hydrogels were studied by Fourier Transform Infrared Spectroscopy (FTIR) and scanning electron microscopy (SEM). The thermal behavior and crystallinity of the hydrogels were characterized by differential scanning calorimetry (DSC) and X-ray diffraction (XRD). Their pH-sensitive properties moreover were studied and the results revealed that both PASP hydrogel and IPN hydrogels exhibited excellent pH-sensitivity. Furthermore, the controlled drug release properties of the hydrogels were also evaluated and results indicated that by increasing the PVA fraction in the IPN hydrogel, the release of Naproxen sodium was improved. These results show that the IPN hydrogels could be a suitable carrier for site-specific drug delivery in the intestine.

Carbon nanotubes (CNTs) can exist in the form of colloidal suspension in aquatic environments, particularly in the presence of natural organic matter or surfactants, and may significantly affect the fate and transport of organic contaminants. In the present study, the authors examined the adsorption of phenanthrene, 2-naphthol, and 1-naphthylamine to three colloidal CNTs, including a stable suspension of oxidized multiwalled carbon nanotubes (O-MWNT), a humic acid (HA)-modified colloidal O-MWNT, and a sodium dodecyl sulfate (SDS)-modified colloidal O-MWNT. All three colloidal O-MWNTs exhibit strong adsorption affinities to the three test compounds (with KOC values orders of magnitude greater than those of natural organic matter), likely resulting from strong nonhydrophobic interactions such as π–π electron donor–acceptor interactions and Lewis acid–base interactions. When thoroughly mixed, HA (at ∼310 mg HA/g CNT) and SDS (at ∼750 mg SDS/g CNT) significantly affected the aggregation properties of O-MWNT, causing individually dispersed tubes to form a loosely entangled network. The effects of HA or SDS modification on adsorption are twofold. Adsorption of HA/SDS significantly reduces surface areas of O-MWNT; however, the entangled network allows adsorbate molecules to interact simultaneously with multiple tubes. An important implication is that humic substances and surfactant-like materials not only facilitate the formation of colloidal carbon nanoparticles but also affect how these colloidal carbon nanoparticles adsorb organic contaminants. Environ. Toxicol. Chem. 2013;32:493–500. © 2012 SETAC

Poly(2-amino-5-(4-pyridinyl)-1,3,4-thiadiazole) (PAPT) modified glassy carbon electrode (GCE) was fabricated and used for the simultaneous determinations of dopamine (DA), uric acid (UA) and nitrite (NO2 −) in 0.1 mol L−1 phosphate buffer solution (PBS, pH 5.0) by using cyclic voltammetry and differential pulse voltammetry (DPV) techniques. The results showed that the PAPT modified GCE (PAPT/GCE) not only exhibited electrocatalytic activities towards the oxidation of DA, UA and NO2 − but also could resolve the overlapped voltammetric signals of DA, UA and NO2 − at bare GCE into three strong and well-defined oxidation peaks with enhanced current responses. The peak potential separations are 130 mV for DA–UA and 380 mV for UA–NO2 − using DPV, which are large enough for the simultaneous determinations of DA, UA and NO2 −. Under the optimal conditions, the anodic peak currents were correspondent linearly to the concentrations of DA, UA and NO2 − in the ranges of 0.95–380 μmol L−1, 2.0–1,000 μmol L−1 and 2.0–1,200 μmol L−1 for DA, UA and NO2 −, respectively. The correlation coefficients were 0.9989, 0.9970 and 0.9968, and the detection limits were 0.2, 0.35 and 0.6 μmol L−1 for DA, UA and NO2 −, respectively. In 0.1 mol L−1 PBS pH 5.0, the PAPT film exhibited good electrochemical activity, showing a surface-controlled electrode process with the apparent heterogeneous electron transfer rate constant (k s) of 25.9 s−1 and the charge–transfer coefficient (α) of 0.49, and thus displayed the features of an electrocatalyst. Due to its high sensitivity, good selectivity and stability, the modified electrode had been successfully applied to the determination of analytes in serum and urine samples.

The potential environmental implications of buckminsterfullerene (C60) and its derivatives have received much attention. In this study, we investigated facilitated transport of 2,2',5,5'-polychlorinated biphenyl (PCB) and phenanthrene by nC60 (a stable aqueous-phase aggregate of C60) through two sandy soil columns. We found that low-level (from 1.55 to 12.8 mg/L) nC60 could significantly enhance the mobility of PCB and phenanthrene. However, none of the three model dissolved organic matters (DOMs)-a humic acid, a fulvic acid, and a bovine serum albumin-had a noticeable effect on the transport of PCB when these DOMs were present at concentrations equivalent to approximately 10-11 mg/L organic carbon. We propose that the contaminant-mobilizing ability of nC60 is a result of irreversible adsorption of a fraction of nC60-associated PCB/phenanthrene (whereas DOM-associated PCB is readily desorbable). Additionally, slow desorption kinetics of nC60-adsorbed PCB/phenanthrene is another possible mechanism. The findings in this study indicate that nC60 in the subsurface environment can greatly enhance the mobility of nonionic, highly hydrophobic organic contaminants, which typically exhibit very low mobility. Such effects should be taken into account when assessing the potential environmental risks of engineered carbonaceous nanomaterials.

Adsorption of single-ringed N- and S-heterocyclic aromatics on single-walled carbon nanotubes (SWCNTs) was examined to explore the potential of using carbon nanotubes (CNTs) as drug carriers and environmental adsorbents. Adsorbates included pyrimidine, 2-aminopyrimidine, 4,6-diaminopyrimidine, thiophene, benzene and aniline. Adsorbents included pristine SWCNTs, oxidized SWCNTs, and nonporous graphite. Adsorption of N- and S-heterocyclic aromatics was significantly enhanced by non-hydrophobic interactions. Particularly, the –NH2-substituted compounds exhibited much stronger (up to 2 orders of magnitude) adsorption affinities to oxidized SWCNTs than benzene, even though they are much less hydrophobic. The π–π coupling or electron donor–acceptor (EDA) interactions are likely adsorption-enhancement mechanisms for all six compounds. The lone-pair electrons of the N heteroatoms and the –NH2 group can enable n–π EDA interactions with SWCNT surfaces. Lewis acid–base interactions are another significant adsorption-enhancement mechanism for the –NH2-substituted compounds (and possibly for pyrimidine) on SWCNTs. For the N-heterocyclic aromatics, adsorption affinity is highly dependent on the O-functionality of the SWCNT surface and on solution pH, due to the speciation reactions of both adsorbates and SWCNT surface O-functional groups, indicating that selective adsorption of N-heterocyclic aromatics is possible by combining the surface functionality of CNTs and solution chemistry.

A rectification method was developed for the purification of pivalic acid (PVA) on an experimental scale. Ultrapure PVA with a purity of 99.993% was prepared at a rate of 250 mL a week by multistep rectifications, a more convenient and much faster method than the traditional zone refining method. Typical operational conditions were: head pressure around 1 kPa, reboiler temperature 85°C, head vapor temperature 55°C, condenser temperature 36.5°C, and reflux ratio of 6:1. A formula was given to determine the purity of PVA based on the relationship of freezing point and purity. The freezing point of ultrapure PVA, which was obtained by measuring solidification temperature curve using an inner sheath method, is 35.912 ± 0.001°C.

The combined effects of hydroxyl/amino functional groups of aromatics and surface O-containing groups of carbon nanotubes on adsorption were evaluated. When normalized for hydrophobicity, 2,4-dichlorophenol and 2-naphthol exhibited a greater adsorptive affinity to carbon nanotubes and graphite (a model adsorbent without the surface O functionality) than structurally similar 1,3-dichlorobenzene and naphthalene, respectively, and 1-naphthylamine exhibited a much greater adsorptive affinity than all other compounds. Results of the pH-dependency experiments further indicated that the hydroxy/amino functional groups of the adsorbates and the surface properties of the adsorbents played a combinational role in determining the significance of the nonhydrophobic adsorptive interactions. We propose that the strong adsorptive interaction between hydroxyl-substituted aromatics and carbon nanotubes/graphite was mainly due to the electron-donating effect of the hydroxyl group, which caused a strong electron-donor-acceptor (EDA) interaction between the adsorbates and the pi-electron-depleted regions on the graphene surfaces of carbon nanotubes or graphite. In addition to the EDA interaction, Lewis acid-base interaction was likely an extra important mechanism contributing to the strong adsorption of 1-naphthylamine, especially on the O-functionality-abundant carbon nanotubes. The findings of the present study might have significant implications for selective removal of environmental contaminants with carbon nanotubes.

Insulin resistance is common in critically ill patients and seriously affects their prognosis. The anesthetic propofol (2,6-diisopropylphenol) has been shown to cause insulin resistance in rats; however, the specific mechanism underlying this phenomenon remains unknown. Thus, the aim of the present study was to determine the molecular mechanism through which propofol influences insulin resistance in the liver. The current study assessed the effects of propofol on the phosphorylation level of key enzymes involved in the insulin signaling pathway, as well as the glycogen content in primary mouse hepatocytes. Propofol administration was demonstrated to considerably reduce the phosphorylation levels of Akt (Ser473) and glycogen synthase kinase (GSK)-3β (Ser9) in the primary mouse hepatocytes. In addition, propofol was shown to downregulate the phosphoinositide 3-kinase (PI3K)/Akt/GSK-3β signaling pathway and inhibit glycogen synthesis in hepatocytes. Thus, the present results indicated that propofol induced insulin resistance in primary mouse hepatocytes. Notably, pretreatment with propofol in tumor necrosis factor (TNF)-α-induced primary mouse hepatocytes with insulin resistance was demonstrated to alleviate the inhibitory effects of TNF-α on the PI3K/Akt/GSK-3β signaling pathway and glycogen synthesis. These results indicated that propofol exerts a protective effect against insulin resistance in primary mouse hepatocytes induced by TNF-α, indicating that propofol therapy may be clinically feasible to alleviate insulin resistance in critically ill patients.

KF · 2H2O was found to be a highly efficient base for synthesis of cis‐1,2‐cyclopropanes with arsonium salt and olefins. The advantages of the process are mild reaction condition, easy workup, excellent yields, and high stereoselectivity.

Cyclic GMP-AMP (cGAMP) synthase (cGAS) is recently identified as a cytosolic DNA sensor and generates a non-canonical cGAMP that contains G(2′,5′)pA and A(3′,5′)pG phosphodiester linkages. cGAMP activates STING which triggers innate immune responses in mammals. However, the evolutionary functions and origins of cGAS and STING remain largely elusive. Here, we carried out comprehensive evolutionary analyses of the cGAS-STING pathway. Phylogenetic analysis of cGAS and STING families showed that their origins could be traced back to a choanoflagellate Monosiga brevicollis. Modern cGAS and STING may have acquired structural features, including zinc-ribbon domain and critical amino acid residues for DNA binding in cGAS as well as carboxy terminal tail domain for transducing signals in STING, only recently in vertebrates. In invertebrates, cGAS homologs may not act as DNA sensors. Both proteins cooperate extensively, have similar evolutionary characteristics, and thus may have co-evolved during metazoan evolution. cGAS homologs and a prokaryotic dinucleotide cyclase for canonical cGAMP share conserved secondary structures and catalytic residues. Therefore, non-mammalian cGAS may function as a nucleotidyltransferase and could produce cGAMP and other cyclic dinucleotides. Taken together, assembling signaling components of the cGAS-STING pathway onto the eukaryotic evolutionary map illuminates the functions and origins of this innate immune pathway.

Colloidal fullerene nanoparticles (nC60) in aquatic environments may significantly affect the transport and risks of hydrophobic organic contaminants by serving as a contaminant carrier. The objective of this study was to understand how the combined variables of the preparation method and natural organic matter modification of nC60 might affect the mobility and contaminant-mobilizing capability of nC60, by affecting the physicochemical properties of nC60. We found that an nC60 sample prepared by sonicating C60 powder in deionized water (son_nC60) was much less mobile in saturated sandy soil columns than an nC60 sample prepared by solvent-exchanging from toluene to water (tol_nC60), because son_nC60 was considerably larger in size. However, son_nC60 exhibited greater capability to bind 2,2′,5,5′-polychlorinated biphenyl (PCB), likely because its loosely packed structures rendered more pore spaces, which were favorable adsorption sites for PCB. Forming nC60 samples in Suwannee River humic acid (SRHA) solution (instead of deionized water) only moderately affected the mobility of nC60, but had very significant effects on the contaminant-binding capability of nC60, especially when nC60 was prepared using the solvent exchange method. Adding SRHA after the formation of nC60 had varied effects on the mobility and contaminant-binding capability of nC60, but the fundamental mechanism seems to be linked to how and to what extent SRHA had affected the aggregation/packing of C60 monomers. An important environmental implication is that nC60 formed under different environmental conditions might have vastly different effects on contaminant transport and risks.

By influencing the activity of the PI3K/AKT pathway, IL-6 acts as an important regulator of hepatic insulin resistance. miR-200s have been shown to control growth by regulating PI3K, but the role of miR-200s in the development of hepatic insulin resistance remains unclear. The present study showed that elevated serum concentration of IL-6 is associated with decreased levels of miR-200s, impaired activation of the AKT/glycogen synthase kinase (GSK) pathway, and reduced glycogenesis that occurred in the livers of db/db mice. As shown in the murine NCTC 1469 hepatocytes and the primary hepatocytes treated with 10 ng/ml IL-6 for 24 h and in 12-week-old male C57BL/6J mice injected with 16 μg/ml IL-6 by pumps for 7 days, IL-6 administration induced insulin resistance through down-regulation of miR-200s. Moreover, IL-6 treatment inhibited the phosphorylation of AKT and GSK and decreased the glycogenesis. The effects of IL-6 could be diminished by suppression of FOG2 expression. We concluded that IL-6 treatment may impair the activities of the PI3K/AKT/GSK pathway and inhibit the synthesis of glycogen, perhaps via down-regulating miR-200s while augmenting FOG2 expression.

Human immunodeficiency virus type 1 (HIV-1) replicates productively in vitro in CD4(+)-T cells and/or macrophages. In the host, however, HIV-1 replication may be restricted by the quiescence of susceptible cells. Vpr is a 15-kDa late viral gene product, which is assembled in the virion and suspected to enhance HIV-1 replication in the infected host. We demonstrated previously that Vpr interacted specifically with the cellular transcription factor Sp1, and activated transcription from the HIV-1 long-terminal-repeat. Both Vpr-Sp1 interaction and trans-activation by Vpr required a central Leu/Ile-rich domain (LR domain, aa 60-81) in Vpr. This domain of Vpr was also found critical for Vpr interaction with another cellular protein of 180 kDa. We now provide biochemical evidence that the Vpr LR-domain has a leucine-zipper-like structure. The leucine-zipper structure has been found in a variety of cellular transcription factors, which use the leucine-zipper domain to form a specific dimer before they can bind to DNA through an upstream basic domain. The LR domain of HIV-1 Vpr, when fused to the basic domain of the cellular transcription factor CREB, was capable of supporting specific DNA binding by the CREB basic domain. Point mutational analysis of the Leu/Ile residues in the LR domain suggested that multiple Leu/Ile residues may be involved in maintaining the leucine-zipper-like structure. Mutagenesis in the context of the full-length Vpr also helped identify Leu/Ile residues may be involved in maintaining the leucine-zipper-like structure. Mutagenesis in the context of the full-length Vpr also helped identify Leu/Ile residues critical for Vpr interaction with the cellular 180-kDa protein. These results suggested that the leucine-zipper-like domain may be an important functional determinant for HIV-1 Vpr.

Fullerene nanoparticles (nC60) in aqueous environments can significantly enhance the transport of hydrophobic organic contaminants by serving as a contaminant carrier. In the present study, the authors examine the effect of the solvent-exchange process on nC60 aggregate formation and, subsequently, on nC60's contaminant-mobilizing capability. A series of nC60 samples were prepared using a modified toluene–water solvent-exchange method through the inclusion of a secondary organic solvent in the phase transfer of molecular C60 in toluene to nC60 in water. Two groups of solvents—a water-miscible group and a non–water-miscible group—of varied polarity were selected as secondary solvents. The involvement of a secondary solvent in the phase transfer process had only small effects on the particle size and distribution, ζ potential, and mobility of the nC60 products but significantly influenced the capability of nC60 to enhance the transport of 2,2′,5,5′-polychlorinated biphenyl (PCB) in a saturated sandy soil column, regardless of whether the secondary solvent was water-miscible or non–water-miscible. The two groups of secondary solvents appear to affect the aggregation properties of nC60 in water via different mechanisms. In general, nC60 products made with a secondary water-miscible solvent have stronger capabilities to enhance PCB transport. Taken together, the results indicate that according to formation conditions and solvent constituents, nC60 will vary significantly in its interactions with organic contaminants, specifically as related to adsorption or desorption as well as transport in porous media. Environ. Toxicol. Chem. 2013;32:329–336. © 2012 SETAC

Understanding subsurface transport of fullerene nanoparticles (nC(60)) is of critical importance for the benign use and risk management of C(60). We examined the effects of several important environmental factors on nC(60) transport in saturated porous media. Decreasing flow velocity from approximately 10 to 1 m/d had little effect on nC(60) transport in Ottawa sand (mainly pure quartz), but significantly inhibited the transport in Lula soil (a sandy, low-organic-matter soil). The difference was attributable to the smaller grain size, more irregular and rougher shape, and greater heterogeneity of Lula soil. Increasing ionic strength and switching background solution from NaCl to CaCl(2) enhanced the deposition of nC(60) in both sand and soil columns, but the effects were more significant for soil. This was likely because the clay minerals (and possibly soil organic matter) in soil responded to changes of ionic strength and species differently than quartz. Anions in the mobile phase had little effect on nC(60) transport, and fulvic acid in the mobile phase (5.0 mg/L) had a small effect in the presence of 0.5 mM Ca(2+). A two-site transport model that takes into account both the blocking-affected attachment process and straining effects can effectively model the breakthrough of nC(60).

Stable colloidal suspensions of buckminsterfullerene (nC(60)) in aqueous environments can significantly affect the fate and transport of hydrophobic organic contaminants by serving as a contaminant carrier. In this study, we examined enhanced transport of 2,2',5,5'-polychlorinated biphenyl (PCB) in saturated sandy soil columns by a variety of nC(60) samples, including an nC(60) sample prepared by the typical solvent exchange method, as well as eight natural organic matter (NOM) or surfactant-modified nC(60) samples, prepared by phase-transferring C(60) from toluene to an NOM or a surfactant solution. Whereas the NOM- and surfactant-modified nC(60) samples have mobility similar to the unmodified nC(60), their contaminant-mobilizing capabilities are significantly greater: breakthrough of PCB increases by 47.2 to 227% with the surfactant-modified nC(60) samples and by 233 to 370% with the NOM-modified nC(60) samples. The significantly enhanced contaminant-mobilizing capability of the modified nC(60) is likely due to a combined effect of increased adsorption affinities and increased tendency of desorption nonequilibrium, likely caused by the changes of nC(60) aggregation properties induced by the presence of NOM or surfactant. Findings in this study indicate that nC(60) formed in different processes might have vastly different effects on contaminant fate and transport.

Tumors release genomic DNA into the circulation of cancer patients after cellular necrosis and apoptosis. Isolation of the apoptotic fraction of plasma-circulating DNA can enhance detection of low-level mutations that can serve as tumor biomarkers (1). Because the amount of DNA circulating in the plasma of cancer patients is low, on the order of a few nanograms per milliliter of blood, the number of genes that can be examined for tumor-specific alterations is limited, a situation that reduces biomarker sensitivity. We recently applied whole-genome amplification of plasma-circulating DNA to increase the number of targets that can be analyzed from each sample, thus potentially increasing biomarker sensitivity(2). This approach yields highly-expanded DNA amounts for performing genetic screening; however, there is no preferential enrichment of smaller sized DNA fragments. We report a new method for whole-genome amplification of plasma-circulating DNA, based on ligation-mediated PCR of blunted DNA fragments (BLM-PCR)1 , which results in preferential amplification of smaller size, apoptotic DNA fragments. Plasma-circulating DNA was extracted from blood obtained from radiation therapy patients after the patients gave informed consent and the study received institutional review board approval. Within 2–3 h of collection, whole blood was centrifuged at 2000 g for 15–30 min, plasma was separated, and plasma-circulating DNA was purified by use of a QIAamp™ MinElute Virus Spin Kit (Qiagen) and quantified via Taqman real-time-PCR. To test for v-Ki-ras2 Kirsten …

KF · 2H2O was found to be a highly efficient base for synthesis of cis‐1,2‐cyclopropanes with arsonium salt and olefins. The advantages of the process are mild reaction condition, easy workup, excellent yields, and high stereoselectivity.

Crystal orientation influences the morphological stability of solid—liquid interface during directional solidification of alloy, resulting in the variation of solidified microstructure. In this paper, the morphological evolution near grain boundary grooves (GBGs) with different crystal orientations in a dilute succinonitrile alloy under low temperature gradient and interface velocity is observed in situ. Under experimental conditions, the macroscopic solid—liquid interface is planar and keeps stable, while in GBGs there emerge protrusion and undulation. It is found that the morphological stability of GBG is dependent on crystal orientation. Specifically, for succinonitrile with a body-centered cubic crystal structure, GBGs around the 〈100〉 crystal orientation keep stable, while those apart from the 〈100〉 crystal orientation become unstable under the same conditions. So it is concluded that 〈100〉 crystal orientation favors the morphological stability of GBG.

Many genes that are required for cell division have been identified in Escherichia coli. These include the fts genes ftsA, ftsZ, ftsQ, ftsN, ftsL, ftsK, ftsW, and ftsI and the recently identified zipA gene (21, 31). These genes, and probably others that are not yet identified, are responsible for the formation of the septum at midcell. The septum is formed through invagination of the cytoplasmic membrane and the accompanying synthesis of peptidoglycan at the leading edge of the invagination. This septal specific peptidoglycan biosynthesis occurs in two stages (36, 46, 47), an early stage that is penicillin insensitive and a later stage that is sensitive to penicillin and requires PBP3, the product of the ftsI gene (9, 40). Genetic and inhibitor studies suggest that there are two modes of peptidoglycan synthesis involved in cell growth: elongation and septal. The elongation mode of synthesis requires PBP2 and RodA (41), whereas the septal mode requires FtsI (PBP3) and possibly FtsW (23, 40). PBP2 and FtsI are both

The morphological stability of a planar interface with different crystallographic orientations is studied under a small positive temperature gradient using a transparent model alloy of succinonitrile. Novel experimental apparatus is constructed to provide a temperature gradient of about 0.37 K/mm. Under this small temperature gradient, the planar interface instability depends largely on the crystallographic orientation. It is shown experimentally that the effect of interfacial energy anisotropy on planar interface stability cannot be neglected even in a small temperature gradient system. Higher interfacial energy anisotropy leads the planar interface to become more unstable, which is different from the stabilizing effect of the interfacial energy on the planar interface. The experimental results are in agreement with previous theoretical calculations and phase field simulations.

The two-dimensional equilibrated grain boundary grooves (GBG) of succinonitrile (SCN) was directly observed by using a temperature gradient stage with high temperature stability to measure the solid-liquid interfacial free energy and its anisotropic factor. Based on the numerical solution of Gibbs-Thomson equation and parameter optimization method, the liquid-solid interfacial free energy and its anisotropy of SCN were extracted from the digitised GBG shapes respectively. The results show that the average solid-liquid interfacial free energy is ?0 = 9.66?10?3J?m?2, and the average anisotropic factor is 4 = 0.85%.