Electrochemical disinfection for ballast water management: technology development and risk assessment

Ballast water is essential in maintaining the balance and structural integrity of ships during voyage. However, it has created biological invasion threats to the ocean environment. An innovative electrochemical technology was developed in this study. The microorganisms regulated by the International Maritime Organization (D2) were used as the target organisms. It was found that the required energy to meet the D2 was below 0.006 kWh/m3. The size of disinfector (m3) was about 0.5% of treatment flow rate (m3/h). The complete disappearance of chlorine in seawater was achieved after three days. The ballast tank corrosion was not worsened due to the application of technology. The ecotoxicity studies showed no toxic effect on fish, invertebrate, and algae. Finally, the environmental risk assessment showed the treated water did not pose threats to the environment. It can therefore be concluded that the technology provides a cost-effective and environmental friendly solution to ballast water management.

Design and fabrication of an innovative and environmental friendly adsorbent for boron removal

Boron can pose adverse effects on human beings and plants species. It exists in various water environments and is difficult to be removed by conventional technologies. In this study, an efficient and environmental friendly sorbent was fabricated by the functionalization of a natural biopolymer, chitosan, with N-methylglucamine through atom transfer radical polymerization. The SEM and BET studies revealed that the sorbent had a rougher surface and a more porous structure than the chitosan. At the optimum neutral pH, the maximum sorption capacity was as high as 3.25 mmol/g, much higher than the commercial boron selective resins (e.g., Amberlite IRA-743) and many other synthesized sorbents. Almost 90% of boron sorption occurred within 8 h and the equilibrium was established in 12 h, which was well described by an intraparticle surface diffusion model. The presence of sodium chloride and sodium nitrate had no effect on the boron removal. The boron concentration in seawater could be reduced to less than 0.5 mg/L from 4.8 mg/L when a sorbent dosage of 1.2 g/L was used. It was therefore concluded that the sorption technology from this study could be promising for boron removal from aqueous solutions.

Uptake of methylated arsenic by a polymeric adsorbent: process performance and adsorption chemistry

Methylated arsenic in groundwater has caused a series of health problems to human beings. A N-methylglucamine modified chitosan polymeric adsorbent was successfully developed for efficient adsorption of methylated arsenic from water solution. Adsorption behaviors of two common methylated arsenic species, monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA), onto the adsorbent were investigated in this paper. The surface modification increased the adsorption capabilities for the arsenic. The uptake of MMA was higher than that of DMA throughout all pH values. The maximum adsorption capacities were 15.4 mg/g for MMA and 7.1 mg/g for DMA, exhibiting competitive advantages with other reported materials. The affinity of these arsenic species for the adsorbent followed a pattern of MMA > DMA. The adsorption equilibrium was achieved within 20 h. The uptake of MMA and DMA was dependent upon the concentration of background electrolytes, indicating the formation of outer-sphere complexes of both organoarsenic species with the adsorbent during the adsorption. The existence of natural organic matter and competitive anions cause decrease in the uptake of both arsenic species. Furthermore, the simultaneous uptake of organic contaminants such as humic acid was observed. The spectroscopic analysis demonstrated the strong attachment of both organic arsenic species onto the amine functional group of the adsorbent.

Preparation and characterization of chitosan encapsulated Sargassum sp. biosorbent for nickel ions sorption

A new biosorbent -Sargassum sp. encapsulated with epichlorohydrin (ECH) cross-linked chitosan (CS) was investigated for nickel ions removal. The prepared biosorbent with Sargassum sp. to cross-linked chitosan of 3 (weight ratio) had the highest sorption capacity. The biosorption kinetics can be well fitted by the diffusion-controlled model. The organic leaching of CS was 77-88% less than that of algae at different pH. The biosorption capacity of nickel on CS was much higher than that of cross-linked chitosan (CLC) bead and lower than that of raw algae due to encapsulation. In addition, the reusability of CS was further evaluated and confirmed through five adsorption-desorption cycles. Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS) analysis demonstrated that the nickel ions sequestration mechanism included ion exchange and nickel complexation with the carboxyl, amino, alcoholic and ether groups in CS.

Improvement of metal adsorption onto chitosan/Sargassum sp. composite sorbent by an innovative ion-imprint technology

Technology for immobilization of biomass has attracted a great interest due to the high sorption capacity of biomass for sequestration of toxic metals from industrial effluents. However, the currently practiced immobilization methods normally reduce the metal sorption capacities. In this study, an innovative ion-imprint technology was developed to overcome the drawback. Copper ion was first imprinted onto the functional groups of chitosan that formed a pellet-typed sorbent through the granulation with Sargassum sp.; the imprinted copper ion was chemically detached from the sorbent, leading to the formation of a novel copper ion-imprinted chitosan/Sargassum sp. (CICS) composite adsorbent. The copper sorption on CICS was found to be highly pH-dependent and the maximum uptake capacity was achieved at pH 4.7-5.5. The adsorption isotherm study showed the maximum sorption capacity of CICS of 1.08 mmol/g, much higher than the non-imprinted chitosan/Sargassum sp. sorbent (NICS) (0.49 mmol/g). The used sorbent was reusable after being regenerated through desorption. The FTIR and XPS studies revealed that the greater sorption of heavy metal was attributed to the large number of primary amine groups available on the surfaces of the ion-imprinted chitosan and the abundant carboxyl groups on Sargassum sp. Finally, an intraparticle surface diffusion controlled model well described the sorption history of the sorbents.

Measurements of the electric form factor of the neutron up to Q2=3.4 GeV2 using the reaction 3He(e,e'n)pp

The electric form factor of the neutron was determined from studies of the reaction 3He(e,e'n)pp in quasielastic kinematics in Hall A at Jefferson Lab. Longitudinally polarized electrons were scattered off a polarized target in which the nuclear polarization was oriented perpendicular to the momentum transfer. The scattered electrons were detected in a magnetic spectrometer in coincidence with neutrons that were registered in a large-solid-angle detector. More than doubling the Q2 range over which it is known, we find G(E)(n)=0.0236±0.0017(stat)±0.0026(syst), 0.0208±0.0024±0.0019, and 0.0147±0.0020±0.0014 for Q(2)=1.72, 2.48, and 3.41 GeV2, respectively.

Enhanced adsorption of arsenate onto a natural polymer-based sorbent by surface atom transfer radical polymerization

Arsenic contamination in water, especially in groundwater, has been recognized as an important issue of concern because of its high mobility and toxicity. In this study, N-methylglucamine was immobilized onto crosslinked chitosan beads via atom transfer radical polymerization for an efficient adsorption of arsenic. It was demonstrated that the immobilization significantly enhanced the adsorption capacity. The uptake onto the adsorbent was highly pH dependent, and a maximum adsorption capacity as high as 69.28 mg/g was obtained at the optimum pH of 5. Most of arsenate was rapidly adsorbed in the first 5h, and the adsorption equilibrium was established in 16 h, which was well described by an intraparticle diffusion model. The adsorbent exhibited a great uptake of the humic acid, which led to a decrease in the adsorption of arsenate. The effects of competitive anions on the adsorption exhibited the following descending sequence: sulfate ≫ phosphate>fluoride (negligible effect). Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy indicated that the arsenic adsorption resulted from the presence of tertiary amine and hydroxyl functional groups grafted on the crosslinked chitosan.

Probing quark-gluon interactions with transverse polarized scattering

We have extracted QCD matrix elements from our data on doubly polarized inelastic scattering of electrons on nuclei. We find the higher twist matrix element d˜2, which arises strictly from quark-gluon interactions, to be unambiguously nonzero. The data also reveal an isospin dependence of higher twist effects if we assume that the Burkhardt-Cottingham sum rule is valid. The fundamental Bjorken sum rule obtained from the a0 matrix element is satisfied at our low momentum transfer.

Intra- and intergenomic chromosome pairings revealed by dual-color GISH in trigenomic hybrids of Brassica juncea and B. carinata with B. maurorum

From dual-color genomic in situ hybridization (GISH) analysis of three trigenomic hybrids, Brassica maurorum (MM, 2n = 16) x B. juncea (AABB, 2n = 36) (M.AB), B. maurorum x B. carinata (BBCC, 2n = 34) (M.BC), and B. carinata x B. maurorum (BC.M), the three genomes of each hybrid were distinguished and autosyndesis and allosyndesis were evaluated. In M.AB, up to two autosyndetic bivalents occurred among the chromosomes of each genome; a maximum of three allosyndetic bivalents appeared between A-B, A-M, and B-M genomes. The similar pairings in M.BC and BC.M suggested that the cytoplasm of B. maurorum or B. carinata had no obvious effect on chromosome pairing. In M.BC and BC.M, a maximum of one autosyndetic bivalent was found for B and M genomes, but two were found for the C genome; from 0 to 2 allosyndetic bivalents were observed between B-C, B-M, and C-M genomes. The B-M allosyndesis frequency was higher than the A-M or C-M allosyndesis frequency in these hybrids, revealing the closer relationship of B and M genomes. The allosyndesis frequency was higher than the autosyndesis frequency among A, B, and C genomes in these combinations, suggesting that intergenomic homoeology was higher than intragenomic homoeology. The implications for genome evolution and crop breeding are discussed.

The role of intravascular ultrasound to guide drug-eluting stents implantation

Serial IVUS has demonstrated significant differences in intimal hyperplasia (IH) volume between drug-eluting stent (DES) and bare metal stents (BMS) in recent clinical trials. It has also been reported that IVUS is a useful tool in determining optimal DES implantation, especially for diabetes mellitus (DM) patients. Recent data have also suggested a critical role for, IVUS guidance in reduction of risk for DES thrombosis. IVUS has been invaluable in the elucidation of DES effects on the arterial wall, offering insight into the potential mechanisms of DES failure. Therefore, in this current manuscript, we review the potential benefits of intravascular ultrasound (IVUS) during drug eluting stent (DES) implantation.

Organic arsenic adsorption onto a magnetic sorbent

The adsorption of organic arsenate, monomethylarsonate (MMA), onto a calcium alginate encapsulated magnetic sorbent is studied in this paper. A novel alginate encalsulated magnetic sorbent was used in the experiments on adsorption isotherm, kinetics, and pH effect. It was found that the equilibrium sorption can be attained within 25 h. Solution pH plays a key role in the removal of MMA from the solution. A greater adsorption can be achieved at pH 4 and below. The maximum sorption capacity of MMA was 8.57 mg As/g, which is slightly higher than the reported adsorbents. The interaction characteristics between the organic arsenate and magnetic sorbent were elucidated by applying FT-IR and XPS analyses. It is shown that the -COOH and Fe-O groups in the sorbent are involved in the adsorption process. The appearance of As-CH(3) and alkane C-H groups in the FT-IR spectrum reveals the binding of the organic arsenate to the sorbent. The XPS analysis indicates that reduction of organic arsenate to organic arsenite on the sorbent's surface happens through solid state redox reaction via charge transport from Fe(II) and C-O species in the sorbent. The XPS results also show the disappearance of C-OH and formation of As-O. It is deduced from the spectral results that mechanisms of organic arsenate adsorption involve C-OH, As-O, and Fe-O groups with the solid state redox process.

Uptake of arsenate by an alginate-encapsulated magnetic sorbent: process performance and characterization of adsorption chemistry

Arsenate removal by a calcium alginate-encapsulated magnetic sorbent was studied. The morphology, microstructure, and composition properties of the sorbent were explored using X-ray diffraction (XRD) and scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDX). The SEM study demonstrates that there are many protuberances and pores on the sorbent surface; the XRD analysis reveals that the sorbent consists of Fe(3)O(4). The EDX analysis indicates that the adsorption on the surfaces of sorbent is highly location dependent. The interaction characteristics between the arsenic and the functional groups on the sorbent were studied by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). These studies indicate that the lattice oxygen in magnetite and the oxygen in hydroxyl of the calcium alginate play important roles in the sorption of arsenate ions onto the sorbent. More importantly, the XPS analysis demonstrates that the arsenate is reduced to arsenite after its adsorption onto the sorbent. It is proposed that divalent iron and the alcoholic group in alginate provide electrons to arsenate. A conceptual model for the adsorption is proposed to illustrate the mechanisms.

Characterization of copper adsorption onto an alginate encapsulated magnetic sorbent by a combined FT-IR, XPS, and mathematical modeling study

Copper adsorption onto calcium alginate encapsulated magnetic sorbent is studied in this paper. The objective of this study was to qualitatively and quantitatively elucidate the copper binding onto the sorbent. The adsorption increases from around 0 to almost 100% as the initial pH is increased from 2 to 5. A maximum adsorption capacity of 0.99 mmol g(-1) is achieved. The FT-IR and XPS studies show that the C-O in carboxyl group of alginate directly attaches to the copper ion that leads to most of the adsorption. A mathematical model is developed, and it includes ion exchange between the calcium and the copper, coordination reaction between the functional group and the copper, as well as surface complex formation between the iron oxide and the copper. The model is capable of describing and predicting effects of various key operational parameters on the adsorption process, such as initial pH, metal concentration, and dosage of sorbent.

Isolation and characterization of polymorphic microsatellite markers for the masked palm civet (Paguma larvata)

The masked palm civet (Paguma larvata) has been suspected to be the host of a SARS-like CoV virus that causes severe acute respiratory syndrome in humans. In China, the palm civet lives wild and is farmed, but even though the species is a potential carrier of the virus, its geographic distribution and genetic diversity have never been studied. We report the isolation and characterization of six polymorphic microsatellite markers for P. larvata. To characterize each locus, two farmed masked palm civet populations from Shanxi and Guangxi provinces in China were genotyped. The number of alleles per locus ranged from 3 to 15, and the observed heterozygosity for these populations was 47.1 and 68.7%, respectively.

Active pharmaceutical ingredients and mechanisms underlying phasic myometrial contractions stimulated with the saponin extract from Paris polyphylla Sm. var. yunnanensis used for abnormal uterine bleeding

BACKGROUND

Total steroidal saponins of Paris polyphylla Sm. var. yunnanensis (TSSP) have been widely used in China for the treatment of abnormal uterine bleeding (AUB). But until now, the main active constituents and the mechanisms underlying the pharmacological actions on uterine activity have not been described.

METHODS

Total steroidal saponins were extracted with EtOH and purified by chromatography. In vitro isometric contraction studies were performed using myometrial strips from estrogen-primed or pregnant rats. Intracellular calcium was monitored under a confocal microscope using Fluo-3 AM-loaded myometrial cells.

RESULTS

TSSP dose-dependently induced phasic myometrial contractions in vitro. Experiments with calcium channel blockers or kinase inhibitors demonstrated that the TSSP-stimulated myometrial contraction was mediated by an increase in [Ca(2+)](i) via influx of extracellular calcium and release of intracellular calcium. Through bioassay-guided separation, it was found that total spirostanol saponins exhibited contractile activity in myometrium and Pennogenin-3-O-alpha-L-arabinofuranosyl(1-->4)[alpha-L-rhamnopyranosyl(1-->2)]-beta-D-glucopyranoside (PARG) was identified as the active ingredient of TSSP. Furthermore, the contractile response of rat myometrium to PARG was significantly enhanced with advancing pregnancy.

CONCLUSIONS

These data provide evidence that myometrial contractility stimulated by TSSP results from [Ca(2+)](i) increase and supports the possibility that some spirostanol gylcosides may represent a new type of contractile agonist for the uterus.

Review of percutaneous therapy for bifurcation lesions in the era of drug-eluting stents

Although recent advances in percutaneous coronary interventions (PCI) have led to dramatic expansions in procedural complexity, bifurcation lesions (BL) remain a serious challenge for the interventionalist. Turbulent flow dynamics and high shear stress likely predispose coronary bifurcations to development of atherosclerotic plaques. These lesions comprise 15% to 20% of the total number of coronary interventions. When compared with non-BL interventions, BL interventions demonstrate lower procedural success rates, higher procedural costs, longer hospitalizations, and higher clinical and angiographic restenosis rates. The recent introduction of drug-eluting stents (DES) has resulted in lower incidences of target lesion/ vessel revascularization and reduction of main branch restenosis in this anatomic subset, when compared to historical bare metal stent (BMS) controls. Nonetheless, DES have not resolved the bifurcation PCI problem; and several techniques employing either 1 or 2 stents have emerged. Stenting of the main vessel with provisional side branch stenting seems to be the prevailing approach. While no definitive single BL-PCI technique has been identified, the optimal approach is likely lesion-specific. This paper reviews different treatment modalities for this complex lesion subset, with particular emphasis on the use of DES, as well as new potential therapeutic approaches.

Biosorption of hexavalent chromium onto raw and chemically modified Sargassum sp

Hexavalent chromium biosorption by raw algae is always accompanied with significantly high organic leaching. In this study, hydrochloric acid, sodium hydroxide, calcium chloride, formaldehyde, and glutaraldehyde were used for modification of raw Sargassum sp. seaweed (RSW), in order that the modified seaweed (MSW) has a lower organic leaching while the metal biosorption capacity is comparable to the RSW. The result shows that the chemical modification by 0.2% formaldehyde achieves such goals. The biosorption of both RSW and MSW is highly pH dependent. At the optimal pH of 2.0, the maximum biosorption capacities of MSW and RSW are 1.123 and 0.601 mmol g(-1), respectively. The surface treatment improves the reduction capacity of the biosorbents. The instrumental analysis demonstrates that the Cr(VI) biosorption is controlled by redox, ion exchange and coordination reactions, of which alcohol, carboxyl, amino and sulphonic groups play important roles. The complete uptake of hexavalent chromium is achieved in 20 h. The chemical reduction for Cr(VI) to Cr(III) is pH dependent and controls the overall chromium removal kinetics.

Measurements of the proton elastic-form-factor ratio mu pG p E/G p M at low momentum transfer

High-precision measurements of the proton elastic form-factor ratio, mu pG p E/G p M, have been made at four-momentum transfer, Q2, values between 0.2 and 0.5 GeV2. The new data, while consistent with previous results, clearly show a ratio less than unity and significant differences from the central values of several recent phenomenological fits. By combining the new form-factor ratio data with an existing cross-section measurement, one finds that in this Q2 range the deviation from unity is primarily due to G p E being smaller than expected.

Effects of Shugansanjie Tang on matrix metalloproteinases 1, 3 and 9 and telomerase reverse transcriptase expression in human breast cells in vitro

BACKGROUND

The traditional Chinese medication Shugansanjie Tang (SGT), whose active component is Akebia Trifoliate Koidz, possesses potential anti-tumor and immunostimulatory effects especially for breast cancer. The invasive processes of such cancers have been attributed to matrix metalloproteinases (MMPs) which may be the key factor mediating this process. Telomerase reverse transcriptase (TERT) catalyze the lengthening of telomeres, which prolongs cell life and interrupts natural cell death. The aim of this study is to determine the effects of Shugansanjie Tang on MMP levels and TERT activity using breast cancer cell lines.

MATERIALS AND METHODS

We used the breast cancer cell lines MDA-MB-231 and BT-483. Cell inhibition rate was measured by WST-1 reagent, cell apoptosis by Apoptotic DNA Ladder Kit, mRNA expression of MMP-1, MMP-3 and MMP-9 by PCR and TERT by immunohistochemistry stain.

RESULTS

Comparing to the control group, the test group showed lower cell growth rate, decreased mRNA expression of MMP-1, MMP-3 and MMP-9 production and less intense staining of MMPs with diaminobenzidine tetrahydrochloride.

CONCLUSION

This study demonstrated that Shugansanjie Tang inhibits the growth of breast cancer cells by apoptosis and lowers the level of certain matrix metalloproteinases and activity of telomerase reverse transcriptase in breast cancer in vitro.