High-rate MIEX filtration for simultaneous removal of phosphorus and membrane foulants from secondary effluent

This work was designed to evaluate the effectiveness of magnetic ion exchange (MIEX) resin under the best possible conditions, passage through a fixed-bed of resin as opposed to the alternative of directly adding resin into a flowing stream. The possibility of using a very small amount of alum in addition to MIEX treatment was also investigated not only to adsorb residual EfOM in the effluent from a bed of MIEX but also to produce a porous cake layer that would keep away foulants from the surface of membrane or its pore walls. The MIEX treatment alone reduced fouling, but to a much lesser extent than for MIEX combined with an under-dosing coagulation (which uses a considerably low amount of alum). Almost all of colloids and organic acids were removed and the nearly complete removal of phosphorus was achieved by MIEX in a fixed-bed even for an extremely short hydraulic retention time of wastewater in the resin bed. MIEX resin removed phosphorus, but organic acids in EfOM were preferentially removed and the effects of competing anions on the removal of EfOM were insignificant. The MIEX treatment with added alum (only 0.5 mg Al L(-1)) dramatically improved the performance of MF and UF membranes and the subsequent membrane filtration also achieved ≤0.01 mg L(-1) of residual phosphorous. This condition also allowed good flux recovery after hydraulic flushing.

Thiol-responsive gemini poly(ethylene glycol)-poly(lactide) with a cystine disulfide spacer as an intracellular drug delivery nanocarrier

Thiol-responsive gemini micelles consisting of hydrophilic poly(ethylene glycol) (PEG) blocks and hydrophobic polylactide (PLA) blocks with a cystine disulfide spacer were reported as effective intracellular nanocarriers of drugs. In the presence of cellular glutathione (GSH) as a reducing agent, gemini micelles gradually destabilize into monomeric micelles through cleavage of the cystine linkage. This destabilization of the gemini micelles changed their size distribution, with the appearance of small aggregates, and led to the enhanced release of encapsulated doxorubicin (DOX). The results obtained from cell culture via confocal laser scanning microscopy (CLSM) for cellular uptake, as well as cell viability measurements for anticancer efficacy suggest the potential of disulfide-based gemini polymeric micelles as controlled drug delivery carriers.

Recursive approach of EEG-segment-based principal component analysis substantially reduces cryogenic pump artifacts in simultaneous EEG-fMRI data

Electroencephalography (EEG) data simultaneously acquired with functional magnetic resonance imaging (fMRI) data are preprocessed to remove gradient artifacts (GAs) and ballistocardiographic artifacts (BCAs). Nonetheless, these data, especially in the gamma frequency range, can be contaminated by residual artifacts produced by mechanical vibrations in the MRI system, in particular the cryogenic pump that compresses and transports the helium that chills the magnet (the helium-pump). However, few options are available for the removal of helium-pump artifacts. In this study, we propose a recursive approach of EEG-segment-based principal component analysis (rsPCA) that enables the removal of these helium-pump artifacts. Using the rsPCA method, feature vectors representing helium-pump artifacts were successfully extracted as eigenvectors, and the reconstructed signals of the feature vectors were subsequently removed. A test using simultaneous EEG-fMRI data acquired from left-hand (LH) and right-hand (RH) clenching tasks performed by volunteers found that the proposed rsPCA method substantially reduced helium-pump artifacts in the EEG data and significantly enhanced task-related gamma band activity levels (p=0.0038 and 0.0363 for LH and RH tasks, respectively) in EEG data that have had GAs and BCAs removed. The spatial patterns of the fMRI data were estimated using a hemodynamic response function (HRF) modeled from the estimated gamma band activity in a general linear model (GLM) framework. Active voxel clusters were identified in the post-/pre-central gyri of motor area, only from the rsPCA method (uncorrected p<0.001 for both LH/RH tasks). In addition, the superior temporal pole areas were consistently observed (uncorrected p<0.001 for the LH task and uncorrected p<0.05 for the RH task) in the spatial patterns of the HRF model for gamma band activity when the task paradigm and movement were also included in the GLM.

Genome-wide Association Study for Warner-Bratzler Shear Force and Sensory Traits in Hanwoo (Korean Cattle)

Significant SNPs associated with Warner-Bratzler (WB) shear force and sensory traits were confirmed for Hanwoo beef (Korean cattle). A Bonferroni-corrected genome-wide significant association (p<1.3×10⁻⁶) was detected with only one single nucleotide polymorphism (SNP) on chromosome 5 for WB shear force. A slightly higher number of SNPs was significantly (p<0.001) associated with WB shear force than with other sensory traits. Further, 50, 25, 29, and 34 SNPs were significantly associated with WB shear force, tenderness, juiciness, and flavor likeness, respectively. The SNPs between p = 0.001 and p = 0.0001 thresholds explained 3% to 9% of the phenotypic variance, while the most significant SNPs accounted for 7% to 12% of the phenotypic variance. In conclusion, because WB shear force and sensory evaluation were moderately affected by a few loci and minimally affected by other loci, further studies are required by using a large sample size and high marker density.

The adequacy of the distal resection margin after preoperative chemoradiotherapy for rectal cancer

AIM

The study aimed to determine the adequacy of the distal margin in patients having preoperative chemoradiotherapy (CRT) followed by restorative surgery for rectal cancer.

METHOD

A total of 368 patients with locally advanced rectal cancer treated for cure at our institution between July 1999 and March 2009 were included in the study. All underwent preoperative CRT and sphincter-sparing surgery. The distal margin and other factors were examined for their effect on recurrence and survival. The median duration of follow-up was 48 months.

RESULTS

The length of distal margin ranged from 0 to 9.0 cm (median 1.5 cm). The pelvic control and disease-free survival rates at 5 years for patients with a margin of ≤ 3 mm were no different from those in whom it was > 3 mm (P = 0.6 and 0.8). The 5-year pelvic control rates between the ≤ 3 mm and > 3 mm groups were 66.7 and 86.2% in patients with a ypT3-4 tumour (P = 0.049) and 70.0 and 89.1% in patients who showed no response to CRT (P = 0.039).

CONCLUSION

The results suggest that a distal margin of < 3 mm in the surgical specimen after preoperative CRT is associated with a lower rate of pelvic tumour control at 5 years in patients with Stage ypT3-4 tumours or in those who do not respond to CRT.

Ozonation of piggery wastewater for enhanced removal of contaminants by S. quadricauda and the impact on organic characteristics

The feasibility of using ozonation pretreatment was investigated for a better performance of post microalgae-based wastewater remediation when treating piggery effluent which was anaerobically digested and subsequently micro-filtered. Ozonation pretreatment at a dose of 1.1mg-O3 mg-C(-1) or higher significantly improved the transmittance of light illumination through the mixed liquor by decolorizing the piggery effluent as culture media, which resulted in increasing both the productivity of algal biomass and the associated removal of inorganic nutrients from the effluent. Ozonation also converted refractory organic constituents in the piggery effluent to a large number of biodegradable fractions via both partial-mineralization and low-molecularization. These fractions were facilely removed through biological assimilation during the mixotrophic cultivation of a microalga S. quadricauda. The results revealed that ozonation could be one of the most promising strategies for the pretreatment of highly-colored piggery effluent prior to algae-based wastewater treatment.

The effects of salinity on the growth and biochemical properties of Chlamydomonas mexicana GU732420 cultivated in municipal wastewater

A freshwater microalga Chlamydomonas mexicana was grown on municipal wastewater with different levels of salinity up to 400 mmol/L NaCl, and the biochemical properties were characterized after 10 days of cultivation. C. mexicana showed the higher specific growth rates for 100 and 200mmol/L NaCl. Nitrogen was completely removed within 10 days as a result of algal growth promoted by the addition of 200-400 mmol/L NaCl. Phosphorus removal increased from 77-84% as the concentration of NaCI increased from 100 to 400 mmol/L. The highest removal of total inorganic carbon (66%) was obtained with the addition of 200 mmol/L NaCl. The lipid content increased from 17% to 38% as the concentration of NaCl increased from 0 to 400mmol/L. The total fatty acid content and glycerol yield of C. mexicana increased 1.8- and 4-fold in wastewater amended with NaCl, respectively. Fatty acids accumulated in the algal biomass were mainly composed of palmitic (27-29%), y-linolenic (27-30%), and linolelaidic acids (16-18%). The optimal condition for fatty acids production in C. mexicana was observed when the municipal wastewater was amended with 100-200 mmol/L NaCl with a simultaneous removal of nutrients.

A prospective randomised comparison of two insertion methods for i-gel placement in anaesthetised paralysed patients: standard vs. rotational technique

In this prospective randomised study, we compared two techniques for i-gel(™) insertion. One hundred and eighty-one anaesthetised, paralysed adult patients were randomly allocated into one of two groups. In the standard group (n = 91), the i-gel was inserted using the standard technique. In the rotation group (n = 90), the i-gel was rotated 90° anticlockwise in the mouth and re-rotated in the hypopharynx to the original alignment. The success rate, insertion time, air leak pressure and complications were assessed. The success rate for insertion at the first attempt was lower for the standard technique, 78 (86%) vs. 87 (97%; p = 0.016). The mean (SD) insertion time was longer (26.9 (14.5) s vs. 22.4 (10.2) s; p = 0.016) and air leak pressure was lower (22.5 (10.4) cm H2O vs. 27.1 (9.4) cm H2O; p = 0.002) in the standard group. The incidence of bloodstaining was higher with the standard technique (8 (9%) vs. 1 (1%); p = 0.034). This study suggests that the rotational technique is superior to the standard technique for i-gel insertion.

Simultaneous determination of cortisol and cortisone from human serum by liquid chromatography-tandem mass spectrometry

A fast, sensitive, and selective liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was validated and then the levels of cortisol and cortisone from sera of healthy adults were determined by the LC-MS/MS method. One hundred μ L of serum sample was directly extracted by adding 2 mL ethyl acetate, followed by chromatographic separation on a C18 column with a mobile phase consisting of 5 mM ammonium acetate and methanol (25 : 75, v/v). The precision, accuracy, and average recovery of the method were 1.5-5.3%, 95.4-102.5%, and 96.4% for cortisol, and 1.9-6.0%, 89.2-98.8%, and 79.9% for cortisone, respectively. The method was linear from 1.0 to 500.0 ng/mL (r(2) = 0.999) for cortisol and 2.5 to 100.0 ng/mL (r(2) = 0.998) for cortisone. The limits of detection (LOD) and quantification (LOQ) were 0.2 and 1.0 ng/mL for cortisol, and 1.0 and 2.5 ng/mL for cortisone, respectively. The average cortisol concentration (133.9 ± 63.7 ng/mL) of samples collected between 9:00 and 11:00 a.m. was higher approximately 4.4 times than that of cortisone (30.5 ± 10.7 ng/mL) (P < 0.0001). The average cortisone/cortisol ratio was 0.225. Therefore, the LC-MS/MS method may be useful for the diagnosis of some adrenal diseases and the assessment of 11 β -hydroxysteroid dehydrogenase (11 β -HSD) activity in clinical laboratories.

CO2 selective 1D double chain dipyridyl-porphyrin based porous coordination polymers

Two CO₂ selective 1D double chain dipyridyl-porphyrin-based porous coordination polymers, Co₃(DPyP)₃·4DMF (I) and Zn₃(DPyP)₃·2DMF·4H₂O (II) are prepared from thermal reactions of MnCl(DPyP) with Co^II and Zn^II ions in DMF.

Non-invasive monitoring of ultrasound-stimulated microbubble radiation enhancement using photoacoustic imaging

Modulation of the tumour microvasculature has been demonstrated to affect the effectiveness of radiation, stimulating the search for anti-angiogenic and vascular-disrupting treatment modalities. Microbubbles stimulated by ultrasound have recently been demonstrated as a radiation enhancer when used with different cancer models including PC3. Here, photoacoustics imaging technique was used to assess this treatment’s effects on haemoglobin levels and oxygen saturation. Correlations between this modality and power doppler assessments of blood flow, and histology measurements of vascular integrity and cell death were also investigated. Xenograft prostate tumours in SCID mice were treated with 0, 2, or 8 Gy radiation combined with microbubbles exposed to 500 kHz ultrasound at a peak negative pressure of 0, 570, and 750 kPa. Tumours were assessed and levels of total haemoglobin, oxygen saturation were measured using photoacoustics before and 24 hours after treatment along with power doppler measured blood flow. Mice were then sacrificed and tumours were assessed for cell death and vascular composition using immunohistochemistry. Treatments using 8 Gy and microbubbles resulted in oxygen saturation decreasing by 28 ± 10% at 570 kPa and 25 ± 29% at 750 kPa, which corresponded to 44 ± 9% and 40 ± 14% respective decreases in blood flow as measured with power doppler. Corresponding histology indicated 31 ± 5% at 570 kPa and 37 ± 5% at 750 kPa in terms of cell death. There were drops in intact vasculature of 15 ± 2% and 20 ± 2%, for treatments at 570 kPa and 750 kPa. In summary, photoacoustic measures of total haemoglobin and oxygen saturation paralleled changes in power doppler indicators of blood flow. Destruction of tumour microvasculature with microbubble-enhanced radiation also led to decreases in blood flow and was associated with increases in cell death and decreases in intact vasculature as detected with CD31 labeling.

High-throughput on-chip leukemia diagnosis

Advances in lab-on-a-chip technologies enabled programmable, reconfigurable, and scalable manipulation of a variety of laboratory procedures. Samples, reagents, and fluids can be precisely controlled; buffer temperature, pH, and concentration control systems as well as a variety of detection systems can be integrated on a small chip. These advantages have attracted attention in various fields of clinical application including leukemia diagnosis and research. A lot of research on lab-on-a-chip based diagnosis has been reported and the field is rapidly expanding. This review describes recent developments of lab-on-a-chip technologies as solutions to challenges for high-throughput leukemia diagnosis.

Biomass, lipid content, and fatty acid composition of freshwater Chlamydomonas mexicana and Scenedesmus obliquus grown under salt stress

Two freshwater microalgae including Chlamydomonas mexicana and Scenedesmus obliquus were grown on Bold Basal Medium (BBM) with different levels of salinity up to 100 mM NaCl. The dry biomass and lipid content of microalgae were improved as the concentration of NaCl increased from 0 to 25 mM. Highest dry weight (0.8 and 0.65 g/L) and lipid content (37 and 34 %) of C. mexicana and S. obliquus, respectively, were obtained in BBM amended with 25 mM NaCl. The fatty acid composition of the investigated species was also improved by the increased NaCl concentration. At 50 mM, NaCl palmitic acid (35 %) and linoleic acid (41 %) were the dominant fatty acids in C. mexicana, while oleic acid (41 %) and α-linolenic acid (20 %) were the major fractions found in S. obliquus.

Microalgal species growing on piggery wastewater as a valuable candidate for nutrient removal and biodiesel production

Six microalgal species were examined in this study to determine their effectiveness in the coupling of piggery wastewater treatment and biodiesel production. The dry biomasses of Ourococcus multisporus, Nitzschia cf. pusilla, Chlamydomonas mexicana, Scenedesmus obliquus, Chlorella vulgaris, and Micractinium reisseri were 0.34 ± 0.08, 0.37 ± 0.13, 0.56 ± 0.35, 0.53 ± 0.30, 0.49 ± 0.26, and 0.35 ± 0.08 g dwt/L, respectively. The highest removal of nitrogen (62%), phosphorus (28%), and inorganic carbon (29%) were achieved by C. mexicana. In the absence of microalgae, the spontaneous precipitation of phosphorus, calcium, and inorganic carbon occurred at slightly alkaline pH. The highest lipid productivity and lipid content (0.31 ± 0.03 g/L and 33 ± 3%, respectively) were found in C. mexicana. The fatty acid compositions of the studied species were mainly palmitic, linoleic, α-linolenic, and oleic. The results of our study suggest that C. mexicana is one of the most promising candidates for simultaneous nutrient removal and high-efficient biodiesel production.

Comparison of the clinical characteristics and imaging findings of acute cholangitis with and without biliary dilatation

OBJECTIVE

To evaluate the causes of acute cholangitis without biliary dilatation and to compare the clinical characteristics and the imaging findings between patients with acute cholangitis with and without biliary dilatation.

METHODS

93 patients diagnosed with acute cholangitis underwent contrast-enhanced CT. Among them, 17 patients were classified as not having biliary dilatation (Group 1) and 76 patients were classified as having biliary dilatation (Group 2). The causes of acute cholangitis were evaluated in both groups. Clinical characteristics and imaging findings were compared between the two groups.

RESULTS

The causes of acute cholangitis without biliary dilatation included common bile duct (CBD) stones (n=11), CBD sludge (n=3), a passed stone (n=1) and unknown causes (n=2). The total bilirubin levels of Group 1 were significantly lower than those of Group 2 (p=0.001). By contrast, Group 1 had higher median alanine aminotransferase (ALT) levels than Group 2 (p=0.04). The length of hospital stay was significantly longer in Group 2 than in Group 1 patients (p<0.001). In the imaging findings, the extent of transient hepatic attenuation differences (THADs) (p=0.003) were significantly smaller in Group 1 than in Group 2.

CONCLUSION

CBD stones and sludge were the most common causes of acute cholangitis in patients without biliary dilatation. These patients showed lower levels of bilirubin and higher levels of ALT than those with acute cholangitis with biliary dilatation, and had a shorter duration of hospital stay. The extent of THADs was the only discriminative CT finding between the two groups.

ADVANCES IN KNOWLEDGE

Acute cholangitis can present without biliary dilatation on imaging, and the most common causes are CBD stones and sludge. The patients with acute cholangitis without biliary dilatation have different clinical characteristics and imaging findings compared with those with acute cholangitis presenting with biliary dilatation.

Ultrasonic disintegration of microalgal biomass and consequent improvement of bioaccessibility/bioavailability in microbial fermentation

BACKGROUND

Microalgal biomass contains a high level of carbohydrates which can be biochemically converted to biofuels using state-of-the-art strategies that are almost always needed to employ a robust pretreatment on the biomass for enhanced energy production. In this study, we used an ultrasonic pretreatment to convert microalgal biomass (Scenedesmus obliquus YSW15) into feasible feedstock for microbial fermentation to produce ethanol and hydrogen. The effect of sonication condition was quantitatively evaluated with emphases on the characterization of carbohydrate components in microalgal suspension and on subsequent production of fermentative bioenergy.

METHOD

Scenedesmus obliquus YSW15 was isolated from the effluent of a municipal wastewater treatment plant. The sonication durations of 0, 10, 15, and 60 min were examined under different temperatures at a fixed frequency and acoustic power resulted in morphologically different states of microalgal biomass lysis. Fermentation was performed to evaluate the bioenergy production from the non-sonicated and sonicated algal biomasses after pretreatment stage under both mesophilic (35°C) and thermophilic (55°C) conditions.

RESULTS

A 15 min sonication treatment significantly increased the concentration of dissolved carbohydrates (0.12 g g(-1)), which resulted in an increase of hydrogen/ethanol production through microbial fermentation. The bioconvertibility of microalgal biomass sonicated for 15 min or longer was comparable to starch as a control, indicating a high feasibility of using microalgae for fermentative bioenergy production. Increasing the sonication duration resulted in increases in both algal surface hydrophilicity and electrostatic repulsion among algal debris dispersed in aqueous solution. Scanning electron microscope images supported that ruptured algal cell allowed fermentative bacteria to access the inner space of the cell, evidencing an enhanced bioaccessibility. Sonication for 15 min was the best for fermentative bioenergy (hydrogen/ethanol) production from microalga, and the productivity was relatively higher for thermophilic (55°C) than mesophilic (35°C) condition.

CONCLUSION

These results demonstrate that more bioavailable carbohydrate components are produced through the ultrasonic degradation of microalgal biomass, and thus the process can provide a high quality source for fermentative bioenergy production.