Reduced field-of-view diffusion-weighted imaging (DWI) in patients with gastric cancer: Comparison with conventional DWI techniques at 3.0T: A preliminary study.

To evaluate the qualitative image quality and quantitative apparent diffusion coefficient (ADC) value of reduced field-of view (rFOV) and full field-of-view (fFOV) diffusion-weighted imaging (DWI) sequences at 3.0 T in patients with gastric cancer.Fifty-three patients (37 males, 16 females; mean age, 63.3 ±â€Š10.3 years) with 60 lesions with gastric cancer who underwent magnetic resonance (MR) scans, including both rFOV-DWI and fFOV-DWI, were retrospectively analyzed. Two observers subjectively evaluated image quality for both the fFOV-DWI and rFOV-DWI sequences regarding the anatomic details, distortion, lesion conspicuity, artifacts, and overall image quality. The mean ADC values of gastric cancer were calculated. The Wilcoxon test and paired samples t test were used. Interobserver agreement was assessed using kappa statistics.The mean scores based on the 2 observers demonstrated significant differences in image quality in terms of anatomic details, distortion, lesion conspicuity, artifacts and overall image quality at both b values between rFOV-DWI and fFOV-DWI (P < .05) in the whole gastric area. rFOV-DWI yielded significantly better scores in image quality at b = 800 seconds/mm (P < .05) in patients with esophagogastric junction cancers, but there were no significant differences in the gastric corpus and gastric antrum region. The mean tumor ADC values of rFOV-DWI were significantly lower than those of fFOV-DWI (1.237 ±â€Š0.228 × 10-3 mm/second vs 1.683 ±â€Š0.322 × 10-3 mm/second, P < .001).rFOV-DWI yielded significantly better image quality (anatomic details, distortion, lesion conspicuity, artifacts, overall image quality) and more accurate ADC measurements than fFOV-DWI did.

Characterization of a laccase from a wood-feeding termite, Coptotermes formosanus.

Coptotermes formosanus Shiraki is a wood-feeding termite which secretes a series of lignolytic and cellulolytic enzymes for woody biomass degradation. However, the lignin modification mechanism in the termite is largely elusive, and the characteristics of most lignolytic enzymes in termites remain unknown. In this study, a laccase gene lac1 from C. formosanus was heterogeneously expressed in insect Sf9 cells. The purified Lac1 showed strong activities toward hydroquinone (305 mU/mg) and 2,6-dimethoxyphenol (2.9 mU/mg) with low Km values, but not veratryl alcohol or 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid). Lac1 could function well from pH 4.5 to 7.5, and its activity was significantly inhibited by H2 O2 at above 4.85 mmol/L (P < 0.01). In addition, the lac1 gene was found to be mainly expressed in the salivary glands and foregut of C. formosanus, and seldom in the midgut or hindgut. These findings suggested that Lac1 is a phenol-oxidizing laccase like RflacA and RflacB from termite Reticulitermes flavipes, except that Lac1 was found to be more efficient in phenol oxidation, and it did not require H2 O2 for its function. It is suspected that this kind of termite laccase might only be able to directly oxidize low redox-potential substrates, and the high redox-potential groups in lignin might be oxidized by other enzymes in the termite or by using the Fenton reaction.

Preoperative Aspirin Does Not Increase Transfusion or Reoperation in Isolated Valve Surgery.

OBJECTIVE: Preoperative aspirin has been studied in patients undergoing isolated coronary artery bypass graft surgery. However, there is a paucity of clinical data available evaluating perioperative aspirin in other cardiac surgical procedures. This study was designed to investigate the effects of aspirin on bleeding and transfusion in patients undergoing non-emergent, isolated, heart valve repair or replacement. DESIGN: Retrospective, cohort study. SETTING: Academic medical center. PARTICIPANTS: A total of 694 consecutive patients having non-emergent, isolated, valve repair or replacement surgery at an academic medical center were identified. INTERVENTIONS: Of the 488 patients who met inclusion criteria, 2 groups were defined based on their preoperative use of aspirin: those taking (n = 282), and those not taking (n = 206) aspirin within 5 days of surgery. MEASUREMENTS AND MAIN RESULTS: Binary logistic regression was used to examine relationships among demographic and clinical variables. No significant difference was found between the aspirin and non-aspirin groups with respect to the percentage receiving red blood cell (RBC) transfusion, mean RBC units transfused in those who required transfusion, massive transfusion of RBC, or amounts of fresh frozen plasma, cryoprecipitate, or platelets. Aspirin was not associated with an increase in the rate of re-exploration for bleeding (5.3% v 6.3%, p = 0.478). Major adverse cardiocerebral events (MACE), 30-day mortality, and 30-day readmission rates were not statistically different between the aspirin-and non-aspirin-treated groups. CONCLUSIONS: Preoperative aspirin therapy in elective, isolated, valve surgery did not result in an increase in transfusion or reoperation for bleeding and was not associated with reduced readmission rate, MACE, or 30-day mortality.

Three-Dimensional Electrodes for High-Performance Bioelectrochemical Systems.

Bioelectrochemical systems (BES) are groups of bioelectrochemical technologies and platforms that could facilitate versatile environmental and biological applications. The performance of BES is mainly determined by the key process of electron transfer at the bacteria and electrode interface, which is known as extracellular electron transfer (EET). Thus, developing novel electrodes to encourage bacteria attachment and enhance EET efficiency is of great significance. Recently, three-dimensional (3D) electrodes, which provide large specific area for bacteria attachment and macroporous structures for substrate diffusion, have emerged as a promising electrode for high-performance BES. Herein, a comprehensive review of versatile methodology developed for 3D electrode fabrication is presented. This review article is organized based on the categorization of 3D electrode fabrication strategy and BES performance comparison. In particular, the advantages and shortcomings of these 3D electrodes are presented and their future development is discussed.

Enhanced power production from microbial fuel cells with high cell density culture.

Improvement of power production in a microbial fuel cell (MFC) with a high cell density culture strategy was developed. By using high cell density culture, the voltage output and power density output of the MFC were enhanced about 0.6 and 1.6 times compared to the control, respectively. Further analysis showed that riboflavin concentration in the MFC was dramatically increased from 0.1 mg/L to 1.2 mg/L by high cell density culture. Moreover, the biofilm formation on the anode surface was significantly enhanced by this new strategy. The increased accumulation of electron shuttle (riboflavin) as well as enhanced biofilm formation contributed to the improvement in anodic electrochemical activity and these factors were the underlying mechanism for MFC performance improvement by high cell density culture. This work demonstrated that high cell density culture would be a simple and practical strategy for MFC manipulation.

Effects of RNA interference-mediated knockdown of livin and survivin using monomethoxypolyethylene glycol-chitosan nanoparticles in MG-63 osteosarcoma cells.

MG-63 human osteosarcoma cells were transfected with short hairpin RNA (shRNA) against livin and survivin using monomethoxypolyethylene glycol­chitosan (mPEG­CS) nanoparticles (NPs) as carriers, with the aim of evaluating the effect on cell proliferation and apoptosis. mPEG­CS NPs sized ~100 nm were prepared by ionic crosslinking. mPEG­CS­livin shRNA, mPEG­CS­survivin shRNA and mPEG­CS­(livin shRNA + survivin shRNA) NPs were constructed by electrostatic adsorption at NP suspension/gene solution ratios of 3:1 to transfect MG­63 cells. The expression levels of livin and survivin mRNA and protein were measured by reverse transcription­polymerase chain reaction and western blotting, respectively. The inhibitory effects of downregulated livin and survivin expression on cell proliferation were measured using an MTT assay. The apoptosis­inducing effects of livin and surivin knockdown were investigated using a Hoechst staining kit. All shRNA groups resulted in reduced expression of livin and survivin mRNA and protein in MG­63 cells. The MTT assay and Hoechst staining indicated that simultaneous knockdown of livin and survivin genes inhibited the proliferation of MG­63 cells and promoted their apoptosis, to a greater extent than knocking down either gene individually. The simultaneous interference mediated by mPEG­CS NPs significantly reduced livin and survivin expression in MG­63 cells, suppressed proliferation and facilitated apoptosis, to a greater extent than knockdown of either livin or survivin alone were. Thus the results indicate a synergistic effect of livin and survivin.

Prevention and Treatment of Cardiac Surgery Associated Acute Kidney Injury.

AIM OF REVIEW: Acute kidney injury (AKI) after cardiac surgery is a relatively common postoperative complication and is independently related to increased mortality and morbidity. METHOD: In this review, we will focus on risk factors of developing AKI, early detection by biomarkers and preventive strategies for AKI after adult cardiac surgery. RECENT FINDINGS: Many perioperative factors affect renal function and acute AKI following cardiac surgery. Novel biomarkers of kidney injury such as neutrophil gelatinase-associated lipocalin (NGAL), interleukin-18 (IL-18), cystatin C (CysC), have the potential to facilitate the early diagnosis of cardiac surgery associated AKI (CSA-AKI). Pharmacological interventions have been inconsistent to their efficacy, and to date, there is no compelling pharmacologic agent known to reduce the risk of AKI or treat established AKI. SUMMARY: Preventive strategies of AKI focus on optimal perioperative management.

Enhancement of power production with tartaric acid doped polyaniline nanowire network modified anode in microbial fuel cells.

The feasibility to use tartaric acid doped PANI for MFC anode modification was determined. Uniform PANI nanowires doped with tartaric acid were synthesized and formed mesoporous networks on the carbon cloth surface. By using this tartaric acid doped PANI modified carbon cloth (PANI-TA) as the anode, the voltage output (435 ± 15 mV) and power output (490 ± 12 mW/m(2)) of MFC were enhanced by 1.6 times and 4.1 times compared to that of MFC with plain carbon cloth anode, respectively. Strikingly, the performance of PANI-TA MFC was superior to that of the MFCs with inorganic acids doped PNAI modified anode. These results substantiated that tartaric acid is a promising PANI dopant for MFC anode modification, and provided new opportunity for MFC performance improvement.

Microbial fuel cell-based biosensors for environmental monitoring: a review.

The microbial fuel cell (MFC) is an innovative technology that was initially designed to harness energy from organic waste using microorganisms. It is striking how many promising applications beyond energy production have been explored in recent decades. In particular, MFC-based biosensors are considered to be the next generation biosensing technology for environmental monitoring. This review describes recent advances in this emerging technology of MFC-based biosensors, with a special emphasis on monitoring of biochemical oxygen demand and toxicity in the environment. The progress confirms that MFC-based biosensors could be used as self-powered portable biosensing devices with great potential in long-term and remote environmental monitoring.

Engineering quorum sensing signaling of Pseudomonas for enhanced wastewater treatment and electricity harvest: A review.

Cell-cell communication that enables synchronized population behaviors in microbial communities dictates various biological processes. It is of great interest to unveil the underlying mechanisms of fine-tuning cell-cell communication to achieve environmental and energy applications. Pseudomonas is a ubiquitous microbe in environments that had wide applications in bioremediation and bioenergy generation. The quorum sensing (QS, a generic cell-cell communication mechanism) systems of Pseudomonas underlie the aromatics biodegradation, denitrification and electricity harvest. Here, we reviewed the recent progresses of the genetic strategies in engineering QS circuits to improve efficiency of wastewater treatment and the performance of microbial fuel cells.

[Signifiance of brush sign on susceptibility-weighted imaging predicts hemorrhagic transformation after intravenous thrombolysis in patients with acute ischemic stroke].

OBJECTIVE: To assess brush sign (BS) on susceptibility-weighted imaging (SWI) in prediction of hemorrhagic transformation (HT) in patients with acute ischemic stroke (AIS) after intravenous thrombolysis(IVT). METHODS: Patients with acute cerebral ischemic stroke, who had major cerebral artery occlusion (internal carotid artery, middle cerebral artery M1 and M2), treated with intravenous recombinant tissue plasminogen activator (rt-PA) from August 2009 to October 2014 in the Second Affiliated Hospital, Zhejiang University School of Medicine, were enrolled in the study. All patients underwent SWI scanning. The asymmetry index (AI) was defined as the difference of intensity between ischemic and normal hemispheres on the SWI phase map; according to AI values patients were divided into 3 groups: BS=0(n=9), BS=1 (n=39) and BS=2 (n=18). The relationships between BS and HT and the clinical outcome among the 3 groups were analyzed. RESULTS: Sixty-six patients aged 68 ± 13 years were included in the study, including 44 males (67%) and 22 females (33%), and 44 (67%) with acute ischemic stroke. The mean pre-treatment National Institutes of Health Stroke Scale (NIHSS) score was 13 (6-17), and the onset to needle time was (252 ± 88) min. Twenty-six (39.4%) patients had HT, including 18 cases (27.3%) with HI and 8 cases (12.1%) with PH; BS was observed more frequently in HT group than non-HT group. Binary logistic regression analysis showed that BS was independently associated with HT of patients with acute ischemic stroke following IVT (OR=2.589, 95% CI: 1.080-6.210, P=0.033). In those without reperfusion after IVT, patients with higher BS grade had higher HT rate (P=0.023). CONCLUSION: Brush sign on SWI can be used for predicting hemorrhagic transformation after intravenous thrombolysis in patients with acute ischemic stroke.

[Cerebral lesions of DWI hyperintensity in patients with subacute stroke assessed by intravoxel incoherent motion technique].

OBJECTIVE: To investigate the cerebral lesions of diffusion weighted imaging (DWI) hyperintensity in patients with subacute stroke with intravoxel incoherent motion (IVIM) technique. METHODS: The clinical data of 20 patients with ischemic stroke (3 to 7 d after onset) who underwent DWI and IVIM scanning between June 2014 and July 2015, were retrospectively analyzed. The parameters from IVIM including slow diffusion coefficient (D), fast diffusion coefficient (D(*)) and perfusion fraction (f) were processed. DWI hyperintensity was segmented by its signal intensity greater than the mean+2 standard deviations of the value in the homologous contralateral region. Then, DWI hyperintensity was classified into two regions of interest (ROIs): infarction core and peri-core with the ADC threshold of 0.55 × 10⁻³ mm²/s. The mirrored ROIs of infarction core and peri-core were also obtained. Then, we measured the values of ADC and D, D(*) and f in these ROIs. The ratios of ADC (rADC), D (rD), D(*) (rD(*)) and f (rf) were also calculated (e.g., rADC=ADCinfarction core/ADCmirrored region). RESULTS: Compared with mirrored region, ADC, D and f in the infarction core region decreased by 45% (P<0.001), 42% (P<0.001) and 32% (P<0.001), respectively; while ADC, D and f in the peri-core region decreased by 22% (P<0.001), 32% (P<0.001) and 8% (P=0.009), respectively. The values of rADC, rD, rD(*) and rf in the infarction core region were significantly lower than those in the peri-core region (all P<0.001). Pearson analysis showed that rADC was positively correlated with rf in the peri-core region (r=0.467, P=0.038). CONCLUSION: During subacute stage of stroke, compared to the infarction core region within DWI hyperintensity, D and f increase in the peri-core region of DWI hyperintensity, reflecting the increased water diffusion in microstructure and perfusion volume in microvasculature. This result shows that the potential reason for the heterogeneous ADC signal is associated with the disappearance of cellular edema and microvascular compensatory with increased blood volume.

Adsorption and removal of triphenylmethane dyes from water by magnetic reduced graphene oxide.

Triphenylmethane (TPM) dye is one of the most prevalent and recalcitrant water contaminants. Magnetic reduced graphene oxide (rGO) is an efficient adsorbent for organic pollutants removal. However, the performance and adsorption kinetics of magnetic rGO towards TPM have not yet been studied. In this study, a magnetic Fe3O4@rGO nano-composite, which could be easily removed from water with a simple magnetic separation step was synthesized and characterized. The magnetic rGO showed fast adsorption rate and high adsorption capacity towards different TPM dyes (the Langmuir monolayer adsorption capacity is 64.93 mg/g for adsorption of crystal violet). The adsorption processes are well-fitted to the pseudo-second-order kinetic model (R(2) > 0.99) and the Langmuir isotherm model (R(2) = 0.9996). Moreover, the magnetic rGO also showed excellent recycling and regeneration capabilities. The results indicated that adsorption with magnetic rGO would be a promising strategy to clean up the TPM contamination.

Preliminary Study on Hepatocyte-Targeted Phosphorus-31 MRS Using ATP-Loaded Galactosylated Chitosan Oligosaccharide Nanoparticles.

Background. The clinical applications of hepatic phosphorus-31 magnetic resonance spectroscopy (31P MRS) remain to be difficult because the changes of phosphates between normal hepatic tissues and pathological tissues are not so obvious, and furthermore, up to now there is few literature on hepatocyte-targeted 31P MRS. Materials and Methods. The ATP-loaded Gal-CSO (Gal-CSO/ATP) nanoparticles were prepared and the special cellular uptake of them as evaluated by using HepG-2 tumor cells and A549 tumor cells, respectively. Two kinds of cells were incubated with the nanoparticles suspension, respectively. Then were prepared the cell samples and the enhancement efficiency of ATP peaks detected by 31P MRS was evaluated. Results. The cellular uptake rate of Gal-CSO/ATP nanoparticles in HepG-2 cells was higher than that in A549 cells. Furthermore, the enlarged ATP peaks of Gal-CSO/ATP nanoparticles in HepG-2 cells were higher than those in A549 cells in vitro detected by 31P MRS. Conclusions. Gal-CSO/ATP nanoparticles have significant targeting efficiency in hepatic cells in vitro and enhancement efficiency of ATP peaks in HepG-2 cells. Furthermore, 31P MRS could be applied in the research of hepatic molecular imaging.

Increase of riboflavin biosynthesis underlies enhancement of extracellular electron transfer of Shewanella in alkaline microbial fuel cells.

Electrolyte pH tremendously affects the electricity output of microbial fuel cells. However, its underlying molecular mechanism remains elusive, in particular for Shewanella oneidensis MR-1, one of the most widely adopted electrogenic microorganisms. Herein, we found that MFCs were able to deliver a significant (but different) electricity output in a wide range of pH (from 6 to 10), with the maximum at pH=9 (alkaline), which delivers ∼1.5times' higher power output than that at pH=7 (neutral). Furthermore, cyclic voltammetry analysis showed an enhanced electrochemical activity of riboflavin (responsible for extracellular electron transfer of Shewanella) at alkaline pH. Strikingly, the concentration of riboflavin synthesized by Shewanella in MFCs at different pH showed a good correlation with the electricity output of MFCs. Thus, our results substantiated that the increase of riboflavin biosynthesis by Shewanella at the alkaline condition underlies the improvement of the electricity output in MFCs.

Evaluation of brain iron content based on magnetic resonance imaging (MRI): comparison among phase value, R2* and magnitude signal intensity.

BACKGROUND AND PURPOSE: Several magnetic resonance imaging (MRI) techniques are being exploited to measure brain iron levels increasingly as iron deposition has been implicated in some neurodegenerative diseases. However, there remains no unified evaluation of these methods as postmortem measurement isn't commonly available as the reference standard. The purpose of this study was to make a comparison among these methods and try to find a new index of brain iron. METHODS: We measured both phase values and R2* in twenty-four adults, and performed correlation analysis among the two methods and the previously published iron concentrations. We also proposed a new method using magnitude signal intensity and compared it with R2* and brain iron. RESULTS: We found phase value correlated with R2* in substantia nigra (r = -0.723, p<0.001) and putamen (r = -0.514, p = 0.010), while no correlations in red nucleus (r = -0.236, p = 0.268) and globus pallidus (r = -0.111, p = 0.605). And the new magnitude method had significant correlations in red nucleus (r = -0.593, p = 0.002), substantia nigra (r = -0.521, p = 0.009), globus pallidus (r = -0.750, p<0.001) and putamen (r = -0.547, p = 0.006) with R2*. A strong inverse correlation was also found between the new magnitude method and previously published iron concentrations in seven brain regions (r = -0.982, P<0.001). CONCLUSIONS: Our study indicates that phase value may not be used for assessing the iron content in some brain regions especially globus pallidus. The new magnitude method is highly consistent with R2* especially in globus pallidus, and we assume that this approach may be acceptable as an index of iron content in iron-rich brain regions.