Study of ceria-carbonate nanocomposite electrolytes for low-temperature solid oxide fuel cells

Composite and nanocomposite samarium doped ceria-carbonates powders were prepared by solid-state reaction, citric acid-nitrate combustion and modified nanocomposite approaches and used as electrolytes for low temperature solid oxide fuel cells. X-ray Diffraction, Scanning Electron Microscope, low-temperature Nitrogen Adsorption/desorption Experiments, Electrochemical Impedance Spectroscopy and fuel cell performance test were employed in characterization of these materials. All powders are nano-size particles with slight aggregation and carbonates are amorphous in composites. Nanocomposite electrolyte exhibits much lower impedance resistance and higher ionic conductivity than those of the other electrolytes at lower temperature. Fuel cell using the electrolyte prepared by modified nanocomposite approach exhibits the best performance in the whole operation temperature range and achieves a maximum power density of 839 mW cm(-2) at 600 degrees C with H2 as fuel. The excellent physical and electrochemical performances of nanocomposite electrolyte make it a promising candidate for low-temperature solid oxide fuel cells.

Maternal high-fat diet impacts endothelial function in nonhuman primate offspring

OBJECTIVE:

The link between maternal under-nutrition and cardiovascular disease (CVD) in the offspring later in life is well recognized, but the impact of maternal over-nutrition on the offspring's cardiovascular function and subsequent risk for CVD later in life remains unclear. Here, we investigated the impact of maternal exposure to a high-fat/calorie diet (HFD) during pregnancy and early postnatal period on endothelial function of the offspring in a nonhuman primate model.

METHODS:

Offspring, naturally born to either a control (CTR) diet (14% fat calories) or a HFD (36% fat calories) consumption dam, were breast-fed until weaning at about 8 months of age. After weaning, the offspring were either maintained on the same diet (CTR/CTR, HFD/HFD), or underwent a diet switch (CTR/HFD, HFD/CTR). Blood samples and arterial tissues were collected at necropsy when the animals were about 13 months of age.

RESULTS:

HFD/HFD juveniles displayed an increased plasma insulin level and glucose-stimulated insulin secretion in comparison with CTR/CTR. In abdominal aorta, but not the renal artery, acetylcholine-induced vasorelaxation was decreased remarkably for HFD/HFD juveniles compared with CTR/CTR. HFD/HFD animals also showed a thicker intima wall and an abnormal vascular-morphology, concurrent with elevated expression levels of several markers related to vascular inflammation and fibrinolytic function. Diet-switching animals (HFD/CTR and CTR/HFD) displayed modest damage on the abdominal vessel.

CONCLUSION:

Our data indicate that maternal HFD exposure impairs offspring's endothelial function. Both early programming events and postweaning diet contribute to the abnormalities that could be reversed partially by diet intervention.

Lymph node retrieval from colorectal resection specimens for adenocarcinoma: is it worth the extra effort to find at least 12 nodes?

AIM

Retrieval of a minimum of 12 lymph nodes has been recommended for adequately staging a node-negative colorectal cancer (CRC). This study was designed to determine whether the extra effort expended to recover more nodes for histological examination improves the accuracy of staging.

METHOD

Pathology reports, histology worklists, and haematoxylin and eosin (H&E) slides of 334 CRC resections were reviewed. The total number of nodes and the number of positive nodes harvested from the first and additional searches were recorded for each patient.

RESULTS

The number of nodes retrieved from the 334 resections at the first search ranged from 0 to 57 (mean: 14.2), with 195 patients (58.4%) having ≥ 12 nodes. Nodal metastasis was found in 122 (33.6%) patients. Additional searches were performed on 115 patients, including 91 with < 12 nodes. The mean number of nodes recovered in these patients increased significantly, from 9.1 to 14.2 (P < 0.0001). Thirty-one additional positive nodes were found in 19 patients following the further searches, and 12 (63.2%) of the 19 patients were upstaged using the American Joint Committee on Cancer (AJCC) 6th edition (2002) staging criteria. The total number of nodes retrieved and the probability of obtaining ≥ 12 nodes correlated negatively with the age of the patient and the rectosigmoid location of the tumours, but positively with the specimen length, the pericolic/perirectal fat width, female gender and tumour size.

CONCLUSION

Although a number of patient and specimen variables influence the number of lymph nodes retrieved, our observations support the importance of a thorough search for nodes in CRC specimens in order to achieve accurate tumour staging.

Multidetector CT features of pulmonary focal ground-glass opacity: differences between benign and malignant

OBJECTIVE

To evaluate different features between benign and malignant pulmonary focal ground-glass opacity (fGGO) on multidetector CT (MDCT).

METHODS

82 pathologically or clinically confirmed fGGOs were retrospectively analysed with regard to demographic data, lesion size and location, attenuation value and MDCT features including shape, margin, interface, internal characteristics and adjacent structure. Differences between benign and malignant fGGOs were analysed using a χ(2) test, Fisher's exact test or Mann-Whitney U-test. Morphological characteristics were analysed by binary logistic regression analysis to estimate the likelihood of malignancy.

RESULTS

There were 21 benign and 61 malignant lesions. No statistical differences were found between benign and malignant fGGOs in terms of demographic data, size, location and attenuation value. The frequency of lobulation (p=0.000), spiculation (p=0.008), spine-like process (p=0.004), well-defined but coarse interface (p=0.000), bronchus cut-off (p=0.003), other air-containing space (p=0.000), pleural indentation (p=0.000) and vascular convergence (p=0.006) was significantly higher in malignant fGGOs than that in benign fGGOs. Binary logistic regression analysis showed that lobulation, interface and pleural indentation were important indicators for malignant diagnosis of fGGO, with the corresponding odds ratios of 8.122, 3.139 and 9.076, respectively. In addition, a well-defined but coarse interface was the most important indicator of malignancy among all interface types. With all three important indicators considered, the diagnostic sensitivity, specificity and accuracy were 93.4%, 66.7% and 86.6%, respectively.

CONCLUSION

An fGGO with lobulation, a well-defined but coarse interface and pleural indentation gives a greater than average likelihood of being malignant.

Endophytic colonisation of Bacillus subtilis in the roots of Robinia pseudoacacia L

The endophytic colonisation of Bacillus subtilis strain GXJM08, isolated from roots of Podocarpus imbricatus B1. Enum. P1. Jav., in roots of the leguminous plant Robinia pseudoacacia L. was investigated. Ultrastructure observations showed that B. subtilis caused morphological changes in the root hair and colonised the plant through infected root hairs. The structure of the infection thread was similar to that of rhizobia, but the structure of infected cells was different. B. subtilis is also different from rhizobia and plant pathogens in terms of the formation of a peribacteroid membrane and the mode of penetration through the host cell wall. Our results provide a basis for studying development of the mutualistic symbiotic relationship between B. subtilis and plants, and a basis for studying the mechanism of the B. subtilis-plant interaction.

Inhibition of IκB Kinase β attenuates hypoxia-induced inflammatory mediators in rat renal tubular cells

OBJECTIVE

Inflammation is now believed to play a major role in the pathophysiology of ischemic acute kidney injury (AKI), which is thought to be directly regulated by nuclear factor-κB (NF-κB). Our previous study indicated that ischemic preconditioning (IPC) alleviated renal ischemic-reperfusion injury due to inhibition of IκB kinase β (IKK β) activity. Using small interfering RNA (siRNA) to silence the expression of IKKβ, which consists of the IKK complex residing at a key convergence site that leads to NF-κB activation in multiple signaling pathways, we protected organs from ischemic AKI. Herein, we have report a siRNA-based treatment to prevent ischemic AKI.

METHODS

Ischemic AKI was induced by a hypoxia-mimicking agent cobalt chloride (CoCl(2)). The therapeutic effects of IKKβ-specific siRNA were evaluated on the expression of interleukin (IL)-18, neutrophil gelatinase-associated lipocalin (NGAL), and cell apoptosis.

RESULTS

Compared with CoCl(2)-induced NRK52E cells, pretransfected IKKβ-specific siRNA reduced the expression of IL-18 and NGAL to 62.5% and 50.4% in messenger RNA (mRNA) and to 57.2% and 62.7% in protein levels, respectively. The necrosis index in the IKKβ-specific siRNA transfected group was decreased compared with a nonspecific siRNA transfected group.

CONCLUSIONS

These data revealed that hypoxia-induced inflammatory responses were IKKβ/NF-κB-dependent. Knockdown of IKKβ by siRNA suppressed the transcription IKKβ/NF-κB-mediated inflammatory mediators in tumor necrosis factor-α or CoCl(2)-treated tubular epithelial cells, and decreased CoCl(2)-induced cell death, which may be a useful, preventive and therapeutic strategy for ischemic AKI.

Minocycline may be useful to prevent/treat postoperative cognitive decline in elderly patients

Postoperative cognitive dysfunction (POCD) is reported to occur frequently after all types especially cardiac surgery in elderly patients. It can be short-term or long-term and some cases even develop into Alzheimer's disease (AD). Although multi-risk factors associated with POCD have been identified, the etiology and pathophysiological mechanisms of this surgical complication remain elusive. Therefore, developing strategies for preventing or treating POCD is still challenging. However, increasing evidence suggests that central and systemic inflammation triggered by surgery likely plays a fundamental role in POCD developing and progression. Minocycline, a tetracycline derivative with anti-inflammatory properties, has been shown to be effective in treating neuroinflammatory related conditions or neurodegenerative diseases such as AD, Parkinson's disease, Huntington's disease. Considering that inflammation may be a potential factor of POCD and minocycline is effective in improving cognitive dysfunction induced by inflammation, we hypothesize that minocycline may be useful to treat/prevent the POCD development after surgery in elderly patients.

Potential of UV/H2O2 oxidation for enhancing the biodegradability of municipal reverse osmosis concentrates

UVC/H2O2 and VUV/H2O2 oxidation processes were evaluated for the degradation of organic pollutants in reverse osmosis concentrate (ROC) produced from a municipal secondary effluent. It was found that the oxidation by UVC/H2O2 and VUV/H2O2 processes could be described as a pseudo first-order reaction. For UVC increased oxidation occurred with increasing H2O2 dosage up to 2 mM above which improvement in oxidation performance decreased. At the same H2O2 dosage, VUV irradiation gave better overall oxidation performance. Compared with UVC/6 mM H2O2, VUV/2 mM H2O2 gave a greater rate of reduction of chemical oxygen demand, but a lower rate for reduction of dissolved organic carbon, suggesting that oxidation of organics by the two methods followed different pathways. The change of absorbance at 254 nm and fluorescence excitation emission matrix spectra of irradiated samples indicated that the large and complex compounds were fragmented rapidly by the *OH, resulting in rapid decolourisation. The biodegradability of the organics in the ROC was increased from 11% to 35% after 1 h treatment by UVC/3 mM H2O2, whereas a greater increase (41%) was obtained with VUV/2 mM H2O2. This increase in biodegradability indicates the potential for employing a subsequent biological treatment process.

Uterine rupture during pregnancy

BACKGROUND

Despite great advances in modern obstetrics, uterine rupture (UR) remains one of the most frightening complications with high morbidity and mortality.

OBJECTIVE

To improve the diagnosis and management of UR.

RESULTS

We report two cases of UR. Case 1 was spontaneous UR and case 2 was associated with a scar in the patient's uterus. Interestingly, the ruptured scar was not a scar from a previous cesarean section; it was a scar that was associated with placenta accreta. The fetal heart rates in both cases were below 80 beats per minute after UR. The newborn in case 1 died soon after delivery, while the newborn in case 2 survived. Both women were healthy and were discharged from hospital two to three weeks after surgery.

CONCLUSION

UR can occur in a previously unscarred uterus or from a scar of a cesarean section or scars caused by other pathologic lesions in the uterus. Severe fetal bradycardia might be a strong indicator for UR. Such study will help obstetricians provide more careful measures to manage UR, so that its morbidity and mortality can be decreased.

Effect of glycyrrhizin on CYP2C19 and CYP3A4 activity in healthy volunteers with different CYP2C19 genotypes

The objective of this study was to investigate the interaction between glycyrrhizin and omeprazole and observe the effects of glycyrrhizin on CYP2C19 and CYP3A4 activities in healthy Chinese male volunteers with different CYP2C19 genotypes. Eighteen healthy subjects (six CYP2C19*1/*1, five CYP2C19*1/*2, one CYP2C19*1/*3, five CYP2C19*2/*2 and one CYP2C19*2/*3) were enrolled in a two-phase randomized crossover trial. In each phase, all subjects received placebo or glycyrrhizin salt tablet 150 mg twice daily for 14 consecutive days. The pharmacokinetics of omeprazole (20 mg orally on day 15) was determined for up to 12 h following administration by high-performance liquid chromatography. After 14-day treatment of glycyrrhizin, plasma omeprazole significantly decreased, and those of omeprazole sulfone significantly increased. However, plasma concenetrations of 5-hydroxyomeprazole did not significantly change. The ratio of AUC(0-infinity) of omeprazole to omeprazole sulfone decreased by 43.93% + or - 13.56% (p = 0.009) in CYP2C19*1/*1, 44.85% + or - 14.84% (p = 0.002) in CYP2C19*1/*2 or *3 and 36.16% + or - 7.52% (p < 0.001) in CYP2C19*2/*2 or *3 while those of omeprazole to 5-hydroxyomeprazole did not change significantly in all three genotypes. No significant differences in glycyrrhizin response were found among CYP2C19 genotypes. Glycyrrhizin induces CYP3A4-catalyzed sulfoxidation of omeprazole and leads to decreased omeprazole plasma concentrations, but has no significant impact on CYP2C19-dependent hydroxylation of omeprazole.