The Synthesis and Properties of High Pure δ Layered Sodium Disilicate

δ layered sodium disilicate (δ-Na2Si2O5) is a single layer silicate and has good properties as detergent builder. However, it is difficult to synthesize high pure δ-Na2Si2O5. In this paper, a feasible and simple technology was found by decreasing Na content in liquid sodium silicate (water glass). The crystalline time was short and no seed needed. The suitable synthesis conditions were Si/Na = 1.05–1.10, calcining at 720 °C for 5 minutes. The synthesis conditions are of industrial value. XRD and 29Si NMR data proved that synthesized samples were δ-Na2Si2O5 without impure phase. High pure δ-Na2Si2O5 exhibited good ions binding ability and reached 312 to 338 mg CaCO3/g.

Modification of photosynthesis and growth responses to elevated CO₂ by ozone in two cultivars of winter wheat with different years of release

The beneficial effects of elevated CO2 on plants are expected to be compromised by the negative effects posed by other global changes. However, little is known about ozone (O3)-induced modulation of elevated CO2 response in plants with differential sensitivity to O3. An old (Triticum aestivum cv. Beijing 6, O3 tolerant) and a modern (T. aestivum cv. Zhongmai 9, O3 sensitive) winter wheat cultivar were exposed to elevated CO2 (714 ppm) and/or O3 (72 ppb, for 7h d(-1)) in open-topped chambers for 21 d. Plant responses to treatments were assessed by visible leaf symptoms, simultaneous measurements of gas exchange and chlorophyll a fluorescence, in vivo biochemical properties, and growth. It was found that elevated CO2 resulted in higher growth stimulation in the modern cultivar attributed to a higher energy capture and electron transport rate compared with the old cultivar. Exposure to O3 caused a greater growth reduction in the modern cultivar due to higher O3 uptake and a greater loss of photosystem II efficiency (mature leaf) and mesophyll cell activity (young leaf) than in the old cultivar. Elevated CO2 completely protected both cultivars against the deleterious effects of O3 under elevated CO2 and O3. The modern cultivar showed a greater relative loss of elevated CO2-induced growth stimulation due to higher O3 uptake and greater O3-induced photoinhibition than the old cultivar at elevated CO2 and O3. Our findings suggest that the elevated CO2-induced growth stimulation in the modern cultivar attributed to higher energy capture and electron transport rate can be compromised by its higher O3 uptake and greater O3-induced photoinhibition under elevated CO2 and O3 exposure.

Synthesis and Properties of Al-δ Layered Sodium Disilicate with High Framework Stability

Al-δ layered sodium disilicate with high framework stability in hot water (60–80°C) has been successfully synthesized from the system of Na2O–Al2O3–SiO2–H2O. It was shown that the presence of aluminum can improve the purity of δ phase. After marinated in hot distilled water for 60minutes, Al-δ layered sodium disilicate still kept δ phase and had better Ca2+ binding capacity and calcium binding rate. This property of Al-δ layered sodium disilicate may extend its application field. The samples were characterized by XRD, FT-IR, MAS NMR, Ca2+ binding capacity and rate, The data of 27Al MAS NMR and 29Si MAS NMR showed that aluminum was incorporated essentially in tetrahedral framework position, and substitute for SiO4 tetrahedron in sheet of δ layered sodium disilicate.

Hydrolysis of α, β-Layered Sodium Disilicate in Ions Binding Process

In different type water, the hydrolysis of α, β-Na2Si2O5 was investigated near washing clothing concentration by XRD, SEM chemical analysis and residual solid yield. β-Na2Si2O5 changed to kanemite in distilled water. In water with Ca2+ or Mg2+, β-Na2Si2O5 transformed to a mixture of kanemite, Ca(OH)2 and amorphous silicate or a mixture of kanemite (NaHSi2O5 ·3 H2O), Mg(OH)2 and amorphous silicate. α-Na2Si2O5 changed to an unknown phase in distilled water. In water with Ca2+ or Mg2+, α-Na2Si2O5 transformed to a mixture of unknown phase, Ca(OH)2 and amorphous silicate or a mixture of unknown phase, Mg(OH)2 and amorphous silicate. The experimental data showed that the divalent cation binding process of α, β-Na2Si2O5 belongs to a mixture process with divalent cations exchange with Na+ cation and precipitation in form of insoluble amorphous solid.

Molecular diversity of class 2 integrons in antibiotic-resistant gram-negative bacteria found in wastewater environments in China

The molecular architecture of class 2 integrons among gram-negative bacteria from wastewater environments was investigated in Jinan, China. Out of the 391 antibiotic-resistant bacteria found, 38 isolates harboring class 2 integrons encoding potentially transferrable genes that could confer antibiotic resistance were found. These isolates were classified into 19 REP-PCR types. These strains were identified using 16S rRNA gene sequencing and found to be as follows: Proteus mirabilis (16), Escherichia coli (7), Providencia spp. (7), Proteus spp. (2), P. vulgaris (3), Shigella sp. (1), Citrobacter freundii (1), and Acinetobacter sp. (1). Their class 2 integron cassette arrays were amplified and then either analyzed using PCR-RFLP or sequenced. The typical array dfrA1-sat2-aadA1 was detected in 27 isolates. Six atypical arrays were observed, including three kinds of novel arrangements (linF2(∆attC1)-dfrA1(∆attC2)-aadA1-orf441 or linF2(∆attC1)-dfrA1(∆attC2)-aadA1, dfrA1-catB2-sat2-aadA1, and estX(Vr)-sat2-aadA1) and a hybrid with the 3'CS of class 1 integrons (dfrA1-sat2-aadA1-qacH), and dfrA1-sat1. Twenty-four isolates were also found to carry class 1 integrons with 10 types of gene cassette arrays. Several non-integron-associated antibiotic resistance genes were found, and their transferability was investigated. Results showed that water sources in the Jinan region harbored a diverse community of both typical and atypical class 2 integrons, raising concerns about the overuse of antibiotics and their careless disposal into the environment.

Hydrolysis of δ-Layered Sodium Disilicate in Ions Binding Process

In different type water, the hydrolysis of δ-modification layered sodium disilicate (δ-Na2Si2O5) was investigated by employing XRD, FT-IR, SEM chemical analysis and residual solid yield. δ-Na2Si2O5 was transported to another layered sodium silicate-kanemite (NaHSi2O5·3H2O with cation exchange ability) in distilled water near the concentration in a magnitude, which is used by washing clothing. At the same concentration, δ-Na2Si2O5 changed to a mixture of kanemite, Ca(OH)2 and insoluble amorphous solid in water with Ca2+ cations; a mixture of kanemite and insoluble amorphous solid in water with Mg2+ cations. The evidence which δ-Na2Si2O5 partly transport to another ion exchangeable single layer silicate (kanemite) indicated the existence of cation exchange on δ-Na2Si2O5. Another evidence which δ-Na2Si2O5 partly dissolve and react with Ca2+ and Mg2+ cations indicated the existence to form precipitation. The experimental data suggested that the divalent cation binding process of δ-Na2Si2O5 belongs to a mixture process with divalent cations exchange with Na+ cation and precipitation in form of insoluble amorphous solid.

Dual-source CT coronary angiography involving injection protocol with iodine load tailored to patient body weight and body mass index: estimation of optimal contrast material dose

BACKGROUND

Body mass index (BMI) has a positive linear influence on arterial attenuation at coronary CT angiography involving injection protocol with dose linearly tailored to body weight (BW). Excessive contrast material may inadvertently be given in heavier patients when the dose is determined by BW only.

PURPOSE

To investigate the effect of injection protocol with dose of contrast material (CM) tailored to BW and BMI on coronary arterial attenuation, contrast-to-noise ratio, and image noise at dual-source CT coronary angiography (DSCT-CA).

MATERIAL AND METHODS

A total of 233 consecutive patients (mean age, 60.2 years) undergoing DSCT-CA were included. Image acquisition protocol was standardized (120 kV, 380 mAs, and retrospective electrocardiograph-triggered DSCT-CA). CM dosage calculation was randomly categorized into groups: a BW group and a BW-BMI group. CM flow rate in both groups was calculated as dosage divided by scan time plus 8 s. Correlations between BW, BMI, and attenuations of ascending aorta (AA) above coronary ostia, left main coronary artery (LM), proximal right coronary artery (RCA), left anterior descending (LAD), and left circumflex artery (LCX), contrast to noise ratio of LM (LMCNR) and RCA (RCACNR), and image noise were evaluated with simple linear regression for two groups individually.

RESULTS

In BW group, attenuations of AA and coronary arteries showed positive linear correlations to BW and BMI. In contrast, no relationships were found in BW-BMI group. LMCNR and RCACNR were inversely determined by BW and BMI in both groups. Image noise increased with BW and BMI increasing in two groups.

CONCLUSION

BMI has a positive linear influence on arterial attenuation with fixed iodine per BW. The injection protocol with CM dose tailored to BW and BMI is reasonable during DSCT-CA.

S-allyl cysteine restores erectile function through inhibition of reactive oxygen species generation in diabetic rats

Excessive production of reactive oxygen species (ROS) by an overactive nicotinamide adenine dinucleotide phosphate (NADPH) oxidase system in penile tissue is an important mechanism of erectile dysfunction (ED). S-allyl cysteine (SAC), a bioactive component derived from garlic, was recently reported to exert versatile antioxidant properties. We hypothesized that SAC would be able to resolve diabetes-related ED by reducing ROS generation, and designed this study to investigate this possibility as well as to determine the related underlying mechanisms. A streptozotocin-induced diabetes rat model was established and used for comparative analysis of 4-week treatment regimens with insulin or SAC. The ratio of maximal intracavernous pressure (ICP) to mean arterial blood pressure (MAP) was measured to determine erectile function. Differential levels of ROS, NADPH oxidase subunits, nitric oxide (NO)/cyclic guanosine monophosphate (cGMP) signalling pathway, and apoptosis were evaluated in cavernous tissues. Max ICP/MAP was found to be markedly decreased in untreated diabetic rats; SAC, but not insulin, treatment restored the ratio to baseline (in non-diabetic untreated controls). The corpus cavernosum of untreated diabetic rats showed increased p47(phox) and p67(phox) expression, ROS production and penile apoptotic index, and decreased phospho-endothelial nitric oxide synthase (phospho-eNOS, Ser1177) expression, cGMP concentration, B-cell lymphoma 2 (Bcl-2)/Bcl-2-associated X protein (Bax) ratio and smooth muscle cell number. SAC treatment normalized all the diabetes-induced effects, whereas insulin treatment partially normalized the alterations, but produced no effects on P47(phox) expression, penile ROS level, apoptotic index, Bcl-2/Bax ratio and smooth muscle cell number. Collectively, these data indicate that SAC treatment can restore erectile function in diabetic rats by preventing ROS formation through modulation of NADPH oxidase subunit expression. Furthermore, the poor efficacy of conventional insulin treatment for diabetic ED may be associated with an elevated level of ROS in penile tissue.

T cell-derived leptin contributes to increased frequency of T helper type 17 cells in female patients with Hashimoto's thyroiditis

Leptin modulates T cell function and plays an important role in autoimmune diseases. Our study aimed to explore the role of leptin and T helper type 17 (Th17) cells in Hashimoto's thyroiditis patients. Twenty-seven patients with Hashimoto's thyroiditis (HT) and 20 healthy controls were enrolled into the current study. A modest increase of plasma leptin in HT patients and the CD4(+) T cell-derived leptin from HT patients was stronger than that from healthy controls. In HT patients, there are no statistically significant correlations between plasma leptin concentrations and the percentage of Th17 cells or the level of retinoic acid-related orphan receptor γt (RORγt), but strong positive correlations were observed between CD4(+) T cell-derived leptin and the percentage of Th17 cells or the level of RORγt mRNA, and additionally significantly up-regulated leptin, interleukin (IL)17 and RORγt mRNA levels in the thyroid tissue. Furthermore, neutralization of leptin decreases the frequency of Th17 cells in vitro. Current study has revealed an increased leptin involvment in Hashimoto's thyroiditis associated with an increased number of Th17 cells.

Dual modes of antitumor action of an amphiphilic peptide A(9)K

Following our recent report of attractive antibacterial properties of a designed amphiphilic peptide, A(9)K, we have investigated its antitumor activities by examining the modes of its action against different mammalian cell types. The peptide strongly inhibited the growth of cancerous HeLa cells and human promyelocytic leukemia HL60 cells whilst remaining benign to the host cells, including Cos 7 cells, mouse fibroblast NIH3T3 cells and human red blood cells. Images from SEM and fluorescence microscopy showed that A(9)K penetrated HeLa cell membranes and disrupted membrane structures, a feature broadly similar to that observed from its bactericidal actions. Further interactions of A(9)K with inner cellular membranes caused mitochondrial dysfunction associated with the F-actin reorganization and the decreased transcription of bcl-2 and c-myc genes, resulting in HeLa cell apoptosis in a mitochondria-induced apoptosis pathway. Thus A(9)K has high selectivity against cancerous cells and kills them by dual modes of action: membrane disruption and cell apoptosis. In addition, the peptide does not induce non-specific immunological effects and is not degraded by proteases. These features are crucial for developing their applications in future research.

Replication of endometriosis-associated single-nucleotide polymorphisms from genome-wide association studies in a Caucasian population

STUDY QUESTION

Is it possible to replicate the previously identified genetic association of four single-nucleotide polymorphisms (SNPs), rs12700667, rs7798431, rs1250248 and rs7521902, with endometriosis in a Caucasian population?

SUMMARY ANSWER

A borderline association was observed for rs1250248 and endometriosis (P = 0.049). However, we could not replicate the other previously identified endometriosis-associated SNPs (rs12700667, rs7798431 and rs7521902) in the same population.

WHAT IS KNOWN ALREADY

Endometriosis is considered a complex disease, influenced by several genetic and environmental factors, as well as interactions between them. Previous studies have found genetic associations with endometriosis for SNPs at the 7p15 and 2q35 loci in a Caucasian population.

STUDY DESIGN, SIZE, DURATION

Allele frequencies of SNPs were investigated in patients with endometriosis and controls.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Blood samples and peritoneal biopsies were taken from a Caucasian female population consisting of 1129 patients with endometriosis and 831 controls. DNA was extracted for genotyping. The study was performed at a University hospital and research laboratories.

MAIN RESULTS AND THE ROLE OF CHANCE

A weak association with endometriosis (all stages) was observed for rs1250248 (P = 0.049). No significant associations were observed for the SNPs rs12700667, rs7798431 and rs7521902. A non-significant trend towards the association of rs1250248 with moderate/severe endometriosis was observed (odds ratio 1.18, 95% confidence interval 0.97-1.44).

LIMITATIONS, REASONS FOR CAUTION

The inability to confirm all previous findings may result from differences between populations and type II errors.

WIDER IMPLICATIONS OF THE FINDINGS

Our result demonstrates the difficulty of identifying common genetic variants in complex diseases.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by grants from the Karolinska Institutet and Stockholm City County/Karolinska Institutet (ALF), Stockholm, Sweden, Swedish Medical Research Council (K2007-54X-14212-06-3, K2010-54X-14212-09-3), Stockholm, Sweden, Leuven University Research Council (Onderzoeksraad KU Leuven), the Leuven University Hospitals Clinical Research Foundation (Klinisch onderzoeksfonds) and by the National Scientific Foundation (Fonds voor Wetenschappelijk Onderzoek, FWO). The authors have no conflict of interest.

Observation of two new N* resonances in the decay ψ(3686)→ppπ0

Based on 106×10(6)ψ(3686) events collected with the BESIII detector at the BEPCII facility, a partial wave analysis of ψ(3686)→ppπ0 is performed. The branching fraction of this channel has been determined to be B(ψ(3686)→ppπ0)=(1.65±0.03±0.15)×10(-4). In this decay, 7 N* intermediate resonances are observed. Among these, two new resonances, N(2300) and N(2570) are significant, one 1/2+ resonance with a mass of 2300(-30-0)(+40+109)  MeV/c2 and width of 340(-30-58)(+30+110)  MeV/c2, and one 5/2- resonance with a mass of 2570(-10-10)(+19+34)  MeV/c2 and width of 250(-24-21)(+14+69)  MeV/c2. For the remaining 5 N* intermediate resonances [N(1440), N(1520), N(1535), N(1650) and N(1720)], the analysis yields mass and width values that are consistent with those from established resonances.

Association of Gln223Arg polymorphism of the leptin receptor with hypertensive left ventricular hypertrophy

This study was aimed to determine whether the leptin receptor Gln223Arg polymorphism has an effect on plasma leptin levels and left ventricular hypertrophy in hypertension. The genotypes and allelic frequencies of the leptin receptor Gln223Arg were examined using the polymerase chain reaction and restriction fragment length polymorphism in 190 hypertensive patients and 88 healthy controls. Logarithmic (log) transformation of the plasma leptin level was carried out before performing comparison and regression analysis. The values of log(plasma leptin levels) in the hypertensive patients were higher than those of controls and they were higher in hypertensive patients with left ventricular hypertrophy than those without it (P < 0.05). The genotype (AA, AG, and GG) distribution of Gln223Arg polymorphism was 6.8, 33.8, and 59.4% in hypertensive patients with left ventricular hypertrophy, 4.3, 27.6, and 68.1% in patients without left ventricular hypertrophy, and 2.3, 26.1, and 71.6% in the controls, respectively. A significant difference was found among these three groups (P < 0.05). The frequency of allele A was higher in patients with left ventricular hypertrophy than in patients without it (23.6 vs. 18.1%; P < 0.05). Log(plasma leptin levels) and left ventricular mass index were higher in patients with the AA genotype than those with the AG or GG genotype in hypertensive patients (P < 0.05). In multivariate regression analysis, the AA genotype as an independent predictor had statistically significant effects on the left ventricular mass index. Our results suggest that the Gln223Arg polymorphism of the leptin receptor is significantly associated with plasma leptin levels and left ventricular hypertrophy in hypertension.

Protection against L-NAME-induced reduction in cardiac output persists even after cessation of angiotensin-converting enzyme inhibitor treatment

AIM

We have demonstrated that short-term angiotensin-converting enzyme (ACE) inhibition in adult spontaneously hypertensive rats produces cardiac changes that persist following cessation of treatment that result in a reduced inflammatory, proliferative and fibrotic response to the nitric oxide synthase inhibitor N(ω) -Nitro-l-arginine methyl ester (L-NAME). The present study examines whether prior ACE inhibition with enalapril also protects against L-NAME-induced cardiac dysfunction.

METHODS

Rats were treated with enalapril (Enal + L) or tap water (Con, Con + L) for 2 weeks followed by a 2-week washout period. At this point, Con + L and Enal + L rats were treated with L-NAME for 10 days. Hearts were perfused in the working mode, mean arterial pressure (MAP) was assessed via radiotelemetry, and myocardial injury was evaluated in hematoxylin and eosin-stained sections.

RESULTS

L-NAME increased MAP by a similar magnitude in Con + L and Enal + L. L-NAME-induced statistically significant decreases in flow-mediated functional parameters in Con + L rats including cardiac output, stroke volume and coronary flow. This was prevented by prior enalapril treatment. Prior enalapril did not prevent L-NAME-induced myocardial injury, but may have lessened the degree of it. Regardless of treatment, changes in cardiac function did not correlate with myocardial injury.

CONCLUSION

Despite equivalent impact on MAP and incidence of myocardial infarction, prior enalapril treatment resulted in the preservation of cardiac function following L-NAME. Understanding the mechanisms by which transient ACE inhibition protects against reductions in cardiac function in the absence of ongoing treatment may reveal novel targets for heart failure treatment.

Short peptide-directed synthesis of one-dimensional platinum nanostructures with controllable morphologies

Although one dimensional (1D) Pt nanostructures with well-defined sizes and shapes have fascinating physiochemical properties, their preparation remains a great challenge. Here we report an easy and novel synthesis of 1D Pt nanostructures with controllable morphologies, through the combination of designer self-assembling I3K and phage-displayed P7A peptides. The nanofibrils formed via I3K self-assembly acted as template. Pt precursors ((PtCl4)(2-) and (PtCl6)(2-)) were immobilized by electrostatic interaction on the positively charged template surface and subsequent reduction led to the formation of 1D Pt nanostructures. P7A was applied to tune the continuity of the Pt nanostructures. Here, the electrostatic repulsion between the deprotonated C-terminal carboxyl groups of P7A molecules was demonstrated to play a key role. We finally showed that continuous and ordered 1D Pt morphology had a significantly improved electrochemical performance for the hydrogen and methanol electro-oxidation in comparison with either 1D discrete Pt nanoparticle assemblies or isolated Pt nanoparticles.

HMGB1 promotes the differentiation of Th17 via up-regulating TLR2 and IL-23 of CD14+ monocytes from patients with rheumatoid arthritis

High-mobility group box 1 (HMGB1) is a non-histone nuclear protein that is released extracellulary and has been implicated in autoimmune disease. Toll-like receptor 2 (TLR2) signalling is thought to be essential for the inflammatory response and for immune disorders. In recent studies, enhanced HMGB1 and TLR2 expressions have been found in rheumatoid arthritis (RA), respectively. The aim of this study is to explore whether HMGB1 stimulation can up-regulate the expression of TLR2 on CD14(+) monocytes from patients with RA and to clarify the subsequent events involving Th17 cells and Th17 cell-associated cytokine changes. Our results showed that the frequency of CD14(+) cells in peripheral blood mononuclear cell (PBMC) was obviously increased, and enhanced expression of TLR2 on CD14(+) monocytes was also found in patients with RA, compared with healthy controls with statistical significance (P < 0.001). In addition, the levels of IL-17, IL-23 and IL-6 in supernatants from cultured monocytes from patients and in patient's plasma were increased, and NF-κB, the downstream target of TLR2, also showed a marked elevation after monocytes were stimulated by HMGB1. This implies that the enhanced TLR2 pathway and Th17 cell polarization may be due to HMGB1 stimulation in rheumatoid arthritis.