Release of Bisphenol A from Milled and 3D-Printed Dental Polycarbonate Materials

Polycarbonates are polymers of bisphenol A (BPA), a well-known endocrine disruptor. This study evaluated the release of BPA from polycarbonate crowns that were (1) milled from Temp Premium Flexible (ZPF, Zirkonzahn, Italy) or Tizian Blank Polycarbonate (TBP, Schütz Dental, Germany), or (2) 3D-printed (Makrolon 2805, Covestro, Germany). Commercial prefabricated polycarbonate crowns (3M, USA) and milled poly(methyl methacrylate) (PMMA) crowns (Temp Basic, Zirkonzahn, Italy) were included for comparison. The crowns were stored at 37 °C in artificial saliva (AS) or methanol, which represented the worst-case scenario of BPA release. Extracts were collected after 1 day, 1 week, 1 month and 3 months. BPA concentrations were measured using liquid chromatography-tandem mass spectrometry. The amounts of released BPA were expressed in micrograms per gram of material (μg/g). After 1 day, the highest amounts of BPA were measured from milled polycarbonates, TBP (methanol: 32.2 ± 3.8 μg/g, AS: 7.1 ± 0.9 μg/g) and ZPF (methanol 22.8 ± 7.7 μg/g, AS: 0.3 ± 0.03 μg/g), followed by 3D-printed crowns (methanol: 11.1 ± 2.3 μg/g, AS: 0.1 ± 0.1 μg/g) and prefabricated crowns (methanol: 8.0 ± 1.6 μg/g, AS: 0.07 ± 0.02 μg/g). Between 1 week and 3 months, the average daily release of BPA in methanol and AS decreased below 2 μg/g and 0.6 μg/g, respectively. No BPA was released from PMMA in AS, and the cumulative amount released in methanol was 0.2 ± 0.06 μg/g. In conclusion, polycarbonates could be a relevant source of BPA, but the current tolerable daily intake of BPA (4 μg/kg body weight) should not be exceeded.     

Linking soluble vascular adhesion molecule-1 level to calcific aortic stenosis in patients with coronary artery disease

BACKGROUND:

Calcific aortic stenosis (AS) is an atherosclerosis-related process and the most common cause of valve disease requiring surgery.

OBJECTIVE:

To assess the association of inflammatory markers with AS in advanced atherosclerosis.

METHODS:

Consecutive patients with coronary artery disease (CAD) associated with AS were prospectively identified (mean transvalvular aortic gradient of 30 mmHg or greater). Subjects with aortic sclerosis (mean transvalvular aortic gradient of 10 mmHg or less) served as controls. All patients underwent clinical evaluation, echocardiography and coronary angiography.

RESULTS:

One hundred twenty-two patients with AS (85 men) and 101 with aortic sclerosis (76 men) of similar CAD severity were enrolled. The AS patients were older (mean [± SD] 71±7 years versus 66±7 years; P<0.001), had higher soluble vascular adhesion molecule-1 (s-VCAM-1) levels (1533±650 μg/L versus 1157±507 μg/L; P<0.001), but lower soluble intercellular adhesion molecule-1 (s-ICAM-1) (254±81 μg/L versus 293±84 μg/L; P<0.01) and soluble E-selectin (53±28 μg/L versus 62±29 μg/L; P<0.05) levels. The two groups did not differ with respect to C-reactive protein level (3±2.9 mg/L versus 3.4±2.6 mg/L; P not significant). Higher s-VCAM-1 (OR 1.09, 95% CI 1.04 to 1.14; P<0.001) and lower s-ICAM-1 (OR 0.82, 95% CI 0.72 to 0.94; P<0.001) levels were associated with AS after adjustment for age.

CONCLUSION:

Increased s-VCAM-1 levels were associated with calcific AS in patients with significant CAD.     

Uptake of bacterial lipopolysaccharide and expression of tumor necrosis factor-α-mRNA in isolated rat intrahepatic bile duct epithelial cells

AIM: To study the uptake of bacterial lipopolysaccharides (LPS) and expression of tumor necrosis factor α-mRNA (TNF-α-mRNA) with cultured rat intrahepatic bile duct epithelial cells.METHODS: By using fluorescent, immunohistochemical and in situ hybridization techniques, the uptake of Escherichia coli LPS and expression of TNF-α-mRNA with isolated rat intrahepatic bile duct epithelial cells were observed with confocal laser scanning microscopy.RESULTS: Positive reactions to LPS were found in the cytoplasm of isolated intrahepatic bile duct epithelial cells after incubation with LPS for 15 min and the FITC fluorescent intensity against LPS was significantly higher than that of the controls (121.45 μFI/μm² ± 15.62 μFI/μm² vs 32.12 μFI/μm² ± 9.64 μFI/μm², P < 0.01). After incubation with LPS for 3 h, fluorescein isocyanate (FITC) fluorescent intensities of the expression of TNF-α-mRNA with fluorescent in situ hybridization in the cytoplasm and nuclei of the cultured bile duct epithelial cells were significantly higher than those of the controls (189.15 μFI/μm² ± 21.33 μFI/μm² vs 10.00 μFI/μm² ± 8.99 μFI/μm², 64.85 μFI/μm² ± 14.99 μFI/μm² vs 21.20 μFI/μm² ± 2.04 μFI/μm², respectively (P < 0.01)). The increase of FITC fluorescent intensity of TNF-α-mRNA expression in the cytoplasm peaked at 6 h after incubation (221.38 μFI/μm² ± 22.99 μFI/μm²). At various time points after incubation with LPS, the increase of fluorescent intensities of TNF-α-mRNA in the cytoplasm were much higher than those in the nuclei (P < 0.01).CONCLUSION: LPS can act on and enter into isolated intrahepatic bile duct epithelial cells and stimulate the expression of TNF-α-mRNA.     

Axl glycosylation mediates tumor cell proliferation, invasion and lymphatic metastasis in murine hepatocellular carcinoma

AIM: To investigate the effects of Axl deglycosylation on tumor lymphatic metastases in mouse hepatocellular carcinoma cell lines. METHODS: Western blotting was used to analyze the expression profile of Axl glycoprotein in mouse hepa-tocellular carcinoma cell line Hca-F treated with tunicamycin and PNGase F 3-(4,5)-dimethylthiazol(-zyl)-3,5- diphenyltetrazolium bromide (MTT) assay, extracellular matrix (ECM) invasion assay (in vitro ) and tumor metastasis assay (in vivo ) were utilized to evaluate the effect of Axl deglycosylation on the Hca-F cell proliferation, invasion and lymphatic metastasis. RESULTS: Tunicamycin and PNGase F treatment markedly inhibited Axl glycoprotein synthesis and expression, proliferation, invasion, and lymphatic metastasis both in vitro and in vivo . In the MTT assay, proliferation was apparent in untreated Hca-F cells compared with treated Hca-F cells. In the ECM invasion assay (in vitro ), treated cells passed through the ECMatrix gel in significantly smaller numbers than untreated cells (tunicamycin 5 μg/mL: 68 ± 8 vs 80 ± 9, P=0.0222; 10 μg/mL: 50 ± 6vs 80 ± 9,P=0.0003; 20 μg/mL: 41 ± 4 vs 80 ± 9, P=0.0001); (PNGase F 8 h: 66 ± 7 vs 82 ± 8, P=0.0098; 16 h: 49 ± 4 vs 82 ± 8, P=0.0001; 24 h: 34 ± 3 vs 82 ± 8, P=0.0001). In the tumor metastasis assay (in vivo ), average lymph node weights of the untreated Hca-F group compared with treated Hca-F groups (tunicamycin 5 μg/mL: 0.84 ± 0.21 g vs 0.72 ± 0.19 g, P=0.3237; 10 μg/mL: 0.84 ± 0.21 g vs 0.54 ± 0.11 g, P=0.0113; 20 μg/mL: 0.84 ± 0.21 g vs 0.42 ± 0.06 g, P=0.0008); (PNGase F 8 h: 0.79 ± 0.15 g vs 0.63 ± 0.13 g, P=0.0766; 16 h: 0.79 ± 0.15 g vs 0.49 ± 0.10 g, P=0.0022; 24 h: 0.79 ± 0.15 g vs 0.39 ± 0.05 g, P=0.0001). Also, average lymph node volumes of the untreated Hca-F group compared with treated Hca-F groups (tunicamycin 5 μg/mL: 815 ± 61 mm 3 vs 680 ± 59 mm 3 , P=0.0613; 10 μg/mL: 815 ± 61 mm 3 vs 580 ± 29 mm 3 , P=0.0001; 20 μg/mL: 815 ± 61 mm 3 vs 395 ± 12 mm 3 , P=0.0001); (PNGase F 8 h: 670 ± 56 mm 3 vs 581 ± 48 mm 3 , P=0.0532; 16 h: 670 ± 56 mm 3 vs 412 ± 22 mm 3 , P=0.0001; 24 h: 670 ± 56 mm 3 vs 323 ± 11 mm 3 , P=0.0001). CONCLUSION: Alteration of Axl glycosylation can at-tenuate neoplastic lymphatic metastasis. Axl N-glycans may be a universal target for chemotherapy.     

Effect of gingerol on colonic motility via inhibition of calcium channel currents in rats

AIM: To investigate the effect of gingerol on colonic motility and the action of L-type calcium channel currents in this process.METHODS: The distal colon was cut along the mesenteric border and cleaned with Ca²⁺-free physiological saline solution. Muscle strips were removed and placed in Ca²⁺-free physiological saline solution, which was oxygenated continuously. Longitudinal smooth muscle samples were prepared by cutting along the muscle strips and were then placed in a chamber. Mechanical contractile activities of isolated colonic segments in rats were recorded by a 4-channel physiograph. Colon smooth muscle cells were dissociated by enzymatic digestion. L-type calcium currents were recorded using the conventional whole-cell patch-clamp technique.RESULTS: Gingerol inhibited the spontaneous contraction of colonic longitudinal smooth muscle in a dose-dependent manner with inhibition percentages of 13.3% ± 4.1%, 43.4% ± 3.9%, 78.2% ± 3.6% and 80.5% ± 4.5% at 25 μmol/L, 50 μmol/L, 75 μmol/L and 100 μmol/L, respectively (P < 0.01). Nifedipine, an L-type calcium channel blocker, diminished the inhibition of colonic motility by gingerol. Gingerol inhibited L-type calcium channel currents in colonic longitudinal myocytes of rats. At a 75 μmol/L concentration of gingerol, the percentage of gingerol-induced inhibition was diminished by nifedipine from 77.1% ± 4.2% to 42.6% ± 3.6% (P < 0.01). Gingerol suppressed I_Ba in a dose-dependent manner, and the inhibition rates were 22.7% ± 2.38%, 35.77% ± 3.14%, 49.78% ± 3.48% and 53.78% ± 4.16% of control at 0 mV, respectively, at concentrations of 25 μmol/L, 50 μmol/L, 75 μmol/L and 100 μmol/L (P < 0.01). The steady-state activation curve was shifted to the right by treatment with gingerol. The value of half activation was -14.23 ± 1.12 mV in the control group and -10.56 ± 1.04 mV in the 75 μmol/L group (P < 0.05) with slope factors, Ks, of 7.16 ± 0.84 and 7.02 ± 0.93 (P < 0.05) in the control and 75 μmol/L groups, respectively. However, the steady-state inactivation curve was not changed, with a half-inactivation voltage, 0.5 V, of -27.43 ± 1.26 mV in the control group and -26.56 ± 1.53 mV in the 75 μmol/L gingerol group (P > 0.05), and a slope factor, K, of 13.24 ± 1.62 in the control group and 13.45 ± 1.68 (P > 0.05) in the 75 μmol/L gingerol group.CONCLUSION: Gingerol inhibits colonic motility by preventing Ca²⁺ influx through L-type calcium channels.     

Prednisolone inhibits phagocytosis by polymorphonuclear leucocytes via steroid receptor mediated events

Prednisolone, at concentrations between 2·78 × 10⁻⁶ M (1 μg/ml) and 1·39 × 10⁻⁸ M (5 × 10⁻³ μg/ml) exerts an inhibitory effect on the phagocytosis of latex particles by normal human polymorphonuclear leucocytes in vitro as assessed by electron microscopical analysis. This inhibition appears to be receptor-mediated, as it is dependent upon RNA and protein synthesis and is glucocorticoid specific.     

Cement-Based Thermoelectric Device for Protection of Carbon Steel in Alkaline Chloride Solution

The thermoelectric cement-based materials can convert heat into electricity; this makes them promising candidates for impressed current cathodic protection of carbon steel. However, attempts to use the thermoelectric cement-based materials for energy conversion usually results in low conversion efficiency, because of the low electrical conductivity and Seebeck coefficient. Herein, we deposited polyaniline on the surface of MnO₂ and fabricated a cement-based thermoelectric device with added PANI/MnO₂ composite for the protection of carbon steel in alkaline chloride solution. The nanorod structure (70~80 nm in diameter) and evenly dispersed conductive PANI provide the PANI/MnO₂ composite with good electrical conductivity (1.9 ± 0.03 S/cm) and Seebeck coefficient (−7.71 × 10³ ± 50 μV/K) and, thereby, increase the Seebeck coefficient of cement-based materials to −2.02 × 10³ ± 40 μV/K and the electrical conductivity of cement-based materials to 0.015 ± 0.0003 S/cm. Based on this, the corrosion of the carbon steel was delayed after cathodic protection, which was demonstrated by the electrochemical experiment results, such as the increased resistance of the carbon steel surface from 5.16 × 10² Ω·cm² to 5.14 × 10⁴ Ω·cm², increased charge transfer resistance from 11.4 kΩ·cm² to 1.98 × 10⁶ kΩ·cm², and the decreased corrosion current density from 1.67 μA/cm² to 0.32 μA/cm², underlining the role of anti-corrosion of the PANI/MnO₂ composite in the cathodic protection system.     

Lateral diffusion of phospholipids in the plasma membrane of soybean protoplasts: Evidence for membrane lipid domains

Fluorescent lipid and phospholipid probes were incorporated at 4°C into soybean protoplasts prepared from cultured soybean (SB-1) cells. Fluorescence microscopy showed that the plasma membrane as well as the nucleus were labeled. Fluorescence redistribution after photobleaching (FRAP) analysis was performed on these cells at 18°C to monitor the lateral mobility of the incorporated probes. After labeling at low concentrations (40 μg/ml) of phosphatidyl-N-(4-nitrobenzo-2-oxa-1,3-diazolyl)ethanolamine (NBD-PtdEtn), a single mobile component was observed with a diffusion coefficient (D) of ≈3 × 10^-9 cm²/sec. After labeling at higher probe concentrations (≥100 μg/ml), two diffusing species were observed, with diffusion coefficients of ≈3 × 10^-9 cm²/sec (“fast”) and ≈5 × 10^-10 cm²/sec (“slow”). Similar results were observed with fluorescent derivatives of phosphatidylcholine and fatty acids. In contrast to these results, parallel analysis of 3T3 fibroblasts, using the same probes and conditions, yielded only a single diffusion component. These results suggest that the soybean plasma membrane may contain two distinct lipid domains in terms of lipid mobility. Consistent with this idea, experiments with soybean protoplasts yielded a single diffusion component under the following conditions: (i) labeling with NBD-PtdEtn (100 μg/ml), FRAP analysis at 37°C (D = 1.1 × 10^-8 cm²/sec); (ii) labeling with NBD-PtdEtn (100 μg/ml), FRAP analysis at 18°C in the presence of 2 mM EGTA (D = 4.2 × 10^-9 cm²/sec); (iii) labeling with 5-(N-dodecanoyl)aminofluorescein (a short-chain lipid probe), FRAP analysis at 18°C or 37°C (D = 2.5 × 10^-8 cm²/sec). These results suggest that the plasma membrane of soybean cells may contain stable immiscible domains of fluid and gel-like lipids.     

A study of Chitosan and c‐di‐GMP as mucosal adjuvants for intranasal influenza H5N1 vaccine

Please cite this paper as: Svindland et al. (2012) A study of Chitosan and c‐di‐GMP as mucosal adjuvants for intranasal influenza H5N1 vaccine. Influenza and Other Respiratory Viruses 10.1111/irv.12056000(000), 000–000. Background  Highly pathogenic avian influenza A/H5N1 virus remains a potential pandemic threat, and it is essential to continue vaccine development against this subtype. A local mucosal immune response in the upper respiratory tract may stop influenza transmission. It is therefore important to develop effective intranasal pandemic influenza vaccines that induce mucosal immunity at the site of viral entry. Objectives  We evaluated the humoral and cellular immune responses of two promising mucosal adjuvants (Chitosan and c‐di‐GMP) for intranasal influenza H5N1 vaccine in a murine model. Furthermore, we evaluated the concept of co‐adjuvanting an experimental adjuvant (c‐di‐GMP) with chitosan. Methods  BALB/c mice were intranasally immunised with two doses of subunit NIBRG‐14 (H5N1) vaccine (7·5, 1·5 or 0·3 μg haemagglutinin (HA) adjuvanted with chitosan (CSN), c‐di‐GMP or both adjuvants. Results  All adjuvant formulations improved the serum and local antibody responses, with the highest responses observed in the 7·5 μg HA CSN and c‐di‐GMP‐adjuvanted groups. The c‐di‐GMP provided dose sparing with protective single radial haemolysis (SRH), and haemagglutination inhibition (HI) antibody responses found in the 0·3 μg HA group. CSN elicited a Th2 response, whereas c‐di‐GMP induced higher frequencies of virus‐specific CD4⁺ T cells producing one or more Th1 cytokines (IFN‐γ⁺, IL‐2⁺, TNF‐α⁺). A combination of the two adjuvants demonstrated effectiveness at 7·5 μg HA and triggered a more balanced Th cytokine profile. Conclusion  These data show that combining adjuvants can modulate the Th response and in combination with ongoing studies of adjuvanted intranasal vaccines will dictate the way forward for optimal mucosal influenza vaccines.     

Cone parameters in different vision levels from the adaptive optics imaging

To investigate the relationship between visual resolution and cone parameters in eyes with different levels of best corrected visual acuity (BCVA).Seventeen eyes of 10 volunteers with BCVA of 20/12.5 or better (group 1) and 16 eyes of 10 volunteers with BCVA of 20/16 (group 2) were investigated in the study. Images of the cone photoreceptors at 1.5^° from the fovea were obtained using an adaptive optics (AO) retinal camera. The BCVA was obtained following a subjective refraction using a standardized logMAR visual acuity chart.The mean cone density (29,570.96 ± 2489.94 cells/mm²) at 1.5° from the fovea in group 1 (BCVA ≥ 20/12.5, n = 17) was significantly greater (P < .001) than that (22,963.59 ± 2987.92 cells/mm²) in group 2 (BCVA = 20/16, n = 16). The cone spacing at 1.5^° from the fovea in group 1 was 6.45 ± 0.28 μm (mean ± SD), which was significantly smaller (P < .001) than 7.36 ± 0.50 μm (mean ± SD) in group 2. In the stepwise regression analysis, greater angular cone density (odds ratio [OR], 4.48; P = .005) and smaller angular cone spacing (OR, 0.60; P = .007) at 1.5^° from the fovea were significantly associated with the better BCVA.The greater cone density and smaller cone spacing at the parafovea were found in eyes with BCVA of 20/12.5 or better, as compared to that in eyes with BCVA of 20/16. Knowledge of cone distribution for different BCVA levels may be beneficial for different clinical conditions.     

Effect of Zinc Supplementation on Serum Homocysteine in Type 2 Diabetic Patients with Microalbuminuria

OBJECTIVES: Elevated homocysteine levels are considered to be an independent risk factor for cardiovascular complications in diabetic patients. The aim of this study was to find out if zinc supplementation improves homocysteine levels, which may exert vascular-protective effects in type 2 diabetes subjects with microalbuminuria. METHODS: In a randomized, double-blind, controlled, crossover study, 50 type 2 diabetic patients with microalbuminuria were subdivided into two groups and supplemented with 30 mg/d of zinc (group 1) or placebo (group 2) for three months with a four-week wash out period. Serum creatinine, vitamin B₁₂, folate, fasting plasma glucose, HbA1c, lipid profiles, zinc, homocysteine levels and random urine albumin were measured before and after the first and second phase of the study in all participants. RESULTS: Mean serum zinc was significantly increased after zinc supplementation (from 76 ± 16 μg/dl to 93 ± 20 µg/dl; p < 0.05), while there was no change in the placebo group (75 ± 16 µg/dl to 75 ± 15 µg/dl). With zinc supplementation, homocysteine levels reduced significantly (from 13.71 ± 3.84 μmol/l to 11.79 ± 3.06 μmol/l; p < 0.05), which did not occur on placebo (from 12.59 ± 2.13 μmol/l to 13.36 ± 2.03 μmol/l). Simple regression was used to show a positive correlation between urine albumin excretion and serum homocysteine (r = 0.37, p = 0.023). Vitamin B₁₂ and folate levels increased significantly in patients who received zinc in comparison to those who received placebo. A negative correlation was observed between homocysteine and vitamin B₁₂ concentration (r = -0.36, p = 0.025). CONCLUSION: Zinc supplementation reduced serum homocysteine and increased vitamin B₁₂ and folate concentrations in type 2 diabetic patients with microalbuminuria.     

Beneficial effects of adenosine triphosphate-sensitive K+ channel opener on liver ischemia/reperfusion injury

AIM: To investigate the effect of diazoxide administration on liver ischemia/reperfusion injury.METHODS: Wistar male rats underwent partial liver ischemia performed by clamping the pedicle from the medium and left anterior lateral segments for 1 h under mechanical ventilation. They were divided into 3 groups: Control Group, rats submitted to liver manipulation, Saline Group, rats received saline, and Diazoxide Group, rats received intravenous injection diazoxide (3.5 mg/kg) 15 min before liver reperfusion. 4 h and 24 h after reperfusion, blood was collected for determination of aspartate transaminase (AST), alanine transaminase (ALT), tumor necrosis factor (TNF-α), interleukin-6 (IL-6), interleukin-10 (IL-10), nitrite/nitrate, creatinine and tumor growth factor-β1 (TGF-β1). Liver tissues were assembled for mitochondrial oxidation and phosphorylation, malondialdehyde (MDA) content, and histologic analysis. Pulmonary vascular permeability and myeloperoxidase (MPO) were also determined.RESULTS: Four hours after reperfusion the diazoxide group presented with significant reduction of AST (2009 ± 257 U/L vs 3523 ± 424 U/L, P = 0.005); ALT (1794 ± 295 U/L vs 3316 ± 413 U/L, P = 0.005); TNF-α (17 ± 9 pg/mL vs 152 ± 43 pg/mL, P = 0.013; IL-6 (62 ± 18 pg/mL vs 281 ± 92 pg/mL); IL-10 (40 ± 9 pg/mL vs 78 ± 10 pg/mL P = 0.03), and nitrite/nitrate (3.8 ± 0.9 μmol/L vs 10.2 ± 2.4 μmol/L, P = 0.025) when compared to the saline group. A significant reduction in liver mitochondrial dysfunction was observed in the diazoxide group compared to the saline group (P < 0.05). No differences in liver MDA content, serum creatinine, pulmonary vascular permeability and MPO activity were observed between groups. Twenty four hours after reperfusion the diazoxide group showed a reduction of AST (495 ± 78 U/L vs 978 ± 192 U/L, P = 0.032); ALT (335 ± 59 U/L vs 742 ± 182 U/L, P = 0.048), and TGF-β1 (11 ± 1 ng/mL vs 17 ± 0.5 ng/mL, P = 0.004) serum levels when compared to the saline group. The control group did not present alterations when compared to the diazoxide and saline groups.CONCLUSION: Diazoxide maintains liver mitochondrial function, increases liver tolerance to ischemia/reperfusion injury, and reduces the systemic inflammatory response. These effects require further evaluation for using in a clinical setting.     

Synthesis,Crystal Structure and Luminescent Property of Cd (II) Complex with N-Benzenesulphonyl-L-leucine

A new trinuclear Cd (II) complex [Cd₃(L)₆(2,2-bipyridine)₃] [L = N-phenylsulfonyl-L-leucinato] has been synthesized and characterized by elemental analysis, IR and X-ray single crystal diffraction analysis. The results show that the complex belongs to the orthorhombic, space group P2₁2₁2₁ with a = 16.877(3) Å, b = 22.875(5) Å, c = 29.495(6) Å, α = β = γ = 90°, V = 11387(4) ų, Z = 4, D_c= 1.416 μg·m⁻³, μ = 0.737 mm⁻¹, F (000) = 4992, and final R₁ = 0.0390, ωR₂ = 0.0989. The complex comprises two seven-coordinated Cd (II) atoms, with a N₂O₅ distorted pengonal bipyramidal coordination environment and a six-coordinated Cd (II) atom, with a N₂O₄ distorted octahedral coordination environment. The molecules form one dimensional chain structure by the interaction of bridged carboxylato groups, hydrogen bonds and π-π interaction of 2,2-bipyridine. The luminescent properties of the Cd (II) complex and N-Benzenesulphonyl-L-leucine in solid and in CH₃OH solution also have been investigated.     

Effects of Intercooling Intensity on Temperature Field and Microstructure of Large-Scale 2219 Al Alloy Billet Prepared by Internal Electromagnetic Stirring Casting

Internal electromagnetic stirring is an advanced melt treatment method, which can be used in direct chill casting to prepare large-scale Al alloy billets. Intercooling intensity is a primary parameter of internal electromagnetic stirring; its effects on temperature fields and microstructures have been investigated via numerical simulations and industrial experiments, respectively. The simulated results show an increase in the intercooling affected area and a decrease in sump depth with an increase in the intercooling heat transfer coefficient. The heat transfer coefficient should not exceed 500 W/(m² °C) because the solid fraction of the intercooling end bottom may exceed 50%. The experiment’s results demonstrate that the average grain sizes in the edge, 1/2 radius, and center are 151 ± 13 μm, 159 ± 14 μm, and 149 ± 16 μm, respectively, under a liquid nitrogen flow rate of 160 L/min, which is much finer than that of 80 L/min and more homogeneous than that of 240 L/min. Furthermore, an experimental liquid nitrogen flow rate of 80 L/min, 160 L/min, and 240 L/min approximately correspond to the simulated heat transfer coefficient of 200 W/(m² °C), 300 W/(m² °C), and 400 W/(m² °C), respectively.     

Bioactive Bacterial Nanocellulose Membranes Enriched with Eucalyptus globulus Labill. Leaves Aqueous Extract for Anti-Aging Skin Care Applications

Bacterial nanocellulose (BNC) membranes, with remarkable physical and mechanical properties, emerged as a versatile biopolymeric carrier of bioactive compounds for skin care applications. In this study, BNC membranes were loaded with glycerol (as plasticizer and humectant agent) and different doses (1–3 μg cm⁻²) of an aqueous extract obtained from the hydro-distillation of Eucalyptus globulus Labill. leaves (HDE), for application as sheet facial masks. All membranes are resistant and highly malleable at dry and wet states, with similar or even better mechanical properties than those of a commercial BNC mask. Moreover, the HDE was found to confer a dose-dependent antioxidant activity to pure BNC. Additionally, upon 3 months of storage at 22–25 °C and 52% relative humidity (RH) or at 40 °C and 75% RH, it was confirmed that the antioxidant activity and the macroscopic aspect of the membrane with 2 μg cm⁻² of HDE were maintained. Membranes were also shown to be non-cytotoxic towards HaCaT and NIH/3T3 cells, and the membrane with 2 μg cm⁻² of HDE caused a significant reduction in the senescence-associated β-galactosidase activity in NIH/3T3 cells. These findings suggest the suitability and potential of the obtained membranes as bioactive facial masks for anti-aging applications.     

The Microvasculature in Chronic Kidney Disease

Summary

Background and objectives

Individuals with chronic kidney disease (CKD) stages 3 to 5 have an increased risk of cardiac and other vascular disease. Here we examined the association of CKD 3 to 5 with small vessel caliber.

Design, setting, participants, & measurements

This was a cross-sectional observational study of 126 patients with CKD stages 3 to 5 (estimated GFR [eGFR] <60 ml/min per 1.73 m²) and 126 age- and gender-matched hospital patients with CKD 1 or 2. Retinal vessel diameters were measured from digital fundus images by a trained grader using a computer-assisted method and summarized as the central retinal artery equivalent (CRAE) and central retinal vein equivalent (CRVE).

Results

Patients with CKD 3 to 5 had a smaller mean CRAE and CRVE than hospital controls (139.4 ± 17.8 μm versus 148.5 ± 16.0 μm, P < 0.001; and 205.0 ± 30.7 μm versus 217.4 ± 25.8 μm, respectively; P = 0.001). CRAE and CRVE decreased progressively with each stage of renal failure CKD1–2 to 5 (P for trend = 0.08 and 0.04, respectively). CKD and hypertension were independent determinants of arteriolar narrowing after adjusting for age, gender, diabetes, dyslipidemia, and smoking history. Patients with CKD 5 and diabetes had a larger mean CRAE and CRVE than nondiabetics (141.4 ± 14.9 μm versus 132.9 ± 14.2 μm; 211.1 ± 34.4 μm versus 194.8 ± 23.8 μm).

Conclusions

The microvasculature is narrowed in patients with reduced eGFR.     

An attempt to distinguish between the actions of neuromuscular blocking drugs on the acetylcholine receptor and on its associated ionic channel

The effects of lobeline and tubocurarine on the voltage-clamped endplates of frog sartorius and cutaneous pectoris muscles were examined at room temperature (20-23°C). Like tubocurarine, lobeline causes nondepolarizing neuromuscular blockade. The half-time of decay (t_½) of endplate currents (e.p.c.s) recorded at a holding potential (V_m) of -90 mV was significantly shorter in endplates treated with lobeline (50 μM; mean t_½ ± SEM = 0.41 ± 0.02 ms) or tubocurarine (11.4 μM; t_½ = 0.64 ± 0.04 ms) than in those treated with Mg²⁺ (13 mM; t_½ = 1.39 ± 0.11 ms) or a low concentration of tubocurarine (3 μM; t_½ = 0.87 ± 0.05 ms). Similarly, lobeline (10 μM) shortened the t_½ of untreated miniature e.p.c.s by 35%; tubocurarine, however, abolished miniature e.p.c.s at the concentration required to observe its actions on e.p.c. decay kinetics. The t_½ of e.p.c.s recorded from preparations treated with Mg²⁺ (13 mM), tubocurarine at low concentrations (3 μM), or untreated miniature e.p.c.s was logarithmically related to V_m, being slower at more hyperpolarized values. By contrast, the t_½s of e.p.c.s recorded in either lobeline (50 μM) or tubocurarine (11.4 μM) were independent of voltage in the range -150 to -80 mV. The ability of lobeline to shorten t_½ and to remove the voltage dependence of t_½ was partially antagonized by Mg²⁺ (13 mM). As expected, when lobeline or tubocurarine was removed from the bath or when acetylcholine release from the motor nerve terminals was increased by 4-aminopyridine (20 μM) and Ca²⁺ (10 mM) (in the presence of lobeline or tubocurarine), the amplitude of e.p.c.s increased as a function of time. However, the t_½ of the decay phase of the e.p.c.s remained shortened (i.e., unaltered from the earlier treatment). These results suggest that both tubocurarine and lobeline have at least two distinct postjunctional actions including: (i) a block of the acetylcholine receptor and (ii) a block of the ionic channel associated with the acetylcholine receptor.     

Effect of Heating Modes on Reactive Sintering of Ca3Co4O9 Ceramics

The traditional solid-state reaction method was employed to synthesize bulk calcium cobaltite (Ca349/Ca₃Co₄O₉) ceramics via ball milling the precursor mixture. The samples were compacted using conventional sintering (CS) and spark plasma sintering (SPS) at 850, 900, and 950 °C. The X-ray diffraction (XRD) pattern indicates the presence of the Ca349 phase for samples sintered at 850 and 900 °C. In addition, SPS fosters higher densification (81.18%) than conventional sintering (50.76%) at elevated sintering temperatures. The thermo-gravimetric analysis (TGA) and differential thermal analysis (DTA) performed on the precursor mixture reported a weight loss of ~25.23% at a temperature range of 600–820 °C. This current work aims to analyze the electrical properties (Seebeck coefficient (s), electrical resistivity (ρ), and power factor) of sintered samples as a function of temperature (35–500 °C). It demonstrates that the change in sintering temperature (conventional sintering) did not evince any significant change in the Seebeck coefficient (113–142 μV/K). However, it reported a low resistivity of 153–132 μΩ-m and a better power factor (82–146.4 μW/mK²) at 900 °C. On the contrary, the SPS sintered samples recorded a higher Seebeck coefficient of 121–181 μV/K at 900 °C. Correspondingly, the samples sintered at 950 °C delineated a low resistivity of 145–158 μΩ-m and a better power factor (97–152 μW/mK²).