The anions [(ZrOH(CO3)3)2]6− and [(ZrOH(C2O4)3)2]6−: single crystal X-ray diffraction studies of the complexes guanidinium zirconium carbonate [(C(NH2)3)3ZrOH(CO3)3·H2O]2 and sodium zirconium oxalate Na6(ZrOH(C2O4)3)2·7H2O

The complex [(C(NH2)3)3ZrOH(CO3)3·H2O]2 (A) has been shown by means of a single crystal X-ray diffraction study to contain [C(NH2)3]+ cations and dimeric anions of formulation [(ZrOH(CO3)3)2]6−. The anion is centrosymmetric with each metal being bonded to two bridging OH groups and three chelating CO2−3 ions. The Zr atoms are thus eight coordinate with a dodecahedral environments. The ZrO distances formed by the bridgng OH groups are shorter than those formed through zirconiu carbonate interactions. The non-bonded Zr…Zr distance is 3.47(2) Å. An infrared spectroscopic investigation of A provides data which support the findings of the crystallographic study. Likewise the complex Na6(ZrOH(CO2O4)3)2·7H2O (B) contains the anion [(ZrOH(C2O4)3)2]6−. This anion is structurally related to the anion in A as each Zr atom has an eight-coordinate dodecahedral environment being bonded to two bridging OH groups and three chelating oxalate ligands, but has no imposed crysallographic symmetry. The Zr…Zr non-bonded distance is 3.50(1) Å. The OZrO bridge angles are 69.7(4)° and A and 67.4(3)° in B.

On the barrier properties of the cornea: a microscopy study of the penetration of fluorescently labeled nanoparticles, polymers, and sodium fluorescein

Overcoming the natural defensive barrier functions of the eye remains one of the greatest challenges of ocular drug delivery. Cornea is a chemical and mechanical barrier preventing the passage of any foreign bodies including drugs into the eye, but the factors limiting penetration of permeants and nanoparticulate drug delivery systems through the cornea are still not fully understood. In this study, we investigate these barrier properties of the cornea using thiolated and PEGylated (750 and 5000 Da) nanoparticles, sodium fluorescein, and two linear polymers (dextran and polyethylene glycol). Experiments used intact bovine cornea in addition to bovine cornea de-epithelialized or tissues pretreated with cyclodextrin. It was shown that corneal epithelium is the major barrier for permeation; pretreatment of the cornea with β-cyclodextrin provides higher permeation of low molecular weight compounds, such as sodium fluorescein, but does not enhance penetration of nanoparticles and larger molecules. Studying penetration of thiolated and PEGylated (750 and 5000 Da) nanoparticles into the de-epithelialized ocular tissue revealed that interactions between corneal surface and thiol groups of nanoparticles were more significant determinants of penetration than particle size (for the sizes used here). PEGylation with polyethylene glycol of a higher molecular weight (5000 Da) allows penetration of nanoparticles into the stroma, which proceeds gradually, after an initial 1 h lag phase.

Clinical comparison between the bleaching efficacy of 37% peroxide carbamide gel mixed with sodium perborate with established intracoronal bleaching agent

Objective. The aim was to evaluate the bleaching efficacy of sodium perborate/37% carbamide peroxide paste and traditional sodium perborate/distilled water for intracoronal bleaching. Study design. Thirty patients with dark anterior teeth were divided into 2 groups (n = 15): group A: sodium perborate/ distilled water; and group B: sodium perborate/37% carbamide peroxide paste. The bleaching treatment limited each patient to the maximum of 4 changes of the bleaching agent. Initial and final color shades were measured using the Vita Lumin shade guide. Results. Data was analyzed with Wilcoxon test for initial and final comparison according to the bleaching agent, demonstrating efficacy of the bleaching treatment with both agents. Mann-Whitney test was used for comparison of the efficacy of the bleaching agents, showing that there was no significant difference between them. Conclusion. The sodium perborate/37% carbamide peroxide association for intracoronal bleaching has proven to be as effective as sodium perborate/distilled water. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2009; 107: e43-e47)

Effect of meloxicam and diclofenac sodium on peri-implant bone healing in rats

Background: This study evaluated the effects of diclofenac sodium and meloxicam on peri-implant bone healing. Methods: Thirty male rats were divided into three groups: the control group (CG) received no drug; the diclofenac sodium group (DSG) received 1.07 mg/kg twice a day for 5 days; and the meloxicam group (MG) received 0.2 mg/kg daily for 5 days. A screw-shaped titanium implant was placed in the tibia. Fluorochromes, oxytetracycline (OxT), calcein (CA), and alizarin (AL), were injected at 7, 14, and 21 days, respectively, after implantation, and the animals were sacrificed 28 days after implant placement. The percentages of OxT-, CA-, and AL-labeled bone as well as the percentages of bone-to-implant contact (BIC), cortical bone area (CBA), and trabecular bone area (TBA) within the implant threads were evaluated. Results: Bone healing was delayed in the DSG during the first 14 days after implant placement (OxT-labeled bone: DSG: 5.3% +/- 7.3% versus CG: 13.2% +/- 9.8%, P= 0.002, and versus MG: 14.4% +/- 13.1%, P = 0.05). The percentages of BIC (DSG: 49.6% +/- 21.9%; MG: 67.1% +/- 22.8%; and CG: 68.1% +/- 22.8%) and CBA (DSG: 63.7% +/- 21.2%; MG: 82.7% +/- 12.4%; CG: 84.9% +/- 10.6%) were lower in the DSG compared to the MG and CG (P<0.001). The percentage of TBA was significantly greater in the DSG compared to the MG and CG (DSG: 36.3% +/- 21.2% versus MG: 17.3% +/- 12.7% and versus CG: 15.1% +/- 10.6%; P<0.001). Conclusion: Diclofenac sodium seemed to delay peri-implant bone healing and to decrease BIC, whereas meloxicam had no negative effect on peri-implant bone healing.

Structural and spectroscopic characterization of poly(styrene sulfonate) films doped with neodymium ions

This work reports the structural and spectroscopy characterization of poly(styrene sulfonate) (PSS) films doped with neodymium (Nd) ions. Nd-PSS films were processed using the acid of poly(styrene sulfonate) - H-PSS and neodymium nitrate - Nd(NO(3))(3); the maximum incorporation of Nd ions in the polymeric matrix was equal 19.3%. The absorption in the UV-Vis-NIR spectral region presents typical electronic transitions of Nd 3, ions, with well resolved peaks. The infrared spectra present the transition bands of PSS with characteristic line shape broadening, and the presence of vibrational modes of N-O groups in the range of 1400-720 cm(-1), prove the permanence of Nd(NO(3))(x), with x = 1, 2 and/or 3. in the H-PSS matrix. UV-Vis site selective photoluminescence data indicate that the incorporation of Nd 31 introduces a blue shift in PSS emission (325-800 nm), decreasing the interaction between adjacent PSS lateral groups (aromatic rings). Nd(3+) reabsorption and energy transfer effects between the PSS matrix and Nd(3+) were also observed. The IR emission of Nd-PSS films at 1076 rim ((4)F(3/2) -> (4)I(11/2)) present constant efficiency, independent on Nd(3+) concentration. The Judd-Ofelt theory was employed to analyze radiative properties. The excitation spectra prove the energy transfer between the polymeric matrix and Nd(3+). Complex impedance data was used to probe relaxation processes during the charge transport within the polymeric matrix. (C) 2008 Elsevier B.V. All rights reserved.

Energy transfer processes in Yb(3+)-Tm(3+) co-doped sodium alumino-phosphate glasses with improved 1.8 mu m emission

Sodium alumino-phosphate glasses co-doped with Yb(3+) and Tm(3+) ions have been prepared with notably low OH(-) content, and characterized from the viewpoint of their spectroscopic properties. In these glasses, Yb(3+) acts as an efficient sensitizer of excitation energy at 0.98 mu m - which can be provided by high power and low cost diode lasers, and subsequently undergoes non-resonant energy transfer to Tm(3+) ions ((2)F(5/2), (3)H(6) --> (2)F(7/2), (3)H(5)). Through this process, the emitting level (3)F(4) is rapidly populated, generating improved emission at 1.8 mu m ((3)F(4) --> (3)H(6)). In order to guarantee the efficiency of such favorable energy transfer, energy losses via multiphonon decay, Yb-Yb radiative trapping, and non- radiative transfer to OH(-) groups were evaluated, and minimized when possible. The dipole - dipole energy transfer microscopic parameters corresponding to Yb(3+) --> Tm(3+), Yb(3+) --> Yb(3+) and Tm(3+) --> Tm(3+) transfers, calculated by the Forster-Dexter model, are C(Yb-Tm) = 2.9 x 10(-40) cm(6) s(-1), C(Yb-Yb) = 42 x 10(-40) cm(6) s(-1) and C(Tm-Tm) = 43 x 10(-40) cm(6) s(-1), respectively.

Sodium Tungstate on Some Biochemical Parameters of the Parotid Salivary Gland of Streptozotocin-Induced Diabetic Rats: A Short-Term Study

Several studies have shown the antidiabetic properties of sodium tungstate. In this study, we evaluated some biochemical parameters of the parotid salivary gland of streptozotocin-induced diabetic rats treated with sodium tungstate solution (2 mg/ml). The studied groups were: untreated control (UC), treated control (TC), untreated diabetic (UD), and treated diabetic (TD). After 2 and 6 weeks of treatment, parotid gland was removed and total protein and sialic acid (free and total) concentration and amylase and peroxidase activities were determined. Data were compared by variance analysis and Tukey test (p < 0.05). The sodium tungstate treatment modestly decreased the glycemia of streptozotocin-induced diabetic rats. At week 2 of the study, parotid gland of diabetic rats presented a reduction of total protein concentration (55%) and an increase of amylase (120%) and peroxidase (160%) activities, free (150%) and total (170%) sialic acid concentration. No alteration in the evaluated parameters at week 6 of the study was observed. Sodium tungstate presented no significant effect in parotid gland. Our results suggest that diabetes causes initial modification in biochemical composition of parotid. However, this gland showed a recovery capacity after 6 week of the experimental time. Sodium tungstate has no effect in peripheral tissues, such as salivary glands.

Elevated dietary sodium intake exacerbates myocardial hypertrophy associated with cardiac-specific overproduction of angiotensin II

Introduction/hypothesis
Cardiac hypertrophy is an independent risk factor predictive of cardiovascular disease and is significantly associated with morbidity and mortality. The mechanism by which angiotensin II (Ang II) and dietary sodium exert additive effects on the development of cardiac hypertrophy is unclear. The goal of this study was to evaluate the hypothesis that, where there is a genetic predisposition to Ang II-dependent hypertrophy, there is also an increased susceptibility to sodium-induced hypertrophy mediated by AT₁-receptor expression.

Methods
Diets of low sodium (LS, 0.3% w:w) and high sodium (HS, 4.0% w:w) content were fed to adult (age 25 weeks) control wild-type mice (WT) and to weeks) control wild-type mice (WT) and to transgenic mice exhibiting cardiac specific overexpression of angiotensinogen (TG). At the conclusion of a 40-day dietary treatment period, cardiac tissue weights were compared and the relative expression levels of Ang II receptor subtypes (AT_1A and AT₂) were evaluated using RT-PCR.

Results
WT and TG mice fed HS and LS diets maintained comparable weight gains during the treatment period. The normalised heart weights of TG mice were elevated compared to WT, and the extent of the increase was greater for mice maintained on the HS diet treatments (WT 12% vs. TG 41% increase in cardiac weight index). While a similar pattern of growth was observed for ventricular tissues, the atrial weight parameters demonstrated an additional significant effect of dietary sodium intake on tissue weight, independent of animal genetic type. No differences in the relative (GAPDH normalised) expression levels of AT_1A- and AT₂-receptor mRNA were observed between diet or animal genetic groups.

Conclusion
This study demonstrates that, where there is a pre-existing genetic condition of Ang II-dependent cardiac hypertrophy, the pro-growth effect of elevated dietary sodium intake is selectively augmented. In TG and WT mice, this effect was evident with a relatively short dietary treatment intervention (40 days). Evaluation of the levels of Ang II receptor mRNA further demonstrated that this differential growth response was not associated with an altered relative expression of either AT_1A- or AT₂-receptor subtypes. The cellular mechanistic bases for this specific Ang II-dietary sodium interaction remain to be elucidated.

Ion conduction and phase morphology in sulfonate copolymer ionomers based on ionic liquid–sodium cation mixtures

A series of sulfonate based copolymer ionomers based on a combination of ionic liquid and sodium cations have been prepared in different ratios. This system was designed to improve the ionic conductivity of ionomers by partially replacing sodium cations with bulky cations that are less associated with anion centres on the polymer backbone. This provides more conduction sites for sodium to ‘hop’ to in the ionomers. Characterization showed the glass transition and 15N chemical shift of the ionomers did not vary significantly as the amount of Na+ varied, while the ionic conductivity increased with decreasing Na+ content, indicating conductivity is increasingly decoupled from Tg. Optical microscope images showed phase separation in all compositions, which indicated the samples were inhomogeneous. The introduction of low molecular weight plasticizer (PEG) reduced the Tg and increased the ionic conductivity significantly. The inclusion of PEG also led to a more homogeneous material.

Water-soluble acrylamide sulfonate copolymer for inhibiting shale hydration

Here we report a water-soluble acrylamide sulfonate copolymer for inhibiting shale hydrate formation. The copolymer, denoted as PANAA, was synthesized via copolymerization of acrylamide (AM), N,N-diallylbenzylamine (NAPA), acrylic acid (AA), and 2-(acrylamide)-2-methylpropane-1-sulfonic acid (AMPS). The performance of this new water-soluble copolymer for inhibiting shale hydration was investigated for the first time. The retention ratio of apparent viscosity of 2 wt % PANAA solution can reach 61.6% at 130 C and further up to 72.2% with 12 000 mg/L NaCl brine. The X-ray diffraction studies show that the addition of copolymer PANAA (5000 mg/L), in combination with a low loading of KCl (3 wt %), remarkably reduces the interlayer spacing of sodium montmorillonite (Na-MMT) in water from 19.04 to 15.65 Å. It has also found that these copolymer solutions, blending with KCl, can improve the retention of indentation hardness from 22% to 74% and increase the antiswelling ratio up to 84%. All results have demonstrated that the PANAA copolymer not only has excellent temperature-resistance and salt-tolerance but also exhibits a significant effect on inhibiting the hydration of clays and shale. © 2014 American Chemical Society.

An anti-biodegradable hydrophobic sulfonate-based acrylamide copolymer containing 2,4-dichlorophenoxy for enhanced oil recovery

We report here a novel anti-biodegradable hydrophobic acrylamide copolymer that was prepared from acrylamide, acrylic acid, sodium 3-(allyloxy)-2-hydroxypropane-1-sulfonate and N-allyl-2-(2,4-dichlorophenoxy) acetamide using the 2,2'-azobis(2-methylpropionamide) dihydrochloride initiation system. Subsequently, the copolymer was characterized by FT-IR, 1H NMR, TG-DTG and water-solubility. And the biodegradability test indicated that the copolymer was not deemed to be readily biodegradable via a closed bottle test established by the Organization for Economic Co-operation and Development (OECD 301 D). Meanwhile the copolymer could significantly enhance the viscosity of the aqueous solution in comparison with partially hydrolyzed polyacrylamide. A viscosity retention of 51.9% indicated the result of a dramatic improvement of temperature tolerance. And then the excellent salt resistance, shear resistance, viscoelasticity, long-term stability of the copolymer could be obtained, which provides a good theoretical foundation for the application in enhanced oil recovery. In addition, this copolymer exerted stronger mobility control ability with a resistance factor of 22.1 and a residual resistance factor of 5.0, and superior ability for enhanced oil recovery of 12.9%. Hence, the copolymer has potential application for enhanced oil recovery in high-temperature and high-salinity reservoirs.

Thermally stable imidazoline-based sulfonate copolymers for enhanced oil recover

Novel imidazoline-based sulfonate copolymers (noted PAMDSCM and PAMPSCM) were successfully prepared by copolymerization of acrylamide (AM), acrylic acid (AA), 1-acrylamido ethyl-2-oleic imidazoline (ACEIM) with the sodium salts of 3-(diallyl-amino)-2-hydroxypropyl (NDS) or 2-acrylamido-2-methylpropane sulfonic acid (AMPS), respectively. The copolymers were characterized by infrared (IR) spectroscopy, 1H nuclear magnetic resonance (1H NMR) spectroscopy, pyrene fluorescence probe spectroscopy, viscosimetry and thermogravimetry (TG). Both PAMDSCM and PAMPSCM copolymers had excellent high-temperature tolerance in comparison with the same concentration of HPAM, and the residual viscosities were 32.0 mPa s and 31.3 mPa s (viscosity retention rates were 38.8% and 37.1%) at 140 °C, respectively. The copolymers possessed superior long-term thermal stability and their residual viscosity rates were up to 81.8% and 63.8% (52.9 mPa s and 47.1 mPa s) lasting 1.5 hours at 100 °C and 170 s-1, respectively.

Dietary sources and sodium intake in a sample of Australian preschool children

OBJECTIVES: To assess dietary sodium intake and the food sources of sodium in a sample of Australian preschool children. DESIGN: Cross-sectional. SETTING: Mothers were followed up when children were approximately 3.5 years of age after participating in a cluster randomised controlled trial: the Melbourne Infant Feeding Activity and Nutrition Trial Program. PARTICIPANTS: 251 Australian children aged 3.5±0.19 (SD) years. PRIMARY AND SECONDARY OUTCOME MEASURES: The average daily sodium intake was determined using three unscheduled 24 h dietary recalls. The contributions of food groups, core, discretionary and processed foods to daily sodium intake were assessed. RESULTS: The average sodium intake was 1508±495 (SD) mg/day, (salt equivalent 3.9±1.3 (SD) g/day) and 87% of children exceeded the Australian Upper Level of Intake (UL) for sodium of 1000 mg/day (salt equivalent 2.6 g/day). Main food sources of sodium were cereal/cereal products (25%), milk products (19%), meat, poultry/game (17%) and cereal-based products (15%). Core foods contributed 65%, and discretionary foods 35% of total daily sodium intake, and within the total diet, minimally processed, processed, processed culinary ingredient and ultraprocessed foods contributed 16%, 35%, 1% and 48% of sodium, respectively. CONCLUSIONS: Within this sample, most children exceeded the recommended UL for sodium. Core and ultraprocessed foods were key sources of sodium which suggests that reductions in the sodium content of these foods are required to reduce sodium intake in young children. These data also provide further support for public health campaigns that seek to reduce consumption of energy-dense, nutrient-poor foods.

Polymer architecture effect on sodium ion transport in PSTFSI-based ionomers: a molecular dynamics study

In this study, we investigated the effect of polymer architecture on the ion dynamics and local structure to understand the factors that might lead to the design of highly conductive and mechanically robust polyelectrolytes. Molecular dynamic simulations were undertaken on the sodium poly[(4-styrenesulfonyl) (trifluoromethanesulfonyl) imide] P(STFSINa) homopolymer and its copolymers with either ether or styrene spacer groups to investigate the spacer length and polarity dependence of Na-ion transport. Using a scaled charge model, we observed a continuous ion aggregate network in the homopolymer, which facilitates the fast ion dynamics despite the rigid polymer matrix. The longest spacer groups disrupt this percolating ionic network differently, with the ether group being more disruptive than the styrene group, and leading to more discrete ionic aggregates. The copolymer with the ether spacer was also found to result in an alternative Na-ion diffusion mechanism.

Bacteriologic investigation of the effects of sodium hypochlorite and chlorhexidine during the endodontic treatment of teeth with apical periodontitis

SIQUEIRA JR. et al. Bacteriologic investigation of the effects of sodium hypochlorite and chlorhexidine during the endodontic treatment of teeth with apical periodontitis. Oral Surg. Oral Med. Oral Pathol. Oral Radiol. Endod., v. 104, n. 1, p. 122-130, 2007.