Evaluation of Microorganisms with Sulfidogenic Metabolic Potential under Anaerobic Conditions

The aim of this work was to identify groups of microorganisms that are capable of degrading organic matter utilizing sulfate as an electron acceptor. The assay applied for this purpose consisted of running batch reactors and monitoring lactate consumption, sulfate reduction and sulfide production. A portion of the lactate added to the batch reactors was consumed, and the remainder was converted into acetic, propionic and butyric acid after 111 hours of operation These results indicate the presence of sulfate-reducing bacteria (SRB) catalyzing both complete and incomplete oxidation of organic substrates. The sulfate removal efficiency was 49.5% after 1335 hours of operation under an initial sulfate concentration of 1123 mg/L. The SRB concentrations determined by the most probable number (MPN) method were 9.0x10(7) cells/mL at the beginning of the assay and 8.0x10(5) cells/mL after 738 hours of operation.

Expression of cancer-testis antigens MAGE-A4 and MAGE-C1 in oral squamous cell carcinoma

Background Tumor markers are genes or their products expressed exclusively or preferentially in tumor cells and cancer-testis antigens (CTAs) form a group of genes with a typical expression pattern expressed in a variety of malignant neoplasms. CTAs are considered potential targets for cancer vaccines. It is possible that the CTA MAGE-A4 (melanoma antigen) and MAGE-C1 are expressed in carcinoma of the oral cavity and are related with survival. Methods This study involved immunohistochemical analysis of 23 patients with oral squamous cell carcinoma (SCC) and was carried out using antibodies for MAGE-A4 and MAGE-C1. Fisher's exact test and log-rank test were used to evaluate the results. Results The expression of the MAGE-A4 and MAGE-C1 were 56.5% and 47.8% without statistical difference in studied variables and survival. Conclusion The expression of at least 1 CTA was present in 78.3% of the patients, however, without correlation with clinicopathologic variables and survival. (c) 2011 Wiley Periodicals, Inc. Head Neck, 2012

Infrared-to-visible upconversion emission in Er3+ doped TeO2-WO3-Bi2O3 glasses with silver nanoparticles

The influence of silver nanoparticles (NPs) on the frequency upconversion luminescence in Er3+ doped TeO2-WO3-Bi2O3 glasses is reported. The effect of the NPs on the Er3+ luminescence was controlled by appropriate heat-treatment of the samples. Enhancement up to 700% was obtained for the upconverted emissions at 527, 550, and 660 nm, when a laser at 980 nm is used for excitation. Since the laser frequency is far from the NPs surface plasmon resonance frequency, the luminescence enhancement is attributed to the local field increase in the proximity of the NPs and not to energy transfer from the NPs to the emitters as is usually reported. This is the first time that the effect is investigated for tellurite-tungstate-bismutate glasses and the enhancement observed is the largest reported for a tellurium oxide based glass. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4754468]

Assessment of Stent Strut Endothelialization in Iliac Arteries of Rabbits

Background: Fast post-implantation stent endothelialization is desirable for theoretically reducing the possibility of stent thrombosis. Objective: To evaluate the extent of sirolimus-eluting stent strut endothelialization (delivered from the luminal and abluminal aspects or abluminal aspect only) in the iliac arteries of rabbits. Methods: The iliac arteries of 10 rabbits were implanted with four sirolimus-eluting stents in the luminal and abluminal aspects, three sirolimus-eluting stents in the abluminal aspect, six polymer-coated stents, and four uncoated stents. After four weeks, the rabbits were euthanized and scanning electron microscopy was performed to quantify the area of exposed stent strut as well as the percentage of endothelialization. Results: The area (mean +/- SD) (mm(2)) of exposed uncoated stent struts, polymer-coated stents, sirulimus-eluting stent in the abluminal and luminal aspects and sirolimus-eluting stent in the abluminal aspect was 0.12 +/- 0.08, 0.09 +/- 0.12, 0.60 +/- 0.67 and 0.05 +/- 0.04, respectively (p = 0.120). The percentage of endothelialization (mean +/- SD) (%) of uncoated stents, polymer-coated stents, sirolimus-eluting stents in the luminal and abluminal aspects and sirolimus-eluting stents in the abluminal aspect was 99 +/- 01, 99 +/- 0. 97 +/- 03 and 99 +/- 0, respectively (p = 0.133). Conclusion: After four weeks of implantation in the iliac arteries of rabbits, both the sirolimus-eluting stents in the luminal plus abluminal aspects and those in the abluminal aspect only showed stent strut endothelialization rates similar to those of the other types of non-drug eluting stents. (Arq Bras Cardiol 2012;99(6):1123-1128)

Prediction of the rate of decline in fetal hemoglobin levels between first and second transfusions in red cell alloimmune disease

Objective To determine variables that predict the rate of decline in fetal hemoglobin levels in alloimmune disease. Method Retrospective review of singleton pregnancies that underwent first and second intrauterine transfusions for treatment of fetal anemia because of maternal Rh alloimmunization in a tertiary referral center. Results Forty-one first intrauterine transfusions were performed at 26.1?weeks (standard deviation, SD, 4.6), mean volume of blood transfused was 44.4?mL (SD 23.5) and estimated feto-placental volume expansion was 51.3% (SD 14.5%). Between first and second transfusion, hemoglobin levels reduced on average 0.40?g/dl/day (SD 0.25). Stepwise multiple regression analysis demonstrated that this rate significantly correlated with hemoglobin levels after the first transfusion, the interval between both procedures, and middle cerebral artery systolic velocity before the second transfusion. Conclusion The rate of decline in fetal hemoglobin levels between first and second transfusions in alloimmune disease can be predicted by a combination of hemoglobin levels after the first transfusion, interval between both procedures, and middle cerebral artery systolic velocity before the second transfusion. (C) 2012 John Wiley & Sons, Ltd.

TUNGSTEN ISOTOPIC COMPOSITIONS IN STARDUST SiC GRAINS FROM THE MURCHISON METEORITE: CONSTRAINTS ON THE s-PROCESS IN THE Hf-Ta-W-Re-Os REGION

We report the first tungsten isotopic measurements in stardust silicon carbide (SiC) grains recovered from the Murchison carbonaceous chondrite. The isotopes (182,183,184,186)Wand (179,180)Hf were measured on both an aggregate (KJB fraction) and single stardust SiC grains (LS+ LU fraction) believed to have condensed in the outflows of low-mass carbon-rich asymptotic giant branch (AGB) stars with close-to-solar metallicity. The SiC aggregate shows small deviations from terrestrial (= solar) composition in the (182)W/(184)Wand (183)W/(184)Wratios, with deficits in (182)W and (183)W with respect to (184)W. The (186)W/(184)W ratio, however, shows no apparent deviation from the solar value. Tungsten isotopic measurements in single mainstream stardust SiC grains revealed lower than solar (182)W/(184)W, (183)W/(184)W, and (186)W/(184)W ratios. We have compared the SiC data with theoretical predictions of the evolution of W isotopic ratios in the envelopes of AGB stars. These ratios are affected by the slow neutron-capture process and match the SiC data regarding their (182)W/(184)W, (183)W/(184)W, and (179)Hf/(180)Hf isotopic compositions, although a small adjustment in the s-process production of (183)W is needed in order to have a better agreement between the SiC data and model predictions. The models cannot explain the (186)W/(184)W ratios observed in the SiC grains, even when the current (185)W neutron-capture cross section is increased by a factor of two. Further study is required to better assess how model uncertainties (e. g., the formation of the (13)C neutron source, the mass-loss law, the modeling of the third dredge-up, and the efficiency of the (22)Ne neutron source) may affect current s-process predictions.

Impact of Protease Inhibitors on Dentin Matrix Degradation by Collagenase

This proof-of-concept study assessed whether the reduction of the degradation of the demineralized organic matrix (DOM) by pre-treatment with protease inhibitors (PI) is effective against dentin matrix loss. Bovine dentin slices were demineralized with 0.87 M citric acid, pH 2.3, for 36 hrs. In sequence, specimens were treated or not (UT, untreated) for 1 min with gels containing epigallocatechin 3-gallate (EGCG, 400 A mu M), chlorhexidine (CHX, 0.012%), FeSO4 (1 mM), NaF (1.23%), or no active compound (P, placebo). Specimens were then stored in artificial saliva (5 days, 37 degrees C) with the addition of collagenase (Clostridium histolyticum, 100 U/mL). We analyzed collagen degradation by assaying hydroxyproline (HYP) in the incubation solutions (n = 5) and evaluated the dentin matrix loss by profilometry (n = 12). Data were analyzed by ANOVA and Tukey's test (p < 0.05). Treatment with gels containing EGCG, CHX, or FeSO4 led to significantly lower HYP concentrations in solution and dentin matrix loss when compared with the other treatments. These results strongly suggest that the preventive effects of the PI tested against dentin erosion are due to their ability to reduce the degradation of the DOM.

Laminated Tubular-channel Ferroelectret Systems from Low-density Polyethylene Films and from Fluoroethylene-propylene Copolymer Films - A Comparison

A template-based lamination technique for the manufacture of ferroelectrets from uniform electret films was recently reported. In the present work, this technique is used to prepare similar ferroelectret structures from low-density polyethylene (LDPE) films and from fluoro-ethylene-propylene (FEP) copolymer films. A comparative analysis of the pressure-, temperature-, and frequency-dependent piezoelectric properties has been performed on the two ferroelectret systems. It is observed that the FEP ferroelectrets exhibit better piezoelectric responses and are thermally more stable. The difference between the piezoelectric d(33) coefficients of the two ferroelectret systems is partially explained here by their different elastic moduli. The anti-resonance peaks of both structures have been investigated by means of dielectric resonance spectroscopy and electroacoustic sound-pressure measurements. A difference of more than 10 kHz is observed between the anti-resonance frequencies of the two ferroelectret systems.

Avaliação da endotelização de hastes de stents em artérias ilíacas de coelhos

FUNDAMENTO: A rápida endotelização pós-implante de stent é ocorrência desejável por teoricamente reduzir a possibilidade de trombose do stent. OBJETIVO: Avaliar a extensão da endotelização de hastes de stents eluidores de sirolimus (liberados da face luminal e abluminal e abluminal exclusivamente) em artérias ilíacas de coelhos. MÉTODOS: Foram implantados em artérias ilíacas de 10 coelhos quatro stents eluidores de sirolimus na face luminal e abluminal, três stents eluidores de sirolimus na face abluminal, seis stents recobertos com polímero e quatro stents sem recobrimento. Após quatro semanas, foi realizada eutanásia e utilizou-se microscopia eletrônica de varredura para quantificação da área de hastes de stent exposta e da porcentagem de endotelização. RESULTADOS: A área (média ± DP) (mm²) de hastes expostas de stent sem recobrimento, stent recoberto com polímero, stent eluidor de sirolimus na face luminal e abluminal e stent eluidor de sirolimus na face abluminal foi de 0,12 ± 0,08; 0,09 ± 0,12; 0,60 ± 0,67 e 0,05 ± 0,04 respectivamente (p = 0,120). A porcentagem de endotelização (média ± DP) (%) de stent sem recobrimento, stent recoberto com polímero, stent eluidor de sirolimus na face luminal e abluminal e stent eluidor de sirolimus na face abluminal foi de 99 ± 01; 99 ± 0; 97 ± 03 e 99 ± 0 respectivamente (p = 0,133). CONCLUSÃO: Após quatro semanas de implante em artérias ilíacas de coelhos, os stents com liberação de sirolimus tanto da face luminal e abluminal quanto da face abluminal exclusivamente apresentaram taxas de endotelização de hastes de stent semelhantes aos apresentados nos demais tipos de stents sem eluição de medicamento.

Evaluation of microorganisms with sulfidogenic metabolic potential under anaerobic conditions

The aim of this work was to identify groups of microorganisms that are capable of degrading organic matter utilizing sulfate as an electron acceptor. The assay applied for this purpose consisted of running batch reactors and monitoring lactate consumption, sulfate reduction and sulfide production. A portion of the lactate added to the batch reactors was consumed, and the remainder was converted into acetic, propionic and butyric acid after 111 hours of operation These results indicate the presence of sulfate-reducing bacteria (SRB) catalyzing both complete and incomplete oxidation of organic substrates. The sulfate removal efficiency was 49.5% after 1335 hours of operation under an initial sulfate concentration of 1123 mg/L. The SRB concentrations determined by the most probable number (MPN) method were 9.0x10(7) cells/mL at the beginning of the assay and 8.0x10(5) cells/mL after 738 hours of operation.

Issues on the mean stress effect in fretting fatigue of a 7050-T7451 Al alloy posed by new experimental data

The aims of this work are: (i) to produce new experimental data for fretting fatigue considering the presence of a mean bulk stress and (ii) to assess two design methodologies against failure by fretting fatigue. Tests on a cylinder–flat contact configuration were conducted using a fretting apparatus mounted on a servo-hydraulic machine. The material used for both the pads and fatigue specimen was an aeronautical 7050-T7451 Al alloy. The experimental program was designed with all relevant parameters, apart from the mean bulk load (always applied before the contact loads), kept constant. The mean bulk stress varied from compressive to tensile values while maintaining a high peak pressure in order to encourage crack initiation. Two methodologies against fretting fatigue are proposed and confronted against the experimental data. The non-local stress-based methodology considers the evaluation of a critical plane fatigue criterion at the center of a process zone located beneath the contacting surfaces. The results showed that it correctly predicts crack initiation, but was not capable to provide successful prediction of the integrity of the specimens. Alternatively, we considered a crack arrest criterion which has the potential to provide a more complete description about the integrity of the specimens.