Numerical investigation of the three-dimensional secondary instabilities in the time-developing compressible mixing layer

Mixing layers are present in very different types of physical situations such as atmospheric flows, aerodynamics and combustion. It is, therefore, a well researched subject, but there are aspects that require further studies. Here the instability of two-and three-dimensional perturbations in the compressible mixing layer was investigated by numerical simulations. In the numerical code, the derivatives were discretized using high-order compact finite-difference schemes. A stretching in the normal direction was implemented with both the objective of reducing the sound waves generated by the shear region and improving the resolution near the center. The compact schemes were modified to work with non-uniform grids. Numerical tests started with an analysis of the growth rate in the linear regime to verify the code implementation. Tests were also performed in the non-linear regime and it was possible to reproduce the vortex roll-up and pairing, both in two-and three-dimensional situations. Amplification rate analysis was also performed for the secondary instability of this flow. It was found that, for essentially incompressible flow, maximum growth rates occurred for a spanwise wavelength of approximately 2/3 of the streamwise spacing of the vortices. The result demonstrated the applicability of the theory developed by Pierrehumbet and Widnall. Compressibility effects were then considered and the maximum growth rates obtained for relatively high Mach numbers (typically under 0.8) were also presented.AFOSR Air Force Office of Scientific Research[FA9550-07-1-0055]FAPES

Comparison of Floseals and Tranexamic Acid for Bleeding Control after Total Knee Arthroplasty: a Prospective Randomized Study

OBJECTIVE: Tranexamic acid (TXA) and the hemostatic agent Floseals have already been used to minimize bleeding during total knee arthroplasty (TKA). METHODS: We conducted a prospective, randomized study of 90 patients with indications for TKA. Following inclusion, the participants were randomly allocated in blocks to the following 3 groups: control, Floseals and TXA. Bleeding parameters, including decreases in hemoglobin (Hb), drain output, number of blood transfusions and complications, were assessed. ClinicalTrials.gov: NCT02152917. RESULTS: The mean decrease in Hb was highest in the control group (4.81±1.09 g/dL), followed by the Floseals (3.5±1.03 g/dL) and TXA (3.03±1.2 g/dL) groups. The Floseals and TXA groups did not differ, and both performed better than the control group. The mean total drain output was 901.3±695.7 mL in the control group, 546.5±543.5 mL in the TXA group and 331.2±278.7 mL in the Floseals group. Both TXA and Floseals had significantly less output than the control group, and Floseals had significantly less output than TXA. The number of blood transfusions was very small in all 3 groups. CONCLUSION: The use of TXA or Floseals was associated with less blood loss than that of the control group among patients undergoing primary TKA, as measured both directly (intraoperative bleeding + drainage) and on the basis of a decrease in Hb, without differences in the rate of complications. TXA and Floseals showed similar decreases in Hb and total measured blood loss, but the drain output was smaller in the Floseals group

Analysis of inducers of xylanase and cellulase activities production by Ganoderma applanatum LPB MR-56

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Histometric analysis of alveolar bone regeneration with expanded polytetrafluoroethylene (e-PTFE) and latex membranes

AIM: To investigate the amount of connective tissue migrated into the extraction socket using EPTFE and latex membranes. METHODS: Seventeen rats were selected and randomly divided into 3 groups: e-PTFE membrane (n = 6), Latex membrane (n = 6) and Control (no membrane, n=5). After extraction of the maxillary right incisor, the animals of the test groups were subjected to alveolar guided bone regeneration (GBR) surgery and received an expanded polytetrafluoroethylene (e-PTFE) and a latex membrane, respectively. Thirty days after surgery, the animals were killed and histometric analysis was done to evaluate the migration of connective tissue. Data were analyzed statistically by one-way ANOVA and multiple-comparison Tukey's test at 5% significance level. RESULTS: There was statistically significant difference between groups e-PTFE and Latex (p=0.001), and between groups e-PTFE and Control (p=0.012), but no significant difference was found between groups Latex and Control (p=0.416). CONCLUSIONS: The e-PTFE membrane showed better results and appeared more adequate for GBR therapy, forming a barrier to prevent the migration of connective tissue into the extraction socket. The latex membrane, on the other hand, did not show benefits over the control group

Tri-n-butyltin Hydride-Mediated radical reactions of ortho-and meta-Iodobenzamides to synthesize benzomacrolactams: surprising formation of biphenyl compounds from meta-regioisomers

Reactions of methyl 4-O-allyl-2,3-di-O-benzyl-6-deoxy-6-(3-iodobenzoylamino)-α-D-galactopyranoside, its gluco epimer, methyl 2,3-di-O-benzyl-6-deoxy-6-(3-iodobenzoylamino)-4-O-(1-pentenyl)-α-D-glucopyranoside and its ortho-regioisomer with tri-n-butyltin hydride were performed in different conditions. Depending on reaction conditions the three meta-iodo isomers gave a surprising amount of biphenyl compounds. The 2-iodo isomer led only to the undesired but expected hydrogenolysis product. No cyclized products were isolated in all the reactions. The structures of the new biphenyl products were elucidated by ¹H and 13C NMR spectroscopy, DEPT, COSY, HMQC and HMBC experiments and ESI-MS/MS. Mechanisms for the formation of these new biphenyl derivatives and hypotheses to explain the different outcomes for radical reactions of 3- or 2-iodobenzamides were presented

Fios que Tecem o Tempo Escolar: do ritmo padrão à simultaneidade

Este texto tem por objetivo tecer os fios que, de modo complexo, atam e desatam, de forma silenciosa, a constituição do tempo em duas escolas com classes multisseriadas da Ilha de Maré, problematizando a ideia de ritmo padrão e apontando a simultaneidade como possibilidade para o tempo escolar. Do ponto de vista metodológico foi adotada a narrativa (auto)biográfica, e a técnica de pesquisa selecionada foi a entrevista narrativa. O estudo realizado aponta que o tempo escolar, das duas escolas pesquisadas, é convidado a reconhecer a existência e a legitimidade de outros tempos, para além do seu: o tempo da maré, o tempo do trabalho, o tempo das práticas simbólicas, o tempo livre e as temporalidades dos sujeitos

A Large-Scale Genetic Analysis Reveals a Strong Contribution of the HLA Class II Region to Giant Cell Arteritis Susceptibility

We conducted a large-scale genetic analysis on giant cell arteritis (GCA), a polygenic immune-mediated vasculitis. A case-control cohort, comprising 1,651 case subjects with GCA and 15,306 unrelated control subjects from six different countries of European ancestry, was genotyped by the Immunochip array. We also imputed HLA data with a previously validated imputation method to perform a more comprehensive analysis of this genomic region. The strongest association signals were observed in the HLA region, with rs477515 representing the highest peak (p = 4.05 × 10−40, OR = 1.73). A multivariate model including class II amino acids of HLA-DRβ1 and HLA-DQα1 and one class I amino acid of HLA-B explained most of the HLA association with GCA, consistent with previously reported associations of classical HLA alleles like HLA-DRB1∗04. An omnibus test on polymorphic amino acid positions highlighted DRβ1 13 (p = 4.08 × 10−43) and HLA-DQα1 47 (p = 4.02 × 10−46), 56, and 76 (both p = 1.84 × 10−45) as relevant positions for disease susceptibility. Outside the HLA region, the most significant loci included PTPN22 (rs2476601, p = 1.73 × 10−6, OR = 1.38), LRRC32 (rs10160518, p = 4.39 × 10−6, OR = 1.20), and REL (rs115674477, p = 1.10 × 10−5, OR = 1.63). Our study provides evidence of a strong contribution of HLA class I and II molecules to susceptibility to GCA. In the non-HLA region, we confirmed a key role for the functional PTPN22 rs2476601 variant and proposed other putative risk loci for GCA involved in Th1, Th17, and Treg cell function