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1.
An Sist Sanit Navar ; 46(3)2023 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-37994840

RESUMO

Chyle leak is a pathological extravasation of chyle into the peritoneal cavity after a surgical injury. It is an uncommon complication in colorectal surgery. In most cases, conservative treatment is effective, although it often entails prolonged hospital stays. We present the case of a 60-year-old female with chyle leak after laparoscopic left hemicolectomy with complete mesocolic excision who underwent successful outpatient conservative management. We found no other cases of successful conservative outpatient treatment in the consulted literature. Adequate outpatient management may provide significant benefits by reducing hospital costs and improving patient´s quality of life, while maintaining the possibility of starting adjuvant treatment if indicated.


Assuntos
Quilo , Laparoscopia , Feminino , Humanos , Pessoa de Meia-Idade , Tratamento Conservador/efeitos adversos , Complicações Pós-Operatórias/terapia , Complicações Pós-Operatórias/etiologia , Pacientes Ambulatoriais , Qualidade de Vida , Colectomia/efeitos adversos , Laparoscopia/efeitos adversos
2.
J Clin Med ; 12(13)2023 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-37445283

RESUMO

Aim: This study aimed to evaluate the effectiveness and tolerability of intensifying the dose of canagliflozin from 100 mg/day (CANA100) to 300 mg/day (CANA300) in patients with type 2 diabetes (T2DM) and suboptimal metabolic control in a real-world setting. Methods: A multicenter observational study was conducted on adult patients with T2DM who initiated treatment with CANA100 and subsequently required intensification to CANA300. The primary outcome measures were changes in HbA1c and weight at 6 months after the switch and at the end of the follow-up period. Results: A total of 317 patients met the inclusion criteria (59.6% male, mean age 62.2 years, baseline HbA1c 7.55%, weight 88.6 kg, median duration of treatment with CANA100 9.9 months). Switching to CANA300 resulted in a significant reduction in HbA1c (6 months: -0.33%; last visit: -0.47%, both p < 0.0001) and weight (6 months: -1.8 kg; last visit: -2.9 kg, both p < 0.0001) over a median follow-up period of 20.8 months. The proportion of patients that achieved HbA1c < 7% increased from 26.7% with CANA100 to 51.6% with CANA300 (p < 0.0001). Among individuals with poor baseline glycemic control (HbA1c > 8%, mean 9.0%), HbA1c was significantly reduced by -1.24% (p < 0.0001). Furthermore, significant improvements were observed in fasting plasma glucose (FPG), blood pressure (BP), liver enzymes, and albuminuria. No unexpected adverse events were reported. Conclusions: Intensifying the treatment to CANA300 in a real-world setting resulted in further significant and clinically relevant reductions in FPG, HbA1c, weight, and BP in patients with T2DM. The switch was particularly effective in patients with higher baseline HbA1c levels.

3.
J Clin Med ; 11(19)2022 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-36233490

RESUMO

The Real-WECAN study evaluated the real-life effectiveness and safety of canagliflozin 100 mg daily (initiated in SGLT-2 inhibitors naïve patients) and canagliflozin 300 mg daily (switching from canagliflozin 100 mg or other SGLT-2 inhibitors) in individuals with type 2 diabetes. The objectives of this sub-analysis were to estimate the eGFR slope over the follow-up period and to identify predictive factors of eGFR decline in a multiple linear regression analysis. A total of 583 patients (279 on canagliflozin 100 mg and 304 on canagliflozin 300 mg) were included, with median follow-up at 13 months. The patients had a mean age of 60.4 years, HbA1c of 7.76%, BMI of 34.7 kg/m2, eGFR below 60 mL/min/1.73 m2 8.6%, and urine albumin-to-creatinine ratio (UACR) above 30 mg/g 22.8%. eGFR decreased by −1.9 mL/min/1.73 m2 (p < 0.0001) by the end of the study. The mean eGFR slope during the maintenance phase was −0.16 mL/min/1.73 m2 per year. There were no significant differences between both doses of canagliflozin in the eGFR reduction or in the eGFR slope. The best predictive multivariate model of eGFR decline after canagliflozin therapy included age, hypertension, combined hyperlipidemia, heart failure, eGFR and severely increased albuminuria. All these variables except hypertension were independently associated with the outcome. In conclusion, in this real-world study, individuals with older age, combined hyperlipidemia, heart failure, higher eGFR and UACR > 300 mg/g showed a greater decline in their eGFR after canagliflozin treatment.

4.
J Clin Med ; 9(7)2020 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-32708943

RESUMO

The aims of this multicentric retrospective study were to assess in a real-world setting the effectiveness and safety of canagliflozin 100 mg/d (CANA100) as an add-on to the background antihyperglycemic therapy, and to evaluate the intensification of prior sodium-glucose co-transporter type 2 inhibitor (SGLT-2i) therapy by switching to canagliflozin 300 mg/d (CANA300) in patients with T2DM. One cohort of SGLT2i-naïve patients with T2DM who were initiated on CANA100 and a second cohort of patients with prior background SGLT-2i therapy who switched to CANA300 were included in the study. The primary outcome of the study was the mean change in HbA1c over the follow-up time. In total, 583 patients were included-279 in the cohort of CANA100 (HbA1c 8.05%, weight 94.9 kg) and 304 in the cohort of CANA300 (HbA1c 7.51%, weight 92.0 kg). Median follow-up periods in both cohorts were 9.1 and 15.4 months respectively. CANA100 was associated to significant reductions in HbA1c (-0.90%) and weight (-4.1 kg) at the end of the follow-up. In those patients with baseline HbA1c > 8% (mean 9.25%), CANA100 lowered HbA1c levels by 1.51%. In the second cohort, patients switching to CANA300 experienced a significant decrease in HbA1c (-0.35%) and weight (-2.1 kg). In those patients with baseline HbA1c > 8% (mean 8.94%), CANA300 lowered HbA1c levels by 1.12%. There were significant improvements in blood pressure in both cohorts. No unexpected adverse events were reported. In summary, CANA100 (as an add-on therapy) and CANA300 (switching from prior SGLT-2i therapy) significantly improved several cardiometabolic parameters in patients with T2DM.

5.
Nefrologia (Engl Ed) ; 38(6): 616-621, 2018.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-29903522

RESUMO

BACKGROUND: A multidisciplinary approach and Doppler ultrasound (DU) assessment for the creation and maintenance of arteriovenous fistulas (AVF) for haemodialysis can improve prevalence and patency. The aim of this study was to analyse the impact of a new multidisciplinary vascular access (VA) clinic with routine DU. MATERIAL AND METHODS: We analysed the VA clinic results from 2014 and 2015, before and after the implementation of a multidisciplinary team protocol (vascular surgeon/nephrologist) with routine DU in preoperative mapping and prevalent AVF. RESULTS: We analysed 345 and 364 patients from 2014 and 2015 respectively. The number of surgical interventions was similar in both periods (p=.289), with a trend towards an increase in preventive surgical repair of AVF in 2015 (17 vs. 29, p=.098). 155 vs. 169 new AVF were performed in 2014 and 2015, with a significantly lower primary failure rate in 2015 (26.4 vs. 15.3%, p=.015), and a non-significant increase in radiocephalic AVF, 25.8 vs. 33.2% (n=40 vs. 56), p=.159. The concordance between the indication at the clinic and the surgery performed also increased (81.3 vs. 93.5%, p=.001). Throughout 2015 fewer complementary imaging test were requested from the clinic (78 vs. 35, p <.001), with a corresponding reduction in costs (€87,716 vs. €59,445). CONCLUSIONS: Multidisciplinary approach with routine DU can improve VA results, with a decrease in primary failure rate, higher likelihood of radiocephalic AVF, better management of dis-functioning AVF and lower radiological test costs.


Assuntos
Derivação Arteriovenosa Cirúrgica , Vasos Sanguíneos/diagnóstico por imagem , Diálise Renal/métodos , Ultrassonografia Doppler , Humanos , Equipe de Assistência ao Paciente , Estudos Retrospectivos
6.
BMC Genet ; 17(1): 109, 2016 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-27421647

RESUMO

BACKGROUND: MicroRNAs (miRNAs) are a novel class of endogenous, non-coding, single-stranded RNAs capable of regulating gene expression by suppressing translation or degrading mRNAs. Single nucleotide polymorphisms (SNP) can alter miRNA expression, resulting in diverse functional consequences. Previous studies have examined the association of miRNA SNPs with breast cancer (BC) susceptibility. The contribution of miRNA gene variants to BC susceptibility in South American women had been unexplored. Our study evaluated the association of the SNPs rs895819 in pre-miR27a, rs11614913 in pre-miR-196a2, rs6505162 in pre-miR-423, rs4919510 in miR-608, and rs2682818 in pre-mir-618 with familial BC and early-onset non-familial BC in non-carriers of BRCA1/2 mutations from a South American population. RESULTS: We evaluated the association of five SNPs with BC risk in 440 cases and 807 controls. Our data do not support an association of rs11614913:C > T and rs4919510:C > G with BC risk. The rs6505162:C > A was significantly associated with increased risk of familial BC in persons with a strong family history of BC (OR = 1.7 [95 % CI 1.0-2.0] p = 0.05). The rs2682818:C > A genotype C/A is associated with an increased BC risk in non-familial early-onset BC. For the rs895819:A > G polymorphism, the genotype G/G is significantly associated with reduced BC risk in families with a moderate history of BC (OR = 0.3 [95 % CI 0.1-0.8] p = 0.01). CONCLUSIONS: The contribution of variant miRNA genes to BC in South American women had been unexplored. Our findings support the following conclusions: a) rs6505162:C > A in pre-miR-423 increases risk of familial BC in families with a strong history of BC; b) the C/A genotype at rs2682818:C > A (pre-miR-618) increases BC risk in non-familial early-onset BC; and c) the G/G genotype at rs895819:A > G (miR-27a) reduces BC risk in families with a moderate history of BC.


Assuntos
Neoplasias da Mama/genética , Predisposição Genética para Doença/genética , MicroRNAs/genética , Polimorfismo de Nucleotídeo Único , Precursores de RNA/genética , Feminino , Frequência do Gene , Humanos , Pessoa de Meia-Idade , Mutação , América do Sul
7.
BMC Cancer ; 15: 30, 2015 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-25636233

RESUMO

BACKGROUND: Germline mutations in PALB2 have been identified in approximately 1% of familial breast cancer (BC) in several populations. Nevertheless its contribution in the South-American population is unknown. The goal of this study was to determine the prevalence of PALB2 mutations in the Chilean population. METHODS: 100 Chilean BRCA1/2-negatives familial BC cases were included for the PALB2 mutation analysis. We use conformational sensitive gel electrophoresis and direct sequencing. Using a case-control design, we studied the identified variants in 436 BC cases and 809 controls to evaluate their possible association with BC risk. RESULTS: No pathogenic mutations were detected. We identified three variants, the variant c.1861C > A not previously described was found in one of the 436 cases and none of the 809 controls. The bioinformatic analyses indicate that this variant probably is not pathogenic. PALB2 c.1676A > G (rs152451A/G) and c.2993C > T (rs45551636C/T) variants were significantly associated with increased BC risk only in cases with a strong family history of BC (OR = 1.9 [CI 95% 1.3-2.8] p < 0.01 and OR = 3.3 [CI 95% 1.4-7.3] p < 0.01, respectively). The rs152451A/G-rs45551636C/T composite genotype produce increase of the BC risk in cases with a strong family history of BC (OR = 3.6 [CI 95% 1.7-8.0] p = 0.003). The rs152451-G/rs45551636-C and rs152451-G/rs45551636-T haplotypes were associated with an increased BC risk only in cases with a strong family history of BC (OR = 1.6 [CI 95% 1.0-2.5] p = 0.05 and OR = 3.7 [CI 95% 1.8-7.5] p < 0.001, respectively). CONCLUSION: Our results suggest that PALB2 c.1676A > G and c.2993C > T play roles in BC risk in women with a strong family history of BC.


Assuntos
Predisposição Genética para Doença , Variação Genética , Proteínas Nucleares/genética , Proteínas Supressoras de Tumor/genética , Adulto , Idade de Início , Alelos , Neoplasias da Mama/epidemiologia , Neoplasias da Mama/genética , Estudos de Casos e Controles , Chile/epidemiologia , Biologia Computacional , Análise Mutacional de DNA , Proteína do Grupo de Complementação N da Anemia de Fanconi , Feminino , Frequência do Gene , Genótipo , Haplótipos , Humanos , Pessoa de Meia-Idade , Mutação , Vigilância da População , Prevalência , Risco , Adulto Jovem
8.
Mol Biol Rep ; 41(6): 3715-22, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24532140

RESUMO

Recent Genome-Wide Association Studies have identified several single nucleotide polymorphisms (SNPs) associated with breast cancer (BC) among women of Asian, European, and African-American ancestry. Nevertheless, the contribution of these variants in the South American population is unknown. Furthermore, there is little information about the effect of these risk alleles in women with early BC diagnosis. In the present study, we evaluated the association between rs3803662 (TOX3, also known as TNRC9), rs13387042 (2q35), and rs13281615 (8q24) with BC risk in 344 Chilean BRCA1/2-negative BC cases and in 801 controls. Two SNPs, rs3803662 and rs13387042, were significantly associated with increased BC risk in familial BC and in non-familial early-onset BC. The risk of BC increased in a dose-dependent manner with the number of risk alleles (P-trend < 0.0001 and 0.0091, respectively). The odds ratios for BC in familial BC and in early-onset non-familial BC were 3.76 (95%CI 1.02-13.84, P = 0.046) and 8.0 (95%CI 2.20-29.04, P = 0.002), respectively, for the maximum versus minimum number of risk alleles. These results indicate an additive effect of the TOX3 rs3803662 and 2q35 rs13387042 alleles for BC risk. We also evaluated the interaction between rs3803662 and rs13387042 SNPs. We observed an additive interaction only in non-familial early-onset BC cases (AP = 0.72 (0.28-1.16), P = 0.001). No significant association was observed for rs13281615 (8q24) with BC risk in women from the Chilean population. The strongly increased risk associated with the combination of low-penetrance risk alleles supports the polygenic inheritance model of BC.


Assuntos
Estudos de Associação Genética , Polimorfismo de Nucleotídeo Único/genética , Receptores de Progesterona/genética , Idade de Início , Idoso , Idoso de 80 Anos ou mais , Alelos , Proteínas Reguladoras de Apoptose , Neoplasias da Mama/genética , Cromossomos Humanos Par 2/genética , Cromossomos Humanos Par 8/genética , Feminino , Predisposição Genética para Doença , Proteínas de Grupo de Alta Mobilidade , Humanos , Pessoa de Meia-Idade , América do Sul , Transativadores
9.
J Acoust Soc Am ; 134(5): 3663-73, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24180777

RESUMO

Theoretical and experimental results are presented into the sound absorption and transmission properties of multi-layer structures made up of thin micro-perforated panels (ML-MPPs). The objective is to improve both the absorption and insulation performances of ML-MPPs through impedance boundary optimization. A fully coupled modal formulation is introduced that predicts the effect of the structural resonances onto the normal incidence absorption coefficient and transmission loss of ML-MPPs. This model is assessed against standing wave tube measurements and simulations based on impedance translation method for two double-layer MPP configurations of relevance in building acoustics and aeronautics. Optimal impedance relationships are proposed that ensure simultaneous maximization of both the absorption and the transmission loss under normal incidence. Exhaustive optimization of the double-layer MPPs is performed to assess the absorption and/or transmission performances with respect to the impedance criterion. It is investigated how the panel volumetric resonances modify the excess dissipation that can be achieved from non-modal optimization of ML-MPPs.


Assuntos
Acústica/instrumentação , Materiais de Construção , Arquitetura de Instituições de Saúde/instrumentação , Ruído/prevenção & controle , Simulação por Computador , Desenho de Equipamento , Arquitetura de Instituições de Saúde/métodos , Modelos Teóricos , Movimento (Física) , Análise Numérica Assistida por Computador , Porosidade , Reprodutibilidade dos Testes
10.
Endocrinol Nutr ; 60(9): 495-503, 2013 Nov.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-24094451

RESUMO

BACKGROUND AND OBJECTIVE: Thyroglobulin in the needle washout (Tg-FNA) and cytology of fine needle aspiration (cyto-FNA) are recommended for diagnosis of metastatic lymphadenopathies and recurrence of differentiated thyroid cancer. The objective of this study was to assess the value of these procedures in 16 cervical masses from patients with thyroid cancer of the follicular epithelium (TC). PATIENTS AND METHODS: The study included six patients with TC and cervical lymphadenopathies evaluated before initial thyroid surgery and 10 patients followed up after TC surgery with cervical lumps discovered. FNA was performed in all 16 masses. Results of cyto-FNA, Tg-FNA and of the combined tests were compared to the final diagnosis of each lesion. RESULTS: Among 10 lesions proven to be malignant at surgery, cyto-FNA, Tg-FNA and the combination of both allowed for adequate diagnosis in 7, 9, and 10 cases respectively. Among 6 lesions considered to be benign, cyto-FNA was able to confirm diagnosis in 4, was non-diagnostic in one, and was falsely negative in the remaining case, while Tg-FNA was below the established cut-off value (to consider malignancy) in all cases. CONCLUSIONS: In patients with TC and suspect cervical masses, Tg-FNA improved the diagnostic yield of cyto-FNA alone, thus warranting its routine recommendation when FNA is performed. However, universal standardization of the technique and definition of valid cut-off thyroglobulin values (depending on the immunoassay used) above which the lesion should be considered to be malignant are still pending.


Assuntos
Líquidos Corporais/química , Tireoglobulina/análise , Neoplasias da Glândula Tireoide/química , Neoplasias da Glândula Tireoide/patologia , Biópsia por Agulha Fina , Humanos , Pescoço
11.
Breast Cancer Res Treat ; 137(2): 559-69, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23225170

RESUMO

Genome-Wide Association Studies have identified several loci associated with breast cancer (BC) in populations of different ethnic origins. One of the strongest associations was found in the FGFR2 gene, and MAP3K1 has been proposed as a low-penetrance BC risk factor. In this study, we evaluated the associations among FGFR2 SNPs rs2981582, rs2420946, and rs1219648; and MAP3K1 rs889312, with BC risk in 351 BRCA1/2-negative Chilean BC cases and 802 controls. All the SNPs studied were significantly associated with increased BC risk in familial BC and in non-familial early-onset BC, in a dose-dependent manner. Subjects with 3 risk alleles were at a significantly increased risk of BC compared with subjects with 0-2 risk alleles, in both familial BC and early-onset non-familial BC (OR = 1.47, 95 % CI 1.04-2.07, P = 0.026 and OR = 2.04 95 % CI 1.32-3.24, P < 0.001, respectively). In the haplotype analysis, the FGFR2 rs2981582 T / rs2420946 T / rs1219648 G haplotype (ht2) was associated with a significantly increased BC risk compared with the rs2981582 C / rs2420946 C / rs1219648 A haplotype in familial BC and in non-familial early-onset BC (OR = 1.32, 95 % CI 1.06-1.65, P = 0.012; OR = 1.46, 95 % CI 1.11-1.91, P = 0.004, respectively). When the FGFR2 ht2 and MAP3K1 rs889312 were evaluated as risk alleles, the risk of BC increased in a dose-dependent manner as the number of risk alleles increased (P trend <0.0001), indicating an additive effect. Nevertheless, there is no evidence of an interaction between FGFR2 ht2 and the MAP3K1 rs889312 C allele. These findings suggest that genetic variants in the FGFR2 and MAP3K1 genes may contribute to genetic susceptibility to BC.


Assuntos
Neoplasias da Mama/genética , Predisposição Genética para Doença , MAP Quinase Quinase Quinase 1/genética , Polimorfismo de Nucleotídeo Único , Receptor Tipo 2 de Fator de Crescimento de Fibroblastos/genética , Adulto , Idade de Início , Neoplasias da Mama/epidemiologia , Estudos de Casos e Controles , Chile/epidemiologia , Família , Feminino , Frequência do Gene , Haplótipos/genética , Humanos , Desequilíbrio de Ligação
12.
J Acoust Soc Am ; 132(2): 789-98, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22894201

RESUMO

This paper presents theoretical and experimental results on the influence of panel vibrations on the sound absorption properties of thin micro-perforated panel absorbers (MPPA). Measurements show that the absorption performance of thin MPPAs generates extra absorption peaks or dips that cannot be understood assuming a rigid MPPA. A theoretical model is established that accounts for structural-acoustic interaction between the micro-perforated panel and the backing cavity, assuming uniform conservative boundary conditions for the panel and separable coordinates for the cavity cross-section. This model is verified experimentally against impedance tube measurements and laser vibrometric scans of the cavity-backed panel response. It is shown analytically and experimentally that the air-frame relative velocity is a key factor that alters the input acoustic impedance of thin MPPAs. Coupled mode analysis reveals that the two first resonances of an elastic MPPA are either panel-cavity, hole-cavity, or panel-controlled resonances, depending on whether the effective air mass of the perforations is greater or lower than the first panel modal mass. A critical value of the perforation ratio is found through which the MPPA resonances experience a frequency "jump" and that determines two absorption mechanisms operating out of the transitional region.


Assuntos
Acústica/instrumentação , Materiais de Construção , Arquitetura de Instituições de Saúde/instrumentação , Ruído/prevenção & controle , Absorção , Ar , Desenho de Equipamento , Modelos Teóricos , Movimento (Física) , Porosidade , Pressão , Reprodutibilidade dos Testes , Vibração
13.
Mol Biol Rep ; 39(8): 8091-8, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22544576

RESUMO

Since the discovery of the BRCA1 and BRCA2 genes, much work has been carried out to identify further breast cancer (BC) susceptibility genes. BARD1 (BRCA1-associated ring domain) was originally identified as a BRCA1-interacting protein but has also been described in tumor-suppressive functions independent of BRCA1. Some association studies have suggested that the BARD1 Cys557Ser variant might be associated with increased risk of BC, but others have failed to confirm this finding. To date, this variant has not been analyzed in Spanish or South-American populations. In this study, using a case-control design, we analyzed the C-terminal Cys557Ser change in 322 Chilean BC cases with no mutations in BRCA1 or BRCA2 and in 570 controls in order to evaluate its possible association with BC susceptibility. BARD1 Cys557Ser was associated with an increased BC risk (P = 0.04, OR = 3.4 [95 % CI 1.2-10.2]) among cases belonging to families with a strong family history of BC. No difference between single cases affected with age <50 years at diagnosis (n = 117) and controls was observed for carriers of Cys/Ser genotype. It is likely that this variant is not involved in BC risk in this group of women. We also analyzed a possible interaction between BARD1 557Ser/XRCC3 241Met variants considering the role of both genes in the maintenance of genome integrity. The combined genotype Cys/Ser-carrier with the XRCC3 241Met allele was associated with an increased BC risk (P = 0.02, OR = 5.01 [95 % CI 1.36-18.5]) among women belonging to families with at least three BC and/or ovarian cancer cases. Our results suggest that BARD1 557Ser and XRCC3 241Met may play roles in BC risk in women with a strong family history of BC. Nevertheless there is no evidence of an interaction between the two SNPs. These findings should be confirmed by other studies and in other populations.


Assuntos
Neoplasias da Mama/genética , Predisposição Genética para Doença , Polimorfismo de Nucleotídeo Único , Proteínas Supressoras de Tumor/genética , Ubiquitina-Proteína Ligases/genética , Adulto , Alelos , Estudos de Casos e Controles , Chile , Proteínas de Ligação a DNA/genética , Família , Feminino , Frequência do Gene , Genótipo , Humanos , Pessoa de Meia-Idade
14.
J Acoust Soc Am ; 131(5): 3853-63, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22559361

RESUMO

This paper describes theoretical and experimental investigations into the sound absorption and transmission properties of micro-perforated panels (MPP) backed by an air cavity and a thin plate. A fully coupled modal approach is proposed to calculate the absorption coefficient and the transmission loss of finite-sized micro-perforated panels-cavity-panel (MPPCP) partitions with conservative boundary conditions. It is validated against infinite partition models and experimental data. A practical methodology is proposed using collocated pressure-velocity sensors to evaluate in an anechoic environment the transmission and absorption properties of conventional MPPCPs. Results show under which conditions edge scattering effects should be accounted for at low frequencies. Coupled mode analysis is also performed and analytical approximations are derived from the resonance frequencies and mode shapes of a flexible MPPCP. It is found that the Helmholtz-type resonance frequency is deduced from the one associated to the rigidly backed MPPCP absorber shifted up by the mass-air mass resonance of the flexible non-perforated double-panel. Moreover, it is shown analytically and experimentally that the absorption mechanisms at the resonances are governed by a large air-frame relative velocity over the MPP surface, with either in-phase or out-of-phase relationships, depending on the MPPCP parameters.

16.
J Acoust Soc Am ; 129(1): 143-53, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21302997

RESUMO

Random wall-pressure fluctuations due to the turbulent boundary layer (TBL) are a feature of the air flow over an aircraft fuselage under cruise conditions, creating undesirable effects such as cabin noise annoyance. In order to test potential solutions to reduce the TBL-induced noise, a cost-efficient alternative to in-flight or wind-tunnel measurements involves the laboratory simulation of the response of aircraft sidewalls to high-speed subsonic TBL excitation. Previously published work has shown that TBL simulation using a near-field array of loudspeakers is only feasible in the low frequency range due to the rapid decay of the spanwise correlation length with frequency. This paper demonstrates through theoretical criteria how the wavenumber filtering capabilities of the radiating panel reduces the number of sources required, thus dramatically enlarging the frequency range over which the response of the TBL-excited panel is accurately reproduced. Experimental synthesis of the panel response to high-speed TBL excitation is found to be feasible over the hydrodynamic coincidence frequency range using a reduced set of near-field loudspeakers driven by optimal signals. Effective methodologies are proposed for an accurate reproduction of the TBL-induced sound power radiated by the panel into a free-field and when coupled to a cavity.


Assuntos
Acústica , Aeronaves , Modelos Teóricos , Ruído dos Transportes/prevenção & controle , Acústica/instrumentação , Alumínio , Simulação por Computador , Movimento (Física) , Análise Numérica Assistida por Computador , Pressão , Espectrografia do Som , Fatores de Tempo , Transdutores , Vibração
17.
Breast Cancer Res Treat ; 126(3): 705-16, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20859677

RESUMO

The distribution of BRCA1/2 germline mutations in breast/ovarian cancer (BC/OC) families varies among different populations. In the Chilean population, there are only two reports of mutation analysis of BRCA1/2, and these included a low number of BC and/or OC patients. Moreover, the prevalence of BRCA1/2 genomic rearrangements in Chilean and in other South American populations is unknown. In this article, we present the mutation-detection data corresponding to a set of 326 high-risk families analyzed by conformation-sensitive gel electrophoresis and heteroduplex analysis. To determine the contribution of BRCA1/2 LGRs in Chilean BC patients, we analyzed 56 high-risk subjects with no pathogenic BRCA1/2 point mutations. Germline BRCA1/2 point mutations were found in 23 (7.1%) of the 326 Chilean families. Families which had at least three BC and/or OC cases showed the highest frequency of mutations (15.9%). We identified 14 point pathogenic mutations. Three recurrent mutations in BRCA1 (c.187_188delAG, c.2605_2606delTT, and c.3450_3453delCAAG) and three in BRCA2 (c.4969_4970insTG, c.5374_5377delTATG, and c.6503_6504delTT) contributed to 63.6 and 66.7% of all the deleterious mutations of each gene, which may reflect the presence of region-specific founder effects. Taken together BRCA1/2 recurrent point mutations account for 65.2% (15/23) of the BRCA1/2 (+) families. No large deletions or duplications involving BRCA1/2 were identified in a subgroup of 56 index cases negative for BRCA1/2 point mutations. Our study, which is the largest conducted to date in a South American population, provides a comprehensive analysis on the type and distribution of BRCA1/2 mutations and allelic variants.


Assuntos
Neoplasias da Mama Masculina/genética , Neoplasias da Mama/genética , Genes BRCA1 , Genes BRCA2 , Neoplasias Ovarianas/genética , Mutação Puntual , Adulto , Chile , Éxons , Saúde da Família , Feminino , Efeito Fundador , Rearranjo Gênico , Humanos , Íntrons , Masculino , Pessoa de Meia-Idade , Risco
18.
J Acoust Soc Am ; 127(6): 3538-47, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20550254

RESUMO

The characterization of in-duct acoustic source parameters for their use at the design stage, in virtual prototyping of the noise induced by fans and obstacles, is of great engineering importance. Conventional inverse approaches, such as the equivalent source method, offer accurate reconstruction results, but they require a large number of virtual sources or a suitable location of a few number of them. This paper proposes an alternative method that provides a cross-sectional imaging of the amplitude distribution of ducted sources, which does not depend on a prior adequate placement of equivalent sources, or on the degree of correlation between the real ones. The method is based on a full spectral formulation of the inverse problem, from which a theoretical stopping criterion is derived that provides a stable reconstruction of the unknown source distribution. Accurate and well-resolved imaging results of the axial acoustic velocity generated by wall-mounted drivers are obtained from either in-duct or wall-pressure measurements, acquired respectively without or with flow. The accuracy and the resolution of the retrieved source strength are significantly enhanced from an iterative modal decomposition of the pressure field, when imaging from data acquired respectively at large or small standoff distances to the source plane.

19.
Breast Cancer Res Treat ; 122(3): 813-22, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20054644

RESUMO

The double-strand break (DSB) DNA repair pathway has been implicated in breast cancer (BC). RAD51 and its paralogs XRCC3 and RAD51D play an important role in the repair of DSB through homologous recombination (HR). Some polymorphisms including XRCC3-Thr241Met, RAD51-135G>C, and RAD51D-E233G have been found to confer increased BC susceptibility. In order to detect novel mutations that may contribute to BC susceptibility, 150 patients belonging to 150 Chilean BRCA1/2-negative families were screened for mutations in XRCC3. No mutations were detected in the XRCC3 gene. In addition, using a case-control design we studied the XRCC3-Thr241Met, and RAD51D-E233G polymorphisms in 267 BC cases and 500 controls to evaluate their possible association with BC susceptibility. The XRCC3 Met/Met genotype was associated with an increased BC risk (P = 0.003, OR = 2.44 [95%CI 1.34-4.43]). We did not find an association between E233G polymorphism and BC risk. We also analyzed the effect of combined genotypes among RAD51-135G>C, Thr241Met, and E233G polymorphisms on BC risk. No interaction was observed between Thr241Met and 135G>C. The combined genotype Thr/Met-E/G was associated with an increased BC risk among women who (a) have a family history of BC, (b) are BRCA1/2-negative, and (c) were <50 years at onset (n = 195) (P = 0.037, OR = 10.5 [95%CI 1.16-94.5]). Our results suggested that the variability of the DNA HR repair genes XRCC3 and RAD51D may play a role in BC risk, but this role may be underlined by a mutual interaction between these genes. These findings should be confirmed in other populations.


Assuntos
Neoplasias da Mama/genética , Quebras de DNA de Cadeia Dupla , Reparo do DNA/genética , Proteínas de Ligação a DNA/genética , Polimorfismo Genético/genética , Adulto , Idoso , Neoplasias da Mama/epidemiologia , Estudos de Casos e Controles , Análise Mutacional de DNA , Feminino , Predisposição Genética para Doença , Genótipo , Humanos , Pessoa de Meia-Idade , Prognóstico , Fatores de Risco , América do Sul/epidemiologia
20.
Endocrinol Nutr ; 56(3): 140-2, 2009 Mar.
Artigo em Espanhol | MEDLINE | ID: mdl-19627728
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