Irreversible time-dependent rheological behavior of cement slurries : constitutive model and experiments

Over the last few decades, much focus has been given to investigating the reversible rheological behavior of thixotropic materials, but the description of the rheology of materials undergoing an irreversible process is still challenging. In this work, the time-dependent rheological behavior of a cement slurry is investigated. Different rheometric experiments are performed to evaluate the structure breakdown under shear, cement gelation, and curing process. A recently proposed thixotropic elasto-viscoplastic model [de Souza Mendes, Soft Matter 7, 2471-2483 (2011)] is modified to account for irreversible effects, which can be either of a chemical or physical nature, making the current model capable of describing reversible and irreversible processes with a single structure parameter. The parameters of the model are estimated from constant shear rate tests and from the flow curve of the fresh cement slurry. The model predictions are compared to step-down and step-up in stress experiments, and the results show that the model successfully describes experimental data obtained. Interesting phenomena are observed and discussed, including (i) thixotropic behavior during the dormant period, (ii) shear banding, (iii) irreversible changes in cement slurry rheology after the hydration reactions accelerate, and (iv) the existence of a characteristic time for the transition from a thixotropic-yield-stress material to a solid during curing. The predictive capability of the new model includes bifurcation, shear banding, stress overshoots, effects of chemical reactions, and irreversible shear degradation. It is argued that the ideas employed in the present work can be used to incorporate irreversible effects into other thixotropic models, giving rise to the possibility of describing the transient rheological behavior of complex materials in an unprecedented fashion. (c) 2019 The Society of Rheology

A feasibility study with survival in swine model

Transrectal access still has some unsolved issues such as spatial orientation, infection, access and site closure. This study presents a simple technique to perform transcolonic access with survival in a swine model series. A new technique for NOTES perirectal access to perform retroperitoneoscopy, peritoneoscopy, liver and lymphnode biopsies was performed in 6 pigs, using Totally NOTES technique. The specimens were extracted transanally. The flexible endoscope was inserted through a posterior transmural incision and the retrorectal space. Cultures of bacteria were documented for the retroperitoneal space and intra abdominal cavity after 14 days. Rectal site was closed using non-absorbable sutures. There was no bowel cleansing, nor preoperative fasting. The procedures were performed in 6 pigs through transcolonic natural orifice access using available endoscopic flexible instruments. All animals survived 14 days without complications, and cultures were negative. Histopathologic examination of the rectal closure site showed adequate healing of suture line and no micro abscesses. The results of feasibility and safety of experimental Transcolonic NOTES potentially brings new frontiers and future wider applications for minimally invasive surgery. The treatment of colorectal, abdominal and retroperitoneal diseases through a flexible Perirectal NOTES Access (PNA) is a promising new approach

Using multi-criteria analysis for smart city assessment

Urban centers have been under a new concept of city. Smart Cities are, in a nutshell, organized communities that feature high communication technology and conscious investments in sustainability, providing dynamic and safe environments. This paper presents a methodology to assess and rank Smart Cities based on a multi-criteria decision-making process. Methodologies that do not consider a pondered approach and filter for specific goals are commonly found in the literature, once there is a great number of criteria involved in these analyses. This work proposes filtering the criteria, considering each specific evaluation and its objectives. Our methodology is based on a multi-criteria analysis and uses AHP (Analytic Hierarchy Process) to support the process of weights definition and MACBAC (Multi-Attributive Border Approximation Area Comparison) in an application with compensatory characteristics. Through this study, it is possible to conduct the assessment of Smart Cities according to its multiple contexts, viz. its location, decision-makers and the objectives of the analysis. All in all, this research presents novelty related to the organization of the evaluation in accord to the expected resolution and a pondered approach with reduced number of criteria, making the analysis very straightforward.publicad

Exposure to magnetic fields and childhood acute lymphocytic leukemia in São Paulo, Brazil

Background: Epidemiological studies have identified increased risks of leukemia in children living near power lines and exposed to relatively high levels of magnetic fields. Results have been remarkably consistent, but there is still no explanation for this increase. in this study we evaluated the effect of 60 Hz magnetic fields on acute lymphocytic leukemia (ALL) in the State of São Paulo, Brazil. Methods: This case-control study included ALL cases (n = 162) recruited from eight hospitals between January 2003 and February 2009. Controls (n = 565) matched on gender, age, and city of birth were selected from the São Paulo Birth Registry. Exposure to extremely low frequency magnetic fields (ELF MF) was based on measurements inside home and distance to power lines. Results: for 24 h measurements in children rooms, levels of ELF MF equal to or greater than 0.3 microtesla (mu T), compared to children exposed to levels below 0.1 mu T showed no increased risk of ALL (odds ratio [OR] 1.09; 95% confidence interval [95% CI] 0.33-3.61). When only nighttime measurements were considered, a risk (OR 1.52; 95% CI 0.46-5.01) was observed. Children living within 200 m of power lines presented an increased risk of ALL (OR 1.67; 95% CI 0.49-5.75), compared to children living at 600 m or more of power lines. for those living within 50 m of power lines the OR was 3.57 (95% CI 0.41-31.44). Conclusions: Even though our results are consistent with the small risks reported in other studies on ELF MF and leukemia in children, overall our results do not provide support for an association between magnetic fields and childhood leukemia, but small numbers and likely biases weaken the strength of this conclusion. (C) 2011 Elsevier B.V. All rights reserved.Univ São Paulo, Fac Saude Publ, Dept Epidemiol, BR-01255 São Paulo, BrazilAssoc Brasileira Compatibilidade Eletromagnet, São Paulo, BrazilHosp Amaral Carvalho, Jau, BrazilUniv São Paulo, Fac Med, BR-14049 Ribeirao Preto, BrazilUniversidade Federal de São Paulo, Inst Oncol Pediat, São Paulo, BrazilHosp Infantil Darcy Vargas, São Paulo, BrazilSanta Casa Misericordia São Paulo, São Paulo, BrazilHosp Santa Marcelina, São Paulo, BrazilUniv Calif Los Angeles, Sch Publ Hlth, Los Angeles, CA 90024 USAUniversidade Federal de São Paulo, Inst Oncol Pediat, São Paulo, BrazilWeb of Scienc

Reproductive tract size and position score: Estimation of genetic parameters for a novel fertility trait in dairy cows.

The dairy industry is moving toward selecting animals with better fertility to decrease the economic losses linked to reproductive issues. The reproductive tract size and position score (SPS) was recently developed in physiological studies as an indicator of pregnancy rate and the number of services to conception. Cows are scored as SPS 1, 2, or 3 based on the size of their reproductive tract and its position in the pelvis, as determined by transrectal palpation. The objective of this study was to estimate genetic parameters for SPS to assess its potential as a novel fertility trait. Phenotypes were collected at the University of British Columbia's research herd from 2017 to 2020, consisting of 3,247 within- and across-lactation SPS records from 490 Holstein cows. A univariate animal model was used to estimate the variance components for SPS. Both threshold and linear models were fit under a Bayesian approach and the results were compared using the Spearman rank correlation (r) between the estimated breeding values. The 2 models ranked the animals very similarly (r = 0.99), and the linear model was selected for further analysis. Genetic correlations with other currently evaluated traits were estimated using a bivariate animal model. The posterior means (± posterior standard deviation) for heritability and repeatability within- and across-lactation were 0.113 (± 0.013), 0.242 (± 0.012), and 0.134 (± 0.014), respectively. The SPS showed null correlations with production traits and favorable correlations with traditional fertility traits, varying from -0.730 (nonreturn rate) to 0.931 (number of services). Although preliminary, these results are encouraging because SPS seems to be more heritable than and strongly genetically correlated with number of services, nonreturn rate, and first service to conception, indicating potential for effective indirect selection response on these traits from SPS genetic selection. Therefore, further studies with larger data sets to validate these findings are warranted

Expression of tyrosine kinase receptor AXL is associated with worse outcome of metastatic renal cell carcinomas treated with sunitinib

Expression of tyrosine kinase receptor AXL is associated with worse outcome of metastatic renal cell carcinomas treated with sunitinibBackground: Renal cell carcinoma (RCC) represents 2%-3% of all cancers of the Western countries. Currently, sunitinib, a receptor tyrosine kinase inhibitor, particularly of PDGF and VEGF receptors, is the first-line therapy for metastatic RCC (mRCC), with significant improvement in clinical outcome. However, there is a lack of predictive biomarkers of sunitinib response. Recently, others and our group suggested that the receptor tyrosine kinase AXL may modify the response to sunitinib. Objective: To study the expression of AXL in a series patients with of mRCC treated with sunitinib and to correlate it with patient's clinic-pathological features and therapeutic response. Material and methods: Sixty-four patients with mRCC (51 clear cell carcinomas (CCCs) and 13 non-CCCs) were evaluated for AXL expression by immunohistochemistry in the primary tumor. Results: AXL positivity was observed in 47% (30/64) of cases, namely in 43% (22/51) of CCCs and 61% (8/13) of non-CCC. Considering only the clear cell subtype, the univariate analysis showed that AXL expression was statistically associated with a poor prognosis, with a median overall survival of 13 months vs. 43 months in patients with negative AXL. In this subtype, along with the AXL positivity, other prognostic factors were absence of nephrectomy, Karnofsky performance status, more than 1 site of metastasis and liver metastasis. Moreover, AXL expression was associated with shorter progression to sunitinib. Overall, the multivariate survival analysis showed that absence of nephrectomy (HR = 4.85, P = 0.001), more than 1 site of metastasis (HR = 2.99, P = 0.002), bone metastasis (HR = 2.95, P = 0.001), together with AXL expression (HR = 2.01, P = 0.048) were independent poor prognostic factor in patients with mRCC. Conclusion: AXL expression was associated with worse clinical outcome and may be an important prognostic biomarker in sunitinibtreated patients with metastatic renal cell carcinoma.this study was supported by Barretos Cancer Hospital Internal Research Funds (PAIP) of participant authors. Rui Manuel Reis is recipient of a National Council of Technological and Scientific Development (CNPq) scholarship.info:eu-repo/semantics/publishedVersio

S-Nitroso-N-Acetylcysteine Ameliorates Ischemia-Reperfusion Injury In The Steatotic Liver

BACKGROUND: Steatosis is currently the most common chronic liver disease and it can aggravate ischemia-reperfusion (IR) lesions. We hypothesized that S-nitroso-N-acetylcysteine (SNAC), an NO donor component, can ameliorate cell damage from IR injury. In this paper, we report the effect of SNAC on liver IR in rats with normal livers compared to those with steatotic livers. METHODS: Thirty-four rats were divided into five groups: I (n=8), IR in normal liver; II (n=8), IR in normal liver with SNAC; III (n=9), IR in steatotic liver; IV (n=9), IR in steatotic liver with SNAC; and V (n=10), SHAN. Liver steatosis was achieved by administration of a protein-free diet. A SNAC solution was infused intraperitoneally for one hour, beginning 30 min. after partial (70%) liver ischemia. The volume of solution infused was 1 ml/100 g body weight. The animals were sacrificed four hours after reperfusion, and the liver and lung were removed for analysis. We assessed hepatic histology, mitochondrial respiration, oxidative stress (MDA), and pulmonary myeloperoxidase. RESULTS: All groups showed significant alterations compared with the group that received SHAN. The results from the steatotic SNAC group revealed a significant improvement in liver mitochondrial respiration and oxidative stress compared to the steatotic group without SNAC. No difference in myeloperoxidase was observed. Histological analysis revealed no difference between the non-steatotic groups. However, the SNAC groups showed less intraparenchymal hemorrhage than groups without SNAC (p=0.02). CONCLUSION: This study suggests that SNAC effectively protects against IR injury in the steatotic liver but not in the normal liver

Biomarkers for prediction of mortality in left-sided infective endocarditis

Background: Evidence regarding biomarkers for risk prediction in patients with infective endocarditis (IE) is limited. We aimed to investigate the value of a panel of biomarkers for the prediction of in-hospital mortality in patients with IE. Methods: Between 2016 and 2018, consecutive IE patients admitted to the emergency department were prospectively included. Blood concentrations of nine biomarkers were measured at admission (D0) and on the seventh day (D7) of antibiotic therapy: C-reactive protein (CRP), sensitive troponin I (s-cTnI), procalcitonin, B-type natriuretic peptide (BNP), neutrophil gelatinase-associated lipocalin (NGAL), interleukin 6 (IL6), tumor necrosis factor α (TNF-α), proadrenomedullin, alpha-1-acid glycoprotein, and galectin 3. The primary endpoint was in-hospital mortality. Results: Among 97 patients, 56% underwent cardiac surgery, and in-hospital mortality was 27%. At admission, six biomarkers were independent predictors of in-hospital mortality: s-cTnI (OR 3.4; 95%CI 1.8–6.4; P < 0.001), BNP (OR 2.7; 95%CI 1.4–5.1; P = 0.002), IL-6 (OR 2.06; 95%CI 1.3–3.7; P = 0.019), procalcitonin (OR 1.9; 95%CI 1.1–3.2; P = 0.018), TNF-α (OR 1.8; 95%CI 1.1–2.9; P = 0.019), and CRP (OR 1.8; 95%CI 1.0–3.3; P = 0.037). At admission, S-cTnI provided the highest accuracy for predicting mortality (area under the ROC curve: s-cTnI 0.812, BNP 0.727, IL-6 0.734, procalcitonin 0.684, TNF-α 0.675, CRP 0.670). After 7 days of antibiotic therapy, BNP and inflammatory biomarkers improved their performance (s-cTnI 0.814, BNP 0.823, IL-6 0.695, procalcitonin 0.802, TNF-α 0.554, CRP 0.759). Conclusion: S-cTnI concentration measured at admission had the highest accuracy for mortality prediction in patients with IE