ORIGEM E RAMIFICAÇÕES DAS ARTÉRIAS MESENTÉRICAS CRANIAL E CAUDAL EM TARTARUGA DA AMAZÔNIA Podocnemis expansa Schweigger, 1812, (Testudinata-pelomedusidae)

Foram estudadas cinco Podocnemis expansa, fêmeas, cujo peso variava de 550 a 850 g. Os animais tiveram seu sistema arterial injetado com solução corada de látex sintético, fixados e armazenados em solução aquosa de formaldeído a 10%. Após abertura da cavidade celomática, as artérias mesentéricas cranial e caudal foram dissecadas. Encontrou-se a artéria mesentérica cranial como um ramo do tronco celíaco-mesentérico e originando as artérias pancreaticoduodenal caudal, ileocólica e jejunais, que irrigam o duodeno, pâncreas, cólon, íleo e jejuno, respectivamente. A artéria mesentérica caudal origina-se da aorta (60%) ou da artéria ilíaca comum (40%), distribuindo-se para o cólon e reto. Origin and ramifications of the cranial and caudal mesenteric arteries in Amazonian turtle - Podocnemis expansa Schweigger, 1812, Testudinata-Pelomedusidae Abstract An anatomic study has been carried out on the mesenteric arteries of five Podocnemis expansa females weighing from 550 to 680 g. The animals had their artery system injected with a latex solution colored with a specific pigment and were then fixed in a 10% formol solution. After the coelomatic cavity being opened the cranial and caudal mesenteric arteries were dissected. It has been found that the cranial mesenteric artery is a branch of the coeliac mesenteric trunk while the cranial mesenteric artery gives off the pancreatic-duodenal , ileocolic and jejunal arteries that irrigate the duodenum, pancreas, colon, ileum and jejunum respectively. The aorta gives origen of as much as 60% of the caudal mesenteric artery, the remaining 40 % being originated from the common ileac artery, their branches reaching the colon and the rectum

Structural and doping effects in the half-metallic double perovskite A2A_2CrWO6_6

he structural, transport, magnetic and optical properties of the double perovskite $A_2$CrWO$_6$ with $A=\text{Sr, Ba, Ca}$ have been studied. By varying the alkaline earth ion on the $A$ site, the influence of steric effects on the Curie temperature $T_C$ and the saturation magnetization has been determined. A maximum $T_C=458$ K was found for Sr$_2$CrWO$_6$ having an almost undistorted perovskite structure with a tolerance factor $f\simeq 1$. For Ca$_2$CrWO$_6$ and Ba$_2$CrWO$_6$ structural changes result in a strong reduction of $T_C$. Our study strongly suggests that for the double perovskites in general an optimum $T_C$ is achieved only for $f \simeq 1$, that is, for an undistorted perovskite structure. Electron doping in Sr$_2$CrWO$_6$ by a partial substitution of Sr$^{2+}$ by La$^{3+}$ was found to reduce both $T_C$ and the saturation magnetization $M_s$. The reduction of $M_s$ could be attributed both to band structure effects and the Cr/W antisites induced by doping. Band structure calculations for Sr$_2$CrWO$_6$ predict an energy gap in the spin-up band, but a finite density of states for the spin-down band. The predictions of the band structure calculation are consistent with our optical measurements. Our experimental results support the presence of a kinetic energy driven mechanism in $A_2$CrWO$_6$, where ferromagnetism is stabilized by a hybridization of states of the nonmagnetic W-site positioned in between the high spin Cr-sites.Comment: 14 pages, 10 figure

Effects of accelerated versus standard care surgery on the risk of acute kidney injury in patients with a hip fracture : A substudy protocol of the hip fracture Accelerated surgical TreaTment and Care tracK (HIP ATTACK) international randomised controlled trial

Introduction Inflammation, dehydration, hypotension and bleeding may all contribute to the development of acute kidney injury (AKI). Accelerated surgery after a hip fracture can decrease the exposure time to such contributors and may reduce the risk of AKI. Methods and analysis Hip fracture Accelerated surgical TreaTment And Care tracK (HIP ATTACK) is a multicentre, international, parallel-group randomised controlled trial (RCT). Patients who suffer a hip fracture are randomly allocated to either accelerated medical assessment and surgical repair with a goal of surgery within 6 hours of diagnosis or standard care where a repair typically occurs 24 to 48 hours after diagnosis. The primary outcome of this substudy is the development of AKI within 7 days of randomisation. We anticipate at least 1998 patients will participate in this substudy. Ethics and dissemination We obtained ethics approval for additional serum creatinine recordings in consecutive patients enrolled at 70 participating centres. All patients provide consent before randomisation. We anticipate reporting substudy results by 2021. Trial registration number NCT02027896; Pre-results

Rationale and design of the hip fracture accelerated surgical treatment and care track (hip attack) trial : A protocol for an international randomised controlled trial evaluating early surgery for hip fracture patients

Introduction Annually, millions of adults suffer hip fractures. The mortality rate post a hip fracture is 7%-10% at 30 days and 10%-20% at 90 days. Observational data suggest that early surgery can improve these outcomes in hip fracture patients. We designed a clinical trial - HIP fracture Accelerated surgical TreaTment And Care tracK (HIP ATTACK) to determine the effect of accelerated surgery compared with standard care on the 90-day risk of all-cause mortality and major perioperative complications. Methods and analysis HIP ATTACK is a multicentre, international, parallel group randomised controlled trial (RCT) that will include patients ≥45 years of age and diagnosed with a hip fracture from a low-energy mechanism requiring surgery. Patients are randomised to accelerated medical assessment and surgical repair (goal within 6 h) or standard care. The co-primary outcomes are (1) all-cause mortality and (2) a composite of major perioperative complications (ie, mortality and non-fatal myocardial infarction, pulmonary embolism, pneumonia, sepsis, stroke, and life-threatening and major bleeding) at 90 days after randomisation. All patients will be followed up for a period of 1 year. We will enrol 3000 patients. Ethics and dissemination All centres had ethics approval before randomising patients. Written informed consent is required for all patients before randomisation. HIP ATTACK is the first large international trial designed to examine whether accelerated surgery can improve outcomes in patients with a hip fracture. The dissemination plan includes publishing the results in a policy-influencing journal, conference presentations, engagement of influential medical organisations, and providing public awareness through multimedia resources. Trial registration number NCT02027896; Pre-results

Rationale and design of the PeriOperative ISchemic Evaluation-3 (POISE-3): a randomized controlled trial evaluating tranexamic acid and a strategy to minimize hypotension in noncardiac surgery

Background For patients undergoing noncardiac surgery, bleeding and hypotension are frequent and associated with increased mortality and cardiovascular complications. Tranexamic acid (TXA) is an antifibrinolytic agent with the potential to reduce surgical bleeding; however, there is uncertainty about its efficacy and safety in noncardiac surgery. Although usual perioperative care is commonly consistent with a hypertension-avoidance strategy (i.e., most patients continue their antihypertensive medications throughout the perioperative period and intraoperative mean arterial pressures of 60 mmHg are commonly accepted), a hypotension-avoidance strategy may improve perioperative outcomes. Methods The PeriOperative Ischemic Evaluation (POISE)-3 Trial is a large international randomized controlled trial designed to determine if TXA is superior to placebo for the composite outcome of life-threatening, major, and critical organ bleeding, and non-inferior to placebo for the occurrence of major arterial and venous thrombotic events, at 30 days after randomization. Using a partial factorial design, POISE-3 will additionally determine the effect of a hypotension-avoidance strategy versus a hypertension-avoidance strategy on the risk of major cardiovascular events, at 30 days after randomization. The target sample size is 10,000 participants. Patients ≥45 years of age undergoing noncardiac surgery, with or at risk of cardiovascular and bleeding complications, are randomized to receive a TXA 1 g intravenous bolus or matching placebo at the start and at the end of surgery. Patients, health care providers, data collectors, outcome adjudicators, and investigators are blinded to the treatment allocation. Patients on ≥ 1 chronic antihypertensive medication are also randomized to either of the two blood pressure management strategies, which differ in the management of patient antihypertensive medications on the morning of surgery and on the first 2 days after surgery, and in the target mean arterial pressure during surgery. Outcome adjudicators are blinded to the blood pressure treatment allocation. Patients are followed up at 30 days and 1 year after randomization. Discussion Bleeding and hypotension in noncardiac surgery are common and have a substantial impact on patient prognosis. The POISE-3 trial will evaluate two interventions to determine their impact on bleeding, cardiovascular complications, and mortality.Trial registration ClinicalTrials.gov NCT03505723. Registered on 23 April 2018.Maura Marcucci, Thomas W. Painter, David Conen, Kate Leslie, Vladimir V. Lomivorotov, Daniel Sessler ... et al

Tranexamic Acid in Patients Undergoing Noncardiac Surgery

BACKGROUND Perioperative bleeding is common in patients undergoing noncardiac surgery. Tranexamic acid is an antifibrinolytic drug that may safely decrease such bleeding. METHODS We conducted a trial involving patients undergoing noncardiac surgery. Patients were randomly assigned to receive tranexamic acid (1-g intravenous bolus) or placebo at the start and end of surgery (reported here) and, with the use of a partial factorial design, a hypotension-avoidance or hypertension-avoidance strategy (not reported here). The primary efficacy outcome was life-threatening bleeding, major bleeding, or bleeding into a critical organ (composite bleeding outcome) at 30 days. The primary safety outcome was myocardial injury after noncardiac surgery, nonhemorrhagic stroke, peripheral arterial thrombosis, or symptomatic proximal venous thromboembolism (composite cardiovascular outcome) at 30 days. To establish the noninferiority of tranexamic acid to placebo for the composite cardiovascular outcome, the upper boundary of the one-sided 97.5% confidence interval for the hazard ratio had to be below 1.125, and the one-sided P value had to be less than 0.025. RESULTS A total of 9535 patients underwent randomization. A composite bleeding outcome event occurred in 433 of 4757 patients (9.1%) in the tranexamic acid group and in 561 of 4778 patients (11.7%) in the placebo group (hazard ratio, 0.76; 95% confidence interval [CI], 0.67 to 0.87; absolute difference, −2.6 percentage points; 95% CI, −3.8 to −1.4; two-sided P<0.001 for superiority). A composite cardiovascular outcome event occurred in 649 of 4581 patients (14.2%) in the tranexamic acid group and in 639 of 4601 patients (13.9%) in the placebo group (hazard ratio, 1.02; 95% CI, 0.92 to 1.14; upper boundary of the one-sided 97.5% CI, 1.14; absolute difference, 0.3 percentage points; 95% CI, −1.1 to 1.7; one-sided P = 0.04 for noninferiority). CONCLUSIONS Among patients undergoing noncardiac surgery, the incidence of the composite bleeding outcome was significantly lower with tranexamic acid than with placebo. Although the between-group difference in the composite cardiovascular outcome was small, the noninferiority of tranexamic acid was not established.P.J. Devereaux, M. Marcucci, T.W. Painter, D. Conen, V. Lomivorotov, D.I. Sessler, M.T.V. Chan, F.K. Borges, M.J. Martínez, Zapata, C.Y. Wang, D. Xavier, S.N. Ofori, M.K. Wang, S. Efremov, G. Landoni, Y.V. Kleinlugtenbelt, W. Szczeklik, D. Schmartz, A.X. Garg, T.G. Short, M. Wittmann, C.S. Meyhoff, M. Amir, D. Torres, A. Patel, E. Duceppe, K. Ruetzler, J.L. Parlow, V. Tandon, E. Fleischmann, C.A. Polanczyk, A. Lamy, S.V. Astrakov, M. Rao, W.K.K. Wu, K. Bhatt, M. de Nadal, V.V. Likhvantsev, P. Paniagua, H.J. Aguado, R.P. Whitlock, M.H. McGillion, M. Prystajecky, J. Vincent, J. Eikelboom, I. Copland, K. Balasubramanian, A. Turan, S.I. Bangdiwala, D. Stillo, P.L. Gross, T. Cafaro, P. Alfonsi, P.S. Roshanov, E.P. Belley, Côté, J. Spence, T. Richards, T. VanHelder, W. McIntyre, G. Guyatt, S. Yusuf, and K. Leslie, for the POISE-, Investigator

Hypotension-Avoidance Versus Hypertension-Avoidance Strategies in Noncardiac Surgery : An International Randomized Controlled Trial

Background: Among patients having noncardiac surgery, perioperative hemodynamic abnormalities are associated with vascular complications. Uncertainty remains about what intraoperative blood pressure to target and how to manage long-term antihypertensive medications perioperatively. Objective: To compare the effects of a hypotension-avoidance and a hypertension-avoidance strategy on major vascular complications after noncardiac surgery. Design: Partial factorial randomized trial of 2 perioperative blood pressure management strategies (reported here) and tranexamic acid versus placebo. (ClinicalTrials.gov: NCT03505723) Setting: 110 hospitals in 22 countries. Patients: 7490 patients having noncardiac surgery who were at risk for vascular complications and were receiving 1 or more long-term antihypertensive medications. Intervention: In the hypotension-avoidance strategy group, the intraoperative mean arterial pressure target was 80mm Hg or greater; before and for 2 days after surgery, renin– angiotensin–aldosterone system inhibitors were withheld and the other long-term antihypertensive medications were administered only for systolic blood pressures 130mm Hg or greater, following an algorithm. In the hypertension-avoidance strategy group, the intraoperative mean arterial pressure target was 60mm Hg or greater; all antihypertensive medications were continued before and after surgery. Measurements: The primary outcome was a composite of vascular death and nonfatal myocardial injury after noncardiac surgery, stroke, and cardiac arrest at 30 days. Outcome adjudicators were masked to treatment assignment. Results: The primary outcome occurred in 520 of 3742 patients (13.9%) in the hypotension-avoidance group and in 524 of 3748 patients (14.0%) in the hypertension-avoidance group (hazard ratio, 0.99 [95% CI, 0.88 to 1.12]; P =0.92). Results were consistent for patients who used 1 or more than 1 antihypertensive medication in the long term. Limitation: Adherence to the assigned strategies was suboptimal; however, results were consistent across different adherence levels. Conclusion: In patients having noncardiac surgery, our hypotension-avoidance and hypertension-avoidance strategies resulted in a similar incidence of major vascular complications.Maura Marcucci, Thomas W. Painter, David Conen, Vladimir Lomivorotov, Daniel I. Sessler, Matthew T.V. Chan, Flavia K. Borges, Kate Leslie, Emmanuelle Duceppe, María Jose Martínez-Zapata, Chew Yin Wang, Denis Xavier, Sandra N. Ofori, Michael Ke Wang, Sergey Efremov, Giovanni Landoni, Ydo V. Kleinlugtenbelt, Wojciech Szczeklik, Denis Schmartz, Amit X. Garg, Timothy G. Short, Maria Wittmann, Christian S. Meyhoff, Mohammed Amir, David Torres, Ameen Patel, Kurt Ruetzler, Joel L. Parlow, Vikas Tandon, Edith Fleischmann, Carisi A. Polanczyk, Andre Lamy, Raja Jayaram, Sergey V. Astrakov, William Ka Kei Wu, Chao Chia Cheong, Sabry Ayad, Mikhail Kirov, Miriam de Nadal, Valery V. Likhvantsev, Pilar Paniagua, Hector J. Aguado, Kamal Maheshwari, Richard P. Whitlock, Michael H. McGillion, Jessica Vincent, Ingrid Copland, Kumar Balasubramanian, Bruce M. Biccard, Sadeesh Srinathan, Samandar Ismoilov, Shirley Pettit, David Stillo, Andrea Kurz, Emilie P. Belley-Côte, Jessica Spence, William F. McIntyre, Shrikant I. Bangdiwala, Gordon Guyatt, Salim Yusuf, and P.J. Devereaux, on behalf of the POISE-3 Trial Investigators and Study Group

Variabilidade da água disponível de uma terra roxa estruturada latossólica Available soil-water variability of a "terra roxa estruturada latossólica" (rhodic kanhapludalf)

A partir de 250 curvas de retenção da água no solo, elaboradas com amostras indeformadas coletadas de uma área de 6250 m² de uma Terra Roxa Estruturada Latossólica de Piracicaba,SP, foram calculados quatro conjuntos de valores de água disponível assumindo-se -1x10³, -6x10³, -1x10(4) e -3x10(4) Pa como possíveis valores de potencial mátrico correspondentes à capacidade de campo e -1,5x10³ Pa um possível valor correspondente ao ponto de murchamento permanente. Foram feitas medidas de posição (média), variabilidade (coeficiente de variação, assimetria e curtose) e numero necessário de amostras para estimar a média a um dado nível de probabilidade a fim de quantificar a variabilidade e a sensibilidade dos resultados em cada conjunto e entre conjuntos de valores de água disponível. A análise dos resultados mostrou que a variabilidade da água disponível, obtida à partir de dois valores de umidade da Curva de Retenção é muito maior que a variabilidade de cada valor individualmente. Ou seja, embora as variáveis envolvidas possam ser as mesmas, o grau de variabilidade (expresso, por exemplo, pelo coeficiente de variação) ou a sensibilidade das medidas (expressa pelo número necessário de amostras para estimar a média dentro de um determinado intervalo de confiança) pode ser bem distinto, indicando que nem sempre resultados de uma amostragem realizada com determinado objetivo poderá servir a outros, embora possam tratar-se de variáveis dependentes.<br>From 250 soil-water retention curves of an area of 6250 m² of a "Terra Roxa Estruturada Latossólica" (Rhodic Kanhapludalf) located in Piracicaba,SP, four sets of available soil-water were calculated assuming field capacity values based on soil-water contents corresponding to -1x10³, -6x10³, -1x10(4) and -3x10(4) Pa of soil water matric potential; and permanent wilting point based on soil-water contents corresponding to -1,5x10(6) Pa. Aiming to quantify the variability and the sensibility of the results for each set and among sets of soil available water values, the following calculations were made: position measurement (mean), variability (coefficient of variation, assimetry and kurtosis) and the necessary number of samples to estimate the mean at a specific probability level. The analysis of the results has shown that the variability of available soil-water values is much greater than the variability of field capacity and of permanent wilting point values used in the calculation. That is, even though the envolved variables can be the same, the degree of variability (expressed by the necessary number of samples needed to estimate the mean within a choosen interval confidence) can be very distinct, indicating that the results of a sampling, carried out for one specific objective can not always be used for another objective, even being dependent variables