Imaging Hepatocellular Carcinoma With 68Ga-Citrate PET: First Clinical Experience.

While cross-sectional imaging with computed tomography (CT) and magnetic resonance imaging is the primary method for diagnosing hepatocellular carcinoma (HCC), they provide little biological insight into this molecularly heterogeneous disease. Nuclear imaging tools that can detect molecular subsets of tumors could greatly improve diagnosis and management of HCC. To this end, we conducted a patient study to determine whether HCC can be resolved using 68Ga-citrate positron emission tomography (PET). One patient with recurrent HCC was injected with 300 MBq of 68Ga-citrate and imaged with PET/CT 249 minutes post injection. Four (28%) of 14 hepatic lesions were avid for 68Ga-citrate. One extrahepatic lesion was not PET avid. The average maximum standardized uptake value (SUVmax) for the lesions was 7.2 (range: 6.2-8.4), while the SUVmax of the normal liver parenchyma was 4.7 and blood pool was 5.7. The avid lesions were not significantly larger than the quiescent lesions, and a prior contrast CT showed uniform enhancement among the lesions, suggesting that tumor signals are due to specific binding of the radiotracer to the transferrin receptor, rather than enhanced vascularity in the tumor microenvironment. Further studies are required in a larger patient cohort to verify the molecular basis of radiotracer uptake and the clinical utility of this tool

Repair of Thoracic and Thoracoabdominal Mycotic Aneurysms and Infected Aortic Grafts Using Allograft

Background Mycotic aneurysm of the thoracic or thoracoabdominal aorta and infection of thoracic or thoracoabdominal aortic grafts are challenging problems with high mortality. In-situ reconstruction with cryopreserved allograft(CPA) avoids placement of prosthetic material in an infected field and avoids suppressive antibiotics or autologous tissue coverage. Methods Fifty consecutive patients with infection of a thoracic or thoracoabdominal aortic graft or mycotic aneurysm underwent resection and replacement with CPA from 2006 to 2016. Intravenous antibiotics were continued postoperatively for 6 weeks. Long-term suppressive antibiotics were uncommonly used (8 patients). Follow up imaging occurred at 6, 18 and 42 months postoperatively. Initial follow up was 93% complete. Results Males comprised 64% of the cohort. The mean age was 63±14 years. The procedures performed included reoperations in 37, replacement of the aortic root, ascending aorta or transverse arch in 19, replacement of the descending or thoracoabdominal aorta in 27 and extensive replacement of the ascending, arch and descending or thoracoabdominal aorta in 4. Intraoperative cultures revealed most commonly staphylococcus 24%), enterococcus (12%), candida (6%) and gram negative rods (14%). Operative mortality was 8%, stroke 4%, paralysis 2%, hemodialysis 6%, and respiratory failure requiring tracheostomy 6%. Early reoperation for pseudoaneurysm of the CPA was necessary in 4 patients. One, two and five year survival was 84%, 76% and 64%, respectively. Conclusions Radical resection and in-situ reconstruction with CPA avoids placing prosthetic material in an infected field and provides good early and mid-term outcomes. However, early postoperative imaging is necessary given the risk of pseudoaneurysm formation

A 20-year multicenter analysis of dialysis-dependent patients who had aortic or mitral valve replacement: Implications for valve selection

Objective Valve selection in dialysis-dependent patients can be difficult because long-term survival is diminished and bleeding risks during anticoagulation treatment are greater in patients with renal failure. In this study we analyzed long-term outcomes of dialysis-dependent patients who underwent valve replacement to help guide optimal prosthetic valve type selection. Methods Dialysis-dependent patients who underwent aortic and/or mitral valve replacement at 3 institutions over 20 years were examined. The primary outcome was long-term survival. A Cox regression model was used to estimate survival according to 5 ages, presence of diabetes, and/or heart failure symptoms. Results Four hundred twenty-three available patients were analyzed; 341 patients had biological and 82 had mechanical valves. Overall complication and 30-day mortality rates were similar between the groups. Thirty-day readmission rates for biological and mechanical groups were 15% (50/341) and 28% (23/82; P = .005). Five-year survival was 23% and 33% for the biological and mechanical groups, respectively. After adjusting for age, New York Heart Association (NYHA) class, and diabetes using a multivariable Cox regression model, survival was similar between groups (hazard ratio, 0.93; 95% confidence interval, 0.66-1.29; P = .8). A Cox regression model on the basis of age, diabetes, and heart failure, estimated that patients only 30 or 40 years old, with NYHA class I-II failure without diabetes had a >50% estimated 5-year survival (P < .001). Conclusions Dialysis-dependent patients who underwent valve replacement surgery had poor long-term survival. Young patients without diabetes or NYHA III or IV symptoms might survive long enough to justify placement of a mechanical valve; however, a biological valve is suitable for most patients

NTFP harvesters as citizen scientists: Validating traditional and crowdsourced knowledge on seed production of Brazil nut trees in the Peruvian Amazon.

Understanding the factors that underlie the production of non-timber forest products (NTFPs), as well as regularly monitoring production levels, are key to allow sustainability assessments of NTFP extractive economies. Brazil nut (Bertholletia excelsa, Lecythidaceae) seed harvesting from natural forests is one of the cornerstone NTFP economies in Amazonia. In the Peruvian Amazon it is organized in a concession system. Drawing on seed production estimates of >135,000 individual Brazil nut trees from >400 concessions and ethno-ecological interviews with >80 concession holders, here we aimed to (i) assess the accuracy of seed production estimates by Brazil nut seed harvesters, and (ii) validate their traditional ecological knowledge (TEK) about the variables that influence Brazil nut production. We compared productivity estimates with actual field measurements carried out in the study area and found a positive correlation between them. Furthermore, we compared the relationships between seed production and a number of phenotypic, phytosanitary and environmental variables described in literature with those obtained for the seed production estimates and found high consistency between them, justifying the use of the dataset for validating TEK and innovative hypothesis testing. As expected, nearly all TEK on Brazil nut productivity was corroborated by our data. This is reassuring as Brazil nut concession holders, and NTFP harvesters at large, rely on their knowledge to guide the management of the trees upon which their extractive economies are based. Our findings suggest that productivity estimates of Brazil nut trees and possibly other NTFP-producing species could replace or complement actual measurements, which are very expensive and labour intensive, at least in areas where harvesters have a tradition of collecting NTFPs from the same trees over multiple years or decades. Productivity estimates might even be sourced from harvesters through registers on an annual basis, thus allowing a more cost-efficient and robust monitoring of productivity levels

A phase-field model of Hele-Shaw flows in the high viscosity contrast regime

A one-sided phase-field model is proposed to study the dynamics of unstable interfaces of Hele-Shaw flows in the high viscosity contrast regime. The corresponding macroscopic equations are obtained by means of an asymptotic expansion from the phase-field model. Numerical integrations of the phase-field model in a rectangular Hele-Shaw cell reproduce finger competition with the final evolution to a steady state finger the width of which goes to one half of the channel width as the velocity increases

Viscous fingering in liquid crystals: Anisotropy and morphological transitions

We show that a minimal model for viscous fingering with a nematic liquid crystal in which anisotropy is considered to enter through two different viscosities in two perpendicular directions can be mapped to a two-fold anisotropy in the surface tension. We numerically integrate the dynamics of the resulting problem with the phase-field approach to find and characterize a transition between tip-splitting and side-branching as a function of both anisotropy and dimensionless surface tension. This anisotropy dependence could explain the experimentally observed (reentrant) transition as temperature and applied pressure are varied. Our observations are also consistent with previous experimental evidence in viscous fingering within an etched cell and simulations of solidification.Comment: 12 pages, 3 figures. Submitted to PR

Forestry performance of Bertholletia excelsa Humn. & Bonpl Lecythidaceae under different fertilizers after two years of planting.

A espécie Bertholletia excelsa é frequentemente utilizada em reflorestamentos pelo alto grau de adaptabilidade e seu ótimo crescimento inicial. Com isso, esse trabalho objetivou estudar o crescimento de B. excelsa de acordo com diferentes tipos e concentrações de adubação, buscando contribuir para o desenvolvimento silvicultural dessa espécie. Para isso, foram plantadas mudas de Bertholletia excelsa na região de Madre de Dios em uma propriedade próxima a província de Puerto Maldonado no Peru. As mudas foram selecionadas quando apresentaram altura média de 22 cm para todos os tratamentos, sendo T1: Dolomita + SPT; T2: Dolomita + NPK; T3: Dolomita + SPT + Gesso agrícola; T4: Dolomita + NPK + Gesso agrícola e o tratamento controle sem modificações por adubação. O delineamento experimental utilizado foi em blocos ao acaso com cinco tratamentos e quatro repetições de 6 plântulas cada. Uma vez atendidos os pressupostos da ANOVA, os dados foram submetidos à análise de variância, havendo diferenças significativas entre os dados, as médias foram comparadas pelo teste de Tukey (p <0,05). A sobrevivência (%) foi avaliada a partir do número de indivíduos vivos em dois anos de medição. O tratamento T4 apresentou grande potencial silvicultural pelo que a adubação proporcionou ao desenvolvimento em altura e em diâmetro. Os tratamentos T1 e T3 não obtiveram um bom desempenho quando comparado ao controle, apresentando as menores taxas de crescimento em altura e em diâmetro, e as menores taxa de sobrevivência. O tratamento controle obteve um bom resultado não diferindo estatisticamente de T4, assim concluindo que não é necessário a adubação pré-plantio de B. excelsa

Seedling production of Bertholletia excelsa in response to seed origin and position inside fruit.

Bertholletia excelsa, conhecida como castanha-do-brasil, é uma espécie arbórea economicamente valiosa na Amazônia. Sementes de B. excelsa aparecem como um dos produtos florestais não-madeireiros mais importantes na Bolívia, Brasil e Peru. No entanto, estas sementes possuem dormência fisiológica, o que torna a germinação lenta, irregular e frequentemente em baixas percentagens. Tal característica biológica representa um gargalo para a produção de mudas de alta qualidade. Em um experimento em Puerto Maldonado, Peru, dez frutos foram coletados por indivíduo em 15 árvores de B. excelsa em cada uma de duas áreas: um plantio experimental e uma floresta nativa. Várias variáveis relacionadas à biometria de frutos, germinação, crescimento inicial e índices de qualidade de mudas foram mensuradas no sentido de comparar mudas de B. excelsa produzidas por sementes originadas de duas áreas e também quanto à posição de sementes no fruto, inferior e superior. Comprimento e diâmetro do fruto apresentaram baixa variação e a maioria dos frutos teve forma achatada. As sementes foram mais abundantes na posição inferior (média = 12,9 ± 2,2) do que na posição superior (média = 6,5 ± 2,1) no interior do fruto. Considerando o número total de sementes por fruto, as médias foram 9,4 ± 3,2 e 17,5 ± 3,7 para floresta plantada e nativa, respectivamente. A germinação completa não diferiu entre as áreas (F1, 56 = 1,945, p = 0,169). Mudas produzidas com sementes de plantios e da posição inferior no interior do fruto apresentaram maiores índices de qualidade