Antioxidant PLA Composites Containing Lignin for 3D Printing Applications: A Potential Material for Healthcare Applications

Lignin (LIG) is a natural biopolymer with well-known antioxidant capabilities. Accordingly, in the present work, a method to combine LIG with poly(lactic acid) (PLA) for fused filament fabrication applications (FFF) is proposed. For this purpose, PLA pellets were successfully coated with LIG powder and a biocompatible oil (castor oil). The resulting pellets were placed into an extruder at 200 °C. The resulting PLA filaments contained LIG loadings ranging from 0% to 3% (w/w). The obtained filaments were successfully used for FFF applications. The LIG content affected the mechanical and surface properties of the overall material. The inclusion of LIG yielded materials with lower resistance to fracture and higher wettabilities. Moreover, the resulting 3D printed materials showed antioxidant capabilities. By using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method, the materials were capable of reducing the concentration of this compound up to ca. 80% in 5 h. This radical scavenging activity could be potentially beneficial for healthcare applications, especially for wound care. Accordingly, PLA/LIG were used to design meshes with different designs for wound dressing purposes. A wound healing model compound, curcumin (CUR), was applied in the surface of the mesh and its diffusion was studied. It was observed that the dimensions of the meshes affected the permeation rate of CUR. Accordingly, the design of the mesh could be modified according to the patient’s needsThis work was supported by the Wellcome Trust Biomedical Vacation Scholarship (SS 213361/Z/18/Z) and the Society for Applied Microbiology Student Placement ScholarshipS

Mechanisms of tissue uptake and retention of paclitaxel-coated balloons: impact on neointimal proliferation and healing

Background: The efficacy of paclitaxel-coated balloons (PCB) for restenosis prevention has been demonstrated in humans. However, the mechanism of action for sustained drug retention and biological efficacy following single-time drug delivery is still unknown. Methods and results The pharmacokinetic profile and differences in drug concentration (vessel surface vs arterial wall) of two different paclitaxel coating formulations (3 µg/mm2) displaying opposite solubility characteristics (CC=crystalline vs AC=amorphous) were tested in vivo and compared with paclitaxel-eluting stents (PES). Also, the biological effect of both PCB formulations on vascular healing was tested in the porcine coronary injury model. One hour following balloon inflation, both formulations achieved similar arterial paclitaxel levels (CC=310 vs AC=245 ng/mg; p=NS). At 24 h, the CC maintained similar tissue concentrations, whereas the AC tissue levels declined by 99% (p<0.01). At this time point, arterial levels were 20-fold (CC) and 5-fold (AC) times higher compared to the PES group (p<0.05). At 28 days, arterial levels retained were 9.2% (CC) and 0.04% (AC, p<0.01) of the baseline levels. Paclitaxel concentration on the vessel surface was higher in the CC at 1 (CC=36.7% vs AC=13.1%, p<0.05) and 7 days (CC=38.4% vs AC=11%, p<0.05). In addition, the CC induced higher levels of neointimal inhibition, fibrin deposition and delayed healing compared with the AC group. Conclusions: The presence of paclitaxel deposits on the vessel surface driving diffusion into the arterial tissue in a time-dependent fashion supports the mechanism of action of PCB. This specific pharmacokinetic behaviour influences the patterns of neointimal formation and healing

Modelado numérico del proceso de secado solar de manzanas en el municipio de Nuevo Colón-Boyacá

El secado de frutales caducifolios, como las manzanas, es un proceso en el cual se disminuye la cantidad de humedad contenida dentro del fruto. Además, se busca prolongar el tiempo en el que conserven propiedades organolépticas, físicas y químicas actas para el consumo humano, también este proceso tiene por objeto disminuir los desperdicios y generar una economía rentable en empresas agrícolas productoras de alimentos deshidratados. Según los estándares nacionales, en Colombia se pierde y se desperdicia el 58 % de las frutas y las verduras (6,1 millones de toneladas), mientras que en el mundo el promedio está en 45 % [1]. En Colombia, la región que tiene el mayor nivel de participación en la pérdida nacional es la Centro-oriental (Cundinamarca, Santander, Norte de Santander y Boyacá) con una participación del 1 millón de toneladas entre frutas y verduras. Este proyecto busca realizar una simulación del proceso de transferencia de calor presente en un secador solar de manzanas. En el proceso de secado de frutas intervienen diversas variables físicas, como la temperatura, la velocidad del aire, la humedad de la fruta, el tiempo de secado [12] y para garantizar una calidad óptima en la fruta se deben controlar dichas variables, los fenómenos de transferencia de calor a utilizar son: la convección de calor producida en el aire con los sólidos, la radiación del sol, y la conducción entre los sólidos que componen la estructura de un equipo secador. Existen diversos softwares que facilitan la elaboración de esta simulación como:&nbsp; Matlab o Python. Finalmente se presentan los resultados de las simulaciones realizadas para que con ellas se pueda continuar con el proceso de diseño del secador.&nbsp;The drying of fruits such as apples is a process in wich the amount of moisture is decreased. Furtheremore this process looks for to prolong the time wich the fruits preserve organolectic, physical and chemical properties for human consumption, this process also aims to reduce waste and generate a profitable economy in agricultural companies producing dehydrated foods. According to national standards, 58 % of fruits and vegetables are lost and wasted in Colombia, while in the world the average is 45 % [1]. In Colombia, the region with the highest level of participation&nbsp; in the national loss is the Central Eastern (Cundinamarca, Santander, Norte de Santander and Boyacá) with one million tons. This project seeks to simulate the heat transfer process in a solar apple dryer. In the fruit drying process, various physical variables are involved, such as temperature, air velocity, fruit moisture, drying time [12]. In order to guarantee an optimal quality in the fruit, these variables must be controlled, the heat transfer phenomena to be used are: the convection of heat produced in the air with the solids, the radiation of the sun, and the conduction between the solids of the structure of a dryer equipment. There are several software that facilitate the elaboration of this simulation as: Matlab or Python. Finally the results of the simulations are presented. With these results you can continue with the dryer design process

Modelado numérico del proceso de secado solar de manzanas en el municipio de Nuevo Colón-Boyacá

El secado de frutales caducifolios, como las manzanas, es un proceso en el cual se disminuye la cantidad de humedad contenida dentro del fruto. Además, se busca prolongar el tiempo en el que conserven propiedades organolépticas, físicas y químicas actas para el consumo humano, también este proceso tiene por objeto disminuir los desperdicios y generar una economía rentable en empresas agrícolas productoras de alimentos deshidratados. Según los estándares nacionales, en Colombia se pierde y se desperdicia el 58 % de las frutas y las verduras (6,1 millones de toneladas), mientras que en el mundo el promedio está en 45 % [1]. En Colombia, la región que tiene el mayor nivel de participación en la pérdida nacional es la Centro-oriental (Cundinamarca, Santander, Norte de Santander y Boyacá) con una participación del 1 millón de toneladas entre frutas y verduras. Este proyecto busca realizar una simulación del proceso de transferencia de calor presente en un secador solar de manzanas. En el proceso de secado de frutas intervienen diversas variables físicas, como la temperatura, la velocidad del aire, la humedad de la fruta, el tiempo de secado [12] y para garantizar una calidad óptima en la fruta se deben controlar dichas variables, los fenómenos de transferencia de calor a utilizar son: la convección de calor producida en el aire con los sólidos, la radiación del sol, y la conducción entre los sólidos que componen la estructura de un equipo secador. Existen diversos softwares que facilitan la elaboración de esta simulación como:&nbsp; Matlab o Python. Finalmente se presentan los resultados de las simulaciones realizadas para que con ellas se pueda continuar con el proceso de diseño del secador.&nbsp;The drying of fruits such as apples is a process in wich the amount of moisture is decreased. Furtheremore this process looks for to prolong the time wich the fruits preserve organolectic, physical and chemical properties for human consumption, this process also aims to reduce waste and generate a profitable economy in agricultural companies producing dehydrated foods. According to national standards, 58 % of fruits and vegetables are lost and wasted in Colombia, while in the world the average is 45 % [1]. In Colombia, the region with the highest level of participation&nbsp; in the national loss is the Central Eastern (Cundinamarca, Santander, Norte de Santander and Boyacá) with one million tons. This project seeks to simulate the heat transfer process in a solar apple dryer. In the fruit drying process, various physical variables are involved, such as temperature, air velocity, fruit moisture, drying time [12]. In order to guarantee an optimal quality in the fruit, these variables must be controlled, the heat transfer phenomena to be used are: the convection of heat produced in the air with the solids, the radiation of the sun, and the conduction between the solids of the structure of a dryer equipment. There are several software that facilitate the elaboration of this simulation as: Matlab or Python. Finally the results of the simulations are presented. With these results you can continue with the dryer design process

CAR T cell therapy in B-cell acute lymphoblastic leukaemia: Insights from mathematical models

Immunotherapies use components of the patient immune system to selectively target cancer cells. The use of CAR T cells to treat B-cell malignancies --leukaemias and lymphomas-- is one of the most successful examples, with many patients experiencing long-lasting complete responses to this therapy. This treatment works by extracting the patient's T cells and adding them the CAR group, which enables them to recognize and target cells carrying the antigen CD19+, that is expressed in these haematological tumors. Here we put forward a mathematical model describing the time response of leukaemias to the injection of CAR T-cells. The model accounts for mature and progenitor B-cells, tumor cells, CAR T cells and side effects by incorporating the main biological processes involved. The model explains the early post-injection dynamics of the different compartments and the fact that the number of CAR T cells injected does not critically affect the treatment outcome. An explicit formula is found that provides the maximum CAR T cell expansion in-vivo and the severity of side effects. Our mathematical model captures other known features of the response to this immunotherapy. It also predicts that CD19+ tumor relapses could be the result of the competition between tumor and CAR T cells analogous to predator-prey dynamics. We discuss this fact on the light of available evidences and the possibility of controlling relapses by early re-challenging of the tumor with stored CAR T cells

1983: Abilene Christian College Bible Lectures - Full Text

LIGHTS IN A WORLD OF DARKNESS Being the Abilene Christian University Annual Bible Lectures 1983 Published by Abilene Christian University Book Store ACU Station Abilene, Texas 7969

Potential ecological and socio-economic effects of a novel megaherbivore introduction: the hippopotamus in Colombia

Introduced species can have strong ecological, social and economic effects on their non-native environment. Introductions of megafaunal species are rare and may contribute to rewilding efforts, but they may also have pronounced socio-ecological effects because of their scale of influence. A recent introduction of the hippopotamus Hippopotamus amphibius into Colombia is a novel introduction of a megaherbivore onto a new continent, and raises questions about the future dynamics of the socio-ecological system into which it has been introduced. Here we synthesize current knowledge about the Colombian hippopotamus population, review the literature on the species to predict potential ecological and socio-economic effects of this introduction, and make recommendations for future study. Hippopotamuses can have high population growth rates (7–11%) and, on the current trajectory, we predict there could be 400–800 individuals in Colombia by 2050. The hippopotamus is an ecosystem engineer that can have profound effects on terrestrial and aquatic environments and could therefore affect the native biodiversity of the Magdalena River basin. Hippopotamuses are also aggressive and may pose a threat to the many inhabitants of the region who rely upon the Magdalena River for their livelihoods, although the species could provide economic benefits through tourism. Further research is needed to quantify the current and future size and distribution of this hippopotamus population and to predict the likely ecological, social and economic effects. This knowledge must be balanced with consideration of social and cultural concerns to develop appropriate management strategies for this novel introduction

High serum levels of tissue inhibitor of matrix metalloproteinase-1 during the first week of a malignant middle cerebral artery infarction in non-surviving patients

Background: Higher circulating levels of tissue inhibitor of matrix metalloproteinases (TIMP)-1 early after ischemic stroke have been associated with lower survival. The objectives of this study were to determine serum TIMP-1 levels during the first week of a severe cerebral infarction in surviving and non-surviving patients, and whether those levels during the first week could be used as a mortality biomarker for these patients. Methods: We included patients with severe malignant middle cerebral artery infarction (MMCAI) defined as computer tomography showing ischaemic changes in more than 50% of the middle cerebral artery territory and Glasgow Coma Scale (GCS) ≤ 8. We measured serum levels of matrix metalloproteinases (MMP)-9 and TIMP-1. End-point study was 30-day mortality. Results: We found higher TIMP-1 concentrations at days 1 (p < 0.001), 4 (p = 0.001), and 8 (p = 0.03) of MMCAI in nonurviving (n = 34) than in surviving (n = 34) patients. We found lower serum MMP-9 concentrations at day 1 (p = 0.03) of MMCAI and no significant differences at days 4 and 8. ROC curve analysis of TIMP-1 concentrations performed at days 1, 4, and 8 of MMCAI showed an area under curve to predict 30-day mortality of 81% (p < 0.001), 80% (p < 0.001) and 72% (p = 0.07) respectively. Conclusions: The new findings of our study were that non-surviving MMCAI patients showed higher serum TIMP-1 levels during the first week of MMCAI that surviving patients, and those levels during the first week of MMCAI could be used as mortality biomarkers

Hyperspectral imaging benchmark based on machine learning for intraoperative brain tumour detection

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Matrix metalloproteinase-9, -10, and tissue inhibitor of matrix metalloproteinases-1 blood levels as biomarkers of severity and mortality in sepsis

INTRODUCTION: Matrix metalloproteinases (MMPs) play a role in infectious diseases through extracellular matrix (ECM) degradation, which favors the migration of immune cells from the bloodstream to sites of inflammation. Although higher levels of MMP-9 and tissue inhibitor of matrix metalloproteinases-1 (TIMP-1) have been found in small series of patients with sepsis, MMP-10 levels have not been studied in this setting. The objective of this study was to determine the predictive value of MMP-9, MMP-10, and TIMP-1 on clinical severity and mortality in a large series of patients with severe sepsis. METHODS: This was a multicenter, observational, and prospective study carried out in six Spanish Intensive Care Units. We included 192 (125 surviving and 67 nonsurviving) patients with severe sepsis and 50 age- and sex-matched healthy controls in the study. Serum levels of MMP-9, MMP-10, TIMP-1, tumor necrosis factor (TNF)-alpha, and interleukin (IL)-10 were measured in patients with severe sepsis at the time of diagnosis and in healthy controls. RESULTS: Sepsis patients had higher levels of MMP-10 and TIMP-1, higher MMP-10/TIMP-1 ratios, and lower MMP-9/TIMP-1 ratios than did healthy controls (P < 0.001). An association was found between MMP-9, MMP-10, TIMP-1, and MMP-9/TIMP-1 ratios and parameters of sepsis severity, assessed by the SOFA score, the APACHE-II score, lactic acid, platelet count, and markers of coagulopathy. Nonsurviving sepsis patients had lower levels of MMP-9 (P = 0.037), higher levels of TIMP-1 (P < 0.001), lower MMP-9/TIMP-1 ratio (P = 0.003), higher levels of IL-10 (P < 0.001), and lower TNF-alpha/IL-10 ratio than did surviving patients. An association was found between MMP-9, MMP-10, and TIMP-1 levels, and TNF-alpha and IL-10 levels. The risk of death in sepsis patients with TIMP-1 values greater than 531 ng/ml was 80% higher than that in patients with lower values (RR = 1.80; 95% CI = 1.13 to 2.87;P = 0.01; sensitivity = 0.73; specificity = 0.45). CONCLUSIONS: The novel findings of our study on patients with severe sepsis (to our knowledge, the largest series reporting data about MMP levels in sepsis) are that reduced MMP-9/TIMP-1 ratios and increased MMP-10 levels may be of great pathophysiologic significance in terms of severity and mortality, and that TIMP-1 levels may represent a biomarker to predict the clinical outcome of patients with sepsis