Visual programming in a heterogeneous multi-core environment

É do conhecimento geral de que, hoje em dia, a tecnologia evolui rapidamente. São criadas novas arquitecturas para resolver determinadas limitações ou problemas. Por vezes, essa evolução é pacífica e não requer necessidade de adaptação e, por outras, essa evolução pode Implicar mudanças. As linguagens de programação são, desde sempre, o principal elo de comunicação entre o programador e o computador. Novas linguagens continuam a aparecer e outras estão sempre em desenvolvimento para se adaptarem a novos conceitos e paradigmas. Isto requer um esforço extra para o programador, que tem de estar sempre atento a estas mudanças. A Programação Visual pode ser uma solução para este problema. Exprimir funções como módulos que recebem determinado Input e retomam determinado output poderá ajudar os programadores espalhados pelo mundo, através da possibilidade de lhes dar uma margem para se abstraírem de pormenores de baixo nível relacionados com uma arquitectura específica. Esta tese não só mostra como combinar as capacidades do CeII/B.E. (que tem uma arquitectura multi­processador heterogénea) com o OpenDX (que tem um ambiente de programação visual), como também demonstra que tal pode ser feito sem grande perda de performance. ABSTRACT; lt is known that nowadays technology develops really fast. New architectures are created ln order to provide new solutions for different technology limitations and problems. Sometimes, this evolution is pacific and there is no need to adapt to new technologies, but things also may require a change every once ln a while. Programming languages have always been the communication bridge between the programmer and the computer. New ones keep coming and other ones keep improving ln order to adapt to new concepts and paradigms. This requires an extra-effort for the programmer, who always needs to be aware of these changes. Visual Programming may be a solution to this problem. Expressing functions as module boxes which receive determined Input and return determined output may help programmers across the world by giving them the possibility to abstract from specific low-level hardware issues. This thesis not only shows how the CeII/B.E. (which has a heterogeneous multi-core architecture) capabilities can be combined with OpenDX (which has a visual programming environment), but also demonstrates that lt can be done without losing much performance.

The third dimension: new developments in cell culture models for colorectal research

Cellular models are important tools in various research areas related to colorectal biology and associated diseases. Herein, we review the most widely used cell lines and the different techniques to grow them, either as cell monolayer, polarized two-dimensional epithelia on membrane filters, or as three-dimensional spheres in scaffoldfree or matrix-supported culture conditions. Moreover, recent developments, such as gut-on-chip devices or the ex vivo growth of biopsy-derived organoids, are also discussed. We provide an overview on the potential applications but also on the limitations for each of these techniques, while evaluating their contribution to provide more reliable cellular models for research, diagnostic testing, or pharmacological validation related to colon physiology and pathophysiology.

Evaluation of the cytotoxic and genotoxic effects of benchmark multi-walled carbon nanotubes in relation to their physicochemical properties

To contribute with scientific evidence to the grouping strategy for the safety assessment of multi-walled carbon nanotubes (MWCNTs), this work describes the investigation of the cytotoxic and genotoxic effects of four benchmark MWCNTs in relation to their physicochemical characteristics, using two types of human respiratory cells. The cytotoxic effects were analysed using the clonogenic assay and replication index determination. A 48h-exposure of cells revealed that NM-401 was the only cytotoxic MWCNT in both cell lines, but after 8-days exposure, the clonogenic assay in A549 cells showed cytotoxic effects for all the tested MWCNTs. Correlation analysis suggested an association between the MWCNTs size in cell culture medium and cytotoxicity. No induction of DNA damage was observed after any MWCNTs in any cell line by the comet assay, while the micronucleus assay revealed that both NM-401 and NM-402 were genotoxic in A549 cells. NM-401 and NM-402 are the two longest MWCNTs analyzed in this work, suggesting that length may be determinant for genotoxicity. No induction of micronuclei was observed in Beas-2B cell line and the different effect in both cell lines is explained in view of the size-distribution of MWCNTs in the cell culture medium, rather than cell's specificities.

Cell phone–based health education messaging improves health literacy.

Background: The ubiquity of cell phones, which allow for short message service (SMS), provides new and innovative opportunities for disease prevention and health education. Objective: To explore the use of cell phone–based health education SMS to improve the health literacy of community residents in China. Methods: A multi-stage random sampling method was used to select representative study communities and participants ≥ 18 years old. Intervention participants were sent health education SMSs once a week for 1 year and controls were sent conventional, basic health education measures. Health literacy levels of the residents before and after the intervention were evaluated between intervention and control groups. Results: Public health literacy scores increased 1.5 points, from 61.8 to 63.3, after SMS intervention for 1 year (P<0.01); the increase was greater for males than females (2.01 vs. 1.03; P<0.01) and for Shenzhen local residents than non-permanent residents (2.56 vs. 1.14; P<0.01). The frequency of high health literacy scores was greater for the intervention than control group (22.03% to 30.93% vs. 22.07% to 20.82%). With health literacy as a cost-effective index, the cost-effectiveness per intervention was 0.54. Conclusion: SMS may be a useful tool for improving health literacy.

MULTI-BAND BOSE HUBBARD MODELS AND EFFECTIVE THREE-BODY INTERACTIONS

Experiments with ultracold atoms in optical lattice have become a versatile testing ground to study diverse quantum many-body Hamiltonians. A single-band Bose-Hubbard (BH) Hamiltonian was first proposed to describe these systems in 1998 and its associated quantum phase-transition was subsequently observed in 2002. Over the years, there has been a rapid progress in experimental realizations of more complex lattice geometries, leading to more exotic BH Hamiltonians with contributions from excited bands, and modified tunneling and interaction energies. There has also been interesting theoretical insights and experimental studies on “un- conventional” Bose-Einstein condensates in optical lattices and predictions of rich orbital physics in higher bands. In this thesis, I present our results on several multi- band BH models and emergent quantum phenomena. In particular, I study optical lattices with two local minima per unit cell and show that the low energy states of a multi-band BH Hamiltonian with only pairwise interactions is equivalent to an effec- tive single-band Hamiltonian with strong three-body interactions. I also propose a second method to create three-body interactions in ultracold gases of bosonic atoms in a optical lattice. In this case, this is achieved by a careful cancellation of two contributions in the pair-wise interaction between the atoms, one proportional to the zero-energy scattering length and a second proportional to the effective range. I subsequently study the physics of Bose-Einstein condensation in the second band of a double-well 2D lattice and show that the collision aided decay rate of the con- densate to the ground band is smaller than the tunneling rate between neighboring unit cells. Finally, I propose a numerical method using the discrete variable repre- sentation for constructing real-valued Wannier functions localized in a unit cell for optical lattices. The developed numerical method is general and can be applied to a wide array of optical lattice geometries in one, two or three dimensions.

Étude fonctionnelle d’un nouveau complexe multi-enzymatique régulant l’épigénome

L’ubiquitination, une modification post-traductionnelle importante pour le contrôle de nombreux processus cellulaires, est une réaction réversible. La réaction inverse, nommée déubiquitination est catalysée par les déubiquitinases (DUB). Nous nous sommes intéressés dans nos travaux à étudier l’ubiquitination de l’histone H2A (H2Aub), au niveau des résidus lysines 118 et 119 (K118/K119), une marque épigénétique impliquée dans la régulation de la prolifération cellulaire et la réparation de l’ADN. Le régulateur transcriptionnel BAP1, une déubiquitinase nucléaire, a été initialement identifié pour sa capacité à promouvoir la fonction suppressive de tumeurs de BRCA1. BAP1 forme un complexe multi-protéique avec plusieurs facteurs transcriptionnels et sa fonction principale est la déubiquitination de H2Aub. Plusieurs études ont démontré que BAP1 est un gène suppresseur de tumeurs majeur et qu’il est largement muté et inactivé dans une multitude de cancers. En effet, BAP1 émerge comme étant la DUB la plus mutée au niveau des cancers. Cependant, le ou les mécanismes d’action et de régulation du complexe BAP1 restent très peu connus. Dans cette étude nous nous sommes intéressés à la caractérisation moléculaire et fonctionnelle des partenaires protéiques de BAP1. De manière significative nous avons caractérisé un mécanisme unique de régulation entre deux composants majeurs du complexe BAP1 à savoir, HCF-1 et OGT. En effet, nous avons démontré que HCF-1 est requis pour maintenir le niveau protéique de OGT et que cette dernière est indispensable pour la maturation protéolytique de HCF-1 en promouvant son clivage par O-GlcNAcylation, une signalisation cellulaire nécessaire au bon fonctionnement de HCF-1. Également, nous avons découvert un nouveau mécanisme de régulation de BAP1 par l’ubiquitine ligase atypique UBE2O. En effet, UBE2O agit comme un régulateur négatif de BAP1 puisque l’ubiquitination de ce dernier induit sa séquestration dans le cytoplasme et l’inhibition de sa fonction suppressive de tumeurs. D’autre part nous nous sommes penchés sur la caractérisation de l’association de BAP1 avec deux facteurs de la famille des protéines Polycombes nommés ASXL1 et ASXL2 (ASXL1/2). Nous avons investigué le rôle de BAP1/ASXL1/2, particulièrement dans les mécanismes de déubiquitination et suppression de tumeurs. Nous avons démontré que BAP1 interagit directement iii via son domaine C-terminale avec le même domaine ASXM de ASXL1/2 formant ainsi deux complexes mutuellement exclusifs indispensables pour induire l’activité déubiquitinase de BAP1. De manière significative, ASXM s’associe avec BAP1 pour créer un nouveau domaine composite de liaison à l’ubiquitine. Ces interactions BAP1/ASXL1/2 régulent la progression harmonieuse du cycle cellulaire. De plus, la surexpression de BAP1 et de ASXL2 au niveau des fibroblastes induit la sénescence de manière dépendante de leurs interactions. D’autre part, nous avons identifié des mutations de cancers au niveau de BAP1 le rendant incapable de lier ASXL1/2, d’exercer sa fonction d’autodéubiquitination et de ce fait d’agir comme suppresseur de tumeurs. Ainsi nous avons révélé un lien étroit entre le gène suppresseur de tumeurs BAP1, son activité déubiquitinase et le contrôle de la prolifération cellulaire.

MULTI-WAVELENGTH SPECKLE REDUCTION FOR LASER PICO-PROJECTORS USING DIFFRACTIVE OPTICS

Personal electronic devices, such as cell phones and tablets, continue to decrease in size while the number of features and add-ons keep increasing. One particular feature of great interest is an integrated projector system. Laser pico-projectors have been considered, but the technology has not been developed enough to warrant integration. With new advancements in diode technology and MEMS devices, laser-based projection is currently being advanced for pico-projectors. A primary problem encountered when using a pico-projector is coherent interference known as speckle. Laser speckle can lead to eye irritation and headaches after prolonged viewing. Diffractive optical elements known as diffusers have been examined as a means to lower speckle contrast. Diffusers are often rotated to achieve temporal averaging of the spatial phase pattern provided by diffuser surface. While diffusers are unable to completely eliminate speckle, they can be utilized to decrease the resultant contrast to provide a more visually acceptable image. This dissertation measures the reduction in speckle contrast achievable through the use of diffractive diffusers. A theoretical Fourier optics model is used to provide the diffuser’s stationary and in-motion performance in terms of the resultant contrast level. Contrast measurements of two diffractive diffusers are calculated theoretically and compared with experimental results. In addition, a novel binary diffuser design based on Hadamard matrices will be presented. Using two static in-line Hadamard diffusers eliminates the need for rotation or vibration of the diffuser for temporal averaging. Two Hadamard diffusers were fabricated and contrast values were subsequently measured, showing good agreement with theory and simulated values. Monochromatic speckle contrast values of 0.40 were achieved using the Hadamard diffusers. Finally, color laser projection devices require the use of red, green, and blue laser sources; therefore, using a monochromatic diffractive diffuser may not optimal for color speckle contrast reduction. A simulation of the Hadamard diffusers is conducted to determine the optimum spacing between the two diffusers for polychromatic speckle reduction. Experimental measured results are presented using the optimal spacing of Hadamard diffusers for RGB color speckle reduction, showing 60% reduction in contrast.

CHARACTERIZATION OF THERMAL AND MECHANICAL PROPERTIES OF POLYPROPYLENE–BASED COMPOSITES FOR FUEL CELL BIPOLAR PLATES AND DEVELOPMENT OF EDUCATIONAL TOOLS IN HYDROGEN AND FUEL CELL TECHNOLOGIES

In this project we developed conductive thermoplastic resins by adding varying amounts of three different carbon fillers: carbon black (CB), synthetic graphite (SG) and multi–walled carbon nanotubes (CNT) to a polypropylene matrix for application as fuel cell bipolar plates. This component of fuel cells provides mechanical support to the stack, circulates the gases that participate in the electrochemical reaction within the fuel cell and allows for removal of the excess heat from the system. The materials fabricated in this work were tested to determine their mechanical and thermal properties. These materials were produced by adding varying amounts of single carbon fillers to a polypropylene matrix (2.5 to 15 wt.% Ketjenblack EC-600 JD carbon black, 10 to 80 wt.% Asbury Carbons’ Thermocarb TC-300 synthetic graphite, and 2.5 to 15 wt.% of Hyperion Catalysis International’s FIBRILTM multi-walled carbon nanotubes) In addition, composite materials containing combinations of these three fillers were produced. The thermal conductivity results showed an increase in both through–plane and in–plane thermal conductivities, with the largest increase observed for synthetic graphite. The Department of Energy (DOE) had previously set a thermal conductivity goal of 20 W/m·K, which was surpassed by formulations containing 75 wt.% and 80 wt.% SG, yielding in–plane thermal conductivity values of 24.4 W/m·K and 33.6 W/m·K, respectively. In addition, composites containing 2.5 wt.% CB, 65 wt.% SG, and 6 wt.% CNT in PP had an in–plane thermal conductivity of 37 W/m·K. Flexural and tensile tests were conducted. All composite formulations exceeded the flexural strength target of 25 MPa set by DOE. The tensile and flexural modulus of the composites increased with higher concentration of carbon fillers. Carbon black and synthetic graphite caused a decrease in the tensile and flexural strengths of the composites. However, carbon nanotubes increased the composite tensile and flexural strengths. Mathematical models were applied to estimate through–plane and in–plane thermal conductivities of single and multiple filler formulations, and tensile modulus of single–filler formulations. For thermal conductivity, Nielsen’s model yielded accurate thermal conductivity values when compared to experimental results obtained through the Flash method. For prediction of tensile modulus Nielsen’s model yielded the smallest error between the predicted and experimental values. The second part of this project consisted of the development of a curriculum in Fuel Cell and Hydrogen Technologies to address different educational barriers identified by the Department of Energy. By the creation of new courses and enterprise programs in the areas of fuel cells and the use of hydrogen as an energy carrier, we introduced engineering students to the new technologies, policies and challenges present with this alternative energy. Feedback provided by students participating in these courses and enterprise programs indicate positive acceptance of the different educational tools. Results obtained from a survey applied to students after participating in these courses showed an increase in the knowledge and awareness of energy fundamentals, which indicates the modules developed in this project are effective in introducing students to alternative energy sources.

Use of fluorescence lifetime imaging microscopy (FLIM) as a timer of cell cycle S phase

Incorporation of thymidine analogues in replicating DNA, coupled with antibody and fluorophore staining, allows analysis of cell proliferation, but is currently limited to monolayer cultures, fixed cells and end-point assays. We describe a simple microscopy imaging method for live real-time analysis of cell proliferation, S phase progression over several division cycles, effects of anti-proliferative drugs and other applications. It is based on the prominent (~ 1.7-fold) quenching of fluorescence lifetime of a common cell-permeable nuclear stain, Hoechst 33342 upon the incorporation of 5-bromo-2’-deoxyuridine (BrdU) in genomic DNA and detection by fluorescence lifetime imaging microscopy (FLIM). We show that quantitative and accurate FLIM technique allows high-content, multi-parametric dynamic analyses, far superior to the intensity-based imaging. We demonstrate its uses with monolayer cell cultures, complex 3D tissue models of tumor cell spheroids and intestinal organoids, and in physiological study with metformin treatment.

Aragonite-based scaffold for the treatment of knee osteochondral defects: results of a prospective multi-center trial at 2 years' follow-up

PURPOSE: To evaluate the clinical and MRI outcomes after the implantation of a nanostructured cell free aragonite-based scaffold in patients affected by knee chondral and osteochondral lesions. METHODS: 126 patients (94 men, 32 women; age 32.7±8.8 years) were included according to the following criteria: grade III or IV chondra/osteochondral lesions in the femoral condyles or throclea; 2) no limb axial deviation (i.e. varus or valgus knee > 5°); 3) no signs of knee instability; 4) no concurrent tibial or patellar chondral/osteochondral defects. All patients were treated by arthrotomic implantation of an aragonite based-scaffold by a press-fit technique. Patients were prospectively evaluated by IKDC, Tegner, Lysholm and KOOS scores preoperatively and then at 6, 12, 18 and 24-months follow-up. MRI was also performed to evaluate the amount of defect filling by regenerated cartilage. Failures were defined as the need for re-intervention in the index knee within the follow-up period. RESULTS: Average defect size was 2±1.3 cm2 and in most cases a single scaffold was used. A significant improvement in each clinical score was recorded from basal level to 24 months’ follow-up. In particular, the IKDC subjective score increased from 42.14±16 to 70.94±24.69 and the Tegner score improved from 2.95±1.90 to 4.82±1.85 (p<0.0005). Lysholm score and all the subscales of KOOS showed a similar trend over time. Age of the patient at implantation, size of the defect and BMI were correlated with lower clinical outcome. The presence of OA didn’t influence the clinical results. MRI evaluation showed a significant increase in defect filling over time, with the highest value reached at 24 months. Failures occurred in eleven patients (8.7%). CONCLUSION: The aragonite-based biomimetic osteochondral scaffold proved to be safe, and encouraging clinical and radiographic outcomes were documented up to 2 years’ follow-up.

Development of novel multi-substituted apatite nanophases with advanced functionalities for bone regeneration

In the field of bone substitutes is highly researched an innovative material able to fill gaps with high mechanical performances and able to stimulate cell response, permitting the complete restoration of the bone portion. In this respect, the synthesis of new bioactive materials able to mimic the compositional, morphological and mechanical features of bone is considered as the elective approach for effective tissue regeneration. Hydroxyapatite (HA) is the main component of the inorganic part of bone. Additionally ionic substitution can be performed in the apatite lattice producing different effects, depending from the selected ions. Magnesium, in substitution of calcium, and carbonate, in substitution of phosphate, extensively present in the biological bones, are able to improve properties naturally present in the apatitic phase, (i.e. biomimicry, solubility e osteoinductive properties). Other ions can be used to give new useful properties, like antiresorptive or antimicrobial properties, to the apatitic phase. This thesis focused on the development of hydroxyapatite nanophases with multiple ionic substitutions including gallium, or zinc ions, in association with magnesium and carbonate, with the purpose to provide double synergistic functionality as osteogenic and antibacterial biomaterial. Were developed bioactive materials based on Sr-substituted hydroxyapatite in the form of sintered targets. The obtained targets were treated with Pulsed Plasma Deposition (PED) resulting in the deposition of thin film coatings able to improve the roughness and wettability of PEEK, enhancing its osteointegrability. Were investigated heterogeneous gas-solid reactions, addressed to the biomorphic transformations of natural 3D porous structures into bone scaffolds with biomimetic composition and hierarchical organization, for application in load-bearing sites. The kinetics of the different reactions of the process were optimized to achieve complete and controlled phase transformation, maintaining the original 3-D morphology. Massive porous scaffolds made of ion-substituted hydroxyapatite and bone-mimicking structure were developed and tested in 3-D cell culture models.

Advanced cell culture platforms: methods for drug testing with microfluidics and microstructured devices

Advanced cell cultures are developing rapidly in biomedical research. Nowadays, various approaches and technologies are being used, however, these culturing systems present limitations from increasing complexity, requiring high costs, and not easily customization. We present two versatile and cost-effective methods for developing culturing systems that integrate 3D cell culture and microfluidic platforms. Firstly, for drug screening applications, many high-quality cell spheres of homogeneous size and shape are required. Conventional approaches usually have a dearth of control over the size and geometry of cell spheres and require sample collection and manipulation. To overcome this difficulty, in this study, hundreds of spheroids of several cell lines were generated using multi-well plates that housed our microdevices. Tumor spheroids grow at a uniform rate (in scaffolded or scaffold-free environments) and can be harvested at will. Microscopy imaging are done in real time during or after the culture. After in situ immunostaining, fluorescence imaging can be conducted while keeping the spatial distribution of spheroids in the microwells. Drug effects were successfully observed through viability, growth, and morphologic investigations. Also, we fabricated a microfluidic device suitable for directed and selective cell culture treatments. The microfluidic device was used to reproduce and confirm in vitro investigations carried out using normal culture methods, using a microglia cell line. The device layout and the syringe pump system, entirely designed in our lab, successfully allowed culture growth and medium flow regulation. Solution flows can be finely controlled, allowing treatments and immunofluorescence in one single chamber selectively. To conclude, we propose the development of two culturing platforms (microstructured well devices and in-flow microfluidic chip), which are the result of separate scientific investigations but have the primary goal of performing treatments in a reproducible manner. Our devices shall improve future studies on drug exposure testing, representing adjustable and versatile cell culture systems.

Egfr Activating Mutations And Their Association With Response To Platinum-doublet Chemotherapy In Brazilian Non-small Cell Lung Cancer Patients.

The aim of the study was to analyze the frequency of epidermal growth factor receptor (EGFR) mutations in Brazilian non-small cell lung cancer patients and to correlate these mutations with response to benefit of platinum-based chemotherapy in non-small cell lung cancer (NSCLC). Our cohort consisted of prospective patients with NSCLCs who received chemotherapy (platinum derivates plus paclitaxel) at the [UNICAMP], Brazil. EGFR exons 18-21 were analyzed in tumor-derived DNA. Fifty patients were included in the study (25 with adenocarcinoma). EGFR mutations were identified in 6/50 (12 %) NSCLCs and in 6/25 (24 %) adenocarcinomas; representing the frequency of EGFR mutations in a mostly self-reported White (82.0 %) southeastern Brazilian population of NSCLCs. Patients with NSCLCs harboring EGFR exon 19 deletions or the exon 21 L858R mutation were found to have a higher chance of response to platinum-paclitaxel (OR 9.67 [95 % CI 1.03-90.41], p = 0.047). We report the frequency of EGFR activating mutations in a typical southeastern Brazilian population with NSCLC, which are similar to that of other countries with Western European ethnicity. EGFR mutations seem to be predictive of a response to platinum-paclitaxel, and additional studies are needed to confirm or refute this relationship.

Solid Lipid Nanoparticles For Hydrophilic Biotech Drugs: Optimization And Cell Viability Studies (caco-2 & Hepg-2 Cell Lines).

Insulin was used as model protein to developed innovative Solid Lipid Nanoparticles (SLNs) for the delivery of hydrophilic biotech drugs, with potential use in medicinal chemistry. SLNs were prepared by double emulsion with the purpose of promoting stability and enhancing the protein bioavailability. Softisan(®)100 was selected as solid lipid matrix. The surfactants (Tween(®)80, Span(®)80 and Lipoid(®)S75) and insulin were chosen applying a 2(2) factorial design with triplicate of central point, evaluating the influence of dependents variables as polydispersity index (PI), mean particle size (z-AVE), zeta potential (ZP) and encapsulation efficiency (EE) by factorial design using the ANOVA test. Therefore, thermodynamic stability, polymorphism and matrix crystallinity were checked by Differential Scanning Calorimetry (DSC) and Wide Angle X-ray Diffraction (WAXD), whereas the effect of toxicity of SLNs was check in HepG2 and Caco-2 cells. Results showed a mean particle size (z-AVE) width between 294.6 nm and 627.0 nm, a PI in the range of 0.425-0.750, ZP about -3 mV, and the EE between 38.39% and 81.20%. After tempering the bulk lipid (mimicking the end process of production), the lipid showed amorphous characteristics, with a melting point of ca. 30 °C. The toxicity of SLNs was evaluated in two distinct cell lines (HEPG-2 and Caco-2), showing to be dependent on the concentration of particles in HEPG-2 cells, while no toxicity in was reported in Caco-2 cells. SLNs were stable for 24 h in in vitro human serum albumin (HSA) solution. The resulting SLNs fabricated by double emulsion may provide a promising approach for administration of protein therapeutics and antigens.

Autologous Platelet Gel: Five Cases Illustrating Use On Sickle Cell Disease Ulcers.

Leg ulcers represent a particularly disabling complication in patients with sickle cell disease (SCD). Platelet gel (PG) is a novel therapeutic strategy used for accelerating wound healing of a wide range of tissues through the continuous release of platelet growth factors. Here, we describe the use of PG preparation according to Anitua's PRGF (preparations rich in growth factors) protocol for treating chronic nonhealing ulcers in patients with SCD. A positive response occurred in 3 patients with an area reduction of 85.7% to 100%, which occurred within 7 to 10 weeks, and a 35.2% and 20.5% of area reduction in 2 other patients, who however, had large ulcers. After calcium chloride addition, the platelet-rich plasmas demonstrated enhanced platelet-derived growth factors-BB (P < .001), transforming growth factor-β1 (P = .015), vascular endothelial growth factors (P = .03), and hepatocyte growth factors (nonsignificant) secretion. Furthermore, calcium chloride addition induced a significant decrease in platelet number (P = .0134) and there was no leukocyte detection in the PG product. These results demonstrate that PG treatment might impact the healing of leg ulcers in sickle cell disease, especially in patients with small ulcers.