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1.
Article in English | MEDLINE | ID: mdl-38990833

ABSTRACT

Machine learning interatomic potentials (MLIPs) are one of the main techniques in the materials science toolbox, able to bridge ab initio accuracy with the computational efficiency of classical force fields. This allows simulations ranging from atoms, molecules, and biosystems, to solid and bulk materials, surfaces, nanomaterials, and their interfaces and complex interactions. A recent class of advanced MLIPs, which use equivariant representations and deep graph neural networks, is known as universal models. These models are proposed as foundation models suitable for any system, covering most elements from the periodic table. Current universal MLIPs (UIPs) have been trained with the largest consistent data set available nowadays. However, these are composed mostly of bulk materials' DFT calculations. In this article, we assess the universality of all openly available UIPs, namely MACE, CHGNet, and M3GNet, in a representative task of generalization: calculation of surface energies. We find that the out-of-the-box foundation models have significant shortcomings in this task, with errors correlated to the total energy of surface simulations, having an out-of-domain distance from the training data set. Our results show that while UIPs are an efficient starting point for fine-tuning specialized models, we envision the potential of increasing the coverage of the materials space toward universal training data sets for MLIPs.

2.
J Environ Manage ; 355: 120540, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38442658

ABSTRACT

This study presents a new method to incorporate the No Net Loss (NNL) principle within corporate Environmental, Social, and Governance (ESG) frameworks. This principle aims to ensure that biodiversity losses from human activities are fully offset. In this context, we tackle two main challenges: managing epistemic uncertainties in environmental modeling and accurately assessing compensatory areas needed to replace lost habitats. Focusing on Brazil's diverse biomes, which are undergoing rapid changes, we highlight the role of expert opinion surveys in addressing the uncertainties of the InVEST Habitat Quality, a model that simulates changes in landscape integrity under different land use scenarios. Our analysis across three of Brazil's regions - Caatinga Semi-arid, Cerrado Savanna, and Atlantic Forest - leverages open-source data to reveal substantial habitat losses due to activities like wind farm development, mining, and intensive agriculture, leading to a widespread decline in habitat quality. We introduce the Equivalent Biodiversity Area (EBA) metric to support NNL and Net Gain of Biodiversity efforts, measured in hectares. Findings show a reduction in EBA across all studied areas, highlighting the need for effective compensation strategies. Such strategies should merge Legal Reserves and ecological restoration into ESG policies, encourage landholder collaboration, and align with larger environmental efforts, such as watershed revitalization and Biodiversity Credits markets.


Subject(s)
Conservation of Natural Resources , Ecosystem , Humans , Brazil , Conservation of Natural Resources/methods , Biodiversity , Forests
3.
Mar Environ Res ; 195: 106382, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38309039

ABSTRACT

Many oceanic areas are still in need of baseline information on their structure and functioning. This is particularly important due to the ever-increasing impacts of global changes, which have led to the decline of marine life, and top predators in particular. The study of the structure and functioning of food webs can help understand the consequences of the disappearance of this group in marine ecosystems. Here, we develop a mass-balanced model for the marine Exclusive Economic Zone of the archipelago of Madeira, with emphasis on the role of marine megafauna in this ecosystem. A total of 50 functional groups were defined, representing coastal and open ocean areas, and epipelagic and deep-sea levels. The total biomass of the Madeira system was calculated at 52.68 t km-2, with lower trophic level organisms comprising 89.9 % of its biomass. Marine megafauna, namely pelagic sharks and coastal birds had the highest impacts across other trophic levels and were classified as keystone species, together with monk seals. The food web was characterized by a linear-like food chain, with a large proportion of specialized organisms, including dolphins, shearwaters, and large pelagic fish. The low mean trophic level of the system was 2.03, much lower than that of fisheries (4.3) targeting mainly tunas and Black scabbardfish. Considering the importance of marine megafauna in this food web and the threats they are facing; monitoring studies of key species in the region should be a priority. This study can now be used to build a needed ecosystem-based fisheries management and integrate conservation measures to declining species.


Subject(s)
Ecosystem , Food Chain , Animals , Oceans and Seas , Biomass , Fishes , Fisheries , Birds
4.
Poult Sci ; 102(11): 103021, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37666145

ABSTRACT

An infection by protozoa Eimeria spp. can cause coccidiosis, which negatively affects broiler chicken performance and causes economic and production losses. To understand the effect of coccidiosis on broilers' performance, we evaluated the independent variables and their interactions on the severity of coccidiosis in broilers that cause variation (Δ) of average daily feed intake (ADFI), average daily gain (ADG), and gain per feed (G:F) of broiler chicks using a meta-analysis approach. A database of 55 papers describing 63 experiments was gathered; broilers were challenged by Eimeria species (E. acervulina, E. maxima, E. tenella, and mixed) and at least 2 variables among ADFI, ADG, and feed conversion ratio (FCR) were studied. The variation induced by the challenge was calculated relative to the control group of each experiment. The indirect factors evaluated were days postinfection (DPI), Eimeria type and dose, infection age (IA), bird's mean age in the analyzed period, genetic line, sex, and whether they were raised in a cage or a pen. Graphical, correlation, and variance analyses were performed to evaluate the form of the responses. Then, a linear plateau model was adjusted for each response variable as a function of DPI to determine the consequences of the disease on the variation of performance over time after infection. The impact of the infection challenge on the variation of performance vs. nonchallenge broilers was only impacted by DPI (P < 0.05). The adjustment of the data with the linear plateau model allows us to determine the host response to the coccidiosis disease at different stages. At 5 DPI (acute phase), ΔADFI, ΔADG, ΔG:F were of -19.0; -39.8, and -25.5, respectively. After almost 13 DPI birds achieved the recovery phase for all variables with Δ varying from -19 to -3.75% for ADFI, from -39.8 to -10.5% for ADG, and from -25.5 to -7.24% for G:F. The Eimeria impact was higher in ADG than ADFI in all periods due to Eimeria aggressive action form causing lesions in gut epithelial reducing the use of nutrients and energy. The results can be used as a quantitative approach to determine the consequences of Eimeria spp. on broiler performance.

5.
Res Vet Sci ; 163: 104984, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37597504

ABSTRACT

This study aimed to evaluate the effects of different dietary balanced protein (BP) levels on the gut health, amino acid apparent ileal digestibility (AID), footpad dermatitis lesions, and litter quality in broiler chicks infected with Eimeria maxima. A total of 2400 male 14-day-old Cobb500 broilers were randomly allotted into 10 treatments with six replications containing 40 birds each in a factorial design of 5 × 2. The treatments consisted of five levels of BP (6.66%, 13.32%, 19.98%, 26.64%, and 33.3%), and broilers unchallenged (NCH) or challenged (CH). Broilers in the CH group received 1 mL of Eimeria maxima inoculum (7 × 103 sporulated oocysts/mL). Oocyst count in excreta, visual intestinal modifications score, morphology, and morphometrics of the ileum were used to determine gut health status. Additionally, amino acids and CP AID, litter quality, and footpad dermatitis were evaluated. An ANOVA and Kruskal-Wallis tests followed by post-hoc tests were performed. The oocyst count in the CH group increased with an increase in dieatary BP (P = 0.08). The incidence of intestinal modifications was higher in the CH group (P < 0.05) and increased with increasing dietary BP (P < 0.05). Morphometrics were impaired by the challenge (P < 0.05), and by the two highest BP levels (P < 0.05). Amino acids AID (methionine, methionine + cystine, arginine, and serine) were reduced by E. maxima challenge. An increase in dietary BP resulted in poor litter quality and high prevalence of of footpad dermatitis (P < 0.05). The E. maxima challenge and increased BP decreased gut health, litter quality, and cause a high incidence of footpad dermatitis.


Subject(s)
Antifibrinolytic Agents , Dermatitis , Eimeria , Animals , Male , Amino Acids , Chickens , Dermatitis/veterinary , Dietary Proteins , Methionine , Oocysts
6.
J Wound Care ; 32(Sup3a): xxii-xxx, 2023 Mar 02.
Article in English | MEDLINE | ID: mdl-36930537

ABSTRACT

Objective: The aim of this research was to evaluate the efficacy of a topical formulation containing chitosan-chamomile microparticles in cutaneous healing in rats. Method: Male Wistar rats (n=57) were randomly distributed into three groups: treatment; vehicle; and control. Evaluations were performed on days 2, 7 and 14 after the surgical procedure using skin lesion photography, and histological and biochemical analyses. Results: The results showed that there was no difference in the healing index and in the histological analysis of the inflammatory infiltrate among groups. Fibrogenesis was more significant in the group treated with the test formulation at day 7, and angiogenesis was greater in the vehicle and chamomile groups at day 2. The quantification of hydroxyproline showed a higher amount of collagen in the group treated with chamomile, mainly at day 14, although the histological quantification of collagen showed no difference between the groups. Conclusion: From the results of this study, it can be concluded that the formulation, although it had no effect on the healing time, improved the quality of the cicatricial tissue formed with a greater quantity of fibroblasts and collagen.


Subject(s)
Chitosan , Rats , Male , Animals , Rats, Wistar , Chitosan/pharmacology , Chamomile , Wound Healing , Collagen/pharmacology , Skin
7.
Molecules ; 28(2)2023 Jan 11.
Article in English | MEDLINE | ID: mdl-36677778

ABSTRACT

Microalgae such as Spirulina platensis have recently attracted the interest of the pharmaceutical, nutritional and food industries due to their high levels of proteins and bioactive compounds. In this study, we investigated the use of refractance window (RW) drying as an alternative technology for processing the microalga Spirulina biomass aiming at its dehydration. In addition, we also analyzed the effects of operating variables (i.e., time and temperature) on the quality of the final product, expressed by the content of bioactive compounds (i.e., total phenolics, total flavonoids, and phycocyanin). The results showed that RW drying can generate a dehydrated product with a moisture content lower than 10.0%, minimal visual changes, and reduced process time. The content of bioactive compounds after RW drying was found to be satisfactory, with some of them close to those observed in the fresh microalga. The best results for total phenolic (TPC) and total flavonoids (TFC) content were obtained at temperatures of around 70 °C and processing times around 4.5 h. The phycocyanin content was negatively influenced by higher temperatures (higher than 80 °C) and high exposing drying times (higher than 4.5 h) due to its thermosensibility properties. The use of refractance window drying proved to be an interesting methodology for the processing and conservation of Spirulina platensis, as well as an important alternative to the industrial processing of this biomass.


Subject(s)
Microalgae , Spirulina , Spirulina/metabolism , Microalgae/metabolism , Phycocyanin , Biomass , Flavonoids , Phenols
9.
J Microencapsul ; 39(7-8): 668-679, 2022.
Article in English | MEDLINE | ID: mdl-36476253

ABSTRACT

Solid lipid nanoparticles (SLNs) containing rutin were prepared to enhance their photochemopreventive effect on the skin. SLNs were produced by the hot melt microemulsion technique. Two 3D skin models: ex vivo skin explants and 3D tissue engineering skin were used to evaluate the photochemopreventive effect of topical formulations containing rutin SLNs, against ultraviolet B (UVB) radiation, inducing sunburn cells, caspase-3, cyclobutane pyrimidine dimers, lipid peroxidation, and metalloproteinase formation. The rutin SLNs presented average size of 74.22 ± 2.77 nm, polydispersion index of 0.16 ± 0.04, encapsulation efficiency of 98.90 ± 0.25%, and zeta potential of -53.0 ± 1.61 mV. The rutin SLNs were able to efficiently protect against UVB induced in the analysed parameters in both skin models. Furthermore, the rutin SLNs inhibited lipid peroxidation and metalloproteinase formation. These results support the use of rutin SLNs as skin photochemopreventive agents for topical application to the skin.


Subject(s)
Nanoparticles , Rutin , Rutin/pharmacology , Skin , Liposomes , Ultraviolet Rays/adverse effects
10.
Dig Liver Dis ; 54(12): 1681-1685, 2022 12.
Article in English | MEDLINE | ID: mdl-36115818

ABSTRACT

BACKROUND: In acute severe autoimmune hepatitis (AS-AIH), the early identification of predictors of non-response to corticosteroids and the optimal timing for liver transplantation (LT) remains controversial. AIMS: To determine early predictors of non-response to corticosteroids and to assess the usefulness of severity scores, namely the recently developed SURFASA. METHODS: Retrospective multicentre cohort study including consecutive patients admitted for AS-AIH between 2016 and 2020. Definitions- response to corticosteroids: LT-free survival at 90 days (D90); SURFASA score: -6.8 + 1.92x(D0-INR)+1.94xINR[(D3-D0)/D0]+1.64xbilirubin[(D3-D0)/D0]. RESULTS: We included 26 patients [median age 56 (45-69) years; 22 (84.6%) women]. All patients underwent corticosteroid therapy. Overall survival reached 73%. amongst the non-responders, 2 (7.8%) underwent LT and 5 (19.2%) died. The interval between admission and initiation of corticosteroids was not different between responders and non- responders [13 (7-23) vs. 8 (3-10), P:0.06], respectively. SURFASA and MELD-Na+ (D3) scores showed an AUROC of 0.96 (0.87-1) and 0.92 (0.82-0.99), respectively, for prediction of non-response. SURFASA >-2.5 had a sensitivity of 85.7% and a specificity of 100% and MELD-Na+ (D3) >26 had sensitivity of 85.7% and a specificity of 78% for the prediction of non-response. CONCLUSIONS: SURFASA and MELD-Na+ at D3 scores are useful in early identification of non-responders to corticosteroids.


Subject(s)
Hepatitis, Autoimmune , Liver Transplantation , Humans , Female , Middle Aged , Male , Hepatitis, Autoimmune/diagnosis , Hepatitis, Autoimmune/drug therapy , Liver Transplantation/adverse effects , Cohort Studies , Adrenal Cortex Hormones/therapeutic use , Acute Disease
11.
Animals (Basel) ; 12(11)2022 May 27.
Article in English | MEDLINE | ID: mdl-35681839

ABSTRACT

The objective of this study was to evaluate laying hens from 8 to 102 weeks old, regarding their changes in performance, body composition, and egg components produced in three scenarios of nutrition. Three treatments designed to contain different levels of balanced protein (BP) were randomly assigned to the experimental units, performing ten replicates per treatment with 20 birds each. A standard feed was formulated to meet hen requirements and the ideal ratio between essential amino acids. Then, two experimental feeds were formulated to contain 20% above or below the dietary BP used in the standard feed. The responses evaluated were cumulated feed intake (g), daily feed intake (g/day), body weight (g), body composition (g of protein, fat, and ash), hen-housed egg production (%/hen-housed), egg production (%), egg weight (g), egg mass (g), and egg components (percentages of yolk, albumen, and eggshell). The dietary BP influenced the body composition, egg production, egg weight, and egg mass of white laying hens. The increase in dietary BP was related to an increase in body contents and egg weight, whereas hens consuming the low dietary balanced protein presented a lower body weight, leaner, and produced smaller eggs.

12.
Am J Clin Oncol ; 45(5): 183-189, 2022 05 01.
Article in English | MEDLINE | ID: mdl-35393979

ABSTRACT

PURPOSE: The aim was to evaluate the effect of a topical formulation containing chitosan-coated Chamomilla recutita (L.) rauschert microparticles regarding the incidence, grade, and days for the appearance of radiodermatitis (RD) in women with breast cancer. METHODS: A double-blinded, controlled, randomized, phase II clinical trial developed with women diagnosed with breast cancer who will receive radiation therapy. The participants were randomly divided into 2 groups: control and treatment. They were followed up until the end of the treatment or the appearance of grade III RD. RESULTS: Fifty-four women were included in the study. There is no significant difference between the groups in the incidence (88.9% vs. 88.9%, P=1.0) or time to develop any grade of RD (3 days of difference, P=0.300). A significant reduction was observed in the incidence (P=0.03) and in the time to appearance (7 d of difference, P=0.01) grade 2 or >RD. In the follow-up evaluation (15 d after the end of treatment), the Chamomile group presented a superior skin recovery than the control group (P=0.0343). High-intensity local symptoms as pain, and pruritus were significantly reduced in the Chamomile group. CONCLUSIONS: Although no effect was observed with chamomile to reduce any grade of RD, it was effective to reduce grade 2 or >toxicity, to improve skin recovery and to diminish high-intensity local symptoms. TRIAL REGISTRATION: Brazilian Registry of Clinical Trials (ReBEC): RBR-9hnftg, April 29, 2019.


Subject(s)
Breast Neoplasms , Chitosan , Radiodermatitis , Breast Neoplasms/radiotherapy , Chamomile , Chitosan/therapeutic use , Female , Humans , Plant Extracts/therapeutic use , Radiodermatitis/etiology , Radiodermatitis/prevention & control
13.
J Phys Chem B ; 125(30): 8305-8312, 2021 08 05.
Article in English | MEDLINE | ID: mdl-34292748

ABSTRACT

Long-range electron transport has been widely and experimentally reported in Geobacter sulfurreducens pilus protein. However, a better understanding of the still undefined molecular arrangement can bring to light the role of key residues in this phenomenon. We propose a theoretical investigation of the electronic structure of aromatic residue groups in the protein through a classical molecular dynamics (MD) simulation, followed by a quantum mechanics/molecular mechanics (QM/MM) electronic study of different frames sampled from MD trajectories, an electrostatic potential and electron density analysis, an analysis of the density of states, and an investigation of hole formation through Dyson orbital calculations. We observe a highest occupied molecular orbital-lowest unoccupied molecular orbital (HOMO-LUMO) energy gap in the ranges of 1.4-2.3 eV and 2.9-3.3 eV and a less intense dipole moment along the aromatic residues in the presence of water in comparison to the system in vacuum. HOMO and LUMO electron densities highlight the occupation of one tyrosine residue in every representation for HOMO and a delocalization along two to three rings for LUMO. The results show how the electronic structure of the aromatic residues is sensitive to the ring arrangement and the surrounding environment. In our study, we observe that slight rearrangements in the fiber geometry can create temporary conditions for hole transfer.


Subject(s)
Geobacter , Molecular Dynamics Simulation , Electronics , Fimbriae, Bacterial
14.
Langmuir ; 37(26): 8014-8023, 2021 Jul 06.
Article in English | MEDLINE | ID: mdl-34152766

ABSTRACT

Copper-exchanged zeolites have demonstrated high selectivity in methane-to-methanol conversion carried out on copper-oxo centers. Nevertheless, the reaction can only occur if the methane molecules reach the active site while the methanol molecules must leave the material without high energetic cost for the migration. In this context, we have used force field-based molecular dynamics simulations with the potential of mean force method to estimate the energy barrier in cage to cage diffusion of methane and methanol molecules in the chabazite framework type zeolite. The results show considerably higher energy barrier for methanol diffusion. The steric effect of the active site and the electrostatic environment favors the CH3OH diffusion toward nonactive cages where it tends to accumulate due to the strong interactions with the zeolite. The same behavior is observed in the water molecules distribution, which emphasizes the control of the electrostatic potential over the polar molecules migration. For high concentration of polar molecules, the electrostatic effect is shielded and the driving force is reduced for CH3OH diffusion. The results show that if the electrostatic environment can be controlled, the product migration may be facilitated, which can improve the catalytic process.

15.
Open Forum Infect Dis ; 8(4): ofab100, 2021 Apr.
Article in English | MEDLINE | ID: mdl-33880393

ABSTRACT

We report a case of a man with chronic hepatitis C infection treated with remdesivir for COVID-19, resulting in lowered HCV viral load, followed by a rebound after its discontinuation. Concomitant treatment with tocilizumab possibly caused loss of anti-HBs.

16.
Acta Med Port ; 34(1): 56-58, 2021 Jan 04.
Article in Portuguese | MEDLINE | ID: mdl-33618795

ABSTRACT

Pregnancy is a rare condition in women with chronic kidney disease on hemodialysis, but its incidence has increased in recent years. Despite being a high-risk condition for both mother and fetus, there has been an improvement in care due to the increased number of cases described and the experience gained in dialysis therapy. We report the case of a multiparous 32-years-old women with chronic hypertension and chronic kidney disease with 10 years of evolution and difficult control, with a diagnosis of dichorionic/diamniotic twin pregnancy, 4 months after beginning hemodialysis. Pregnancy was managed by a multidisciplinary team, hemodialysis sessions were clinically and hemodynamically well tolerated, with good blood pressure and analytical control, as well as adequate development of both fetuses. She went into labor at 34 weeks and 6 days, so a caesarean section was performed, with 2 boys born with adequate weight for gestational age.


A gravidez é uma situação rara em mulheres com doença renal crónica sob hemodiálise. Contudo, a sua incidência tem aumentado nos últimos anos. Apesar de ser uma situação de elevado risco materno e fetal, tem havido uma melhoria na assistência, devido ao aumento do número de casos descritos e da experiência adquirida na terapia dialítica. Relatamos o caso de uma multípara de 32 anos com hipertensão crónica e doença renal crónica com 10 anos de evolução e difícil controlo, com diagnóstico de gravidez gemelar bicoriónica/biamniótica, quatro meses após início da hemodiálise. A gestação foi vigiada por uma equipa multidisciplinar, as sessões de hemodiálise bem toleradas clínica e hemodinamicamente, com bom controlo tensional e analítico seriado, assim como adequado desenvolvimento de ambos os fetos. Foi submetida a cesariana às 34 semanas e seis dias por início de trabalho de parto, tendo nascido dois meninos com peso adequado para a idade gestacional.


Subject(s)
Pregnancy Complications/therapy , Pregnancy, Twin , Renal Dialysis/methods , Renal Insufficiency, Chronic/therapy , Adult , Cesarean Section , Female , Humans , Male , Pregnancy , Pregnancy Outcome
17.
Eur J Gastroenterol Hepatol ; 33(1S Suppl 1): e114-e120, 2021 12 01.
Article in English | MEDLINE | ID: mdl-33177383

ABSTRACT

BACKGROUND AND AIMS: Sorafenib, used for advanced-stage hepatocellular carcinoma (HCC), has an overall survival (OS) of 10 months. However, some patients have better response and long-term survival (LTS). Aims to assess predictive factors for LTS. METHODS: Retrospectively reviewed 77 advanced HCC patients, starting sorafenib treatment between 2007 and 2016, with LTS (OS ≥24 months) as primary endpoint. Univariate and multivariable analysis of clinical variables were performed in order to identify predictive factors for LTS. RESULTS: Patients: seventy (90.9%) males; median age: 65 years (39-82). All had cirrhosis mostly HCV infection (n = 32, 41.6%). Majority were Child-Pugh class A (n = 50, 64.9%); median MELD-Na: 11 (6-30). Multinodular HCC: 74% (n = 57); portal vein invasion (PVI): 50.6% (n = 39); extrahepatic spread: 18.2% (n = 14). Median time between HCC diagnosis and sorafenib start: 3.3 months (0-37.6). Median OS: 13 months [95% confidence interval (CI) 8.2-17.8]. Twenty-five (32.5%) patients were considered LTS, with amedian OS: 52.3 months (95% CI 17.1-87.4). Multivariable analysis identified Child-Pugh class A [odds ratio (OR) 11.1, 95% CI 1.78-69.54] and absence of PVI (OR 7.88, 95% CI 1.56-39.8) as independent predictors of LTS. Sub-analysis of Child-Pugh class A: absence of PVI (OR 7.13, 95% CI 1.69-30.2) and alpha-fetoprotein <400 ng/ml (OR 5.82, 95% CI 1.18-28.75) independently related to LTS. CONCLUSION: Despite global short median OS, sorafenib treatment is associated with longer than 2-year survival in a sub-group, more likely in compensated liver disease and absence of PVI.


Subject(s)
Antineoplastic Agents , Carcinoma, Hepatocellular , Liver Neoplasms , Aged , Antineoplastic Agents/adverse effects , Carcinoma, Hepatocellular/pathology , Humans , Liver Neoplasms/pathology , Male , Niacinamide/adverse effects , Phenylurea Compounds/adverse effects , Retrospective Studies , Sorafenib/therapeutic use , Treatment Outcome
18.
An Acad Bras Cienc ; 92(3): e20200479, 2020.
Article in English | MEDLINE | ID: mdl-32876140

ABSTRACT

This paper records the first occurrence of the genus Myrmicium Westwood, 1854 in the Cretaceous of Gondwana and describes it as a new species Myrmicium araripterum sp. nov, based on the most complete specimen of this genus yet known, which represents the largest specimen of the grade "Symphyta" ever found in the Crato Formation.


Subject(s)
Hymenoptera , Animals , Brazil , Fossils
19.
Carbohydr Polym ; 249: 116838, 2020 Dec 01.
Article in English | MEDLINE | ID: mdl-32933682

ABSTRACT

Defibrillation of bacterial cellulose by ultra-refining was efficient to release nanofibers (BCNF) which were spray dried with the matrices formers mannitol (MN), maltodextrin or hydroxypropylmethylcellulose. The best microsystem comprised the association of BCNF and MN, so the selected microparticles were loaded with diclofenac sodium or caffeine. Depending on the proportion of BCNF, the nanofibers collapse promoted by spray drying can occur onto surface or into microparticles core, leading to different release behaviors. Samples showed pH-dependent drug release, so the microsystem developed with the lowest BCNF concentration showed important trend to gastroresistance. Caffeine was spray dried as a free drug and for this reason it was devoid of any control over release rates. The set of results showed BCNF can be considered an interesting and potential pharmaceutical excipient for lipophilic drugs. Beyond that, BCNF association with MN can lead to novel enteric drug delivery systems based on natural polymers.


Subject(s)
Caffeine/pharmacology , Cellulose/chemistry , Diclofenac/pharmacology , Drug Delivery Systems , Excipients/chemistry , Gastrointestinal Tract/drug effects , Nanofibers/chemistry , Animals , Bacteria/metabolism , Caffeine/chemistry , Diclofenac/chemistry , Drug Compounding , Drug Liberation , Fibroblasts/drug effects , Mice , Polymers
20.
IEEE Trans Neural Netw Learn Syst ; 31(10): 4389-4393, 2020 Oct.
Article in English | MEDLINE | ID: mdl-31831445

ABSTRACT

We show theoretical similarities between the least squares support vector regression (LS-SVR) model with a radial basis functions (RBFs) kernel and maximum a posteriori (MAP) inference on Bayesian RBF networks with a specific Gaussian prior on the regression weights. Although previous articles have pointed out similar expressions between those learning approaches, we explicitly and formally state the existing correspondences. We empirically demonstrate our result by performing computational experiments with standard regression benchmarks. Our findings open a range of possibilities to improve LS-SVR by borrowing strength from well-established developments in Bayesian methodology.

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