Production of bioactive and functional frozen yogurt through easy-to-make microspheres incorporation.

In the food industry, the microencapsulation process is important to control the release of active encapsulated ingredients, mask unwanted flavors, colors, and unpleasant smells, increase shelf life, and protect encapsulated components from light, moisture, and nutritional loss. In this process, microspheres are formed using cross-linked polymer, which can incorporate aqueous or oily ingredients, using simple physicochemical methods of phase separation by coacervation, without the need for organic solvents. In this context, this study aimed to develop bioactive, functional frozen yogurt through the incorporation of microspheres loaded with ascorbic acid or omega 3. The process used resulted in small microspheres (15-80 µm), imperceptible to the palate, and capable of swelling about 14 times, being suitable for incorporating omega 3, without altering the swelling, and extending the shelf life of the ascorbic acid for 6 weeks, even in an acid medium. Also, the matrix does not affect the properties of frozen yogurt and acts as a stabilizer, contributing to reduce the melting rate. The sensory analysis proved that encapsulation was promising to mask the taste and odor of omega 3 and to protect the ascorbic acid, without altering the properties and quality of the frozen product.

The effect of temperature on the initial development of Brycon amazonicus Spix & Agassiz, 1829 as tool for micromanipulation of embryos.

Primordial germ cell (PGC) transplant is a promising tool in aquaculture; however, successful use of this technique requires in depth knowledge of the early stages of embryo and larval development. The aim of this study was to analyse the effect of different temperatures (22, 26, and 30°C) on the early development of B. amazonicus. The newly fertilized eggs were distributed into tanks with controlled temperature and oxygenation. Samples were collected at pre-established times and analysed under light and fluorescence microscopy. Temperature influenced the speed and duration of each stage of early development, including hatching time. The highest pronuclei fusion rate was observed 8 min post-fertilization (mpf) at 22 and 26°C, and 6 mpf at 30°C. The duration of the 512-1000 blastomeres phase during in the blastocyst stage was 1 h 30 min at 22°C, and 25 min at 26 and 30°C. Hatching occurred at 24 h 30 mpf at 22°C, 16 h post-fertilization (hpf) at 26°C, and 11 h 30 mpf at 30°C. The rate of morphologically normal larvae was 88.34% at 22°C, 90.49% at 26°C, and 73% at 30°C. Malformations of the head, yolk sac, heart, and tail were observed in all temperatures. Nevertheless, B. amazonicus embryos were able to develop satisfactory in all three temperatures tested. These results enable embryo manipulation at different temperatures to optimize the micromanipulation time of embryos and larvae for biotechnological studies.

Genotoxic and chemopreventive assessment of Cynara scolymus L. aqueous extract in a human-derived liver cell line.

Cynara scolymus L., popularly known as artichoke, is consumed as food and used as tea infusions for pharmacological purposes to treat liver dysfunctions and other conditions. Scientific data on the safety and protective effect of artichoke in human-derived liver cells is missing. This study investigated the genotoxic and modulatory effect of a liophilized extract suspended in water of C. scolymus L. leaves. Four extract concentrations (0.62, 1.25, 2.5 and 5.0 mg/mL) were evaluated using the comet assay on human hepatocyte cultures, HepG2 cells. Genotoxicity was assessed after two treatment periods, 1 and 24 h. Antigenotoxicity was evaluated against oxidative lesions induced by hydrogen peroxide in pre-, simultaneous and post-treatment protocols. Artichoke leaves aqueous extract induced genotoxic effects in HepG2 cells after 1- and 24-h treatments. In turn, extract concentrations of 0.62, 1.25 and 2.5 mg/mL, exhibited a protective effect in pretreatment, compared to hydrogen peroxide alone. However, in simultaneous and post-treatment protocols, only the lowest concentration reduced the frequency of DNA damage induced by hydrogen peroxide. In addition, in the simultaneous treatment protocol, the highest artichoke extract concentration increased hydrogen peroxide genotoxicity. It can be concluded that artichoke is genotoxic, in vitro, to HepG2 cells, but can also modulate hydrogen peroxide DNA damage.

Early development of Betta splendens under stereomicroscopy and scanning electron microscopy.

Betta splendens is a very important ornamental species. The current paper describes the embryonic and larval development of B. splendens under stereomicroscopy and scanning electron microscopy. Eggs and larvae from natural spawning were collected at different developmental stages at previously established intervals and analysed. The eggs of B. splendens are yellowish, clear, spherical, demersal, translucent and telolecithal with a large amount of yolk. Between 0-2 h post-initial collection (hpIC), the eggs were at the egg cell, first cleavage and morula stages. The blastula stage was identified at 2-3 hpIC and the early gastrula phase was observed at 3-4 hpIC with 20% epiboly, which was finalized after 13-18 hpIC. When the pre-larvae were ready to hatch, the appearance of somites and the free tail were observed, at 23-25 hpIC. At 29 hpIC, the majority of larvae had already hatched at an average temperature of 28.4 ± 0.2°C. The newly hatched larvae measured 2.47 ± 0.044 mm total length. The mouth opened at 23 h post-hatching (hPH) and the yolk sac was totally absorbed at 73 hPH. After 156 hPH, the heart was pumping blood throughout the entire larval body. The caudal fin, operculum and eyes were well developed at 264 hPH. When metamorphosis was complete at 768 hPH, the larvae became juveniles. The current study presents the first results about early development of B. splendens and provides relevant information for its reproduction, rearing and biology.

Hatching, survival and deformities of piracanjuba (Brycon orbignyanus) embryos subjected to different cooling protocols.

Groups of one hundred Brycon orbignyanus embryos at the stage of blastopore closure were subjected to different cooling protocols. Different combinations and concentrations of cryoprotectants were tested: sucrose, methanol, ethylene glycol and dimethyl sulfoxide (Me2SO); at different temperatures (0.0±2.0°C and 8.0±2.0°C) and refrigeration times (6, 10, 24, 72 and 168 h), with the exception of the positive control (incubation without previous cooling). At the end of each refrigeration time, the embryos were acclimatized, rehydrated and incubated to determine hatching, survival and deformity rates. Morphological analysis of embryos was also carried out. The results showed that temperature and refrigeration time are critical factors for embryo survival. No embryos survived after 24, 72 and 168 h of refrigeration. Furthermore, when the refrigeration time increased from 6 to 10h and the temperature decreased from 8.0±2.0°C to 0.0±2.0°C, mortality rates increased significantly. It was also found that in all protocols dead eggs and/or larvae with some degree of deformity were present. The main larval deformities observed were the malformation of the head, tail, yolk sac, vertebral column and eyes.

Self-Curing Glass Ionomer Cement Covered by Photopolymerizable Adhesive for Protection of Mucoperiosteal or Gingival Flap Sutures in Canine Oral Surgery.

Periodontal disease is one of the main affections of the oral cavity of dogs. Its main complication is the formation of periapical abscess, which, when affecting the maxillary canine teeth, can lead to the formation of oronasal fistulae. The objective of this study was to evaluate the efficiency of self-curing glass ionomer cement, covered by photopolymerizable adhesive, as a protective element for mucoperiosteal or gingival flap sutures in oral surgery of dogs. We studied 15 dogs from the clinical routine of the dental service of a teaching veterinary hospital, which needed oral surgeries to correct oronasal fistulae, defects or oral cavity communications, regardless of the causal agent. Group one (G1) was composed of seven animals that presented oronasal fistulae after the extraction of maxillary canine teeth compromised by severe periodontal disease. These fistulae were reduced by the double-mucoperiosteal-flap technique, 15 days after the dental extraction. Group two (G2) was composed of five other dogs that presented oronasal fistulae after the extraction of maxillary canine teeth compromised by severe periodontal disease. In this group, the fistulae were reduced by the single-flap technique, immediately after the dental extraction. Group three (G3) was composed of three animals, two of which presented oronasal fistulae due to maxillary fracture and the third one after excision of oral neoplasia. In all groups, simple interrupted sutures were used with 3.0 nylon, and a thin layer of self-curing glass ionomer cement was applied immediately over the operated area. After cement's settling time, a thin layer of photopolymerizable adhesive was applied to the already polymerized cement. In G1, the protective cement was removed on average at 15 (±2) postoperative days, in G2 at 6 (±1) days and in G3 at 11 (±9) days. In the postoperative period, the animals received antibiotics and anti-inflammatory drugs, and they received their usual dry dog food diet. No Elizabethan collar or any other protective measure was used for suturing or the surgical wound. The result was healing of 100% of the oronasal fistulae, without suture dehiscence or the need for new surgical interventions. Thus, it was concluded that the use of self-curing glass ionomer cement covered by photopolymerizable adhesive was fully satisfactory, providing protection of sutures and surgical wounds and showing the potential for routine use in oral surgery in dogs.

Individual, socioeconomic and healthcare access factors influencing the delays in leprosy presentation, diagnosis and treatment: a qualitative study.

BACKGROUND: This study investigated the factors influencing the presentation, diagnosis and treatment of leprosy in primary healthcare. METHODS: Qualitative research was conducted on patients undergoing treatment in a priority hyperendemic region for leprosy control in northeastern Brazil. Interviews were conducted between September and December 2020 at primary healthcare centers. Data were analysed based on the basic interpretive qualitative structure according to Andersen and Newman's model of healthcare utilisation. RESULTS: Knowledge of leprosy symptoms influenced patients' search for a diagnosis. Unfavorable socioeconomic conditions experienced by patients made diagnosis and treatment difficult. Incorrect evaluations by health professionals caused difficulties and delays in obtaining a diagnosis of leprosy. Perceptions about the disease, such as non-acceptance of the disease and the adverse effects of the medications, affected treatment seeking and treatment continuity. CONCLUSIONS: Patients with leprosy faced delays and healthcare access barriers related to knowledge of the disease, socioeconomic conditions and the structure of healthcare services, which must be considered when creating care plans, surveillance and control actions against leprosy. Appropriate interventions are necessary to reduce delays and better control the disease.

Highlighting COVID-19: What the imaging exams show about the disease.

Coronavirus disease 2019 (COVID-19), a global emergency, is caused by severe acute respiratory syndrome coronavirus 2. The gold standard for its diagnosis is the reverse transcription polymerase chain reaction, but considering the high number of infected people, the low availability of this diagnostic tool in some contexts, and the limitations of the test, other tools that aid in the identification of the disease are necessary. In this scenario, imaging exams such as chest X-ray (CXR) and computed tomography (CT) have played important roles. CXR is useful for assessing disease progression because it allows the detection of extensive consolidations, besides being a fast and cheap method. On the other hand, CT is more sensitive for detecting lung changes in the early stages of the disease and is also useful for assessing disease progression. Of note, ground-glass opacities are the main COVID-19-related CT findings. Positron emission tomography combined with CT can be used to evaluate chronic and substantial damage to the lungs and other organs; however, it is an expensive test. Lung ultrasound (LUS) has been shown to be a promising technique in that context as well, being useful in the screening and monitoring of patients, disease classification, and management related to mechanical ventilation. Moreover, LUS is an inexpensive alternative available at the bedside. Finally, magnetic resonance imaging, although not usually requested, allows the detection of pulmonary, cardiovascular, and neurological abnormalities associated with COVID-19. Furthermore, it is important to consider the challenges faced in the radiology field in the adoption of control measures to prevent infection and in the follow-up of post-COVID-19 patients.

Antibacterial nitric oxide-releasing polyester for the coating of blood-contacting artificial materials.

The emergence of multidrug-resistant bacteria associated with blood-contacting artificial materials is a growing health problem, which demands new approaches in the field of biomaterials research. In this study, a poly(sulfhydrylated polyester) (PSPE) was synthesized by the polyesterification reaction of mercaptosuccinic acid with 3-mercapto-1,2-propanediol and blended with poly(methyl methacrylate) (PMMA) from solution, leading to solid PSPE/PMMA films, with three different PSPE : PMMMA mass ratios. These films were subsequently S-nitrosated through the immersion in acidified nitrite solution, yielding poly(nitrosated)polyester/PMMA (PNPE/PMMA) films. A polyurethane intravascular catheter coated with PNPE/PMMA was shown to release nitric oxide (NO) in phosphate buffered saline solution (pH 7.4) at 37 degrees C at rates of 4.6 nmol/cm(2)/h in the first 6 h and 0.8 nmol/cm(2)/h in the next 12 h. When used to coat the bottom of culture plates, NO released from these films exerted a potent dose- and time-dependent antimicrobial activity against Staphylococcus aureus and a multidrug-resistant Pseudomonas aeruginosa strains. This antibacterial effect of PSPE/PMMA films opens a new perspective for the coating of blood-contacting artificial materials, for avoiding their colonization with highly resistant bacteria.

A pandemia de COVID-19 e casos de violência doméstica: percepções de profissionais da atenção primária à saúde no contexto de isolamento social / The COVID-19 pandemic and cases of domestic violence: perceptions of primary healthcare professionals in the context of social isolation / La pandemia de COVID-19 y la violencia doméstica: percepción de los profesionales de atención primaria de salud en el contexto del aislamiento social

Objetivo: analisar as percepções de profissionais da atenção primária à saúde de Paranaguá/PR sobre as relações entre a pandemia de COVID-19 e casos de violência doméstica em seus territórios adscritos, identificando desafios na abordagem, impactos nas famílias e manejo dos casos. Metodologia: pesquisa qualitativa com entrevistas semiestruturadas e grupos focais com 36 profissionais de duas unidades básicas de saúde de Paranaguá, litoral paranaense. Resultados: profissionais da atenção primária à saúde foram unânimes em relatar o aumento no número de casos de violência doméstica naquelas comunidades, com impactos tanto para mulheres, quanto para crianças e adolescentes, sendo o fechamento das escolas um fator agravante. Como principais desafios, foram reportados: a desestruturação da atenção primária à saúde durante o auge da pandemia com deslocamento de profissionais e recursos; desinformação sobre fluxos de encaminhamento nos casos de violência doméstica na rede intersetorial; medo dos profissionais, tanto da pandemia, quanto de denunciar casos de violência doméstica; e rotatividade de profissionais. Conclusão: o período de isolamento social causado pela pandemia intensificou os casos de violência doméstica segundo as percepções de profissionais da atenção primária à saúde de Paranaguá. O desmonte da rede intersetorial prejudicou ainda mais o cuidado de pessoas em situação de vulnerabilidade e/ou violência. A ausência de diretrizes nacionais do governo federal deixou municípios e profissionais da atenção primária à saúde à própria sorte para lidar com o problema.

Objective: to analyze the perceptions of primary health care professionals in Paranaguá/PR about the relationship between the COVID-19 pandemic and cases of domestic violence in their assigned territories, identifying challenges in the approach, impacts on families and case management. Methodology: qualitative research was conducted using semi-structured interviews and focus groups with 36 professionals from two primary health care units in Paranaguá, on the Paraná coast. Results: primary health care professionals unanimously reported an increase in the number of domestic violence cases in those communities, affecting women, children, and adolescents, with the closure of schools identified as an aggravating factor. The main challenges highlighted were the disruption of primary health care services during the peak of the pandemic due to the reallocation of professionals and resources; misinformation about referral processes for domestic violence cases within the intersectoral network; fear among professionals regarding the pandemic and reporting domestic violence cases; and high staff turnover. Conclusion: the period of social isolation caused by the pandemic intensified domestic violence cases, according to the perceptions of primary health care professionals in Paranaguá. The dismantling of the intersectoral network further compromised the care of individuals in situations of vulnerability and/or violence. The absence of national guidelines from the federal government left municipalities and primary health care professionals on their own to deal with the issue.

Objetivo: analizar las percepciones de los profesionales de la atención primaria de salud de Paranaguá/PR sobre las relaciones entre la pandemia de COVID-19 y los casos de violencia doméstica en sus territorios asignados, identificando desafíos en el abordaje, impactos en las familias y gestión de casos. Metodología: investigación cualitativa con entrevistas semiestructuradas y grupos focales con 36 profesionales de dos unidades básicas de salud de Paranaguá, en la costa de Paraná. Resultados: los profesionales de la atención primaria de salud fueron unánimes al reportar el aumento del número de casos de violencia doméstica en esas comunidades, con afectaciones tanto a mujeres, niños y adolescentes, siendo el cierre de escuelas un agravante. Se informaron los principales desafíos: la interrupción de la atención primaria de salud durante el apogeo de la pandemia con el desplazamiento de profesionales y recursos; desinformación sobre los flujos de derivación de casos de violencia doméstica en la red intersectorial; miedo entre los profesionales, tanto a la pandemia como a denunciar casos de violencia doméstica; y rotación profesional. Conclusión: el período de aislamiento social provocado por la pandemia intensificó los casos de violencia doméstica según la percepción de los profesionales de la atención primaria de salud en Paranaguá. El desmantelamiento de la red intersectorial perjudicó aún más la atención a personas en situación de vulnerabilidad y/o violencia. La ausencia de directrices nacionales por parte del gobierno federal dejó a los municipios y a los profesionales de atención primaria de salud a su suerte a la hora de abordar el problema.

Antithrombogenic polynitrosated polyester/poly(methyl methacrylate) blend for the coating of blood-contacting surfaces.

A nitric oxide (NO) donor polyester containing multiple S-nitrosothiol (S-NO) groups covalently attached to the polymer backbone was synthesized through the esterification of poly(ethylene glycol) with mercaptosuccinic acid, followed by the nitrosation of the -SH moieties. The polynitrosated polyester (PNPE) obtained was blended with poly(methyl methacrylate) (PMMA), yielding solid films capable of releasing NO. Scanning electron microscopy analysis showed that acrylic plates and stainless steel intracoronary stents can be coated with continuous and adherent PNPE/PMMA films. After an initial NO burst, these films release NO spontaneously in dry condition or immersed in aqueous solution at constant rates of 1.8 and 180 nmol/g/h, respectively, for more than 24 h at physiological temperature. PNPE/PMMA coated surfaces were shown to inhibit platelet adhesion when in contact with whole blood. These results show that PNPE/PMMA blend can be used for the coating of blood-contacting surfaces, with potential to inhibit thrombosis and restenosis after stenting.

Essential Elements as Biomarkers of Acute Kidney Injury and Spontaneous Reversion.

Acute kidney injury (AKI) is an important health problem and can be caused by number of factors. The use of aminoglycosides, such as gentamicin, is one of these factors. Recently, an effort has been made to find biomarkers to guide treatment protocols. Inductively coupled plasma optical emission spectroscopy (ICP-OES) was used to estimate the contents of Ca, Cu, Fe, K, Mg, Mn, Na, P, and Zn in serum and urine of the healthy, AKI, and spontaneous recovery (SR) groups of animals. The animal model of AKI and SR was validated by measuring serum and urinary urea and creatinine. The quantitative determination of the elements showed a decrease in serum levels of Ca, and Fe in the AKI group (P<0.01 vs. healthy), with a return to normal levels in the SR group, without a significant difference between the healthy and SR groups. In the urine samples, there was a decrease in P and Na levels in the AKI group (P<0.001 and P<0.01 vs. healthy), but Ca levels were increased in this group compared with the healthy and SR groups (P<0.01). These findings indicate that mineral elements might be useful as biomarkers for AKI.

Antibacterial activity of medicinal plants against Leptospira spp: a literature review / Actividad antibacteriana de plantas medicinales contra Leptospiraspp: una revisión de la literatura

Leptospirosis is a zoonosis caused by bacteria of the genus Leptospira that affects animals and humans. This disease is usually treated empirically due to its prevalence in precarious areas without basic sanitation. The use of medicinal plants in less industrializedsocieties has been one of the main therapeutic resources available. Considering the need to use these natural resources to combat leptospirosis in areas of socioeconomic vulnerability, this study aimed to review the literature on the use of plants with medicinal potential in the treatment of leptospirosis. The results showed that even though leptospirosis is a common disease in communities lacking basic sanitation and economic development, the number of studies on the use of plants with medicinal potential is scarce. Most of these studies come from India, and all plants investigated between 2012 and 2020 had antileptospiral action.

La leptospirosis es una zoonosis causada por bacterias del género Leptospira que afecta a animales y humanos. Esta enfermedad suele ser tratada empíricamente debido a su prevalencia en zonas precarias sin saneamiento básico. El uso de plantas medicinales en las sociedades menos industrializadas ha sido uno de los principales recursos terapéuticos disponibles. Considerando la necesidad de utilizar estos recursos naturales para combatir la leptospirosis en áreas de vulnerabilidad socioeconómica, este estudio tuvo como objetivo revisar la literatura sobre el uso de plantas con potencial medicinal en el tratamiento de la leptospirosis. Los resultados mostraron que a pesar de que la leptospirosis es una enfermedad común en comunidades que carecen de saneamiento básico y desarrollo económico, el número de estudios sobre el uso de plantas con potencial medicinal es escaso. La mayoría de estos estudios provienen de India, y todas las plantas investigadas entre 2012 y 2020 tuvieron acción antileptospirales.

Increase of angiotensin-converting enzyme activity and peripheral sympathetic dysfunction could contribute to hypertension development in streptozotocin-induced diabetic rats.

Diabetes augments the risk of hypertension. Although several factors have been implicated in the development of such hypertensive state, we designed this study to investigate blood pressure development, the activity of angiotensin-converting enzyme (ACE) in blood as well as sympathetic neurotransmission in the vas deferens of diabetic rats. We used streptozotocin (STZ)-induced diabetic rats (60 mg/kg) in order to evaluate the systolic blood pressure (SBP), ACE activity and peripheral sympathetic neurotransmission. We observed the following changes of parameters: increase of SBP, decrease of heart rate, augmentation of plasma ACE activity, enhancement of phasic and tonic vas deferens contractions elicited by electrical stimulation at 5 Hz, increase of maximal response to noradrenaline (NA) and decrease of adenosine triphosphate (ATP)-elicited contraction of vasa deferentia. The results reveal that in the development of hypertension in diabetic rats, augmentation of circulating ACE activity precedes the sympathetic dysfunction. Additionally, it seems that the purinergic and noradrenergic neurotransmission is compromised.

Hydrogel protection: a novel approach to reduce bowel inflammation in experimental gastroschisis.

OBJECTIVE: In gastroschisis there is herniation of the fetal bowel into the amniotic cavity that results in severe intestinal dysfunction. In order to reduce bowel exposure to amniotic fluid we used a hydrogel of N-isopropylacrylamide copolymerized with acrylic acid (P(NIPAAm-co-AAc)) to coat the herniated bowel through the use of a fibrin adhesive (Beriplast). STUDY DESIGN: Gastroschisis was created in fetuses of 31 pregnant Sprague-Dawley rats by evisceration of the bowel through a right paramedian incision in the abdominal wall on day 18.5 of pregnancy. The fetuses were separated in four groups of 12 fetuses: control (C), gastroschisis (G), gastroschisis+fibrin adhesive (GA) and gastroschisis+fibrin adhesive+dry hydrogel (GAH). Animals were harvested at day 21.5 of pregnancy and the hydrogel was removed. Fetuses and bowels were weighed and morphometric analysis was performed. Isoelectric focusing of the amniotic fluid determined its electrical charge. We evaluated the hydrogel swelling ratio (Q) in the amniotic fluid. Histological analysis and scanning electronic microscopy (SEM) of the bowel and hydrogel were performed. Our primary outcome was bowel intactness after hydrogel removal and our secondary outcome was the effectiveness of the hydrogel in protecting the bowel against amniotic fluid and its components. Differences among the groups were tested by the ANOVA and Tukey-Kramer post-test method and the statistical significance accepted was for p values <0.05. RESULTS: The mass of swollen hydrogel was 34 times the mass of dry hydrogel. Isoelectric focusing of the amniotic fluid showed that most of its proteins are negatively charged as the hydrogel. SEM showed that removal of the hydrogel did not damage bowel serosa. Bowel weight, diameter and wall thickness were similar between groups C and GAH but bowel diameter and wall thickness was significantly reduced in C and GAH compared to G and GA (p<0.001). CONCLUSION: The P(NIPAAm-co-AAc) hydrogel does not harm the bowel and provides a safe effective protection with reduction of bowel damage in gastroschisis.

Polynitrosated polyesters: preparation, characterization, and potential use for topical nitric oxide release.

New nitric oxide (NO) donor macromolecules, containing multiple S-nitrosothiol (S-NO) groups covalently attached to the polymer backbone, were prepared through the polycondensation reaction of diols (ethylene glycol and poly(ethylene glycol)) with mercaptosuccinic acid, followed by the S-nitrosation of the SH groups by a gaseous NO/O2 mixture. The polynitrosated polyesters (PNPEs) obtained were characterized by IR spectroscopy and gel permeation chromatography and displayed biological activity as vasodilators, leading to local hyperaemia when applied topically on healthy skin. Kinetic measurements in either dry or aqueous conditions have shown that PNPEs can provide sustained NO release for more than 20 h at physiological temperature. Their increased viscosity at low temperatures greatly reduces the rate of NO release, allowing for their storage for more than 90 days at -20 degrees C without decomposition. These results indicate that PNPEs have potential for topical delivery of NO in biomedical applications.

Changes in the relationship between society and nature in the Mezzo-region of Southeastern Pará, Amazon, Brazil

With this work, the authors wish to show some of the alterations in the pattern of relations between society and nature, which have taken place throughout the 20th century in the Parauapebas and Itacaiúnas river valleys, as well as in parts of the Tocantins River valley, in southeastern Pará. This is accomplished through descriptions based on Coudreau's first-hand accounts (1889), transcribed in "Voyage a Itaboca et a L'Itacayuna", published in 1897, which depicts an area almost totally covered by forest. This is followed by a counter view made possible through the LandSat 5 satellite sensors, with images of those valleys in 2001, showing the consequences of society transformations and pressure on natural resources, and above all the dramatic decrease in the size of the forest, reduced to 52 percent of the 63,000 square kilometers analyzed herein.

Neste texto, busca-se demonstrar algumas das alterações ocorridas nos padrões de relações existentes entre sociedade e natureza ocorridas no século XX, nos vales dos rios Parauapebas, Itacaiúnas e em parte do vale rio Tocantins, no sudeste do estado do Pará, o que é feito realizando um resgate das descrições decorrentes do olhar de Coudreau (1889) e transcritas em "Voyage a Itaboca et a L'Itacayuna", publicado em 1897, no qual se descreve uma área quase que integralmente coberta pela floresta. Em seguida, realiza-se uma contraposição, recorrendo a outro olhar, o que é viabilizado pelos sensores do satélite Landsat 5, que imagiaram a área destes vales em 2001, explicitando conseqüências das transformações da sociedade e da pressão sobre recursos naturais mas, sobretudo, a drástica redução da floresta a 52% dos 63 mil km² analisados.