Optical spectrum of bottom-up graphene nanoribbons: towards efficient atom-thick excitonic solar cells

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Giro lamo Savonarola and forms of government.

The work presents an analytical study of the theme of the forms of government in the political thought of Girolamo Savonarola, based on his Thatawo circa il regimento e governo dela cimi. di Firenze (1498). Using Bobbio's methodology, the theme is analyzed from three simultaneous perspectives: the systematical, the axiological, and the teleological.

Uncommon crown-root fracture treated with adhesive tooth fragment reattachment: 7 years of follow-up

Crown-root fractures account for 5% of all fractures in permanent teeth and can involve enamel, dentin, and cementum. Depending on whether there is pulpal involvement, these problems may be classified as complicated (which are more common) or noncomplicated. The treatment depends on the level of the fracture line, root length and/or morphology, and esthetic needs. Several treatment strategies are available for esthetic and functional rehabilitation in crown-root fractures. Adhesive tooth fragment reattachment is the most conservative restorative option when the tooth fragment is available and the biological width has no or minimal violation. This article reports a case of an uncomplicated crown-root fracture in the permanent maxillary right central incisor of a young patient who received treatment with adhesive tooth fragment reattachment, preserving the anatomic characteristics of the fractured tooth after periodontal intervention. The fracture line of the fragment had an unusual shape, starting on the palatal side and extending to the buccal side subgingivally. After 7 years, the attached coronal fragment remained in position with good esthetics, as well as clinical and radiographic signs of pulpal vitality, periodontal health, and root integrity, thus indicating success.

Vascular dementia: Different forms of vessel disorders contribute to the development of dementia in the elderly brain

The diagnosis of vascular dementia (VaD) describes a group of various vessel disorders with different types of vascular lesions that finally contribute to the development of dementia. Most common forms of VaD in the elderly brain are subcortical vascular encephalopathy, strategic infarct dementia, and the multi infarct encephalopathy. Hereditary forms of VaD are rare. Most common is the cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). Sporadic forms of VaD are caused by degenerative vessel disorders such as atherosclerosis, small vessel disease (SVD) including small vessel arteriosclerosis, arteriolosclerosis, and lipohyalinosis, and cerebral amyloid angiopathy (CAA). Less frequently inflammatory vessel disorders and tumor-associated vessel lesions (e. g. angiocentric T-cell or angiotropic large cell lymphoma) can cause symptoms of dementia. Here, we review and discuss the impact of vessel disorders to distinct vascular brain tissue lesions and to the development of dementia in elderly individuals. The impact of coexisting neurodegenerative pathology in the elderly brain to VaD as well as the correlation between SVD and CAA expansion in the brain parenchyma with that of Alzheimer's disease (AD)-related pathology is highlighted. We conclude that "pure" VaD is rare and most frequently caused by infarctions. However, there is a significant contribution of vascular lesions and vessel pathology to the development of dementia that may go beyond tissue damage due to vascular lesions. Insufficient blood blow and alterations of the perivascular drainage mechanisms of the brain may also lead to a reduced protein clearance from extracellular space and subsequent increase of proteins in the brain parenchyma, such as the amyloid beta-protein, and foster, thereby, the development of AD-related neurodegeneration. As such, it seems to be important for clinical practice to consider treatment of potentially coexisting AD pathology in cognitively impaired patients with vascular lesions. (C) 2012 Elsevier Inc. All rights reserved.

Effect of Brazil Nut Supplementation on Plasma Levels of Selenium in Hemodialysis Patients: 12 Months of Follow-up

Background: Large amounts of reactive oxygen species are produced in hemodialysis (HD) patients, and, at higher concentrations, reactive oxygen species are thought to be involved in the pathogenesis of cardiovascular disease. It has been proposed that selenium (Se) may exert an antiatherogenic influence by reducing oxidative stress. The richest known food source of Se is the Brazil nut (Bertholletia excelsa, family Lecythidaceae), found in the Amazon region. Objective: The objective of this work was to determine if Se plasma levels in HD patients submitted to a program of supplementation during 3 months with 1 Brazil nut by day could be sustained after 12 months. Methods: A total of 21 HD patients (54.2 +/- 15.2 years old; average time on dialysis, 82.3 +/- 51.6 months; body mass index, 24.4 +/- 3.8 kg/m(2)) from the RenalCor Clinic in Rio de Janeiro, Brazil, were followed up 12 months after the supplementation study ended. The Se plasma levels were determined by atomic absorption spectrophotometry with hydride generation. Results: The Se Plasma levels (17.3 +/- 19.9 mg/L) were below the normal range (60 to 120 mu g/L) before nut supplementation, and after 3 months of supplementation, the levels increased to 106.8 +/- 50.3 mu g/L (P < .0001). Twelve months after supplementation, the plasma Se levels decreased to 31.9 +/- 14.8 mu g/L (P < .0001). Conclusions: The data showed that these patients were Se deficient and that the consumption of Brazil nut was effective to increase the Se parameters of nutritional status. Se levels 12 months after the supplementation period were not as low as presupplementation levels but yet significantly lower, and we needed to motivate patients to adopt different dietary intake patterns. (C) 2012 by the National Kidney Foundation, Inc. All rights reserved.

Proinflammatory and oxidative stress markers in patients submitted to Roux-en-Y gastric bypass after 1 year of follow-up

BACKGROUND/OBJECTIVES: This study examined the effect of weight loss after 3, 6 and 12 months of Roux-en-Y Gastric Bypass (RYGB) on energy intake and on several biomarkers of oxidative stress such as levels of vitamin C, beta-carotene, vitamin E (diet/blood), nitric oxide metabolites (NOx), myeloperoxidase (MPO), thiobarbituric acid reactive substances (TBARS), reduced glutathione (GSH) and activity of catalase (CAT). SUBJECTS/METHODS: Study with a control group (CG), assessed once, and a bariatric group (BG) assessed at the basal period as well as at 3, 6 and 12 months post-surgery; both groups were composed of 5 men and 31 women (n = 36). Age was 38.7 +/- 9.4 and 39.6 +/- 9.2 years old and body mass index (BMI) was 22.2 +/- 2.1 and 47.6 +/- 9.1 kg/m(2), respectively. The variance measure quoted was SEM. RESULTS: The body weight at 12 months was 35.8 +/- 1.0% (P<0.001) lower than that of the basal period. At the basal period BG showed higher levels of NOx (P=0.007) and TBARS (P<0.001) and lower levels of vitamins C and E (P<0.001) compared with CG. After 3 months the activity of MPO was decreased (P<0.001). Six months after surgery GSH levels were decreased (P=0.037), whereas CAT activity was increased (P=0.029). After 12 months levels of NOx (P=0.004), TBARS (P<0.001), beta-carotene (P<0.001) and vitamin E (P<0.001) were decreased, whereas those of vitamin C (P<0.001) were increased compared with controls. CONCLUSION: RYGB followed by a daily vitamin supplement apparently attenuated pro-inflammatory and oxidative stress markers 1 year after surgery, but additional antioxidant supplementation appears necessary.

Accuracy of Timed Up and Go Test for screening risk of falls among community-dwelling elderly

Objective: To determine the accuracy of the Timed Up and Go Test (TUGT) for screening the risk of falls among community-dwelling elderly individuals. Method: This is a prospective cohort study with a randomly by lots without reposition sample stratified by proportional partition in relation to gender involving 63 community-dwelling elderly individuals. Elderly individuals who reported having Parkinson's disease, a history of transitory ischemic attack, stroke and with a Mini Mental State Exam lower than the expected for the education level, were on a wheelchair and that reported a single fall in the previous six months were excluded. The TUGT, a mobility test, was the measure of interested and the occurrence of falls was the outcome. The performance of basic activities of daily living (ADL) and instrumental activities of daily living (IADL) was determined through the Older American Resources and Services, and the socio-demographic and clinical data were determined through the use of additional questionnaires. Receiver Operating Characteristic Curves were used to analyze the sensitivity and specificity of the TUGT. Results: Elderly individuals who fell had greater difficulties in ADL and IADL (p<0.01) and a slower performance on the TUGT (p=0.02). No differences were found in socio-demographic and clinical characteristics between fallers and non- fallers. Considering the different sensitivity and specificity, the best predictive value for discriminating elderly individuals who fell was 12.47 seconds [(RR= 3.2) 95% CI: 1.3- 7.7]. Conclusions: The TUGT proved to be an accurate measure for screening the risk of falls among elderly individuals. Although different from that reported in the international literature, the 12.47 second cutoff point seems to be a better predictive value for Brazilian elderly individuals.

Spectroscopic Study on the Structural Differences of Thermally Induced Cross-Linking Segments in Emeraldine Salt and Base Forms of Polyaniline

This paper reports the spectroscopic study on the structural differences of thermally induced cross-linking segments in polyaniline in its emeraldine salt (PANI-ES) and base (PANI-EB) forms. Casting films of PANI-ES (ES-film) and PANI-EB (EB-film) were prepared and heated at 150 degrees C under atmospheric air for 30 min. Raman spectra excited at 632.8 nm of heated ES-film presented the characteristic bands of phenazine-like structures at 1638, 1392, and 575 cm(-1), whereas EB-film showed lower relative intensities for these bands. The lower content of phenazine-like segments in heated EB-film is related to residual polaronic segments from preparation procedures, as revealed by Raman. This statement was confirmed by a sequence of thermal and doping experiments in both films. Quantum-chemical calculations by density functional theory (DFT) and time-dependent density functional theory (TD-DFT) showed that the phenazine-like structure presents the intense Raman band at 1350 cm(-1) due to heterocycle breathing mode, and the non-phenazine-like structure (substituted hydrophenazine-type) presents higher energy for HOMO-LUMO transition, indicating the lack of conjugation in the heterocycle compared with the phenazine-like structure. According to experimental and theoretical data reported here, it is proposed that only thermally treated PANI-ES presents phenazine-like rings, whereas PANI-EB presents heterocyclic non-aromatic structures.

A study of pent-up demand in ophthalmology: Divinolandia Hospital/Unicamp

Objective: To assess the waiting time for eye care identifying the number of patients with each complaint; to investigate how the waiting time may worsen the patient's condition; to check the screening of urgent cases for effectiveness; and to devise means of increasing the medical-surgical care capacity. Methods: A retrospective descriptive survey was conducted using data obtained on 12 occasions during collaborative team visits to provide eyecare services. These initiatives were designed to decrease the waiting time and to treat urgent cases that occurred on each occasion; eyecare services were provided every Saturday, in the period from June to August 2006, in 16 cities of the region covered by Conderg (Consortium for the Development of the Sao Joao da Boa Vista Administrative Region). Results: Referrals used 1,743 (87.1%) of the 2,000 places available. The most frequent diagnoses were refractive errors, with 683 cases, corresponding to 39.1% of the total, followed by cataracts, with 296 cases, corresponding to 20.9%. Of the 238 surgeries indicated, 54.6% were phakectomies. Thirty-five (2.0%) cases were considered urgent. Conclusion: The most common diagnoses made during the team visits to manage the excess demand for eyecare were refractive errors and cataracts, which, together, accounted for the majority of the cases. The Divinolandia Hospital has the necessary human and material resources to meet the demand left unattended by the local SUS network. Immediate referral of urgent cases by the primary units' screeners proved effective.

A study of pent-up demand in ophthalmology: Divinolândia Hospital/Unicamp

OBJECTIVE: To assess the waiting time for eye care identifying the number of patients with each complaint; to investigate how the waiting time may worsen the patient's condition; to check the screening of urgent cases for effectiveness; and to devise means of increasing the medical-surgical care capacity. METHODS: A retrospective descriptive survey was conducted using data obtained on 12 occasions during collaborative team visits to provide eyecare services. These initiatives were designed to decrease the waiting time and to treat urgent cases that occurred on each occasion; eyecare services were provided every Saturday, in the period from June to August 2006, in 16 cities of the region covered by Conderg (Consortium for the Development of the São João da Boa Vista Administrative Region). RESULTS: Referrals used 1,743 (87.1%) of the 2,000 places available. The most frequent diagnoses were refractive errors, with 683 cases, corresponding to 39.1% of the total, followed by cataracts, with 296 cases, corresponding to 20.9%. Of the 238 surgeries indicated, 54.6% were phakectomies. Thirty-five (2.0%) cases were considered urgent. CONCLUSION: The most common diagnoses made during the team visits to manage the excess demand for eyecare were refractive errors and cataracts, which, together, accounted for the majority of the cases. The Divinolândia Hospital has the necessary human and material resources to meet the demand left unattended by the local SUS network. Immediate referral of urgent cases by the primary units' screeners proved effective.

The role of empirical research in the study of complex forms of governance in agroindustrial systems

The growing complexity of supply chains poses new challenges for Agricultural Research Centers and statistical agencies. The aim of this perspective paper is to discuss the role of empirical research in understanding the complex forms of governance in agribusiness. The authors argue that there are three fundamental levels of analysis: (i) the basic structure of the market, (ii) the formal contractual arrangements that govern relations within the agroindustrial system and (iii) the transactional dimensions governed by non-contractual means. The case of the agrochemical industry in Brazil illustrates how traditional analyses that only address market structure are insufficient to fully explain the agricultural sector and its supply chain. The article concludes by suggesting some indicators which could be collected by statistical agencies to improve understanding of the complex relationships among agribusiness segments. In doing so, the paper seeks to minimize costs and to enable a better formulation of public and private policies.

Understanding the solid forms of 5E-phenylethenylbenzofuroxan with different in vivo anti-T. cruzi activity

5E-Phenylethenylbenzofuroxan (5PhEBfx) was reported as an excellent anti-Chagas drug candidate. However, its oral bioavailability was affected by the crystallization process. Two samples exhibiting variable in vivo activity was investigated: a thin yellow powder (5PhEBfx-Y) and orange needles (5PhEBfx-O). X-ray powder diffraction, differential scanning calorimetry, vibrational spectroscopy, optical and electron scanning microscopies were applied to investigate both solid forms in order to correlate the solid-state properties with the variable bioavailability of 5PhEBfx. It was observed that 5PhEBfx-Y have a better solubility and consequently higher bioavailability when compared with 5PhEBfx-O. This result suggests that the difference of activity between these two 5E-Phenylethenylbenzofuroxanes could be associated with the solid forms, which also cause the coloration variation.

Each one teaches one: characterizing active forms of proteins by single molecule force spectroscopy

This Ph.D. candidate thesis collects the research work I conducted under the supervision of Prof.Bruno Samor´ı in 2005,2006 and 2007. Some parts of this work included in the Part III have been begun by myself during my undergraduate thesis in the same laboratory and then completed during the initial part of my Ph.D. thesis: the whole results have been included for the sake of understanding and completeness. During my graduate studies I worked on two very different protein systems. The theorical trait d’union between these studies, at the biological level, is the acknowledgement that protein biophysical and structural studies must, in many cases, take into account the dynamical states of protein conformational equilibria and of local physico-chemical conditions where the system studied actually performs its function. This is introducted in the introductory part in Chapter 2. Two different examples of this are presented: the structural significance deriving from the action of mechanical forces in vivo (Chapter 3) and the complexity of conformational equilibria in intrinsically unstructured proteins and amyloid formation (Chapter 4). My experimental work investigated both these examples by using in both cases the single molecule force spectroscopy technique (described in Chapter 5 and Chapter 6). The work conducted on angiostatin focused on the characterization of the relationships between the mechanochemical properties and the mechanism of action of the angiostatin protein, and most importantly their intertwining with the further layer of complexity due to disulfide redox equilibria (Part III). These studies were accompanied concurrently by the elaboration of a theorical model for a novel signalling pathway that may be relevant in the extracellular space, detailed in Chapter 7.2. The work conducted on -synuclein (Part IV) instead brought a whole new twist to the single molecule force spectroscopy methodology, applying it as a structural technique to elucidate the conformational equilibria present in intrinsically unstructured proteins. These equilibria are of utmost interest from a biophysical point of view, but most importantly because of their direct relationship with amyloid aggregation and, consequently, the aetiology of relevant pathologies like Parkinson’s disease. The work characterized, for the first time, conformational equilibria in an intrinsically unstructured protein at the single molecule level and, again for the first time, identified a monomeric folded conformation that is correlated with conditions leading to -synuclein and, ultimately, Parkinson’s disease. Also, during the research work, I found myself in the need of a generalpurpose data analysis application for single molecule force spectroscopy data analysis that could solve some common logistic and data analysis problems that are common in this technique. I developed an application that addresses some of these problems, herein presented (Part V), and that aims to be publicly released soon.