Nanoscale structural and electronic properties of cellulose/graphene interfaces.

The development of electronic devices based on the functionalization of (nano)cellulose platforms relies upon an atomistic understanding of the structural and electronic properties of a combined system, cellulose/functional element. In this work, we present a theoretical study of the nanocellulose/graphene interfaces (nCL/G) based on first-principles calculations. We find that the binding energies of both hydrophobic/G (nCLphob/G) and hydrophilic/G (nCLphil/G) interfaces are primarily dictated by the van der Waals interactions, and are comparable with those of their 2D interface counterparts. We verify that the energetic preference of nCLphob/G has been reinforced by the inclusion of an aqueous medium via an implicit solvation model. Further structural characterization was carried out using a set of simulations of the carbon K-edge X-ray absorption spectra to identify and distinguish the key absorption features of the nCLphob/G and nCLphil/G interfaces. The electronic structure calculations reveal that the linear energy bands of graphene lie in the band gap of the nCL sheet, while depletion/accumulation charge density regions are observed. We show that external agents, i.e., electric field and mechanical strain, allow for tunability of the Dirac cone and charge density at the interface. The control/maintenance of the Dirac cone states in nCL/G is an important feature for the development of electronic devices based on cellulosic platforms.

Heterosis in hybrids within and between yeast species.

The performance of hybrids relative to their parents is an important factor in speciation research. We measured the growth of 46 Saccharomyces yeast F1 interspecific and intraspecific hybrids, relative to the growth of each of their parents, in pairwise competition assays. We found that the growth of a hybrid relative to the average of its parents, a measure of mid-parent heterosis, correlated with the difference in parental growth relative to their hybrid, a measure of phenotypic divergence, which is consistent with simple complementation of low fitness alleles in one parent by high fitness alleles in the other. Interspecific hybrids showed stronger heterosis than intraspecific hybrids. To manipulate parental phenotypic divergence independently of genotype, we also measured the competitive growth of a single interspecific hybrid relative to its parents in 12 different environments. In these assays, we not only identified a strong relationship between parental phenotypic divergence and mid-parent heterosis as before, but, more tentatively, a weak relationship between phenotypic divergence and best-parent heterosis, suggesting that complementation of deleterious mutations was not the sole cause of interspecific heterosis. Our results show that mating between different species can be beneficial, and demonstrate that competition assays between parents and offspring are a useful way to study the evolutionary consequences of hybridization.

Chitosan nanoparticles for nitric oxide delivery in human skin.

The use of nanoparticle-based transdermal delivery systems is a promising approach to efficiently carry and deliver therapeutic agents for dermal and systemic administration. Nitric oxide (NO) is a key molecule that plays important roles in human skin such as the control of skin homeostasis, skin defense, control of dermal blood flow, and wound healing. In addition, human skin contains stores of NO derivatives that can be mobilized and release free NO upon UV irradiation with beneficial cardiovascular effects, for instance the control of blood pressure. In this work, the NO donor precursor glutathione (GSH) was encapsulated (encapsulation efficiency of 99.60%) into ultra-small chitosan nanoparticles (CS NPs) (hydrodynamic size of 30.65 ± 11.90 nm). GSH-CS NPs have a core-shell structure, as revealed by atomic force microscopy and X-ray photoelectron spectroscopy, in which GSH is protected in the nanoparticle core. Nitrosation of GSH by nitrous acid led to the formation of the NO donor S-nitrosogluthathione (GSNO) into CS NPs. The GSNO release from the CS NPs followed a Fickian diffusion described by the Higuchi mathematical model. Topical application of GSNO-CS NPs in intact human skin significantly increased the levels of NO and its derivatives in the epidermis, as assayed by confocal microscopy, and this effect was further enhanced by skin irradiation with UV light. Therefore, NO-releasing CS NPs are suitable materials for transdermal NO delivery to local and/or systemic therapies.

Livedoid vasculopathy - a challenging disease.

We present a rare association of idiopathic livedoid vasculopathy (LV) with peripheral sensory neuropathy successfully treated with intravenous immunoglobulin and warfarin and, after its failure, with rituximab. Although LV aetiology remains incompletely understood, the excellent clinical response observed in our patient suggests that B cells may be key players in its pathogenesis.

A multi-objective optimization approach accurately resolves protein domain architectures.

MOTIVATION: Given a protein sequence and a number of potential domains matching it, what are the domain content and the most likely domain architecture for the sequence? This problem is of fundamental importance in protein annotation, constituting one of the main steps of all predictive annotation strategies. On the other hand, when potential domains are several and in conflict because of overlapping domain boundaries, finding a solution for the problem might become difficult. An accurate prediction of the domain architecture of a multi-domain protein provides important information for function prediction, comparative genomics and molecular evolution. RESULTS: We developed DAMA (Domain Annotation by a Multi-objective Approach), a novel approach that identifies architectures through a multi-objective optimization algorithm combining scores of domain matches, previously observed multi-domain co-occurrence and domain overlapping. DAMA has been validated on a known benchmark dataset based on CATH structural domain assignments and on the set of Plasmodium falciparum proteins. When compared with existing tools on both datasets, it outperforms all of them. AVAILABILITY AND IMPLEMENTATION: DAMA software is implemented in C++ and the source code can be found at http://www.lcqb.upmc.fr/DAMA. CONTACT: juliana.silva_bernardes@upmc.fr or alessandra.carbone@lip6.fr SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

Neurological damage arising from intrapartum hypoxia/acidosis.

Complications occurring at any level of foetal oxygen supply will result in hypoxaemia, and this may ultimately lead to hypoxia/acidosis and neurological damage. Hypoxic-ischaemic encephalopathy (HIE) is the short-term neurological dysfunction caused by intrapartum hypoxia/acidosis, and this diagnosis requires the presence of a number of findings, including the confirmation of newborn metabolic acidosis, low Apgar scores, early imaging evidence of cerebral oedema and the appearance of clinical signs of neurological dysfunction in the first 48 h of life. Cerebral palsy (CP) consists of a heterogeneous group of nonprogressive movement and posture disorders, frequently accompanied by cognitive and sensory impairments, epilepsy, nutritional deficiencies and secondary musculoskeletal lesions. Although CP is the most common long-term neurological complication associated with intrapartum hypoxia/acidosis, >80% of cases are caused by other phenomena. Data on minor long-term neurological deficits are scarce, but they suggest that less serious intellectual and motor impairments may result from intrapartum hypoxia/acidosis. This chapter focuses on the existing evidence of neurological damage associated with poor foetal oxygenation during labour.

Impact of the introduction of fetal central monitoring on hospital expenses with cardiotocographic paper.

Digital storage of cardiotocographic (CTG) tracings by fetal central monitoring systems (fCMS) obviates the need for printing, or alternatively, the tracings can be printed in regular paper instead of CTG thermal paper. We aimed at evaluating the impact of the introduction of the Omniview-SisPorto(®) system on CTG paper costs in a large university hospital. After introduction of the fCMS, there was an 87% reduction in median annual expenses with CTG paper in the labour ward (p = 0.011) and a 78% decrease in the prenatal clinic (p = 0.017), despite a more than 40% increase in the median number of observed women. Routine use of fCMS may provide an important reduction in hospital expenses associated with the use of thermal CTG paper, thus reducing the investment made in their acquisition and maintenance.

Knowledge of adverse neonatal outcome alters clinicians' interpretation of the intrapartum cardiotocograph.

OBJECTIVE: To evaluate the impact of knowledge of neonatal outcome on clinicians' interpretation of the intrapartum cardiotocograph (CTG). DESIGN: Prospective evaluation of pre-recorded cases. SETTING: Five maternity hospitals. POPULATION: From a database of intrapartum CTGs acquired with a scalp electrode in singleton near-term fetuses, 20 tracings were sequentially selected from cases with newborn umbilical artery pH < 7.05 and 20 from cases with pH > 7.20. METHODS: Five experienced obstetricians practising in different maternity hospitals were asked to analyse the 40 tracings individually, according to the International Federation of Gynaecology and Obstetrics guidelines. In a first round, clinicians were given no information on neonatal outcome. In a second round, carried out 2 months later, clinicians were asked to analyse the same tracings, but the order was randomly altered and information on the newborn's arterial pH was provided. Clinicians were not informed of the purpose of the study or whether the tracings were the same. MAIN OUTCOME MEASURES: The incidence of individual fetal heart rate feature identification and tracing classification, before and after neonatal outcome was made available. RESULTS: In the group with pH < 7.05, repetitive decelerations and reduced variability were more common in the second round (P < 0.001 and P = 0.001, respectively), as was a pathological classification (P = 0.002); variable decelerations were less common (P = 0.008). In the group with normal pH, less tracings in the second round had prolonged decelerations (P = 0.013) and no accelerations (P = 0.013), but more had pronounced decelerations (P = 0.031) and reduced variability (P = 0.007); there was a reduction in pathological classifications, but this difference failed to reach statistical significance (P = 0.051). CONCLUSIONS: A knowledge of adverse neonatal outcome leads to a more severe classification of the intrapartum CTG, which derives mainly from the evaluation of decelerations and variability.

Access to computerised analysis of intrapartum cardiotocographs improves clinicians' prediction of newborn umbilical artery blood pH.

OBJECTIVE: To evaluate the impact of access to computerised cardiotocograph (CTG) analysis on reproducibility and accuracy of clinicians' predictions of umbilical artery blood pH (UAB pH) and 5-minute Apgar score. DESIGN: Prospective evaluation of pre-recorded cases. SETTING: A tertiary-care university hospital. POPULATION: From databases of intrapartum CTGs acquired in singleton term pregnancies, 204 tracings with low signal loss and short time interval to delivery were consecutively selected. METHODS: Tracings were randomly assigned to computer analysis by the Omniview-SisPorto 3.5 system (study group n = 104) or to no analysis (control group n = 100). Three experienced clinicians evaluated all tracing printouts independently and were asked to predict the newborns' UAB pH and 5-minute Apgar scores from them. MAIN OUTCOME MEASURES: Interobserver agreement (measured by the intraclass correlation coefficient [ICC]) and accuracy in prediction of neonatal outcomes with 95% CI. RESULTS: Agreement on prediction of UAB pH was significantly higher in the study group (ICC = 0.70; 95% CI 0.61-0.77) than in the control group (ICC = 0.43; 95% CI 0.21-0.60), and a trend towards better agreement was also seen in estimation of 5-minute Apgar scores (ICC = 0.55; 95% CI 0.38-0.68 versus ICC = 0.43; 95% CI 0.25-0.57). Observers predicted UAB pH values correctly within a 0.10 margin in 70% of cases in the study group (95% CI 0.61-0.79) versus 46% in the control group (95% CI 0.35-0.56). They predicted 5-minute Apgar scores within a margin of one in 81% of cases in the study group (95% CI 0.73-0.88) and in 70% of cases in the control group (95% CI 0.61-0.79). CONCLUSIONS: Prediction of UAB pH is more reproducible and accurate when clinicians have access to computerised analysis of CTGs.

Amyloidosis secondary to rheumatic diseases - 16 cases.

INTRODUCTION: Secondary amyloidosis (SA) results of tissue deposition of an acute phase reactant protein produced by chronic inflammation. Its incidence appears to be declining, following the improvement of medical care to primary diseases. Our aim is to assess a group of Portuguese patients with amyloidosis secondary to inflammatory rheumatic diseases, and their evolution over the past 10 years. METHODS: The study comprised 16 patients with SA confirmed by tissue biopsy, hospitalized in the Rheumatology Department of Hospital São João in Oporto in the last 10 years. We made a protocol on epidemiological, clinical and analytical data focusing the rheumatic disease and SA, and possible elements of connection between them. RESULTS: Of the 16 patients, mainly women (81,2%), with mean age at entry of 56 years, 68,8% had rheumatoid arthritis. Amyloidosis was diagnosed in average at 13,5 years of primary rheumatic disease, and its main manifestation was kidney involvement, which together with infection and orthopaedic surgery or its complications, were the leading causes of hospitalization. In this time interval, 6 patients died. They were older, with longer duration and lower rate of treatment of the primary rheumatic disease, and had SA diagnosed 1,5 years before death (different of the 5 years of those that still alive). They had higher rate of gastrointestinal, neurological and serious kidney involvement, and hospitalizations. CONCLUSIONS: Improving medical care in rheumatic inflammatory diseases has reduced the incidence of SA. Also, biotherapy appears to be achieving positive results in established amyloidosis, whatever the mechanisms involved. Our data, on Portuguese patients, seems to follow this trend.

Case report: intra-partum utero-ovarian vessels rupture.

CASE: We report the rare case of a 39-year-old woman who had an intra-partum hemoperitoneum that resulted from spontaneous rupture of the utero-ovarian vessels. During the expulsive efforts, the patient repeatedly complained of bilateral shoulder discomfort and some respiratory difficulty. Because she had hemodynamic instability and an abdomino-pelvic ultrasound revealed the presence of extensive free fluid within the peritoneal cavity, the patient underwent an exploratory laparotomy. The surgery revealed an extensive laceration of the anterior leaf of the left broad ligament and vesico-uterine peritoneum, and active bleeding from the utero-ovarian vessels with no evidence of uterine rupture. CONCLUSION: Intra-partum haemoperitoneum resulting from rupture of the utero-ovarian vessels is a rare obstetrical emergency that needs rapid resuscitation with fluid and/or blood replacement and prompt surgical intervention.

Mechanical properties of polypropylene mesh used in pelvic floor repair.

The aim of this study was the comparison of the stiffness of different meshes under two types of mechanical tests. Five different mesh types were mechanically tested. The methods used consisted on uniaxial tension test (tensile stiffness) and tape ring tests, experimental continuous compression of the mesh loops (flexural stiffness). The most significant difference of tensile stiffness behaviour appears between Aris and TVTO. From the analysis of the experimental data, we divided the flexural stiffness, in two main groups. The first group includes Auto Suture and Aris meshes. The two meshes seem to have a similar flexural behaviour. The second group includes TVTO, Uretex and Avaulta. The difference between these two groups is clearly evident comparing TVTO and Aris. This study shows that there are significant differences on the mechanical properties between urogynecology meshes.

Impact of labor and delivery simulation classes in undergraduate medical learning.

UNLABELLED: INTRODUCATION: The aim of this study was to evaluate the impact on knowledge and learner satisfaction of adding a labour and delivery simulator-based training module versus a self-study session to the pre-existing theoretical class, in the 5(th) year undergraduate medical curriculum. METHODS: One hundred and fifty seven students attending the 5-week Obstetrics and Gynecology rotation were enrolled, and 107 completed the study. After a 90-minute "labour and delivery" theoretical interactive class, students were randomized to two groups: the first (n = 56) participated in a 30-minute supervised self-study session, while the second (n = 51) attended a 20-30 minute delivery simulator session. Tests consisting of 10 multiple-choice questions were taken before the theoretical class (pre-test), after the self-study or simulation session (1(st) post-test) and 12-15 days later (2(nd) post-test). A subgroup of 53 students participating in this study (27 from the simulation and 26 from the self-study arm) answered six additional questions on satisfaction with the learning experience, at the time of the 1(st) post-test. Wilcoxon paired rank sum test, Wilcoxon T test, and z-statistic with continuity correction were employed for statistical analysis, setting significance at p < 0.05. RESULTS: Pre-test scores were similar in both groups (p = 0.9567), but in the first post-test they were significantly higher in the simulation group (p = 0.0017). In the 2(nd) post-test, scores were again similar in both groups (p = 0.2204). Satisfaction was significantly higher in the simulation group (p < 0.0001). CONCLUSIONS: Adding a simulator-based training session for medical students in management of labour and delivery to the theoretical class led to a higher short-term increase in knowledge and student satisfaction than attending a self-study session. Significant differences in knowledge were no longer demonstrable at 12-15 days.

[Systemic lupus erythematosus: imaging of central nervous system involvement by magnetic resonance]. / Lupus eritematoso sistémico: a ressonância magnética no envolvimento do sistema nervoso central.

UNLABELLED: Patients with systemic lupus erythematosus (SLE) can develop dysfunction of the central nervous system (CNS) and have several neurologic syndromes with heterogeneous pathogenic mechanisms. The most common neurologic manifestations of SLE are organic mental syndromes, functional psychoses and seizures. METHODS: We retrospectively reviewed the magnetic resonance imaging (MRI) of SLE patients with CNS involvement followed in S. João Hospital Rheumatology clinic. Only patients with abnormal MRI were selected. RESULTS: In 42 patients studied there were 22 (52,4%) cases with abnormal MRI. Patient's age ranged between 20 and 63 years (mean 35,6). All were females. MRI showed multiple periventricular white matter lesions in 16 cases (68,2%) and cerebral infarctions in 3 cases (13,6%). There were atrophic changes in 4 cases (18,2%) and cerebral hemorrhage in 2 cases (9,1%). There was a case (4,5%) of transverse myelitis associated with acute optic neuritis (Devic's syndrome) and 1 case (4,5%) of predominantly posterior white matter signal abnormalities (reversible posterior leukoencephalopathy syndrome). CONCLUSION: This study confirms MRI importance on in identifying and characterizing CNS abnormalities, which contributes to better investigation and management of these patients. The authors discuss etiological possibilities of the different imagiological findings.

Development of foetal and neonatal simulators at the University of Porto.

BACKGROUND: Human error can be expected to play a significant role in adverse outcomes in perinatal acute care. In acute care of the adult, simulator based training is recommended and used to improve patient safety. AIMS: Our general goal is to develop model-driven foetal and neonatal educational simulators and curricula. The specific objectives of this paper are to introduce the reader to the perinatal acute care context and simulator design considerations, as well as to give initial results and describe ongoing developments. A brief description of adult simulators and simulation engines is followed by a more detailed description of a foetal distress simulator (FDS) and of models for a neonatal simulator developed at the University of Porto. Ongoing developments involve the modelling of foetal baroreflexes, the effect of uterine contractions, and an adapted method for estimating foetal heart rate variability parameters. RESULTS: We present FDS simulation results reflecting the changes in oxygen supply to the foetus and the foetal heart rate in response to a reduction in uterine blood flow. We also present a structural diagram of a model for the educational simulation of congenital heart disease and preliminary simulation results reflecting a patent ductus arteriosus. CONCLUSION: We expect that, after initial clinical and educational validation, the presented models and simulators will play a role in simulator-based educational programmes contributing to increased perinatal safety.

The effect of tamoxifen on PCNA expression in fibroadenomas.

For almost three decades, tamoxifen has been used in the adjuvant treatment of breast cancer. It has also proven effective in the chemoprophylaxis of this disease and in the treatment of cyclic mastalgia. Since a fibroadenoma is a benign hormone-dependent neoplasm which contains estrogen receptor (ER) levels higher than in the mammary lobule, an evaluation of the effect of this drug on the proliferative activity of both the epithelium and the stroma of fibroadenomas in premenopausal women following the administration of 10 or 20 mg/day over 22 days was proposed. Forty women with fibroadenoma were selected for a randomized double-blind trial. They had regular menstrual cycles and had received neither hormones nor become pregnant 12 months prior to this study. Patients were divided into three groups: A (n = 14; placebo), B (n = 13; tamoxifen 10 mg/day), and C (n = 13; tamoxifen 20 mg/day). The treatment was initiated on the first day of their menstrual cycle and the surgeries were performed on the 22nd day. Estradiol, progesterone, and steroid hormone binding globulin (SHBG) were measured twice. The first measurement was performed on the 22nd day of the previous menstrual cycle and the second one was performed on the day of surgery. The fibroadenoma was fixed in 10% formaldehyde solution and stained with hematoxylin and eosin and then processed through immunohistochemical reaction (PC-10, DAKO code number M879, Denmark A/S). The immunoexpression of the proliferative cell nuclear antigen (PCNA) of at least 500 epithelial and 500 stromal cells was evaluated. Such cells were interactively counted using the Kontron Imaging System KS-300 computerized analysis system, with x 400 magnification. As to PCNA expression in the fibroadenomas' epithelium, the average percentage of stained nuclei in groups A, B, and C was 25.2, 19.3, and 18.0, respectively. However, no significant difference was found in the variance analysis of these data (p = 0.168). As to the study of the fibroadenomas' stroma, the average percentage of stained nuclei found in groups A, B, and C was 32.4, 23.2, and 18.4, respectively. The variance analysis (p = 0.031) and Fisher's multiple comparison test (1.39; 26.67 confidence interval [CI]) confirmed that the number of PCNA-expressing nuclei in the stroma was significantly lower in group C (20 mg/day) compared to group A (control). However, there was no significant difference between group B (10 mg/day) and group C (20 mg/day). It was found that tamoxifen reduced the expression of PCNA in the epithelium and the stroma of the fibroadenoma. However, the effect was only statistically significant in the stroma when a 20 mg/day dose was administered.