Modelling and simulation of brinicle formation.

Below the Arctic sea ice, under the right conditions, a flux of icy brine flows down into the sea. The icy brine has a much lower fusion point and is denser than normal seawater. As a result, it sinks while freezing everything around it, forming an ice channel called a brinicle (also known as ice stalactite). In this paper, we develop a mathematical model for this phenomenon, assuming cylindrical symmetry. The fluid is considered to be viscous and quasi-stationary. The heat and salt transport are weakly coupled to the fluid motion and are modelled with the corresponding conservation equations, accounting for diffusive and convective effects. Finite-element discretization is employed to solve the coupled system of partial differential equations. We find that the model can capture the general behaviour of the physical system and generate brinicle-like structures while also recovering dendrite composition, which is a physically expected feature aligned with previous experimental results. This represents, to our knowledge, the first complete model proposed that captures the global structure of the physical phenomenon even though it has some discrepancies, such as brine accumulation.

Guilt and Shame of What Might Have Been in Optimistic Offender Drivers.

Habitual offender drivers are required to recover points lost on their driving license by attending reeducation courses, an experience that may, upon reflection of the incident in question, induce feelings of guilt or shame for the infractions they committed. A simulated driving task studied optimistic offender drivers to analyze the extent to which the controllability of the situational context influenced their use of internal and external factors in counterfactual thoughts and emotions such as guilt and shame. The study involved 160 drivers, of whom 54 were categorized as repeat offender drivers while 106 drivers attended courses for advanced professional driving licenses. The participants drove along a route in a driving simulator, which had been previously adjusted for the difficulty to generate a perception of high or low control. Based on the outcome obtained by the participants in this stage, each driver had to report which resources they required to improve their outcomes. Different factor ANOVAs were used to analyze our findings. The results indicated that optimistic offenders, unlike other groups (i.e., optimistic non-offender and pessimistic non-offender), thought that their results could have been better if external factors had been present (i.e., upward counterfactuals), both under conditions of high and low control. They believed their results would have been worse had it not been for their internal resources (i.e., downward counterfactuals), especially under conditions of low control. Concerning emotions of guilt and shame, offender optimists had the lowest values in both conditions compared with the other groups. We may contend that optimistic offender drivers thought they could have obtained better outcomes if external factors had been involved. In the low control condition, they justified that if it were not for such internal skills, their results could have been worse. When they generated such thoughts, the emotions of guilt and shame were minimal.

Retrospective investigation of the neutrophil-to-lymphocyte ratio in dogs with pneumonia: 49 cases (2011-2016).

OBJECTIVE: To assess the utility of the neutrophil-to-lymphocyte ratio (NLR) in predicting outcome in canine pneumonia compared with routine hematological parameters and systemic inflammatory response syndrome (SIRS) scores. DESIGN: Retrospective study. SETTING: University teaching hospital. ANIMALS: Forty-nine client-owned dogs. INTERVENTIONS: None MEASUREMENTS AND MAIN RESULTS: Medical records were reviewed to identify dogs with a diagnosis of pneumonia from July 2011 to December 2016. Signalment, clinical findings, laboratory characteristics, and outcome were recorded. Inclusion criteria were a clinical and radiographic diagnosis of pneumonia, plus reference laboratory hematology at diagnosis. Cases that received steroids were excluded. Euthanized dogs were only included in statistical analysis if euthanized solely due to pneumonia severity. The NLR, total WBC count, neutrophil count, lymphocyte count, band neutrophil percent of total WBC count (%-bands), and percentage of cases diagnosed with SIRS were compared between survivors and nonsurvivors. Receiver operating characteristic curves were generated to identify optimal sensitivity and specificity cutoffs for nonsurvival to discharge. Two hundred records were retrieved; 49 cases fulfilled the inclusion criteria. Of these, 33 (67%) survived to discharge. The NLR did not differ significantly between the survivors and nonsurvivors, nor did total WBC count or neutrophil count. Survivors had a significantly lower %-bands than nonsurvivors (P < 0.001) and higher lymphocyte count (P = 0.004). The mortality rate did not differ significantly between dogs with and without SIRS. Receiver operating characteristic analysis identified a %-bands cutoff of 2.5% or higher had an 83% sensitivity and 79% specificity for nonsurvival. CONCLUSIONS: Unlike in human medicine, neither NLR nor SIRS scores predicted outcome in this cohort of dogs with pneumonia. However, survivors had a lower %-bands and higher lymphocyte count than nonsurvivors, which may be helpful prognostically in clinical cases.

Effect of a preoperative single-dose steroid on pulmonary function and postoperative symptoms after modified radical mastectomy: results of a randomized clinical trial.

BACKGROUND: Evidence suggests that a preoperative single-dose steroid improves lung function and decreases the incidence of postoperative symptoms; however, this has not been sufficiently proved in modified radical mastectomy for cancer. This study aimed to evaluate the efficacy of preoperative single-dose steroid administration for postoperative lung function and postoperative symptoms in women undergoing modified radical mastectomy for breast cancer. METHODS: In this controlled clinical trial, conducted between June 2014 and October 2018, we examined 81 patients. Patients received a preoperative single dose of 8 mg dexamethasone (n=41; treatment group) or placebo (sterile injectable water; n=40; control group). We obtained data on postoperative nausea and vomiting and pain intensity and performed spirometry 1 h before and 1, 6, 12, and 24 h after surgery. The use of additional analgesic or antiemetic drugs was recorded. We followed up patients 30 days after discharge and recorded any surgical or medical complications. RESULTS: The age distribution and anthropometric variables of the two groups were similar. Almost 50% of the patients in each group also underwent breast reconstruction. In the treatment group, pain intensity was always lower, the incidence of postoperative nausea and vomiting was lower at 6, 12, and 24 h, and additional analgesics or antiemetics were required less frequently (P<0.05 for all). Both treatment and control groups demonstrated a restrictive ventilatory pattern immediately after surgery, which in the treatment group was reversed after 24 h. However, the reconstructed patients had a more intense and prolonged restrictive pattern (P<0.05). Surgical morbidity included one seroma observed in the control group. No infections occurred at the surgical site or at any other level, and no patient developed any metabolic disorder. No mortality was observed in either group. CONCLUSIONS: This study establishes that a single preoperative dose of dexamethasone markedly decreased the incidence of postoperative nausea and vomiting and pain, improved respiratory parameters, and decreased the need for additional postoperative analgesic or antiemetic drugs. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov (ID NCT02305173).

A Low-Cost Visible Light Positioning System for Indoor Positioning.

Currently, a high percentage of the world's population lives in urban areas, and this proportion will increase in the coming decades. In this context, indoor positioning systems (IPSs) have been a topic of great interest for researchers. On the other hand, Visible Light Communication (VLC) systems have advantages over RF technologies; for instance, they do not need satellite signals or the absence of electromagnetic interference to achieve positioning. Nowadays, in the context of Indoor Positioning (IPS), Visible Light Positioning (VLP) systems have become a strong alternative to RF-based systems, allowing the reduction in costs and time to market. This paper shows a low cost VLP solution for indoor systems. This includes multiple programmable beacons and a receiver which can be plugged to a smartphone running a specific app. The position information will be quickly and securely available through the interchange between the receiver and any configurable LED-beacon which is strategically disposed in an area. The implementation is simple, inexpensive, and no direct communication with any data server is required.

Topological population analysis and pairing/unpairing electron distribution evolution: Atomic B3+ cluster bending mode, a case study.

Local and non-local topological treatment of electronic distributions are applied to a simple out of equilibrium case of an electron-deficient three-atom cluster, B3+. The bending movement is described in detail through the onset and disappearance of critical points defining two kinds of molecular structures, characterizing a transition state (TS) and predicting two stable equilibrium geometries. All points in this rich evolution and the structural change in the out of equilibrium conformations has been featured and distinguished by the behavior of the population magnitudes and of the paired and unpaired electron densities within the non-local and local points of view of the topological formalism. The unpaired or electron hole density appears as relevant in both versions, the non-local or integrated one, in which it is sometimes called free-valence and also for its complementary counterpart, the local one, to describe and to quantify the interatomic interactions. The stability of the cluster B3+ is characterized in terms of a topologically defined ring structure and the highest total two- and three-center populations, thus showing the role of the geometry, the covalence, and the complex patterns. Consideration of the electron correlation effects constitutes the basement of the results gathered, thus displaying their influence in the formation and breaking of boron bonding interactions.

Associations between stressors and difficulty sleeping in critically ill patients admitted to the intensive care unit: a cohort study.

BACKGROUND: Patients admitted to the intensive care unit (ICU) experience sleep disruption caused by a variety of conditions, such as staff activities, alarms on monitors, and overall noise. In this study, we explored the relationship between noise and other factors associated with poor sleep quality in patients. METHODS: This was a prospective cohort study. We used the Richards-Campbell Sleep Questionnaire to explore sleep quality in a sample of patients admitted to the ICU of a private hospital. We measured the noise levels within each ICU three times a day. After each night during their ICU stay, patients were asked to complete a survey about sleep disturbances. These disturbances were classified as biological (such as anxiety or pain) and environmental factors (such as lighting and ICU noise). RESULTS: We interviewed 71 patients; 62% were men (mean age 54.46 years) and the mean length of stay was 8 days. Biological factors affected 36% and environmental factors affected 20% of the patients. The most common biological factor was anxiety symptoms, which affected 28% of the patients, and the most common environmental factor was noise, which affected 32.4%. The overall mean recorded noise level was 62.45 dB. Based on the patients' responses, the environmental factors had a larger effect on patients' sleep quality than biological factors. Patients who stayed more than 5 days reported less sleep disturbance. Patients younger than 55 years were more affected by environmental and biological factors than were those older than 55 years. CONCLUSIONS: Patient quality of sleep in the ICU is associated with environmental factors such as noise and artificial lighting, as well as biological factors related to anxiety and pain. The noise level in the ICU is twice that recommended by international guides. Given the stronger influence of environmental factors, the use of earplugs or sleeping masks is recommended. The longer the hospital stay, the less these factors seem to affect patients' sleep quality.

Total reversal of internal carotid blood flow in a patient with severe stenosis of the brachiocephalic trunk.

Occlusions and severe stenoses of the innominate artery (brachiocephalic trunk) are rare and present with a wide variety of clinical manifestations, with hemispheric, vertebrobasilar and right upper limb ischemic symptoms. The most common cause is atherosclerosis. Duplex scanning may show right vertebral artery flow reversal, diminished subclavian flow, and several patterns of right carotid flow disturbance, including slow flow, partial flow reversal during the cardiac cycle and even complete reversal of flow in the internal carotid artery, which is a very uncommon finding. Herein, the authors describe the case of a female patient who was a heavy smoker, had severe stenosis of the brachiocephalic trunk, and had episodes of collapse. Besides the subclavian steal and partial flow reversal in the common carotid artery, duplex scanning also showed high-velocity reversed flow in the internal carotid artery during the entire cardiac cycle, a finding that is not reported in the literature at this magnitude.

Compressibility of 2M1 muscovite-phlogopite series minerals.

Muscovite (Ms) and phlogopite (Phl) belong to the 2:1 dioctahedral and trioctahedral layer silicates, respectively, and are the end members of Ms-Phl series minerals. This series was studied in the 2M1 polytype and modeled by the substitution of three Mg2+ cations in the Phl octahedral sites by two Al3+ and one vacancy, increasing the substitution up to reach the Ms. The series was computationally examined at DFT level as a function of pressure to 9 GPa. Cell parameters as a function of pressure and composition, and bulk moduli as a function of the composition agrees with the existing experimental results. The mixing Gibbs free energy was calculated as a function of composition. From these data, approximated solvi were calculated at increasing pressure. A gap of solubility is found, decreasing the gap of solubility at high pressure.

Burnout syndrome prevalence during internship in public and private hospitals: a survey study in Mexico.

Burnout syndrome is a psychological condition that commonly affects health professionals, medical students, and others in professions with long shifts. It is defined by a high amount of emotional exhaustion, depersonalization, and low personal job satisfaction. We aimed to determine the prevalence of burnout syndrome in medical interns and establish the relationships between this condition and the time and type of hospital at which students worked during their medical internship. This was a survey study in which we used the Maslach Burnout Inventory, applied to fifth-year medical students on an internship at private and public hospitals in Mexico. The participants were 96 women (54.5%) and 80 men (45.5%), with ages ranging from 21 to 34 years old. We found burnout syndrome in 20% of these medical students 22% of the women and 18.6% of the men in the sample. Second-semester interns suffered burnout at a rate of 29%, in contrast to 15% of first-semester students. Emotional exhaustion and depersonalization scores were higher in second-semester interns who worked in public hospitals. However, the prevalence did not differ between public and private hospitals. Our study reports a higher prevalence of burnout syndrome during the second semester of internship. Students who practiced their internship in a public hospital showed higher scores in emotional exhaustion and depersonalization than those who practiced in a private hospital.

Sexuality Among Women Treated for Breast Cancer: A Survey of Three Surgical Procedures.

BACKGROUND: The quality of life of Mexican patients with breast cancer has been studied, but female sexual function has only been explored superficially. The Female Sexual Function Index (FSFI) questionnaire has been validated as a tool to measure sexual function among women with cancer. However, no study in Mexico has been published. PURPOSE: To evaluate and compare female sexuality of breast cancer survivors treated with three surgical procedures. MATERIALS AND METHODS: This is a cross-sectional questionnaire survey applied in patients without active disease and free of any oncologic treatment who underwent conservative mastectomy, and mastectomy with and without reconstruction. Patients included in this study had no evidence of active disease after at least 2 years of postoperative follow-up and agreed to complete the FSFI questionnaire during a surveillance visit. RESULTS: Seventy-four patients were included: 37.8% had undergone conservative mastectomy, 29.7% radical mastectomy, and 32.4% radical mastectomy plus reconstruction. Patients in the radical mastectomy group were older than those in the other groups (p = 0.002). Female sexual dysfunction was observed in 34% of patients, but in patients who underwent radical mastectomy, it was 63% by contrast with 14 and 29% in women treated with conservative mastectomy and radical mastectomy with reconstruction (p = 0.001). CONCLUSIONS: We found a lower prevalence of female sexual dysfunction in patients treated with conservative mastectomy or reconstruction after radical mastectomy. Alternatively, radical mastectomy was offered to older patients, a condition that could contribute together with a loss of female perception to a higher prevalence of sexual dysfunction. LEVEL OF EVIDENCE III: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

[A participatory model for addressing violence against women in La Araucanía, Chile]. / Modelo participativo para el abordaje de la violencia contra las mujeres en La Araucanía, Chile.

Violence against women is considered a public health problem that affects women worldwide. Recently, the Directing Council of the Pan American Health Organization declared its serious socioeconomic impact in the Region of the Americas and committed to undertaking actions in the health services to address this problem. Within that framework, this paper describes the steps of a participatory action research (PAR) approach that is being implemented in the Wenteche Territory of the La Araucanía region of Chile, which aims to strengthen community bonds, rekindle opportunities for dialogue with and among the people of the territory, foster social participation and democracy in the generation of pertinent, participatory knowledge regarding this problem, and obtain information to support design of an intervention model adapted to local characteristics.

Modelo participativo para el abordaje de la violencia contra las mujeres en La Araucanía, Chile / A participatory model for addressing violence against women in La Araucanía, Chile / Modelo participativo para abordagem da violência contra a mulher em La Araucanía, Chile

La violencia contra la mujer se considera un problema de salud pública que afecta a las mujeres en todo el mundo. Recientemente, el Consejo Directivo de la Organización Panamericana de la Salud declaró sus graves repercusiones sociales y económicas en la Región de las Américas y se comprometió a emprender acciones en los servicios de salud para afrontar el problema. En ese marco, se presentan los pasos de una investigación-acción-participativa (IAP), que se está desarrollando en el territorio wenteche de la región de La Araucanía de Chile, que apuesta por fortalecer los vínculos comunitarios, revalorizar los espacios de diálogo con y entre las personas del territorio, la participación social y la democracia en la generación de conocimientos pertinentes y participativos sobre este problema, y obtener información para diseñar un modelo de intervención que se adecúe a las características locales.

Violence against women is considered a public health problem that affects women worldwide. Recently, the Directing Council of the Pan American Health Organization declared its serious socioeconomic impact in the Region of the Americas and committed to undertaking actions in the health services to address this problem. Within that framework, this paper describes the steps of a participatory action research (PAR) approach that is being implemented in the Wenteche Territory of the La Araucanía region of Chile, which aims to strengthen community bonds, rekindle opportunities for dialogue with and among the people of the territory, foster social participation and democracy in the generation of pertinent, participatory knowledge regarding this problem, and obtain information to support design of an intervention model adapted to local characteristics.

A violência contra a mulher é um problema de saúde pública que atinge mulheres em todo o mundo. Recentemente, o Conselho Diretor da Organização Pan-Americana da Saúde reconheceu as sérias repercussões socioeconômicas do problema na Região das Américas e se comprometeu a realizar ações nos serviços de saúde para combatê-lo. Como parte deste enquadramento, são apresentadas as etapas de uma pesquisa-ação participativa sendo desenvolvida no território wenteche da região de La Araucanía, no Chile, que visa reforçar os vínculos na comunidade, revalorizar os espaços de diálogo com e entre os habitantes locais, a participação social e a democracia na geração de conhecimento pertinente e participativo sobre esta problemática e obter dados para a elaboração de um modelo de intervenção adequado às características locais.

Quality of life among women treated for breast cancer: a survey of three procedures in Mexico.

BACKGROUND: This study aimed to determine the quality of life among patients treated with one of three different types of surgery for breast cancer. METHODS: This cross-sectional study used a questionnaire survey completed by Mexican patients without active disease 1 year after breast cancer surgery. RESULTS: The 139 patients enrolled in the study included 44 (31.6 %) who had undergone mastectomy with reconstruction, 41 (29.5 %) who had undergone a quadrantectomy, and 54 (38.9 %) who had undergone radical mastectomy without reconstruction. The European Organization for Research and Treatment of Cancer Quality of Life Questionnaire, core version 30 (EORTC QLQ-C30) and EORTC Breast Quality-of-Life Questionnaire (QLQ-BR23) questionnaires were used. These instruments had a reliability greater than 0.82. Global health status (94.30 ± 12.04; p = 0.028) and role functioning (85.16 ± 17.23; p = 0.138) were highest in the quadrantectomy group. The pain score was highest in the group that had received mastectomy with reconstruction (26.13 ± 30.15; p = 0.042). The breast symptom score (22.56 ± 22.30; p = 0.009) and body image perception (85.56 ± 19.72; p = 0.025) were highest in the group that had conservative treatment. The overall health of the patients who had undergone mastectomy without reconstruction was lower (72.61 ± 20.89; p = 0.014) among the women older than 50 years than among the younger women. CONCLUSIONS: The quadrantectomy procedure had better acceptance, but the overall health status did not differ between the groups. The overall health status was lower among the women older than 50 years who had received a mastectomy without reconstruction.

Structure-properties relationships of lithium electrolytes based on ionic liquid.

Low-melting ionic liquid, IL, based on small aliphatic quaternary ammonium cations ([R(1)R(2)R(3)NR](+), where R(1), R(2), R(3) = CH(3) or C(2)H(5), R = C(3)H(7), C(4)H(9), C(6)H(13), C(8)H(17), CF(3)C(3)H(6)) and imide anion were prepared and characterized. The physicochemical and electrochemical properties of these ILs, including melting point, glass transition, and degradation temperatures; viscosity; density; ionic conductivity; diffusion coefficient; and electrochemical stability, were determined. Heteronuclear Overhauser NMR spectroscopy experiments were also performed to point out the presence of pair correlation between the different moieties. The LiTFSI addition effect on the IL properties was studied with the same methodology. Some nanoscale organization with segregation of polar and apolar domains was observed. ILs with small alkyl chain length or fluorinated ammonium exhibit very high electrochemical stability in oxidation.

Resistência tensional do pericárdio bovino fixado em glutaraldeído comparada com a da veia safena magna / Comparative analysis of rupture resistance between glutaraldehyde-treated bovine pericardium and great saphenous vein

CONTEXTO: O uso do pericárdio bovino como remendo na endarterectomia de carótida é uma alternativa à veia safena magna. As vantagens do pericárdio incluem facilidade de obtenção, menor tempo operatório e principalmente menor índice de ruptura. OBJETIVO: Avaliar a resistência tensional do pericárdio bovino tratado com glutaraldeído e compará-la com a da veia safena magna. MÉTODOS: Os remendos de pericárdio bovino (grupo I, n = 20) e de veia safena magna (grupo II, n = 20) foram recortados em dimensões iguais (50 x 5 mm) e preparados de modo habitual a sua utilização. Os grupos foram submetidos a ensaio de tração e comparados em relação a força de ruptura, força máxima e tensão de ruptura utilizando-se o teste t de Student. A correlação da espessura do remendo com a força de ruptura também foi analisada utilizando-se o coeficiente de correlação linear de Pearson. RESULTADOS: Os parâmetros força de ruptura e força máxima foram significativamente maiores no grupo dos remendos de pericárdio bovino: 1,97 versus 1,36 kgf (p = 0,001230) e 2,27 versus 1,51 kgf (p = 0,0001087), respectivamente. A tensão de ruptura média para o material pericárdio bovino também foi maior (193,99±43,05 versus 49,19±22,96 kgf/cm², p = 7,603e-16) do que na veia safena. A correlação entre a espessura e a força de ruptura foi considerada moderada (r = 0,5032993) para o pericárdio bovino e baixa (r = 0,3062166) para o grupo da veia safena. CONCLUSÃO: Os autores concluem que a resistência do pericárdio bovino à ruptura foi considerada adequada neste estudo, e é significativamente maior que a da veia safena magna, retirada da região da coxa. Além disso, a espessura do remendo em ambos os grupos não apresenta boa correlação com sua resistência a ruptura.

BACKGROUND: Carotid endarterectomy using bovine pericardium is an acceptable alternative to great saphenous vein patch. Bovine pericardium is easily obtained and provides a shorter operative time and lower rupture rate. OBJECTIVE: To evaluate rupture resistance of glutaraldehyde-treated bovine pericardium patch in comparison with great saphenous vein patch. METHODS: The sample was divided into two groups: bovine pericardium patch (group I, n = 20) and great saphenous vein patch (group II, n = 20). Both bovine pericardium and saphenous vein patches were prepared in the same dimensions (50 mm x 5 mm) and tested using standard procedures. The patches were tested in the longitudinal axis until the point of material failure. The following parameters were addressed: failure force, ultimate force and failure stress. Statistical analysis was conducted using the Student t test and Pearson's linear correlation. RESULTS: Failure force and ultimate force parameters were significantly higher in the bovine pericardium patch group: 1.97 vs. 1.36 kgf (p = 0.001230) and 2.27 vs. 1.51 kgf (p = 0.0001087), respectively. Mean failure stress in the bovine pericardium patch group was also significantly higher than that in the great saphenous vein group (193.99±43.05 vs. 49.19±22.96 kgf/cm², p = 7.603e-16). The correlation between thickness and failure force was considered moderate (r = 0.5032993) for the bovine pericardium group and low (r = 0.3062166) for the great saphenous vein group. CONCLUSION: The failure stress related to the bovine pericardium group was considered appropriate in this study, and was significantly higher than that observed in the great saphenous vein group. In addition, patch thickness in both groups did not show a good correlation with rupture resistance.

Cirurgia de varizes dos membros inferiores em pacientes receptores de transplante hepático: relato de caso / Surgical treatment of varicose veins of the lower limbs in liver transplant recipients: a case report

O transplante hepático vem progressivamente apresentando melhores resultados e maior preocupação com a qualidade de vida dos pacientes. As varizes dos membros inferiores são comuns na população e causam sintomas em boa parte dos casos, comprometendo a qualidade de vida. Em pacientes com boa condição clínica e funcionamento normal do enxerto, o tratamento cirúrgico das varizes de membros inferiores pode ser a opção com resultado mais eficaz e duradouro. Os autores relatam dois casos de pacientes que haviam sido submetidos a transplante hepático e apresentavam varizes sintomáticas de membros inferiores, e foram submetidos a cirurgia de varizes após liberação pela equipe de transplante hepático. As operações ocorreram sem intercorrências, com bom resultado no seguimento. A cirurgia de varizes dos membros inferiores pode ser realizada com segurança em pacientes receptores de transplante hepático, sendo uma opção eficaz e duradoura no tratamento da insuficiência venosa crônica nesses pacientes.

Liver transplantation is having progressively better outcomes, and quality of life is being more often addressed. Varicose veins of the lower limbs are common in the general population and cause symptoms in a significant number of cases, impairing quality of life. For patients in good clinical condition, with adequate graft function, surgical treatment for varicose veins of the lower limbs can be a safe option, with more effective and longer lasting outcomes. The authors report two cases of liver transplant recipients who had symptomatic varicose veins of the lower limbs and were submitted to varicose vein surgery following authorization from the liver transplantation team. Operations were uneventful, with good follow-up results. Surgery for varicose veins of the lower limbs can be safely performed in liver transplant recipients, and it is an effective and long lasting treatment for chronic venous insufficiency in these patients.

One-electron oxidized nickel(II) complexes of bis and tetra(salicylidene) phenylenediamine Schiff bases: from monoradical to interacting Ni(III) ions.

The nickel(II) complexes of the mono and di-nucleating Schiff base ligands H(2)L(OMe), H(2)L(NO2) and H(4)L(bis) respectively were synthesized and characterized. H(2)L(OMe) and H(2)L(NO2) differ from one another by the substituents of the phenylene spacer, electron-donating methoxy or electron-withdrawing nitro groups respectively. X-Ray crystal structure analysis shows that the nickel(II) ion(s) resides within a square planar geometry in each complex. Cyclic voltammetry curves reveal that the electrochemical communication is strongly influenced by the substituent and the solvent. The one-electron oxidized species [Ni(L(OMe))](+) in CH(2)Cl(2) is a phenoxyl radical with partial delocalization of the spin density on a metal orbital (contribution of 6.8%), whereas [Ni(L(NO2))](+) was found to disproportionate once it is generated. A shift of electronic hole is observed in the presence of pyridine: both [Ni(L(OMe))](+) and the one-electron oxidation product of [Ni(L(NO2))] are converted into mononuclear octahedral nickel(III) complexes involving two axially bound pyridines. In the dinickel(II) complex of H(4)L(bis), namely [Ni(2)(L(bis))], the phenylene spacer mediates an electronic communication between the two metallic sites. Single oxidation of [Ni(2)(L(bis))] affords the delocalized phenoxyl radical [Ni(2)(L(bis))](+), whose EPR signature is close to that of [Ni(L(OMe))](+). Double oxidation affords the bis-{Ni(II)-delocalized radical} species [Ni(2)(L(bis))](2+). Each radical is located at a distinct metallic site and a weak but appreciable magnetic interaction exists between the paramagnetic centres. In the presence of pyridine, a complex involving two ferromagnetically coupled nickel(III) ions is obtained. The magnetic coupling has been estimated to 3.7 cm(-1), while the zero field splitting parameters are |D| = 0.012 cm(-1) and E = 0. They are weak, in agreement with the large intermetallic distance (7.7 A) observed in the neutral precursor [Ni(2)(L(bis))].

Galactose oxidase models: insights from 19F NMR spectroscopy.

(19)F labelled tripodal ligands that possess a N(3)O donor set (one phenol, one tertiary amine and either two pyridines or one pyridine and one quinoline) have been synthesized. The fluorine is incorporated either at the phenol O-donor (HL(F) and HL(CF3)) or at the quinoline N-donor (HLq(OMe) and HLq(NO2)). The copper(ii)-phenol complexes (2H)(2+), (1H)(2+), (3H)(2+) and (4H)(2+) as well as the corresponding copper(ii)-phenolate complexes have been characterized. X-Ray diffraction reveals an increase in the oxygen-copper bond distance of more than 0.4 A upon protonation of the phenolate moiety of (4)(+). Protonation is accompanied by an axial to equatorial isomerization of the quinoline group. DFT calculations show that stretching of the Cu-O(phenol) bond, pi-stacking interactions and rotation of the pyridine are key steps in this isomerization process. Protonation, and thus changes in the oxygen-copper bond distance induce either a decrease ((1H)(2+), (2H)(2+)) or an increase ((3H)(2+) and (4H)(2+)) in the copper-fluorine distance that could be monitored by (19)F NMR. In the former case, a broadening of the (19)F NMR signal is observed, whereas a sharpening is observed in the latter case. Temperature dependent (19)F NMR measurements on equimolar mixtures of the phenol and phenolate complexes of (3)(+) and (4)(+) reveal rate constants for proton transfer and/or isomerization of 3000 +/- 100 s(-1) and 2900 +/- 100 s(-1), respectively, at the coalescence temperature. This temperature was found to be strongly affected by the phenol para-substituent as it is 226 K and ca. 330 K for (3)(+) and (4)(+), respectively. A phenoxyl radical species ((3 )(2+)) could be generated and characterized for the first time by (19)F NMR spectroscopy.

A versatile electronic hole in one-electron oxidized NiIIbis-salicylidene phenylenediamine complexes.

The nickel complexes 1(+)-3(+) exhibit a delocalized radical character, the extent of which depends on the electronic properties of the phenolate para-substituent.