ClO-driven degradation of graphene oxide: new insights from DFT calculations.

We present an extensive investigation using density functional theory (DFT) calculations on various model graphene oxide (GO) nanostructures interacting with chlorine monoxide ClO, aiming to understand the role of this highly oxidizing species in C-C bond breakage and the formation of significant holes on GO sheets. During its function, the myeloperoxidase (MPO) enzyme abundantly generates chlorine-oxygen-containing species and their presence has been identified as the cause of degradation in carbon nanotubes of diverse sizes, morphologies, and chemical compositions, both in in vivo and in vitro samples. Notably, Kurapati et al. (Small, 2015, 11, 3985-3994) demonstrated efficient degradation of single GO monolayers through MPO catalysis, though the exact degradation mechanism remains unclear. In our study, we discover that breaking C-C bonds in a single graphene oxide sheet is achievable through a simple mechanism involving the dissociation of two ClO molecules that are chemically attached as nearest neighbor species but bonded to opposite sides of the GO layer (up/down configuration). Two new carbonyl oxygens appear on the surface and the Cl atoms can be transferred to the carbon layer or as physisorbed species near the GO surface. Relatively small energy barriers are associated with these molecular events. Continuing this process on neighboring sites leads to the presence of larger holes on the GO surface, accompanied by an increase in carbonyl species on the carbon network, consistent with X-ray photoelectron spectroscopy measurements. Indeed, the distribution of oxygen functionalities is found to be crucial in defining the damage pattern induced in the carbon layer. We emphasize the important role played by the local charge distribution in the stability or instability of chemical bonds, as well as in the energy barriers and reaction pathways. Finally, we explore the possibility of achieving chlorination of GO following MPO exposure. The here-reported predictions could be the root cause of the experimentally observed low stability of individual GO sheets during the MPO catalytic cycle.

Influence of Taper surface topographies on contact deformation and stresses.

The role of bore and trunnion surface topography on the failure rate of total hip joint replacements due to trunnionosis is not clear despite significant variations in the design of taper components between manufacturers. Taper surface topography, along with other taper design parameters such as clearance, diameter, and assembly force, determine the initial interlock of the contacting surfaces after assembly; this has been related to relative motions that can cause fretting and corrosion at the taper interface. However, in most in-silico parametrical taper studies associated with taper micromotions, the bore and trunnion surfaces have been simplified using a flat surface and/or sinusoidal functions to mimic the surface roughness. The current study tests the hypothesis that the use of simple geometrical functions for the taper surface topography can predict the surface mechanics developed in assembled tapers. Measured and simulated surfaces of bores and trunnions were characterised using common roughness parameters and spectral density estimations. Using the same characterised surface profiles, 2D Finite Element (FE) models of CoCr alloy femoral heads and Ti alloy trunnions were developed. Models simulated assembly conditions at different resultant forces ranging from 0.5 to 4.0 kN, contact conditions were determined and associated with their topographical characteristics. Measured surfaces of bore and trunnion components comprise up to seven dominant spatial frequencies. Flattening of the trunnion microgrooved peaks was observed during the assembly of the taper. When the femoral head bore and trunnion topography were both considered a reduced number of microgrooved peaks were in contact, from 51 in an idealised taper surfaces to 35 in measured surfaces using an assembly reaction force of 4 kN. The contact points in the models developed high plastic strains, which were greater than that associated with failure of the material. Results showed that line and sine wave functions over estimate contact points at the taper interface compared to those surfaces that consider roughness and peak variation. These findings highlight the important role of modelling the full surface topography on the taper contact mechanics, as surface variations in the roughness and waviness change the performance of tapers.

N 1s core-level binding energies in nitrogen-doped carbon nanotubes: a combined experimental and theoretical study.

We report a combined experimental and theoretical study dedicated to analyze the N 1s core-level binding energies (CLBE) in N-doped carbon nanotubes (N-CNTs). X-ray photoelectron spectroscopy (XPS) data are obtained from N-CNT samples synthesized using the chemical vapor deposition technique. Extensive density functional theory (DFT) calculations are performed on various model single- and double-walled N-CNTs where N 1s CLBEs are determined using Koopman's theorem. However, we also present additional calculations within the (Z + 1) approximation to analyze the role of final-state effects. From XPS data up to 2 at% of N content was found in our samples and the high resolution analysis of the N 1s line shows, according to previous experimental results, that N species exist in CNTs as graphitic, pyrrolic, pyridinic, and molecular configurations. However, peak decomposition is characterized by five broad Gaussian curves that overlap considerably among them, having different widths and heights, implying a more complex distribution of N atoms within the structures. DFT calculations performed on model N-CNTs reveal a strong dependence of N 1s CLBE values and their shifts on the local atomic environment. Different types of graphitic N cover an energy range of 3 eV, while various configurations for pyridinic, pyrrolic, and molecular species reveal a dispersion in their energy values of 5.7, 2.7, and 5.2 eV, respectively. The previous distributions of theoretical CLBEs also strongly overlap, implying that some peaks in the XPS spectra must be understood as composite signals where the signals of different N defects coexist. We find, in agreement with the experimental data, that freestanding molecular nitrogen and (weakly interacting) encapsulated N2 within the hollow core of model CNTs have very similar CLBEs. Furthermore, we predict that chemisorbed N2 on defective regions of the nanotube walls has N 1s binding energy values that are considerably larger when compared to encapsulated N2, thus making possible their identification. In contrast to previous reports, we find a nontrivial dependence between CLBEs and the local electronic occupation at N sites. The assignment of spectral details in the XPS data to well-defined N-defects on CNTs is not straightforward and needs to be more deeply analyzed.

Randomized and Open Trial to Assess the Effectiveness of the Guided Pelvic Floor Exercises Pre-Radical Robotic Prostatectomy on the Improvement of Urinary Incontinence. Initial Results

Introduction and Objectives: Radical prostatectomy has an impact on urinary continence. Many factors are involved in continence. The objective of this study is evaluate the effect of guided Pelvic Floor Exercises prior to robotic radical prostatectomy (RRP) on the rate of urinary incontinence compared with written information. Material and Method: randomized study of 62 patients who are waiting for PRR. They were rondomized in two groups: experimental group (exercises guided by a physiotherapist) or a control group (written information). Primary objective was the continence rate measured by pad test and ICIQ-SF one month after the intervention, Secondary objectives were incontinence severity, quality of life with SF-36 and KHQ questionnaires and the correlation between incontinence and quality of life. Results: We found no differences in continence rate between groups after the intervention. We found differences in “emotional problems” and “personal relationships”, in favor of the control group. There is a correlation between the amount of urine leakage and age, urgency and all the domains of the KHQ questionnaire except general quality of life, as well as in the areas “energy/fatigue” and “social function” of the SF-36. Conclusions: Physiotherapist-guided exercises before RRP do not seem to offer advantages compared to written information, in terms of the incontinence rate and its severity one month after the surgery. Urinary incontinence is correlated with age, urgency, and deterioration in quality of life (AU)

Introducción y Objetivos: La prostatectomía radicaltiene un gran impacto en la continencia urinaria. Muchosfactores intervienen en la continencia. El objetivo de esteestudio es evaluar el efecto en la tasa de incontinencia deorina de los Ejercicios de Suelo Pélvicos guiados previos ala prostatectomía radical robótica (PRR), frente a la información escrita.Material y Método: Ensayo clínico en el que se incluyen 62 pacientes en lista de espera para PRR, aleatorizándolos a un grupo experimental (ejercicios guiados porfisioterapeuta) o control (información escrita). El objetivoprimario fue la tasa de continencia medida por test de compresa y el cuestionario ICIQ-SF al mes de la intervención,Fueron objetivos secundarios, la severidad de incontinencia, la calidad de vida con cuestionarios SF-36 y KHQ, y lacorrelación entre la incontinencia y la calidad de vida.Resultados: No encontramos diferencias en la tasade incontinencia entre los grupos tras la intervención. Encontramos diferencias en “problemas emocionales” y “relaciones personales”, a favor del grupo control. Existe correlación entre la cantidad de las pérdidas de orina y la edad,la urgencia miccional y todos los dominios del cuestionarioKHQ excepto la calidad de vida general, así como en lasáreas “energía/fatiga” y “función social” del SF-36.Conclusiones: Los ejercicios guiados por fisioterapeuta antes de PRR no parecen ofrecer ventajas frente ala información escrita, en la tasa de incontinencia y severidad de la misma al mes de la intervención. La incontinenciade orina se correlaciona con la edad, la urgencia miccionaly el deterioro en la calidad de vida. (AU)

Influence of taper design and loading on taper micromotion.

Debris originating at the bore-trunnion interface of modular total hip replacements has been identified as one of the causes of hip replacements failure. Friction associated with fretting and corrosion represents a potential generator of these harmful particles. Understanding the motions at the interface will help to interpret the different damage patterns found in retrieval studies and minimize the risk of fluid ingress/egress into the taper interface. Accordingly, the present study is designed to characterise the nature of the relative motions generated at the bore-trunnion interface of different taper designs during typical loading profiles. 3D Finite Element (FE) models of a CoCr femoral head assembled onto a Ti alloy trunnion were generated and variables including taper clearance, deviation from roundness, assembly force and loading conditions were introduced. Resulting micromotions relative to the trunnion surface, separation and contact area of the bore-trunnion interface were shown to be affected by both taper design and types of activities. Results indicated that, in some cases, the largest component of motion corresponded to that developed normal to the trunnion surface. Furthermore, out of roundness as small as 6 µm across the diameter, in particular orientations, significantly changed the contact mechanics and magnitude of relative motions. From the resulting parameters at the bore-trunnion interface, a pump type of motion was identified during walking, jogging and stairs up activities. The components of relative motions at the bore-trunnion interface were found to be different regardless of the resultant magnitude of the relative motions. The findings highlight the importance of high-quality manufacturing processes as small changes in the trunnion component will significantly affect the clinical performance of this common type of modular approach in total hip replacements.

PPARß/δ-dependent MSC metabolism determines their immunoregulatory properties.

Mesenchymal stem cell (MSC)-based therapy is being increasingly considered a powerful opportunity for several disorders based on MSC immunoregulatory properties. Nonetheless, MSC are versatile and plastic cells that require an efficient control of their features and functions for their optimal use in clinic. Recently, we have shown that PPARß/δ is pivotal for MSC immunoregulatory and therapeutic functions. However, the role of PPARß/δ on MSC metabolic activity and the relevance of PPARß/δ metabolic control on MSC immunosuppressive properties have never been addressed. Here, we demonstrate that PPARß/δ deficiency forces MSC metabolic adaptation increasing their glycolytic activity required for their immunoregulatory functions on Th1 and Th17 cells. Additionally, we show that the inhibition of the mitochondrial production of ATP in MSC expressing PPARß/δ, promotes their metabolic switch towards aerobic glycolysis to stably enhance their immunosuppressive capacities significantly. Altogether, these data demonstrate that PPARß/δ governs the immunoregulatory potential of MSC by dictating their metabolic reprogramming and pave the way for enhancing MSC immunoregulatory properties and counteracting their versatility.

Abdominal Aortic Aneurysm Complicated With Aorto-Left Retroaortic Renal Vein Fistula.

We present the case of a male with a fistula from an infrarenal aortic aneurysm to the left renal vein resolved with an endovascular prosthesis. Few cases have been reported in the literature.

First report on natural infection with Leishmania infantum in a domestic ferret (Mustela putorius furo) in Spain.

A pet domestic ferret (Mustela putorius furo) with a papular lesion involving the right pinna was diagnosed with chronic pyogranulomatous dermatitis by histopathologic examination. Intralesional, intracytoplasmic oval microorganisms compatible with Leishmania spp. or Histoplasma spp. were observed in macrophages and multinucleate giant cells. Leishmania infantum (L. infantum) infection was diagnosed by PCR, culture in Novy-MacNeal-Nicolle medium, and immunohistochemistry. Abnormal clinicopathological results included increased alanine transferase, alkaline phosphatase, serum gamma glutamyl transferase and polyclonal gammpathy. Anti-Leishmania antibodies were detected by enzyme-linked immunosorbent assay, immunofluorescence antibody test and western blot using L. infantum antigen. Immunoreactivity against the 16 kDa specific L. infantum antigen fraction was observed by western blot. PCR performed in blood samples obtained from this patient after positive parasite isolation detected L. infantum DNA. To the authors' knowledge, this is the first diagnosis and isolation of L. infantum in a domestic ferret naturally infected in an endemic region (Spain) where canine and feline leishmaniosis is frequently detected. According to these findings, ferrets should be included as potential reservoir hosts of L. infantum. Future investigations should analyze the epidemiological role of ferrets in L. infantum infection including the prevalence of infection.

Nanotubols under H2O2 exposure: is it possible to poly-hydroxylate carbon nanotubes?

We present a combined experimental and theoretical study dedicated to analyze the variations in the surface chemistry of hydroxylated multiwalled carbon nanotubes (MWCNTs), so called nanotubols, when exposed to H2O2 at high temperatures. The formation, surface density, and distribution of oxygen-containing functional groups are studied by infrared (IR) and X-ray photoelectron spectroscopy (XPS), as well as density functional theory (DFT) calculations performed on model functionalized carbon nanotubes (CNTs). After H2O2 exposure, the initial composition of -OH, -C[double bond, length as m-dash]O, and -COOH substituents notably changes, with carbonyl -C[double bond, length as m-dash]O groups being the ones that show the most notable increase on the carbon surface. Our highly oxidized MWCNTs are partially soluble and form complex two-dimensional patterns at the air-water interface, as evidenced by Brewster angle microscopy. In a second step, these films can be transferred to solid substrates to form porous multilayered carbon nanostructures with complex morphologies. In particular, and for the first time, we report the synthesis of "stadium-like" configurations made of MWCNT units whose formation and stability are a direct consequence of the self-assembly process occurring at the air/water interface. DFT calculations suggest the formation of molecular islands of oxygen-containing functional groups on the CNT surface. In addition, nudged elastic band studies reveal that, for these adsorbed phases, the reaction between two neighboring OH groups to produce atomic oxygen and a physisorbed water molecule is characterized by energy barriers of ∼0.2 eV. These small values could be at the origin of the sizable increase in chemisorbed single-oxygen species determined by XPS data after H2O2 treatment at 60 °C. The simulation of the C 1s binding energies (BE) allows us to more clearly identify the different oxygen-containing functionalities as well as to reveal how the local atomic environment affects their characteristic BEs. Even if we were unable to polyhydroxylate our carbon nanotubes, we believe that H2O2-treated MWCNTs are interesting materials for more complex post-functionalization procedures that might lead to the fabrication of novel carbon nanostructures.

Particle-in-cell Simulations of the Whistler Heat-flux Instability in Solar Wind Conditions.

In collision-poor plasmas from space, e.g., solar wind or stellar outflows, the heat flux carried by the strahl or beaming electrons is expected to be regulated by the self-generated instabilities. Recently, simultaneous field and particle observations have indeed revealed enhanced whistler-like fluctuations in the presence of counter-beaming populations of electrons, connecting these fluctuations to the whistler heat-flux instability (WHFI). This instability is predicted only for limited conditions of electron beam-plasmas, and has not yet been captured in numerical simulations. In this Letter we report the first simulations of WHFI in particle-in-cell setups, realistic for the solar wind conditions, and without temperature gradients or anisotropies to trigger the instability in the initiation phase. The velocity distributions have a complex reaction to the enhanced whistler fluctuations conditioning the instability saturation by a decrease of the relative drifts combined with induced (effective) temperature anisotropies (heating the core electrons and pitch-angle and energy scattering the strahl). These results are in good agreement with a recent quasilinear approach, and support therefore a largely accepted belief that WHFI saturates at moderate amplitudes. In the anti-sunward direction the strahl becomes skewed with a pitch-angle distribution decreasing in width as electron energy increases, which seems to be characteristic of self-generated whistlers and not to small-scale turbulence.

Low-dose-rate brachytherapy for prostate cancer in renal transplant recipients.

PURPOSE: Prostate cancer (PCa) is the most common malignancy among men and one of the most common neoplasms affecting renal transplant recipients (RTRs). The available treatments for localized PCa among the general population (GP), surgery and external beam radiotherapy, carry a risk of damage to the transplanted kidney, the ureters, and the bladder and therefore tend to be avoided by most groups. The objective of this study was to assess the efficacy and feasibility of low-dose-rate brachytherapy (LDR-BT) for PCa in RTRs. METHODS AND MATERIALS: We carried out a retrospective review on all RTRs diagnosed of PCa who had undergone LDR-BT at our institution between 2000 and 2015. Nine patients met these criteria, but 1 did not fulfill the followup. Hence, we analyzed 8 patients. We reviewed all clinical data for PCa and graft function in these patients and compared the results with the GP. RESULTS: Mean baseline prostate-specific antigen was 6.8 ± 1.9 ng/mL. All PCa had a Gleason score of 6 and were classified as low risk according the Europe Association of Urology guidelines. Mean followup after seed implantation was 48 ± 12.8 months. All 8 patients remain free of prostate-specific antigen failure. Five-year progression-free survival, cancer-specific survival, and overall survival rates were 100%, 100%, and 62.5%. There was no specific toxicity associated with LDR-BT, and there were no acute adverse events affecting the graft. CONCLUSIONS: LDR-BT is a feasible and acceptable treatment for localized PCa in RTRs. Oncological outcomes are similar to the GP, and there is minimal toxicity to the renal graft.

Learning curve for the management of tyrosine kinase inhibitors as the first line of treatment for patients with metastatic renal cancer. / Curva de aprendizaje en el manejo de los inhibidores de tirosina quinasa como primera línea de tratamiento en pacientes con cáncer renal metastásico.

OBJECTIVES: To analyse the learning curve for the management of tyrosine kinase inhibitors as the first line of treatment for patients with metastatic renal cancer. MATERIAL AND METHODS: We evaluated 32 consecutive patients treated in our department for metastatic renal cancer with tyrosine kinase inhibitors (pazopanib or sunitinib) as first-line treatment between September 2012 and November 2015. We retrospectively analysed this sample. We measured the time to the withdrawal of the first-line treatment, the time to progression and overall survival using Kaplan-Meier curves. The learning curve was analysed with the cumulative sum (CUSUM) methodology. RESULTS: In our series, the median time to the withdrawal of the first-line treatment was 11 months (95% CI 4.9-17.1). The mean time to progression was 30.4 months (95% CI 22.7-38.1), and the mean overall survival was 34.9 months (95% CI 27.8-42). By applying the CUSUM methodology, we obtained a graph for the CUSUM value of the time to withdrawal of the first-line treatment (CUSUM TW), observing 3 well-differentiated phases: phase 1 or initial learning phase (1-15), phase 2 (16-26) in which the management of the drug progressively improved and phase 3 (27-32) of maximum experience or mastery of the management of these drugs. The number of treated patients needed to achieve the proper management of these patients was estimated at 15. CONCLUSIONS: Despite the limitations of the sample size and follow-up time, we estimated (in 15 patients) the number needed to reach the necessary experience in the management of these patients with tyrosine kinase inhibitors. We observed no relationship between the time to the withdrawal of the first-line treatment for any cause and progression.

Raman spectra of single walled carbon nanotubes at high temperatures: pretreating samples in a nitrogen atmosphere improves their thermal stability in air.

We present a combined experimental and theoretical study dedicated to analyzing the structural stability and chemical reactivity of single walled carbon nanotubes (SWCNTs) in the presence of air and nitrogen atmospheres in the temperature interval of 300-1000 K. The temperature dependence of the radial breathing mode (RBM) region of the Raman spectra is irreversible in the presence of air, but it is reversible up to 1000 K in a nitrogen atmosphere. Our density functional theory (DFT) calculations reveal that irreversibility is due to partial degradation of SWCNTs produced by dissociative chemical adsorption of molecular oxygen on intrinsic defects of the nanotube surface. Oxygen partially opens the nanotubes forming semi-tubes with a non-uniform diameter distribution observed by Raman scattering. In contrast, heating CNTs in a nitrogen atmosphere seems to lead to the formation of nitrogen-doped SWCNTs. Our DFT calculations indicate that in general the most common types of nitrogen doping (e.g., pyridinic, pyrrolic, and substitutional) modify the location of the RBM frequency, leading also to frequency shifts and intensity changes of the surrounding modes. However, by performing a systematic comparison between calculated and measured spectra we have been able to infer the possible adsorbed configurations adopted by N species on the nanotube surface. Interestingly, by allowing previously nitrogen-exposed SWCNTs to interact with air at different temperatures (up to 1000 K) we note that the RBM region remains nearly unperturbed, defining thus our nitrogen-pretreated SWCNTs as more appropriate carbon nanostructures for high temperature applications in realistic environments. We believe that we have implemented a post-growth heat-treatment process that improves the stability of carbon nanotubes preserving their diameter and inducing a defect-healing process of the carbon wall.

Evaluation of the Spanish Urological Association quality care indicators in a kidney transplantation programme. / Evaluación de los indicadores de calidad asistencial de la Asociación Española de Urología en un programa de trasplante renal.

INTRODUCTION: Indicators show the presence of a phenomenon and its intensity. They assess the level of quality care and identify potential situations for improvement. Our objective is to assess the 2013 and 2014 quality care indicators of our department's kidney transplantation area. MATERIAL AND METHOD: For 2013 and 2014, we reviewed 88 and 106 kidney transplants and 47 and 66 extractions. We evaluated the quality care indicators developed by the Spanish Urological Association, analysing the results with the SPSS v 21.0 programme. RESULTS: The mean cold ischaemia time (CIT) was 14.96hours in 2013 and 18.07hours in 2014. The CIT was ≤18h in 53% and 56% of cadaveric donor kidneys in 2013 and 2014, respectively. The rate of relevant early onset urinary fistulae was 1.14% and 2.83% for each year. The rate of early transplantectomy due to a vascular complication was 3.41% and 2.83% for 2013 and 2014, respectively. Overall patient survival at 1 year was 100% for both periods, and graft survival at 1 year was 95% and 94.34% for 2013 and 2014, respectively. The rate of living-donor transplantation was 14.77% and 17.92%, and 92.31% and 68.42% of the living-donor extractions were laparoscopic for 2013 and 2014, respectively. Resident medical interns were the first surgeon in 6.67% and 12.64% of the transplantations and in 55.88% and 19.14% of the cadaveric extractions during 2013 and 2014, respectively. CONCLUSIONS: During the evaluated period, all quality care standards in kidney transplantation were met, except for CIT in both years and resident medical intern participation in kidney implantation in 2013. This analysis promotes improvements in quality care, highlighting weak spots that need work.

Conservative treatment of de novo renal carcinoma on kidney graft.

BACKGROUND: De novo renal carcinoma in kidney transplants is an uncommon but not exceptional condition and is of significant importance due to the potential for recipient mortality and graft loss. The aim of our study was to determine the management and outcome of these tumors in our Kidney Transplantation Unit. MATERIAL AND METHODS: We analyzed cases of de novo kidney tumors among patients who underwent transplantation in the last 17 years in our Kidney Transplantation Unit. We detected 3 cases of clear cell carcinoma and 1 case of papillary carcinoma on the graft. We conducted follow-up on the tumor and renal function and analyzed patient responses to changes in immunosuppression. RESULTS: Tumorectomy was performed in all cases, and subsequent transplantectomy was required for patients with papillary carcinoma. None of the patients had relevant surgical complications. We also changed the patients' regimen to a proliferation signal inhibitor or mTOR inhibitor and completely withdrew all anticalcineurin agents. With a mean follow-up of 43.5 months (15-61), the 3 patients with clear cell carcinoma survived with good graft function and with no evidence of tumor recurrence. The patient with papillary carcinoma underwent follow-up at another hospital center. CONCLUSIONS: Conservative surgery along with conversion to a proliferation signal inhibitor appears to be a safe option for treating primary tumors in kidney grafts and offers good oncological and renal function results in the short and medium term.

Adsorption of carbon monoxide on small aluminum oxide clusters: Role of the local atomic environment and charge state on the oxidation of the CO molecule.

We present extensive density functional theory (DFT) calculations dedicated to analyze the adsorption behavior of CO molecules on small AlxOy (±) clusters. Following the experimental results of Johnson et al. [J. Phys. Chem. A 112, 4732 (2008)], we consider structures having the bulk composition Al2O3, as well as smaller Al2O2 and Al2O units. Our electron affinity and total energy calculations are consistent with aluminum oxide clusters having two-dimensional rhombus-like structures. In addition, interconversion energy barriers between two- and one-dimensional atomic arrays are of the order of 1 eV, thus clearly defining the preferred isomers. Single CO adsorption on our charged AlxOy (±) clusters exhibits, in general, spontaneous oxygen transfer events leading to the production of CO2 in line with the experimental data. However, CO can also bind to both Al and O atoms of the clusters forming aluminum oxide complexes with a CO2 subunit. The vibrational spectra of AlxOy + CO2 provides well defined finger prints that may allow the identification of specific isomers. The AlxOy (+) clusters are more reactive than the anionic species and the final Al2O(+) + CO reaction can result in the production of atomic Al and carbon dioxide as observed from experiments. We underline the crucial role played by the local atomic environment, charge density distribution, and spin-multiplicity on the oxidation behavior of CO molecules. Finally, we analyze the importance of coadsorption and finite temperature effects by performing DFT Born-Oppenheimer molecular dynamics. Our calculations show that CO oxidation on AlxOy (+) clusters can be also promoted by the binding of additional CO species at 300 K, revealing the existence of fragmentation processes in line with the ones experimentally inferred.

Structure, electronic properties, and aggregation behavior of hydroxylated carbon nanotubes.

We present a combined experimental and theoretical study to analyze the structure, electronic properties, and aggregation behavior of hydroxylated multiwalled carbon nanotubes (OH-MWCNT). Our MWCNTs have average diameters of ~2 nm, lengths of approximately 100-300 nm, and a hydroxyl surface coverage θ~0.1. When deposited on the air/water interface the OH-MWCNTs are partially soluble and the floating units interact and link with each other forming extended foam-like carbon networks. Surface pressure-area isotherms of the nanotube films are performed using the Langmuir balance method at different equilibration times. The films are transferred into a mica substrate and atomic force microscopy images show that the foam like structure is preserved and reveals fine details of their microstructure. Density functional theory calculations performed on model hydroxylated carbon nanotubes show that low energy atomic configurations are found when the OH groups form molecular islands on the nanotube's surface. This patchy behavior for the OH species is expected to produce nanotubes having reduced wettabilities, in line with experimental observations. OH doping yields nanotubes having small HOMO-LUMO energy gaps and generates a nanotube → OH direction for the charge transfer leading to the existence of more hole carriers in the structures. Our synthesized OH-MWCNTs might have promising applications.

Ischaemic priapism as a presentation of chronic myeloid leukaemia.

OBJECTIVE: To describe ischemic priapism as an atypical presentation of chronic myeloid leukaemia. METHODS / RESULTS: We discuss two patients diagnosed with chronic myeloid leukaemia presenting an episode of priapism, adequately resolved after applying the treatment protocol established in our center. CONCLUSION: Priapism is defined as a persistent erection that persists despite not having sexual stimulus, without involvement of the spongy tissue of the penis. Its debut appearance as a hematologic dyscrasia is a rare event. It is a urological emergency, requiring early multidisciplinary (Urology and Hematology) management, since the speed in treatment will result in good functional results and the preservation of a good quality of life.

Oral human papillomavirus type-specific infection in HIV-infected men: a prospective cohort study among men who have sex with men and heterosexual men.

The natural history of type-specific oral infection of human papillomavirus (HPV) was assessed in a cohort of HIV-infected men (538 men who have sex with men (MSM); 195 heterosexuals). Risk factors associated with oral HPV infections were examined. The overall prevalence of HPV was 16%: HPV-16 was the most prevalent type (3.7% MSM; 7.8% heterosexuals). The prevalence of HPV-16 in heterosexuals was associated with CD4 nadir counts <200 cells/µL (ORadjusted = 3.0, 95% CI, 1.4-6.3). The overall incidence of HPV was similar between groups (11%), but the incidence of HPV-16 was higher in heterosexuals (ORadjusted = 3.2, 95% CI, 1.1-9.5). Not only MSM but also HIV-infected heterosexual men are at risk of HPV infection. Regular and careful oral inspection is needed.