Retrospective survival analysis of the use of uncemented modular tapered stems for revision in periprosthetic Vancouver B-type fractures. Is instability a threat to survival?

INTRODUCTION AND OBJECTIVES: Periprosthetic hip fractures show increasing incidence and complexity, representing a challenge for the surgeon. We aimed to evaluate the survival of uncemented modular tapered stems in the treatment of periprosthetic Vancouver B2 and B3 type fractures and review the main complications and factors associated with decreased survival. MATERIALS AND METHODS: We performed a retrospective study of patients submitted to revision arthroplasty for treatment of periprosthetic femoral stem Vancouver B2 and B3 type fractures with an uncemented modular fluted tapered stem (MRP-Titan). Demographic and radiographic parameters were analyzed. The survival rate (free of reoperation) was calculated at 2- and 5-years using the Kaplan-Meier survivorship analysis. RESULTS: Thirty-nine patients were included with a mean age of 73.5 years and a mean follow-up of 5 years. Arthroplasty survivorship at 2 years was 73.7% and at 5 years was 67.5% (mean 8.4 years; range 6.7-10.2). Survivorship was inferior in the patients with episodes of instability (mean 2.5 years; range 0-5.42) (p<0.001). At least one episode of instability occurred in 26.3% of patients and 60% of these patients had a femoral head size 32mm or lower. At least one episode of instability occurred in 71.4% of patients with a greater trochanter fracture (p=0.008). The consolidation rate was 90.6% and the mortality rate was 23.7%. In the group of patients that died, 55.6% were submitted to at least one revision surgery (p=0.044). CONCLUSION: Survivorship of an uncemented modular stem (MRP-Titan) in revision for PHF is significantly reduced by episodes of instability.

Electron stimulated desorption from condensed benzene.

The electron induced dissociation of condensed benzene (C6H6) in thin films deposited on a Pt substrate is investigated by electron stimulated desorption (ESD) of anions and cations. The desorbed yields are recorded as a function of incident electron energy in the range of 10 to 950 eV for a fixed film thickness of 2 monolayers (ML) and for a fixed energy of 950 eV, as well as a function of film thickness from 0.5 to 8 monolayers (ML) for anions, and from 0.5 to 12ML for cations. Both energy and thickness dependencies are discussed in terms of the three main mechanisms yielding positively and/or negatively charged fragments: dissociative electron attachment (DEA), dipolar dissociation (DD) and dissociative ionization (DI) processes. At the probed energies, DD is the major mechanism, while DEA is predominantly induced by secondary electrons from the Pt substrate. Desorption of the parent positive ion is strongly suppressed. Similar qualitative behaviours are observed for the energy dependence of both anion and cation ESD yields, while some discrepancies exist in the thickness dependence, including a very significant systematic magnitude difference found between such ions formation. An estimation of the effective DD cross-section including the desorption probability is obtained. Feasible mechanisms behind the observed energy and thickness dependences for anion and cation yields are proposed. These results highlight the need for further investigations to better understand the underlying processes of electron induced dissociation in condensed matter.

Bursaphelenchus mucronatus (Nematoda: Parasitaphelenchidae) associated with Monochamus galloprovincialis from Bosnia and Herzegovina and Georgia.

Bursaphelenchus mucronatus was detected in association with the pine sawyer beetle (Monochamus galloprovincialis) during the implementation and testing of cross traps with insect attractants as an efficient tool for detection survey for pine wood nematode (Bursaphelenchus xylophilus) in Bosnia and Herzegovina and Georgia in 2017 and 2018, respectively. This nematode was characterized by morphological, morphometric and molecular features. This is the first report of B. mucronatus in association with a M. galloprovincialis in Bosnia and Herzegovina and in Georgia.

Evaluated electron scattering cross section dataset for gaseous benzene in the energy range 0.1-1000 eV.

In this study, a complete and self-consistent cross section dataset for electron transport simulations through gaseous benzene in the energy range 0.1-1000 eV has been critically compiled. Its reliability has been evaluated through a joint experimental and computational procedure. To accomplish this, the compiled dataset has been used as input for event-by-event Monte Carlo simulations of the magnetically confined electron transport through gaseous benzene, and the simulated transmitted intensity has been compared with the experimental one for different incident energies and benzene gas pressures.

Cefaleas primarias con inicio en la infancia y la adolescencia: historia natural y factores pronósticos en una población portuguesa / Primary headache with onset in childhood and adolescence: natural history and prognostic factors in a Portuguese population

Introducción: Las cefaleas son el trastorno neurológico más habitual en la población pediátrica e influyen notablemente en su calidad de vida. La finalidad de este estudio es caracterizar una cohorte de pacientes en seguimiento en una unidad de neurología pediátrica entre el 1 de enero de 2013 y el 31 de diciembre de 2021. Materiales y métodos: Hemos revisado informes médicos y seleccionado a pacientes con cefaleas primarias y un seguimiento mínimo de 12 meses.Resultados: Se incluyó a un total de 226 pacientes, el 54,4% mujeres, con una media de edad al comenzar las cefaleas de 9 ± 3,5 (3,1-16,5) años; el 63,5% eran prepuberales. Se identificó un historial familiar positivo de cefalea en el 76,6% de los casos y factores desencadenantes en el 63,6%. En una primera evaluación clínica, el 45,1% se identificó como migrañas sin aura; el 10,6%, como migrañas con aura; el 3,5%, como cefalea tensional; el 8%, como de tipo mixto (cefalea tensional y migraña); el 1,3%, de otro tipo; y el 31,4% resultó inclasificable. Los pacientes se sometieron a un seguimiento promedio de 2,4 (1,8-3,3) años. El diagnóstico de cefalea tensional se mantuvo estable en el 75% de los pacientes y se solucionó en un 25%; para el 13% de los pacientes con migraña sin aura, el diagnóstico cambió a otro tipo de cefalea, y para el 17,4%, se solucionó; para el 44,4% de los pacientes sin migraña con aura, el diagnóstico cambió por el de otro tipo de cefalea, y para el 11,1%, se resolvió. De las variables estudiadas, sólo la duración del episodio de cefalea tuvo una asociación significativa con la remisión de la cefalea, con una odds ratio de 0,16 (p = 0,03; intervalo de confianza al 95%: 0,032-0,84).Conclusiones: Nuestro estudio muestra que el tipo de cefalea en la población pediátrica cambia con el paso del tiempo, especialmente en los pacientes con migraña con aura. La duración de cada uno de los episodios de cefalea se presentó como un predictor de la remisión de la cefalea con el paso del...(AU)

Introduction: Headaches are the most frequent neurological disorder in the pediatric population, with great impact on quality of life. This study aims to characterize a cohort of patients followed at a pediatric neurology unit between January 1st 2013 and December 31st, 2021. Materials and methods: We reviewed medical records and selected patients with primary headaches and a minimum follow-up of 12 months. Results: A total of 226 patients were included, 54.4% female, with an average age at headache onset of 9 ± 3.5 (3.1-16.5) years; 63.5% were prepubertal. A positive family history of headache was identified in 76.6% of cases and triggers in 63.6%. At first clinical assessment, 45.1% were classified as migraine without aura, 10.6% as migraine with aura, 3.5% tension-type, 8% mixed (tension and migraine), 1.3% other type and 31.4% were unclassifiable. The patients had a median follow-up of 2.4 (1.8-3.3) years. The diagnosis of tension-type headaches remained stable in 75% of the patients and resolved in 25%; 13% of the patients with migraine without aura changed into another type of headache and 17.4% resolved; 44.4% of the patients with migraine with aura turned into another type of headache and 11.1% resolved. Of the variables studied, only duration of headache episode had a significant association with headache remission, with odds ratio 0.16 (p = 0.03; 95% confidence interval: 0.032-0.84).Conclusions: Our study shows that headache type in pediatric population changes over time, especially in those with migraine with aura. The duration of each headache episode was presented as a predictor of headache remission over time.(AU)

Primary headache with onset in childhood and adolescence: natural history and prognostic factors in a Portuguese population. / Cefaleas primarias con inicio en la infancia y la adolescencia: historia natural y factores pronósticos en una población portuguesa.

INTRODUCTION: Headaches are the most frequent neurological disorder in the pediatric population, with great impact on quality of life. This study aims to characterize a cohort of patients followed at a pediatric neurology unit between January 1st 2013 and December 31st, 2021. MATERIALS AND METHODS: We reviewed medical records and selected patients with primary headaches and a minimum follow-up of 12 months. RESULTS: A total of 226 patients were included, 54.4% female, with an average age at headache onset of 9 ± 3.5 (3.1-16.5) years; 63.5% were prepubertal. A positive family history of headache was identified in 76.6% of cases and triggers in 63.6%. At first clinical assessment, 45.1% were classified as migraine without aura, 10.6% as migraine with aura, 3.5% tension-type, 8% mixed (tension and migraine), 1.3% other type and 31.4% were unclassifiable. The patients had a median follow-up of 2.4 (1.8-3.3) years. The diagnosis of tension-type headaches remained stable in 75% of the patients and resolved in 25%; 13% of the patients with migraine without aura changed into another type of headache and 17.4% resolved; 44.4% of the patients with migraine with aura turned into another type of headache and 11.1% resolved. Of the variables studied, only duration of headache episode had a significant association with headache remission, with odds ratio 0.16 (p = 0.03; 95% confidence interval: 0.032-0.84). CONCLUSIONS: Our study shows that headache type in pediatric population changes over time, especially in those with migraine with aura. The duration of each headache episode was presented as a predictor of headache remission over time.

TITLE: Cefaleas primarias con inicio en la infancia y la adolescencia: historia natural y factores pronósticos en una población portuguesa.Introducción. Las cefaleas son el trastorno neurológico más habitual en la población pediátrica e influyen notablemente en su calidad de vida. La finalidad de este estudio es caracterizar una cohorte de pacientes en seguimiento en una unidad de neurología pediátrica entre el 1 de enero de 2013 y el 31 de diciembre de 2021. Materiales y métodos. Hemos revisado informes médicos y seleccionado a pacientes con dolores de cabeza primarios y un seguimiento mínimo de 12 meses. Resultados. Se incluyó a un total de 226 pacientes, el 54,4% mujeres, con una media de edad al comenzar las cefaleas de 9 ± 3,5 (3,1-16,5) años; el 63,5% eran prepuberales. Se identificó un historial familiar positivo de cefalea en el 76,6% de los casos y factores desencadenantes en el 63,6%. En una primera evaluación clínica, el 45,1% se identificó como migrañas sin aura; el 10,6%, como migrañas con aura; el 3,5%, como cefalea tensional; el 8%, como de tipo mixto (cefalea tensional y migraña); el 1,3%, de otro tipo; y el 31,4% resultó inclasificable. Los pacientes se sometieron a un seguimiento promedio de 2,4 (1,8-3,3) años. El diagnóstico de cefalea tensional se mantuvo estable en el 75% de los pacientes y se solucionó en un 25%; para el 13% de los pacientes con migraña sin aura, el diagnóstico cambió a otro tipo de cefalea, y para el 17,4%, se solucionó; para el 44,4% de los pacientes sin migraña con aura, el diagnóstico cambió por el de otro tipo de cefalea, y para el 11,1%, se resolvió. De las variables estudiadas, sólo la duración del episodio de cefalea tuvo una asociación significativa con la remisión de la cefalea, con una odds ratio de 0,16 (p = 0,03; intervalo de confianza al 95%: 0,032-0,84). Conclusiones. Nuestro estudio muestra que el tipo de cefalea en la población pediátrica cambia con el paso del tiempo, especialmente en los pacientes con migraña con aura. La duración de cada uno de los episodios de cefalea se presentó como un predictor de la remisión de la cefalea con el paso del tiempo.

Electronically excited states of formic acid investigated by theoretical and experimental methods.

Absolute cross-section values are reported from high-resolution vacuum ultraviolet (VUV) photoabsorption measurements of gas-phase formic acid (HCOOH) in the photon energy range 4.7-10.8 eV (265-115 nm), together with quantum chemical calculations to provide vertical energies and oscillator strengths. The combination of experimental and theoretical methods has allowed a comprehensive assignment of the electronic transitions. The VUV spectrum reveals various vibronic features not previously reported in the literature, notably associated with (3pa'←10a'), (3p'a'←10a'), (3sa'←2a″) and (3pa'←2a″) Rydberg transitions. The assignment of vibrational features in the absorption bands reveal that the C=O stretching, v3'a', the H'-O-C' deformation, v5'a', the C-O stretching, v6'a', and the O=C-O' deformation, v7'a' modes are mainly active. The measured absolute photoabsorption cross sections have also been used to estimate the photolysis lifetime of HCOOH in the upper stratosphere (30-50 km), showing that solar photolysis is an important sink at altitudes above 30 km but not in the troposphere. Potential energy curves for the lowest-lying electronic excited states, as a function of the C=O coordinate, are obtained employing time dependent density functional theory (TD-DFT). These calculations have shown the relevance of internal conversion from Rydberg to valence character governing the nuclear dynamics, yielding clear evidence of the rather complex multidimensional nature of the potential energy surfaces involved.

Hexachlorobenzene-negative ion formation in electron attachment experiments.

In this contribution, we report a comprehensive study on the formation of hexachlorobenzene (C6Cl6) negative ions probed by low-energy electron interactions from 0 up to 12 eV in a gas-phase crossed beam experiment. The anionic yields as a function of the electron energy reveal a rich fragmentation pattern of the dissociative electron attachment process, yet the most intense ion has been assigned to the non-dissociated parent anion that survives long enough within the detection time window. Other less intense fragment anions have been assigned as Cl-, Cl2-, C6Cl4-, and C6Cl5-. The experimental results are accompanied by quantum chemical calculations at various levels of accuracy, providing an insight into the electronic structure, thermochemical thresholds, electron affinities and structures of neutral and anionic molecular species. The electron attachment process induces a considerable geometry change in the temporary-negative ion relative to the neutral molecule, where the most intense fragment anion assigned to Cl- can be formed solely through a curve crossing involving a π*/σ* coupling. The yield of chlorine anions shows a signature of vibrational excitation reminiscent of a Jahn-Teller distortion.

Should oral chlorhexidine remain in ventilator-associated pneumonia prevention bundles?

Ventilator-associated pneumonia (VAP) is related with high mortality, duration of mechanical ventilation and costs. Recent studies have questioned the safety and effectiveness of oral chlorhexidine to prevent VAP. We sought to verify whether the adverse effects of this substance outweigh its benefits. We searched several databases and selected studies that investigated the use of oral chlorhexidine and its impact on mortality. No association between oral chlorhexidine and lower VAP rates was found on meta-analyses of double-blind randomized trials, however significant increase in mortality was reported. It is speculated that chlorhexidine can cause damage to several organic sectors and cytotoxicity. Although it still can be beneficial in specific settings, robust evidence to recommend its routine application for all mechanically ventilated patients is lacking; therefore, given the possibility of harm, it would be better to follow the principle of non-maleficence until more studies becomes available.

Should oral chlorhexidine remain in ventilator-associated pneumonia prevention bundles? / ¿Debe permanecer la clorhexidina oral en los paquetes de prevención de la neumonía asociada al respirador?

Ventilator-associated pneumonia (VAP) is related with high mortality, duration of mechanical ventilation and costs. Recent studies have questioned the safety and effectiveness of oral chlorhexidine to prevent VAP. We sought to verify whether the adverse effects of this substance outweigh its benefits. We searched several databases and selected studies that investigated the use of oral chlorhexidine and its impact on mortality. No association between oral chlorhexidine and lower VAP rates was found on meta-analyses of double-blind randomized trials, however significant increase in mortality was reported. It is speculated that chlorhexidine can cause damage to several organic sectors and cytotoxicity. Although it still can be beneficial in specific settings, robust evidence to recommend its routine application for all mechanically ventilated patients is lacking; therefore, given the possibility of harm, it would be better to follow the principle of non-maleficence until more studies becomes available (AU)

La neumonía asociada al respirador (VAP) está relacionada con una elevada mortalidad, mayor duración de la ventilación mecánica y costes elevados. Estudios recientes han cuestionado la seguridad y la eficacia de la clorhexidina oral para prevenir la VAP. Hemos intentado verificar si los efectos adversos de esta sustancia superan sus beneficios. Se realizaron búsquedas en diversas bases de datos y se seleccionaron estudios que habían investigado el uso de la clorhexidina oral y su impacto sobre la mortalidad. En los metaanálisis de los ensayos aleatorizados a doble ciego no se encontró ninguna asociación entre clorhexidina oral y tasas de VAP más bajas; sin embargo, sí se informó de un aumento significativo de la mortalidad. Se especula que la clorhexidina puede causar daño a varias partes del organismo y citotoxicidad. Pese a que todavía podría ser beneficiosa en entornos específicos, no se dispone de evidencias sólidas para recomendar su aplicación rutinaria para todos los pacientes sometidos a ventilación mecánica; por lo tanto, dada la posibilidad de ocasionar daños, sería mejor seguir el principio de no maleficencia hasta que se disponga de más estudios (AU)

Anionic states of C6Cl6 probed in electron transfer experiments.

This is the first comprehensive investigation on the anionic species formed during collisions of fast neutral potassium (K) atoms with neutral hexachlorobenzene (C6Cl6) molecules in the laboratory frame range from 10 up to 100 eV. In such ion-pair formation experiments we also report a novel K+ energy loss spectrum obtained in the forward scattering giving evidence of the most accessible electronic states. The vertical electron affinity of (-3.76 ± 0.20) eV has been obtained and assigned to a purely repulsive transition from the C6Cl6 ground state to a state of the temporary negative ion yielding Cl- formation. These experimental findings are also supported by state-of-the art theoretical calculations on the electronic structure of C6Cl6 in the presence of a potassium atom and are used for analysing the lowest unoccupied molecular orbitals participating in the collision process. From the time-of-flight mass spectra recorded in the wide collision energy range, more than 80% of the total anion yield is due to the undissociated parent anion C6Cl6-, C6Cl5- and Cl- formation. Other fragment anions such as C6Cl4-, C3Cl2-, C2Cl- and Cl2- that undergo complex internal reactions with the temporary negative ion formed after electron transfer account for less than 20% of the total yield. The joint experimental and theoretical methodologies employed in these electron transfer studies provide the most comprehensive and unique assignments of the hexachlorobenzene anionic species and the role of C6Cl6 electronic states in collision induced dissociation to date.

A tailored approach to abdominoperineal resection for rectal cancer: multicentre analysis of short-term outcomes and impact on oncological survival.

PURPOSE: Abdominoperineal resection of the rectum has evolved over the last century, with few modifications until 2007, when extralevator abdominoperineal resection was introduced, which improved local disease control but resulted in a significant rise in perineal complications. We adopted a modified approach in which dissection was tailored according to magnetic resonance-defined tumour involvement. The aim of this study was to assess short-term and long-term oncological outcomes following a tailored abdominoperineal resection (APR) approach. METHODS: This study was a retrospective review of prospectively maintained databases at three centres: Portsmouth NHS Trust (UK), Poole General Hospital (UK) and Champalimaud's Cancer Foundation, Portugal. The study included consecutive patients who underwent abdominoperineal resection from October 2008 until April 2018 under the supervision of the senior author. Oncological outcomes, including overall survival and disease-free survival, were used as the main outcome measures. RESULTS: A total of 584 patients underwent rectal cancer surgery during the study period. The APR ratio was 65/584 (11%). The median age was 66 years. Neoadjuvant treatment was administered to 74% of patients. Of the patients, 91% underwent surgery via a minimally invasive approach. The median hospital stay was 7 days. Patients were followed up for a median of 41 months. Only four patients had positive resection margins. The 5-year overall and disease-free survival rates were 64% and 62%, respectively. CONCLUSION: Our data suggest that tailored APR has similar short-term and long-term oncological outcomes compared with extralevator abdominoperineal resection but reduced perineal wound complications. We believe this approach could be a safe alternative but recommend a larger sample size to accurately assess its effectiveness.

Formation of negative and positive ions in the radiosensitizer nimorazole upon low-energy electron collisions.

A comprehensive investigation of low-energy electron attachment and electron ionization of the nimorazole radiosensitizer used in cancer radiation therapy is reported by means of a gas-phase crossed beam experiment in an electron energy range from 0 eV to 70 eV. Regarding negative ion formation, we discuss the formation of fifteen fragment anions in the electron energy range of 0 eV-10 eV, where the most intense signal is assigned to the nitrogen dioxide anion NO2 -. The other fragment anions have been assigned to form predominantly from a common temporary negative ion state close to 3 eV of the nitroimidazole moiety, while the morpholine moiety seems to act only as a spectator in the dissociative electron attachment event to nimorazole. Quantum chemical calculations have been performed to help interpreting the experimental data with thermochemical thresholds, electron affinities, and geometries of some of the neutral molecules. As far as positive ion formation is concerned, the mass spectrum at the electron energy of 70 eV shows a weakly abundant parent ion and C5H10NO+ as the most abundant fragment cation. We report appearance energy (AE) measurements for six cations. For the intact nimorazole molecular cation, the AE of 8.16 ± 0.05 eV was obtained, which is near the presently calculated adiabatic ionization energy.

Hypoxia enhances ILC3 responses through HIF-1α-dependent mechanism.

Group 3 innate lymphoid cells (ILC3) have a prominent role in the maintenance of intestine mucosa homeostasis. The hypoxia-inducible factor (HIF) is an important modulator of immune cell activation and a key mechanism for cellular adaptation to oxygen deprivation. However, its role on ILC3 is not well known. In this study, we investigated how a hypoxic environment modulates ILC3 response and the subsequent participation of HIF-1 signaling in this process. We found increased proliferation and activation of intestinal ILC3 at low oxygen levels, a response that was phenocopied when HIF-1α was chemically stabilized and was reversed when HIF-1 was blocked. The increased activation of ILC3 relied on a HIF-1α-dependent transcriptional program, but not on mTOR-signaling or a switch to glycolysis. HIF-1α deficiency in RORyt compartment resulted in impaired IL-17 and IL-22 production by ILC3 in vivo, which reflected in a lower expression of their target genes in the intestinal epithelium and an increased susceptibility to Clostridiodes difficile infection. Taken together, our results show that HIF-1α activation in intestinal ILC3 is relevant for their functions in steady state and infectious conditions.

Thermal desorption effects on fragment ion production from multi-photon ionized uridine and selected analogues.

Experiments on neutral gas-phase nucleosides are often complicated by thermal lability. Previous mass spectrometry studies of nucleosides have identified enhanced relative production of nucleobase ions (e.g. uracil+ from uridine) as a function of desorption temperature to be the critical indicator of thermal decomposition. On this basis, the present multi-photon ionization (MPI) experiments demonstrate that laser-based thermal desorption is effective for producing uridine, 5-methyluridine, and 2'-deoxyuridine targets without thermal decomposition. Our experiments also revealed one notable thermal dependence: the relative production of the sugar ion C5H9O4 + from intact uridine increased substantially with the desorption laser power and this only occurred at MPI wavelengths below 250 nm (full range studied 222-265 nm). We argue that this effect can only be rationalized plausibly in terms of changing populations of different isomers, tautomers, or conformers in the target as a function of the thermal desorption conditions. Furthermore, the wavelength threshold behavior of this thermally-sensitive MPI channel indicates a critical dependence on neutral excited state dynamics between the absorption of the first and second photons. The experimental results are complemented by density functional theory (DFT) optimizations of the lowest-energy structure of uridine and two further conformers distinguished by different orientations of the hydroxymethyl group on the sugar part of the molecule. The energies of the transitions states between these three conformers are low compared with the energy required for decomposition.

Should oral chlorhexidine remain in ventilator-associated pneumonia prevention bundles?

Ventilator-associated pneumonia (VAP) is related with high mortality, duration of mechanical ventilation and costs. Recent studies have questioned the safety and effectiveness of oral chlorhexidine to prevent VAP. We sought to verify whether the adverse effects of this substance outweigh its benefits. We searched several databases and selected studies that investigated the use of oral chlorhexidine and its impact on mortality. No association between oral chlorhexidine and lower VAP rates was found on meta-analyses of double-blind randomized trials, however significant increase in mortality was reported. It is speculated that chlorhexidine can cause damage to several organic sectors and cytotoxicity. Although it still can be beneficial in specific settings, robust evidence to recommend its routine application for all mechanically ventilated patients is lacking; therefore, given the possibility of harm, it would be better to follow the principle of non-maleficence until more studies becomes available.