RESUMEN
Nurses are an integral part of the multidisciplinary team caring for a patient eligible for endovascular thrombectomy. Their care includes obtaining health history, performing clinical assessments, using critical thinking to anticipate the care path, and communicating findings to other team members. The prehospital and emergency department nurses utilize stroke severity scales to identify a possible thrombectomy candidate and help expedite intervention. In the interventional laboratory, nursing collaborates with radiology technologists and interventionalists to ensure patient safety and monitor for intraprocedural complications. Post-procedure, the intensive care nurse delivers complex care to ensure optimal neurological outcome and assess for postprocedural complications. Nursing is essential in every phase of care along with collaboration with other disciplines.
Asunto(s)
Isquemia Encefálica , Procedimientos Endovasculares , Accidente Cerebrovascular Isquémico , Accidente Cerebrovascular , Isquemia Encefálica/complicaciones , Isquemia Encefálica/cirugía , Procedimientos Endovasculares/métodos , Humanos , Accidente Cerebrovascular/etiología , Accidente Cerebrovascular/cirugía , Trombectomía/métodos , Resultado del TratamientoRESUMEN
INTRODUCTION: The pharmacokinetics (PK), efficacy and safety of moroctocog alfa (AF-CC) have been demonstrated in haemophilia A patients aged ≥6 years. AIM: These studies aimed to further describe moroctocog alfa (AF-CC) experience in paediatric patients (<12 years) with severe haemophilia A (FVIII:C < 1%). METHODS: Two prospective, open-label studies enrolled patients aged <12 years: one study with 37 previously treated patients (PTPs) and another with 23 previously untreated patients (PUPs). All patients initially received 50 IU/kg of moroctocog alfa (AF-CC) to evaluate either recovery alone, or with other PK parameters (6 to <12 years) before continuing treatment for 100 exposure days (EDs) or 24 months. RESULTS: At baseline, mean (±SD) recovery ranged between 1.32 ± 0.65 (PUPs aged <2 years) and 2.13 ± 0.82 (PTPs aged 6 to <12 years). The mean (±SD) half-life was 9.12 ± 1.94 hours in PTPs aged 6 to <12 years. No new safety signals were detected in either study, 2 transient lower titre inhibitors occurred in PTPs while 8 inhibitors (3 low and 5 high titre) were detected in PUPs. Most bleeding episodes resolved with one infusion (94% [893/954]). The annualised bleeding rate (ABR) in the PTP study was 27.5 and 4.2 for patients reporting an on-demand and routine prophylaxis regimen at baseline, respectively. In the PUP study, the overall ABR was 5.9. CONCLUSION: Moroctocog alfa (AF-CC) had expected PK findings (lower recovery in young children compared with older children) along with being safe and efficacious in a population of young severe haemophilia A patients.
Asunto(s)
Factor VIII/uso terapéutico , Hemofilia A/tratamiento farmacológico , Niño , Preescolar , Factor VIII/efectos adversos , Factor VIII/inmunología , Femenino , Hemofilia A/inmunología , Humanos , Lactante , Recién Nacido , Masculino , Estudios Prospectivos , SeguridadRESUMEN
Reef-building corals maintain a symbiotic relationship with dinoflagellate algae of the genus Symbiodinium, and this symbiosis is vital for the survival of the coral holobiont. Symbiodinium community composition within the coral host has been shown to influence a coral's ability to resist and recover from stress. A multitude of stressors including ocean warming, ocean acidification, and eutrophication have been linked to global scale decline in coral health and cover in recent decades. Three distinct thermal regimes (highTP, modTP, and lowTP) following an inshore-offshore gradient of declining average temperatures and thermal variation were identified on the Belize Mesoamerican Barrier Reef System (MBRS). Quantitative metabarcoding of the ITS-2 locus was employed to investigate differences and similarities in Symbiodinium genetic diversity of the Caribbean corals Siderastrea siderea, S. radians, and Pseudodiploria strigosa between the three thermal regimes. A total of ten Symbiodinium lineages were identified across the three coral host species. S. siderea was associated with distinct Symbiodinium communities; however, Symbiodinium communities of its congener, S. radians and P. strigosa, were more similar to one another. Thermal regime played a role in defining Symbiodinium communities in S. siderea but not S. radians or P. strigosa. Against expectations, Symbiodinium trenchii, a symbiont known to confer thermal tolerance, was dominant only in S. siderea at one sampled offshore site and was rare inshore, suggesting that coral thermal tolerance in more thermally variable inshore habitats is achieved through alternative mechanisms. Overall, thermal parameters alone were likely not the only primary drivers of Symbiodinium community composition, suggesting that environmental variables unrelated to temperature (i.e., light availability or nutrients) may play key roles in structuring coral-algal communities in Belize and that the relative importance of these environmental variables may vary by coral host species.
Asunto(s)
Antozoos/parasitología , Dinoflagelados/clasificación , Dinoflagelados/fisiología , Especificidad del Huésped , Animales , Antozoos/genética , Belice , ADN/análisis , Dinoflagelados/genética , Monitoreo del Ambiente , Variación Genética , Calor , Océanos y Mares , Filogenia , Simbiosis/fisiología , Temperatura , TermotoleranciaRESUMEN
The authors regret that acknowledgment for Dr. Adrian Marchetti was omitted from the manuscript. The correct acknowledgment is written below.
RESUMEN
PURPOSE: Within an overarching evaluation framework, this study explored the experiences of course participants and administrators of an intercountry master's degree in nursing between South Africa and Mozambique. The lessons learnt were used to inform nursing and health policy for the Mozambican health system. METHODS: Kirkpatrick's four levels of training evaluation and a results-oriented approach to capacity change were integrated to form a hybrid evaluation framework to capture information about course implementation and the context/environment within which it was delivered. The study used quantitative and qualitative methods including a self-administered survey of course participants, document review, in-depth, semi-structured interviews with course administrators and two focus group discussions with course participants. FINDINGS: Participants enrolled in the course primarily to gain new knowledge and to improve health outcomes; course participants and administrators responded positively to the course design, course implementation and the quality of teaching. Knowledge and skills gained help to build graduates' confidence and boost their attitude towards nursing. Paradoxically, graduates felt powerless to transfer knowledge and effect change in practice. CONCLUSION: This collaborative, capacity development project produced postgraduate nurses in two areas of specialization, namely, critical care and trauma nursing and maternal and neonatal health. While course participants gained significant benefits in new skills and knowledge and a higher degree qualification, the rewards available to them in the public health system remain unclear. IMPLICATIONS FOR NURSING AND HEALTH POLICY: Lessons learnt may serve to influence policy decisions about the role of the Ministry of Health and other stakeholders in sustaining the output and quality of postgraduate nurses for the Mozambican health system. A strategic approach informed by multilevel policies at government, organizational and managerial levels should be adopted to systematically minimize and remove barriers to the transfer and utilization of knowledge and skills in the workplace.
Asunto(s)
Atención a la Salud/organización & administración , Educación de Postgrado en Enfermería/organización & administración , Política de Salud , Cooperación Internacional , Personal de Enfermería/educación , Adulto , Femenino , Grupos Focales , Humanos , Masculino , Persona de Mediana Edad , Mozambique , Sudáfrica , Adulto JovenRESUMEN
Grazing incidence and grazing emission X-ray fluorescence spectroscopy (GI/GE-XRF) are techniques that enable nondestructive, quantitative analysis of elemental depth profiles with a resolution in the nanometer regime. A laboratory setup for soft X-ray GEXRF measurements is presented. Reasonable measurement times could be achieved by combining a highly brilliant laser produced plasma (LPP) source with a scanning-free GEXRF setup, providing a large solid angle of detection. The detector, a pnCCD, was operated in a single photon counting mode in order to utilize its energy dispersive properties. GEXRF profiles of the Ni-Lα,ß line of a nickel-carbon multilayer sample, which displays a lateral (bi)layer thickness gradient, were recorded at several positions. Simulations of theoretical profiles predicted a prominent intensity minimum at grazing emission angles between 5° and 12°, depending strongly on the bilayer thickness of the sample. This information was used to retrieve the bilayer thickness gradient. The results are in good agreement with values obtained by X-ray reflectometry, conventional X-ray fluorescence and transmission electron microscopy measurements and serve as proof-of-principle for the realized GEXRF setup. The presented work demonstrates the potential of nanometer resolved elemental depth profiling in the soft X-ray range with a laboratory source, opening, for example, the possibility of in-line or even in situ process control in semiconductor industry.
RESUMEN
In cystic fibrosis (CF) mucociliary clearance of the entire respiratory system is impaired. This allows pathogens, such as Pseudomonas aeruginosa to persist and proliferate, which by progressive pulmonary destruction causes 90 % of premature deaths due to this inherited disease. The dramatic improvement in life expectation of patients due to intensive therapy has resulted in the inevitable but variably expressed sinonasal involvement coming into the clinical and scientific focus. Thereby, almost all CF patients reveal sinonasal pathology and many suffer from chronic rhinosinusitis. Recently, the sinonasal niche has been recognized as a site of initial and persistent colonization by pathogens. This article presents the pathophysiological background of this multiorgan disease as well as general diagnostic and therapeutic standards. The focus of this article is on sinonasal involvement and conservative and surgical options for treatment. Prevention of pathogen acquisition is an essential issue in the otorhinolaryngological treatment of CF patients.
Asunto(s)
Fibrosis Quística/diagnóstico , Fibrosis Quística/terapia , Rinitis/diagnóstico , Rinitis/terapia , Sinusitis/diagnóstico , Sinusitis/terapia , Fibrosis Quística/complicaciones , Humanos , Rinitis/etiología , Sinusitis/etiologíaRESUMEN
INTRODUCTION: The rights, roles and responsibilities of servicewomen in the UK Armed Forces has changed dramatically over time. Previously, service personnel were automatically discharged from the military if they became pregnant. As the percentage of servicewomen in the UK Armed Forces increases, having children during service is becoming more common and maternity policies are now in place. Having children during military service can impact on the health and well-being of servicewomen, including a greater risk of illness when returning to work. METHODS: A cross-sectional, self-report survey was used for data collection. The response rate was approximately 45%. Female Army veterans were recruited via a female military association. The survey collected data on parental status, the timing of their first child (during or after service), and several current mental and physical health and well-being outcomes. RESULTS: Of the 750 female Army veterans who completed the survey, 406 reported having children. Of those with children, 14.5% had their first child during service compared with 85.5% after service. The most frequently endorsed health outcomes were low social support, loneliness and common mental health difficulties. Participants who had their first child during military service were more likely to have left the service non-voluntarily. CONCLUSIONS: This study provided insight into the impacts of having a first child during military service on servicewomen. Overall, female Army veterans who had their first child during service had poorer outcomes, including leaving service non-voluntarily. However, none of the health or well-being outcomes remained significant after adjusting the results. This study explored a widely under researched population and field of research. Future research should seek to expand on our findings and continue to explore the impacts of having a first child during military service for military mothers.
Asunto(s)
Familia Militar , Personal Militar , Embarazo , Humanos , Femenino , Niño , Madres , Estudios Transversales , Encuestas y CuestionariosRESUMEN
INTRODUCTION: At the start of the COVID-19 pandemic, individuals with pre-existing mental health difficulties were thought to be vulnerable to mental health deterioration due to the emerging threat and the actions taken to control infection rates. Yet, there remained a paucity of research investigating changes in veteran well-being, a population facing higher rates of mental health difficulties compared with the general public. This longitudinal study aimed to investigate the mental health and well-being of UK veterans with pre-existing mental health difficulties at two time points during the COVID-19 pandemic. METHODS: UK treatment-seeking veterans (N=121) completed an online survey administered towards the end of the first UK lockdown in June 2020 and 1 year later. Data were gathered on sociodemographic characteristics as well as psychometric measures of post-traumatic stress disorder (PTSD), common mental disorders (CMDs), anger difficulties and alcohol misuse. RESULTS: The proportion of veterans meeting criteria of PTSD, anger and alcohol misuse remained similar across the two time points, while significantly fewer veterans met criteria for CMDs 1 year later. A notable proportion of the sample reported challenges in attending mental and physical health appointments, which was positively associated with not working and negatively associated with more COVID-19-related stressors. CONCLUSIONS: These findings suggest that, to date, veterans with pre-existing mental health difficulties appear to demonstrate resilience as the COVID-19 pandemic progressed. However, as the pandemic continued, veterans faced significantly more COVID-19-related stressors, less social support, as well as difficulties attending health appointments.
Asunto(s)
Alcoholismo , COVID-19 , Veteranos , Humanos , Veteranos/psicología , Salud Mental , Pandemias , Estudios Longitudinales , Alcoholismo/psicología , COVID-19/epidemiología , Control de Enfermedades Transmisibles , Reino Unido/epidemiologíaRESUMEN
Nonacog alfa, a recombinant factor IX (FIX) used for the treatment of haemophilia B, was approved in Europe in 1998. In accordance with European Medicines Agency requirements, a registry study was conducted from 2002 to 2009. A reformulated iso-osmotic version was approved for European use in 2007. This study was conducted to evaluate the safety of nonacog alfa in a usual care setting, and provide clinical trial and postmarketing surveillance data support. This open-label, non-interventional, prospective observational cohort study (registry) comprised 52 sites in nine European countries. Patients with haemophilia B receiving nonacog alfa in either formulation for prevention or treatment were followed on a usual care schedule. A total of 218 patients were enrolled, of whom 66 (30.3%) were <18 years of age. Haemophilia severity was evenly distributed, with baseline FIX activity of <1%, 1-5% and >5% in 33.3%, 36.6% and 30.1% of patients, respectively. One hundred thirty-eight patients received the original formulation alone; 80 switched to or received only the new formulation. There was a low incidence of events of special interest (ESIs), with less-than-expected therapeutic effect in five patients (2.2%), inhibitor development in two (0.9%), thrombosis in one (0.5%) and allergic events in eight (3.7%). These accounted for the majority of the 15 serious AEs reported in six patients. Six patients discontinued because of AEs, primarily related to hypersensitivity. Nonacog alfa was shown to be safe for the treatment of haemophilia B, with a low incidence of serious AEs and ESIs.
Asunto(s)
Coagulantes/uso terapéutico , Factor IX/uso terapéutico , Hemofilia B/tratamiento farmacológico , Sistema de Registros , Adolescente , Adulto , Anciano , Niño , Preescolar , Coagulantes/efectos adversos , Europa (Continente) , Factor IX/efectos adversos , Femenino , Humanos , Lactante , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Proteínas Recombinantes/efectos adversos , Proteínas Recombinantes/uso terapéutico , Adulto JovenRESUMEN
INTRODUCTION: Research has shown that the likelihood of ex-military personnel developing mental health problems following service is around one in five. Little is known about the barriers to accessing mental health in veterans from diverse ethnic backgrounds. This study aims to explore mental health treatment experiences of veterans from commonwealth countries and therefore diverse ethnic backgrounds. METHODS: Semi-structured interviews were conducted over the telephone with veterans from commonwealth countries. Veterans were recruited from a mental health charity and were at various stages of treatment. RESULTS: We interviewed six veterans who were from a diverse range of commonwealth countries including St Lucia, Gambia, Ghana, Fiji and South Africa. All had served in the UK army in combat roles. Our findings consisted of key themes: (1) feeling that they are treated differently, (2) they felt as though they were unheard when reaching out for help, (3) systemic pressures such as financial difficulties, missed opportunities and lack of insight about mental health and (4) the importance of involving the wider community in care. CONCLUSION: Our findings highlight some distinct barriers to mental health treatment that commonwealth veterans experience. The themes reported by the participants appear to suggest they had experience signs of institutional racism. Suggesting the importance of highlighting these issues, and to help overcome these potential barriers to accessing services. Given that commonwealth veterans involvement in the UK military is significant and increasing, the findings in this study should be used to support this population by implementing service provision and policy.
Asunto(s)
Personal Militar , Veteranos , Humanos , Salud Mental , Racismo Sistemático , Reino UnidoRESUMEN
INTRODUCTION: Data are emerging showing the adverse consequences on mental health of the general public due to the COVID-19 pandemic. Little is known about the needs of veterans with pre-existing mental health difficulties during the COVID-19 pandemic. METHODS: Data were collected through a cross-sectional online survey from a randomly selected sample (n=1092) of military veterans who have sought help for mental health difficulties from a veteran-specific UK-based charity. The response rate was 25.2% (n=275). Participants were asked to complete a range of standardised mental health outcomes (post-traumatic stress disorder (PTSD): Post-traumatic Stress Disorder Checklist, common mental health difficulties (CMDs): 12-Item General Health Questionnaire, difficulties with anger: 5-Item Dimensions of Anger Reactions-Revised and alcohol misuse: Alcohol Use Disorders Identification Test) and endorse a list of potential stressors related to changes to daily life resulting from COVID-19. Regression analyses were fitted to explore predictors of mental health severity. RESULTS: It was observed that symptoms of common mental disorder and PTSD (69.3% and 65.0%, respectively) were the most commonly reported to have been exacerbated by the pandemic. Lack of social support and reporting increasing numbers of stressors related to COVID-19 were consistently associated with increasing severity of a range of mental health difficulties. CONCLUSIONS: Our findings suggest veterans who had pre-existing mental health difficulties prior to the outbreak of COVID-19 may be at increased risk of experiencing CMDs as a result of the pandemic. Intervening to improve levels of social support and offering practical guidance to better manage any additional stressors relating to the pandemic may provide strategies to help reduce the burden of mental health symptoms.
Asunto(s)
Alcoholismo , COVID-19 , Veteranos , Estudios Transversales , Humanos , Salud Mental , Pandemias , Distanciamiento Físico , SARS-CoV-2RESUMEN
BACKGROUND: COVID-19 transmission and disease dynamics in sub-Saharan Africa are not well understood. Our study aims to provide insight into COVID-19 epidemiology in Malawi by estimating SARS-CoV-2 prevalence and immunity after SARS-CoV-2 infection in a hospital-based setting. METHODS: We conducted a hospital-based, convenience sampling, cross-sectional survey for SARS-CoV-2 in Lilongwe, Malawi. Participants answered a questionnaire and were tested for SARS-CoV-2 by enzyme-linked immunosorbent assay and real-time reverse-transcription polymerase chain reaction (RT-PCR). A surrogate virus neutralization test (sVNT) was performed in seropositive samples to estimate immunity. Poisson regression was used to assess SARS-CoV-2 point prevalence association with demographic and behavioral variables. FINDINGS: The study included 930 participants. We found a combined point prevalence of 10.1%. Separately analyzed, RT-PCR positivity was 2.0%, and seropositivity was 9.3%. Of tested seropositive samples, 90.1% were sVNT positive. We found a high rate (45.7%) of asymptomatic SARS-CoV-2 infection. SARS-CoV-2 point prevalence was significantly associated with being a healthcare worker. INTERPRETATION: Our study suggests that official data underestimate COVID-19 transmission. Using sVNTs to estimate immunity in Malawi is feasible and revealed considerable post-infection immunity in our cohort. Subclinical infection and transmission are probably a game-changer in surveillance, mitigation and vaccination strategies.
Asunto(s)
COVID-19 , SARS-CoV-2 , COVID-19/epidemiología , Estudios Transversales , Hospitales , Humanos , Malaui/epidemiología , PrevalenciaRESUMEN
Aggregation (AGN) of freshly precipitated calcium oxalate crystals was photometrically studied in urine of 30 calcium stone patients and 30 controls, in solutions containing urinary macromolecules (UMS) and in an inhibitor free control solution (CS). Crystals were produced by oxalate titration and crystallization was monitored measuring optical density (OD). Tests were repeated adding hydroxyapatite (HAP) to urine and UMS and adding citrate and pyrophosphate (PPi) to UMS of the controls. AGN was recognized as a rapid OD decrease being at least three times faster than sedimentation of single crystals (p < 0.001) and used to calculate an extent of AGN (EA%). The time between the end of titration and the beginning of AGN was determined as suspension stability (SS). The main effect of urinary inhibitors was retardation of AGN without changing EA, SS being higher in urine than UMS (p < 0.001) and in UMS than CS (p < 0.001). In urine of 63% of controls but only in 33% of patients, no AGN was recorded (p < 0.05). The high inhibitory activity of urine could not be reproduced in UMS even in combination with 3.5 mM citrate or 0.05 mM PPi. 0.05 mg/mL HAP reduced SS in all urine samples to low values and increased the rate of rapid OD decrease, being a measure for the size of aggregates. Retarding AGN of crystals during their passage through the kidney seems to be an important mechanism to prevent stone formation during crystalluria. The promotion of AGN by HAP reveals a new role of Randall's plaques in nephrolithiasis.
Asunto(s)
Oxalato de Calcio/orina , Sustancias Macromoleculares/orina , Nefrolitiasis/orina , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Casos y Controles , Ácido Cítrico/orina , Cristalización , Difosfatos/orina , Durapatita/orina , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto JovenRESUMEN
Inhalation of particulate matter is hypothesized to contribute to health effects by overproducing reactive oxygen species (ROS) and inducing oxidative stress. Fe(II) has been shown to contribute to ROS generation in acellular simulated lung fluids. Atmospheric humic-like substances (HULIS) have been shown to chelate Fe(II) and significantly enhance this ROS generation. Here, we investigate Fe(II)-mediated .OH generation from the iron active proteins in lung fluid, albumin and transferrin, and fulvic acid, a surrogate for HULIS, in human bronchoalveolar lavage fluid (BALF). We find that albumin enhances .OH generation from inorganic Fe(II) and that transferrin attenuates this enhancement. We estimate the rate constants for albumin-Fe(II) and fulvic acid-Fe(II) mediated O2.- reduction (1.9 ± 0.3) M-1 s-1 and (2.7 ± 0.3) M-1s-1 (pH = 5.5, T = 37 °C), 17-25 times the rate for free iron, which we measured to be (110 ± 20) × 10-3 M-1s-1, in agreement with the literature. .OH generation measured from fulvic acid-Fe(II) in BALF from 8 individuals with added fulvic acid is successfully predicted rates of .OH generation by mixtures of Fe(II), albumin, transferrin, fulvic acid, and ascorbate in saline solution. This indicates that fulvic acid enhances .OH formation in BALF, and that albumin and transferrin in BALF moderate the effect. We propose that fulvic acid, and thereby HULIS, is capable of mobilizing Fe(II) away from albumin and transferrin and this increases the formation rate of O2.- and ultimately of .OH. Furthermore, we find that albumin and transferrin have significantly different impacts on Fe(II)-mediated .OH than citrate, a common component of simulated lung fluids, a factor that should be considered carefully in the interpretation of results obtained from solutions containing citrate.
Asunto(s)
Sustancias Húmicas , Hierro , Albúminas , Humanos , Sustancias Húmicas/análisis , Pulmón , Oxidación-Reducción , TransferrinaRESUMEN
BACKGROUND: Our previous study has shown that nuclear factor-kappa B (NF-kappaB)-signaling pathway was associated with a higher rate of recurrence in head and neck squamous cell carcinoma (HNSCC). The combination of bortezomib, an NF-kappaB inhibitor by inhibition of proteasomes, plus docetaxel was assessed for efficacy and toxicity. MATERIALS AND METHODS: Patients with recurrent and/or metastatic HNSCC were enrolled on a phase II bortezomib/docetaxel trial (bortezomib 1.6 mg/m(2) and docetaxel 40 mg/m(2) on days 1 and 8 of a 21-day cycle). Response was assessed using RECIST. Tissue specimens were evaluated for the presence of human papillomavirus (HPV) and expression of NF-kappaB-associated genes. RESULTS: Twenty-one of 25 enrolled patients were assessable for response; one partial response (PR, 5%), 10 stable disease (SD, 48%) and 10 progressive disease (PD, 48%). Patients with PR/SD had significantly longer survival compared with patients with PD and the regimen was well tolerated. Only one of 20 tumors was positive for HPV. Patients with PD had higher expression of NF-kappaB and epidermal growth factor receptor-associated genes in their tumors by gene expression analysis. CONCLUSION: Further understanding of treatment resistance and interactions between bortezomib and docetaxel may provide novel approaches in managing HNSCC.
Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Ácidos Borónicos/administración & dosificación , Carcinoma de Células Escamosas/tratamiento farmacológico , Neoplasias de Cabeza y Cuello/tratamiento farmacológico , FN-kappa B/antagonistas & inhibidores , Pirazinas/administración & dosificación , Taxoides/administración & dosificación , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Biomarcadores Farmacológicos/análisis , Biomarcadores Farmacológicos/metabolismo , Ácidos Borónicos/efectos adversos , Bortezomib , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/mortalidad , Docetaxel , Femenino , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Neoplasias de Cabeza y Cuello/genética , Neoplasias de Cabeza y Cuello/mortalidad , Humanos , Masculino , Persona de Mediana Edad , FN-kappa B/fisiología , Metástasis de la Neoplasia , Pirazinas/efectos adversos , Recurrencia , Transducción de Señal/efectos de los fármacos , Transducción de Señal/fisiología , Análisis de Supervivencia , Taxoides/efectos adversos , Resultado del TratamientoRESUMEN
A furnace was developed and characterized to allow for safe and controlled gas-loading or degassing of alloys. This oven is able to process samples under varying atmospheres, such as high vacuum or nitrogen containing 10 vol. % deuterium, as well as for pressures up to 800 hPa. Thermal desorption spectroscopy and scanning electron microscopy demonstrate the enhancing effects of high loading-gas concentration, high pressures, high temperatures above liquidus (50-150 K above the liquidus temperature of the cast hypoeutectic aluminum-copper model-alloy), and long holding times (up to 60 min) on the amount of retained gas in the solidified sample. Lack of copper segregation in the casting is confirmed by energy dispersive x-ray diffraction and Rutherford backscattering spectroscopy. It is shown that the facility allows for the controlled generation of distinct amounts of gas pores, down to a nil amount (only shrinkage porosity appearing in the sample).
RESUMEN
OBJECTIVES: In urine, aggregation (AGN) of crystal occurs although they are coated by negatively charged urinary macromolecules (UM) and isolated at a distance from each other, where attraction forces become extremely weak. Calcium (Ca) bridges or viscous binding by UM could explain this AGN. METHODS: Suspensions of Ca oxalate monohydrate (COM) and carboxylated latex (CL) were prepared in buffered water and UM solutions which were obtained from the urine of 6 healthy men. Surface potential or zetapotential (ZP) of the particles was measured at various concentrations of Ca and UM. AGN of CL was monitored determining particle size and optical density. RESULTS: The ZP of COM was neutralized by Ca and stabilized around -15 mV by UM. In CL, a stable ZP of about -20 mV was achieved at >3 mM Ca. However, to induce AGN further addition of Ca was necessary. AGN then increased independently of ZP with increasing Ca and decreased with increasing UM concentration. CONCLUSIONS: In CL, two different Ca effects could be distinguished, one on ZP and another on AGN. The latter is probably based on the formation of Ca bridges between particles and is inhibited by a steric barrier of adsorbed UM. A similar mechanism is postulated for crystal aggregation.
Asunto(s)
Calcio/química , Sustancias Macromoleculares/química , Sustancias Macromoleculares/orina , Fenómenos Bioquímicos , Cristalización , Humanos , MasculinoRESUMEN
The influence of different physical parameters, such as the source size and the energy spectrum, on the functional capability of a grating interferometer applied for phase-contrast imaging is discussed using numerical simulations based on Fresnel diffraction theory. The presented simulation results explain why the interferometer could be well combined with polychromatic laboratory x-ray sources in recent experiments. Furthermore, it is shown that the distance between the two gratings of the interferometer is not in general limited by the width of the photon energy spectrum. This implies that interferometers that give a further improved image quality for phase measurements can be designed, because the primary measurement signal for phase measurements can be increased by enlargement of this distance. Finally, the mathematical background and practical instructions for the quantitative evaluation of measurement data acquired with a polychromatic x-ray source are given.
RESUMEN
AIMS: We evaluated the possibility that repeated ischemic preconditioning or N-acetylcysteine (NAC) could prevent ischemia-reperfusion injury as determined by indocyanine green plasma disappearance rate (ICG-PDR) or has favorable hemodynamic effects during reperfusion in an in vivo canine liver model. METHODS: Under general anesthesia, 3 groups of mongrel dogs (n = 5 per group) were subjected to (1) 60-min hepatic ischemia, (2) same ischemia preceded by intravenous administration of 150 mg kg(-1) NAC, and (3) three episodes of IPC (10-min ischemia followed by 10-min reperfusion) prior to same ischemia. Hepatic reperfusion was maintained for a further 180 min, with hemodynamic and hepatic function parameters monitored throughout. RESULTS: Plasma disappearance rate of indocyanine green and serum levels of aspartate transferase and alanine transferase showed no significant differences between groups. Although liver injury was obvious, reflected by hemodynamic, blood gas, and liver function tests, NAC and IPC failed to prevent decay in hepatic function in this canine model. CONCLUSION: The results do not support the hypothesis that short-term use of NAC and IPC is beneficial in hepatic surgery.