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1.
Hernia ; 2024 Apr 16.
Artículo en Inglés | MEDLINE | ID: mdl-38625434

RESUMEN

PURPOSE: Risk of total extraperitoneal hernia repair (TEP) in patients with previous lower abdominal surgery (PLAS) is still debated. The present study was designed to assess the rate of conversion in TEP for inguinal hernia stratified by type of PLAS. METHODS: Variables on patients undergoing TEP inguinal hernia repair at our center were prospectively collected between July 2012 and May 2018. Patients with PLAS were compared to patients without PLAS. Furthermore, the most frequent subtypes of PLAS were defined and TEP conversion rate was stratified according to type of PLAS. RESULTS: A total of 1589 patients with TEP inguinal hernia repair were identified including 152 (9.6%) patients with PLAS. Operative time was increased in patients with PLAS (70 vs. 60 min, p < 0.001). Conversion from TEP to transabdominal preperitoneal patch plasty (TAPP) or Lichtenstein open inguinal hernia repair was eight-times more frequent after PLAS (8% vs. 1%, p < 0.001). Considering type of PLAS, open appendectomy was most frequently encountered, followed by multiple PLAS and surgery to the bladder and prostate (53%, 11% and 10%). After stratification for type of PLAS, conversions were most frequently found after previous surgery to the bladder or prostate and after multiple PLAS (conversion rate of 20% and 24%, p < 0.001). In contrast, conversion rate after open appendectomy was not increased. CONCLUSION: PLAS to the bladder and prostate is associated with TEP conversion. Selected patients might profit from a different operative approach for inguinal hernia repair.

2.
Gynecol Oncol ; 181: 170-178, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38215513

RESUMEN

Germline and somatic genetic testing have become critical components of care for people with ovarian cancer. The identification of germline and somatic pathogenic variants as well as homologous recombination deficiency can contribute to the prediction of treatment response, prognostic outcome, and suitability for targeted agents (e.g. poly (ADP-ribose) polymerase (PARP) inhibitors). Furthermore, identifying germline pathogenic variants can prompt cascade genetic testing for at-risk relatives. Despite the clinical benefits and consensus recommendations from several organizations calling for universal genetic testing in ovarian cancer, only about one third of patients complete germline or somatic genetic testing. The members of the Society of Gynecologic Oncology (SGO) Clinical Practice Committee have composed this statement to provide an overview of germline and somatic genetic testing for patients with epithelial ovarian cancer, focusing on available testing modalities and options for care delivery.


Asunto(s)
Antineoplásicos , Neoplasias Ováricas , Humanos , Femenino , Inhibidores de Poli(ADP-Ribosa) Polimerasas/uso terapéutico , Inhibidores de Poli(ADP-Ribosa) Polimerasas/farmacología , Neoplasias Ováricas/diagnóstico , Neoplasias Ováricas/genética , Neoplasias Ováricas/terapia , Carcinoma Epitelial de Ovario/terapia , Carcinoma Epitelial de Ovario/tratamiento farmacológico , Antineoplásicos/uso terapéutico , Mutación de Línea Germinal , Pruebas Genéticas , Poli(ADP-Ribosa) Polimerasas/genética , Poli(ADP-Ribosa) Polimerasas/uso terapéutico , Células Germinativas/patología , Proteína BRCA1/genética , Proteína BRCA2/genética
3.
Appl Ergon ; 97: 103546, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34399370

RESUMEN

This study investigates the effects of a dynamic seat pan design on sitting biomechanics, perceived pain and seat movement compared to a control. Thirty male participants were recruited for two experimental sessions consisting of a 2-h sitting exposure (standardized typing task). Spine angles, back muscle activity, perceived pain and calf circumference were measured pre and post exposure. Sitting in the dynamic condition resulted in lower pain ratings (p = 0.031), decreased calf circumference (p < 0.001), lower average seat pressure (p < 0.001), and greater seat contact area (p = 0.003) compared to the control. Spine angles and low back EMG for all 6 muscles showed no significant differences between chair conditions. These results suggest this dynamic seat pan design is effective at decreasing several negative components associated with sitting for the occupant. Future work should examine the longer-term effects of dynamic office chair features in the field setting with a more generalizable population.


Asunto(s)
Dolor de la Región Lumbar , Postura , Fenómenos Biomecánicos , Ergonomía , Humanos , Masculino , Percepción del Dolor , Columna Vertebral
4.
Pneumologie ; 74(12): 813-841, 2020 Dec.
Artículo en Alemán | MEDLINE | ID: mdl-33291162

RESUMEN

Long-term oxygen therapy is of great importance both for reducing mortality and for improving performance in patients with chronic lung diseases. The prerequisites for Long-term oxygen therapy are adequate diagnostics and clearly defined indication. A causal distinction into chronic hypoxaemic and hypercapnic respiratory failure is reasonable, from which the differential indication for non-invasive ventilation results.The revised guideline covers the diagnostics and indication of chronic lung and heart diseases, the role of oxygen in terminal illness and gives a detailed description of available oxygen devices. The guideline is intended to help avoid undersupply, oversupply and false prescriptions. Furthermore, the chapter "Postacute Oxygen Therapy" discusses the procedure, relevant in everyday life, but not yet clearly defined, for prescribing oxygen therapy for the home at the end of an inpatient stay. Another important point, the correct prescription of mobile oxygen systems, is also presented in the guideline. This document is a revised version of the guideline for longterm oxygen therapy and replaces the version of 2008.


Asunto(s)
Enfermedades Pulmonares , Ventilación no Invasiva , Terapia por Inhalación de Oxígeno/normas , Guías de Práctica Clínica como Asunto , Enfermedad Pulmonar Obstructiva Crónica/terapia , Insuficiencia Respiratoria , Sociedades Médicas/normas , Alemania , Humanos , Terapia por Inhalación de Oxígeno/métodos , Insuficiencia Respiratoria/diagnóstico , Insuficiencia Respiratoria/terapia , Factores de Tiempo
5.
Phys Rev Lett ; 125(5): 055701, 2020 Jul 31.
Artículo en Inglés | MEDLINE | ID: mdl-32794848

RESUMEN

We present a detailed investigation of the wave-vector dependence of collective atomic motion in Au_{49}Cu_{26.9}Si_{16.3}Ag_{5.5}Pd_{2.3} and Pd_{42.5}Cu_{27}Ni_{9.5}P_{21} supercooled liquids close to the glass transition temperature. Using x-ray photon correlation spectroscopy in a previously uncovered spatial range of only a few interatomic distances, we show that the microscopic structural relaxation process mimics the structure and presents a marked slowing down at the main average interparticle distance. This behavior is accompanied by dramatic changes in the shape of the intermediate scattering functions, which suggest the presence of large dynamical heterogeneities at length scales corresponding to a few particle diameters. A ballisticlike mechanism of particle motion seems to govern the structural relaxation of the two systems in the highly viscous phase, likely associated with hopping of caged particles in agreement with theoretical studies.

6.
ACS Appl Mater Interfaces ; 11(38): 35305-35311, 2019 Sep 25.
Artículo en Inglés | MEDLINE | ID: mdl-31454224

RESUMEN

Wood is increasingly considered in sustainable structural materials development due to its hierarchical structure, including an oriented reinforcing cellulose phase combined with carbon capturing and renewability. Top-down manufacturing techniques can provide direct access to this hierarchical cellulose scaffold for use in new functional materials. For high-performance load-bearing wood-based materials, the volume content of the reinforcing phase needs to be increased to much higher fiber volume contents (FVCs). This has been achieved by structure-retaining delignification followed by densification. The obtained matrix-free materials possess high tensile stiffness due to preservation of hierarchical fiber alignment; however, they demonstrate low mechanical properties in bending and cannot be used in moist conditions due to their propensity for water absorption. In order to address these two challenges, an interpenetrating wood polymer phase composite is developed using a delignified wood scaffold as a continuous reinforcing phase and epoxy resin as the interconnected matrix phase. We utilize the continuous flow channels in delignified wood for vacuum-assisted matrix infiltration in a condition of open continuous porosity in the wood scaffold. Prior to matrix curing, the material is densified in order to increase the FVC, decrease porosity, and reduce density variations in the wood scaffold. Due to the compressibility of delignified cellulose fibers, interpenetrating phase composites (IPCs) with very high FVCs of up to 80% could be produced, leading to exceptionally high tensile stiffness and strength of up to 70 GPa and 600 MPa. The obtained stiffness values far exceed the upper limit of the rule of mixtures due to an enhanced stress transfer through mechanically interlocked fiber-fiber interfaces combined with the stiffness providing matrix phase that further aids stress transfer between neighboring wood cells via their pits. This new approach paves the way for an efficient production of high-performance sustainable materials that can be used as alternative for glass fiber reinforced composites or natural fiber composites.

7.
Sci Rep ; 9(1): 11784, 2019 08 13.
Artículo en Inglés | MEDLINE | ID: mdl-31409803

RESUMEN

Atrioventricular nodal reentrant tachycardia (AVNRT) is the most common type of supraventricular tachycardia. Slow pathway (SP) ablation is the treatment of choice with a high acute success rate and a negligible periprocedural risk. However, long-term outcome data are scarce. The aim of this study was to assess long-term outcome and arrhythmia free survival after SP ablation. In this study, 534 consecutive patients with AVNRT, who underwent SP ablation between 1994 and 1999 were included. During a mean follow-up of 15.5 years, 101 (18.9%) patients died unrelated to the procedure or any arrhythmia. Data were collected by completing a questionnaire and/or contacting patients. Clinical information was obtained from 329 patients (61.6%) who constitute the final study cohort. During the electrophysiological study, sustained 1:1 slow AV nodal pathway conduction was eliminated in all patients. Recurrence of AVNRT was documented in 9 patients (2.7%), among those 7 patients underwent a successful repeat ablation procedure. New-onset atrial fibrillation (AF) was documented in 39 patients (11.9%) during follow-up. Pre-existing arterial hypertension (odds ratio 2.61, 95% CI 1.14-5.97, p = 0.023), age (odds ratio 1.05, 95% CI 1.02-1.09, p = 0.003) and the postinterventional AH interval (odds ratio 1.02, 95% CI 1.00-1.04, p = 0.038) predicted the occurrence of AF. The present long-term observational study after successful SP ablation of AVNRT confirms its clinical value reflected by low recurrence and complication rates. The unexpectedly high incidence of new-onset AF (11.9%) may impact long-term follow-up and requires further clinical attention.


Asunto(s)
Fibrilación Atrial/cirugía , Nodo Atrioventricular/cirugía , Ablación por Catéter/métodos , Taquicardia por Reentrada en el Nodo Atrioventricular/cirugía , Adolescente , Adulto , Anciano , Fibrilación Atrial/fisiopatología , Nodo Atrioventricular/fisiopatología , Niño , Electrocardiografía , Femenino , Estudios de Seguimiento , Frecuencia Cardíaca/fisiología , Humanos , Masculino , Persona de Mediana Edad , Encuestas y Cuestionarios , Taquicardia por Reentrada en el Nodo Atrioventricular/fisiopatología , Factores de Tiempo , Resultado del Tratamiento , Adulto Joven
8.
Nat Commun ; 9(1): 1476, 2018 04 16.
Artículo en Inglés | MEDLINE | ID: mdl-29662058

RESUMEN

The Northern Hemisphere experienced dramatic changes during the last glacial, featuring vast ice sheets and abrupt climate events, while high northern latitudes during the last interglacial (Eemian) were warmer than today. Here we use high-resolution aerosol records from the Greenland NEEM ice core to reconstruct the environmental alterations in aerosol source regions accompanying these changes. Separating source and transport effects, we find strongly reduced terrestrial biogenic emissions during glacial times reflecting net loss of vegetated area in North America. Rapid climate changes during the glacial have little effect on terrestrial biogenic aerosol emissions. A strong increase in terrestrial dust emissions during the coldest intervals indicates higher aridity and dust storm activity in East Asian deserts. Glacial sea salt aerosol emissions in the North Atlantic region increase only moderately (50%), likely due to sea ice expansion. Lower aerosol concentrations in Eemian ice compared to the Holocene are mainly due to shortened atmospheric residence time, while emissions changed little.

9.
J Eur Acad Dermatol Venereol ; 31(1): 163-168, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-27323701

RESUMEN

BACKGROUND: Rosacea is a chronic facial disease that may lead to feelings of stigmatization, which can negatively impact psychological and social well-being. OBJECTIVE: The aim of this study was to evaluate different aspects of rosacea that could contribute to feelings of stigmatization. METHODS: An online survey of a representative sample of the adult population in the UK, France, Germany and US was conducted to identify patients with rosacea based on presence of three or more clinical features. RESULTS: Among the patients who completed the survey (n = 807), mean age at first sign/symptom of rosacea was 31.3 ± 14.5 years; mean duration of disease was 102 ± 119 months. One-third of patients reported feelings of stigmatization (FS; n = 275). Male patients were more likely to experience FS (49% vs. 37.2% in non-FS population; P = 0.0037). Those with FS were more likely to avoid social situations (54.2% vs. 2.0%, P < 1.00E-10 ) and had a higher rate of depression (36.7% vs. 21.1%, P < 1.00E-10 ). CONCLUSIONS: Stigmatization is important in the daily lives of those with rosacea and should be taken into consideration in the management of these patients.


Asunto(s)
Rosácea/psicología , Estereotipo , Humanos , Rosácea/fisiopatología
10.
Am J Physiol Gastrointest Liver Physiol ; 309(3): G135-45, 2015 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-26089336

RESUMEN

Loss of significant intestinal length from congenital anomaly or disease may lead to short bowel syndrome (SBS); intestinal failure may be partially offset by a gain in epithelial surface area, termed adaptation. Current in vivo models of SBS are costly and technically challenging. Operative times and survival rates have slowed extension to transgenic models. We created a new reproducible in vivo model of SBS in zebrafish, a tractable vertebrate model, to facilitate investigation of the mechanisms of intestinal adaptation. Proximal intestinal diversion at segment 1 (S1, equivalent to jejunum) was performed in adult male zebrafish. SBS fish emptied distal intestinal contents via stoma as in the human disease. After 2 wk, S1 was dilated compared with controls and villus ridges had increased complexity, contributing to greater villus epithelial perimeter. The number of intervillus pockets, the intestinal stem cell zone of the zebrafish increased and contained a higher number of bromodeoxyuridine (BrdU)-labeled cells after 2 wk of SBS. Egf receptor and a subset of its ligands, also drivers of adaptation, were upregulated in SBS fish. Igf has been reported as a driver of intestinal adaptation in other animal models, and SBS fish exposed to a pharmacological inhibitor of the Igf receptor failed to demonstrate signs of intestinal adaptation, such as increased inner epithelial perimeter and BrdU incorporation. We describe a technically feasible model of human SBS in the zebrafish, a faster and less expensive tool to investigate intestinal stem cell plasticity as well as the mechanisms that drive intestinal adaptation.


Asunto(s)
Adaptación Biológica/fisiología , Intestinos , Síndrome del Intestino Corto/metabolismo , Animales , Antimetabolitos/farmacología , Bromodesoxiuridina/farmacología , Proliferación Celular , Procedimientos Quirúrgicos del Sistema Digestivo/métodos , Modelos Animales de Enfermedad , Humanos , Factor I del Crecimiento Similar a la Insulina/metabolismo , Mucosa Intestinal/patología , Intestinos/patología , Intestinos/fisiopatología , Intestinos/cirugía , Masculino , Células Madre/fisiología , Pérdida de Peso , Pez Cebra , Proteínas de Pez Cebra/metabolismo
11.
Lung ; 193(1): 63-70, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25503750

RESUMEN

PURPOSE: Acute exacerbations (AE) in patients with COPD are associated with a decline in lung function, increased risk of hospitalization, and mortality. In this cross-sectional study we tested whether the level of objectively measured daily physical activity and exercise capacity are associated with the number of COPD exacerbations. METHODS: In 210 patients with COPD (67 % men; mean (SD) age: 63 (8) years) enrolled in The Obstructive Pulmonary Disease Outcomes Cohort of Switzerland (TOPDOCS) physical activity (PA) (steps per day, physical activity level, (PAL)), exercise capacity (6-min walking distance, (6MWD)), comorbidities, lung function, and medication were assessed. Differences between COPD patients with frequent (≥2 year) and infrequent (0-1 year) exacerbations were assessed. Univariate and multivariate analyses were performed to investigate whether the level of objectively measured daily physical activity and exercise capacity are associated with the number of COPD exacerbations. RESULTS: Patients with frequent AE had a significantly lower FEV1 and 6MWD compared to patients with infrequent AE. In univariate analysis, the number of exacerbations was inversely associated with FEV1, 6MWD, BMI, and smoking status while there was a positive association with RV/TLC and combined inhaled medication. However, there was no significant association with PAL and steps per day. In multivariate analysis, FEV1 and the use of combined inhaled medication were independently associated with the number of AE, after correction for covariates. CONCLUSIONS: The findings of this study imply that FEV1, independent of inhaled medication, is significantly associated with COPD exacerbations. Neither physical activity nor exercise capacity was independently associated with COPD exacerbations.


Asunto(s)
Tolerancia al Ejercicio , Pulmón/fisiopatología , Actividad Motora , Enfermedad Pulmonar Obstructiva Crónica/fisiopatología , Anciano , Distribución de Chi-Cuadrado , Comorbilidad , Estudios Transversales , Progresión de la Enfermedad , Prueba de Esfuerzo , Femenino , Volumen Espiratorio Forzado , Humanos , Pulmón/efectos de los fármacos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Enfermedad Pulmonar Obstructiva Crónica/diagnóstico , Enfermedad Pulmonar Obstructiva Crónica/tratamiento farmacológico , Enfermedad Pulmonar Obstructiva Crónica/epidemiología , Factores de Riesgo , Índice de Severidad de la Enfermedad , Suiza/epidemiología , Factores de Tiempo , Capacidad Pulmonar Total
12.
J Chem Phys ; 141(4): 044304, 2014 Jul 28.
Artículo en Inglés | MEDLINE | ID: mdl-25084907

RESUMEN

We study the relaxation dynamics of photoexcited Fe-II complexes dissolved in water and identify the relaxation pathway which the molecular complex follows in presence of a hydration shell of bound water at the interface between the complex and the solvent. Starting from a low-spin state, the photoexcited complex can reach the high-spin state via a cascade of different possible transitions involving electronic as well as vibrational relaxation processes. By numerically exact path integral calculations for the relaxational dynamics of a continuous solvent model, we find that the vibrational life times of the intermittent states are of the order of a few ps. Since the electronic rearrangement in the complex occurs on the time scale of about 100 fs, we find that the complex first rearranges itself in a high-spin and highly excited vibrational state, before it relaxes its energy to the solvent via vibrational relaxation transitions. By this, the relaxation pathway can be clearly identified. We find that the life time of the vibrational states increases with the size of the complex (within a spherical model), but decreases with the thickness of the hydration shell, indicating that the hydration shell acts as an additional source of fluctuations.

14.
Anal Bioanal Chem ; 406(14): 3297-304, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24068171

RESUMEN

The use of electrospun nanofibers as functional material in paper-based lateral flow assays (LFAs) was studied. Specific chemical features of the nanofibers were achieved by doping the base polymer, poly(lactic acid) (PLA), with poly(ethylene glycol) (PEG) and polystyrene8K-block-poly(ethylene-ran-butylene)25K-block-polyisoprene10K-Brij76 (K3-Brij76) (KB). The LFAs were assembled such that the sample flowed through the nanofiber mat via capillary action. Initial investigations focused on the sustainable spinning and assembly of different polymer structures to allow the LFA format. Here, it was found that the base polymer poly(vinyl alcohol) (PVA), which was shown to function well in microfluidic biosensors, did not work in the LFA format. In contrast, PLA-based nanofibers enabled easy assembly. Three relevant features were chosen to study nanofiber-based functionalities in the LFA format: adsorption of antibodies, quantification of results, and nonspecific binding. In particular, streptavidin-conjugated sulforhodamine B (SRB)-encapsulating liposomes were captured by anti-streptavidin antibodies adsorbed on the nanofibers. Varying the functional polymer concentration within the PLA base enabled the creation of distinct capture zones. Also, a sandwich assay for the detection of Escherichia coli O157:H7 was developed using anti-E. coli antibodies as capture and reporter species with horseradish peroxidase for signal generation. A dose-response curve for E. coli with a detection limit of 1.9 × 10(4) cells was achieved. Finally, functional polymers were used to demonstrate that nonspecific binding could be eliminated using antifouling block copolymers. The enhancement of paper-based devices using functionalized nanofibers provides the opportunity to develop a broad spectrum of sensitive and specific bioassays with significant advantages over their traditional counterparts.


Asunto(s)
Técnicas Biosensibles , Electroquímica/métodos , Nanofibras , Papel , Adsorción , Anticuerpos/química , Escherichia coli/metabolismo , Escherichia coli O157/química , Peroxidasa de Rábano Silvestre/química , Inmunoensayo , Liposomas/química , Nanofibras/química , Polietilenglicoles/química , Polímeros/química , Poliestirenos/química , Alcohol Polivinílico/química , Unión Proteica , Rodaminas/química , Estreptavidina/química
15.
Bone Marrow Transplant ; 49(1): 138-44, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23933765

RESUMEN

Depletion of naive T cells from donor leukapheresis products (LPs) aims at the reduction of alloreactivity, while preserving memory T-cell reactivity (for example, to pathogens). This study established the immunomagnetic depletion procedure under clean room conditions using CD45RA beads and analyzed LPs of six donors for cell composition and functional immune responses. CD45RA depletion resulted in 3.4-4.7 log (median 4.4) reduction of CD45RA(+) T cells, thereby eliminating naive and late effector T cells. B cells were also completely removed, whereas significant proportions of NK cells, monocytes and granulocytes persisted. CD45RA-depleted LPs contained effector and central memory CD4(+) and CD8(+) T cells that showed sustained IFN-γ secretion to CMV, EBV, Aspergillus and Candida Ags. Alloreactivity was measured in MLRs between donors with complete HLA-mismatch. Alloreactive CD8(+) T cells were strongly reduced (median >1-log) upon CD45RA depletion, whereas alloreactive CD4(+) T cells persisted in significant numbers. In conclusion, clinical grade depletion of CD45RA(+) naive T cells from donor LPs is feasible and highly efficient. The depleted products show sustained CD4(+) and CD8(+) T-cell reactivity to pathogens and effectively reduced CD8-mediated alloreactivity. Prophylactic and preemptive infusions after allogeneic SCT may improve T-cell reconstitution and pathogen-specific immunosurveillance, along with lower risk of inducing GVHD.


Asunto(s)
Enfermedad Injerto contra Huésped/prevención & control , Separación Inmunomagnética/métodos , Antígenos Comunes de Leucocito/metabolismo , Depleción Linfocítica/métodos , Linfocitos T/inmunología , Adulto , Antígenos de Neoplasias/metabolismo , Aspergillus , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD8-positivos/inmunología , Candida , Citomegalovirus , Ensayo de Inmunoadsorción Enzimática , Citometría de Flujo , Herpesvirus Humano 4 , Humanos , Inmunofenotipificación , Interferón gamma/metabolismo , Leucaféresis/métodos , Depleción Linfocítica/instrumentación , Masculino
16.
J Chem Phys ; 139(13): 134503, 2013 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-24116571

RESUMEN

The relatively small dielectric Debye-like process of the monohydroxy alcohol 4-methyl-3-heptanol (4M3H) was found to depend slightly on the intramolecular conformation. Proton and deuteron nuclear magnetic resonance demonstrate that the hydroxyl dynamics and the overall molecular dynamics take place on similar time scales in contrast to the situation for the structural isomer 2-ethyl-1-hexanol (2E1H) [S. Schildmann et al., J. Chem. Phys. 135, 174511 (2011)]. This indicates a very weak decoupling of Debye-like and structural relaxation which was further probed using volume expansivity experiments. Shear viscosity as well as diffusometry measurements were performed and the data were analyzed in terms of the Debye-Stokes-Einstein equations. In mixtures of 4M3H with 2E1H the Debye-like process becomes much stronger and for 2E1H mole fraction of more than 25% the behavior of this alcohol is rapidly approached. This finding is interpreted to indicate that the ring-like supramolecular structures in 4M3H become energetically unfavorable when adding 2E1H, an alcohol that tends to form chain-like molecular aggregates. The concentration dependence of the Kirkwood factor in these mixtures displays a high degree of similarity with experimental results on monohydroxy alcohols in which the pressure or the location of the OH group within the molecular structure is varied.

17.
J Phys Chem B ; 117(40): 12164-74, 2013 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-24020428

RESUMEN

Deuteron nuclear magnetic resonance (NMR) and dielectric spectroscopy are utilized to investigate the dynamics in sulfuric acid hydrates as well as in nitric acid hydrates for various degrees of hydration. Near the glass transition temperature the electrical response is up to four decades faster than the calorimetric one, a feature found also for several other inorganic ionic liquids. The acid hydrates display pronounced super-Arrhenius behavior with fragility indices of the order of 100. The relaxation strength of the acid hydrates increases with increasing temperature, an observation that was rationalized with reference to the degree of molecular dissociation. Spin relaxometry and stimulated-echo spectroscopy revealed an overall isotropic reorientation process featuring a jump angle of about 30°. Finally, the implications of the present results for the understanding of the glass transition of pure ultraviscous water are discussed.

18.
Cell Death Dis ; 4: e608, 2013 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-23618906

RESUMEN

Aggregates of amyloid-beta (Aß) and tau are hallmarks of Alzheimer's disease (AD) leading to neurodegeneration and synaptic loss. While increasing evidence suggests that inhibition of N-methyl-D-aspartate receptors (NMDARs) may mitigate certain aspects of AD neuropathology, the precise role of different NMDAR subtypes for Aß- and tau-mediated toxicity remains to be elucidated. Using mouse organotypic hippocampal slice cultures from arcAß transgenic mice combined with Sindbis virus-mediated expression of human wild-type tau protein (hTau), we show that Aß caused dendritic spine loss independently of tau. However, the presence of hTau was required for Aß-induced cell death accompanied by increased hTau phosphorylation. Inhibition of NR2B-containing NMDARs abolished Aß-induced hTau phosphorylation and toxicity by preventing GSK-3ß activation but did not affect dendritic spine loss. Inversely, NR2A-containing NMDAR inhibition as well as NR2A-subunit knockout diminished dendritic spine loss but not the Aß effect on hTau. Activation of extrasynaptic NMDARs in primary neurons caused degeneration of hTau-expressing neurons, which could be prevented by NR2B-NMDAR inhibition but not by NR2A knockout. Furthermore, caspase-3 activity was increased in arcAß transgenic cultures. Activity was reduced by NR2A knockout but not by NR2B inhibition. Accordingly, caspase-3 inhibition abolished spine loss but not hTau-dependent toxicity in arcAß transgenic slice cultures. Our data show that Aß induces dendritic spine loss via a pathway involving NR2A-containing NMDARs and active caspase-3 whereas activation of eSyn NR2B-containing NMDARs is required for hTau-dependent neurodegeneration, independent of caspase-3.


Asunto(s)
Péptidos beta-Amiloides/metabolismo , Espinas Dendríticas/metabolismo , Hipocampo/metabolismo , Neuronas/metabolismo , Receptores de N-Metil-D-Aspartato/metabolismo , Péptidos beta-Amiloides/genética , Animales , Apoptosis , Caspasa 3/metabolismo , Células Cultivadas , Glucógeno Sintasa Quinasa 3/metabolismo , Glucógeno Sintasa Quinasa 3 beta , Hipocampo/citología , Humanos , Técnicas In Vitro , Ratones , Ratones Noqueados , Ratones Transgénicos , Neuronas/citología , Fosforilación , Receptores de N-Metil-D-Aspartato/antagonistas & inhibidores , Receptores de N-Metil-D-Aspartato/genética , Proteínas tau/genética , Proteínas tau/metabolismo
19.
Respiration ; 85(2): 160-74, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23406723

RESUMEN

The new Swiss Chronic Obstructive Pulmonary Disease (COPD) Guidelines are based on a previous version, which was published 10 years ago. The Swiss Respiratory Society felt the need to update the previous document due to new knowledge and novel therapeutic developments about this prevalent and important disease. The recommendations and statements are based on the available literature, on other national guidelines and, in particular, on the GOLD (Global Initiative for Chronic Obstructive Lung Disease) report. Our aim is to advise pulmonary physicians, general practitioners and other health care workers on the early detection and diagnosis, prevention, best symptomatic control, and avoidance of COPD as well as its complications and deterioration.


Asunto(s)
Enfermedad Pulmonar Obstructiva Crónica/diagnóstico , Enfermedad Pulmonar Obstructiva Crónica/terapia , Agonistas de Receptores Adrenérgicos beta 2/uso terapéutico , Antibacterianos/uso terapéutico , Broncodilatadores/uso terapéutico , Antagonistas Colinérgicos/uso terapéutico , Presión de las Vías Aéreas Positiva Contínua , Ejercicio Físico , Expectorantes/uso terapéutico , Glucocorticoides/uso terapéutico , Humanos , Vacunas contra la Influenza , Oximetría , Terapia por Inhalación de Oxígeno , Educación del Paciente como Asunto , Inhibidores de Fosfodiesterasa/uso terapéutico , Vacunas Neumococicas , Neumonectomía , Enfermedad Pulmonar Obstructiva Crónica/epidemiología , Radiografía Torácica , Pruebas de Función Respiratoria , Terapia Respiratoria , Factores de Riesgo , Autocuidado , Apoyo Social , Encuestas y Cuestionarios , Tomografía Computarizada por Rayos X , Aumento de Peso , alfa 1-Antitripsina/uso terapéutico
20.
Eur J Radiol ; 82(1): 51-5, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-21899972

RESUMEN

Peripheral neural sheath tumors (PNST) are rare and the common goal of management focuses on eliminating pain and maximizing function of the affected nerve. Therefore preoperative assessment of the specific morphological behaviour of such tumors regarding the nerves internal architecture is of utmost importance. PNSTs may affect one or more fascicles of a peripheral nerve resulting in a significant functional loss after resection and the necessity of functional reconstruction in one step. Enhancement of preoperative information should also address the biological behaviour of the tumor regarding its dignity and the resulting implications on amount of radical resection, additional treatment and prognosis. Since high-resolution techniques promise more and more detail resolution in many fields of imaging, delineation of intra- and extraneural processes as well as biological informations shall lead towards a well prepared and foreseeable image-guided treatment of PNSTs.


Asunto(s)
Imagen por Resonancia Magnética/métodos , Neoplasias de la Vaina del Nervio/diagnóstico , Neoplasias del Sistema Nervioso Periférico/diagnóstico , Ultrasonografía/métodos , Humanos
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