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1.
Animal ; 18(6): 101168, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38762992

RESUMEN

Heat stress (HS) negatively impacts a variety of production parameters in growing pigs; however, the impact of biological sex on the HS response is largely unknown. To address this, 48 crossbred barrows and gilts (36.8 ± 3.7 kg BW) were individually housed and assigned to one of three constant environmental conditions: (1) thermoneutral (TN) (20.8 ± 1.6 °C; 62.0 ± 4.7% relative humidity; n = 8/sex), (2) HS (39.4 ± 0.6 °C; 33.7 ± 6.3% relative humidity) for 1 d (HS1; n = 8/sex), or (3) or for 7 d (HS7; n = 8/sex). As expected, HS increased rectal temperature (Tr) following 1 d of HS (1.0 °C; P < 0.0001) and 7 d of HS (0.9 °C; P < 0.0001). By 7 d, heat-stressed gilts were cooler than barrows (0.4 °C; P = 0.016), despite identical heating conditions. There was a main effect of sex such that barrows had higher Tr than gilts (P = 0.031). Heat-stressed pigs on d 1 had marked reductions in feed intake and BW compared to TN (P < 0.0001). One day of HS resulted in negative gain to feed (G:F) in barrows and gilts and was reduced compared to TN (P < 0.0001). Notably, following 1 d of HS, the variability of G:F was greater in gilts than in barrows. Between 1 and 7 d of HS, G:F improved in barrows and gilts and were similar to TN pigs, even though HS barrows had higher Tr than gilts over this period. Heat stress for 1 and 7 d reduced empty gastrointestinal tract weight compared to TN (P < 0.0001). Interestingly, HS7 gilts had decreased gastrointestinal tract weight compared to HS1 gilts (2.43 vs 2.72 kg; P = 0.03), whereas it was similar between HS1 and HS7 barrows. Lastly, a greater proportion of gastrointestinal contents was in the stomach of HS1 pigs compared to TN and HS7 (P < 0.05), which is suggestive of decreased gastric emptying. Overall, HS barrows maintained an elevated Tr compared to HS gilts through the duration of the experiment but also maintained similar growth and production metrics compared to gilts, despite this higher temperature.


Asunto(s)
Respuesta al Choque Térmico , Calor , Animales , Femenino , Masculino , Porcinos/fisiología , Porcinos/crecimiento & desarrollo , Calor/efectos adversos , Respuesta al Choque Térmico/fisiología , Temperatura Corporal , Trastornos de Estrés por Calor/veterinaria , Factores Sexuales , Enfermedades de los Porcinos , Sus scrofa/fisiología , Sus scrofa/crecimiento & desarrollo
2.
J Dairy Sci ; 106(8): 5825-5834, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37349209

RESUMEN

Heat stress (HS) markedly affects postabsorptive energetics and protein metabolism. Circulating urea nitrogen increases in multiple species during HS and it has been traditionally presumed to stem from increased skeletal muscle proteolysis; however, this has not been empirically established. We hypothesized HS would increase activation of the calpain and proteasome systems as well as increase degradation of autophagosomes in skeletal muscle. To test this hypothesis, lactating dairy cows (~139 d in milk; parity ~2.4) were exposed to thermal neutral (TN) or HS conditions for 7 d (8 cows/environment). To induce HS, cattle were fitted with electric blankets for the duration of the heating period and the semitendinosus was biopsied on d 7. Heat stress increased rectal temperature (1.3°C) and respiratory rate (38 breaths per minute) while it decreased dry matter intake (34%) and milk yield (32%). Plasma urea nitrogen (PUN) peaked following 3 d (46%) and milk urea nitrogen (MUN) peaked following 4 d of environmental treatment and while both decreased thereafter, PUN and MUN remained elevated compared with TN (PUN: 20%; MUN: 27%) on d 7 of HS. Contrary to expectations, calpain I and II abundance and activation and calpain activity were similar between groups. Likewise, relative protein abundance of E3 ligases, muscle atrophy F-box protein/atrogin-1 and muscle ring-finger protein-1, total ubiquitinated proteins, and proteasome activity were similar between environmental treatments. Finally, autophagosome degradation was also unaltered by HS. Counter to our hypothesis, these results suggest skeletal muscle proteolysis is not increased following 7 d of HS and call into question the presumed dogma that elevated skeletal muscle proteolysis, per se, drives increased AA mobilization.


Asunto(s)
Lactancia , Complejo de la Endopetidasa Proteasomal , Embarazo , Femenino , Bovinos , Animales , Lactancia/fisiología , Proteolisis , Complejo de la Endopetidasa Proteasomal/metabolismo , Calpaína/metabolismo , Calpaína/farmacología , Leche/metabolismo , Respuesta al Choque Térmico , Músculo Esquelético/metabolismo , Urea/metabolismo , Dieta/veterinaria
3.
J Photochem Photobiol B ; 189: 185-192, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30390525

RESUMEN

In vitro standard methods are available and accepted worldwide to assess UVA protection of sunscreen products. Though, harmonisation of methods has made progress in the last decade, still two differing methods - one by FDA the other by ISO - are in use. In a multicentre study including 9 centres in Germany, 4 different commercial sunscreen products were assessed using both methods to discover their similarities and differences. UVA protection factor and Critical Wavelength were detected at various substrate type (sandblasted versus moulded PMMA plates), at different surface roughness of the plates as well as at different product application dose using two different irradiation spectra. Results: The strongest influence on UVA protection factor results from the surface roughness of the plates. Depending on the roughness (accepted range of 2 to 7 µm in the FDA method) a variability in the UVA protection factor of up to 25% was observed, while the much narrower definition of plate roughness by ISO (4.5 to 5.2 µm) had no relevant influence on the test results. Sandblasted plates in our assessment led to higher UVA protection factors and produced less scattered results compared to moulded plates. These differences were not pronounced. Application dose and spectra of the irradiation source were of negligible influence on UVA protection factor results for the investigated UV-filter combinations. The UVA protection factor which is the endpoint of the ISO method was found to be a parameter with a high potential to differentiate among different test products. The endpoint of the FDA method - the Critical Wavelength - was found to be an unambitious endpoint. Insensitivity to all described modifications of the method was observed. All investigated products performed similar and passed the Critical Wavelength criteria independent of method and parameters.


Asunto(s)
Técnicas In Vitro/métodos , Protectores Solares/normas , Rayos Ultravioleta/efectos adversos , Alemania , Sustancias Protectoras/normas , Piel/efectos de la radiación , Propiedades de Superficie , Estados Unidos , United States Food and Drug Administration
4.
Opt Express ; 25(21): 26067-26075, 2017 Oct 16.
Artículo en Inglés | MEDLINE | ID: mdl-29041268

RESUMEN

Generating N single photons simultaneously is a formidable challenge due to the lack of deterministic single photon sources. Recent work [New J. Phys. 19, 063013 (2017] has proposed a relative multiplexing scheme that can enhance the N single photons probability with a minimum of active switching resources. We experimentally demonstrate relative temporal multiplexing on two photon sources with a 90% additional enhancement over the standard temporal multiplexing scheme demonstrated previously. 88 ± 11% visibility of Hong-Ou-Mandel quantum interference verifies the indistinguishability of the heralded single photons after the synchronization. This proof-of-principle demonstration points out the potential significance of the relative multiplexing scheme for large-scale photonic quantum information processing.

5.
Herz ; 41(2): 97-101, 2016 Mar.
Artículo en Alemán | MEDLINE | ID: mdl-26838062

RESUMEN

Transcatheter aortic valve implantation (TAVI) has become an established treatment for symptomatic aortic valve stenosis in inoperable patients and high-risk patients. In Germany the TAVI procedure has now surpassed the annual numbers of isolated surgical aortic valve replacement with a recent trend towards treatment of intermediate-risk patients; however, before TAVI can also be used in patients with lower surgical risk, studies are required to demonstrate the safety and efficacy of this method for this patient population.


Asunto(s)
Estenosis de la Válvula Aórtica/mortalidad , Estenosis de la Válvula Aórtica/cirugía , Válvula Aórtica/cirugía , Prótesis Valvulares Cardíacas/estadística & datos numéricos , Complicaciones Posoperatorias/mortalidad , Reemplazo de la Válvula Aórtica Transcatéter/mortalidad , Medicina Basada en la Evidencia , Alemania/epidemiología , Humanos , Complicaciones Posoperatorias/prevención & control , Prevalencia , Factores de Riesgo , Tasa de Supervivencia , Reemplazo de la Válvula Aórtica Transcatéter/estadística & datos numéricos , Resultado del Tratamiento
6.
Phys Rev Lett ; 113(10): 100502, 2014 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-25238340

RESUMEN

We pose a randomized boson-sampling problem. Strong evidence exists that such a problem becomes intractable on a classical computer as a function of the number of bosons. We describe a quantum optical processor that can solve this problem efficiently based on a Gaussian input state, a linear optical network, and nonadaptive photon counting measurements. All the elements required to build such a processor currently exist. The demonstration of such a device would provide empirical evidence that quantum computers can, indeed, outperform classical computers and could lead to applications.

7.
Med Eng Phys ; 33(3): 340-6, 2011 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21130015

RESUMEN

The spine is a complex structure that provides motion in three directions: flexion and extension, lateral bending and axial rotation. So far, the investigation of the mechanical and kinematic behavior of the basic unit of the spine, a motion segment, is predominantly a domain of in vitro experiments on spinal loading simulators. Most existing approaches to measure spinal stiffness intraoperatively in an in vivo environment use a distractor. However, these concepts usually assume a planar loading and motion. The objective of our study was to develop and validate an apparatus, that allows to perform intraoperative in vivo measurements to determine both the applied force and the resulting motion in three dimensional space. The proposed setup combines force measurement with an instrumented distractor and motion tracking with an optoelectronic system. As the orientation of the applied force and the three dimensional motion is known, not only force-displacement, but also moment-angle relations could be determined. The validation was performed using three cadaveric lumbar ovine spines. The lateral bending stiffness of two motion segments per specimen was determined with the proposed concept and compared with the stiffness acquired on a spinal loading simulator which was considered to be gold standard. The mean values of the stiffness computed with the proposed concept were within a range of ±15% compared to data obtained with the spinal loading simulator under applied loads of less than 5 Nm.


Asunto(s)
Ensayo de Materiales/métodos , Fenómenos Mecánicos , Movimiento , Columna Vertebral/fisiología , Columna Vertebral/cirugía , Animales , Fenómenos Biomecánicos , Ensayo de Materiales/instrumentación , Ovinos , Soporte de Peso
8.
Skin Pharmacol Physiol ; 23(4): 201-12, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20215813

RESUMEN

In the past, several attempts have been made to develop in vitro methods for determining protection against UV radiation. To date however, there is no broadly accepted method. Various known and unknown parameters influence the transmission measurements of scattering films, such as the multifaceted compositions of sunscreens, the technical limitations of measurement devices as well as the difficulty to apply very thin films of sunscreen in a reproducible manner throughout different laboratories. In vitro data were measured in this multicenter study to compare possible methodologies and strategies for an in vitro approach to the sun protection factor (SPF). This publication will not present a final in vitro SPF test method, but it will point out which technical side effects may influence such a method. Influential factors such as the quality of spectrophotometer used, the amount of product applied, pretreatment of samples, time and temperature of equilibration, size of the measured surface, the application process or the calculation on the basis of standardized data are presented and discussed. Finally, a reduction of the standard deviations within single laboratories could be realized for in vitro SPF testing, but no improvement of the interlaboratory comparison was obtained. The development of a valid and reliable SPF in vitro test still remains a challenge, and further work is necessary to develop a satisfactory method.


Asunto(s)
Ensayo de Materiales/normas , Luz Solar/efectos adversos , Protectores Solares/química , Administración Cutánea , Humanos , Técnicas In Vitro , Ensayo de Materiales/métodos , Espectrofotometría Ultravioleta/métodos , Espectrofotometría Ultravioleta/normas , Protectores Solares/administración & dosificación , Rayos Ultravioleta/efectos adversos
9.
Acta Anaesthesiol Scand ; 54(4): 521-3, 2010 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-20096021

RESUMEN

Caffeine is a natural alkaloid methylxanthine that is found in various plants such as coffee or tea. Symptoms of a severe overdose may present with hypokalemia, hyponatremia, ventricular arrhythmias, hypertension followed by hypotension, respiratory failure, seizures, rhabdomyolysis, ventricular fibrillation and finally circulatory collapse. A 21-year-old woman called for the ambulance herself soon after the ingestion of about 10,000 mg of caffeine. At the arrival of the ambulance, the patient went into cardiac arrest almost immediately. After a total resuscitation period of 34 min including seven counter-shocks and 2 mg epinephrine, the patient was stable enough to be transferred to the hospital. The patient soon went into VF again and received two more counter-shocks and 1 mg epinephrine and finally an intravenous bolus dose of 300 mg amiodarone. The initial arterial blood gas showed pH at 6.47, lactate at 33 mmol/l and potassium level at 2.3 mmol/l. Unfortunately, no blood samples for caffeine analysis were taken. Three days after hospital admission, the patient developed myoclonus, which did not respond to medical treatment. Excessive intake of caffeine may produce arrhythmias and pronounced hypokalemia and ensuing ventricular fibrillation. In case of counter-shock-resistant VF, it can be necessary to give an early loading dose of amiodarone. Furthermore, it may be beneficial to replace the potassium as early as possible. Epinephrine and buffer solutions used during resuscitation may further decrease blood potassium levels and should be administrated cautiously. Epinephrine can be replaced by other vasopressor drugs, such as vasopressin without effects on beta-receptors.


Asunto(s)
Cafeína/envenenamiento , Estimulantes del Sistema Nervioso Central/envenenamiento , Amiodarona/uso terapéutico , Antiarrítmicos/uso terapéutico , Reanimación Cardiopulmonar , Cardioversión Eléctrica , Electrocardiografía , Resultado Fatal , Femenino , Paro Cardíaco/inducido químicamente , Paro Cardíaco/patología , Humanos , Hipopotasemia/inducido químicamente , Hipoxia Encefálica/inducido químicamente , Hipoxia Encefálica/patología , Neumonía/complicaciones , Fibrilación Ventricular/inducido químicamente , Desequilibrio Hidroelectrolítico/inducido químicamente , Adulto Joven
10.
Acta Neurol Scand ; 120(5): 347-52, 2009 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-19744135

RESUMEN

OBJECTIVE: To evaluate the long-term functional status and well-being in patients with chronic idiopathic polyneuropathy (CIP) in comparison to Guillain-Barré syndrome (GBS) and healthy controls. MATERIALS AND METHODS: Forty-two CIP and 42 GBS-patients were examined at median 5 and 6 years after disease onset and were compared with 50 healthy controls. The Fatigue Severity Scale (FSS), Visual Analogue Scale for pain (VAS), Disability Rating Index (DRI) and Medical Outcome Study 36-item short-form health status scale (SF-36) were used. Variables at onset and symptoms at follow-up were correlated with outcome measurements in GBS. RESULTS: Patients with CIP and GBS had more pain and disability than healthy controls. Additionally, CIP-patients were more fatigued than healthy controls. Patients with CIP were more fatigued [FSS 4.9 (SD 1.6) vs 3.8 (SD 1.8); P < 0.01] and disabled [DRI 4.1 (SD 2.3) vs 2.5 (SD 2.1); P = 0.05] than those with GBS. Physical functioning on the SF-36 was more impaired in CIP than GBS, compared with healthy controls. CONCLUSIONS: Patients with CIP and GBS seem to develop persistent impairment on long-term functional status and well-being, more clearly in CIP, reflecting the importance of long-term follow-up in further disease management.


Asunto(s)
Manejo de la Enfermedad , Síndrome de Guillain-Barré/fisiopatología , Estado de Salud , Polineuropatías/fisiopatología , Actividades Cotidianas , Adulto , Anciano , Enfermedad Crónica , Progresión de la Enfermedad , Fatiga/etiología , Femenino , Síndrome de Guillain-Barré/complicaciones , Humanos , Masculino , Persona de Mediana Edad , Polineuropatías/complicaciones , Calidad de Vida , Análisis de Regresión , Índice de Severidad de la Enfermedad , Encuestas y Cuestionarios , Resultado del Tratamiento
11.
Endocr Relat Cancer ; 16(4): 1219-27, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19690016

RESUMEN

A small subset of familial pancreatic endocrine tumors (PET) arises in patients with von Hippel-Lindau syndrome and these tumors may have an adverse outcome compared to other familial PET. Sporadic PET rarely harbors somatic VHL mutations, but the chromosomal location of the VHL gene is frequently deleted in sporadic PET. A subset of sporadic PET shows active hypoxia signals on mRNA and protein level. To identify the frequency of functionally relevant VHL inactivation in sporadic PET and to examine a possible prognostic significance we correlated epigenetic and genetic VHL alterations with hypoxia signals. VHL mutations were absent in all 37 PETs examined. In 2 out of 35 informative PET (6%) methylation of the VHL promoter region was detected and VHL deletion by fluorescence in situ hybridization was found in 14 out of 79 PET (18%). Hypoxia inducible factor 1alpha (HIF1-alpha), carbonic anhydrase 9 (CA-9), and glucose transporter 1 (GLUT-1) protein was expressed in 19, 27, and 30% of the 152 PETs examined. Protein expression of the HIF1-alpha downstream target CA-9 correlated significantly with the expression of CA-9 RNA (P<0.001), VHL RNA (P<0.05), and VHL deletion (P<0.001) as well as with HIF1-alpha (P<0.005) and GLUT-1 immunohistochemistry (P<0.001). These PET with VHL alterations and signs of hypoxia signalling were characterized by a significantly shortened disease-free survival. We conclude that VHL gene impairment by promoter methylation and VHL deletion in nearly 25% of PET leads to the activation of the HIF-pathway. Our data suggest that VHL inactivation and consecutive hypoxia signals may be a mechanism for the development of sporadic PET with an adverse outcome.


Asunto(s)
Metilación de ADN , Neoplasias de las Glándulas Endocrinas/genética , Eliminación de Gen , Mutación/genética , Neoplasias Pancreáticas/genética , Proteína Supresora de Tumores del Síndrome de Von Hippel-Lindau/genética , Antígenos de Neoplasias/genética , Antígenos de Neoplasias/metabolismo , Anhidrasa Carbónica IX , Anhidrasas Carbónicas/genética , Anhidrasas Carbónicas/metabolismo , Neoplasias de las Glándulas Endocrinas/metabolismo , Neoplasias de las Glándulas Endocrinas/patología , Transportador de Glucosa de Tipo 1/genética , Transportador de Glucosa de Tipo 1/metabolismo , Humanos , Subunidad alfa del Factor 1 Inducible por Hipoxia/genética , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Técnicas para Inmunoenzimas , Hibridación Fluorescente in Situ , Páncreas/metabolismo , Páncreas/patología , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patología , Pronóstico , Regiones Promotoras Genéticas , ARN Mensajero/genética , ARN Mensajero/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Tasa de Supervivencia , Proteína Supresora de Tumores del Síndrome de Von Hippel-Lindau/antagonistas & inhibidores , Proteína Supresora de Tumores del Síndrome de Von Hippel-Lindau/metabolismo
12.
Free Radic Biol Med ; 46(9): 1250-9, 2009 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-19353781

RESUMEN

Nitroalkene fatty acid derivatives manifest a strong electrophilic nature, are clinically detectable, and induce multiple transcriptionally regulated anti-inflammatory responses. At present, the characterization and quantification of endogenous electrophilic lipids are compromised by their Michael addition with protein and small-molecule nucleophilic targets. Herein, we report a trans-nitroalkylation reaction of nitro-fatty acids with beta-mercaptoethanol (BME) and apply this reaction to the unbiased identification and quantification of reaction with nucleophilic targets. Trans-nitroalkylation yields are maximal at pH 7 to 8 and occur with physiological concentrations of target nucleophiles. This reaction is also amenable to sensitive mass spectrometry-based quantification of electrophilic fatty acid-protein adducts upon electrophoretic resolution of proteins. In-gel trans-nitroalkylation reactions also permit the identification of protein targets without the bias and lack of sensitivity of current proteomic approaches. Using this approach, it was observed that fatty acid nitroalkenes are rapidly metabolized in vivo by a nitroalkene reductase activity and mitochondrial beta-oxidation, yielding a variety of electrophilic and nonelectrophilic products that could be structurally characterized upon BME-based trans-nitroalkylation reaction. This strategy was applied to the detection and quantification of fatty acid nitration in mitochondria in response to oxidative inflammatory conditions induced by myocardial ischemia-reoxygenation.


Asunto(s)
Alquenos/análisis , Ácidos Grasos/metabolismo , Mitocondrias Cardíacas/química , Nitrocompuestos/análisis , Animales , Bioquímica/métodos , Dimerización , Ácidos Grasos/química , Masculino , Mercaptoetanol/química , Ratones , Ratones Endogámicos C57BL , Mitocondrias Cardíacas/metabolismo , Isquemia Miocárdica/metabolismo , Isquemia Miocárdica/patología , Oxidación-Reducción , Estrés Oxidativo , Oxidorreductasas/metabolismo , Ratas , Sensibilidad y Especificidad , Espectrometría de Masas en Tándem
13.
Phys Rev Lett ; 103(24): 240504, 2009 Dec 11.
Artículo en Inglés | MEDLINE | ID: mdl-20366191

RESUMEN

We introduce and implement a technique to extend the quantum computational power of cluster states by replacing some projective measurements with generalized quantum measurements (POVMs). As an experimental demonstration we fully realize an arbitrary three-qubit cluster computation by implementing a tunable linear-optical POVM, as well as fast active feedforward, on a two-qubit photonic cluster state. Over 206 different computations, the average output fidelity is 0.9832+/-0.0002; furthermore the error contribution from our POVM device and feedforward is only of O(10(-3)), less than some recent thresholds for fault-tolerant cluster computing.

14.
Eur J Neurol ; 15(12): 1332-7, 2008 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19049550

RESUMEN

BACKGROUND AND PURPOSE: The purpose of this study was to analyse the long-term impact of Guillain-Barré syndrome (GBS) on quality of life, and the relationship between clinical variables at disease onset and symptoms at follow-up to general health status. METHODS: Forty-two GBS patients were examined at median 6 years after disease onset and were compared with 50 healthy controls. The fatigue severity scale (FSS), visual analogue scale (VAS) for pain, disability rating index (DRI) and medical outcome study 36-item short-form health status scale (SF-36) were applied. Variables at onset and symptoms at follow-up were correlated with outcome measurements in GBS. RESULTS: VAS [2.9 (SD 3.3) vs. 1.5 (SD 1.9); P = 0.01] and DRI [2.5 (SD 2.1) vs. 1.0 (SD 1.5); P < 0.001] were significantly higher in patients with GBS, compared with healthy controls. Decreased physical functioning and general health were found on SF-36. Differences between GBS patients with shorter (<6 years) and longer (> or =6 years) follow-up after onset were not found. CONCLUSIONS: Relatively independent from various variables at onset, patients with GBS seem to have a reduced quality of life and functioning, and the distress seems to have become persistent after the first few years with improvement following the acute disease.


Asunto(s)
Síndrome de Fatiga Crónica/epidemiología , Síndrome de Guillain-Barré/epidemiología , Estado de Salud , Dolor/epidemiología , Actividades Cotidianas/psicología , Adulto , Anciano , Anciano de 80 o más Años , Enfermedad Crónica/psicología , Evaluación de la Discapacidad , Síndrome de Fatiga Crónica/psicología , Femenino , Síndrome de Guillain-Barré/psicología , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Dolor/psicología , Dimensión del Dolor , Calidad de Vida/psicología , Estrés Psicológico/epidemiología , Encuestas y Cuestionarios , Tiempo
15.
Phys Rev Lett ; 99(13): 130501, 2007 Sep 28.
Artículo en Inglés | MEDLINE | ID: mdl-17930565

RESUMEN

We apply a notion of static renormalization to the preparation of entangled states for quantum computing, exploiting ideas from percolation theory. Such a strategy yields a novel way to cope with the randomness of nondeterministic quantum gates. This is most relevant in the context of optical architectures, where probabilistic gates are common, and cold atoms in optical lattices, where hole defects occur. We demonstrate how to efficiently construct cluster states without the need for rerouting, thereby avoiding a massive amount of conditional dynamics; we furthermore show that except for a single layer of gates during the preparation, all subsequent operations can be shifted to the final adapted single-qubit measurements. Remarkably, cluster state preparation is achieved using essentially the same scaling in resources as if deterministic gates were available.

16.
J Appl Microbiol ; 103(4): 1074-80, 2007 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-17897212

RESUMEN

AIM: To evaluate US Centers for Disease Control and Prevention recommended swab surface sample collection method for recovery efficiency and limit of detection for powdered Bacillus spores from nonporous surfaces. METHODS AND RESULTS: Stainless steel and painted wallboard surface coupons were seeded with dry aerosolized Bacillus atrophaeus spores and surface concentrations determined. The observed mean rayon swab recovery efficiency from stainless steel was 0.41 with a standard deviation (SD) of +/-0.17 and for painted wallboard was 0.41 with an SD of +/-0.23. Evaluation of a sonication extraction method for the rayon swabs produced a mean extraction efficiency of 0.76 with an SD of +/-0.12. Swab recovery quantitative limits of detection were estimated at 25 colony forming units (CFU) per sample area for both stainless steel and painted wallboard. CONCLUSIONS: The swab sample collection method may be appropriate for small area sampling (10 -25 cm2) with a high agent concentration, but has limited value for large surface areas with a low agent concentration. The results of this study provide information necessary for the interpretation of swab environmental sample collection data, that is, positive swab samples are indicative of high surface concentrations and may imply a potential for exposure, whereas negative swab samples do not assure that organisms are absent from the surfaces sampled and may not assure the absence of the potential for exposure. SIGNIFICANCE AND IMPACT OF THE STUDY: It is critical from a public health perspective that the information obtained is accurate and reproducible. The consequence of an inappropriate public health response founded on information gathered using an ineffective or unreliable sample collection method has the potential for undesired social and economic impact.


Asunto(s)
Bacillus/aislamiento & purificación , Celulosa , Manejo de Especímenes/métodos , Esporas Bacterianas/aislamiento & purificación , Recuento de Colonia Microbiana , Materiales de Construcción/microbiología , Monitoreo del Ambiente/métodos , Contaminación de Equipos , Sonicación , Acero Inoxidable , Propiedades de Superficie
17.
Eur J Neurol ; 14(6): 603-8, 2007 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-17539935

RESUMEN

The aim of this study was to evaluate the causes, prevalences, clinical manifestations of hospital-referred polyneuropathies, and evaluate neurophysiological findings in idiopathic polyneuropathy. From 2000 to 2005, 226 patients with polyneuropathy were examined. Polyneuropathy was diagnosed when symptoms, clinical- and neurophysiological findings were compatible with affection of at least two peripheral nerves. They were classified in symptomatic and idiopathic polyneuropathy after investigation. Clinical manifestations were evaluated for diabetes- (DPN), inflammatory- (INPN), hereditary- (HPN) and idiopathic polyneuropathy (IDPN). Neurophysiological findings were investigated in IDPN. 72% had a symptomatic polyneuropathy. Most frequent causes were diabetes mellitus (18%), inflammation, (16%) and hereditary (14%). Most common prevalences per 100,000 were as follows: IDPN, 21; DPN, 13 and HPN, 11. Predominating clinical manifestations were: sensory and motor in INPN, HPN and IPN; sensory in DPN. Pain was more present in IDPN and DPN than in others. In IDPN axonal demyelinating affection was present in 20%. Symptomatic polyneuropathy was common and diabetes mellitus, inflammation and hereditary were frequent causes. In IDPN, DPN, HPN and INPN different clinical patterns were found. Additionally, in IDPN axonal demyelinating affection was more frequent than previously reported.


Asunto(s)
Conducción Nerviosa/fisiología , Nervios Periféricos/fisiopatología , Polineuropatías/epidemiología , Polineuropatías/etiología , Polineuropatías/fisiopatología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Electrodiagnóstico , Femenino , Humanos , Masculino , Persona de Mediana Edad , Noruega/epidemiología , Polineuropatías/clasificación , Prevalencia , Estudios Retrospectivos
18.
Skin Pharmacol Physiol ; 20(1): 57-64, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17035723

RESUMEN

It is often debated that the protection against solar-induced erythema under real conditions is dependent upon the amount of sunscreen applied. It is believed that when too little is applied a lower sun protection than indicated on the label will result. The aim of this study was to quantify this effect. In this multicenter study, the influence of three different amounts (0.5, 1.0, 2.0 mg/cm(2)) of three commercial sunscreen products in three reliable test centers was investigated according to the test protocol of The International Sun Protection Factor Test Method. The main result was a linear dependence of the SPF on the quantity applied. Taking into consideration the volunteer-specific variations, an exponential dependence of confidence interval of the in vivo SPF and amount applied was found. The highest amount applied (2.0 mg/cm(2)) was linked to the lowest confidence intervals. Thus, from the point of view of producing reliable and reproducible in vivo results under laboratory conditions, the recommendation of this multicenter study is an application quantity of 2.0 mg/cm(2).


Asunto(s)
Eritema/prevención & control , Protectores Solares/uso terapéutico , Intervalos de Confianza , Relación Dosis-Respuesta a Droga , Eritema/etiología , Humanos , Modelos Lineales , Protectores Solares/administración & dosificación , Rayos Ultravioleta/efectos adversos
19.
J Chem Phys ; 124(11): 114504, 2006 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-16555898

RESUMEN

High-temperature, high-pressure Raman spectra were obtained from aqueous NaOH solutions up to 2NaOHH2O, with X(NaOH)=0.667 at 480 K. The spectra corresponding to the highest compositions, X(NaOH)> or =0.5, are dominated by H3O2-. An IR xi-function dispersion curve for aqueous NaOH, at 473 K and 1 kbar, calculated from the data of Franck and Charuel indicates that the OH- ion forms H3O2- by preferential H bonding with nonhydrogen-bonded OH groups. Raman spectra from wet to anhydrous, solid LiOH, NaOH, and KOH yield sharp, symmetric OH- stretching peaks at 3664, 3633, and 3596 cm(-1), respectively, plus water-related, i.e., H3O2-, peaks near LiOH, 3562 cm(-1), NaOH, 3596 cm(-1), and, KOH, 3500 cm(-1). Absence of H3O2- peaks from the solid assures that the corresponding melt is anhydrous. Raman spectra from the anhydrous melts yield OH- stretching peak frequencies: LiOH, 3614+/-4 cm(-1), 873 K; NaOH, 3610+/-2 cm(-1), 975 K; and, KOH, 3607+/-2 cm(-1), 773 K, but low-frequency asymmetry due to ion-pair interactions is present which is centered near 3550 cm(-1). The ion-pair-related asymmetry corresponds to the sole IR maximum near 3550 cm(-1) from anhydrous molten NaOH, at 623 K. Bose-Einstein correction of published low-frequency Raman data from molten LiOH revealed an acoustic phonon, near 205 cm(-1), related to restricted translation of OH- versus Li+, and an optical phonon, at 625 cm(-1) and tau approximately 0.05 ps, due to protonic precession and/or pendular motion. Strong H bonding between water and the O atom of OH- forms H3O2-, but the proton of OH- does not bond with H significantly. Large Raman bandwidths (aqueous solutions) are explained in terms of inhomogeneous broadening due to proton transfer in a double well. Vibrational assignments are presented for H3O2-.

20.
Sci Total Environ ; 367(1): 354-66, 2006 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-16434084

RESUMEN

Atmospheric concentrations of elemental mercury (Hg(0)), reactive gaseous Hg (RGM), and particulate Hg (pHg) concentrations were measured in Yellowstone National Park (YNP), U.S.A. using high resolution, real time atmospheric mercury analyzers (Tekran 2537A, 1130, and 1135). A survey of Hg(0) concentrations at various locations within YNP showed that concentrations generally reflect global background concentrations of 1.5-2.0 ng m(-3), but a few specific locations associated with concentrated geothermal activity showed distinctly elevated Hg(0) concentrations (about 9.0 ng m(-3)). At the site of intensive study located centrally in YNP (Canyon Village), Hg(0) concentrations did not exceed 2.5 ng m(-3); concentrations of RGM were generally below detection limits of 0.88 pg m(-3) and never exceeded 5 pg m(-3). Concentrations of pHg ranged from below detection limits to close to 30 pg m(-3). RGM and pHg concentrations were not correlated with any criteria gases (SO(2), NO(x), O(3)); however pHg was weakly correlated with the concentration of atmospheric particles. We investigated three likely sources of Hg at the intensive monitoring site: numerous geothermal features scattered throughout YNP, re-suspended soils, and wildfires near or in YNP. We examined relationships between the chemical properties of aerosols (as measured using real time, single particle mass spectrometry; aerosol time-of-flight mass spectrometer; ATOFMS) and concentrations of atmospheric pHg. Based on the presence of particles with distinct chemical signatures of the wildfires, and the absence of signatures associated with the other sources, we concluded that wildfires in the park were the main source of aerosols and associated pHg to our sampling site.


Asunto(s)
Contaminantes Atmosféricos/análisis , Aire/análisis , Monitoreo del Ambiente , Mercurio/análisis , Aerosoles , Aire/normas , Gases , Tamaño de la Partícula , Estados Unidos
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