Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 74
Filtrar
Más filtros

Base de datos
Tipo del documento
Intervalo de año de publicación
1.
J Hosp Infect ; 134: 7-10, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36696942

RESUMEN

BACKGROUND: The B.1.167.2 (Delta) variant quickly became the predominant circulating SARS-CoV-2 strain in the USA during summer 2021. Missouri identified a high number of outbreaks in long-term care facilities (LTCFs) across the state with low vaccination rates among LTCF staff members and poor adherence to mitigation measures within local communities. AIM: To describe COVID-19 outbreaks that occurred in Missouri LTCFs impacting staff and residents during the surge of the Delta variant. METHODS: Outbreaks of COVID-19 in 178 LTCFs were identified by the Missouri Department of Health and Senior Services. Case data from LTCFs with the highest burden of disease were analysed to assess disease transmission, vaccination status, and outcomes among residents and staff. Additional investigational measures included onsite visits to facilities with recent COVID-19 outbreaks in communities with substantial transmission to assess mitigation measures. FINDINGS: During April 22nd to July 29th, 2021, 159 COVID-19 cases among 72 staff members and 87 residents were identified in 10 LTCFs. More than 74.7% of resident cases were vaccinated compared to 23.6% of staff cases. Vaccinated residents had a lower proportion of hospitalizations and deaths reported compared to unvaccinated residents. Data analysis and contact-tracing efforts from a sample of the facilities suggest that staff members were likely a major factor in introducing SARS-CoV-2 virus into the facilities. Adherence to COVID-19 mitigation measures varied at the visited facilities. CONCLUSION: Data showed that vaccination rates varied between staff cases and resident cases in facilities with high-burden outbreaks. Differences were identified in mitigation practices in at least two facilities.


Asunto(s)
COVID-19 , Humanos , COVID-19/epidemiología , COVID-19/prevención & control , SARS-CoV-2 , Cuidados a Largo Plazo , Brotes de Enfermedades/prevención & control
2.
J Prev Alzheimers Dis ; 9(3): 556-560, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35841257

RESUMEN

Improving the prevention, detection, and treatment of Alzheimer's disease and Alzheimer's disease related dementias (AD/ADRD) across racial, ethnic, and other diverse populations is a national priority. To this end, this paper proposes the development of the Standard Health Record for Dementia (SHRD, pronounced "shared") for collecting and sharing AD/ADRD real-world data (RWD). SHRD would replace the current unstandardized, fragmented, or missing state of key RWD with an open source, consensus-based, and interoperable common data standard. This paper describes how SHRD could leverage the best practices of the Minimal Common Oncology Data Elements (mCODETM) initiative to advance prevention, detection, and treatment; gain adoption by clinicians and electronic health record (EHR) vendors; and establish sustainable business and governance models. It describes a range of potential use cases to advance equity, including strengthening public health surveillance by facilitating AD/ADRD registry reporting; improving case detection and staging; and diversifying participation in clinical trials.


Asunto(s)
Enfermedad de Alzheimer , Equidad en Salud , Enfermedad de Alzheimer/diagnóstico , Enfermedad de Alzheimer/prevención & control , Registros Electrónicos de Salud , Humanos
3.
BMJ Mil Health ; 167(2): 80-83, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32276967

RESUMEN

INTRODUCTION: Humeral shaft fractures can lead to radial nerve injury and may require surgery and rehabilitation. We determined the causative events of humeral fracture, including arm wrestling, in young Korean soldiers and examined whether humeral fracture is related to demographic characteristics and the presence of radial nerve palsy. METHODS: We reviewed 7.5 years (July 2012 to June 2019) of medical records covering patients who had experienced a humeral shaft fracture after entering military service and had received surgery for open reduction and internal fixation. Data were obtained on basic demographics, initial event provoking the fracture, presence of radial nerve palsy, initial and follow-up severity of the weakness, and any discharge from military service because of prolonged radial nerve palsy. RESULTS: Of 123 cases, arm wrestling was the leading cause (52.8%). A high energy injury, such as falling from a height (11.4%), and sports related slips (10.6%) were other causes. All humeral shaft fractures caused by forceful contraction were spiral, while 40% of the fractures caused by external force related events were of a transverse type. The percentage of left-sided fractures was significantly higher for fractures arising from an external force than in those caused by forceful contraction related events. Radial nerve palsy was found in 34 patients (27.6%), and 16 were discharged from the military because of prolonged radial nerve palsy 6 months after the fracture. The causative events and other factors did not affect the presence of radial nerve palsy. CONCLUSION: Arm wrestling was the leading cause of humeral fracture in young Korean soldiers but the chance of developing comorbid radial nerve palsy did not differ from that of other causes. These epidemiologic findings in this young active group may help in understanding the causes of humeral shaft fracture in soldiers and in the wider young population.


Asunto(s)
Húmero/lesiones , Neuropatía Radial/etiología , Lucha/lesiones , Accidentes por Caídas/estadística & datos numéricos , Humanos , Fracturas del Húmero/complicaciones , Fracturas del Húmero/epidemiología , Húmero/fisiopatología , Masculino , Personal Militar/estadística & datos numéricos , Neuropatía Radial/epidemiología , Recuperación de la Función , República de Corea/epidemiología , Adulto Joven
4.
Angew Chem Int Ed Engl ; 59(31): 12860-12867, 2020 Jul 27.
Artículo en Inglés | MEDLINE | ID: mdl-32379944

RESUMEN

Simultaneously improving energy efficiency (EE) and material stability in electrochemical CO2 conversion remains an unsolved challenge. Among a series of ternary Sn-Ti-O electrocatalysts, 3D ordered mesoporous (3DOM) Sn0.3 Ti0.7 O2 achieves a trade-off between active-site exposure and structural stability, demonstrating up to 71.5 % half-cell EE over 200 hours, and a 94.5 % Faradaic efficiency for CO at an overpotential as low as 430 mV. DFT and X-ray absorption fine structure analyses reveal an electron density reconfiguration in the Sn-Ti-O system. A downshift of the orbital band center of Sn and a charge depletion of Ti collectively facilitate the dissociative adsorption of the desired intermediate COOH* for CO formation. It is also beneficial in maintaining a local alkaline environment to suppress H2 and formate formation, and in stabilizing oxygen atoms to prolong durability. These findings provide a new strategy in materials design for efficient CO2 conversion and beyond.

5.
Micromachines (Basel) ; 10(4)2019 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-31018608

RESUMEN

In recent times, the haptic actuators have been providing users with tactile feedback via vibration for a realistic experience. The vibration spring must be designed thin and small to use a haptic actuator in a smart device. Therefore, considerable interests have been exhibited with respect to the impact characteristics of these springs. However, these springs have been difficult to analyze due to their small size. In this study, drop impact experiments and analyses were performed to examine the damages of the mechanical spring in a miniature haptic actuator. Finally, an analytical model with high strain rate and damping effects was constructed to analyze the impact characteristics.

7.
J Comp Pathol ; 155(1): 62-71, 2016 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-27338785

RESUMEN

The time of onset and subsequent degree and progression of clinical signs, bacterial colonization and tissue pathology during experimental disease induced by intratracheal inoculation of either a UK or USA isolate of Pasteurella multocida serotype A recovered from clinical cases of bovine pneumonia were determined. Calves aged 8 weeks were challenged with 300 ml phosphate buffered saline (PBS) alone (group 1, n = 3, negative control) or containing 7.1 × 10(8) colony forming units (cfu) of UK isolate (group 2, n = 8) or 5.8 × 10(8) cfu of USA isolate (group 3, n = 8). Bronchoalveolar lavage (BAL) at 0, 1 and 4 days post challenge (dpc) and at the time of necropsy examination (7-8 dpc) showed no significant differences between groups 2 and 3 in bacterial numbers recovered. No P. multocida were recovered from group 1 animals. No clinical disease was present in group 1 calves and in group 3 was limited to scour in 1 calf at 1 dpc. All calves in group 2 had reduced food intake at 4-5 dpc, five had periods of dullness, three a mild nasal discharge at 1 dpc, four had mild to substantial respiratory stridor and one was killed at 6 dpc for humane reasons. Rectal temperatures remained about 39°C in group 1 calves, but increased in P. multocida-challenged calves to 40-41°C within 8-12 h of challenge. Significantly (P = 0.01) greater percentages of lung surface area were consolidated in group 2 (mean ± SD, 21 ± 10.1) compared with group 3 (7 ± 8.6) calves. Significantly more extensive and severe histological lesions were present in the lung lobes (P = 0.006) and lymph nodes (P = 0.02) of group 2 compared with group 3 calves. Pleurisy was present in group 2 calves only and no pathology was present in group 1. Pulsed-field gel electrophoresis (PFGE) produced 11 (group 2, UK isolate) or 10 (group 3, USA isolate) bands with differences in banding patterns. Results overall showed that two isolates, distinct geographically and genetically (by PFGE), caused pneumonic pasteurellosis in a single host with significantly different severity of pathology. This information is relevant to the development of novel vaccine control and interpretation of diagnostic results.


Asunto(s)
Pasteurella multocida/genética , Pasteurella multocida/patogenicidad , Pasteurelosis Neumónica/genética , Pasteurelosis Neumónica/virología , Animales , Bovinos , Pasteurelosis Neumónica/patología , Reino Unido , Estados Unidos , Virulencia
8.
J Biomater Appl ; 30(5): 558-67, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26184354

RESUMEN

Recently, we have shown that anti-BMP2 monoclonal antibodies (mAbs) can trap endogenous osteogenic BMP ligands, which can in turn mediate osteodifferentiation of progenitor cells. The effectiveness of this strategy requires the availability of the anti-BMP-2 monoclonal antibodies antigen-binding sites for anti-BMP-2 monoclonal antibodies to bind to the scaffold through a domain that will leave its antigen-binding region exposed and available for binding to an osteogenic ligand. We examined whether antibodies bound to a scaffold by passive adsorption versus through Protein G as a linker will exhibit differences in mediating bone formation. In vitro anti-BMP-2 monoclonal antibodies was immobilized on absorbable collagen sponge (ACS) with Protein G as a linker to bind the antibody through its Fc region and implanted into rat calvarial defects. The biomechanical strength of bone regenerated by absorbable collagen sponge/Protein G/anti-BMP-2 monoclonal antibodies immune complex was compared to ACS/anti-BMP-2 monoclonal antibodies or ACS/Protein G/isotype mAb control group. Results demonstrated higher binding of anti-BMP-2 monoclonal antibodies/BMPs to C2C12 cells, when the mAb was initially attached to recombinant Protein G or Protein G-coupled microbeads. After eight weeks, micro-CT and histomorphometric analyses revealed increased bone formation within defects implanted with absorbable collagen sponge/Protein G/anti-BMP-2 monoclonal antibodies compared with defects implanted with absorbable collagen sponge/anti-BMP-2 monoclonal antibodies (p < 0.05). Confocal laser scanning microscopy (CLSM) confirmed increased BMP-2, -4, and -7 detection in sites implanted with absorbable collagen sponge/Protein G/anti-BMP-2 monoclonal antibodies in vivo. Biomechanical analysis revealed the regenerated bone in sites with Protein G/anti-BMP-2 monoclonal antibodies had higher mechanical strength in comparison to anti-BMP-2 monoclonal antibodies. The negative control group, Protein G/isotype mAb, did not promote bone regeneration and exhibited significantly lower mechanical properties (p < 0.05). Altogether, our results demonstrated that application of Protein G as a linker to adsorb anti-BMP-2 monoclonal antibodies onto the scaffold was accompanied by increased in vitro binding of the anti-BMP-2 mAb/BMP immune complex to BMP-receptor positive cell, as well as increased volume and strength of de novo bone formation in vivo.


Asunto(s)
Implantes Absorbibles , Anticuerpos Inmovilizados/uso terapéutico , Anticuerpos Monoclonales/uso terapéutico , Proteína Morfogenética Ósea 2/inmunología , Regeneración Ósea/efectos de los fármacos , Cráneo/efectos de los fármacos , Cráneo/fisiología , Animales , Anticuerpos Inmovilizados/administración & dosificación , Anticuerpos Inmovilizados/inmunología , Anticuerpos Monoclonales/administración & dosificación , Anticuerpos Monoclonales/inmunología , Línea Celular , Colágeno/química , Femenino , Ratones , Ratas Sprague-Dawley , Cráneo/inmunología , Cráneo/lesiones
9.
Rev Sci Instrum ; 86(4): 045104, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25933894

RESUMEN

If a vibration module is added on laser machining system, the quality of surface finish and aspect ratio on metals can be significantly enhanced. In this study, a single mobility model of vibrating laser along the path of laser beam was put forward. In order to realize the desired unidirectional motion, a resonance type vibration module with optical lens was designed and manufactured. This cylindrical module was composed of curved-beam flexure elements. The cylindrical coordinate system was established to describe the relationship of a curved-beam flexure element's motion and deformation. In addition, the stiffness matrix of the curved-beam element was obtained. Finite element method and dynamical modeling were provided to analyze the resonance frequency and the displacement of the motion. The feasibility of the design was demonstrated with the help of experiments on frequency response. Experimental results show good agreement with theoretical analysis and simulation predictions.

10.
Rev Sci Instrum ; 85(4): 045104, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24784656

RESUMEN

Laser scanning systems have been used for material processing tasks such as welding, cutting, marking, and drilling. However, applications have been limited by the small range of motion and slow speed of the focusing unit, which carries the focusing optics. To overcome these limitations, a dynamic focusing system with a long travel range and high speed is needed. In this study, a dynamic focusing unit for a laser scanning system with a voice coil motor (VCM) mechanism is proposed to enable fast speed and a wide focusing range. The VCM has finer precision and higher speed than conventional step motors and a longer travel range than earlier lead zirconium titanate actuators. The system has a hollow configuration to provide a laser beam path. This also makes it compact and transmission-free and gives it low inertia. The VCM's magnetics are modeled using a permeance model. Its design parameters are determined by optimization using the Broyden-Fletcher-Goldfarb-Shanno method and a sequential quadratic programming algorithm. After the VCM is designed, the dynamic focusing unit is fabricated and assembled. The permeance model is verified by a magnetic finite element method simulation tool, Maxwell 2D and 3D, and by measurement data from a gauss meter. The performance is verified experimentally. The results show a resolution of 0.2 µm and travel range of 16 mm. These are better than those of conventional focusing systems; therefore, this focusing unit can be applied to laser scanning systems for good machining capability.

11.
Res Vet Sci ; 94(3): 634-40, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23415879

RESUMEN

The gram-negative bacterium Pasteurella multocida causes pneumonic and systemic pasteurellosis in bovids for which vaccines are either unavailable or inadequate. The work assessed whether an intranasal P. multocida challenge in mice might provide a model of infection for future vaccine development work. Clinical, pathological and biochemical responses were compared in seven strains of mice challenged with a virulent bovine pneumonic isolate of P. multocida A:3. Six mouse strains (Porton, CD-1, BALB/c, VM, C57BL/10 and C57BL/6) developed clinical signs of pneumonic disease and variable pneumonic lesions 41-70 h post-infection. In contrast, mouse strain RIII became septicaemic within 36 h post-infection. Concentrations of plasma acute phase proteins and serum lipopolysaccharide increased in all mice after infection, and the main or interaction effect of mouse strain and infection status was statistically significant (P<0.05). Responses in C57BL/10 mice showed close similarity to bovine pneumonic and in RIII mice to bovine systemic pasteurellosis.


Asunto(s)
Ratones Endogámicos/microbiología , Infecciones por Pasteurella/veterinaria , Pasteurella multocida/patogenicidad , Proteínas de Fase Aguda/análisis , Animales , Bovinos , Enfermedades de los Bovinos/microbiología , Modelos Animales de Enfermedad , Femenino , Lipopolisacáridos/sangre , Ratones , Ratones Endogámicos BALB C/microbiología , Ratones Endogámicos C57BL/microbiología , Infecciones por Pasteurella/microbiología , Infecciones por Pasteurella/patología , Neumonía Bacteriana/microbiología , Neumonía Bacteriana/patología , Neumonía Bacteriana/veterinaria
12.
Anal Chem ; 85(4): 2246-52, 2013 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-23331177

RESUMEN

Here, we report development of the galvanostatic Fourier transform electrochemical impedance spectroscopy (FTEIS), which monitors impedance of electrochemical reactions activated by current steps. We first derive relevant relations for potential change upon application of a step current, obtain impedances theoretically from the relations by simulation, and verify them with experimental results. The validity of the galvanostatic FTEIS technique is demonstrated by measuring impedances of a semiconductive silicon wafer using the conventional frequency response analysis (FRA), the potentiostatic FTEIS, and the galvanostatic FTEIS methods, and the results are in excellent agreement with each other. This work is significant in that the galvanostatic FTEIS would allow one to record impedance changes during charge/discharge cycles of secondary batteries and fuel cells as well as electrochemically irreversible systems which may produce noise level chronoamperometric currents by potentiostatic techniques.

13.
Rev Sci Instrum ; 82(2): 026102, 2011 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21361641

RESUMEN

This paper presents the design, fabrication, and experimental results of a novel ultraprecision in-plane XYθ positioning stage with kinematic decoupling between translational motion and rotational motion components. Two translational motions are guided by four cymbal mechanisms that have both motion guide and motion amplifier. Four leaf springs guide a rotational motion amplified by a Scott-Russell linkage mechanism. The proposed stage has advantages such as an in-plane symmetrical configuration as well as ease of design and control by serial kinematics. The experimental results demonstrate that the stage has a translational full motion range of 58 µm and a rotational full motion range of 1.05 mrad. The crosstalk experimental results show good agreement with the theoretical prediction of the decoupling between translational motion and rotational motion.

14.
Eur J Neurol ; 18(9): 1151-8, 2011 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-21299736

RESUMEN

BACKGROUND AND PURPOSE: Extensive evidence has shown that oxidative stress mediates neuronal death in animal models of hypoxic-ischaemia. Brain biomarkers of oxidative stress need to be identified in order to better understand and treat brain damage in human stroke patients. The present study was conducted to identify potential target proteins of oxidative stress in the cerebrospinal fluid (CSF) of stroke patients with acute ischaemic brain injury. METHODS: We performed two-dimensional polyacrylamide gel electrophoresis to separate protein samples obtained from the CSF of control and stroke patients. To determine protein oxidation levels, oxyblot was then used to detect protein carbonyls that were determined by formation of a stable 2,4-dinitrophenylhydrazine (DNP) product using an anti-DNP antibody. RESULTS: We found that oxidation of serum albumin was increased in the CSF from stroke patients as well as rats who underwent permanent middle cerebral artery occlusion (6.5%, 23%, respectively). In stroke patients, oxidized albumin levels correlated to neurologic indications. CONCLUSIONS: The present study suggests that oxidized albumin in CSF can be utilized as an oxidative stress marker in human stroke patients.


Asunto(s)
Biomarcadores/líquido cefalorraquídeo , Estrés Oxidativo/fisiología , Albúmina Sérica/líquido cefalorraquídeo , Accidente Cerebrovascular/líquido cefalorraquídeo , Animales , Western Blotting , Electroforesis en Gel Bidimensional , Femenino , Humanos , Masculino , Persona de Mediana Edad , Ratas , Ratas Sprague-Dawley
15.
Tob Control ; 18(5): 371-6, 2009 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-19556614

RESUMEN

OBJECTIVE: To identify the impact of a smoking cessation programme on area-based social and ethnic inequalities in smoking rates through social and ethnic differences in enrolment and quitting. METHODS: Analysis of records of 11 325 patients who enrolled in an innovative smoking cessation programme in Christchurch, New Zealand between 2001 and 2006. We compare enrolment, follow-up, quitting and impact on population smoking rates in the most and least deprived neighbourhoods and the neighbourhoods with the lowest and highest proportions of Maori. RESULTS: Enrolment as a proportion of the population was higher from the most deprived areas but as a proportion of neighbourhood smokers, it was lower. Enrolees from the least deprived quintile were 40% more likely to quit than those from the most deprived quintile. Smoking rates were 2.84 (2.75 to 2.93) times higher in the most deprived neighbourhoods. If the programme had not been available we estimate that this differential would have reduced to 2.81 (2.72 to 2.90). In neighbourhoods with the highest proportion of Maori, smoking rates were 2.33 (2.26 to 2.41) times higher and we estimate that without the programme smoking rates would be 2.30 (2.23 to 2.37) times higher. CONCLUSIONS: Although enrolees were drawn from a wide variety of backgrounds, those most likely to quit tended to reside in affluent areas or areas with a low proportion of Maori. There was no evidence that this smoking cessation programme increased or decreased inequalities within the Christchurch population. For smoking cessation programmes to have an impact on health inequalities more effort is required in targeting hard-to-reach groups and in encouraging them to quit.


Asunto(s)
Educación en Salud/métodos , Disparidades en el Estado de Salud , Cese del Hábito de Fumar/etnología , Fumar/etnología , Humanos , Nativos de Hawái y Otras Islas del Pacífico/estadística & datos numéricos , Nueva Zelanda/epidemiología , Áreas de Pobreza , Evaluación de Programas y Proyectos de Salud , Cese del Hábito de Fumar/métodos , Prevención del Hábito de Fumar
16.
Rev Sci Instrum ; 80(4): 045106, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19405690

RESUMEN

Next-generation lithography requires a high precision stage, which is compatible with a high vacuum condition. A magnetic levitation stage with six degrees-of-freedom is considered state-of-the-art technology for a high vacuum condition. The noncontact characteristic of magnetic levitation enables high precision positioning as well as no particle generation. To position the stage against gravity, z-directional electromagnetic levitation mechanisms are widely used. However, if electromagnetic actuators for levitation are used, heat is inevitably generated, which deforms the structures and degrades accuracy of the stage. Thus, a gravity compensator is required. In this paper, we propose a new magnetic bearing using Halbach magnet arrays for a magnetic levitation stage. The novel Halbach magnetic bearing exerts a force four times larger than a conventional magnetic bearing with the same volume. We also discuss the complementary characteristics of the two magnetic bearings. By modifying the height of the center magnet in a Halbach magnetic bearing, a performance compromise between levitating force density and force uniformity is obtained. The Halbach linear active magnetic bearing can be a good solution for magnetic levitation stages because of its large and uniform levitation force.

17.
J Epidemiol Community Health ; 63(1): 69-77, 2009 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-18628269

RESUMEN

OBJECTIVE: To investigate whether neighbourhood measures of geographical accessibility to outlets selling tobacco (supermarkets, convenience stores and petrol stations) are associated with individual smoking behaviour in New Zealand. METHODS: Using geographical information systems, travel times from the population-weighted centroid of each neighbourhood to the closest outlet selling tobacco were calculated for all 38,350 neighbourhoods across New Zealand. These measures were appended to the 2002/03 New Zealand Health Survey, a national survey of 12, 529 adults. Two-level logistic regression models were fitted to examine the effects of neighbourhood locational access upon individual smoking behaviour after controlling for potential individual- and neighbourhood-level confounding factors, including deprivation and urban/rural status. RESULTS: After controlling for individual-level demographic and socioeconomic variables, individuals living in the quartiles of neighbourhoods with the best access to supermarkets (OR 1.23, 95% CI 1.06 to 1.42) and convenience stores (OR 1.19, 95% CI 1.03 to 1.38) had a higher odds of smoking compared with individuals in the worst access quartiles. However, the association between neighbourhood accessibility to supermarkets and convenience stores was not apparent once other neighbourhood-level variables (deprivation and rurality) were included. CONCLUSIONS: At the national level, there is little evidence to suggest that, after adjustment for neighbourhood deprivation, better locational access to tobacco retail provision in New Zealand is associated with individual-level smoking behaviour.


Asunto(s)
Comercio , Nicotiana , Características de la Residencia , Fumar/epidemiología , Adolescente , Adulto , Anciano , Comercio/estadística & datos numéricos , Femenino , Conductas Relacionadas con la Salud , Humanos , Masculino , Persona de Mediana Edad , Nueva Zelanda/epidemiología , Medio Social , Adulto Joven
18.
Rev Sci Instrum ; 79(2 Pt 1): 026110, 2008 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-18315342

RESUMEN

In this article, a linear piezoelectric stepping positioner developed by Kang et al. [Rev. Sci. Instrum. 78, 075112 (2007)] is extended to have a two degree of freedom XY linear motion and it is experimentally evaluated. A resolution less than 10 nm, a speed of over 0.5 mm/s, push forces of 17.9 and 19.5, and stiffnesses of 6.54 and 5.90 N/microm are attained while maintaining a compact size of 96x96x39 mm3 and the required power consumption of 102.74 W.

19.
Rev Sci Instrum ; 78(7): 075112, 2007 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-17672798

RESUMEN

Many application areas such as semiconductor manufacture, precision optics alignment, and microbiological cell manipulation require ultraprecision positioning systems with a high positioning resolution and large motion range. This article describes the development of a compact high precision linear piezoelectric stepping positioner for precision alignment of optical elements. The positioner is designed to have a compact and symmetric structure, high positioning resolution, large motion range, high force density, adequate dynamic range, and power-off hold. The positioner is fabricated according to these specifications and performance evaluation tests are carried out. A resolution of 10 nm, speed of 1 mms, push force of 25 N, and stiffness of 10.4 N/microm are attained while maintaining a compact size of 32x42x60 mm(3). The required power consumption is 52.33 W. The test results confirm that the developed positioner could be successfully applied to the precision alignment of optical elements.


Asunto(s)
Acústica/instrumentación , Micromanipulación/instrumentación , Nanotecnología/instrumentación , Manejo de Especímenes/instrumentación , Diseño de Equipo , Análisis de Falla de Equipo , Micromanipulación/métodos , Miniaturización , Movimiento (Física) , Nanotecnología/métodos , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Manejo de Especímenes/métodos
20.
J Gastroenterol Hepatol ; 21(6): 1026-35, 2006 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-16724990

RESUMEN

BACKGROUND AND AIM: Hepatic arterial infusion (HAI) chemotherapy has a number of limitations, including a low rate of complete response and frequent extrahepatic recurrence, in colorectal cancer patients with non-resectable hepatic metastases. METHODS: Twenty-nine colorectal cancer patients with non-resectable hepatic metastases were consecutively enrolled for HAI alternating with systemic chemotherapy (HA + SC group). The protocol comprised six cycles of alternating HAI (5-FU + leucovorin for 14 days, and mitomycin C on the first day) and systemic chemotherapy (5-FU + leucovorin). Colorectal cancer patients with two or more hepatic metastases treated using hepatic resection and systemic chemotherapy (HR + SC group) were selected as a comparative group. RESULTS: Within the HA + SC group, complete response was achieved in eight patients (28%), whereas 13 patients (45%) showed progressive disease. Six of the eight patients with complete response lived for more than 38 months. Extrahepatic recurrences were more frequent in the HR + SC group than the HA + SC group (47 vs 21%, P = 0.024). The two groups did not differ with respect to overall and hepatic progression-free survival (P = 0.947 and 0.444, respectively), displaying median +/- SE values of 38 +/- 7 and 20 +/- 3 months in the HA + SC group, and 39 +/- 9 and 33 +/- 14 months in the HR + SC group, respectively. One patient in each group experienced toxic hepatitis, and sclerosing cholangitis occurred in one patient of the HA + SC group. Other complications were mostly grade 1 or 2. CONCLUSIONS: HAI alternating with systemic chemotherapy led to a promising response and hepatic progression-free survival, possibly reducing extrahepatic recurrence in colorectal cancer patients with non-resectable liver metastases.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica , Neoplasias Colorrectales/tratamiento farmacológico , Arteria Hepática , Neoplasias Hepáticas/tratamiento farmacológico , Anciano , Neoplasias Colorrectales/mortalidad , Neoplasias Colorrectales/patología , Femenino , Fluorouracilo/administración & dosificación , Humanos , Infusiones Intraarteriales , Leucovorina/administración & dosificación , Neoplasias Hepáticas/mortalidad , Neoplasias Hepáticas/secundario , Masculino , Persona de Mediana Edad , Mitomicina/administración & dosificación , Recurrencia Local de Neoplasia/diagnóstico , Resultado del Tratamiento
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA