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1.
JAMA Netw Open ; 3(9): e209750, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32997124

RESUMO

Importance: The association of guideline-based decision support with the quality of care in patients with non-small cell lung cancer (NSCLC) is not known. Objective: To evaluate the association of exposure to the National Comprehensive Cancer Center (NCCN) guidelines with guideline-concordant care and patients' decisional conflict. Design, Setting, and Participants: A nonrandomized clinical trial, conducted at a tertiary care academic institution, enrolled patients from February 23, 2015, to September 28, 2017. Data analysis was conducted from July 19, 2019, to April 22, 2020. A cohort of 76 patients with NSCLC seen at diagnosis or disease progression and a retrospective cohort of 157 patients treated before the trial were included. Adherence to 6 NCCN recommendations were evaluated: (1) smoking cessation counseling, (2) adjuvant chemotherapy for patients with stage IB to IIB NSCLC after surgery, (3) pathologic mediastinal staging in patients with stage III NSCLC before surgery, (4) pathologic mediastinal staging in patients with stage III NSCLC before nonsurgical treatment, (5) definitive chemoradiotherapy for patients with stage III NSCLC not having surgery, and (6) molecular testing for epidermal growth factor receptor and anaplastic lymphoma kinase alterations for patients with stage IV NSCLC. Subgroup analysis was conducted to compare the rates of guideline concordance between the prospective and retrospective cohorts. Secondary end points included decisional conflict and satisfaction. Interventions: An online tool customizing the NCCN guidelines to patients' clinical and pathologic features was used during consultation, facilitated by a trained coordinator. Main Outcomes and Measures: Concordance of practice with 6 NCCN treatment recommendations on NSCLC and patients' decisional conflict. Results: Of the 76 patients with NSCLC, 44 were men (57.9%), median age at diagnosis was 68 years (interquartile range [IQR], 41-87 years), and 59 patients (77.6%) had adenocarcinoma. In the retrospective cohort, 91 of 157 patients (58.0%) were men, median age at diagnosis was 66 years (IQR, 61-65 years), and 105 patients (66.9%) had adenocarcinoma. After the intervention, patients received more smoking cessation counseling (4 of 5 [80.0%] vs 1 of 24 [4.2%], P < .001) and less adjuvant chemotherapy (0 of 7 vs 7 of 11 [63.6%]; P = .012). There was no significant change in mutation testing of non-squamous cell stage IV disease (20 of 20 [100%] vs 48 of 57 [84.2%]; P = .10). There was no significant change in pathologic mediastinal staging or initial chemoradiotherapy for patients with stage III disease. After consultation with the tool, decisional conflict scores improved by a median of 20 points (IQR, 3-34; P < .001). Conclusions and Relevance: The findings of this study suggest that exposure to the NCCN guidelines is associated with increased guideline-concordant care for 2 of 6 preselected recommendations and improvement in decisional conflict. Trial Registration: ClinicalTrials.gov Identifier: NCT03982459.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Sistemas de Apoio a Decisões Clínicas , Neoplasias Pulmonares , Qualidade de Vida , Adenocarcinoma de Pulmão/patologia , Adenocarcinoma de Pulmão/psicologia , Adenocarcinoma de Pulmão/terapia , Idoso , Carcinoma Pulmonar de Células não Pequenas/patologia , Carcinoma Pulmonar de Células não Pequenas/psicologia , Carcinoma Pulmonar de Células não Pequenas/terapia , Assistência Integral à Saúde/métodos , Assistência Integral à Saúde/normas , Técnicas de Apoio para a Decisão , Feminino , Humanos , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/psicologia , Neoplasias Pulmonares/terapia , Masculino , Estadiamento de Neoplasias/métodos , Satisfação do Paciente , Guias de Prática Clínica como Assunto , Prognóstico , Qualidade da Assistência à Saúde/normas , Avaliação de Sintomas/métodos
2.
J Appl Crystallogr ; 50(Pt 2): 462-474, 2017 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-28381972

RESUMO

The certification of a new standard reference material for small-angle scattering [NIST Standard Reference Material (SRM) 3600: Absolute Intensity Calibration Standard for Small-Angle X-ray Scattering (SAXS)], based on glassy carbon, is presented. Creation of this SRM relies on the intrinsic primary calibration capabilities of the ultra-small-angle X-ray scattering technique. This article describes how the intensity calibration has been achieved and validated in the certified Q range, Q = 0.008-0.25 Å-1, together with the purpose, use and availability of the SRM. The intensity calibration afforded by this robust and stable SRM should be applicable universally to all SAXS instruments that employ a transmission measurement geometry, working with a wide range of X-ray energies or wavelengths. The validation of the SRM SAXS intensity calibration using small-angle neutron scattering (SANS) is discussed, together with the prospects for including SANS in a future renewal certification.

3.
J Res Natl Inst Stand Technol ; 121: 476-497, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-34434636

RESUMO

A new material has been certified to become Standard Reference Material (SRM) 2806b - Medium Test Dust in Hydraulic Fluid. SRM 2806b consists of trace polydisperse, irregularly shaped mineral dust particles suspended in hydraulic fluid. The certified values of SRM 2806b are the projected area circular-equivalent diameters of the collected dust particles from the hydraulic fluid. The dimensional measurements were determined from the area of the collected dust particles using images obtained from automated scanning electron microscopy (SEM) followed by image analysis. An automated SEM and an automated image analysis software allowed the processing of over 29 million particles. The dimensional calibration of the SEM images (actual length per pixel and thus the actual projected diameters) are traceable to the NIST Line Scale Interferometer (LSI) through a NIST calibrated Geller MRS-4XY pitch standard. The certified diameters are correlated with the numeric concentration of particles greater than each diameter, referred to as the cumulative number size distribution. SRM 2806b is intended to be used to calibrate liquid-borne optical particle counters in conjunction with the reference method ISO 11171:2010.

4.
J Res Natl Inst Stand Technol ; 120: 164-72, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26958445

RESUMO

The devices calibrated most frequently by the acoustical measurement services at the National Institute of Standards and Technology (NIST) over the 50-year period from 1963 to 2012 were one-inch condenser microphones of three specific standard types: LS1Pn, LS1Po, and WS1P. Due to its long history of providing calibrations of such microphones to customers, NIST is in a unique position to analyze data concerning the long-term stability of these devices. This long history has enabled NIST to acquire and aggregate a substantial amount of repeat calibration data for a large number of microphones that belong to various other standards and calibration laboratories. In addition to determining microphone sensitivities at the time of calibration, it is important to have confidence that the microphones do not typically undergo significant drift as compared to the calibration uncertainty during the periods between calibrations. For each of the three microphone types, an average drift rate and approximate 95 % confidence interval were computed by two different statistical methods, and the results from the two methods were found to differ insignificantly in each case. These results apply to typical microphones of these types that are used in a suitable environment and handled with care. The average drift rate for Type LS1Pn microphones was -0.004 dB/year to 0.003 dB/year. The average drift rate for Type LS1Po microphones was -0.016 dB/year to 0.008 dB/year. The average drift rate for Type WS1P microphones was -0.004 dB/year to 0.018 dB/year. For each of these microphone types, the average drift rate is not significantly different from zero. This result is consistent with the performance expected of condenser microphones designed for use as transfer standards. In addition, the values that bound the confidence intervals are well within the limits specified for long-term stability in international standards. Even though these results show very good long-term stability historically for these microphone types, it is expected that periodic calibrations will always be done to track the calibration history of individual microphones and check for anomalies indicative of shifts in sensitivity.

5.
NCSL Int Meas ; 10(1): 28-31, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-27525049

RESUMO

In recent years there has been considerable interest in developing photonic temperature sensors such as the Fiber Bragg gratings (FBG) as an alternative to resistance thermometry. In this study we examine the thermal response of FBGs over the temperature range of 233 K to 393 K. We demonstrate, in hermetically sealed dry Argon environment, FBG devices show a quadratic dependence on temperature with expanded uncertainties (k=2) of ≈500 mK. Our measurements indicate that the combined measurement uncertainty is dominated by uncertainty in determining peak center fitting and thermal ageing of polyimide coated fibers.

6.
J Radioanal Nucl Chem ; 299(3): 1555-1563, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26300575

RESUMO

A newly developed procedure for determination of arsenic by radiochemical neutron activation analysis (RNAA) was used to measure arsenic at four levels in SRM 955c Toxic Elements in Caprine Blood and at two levels in SRM 2668 Toxic Elements in Frozen Human Urine for the purpose of providing mass concentration values for certification. Samples were freeze-dried prior to analysis followed by neutron irradiation for 3 h at a fluence rate of 1×1014cm-2s-1. After sample dissolution in perchloric and nitric acids, arsenic was separated from the matrix by extraction into zinc diethyldithiocarbamate in chloroform, and 76As quantified by gamma-ray spectroscopy. Differences in chemical yield and counting geometry between samples and standards were monitored by measuring the count rate of a 77As tracer added before sample dissolution. RNAA results were combined with inductively coupled plasma - mass spectrometry (ICP-MS) values from NIST and collaborating laboratories to provide certified values of (10.81 ± 0.54) µg/kg and (213.1 ± 0.73) µg/kg for SRM 2668 Levels I and II, and certified values of (21.66 ± 0.73) µg/kg, (52.7 ± 1.1) µg/kg, and (78.8 ± 4.9) µg/kg for SRM 955c Levels 2, 3, and 4 respectively. Because of discrepancies between values obtained by different methods for SRM 955c Level 1, an information value of < 5 µg/kg was assigned for this material.

7.
Anal Chem ; 85(24): 11732-8, 2013 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-24187941

RESUMO

The National Institute of Standards and Technology (NIST), in collaboration with the National Institutes of Health (NIH), has developed a Standard Reference Material (SRM) to support technology development in metabolomics research. SRM 1950 Metabolites in Human Plasma is intended to have metabolite concentrations that are representative of those found in adult human plasma. The plasma used in the preparation of SRM 1950 was collected from both male and female donors, and donor ethnicity targets were selected based upon the ethnic makeup of the U.S. population. Metabolomics research is diverse in terms of both instrumentation and scientific goals. This SRM was designed to apply broadly to the field, not toward specific applications. Therefore, concentrations of approximately 100 analytes, including amino acids, fatty acids, trace elements, vitamins, hormones, selenoproteins, clinical markers, and perfluorinated compounds (PFCs), were determined. Value assignment measurements were performed by NIST and the Centers for Disease Control and Prevention (CDC). SRM 1950 is the first reference material developed specifically for metabolomics research.


Assuntos
Análise Química do Sangue/normas , Metabolômica/normas , Adulto , Aminoácidos/sangue , Biomarcadores/sangue , Carotenoides/sangue , Ácidos Graxos/sangue , Feminino , Humanos , Masculino , National Institutes of Health (U.S.) , Padrões de Referência , Estados Unidos , Vitaminas/sangue
8.
J Res Natl Inst Stand Technol ; 118: 260-79, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-26401432

RESUMO

Programmers routinely omit run-time safety checks from applications because they assume that these safety checks would degrade performance. The simplest example is the use of arrays or array-like data structures that do not enforce the constraint that indices must be within bounds. This report documents an attempt to measure the performance penalty incurred by two different implementations of bounds-checking in C and C++ using a simple benchmark and a desktop PC with a modern superscalar CPU. The benchmark consisted of a loop that wrote to array elements in sequential order. With this configuration, relative to the best performance observed for any access method in C or C++, mean degradation of only (0.881 ± 0.009) % was measured for a standard bounds-checking access method in C++. This case study showed the need for further work to develop and refine measurement methods and to perform more comparisons of this type. Comparisons across different use cases, configurations, programming languages, and environments are needed to determine under what circumstances (if any) the performance advantage of unchecked access is actually sufficient to outweigh the negative consequences for security and software quality.

10.
Anal Chem ; 80(16): 6154-8, 2008 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-18630929

RESUMO

A mathematical formulation for a gravimetric approach to the univariate standard addition method (SAM) is presented that has general applicability for both liquids and solids. Using gravimetry rather than volumetry reduces the preparation time, increases design flexibility, and makes increased accuracy possible. SAM has most often been used with analytes in aqueous solutions that are aspirated into flames or plasmas and determined by absorption, emission, or mass spectrometric techniques. The formulation presented here shows that the method can also be applied to complex matrixes, such as distillate and residual fuel oils, using techniques such as X-ray fluorescence (XRF) or combustion combined with atomic fluorescence or absorption. These techniques, which can be subject to matrix-induced interferences, could realize the same benefits that have been demonstrated for dilute aqueous solutions.

11.
J Am Dent Assoc ; 137(8): 1131-8, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16873330

RESUMO

BACKGROUND: Calcium phosphate cement (CPC) hardens in situ to form hydroxyapatite and has been used in dental and craniofacial restorative applications. However, when CPC was used in periodontal osseous repair, tooth mobility resulted in the fracture and exfoliation of the brittle CPC implant. The objective of the authors' study was to develop a strong and nonrigid CPC to provide compliance for tooth mobility without fracturing the implant. METHODS: The authors used tetracalcium phosphate, dicalcium phosphate anhydrous and biopolymer chitosan to develop a strong and nonrigid CPC. They used a powder:liquid ratio of 2:1, compared with the 1:1 ratio of a previously developed nonrigid CPC control. Specimens were characterized using a flexural test, scanning electron microscopy and powder X-ray diffraction. RESULTS: After 28 days of immersion, the new cement had a flexural strength (mean +/- standard deviation; n = 6) of 5.2 +/- 1.0 megapascals, higher than 1.8 +/- 1.5 MPa for the control (P < .05) and overlapping the reported strengths of sintered hydroxyapatite implants and cancellous bone. This cement showed a high ductility with a strain at peak load of 6.5 +/- 1.3 percent, compared with 4.4 +/- 1.9 percent for the control; both were 20-fold higher than the 0.2 percent of the conventional CPC. Nanosized hydroxyapatite crystals, similar to those in teeth and bones, were formed in the cements. CONCLUSIONS: The new nonrigid cement, containing nanohydroxyapatite crystals, possessed a high ductility and superior fracture resistance. This strong, tough and nonrigid CPC may be useful in periodontal repair to provide compliance for tooth mobility without fracture. CLINICAL IMPLICATIONS: The results of this study may yield the first self-hardening and nonrigid hydroxyapatite composite with high strength and durability and large deformation capability to be useful in the regeneration of periodontal osseous defects.


Assuntos
Cimentos Ósseos/síntese química , Substitutos Ósseos/síntese química , Fosfatos de Cálcio/síntese química , Perda do Osso Alveolar/cirurgia , Materiais Biocompatíveis/química , Cimentos Ósseos/química , Regeneração Óssea , Substitutos Ósseos/química , Fosfatos de Cálcio/química , Química Farmacêutica , Quitosana/química , Cristalografia , Durapatita/química , Elasticidade , Humanos , Teste de Materiais , Microscopia Eletrônica de Varredura , Nanoestruturas , Maleabilidade , Pós , Soluções , Estresse Mecânico , Difração de Raios X
12.
J Res Natl Inst Stand Technol ; 111(3): 187-203, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-27274928

RESUMO

Staffs of the Semiconductor Electronics Division, the Information Technology Laboratory, and the Precision Engineering Laboratory at NIST, have developed a new generation of prototype Single-Crystal CD (Critical Dimension) Reference (SCCDRM) Materials with the designation RM 8111. Their intended use is calibrating metrology instruments that are used in semiconductor manufacturing. Each reference material is configured as a 10 mm × 11 mm silicon test-structure chip that is mounted in a 200 mm silicon carrier wafer. The fabrication of both the chip and the carrier wafer uses the type of lattice-plane-selective etching that is commonly employed in the fabrication of micro electro-mechanical systems devices. The certified CDs of the reference features are determined from Atomic Force Microscope (AFM) measurements that are referenced to high-resolution transmission-electron microscopy images that reveal the cross-section counts of lattice planes having a pitch whose value is traceable to the SI meter.

13.
J Biomed Mater Res A ; 68(4): 628-39, 2004 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-14986318

RESUMO

To improve the effectiveness of calcium phosphate cement (CPC), we have developed a method to seed osteoblasts into the cement. CPC powder is mixed with water to form a paste that can be shaped to fit a bone defect in situ. The paste hardens in 30 min, reacts to form hydroxyapatite, and is replaced with new bone. Reacted CPC is biocompatible but unreacted CPC paste was found to have toxic effects when placed on cell monolayers (MC3T3-E1 cells). In contrast, when cells were indirectly exposed to CPC paste using a porous membrane or by placing a coverslip containing adherent cells onto a bed of CPC paste, the unreacted CPC was nontoxic. These results suggested that gel encapsulation of the cells might protect them from the CPC paste. Thus, cells were encapsulated in alginate beads (3.6-mm diameter), mixed with CPC paste, and incubated overnight. Both vital staining (calcein-AM and ethidium homodimer-1) and the Wst-1 assay (measures dehydrogenase activity) showed that cell survival in alginate beads that were mixed with CPC was similar to survival in untreated control beads. These results suggest that gel encapsulation could be used as a mechanism to protect cells for seeding into CPC.


Assuntos
Alginatos , Substitutos Ósseos , Fosfatos de Cálcio , Ácido Glucurônico , Ácidos Hexurônicos , Osteoblastos/fisiologia , Animais , Camundongos , Óleos de Silicone
14.
Anal Chem ; 75(16): 4028-33, 2003 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-14632114

RESUMO

A radiochemical neutron activation analysis procedure has been developed, critically evaluated, and shown to have the necessary sensitivity, chemical specificity, matrix independence, and precision to certify phosphorus at ion implantation levels in silicon. 32P, produced by neutron capture of 31P, is chemically separated from the sample matrix and measured using a beta proportional counter. The method is used here to certify the amount of phosphorus in SRM 2133 (Phosphorus Implant in Silicon Depth Profile Standard) as (9.58 +/- 0.16) x 10(14) atoms x cm(-2). A detailed evaluation of uncertainties is given.

15.
Anal Chem ; 74(15): 3887-91, 2002 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-12175180

RESUMO

The detection limit is an important figure of merit for evaluating instrumentation and analytical methods. While the detection limit for techniques using linear calibration functions has been studied extensively, this fundamental metric has rarely been discussed for mass spectrometry that bases the calibration on the principle of isotope dilution. We have developed a formulation for the detection limit for isotope dilution mass spectrometry (IDMS) after a thorough analysis of the uncertainty of IDMS measurements. The new formulation describes the IDMS detection limit as a function of the enrichment of the isotopic spike and the linear calibration detection limits measured at the masses for the isotope ratio measurement.

16.
J Res Natl Inst Stand Technol ; 100(5): 575-589, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-29151762

RESUMO

The disposal of ready mixed concrete truck wash water and returned plastic concrete is a growing concern for the ready mixed concrete industry. Recently, extended set-retarding admixtures, or stabilizers, which slow or stop the hydration of portland cement have been introduced to the market. Treating truck wash-water or returned plastic concrete with stabilizing admixtures delays its setting and hardening, thereby facilitating the incorporation of these typically wasted materials in subsequent concrete batches. In a statistically designed experiment, the properties of blended concrete containing stabilized plastic concrete were evaluated. The variables in the study included (1) concrete age when stabilized, (2) stabilizer dosage, (3) holding period of the treated (stabilized) concrete prior to blending with fresh ingredients, and (4) amount of treated concrete in the blended batch. The setting time, strength, and drying shrinkage of the blended concretes were evaluated. For the conditions tested, batching 5 % treated concrete with fresh material did not have a significant effect on the setting time, strength, or drying shrinkage of the resulting blended concrete. Batching 50 % treated concrete with fresh materials had a significant effect on the setting characteristics of the blended cocnrete, which in turn affected the water demand to maintain slump. The data suggests that for a known set of conditions, the stabilizer dosage can be optimized within a relatively narrow range to produce desired setting characteristics. The strength and drying shrinkage of the blended concretes were essentially a function of the water content at different sampling ages and the relationship followed the general trend of control concrete.

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