Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 41
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
J Clin Densitom ; 25(2): 168-177, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34391642

RESUMO

We aimed to compare serum concentrations of sclerostin and DKK-1 in young (20-30 yrs, n = 25) and middle-aged (35-45 yrs, n = 25) premenopausal women and based on physical activity (PA) status. PA status was assessed by the International Physical Activity Questionnaire (low-moderate (≤ 2999 MET-min/week) and high (≥ 3000 MET-min/week). Serum sclerostin and DKK-1 levels were measured in fasting morning blood samples by ELISA. Areal bone mineral density (aBMD) was measured by DXA, and non-dominant tibia bone characteristics were assessed by pQCT. After adjusting for total body aBMD, middle-aged women had significantly (p < 0.001) higher (0.54 ± 0.01 ng/mL) serum sclerostin than young women (0.41 ± 0.01 ng/mL), and sclerostin was positively correlated with age (rs = 0.065, p ≤ 0.001) and total PA score (rs = 0.33, p = 0.021). Young women had higher left trochanter aBMD (p = 0.036) than middle-aged women and aBMD variables were higher (all p ≤ 0.043) in the high active group. Middle-aged women had higher 38% cortical vBMD than young women (p = 0.021), otherwise young women had higher values for pQCT variables (all p ≤ 0.036). Sclerostin showed significant correlations (r = 0.32 to 0.58, all p ≤ 0.026) with spine aBMD for the entire cohort and for each age group. Middle-aged women had significant correlations between sclerostin and hip aBMD sites (r = 0.043 to 0.56, all p ≤ 0.031). Sclerostin and cortical vBMD were positively correlated in the entire cohort (r = 0.35 to 0.50; both p < 0.013); split by age group, middle-aged women had positive correlations (r = 0.45 to 0.61 age and, all p ≤ 0.021) between sclerostin and pQCT variables. No significant differences for physical activity were observed for serum DKK-1 concentrations. Serum sclerostin concentrations were positively associated with age and bone characteristics in premenopausal women; however, these findings were not evident for circulating DKK-1. Further research is needed to elucidate the mechanisms for the discordant results in these Wnt inhibitors.


Assuntos
Densidade Óssea , Pré-Menopausa , Osso e Ossos , Exercício Físico , Feminino , Humanos , Pessoa de Meia-Idade , Tíbia
2.
J Pediatr ; 229: 216-222.e2, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33045237

RESUMO

OBJECTIVES: To test our hypothesis that routine year-round testing of specimens from multiple body sites and genotyping of detected virus would describe seasonal changes, increase diagnostic yield, and provide a better definition of clinical manifestations of human parechovirus (PeV-A) infections in young febrile infants. STUDY DESIGN: PeV-A reverse-transcriptase polymerase chain reaction (RT-PCR) analysis was incorporated in routine evaluation of infants aged ≤60 days hospitalized at Nationwide Children's Hospital for fever and/or suspected sepsis-like syndrome beginning in July 2013. We reviewed electronic medical records of infants who tested positive for PeV-A between July 2013 and September 2016. Genotyping was performed with specific type 3 RT-PCR and sequencing. RESULTS: Of 1475 infants evaluated, 130 (9%) tested positive for PeV-A in 1 or more sites: 100 (77%) in blood, 84 (65%) in a nonsterile site, and 53 (41%) in cerebrospinal fluid (CSF). Five infants (4%) were CSF-only positive, 31 (24%) were blood-only positive, and 20 (15%) were nonsterile site-only positive. PeV-A3 was the most common type (85%) and the only type detected in CSF. Although the majority (79%) of infections were diagnosed between July and December, PeV-A was detected year-round. The median age at detection was 29 days. Fever (96%), fussiness (75%), and lymphopenia (56%) were common. Among infants with PeV-A-positive CSF, 77% had no CSF pleocytosis. The median duration of hospitalization was 41 hours. Four infants had bacterial coinfections diagnosed within 24 hours of admission; 40 infants had viral coinfections. CONCLUSIONS: Although most frequent in summer and fall, PeV-A infections were encountered in every calendar month within the 3-year period of study. More than one-half of patients had PeV-A detected at more than 1 body site. Coinfections were common. PeV-A3 was the most common type identified and the only type detected in the CSF.


Assuntos
Infecções por Picornaviridae/diagnóstico , Líquido Cefalorraquidiano/virologia , Testes Diagnósticos de Rotina , Feminino , Febre/virologia , Técnicas de Genotipagem , Humanos , Lactente , Recém-Nascido , Masculino , Parechovirus/classificação , Parechovirus/isolamento & purificação , Infecções por Picornaviridae/sangue , Infecções por Picornaviridae/complicações , Reação em Cadeia da Polimerase em Tempo Real , Estudos Retrospectivos , Estações do Ano
3.
Int J Sport Nutr Exerc Metab ; 31(1): 32-39, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-33186897

RESUMO

The authors sought to determine whether consuming collagen peptides (CP) enhances musculoskeletal recovery of connective tissues following a damaging exercise bout. Resistance-trained males consumed 15 g/day of CP (n = 7) or placebo (n = 8), and after 7 days, maximal voluntary isometric contraction (MVIC), countermovement jump height, soreness, and collagen turnover were examined. Five sets of 20 drop jumps were performed and outcome measures were collected 24, 48, and 120 hr postexercise. Countermovement jump height was maintained in the CP group at 24 hr (PRE = 39.9 ± 8.8 cm vs. 24 hr = 37.9 ± 8.9 cm, p = .102), whereas the CP group experienced a significant decline at 24 hr (PRE = 40.4 ± 7.9 cm vs. 24 hr = 35.5 ± 6.4 cm, p = .001; d = 0.32). In both groups, muscle soreness was significantly higher than PRE at 24 hr (p = .001) and 48 hr (p = .018) but not at 120 hr (p > .05). MVIC in both legs showed a significant time effect (left: p = .007; right: p = .010) over the 5-day postexercise period. Neither collagen biomarker changed significantly at any time point. CP supplementation attenuated performance decline 24 hr following muscle damage. Acute consumption of CP may provide a performance benefit the day following a bout of damaging exercise in resistance-trained males.


Assuntos
Colágeno/administração & dosagem , Suplementos Nutricionais , Exercício Físico/fisiologia , Mialgia/prevenção & controle , Fragmentos de Peptídeos/administração & dosagem , Treinamento Resistido/efeitos adversos , Adolescente , Adulto , Biomarcadores/metabolismo , Colágeno/metabolismo , Método Duplo-Cego , Humanos , Contração Isométrica , Perna (Membro)/fisiologia , Masculino , Força Muscular , Fragmentos de Peptídeos/metabolismo , Projetos Piloto , Adulto Jovem
4.
Anal Chem ; 91(17): 11108-11115, 2019 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-31380627

RESUMO

Electron spin resonance (ESR) spectroscopy measures paramagnetic free radicals, or electron spins, in a variety of biological, chemical, and physical systems. Detection of diverse paramagnetic species is important in applications ranging from quantum computation to biomedical research. Countless efforts have been made to improve the sensitivity of ESR detection. However, the improvement comes at the cost of experimental accessibility. Thus, most ESR spectrometers are limited to specific sample geometries and compositions. Here, we present a nonresonant transmission line ESR probe (microstrip geometry) that effectively couples high frequency microwave magnetic field into a wide range of sample geometries and compositions. The nonresonant transmission line probe maintains detection sensitivity while increasing availability to a wider range of applications. The high frequency magnetic field homogeneity is greatly increased by positioning the sample between the microstrip signal line and the ground plane. Sample interfacing occurs via a universal sample holder which is compatible with both solid and liquid samples. The unavoidable loss in sensitivity due to the nonresonant nature of the transmission line probe (low Q) is recuperated by using a highly sensitive microwave interferometer-based detection circuit. The combination of our sensitive interferometer and nonresonant transmission line provides similar sensitivity to a commercially available ESR spectrometer equipped with a high-Q resonator. The nonresonant probe allows for transmission, reflection, or dual-mode detection (transmission and reflection), where the dual-mode results in a √2 signal enhancement.

5.
Pain Med ; 20(9): 1822-1830, 2019 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-30889251

RESUMO

OBJECTIVE: Athletes are at risk for developing chronic pain conditions, but the role of exercise in the modulation of pain in athletes has not been well established. The aim of this study was to investigate conditioned pain modulation (CPM) and exercise-induced hypoalgesia (EIH) responses between 13 endurance-trained athletes and 13 normally active controls. METHODS: In a cross-sectional, nonrandomized study with two independent groups of college-aged males and females, pressure pain thresholds (PPTs) were assessed in the vastus lateralis (VL) and brachioradialis (BR) using a pressure algometer before and after a conditioning stimulus, an isometric hand grip exercise to failure, and a 30-minute run. RESULTS: PPTs increased following the conditioning stimulus, indicating a CPM response, to a similar degree in the BR (19.3% ± 26.5% vs 18.6% ± 16.2%, P = 0.93) and VL (18.9% ± 25.9% vs 28.7% ± 27.4%, P = 0.73) in the athletes and controls. PPTs increased following isometric exercise to a similar extent in athletes and controls in the BR (23.9% ± 22.8% vs 28.2% ± 24.0%, P = 0.75) and VL (15.8% ± 14.8% vs 15.5% ± 11.6%, P = 0.94). Following 30 minutes of running, EIH was similar between athletes and controls in the VL (21.2% ± 17.2% vs 13.8% ± 13.3%, P = 0.23) but was attenuated in the BR of the athletes (6.1% ± 16.9% vs 20.9% ± 20%, P = 0.047). CONCLUSIONS: Athletes and controls exhibited similar endogenous pain inhibitory function both locally and systemically following CPM and isometric, upper body exercise. After the 30-minute run, BR EIH was reduced in the athletes compared with controls, suggesting a reduced systemic response following familiar exercise-perhaps due to the exercise being perceived as less painful and/or effortful.


Assuntos
Atletas , Treino Aeróbico , Limiar da Dor/fisiologia , Dor/fisiopatologia , Estudos Transversais , Feminino , Humanos , Masculino , Adulto Jovem
6.
PLoS Genet ; 12(5): e1006050, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-27223098

RESUMO

C. elegans inhabit environments that require detection of diverse stimuli to modulate locomotion in order to avoid unfavourable conditions. In a mammalian context, a failure to appropriately integrate environmental signals can lead to Parkinson's, Alzheimer's, and epilepsy. Provided that the circuitry underlying mammalian sensory integration can be prohibitively complex, we analyzed nematode behavioral responses in differing environmental contexts to evaluate the regulation of context dependent circuit reconfiguration and sensorimotor control. Our work has added to the complexity of a known parallel circuit, mediated by interneurons AVA and AIB, that integrates sensory cues and is responsible for the initiation of backwards locomotion. Our analysis of the galanin-like G-protein coupled receptor NPR-9 in C. elegans revealed that upregulation of galanin signaling impedes the integration of sensory evoked neuronal signals. Although the expression pattern of npr-9 is limited to AIB, upregulation of the receptor appears to impede AIB and AVA circuits to broadly prevent backwards locomotion, i.e. reversals, suggesting that these two pathways functionally interact. Galanin signaling similarly plays a broadly inhibitory role in mammalian models. Moreover, our identification of a mutant, which rarely initiates backwards movement, allowed us to interrogate locomotory mechanisms underlying chemotaxis. In support of the pirouette model of chemotaxis, organisms that did not exhibit reversal behavior were unable to navigate towards an attractant peak. We also assessed ionotropic glutamate receptor GLR-1 cell-specifically within AIB and determined that GLR-1 fine-tunes AIB activity to modify locomotion following reversal events. Our research highlights that signal integration underlying the initiation and fine-tuning of backwards locomotion is AIB and NPR-9 dependent, and has demonstrated the suitability of C. elegans for analysis of multisensory integration and sensorimotor control.


Assuntos
Proteínas de Caenorhabditis elegans/biossíntese , Proteínas de Caenorhabditis elegans/genética , Caenorhabditis elegans/genética , Peptídeo Semelhante a Galanina/biossíntese , Interação Gene-Ambiente , Receptores de AMPA/biossíntese , Receptores Acoplados a Proteínas G/genética , Animais , Caenorhabditis elegans/efeitos dos fármacos , Quimiotaxia/genética , Peptídeo Semelhante a Galanina/genética , Regulação da Expressão Gênica/genética , Ácido Glutâmico/metabolismo , Interneurônios/efeitos dos fármacos , Interneurônios/metabolismo , Mucosa Nasal/metabolismo , Nariz/fisiologia , Receptores de AMPA/genética , Córtex Sensório-Motor/metabolismo , Transdução de Sinais/efeitos dos fármacos
7.
Artigo em Inglês | MEDLINE | ID: mdl-31080381

RESUMO

There is an increasing number of reports on polar polymer-based Ferroelectric Field Effect Transistors (FeFETs), where the hysteresis of the drain current - gate voltage (Id-Vg) curve is investigated as the result of the ferroelectric polarization effect. However, separating ferroelectric effect from many of the factors (such as charge injection/trapping and the presence of mobile ions in the polymer) that confound interpretation is still confusing and controversial. This work presents a methodology to reliably identify the confounding factors which obscure the polarization effect in FeFETs. Careful observation of the Id-Vg curves, as well as monitoring the Id-Vg hysteresis and flat band voltage shift as a function of temperature and sweep frequency identifies the dominant mechanism. This methodology is demonstrated using 15-nm thick high glass transition temperature polar polymer-based FeFETs. In these devices, room temperature hysteresis is largely a consequence of charge trapping and mobile ions, while ferroelectric polarization is observed at elevated temperatures. This methodology can be used to unambiguously prove the effect of ferroelectric polarization in FeFETs.

8.
Artigo em Inglês | MEDLINE | ID: mdl-38868495

RESUMO

To combat the large variability problem in RRAM, current compliance elements are commonly used to limit the in-rush current during the forming operation. Regardless of the compliance element (1R-1R or 1T-1R), some degree of current overshoot is unavoidable. The peak value of the overshoot current is often used as a predictive metric of the filament characteristics and is linked to the parasitic capacitance of the test structure. The reported detrimental effects of higher parasitic capacitance seem to support this concept. However, this understanding is inconsistent with the recent successes of compliance-free ultra-short pulse forming which guarantees a maximum peak overshoot current. We use detailed circuit analysis and experimental measurements of 1R-1R and 1T-1R structures to show that the peak overshoot is independent of the parasitic capacitance while the overshoot duration is strongly dependent on the parasitic capacitance. Forming control can be achieved, in ultra-short pulse forming, since the overshoot duration is always less than the applied pulse duration. The demonstrated success of ultra-short pulse forming becomes easier to reconcile after identifying the importance of overshoot duration.

9.
Eur J Appl Physiol ; 118(7): 1407-1414, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29721605

RESUMO

Characterization of critical power/torque (CP/CT) during voluntary exercise requires maximal effort, making difficult for those with neuromuscular impairments. To address this issue we sought to determine if electrically stimulated intermittent isometric exercise resulted in a critical end-test torque (ETT) that behaved similar to voluntary CT. In the first experiment participants (n = 9) completed four bouts of stimulated exercise at a 3:2 duty cycle, at frequencies of 100, 50, 25 Hz, and a low frequency below ETT (Sub-ETT; ≤ 15 Hz). The second experiment (n = 20) consisted of four bouts at a 2:2 duty cycle-two bouts at 100 Hz, one at an intermediate frequency (15-30 Hz), and one at Sub-ETT. The third experiment (n = 12) consisted of two bouts at 50 Hz at a 3:2 duty* cycle with proximal blood flow occlusion during one of the bouts. ETT torque was similar (p ≥ 0.43) within and among stimulation frequencies in experiment 1. No fatigue was observed during the Sub-ETT bouts (p > 0.05). For experiment 2, ETT was similar at 100 Hz and at the intermediate frequency (p ≥ 0.29). Again, Sub-ETT stimulation did not result in fatigue (p > 0.05). Altering oxygen delivery by altering the duty cycle (3:2 vs. 2:2; p = 0.02) and by occlusion (p < 0.001) resulted in lower ETT values. Stimulated exercise resulted in an ETT that was consistent from day-to-day and similar regardless of initial torque, as long as that torque exceeded ETT, and was sensitive to oxygen delivery. As such we propose it represents a parameter similar to voluntary CT.


Assuntos
Potencial Evocado Motor , Contração Isométrica , Fadiga Muscular , Músculo Quadríceps/fisiologia , Torque , Adulto , Fenômenos Biomecânicos , Estimulação Elétrica , Feminino , Humanos , Masculino , Consumo de Oxigênio , Músculo Quadríceps/irrigação sanguínea , Músculo Quadríceps/inervação , Fluxo Sanguíneo Regional
10.
Artigo em Inglês | MEDLINE | ID: mdl-30983909

RESUMO

We report on a novel semiconductor reliability technique that incorporates an electrically detected magnetic resonance (EDMR) spectrometer within a conventional semiconductor wafer probing station. EDMR is an ultrasensitive electron paramagnetic resonance technique with the capability to provide detailed physical and chemical information about reliability limiting defects in semiconductor devices. EDMR measurements have generally required a complex apparatus, not typically found in solid-state electronics laboratories. The union of a semiconductor probing station with EDMR allows powerful analytical measurements to be performed within individual devices at the wafer level. Our novel approach replaces the standard magnetic resonance microwave cavity or resonator with a small non- resonant near field microwave probe. Using this new approach we have demonstrated bipolar amplification effect and spin dependent charge pumping in various SiC based MOSFET structures. Although our studies have been limited to SiC based devices, the approach will be widely applicable to other types of MOSFETs, bipolar junction transistors, and various memory devices. The replacement of the resonance cavity with the very small non- resonant microwave probe greatly simplifies the EDMR detection scheme and allows for the incorporation of this powerful tool with a wafer probing station. We believe this scheme offers great promise for widespread utilization of EDMR in semiconductor reliability laboratories.

11.
IEEE Electron Device Lett ; 38(6): 736-739, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28890601

RESUMO

The stochastic nature of the conductive filaments in oxide-based resistive memory (RRAM) represents a sizeable impediment to commercialization. As such, program-verify methodologies are highly alluring. However, it was recently shown that program-verify methods are unworkable due to strong resistance state relaxation after SET/RESET programming. In this paper, we demonstrate that resistance state relaxation is not the main culprit. Instead, it is fluctuation-induced false-reading (triggering) that defeats the program-verify method, producing a large distribution tail immediately after programming. The fluctuation impact on the verify mechanism has serious implications on the overall write/erase speed of RRAM.

12.
IEEE Trans Electron Devices ; 64(12): 5099-5016, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29375150

RESUMO

Charge-capture/emission is ubiquitous in electron devices. Its dynamics often play critical roles in device operation and reliability. Treatment of this basic process is found in many text books and is considered well understood. As in many electron device models, the individuality of immobile charge is commonly replaced with the average quantity of charge density. This has worked remarkably well when large numbers of individual charges (ensemble) are involved. As device geometries become very small, the ensemble "averaging" becomes far less accurate. In this work, the charge-capture/emission dynamic of Metal-Oxide-Semiconductor-Field-Effect-Transistor (MOSFET) is re-examined with full consideration of individual charges and the local field in their immediate vicinity. A dramatic modification of the local band diagram resulted, forcing a drastic change in emission mechanism. The implication is that many well-understood phenomena involving charge capture/emission will need to be reconsidered. As an example, this new picture is applied to the random telegraph noise (RTN) phenomenon. When the screening of a trapped charge by a polar medium such as SiO2 is quantitatively accounted for in this local field picture, a new physically sound RTN emission mechanism emerges. Similarly, the dynamics of post-stress recovery of Negative-Bias-Instability of p-channel MOSFET can be more rationally explained.

13.
Eur J Appl Physiol ; 117(11): 2225-2236, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28900719

RESUMO

OBJECTIVE: Exercise-induced muscle damage (EIMD) has been shown to reduce endurance exercise performance. This study examined the effects of EIMD on critical torque (CT) and the sum of the torque integral above CT during (∫ T total) during a 5-min all-out, intermittent isometric knee extension exercise. METHODS: CT was determined in eight participants prior to and 48-h following EIMD. EIMD was induced using electrically stimulated eccentric knee extensions until maximal voluntary strength (MVC) was reduced by 40%. EIMD was assessed by changes in MVC and ratings of muscle soreness using a VAS scale. EMG and near-infrared spectroscopy (NIRS) were collected from the vastus lateralis and vastus medialis, respectively, during the CT test to assess neuromuscular electrical activity and microvascular circulation. RESULTS: MVC decreased 22% (p = 0.006) and soreness increased from 2.1 ± 1.9 to 50.4 ± 31.5 mm (p = 0.002) 48-h following eccentric exercise. CT declined from 61.6 ± 17.8 to 52.0 ± 14.1 Nm (-14%; p = 0.005) post-EIMD. ∫ T total declined 33% (p = 0.0006) post-EIMD. No changes were observed in neuromuscular electrical activity (p = 0.95 for EMG RMS and p = 0.57 for EMG median frequency) or any parameter of microvascular circulation (p = 0.60 for tissue saturation index, p = 0.27 for total hemoglobin and myoglobin, p = 0.51 for oxyhemoglobin, and p = 0.26 for deoxyhemoglobin) between conditions. CONCLUSIONS: Our finding that EIMD-reduced CT may explain the decrements in endurance performance following EIMD observed in the previous studies. The disproportionate reduction in ∫ T total compared to MVC and CT is suggestive of a more rapid depletion of anaerobic energy stores and/or accumulation of metabolic by-products leading to fatigue following EIMD.


Assuntos
Exercício Físico , Contração Isométrica , Mialgia/fisiopatologia , Adulto , Feminino , Humanos , Joelho/fisiologia , Masculino , Fadiga Muscular , Força Muscular , Músculo Esquelético/irrigação sanguínea , Músculo Esquelético/inervação , Músculo Esquelético/fisiologia , Mialgia/etiologia , Consumo de Oxigênio , Torque
14.
IEEE Trans Electron Devices ; 63(10): 3851-3856, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28579633

RESUMO

We report a new technique for the rapid measurement of full capacitance-voltage (C-V) characteristic curves. The displacement current from a 100 MHz applied sine-wave, which swings from accumulation to strong inversion, is digitized directly using an oscilloscope from the metal-oxide-semiconductor (MOS) capacitor under test. A C-V curve can be constructed directly from this data but is severely distorted due to non-ideal behavior of real measurement systems. The key advance of this work is to extract the system response function using the same measurement set-up and a known MOS capacitor. The system response correction to the measured C-V curve of the unknown MOS capacitor can then be done by simple deconvolution. No de-skewing and/or leakage current correction is necessary, making it a very simple and quick measurement. Excellent agreement between the new fast C-V method and C-V measured conventionally by an LCR meter is achieved. The total time required for measurement and analysis is approximately 2 seconds, which is limited by our equipment.

15.
J La State Med Soc ; 168(3): 107-9, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27389381

RESUMO

Obstructive jaundice from metastatic lung cancer is extremely rare. Most reported cases have had small cell cancer of lung or adenocarcinoma of lung as primary malignancy metastasizing to the biliary system. We report the case of a patient presenting with symptoms of obstructive jaundice found to have metastatic involvement of hepatobiliary system from squamous cell cancer (SCC) of lung. ERCP (endoscopic retrograde cholangiopancreatography) with biliary stenting is the procedure of choice in such patients. Our case is made unique by the fact that technical difficulties made it difficult for the anesthesiologists to intubate the patient for an ERCP. As a result percutaneous transhepatic cholangiogram (PTC) with internal-external biliary drainage was performed.


Assuntos
Carcinoma de Células Escamosas/patologia , Neoplasias da Vesícula Biliar/secundário , Icterícia Obstrutiva/etiologia , Neoplasias Hepáticas/secundário , Neoplasias Pulmonares/patologia , Idoso , Carcinoma de Células Escamosas/complicações , Colangiopancreatografia Retrógrada Endoscópica , Colangiopancreatografia por Ressonância Magnética , Drenagem , Humanos , Fígado/patologia , Neoplasias Pulmonares/complicações , Masculino
16.
Anal Chem ; 87(9): 4910-6, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25867553

RESUMO

Electron spin resonance (ESR) spectroscopy's affinity for detecting paramagnetic free radicals, or spins, has been increasingly employed to examine a large variety of biochemical interactions. Such paramagnetic species are broadly found in nature and can be intrinsic (defects in solid-state materials systems, electron/hole pairs, stable radicals in proteins) or, more often, purposefully introduced into the material of interest (doping/attachment of paramagnetic spin labels to biomolecules of interest). Using ESR to trace the reactionary path of paramagnetic spins or spin-active proxy molecules provides detailed information about the reaction's transient species and the label's local environment. For many biochemical systems, like those involving membrane proteins, synthesizing the necessary quantity of spin-labeled biomolecules (typically 50 pmol to 100 pmol) is quite challenging and often limits the possible biochemical reactions available for investigation. Quite simply, ESR is too insensitive. Here, we demonstrate an innovative approach that greatly enhances ESR's sensitivity (>20000× improvement) by developing a near-field, nonresonant, X-band ESR spectrometric method. Sensitivity improvement is confirmed via measurement of 140 amol of the most common nitroxide spin label in a ≈593 fL liquid cell at ambient temperature and pressure. This experimental approach eliminates many of the typical ESR sample restrictions imposed by conventional resonator-based ESR detection and renders the technique feasible for spatially resolved measurements on a wider variety of biochemical samples. Thus, our approach broadens the pool of possible biochemical and structural biology studies, as well as greatly enhances the analytical power of existing ESR applications.


Assuntos
Proteínas de Membrana/análise , Espectroscopia de Ressonância de Spin Eletrônica , Radicais Livres/análise , Micro-Ondas
18.
J Clin Microbiol ; 51(2): 615-7, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23175266

RESUMO

Abilities to detect heterogeneity of ospC genotypes of the Lyme disease spirochete Borrelia burgdorferi in the tick vector by in vitro culture (IVC) and direct PCR (dPCR) were compared. IVC failed to detect one-third of the ospC genotypes detected by dPCR. Among IVC results, common ospC genotypes were overrepresented while occurrence of rare genotypes was underestimated.


Assuntos
Borrelia burgdorferi/genética , Variação Genética , Ixodes/microbiologia , Animais , Antígenos de Bactérias/genética , Proteínas da Membrana Bacteriana Externa/genética , Borrelia burgdorferi/classificação , Feminino , Frequência do Gene , Genótipo , Masculino
19.
Artigo em Inglês | MEDLINE | ID: mdl-37479955

RESUMO

OBJECTIVE: To examine the association of patient-provider racial and ethnic concordance on healthcare use within Hispanic ethnic subgroups. METHODS: We estimate multivariate probit models using data from the Medical Expenditure Panel Survey, the only national data source measuring how patients use and pay for medical care, health insurance, and out-of-pocket spending. We collect and utilize data on preventive care visits, visits for new health problems, and visits for ongoing health problems from survey years 2007-2017 to measure health outcomes. Additionally, we include data on race and ethnicity concordance, non-health-related socioeconomic and demographic factors, health-related characteristics, provider communication characteristics, and provider location characteristics in the analysis. The sample includes 59,158 observations: 74.3% identified as Mexican, 10.6% identified as Puerto Rican, 5.1% identified as Cuban, 4.8% identified as Dominican, and 5.2% classified in the survey as Other Hispanics. Foreign-born respondents comprised 56% of the sample. A total of 8% (4678) of cases in the sample involved Hispanic provider-patient concordance. RESULTS: Hispanic patient-provider concordance is statistically significant and positively associated with higher probabilities of seeking preventive care (coef=.211, P<.001), seeking care for a new problem (coef=.208, P<.001), and seeking care for an ongoing problem (coef=.208, P<.001). We also find that the association is not equal across the Hispanic subgroups. The association is lowest for Mexicans in preventive care (coef=.165, P<.001) and new problems (coef=.165, P<.001) and highest for Cubans in preventive care (coef=.256, P<.001) and ongoing problems (coef=.284, P<.001). Results are robust to the interaction of the Hispanic patient-provider concordance for the Hispanic patient categories and being foreign-born. CONCLUSIONS: In summary, racial disparities were observed in health utilization within Hispanic subgroups. While Hispanic patient-provider concordance is statistically significant in associating with healthcare utilization, the findings indicate that this association varies across Hispanic subpopulations. The observations suggest the importance of disaggregating Hispanic racial and ethnic categories into more similar cultural or origin groups. Linked with the existence of significant differences in mortality and other health outcomes across Hispanic subgroups, our results have implications for the design of community health promotion activities which should take these differences into account. Studies or community health programs which utilize generalized findings about Hispanic populations overlook differences across subgroups which may be crucial in promoting healthcare utilization.

20.
J Foot Ankle Surg ; 51(1): 63-8, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22196459

RESUMO

The incidence of deep vein thrombosis (DVT) after foot and ankle surgery is generally believed to be low. However, little information is available regarding DVT as it specifically relates to foot and ankle trauma. The National Trauma Data Bank data set (2007 to 2009) was used to evaluate the incidence of thromboembolism in foot and ankle trauma. Also, the risk factors associated with the thromboembolic events were identified. Data regarding the demographics, comorbidities, procedures, trauma types, and complications, including DVT and pulmonary embolism (PE), were collected from the data set for analysis. The incidence of DVT and PE was 0.28% and 0.21%, respectively. The risk factors statistically significantly associated and clinically relevant for both DVT and PE in foot and ankle trauma were older age (DVT, odds ratio [OR] 1.02, 95% confidence interval [CI] 1.01 to 1.03; PE, OR 1.02, 95% CI 1.01 to 1.03), obesity (DVT, OR 2.35, 95% CI 1.33 to 4.14; PE, OR 3.06, 95% CI 1.68 to 5.59), and higher injury severity score (DVT, OR 1.22, 95% CI 1.16 to 1.28; PE, OR 1.21, 95% CI 1.14 to 1.29). Owing to the low incidence, routine pharmacologic thromboprophylaxis might be contraindicated in foot and ankle trauma. Instead, careful, individualized assessment of the risk factors associated with DVT/PE is important.


Assuntos
Traumatismos do Tornozelo/epidemiologia , Traumatismos do Pé/epidemiologia , Embolia Pulmonar/epidemiologia , Trombose Venosa/epidemiologia , Adulto , Fatores Etários , Anticoagulantes/efeitos adversos , Transtornos da Coagulação Sanguínea/epidemiologia , Bases de Dados como Assunto , Diabetes Mellitus/epidemiologia , Feminino , Fraturas Fechadas/epidemiologia , Fraturas Expostas/epidemiologia , Insuficiência Cardíaca/epidemiologia , Humanos , Hipertensão/epidemiologia , Incidência , Escala de Gravidade do Ferimento , Modelos Logísticos , Masculino , Infarto do Miocárdio/epidemiologia , Obesidade/epidemiologia , Embolia Pulmonar/prevenção & controle , Diálise Renal , Síndrome do Desconforto Respiratório/epidemiologia , Fatores de Risco , Acidente Vascular Cerebral/epidemiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA