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1.
Med Ref Serv Q ; 43(1): 72-79, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38237024

RESUMO

Medical librarians can increase their work visibility and highlight their unique role on evidence synthesis teams with searchRxiv, an open access repository that makes librarian's efforts easily citable and resolves longstanding challenges pertaining to reproducing full search strategies within literature review articles. This column will discuss how to navigate searchRxiv to find, reuse, and cite published search strategies, as well as the process of depositing search strategies.


Assuntos
Bases de Dados Bibliográficas
2.
Clin Gastroenterol Hepatol ; 21(10): 2508-2525.e10, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-36470529

RESUMO

BACKGROUND & AIMS: This study aimed (1) to systematically review controlled trials of solid food diets for the treatment of inflammatory bowel disease (IBD); and (2) to grade the overall quality of evidence. METHODS: Systematic review of prospective controlled trials of solid food diets for the induction or maintenance of remission in IBD. Two authors independently performed study selection, data extraction, and assessment of certainty of evidence. Meta-analyses were performed on studies with quantitative data on response, remission, and relapse. RESULTS: There were 27 studies for meta-analysis. For induction of remission in Crohn's disease (CD), low refined carbohydrate diet and symptoms-guided diet outperformed controls, but studies had serious imprecision and very low certainty of evidence. The Mediterranean diet was similar to the Specific Carbohydrate Diet (low certainty of evidence), and partial enteral nutrition (PEN) was similar to exclusive enteral nutrition (very low certainty of evidence). PEN reduced risk of relapse (very low certainty of evidence), whereas reduction of red meat or refined carbohydrates did not (low certainty of evidence). For ulcerative colitis, diets were similar to controls (very low and low certainty of evidence). CONCLUSIONS: Among the most robust dietary trials in IBD currently available, certainty of evidence remains very low or low. Nonetheless, emerging data suggest potential benefit with PEN for induction and maintenance of remission in CD. Reduction of red meat and refined carbohydrates might not reduce risk of CD relapse. As more dietary studies become available, the certainty of evidence could improve, thus allowing for more meaningful recommendations for patients.


Assuntos
Doença de Crohn , Doenças Inflamatórias Intestinais , Humanos , Estudos Prospectivos , Doenças Inflamatórias Intestinais/terapia , Doença de Crohn/terapia , Indução de Remissão , Carboidratos , Recidiva
3.
Magn Reson Med ; 90(6): 2572-2591, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37667645

RESUMO

PURPOSE: Developing a general framework with a novel stochastic offset strategy for the design of optimized RF pulses and time-varying spatially non-linear ΔB0 shim array fields for restricted slice excitation and refocusing with refined magnetization profiles within the intervals of the fixed voxels. METHODS: Our framework uses the decomposition property of the Bloch equations to enable joint design of RF-pulses and shim array fields for restricted slice excitation and refocusing with auto-differentiation optimization. Bloch simulations are performed independently on orthogonal basis vectors, Mx, My, and Mz, which enables designs for arbitrary initial magnetizations. Requirements for refocusing pulse designs are derived from the extended phase graph formalism obviating time-consuming sub-voxel isochromatic simulations to model the effects of crusher gradients. To refine resultant slice-profiles because of voxelwise optimization functions, we propose an algorithm that stochastically offsets spatial points at which loss is computed during optimization. RESULTS: We first applied our proposed design framework to standard slice-selective excitation and refocusing pulses in the absence of non-linear ΔB0 shim array fields and compared them against pulses designed with Shinnar-Le Roux algorithm. Next, we demonstrated our technique in a simulated setup of fetal brain imaging in pregnancy for restricted-slice excitation and refocusing of the fetal brain. CONCLUSIONS: Our proposed framework for optimizing RF pulse and time-varying spatially non-linear ΔB0 shim array fields achieve high fidelity restricted-slice excitation and refocusing for fetal MRI, which could enable zoomed fast-spin-echo-MRI and other applications.


Assuntos
Aumento da Imagem , Imageamento por Ressonância Magnética , Aumento da Imagem/métodos , Imageamento por Ressonância Magnética/métodos , Algoritmos , Imagens de Fantasmas
4.
Magn Reson Med ; 90(2): 483-501, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37093775

RESUMO

PURPOSE: To improve time-resolved reconstructions by training auto-encoders to learn compact representations of Bloch-simulated signal evolution and inserting the decoder into the forward model. METHODS: Building on model-based nonlinear and linear subspace techniques, we train auto-encoders on dictionaries of simulated signal evolution to learn compact, nonlinear, latent representations. The proposed latent signal model framework inserts the decoder portion of the auto-encoder into the forward model and directly reconstructs the latent representation. Latent signal models essentially serve as a proxy for fast and feasible differentiation through the Bloch equations used to simulate signal. This work performs experiments in the context of T2 -shuffling, gradient echo EPTI, and MPRAGE-shuffling. We compare how efficiently auto-encoders represent signal evolution in comparison to linear subspaces. Simulation and in vivo experiments then evaluate if reducing degrees of freedom by incorporating our proxy for the Bloch equations, the decoder portion of the auto-encoder, into the forward model improves reconstructions in comparison to subspace constraints. RESULTS: An auto-encoder with 1 real latent variable represents single-tissue fast spin echo, EPTI, and MPRAGE signal evolution to within 0.15% normalized RMS error, enabling reconstruction problems with 3 degrees of freedom per voxel (real latent variable + complex scaling) in comparison to linear models with 4-8 degrees of freedom per voxel. In simulated/in vivo T2 -shuffling and in vivo EPTI experiments, the proposed framework achieves consistent quantitative normalized RMS error improvement over linear approaches. From qualitative evaluation, the proposed approach yields images with reduced blurring and noise amplification in MPRAGE-shuffling experiments. CONCLUSION: Directly solving for nonlinear latent representations of signal evolution improves time-resolved MRI reconstructions.


Assuntos
Algoritmos , Imageamento por Ressonância Magnética , Imageamento por Ressonância Magnética/métodos , Simulação por Computador , Processamento de Imagem Assistida por Computador/métodos
5.
Int Rev Psychiatry ; 35(7-8): 566-575, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38461387

RESUMO

PURPOSE: This systematic review seeks to understand what outcomes have been reported for arts and humanities programs in surgery education. METHODS: Authors searched Medline ALL (Ovid), Embase.com, Web of Science, and Academic Search Ultimate to identify articles on evaluated arts and humanities programs in surgery education. The search identified 1,282 titles and abstracts, of which 55 underwent independent full-text review. The authors identified 10 articles that met inclusion criteria, from which they collected and analysed data. RESULTS: Medical students were the identified learners in most studies (6/10; 60%). Reflective writing was the arts and humanities activity in half of the studies (5/10; 50%); activities based on film, visual art other than film, literature, or social media in the remaining studies (5/10; 50%). Most studies (8/10; 80%) featured a non-controlled, non-randomized design. Authors categorised 5 studies (50%) as Kirkpatrick Level 1, 4 (40%) as Level 2, and 1 (10%) as Level 3. CONCLUSION: Integration of the arts and humanities into surgery education may promote increased levels of learner reflection and empathy, in addition to improved acquisition of surgical skills. More rigorous evaluation of these programs would clarify the impact of arts and humanities programs on surgery learners.


Assuntos
Educação de Graduação em Medicina , Estudantes de Medicina , Humanos , Currículo , Ciências Humanas/educação , Empatia
6.
Int Rev Psychiatry ; 35(7-8): 540-550, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38461397

RESUMO

This systematic review characterizes the published literature on arts and humanities curricula for psychiatry learners that include any form of program evaluation. Authors searched three databases (Medline ALL, Embase.com, and PsycINFO) to identify articles on arts and humanities in psychiatry education. Criteria for the review included articles reporting outcome measures for arts and humanities learning activities in psychiatry learners. For those articles meeting inclusion criteria, a descriptive analysis was performed as well as an assessment of the level of program evaluation using the Kirkpatrick framework. Of 1,287 articles identified, 35 met inclusion criteria. About half of the programs included medical students (n = 17, 49%). Film and television was the most frequent arts and humanities subject (n = 16, 46%). Most studies incorporated a non-randomized, non-controlled design (n = 30, 86%). Twenty-two (63%) achieved a Kirkpatrick Level 1 designation, 12 achieved Level 2 (34%), and one study achieved Level 3 (3%). Arts and humanities programs have a promising role in psychiatry education. At present, significant heterogeneity in the extant literature makes it difficult to draw general conclusions that could guide future program development. This review underscores the need for rigorous evaluative methods of arts and humanities programs for psychiatry learners.


Assuntos
Educação de Graduação em Medicina , Educação Médica , Humanos , Ciências Humanas/educação , Currículo , Aprendizagem
7.
Sensors (Basel) ; 23(13)2023 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-37447926

RESUMO

In passive BCI studies, a common approach is to collect data from mental states of interest during relatively long trials and divide these trials into shorter "epochs" to serve as individual samples in classification. While it is known that using k-fold cross-validation (CV) in this scenario can result in unreliable estimates of mental state separability (due to autocorrelation in the samples derived from the same trial), k-fold CV is still commonly used and reported in passive BCI studies. What is not known is the extent to which k-fold CV misrepresents true mental state separability. This makes it difficult to interpret the results of studies that use it. Furthermore, if the seriousness of the problem were clearly known, perhaps more researchers would be aware that they should avoid it. In this work, a novel experiment explored how the degree of correlation among samples within a class affects EEG-based mental state classification accuracy estimated by k-fold CV. Results were compared to a ground-truth (GT) accuracy and to "block-wise" CV, an alternative to k-fold which is purported to alleviate the autocorrelation issues. Factors such as the degree of true class separability and the feature set and classifier used were also explored. The results show that, under some conditions, k-fold CV inflated the GT classification accuracy by up to 25%, but block-wise CV underestimated the GT accuracy by as much as 11%. It is our recommendation that the number of samples derived from the same trial should be reduced whenever possible in single-subject analysis, and that both the k-fold and block-wise CV results are reported.


Assuntos
Interfaces Cérebro-Computador , Eletroencefalografia/métodos , Projetos de Pesquisa , Algoritmos
8.
Magn Reson Med ; 87(5): 2161-2177, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-34931714

RESUMO

PURPOSE: To demonstrate, through numerical simulations, novel designs of spatially selective radiofrequency (RF) excitations of the fetal brain by both a restricted 2D slice and 3D inner-volume selection. These designs exploit a single-channel RF pulse, conventional gradient fields, and the spatially non-linear ΔB0 fields of a multi-coil shim array, using an auto-differentiation optimization algorithm. METHODS: The design algorithm jointly optimizes the RF pulse and the time-varying ΔB0 fields, which is produced by a 64-channel multi-coil ΔB0 body array to augment the RF and the linear gradient fields, using an auto-differentiation approach. Two design targets were specified, one a 4-mm thick slice with a limited in-slice extent in one dimension ("restricted slice"), and the other a 3D inner-volume selection encompassing the fetal brain ("inner volume"). The RF duration was limited to 2 ms for the restricted slice excitation and 6 ms for the inner-volume excitation. RESULTS: Excitation profiles were achieved for both the restricted slice excitation task (one-minus-minimum magnitude, 8%) within the region of interest (ROI) and (maximum-minus-zero magnitude, 8%) in the suppressed regions and the fetal brain volume excitation task (13% and 9%, respectively). CONCLUSIONS: The proposed joint design of RF and time-varying, spatially non-linear ΔB0 fields achieves the target excitation profiles with short RF pulse durations and demonstrates the potential to enhance fetal MRI with multi-channel body shim arrays.


Assuntos
Imageamento por Ressonância Magnética , Ondas de Rádio , Algoritmos , Encéfalo/diagnóstico por imagem , Frequência Cardíaca , Imageamento por Ressonância Magnética/métodos , Imagens de Fantasmas
9.
Magn Reson Med ; 87(2): 1074-1092, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34632626

RESUMO

PURPOSE: To test an integrated "AC/DC" array approach at 7T, where B0 inhomogeneity poses an obstacle for functional imaging, diffusion-weighted MRI, MR spectroscopy, and other applications. METHODS: A close-fitting 7T 31-channel (31-ch) brain array was constructed and tested using combined Rx and ΔB0 shim channels driven by a set of rapidly switchable current amplifiers. The coil was compared to a shape-matched 31-ch reference receive-only array for RF safety, signal-to-noise ratio (SNR), and inter-element noise correlation. We characterize the coil array's ability to provide global and dynamic (slice-optimized) shimming using ΔB0 field maps and echo planar imaging (EPI) acquisitions. RESULTS: The SNR and average noise correlation were similar to the 31-ch reference array. Global and slice-optimized shimming provide 11% and 40% improvements respectively compared to baseline second-order spherical harmonic shimming. Birdcage transmit coil efficiency was similar for the reference and AC/DC array setups. CONCLUSION: Adding ΔB0 shim capability to a 31-ch 7T receive array can significantly boost 7T brain B0 homogeneity without sacrificing the array's rdiofrequency performance, potentially improving ultra-high field neuroimaging applications that are vulnerable to off-resonance effects.


Assuntos
Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Encéfalo/diagnóstico por imagem , Imagem Ecoplanar , Imagens de Fantasmas , Ondas de Rádio , Razão Sinal-Ruído
10.
NMR Biomed ; 35(1): e4621, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34609036

RESUMO

MR spectroscopic imaging (MRSI) noninvasively maps the metabolism of human brains. In particular, the imaging of D-2-hydroxyglutarate (2HG) produced by glioma isocitrate dehydrogenase (IDH) mutations has become a key application in neuro-oncology. However, the performance of full field-of-view MRSI is limited by B0 spatial nonuniformity and lipid artifacts from tissues surrounding the brain. Array coils that multiplex RF-receive and B0 -shim electrical currents (AC/DC mixing) over the same conductive loops provide many degrees of freedom to improve B0 uniformity and reduce lipid artifacts. AC/DC coils are highly efficient due to compact design, requiring low shim currents (<2 A) that can be switched fast (0.5 ms) with high interscan reproducibility (10% coefficient of variation for repeat measurements). We measured four tumor patients and five volunteers at 3 T and show that using AC/DC coils in addition to the vendor-provided second-order spherical harmonics shim provides 19% narrower spectral linewidth, 6% higher SNR, and 23% less lipid content for unrestricted field-of-view MRSI, compared with the vendor-provided shim alone. We demonstrate that improvement in MRSI data quality led to 2HG maps with higher contrast-to-noise ratio for tumors that coincide better with the FLAIR-enhancing lesions in mutant IDH glioma patients. Smaller Cramér-Rao lower bounds for 2HG quantification are obtained in tumors by AC/DC shim, corroborating with simulations that predicted improved accuracy and precision for narrower linewidths. AC/DC coils can be used synergistically with optimized acquisition schemes to improve metabolic imaging for precision oncology of glioma patients. Furthermore, this methodology has broad applicability to other neurological disorders and neuroscience.


Assuntos
Neoplasias Encefálicas/diagnóstico por imagem , Glioma/diagnóstico por imagem , Glutaratos/análise , Isocitrato Desidrogenase/fisiologia , Imageamento por Ressonância Magnética/métodos , Adulto , Neoplasias Encefálicas/metabolismo , Feminino , Glioma/metabolismo , Humanos , Isocitrato Desidrogenase/genética , Masculino , Mutação
11.
IEEE Trans Antennas Propag ; 70(1): 459-471, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35110782

RESUMO

In this work, we propose a method for the compression of the coupling matrix in volume-surface integral equation (VSIE) formulations. VSIE methods are used for electromagnetic analysis in magnetic resonance imaging (MRI) applications, for which the coupling matrix models the interactions between the coil and the body. We showed that these effects can be represented as independent interactions between remote elements in 3D tensor formats, and subsequently decomposed with the Tucker model. Our method can work in tandem with the adaptive cross approximation technique to provide fast solutions of VSIE problems. We demonstrated that our compression approaches can enable the use of VSIE matrices of prohibitive memory requirements, by allowing the effective use of modern graphical processing units (GPUs) to accelerate the arising matrix-vector products. This is critical to enable numerical MRI simulations at clinical voxel resolutions in a feasible computation time. In this paper, we demonstrate that the VSIE matrix-vector products needed to calculate the electromagnetic field produced by an MRI coil inside a numerical body model with 1 mm3 voxel resolution, could be performed in ~ 33 seconds in a GPU, after compressing the associated coupling matrix from ~ 80 TB to ~ 43 MB.

12.
BMC Musculoskelet Disord ; 23(1): 813, 2022 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-36008858

RESUMO

BACKGROUND: The greater likelihood of morbidity, mortality, length of hospital stays and poorer long-term outcomes as a result of surgical site infections secondary to spinal surgery makes prophylactic measures an imperative focus. Therefore, the aim of this review was to evaluate the available research related to the efficacy of different intraoperative irrigation techniques used in spinal surgery for surgical site infection (SSI) prophylaxis. METHODS: We performed a comprehensive search using Ovid Medline, EMBASE, Web of Science and the Cochrane library pertaining to this topic. Our meta-analysis was conducted according to PRISMA guidelines. The inclusion criteria consist of spine surgeries with intraoperative use of any wound irrigation technique, comparison groups with a different intraoperative irrigation technique or no irrigation, SSI identified with bacterial cultures or clinically in the postoperative period, reported SSI rates. Data extracted from eligible studies included, but was not limited to, SSI rates, irrigation technique and control technique. Exclusion criteria consist of articles with no human subjects, reviews, meta-analyses and case control studies and no details about SSI identification or rates. Pooled risk ratios were calculated. A meta-analysis was performed with a forest plot to determine risk estimates' heterogeneity with I2 index, Q-statistic, and p value under a random-effects model. Funnel plot was used to assess publication bias. All databases were last checked on January, 2022. PROBAST tool was used to assess both risk of bias and applicability concerns. RESULTS: After reviewing 1494 titles and abstracts, 18 articles met inclusion criteria. They included three prospective randomized-controlled trials, 13 retrospective cohort studies, two prospective cohort studies. There were 54 (1.8%) cases of SSIs in the povidone-iodine irrigation group (N = 2944) compared to 159 (4.6%) in the control group (N = 3408). Using intraoperative povidone-iodine wound irrigation produced an absolute risk reduction of 2.8%. Overall risk ratio was 0.32 (95% CI 0.20-0.53, p < 0.00001). In a global analysis, study heterogeneity and synthesizing mostly retrospective data were primary limitations. CONCLUSION: The most evidence exists for povidone-iodine and has Level 2 evidence supporting SSI reduction during spinal surgery. Other antiseptic solutions such as dilute chlorhexidine lack published evidence in this patient population which limits the ability to draw conclusions related to its use in spinal surgery. LEVEL OF EVIDENCE: II - Systematic Review with Meta-Analysis.


Assuntos
Povidona-Iodo , Infecção da Ferida Cirúrgica , Humanos , Povidona-Iodo/uso terapêutico , Estudos Prospectivos , Estudos Retrospectivos , Infecção da Ferida Cirúrgica/epidemiologia , Irrigação Terapêutica/efeitos adversos , Irrigação Terapêutica/métodos
13.
Magn Reson Med ; 85(1): 429-443, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32643152

RESUMO

PURPOSE: We propose a fast, patient-specific workflow for on-line specific absorption rate (SAR) supervision. An individualized electromagnetic model is created while the subject is on the table, followed by rapid SAR estimates for that individual. Our goal is an improved correspondence between the patient and model, reducing reliance on general anatomical body models. METHODS: A 3D fat-water 3T acquisition (~2 minutes) is automatically segmented using a computer vision algorithm (~1 minute) into what we found to be the most important electromagnetic tissue classes: air, bone, fat, and soft tissues. We then compute the individual's EM field exposure and global and local SAR matrices using a fast electromagnetic integral equation solver. We assess the approach in 10 volunteers and compare to the SAR seen in a standard generic body model (Duke). RESULTS: The on-the-table workflow averaged 7'44″. Simulation of the simplified Duke models confirmed that only air, bone, fat, and soft tissue classes are needed to estimate global and local SAR with an error of 6.7% and 2.7%, respectively, compared to the full model. In contrast, our volunteers showed a 16.0% and 20.3% population variability in global and local SAR, respectively, which was mostly underestimated by the Duke model. CONCLUSION: Timely construction and deployment of a patient-specific model is computationally feasible. The benefit of resolving the population heterogeneity compared favorably to the modest modeling error incurred. This suggests that individualized SAR estimates can improve electromagnetic safety in MRI and possibly reduce conservative safety margins that account for patient-model mismatch, especially in non-standard patients.


Assuntos
Algoritmos , Imageamento por Ressonância Magnética , Simulação por Computador , Computadores , Campos Eletromagnéticos , Humanos
14.
Neuroimage ; 207: 116396, 2020 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-31778818

RESUMO

Functional magnetic resonance imaging (fMRI) in monkeys is important for bridging the gap between invasive animal brain studies and non-invasive human brain studies. To resolve the finer functional structure of the monkey brain, ultra-high-field (UHF) MR is essential, and high-performance, close-fitting RF receive coils are typically desired to fully leverage the intrinsic gains provided by UHF MRI. Moreover, static field (B0) inhomogeneity arising from the tissue susceptibility interface is more severe at UHF, presenting an obstacle to achieving high-resolution fMRI. B0 shim of the monkey head is challenging due to its smaller size and more complex sources of B0 offsets in multi-modal imaging tasks. In the present work, we have customized an array coil for lightly-anesthetized monkey fMRI in the 7T human scanner that combines RF and multi-coil (MC) B0 shim functionality (also referred to as AC/DC coils) to provide high imaging SNR and high-spatial-order, rapidly switchable B0-shim capability. Additional space was retained on the coil to render it compatible with monkey multi-modal imaging studies. Both MC global (whole-volume) and dynamic (slice-optimized) shim methods were tested and evaluated, and the benefits of MC shim for fMRI experiments was also studied. A minor reduction in RF coil performance was found after introducing additional B0 shim circuitry. However, the proposed RF coil provided higher image SNR and more uniform contrast compared to a commercially available coil for human knee imaging. Compared with static 2nd-order shim, the B0 inhomogeneity was reduced by 56.8%, and 95-percentile B0 offset was reduced to within 28.2 Hz through MC shim, versus 68.7 Hz with 2nd-order static shim. As a result, functional image quality could be improved, and brain activation can be better detected using the proposed AC/DC monkey coil.


Assuntos
Encéfalo/fisiologia , Cabeça/fisiologia , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Neuroimagem , Imagem Ecoplanar/métodos , Humanos , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Neuroimagem/métodos , Imagens de Fantasmas , Ondas de Rádio
15.
Chemistry ; 26(36): 8115-8120, 2020 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-32176819

RESUMO

We report the synthesis and characterization of K4 {[PuCl2 (NO3 )3 ]2 (µ2 -O)}⋅H2 O, which contains the first known µ2 -oxo bridge between two PuIV metal centers. Adding to its uniqueness is the Pu-(µ2 -O) bond length of 2.04 Å, which is the shortest of other analogous compounds. The Pu-(µ2 -O)-Pu bridge is characterized by the mixing of s-, d-, and p-orbitals from Pu with the p-orbitals of O; the 5f-orbitals do not participate in bonding. Natural bond orbital analysis indicates that Pu and O interact through one 3c-2e σPu-O-Pu and two 3c-2e πPu-O-Pu bonding orbitals and that the electron density is highly polarized on the µ2 -O. Bond topology properties analysis indicates that the Pu-(µ2 -O) bond shares both ionic and covalent character. Quantum mechanical calculations also show that the dimer has multiconfigurational ground states, where the nonet, septet, quintet, triplet, and singlet are close in energy. This work demonstrates the interplay between experimental and computational efforts that is required to understand the chemical bonding of Pu compounds.

16.
Med Ref Serv Q ; 39(4): 382-387, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33085945

RESUMO

After years of strategic planning, the National Library of Medicine has introduced an updated and redesigned version of its PubMed health sciences research website. The new website features a more modern and responsive interface, especially on mobile devices. Tools and features have been relocated to make them more intuitive for new users. While not without some turbulence and slight discomfort for long-time users adjusting to the modernized interface and search engine, the new version of the PubMed website introduced in 2020 succeeds in the website's time-honored task of collecting and making freely accessible high-quality health sciences information and resources.


Assuntos
Coleta de Dados/métodos , Disseminação de Informação/métodos , Internet , National Library of Medicine (U.S.) , PubMed/organização & administração , Relatório de Pesquisa , Ferramenta de Busca , Humanos , Estados Unidos
17.
J Am Chem Soc ; 141(30): 11842-11846, 2019 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-31327227

RESUMO

An isostructural series of Np(V) MOFs with shp-topology were synthesized and characterized. X-ray diffraction data revealed an unusual wheel-shaped node of 18 neptunyl polyhedra stabilized in the framework. Strong distortion in local coordination of the neptunium atoms is evidenced by Np-Oyl bond lengths that lie outside the typical range for Np(V). The structure was further interrogated by Raman spectroscopy and density functional theory calculations to assign the vibrational modes.

18.
Curr Opin Pediatr ; 31(1): 166-174, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30531224

RESUMO

PURPOSE OF REVIEW: To provide an up-to-date clinical review of U.S. Food and Drug Administration (FDA)-approved stimulant medications for attention-deficit/hyperactivity disorder (ADHD), including a framework for individualized treatment by primary care pediatric providers. RECENT FINDINGS: Stimulant medications are first-line agents for pediatric ADHD. Since 2012, 11 novel stimulant medications have been approved by the FDA for the treatment of ADHD. Because of an expanded formulary of available methylphenidate-based and amphetamine-based stimulants, primary care providers may be unfamiliar with some novel medications outside a select formulary. SUMMARY: The current broad formulary of methylphenidate-based and amphetamine-based stimulants provides primary care clinicians with a greater opportunity for personalized medicine within the patient-centered medical home. Through a systematic review of prior relevant medication trials, a consideration of daily symptom burden and thoughtful pragmatics, primary care providers can offer a more precise, customized stimulant treatment.


Assuntos
Transtorno do Deficit de Atenção com Hiperatividade , Estimulantes do Sistema Nervoso Central , Metilfenidato , Transtorno do Deficit de Atenção com Hiperatividade/tratamento farmacológico , Estimulantes do Sistema Nervoso Central/uso terapêutico , Criança , Humanos , Metilfenidato/uso terapêutico , Atenção Primária à Saúde
19.
J Opt Soc Am A Opt Image Sci Vis ; 36(6): 1079-1088, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-31158140

RESUMO

Recently, the volume integral equation (VIE) approach has been proposed as an efficient simulation tool for silicon photonics applications [J. Lightw. Technol.36, 3765 (2018)JLTEDG0733-872410.1109/JLT.2018.2842054]. However, for the high-frequency and strong-contrast problems arising in photonics, the convergence of iterative solvers for the solution of the linear system can be extremely slow. The uniform discretization of the volume integral operator leads to a three-level Toeplitz matrix, which is well suited to preconditioning via its circulant approximation. In this paper, we describe an effective circulant preconditioning strategy based on the multilevel circulant preconditioner of Chan and Olkin [Numer. Algorithms6, 89 (1994)NUALEG1017-139810.1007/BF02149764]. We show that this approach proves ideal in the canonical photonics problem of propagation within a uniform waveguide, in which the flow is unidirectional. For more complex photonics structures, such as Bragg gratings, directional couplers, and disk resonators, we generalize our preconditioning strategy via geometrical partitioning (leading to a block-diagonal circulant preconditioner) and homogenization (for inhomogeneous structures). Finally, we introduce a novel memory reduction technique enabling the preconditioner's memory footprint to remain manageable, even for extremely long structures. The range of numerical results we present demonstrates that the preconditioned VIE is fast and has great utility for the numerical exploration of prototype photonics devices.

20.
J Clin Psychol ; 75(12): 2248-2258, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31386196

RESUMO

OBJECTIVE: The purpose of the present study was to compare psychometric properties of the Substance Abuse (SUB) Scale on the Korean Minnesota Multiphasic Personality Inventory-Adolescent-Restructured Form (MMPI-A-RF) with those on the Korean MMPI-A (the Alcohol/Drug Problem Acknowledgment Scale [ACK]), the Alcohol/Drug Problem Proneness Scale [PRO], and the MacAndrew Alcoholism Scale-Revised Scale [MAC-R]). METHOD: Participants consisted of 237 Korean adolescent psychiatric patients whose scores on these measures were compared in terms of internal consistency and predictive validity. RESULTS: Scores on SUB exhibited superior internal consistency to that of the MMPI-A substance abuse scales. Further, scores on SUB predicted substance abuse more accurately than did the optimal combination of scores on the MMPI-A substance abuse scales. CONCLUSION: Results provide strong support for the use of the Korean MMPI-A-RF SUB scale when assessing substance abuse in Korean youth.


Assuntos
Alcoolismo/diagnóstico , Comparação Transcultural , MMPI/estatística & dados numéricos , Transtornos Relacionados ao Uso de Substâncias/diagnóstico , Transtornos Relacionados ao Uso de Substâncias/psicologia , Adolescente , Adulto , Alcoolismo/psicologia , Comorbidade , Feminino , Humanos , Coreia (Geográfico) , Masculino , Transtornos Mentais/diagnóstico , Transtornos Mentais/psicologia , Psicometria
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