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1.
Matern Child Health J ; 28(5): 820-827, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-37906401

RESUMO

OBJECTIVES: Studies suggests that pregnancy can alter the maternal neurological function of the brain (i.e., result in cognitive decline) in a way that remains prevalent well into middle and older adulthood. However, little research has explored these changes and how they might affect behavioral health outcomes, such as substance use and depression. METHODS: We merged data from the 2016, 2017, and 2018 Behavioral Risk Factor Surveillance System (BRFSS) surveys, with a final analytic sample of 1330 female participants (649 participants were mothers). Chi-square tests or t-tests were used to examine differences in demographic and health characteristics of the sample by subjective cognitive decline (SCD) status. To test the study hypotheses, three generalized linear mixed models were estimated with a logit link. RESULTS: SCD was not associated with alcohol misuse among mothers (aOR = 0.27, p = 0.23). Mothers with SCD were more likely to smoke (aOR = 3.33, p = 0.01) and experience mental distress (aOR = 6.59, p < 0.001) than those without SCD. CONCLUSION: Interventions aimed at supporting mothers should consider how existing mental health and tobacco cessation programs can be adapted to better serve this population and should aim to identify those that may have early signs of early signs of neurodegenerative conditions.


Assuntos
Disfunção Cognitiva , Gravidez , Humanos , Feminino , Idoso , Disfunção Cognitiva/epidemiologia , Disfunção Cognitiva/psicologia , Mães , Sistema de Vigilância de Fator de Risco Comportamental , Inquéritos e Questionários , Avaliação de Resultados em Cuidados de Saúde
2.
J Am Chem Soc ; 143(29): 11080-11087, 2021 07 28.
Artigo em Inglês | MEDLINE | ID: mdl-34283574

RESUMO

We report on the detection and stabilization of a previously unknown two-dimensional (2D) pseudopolymorph of an alkoxy isophthalic acid using lateral nanoconfinement. The self-assembled molecular networks formed by the isophthalic acid derivative were studied at the interface between covalently modified graphite and an organic solvent. When self-assembled on graphite with moderate surface coverage of covalently bound aryl groups, a previously unknown metastable pseudopolymorph was detected. This pseudopolymorph, which was presumably "trapped" in between the surface bound aryl groups, underwent a time-dependent phase transition to the stable polymorph typically observed on pristine graphite. The stabilization of the pseudopolymorph was then achieved by using an alternative nanoconfinement strategy, where the domains of the pseudopolymorph could be formed and stabilized by restricting the self-assembly in nanometer-sized shallow compartments produced by STM-based nanolithography carried out on a graphite surface with a high density of covalently bound aryl groups. These experimental results are supported by molecular mechanics and molecular dynamics simulations, which not only provide important insight into the relative stabilities of the different structures, but also shed light onto the mechanism of the formation and stabilization of the pseudopolymorph under nanoscopic lateral confinement.


Assuntos
Grafite/química , Nanoestruturas/química , Ácidos Ftálicos/análise , Simulação de Dinâmica Molecular , Estrutura Molecular
3.
J Am Chem Soc ; 142(16): 7699-7708, 2020 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-32212655

RESUMO

Controlled covalent functionalization of graphitic surfaces with molecular scale precision is crucial for tailored modulation of the chemical and physical properties of carbon materials. We herein present that porous self-assembled molecular networks (SAMNs) act as nanometer scale template for the covalent electrochemical functionalization of graphite using an aryldiazonium salt. Hexagonally aligned achiral grafted species with lateral periodicity of 2.3, 2.7, and 3.0 nm were achieved utilizing SAMNs having different pore-to-pore distances. The unit cell vectors of the grafted pattern match those of the SAMN. After the covalent grafting, the template SAMNs can be removed by simple washing with a common organic solvent. We briefly discuss the mechanism of the observed pattern transfer. The unit cell vectors of the grafted pattern align along nonsymmetry axes of graphite, leading to mirror image grafted domains, in accordance with the domain-specific chirality of the template. In the case in which a homochiral building block is used for SAMN formation, one of the 2D mirror image grafted patterns is canceled. This is the first example of a nearly crystalline one-sided or supratopic covalent chemical functionalization. In addition, the positional control imposed by the SAMN renders the functionalized surface (homo)chiral reaching a novel level of control for the functionalization of carbon surfaces, including surface-supported graphene.

4.
Langmuir ; 35(6): 2089-2098, 2019 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-30626188

RESUMO

Grafting of aryl radicals generated by electrochemical reduction of aryldiazonium salts has been extensively studied on various surfaces. However, there exists two unclear aspects; the first one is the generality of the blocking ability of simple functional groups toward multilayer growth, and the second one is the electronic impact of substituent groups of aryl radicals on grafting efficiency. To address these aspects, we have studied the electrochemical functionalization of graphite using aryldiazonium salts having electron-donating or electron-withdrawing groups at the 3,4,5-positions. Atomic force microscopy investigation of the functionalized surfaces revealed the formation of monolayers for all aryldiazonium salts, and thus, nitro, carboxy, ester, methyl, and methoxy groups at the 3,4,5-positions of the benzene ring suppress polyaryl growth. The degree of grafting estimated by scanning tunneling microscopy imaging and Raman spectroscopy of the functionalized surfaces depends on the electronic state of the aryl radicals, in which the radicals with electron-donating groups show a high degree of functionalization, whereas those with electron-withdrawing groups exhibit a low degree of functionalization. We discuss several possibilities that affect grafting density. Though there are several factors, we hypothesize that one factor to explain the observed reactivity trend is the electronic property of the aryl radicals, namely, the relative position of the singly occupied molecular orbital energy levels of the aryl radicals with respect to the graphite Fermi energy level.

5.
J Am Chem Soc ; 140(37): 11565-11568, 2018 09 19.
Artigo em Inglês | MEDLINE | ID: mdl-30165736

RESUMO

Nanocorrals created by scanning probe lithography on covalently modified graphite surfaces are used to induce a chiral bias in the enantiomorphic assembly of a prochiral molecule at the liquid/graphite interface. By controlling the orientation of the nanocorrals with respect to the underlying graphite surface, the nanocorral handedness can be freely chosen and thus a chiral bias in molecular self-assembly is created at an achiral surface solely by the scanning probe lithography process.

6.
Phys Chem Chem Phys ; 20(43): 27482-27489, 2018 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-30358776

RESUMO

Self-assembly of an alkylated diacetylene derivative is spatially confined via in situ scanning tunneling microscopy (STM) nanoshaving inside covalently modified highly ordered pyrolytic graphite (CM-HOPG). In contrast to unconstrained self-assembly that occurs randomly along three thermodynamically equivalent surface lattice directions, spatially confined assemblies are shown to form along chosen substrate orientations. Experimental statistics suggest two mechanisms for breaking the rotational degeneracy of the surface. First, the assembly orientation is biased via lateral confinement inside nanocorrals that do not match the substrate symmetry. Second, an interaction between the assembling molecules and the STM tip during nanoshaving guides 2D crystal nucleation and growth. The results presented here open new possibilities to regulate and orient self-assembled architectures via in situ nanomechanical manipulation techniques and provide mechanistic insights into the process.

7.
J Am Chem Soc ; 139(17): 6226-6233, 2017 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-28437103

RESUMO

The hierarchical assembly of colored cationic molecules with receptor-modified counteranions can be used to control optical properties in materials. However, our knowledge of when the optical properties emerge in the hierarchical organization and the variety of cation-anion salts that are available to create these materials is limited. In this work, we extend the salts from small halides to large inorganic anions and determine how the structure coevolves with the emission properties using solution assemblies. We study the chromogenic trioxatriangulenium (TOTA+) cation and its coassembly with cyanostar (CS) macrocycles selected to modify tetrafluoroborate (BF4-) counteranions through formation of 2:1 sandwich complexes. In the solid state, the TOTA+ cation stacks in an alternating manner with the sandwich complexes producing new red-shifted emission and absorption bands. Critical to assigning the structural origin of the new optical features across the four levels of organization (1° → 4°) is the selection of specific solvents to produce and characterize different assemblies present in the hierarchical structure. A key species is the electrostatically stabilized ion pair between the TOTA+ cation and sandwich complex. The red-shifted features only emerge when the ion pairs oligomerize together into larger (TOTA·[CS2BF4])n assemblies. New electronic states emerge as a result of multiple copies of the TOTA+ making π-contact with cyanostar-anion complexes. Our findings and the ease with which the materials can be prepared as crystals and films by mixing the salt with a receptor provide a strong platform for the de novo design of new optical materials.

8.
Faraday Discuss ; 204: 159-172, 2017 10 26.
Artigo em Inglês | MEDLINE | ID: mdl-28771267

RESUMO

The interaction and mobility of ions in complex systems are fundamental to processes throughout chemistry, biology, and physics. However, nanoscale characterization of ion stability and migration remains poorly understood. Here, we examine ion movements to and from physisorbed molecular receptors at solution-graphite interfaces by developing a theoretical model alongside experimental scanning tunneling microscopy (STM) results. The model includes van der Waals forces and electrostatic interactions originating from the surface, tip, and physisorbed receptors, as well as a tip-surface electric field arising from the STM bias voltage (Vb). Our model reveals how both the electric field and tip-surface distance, dtip, can influence anion stability at the receptor binding sites on the surface or at the STM tip, as well as the size of the barrier for anion transitions between those locations. These predictions agree well with prior and new STM results from the interactions of anions with aryl-triazole receptors that order into functional monolayers on graphite. Scanning produces clear resolution at large magnitude negative surface biases (-0.8 V) while resolution degrades at small negative surface biases (-0.4 V). The loss in resolution arises from frequent tip retractions assigned to anion migration within the tip-surface tunneling region. This experimental evidence in combination with support from the model demonstrates a local voltage gating of anions with the STM tip inside physisorbed receptors. This generalized model and experimental evidence may help to provide a basis to understand the nanoscale details of related chemical transformations and their underlying thermodynamic and kinetic preferences.

9.
Nanotechnology ; 28(33): 335706, 2017 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-28656908

RESUMO

We investigated the topological insulator (TI) Bi2Te3 in four different environments (ambient, ultra-high vacuum (UHV), nitrogen gas and organic solvent environment) using scanning probe microscopy (SPM) techniques. Upon prolonged exposure to ambient conditions and organic solvent environments the cleaved surface of the pristine Bi2Te3 is observed to be strongly modified during SPM measurements, while imaging of freshly cleaved Bi2Te3 in UHV and nitrogen gas shows considerably less changes of the Bi2Te3 surface. We conclude that the reduced surface stability upon exposure to ambient conditions is triggered by adsorption of molecular species from ambient, including H2O, CO2, etc which is verified by Auger electron spectroscopy. Our findings of the drastic impact of exposure to ambient on the Bi2Te3 surface are crucial for further in-depth studies of the intrinsic properties of the TI Bi2Te3 and for potential applications that include room temperature TI based devices operated under ambient conditions.

10.
Chemistry ; 22(2): 560-9, 2016 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-26593327

RESUMO

Programming the synthesis and self-assembly of molecules is a compelling strategy for the bottom-up fabrication of ordered materials. To this end, shape-persistent macrocycles were designed with alternating carbazoles and triazoles to program a one-pot synthesis and to bind large anions. The macrocycles bind anions that were once considered too weak to be coordinated, such as PF6 (-) , with surprisingly high affinities (ß2 =10(11) M(-2) in 80:20 chloroform/methanol) and positive cooperativity, α=(4 K2 /K1 )=1200. We also discovered that the macrocycles assemble into ultrathin films of hierarchically ordered tubes on graphite surfaces. The remarkable surface-templated self-assembly properties, as was observed by using scanning tunneling microscopy, are attributed to the complementary pairing of alternating triazoles and carbazoles inscribed into both the co-facial and edge-sharing seams that exist between shape-persistent macrocycles. The multilayer assembly is also consistent with the high degree of molecular self-association observed in solution, with self-association constants of K=300 000 M(-1) (chloroform/methanol 80:20). Scanning tunneling microscopy data also showed that surface assemblies readily sequester iodide anions from solution, modulating their assembly. This multifunctional macrocycle provides a foundation for materials composed of hierarchically organized and nanotubular self-assemblies.

11.
J Chem Phys ; 142(10): 101914, 2015 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-25770503

RESUMO

One of the benefits of supramolecular assemblies that form at dynamic interfaces is the opportunity to develop condensed phase systems that respond to environmental stimuli. A prerequisite of this responsive behavior is that the supramolecular system be designed to sit very near the stability of two or more crystal structures. We have created such a bi-phasic system with aryl-triazole oligomers by investigating how phase morphology is controlled by the interplay between interactions that involve the oligomer's dipolar cores (Δµ = 3.5 debye), van der Waals contacts of their pendant alkyl chains (C4-C18), and close-contact hydrogen bonding. Scanning tunneling microscopy experiments conducted at the solution-graphite interface allow sub-molecular resolution of the ordered monolayers to unambiguously determine the packing and structure of two principle phases, α and ß. The system is balanced very near the edge of phase stability, evidenced by co-existent phases present over short time frames and by the changes in preference between the two 2D supramolecular assemblies that occur with small modifications to the molecular structure. We demonstrate that the bi-phasic behavior can be understood as a balance between electrostatic interactions and van der Waals contacts, two variables within a larger parameter space, allowing synthetic design to move this solution-surface system across the stability boundary of different condensed-phase structures. These findings are a foundation for the development of environmentally responsive 2D supramolecular arrays.


Assuntos
Nanoestruturas/química , Ligação de Hidrogênio , Estrutura Molecular , Fenômenos de Química Orgânica , Transição de Fase , Eletricidade Estática
12.
J Am Acad Orthop Surg ; 22(4): 203-13, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24668350

RESUMO

Lumbar degenerative spondylolisthesis (DS) is a common cause of low back pain, radiculopathy, and/or neurogenic claudication. Treatment begins with a trial of nonsurgical methods, including physical therapy, NSAIDs, and epidural corticosteroid injections. Surgical treatment with decompression and fusion is recommended for patients who do not respond to this initial regimen. Although much has been published in the past two decades on the surgical management of DS, the optimal method remains controversial. Interbody fusion may improve arthrodesis rates and can be performed via numerous surgical approaches. Minimally invasive techniques continue to be developed. Particular attention to surgical management of DS in the elderly is warranted given the increasing numbers of elderly persons. Healthcare utilization in the future must take into account evidence-based medicine that establishes clinically effective practices while simultaneously being cost effective.


Assuntos
Descompressão Cirúrgica , Vértebras Lombares , Fusão Vertebral , Espondilolistese/cirurgia , Análise Custo-Benefício , Humanos , Radiografia , Estenose Espinal/etiologia , Estenose Espinal/cirurgia , Espondilolistese/complicações , Espondilolistese/diagnóstico por imagem , Espondilolistese/economia
13.
Int J Spine Surg ; 18(1): 9-23, 2024 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-38050030

RESUMO

BACKGROUND: Accurate identification of pain generators in the context of low back and spine-related pain is crucial for effective treatment. This review aims to evaluate the potential usefulness of single photon emission computed tomography with computed tomography (SPECT/CT) as an imaging modality in guiding clinical decision-making. METHODS: A broad scoping literature review was conducted to identify relevant studies evaluating the use of SPECT/CT in patients with spine-related pain. Studies were reviewed for their methodology and results. RESULTS: SPECT/CT appears to have advantages over traditional modalities, such as magnetic resonance imaging and CT, in certain clinical scenarios. It may offer additional information to clinicians and improve the specificity of diagnosis. However, further studies are needed to fully assess its diagnostic accuracy and clinical utility. CONCLUSIONS: SPECT/CT is a promising imaging modality in the evaluation of low back pain, particularly in cases where magnetic resonance imaging and CT are inconclusive or equivocal. However, the current level of evidence is limited, and additional research is needed to determine its overall clinical relevance. CLINICAL RELEVANCE: SPECT/CT may have a significant impact on clinical decision-making, particularly in cases in which traditional imaging modalities fail to provide a clear diagnosis. Its ability to improve specificity could lead to more targeted and effective treatment for patients with spinal pathology.

14.
Artigo em Inglês | MEDLINE | ID: mdl-37569024

RESUMO

To effectively treat patients and minimize viral exposure, oncology nurses and radiology departments during COVID-19 had to re-examine the ability to offer palliative radiation treatments to people with metastatic bone cancer. Decreasing potential exposure to the virus resulted in extra measures to keep patients and personnel safe. Limiting radiotherapy treatments, social distancing, and limiting caregivers were a few of the ways that oncology patients were impacted by the pandemic. Hypofractionated radiation therapy (HFRT), or the delivery of fewer higher-dose treatments, was a method of providing care but also limiting exposure to infection for immunocompromised patients as well as healthcare staff. As oncology radiation centers measure the impact of patient care during the pandemic, a trend toward HFRT may occur in treating the painful symptoms of bone cancer. In anticipation that HFRT may be increasingly used in patient treatment plans, oncology nurses should consider patient perspectives and outcomes from the pandemic to further determine how to manage future trends in giving personalized care, and supportive care.


Assuntos
Neoplasias Ósseas , COVID-19 , Cuidados de Enfermagem , Radioterapia (Especialidade) , Humanos , Radioterapia (Especialidade)/métodos , Oncologia
18.
Eur Spine J ; 21(12): 2659-63, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22581258

RESUMO

PURPOSE: To investigate the effect of omega-3 fatty-acid supplements (n-3FA) on bleeding during posterior spinal arthrodesis. METHODS: We reviewed all one- or two-level posterolateral lumbar decompression/fusions with or without interbody fusion by five surgeons within 3 years. Patients taking n-3FA preoperatively were matched 1:2 with controls based on procedure, surgeon and operative time. Patients with abnormal coagulation parameters, known bleeding disorders or other medications that could affect surgical blood loss were excluded. RESULTS: Twenty-eight patients met inclusion criteria. The n-3FA and control groups were similar with respect to gender, age, body mass index, operative time, and preoperative use of non-steroidal anti-inflammatory drugs. The n-3FAs were stopped an average of 5.2 days before surgery (range 1-10). Mean estimated blood loss (EBL) was 697 ml in the n-3FA group and 771 ml in the control group (p = 0.36). Mean transfused volume of Cell Saver (CS) was 282 ml in the n-3FA group and 321 ml in the control group (p = 0.30). A post hoc power analysis showed that the study was powered to detect a minimum difference of 105 ml for EBL and 50 ml for CS. The multivariate generalized estimating equation did not show a significant difference between groups for EBL or CS (p = 0.35 and p = 0.29, respectively). Secondary outcomes including drop in postoperative hemoglobin, transfusion requirement, complications and surgical drain output were similar between the two groups. CONCLUSIONS: The n-3FA use did not contribute to higher perioperative blood loss during spinal arthrodesis.


Assuntos
Suplementos Nutricionais/efeitos adversos , Ácidos Graxos Ômega-3/efeitos adversos , Hemorragia Pós-Operatória , Fusão Vertebral , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
19.
Radiol Technol ; 93(3): 303CT-321CT, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-35017276

RESUMO

Lung and bronchus cancers account for almost 13% of new cancer cases and are responsible for approximately 23% of cancer deaths in the United States. Lung cancer has a poor prognosis, primarily because of advanced disease stage at initial diagnosis. An estimated 80% to 90% of lung cancer deaths are caused by smoking tobacco, and although smoking rates have decreased in recent decades, millions of people are eligible for lung cancer screening each year because they smoke. Screening high-risk populations for lung cancer using low-dose computed tomography has resulted in increased lung cancer survival rates because diagnosis is possible at an earlier disease stage.


Assuntos
Detecção Precoce de Câncer , Neoplasias Pulmonares , Detecção Precoce de Câncer/métodos , Humanos , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/etiologia , Programas de Rastreamento , Fumar/efeitos adversos , Tomografia Computadorizada por Raios X/métodos , Estados Unidos/epidemiologia
20.
Clin Case Rep ; 10(12): e6712, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36514464

RESUMO

In this report, we present a rare case of a 17-year-old male patient with metastatic mesenchymal chondrosarcoma (MCS) managed with nonsurgical treatment who subsequently demonstrated a favorable response to concurrent chemotherapy and radiation therapy, followed with pazopanib target therapy. Further study regarding nonoperative care for metastatic MCS of spine is warranted.

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