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2.
Angew Chem Int Ed Engl ; 59(44): 19561-19569, 2020 Oct 26.
Article in English | MEDLINE | ID: mdl-32648629

ABSTRACT

Porosity and acidity are influential properties in the rational design of solid-acid catalysts. Probing the physicochemical characteristics of an acidic zeotype framework at the molecular level can provide valuable insights in understanding intrinsic reaction pathways, for affording structure-activity relationships. Herein, we employ a variety of probe-based techniques (including positron annihilation lifetime spectroscopy (PALS), FTIR and solid-state NMR spectroscopy) to demonstrate how a hierarchical design strategy for a faujasitic (FAU) zeotype (synthesized for the first time, via a soft-templating approach, with high phase-purity) can be used to simultaneously modify the porosity and modulate the acidity for an industrially significant catalytic process (Beckmann rearrangement). Detailed characterization of hierarchically porous (HP) SAPO-37 reveals enhanced mass-transport characteristics and moderated acidity, which leads to superior catalytic performance and increased resistance to deactivation by coking, compared to its microporous counterpart, further vindicating the interplay between porosity and moderated acidity.

3.
Chem Commun (Camb) ; 55(27): 3868-3871, 2019 Mar 28.
Article in English | MEDLINE | ID: mdl-30801075

ABSTRACT

A facile mechanochemical method was employed to accomplish one-pot encapsulation of anti-cancer drug 5-fluorouracil (5-FU as guest) in a metal-organic framework (HKUST-1 as host). Vibrational spectroscopy via inelastic neutron scattering was applied to probe guest-host interactions arising from nanoscale confinement. We compare 5-FU@HKUST-1 derived from in situ and ex situ encapsulation.


Subject(s)
Antineoplastic Agents/chemistry , Drug Carriers/chemistry , Fluorouracil/chemistry , Metal-Organic Frameworks/chemistry , Organometallic Compounds/chemistry , Porosity , Vibration
4.
J Aging Phys Act ; 27(5): 663­669, 2019 09 01.
Article in English | MEDLINE | ID: mdl-30676192

ABSTRACT

Testing balance and fall risk with older adults of varying abilities is of increasing importance. The primary aim of this study was to evaluate the validity of the lower quarter Y-balance test (YBT-LQ) in older adults. A secondary aim was to provide estimates of reliability with this population. A total of 30 male (n = 15) and female (n = 15) subjects (66.8 ± 6.5 years) performed the YBT-LQ, 30-s chair stand test, 8-foot up and go test, timed up and go test, single-leg stance, and Activities-Specific Balance Confidence Scale questionnaire. The YBT-LQ was performed on two separate occasions by two investigators in random order. YBT-LQ was significantly correlated with age (p < .01), timed up and go test (p = .003), 8-foot up and go test (p < .001), 30-s chair stand test (p < .001), Activities-Specific Balance Confidence Scale (p = .002), and single-leg stance (p = .005) performance. The intraclass correlation coefficient(3,1) score for the reliability of the YBT-LQ was .95 (95% confidence interval [.89, .97]). The YBT-LQ appears to be a valid and reliable assessment to use with older adults.


Subject(s)
Postural Balance , Aged , Aged, 80 and over , Cross-Sectional Studies , Diagnostic Techniques and Procedures , Female , Humans , Male , Middle Aged , Reproducibility of Results
5.
J Am Chem Soc ; 136(38): 13082-5, 2014 Sep 24.
Article in English | MEDLINE | ID: mdl-24972299

ABSTRACT

This paper presents a new type of process for the cracking of ammonia (NH3) that is an alternative to the use of rare or transition metal catalysts. Effecting the decomposition of NH3 using the concurrent stoichiometric decomposition and regeneration of sodium amide (NaNH2) via sodium metal (Na), this represents a significant departure in reaction mechanism compared with traditional surface catalysts. In variable-temperature NH3 decomposition experiments, using a simple flow reactor, the Na/NaNH2 system shows superior performance to supported nickel and ruthenium catalysts, reaching 99.2% decomposition efficiency with 0.5 g of NaNH2 in a 60 sccm NH3 flow at 530 °C. As an abundant and inexpensive material, the development of NaNH2-based NH3 cracking systems may promote the utilization of NH3 for sustainable energy storage purposes.


Subject(s)
Amides/chemistry , Ammonia/chemistry , Hydrogen/chemistry , Sodium/chemistry , Catalysis , Models, Molecular , Nickel/chemistry , Ruthenium/chemistry , Temperature
6.
Bioorg Med Chem Lett ; 22(19): 6144-7, 2012 Oct 01.
Article in English | MEDLINE | ID: mdl-22944119

ABSTRACT

The synthesis of an unnatural polyprenylated acylphloroglucinol (PPAP), regioisomeric with nemorosone and clusianone, has been accomplished. The separated enantiomers of this new PPAP, along with those of nemorosone and clusianone, have been screened for activity against HeLa (cervix carcinoma), MIA-PaCa-2 (pancreatic carcinoma), and MCF7 (mamma carcinoma) cancer cell lines. All of the isomers examined gave surprisingly similar results in the screens.


Subject(s)
Antineoplastic Agents/pharmacology , Benzophenones/pharmacology , Bridged Bicyclo Compounds/pharmacology , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/chemistry , Benzophenones/chemical synthesis , Benzophenones/chemistry , Benzoquinones , Bridged Bicyclo Compounds/chemical synthesis , Bridged Bicyclo Compounds/chemistry , Cell Line, Tumor , Dose-Response Relationship, Drug , Drug Screening Assays, Antitumor , HeLa Cells , Humans , MCF-7 Cells , Molecular Conformation , Stereoisomerism , Structure-Activity Relationship
7.
J Strength Cond Res ; 25(5): 1465-9, 2011 May.
Article in English | MEDLINE | ID: mdl-21522078

ABSTRACT

Measurement of graded exercise test duration is clinically important and can be assessed by maximal graded exercise testing. Yet, limitations of maximal graded exercise testing exist. An alternative to maximal graded exercise testing is submaximal graded exercise testing. However, no studies have investigated the reliability of a submaximal graded exercise test in the measurement of graded exercise test duration. The purpose of this study was to determine the test-retest reliability and minimal detectable change (MDC) of a novel submaximal graded exercise test in the measurement of graded exercise test duration. Fifteen people (4 men, 11 women) with a mean age of 26.20 years (SD = 9.04) participated in this study. A novel submaximal graded exercise test was used to measure graded exercise test duration for each participant. Endpoints of the test were either 85% of age-predicted maximum heart rate or voluntarily stopping the test, whichever endpoint occurred first. Heart rate and graded exercise test duration were constantly measured throughout the test. Graded exercise test duration was defined as the total duration (minutes) of the test. For all participants, the submaximal graded exercise test was conducted at baseline and 48-72 hours thereafter. The intraclass correlation coefficient for the test-retest reliability of the test in determining graded exercise test duration was 0.94 (95% CI = 0.83-0.98). The MDC of the test in the measurement of graded exercise test duration was 0.86 minutes. The results suggest that clinicians can use this novel submaximal graded exercise test to reliably measure graded exercise test duration with a measurement error, as expressed by the MDC, of 0.86 minutes.


Subject(s)
Exercise Test/methods , Exercise Tolerance/physiology , Adult , Confidence Intervals , Female , Heart Rate/physiology , Humans , Male , Oxygen Consumption/physiology , Reproducibility of Results , Risk Factors , Sampling Studies , Sensitivity and Specificity , Time Factors , Young Adult
9.
Psychiatry Res ; 172(3): 235-41, 2009 Jun 30.
Article in English | MEDLINE | ID: mdl-19398308

ABSTRACT

We applied a covariance-based multivariate analysis to functional magnetic resonance imaging (fMRI) data to investigate abnormalities in working memory (WM) systems in patients with post-traumatic stress disorder (PTSD). Patients (n=13) and matched controls (n=12) were scanned with fMRI while updating or maintaining trauma-neutral verbal stimuli in WM. A multivariate statistical analysis was used to investigate large-scale brain networks associated with these experimental tasks. For the control group, the first network reflected brain activity associated with WM updating and principally involved bilateral prefrontal and bilateral parietal cortex. Controls' second network was associated with WM maintenance and involved regions typically activated during storage and rehearsal of verbal material, including lateral premotor and inferior parietal cortex. In contrast, PTSD patients appeared to activate a single fronto-parietal network for both updating and maintenance tasks. This is indicative of abnormally elevated activity during WM maintenance and suggests inefficient allocation of resources for differential task demands. A second network in PTSD, which was not activated in controls, showed regions differentially activated between WM tasks, including the anterior cingulate, medial prefrontal cortex, fusiform and supplementary motor area. These activations may be linked to hyperarousal and abnormal reactivity, which are characteristic of PTSD.


Subject(s)
Brain/physiopathology , Magnetic Resonance Imaging , Memory, Short-Term , Nerve Net/physiopathology , Stress Disorders, Post-Traumatic/physiopathology , Stress Disorders, Post-Traumatic/psychology , Adult , Case-Control Studies , Female , Humans , Image Processing, Computer-Assisted , Male , Middle Aged , Motor Cortex/physiopathology , Multivariate Analysis , Parietal Lobe/physiopathology , Prefrontal Cortex/physiopathology , Stress Disorders, Post-Traumatic/diagnosis , Verbal Learning
10.
Reproduction ; 137(3): 567-82, 2009 Mar.
Article in English | MEDLINE | ID: mdl-19060096

ABSTRACT

The integrity of the fetal-maternal interface is critical for proper fetal nourishment during pregnancy. Integrins are important adhesion molecules present at the interface during implantation; however, in vivo evidence for integrin activation and focal adhesion formation at the maternal-conceptus interface is limited. We hypothesized that focal adhesion assembly in uterine luminal epithelium (LE) and conceptus trophectoderm (Tr) results from integrin binding of extracellular matrix (ECM) at this interface to provide increased tensile forces and signaling to coordinate utero-placental development. An ovine model of unilateral pregnancy was used to evaluate mechanotransduction events leading to focal adhesion assembly at the maternal-conceptus interface and within the uterine wall. Animals were hysterectomized on days 40, 80, or 120 of pregnancy, and uteri immunostained for integrins (ITGAV, ITGA4, ITGA5, ITGB1, ITGB3, and ITGB5), ECM proteins (SPP1, LGALS15, fibronectin (FN), and vitronectin (VTN)), cytoskeletal molecules (ACTN and TLN1), and a signal generator (PTK2). Focal adhesion assembly in myometrium and stroma was also studied to provide a frame of reference for mechanical stretch of the uterine wall. Large focal adhesions containing aggregates of ITGAV, ITGA4, ITGA5, ITGB1, ITGB5, ACTN, and PTK2 were detected in interplacentomal uterine LE and Tr of gravid but not non-gravid uterine horns and increased during pregnancy. SPP1 and LGALS15, but not FN or VTN, were present along LE and Tr interfaces in both uterine horns. These data support the idea that focal adhesion assembly at the maternal-conceptus interface reflects adaptation to increasing forces caused by the growing fetus. Cooperative binding of multiple integrins to SPP1 deposited at the maternal-conceptus interface forms an adhesive mosaic to maintain a tight connection between uterine and placental surfaces along regions of epitheliochorial placentation in sheep.


Subject(s)
Embryo Implantation/physiology , Focal Adhesions/physiology , Trophoblasts/metabolism , Uterus/metabolism , Animals , Cytoskeletal Proteins/analysis , Extracellular Matrix Proteins/analysis , Female , Fluorescent Antibody Technique , Integrins/analysis , Mechanotransduction, Cellular/physiology , Models, Animal , Pregnancy , Sheep
11.
Reproduction ; 131(4): 751-61, 2006 Apr.
Article in English | MEDLINE | ID: mdl-16595726

ABSTRACT

Glycosylation dependent cell adhesion molecule 1 (GlyCAM-1), a mucin component of sheep histotroph produced by glandular epithelium (GE) during early pregnancy, is hypothesized to function in implantation. However, GlyCAM-1 is present in uterine tissues subsequent to implantation suggesting additional functions of this l-selectin-binding ligand. This study focused on uterine GlyCAM-1 expression during placentome development in sheep. Western blot analysis of day 50 pregnant sheep identified 45, 40, and 25 kDa bands in interplacentomal endometrium, 40 and 25 kDa bands in placentomes, and 80 and 40 kDa bands in chorioallantois. The GlyCAM-1 proteins in interplacentomal regions were comparable to those detected in day 15-19 pregnant sheep, however, the 80 kDa form was unique to chorioallantois, and the absence of the 45 kDa GlyCAM-1 in placentomes indicated differences between interplacentomal and placentomal endometrium. Immunofluorescence identified GlyCAM-1 in lumenal epithelium (LE), stromal fibroblasts, and vascular smooth muscle cells. To better define its cellular distribution, GlyCAM-1 was co-localized with either epithelium-specific cytokeratin, smooth muscle-specific alpha-smooth muscle actin (alpha SMA), or stromal-specific vimentin. In interplacentomal endometrium, GlyCAM-1 co-localized with cytokeratin in LE but not in GE. GlyCAM-1 did not co-localize with alpha SMA, and was localized in the extracellular matrix of vimentin-positive stroma. In placentomes, GlyCAM-1 did not co-localize with cytokeratin, but did co-localize with alpha SMA and vimentin. Thus, in contrast to interplacentomal regions, GlyCAM-1 in placentomes was predominantly localized in vasculature rather than epithelial cells. Further, leukocytes expressing L-selectin were localized to the endothelial surface of GlyCAM-1-expressing vessels within placentomes. These data suggest that GlyCAM-1 assumes distinct functions in compartment-specific regions of the sheep uterus.


Subject(s)
Endometrium/chemistry , L-Selectin/analysis , Mucins/analysis , Placenta/chemistry , Pregnancy, Animal/metabolism , Sheep/metabolism , Actins/analysis , Animals , Blotting, Western/methods , Female , Fluorescent Antibody Technique , Keratins/analysis , Pregnancy
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