85 research outputs found
Aggregation of Rod−Coil Block Copolymers Containing Rigid Polyampholyte Blocks in Aqueous Solution
Rod−coil block copolymers containing rigid polyampholyte blocks were designed and synthesized by RAFT copolymerization. The rigid polyampholyte blocks were formed by hydrolysis of alternating copolymers of N,N,N‘,N‘-tetraethyl-4,4‘-diaminostilbene with maleic anhydride, and the flexible coil block consists of poly(oligo(ethylene glycol)methacrylate). The rod−coil block copolymers form polyion complex (PIC) aggregates even when the polyampholyte blocks are charge imbalanced. The aggregates did not dissociate upon the addition of high concentrations of NaCl unlike the dissociation of flexible polyampholytes in NaCl solution. These unique solution properties are induced by like-charge attractions of the rigid polyampholytic alternating copolymer chains
Comparison of static balance ability with eyes closed between MCI group and control group.
Comparison of static balance ability with eyes closed between MCI group and control group.</p
COP trajectories of SC and HC for a representative participant.
COP: center of pressure; SC: stood on the soft support surface with eyes closed; HC: stood on the hard support surface with eyes closed; AP: anterior-posterior; ML: medial-lateral.</p
Balance tests on hard support surface.
ObjectiveThis study aimed to assess the static balance ability of the older adults with mild cognitive impairment (MCI) while standing on soft and hard support surfaces.MethodsForty older adults participated in this study (21 in the MCI group and 19 in the control group). Participants were required to perform balance tests under four conditions of standing: standing on a hard support surface with eyes open, standing on a soft support surface with eyes open, standing on a hard support surface with eyes closed, and standing on a soft support surface with eyes closed. Each test was measured in three trials and each trial lasted 30 seconds. Participants were asked to take off their shoes and place their feet in a parallel position with a 20-centimeter distance for bipedal support. The trajectories of the center of pressure (COP) were measured using a Kistler force platform with a frequency of 1000 Hz to assess balance while standing in both groups, with larger COP trajectories indicating poorer static balance in older adults.ResultsWith eyes open, the displacement of COP in the anterior-posterior direction(D-ap) (hard support surface: P = 0.003) and the 95% confidence ellipse area(95%AREA-CE) (soft support surface: P = 0.001, hard support surface: P ml), and 95%AREA-CE of the COP were no significant between-group differences when standing on hard support surfaces. However, the RDIST (P = 0.014), RDISTml (P = 0.014), and 95%AREA-CE (P = 0.001) of the COP in the MCI group on the soft support surfaces were significantly larger than the control group. The 95%AREA-CE (P ml (P ConclusionWith eyes open, the older adults with MCI showed poorer static balance ability compared to the older adults with normal cognition on soft and hard support surfaces. With eyes closed, the older adults with MCI showed poorer static balance on soft support surfaces, but no differences on hard support surfaces compared with the older adults with normal cognition. With eyes open and closed, the older adults with MCI showed poorer static balance on soft support surfaces as compared to hard support surfaces.</div
Balance tests on soft support surface.
ObjectiveThis study aimed to assess the static balance ability of the older adults with mild cognitive impairment (MCI) while standing on soft and hard support surfaces.MethodsForty older adults participated in this study (21 in the MCI group and 19 in the control group). Participants were required to perform balance tests under four conditions of standing: standing on a hard support surface with eyes open, standing on a soft support surface with eyes open, standing on a hard support surface with eyes closed, and standing on a soft support surface with eyes closed. Each test was measured in three trials and each trial lasted 30 seconds. Participants were asked to take off their shoes and place their feet in a parallel position with a 20-centimeter distance for bipedal support. The trajectories of the center of pressure (COP) were measured using a Kistler force platform with a frequency of 1000 Hz to assess balance while standing in both groups, with larger COP trajectories indicating poorer static balance in older adults.ResultsWith eyes open, the displacement of COP in the anterior-posterior direction(D-ap) (hard support surface: P = 0.003) and the 95% confidence ellipse area(95%AREA-CE) (soft support surface: P = 0.001, hard support surface: P ml), and 95%AREA-CE of the COP were no significant between-group differences when standing on hard support surfaces. However, the RDIST (P = 0.014), RDISTml (P = 0.014), and 95%AREA-CE (P = 0.001) of the COP in the MCI group on the soft support surfaces were significantly larger than the control group. The 95%AREA-CE (P ml (P ConclusionWith eyes open, the older adults with MCI showed poorer static balance ability compared to the older adults with normal cognition on soft and hard support surfaces. With eyes closed, the older adults with MCI showed poorer static balance on soft support surfaces, but no differences on hard support surfaces compared with the older adults with normal cognition. With eyes open and closed, the older adults with MCI showed poorer static balance on soft support surfaces as compared to hard support surfaces.</div
DataSheet_1_Association between subclinical hyperthyroidism and a PRKAR1A gene variant in Carney complex patients: A case report and systematic review.doc
Background and ObjectivesIt is currently controversial whether subclinical hyperthyroidism is associated with PRKAR1A gene variants. We describe a man with subclinical hyperthyroidism and a PRKAR1A gene variant who was diagnosed with Carney complex (CNC), and we performed a systematic review of published studies to assess the association between PRKAR1A gene variants and the risk of subclinical hyperthyroidism.Design and MethodsThe PubMed, EMBASE, OVID, Science Direct, and gray literature electronic databases were searched for articles published from January 2002 to May 2021 using predefined keywords and inclusion and exclusion criteria. Data on thyroid function from selected studies were extracted and analyzed.ResultsWe identified a CNC patient with a subclinical hyperthyroidism phenotype combined with multiple components and genetic sequenced data. In a subsequent systematic review, twenty selected studies (14 case studies and 6 series studies) enrolling 23 individuals were included in the final analysis. The patient’s thyroid function data were qualitative in 11 cases and quantitative in 12 cases. The prevalence of subclinical hyperthyroidism in the CNC patients with a PRKAR1A gene variant, including our patient, was markedly higher than that in the normal population (12.5% vs. 2%)ConclusionsThe findings of this systematic review provide helpful evidence that PRKAR1A gene variants and subclinical hyperthyroidism are related and suggest that subclinical hyperthyroidism may be a neglected phenotype of PRKAR1A gene variants and a novel component of CNC patients.Systematic Review Registrationhttps://www.crd.york.ac.uk/PROSPERO, identifier CRD42021197655.</p
Baseline characteristics of participants.
ObjectiveThis study aimed to assess the static balance ability of the older adults with mild cognitive impairment (MCI) while standing on soft and hard support surfaces.MethodsForty older adults participated in this study (21 in the MCI group and 19 in the control group). Participants were required to perform balance tests under four conditions of standing: standing on a hard support surface with eyes open, standing on a soft support surface with eyes open, standing on a hard support surface with eyes closed, and standing on a soft support surface with eyes closed. Each test was measured in three trials and each trial lasted 30 seconds. Participants were asked to take off their shoes and place their feet in a parallel position with a 20-centimeter distance for bipedal support. The trajectories of the center of pressure (COP) were measured using a Kistler force platform with a frequency of 1000 Hz to assess balance while standing in both groups, with larger COP trajectories indicating poorer static balance in older adults.ResultsWith eyes open, the displacement of COP in the anterior-posterior direction(D-ap) (hard support surface: P = 0.003) and the 95% confidence ellipse area(95%AREA-CE) (soft support surface: P = 0.001, hard support surface: P ml), and 95%AREA-CE of the COP were no significant between-group differences when standing on hard support surfaces. However, the RDIST (P = 0.014), RDISTml (P = 0.014), and 95%AREA-CE (P = 0.001) of the COP in the MCI group on the soft support surfaces were significantly larger than the control group. The 95%AREA-CE (P ml (P ConclusionWith eyes open, the older adults with MCI showed poorer static balance ability compared to the older adults with normal cognition on soft and hard support surfaces. With eyes closed, the older adults with MCI showed poorer static balance on soft support surfaces, but no differences on hard support surfaces compared with the older adults with normal cognition. With eyes open and closed, the older adults with MCI showed poorer static balance on soft support surfaces as compared to hard support surfaces.</div
Comparison of static balance ability with eyes open between MCI group and control group.
Comparison of static balance ability with eyes open between MCI group and control group.</p
Table_1_Tai Chi practice enables prefrontal cortex bilateral activation and gait performance prioritization during dual-task negotiating obstacle in older adults.XLS
BackgroundWith aging, the cognitive function of the prefrontal cortex (PFC) declined, postural control weakened, and fall risk increased. As a mind–body exercise, regular Tai Chi practice could improve postural control and effectively prevent falls; however, underlying brain mechanisms remained unclear, which were shed light on by analyzing the effect of Tai Chi on the PFC in older adults by means of functional near-infrared spectroscopy (fNIRS).Methods36 healthy older adults without Tai Chi experience were divided randomly into Tai Chi group and Control group. The experiment was conducted four times per week for 16 weeks; 27 participants remained and completed the experiment. Negotiating obstacle task (NOT) and negotiating obstacle with cognitive task (NOCT) were performed pre- and post-intervention, and Brodmann area 10 (BA10) was detected using fNIRS for hemodynamic response. A three-dimensional motion capture system measured walking speed.ResultsAfter intervention in the Tai Chi group under NOCT, the HbO2 concentration change value (ΔHbO2) in BA10 was significantly greater (right BA10: p = 0.002, left BA10: p = 0.001), walking speed was significantly faster (p = 0.040), and dual-task cost was significantly lower than pre-intervention (p = 0.047). ΔHbO2 in BA10 under NOCT was negatively correlated with dual-task cost (right BA10: r = −0.443, p = 0.021, left BA10: r = −0.448, p = 0.019). There were strong negative correlations between ΔHbO2 and ΔHbR under NOCT either pre-intervention (left PFC r = −0.841, p ConclusionTai Chi practice might increase the cognitive resources in older adults through the PFC bilateral activation to prioritize gait performance during negotiating obstacles under a dual-task condition.</p
Sterically Crowded Anionic Polyelectrolytes with Tunable Charge Densities Based on Stilbene-Containing Copolymers
Anionic polyelectrolytes with various charge densities
and a well-defined
chain architecture have great industrial and fundamental importance.
In this article, we describe the synthesis and characterization of
new sterically crowded conformationally constrained anionic polyelectrolytes
with tunable charge densities based on highly functionalized stilbene-maleic
anhydride/maleimide comonomers. Polyelectrolyte precursors with <i>tert</i>-butyl carboxylate protecting groups are first prepared
by radical polymerization and readily characterized by <sup>1</sup>H NMR, SEC, TGA, and DSC without the complications normally arising
with charged macromolecules. The precursors are converted into their
corresponding deblocked forms by simply reacting with trifluoroacetic
acid to deprotect the <i>tert</i>-butyl group and then neutralized
in basic aqueous solutions to yield anionic polyelectrolytes
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