New directions in thermoresponsive polymers Roy, Debashish; Brooks, William L. A; Sumerlin, Brent S
Chemical Society reviews,
01/2013, Letnik:
42, Številka:
17
Journal Article
Recenzirano
Interest in thermoresponsive polymers has steadily grown over many decades, and a great deal of work has been dedicated to developing temperature sensitive macromolecules that can be crafted into new ...smart materials. However, the overwhelming majority of previously reported temperature-responsive polymers are based on poly(
N
-isopropylacrylamide) (PNIPAM), despite the fact that a wide range of other thermoresponsive polymers have demonstrated similar promise for the preparation of adaptive materials. Herein, we aim to highlight recent results that involve thermoresponsive systems that have not yet been as fully considered. Many of these (co)polymers represent clear opportunities for advancements in emerging biomedical and materials fields due to their increased biocompatibility and tuneable response. By highlighting recent examples of newly developed thermoresponsive polymer systems, we hope to promote the development of new generations of smart materials.
While the majority of reported thermoresponsive polymeric materials have been composed of poly(
N
-isopropylacrylamide), increasing demand for diversity has driven a rapid expansion of structural and chemical variety in the field of temperature-responsive polymers.
There is growing recognition of the problem of male bias in neuroscience research, including in the field of traumatic brain injury (TBI) where fewer women than men are recruited to clinical trials ...and male rodents have predominantly been used as an experimental injury model. Despite TBI being a leading cause of mortality and disability worldwide, sex differences in pathophysiology and recovery are poorly understood, limiting clinical care and successful drug development. Given growing interest in sex as a biological variable affecting injury outcomes and treatment efficacy, there is a clear need to summarize sex differences in TBI. This scoping review presents an overview of current knowledge of sex differences in TBI and a comparison of human and animal studies. We found that overall, human studies report worse outcomes in women than men, whereas animal studies report better outcomes in females than males. However, closer examination shows that multiple factors including injury severity, sample size, and experimental injury model may differentially interact with sex to affect TBI outcomes. Additionally, we explore how sex differences in mitochondrial structure and function might contribute to possible sex differences in TBI outcomes. We propose recommendations for future investigations of sex differences in TBI, which we hope will lead to improved patient management, prognosis, and translation of therapies from bench to bedside.
This report describes the synthesis and characterization of boronate ester-cross-linked hydrogels capable of self-healing behavior at neutral and acidic pH. This atypically wide pH range over which ...healing behavior is observed was achieved through the use of an intramolecular coordinating boronic acid monomer, 2-acrylamidophenylboronic acid (2APBA), where the internal coordination helped to stabilize cross-links formed at acidic and neutral pH. Two different hydrogels were formed from a 2APBA copolymer cross-linked with either poly(vinyl alcohol) or a catechol-functionalized copolymer. The self-healing ability of these hydrogels was characterized through physical testing and rheological studies. Furthermore, the catechol cross-linked hydrogel was shown to be oxygen sensitive, demonstrating reduced self-healing and stress relaxation after partial oxidation. The synthesis of these hydrogels demonstrates a new strategy to produce boronic acid materials capable of self-healing at physiological pH.
There is increasing interest in the role of physical exercise as a therapeutic strategy for individuals with Alzheimer's disease (AD). We assessed the effect of 26 weeks (6 months) of a supervised ...aerobic exercise program on memory, executive function, functional ability and depression in early AD.
This study was a 26-week randomized controlled trial comparing the effects of 150 minutes per week of aerobic exercise vs. non-aerobic stretching and toning control intervention in individuals with early AD. A total of 76 well-characterized older adults with probable AD (mean age 72.9 7.7) were enrolled and 68 participants completed the study. Exercise was conducted with supervision and monitoring by trained exercise specialists. Neuropsychological tests and surveys were conducted at baseline,13, and 26 weeks to assess memory and executive function composite scores, functional ability (Disability Assessment for Dementia), and depressive symptoms (Cornell Scale for Depression in Dementia). Cardiorespiratory fitness testing and brain MRI was performed at baseline and 26 weeks. Aerobic exercise was associated with a modest gain in functional ability (Disability Assessment for Dementia) compared to individuals in the ST group (X2 = 8.2, p = 0.02). There was no clear effect of intervention on other primary outcome measures of Memory, Executive Function, or depressive symptoms. However, secondary analyses revealed that change in cardiorespiratory fitness was positively correlated with change in memory performance and bilateral hippocampal volume.
Aerobic exercise in early AD is associated with benefits in functional ability. Exercise-related gains in cardiorespiratory fitness were associated with improved memory performance and reduced hippocampal atrophy, suggesting cardiorespiratory fitness gains may be important in driving brain benefits.
ClinicalTrials.gov NCT01128361.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Boronic acids have found widespread use in the field of biomaterials, primarily through their ability to bind with biologically relevant 1,2- and 1,3-diols, including saccharides and peptidoglycans, ...or with polyols to prepare hydrogels with dynamic covalent or responsive behavior. Despite a wide range of boronic acid architectures that have been previously considered, there is a need for greater understanding of the structure–reactivity relationships that govern binding affinity to diols. In this study, various boronic acids and other organoboron compounds were investigated to determine their pK a and their binding constants with the biologically relevant diols including sorbitol, fructose, and glucose. Boronic acid pK a values were determined through spectroscopic titration, whereas binding constants were determined by fluorescence spectroscopy during competitive binding studies. Key structure–reactivity relationships clearly indicated that both boronic acid structure and solution pH must be carefully considered. By considering a variety of boronic acids with systematically varied electronics and sterics, these results provide guidance during selection of organoboron compounds in sensing, delivery, and materials chemistry.
Over Here, Over There Warfield, Patrick; Thompson, Brian C; Meinhart, Michelle ...
10/2019
eBook
During the Great War, composers and performers created music that expressed common sentiments like patriotism, grief, and anxiety. Yet music also revealed the complexities of the partnership between ...France, Great Britain, Canada, and the United States. At times, music reaffirmed a commitment to the shared wartime mission. At other times, it reflected conflicting views about the war from one nation to another or within a single nation.Over Here, Over There examines how composition, performance, publication, recording, censorship, and policy shaped the Atlantic allies' musical response to the war. The first section of the collection offers studies of individuals. The second concentrates on communities, whether local, transnational, or on the spectrum in-between. Essay topics range from the sinking of the Lusitania through transformations of the entertainment industry to the influenza pandemic.Contributors: Christina Bashford, William Brooks, Deniz Ertan, Barbara L. Kelly, Kendra Preston Leonard, Gayle Magee, Jeffrey Magee, Michelle Meinhart, Brian C. Thompson, and Patrick Warfield
Development of tau-based therapies for Alzheimer's disease requires an understanding of the timing of disease-related changes in tau. We quantified the phosphorylation state at multiple sites of the ...tau protein in cerebrospinal fluid markers across four decades of disease progression in dominantly inherited Alzheimer's disease. We identified a pattern of tau staging where site-specific phosphorylation changes occur at different periods of disease progression and follow distinct trajectories over time. These tau phosphorylation state changes are uniquely associated with structural, metabolic, neurodegenerative and clinical markers of disease, and some (p-tau217 and p-tau181) begin with the initial increases in aggregate amyloid-β as early as two decades before the development of aggregated tau pathology. Others (p-tau205 and t-tau) increase with atrophy and hypometabolism closer to symptom onset. These findings provide insights into the pathways linking tau, amyloid-β and neurodegeneration, and may facilitate clinical trials of tau-based treatments.
One in four Americans are affected by a disability making people with disabilities (PWD) the largest minority group in the United States. PWD experience a variety of social, economic and structural ...barriers that limit access to medical care and create significant health care disparities. While PWD visit health care providers at a higher frequency than those without disabilities, half of U.S. medical schools lack a disability awareness program, and 58% of medical school deans reported that a curriculum for patients with disabilities was not a high priority. These factors have led to a sense of unpreparedness amongst medical students in providing care for this population. In order to address these deficiencies, a new educational activity, Come Roll with Me (CRWM), was integrated into the Musculoskeletal & Skin course within a Southeastern allopathic medical school in 2021. Authors hypothesized that CRWM would increase disability awareness amongst medical students and enhance attitudes towards interprofessional practice. Come Roll with Me paired PWD, specifically power and manual wheelchair users, with small groups of second‐year medical and Doctor of Physical Therapy (DPT) students for a two‐hour session. Groups rotated through four stations including (1) a self‐propelled wheelchair course within the students’ educational building, (2) a discussion about accessible parking and transportation at the wheelchair users’ vehicles, (3) a skill‐development session on transfers taught by DPT students, and (4) an open dialog regarding barriers to healthcare experienced by PWD. Come Roll with Me was assessed via course evaluations and student reflection essays. Additionally, students were invited to complete the Interprofessional Attitudes Scale (IPAS) before and after the course. The study was approved by the UAB Institutional Review Board. CRWM was the highest rated instructional session in the Musculoskeletal and Skin course with a mean Likert‐scale score of 4.59/5.0 (N=109). Thematic analysis of reflection essays revealed newfound awareness of difficulties navigating a building in a wheelchair and lack of accessibility in doors, bathrooms, etc. Students expressed increased comfort in engaging with PWD and a desire for advocacy on their part. Medical students’ attitudes towards interprofessional collaborative practice improved with significant increases in the mean Teamwork, Roles, Responsibilities (39.3 vs. 42.0) and Interprofessional Biases (8.5 vs. 8.9) IPAS subscales (p<0.01). Come Roll with Me represents a novel interprofessional and patient‐centered method of embedding disability awareness and health care disparities within the preclinical medical curriculum. Integration of the basic sciences with patient encounters and social aspects of medicine are essential in the training of physicians who are competent to care for a diverse patient population.
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