bluuebunny/crossref_metadata_2025_split huggingface dataset:
Racemization hypothesis of neurodegeneration (RHND)
Authors: Dyakin Victor Vasilyevich , Lajtha Abel , Dyakina‐Fagnano Nika Victorovna 
Published: December 2020

AbstractBackgroundBiochirality, evident in the homochirality of deoxyribonucleic acid (DNA) and the prevalent chirality of amino acids (AAs) in a bilateral organism, represents a challenge for modern biochemistry and neuroscience. Attention to the spontaneous post translational racemization allow revealing the link between protein aging, cell aging, and decline of cognitive functions should be highlighted.MethodAnalytical review of current advances in the molecular biology, biophysics, and neuroscience.ResultAt the protein level, biochirality is closely associated with various post‐translational modifications (PTMs), which support the dynamic balance of the prevalent chirality of enzymes and their substrates. This review posits a racemization hypothesis of neurodegeneration (RHND) that focuses on the distinct forms of the aberrant PTMs, which critically impact enzymes‐substrate interaction named spontaneous racemization. From a thermodynamic perspective, the collapse of homochirality by racemization is the result of a conformational non‐equilibrium phase transition. At the cellular level, the concept of non‐equilibrium phase transitions (PhTs) is relevant to the biophysics of PTMs, physiology of membrane‐less organelles (MLO), and intrinsically disordered proteins (IDPs). MLOs, containing IDPs, represent coherent structures with distinct protein dynamics and biological functions. MLOs containing IDPs are implicated in protein folding and aberrant protein conformation leading to aggregation diseases. Spontaneous, non‐enzymatic PTMs within MLOs represent the internal determinants of protein aging, cell aging and age‐related diseases. Recently it has been shown that the racemization of the serine (Ser) residue occurs (preferably) in the flexible (unstructured or intrinsically disordered) regions of proteins.ConclusionThe amyloid cascade hypothesis in Alzheimer’s disease (AD) needs to be reconciled with the failure of numerous Aβ targeting drug therapies in clinical trials. In our view, both neuroscience and thermodynamic advances are necessary for addressing the brain region, cell type, and age‐dependent racemization processes that critically influence nervous system functions. The link between protein aging, cell aging, and decline of cognitive functions should be highlighted. The chiral non‐equilibrium phase transitions (PhTs) concomitant with the protein misfolding and aggregation, evident in an increasing number of experimental results, convince as to introduce the RHND.
Social isolation, loneliness, and cognitive impairment in late life: The MYHAT study
Authors: Hughes Tiffany F , Fang Fang , Jacobsen Erin P , Snitz Beth E , Ganguli Mary 
Published: December 2020

AbstractBackgroundSocial isolation and loneliness have detrimental effects on the health of older adults. Being socially isolated and lonely are likely both predictors and consequences of cognitive impairment with aging. However, isolation and loneliness may be differentially associated with cognitive impairment and may operate through both shared and unique pathways. The present study aimed to examine the association of social isolation and loneliness with concurrent cognitive impairment, and to explore potential mechanisms of the association.MethodsParticipants (n =1,982; Mage = 77.65 years, 1,210 (61.1%) female, 1,877 (94.7%) white, 815 (41.12% > high school education) were from a population‐based study of mild cognitive impairment and dementia. Three composite measures derived from factor analysis, representing social network structure, social connectedness, and loneliness were examined in relation to clinical dementia rating (CDR normal = 0 vs. CDR impaired >= 0.5) at baseline, adjusted for demographic characteristics. The indirect effects of the composite measures were also estimated conditioned on general health and function, lifestyle factors, vascular health, depressive symptoms, and sleep.ResultsOf the participants, 569 (28.71%) were cognitively impaired at baseline. Social connectedness (OR 1.48, 95% CI=1.33‐1.64) and loneliness (OR 1.38, 95% CI=1.24‐1.54), but not social network structure, were significantly associated with greater likelihood of being cognitively impaired after adjustment for demographics. These effects remained significant after separate adjustments for general health and function, lifestyle factors, vascular health, depressive symptoms, sleep, and other composites. The effect of social connectedness was appreciably attenuated by general health status and function (OR 1.37, 95% CI=1.22‐1.54), while loneliness was appreciably attenuated by depressive symptoms (OR 1.26, 95% CI=1.12‐1.42).ConclusionsOlder adults with lower levels of social connectedness and higher perception of loneliness are more likely to be cognitively impaired, which were partially explained by health and function and depressive symptoms, respectively. Addressing these factors may reduce risk for cognitive impairment, or conversely, reduce risk for disconnectedness and loneliness among those with cognitive impairment. These results have implications for the impact that limited social contact and feelings of loneliness during the COVID‐19 pandemic may have on older adults with or at risk for cognitive impairment.
Are perceptions of self‐efficacy in preventing falls by persons with Alzheimer’s disease or related dementias considered by their family caregivers?
Authors: Panzer Victoria , Smith Veronica , Wakefield Dorothy , Fortinsky Richard H , Maher Joanne 
Published: December 2020

AbstractBackgroundFalls are common in Persons with Alzheimer’s disease and related dementias (PwADRD) which may be affected by their self‐efficacy or that of their Family Caregivers (CGs). Our earlier studies demonstrated that older adults may be over‐confident or timid and we explored whether CG’s self‐efficacy in preventing a fall or loss of balance (FLOB) for their PwADRD considered PwADRD confidence.MethodActivity‐Specific Balance Confidence (ABC) is a standardized scale in which confidence in preventing a FLOB is rated (0=no confidence to 10=completely confident) in 16 specific situations. Pilot testing with standard 0‐10, 5 or 3 point Likert scales was unsuccessful with PwADRD. Therefore, CGs self‐administered the ABC, rating their confidence (0‐10) in preventing PwADRD FLOBs, while the PwADRD responded ‘Yes I Can’ or ‘No I Can’t’ prevent a FLOB to trained Interviewers for each situation. ABCtotal (CG 0‐160, PwADRD 0‐16) and Spearman correlation between CG and PwADRD ABCtotal scores were calculated. Wilcoxon two sample tests compared CG ratings between groups (PwADRD who responded Yes and those who responded No) for each situation.ResultThirty‐three dyads were 85% White, 3‐6% Asian, African‐American, Hispanic or Pacific‐Islander. CGs were 91% female, average age=70.3 and ABCtotalmean=105.2, SD(26.3). PwADRD were 76% male, average age=77.2, MMSE score mean=22.3, SD(6.4) and ABCtotalmean=12, SD(2.6). The correlation between CG and PwADRD ABCtotal scores (r=0.349) was significant (p=.046). We compared CG ratings between the two groups (PwADRD who responded Yes or No) for each situation. Overall, PwADRD were confident they could prevent a FLOB. In six situations, there were 3 or less who responded No, I can’t. The CG median rating for the Yes group was significantly higher than the No group in only three situations: walk in crowd (8 vs. 5, p=.008), icy sidewalks (6 vs. 2, p=.047), and bend over (8 vs. 5.5, p=.058). In all other situations, there was no significant difference in CG ratings whether the PwADRD responded Yes or No.ConclusionIn many situations, CG's self‐efficacy for preventing FLOBs was similar irrespective of PwADRD confidence. This ‘Dual‐ABC’ approach may help to focus falls prevention interventions on situations in which the CG’s self‐efficacy does not consider the PwADRD’s confidence.
Harnessing the paradoxical phenotypes of APOE ɛ2 and APOE ɛ4 to identify genetic modifiers in Alzheimer's disease
Authors: Kim Young Won , Al‐Ramahi Ismael , Koire Amanda , Wilson Stephen J. , Konecki Daniel M. , Mota Samantha , Soleimani Shirin , Botas Juan , Lichtarge Olivier 
Published: December 2020

AbstractThe strongest genetic risk factor for idiopathic late‐onset Alzheimer's disease (LOAD) is apolipoprotein E (APOE) ɛ4, while the APOE ɛ2 allele is protective. However, there are paradoxical APOE ɛ4 carriers who remain disease‐free and APOE ɛ2 carriers with LOAD. We compared exomes of healthy APOE ɛ4 carriers and APOE ɛ2 Alzheimer's disease (AD) patients, prioritizing coding variants based on their predicted functional impact, and identified 216 genes with differential mutational load between these two populations. These candidate genes were significantly dysregulated in LOAD brains, and many modulated tau‐ or β42‐induced neurodegeneration in Drosophila. Variants in these genes were associated with AD risk, even in APOE ɛ3 homozygotes, showing robust predictive power for risk stratification. Network analyses revealed involvement of candidate genes in brain cell type‐specific pathways including synaptic biology, dendritic spine pruning and inflammation. These potential modifiers of LOAD may constitute novel biomarkers, provide potential therapeutic intervention avenues, and support applying this approach as larger whole exome sequencing cohorts become available.
Vascular health across young adulthood and midlife cerebral autoregulation, gait, and cognition
Authors: Mahinrad Simin , Shownkeen Meghana , Sedaghat Sanaz , Yaffe Kristine , Hausdorff Jeffrey M. , Lloyd‐Jones Donald M. , Gorelick Philip B. , Sorond Farzaneh A. 
Published: December 2020

AbstractIntroductionTo test the association of vascular health (VH) across young adulthood with midlife dynamic cerebral autoregulation (dCA), gait, and cognition; and to test whether dCA is a modifying factor.MethodsWe studied 196 participants from the Coronary Artery Risk Development in Young Adults cohort who were followed over 30 years. VH was assessed at each visit according to American Heart Association recommendations. At year 30, dCA was measured using transcranial Doppler ultrasound and several gait and cognitive domains were assessed.ResultsWorse VH from baseline through year 7, but not at year 30, was associated with less efficient dCA (all P < .05). Worse VH at all visits was associated with slower gait speed, and at year 7 with worse executive and global cognition (all P < .05). The association of baseline VH and midlife gait, but not cognition, was moderated by dCA (interaction P < .05).ConclusionsVH as early as young adulthood may influence midlife brain health, and dCA may modify this relationship.
Two‐Dimensional (2D) or Quasi‐2D Superstructures from DNA‐Coated Colloidal Particles
Authors: Liu Mingzhu , Zheng Xiaolong , Grebe Veronica , He Mingxin , Pine David J. , Weck Marcus 
Published: December 2020

AbstractThis contribution describes the synthesis of colloidal di‐patch particles functionalized with DNA on the patches and their assembly into colloidal superstructures via cooperative depletion and DNA‐mediated interactions. The assembly into flower‐like Kagome, brick‐wall like monolayer, orthogonal packed single or double layers, wrinkled monolayer, and colloidal honeycomb superstructures can be controlled by tuning the particles’ patch sizes and assembly conditions. Based on these experimental results, we generate an empirical phase diagram. The principles revealed by the phase diagram provide guidance in the design of two‐dimensional (2D) materials with desired superstructures. Our strategy might be translatable to the assembly of three‐dimensional (3D) colloidal structures.
Thiazolo[5,4‐d]thiazole‐Based Donor–Acceptor Covalent Organic Framework for Sunlight‐Driven Hydrogen Evolution
Authors: Li Wenqian , Huang Xiaofeng , Zeng Tengwu , Liu Yahu A. , Hu Weibo , Yang Hui , Zhang Yue‐Biao , Wen Ke 
Published: December 2020

Abstract2D covalent organic frameworks (COFs) could have well‐defined arrangements of photo‐ and electro‐active units that serve as electron or hole transport channels for solar energy harvesting and conversion, but their insufficient charge transfer and rapid charge recombination impede the sunlight‐driven photocatalytic performance. We report a new donor–acceptor (D–A) system, PyTz‐COF that was constructed from the electron‐rich pyrene (Py) and electron‐deficient thiazolo[5,4‐d]thiazole (Tz). With its bicontinuous heterojunction, PyTz‐COF demonstrated exceptional optoelectronic properties, photocatalytic ability in superoxide anion radical‐mediated coupling of (arylmethyl)amines and photoelectrochemical activity in sunlight‐driven hydrogen evolution. Remarkably, PyTz‐COF exhibited a photocurrent up to 100 μA cm−2 at 0.2 V vs. RHE and could reach a hydrogen evolution rate of 2072.4 μmol g−1 h−1. This work is paving the way for reticular design of highly efficient and highly active D–A systems for solar energy harvesting and conversion.
On‐POM Ring‐Opening Polymerisation of N‐Carboxyanhydrides
Authors: Soria‐Carrera Héctor , Franco‐Castillo Isabel , Romero Pilar , Martín Santiago , de la Fuente Jesús M. , Mitchell Scott G. , Martín‐Rapún Rafael 
Published: December 2020

AbstractThe ring‐opening polymerisation of α‐amino acid N‐carboxyanhydrides (NCAs) offers a simple and scalable route to polypeptides with predicted and narrow molecular weight distributions. Here we show how polyoxometalates (POMs)—redox‐active molecular metal‐oxide anions—can serve as inorganic scaffold initiators for such NCA polymerisations. This “On‐POM polymerisation” strategy serves as an innovative platform to design hybrid materials with additive or synergistic properties stemming from the inorganic and polypeptide component parts. We have used this synthetic approach to synthesise a library of bactericidal poly(lysine)–POM hybrid derivatives that can be used to prevent biofilm formation. This versatile “On‐POM polymerisation” method provides a flexible synthetic approach for combining inorganic scaffolds with amino acids, and the potential to tailor and improve the specificity and performance of hybrid antimicrobial materials.
Non‐Equilibrium Large‐Scale Membrane Transformations Driven by MinDE Biochemical Reaction Cycles
Authors: Fu Meifang , Franquelim Henri G. , Kretschmer Simon , Schwille Petra 
Published: December 2020

AbstractThe MinDE proteins from E. coli have received great attention as a paradigmatic biological pattern‐forming system. Recently, it has surfaced that these proteins do not only generate oscillating concentration gradients driven by ATP hydrolysis, but that they can reversibly deform giant vesicles. In order to explore the potential of Min proteins to actually perform mechanical work, we introduce a new model membrane system, flat vesicle stacks on top of a supported lipid bilayer. MinDE oscillations can repeatedly deform these flat vesicles into tubules and promote progressive membrane spreading through membrane adhesion. Dependent on membrane and buffer compositions, Min oscillations further induce robust bud formation. Altogether, we demonstrate that under specific conditions, MinDE self‐organization can result in work performed on biomimetic systems and achieve a straightforward mechanochemical coupling between the MinDE biochemical reaction cycle and membrane transformation.
Using a conductive sphere as a probe to characterize the sensitivity of soft piezoresistive films
Authors: Green Christopher , Rogers Jeremy , Kovenburg Robert , Aksak Burak 
Published: December 2020

AbstractFlexible piezoresistive films, such as, carbon black/polydimethylsiloxane (C‐PDMS) composites, are often used as skin analogs and integrated into complex array sensors for tactile sensing. The uniformity of the sensor characteristics heavily depends on the homogeneity of the composite. Therefore, the ability to locally characterize a film that will be integrated into a complex force sensor could be critical. Here, a method to characterize the local sensitivity of flexible piezoresistive films is presented. Using a conductive sphere, which was chosen over a flat probe to eliminate misalignment issues, the surface of a thin film composite is indented to characterize the change in resistivity in terms of average strain. Experiments were performed with 15 and 18 wt% carbon black C‐PDMS films of varying thickness. The contact radius of the probe with the piezoresistive film was estimated using the Johnson‐Roberts‐Kendall contact theory. Theoretical contact area estimates were found to agree with contact radius measurements carried out using optically transparent PDMS films observed through an optical microscope. Results show that C‐PDMS with 15 wt% carbon black exhibit a higher rate if change of resistivity and gauge factor than films of same thickness with 18 wt% carbon black. On the other hand, thicker films exhibit higher gauge factors for the two tested carbon black contents. Tests carried out at multiple locations yielded consistent sensitivity values, making these types of composites suitable for array type force sensors.
Potential antibacterial and antifungal activities of novel sulfamidophosphonate derivatives bearing the quinoline or quinolone moiety
Authors: Bazine Ismahene , Bendjedid Samira , Boukhari Abbes 
Published: December 2020

AbstractA series of new α‐sulfamidophosphonate/sulfonamidophosphonate (4a–n) and cyclosulfamidophosphonate (5a–d) derivatives containing the quinoline or quinolone moiety was designed and synthesized via Kabachnik–Fields reaction in the presence of ionic liquid under ultrasound irradiation. This efficient methodology provides new 1,2,5‐thiadiazolidine‐1,1‐dioxide derivatives 5a–d in one step and optimal conditions. The molecular structures of the novel compounds 4a–n and 5a–d were confirmed using various spectroscopic methods. All these compounds were evaluated for their in vitro antibacterial activity against Gram‐negative (Escherichia coli ATCC 25922 and Pseudomonas aeruginosa ATCC 27853) and Gram‐positive (Staphylococcus aureus ATCC 27923) bacteria, in addition to three clinical strains (E. coli 1, P. aeruginosa 1, and S. aureus 1). Most of the tested compounds showed more potent inhibitory activities against both Gram‐positive and ‐negative bacteria compared with the sulfamethoxazole reference. The following compounds, 4n, 4f, 4g, 4m, 4l, 4d, and 4e, are the most active sulfamidophosphonate derivatives. Furthermore, these molecules gave interesting zones of inhibition varying between 28 and 49 mm, against all tested bacterial strains, with a low minimum inhibitory concentration (MIC) value ranging from 0.125 to 8 μg/ml. All the synthesized derivatives were also evaluated for their in vitro antifungal activity against Fusarium oxyporum f. sp. lycopersici and Alternaria sp. The results revealed that all the synthesized compounds exhibited excellent antifungal inhibition and the compounds 4f, 4g, 4m, and 4i were the most potent derivatives with MIC values ranging from 0.25 to 1 µg/ml against the two tested fungal strains. The strongest inhibition of bacteria and fungi strains was detected by the effect of quinolone and sulfamide moieties.
Network architecture and sex chromosome turnovers
Authors: Tao Wenjing , Conte Matthew A. , Wang Deshou , Kocher Thomas D. 
Published: December 2020

AbstractRecent studies have revealed an astonishing diversity of sex chromosomes in many vertebrate lineages, prompting questions about the mechanisms of sex chromosome turnover. While there is considerable population genetic theory about the evolutionary forces promoting sex chromosome replacement, this theory has not yet been integrated with our understanding of the molecular and developmental genetics of sex determination. Here, we review recent data to examine four questions about how the structure of gene networks influences the evolution of sex determination. We argue that patterns of epistasis, arising from the structure of genetic networks, may play an important role in regulating the rates and patterns of sex chromosome replacement.
Patterning of protein‐based materials
Authors: Humenik Martin , Winkler Anika , Scheibel Thomas 
Published: December 2020

AbstractMicro‐ and nanopatterning of proteins on surfaces allows to develop for example high‐throughput biosensors in biomedical diagnostics and in general advances the understanding of cell‐material interactions in tissue engineering. Today, many techniques are available to generate protein pattern, ranging from technically simple ones, such as micro‐contact printing, to highly tunable optical lithography or even technically sophisticated scanning probe lithography. Here, one focus is on the progress made in the development of protein‐based materials as positive or negative photoresists allowing micro‐ to nanostructured scaffolds for biocompatible photonic, electronic and tissue engineering applications. The second one is on approaches, which allow a controlled spatiotemporal positioning of a single protein on surfaces, enabled by the recent developments in immobilization techniques coherent with the sensitive nature of proteins, defined protein orientation and maintenance of the protein activity at interfaces. The third one is on progress in photolithography‐based methods, which allow to control the formation of protein‐repellant/adhesive polymer brushes.
The minimalist process: An interpretivist study
Authors: Oliveira de Mendonça Gabrielle , Coelho Rocha Ana Raquel , Bogéa da Costa Tayt‐son Débora 
Published: December 2020

AbstractLifestyle politics express the politicization of everyday life and have emerged in opposition to the discourse, generally reproduced by the media, that consumption is essential to achieve a happy and satisfactory life. This paper investigates one of these lifestyles: minimalism. The adopters of this lifestyle believe that by avoiding overconsumption, they are adhering to conscious consumption and challenging the so‐called consumer society. Nevertheless, the development path for minimalists remains unclear. Through this multi‐method study, we seek to discover how a consumer becomes a minimalist. We targeted self‐proclaimed minimalists and members of Facebook communities related to this lifestyle politics. The findings led us to propose a visual representation of a non‐linear minimalist process, composed by overlapped stages, in which consumers choose to engage. By showing the component parts of minimalism, we indicate a new way to approach the topic. We also contributed to outline how consumers forge their identities through de‐growth in consumption practices and unveiled tensions behind minimalism lifestyle. We concluded by proposing venues for future research.