Sex-Specific Risk Factors and Clinical Dementia Outcomes for White Matter Hyperintensities in a large South Korean Cohort.

Objective: White matter hyperintensities (WMH) on brain MRI images are the most common feature of cerebral small vessel disease (CSVD). Studies have yielded divergent findings on the modifiable risk factors for WMH and WMH's impact on cognitive decline. Mounting evidence suggests sex differences in WMH burden and subsequent effects on cognition. Thus, we aimed to identify sex-specific modifiable risk factors for WMH. We then explored whether there were sex-specific associations of WMH to longitudinal clinical dementia outcomes. Methods: Participants aged 49-89 years were recruited at memory clinics and underwent a T2-weighted fluid-attenuated inversion recovery (FLAIR) 3T MRI scan to measure WMH volume. Participants were then recruited for two additional follow-up visits, 1-2 years apart, where clinical dementia rating sum of boxes (CDR-SB) scores were measured. We first explored which known modifiable risk factors for WMH were significant when tested for a sex-interaction effect. We additionally tested which risk factors were significant when stratified by sex. We then tested to see whether WMH is longitudinally associated with clinical dementia that is sex-specific. Results: The study utilized data from 713 participants (241 males, 472 females) with a mean age of 72.3 years and 72.8 years for males and females, respectively. 57.3% and 59.5% of participants were diagnosed with mild cognitive impairment (MCI) for males and females, respectively. 40.7% and 39.4% were diagnosed with dementia for males and females, respectively. Of the 713 participants, 181 participants had CDR-SB scores available for three longitudinal time points. Compared to males, females showed stronger association of age to WMH volume. Type 2 Diabetes was associated with greater WMH burden in females but not males. Finally, baseline WMH burden was associated with worse clinical dementia outcomes longitudinally in females but not in males. Discussion: Elderly females have an accelerated increase in cerebrovascular burden as they age, and subsequently are more vulnerable to clinical dementia decline due to CSVD. Additionally, females are more susceptible to the cerebrovascular consequences of diabetes. These findings emphasize the importance of considering sex when examining the consequences of CSVD. Future research should explore the underlying mechanisms driving these sex differences and personalized prevention and treatment strategies. Clinical trial registration: The BICWALZS is registered in the Korean National Clinical Trial Registry (Clinical Research Information Service; identifier, KCT0003391). Registration Date 2018/12/14.

Stapler Strategies for Upcycling Mixed Plastics.

Mechanical recycling is one of the simplest and most economical strategies to address ever-increasing plastic pollution, but it cannot be applied to immiscible mixed plastics and suffers from property deterioration after each cycle. By combining the amphiphilic block copolymer strategy and reactive compatibilization strategy, we designed a series of stapler strategies for compatibilizing/upcycling mixed plastics. First, various functionalized graft copolymers were accessed via different synthetic routes. Subsequently, the addition of a very small amount of stapler molecules induced a synergistic effect with the graft copolymers that improved the compatibility and mechanical properties of mixed plastics. These strategies were highly effective for various binary/ternary plastic systems and can be directly applied to postconsumer waste plastics, which can increase the toughness of mixed postconsumer waste plastics by 162 times. Most importantly, it also effectively improved the impact resistance, adhesion performance, and three-dimensional (3D) printing performance of mixed plastics, and permitted the recycling of plastic blends 20 times with minimal degradation in their mechanical properties.

Synthesis of Photoresponsive Fast Self-healing Polyolefin Composites by Nickel-Catalyzed Copolymerization of Ethylene and Lignin Cluster Monomers.

Polymers may suffer from sudden mechanical damages during long-term use under various harsh operating environments. Rapid and real-time self-healing will extend their service life, which is particularly attractive in the context of circular economy. In this work, a lignin cluster polymerization strategy (LCPS) was designed to prepare a series of lignin functionalized polyolefin composites with excellent mechanical properties through nickel catalyzed copolymerization of ethylene and lignin cluster monomers. These composites can achieve rapid self-healing within 30 seconds under a variety of extreme usage environments (underwater, seawater, extremely low temperatures as low as -60 °C, organic solvents, acid/alkali solvents, etc.), which is of great significance for real-time self-healing of sudden mechanical damage. More importantly, the dynamic cross-linking network within these composites enable great re-processability and amazing sealing performances.

Machine-learning-based feature selection to identify attention-deficit hyperactivity disorder using whole-brain white matter microstructure: A longitudinal study.

BACKGROUND: We aimed to identify important features of white matter microstructures collectively distinguishing individuals with attention-deficit/hyperactivity disorder (ADHD) from those without ADHD using a machine-learning approach. METHODS: Fifty-one ADHD patients and 60 typically developing controls (TDC) underwent diffusion spectrum imaging at two time points. We evaluated three models to classify ADHD and TDC using various machine-learning algorithms. Model 1 employed baseline white matter features of 45 white matter tracts at Time 1; Model 2 incorporated features from both time points; and Model 3 (main analysis) further included the relative rate of change per year of white matter tracts. RESULTS: The random forest algorithm demonstrated the best performance for classification. Model 1 achieved an area-under-the-curve (AUC) of 0.67. Model 3, incorporating Time 2 variables and relative rate of change per year, improved the performance (AUC = 0.73). In addition to identifying several white matter features at two time points, we found that the relative rate of change per year in the superior longitudinal fasciculus, frontal aslant tract, stria terminalis, inferior fronto-occipital fasciculus, thalamic and striatal tracts, and other tracts involving sensorimotor regions are important features of ADHD. A higher relative change rate in certain tracts was associated with greater improvement in visual attention, spatial short-term memory, and spatial working memory. CONCLUSIONS: Our findings support the significant diagnostic value of white matter microstructure and the developmental change rates of specific tracts, reflecting deviations from typical development trajectories, in identifying ADHD.

Durable Ru Nanocrystal with HfO2 Modification for Acidic Overall Water Splitting.

Durable and efficient bi-functional catalyst, that is capable of both oxygen evolution reaction and hydrogen evolution reaction under acidic condition, are highly desired for the commercialization of proton exchange membrane water electrolysis. Herein, we report a robust L-Ru/HfO2 heterostructure constructed via confining crystalline Ru nanodomains by HfO2 matrix. When assembled with a proton exchange membrane, the bi-functional L-Ru/HfO2 catalyst-based electrolyzer presents a voltage of 1.57 and 1.67 V to reach 100 and 300 mA cm-2 current density, prevailing most of previously reported Ru-based materials as well as commercial Pt/C||RuO2 electrolyzer. It is revealed that the synergistic effect of HfO2 modification and small crystalline domain formation significantly alleviates the over-oxidation of Ru. More importantly, this synergistic effect facilitates a dual-site oxide path during the oxygen evolution procedure via optimization of the binding configurations of oxygenated adsorbates. As a result, the Ru active sites maintain the metallic state along with reduced energy barrier for the rate-determining step (*O→*OOH). Both of water adsorption and dissociation (Volmer step) are strengthened, while a moderate hydrogen binding is achieved to accelerate the hydrogen desorption procedure (Tafel step). Consequently, the activity and stability of acidic overall water splitting are simultaneously enhanced.

Advanced brain aging in Parkinson's disease with cognitive impairment.

Patients with Parkinson's disease and cognitive impairment (PD-CI) deteriorate faster than those without cognitive impairment (PD-NCI), suggesting an underlying difference in the neurodegeneration process. We aimed to verify brain age differences in PD-CI and PD-NCI and their clinical significance. A total of 94 participants (PD-CI, n = 27; PD-NCI, n = 34; controls, n = 33) were recruited. Predicted age difference (PAD) based on gray matter (GM) and white matter (WM) features were estimated to represent the degree of brain aging. Patients with PD-CI showed greater GM-PAD (7.08 ± 6.64 years) and WM-PAD (8.82 ± 7.69 years) than those with PD-NCI (GM: 1.97 ± 7.13, Padjusted = 0.011; WM: 4.87 ± 7.88, Padjusted = 0.049) and controls (GM: -0.58 ± 7.04, Padjusted = 0.004; WM: 0.88 ± 7.45, Padjusted = 0.002) after adjusting demographic factors. In patients with PD, GM-PAD was negatively correlated with MMSE (Padjusted = 0.011) and MoCA (Padjusted = 0.013) and positively correlated with UPDRS Part II (Padjusted = 0.036). WM-PAD was negatively correlated with logical memory of immediate and delayed recalls (Padjusted = 0.003 and Padjusted < 0.001). Also, altered brain regions in PD-CI were identified and significantly correlated with brain age measures, implicating the neuroanatomical underpinning of neurodegeneration in PD-CI. Moreover, the brain age metrics can improve the classification between PD-CI and PD-NCI. The findings suggest that patients with PD-CI had advanced brain aging that was associated with poor cognitive functions. The identified neuroimaging features and brain age measures can serve as potential biomarkers of PD-CI.

Synthesis of Polar-functionalized Isotactic Polypropylenes Using Commercial Heterogeneous Ziegler-Natta Catalyst.

The efficient synthesis of polar-functionalized polypropylenes with high molecular weight and high stereoregularity represents a challenging task. This challenge becomes even more daunting when pursuing an industrially preferred heterogeneous process. This study demonstrated the realization of these goals through the use of commercial heterogeneous Ziegler-Natta catalysts in the copolymerization of propylene with ionic cluster polar monomers. The results revealed high copolymerization activity (∼1.1 × 107 g mol-1 h-1), moderate polar monomer incorporation ratios (∼4.9 mol %), high copolymer molecular weight (Mw > 105 g mol-1), high stereoregularity ([mmmm] ∼ 96%), and high melting temperature range (150-162 °C). The utilization of ionic cluster polar monomers improved the thermal stability as well as stereoselectivity of the catalyst. Moreover, the Ziegler-Natta catalyst can homopolymerize ionic cluster polar monomers with high activities (>104 g mol-1 h-1). The resulting polar-functionalized isotactic polypropylenes (iPP) exhibited superior tensile strength, impact strength, creep resistance, transparency, and crystallinity compared with nonpolar iPP. This enhancement was attributable to the dual roles of the ionic cluster polar monomer unit, serving as both a transparent nucleating agent and a dynamic cross-linking functionality. Furthermore, the polar-functionalized iPP exhibited improved compatibility with polar materials, offering benefits for applications in composites, recycling of mixed plastic wastes, 3D printing, and other fields. This study offered a comprehensive solution for the future industrial production of polar-functionalized iPP via copolymerization, bridging the gap between an efficient and practical copolymerization process from a synthetic chemistry perspective and enhanced material properties from an application perspective.

Light, Heat, and Force-Responsive Polyolefins.

Stimuli-responsive polymers have found applications as shape-memory materials, optical switches, and sensors, but the installation of these responsive properties in non-polar and inert polyolefins is challenging. In this contribution, a series of spiropyran (SP)-based comonomers are synthesized and copolymerized with ethylene or ethylene/cyclic monomers. In addition to great mechanical and surface properties, these functionalized polyolefins responded to light, heat, and force, which induced changes in the polymer structure to transmit color or mechanical signals. These interesting responsive properties are also installed in a series of commercial polyolefin materials through reactive extrusion, making the scalable production of these materials possible.

Polymer Multi-Block and Multi-Block+ Strategies for the Upcycling of Mixed Polyolefins and Other Plastics.

Due to a continued rise in the production and use of plastic products, their end-of-life pollution has become a pressing global issue. One of the biggest challenges in plastics recycling is the separation of different polymers. Multi-block copolymers (MBCPs) represent an efficient strategy for the upcycling of mixed plastics via induced compatibilization, but this approach is limited by difficulties associated with synthesis and structural modification. In this contribution, several synthetic strategies are explored to prepare MBCPs with tunable microstructures, which were then used as compatibilizer additives to upcycle mixtures of polyolefins with other plastics. A multi-block+ strategy based on a reactive telechelic block copolymer platform was introduced, which enabled block extension during the in situ melt blending of mixed plastics, leading to better compatibilizing properties as well as better 3D printing capability. This strategy was also applicable to more complex ternary plastic blends. The polymer multi-block strategy enabled by versatile MBCPs synthesis and the multi-block+ strategy enabled by in situ block extension show exciting opportunities for the upcycling of mixed plastics.

MISPEL: A supervised deep learning harmonization method for multi-scanner neuroimaging data.

Large-scale data obtained from aggregation of already collected multi-site neuroimaging datasets has brought benefits such as higher statistical power, reliability, and robustness to the studies. Despite these promises from growth in sample size, substantial technical variability stemming from differences in scanner specifications exists in the aggregated data and could inadvertently bias any downstream analyses on it. Such a challenge calls for data normalization and/or harmonization frameworks, in addition to comprehensive criteria to estimate the scanner-related variability and evaluate the harmonization frameworks. In this study, we propose MISPEL (Multi-scanner Image harmonization via Structure Preserving Embedding Learning), a supervised multi-scanner harmonization method that is naturally extendable to more than two scanners. We also designed a set of criteria to investigate the scanner-related technical variability and evaluate the harmonization techniques. As an essential requirement of our criteria, we introduced a multi-scanner matched dataset of 3T T1 images across four scanners, which, to the best of our knowledge is one of the few datasets of this kind. We also investigated our evaluations using two popular segmentation frameworks: FSL and segmentation in statistical parametric mapping (SPM). Lastly, we compared MISPEL to popular methods of normalization and harmonization, namely White Stripe, RAVEL, and CALAMITI. MISPEL outperformed these methods and is promising for many other neuroimaging modalities.

Outer-Shell Self-Supported Nickel Catalysts for the Synthesis of Polyolefin Composites.

In situ heterogeneous olefin polymerization has attracted much attention for the synthesis of polyolefin composites. However, the complicated syntheses of specially designed catalysts or the detrimental effects of interactions between catalyst and solid supports pose great challenges. In this contribution, an outer-shell self-supporting strategy was designed to heterogenize nickel catalysts on different fillers via precipitation homopolymerization of ionic cluster type polar monomer. These catalysts demonstrated high activity, good product morphology control, and stable performances in ethylene polymerization and copolymerization. Moreover, various polyolefin composites with great mechanical and customized properties can be efficiently synthesized.

Amine-Imine Nickel Catalysts with Pendant O-Donor Groups for Ethylene (Co)Polymerization.

The introduction of a secondary interaction is an efficient strategy to modulate transition-metal-catalyzed ethylene (co)polymerization. In this contribution, O-donor groups were suspended on amine-imine ligands to synthesize a series of nickel complexes. By adjusting the interaction between the nickel metal center and the O-donor group on the ligands, these nickel complexes exhibited high activities for ethylene polymerization (up to 3.48 × 106 gPE·molNi-1·h-1) with high molecular weight up to 5.59 × 105 g·mol-1 and produced good polyethylene elastomers (strain recovery (SR) = 69-81%). In addition, these nickel complexes can catalyze the copolymerization of ethylene with vinyl acetic acid, 6-chloro-1-hexene, 10-undecylenic, 10-undecenoic acid, and 10-undecylenic alcohol to prepare the functionalized polyolefins.

A co-anchoring strategy for the synthesis of polar bimodal polyethylene.

Since polar groups can poison the metal centers in catalysts, the incorporation of polar comonomers usually comes at the expense of catalytic activity and polymer molecular weight. In this contribution, we demonstrate polar bimodal polyethylene as a potential solution to this trade-off. The more-polar/more-branched low-molecular-weight fraction provides polarity and processability, while the less-polar/less-branched high-molecular-weight fraction provides mechanical and melt properties. To achieve high miscibility between these two fractions, three synthetic routes are investigated: mixtures of homogeneous catalysts, separately supported heterogeneous catalysts, and a co-anchoring strategy (CAS) to heterogenize different homogeneous catalysts on one solid support. The CAS route is the only viable strategy for the synthesis of polar bimodal polyethylene with good molecular level entanglement and minimal phase separation. This produces polyolefin materials with excellent mechanical properties, surface/dyeing properties, gas barrier properties, as well as extrudability and 3D-printability.

Atypical development in white matter microstructures in ADHD: A longitudinal diffusion imaging study.

BACKGROUND: In cross-sectional studies, alterations in white matter microstructure are evident in children with attention-deficit/hyperactivity disorder (ADHD) but not so prominent in adults with ADHD compared to typically-developing controls (TDC). Moreover, the developmental trajectories of white matter microstructures in ADHD are unclear, given the limited longitudinal imaging studies that characterize developmental changes in ADHD vs. TDC. METHODS: This longitudinal study acquired diffusion spectrum imaging (DSI) at two time points. The sample included 55 participants with ADHD and 61 TDC. The enrollment/first DSI age ranged from 7 to 18 years, with a five-year mean follow-up time. We examined time-by-diagnosis interaction on the generalized fractional anisotropy (GFA) of 45 white matter tracts, adjusting for confounding factors and correcting for multiple comparisons. We also tested whether the longitudinal changes of microstructures were associated with ADHD symptoms and attention performance in a computerized continuous performance test. RESULTS: Participants with ADHD showed more rapid development of GFA in the arcuate fasciculus, superior longitudinal fasciculus, frontal aslant tract, cingulum, inferior fronto-occipital fasciculus (IFOF), frontostriatal tract connecting the prefrontal cortex (FS-PFC), thalamic radiation, corticospinal tract, and corpus callosum. Within participants with ADHD, more rapid GFA increases in cingulum and FS-PFC were associated with slower decreases in inattention symptoms. In addition, in all participants, more rapid GFA increases in cingulum and IFOF were associated with greater improvement in attention performance. CONCLUSION: Our findings suggest atypical developmental trajectories of white matter tracts in ADHD, characterized by normalization and possible compensatory neuroplastic processes with age from childhood to early adulthood.

MoS2 nanosheets on plasma-nitrogen-doped carbon cloth for high-performance flexible supercapacitors.

With the surging demand for flexible and portable electronic devices featuring high energy and power density, the development of next-generation lightweight, flexible energy storage devices is crucial. However, achieving the expected energy and power density of supercapacitors remains a great challenge. This work reports a facile plasma-enabled method for preparing supercapacitor electrodes made of MoS2 nanosheets grown on flexible and lightweight N-doped carbon cloth (NCC). The MoS2/NCC presents an outstanding specific capacitance of 3834.28 mF/cm2 at 1 mA/cm2 and energy density of 260.94 µWh/cm2 at a power density of 354.48 µW/cm2. An aqueous symmetric supercapacitor fitted with two MoS2/NCC electrodes achieved the maximum energy density of 138.12 µWh/cm2 and the highest power density of 7,417.33 µW/cm2, along with the excellent cycling stability of 83.3 % retention over 10,000 cycles. The high-performance energy storage ASSSs (all-solid-state supercapacitors) are demonstrated to power devices in both rigid and flexible operation modes. This work provides a new perspective for fabricating high-performance all-solid-state flexible supercapacitors for clean energy storage.

Neurodevelopmental model of schizophrenia revisited: similarity in individual deviation and idiosyncrasy from the normative model of whole-brain white matter tracts and shared brain-cognition covariation with ADHD and ASD.

The neurodevelopmental model of schizophrenia is supported by multi-level impairments shared among schizophrenia and neurodevelopmental disorders. Despite schizophrenia and typical neurodevelopmental disorders, i.e., autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD), as disorders of brain dysconnectivity, no study has ever elucidated whether whole-brain white matter (WM) tracts integrity alterations overlap or diverge between these three disorders. Moreover, whether the linked dimensions of cognition and brain metrics per the Research Domain Criteria framework cut across diagnostic boundaries remains unknown. We aimed to map deviations from normative ranges of whole-brain major WM tracts for individual patients to investigate the similarity and differences among schizophrenia (281 patients subgrouped into the first-episode, subchronic and chronic phases), ASD (175 patients), and ADHD (279 patients). Sex-specific WM tract normative development was modeled from diffusion spectrum imaging of 626 typically developing controls (5-40 years). There were three significant findings. First, the patterns of deviation and idiosyncrasy of WM tracts were similar between schizophrenia and ADHD alongside ASD, particularly at the earlier stages of schizophrenia relative to chronic stages. Second, using the WM deviation patterns as features, schizophrenia cannot be separated from neurodevelopmental disorders in the unsupervised machine learning algorithm. Lastly, the canonical correlation analysis showed schizophrenia, ADHD, and ASD shared linked cognitive dimensions driven by WM deviations. Together, our results provide new insights into the neurodevelopmental facet of schizophrenia and its brain basis. Individual's WM deviations may contribute to diverse arrays of cognitive function along a continuum with phenotypic expressions from typical neurodevelopmental disorders to schizophrenia.

Cationic P,O-Coordinated Nickel(II) Catalysts for Carbonylative Polymerization of Ethylene: Unexpected Productivity via Subtle Electronic Variation.

Transition-metal-catalyzed copolymerization of ethylene with carbon monoxide affords polyketones materials with excellent mechanical strength, photodegradability, surface and barrier properties. Unlike the widely used and rather expensive Pd catalysts, Ni-catalyzed carbonylative polymerization is very difficult since the strong binding affinity of CO to Ni deactivates the highly electrophilic metal center easily. In this study, various cationic P,O-coordinated Ni complexes were synthesized using the electronic modulation strategy, and the catalyst with strong electron-donating substituents exhibits an excellent productivity of 104  g polymer (g Ni)-1 , which represents a rare discovery that a Ni complex could operate with such exceptional efficiency in comparison with Pd catalysts. Notably, those Ni catalysts were also efficient for terpolymerization of ethylene, propylene with CO for producing commercial polyketone materials with low melting temperatures and easy processibility.

A Cocatalyst Strategy to Enhance Ruthenium-Mediated Metathesis Reactivity towards Electron-Deficient Substrates.

Ruthenium-mediated olefin metathesis has been widely applied for the synthesis of various organic molecules and polymers. Inspired by the cocatalyst strategy for olefin polymerization, here we demonstrate that the abstraction of a chloride ion from various commercially available ruthenium catalysts significantly enhances their reactivity towards electron-deficient internal olefins. This cocatalyst strategy can be implemented in ethenolysis and cross-metathesis reactions of FG-CH=CH-FG type substrates bearing electron-withdrawing groups and the synthesis of telechelic polymers that can be converted to polyethylene-like materials with closed-loop recycling properties. The copolymerization of cyclic substrate with cycloolefins followed by hydrogenation afforded polyolefin materials with in-chain break points. Interestingly, switchable catalysis was achieved in the absence and presence of a cocatalyst, which allowed the polymer microstructure and material properties to be fine-tuned.

A general strategy for heterogenizing olefin polymerization catalysts and the synthesis of polyolefins and composites.

The heterogenization of homogeneous metal complexes on solid supports presents an efficient strategy for bridging homogeneous catalysts with industrially-preferred heterogeneous catalysts; however, a series of drawbacks restrict their implementation in olefin polymerization, particularly for copolymerization with polar comonomers. In this contribution, we report an ionic anchoring strategy that is highly versatile, generally applicable to different systems, and enables strong catalyst-support interactions while tolerating various polar functional groups. In addition to greatly enhanced polymerization properties, the supported catalysts achieved higher comonomer incorporation than their unsupported counterparts. This strategy enabled efficient polymerization at high temperatures at large scale and great control over product morphology, and the facile synthesis of polyolefin composites. More importantly, the dispersion of different fillers in the polyolefin matrix produced great material properties even at low composite loadings. It is expected that this strategy will find applications in different catalytic systems and the synthesis of advanced engineering materials.

Validation of neuroimaging-based brain age gap as a mediator between modifiable risk factors and cognition.

Neuroimaging-based brain age gap (BAG) is presumably a mediator linking modifiable risk factors to cognitive changes, but this has not been verified yet. To address this hypothesis, modality-specific brain age models were constructed and applied to a population-based cohort (N = 326) to estimate their BAG. Structural equation modeling was employed to investigate the mediation effect of BAG between modifiable risk factors (assessed by 2 cardiovascular risk scores) and cognitive functioning (examined by 4 cognitive assessments). The association between higher burden of modifiable risk factors and poorer cognitive functioning can be significantly mediated by a larger BAG (multimodal: p = 0.014, 40.8% mediation proportion; white matter-based: p = 0.023, 15.7% mediation proportion), which indicated an older brain. Subgroup analysis further revealed a steeper slope (p = 0.019) of association between cognitive functioning and multimodal BAG in the group of higher modifiable risks. The results confirm that BAG can serve as a mediating indicator linking risk loadings to cognitive functioning, implicating its potential in the management of cognitive aging and dementia.