Exercise intervention on the brain structure and function of patients with mild cognitive impairment: systematic review based on magnetic resonance imaging studies.

Objective: This systematic review evaluates the impact of exercise intervention in MCI patients and discusses the potential neural mechanisms.

Methods: A systematic search and screening of relevant literature was conducted in English and Chinese databases. Based on predefined keywords and criteria, 24 articles were assessed and analyzed.

Tailoring the Buried Interface by Dipolar Halogen-Substituted Arylamine for Efficient and Stable Perovskite Solar Cells.

Improving the quality of the buried interface is decisive for achieving stable and high-efficiency perovskite solar cells. Herein, we report the interface engineering by using dipolar 2,4-difluoro-3,5-dichloroaniline (DDE) as the adhesive between titanium dioxide (TiO) and MAPbI. By manipulation of the anchoring groups of DDE, this molecule not only passivated defects of TiO but also optimized the energy level alignment.

Multifunctional Thiophene Cascading SnO/Perovskite Interfaces for Efficient and Stable MAPbI Photovoltaics.

The power conversion efficiency (PCE) and stability of n-i-p perovskite solar cells (PSCs) are significantly affected by inherent defects of SnO and perovskite layers. In this work, we incorporate 2-bromo-3-thiophenic acid (BrThCOOH) as a multifunctional passivant to simultaneously passivate the defects of SnO surface and perovskite layer. BrThCOOH permeates evenly into the MAPbI and coordinates with Pb and iodine vacancies (V) to reduce surface defect density and inhibit the decomposition of MAPbI.

Molecular Insights of Non-fused Ring Acceptors for High-Performance Non-fullerene Organic Solar Cells.

Non-fullerene acceptors with fused-ring structures have rapidly improved the performance of organic solar cells over the past five years, but they still suffer from synthetic complexity and thus high material costs, one of the major obstacles of hindering their commercialization process. The construction of non-fused ring acceptors (NFRAs) has recently been regarded as a feasible solution due to their facile synthesis and satisfactory device performances. Thus in this concept, we highlight the important progress of NFRAs in recent years, and discuss the key relationship between molecular design strategies and device performance.

An unfused-ring acceptor with high side-chain economy enabling 11.17% as-cast organic solar cells.

Side-chain engineering on nonfullerene acceptors (NFAs) is crucial for modulating their solubility and crystallinity as well as packing behaviours in active layers to pursue high-performance organic solar cells (OSCs). High weight ratios of side chains are generally used by NFAs for the desired device efficiencies. Side-chain economy has seldom been discussed despite increased cost and difficulties in synthesis when optimizing the molecular design.

Unfused Nonfullerene Acceptors Based on Simple Dipolar Merocyanines.

Merocyanine (MC) dyes exhibit facile synthesis and attractive optical properties, making them widely studied as the donor materials in organic solar cells (OSCs). In this study, for the first time, simple indole-based MCs are successfully designed as unfused nonfullerene acceptors (NFAs) for OSCs by forming dimers with A-D-π-D-A structure, which possess enhanced photostability compared to the well-known ITIC acceptor and high electron mobility in blend films. When blended with P3HT donor, one of the dimers, i.

A Simple Dithieno[3,2-b:2',3'-d]pyrrol-Rhodanine Molecular Third Component Enables Over 16.7% Efficiency and Stable Organic Solar Cells.

Organic solar cells (OSCs) can achieve greatly improved power conversion efficiency (PCE) by incorporating suitable additives in active layers. Their structure design often faces the challenge of operation generality for more binary blends. Herein, a simple dithieno[3,2-b:2',3'-d]pyrrole-rhodanine molecule (DR8) featuring high compatibility with polymer donor PM6 is developed as a cost-effective third component.

Over 15% Efficiency in Ternary Organic Solar Cells by Enhanced Charge Transport and Reduced Energy Loss.

In this study, an efficient ternary bulk-heterojunction (BHJ) organic solar cell (OSC) is demonstrated by incorporating two acceptors, PCBM and ITC6-4F, with a polymer donor (PM6). This reveals that the addition of PCBM not only enhances the electron mobility of the derived BHJ blend but also facilitates exciton dissociation, resulting in a more balanced charge transport alongside with reduced trap-assisted charge recombination. Consequently, as compared to the pristine PM6/ITC6-4F device, the optimal ternary OSC is revealed to deliver an improved power conversion efficiency (PCE) of 15.

Metal-organic framework-templated synthesis of sulfur-doped core-sheath nanoarrays and nanoporous carbon for flexible all-solid-state asymmetric supercapacitors.

Metal-organic frameworks (MOFs) provide great opportunities for synthesizing advanced electrode materials with hierarchical hollow architectures for energy storage. Herein, we report the facile fabrication of core-sheath nanoarrays (NAs) on carbon cloth (CC@CoO@S-Co3O4) for binder-free electrode materials with MOFs as versatile scaffolds. The hollow S-doped Co3O4 sheath has been facilely prepared using a two-step synthetic protocol, which includes the surface etching of CoO nanowires for synchronous in situ growth of well-aligned ZIF-67 and its following hydrothermal process.

Dithieno[3,2-b:2',3'-d]pyrrol Fused Nonfullerene Acceptors Enabling Over 13% Efficiency for Organic Solar Cells.

A new electron-rich central building block, 5,5,12,12-tetrakis(4-hexylphenyl)-indacenobis-(dithieno[3,2-b:2',3'-d]pyrrol) (INP), and two derivative nonfullerene acceptors (INPIC and INPIC-4F) are designed and synthesized. The two molecules reveal broad (600-900 nm) and strong absorption due to the satisfactory electron-donating ability of INP. Compared with its counterpart INPIC, fluorinated nonfullerene acceptor INPIC-4F exhibits a stronger near-infrared absorption with a narrower optical bandgap of 1.

High-Efficiency Nonfullerene Organic Solar Cells with a Parallel Tandem Configuration.

In this work, a highly efficient parallel connected tandem solar cell utilizing a nonfullerene acceptor is demonstrated. Guided by optical simulation, each of the active layer thicknesses of subcells are tuned to maximize its light trapping without spending intense effort to match photocurrent. Interestingly, a strong optical microcavity with dual oscillation centers is formed in a back subcell, which further enhances light absorption.

Side-chain Engineering of Benzo[1,2-b:4,5-b']dithiophene Core-structured Small Molecules for High-Performance Organic Solar Cells.

Three novel small molecules have been developed by side-chain engineering on benzo[1,2-b:4,5-b']dithiophene (BDT) core. The typical acceptor-donor-acceptor (A-D-A) structure is adopted with 4,8-functionalized BDT moieties as core, dioctylterthiophene as π bridge and 3-ethylrhodanine as electron-withdrawing end group. Side-chain engineering on BDT core exhibits small but measurable effect on the optoelectronic properties of small molecules.

Selenium-substituted polymers for improved photovoltaic performance.

Four isostructural donor-acceptor alternating polymers of benzodithiophene (BDT)/naphthodifuran (NDF) and benzoselenadiazole (BSe)/benzothiadiazole (BT) have been developed and evaluated for organic photovoltaics. The substitution of one-atom (Se for S) in the accepting units exerts remarkable impact on the optoelectronic properties of polymers. Extended absorption, narrowed bandgap and higher HOMO energy levels were observed for Se-containing polymers in comparison to their S-containing counterparts.

Design and photovoltaic characterization of dialkylthio benzo[1,2-b:4,5-b']dithiophene polymers with different accepting units.

Three dialkylthio benzo[1,2-b:4,5-b']dithiophene (S-BDT) based polymers have been developed using different accepting units to tune their bandgaps. The polymer:PC71BM solar cells achieved the highest power conversion efficiency (PCE) of 4.51% without any post-treatment (such as annealing and solvent additive) in conventional single-cell devices.

Design and photovoltaic characterization of dithieno[3,2-b:2',3'-d]silole copolymers with positioning phenyl groups.

A two-dimensional (2D) low bandgap polymer () based on dithieno[3,2-b:2',3'-d]silole (DTS) with phenyl substitution on the bridging silicon atom and thiazolo[5,4-d]thiazole (TTz) was designed and synthesized for photovoltaic applications. The impact of conjugated side chains on the optical, electrochemical and energy levels of the polymer was studied. The phenyl substituted DTS polymer exhibited a 0.

Effects of flip angle uncertainty and noise on the accuracy of DCE-MRI metrics: comparison between standard concentration-based and signal difference methods.

Dynamic contrast-enhanced MRI is becoming an increasingly important tool to assess tumors and their response to treatment. In the most common method of computing tumor perfusion parameters, the concentration of the injected contrast agent is first computed in both tumor and blood which is subsequently fit to a perfusion model, typically the Tofts two compartment model. However, this strategy can be highly sensitive to errors in the excitation flip angle and noise.

Comparison of lung T2* during free-breathing at 1.5 T and 3.0 T with ultrashort echo time imaging.

Assessment of lung effective transverse relaxation time (T(2)*) may play an important role in the detection of structural and functional changes caused by lung diseases such as emphysema and chronic bronchitis. While T(2)* measurements have been conducted in both animals and humans at 1.5 T, studies on human lung at 3.

Automatic coil selection for streak artifact reduction in radial MRI.

In radial MR imaging, streaking artifacts contaminating the entire field of view can arise from regions at the outer edges of the prescribed field of view. This can occur even when the Nyquist criterion is satisfied within the desired field of view. These artifacts become exacerbated when parts of the object lie in the superior/inferior regions of the scanner where the gradient strengths become weakened.

Facial expression recognition in JAFFE dataset based on Gaussian process classification.

The Gaussian process (GP) approaches to classification synthesize Bayesian methods and kernel techniques, which are developed for the purpose of small sample analysis. Here we propose a GP model and investigate it for the facial expression recognition in the Japanese female facial expression dataset. By the strategy of leave-one-out cross validation, the accuracy of the GP classifiers reaches 93.

Cross-platform microarray data integration using the normalised linear transform.

Small sample size is one of the biggest challenges in microarray data analysis. With microarray data being dramatically accumulated, integrating data from related studies represents a natural way to increase sample size so that more reliable statistical analysis may be performed. In this paper, we present a simple and effective integration scheme, called Normalised Linear Transform (NLT), to combine data from different microarray platforms.

Improved technique for measurement of regional fractional ventilation by hyperpolarized 3He MRI.

Quantitative measurement of regional lung ventilation is of great significance in assessment of lung function in many obstructive and restrictive pulmonary diseases. A new technique for regional measurement of fractional ventilation using hyperpolarized 3He MRI is proposed, addressing the shortcomings of an earlier approach that limited its use to small animals. The new approach allows for the acquisition of similar quantitative maps over a shortened period and requires substantially less 3He gas.

Simultaneous measurement of pulmonary partial pressure of oxygen and apparent diffusion coefficient by hyperpolarized 3He MRI.

Hyperpolarized (3)He (HP (3)He) MRI shows promise to assess structural and functional pulmonary parameters in a sensitive, regional, and noninvasive way. Structural HP (3)He MRI has applied the apparent diffusion coefficient (ADC) for the detection of disease-induced lung microstructure changes at the alveolar level, and HP (3)He pulmonary partial pressure of oxygen (pO(2)) imaging measures the oxygen transfer efficiency between the lung and blood stream. Although both parameters are affected in chronic obstructive pulmonary disease (COPD), a quantitative assessment of the regional correlation of the two parameters has not been reported in the literature.

A robust method for estimating regional pulmonary parameters in presence of noise.

Rationale And Objectives: Estimation of regional lung function parameters from hyperpolarized gas magnetic resonance images can be very sensitive to presence of noise. Clustering pixels and averaging over the resulting groups is an effective method for reducing the effects of noise in these images, commonly performed by grouping proximal pixels together, thus creating large groups called "bins." This method has several drawbacks, primarily that it can group dissimilar pixels together, and it degrades spatial resolution.