Molecular packing in organic single crystals greatly influences their charge transport properties but can hardly be predicted and designed because of the complex intermolecular interactions. In this ...work, we have realized systematic fine-tuning of the single-crystal molecular packing of five benzodifurandione-based oligo(p-phenylenevinylene) (BDOPV)-based small molecules through incorporation of electronegative fluorine atoms on the BDOPV backbone. While these molecules all exhibit similar column stacking configurations in their single crystals, the intermolecular displacements and distances can be substantially modified by tuning of the amounts and/or the positions of the substituent fluorine atoms. Density functional theory calculations showed that the subtle differences in charge distribution or electrostatic potential induced by different fluorine substitutions play an important role in regulating the molecular packing of the BDOPV compounds. Consequently, the electronic couplings for electron transfer can vary from 71 meV in a slipped stack to 201 meV in a nearly cofacial antiparallel stack, leading to an increase in the electron mobility of the BDOPV derivatives from 2.6 to 12.6 cm2 V–1 s–1. The electron mobility of the five molecules did not show a good correlation with the LUMO levels, indicating that the distinct difference in charge transport properties is a result of the molecular packing. Our work not only provides a series of high-electron-mobility organic semiconductors but also demonstrates that fluorination is an effective approach for fine-tuning of single-crystal packing modes beyond simply lowering the molecular energy levels.
Recently, polymer field‐effect transistors have gone through rapid development. Nevertheless, charge transport mechanism and structure‐property relationship are less understood. Here we use strong ...electron‐deficient benzodifurandione‐based poly(p‐phenylene vinylene) (BDPPV) as polymer backbone and develop six BDPPV‐based polymers (BDPPV‐C1 to C6) with various side‐chain branching positions to systematically study the side‐chain effect on device performance. All the polymers exhibited ambient‐stable n‐type transporting behaviors with the highest electron mobility of up to 1.40 cm2 V−1 s−1. The film morphologies and microstructures of all the six polymers were systematically investigated. Our results demonstrate that the interchain π–π stacking distance decreases as moving the branching position away from polymer backbones, and an unprecedentedly close π–π stacking distance down to 3.38 Å is obtained for BDPPV‐C4 to C6. Nonetheless, closer π–π stacking distance does not always correlate with higher electron mobility. Polymer crystallinity, thin film disorder, and polymer packing conformation, which all influenced by side‐chain branching position, are proved to show significant influence on device performance. Our study not only reveals that π–π stacking distance is not the decisive factor on carrier mobility in conjugated polymers but also demonstrates that side‐chain branching position engineering is a powerful strategy to modulate and balance these factors in conjugated polymers.
Six BDPPV‐based polymers with various side‐chain branching positions are synthesized and characterized in details. All the polymers exhibit ambient‐stable n‐type transporting behavior with the highest electron mobility up to 1.40 cm2 V−1 s−1. By means of multiple characterization methods, film morphology, and microstructure of all the six polymers are systematically investigated.
It is uncertain whether rare
variants are associated with stroke and dementia in the general population and whether they lead to alterations in cognitive function. This study aims to determine the ...associations of rare
variants with prevalent and incident stroke and dementia, as well as cognitive function changes.
In the prospective community-based Shunyi Study, a total of 1007 participants were included in the baseline analysis. For the follow-up analysis, 1007 participants were included in the stroke analysis, and 870 participants in the dementia analysis. All participants underwent baseline brain magnetic resonance imaging, carotid ultrasound, and whole exome sequencing. Rare
variants were defined as variants with minor allele frequency <1%. A total of 137 rare
carriers were enrolled in the baseline study. At baseline, rare
variant carriers had higher rates of stroke (8.8% versus 5.6%) and dementia (2.9% versus 0.8%) compared with noncarriers. After adjustment for associated risk factors, the epidermal growth factor-like repeats (EGFr)-involving rare
variants were associated with a higher risk of prevalent stroke (odds ratio OR, 2.697 95% CI, 1.266-5.745;
=0.040) and dementia (OR, 8.498 95% CI, 1.727-41.812;
=0.032). After 5 years of follow-up, we did not find that the rare
variants increased the risk of incident stroke and dementia. There was no statistical difference in the change in longitudinal cognitive scale scores.
Rare
EGFr-involving variants are genetic risk factors for stroke and dementia in the general Chinese population.
Fluorinated and chlorinated isoindigo-based polymers, F-IIDT and Cl-IIDT, were developed as the donor materials for photovoltaic cells. Although showing similar frontier orbital energy levels, both ...polymers exhibited distinct solar cell device performance, for example, power conversion efficiency of 4.60% for Cl-IIDT and 1.19% for F-IIDT. The investigation of photophysical properties demonstrated that the strong preaggregation of F-IIDT was formed in solution due to increased noncovalent interactions between the backbones of the polymer. Therefore, large crystal domains in blended thin films with no preferred crystallographic orientation were obtained. On the other hand, the introduction of chlorine atoms increased the torsional angle of the polymer backbone, resulting in reduced crystallization tendency. Films with less crystallinity and face-on polymer orientation contributed to better device performance of Cl-IIDT. Our research proved that the effects of halogenation are far more than the tuning of frontier energy levels. Phase separation in blended films, including size of the crystallized domains and molecular packing orientation, is also greatly influenced by halogenation.
Kongzhuang coal mine of Shanghai Datun Energy Resources Co., Ltd. is a typical deep coal mine in eastern China. The mining disturbance of working face in deep coal mine leads to the fracture and ...movement of overlying strata and the damage of the aquifer in overlying strata, thereby causing water inrush disaster and posing a serious threat to the safety production in coal mine. Therefore, the temporal and spatial evolution mechanism of the water-conducting fractured zone of overlying strata in the Kongzhuang coal mine is researched systematically in this paper. Especially, the hydro-geological conditions and mining conditions in the Kongzhuang coal mine are analyzed; on this basis, the fracture and movement of overlying strata are simulated by physical similarity simulation test, and the temporal and spatial evolution rule of overlying strata in the Kongzhuang coal mine is obtained. Besides, the development height of “two zones” is measured by double-end water shutoff detection method, and the risk assessment for the water inrush disaster of the coal seam roof is carried out in the Kongzhuang coal mine. The research achievements in this paper indicate that the water-conducting channel formed in the mining process of #7 coal seam is the most important water-filling channel. Quaternary aquifer water recharges the mine indirectly through the bedrock aquifer, and the sandy mudstone with large thickness is the key layer to control the development of a water-conducting fracture zone. Meanwhile, the height of the caving zone is 26.7 m, about 8.3 times of mining height, and the height of the fracture zone is 68.3 m, approximately equal to 16.26 of the mining height. The results of #1 and #2 borehole leakages in the double-end water shutoff detection method show that the height of the water-conducting fractured zone is 63.70 m-65.27 m, and the split-to-mining ratio is 15.17-15.54. The water inrush risk of the coal seam roof shows that most of the 7436 working face is in the transition zone, and a small area around the cutting hole of the working face is in the relatively dangerous zone. Therefore, the innovation of this paper is that the temporal and spatial evolution mechanism of the water-conducting fractured zone of overlying strata in the Kongzhuang coal mine is revealed, which provides the theoretical guidance for the prediction and prevention of water inrush disaster in the coal mine with the similar mining conditions.
MicroRNA-34 (miR-34) is directly regulated by p53, and its potential tumor suppressive roles have been studied extensively. As a p53-induced microRNA, miR-34 functions as a tumor suppressor by ...playing a role in cell cycle arrest, apoptosis and metabolic regulation. Among these p53/miR-34 associated processes, apoptosis and cell cycle arrest are known as essential for p53/miR-34-mediated tumor suppression. P53-mediated metabolic processes have been shown to play pivotal roles in cancer cell biology. Recent studies have also identified several miR-34 targets involved in p53/miR-34-induced metabolic regulation. However, correlations among these metabolic targets remain to be fully elucidated. In this review, we summarize the current progress in the field of metabolic regulation by the p53/miR-34 axis and propose future directions for the development of metabolic approaches in anticancer therapy.
A gram-stain-positive, aerobic, rod-shaped bacterial strain capable of producing siderophores, named YIM B08730
T
, was isolated from a soil sample collected from Wumeng Mountain National Nature ...Reserve, Zhaotong City, Yunnan Province. Growth occurred at 10–45 °C (optimum, 35–40 ℃), pH 7.0–9.0 (optimum, 7.0) and in the presence of 0–5 % (w/v) NaCl (optimum, 0–1 %, w/v). A comparative analysis of the 16S rRNA gene sequence (1558 bp) of strain YIM B08730
T
showed the highest similarity to
Solibacillus isronensis
JCM 13838
T
(96.2 %), followed by
Solibacillus silvestris
DSM 12223
T
(96.0 %) and
Solibacillus kalamii
ISSFR-015
T
(95.4 %). The main polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylserine and one unidentified lipid. The main respiratory quinone of strain YIM B08730
T
was menaquinone 7 (MK-7). The major fatty acids were iso-C
15:0
and C
16:1
ω
7
c
alcohol. The digital DNA–DNA hybridization and average nucleotide identity values between strain YIM B08730
T
and the reference strain
S. isronensis
JCM 13838
T
were 24.8 % and 81.2 %, respectively. The G + C content of the genomic DNA was 37.1 mol%. The genome of the novel strain contained genes associated with the production of siderophores, and it also revealed other functional gene clusters involved in plant growth promotion and soil bioremediation. Based on these phenotypic, chemotaxonomic and phylogenetic analyses, strain YIM B08730
T
is considered to be a novel species of the genus
Solibacillus
, for which the name
Solibacillus ferritrahens
sp. nov. is proposed. The type strain is YIM B08730
T
(= NBRC 116268
T
= CGMCC 1.60169
T
).
Tuberculosis remains a threat to public health. The only approved vaccine, Bacillus Calmette-Guérin (BCG), is administered intradermally and provides limited protection, and its effect on innate ...immunity via the respiratory route has not been fully elucidated. A mouse model with genetically depleted TREM1 and seven-color flow cytometry staining were used to characterize the comprehensive immune response induced by respiratory BCG, through evaluating organ bacterial loads, lung histopathology, and lung immunohistochemistry. During respiratory BCG infection, the murine lungs displayed effective bacterial clearance. Notably, marked differences in neutrophils were observed between thymus and bone marrow cells, characterized by a significant increase in the expression of the triggering receptor expressed on myeloid cells 1 (TREM1). Subsequently, upon depletion of TREM1, a reduction in pulmonary neutrophils was observed, which further exacerbated bacterial loads and resulted in worsened pathology following respiratory BCG infection. In summary, up-regulated expression of TREM1 in rapidly increasing circulating neutrophil by pulmonary BCG is required for an efficient host response to BCG infection, and suggests the important role of TREM1 in neutrophil-related pulmonary bacteria clearance and pathology.
Dynamic performance analysis is essential for production systems facing random disturbances. In this paper, a vulnerability evaluation approach is proposed for smartphone assembly production systems ...with finite buffers under a resilient system analytic frame. Firstly, four important vulnerability indicators, namely Terminal Time Delay (TTD), Terminal Time Window (TTW), Bottleneck Time Delay (BTD), and Bottleneck Time Window (BTW), are defined to expound temporal and spatial attributes caused by disruptive events. Then, a recursive derivation approach of the queuing network model is presented to obtain a state-transition matrix, wherein machine reliability is also considered in the model. Afterward, the exact solutions of steady and transient vulnerability are evaluated based on state probabilities inference. Finally, numerical studies are carried out to validate the proposed method and translate it into a practical tool. An application program with vulnerability analysis and disturbance control functions is developed, embedded in the digital twin system independently developed by our team to solve practical problems.
Abstract Pediatric intestinal development is immature, vulnerable to external influences and produce a variety of intestinal diseases. At present, breakthroughs have been made in the treatment of ...pediatric intestinal diseases, but there are still many challenges, such as toxic side effects, drug resistance, and the lack of more effective treatments and specific drugs. In recent years, dietary polyphenols derived from plants have become a research hotspot in the treatment of pediatric intestinal diseases due to their outstanding pharmacological activities such, as anti‐inflammatory, antibacterial, antioxidant and regulation of intestinal flora. This article reviewed the mechanism of action and clinical evidence of dietary polyphenols in the treatment of pediatric intestinal diseases, and discussed the influence of physiological characteristics of children on the efficacy of polyphenols, and finally prospected the new dosage forms of polyphenols in pediatrics.
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