Layer-by-layer (LBL) sequential solution processing of the active layer has been proven as an effective strategy to improve the performance of organic solar cells (OSCs), which could adjust vertical ...phase separation and improve device performance. Although perylene diimide (PDI) derivatives are typical acceptors with excellent photoelectric properties, there are few studies on PDI-based LBL OSCs. Herein, three PDI acceptors (TBDPDI-C5, TBDPDI-C11, and SdiPDI) were used to fabricate LBL and bulk heterojunction (BHJ) OSCs, respectively. A series of studies including device optimization, photoluminescence (PL) quenching, dependence of light intensity, carrier mobility, atomic force microscopy (AFM), transmission electron microscopy (TEM), grazing-incidence wide-angle X-ray scattering (GIWAXS), and depth analysis X-ray photoelectron spectroscopy (DXPS) were carried out to make clear the difference of the PDI-based LBL and BHJ OSCs. The results show that LBL OSCs possess better charge transport, higher and more balanced carrier mobility, less exciton recombination loss, more favorable film morphology, and proper vertical component distribution. Therefore, all the three PDI acceptor-based LBL OSCs exhibit higher performance than their BHJ counterparts. Among them, TBDPDI-C5 performs best with a power conversion efficiency of 6.11% for LBL OSCs, higher than its BHJ OSC (5.14%). It is the first time for PDI small molecular acceptors to fabricate high-efficiency OSCs by using an LBL solution-processed method.
In this work, it is shown that the electrospun poly(vynilidene fluoride) (PVDF) nanofibers have polymer chains re-oriented along the fiber axis and the β-phase content reaches 72.7%, therefore being ...able to be implemented into electroactive device components. Further, nanoscale domain imaging and local piezoelectric coefficient d33 of the nanofibers have been intensively studied using piezoresponse force microscopy (PFM). The piezoelectric response (PR) imaging and butterfly amplitude loop have been demonstrated to confirm that the nanodomains result from the out-of-plane displacement and the d33 has an uneven distribution with the higher values on the fiber periphery.
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•A nanoscale manipulation of piezoelectric response in single polymeric nanofibers was proposed.•The sub-5nm spatial resolution was realized in depicting the domain imaging.•The out-of-plane nanodomains are strongly inhomogeneous and stronger on the fiber periphery.•The d33 has an uneven distribution with the higher values on the fiber periphery.
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•GG/HEC had little effect on the solubilization capacity of SDS micelles for methyl benzoate (MB).•Slight MB solubility enhancement in mixed polymer-SDS systems was due to weak ...interactions between polymer and MB and SDS.•The weak electrostatic repulsion between HEC/GG and SDS hinders the polymer to participate into SDS micelles.•The solubilization of polymers and the solubilization of micelles proceed independently, as in a single system.•Without attractive polymer-surfactant interaction, the solubilization capacity of SDS was not improved.
Micellar solubilization is considered as a key factor affecting the recovery efficiency in chemically enhanced oil recovery (cEOR). However, it is poorly understood how polymers in surfactant-polymer (SP) flooding influences the micellar solubilization. Guar gum (GG) and hydroxyethyl cellulose (HEC) are two important and widely used polysaccharide polymers. In this work, the effect of GG and HEC on the solubilization of a crude oil model compound methyl benzoate (MB) in anionic sodium dodecyl sulfate (SDS) micelles and the underlying mechanism were explored at the molecular scale by NMR spectroscopy. GG and HEC slightly increased the MB solubility in SDS micelles but did not change the solubilization capacity. No correlation peak was observed to demonstrate the attractive interaction between polymer and SDS. After examination, there is weak electrostatic repulsion between HEC/GG and SDS, which made the polymer independent from SDS micelles and was unable to participate in the formation of micelles to alter micellar structure and solubilization behavior. Although the solubility of MB was slightly increased, this increase should originate from weak molecular interactions between polymers, surfactants and hydrophobic molecules, including hydrogen bonding, van der Waals forces and hydrophobic interactions, etc. In summary, without strong electrostatic attraction between polymer and surfactant, the solubilization of polymers and the solubilization of micelles proceed independently, resulting in that the solubilization capacity of SDS micelles was not improved.
Rapid identification and continuous surveillance of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants are critical for guiding the response to the COVID-19 pandemic. Whole-genome ...sequencing (WGS) is a preferred tool for this aim, but many laboratories suffer from a lack of resources to support population-level sequencing. Here, we describe two PCR strategies targeting spike protein mutations to identify the Alpha, Delta, and Omicron variants. Signature mutations were selected using a dedicated bioinformatic program. The selected mutations in Alpha and Delta variants were detected using multicolor melting curve analysis (MMCA). Thirty-two mutations of the Omicron variant were targeted using the MeltArray approach in one reaction, which was able to detect the Omicron subvariants BA.1, BA.2, BA.3, and BA.4/5. The limits of detection varied from five to 50 copies of RNA templates/reactions. No cross-reactivity was observed with nine other respiratory viruses, including other coronaviruses. We validated the MMCA and MeltArray assays using 309 SARS-CoV-2 positive samples collected at different time points. These assays exhibited 98.3% to 100% sensitivity and 100% specificity compared with WGS. Multiplexed real-time PCR strategies represent an alternative tool capable of identifying current SARS-CoV-2 VOCs, adaptable for emerging variants and accessible for laboratories using existing equipment and personnel.
Rapid detection and mutation surveillance of SARS-CoV-2 VOCs is crucial for COVID-19 control, management, and prevention. We developed two rapid molecular assays based on the real-time PCR platform to identify important variants of concern, including the Omicron variant with a large number of mutations. Signature mutations were selected by an R program. Then, MMCA assays were established for Alpha and Delta variants, and a MeltArray assay targeting 32 mutations was developed for Omicron variant. These multiplexed PCR assays could be performed in a 96-well real-time PCR instrument within 2.5 h, offering a high-throughput choice for dynamic monitoring of SARS-CoV-2 VOCs in a standard microbiology laboratory.
Objectives
Interoception plays an important role in maintaining body homeostasis, which is closely associated with emotional health and the function of the autonomic nervous system (ANS). Tai Chi ...Chuan (TCC), as a typical mindfulness-based movement, is an effective integrative practice to alleviate negative emotions. This study aimed to explore the mediating role of different dimensions of interoception between TCC and emotional health.
Method
This study employed quasi-experimental design with pre-test and post-test pattern. The sample included 86 college students, 50 in the TCC group and 36 in the control group. The Depression Anxiety Stress Scales (DASS) was administered at baseline and 12-week follow-up to evaluate negative emotions, while three dimensions of interoception, interoceptive sensibility (IS), interoceptive accuracy (IAc) and interoceptive awareness (IAw), were measured by the Multidimensional Assessment of Interoceptive Awareness (MAIA), heartbeat counting task and confidence rating, respectively. Additionally, heart rate variability (HRV) during the abdominal breathing state at baseline and 12-week follow-up was collected.
Results
At follow-up, the TCC group showed decreased anxiety levels, increased IS and IAw, and increased HRV, while the control group showed increased DASS total score and score increases on all DASS sub-subscales. In the TCC group, increased IS was correlated with decreased negative emotions and increased HRV parameters. Moreover, the change in IS mediated the relationship between TCC intervention and decreased anxiety.
Conclusions
These findings suggest that IS might be one of the mechanisms of decreased anxiety after TCC intervention. It also sheds light on the clinical intervention of emotional disorders from an entirely new perspective.
Preregistration
This study is not pre-registered.
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•Composition of Mo-based nanoparticles embedded in carbon matrix is delicately controlled by initiator amount/calcination temperature.•N, S-doping and rich oxygen vacancies provide ...numerous catalytic defects.•Mo2C-Mo/C heterogeneous nanorods with abundant active heterointerfaces display remarkable HER activity and long-term durability.
Interfacial engineering of cost-effective non-noble materials is attractive for synthesizing advanced electrocatalysts toward hydrogen evolution reaction (HER). Herein, we prepare N, S-doped Mo2C-Mo/C heterogeneous nanorods (NSMB-1.25) with abundant active heterointerfaces and defect sites via in situ polymerization and carburization strategy. The polyaniline-derived heteroatom-doped carbon acts not only as a matrix but also as a carbon source for Mo2C formation. The phase transition of Mo2C-Mo heterostructure is accurately regulated by delicately varying the dosage of the polymerization initiator and calcine temperature. The synergistic effects of Mo2C, metallic Mo and N, S doping carbon significantly enhance the HER activity and durability of nanorods. Benefiting from the plentiful active sites of the Mo2C-Mo heterointerfaces, fast charge and mass transfer channels, heteroatomic doping and large surface area, the as-prepared NSMB-1.25 nanorods deliver only 118 mV overpotential at 10 mA cm−2 current density, small Tafel slopes of 74 mV dec-1, high exchange current density of 25.84 × 10-2 mA cm−2 and excellent stability in 1.0 M KOH solution. This work may support a feasible strategy for reasonably designing highly active heterogeneous interfaces to achieve efficient energy conversion and storage.
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•The out-of-plane piezoelectric response of PVDF nanofibers is much stronger than the in-plane.•The polarization switching occurs at 20Hz periodically with high sensitivity.•The ...piezoelectric coefficient (d33) of the nanofibers is diameter-dependent.•The thinnest nanofiber studied here is 30nm and it has the maximal |d33| of 38.5pmV−1.
We report piezoresponse force microscopy (PFM) studies of single electrospun polyvinylidene fluoride (PVDF) nanofibers on the Pt/Ti electrode substrate. The out-of-plane piezoelectric response is much stronger than the in-plane, which is dependent on the parameters of the electrospinning technique. Further, the local polarization switching of the thin nanofibers can be quantitatively characterized by the amplitude-voltage butterfly loop and phase-voltage hysteresis loop. The piezoelectric coefficient (d33) of the nanofibers is diameter-dependent. The thinnest nanofiber studied here is 30nm and has the maximal |d33| of 38.5pmV−1. The excellent piezoelectric properties of these low-dimensional nanofibers can facilitate the development in sensing and energy harvesting applications.
As a popular medicinal plant, Angelica dahurica has been attached to great importance in herbal medicine. Its main active compounds are furanocoumarins (FCs) including imperatorin and isoimperator ...which exhibit anti-oxidant, anti-tumor, and anti-virus activities. However, the enzymes catalyzing the crucial step of FCs’ biosynthesis pathway remain unidentified. This study initially screened six prenyltransferases (PTs)-coding sequences through transcriptome and gene expression profile analysis. Combined with qRT-PCR and in vitro enzyme activity verification, two C-PTs (AdPT1, 2) which convert umbelliferone to 7-demethylsuberosin (DMS), and one O-PT (AdPT3) which transforms xanthotoxol to imperatorin were identified. Among these PTs, AdPT2 also produces a trace amount of osthenol from umbelliferone. Homologous modeling, molecular docking, and site-directed mutagenesis analysis were also conducted and it is discovered that Asp301 and Asp305 in the two Asp-rich regions are vital for the activity of AdPT1. The study is the first to conduct a frontier exploration of the biosynthesis pathways of FCs in A. dahurica and will establish a foundation for the molecular mechanism of further C-PTs and O-PTs evolutionary studies.
All data needed to evaluate the conclusions in this paper are present in the paper and/or in supplementary. the accession numbers of AdPT1–3 are OP753387-OP733389, the raw RNA sequence reads are available as SRP289220.
•The first reported study on the key enzymes in the biosynthesis of the main active ingredient in Angelica dahurica.•Two kinds of prenyltransferases active on carbon or oxygen sites control the biosynthesis pathway of imperatorin.•Probing into essential amino acids determining the functions of PTs through molecular docking and site-directed mutagenesis.
To investigate the effectiveness and safety of tirofiban in patients with acute ischemic stroke (AIS) without large-vessel occlusions and not receiving intravenous thrombolysis.
Overall, 267 cases ...were included in the study (134 cases in tirofiban group; 133 cases in control group). After admission, patients in the tirofiban group were administered tirofiban for at least 72 h, and aspirin 100 mg and hydroclopidogrel 75 mg were administered 4 h before discontinuation of tirofiban administration. All patients were followed for 3 months, and the National Institutes of Health Stroke Scale (NIHSS) scores on admission, 24 h, and 7 d after treatment, intracerebral hemorrhage transformation within 48 h from stroke onset, and bleeding were assessed.
There was no significant difference between both groups in the incidence of non-symptomatic and symptomatic intracranial hemorrhage (sICH), extracranial hemorrhage events, and thrombocytopenia (p > 0.05). There was a significant different between the NIHSS scores at baseline and 7 d after treatment in the tirofiban group (p = 0.043). At 90 d after treatment, the proportion of patients with a good prognosis in the tirofiban group (modified Rankin Scale mRS = 0, 1) was higher than that in the control group (p = 0.021). There was no difference in the proportion of patients with a mRS score of 0–2 between the two groups (p > 0.05).
Administration of tirofiban for >72 h (72 h–108 h) is safe and can improve the long-term (90 d) prognosis of patients with AIS without large-vessel occlusions and not receiving intravenous thrombolysis.
Using chemical germ-line mutagenesis, we screened mice for defects in the humoral immune response to a type II T-independent immunogen and an experimental alphavirus vector. A total of 26 mutations ...that impair humoral immunity were recovered, and 19 of these mutations have been positionally cloned. Among the phenovariants were bumble , cellophane , and Worker ascribed to mutations in Nfkbid , Zeb1 , and Ruvbl2 , respectively. We show that IκBNS, the nuclear IκB-like protein encoded by Nfkbid , is required for the development of marginal zone and peritoneal B-1 B cells and additionally required for extrafollicular antibody responses to T-independent and -dependent immunogens. Zeb1 is also required for marginal zone and peritoneal B-1 B-cell development as well as T-cell development, germinal center formation, and memory B-cell responses. Finally, Ruvbl2 is required for T-cell development and maximal T-dependent antibody responses. Collectively, the mutations that we identified give us insight into the points at which disruption of an antibody response can occur. All of the mutations identified to date directly affect lymphocyte development or function; none have an exclusive effect on cells of the innate immune system.
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