Kinetics Controlled Perovskite Crystallization for High Performance Solar Cells.

The power conversion efficiencies (PCEs) of perovskite solar cells have recently developed rapidly compared to crystalline silicon solar cells. To have an effective way to control the crystallization of perovskite thin films is the key for achieving good device performance. However, a paradox in perovskite crystallization is from the mismatch between nucleation and Oswald ripening. Usually, the large numbers of nucleation sites tend to weak Oswald ripening. Here, we proposed a new mechanism to promote the formation of nucleation sites by reducing surface energy from 44.9 mN/m to 36.1 mN/m, to spontaneously accelerate the later Oswald ripening process by improving the grain solubility through the elastic modulus regulation. The ripening rate is increased from 2.37 Åm ⋅ s-1 to 4.61 Åm ⋅ s-1 during annealing. Finally, the solar cells derived from the optimized films showed significantly improved PCE from 23.14 % to 25.32 %. The long-term stability tests show excellent thermal stability (the optimized device without encapsulation maintaining 82 % of its initial PCE after 800 h aging at 85 °C) and an improved light stability under illumination. This work provides a new method, the elastic modulus regulation, to enhance the ripening process.

Deciphering the Roles of MA-Based Volatile Additives for α-FAPbI3 to Enable Efficient Inverted Perovskite Solar Cells.

Functional additives that can interact with the perovskite precursors to form the intermediate phase have been proven essential in obtaining uniform and stable α-FAPbI3 films. Among them, Cl-based volatile additives are the most prevalent in the literature. However, their exact role is still unclear, especially in inverted perovskite solar cells (PSCs). In this work, we have systematically studied the functions of Cl-based volatile additives and MA-based additives in formamidinium lead iodide (FAPbI3)-based inverted PSCs. Using in situ photoluminescence, we provide clear evidence to unravel the different roles of volatile additives (NH4Cl, FACl, and MACl) and MA-based additives (MACl, MABr, and MAI) in the nucleation, crystallization, and phase transition of FAPbI3. Three different kinds of crystallization routes are proposed based on the above additives. The non-MA volatile additives (NH4Cl and FACl) were found to promote crystallization and lower the phase-transition temperatures. The MA-based additives could quickly induce MA-rich nuclei to form pure α-phase FAPbI3 and dramatically reduce phase-transition temperatures. Furthermore, volatile MACl provides a unique effect on promoting the growth of secondary crystallization during annealing. The optimized solar cells with MACl can achieve an efficiency of 23.1%, which is the highest in inverted FAPbI3-based PSCs.

High Thermoelectric Performance Related to PVDF Ferroelectric Domains in P-Type Flexible PVDF-Bi0.5 Sb1.5 Te3 Composite Film.

There is increasing demand to power Internet of Things devices using ambient energy sources. Flexible, low-temperature, organic/inorganic thermoelectric devices are a breakthrough next-generation approach to meet this challenge. However, these systems suffer from poor performance and expensive processing preventing wide application of the technology. In this study, by combining a ferroelectric polymer (Polyvinylidene fluoride (PVDF, ß phase)) with p-type Bi0.5 Sb1.5 Te3 (BST) a thermoelectric composite film with maximum is produced power factor. Energy filter from ferroelectric-thermoelectric junction also leads to high Seebeck voltage ≈242 µV K-1 . For the first time, compelling evidence is provided that the dipole of a ferroelectric material is helping decouple electron transport related to carrier mobility and the Seebeck coefficient, to provide 5× or more improvement in thermoelectric power factor. The best composition, PVDF/BST film with BST 95 wt.% has a power factor of 712 µW•m-1  K-2 . A thermoelectric generator fabricated from a PVDF/BST film demonstrated Pmax T 12.02 µW and Pdensity 40.8 W m-2 under 50 K temperature difference. This development also provides a new insight into a physical technique, applicable to both flexible and non-flexible thermoelectrics, to obtain comprehensive thermoelectric performance.

Controllable Black-to-Yellow Phase Transition by Tuning the Lattice Symmetry in Perovskite Quantum Dots.

The black-to-yellow phase transition in perovskite quantum dots (QDs) is more complex than in bulk perovskites, regarding the role of surface energy. Here, with the assistance of in situ grazing-incidence wide-angle and small-angle X-ray scattering (GIWAXS/GISAXS), distinct phase behaviors of cesium lead iodide (CsPbI3 ) QD films under two different temperature profiles-instant heating-up (IHU) and slow heating-up (SHU) is investigated. The IHU process can cause the phase transition from black phase to yellow phase, while under the SHU process, the majority remains in black phase. Detailed studies and structural refinement analysis reveal that the phase transition is triggered by the removal of surface ligands, which switches the energy landscape. The lattice symmetry determines the transition rate and the coexistence black-to-yellow phase ratio. The SHU process allows longer relaxation time for a more ordered QD packing, which helps sustain the lattice symmetry and stabilizes the black phase. Therefore, one can use the lattice symmetry as a general index to monitor the CsPbI3 QD phase transition and finetune the coexistence black-to-yellow phase ratio for niche applications.

Anti- IL-22 neutralizing antibodies decrease inflammation lesions and reduce mortality in enterovirus 71-infected mice.

Hand, foot, and mouth disease (HFMD) can cause fatal encephalitis in 0-5-year-old infants and children. There is no effective antiviral drug available to treat HFMD caused by enterovirus 71 (EV71). Our study investigates the relationship between levels of IL-22 expression and the severity of disease after EV71 infection in a mouse model. Anti-IL-22 neutralizing antibodies were tested in EV71-infected mice of different ages. Our results show that anti-IL-22 neutralizing antibodies can effectively reduce mortality in EV71-infected mice. Anti-IL-22 neutralizing antibody effectively reduced various EV71-associated symptoms indicating promising potential of this therapeutic effector in patients with EV71-associated HFMD.

Nanoscale Valley Modulation by Surface Plasmon Interference.

Excitons in two-dimensional (2D) materials have attracted the attention of the community to develop improved photoelectronic devices. Previous reports are based on direct excitation where the out-of-plane illumination projects a uniform single-mode light spot. However, because of the optical diffraction limit, the minimal spot size is a few micrometers, inhibiting the precise manipulation and control of excitons at the nanoscale level. Herein, we introduced the in-plane coherent surface plasmonic interference (SPI) field to excite and modulate excitons remotely. Compared to the out-of-plane light, a uniform in-plane SPI suggests a more compact spatial volume and an abundance of mode selections for a single or an array of device modulation. Our results not only build up a fundamental platform for operating and encoding the exciton states at the nanoscale level but also provide a new avenue toward all-optical integrated valleytronic chips for future quantum computation and information applications.

Paraxial 3D shape measurement using parallel single-pixel imaging.

Three-dimensional (3D) shape measurement with fringe projection technique and vertical scanning setup can alleviate the problem of shadow and occlusion. However, the shape-from-defocus based method suffers from limited sensitivity and low signal-to-noise ratio (SNR), whereas the projection-triangulation based is sensitive to the zero-phase detection. In this paper, we propose paraxial 3D shape measurement using parallel single-pixel imaging (PSI). The depth is encoded in the radial distance to the projector optical center, which is determined by the projection of light transport coefficients (LTCs). The third-order polynomial fitting is used for depth mapping and calibration. Experiments on 5 objects with different materials and textures are conducted, and standards are measured to test the accuracy. The results verified that the proposed method can achieve robust, dense reconstruction with depth accuracy at 20 µm while the root-mean-square error (RMSE) of plane fitting up to 43 µm.

Compressive parallel single-pixel imaging for efficient 3D shape measurement in the presence of strong interreflections by using a sampling Fourier strategy.

We present a compressive parallel single-pixel imaging (cPSI) method, which applies compressive sensing in the context of PSI, to achieve highly efficient light transport coefficients capture and 3D reconstruction in the presence of strong interreflections. A characteristic-based sampling strategy is introduced that has sampling frequencies with high energy and high probability. The characteristic-based sampling strategy is compared with various state-of-the-art sampling strategies, including the square, circular, uniform random, and distance-based sampling strategies. Experimental results demonstrate that the characteristic-based sampling strategy exhibits the best performance, and cPSI can obtain highly accurate 3D shape data in the presence of strong interreflections with high efficiency.

Effect of Sodium Dodecyl Sulfonate on the Foam Stability and Adsorption Configuration of Dodecylamine at the Gas-Liquid Interface.

In this study, the effect of sodium dodecyl sulfonate (SDS) on the foam stability of dodecylamine (DDA) and on its adsorption configuration at the gas-liquid interface was investigated. Froth stability experiments, surface tension measurements, time-of-flight secondary-ion mass spectrometry measurements, and molecular dynamics simulation calculations were performed in this investigation. The results revealed that the foam stability of DDA solution was extremely strong, and the addition of SDS could decrease the foam stability when the concentration of DDA was less than a certain value. The decrease in foam stability could be ascribed to several reasons, namely, the big cross-sectional area of SDS at the gas-liquid interface and low adsorption capacity of surfactants at the gas-liquid interface, the high surface tension, the change in the double-layer structure, the small thickness of the gas-liquid interfacial layer, the weak interaction intensity between the head groups of the surfactants and the water molecules, the strong movement ability of the water molecules around the head groups, and the sparse and less upright arrangement configuration of molecules at the gas-liquid interface. These findings can greatly help in solving the strong foam stability problem in DDA flotation and provide a method for reducing foam stability.

Broccoli microgreens juice reduces body weight by enhancing insulin sensitivity and modulating gut microbiota in high-fat diet-induced C57BL/6J obese mice.

PURPOSE: This study aimed to explore the protective effect of broccoli microgreens juice (BMJ) during C57BL/6J mice obesity development. METHODS: The obese model mice, induced by feeding high-fat diet (HFD), were treated with BMJ by gavage for 10 weeks. Melbine was gavaged at 300 mg/(kg bw)/d, as a positive control group. RESULTS: BMJ supplementation significantly reduced white adipose tissues (WAT) mass, the body weight and adipocyte size, and increased water intake in HFD-fed mice. Moreover, it improved glucose tolerance, reduced insulin level and HOMA-IR value, and alleviated insulin resistance. Compared with the HFD group, BMJ supplementation significantly increased the relative abundance of Bacteroidetes and decreased the ratio of Firmicutes to Bacteroidetes at the phylum level, and enriched Bacteroides_acidifaciens at the species level. These changes in the composition of gut microbiota are associated with the production of short-chain fatty acids (SCFAs), and reduced LPS levels, and had an obvious anti-inflammatory effect. CONCLUSIONS: These findings suggested that the protective effects of BMJ on diet-induced obesity may be involved in gut microbiota-SCFAs-LPS-inflammatory axis. In addition, BMJ can enhance liver antioxidant capacity and reduce liver fat accumulation. Consequently, these results sustain BMJ as a novel functional food for obesity, on the basis of its opposing effects on HFD-induced obesity in mice.

High-Accuracy 3-D Sensor for Rivet Inspection Using Fringe Projection Profilometry with Texture Constraint.

Riveted workpieces are widely used in manufacturing; however, current inspection sensors are mainly limited in nondestructive testing and obtaining the high-accuracy dimension automatically is difficult. We developed a 3-D sensor for rivet inspection using fringe projection profilometry (FPP) with texture constraint. We used multi-intensity high dynamic range (HDR) FPP method to address the varying reflectance of the metal surface then utilized an additional constraint calculated from the fused HDR texture to compensate for the artifacts caused by phase mixture around the stepwise edge. By combining the 2-D contours and 3-D FPP data, rivets can be easily segmented, and the edge points can be further refined for diameter measurement. We tested the performance on a sample of riveted aluminum frame and evaluated the accuracy using standard objects. Experiments show that denser 3-D data of a riveted metal workpiece can be acquired with high accuracy. Compared with the traditional FPP method, the diameter measurement accuracy can be improved by 50%.

Electrospinning Ag-TiO2 Nanorod-Loaded Air Treatment Filters and Their Applications in Air Purification.

The efficient treatment of the problem of air pollution is a practical issue related to human health. The development of multi-functional air treatment filters, which can remove various kinds of pollutants, including particulate matter (PM) and organic gases, is a tireless pursuit aiming to address the actual needs of humans. Advanced materials and nano-manufacturing technology have brought about the opportunity to change conventional air filters for practical demands, with the aim of achieving the high-efficiency utilization of photons, a strong catalytic ability, and the synergetic degradation of multi-pollutants. In this work, visible-responding photocatalytic air treatment filters were prepared and combined with a fast and cost-effective electrospinning process. Firstly, we synthesized Ag-loaded TiO2 nanorod composites with a controlled size and number of loaded Ag nanoparticles. Then, multi-functional air treatment filters were designed by loading catalysts on electrospinning nanofibers combined with a programmable brush. We found that such Ag-TiO2 nanorod composite-loaded nanofibers displayed prominent PM filtration (~90%) and the degradation of organic pollutants (above 90%). The superior performance of purification could be demonstrated in two aspects. One was the improvement of the adsorption of pollutants derived from the increase of the specific surface area after the loading of catalysts, and the other was the plasmonic hot carriers, which induced a broadening of the optical absorption in the visible light range, meaning that many more photons were utilized effectively. The designed air treatment filters with synergistic effects for eliminating both PM and organic pollutants have promising potential for the future design and application of novel air treatment devices.

Defocusing parameter selection strategies based on PSF measurement for square-binary defocusing fringe projection profilometry.

Three-dimensional (3D) shape measurement system with binary defocusing technique can perform high-speed and flexible measurements if binary fringe patterns are defocused by projector properly. However, the actual defocusing degree is difficult to set, and the fringe period is difficult to determine accordingly. In this study, we present a square-binary defocusing parameter selection framework. First, we analyze the fringe formation process mathematically. The defocusing degree is quantified and manipulated by using the focusing distance of projector, which is calibrated by point spread function measurement. To optimize parameter selection, single-point sinusoidal error is modeled as the objective function for the evaluation of the defocusing effect. We verify the correctness by using different parameter combinations and object measurements in our experiments. The appropriate defocusing parameters can be easily obtained according to the analysis of practical system setup, which improves the quality and robustness of the system.

Aeroembolism in left atrium during catheter ablation of atrial fibrillation in a patient with dextrocardia: a case report and review of the literature.

BACKGROUND: Air embolus penetrating into heart chamber as a complication during percutaneous radiofrequency catheter ablation has been infrequently reported. CASE PRESENTATION: A 55-year-old man with dextrocardia who suffered from abdominal pain was suspected to have multiple arterial thromboembolisms, which might have originated from left atrium thrombosis since he had atrial fibrillation. He received oral anticoagulant therapy and catheter ablation of the arrhythmia. During the ablation procedure, an iatrogenic aeroembolism penetrated into the left atrium due to improper operation. Ultimately, the entire air embolus was extracted from the patient, who was free of any aeroembolism events thereafter. CONCLUSIONS: It is essential for an operator to pay full attention to all details of the procedure to avoid an aeroembolism during catheter ablation. In case of aeroembolism, removal by aspiration is an optimal and effective treatment.

Meta-analysis of drug-eluting versus bare metal stents in patients with indications for oral anticoagulation undergoing coronary stenting.

BACKGROUND: Current expert consensus recommends the use of bare metal stent (BMS) for patients with an indication for oral anticoagulation (OAC) undergoing coronary stenting. The use of drug-eluting stents (DES) should be limited. However, there is a lack of evidence to support these recommendations. We performed a meta-analysis to compare the efficacy and safety of DES to BMS in these patients. METHODS: We searched PubMed, Embase, the Cochrane library, and relevant journals. Studies comparing the efficacy and safety of DES to BMS in patients with an indication for OAC undergoing coronary stenting were included. End points included major adverse cardiac events (MACE), death, bleeding complications, and stroke. The outcome assessments were measured by hazard ratio (HR) and its 95% confidence interval. RESULTS: We yielded 453 studies by primary searching. According to the inclusion criteria, four studies enrolling 1,522 patients were finally included. A pooled estimate of HR for MACE, all-cause mortality, myocardial infarction, and bleeding complications showed no significant differences between patients treated with DES and BMS. The risk of target vessel revascularization (TVR) was significantly decreased in the DES implanted patients in comparison with patients with a BMS implantation. CONCLUSION: For patients with an indication for OAC undergoing coronary stenting, DES might a DES can be as safely used as a BMS, and is superior in reducing the risk of TVR.

Absence of GATA3/FOXA1 co-expression predicts poor prognosis in upper tract urothelial carcinoma.

Objective: GATA binding protein 3 (GATA3) and forkhead box A1 (FOXA1) have been individually implicated in the progression of upper tract urothelial carcinoma (UTUC). This study aims to evaluate the prognostic value of GATA3/FOXA1 co-expression in UTUC patients. Methods: We collected 108 UTUC pathological tissue samples with complete follow-up data and 24 normal control urothelial tissues. We created a 132-site microarray and performed immunohistochemistry (IHC) to measure GATA3 and FOXA1 expression levels. Kaplan-Meier survival and Cox regression analyses were conducted to assess UTUC prognosis. Results: GATA3 expression was positively correlated with FOXA1 (P=0.031). Absence of GATA3/FOXA1 co-expression (GATA3-/FOXA1-) was associated with tumor extensive necrosis (P=0.001) after Bonferroni correction for multiple comparisons. GATA3-/FOXA1- was associated with shorter Disease-Free Survival (DFS) (P=0.001) and Cancer-Specific Survival (CSS) (P<0.001) than other combination groups. Multivariate analyses identified extensive necrosis as an independent prognostic factor for CSS (P=0.030). Conclusions: Our study revealed a positive correlation between GATA3 and FOXA1 expression in UTUC. GATA3-/FOXA1- is linked to tumor extensive necrosis and poor prognosis in UTUC and may serve as a potential biomarker for UTUC patients.

Transcutaneous auricular vagus nerve stimulation improves working memory in temporal lobe epilepsy: A randomized double-blind study.

AIMS: This study investigated the impact of transcutaneous auricular vagus nerve stimulation (taVNS) on working memory (WM) in refractory temporal lobe epilepsy (rTLE) and the underlying mechanisms. METHODS: In this randomized double-blind study, 28 rTLE patients were subjected to an active or sham taVNS (a/s-taVNS) protocol for 20 weeks (a-taVNS group, n = 19; s-ta VNS group, n = 9). Patients performed visual WM tasks during stimulation and neural oscillations were simultaneously recorded by 19-channel electroencephalography. RESULTS: Compared with the baseline state, reaction time was significantly shorter after 20 weeks of taVNS in the a-taVNS group (p = 0.010), whereas no difference was observed in the s-taVNS group (p > 0.05). The power spectral density (PSD) of the theta frequency band in the Fz channel decreased significantly after a-taVNS during WM-encoding (p = 0.020), maintenance (p = 0.038), and retrieval (p = 0.039) phases, but not in the s-taVNS group (all p > 0.05). CONCLUSION: Neural oscillations during WM were altered by taVNS and WM performance was improved. Alterations in frontal midline theta oscillations may be a marker for the effect of taVNS on cognitive regulation.

Comparative Analysis of the Effect of Dietary Supplementation with Fermented and Water-Extracted Leaf Extracts of Eucommia ulmoides on Egg Production and Egg Nutrition.

Although the water extract of Eucommia ulmoides leaf (WEE) promotes egg laying in hens, its palatability is poor. To improve the palatability of E. ulmoides leaf, probiotic fermentation was used, and fermented extract E. ulmoides leaf (FEE) was prepared using Lactiplantibacillus plantarum. The safety of FEE was investigated using a long-term toxicity test, and no oxidative damage, inflammatory reactions, or histological lesions were observed in the experimental rats receiving dietary supplementation of FEE at 200 mg/kg, suggesting that FEE is suitable for long-term feeding. Subsequently, dietary supplementation of FEE (group C) in comparison with dietary supplementation of WEE (group B), as well as a control (group A), was applied in the hen industry. Laying performance, egg quality, egg nutrition, egg flavor, and the gut microbiome were analyzed comparatively. Interestingly, the laying rate was observed to be four percentage points higher with dietary supplementation of FEE at 200 mg/kg compared with the control and two percentage points higher compared with the dietary addition of WEE at the same dosage. Simultaneously, a slight upregulation in daily feed consumption was determined in the FEE-supplemented group compared with the blank control and the WEE-supplemented group, indicating that the inclusion of FEE stimulated the hens' appetite. Moreover, variations in egg amino acids, fatty acids, and volatile components were obtained with either dietary addition, FEE or WEE, implying that dietary supplementation of the fermented and water-extracted E. ulmoides leaf extracts contributed to egg flavor change. Furthermore, variations in the gut microbiota were mediated by FEE, increasing the relative abundance of the genus Lactobacillus. These alterations in gut microbiota were tightly related to improved laying performance and egg flavor changes. Our results indicate that FEE is a better alternative feed additive in the hen industry than WEE.

A Large-Scale and Low-Cost Thermoacoustic Loudspeaker Based on Three-Dimensional Graphene Foam.

Graphene is a promising material for thermoacoustic sources due to its extremely low heat capacity per unit area and high thermal conductivity. However, current graphene thermoacoustic devices have limited device area and relatively high cost, which limit their applications of daily use. Here, we adopt a dip-coating method to fabricate a large-scale and cost-effective graphene sound source. This sound source has the three-dimensional (3D) porous structure that can increase the contact area between graphene and air, thus assisting heat to release into the air. In this method, polyurethane (PU) is used as a support, and graphene nanoplates are attached onto the PU skeleton so that a highly flexible graphene foam (GrF) device is obtained. At a measuring distance of 1 mm, it can emit sound at up to 70 dB under the normalized input power of 1 W. Considering its unique porous structure, we establish a thermoacoustic analysis model to simulate the acoustic performance of GrF. Furthermore, the obtained GrF can be made up to 44 in. (100 cm × 50 cm) in size, and it has good flexibility and processability, which broadens the application fields of GrF loudspeakers. It can be attached to the surfaces of objects with different shapes, making it suitable to be used as a large-area speaker in automobiles, houses, and other application scenarios, such as neck mounted speaker. In addition, it can also be widely used as a fully flexible in-ear earphone.

A systematic toxicologic study of polycyclic aromatic hydrocarbons on aquatic organisms via food-web bioaccumulation.

Pollution-induced declines in fishery resources restrict the sustainable development of fishery. As a kind of typical environmental pollutant, the mechanism of polycyclic aromatic hydrocarbons (PAHs) facilitating fishery resources declines needs to be fully illustrated. To determine how PAHs have led to declines in fishery resources, a systematic toxicologic analysis of the effects of PAHs on aquatic organisms via food-web bioaccumulation was performed in the Pearl River and its estuary. Overall, PAH bioaccumulation in aquatic organisms was correlated with the trophic levels along food-web, exhibiting as significant positive correlations were observed between PAHs concentration and the trophic levels of fishes in the Pearl River Estuary. Additionally, waterborne PAHs exerted significant direct effects on dietary organisms (P < 0.05), and diet-borne PAHs subsequently exhibited significant direct effects on fish (P < 0.05). However, an apparent block effect was found in dietary organisms (e.g., zooplankton) where 33.49 % of the total system throughput (TST) was retained at trophic level II, exhibiting as the highest PAHs concentration, bioaccumulation factor (BAF), and biomagnification factor (BMF) of ∑15PAHs in zooplankton were at least eight-fold greater than those in fishes in both the Pearl River and its estuary, thereby waterborne PAHs exerted either direct or indirect effects on fishes that ultimately led to food-web simplification. Regardless of the block effect of dietary organisms, a general toxic effect of PAHs on aquatic organisms was observed, e.g., Phe and BaP exerted lethal effects on phytoplankton Chlorella pyrenoidosa and zooplankton Daphnia magna, and decreased reproduction in fishes Danio rerio and Megalobrama hoffmanni via activating the NOD-like receptors (NLRs) signaling pathway. Consequently, an assembled aggregate exposure pathway for PAHs revealed that increases in waterborne PAHs led to bioaccumulation of PAHs in aquatic organisms along food-web, and this in turn decreased the reproductive ability of fishes, thus causing decline in fishery resources.