Search

In the development of high‐performance organic solar cells (OSCs), the self‐organization of organic semiconductors plays a crucial role. This study focuses on the precisely manipulation of molecular assemble via tuning alkyl side‐chain topology in a series of low‐cost nonfused‐ring electron acceptors (NFREAs). Among the three NFREAs investigated, DPA‐4, which possesses an asymmetric alkyl side‐chain length, exhibits a tight packing in the crystal and high crystallinity in the film, contributing to improved electron mobility and favorable film morphology for DPA‐4. As a result, the OSC device based on DPA‐4 achieves an excellent power conversion efficiency of 16.67 %, ranking among the highest efficiencies for NFREA‐based OSCs. [ABSTRACT FROM AUTHOR]

In the development of high‐performance organic solar cells (OSCs), the self‐organization of organic semiconductors plays a crucial role. This study focuses on the precisely manipulation of molecular assemble via tuning alkyl side‐chain topology in a series of low‐cost nonfused‐ring electron acceptors (NFREAs). Among the three NFREAs investigated, DPA‐4, which possesses an asymmetric alkyl side‐chain length, exhibits a tight packing in the crystal and high crystallinity in the film, contributing to improved electron mobility and favorable film morphology for DPA‐4. As a result, the OSC device based on DPA‐4 achieves an excellent power conversion efficiency of 16.67 %, ranking among the highest efficiencies for NFREA‐based OSCs. [ABSTRACT FROM AUTHOR]

Organic solar cells (OSCs) have attracted extensive attention from both academia and industry in recent years due to their remarkable improvement in power conversion efficiency (PCE). However, the Golden Triangle (the balance of efficiency‐stability‐cost) required for large‐scale industrialization of OSCs still remains a great challenge. Here, a new nonfused‐ring electron acceptor (NFREA) BF and its polymerized counterpart PBF were designed and synthesized, and their photovoltaic performance, storage stability and material cost were systematically investigated. When blended with a widely‐used polymer donor PBDB‐T, the PBF‐based all‐polymer solar cell (all‐PSC) displayed a record high PCE of 12.61% for polymerized NFREAs (PNFREAs) with an excellent stability (95.2% of initial PCE after 800 h storage), superior to the BF counterpart. Impressively, PBF‐based all‐PSC possesses the highest industrial figure‐of‐merit (i‐FOM) value of 0.309 based on an efficiency‐stability‐cost evaluation, in comparison to several representative OSC systems (such as PM6:Y6 and PBDB‐T:PZ1). This work provides an insight into the balance of efficiency, stability, and cost, and also indicates that the PNFREAs are promising materials toward the commercial application of OSCs. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: By employing thiazole and 4‐chlorothiazole as the A′ units, two A‐D‐A′‐D‐A type nonfused‐ring electron acceptors (NFREAs) Tz‐H and Tz‐Cl were designed and synthesized. Replacing thiazole in Tz‐H with 4‐chlorothiazole can not only remarkably shorten the synthetic route through C—H direct arylation but also enhance molecular planarity with the simultaneous incorporation of S···N and S···Cl noncovalently conformational locks (NoCLs). The photovoltaic devices based on PM6:Tz‐Cl exhibited a power conversion efficiency as high as 11.10%, much higher than that of PM6:Tz‐H (6.41%), mainly due to more efficient exciton dissociation, better and more balanced carrier mobility, less charge recombination, and more favorable morphology. These findings demonstrate the great potential of NoCLs in achieving low‐cost and high‐performance NFREAs. [ABSTRACT FROM AUTHOR]

Background Few studies have investigated psychogenic sexual dysfunction including psychogenic erectile dysfunction (pED); the effect of tadalafil on sexual behavior of male rats induced by chronic unpredictable mild stress (CUMS) remains unclear. Aim The aim was to explore the influence of CUMS on sexual behavior of male rats and the effects of tadalafil on that. Methods Adult male rats were divided into 3 groups, including the normal group without CUMS, the model group with 6 weeks' CUMS, and the tadalafil group with treatment of tadalafil during CUMS. CUMS consists of water deprivation, food deprivation, stroboscopic lightning, white noise, cage tilting, weeding packing, and housing 2 unfamiliar rats. The apomorphine test and vaginal smear test were conducted with the aim to screen out male rats with good erectile function and make preparation for the sexual behavior test, respectively. Outcomes At the end of the study period, the level of anhedonia and sexual function were evaluated by the sucrose preference test, sexual behavior test, and measurement of serum testosterone, dopamine, and 5-HT. Results Sucrose preference showed significant decrease in rats after CUMS. The intromission ratio and total intromission frequency decreased significantly, while the mount latency and ejaculation latency prolonged significantly in CUMS-induced rats when compared with normal rats. Meanwhile, the treatment of tadalafil reversed the level of anhedonia and sexual function in CUMS-induced rats. However, there were no statistical differences in the levels of serum testosterone, dopamine, and 5-HT among groups. Clinical Implications The study constructed an animal model that can provide clinical insights into the mechanism of psychogenic sexual dysfunction and supports the application of tadalafil in pED therapy. Strengths and Limitations We found that CUMS-induced rats exhibited anhedonia and poor sexual function that could be prevented by tadalafil administration. Future research needs to construct the standard of pED model and explore the mechanism of tadalafil on central nervous system. Conclusion Tadalafil could prevent the changes of depression and poor sexual function in rats induced by CUMS, and the method of CUMS and the sexual behavior test should be used in the future for pED modeling. [ABSTRACT FROM AUTHOR]

Many breakthroughs on security and privacy-preserving techniques have emerged to mitigate the trust loss of cloud hosting environment caused by various types of attacks. To enhance memory-level security of multi-keyword fuzzy search, a widely occurred query request, we take the initiative to apply Trusted Execution Environment (a.k.a TEE) technology to our protocol design which provides hardware-based tamper-proof enclaves. Then we propose the Edit Distance-based Obfuscation Mechanism to further protect the query process executed outside TEE against access pattern leakage. With concerns of practicality and performance, we also propose the two-layer fuzzy index structure and Trend-aware Cache. The former addresses the space limitation of TEE memory for searching large datasets, while the latter optimizes the cache utility of TEE with trend-aware coordinator to effectively reduce the communication overhead. [ABSTRACT FROM AUTHOR]

Creep, sulfate erosion resistance, fly ash content of concrete, and sustained compression load are important factors that will affect the long-term performance of concrete. It is of great interest to combine these effects together to make a comprehensive investigation of fly ash concrete. However, the concrete creep under both sustained compression load and sulfate attack conditions has rarely been reported. To obtain the creep characteristics of fly ash concrete in a sulfate environment, this paper first finishes the creep experiments of fly ash concrete under sustained compression load and sulfate attack. The test factors include the load stress level, the concentration of sulfate solution, and the content of fly ash. Based on the creep mechanism of fly ash concrete under sulfate erosion, the relationship between time-dependent section area variation and creep was carried out. After comparing different creep models, the creep calculation model of fly ash concrete under sulfate erosion was built via the B4 model combined with the cross-sectional area of the damaged layer and undamaged layer of concrete. Finally, comparing the calculated values with the test results, the calculated results were in good agreement with the test data, which is of practical significance to the practical engineering application and the improvement of structural reliability. [ABSTRACT FROM AUTHOR]

The polymerization of fused-ring acceptors (FRAs) to afford their corresponding polymeric acceptors for high-performance all-polymer solar cells (all-PSCs) has achieved remarkable progress in the past few years. However, due to the high degree of synthetic complexity for the monomer, the high-cost of these polymeric acceptors may limit their commercial applications. Thus, it is urgent to develop inexpensive and high-performance polymeric acceptors for all-PSCs. Herein, two novel polymeric acceptors (PBTzO and PBTzO-2F) have been designed and synthesized by copolymerization of noncovalently fused ring acceptors (NFRAs), which were employed in all-PSCs for the first time. Upon introducing the "noncovalently conformational locks (NoCLs)" in the backbone and selective fluorination of the end-group, photophysical and electrical properties, and solid-state packing properties of the NFRAs have been rationally tuned. As a result, the PBDB-T:PBTzO-2F based devices presented an excellent power conversion efficiency (PCE) of 11.04%, much higher than that of PBTzO based ones due to the increased charge generation and extraction, improved hole transfer and carrier mobilities, and reduced energy loss. More importantly, PBTzO-2F exhibited a much lower synthetic complexity (SC) index and higher figure-of-merit (FOM) values than the highperformance fused-ring acceptor based polymer acceptors (FRA-PAs) due to the simpler structures and more effective synthesis. This contribution provided a novel idea to achieve low-cost and high-performance all-PSCs. [ABSTRACT FROM AUTHOR]

Background: This study aimed to investigate the safety and efficacy of minimally invasive total mesoesophageal excision (TME) for esophageal cancer.Methods: We retrospectively collected data from patients with esophageal cancer who underwent esophagectomy at our center between January 2011 and June 2017. Among 611 eligible patients, 302 underwent minimally invasive total mesoesophageal excision (the TME group) and 309 underwent non-total mesoesophageal excision (the NME group). Outcomes were compared after 1-to-1 propensity score matching, and subgroup analyses were performed for cases involving pT1-2 or pT3-4a disease.Results: The propensity score matching produced 249 pairs of patients. The TME group had a shorter operative time (P < 0.001), lower intraoperative bleeding (P < 0.001), and a shorter postoperative hospital stay (P < 0.001). There were no significant differences between the two groups in the number of removed lymph nodes, 30-day mortality, or postoperative complications. In addition, both groups had similar 3-year rates of overall survival (OS) and disease-free survival (DFS). However, the 3-year recurrence rate in the esophageal bed was significantly lower in the TME group (P = 0.033). Furthermore, among patients with pT3-4a disease, the TME group had better 3-year rates of OS, DFS, and recurrence.Conclusion: Minimally invasive total mesoesophageal excision appears to be a safe technique that can reduce tumor recurrence in the esophageal bed. Furthermore, this technique provided survival benefits for patients with pT3-4a disease. [ABSTRACT FROM AUTHOR]

With the rapid development of deep learning, the performance on facial expression recognition (FER) has been greatly improved. However, multi-view FER, where the facial information is difficult to be fully acquired due to pose deflections, remains challenging. This paper presents a generative adversarial network (GAN) based three-stage-training algorithm for multi-view FER. Specifically, the frontal-view faces are firstly adopted to train a convolutional neural network (CNN) in an efficient way. Then, the pre-trained CNN is embedded in a well-designed GAN such that the faces with different deflections can be synthesized as the frontal-view ones containing expression features. The original and synthesized faces are finally fused and employed to retrain the CNN classifier such that the multi-view FER problem is efficiently resolved. Experimental results demonstrate that the three-stage-training algorithm can achieve better performance than some existing methods. [ABSTRACT FROM AUTHOR]

Aim: To assess the exosomal miR‐21/Let‐7a ratio, a noninvasive method, in distinguishing non‐small cell lung cancer (NSCLC) from benign pulmonary diseases. Methods: The exosomes were extracted from the peripheral blood serum using serum exosomal extraction kit. miR‐21 and Let‐7a levels were evaluated by quantitative reverse transcription polymerase chain reaction. Results: We found that miR‐21/Let‐7a ratio of NSCLC patients was significantly higher than that of healthy people, patients with pulmonary inflammation diseases, and benign pulmonary nodules, respectively. Receiver‐operating characteristic analysis revealed that as compared with healthy controls, miR‐21/Let‐7a produced the area under the curve (AUC) at 0.8029 in patients with NSCLC, which helped to distinguish NSCLC from healthy controls with 81.33% sensitivity and 69.57% specificity. In addition, the AUC of miR‐21/Let‐7a in NSCLC patients was 0.8196 in comparison to patients with pulmonary inflammation diseases. Meanwhile, the sensitivity and specificity were 56.00% and 100%, respectively. Furthermore, compared with patients with benign pulmonary nodules, the AUC of miR‐21/Let‐7a in NSCLC patients was 0.7539. The sensitivity and specificity were 56.00% and 82.61%, respectively. Conclusion: In the present study, our findings revealed that exosomal miR‐21/Let‐7a ratio holds considerable promise as a noninvasive biomarker for the diagnosis of NSCLC from benign pulmonary diseases. [ABSTRACT FROM AUTHOR]

The growing number of mobile and IoT devices has nourished many intelligent applications. In order to produce high-quality machine learning models, they constantly access and collect rich personal data such as photos, browsing history, and text messages. However, direct access to personal data has raised increasing public concerns about privacy risks and security breaches. To address these concerns, there are two emerging solutions to privacy-preserving machine learning, namely local differential privacy and federated machine learning. The former is a distributed data collection strategy where each client perturbs data locally before submitting to the server, whereas the latter is a distributed machine learning strategy to train models on mobile devices locally and merge their output (e.g., parameter updates of a model) through a control protocol. In this article, we conduct a comparative study on the efficiency and privacy of both solutions. Our results show that in a standard population and domain setting, both can achieve an optimal misclassification rate lower than 20% and federated machine learning generally performs better at the cost of higher client CPU usage. Nonetheless, local differential privacy can benefit more from a larger client population ($>$> 1k). As for privacy guarantee, local differential privacy also has flexible control over the data leakage. [ABSTRACT FROM AUTHOR]

We propose a germanium (Ge) photonic crystal thin slab to achieve perfect absorption efficiency in telecom band. The maximum absorption is increased 14-fold compared to a planar cell with the same thickness at normal incidence. The absorption enhancement is attributed to the critical coupling with guided resonances by introducing an airhole photonic crystal on the thin slab. This novel design constitutes an important step towards high responsivity and high-speed photodetection with strong energy harvesting. [ABSTRACT FROM AUTHOR]

Near-infrared perfect wave harvesting of graphene is theoretically and numerically obtained in a hybrid dielectric configuration without assistance of a reflecting mirror. The absorption is increased 43-fold compared to a suspended graphene layer at normal incidence. The mechanism of perfect absorption is based on critical coupling with a guided resonance introduced by a silicon bar array and Fabry–Perot (FP) effect of a silicon oxide layer. This lossless design is expected to find applications to allow the active area with effective generation and fast transport of photocarriers, paving a new way for on-chip small-footprint ultrahigh responsivity and ultrahigh-speed photodetection in silicon photonics. [ABSTRACT FROM AUTHOR]

This article discusses the challenge of industrializing organic solar cells and the need to balance efficiency, stability, and cost. The authors present a polymer acceptor called PBF, which was created using a polymerized nonfused-ring electron acceptor strategy. This polymer acceptor achieved a high efficiency of 12.61%, excellent stability, and low cost, making it a promising option for industrial applications. The authors compare the performance of PBF to other reputable systems and highlight its superior figure-of-merit. [Extracted from the article]

A novel approach to investigate the assembly and fabrication method for Indium Arsenide nanowires nano devices. Assembly of InAs nanowires field-effect transistor (FET) was realized by dielectrophoresis approach. Before deposition of the contacts, InAs nanowires were treated wet etching in an ammonium polysulfide ((NH4)2Sx) solution to remove a surface oxide layer. The assembled devices were characterized by atomic force microscopy. The experimental results showed that the efficient assembly of InAs nanowires was obtained when the applied alternating current voltage has a frequency of 2MHz and an amplitude of 10V, and the success rate of ideal assembly for InAs nanowires FET had been assessed. Meanwhile, it also provided an effective assembly method for other one-dimensional nanomaterials assembly of nano devices. [ABSTRACT FROM AUTHOR]