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.

Manipulating Crystallographic Orientation via Cross-Linkable Ligand for Efficient and Stable Perovskite Solar Cells.

The crystallographic orientation of polycrystalline perovskites is found to be strongly correlated with their intrinsic properties; therefore, it can be used to effectively enhance the performance of perovskite-based devices. Here, a facile way of manipulating the facet orientation of polycrystalline perovskite films in a controllable manner is reported. By incorporating a cross-linkable organic ligand into the perovskite precursor solution, the crystal orientation disorder can be reduced in the resultant perovskite films to exhibit the prominent (001) orientation with a preferred stacking mode. Moreover, the as-formed low-dimensional perovskites (LDPs) between the organic ligand and the excess lead iodide can passivate the defects around the grain boundaries. Consequently, highly efficient p-i-n structured perovskite solar cells (PSCs) can be made in both rigid and flexible forms from modified perovskites to show high power conversion efficiencies (PCE) of 24.12% and 23.23%, respectively. The devices also exhibit superior long-term stability in a humid environment (with T90  > 1000 h) and under thermal stress (retaining 87% of its initial PCE after 1000 h). More importantly, the ligand enables the derived LDPs to be crosslinked (under 254 nm UV illumination) to demonstrate excellent mechanical bending durability in flexible devices.

π-Expanded Carbazoles as Hole-Selective Self-Assembled Monolayers for High-Performance Perovskite Solar Cells.

Carbazole-derived self-assembled monolayers (SAMs) are promising hole-selective materials for inverted perovskite solar cells (PSCs). However, they often possess small dipoles which prohibit them from effectively modulating the workfunction of ITO substrate, limiting the PSC photovoltage. Moreover, their properties can be drastically affected by even subtle structural modifications, undermining the final PSC performance. Here, we designed two carbazole-derived SAMs, CbzPh and CbzNaph through asymmetric or helical π-expansion for improved molecular dipole moment and strengthened π-π interaction. The helical π-expanded CbzNaph has the largest dipole, forming densely packed and ordered monolayer, facilitated by the highly ordered assembly observed in its π-scaffold's single crystal. These synergistically modulate the perovskite crystallization atop and tune the ITO workfunction. Consequently, the champion PSC employing CbzNaph showed an excellent 24.1 % efficiency and improved stability.

Co-assembled Monolayers as Hole-Selective Contact for High-Performance Inverted Perovskite Solar Cells with Optimized Recombination Loss and Long-Term Stability.

Self-assembled monolayers (SAMs) have been widely employed as an effective way to modify interfaces of electronic/optoelectronic devices. To achieve a good control of the growth and molecular functionality of SAMs, we develop a co-assembled monolayer (co-SAM) for obtaining efficient hole selection and suppressed recombination at the hole-selective interface in inverted perovskite solar cells (PSCs). By engineering the position of methoxy substituents, an aligned energy level and favorable dipole moment can be obtained in our newly synthesized SAM, ((2,7-dimethoxy-9H-carbazol-9-yl) methyl) phosphonic acid (DC-PA). An alkyl ammonium containing SAM is co-assembled to further optimize the surface functionalization and interaction with perovskite layer on top. A champion device with an excellent power conversion efficiency (PCE) of 23.59 % and improved device stability are achieved. This work demonstrates the advantage of using co-SAM in improving performance and stability of PSCs.

Metagenomic analysis of microbial community succession during the pickling process of Zhacai (preserved mustard tuber) and its correlation with Zhacai biochemical indices.

BACKGROUND: Industrial Fuling Zhacai is pickled by a method summarized as 'three times pickled and pressed', in which raw mustard tubers are subjected to three stages of pickling in different salt concentrations, with a pressing operation at the end of each stage to remove brine. This study used Illumina MiSeq technology and multivariate statistical analyses to investigate microbial community succession during the pickling process and its correlation with Zhacai biochemical indices. RESULTS: A total of 19 phyla, 208 genera, and 295 species of bacteria were identified. Lactobacillus was the dominant genus of bacteria in all three stages and Lactobacillus sakei was the dominant species in the first and second stages. A total of six phyla, 200 genera and 301 species of fungi were also identified. According to a PICRUSt2 prediction, the main functions of the bacterial and fungal communities were carbohydrate and protein metabolism, while alcohol metabolism was also a function of fungi. Nine bacterial genera closely correlated with Zhacai biochemical indices: Acinetobacter, Pseudomonas, Pedobacter, Erwinia, Lactobacillus, Chryseobacterium, Flavobacterium, Duganella, and Paenarthrobacter. Six genera of fungi correlated closely: Penicillium, Cystobasidium, Cladosporium, Plenodomus, Aspergillus, and Simplicillium. All these genera probably originated from the surface microorganisms of raw mustard tuber. CONCLUSION: This study reveals the succession patterns of microbial community structures during the pickling process of industrial Zhacai and infers the core functional flora, providing reference data for Zhacai pickling process control. © 2020 Society of Chemical Industry.

Synergistical Dipole-Dipole Interaction Induced Self-Assembly of Phenoxazine-Based Hole-Transporting Materials for Efficient and Stable Inverted Perovskite Solar Cells.

Delicately designed dopant-free hole-transporting materials (HTMs) with ordered structure have become one of the major strategies to achieve high-performance perovskite solar cells (PSCs). In this work, we report two donor-π linker-donor (D-π-D) HTMs, N01 and N02, which consist of facilely synthesized 4,8-di(n-hexyloxy)-benzo[1,2-b:4,5-b']dithiophene as a π linker, with 10-bromohexyl-10H-phenoxazine and 10-hexyl-10H-phenoxazine as donors, respectively. The N01 molecules form a two-dimensional conjugated network governed by C-H⋅⋅⋅O and C-H⋅⋅⋅Br interaction between phenoxazine donors, and synchronously construct a three-dimension lamellar structure with the aid of interlaminar π-π interaction. Consequently, N01 as a dopant-free small-molecule HTM exhibits a higher intrinsic hole mobility and more favorable interfacial properties for hole transport, hole extraction and perovskite growth, enabling an inverted PSC to achieve a very impressive power conversion efficiency of 21.85 %.

Regulating Surface Termination for Efficient Inverted Perovskite Solar Cells with Greater Than 23% Efficiency.

Passivating surface and bulk defects of perovskite films has been proven to be an effective way to minimize nonradiative recombination losses in perovskite solar cells (PVSCs). The lattice interference and perturbation of atomic periodicity at the perovskite surfaces often significantly affect the material properties and device efficiencies. By tailoring the terminal groups on the perovskite surface and modifying the surface chemical environment, the defects can be reduced to enhance the photovoltaic performance and stability of derived PVSCs. Here, we report a rationally designed bifunctional molecule, piperazinium iodide (PI), containing both R2NH and R2NH2+ groups on the same six-membered ring, behaving both as an electron donor and an electron acceptor to react with different surface-terminating ends on perovskite films. The resulting perovskite films after defect passivation show released surface residual stress, suppressed nonradiative recombination loss, and more n-type characteristics for sufficient energy transfer. Consequently, charge recombination is significantly suppressed to result in a high open-circuit voltage (VOC) of 1.17 V and a reduced VOC loss of 0.33 V. A very high power conversion efficiency (PCE) of 23.37% (with 22.75% certified) could be achieved, which is the highest value reported for inverted PVSCs. Our work reveals a very effective way of using rationally designed bifunctional molecules to simultaneously enhance the device performance and stability.

A Cation-Exchange Approach for the Fabrication of Efficient Methylammonium Tin Iodide Perovskite Solar Cells.

Tin-based halide perovskite materials have been successfully employed in lead-free perovskite solar cells, but the overall power conversion efficiencies (PCEs) have been limited by the high carrier concentration from the facile oxidation of Sn2+ to Sn4+ . Now a chemical route is developed for fabrication of high-quality methylammonium tin iodide perovskite (MASnI3 ) films: hydrazinium tin iodide (HASnI3 ) perovskite film is first solution-deposited using presursors hydrazinium iodide (HAI) and tin iodide (SnI2 ), and then transformed into MASnI3 via a cation displacement approach. With the two-step process, a dense and uniform MASnI3 film is obtained with large grain sizes and high crystallization. Detrimental oxidation is suppressed by the hydrazine released from the film during the transformation. With the MASnI3 as light harvester, mesoporous perovskite solar cells were prepared, and a maximum power conversion efficiency (PCE) of 7.13 % is delivered with good reproducibility.

Telbivudine treatment started in early and middle pregnancy completely blocks HBV vertical transmission.

BACKGROUND: To evaluate the efficacy and safety of treating HBV-positive mothers with telbivudine in early and middle pregnancy to prevent mother-to-infant HBV transmission. METHODS: The subject population comprised pregnant women with chronic hepatitis B (CHB; n = 188) from January 2013 to June 2015, with HBV DNA ≥1.0 × 107copies/mL and increased alanine aminotransferase levels. Groups A (n = 62) and B (n = 61) were treated with telbivudine starting at 12 weeks or 20-28 weeks after gestation, respectively. Telbivudine was discontinued at postpartum 12 weeks. Group C (n = 65) received no antiviral. All infants were vaccinated with hepatitis B immunoglobulin (200 IU) and HBV vaccine (20 with hepatitis B The maternal HBV DNA levels of the groups were compared. Mother-to-infant transmission of HBV was indicated by the presence of HBsAg in infants 7 months after birth. RESULTS: Before treatment, the HBV DNA levels of the 3 groups were similar. Before delivery and 12 weeks after delivery, the HBV DNA levels of groups A and B were similar, but both were significantly lower than that of group C (P < 0.01, all). No infants in groups A and B were HBsAg-positive, but the infection rate of group C was 18.4% (P < 0.01). The HBV infection rate of infants was positively associated with the HBV DNA levels of the pregnant mothers. CONCLUSION: Administration of telbivudine to HBV-infected mothers, started during early and middle pregnancy, completely blocked mother-to-infant HBV transmission. TRIAL REGISTRATION: The study was registered retrospectively on Janurary 25 in 2016 at Chinese Clinical Trial Registry ( ChiCTR-OPC-16007899 ).

Using sustained vowels to identify patients with mild Parkinson's disease in a Chinese dataset.

Introduction: Parkinson's disease (PD) is the second most common neurodegenerative disease and affects millions of people. Accurate diagnosis and subsequent treatment in the early stages can slow down disease progression. However, making an accurate diagnosis of PD at an early stage is challenging. Previous studies have revealed that even for movement disorder specialists, it was difficult to differentiate patients with PD from healthy individuals until the average modified Hoehn-Yahr staging (mH&Y) reached 1.8. Recent researches have shown that dysarthria provides good indicators for computer-assisted diagnosis of patients with PD. However, few studies have focused on diagnosing patients with PD in the early stages, specifically those with mH&Y ≤ 1.5. Method: We used a machine learning algorithm to analyze voice features and developed diagnostic models for differentiating between healthy controls (HCs) and patients with PD, and for differentiating between HCs and patients with mild PD (mH&Y ≤ 1.5). The models were independently validated using separate datasets. Results: Our results demonstrate that, a remarkable diagnostic performance of the model in identifying patients with mild PD (mH&Y ≤ 1.5) and HCs, with area under the ROC curve 0.93 (95% CI: 0.851.00), accuracy 0.85, sensitivity 0.95, and specificity 0.75. Conclusion: The results of our study are helpful for screening PD in the early stages in the community and primary medical institutions where there is a lack of movement disorder specialists and special equipment.

Effects of sodium lauryl sulfate and postbiotic toothpaste on oral microecology.

The diversity and delicate balance of the oral microbiome contribute to oral health, with its disruption leading to oral and systemic diseases. Toothpaste includes elements like traditional additives such as sodium lauryl sulfate (SLS) as well as novel postbiotics derived from probiotics, which are commonly employed for maintaining oral hygiene and a healthy oral cavity. However, the response of the oral microbiota to these treatments remains poorly understood. In this study, we systematically investigated the impact of SLS, and toothpaste containing postbiotics (hereafter, postbiotic toothpaste) across three systems: biofilms, animal models, and clinical populations. SLS was found to kill bacteria in both preformed biofilms (mature biofilms) and developing biofilms (immature biofilms), and disturbed the microbial community structure by increasing the number of pathogenic bacteria. SLS also destroyed periodontal tissue, promoted alveolar bone resorption, and enhanced the extent of inflammatory response level. The postbiotic toothpaste favored bacterial homeostasis and the normal development of the two types of biofilms in vitro, and attenuated periodontitis and gingivitis in vivo via modulation of oral microecology. Importantly, the postbiotic toothpaste mitigated the adverse effects of SLS when used in combination, both in vitro and in vivo. Overall, the findings of this study describe the impact of toothpaste components on oral microflora and stress the necessity for obtaining a comprehensive understanding of oral microbial ecology by considering multiple aspects.

Current State and Future Perspectives of Printable Organic and Perovskite Solar Cells.

Photovoltaic technology presents a sustainable solution to address the escalating global energy consumption and a reliable strategy for achieving net-zero carbon emissions by 2050. Emerging photovoltaic technologies, especially the printable organic and perovskite solar cells, have attracted extensive attention due to their rapidly transcending power conversion efficiencies and facile processability, providing great potential to revolutionize the global photovoltaic market. To accelerate these technologies to translate from the laboratory scale to the industrial level, it is critical to develop well-defined and scalable protocols to deposit high-quality thin films of photoactive and charge-transporting materials. Herein, the current state of printable organic and perovskite solar cells is summarized and the view regarding the challenges and prospects toward their commercialization is shared. Different printing techniques are first introduced to provide a correlation between material properties and printing mechanisms, and the optimization of ink formulation and film-formation during large-area deposition of different functional layers in devices are then discussed. Engineering perspectives are also discussed to analyze the criteria for module design. Finally, perspectives are provided regarding the future development of these solar cells toward practical commercialization. It is believed that this perspective will provide insight into the development of printable solar cells and other electronic devices.

Clinical evidence of the efficacy and safety of a new multi-peptide anti-aging topical eye serum.

BACKGROUND: Skin aging is a complex multifactorial progressive process. With age, intrinsic and extrinsic factors cause the loss of skin elasticity, with the formation of wrinkles, resulting in skin sagging through various pathways. A combination of multiple bioactive peptides could be used as a treatment for skin wrinkles and sagging. OBJECTIVES: This study aimed to evaluate the cosmetic efficacy of a multi-peptide eye serum as a daily skin-care product for improving the periocular skin of women within the ages of 20-45 years. METHODS: The stratum corneum skin hydration and skin elasticity were assessed using a Corneometer CM825 and Skin Elastometer MPA580, respectively. The PRIMOS CR technique based on digital strip projection technology was used for skin image and wrinkle analysis around the "crow's feet" area. Self-assessment questionnaires were filled on Day 14 and 28 of product use. RESULTS: This study included 32 subjects with an average age of 28.5 years. On Day 28, there was a significant decrease in the number, depth, and volume of wrinkles. Skin hydration, elasticity, and firmness increased continuously during the study period, consistent with typical anti-aging claims. A majority of the participants (75.00%) expressed overall satisfaction with their skin appearance after using the product. Most participants noted a visible skin improvement, with an increase in skin elasticity and smoothness, and confirmed the extensibility, applicability, and temperance of the product. No adverse reactions related to product use were observed. CONCLUSIONS: The multi-peptide eye serum uses a multi-targeted mechanism against skin aging to improve the skin appearance, making it an ideal choice for daily skincare.

Intestinal Microecology of Mice Exposed to TiO2 Nanoparticles and Bisphenol A.

Exposure to titanium dioxide nanoparticles (TiO2 NPs) and bisphenol A (BPA) is ubiquitous, especially through dietary and other environmental pathways. In the present study, adult C57BL/6J mice were exposed to TiO2 NPs (100 mg/kg), BPA (0, 5, and 50 mg/kg), or their binary mixtures for 13 weeks. The 16S rDNA amplification sequence analysis revealed that co-exposure to TiO2 NPs and BPA altered the intestinal microbiota; however, this alteration was mainly caused by TiO2 NPs. Faecal metabolomics analysis revealed that 28 metabolites and 3 metabolic pathways were altered in the co-exposed group. This study is the first to reveal the combined effects of TiO2 NPs and BPA on the mammalian gut microbial community and metabolism dynamics, which is of great value to human health. The coexistence of TiO2 NPs and BPA in the gut poses a potential health risk due to their interaction with the gut microbiota.

[Advance of in vitro oral static biofilm model].

Oral static biofilm model is an important tool for in vitro simulation of oral microecological environment, which has become an important method for studying the pathogenesis of various oral diseases and testing the efficacy of various drugs, oral care products and foods due to its low cost, high throughput, good reliability and easy operation. The establishment of oral static biofilm models allows the selection of different devices, inoculum sources, media, substrates and culture conditions according to the purpose of the study, and the evaluation of biofilm growth by various methods such as measuring biomass, metabolic activity, community structure and performing visualization analysis. This paper summarizes the methodological elements reported in recent years for the establishment and evaluation of oral static biofilm models, and analyzes and discusses the applicability of various methods in the hope of contributing to the research and production practice in related fields.

ß-Hydroxybutyrate alleviates pyroptosis in MPP+/MPTP-induced Parkinson's disease models via inhibiting STAT3/NLRP3/GSDMD pathway.

BACKGROUND: Parkinson's disease (PD) is a common neurodegenerative disease characterized by motor symptoms and non-motor symptoms, and affects millions of people worldwide. Growing evidence implies ß-Hydroxybutyrate (BHB), one of the ketone bodies generated by ketogenesis, plays a neuroprotective role in neurodegenerative diseases. We aimed to verify the anti-inflammatory effect of BHB on PD and further explore potential molecular mechanisms. METHODS: We performed the experiments on 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mice model in vivo and 1-methyl-4-phenylpyridinium (MPP+)-simulated BV2 cell model in vitro, with or without BHB pretreatment. Motor function was assessed by pole test, forced swimming test, traction test and open field test. Immunofluorescence was used to evaluate the loss of dopaminergic neurons and glial cell activation in MPTP-induced PD model mice. The expression of the STAT3/NLRP3/GSDMD signal pathway was measured by western blots. Proinflammatory cytokines was assessed by enzyme-linked immunosorbent assay (ELISA). RESULTS: BHB treatment reversed motor deficits, loss of dopaminergic neurons and glial cell activation in PD mice induced by MPTP. Moreover, BHB inhibited microglia pyroptosis by negatively regulating STAT3/NLRP3/GSDMD signal pathway, resulting in downregulation of proinflammatory cytokines (IL-1ß and IL-18) in vivo and vitro. CONCLUSION: These data suggested BHB supplement inhibited pyroptosis by down-regulating STAT3-mediated NLRP3 inflammasome activation for PD models in vivo and in vitro. Our findings provided novel insights and available interventions for the prevention and treatment of PD, and highlighted pyroptosis as a potential therapeutic target for PD.

Perovskite-Inspired Lead-Free Ag2BiI5 for Self-Powered NIR-Blind Visible Light Photodetection.

In recent years, solution-processible semiconductors with perovskite or perovskite-inspired structures have been extensively investigated for optoelectronic applications. In particular, silver-bismuth-halides have been identified as especially promising because of their bulk properties and lack of heavily toxic elements. This study investigates the potential of Ag2BiI5 for near-infrared (NIR)-blind visible light photodetection, which is critical to emerging applications (e.g., wearable optoelectronics and the Internet of Things). Self-powered photodetectors were realized and provided a near-constant ≈ 100 mA W-1 responsivity through the visible, a NIR rejection ratio of > 250, a long-wavelength responsivity onset matching standard colorimetric functions, and a linear photoresponse of > 5 orders of magnitude. The optoelectronic characterization of Ag2BiI5 photodetectors additionally revealed consistency with one-center models and the role of the carrier collection distance in self-powered mode. This study provides a positive outlook of Ag2BiI5 toward emerging applications on low-cost and low-power NIR-blind visible light photodetector.

In Situ Deposition of CuBiS2 on Mesoporous TiO2 Film for Light Absorber in Solar Cells.

In this report, emplectite (CuBiS2) semiconductor has been deposited on mesoporous TiO2 using gas-solid reaction method. For the first time, CuCl2 and BiCl3 are solution-coated on mesoporous TiO2 films, and thereafter reacted with H2S gas in an H2S atmosphere. The CuBiS2 film is further confirmed using X-ray diffraction; thus, demonstrating the pure phase of CuBiS2. CuBiS2 film shows high spectral absorption with an energy gap (Eg) of 2.18 eV. Furthermore, devices have a structure consisting of FTO/compact-TiO2/mesoporous-TiO2/CuBiS2/P3HT/Ag have been fabricated and hence exhibit high photoresponse performance.

Efficacy and safety of telbivudine treatment for the prevention of HBV perinatal transmission.

To observe the efficacy of telbivudine in chronic hepatitis B (CHB) women with high viral load during pregnancy and the long-term effects on intelligence, growth, and development of the newborns.A total of 87 patients were included. Forty-two patients received telbivudine orally 600 mg per day and treatment initiated from 12 weeks after gestation until the 12th postpartum week. Forty-five patients were untreated according to principle of informed consent. All infants received injection of hepatitis B immune globulin (HBIG; 200 IU) and were vaccinated with recombinant HBV vaccine. Wechsler preschool intelligence scale was used to assess mental and neuropsychological developments of these children till they were 6 years old. Data including serum HBV DNA viral load, Apgar score, and scores of Wechsler preschool intelligence scale were analyzed and compared.Levels of both serum HBV DNA and ALT in patients who received telbivudine were significantly decreased at the 12th week after delivery, compared with baseline levels (P < .01). No significant changes were observed in patients not receiving telbivudine (P > .05). Serum HBV DNA and ALT levels at the 12th week after delivery in the telbivudine group were significantly lower than those of patients without telbivudine (P < .01). The serum HBsAg-positive rate in neonates 7 months of age was 0%, which was significantly lower than that in control group (11.11%) (P < .05). No statistical differences were observed between the 2 groups regarding maternal cesarean section rate, adverse pregnancy rate, postpartum bleeding rate, neonatal body mass, Apgar score, neonatal malformation incidence, or intelligence development of newborn.Telbivudine is effective to reduce the viral load in CHB mothers with high viral load and could lower the perinatal transmission rate. Both mental and physical development in neonates with exposure to telbivudine during perinatal period were similar to those without telbivudine exposure.

Ambipolar Deep-Subthreshold Printed-Carbon-Nanotube Transistors for Ultralow-Voltage and Ultralow-Power Electronics.

The development of ultralow-power and easy-to-fabricate electronics with potential for large-scale circuit integration (i.e., complementary or complementary-like) is an outstanding challenge for emerging off-the-grid applications, e.g., remote sensing, "place-and-forget", and the Internet of Things. Herein we address this challenge through the development of ambipolar transistors relying on solution-processed polymer-sorted semiconducting carbon nanotube networks (sc-SWCNTNs) operating in the deep-subthreshold regime. Application of self-assembled monolayers at the active channel interface enables the fine-tuning of sc-SWCNTN transistors toward well-balanced ambipolar deep-subthreshold characteristics. The significance of these features is assessed by exploring the applicability of such transistors to complementary-like integrated circuits, with respect to which the impact of the subthreshold slope and flatband voltage on voltage and power requirements is studied experimentally and theoretically. As demonstrated with inverter and NAND gates, the ambipolar deep-subthreshold sc-SWCNTN approach enables digital circuits with complementary-like operation and characteristics including wide noise margins and ultralow operational voltages (≤0.5 V), while exhibiting record-low power consumption (≤1 pW/µm). Among thin-film transistor technologies with minimal material complexity, our approach achieves the lowest energy and power dissipation figures reported to date, which are compatible with and highly attractive for emerging off-the-grid applications.