Precise Control of Crystallization and Phase-Transition with Green Anti-Solvent in Wide-Bandgap Perovskite Solar Cells with Open-Circuit Voltage Exceeding 1.25 V.

Wide-bandgap perovskite solar cells (PSCs) have attracted a lot of attention due to their application in tandem solar cells. However, the open-circuit voltage (VOC ) of wide-bandgap PSCs is dramatically limited by high defect density existing at the interface and bulk of the perovskite film. Here, an anti-solvent optimized adduct to control perovskite crystallization strategy that reduces nonradiative recombination and minimizes VOC deficit is proposed. Specifically, an organic solvent with similar dipole moment, isopropanol (IPA) is added into ethyl acetate (EA) anti-solvent, which is beneficial to form PbI2 adducts with better crystalline orientation and direct formation of α-phase perovskite. As a result, EA-IPA (7-1) based 1.67 eV PSCs deliver a power conversion efficiency of 20.06% and a VOC of 1.255 V, which is one of the remarkable values for wide-bandgap around 1.67 eV. The findings provide an effective strategy for controlling crystallization to reduce defect density in PSCs.

Lipid and metabolic alteration involvement in physiotherapy for chronic nonspecific low back pain.

BACKGROUND: Chronic nonspecific low back pain (cNLBP) is a common health problem worldwide, affecting 65-80% of the population and greatly affecting people's quality of life and productivity. It also causes huge economic losses. Manual therapy (MT) and therapeutic exercise (TE) are effective treatment options for cNLBP physiotherapy-based treatment. However, the underlying mechanisms that promote cNLBP amelioration by MT or TE are incompletely understood. METHODS: Seventeen recruited subjects were randomly divided into an MT group and a TE group. Subjects in the MT group performed muscular relaxation, myofascial release, and mobilization for 20 min during each treatment session. The treatment lasted for a total of six sessions, once every two days. Subjects in the TE group completed motor control and core stability exercises for 30 min during each treatment session. The motor control exercise included stretching of the trunk and extremity muscles through trunk and hip rotation and flexion training. Stabilization exercises consisted of the (1) bridge exercise, (2) single-leg-lift bridge exercise, (3) side bridge exercise, (4) two-point bird-dog position with an elevated contralateral leg and arm, (5) bear crawl exercise, and (6) dead bug exercise. The treatment lasted for a total of six sessions, with one session every two days. Serum samples were collected from subjects before and after physiotherapy-based treatment for lipidomic and metabolomic measurements. RESULTS: Through lipidomic analysis, we found that the phosphatidylcholine/phosphatidylethanolamine (PC/PE) ratio decreased and the sphingomyelin/ceramide (SM/Cer) ratio increased in cNLBP patients after MT or TE treatment. In addition, eight metabolites enriched in pyrimidine and purine differed significantly in cNLBP patients who received MT treatment. A total of nine metabolites enriched in pyrimidine, tyrosine, and galactose pathways differed significantly in cNLBP patients after TE treatment during metabolomics analysis. CONCLUSION: Our study was the first to elucidate the alterations in the lipidomics and metabolomics of cNLBP physiotherapy-based treatment and can expand our knowledge of cNLBP physiotherapy-based treatment.

Crystal Size Effect on Carrier Transport of Microscale Perovskite Junctions via Soft Contact.

To reduce the size of optoelectronic devices, it is essential to understand the crystal size effect on the carrier transport through microscale materials. Here, we show a soft contact method to probe the properties of irregularly shaped microscale perovskite crystals by employing a movable liquid metal electrode to form a self-adaptative deformable electrode-perovskite-electrode junction. Accordingly, we demonstrate that (1) the photocurrents of perovskite quantum dot films and microplatelets show profound differences regarding both the on/off ratio and the response time upon light illumination; and (2) small-size perovskite (<50 µm) junctions may show negative differential resistance (NDR) behavior, whereas the NDR phenomenon is absent in large-size perovskite junctions within the same bias regime. Our studies provide a method for studying arbitrary-shaped crystals without mechanical damage, assisting the understanding of the photogenerated carriers transport through microscale crystals.

Quasi-Heteroface Perovskite Solar Cells.

Perovskite solar cells (PSCs) have attracted unprecedented attention due to their rapidly rising photoelectric conversion efficiency (PCE). In order to further improve the PCE of PSCs, new possible optimization path needs to be found. Here, quasi-heteroface PSCs (QHF-PSCs) is designed by a double-layer perovskite film. Such brand new PSCs have good carrier separation capabilities, effectively suppress the nonradiative recombination of the PSCs, and thus greatly improve the open-circuit voltage and PCE. The root cause of the performance improvement is the benefit from the additional built-in electric field, which is confirmed by measuring the external quantum efficiency under applied electric field and Kelvin probe force microscope. Meanwhile, an intermediate band gap perovskite layer can be obtained simply by combining a wide band gap perovskite layer with a narrow band gap perovskite layer. Tunability of the band gap is obtained by varying the film thicknesses of the narrow and wide band gap layers. This phenomenon is quite different from traditional inorganic solar cells, whose band gap is determined only by the narrowest band gap layer. It is believed that these QHF-PSCs will be an effective strategy to further enhance PCE in PSCs and provide basis to further understand and develop the perovskite materials platform.

X-ray crystal structure of putative transcription regulator lmo2088 from Listeria monocytogenes.

Listeria monocytogenes is a gram-positive food borne pathogen. The lmo2088 belongs to the TetR family of transcriptional regulators from L. monocytogenes. These transcriptional factors regulate multidrug resistance transporters in L. monocytogenes. Here, we report native protein crystal structure of lmo2088 at a resolution of 1.7 Å. Lmo2088 comprises of an N-terminal DNA binding domain and a variable C-terminal effector binding domain. Furthermore, we identified specific consensus sequences selected by systematic evolution of ligands by exponential enrichment in vitro. The specific binding of lmo2088 with DNA consensus sequence was validated by electrophoretic mobility shift assay, fluorescence polarization and isothermal titration calorimetry. We speculate that the structure of lmo2088 might provide an insight into the regulatory function of lmo2088 of L. monocytogenes.

Molecular mechanism of divalent-metal-induced activation of NS3 helicase and insights into Zika virus inhibitor design.

Zika virus has attracted increasing attention because of its potential for causing human neural disorders, including microcephaly in infants and Guillain-Barré syndrome. Its NS3 helicase domain plays critical roles in NTP-dependent RNA unwinding and translocation during viral replication. Our structural analysis revealed a pre-activation state of NS3 helicase in complex with GTPγS, in which the triphosphate adopts a compact conformation in the absence of any divalent metal ions. In contrast, in the presence of a divalent cation, GTPγS adopts an extended conformation, and the Walker A motif undergoes substantial conformational changes. Both features contribute to more extensive interactions between the GTPγS and the enzyme. Thus, this study provides structural evidence on the allosteric modulation of MgNTP2- on the NS3 helicase activity. Furthermore, the compact conformation of inhibitory NTP identified in this study provides precise information for the rational drug design of small molecule inhibitors for the treatment of ZIKV infection.

Structure of the NS5 methyltransferase from Zika virus and implications in inhibitor design.

Recent outbreak of flavivirus Zika virus (ZIKV) in America has urged the basic as well as translational studies of this important human pathogen. The nonstructural protein 5 (NS5) of the flavivirus has an N-terminal methyltransferase (MTase) domain that plays critical roles in viral RNA genome capping. The null mutant of NS5 MTase is lethal for virus. Therefore, NS5 is a potential drug target for the treatment of Zika virus infection. In this study, we determined crystal structures of the ZIKV MTase in complex with GTP and RNA cap analogue 7meGpppA. Structural analyses revealed highly conserved GTP/cap-binding pocket and S-adenosylmethionine (SAM)-binding pocket. Two conformations of the second base of the cap were identified, which suggests the flexibility of RNA conformation. In addition, the ligand-binding pockets identified a continuous region of hotspots suitable for drug design. Docking calculation shows that the Dengue virus inhibitor compound 10 may bind to the ZIKV MTase.

RBF neural network dynamic sliding mode control based on lambert W function for piezoelectric stick-slip actuator.

This paper presents a novel approach for increasing the precision of high-precision positioning control experiments for a piezoelectric stick-slip actuator system. This is achieved through dynamic sliding mode control with a radial basis function neural network (RBFNN) based on the Lambert W function. The proposed control strategy is divided into two parts: scanning mode control and stepping mode control. For scanning control, a dynamic sliding mode controller was designed to solve the jitter problem in traditional sliding mode control. The introduction of the RBFNN avoids the effects of uncertainty terms and unknown disturbances in the model; reduces the controller gain, which must be adjusted; and improves the robustness of the system to disturbances. The stability of the dynamic sliding mode controller based on the RBFNN was verified through a Lyapunov analysis, and the Lambert W function was introduced to optimize the controller parameters responsible for the time lag in the closed-loop control system. This optimization improved the system's robustness against time delays, which can adversely affect its performance. Simulation and experimental results indicated that the proposed control strategy achieved a positioning control accuracy of <40 nm during the scanning phase and was robust in the presence of a load. In long-distance positioning control experiments, the control strategy achieved a control target of 40 µm while maintaining the positioning control accuracy and reducing the impact of time lag on the system.

Kyasanur Forest disease virus NS3 helicase: Insights into structure, activity, and inhibitors.

Kyasanur Forest disease virus (KFDV), a tick-borne flavivirus prevalent in India, presents a serious threat to human health. KFDV NS3 helicase (NS3hel) is considered a potential drug target due to its involvement in the viral replication complex. Here, we resolved the crystal structures of KFDV NS3hel apo and its complex with three phosphate molecules, which indicates a conformational switch during ATP hydrolysis. Our data revealed that KFDV NS3hel has a higher binding affinity for dsRNA, and its intrinsic ATPase activity was enhanced by dsRNA while being inhibited by DNA. Through mutagenesis analysis, several residues within motifs I, Ia, III, V, and VI were identified to be crucial for NS3hel ATPase activity. Notably, the M419A mutation drastically reduced NS3hel ATPase activity. We propose that the methionine-aromatic interaction between residues M419 and W294, located on the surface of the RNA-binding channel, could be a target for the design of efficient inhibitor probes. Moreover, epigallocatechin gallate (EGCG), a tea-derived polyphenol, strongly inhibited NS3hel ATPase activity with an IC50 value of 0.8 µM. Our computational docking data show that EGCG binds at the predicted druggable hotspots of NS3hel. Overall, these findings contribute to the development and design of more effective and specific inhibitors.

Alterations in functional connectivity in patients with non-specific chronic low back pain after motor control exercise: a randomized trial.

BACKGROUND: Motor control exercise (MCE) is effective in alleviating non-specific chronic low back pain (NCLBP). Neuro-imaging research is warranted to explore the underlying neural mechanisms of MCE. AIM: We used resting-state functional magnetic resonance imaging (rs-fMRI) to explore the central mechanism underpinning the effects of MCE in patients with NCLBP. DESIGN: A randomized, single-blinded, controlled trial. SETTING: The setting was out-patient and community. POPULATION: Fifty-eight patients with NCLBP. METHODS: Patients were randomized into the MCE or manual therapy (MT) group. All the participants completed pain-related clinical assessments and rs-fMRI scans before and after intervention. We performed exploratory whole-brain analyses in regional homogeneity (ReHo) and resting-state functional connectivity (rsFC) with significant post-pre differences in ReHo before and after intervention, and investigated associations between imaging and pain-related clinical assessments. RESULTS: Compared with the MT group, a greater alleviation in pain intensity and disability was observed in the MCE group after intervention, and was sustained at the 6-month follow-up (P<0.001). Only the MCE group showed increased ReHo values in the right pre-central gyrus and decreased ReHo values in the bilateral posterior cerebellum (voxel level P<0.001, cluster-level FWE corrected P<0.05). Decreased rsFC of the right posterior cerebellum-left superior parietal gyrus and left insula were significantly positively associated with pain-related disability (voxel level P<0.001, cluster-level FWE corrected P<0.05). CONCLUSIONS: These findings demonstrated that MCE had superior effects in relieving pain and pain-related disability, which might be associated with its modulation of rsFC between the cerebellum and areas involved in sensory-discriminative processing of noxious and somato-sensory stimuli, affection, and cognition. CLINICAL REHABILITATION IMPACT: This study provided preliminary evidence that MCE might alleviate NCLBP through its modulation of the function of brain areas related to chronic pain and postural control. Those results support MCE's clinical application and help physiotherapists to provide better multidisciplinary interventions with the combination of MCE and other first-line treatments.

Novel manufacturing process of pneumococcal capsular polysaccharides using advanced sterilization methods.

Pneumococcal disease is caused by Streptococcus pneumoniae, including pneumonia, meningitis and sepsis. Capsular polysaccharides (CPSs) have been shown as effective antigens to stimulate protective immunity against pneumococcal disease. A major step in the production of pneumococcal vaccines is to prepare CPSs that meet strict quality standards in immunogenicity and safety. The major impurities come from bacterial proteins, nucleic acids and cell wall polysaccharides. Traditionally, the impurity level of refined CPSs is reduced by optimization of purification process. In this study, we investigated new aeration strategy and advanced sterilization methods by formaldehyde or ß-propiolactone (BPL) to increase the amount of soluble polysaccharide in fermentation supernatant and to prevent bacterial lysis during inactivation. Furthermore, we developed a simplified process for the CPS purification, which involves ultrafiltration and diafiltration, followed by acid and alcohol precipitation, and finally diafiltration and lyophilization to obtain pure polysaccharide. The CPSs prepared from formaldehyde and BPL sterilization contained significantly lower level of residual impurities compared to the refined CPSs obtained from traditional deoxycholate sterilization. Finally, we showed that this novel approach of CPS preparation can be scaled up for polysaccharide vaccine production.

Motor Control Exercise Modulates the Neural Plasticity of the Default Mode Network in Patients with Chronic Low Back Pain.

BACKGROUND: Motor control exercise (MCE) effectively alleviates nonspecific chronic low back pain (CLBP), but the neural mechanisms underlying this phenomenon are poorly understood. OBJECTIVE: To study MCE's neural mechanisms in patients with CLBP by resting-state functional magnetic resonance imaging (rs-fMRI). STUDY DESIGN: A prospective, single-blind, randomized, controlled trial. SETTING: Department of Rehabilitation Medicine, The First Affiliated Hospital, Sun Yat-sen University. METHODS: 58 patients were randomly assigned to either the MCE or the Manual Therapy (MT) group. Before and after treatment, all the patients underwent ultrasound imaging to measure transversus abdominis (TrA) activation, rs-fMRI scans and questionnaire assessments. We analyzed the activation and connectivity of the bilateral precuneus based on the fractional amplitude of low-frequency fluctuation (fALFF) and effective connectivity (EC) analyses. Further, we determined the association between imaging and clinical measures. RESULTS: Pain intensity, pain catastrophizing, and pain-related disability were alleviated significantly in both groups post-treatment. However, the MCE group showed a greater reduction in pain-related disability and a better improvement in activation of the right TrA than the MT group. After MCE, patients showed an increase in regional fALFF values in the key node of the default mode network (bilateral precuneus) and decreased EC from the bilateral precuneus to the key node of the frontoparietal network (the left dorsolateral prefrontal cortex (DLPFC)). The pre-to-post-treatment change in the EC from bilateral precuneus into the left DLPFC was significantly correlated with the pre-to-post-treatment change in visual analog scale scores and activation of the right TrA in the MCE group (r = 0.765, P < 0.001 and r = 0.481 and P = 0.043 respectively). LIMITATIONS: The present study showes the correlation between the alteration of brain functions and CLBP-related symptoms, which does not reveal the causal effect between them. Further, this study does not estimate the long-term efficacy of MCE on brain function, and the sample size was not calculated based on fMRI data. CONCLUSION: These findings demonstrate that MCE may alleviate CLBP symptoms in patients by modifying information transmission from the default mode network to the left frontoparietal network.

Perovskite single-crystal thin films: preparation, surface engineering, and application.

Perovskite single-crystal thin films (SCTFs) have emerged as a significant research hotspot in the field of optoelectronic devices owing to their low defect state density, long carrier diffusion length, and high environmental stability. However, the large-area and high-throughput preparation of perovskite SCTFs is limited by significant challenges in terms of reducing surface defects and manufacturing high-performance devices. This review focuses on the advances in the development of perovskite SCTFs with a large area, controlled thickness, and high quality. First, we provide an in-depth analysis of the mechanism and key factors that affect the nucleation and crystallization process and then classify the methods of preparing perovskite SCTFs. Second, the research progress on surface engineering for perovskite SCTFs is introduced. Third, we summarize the applications of perovskite SCTFs in photovoltaics, photodetectors, light-emitting devices, artificial synapse and field-effect transistor. Finally, the development opportunities and challenges in commercializing perovskite SCTFs are discussed.

How climate change affects electricity consumption in Chinese cities-a differential perspective based on municipal monthly panel data.

Addressing the impacts of climate change has become a global public crisis and challenge. China is characterized by a complex and diverse topography and vast territory, which makes it worthwhile to explore the differential impacts of climate change on urban electricity consumption in different zones and economic development conditions. This study examines the differential impact of climate factors on urban electricity consumption in China based on monthly panel data for 282 prefectures from 2011 to 2019 and projects the potential demand for future urban electricity consumption under different climate change scenarios. The results show that (1) temperature changes significantly alter urban electricity consumption, with cooling degree days (CDD) and heating degree days (HDD) contributing positively to urban electricity consumption in areas with different regional and economic development statuses, with elasticity coefficients of 0.1015-0.1525 and 0.0029-0.0077, respectively. (2) The temperature-electricity relationship curve shows an irregular U-shape. Each additional day of extreme weather above 30 °C and below -12 °C increases urban electricity consumption by 0.52% and 1.52% in the north and by 2.67% and 1.32% in the south. Poor cities are significantly more sensitive to extremely low temperatures than rich cities. (3) Suppose the impacts of climate degradation on urban electricity consumption are not halted. In that case, the possible Shared Socioeconomic Pathways 1-1.9 (SSP1-1.9), SSP1-2.6, and SSP2-4.5 will increase China's urban electricity consumption by 1621.96 billion kWh, 2960.87 billion kWh, and 6145.65 billion kWh, respectively, by 2090. Finally, this study makes some policy recommendations and expectations for follow-up studies.

PHLDA1 knockdown alleviates mitochondrial dysfunction and endoplasmic reticulum stress-induced neuronal apoptosis via activating PPARγ in cerebral ischemia-reperfusion injury.

Mitochondrial dysfunction and endoplasmic reticulum (ER) stress occur in ischemic stroke. The disruption of these two organelles can directly lead to cell death through various signaling pathways. Thus, investigation of the associated molecular mechanisms in cerebral ischemia is a prerequisite for stroke treatment. Pleckstrin homology-like domain family A member 1 (PHLDA1) is a multifunctional protein that can modulate mitochondrial function and ER stress in cardiomyocyte and cancer cells. This work studied the role of PHLDA1 in cerebral ischemic/reperfusion (I/R) injury and explored the underlying mechanisms associated with mitochondrial functions and ER stress. Middle cerebral artery occlusion/reperfusion (MCAO/R)-treated mice and oxygen-glucose deprivation/reoxygenation (OGD/R)-stimulated neurons were used as I/R models in vivo and in vitro, respectively. PHLDA1 was upregulated in ischemic penumbra of MCAO/R-induced mice and OGD/R-exposed neurons. In vitro, PHLDA1 knockdown protected neurons from OGD/R-induced apoptosis. In vivo, PHLDA1 silencing facilitated functional recovery and reduced cerebral infarct volume. Mechanistically, PHLDA1 knockdown promoted PPARγ nuclear translocation, which may mediate the effects on reversion of mitochondrial functions and alleviation of ER stress. In summary, PHLDA1 knockdown alleviates neuronal ischemic injuries in mice. PPARγ activation and mitochondrial dysfunction and endoplasmic reticulum stress attenuation are involved in the underlying mechanisms.

Structural mechanism of dsDNA recognition by the hMNDA HIN domain: New insights into the DNA-binding model of a PYHIN protein.

The hematopoietic interferon-inducible nuclear (HIN) domain of the PYHIN family of proteins recognizes double-stranded DNA (dsDNA) through different dsDNA-binding modes. These modes apparently confer different roles upon these proteins in the regulation of innate immune responses, gene transcription, and apoptosis. Myeloid cell nuclear differentiation antigen (MNDA), a member of the human PYHIN family, binds DNA and regulates gene transcription in monocytes. However, the mechanism of DNA recognition and DNA-binding modes of human MNDA (hMNDA) remain unclear. Here, we determined the crystal structure of the hMNDA-HIN domain in complex with dsDNA at 2.4 Å resolution, and reveal that hMNDA-HIN binds to dsDNA in a sequence-independent manner. Structure and mutation studies indicated that hMNDA-HIN binds to dsDNA through a unique mode, involving two dsDNA-binding interfaces. Interface I exhibits an AIM2-like dsDNA-binding mode, and interface II has a previously unreported mode of dsDNA-binding. These results provide new insights into the DNA-binding modes of this PYHIN protein.

Precise modulation strategies of 2D/3D perovskite heterojunctions in efficient and stable solar cells.

2D/3D perovskite heterojunctions exhibit promising prospects in the improvement of efficiency and stability of perovskite solar cells (PSCs). However, many challenges remain in the development of high-quality 2D/3D heterojunctions, such as a reliable pathway to control the perovskite phase and generally poor performance in inverted (p-i-n) devices, which limit their commercialization. Fortunately, many excellent works have proposed lots of strategies to solve these challenges, which have triggered a new wave of research on 2D/3D perovskite heterojunctions in recent years. In this paper, the latest research progress and the critical factors involved in the modulating mechanisms of PSCs with 2D/3D heterojunctions have been summarized and laid out systematically. The advantages of constructing 2D/3D perovskite heterojunctions in PSCs are highlighted, and the problems and related solutions of low-dimensional perovskites as passivation layers towards high-performance PSCs are also discussed in depth. Finally, the prospects of 2D/3D perovskite heterojunctions utilized in the passivation strategies to further improve the photovoltaic performance of PSCs in the future have been presented.

Application of Natural Molecules in Efficient and Stable Perovskite Solar Cells.

Perovskite solar cells (PSCs), one of the most promising photovoltaic technologies, have been widely studied due to their high power conversion efficiency (PCE), low cost, and solution processability. The architecture of PSCs determines that high PCE and stability are highly dependent on each layer and the related interface, where nonradiative recombination occurs. Conventional synthetic chemical materials as modifiers have disadvantages of being toxic and costly. Natural molecules with advantages of low cost, biocompatibility, and being eco-friendly, and have improved PCE and stability by modifying both functional layers and interface. In this review, we discuss the roles of natural molecules on PSCs devices in terms of the perovskite active layer, interface, carrier transport layers (CTLs), and substrate. Finally, the summary and outlook for the future development of natural molecule-modified PSCs are also addressed.

1-Adamantanamine Hydrochloride Resists Environmental Corrosion to Obtain Highly Efficient and Stable Perovskite Solar Cells.

Passivating the defective surface of perovskite film is a promising strategy to improve the stability and efficiency of perovskite solar cells (PSCs). Herein, 1-adamantanamine hydrochloride (ATH) is introduced to the upper surface of the perovskite film to heal the defects of the perovskite surface. The best-performance ATH-modified device has a higher efficiency (23.45%) than the champion control device (21.53%). The defects are passivated, interfacial nonradiative recombination is suppressed, and interface stress is released by the ATH deposited on the perovskite film, leading to longer carrier lifetimes and enhancement in open-circuit voltage (VOC) and fill factor (FF) of the PSCs. With obvious improvement, VOC and FF of 1.159 V and 0.796 for the control device are raised to 1.178 V and 0.826 for the ATH-modified device, respectively. Finally, during an operational stability measurement of more than 1000 h, the ATH-treated PSC exhibited better moisture resistance, thermal persistence, and light stability.

Structure and mutation analysis of the hexameric P4 from Pseudomonas aeruginosa phage phiYY.

phiYY is a foremost member of Cystoviridae isolated from Pseudomonas aeruginosa. Its P4 protein with NTPase activity is a molecular motor for their genome packing during viral particle assembly. Previously studies on the P4 from four Pseudomonas phages phi6, phi8, phi12 and phi13 reveal that despite of belonging to the same protein family, they are unique in sequence, structure and biochemical properties. To better understand the structure and function of phiYY P4, four crystal structures of phiYY P4 in apo-form or combined with different ligands were solved at the resolution between 1.85 Å and 2.43 Å, which showed drastic conformation change of the H1 motif in ligand-bound forms compared with in apo-form, a four residue-mutation at the ligand binding pocket abolished its ATPase activity. Furthermore, the truncation mutation of the 50 residues at the C-terminal did not impair the hexamerization and ATP hydrolysis.