Propylamine hydrobromide passivated tin-based perovskites to efficient solar cells

The development of tin-based devices with low toxicity is critical for the commercial viability of perovskite solar cells.However because tin halide is a stronger Lewis acid,its crystallization rate is extremely fast,resulting in the formation of numerous defects that affect the device performance of tin-based perovskite solar cells.Herein,propylamine hydrobromide(PABr)was added to the perovskite precursor solution as an additive to passivate defects and fabricate more uniform and dense perovskite films.Because propylamine cations are too large to enter the perovskite lattices,they only exist at the grain boundary to passivate surface defects and promote crystal growth in a preferred orientation.The PABr additive raises the average short-circuit current density from 19.45 to 25.47 mA·cm^(-2)by reducing carrier recombination induced by defects.Furthermore,the device’s long-term illumination stability is improved after optimization,and the hysteresis effect is negligible.The addition of PABr results in a power conversion efficiency of 9.35%.

Enhanced fluorescence sensing of tetracycline with Ti_(2)C quantum dots

Ti_(2)C quantum dots(QDs)with rich surface functional groups have been synthesized using a hydrothermal method,and used to detect tetracycline(Tc)based on enhanced fluorescence.The interaction between the surface functional groups of Ti_(2)C QDs and Tc enhanced the fluorescence of Tc at 514 nm,which is used to detect Tc quickly and accurately.Under optimal conditions,the fluorescence intensity was linear to the concentration of Tc in the range of 50.0–30.0μM,with a detection limit of 21.6 nM.Furthermore,the Tc-Ti_(2)C QDs detection system was evaluated for detection of Tc in milk and artificial urine.This study demonstrates a new and simple strategy for Tc detection,which is important for food safety and human health.

Essential tremor-Parkinson's disease syndrome: clinical characteristics and subtypes using cluster analysis

Background: Essential tremor (ET) and Parkinson’s disease (PD) are common movement disorders. ET-PD syndrome is characterized by the occurrence of PD in patients with a previous history of ET, which may be an independent phenotype distinct from PD. This study aims to identify clinical characteristics and subtypes in ET-PD. Methods: A total of 93 newly diagnosed ET-PD patients and 93 newly diagnosed PD patients matched for age, sex, education, and disease duration of PD were selected using propensity score matching analysis. The K-means cluster analysis was performed for 11 variables derived from the ET-PD group, and cluster profiles were established through statistical analysis of demographic and clinical variables. Results: The ET-PD group consisted of a high number of patients with a family history of ET exhibiting evident tremor with milder hypokinesia and postural instability symptoms, as compared to the PD group. Through the cluster analysis, two clusters of ET-PD patients were identified. The ET-PD cluster 1 ( n = 34) had a shorter ET duration before PD onset, lower number of patients with a family history of ET, higher unified PD rating scale instability scores, higher non-motor symptoms scores (non-motor symptoms scale D1 scores, Hamilton depression scale scores, Hamilton anxiety scale scores, and PD sleep scale-2 scores), and higher Chinese version of the PD questionnaire-39 scores relative to the ET-PD cluster 2 ( n = 59). Conclusion: ET-PD patients had significantly different characteristics for motor symptoms as compared to PD patients, and may be distinctly divided into two clinical subtypes, namely, the ET-PD complex type and the ET-PD simple type.

Rare variant analysis of PLXNA1 in Parkinson’s disease in the Chinese population

Recently,p.Glu1121Ter in PLXNA1 was identified as po-tential cause for a patient with parkinsonism.However,no further replication has been conducted in a wider range of Parkinson’s disease(PD)cohorts.To evaluate the genetic association of PLXNA1 with PD,we systematically analyzed the rare protein-coding variants in 1,245 Chinese patients with whole exome sequencing.

Unique characteristics of the genetics epidemiology of amyotrophic lateral sclerosis in China

Continual discoveries of new genes and unraveling the genetic etiology in amyotrophic lateral sclerosis(ALS) have provided greater insight into the underlying pathogenesis in motor neuron degeneration, as well as facilitating the disease modeling and the testing of targeted therapeutics. While, the genetic etiology accounted for two-thirds of FALS and approximately 11% of SALS in Caucasians. However, the contributions of these causative genes to ALS vary among different populations. Furthermore, the prominent difference between Chinese population and other ethnics remains a source of ongoing debate. We systemically reviewed genetics literature of Chinese ALS populations and updated the mutation frequencies of the main ALS-implicated genes aiming to determine the genetic features of ALS in Chinese population. We also reviewed the associations between ALSimplicated single nucleotide polymorphisms(SNPs) and the risk of ALS in Chinese population. A total of 116 studies were included in this analysis(86 gene mutation study articles and 30 SNPs study articles). The results showed that the overall gene mutation rates of ALS-related causative genes were 55.0% in familial ALS(FALS) and 11.7% in sporadic ALS(SALS) in Chinese population. In Chinese FALS, the highest mutation frequency was found in SOD1 gene(25.6%), followed by FUS(5.8%), TARDBP(5.8%), DCTN1(3.6%) and C9 orf 72(3.5%). In Chinese SALS, the highest mutation frequency was also identified in SOD1 gene(1.6%), followed by ANXA11(1.4%), FUS(1.3%), SQSTM1(1.0%), OPTN(0.9%) and CCNF(0.8%).The associations between several SNPs and risk of ALS were also reported in Chinese population. The genetic features of ALS in Chinese population are significantly different from those in Caucasian population, indicating an association between genetic susceptibility and origin of population. Further explorations are required to understand the gene complexity of ALS, including the contribution of most minor genes and the molecular mechanisms in ALS pathologies.

The ultraviolet and blue luminescence properties of ZnO:Zn thin film

The ultraviolet (UV) and blue luminescence of Zn-rich zinc oxide thin film deposited by electron-beam evaporation have been investigated at room temperature (RT). We observed that the UV and blue electroluminescence (EL) emission band centered around 480 nm which is blue shifted in comparison with that of the ZnO thin film prepared by low pressure metal organic chemical vapor deposition (LP MOCVD). The UV emission is much stronger than blue emission in the photoluminescence (PL) spectra. The field-induced ionization of excited luminescent centers of ZnO:Zn thin film at high electric field and the difference between PL and EL are discussed. The experiments show that the ZnO:Zn thin film provides a hopeful new mechanism to obtain UV and blue emission.

Disruption of the white matter structural network and its correlation with baseline progression rate in patients with sporadic amyotrophic lateral sclerosis

Objective:There is increasing evidence that amyotrophic lateral sclerosis(ALS)is a progressive neurodegenerative disease impacting large-scale brain networks.However,it is still unclear which structural networks are associated with the disease and whether the network connectomics are associated with disease progression.This study was aimed to characterize the network abnormalities in ALS and to identify the network-based biomarkers that predict the ALS baseline progression rate.Methods:Magnetic resonance imaging was performed on 73 patients with sporadic ALS and 100 healthy participants to acquire difusion-weighted magnetic resonance images and construct white matter(WM)networks using tractography methods.The global and regional network properties were compared between ALS and healthy subjects.The single-subject WM network matrices of patients were used to predict the ALS baseline progression rate using machine learning algorithms.Results:Compared with the healthy participants,the patients with ALS showed signifcantly decreased clustering coefcient C_(p)(P=0.0034,t=2.98),normalized clustering coefcientγ(P=0.039,t=2.08),and small‐worldnessσ(P=0.038,t=2.10)at the global network level.The patients also showed decreased regional centralities in motor and non-motor systems including the frontal,temporal and subcortical regions.Using the single-subject structural connection matrix,our classifcation model could distinguish patients with fast versus slow progression rate with an average accuracy of 85%.Conclusion:Disruption of the WM structural networks in ALS is indicated by weaker small-worldness and disturbances in regions outside of the motor systems,extending the classical pathophysiological understanding of ALS as a motor disorder.The individual WM structural network matrices of ALS patients are potential neuroimaging biomarkers for the baseline disease progression in clinical practice.

Influence of the electric field on carriers recombination zone in bilayer organic electroluminescent device

The electroluminescence (EL) of bilayer devices (ITO/Polymer/Alqa/AI) made from two PPV derivatives (MN-PPV and MEH-PPV), respectively, and the influence of the organic layers’ thickness on the characteristics of the device are investigated. Different spectra and variations are observed for different thicknesses of Alq3 layer in this bilayer organic light-emitting diodes (LEDs) as increasing applied bias. Based on the energy level and field-assisted tunneling at the interface, we attributed these phenomena to electric field redistribution in the device and field-assisted charges being transported and tunneling through energy barrier at high electric field.