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Regulations currently in force enable to claim that the lead content in perovskite solar cells is low enough to be safe, or no more dangerous, than other electronics also containing lead. However, the actual environmental impact of lead from perovskite is unknown. Here we show that the lead from perovskite leaking into the ground can enter plants, and consequently the food cycle, ten times more effectively than other lead contaminants already present as the result of the human activities. We further demonstrate that replacing lead with tin represents an environmentally-safer option. Our data suggest that we need to treat the lead from perovskite with exceptional care. In particular, we point out that the safety level for lead content in perovskite-based needs to be lower than other lead-containing electronics. We encourage replacing lead completely with more inert metals to deliver safe perovskite technologies. Halide perovskites are promising for next generation photovoltaic technology but their environmental impact has not been fully evaluated. Here Li et al. show that the lead from perovskites is ten times more dangerous than lead-containing electronics while tin perovskites are much less bioavailable.

Background Population ageing is an increasingly severe global issue. And this has been posing challenges for public health policies and medical resource allocation There are various features of population ageing in different regions worldwide. Methods All data were obtained from the health data of World Bank Open Data. Quantile linear regression was used to subtly measure the common variation tendency and strength of the global ageing rate and ageing population. The Bayesian space-time hierarchy model (BSTHM) was employed to assess the detailed spatial temporal evolution of ageing rate and ageing population in global 195 countries and regions. Results Annual growth of the ageing (65 and above) rate occurred on six continents: Europe (0.1532%), Oceania (0.0873%), Asia (0.0834%), South America (0.0723%), North America (0.0673%) and Africa (0.0069%). The coefficient of variation of the global ageing rate increased from 0.54 in 1960 to 0.69 in 2017. The global ageing rate and ageing population increased over this period, correlating positively with their quantiles. Most countries (37/39) in Europe belong to the top level with regard to the ageing rate, including the countries with the greatest degree of ageing—Sweden, Germany, Austria, Belgium and the UK—whose spatial relative risks of ageing are 3.180 (3.113–3.214), 3.071 (3.018–3.122), 2.951 (2.903–3.001), 2.932 (2.880–2.984) and 2.917 (2.869–2.967), respectively. Worldwide, 44 low ageing areas which were distributed mainly in Africa (26 areas) and Asia (15 areas) experienced a decreasing trend of ageing rates. The local trends of ageing population in the 195 areas increased. Conclusions The differentiation of global population ageing is becoming increasingly serious. Globally, all 195 areas showed an increasing local ageing trend in absolute terms, although there were 44 low-ageing areas that experienced a decreasing local trend of ageing rate. The statistical results may provide some baseline reference for developing public health policies in various countries or regions, especially in less-developed areas.

HighlightsA novel physical approach is proposed to enhance the electrocatalytic performance by electric field.Under the action of electric field, some stable conductive filaments consisting of oxygen vacancies are formed in the Ni/Co3O4 film, which remarkably reduces the system resistivity.The electric-field-treated Ni/Co3O4 material exhibits significantly superior activity and stability as a bifunctional electrocatalyst for overall water splitting, and its performance exceeds the state-of-the-art electrocatalysts.Rational design of bifunctional electrocatalysts for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) with excellent activity and stability is of great significance, since overall water splitting is a promising technology for sustainable conversion of clean energy. However, most electrocatalysts do not simultaneously possess optimal HER/OER activities and their electrical conductivities are intrinsically low, which limit the development of overall water splitting. In this paper, a strategy of electric field treatment is proposed and applied to Ni/Co3O4 film to develop a novel bifunctional electrocatalyst. After treated by electric field, the conductive channels consisting of oxygen vacancies are formed in the Co3O4 film, which remarkably reduces the resistance of the system by almost 2 × 104 times. Meanwhile, the surface Ni metal electrode is partially oxidized to nickel oxide, which enhances the catalytic activity. The electric-field-treated Ni/Co3O4 material exhibits super outstanding performance of HER, OER, and overall water splitting, and the catalytic activity is significantly superior to the state-of-the-art noble metal catalysts (Pt/C, RuO2, and RuO2 ǁ Pt/C couple). This work provides an effective and feasible method for the development of novel and efficient bifunctional electrocatalyst, which is also promising for wide use in the field of catalysis.

The tuberculous granuloma is an elaborately organized structure and one of the main histological hallmarks of tuberculosis. Macrophages, which are important immunologic effector and antigen-presenting cells, are the main cell type found in the tuberculous granuloma and have high plasticity. Macrophage polarization during bacterial infection has been elucidated in numerous recent studies; however, macrophage polarization during tuberculous granuloma formation and development has rarely been reported. It remains to be clarified whether differences in the activation status of macrophages affect granuloma formation. In this study, the variation in macrophage polarization during the formation and development of tuberculous granulomas was investigated in both sections of lung tissues from tuberculosis patients and an in vitro tuberculous granuloma model. The roles of macrophage polarization in this process were also investigated. Mycobacterium tuberculosis (M. tuberculosis) infection was found to induce monocyte-derived macrophage polarization. In the in vitro tuberculous granuloma model, macrophage transformation from M1 to M2 was observed over time following M. tuberculosis infection. M2 macrophages were found to predominate in both necrotic and non-necrotic granulomas from tuberculosis patients, while both M1 and M2 polarized macrophages were found in the non-granulomatous lung tissues. Furthermore, it was found that M1 macrophages promote granuloma formation and macrophage bactericidal activity in vitro, while M2 macrophages inhibit these effects. The findings of this study provide insights into the mechanism by which M. tuberculosis circumvents the host immune system as well as a theoretical foundation for the development of novel tuberculosis therapies based on reprogramming macrophage polarization.

Background Globally, the increasingly severe population ageing issue has been creating challenges in terms of medical resource allocation and public health policies. The aim of this study is to address the space-time trends of the population-ageing rate (PAR), the number of medical resources per thousand residents (NMRTR) in mainland China in the past 10 years, and to investigate the spatial and temporal matching between the PAR and NMRTR in mainland China. Methods The Bayesian space-time hierarchy model was employed to investigate the spatiotemporal variation of PAR and NMRTR in mainland China over the past 10 years. Subsequently, a Bayesian Geo-Detector model was developed to evaluate the spatial and temporal matching levels between PAR and NMRTR at national level. The matching odds ratio (OR) index proposed in this paper was applied to measure the matching levels between the two terms in each provincial area. Results The Chinese spatial and temporal matching q-statistic values between the PAR and three vital types of NMRTR were all less than 0.45. Only the spatial matching Bayesian q-statistic values between the PAR and the number of beds in hospital reached 0.42 (95% credible interval: 0.37, 0.48) nationwide. Chongqing and Guizhou located in southwest China had the highest spatial and temporal matching ORs, respectively, between the PAR and the three types of NMRTR. The spatial pattern of the spatial and temporal matching ORs between the PAR and NMRTR in mainland China exhibited distinct geographical features, but the geographical structure of the spatial matching differed from that of the temporal matching between the PAR and NMRTR. Conclusion The spatial and temporal matching degrees between the PAR and NMRTR in mainland China were generally very low. The provincial regions with high PAR largely experienced relatively low spatial matching levels between the PAR and NMRTR, and vice versa. The geographical pattern of the temporal matching between the PAR and NMRTR exhibited the feature of north-south differentiation.

The breeding of crops with improved nitrogen use efficiency (NUE) is crucial for sustainable agriculture, but the involvement of epigenetic modifications remains unexplored. Here, we analyze the chromatin landscapes of two wheat cultivars (KN9204 and J411) that differ in NUE under varied nitrogen conditions. The expression of nitrogen metabolism genes is closely linked to variation in histone modification instead of differences in DNA sequence. Epigenetic modifications exhibit clear cultivar-specificity, which likely contributes to distinct agronomic traits. Additionally, low nitrogen (LN) induces H3K27ac and H3K27me3 to significantly enhance root growth in KN9204, while remarkably inducing NRT2 in J411. Evidence from histone deacetylase inhibitor treatment and transgenic plants with loss function of H3K27me3 methyltransferase shows that changes in epigenetic modifications could alter the strategy preference for root development or nitrogen uptake in response to LN. Here, we show the importance of epigenetic regulation in mediating cultivar-specific adaptation to LN in wheat. The analysis of wheat cultivars reveals that variations in histone modification, rather than DNA sequence, are closely linked to the expression of nitrogen metabolism genes and distinct agronomic traits. The findings suggest that epigenetic regulation plays a crucial role in cultivar-specific adaptation to low nitrogen conditions in wheat.

Background Neutropenia is more common in patients with systemic lupus erythematosus (SLE) and is a major cause of life-threatening infections. The increased apoptosis of neutrophils is likely to be an essential cause of neutropenia in SLE. However, the detailed mechanisms of increased neutrophil apoptosis in SLE remain unknown. This study focused on the role of Krüppel-like factor 2 (KLF2) in the regulation of neutrophil apoptosis and its association with SLE disease activity. Methods The levels of KLF2 in neutrophils from SLE patients and healthy controls (HCs) were detected by RT-PCR and western blot. The relationship between the levels of KLF2 and the apoptosis levels of neutrophils in SLE patients was analyzed. The KLF2 inhibitor Geranylgeranyl pyrophosphate (GGPP) and the KLF2 inducer geranylgeranyl transferase inhibitor (GGTI-298) were used to incubate with neutrophils to investigate the role of KLF2 in the regulation of neutrophil apoptosis. To clarify whether serum from SLE patients affects neutrophil KLF2 expression and apoptosis, sera from SLE patients were collected and used to incubate with neutrophils from HCs, followed by the detection of KLF2 levels and apoptosis levels of neutrophils. Additionally, the correlation between KLF2 levels and SLE disease activity index (SLEDAI) was analyzed. Results The expression of KLF2 in neutrophils of SLE patients was significantly suppressed, and the decreased KLF2 was associated with the upregulation of neutrophil apoptosis. Moreover, newly diagnosed SLE patients, SLE patients with higher serum IgG and positive anti-Smith antibodies had lower KLF2 expression. Furthermore, we demonstrated that modulating the expression of KLF2 can regulate the apoptosis of neutrophils. The levels of KLF2 in neutrophils were associated with the SLEDAI. In addition, we found that serum from SLE patients could induce apoptosis in neutrophils by down-regulating the expression of KLF2. Conclusions KLF2 controls the apoptosis of neutrophils and is associated with SLEDAI, which suggests that KLF2 in neutrophils may be involved in the occurrence and development of SLE.

Background NAT10 is the firstly recognized RNA acetyltransferase that participates in multiple cellular biological processes and human disease. However, the role of N-acetyltransferase 10 (NAT10) in ankylosing spondylitis (AS) is still poorly elaborated. Methods Fifty-six patients with New-Onset AS, 52 healthy controls (HC), 20 patients with rheumatoid arthritis (RA) and 16 patients with systemic lupus erythematosus (SLE) were recruited from The First Afliated Hospital of Nanchang University, and their clinical characteristics were recorded. The expression level of NAT10 in peripheral blood mononuclear cell (PBMC) was examined using reverse transcription-quantitative PCR analysis. The correlations between the expression level of NAT10 in the New-Onset AS patients and disease activity of AS were examined, and receiver operating characteristic (ROC) curves were built to evaluate predictive value in AS. Univariate analysis and multivariate regression analysis were used to analyze the risk factors and construct predictive model. Results The mRNA expressions of NAT10 in PBMC from new-onset AS patients were significantly low and there were negative correlation between mRNA NAT10 and ASDAS-CRP, BASDIA in new-onset AS patients. ROC analysis suggested that mRNA NAT10 has value in distinguishing new-onset AS patients from HC, RA and SLE. Furthermore, a novel predictive model based on mRNA NAT10 and neutrophil percentages (N%) was constructed for distinguishing new-onset AS patients from HC (AUC = 0.880, sensitivity = 84.62%, specificity = 76.92%) and the predictive model correlated with the activity of new-onset AS. Furthermore, the predictive model could distinguish new-onset AS patients from RA and SLE (AUC = 0.661, sensitivity = 90.38%, specificity = 47.22%). Moreover, the potential predictive value of the combination of predictive model-HLA-B27 for AS vs. HC with a sensitivity of 92.86% (39/42), a specificity of 100.00% (52/52) and an accuracy of 96.81% (91/94) was superior to that of HLA-B27, which in turn had a sensitivity of 84.44% (38/45), a specificity of 100.00% (52/52) and an accuracy of 92.78% (90/97). Conclusion The present study suggested that the decreased mRNA NAT10 may play a role in AS pathogenesis and predictive model based on mRNA NAT10 and N% act as bioindicator for forecast and progression of diseases.

The power conversion efficiency of modern perovskite solar cells has surpassed that of commercial photovoltaic technology, showing great potential for commercial applications. However, the current high-performance perovskite solar cells all contain toxic lead elements, blocking their progress toward industrialization. Lead-free tin-based perovskite solar cells have attracted tremendous research interest, and more than 14% power conversion efficiency has been achieved. In tin-based perovskite, Sn2+ is easily oxidized to Sn4+ in air. During this process, two additional electrons are introduced to form a heavy p-type doping perovskite layer, necessitating the production of hole transport materials different from that of lead-based perovskite devices or organic solar cells. In this review, for the first time, we summarize the hole transport materials used in the development of tin-based perovskite solar cells, describe the impact of different hole transport materials on the performance of tin-based perovskite solar cell devices, and summarize the recent progress of hole transport materials. Lastly, the development direction of lead-free tin-based perovskite devices in terms of hole transport materials is discussed based on their current development status. This comprehensive review contributes to the development of efficient, stable, and environmentally friendly tin-based perovskite devices and provides guidance for the hole transport layer material design.

Two polysaccharides were obtained from steamed ginseng via ultrafiltration, and their physical–chemical properties, solution properties and antifatigue activities were studied. WSGP-S3 and WSGP-G3 were acid heteropolysaccharides with the molecular weights of 2.03 × 10 4 and 4.86 × 10 4 , respectively. They were composed of different molar ratios of the monosaccharides Rha, GlcA, GalA, Glc, Gal, and Ara. The results of size-exclusion chromatography–multiangle laser light scattering analysis, Conge red staining and Circular dichroism spectroscopy revealed that WSGP-S3 exhibited a random conformation of branched clusters in solution. By contrast, WSGP-G3 exhibited an ordered conformation, including helix-like conformations in aqueous solution. Antifatigue activity tests proved that WSGP-S3 markedly prolonged the exhaustive swimming time of fatigued mice; increased liver and muscle glycogen levels and superoxide dismutase, catalase, glutathione peroxidase activities and decreased blood lactic acid, nitrogen and malondialdehyde levels compared with the control treatment. Moreover, it enhanced spleen cell proliferation in fatigued mice. By contrast, WSGP-G3 had no significant effect on fatigued mice. The results showed that WSGP-S3 might have a major contribution to the antifatigue effects of steamed ginseng polysaccharides and could be a potential anti-fatigue polysaccharide.