Toward durable all-inorganic perovskite solar cells: from lead-based to lead-free.

Organic-inorganic metal halide perovskite solar cells (PSCs) have attracted extensive attention from the photovoltaic (PV) community due to their fast-growing power conversion efficiency from 3.8% to 26.7% in only 15 years. However, these organic-inorganic hybrid PSCs suffer from inferior long-term operational stability under thermal and light stress, due to the fragile hydrogen bonds between organic cations and inorganic slabs. This motivates the exploration of more robust all-inorganic alternatives against external stimuli, by substituting inorganic cesium (Cs) cations for volatile organic cations. Despite reinforced ionic interaction between Cs cations and metal halide frameworks, these Cs-based all-inorganic perovskites tend to undergo spontaneous phase transition from photoactive black phases to non-perovskite yellow phases at room temperature, significantly deteriorating their optoelectronic performance. Thus, tremendous efforts have been made to stabilize the black phase of CsPbI3, while the phase instability issue of the tin-based analogue of CsSnI3 has not been resolved yet. This highlight article summarizes the empirical advances in stabilizing the metastable phases of CsPbI3, aiming to provide useful guidelines to accelerate the development of phase-stable CsSnI3 for durable lead-free PV applications. Finally, the remaining challenges and future research opportunities are outlined, providing a road map to realize efficient and durable all-inorganic perovskite solar cells towards practical applications.

Plastic debris mediates bacterial community coalescence by breaking dispersal limitation in the sediments of a large river.

Plastic debris has recently been proposed as a novel habitat for bacterial colonization, which can raise perturbations in bacterial ecology after burial in riverine sediments. However, community coalescence, as a prevalent process involving the interrelationships of multiple communities and their surrounding environments, has been rarely discussed to reveal the impact of the plastisphere on sedimentary bacterial community. This study analyzed the bacterial community in plastic debris and sediment along the Nujiang River, elucidating the role of the plastisphere in mediating community coalescence in sediments. Our results demonstrated that the plastisphere and sedimentary bacterial communities exhibited distinct biogeography along the river (r = 0.694, p < 0.01). Based on overlapped taxa and SourceTracker, the extent of coalescence between adjacent communities was in following orders: plastic-plastic (0.589) > plastic-sediment (0.561) > sediment-sediment (0.496), indicating the plastisphere promoted bacterial community coalescence along the river. Flow velocity and geographic distance were the major factors driving the plastisphere changes, suggesting that the plastisphere were vulnerable to dispersal. The null model and the neutral model provided additional support for the higher immigration ability of the plastisphere to overcome dispersal limitation, highlighting the potential importance of the plastisphere in community coalescence. Network analysis indicated the critical role of keystone species (Proteobacteria, Bacteroidetes, and Gemmatimonadetes) in mediating the coalescence between sedimentary bacterial community and the plastisphere. In summary, the plastisphere could mediate the coalescence of bacterial communities by overcoming dispersal limitation, which provides new perspectives on the plastisphere altering bacterial ecology in riverine sediments.

The Associations between Snack Intake and Cariogenic Oral Microorganism Colonization in Young Children of a Low Socioeconomic Status.

Cariogenic microorganisms are crucial pathogens contributing to the development of early childhood caries. Snacks provide fermentable carbohydrates, altering oral pH levels and potentially affecting microorganism colonization. However, the relationship between snack intake and cariogenic microorganisms like Candida and Streptococcus mutans in young children is still unclear. This study aimed to assess this association in a prospective underserved birth cohort. Data from children aged 12 to 24 months, including oral microbial assays and snack intake information, were analyzed. Sweet and non-sweet indices based on the cariogenic potential of 15 snacks/drinks were created. Mixed-effects models were used to assess the associations between sweet and non-sweet indices and S. mutans and Candida carriage. Random forest identified predictive factors of microorganism carriage. Higher non-sweet index scores were linked to increased S. mutans carriage in plaques (OR = 1.67, p = 0.01), potentially strengthening with age. Higher sweet index scores at 12 months were associated with increased Candida carriage, reversing at 24 months. Both indices were top predictors of S. mutans and Candida carriage. These findings underscore the associations between snack intake and cariogenic microorganism carriage and highlight the importance of dietary factors in oral health management for underserved young children with limited access to dental care and healthy foods.

DFT-assisted low-dimensional carbon-based electrocatalysts design and mechanism study: a review.

Low-dimensional carbon-based (LDC) materials have attracted extensive research attention in electrocatalysis because of their unique advantages such as structural diversity, low cost, and chemical tolerance. They have been widely used in a broad range of electrochemical reactions to relieve environmental pollution and energy crisis. Typical examples include hydrogen evolution reaction (HER), oxygen evolution reaction (OER), oxygen reduction reaction (ORR), carbon dioxide reduction reaction (CO2RR), and nitrogen reduction reaction (NRR). Traditional "trial and error" strategies greatly slowed down the rational design of electrocatalysts for these important applications. Recent studies show that the combination of density functional theory (DFT) calculations and experimental research is capable of accurately predicting the structures of electrocatalysts, thus revealing the catalytic mechanisms. Herein, current well-recognized collaboration methods of theory and practice are reviewed. The commonly used calculation methods and the basic functionals are briefly summarized. Special attention is paid to descriptors that are widely accepted as a bridge linking the structure and activity and the breakthroughs for high-volume accurate prediction of electrocatalysts. Importantly, correlated multiple descriptors are used to systematically describe the complicated interfacial electrocatalytic processes of LDC catalysts. Furthermore, machine learning and high-throughput simulations are crucial in assisting the discovery of new multiple descriptors and reaction mechanisms. This review will guide the further development of LDC electrocatalysts for extended applications from the aspect of DFT computations.

Antimicrobial Furancarboxylic Acids from a Penicillium sp.

Ten novel (1, 2, 3a, 3b, 4a, 4b, 5a, 5b, 6a, and 6b) furancarboxylic acids including four pairs of epimers (3a, 3b; 4a, 4b; 5a, 5b; 6a, 6b), together with seven known analogues (7a, 7b, 8a, 8b, 9a, 9b, and 10), were isolated from the fermentation of the soil-derived fungus Penicillium sp. sb62. Their structures were established on the basis of spectroscopic data analysis, and the absolute configurations were determined by time-dependent density functional theory electronic circular dichroism calculations, comparison of the specific optical rotation values, and modified Mosher's method. Compounds 1-4 represent the first class of natural furancarboxylic acids featuring a thiophene moiety. Compounds 1-7 showed antimicrobial inhibitory activities against Escherichia coli, Staphylococcus aureus, and Candida albicans with MIC values ranging from 0.9 to 7.0 µg/mL, from 1.7 to 3.5 µg/mL, and from 3.3 to 7.0 µg/mL, respectively.

Alkaloids with Immunosuppressive Activity from the Bark of Pausinystalia yohimbe.

Ten new alkaloids (1-10), including two pairs of enantiomeric mixtures (5a,b and 6a,b), and 15 known analogues (11-25) were obtained from the bark of Pausinystalia yohimbe. The structures of 1-25 were established by spectroscopic methods, and the absolute configurations of compounds 1-10 were resolved by X-ray diffraction and ECD data analyses. The in vitro immunosuppressive activities of selected isolates were tested. Compounds 11 and 16 exhibited moderate inhibition with IC50 values of 16.8 and 27.6 µM against ConA-induced T lymphocyte proliferation and 13.5 and 40.5 µM against LPS-induced B lymphocyte proliferation, respectively.

Redox/pH dual-sensitive hybrid micelles for targeting delivery and overcoming multidrug resistance of cancer.

A redox/pH dual-sensitive graft copolymer, poly(ß-amino ester)-g-d-α-tocopherol polyethylene glycol succinate (PBAE-g-TPGS), was synthesized through a Michael-type step polymerization using disulfide linkage-containing TPGS macromonomers. Pluronic F127 (F127) and folate-F127 conjugation were introduced to prepare paclitaxel (PTX)-loaded hybrid micelles to improve their biocompatibility and serum stability and also to achieve targeted delivery. The hybrid micelles exhibited in vitro redox/pH-sensitive PTX release, enhanced cellular uptake through receptor-mediated endocytosis, and strengthened anticancer activities in both the drug-sensitive human breast cancer MCF-7 and drug-resistant MCF-7/ADR cells. P-Glycoprotein inhibition by TPGS and folate-mediated targeted delivery helped overcome multidrug resistance (MDR) and increase the therapeutic efficiency of the drug, leading to good anticancer effects in the MCF-7/ADR xenograft model. Overall, the folate-modified redox/pH-sensitive hybrid micelles provided a three-step approach to enhance anticancer activities via targeted delivery, controlled release, and depressed drug efflux; thus, these micelles may be a powerful weapon against MDR cancers in the future.