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The use of visual features in audio-visual speech recognition (AVSR) is justified by both the speech generation mechanism, which is essentially bimodal in audio and visual representation, and by the need for features that are invariant to acoustic noise perturbation. As a result, current AVSR systems demonstrate significant accuracy improvements in environments affected by acoustic noise. In this paper, we describe the use of two statistical models for audio-visual integration, the coupled HMM (CHMM) and the factorial HMM (FHMM), and compare the performance of these models with the existing models used in speaker dependent audio-visual isolated word recognition. The statistical properties of both the CHMM and FHMM allow to model the state asynchrony of the audio and visual observation sequences while preserving their natural correlation over time. In our experiments, the CHMM performs best overall, outperforming all the existing models and the FHMM.

China has experienced successive waves of dengue epidemics over the past decade. Nationwide data on 95,339 dengue cases, 89 surveillance sites for mosquito density and population mobility between 337 cities during 2013-20 were extracted. Weekly dengue time series including time trends and harmonic terms were fitted using seasonal regression models, and the amplitude and peak timing of the annual and semiannual cycles were estimated. A data-driven model-inference approach was used to simulate the epidemic at city-scale and estimate time-evolving epidemiological parameters. We found that the geographical distribution of dengue cases was expanding, and the main imported areas as well as external sources of imported cases changed. Dengue cases were predominantly concentrated in southern China and it exhibited an annual peak of activity, typically peaking in September. The annual amplitude of dengue epidemic varied with latitude ( F  = 19.62, P  = 0.0001), mainly characterizing by large in southern cities and small in northern cities. The effective reproduction number R eff across cities is commonly greater than 1 in several specific months from July to November, further confirming the seasonal fluctuations and spatial heterogeneity of dengue epidemics. The results of this national study help to better informing interventions for future dengue epidemics in China. The geographical distribution of dengue in China has been expanding this century. Here, the authors report the spatiotemporal distribution of dengue in China using surveillance data from 2013–2020 and combine it with mosquito abundance and human mobility data to simulate transmission at the city scale.

Diatom is an important group of marine algae and contributes to around 20% of the global photosynthetic carbon fixation. Photosystem I (PSI) of diatoms is associated with a large number of fucoxanthin-chlorophyll a / c proteins (FCPIs). We report the structure of PSI-FCPI from a diatom Chaetoceros gracili s at 2.38 Å resolution by single-particle cryo-electron microscopy. PSI-FCPI is a monomeric supercomplex consisting of 12 core and 24 antenna subunits (FCPIs), and 326 chlorophylls a , 34 chlorophylls c , 102 fucoxanthins, 35 diadinoxanthins, 18 β -carotenes and some electron transfer cofactors. Two subunits designated PsaR and PsaS were found in the core, whereas several subunits were lost. The large number of pigments constitute a unique and huge network ensuring efficient energy harvesting, transfer and dissipation. These results provide a firm structural basis for unraveling the mechanisms of light-energy harvesting, transfer and quenching in the diatom PSI-FCPI, and also important clues to evolutionary changes of PSI-LHCI. Diatoms are marine algae with an important role in global photosynthetic carbon fixation. Here, the authors present the 2.38 Å cryo-EM structure of photosystem I (PSI) in complex with its 24 fucoxanthin chlorophyll a/c -binding (FCPI) antenna proteins from the diatom Chaetoceros gracilis , which provides mechanistic insights into light-energy harvesting, transfer and quenching of the PSI-FCPI supercomplex.

Phosphorus (P) limitation is expected to increase due to nitrogen (N)-induced terrestrial eutrophication, although most soils contain large P pools immobilized in minerals (Pi) and organic matter (Pₒ). Here we assessed whether transformations of these P pools could increase plant available pools alleviating P limitation under enhanced N availability. The mechanisms underlying these possible transformations were explored by combining results from a 10-year field N addition experiment and a 3700-km transect covering wide ranges in soil pH, soil N, aridity, leaching, and weathering that could affect soil P status in grasslands. Nitrogen addition promoted the dissolution of immobile Pi (mainly Ca-bound recalcitrant P) to more available forms of Pi (including Al- and Fe-bound P fractions and Olsen P) by decreasing soil pH from 7.6 to 4.7, but did not affect Pₒ. Soil total P declined by 10% from 385 ± 6.8 to 346 ± 9.5 mg kg−1, whereas available P increased by 546% from 3.5 ± 0.3 to 22.6 ± 2.4 mg kg−1 after the 10-year N addition, associated with an increase in Pi mobilization, plant uptake, and leaching. Similar to the N addition experiment, the drop in soil pH from 7.5 to 5.6 and increase in soil N concentration along the grassland transect were associated with an increased ratio between relatively mobile Pi and immobile Pi. Our results provide a new mechanistic understanding of the important role of soil Pi mobilization in maintaining plant P supply and accelerating biogeochemical P cycles under anthropogenic N enrichment. This mobilization process temporarily buffers ecosystem P limitation or even causes P eutrophication, but will extensively deplete soil P pools in the long run.

The electrochemical oxidation of propylene presents a promising strategy for propylene oxide (PO) synthesis, but is severely hindered by the complex reaction pathways and the low PO selectivity. In this work, a series of Ag-decorated FeOOH catalysts is designed to elucidate the reaction mechanism of the electrochemical propylene oxidation reaction for PO electrosynthesis. An optimal Faradaic efficiency of PO of 32.0% is achieved over the single-Ag-atom decorated FeOOH catalyst (Ag 1 -FeOOH) at 2.4 V versus reversible hydrogen electrode. The in-situ attenuated total reflectance surface-enhanced infrared absorption spectroscopy and in-situ 57 Fe Mössbauer spectroscopy measurements combined with density functional theory calculations reveal the dual-site synergistic catalytic mechanism for electrochemical propylene epoxidation over Ag 1 -FeOOH, where single-Ag-atom sites catalyze water oxidation to generate reactive oxygen species, while the adjacent Fe sites serve as adsorption sites for propylene activation. This study provides clear insights into the dual-site synergistic electrocatalytic mechanism of propylene epoxidation and sheds light on the rational design of single-atom catalysts for electrochemical organic synthesis. The rational design of efficient propylene epoxidation catalysts is hindered by the unclear catalytic mechanism. Here, using in-situ spectroscopy to probe the supported single-Ag-atom catalyst, the authors report a dual-site synergistic mechanism for the electrocatalytic propylene epoxidation.

Qiyong Liu and colleagues consider the experience of basic malaria elimination, resurgence, and re-elimination in the Huai River Basin in central China, as well as lessons learnt to help to inform countries and regions in their approaches to malaria control and elimination

It is generally accepted that exposure to particulate matter (PM) increases the risk of cardiovascular-related morbidity and mortality, though the exact mechanism behind this has yet to be elucidated. Oxidative stress plays a potentially important role in the mechanism of toxicity, with Nrf2 serving as a major antioxidant gene. In the current study, a Nrf2 knockout mouse model was used in combination with an individual ventilated cage (IVC)-based real-ambient PM exposure system to assess the potential cardiotoxicity induced by real-ambient PM exposure and the potential role of Nrf2 and related signaling in this endpoint. After 6- or 11-weeks exposure to PM, ICP-mass spectrometry was used to assess the metal depositions in the heart tissue following PM exposure. Functional and morphological changes in the hearts were investigated with echocardiography and histopathology, and oxidative stress levels were assessed with a serum malondialdehyde content assay. In the further mechanistic study, an RNA-seq technique was utilized to assess the gene transcription status in the hearts of C57/B6 mice exposed to PM with or without Nrf2 knockout. The expression levels of genes of interest were then further investigated with quantitative real-time PCR and western blotting. The results indicated that PM exposure resulted in significant elevation of sodium, potassium, selenium, and ferrum levels in mouse heart tissue. Meanwhile, significantly altered heart function and morphology were observed. Interestingly, Nrf2 knockout led to abolishment of PM-induced effects in several functional parameters but not the morphological changes. Meanwhile, elevated malondialdehyde content was observed in Nrf2 knockout animals. RNA-seq results revealed thousands of genes altered by PM exposure and/or Nrf2 knockout, and this affected several pathways, such as MAPK, phagosome, calcium signaling, and JAK-STAT. In subsequent molecular studies, enhanced nuclear translocation of Nrf2 was also observed following PM exposure, while the MAPK signaling pathway along with related JAK-STAT and TGF-β1 pathway genes, such as p38MAPK, AKT, TAK1, JAK1, STAT3, GRB2, TGFb1, and SMAD2, were confirmed to be affected by PM exposure and/or Nrf2 knockout. The data suggested that PM may induce cardiotoxicity in C57/B6 mice in which Nrf2 plays both protective and detrimental roles involving cardiac-related pathways, such as MAPK, JAK-STAT, and TGF-β1.

The gut microbiota (GM) has emerged as a key regulator of cancer development, therapeutic efficacy, and treatment-related toxicity. Despite rapid advances in sequencing technologies, the clinical application of GM analysis in oncology lacks standardized technical and interpretative frameworks. To address this need, the Tumor and Microecology Professional Committee of the Chinese Anti-Cancer Association developed the Guidelines for Gut Microbiota Technology (2025 Edition). These guidelines provide standardized recommendations for GM detection technologies, including 16S rRNA gene sequencing, metagenomic sequencing, and nanopore-based approaches, covering specimen handling, laboratory procedures, bioinformatics analysis, quality control, and result interpretation. The guidelines also summarize the clinical relevance of GM assessment in cancer patients, particularly in the context of chemotherapy, immunotherapy, and hematopoietic stem cell transplantation, and propose practical considerations for integrating GM testing into oncology practice. These recommendations aim to facilitate the standardized and integrative use of GM technologies in cancer care.

β-amyloid protein (Aβ) is thought to be the primary cause of the pathogenesis of Alzheimer’s disease (AD). Niacin has been reported to have beneficial effects on AD. Previously, we synthesized a novel compound lipoicacid–niacin dimer (N2L) and revealed that it had potent blood-lipid regulation and antioxidative properties without aflushing effect. Given that lipid metabolism is also associated with AD, the present study aimed to investigate the neuroprotective effects of N2L on Aβ 1–42 -induced cytotoxicity in HT22 cells. We found that N2L significantly attenuated cell apoptosis, MDA level, ROS content, and the mitochondrial membrane potential corruption induced by Aβ 1–42 in HT22 cells. In addition, the activities of SOD, GSH-px and CAT that were decreased by Aβ 1–42 were also restored by N2L. Furthermore, N2L reduced proapoptotic signaling by increasing the expression of anti-apoptotic Bcl-2 and decreasing the protein expression of both pro-apoptotic Bax and cleaved Caspase-3. Together, these findings indicate that N2L holds great potential for neuroprotection against Aβ 1–42 -induced cytotoxicity via inhibition of oxidative stress and cell apoptosis, suggesting that N2L may be a promising agent for AD therapy.

The co-doping of silicon nanocrystals (Si NCs) with boron (B) and phosphorus (P) is an important means to tune the optical properties of Si NCs. However, all the previous work only concerns heavy co-doping. In this study, we carry out first-principles study on light co-doping that leads to the incorporation of dopants at the NC surface, rather than inside NCs. The size (diameter) of Si NCs currently investigated is ~2.2 nm. A Si NC without doping is in the form of Si 179 H 148 . It is found that the formation energy of a lightly co-doped Si NC is between those of B- and P-doped Si NCs, hardly being affected by the distance between dopants. Electron localization around P is mainly responsible for the light co-doping-induced reduction of the bandgap of Si NCs. The redshifts of excitation- and emission-energy induced by light co-doping is slightly larger than those induced by B and P doping in most cases. The band-edge radiative recombination rates of undoped, B-doped, P-doped, and lightly co-doped Si NCs have been compared.