13 research outputs found
Response of Plant Root Growth to Biochar Amendment: A Meta-Analysis
No full textBiochar is widely used in agriculture to improve soil fertility and plant growth. However, a comprehensive assessment of how biochar amendment affects plant root growth is lacking. This study investigated the change in plant root biomass in response to biochar application, including impact factors such as the biochar feedstock and application rate, plant type, and soil pH. The Science Direct, Web Of Science, and Scopus databases were employed to search for literature published before 2021. The published papers with at least three replicates of biochar-amended treatments and a control at the same site were selected for meta-analysis. Our results showed that 165 (81.3%) of 203 datasets from 47 published studies indicated positive effects of biochar amendment on root growth with a mean relative increase of 32%. The feedstocks of biochar and its rate of application were the main factors that determined its effects on plant root growth. The increment of root biomass following biochar amendment was the greatest for trees (+101.6%), followed by grasses (+66.0%), vegetables (+26.9%), and cereals (+12.7%). The positive effects mainly depended on feedstock sources, with the highest positive effect (+46.2%) for gramineous, followed by woody plants (+25.8%) and green wastes (+21.1%). Linear regression analysis and SEM (Structural equation modeling) analysis showed that total nitrogen (TN) and available phosphorus (AK) are one of the most important factors affecting the increase of root biomass. These results suggest that biochar can be considered an effective amendment to improve root growth and soil fertility. Biochar feedstock sources, application rates, and plant types should be considered to assess the potential benefits of biochar for root growth and soil quality
Study on the mechanism of Wnt/β-catenin pathway mediated by pterostilbene to reduce cerebral ischemia-reperfusion injury
No full textCerebral ischemia-reperfusion injury (CIRI) is the primary cause of damage following ischemic stroke, with ferroptosis serving as a key pathophysiological factor in CIRI. Pterostilbene (PTE) has been shown to reduce cerebral ischemic injury, but whether its mechanism of action involves ferroptosis remains unclear. In this study, an in vitro model of mouse hippocampal neuron (HT22) cell injury and an in vivo mouse CIRI model were established. Treatments included PTE, the ferroptosis activator Erastin, and the Wnt signaling pathway inhibitor (Dkk-1). Cell damage was assessed using flow cytometry, MTT assay, LDH release assay, and Calcein-AM/PI staining. Oxidative stress and ferroptosis in cells and tissues were evaluated using biochemical kits and fluorescence staining. Additionally, histopathological staining was performed to assess brain tissue damage, while qRT-PCR and Western blot analyses were used to measure ferroptosis-related factors and Wnt/β-catenin pathway-related proteins in both cells and tissues. HT22 cells subjected to injury exhibited decreased viability and increased cell death (P < 0.05). Similarly, CIRI mice demonstrated pronounced cerebral infarction and neuronal damage. Ferroptosis, characterized by elevated levels of iron ions, lipid peroxides (ROS and MDA), and reduced antioxidant enzymes (GSH and GPX4), was significantly increased in both cells and tissues (P < 0.05). Correspondingly, ferroptosis-related protein levels were elevated (P < 0.05), while Wnt/β-catenin pathway-related protein levels were significantly decreased (P < 0.05). Treatment with Erastin and Dkk-1 exacerbated neuronal damage, intensified ferroptosis, and inhibited the Wnt/β-catenin pathway. Conversely, PTE treatment activated the Wnt/β-catenin pathway, reduced ferroptosis, and improved neuronal damage. Specifically, PTE upregulated the Wnt/β-catenin pathway, decreased peroxide accumulation, and antagonized ferroptosis, ultimately mitigating CIRI. These findings suggest that PTE protects against CIRI by modulating the Wnt/β-catenin pathway and alleviating ferroptosis-induced damage
Sample sizes (<i>n</i>) and diversity indices for the chiru (<i>Pantholops hodgsonii</i>) and Tibetan gazelle (<i>Procapra picticaudata</i>).
No full text<p>Total number of haplotypes per species, mean nucleotide diversity (<i>π</i>), mean haplotype diversity (<i>h</i>), Fu's <i>Fs</i> and Fu and Li's <i>D*</i> were from mtDNA sequences; total number of alleles per species (<i>k</i>), expected heterozygosity (<i>H</i><sub>E</sub>) and observed heterozygosity (<i>H</i><sub>O</sub>) were based on nine nuclear microsatellite loci.</p
A Hyper-Pseudoelastic Model of Cyclic Stress-Softening Effect for Rubber Composites
No full textRubber composites are hyperelastic materials with obvious stress-softening effects during the cyclic loading–unloading process. In previous studies, it is hard to obtain the stress responses of rubber composites at arbitrary loading–unloading orders directly. In this paper, a hyper-pseudoelastic model is developed to characterize the cyclic stress-softening effect of rubber composites with a fixed stretch amplitude at arbitrary loading–unloading order. The theoretical relationship between strain energy function and cyclic loading–unloading order is correlated by the hyper-pseudoelastic model directly. Initially, the basic laws of the cyclic stress-softening effect of rubber composites are revealed based on the cyclic loading–unloading experiments. Then, a theoretical relationship between the strain energy evolution function and loading–unloading order, as well as the pseudoelastic theory, is developed. Additionally, the basic constraints that the strain energy evolution function must satisfy in the presence or absence of residual deformation effect are derived. Finally, the calibration process of material parameters in the hyper-pseudoelastic model is also presented. The validity of the hyper-pseudoelastic model is demonstrated via the comparisons to experimental data of rubber composites with different filler contents. This paper presents a theoretical model for characterizing the stress-softening effect of rubber composites during the cyclic loading–unloading process. The proposed theoretical model can accurately predict the evolution of the mechanical behavior of rubber composites with the number of loading–unloading cycles, which provides scientific guidance for predicting the durability properties and analyzing the fatigue performance of rubber composites
Metabonomics study of the protective effects of green tea polyphenols on aging rats induced by d-galactose
No full textVivim: a Video Vision Mamba for Medical Video Segmentation
No full textMedical video segmentation gains increasing attention in clinical practice due to the redundant dynamic references in video frames. However, traditional convolutional neural networks have a limited receptive field and transformer-based networks are mediocre in constructing long-term dependency from the perspective of computational complexity. This bottleneck poses a significant challenge when processing longer sequences in medical video analysis tasks using available devices with limited memory. Recently, state space models (SSMs), famous by Mamba, have exhibited impressive achievements in efficient long sequence modeling, which develops deep neural networks by expanding the receptive field on many vision tasks significantly. Unfortunately, vanilla SSMs failed to simultaneously capture causal temporal cues and preserve non-casual spatial information. To this end, this paper presents a Video Vision Mamba-based framework, dubbed as Vivim, for medical video segmentation tasks. Our Vivim can effectively compress the long-term spatiotemporal representation into sequences at varying scales with our designed Temporal Mamba Block. We also introduce an improved boundary-aware affine constraint across frames to enhance the discriminative ability of Vivim on ambiguous lesions. Extensive experiments on thyroid segmentation, breast lesion segmentation in ultrasound videos, and polyp segmentation in colonoscopy videos demonstrate the effectiveness and efficiency of our Vivim, superior to existing methods. The code is available at: https://github.com/scott-yjyang/Vivim. The dataset will be released once accepted
Vivim: a Video Vision Mamba for Ultrasound Video Segmentation
No full textUltrasound video segmentation gains increasing attention in clinical practice due to the redundant dynamic references in video frames. However, traditional convolutional neural networks have a limited receptive field and transformer-based networks are unsatisfactory in constructing long-term dependency from the perspective of computational complexity. This bottleneck poses a significant challenge when processing longer sequences in medical video analysis tasks using available devices with limited memory. Recently, state space models (SSMs), famous by Mamba, have exhibited linear complexity and impressive achievements in efficient long sequence modeling, which have developed deep neural networks by expanding the receptive field on many vision tasks significantly. Unfortunately, vanilla SSMs failed to simultaneously capture causal temporal cues and preserve non-casual spatial information. To this end, this paper presents a Video Vision Mamba-based framework, dubbed as Vivim, for ultrasound video segmentation tasks. Our Vivim can effectively compress the long-term spatiotemporal representation into sequences at varying scales with our designed Temporal Mamba Block. We also introduce an improved boundary-aware affine constraint across frames to enhance the discriminative ability of Vivim on ambiguous lesions. Extensive experiments on thyroid segmentation in ultrasound videos, breast lesion segmentation in ultrasound videos, and polyp segmentation in colonoscopy videos demonstrate the effectiveness and efficiency of our Vivim, superior to existing methods.</p
Long-Term Agricultural Management Alters Soil Fungal Communities and Soil Carbon and Nitrogen Contents in Tea Plantations
No full textSoil carbon (C) and nitrogen (N) are vital for enhancing tea production and ensuring the sustainability of tea plantation ecosystems. However, research on the dynamics of soil C and N pools and their associated microbial mechanisms in tea plantations with varying cultivation durations is scarce. We compared soil samples from a forest and two tea plantations—young established (YTP) and century-old (OTP)—to assess changes in soil C and N concentrations and the impact of fungal community structure on these elements. Soil organic carbon (SOC) and total nitrogen (TN) were markedly higher in OTP than in the YTP and forest (65.9% and 30.1%, respectively, relative to YTP). Eurotiomycetes in the YTP group accounted for a relatively higher proportion at 51.6%, surpassing its presence in both the forest (14.3%) and OTP (4.78%) groups and it can be the main microbial factor affecting the C cycle in tea plantation soils and facilitating SOC mineralization. Enhancing planting years or changing land use patterns improves fertilizer and biomass sedimentation and increases the relative abundance of Eurotiomycetes in the soil and the C sink potential of tea plantations. This study provides valuable insights into the role of soil C and N dynamics and fungal communities in tea plantation ecosystems, highlighting the importance of managing these factors for sustainable tea production
Mechanistic study of visible light-driven CdS or g-C<sub>3</sub>N<sub>4</sub>-catalyzed C–H direct trifluoromethylation of (hetero)arenes using CF<sub>3</sub>SO<sub>2</sub>Na as the trifluoromethyl source
No full textThe mild and sustainable methods for C–H direct trifluoromethylation of (hetero)arenes without any base or strong oxidants are in extremely high demand. Here, we report that the photo-generated electron-hole pairs of classical semiconductors (CdS or g-C3N4) under visible light excitation are effective to drive C–H trifluoromethylation of (hetero)arenes with stable and inexpensive CF3SO2Na as the trifluoromethyl (TFM) source via radical pathway. Either CdS or g-C3N4 propagated reaction can efficiently transform CF3SO2Na to [rad]CF3 radical and further afford the desired benzotrifluoride derivatives in moderate to good yields. After visible light initiated photocatalytic process, the key elements (such as F, S and C) derived from the starting TFM source of CF3SO2Na exhibited differential chemical forms as compared to those in other oxidative reactions. The photogenerated electron was trapped by chemisorbed O2 on photocatalysts to form superoxide radical anion (O2[rad]−) which will further attack [rad]CF3 radical with the generation of inorganic product F− and CO2. This resulted in a low utilization efficiency of [rad]CF3 (<50%). When nitro aromatic compounds and CF3SO2Na served as the starting materials in inert atmosphere, the photoexcited electrons can be directed to reduce the nitro group to amino group rather than being trapped by O2. Meanwhile, the photogenerated holes oxidize SO2CF3− into [rad]CF3. Both the photogenerated electrons and holes were engaged in reductive and oxidative paths, respectively. The desired product, trifluoromethylated aniline, was obtained successfully via one-pot free-radical synthesis.</p
Increased Soil Fertility in Tea Gardens Leads to Declines in Fungal Diversity and Complexity in Subsoils
No full textSoil fungi are key drivers regulating processes between ecosystem fertility and plant growth; however, the responses of soil fungi community composition and diversity in deeper soil layers to the plantation and fertilization remain limited. Using soil samples along with vertical soil profile gradients with 0–10 cm, 0–20 cm, 20–40 cm, and 40–60 cm in a tea garden, we used Illumina sequencing to investigate the fungal diversity and assemblage complexity, and correlated to the low, middle, and high-level fertilize levels. The results showed that the fungal community dissimilarities were different between adjacent forests and tea gardens, with predominate groups changed from saprotrophs to symbiotrophs and pathotrophs after the forest converted to the tea garden. Additionally, the symbiotrophs were more sensitive to soil fertility than pathotrophs and saprotrophs. Subsoil fungal communities present lower diversity and fewer network connections under high soil fertility, which contrasted with the trends of topsoil fungi. Soil pH and nutrients were correlated with fungal diversity in the topsoils, while soil K and P concentrations showed significant effects in the subsoil. Overall, the soil fungal communities in tea gardens responded to soil fertility varied with soil vertical spatial locations, which can be explained by the vertical distribution of fungal species. It was revealed that fertility treatment could affect fungal diversity, and alter network structure and potential ecosystem function in tea garden subsoils
