Explore the vast range of titles available.

Biochar-based controlled release nitrogen fertilizers (BCRNFs) have received increasing attention due to their ability to improve nitrogen-use efficiency (NUE) and increase crop yields. We previously developed a novel BCRNF, but its effects on soil microbes, NUE, and crop yields have not been reported. Therefore, we designed a pot experiment with five randomised treatments: CK (without urea and biochar), B (addition biochar without urea), B + U (biochar mixed urea), Urea (addition urea without biochar), and BCRNF (addition BCRNF), to investigate the effects of BCRNF on nitrifiers and denitrifiers, and how these impact nitrogen supply and NUE. Results of high-throughput sequencing revealed bacterial community groups with higher nutrient metabolic cycling ability under BCRNF treatment during harvest stage. Compared to Urea treatment, BCRNF treatment stimulated nitrification by increasing the copy number of the bacterial amoA gene and reducing nitrous oxide emission by limiting the abundance of nirS and nirK . Eventually, BCRNF successfully enhanced the yield (~ 16.6%) and NUE (~ 58.79%) of rape by slowly releasing N and modulating the abundance of functional microbes through increased soil nitrification and reduced denitrification, as compared with Urea treatment. BCRNF significantly improved soil NO 3 − , leading to an increase in N uptake by rape and NUE, thereby promoting rape growth and increasing grain yield.

Microbes regulate the composition and turnover of organic matter. Here we developed a framework called Energy-Diversity-Trait integrative Analysis to quantify how dissolved organic matter and microbes interact along global change drivers of temperature and nutrient enrichment. Negative and positive interactions suggest decomposition and production processes of organic matter, respectively. We applied this framework to manipulative field experiments on mountainsides in subarctic and subtropical climates. In both climates, negative interactions of bipartite networks were more specialized than positive interactions, showing fewer interactions between chemical molecules and bacterial taxa. Nutrient enrichment promoted specialization of positive interactions, but decreased specialization of negative interactions, indicating that organic matter was more vulnerable to decomposition by a greater range of bacteria, particularly at warmer temperatures in the subtropical climate. These two global change drivers influenced specialization of negative interactions most strongly via molecular traits, while molecular traits and bacterial diversity similarly affected specialization of positive interactions. Microbes are intimately linked with the fate of organic matter. Here the authors develop an ecological network framework and show how microbes and dissolved organic matter interact along global change drivers of temperature and nutrient enrichment via manipulative field experiments on mountains.

Although biodiversity and ecosystem functions are strongly shaped by contemporary environments, such as climate and local biotic and abiotic attributes, relatively little is known about how they depend on long-term geological processes. Here, along a 3000-m elevational gradient with tectonic faults on the Tibetan Plateau (that is, Galongla Mountain in Medog County, China), we study the joint effects of geological and contemporary environments on biological communities, such as the diversity and community composition of plants and soil bacteria, and ecosystem functions. We find that these biological communities and ecosystem functions generally show consistent elevational breakpoints at 2000–2800 m, which coincide with Indus-Yalu suture zone fault and are similar to the elevational breakpoints of soil bacteria on another mountain range 1000 km away. Mean annual temperature, soil pH and moisture are the primary contemporary determinants of biodiversity and ecosystem functions, which support previous findings. However, compared with the models excluding geological processes, inclusion of geological effects, such as parent rock and weathering, increases 67.9 and 35.9% of the explained variations in plant and bacterial communities, respectively. Such inclusion increases 27.6% of the explained variations in ecosystem functions. The geological processes thus provide additional links to ecosystem properties, which are prominent but show divergent effects on biodiversity and ecosystem functions: parent rock and weathering exert considerable direct effects on biodiversity, whereas indirectly influence ecosystem functions via interactions with biodiversity and contemporary environments. Thus, the integration of geological processes with environmental gradients could enhance our understanding of biodiversity and, ultimately, ecosystem functioning across different climatic zones.

The diversity of intrinsic traits of different organic matter molecules makes it challenging to predict how they, and therefore the global carbon cycle, will respond to climate change. Here we develop an indicator of compositional-level environmental response for dissolved organic matter to quantify the aggregated response of individual molecules that positively and negatively associate with warming. We apply the indicator to assess the thermal response of sediment dissolved organic matter in 480 aquatic microcosms along nutrient gradients on three Eurasian mountainsides. Organic molecules consistently respond to temperature change within and across contrasting climate zones. At a compositional level, dissolved organic matter in warmer sites has a stronger thermal response and shows functional reorganization towards molecules with lower thermodynamic favorability for microbial decomposition. The thermal response is more sensitive to warming at higher nutrients, with increased sensitivity of up to 22% for each additional 1 mg L -1 of nitrogen loading. The utility of the thermal response indicator is further confirmed by laboratory experiments and reveals its positive links to greenhouse gas emissions. The response of organic molecules to climate change is linked to warming, nutrient loading, and greenhouse gas emissions, according to an indicator developed to quantify the aggregated thermal response of individual organic molecules.

The topological states of matter and topological materials have been attracting extensive interests as one of the frontier topics in condensed matter physics and materials science since the discovery of quantum Hall effect in 1980s. So far all the topological phases such as integer quantum Hall effect and topological insulators are characterized by integer topological invariants. None is a half integer or fractional. Here we propose a type of semimetals which hosts a single cone of Wilson fermions. The Wilson fermions possess linear dispersion near the Dirac point, but break the chiral or parity symmetry such that an unpaired Dirac cone can be realized on a lattice. In order to avoid the fermion doubling problem, the chiral symmetry or parity symmetry must be broken explicitly if the hermiticity, locality and translational invariance all hold. We find that the system can be classified by the relative homotopy group, and a half-integer topological invariant. We term the nontrivial quantum phase as quantum anomalous semimetal. The work opens the door towards exploring novel states of matter with fractional topological charge.

Clarifying the complex relationships among ecosystem services (ESs) and the driving mechanisms of ecosystem service (ES) is essential for supporting regional ES and ecological sustainability. Although studies on ES relationships provide guidance for regional ecological management, the driving mechanisms of ES have not been adequately studied, especially in areas with complex natural environments and progressive urbanization. Combined with the data on land use, climate, NDVI, and soil data, this paper aims to explore this issue by analyzing the relationships among ESs and the driving mechanisms of ESs in the western Sichuan Plateau region of China. Firstly, the temporal and spatial distribution characteristics of five ecosystem services (food supply, water supply, habitat quality, soil conservation, and carbon storage) from 2000 to 2020 were analyzed by the InVEST model. Second, the trade-offs/synergistic relationships among ESs were analyzed using SPSS as well as the Pearson product-moment correlation coefficient method in MATLAB. Finally, the Geodetector model was further used to reveal the influencing factors of ecosystem services in the western Sichuan Plateau. The results showed that: (1) Water supply decreased in the western Sichuan Plateau from 2000 to 2020, but increased in the eastern part; habitat quality was generally good in the whole Sichuan Plateau, but decreased in some areas; carbon storage showed an overall improving trend; soil conservation showed an overall increasing and then decreasing trend, and food supply services showed an increasing trend. (2) From 2000 to 2020, food supply and other services in the western Sichuan Plateau were in a trade-off relationship; all other service pairs showed a synergistic relationship. (3) In terms of space, the relationships between ecosystem services showed spatial heterogeneity. There was a synergistic relationship between food supply and habitat quality in some areas, such as Litang County and Xinlong County, and there was a trade-off relationship between water supply and carbon storage services in some areas, such as Ruoergai County and Daocheng County, etc. (4) The Geodetector results showed that food supply and soil conservation were mainly influenced by the slope (0.682, 0.672), annual precipitation was the strongest explanation for water supply (0.967), and habitat quality and carbon storage were the most influenced by NDVI (0.876, 0.828); meanwhile, each ecosystem service was interactively influenced by multiple factors. Based on the results, we proposed ecological management recommendations for the western Sichuan Plateau, the most important one being that the western Sichuan Plateau should protect and rationally use the existing natural resources, especially the existing forest and grassland resources, and at the same time reform the agricultural structure and scientifically plan urban development, to promote the coexistence of cities and nature. We took the western Sichuan Plateau of China, where urbanization and a complex natural environment are in opposition, as an example, to explore its ecosystem services, relationships, and driving mechanisms, and then put forward suggestions on ecological management and control, providing a reference for future regional coordination between urbanization and the natural environment.

Streets play a crucial role in the pedestrian catchment area (PCA) of metro stations. However, the large-scale quality measurement of street space and its influence on the vitality of station area have not been well revealed. With multisource big data such as points of interest (POI), and street view images, a three-dimensional evaluation system based on the pyramid scene parsing network (PSPNet) and spatial design network analysis (sDNA) is constructed. 73 metro stations in the Third Ring Road of Chengdu are chosen as research samples to carry out large-scale quantitative evaluation of street space in PCAs to reveal the quality characteristics of street space at the overall urban, PCA, and circle scales. Furthermore, this study constructs two multiple linear regression models of weekdays and weekends to explore the relationship between urban vitality and street space quality indicators. The results indicate a heterogeneous distribution of street quality on an urban scale. Streets located in the 300–500 m of PCAs rate highest in terms of convenience and the overall street space quality. The functionality dimension of street spaces in the sample PCAs of Chengdu present a gradient effect with the highest score of 0–300 m in the circle, while the comfortability dimension of streets shows an opposite trend. The multiple linear regression analysis show that street quality indicators are more explanatory of the weekday vitality than the weekend vitality. It indicates that well-connected street network, pleasant street scale, and abundant urban facilities have the greatest effect on urban vitality in the PCAs. The findings can provide new ideas for making targeted interventions in the urban design of metro station areas, to improve the quality of streets and foster urban vitality.

Objective The role of cell death‐inducing DFF45‐like effector C (CIDEC) in insulin resistance has been established, and it is considered to be an important trigger factor for the progression of diabetic nephropathy (DN). We intend to explore whether CIDEC plays an important role in the regulation of DN and its potential mechanism. Methods High‐fat diet and low dose streptozotocin were used to establish type 2 diabetic rat model. We investigate the role of CIDEC in the pathogenesis and process of DN through histopathological analysis, western blot and gene silencing. Meanwhile, the effect of CIDEC on renal tubular epithelial cells stimulated by high glucose was also verified. Results DM group exhibited glucose and lipid metabolic disturbance, with hypertrophy of kidneys, damaged renal function, increased apoptosis, decreased autophagy, glomerulosclerosis and interstitial fibrosis. CIDEC gene silencing improved metabolic disorder and insulin resistance, alleviated renal hypertrophy and renal function damage, decreased glomerular and tubular apoptosis, increased autophagy and inhibited renal fibrosis. At the cellular level, high glucose stimulation increased CIDEC expression in renal tubular epithelial cells, accompanied by increased apoptosis and decreased autophagy. CIDEC gene silencing can improve autophagy and reduce apoptosis. At the molecular level, CIDEC gene silencing also decreased the expression of early growth response factor (EGR)1 and increased the expression of adipose triglyceride lipase (ATGL). Conclusion CIDEC gene silencing may delay the progression of DN by restoring autophagy activity and inhibiting apoptosis with the participation of EGR1and ATGL. In diabetic rats, CIDEC gene silencing may prevent apoptosis by inhibiting the expression of EGR1, while restore autophagy activity and inhibit apoptosis by increasing the expression of ATGL, thereby improving renal glomerulosclerosis and tubulointerstitial fibrosis and delaying the progression of DN. CIDEC may be a valuable new target for DN treatment.

Background: The chemotherapeutic doxorubicin (DOX) promotes severe skeletal muscle atrophy, which induces skeletal muscle weakness and fatigue. Soluble guanylate cyclase (sGC) contributes to a variety of pathophysiological processes, but whether it is involved in DOX-induced skeletal muscle atrophy is unclear. The present study aimed to stimulate sGC by vericiguat, a new oral sGC stimulator, to test its role in this process. Methods: Mice were randomly divided into four groups: control group, vericiguat group, DOX group, and DOX + vericiguat group. Exercise capacity was evaluated before the mice were sacrificed. Skeletal muscle atrophy was assessed by histopathological and molecular biological methods. Protein synthesis and degradation were monitored in mice and C2C12 cells. Results: In this study, a significant decrease in exercise capacity and cross-sectional area (CSA) of skeletal muscle fibers was found in mice following DOX treatment. Furthermore, DOX decreased sGC activity in mice and C2C12 cells, and a positive correlation was found between sGC activity and CSA of skeletal muscle fibers in skeletal muscle. DOX treatment also impaired protein synthesis, shown by puromycin detection, and activated ubiquitin-proteasome pathway. Following sGC stimulation, the CSA of muscle fibers was elevated, and exercise capacity was enhanced. Stimulation of sGC also increased protein synthesis and decreased ubiquitin-proteasome pathway. In terms of the underlying mechanisms, AKT/mTOR and FoxO1 pathways were impaired following DOX treatment, and stimulation of sGC restored the blunted pathways. Conclusion: These results unravel sGC stimulation can improve skeletal muscle atrophy and increase the exercise capacity of mice in response to DOX treatment by enhancing protein synthesis and inhibiting protein degradation. Stimulation of sGC may be a potential treatment of DOX-induced skeletal muscle dysfunction.

Software-defined radio (SDR) is a good solution for complying with the existing and incoming protocols for emerging wireless sensor networks (WSN) and internet of things (IoT) applications. The frequency synthesizer in a SDR tranceiver usually consists of a phase locked loop (PLL) and a post synthesizer. The PLL is the narrow band signal source and the post synthesizer generates wideband outputs by mixing and dividing. Compared with a frequency synthesizer utilizing the wideband PLL, this synthesizer features relatively constant loop parameters and mitigates the requirement for the oscillator. In this paper, a quadrature single side-band (QSSB) mixer with the proposed passive negative resistance (PNR) for frequency mixing in a post synthesizer is presented. The PNR is achieved by biasing the Metal-Oxide-Semiconductor Field-Effect Transistors (MOSFET) of the cross-coupled pair at the deep-triode region periodically and incorporates an inductor and a cap-array as the mixer load. Compared with the traditional single side-band mixers utilizing Inductor-Capacitor (LC) resonant loads or quality factor enhanced (Q-enhanced) LC resonant loads, which suffer from a selectivity versus working range trade-off, the mixer employing the proposed loading structure provides not only a wide operating range, but also a superior image side-band rejection ratio (ISRR). Moreover, the oscillating risk in conventional mixers adopting Q-enhanced LC resonant loads is eliminated. A wideband frequency synthesizer employing the proposed mixer was implemented in a TSMC 0.18 µm CMOS process and the mixer performed ISRR of 40–57 dB and 30–57 dB across 2.5–3 GHz and 2.3–3.2 GHz, respectively. The power consumption of the QSSB mixer, including buffer, is 18 mA from a 1.8 V supply and the active area is 0.445 mm2. The measurement results provide validation that the proposed QSSB mixer is suitable for wideband software-defined frequency synthesizers and other frequency generating systems.