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The continuous promotion of low-carbon energy has made power electronic power systems a hot research topic at present. To help keep the grid running stable, a primary frequency modulation control model involving multiple types of power electronic power sources is constructed. A frequency response model for power systems is proposed to address the poor accuracy in inertia assessment, and its frequency characteristics are quantitatively analyzed. The results showed that the stable output power of wind turbines was 48.6 MW, the stable output power of energy storage systems was 7.8 MW, and the stable output power of flexible direct current transmission was 18.9 MW. Under the frequency modulation control strategy, as the droop coefficient increased, the steady-state frequency deviation increased by 0.46%, and the safety margin of steady-state frequency deviation increased by 12%. Compared with the separate frequency modulation of thermal power, the maximum frequency deviation of wind power, energy storage, and flexible direct current participating in frequency modulation was increased by 30.36%, and the steady-state frequency was increased by 27.38%. The proposed model can quantify the frequency response characteristics of the power system more accurately, and improve the frequency stability and operation safety under high penetration of renewable energy. It is of great significance to realize the low-carbon and sustainable development of power system.

Future climate change will lead to extreme weather events, such as droughts, which may exacerbate forest fire regimes. However, the impact of future drought characteristics on forest fire regimes has rarely been reported in China. Here, we employed principal component analysis to reduce the dimensionality of drought characteristics, and then used geographically weighted logistic regression models to develop predictive models. These models were applied to future climate simulations under different scenarios to provide projections for different periods, which were then compared with the historical period (2000-2019) to assess the relative changes. We found that the model performed well in its predictions (AUC > 0.75). By comparing the Brier scores, it was found that the models with better predictive performance were those using the SPEI-1 and SPEI-12 timescales. We also found that in the near and medium term of the future, with climate change, the forest fire occurrence probability in most forest land of northern China (NWC, NC, and NEC), especially in Northeast China (NEC), shows an increasing trend, but a decreasing trend in most forest land of southern China (SC, SWC, and EC). Our research can provide a scientific basis for the development of future forest fire management practices that mitigate drought stress according to local conditions.

Fructose, especially industrial fructose (sucrose and high fructose corn syrup) is commonly used in all kinds of beverages and processed foods. Liver is the primary organ for fructose metabolism, recent studies suggest that excessive fructose intake is a driving force in non-alcoholic fatty liver disease (NAFLD). Dietary fructose metabolism begins at the intestine, along with its metabolites, may influence gut barrier and microbiota community, and contribute to increased nutrient absorption and lipogenic substrates overflow to the liver. Overwhelming fructose and the gut microbiota-derived fructose metabolites (e.g., acetate, butyric acid, butyrate and propionate) trigger the de novo lipogenesis in the liver, and result in lipid accumulation and hepatic steatosis. Fructose also reprograms the metabolic phenotype of liver cells (hepatocytes, macrophages, NK cells, etc.), and induces the occurrence of inflammation in the liver. Besides, there is endogenous fructose production that expands the fructose pool. Considering the close association of fructose metabolism and NAFLD, the drug development that focuses on blocking the absorption and metabolism of fructose might be promising strategies for NAFLD. Here we provide a systematic discussion of the underlying mechanisms of dietary fructose in contributing to the development and progression of NAFLD, and suggest the possible targets to prevent the pathogenetic process.

Berberine is a natural plant alkaloid isolated from a diverse range of genera, it obtains anti-inflammatory, anti-obesity, and hepatoprotective properties, and is a promising agent for non-alcoholic steatohepatitis (NASH). Farnesoid X receptor (FXR) is a bile acid receptor and a drug target for NASH, however, the underlying mechanisms of berberine on regulating FXR are still unknown. In the present study, we feed mice with a 12-week high-fat diet with interval dextran sulfate sodium (0.5% in drinking water) diet to induce NASH, and treat the mice with berberine (100 mg/kg per day) via oral gavage for additional 4 weeks. We demonstrate that administration of berberine alleviates steatosis and infiltration of inflammatory cells in the liver of NASH mice. We apply 16S ribosomal DNA sequencing to screen the structure of gut microbiota, and ultra-performance liquid chromatography-tandem mass spectrometry analysis to determine the bile acid profiles. The results show that berberine modulates gut dysbiosis, and specifically increases the relative abundance of Clostridiales , Lactobacillaceae, and Bacteroidale . Berberine modulated microbiomes are associated with bile acid de-conjugation and transformation, which are consistent with the altered bile acid species (e.g., deoxycholic acid, ursodeoxycholic acid) upon berberine treatment. BA species that respond to berberine treatment are known FXR agonists, thus we performed quantitative Real Time-PCR and western blot to examine the FXR pathway, and find that berberine up-regulates intestinal FXR and fibroblast growth factor 15 (FGF15) expression, and the secretion of FGF15 further inhibits lipogenesis and nuclear factor-κB activation in the liver. Whereas the beneficial effects of berberine are blunted in FXR knockout mice. Our results reveal that berberine alleviates NASH by modulating the interplay of gut microbiota and bile acid metabolism, as well as the subsequent intestinal FXR activation.

Following wood pyrolysis, tar ball aerosols were laboratory generated from wood tar separated into polar and nonpolar phases. Chemical information of fresh tar balls was obtained from a high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) and single-particle laser desorption/resonance enhanced multiphoton ionization mass spectrometry (SP-LD-REMPI-MS). Their continuous refractive index (RI) between 365 and 425 nm was retrieved using a broadband cavity enhanced spectroscopy (BBCES). Dynamic changes in the optical and chemical properties for the nonpolar tar ball aerosols in NOx-dependent photochemical process were investigated in an oxidation flow reactor (OFR). Distinct differences in the chemical composition of the fresh polar and nonpolar tar aerosols were identified. Nonpolar tar aerosols contain predominantly high-molecular weight unsubstituted and alkyl-substituted polycylic aromatic hydrocarbons (PAHs), while polar tar aerosols consist of a high number of oxidized aromatic substances (e.g., methoxy-phenols, benzenediol) with higher O : C ratios and carbon oxidation states. Fresh tar balls have light absorption characteristics similar to atmospheric brown carbon (BrC) aerosol with higher absorption efficiency towards the UV wavelengths. The average retrieved RI is 1.661+0.020i and 1.635+0.003i for the nonpolar and polar tar aerosols, respectively, with an absorption Ångström exponent (AAE) between 5.7 and 7.8 in the detected wavelength range. The RI fits a volume mixing rule for internally mixed nonpolar/polar tar balls. The RI of the tar ball aerosols decreased with increasing wavelength under photochemical oxidation. Photolysis by UV light (254 nm), without strong oxidants in the system, slightly decreased the RI and increased the oxidation state of the tar balls. Oxidation under varying OH exposure levels and in the absence of NOx diminished the absorption (bleaching) and increased the O : C ratio of the tar balls. The photobleaching via OH radical initiated oxidation is mainly attributed to decomposition of chromophoric aromatics, nitrogen-containing organics, and high-molecular weight components in the aged particles. Photolysis of nitrous oxide (N2O) was used to simulate NOx-dependent photochemical aging of tar balls in the OFR. Under high-NOx conditions with similar OH exposure, photochemical aging led to the formation of organic nitrates, and increased both oxidation degree and light absorption for the aged tar ball aerosols. These observations suggest that secondary organic nitrate formation counteracts the bleaching by OH radical photooxidation to eventually regain some absorption of the aged tar ball aerosols. The atmospheric implication and climate effects from tar balls upon various oxidation processes are briefly discussed.

Rock bolting has been widely used for rock reinforcement in civil and mining engineering for a long period. In high stress rock conditions, rock bolts should not only have a high load-bearing capacity, but also should be able to accommodate large rock dilations.

With the advent of the era of big data, many companies have taken the most important steps in the hybrid cloud to handle large amounts of data. In a hybrid cloud environment, cloud burst technology enables applications to be processed at a lower cost in a private cloud and burst into the public cloud when the resources of the private cloud are exhausted. However, there are many challenges in hybrid cloud environment, such as the heterogeneous jobs, different cloud providers and how to deploy a new application with minimum monetary cost. In this paper, the efficient job scheduling approach for heterogeneous workloads in private cloud is proposed to ensure high resource utilization. Moreover, the task scheduling method based on BP neural network in hybrid cloud is proposed to ensure that the tasks can be completed within the specified deadline of the user. The experimental results show that the efficient job scheduling approach can veffectively reduce the job response time and improve the throughput of cluster. The task scheduling method can reduce the response time of tasks, improve QoS satisfaction rate and minimize the cost of public cloud.

The silkworm Bombyx mori is an important economic insect for producing silk, the “queen of fabrics”. The currently available genomes limit the understanding of its genetic diversity and the discovery of valuable alleles for breeding. Here, we deeply re-sequence 1,078 silkworms and assemble long-read genomes for 545 representatives. We construct a high-resolution pan-genome dataset representing almost the entire genomic content in the silkworm. We find that the silkworm population harbors a high density of genomic variants and identify 7308 new genes, 4260 (22%) core genes, and 3,432,266 non-redundant structure variations (SVs). We reveal hundreds of genes and SVs that may contribute to the artificial selection (domestication and breeding) of silkworm. Further, we focus on four genes responsible, respectively, for two economic (silk yield and silk fineness) and two ecologically adaptive traits (egg diapause and aposematic coloration). Taken together, our population-scale genomic resources will promote functional genomics studies and breeding improvement for silkworm. Tong et al. describe a super pangenome assembled from long-read sequences of 545 wild and domesticated silkworms. Naturally selected (diapause, aposemantic coloration) or artificially selected (silk yield and fineness) sets of genes are delineated.

The osteochondral defects (OCDs) resulting from the treatment of giant cell tumors of bone (GCTB) often present two challenges for clinicians: tumor residue leading to local recurrence and non-healing of OCDs. Therefore, this study focuses on developing a double-layer PGPC-PGPH scaffold using shell-core structure nanofibers to achieve “spatiotemporal control” for treating OCDs caused by GCTB. It addresses two key challenges: eliminating tumor residue after local excision and stimulating osteochondral regeneration in non-healing OCD cases. With a shell layer of protoporphyrin IX (PpIX)/gelatin (GT) and inner cores containing chondroitin sulfate (CS)/poly(lactic-co-glycolic acid) (PLGA) or hydroxyapatite (HA)/PLGA, coaxial electrospinning technology was used to create shell-core structured PpIX/GT-CS/PLGA and PpIX/GT-HA/PLGA nanofibers. These nanofibers were shattered into nano-scaled short fibers, and then combined with polyethylene oxide and hyaluronan to formulate distinct 3D printing inks. The upper layer consists of PpIX/GT-CS/PLGA ink, and the lower layer is made from PpIX/GT-HA/PLGA ink, allowing for the creation of a double-layer PGPC-PGPH scaffold using 3D printing technique. After GCTB lesion removal, the PGPC-PGPH scaffold is surgically implanted into the OCDs. The sonosensitizer PpIX in the shell layer undergoes sonodynamic therapy to selectively damage GCTB tissue, effectively eradicating residual tumors. Subsequently, the thermal effect of sonodynamic therapy accelerates the shell degradation and release of CS and HA within the core layer, promoting stem cell differentiation into cartilage and bone tissues at the OCD site in the correct anatomical position. This innovative scaffold provides temporal control for anti-tumor treatment followed by tissue repair and spatial control for precise osteochondral regeneration. [Display omitted] •Utilizing coaxial electrospinning, we generated shell-core structured nanofibers comprising a PpIX/GT shell layer and inner cores containing CS/PLGA or HA/PLGA.•By converting these nanofibers into short fibers, we developed distinct 3D printing inks, facilitating the creation of a double-layer PGPC-PGPH scaffold via advanced 3D printing methods.•The sonosensitizer PpIX embedded in the shell layer demonstrates targeted sonodynamic therapy, effectively damaging GCTB cells.•The specific inducing factors within the inner core precisely direct chondrogenesis in the PGPC layer and osteogenesis in the PGPH layer.•The PGPC-PGPH scaffold offers temporal control by eradicating GCTB cells followed by facilitating osteochondral regeneration, while also ensuring precise regeneration of upper cartilage and underlying bone through spatial control.