Optimal N management affects the fate of urea-15N and improves N uptake and utilization of wheat in different rotation systems

Rice-wheat and maize-wheat rotations are major cropping systems in the middle and lower reaches of Yangtze River in China, where high nitrogen (N) inputs and low N efficiency often exacerbate resource waste and environmental pollution. Due to the changes in factors such as soil properties and moisture content, the N fate and the N utilization characteristics of wheat in different rotations are significantly different. Efficient N management strategies are thus urgently required for promoting maximum wheat yield in different rotation systems while reducing N loss. A 2-year field experiment using isotopic (15N) tracer technique was conducted to evaluate the fate of 15N-labeled urea in wheat fields and the distribution characteristics of N derived from different sources. The wheat yield and N use efficiency under various N rates (180 and 240 kg ha−1, abbreviated as N180 and N240) and preceding crops (rice and maize, abbreviated as R-wheat and M-wheat) were also investigated. The results showed that N240 increased N uptake and grain yield by only 8.77−14.97% and 2.51−4.49% compared with N 180, but decreased N agronomic efficiency (NAE) and N physiological efficiency (NPE) by 14.78−18.79% and 14.06−31.35%. N240 also decreased N recovery in plants by 2.8% on average compared with N180, and increased N residue in soil and N loss to the environment. Compared with that of basal N, the higher proportion of topdressing N was absorbed by wheat rather than lost to the environment. In addition, the accumulation of topdressing N in grain was much higher than that of basal N. Compared with that in R-wheat treatment, plants in M-wheat treatment trended to absorb more 15N and reduce unaccounted N loss, resulting in higher yield potential. Moreover, the M-wheat treatment increased N recovery in 0−20 cm soil but decreased 80−100 cm soil compared with R-wheat treatment, indicating a lower risk of N loss in deeper soil. Collectively, reducing N application rate and increasing the topdressing ratio is an effective way to balance sustainable crop yield for a secure food supply and environmental benefit, which is more urgent in rice-wheat rotation

ADP-ribosyl-N3: A Versatile Precursor for Divergent Syntheses of ADP-ribosylated Compounds

Adenosine diphosphate-ribose (ADP-ribose) and its derivatives play important roles in a series of complex physiological procedures. The design and synthesis of artificial ADP-ribosylated compounds is an efficient way to develop valuable chemical biology tools and discover new drug candidates. However, the synthesis of ADP-ribosylated compounds is currently difficult due to structural complexity, easily broken pyrophosphate bond and high hydrophilicity. In this paper, ADP-ribosyl-N3 was designed and synthesized for the first time. With ADP-ribosyl-N3 as the key precursor, a divergent post-modification strategy was developed to prepare structurally diverse ADP-ribosylated compounds including novel nucleotides and peptides bearing ADP-ribosyl moieties

A low-strain V3Nb17O50 anode compound for superior Li+ storage

M–Nb–O compounds are regarded as advanced anode materials of lithium-ion batteries owing to their large capacities, high safety and fast Li transport. However, challenges remain in the exploitation of new M–Nb–O compounds with low strains to enable superior cyclability. Here, we exploit VNbO as a low-strain M–Nb–O anode compound, and VNbO micron-sized particles (VNbO-MP) and submicron-sized rods (VNbO-SR) are demonstrated. VNbO owns an open and robust shear ReO crystal structure, which is constructed by 3 ​× ​3 ​× ​∞ (V,Nb)O octahedron-blocks linked by VO tetrahedra. The resulting A–B–A layered structure with a large interlayer spacing enables the superior Li diffusivity and significant intercalation-pseudocapacitive behavior in VNbO. The maximum unit-cell volume expansion of VNbO discharged to 0.8 ​V is only 3.46% (the smallest value among the known M–Nb–O anode compounds with shear ReO structures), leading to the excellent cyclability of VNbO-MP/VNbO-SR with 90.0/91.8% capacity retention over 2000 cycles at 10C. VNbO-MP/VNbO-SR further exhibits a safe operating potential of 1.736/1.724 ​V, large reversible capacity of 207/254 ​mA ​h g at 0.1C, and high rate performance with 68/123 ​mA ​h g at 10C. A LiMnO//VNbO-SR full cell also exhibits comprehensively good electrochemical properties, including excellent cyclability with 85.7% capacity retention over 500 cycles at 5C. Therefore, VNbO can be a very promising anode compound for stable, safe, large-capacity and fast-charging Li storage

Distinct anti-oncogenic effect of various microRNAs in different mouse models of liver cancer.

Deregulation of microRNAs (miRNAs) is a typical feature of human hepatocellular carcinoma (HCC). However, the in vivo relevance of miRNAs along hepatocarcinogenesis remains largely unknown. Here, we show that liver tumors induced in mice by c-Myc overexpression or AKT/Ras co-expression exhibit distinct miRNA expression profiles. Among the downregulated miRNAs, eight (miR-101, miR-107, miR-122, miR-29, miR-365, miR-375, miR-378, and miR-802) were selected and their tumor suppressor activity was determined by overexpressing each of them together with c-Myc or AKT/Ras oncogenes in mouse livers via hydrodynamic transfection. The tumor suppressor activity of these microRNAs was extremely heterogeneous in c-Myc and AKT/Ras mice: while miR-378 had no tumor suppressor activity, miR-107, mir-122, miR-29, miR-365 and miR-802 exhibited weak to moderate tumor suppressor potential. Noticeably, miR-375 showed limited antineoplastic activity against c-Myc driven tumorigenesis, whereas it strongly inhibited AKT/Ras induced hepatocarcinogenesis. Furthermore, miR-101 significantly suppressed both c-Myc and AKT/Ras liver tumor development. Altogether, the present data demonstrate that different oncogenes induce distinct miRNA patterns, whose modulation differently affects hepatocarcinogenesis depending on the driving oncogenes. Finally, our findings support a strong tumor suppressor activity of miR-101 in liver cancer models regardless of the driver oncogenes involved, thus representing a promising therapeutic target in human HCC

Distinct anti-oncogenic effect of various microRNAs in different mouse models of liver cancer.

Deregulation of microRNAs (miRNAs) is a typical feature of human hepatocellular carcinoma (HCC). However, the in vivo relevance of miRNAs along hepatocarcinogenesis remains largely unknown. Here, we show that liver tumors induced in mice by c-Myc overexpression or AKT/Ras co-expression exhibit distinct miRNA expression profiles. Among the downregulated miRNAs, eight (miR-101, miR-107, miR-122, miR-29, miR-365, miR-375, miR-378, and miR-802) were selected and their tumor suppressor activity was determined by overexpressing each of them together with c-Myc or AKT/Ras oncogenes in mouse livers via hydrodynamic transfection. The tumor suppressor activity of these microRNAs was extremely heterogeneous in c-Myc and AKT/Ras mice: while miR-378 had no tumor suppressor activity, miR-107, mir-122, miR-29, miR-365 and miR-802 exhibited weak to moderate tumor suppressor potential. Noticeably, miR-375 showed limited antineoplastic activity against c-Myc driven tumorigenesis, whereas it strongly inhibited AKT/Ras induced hepatocarcinogenesis. Furthermore, miR-101 significantly suppressed both c-Myc and AKT/Ras liver tumor development. Altogether, the present data demonstrate that different oncogenes induce distinct miRNA patterns, whose modulation differently affects hepatocarcinogenesis depending on the driving oncogenes. Finally, our findings support a strong tumor suppressor activity of miR-101 in liver cancer models regardless of the driver oncogenes involved, thus representing a promising therapeutic target in human HCC

The challenge of maintaining microscopist capacity at basic levels for malaria elimination in Jiangsu Province, China

Abstract Background Local malaria transmission has decreased rapidly since the National Malaria Elimination Action Plan was launched in China in 2010. However, imported malaria cases from Africa and Southeast Asia still occur in China due to overseas laborers. Diagnosis by microscopy is the gold standard for malaria and is used in most hospitals in China. However, the current capacity of microscopists to manage malaria cases in hospitals and public health facilities to meet the surveillance needs to eliminate and prevent the reintroduction of malaria is unknown. Methods Malaria diagnoses were assessed by comparing the percentage of first visit and confirmed malaria diagnoses at Centers for Disease Control and Prevention (CDCs) and hospitals. The basic personnel information for public health departments and hospitals at different levels was investigated. The skills of microscopists for blood smear preparation and slide interpretation were also examined at the county and township levels. Results Inaccurate rate with 13.49% and 7.32%, respectively, in 2013 and 2014, from 341 and 355 reported cases from sub-provincial levels in Jiangsu province. Most of the 523 malaria cases reported in Nantong Prefecture from 2000 to 2014 involved patients who first visited county CDCs seeking treatment, however, none of these cases received confirmed diagnosis of malaria in townships or villages.The staff at county CDCs and hospitals with a higher education background performed better at making and interpreting blood smears than staff from townships. Conclusions The network for malaria elimination in an entire province has been well established. However, an insufficient capacity for malaria diagnosis was observed, especially the preparing and reading the blood smears at the township and village levels, which is a challenge to achieving and maintaining malaria elimination

Metal-organic framework-derived single-atom catalysts for electrocatalytic energy conversion applications

Single-atom catalysts (SACs) derived from metal-organic frameworks (MOFs) are revolutionizing electrocatalytic energy conversion. This review explores their synthesis, characterization, and application, emphasizing their role in advancing sustainable energy technologies. SACs offer unprecedented efficiency and selectivity by dispersing individual metal atoms on a support material. This maximizes active site utilization and minimizes material usage compared to traditional catalysts. Various synthesis strategies, such as bimetallic MOF pyrolysis and ligand-coordinated anchoring, enable precise control over SACs properties. Characterization techniques like electron microscopy and spectroscopy reveal SACs structures and properties. Electron microscopy visualizes SACs morphology, while spectroscopy provides insights into metal atom coordination. In practical applications, MOF-supported SACs excel in proton-exchange membrane fuel cells (PEMFCs), direct formic acid fuel cells (DFAFCs), and Zn-air batteries (ZABs). They catalyze essential reactions, such as oxygen reduction and hydrogen oxidation, enhancing PEMFC efficiency and durability. In ZABs, SACs improve oxygen reduction and evolution reactions, boosting battery performance and stability. This review underscores the potential of MOF-derived SACs in sustainable energy conversion. By detailing synthesis, characterization, and applications, it contributes to the development of efficient catalysts for renewable energy technologies

UAV- and Machine Learning-Based Retrieval of Wheat SPAD Values at the Overwintering Stage for Variety Screening

In recent years, the delay in sowing has become a major obstacle to high wheat yield in Jiangsu Province, one of the major wheat producing areas in China; hence, it is necessary to screen wheat varieties are resilient for late sowing. This study aimed to provide an effective, fast, and non-destructive monitoring method of soil plant analysis development (SPAD) values, which can represent leaf chlorophyll contents, for late-sown winter wheat variety screening. This study acquired multispectral images using an unmanned aerial vehicle (UAV) at the overwintering stage of winter wheat growth, and further processed these images to extract reflectance of five single spectral bands and calculated 26 spectral vegetation indices. Based on these 31 variables, this study combined three variable selection methods (i.e., recursive feature elimination (RFE), random forest (RF), and Pearson correlation coefficient (r)) with four machine learning algorithms (i.e., random forest regression (RFR), linear kernel-based support vector regression (SVR), radial basis function (RBF) kernel-based SVR, and sigmoid kernel-based SVR), resulted in seven SVR models (i.e., RFE-SVR_linear, RF-SVR_linear, RF-SVR_RBF, RF-SVR_sigmoid, r-SVR_linear, r-SVR_RBF, and r-SVR_sigmoid) and three RFR models (i.e., RFE-RFR, RF-RFR, and r-RFR). The performances of the 10 machine learning models were evaluated and compared with each other according to the achieved coefficient of determination (R2), residual prediction deviation (RPD), root mean square error (RMSE), and relative RMSE (RRMSE) in SPAD estimation. Of the 10 models, the best one was the RF-SVR_sigmoid model, which was the combination of the RF variable selection method and the sigmoid kernel-based SVR algorithm. It achieved high accuracy in estimating SPAD values of the wheat canopy (R2 = 0.754, RPD = 2.017, RMSE = 1.716 and RRMSE = 4.504%). The newly developed UAV- and machine learning-based model provided a promising and real time method to monitor chlorophyll contents at the overwintering stage, which can benefit late-sown winter wheat variety screening