Search

Monitoring methods for beta-lactam (β-lactam) antibiotics, especially for ampicillin (AMP), with simple operation and sensitivity for realtime applications are highly required. To address this need, antioxidant carbon dots (E-CDs) with excellent fluorescence properties were synthesized using citric acid and ethylenediamine as raw materials. With a quantum yield of 81.97%, E-CDs exhibited a specific and sensitive response to ˙OH. The quenched fluorescence of E-CDs by the formed ˙OH could be restored through a competition reaction with AMP. Leveraging the signal-quenching strategy of E-CDs, H2O2, and Fe2+, a fluorescence signal-on strategy was developed using AMP as the fluorescence recovery agent for the sensitive detection of AMP. The mechanism of the quenching of E-CDs by ˙OH was attributed to the damaging effect of ˙OH on E-CDs. Under optimal conditions, the detection limit of this method for AMP was determined to be 0.38 μg mL−1. This method was successful in drug quality control and the spiked detection of AMP in lake water, milk, and sea cucumber, presenting a viable option for convenient and rapid antibiotic monitoring methods. [ABSTRACT FROM AUTHOR]

A kind of full-function two-sided optical bench interferometer (OBI) is designed to meet the practical requirements of the Taiji Program for space gravitational wave detection. The main optical paths are arranged on the A-side for transmission and interference, and other optical paths and electronic devices are placed on the B-side. According to the design scheme, we successfully constructed two OBIs by using hydrogen–oxygen catalytic stress-free bonding technology. When the OBI is installed and adjusted, the position and Angle error of the interference beam are controlled within 30 μm and 50 μrad through the self-designed precision mechanical clamping mechanism and beam position measuring device. The built OBI was placed on the vibration isolation platform in the vacuum tank for the stability test. The test results show that the noise of the OBI is less than 10 p m / √ H z in the frequency band of 0.1 Hz to 1 Hz, which meets the noise budget requirements of the Taiji Pathfinder in the middle- and high-frequency band. [ABSTRACT FROM AUTHOR]

Space-borne gravitational wave detection imposes a demanding requirement on the sensitivity of the laser interferometer. Among all disturbances that affect the measurement accuracy of the laser interferometer, temperature fluctuations contribute significantly. In this paper, the structure model and the interference path design of Taiji-1 laser interferometer have been used to conduct a preliminary simulation analysis of the temperature fluctuation noise through the finite element method. The temperature, the displacement and the optical path difference fluctuations have been obtained and theoretically analyzed. The preliminary simulation results are consistent with the theoretical analysis, which shows that the thermal–structural–optical simulation scheme adopted in this paper is reasonable. With the preliminary simulation results and the actual temperature control of Taiji-1 laser interferometer, we estimate that in Taiji-1 laser interferometer system, the temperature fluctuation is below the order of mK, the node displacement is within 1 0 0 pm, and the interference arm length difference fluctuation amplitude of the laser interferometer is also within 1 0 0 pm. [ABSTRACT FROM AUTHOR]

Analysis of mecA gene in Staphylococcus aureus (S. aureus) is essential for controlling infections in intensive care units (ICU) and preventing the use of ineffectual empirical treatments. However, quantitative determination of the mecA gene remains difficult. Herein, we propose a simple and sensitive colorimetric approach by integrating exonuclease-III (Exo-III) assisted signal cascade and G-quadruplex/hemin DNAzymes (G4 DNAzymes) catalyzed 2,2′-azino-bis (3-ethylben-zothiazoline-6-sulfonic acid) (ABTS) based color reaction. In this method, signal amplification does not necessitate the use of complex experimental components, such as multiple enzymes and primer design, while still maintaining a high signal amplifying efficiency. Therefore, the method has a broad mecA gene detection range from 10 fM to 1 nM and a low limit of detection down to 3.4 fM level. Taking the merit of simplicity and high sensitivity, the approach is promising in analyzing mecA gene in S. aureus and diagnosing infections. [Display omitted] • Analysis of mecA gene in Staphylococcus aureus (S. aureus) is essential for controlling infections. • We propose a simple and sensitive colorimetric approach by integrating exonuclease-III assisted signal cascade and G-quadruplex/hemin based color reaction. • The method does not require complicated experimental components (e.g. enzymes and primer design) and preparation for signal amplification. [ABSTRACT FROM AUTHOR]

Antioxidant carbon dots (ACDs) with high quantum yield were designed for the effective detection of bleomycin (BLM) with the presence of ferrous ions (Fe2+) ascribed to the specific fluorescence response of ACDs to hydroxyl radical (OH). [Display omitted] • Antioxidant carbon dots (ACDs) with high quantum yield were prepared. • ACDs exhibit enhanced fluorescence ability with the surface rich in amino, hydroxyl and carboxyl groups. • ACDs have selective and sensitive fluorescence response to ·OH through dynamic quenching effect. • The interaction of bleomycin and Fe2+ with the generation of ·OH was applied to detect bleomycin using ACDs as probe. In this work, antioxidant carbon dots (ACDs) with high quantum yield (63.98%) were developed through a one-step strategy using citric acid, ethylenediamine, and L-arginine as sources. The ACDs demonstrated excellent in vitro antioxidant activity. Additionally, ACDs displayed a unique fluorescence response to hydroxyl radical (OH). Leveraging this distinctive feature, a selective and sensitive fluorescence-based sensor was developed for detecting bleomycin (BLM) in the presence of ferrous ions (Fe2+). The studies on the oxidizing properties and dynamic quenching mechanism of ACDs by OH suggested that OH reduced the contents of the amino and hydroxyl groups of ACDs, leading to a decreased electron cloud density of ACDs for dynamic quenching of ACDs. Under optimally refined conditions, the detection limit of this strategy for BLM was 0.58 μg/mL, with a linear range spanning from 1 to 24 μg/mL when employing ACDs as the probe. This fluorescence sensing strategy provides a promising method for the detection of BLM in clinical samples. [ABSTRACT FROM AUTHOR]

The occurrence of extensional-related A-type granites with a high-K nature in some early Precambrian blocks hints a possible link with the orogeny, and may imply the ending of the orogenic processes and the beginning of craton stabilization. The newly recognized late Paleoproterozoic A-type granite, the Guijiayu pluton composed of monzogranites in the Xiaoqinling area of the southern margin of the North China Craton (NCC), is a promising locus to investigate the late Paleoproterozoic tectonic evolution of the NCC. LA-ICP-MS zircon U–Pb dating shows that the Guijiayu pluton was emplaced at ∼1.80 Ga. Petrologically, the Guijiayu granites contain perthite, annite and calcic amphibole but are lack of alkali mafic minerals. Geochemically, all the rocks are enriched in silicon and total alkali, and depleted in MgO, CaO and P 2 O 5 , with high FeOt/MgO, TiO 2 /MgO and 10,000 Ga/Al ratios and high HFSEs (i.e., Zr, Nb, Ce, Y) concentrations, as well as negative Eu, Sr, P and Ti anomalies. They are also characterized by high melting temperatures and metaluminous to weakly peraluminous natures. Taken together, the Guijiayu granites show an affinity to aluminous A-type granite. Their geochemical characteristics (e.g., obviously negative Eu and Sr anomalies), along with the low zircon ε Hf ( t ) values (−13.9 to −7.0) and whole-rock ε Nd ( t ) values (−5.81 to −5.65), indicate that the Guijiayu aluminous A-type granite was derived from partial melting of the crustal calc-alkaline granitoids dominated by the granodiorite of the Taihua Group in the study area. Combined with the regional data, especially for the identification of the clockwise P–T paths of Paleoproterozoic metamorphism in the southern margin of the NCC, even coeval granites and regional retrograde metamorphism in other areas in the NCC, it is most likely that the peak of continent–continent collision had finished in the study area at least before ∼1.80 Ga, and that the generation of the Guijiayu aluminous A-type granite was related to the underplating of mafic magmas in a post-collisional regime. [ABSTRACT FROM AUTHOR]

A-type granites are a spectrum of especial felsic rocks that are produced commonly within an extensional environment. They are rare before middle Paleoproterozoic but present abundantly since the late Paleoproterozoic, probably indicating a causal change of tectonics and geodynamic mechanism in the continental evolution of the Earth. An early Mesoproterozoic A-type granite belt was recognized in the southern margin of the North China Craton (NCC) in recent decades. The occurrence of this type of rocks indicates a possible spatial–temporal link between the tectonic evolution of the NCC and the breakup of the Columbia supercontinent during the Mesoproterozoic. The Zhangjiaping granitic pluton is located in the southern margin of the NCC and one part of the A-type granite belt. It can be divided into three zones according to their textural and compositional differences of the rocks with a gradually increasing degree of evolution inwards: wall zone, intermediate zone and core zone. LA-ICP-MS zircon U–Pb dating shows that it was emplaced at ca. 1.53 Ga. Petrologically, the Zhangjiaping granites contain perthite and calcic amphibole but are lack of alkali mafic minerals. Geochemically, all the Zhangjiaping granitic rocks show an affinity to fractionated aluminous A-type granites, with enrichment in silicon and total alkali, and depletion in MgO, CaO and P 2 O 5 with negative Eu, Sr and Ti anomalies, as well as high FeOt/MgO, TiO 2 /MgO and Ga/Al ratios and high HFSEs (i.e., Zr, Nb, Ce, Y) concentrations. Such signatures, along with their low ε Hf ( t ) values (−12.5 to −4.0) of all the granites from the Zhangjiaping pluton, obviously indicate that the Zhangjiaping aluminous A-type granites were derived from partial melting of the crustal calc-alkaline granitoids (i.e., the granodiorites of the Taihua Complex in the study area) and experienced fractional crystallization during magmatic evolution. Their generation would be related to the underplating of mafic magmas in an extensional regime. Integrated with regional data, the Zhangjiaping aluminous A-type granites were the products of anorogenic magmatism likely corresponding to the breakup of the Columbia supercontinent. [ABSTRACT FROM AUTHOR]

Overproduction of reactive oxygen species (ROS), elevated synovial inflammation, synovial hyperplasia and fibrosis are the main characteristic of microenvironment in rheumatoid arthritis (RA). Macrophages and fibroblast-like synoviocytes (FLSs) play crucial roles in the progression of RA. Hence, synergistic combination of ROS scavenging, macrophage polarization from pro-inflammatory M1 phenotype towards M2 anti-inflammatory phenotype, and restoring homeostasis of FLSs will provide a promising therapeutic strategy for RA. In this study, we successfully synthesized metformin-derived carbon dots (MCDs), and investigated the antirheumatic effect in vivo and in vitro. Designed MCDs could target inflamed cells and accumulate at the inflammatory joints of collagen-induced arthritis (CIA) rats. In vivo therapeutic investigation suggested that MCDs reduced synovial inflammation and hyperplasia, ultimately prevented cartilage destruction, bone erosion, and synovial fibrosis in CIA rats. In addition, MCDs eliminated the cellular ROS in M1 phenotype macrophages in RA microenvironment through the enzyme-like catalytic activity as well as inhibiting NOD-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome signaling pathway, effectively polarizing them into the M2 phenotype to realize the anti-inflammatory effect. Furthermore, MCDs could inhibit the proliferation, migration, and fibrosis of inflamed FLSs. Mechanistically, MCDs restored the homeostasis of FLSs while reducing the level of synovial inflammation by blocking IL-6/gp130 signaling pathway. Combined with preferable biocompatibility, MCDs offer a prospective treatment approach for RA. [ABSTRACT FROM AUTHOR]

• A suite of ~1.6 Ga low-δ18O A-type granites was identified on the southern margin North China Craton. • The 18O-depletion A-type granites were derived from the remelting of preexisting hydrothermally altered basement rocks (i.e., Taihua Complex). • The formation of a low-δ18O source rocks and ~1.6 Ga A-type granites were related to the late Paleoproterozoic rifting. • The rifting might continue at least till ~1.6 Ga. A-type granites with 18O-depletion signatures are rather enigmatic as regards not only their typology and petrogenesis but also their rock-forming geodynamic mechanism. Here we report a suite of late Paleoproterozoic low-δ18O A-type granites from the Longwangzhuang pluton on the southern margin of the North China Craton. SIMS zircon U-Pb dating showed that the Longwangzhuang pluton was emplaced at 1613 ± 4 Ma. Combined with previous data, it is clear that the mineral components of Longwangzhuang granites are variable and consist of perthite, quartz, plagioclase, biotite and amphibole (calcic hastingsite, ferroedenite, and sodic ferrogedrite). Geochemically, they are metaluminous to peraluminous and have high alkali contents (K 2 O + Na 2 O > 8.76 wt%, K 2 O/Na 2 O > 1), FeOt/(FeOt + MgO) (>0.95) ratios, Zr + Nb + Ce + Y (>993 ppm) contents, and 10000 Ga/Al (>4.31) ratios, resembling A-type granites. In-situ oxygen isotope analysis displayed low zircon δ18O values between 4.0‰ and 4.9‰ with a weighted average of 4.4‰. Based on the Archean two-stage zircon Hf and whole-rock Nd model ages coupled with the low (La/Yb) CN ratios, negative anomalies of Eu and Sr, and high Zr saturation temperatures, and the presence of low pressures (3.3–5.7 kbar) amphiboles, the Longwangzhuang A-type granites were generated by "self-cannibalizing" pre-existing low-δ18O old rocks (i.e., the Taihua Complex) and emplaced at shallow depth. Combined with regional geological observations (i.e., coeval tuffites), a passive rift setting was the most plausible explanation for the generation of the late Paleoproterozoic low δ18O A-type granites on the southern margin of the North China Craton. Such a rifting could likely have lasted at least till 1.6 Ga. [ABSTRACT FROM AUTHOR]

The establishment of a convenient and effective detection method for doxycycline (DC) holds significant importance in drug monitoring and drug residue assessment. In this work, carbon quantum dots (CQDs) with excellent and stable luminescence performance (the quantum yield of CQDs was 21.8%) were synthesized by the melting method and employed as probes to monitor the fluorescence intensity variations before and after the introduction of DC. A fluorescence analytical method based on the internal filtration effect (IFE) was developed for DC determination. The mechanism of DC quenching CQDs was verified using fluorescence lifetime tests, absorption spectroscopy, and evaluation of internal filtration parameters. After optimizing experimental conditions, it was found that the DC concentration (CDC) exhibited a good linear relationship with the fluorescence quenching efficiency ((F0-F)/F0) of CQDs in the range of 5–30 µM. The fitted linear equation was Y = 0.01249*CDC+0.03625, R2 = 0.9987, and the detection limit was 2.343 µM (n = 8). This developed method has been successfully applied to accurately determine DC concentrations in both doxycycline hydrochloride tablets and human serum samples. It stands out for its simplicity, rapidity, and acceptable detection performance. Due to its advantages, this method holds great promise for application in the biomedical field for monitoring DC drug concentrations and ensuring quality control. [ABSTRACT FROM AUTHOR]

The development of nanomedicine for the treatment of infection caused by resistant bacteria, especially Gram-negative bacteria, is still in the bottleneck. The long-term antibacterial activity and the low induced resistance risk need improvement. Herein, guanidinium-based carbon dots (G-CDs) were prepared from citric acid, dimethyldiallylammonium chloride, and polyhexamethyleneguanidine through melting strategy. The antibacterial properties of G-CDs against Gram-negative and resistant bacteria were investigated. G-CDs exhibit strong and long-term antibacterial activity, as well as antibiofilm activity, with less potential for inducing bacterial resistance. The antibacterial mechanism of G-CDs of the adsorption action and killing effect was elucidated, which was different from the mechanism of antibiotics. Moreover, derived from the interacting mode of nanomaterials and ssDNA, the enhanced ability of G-CDs against Gram-negative bacteria was studied based on the found interaction of G-CDs and lipopolysaccharide (LPS) for the understanding of the mode for the absorption of G-CDs on the cell wall of Gram-negative bacteria. The multimode interactions of van der Waals force, electrostatic adsorption and hydrogen bonding were clarified. Furthermore, G-CDs had excellent in vivo safety and in vivo therapeutic effects in E. coli -infected pneumonia through an intravenous approach. This study provides a hopeful strategy for developing antibacterial drugs from understanding the interacting mode of the drug and the cell wall of bacteria. Guanidine-based carbon dots (G-CDs), with long-term antibacterial activity against Gram-negative bacteria and the inhibition of resistance development, exhibited the high in vivo efficacy to E. coli-infected pneumonia and the promising antibacterial agents for the treatment of clinically relevant pathogenic bacteria. [Display omitted] [ABSTRACT FROM AUTHOR]

Four Gram-staining-negative, aerobic, yellow-pigmented and rod-shaped bacteria, named strains BD1B2-1T, NT2B1T, YF14B1 and DM2B3-1, were isolated from four rhizosphere soil samples of banana in China. Comparison of the 16S rRNA gene sequences showed that all these strains were most closely related to an invalidly published species, ‘Rhodocytophaga rosea’ 172606-1, with similarities ranging from 87.7 to 88.0%. According to the phylogenomic analysis, the four strains were clustered in an independent lineage and closely related to the genus Rhodocytophaga. The genomic sizes of these strains were approximately 9.49–9.77 Mbp with the DNA G + C contents of 38.8–39.0 mol%. They all contained C16:1ω5c, iso-C15:0 and iso-C17:0 3-OH as the major fatty acids and menaquinone 7 as the only respiratory quinone. They all had phosphatidylethanolamine as the major polar lipids. Based on phenotypic and phylogenomic characteristics, the four strains should represent two novel species within a novel genus, for which the names Xanthocytophaga agilis gen. nov., sp. nov. (BD1B2-1T = GDMCC 1.2890T = JCM 35374T) and Xanthocytophaga flavus sp. nov. (NT2B1T = GDMCC 1.2889T = JCM 35375T) are proposed; the former is assigned as the type species of the novel genus Xanthocytophaga gen. nov. In addition, based on the phenotypic and phylogenomic data, we proposed to reclassify the existing genus Rhodocytophaga in the family Cytophagaceae into a novel family Rhodocytophagaceae fam. nov. The novel family consists of the type genus Rhodocytophaga and the novel genus Xanthocytophaga. [ABSTRACT FROM AUTHOR]

A Gram-staining-negative, aerobic, and rod-shaped with tapered end myxobacterium, designed as strain H56D21T, was isolated from forest soil sampled from the Diaoluo Mountain National Nature Reserve located in Hainan Province, PR China. It showed prey ability on two kinds of phytopathogens including both fungi (Fusarium solani, Fusarium graminearum, and Fusarium oxysporum) and bacteria (Ralstonia solanacearum and Xanthomonas campestris). Phylogenetic analyses based on the 16S rRNA gene and core genes sequences revealed that strain H56D21T belonged to the genus Hyalangium and was most closely related to Cystobacter gracilis DSM 14753 T and Hyalangium minutum DSM 14724 T. Genome comparison showed 85.6% and 82.3% of average nucleotide identity between strain H56D21T and the above two type strains and 29.8% and 25.1% of digital DNA-DNA hybridization , respectively. The novel strain had a large genome size of 13.56 Mbp and a high DNA G + C content of 67.1%. Genome annotation identified 46 secondary metabolite biosynthesis gene clusters and 187 CAZymes-encoding genes. The major fatty acids contained iso-C15:0, iso-C15:0 DMA, C16:1ω5c, and iso-C17:0. The dominant respiratory quinone was menaquinone 8. Based on the phenotypic, chemotaxonomic and phylogenetic analyses, we suggested that strain H56D21T should represent a novel species of the genus Hyalangium with a proposed name of Hyalangium versicolor sp. nov. (type strain H56D21T = GDMCC 1.1944 T = KCTC 82613 T) and Cystobacter gracilis should be reclassified as Hyalangium gracile comb. nov. [ABSTRACT FROM AUTHOR]

The establishment of a convenient and efficient testing method is crucial and needed for the monitoring of diosmin. In this study, nitrogen doped carbon dots (N-CDs) with the particle size distribution of 2.5–5.7 nm and the average diameter of 4.1 nm were successfully synthesized using a simple strategy. N-CDs exhibited excellent and stable fluorescence performance with the quantum yield of 22.33%. Correspondingly, a fluorescence analytical method was developed for diosmin determination using N-CDs as probe. UV-vis absorbance spectroscopy and the evaluation of internal filtering parameters verified that the mechanism causing the quenching of N-CDs was an internal filtering effect (IFE). The concentration of diosmin can be directly evaluated based on the quenched fluorescence intensities. After optimizing experimental conditions, it was found that the fluorescence quenching efficiency ((F0-F)/F0) of N-CDs exhibited a good linear relationship with the concentration of diosmin (CDiosmin) in the range of 3.0–50 µg/mL. The limit of detection (LOD) was 0.86 µg/mL based on 3σ/slope (n = 13). This method was successfully applied to accurately determine the content of diosmin in diosmin tablets and human plasma samples with good reproducibility. It stands out for its simplicity, speed, and acceptable determination performance. [ABSTRACT FROM AUTHOR]

[Display omitted] • Heulandite–high-temperature activated sodium zirconium phosphate (HEU–HTA-Na-ZrP) was synthesised for the first time for Th(IV) batch adsorption. • The HEU–HTA-Na-ZrP pellets (HEU–HTA-Na-ZrP-P) were prepared for dynamic adsorption. • HEU–HTA-Na-ZrP showed excellent Th(IV) adsorption capacity and reusability. • The mechanisms of Th(IV) adsorption on HEU–HTA-Na-ZrP were discussed. • HEU–HTA-Na-ZrP-P could separate Th(IV) from simulated and real nuclear wastewater. Herein, heulandite–high-temperature activated sodium zirconium phosphate (HEU–HTA-Na-ZrP) composites were first synthesised for adsorbing tetravalent thorium (Th(IV)) from aqueous solution. Furthermore, the HEU–HTA-Na-ZrP pellets (HEU–HTA-Na-ZrP-P) were fabricated for dynamic adsorption. Compared to Na-ZrP, the BET surface area of HEU–HTA-Na-ZrP increased of ∼ 189 m2⋅g−1. In batch adsorption, Th(IV) adsorption increased with increasing pH, C 0 values (initial concentrations) and temperature. The equilibrium Th(IV) adsorption capacities were 314.17 ± 11.27 mg⋅g−1 and 358.89 ± 3.47 mg⋅g−1 for Na-ZrP and HEU–HTA-Na-ZrP, respectively. Thermodynamics, isotherms and kinetics suggested an endothermic, spontaneous, homogeneous and chemisorption process. Characterization verified the adsorption capacities of Th(IV), and the main possible Th(IV) adsorption mechanisms were associated with ion exchange and –OH, Zr–O coordination. Notably, the reusability study indicated that the samples treated with 0.1 mol⋅L−1 H 3 PO 4 solution exhibited excellent reusability. Dynamic adsorption results indicated the structural stability of the composite pellets. 50% Th(IV) breakthrough time (τ (min)) increased with increasing mass and then decreased, and τ (min) decreased with increasing pH. Both Thomas and Yoon–Nelson models could better describe the Th(IV) dynamic adsorption behaviour. Moreover, HEU–HTA-Na-ZrP-P could separate Th(IV) from simulated and real nuclear wastewater. This work demonstrates that HEU–HTA-Na-ZrP can be applied as an efficient adsorbent for the removal of Th(IV) from Th-containing solutions. [ABSTRACT FROM AUTHOR]

Two Gram-staining-negative, aerobic and rod-shaped strains, designated c23x22T and sex2T, were isolated from forest soil collected from Chebaling National Nature Reserve in Guangdong Province and Limu Mountain National Forest Park in Hainan Province, P. R. China, respectively. Phylogenetic analyses based on 16S rRNA gene sequences revealed that they belonged to the genus Microvirga, and strain c23 x22T was most closely related to ‘Microvirga alba’ KCTC 72385, while strain sex2T showed close relationship with Microvirga guangxiensis CGMCC 1.7666T. The average nucleotide identity and digital DNA–DNA hybridization values between strains c23 x22T and sex2T and their close relatives, ‘M. alba’ KCTC 72385 and M. guangxiensis CGMCC 1.7666T, were all below the threshold values for species delimitation. The predominant quinones of the two novel strains were ubiquinone 10, and the major fatty acids contained C19:0 cyclo ω8c and summed feature 8 (C18:1ω7c and/or C18:1ω6c). Their predominant polar lipids were phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylcholine. The phenotypic, genotypic and chemotaxonomic analyses clearly supported that strains c23 x 22T and sex2T represent two novel species of the genus Microvirga, for which the name Microvirga terricola sp. nov. (type strain c23 x 22T = GDMCC 1.1700T = KCTC 62432T) and Microvirga solisilvae sp. nov. (type strain sex2T = GDMCC 1.1651T = KACC 21311T) are proposed, respectively. [ABSTRACT FROM AUTHOR]

An orange-pigmented myxobacterium, designated strain c25j21T, was isolated from subtropical forest soil collected from the Chebaling National Nature Reserve in Guangdong Province, China. Phylogenetic analysis based on the 16S rRNA gene and core genes clearly showed that the novel strain was affiliated within the genus Corallococcus and most closely related to Corallococcus aberystwythensis DSM 108846T (99.3% 16S rRNA gene sequence similarity), while C. exercitus DSM 108849T (99.2%) and C. carmarthensis DSM 108842T (99.0%) were the next most closely related type strains. The draft genome sequence of strain c25j21T was 9.23 Mb in length with a G + C content of 70.7 mol%. The average nucleotide identity (ANI) and digital DNA–DNA hybridization (dDDH) values between strain c25j21T and its closely related type strains were 88.1–89.1 and 34.1–36.3%, respectively. The major fatty acids contained iso-C15:0, iso-C17:0, iso-C17:1ω5c and iso-C17:0 2-OH. The predominant respiratory quinone was menaquinone 7. Based on phylogenetic, phenotypic and chemotaxonomic analysis, strain c25j21T represents a novel species of the genus Corallococcus, for which the name Corallococcus silvisoli sp. nov. is proposed. The type strain is c25j21T (= GDMCC 1.1387T = KCTC 62437T). [ABSTRACT FROM AUTHOR]

Epidemiological and clinical characteristics of patients with COVID-19 have been reported in the last two years. A few studies reported clinical course of illness of median 22 days, including viral shedding of median 20 days, but there are several cases with a longer time of viral shedding. In this study, we included four cases with a longer illness course of more than 40 days who had been discharged or still in hospital by March 15, 2020. Demographic, clinical treatment, and laboratory data, including serial samples for viral RNA detection, were extracted from electronic medical records. We described the epidemiological and clinical characteristics and the course of viral shedding. Two patients had comorbidity, one with hypertension and the other with diabetes. We found smoking was not an independent risk factor. D-dimer maybe related to the severity of illness but not to the course of the illness. Nucleic acid detection suggested that maybe more sampling sites represented more virus replication sites and longer course of illness. In this study we found some non-critical severe relatively young patients whose character was different from former studies described to provide a basis for reference to assess the risk of transmission and the isolation duration of patients. [ABSTRACT FROM AUTHOR]

This document is a retraction note for an article titled "HOXD9 promotes epithelial-mesenchymal transition and cancer metastasis by ZEB1 regulation in hepatocellular carcinoma." The article has been retracted by the Editor-in-Chief at the request of the corresponding author due to concerns about the similarity of the data presented to other publications. The corresponding author has stated that the experiments were performed by a third party and there may have been mismanagement of the data. The retraction has been agreed upon by Lei Dong, but the other authors have not responded to the publisher's correspondence. Springer Nature, the publisher, remains neutral in regards to jurisdictional claims and institutional affiliations. [Extracted from the article]

This document is a retraction note for an article titled "HOXD9 promotes epithelial-mesenchymal transition and cancer metastasis by ZEB1 regulation in hepatocellular carcinoma." The article has been retracted by the Editor-in-Chief at the request of the corresponding author due to concerns about the similarity of the data presented to other publications. The corresponding author has stated that the experiments were performed by a third party and there may have been mismanagement of the data. The retraction has been agreed upon by Lei Dong, but the other authors have not responded to the publisher's correspondence. Springer Nature, the publisher, remains neutral in regards to jurisdictional claims and institutional affiliations. [Extracted from the article]

Taiji-1 is the first technology demonstration satellite of the Taiji Program in Space, which, served as the pre-PathFinder mission, had finished its nominal science operational phase and successfully accomplished the mission goal. The gravitational reference sensor (GRS) on-board Taiji-1 is one of the key science payloads that coupled strongly to other instruments, sub-systems and also the satellite platform itself. Fluctuations of the physical environment inside the satellite and mechanical disturbances of the platform generate important noises in the GRS measurements, therefore their science data can also be used to evaluate the performance of the μ N -thrusters and the stability of the platform. In this work, we report on the methods employed in Taiji-1 GRS data processing in the systematical modelings of the spacecraft orbit and attitude perturbations, mechanical disturbances, and internal environment changes. The modeled noises are then removed carefully from the GRS science data to improve the data quality and the GRS in-orbit performance estimations. [ABSTRACT FROM AUTHOR]

Diabetic mellitus management extends beyond blood glucose monitoring to the essential task of mitigating the overexpression of reactive oxygen species (ROS), particularly vital for cellular repair, especially within the nervous system. Herein, antioxidant carbon dots (Arg-CDs) were designed and prepared using anhydrous citric acid, L-arginine, and ethylenediamine as sources through a hydrothermal method. Arg-CDs exhibited excellent scavenging ability to 2,2-Diphenyl-1-picrylhydrazyl (DPPH∙), and fluorescence response to hydroxyl radicals (∙OH), a characteristic representative of reactive oxygen species (ROS). Assisted by glucose oxidase and Fe2+, Arg-CDs showed a sensitive and selective response to glucose. The quenching mechanism of Arg-CDs by formed ∙OH was based on the static quenching effect (SQE). The analytical performance of this method for glucose detection encompassed a wide linear range (0.3–15 μM), a low practical limit of detection (0.1 μM) and practical applicability for blood glucose monitoring. In an in vitro model employing glial cells (BV2 cells), it was observed that high glucose medium led to notable cellular damage ascribed to the excessive ROS production from hyperglycemia. The diminished and apoptotic glial cells were gradually recovered by adding increased contents of Arg-CDs. This work illustrates a promising area that designs effective carbon dots with antioxidant capacity for the dual applications of detection and cell repairing based on the utilization of antioxidant activity. [ABSTRACT FROM AUTHOR]

Insufficient angiogenesis, a prominent characteristic of diabetic mellitus, significantly affected the reparative capacity of orthopedic diseases. Imbalanced redox caused by excessive reactive oxygen species is one of the crucial factors in weakening vascularization. Conditions such as implant osseointegration failure and delayed wound healing in orthopedic diseases are significantly influenced by the vascularization deficits in diabetic mellitus. Promoting angiogenesis by modulating endothelial function is considered as an effective therapy for diabetes, yet current efforts remain insufficient. Nanocatalytic medicine has emerged as promising candidates for therapy. Herein, carbon dots (CDs) with preferable catalytic effect by mimicking both superoxide dismutase (SOD) and catalase (CAT)-like activity were designed and synthesized using anhydrous citric acid and ethane diamine. CDs effectively scavenged superoxide anion (O 2 •−) and hydrogen peroxide (H 2 O 2) with excellent biocompatibility. Meanwhile, CDs promoted the proliferation, migration, and angiogenesis capacity of human umbilical vein endothelial cells with enhanced SOD and CAT activity in simulated oxidative stress of diabetes. Notably, CDs promoted vascularization by activate PI3K-AKT signaling pathway in impaired endothelial cells, which was demonstrated through transcriptome sequencing, western blot, and reverse transcription-polymerase chain reaction. The therapeutic effect of CDs based on promoting vascularization was found in orthopedic disease models of subcutaneous implant and wound healing of diabetic rat. These findings highlight a promising clinical application for CDs as a nanocatalytic medicine in enhancing vascularization for diabetic mellitus. Carbon dots prepared from controllably hydrothermal strategy, acting as nanocatalytic medicine, exhibit both SOD-like and CAT-like activities for promoting angiogenesis with clarified molecular mechanism to effectively intervene diabetes-associated orthopedic diseases. [Display omitted] [ABSTRACT FROM AUTHOR]

Although widespread ca. 2.2–2.1 Ga igneous activities were identified through the North China Craton (NCC), their petrogenesis and implications for the Paleoproterozoic tectonic regime of the NCC are still under hot debate. Here we present the 2.18–2.14 Ga gabbro-diorite plutons in the Xiong'ershan Taihua Complex, southern North China Craton. They are dominantly gabbros with minor as gabbroic-dioritic rocks. The samples exhibit transitional geochemical characteristics from tholeiitic to calc-alkali series with enrichment in LREEs (e.g., La/Yb N = 1.90–13.9) and LILEs (e.g., Rb, Ba and Sr) but depletion in HFSE (e.g., Nb, Ta and Ti), corresponding to affinity of arc-related magmatism. The high Fe 2 O 3 (8.90–14.91 wt%), CaO (6.78–9.81 wt%) contents, and Ti/Y ratios (179–635), low Th concentrations (0.11–4.08 ppm), and consistent La/Nb and Th/Nb ratios, preclude significant crustal contamination during magma emplacement. The samples show negative zircon ε Hf (t) (−7.3–−1.6) and whole-rock ε Nd (t) (−4.0–+0.9) values with much older model ages (T DM Hf = 2811–2606 Ma and T DM Nd = 3069–2711 Ma) than their formation ages, along with high La/Nb (1.69–6.21) and low La/Ba (0.01–0.05) ratios, indicating a refertilized Archean lithospheric mantle source. Considering that zircons of 2.18–2.14 Ga gabbro-diorite in the Xiong'ershan area lack metamict features and exhibit originally low but homogeneous δ18O values in the mantle source (3.04‰ to 5.07‰, 4.21‰ on average), we prefer they derived from preexisting 18O-depleted mantle source, which might be a highly heterogeneous metasomatized SCLM by subducted-fluid during the Archean cratonization. The consistent Sm/Yb and La/Sm ratios indicate ∼5–30% partial melting of the garnet-spinel dominant source region. Combing the low δ18O signature and within-plate (high Zr, Zr/Y, Th/Hf and Ta/Hf) geochemical features, we suggest a thermal anomaly linked to a rift setting could account for the mantle melting. The intraplate ca. 2.1 Ga low-δ18O magmatism possibly resembles those during the Neoproterozoic glaciations associated with major dispersal periods of Rodinia. To better understand the Paleoproterozoic tectonic evolution of the NCC, we have also comprehensively compiled all the published ages and geochemical data of the 2.2–2.1 Ga mafic-felsic igneous rocks. The mafic suites can be divided into two groups based on ages and geochemical affinities. Mafic rocks of Group 1 (2.19–2.12 Ga) belong to rift-related basalts, together with spatially associated 2.19–2.13 Ga A-type granitic rocks and volcano-sedimentary associations, likely indicating an intraplate rift setting. Whereas mafic rocks of Group 2 (2.15–2.06 Ga) show geochemical affinity of island arc calc-alkaline basalts, together with coeval 2.18–2.05 Ga I-S type granitic associations, implying an arc-related setting and recording a possible tectonic transition from extension to subduction-collision. The rifting events in the NCC during 2.2–2.1 Ga may coincide with the global lithospheric break-up of the supercontinent, and the subsequent tectonic transition could correspond to development of the globally orogenesis at 2.1–1.8 Ga. • The Paleoproterozoic low-δ18O gabbro-diorite plutons were formed at 2.18–2.14 Ga. • The mafic association was derived from an ancient metasomatized SCLM source. • They were formed in an intraplate rifting system. • The extensive 2.2–2.1 Ga magmatism in the NCC corresponds to global breakup event. [ABSTRACT FROM AUTHOR]

The late Paleoproterozoic A-type granitoids are important for constraining of the lithotectonic and geodynamic processed involved in the creation of continental crust. The newly identified late Paleoproterozoic felsic extrusive rocks from the southwestern margin of the North China Craton (NCC) consist of rhyolites which show melting corrosion structure, autoclastic texture and fiber structure of mineral grains and have weighted mean SIMS zircon U Pb ages of 1794.7 ± 3.6 Ma to 1780.3 ± 5.6 Ma. The rhyolite samples show high SiO 2 (67.59–74.38 wt%) and K 2 O + Na 2 O (3.68–11.10 wt%), and low MgO (0.05–1.17 wt%), CaO (0.19–2.58 wt%) and P 2 O 5 (0.08–0.16 wt%). They display aluminous A-type granite/rhyolite geochemical compositions, such as high A/CNK (0.78–1.23), FeOT/(FeOT + MgO) (0.81–0.99) and 10000Ga/Al (2.32–4.03) ratios, and high Zr + Nb + Ce + Y (824–1272 ppm) concentrations, as well as high zirconium saturation temperatures (T Zr = 873–964 °C). These signatures, along with their low ε Hf (t) (−3.6 to −1.5) and ε Nd (t) values (−4.31 to −3.31) and old two-stage Hf model ages (T DM C = 2.70–2.57 Ga), indicate that the rhyolites were derived from partial melting of the Neoarchean felsic basement rocks. These volcanic rocks also have low zircon δ18O values ranging from 1.5‰ to 6.8‰, which were inherited from the Neoarchean 18O-depleted basement rocks that underwent high-T hydrothermal alteration, rather than resulted from contamination or later high-T water/rock interaction. The rhyolite rocks in this study, the earliest igneous rocks in the southwestern NCC after the Paleoproterozoic consolidation of the crystalline basement, were formed in a rift setting, marking the initial breakup of the Guyuan Rift in the southwestern NCC. The rhyolite rocks in combination with the Xiong'er volcanic rocks in the southern NCC mark the initial rifting of the NCC (Xiong'er Rift and Guyuan Rift) after cratonization (~1.85–1.8 Ga). The youngest retrograde metamorphism (1.80–1.79 Ga) in the NCC indicates that the transition from post-orogenic to intracontinental rift setting occurred at ca. 1.79 Ga. • The Baijiagou, Shizuizi and Baojiashan rhyolites formed at ca. 1.79 Ga. • Melting of pre-existing low δ18O rock produce the 18O-depleted rhyolites. • The rhyolites mark the initial rift of the southwestern NCC. • Transition from post-orogenic to intracontinental rift in NCC was at ca. 1.79 Ga. [ABSTRACT FROM AUTHOR]

To explore the applicability of MuLBSTA Score in COVID-19 patients, a retrospective analysis was performed on 330 cases of COVID-19 patients in Southeast Hospital of Xiaogan City, Hubei Province. The clinical characteristics of COVID-19 patients were described and multilobe infiltrate in CT, bacterial infection, lymphocyte count, smoke in history, history of hypertension, and age distribution in the population of mild and severe patients were analyzed. All included patients were scored according to the MuLBSTA early warning scoring system and its efficacy in early warning of severe symptoms was analyzed. CT feature of infiltration changes on multiple lobes, the absolute value of lymphocyte count of less than 0.8 × 109, accompanied by bacterial infection, history of smoking, history of hypertension, and an age of greater than 60 years old were all statistically significant factors in patients with severe COVID-19. ROC curve analysis indicated that the sensitivity, specificity and accuracy of the early warning system were 0.651, 0.954 and 0.93, respectively. The MuLBSTA Score has a good early warning effect on severe COVID-19 patients. • This study explores the applicability of MuLBSTA Score in COVID-19 patients. • COVID-19 patients were scored according to the MuLBSTA early warning scoring system. • Infiltration changes on multiple lobes was statistically significant factors in COVID-19 patients. • Sensitivity, specificity and accuracy of the early warning system were 0.651, 0.954 and 0.93, respectively. [ABSTRACT FROM AUTHOR]