Zidovudine in synergistic combination with nitrofurantoin or omadacycline: in vitro and in murine urinary tract or lung infection evaluation against multidrug-resistant Klebsiella pneumoniae.

Limited treatment options and multidrug-resistant (MDR) Klebsiella pneumoniae present a significant therapeutic challenge, underscoring the need for novel approaches. Drug repurposing is a promising tool for augmenting the activity of many antibiotics. This study aimed to identify novel synergistic drug combinations against K. pneumoniae based on drug repurposing. We used the clinically isolated GN 172867 MDR strain of K. pneumoniae to determine the reversal resistance activity of zidovudine (AZT). The combined effects of AZT and various antibiotics, including nitrofurantoin (NIT) and omadacycline (OMC), were examined using the checkerboard method, growth curves, and crystal violet assays to assess biofilms. An in vitro combination activity testing was carried out in 12 isolates of K. pneumoniae. In vivo murine urinary tract and lung infection models were used to evaluate the therapeutic effects of AZT + NIT and AZT + OMC, respectively. The fractional inhibitory concentration index and growth curve demonstrated that AZT synergized with NIT or OMC against K. pneumoniae strains. In addition, AZT + NIT inhibited biofilm formation and cleared mature biofilms. In vivo, compared with untreated GN 172867-infected mice, AZT + NIT and AZT + OMC treatment decreased colony counts in multiple tissues (P < 0.05) and pathological scores in the bladder and kidneys (P < 0.05) and increased the survival rate by 60% (P < 0.05). This study evaluated the combination of AZT and antibiotics to treat drug-resistant K. pneumoniae infections and found novel drug combinations for the treatment of acute urinary tract infections. These findings suggest that AZT may exert significant anti-resistance activity.

Fabrication of levofloxacin-loaded porcine acellular dermal matrix hydrogel and functional assessment in urinary tract infection.

Bacterial cystitis, a commonly occurring urinary tract infection (UTI), is renowned for its extensive prevalence and tendency to recur. Despite the extensive utilization of levofloxacin as a conventional therapeutic approach for bacterial cystitis, its effectiveness is impeded by adverse toxic effects, drug resistance concerns, and its influence on the gut microbiota. This study introduces Lev@PADM, a hydrogel with antibacterial properties that demonstrates efficacy in the treatment of bacterial cystitis. Lev@PADM is produced by combining levofloxacin with decellularized porcine acellular dermal matrix hydrogel and exhibits remarkable biocompatibility. Lev@PADM demonstrates excellent stability as a hydrogel at body temperature, enabling direct administration to the site of infection through intravesical injection. This localized delivery route circumvents the systemic circulation of levofloxacin, resulting in a swift and substantial elevation of the antimicrobial agent's concentration specifically at the site of infection. The in vivo experimental findings provide evidence that Lev@PADM effectively prolongs the duration of levofloxacin's action, impedes the retention and invasion of E.coli in the urinary tract, diminishes the infiltration of innate immune cells into infected tissues, and simultaneously preserves the composition of the intestinal microbiota. These results indicate that, in comparison to the exclusive administration of levofloxacin, Lev@PADM offers notable benefits in terms of preserving the integrity of the bladder epithelial barrier and suppressing the recurrence of urinary tract infections.

Deterministic Magnetization Switching via Tunable Noncollinear Spin Configurations in Canted Magnets.

Spin obit torque (SOT) driven magnetization switching has been used widely for encoding consumption-efficient memory and logic. However, symmetry breaking under a magnetic field is required to realize the deterministic switching in synthetic antiferromagnets with perpendicular magnetic anisotropy (PMA), which limits their potential applications. Herein, we report all electric-controlled magnetization switching in the antiferromagnetic Co/Ir/Co trilayers with vertical magnetic imbalance. Besides, the switching polarity could be reversed by optimizing the Ir thickness. By using the polarized neutron reflection (PNR) measurements, the canted noncollinear spin configuration was observed in Co/Ir/Co trilayers, which results from the competition of magnetic inhomogeneity. In addition, the asymmetric domain walls demonstrated by micromagnetic simulations result from introducing imbalance magnetism, leading to the deterministic magnetization switching in Co/Ir/Co trilayers. Our findings highlight a promising route to electric-controlled magnetism via tunable spin configuration, improve our understanding of physical mechanisms, and significantly promote industrial applications in spintronic devices.

Rhizophagus irregularis improves Hg tolerance of Medicago truncatula by upregulating the Zn transporter genes ZIP2 and ZIP6.

Mercury (Hg) pollution of soils is a critical environmental problem. To rehabilitate Hg contaminated soils, arbuscular mycorrhizal (AM) fungi-based phytoremediation may be supportive, yet the functional potential of AM fungi in response to Hg exposure is unclear. In a greenhouse experiment, we assessed the response of Medicago truncatula (Hg tolerance index (TI), Hg partitioning) to different Hg concentrations [0 (Hg0), 25 (Hg25), 50 (Hg50) µg g-1] in treatments with (AM) and without (NM) inoculation of Rhizophagus irregularis. Additionally, zinc (Zn) uptake and the expression of two Zn transporter genes (ZIP2, ZIP6) were examined because Zn is an essential element for plants and shares the same outer electronic configuration as Hg, implying potential competition for the same transporters. The results showed that AM plants had a higher TI than NM plants. Plant roots were identified as dominant Hg reservoirs. AM inoculation reduced the root Hg concentration under Hg50 compared to the NM treatment. There was an interaction between Hg treatment and AM inoculation on Hg stem concentration, i.e., at Hg25, AM inoculation decreased the Hg translocation from roots to stems, while Hg translocation was increased at Hg50 compared to the NM treatment. Zn acquisition was improved by R. irregularis. The negative relationship between Hg and Zn concentrations in the roots of AM and NM plants implied potential competition for the same transporters, although the expression of Zn transporters was upregulated by AM inoculation at all Hg levels. In conclusion, this baseline study demonstrated that R. irregularis may play an important role in Hg tolerance of M. truncatula, suggesting its potential for Hg-contaminated phytoremediation.

The effects of the Promoting the Big and Quashing the Small Policy on pollutants from a coal power supply chain perspective.

China implemented the Promoting the Big and Quashing the Small Policy (PBQSP) in 2007 to alleviate air pollution due to coal-fired power plants (CFPPs). However, how the policy affected the air pollutant emissions remains poorly understood. We compared the air pollutant emissions between decommissioned and newly-built CFPPs under the PBQSP by developing a plant-level supply chain emission inventory model, taking Shandong, China's top provincial-level coal power producer, as the case area. The results indicated that compared to a 27.4% increase in electricity produced in Shandong from 2010 to 2014, the NOx, particulate matter (PM), Hg, and SO2 emissions disproportionately increased by 10.3%, 11.7%, 11.8% and 0.5%, respectively. It was found that the PBQSP policy has made great contribution to air pollution mitigation, as the supply chain emission intensities (emissions per kilowatt-hour) of NOX, PM, Hg and SO2 of the newly-built CFPPs are three-quarters, two-fifths, three-fifths, and four-fifths lower, respectively, than those of the decommissioned CFPPs. However, coal transport route changes caused an increase in NOX, PM, and SO2 emissions by 44.0%, 45.5%, and 55.6%, respectively, during the transportation stage, which offset the PBQSP overall mitigation effect. By building a comprehensive assessment framework for air pollutant control policies, our study provides insights for formulating coordinated mitigation measures for the pollutant-intensive industries, such as promoting efficient air pollutant control technologies including the spray dust suppression devices.

The determinants of China's national and regional energy-related mercury emission changes.

As the world's largest energy-related mercury emitter, proper reduction policy is urgently needed in China. However, a quantitative analysis on how different factors affect China's national and regional mercury emissions has been lacking, which hinders the design and implementation of mercury control strategies. To fill the knowledge gap, this study applies a temporal and spatial logarithmic mean divisia index (LMDI) model to reveal the important determinants of mercury emissions across China from 2007 to 2015. The results show a descendant trend generally in energy-related mercury emissions at both national and regional level. Economic scale is the main driving factor while its effect is largely offset by the decreasing mercury emission and energy intensities. However, Jiangsu and Shanxi in 2012-2015 are exceptions with emission growth because of their rebounded emission factors and energy intensities. Moreover, a decoupling effect between energy-related mercury emissions and GDP growth is found, reflecting that there is ongoing green energy transition in China. The spatial decomposition verifies that effects of economic scale and energy intensity are the mainly determinants for mercury emission differences between national average and provincial emissions. Other factors' effects are prominent in several provinces such as Xinjiang, Chongqing and Heilongjiang, where the emission gap is primarily resulted by the differences between national and local mercury intensities. By identifying the determinants of emission changes as well as the differences between the national average and provincial emissions, this study provides insights for formulating more targeted mercury mitigation strategies.

Disparities in socio-economic drivers behind China's provincial energy-related mercury emission changes.

The legally binding Minamata Convention was ratified by the Chinese government in 2017, implying that mercury emission mitigation policy design has become an urgent task ever since. As each provincial region has different energy structures and technology levels, their mercury emission profiles may have heterogeneity, thus requiring targeted regional control polices. Therefore, this study investigates the provincial energy-related mercury emissions and identifies their underlying socioeconomic factors during 2007-2012, by combining structural decomposition analysis (SDA) with the multi-regional input-output analysis (MRIO). Results show that the rising consumption per capita and decreasing emission factor are the largest contributors to emission growth and decline, respectively. However, their contributions vary significantly across regions. The rising consumption per capita leads to nearly 20 t emission increase in Shandong and Jiangsu, but less than 1 t in Qinghai. The decreasing emission factor's negative effect on mercury emission reduction is extremely important in Jiangsu, Shandong and Guangdong, but not so obvious in most western provinces. Energy efficiency is another critical contributor to mercury reduction in all provinces except Guizhou, as the coal consumption in Guizhou nearly doubled during 2007-2010. Moreover, production structure and consumption structure have opposite effects during 2007-2010 and 2010-2012: they first drive energy-related mercury emissions growing in most provinces, then inhibit the emissions especially in Shandong and Guangdong. These findings point to targeted mercury mitigation strategies (for example: improving energy efficiency in Guizhou and Liaoning, optimizing economic structure in Henan and Sichuan) for each province.

Direct and Inverse Spin Splitting Effects in Altermagnetic RuO2.

Recently, the altermagnetic materials with spin splitting effect (SSE), have drawn significant attention due to their potential to the flexible control of the spin polarization by the Néel vector. Here, the direct and inverse altermagnetic SSE (ASSE) in the (101)-oriented RuO2 film with the tilted Néel vector are reported. First, the spin torque along the x-, y-, and z-axis is detected from the spin torque-induced ferromagnetic resonance (ST-FMR), and the z-spin torque emerges when the electric current is along the [010] direction, showing the anisotropic spin splitting of RuO2. Further, the current-induced modulation of damping is used to quantify the damping-like torque efficiency (ξDL) in RuO2/Py, and an anisotropic ξDL is obtained and maximized for the current along the [010] direction, which increases with the reduction of the temperature, indicating the present of ASSE. Next, by way of spin pumping measurement, the inverse altermagnetic spin splitting effect (IASSE) is studied, which also shows a crystal direction-dependent anisotropic behavior and temperature-dependent behavior. This work gives a comprehensive study of the direct and inverse ASSE effects in the altermagnetic RuO2, inspiring future altermagnetic materials and devices with flexible control of spin polarization.

Genetic diversity and community composition of arbuscular mycorrhizal fungi associated with root and rhizosphere soil of the pioneer plant Pueraria phaseoloides.

The pioneering plant Pueraria phaseoloides had a strong modulation effect on arbuscular mycorrhizal fungi (AMF) communities. Irrespective of geographical location, community composition of AMF in rhizosphere soil differed from that of the root. Co-occurrence network analysis revealed two AMF keystone species in rhizosphere soil (Acaulospora) and roots (Rhizophagus) of P. phaseoloides.

Increasing mercury risk of fly ash generated from coal-fired power plants in China.

The trend in mercury (Hg) content of fly ash, the primary solid Hg waste from coal-fired power plants (CFPPs), has not been well evaluated in China. This study integrated a national sampling campaign, a literature survey, and model predictions to investigate the trend in Hg content of fly ash and associated output nationwide. The results demonstrated that Hg content of fly ash from both our campaign conducted in 2020 and the literature survey met the Weibull distribution. The best estimate for the distribution of Hg content in our campaign (401.4 µg/kg) was about two-fold higher than that from the literature survey (236.6 µg/kg). The increasing trend was mainly attributed to the increasing installation of advanced air pollution control devices (APCDs) in CFPPs. The total national Hg output by fly ash was estimated to be 217.7 tons (64.1-501.8 tons) currently. Regarding the disposal of fly ash, a total of 16.1 tons and 105.8 tons of Hg were re-emitted into the air and immobilized in materials, respectively. The increasing trend in the Hg content of fly ash suggested the need for more stringent requirements for the disposal of solid Hg waste from CFPPs in China.

The reallocation effect of China's provincial power transmission and trade on regional heavy metal emissions.

Coal-fired power plants (CFPPs) are key point sources to atmospheric heavy metal (HM) emissions in China. Unevenly distributed CFPPs lead to large-scale interregional power transmission, as well as corresponding environmental emissions transfer. However, the effect of power transmission on HM reallocation remains poorly understood. Here, we traced HM (including Hg, As, Se, Pb, Cd, and Cr) emission flows through electricity transmission and regional trade and calculated China's multi-perspective electricity-related HM emissions from 2010 to 2015. Results show that in 2015, power transmission and regional trade caused 226.5 t (14% of total emissions) and 453.6 t (28%) of HM emission flows, respectively, leading to great differences in provincial HM emissions under different perspectives (e.g., Beijing's consumption-based emission was 15.5 times higher than the city's production-based emission in 2015). Our study provides valuable insights for fairly allocating provincial HM emission reduction responsibility and formulating synergistic emission mitigation strategies among regions.

Rapidly changing coal-related city-level atmospheric mercury emissions and their driving forces.

The up-to-date city-level mercury emission inventory is essential for effective mitigation policy designs due to rapid changes in energy consumption and industrial structures in Chinese cities. This study updated the atmospheric mercury emission inventory in 2015 based on the most recent information on plant-specific air pollution control devices (APCDs) and coal consumption for 45 sectors in 215 Chinese cities. Total emissions were estimated at 218 t with an uncertainty range of - 54.0% to 147%, to which coal-fired industrial boilers (CFIBs) contributed 58.1%, followed by coal-fired power plants (CFPPs, 32.7%). Mercury emissions varied significantly among cities, ranging from 0.0218 to 6.89 t. The Logistics Mean Division Index (LMDI) model was then applied to identify key factors driving mercury emission changes in 50 representative cities from 2010 to 2015. Although coal consumption increased by nearly one fifth across the 50 cities, their total emissions declined by 2.36%, largely due to energy structure adjustments and widespread installations of more efficient APCDs. However, key drivers of mercury mitigation differed widely between the cities, being driven by energy intensity improvements in Chongqing and Guangzhou (Guangdong province) and by energy structure adjustments in Wuhan (Hubei province) and Yinchuan (Ningxia province). Mitigation strategies should be tailored to reflect these differences.

Magnetic Skyrmions in a Hall Balance with Interfacial Canted Magnetizations.

Magnetic skyrmions are attracting interest as efficient information-storage devices with low energy consumption, and have been experimentally and theoretically investigated in multilayers including ferromagnets, ferrimagnets, and antiferromagnets. The 3D spin texture of skyrmions demonstrated in ferromagnetic multilayers provides a powerful pathway for understanding the stabilization of ferromagnetic skyrmions. However, the manipulation mechanism of skyrmions in antiferromagnets is still lacking. A Hall balance with a ferromagnet/insulating spacer/ferromagnet structure is considered to be a promising candidate to study skyrmions in synthetic antiferromagnets. Here, high-density Néel-type skyrmions are experimentally observed at zero field and room temperature by Lorentz transmission electron microscopy in a Hall balance (core structure [Co/Pt]n /NiO/[Co/Pt]n ) with interfacial canted magnetizations because of interlayer ferromagnetic/antiferromagnetic coupling between top and bottom [Co/Pt]n multilayers, where the Co layers in [Co/Pt]n are always ferromagnetically coupled. Micromagnetic simulations show that the generation and density of skyrmions are strongly dependent on interlayer exchange coupling (IEC) and easy-axis orientation. Direct experimental evidence of skyrmions in synthetic antiferromagnets is provided, suggesting that the proposed approach offers a promising alternative mechanism for room-temperature spintronics.

[Mechanism of copper and zinc on tanshinones of cultivated Salvia miltiorrhiza].

OBJECTIVE: To study the mechanism of microelement including Cu and Zn on the accumulation of three danshinones in Salviae miltiorrhizae root and build a theory basis for its good quality and high yield. METHOD: Sand culture experiments were conducted to study the effect of Cu and Zn on the accumulation of three danshinones and oxidase including peroxidase and polyphenol oxidase activity in the plant root. The correlation between available Cu and Zn contents in matrix and oxidase activity in the plant root and, the correlation between available Cu and Zn contents in matrix and contents of tanshinones in the root were discussed. RESULT: Contents of danshinones in the root increased with the increasing of Cu and Zn concentration. Dynamic monitoring on contents of dan-shinones of the plant roots growing in the pots with different Cu and Zn concentration in the whole growing season showed that the contents of danshinones for 60 days were the lowest, for 120 days the highest and then dropped for 150 days. In addition, among available Cu and Zn contents of matrix, oxidase including peroxidase and polyphenol oxidase activity and contents of tanshinones in the root,the correlation between two factors were significant difference (P < 0.05 or P < 0.01). CONCLUSION: The mechanism of Cu and Zn on the accumulation of danshinones may be that Cu and Zn improve the activity of peroxidase and polyphenol oxidase, which promote transformation of phenolic compounds to terpenes and therefore to increase contents of danshinones.

Co[HO2C(CH2)3NH(CH2PO3H)2]2: a new canted antiferromagnet.

A new cobalt(II) carboxylate-phosphonate, namely, Co[HO2C(CH2)3NH(CH2PO3H)2]2, with a layered architecture has been synthesized by hydrothermal reactions. The Co(II) ion in the title compound is octahedrally coordinated by six phosphonate oxygen atoms from four carboxylate phosphonate ligands. Neighboring CoO6 octahedra are interconnected by phosphonate groups into a 2D layer with a 4,4-net topology. Adjacent layers are further cross-linked via hydrogen bonds between the noncoordinate carboxylate groups and noncoordinate phosphonate oxygens. The ac and dc magnetic susceptibility and magnetization measurements indicate that Co[HO2C(CH2) 3NH(CH2PO3H)2]2 is a canted antiferromagnet with T(c) = 8.75 K.

Novel polyoxometalate-templated, 3-D supramolecular networks based on lanthanide dimers: synthesis, structure, and fluorescent properties of [Ln2(DNBA)4(DMF)8][Mo6O19] (DNBA = 3,5-dinitrobenzoate).

The spherical Lindquist type polyoxometalate, Mo(6)O(19)(2)(-), has been used as a noncoordinating anionic template for the construction of novel three-dimensional lanthanide-aromatic monocarboxylate dimer supramolecular networks [Ln(2)(DNBA)(4)(DMF)(8)][Mo(6)O(19)] (Ln = La 1, Ce 2, and Eu 3, DNBA = 3,5-dinitrobenzoate, DMF = dimethylformamide). The title compounds are characterized by elemental analyses, IR, and single-crystal X-ray diffractions. X-ray diffraction experiments reveal that two Ln(III) ions are bridged by four 3,5-dinitrobenzoate anions as asymmetrically bridging ligands, leading to dimeric cores, [Ln(2)(DNBA)(4)(DMF)(8)](2+); [Ln(2)(DNBA)(4)(DMF)(8)](2+) groups are joined together by pi-pi stacking interactions between the aromatic groups to form a two-dimensional grid-like network; the 2-D supramolecular layers are further extended into 3-D supramolecular networks with 1-D box-like channels by hydrogen-bonding interactions, in which hexamolybdate polyanions reside. The compounds represent the first examples of 3-D carboxylate-bridged lanthanide dimer supramolecular "host" networks formed by pi-pi stacking and hydrogen-bonding interactions encapsulating noncoordinating "guest" polyoxoanion species. The fluorescent activity of compound 3 is reported.