P-hydroxybenzoic acid positively affect the Fusarium oxysporum to stimulate root rot in Panax notoginseng.

Background: Plant health is directly related to the change in native microbial diversity and changes in soil health have been implicated as one of the main cause of root rot. However, scarce information is present regarding allelopathic relationship of Panax notoginseng root exudates and pathogenic fungi Fusarium oxysporum in a continuous cropping system. Methods: We analyzed P. notoginseng root exudate in the planting soil for three successive years to determine phenolic acid concentration using GC-MS and HPLC followed by effect on the microbial community assembly. Antioxidant enzymes were checked in the roots to confirm possible resistance in P. notoginseng. Results: Total 29 allelochemicals in the planting soil extract was found with highest concentration (10.54 %) of p-hydroxybenzoic acid. The HPLC showing a year-by-year decrease in p-hydroxybenzoic acid content in soil of different planting years, and an increase in population of F. oxysporum. Moreover, community analysis displayed negative correlation with 2.22 mmol. L-1 of p-hydroxybenzoic acid correspond to an 18.1 % population of F. oxysporum. Furthermore, in vitro plate assay indicates that medium dose of p-hydroxybenzoic acid (2.5-5 mmol. L-1) can stimulate the growth of F. oxysporum colonies and the production of macroconidia, as well as cell wall-degrading enzymes. We found that 2-3 mmol. L-1 of p-hydroxybenzoic acid significantly increased the population of F. oxysporum. Conclusion: In conclusion, our study suggested that p-hydroxybenzoic acid have negative effect on the root system and modified the rhizosphere microbiome so that the host plant became more susceptible to root rot disease.

A novel approach on designing ultrahigh burnup metallic TWR fuels: Upsetting the current technological limits.

Abstract: The grand challenge of "net-zero carbon" emission calls for technological breakthroughs in energy production. The traveling wave reactor (TWR) is designed to provide economical and safe nuclear power and solve imminent problems, including limited uranium resources and radiotoxicity burdens from back-end fuel reprocessing/disposal. However, qualification of fuels and materials for TWR remains challenging and it sets an "end of the road" mark on the route of R&D of this technology. In this article, a novel approach is proposed to maneuver reactor operations and utilize high-temperature transients to mitigate the challenges raised by envisioned TWR service environment. Annular U-50Zr fuel and oxidation dispersion strengthened (ODS) steels are proposed to be used instead of the current U-10Zr and HT-9 ferritic/martensitic steels. In addition, irradiation-accelerated transport of Mn and Cr to the cladding surface to form a protective oxide layer as a self-repairing mechanism was discovered and is believed capable of mitigating long-term corrosion. This work represents an attempt to disruptively overcome current technological limits in the TWR fuels. Impact statement: After the Fukushima accident in 2011, the entire nuclear industry calls for a major technological breakthrough that addresses the following three fundamental issues: (1) Reducing spent nuclear fuel reprocessing demands, (2) reducing the probability of a severe accident, and (3) reducing the energy production cost per kilowatt-hour. An inherently safe and ultralong life fast neutron reactor fuel form can be such one stone that kills the three birds. In light of the recent development findings on U-50Zr fuels, we hereby propose a disruptive, conceptual metallic fuel design that can serve the following purposes at the same time: (1) Reaching ultrahigh burnup of above 40% FIMA, (2) possessing strong inherent safety features, and (3) extending current limits on fast neutron irradiation dose to be far beyond 200 dpa. We believe that this technology will be able to bring about revolutionary changes to the nuclear industry by significantly lowering the operational costs as well as improving the reactor system safety to a large extent. Supplementary information: The online version contains supplementary material available at 10.1557/s43577-022-00420-4.

The use of free myocutaneous flap and implant reinsertion for staged cranial reconstruction in patients with titanium mesh exposure and large skull defects with soft tissue infection after cranioplasty: Report of 19 cases.

BACKGROUND: Management of cranial defects following failed cranioplasty due to titanium mesh exposure and infection is challenging. The purpose of this report is to describe a modified technique using a free myocutaneous flap transfer for primary soft tissue reconstruction, and titanium mesh reinsertion for cranioplasty revision. METHODS: Nineteen patients with titanium mesh exposure and infection following cranioplasty were treated from January 2012 to January 2019. The average patient age was 41.89 years and the average size of the cranial defect was 7.74 × 13.92 cm. The reasons for craniotomy were craniocerebral trauma (n = 17), cerebrovascular disease (n = 1), and brain tumor (n = 1). The mean duration between implant exposure and current procedure was 7.16 months. Implant was removed and a free myocutaneous flap was designed to cover both scalp and cranium defects. After a mean duration of 12.32 months, implants were re-inserted in a vascularized pocket at the second stage by elevating a plane between the previously transferred fascia layer and muscle layer. RESULTS: The average sizes of the muscle flaps and skin paddles were 7.74 × 13.92 cm and 4.97 × 8.97 cm. The average size of the implants was 8.24 × 14.42 cm. All flaps survived completely with no complication. After an average follow-up of 48.16 months there were no cranioplasty failures. Functional coverage of craniectomy defect sites with normalized head contour was achieved. CONCLUSIONS: The use of free myocutaneous flap and implant reinsertion achieved durable cranial and scalp defect reconstruction and aesthetic outcomes. The myocutaneous flap increases blood supply to the scalp, which may reduce the chances of infection and implant re-exposure.

Occurrence of antibiotics and antibiotic resistance genes in the Fuxian Lake and antibiotic source analysis based on principal component analysis-multiple linear regression model.

In recent years, the dramatic increase in antibiotic use has led to the evolution of antibiotic resistant genes (ARGs), posing a potential risk to human and aquatic ecological safety. In this study, source contribution and correlations between twelve antibiotics and their corresponding ARGs were firstly investigated in surface water in the Fuxian Lake. The results showed that sulfamethoxazole (SMX) (0.98-14.32 ng L-1) and ofloxacin (OFL) (0.77-7.3 ng L-1) were the dominant antibiotics in surface water, whereas erythromycin-H2O (EM-H2O), SMX and OFL posed the medium risk to aquatic organisms. Meanwhile, the mean concentrations of MLs in inflowing rivers were 5.6 times more than those in the lake, which was related to dilution and degradation. Moreover, the facter1 (co-sources L (Living quarters), M (Mining area), A (Agricultural district) and T (tourist area)) contributed 78% of antibiotic concentrations, and the source L was predominant. The results also revealed the prevalence of intL1, sul1 and sul2 in all the sampling sites, and that the abundance of ARGs in the lake was significantly lower (P < 0.01) than that in inflowing rives. Additionally, significant correlations (p < 0.0001) between intL1 and sulfanilamide resistance genes (sul1, sul2) were detected, indicating that intL1 promoted the propagation and they originated from the same anthropogenic sources. Overall, our findings revealed the presence of antibiotics and ARGs and their inconsistent correlations in the Fuxian Lake, which provides a foundation to support further exploration of the occurrence and transmission mechanisms of antibiotics and ARGs.

Establishment of quantitative retention-activity model by optimized microemulsion liquid chromatography.

The effective permeability coefficient is of theoretical and practical importance in evaluation of the bioavailability of drug candidates. However, most methods currently used to measure this coefficient are expensive and time-consuming. In this paper, we addressed these problems by proposing a new measurement method which is based on the microemulsion liquid chromatography. First, the parallel artificial membrane permeability assays model was used to determine the effective permeability of drug so that quantitative retention-activity relationships could be established, which were used to optimize the microemulsion liquid chromatography. The most effective microemulsion system used a mobile phase of 6.0% (w/w) Brij35, 6.6% (w/w) butanol, 0.8% (w/w) octanol, and 86.6% (w/w) phosphate buffer (pH 7.4). Next, support vector machine and back-propagation neural networks are employed to develop a quantitative retention-activity relationships model associated with the optimal microemulsion system, and used to improve the prediction ability. Finally, an adequate correlation between experimental value and predicted value is computed to verify the performance of the optimal model. The results indicate that the microemulsion liquid chromatography can serve as a possible alternative to the PAMPA method for determination of high-throughput permeability and simulation of biological processes.

Simultaneous Determination of Hydrochlorothiazide and Losartan Potassium in Osmotic Pump Tablets by Microemulsion Liquid Chromatography.

A rapid and efficient oil-in-water microemulsion liquid chromatographic (MELC) method has been optimized and validated for the determination of hydrochlorothiazide (HCT) and losartan potassium (LOP) in osmotic pump tablets. Samples were injected into a C18 (150 mm × 4.6 mm ID, 5 µm particle size) analytical column, which was maintained at 30°C. The most effective MELC system had a mobile phase consisting of 95% (v/v) of 3.0% (w/w) SDS, 6.0% (w/w) n-butanol, 0.8% (w/w) n-octane, 90.2% (w/w) water and 5% (v/v) acetonitrile (pH 5). The flow rate was 1.0 mL min(-1) and UV detection was performed at 265 nm. Linearity ranged from 2.5 to 12.5 µg mL(-1) for HCT and 10.0-60.0 µg mL(-1) for LOP (r > 0.999 for both drugs). The proposed method was rapid, precise (RSDs < 1.4%) and accurate (98.9% recovery for HCT and 101% recovery for LOP). It is applicable to simultaneous determination of HCT and LOP in osmotic pump tablets.

Determination of the lipophilicity of Salvia miltiorrhiza Radix et Rhizoma (danshen root) ingredients by microemulsion liquid chromatography: optimization using cluster analysis and a linear solvation energy relationship-based method.

We evaluated 26 microemulsion liquid chromatography (MELC) systems for their potential as high-throughput screening platforms capable of modeling the partitioning behaviors of drug compounds in an n-octanol-water system, and for predicting the lipophilicity of those compounds (i.e. logP values). The MELC systems were compared by cluster analysis and a linear solvation energy relationship (LSER)-based method, and the optimal system was identified by comparing their Euclidean distances with the LSER coefficients. The most effective MELC system had a mobile phase consisting of 6.0% (w/w) Brij35 (a detergent), 6.6% (w/w) butanol, 0.8% (w/w) cyclohexane, 86.6% (w/w) buffer solution and 8 mm cetyltrimethyl ammonium bromide. The reliability of the established platform was confirmed by the agreement between the experimental data and the predicted values. The logP values of the ingredients of danshen root (Salvia miltiorrhiza Radix et Rhizoma) were then predicted. Copyright © 2015 John Wiley & Sons, Ltd.

Determination of drug lipophilicity by phosphatidylcholine-modified microemulsion high-performance liquid chromatography.

A new biomembrane-mimetic liquid chromatographic method using a C8 stationary phase and phosphatidylcholine-modified (PC-modified) microemulsion mobile phase was used to estimate unionized and ionized drugs lipophilicity expressed as an n-octanol/water partition coefficient (logP and logD). The introduction of PC into sodium dodecyl sulfate (SDS) microemulsion yielded a good correlation between logk and logD (R(2)=0.8). The optimal composition of the PC-modified microemulsion liquid chromatography (PC-modified MELC) mobile phase was 0.2% PC-3.0% SDS-6.0% n-butanol-0.8% ethyl acetate-90.0% water (pH 7.0) for neutral and ionized molecules. The interactions between the analytes and system described by this chromatographic method is more similar to biological membrane than the n-octanol/water partition system. The result in this paper suggests that PC-modified MELC can serve as a possible alternative to the shake-flask method for high-throughput unionized and ionized drugs lipophilicity determination and simulation of biological processes.

Determination of the lipophilicity (log P o/w) of organic compounds by microemulsion liquid chromatography.

Four microemulsion liquid chromatography (MELC) systems and one micellar liquid chromatography (MLC) system have been evaluated as potential high-throughput screening platforms capable of modeling the partitioning behaviors of drug compounds in an n-octanol/water system and predicting their lipophilicity (i.e., log P values). The microemulsion mobile phases is consisted of sodium dodecyl sulfate (SDS), butanol, octane, heptanes, octanol and water. A linear solvation energy relationship (LSER)-based method was used to compare the MELC and MLC systems, as well as several other biochemical systems, and to identify the optimal system by comparing their Euclidean distances with the LSER coefficients. The most effective MELC system had a mobile phase consisting of 3.0% (w/w) SDS, 6.0% (w/w) butanol, 0.8% (w/w) octanol, and 90.2% (w/w) water (pH 6.4). The results showed that it gave superior results to the other chromatographic systems in terms of its ability to predict the log P values of drug compounds.