Novel advanced materials and magnetic solid phase extraction as approaches in sample preparation to enhance the analysis of ochratoxin A in peanuts.

Ochratoxin A (OTA) is a mycotoxin that can contaminate a variety of agricultural commodities, including fruit juices and wines. The capability of a magnetic solid-phase extraction (MSPE) method with a magnetic metal-organic framework (MOF) material having a three-layer core-shell structure to improve the detection of OTA in food matrices using high performance liquid chromatography is described. Analysis of the material through X-ray diffraction (XRD) indicated the successful synthesis of the magnetic nanomaterial Fe3O4@SiO2@UiO66-NH2. Scanning electron microscopy (SEM) and Zetasizer lab indicated its nano-sized morphological features. The conditions affecting the magnetic solid-phase extraction procedure, such as material dosage, pH, composition and amount of eluent, desorption solution and desorption time were investigated to obtain the optimal extraction conditions. Under optimized conditions, the recoveries of spiked analytes at three different concentrations ranged from 95.83 to 101.5%, and the relative standard deviations were below 5%. Coupling with HPLC allowed the limit of detection to be 0.3 µg kg-1. This method is simple and specific, and can effectively avoid the influence of coexisting elements and improve the sensitivity of determination through fast MSPE of OTA. It has broad development prospects in OTA detection pre-treatment.

SMURF: embedding single-cell RNA-seq data with matrix factorization preserving self-consistency.

The advance in single-cell RNA-sequencing (scRNA-seq) sheds light on cell-specific transcriptomic studies of cell developments, complex diseases and cancers. Nevertheless, scRNA-seq techniques suffer from 'dropout' events, and imputation tools are proposed to address the sparsity. Here, rather than imputation, we propose a tool, SMURF, to extract the low-dimensional embeddings from cells and genes utilizing matrix factorization with a mixture of Poisson-Gamma divergent as objective while preserving self-consistency. SMURF exhibits feasible cell subpopulation discovery efficacy with obtained cell embeddings on replicated in silico and eight web lab scRNA datasets with ground truth cell types. Furthermore, SMURF can reduce the cell embedding to a 1D-oval space to recover the time course of cell cycle. SMURF can also serve as an imputation tool; the in silico data assessment shows that SMURF parades the most robust gene expression recovery power with low root mean square error and high Pearson correlation. Moreover, SMURF recovers the gene distribution for the WM989 Drop-seq data. SMURF is available at https://github.com/deepomicslab/SMURF.

Multilocus Genotyping of Giardia duodenalis in Alpine Musk Deer (Moschus chrysogaster) in China.

Giardia duodenalis is the underlying cause of a significant number of outbreaks of gastrointestinal illness in humans and animals worldwide. The purpose of this study was to elucidate the prevalence and genetic diversity of G. duodenalis in captive alpine musk deer (Moschus chrysogaster) in China. A total of 202 fecal samples were collected from three farms in Gansu Province, China. Identification of G. duodenalis was conducted by nested PCR targeting the genes coding for SSU rRNA, ß-giardin (bg), glutamate dehydrogenase (gdh) and triosephosphate isomerase (tpi). The overall prevalence of G. duodenalis in captive alpine musk deer in surveyed area was 19.3% (39/202). Two G. duodenalis genetic assemblages were identified, namely assemblage A and E. Mixed genotype infections (A+E) were found in 15.4% (6/39) of positive samples. Multilocus genotyping (MLG) analysis of G. duodenalis isolates revealed six novel assemblage A MLGs formed by two newly-described MLG-subtypes which belonged to sub-assemblage AI. To the best of our knowledge, this is the first report on MLG of G. duodenalis isolates in captive alpine musk deer in China. The presence of zoonotic assemblages and sub-assemblages of G. duodenalis in deer species suggests that these animals may potentially act as a reservoir of this protozoan for humans.

Improving soil fertility by driving microbial community changes in saline soils of Yellow River Delta under petroleum pollution.

It is promising to use indigenous microorganisms for fertility improvement in petroleum-contaminated coastal soil. As a result, the microbial community and physicochemical property are the base for the restoration. For the detailed information, the Phragmites Communis (P), Chinese Tamarisk (C), Suaeda salsa (S), and new Bare Land (B) soil of Yellow River Delta was 90 g in 100 mL sterile bottles simulated at 25 °C with soil: petroleum = 10:1 in the incubator for four months. The samples were detected at 60 and 120 days along with untreated soil and aged Oil Sludge (O) as control. The results showed that all the samples were alkaline (pH 7.99-8.83), which the salinity and NO3- content of incubate soil followed the in situ samples as P (1.09-1.72‰, 8.02-8.17 mg kg-1), C (10.61-13.79‰, 5.99-6.07 mg kg-1), S (10.19-12.43‰, 3.64-4.22 mg kg-1), B (31.85-32.45‰, 3.56-3.72 mg kg-1) and O (31.61-34.30‰, 0.89-0.90 mg kg-1). NO3- and organic carbon decreased after incubation, which the polluted samples (86.63-92.63 g kg-1) still had higher organic carbon than untreated ones with more NH4+ consumption. The high-throughput sequence results showed that the Gammaproteobacteria and Alphaproteobacteria were dominant in all samples, while sulfate reducting bacteria Alphaproteobacteria decreased at 120 days. Meanwhile, the electroactive Gammaproteobacteria might symbiosis with Methanosaetaceae and Methanosarcinaceae, degrading petroleum after electron receptors depletion. Nitrososphaeraceae and Nitrosopumilaceae oxidise NH4+ to NO2- for intra-aerobic anaerobes and denitrifying bacteria producing oxygen for biodegradation in polluted Phragmites Communis soil. The halotolerant Halomicrobiaceae and Haloferacaceae predominated in saline Chinese Tamarisk, Suaeda Salsa and Bare Land, which were potential electroactive degradater. As the ageing sludge formed, the hydrogen trophic methanogens Methanothermobacteraceae (73.90-92.72%) was prevalent with the petroleum pollution. In conclusion, petroleum initiated two-phase in the sludge forming progress: electron acceptor consumption and electron transfer between degradater and methanogens. Based on the results, the domestic sewage N, P removal coupling and electron transport will be the basement for polluted soils fertility improvement.

Effect of Solid Substrates on the Molecular Structure of Ionic Liquid Nanofilms.

Fundamental understandings of the interfacial molecular structure of solid-confined ionic liquids (ILs) have significant impacts on the development of many cutting-edge applications. Among the extensive studies on the molecular structure at the IL/solid interface, direct observation of a double-layering quantized growth of [Cnmim][FAP] on mica was recently reported. In the current work, the atomic force microscopy (AFM) results directly show that the growths of [Bmim][FAP] nanofilms on silica and amorphous carbon are different from the double-layering growth on mica. The growth of [Bmim][FAP] nanofilms on silica is dominated by the aggregation of the IL molecules, which can be attributed to the inadequate negative charging of the silica surface resulting in a weak electrostatic interaction between silica and the IL cation. [Bmim][FAP] on amorphous carbon shows a fairly smooth film for the thinner nanofilms, which can be attributed to the π-π+ parallel stacking between the cation imidazolium ring and the randomly distributed sp2 carbon on the amorphous carbon surface. Our findings highlight the effect of different IL/solid interactions, among the several competing interactions at the interface, on the resulting molecular arrangements of various IL.

Direct observation of the double-layering quantized growth of mica-confined ionic liquids.

Since the interface between ionic liquids (ILs) and solids always plays a critical role in important applications such as coating, lubrication, energy storage and catalysis, it is essential to unravel the molecular structure and dynamics of ILs confined to solid surfaces. Here we report direct observation of a unique double-layering quantized growth of three IL (i.e. [Emim][FAP], [Bmim][FAP] and [Hmim][FAP]) nanofilms on mica. AFM results show that the IL nanofilms initially grow only by covering more surface areas at the constant film thickness of 2 monolayers (ML) until a quantized increase in the film thickness by another 2 ML occurs. Based on the AFM results, we propose a double-layering model describing the molecular structure of IL cations and anions on the mica surface. The interesting double-layering structure can be explained as the result of several competing interactions at the IL-mica interface. Meanwhile, the time-dependent AFM results indicate that the topography of IL nanofilms could change with time and mobility of the nanofilm is lower for ILs with longer alkyl chains, which can be attributed to the stronger solvophobic interaction. The findings here have important implications on the molecular structure and dynamics of ILs confined to solid surfaces.

Anaerobic-petroleum degrading bacteria: Diversity and biotechnological applications for improving coastal soil.

Due to the industrial emissions and accidental spills, the critical material for modern industrial society petroleum pollution causes severe ecological damage. The prosperous oil exploitation and transportation causes the recalcitrant, hazardous, and carcinogenic sludge widespread in the coastal wetlands. The costly physicochemical-based remediation remains the secondary and inadequate treatment for the derivatives along with the tailings. Anaerobic microbial petroleum degrading biotechnology has received extensive attention for its cost acceptable, eco-friendly, and fewer health hazards. As a result of the advances in biotechnology and microbiology, the anaerobic oil-degrading bacteria have been well developing to achieve the same remediation effects with lower operating costs. This review summarizes the advantages and potential scenarios of the anaerobic degrading bacteria, such as sulfate-reducing bacteria, denitrifying bacteria, and metal-reducing bacteria in the coastal area decomposing the alkanes, alkenes, aromatic hydrocarbons, polycyclic aromatic, and related derivatives. In the future, a complete theoretical basis of microbiological biotechnology, molecular biology, and electrochemistry is necessary to make efficient and environmental-friendly use of anaerobic degradation bacteria to mineralize oil sludge organic wastes.

Reverse wedge effect following intramedullary nail fixation of trochanteric fracture, what does it imply?

Lag screw cut-out is the most common cause of fixation failure of trochanteric fractures. Intraoperative assessment of fracture reduction and fixation quality is vital to avoid fracture reduction and achieve good functional outcomes. In a recent study, Zhang et al. reported the occurrence of a reverse wedge effect after intraoperative nail insertion based on a new computed tomography(CT)-guided fracture classification system, which specifically happened to the basicervical facture type and resulted in valgus deformity with gapping at the medial inferior fracture line. Impingement between the reamer/nail and superolateral cortex of the femoral neck has been regarded as the main cause. Based on these findings, together with an extensive literature review, the practicality of the new fracture classification system, the definition of basicervical trochanteric fracture, and the mechanisms underlying the reverse wedge effect have been deeply discussed. More studies should be carried out in the future to analyse pre- and intraoperative related factors that could affect the intraoperative fragment migration effects and determine highly specific measures to address them.

Separating a multicomponent and multiphase liquid mixture with a 3D-printed membrane device.

The separation of multicomponent and multiphase liquid mixtures is critical in many important applications, e.g., wastewater treatment. While conventional technologies have been utilized in the separation, it usually takes many steps, resulting in high cost and energy consumption. Here we have demonstrated that, using a 3D-printed membrane device with multiple selectivity, a multicomponent and multiphase liquid mixture can be separated in a much more efficient way. The water-benzene-heptane mixture has been successfully separated with a 3D-printed "box", which has a supported ionic liquid membrane (SILM) on the side wall and a hydrogel-coated hydrophilic/oleophobic membrane on the bottom. The water and oil (i.e., benzene/heptane) are separated by the hydrogel-coated hydrophilic/oleophobic membrane. Then the benzene is separated from heptane with the SILM. To further increase the separation throughput, the structure of the 3D-printed "box" has been optimized to increase the total surface area of SILM. Our results suggest that 3D-printed membrane device with multiple selectivity is promising in the separation of multicomponent and multiphase liquid mixtures.

Methanobacterium Capable of Direct Interspecies Electron Transfer.

Direct interspecies electron transfer (DIET) from bacteria to methanogens is a revolutionary concept for syntrophic metabolism in methanogenic soils/sediments and anaerobic digestion. Previous studies have indicated that the potential for DIET is limited to methanogens in the Methanosarcinales, leading to the assumption that an abundance of other types of methanogens, such as Methanobacterium species, indicates a lack of DIET. We report here on a strain of Methanobacterium, designated strain YSL, that grows via DIET in defined cocultures with Geobacter metallireducens. The cocultures formed aggregates, in which cells of strain YSL and G. metallireducens were uniformly dispersed throughout. This close association of the two species is the likely explanation for the ability of a strain of G. metallireducens that could not express electrically conductive pili to grow in coculture with strain YSL. Granular activated carbon promoted the initial formation of the DIET-based cocultures. The discovery of DIET in Methanobacterium, the genus of methanogens that has been the exemplar for interspecies electron transfer via H2, suggests that the capacity for DIET is much more broadly distributed among methanogens than previously considered. More innovative approaches to microbial isolation and characterization are needed in order to better understand how methanogenic communities function.

Effects of Organic Phosphorus on Methylotrophic Methanogenesis in Coastal Lagoon Sediments With Seagrass (Zostera marina) Colonization.

Methanogens are the major contributors of greenhouse gas methane and play significant roles in the degradation and transformation of organic matter. These organisms are particularly abundant in Swan Lake, which is a shallow lagoon located in Rongcheng Bay, Yellow Sea, northern China, where eutrophication from overfertilization commonly results in anoxic environments. High organic phosphorus content is a key component of the total phosphorus in Swan Lake and is possibly a key factor affecting the eutrophication and carbon and nitrogen cycling in Swan Lake. The effects of organic phosphorus on eutrophication have been well-studied with respect to bacteria, such as cyanobacteria, unlike the effects of organic phosphorus on methanogenesis. In this study, different sediment layer samples of seagrass-vegetated and unvegetated areas in Swan Lake were investigated to understand the effects of organic phosphorus on methylotrophic methanogenesis. The results showed that phytate phosphorus significantly promoted methane production in the deepest sediment layer of vegetated regions but suppressed it in unvegetated regions. Amplicon sequencing revealed that methylotrophic Methanococcoides actively dominated in all enrichment samples from both regions with additions of trimethylamine or phytate phosphorus, whereas methylotrophic Methanolobus and Methanosarcina predominated in the enrichments obtained from vegetated and unvegetated sediments, respectively. These results prompted further study of the effects of phytate phosphorus on two methanogen isolates, Methanolobus psychrophilus, a type strain, Methanosarcina mazei, an isolate from Swan Lake sediments. Cultivation experiments showed that phytate phosphorus could inhibit methane production by M. psychrophilus but promote methane production by M. mazei. These culture-based studies revealed the effects of organic phosphorus on methylotrophic methanogenesis in coastal lagoon sediments and improves our understanding of the mechanisms of organic carbon cycling leading to methanogenesis mediated by organic phosphorus dynamics in coastal wetlands.

3D-Printed Repeating Re-Entrant Topography to Achieve On-Demand Wettability and Separation.

While it is difficult and expensive to fabricate a complicated surface structure via conventional techniques, three-dimensional (3D) printing serves as a time-efficient and cost-efficient alternative. In the current study, a novel repeating re-entrant topography is fabricated by two-photon polymerization 3D printing. The experimental results show that the repeating re-entrant surface enhances the desired on-demand surface wettability. Moreover, the 3D-printed membranes with the repeating re-entrant structures enable the efficient on-demand separation of liquid mixtures with high flux, which is critical for the wastewater treatment in the chemical industry.

Multi-walled carbon nanotubes accelerate interspecies electron transfer between Geobacter cocultures.

Carbon nanotubes (CNTs) have been reported to promote symbiotic metabolism in bacteria by accelerating interspecies electron transfer. However, this phenomenon has not been investigated or proven in a cocultures system. In this study, multi-walled CNTs (MWCNTs) were added into Geobacter cocultures systems with the ability of direct interspecies electron transfer (DIET). Results showed that addition of MWCNTs accelerated the metabolic rate of the cocultures. Succinate production rate in a test with 1.0gL-1 MWCNTs was 1.12mM d-1, 1.67 times higher than without MWCNTs. However, the biotoxicity effect became evident with the addition of much higher levels of MWCNTs addition. This study supports the possibility that carbon nanotubes accelerate interspecies electron transfer and provides a theoretical basis for the MWCNTs application in the process of anaerobic wastewater treatment.

Trophic strategy of diverse methanogens across a river-to-sea gradient.

Methanogens are an important biogenic source of methane, especially in estuarine waters across a river-to-sea gradient. However, the diversity and trophic strategy of methanogens in this gradient are not clear. In this study, the diversity and trophic strategy of methanogens in sediments across the Yellow River (YR) to the Bohai Sea (BS) gradient were investigated by high-throughput sequencing based on the 16S rRNA gene. The results showed that the diversity of methanogens in sediments varied from multitrophic communities in YR samples to specific methylotrophic communities in BS samples. The methanogenic community in YR samples was dominated by Methanosarcina, while that of BS samples was dominated by methylotrophic Methanococcoides. The distinct methanogens suggested that the methanogenic community of BS sediments did not originate from YR sediment input. High-throughput sequencing of the mcrA gene revealed that active Methanococcoides dominated in the BS enrichment cultures with trimethylamine as the substrate, and methylotrophic Methanolobus dominated in the YR enrichment cultures, as detected to a limited amount in in situ sediment samples. Methanosarcina were also detected in this gradient sample. Furthermore, the same species of Methanosarcina mazei, which was widely distributed, was isolated from the area across a river-to-sea gradient by the culture-dependent method. In summary, our results showed that a distribution of diverse methanogens across a river-to-sea gradient may shed light on adaption strategies and survival mechanisms in methanogens.

Rehabilitation treatment of spastic cerebral palsy with radial extracorporeal shock wave therapy and rehabilitation therapy.

This aims to investigate the effect of combined use of radial extracorporeal shock wave therapy (rESWT) and conventional rehabilitation therapy on postoperative rehabilitation of children with spastic cerebral palsy.Children with spastic cerebral palsy 6 weeks after multistage surgery were randomly divided into treatment group (received rESWT and conventional rehabilitation therapy) and control group (received conventional rehabilitation only). Before treatment, 2 weeks and 1 month after treatment, the Gross Motor Function Measure (GMFM), modified Ashworth Scale (MAS) of the hamstrings and triceps, plantar area and plantar pressure were examined for efficacy assessment.A total of 82 children with spastic cerebral palsy were recruited, including 43 children in treatment group and 39 children in control group. There was no significant difference in the age, MAS score, and GMFM score between the 2 groups before treatment. There were statistically significant differences between the 2 groups at 2 weeks and 4 weeks after treatment, including the MAS score, GMFM score, plantar area and plantar pressure (P < .05). Within groups, there were also significant differences at different times (P < .05).The rESWT combined with rehabilitation can quickly and effectively relieve paralysis of lower extremities, reduce the tension of hamstrings and calf muscles, relieve muscle spasm, and rapidly improve limb function in children with spastic cerebral palsy.

From Molecular Arrangement to Macroscopic Wetting of Ionic Liquids on the Mica Surface: Effect of Humidity.

To optimize the wetting performance of ionic liquids (ILs) on solid surfaces, which is important in catalysis, lubrication, and energy storage, it is critical to control the molecular arrangement of ILs at the IL/solid interface. Here, we report our experimental results, showing that tuning humidity is a facile and effective approach manipulating the molecular arrangement and thus controlling the macroscopic wettability of ILs on the mica surface. Fourier transform infrared spectroscopy, contact angle testing, and atomic force microscopy results showed that with the increase of humidity, more water adsorbs on the mica surface, which dissolves and mobilizes K+ on the mica. As a result, the cations of ILs occupy the empty spot left by the K+ and initiate the layering of ILs. The water-enabled ion exchange and IL layering processes result in not only the decrease of the IL contact angle on the mica but also the time-dependent contact angle. The finding here potentially provides a new dimension tailoring the performance of ILs at the IL/solid interface.

Surface properties of activated sludge-derived biochar determine the facilitating effects on Geobacter co-cultures.

Biochar has been reported to facilitate direct interspecies electron transfer (DIET) in co-cultures between Geobacter metallireducens and Geobacter sulfurreducens, a model defined co-culture system. In this study, the biochar derived from the activated sludge with different pyrolysis temperature was added to the co-cultures, the ethanol metabolism rates (Re) and succinate production rates (Rs) of co-culture with biochar-800 were 1.05- and 1.42-fold higher than that without addition. The results suggested that the conductivity of the biochar did not correlate with the facilitating effect of the biochar on the co-culture metabolism. Furthermore, the surface functional group and surface charge of biochar may also influence the facilitating effect on the interspecies electron transfer between the two Geobacter cells. Based on these results, it supported that the electron transfer depending on the charging and discharging process of the surface functional groups might play a major role in facilitating the direct electron transfer process by the biochar derived from activated sludge here. This study could shed light on the better understanding of the bacteria-biochar electron transfer system and the potential utilization of the biochar in the environmental wastewater treatments.

Necessity of electrically conductive pili for methanogenesis with magnetite stimulation.

BACKGROUND: Magnetite-mediated direct interspecies electron transfer (DIET) between Geobacter and Methanosarcina species is increasingly being invoked to explain magnetite stimulation of methane production in anaerobic soils and sediments. Although magnetite-mediated DIET has been documented in defined co-cultures reducing fumarate or nitrate as the electron acceptor, the effects of magnetite have only been inferred in methanogenic systems. METHODS: Concentrations of methane and organic acid were analysed with a gas chromatograph and high-performance liquid chromatography, respectively. The concentration of HCl-extractable Fe(II) was determined by the ferrozine method. The association of the defined co-cultures of G. metallireducens and M. barkeri with magnetite was observed with transmission electron micrographs. RESULTS: Magnetite stimulated ethanol metabolism and methane production in defined co-cultures of G. metallireducens and M. barkeri; however, magnetite did not promote methane production in co-cultures initiated with a culture of G. metallireducens that could not produce electrically conductive pili (e-pili), unlike the conductive carbon materials that facilitate DIET in the absence of e-pili. Transmission electron microscopy revealed that G. metallireducens and M. barkeri were closely associated when magnetite was present, as previously observed in G. metallireducens/G. sulfurreducens co-cultures. These results show that magnetite can promote DIET between Geobacter and Methanosarcina species, but not as a substitute for e-pili, and probably functions to facilitate electron transfer from the e-pili to Methanosarcina. CONCLUSION: In summary, the e-pili are necessary for the stimulation of not only G. metallireducens/G. sulfurreducens, but also methanogenic G. metallireducens/M. barkeri co-cultures with magnetite.

Spreading of Nanodroplets of Ionic Liquids on the Mica Surface.

Previously, the molecular structure of ionic liquids (ILs) next to a solid surface has been extensively studied because the IL-solid interfaces are critical to many important applications. What is largely unknown is the mobility of ILs confined to a solid surface. The solid-like stable structure of ILs on the solid surfaces has been reported in previous research, which indicates that the mobility of ILs next to a solid surface is quite low and the structure of ILs will not change with time. However, here, we show that the nanodroplets of ILs flow on the mica surface, which suggest that, at a small scale, the solid-like stable structure of ILs on the solid surfaces indeed changes with time. Interestingly, although the IL nanodroplets show a layered structure, no terrace-like flow of the droplet has been observed, which has been attributed to the weak mica-IL interaction at low humidity.

Magnetite production and transformation in the methanogenic consortia from coastal riverine sediments.

Minerals that contain ferric iron, such as amorphous Fe(III) oxides (A), can inhibit methanogenesis by competitively accepting electrons. In contrast, ferric iron reduced products, such as magnetite (M), can function as electrical conductors to stimulate methanogenesis, however, the processes and effects of magnetite production and transformation in the methanogenic consortia are not yet known. Here we compare the effects on methanogenesis of amorphous Fe (III) oxides (A) and magnetite (M) with ethanol as the electron donor. RNA-based terminal restriction fragment length polymorphism with a clone library was used to analyse both bacterial and archaeal communities. Iron (III)-reducing bacteria including Geobacteraceae and methanogens such as Methanosarcina were enriched in iron oxide-supplemented enrichment cultures for two generations with ethanol as the electron donor. The enrichment cultures with A and non-Fe (N) dominated by the active bacteria belong to Veillonellaceae, and archaea belong to Methanoregulaceae and Methanobacteriaceae, Methanosarcinaceae (Methanosarcina mazei), respectively. While the enrichment cultures with M, dominated by the archaea belong to Methanosarcinaceae (Methanosarcina barkeri). The results also showed that methanogenesis was accelerated in the transferred cultures with ethanol as the electron donor during magnetite production from A reduction. Powder X-ray diffraction analysis indicated that magnetite was generated from microbial reduction of A and M was transformed into siderite and vivianite with ethanol as the electron donor. Our data showed the processes and effects of magnetite production and transformation in the methanogenic consortia, suggesting that significantly different effects of iron minerals on microbial methanogenesis in the iron-rich coastal riverine environment were present.