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Tropical forests are sensitive to nitrogen (N) and phosphorus (P) availability, and under nutrient application the variation of soil organic carbon (SOC) preserving mechanism remains to be explored. To reveal the forest-specific SOC preservation via biochemical selection in response to nutrient application, we investigated a monoculture (Acacia plantation) and a multispecies forest both with chronic fertilization in subtropical regions, and measured specific fingerprints of plant- and microbial-derived C compounds. In addition, to quantify the effect of P application on SOC content among tropical forests, we conducted a meta-analysis by compiling 125 paired measurements in field experiments from 62 studies. In our field experiment, microbial community composition and activity mediated forest-specific responses of SOC compounds to P addition. The shift of community composition from fungi towards Gram-positive bacteria in the Acacia plantation by P addition led to the consumption of microbial residual C (MRC) as C source; in comparison, P addition increased plant species with less complex lignin substrates and induced microbial acquisition for N sources, thus stimulated the decomposition of both plant- and microbial-derived C. Same with our field experiment, bulk SOC content had neutral response to P addition among tropical forests in the meta-analysis, although divergences could happen among experimental durations and secondary tree species. Close associations among SOC compounds with biotic origins and mineral associated organic C (MAOC) in the multispecies forest suggested contributions of both plant- and microbial-derive C to SOC stability. Regarding that fungal MRC closely associated with MAOC and consisted of soil N pool which tightly coupled to SOC pool, the reduce of fungal MRC by chronic P addition was detrimental to SOC accumulation and stability in tropical forests.
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Carbono , Bosques , Fósforo , Microbiología del Suelo , Suelo , Fósforo/análisis , Suelo/química , Carbono/análisis , Fertilizantes/análisis , Clima Tropical , Nitrógeno/análisis , Árboles , Agricultura/métodosRESUMEN
Separation membranes with homogeneous charge channels are the mainstream to reject charged mass by forming electrical double layer (EDL). However, the EDL often compresses effective solvent transport space and weakens channel-ion interaction. Here, built-in electric fields (BIEFs) are constructed in lamellar membranes by assembling the heterostructured nanosheets, which contain alternate positively-charged nanodomains and negatively-charged nanodomains. We demonstrate that the BIEFs are perpendicular to horizontal channel and the direction switches alternately, significantly weakening the EDL effect and forces ions to repeatedly collide with channel walls. Thus, highly efficient rejection for charged mass (salts, dyes, and organic acids/bases) and ultrafast water transport are achieved. Moreover, for desalination on four-stage filtration option, salt rejection reaches 99.9 % and water permeance reaches 19.2â L m-2 h-1 bar-1. Such mass transport behavior is quite different from that in homogeneous charge channels. Furthermore, the ion transport behavior in nanochannels is elucidated by validating horizontal projectile motion model.
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The GLK gene family plays a crucial role in the regulation of chloroplast development and participates in chlorophyll synthesis. However, the precise mechanism by which GLK contributes to citrus's chlorophyll synthesis remains elusive. The GLK gene family causes variations in the photosynthetic capacity and chlorophyll synthesis of different citrus varieties. In this study, we identified tissue-specific members and the key CcGLKs involved in chlorophyll synthesis. A total of thirty CcGLK transcription factors (TFs) were discovered in the citrus genome, distributed across all nine chromosomes. The low occurrence of gene tandem duplication events and intronic variability suggests that intronic variation may be the primary mode of evolution for CcGLK TFs. Tissue-specific expression patterns were observed for various GLK family members; for instance, CcGLK12 and CcGLK15 were specifically expressed in the skin, while CcGLK30 was specific to the ovary, and CcGLK10, CcGLK6, CcGLK21, CcGLK2, CcGLK18, CcGLK9, CcGLK28, and CcGLK8 were specifically expressed in the leaves. CcGLK4, CcGLK5, CcGLK11, CcGLK23, CcGLKl7, CcGLK26, and CcGLK20 may participate in the regulation of the ALA, prochlorophylate, protoporphyrin IX, Mg-protoporphyrin IX, Chl b, T-Chl, MG-ProtoIX ME, and POR contents in citrus.
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BACKGROUND: Dental fear and anxiety (DFA) is a condition that affects approximately one-quarter of children and adolescents. It is a significant cause for pediatric patients to avoid dental care later in adulthood. Lack of patient cooperation due to DFA can create an environment of stress, often obligating dentists to end appointments prematurely and consider alternative pharmacological treatment options. Virtual reality (VR) use during dental care, providing an immersive experience through sensory stimuli, is potentially an additional nonpharmacologic tool to better manage DFA in children with special health care needs (SHCN) undergoing dental procedures. OBJECTIVE: This pilot study aims to assess the feasibility and acceptability of VR immersion as a tool to reduce DFA in pediatric special needs patients undergoing dental procedures. The study also aims to gain insight on parent and health care provider perspectives on the use of VR during dental appointments. METHODS: This pilot randomized controlled trial study will follow a parallel design including 2 groups: a control group (clinic's standard care using a wall TV) and an experimental group (using a VR game). We will randomize 20 participants to either group. Recruitment will be carried out at the dental clinic of the Centre Hospitalier Universitaire Sainte-Justine, a tertiary-quaternary care center that mostly serves pediatric patients with SHCN. The primary outcome will be patient recruitment rates and completion rates of planned procedures. DFA in children will be assessed using both an observation-based proxy assessment with the Venham Anxiety and Behavior Rating Scale and physiological assessments using parameters such as change in heart rate and levels of salivary alpha-amylase as a stress biomarker before and 10 minutes after the procedure. Sociodemographic characteristics, measures of the levels of parent and health care professional satisfaction, occurrence of side effects, and any deviation from normal procedure length will also be collected. Descriptive statistics, nonparametric tests, and effect sizes will be used for demographic and clinical variables and to present parent and health care professional satisfaction levels as well as procedural time. RESULTS: This study will be conducted from May 2023 to May 2024, with results expected to be available in December 2024. CONCLUSIONS: The pilot study will provide insight on the feasibility and acceptability of VR use in clinical dentistry to reduce DFA for pediatric patients with SHCN. This study will guide future research on VR use in pediatric dentistry and can serve as a framework for a larger randomized clinical trial. TRIAL REGISTRATION: ClinicalTrials.gov NCT05898100; https://classic.clinicaltrials.gov/ct2/show/NCT05898100. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/49956.
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Ras proteins are monomeric G proteins that are ubiquitous in fungal cells and play important roles in fungal growth, virulence, and environmental responses. Botrytis cinerea is a phytopathogenic fungus that infects various crops. However, under specific environmental conditions, the overripe grapes infected by B. cinerea can be used to brew valuable noble rot wine. As a Ras protein, the role of Bcras2 in the environmental responses of B. cinerea is poorly understood. In this study, we deleted the Bcras2 gene using homologous recombination and examined its functions. Downstream genes regulated by Bcras2 were explored using RNA sequencing transcriptomics. It was found that ΔBcras2 deletion mutants showed significantly reduced growth rate, increased sclerotia production, decreased resistance to oxidative stress, and enhanced resistance to cell wall stress. Additionally, Bcras2 deletion promoted the expression of melanin-related genes in sclerotia and decreased the expression of melanin-related genes in conidia. The above results indicate that Bcras2 positively regulates growth, oxidative stress resistance, and conidial melanin-related genes expression, and negatively regulates sclerotia production, cell wall stress resistance and sclerotial melanin-related genes expression. These results revealed previously unknown functions of Bcras2 in environmental responses and melanin metabolism in B. cinerea.
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Tropical primary forests are being destroyed at an alarming rate and converted for other land uses which is expected to greatly influence soil carbon (C) cycling. However, our understanding of how tropical forest conversions affect the accumulation of compounds in soil functional C pools remains unclear. Here, we collected soils from primary forests (PF), secondary forests (SF), oil-palm (OP), and rubber plantations (RP), and assessed the accumulation of plant- and microbial-derived compounds within soil organic carbon (SOC), particulate (POC) and mineral-associated (MAOC) organic C. PF conversion to RP greatly decreased SOC, POC, and MAOC concentrations, whereas conversion to SF increased POC concentrations and decreased MAOC concentrations, and conversion to OP only increased POC concentrations. PF conversion to RP decreased lignin concentrations and increased amino sugar concentrations in SOC pools which increased the stability of SOC, whereas conversion to SF only increased the lignin concentrations in POC, and conversion to OP just increased lignin concentrations in POC and decreased it in MAOC. We observed divergent dynamics of amino sugars (decrease) and lignin (increase) in SOC with increasing SOC. Only lignin concentrations increased in POC with increasing POC and amino sugars concentrations decreased in MAOC with increasing MAOC. Conversion to RP significantly decreased soil enzyme activities and microbial biomasses. Lignin accumulation was associated with microbial properties, whereas amino sugar accumulation was mainly associated with soil nutrients and stoichiometries. These results suggest that the divergent accumulation of plant- and microbial-derived C in SOC was delivered by the distribution and original composition of functional C pools under forest conversions. Forest conversions changed the formation and stabilization processes of SOC in the long run which was associated with converted plantations and management. The important roles of soil nutrients and stoichiometry also provide a natural-based solution to enhance SOC sequestration via nutrient management in tropical forests.
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Carbono , Suelo , Lignina , Bosques , Biomasa , GomaRESUMEN
One scalable and facile dip-coating approach was utilized to construct a thin CO2-selection layer of Pebax/PEGDA-MXene on a hollow fiber PVDF substrate. An interlayer spacing of 3.59 Å was rationally designed and precisely controlled for the MXene stacks in the coated layer, allowing efficient separation of the CO2 (3.3 Å) from N2 (3.6 Å) and CH4 (3.8 Å). In addition, CO2-philic nanodomains in the separation layer were constructed by grafting PEGDA into MXene interlayers, which enhanced the CO2 affinity through the MXene interlayers, while non-CO2-philic nanodomains could promote CO2 transport due to the low resistance. The membrane could exhibit optimal separation performance with a CO2 permeance of 765.5 GPU, a CO2/N2 selectivity of 54.5, and a CO2/CH4 selectivity of 66.2, overcoming the 2008 Robeson upper bounds limitation. Overall, this facile approach endows a precise controlled molecular sieving MXene membrane for superior CO2 separation, which could be applied for interlayer spacing control of other 2D materials during membrane construction.
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Microbial metabolic products play a vital role in maintaining ecosystem multifunctionality, such as soil physical structure and soil organic carbon (SOC) preservation. Afforestation is an effective strategy to restore degraded land. Glomalin-related soil proteins (GRSP) and amino sugars are regarded as stable microbial-derived C, and their distribution within soil aggregates affects soil structure stability and SOC sequestration. However, the information about how afforestation affects the microbial contribution to SOC pools within aggregates is poorly understood. We assessed the accumulation and contribution of GRSP and amino sugars within soil aggregates along a restoration chronosequence (Bare land, Eucalyptus exserta plantation, native species mixed forest, and native forest) in tropical coastal terraces. Amino sugars and GRSP concentrations increased, whereas their contributions to the SOC pool decreased along the restoration chronosequence. Although microaggregates harbored greater microbial abundances, amino sugars and GRSP concentrations were not significantly affected by aggregate sizes. Interestingly, the contributions of amino sugars and GRSP to SOC pools decreased with decreasing aggregate size which might be associated with increased accumulation of plant-derived C. However, the relative change rate of GRSP was consistently greater in all restoration chronosequences than that of amino sugars. The accumulation of GRSP and amino sugars in SOC pools was closely associated with the dynamics of soil fertility and the microbial community. Our findings suggest that GRSP accumulates faster and contributes more to SOC pools during restoration than amino sugars did which was greatly affected by aggregate sizes. Afforestation substantially enhanced soil quality with native forest comprising species sequestering more SOC than the monoculture plantation did. Such information is invaluable for improving our mechanistic understanding of microbial control over SOC preservation during degraded ecosystem restoration. Our findings also show that plantations using arbuscular mycorrhizal plants can be an effective practice to sequester more soil carbon during restoration.
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Carbono , Suelo , Suelo/química , Carbono/análisis , Ecosistema , Amino Azúcares , Proteínas Fúngicas/metabolismo , Secuestro de Carbono , ChinaRESUMEN
Purpose: Healthcare professionals (HCP) perform various needle procedures that can be distressing and painful for children and adults. Even though many strategies have been proven effective in reducing distress and pain, topical anesthetic use before needle procedures is uncommon. However, there are limited studies in the existing literature comparing specifically liposomal lidocaine and tetracaine hydrochloride topical creams. Source: This systematic review analyzed studies on the use of two anesthetic creams, Liposomal Lidocaine (Maxilene®) and Tetracaine hydrochloride (Ametop™), in children and adults undergoing a needle-related procedure. Databases searched: PubMed, CINAHL, ClinicalTrials. Only randomized controlled trials (RCT) and Controlled Clinical Trials (CCT) studies were included. Cochrane Collaboration's Risk of Bias assessment tool was used. Strictly minimally invasive procedures were included to standardize different skin needle interventions. Principal findings: Only one study with 60 participants was available to be included in this review. No statistically significant difference was found in the mean pain score among both interventions. The outcomes of self-reported distress during cannulation and on HCP satisfaction were not reported. However, physiological characteristics associated with stress/anxiety and on cannulation success rate were reported and did not show statistical significance. Conclusion: Little to no evidence regarding the most efficient cream between liposomal lidocaine and tetracaine hydrochloride for pain management during needle-related procedures was found. Further studies, particularly RCT with larger sample sizes and standardized outcome measures, are needed to confirm the relative efficacy of either anesthetic cream.
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BACKGROUND: Danshen injection (DSI) is an agent extracted from the Salvia miltiorrhiza Bunge, a natural drug commonly used to alleviate kidney diseases. However, the material basis and therapeutic effects of DSI on nephrotic syndrome (NS) remain unclear. PURPOSE: To investigate the material basis of DSI and the therapeutic effects and underlying mechanisms of NS. METHODS: NS models were established using adriamycin-induced BALB/c mice and lipopolysaccharide-induced mouse podocytes (MPC-5). Following DSI and prednisone administration, kidney coefficients, 24 h urine protein, blood urea nitrogen, and serum creatinine levels were tested. Histomorphology was observed by periodic acid-Schiff staining and hematoxylin and eosin staining of the kidney sections. The glomerular basement membrane and autophagosomes of the kidneys were observed using transmission electron microscopy. Nephrin and desmin levels in the glomeruli were tested using immunohistochemistry. The viability of MPC-5 cells was tested using cell counting kit-8 after chloroquine and rapamycin administration in combination with DSI. The in vivo and in vitro protein levels of phosphatidylinositol 3-kinase (PI3K), AKT, phosphorylated AKT (Ser473), mammalian target of rapamycin (mTOR), microtubule-associated protein light chain 3 (LC3), beclin1, cleaved caspase-3, and caspase-3 were detected using western blotting. RESULTS: Our results showed that DSI contained nine main components: caffeic acid, danshensu, lithospermic acid, rosmarinic acid, salvianolic acid A, salvianolic acid B, salvianolic acid C, salvianolic acid D, and 3, 4-Dihydroxybenzaldehyde. In in vivo studies, the NS mice showed renal function and pathological impairment. Podocytes were damaged, with decreased levels of autophagy and apoptosis, accompanied by inhibition of the PI3K/AKT/mTOR signaling. DSI administration resulted in improved renal function and pathology in NS mice, with the activation of autophagy and PI3K/AKT/mTOR signaling in the kidneys. Additionally, podocytes were less damaged and intracellular autophagosomes were markedly increased. In vitro studies have shown that DSI activated MPC-5 autophagy and reduced apoptosis via the PI3K/AKT/mTOR pathway. CONCLUSION: Collectively, this study demonstrated that DSI activated podocyte autophagy and reduced apoptosis via the PI3K/AKT/mTOR signaling, ultimately attenuating NS. Our study clarified the main components of DSI and elucidated its therapeutic effects and potential mechanisms for NS, providing new targets and agents for the clinical treatment of NS.
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Síndrome Nefrótico , Podocitos , Salvia miltiorrhiza , Animales , Autofagia , Beclina-1/metabolismo , Caspasa 3/metabolismo , Cloroquina/farmacología , Creatinina , Desmina/metabolismo , Desmina/farmacología , Doxorrubicina/farmacología , Eosina Amarillenta-(YS)/metabolismo , Eosina Amarillenta-(YS)/farmacología , Hematoxilina/metabolismo , Hematoxilina/farmacología , Lipopolisacáridos/farmacología , Mamíferos/metabolismo , Ratones , Proteínas Asociadas a Microtúbulos/metabolismo , Síndrome Nefrótico/inducido químicamente , Síndrome Nefrótico/tratamiento farmacológico , Síndrome Nefrótico/metabolismo , Ácido Peryódico/metabolismo , Ácido Peryódico/farmacología , Fosfatidilinositol 3-Quinasa/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Podocitos/metabolismo , Prednisona/metabolismo , Prednisona/farmacología , Proteínas Proto-Oncogénicas c-akt/metabolismo , Sirolimus/farmacología , Serina-Treonina Quinasas TOR/metabolismoRESUMEN
Activation of inflammation is an important pathogenic factor contributing to the development of chronic kidney disease (CKD). Recent studies manifested the implication of impaired mitophagy mediated NLRP3 inflammasome activation in the progression of CKD. Mitochondria-targeted antioxidant mitoTEMPO showed antioxidant and anti-inflammatory properties in kidney disease. This study aims to investigate the protective mechanism of mitoTEMPO on podocyte injury related to mitophagy and NLRP3 inflammasome. Our results showed that mitoTEMPO obviously ameliorated renal function and podocyte injury in CKD model rats induced by cationic bovine serum albumin (C-BSA). More importantly, mitoTMEPO significantly inhibited NLRP3 inflammasome activation compared with CKD model rats (P < 0.01). In vitro, TNF-α damaged human podocyte cells (HPC) and activated NLRP3 inflammasome, which was rescued by NLRP3 inhibitor and mitoTEMPO. Meanwhile, mitoTEMPO lessened excessive mitochondrial ROS (mtROS) and degressive mitochondrial membrane potential (MMP) in HPC. We also found that mitoTEMPO induced mitophagy in vivo and in vitro. Moreover, silenced Parkin dramatically reserved the inhibitory effect of mitoTEMPO on NLRP3 inflammasome. Taking together, these findings reveal that mitoTEMPO ameliorated podocyte injury by inhibiting NLRP3 inflammasome via PINK1/Parkin pathway-mediated mitophagy. MitoTEMPO may be a new candidate to protect against podocyte injury in CKD.
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Podocitos , Insuficiencia Renal Crónica , Animales , Antioxidantes/farmacología , Humanos , Inflamasomas , Mitofagia , Proteína con Dominio Pirina 3 de la Familia NLR , Compuestos Organofosforados , Piperidinas , Proteínas Quinasas , Ratas , Especies Reactivas de Oxígeno , Ubiquitina-Proteína LigasasRESUMEN
Inorganic superionic conductor holds great promise for high-performance all-solid-state lithium batteries. However, the ionic conductivity of traditional inorganic solid electrolytes (ISEs) is always unsatisfactory owing to the grain boundary resistance and large thickness. Here, a 13â µm-thick laminar framework with ≈1.3â nm interlayer channels is fabricated by self-assembling rigid, hydrophilic vermiculite (Vr) nanosheets. Then, Li0.33 La0.557 TiO3 (LLTO) precursors are impregnated in interlayer channels and afterwards in situ sintered to large-size, oriented, and defect-free LLTO crystal. We demonstrate that the confinement effect permits ordered arrangement of LLTO crystal along the c-axis (the fastest Li+ transfer direction), permitting the resultant 15â µm-thick Vr-LLTO electrolyte an ionic conductivity of 8.22×10-5 â S cm-1 and conductance of 87.2â mS at 30 °C. These values are several times' higher than that of traditional LLTO-based electrolytes. Moreover, Vr-LLTO electrolyte has a compressive modulus of 1.24â GPa. Excellent cycling performance is demonstrated with all-solid-state Li/LiFePO4 battery.
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Afforestation is an effective method to restore degraded land. Afforestation methods vary in their effects on ecosystem multifunctionality, but their effects on soil biodiversity have been largely overlooked. Here, we mapped the biodiversity and functioning of multiple soil organism groups resulting from diverse afforestation methods in tropical coastal terraces. Sixty years after afforestation from bare land (BL), plant species richness and the abundance of plant litter (398 ± 85 g m-2 ) and plant biomass (179 ± 3.7 t ha-1 ) in native tree species mixtures (MF) were restored to the level of native forests (NF; 287 ± 21 g m-2 and 243.0 ± 33 t ha-1 , respectively), while Eucalyptus monoculture (EP) only successfully restored the litter mass (388 ± 43 g m-2 ) to the level of NF. Soil fertility in EP and MF was increased but remained lower than in NF. For example, soil nitrogen and phosphorus concentrations in MF (1.2 ± 0.2 g kg-1 and 408 ± 49 mg kg-1 , respectively; p < 0.05) were lower than in NF (1.8 ± 0.2 g kg-1 and 523 ± 24 mg kg-1 , respectively; p < 0.05). Soil biodiversity, abundance (except for nematodes), and community composition in MF were similar or greater than those in NF. In contrast, restoration with EP only enhanced the diversity of microbes and mites to the level of NF, but not for other soil biota. Together, afforestation with native species mixtures can end up restoring vegetation and most aspects of the taxonomic and functional biodiversity in soil whereas monoculture using fast-growing non-native species cannot. Native species mixtures show a greater potential to reach completely similar levels of soil biodiversity in local natural forests if they are received some more decades of afforestation. Multifunctionality of soil biotic community should be considered to accelerate such processes in future restoration practices.
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Eucalyptus , Suelo , Biodiversidad , Ecosistema , BosquesRESUMEN
The soil nitrogen (N) and phosphorus (P) availability often constrains soil carbon (C) pool, and elevated N deposition could further intensify soil P limitation, which may affect soil C cycling in these N-rich and P-poor ecosystems. Soil microbial residues may not only affect soil organic carbon (SOC) pool but also impact SOC stability through soil aggregation. However, how soil nutrient availability and aggregate fractions affect microbial residues and the microbial residue contribution to SOC is still not well understood. We took advantage of a 10-year field fertilization experiment to investigate the effects of nutrient additions, soil aggregate fractions, and their interactions on the concentrations of soil microbial residues and their contribution to SOC accumulation in a tropical coastal forest. We found that continuous P addition greatly decreased the concentrations of microbial residues and their contribution to SOC, whereas N addition had no significant effect. The P-stimulated decreases in microbial residues and their contribution to SOC were presumably due to enhanced recycling of microbial residues via increased activity of residue-decomposing enzymes. The interactive effects between soil aggregate fraction and nutrient addition were not significant, suggesting a weak role of physical protection by soil aggregates in mediating microbial responses to altered soil nutrient availability. Our data suggest that the mechanisms driving microbial residue responses to increased N and P availability might be different, and the P-induced decrease in the contribution of microbial residues might be unfavorable for the stability of SOC in N-rich and P-poor tropical forests. Such information is critical for understanding the role of tropical forests in the global carbon cycle.
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Carbono , Suelo , Carbono/análisis , China , Ecosistema , Bosques , Nitrógeno/análisis , Fósforo , Microbiología del SueloRESUMEN
Wi-Fi network has an open nature so that it needs to face greater security risks compared to wired network. The MAC address represents the unique identifier of the device, and is easily obtained by an attacker. Therefore MAC address randomization is proposed to protect the privacy of devices in a Wi-Fi network. However, implicit identifiers are used by attackers to identify user's device, which can cause the leakage of user's privacy. We propose device identification based on 802.11ac probe request frames. Here, a detailed analysis on the effectiveness of 802.11ac fields is given and a novel device identification method based on deep learning whose average f1-score exceeds 99% is presented. With a purpose of preventing attackers from obtaining relevant information by the device identification method above, we design a novel defense mechanism based on stream cipher. In that case, the original content of probe request frame is hidden by encrypting probe request frames and construction of probe request is reserved to avoid the finding of attackers. This defense mechanism can effectively reduce the performance of the proposed device identification method whose average f1-score is below 30%. In general, our research on attack and defense mechanism can preserve device privacy better.
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Precursors and catalysts play vital roles in chemical reactions. Considerable efforts have been devoted to the investigation of catalysts for graphene growth by chemical vapor deposition in recent years. However, there has been little research on precursors because of a lack of innovation in term of creating a controllable feeding method. Herein, we present a novel sustained and controlled release approach, and develop a convenient, safe, and potentially scalable feeding system with the assistance of matrix materials and a simple portable feeder. As a result, a highly volatile liquid precursor can be fed accurately to grow large-area, uniform graphene films with optimal properties. This feeding approach will further benefit the synthesis of other two-dimensional materials from various precursors.
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In virtue of their distinctive superiorities, lithium-sulfur (Li-S) batteries were deemed as novel and potential energy storage equipment. However, the low actual energy density and rapid capacity fading are still hindering their practical applications. Herein, MXene-based Co, N-codoped porous carbon nanosheets (MCoNPCNSs) are first developed as sulfur hosts by in situ self-assembly of the bimetallic zeolite imidazole framework on Ti3C2Tx MXene nanosheets followed by calcining and etching treatments. Co, N codoping on the one hand highly enhances the adsorptivity to polysulfides and on the other hand significantly promotes the kinetics of sulfur cathodes. Therefore, the MCoNPCNSs/S-M-PP electrode achieves a high capacity of 1340.2 mA h g-1 in the first-cycle discharge process at 0.2 C and an exceptional capacity retention of 914.7 mA h g-1 after 1000 cycles at 1 C. Moreover, the integrated structure of the cathode and separator imparts the MCoNPCNSs/S-M-PP electrode a significantly elevated gravimetric energy density of 1211.8 W h kg-1. Therefore, the integrated MCoNPCNSs/S-M-PP electrode provides a delighted direction for constructing the potentially practical Li-S batteries.
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Lamellar membranes with well-defined 2D nanochannels show fast, selective permeation, but the underlying molecular transport mechanism is unexplored. Now, regular robust MXene Ti3 C2 Tx lamellar membranes are prepared, and the size and wettability of nanochannels are manipulated by chemically grafted hydrophilic (-NH2 ) or hydrophobic (-C6 H5 , -C12 H25 ) groups. These nanochannels have a sharp difference in mass transfer behavior. Hydrophilic nanochannels, in which polar molecules form orderly aligned aggregates along channel walls, impart ultrahigh permeance (>3000â L m-2 h-1 bar-1 ), which is more than three times higher than that in hydrophobic nanochannels with disordered molecular configuration. In contrast, nonpolar molecules with disordered configuration in both hydrophilic and hydrophobic nanochannels have comparable permeance. Two phenomenological transport models correlate the permeance with the mass transport mechanism of molecules that display ordered and disordered configuration.
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Three new species of the order Dorylaimida (de Man, 1876) Pearse, 1942 were identified and described. Paratylencholaimus sanshaensis gen. nov. sp. nov. from Hainan is proposed as a new member of the family Tylencholaimellidae Jairajpuri, 1964. Paratylencholaimus gen. nov. is close to Phellonema Thorne, 1964 and Goferus Jairajpuri & Ahmad, 1992 but can be differentiated mainly by having basal part of odontophore rod-like and without knobs, and basal part of pharynx expanded gradually. Tylencholaimus zhongshanensis sp. nov. from Guangdong and Dorylaimoides shapotouensis sp. nov. from the Ningxia Hui Autonomous Region are also described herein. Phylogenetic analyses based on the 18S rDNA and the D2-D3 region of the 28S rDNA support that the three new species are valid. The classifications of the families Tylencholaimellidae and Mydonomidae Thorne, 1964 are revised mainly based on the analysis of the morphology of odontostyle and odontophore. After these revisions, Paratylencholaiminae subfam. nov. including Paratylencholaimus gen. nov. and Goferus is proposed. Athernema and Agmodorus of Tylencholaimellidae are transferred into Mydonomidae, and the subfamily Athernematinae of Tylencholaimellidae is dismissed. The main characteristics of the family Mydonomidae and Tylencholaimellidae are revised. Keys to the genera of Mydomonidae and Tylencholaimellidae are included.
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Acid-base pairs hold great superiority in creating proton defects and facilitating proton transfer with less or no water. However, the existing acid-base complexes fail in assembling into ordered acid-base pairs and thus cannot always take full advantage of the acid-base synergetic effect. Herein, polymer quantum dots with inherent ordered acid-base pairs are utilized and anchored on dopamine-coated graphene oxide, thus forming into long-range conducting pathways. The resultant building blocks ( nPGO) are integrated in a sulfonated poly(ether ether ketone) matrix to fabricate composite membranes. The constructed long-range transfer highways with ordered acid-base pairs impart to the composite membrane significantly enhanced proton conduction ability. Under the hydrated state, the composite membrane attains 91% increase over the control membrane in conductivity, and the single-cell fuel based on the membrane achieves 71% promotion in maximum power density. Under anhydrous conditions, more striking augment in conduction is observed for the composite membrane, reaching 7.14 mS cm-1, almost 10 times of the control membrane value (0.78 mS cm-1). Remarkably, such anhydrous proton conduction performance is even comparable to that of the composite membrane impregnated with ionic liquids, which is hard to realize with conventional fillers. Collectively, these results endow composite membranes great potential for applications in hydrogen-based fuel cells, sensors, and catalysis.