A Guanidinobenzol-Rich Polymer Overcoming Cascade Delivery Barriers for CRISPR-Cas9 Genome Editing.

The efficient cytosolic delivery of the CRISPR-Cas9 machinery remains a challenge for genome editing. Herein, we performed ligand screening and identified a guanidinobenzol-rich polymer to overcome the cascade delivery barriers of CRISPR-Cas9 ribonucleoproteins (RNPs) for genome editing. RNPs were stably loaded into the polymeric nanoparticles (PGBA NPs) by their inherent affinity. The polymer facilitated rapid endosomal escape of RNPs via a dynamic multiple-step cascade process. Importantly, the incorporation of fluorescence in the polymer helps to identify the correlation between cellular uptake and editing efficiency, increasing the efficiency up to 70% from the initial 30% for the enrichment of edited cells. The PGBA NPs efficiently deliver RNPs for in vivo gene editing via both local and systemic injections and dramatically reduce PCSK9 level. These results indicate that PGBA NPs enable the cascade delivery of RNPs for genome editing, showing great promise in broadening the therapeutic potential of the CRISPR-Cas9 technique.

Genome-wide identification and stress response analysis of BcaCPK gene family in amphidiploid Brassica carinata.

BACKGROUND: Calcium-dependent protein kinases (CPKs) are crucial for recognizing and transmitting Ca2+ signals in plant cells, playing a vital role in growth, development, and stress response. This study aimed to identify and detect the potential roles of the CPK gene family in the amphidiploid Brassica carinata (BBCC, 2n = 34) using bioinformatics methods. RESULTS: Based on the published genomic information of B. carinata, a total of 123 CPK genes were identified, comprising 70 CPK genes on the B subgenome and 53 on the C subgenome. To further investigate the homologous evolutionary relationship between B. carinata and other plants, the phylogenetic tree was constructed using CPKs in B. carinata and Arabidopsis thaliana. The phylogenetic analysis classified 123 family members into four subfamilies, where gene members within the same subfamily exhibited similar conserved motifs. Each BcaCPK member possesses a core protein kinase domain and four EF-hand domains. Most of the BcaCPK genes contain 5 to 8 introns, and these 123 BcaCPK genes are unevenly distributed across 17 chromosomes. Among these BcaCPK genes, 120 replicated gene pairs were found, whereas only 8 genes were tandem duplication, suggesting that dispersed duplication mainly drove the family amplification. The results of the Ka/Ks analysis indicated that the CPK gene family of B. carinata was primarily underwent purification selection in evolutionary selection. The promoter region of most BcaCPK genes contained various stress-related cis-acting elements. qRT-PCR analysis of 12 selected CPK genes conducted under cadmium and salt stress at various points revealed distinct expression patterns among different family members in response to different stresses. Specifically, the expression levels of BcaCPK2.B01a, BcaCPK16.B02b, and BcaCPK26.B02 were down-regulated under both stresses, whereas the expression levels of other members were significantly up-regulated under at least one stress. CONCLUSION: This study systematically identified the BcaCPK gene family in B. carinata, which contributes to a better understanding the CPK genes in this species. The findings also serve as a reference for analyzing stress responses, particularly in relation to cadmium and salt stress in B. carinata.

Comprehensive genome-wide identification of Snf2 gene family and their expression profile under salt stress in six Brassica species of U's triangle model.

MAIN CONCLUSION: We comprehensively identified and analyzed the Snf2 gene family. Some Snf2 genes were involved in responding to salt stress based on the RNA-seq and qRT-PCR analysis. Sucrose nonfermenting 2 (Snf2) proteins are core components of chromatin remodeling complexes that not only alter DNA accessibility using the energy of ATP hydrolysis, but also play a critical regulatory role in growth, development, and stress response in eukaryotes. However, the comparative study of Snf2 gene family in the six Brassica species in U's triangle model remains unclear. Here, a total of 405 Snf2 genes were identified, comprising 53, 50, and 46 in the diploid progenitors: Brassica rapa (AA, 2n = 20), Brassica nigra (BB, 2n = 16), and Brassica oleracea (CC, 2n = 18), and 93, 91, and 72 in the allotetraploid: Brassica juncea (AABB, 2n = 36), Brassica napus (AACC, 2n = 38), and Brassica carinata (BBCC, 2n = 34), respectively. These genes were classified into six clades and further divided into 18 subfamilies based on their conserved motifs and domains. Intriguingly, these genes showed highly conserved chromosomal distributions and gene structures, indicating that few dynamic changes occurred during the polyploidization. The duplication modes of the six Brassica species were diverse, and the expansion of most Snf2 in Brassica occurred primarily through dispersed duplication (DSD) events. Additionally, the majority of Snf2 genes were under purifying selection during polyploidization, and some Snf2 genes were associated with various abiotic stresses. Both RNA-seq and qRT-PCR analysis showed that the expression of BnaSnf2 genes was significantly induced under salt stress, implying their involvement in salt tolerance response in Brassica species. The results provide a comprehensive understanding of the Snf2 genes in U's triangle model species, which will facilitate further functional analysis of the Snf2 genes in Brassica plants.

Root system architecture change in response to waterlogging stress in a 448 global collection of rapeseeds (Brassica napus L.).

MAIN CONCLUSIONS: A novel image-based screening method for precisely identifying genotypic variations in rapeseed RSA under waterlogging stress was developed. Five key root traits were confirmed as good indicators of waterlogging and might be employed in breeding, particularly when using the MFVW approach. Waterlogging is a vital environmental factor that has detrimental effects on the growth and development of rapeseed (Brassica napus L.). Plant roots suffer from hypoxia under waterlogging, which ultimately confers yield penalty. Therefore, it is crucially important to understand the genetic variation of root system architecture (RSA) in response to waterlogging stress to guide the selection of new tolerant cultivars with favorable roots. This research was conducted to investigate RSA traits using image-based screening techniques to better understand how RSA changes over time during waterlogging at the seedling stage. First, we performed a t-test by comparing the relative root trait value between four tolerant and four sensitive accessions. The most important root characteristics associated with waterlogging tolerance at 12 h are total root length (TRL), total root surface area (TRSA), total root volume (TRV), total number of tips (TNT), and total number of forks (TNF). The root structures of 448 rapeseed accessions with or without waterlogging showed notable genetic diversity, and all traits were generally restrained under waterlogging conditions, except for the total root average diameter. Additionally, according to the evaluation and integration analysis of 448 accessions, we identified that five traits, TRL, TRSA, TRV, TNT, and TNF, were the most reliable traits for screening waterlogging-tolerant accessions. Using analysis of the membership function value (MFVW) and D-value of the five selected traits, 25 extremely waterlogging-tolerant materials were screened out. Waterlogging significantly reduced RSA, inhibiting root growth compared to the control. Additionally, waterlogging increased lipid peroxidation, accompanied by a decrease in the activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT). This study effectively improves our understanding of the response of RSA to waterlogging. The image-based screening method developed in this study provides a new scientific guidance for quickly examining the basic RSA changes and precisely predicting waterlogging-tolerant rapeseed germplasms, thus expanding the genetic diversity of waterlogging-tolerant rapeseed germplasm available for breeding.

A novel real-time model for predicting acute kidney injury in critically ill patients within 12 hours.

BACKGROUND: A major challenge in prevention and early treatment of acute kidney injury (AKI) is the lack of high-performance predictors in critically ill patients. Therefore, we innovatively constructed U-AKIpredTM for predicting AKI in critically ill patients within 12 h of panel measurement. METHODS: The prospective cohort study included 680 patients in the training set and 249 patients in the validation set. After performing inclusion and exclusion criteria, 417 patients were enrolled in the training set and 164 patients were enrolled in the validation set finally. AKI was diagnosed by Kidney Disease Improving Global Outcomes (KDIGO) criteria. RESULTS: Twelve urinary kidney injury biomarkers (mALB, IgG, TRF, α1MG, NAG, NGAL, KIM-1, L-FABP, TIMP2, IGFBP7, CAF22 and IL-18) exhibited good predictive performance for AKI within 12 h in critically ill patients. U-AKIpredTM, combined with three crucial biomarkers (α1MG, L-FABP and IGFBP7) by multivariate logistic regression analysis, exhibited better predictive performance for AKI in critically ill patients within 12 h than the other twelve kidney injury biomarkers. The area under the curve (AUC) of the U-AKIpredTM, as a predictor of AKI within 12 h, was 0.802 (95% CI: 0.771-0.833, P < 0.001) in the training set and 0.844 (95% CI: 0.792-0.896, P < 0.001) in validation cohort. A nomogram based on the results of the training and validation sets of U-AKIpredTM was developed which showed optimal predictive performance for AKI. The fitting effect and prediction accuracy of U-AKIpredTM was evaluated by multiple statistical indicators. To provide a more flexible predictive tool, the dynamic nomogram (https://www.xsmartanalysis.com/model/U-AKIpredTM) was constructed using a web-calculator. Decision curve analysis (DCA) and a clinical impact curve were used to reveal that U-AKIpredTM with the three crucial biomarkers had a higher net benefit than these twelve kidney injury biomarkers respectively. The net reclassification index (NRI) and integrated discrimination index (IDI) were used to improve the significant risk reclassification of AKI compared with the 12 kidney injury biomarkers. The predictive efficiency of U-AKIpredTM was better than the NephroCheck® when testing for AKI and severe AKI. CONCLUSION: U-AKIpredTM is an excellent predictive model of AKI in critically ill patients within 12 h and would assist clinicians in identifying those at high risk of AKI.

Lipid analysis of breast milk and formula for preterm infants and the application and prospects of novel structural lipids - a comprehensive review.

Preterm infants, often characterized by lower birth weights and underdeveloped physiologies, necessitate specialized nutritional care. While breast milk stands as the ideal nutritional source, offering substantial energy through its fatty acid content to support the infants' growth and developmental needs, its usage might not always be feasible. Fatty acids in breast milk are critical for the development of these infants. In scenarios where breast milk is not an option, formula feeding becomes a necessary alternative. Thus, a comprehensive understanding of the fatty acid profiles in both breast milk and formulas is crucial for addressing the distinct nutritional requirements of preterm infants. This paper aims to summarize the effects of lipid composition, structure, and positioning in breast milk and formula on the growth and development of preterm infants. Furthermore, it explores recent advancements in the use of novel structural lipids in formulas, laying the groundwork for future innovations in formula design specifically catered to the needs of preterm infants.

The multivariate Bernoulli detector: change point estimation in discrete survival analysis.

Time-to-event data are often recorded on a discrete scale with multiple, competing risks as potential causes for the event. In this context, application of continuous survival analysis methods with a single risk suffers from biased estimation. Therefore, we propose the multivariate Bernoulli detector for competing risks with discrete times involving a multivariate change point model on the cause-specific baseline hazards. Through the prior on the number of change points and their location, we impose dependence between change points across risks, as well as allowing for data-driven learning of their number. Then, conditionally on these change points, a multivariate Bernoulli prior is used to infer which risks are involved. Focus of posterior inference is cause-specific hazard rates and dependence across risks. Such dependence is often present due to subject-specific changes across time that affect all risks. Full posterior inference is performed through a tailored local-global Markov chain Monte Carlo (MCMC) algorithm, which exploits a data augmentation trick and MCMC updates from nonconjugate Bayesian nonparametric methods. We illustrate our model in simulations and on ICU data, comparing its performance with existing approaches.

Tea polyphenol-engineered hybrid cellular nanovesicles for cancer immunotherapy and androgen deprivation therapy.

Androgen deprivation therapy (ADT) is a crucial and effective strategy for prostate cancer, while systemic administration may cause profound side effects on normal tissues. More importantly, the ADT can easily lead to resistance by involving the activation of NF-κB signaling pathway and high infiltration of M2 macrophages in tumor microenvironment (TME). Herein, we developed a biomimetic nanotherapeutic platform by deriving cell membrane nanovesicles from cancer cells and probiotics to yield the hybrid cellular nanovesicles (hNVs), loading flutamide (Flu) into the resulting hNVs, and finally modifying the hNVs@Flu with Epigallocatechin-3-gallate (EGCG). In this nanotherapeutic platform, the hNVs significantly improved the accumulation of hNVs@Flu-EGCG in tumor sites and reprogramed immunosuppressive M2 macrophages into antitumorigenic M1 macrophages, the Flu acted on androgen receptors and inhibited tumor proliferation, and the EGCG promoted apoptosis of prostate cancer cells by inhibiting the NF-κB pathway, thus synergistically stimulating the antitumor immunity and reducing the side effects and resistance of ADT. In a prostate cancer mouse model, the hNVs@Flu-EGCG significantly extended the lifespan of mice with tumors and led to an 81.78% reduction in tumor growth compared with the untreated group. Overall, the hNVs@Flu-EGCG are safe, modifiable, and effective, thus offering a promising platform for effective therapeutics of prostate cancer.

DNA Methylation Effects on Van der Woude Syndrome Phenotypic Variability.

OBJECTIVE: Van der Woude Syndrome (VWS) presents with combinations of lip pits (LP) and cleft lip and/or cleft palate (CL/P, CPO). VWS phenotypic heterogeneity even amongst relatives, suggests that epigenetic factors may act as modifiers. IRF6, causal for 70% of VWS cases, and TP63 interact in a regulatory loop coordinating epithelial proliferation and differentiation in palatogenesis. We hypothesize that differential DNA methylation within IRF6 and TP63 regulatory regions underlie VWS phenotypic discordance. METHODS: DNA methylation of CpG sites in IRF6 and TP63 promoters and in an IRF6 enhancer element was compared amongst blood or saliva DNA samples of 78 unrelated cases. Analyses were done separately for blood and saliva, within each sex and in combination, and to address cleft type (CL/P ± LP vs. CPO ± LP) and phenotypic severity (any cleft + LP vs. any cleft only). RESULTS: For cleft type, blood samples showed higher IRF6 and TP63 promoter methylation on males with CPO ± LP compared to CL/P ± LP and on individuals with CPO ± LP compared to those with CL/P ± LP, respectively. Saliva samples showed higher IRF6 enhancer methylation on individuals with CPO ± LP compared to CL/P ± LP and contrary to above, lower TP63 promoter methylation on CPO ± LP compared to CL/P ± LP. For phenotypic severity, blood samples showed no differences; however, saliva samples showed higher IRF6 promoter methylation in individuals with any cleft + LP compared to those without lip pits. CONCLUSION: We observed differential methylation in IRF6 and TP63 regulatory regions associated with cleft type and phenotypic severity, indicating that epigenetic changes in IRF6 and TP63 can contribute to phenotypic heterogeneity in VWS.

Comparisons between referred and non-referred patients to a university paediatric dental clinic.

BACKGROUND: Referrals of paediatric patients to a university clinic have been increasing over the last several years. AIM: To evaluate characteristics of referred and non-referred patients at the University of Iowa's Pediatric Dental Clinic (UIPDC). DESIGN: A retrospective chart review included dental records of 340 referred and 383 non-referred patients from July 1, 2015, to May 31, 2016 (n = 723). Age, distance to the clinic, size of the patient's community, insurance, number of teeth with decay, treatment needs, educational level of the provider, and presence of patient special health care needs were obtained. Descriptive statistics, bivariate analysis, and multivariable logistic regression were performed to analyze the outcomes (alpha = .05). RESULTS: Referred patients were more likely to live >60 miles away, live in a community of >75 000 people, have special health care needs, have caries/greater number of teeth with decay, need endodontic treatment, and were less likely to remain patients at the clinic (p < .0001). Referred patients were also more likely to need extractions (p = .0104), but less likely to need space maintenance/comprehensive orthodontic treatment (p = .0002). CONCLUSION: There was a difference in the complexity of patient treatment needs between referred and non-referred patients.

[Analysis and reflection on current situation of Chinese patent medicine for children in China].

This study took Chinese patent medicine for children included in Chinese Pharmacopoeia(2020 edition and the first supplement), Medicine Catalogue for National Basic Medical Insurance, Work Injury Insurance, and Maternity Insurance(2022 edition), and National Essential Medicines List(2018 edition) as the research objects, so as to sort out the distribution situation, characteristics, and the problems of Chinese patent medicine for children(including child-specific medicines, common medicines for children and adults, and discretionary medicines for children). According to statistics and summary, Chinese patent medicine for children is mainly administered orally, and the dosage forms are mostly traditional dosage forms, such as tablets, granules, capsules, and oral liquids, with mostly bitter or sweet taste. Diseases are mainly classified into pulmonary diseases and spleen and stomach diseases, and varieties of medication without Children's medication safety information or "still unclear" account for a relatively large proportion of the medicines. There are relatively few varieties of Chinese patent medicines for children, poor compliance of child-specific medication, lack of refinement of Chinese patent medicines for children dosage, and lack of information about safe use of medication. It is recommended to update and improve the instruction manuals in a timely manner, develop new varieties of Chinese patent medicine for children, and actively carry out post-marketing evaluation and clinical comprehensive evaluation of Chinese patent medicine for children, so as to provide a reference for the supplement and improvement of the instructions, the comprehensive improvement, the formulation of the catalogue, and the research and development of new Chinese patent medicine for children and ensure the use of medicines for children.

High C-reactive protein to lymphocyte ratio predicts mortality outcomes of patients with severe fever with thrombocytopenia syndrome: A multicenter study in China.

Severe fever with thrombocytopenia syndrome (SFTS) is a life-threatening infectious disease caused by the SFTS virus (SFTSV). This study aimed to evaluate the predictive power of C-reactive protein to lymphocyte ratio (CLR) and establish an early-warning model for SFTS mortality. We retrospectively analyzed hospitalized SFTS patients in six clinical centers from May 2011 to 2022. The efficacy of CLR prediction was evaluated by the receiver operating characteristic (ROC) analysis. A nomogram was established and validated. Eight hundred and eighty-two SFTS patients (median age 64 years, 48.5% male) were enrolled in this study, with a mortality rate of 17.8%. The area under the ROC curve (AUC) of CLR was 0.878 (95% confidence interval [CI]: 0.850-0.903, p < 0.001), which demonstrates high predictive strength. The least absolute shrinkage and selection operator regression selected seven potential predictors. Multivariate logistic regression analysis determined three independent risk factors, including CLR, to construct the nomogram. The performance of the nomogram displayed excellent discrimination and calibration, with significant net benefits in clinical uses. CLR is a brand-new predictor for SFTS mortality. The nomogram based on CLR can serve as a convenient tool for physicians to identify critical SFTS cases in clinical practice.

Addendum: The antibody aducanumab reduces Aß plaques in Alzheimer's disease.

This corrects the article DOI: 10.1038/nature21361.

Endocrine-disrupting chemicals and autoimmune diseases.

Endocrine-disrupting chemicals (EDCs) widely exist in people's production and life which have great potential to damage human and animal health. Over the past few decades, growing attention has been paid to the impact of EDCs on human health, as well as immune system. So far, researchers have proved that EDCs (such as bisphenol A (BPA), phthalate, tetrachlorodibenzodioxin (TCDD), etc.) affect human immune function and promotes the occurrence and development of autoimmune diseases (ADs). Therefore, in order to better understand how EDCs affect ADs, we summarized the current knowledge about the impact of EDCs on ADs, and elaborated the potential mechanism of the impact of EDCs on ADs in this review.

Decoy nanoparticles protect against COVID-19 by concurrently adsorbing viruses and inflammatory cytokines.

The COVID-19 pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has highlighted the urgent need to rapidly develop therapeutic strategies for such emerging viruses without effective vaccines or drugs. Here, we report a decoy nanoparticle against COVID-19 through a powerful two-step neutralization approach: virus neutralization in the first step followed by cytokine neutralization in the second step. The nanodecoy, made by fusing cellular membrane nanovesicles derived from human monocytes and genetically engineered cells stably expressing angiotensin converting enzyme II (ACE2) receptors, possesses an antigenic exterior the same as source cells. By competing with host cells for virus binding, these nanodecoys effectively protect host cells from the infection of pseudoviruses and authentic SARS-CoV-2. Moreover, relying on abundant cytokine receptors on the surface, the nanodecoys efficiently bind and neutralize inflammatory cytokines including interleukin 6 (IL-6) and granulocyte-macrophage colony-stimulating factor (GM-CSF), and significantly suppress immune disorder and lung injury in an acute pneumonia mouse model. Our work presents a simple, safe, and robust antiviral nanotechnology for ongoing COVID-19 and future potential epidemics.

Optimization of medium composition of Lactobacillus plantarum Y44 using Plackett-Burman and Box-Behnken designs.

The biomass of Lactobacillus strains depends on the culture media and culture conditions. The purpose of this study was to optimize the culture medium composition and culture conditions of Lactobacillus plantarum Y44 to improve its biomass. The utilization of different carbon sources and nitrogen sources by L. plantarum Y44 was assessed by single factor experiment to screen out the economical carbon and nitrogen sources for L. plantarum Y44 growth. Through optimization experiments, the optimized culture medium for L. plantarum Y44 growth consists of soybean peptone 44.1 g/L, yeast extract 22.1 g/L, sucrose 35.6 g/L, hydrogen diamine citrate 2 g/L, anhydrous sodium acetate 8.5 g/L, dipotassium hydrogen phosphate 4 g/L, Tween-80 2 mL/L, manganese sulfate 0.25 g/L, and magnesium sulfate 0.58 g/L, and the initial pH 6.7. The concentration of viable bacteria cells of L. plantarum Y44 culturing in the optimized medium at 37 °C for 16 h was up to 3.363 × 1010 CFU/mL, as 6.11 times higher than that in the MRS medium.

CPP-ACP paste's effect on salivary conditions in patients with removable dentures.

PURPOSE: Older adults with removable dentures experience high rates of both caries (when the natural dentition remains) and salivary gland dysfunction. While many commercial dental therapeutic agents target these two interrelated problems, none have been labeled for use on the fitting surface of removable dentures. Off-label use of MI Paste (GC America, Alsip, IL), a dental therapeutic containing casein-phosphopeptide-amorphous-calcium-phosphate (CPP-ACP), was investigated following its application to the fitting surface of complete denture(s) with subsequent effects on salivary conditions measured. MATERIALS AND METHODS: Salivary flow rate and pH were recorded at baseline and 15 min following the application of 1 mL of CPP-ACP paste to the fitting surface of each participant's denture through whole saliva collection. To assess buffering capacity, equivalent volumes of 0.01 M lactic acid were added to the collected saliva samples, and pH reduction was measured. Comparisons of salivary parameters between baseline and post-CPP-ACP paste application and between subjects with and without self-reported xerostomia were conducted using a paired-sample t-test, Wilcoxon signed-rank test, or two-sample t-test as appropriate. RESULTS: Of the 28 participants (mean age = 70.3 ± 13.7 years, 17 males), 11 reported xerostomia. CPP-ACP-paste application was associated with decreased pH reduction during acid challenge compared to baseline (0.95 ± 0.24 vs. 1.54 ± 0.53, p < 0.001), and a higher final pH following acid challenge (5.93 ± 0.34 vs. 5.40 ± 0.66, p < 0.001). While the flow rates observed at post-CPP-ACP paste application were greater than those at baseline, the difference was not statistically significant (0.67 ± 0.44 mL/min vs. 0.55 ± 0.34 mL/min, p = 0.053). No significant differences were found in any salivary parameters between participants with or without self-reports of xerostomia. CONCLUSIONS: The findings highlight potential positive effects on salivary conditions following the application of the CPP-ACP-containing product, MI Paste, to the fitting surface of a removable complete denture as a potential caries-risk-management tool when natural dentition remains. Determining the caries-preventive clinical significance will require longer-term trials.

Microfluidics-Assisted Fluorescence Mapping of DNA Phosphorothioation.

As the key player of a new restriction modification system, DNA phosphorothioate (PT) modification, which swaps oxygen for sulfur on the DNA backbone, protects the bacterial host from foreign DNA invasion. The identification of PT sites helps us understand its physiological defense mechanisms, but accurately quantifying this dynamic modification remains a challenge. Herein, we report a simple quantitative analysis method for optical mapping of PT sites in the single bacterial genome. DNA molecules are fully stretched and immobilized in a microfluidic chip by capillary flow and electrostatic interactions, improving the labeling efficiency by maximizing exposure of PT sites on DNA while avoiding DNA loss and damage. After screening 116 candidates, we identified a bifunctional chemical compound, iodoacetyl-polyethylene glycol-biotin, that can noninvasively and selectively biotinylate PT sites, enabling further labeling with streptavidin fluorescent nanoprobes. With this method, PT sites in PT+ DNA can be easily detected by fluorescence, while almost no detectable ones were found in PT- DNA, achieving real-time visualization of PT sites on a single DNA molecule. Collectively, this facile genome-wide PT site detection method directly characterizes the distribution and frequency of DNA modification, facilitating a better understanding of its modification mechanism that can be potentially extended to label DNAs in different species.

A van der Waals Integrated Damage-Free Memristor Based on Layered 2D Hexagonal Boron Nitride.

2D materials with intriguing properties have been widely used in optoelectronics. However, electronic devices suffered from structural damage due to the ultrathin materials and uncontrolled defects at interfaces upon metallization, which hindered the development of reliable devices. Here, a damage-free Au/h-BN/Au memristor is reported using a clean, water-assisted metal transfer approach by physically assembling Au electrodes onto the layered h-BN which minimized the structural damage and undesired interfacial defects. The memristors demonstrate significantly improved performance with the coexistence of nonpolar and threshold switching as well as tunable current levels by controlling the compliance current, compared with devices with evaporated contacts. The devices integrated into an array show suppressed sneak path current and can work as both logic gates and latches to implement logic operations allowing in-memory computing. Cross-sectional scanning transmission electron microscopy analysis validates the feasibility of this nondestructive metal integration approach, the crucial role of high-quality atomically sharp interface in resistive switching, and a direct observation of percolation path. The underlying mechanism of boron vacancies-assisted transport is further supported experimentally by conductive atomic force microscopy free from process-induced damage, and theoretically by ab initio simulations.

Effects of fluid slippage on pressure-driven electrokinetic energy conversion in conical nanochannels.

The effects of fluid slippage on the pressure-driven electrokinetic energy conversion in conical nanochannels are systematically investigated in this paper. We present a multiphysical model that couples the Planck-Nernst-Poisson equations and the Navier-Stokes equation with a Navier slip condition to fulfill this purpose. We systematically look into the variation of various performance indicators of electrokinetic energy conversion, for example, streaming current, streaming potential, generation power, energy conversion efficiency, regulation parameter, and enchantment ratio, with the conicity of nanochannels and the slip length for two pressure differences of the same magnitude but opposite directions. Particularly, enhancement ratios related to streaming current, streaming potential, generation power, and energy conversion efficiency are defined to comprehensively measure the enhancement of the performance of electrokinetic energy conversion due to the slip length. The results demonstrate that a combination of large slip length and small conicity enhances the electrokinetic energy conversion performance significantly. Furthermore, the fluid slippage-induced enhancement of the electrokinetic energy conversion in the backward pressure difference mode is stronger than that in the forward pressure difference mode. Our results provide design and operation guidelines for pressure-driven electrokinetic energy conversion devices.