Recent progresses in the cyclization and oxidation of polyketide biosynthesis.

Polyketides represent an important class of natural products, renowned for their intricate structures and diverse biological activities. In contrast to common fatty acids, polyketides possess relatively more rigid carbon skeletons, more complex ring systems, and chiral centers. These structural features are primarily achieved through distinctive enzymatic cyclizations and oxidations as tailoring steps. In this opinion, we discuss the recent progress in deciphering the mechanisms of cyclization and oxidation within polyketide biosynthesis. By shedding light on these enzymatic processes, this article seeks to motivate the community to unravel the remaining mysteries surrounding cyclase and oxidase functionalities and to explore novel polyketide natural products through genome mining.

An ultraflexible energy harvesting-storage system for wearable applications.

The swift progress in wearable technology has accentuated the need for flexible power systems. Such systems are anticipated to exhibit high efficiency, robust durability, consistent power output, and the potential for effortless integration. Integrating ultraflexible energy harvesters and energy storage devices to form an autonomous, efficient, and mechanically compliant power system remains a significant challenge. In this work, we report a 90 µm-thick energy harvesting and storage system (FEHSS) consisting of high-performance organic photovoltaics and zinc-ion batteries within an ultraflexible configuration. With a power conversion efficiency surpassing 16%, power output exceeding 10 mW cm-2, and an energy density beyond 5.82 mWh cm-2, the FEHSS can be tailored to meet the power demands of wearable sensors and gadgets. Without cumbersome and rigid components, FEHSS shows immense potential as a versatile power source to advance wearable electronics and contribute toward a sustainable future.

A hot-emitter transistor based on stimulated emission of heated carriers.

Hot-carrier transistors are a class of devices that leverage the excess kinetic energy of carriers. Unlike regular transistors, which rely on steady-state carrier transport, hot-carrier transistors modulate carriers to high-energy states, resulting in enhanced device speed and functionality. These characteristics are essential for applications that demand rapid switching and high-frequency operations, such as advanced telecommunications and cutting-edge computing technologies1-5. However, the traditional mechanisms of hot-carrier generation are either carrier injection6-11 or acceleration12,13, which limit device performance in terms of power consumption and negative differential resistance14-17. Mixed-dimensional devices, which combine bulk and low-dimensional materials, can offer different mechanisms for hot-carrier generation by leveraging the diverse potential barriers formed by energy-band combinations18-21. Here we report a hot-emitter transistor based on double mixed-dimensional graphene/germanium Schottky junctions that uses stimulated emission of heated carriers to achieve a subthreshold swing lower than 1 millivolt per decade beyond the Boltzmann limit and a negative differential resistance with a peak-to-valley current ratio greater than 100 at room temperature. Multi-valued logic with a high inverter gain and reconfigurable logic states are further demonstrated. This work reports a multifunctional hot-emitter transistor with significant potential for low-power and negative-differential-resistance applications, marking a promising advancement for the post-Moore era.

Circulating Lipid Profiles Associated With Resistance to Androgen Deprivation Therapy in Localized Prostate Cancer.

PURPOSE: Intense androgen deprivation therapy (ADT) with androgen receptor pathway inhibitors (ARPIs) before radical prostatectomy (RP) produced favorable pathologic responses in approximately 20% of patients. The molecular reason for the low rate of response remains unclear. Lipid metabolism is known to influence androgen receptor signaling and ARPI efficacy. The aim of the study was to identify circulating lipid profiles associated with ADT/ARPI resistance in localized prostate cancer. MATERIALS AND METHODS: Two independent experimental approaches were used. Experiment 1: Post hoc analysis of the association between plasma lipidomic profiles and ADT/ARPI response was performed on patients (n = 104) from two phase II trials of neoadjuvant ADT/ARPI. Response to ADT/ARPI was defined by pathologic response. Experiment 2: Patient-derived tumor explants from RP (n = 105) were cultured in enzalutamide for 48 hours. Explant response to enzalutamide was evaluated against pre-RP plasma lipidomic profiles (n = 105) and prostate tissue lipidomic profiles (n = 36). Response was defined by Ki67 (cell proliferation marker) fold difference between enzalutamide and vehicle-treated explants. In both experiments, associations between lipid profiles and ADT/ARPI response were analyzed by latent class analysis. RESULTS: Pretreatment plasma lipid profiles classified each experimental cohort into two groups with differences in ADT/ARPI response rates. The response rates of the groups were 9.6% versus 29% in experiment 1 (chi-squared test P = .012) and 49% versus 70% in experiment 2 (chi-squared test P = .037). In both experiments, the group with a higher incidence of ADT/ARPI resistance had higher plasma levels of sphingomyelin, glycosylceramides, free fatty acids, acylcarnitines, cholesterol esters, and alkyl/alkenyl-phosphatidylcholine and lower plasma levels of triacylglycerols, diacylglycerols, and phosphoethanolamine (t-test P < .05). CONCLUSION: Pretreatment circulating lipid profiles are associated with ADT/ARPI resistance in localized cancer in both human cohorts and explant models.

Forensic bone age assessment of hand and wrist joint MRI images in Chinese han male adolescents based on deep convolutional neural networks.

In Chinese criminal law, the ages of 12, 14, 16, and 18 years old play a significant role in the determination of criminal responsibility. In this study, we developed an epiphyseal grading system based on magnetic resonance image (MRI) of the hand and wrist for the Chinese Han population and explored the feasibility of employing deep learning techniques for bone age assessment based on MRI of the hand and wrist. This study selected 282 Chinese Han Chinese males aged 6.0-21.0 years old. In the course of our study, we proposed a novel deep learning model for extracting and enhancing MRI hand and wrist bone features to enhance the prediction of target MRI hand and wrist bone age and achieve precise classification of the target MRI and regression of bone age. The evaluation metric for the classification model including precision, specificity, sensitivity, and accuracy, while the evaluation metrics chosen for the regression model are MAE. The epiphyseal grading was used as a supervised method, which effectively solved the problem of unbalanced sample distribution, and the two experts showed strong consistency in the epiphyseal plate grading process. In the classification results, the accuracy in distinguishing between adults and minors was 91.1%, and the lowest accuracy in the three minor classifications (12, 14, and 16 years of age) was 94.6%, 91.1% and 96.4%, respectively. The MAE of the regression results was 1.24 years. In conclusion, the deep learning model proposed enabled the age assessment of hand and wrist bones based on MRI.

Relationship between non-alcoholic fatty liver and progressive fibrosis and serum 25-hydroxy vitamin D in patients with type 2 diabetes mellitus.

OBJECTIVE: We aimed to analyze the relationship between non-alcoholic fatty liver and progressive fibrosis and serum 25-hydroxy vitamin D (25(OH)D) in patients with type 2 diabetes mellitus. METHODS: A total of 184 patients with T2DM who were hospitalized in the Department of Endocrinology of the ShiDong Clinical Hospital between January 2023 and June 2023 were selected. We compared review of anthropometric, biochemical, and inflammatory parameters and non-invasive scores between groups defined by ultrasound NAFLD severity grades.We determine the correlation between 25(OH)D and FLI and FIB-4 scores, respectively. RESULTS: Statistically significant differences were seen between BMI, WC, C-peptide levels, FPG, ALT, serum 25(OH)D, TC, HDL, lumbar spine bone density, FLI, and FIB-4 in different degrees of NAFLD. Multivariate logistic regression analysis showed that 25(OH)D (OR = 1.26, p = 0.001), age (OR = 0.93, P < 0.001) and BMI (OR = 1.04, p = 0.007) were independent predictors of NAFLD in patients with T2DM. CONCLUSIONS: This study revealed the correlation between serum 25(OH)D levels and NAFLD in patients with T2DM. We also demonstrated that serum 25(OH)D levels were negatively correlated with FLI/FIB-4 levels in patients with T2DM with NAFLD, suggesting that vitamin D deficiency may promote hepatic fibrosis progression in T2DM with NAFLD.

Identification and bioactivity evaluation of twelve previously undescribed depsidone derivatives from Garcinia oligantha.

Phytochemical studies on the leaves and twigs of Garcinia oligantha Merr. led to the isolation of twelve previously undescribed depsidone derivatives (oliganthdepsidones A-L, 1-12). Their structures were elucidated by extensive spectroscopic analysis including 1H and 13C NMR, HSQC, HMBC and NOESY along with HRESIMS. The structures of oliganthdepsidones G and J were finally determined using DFT-NMR chemical shift calculations and DP4+ methods. Cytotoxicity test in four human cancer cell lines indicated that oliganthdepsidone F had relatively strong cytotoxic effect against A375 (melanoma), A549 (lung cancer), HepG2 (liver cancer), and MCF-7 (breast cancer) cell lines with IC50 of 18.71, 15.44, 10.92, and 15.90 µM, respectively. The dose- and time-dependent antiproliferative effects of oliganthdepsidone F on these cell lines were also observed by CCK-8 test. As determined by fluorescent microscopy and flow cytometry in these cell lines, oliganthdepsidone F could promote cell apoptosis, leading to the inhibition of cell proliferation. The results of wound healing assay and transwell assay showed that oliganthdepsidone F could inhibit the migration and invasion of A549 and MCF-7 cell lines in a concentration-dependent manner.

Electricity generated by upstream proton diffusion in two-dimensional nanochannels.

The movement of ions along the pressure-driven water flow in narrow channels, known as downstream ionic transport, has been observed since 1859 to induce a streaming potential and has enabled the creation of various hydrovoltaic devices. In contrast, here we demonstrate that proton movement opposing the water flow in two-dimensional nanochannels of MXene/poly(vinyl alcohol) films, termed upstream proton diffusion, can also generate electricity. The infiltrated water into the channel causes the dissociation of protons from functional groups on the channel surface, resulting in a high proton concentration inside the channel that drives the upstream proton diffusion. Combined with the particularly sluggish water diffusion in the channels, a small water droplet of 5 µl can generate a voltage of ~400 mV for over 330 min. Benefiting from the ultrathin and flexible nature of the film, a wearable device is built for collecting energy from human skin sweat.

Isolation and biological activity of six new polyketide and terpenoid derivatives from Neopestalotiopsis Clavispora AL01.

A fungus strain, Neopestalotiopsis clavispora AL01, was isolated from the leaf spot of the plant Phoenix dactylifera. Further chemical investigation of the fermentation extract of this strain afforded six new secondary metabolites (1-6), along with 11 known compounds (7-17) which included a new natural compound (7). Their structures were determined by extensive spectroscopic analysis including one-and two-dimensional (1D and 2D) NMR spectroscopy, high-resolution electrospray ionization mass spectrometry (HRESIMS), and ECD and NMR calculations. All compounds were evaluated for their phytotoxic activities. Among them, compounds 10, 12 and 13 exhibited phytotoxic activities against Nicotiana tabacum. Compound 3 exhibited weak antibacterial activity against methicillin-resistant Staphylococcus aureus, Micrococcus luteus and Vibrio harveyi. Taken collectively, these findings establish a solid research foundation for future investigations on bioactive natural products derived from phytopathogenic fungi.

The volatile oil of Hyssopus cuspidatus Boriss. (HVO) ameliorates OVA-induced allergic asthma via inhibiting PI3K/Akt/JNK/P38 signaling pathway and maintaining airway barrier integrity.

ETHNOPHARMACOLOGICAL RELEVANCE: Hyssopus cuspidatus Boriss., a classic Uyghur medicine, is used to treat inflammatory lung diseases such as asthma. But the therapeutic effect and mechanism of the volatile oil of Hyssopus cuspidatus Boriss.(HVO) in asthma therapy remain unclear. AIM OF THE STUDY: We aim to characterize the constituents of HVO, investigate the therapeutic effect in OVA-induced allergic asthmatic mice and further explore the molecular mechanism. MATERIALS AND METHODS: In this study, we applied two-dimensional gas chromatography quadrupole time-of-flight mass spectrometry (GC × GC-QTOF MS) to identify the ingredients of HVO. We established OVA-induced asthmatic model to investigate the therapeutic effect of HVO. To further explore the potential molecular pathways, we used network pharmacology approach to perform GO and KEGG pathways enrichment, and then built an ingredient-target-pathway network to identify key molecular pathways. Finally, LPS-induced RAW 264.7 macrophages and OVA-induced asthmatic model were used to validate the potential signaling pathways. RESULTS: GC × GC-QTOF MS analysis revealed the presence of 123 compounds of HVO. The sesquiterpenes and monoterpenes are the main constituents. The in vivo study indicated that HVO suppressed OVA-induced eosinophilic infiltration in lung tissues, inhibited the elevation of IgE, IL-4, IL-5, and IL-13 levels, downregulated the expressions of phosphorylated PI3K, Akt, JNK and P38, and maintained epithelial barrier integrity via reducing the degradation of occludin, Zo-1, Zo-2, and E-cadherin. The in vitro study also revealed an inhibition of NO release and downregulation of phosphorylated PI3K, Akt, JNK and P38 levels. CONCLUSION: HVO alleviates airway inflammation in OVA-induced asthmatic mice by inhibiting PI3K/Akt/JNK/P38 signaling pathway and maintaining airway barrier integrity via reducing the degradation of occludin, Zo-1, Zo-2, and E-cadherin.

Analysis of differences in physicochemical properties of different sorghum varieties and their influence on the selection of raw materials for winemaking.

Sorghum is one of the oldest crops in the world, an important grain crop in northern China, and a major raw material in the liquor-brewing industry. The physicochemical properties, cooking characteristics, and starch quality of sorghum seeds considerably affect the liquor-brewing process.To select suitable sorghums for liquor brewing and to determine the cooking characteristics and starch physicochemical properties of different sorghum varieties, 30 types of sorghum were used in this study, and their compositions were compared; six types of sorghum were further studied for their cooking quality and starch physicochemical and pasting characteristics. Gas chromatography time of flight mass spectrometry was used to analyse the cooking aroma of sorghum seeds. Additionally, scanning electron microscopy, a rapid visco analyser, and a differential calorimetric scanner were used to analyse the microstructure of sorghum starch, starch pasting characteristics, and thermodynamic properties, respectively. The results revealed that the water absorption and saccharification forces of glutinous sorghum were higher than those of japonica sorghum and that the aroma substances were significantly different. Glutinous sorghum starch had high crystallinity, freeze-thaw stability, and enthalpy, thus indicating its structural stability. This study provides a theoretical basis for the selection of wine raw materials in the future.

Element Screening of High-Entropy Silicon Anodes for Superior Li-Storage Performance of Li-Ion Batteries.

The high-entropy silicon anodes are attractive for enhancing electronic and Li-ionic conductivity while mitigating volume effects for advanced Li-ion batteries (LIBs), but are plagued by the complicated elements screening process. Inspired by the resemblances in the structure between sphalerite and diamond, we have selected sphalerite-structured SiP with metallic conductivity as the parent phase for exploring the element screening of high-entropy silicon-based anodes. The inclusion of the Zn in the sphalerite structure is crucial for improving the structural stability and Li-storage capacity. Within the same group, Li-storage performance is significantly improved with increasing atomic number in the order of BZnSiP3 < AlZnSiP3 < GaZnSiP3 < InZnSiP3. Thus, InZnSiP3-based electrodes achieved a high capacity of 719 mA h g-1 even after 1,500 cycles at 2,000 mA g-1, and a high-rate capacity of 725 mA h g-1 at 10,000 mA g-1, owing to its superior lithium-ion affinity, faster electronic conduction and lithium-ion diffusion, higher Li-storage capacity and reversibility, and mechanical integrity than others. Additionally, the incorporation of elements with larger atomic sizes leads to greater lattice distortion and more defects, further facilitating mass and charge transport. Following these screening rules, high-entropy disordered-cation silicon-based compounds such as GaCuSnInZnSiP6, GaCu(or Sn)InZnSiP5, and CuSnInZnSiP5, as well as high-entropy compounds with mixed-cation and -anion compositions, such as InZnSiPSeTe and InZnSiP2Se(or Te), are synthesized, demonstrating improved Li-storage performance with metallic conductivity. The phase formation mechanism of these compounds is attributed to the negative formation energies arising from elevated entropy.

Development and validation of a circulating tumor DNA-based optimization-prediction model for short-term postoperative recurrence of endometrial cancer.

BACKGROUND: Endometrial cancer (EC) is a common gynecological malignancy that typically requires prompt surgical intervention; however, the advantage of surgical management is limited by the high postoperative recurrence rates and adverse outcomes. Previous studies have highlighted the prognostic potential of circulating tumor DNA (ctDNA) monitoring for minimal residual disease in patients with EC. AIM: To develop and validate an optimized ctDNA-based model for predicting short-term postoperative EC recurrence. METHODS: We retrospectively analyzed 294 EC patients treated surgically from 2015-2019 to devise a short-term recurrence prediction model, which was validated on 143 EC patients operated between 2020 and 2021. Prognostic factors were identified using univariate Cox, Lasso, and multivariate Cox regressions. A nomogram was created to predict the 1, 1.5, and 2-year recurrence-free survival (RFS). Model performance was assessed via receiver operating characteristic (ROC), calibration, and decision curve analyses (DCA), leading to a recurrence risk stratification system. RESULTS: Based on the regression analysis and the nomogram created, patients with postoperative ctDNA-negativity, postoperative carcinoembryonic antigen 125 (CA125) levels of < 19 U/mL, and grade G1 tumors had improved RFS after surgery. The nomogram's efficacy for recurrence prediction was confirmed through ROC analysis, calibration curves, and DCA methods, highlighting its high accuracy and clinical utility. Furthermore, using the nomogram, the patients were successfully classified into three risk subgroups. CONCLUSION: The nomogram accurately predicted RFS after EC surgery at 1, 1.5, and 2 years. This model will help clinicians personalize treatments, stratify risks, and enhance clinical outcomes for patients with EC.

Developing a Nomogram for Predicting Colorectal Cancer and Its Precancerous Lesions Based on Data from Three Non-Invasive Screening Tools, APCS, FIT, and sDNA.

Purpose: This study aimed to develop and validate a nomogram for predicting positive colonoscopy results using the data from non-invasive screening strategies. Methods: The volunteers participated in primary colorectal cancer (CRC) screenings using Asia-Pacific colorectal screening (APCS) scoring, faecal immunochemical testing (FIT) and stool deoxyribonucleic acid (sDNA) testing and underwent a colonoscopy. The positive colonoscopy results included CRC, advanced adenoma (AA), high-grade intraepithelial neoplasia (HGIN), and low-grade intraepithelial neoplasia (LGIN). The enrolled participants were randomly selected for training and validation sets in a 7:3 ratio. A model for predicting positive colonoscopy results was virtualized by the nomogram using logistic regression analysis. Results: Among the 179 enrolled participants, 125 were assigned to training set, while 54 were assigned to validation set. After multivariable logistic regression was done, APCS score, FIT result, and sDNA result were all identified as the predictors for positive colonoscopy results. A model that incorporated the above independent predictors was developed and presented as a nomogram. The C-index of the nomogram in the validation set was 0.768 (95% CI, 0.644-0.891). The calibration curve demonstrated a good agreement between prediction and observation. The decision curve analysis (DCA) curve showed that the model achieved a net benefit across all threshold probabilities. The AUC of the prediction model for predicting positive colonoscopy results was much higher than that of the FIT + sDNA test scheme. Conclusion: The nomogram for predicting positive colonoscopy results was successfully developed based on 3 non-invasive screening tools (APCS scoring, FIT and sDNA test).

Strategies and Challenges of Microbiota Regulation in Baijiu Brewing.

The traditional Chinese Baijiu brewing process utilizes natural inoculation and open fermentation. The microbial composition and abundance in the microecology of Baijiu brewing often exhibit unstable characteristics, which directly results in fluctuations in Baijiu quality. The microbiota plays a crucial role in determining the quality of Baijiu. Analyzing the driving effect of technology and raw materials on microorganisms. Elucidating the source of core microorganisms and interactions between microorganisms, and finally utilizing single or multiple microorganisms to regulate and intensify the Baijiu fermentation process is an important way to achieve high efficiency and stability in the production of Baijiu. This paper provides a systematic review of the composition and sources of microbiota at different brewing stages. It also analyzes the relationship between raw materials, brewing processes, and brewing microbiota, as well as the steps involved in the implementation of brewing microbiota regulation strategies. In addition, this paper considers the feasibility of using Baijiu flavor as a guide for Baijiu brewing regulation by synthesizing the microbiota, and the challenges involved. This paper is a guide for flavor regulation and quality assurance of Baijiu and also suggests new research directions for regulatory strategies for other fermented foods.

Unusually high thermal conductivity in suspended monolayer MoSi2N4.

Two-dimensional semiconductors with high thermal conductivity and charge carrier mobility are of great importance for next-generation electronic and optoelectronic devices. However, constrained by the long-held Slack's criteria, the reported two-dimensional semiconductors such as monolayers of MoS2, WS2, MoSe2, WSe2 and black phosphorus suffer from much lower thermal conductivity than silicon (~142 W·m-1·K-1) because of the complex crystal structure, large average atomic mass and relatively weak chemical bonds. Despite the more complex crystal structure, the recently emerging monolayer MoSi2N4 semiconductor has been predicted to have high thermal conductivity and charge carrier mobility simultaneously. In this work, using a noncontact optothermal Raman technique, we experimentally measure a high thermal conductivity of ~173 W·m-1·K-1 at room temperature for suspended monolayer MoSi2N4 grown by chemical vapor deposition. First-principles calculations reveal that such unusually high thermal conductivity benefits from the high Debye temperature and small Grüneisen parameter of MoSi2N4, both of which are strongly dependent on the high Young's modulus induced by the outmost Si-N bilayers. Our study not only establishes monolayer MoSi2N4 as a benchmark 2D semiconductor for next-generation electronic and optoelectronic devices, but also provides an insight into the design of 2D materials for efficient heat conduction.

Management of refined and personalized newborn blood specimen collection.

Background: Iatrogenic blood loss is an important cause of neonatal anemia. In this study, a spreadsheet tool was developed to reduce blood collection, providing a new idea for the prevention of iatrogenic blood loss in newborns. Methods: Based on hematocrit, minimum test volume and dead volume, a new tool was to calculate the minimum blood collection volume and the number of containers required for the test portfolio. We collected data from October 2022 to October 2023 from Xiamen Maternal and Child Health Hospital for analysis and validation. Results: During this year, there were 16,434 patients and 13,696 plasma/serological samples in the neonatology department. Among them, there were 8 test combinations of greater than 1%, and 9490 samples in total. According to the hospital manual, the recommended amount of blood collection is 27,534 ml and 9490 containers. Through the analysis of this tool, total blood collection was 8864.77 ml, marked qnantity of upward containers (closest level to the calculated blood collection volume) was 10301 ml, and the amount of containers was 8835, which decreased by 67.8%, 62.58% and 6.9% respectively. Besides, if the hematocrit information cannot be obtained in advance and the high hematocrit is calculated as 0.8, the recommended amount of blood collection is 14334.3 ml, and the marked amount of the upward container markering is 17340 ml, decreasing by 47.9% and 37.02% respectively. Conclusion: We have developed an auxiliary tool that can manage neonatal blood specimen collection in a fine and personalized way and can be applied among different laboratory instruments by parameters modification.

Application of Medical Statistical and Machine Learning Methods in the Age Estimation of Living Individuals.

In the study of age estimation in living individuals, a lot of data needs to be analyzed by mathematical statistics, and reasonable medical statistical methods play an important role in data design and analysis. The selection of accurate and appropriate statistical methods is one of the key factors affecting the quality of research results. This paper reviews the principles and applicable principles of the commonly used medical statistical methods such as descriptive statistics, difference analysis, consistency test and multivariate statistical analysis, as well as machine learning methods such as shallow learning and deep learning in the age estimation research of living individuals, and summarizes the relevance and application prospects between medical statistical methods and machine learning methods. This paper aims to provide technical guidance for the age estimation research of living individuals to obtain more scientific and accurate results.

Molecular dynamics (MD) study to predict performances of a novel hexanitrohexaazaisowurtzitane/1,4-dinitroimidazole (CL-20/1,4-DNI) energetic cocrystal under different temperatures.

CONTEXT: To estimate the influence of temperature on properties of 2,4,6,8,10,12-hexanitro- 2,4,6,8,10,12-hexaazaisowurtzitane/1,4-dinitroimidazole (CL-20/1,4-DNI) cocrystal explosive, the supercell crystal of CL-20/1,4-DNI cocrystal model was established. The mechanical properties, sensitivity, and stability of cocrystal model under different temperatures (T = 225 K, 250 K, 275 K, 300 K, 325 K, 350 K) were predicted. Results show that mechanical parameters, including bulk modulus, tensile modulus and shear modulus are the lowest when temperature is 300 K, while Cauchy pressure is the highest, indicating that CL-20/1,4-DNI cocrystal model has better mechanical properties at 300 K. Cohesive energy density (CED) and its components energies decrease monotonically with the increase of temperature, illustrating that the CL-20 and 1,4-DNI molecules are activated and the safety of cocrystal explosive is worsened with the increase of temperature. Cocrystal model has relatively higher binding energy when the temperature is 300 K, implying that the CL-20/1,4-DNI cocrystal explosive is more stable under this condition. METHODS: The CL-20/1,4-DNI cocrystal model was optimized and the properties were predicted through molecular dynamics (MD) method. The MD simulation was performed with COMPASS force field and the ensemble was set as NPT, external pressure was set as 0.0001 GPa.

Nature-Inspired Incorporation of Precipitants into High-Strength Bulk Aluminum Alloys Enables Life-Long Extraordinary Corrosion Resistance in Diverse Aqueous Environments.

The safe service and wide applications of lightweight high-strength aluminum alloys are seriously challenged by diverse environmental corrosion, since high strength and corrosion resistance are mutually exclusive for metals while surface protection cannot provide life-long corrosion resistance. Here, inspired by fish secreting slime from glands to resist external changes, a strategy of incorporating precipitants as the slime into bulk metals using the inner cavity of opened carbon nanotubes (CNTs) as the glands is developed to enable high-strength aluminum alloys with life-long superior corrosion resistance. The resulting material has ultrahigh tensile strength (≈700 MPa) and extraordinary corrosion resistance in acidic, neutral and alkaline media. Notably, it has the highest resistance to intergranular corrosion, exfoliation corrosion and stress-corrosion cracking, compared with all previously reported aluminum alloys, and its corrosion rate is even much lower than that of corrosion-resistant pure aluminum, which results from the pronounced surface enrichment of precipitants released (secreted) from exposed CNTs forming a protective surface film. Such high corrosion resistance is life-long and self-healing due to the on-demand minimal self-supply of the precipitants dispersed throughout the bulk material. This strategy can be readily expanded to other aluminum alloys, and could pave the way for developing corrosion-resistant high-strength metallic materials.