A phased small interfering RNA-derived pathway mediates lead stress tolerance in maize.

Phased small interfering RNAs (phasiRNAs) are a distinct class of endogenous small interfering RNAs, which regulate plant growth, development and environmental stress response. To determine the effect of phasiRNAs on maize (Zea mays L.) tolerance to lead (Pb) stress, the roots of 305 maize lines under Pb treatment were subjected to generation of individual databases of small RNAs. We identified 55 high-confidence phasiRNAs derived from 13 PHAS genes (genes producing phasiRNAs) in this maize panel, of which 41 derived from nine PHAS loci were negatively correlated with Pb content in the roots. The potential targets of the 41 phasiRNAs were enriched in ion transport and import. Only the expression of PHAS_1 (ZmTAS3j, Trans-Acting Short Interference RNA3) was regulated by its cis-expression quantitative trait locus and thus affected the Pb content in the roots. Using the Nicotiana benthamiana (N. benthamiana) transient expression system, 5'-rapid amplification of cDNA ends, and Arabidopsis heterologously expressed, we verified that ZmTAS3j was cleaved by zma-miR390 and thus generated tasiRNA targeting ARF genes (tasiARFs), and that the 5' and 3' zma-miR390 target sites of ZmTAS3j were both necessary for efficient biosynthesis and functional integrity of tasiARFs. We validated the involvement of the zma-miR390-ZmTAS3j-tasiARF-ZmARF3-ZmHMA3 pathway in Pb accumulation in maize seedlings using genetic, molecular, and cytological methods. Moreover, the increased Pb tolerance in ZmTAS3j-overexpressed lines was likely attributed to the zma-miR390-ZmTAS3j-tasiARF-ZmARF3-SAURs pathway, which elevated indole acetic acid levels and thus reactive oxygen species scavenging capacity in maize roots. Our study reveals the importance of the TAS3-derived tasiRNA pathway in plant adaptation to Pb stress.

Genetic variations in ZmSAUR15 contribute to the formation of immature embryo-derived embryonic calluses in maize.

The ability of immature maize (Zea mays) embryos to form embryonic calluses (ECs) is highly genotype dependent, which limits transgenic breeding development in maize. Here, we report the association map-based cloning of ZmSAUR15 using an association panel (AP) consisting of 309 inbred lines with diverse formation abilities for ECs. We demonstrated that ZmSAUR15, which encodes a small auxin-upregulated RNA, acts as a negative effector in maize EC induction. Polymorphisms in the ZmSAUR15 promoter that influence the expression of ZmSAUR15 transcripts modulate the EC induction capacity in maize. ZmSAUR15 is involved in indole-3-acetic acid biosynthesis and cell division in immature embryo-derived callus. The ability of immature embryos to induce EC formation can be improved by the knockout of ZmSAUR15, which consequently increases the callus regeneration efficiency. Our study provides new insights into overcoming the genotypic limitations associated with EC formation and improving genetic transformation in maize.

Self-Healing Fibrous Membranes.

Inspired by the self-healing function of living organisms, self-healing materials have been developed in recent decades to very high standards. As a new direction, self-healing fibrous membranes (SFMs) exhibit both the configuration of a porous structure and self-healing capability within one material. Different from nonporous self-healing materials, it is more challenging to introduce self-healing properties to porous fibrous membrane materials owing to the more complex healing mechanism and microstructure of SFMs. This Minireview focuses on the self-healing mechanisms, design principles, and preparation strategies of SFMs. The characteristics of SFM self-healing performance are introduced in detail, and insights and perspectives of SFM preparation and healing mechanisms are put forward. Furthermore, remaining challenges and future developments of SFMs are presented, where the ultimate goal is the design of highly efficient self-healing and superstable fibrous membranes.

Superstable and Intrinsically Self-Healing Fibrous Membrane with Bionic Confined Protective Structure for Breathable Electronic Skin.

Considerable effort has been devoted to the fabrication of electronic skin that can imitate the self-healing and sensing function of biological skin. Almost all self-healing electronic skins are composed of airtight elastomers or hydrogels, which will cause skin inflammation. Fibrous membranes are ideal materials for preparing highly sensitive breathable electronic skins. However, the development of intrinsically self-healing fibrous membranes with high stability is still a challenge. Here, a novel interface protective strategy is reported to develop intrinsically self-healing fibrous membranes with a bionic confined structure for the first time, which were further assembled into an all-fiber structured electronic skin through interfacial hydrogen bonding. The electronic skin is multifunctional with self-powering, self-healing, breathability, stretchability, and thermochromism functionalities, which is highly promising for application in intelligent wearable sensing systems.

Combined GWAS and QTL analysis for dissecting the genetic architecture of kernel test weight in maize.

Kernel weight in a unit volume is referred to as kernel test weight (KTW) that directly reflects maize (Zea mays L.) grain quality. In this study, an inter-mated B73 × Mo17 (IBM) Syn10 doubled haploid (DH) population and an association panel were used to identify loci responsible for KTW of maize across multiple environments. A total of 18 significant KTW-related single-nucleotide polymorphisms (SNPs) were identified using genome-wide association study (GWAS); they were closely linked to 12 candidate genes. In the IBM Syn10 DH population, linkage analysis detected 19 common quantitative trait loci (QTL), five of which were repeatedly detected among multiple environments. Several verified genes that regulate maize seed development were found in the confidence intervals of the mapped QTL and the LD regions of GWAS, such as ZmYUC1, BAP2, ZmTCRR-1, dek36 and ZmSWEET4c. Combined QTL mapping and GWAS identified one significant SNP that was co-identified in the both populations. Based on the co-localized SNP across the both populations, 17 candidate genes were identified. Of them, Zm00001d044075, Zm00001d044086, and Zm00001d044081 were further identified by candidate gene association study for KTW. Zm00001d044081 encodes homeobox-leucine zipper protein ATHB-4, which has been demonstrated to control apical embryo development in Arabidopsis. Our findings provided insights into the mechanism underlying maize KTW and contributed to the application of molecular-assisted selection of high KTW breeding in maize.

Analysis of the genetic architecture of maize kernel size traits by combined linkage and association mapping.

Kernel size-related traits are the most direct traits correlating with grain yield. The genetic basis of three kernel traits of maize, kernel length (KL), kernel width (KW) and kernel thickness (KT), was investigated in an association panel and a biparental population. A total of 21 single nucleotide polymorphisms (SNPs) were detected to be most significantly (P < 2.25 × 10-6 ) associated with these three traits in the association panel under four environments. Furthermore, 50 quantitative trait loci (QTL) controlling these traits were detected in seven environments in the intermated B73 × Mo17 (IBM) Syn10 doubled haploid (DH) population, of which eight were repetitively identified in at least three environments. Combining the two mapping populations revealed that 56 SNPs (P < 1 × 10-3 ) fell within 18 of the QTL confidence intervals. According to the top significant SNPs, stable-effect SNPs and the co-localized SNPs by association analysis and linkage mapping, a total of 73 candidate genes were identified, regulating seed development. Additionally, seven miRNAs were found to situate within the linkage disequilibrium (LD) regions of the co-localized SNPs, of which zma-miR164e was demonstrated to cleave the mRNAs of Arabidopsis CUC1, CUC2 and NAC6 in vitro. Overexpression of zma-miR164e resulted in the down-regulation of these genes above and the failure of seed formation in Arabidopsis pods, with the increased branch number. These findings provide insights into the mechanism of seed development and the improvement of molecular marker-assisted selection (MAS) for high-yield breeding in maize.

A combination of linkage mapping and GWAS brings new elements on the genetic basis of yield-related traits in maize across multiple environments.

KEY MESSAGE: Using GWAS and QTL mapping identified 100 QTL and 138 SNPs, which control yield-related traits in maize. The candidate gene GRMZM2G098557 was further validated to regulate ear row number by using a segregation population. Understanding the genetic basis of yield-related traits contributes to the improvement of grain yield in maize. This study used an inter-mated B73 × Mo17 (IBM) Syn10 doubled-haploid (DH) population and an association panel to identify the genetic loci responsible for nine yield-related traits in maize. Using quantitative trait loci (QTL) mapping, 100 QTL influencing these traits were detected across different environments in the IBM Syn10 DH population, with 25 co-detected in multiple environments. Using a genome-wide association study (GWAS), 138 single-nucleotide polymorphisms (SNPs) were identified as correlated with these traits (P < 2.04E-06) in the association panel. Twenty-one pleiotropic QTL/SNPs were identified to control different traits in both populations. A combination of QTL mapping and GWAS uncovered eight significant SNPs (PZE-101097575, PZE-103169263, ZM011204-0763, PZE-104044017, PZE-104123110, SYN8062, PZE-108060911, and PZE-102043341) that were co-located within seven QTL confidence intervals. According to the eight co-localized SNPs by the two populations, 52 candidate genes were identified, among which the ear row number (ERN)-associated SNP SYN8062 was closely linked to SBP-transcription factor 7 (GRMZM2G098557). Several SBP-transcription factors were previously demonstrated to modulate maize ERN. We then validated the phenotypic effects of SYN8062 in the IBM Syn10 DH population, indicating that the ERN of the lines with the A-allele in SYN8062 was significantly (P < 0.05) larger than that of the lines with the G-allele in SYN8062 in each environment. These findings provide valuable information for understanding the genetic mechanisms of maize grain yield formation and for improving molecular marker-assisted selection for the high-yield breeding of maize.

Genome-wide association studies and QTL mapping uncover the genetic architecture of ear tip-barrenness in maize.

Ear tip-barrenness (ETB) phenotype threatens crop yield, because it reduces the kernel number per ear. The genetic basis of ETB in maize remains largely unknown. Herein, a genome-wide association study (GWAS) and quantitative trait loci (QTL) mapping were jointly applied to identify the significant genetic loci interrelated with ETB. Six significant SNPs were detected at a stringent P-value threshold (1.95 × 10-6 ). Additionally, four environment-stable SNPs were co-detected across a single environment and best linear unbiased prediction (BLUP) model at a less stringent P-value threshold (1 × 10-4 ). The above 10 SNPs were closely linked to 6 candidate genes, which mainly involved seed development, photosynthesis and ethylene response. Moreover, the ratio of superior allele at each significant SNP ranged from 0 to 83.33% in 30 investigated maize elite lines. QTL mapping identified 14 QTL with phenotypic variation explained (PVE) ranging from 3.64 to 7.09%, of which one QTL (qETB2-1) was repeatedly identified in two environments. Combined analysis of GWAS and QTL mapping showed that one SNP (PZE-102175229, chromosome 2: 217 66 Mb) was located in the QTL (qETB2-2, chromosome 2: 215 90-217 82 Mb). Eighteen gene models situated in the linkage disequilibrium (LD) region of the co-localized SNP were further used to evaluate their correlation with ETB by candidate gene association analysis. Two superior haplotypes and two superior alleles were detected among 74 lines for Zm00001d007195, Zm00001d007197 and Zm00001d007201. These results provide more information for clarifying the molecular mechanism of ETB and for speeding up the genetic improvement of maize varieties.

[Diversity of agronomic traits of Paris polyphylla var. chinensis and their correlation with rhizome yield and active compositions].

The supply deficiency of crude medicinal plant of Paris polyphylla var. chinensis has become a bottleneck for related medicinal industry. An important approach to increase herbal production is to breed high-yield cultivated variety, which characterized ideal plant morphology. In the present study, we collected 99 wild germplasm resources of P. polyphylla and then measured their 12 main agronomic traits and contents of polyphyllin Ⅶ,Ⅵ,Ⅱ,Ⅰ. Followed analyses were used to characterize those traits and explore the potential connection with herbal yield or quality. The results showed that: ①There was ample morphological diversity in wild P. polyphylla, whose variation of agronomic traits reduced according to followed order: content of polyphyllin, weight of dry rhizome, petiole length, stem length, petal length, pedicel length, sepal length, leaf width, leaf length, sepal width, leaf number, stamen number, petal number. ② Most of those traits were significantly correlated to each other and generally represented the characterization of photosynthetic organs or reproductive organ. ③The total content of polyphyllin Ⅶ,Ⅵ,Ⅱ,Ⅰvaried between 0.02% and 0.87% and averagedat 0.13%, which showed no significant correlation with any agronomic trait. ④Plant breeders should play more attention on those germplasm resources with large leaves, large sepals and high stem.

[Physiological and biochemical change of Paris seed in after-ripening during variable temperature stratification].

In order to explore the dormancy physiological and biochemical mechanism of Paris seeds, the seed embryo growth courses, and the dynamic change of 5 enzymes, include SOD, POD, CAT, MDH, G-6-PDH were measured during variable temperature stratification. The results indicated that Paris seeds embryo grew quickly after 40 d in warm-stratification (18 ± 1) °C, at the meantime the metabolic activity was significantly strengthened. These facts showed that Paris seeds turned into physiological after-ripening process. After 60-80 d, the morphological embryo after-ripping process basically completed, and the following cold-stratification (4 ± 1) °C furthered Paris seed to finish physiological after-ripening. After 40 d, the activity of MDH decreased while G-6-PDH increased significantly. This showed that the main respiratory pathway of seed changed from TCA to PPP, which benifited breaking seed dormancy. In the whole period of stratification process, the activity variation of SOD and CAT was insignificantly and the activity of POD was enhanced significantly after shifting the seed in cold stratification process. This showed that SOD, CAT had no direct effects on breaking Paris seed dormancy but keeping the seed vigor, while the POD might involve in the process of Paris seed dormancy breaking.

Association between white blood cell-to-haemoglobin ratio and 30 day mortality in heart failure in intensive care unit.

AIMS: The short-term mortality of heart failure (HF) patients admitted to the intensive care unit (ICU) is reported to be high. This study aims to explore the association between white blood cell-to-haemoglobin ratio (WHR) and 30 day mortality from the admission to the ICU. METHODS AND RESULTS: This retrospective cohort study was performed based on the Medical Information Mart for Intensive Care III (MIMIC-III) database (2001-12) and MIMIC-IV database (2008-19). Covariables were selected using the least absolute shrinkage and selection operator regression. Based on the optimal cutoff point selected using the survminer package, WHR was divided into high-ratio group (≥1.6) and low-ratio group (<1.6). The association between WHR and the risk of 30 day mortality was explored using univariate and multivariable Cox regression models. The area under the receiver operating characteristic curve (AUC) was calculated to evaluate the prediction performance of WHR. A total of 13 702 patients were included. After adjusting the potential covariates, high WHR was associated with a greater risk of 30 day mortality compared with low WHR [hazard ratio = 1.16, 95% confidence interval (CI): 1.07-1.27, P < 0.001]. WHR also showed a good performance for the prediction of risk of 30 day mortality (AUC = 0.751, 95% CI: 0.746-0.756). CONCLUSIONS: WHR was positively associated with and performed well to predict 30 day mortality, indicating that WHR may be a reliable index to assess the prognosis of HF patients admitted to the ICU.

Efficient Synthesis of Fe3O4/PPy Double-Carbonized Core-Shell-like Composites for Broadband Electromagnetic Wave Absorption.

Ever-increasing electromagnetic pollution largely affects human health, sensitive electronic equipment, and even military security, but current strategies used for developing functional attenuation materials cannot be achieved in a facile and cost-effective way. Here, a unique core-shell-like composite was successfully synthesized by a simple chemical approach and a rapid microwave-assisted carbonization process. The obtained composites show exceptional electromagnetic wave absorption (EMWA) properties, including a wide effective absorption band (EAB) of 4.64 GHz and a minimum reflection loss (RLmin) of -26 dB at 1.6 mm. The excellent performance can be attributed to the synergistic effects of conductive loss, dielectric loss, magnetic loss, and multiple reflection loss within the graphene-based core-shell-like composite. This work demonstrates a convenient, rapid, eco-friendly, and cost-effective method for synthesizing high-performance microwave absorption materials (MAMs).

Knowledge, Attitudes, and Practices Among Elderly CHD Patients Towards Self-Perceived Health Abilities.

Objective: This study aimed to assess the knowledge, attitudes and practices (KAP) among elderly coronary heart disease (CHD) patients toward self-perceived health abilities. Methods: This web-based study was carried out between April 2023 and September 2023 at Guang'anmen Hospital, China Academy of Chinese Medical Sciences. A self-developed questionnaire was utilized to collect demographic information from elderly CHD patients, and evaluate their KAP towards self-perceived health abilities. Results: A total of 568 valid questionnaires were collected. Among the participants, the average age was 65.97±5.50 years, and 298 (52.46%) were female, and the mean scores for knowledge, attitudes, and practices were 6.34±2.29 (possible range: 0-9), 35.24±4.99 (possible range: 9-45), and 27.79±10.09 (possible range: 9-45), respectively. The structural equation model demonstrated that elderly CHD patients' knowledge directly affects attitudes and practices, with path coefficient of 0.93 (P<0.001) and 0.39 (P=0.033), respectively. Moreover, attitudes play an intermediary role between knowledge and practice with path coefficient of 0.75 (P<0.001). Furthermore, residence directly affects knowledge with path coefficient of 0.67 (P<0.001), cardiac function directly affects knowledge with path coefficient of -0.97 (P<0.001) and history of interventional therapy directly affects practice with path coefficient of 4.23 (P<0.001). Conclusion: Elderly CHD patients demonstrated sufficient knowledge, positive attitudes, and proactive practices towards self-perceived health abilities. However, educational programs and behavior modification are recommended, particularly for elderly with lower age and education, living in rural areas, lacking interventional therapy, obese, or taking multiple CHD medications.

PlantMine: A Machine-Learning Framework to Detect Core SNPs in Rice Genomics.

As a fundamental global staple crop, rice plays a pivotal role in human nutrition and agricultural production systems. However, its complex genetic architecture and extensive trait variability pose challenges for breeders and researchers in optimizing yield and quality. Particularly to expedite breeding methods like genomic selection, isolating core SNPs related to target traits from genome-wide data reduces irrelevant mutation noise, enhancing computational precision and efficiency. Thus, exploring efficient computational approaches to mine core SNPs is of great importance. This study introduces PlantMine, an innovative computational framework that integrates feature selection and machine learning techniques to effectively identify core SNPs critical for the improvement of rice traits. Utilizing the dataset from the 3000 Rice Genomes Project, we applied different algorithms for analysis. The findings underscore the effectiveness of combining feature selection with machine learning in accurately identifying core SNPs, offering a promising avenue to expedite rice breeding efforts and improve crop productivity and resilience to stress.

Jellyfish-Inspired Soft Robot Driven by Pneumatic Bistable Actuators.

Soft actuators offer numerous potential applications; however, challenges persist in achieving a high driving force and fast response speed. In this work, we present the design, fabrication, and analysis of a soft pneumatic bistable actuator (PBA) mimicking jellyfish subumbrellar muscle motion for waterjet propulsion. Drawing inspiration from the jellyfish jet propulsion and the characteristics of bistable structure, we develop an elastic band stretch prebending PBA with a simple structure, low inflation cost, exceptional driving performance, and stable driving force output. Through a bionic analysis of jellyfish body structure and motion, we integrate the PBA into a jellyfish-like prototype, enabling it to achieve jet propulsion. To enhance the swimming performance, we introduce a skin-like structure for connecting the soft actuator to the jellyfish-like soft robot prototype. This skin-like structure optimizes the fluid dynamics during jet propulsion, resulting in improved efficiency and maneuverability. Our study further analyzes the swimming performance of the jellyfish-like prototype, demonstrating a swimming speed of 3.8 cm/s (0.32 body length/s, BL/s) for the tethered prototype and 4.7 cm/s (0.38 BL/s) for the untethered prototype. Moreover, we showcase the jellyfish-like prototype's notable load-bearing capacity and fast-forward swimming performance compared to other driving methods for underwater biomimetic robots. This work provides valuable insights for the development of highly agile and fast responsive soft robots that imitate the subumbrellar muscle of jellyfish for efficient water-jet propulsion, utilizing skin-like structures to enhance swimming performance.

Electric-magnetic dual-gradient structure design of thin MXene/Fe3O4 films for absorption-dominated electromagnetic interference shielding.

The challenge of achieving high-performance electromagnetic interference (EMI) shielding films, which focuses on electromagnetic waves absorption while maintaining thin thickness, is a crucial endeavor in contemporary electronic device advancement. In this study, we have successfully engineered hybrid films based on MXene nanosheets and Fe3O4 nanoparticles, featuring intricate electric-magnetic dual-gradient structures. Through the collaborative influence of a unique dual-gradient structure equipped with transition and reflection layers, these hybrid films demonstrate favorable impedance matching, abundant loss mechanisms (Ohmic loss, interfacial polarization and magnetic loss), and an "absorb-reflect-reabsorb" process to achieve absorption-dominated EMI shielding capability. Compared with the single conductive gradient structure, the dual-gradient structure effectively enhances the absorption intensity per unit thickness, and thus reduces the thickness of the film. The optimized film demonstrates a remarkable EMI shielding effectiveness (SE) of 49.98 dB alongside an enhanced absorption coefficient (A) of 0.51 with a thickness of only 180 µm. The thin films with a dual-gradient structure hold promise for crafting absorption-dominated electromagnetic shielding materials, highlighting the potential for advanced electromagnetic protection solutions.

Combined genome-wide association study and gene co-expression network analysis identified ZmAKINßγ1 involved in lead tolerance and accumulation in maize seedlings.

Lead (Pb) contamination has become an important abiotic stress that negatively influences crop biomass and yield, threatening human health via food chains. The excavation of causal genes for Pb tolerance in maize will contribute to the breeding of Pb-tolerant maize germplasms. This study aimed to demonstrate the effects of AKINbetagamma-1 protein kinase (ZmAKINßγ1) on maize tolerance to Pb and reveal its molecular mechanisms underlying Pb tolerance. ZmAKINßγ1 was identified using genome-wide association study and weighted gene co-expression network analysis for shoot dry weight (SDW) and root dry weight (RDW) under Pb treatment. The OE and RNAi experiments showed that ZmAKINßγ1 negatively regulated maize tolerance to Pb by reducing SDW and RDW and increasing Pb accumulation in maize. Comparative transcriptome analysis between the OE/RNAi and wild-type lines revealed that ZmAKINßγ1 participated in the pectin metabolism process and nitrogen compound response. Gene-based association analyses revealed that three variants located in ZmAKINßγ1 promoter induced changes in its expression and Pb tolerance among maize lines. The dual-luciferase reporter system verified that the two genotypes (AAT and CGG) of ZmAKINßγ1 promoter had contrasting transcriptional activities. Collectively, ZmAKINßγ1-mediated Pb tolerance provided new insights into the cultivation of Pb-tolerant maize varieties and phytoremediation of Pb-polluted soils.

High Electromechanical Coupling Coefficient of Longitudinally Excited Shear Wave Resonator Based on Optimized Bragg Structure.

In this work, a longitudinally excited shear-wave resonator (YBAR) based on single-crystalline lithium tantalate (LiTaO3, LT) thin film is proposed. The YBAR has a 200 nm X-cut thin film and molybdenum electrode. A high effective electromechanical coupling coefficient (k2eff) of up to 19% for the suspension-type structure was obtained. Furthermore, a Bragg reflector (SiO2/Pt) with optimized layer thickness ratio was employed to improve the performance of the YBAR. Compared to the acoustic wave resonators with the conventional quarter-wave (λ/4) Bragg reflector, the proposed YBAR with an optimized Bragg reflector can reflect both the longitudinal and shear waves efficiently, and resonators with spurious-free response and high quality (Q) value were achieved. This work provides a potential solution to enabling high coupling micro-acoustic resonators with high Q factor in the 5G/6G communication system.

Evolution of nanostructured skin patches towards multifunctional wearable platforms for biomedical applications.

Recent advances in the field of skin patches have promoted the development of wearable and implantable bioelectronics for long-term, continuous healthcare management and targeted therapy. However, the design of electronic skin (e-skin) patches with stretchable components is still challenging and requires an in-depth understanding of the skin-attachable substrate layer, functional biomaterials and advanced self-powered electronics. In this comprehensive review, we present the evolution of skin patches from functional nanostructured materials to multi-functional and stimuli-responsive patches towards flexible substrates and emerging biomaterials for e-skin patches, including the material selection, structure design and promising applications. Stretchable sensors and self-powered e-skin patches are also discussed, ranging from electrical stimulation for clinical procedures to continuous health monitoring and integrated systems for comprehensive healthcare management. Moreover, an integrated energy harvester with bioelectronics enables the fabrication of self-powered electronic skin patches, which can effectively solve the energy supply and overcome the drawbacks induced by bulky battery-driven devices. However, to realize the full potential offered by these advancements, several challenges must be addressed for next-generation e-skin patches. Finally, future opportunities and positive outlooks are presented on the future directions of bioelectronics. It is believed that innovative material design, structure engineering, and in-depth study of fundamental principles can foster the rapid evolution of electronic skin patches, and eventually enable self-powered close-looped bioelectronic systems to benefit mankind.

Nanocrystalline cellulose extracted from bast fibers: Preparation, characterization, and application.

Nanocrystalline cellulose (NCC) have gained great attention owing to their extraordinary properties such as biocompatibility, biodegradability, high crystallinity index (>70%), large surface area (~150 m2/g), high aspect ratio (~70), and high tensile strength (7500 MPa). Bast fibers, with compelling features of easy availability, high fiber length, and high cellulose content, are considered to be competitive raw materials to prepare high quality NCC. Generally, NCC can be obtained by mechanical, chemical, biological or combining methods with the removal of non-cellulosic components from bast fibers. This work summarizes the comprehensive research advancement of NCC extracted from bast fibers. Comparison analysis of geometrical dimensions and microstructure morphologies of NCC are conducted to evaluate the strengths and weaknesses of each preparation method. The characterization of NCC and the application of NCC in many emerging fields are systematically introduced. A detailed discussion of current challenges and future outlook are provided to inspire the relevant researchers.