Agrobacterium-mediated transformation of B. juncea reveals that BjuLKP2 functions in plant yellowing.

KEY MESSAGE: A stable Agrobacterium-mediated transformation system was constructed for B. juncea, and BjuLKP2 was overexpressed, leading to plant yellowing. A stable and efficient transformation system is necessary to verify gene functions in plants. To establish an Agrobacterium-mediated transformation system for B. juncea, various factors, including the explant types, hormone combination and concentration, infection time and concentration, were optimized. Eventually, a reliable system was established, and two BjuLKP2 overexpression (OE) lines, which displayed yellowing of cotyledons, shoot tips, leaves and flower buds, as well as a decrease in total chlorophyll content, were generated. qRT-PCR assays revealed significant upregulation of five chlorophyll synthesis genes and downregulation of one gene in the BjuLKP2 OE line. Furthermore, antioxidant capacity assays revealed reduced activities of APX, CAT and SOD, while POD activity increased in the BjuLKP2 OE26. Additionally, the kinetic determination of chlorophyll fluorescence induction suggested a decrease in the photosynthetic ability of BjuLKP2 OE26. GUS assays revealed the expression of BjuLKP2 in various tissues, including the roots, hypocotyls, cotyledons, leaf vasculature, trichomes, sepals, petals, filaments, styles and stigma bases, but not in seeds. Scanning electron revealed alterations in chloroplast ultrastructure in both the sponge and palisade tissue. Collectively, these findings indicate that BjuLKP2 plays a role in plant yellowing through a reduction in chlorophyll content and changes in chloroplasts structure.

Machine learning for predicting hematoma expansion in spontaneous intracerebral hemorrhage: a systematic review and meta-analysis.

PURPOSE: Early identification of hematoma enlargement and persistent hematoma expansion (HE) in patients with cerebral hemorrhage is increasingly crucial for determining clinical treatments. However, due to the lack of clinically effective tools, radiomics has been gradually introduced into the early identification of hematoma enlargement. Though, radiomics has limited predictive accuracy due to variations in procedures. Therefore, we conducted a systematic review and meta-analysis to explore the value of radiomics in the early detection of HE in patients with cerebral hemorrhage. METHODS: Eligible studies were systematically searched in PubMed, Embase, Cochrane and Web of Science from inception to April 8, 2024. English articles are considered eligible. The radiomics quality scoring (RQS) tool was used to evaluate included studies. RESULTS: A total of 34 studies were identified with sample sizes ranging from 108 to 3016. Eleven types of models were involved, and the types of modeling contained mainly clinical, radiomic, and radiomic plus clinical features. The radiomics models seem to have better performance (0.77 and 0.73 C-index in the training cohort and validation cohort, respectively) than the clinical models (0.69 C-index in the training cohort and 0.70 C-index in the validation cohort) in discriminating HE. However, the C-index was the highest for the combined model in both the training (0.82) and validation (0.79) cohorts. CONCLUSIONS: Machine learning based on radiomic plus clinical features has the best predictive performance for HE, followed by machine learning based on radiomic features, and can be used as a potential tool to assist clinicians in early judgment.

Insights into the Binding Profile of Anti-chlorpyrifos Recombinant Antibodies: From Computational Simulation to Immunoassay Validation.

A novel virtual screening strategy was proposed for the profiling and discovery of active variable regions (VRs) that encode hapten-specific recombinant antibodies (rAbs). Chlorpyrifos, a hazardous organophosphorus pesticide, was selected as the target. First, a VR model-14G4 from anti-chlorpyrifos hybridoma was built via homology modeling. Its binding pattern toward seven organophosphorus analogues was assessed through virtual screening by performing molecular docking. Based on energy scoring, visual examination, and molecular interaction analysis, chlorpyrifos-methyl was also inferred as the high-affinity target for model-14G4 and was then confirmed via a non-competitive surface plasmon resonance (SPR) assay. Subsequently, we attempted to discover hapten-specific VRs by creating a collection of VR models for anonymous testing. Chlorpyrifos and model-14G4 were employed as the known hit and active VRs, respectively. After molecular docking, a novel anti-chlorpyrifos VR (model-1) was identified due to its satisfactory energy scoring and a similar binding pattern to the reference model-14G4. Expressed by HEK293(F) mammalian cells, the newly prepared full-length rAb-model-1 and rAb-14G4 exhibited high sensitivities for detecting chlorpyrifos by the indirect competitive enzyme-linked immunosorbent assay (ic-ELISA), with IC50 of 3.01 ng/mL and 42.82 ng/mL, respectively. They recognized chlorpyrifos-methyl with a cross-reactivity (CR) of 2.5-17.3%. Moreover, the binding properties of rAb-model-1 for recognizing chlorpyrifos and chlorpyrifos-methyl were confirmed via a non-competitive microscale thermophoresis (MST) method. Thus, the experimental results showed good agreement with computational outputs on antibody profiling. Furthermore, the recognition diversity of rAb-model-1 for chlorpyrifos and chlorpyrifos-methyl was studied via molecular dynamics simulation. Overall, the proposed study provides a versatile and economical strategy for antibody characterization and promotes the in vitro production of rAbs for pesticide monitoring.

Genome-wide identification of nucleotide-binding domain leucine-rich repeat (NLR) genes and their association with green peach aphid (Myzus persicae) resistance in peach.

Resistance genes (R genes) are a class of genes that are immune to a wide range of diseases and pests. In planta, NLR genes are essential components of the innate immune system. Currently, genes belonging to NLR family have been found in a number of plant species, but little is known in peach. Here, 286 NLR genes were identified on peach genome by using their homologous genes in Arabidopsis thaliana as queries. These 286 NLR genes contained at least one NBS domain and LRR domain. Phylogenetic and N-terminal domain analysis showed that these NLRs could be separated into four subfamilies (I-IV) and their promoters contained many cis-elements in response to defense and phytohormones. In addition, transcriptome analysis showed that 22 NLR genes were up-regulated after infected by Green Peach Aphid (GPA), and showed different expression patterns. This study clarified the NLR gene family and their potential functions in aphid resistance process. The candidate NLR genes might be useful in illustrating the mechanism of aphid resistance in peach.

OsUGE1 is directly targeted by OsGRF6 to regulate root hair length in rice.

KEY MESSAGE: Root hairs are required for water and nutrient acquisition in plants. Here, we report a novel mechanism that OsUGE1 is negatively controlled by OsGRF6 to regulate root hair elongation in rice. Root hairs are tubular outgrowths generated by the root epidermal cells. They effectively enlarge the soil-root contact area and play essential roles for nutrient and water absorption. Here, in this study, we demonstrated that the Oryza sativa UDP-glucose 4-epimerase 1-like (OsUGE1) negatively regulated root hair elongation and was directly targeted by Oryza sativa growth regulating factor 6 (OsGRF6). Knockout mutants of OsUGE1 using CRISPR-Cas9 technology showed longer root hairs than those of wild type. In contrast, overexpression lines of OsUGE1 displayed shorter root hair compared with those of wild type. GUS staining showed that it could specifically express in root hair. Subcellular localization analysis indicates that OsUGE1 is located in endoplasmic reticulum, nucleus and plasma membrane. More importantly, ChIP-qPCR, Yeast-one-hybrid and BiFC experiments revealed that OsGRF6 could bind to the promoter of OsUGE1. Furthermore, knockout mutants of OsGRF6 showed shorter root hair than those of wild type, and OsGRF6 dominantly expressed in root. In addition, the expression level of OsUGE1 is significantly downregulated in Osgrf6 mutant. Taken together, our study reveals a novel pathway that OsUGE1 is negatively controlled by OsGRF6 to regulate root hair elongation in rice.

Advent of severe mitral regurgitation in surgical ventricular restoration and ventricular septal rupture repair.

BACKGROUND: Per-procedural severe mitral regurgitation is a rare complication in concomitant surgical ventricular restoration and postinfarction ventricular septal rupture repair. It is challenging to discover the underlying etiology and adopt an appropriate strategy, in particular, in a high-risk patient. CASE PRESENTATION: Semi-emergent surgical ventricular restoration combined with ventricular septal rupture closure and coronary artery bypassing was performed in a 67-year-old male patient. Severe mitral regurgitation was detected after the weaning of cardiopulmonary bypass. Two key questions arose in the management of this condition: did the regurgitation exist previously and was dissimulated by significant left-to-right shunt, or it occurred secondarily to the Dor procedure? Which was the better management strategy, chordal-sparing mitral valve replacement or mitral plasty? We believed that severe mitral regurgitation was under-estimated pre-operatively and we performed an downsizing annuloplasty to treat mitral regurgitation. The outcomes were promising and the patient did well in follow-up. CONCLUSIONS: Our case brought out an open discussion on the etiology and therapeutic strategies of this complicated condition.

Correlation analysis between physical activity and depressive tendencies among occupational groups: an isotemporal substitution approach.

OBJECTIVES: Sedentary behaviour (SB) and physical activity (PA) have been shown to be associated with depression. However, behaviours, such as PA, occupy a portion of an individual's 24-h day. Thus, an increase in time for one behaviour takes away time from another. Previous evidence suggests that it would be more appropriate to shift the focus to the importance of reallocating time spent in sedentary behaviour to time spent in physical activity. The aim of this study was to analyse the mutual replacement effect of different health behaviours on depressive tendencies by isotemporal substitution modelling (ISM) under the objective condition of considering a limited 24-h day. Second, we aimed to further explore the potential association between excessive or insufficient sleep duration and depressive symptoms. METHODS: A total of 10656 employees from 79 companies in four provinces of China participated in this survey. The Center for Epidemiological Studies Depression Scale (CES-D) was used to measure workers' depressive tendencies. The duration of various types of physical activity was self-reported by workers based on the International Physical Activity Questionnaire (IPAQ). ISM was used to assess the associations of time spent in different activities on displacement of equivalent time spent on other activities with depression risk. RESULTS: A total of 10656 participants (89.5% of the sample) were included in the analysis. The ISM found that a 30-min unit of SB replaced with walking (OR, 95% CI: 0.83, 0.77-0.88), sleep (≤ 8 h) (OR, 95% CI: 0.77, 0.74-0.79), moderate physical activity (MPA) (OR, 95% CI: 0.87, 0.81-0.93) and vigorous physical activity (VPA) (OR, 95% CI: 0.91, 0.84-0.99) was significantly and negatively associated with the risk of depressive tendencies. When sleep duration was less than 8 h, each additional half hour of sleep time was significantly associated with a lower risk of depressive tendencies, and this association was no longer significant after 8 h. CONCLUSION: Prolonged SB is common in the current workplace in China. Replacing an average of 30 min per day of SB with VPA and MPA, even walking is associated with less depression among workers. In addition, insufficient daily sleep is also an important risk factor for workers' depressive tendencies. These findings provide valuable evidence to promote mental health among occupational groups and support the development of healthy workplaces.

TOE1/TOE2 Interacting with GIS to Control Trichome Development in Arabidopsis.

Trichomes are common appendages originating and projecting from the epidermal cell layer of most terrestrial plants. They act as a first line of defense and protect plants against different types of adverse environmental factors. GL3/EGL3-GL1-TTG1 transcriptional activator complex and GIS family genes regulate trichome initiation through gibberellin (GA) signaling in Arabidopsis. Here, our novel findings show that TOE1/TOE2, which are involved in developmental timing, control the initiation of the main-stem inflorescence trichome in Arabidopsis. Phenotype analysis showed that the 35S:TOE1 transgenic line increases trichome density of the main-stem inflorescence in Arabidopsis, while 35S:miR172b, toe1, toe2 and toe1toe2 have the opposite phenotypes. Quantitative RT-PCR results showed that TOE1/TOE2 positively regulate the expression of GL3 and GL1. In addition, protein-protein interaction analysis experiments further demonstrated that TOE1/TOE2 interacting with GIS/GIS2/ZFP8 regulate trichome initiation in Arabidopsis. Furthermore, phenotype and expression analysis also demonstrated that TOE1 is involved in GA signaling to control trichome initiation in Arabidopsis. Taken together, our results suggest that TOE1/TOE2 interact with GIS to control trichome development in Arabidopsis. This report could provide valuable information for further study of the interaction of TOE1/TOE2 with GIS in controlling trichome development in plants.

C2H2 Zinc Finger Proteins Response to Abiotic Stress in Plants.

Abiotic stresses have already exhibited the negative effects on crop growth and development, thereby influencing crop quality and yield. Therefore, plants have developed regulatory mechanisms to adopt against such harsh changing environmental conditions. Recent studies have shown that zinc finger protein transcription factors play a crucial role in plant growth and development as well as in stress response. C2H2 zinc finger proteins are one of the best-studied types and have been shown to play diverse roles in the plant abiotic stress responses. However, the C2H2 zinc finger network in plants is complex and needs to be further studied in abiotic stress responses. Here in this review, we mainly focus on recent findings on the regulatory mechanisms, summarize the structural and functional characterization of C2H2 zinc finger proteins, and discuss the C2H2 zinc finger proteins involved in the different signal pathways in plant responses to abiotic stress.

Fifteen-Year Outcomes After Valve-Sparing Aortic Root Remodelling or Exclusion of the Non-Coronary Sinus: When to Preserve the Sinuses of Valsalva?

BACKGROUND: Isolated exclusion of the non-coronary sinus (NCS) is an attractive strategy in valve-sparing aortic root surgery, which avoids the mobilisation and re-implantation of coronary ostia. However, the long-term durability of aortic valve repair and the fate of remnant sinuses of Valsalva remain unclear. METHOD: From January 2006 to December 2013, 29 patients underwent replacement of the ascending aorta extending to the NCS (group NCS) and 56 patients underwent a modified Yacoub procedure (group MY) in our centre by a single surgeon. Significant difference of preoperative parameters was observed between two groups in the presence of bicuspid aortic valve (41.4% vs 12.5%, p=0.002) and the diameter of the sinus of Valsalva (47.3±4.7 mm vs 51.5±4.9 mm, p=0.01). RESULTS: The group NCS, as compared to the group MY, was associated with significantly shorter cardiopulmonary bypass time (106.6±40.5 min vs 138.4±37.5 min, p=0.001) and aortic cross clamping time (69.0±21.8 min vs 105.4±27.8 min, p<0.01). The mean follow-up was 11.5±2.8 years. No surgical re-intervention was performed for aortopathies of the aortic root; the neo-sinus were not dilated in either groups (38.2±4.2 mm vs 34.0±4.0 mm, p<0.01). The 10-year freedom from aortic valve-related re-operation was estimated to be 96.6±3.4% and 94.5±3.1% (p=0.58), and the cumulative 10-year survival rates were 95.2±4.6% and 85.6±4.7% (p=0.61) in the group NCS and the group MY, respectively. CONCLUSIONS: Aortic valve-sparing isolated NCS replacement can be safely performed in selected patients; its early outcomes, overall survival and long-term freedom from aortic valve-related or aortopathy-related re-intervention were comparable to those obtained with the Yacoub procedure.

Fifteen-Year Outcomes Following Valve-Sparing Aortic Root Replacement in Elderly Patients.

BACKGROUND: Valve-sparing aortic root replacement (VSRR) techniques have several advantages such as preservation of physiological haemodynamics of the native aortic valve and avoidance of prosthetic valve-related complications. However, VSRR procedures are generally performed in young patients and the long-term results in elderly patients (≥65 years) are scarce. METHODS: Fifty-six (56) consecutive patients underwent VSRR surgery by a single surgeon at the current centre between January 2006 and December 2013; a modified "remodelling technique" was typically performed. The mean age was 58.86±12.5 years; Marfan syndrome and bicuspid aortic valve were both present in six patients (10.7%); 38 patients (67.8%) presented with greater than moderate aortic regurgitation; and 17 patients (30.4%) were in New York Heart Association (NYHA) class III before surgery. They were divided into two groups according to their ages receiving VSRR surgery: Group E (elderly patients aged ≥65 years, n=24) and Group Y (young patients aged <65 years, n=32). The primary outcomes were aortic valve-related reoperation, cardiovascular reoperation, all-cause mortality, and functional status. RESULTS: One (1) patient in Group E was converted to aortic valve replacement as a result of a failed aortic valve repair. No perioperative mortality was observed. The mean follow-up was 11.5±2.9 years. Aortic valve-related reoperation was noted in two patients of each group (one with endocarditis, one with severe aortic regurgitation). Cardiovascular reoperations were observed in three and six patients, and all-cause deaths in seven and two patients in Group E and Group Y, respectively. The 10-year freedom from aortic valve-related reoperation was estimated to be 91.7±5.6% and 92.7±5.0% (p=0.594), the 10-year freedom from cardiovascular reoperation was 86.4±7.3% and 81.1±7.7% (p=0.781), and the cumulative 10-year survival rates were 74.0±9.2% and 93.8±4.3% (p=0.018) in Group E and Group Y, respectively. During follow-up, 6.7% of patients were in NYHA class III and 6.4% of patients developed moderate-to-severe aortic regurgitation. Cox regression analysis failed to identify predictors for primary outcomes. CONCLUSION: Valve-sparing aortic root replacement can safely be performed in elderly patients with low early mortality and satisfactory long-term freedom from aortic valve-related and cardiovascular re-intervention.

Radial-cavity quartz-enhanced photoacoustic spectroscopy.

Radial-cavity quartz-enhanced photoacoustic spectroscopy (RC-QEPAS) was proposed for trace gas analysis. A radial cavity with (0,0,1) resonance mode was coupled with the quartz tuning fork (QTF) to greatly enhance the QEPAS signal and facilitate the optical alignment. The coupled resonance enhancement effects of the radial cavity and QTF were analyzed theoretically and researched experimentally. With an optimized radial cavity, the detection sensitivity of QEPAS was enhanced by >1 order of magnitude. The RC-QEPAS makes the acoustic detection module more compact and optical alignment comparable with a bare QFT, benefiting the usage of light sources with poor beam quality.

The association of workplace smoke-free policies on individual smoking and quitting-related behaviours.

BACKGROUND: Our study aims to provide information about workplace smoke-free (SF) policy coverage in mainland China and to assess the relationship between workplace SF policies and secondhand smoke (SHS) exposure, current smoking, smoking harm awareness and quitting intention among smokers. METHOD: Data from the 2018 Asia Best Workplace Mainland China programme were used to address these aims. This cross-sectional study included 14,195 employees from the 2018 survey and 14,953 employees from the 2019 survey. Logistic regression with year-fixed effects was applied to these data. The dependent variables were SHS exposure, smoking or smoking harm awareness. The explanatory variable was the SF workplace policy. RESULTS: A total of 21,275 participants (73.0%) reported working under SF policies. The overall prevalence of smoking and SHS exposure were 20.3% and 52.5%, respectively. The workplace SF policy was significantly associated with lower SHS exposure (OR: 0.48, 95% CI: 0.45-0.51), lower current smoking employees (OR: 0.81, 95% CI: 0.76-0.87) and higher awareness of smoking harm (OR: 1.76, 95% CI: 1.61-1.91). However, workplace SF policy was not significantly associated with quitting intention (OR: 0.99, 95% CI: 0.84-1.16). CONCLUSION: Our study identified that although most companies had established workplace SF policies, the overall prevalence of SHS exposure remained very high. Workplace SF policy is associated with lower SHS exposure, lower overall current smoking and higher awareness of smoking harm. These findings provide valuable evidence to promote such policies in all workplaces.

In Situ Strain Evolution on Pt Nanoparticles during Hydrogen Peroxide Decomposition.

Fundamental understanding of structural changes during catalytic reactions is crucial to understanding the underlying mechanisms and optimizing efficiencies. Surface energy and related catalytic mechanisms are widely studied. However, the catalyst lattice deformation induced by catalytic processes is not well understood. Here, we study the strain in an individual platinum (Pt) nanoparticle (NP) using Bragg coherent diffraction imaging under in situ oxidation and reduction reactions. When Pt NPs are exposed to H2O2, a typical oxidizer and an intermediate during the oxygen reduction reaction process, alternating overall strain distribution near the surface and inside the NP is observed at the (111) Bragg reflection. In contrast, relatively insignificant changes appear in the (200) reflection. Density functional theory calculations are employed to rationalize the anisotropic lattice strain in terms of induced stress by H2O2 adsorption and decomposition on the Pt NP surface. Our study provides deeper insight into the activity-structure relationship in this system.

Evaluation of Polycyclic Aromatic Hydrocarbons (PAHs) in Bamboo Shoots from Soil.

The toxicity, carcinogenicity and persistence of polycyclic aromatic hydrocarbons (PAHs) pose a great threat to the ecological system and human health. The contamination levels, translocation and source analysis of 16 PAHs in bamboo shoot and its planted soil were investigated. The average concentrations of total PAHs were 18.80 ± 1.90 µg/kg and 123.98 ± 113.36 µg/kg in bamboo shoots and soils, respectively. The most abundant PAH was Phenanthrene (PHE), with the detected average concentrations of 5.85 µg/kg in bamboo shoots and 19.28 µg/kg in soils. The highest detected types of PAHs were 3 rings and 4 rings, with the proportions of 80.69% (bamboo shoots) and 35.23% (soils). The transfer factors of PAHs were ranged from 0.011 to 0.895, in which PAHs with 3 rings showed the strongest transfer ability. The combustion of biomass and petroleum might be the main source of PAHs in the planted soils of bamboo shoots.

Characterization of iron walnut in different regions of China based on phytochemical composition.

Little is known about the phytochemical composition of iron walnuts. Differences in the geographical origin of iron walnuts associated with economic benefits should also be examined. In this study, the phytochemical composition (fatty acids, Vitamin E, total polyphenols and flavonoids, amino acids, and minerals) of iron walnuts in China was investigated. The results showed that there were significant differences (p < 0.05) in the phytochemical composition of iron walnut oils and flours from different regions. Positive (r > 0.5, p < 0.05) and negative (r < - 0.5, p < 0.05) correlations were found between amino acids/minerals and amino acids/oleic acid, with the highest correlation coefficient (r = 0.742, p < 0.05) between Cu and tyrosine. In addition, based on the 12 phytochemical fingerprints selected by random forest, a geographical-origin identification model for iron walnuts was established, with a corresponding correct classification rate of 96.6%. The top three phytochemical fingerprints for the geographical-origin identification of iron walnut were microelements, macroelements, and antioxidant composition, with contribution rates of 61.7%, 18.1%, and 9.9%, respectively.

Quartz-enhanced photoacoustic spectroscopy exploiting a fast and wideband electro-mechanical light modulator.

A quartz-enhanced photoacoustic spectroscopy (QEPAS) gas sensor exploiting a fast and wideband electro-mechanical light modulator was developed. The modulator was designed based on the electro-mechanical effect of a commercial quartz tuning fork (QTF). The laser beam was directed on the edge surface of the QTF prongs. The configuration of the laser beam and the QTF was optimized in detail in order to achieve a modulation efficiency of ∼100%. The L-band single wavelength laser diode and a C-band tunable continuous wave laser were used to verify the performance of the developed QTF modulator, respectively, realizing a QEPAS sensor based on amplitude modulation (AM). As proof of concept, the AM-based QEPAS sensor demonstrated a detection limit of 45 ppm for H2O and 50 ppm for CO2 with a 1 s integration time respectively.

Sub-ppb-level CH4 detection by exploiting a low-noise differential photoacoustic resonator with a room-temperature interband cascade laser.

An ultra-highly sensitive and robust CH4 sensor is reported based on a 3.3 µm interband cascade laser (ICL) and a low-noise differential photoacoustic (PAS) cell. The ICL emission wavelength targeted a fundamental absorption line of CH4 at 2988.795 cm-1 with an intensity of 1.08 × 10-19 cm/molecule. The double-pass and differential design of the PAS cell effectively enhanced the PAS signal amplitude and decreased its background noise. The wavelength modulation depth, operating pressure and V-T relaxation promotion were optimized to maximize the sensor detection limit. With an integration time of 90 s, a detection limit of 0.6 ppb was achieved. No additional water or air laser cooling were required and thereby allowing the realization of a compact and robust CH4 sensor.

Multi-Targeting by ß-Elemene and Its Anticancer Properties: A Good Choice for Oncotherapy and Radiochemotherapy Sensitization.

Several studies have focused on chemical agents, tailored from natural edible products, used to prevent and treat various diseases. ß-elemene is a well-known compound derived from Curcuma wenyujin that possesses a wide spectrum of anticancer properties under preclinical and clinical conditions. Several studies have demonstrated its inhibitory effect both in humans and animals with cancers. Numerous in vivo and in vitro experimental models have revealed that ß-elemene can modulate multiple molecular pathways involved in carcinogenesis. In general, (1) ß-elemene itself can inhibit and kill tumor cells through a variety of mechanisms, and (2) can synergistically enhance the effect of radiotherapy and/or chemotherapy, (3) also can regulate autoimmune in the treatment of tumors. In this article, we critically focused on the available scientific evidence discussing the use of ß-elemene in cancer prevention, and its molecular targets and mechanisms of action in different types of cancer. In addition, we have discussed its sources, chemistry, bioavailability, and future research directions.

Evaluation of risk levels of trace elements in walnuts from China and their influence factors: Planting area and cultivar.

The potential health risk of trace elements in nut foods has been widely concerned. The accumulations of trace elements by plants in the environment are disturbed by multiple factors. The objective of this work was to investigate the risk levels of trace elements in walnuts and their influence factors (planting area and cultivar). A total of 228 walnut samples were collected from four major walnut producing areas of China. The contents of essential elements for Fe, Cu, Zn, Mo and Se were 35.8, 21.9, 14.8, 0.3 and 0.04 mg/kg, respectively. The contribution of Cu for dietary reference intake was as high as 82.22%. The risk levels of potential toxicological elements and toxic elements within the acceptable limits. Significantly, the hazard quotients (HQs) of Ba and Co were up to 26.14% and 25.31%, respectively. The effect of planting area on trace elements was determined from the aspects of regional distribution and urbanization. Significant differences of essential elements were found between northeast and northwest areas. The urbanization directly influenced toxic elements, which could cause variation up to 85.0% (Pb) and 42.9% (As). Finally, cultivar effect was confirmed that all walnut cultivars were divided into four categories with different trace element characteristics.