Recurrent stroke shortly after mechanical thrombectomy secondary to carotid web: A case report.

RATIONALE: Carotid web, a known source of thrombus for embolic stroke, presents a considerable risk of stroke recurrence. While case reports have demonstrated the safety and effectiveness of mechanical thrombectomy in treating carotid web-related stroke, the need for concurrent carotid artery stenting to prevent recurrent stroke immediately after thrombectomy remains unclear. This study aims to underscore the importance of immediate carotid artery stenting in preventing recurrent stroke following mechanical thrombectomy in patients with carotid web-related stroke. PATIENT CONCERNS: A 43-year-old woman with acute onset of left limb weakness and slurred speech within 3 hours was admitted to the emergency department. DIAGNOSES: Computed tomographic angiography confirmed the M1 segment occlusion of the right middle cerebral artery. INTERVENTIONS: The patient received intravenous thrombolysis in the local hospital and mechanical thrombectomy in our stroke center. OUTCOMES: Three days post-mechanical thrombectomy, there was a sudden exacerbation of her neurological deficit symptoms. A reexamination via computed tomographic angiography revealed a re-occlusion in M1 segment of the right middle cerebral artery, despite the implementation of stringent anticoagulation therapy for carotid web-related stroke. LESSONS: Stroke patients with carotid web had a high risk of stroke recurrence and it was necessary to conduct carotid artery stenting to prevent stroke recurrence secondary to the carotid web immediately after mechanical thrombectomy.

Cell-specific NFIA upregulation promotes epileptogenesis by TRPV4-mediated astrocyte reactivity.

BACKGROUND: The astrocytes in the central nervous system (CNS) exhibit morphological and functional diversity in brain region-specific pattern. Functional alterations of reactive astrocytes are commonly present in human temporal lobe epilepsy (TLE) cases, meanwhile the neuroinflammation mediated by reactive astrocytes may advance the development of hippocampal epilepsy in animal models. Nuclear factor I-A (NFIA) may regulate astrocyte diversity in the adult brain. However, whether NFIA endows the astrocytes with regional specificity to be involved in epileptogenesis remains elusive. METHODS: Here, we utilize an interference RNA targeting NFIA to explore the characteristics of NFIA expression and its role in astrocyte reactivity in a 4-aminopyridine (4-AP)-induced seizure model in vivo and in vitro. Combined with the employment of a HA-tagged plasmid overexpressing NFIA, we further investigate the precise mechanisms how NIFA facilitates epileptogenesis. RESULTS: 4-AP-induced NFIA upregulation in hippocampal region is astrocyte-specific, and primarily promotes detrimental actions of reactive astrocyte. In line with this phenomenon, both NFIA and vanilloid transient receptor potential 4 (TRPV4) are upregulated in hippocampal astrocytes in human samples from the TLE surgical patients and mouse samples with intraperitoneal 4-AP. NFIA directly regulates mouse astrocytic TRPV4 expression while the quantity and the functional activity of TRPV4 are required for 4-AP-induced astrocyte reactivity and release of proinflammatory cytokines in the charge of NFIA upregulation. NFIA deficiency efficiently inhibits 4-AP-induced TRPV4 upregulation, weakens astrocytic calcium activity and specific astrocyte reactivity, thereby mitigating aberrant neuronal discharges and neuronal damage, and suppressing epileptic seizure. CONCLUSIONS: Our results uncover the critical role of NFIA in astrocyte reactivity and illustrate how epileptogenic brain injury initiates cell-specific signaling pathway to dictate the astrocyte responses.

FIGO recommendations: Use of midurethral slings for the treatment of stress urinary incontinence.

BACKGROUND: Stress urinary incontinence (SUI) is a global problem. It can significantly adversely impact a woman's quality of life. The use of synthetic mesh in vaginal surgery is controversial, especially when used for pelvic organ prolapse surgery. Although negative effects have been reported, the synthetic mesh midurethral sling (MUS) is considered to be safe and effective in the surgical treatment of SUI. OBJECTIVES: To provide evidence-based data and recommendations for the obstetrician/gynecologist who treats women with SUI and performs or plans to perform MUS procedures. METHODS: Academic searches of MEDLINE, the Cochrane Library, Embase, and Google Scholar articles published between 1987 and March 2020 were performed by a subgroup of the Urogynecology and Pelvic Floor Committee, International Federation of Gynecology and Obstetrics (FIGO). SELECTION CRITERIA: The obtained scientific data were associated with a level of evidence according to the Oxford University Centre for Evidence-Based Medicine and GRADE Working Group system. In the absence of concrete scientific evidence, the recommendations were made via professional consensus. RESULTS: The FIGO Urogynecology and Pelvic Floor Committee reviewed the literature and prepared this evidence-based recommendations document for the use of MUS for women with SUI. CONCLUSIONS: Despite the extensive literature, there is a lack of consensus in the optimal surgical treatment of SUI. These recommendations provide a direction for surgeons to make appropriate decisions regarding management of SUI. The MUS is considered safe and effective in the treatment of SUI, based on many high-quality scientific publications and professional society recommendations. Comprehensive long-term data and systemic reviews are still needed, and these data will become increasingly important as women live longer. These recommendations will be continuously updated through future literature reviews.

Toxoplasma gondii Antibodies in Raw Milk and Sera of Cows in China.

Toxoplasma gondii is a worldwide food-borne protozoa that has harmful influences on animal and human health. Raw milk containing T. gondii has been considered as one of the possible infectious sources for humans. Although China is one of the world's leading milk consumers, there is still no study to investigate the seroprevalence of T. gondii in raw cow milk in China; especially for cows in rural areas. Thus, we conducted this study to examine the specific anti-T. gondii IgG-antibody in the raw milk and sera of domestic cows in China. In total, 894 cows were randomly selected from rural areas in northeastern China. The positive rate of T. gondii in the milk and serum samples were 6.38% (57/894) and 7.16% (64/894), respectively. Moreover, a history of abortion (OR = 2.03, 95% CI: 1.11-3.72, p = 0.022) was identified as the only risk factor for T. gondii infection in the studied cows. This study investigated the seroprevalence of T. gondii in the raw milk and sera of cows in China; it provided timely and useful data for public health and food safety, especially in rural areas.

Inhibition of Transient Receptor Potential Vanilloid 4 (TRPV4) Mitigates Seizures.

Astrocytes are critical regulators of the immune/inflammatory response in several human central nervous system (CNS) diseases. Emerging evidence suggests that dysfunctional astrocytes are crucial players in seizures. The objective of this study was to investigate the role of transient receptor potential vanilloid 4 (TRPV4) in 4-aminopyridine (4-AP)-induced seizures and the underlying mechanism. We also provide evidence for the role of Yes-associated protein (YAP) in seizures. 4-AP was administered to mice or primary cultured astrocytes. YAP-specific small interfering RNA (siRNA) was administered to primary cultured astrocytes. Mouse brain tissue and surgical specimens from epileptic patient brains were examined, and the results showed that TRPV4 was upregulated, while astrocytes were activated and polarized to the A1 phenotype. The levels of glial fibrillary acidic protein (GFAP), cytokine production, YAP, signal transducer activator of transcription 3 (STAT3), intracellular Ca2+([Ca2+]i) and the third component of complement (C3) were increased in 4-AP-induced mice and astrocytes. Perturbations in the immune microenvironment in the brain were balanced by TRPV4 inhibition or the manipulation of [Ca2+]i in astrocytes. Knocking down YAP with siRNA significantly inhibited 4-AP-induced pathological changes in astrocytes. Our study demonstrated that astrocytic TRPV4 activation promoted neuroinflammation through the TRPV4/Ca2+/YAP/STAT3 signaling pathway in mice with seizures. Astrocyte TRPV4 inhibition attenuated neuroinflammation, reduced neuronal injury, and improved neurobehavioral function. Targeting astrocytic TRPV4 activation may provide a promising therapeutic approach for managing epilepsy.

A sustainable phosphorus management in agriculture: Assessing trade-offs between human health risks and nutritional yield regarding heavy metals in maize grain.

High-quality products in sustainable agriculture require both limited health risks and sufficient dietary nutrients. Phosphorus (P) as a finite and non-renewable resource is widely used in agriculture, usually exerting influence on the accumulation of heavy metals (HMs) in soil and crops. The present research explores, for the first time, the combined effects of long-term P fertilizer and repeated zinc (Zn) application in field on the human health risks and nutritional yield regarding trace elements in maize grain. A field experiment was conducted using maize with six P application rates (0, 12.5, 25, 50, 100, and 200 kg P ha-1) and two Zn application rates (0 and 11.4 kg Zn ha-1). The results showed that the concentrations of Zn, copper (Cu), and lead (Pb) in the maize grain were significantly affected by P application and can be further affected by Zn application. The concentrations of chromium (Cr) and arsenic (As) showed opposite tendency as affected by P fertilizer rates while did not affected by additional Zn application. Zn application decreased the cadmium (Cd) concentration at high P levels and Pb concentration at low P levels, particularly. No HMs contamination or direct health risk was found in maize grain after receiving long-term P and repeated Zn fertilizer. The threshold hazard quotient of an individual and all investigated HMs in this study were acceptable for human digestion of maize grain. While the carcinogenic risk of Cr was non-negligible in case of maize was taken as one of daily staple food for local residents. Combination use of P (25 kg ha-1) and Zn fertilizer on maize enhanced its nutritional supply ability regarding Zn and Cu, and simultaneously mitigated potential human health risks associated with Cd and Pb.

First detection of anti-Toxoplasma gondii antibodies in domestic goat's serum and milk during lactation in China.

Goat milk is considered as one of the most suitable substitute for human milk, especially for children, the aged and those with cow milk allergies. Consumption of raw or unpasteurized goat milk has been known to be a potential route of Toxoplasma gondii infection for human beings. However, no studies have been carried out to detect T. gondii in goat milk in China. Thus, this stuy was firstly carried out to detect T. gondii IgG antibody in domestic goat's serum and milk during lactation by a commercial validated ELISA kit in China. In total, 10.49% (66/629) serum samples and 9.70% (61/629) milk samples randomly collected from Shandong and Jilin provinces were seropositive for anti-T. gondii IgG, respectively. A high correlation of S/P% value was obtained between serum and milk samples (Spearman's coefficient = 0.891, p-value <0.001 and Kendall's tau = 0.724, p-value < 0.001). Statistical analysis showed that history of abortion, source of water and source of fodder were considered to be highly related to the T. gondii infection in the investigated domestic goats. The present results provide important information for the control and prevention of toxoplasmosis in goats and human beings in China.

Complement C3 Aggravates Post-epileptic Neuronal Injury Via Activation of TRPV1.

Epilepsy is a brain condition characterized by the recurrence of unprovoked seizures. Recent studies have shown that complement component 3 (C3) aggravate the neuronal injury in epilepsy. And our previous studies revealed that TRPV1 (transient receptor potential vanilloid type 1) is involved in epilepsy. Whether complement C3 regulation of neuronal injury is related to the activation of TRPV1 during epilepsy is not fully understood. We found that in a mouse model of status epilepticus (SE), complement C3 derived from astrocytes was increased and aggravated neuronal injury, and that TRPV1-knockout rescued neurons from the injury induced by complement C3. Circular RNAs are abundant in the brain, and the reduction of circRad52 caused by complement C3 promoted the expression of TRPV1 and exacerbated neuronal injury. Mechanistically, disorders of neuron-glia interaction mediated by the C3-TRPV1 signaling pathway may be important for the induction of neuronal injury. This study provides support for the hypothesis that the C3-TRPV1 pathway is involved in the prevention and treatment of neuronal injury and cognitive disorders.

Foliar Zinc Application to Wheat May Lessen the Zinc Deficiency Burden in Rural Quzhou, China.

Zinc (Zn) malnutrition is a common health problem, especially in developing countries. The human health and economic benefits of the replacement of conventional flour with Zn-biofortified wheat flour in rural household diets were assessed. One hundred forty-five wheat flour samples were collected from rural households in Quzhou County. Then, field experiments were conducted on wheat at two Zn levels (0 and 0.4% ZnSO4 · 7H2O foliar application) under 16 diverse agricultural practices in Quzhou County. Foliar Zn application significantly increased the Zn concentration and bioavailability in wheat grain and flour. If rural households consumed Zn-biofortified flour instead of self-cultivated flour or flour purchased from supermarkets, 257-769 or 280-838, 0.46-1.36 million or 0.50-1.49 million disability-adjusted life years (DALYs) lost, respectively, could be saved in Quzhou County and China. Amounts of 2.3-12.0 million and 5.5-22.6 billion RMB could be obtained via Zn-biofortified flour in Quzhou County and China, respectively. The current study indicates that Zn-biofortified flour via foliar Zn application is a win-win strategy to maintain the yield and combat human Zn deficiency in rural households in China. More health and economic benefits could be obtained in rural household dependent on wheat flour purchased from supermarkets than in those dependent on self-cultivated wheat flour.

Advancement and properties of circular RNAs in prostate cancer: An emerging and compelling frontier for discovering.

Prostate cancer (PC) is the most common carcinoma among men worldwide which results in 26% of leading causes of cancer-related death. However, the ideal and effective molecular marker remains elusive. CircRNA, initially observed in plant-infected viruses and Sendai virus in 1979, is generated from pre-mRNA back-splicing and comes in to play by adequate expression. The differential expression in prostate tissues compared with the control reveals the promising capacity in modulating processes including carcinogenesis and metastasis. However, the biological mechanisms of regulatory network in PC needs to systemically concluded. In this review, we enlightened the comprehensive studies on the definite mechanisms of circRNAs affecting tumor progression and metastasis. What's more, we validated the potential clinical application of circRNAs serving as diagnostic and prognostic biomarker. The discussion and analysis in circRNAs will broaden our knowledge of the pathogenesis of PC and further optimize the current therapies against different condition.

Responses in Zinc Uptake of Different Mycorrhizal and Non-mycorrhizal Crops to Varied Levels of Phosphorus and Zinc Applications.

Negative effects of high phosphorus (P) application on zinc (Zn) nutrition have been observed in many crops. This study investigated the Zn responses of three typical crops to varied P and Zn applications. A pot experiment was conducted using two mycorrhizal crops (maize and soybean) and one non-mycorrhizal crop (oilseed rape) under three levels of P, two levels of Zn, and two levels of benomyl. Results showed that P application significantly decreased shoot and root Zn concentrations, Zn uptake, and Zn acquisition efficiency (ZnAE) of the three crops irrespective of Zn rate, and that these reductions were greater for maize and soybean than for oilseed rape. Zn application alleviated the P inhibition of Zn uptake in the three crops. The arbuscular mycorrhizal fungi (AMF) colonization of maize and soybean contributed most to the negative effects of increasing P application on Zn uptake, explaining 79-89 and 64-69% of the effect, respectively. For oilseed rape, root dry weight and root Zn concentration explained 90% of the decrease in Zn uptake caused by P application. These results suggest that there is another pathway in addition to the mycorrhizal pathway regulating Zn uptake under mediation by P supply.

Tetra-benzothiadiazole-based [12]Cycloparaphenylene with Bright Emission and Its Supramolecular Assembly.

The radial conjugated π-system of cycloparaphenylenes (CPPs) makes them intriguing fluorophores and unique supramolecular hosts. However, the bright photoluminescence (PL) of CPPs was limited to the blue light and the supramolecular assembly behavior of large CPPs was rarely investigated. Here we present the synthesis of tetra-benzothiadiazole-based [12]cycloparaphenylene (TB[12]CPP), which exhibits a lime to orange PL with an excellent quantum yield up to 82 % in solution. The PL quantum yield of TB[12]CPP can be further improved to 98 % in polymer matrix. Benefiting from its enlarged size, TB[12]CPP can accommodate a fullerene derivative or concave-convex complexes of fullerene and buckybowl through the combined π-π and C-H⋅⋅⋅π interactions. The latter demonstrates the first case of a ternary supramolecule of CPPs.

The responses of soil enzyme activities, microbial biomass and microbial community structure to nine years of varied zinc application rates.

Zinc (Zn) fertilizer application can certainly improve the production and nutritional quality of cereal crops. However, Zn accumulation in the soil may lead to some deleterious environmental impacts in agroecosystems. The effects of long-term Zn application on soil microbial properties remain unclear, but it is imperative to understand such effects. In this study, we collected soil samples from a nine-year field experiment in a wheat-maize system that continuously received Zn applied at various rates (0, 2.3, 5.7, 11.4, 22.7 and 34.1 kg ha-1) to evaluate the soil enzymes, microbial biomass and microbial community structure. The results showed that Zn application at the rate of 5.7 kg ha-1 significantly increased the activities of urease, invertase, alkaline phosphatase and catalase in the soil, while the rate of 34.1 kg ha-1 significantly decreased the evaluated enzyme activities. The microbial biomass carbon (C) and nitrogen (N) were not affected by Zn application rates, although an increase in the microbial biomass C was observed in the 11.4 kg ha-1 treatment. Moreover, the alpha diversity of the bacterial and fungal communities did not vary among the nil Zn, optimal Zn (5.7 kg ha-1) and excess Zn (34.1 kg ha-1) treatments. However, the bacterial communities in the soil receiving the optimal and excess Zn application rates were slightly changed. Compared to the nil Zn treatment, the other Zn application rates increased the relative abundances of the Rhodospirillales, Gaiellales and Frankiales orders and decreased the abundance of the Latescibacteria phylum. The redundancy analysis further indicated that the soil bacterial community composition significantly correlated with the concentrations of soil DTPA-Zn and total Zn. These results highlight the importance of optimal Zn application in achieving high production and high grain quality while concurrently promoting soil microbial activity, improving the bacterial community and further maintaining the sustainability of the agroecological environment.

MicroRNA-708 prevents ethanol-induced hepatic lipid accumulation and inflammatory reaction via direct targeting ZEB1.

Alcoholic liver disease (ALD) was a global liver disease which divided into liver inflammation, fatty liver, alcoholic hepatitis or cirrhosis. Abnormal expression levels of some microRNAs (miRNA) family members often lead to ALD and other liver diseases. MicroRNA-708 (miR-708) was known to suppress the proliferation and metastasis of hepatocellular carcinoma (HCC), but its role in the progression of ALD was not clear. In this study, the expression level of miR-708 was down-regulated in ethanol-induced L0-2 cells. ZEB1 could decrease the PPAR-α expression while increase the SREBP-1 expression. Meanwhile, the expression levels of TNF-α and IL-6 were up-regulated by ZEB1. Of note, ZEB1 aggravated the apoptotic rate of L0-2 cells induced by ethanol via inhibiting p-AKT and p-mTOR of AKT/mTOR signaling pathway. What's more, it was demonstrated that miR-708 family members particularly target ZEB1 3'-UTR regions and can down-regulate the expression level of ZEB1 in L0-2 cells. Sum up, these results indicated that miR-708 might inhibit the liver inflammation and lipid accumulation by targeting ZEB1 via regulating AKT/mTOR signaling pathway.

The regeneration of Acer rubrum L. "October Glory" through embryonic callus.

BACKGROUND: Tissue culture and rapid propagation technology is an important way to solve the difficulties of plant propagation. This experiment aims to explore the appropriate conditions at each stage of the red maple's tissue culture process and to obtain plantlets, thus providing a theoretical basis for the establishment of the red maple's tissue culture system. RESULTS: The results showed that the stem segment is the most suitable explant for inducing embryogenic callus. The MS (Murashige&Skoog) + 0.8 mg/L TDZ (Thidiazuron) + 1.0 mg/L 6-BA (6-Benzylaminopurine) + 0.5 mg/L IAA(Indole-3-acetic acid) + 35 g/L sucrose+ 7.5 g/L semi-fixed medium was the best for callus formation. When selecting type VI callus as embryonic callus induction material, MS + 0.6 mg/L TDZ + 0.5 mg/L 6-BA + 2.0 mg/L IAA + 35 g/L sucrose+ 7.5 g/L semi-fixed medium can get embryonic callus. The optimal medium for adventitious bud induction is MS + 1.0 mg/L TDZ + 3.0 mg/L 6-BA+ 0.2 mg/L NAA (1-Naphthaleneacetic acid) + 1.2 mg/L IAA + 35 g/L sucrose+ 7.5 g/L semi-fixed medium. The induction rate of adventitious roots in MS + 0.6 mg/L TDZ + 1.0 mg/L 6-BA+ 3 mg/L NAA + 35 g/L sucrose+ 7.5 g/L semi-fixed medium was the highest, reaching 76%. CONCLUSIONS: In the course of our research, we found that PGRs play an important role in the callus induction stage, and the effect of TDZ is particularly obvious; The callus cells grow and proliferate according to the "S" growth curve, and can be sub-cultured when the highest growth point is reached to maintain the rapid proliferation of the callus cells and to avoid inactivation of callus caused by tight niche.

TMEM88 modulates the secretion of inflammatory factors by regulating YAP signaling pathway in alcoholic liver disease.

OBJECTIVE: Transmembrane protein 88 (TMEM88), a new protein of increasing concern existed in cell membrane, inhibits the typical Wnt/ß-catenin signaling pathway to play a regulatory role on cell proliferation by binding to Dishevelled-1. Until recently, the connection between TMEM88 and alcoholic liver disease is unknown. In this research, we explored the effect of TMEM88 on the secretion of inflammatory cytokines in ethanol (EtOH)-induced RAW264.7 cells, moreover, the function of YAP signaling pathway in EtOH-induced RAW264.7 cells were investigated. METHODS: We administered TMEM88 adenovirus (ADV-TMEM88) by tail vein injection into C57BL/6J mice in vivo. In vitro, RAW264.7 murine macrophages were stimulated with EtOH and were transfected with pEGFP-C1-TMEM88 and TMEM88 siRNA, respectively, protein expression and mRNA expression of IL-6 and IL-1ß were assessed by Western Blotting and RT-qPCR, respectively. RESULTS: Our group found that the overexpression of TMEM88 led to an up-regulation of IL-6 and IL-1ß secretion, hinting that it had the possibility of linking with the initiation, the development, and the end of inflammation. In addition to that, TMEM88 silencing reduced the secretion of IL-6 and IL-1ß in RAW264.7 cells. Moreover, we demonstrated that the YAP signaling pathway under the action of EtOH was activated by TMEM88. CONCLUSIONS: All in all, these experimental outcomes indicated that TMEM88 had an indispensable impact on EtOH-induced secretion of inflammatory cytokines (IL-6 and IL-1ß) in RAW264.7 cells through YAP signaling pathway.

Molecular defect-containing bilayer graphene exhibiting brightened luminescence.

The electronic structure of bilayer graphene can be altered by creating defects in its carbon skeleton. However, the natural defects are generally heterogeneous. On the other hand, rational bottom-up synthesis offers the possibility of building well-defined molecular cutout of defect-containing bilayer graphene, which allows defect-induced modulation with atomic precision. Here, we report the construction of a molecular defect-containing bilayer graphene (MDBG) with an inner cavity by organic synthesis. Single-crystal x-ray diffraction, mass spectrometry, and nuclear magnetic resonance spectroscopy unambiguously characterize the structure of MDBG. Compared with its same-sized, defect-free counterpart, the MDBG exhibits a notable blue shift of optical absorption and emission, as well as a 9.6-fold brightening of its photoluminescence, which demonstrates that a single defect can markedly alter the optical properties of bilayer graphene.

Soil Application of Zinc Fertilizer Increases Maize Yield by Enhancing the Kernel Number and Kernel Weight of Inferior Grains.

Improving the development of inferior grains is important for increasing maize yield under high-density conditions. However, the effect of micronutrients, especially zinc (Zn), on the development of inferior grains and maize yield under field conditions has not been evaluated to date. A field experiment with six Zn application rates (0, 2.3, 5.7, 11.4, 22.7, and 34.1 kg/ha) was conducted to investigate the effects of soil application of Zn fertilizer on the development of inferior grains. Pollen viability was measured at the tasseling stage. The maize spike was divided into apical (inferior grain), middle, and basal sections for further measurement at harvest. Results showed that soil application of Zn fertilizer increased maize yield by 4.2-16.7% due to increased kernel number and weight in the apical, but not in the middle and basal sections. Zn application also significantly increased pollen viability at the tasseling stage. The critical Zn concentrations in shoots at the tasseling stage for obtaining high pollen viability and high kernel numbers of inferior grains were 31.2 and 35.6 mg/kg, respectively. Zn application also increased the 1,000-kernel weight of inferior grain due to high biomass accumulation. Furthermore, the grain Zn concentration of inferior grain with Zn application increased by 24.3-74.9% compared with no Zn application. Thus, soil application of Zn fertilizer successfully increased grain yield of maize by improving pollen viability, kernel number, and kernel weight of inferior grains (apical section), also contributing to grain Zn biofortification.

Health risk assessment associated with heavy metal accumulation in wheat after long-term phosphorus fertilizer application.

Phosphorus (P) fertilizer is widely used to increase wheat yield. However, it remains unclear whether prolonged intake of wheat grain that received long-term P application may promote human health risks by influencing heavy metal(loid)s (HMs) accumulation. A 10-year field experiment was conducted to evaluate the effects of continuous P application (0, 25, 50, 100, 200, and 400 kg P ha-1) on human health risks of HMs, including zinc (Zn), copper (Cu), cadmium (Cd), lead (Pb), arsenic (As), nickel (Ni), and chromium (Cr), by ingesting wheat grain. The results showed that P application facilitated Zn, Pb, Cd, and As accumulation in the topsoil. The Zn, Cu, Pb, and Ni concentrations in grain were decreased, while Cd and As were increased by P application. All HMs concentrations of both soil and grain were in the ranges of corresponding safety thresholds at different P levels. The accumulation abilities of Zn, Cu, Pb, and Ni from soil and straw to grain were suppressed by P addition while of As was enhanced. There was no significant difference in the hazard index (HI) of the investigated HMs in all treatments except 25 kg ha-1. The threshold cancer risk (TCR) associated with As and Cd was enhanced, while that of Pb was alleviated as P application increased. Behaviors of Cr from soil to wheat and to humans were not affected by P application. Phosphorus application at a rate of 50 kg ha-1 decreased total non-cancer and cancer risks by 15% and 21%, respectively, for both children and adults, compared to the highest value. In conclusion, long-term optimal application of 50 kg P ha-1 to wheat did not result in additional adverse effects on the total non-carcinogenic or carcinogenic risk caused by the studied HMs to humans through the ingestion of wheat grain.

Health risk assessment of heavy metals (Zn, Cu, Cd, Pb, As and Cr) in wheat grain receiving repeated Zn fertilizers.

Soil application of Zn fertilizer is an effective approach to improve yield and Zn accumulation in wheat grain. However, it remains unclear whether repeated Zn application can result in high accumulation of heavy metals (HMs) in soils and grains and thus represents a potential risk for human consumption. This study aimed to evaluate the health risk assessment of HMs in a wheat production system which had continuously received 8 years of Zn application at varying rates (0, 2.3, 5.7, 11.4, 22.7, 34.1 kg Zn ha-1). The results showed that Zn application significantly increased the soil total Zn concentration without affecting concentrations of As, Pb, Cd, Cu and Cr. Across Zn rates, Zn application increased grain concentrations of Zn, Pb and Cd by 75%, 51% and 14%, respectively, and reduced grain As concentration by 14%. The human health risk assessment revealed that the threshold hazard quotients for the individual HM were below 1, independent of Zn rates. The hazard index (HI) values at Zn rates of 11.4, 22.7 and 34.1 kg Zn ha-1 were significantly greater than that at null Zn treatment. Furthermore, exposures to As, Cu and Zn accounted for 97% of HI at all Zn rates. Analysis of the threshold cancer risk with Pb and As showed that ingestion of wheat grain even from highest Zn application rate wouldn't bring the lifetime carcinogenic risk. In contrast, long-term Zn application significantly reduced the carcinogenic risk of As by 9.7-26.5%. In conclusion, repeated soil applications of Zn at optimal rate (5.7 kg Zn ha-1) didn't cause health risk for Zn, Cu, Cd, Pb, Cr, and As, while improving productivity and grain Zn concentration of wheat to meet human recruitment. Our study highlights the importance of appropriate Zn fertilizer management in improving grain quality while reducing HMs risks from human consumption.