Pb speciation and elemental distribution in leeks by micro X-ray fluorescence and X-ray absorption near-edge structure.

Vegetables are crucial to a human diet as they supply the body with essential vitamins, minerals, etc. Heavy metals that accumulate in plants consequently enter the food chain and endanger people's health. Studying the spatial distribution and chemical forms of elements in plant/vegetable tissues is vital to comprehending the potential interactions between elements and detoxification mechanisms. In this study, leek plants and soil from vegetable gardens near lead-zinc mines were collected and cultivated with 500 mg L-1 PbNO3 solutions for three weeks. Micro X-ray fluorescence was used to map the distribution of Pb and other chemical elements in leek roots, and X-ray absorption near-edge spectroscopy was used to assess the Pb speciation in leek roots and leaves. These findings demonstrated that Pb, Cu, Mn, Cr, Ti and Fe were detected in the outer rings of the root's cross section, and high-intensity points were observed in the epidermis. Zn, K and Ca, on the other hand, were distributed throughout the root's cross section. Leek root and leaf contained significant quantities of lead phosphate and basic lead carbonate at more than 80%, followed by lead sulfide (19%) and lead stearate (11.1%). The capacity of leek roots to convert ambient lead into precipitated lead and fix it on the root epidermis and other inner surfaces is a key mechanism for reducing the toxic effects of Pb.

Protective effects of glutamine on lipopolysaccharide/D-galactosamine-induced fulminant hepatitis in mice.

Fulminant hepatitis remains a critical health problem owing to its high mortality rate and the lack of effective therapies. An increasing number of studies have shown that glutamine supplementation provides protective benefits in inflammation-related disorders, but the pharmacological significance of glutamine in lipopolysaccharide (LPS)/D-galactosamine (D-Gal)-induced fulminant hepatitis remains unclear. In the present study, the potential effects of glutamine on LPS/D-Gal-induced fulminant hepatitis were investigated. Pretreatment with glutamine decreased plasma activities of alanine and aspartate aminotransferases, and ameliorated hepatic morphological abnormalities in LPS/D-Gal-exposed mice. Glutamine pretreatment also inhibited LPS/D-Gal-induced tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6) production. In addition, glutamine pretreatment decreased the level of cleaved cysteinyl aspartate-specific proteinase 3 (caspase-3), suppressed the activities of caspase-3, caspase-8, and caspase-9, and reduced the number of cells positive for TdT-mediated dUTP nick-end labeling in LPS/D-Gal-challenged mice. Interestingly, post-treatment with glutamine also provided protective benefits against LPS/D-Gal-induced acute liver injury, although these effects were less robust than those of glutamine pre-treatment. Thus, glutamine may have potential value as a pharmacological intervention in fulminant hepatitis.

Effect of steel slag on ammonia removal and ammonia-oxidizing microorganisms in zeolite-based tidal flow constructed wetlands.

The ammonia removal performance of tidal flow constructed wetlands (TFCWs) requires to be improved under high hydraulic loading rates (HLRs). The pH decrease caused by nitrification may adversely affect the NH4+-N removal and ammonia-oxidizing microorganisms (AOMs) of TFCWs. Herein, TFCWs with zeolite (TFCW_Z) and a mixture of zeolite and steel slag (TFCW_S) were built to investigate the influence of steel slag on NH4+-N removal and AOMs. Both TFCWs were operated under short flooding/drying (F/D) cycles and high HLRs (3.13 and 4.69 m3/(m2 d)). The results revealed that a neutral effluent pH (6.98-7.82) was achieved in TFCW_S owing to the CaO dissolution of steel slag. The NH4+-N removal efficiencies in TFCW_S (91.2 ± 5.1%) were much higher than those in TFCW_Z (73.2 ± 7.1%). Total nitrogen (TN) removal was poor in both TFCWs mainly due to the low influent COD/TN. Phosphorus removal in TFCW_S was unsatisfactory because of the short hydraulic retention time. The addition of steel slag stimulated the flourishing AOMs, including Nitrosomonas (ammonia-oxidizing bacteria, AOB), Candidatus_Nitrocosmicus (ammonia-oxidizing archaea, AOA), and comammox Nitrospira, which may be responsible for the better ammonia removal performance in TFCW_S. PICRUSt2 showed that steel slag also enriched the relative abundance of functional genes involved in nitrification (amoCAB, hao, and nxrAB) but inhibited genes related to denitrification (nirK, norB, and nosZ). Quantitative polymerase chain reaction (qPCR) revealed that complete AOB (CAOB) and AOB contributed more to the amoA genes in TFCW_S and TFCW_Z, respectively. Therefore, this study revealed that the dominant AOMs could be significantly changed in zeolite-based TFCW by adding steel slag to regulate the pH in situ, resulting in a more efficient NH4+-N removal performance.

Enhanced immobilization of uranium(VI) during the conversion of microbially induced calcite to hydroxylapatite.

Carbonate-bound uranium (U) is critical in controlling the migration of U in circumneutral to alkaline conditions. The potential release risk of carbonate-bound U should be concerned due to the contribution of mineral replacement. Herein, we explored the fate of U during the conversion process from microbial-induced calcite to hydroxylapatite (HAP) and investigated the phase and morphology evolution of minerals and the immobilization efficiency, distribution, and stability of U. The results showed that most calcite could convert to HAP during the conversion process. The aqueous residual U was below 1.0 mg/L after U-HAP formation, and the U removal efficiencies were enhanced by 20.0-74.4% compared to the calcite precipitation process. XRD and TEM results showed that the products were a mixture of HAP and uramphite. The elemental mapping results showed that most U concentrated on uramphite while a handful of U distributed homogeneously in calcite and HAP matrixes. The stability test verified that U-bearing HAP decreased the U solubility by 98-100% relative to calcite due to the uramphite formation and U incorporation into HAP. Our findings demonstrated that the combinations of microbial-induced calcite precipitation and calcite-HAP conversion could facilitate the U immobilization in treating radioactive wastewater and soil.

Hyperthermia inhibits growth of nasopharyngeal carcinoma through degradation of c-Myc.

BACKGROUND: Hyperthermia is a widely used adjunct treatment for different cancers including nasopharyngeal carcinoma (NPC). The protooncogene c-Myc is up-regulated in NPC and its expression is associated with poor prognosis. OBJECTIVE: We hypothesized that c-Myc constitutes an important hyperthermia treatment target, and we investigated its contribution to hyperthermia responses in NPC. METHODS: The growth of the human NPC cell lines CNE1 and CNE2 was analyzed using CCK-8 and clonogenicity assays after 43 °C hyperthermia, knockdown or overexpression of c-Myc. Flow cytometry measurements assessed cell cycle parameters and apoptosis, while levels of c-Myc together with key transcriptional targets were determined using qPCR and Western blotting. Parallel experiments were undertaken using NPC xenografts in nude mice and lastly, global transcriptomic changes were determined using 'RNAseq'. RESULTS: Hyperthermia increased the ubiquitination and proteasomal destruction of c-Myc, causing a rapid decline in c-Myc protein levels in NPC cells. Similar to c-Myc knockdown, NPC cells treated with hyperthermia showed growth inhibition associated with the downregulation of c-Myc target genes. Moreover, low levels of c-Myc could be sustainably repressed in NPC cells through repeated hyperthermia treatments. Importantly, the key findings of growth inhibition and decreased c-Myc protein levels were reproduced in NPC tumor xenografts. Bioinformatic analyses showed that downregulation of c-Myc constituted a central node in the hyperthermia response of NPC cells. CONCLUSION: Our study reveals that hyperthermia can readily destabilize c-Myc levels in NPC cells and inhibit tumor growth. This proposes new strategies for implementing hyperthermia to target c-Myc-driven cancers to improve therapeutic efficacy.

In vitro and in vivo highly effective antibacterial activity of carbon dots-modified TiO2 nanorod arrays on titanium.

Light-triggered antibacterial therapy has been proven to be a secure and effective way to treat bacterial infection. Nevertheless, the long-term security of the common photosensitizer remains to be seen in the body. In this work, carbon dots (CDs) with good biocompatibility are incorporated into TiO2 nanorods to improve the photocatalytic and photothermal ability of titanium implants under the irradiation of visible light (VL) and near-infrared (NIR) light. The C-TiO2 NR exhibit excellent in vitro and in vivo antimicrobial effect under 660 nm VL and 808 nm NIR light co-irradiation owing to the combined effect of hyperthermia, reactive oxygen species (ROS) and nanorod structure. Besides, C-TiO2 NR can improve the adhesion and diffusion of bone marrow mesenchymal stem cells (BMSCs).

Near-infrared light II - assisted rapid biofilm elimination platform for bone implants at mild temperature.

Light-triggered therapy is a prospective method to combat implant-associated infection but near-infrared I (NIR-I) light has insufficient penetrating ability in tissues and local hyperthermia induced by the photothermal treatment may destroy surrounding healthy tissues. Herein, a near-infrared II (NIR-II) phototherapy system composed of upconversion elements doped titanium dioxide nanorods (TiO2 NRs)/curcumin (Cur)/hyaluronic acid (HA)/bone morphogenetic protein-2 (BMP-2) is designed for biomedical titanium and demonstrated to overcome the above hurdles simultaneously. Incorporation of F, Yb, and Ho not only improves the photocatalytic ability, but also renders the implants with the upconversion capability, so that the NRs can generate enough reactive oxygen species (ROS) when irradiated by the NIR-II laser. Furthermore, the combined actions of quorum sensing inhibitors, ROS, and physical puncture by NRs eliminate Staphylococcus aureus biofilms on titanium rapidly at a mild temperature of 45 °C by only requiring irradiation with the 1060 nm laser for only 15 min in vitro and in vivo. The presence of Cur mitigates the immune response and BMP-2 improves osteogenic differentiation, thus accelerating new bone formation. This low-temperature NIR-II light-triggered antibacterial platform has large potential in combating deep-tissue infection in clinical applications.

A rose bengal/graphene oxide/PVA hybrid hydrogel with enhanced mechanical properties and light-triggered antibacterial activity for wound treatment.

The numerous advantages of hydrogel make it possible to apply as dressing. However, it is challenging in designing hydrogels with desired antibacterial activity and enhanced mechanical properties at the same time. Herein, a graphene oxide/rose bengal/polyvinyl alcohol hybrid hydrogel (ß-GO/RB/PVA HD) is prepared by freezing and thawing a mixed polyvinyl alcohol (PVA) solution of rose bengal (RB) immobilized with chitosan microspheres (CM) and a modified graphene oxide network (ß-GO). The mechanical properties and light-triggered antibacterial activity of hydrogel are systematically evaluated. The ß-GO inorganic network interpenetrate into the PVA porous structure, which significantly improves the mechanical properties of hydrogel. The hyperthermia generated by ß-GO under 808 nm light irradiation combined with reactive oxygen species (ROS) produced by RB under 550 nm light irradiation give rise to excellent antibacterial activity requiring irradiation for only 10 min as demonstrated by our experiments conducted in vitro and in vivo. Meanwhile, ß-GO/RB/PVA HD exhibits outstanding biocompatibility and water-absorbing capacity. More importantly, the hybrid hydrogel can significantly accelerate bacteria-accompanied wound healing. The results demonstrated that the hybrid hydrogel could be a promising wound dressing for preventing bacterial infection.

Phosphorus regulates As uptake by rice via releasing As into soil porewater and sequestrating it on Fe plaque.

Phosphorus (P) application rate can affect the As uptake by rice, but its mechanism lacks systematic studies. In this study, P fertilizers with different dosages (0, 75, 150, and 300 mg P2O5 kg-1 soil) were used to investigate the effects of P on As release in soil porewater, As sequestration on Fe plaque and the change of abundance and communities of aioA and arsC genes in rhizosphere, and then explore its effect on As uptake by rice. Our results indicated that As content in brown rice under P0 and P75 treatments was 14.3-28.6% lower than that under P150 treatment. The total accumulation of As in brown rice under P0 treatment (1.51 µg plant-1) was significantly lower than that under P150 treatment (2.17 µg plant-1). Compared to P150 treatment, P0 treatment decreased the total As content in porewater but increased the proportion of As(V) to total As in porewater. The activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) in rice roots and the Fe and As contents in Fe plaque were significantly higher under P0 treatment than under P150 treatment. Most of As (80.3-82.9%) sequestered by Fe plaque was in the form of arsenate (As(V)), and the associated As(V) on Fe plaque was 11.0% higher under P0 treatment than under P150 treatment. In addition, the abundance of aioA gene was 73.5% higher under P0 treatment than under P150 treatment, and the dominant aioA at genus level was Rhizobium and Rhodoferax. In general, P0 treatment led to higher root oxidation activity, which improved the formation of Fe plaque; and P0 treatment also improved the abundance of aioA gene in rhizosphere, thus increased the oxidation of As; so, P0 treatment indirectly enhanced As sequestration on Fe plaque, and that in turn reduced As accumulation in brown rice.

The redox behavior of uranium on Beishan granite: Effect of Fe2+ and Fe3+ content.

The Beishan granitic area in Gansu Province is a site with the greatest potential for a repository of high-level radioactive waste (HLW) in China. In this study, the redox behavior of uranium on Beishan granite was investigated at pH values from ~4.4 to ~9.2. Due to the presence of Fe2+-containing fluorannite, results showed that U(VI) was partially reduced by the granites from boreholes 2 (486 m) and 28 (670 m) at a relatively low initial pH whether Na2CO3/NaCl or native groundwater was used as a background electrolyte. Partial oxidation of UO2 was observed when UO2 contacted Beishan granite directly. Therefore, this incomplete reduction of U(VI) was mainly attributed to minor Fe3+ that was either originally contained in the granite or generated during U(VI) reduction. Consequently, aliovalent oxides (e.g., U3O8, U3O7, U4O9, etc.) should be the thermodynamically stable phase in Beishan granite. A mechanism involving the dissolution of Fe2+ from the granite structure followed by interfacial adsorption/reaction was proposed for the U(VI) reduction. This study demonstrates that Beishan granite has a good reducing capacity, which is suitable for the immobilization of redox-sensitive radionuclides. However, potential oxidation of spent fuel by Fe3+ in the granite should also been taken into account.

Dual light-induced in situ antibacterial activities of biocompatibleTiO2/MoS2/PDA/RGD nanorod arrays on titanium.

Prevention of bacterial infection and promotion of osseointegration are two important issues for titanium (Ti) implants in medical research. In addition, after a biofilm is formed on the surface of implants, the immune system and antibiotic therapy may fail. In this work, bio-functionalized titanium dioxide (TiO2)/molybdenum disulfide (MoS2)/polydopamine (PDA)/arginine-glycine-aspartic acid (RGD) nanorod arrays (NAs) are prepared on Ti implants to not only kill bacteria noninvasively upon co-irradiation of 660 nm visible light (VL) and 808 nm near infrared (NIR) light, but also promote the osteogenic activity simultaneously. Dual light irradiation triggers the TiO2/MoS2 NA to generate hyperthermia and reactive oxygen species (ROS) in 10 min. The synergistic effects of the generated hyperthermia and ROS increase the bacterial membrane permeability and bacteria are killed rapidly and efficiently in vitro and in vivo. The biofilm is also eradicated and RGD on the nanorods improves cell adhesion, proliferation, and osteogenic differentiation. The strategy described here for the design of bio-functionalized coatings on Ti implants has great clinical potential in orthopedics, dentistry, and other medical fields.

Are personalized tongxie formula based on diagnostic analyses more effective in reducing IBS symptoms?-A randomized controlled trial.

OBJECTIVES: To examine the efficacy and safety ofpersonalized tongxie formulas; to decrease type II errors to minimum. METHODS: Patients were randomized (1:1:1) into three groups given tongxie, placebo, or pinaverium 3 times daily for 4 weeks. Patients in the tongxie group were treated with personalized formulas based on TCM differential diagnosis, i.e., basic type of IBS, IBS due to liver depression and qi stagnation, excess heat in the liver, deficient spleen function, deficient kidney function, and others (groups 1-6). Primary endpoints were significantly greater reductions in abdominal pain and Bristol stool score. Secondary endpoints were reductions in pain and stool frequencies and abdominal discomfort and its frequency. RESULTS: There were significantly more patients whose stool consistencies were improved than pains were relieved in the entire population (p < 0.001), but there was no significantly difference in subpopulation group 3 (p > 0.05). There were significantly more patients whose stool frequencies were reduced than pain frequencies were reduced in the entire population (p < 0.001), but there were no significantly difference in the subpopulation Groups 1, 3, 4, and 6 (p > 0.05). Multiple active ingredients and their mechanisms of actions to relieve IBS symptoms were identified. CONCLUSION: The outcomes in subpopulations may be different from those of the entire population, indicating that personalized formulas are important to achieve optimal outcomes; the active ingredients and innovative mechanisms identified in this study can be the candidates for developing new IBS drugs, and used to manage IBS, respectively. TRIAL REGISTRATION: NCT01641224 (www.ClinicalTrials.gov).

Tongxie Formula Reduces Symptoms of Irritable Bowel Syndrome.

BACKGROUND & AIMS: Irritable bowel syndrome (IBS) is the most common chronic gastrointestinal disorder, yet few drugs are effective in reducing symptoms. Approximately 50% of patients with IBS attempt herbal therapy at least once. We performed a randomized controlled trial to compare the efficacy of the herb formulation tongxie vs placebo or pinaverium (an antispasmodic agent) in reducing symptoms of IBS. METHODS: We performed a trial of 1044 adult patients with IBS (based on Rome III criteria) at 5 hospitals in China, from August 2012 through January 2015. Subjects were randomly assigned (1:1:1) to groups given tongxie (a combination of A macrocephalae, P lactiflora, C reticulata, S divaricata, C pilosula, C wenyujin, C medica, and P cocos, along with other herbs, based on patient features), placebo, or pinaverium (50 mg tablets) 3 times daily for 4 weeks. Primary end points were significantly greater reductions in abdominal pain and Bristol stool score (before vs after the 4-week study period) in patients given tongxie compared with patients given placebo or pinaverium. Secondary end points were reductions in pain and stool frequencies and abdominal discomfort and its frequency. RESULTS: Subjects given tongxie had significant reductions, before vs after the study period, in all 6 symptoms assessed, compared to patients given placebo (P < .001). A significantly higher proportion of patients given tongxie had increased stool consistency (75.6%) than patients given pinaverium (50.6%), and a significantly higher proportion of patients given tongxie had fewer daily stools (72.7%) than subjects given pinaverium (58.3%) (P < .001 for both). However, significantly higher proportions of patients given pinaverium had reduced pain (63.5%) and pain frequency (69.5%) than patients given tongxie (51.4% and 58.6%, respectively; P < .005 for both). CONCLUSIONS: In a randomized controlled trial of patients with IBS in China, we found 4 weeks of tongxie to produce significantly greater reduction in symptoms than placebo, and greater increases in stool consistency and reductions in stool frequency, than patients given pinaverium. Tongxie can therefore be considered an effective alternative therapy for patients with IBS who do not respond well to conventional therapies. Clinicaltrials.gov no: NCT01641224.

[Standardized investigation on medicinal nature of ethnomedicine].

This article recorded the analysis and comparison between the medicinal nature theory of traditional Chinese medicine(TCM) and ethnomedicine(EM). The vocabulary of "medicinal nature" was suggested to indicate the properties of ethnomedicine. Based on the influence of TCM medicinal nature theory on EM in China, the application of medicinal nature theory in EM was divided into 3 classes, and the standardizing principles for EM medicinal nature were proposed. It was suggested that medicinal quality, flavor, tendency, tropism, degree and efficiency can be used for the classification standard for EM medicinal nature.

Effect of pH on aqueous Se(IV) reduction by pyrite.

Interaction of aqueous Se(IV) with pyrite was investigated using persistently stirred batch reactors under O2-free (<1 ppm) conditions at pH ranging from 4.5 to 6.6. Thermodynamic calculations, an increase in pH during the experiments, and spectroscopic observation indicate that the reduction of aqueous Se(IV) by pyrite is dominated by the following reaction: FeS2+3.5HSeO3−+1.5H+=2SO4(2−)+Fe2++3.5Se(0)+2.5H2O. The released Fe(II) was partitioned between the bulk solution and pyrite surface at pH≈4.5 and 4.8, with the Fe2+ density at pyrite-solution interface about 4 orders of magnitude higher than that in the bulk solution, while iron oxyhydroxide precipitated at pH≈6.6, resulting in the decrease of dissolved iron. In the Se(IV) concentration range of the experiments, aqueous Se(IV) reduction rate follows the pseudofirst order which is in the form of ln mSe(IV)=−k't+ln mSe(IV)0, where k' is apparent rate constant combining the rate constant k and pyrite surface area to mass of solution ratio (A/M). And the aqueous Se(IV) reduction rate constant for a standard system (k) with 1 m2 pyrite surface area per 1 kg solution was obtained to be 1.65×10(−4) h(−1), 3.28×10(−4) h(−1), and 4.76×10(−4) h(−1) at pH around 4.5, 4.8, and 5.1, respectively. The positive correlation between reaction rate and pH disagrees with the theories that protons are consumed when HSeO3− is reduced to Se0, and negative charge density on pyrite surface increases as pH increases. Thus, a ferrous iron mediated electron transfer mechanism is proposed to operate during the reduction of aqueous Se(IV) by pyrite. pH and iron concentration affect significantly on Se(IV) reaction rate and reaction product.