Preoperative prediction for early recurrence of hepatocellular carcinoma using machine learning-based radiomics.

Objective: To develop a contrast-enhanced computed tomography (CECT) based radiomics model using machine learning method and assess its ability of preoperative prediction for the early recurrence of hepatocellular carcinoma (HCC). Methods: A total of 297 patients confirmed with HCC were assigned to the training dataset and test dataset based on the 8:2 ratio, and the follow-up period of the patients was from May 2012 to July 2017. The lesion sites were manually segmented using ITK-SNAP, and the pyradiomics platform was applied to extract radiomic features. We established the machine learning model to predict the early recurrence of HCC. The accuracy, AUC, standard deviation, specificity, and sensitivity were applied to evaluate the model performance. Results: 1,688 features were extracted from the arterial phase and venous phase images, respectively. When arterial phase and venous phase images were employed correlated with clinical factors to train a prediction model, it achieved the best performance (AUC with 95% CI 0.8300(0.7560-0.9040), sensitivity 89.45%, specificity 79.07%, accuracy 82.67%, p value 0.0064). Conclusion: The CECT-based radiomics may be helpful to non-invasively reveal the potential connection between CECT images and early recurrence of HCC. The combination of radiomics and clinical factors could boost model performance.

Self-Healing of Poly(vinyl Alcohol)/Poly(acrylic Acid)-Polytetrahydrofuran-Poly(acrylic Acid) Blend Boosted via Shape Memory.

The self-healable polymers that can repair physical damage autonomously to extend their lifetime and reduce maintenance costs are promising intelligent materials. However, utilizing shape memory to facilitate self-repair is unusual at present. In this work, a series of poly(acrylic acid)-polytetrahydrofuran-poly(acrylic acid) polymers (PAA-PTMG-PAA, diPAA-PTMG) are synthesized as a switching phase and healing accelerator to blend into poly(vinyl alcohol) (PVA). The water swelling rate of the blend is up to 400.0% at 1/1 molecular weight ratio of PTMG/PAA and 20.0 wt % blend ratio of diPAA-PTMG to PVA, and its crystallization is changed significantly under wet conditions. The blend membrane exhibits not only a good hydrothermal-response shape memory effect but also a favorable self-healing behavior. The tensile strength and elongation at break are 12.4 MPa and 320.0% after healing at 25 °C, respectively. In particular, the wound membrane can achieve a better self-healing effect with the assistance of shape memory at 37 °C, and the elongation at the break increased to 515.9% after healing. The membrane is not cytotoxic, so it will be a promising biomedical material.

Comprehensive analysis of the prognosis of S100 family members and their relationship with tumor-infiltrating immune cells in human pancreatic adenocarcinoma.

S100 family members (S100s) are small molecular EF hand calcium binding proteins and widely expressed in many tissues and organs. S100s are shown to be biomarkers of disease progression and prognosis in various types of cancers. Nevertheless, the expression patterns, function, and prognostic values of S100s and its association with tumor-infiltrating immune cells in pancreatic adenocarcinoma (PAAD) patients have not been systematically clarified. We explored the expression and roles of the entire 20 S100s in PAAD patients by using the following public databases: Oncomine, gene expression profiling interactive analysis, cBioPortal, Metascape, search tool for recurring instances of neighboring genes, Tumor IMmune Estimation Resource, and GeneMANIA. The S100A2/A3/A4/A6/A8/A9/A10/A11/A13/A14/A16/B/P mRNA expressions were significantly upregulated in PAAD patients. The mRNA expression of S100A3/A4/A5/A6/A10/A11/A14/A16/Z were significantly negatively related with the tumor stage in PAAD patients. We found that the S100A2/A3/A5/A10/A11/A14/A16 were significantly correlated with poor overall survival, whereas the increased levels of S100A1/B/G/Z were strongly associated with good overall survival. We found significant correlations among S100s and tumor-infiltrating immune cells. Cox proportional risk models revealed that B cells, Dendritic cells and S100A1/A5/A6/A8/A9/A13/A14 were significantly related with outcomes in PAAD patients. These results suggest that S100A2/A3/A10/A11/A14/A16 may serve as new diagnostic and prognostic biomarkers for PAAD patients and provide new clues for immunotherapy in PAAD patients.

Distinct Prognostic and Immunological Roles of ETS1 and ETS2: A Pan-Cancer Analysis.

Objective: ETS1 and ETS2, the main ETS family of transcription factors, have been found to act as downstream effectors of the RAS/MAPK pathway. This study explores the expression and prognostic values of ETS1 and ETS2 across cancers. We also aimed to explore the significance of ETS1 and ETS2 expression in normal immune cells with relation to tumorigenesis. Methods: The expression of ETS1 and ETS2 was examined in the HPA and GEPIA2 databases. The KM plotter was applied to examine prognostic value of ETS1 and ETS2. Correlation between ETS1/ETS2 and infiltrating immune cells and immune checkpoints was assessed using TIMER2.0. The mutation landscape of ETS1/ETS2 was explored using the cBioPortal. STRING and GEPIA2 were used to screen ETS1/ETS2 binding and correlated genes. Enrichr was applied to perform GO and KEGG enrichment analyses. Results: ETS1 showed enhanced expression in lymphoid tissue, while ETS2 showed low tissue specificity. ETS1 was increased in 12 and decreased in 6 cancers, while ETS2 was increased in 4 and decreased in 13 cancers. Both ETS1 and ETS2 were favorable prognostic markers in LIHC and KIRC, while they showed different prognostic roles in more cancers. ETS1 showed stronger correlation with several infiltrating immune cells and immune checkpoints compared with ETS2. Both ETS1 and ETS2 harbored low mutation ratio. ETS1 interacting and correlated genes were enriched in GO terms in response to cadmium ion and response to oxidative stress, while those of ETS2 were enriched in transcription regulation. Conclusion: ETS1 and ETS2 showed different patterns in expression, prognostic values, correlation with immune infiltrating, and immune checkpoints. ETS1 and ETS2 play distinct roles across cancer.

Toxicity of Bacillus thuringiensis Strains Derived from the Novel Crystal Protein Cry31Aa with High Nematicidal Activity against Rice Parasitic Nematode Aphelenchoides besseyi.

The plant parasitic nematode, Aphelenchoides besseyi, is a serious pest causing severe damage to various crop plants and vegetables. The Bacillus thuringiensis (Bt) strains, GBAC46 and NMTD81, and the biological strain, FZB42, showed higher nematicidal activity against A. besseyi, by up to 88.80, 82.65, and 75.87%, respectively, in a 96-well plate experiment. We screened the whole genomes of the selected strains by protein-nucleic acid alignment. It was found that the Bt strain GBAC46 showed three novel crystal proteins, namely, Cry31Aa, Cry73Aa, and Cry40ORF, which likely provide for the safe control of nematodes. The Cry31Aa protein was composed of 802 amino acids with a molecular weight of 90.257 kDa and contained a conserved delta-endotoxin insecticidal domain. The Cry31Aa exhibited significant nematicidal activity against A. besseyi with a lethal concentration (LC50) value of 131.80 µg/mL. Furthermore, the results of in vitro experiments (i.e., rhodamine and propidium iodide (PI) experiments) revealed that the Cry31Aa protein was taken up by A. besseyi, which caused damage to the nematode's intestinal cell membrane, indicating that the Cry31Aa produced a pore-formation toxin. In pot experiments, the selected strains GBAC46, NMTD81, and FZB42 significantly reduced the lesions on leaves by up to 33.56%, 45.66, and 30.34% and also enhanced physiological growth parameters such as root length (65.10, 50.65, and 55.60%), shoot length (68.10, 55.60, and 59.45%), and plant fresh weight (60.71, 56.45, and 55.65%), respectively. The number of nematodes obtained from the plants treated with the selected strains (i.e., GBAC46, NMTD81, and FZB42) and A. besseyi was significantly reduced, with 0.56, 0.83., 1.11, and 5.04 seedling mL-1 nematodes were achieved, respectively. Moreover, the qRT-PCR analysis showed that the defense-related genes were upregulated, and the activity of hydrogen peroxide (H2O2) increased while malondialdehyde (MDA) decreased in rice leaves compared to the control. Therefore, it was concluded that the Bt strains GBAC46 and NMTD81 can promote rice growth, induce high expression of rice defense-related genes, and activate systemic resistance in rice. More importantly, the application of the novel Cry31Aa protein has high potential for the efficient and safe prevention and green control of plant parasitic nematodes.

A drug-loaded amphiphilic polymer/poly(l-lactide) shape-memory system.

Biodegradable shape-memory polymers (SMPs) which are functional materials with applicability for medicine devices are designed to acquire their therapeutically relevant shape and drug release after implantation. In the work, an amphiphilic polymer (PVAD) is synthesized by using polytetrahydrofuran (PTMG), vinyl acetate (VAc), acrylic acid (AA), tetramethyltetravinylcyclotetrasiloxane (D4vi) as raw materials. PVAD encapsulating hydrophilic drug as switching phase and poly(l-lactide) (PLLA) as fixing matrix construct an SM system with the characteristic of "reservoir-matrix" drug release. The shape recovery ratio (Rr) of medicated PVAD/PLLA reaches 99 % by heat-water stimulation. The effects of release temperature and SM on drug release are investigated. With the release temperature increasing, the medicated PVAD/PLLA accelerates drug release and shows burst release initially, while the drug release for the medicated PLLA changes slightly. The drug release rate goes up after 3 rounds of SM. The mechanism of SM system controlling drug release is put forward based on structural changes. The yield strength and elongation at break of medicated PVAD/PLLA are 29.8 MPa and 44.6 %, respectively. It opens up new perspectives for drug carrier matrices in Pharmaceutical Sciences.

Circular RNA hsa_circ_0068252 Functions in Cisplatin Resistance and Immune Response via miR-1304-5p/PD-L1 Axis in Non-Small Cell Lung Cancer.

BACKGROUND: Research suggests that circRNAs play important roles in non-small cell lung cancer (NSCLC). The function of hsa_circ_0068252 in NSCLC, especially in cisplatin (DDP) resistance and the mechanisms, was explored in this study. METHODS: NSCLC patient samples and two NSCLC cell lines along with corresponding DDP-resistant cell lines were used. Expression levels of circ_0068252 were detected. SiRNA for circ_0068252 and inhibitor for miRNA were used in all functional analyses. A co-culture system of NSCLC cells with CD8+ T cells was used. The cellular location of circ_0068252 was detected and its target miRNA was predicted and verified. Finally, the mechanism responsible for circ_0068252 function on PD-L1 was analyzed using luciferase reporter assay in the two DDP-resistant cell lines, as well as in the co-culture system. The cytotoxicity of T cells was detected by lactate dehydrogenase assay. RESULTS: Our findings revealed that a high level of circ_0068252 was correlated with poor prognosis of NSCLC and DDP resistance. Knockdown of circ_0068252 could promote the sensitivity of DDP-resistant NSCLC cells to DDP. Moreover, knockdown of circ_0068252 could regulate the immune microenvironment which was mediated via CD8+ T cells. Finally, circ_0068252 could up-regulate PD-L1 expression by adsorbing miR-1304-5p. CONCLUSION: The circ_0068252/miR-1304-5p/PD-L1 signal axis participates in the regulation of DDP resistance and immune escape of NSCLC cells. Our results suggest that circ_0068252 may be a potential diagnostic marker and therapeutic target for DDP-resistant NSCLC.

Preparation, characterization, and antibacterial activity of tigecycline-loaded, ultrasound-activated microbubbles.

Central nervous system infectious disease caused by the multidrug-resistant Acinetobacter baumannii (AB) seriously threatens human life in clinic. Tigecycline has good sensitivity in killing AB, but due to its wide tissue distribution and blood-brain barrier, concentration in cerebrospinal fluid is low, therefore, the clinical effect is limited. Herein, we designed micro-bubbled tigecycline, aimed to enhance its anti-MDRAB effects under ultrasound. The lipid microbubbles with different ratios of lipids to drugs (a ratio of 10:1, 20:1, and 40:1) were prepared by the mechanical shaking method. The morphology, zeta potential and particle size of microbubbles were tested to screen out the much better formulation. Encapsulation efficiency and drug loading amount were determined by ultracentrifugation combined with high-performance liquid chromatography. Then the in vitro antibacterial activity against AB was conducted using the selected ultrasound-activated microbubble. Results showed the selected microbubbles with high encapsulation efficiency and good stability. The mechanical shaking method is feasible for preparation of drug-loaded and ultrasound-activated lipid microbubbles. Using 0.2 mg/mL microbubbles, combined with 1 MHz, 2.5 W/cm2 and 1 min of ultrasound exhibited a potent anit-AB in vitro. This study indicates that tigecycline treatment in form of ultrasound-activated microbubble is a promising strategy against AB infections.

Adsorption and Desorption Behaviors of Spirotetramat in Various Soils and Its Interaction Mechanism.

Spirotetramat is a pesticide with bidirectional systemicity and can effectively control pests by inhibiting the biosynthesis of fatty acids. In this study, adsorption and desorption behaviors of spirotetramat in six soils and its interaction mechanism were studied using the batch equilibrium method and infrared radiation. The results showed that the adsorption and desorption behaviors of spirotetramat conformed to the Freundlich isotherm model. The values of adsorption capacities KF-ads ranged from 2.11 to 12.40, and the values of desorption capacities KF-des varied from 2.97 to 32.90. From the hysteresis coefficient, spirotetramat was easily desorbed from the test soils. The adsorption capacity of the soil to spirotetramat enhanced with an increasing temperature. Moreover, the changes in pH values and exogenous addition of humic acid and surfactant could also affect soil adsorption capacity, but for desorption, there was no correlation.

Determination and Safety Assessment of Residual Spirotetramat and Its Metabolites in Amaranth (Amaranthus tricolor) and Soil by Liquid Chromatography Triple-Quadrupole Tandem Mass Spectrometry.

With the purpose of guaranteeing the safe use of spirotetramat and preventing its potential health threats to consumers, a QuEChERS extraction method coupled with LC triple-quadrupole tandem MS was applied in this study to determine residual spirotetramat metabolites in different tissues of amaranth (Amaranthus tricolor) and in soil. The results indicate that the spirotetramat degraded into different types of metabolites that were located in different tissues of amaranth and in soil. B-keto, B-glu, and B-enol were the three most representative degradation products in the leaf of amaranth, and B-glu and B-enol were the two major degradation products found in the stem of amaranth; however, only B-enol was detected in the root of amaranth. B-keto and B-mono were the two products detected in the soil in which the amaranth grew. The cytotoxicity results demonstrate that spirotetramat and its metabolite B-enol inhibited cellular growth, and the toxicity of spirotetramat and its metabolite B-enol exceeded than that of the metabolites B-keto, B-mono, and B-glu. This investigation is of great significance to the safe use of spirotetramat in agriculture.

Transfer of CD11c+ lamina propria mononuclear phagocytes from post-infectious irritable bowel syndrome causes mucosal barrier dysfunction and visceral hypersensitivity in recipient mice.

The role of low-grade inflammation in the development of post­infectious irritable bowel syndrome (PI­IBS) has attracted increasing attention. Abnormal CD11c+ mononuclear phagocytes, such as dendritic cells (DCs), macrophages, and monocytes, are involved in the disruption of immune tolerance in organisms, which can lead to the development of chronic inflammatory diseases. The present study tested the hypothesis that CD11c+ lamina propria mononuclear phagocytes (CD11c+ LPMPs) contribute to increased mucosal permeability and visceral hypersensitivity in a PI­IBS mouse model. CD11c+ LPMPs were isolated and purified via the digestion of intestinal tissues and magnetic­activated cell sorting. We detected increased mucosal permeability, visceral hypersensitivity and intestinal inflammation during both the acute and chronic stages of Trichinella infection. Following the transfer of CD11c+ LPMPs from PI­IBS mice into normal mice, low­grade inflammation was detected, as demonstrated by increased IL­4 expression in the ileum, as well as enhanced mucosal permeability, as indicated by decreased transepithelial electrical resistance and the pre-sence of ultrastructural alterations. More importantly, the mice that underwent adoptive transfer of CD11c+ LPMPs from the PI­IBS mice also exhibited increased abdominal withdrawal reflex scores and a decreased threshold. Our data demonstrated that the CD11c+ LPMPs from this PI­IBS mouse model were not only able to transfer enteric inflammation to the normal mice but also caused abnormal intestinal function, characterized by epithelial barrier disruption and visceral hyperalgesia.

Expression of ß-catenin protein in hepatocellular carcinoma and its relationship with alpha-fetoprotein.

This study aimed to investigate the expression of ß-catenin in hepatocellular carcinoma (HCC) tissues and its relationship with α-fetoprotein (AFP) in HCC. Immunohistochemistry was used to determine the expression of ß-catenin in normal liver tissues (n=10), liver cirrhosis tissues (n=20), and primary HCC tissues (n=60). The relationship between ß-catenin expression and clinical parameters of HCC was investigated. Real-time PCR and Western blotting were used to detect the mRNA and protein expression levels of ß-catenin in the liver cancer cell line SMMC-7721 transfected with a plasmid encoding AFP, and also the mRNA and protein expression levels of ß-catenin were measured in the liver cancer cell line Huh7 before and after the transfection with AFP shRNA plasmids. The results showed that ß-catenin was only expressed on the cell membrane in normal liver tissues. Its localization to the cytoplasm and nucleus of cells was observed in a small proportion of cirrhotic tissues or adjacent HCC tissues, and such ectopic expression of ß-catenin was predominant in HCC tissues. The abnormal expression of ß-catenin was correlated with serum AFP levels, cancer cell differentiation and vascular invasion (P<0.05). Additionally, the increased expression of AFP resulted in the upregulation of ß-catenin mRNA and protein levels, while knockdown of AFP with AFP shRNA led to significantly decreased ß-catenin mRNA and protein levels (P<0.05). It was suggested that the abnormal expression of ß-catenin is implicated in hepatic carcinogenesis and development. AFP can lead to increased expression of ß-catenin, which may account for the poor prognosis of AFP-associated HCC patients.

Synthesis and characterization of tannin grafted polycaprolactone.

Tannin and biodegradable polyester have attracted increasing interest for biomedical applications. To improve their compatibility, a novel tannin grafted polycaprolactone (TA-g-PCL) has been synthesized via ring-opening polymerization reaction. The structure of the product is characterized with FTIR, (1)H NMR and GPC. GPC results show that the experimental molecular weight is far less than the theoretical due to complicated stereo structure and large steric hindrance of tannic molecule, but the polydispersity of the product is narrow. At 115.76:1 of molar ratio of CL to tannin, molecular weight of the product reaches the maximum. Thermodynamics properties and dissolubility of TA-g-PCL are closely related to its molecular weight. With PCL molecular chain grows, TA-g-PCL changes from amorphous form to crystalline structure, and its dissolubility in chloroform is also enhanced significantly.

A novel technique of unilateral percutaneous kyphoplasty achieves effective biomechanical strength and reduces radiation exposure.

PURPOSE: To develop a novel technique of percutaneous kyphoplasty (PKP) with effective biomechanical strength and lower radiation exposure. METHODS: Thirty fresh lumbar vertebrae isolated from six hogs were decalcified and compressed to induce osteoporotic vertebral compression fractures. Kyphoplasty was performed using three different techniques (ten for each group): conventional unilateral approach (group A), conventional bilateral approach (group B) and novel unilateral approach (group C). Biomechanical indexes including Yield load and stiffness were tested before and after kyphoplasty. The anterior height of each vertebral body (AHVB) was measured before compression, after compression and after kyphoplasty. Frequency of C-arm use and volume of bone cement were also recorded in the process. RESULTS: Compared with group A, our novel technique in group C can significantly improve the recovery of AHVB after compression fractures. However, there was no statistical difference between group B and group C. Values of Yield load in both group B and group C were statistically higher than that in group A, however, no significant difference was found between group B and C. Statistical results of stiffness were similar to Yield load. Regarding volume of bone cement and radiation exposure, the novel technique in group C needed more bone cement and fluoroscopy use than in group A but less than in group B. CONCLUSIONS: This novel device makes unilateral kyphoplasty feasible, safe and effective. In the premise of guaranteed biomechanical strength, the new technique significantly reduces risk of radiation exposure in kyphoplasty.

Degradation kinetics and pathways of spirotetramat in different parts of spinach plant and in the soil.

Spirotetramat is a new pesticide against a broad spectrum of sucking insects and exhibits a unique property with a two-way systemicity. In order to formulate a scientific rationale for a reasonable spray dose and the safe interval period of 22.4 % spirotetramat suspension concentrate on controlling vegetable pests, we analyzed degradation dynamics and pathways of spirotetramat in different parts of spinach plant (leaf, stalk, and root) and in the soil. We conducted experimental trials under field conditions and adopted a simple and reliable method (dispersive solid phase extraction) combined with liquid chromatography-triple quadrupole tandem mass spectrometry to evaluate the dissipation rates of spirotetramat residue and its metabolites. The results showed that the spirotetramat was degraded into different metabolite residues in different parts of spinach plant (leaf, stalk, and root) and in the soil. Specifically, spirotetramat was degraded into B-keto, B-glu, and B-enol in the leaf; B-glu and B-enol in the stalk; and only B-enol in the root. In the soil where the plants grew, spirotetramat followed a completely different pathway compared to the plant and degraded into B-keto and B-mono. Regardless of different degradation pathways, the dissipation dynamic equations of spirotetramat in different parts of spinach plant and in the soil were all based on the first-order reaction dynamic equations. This work provides guidelines for the safe use of spirotetramat in spinach fields, which would help prevent potential health threats to consumers.

A switchable dual organocatalytic system and the enantioselective total synthesis of the quadrane sesquiterpene suberosanone.

The combination of aminocatalysis with N-heterocyclic carbene catalysis has been extended to a switchable dual catalytic system, which allowed a direct enantioselective entry to bridged bicyclo[3.n.1] ring systems and the total synthesis of the natural product (1R)-suberosanone.

Dissipation kinetics, safety evaluation, and preharvest interval assessment of trichlorfon application on rice.

Nowadays, there is an urgent need for the investigation of the field dissipation and assessment of the preharvest interval for trichlorfon residues on rice. To protect consumers from potential health risks, this study can provide references for the safe application of trichlorfon in the rice fields. Results of the field dissipation study showed that the dissipation dynamic equations of trichlorfon were based on the first-order reaction dynamic equations and that the dissipation rates vary among rice plant, brown rice, rice bran, soil, and water. The 2-year field trials conducted in Yangzhou and Xiaogan suggested the interval of each application for trichlorfon on rice to be at least 7 days when 80 % trichlorfon SP was sprayed with a dose ranges between 80 and 160 a.i g/667 m(2). Additionally, the preharvest interval of the last application should be at least 15 days to ensure the amounts of residues below the maximum residue limits of trichlorfon on brown rice (0.1 mg/kg).

[Synthesis and Identification of Artificial Antigen of Mangiferin].

OBJECTIVE: To establish an enzyme linked immunosorbent assay(ELISA) for mangiferin (MRn), artificial antigen of MRn was synthesized. METHODS: Oxidation method using sodium iodide was used to synthesize immunogenic antigen (MRn-BSA) and coating antigen(MRn-OVA) of MRn. The characterization of the synthesis was examined by UV spectrometry. BALB/c mice were immunized with the prepared MRn-BSA immunogenic antigen. The titer of the anti-serum was detected by ELISA, in the meanwhile the immunogenicity of MRn-BSA was confirmed by indirect competitive ELISA (icELISA). RESULTS: UV spectroscopy showed that MRn was successfully conjugated with OVA and BSA,so the new compound of MRn-BSA was synthesized, the coupling ratio was 6: 1. After immuned MRn-BSA, the mice could produce anti-MRn antibodies specifically, of which titer was up to 1: 4 000, and the general range was 1 - 100 µg/mL. CONCLUSION: Anti-MRn antibodies are discovered in the serum of mice, which indicates that artificial antigen of MRn is successfully synthesized,for the purpose of preparing monoclonal antibodies, as well as the establishment of appropriate immune methods.

Youngia erythrocarpa, a newly discovered cadmium hyperaccumulator plant.

The farmland weed Youngia erythrocarpa has been found to have the basic characteristics of a cadmium (Cd) hyperaccumulator. This study carried out preliminary and further Cd concentration gradient experiments and field experiment using Y. erythrocarpa to confirm this fact. The results showed that the biomass and resistance coefficient of Y. erythrocarpa decreased, but the root/shoot ratio and the Cd content in roots and shoots increased with the increase in soil Cd concentration. The Cd content in shoots of Y. erythrocarpa exceeded 100 mg/kg when the soil Cd concentration was 25 mg/kg in the two concentration gradient experiments, up to the maxima of 293.25 and 317.87 mg/kg at 100 mg/kg soil Cd. Both the bioconcentration factor of the shoots and the translocation factor exceeded 1 in all Cd treatments. In the field experiment, the total Cd extraction by shoots was 0.934-0.996 mg/m(2) at soil Cd levels of 2.04-2.89 mg/kg. Therefore, Y. erythrocarpa is a Cd hyperaccumulator that could be used to remediate Cd-contaminated farmland soil efficiently.

A stable N-heterocyclic carbene organocatalyst for hydrogen/deuterium exchange reactions between pseudoacids and deuterated chloroform.

It was observed that the stable and commercially available N-heterocyclic carbene (NHC) 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene, the so-called IDipp, catalyzes hydrogen/deuterium exchange reactions between pseudoacids and chloroform-d1, while the analogous saturated NHC 1,3-bis(2,4,6-trimethylphenyl)imidazolin-2-ylidene, the so-called SIMes, is inefficient for the same transformation. Experimental and computational DFT studies allowed these differences of reactivity to be attributed to the relative stability of the corresponding azolium­trichloromethyl anion ion pairs: in the former case, the complex evolves toward dissociation of the ions to produce an aromatic azolium cation and a basic trichloromethyl anion, while in the latter case, it evolves by ion recombination to give the product of formal carbene C­H insertion into the C­H bond of chloroform. These results provide a rationale for some early intuitions and observations of Wanzlick, Arduengo, and others on the reactivity of NHCs with chloroform as well as a simple organocatalytic method for the deuteration of pseudoacids (pKa,DMSO = 14­19) with chloroform-d1.