Detoxifying bacterial genes for deoxynivalenol epimerization confer durable resistance to Fusarium head blight in wheat.

Fusarium head blight (FHB) and the presence of mycotoxin deoxynivalenol (DON) pose serious threats to wheat production and food safety worldwide. DON, as a virulence factor, is crucial for the spread of FHB pathogens on plants. However, germplasm resources that are naturally resistant to DON and DON-producing FHB pathogens are inadequate in plants. Here, detoxifying bacteria genes responsible for DON epimerization were used to enhance the resistance of wheat to mycotoxin DON and FHB pathogens. We characterized the complete pathway and molecular basis leading to the thorough detoxification of DON via epimerization through two sequential reactions in the detoxifying bacterium Devosia sp. D6-9. Epimerization efficiently eliminates the phytotoxicity of DON and neutralizes the effects of DON as a virulence factor. Notably, co-expressing of the genes encoding quinoprotein dehydrogenase (QDDH) for DON oxidation in the first reaction step, and aldo-keto reductase AKR13B2 for 3-keto-DON reduction in the second reaction step significantly reduced the accumulation of DON as virulence factor in wheat after the infection of pathogenic Fusarium, and accordingly conferred increased disease resistance to FHB by restricting the spread of pathogenic Fusarium in the transgenic plants. Stable and improved resistance was observed in greenhouse and field conditions over multiple generations. This successful approach presents a promising avenue for enhancing FHB resistance in crops and reducing mycotoxin contents in grains through detoxification of the virulence factor DON by exogenous resistance genes from microbes.

Efficient Water Reforming of Biomass to H2 via Well-Organized Redox-Neutral Cleavage of C-C, O-H and C-H Bonds.

Hydrogen (H2) is a clean and environmentally friendly energy carrier. The depletion of fossil fuels makes renewable H2 production highly desirable. Water reforming of renewable biomass to hydrogen, with a relay of natural photosynthesis to biomass, would be an indirect pathway to realize the ideal but extremely challenging photocatalytic overall water splitting to hydrogen, with favorable thermodynamics. Since the seminal work of water reforming of biomass in 1980, great endeavors have been made. Nevertheless, hitherto, the entire kinetic pathway has been elusive, which seriously limits the reforming processes. Using a designed well-organized redox-neutral cleavage of C-C, O-H and C-H bonds enabled by photoelectrocatalysis, here, we show the efficient water reforming of biomass to hydrogen at room temperature, with a yield up to 93%. The clear insights into the kinetic pathway with oxidation of carbon radicals to carbon cations as the indicated rate-determining step, would cast brightness for efficient and sustainable hydrogen production to accelerate the hydrogen economy.

Tailoring Amorphous PdCu Nanostructures for Efficient C-C Cleavage in Ethanol Electrooxidation.

The large-scale application of direct ethanol fuel cells has long been obstructed by the sluggish ethanol oxidation reaction at the anode. Current wisdom for designing and fabricating EOR electrocatalysts has been focused on crystalline materials, which result in only limited improvement in catalytic efficiency. Here, we report the amorphous PdCu (a-PdCu) nanomaterials as superior EOR electrocatalysts. The amorphization of PdCu catalysts can significantly facilitate the C-C bond cleavage, which thereby affords a C1 path faradic efficiency as high as 69.6%. Further tailoring the size and shape of a-PdCu nanocatalysts through the delicate kinetic control can result in a maximized mass activity up to 15.25 A/mgPd, outperforming most reported catalysts. Notably, accelerated durability tests indicate that both the isotropic structure and one-dimensional shape can dramatically enhance the catalytic durability of the catalysts. This work provides valuable guidance for the rational design and fabrication of amorphous noble metal-based electrocatalysts for fuel cells.

Selective Sensing of Fe(3+) and Al(3+) Ions and Detection of 2,4,6-Trinitrophenol by a Water-Stable Terbium-Based Metal-Organic Framework.

A water-stable luminescent terbium-based metal-organic framework (MOF), {[Tb(L1 )1.5 (H2 O)]⋅3 H2 O}n (Tb-MOF), with rod-shaped secondary building units (SBUs) and honeycomb-type tubular channels has been synthesized and structurally characterized by single-crystal X-ray diffraction. The high green emission intensity and the microporous nature of the Tb-MOF indicate that it can potentially be used as a luminescent sensor. In this work, we show that Tb-MOF can selectively sense Fe(3+) and Al(3+) ions from mixed metal ions in water through different detection mechanisms. In addition, it also exhibits high sensitivity for 2,4,6-trinitrophenol (TNP) in the presence of other nitro aromatic compounds in aqueous solution by luminescence quenching experiments.

[Zirconium-based metal-organic framework composites for solid phase extraction of brevetoxin-A from seawater].

Red tides are a type of natural marine disaster caused by harmful algae characterized by a high toxicity, wide distribution, and long duration. Since the concentration of algal toxins in seawater increases with the occurrence of red tides, algal toxins detected in seawater could be used to predict the occurrence and evolution of red tides. Brevetoxin-A (BTX-A) is a secondary metabolite produced by the harmful algae Karenia brevis, whose detection in seawater could form the basis of an accurate warning system for incoming red tides. However, due to the inherent complexity of the seawater matrix and the extremely low levels of BTX-A in seawater, the use of instruments for its direct detection is difficult. Therefore, there is an urgent need to develop a sample pretreatment method for the efficient enrichment of BTX-A in seawater. In this study, a metal-organic backbone material (UiO-66) and its composite with silica microspheres (SiO2@UiO-66) were successfully synthesized using the solvothermal method. The prepared SiO2@UiO-66 exhibited good hydrophilicity, water stability, and large specific surface area. Furthermore, it also exhibited hydrogen bonding and electrostatic interactions with BTX-A, had a strong affinity for BTX-A, and was able to efficiently adsorb BTX-A in complex matrices. Therefore, SiO2@UiO-66 showed potential as a novel packing material for the extraction of BTX-A from solid phase extraction columns. Combined with high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), a highly sensitive detection method for the determination of BTX-A in marine water was established. The established analytical method had a low detection limit (3.0 pg/mL), a wide linear range (10.0 -200.0 pg/mL), and a good linear relationship (R=0.9992). Combined with the Fujian Province Red Tide Monitoring and Early Warning Information 2021 issued by the Fujian Provincial Oceanic and Fisheries Bureau, the analytical method established herein was successfully applied to analyze and monitor the content of BTX-A in actual seawater samples. This highlights the proposed system's potential for use as an early warning factor in the monitoring of red tides, representing a simple and fast pretreatment methodology for the detection of BTX-A in seawater.

[Research progress of novel functional materials in extraction of algal toxins].

Algal toxins are secondary metabolites produced by harmful algae; these metabolites are characterized with strong toxicity, diverse structure and bioaccumulation. Aquatic organisms that feed on harmful algae can accumulate algal toxins in their bodies, and the consumption of these organisms by humans can cause symptoms of paralysis, diarrhea, and even death. The onset of poisoning can occur within as little as 30 min; in many cases, no suitable antidote for algal toxins is available. Thus, algal toxins present significant threats to human health, the aquaculture industry, and aquatic ecosystems. Because the potential risks of algal toxins are a critical issue, these toxins have become a research hotspot. The water environment and various types of aquatic products should be monitored and analyzed to ensure their safety. However, because of possible matrix effects and the low content of algal toxins in actual samples, an efficient pretreatment method is necessary prior to instrumental analyses. Efficient sample pretreatment techniques can not only reduce or eliminate interferences from the sample matrix during analysis but also enrich the target analytes to meet the detection limit of the analytical instrument, thereby ensuring the sensitivity and accuracy of the detection method. In recent years, sample pretreatment techniques such as solid-phase extraction (SPE), solid-phase microextraction (SPME), magnetic SPE (MSPE), dispersive SPE (DSPE), and pipette tip-based SPE (PT-SPE) have gained wide attention in the field of algal-toxin separation and analysis. The performance of these pretreatment techniques largely depends on the characteristics of the extraction materials. Given the diverse physicochemical properties of algal toxins, including their different molecular sizes, hydrophobicity/hydrophilicity, and charges, the design and preparation of materials suitable for algal-toxin extraction is an essential undertaking. The optimal extraction material should be capable of reversible algal-toxin adsorption and preferably possess a porous structure with a large surface area to allow for high recovery rates and good interfacial contact with the toxins. Additionally, the extraction material should exhibit good chemical stability in the sample solution and elution solvent within the working pH range; otherwise, it may dissolve or lose its functional groups. Many research efforts have sought to develop novel adsorbent materials with these properties in the separation and analysis of algal toxins, focusing on carbon-based materials, metal organic frameworks (MOFs), covalent organic frameworks (COFs), molecularly imprinted polymers (MIPs), and their functionalized counterparts. Carbon-based materials, MOFs, and COFs have advantages such as large surface areas and abundant adsorption sites. These extraction materials are widely used in the separation and analysis of target substances in complex environmental, biological, and food samples owing to their excellent performance and unique microstructure. They are also the main adsorbents used for the extraction of algal toxins. These extraction materials play an essential role in the extraction of algal toxins, but they also present a number of limitations: (1) Carbon-based materials, MOFs, and COFs have relatively poor selective-adsorption ability towards target substances; (2) Most MOFs are unstable in aqueous solutions and challenging to apply during extraction from water-based sample solutions; (3) COFs mainly consist of lightweight elements, rendering them difficult to completely separate from sample solutions using centrifugal force, which limits their application range; (4) Although MIPs have good selectivity, issues such as template-molecule loss, slow mass-transfer rates, and low adsorption capacity must be addressed. Therefore, the design and preparation of novel functionalized extraction materials specifically tailored for algal toxins and studies on new composite extraction materials are highly desirable. This article collects representative literature from domestic and international research on algal-toxin analysis over the past decade, summarizes the relevant findings, categorizes the applications of novel functional materials in algal-toxin-extraction processes, and provides an outlook on their future development prospects.

Clinical Reasoning: A 26-Year-Old Woman With Recurrent Pain, Weakness, and Atrophy in Bilateral Upper Limbs During Pregnancy and Puerperium.

We present the case of a 26-year-old woman with recurrent episodes of severe pain, weakness, and atrophy in her bilateral upper extremities during pregnancy and puerperium. She reported 2 similar episodes at ages 5 and 10 years, after which she fully recovered. On examination, we observed significant atrophy in her bilateral upper extremity muscles with decreased strength. Needle electromyography (EMG) revealed neurogenic damage in her bilateral upper limbs. The patient's clinical manifestations and auxiliary examination suggested a brachial plexopathy. Metabolic and immune factors that may occur during pregnancy and puerperium were evaluated. We also screened for paraneoplastic, neoplastic, and genetic factors. Finally, a hereditary form of disease was considered. This case emphasizes the importance of early diagnosis and avoidance of triggers.

A solid phase extraction column based on SiO2@ZIF-8 for efficient analysis of domoic acid toxins in the seawater environment: experiments and DFT calculations on adsorption behaviour.

Algal toxins are important metabolites of toxic harmful algal blooms (HABs), and their qualitative and qualitative detection can serve as early warning indicators for toxic HABs, complementing traditional HAB monitoring and improving the accuracy of early warning. Therefore, this work took the detection of domoic acid (DA) as an example and prepared zeolitic imidazolate framework-8 (ZIF-8) with high enrichment performance and high water stability and its core-shell composite material SiO2@ZIF-8 as an adsorbent filler. Density functional theory (DFT) calculations and interference experiments verified that Zn2+ on SiO2@ZIF-8 played a crucial role in enriching DA on SiO2@ZIF-8. By using it as a solid-phase extraction (SPE) filler, it showed excellent performance compared with other SPE columns (C18/HLB/SAX/ZIF-8). Therefore, the SiO2@ZIF-8 column was coupled to high-performance liquid chromatography-mass spectrometry (SPE-HPLC-MS/MS) to establish a highly sensitive detection method for algal toxins in seawater, which had a wide linear range (12.0-5000.0 ng L-1), good reproducibility (RSD) and low limit of detection (4.0 ng L-1), and realized the monitoring of trace DA in the Pingtan sea area of Fujian Province from 2021 to 2022. By comparing other HAB early warning indicators such as salinity and pH and combining them with the information released by the Fujian Provincial Ocean and Fisheries Bureau, the content of DA in seawater measured by the established SPE-HPLC-MS/MS method can provide reference information for HAB monitoring and early warning.

Synergistically mediated enhancement of cathodic and anodic electrochemiluminescence of graphene quantum dots through chemical and electrochemical reactions of coreactants.

We for the first time propose a new concept where a greater enhancement in dual potential electrochemiluminescence (ECL) of a single graphene quantum dot (GQD) emitter can be achieved through the coupling between chemical and electrochemical reactions of two different coreactants of K2S2O8 and Na2SO3.

Photoluminescence modulation of an atomically precise silver(i)-thiolate cluster via site-specific surface engineering.

A series of pyridyl ligand functionalized silver-thiolate nanoclusters with an identical cuboctahedron Ag12 core were prepared through site-specific surface engineering and fully characterized. Their wide-range photoluminescence modulation was systematically studied.

[Study of expression of CD138 and heparinase in hepatocellular carcinoma by tissue microarray].

OBJECTIVE: To study the expression of CD138 and heparinase in hepatocellular carcinoma (HCC) and its relationship with tumor development, progression, metastasis and recurrence. METHODS: Tissue microarray and immunohistochemical study (EnVision method) for CD138 and heparinase was performed on tissue microarray which consisted of 197 cases of HCC, including adjacent non-neoplastic liver tissues, and 66 cases of HCC metastases. RESULTS: The rates of CD138 expression in HCC and adjacent non-neoplastic liver tissues were 48.7% (96/197) and 65.0% (128/197, P < 0.05) respectively. In early-stage and late-stage tumors, the expression rates were 61.7% (29/47) and 44.7% (67/150, P < 0.05) respectively. The rate in patients with metastasis was 33.3% (22/66), as compared with 53.6% (45/84, P < 0.05) in patients without metastasis. In patients with tumor recurrence occurring within or after 1 post-operative year, the expression rates were 23.3% (7/30) and 61.1% (11/18, P < 0.05) respectively. On the other hand, the rates of expression of heparinase in HCC and adjacent non-neoplastic liver tissues were 35.5% (70/197) and 12.7% (25/197, P < 0.05) respectively. In early-stage and late-stage tumors, the expression rates were 29.8% (14/47) and 37.3% (56/150, P > 0.05) respectively. The rate in patients with metastasis was 48.5% (32/66), as compared with 28.6% (24/84, P < 0.05) in patients without metastasis. In patients with tumor recurrence occurring within or after 1 post-operative year, the expression rates were 50.0% (15/30) and 44.4% (8/18, P > 0.05) respectively. In the 66 cases of metastatic HCC studied, the expression rate of CD138 was lower in the heparinase-positive subgroup (P < 0.05). CONCLUSIONS: Loss of CD138 expression is related to HCC development, progression, metastasis and recurrence. Overexpression of heparinase, when coupled with loss of CD138 expression, may take part in tumor metastasis of HCC.

[Prokaryotic expression vector construction, expression and polyclonal antibody preparation of the fusion protein of glutathione S-transferase and peroxisome proliferator-activated receptor-gamma coactivator-1].

OBJECTIVE: To express the fusion protein of glutathione S-transferase (GST) and peroxisome proliferator-activated receptor-gamma coactivator-1 (PPARgammaC1) in E. coli. and prepare the polyclonal antibody against PPARgammaC1. METHODS: The coding sequence of PPARgammaC1 gene was amplified by reverse transcriptase-PCR (RT-PCR) from the total RNA of Hep G2 cells and inserted into pGEX-4T-1 vector. The recombinant vector was identified by restriction endonuclease digestion analysis and the fusion protein GST-PPARgammaC1 was expressed in E. coli. via IPTG induction. The expressed fusion protein was purified by glutathione-agarose affinity chromatography and used to immunize the egg-laying hens for preparing the polyclonal antibody against GST-PPARgammaC1. RESULTS: Restriction endonuclease digestion analysis demonstrated that the PPARgammaC1 gene had been correctly inserted into pGEX-4T-1 vector, and the expressed fusion protein had a relative molecular mass of approximately 39,000 as shown by SDS-PAGE. The polyclonal antibody obtained from the egg yolk immunoglobulins was found to specifically bind to purified PPARgammaC1 in Western blot analysis. CONCLUSION: The successfully prepared polyclonal antibody against PPARgammaC1 peptide provides a useful reagent for PPARgammaC1 detection.

[Expression of NY-ESO-1 and LAGE-1 cancer-testis antigens in hepatocellular carcinoma].

OBJECTIVE: To study the role of NY-ESO-1 and LAGE-1 cancer-testis antigens as targets for immunotherapy and the relationship between corresponding gene expression and biologic behavior of hepatocellular carcinoma (HCC). METHODS: The expression of NY-ESO-1 and LAGE-1 was studied in frozen tumor tissues from 30 cases of HCC by reverse transcriptase-polymerase chain reaction and immunohistochemistry. NY-ESO-1 expression and its distribution were further studied by immunohistochemistry in a tissue array contained 191 cases of HCC. RESULTS: NY-ESO-1 and LAGE-1 mRNAs were expressed in 33.3% (10/30) and 16.7% (5/30) of HCC respectively. Either NY-ESO-1 or LAGE-1 was expressed in 36.7% (11/30) cases. NY-ESO-1 was expressed mainly in the cytoplasm of tumor cells. It was positive in 13.8% (24/174) cases of HCC. There was an increased expression of NY-ESO-1 from 6.8%, 3/44 in small HCC, 16.2%, 21/130 in advanced HCC and 23.1%, 12/52 in metastatic HCC. The expression in the non-metastatic group was 9.8% (12/122). The differences between the metastatic group and non-metastatic group (< 0.05) and between normal liver tissue and HCC (< 0.01) were statistically significant. There was no relationship between NY-ESO-1 expression and tumor size. NY-ESO-1 and LAGE-1 were not detected in adjacent normal liver tissue. CONCLUSIONS: NY-ESO-1 and LAGE-1 are expressed in a high percentage of HCC, especially in cases with metastasis. It is thus possible that NY-ESO-1/LAGE-1 can serve as targets for antigen-specific immunotherapy in HCC and NY-ESO-1 peptide vaccination may be of use for patients with advanced HCC.

Amyloid precursor protein at node of Ranvier modulates nodal formation.

Amyloid precursor protein (APP), commonly associated with Alzheimer disease, is upregulated and distributes evenly along the injured axons, and therefore, also known as a marker of demyelinating axonal injury and axonal degeneration. However, the physiological distribution and function of APP along myelinated axons was unknown. We report that APP aggregates at nodes of Ranvier (NOR) in the myelinated central nervous system (CNS) axons but not in the peripheral nervous system (PNS). At CNS NORs, APP expression co-localizes with tenascin-R and is flanked by juxtaparanodal potassium channel expression demonstrating that APP localized to NOR. In APP-knockout (KO) mice, nodal length is significantly increased, while sodium channels are still clustered at NORs. Moreover, APP KO and APP-overexpressing transgenic (APP TG) mice exhibited a decreased and an increased thickness of myelin in spinal cords, respectively, although the changes are limited in comparison to their littermate WT mice. The thickness of myelin in APP KO sciatic nerve also increased in comparison to that in WT mice. Our observations indicate that APP acts as a novel component at CNS NORs, modulating nodal formation and has minor effects in promoting myelination.

[Correlation of NY-ESO-1 gene and protein expression to metastasis and clinicopathologic features of hepatocellular carcinoma].

BACKGROUND & OBJECTIVE: NY-ESO-1 belongs to cancer-testis antigen family. It can inspire both cellular and humoral immune responses in tumor patients, and is regarded as the strongest tumor antigen. This study was to investigate the expression of NY-ESO-1 gene and its correlation with clinicopathologic features of hepatocellular carcinoma (HCC). METHODS: NY-ESO-1 mRNA expression was detected by reverse transcription-polymerase chain reaction (RT-PCR) in 62 specimens of HCC and adjacent liver tissue. NY-ESO-1 protein expression and its distribution were detected by immunohistochemistry (IHC) in a tissue microarray contained 132 eligible cases of HCC. RESULTS: Positive rate of NY-ESO-1 mRNA was 27.4% in HCC; it was higher in HCC with tumor embolus of portal vein than in HCC without tumor embolism (40.0% vs. 18.9%). Positive rate of NY-ESO-1 protein was 18.9% in HCC tissue microarray; it was significantly higher in HCC with metastasis than in HCC without metastasis (29.6% vs. 11.5%, P < 0.05). NY-ESO-1 protein mainly located in cytoplasm of HCC cells. Positive rates of NY-ESO-1 mRNA and protein were 28.3% and 19.1% respectively in HBsAg positive HCC, and were 29.5% and 20.7% respectively in HCC with alpha fetoprotein (AFP) of > 20 ng/ml. Both NY-ESO-1 mRNA and protein were not detected in adjacent normal liver tissue. CONCLUSIONS: NY-ESO-1 gene specifically expresses in HCC, and may correlates with progress and metastasis of HCC. It may be a candidate target for antigen-specific immunotherapy for HCC with metastatic lesion. NY-ESO-1 expression has no correlation with HBsAg/AFP status of HCC.

[Expressions of inducible nitric oxide synthase and vascular endothelial growth factor and their relationship with microvessel density in hepatocellular carcinoma].

BACKGROUND & OBJECTIVE: Inducible nitric oxide synthase (iNOS), and vascular endothelial growth factor (VEGF) are recognized as key factors required for angiogenesis of tumors. They can influence pathologic development and prognosis of tumors. This study was to investigate the correlation of expressions of iNOS and VEGF to angiogenesis of hepatocellular carcinoma (HCC). METHODS: Tissue microarray of 147 specimens of HCC was prepared, VEGF and microvessel density (MVD) were detected using immunohistochemistry, iNOS mRNA was detected by in situ hybridization. RESULTS: Positive rates of iNOS, and VEGF in HCC tissues were higher than those in adjacent noncancerous tissues (86.39% vs. 33.33%, 78.91% vs. 40.82%). Expression levels of iNOS, and VEGF in HCC tissues were significantly higher than those in adjacent noncancerous tissues (P<0.01). MVD in HCC tissues was significantly higher than that in adjacent noncancerous tissues (56.5+/-12.8 vs. 8.4+/-3.6, P<0.01). Expression of iNOS was related with tumor size, and surface antigen of hepatitis B (HBsAg) (P<0.05), but didn't relate with metastasis, and differentiation of the cancer (P>0.05). Expression of VEGF, and MVD were correlated to tumor size, and metastasis (P<0.05), not to HbsAg, and tumor differentiation (P>0.05). In cancer tissues, MVD was positively correlated with expressions of VEGF and iNOS (P<0.01), expression of VEGF was positively correlated with that of iNOS (P<0.01). CONCLUSION: iNOS and VEGF may play important roles in angiogenesis of HCC. Expression levels of iNOS and VEGF, and MVD in HCC tissues were higher than those in adjacent noncancerous tissues.

[Study on the occurrence of cesarean section (CS) and factors related to CS in China].

OBJECTIVE: To find out the occurrence of cesarean section (CS) and to probe the factors associated with CS. METHODS: Women with CS as "case group" and women without CS as "control group" were chosen in a case-control study. RESULTS: Among 14 071 childbirth women, 6 421 had CS (case group) with the occurrence rate of 45.6% and 7 650 (54.4%) had normal delivery (control group). In comparison with the control group, the CS group had following several higher rates [with significant differences between case group and control group (P < 0.01)]: well-educated (78.9% vs 69.5%), white collar jobs (38.0% vs 32.3%), urban residents (79.1% vs 70.6%), high monthly income (>/= 500 Yuan) (81.0% vs 70.6%), of older age (>/= 25 years) (73.3% vs 63.0%), heavier baby weight (> 4 000 gram) (8.3% vs 2.9%), male babies (53.9% vs 51.4%), BMI of mother (> 24) (8.8% vs 4.8%), cephalopelvic disproportion (21.1% vs 0.9%), intrauterine asphysia (20.3% vs 6.7%), abnormality of force of labor (4.2% vs 2.7%), prolonged labor (2.9% vs 1.0%) and placenta previa (1.4% vs 0.4%). Our study also indicated that the higher the educational level was, the higher the rate of CS appeared; and the older the pregnant women was, the higher the rate of CS was. In CS group, over 70% primipara were over 24 years, and over 20% primipara had cephalopelvic disproportion and over 20% had intrauterine asphysia in CS group. CONCLUSIONS: At present, the occurrence rate of cesarean section was rather high (45.6%) in China. The high rate of CS was more likely to associate not only with abnormal physiological/medical factors (eg. cephalopelvic disproportion, intrauterine asphysia, abnormality of force of labor, and prolonged labour, etc.), but also with some demographic factors as education, occupation, income and age, etc. It is necessary to take measures to reduce the unnecessary CS in China.