Photoredox-Catalyzed Synthesis of 3-Sulfonylated Pyrrolin-2-ones via a Regioselective Tandem Sulfonylation Cyclization of 1,5-Dienes.

A mild, visible-light-induced, regioselective cascade sulfonylation-cyclization of 1,5-dienes with sulfonyl chlorides through the intermolecular radical addition/cyclization of alkenes C(sp2)-H was developed. This procedure proceeds well and affords a mild and efficient route to a range of monosulfonylated pyrrolin-2-ones at room temperatures.

Electrochemical Site-Selective Alkylation of Azobenzenes with (Thio)Xanthenes.

Herein, we first report an electrochemical methodology for the site-selective alkylation of azobenzenes with (thio)xanthenes in the absence of any transition metal catalyst or external oxidant. A variety of groups are compatible with this electrochemical alkylation, which furnishes the products in moderate to good yields.

Transcriptomic Analysis of Cadmium Stressed Tamarix hispida Revealed Novel Transcripts and the Importance of Abscisic Acid Network.

Cadmium (Cd) pollution is widely detected in soil and has been recognized as a major environmental problem. Tamarix hispida is a woody halophyte, which can form natural forest on the desert and soil with 0.5 to 1% salt content, making it an ideal plant for the research on response to abiotic stresses. However, no systematic study has investigated the molecular mechanism of Cd tolerance in T. hispida. In the study, RNA-seq technique was applied to analyze the transcriptomic changes in T. hispida treated with 150 µmol L-1 CdCl2 for 24, 48, and 72 h compared with control. In total, 72,764 unigenes exhibited similar sequences in the Non-redundant nucleic acid database (NR database), while 36.3% of all these unigenes may be new transcripts. In addition, 6,778, 8,282, and 8,601 DEGs were detected at 24, 48, and 72 h, respectively. Functional annotation analysis indicated that many genes may be involved in Cd stress response, including ion bonding, signal transduction, stress sensing, hormone responses and ROS metabolism. A ThUGT gene from the abscisic acid (ABA) signaling pathway can enhance Cd resistance ability of T. hispida by regulating the production of ROS under Cd stress and inhibit absorption of Cd. The new transcriptome resources and data that we present in this study for T. hispida may facilitate investigation of molecular mechanisms governing Cd resistance.

Visualization analysis of lecithin in drugs based on electrochemiluminescent single gold microbeads.

Fast and high-throughput determination of drugs is a key trend in clinical medicine. Single particles have increasingly been adopted in a variety of photoanalytical and electroanalytical applications, and microscopic analysis has been a hot topic in recent years, especially for electrochemiluminescence (ECL). This paper describes a simple ECL method based on single gold microbeads to image lecithin. Lecithin reacts to produce hydrogen peroxide under the successive enzymatic reaction of phospholipase D and choline oxidase. ECL was generated by the electrochemical reaction between a luminol analog and hydrogen peroxide, and ECL signals were imaged by a camera. Despite the heterogeneity of single gold microbeads, their luminescence obeyed statistical regularity. The average luminescence of 30 gold microbeads is correlated with the lecithin concentration, and thus, a visualization method for analyzing lecithin was established. Calibration curves were constructed for ECL intensity and lecithin concentration, achieving detection limits of 0.05 mM lecithin. This ECL imaging platform based on single gold microbeads exhibits outstanding advantages, such as high throughput, versatility and low cost, and holds great potential in disease diagnostics, environmental monitoring and food safety.

Visualization analysis of lecithin in drugs based on electrochemiluminescent single gold microbeads / 药物分析学报

Fast and high-throughput determination of drugs is a key trend in clinical medicine.Single particles have increasingly been adopted in a variety of photoanalytical and electroanalytical applications,and microscopic analysis has been a hot topic in recent years,especially for electrochemiluminescence (ECL).This paper describes a simple ECL method based on single gold microbeads to image lecithin.Lecithin reacts to produce hydrogen peroxide under the successive enzymatic reaction of phospholipase D and choline oxidase.ECL was generated by the electrochemical reaction between a luminol analog and hydrogen peroxide,and ECL signals were imaged by a camera.Despite the heterogeneity of single gold microbeads,their luminescence obeyed statistical regularity.The average luminescence of 30 gold microbeads is correlated with the lecithin concentration,and thus,a visualization method for analyzing lecithin was established.Calibration curves were constructed for ECL intensity and lecithin concentra-tion,achieving detection limits of 0.05 mM lecithin.This ECL imaging platform based on single gold microbeads exhibits outstanding advantages,such as high throughput,versatility and low cost,and holds great potential in disease diagnostics,environmental monitoring and food safety.

Rh(III)-Catalyzed N-Nitroso Directed C-H Arylation for Facile Construction of Diverse N-Hetero Biaryl Compounds.

A Rh(III)-catalyzed C-H arylation reaction of N-nitrosoanilines has been developed in which arylboronic acids were used as arylation reagents. It provides an efficient strategy for the synthesis of N-nitroso-[1,1'-biphenyl]-2-amine, which is an important starting material for the synthesis of N-hetero biaryl compounds, such as 2-amine-1,1'-biphenyl, carbazole, phenanthridone. This protocol can be applied to various N-alkyl substituted N-nitrosoanilines and N-nitrosoanilines with substituents on the phenyl ring. Arylboronic acids with both electron-donating and electron-withdrawing groups are tolerated.

BF3·OEt2-mediated cyclization of ß,γ-unsaturated oximes and hydrazones with N-(arylthio/arylseleno)succinimides: an efficient approach to synthesize isoxazoles or dihydropyrazoles.

A highly efficient BF3·OEt2-mediated cyclization of ß,γ-unsaturated oximes and tosylhydrazones with N-(arylthio/arylseleno)succinimides has been established for the construction of N-heterocycles in a one-step manner. This metal-free cyclization provides direct access to isoxazoles and dihydropyrazoles in good to excellent yields at room temperature. The mechanistic experiments support the formation of a cationic species PhS+ which plays a critical role in this cyclization process.

Testicular Metastasis from Urothelial Carcinoma of the Renal Pelvis: A Rare Case and Review of the Literature.

This paper presents an extremely rare case of testicular metastasis arising from renal pelvis carcinoma. The testicle is a rare site of clinically detectable tumor metastasis, originating rarely from upper tract urothelial carcinoma (UTUC). There are only two cases concerning UTUC metastasis to the testis available in the literature. In this report, we presented a patient who developed serial testicle, lung, liver and retroperitoneal lymph node metastasis from primary urothelial carcinoma of the renal pelvis within one year after surgery and chemotherapy. In conclusion, for patients with a history of UTUC who present with testicular symptoms, clinicians should be highly alert for the possibility of malignant involvement at this site.

Metal-Organic Frameworks for Food Safety.

Food safety is a prevalent concern around the world. As such, detection, removal, and control of risks and hazardous substances present from harvest to consumption will always be necessary. Metal-organic frameworks (MOFs), a class of functional materials, possess unique physical and chemical properties, demonstrating promise in food safety applications. In this review, the synthesis and porosity of MOFs are first introduced by some representative examples that pertain to the field of food safety. Following that, the application of MOFs and MOF-based materials in food safety monitoring, food processing, covering preservation, sanitation, and packaging is overviewed. Future perspectives, as well as potential opportunities and challenges faced by MOFs in this field will also be discussed. This review aims to promote the development and progress of MOF chemistry and application research in the field of food safety, potentially leading to novel solutions.

Phosphoproteome Analysis Reveals the Molecular Mechanisms Underlying Deoxynivalenol-Induced Intestinal Toxicity in IPEC-J2 Cells.

Deoxynivalenol (DON) is a widespread trichothecene mycotoxin that commonly contaminates cereal crops and has various toxic effects in animals and humans. DON primarily targets the gastrointestinal tract, the first barrier against ingested food contaminants. In this study, an isobaric tag for relative and absolute quantitation (iTRAQ)-based phosphoproteomic approach was employed to elucidate the molecular mechanisms underlying DON-mediated intestinal toxicity in porcine epithelial cells (IPEC-J2) exposed to 20 µM DON for 60 min. There were 4153 unique phosphopeptides, representing 389 phosphorylation sites, detected in 1821 phosphoproteins. We found that 289 phosphopeptides corresponding to 255 phosphoproteins were differentially phosphorylated in response to DON. Comprehensive Gene Ontology (GO) analysis combined with Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment revealed that, in addition to previously well-characterized mitogen-activated protein kinase (MAPK) signaling, DON exposure altered phosphatidylinositol 3-kinase/Akt (PI3K/Akt) and Janus kinase/signal transducer, and activator of transcription (JAK/STAT) pathways. These pathways are involved in a wide range of biological processes, including apoptosis, the intestinal barrier, intestinal inflammation, and the intestinal absorption of glucose. DON-induced changes are likely to contribute to the intestinal dysfunction. Overall, identification of relevant signaling pathways yielded new insights into the molecular mechanisms underlying DON-induced intestinal toxicity, and might help in the development of improved mechanism-based risk assessments in animals and humans.

Development of a Efficient and Sensitive Dispersive Liquid-Liquid Microextraction Technique for Extraction and Preconcentration of 10 ß2-Agonists in Animal Urine.

Dispersive liquid-liquid microextraction (DLLME) coupled with ultra-performance liquid chromatography with tandem mass spectrometry (UPLC-MS/MS) was developed for the extraction and determination of 10 ß2-agonists in animal urine. Some experimental parameters, such as the type and volume of the extraction solvent, the concentration of the dispersant, the salt concentration, the pH value of the sample solution, the extraction time and the speed of centrifugation, were investigated and optimized. Under the optimized conditions, a good enrichment factors (4.8 to 32.3) were obtained for the extraction. The enrichment factor show that the concentration rate of DLLME is significantly higher than other pretreatment methods, and the detection sensitivity has been greatly improved. The calibration curves were linear, the correlation coefficient ranged from 0.9928 to 0.9999 for the concentration range of 0.05 to 50 ng mL(-1) and 0.1 to 50 ng mL(-1), and the relative standard deviations (RSDs, n = 15, intra and inter-day precision) at a concentration of 5 ng mL(-1) were in the range of 1.8 to 14.6%. The limits of detection (LODs) for the 10 ß2-agonists, based on a signal-to-noise ratio (S/N) of 3, were in the range of 0.01 to 0.03 ng mL(-1). The proposed method was used to identify ß2-agonists in three types of animal urine (swine, cattle, sheep), and the relative recoveries from each matrix were in the range of 89.2 to 106.8%, 90.0 to 109.8% and 89.2 to 107.2%, respectively.

Pd-Catalyzed C(sp(3))-H Carbonylation of Alkylamines: A Powerful Route to γ-Lactams and γ-Amino Acids.

A novel Pd-catalyzed direct C(sp(3))-H carbonylation of alkylamines for the synthesis of γ-lactams and γ-amino acids has been developed, in which TEMPO was used as the crucial sole oxidant. The synthetic prospect was demonstrated by the concise total synthesis of rac-Pregbalin.

A lower pH value benefits regeneration of Trichosanthes kirilowii by somatic embryogenesis, involving rhizoid tubers (RTBs), a novel structure.

A new approach was established for the regeneration of Trichosanthes kirilowii from root, stem, and leaf explants by somatic embryogenesis (SE), involving a previously unreported SE structure, rhizoid tubers (RTBs). During SE, special rhizoids were first induced from root, stem, and leaf explants with average rhizoid numbers of 62.33, 40.17, and 11.53 per explant, respectively, on Murashige and Skoog (MS) medium (pH 4.0) supplemented with 1.0 mg/L 1-naphthaleneacetic acid (NAA) under dark conditions. Further, one RTB was formed from each of the rhizoids on MS medium (pH 4.0) supplemented with 20 mg/L thidiazuron (TDZ) under light conditions. In the suitable range (pH 4.0-9.0), a lower pH value increased the induction of rhizoids and RTBs. Approximately 37.77, 33.47, and 31.07% of in vivo RTBs from root, stem, and leaf explants, respectively, spontaneously developed into multiple plantlets on the same MS medium (supplemented with 20 mg/L TDZ) for induction of RTBs, whereas >95.00% of in vitro RTBs from each kind of explant developed into multiple plantlets on MS medium supplemented with 5.0 mg/L 6-benzylaminopurine (BAP). Morphological and histological analyses revealed that RTB is a novel type of SE structure that develops from the cortex cells of rhizoids.

[Study on the chemical constituents of Herpetospermum caudigerum].

OBJECTIVE: To study the chemical constituents of Herpetospermum caudigerum. METHODS: The chemical constituents were isolated by silica gel, Sephedex LH-20 and MCI methods. Their structures were elucidated by physical-chemical properties and spectroscopic methods such as UV, IR, ESI-MS, H-NMR and 13 C-NMR. RESULTS: Seven compounds were isolated and identified as Herpetolide A (1), Herpetolide B (2), Dehydrodiconiferyl alcohol (3), Herpetol (4), Arbutin, 1-acetate (5), Dodecanoic acid (6) and 10-Eicosenoic acid (7). CONCLUSION: compounds 5-7 are isolated from this plant for the first time.

[Study on the method of using ICP-MS to determine microelements in the animal feed].

The method for the determination of microelements such as Cu, Zn, Fe, Mn, Cr, Cd, Pb, As and Se in the animal feed by inductively coupled plasma-mass spectrometry was developed. The operation parameters, spectrum interference, matrix effect and memorial effect were studied in detail. Under optimal condition, the detection limits of these nine elements were from 2.03 x 10(-3) to 3.17 microg x L(-1), and the linear range was over three orders with a correlation coefficient above 0.999. This method was applied directly to determine microelements in real samples involving the standard wheat powder, formular feed and pre-mix feed. The determination results of microelements in the standard wheat powder accorded with reference results. The recovery of microelements in the formular feed was from 86% to 115%, and the relative standard deviations < or = 8.2% (n = 6). The results of elements content in the pre-mix feed were identical with those determined by national standard method. This method is simple, sensitive, accurate and can perform simultaneous multi-elements determination compared with conventional method of animal feed determination. The results were satisfactory.

[A study on the preventive effect of Lycium barbarum polysaccharide on the development of alcoholic fatty liver in rats and its possible mechanisms].

OBJECTIVE: To study the preventive effects of Lycium barbarum polysaccharide (LBP) on the development of alcoholic fatty liver (AFL) in rats and its possible mechanisms. METHODS: One hundred twenty-five Wistar rats were randomly divided into 4 groups: a blank control group, with distilled water intragastric infusion (GI); an alcohol group, with alcohol GI; a 5% LBP plus alcohol GI group; and a 10% LBP plus alcohol GI group. Liver pathologic changes were studied together with the activity of serum ALT, AST, GGT, the activity of liver SOD, GSH-PX and the content of liver MDA, GSH, H2O2; CYP2E1 gene and protein expressions were also detected. RESULTS: At the end of ten weeks, the activity of serum AST [(132.3+/-25.7) U/L, (127.5+/-29.1)U/L] and GGT [(1.9+/-0.5)U/L, (1.8+/-0.7)U/L] of the two LBP groups were all significantly lower than those of the alcohol group [serum AST (245.7+/-32.1) and GGT (4.4+/-0.6)]. At the end of ten weeks, the content of liver MDA [(5.1+/-0.3) nmol/mg, (5.1+/-0.4) nmol/mg] and H2O2 [(135.4+/-23.5) mmol/g, (132.6+/-31.8) mmol/g] of the two LBP groups were significantly lower than those of the alcohol group [MDA (14.5+/-3.2) nmol/mgprot) and H2O2 (328.5+/-45.6)]. The activity of SOD [(206.7+/-13.2)U/L, (203.2+/-18.8)U/L], GSH-PX [(13.5+/-1.4)U/mg/min, (13.6+/-1.5)U/mg/min] and the content of GSH [(65.1+/-11.0)mg/g, (66.6+/-11.1) mg/g] of the two LBP groups were all significantly higher than those of the alcohol group [SOD (116.5+/-13.6)U/mg/min, GSH-PX (7.2+/-1.6)U/mg/min and the content of GSH (30.5+/-10.7)mg/g] (P less than 0.01). At the end of five weeks, levels of CYP2E1 gene and protein expression of the two LBP groups were 0.39+/-0.04, 0.40+/-0.06 and 3.49+/-0.36, 3.29+/-0.30 respectively. At the end of ten weeks, levels of CYP2E1 gene and protein expression of the two LBP groups were 0.41+/-0.05, 0.42+/-0.08 and 3.58+/-0.30, 3.36+/-0.37 respectively. They were all significantly lower than those of the alcohol group [the gene expression (5 week: 0.74+/-0.05, 10 week: 1.02+/-0.08) and the protein expression (5 week: 5.63+/-0.44, 10 week: 7.90+/-0.26)]. There were no typical alcoholic fatty liver pathologic changes observed in the two LBP groups. CONCLUSION: LBP can effectively prevent AFL. This may be due to its effects in inhibiting the hepatocyte CYP2E1 expression and prevention of lipid peroxidation.

[Study on determination of rare earth La and Ce in feed by using ICP-MS].

An advanced method for the determination of rare earth La and Ce in animal feed by using of inductively coupled plasma mass spectrometry was studied. The operation parameters for ICP-MS was optimized, the effect of pre-mix feed matrix and formular feed matrix for La and Ce was studied by the conventional method and stepwise dilution method, and the suppression of signal intensity of La and Ce by nitric acid was examined. Under the optimum condition, the limit of determination for La and Ce were 2.62 x 10(-2) microg x kg(-1) and 6.47 x 10(-3) microg x kg(-1), respectively, the linear coefficient was 1.000 0, the dynamical linear range was of 3 order of magnitudes, and the internal standards were In(115) and Tb(159). The developed method was applied to the determination of rare earth La and Ce in pre-mix feed and formular feed, with the recovery > or = 77.8% and the relative standard deviation(RSD) < or = 8.5%, and the testing results were satisfactory.

Application of functional group modified substrate in room temperature phosphorescence, II--heavy atom-chelated filter paper for selective determination of alpha-naphthalene acetic acid.

Heavy atom-chelated filter paper was synthesized and used as the substrate for room-temperature phosphorescence (RTP). The synthesis conditions for chelated paper were studied. The Pb-chelated filter paper could selectively induce the RTP of alpha-naphthalene acetic acid (alpha-NAA). The excitation and emission wavelengths of RTP of alpha-NAA were 300 nm and 521 nm, respectively. The concentration of alpha-NAA was linear with the RTP intensity in the range 2 x 10(-6)-6 x 10(-4) mol/L (correlation coefficient, 0.9999). The concentration detection limit was 1.35 x 10(-7) mol/L and the absolute detection limit was 0.25 ng/spot. The RSD (n = 10) was 1.7%. The method was applied to the analysis of water and vegetable samples with satisfactory results. Because the heavy atom was directly chelated onto the filter paper, the heavy-atom effect on the RTP of NAA was further increased and the analysis procedure was simple, fast and economical.