Elongin B promotes breast cancer progression by ubiquitinating tumor suppressor p14/ARF.

Elongin B (ELOB), a pivotal element in the ELOB/c-Cullin2/5-SOCS-box E3 ubiquitin-protein ligase complex, plays a significant role in catalyzing the ubiquitination and subsequent degradation of a broad spectrum of target proteins. Notably, it is documented to facilitate these processes. However, the regulatory role of ELOB in breast cancer remains ambiguous. In this study, through bio-informatic analysis of The Cancer Genome Atlas and Fudan University Shanghai Cancer Center database, we demonstrated that ELOB was over-expressed in breast cancer tissues and was related to unfavorable prognosis. Additionally, pathway enrichment analysis illustrated that high expression of ELOB was associated with multiple cancer promoting pathways, like cell cycle, DNA replication, proteasome and PI3K - Akt signaling pathway, indicating ELOB as a potential anticancer target. Then, we confirmed that both in vivo and in vitro, the proliferation of breast cancer cells could be significantly suppressed by the down-regulation of ELOB. Mechanically, immunoprecipitation and in vivo ubiquitination assays prompted that, as the core element of Cullin2-RBX1-ELOB E3 ligase (CRL2) complex, ELOB regulated the ubiquitination and the subsequent degradation of oncoprotein p14/ARF. Moreover, the anticancer efficacy of erasing ELOB could be rescued by simultaneous knockdown of p14/ARF. Finally, through analyzing breast cancer tissue microarrays and western blot of patient samples, we demonstrated that the expression of ELOB in tumor tissues was elevated in compared to adjacent normal tissues. In conclusion, ELOB is identified to be a promising innovative target for the drug development of breast cancer by promoting the ubiquitination and degradation of oncoprotein p14/ARF.

[Relationship of triglyceride-glucose index and its derivatives with blood pressure abnormalities in adolescents: an analysis based on a restricted cubic spline model]. / åŸºäºŽé™åˆ¶æ€§ç«‹æ–¹æ ·æ¡æ¨¡åž‹åˆ†æžé’å°‘å¹´ä¸‰é °ç”˜æ²¹-è‘¡è„ç³–æŒ‡æ•°åŠå ¶è¡ç”ŸæŒ‡æ•°ä¸Žè¡€åŽ‹å¼‚å¸¸çš„å ³ç³».

OBJECTIVES: To explore the relationship of triglyceride-glucose index (TyG), triglyceride-glucose-body mass index (TyG-BMI), and triglyceride-glucose-waist circumference index (TyG-WC) with blood pressure abnormalities in adolescents, providing theoretical basis for the prevention and control of hypertension in adolescents. METHODS: A stratified cluster sampling method was used to select 1 572 adolescents aged 12 to 18 years in Yinchuan City for questionnaire surveys, physical measurements, and laboratory tests. Logistic regression analysis and restricted cubic spline analysis were employed to examine the relationship of TyG, TyG-BMI, and TyG-WC with blood pressure abnormalities in adolescents. RESULTS: Multivariable logistic regression analysis revealed that after adjusting for confounding factors, the groups with the highest quartile of TyG, TyG-BMI, and TyG-WC had 1.48 times (95%CI: 1.07-2.04), 3.71 times (95%CI: 2.67-5.15), and 4.07 times (95%CI: 2.89-5.73) higher risks of blood pressure abnormalities compared to the groups with the lowest quartile, respectively. Moreover, as the levels of TyG, TyG-BMI, and TyG-WC increased, the risk of blood pressure abnormalities gradually increased (P<0.05). A non-linear dose-response relationship was observed between TyG-BMI and the risk of blood pressure abnormalities (P overall trend<0.001, P non-linearity=0.002). Linear dose-response relationships were found between TyG and the risk of blood pressure abnormalities (P overall trend<0.001, P non-linearit =0.232), and between TyG-WC and the risk of blood pressure abnormalities (P overall trend<0.001, P non-linearity=0.224). CONCLUSIONS: Higher levels of TyG and its derivatives are associated with an increased risk of blood pressure abnormalities in adolescents, with linear or non-linear dose-response relationships.

Enantioselective Divergent Syntheses of Cephalotaxus Alkaloids: (-)-Cephalotaxine, (-)-Cephalotine B, and (-)-Fortuneicyclidins A and B.

A new strategy focusing on the last-stage asymmetric assembly of the ring D, which inherently possesses the densest part of stereogenic centers and functional groups in the A/B/C/D ring system of (-)-cephalotaxine, has been developed, in which a novel Rh-catalyzed asymmetric (2 + 3) annulation of tertiary enamides with enoldiazoacetates is designed and explored for enantioselective construction of the crucial cyclopentane ring D bearing a unique spirocyclic aza-quaternary stereocenter. Based on the expeditious access of chiral functionalized building block with the tetracyclic A/B/C/D ring system, a concise enantioselective total synthesis of (-)-cephalotaxine starting from readily available homopiperonyl alcohol has been achieved in nine steps with only two column chromatography purifications. Following the tactical introduction of the Meinwald rearrangement, enantioselective divergent syntheses of (-)-cephalotine B with an additional C3-O-C11 oxo-bridged bond (14 steps), (-)-fortuneicyclidin B with an unprecedented C3-C10 bond (14 steps), and its 2-epimer (-)-fortuneicyclidin A (16 steps) have been also accomplished for the first time.

ETHE1 Accelerates Triple-Negative Breast Cancer Metastasis by Activating GCN2/eIF2α/ATF4 Signaling.

Triple-negative breast cancer (TNBC) is the most fatal subtype of breast cancer; however, effective treatment strategies for TNBC are lacking. Therefore, it is important to explore the mechanism of TNBC metastasis and identify its therapeutic targets. Dysregulation of ETHE1 leads to ethylmalonic encephalopathy in humans; however, the role of ETHE1 in TNBC remains elusive. Stable cell lines with ETHE1 overexpression or knockdown were constructed to explore the biological functions of ETHE1 during TNBC progression in vitro and in vivo. Mass spectrometry was used to analyze the molecular mechanism through which ETHE1 functions in TNBC progression. ETHE1 had no impact on TNBC cell proliferation and xenograft tumor growth but promoted TNBC cell migration and invasion in vitro and lung metastasis in vivo. The effect of ETHE1 on TNBC cell migratory potential was independent of its enzymatic activity. Mechanistic investigations revealed that ETHE1 interacted with eIF2α and enhanced its phosphorylation by promoting the interaction between eIF2α and GCN2. Phosphorylated eIF2α in turn upregulated the expression of ATF4, a transcriptional activator of genes involved in cell migration and tumor metastasis. Notably, inhibition of eIF2α phosphorylation through ISRIB or ATF4 knockdown partially abolished the tumor-promoting effect of ETHE1 overexpression. ETHE1 has a functional and mechanistic role in TNBC metastasis and offers a new therapeutic strategy for targeting ETHE1-propelled TNBC using ISRIB.

Research Progresses of Tri-Allelic Patterns in Autosomal STR in Forensic DNA Analysis.

Tri-allelic pattern in autosomal STR is a common abnormal typing phenomenon in forensic DNA analysis, which brings difficulties and uncertainties to the evaluation of the evidence weight in actual cases. This paper reviews the types, formation mechanism, occurrence frequency, genetic pattern and quantitative evaluation of evidence of the tri-allelic pattern in autosomal STR in forensic DNA analysis. This paper mainly explains the formation mechanism and genetic patterns based on different types of tri-allelic pattern. This paper also discusses the determination of tri-allelic pattern and the quantitative method of evidence evaluation in paternity testing and individual identification. This paper aims to provide references for scientific and standardized analysis of this abnormal typing phenomenon in forensic DNA analysis.

[Relationship between skeletal muscle mass index and metabolic phenotypes of obesity in adolescents]. / é’å°‘å¹´éª¨éª¼è‚Œè´¨é‡æŒ‡æ•°ä¸Žè‚¥èƒ–ä»£è°¢è¡¨åž‹çš„å ³ç³».

OBJECTIVES: To study the relationship between skeletal muscle mass index (SMI) and metabolic phenotypes of obesity in adolescents, and to provide a basis for the prevention and control of adolescent obesity and related metabolic diseases. METHODS: A total of 1 352 adolescents aged 12 to 18 years were randomly selected by stratified cluster sampling in Yinchuan City from October 2017 to September 2020, and they were surveyed using questionnaires, physical measurements, body composition measurements, and laboratory tests. According to the diagnostic criteria for metabolic abnormalities and the definition of obesity based on the body mass index, the subjects were divided into four metabolic phenotypes: metabolically healthy normal weight, metabolically healthy obesity, metabolically unhealthy normal weight, and metabolically unhealthy obesity. The association between SMI and the metabolic phenotypes was analyzed using multivariate logistic regression. RESULTS: The SMI level in the metabolically unhealthy normal weight, metabolically healthy obesity, and metabolically unhealthy obesity groups was lower than that in the metabolically healthy normal weight group (P<0.001). Multivariate logistic regression analysis showed that after adjusting for gender and age, a higher SMI level was a protective factors for adolescents to develop metabolic unhealthy normal weight, metabolically healthy obesity, and metabolically unhealthy obesity phenotypes (OR=0.74, 0.60, and 0.54, respectively; P<0.001). CONCLUSIONS: Increasing SMI can reduce the risk of the development of metabolic unhealthy/obesity.

Combined angiogenesis and PD-1 inhibition for immunomodulatory TNBC: concept exploration and biomarker analysis in the FUTURE-C-Plus trial.

BACKGROUND: Immune checkpoint inhibitors had a great effect in triple-negative breast cancer (TNBC); however, they benefited only a subset of patients, underscoring the need to co-target alternative pathways and select optimal patients. Herein, we investigated patient subpopulations more likely to benefit from immunotherapy and inform more effective combination regimens for TNBC patients. METHODS: We conducted exploratory analyses in the FUSCC cohort to characterize a novel patient selection method and actionable targets for TNBC immunotherapy. We investigated this in vivo and launched a phase 2 trial to assess the clinical value of such criteria and combination regimen. Furthermore, we collected clinicopathological and next-generation sequencing data to illustrate biomarkers for patient outcomes. RESULTS: CD8-positivity could identify an immunomodulatory subpopulation of TNBCs with higher possibilities to benefit from immunotherapy, and angiogenesis was an actionable target to facilitate checkpoint blockade. We conducted the phase II FUTURE-C-Plus trial to assess the feasibility of combining famitinib (an angiogenesis inhibitor), camrelizumab (a PD-1 monoclonal antibody) and chemotherapy in advanced immunomodulatory TNBC patients. Within 48 enrolled patients, the objective response rate was 81.3% (95% CI, 70.2-92.3), and the median progression-free survival was 13.6 months (95% CI, 8.4-18.8). No treatment-related deaths were reported. Patients with CD8- and/or PD-L1- positive tumors benefit more from this regimen. PKD1 somatic mutation indicates worse progression-free and overall survival. CONCLUSION: This study confirms the efficacy and safety of the triplet regimen in immunomodulatory TNBC and reveals the potential of combining CD8, PD-L1 and somatic mutations to guide clinical decision-making and treatments. TRIAL REGISTRATION: ClinicalTrials.gov: NCT04129996 . Registered 11 October 2019.

Structures of mammalian GLD-2 proteins reveal molecular basis of their functional diversity in mRNA and microRNA processing.

The stability and processing of cellular RNA transcripts are efficiently controlled via non-templated addition of single or multiple nucleotides, which is catalyzed by various nucleotidyltransferases including poly(A) polymerases (PAPs). Germline development defective 2 (GLD-2) is among the first reported cytoplasmic non-canonical PAPs that promotes the translation of germline-specific mRNAs by extending their short poly(A) tails in metazoan, such as Caenorhabditis elegans and Xenopus. On the other hand, the function of mammalian GLD-2 seems more diverse, which includes monoadenylation of certain microRNAs. To understand the structural basis that underlies the difference between mammalian and non-mammalian GLD-2 proteins, we determine crystal structures of two rodent GLD-2s. Different from C. elegans GLD-2, mammalian GLD-2 is an intrinsically robust PAP with an extensively positively charged surface. Rodent and C. elegans GLD-2s have a topological difference in the ß-sheet region of the central domain. Whereas C. elegans GLD-2 prefers adenosine-rich RNA substrates, mammalian GLD-2 can work on RNA oligos with various sequences. Coincident with its activity on microRNAs, mammalian GLD-2 structurally resembles the mRNA and miRNA processor terminal uridylyltransferase 7 (TUT7). Our study reveals how GLD-2 structurally evolves to a more versatile nucleotidyltransferase, and provides important clues in understanding its biological function in mammals.

FAM46B is a prokaryotic-like cytoplasmic poly(A) polymerase essential in human embryonic stem cells.

Family with sequence similarity (FAM46) proteins are newly identified metazoan-specific poly(A) polymerases (PAPs). Although predicted as Gld-2-like eukaryotic non-canonical PAPs, the detailed architecture of FAM46 proteins is still unclear. Exact biological functions for most of FAM46 proteins also remain largely unknown. Here, we report the first crystal structure of a FAM46 protein, FAM46B. FAM46B is composed of a prominently larger N-terminal catalytic domain as compared to known eukaryotic PAPs, and a C-terminal helical domain. FAM46B resembles prokaryotic PAP/CCA-adding enzymes in overall folding as well as certain inter-domain connections, which distinguishes FAM46B from other eukaryotic non-canonical PAPs. Biochemical analysis reveals that FAM46B is an active PAP, and prefers adenosine-rich substrate RNAs. FAM46B is uniquely and highly expressed in human pre-implantation embryos and pluripotent stem cells, but sharply down-regulated following differentiation. FAM46B is localized to both cell nucleus and cytosol, and is indispensable for the viability of human embryonic stem cells. Knock-out of FAM46B is lethal. Knock-down of FAM46B induces apoptosis and restricts protein synthesis. The identification of the bacterial-like FAM46B, as a pluripotent stem cell-specific PAP involved in the maintenance of translational efficiency, provides important clues for further functional studies of this PAP in the early embryonic development of high eukaryotes.

Micrografting: An Old Dog Plays New Tricks in Obligate Plant Pathogens.

Micrografting, which was developed almost 50 years ago, has long been used for virus eradication, micropropagation, regeneration, rejuvenation, and graft compatibility. Recently, micrografting has been used for studies of long-distance trafficking and signaling of molecules between scions and rootstocks. The graft transmissiveness of obligate plant pathogens, such as viruses, viroids, and phytoplasmas, facilitated the use of micrografting to study biological indexing and pathogen transmission, pathogen-induced graft incompatibility, and screening for the pathogen resistance during the past 20 years. The present study provides comprehensive information on the latter subjects. Finally, prospects are proposed to direct further studies.

Discovery of a Novel Bloom's Syndrome Protein (BLM) Inhibitor Suppressing Growth and Metastasis of Prostate Cancer.

Prostate cancer (PCa) is a common cancer and a major cause of cancer-related death worldwide in men, necessitating novel targets for cancer therapy. High expression of Bloom's syndrome protein (BLM) helicase is associated with the occurrence and development of PCa. Therefore, the identification and development of new BLM inhibitors may be a new direction for the treatment of PCa. Here, we identified a novel inhibitor by molecular docking and put it to systematic evaluation via various experiments, AO/854, which acted as a competitive inhibitor that blocked the BLM-DNA interaction. Cellular evaluation indicated that AO/854-suppressed tumor growth and metastasis in PC3 cells by enhancing DNA damage, phosphorylating Chk1/Chk2, and altering the p53 signaling pathway. Collectively, the study highlights the potential of BLM as a therapeutic target in PCa and reveals a distinct mechanism by which AO/854 competitively inhibits the function of BLM.

ML216-Induced BLM Helicase Inhibition Sensitizes PCa Cells to the DNA-Crosslinking Agent Cisplatin.

Using standard DNA-damaging medicines with DNA repair inhibitors is a promising anticancer tool to achieve better therapeutic responses and reduce therapy-related side effects. Cell viability assay, neutral comet assay, western blotting (WB), and cell cycle and apoptosis analysis were used to determine the synergistic effect and mechanism of ML216, a Bloom syndrome protein (BLM) helicase inhibitor, and cisplatin (CDDP), a DNA-crosslinking agent, in PCa cells. Based on the online database research, our findings revealed that BLM was substantially expressed in PCa, which is associated with a bad prognosis for PCa patients. The combination of ML216 and CDDP improved the antiproliferative properties of three PCa cell lines. As indicated by the increased production of γH2AX and caspase-3 cleavage, ML216 significantly reduced the DNA damage-induced high expression of BLM, making PC3 more susceptible to apoptosis and DNA damage caused by CDDP. Furthermore, the combination of ML216 and CDDP increased p-Chk1 and p-Chk2 expression. The DNA damage may have triggered the ATR-Chk1 and ATM-Chk2 pathways simultaneously. Our results demonstrated that ML216 and CDDP combination therapy exhibited synergistic effects, and combination chemotherapy could be a novel anticancer tactic.

Application of Restriction Site-Associated DNA Sequencing (RAD-Seq) for Copy Number Variation and Triploidy Detection in Human.

At present, low-pass whole-genome sequencing (WGS) is frequently used in clinical research and in the screening of copy number variations (CNVs). However, there are still some challenges in the detection of triploids. Restriction site-associated DNA sequencing (RAD-Seq) technology is a reduced-representation genome sequencing technology developed based on next-generation sequencing. Here, we verified whether RAD-Seq could be employed to detect CNVs and triploids. In this study, genomic DNA of 11 samples was extracted employing a routine method and used to build libraries. Five cell lines of known karyotypes and 6 triploid abortion tissue samples were included for RAD-Seq testing. The triploid samples were confirmed by STR analysis and also tested by low-pass WGS. The accuracy and efficiency of detecting CNVs and triploids by RAD-Seq were then assessed, compared with low-pass WGS. In our results, RAD-Seq detected 11 out of 11 (100%) chromosomal abnormalities, including 4 deletions and 1 aneuploidy in the purchased cell lines and all triploid samples. By contrast, these triploids were missed by low-pass WGS. Furthermore, RAD-Seq showed a higher resolution and more accurate allele frequency in the detection of triploids than low-pass WGS. Our study shows that, compared with low-pass WGS, RAD-Seq has relatively higher accuracy in CNV detection at a similar cost and is capable of identifying triploids. Therefore, the application of this technique in medical genetics has a significant potential value.

[Alleles dropout patterns of Y-short tandem repeats in infertile males with Y chromosome microdeletions].

Y chromosomal short tandem repeat (Y-STR) typing is the most commonly used genetic technique in forensic studies. However, there may be a limit to the application of Y-STR in forensic science as Y-STR loci are subject to loss or variation caused by the higher chromosomal structures' spontaneous mutation rate. Located in the long arm of the Y chromosome, azoospermia factor (AZF) have been shown to participate in spermatogenesis and its deletion could cause infertility. However, little is known about the Y-STR dropout pattern in individuals with Y chromosome microdeletions. In this study, 85 infertile males with Y chromosome interstitial deletion were identified and special Y-STR allele dropout patterns were analyzed by employing a Y-STR Commercial Kit and a Y chromosome Deletion Kit. Results demonstrate that AZF a region deletion are related to DYS439-DYS389I-DYS389II alleles dropout, while AZF b region or c region deletions correlate to DYS448 allele dropout. Null DYS385-DYS392-DYS448 alleles were observed in AZF b+c+d region deletion individuals. While null DYS390-Y-GATA-H4-DYS385-DYS392-DYS448 alleles were observed in AZF a+b+c+d large region deletion individuals. Our data suggest that Y chromosome microdeletions may indicate specific Y-STR locus dropout patterns.

[The effect of cgVEGF164 on the growth of murine hair follicles].

Vascular endothelial growth factor (VEGF) is a dimeric glycoprotein that induces proliferation and migration of vascular endothelial cells as well as regulation of capillary formation around hair follicles which affects the growth and development of hair follicles. cgVEGF164 is a major splice variant of the cashmere goat VEGF-A gene, but its regulation on hair follicles is rarely known. In order to investigate the role of cgVEGF164 on the growth of murine hair follicles, we produced keratin 14 promoter-driven cgVEGF164 transgenic mice via pronuclear microinjection. Firstly, the diameter and density of hair follicles of transgenic mice were compared with non-transgenic control mice in paraffin sections stained by hematoxylin-eosin (H&E). Then, protein expression levels and the phosphorylation of ERK1/2, AKT1 and LEF1 were examined by Western blot. There are five positive individuals among the neonatal mice (positive rate is 8.5%). Compared with non-transgenic control mice, the diameter and density of hair follicles in transgenic mice are both obviously increased. The expression levels of P-ERK1/2/ERK1/2, P-AKT1/AKT1 and P-LEF1/LEF1 are significantly higher in transgenic mice than those in non-transgenic control mice. Based on these results, we conclude that cgVEGF164 as a growth factor can improve the growth of hair follicles which might be mediated by increasing the levels of ERK1/2, AKT1, and LEF1 protein phosphorylation.

Three GPI-anchored alkaline phosphatases are involved in the intoxication of Cry1Ca toxin to Spodoptera exigua larvae.

Glycosylphosphatidylinositol (GPI)-anchored alkaline phosphatase (ALP) isoforms are crucial for the intoxication of crystal proteins (Cry) to several insect species. We cloned five SeALPs from the larval midgut of Spodoptera exigua, a major pest of many crops. All five SeALPs contain a signal peptide at the N-terminus, a phosphatase domain, and a GPI-anchor site at the C-terminus. Additionally, the sequences encode two or three potential N-glycosylation sites. The five SeALPs were highly expressed at the larval stage, especially in the larval gut or Malpighian tubules. Ingestion over four consecutive days of double-stranded RNAs (dsRNAs) targeting SeALP1, SeALP2, SeALP3, SeALP4, and SeALP5 significantly reduced the corresponding mRNA levels by 60.0%, 40.0%, 65.6%, 48.1%, and 69.1% respectively, compared with the levels in control larvae that fed on non-specific dsRNA (dsEGFP). When larvae that previously ingested phosphate buffered saline (PBS)-, dsEGFP-, or five dsSeALPs-overlaid diets were then exposed to a diet containing Cry1Ca, the larval mortalities after six days were 70.0%, 71.8%, 49.1%, 54.9%, 65.3%, 52.5%, and 77.4%, respectively. ANOVA analysis revealed that the larvae that previously fed on the dsSeALP1-, dsSeALP2-, and dsSeALP4-overlaid diets had significantly lower mortalities than those that previously ingested the PBS-, dsEGFP-, dsSeALP3- and dsSeALP5-overlaid diets. The results suggest that SeALP1, SeALP2 and SeALP4 are involved in the intoxication of Cry1Ca to S. exigua larvae.

Construction of FGF21 knockout mouse models by the CRISPR/Cas9 system.

Fibroblast growth factors (FGFs) are multifunctional signal molecules between cells, regulating the various physiological functions of the organism. FGF21 is a regulatory factor of the FGF family and has been postulated to play important roles in hair follicle development and hair follicle growth cycle. To evaluate the roles of FGF21, we had established a FGF21 knockout mouse model, using the CRISPR/Cas9 technology. We had constructed a FGF21 targeting vector and microinjected it with Cas9 mRNA and gRNA into fertilized ova of FVB mice. The gRNA was designed to target the exon 1 of the endogenous mouse FGF21 gene. Three lines of Fgf21 -/- mice were obtained from these experiments, and confirmed to harbor Fgf21 -/- genotypes and null expression phenotype, using DNA sequencing, qRT-PCR and Western blotting. FGF21 mRNA and FGF21 protein were not detected in tissues of these Fgf21 -/- mice. Depilation and histochemistry analyses showed that the Fgf21 -/- mice had lower body weight, slower hair regrowth and poorer hair quantities and smaller hair follicles diameters, as compared to WT mice. The Fgf21 -/- mice reported here could provide a useful genetic model for future studies of FGF21 functions in hair follicle development and hair follicle growth cycle.

[Characterizing Dissolved Organic Matter (DOM) in Wastewater from Scale Pig Farms Using Three-Dimensional Excitation-Emission Matrices (3DEEM].

The properties of material composition in swine wastewater are closely related to its potential environmental effects, and it could provide theoretical bases for formulating scientific resource management measures to study the composition of organic matter in wastewater. In the present study, swine wastewater was directly collected from waste-retention basins in various scale pig farms with a different farming scale (based on the annual pig slaughter), namely Cheng Lin (CL, 5 000), Wu Yang-gao (WYG, 2 000), Wan Gu (WG, 20 000), and Zhang Bang (ZB, 24 000), located in Yujiang County of Jiangxi Province. The main purpose of this study was to characterize dissolved organic matter (DOM) in swine wastewater using three-dimensional excitation-emission matrices (3DEEM) and parallel factor analysis (PARAFAC). Results of all samples examined showed, with respect to CL and WYG farm, chemical oxygen demand (COD), total nitrogen (TN), ammonium nitrogen (NH+4), and dissolved organic carbon (DOC) concentration in swine wastewater was significantly higher than WG and ZB farm. Three DOM components, including two protein-like components (C1, C2) and one humic-like component (C3), were identified in wastewater using 3DEEM and PARAFAC. Results of linear regression showed, the fluorescence intensity of C1 linked significantly with C2 (p<0.001) and C3 (p<0.001), respectively, suggesting a same source or similar variation trend existed possibly between different DOM components. Furthermore, consistent with the variation trend of nutrient concentration in wastewater, fluorescence intensity of each DOM component in CL and WYG farm was significantly higher than WG and ZB farm. The total contribution of C1 and C2 to DOM in swine wastewater was CL (89.7%), WG (77.5%), WYG (87.9%), and ZB (72.9%), respectively, and the percentage of C3 was CL (10.3%), WG (22.5%), WYG (12.1%), and ZB (27.1%), respectively. Thus, the percentage of two protein-like components was significantly higher than humic-like in swine wastewater. Meanwhile, the fluorescence indices FI370 and humification index (HIX) of WG and ZB farm were higher than CL and WYG. In addition, Pearson correlation analysis showed that the effects of environmental parameters on fluorescence indices were different, and COD and DOC concentrations were significantly correlated with the fluorescence intensities of DOM components in swine wastewater. In summary, to a certain degree, the nutrient levels affected formation of fluorescence characteristics and DOM compositions in swine wastewater between different scale pig farms.

Diastereoselective and Enantioselective Synthesis of Unsymmetric ß,ß-Diaryl-α-Amino Acid Esters via Organocatalytic 1,6-Conjugate Addition of para-Quinone Methides.

A novel strategy based on phase transfer catalysis for the diastereoselective and enantioselective direct assembly of unsymmetric ß,ß-diaryl-α-amino acid esters via 1,6-conjugate addition of para-quinone methides and glycine derivatives is described. This protocol also provides an alternative route to the synthetically interesting functionalized chiral tetrahydroisoquinoline and its analogues.

Enantioselective Separation of 4,8-DHT and Phytotoxicity of the Enantiomers on Various Plant Species.

As a candidate for bioherbicide, 4,8-dihydroxy-1-tetralone (4,8-DHT) was isolated from Caryospora callicarpa epicarp and its two enantiomers, S-(+)-isosclerone and R-(-)-regiolone, were separated by chiral high-performance liquid chromatography (HPLC) on a Chiralcel OD column with chiral stationary phase (CSP)-coated cellulose-tris(3,5-dimethylphenylcarbamate). Then, the phytotoxicity of 4,8-DHT and its enantiomers toward the seeds germination and seedling growth of the five tested plant species, including lettuce (Latuca sativa), radish (Raphanus sativus), cucumber (Cucumis sativus), onion (Allium cepa), and wheat (Triticum aestivum), were investigated and the results indicated a hormesis at low concentration of 4,8-DHT and its enantiomers, but a retardant effect at high concentration. Between the two enantiomers of 4,8-DHT, the S-(+)-isosclerone was more toxic to seeds germination and seedling growth of the five tested plant species than the R-(-)-regiolone, and also the phytotoxicity of S-(+)-isosclerone varied with different plants. For example, S-(+)-isosclerone was the most active to seedling growth of lettuce, indicating that S-(+)-isosclerone had specific effects on different organisms. Thus, all of the chirality and concentration of 4,8-DHT, as well as the affected plant species, need to be taken into consideration in the development and utilization of 4,8-DHT.