Metabolomics of repetitive myocardial stunning in chronic multivessel coronary artery stenosis: Effect of non-selective and selective ß1-receptor blockers.

Chronic coronary artery stenosis can lead to regional myocardial dysfunction in the absence of myocardial infarction by repetitive stunning, hibernation or both. The molecular mechanisms underlying repetitive stunning-associated myocardial dysfunction are not clear. We used non-targeted metabolomics to elucidate responses to chronically stunned myocardium in a canine model with and without ß-adrenergic blockade treatment. After development of left ventricular systolic dysfunction induced by ameroid constrictors on the coronary arteries, animals were randomized to 3 months of placebo, metoprolol or carvedilol. We compared these two ß-blockers with their different ß-adrenergic selectivities on myocardial function, perfusion and metabolic pathways involved in tissue undergoing chronic stunning. Control animals underwent sham surgery. Dysfunction in stunned myocardium was associated with reduced fatty acid oxidation and enhanced ketogenic amino acid metabolism, together with alterations in mitochondrial membrane phospholipid composition. These changes were consistent with impaired mitochondrial function and were linked to reduced nitric oxide and peroxisome proliferator-activated receptor signalling, resulting in a decline in adenosine monophosphate-activated protein kinase. Mitochondrial changes were ameliorated by carvedilol more than metoprolol, and improvement was linked to nitric oxide and possibly hydrogen sulphide signalling. In summary, repetitive myocardial stunning commonly seen in chronic multivessel coronary artery disease is associated with adverse metabolic remodelling linked to mitochondrial dysfunction and specific signalling pathways. These changes are reversed by ß-blockers, with the non-selective inhibitor having a more favourable impact. This is the first investigation to demonstrate that ß-blockade-associated improvement of ventricular function in chronic myocardial stunning is associated with restoration of mitochondrial function. KEY POINTS: The mechanisms responsible for the metabolic changes associated with repetitive myocardial stunning seen in chronic multivessel coronary artery disease have not been fully investigated. In a canine model of repetitive myocardial stunning, we showed that carvedilol, a non-selective ß-receptor blocker, ameliorated adverse metabolic remodelling compared to metoprolol, a selective ß1-receptor blocker, by improving nitric oxide synthase and adenosine monophosphate protein kinase function, enhancing calcium/calmodulin-dependent protein kinase, probably increasing hydrogen sulphide, and suppressing cyclic-adenosine monophosphate signalling. Mitochondrial fatty acid oxidation alterations were ameliorated by carvedilol to a larger extent than metoprolol; this improvement was linked to nitric oxide and possibly hydrogen sulphide signalling. Both ß-blockers improved the cardiac energy imbalance by reducing metabolites in ketogenic amino acid and nucleotide metabolism. These results elucidated why metabolic remodelling with carvedilol is preferable to metoprolol when treating chronic ischaemic left ventricular systolic dysfunction caused by repetitive myocardial stunning.

Control of coronary vascular resistance by eicosanoids via a novel GPCR.

Arachidonic acid metabolites epoxyeicosatrienoates (EETs) and hydroxyeicosatetraenoates (HETEs) are important regulators of myocardial blood flow and coronary vascular resistance (CVR), but their mechanisms of action are not fully understood. We applied a chemoproteomics strategy using a clickable photoaffinity probe to identify G protein-coupled receptor 39 (GPR39) as a microvascular smooth muscle cell (mVSMC) receptor selective for two endogenous eicosanoids, 15-HETE and 14,15-EET, which act on the receptor to oppose each other's activity. The former increases mVSMC intracellular calcium via GPR39 and augments coronary microvascular resistance, and the latter inhibits these actions. Furthermore, we find that the efficacy of both ligands is potentiated by zinc acting as an allosteric modulator. Measurements of coronary perfusion pressure (CPP) in GPR39-null hearts using the Langendorff preparation indicate the receptor senses these eicosanoids to regulate microvascular tone. These results implicate GPR39 as an eicosanoid receptor and key regulator of myocardial tissue perfusion. Our findings will have a major impact on understanding the roles of eicosanoids in cardiovascular physiology and disease and provide an opportunity for the development of novel GPR39-targeting therapies for cardiovascular disease.

RsmA3 modulates RpoS through the RetS-Gac-Rsm signalling pathway in response to H2 O2 stress in the phytopathogen Pseudomonas syringae.

Reactive oxygen species are a fatal challenge to the plant pathogenic bacterium Pseudomonas syringae. In this study, we reveal that the global regulatory protein RsmA3 from the RetS-Gac/Rsm signalling pathway modulates RpoS in the early-log growth phase in the P. syringae wild-type strain MB03, thereby regulating oxidative tolerance to H2 O2 and ultimately affecting pathogenicity to the host plant. Following increased H2 O2 by external addition or endogenous induction by menadione, the resistance of the mutant strain ΔretS to H2 O2 is significantly enhanced due to rapid increases in the transcription of Rsm-related non-coding small RNAs (nc sRNAs), a sigma factor RpoS, and H2 O2 -detoxifying enzymes. Moreover, the ΔretS mutant is significantly less pathogenic in cucumber leaves. Seven Rsm-related nc sRNAs (namely, rsmZ, rsmY and rsmX1-5 ) show functional redundancy in the RetS-Gac-Rsm signalling pathway. External addition of H2 O2 stimulates increases in the transcription of both rsmY and rsmZ. Thus, we propose a regulatory model of the RetS-Gac-Rsm signalling pathway in P. syringae MB03 for the regulation of H2 O2 tolerance and phytopathogenicity in the host plant.

Genome-wide survey and functional analysis reveal TCF21 promotes chicken preadipocyte differentiation by directly upregulating HTR2A.

BACKGROUND/AIM: Previously, we showed that transcription factor 21 (TCF21) promotes chicken preadipocyte differentiation. However, the genome-wide TCF21 binding sites and its downstream target genes in chicken adipogenesis were unknown. METHODS: ChIP-Seq and RNA-Seq were used to screen candidate targets of TCF21. qPCR and luciferase reporter assay were applied to verify the sequencing results. Western blotting, oil red-O staining and pharmacological treatments were performed to investigate the function of 5-hydroxytryptamine receptor 2A (HTR2A), one of the bonafide direct downstream binding targets of TCF21. RESULTS: A total of 94 candidate target genes of TCF21 were identified. ChIP-qPCR, RT-qPCR, and luciferase reporter assay demonstrated that HTR2A is one of the bonafide direct downstream binding targets of TCF21. HTR2A expression in adipose tissue was upregulated in fat line broilers. Also, the abundance of HTR2A gradually increased during the adipogenesis process. Interestingly, pharmacological enhancement or inhibition of HTR2A promoted or attenuated the differentiation of preadipocytes, respectively. Furthermore, HTR2A inhibition impaired the TCF21 promoted adipogenesis. CONCLUSIONS: We profiled the genome-wide TCF21 binding sites in chicken differentiated preadipocytes revealing HTR2A as the direct downstream target of TCF21 in adipogenesis.

Genetic parameters estimation and genome-wide association studies for internal organ traits in an F2 chicken population.

Chicken internal organs are indispensable parts of the body, but their genetic architectures have not been commonly understood. Herein, we estimated the genetic parameters for heart weight (HW), liver weight (LW), spleen weight (SpW), testis weight (TW), glandular stomach weight (GSW), muscular stomach weight (MSW) and identified single nucleotide polymorphisms (SNPs) and potential candidate genes associated with internal organ weights in an F2 population constructed by crossing broiler cocks derived from Arbor Acres with high abdominal fat content and Baier layer dams (a Chinese native breed). The restricted maximum likelihood (REML) method was applied for genetic parameters estimation of internal organ weights using GCTA software. The results showed that heritabilities of internal organ traits ranged from 0.336 to 0.673 and most of the genetic and phenotypic correlations amongst internal organs weights were positive. A genome-wide association study (GWAS) was performed based on a mixed linear model (MLM) in GEMMA software. Genotypic data were produced from the whole genome re-sequenced (26 F0 individuals were re-sequenced at 10 × coverage; 519 F2 individuals were re-sequenced at 3 × coverage). A total of 7,890,258 SNPs remained to be analysed after quality control and genotype imputation. The GWAS results indicated that significant SNPs responsible for internal organ traits were scattered on the different chicken chromosomes 1-5, 8, 11, 14, 16, 18, 19 and 27. Amongst the annotated genes, fibronectin type III domain containing 3A (FNDC3A), LOC101748122, membrane palmitoylated protein 6 (MPP6), LOC107049584 and KAT8 regulatory NSL complex subunit 1 (KANSL1) were the most promising candidates for internal organ traits. The findings will provide instrumental information for understanding the genetic basis of internal organ development.

Mechanism and potential treatment of the "no reflow" phenomenon after acute myocardial infarction: role of pericytes and GPR39.

The "no reflow" phenomenon, where the coronary artery is patent after treatment of acute myocardial infarction (AMI) but tissue perfusion is not restored, is associated with worse outcome. The mechanism of no reflow is unknown. We hypothesized that pericytes contraction, in an attempt to maintain a constant capillary hydrostatic pressure during reduced coronary perfusion pressure, causes capillary constriction leading to no reflow and that this effect is mediated through the orphan receptor, GPR39, present in pericytes. We created AMI (coronary occlusion followed by reperfusion) in GPR39 knock out mice and littermate controls. In a separate set of experiments, we treated wild-type mice undergoing coronary occlusion with vehicle or VC43, a specific inhibitor of GPR39, before reperfusion. We found that no reflow zones were significantly smaller in the GPR39 knockouts compared with controls. Both no reflow and infarct size were also markedly smaller in animals treated with VC43 compared with vehicle. Immunohistochemistry revealed greater capillary density and larger capillary diameter at pericyte locations in the GPR39-knockout and VC43-treated mice compared with controls. We conclude that GPR39-mediated pericyte contraction during reduced coronary perfusion pressure causes capillary constriction resulting in no reflow during AMI and that smaller no reflow zones in GPR39-knockout and VC43-treated animals are associated with smaller infarct sizes. These results elucidate the mechanism of no reflow in AMI, as well as providing a therapeutic pathway for the condition.NEW & NOTEWORTHY The mechanism of "no reflow" phenomenon, where the coronary artery is patent after treatment of acute myocardial infarction but tissue perfusion is not restored, is unknown. This condition is associated with worse outcome. Here, we show that GPR39-mediated pericyte contraction during reduced coronary perfusion pressure causes capillary constriction resulting in no reflow. Smaller no-reflow zones in GPR39-knockout animals and those treated with a GPR39 inhibitor are associated with smaller infarct size. These results could have important therapeutic implications.

Ranolazine may exert its beneficial effects by increasing myocardial adenosine levels.

We hypothesized that ranolazine-induced adenosine release is responsible for its beneficial effects in ischemic heart disease. Sixteen open-chest anesthetized dogs with noncritical coronary stenosis were studied at rest, during dobutamine stress, and during dobutamine stress with ranolazine. Six additional dogs without stenosis were studied only at rest. Regional myocardial function and perfusion were assessed. Coronary venous blood was drawn. Murine endothelial cells and cardiomyocytes were incubated with ranolazine and adenosine metabolic enzyme inhibitors, and adenosine levels were measured. Cardiomyocytes were also exposed to dobutamine and dobutamine with ranolazine. Modeling was employed to determine whether ranolazine can bind to an enzyme that alters adenosine stores. Ranolazine was associated with increased adenosine levels in the absence (21.7 ± 3.0 vs. 9.4 ± 2.1 ng/mL, P < 0.05) and presence of ischemia (43.1 ± 13.2 vs. 23.4 ± 5.3 ng/mL, P < 0.05). Left ventricular end-systolic wall stress decreased (49.85 ± 4.68 vs. 57.42 ± 3.73 dyn/cm2, P < 0.05) and endocardial-to-epicardial myocardial blood flow ratio tended to normalize (0.89 ± 0.08 vs. 0.76 ± 0.10, P = nonsignificant). Adenosine levels increased in cardiac endothelial cells and cardiomyocytes when incubated with ranolazine that was reversed when cytosolic-5'-nucleotidase (cN-II) was inhibited. Point mutation of cN-II aborted an increase in its specific activity by ranolazine. Similarly, adenosine levels did not increase when cardiomyocytes were incubated with dobutamine. Modeling demonstrated plausible binding of ranolazine to cN-II with a docking energy of -11.7 kcal/mol. We conclude that the anti-adrenergic and cardioprotective effects of ranolazine-induced increase in tissue adenosine levels, likely mediated by increasing cN-II activity, may contribute to its beneficial effects in ischemic heart disease.NEW & NOTEWORTHY Ranolazine is a drug used for treatment of angina pectoris in patients with ischemic heart disease. We discovered a novel mechanism by which this drug may exhibit its beneficial effects. It increases coronary venous levels of adenosine both at rest and during dobutamine-induced myocardial ischemia. Ranolazine also increases adenosine levels in endothelial cells and cardiomyocytes in vitro, by principally increasing activity of the enzyme cytosolic-5'-nucleotidase. Adenosine has well-known myocardial protective and anti-adrenergic properties that may explain, in part, ranolazine's beneficial effect in ischemic heart disease.

Genome-wide association study for plasma very low-density lipoprotein concentration in chicken.

The plasma very low-density lipoprotein (VLDL) concentration is an effective blood biochemical indicator that could be used to select lean chicken lines. In the current study, we used Genome-wide association study (GWAS) method to detect SNPs with significant effects on plasma VLDL concentration. As a result, 38 SNPs significantly associated with plasma VLDL concentration were identified using at least one of the three mixed linear model (MLM) packages, including GRAMMAR, EMMAX and GEMMA. Nearly, all these SNPs with significant effects on plasma VLDL concentration (except Gga_rs16160897) have significantly different allele frequencies between lean and fat lines. The 1-Mb regions surrounding these 38 SNPs were extracted, and twelve important regions were obtained after combining the overlaps. A total of 122 genes in these twelve important regions were detected. Among these genes, LRRK2, ABCD2, TLR4, E2F1, SUGP1, NCAN, KLF2 and RAB8A were identified as important genes for plasma VLDL concentration based on their basic functions. The results of this study may supply useful information to select lean chicken lines.

From Microscopy to Genomic Approach in Soil Biodiversity Assessment.

Soil biota represents a major component of the earth's biodiversity and for over 200 years, the microscopy approach was the only way to explore it. In the last decade, the DNA-based technique has been adopted in soil ecology. Due to the rapid development of cutting-edge technology, the field is transitioning from barcoding individuals to metabarcoding communities. With the advent of next-generation sequencing and a rapid decline in sequencing cost, it has become feasible to assess soil biodiversity at species level. This review article summarizes current approaches in soil biodiversity research along with their advantages and disadvantages.

Differential expression of six chicken genes associated with fatness traits in a divergently selected broiler population.

A genome-wide association study has shown a number of chicken (Gallus gallus) single nucleotide polymorphism (SNP) markers to be significantly associated with abdominal fat content in Northeast Agricultural University (NEAU) broiler lines selected divergently for abdominal fat content (NEAUHLF). The six significant SNPs are located in the kinase insert domain receptor (KDR), tumor suppressor candidate 3 (TUSC3), phosphoribosyl pyrophosphate amidotransferase (PPAT), exocyst complex component 1 (EXOC1), v-myb myeloblastosis viral oncogene homolog (avian)-like 2 (MYBL2) and KIAA1211 (undefined) genes. In this study, the expression levels of these genes were investigated in both abdominal fat and liver tissues using 32 14th generation chickens from the NEAUHLF. The levels of expression of KDR in abdominal fat and KDR and TUSC3 in liver differed significantly between the two lines. The expression level of KDR in the abdominal fat was significantly correlated with the abdominal fat weight (AFW) and abdominal fat percentage (AFP). The expression levels of KDR, TUSC3 and PPAT in liver were significantly correlated with AFW and AFP, indicating that the six genes, especially KDR and TUSC3, could be associated with fat traits in domestic chickens. This study could provide insight into the mechanisms underlying the formation of abdominal fat in chickens.

Changes in Plasma Lipid Levels and Antioxidant Activities in Rats after Supplementation of Obtusifolin.

Obtusifolin, an anthraquinone from Cassia obtusifolia seeds, has been reported to reduce blood lipid levels in diabetic rats induced by streptozocin. However, it remains unclear whether obtusifolin possesses a lipid-lowering effect on hyperlipidemia caused by a high-fat diet. Moreover, hyperlipidemia is known to impair the endothelial function by causing oxidative stress. Therefore, in the present study, we investigated the antidyslipidemic and antioxidant effects of obtusifolin in hyperlipidemic rats induced by a high-fat diet. Rats with oral fat emulsion were used as our hyperlipidemic model. We measured the body weight of the rats, serum total cholesterol, triglycerides, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol, as well as nitric oxide, malondialdehyde, and superoxide dismutase. Our results showed that oral obtusifolin application significantly reversed the changes induced by hyperlipidemia in body weight, total cholesterol, triglyceride, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol. Furthermore, obtusifolin treatment increased serum superoxide dismutase and nitric oxide, but reduced malondialdehyde. Collectively, our findings suggest that obtusifolin may improve hyperlipidemia by enhancing antioxidant activity. This study indicates a potential therapeutic importance of obtusifolin for ameliorating lipid dysfunction induced by a high-fat diet.

[3-D fluorescence properties of river with great flow rate].

In the present study, the three-dimensional fluorescence spectra of River A with great flow rate were investigated. The results showed that there existed three unambiguous peaks in the excitation-emission matrix of River A at lambda(ex)/lambda(em) of around 230/340, 280/320 and 250/450 nm respectively. The fluorescence intensity varied significantly and had sharp fluctuation sometimes. But the COD(Mn) of the samples remained quite stable. This study indicated that fluorescence technique could demonstrate the pollution in the water bodies with great flow rate and furthermore make up for the deficiency of the conventional parameters related to organic pollution, i. e. invalidation to exhibit the components of pollutants. It is a good tool for the early-warning of the water quality.

Distinct populations of lateral preoptic nucleus neurons jointly contribute to depressive-like behaviors through divergent projections in male mice.

The lateral preoptic area (LPO) is a component of the hypothalamus involved in various physiological functions including sleep-wakefulness transition, thermoregulation, and water-salt balance. In this study, we discovered that distinct LPO excitatory neurons project separately to the aversive processing center lateral habenula (LHb) and the reward processing hub ventral tegmental area (VTA). Following chronic restraint stress (CRS), the LHb-projecting and VTA-projecting LPO neurons exhibited increased and decreased neuronal activities, respectively. Optogenetic activation of LHb-projecting LPO excitatory neurons and LPO excitatory neuronal terminals within LHb evoked aversion and avoidance behaviors, while activation of VTA-projecting LPO excitatory neurons and LPO excitatory neuronal terminals within VTA produced preference and exploratory behaviors in mice. Furthermore, either optogenetic inhibition of LHb-projecting LPO excitatory neurons or activation of VTA-projecting LPO excitatory neurons during CRS effectively prevented the development of depressive-like behaviors. Our study unveils, for the first-time, divergent pathways originating from LPO that regulate opposite affective states in mice and implicates that an imbalance of their activities could lead to depressive-like behaviors. These circuitries represent promising therapeutic targets to relieve emotional dysfunctions in neuropsychiatric disorders.

HBP1 promotes chicken preadipocyte proliferation via directly repressing SOCS3 transcription.

Preadipocyte proliferation is an essential process in adipose development. During proliferation of preadipocytes, transcription factors play crucial roles. HMG-box protein 1 (HBP1) is an important transcription factor of cellular proliferation. However, the function and underlying mechanisms of HBP1 in the proliferation of preadipocytes remain unclear. Here, we found that the expression level of HBP1 decreased first and then increased during the proliferation of chicken preadipocytes. Knockout of HBP1 could inhibit the proliferation of preadipocytes, while overexpression of HBP1 could promote the proliferation of preadipocytes. ChIP-seq data showed that HBP1 had the unique DNA binding motif in chicken preadipocytes. By integrating ChIP-Seq and RNA-Seq, we revealed a total of 3 candidate target genes of HBP1. Furthermore, the results of ChIP-qPCR, RT-qPCR, luciferase reporter assay and EMSA showed that HBP1 could inhibit the transcription of suppressor of cytokine signaling 3 (SOCS3) by binding to its promoter. Moreover, we confirmed that SOCS3 can mediate the regulation of HBP1 on the proliferation of preadipocytes through RNAi and rescue experiments. Altogether, these data demonstrated that HBP1 directly targets SOCS3 to regulate chicken preadipocyte proliferation. Our findings expand the transcriptional regulatory network of preadipocyte proliferation, and they will be helpful in formulating a molecular breeding scheme to control excessive abdominal fat deposition and to improve meat quality in chickens.

Comparative analyses of laying performance and follicular development characteristics between fat and lean broiler lines.

The deposition of high levels of fat in broiler breeder hens can have a profound impact on follicular development and laying performance. This study was formulated with the goal of comparing egg production and follicular development characteristics at different laying stages in the Northeast Agricultural University broiler lines divergently selected for abdominal fat content (NEAUHLF). The egg production was analyzed using the birds from the 19th to 24th generations of NEAUHLF; the follicular development characteristics were analyzed by hematoxylin-eosin staining and quantitative real-time polymerase chain reaction using the birds from the 24th generation of NEAUHLF. The results showed that the age at first egg of lean hens was significantly earlier than that of fat hens in this study. While no significant differences in total egg output from the first egg to 50 wk of age were noted when comparing these 2 chicken lines, lean hens laid more eggs from the first egg to 35 wk of age relative to fat hens, whereas fat hens laid more eggs from wk 36 to 42 and 43 to 50 relative to their lean counterparts. No differences in ovarian morphology and small yellow follicle (SYF) histological characteristics were noted when comparing these 2 chicken lines at 27 wk of age. At 35 and 52 wk of age, however, lean hens exhibited significantly lower ovarian weight, ovarian proportion values, numbers of hierarchical follicles, hierarchical follicle weight, and SYF granulosa layer thickness as compared to fat hens, together with a significant increase in the number of prehierarchical follicles relative to those in fat hens. Gene expression analyses suggested that follicle selection was impaired in the fat hens in the early laying stage, whereas both follicle selection and maturation were impaired in the lean hens in the middle and late laying stages. Overall, these data highlight that fat deposition in broiler hens can have a range of effects on follicular development and egg production that are laying stage-dependent.

CTGF Inhibits the Differentiation of Chicken Preadipocytes via the TGFß/Smad3 Signaling Pathway or by Inducing the Expression of ACTG2.

Chicken is the main source of protein for humans in most parts of the world. However, excessive fat deposition in chickens has become a serious problem. This adversely affects the growth of chickens and causes economic losses. Fat formation mainly occurs through preadipocyte differentiation, and excessive fat deposition results from the accumulation of preadipocytes after differentiation. Our previous studies have found that the connective tissue growth factor (CTGF) may be an important candidate gene for fat deposition. However, its function and mechanism in preadipocyte differentiation are still unclear. In this study, the RT-qPCR and Western blot results showed that the expression of CTGF mRNA and protein in the abdominal adipose of lean chickens was significantly higher than that of fat chickens. Therefore, we studied the function and mechanism of the CTGF in the differentiation of chicken preadipocytes. Functionally, the CTGF inhibited the differentiation of chicken preadipocytes. Mechanistically, the CTGF mediated the TGFß1/Smad3 signaling pathway, thereby inhibiting the differentiation of chicken preadipocytes. In addition, we used the unique molecular identifier (UMI) RNA-Seq technology to detect genes that can be regulated by the CTGF in the whole genome. Through transcriptome data analysis, we selected actin gamma 2 (ACTG2) as a candidate gene. Regarding the function of the ACTG2 gene, we found that it inhibited the differentiation of chicken preadipocytes. Furthermore, we found that the CTGF can inhibit the differentiation of preadipocytes through the ACTG2 gene. In summary, this study found the CTGF as a new negative regulator of chicken preadipocyte differentiation. The results of this study help improve the understanding of the molecular genetic mechanism of chicken adipose tissue growth and development and also have reference significance for the study of human obesity.

[Fluorescence fingerprint--a novel tool of quality control of chemical reagents].

Product quality control is crucial for industrial production, but there is lack of simple and effective detect methods. In this study, the chromatographically pure N-hexane from different manufacturers and same manufacturers with different batches was detected with fluorescence fingerprint technology. The results showed that the fluorescence fingerprints of all samples were different from each other. The numbers of fluorescence peaks of the fingerprints of the famous international manufacturer was stable and the intensity was low. The chromatographically pure N-hexane made in China generally had more peaks, higher intensities and greater changes as compared to the imported product. This indicated that the domestic products had more impurities with high concentration and the product quality was unstable. The study showed that the fluorescence fingerprint can be used as a novel method for quality control of chemical reagents.

[Comparison of three-dimensional fluorescence characteristics of two isomers: phenanthrene and anthrancene].

In recent years, three-dimensional fluorescence spectrometry has been widely used to study the transportation and transformation of the environment pollutants. But little understanding about the relationship between fluorescence characteristics and molecular structure restricts its application. In the present paper, the excitation-emission matrix (EEM) of the typical aromatic pollutants and isomers, phenanthrene and anthracene were studied. The result showed that there existed a peak locating at lambda ex/lambdaem = 225/340 nm in the EEM of both phenanthrene and anthracene. Furthermore, the peaks at 275/360 nm of phenanthrene located quite close to the peak of anthracene at 285/360 nm. However, the difference between the EEM of phenanthrene and anthracene was significant. There existed the third fluorescence peak at 275/340 nm and the most intensive peak at 225/340 nm in the EEM of phenanthrene. The EEM of anthracene was more complicated. The most intensive peaks located at lambda ex,/lambdaem = 250/ 380, 250/400 and 250/425 nm respectiveoy. In addition, the fluorescence intensity of anthracene at 225/340 nm was about 1. 63 times that of phenanthrene when their concentrations were about 0. 058 1 mg L-1. The orbital energy gap of the frontier molecules of phenanthrene and anthracene were 4. 779 and 3. 621 eV respectively according to the density functional theory. Owe to the smaller energy gap and better symmetry of electron cloud, anthracene was easier to be excited under the excitation of longer wavelength with higher fluorescence intensity. The density functional theory is a good tool to estimate the luminous capability of organic matters.

[Fluorescence properties of municipal wastewater with industrial wastewater as major components].

The present paper studied fluorescence fingerprint properties of the municipal wastewater with industrial wastewater as major components. There existed three typical fluorescence peaks in the excitation-emission matrix of the municipal wastewater, locating at about lambda(ex)/lambda(em) of 275/310, 230/340 and 220/310 nm respectively. The wastewater didn't display typical protein-like fluorescence as the municipal wastewater with domestic sewage as major component. The fluorescence intensity of the wastewater was quite high with remarkable difference between workday and weekend. These might relate to the high content of industrial wastewater. The advantages of the fluorescence fingerprint such as easy and fast measurement and rich information about the components of wastewater make it a novel tool in water quality monitoring and early-warning.

Mechanisms of the "No-Reflow" Phenomenon After Acute Myocardial Infarction: Potential Role of Pericytes.

Pericytes contract during myocardial ischemia resulting in capillary constriction and no reflow. Reversing pericyte contraction pharmacologically reduces no reflow and infarct size. These findings open up an entire new venue of research aimed at altering pericyte function in myocardial ischemia and infarction.