Unveiling the overlooked threat: antibiotic resistance in groundwater near an abandoned sulfuric acid plant in Xingyang, China.

Groundwater near a sulfuric acid plant in Xingyang, Henan, China was sampled from seven distinct sites to explore the prevalence of antibiotic resistance genes (ARGs) and mobile genetic elements (MGEs). Results showed that genes aadA, blaCTX-M, tetA, qnrA, and sul1 were detected with 100% frequency followed by aac(6')-Ib (85.71%), ermB (85.71%), and tetX (71.42%). Most abundant ARGs were sul1 in LSA2 (1.15 × 1011 copies/mL), tetA in LSA6 (4.95 × 1010 copies/mL), aadA in LSA2 (4.56 × 109 copies/mL), blaCTX-M in LSA4 (1.19 × 109 copies/mL), and ermB in LSA5 (1.07 × 109 copies/mL). Moreover, in LSA2, intl1 as a marker of class 1 integron emerged as the most abundant gene as part of MGE (2.25 × 1011 copies/mL), trailed by ISCR1 (1.57 × 109 copies/mL). Environmental factors explained 81.34% of ARG variations, with a strong positive correlation between the intl2 and blaCTX-M genes, as well as the ISCR1 gene and qnrA, tetA, intl2, and blaCTX-M. Furthermore, the intI1 gene had a strong positive connection with the aadA, tetA, and sul1 genes. Moreover, the aac(6')-Ib gene was associated with As, Pb, Mg, Ca, and HCO3-. The intl2 gene was also shown to be strongly associated with Cd. Notably, network analysis highlighted blaCTX-M as the most frequently appearing gene across networks of at least five genera. Particularly, Lactobacillus, Plesiomonas, and Ligilactobacillus demonstrated correlations with aadA, qnrA, blaCTX-M, intI2, and ISCR1. Based on 16S rRNA sequencing, the dominant phyla were Proteobacteria, Firmicutes, Bacteroidota, Acidobacteriota, and Actinobacteriota, with dominant genera including Pseudomonas, Ligilactobacillus, Azoarcus, Vogesella, Streptococcus, Plesiomonas, and Ferritrophicum. These findings enhance our understanding of ARG distribution in groundwater, signaling substantial contamination by ARGs and potential risks to public health.

Recent progress and prospects for chain elongation of transforming biomass waste into medium-chain fatty acids.

Chain elongation technology utilises microorganisms in anaerobic digestion to transform waste biomass into medium-chain fatty acids that have greater economic value. This innovative technology expands upon traditional anaerobic digestion methods, requiring abundant substrates that serve as electron donors and acceptors, and inoculating microorganisms with chain elongation functions. While this process may result in the production of by-products and elicit competitive responses, toxicity suppression of microorganisms by substrates and products remains a significant obstacle to the industrialisation of chain elongation technology. This study provides a comprehensive overview of existing research on widely employed electron donors and their synthetic reactions, competitive reactions, inoculum selection, toxicity inhibition of substrates and products, and increased chain elongation approaches. Additionally, it presents actionable recommendations for future research and development endeavours in this domain, intending to inspire and guide researchers in advancing the frontiers of chain elongation technology.

Jinfeng pills ameliorate premature ovarian insufficiency induced by cyclophosphamide in rats and correlate to modulating IL-17A/IL-6 axis and MEK/ERK signals.

ETHNOPHARMACOLOGICAL RELEVANCE: Jinfeng Pill (JFP) is a classical Chinese medicine formula and composed of 9 herbs, including Epimedium brevicornu Maxim (Yinyanghuo), Cervus elaphus Linnaeus (Lurong), Panax ginseng C.A.Mey. (Renshen), Equus asinus (EJiao), Ligustrum lucidum W.T.Aiton (Nvzhenzi), Reynoutria multiflora (Thunb.) Moldenke (Heshouwu), Curculigo orchioides Gaertn (Xianmao), Neolitsea cassia (L.) Kosterm. (Rougui) and Leonurus japonicus Houtt. (Yimucao). The formula is clinically used to regulate menstrual cycle and alleviate polycystic ovarian syndrome due to its capabilities of ovulation induction. It is therefore presumed that JFP could be used for the therapy of premature ovarian insufficiency (POI) but the assumed efficacy has not been fully substantiated in experiment. AIM OF STUDY: To evaluate the effectiveness of JFP on cyclophosphamide (CTX)-induced POI and preliminarily explore its potential mechanisms of action. MATERIAL AND METHODS: An experimental rat model of POI was established by using CTX induction to assess the efficacy of JFP. The potential targets of action for JFP alleviating POI were predicted by the combination of network pharmacology and transcriptomics and finally validating by RT-qPCR and Western blot. RESULTS: JFP alleviated the damages of ovarian tissue induced by CTX in the rat model of POI via significantly decreasing serum levels of FSH and LH and the ratio of FSH/LH and increasing the levels of E2 and AMH, accompanied with promoting ovarian folliculogenesis and follicle maturity and reversing the depletion of follicle pool. With the analysis of network pharmacology, pathways in cancer, proteoglycans in cancer, PI3K-AKT, TNF and FoxO signaling pathways were predicted to be influenced by JFP. The results of RNA-seq further revealed that IL-17 signaling pathway was the most important pathway regulated by both CTX and JFP, following by transcriptional misregulation in cancer and proteoglycans in cancer. Combining the two analytical methods, JFP likely targeted genes associated with immune regulation, including COX-2, HSP90AA1, FOS, MMP3 and MAPK11 and pathways, including IL-17,Th17 cell differentiation and TNF signaling pathway. Finally, JFP was validated to regulate the mRNA expression of FOS, FOSB, FOSL1, MMP3, MMP13 and COX-2 and decrease the release of IL-17A and the protein expression of IL-6 and suppress the phosphorylation of MEK1/2 and ERK1/2 in CTX induced POI rats. CONCLUSION: Jinfeng Pill is effective to ameliorate the symptoms of POI induced by CTX in the model of rats and its action is likely associated with suppressing IL-17A/IL-6 axis and the activity of MEK1/2-ERK1/2 signaling.

Nomegestrol acetate ameliorated adipose atrophy in a rat model of cisplatin­induced cachexia.

Cachexia, a complex disorder that results in depletion of adipose tissue and skeletal muscle, is driven by anorexia, metabolic abnormalities and inflammation. There are limited therapeutic options for this syndrome. Previous evidence has demonstrated that increasing adipose tissue may improve quality of life and survival outcomes in cachexia. Cisplatin, as a chemotherapy drug, also causes cachexia during antitumor therapy due to its adverse effects. To establish a rat model of cachexia, the animals were intraperitoneally treated with cisplatin at doses of 1, 2 and 3 mg/kg, and the rats that responded to cisplatin at the optimal dose were used to test the effect of nomegestrol acetate (NOMAc). Rats that were assessed to be sensitive to cisplatin were randomly grouped and intragastrically administered vehicle, 5 or 10 mg/kg megestrol acetate (MA) or 2.5, 5 or 10 mg/kg NOMAc. The body weights and food consumption of the rats were assessed. Serum IL-6 and TNF-α levels were assessed using ELISA. The protein expression levels of adipose triglyceride lipase (ATGL), hormone-sensitive lipase (HSL), peroxisome proliferator activated receptor γ (PPARγ), fatty acid synthase (FASN) and sterol regulatory element-binding protein-1 (SREBP-1) from inguinal white adipose tissue (iWAT) and epididymal white adipose tissue (eWAT) were evaluated using western blotting. The optimal way to establish a chemotherapy-induced rat model of cachexia demonstrated in the present study was to intraperitoneally administer the rats with 2 mg/kg cisplatin for 3 consecutive days. NOMAc (2.5, 5 mg/kg) and MA (10 mg/kg) were able to significantly ameliorate the loss of body weight in the cisplatin-induced cachectic rats. NOMAc significantly reduced the serum levels of TNF-α at 10 mg/kg. Morphologically, iWAT atrophy, with a remarkable reduction in adipocyte volume, was observed in the cisplatin-induced cachectic rats, but the effects were reversed by administering 5, 10 mg/kg NOMAc or 10 mg/kg MA. Furthermore, 2.5 mg/kg NOMAc markedly reduced the protein expression levels of the lipolysis genes HSL and ATGL, and 5 mg/kg NOMAc markedly enhanced the protein expression levels of adipogenesis genes, including FASN, SREBP-1 and PPARγ in iWAT but not in eWAT. NOMAc was demonstrated to improve cachexia at lower doses compared with MA. Overall, NOMAc is likely to be a promising candidate drug for ameliorating cancer cachexia induced by cisplatin.

Thyroid Hormone Receptor ß Knockdown Reduces Suppression of Progestins by Activating the mTOR Pathway in Endometrial Cancer Cells.

Progestin resistance is a major obstacle to conservative therapy in patients with endometrial cancer (EC) and endometrial atypical hyperplasia (EAH). However, the related inducing factor is yet unclear. In this study, thyroid hormone and its receptor α (TRα) and ß (TRß) of patients were assayed. THRB-silenced RL95-2 and KLE EC cells were cultured to investigate the response of progestins. Transcriptomics and Western blotting were performed to investigate the changes in signaling pathways. We found that THRB, rather than THRA, knockdown promoted the viability and motilities of RL95-2 cells but not KLE cells. The suppressive effect of progestins on cell growth and motility significantly decreased in THRB-silenced RL95-2 cells. Multiple proliferation-related signaling pathways were enriched, and the activities of mammalian targets of rapamycin (mTOR)/4e-binding protein 1 (4EBP1)/eukaryotic translation initiation factor 4G (eIF4G) rather than phosphorylated protein kinase B (Akt) were remarkably boosted. Progestin treatment enhanced the effects, and the augmentation was partially abated on supplementation with T3. In THRB-knockdown KLE cells, the progestins-activated partial signaling pathway expression (either mTOR or eIF4G), and supplementation with T3 did not induce noticeable alterations. The serum levels of triiodothyronine (T3) were significantly lower in patients with EC compared with healthy women. A strong expression of TRß was observed in most patients with EC and EAH sensitive to progestin treatment. In contrast, TRα positive expression was detected in less than half of the patients sensitive to progestin therapy. In conclusion, THRB knockdown enhanced the viability and motility of type I EC cells and attenuated the suppressive effects of progestins by activating the mTOR-4EBP1/eIF4G pathway. Lower expression of THRB is likely correlated with progesterone resistance.

Preparation of mesoporous batatas biochar via soft-template method for high efficiency removal of tetracycline.

In this contribution, we apply a soft-template-assisted hydrothermal route using polyethylene-polypropylene glycol (F127) as soft-template agent and biomass batatas as carbon precursor to synthesis a novel hydrothermal mesoporous biochar (HMC-800) for adsorptive removal of tetracycline (TC) from wastewater. We use the biochar prepared without F127 and direct pyrolytic biochar for comparison. The physicochemical properties of all the studied biochar samples are measured using a suite of characterization techniques. Our results show that the HMC-800 displays the highest specific surface area (286.3 m2/g) and total pore volume (0.249 cm3/g), manifesting the introduction of F127 can result in formation of well-developed pore structures. Regarding adsorption properties, the HMC-800 outperforms other biochar samples for TC removal. Our finding shows that solution with near-neutral pH is favorable for TC removal, and the highest adsorption capacity is observed at initial solution pH value 7. In addition, our findings show that applying the pseudo-second-order kinetic and Freundlich isotherm equation closely models the recorded adsorption behavior. The maximum adsorption capacity is measured to be as much as 238.7 mg/g by Langmuir isotherm model. Pore filling, hydrogen-bonding and n-π interaction are suggested to be the prevailing adsorption mechanisms compared to the other mechanisms. Furthermore, the HMC-800 performs better in regeneration and reuse experiments, making it a promising adsorbent material for TC removal from wastewater.

Metformin Enhances Nomegestrol Acetate Suppressing Growth of Endometrial Cancer Cells and May Correlate to Downregulating mTOR Activity In Vitro and In Vivo.

This study investigated the effect of a novel progestin and its combination with metformin on the growth of endometrial cancer (EC) cells. Inhibitory effects of four progestins, including nomegestrol acetate (NOMAC), medroxyprogesterone acetate, levonorgestrel, and cyproterone acetate, were evaluated in RL95-2, HEC-1A, and KLE cells using cell counting kit-8 assay. Flow cytometry was performed to detect cell cycle and apoptosis. The activity of Akt (protein kinase B), mTOR (mammalian target of rapamycin) and its downstream substrates 4EBP1 (4E-binding protein 1) and eIF4G (Eukaryotic translation initiation factor 4G) were assayed by Western blotting. Nude mice were used to assess antitumor effects in vivo. NOMAC inhibited the growth of RL95-2 and HEC-1A cells, accompanied by arresting the cell cycle at G0/G1 phase, inducing apoptosis, and markedly down-regulating the level of phosphorylated mTOR/4EBP1/eIF4G in both cell lines (p < 0.05). Metformin significantly increased the inhibitory effect of and apoptosis induced by NOMAC and strengthened the depressive effect of NOMAC on activity of mTOR and its downstream substrates, compared to their treatment alone (p < 0.05). In xenograft tumor tissues, metformin (100 mg/kg) enhanced the suppressive effect of NOMAC (100 mg/kg) on mTOR signaling and increased the average concentration of NOMAC by nearly 1.6 times compared to NOMAC treatment alone. Taken together, NOMAC suppressing the growth of EC cells likely correlates to down-regulating the activity of the mTOR pathway and metformin could strengthen this effect. Our findings open a new window for the selection of progestins in hormone therapy of EC.

Global mapping of binding sites for phic31 integrase in transgenic maden-darby bovine kidney cells using ChIP-seq.

BACKGROUND: ΦC31 integrase, a site-specific recombinase, can efficiently target attB-bearing transgenes to endogenous pseudo attP sites within mammalian genomes. The sequence features of endogenous binding sites will help us to fully understand the site-specific recognition function by ΦC31 integrase. The present study was aimed to uncover the global map of ΦC31 integrase binding sites in bovine cells and analysis the features of these binding sites by comprehensive bioinformatics methods. RESULTS: In this study, we constructed a ChIP-seq method that can be used to uncover the global binding sites by phiC31 integrase. 6740 potential ΦC31 integrase binding sites were identified. A sequence motif was found that contains inverted repeats and has similarities to wild-type attP site. Using REPEATMASKER, we identified a total of 20,183 repeat-regions distributed in 50 repeat types for the 6740 binding sites. These sites enriched in "regulation of GTPase activity" of in the GO category of biological process and KEGG pathway of signal transmembrane transporter activity. CONCLUSION: This study is the first time to uncover the global map of binding sites for ΦC31 integrase using ChIP-sequencing method and analysis the features of these binding sites. This method will help us to fully understand the mechanism of the site-specific integration function by phiC31 integrase and will potentially boost its genetic manipulations in both gene therapy and generation of transgenic animals.

Hormone-like activities of Kuntai capsule in the uteri of ovariectomized rats and immature rabbits.

OBJECTIVE: To investigate the hormone-like activities of Kuntai capsule (KTC) in the uteri of ovariectomized rats and immature rabbits. METHODS: Following bilateral ovariectomy, rats were randomly divided into six groups including sham group, control group, estradiol valerate group, KTC 0.24, 0.6, and 1.5 g/kg groups. The rats were treated with 0.5% CMC-Na, estradiol valerate and KTC (0.24, 0.6, and 1.5 g/kg), respectively for 28 consecutive days. Then the estrous cycle, uterine changes and pathological changes were examined. Serum levels of estradiol (E2), and progesterone (P4) were measured by enzyme-linked immunosorbent assay (ELISA). Protein levels of estradiol receptor (ER), progesterone receptor (PR), vascular endothelial growth factor (VEGF), proliferating cell nuclear antigen (PCNA) and nuclear-associated antigen-67 (Ki-67) in uterine tissues were detected by western blot. Immature rabbits were estrogen-primed prior to intragastric administration with KTC for 6 d consecutively. Then, the uteri underwent hematoxylin-eosin staining to observe endometrial transformation. RESULTS: Compared with the control group, 0.6 and 1.5 g/kg KTC markedly decreased the uterine organ coefficient and endometrial thickness (P < 0.05). The serum level of P4 was increased in the KTC 0.6 g/kg group (P < 0.05). There were no significant variations in the serum level of E2 in the KTC groups compared with the control group. ER¦Â, but not ER¦Á, was markedly upregulated after KTC administration (P < 0.05). Furthermore, 1.5 g/kg KTC significantly decreased the protein level of PRA (P < 0.05) and 0.6 g/kg KTC increased the protein level of PRB in the uteri (P < 0.05). VEGF was highly expressed after treatment with 0.24 and 0.6 g/kg KTC, and Ki-67 was markedly reduced in ovariectomized rats treated with 1.5 g/kg KTC. No difference was found in the expression of PCNA. KTC 0.24 and 0.6 g/kg promoted endometrial transformation in immature rabbit uteri. CONCLUSION: KTC does not demonstrate obvious estrogen-like effect on uteri after ovariectomy, but it does exhibit weak progestogen-like effect, by which mechanism of action is yet to be further investigated.

Podophyllotoxin Extracted from Juniperus sabina Fruit Inhibits Rat Sperm Maturation and Fertility by Promoting Epididymal Epithelial Cell Apoptosis.

This study aimed to investigate the antifertility effect of Juniperus sabina fruit on male rats and its possible mechanism, and hence it might be developed as a potential nonhormonal male contraceptive. Male rats were intragastrically fed for consecutive 8-week and 4-week recovery with the fruit of J. Sabina, and sperm maturation, serum testosterone level, and histopathology were analyzed. Epididymal epithelial cell culture was prepared for detection of podophyllotoxin activities. Furthermore, cell proliferation, transmission electron microscopy, Annexin V/Propidium iodide, TUNEL, RT-PCR, ELISA, and western blotting were examined. The results showed that rat sperm motility and fertility were remarkably declined after feeding the fruit. Moreover, the fruit targeted the epididymis rather than the testis. After 4-week recovery, more than half of the male rats resumed normal fertility. It was found that podophyllotoxin significantly inhibited epididymal epithelial cell proliferation, promoted cell apoptosis, and increased the mRNA and protein levels of TNF-α and the expression levels of cytochrome c, caspase-8, caspase-9, and caspase-3. Our findings suggest that the fruit of J. sabina could inhibit male rat sperm maturation and fertility. The potential mechanism might be related to podophyllotoxin, inducing epididymal epithelial cell apoptosis through TNF-α and caspase signaling pathway.

Preparation of La-modified magnetic composite for enhanced adsorptive removal of tetracycline.

Composite adsorbents usually outperform single component adsorbents as they could combine the properties and advantages of each component. In this research, rare earth element Lanthanum was introduced into magnetic substrate by a method of chemical co-precipitation to enhance its adsorption capability. It was found that the La-modified magnetic composite with a presumed La and Fe3O4 molar ratio at 1:50 had a better adsorption performance for tetracycline than the magnetic adsorbents at other molar ratios. The La-modified magnetic composite was characterized by scanning electron microscope, X-ray diffractometer, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The results showed that the magnetic adsorbent was nano-sized, and the introduction of La did not change the crystal structure of magnetic substrate. The adsorptive removal of tetracycline was favorable at neutral pH conditions. Kinetic experiments indicated that most of the uptake occurred within the initial 120 min. Chemisorption occurred in the process while rate-determining step might be diffusive in nature. An empirical model (Langmuir model) was applied in this paper, and fitting result indicates that the q max value of the magnetic composite reached as much as 145.9 mg/g for the uptake of tetracycline at 298 K. The above indicates that method of La doping could significantly enhance the adsorption capability of an intentionally designed composite adsorbent.

Kuntai Capsule Inhibited Endometriosis via Inducing Apoptosis in a Rat Model.

We evaluated the effectiveness of Kuntai Capsule (KTC) for treating endometriosis using rat model and investigated its preliminary mechanism of action involved. SD rats were implanted with endometrial tissues and treated with KTC for three weeks. Then, laparotomy was performed to examine volume changes of the autografts. The serum levels of TNF-α, IL-6, COX-2, E2, and P4 were measured through ELISA. TUNEL was performed to analyze the apoptosis on ectopic endometrium. Protein levels of caspases 8, 9, and 3 and cytochrome c in the ectopic and eutopic endometrium were measured by western blotting. Results showed that KTC significantly decreased the volumes of ectopic endometrium. The level of TNF-α increased and E2 decreased in the KTC treatment groups. TUNEL and western blot assay showed that KTC could induce apoptosis of endometriotic tissues, accompanied with the increased protein expression of caspases 8 and 9, activated caspase-3, and cytochrome c in a dose-dependent manner. However, these protein expression profiles were not affected in eutopic endometrium. Our findings suggest that KTC could inhibit the growth of ectopic endometrial tissue through upregulating the level of TNF-α and its downstream signaling, including caspases and cytochrome c.

Identification of New Epididymal Luminal Fluid Proteins Involved in Sperm Maturation in Infertile Rats Treated by Dutasteride Using iTRAQ.

BACKGROUND: Spermatozoa become mature and acquire fertilizing capacity during their passage through the epididymal lumen. In this study, we identified new epididymal luminal fluid proteins involved in sperm maturation in infertile rats by dutasteride, a dual 5α-reductase inhibitor, in order to provide potential epididymal targets for new contraceptives and infertility treatment. METHODS: Male rats were treated with dutasteride for 28 consecutive days. We observed the protein expression profiles in the epididymal luminal fluids in infertile and normal rats using isobaric tags for relative and absolute quantitation (iTRAQ) technique. The confidence of proteome data was validated by enzyme-linked immunosorbent assays. RESULTS: 1045 proteins were tested, and 23 of them presented different expression profiling in the infertile and normal rats. The seven proteins were down-regulated, and 16 proteins were up-regulated. Among the seven proteins which were significantly down-regulated by dutasteride in the epididymal luminal fluids, there were three ß-defensins (Defb2, Defb18 and Defb39), which maybe the key proteins involved in epididymal sperm maturation and male fertility. CONCLUSIONS: We report for the first time that dutasteride influences the protein expression profiling in the epididymal luminal fluids of rats, and this result provides some new epididymal targets for male contraception and infertility therapy.

Effect of a magnetic field on the adsorptive removal of methylene blue onto wheat straw biochar.

Biochar pyrolyzed from wheat straw was innovatively used for the adsorptive removal of cationic dye methylene blue through exposure to a magnetic field. The adsorption capability of the biochar pyrolyzed at 200 °C exceeded that of samples pyrolyzed at higher temperatures. The surface acidic functional groups of wheat straw biochar were deduced to be more sensitive to the effects of the external magnetic field. The enhancement of the magnetic field achieved by increases in the initial dye concentration, and a decrease in the biochar dosage and solution pH, were more significant compared with those caused by other conditions. Kinetic experiments indicated that chemisorption occurred during adsorption. The qmax values for dye adsorption without, and with, an external magnetic field were found to be 46.6 and 62.5mg/g, respectively. These demonstrated that wheat straw biochar could be used for the efficient adsorption of pollutants when assisted by an external magnetic field.

[Inhibitory effect of dutasteride on the expressions of epididymal Claudin1 and ß-catenin in male rats].

OBJECTIVE: To explore the molecular mechanism of dutasteride inhibiting fertility by studying its effects on the expressions of the epididymal epithelial junction proteins Claudin1 and ß-catenin in rats. METHODS: Sixteen 3-month-old SD male rats were equally divided into an experimental and a negative control group to be treated intragastrically with dutasteride at 40 mg/kg per day and the same dose of solvent, respectively, for 14 consecutive days. Then, the sperm motility and morphology of the rats were detected by computer-assisted sperm analysis, the serum levels of testosterone (T) and dihydrotestosterone (DHT) measured by ELISA, changes in the tight junction of epididymal cells observed under the transmission electron microscope, the protein and gene expressions of Claudin1 and ß-catenin determined by RT-PCR and immunohistochemistry, and the conception rate of the mated female rats calculated. RESULTS: Dutasteride significantly suppressed the serum DHT level, sperm motility, and fertility of the rats (P <0.05). Interspaces between epididymal epithelial cell tight junctions were observed, the volume of epididymal fluid obviously increased, and the expressions of Claudin1 and ß-catenin gene and protein remarkably downregulated in the experimental rats (P <0.05). CONCLUSION: Dutasteride can significantly inhibit the fertility of male rats by reducing the serum DHT level, suppressing Claudin1 and ß-catenin expressions, and damaging epididymal epithelial cell junctions.

Mechanism of enhanced removal of quinonic intermediates during electrochemical oxidation of Orange II under ultraviolet irradiation.

The effect of ultraviolet irradiation on generation of radicals and formation of intermediates was investigated in electrochemical oxidation of the azo-dye Orange II using a TiO2-modified ß-PbO2 electrode. It was found that a characteristic absorbance of quinonic compounds at 255 nm, which is responsible for the rate-determining step during aromatics degradation, was formed only in electrocatalytic oxidation. The dye can be oxidized by either HO radicals or direct electron transfer. Quinonic compounds were produced concurrently. The removal of TOC by photo-assisted electrocatalytic oxidation was 1.56 times that of the sum of the other two processes, indicating a significant synergetic effect. In addition, once the ultraviolet irradiation was introduced into the process of electrocatalytic oxidation, the degradation rate of quinonic compounds was enhanced by as much as a factor of two. The more efficient generation of HO radicals resulted from the introduction of ultraviolet irradiation in electrocatalytic oxidation led to the significant synergetic effect as well as the inhibiting effect on the accumulation of quinonic compounds.

The purine-carboxylate-containing coordination polymer poly[[µ4-1-(2-carboxylatoethyl)-6-oxo-6,9-dihydro-1H-purin-9-ido]zinc(II)].

The title compound, [Zn(C8H6N4O3)]n or [Zn(L)]n [H2L is 3-(6-oxo-6,9-dihydro-1H-purin-1-yl)propionic acid], crystallized as a nonmerohedral twin. The Zn(II) cation is four-coordinated, ligated by two carboxylate O atoms from two L ligands and two N atoms from another two ligands. Each ligand bridges four Zn(II) centres, extending the structure into a three-dimensional polymer with a 4-connected (6(5),4(1)) topological structure containing two-dimensional homochiral layers constructed from one-dimensional metal-organic helices. Investigation of the thermal stability of the compound shows that the network has very high thermostability and is stable up to 720 K.

Poly[bis[µ2-3-(pyridin-4-yl)benzoato-κ³N:O,O']lead(II)].

In the title compound, [Pb(C12H8NO2)2]n, the Pb atom sits on a crystallographic C2 axis and is six-coordinate, ligated by two chelating carboxylate groups from two 3-(pyridin-4-yl)benzoate (L) ligands and by two N atoms from another two ligands. Each ligand bridges two PbII centres, extending the structure into a corrugated two-dimensional (4,4) net. The ligand L is conformationally chiral, with a torsion angle of 27.9 (12)° between the planes of its two rings. The torsion angle has the same sense throughout the structure, so that the extended two-dimensional polymer is homochiral. Investigation of the thermal stability shows that the network is stable up to 613 K. In the absence of any stereoselective factor in the preparation of the compound, the enantiomeric purity of the crystal studied, based only on the torsional conformation of the ligand, implies that the bulk sample is a racemic conglomerate.

catena-Poly[[[diaquazinc]-bis{µ-N2,N6-bis[(pyridin-3-yl)methyl]pyridine-2,6-dicarboxamide}] dinitrate].

In the title compound, {[Zn(C(19)H(17)N(5)O(2))(2)(H(2)O)(2)](NO(3))(2)}(n), the Zn(II) cation is located at an inversion centre within a slightly distorted octahedron, ligated by four N atoms from four N(2),N(6)-bis[(pyridin-3-yl)methyl]pyridine-2,6-dicarboxamide (L) ligands occupying a plane about the Zn(II) atom with the two water O atoms perpendicular to that. In the complex molecule, the bidentate bridging L ligands display helical R and S conformers, and link the Zn(II) cations into a one-dimensional centrosymmetric double-chain structure containing 32-membered rings. The nitrate anions reside in these rings and are involved in multiple N-H...O hydrogen-bond interactions. On excitation at 390 nm, the title compound displays a strong blue emission centred at 449 nm. Investigation of the thermal stability shows that the network structure is stable up to 420 K.

Poly[[bis{µ2-N2,N6-bis[(pyridin-3-yl)methyl]pyridine-2,6-dicarboxamide}dichloridonickel(II)] N,N-dimethylformamide tetrasolvate].

In the title compound, {[NiCl(2)(C(19)H(17)N(5)O(2))(2)]·4C(3)H(7)NO}(n), the Ni(II) atom is located on an inversion centre and is in a six-coordinated octahedral geometry, formed by four pyridine N atoms from four N(2),N(6)-bis[(pyridin-3-yl)methyl]pyridine-2,6-dicarboxamide (BPDA) ligands occupying the equatorial plane and two chloride anions at the axial sites. The bidentate bridging BPDA ligands link the Ni(II) atoms into a two-dimensional corrugated grid-like flexible layer with a (4,4)-connected topology, which consists of left- and right-handed helical chains sharing the common Ni(II) atoms. Investigation of the thermal stability shows that the network is stable up to 573 K.