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Harmful Microcystis blooms (HMBs) and microcystins (MCs) that are produced by  Microcystis seriously threaten water ecosystems and human health. This study demonstrates an eco-friendly strategy for simultaneous removal of MCs and HMBs by adopting unique hyperoxic graphene oxides (HGOs) as carrier and pure microcystinase A (PMlrA) as connecting bridge to form stable HGOs@MlrA composite. After oxidation, HGOs yield inherent structural strain effects for boosting the immobilization of MlrA by material characterization and density functional theory calculations. HGO 5 exhibits higher loading capacities for crude MlrA (1,559 mg·g -1 ) and pure MlrA (1,659 mg·g -1 ). Moreover, the performances of HGO 5 @MlrA composite, including the capability of removing MCs and HMBs, the ecological and human safety compared to MlrA or HGO 5 treatment alone, have been studied. These results indicate that HGO 5 can be used as a promising candidate material to effectively improve the application potential of MlrA in the simultaneous removal of MCs and HMBs., Competing Interests: The authors declare no competing interests., (© 2022 The Author(s).)

Antibiotic residues from animal manure cause soil pollution and can pose a threat to soil animals. In this study, the toxicological effects of fluoroquinolone antibiotics on Enchytraeus crypticus, including defence response, gut microbiome, and antibiotic resistance genes (ARGs), were studied. The cytochrome P450 enzyme activity and reactive oxygen species levels increased, activating the defense response. The superoxide dismutase and glutathione S-transferase activity, and the expression of immune defense molecules such as coelomic cytolytic factor, lysozyme, bactericidal protein fetidins and lysenin changed. Furthermore, the diversity of the gut microbiome decreased, and the relative abundance of Bacteroidetes decreased significantly at the phylum level but increased in pathogenic and antibiotic-secreting bacteria (Rhodococcus and Streptomyces) at the genus level. However, the soil microbiome was not significantly different from that of the control group. The relative abundance of ARGs in the gut and soil microbiome significantly increased with enrofloxacin concentration, and the fluoroquinolone ARGs were significantly increased in both the soil (20.85-fold, p < 0.001) and gut (11.72-fold, p < 0.001) microbiomes. Subtypes of ARGs showed a positive correlation with Rhodococcus, which might increase the risk of disease transmission and the probability of drug-resistant pathogens. Furthermore, mobile genetic elements significantly promote the spread of ARGs., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Objectives: To analyze the chromatic properties and translucency of porcelain veneers made from different ceramic materials against the background of tetracycline-stained teeth., Methods: Porcelain specimens (A1, A3, B2, B4) measuring 0.50 mm in thickness were prepared by heat-press casting and layering. The L*, a*, and b* values of the specimens against simulated tetracycline tooth and black-and-white backgrounds were measured by a spectrophotometer, and color differences ΔE 00 1 between specimens on simulated tetracycline backgrounds and the backgrounds themselves and ΔE 00 2 between specimens on simulated tetracycline backgrounds and the white background were calculated. The translucent parameter (TP) was also evaluated., Results: The ΔE 00 1 of feldspathic specimens (IPS d.SIGN) with the opaque layer was significantly greater than that of glass ceramic specimens (IPS e.max Press LT), and the ΔE 00 1 of group B4 was consistently greater than those of the other color groups ( P <0.05). The ΔE 00 2 values of all feldspathic specimens with the opaque layer were less than 1.25, and the ΔE 00 2 values of the glass ceramic specimens were greater than 2.23. However, no significant difference was observed among the different color groups ( P >0.05). The TP values of feldspathic specimens with the opaque layer were significantly lower than those of glass ceramic specimens( P <0.05), but no significant difference was observed among different color groups ( P >0.05)., Conclusions: When changing the color of tetracycline-stained teeth, 0.50 mm-thick IPS d.SIGN feldspathic veneers with an opaque layer provide better chromatic properties than IPS e.max Press LT glass ceramic veneers. However, the translucency of feldspathic veneers is generally poorer than that of glass ceramic veneers.

Purpose: To analyze the effect of porcelain layer thicknesses and substrates on color properties and translucency of IPS e.max LT porcelain laminate veneers used to restore tetracycline stained teeth., Methods: Porcelain specimens with different core and veneer thickness (veneer/core thickness: 0.25 mm/0.25 mm, 0.50 mm/0.25 mm, 0.25 mm/0.50 mm, 0.50 mm/0.50 mm, and 0.25 mm/0.75 mm) were fabricated by heat-press layering technique. CIE L * a * b * parameters were measured under simulated tetracycline backgrounds and black and white backgrounds by a spectrophotometer, color differences ΔE 00 1 between specimens on simulated tetracycline backgrounds and backgrounds themselves and ΔE 00 2 between specimens on simulated tetracycline backgrounds and white background were calculated. The translucent parameter(TP) was also calculated. The data were submitted to statistical analysis with SPSS 17.0 software package., Results: ΔE 00 1 increased with increase of thickness of the core and veneer layer, but there was no significant difference between 0.25 mm and 0.50 mm core thickness groups with 0.50 mm veneer in thickness (P>0.01). Except for light grey, ΔE 00 2 decreased over other substrates with increase of thickness of the core and veneer layer, but there was no significant difference between 0.50 mm and 0.75 mm core thickness groups with 0.25 mm veneer in thickness (P>0.01). Both ΔE 00 1 and ΔE 00 2 were significantly different over different substrates（P<0.01）. TP decreased as the increase of core and veneer thickness and TP was significantly different with different core and veneer thickness（P<0.01）., Conclusions: Both the core/veneer thickness and the substrate have significant influence on color matching and masking ability of IPS e.max LT porcelain laminate veneers used to restore tetracycline stained teeth. As for IPS e.max LT porcelain veneers, the color property was the best when yellowish tetracycline stained teeth were restored, while the light grey was worst. The thickness of core and veneer has significant influence on the translucency of porcelain laminate veneers.

The effects of frying temperature and time on the amylose content, thermodynamic properties, crystalline properties, and pasting properties of starch in wheat-flour based noodles were investigated. The amylose content increased when the frying temperature increased or the frying time extended. Differential scanning calorimetry confirmed the formation of starch-lipid complexes. ΔH of the complexes increased sharply from 0.91 to 1.40 J/g with increased frying temperature, while it initially increased from 1.01 to 1.40 J/g and then decreased rapidly to 1.17 J/g with prolonged frying time. These observations were consistent with the results of relative crystallinity. Rapid viscosity analysis showed that the viscosities decreased by the increasing frying temperature or the prolonging frying time. The results showed that the deep-frying process destroyed the starch structure and led to the formation of starch-lipid complexes., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

A new visible light-mediated photocatalytic decarboxylative oxyphosphorylation of cinnamic acids with diarylphosphine oxides is described. This reaction is performed under mild conditions to afford the corresponding β-ketophosphine oxides.

Objective To investigate the value of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) permeability parameters in monitoring the early response to bevacizumab plus chemotherapy in colorectal cancer patients with liver metastases. Methods Magnetic resonance examinations including plain and DCE-MRI were performed in 28 colorectal cancer patients with liver metastases. The permeability parameters including the volume transfer constant (K trans ),extravascular extracellular volume fraction (V e ),reverse volume transfer constant (K ep ),and percentage of plasma volume (V p ) were measured before chemotherapy and at the first chemotherapy cycle. All the target lesions were grouped into the hypersensitivity and hyposensitivity groups,and t test was used to calculate the statistical significance between these two groups. The receiver operating characteristic (ROC) curve analysis was also performed for evaluating the diagnostic efficacy in monitoring the early response to chemotherapy. Results Totally 64 target lesions,including 29 lesions in the hypersensitivity group and 35 lesions in the hyposensitivity group,were confirmed. The K trans 0 and K ep0 values of the hypersensitivity group were significantly higher than those of the hyposensitivity group before chemotherapy (P=0.040,P=0.049),whereas the V e0 and V p0 values showed no significant change between these two groups (P>0.05). When the K trans 0 value was 1.129 min -1 ,the area under curve was 0.726,the sensitivity was 65.5%,and the specificity was 71.4%. Conclusion The DCE-MRI permeability parameters is useful for monitoring the early response to chemotherapy,and the K trans value can be a quantitative indicator to predict early response.

Objective: To investigate imaging manifestation and clinical application of MRI on malignant fibrous histiocytoma (MFH) in soft tissue., Methods: Imaging and pathological data of 16 patients with malignant fibrous histiocytoma (MFH) in soft tissue confirmed by surgery and pathology were retrospectively analyzed from January 2009 to August 2016. There were 9 males and 7 females, aged from 34 to 67 years old with an average of 52 years. The courses of disease ranged from 5 to 48 months with an average of 27 months.The main clinical manifestations were soft tissue mass and local pain. All patients were underwent plain and enhanced MRI before operation. Pathogenic sites, MRI manifestation and pathology results were observed after operation., Results: MRI in 16 cases of T1WI showde slightly lower signal or equal signals, of which 6 cases of tumor see mixed signal; in T2WI were high signal, of which 7 cases of internal tumor can be seen low signal separation, 5 cases of turor can be seen flase envelope, 11 cases of tumor with the surrounding boundaries unclear with edema. All lesions showed significantly uneven enhancement. Immunohistochemical examination showed that Vim, CD68 was positive., Conclusions: Although MRI features of MFH has certain characteristics, the qualitative was more difficult, and ultimately need to determine the pathological and immunohistochemical. But MRI examination has obvious advantages in clarifying range of tumor, invading peripheral blood vessels and nerves, and has important clinical application value for clinical operation plan and postoperative tumor residual and recurrence, and provid reference for clinical curative effect., Competing Interests: The authors of this article and the planning committee members and staff have no relevant financial relationships with commercial interests to disclose.

Vaccinium bracteatum Thunb.(VBT) is a traditional Chinese herb that recorded has an effect of hypoglycemic. We previous discovered a dose-dependent anti-diabetic function of VBT. leaves' polysaccharide (VBTLP), but little is known about its underlying molecular mechanism. Therefore, we hypothesized that VBTLP would decrease hepatic gluconeogenesis to improve glucose metabolism in mice. To test this hypothesis, glucose tolerance test was performed to evaluate the effect of VBTLP on mice hepatic gluconeogenesis. Western blot and RT-PCR were performed to measure both in vivo and in vitro gene regulation under VBTLP treatment. Online bioinformatic analysis was performed to discover a target candidate, miR-137 of LKB1 and AMPK under VBTLP treatment, and the luciferase assay was conducted to validate it. Here we found that VBT. leaves' polysaccharide (VBTLP) decreased hepatic gluconeogenesis via activation of LKB1/AMPK axis in vivo and in vitro. Mechanistic studies reveal that miR-137 regulates hepatic glucose homeostasis by directly targeting AMPK and LKB1. Furthermore, we shown that VBTLP decreased hepatic miR-137 level, which might contribute to activation of LKB1/AMPK and downregulation of gluconeogenesis. Taken together, our study shown that the mechanisms might involve in VBTLP hypoglycemic effect, alleviates hepatic gluconeogenesis via the downregulation of miR-137. Our findings provide guidance in developing novel, safe and effective therapies for T2DM., (Copyright © 2017. Published by Elsevier Masson SAS.)

Unlabelled: OBJECTIVE To investigate the diagnostic value of combining permeability with T1 perfusion parameters in quantitative dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in glioma grading., Methods: Magnetic resonance imaging was performed in 16 patients with high grade gliomas (HGG) and 12 patients with low grade gliomas(LGG) confirmed by pathology. The permeability was quantitatively analyzed and the T1 perfusion parameters of the tumor were calculated by the pharmacokinetic model,including volume transfer constant (K(trans)),volume fraction of extravascular extracellular space (ve),reflux constant (kep),fractional plasma volume (vp),cerebral blood flow (CBF),cerebral blood volume (CBV),and mean transit time (MTT). A t-test was used to calculate the statistical significance of quantitative analysis parameters between HGG and LGG. The receiver operating characteristic curve analysis was also performed for evaluating the sensitivity,specificity,and area under curve (AUC) of the permeability parameters and perfusion parameters and the combination of these parameters., Results: The differences of the K(trans),ve,CBF,and CBV values [(0.276<0.164)/min vs. (0.084<0.044)/min;0.486<0.191 vs. 0.274<0.132;(1.755<1.164)ml/(g·min) vs. (0.761<0.625) ml/(g·min);(0.204<0.101) ml/g vs. (0.115<0.097)ml/g] were statistically significant (t=3.934,3.293,2.672,2.338,P<0.05) between HGG and LGG. The differences of the kep,vp, and MTT value [(1.632<1.204)/min vs. (1.537<1.194)/min;0.114<0.107 vs. 0.055<0.039;(0.128<0.070)min vs. (0.145<0.066)min] were not statistically significant (t=0.208,1.823,0.688,P>0.05). When the K(trans) value was 0.105/min,the AUC was the largest (0.919) by the single parameter in glioma grading,and meanwhile the sensitivity and specificity were 87.5% and 83.3%,respectively. When the ve-CBF value was 0.631,the AUC was the largest (0.974) by the multiple parameter,and meanwhile the sensitivity and specificity were 93.7% and 100.0%,respectively., Conclusion: Combining permeability with perfusion parameters in quantitative DCE-MRI can improve the accuracy of the glioma grading.

A combinational study of structural chemistry and dyestuff chemistry has been carried out to reveal the structure-performance relationship for eight disperse azo dyes by comparing their structures, electronic spectra, solvatochromism and theoretic computations. All eight structural analogues have the same 4-nitro-4'-amino-azobenzene donor-π-acceptor skeleton but different substituted groups, namely, R1 and R2 in ring A, R3, R4 and R5 in Ring B. X-ray single-crystal diffraction analyses indicate that four azo dyes have severely twisted aminoazobenzene structures because of the steric hindrance of ortho dichloro/dibromo radicals of 4-nitrobenzene moiety, while the other four dyes show essentially planar conformation due to the ortho monosubstituted 4-nitrobenzene amine and 4'-amino-azobenzene units. It is noted that the electronic spectra are closely related to their molecular structures, where the presence of different auxochrome groups and the spatial crowding effects in the aminoazobenzene backbone lead to significant alterations of the bathochromic and hypsochromic shifts., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Background: Heat-induced protein aggregation is important for the texture of various food products. Many types of food proteins have been found to assemble into fibrillar structures under certain conditions. We studied fibril formation of cottonseed 7S storage protein upon heating (for 0-720 min) at 90°C and pH 2.0, investigated the conversion rate, and determined the extent of thermal aggregation., Results: Thioflavin-T fluorescence and Congo-red analysis indicated the formation of amyloid-like fibrils upon heating. Centrifugal filtration indicated that the conversion was very low (<10%) until congossypin concentration up to 2 mg mL(-1), and the conversion increases with increasing heating time, but levels off after longer heating times. Dynamic light scattering and atomic force microscopy showed that the extent of thermal aggregation at pH 2.0, or contour length of the worm-like and fine-stranded aggregates, progressively increased with increasing heating time. Furthermore, reducing electrophoresis analyses indicated that progressive polypeptide hydrolysis occurred upon heating. Experiments indicate that congossypin can form heat-induced amyloid-like aggregates and the conversion of congossypin monomers into fibrils increased with heating time and protein concentration., Conclusion: The results would be of vital importance for the utilisation of cottonseed proteins to produce thermally induced fibrillar gels with excellent properties., (© 2013 Society of Chemical Industry.)

Objective: To compare the value of liver acquisition with volume acceleration (LAVA) and magnetic resonance cholangiopancreatography (MRCP) in diagnosing benign and malignant intraductal papillary mucinous neoplasms (IPMN) of the pancreas., Methods: The MR findings of 35 IPMN patients confirmed by pathology were analyzed retrospectively, and the sequences included T1WI, T2WI, LAVA, and MRCP. All patients were divided into two groups: the group of MRI enhancement (including T1WI, T2WI, and MRI enhancement) and the group of MRCP (including T1WI, T2WI, and MRCP). Two groups were evaluated by the receiver operating characteristic (ROC) curve., Results: Totally 23 cases of intraductal papillary mucinous tumors and 12 cases of intraductal papillary mucinous carcinomas were diagnosed. Finally, 29 cases (29/35) of IPMN were diagnosed correctly in the group of MR enhancement, and 25 cases (25/35) diagnosed correctly in the group of MRCP. The differential diagnostic accuracy of the group of MRI enhancement (82.9%) was higher than that of the group of MRCP (71.4%), although the difference was not statistically significant (P=0.068). The sensitivity, specificity, positive predictive value, and the area under the ROC curve (AUC) of the group of MRI enhancement were 83.3%, 82.6%, 71.4%, and 0.850, and those of the group of MRCP were 75.0%, 69.6%, 52.3%, and 0.723. The AUC of the group of MRI enhancement was significantly larger than that of the group of MRCP (P=0.0465)., Conclusion: MRI enhancement is more valuable than MRCP in the differential diagnosis of benign and malignant IPMN.

Two pairs of 1: 2 neutral trans mononuclear transition-metal (M = Ni(II) and Cu(II)) complexes of pyridine-2,4-dione and quinoline-2,4-dione based heterocyclic dyes have been structurally and spectrally characterized and compared herein. X-ray single-crystal diffraction analyses of four complexes, namely trans-[Ni(La)2(DMF)2] (1), trans-[Cu(La)2(DMF)2] (2), trans-[Ni(Lb)2(DMF)2] (3) and trans-[Cu(Lb)2(DMF)2] (4), reveal that they have the same trans configuration between the bidentate chelating dianionic ligands and two axially coordinated DMF molecules. Furthermore, a transformation from the hydrazone to azo configuration has been observed for both bidentate chelating ligands La(-) and Lb(-) after metal-ion complexation. More importantly, the simultaneous DSC/TG-MS-FTIR method has been used to explore the thermal stability of four neutral metal-complex dyes 1-4, where the two axially coordinated DMF molecules in Ni(II) and Cu(II) complexes exhibit distinguishable decomposition behavior because of their different M-O bond lengths originating from the Jahn-Teller distortions.

Objective: To compare the roles of Gd-EOB-DTPA-enhanced magnetic resonance imaging (MRI) using the liver acquisition with volume acceleration(LAVA) sequence and diffusion-weighted imaging(DWI) in the detection of hepatic metastases sized ≤3 cm., Methods: We retrospectively analyzed the MRI data of 16 patients with hepatic metastases. All the sequences used included T1WI, T2WI,3D-LAVA, and DWI (b value=500 s/mm(2)). All patients were divided into two groups based on the sequences: group A (T1WI, T2WI, and 3D-LAVA enhanced MR) and group B(T1WI,T2WI and DWI). The hepatic metastases were evaluated by analyzing the receiver operating characteristic (ROC) curves., Results: A total of 39 hepatic metastatic lesions were identified. The sensitivity, specificity, Youden index and the area under the ROC curve (AUC) were 97.4%, 88.2%, 0.856, and 0.944 in group A and 82.1%, 91.2%, 0.733, and 0.834 in group B. The ROC curves (p=0.040) and Youden index(p=0.043) in group A were significantly larger than in group B., Conclusion: Gadolinium-EOB-DTPA-enhanced MRI has higher accuracy than DWI in the detection of small metastases.

The azo-hydrazone tautomerism of two pyridine-2,6-dione based Disperse Yellow dyes has been achieved by pH control and metal-ion complexation, respectively, which is evidenced by UV-visible spectra using pH-titration, (1)H NMR and X-ray single-crystal diffraction techniques for two dyes and one neutral dinuclear dye-metal complex. pH-titration experiments under strong and weak acidic conditions (HCl and HOAc) as well as strong and weak alkaline conditions (NaOH and ammonia) demonstrate that there is an equilibrium between the azo (HL(1-A) and HL(2-A)) and hydrazone (HL(1-H) and HL(2-H)) tautomers for two dyes in solution but the hydrazone form is dominant under conventional conditions. The hydrazone proton is also observed in the (1)H NMR spectra of HL(1-H) and HL(2-H) which can be verified by the hydrogen-deuterium exchange and the presence of cooperative six-membered intramolecular hydrogen rings involving the hydrazone proton in their X-ray single-crystal structures. Moreover, the azo-hydrazone tautomerism is evidenced by the formation of a novel neutral dinuclear dye-metal complex Cu(2)(L(2-A))(4), where all the ligands are in the azo form and two types of coordination modes are present for four L(2-A) ligands. Namely, the side two ligands serve as the bidentate capping ligands, while the middle ones act as the quadridentate bridging ligands linking adjacent Cu(II) centers in a reverse fashion.

In the title compound, C(18)H(24)N(2) (2+)·2Cl(-)·H(2)O, both the cation and the water mol-ecule lie on a twofold crystallographic axis. In the cation, the two benzene rings are perpendicular to each other, making a symmetry-constrained dihedral angle of 90°. In the crystal, N-H⋯Cl, O-H⋯Cl and N-H⋯O hydrogen bonds result in the formation of a three-dimensional network.

In the title molecular salt, C(7)H(6)N(3)O(2)S(+)·HSO(4) (-), the 2-amino-6-nitro-1,3-benzothia-zole ring system is essentially planar [mean deviation = 0.0605 (4) Å]. In the crystal, N-H⋯O and O-H⋯O hydrogen-bonding inter-actions result in a layer motif.

In the title compound, C(12)H(12)Cl(2)N(2) (2+)·SO(4) (2-), the two rings are not coplanar [dihedral angle = 48.7 (2)°]. In the crystal, multiple N-H⋯O hydrogen-bond inter-actions are found between the ammonium and sulfate groups.

In the title compound, C(5)H(7)N(2) (+)·N(3) (-)·C(5)H(6)N(2), all N atoms of the azide anion are situated on a twofold rotational axis, so the 4-amino-pyridinium cation and 4-amino-pyridine mol-ecule, being related by symmetry, occupy one position in the asymmetric unit. Inter-molecular N-H⋯N hydrogen bonds generate a three-dimensional hydrogen-bonding network which consolidates the crystal packing.

The title compound, C(12)H(14)N(4), has a crystallographically imposed centre of symmetry. Inter-molecular N-H⋯N hydrogen bonds between amino groups link adjacent mol-ecules into a three-dimensional network where ten-membered hydrogen-bonded rings are observed.

In the title compound, C(4)H(8)N(5) (+)·Cl(-), a two-dimensional layer packing network is observed in which every chloride anion links three adjacent 2,4-diamino-6-methyl-1,3,5-triazin-1-ium cations by N-H⋯Cl hydrogen-bonding inter-actions, forming 12-membered and eight-membered hydrogen-bonded rings with graph-set motifs R(4) (4)(12) and R(3) (3)(8), respectively. In addition, N-H⋯N hydrogen bonds are found between adjacent cations, forming another type of eight-membered [R(2) (2)(8)] hydrogen-bonded ring.

In the title compound, C(6)H(8)NO(2) (+)·Cl(-), inter-molecular O-H⋯Cl and N-H⋯Cl hydrogen bonds are observed in which each chloride anion links three adjacent cations into a hydrogen-bond network.

In the title salt, C(4)H(8)N(5) (+)·NO(3) (-), a ring N atom of 2,6-diamino-4-methyl-triazine is protonated. Each anion is connected to three neighbouring cations by multiple N-H⋯O hydrogen bonds which, together with N-H⋯N contacts, generate a layer structure.

The tetra-nuclear copper(II) title complex, [Cu(4)Cl(2)(OH)(4)(C(10)H(8)N(2))(4)](NO(3))(2)·6H(2)O, has a crystallographically imposed centre of symmetry. The metal atoms display a distorted tetragonal-pyramidal coordination geometry, and are linked by two μ(2)- and two μ(3)-hydroxo groups, assuming a chair-like conformation for the Cu(4)O(2) core. In the crystal, the complex mol-ecules are linked into a three-dimensional network by inter-molecular O-H⋯O, O-H⋯Cl, C-H⋯O and C-H⋯Cl hydrogen bonds and π-π stacking inter-actions with centroid-centroid separations of 3.724 (2) and 3.767 (3) Å.

In the title salt, C(7)H(8)N(3) (+)·HSO(4) (-), the benzimdazole ring system is planar [mean deviation 0.0086 (1) Å]. In the crystal, N-H⋯O and O-H⋯O hydrogen-bond inter-actions give rise to a layer motif.

In the title compound, [Cu(C(7)H(3)Cl(2)O(2))(2)](n), the Cu(II) atom lies on a centre of inversion and adopts a [4+2] coordination mode, with two long axial Cu-Cl coordinative bonds complementing four Cu-O bonds from two 2,4-dichloro-6-formyl-phenolate ligands in a distorted square plane. π-π stacking inter-actions are also formed between neighbouring aromatic rings, with a centroid-centroid separation of 3.624 (2) Å.

The title compound, C(7)H(4)Cl(2)O(2), exhibits a layer crystal structure; mol-ecules within each layer are linked by weak C-H⋯O inter-molecular hydrogen bonds. There is also an intramolecular O-H⋯O hydrogen bond.

The title compound, C(7)H(4)Br(2)O(2), exhibits a layer packing structure via weak π-π stacking inter-actions [centroid-centroid distances between adjacent aromatic rings are 4.040 (8) and 3.776 (7) Å]. Mol-ecules in each layer are linked by inter-molecular O-H⋯O hydrogen bonding and Br⋯Br inter-actions [3.772 (4) Å]. There are two mol-ecules in the asymmetric unit.

PCR-DGGE was applied to analyze the microbial communities in rotating drum biofilter (RDB) for nitric oxide denitrifying removal under anaerobic conditions. The 16S rRNA genes (V3 region) were amplified with two universal primers (338F-GC and 518R). These amplified DNA fragments were separated by parallel DGGE. The DGGE profiles of biofilm samples from different sections of RDB are similar and about sixteen types of microorganisms are identified in the biofilm samples. These results show that microbial diversity of RDB firstly increases but then decreases with the addition of Cu II (EDTA) and the increase of NO removal efficiency. However, the change of microbial community is not significant during the process. Eight major bands of 16S rRNA genes fragments from DGGE profiles of biofilm samples were further eluted from gel, re-amplified, cloned and sequenced. The sequences of these fragments were compared with the database in GeneBank (NCBI). The gene analysis of 16S rRNA showed that the major populations are Cytopahga-Flexibacteria-Bacteroides (CFB) group Bacteroides, beta -Proteobacterium, gamma-Proteobacterium and Clostridium sp.. In addition, denitrification is related with band G-5, G-6 and G-8. G-5 is affiliated with gamma-Proteobacterium. Both G-6 and G-8 are affiliated with beta-Proteobacterium.

The title azo dye, 2-(2-methoxyethoxy)ethyl 4-[(5-cyano-1-ethyl-4-methyl-2,6-dioxo-1,2,3,6-tetrahydropyridin-3-ylidene)hydrazino]benzoate, C21H24N4O6, with a 1-ethyl-5-cyano-2-hydroxy-4-methyl-6-pyridone component, crystallizes in the hydrazone form. Hydrogen bonding mediates the formation of four-molecule aggregates, which are further grouped into an extended structure by pi-pi stacking interactions between the aromatic rings of adjacent molecules, with a centroid-centroid separation of 3.697 (2) A.

The title compound, (1S,3R)-3-carbamoyl-2,2,3-trimethylcyclopentane-1-carboxylic acid, C(10)H(17)NO(3), was synthesized and characterized by IR, EA, ES-MS (electrospray ionization mass spectra), (1)H NMR, (13)C NMR and X-ray diffraction techniques. The two independent molecules form a two-dimensional network via O-H.O and N-H.O hydrogen-bonding interactions between their carboxylic acid and carbamoyl groups.