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Bladder cancer is the most common malignant urinary system tumor. Chemotherapy is frequently used as a treatment regimen for patients with bladder cancer, however, new and effective drugs for bladder cancer need to be developed. The present study examined the effects and mechanisms of Ag-SP-DNC, a silver and singly-protonated dehydronorcantharidin complex, on bladder cancer in vitro and in vivo. It was identified that Ag-SP-DNC suppressed cell proliferation and induced apoptosis in bladder cancer cells in vitro, a suppression associated with G0/G1 phase arrest and elevated intracellular reactive oxygen species (ROS) levels. Furthermore, Ag-SP-DNC enhanced the cleaved caspase-3 levels, disrupted the mitochondrial transmembrane potential balance, and induced intracellular calcium overload. The Ag-SP-DNC-induced bladder cancer cell apoptosis was significantly decreased following treatment with a broad caspase inhibitor, zVAD-fmk. In addition, treatment of MB49 tumor-bearing mice with Ag-SP-DNC significantly inhibited tumor growth and decreased the anti-apoptosis and cell cycle promotion protein levels in the tumor. The results of the present study suggested that Ag-SP-DNC elicits a strong anticancer effect against bladder cancer, and can therefore be used as a promising treatment for bladder cancer.

In this article, the relative stability of graphite and diamond is calculated and compared by cp2k software. Quantum calculation proves that graphite is more stable than diamond, and the energy difference between them is about 612.449 kcal / mol if 192 carbon atoms are filled in one unit cell. All assignments are aimed at helping students gain practice with computational chemistry software while at the same time understanding the different stability between different crystal structures. Given the facts that CP2K is free, all calculations are simple, convenient and reliable, this work provides a solution to the similar problems encountered in Chemistry teaching, especially those about crystal structures.

Quantum dots (QDs) are a kind of nanostructured semiconductor crystals with the size range of 1–10 nm. Their unique photophysical properties and potential toxicity to human health have aroused wide concern of scientists and general public. However, the interaction mechanism of QDs on human serum albumin (HSA, the vital protein in human blood) from both structural and functional perspectives is rarely reported. In the present work, effects of N-acetyl- L -cysteine-capped CdTe quantum dots with fluorescence emission peak at 612 nm (QDs-612) on the conformation and function of HSA were investigated by spectroscopic methods, molecular docking study and esterase activity assay. The hydrophobic interaction between HSA and QDs-612 was spontaneous with the binding constants calculated to be 6.85×105 L mol−1 (298 K) and 8.89×105 L mol−1 (308 K). The binding of QDs-612 to HSA induced the static quenching of fluorescence and the changes of secondary structure and microenvironment of Tyr-411 residue, which resulted in serious decrease on the hydrolysis of substrate p-nitrophenylacetate in esterase activity assay of HSA. This work confirms the possibility on direct interaction of QDs-612 with HSA and obtains a possible mechanism of relationship between conformation and function of HSA.

Human serum albumin (HSA) is the most prominent protein in blood plasma with important physiological functions. Although copper is an essential metal for all organisms, the massive utilization of copper has led to concerns regarding its potential health impact. To better understand the potential toxicity and toxic mechanisms of Cu(2+), it is of vital importance to characterize the interaction of Cu(2+) with HSA. The effect of Cu(2+) on the structure and function of HSA in vitro were investigated by biophysical methods including fluorescence techniques, circular dichroism (CD), time-resolved measurements, isothermal titration calorimetry (ITC), molecular simulations and esterase activity assay. Multi-spectroscopic measurements proved that Cu(2+) quenched the intrinsic fluorescence of HSA in a dynamic process accompanied by the formation of complex and alteration of secondary structure. But the Cu(2+) had minimal effect on the backbone and secondary structure of HSA at relatively low concentrations. The ITC results indicated Cu(2+) interacted with HSA spontaneously through hydrophobic forces with approximately 1 thermodynamic identical binding sites at 298 K. The esterase activity of HSA was inhibited obviously at the concentration of 8 × 10(-5) M. However, molecular simulation showed that Cu(2+) mainly interacted with the amino acid residues Asp (451) by the electrostatic force. Thus, we speculated the interaction between Cu(2+) and HSA might induce microenvironment of the active site (Arg 410). This study has provided a novel idea to explore the biological toxicity of Cu(2+) at the molecular level.

In recent years, wetland ecological water requirements (EWRs) have been estimated by using hydrological and functional approaches, but those approaches have not yet been integrated for a whole ecosystem. This paper presents a new method for calculating wetland EWRs, which is based on the response of habitats to water level, and determines water level threshold through the functional integrity of habitats. Results show that in the Huanghe (Yellow) River Delta water levels between 5.0 m and 5.5 m are required to maintain the functional integrity of the wetland at a value higher than 0.7. One of the dominant plants in the delta, Phragmites australis, tolerates water level fluctuation of about ± 0.25 m without the change in wetland functional integrity. The minimum, optimum and maximum EWRs for the Huanghe River Delta are 9.42×106 m3, 15.56×106 m3 and 24.12×106 m3 with water levels of 5.0 m, 5.2 m and 5.5 m, corresponding to functional integrity indices of 0.70, 0.84 and 0.72, respectively. A wetland restoration program has been performed, which aims to meet these EWRs in attempt to recover from losses of up to 98% in the delta’s former wetland area.

The interactions of N7,N9-dimethylguaninium with different anions (fluoride, bromide or tetrafluoroborate) and the related electronic properties are reported. The calculations show that the cation interactions with one to three different anion(s) give 31 stable structures. Among these structures, the cation interactions with two anions, especially with N1 H (or/and N2 Ha) and C8 H of guanine, are the most favorable, while with one anion are the least favorable. Moreover, with the increase of the anionic radius, the interaction energies are decreased. NBO analyses reveal that the interactions between the F anion(s) with the cation mainly occur through the formation of F H/C covalent bond besides F lp → σ C/N H ∗ or/and F lp → π C8 N7 ∗ interaction(s). However, with the increase of the anionic radius, the designed pairs are more favorable for the ionic bond, which may suggest that N7,N9-dimethylguaninium fluoride is not suitable to be selected as an ionic liquid.

The acidities of multiple sites in Cu(+)-adenine and Cu(2+)-adenine complexes have been investigated theoretically. To compare, the acidities of adenine (A) and adenine radical cation (A(*+)) have also been included. The results clearly indicate that the acidities of C-H and N-H groups in Cu(+/2+)-adenine are significantly enhanced relative to the neutral adenine. The acidic order for a given site on adenine and adenine derivatives is as follows: Cu(2+)-adenineA(*+)Cu(+)-adenineA. For Cu(+)-adenine and Cu(2+)-adenine, N3-coordination exhibits N9-H acid, and N1- and N7-coordination exhibits N6-H(a) and N6-H(b) acid, respectively. Additionally, it is found that C2-H group is surprisingly acidic in the coordination complexes. Calculations in aqueous solution reveal that our results can be extrapolated to aqueous solution. Analyses of the electronic properties interpret the highest acidity of Cu(2+)-adenine among the adenine derivatives studied. Also, Electrostatic potential calculations of [A(-H(+))](-) and [A(-H(+))](*) indicate that the removal of H(a) or H(b) from the amino group favors the bidentate coordination, which provides a dative bond from the deprotonated N and the original coordination ligand to copper ion besides the electrostatic interaction between them and thereby stabilizes the [A(-H(+))](-)/[A(-H(+))](*). NBO analysis confirms the electrostatic potential result.

We investigated and monitored a reed community in the fields. Data on the bio-ecological characteristics and β-diversity of reed communities in different environmental gradients (mainly based on water depth) of the Yellow River Delta were collected through multianalysis, extremum analysis and β-diversity index analysis. In accordance with the square sum of deviations (Ward) cluster analysis, 10 sampling plots were divided into six types with the dominant plants in different plots varying according to the change in environmental gradients. The dominant plants in these plots varied from aquatic plants to xerophytes and salt tolerant plants as water depth decreased. The average height and diameter of the reeds at breast level were significantly correlated with the average water depth. The fitness curves of average density and coverage with average water depth were nonlinear. When the average water depth was 0.3 m, the average density and coverage of reeds reached the apex value, while the height and diameter of the reeds at breast level increased with the water depth. There were obvious changes to the environmental gradient in the Yellow River Delta. The transitional communities were also found to exist in the Yellow River Delta by β-diversity analysis. Vicarious species appeared with the change in water depth. The occurrence of substitute species is determined by the function of common species between adjacent belts. The different functions of common species led to differences in community structure and function and differences in dominant plants. The result reflects the variations of species present in different habitats and directly reflects environmental heterogeneity. The values of β-diversity indices of adjacent plots were higher than those of nonadjacent plots. There are transition zones between the xerophytes and aquatic plants in the Yellow River Delta. In an aquatic environment, the similarity of reed community is higher than that of xeromorphic plants. The β-diversity index can reflect plant succession trends caused by the change in environmental gradients in the Yellow River Delta. The β-diversity index reveals plant responses to changes in environmental gradient and is helpful in observing changes in patterns of species diversity in relation to environmental gradient change and evolving trends in the future, which in turn plays a prominent role when environmental water requirements of wetland are discussed.

The single-crystalline β-FeOOH hollow nanorods with a diameter ranging from 20∼30 nm and length in the range of 70–110 nm have been successfully synthesized through a two-step route in the solution. The phase transformation and the morphologies of the hollow β-FeOOH nanorods were investigated with X-ray powdered diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), selected area electric diffraction (SAED), high-resolution transmission electron microscopy (HRTEM), infrared spectrum (IR) and thermo-gravimetric analysis (TGA). These studies indicate that the first step is an incomplete-reaction course. Furthermore, The formation mechanism of the hollow nanorods has been discussed. It is found that the mixed system including chitosan and n-propanol is essential for the final formation of the hollow β-FeOOH nanorods.

Human serum albumin (HSA) is the most prominent protein in blood plasma with important physiological functions. Although copper is an essential metal for all organisms, the massive utilization of copper has led to concerns regarding its potential health impact. To better understand the potential toxicity and toxic mechanisms of Cu(2+), it is of vital importance to characterize the interaction of Cu(2+) with HSA. The effect of Cu(2+) on the structure and function of HSA in vitro were investigated by biophysical methods including fluorescence techniques, circular dichroism (CD), time-resolved measurements, isothermal titration calorimetry (ITC), molecular simulations and esterase activity assay. Multi-spectroscopic measurements proved that Cu(2+) quenched the intrinsic fluorescence of HSA in a dynamic process accompanied by the formation of complex and alteration of secondary structure. But the Cu(2+) had minimal effect on the backbone and secondary structure of HSA at relatively low concentrations. The ITC results indicated Cu(2+) interacted with HSA spontaneously through hydrophobic forces with approximately 1 thermodynamic identical binding sites at 298 K. The esterase activity of HSA was inhibited obviously at the concentration of 8 × 10(-5) M. However, molecular simulation showed that Cu(2+) mainly interacted with the amino acid residues Asp (451) by the electrostatic force. Thus, we speculated the interaction between Cu(2+) and HSA might induce microenvironment of the active site (Arg 410). This study has provided a novel idea to explore the biological toxicity of Cu(2+) at the molecular level.

The synthesis of Mg(OH) 2 one-dimensional (1D) nanostructures was systematically investigated in different solvents at various temperatures with Mg 10 OH 18 Cl 2 ·5H 2 O nanowires as source materials. The results showed that the characters of the products, such as crystal size, shape, and structure, were strongly influenced by the solvent and temperature during the solvothermal process. 1D nanotubes of Mg(OH) 2 , with 80–300 nm outer diameter, 30–80 nm wall thickness, and several tens of micrometers in length were obtained by choosing bidentate ligand solvents such as ethylenediamine and 1,6-diaminohexane as the reaction solvent. But when using monodentate ligand pyridine as the reaction solvent, the obtained samples showed nanorods morphology. The Mg(OH) 2 thus produced was analyzed by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), high-resolution electron microscopy (HRTEM), and selected-area electron diffraction (SAED). The possible growth mechanism of the 1D nanostructure Mg(OH) 2 was discussed.

A convenient hydrothermal processing followed by a postheat treatment route is proposed to synthesize well-dispersed, branched β-MnO2 multipods from a branched γ-MnOOH precursor. The key steps in our approach are as follows: (1) by controlling the reactant concentration and reaction time, the monoclinic phase of MnOOH with novel branched multipod nanostructures is synthesized via the hydrothermal reaction of MnSO4·H2O and NaClO3 at 160 °C for 200 min; (2) the prepared branched γ-MnOOH multipods are heated under an air atmosphere at 400 °C for 2 h, and the branched β-MnO2 nanostructures can be successfully obtained without changing the precursor morphologies. The new structures presented here enrich the nanoscale community with new basic materials and offer a new approach for increasing structural complexity and enabling greater potential applications. Furthermore, brief discussions about their formation mechanisms provide insight into the formation processing of other transition-metal oxide multipods.

The structures, infrared spectra, and electronic properties of the N7,N9-dimethylguaninium chloride have been studied. The interaction of one cation with one to four Cl anions and one Cl anion with two cations were investigated. Fifteen stable conformers are obtained. It is found that there are four acidic regions in the vicinity of the guaninium cations. In these regions, the cation could H-bond with one to three Cl anions but no more than three nearest anions. One Cl anion could H-bond with two cations. Additionally, evidence of a Cl...pi interaction between the anion and cation is observed. Among these structures, one cation interaction with two anions and two cations interaction with one anion have the larger interaction energies than the other series. Natural bond orbital analyses and molecular orbitals reveal that the charge transfer from anion(s) to the cation(s) occurs mainly through either the Cllp --sigma C-H, Cllp --sigma N-H, or Cllp --pi C8-N7 interactions. The interaction between Cl and sigma (C/N-H) or pi C-N produces a small bond order. This indicates that the Cl...H (Cl...pi) interaction exhibits a weak covalent character and suggests a strong ionic H-bond (Cl...pi bond). What's more, formation of Cl...H/Cl...pi bond decreases the bond order of the associated C/N-H bond or C8-N7 bond. In addition, examination of vibrational spectrum of each conformer explains the origin of H-bonding character.