[Occurrence Characteristics and Risk Assessment of Microplastics in Water and Sediments of Anhui Section of Huaihe River Basin].

The occurrence characteristics and ecological risk level of microplastics in the water and sediments of the Anhui section of Huaihe River Basin were analyzed via field sampling, stereomicroscopy, scanning electron microscopy, Fourier transform infrared spectroscopy (FTIR), risk index (H), and pollution load index (PLI) model. The current situation of microplastics in the water and sediments of the basin was analyzed, and the ecological risk assessment of microplastics was conducted. The results showed that the detection rate of microplastics at each site in the basin was 100%. The average abundance of microplastics in surface water and sediments was (39800±3367) n·m-3 and (5078±447) n·kg-1, respectively. The average abundance of microplastics in the downstream was higher than that in the upstream and midstream. The particle size of microplastics in water and sediments was primarily 20-150 µm, accounting for 82.96% and 80.77%, respectively. The microplastics were primarily fiber (water 76.05%, sediment 84.53%), film (water 21.83%, sediment 15.43%), and debris (water 2.12%, sediment 0.04%). The microplastics in water and sediments were primarily transparent, accounting for 63.31% and 83.69%, respectively. Polyethylene (65.74% in water and 80.62% in sediment) and polypropylene (18.43% in water and 9.71% in sediment) were the major components of water and sediments. Microplastics were primarily derived from agricultural films, abandoned fishing gear and nets, and artificially abandoned plastic bags in ports. The microplastic risk index (H) model assessment revealed that the risk index of some sites was high, and the risk level of microplastics in the Anhui section of Huaihe River Basin was grade II. The pollution load index (PLI) model assessment revealed that the ecological risk of surface water and sediments in the basin was generally low.

[Effect of Circular RNA hsa_circ_0067582 on the Proliferation and Invasion Ability of Gastric Cancer Cells].

Objective To investigate the effects on cell proliferation and invasion of the circular RNA hsa_circ_0067582 in gastric cancer(GC). Methods After hsa_circ_0067582 overexpression (Oe-circ_0067582) plasmid was transfected into AGS and SGC-7901 cells,the cell viability,proliferation,invasion ability,and apoptosis were detected by CCK-8,colony formation and EdU assays,Transwell assay,and flow cytometry,respectively.Western blotting was employed to detect the expression levels of proteins related to the cell apoptosis and epithelial-mesenchymal transition(EMT).The effect of Oe-circ_0067582 on the growth of SGC-7901 cells in nude mice was observed.Bioinformatics tools were used to predict the binding target miRNA of hsa_circ_0067582,and the competing endogenous RNA(ceRNA)regulatory network was established.Finally,functional enrichment was performed to analyze the biological functions of the target genes of the predicted miRNA. Results Compared with the pLO-ciR(empty plasmid)group,the Oe-circ_0067582 group in AGS and SGC-7901 cells attenuated the cell viability(t=7.883,P=0.001;t=5.679,P=0.005),proliferation(t=6.709,P=0.003;t=5.857,P=0.003),and invasion ability(t=7.782,P=0.002;t=6.342,P=0.003)and induced cell apoptosis(t=7.225,P=0.002;t=11.509,P=0.001).Western blotting showed that the Oe-circ_0067582 group in AGS and SGC-7901 cells up-regulated the protein levels of cysteinyl aspartate specific proteinase (Caspase) 3(t=6.863,P=0.002;t=7.024,P=0.001),Caspase 7(t=3.295,P=0.04;t=6.008,P=0.004),Caspase 9(t=4.408,P=0.012;t=6.278,P=0.004),and E-cadherin(t=12.453,P=0.002;t=10.867,P=0.001),while down-regulated those of Vimentin(t=7.242,P=0.002;t=5.694,P=0.004)and N-cadherin(t=6.480,P=0.003;t=7.446,P=0.001).Furthermore,Oe-circ_0067582 significantly inhibited the growth of tumor in the SGC-7901 tumor-bearing nude mice(t=3.526,P=0.017).The prediction based on TargetScan and miRnada suggested that hsa_circ_0067582 can competitively bind to hsa-miR-181b-3p,hsa-miR-337-3p,hsa-miR-421,and hsa-miR-548d-3p.The functional enrichment indicated that the target genes of miRNA were involved in multiple cancer-related biological processes including negative regulation of apoptotic process,gene expression,transcriptional misregulation in cancer,transforming growth factor-ß,and p53 signaling pathways. Conclusion Oe-circ_0067582 can inhibit the proliferation and attenuate EMT process to reduce the invasion ability of AGS and SGC-7901 cells,which provides a new target for the treatment of GC.

Rogue waves for the fourth-order nonlinear Schrödinger equation on the periodic background.

In this paper, we construct rogue wave solutions on the periodic background for the fourth-order nonlinear Schrödinger (NLS) equation. First, we consider two types of the Jacobi elliptic function solutions, i.e., dn- and cn-function solutions. Both dn- and cn-periodic waves are modulationally unstable with respect to the long-wave perturbations. Second, on the background of both periodic waves, we derive rogue wave solutions by combining the method of nonlinearization of spectral problem with the Darboux transformation method. Furthermore, by the study of the dynamics of rogue waves, we find that they have the analogs in the standard NLS equation, and the higher-order effects do not have effect on the magnification factor of rogue waves. In addition, when the elliptic modulus approaches 1, rogue wave solutions can reduce to multi-pole soliton solutions in which the interacting solitons form weakly bound states.

Binary Darboux transformation for the coupled Sasa-Satsuma equations.

The binary Darboux transformation method is applied to the coupled Sasa-Satsuma equations, which can be used to describe the propagation dynamics of femtosecond vector solitons in the birefringent fibers with third-order dispersion, self-steepening, and stimulated Raman scattering higher-order effects. An N-fold iterative formula of the resulting binary Darboux transformation is presented in terms of the quasideterminants. Via the simplest case of this formula, a few of illustrative explicit solutions to the coupled Sasa-Satsuma equations are generated from vanishing and non-vanishing backgrounds, which include the breathers, single- and double-hump bright vector solitons, and anti-dark vector solitons.

Microcystin-LR-induced phytotoxicity in rice crown root is associated with the cross-talk between auxin and nitric oxide.

Irrigation with cyanobacterial-blooming water containing microcystin-LR (MC-LR) poses threat to the growth of agricultural plants. Large amounts of rice (Oryza sativa) field in the middle part of China has been irrigating with cyanobacterial-blooming water. Nevertheless, the mechanism of MC-LR-induced phytotoxicity in the root of monocot rice remains unclear. In the present study, we demonstrate that MC-LR stress significantly inhibits the growth of rice root by impacting the morphogenesis rice crown root. MC-LR treatment results in the decrease in IAA (indole-3-acetic acid) concentration as well as the expression of CRL1 and WOX11 in rice roots. The application of NAA (1-naphthylacetic acid), an IAA homologue, is able to attenuate the inhibitory effect of MC-LR on rice root development. MC-LR treatment significantly inhibits OsNia1-dependent NO generation in rice roots. The application of NO donor SNP (sodium nitroprusside) is able to partially reverse the inhibitory effects of MC-LR on the growth of rice root and the expression of CRL1 and WOX11 by enhancing endogenous NO level in rice roots. The application of NO scavenger cPTIO [2-(4-carboxy-2-phenyl)-4,4,5,5-tetramethylinidazoline-1-oxyl-3-oxide] eliminates the effects of SNP. Treatment with NAA stimulates the generation of endogenous NO in MC-LR-treated rice roots. Treatment with NO scavenger cPTIO abolishes the ameliorated effect of NAA on MC-LR-induced growth inhibition of rice root. Treatment with SNP enhanced IAA concentration in MC-LR-treated rice roots. Altogether, our data suggest that NO acts both downstream and upstream of auxin in regulating rice root morphogenesis under MC-LR stress.

Dark and antidark solitons in the modified nonlinear Schrödinger equation accounting for the self-steepening effect.

In this paper, the modified nonlinear Schrödinger equation is investigated, which describes the femtosecond optical pulse propagation in a monomodal optical fiber. Based on the Wadati-Konno-Ichikawa system, another type of Lax pair and infinitely many conservation laws are derived. Dark and antidark soliton solutions in the normal dispersion regime are obtained by means of the Hirota method. Parametric regions for the existence of the dark and antidark soliton solutions are given. Asymptotic analysis of the two-soliton solution shows that collisions between two solitons (two antidark solitons, two dark solitons, and dark and antidark solitons) are elastic. In addition, collision between dark and antidark solitons reveals that dark and antidark solitons can co-exist on the same background in the normal dispersion regime.

Integrability study on a generalized (2+1)-dimensional variable-coefficient Gardner model with symbolic computation.

Gardner model describes certain nonlinear elastic structures, ion-acoustic waves in plasmas, and shear flows in ocean and atmosphere. In this paper, by virtue of the computerized symbolic computation, the integrability of a generalized (2+1)-dimensional variable-coefficient Gardner model is investigated. Painlevé integrability conditions are derived among the coefficient functions, which reduce all the coefficient functions to be proportional only to γ(t), the coefficient of the cubic nonlinear term u(2)u(x). Then, an independent transformation of the variable t transforms the reduced γ(t)-dependent equation into a constant-coefficient integrable one. Painlevé test shows that this is the only case when our original generalized (2+1)-dimensional variable-coefficient Gardner model is integrable.

Therapeutic effects of Clostridium butyricum on experimental colitis induced by oxazolone in rats.

AIM: To evaluate the therapeutic effects of a probiotic supplement (Clostridium butyricum, CGMCC0313) in a chemically-induced rat model of experimental colitis. METHODS: An experimental ulcerative colitis model was established by rectal injection of oxazolone into the colon of 40 Wistar rats randomly divided into four groups. The positive control group was sacrificed 3 d after colitis onset. The remaining groups were fed daily with either 2 mL of C. butyricum (2.3 x 10(11) CFU/L), 2 mL of mesalamine (100 g/L), or 1 mL of sodium butyrate (50 mmol/L) for 21 d. The animals' body weight, behavior, and bowel movements were recorded weekly. After sacrifice, visual and microscopic observations of pathological changes of colon tissue were made, body weight and wet colon mass index were measured and recorded, and serum levels of interleukin-23 (IL-23) and TNF-alpha were measured using ELISA. Expression of calcitonin gene-related peptide in colon tissue was measured by RT-PCR. Finally, changes in rat intestinal microflora status were measured in all groups. RESULTS: We found that treatment with C. butyricum lowered the serum levels of both IL-23 and tumor necrosis factor-alpha (TNF-alpha) with similar or even better efficiency than that of mesalamine or sodium butyrate. The rat intestinal flora appeared to recover more quickly in the group treated with C. butyricum than in the mesalamine and sodium butyrate groups. Finally, we found that the expression level of calcitonin gene related peptide was elevated in colon tissue in the sodium butyrate treated group but not in the C. butyricum or mesalamine treated groups, indicating a sensitization of colon following sodium butyrate treatment. CONCLUSION: In our experimental colitis model, treatment with C. butyricum CGMCC0313, a probiotic supplement, is at least as efficient as treatment with mesalamine.

Soliton interaction in the higher-order nonlinear Schrödinger equation investigated with Hirota's bilinear method.

The soliton interaction is investigated based on solving the higher-order nonlinear Schrödinger equation with the effects of third-order dispersion, self-steepening, and stimulated Raman scattering. By using Hirota's bilinear method, the analytic one-, two-, and three-soliton solutions of this model are obtained. According to those solutions, the relevant properties and features of physical and optical interest are illustrated. The results of this paper will be valuable to the study of signal amplification and pulse compression.

Integrability of an N-coupled nonlinear Schrödinger system for polarized optical waves in an isotropic medium via symbolic computation.

Considering the simultaneous propagation of multicomponent fields in an isotropic medium, an N-coupled nonlinear Schrödinger system with the self-phase modulation, cross-phase modulation, and energy exchange terms is investigated in this paper. First, via symbolic computation, the Painlevé singularity structure analysis shows that such a system admits the Painlevé property. Then, with the Ablowitz-Kaup-Newell-Segur scheme, the linear eigenvalue problem (Lax pair) associated with this model is constructed in the frame of the block matrices. With the Hirota bilinear method, the bright one- and two-soliton solutions of this system are presented. In addition, the bright multisoliton solutions of the system for N=2 are straightforwardly derived by the linear superposition of soliton solutions of two independent scalar nonlinear Schrödinger equations. Furthermore, through the analysis for the soliton solutions, the corresponding propagation behavior and applications for soliton pulses in nonlinear optical fibers are considered. Finally, three significant conserved quantities, i.e., energy, momentum, and Hamiltonian, are also given.

Types of solutions of the variable-coefficient nonlinear Schrödinger equation with symbolic computation.

By using Hirota's bilinear method and symbolic computation, solutions for a variable-coefficient nonlinear Schrödinger equation are obtained theoretically. It is found that the type of the solutions changes with the different choices of the group-velocity dispersion coefficient beta_{2}(z) . According to those solutions, the relevant properties and features of physical and optical interest are illustrated. In addition, an effective technique for controlling the shape of the pulses is presented. The results of this paper will be valuable to the study of the future development of ultrahigh rate and long-distance optical communication systems.

Batroxobin reduces intracellular calcium concentration and inhibits proliferation of vascular smooth muscle cells.

BACKGROUND: Batroxobin (BX), a serine protease used in defibrinogenation and thrombolysis, also has an effect on c-fos gene and growth factor. This study attempted to determine the effects of BX on the proliferation of vascular smooth muscle cells (VSMCs) and calcium metabolism. METHODS: VSMCs were treated with BX at concentrations of 0.1, 0.3, or 1.0 mmol/L and cell numbers were determined at 0, 24, 48, and 72 hours. Intracellular calcium concentration ([Ca2+]i) was measured using direct fluorescence methods. RESULTS: BX was found to suppress proliferation of VSMCs in a dose-dependent fashion with inhibition rates of 18% and 31% by 48 and 72 hours, respectively. In addition, BX decreases basal [Ca2+]i significantly. The basal level in untreated cells was 162.7 +/- 33.8 nmol/L, and decreased to 131.5 +/- 27.7 nmol/L, 128.3 +/- 28.5 nmol/L, and 125.6 +/- 34.3 nmol/L with the three concentrations of BX, respectively. Noradrenaline (NE)-induced [Ca2+]i stimulation was also attenuated by BX (0.1 mmol/L BX, 20% +/- 8% inhibition; 0.3 mmol/L BX, 54% +/- 11% inhibition; 1.0 mmol/L BX, 62% +/- 15% inhibition). The ability of NE to stimulate [Ca2+]i was attenuated in cultures in Ca(2+)-free medium, as was the ability of BX to blunt NE-induced stimulation. CONCLUSION: These findings demonstrate that BX can effectively inhibit proliferation of VSMCs, probably by blocking the release and uptake of Ca2+, thus influencing [Ca2+]i.