Sublethal effects of emamectin benzoate on development, reproduction, and vitellogenin and vitellogenin receptor gene expression in Thrips hawaiiensis (Thysanoptera: Thripidae).

Thrips hawaiiensis (Morgan) (Thysanoptera: Thripidae) is a sap-sucking pest that seriously damages several crops and reduces their economic value. Exposure to low concentrations of insecticides may have a sublethal effect on surviving insects. In order to provide a reference for the rational application of emamectin benzoate, its sublethal effects on the development and reproduction of T. hawaiiensis were evaluated. Pupal development time was significantly shorter in T. hawaiiensis treated with sublethal concentrations of emamectin benzoate (LC10 and LC20) than in control. Female adult longevity and female total longevity were significantly longer following LC20 treatment than in the control and LC10 treatment groups. Nevertheless, male adult longevity and male total longevity were significantly shorter in the LC10 treatment group than in the control and LC20 treatment groups. The sublethal concentration of emamectin benzoate (LC20) significantly shortened the preadult stages and the mean generation. Meanwhile, it significantly increased the finite rate of increase, intrinsic rate of increase, and net reproductive rate. The fecundity was significantly higher after LC20 treatment than after LC10 and control treatments. Compared with the control group, the LC10 and LC20 groups of T. hawaiiensis adults showed a significantly higher expression of the vitellogenin (Vg) and vitellogenin receptor (VgR) genes, which played a key role in increasing their fecundity. These findings suggest that short-term exposure to sublethal concentrations of emamectin benzoate may lead to a resurgence and secondary outbreak of T. hawaiiensis infestation. The results have practical applications for the management of this important and noxious pest.

Modelling Thermally Induced Non-Equilibrium Gas Flows by Coupling Kinetic and Extended Thermodynamic Methods.

Thermally induced non-equilibrium gas flows have been simulated in the present study by coupling kinetic and extended thermodynamic methods. Three different types of thermally induced gas flows, including temperature-discontinuity- and temperature-gradient-induced flows and radiometric flow, have been explored in the transition regime. The temperature-discontinuity-induced flow case has shown that as the Knudsen number increases, the regularised 26 (R26) moment equation system will gradually loss its accuracy and validation. A coupling macro- and microscopic approach is employed to overcome these problems. The R26 moment equations are used at the macroscopic level for the bulk flow region, while the kinetic equation associated with the discrete velocity method (DVM) is applied to describe the gas close to the wall at the microscopic level, which yields a hybrid DVM/R26 approach. The numerical results have shown that the hybrid DVM/R26 method can be faithfully used for the thermally induced non-equilibrium flows. The proposed scheme not only improves the accuracy of the results in comparison with the R26 equations, but also extends their capability with a wider range of Knudsen numbers. In addition, the hybrid scheme is able to reduce the computational memory and time cost compared to the DVM.

Lattice Boltzmann modeling of fluid-particle interaction based on a two-phase mixture representation.

In this work, we derive a lattice Boltzmann model for fluid-particle interaction by considering the system as a two-phase mixture. A partially saturated type scheme is achieved rigorously without any viscosity-dependent weight parameter. The scheme is of second-order accuracy in both space and time including the body-force term. Moreover, we devise a scheme suitable for the scenario where two or more particles intersect a single computational cell, typically occurring for particles in contact or close to contact. Good performance is found when the present scheme is validated against three classic problems, namely the flow past a stationary cylinder, a cylindrical particle settling in a channel under gravity, and the flow around two impacting cylinders.

Linearized-moment analysis of the temperature jump and temperature defect in the Knudsen layer of a rarefied gas.

Understanding the thermal behavior of a rarefied gas remains a fundamental problem. In the present study, we investigate the predictive capabilities of the regularized 13 and 26 moment equations. In this paper, we consider low-speed problems with small gradients, and to simplify the analysis, a linearized set of moment equations is derived to explore a classic temperature problem. Analytical solutions obtained for the linearized 26 moment equations are compared with available kinetic models and can reliably capture all qualitative trends for the temperature-jump coefficient and the associated temperature defect in the thermal Knudsen layer. In contrast, the linearized 13 moment equations lack the necessary physics to capture these effects and consistently underpredict kinetic theory. The deviation from kinetic theory for the 13 moment equations increases significantly for specular reflection of gas molecules, whereas the 26 moment equations compare well with results from kinetic theory. To improve engineering analyses, expressions for the effective thermal conductivity and Prandtl number in the Knudsen layer are derived with the linearized 26 moment equations.

Nonequilibrium gaseous heat transfer in pressure-driven plane Poiseuille flow.

Nonequilibrium heat and mass transfer in a pressure-driven plane Poiseuille flow is investigated using the direct simulation Monte Carlo method from the early slip to the free molecular regime. Our investigations reveal several nonintuitive, nonequilibrium thermal flow patterns, including expansion cooling near the walls, a nonconstant pressure profile, and counter-gradient heat transfer along the channel center-line. A bimodal trend in the tangential heat flux is found in the slip and the early transition regime. In the upper transition and free molecular regime, the net heat flow in the entire channel is largely unidirectional and in the opposite direction of mass flow. However, in the slip and the early transition regime, a two-way heat flow is observed in the channel as the normal heat flux profile plays a key role in determining the net gaseous heat flow direction. Moreover, the heat flow rate profile exhibits a maximum value at an intermediate value of Knudsen number. The effects of incomplete surface accommodation on nonequilibrium heat flow are also investigated in this work. It is shown that for very low values of the accommodation coefficient, the gaseous heat flow direction is reversed and is consistently in the direction of mass flow.

[Relationship between the expression of HBV DNA, HBV cccDNA in human ovary tissues and the HBV intrauterine infection].

OBJECTIVE: To investigate the relationship between hepatitis B virus (HBV) deoxyribonucleic acid (DNA) and HBV covalently closed circular DNA (cccDNA) in the ovary and HBV intrauterine infection. METHODS: HBV DNA and HBV cccDNA were assayed in the ovaries of 33 pregnant women who were positive for HBV DNA, tested by Fluorescent quantitative polymerase chain reaction (FQ-PCR). The level of HBV mark (HBVM) and the content of HBV DNA in peripheral blood of infants were measured by chemoluminescence and FQ-PCR methods respectively. RESULTS: The overall positive rate for both HBV DNA and HBV cccDNA in ovarian samples was 51.52% (17/33). The rate on intrauterine infection among infants was 12.12% (4/33) and all the 4 infected infants were delivered from mothers with normal hepatic function. When HBV DNA and HBV cccDNA were both positive, the rate of intrauterine infection in infants was significantly higher than those who were with both negative results (P < 0.05). Levels of HBV cccDNA and the rate of positive samples were significantly higher in mothers with infants who appeared to have had intrauterine infection than those did not (P < 0.01 and < 0.05, respectively). CONCLUSION: HBV infection could be discovered in the human ovary and might be transmitted to the filial generation via ovum.

Solvent effect on the construction of two microporous yttrium-organic frameworks with high thermostability via in situ ligand hydrolysis.

Two novel yttrium trimesates with open frameworks have been synthesized by the self-assembly of trimethyl 1,3,5-benzenetricarboxylate and Y(3+) ion in mixed solvent of dimethylformamide (DMF)/water and diethylformamide (DEF)/water, where changes of solvents with different molecular sizes lead to the formation of two similar three-dimensional frameworks with different spatial arrangement styles of the linkers around the Y(3+) centers, and solvent-dependent one-dimensional channels (ca. 6.2 x 7.7 A(2)) along the [100] direction, as shown by X-ray crystallography. Structural analyses indicate that they have excellent thermal stabilities which are endurable up to 490 degrees C.

Analysis of the slip coefficient and defect velocity in the Knudsen layer of a rarefied gas using the linearized moment equations.

The linearized R13 and R26 moment equations are used to study Kramers' problem. Analytical solutions for the defect velocity and slip coefficient are derived and compared with numerical results from the kinetic theory. It is found that the linearized R26 equations can capture the Knudsen layer fairly accurately in terms of the defect velocity and slip coefficient, while the linearized R13 equations underpredict the kinetic data. At the wall, however, the kinetic models predict a slightly higher value for the defect velocity than the linearized R26 equations. In general, the linearized R26 equations perform well for both specular and diffusive walls.

Recent advances in computational fluid dynamics relevant to the modelling of pesticide flow on leaf surfaces.

Increasing societal and governmental concern about the worldwide use of chemical pesticides is now providing strong drivers towards maximising the efficiency of pesticide utilisation and the development of alternative control techniques. There is growing recognition that the ultimate goal of achieving efficient and sustainable pesticide usage will require greater understanding of the fluid mechanical mechanisms governing the delivery to, and spreading of, pesticide droplets on target surfaces such as leaves. This has led to increasing use of computational fluid dynamics (CFD) as an important component of efficient process design with regard to pesticide delivery to the leaf surface. This perspective highlights recent advances in CFD methods for droplet spreading and film flows, which have the potential to provide accurate, predictive models for pesticide flow on leaf surfaces, and which can take account of each of the key influences of surface topography and chemistry, initial spray deposition conditions, evaporation and multiple droplet spreading interactions. The mathematical framework of these CFD methods is described briefly, and a series of new flow simulation results relevant to pesticide flows over foliage is provided. The potential benefits of employing CFD for practical process design are also discussed briefly.

[Effectiveness and safety of bicyclol combined with thymosin in treatment of chronic viral hepatitis B].

OBJECTIVE: To analyze the efficacy and safety of bicyclol combined with thymosin in treatment of chronic viral hepatitis B (CHB). METHODS: A total of 135 patients with CHB were randomized into experimental group and control group. The patients in the experimental group received bicyclol orally 75 mg daily and thymosin 20 mg intramuscular injection once every 2 days for 24 weeks and those in control group received bicyclol orally 75 mg daily alone for 24 weeks. The levels of serum aminotransferase (ALT/AST), HBV-DNA, HBeAg /antiHBe were observed. RESULTS: Compared with pre-treatment levels, the serum aminotransferase levels decreased significantly in both groups, but there were no statistically significant differences between them. HBeAg negative conversion rate was significantly higher in the experimental group than in the control group (35.3 percent vs.19.4 percent, P less than 0.05). HBV DNA negative conversion rate was significantly higher in the experimental group than in the control group (36.7 percent vs. 20.9 percent, P less than 0.05). No obvious adverse events which were probably related to the drugs were observed in this study. CONCLUSION: The combination of bicyclol with thymosin had better effect in treatment of chronic hepatitis B ias compared with bicyvlol alone.

Capturing Knudsen layer phenomena using a lattice Boltzmann model.

In recent years, lattice Boltzmann methods have been increasingly used to simulate rarefied gas flows in microscale and nanoscale devices. This is partly due to the fact that the method is computationally efficient, particularly when compared to solution techniques such as the direct simulation Monte Carlo approach. However, lattice Boltzmann models developed for rarefied gas flows have difficulty in capturing the nonlinear relationship between the shear stress and strain rate within the Knudsen layer. As a consequence, these models are equivalent to slip-flow solutions of the Navier-Stokes equations. In this paper, we propose an effective mean-free path to address the Knudsen layer effect, so that the capabilities of lattice Boltzmann methods can be extended beyond the slip-flow regime. The model has been applied to rarefied shear-driven and pressure-driven flows between parallel plates at Knudsen numbers between 0.01 and 1. Our results show that the proposed approach significantly improves the near-wall accuracy of the lattice Boltzmann method and provides a computationally economic solution technique over a wide range of Knudsen numbers.

[Effects of nitric oxide synthases on kidney in early phase of endotoxic shock in macaque].

OBJECTIVE: To study the pathogenesis of kidney injury in early phase of endotoxic shock. METHODS: Eleven macaques were anesthetized and randomly divided into two groups: an experimental group (n=6), receiving a dose of 2.8 mg/kg lipopolysaccharides (LPS) by intravenous injection, and a control group (n=5), injected with normal saline of 1 ml/kg. The animals were sacrificed 120 minutes following endotoxin injection. With immunohistochemical technique endothelium nitric oxide synthases (eNOS) and inducible nitric oxide synthases (iNOS) protein of the renal tissue were determined. The ultrastructure was studied with electron microscope. Acid phosphatase (ACP) was also assayed. RESULTS: One hundred and twenty minutes after LPS challenge, damages to the glomerulus and renal tubules were found, and lysosomes were increased in the renal cells. iNOS was positively expressed in vascular endothelium of glomerulus and epithelium of renal tubules in the experimental group, but not in the control group. eNOS was positively expressed in vascular endothelium of glomerulus; and peri-vascular region in both groups. CONCLUSION: The present findings indicate that NO contributed to the pathogenesis of renal injury in the early phase of endotoxic shock in primates.

An analysis of induced pressure fields in electroosmotic flows through microchannels.

Induced pressure gradients are found to cause band-broadening effects which are important to the performance of microfluidic devices, such as capillary electrophoresis and capillary chromatography. An improved understanding of the underlying mechanisms causing an induced pressure gradient in electroosmotic flows is presented. The analysis shows that the induced pressure distribution is the key to understanding the experimentally observed phenomena of leakage flows. A novel way of determining the static pressures at the inlet and outlet of microchannels is also presented that takes account of the pressure losses due to flow contraction and expansion. These commonly neglected pressure losses at the channel entrance and outlet are shown to be important in accurately describing the flow. The important parameters that define the effect of induced pressure on the flows are discussed, which may facilitate the design of improved microfluidic devices. The present model clearly identifies the mechanism behind the experimentally observed leakage flows, which is further confirmed by numerical simulations. Not only can the leakage flow occur from the electric-field-free side channel to the main channel, but also the fluid in the main channel can be attracted into the side channel by the induced pressure gradient.

[Changes of blood-cerebrospinal fluid barrier in rabbits with diabetic ketoacidosis].

OBJECTIVE: To explore the mechanism of the changes of blood-cerebrospinal fluid barrier in rabbits with diabetic ketoacidosis (DKA). METHODS: The New Zealand rabbits were injected with 150 mg/kg streptozotion and alloxan monohydrate each (model group, n=6) intravenously, or equal volume of normal saline (control group, n=6). After 72 hours, blood sugar and uric ketone were detected. All of animals were injected with Evans blue (EB). After 6 hours, arterial blood gases were measured and animals were killed. Absorbency of EB of brain tissue was detected. All brains of animals were examined with light and electron microscopy. Marker of blood-cerebrospinal fluid barrier, cytochemical stains of alkaline phosphatase (ALPase) was operated by ultrastructure. The inducible nitric oxide synthase (iNOS) in brain tissue was detected by immunohistochemical method. RESULTS: The models of DKA were established after 72 hours of injecting streptozotion and alloxan monohydrate. Absorbency of EB of model group rabbits was slightly increased, but had no significant difference compared with controls (P>0.05). The brain edema, damages of vessel endothelium and necrosis of neuron were observed through histological and ultrastructure examination in model group. ALPase activity of model group was evidently decreased in brain blood vessel endothelium in comparison with controls. Compared to controls, the iNOS activity of model group was increased and its positive cells were aggregated on blood vessel of brain membrane. CONCLUSION: By streptozotion and alloxan monohydrate inducing DKA models, NO could induce blood-cerebrospinal fluid barrier damages and result in brain edema.