Theoretical Analysis of Gain and Threshold Current Density for Long Wavelength GaAs-Based Quantum-Dot Lasers'

Quantum dot gain spectra based on harmonic oscillator model are calculated including and excluding excitons. The effects of non-equilibrium distributions are considered at low temperatures. The variations of threshold current density in a wide temperature range are analyzed and the negative characteristic temperature and oscillatory characteristic temperature appearing in that temperature range are discussed. Also,the improvement of quantum dot lasers＇ performance is investigated through vertical stacking and p-type doping and the optimal dot density, which corresponds to minimal threshold current density,is calculated.

A case of steroid-dependent myeloid granulocytic sarcoma masquerading as Crohn's disease

Small bowel tumors and Crohn's disease are common causes of small bowel obstruction.Early stage neoplasms can easily be mistaken for Crohn's disease.Therefore,thorough work-ups including imaging studies and endoscopic evaluation with biopsies are critical for accurate diagnosis.Here we report a case of an otherwise healthy female with progressive onset of multiple,recurrent obstructive symptoms secondary to terminal ileal narrowing who was referred for management of steroid-dependent Crohn's disease.After thorough evaluation,the diagnosis was revised to myeloid granulocytic sarcoma involving the terminal ileum.In this case,a delay in diagnosis can be detrimental for prognosis,as myeloid granulocytic sarcoma is highly predictive of underlying acute myeloid leukemia and needs urgent referral for chemotherapy and/or resection.

Flow of Burgers' fluid over an inclined stretching sheet with heat and mass transfer

Effects of heat and mass transfer in the flow of Burgers fluid over an inclined sheet are discussed. Problems formulation and relevant analysis are given in the presence of thermal radiation and non-uniform heat source/sink. Thermal conductivity is taken temperature dependent. The nonlinear partial differential equations are simplified using boundary layer approximations. The resultant nonlinear ordinary differential equations are solved for the series solutions. The convergence of series solutions is obtained by plotting theη-curves for the velocity, temperature and concentration fields. Results of this work describe the role of different physical parameters involved in the problem. The Deborah numbers corresponding to relaxation time(β1 and β2) and angle of inclination(α) decrease the fluid velocity and concentration field. Concentration field decays as Deborah numbers corresponding to retardation time(β3) and mixed convection parameter(G) increase. Large values of heat generation/absorption parameters A/B, and the temperature distribution across the boundary layer increase. Numerical values of local Nusselt number,-θ′(0), and local Sherwood number,-f′(0), are computed and analyzed. It is found that θ′(0) increases with an increase in β3.

Interaction between enteric epithelial cells and Peyer's patch lymphocytes in response to Shigella lipopolysaccharide: Effect on nitric oxide and IL-6 release

AIM： TO investigate the effect of interaction between enteric epithelial cells and lymphocytes of Peyer＇s patch on the release of nitric oxide （NO） and IL-6 in response to Shigella lipopolysaccharide （LPS）. METHODS： Human colonic epithelial cells （Caco-2） were mixed cocultured with lymphocytes of Peyer＇s patch from wild-type （C57 mice） and inducible NO synthase knockout mice, and challenged with Shigella F2a-12 LPS. Release of NO and raiL-6 was measured by Griess colorimetric assay and enzyme-linked immunosorbent assay （ELISA）, respectively. RESULTS： In the absence of LPS challenge, NO was detected in the culture medium of Caco-2 epithelial cells but not in lymphocytes of Peyer＇s patch, and the NO release was further up-regulated in both cocultures with lymphocytes from either the wild-type or iNOS knockout mice, with a significantly higher level observed in the coculture with iNOS knockout lymphocytes. After Shigella F2a-12 LPS challenge for 24-h, NO production was significantly increased in both Caco-2 alone and the coculture with lymphocytes of Peyer＇s patch from the wild-type mice but not from iNOS knockout mice. LPS was found to stimulate the release of mIL-6 from lymphocytes, which was suppressed by coculture with Caco-2 epithelial cells. The LPS-induced mIL-6 production in lymphocytes from iNOS knockout mice was significantly greater than that from the wild-type mice. CONCLUSION： Lymphocytes of Peyer＇s patch maintain a constitutive basal level of NO production from the enteric epithelial cell Caco-2. LPS-induced mIL-6 release from lymphocytes of Peyer＇s patch is suppressed by the cocultured epithelial cells. While no changes are detectable in NO production in lymphocytes from both wild-type and iNOS knockout mice before and after LPS challenge, NO from lymphocytes appears to play an inhibitory role in epithelial NO release and their own mIL-6 release in response to LPS.

World Economy and the Export Dependence of China's Textile Industry

In this paper,the current status of export dependence of China's textile industry and affecting factors are evaluated.A cointegration test for world economy and China's export of textile and apparel is conducted which suggests that a long-term cointegration relationship exists between the growth rate of the world economy and that of China's export of textiles and apparel.The world economy will enter a period of low-speed growth,and the growth rate of China's textile and apparel exports will slow down accordingly.On the other hand,China's domestic expenditures on textiles and apparel are expected to maintain robust growth.According to the trends of exports and domestic demand,the export dependence of China's textile industry will go down with fluctuations.The conclusion is useful to evaluating the performance of the textile industry and making relevant policies.

言语行为的文化语用研究——论日语“依赖”表达形式

日语的“依赖”表达形式虽然有学者提到过， 但是还没有一个较为统一的意见。对日语“依赖”表达的定义及恰当条件、表达形式、会话结构等进行探讨， 分析不同文化背景在“依赖”表达上产生差异的原因， 将会有利于推动文化语用学的研究。

Asymptotic Dynamics of a Single-species Model with Resource-dependent Dispersal in One Dimension

In this paper,we study the asymptotic dynamics of a single-species model with resource-dependent dispersal in one dimension.To overcome the analytical difficulties brought by the resource-dependent dispersal,we use the idea of changing variables to transform the model into a uniform dispersal one.Then the existence and uniqueness of positive stationary solution to the model can be verified by the squeezing argument,where the solution plays a crucial role in later analyses.Moreover,the asymptotic behavior of solutions to the model is obtained by the upper-lower solutions method.The result indicates that the solutions of the model converge to the corresponding positive stationary solution locally uniformly in one dimension as time goes to infinity.

Tomographic inversion of near-surface Q factor by combining surface and cross-hole seismic surveys

The estimation of the quality factor Q plays a fundamental role in enhancing seismic resolution via absorption compensation in the near-surface layer.We present a new geometry that can be used to acquire field data by combining surface and cross-hole surveys to decrease the effect of geophone coupling on Q estimation.In this study,we drilled number of receiver holes around the source hole,each hole has different depth and each geophone is placed geophones into the bottom of each receiver hole to avoid the effect of geophone coupling with the borehole wall on Q estimation in conventional cross-hole seismic surveys.We also propose a novel tomographic inversion of the Q factor without the effect of the source signature,and examine its stability and reliability using synthetic data.We estimate the Q factors of the near-surface layer in two different frequency bands using field data acquired in the Dagang Oilfield.The results show that seismic absorption in the nearsurface layer is much greater than that in the subsurface strata.Thus,it is of critical practical importance to enhance the seismic solution by compensating for near-surface absorption.In addition,we derive different Q factors from two frequency bands,which can be treated,to some extent,as evidence of a frequency-dependent Q.

Substrate-dependent photoreactivities of BiOBr nanoplates prepared at different pH values

In this study,we showed that BiO Br nanoplates prepared at different pH values have substratedependent photocatalytic activities under visible-light irradiation. The BiO Br nanoplates synthesized at pH 1（BOB-1） degraded salicylic acid more effectively than did those obtained at pH 3（BOB-3）,but the order of their photocatalytic activities in rhodamine B（RhB） degradation were reversed. Electrochemical Mott–Schottky and zeta-potential measurements showed that BOB-1 had a more positive valence band and lower surface charge,leading to superior photocatalytic activity in salicylic acid degradation under visible light. However,BOB-3 was more powerful in RhB degradation because larger numbers of superoxide radicals were generated via electron injection from the excited RhB to its more negative conduction band under visible-light irradiation; this was confirmed using active oxygen species measurements and electron spin resonance analysis. This study deepens our understanding of the origins of organic-pollutant-dependent photoreactivities of semiconductors,and will help in designing highly active photocatalysts for environmental remediation.

Protective Effect of Ascorbate-Lysine on Carbon Tetrachloride and Alcohol-Induced Liver Injury in Mice

As an essential amino acid, lysine boosts protein synthesis (Nestor et al1997). Yao et al demonstrated that, lysine also exerts protective effect against the isch-emiclesion of brain. Meanwhile, vitamin C is a natural antioxidant, which has undisputable protectiveaction against free radical damages. In order to ascertain whether their combination could affordbetter effect, we have investigated the prophylactic effect of the couplant ascorbate-lysine inliver injuries.

Uniaxial compressive behavior of equal channel angular pressing Al at wide temperature and strain rate range

Uniaxial compressive experiments of ultrafine-grained Al fabricated by equal channel angular pressing(ECAP) method were performed at wide temperature and strain rate range. The influence of temperature on flow stress, strain hardening rate and strain rate sensitivity was investigated experimentally. The results show that both the effect of temperature on flow stress and its strain rate sensitivity of ECAPed Al is much larger than those of the coarse-grained Al. The temperature sensitivity of ultrafine-grained Al is comparatively weaker than that of the coarse-grained Al. Based on the experimental results, the apparent activation volume was estimated at different temperatures and strain rates. The forest dislocation interactions is the dominant thermally activated mechanism for ECAPed Al compressed at quasi-static strain rates, while the viscous drag plays an important role at high strain rates.

Sustained Contraction of Isolated Rabbit Thoracic Aortic Rings in Endothelial-dependent Manner Induced by βγ-CAT

In vertebrates, non-lens βγ-crystallins are widely expressed in various tissues and their functions are not well known. The molecular mechanisms of trefoil factors （TFFs）, which involved in mucosal healing and tumorigenesis, have remained elusive. βγ-CAT is a novel multifunctional protein complex of non-lens βγ-crystallin and trefoil factor from frog skin secretions. Here we report that βγ-CAT could induce sustained contraction of isolated rabbit aortic rings in dosage （2-35nmol/L） and endothelium dependent manners （P〈0.01 ）. In addition, in situ immunofluorescence indicated that positive TNF-α signals were mainly detected at the endothelial cell layer of βγ-CAT （25nmol/L） treated rings. Furthermore, βγ-CAT induced primary cultured rabbit thoracic aortic endothelial cells （RAECs） rapidly to release TNF-α. After βγ-CAT （25nmol/L） treated for 10 and 30min, the levels of the endothelial cells released TNF-ct were 34.17±5.10 pg/mL and 98.01±4.67 pg/mL （P〈0.01）, respectively. In conclusion, βγ-CAT could induce sustained contraction of isolated aortic rings, and the contractile effect might be partially explained by the release of TNF-α. These findings will give new insight into understanding the functions and physiological roles of non-lens βγ-crystallins and trefoil factors.

Modulation of γ-aminobutyric acid on painful sense in central nervous system of morphine-dependent rats

Objective To observe the effects of y-aminobutyric acid （GABA） on the electric activities of pain-excited neurons （PEN） in nucleus accumbens （NAc） in central nervous system （CNS） of morphine-dependent rats. Methods After GABA or the GABAA-receptor antagonist, bicuculline （Bic）, was injected into cerebral ventricles or NAc, right sciatic nerve was stimulated by electrical pulses, which was considered as traumatic pain stimulation. Extracellular recordings methods were used to record the electric activities of PEN in NAc. Results When GABA was injected into intracerebroventricle （ICV） as well as NAc, it could decrease the pain-evoked discharge frequency and prolong the latency of PEN. Bic could interdict the above effects of GABA on the electric activities of PEN. Conclusion Exogenous GABA might have an inhibitory effect on the central pain adjustment. Furthermore, GABA and GABAA receptor participate and mediate the traumatic information transmission process in CNS.

Temperature Dependence of the Energy-Band Structure for the Holstein Molecular-Crystal Model

We study the influences of the temperature on the energy-band structure for the Holstein molecular-crystal model. We show that the energy-band width and the energy-gap width of a solid are relevant to both the interaction between an electron and thermal phonons and to thermal expansion. For a one-dimensional Li atom lattice chain, under the chosen parameters,the width of the ls and 2s energy bands narrows as the temperature increases and the energy-gap width between the two bands widens. These results agree qualitatively with those observed experimentally. Studying temperature dependence of the energy-band structure is of great importance for understanding optical and transporting characteristics of a solid.

New text classification algorithm based on interdependence and equivalent radius

To improve the traditional classifying methods, such as vector space model （VSM）-based methods with highly complicated computation and poor scalability, a new classifying method （ called IER） is presented based on two new concepts： interdependence and equivalent radius. In IER, the attribute is selected according to the value of interdependence, and the classifying rule is based on equivalent radius and center of gravity. The algorithm analysis shows that IER is good at classifying a large number of samples with higher scalability and lower computation complexity. After several experiments in classifying Chinese texts, the conclusion is drawn that IER outperforms k-nearest neighbor （kNN） and classifcation based on the center of classes （CCC） methods, so IER can be used online to automatically classify a large number of samples while keeping higher precision and recall.

Group scheduling with general position-dependent effect

In order to investigate more realistic group scheduling problems with position-dependent effects,the model of general position-dependent group scheduling is proposed,where the actual group setup times and actual processing times are described by general functions of the normal group setup time and position in the sequence.These general functions are not assumed to have specific function structures,and are not restricted to be monotone.By mathematical analysis and proof,each considered problem is decomposed into a group scheduling process and a job scheduling process,and each scheduling process is transferred into the classic assignment problem or the classic single-machine sequence problem,and then the computational complexity to solve the considered problem is analyzed.Analysis results show that,even with general position-dependent job processing times,both the single machine makespan minimization group scheduling problems and the parallel-machine total load minimization group scheduling problems remain polynomially solvable.

Optimization and coordination model of information system security investment for interdependent risk

The impact of risk correlation on firm＇s investments in information system security is studied by using quantification models combining the ideas of the risk management theory and the game theory. The equilibrium levels of self-protection and insurance coverage under the non- cooperative condition are compared with socially optimal solutions, and the associated coordination mechanisms are proposed. The results show that self-protection investment increases in response to an increase in potential loss when the interdependent risk is small; the interdependent risk of security investments often induce firms to underinvest in security relative to the socially efficient level by ignoring marginal external costs or benefits conferred on others. A subsidy on self-protection investment from the government can help coordinate a firm＇s risk management decision and, thereby, improve individual security level and overall social welfare.

N-nitro-L-arginine Attenuates Morphine and Dihydroetorphine-induced Place Preference in Mice

Opiate dependence has become one of the most urgent problems of modernsociety. Opiate dependence involves physical and psychical dependence. Although many addicts can bedetoxified, the relapse ratio of 95% in 5 a demonstrates that opiate psychical dependence is aproblem more troublesome. It has been reported that acute and chronic administration of L- NNA canmarkedly retard the development of tolerance to physical dependence on morphine, and suppress theabstinence syndromes precipitated by naloxone in opiate dependent rodents, and even reverse theexisting morphine tolerance. However, the effect of L-NNA on the positive reinforcement ofpsychically active substances and its possible mechanism have not yet been reported. In presentstudy, the effect of L- NNA en the psychical dependence induced by opiates was evaluated on thebasis of conditioned place preference.

Gene Cloning and Expression of PKA Catalytic Subunit and Its Activity in Arabidopsis thaliana

Protein phosphorylation and dephosphorylation are the general means of regulation metabolism within a cell. A PKA catalytic subunit was found in Arabidopsis genome using Blast software. The cDNA was cloned by RT-PCR and sequencing result indicated a high degree of homology at protein level. The cDNA was subcloned into pET30a (+) and expressed in E. coli at different temperatures. The target protein was insoluble when induced at 37degreesC, while dissolvable if induced at 22degreesC with 0.01 mmol/L IPTG. Ni2+-NTA affinity chromatography was used to purify the target protein, which was shown to have cAMP-dependent protein kinase activity. Western blotting analysis indicated that stress treatments affected the expression of PKA catalytic subunit at protein level just to a small extent.

Note on a diffusive ratio-dependent predator-prey model

Subject to the homogeneous Neumann boundary condition, a ratio-dependent predator-prey reaction diffusion model is discussed. An improved result for the model is derived, that is, the unique positive constant steady state is the global stability. This is done using the comparison principle and establishing iteration schemes involving positive solutions supremum and infimum. The result indicates that the two species will ultimately distribute homogeneously in space. In fact, the comparison argument and iteration technique to be used in this paper can be applied to some other models. This method deals with the not-existence of a non-constant positive steady state for some reaction diffusion systems, which is rather simple but sufficiently effective.