Search

Despite the high capacity and low cost of lithium-sulfur (Li-S) batteries, their commercialization is greatly blocked by multiple bottlenecks including the shuttle effect of lithium polysulfides (LiPSs), poor conductivity of sulfur, and sluggish reaction kinetics. Herein, we propose novel two-dimensional MSi

Prussian blue analogs (Na2FeFe(CN)6) have been regarded as potential cathode materials for sodium-ion batteries (SIBs) due to their low-cost iron resources and open framework. Herein, the detailed first-principles calculations have been performed to investigate the electrochemical properties of Na x FeFe(CN)6 during Na ion extraction. The material undergoes a phase transition from a dense rhombohedral to open cubic structure upon half-desodiation, which is resulted from competition of the Na−N Coulomb attraction and d−π covalent bonding of Fe−N. The analyses on the density of states, magnetic moments and Bader charges of Na x FeFe(CN)6 reveal that there involve in the successive redox reactions of high-spin Fe2+/Fe3+ and low-spin Fe2+/Fe3+ couples during desodiation. Moreover, the facile three-dimensional diffusion channels for Na+ ions exhibit low diffusion barriers of 0.4 eV ∼ 0.44 eV, which ensures a rapid Na+ transport in the Na x FeFe(CN)6 framework, contributing to high rate performance of the battery. This study gives a deeper understanding of the electrochemical mechanisms of Na x FeFe(CN)6 during Na+ extraction, which is beneficial for the rational design of superior PBA cathodes for SIBs.

To evaluate the clinical significance and molecular mechanism of bladder cancer-associated transcript 1 (BLACAT1) in non-small-cell lung cancer (NSCLC).Overall, 156 NSCLC cancer patients were recruited and divided into high and low BLACAT1 level group by the median value of BLACAT1 expression. The associations of BLACAT1 expression with the clinicopathological features and prognosis were evaluated. A series of in vitro assays were performed to explore the role of BLACAT1 on NSCLC progression and metastasis.Patients with high BLACAT1 expression had shorter overall survival and progression-free survival than those with low BLACAT1 expression. Multivariate analyses showed that BLACAT1 was an independent prognostic factor of survival in NSCLC patients. In vitro assays showed that the downregulation of BLACAT1 significantly suppressed cell progression, migration, and invasion. The epithelial-mesenchymal transition was also inhibited when BLACAT1 was silenced, indicated by an increase in E-cadherin expression and a decrease in vimentin expression by mediating Wnt/β-catenin signaling pathway.BLACAT1 should be a potential prognostic biomarker and therapeutic target for NSCLC.

DNA vaccine against human immunodeficiency virus type-1 (HIV-1) can induce substantial levels of HIV-1-specific humoral and cell-mediated immunity. To develop more potent HIV-1 DNA vaccine formulations, we used a murine model to explore the immunomodulatory effects of an interleukin-2 (IL-2) expression plasmid on an HIV-1 DNA vaccine following intranasal administration of the combination. When the vaccine and expression plasmid were incorporated into cationic liposomes and administered to mice, the HIV-1-specific delayed-type hypersensitivity response and cytotoxic T lymphocyte activity were significantly increased. Restimulated immune lymphoid cells showed enhanced production of both IL-2 and interferon-gamma and reduced secretion of IL-4. The level of total antibody to HIV-1 antigen was not greatly changed by coadministration of the DNA vaccine and IL-2 expression plasmid. An analysis of serum HIV-1-specific IgG subclasses showed a significant drop in the IgG1/IgG2a ratio in the group that received the plasmid-vaccine combination. These results demonstrate that the IL-2 expression plasmid strongly enhances the HIV-1-specific immune response via activation of T helper type-1 cells.

One result of both theoretic and practical importance regarding point processes is the method of thinning. The basic idea of this method is that under some conditions, there exists an embedded Poisson process in any point process such that all its arrival points form a subsequence of the Poisson process. The authors extend this result by showing that on the embedded Poisson process a Markov chain can be defined with a discrete state that characterizes the stage of the interarrival times. This implies that embedded Markov chains can be constructed with countable state spaces for the state processes of many practical systems that can be modeled by point processes. >

The perturbation analysis of open queuing networks is discussed. The concept of realization probability is extended to realization factors for open networks. A set of linear equations is derived for realization factors. It is shown that the perturbation analysis estimate of the sensitivity of a performance measure with respect to a mean service rate (or a mean interarrival rate) converges with probability one to the sensitivity of the steady-state performance measure, which simply equals the expected value of the realization factor. The results provide an analytical method of calculating performance sensitivity and form a theoretical foundation for perturbation analysis of open networks. >

We study the blind separation problem of non-Gaussian source signals when there is only one desired signal to be recovered from its instantaneous mixtures with another source signals. Two sets of equations are built, both of which can be solved to blindly extract one non-Gaussian source signal. When there are n source signals, the number of equations in each equation sets is 3(n-1) that is much less than that for the separation of all source signals. The contribution of this paper lies in that it develops a principle for the design of blind single source separation algorithm.

In order to clarify the frequency of p16INK4 gene inactivation and its relationship with retinoblastoma (Rb) gene expression in non-small cell lung cancer, in situ double hybridization was established with Bio-labelled Rb cDNA probe and Dig-lablled p16INK4 cDNA probe, and immunohistochemistry was carried out with polyclone rabbit antibodies to human p16INK4 and Rb protein. The results showed that positive hybridization of p16INK4 mRNA showed blue with the detecting system of alkiline phosphatase NBT/BCIP, positive hybridization of Rb mRNA showed red with the detecting system of HPR-AEC. The negative ratios of p16INK4 and Rb gene transcription were 22.6%(7/31) and 16.1%(5/31). The results of immunohistochemistry showed that the negative ratio of p16INK4 protein was 42%(13/31) with p16INK4 polyclone antibody, the negative ratio of pRb was 19.4%(6/31) with polyclone antibody. The data indicated that p16INK4 gene and Rb gene are synergistic in the progression of lung cancer, p16INK4 gene plays a significant role in the development of non-small cell lung cancer.

HIV Associated Dementia (HAD) and peripheral neuropathy result from HIV-1 infection and several parameters impact on their initiation and course. These parameters include properties of the virus such as sequence heterogeneity of the envelope protein and virus and host gene expression in infected and uninfected macrophages in HIV infected individuals. The infection of brain cells such as macrophage/microglia may influence the course and duration of HAD through the elaboration of toxic molecules and viral host by-products of infection. Drugs of abuse complicate our interpretation of the resulting pathologies and affect the molecular and biochemical processes involved in HIV-1 infection and its life cycle. Furthermore, abused drugs may modulate the biology and function of macrophage/microglia as well as other cells in brain. Total HIV-1 virus load in the brain may also impact the clinical consequences of infection. Although specific strains of HIV-1 may inflict HAD by interactions at the molecular level, other mechanisms may operate in the initiation and development of peripheral neuropathy. An important aspect of these studies is the determination of their accuracy, specificity, sensitivity, and reproducibility. We describe important caveats involved in the performance, analysis, and interpretation of the results.

Plasminogen activators (PA) elaborated by tumor cells play an important role in the complex process of tissue invasion and metastasis. In the present study the effect of the PA inhibitor type 2 (PAI-2) on tissue invasion in vitro and in vivo was investigated. Clones either expressing (B-) or not expressing the endogenous PAI-2 gene (C+) were isolated from the human HT1080 fibrosarcoma cell line and transfected with full-length PAI-2 cDNA. Recombinant PAI-2 (rPAI-2) expressed by these cells completely inhibited receptor-bound urokinase activity and partially neutralized secreted PA activity. Degradation of extracellular matrix proteins by these transfected cells was markedly decreased when compared to mock or untransfected control cells. The rPAI-2-expressing cells did not penetrate a multilayer of rat smooth muscle cells in vitro, which was readily invaded and destroyed by control cells. The PAI-2 transfectants remained tumorigenic in athymic/nude mice, but tumors originating from these cells showed the presence of a thick, collagenous capsule absent in tumors formed by control cells. Thus, expression of rPAI-2 in HT1080 cells resulted in neutralization of receptor-bound urokinase with subsequent inhibition of matrix protein degradation and invasion in vitro and induction of a thick, peritumoral capsule in vivo.

As cells progress through the multistep process of neoplastic transformation, they eventually acquire the property of invasive behavior. Although both plasminogen activators (PA) and their inhibitors (PAI) contribute to this process, their regulation in normal and transformed cells remains poorly defined. Because somatic cell hybrids provide useful tools for examining the transformation pathway, tumorigenic and invasive HeLa cells were fused with human normal vascular smooth muscle cells and tested for invasion-related parameters, including the expression of PA and PAI genes, and matrix degradation. Both parental cell lines produced large amounts of PAI activities with no detectable PA in either cellular or secreted form. Opposite findings were obtained with the hybrid cell lines, which demonstrated the presence of receptor-bound and secreted PA but absence of enzymatically measurable PAI activities. Both urokinase-type and tissue-type PA were found in cell-associated and secreted form in the hybrid cells. In addition, expression of the urokinase-type PA receptor gene was found in the three hybrid cells and the vascular smooth muscle cells but not in the HeLa cells. Expression of active, receptor-bound and secreted PA provided the nontumorigenic hybrid cells with the enzymatic tools to degrade extracellular proteins in a plasminogen-dependent manner. Thus, the hybrid cells lost tumorigenicity while retaining the tissue-degrading capability of HeLa cells. These hybrid cell lines should prove to be important reagents for investigating the complex regulatory control of PA and PAI gene expression.

Perturbation analysis of closed queuing networks with nonexponential service time distributions is considered. Perturbation analysis formulas using realization probabilities are extended to these networks. A perturbation generation function, which generalizes the perturbation generation rule, is defined; equations for realization probability and formulas for sensitivity of the system throughput with respect to service time distribution parameters are obtained. The results justify the application of perturbation analysis algorithms to networks with general service time distributions. >

For closed exponential queueing networks, the derivatives of performance measures with respect to a service rate can be expressed in terms of a realization factor which satisfies a set of linear equations. In this paper, the derivative of the performance measure is first analytically derived via realization factors for a two-server cyclic network and is then extended to networks with load-dependent servers. In particular, the derivative with respect to a service rate is shown to be a product of a positive term and a quantity whose sign only depends on other service rates of the network. The results have immediate applications to optimal control of queues. Examples from flow control and service rate control of queueing networks are discussed. >

Perturbation analysis is a new technique which yields the sensitivities of system performance measures with respect to parameters based on one sample path of a system. This paper provides some theoretical analysis for this method. A new notion, the realization probability of a perturbation in a closed queueing network, is studied. The elasticity of the expected throughput in a closed Jackson network with respect to the mean service times can be expressed in terms of the steady-state probabilities and realization probabilities in a very simple way. The elasticity of the throughput with respect to the mean service times when the service distributions are perturbed to non-exponential distributions can also be obtained using these realization probabilities. It is proved that the sample elasticity of the throughput obtained by perturbation analysis converges to the elasticity of the expected throughput in steady-state both in mean and with probability 1 as the number of customers served goes to This justifies the existing algorithms based on perturbation analysis which efficiently provide the estimates of elasticities in practice.