Energy Efficient Ant Colony Algorithms for Data Aggregation in Wireless Sensor Networks

In this paper, a family of ant colony algorithms called DAACA for data aggregation has been presented which contains three phases: the initialization, packet transmission and operations on pheromones. After initialization, each node estimates the remaining energy and the amount of pheromones to compute the probabilities used for dynamically selecting the next hop. After certain rounds of transmissions, the pheromones adjustment is performed periodically, which combines the advantages of both global and local pheromones adjustment for evaporating or depositing pheromones. Four different pheromones adjustment strategies are designed to achieve the global optimal network lifetime, namely Basic-DAACA, ES-DAACA, MM-DAACA and ACS-DAACA. Compared with some other data aggregation algorithms, DAACA shows higher superiority on average degree of nodes, energy efficiency, prolonging the network lifetime, computation complexity and success ratio of one hop transmission. At last we analyze the characteristic of DAACA in the aspects of robustness, fault tolerance and scalability.Comment: To appear in Journal of Computer and System Science

Maintaining CD4/CD8 ratio and Th1-CTL subsets of chimeric antigen receptor (CAR)-T cells in serum-free culture conditions

Chimeric antigen receptor (CAR) T cells therapy is a promising strategy that significantly controlled the progress of cancer diseases. CAR-T cells could kill cancer cells through cellular immune response; therefore, CD8+ cytotoxic T cells are critical for CAR-T cell therapy. However, recent papers reported that CD4+ T helper cells were important for the response and maintenance of CAR-T cells in vivo. Here, we developed a serum-free CAR-T cell preparation process that maintained the T cell population and controlled the T cell subsets. The CD4+ and CD8+ T cell population in CAR-T cells were maintained at averagely 59.4 % and 34.6%, and the major T cell subsets were Th1 cells and cytotoxic T lymphocytes (CTLs), implying the potentially high cellular immune response. To verifying whether the prepared CAR-T cells were exhausted, the expression of several immune checkpoint markers was determined. Of interest, only less than 20% of CAR-T cells at endpoint were PD-1+ or CTLA4+, but more than 40% of CAR-T cells at the endpoint were TIM-3+, implying most CAR-T cells were not exhausted. These CAR-T cells produced more than 1 ng/mL of IFN-γ in the response to the antigen. Altogether, CAR-T cells could be prepared in our serum-free process in the controlling of T cell subsets, leading to potential high therapeutic potency. Please click Additional Files below to see the full abstract

Room temperature gas sensing with a hybrid poly-Si/ZnO TFT cell

In this work, we study the capability of a novel poly-Si/Zno hybrid TFT cell in sensing NO2 gas. Fabrication and structural features of this cell are identical to that reported in one of our previous works [1] except that the IGZO TFT is replaced by a ZnO one. The equivalent circuit of the hybrid cell is shown in Fig. 1, in which the poly-Si TFT and ZnO TFT are employed as the amplifier and sensor, respectively. In the configuration, the top gate of the poly-Si TFT is electrically connected to the drain of the bottom-gated ZnO TFT, while the top surface of the ZnO channel is exposed to the environment for sensing purposes. For the electrical measurements conducted at room temperature, the current source (IIN) was set at 100 pA with a compliance VG of 2 V. Concentration of the NO2 gas in the ambient was varied from 0 ~100 ppm. Transfer characteristics of the cell are expressed by showing the drain current of the poly-Si TFT as a function of the back-gate bias (VBG) of the ZnO TFT. In the figure, we can see the I-V curves show a parallel and positive shift as the concentration of the NO2 gas is increased. Meanwhile, the transitions in the figure are steep with a slope of around -60 mV/dec whose absolute value is much smaller than the subthreshold slopes of the individual ZnO TFT (\u3e300 mV/dec). The finding provides good evidence showing the potential of this scheme in promoting measurement sensitivity compared with conventional oxide-semiconductor TFTs. The experimental results also show that UV irradiation can recover the characteristics. Please click Download on the upper right corner to see the full abstract

In vitro high expansion of chimeric antigen receptor (CAR)-T cells in serum-free process conditions

Manufacturing process is an important and complex factor for preparing chimeric antigen receptor (CAR) T cells for therapy. Although serum was widely applied in the culture or expansion of T cells, the quality of serum could be varied from batch to batch, leading to the variation of T cell expansion and quality. In addition, the safety of pathogens from serum and Chemistry, Manufacturing, and Control (CMC) were required to be considered. To overcome the disadvantages of serum application in T cell culture, serum-free and xeno-free culture conditions were required. We intended to develop a rapid serum-free culture condition for the expansion of immune T cells ex vivo. In our optimized serum-free condition, CAR-T cells could be expanded to about 100-200 times to the initial cell number after 6-day culture and the cell viability of all specimens was above 98%. Of interest, the percentage of CAR+ population in all specimens was increases, and the T cell pollutions could be maintained at averagely about 35-40% of CD8+ T cells and averagely about 50-55% of CD4+ T cells after culture. Taken together, our conditions could be applied in the expansion of CAR-T cells for cell therapy to support the minimum requirement of blood or cell samples from patients and to maintain the T cell population. Please click Additional Files below to see the full abstract

Paxillin facilitates timely neurite initiation on soft-substrate environments by interacting with the endocytic machinery.

Neurite initiation is the first step in neuronal development and occurs spontaneously in soft tissue environments. Although the mechanisms regulating the morphology of migratory cells on rigid substrates in cell culture are widely known, how soft environments modulate neurite initiation remains elusive. Using hydrogel cultures, pharmacologic inhibition, and genetic approaches, we reveal that paxillin-linked endocytosis and adhesion are components of a bistable switch controlling neurite initiation in a substrate modulus-dependent manner. On soft substrates, most paxillin binds to endocytic factors and facilitates vesicle invagination, elevating neuritogenic Rac1 activity and expression of genes encoding the endocytic machinery. By contrast, on rigid substrates, cells develop extensive adhesions, increase RhoA activity and sequester paxillin from the endocytic machinery, thereby delaying neurite initiation. Our results highlight paxillin as a core molecule in substrate modulus-controlled morphogenesis and define a mechanism whereby neuronal cells respond to environments exhibiting varying mechanical properties

Antagonism between abscisic acid and ethylene in Arabidopsis acts in parallel with the reciprocal regulation of their metabolism and signaling pathways

Although abscisic acid (ABA) and ethylene have antagonistic functions in the control of plant growth and development, including seed germination and early seedling development, it remains unknown whether a convergent point exists between these two signaling pathways or whether they operate in parallel in Arabidopsis thaliana. To elucidate this issue, four ethylene mutants, ctr1, ein2, ein3, and ein6, were crossed with aba2 (also known as gin1-3) to generate double mutants. Genetic epistasis analysis revealed that all of the resulting double mutants displayed aba2 mutant phenotypes with a small plant size and wiltiness when grown in soil or on agar plates. Further ethylene sensitivity or triple response analyses demonstrated that these double mutants also retained the ctr1 or ein mutant phenotypes, showing ethylene constitutive triple and insensitive responses, respectively. Our current data therefore demonstrate that ABA and ethylene act in parallel, at least in primary signal transduction pathways. Moreover, by microarray analysis we found that an ACC oxidase (ACO) was significantly upregulated in the aba2 mutant, whereas the 9-CIS-EPOXYCAROTENOID DIOXYGENASE 3 (NCED3) gene in ein2 was upregulated, and both the ABSCISIC ACID INSENSITIVE1 (ABI1) and cytochromeP450, family 707, subfamily A, polypeptide 2 (CYP707A2) genes in etr1-1 were downregulated. These data further suggest that ABA and ethylene may control the hormonal biosynthesis, catabolism, or signaling of each other to enhance their antagonistic effects upon seed germination and early seedling growth