Ultradrawing properties of ultrahigh‐molecular weight polyethylene/functionalized carbon nanotube fibers and transmittance properties of their gel solutions

The influences of the dispersion level of carbon nanotubes (CNTs) and functionalized CNTs on the transmittance properties of ultrahigh‐molecular weight polyethylene (UHMWPE) gel solutions and on ultradrawing properties of their as‐prepared fibers are reported. The transmittance properties suggest that the dispersion level of functionalized CNTs in UHMWPE/functionalized CNTs gel solution is significantly better than plain CNTs in UHMWPE/CNTs gel solutions. The orientation factors, achievable draw ratios, tensile strength (σ_f), and modulus (E) values of UHMWPE/CNTs (F_xC_y) and UHMWPE/functionalized CNTs (F_xC_f‐y) as‐prepared fiber specimens reached a maximum value as their CNT and functionalized CNT contents approached optimum contents at 0.00015 and 0.0001 wt%, respectively. The σ_f and E values of both F_xC_0.0012 and F_xC_f‐0.001 series fiber specimens prepared at their optimum CNT and functionalized CNT contents reached another maximum as their UHMWPE approached optimum UHMWPE concentration of 1.7 wt%. Possible reasons accounting for these interesting properties are proposed. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers     

Multi-objective inventory control using electromagnetism-like meta-heuristic

Most of the works on multi-objective inventory control unify the various objectives into a single objective such that lead to a compromise solution whose non-dominance is not guaranteed. This paper presents an algorithm based on Electromagnetism-like Mechanism (EM) to solve a multi-objective inventory control problem with cost and shortage minimization objectives. EM is a new meta-heuristic originated from the electromagnetism theory in physics; it simulates attraction and repulsion of charged particles in order to move towards the optimum. A framework, so called Multi-Objective EM (MOEM), is proposed to approximate the well-known efficient solutions of order size and safety stock without using any surrogate measure (e.g. service level or shortage cost) and prior preference information from decision-makers. To give a specific compromise solution, any outranking method can be implemented to prioritize the non-dominated solutions for decision-makers. Finally, this could be the first attempt to apply EM to multi-objective inventory control, even the inventory control problems.     

Structural optimization affording 2-(R)-(1-(R)-3, 5-bis(trifluoromethyl)phenylethoxy)-3-(S)-(4-fluoro)phenyl-4- (3-oxo-1,2,4-triazol-5-yl)methylmorpholine, a potent, orally active, long-acting morpholine acetal human NK-1 receptor antagonist

Structural modifications requiring novel synthetic chemistry were made to the morpholine acetal human neurokinin-1 (hNK-1) receptor antagonist 4, and this resulted in the discovery of 2-(R)-(1-(R)-3, 5-bis(trifluoromethyl)phenylethoxy)-3-(S)-(4-fluoro)phenyl-4-(3-ox o-1 ,2,4-triazol-5-yl)methyl morpholine (17). This modified compound is a potent, long-acting hNK-1 receptor antagonist as evidenced by its ability to displace [125I]Substance P from hNK-1 receptors stably expressed in CHO cells (IC50 = 0.09 +/- 0.06 nM) and by the measurement of the rates of association (k1 = 2.8 +/- 1.1 x 10(8) M-1 min-1) and dissociation (k-1 = 0.0054 +/- 0.003 min-1) of 17 from hNK-1 expressed in Sf9 membranes which yields Kd = 19 +/- 12 pM and a t1/2 for receptor occupancy equal to 154 +/- 75 min. Inflammation in the guinea pig induced by a resiniferatoxin challenge (with NK-1 receptor activation mediating the subsequent increase in vascular permeability) is inhibited in a dose-dependent manner by the oral preadmininstration of 17 (IC50 (1 h) = 0.008 mg/kg; IC90 (24 h) = 1.8 mg/kg), indicating that this compound has good oral bioavailbility and peripheral duration of action. Central hNK-1 receptor stimulation is also inhibited by the systemic preadministration of 17 as shown by its ability to block an NK-1 agonist-induced foot tapping response in gerbils (IC50 (4 h) = 0.04 +/- 0.006 mg/kg; IC50 (24 h) = 0.33 +/- 0.017 mg/kg) and by its antiemetic actions in the ferret against cisplatin challenge. The activity of 17 at extended time points in these preclinical animal models sets it apart from earlier morpholine antagonists (such as 4), and the piperidine antagonists 2 and 3 and could prove to be an advantage in the treatment of chronic disorders related to the actions of Substance P. In part on the basis of these data, 17 has been identified as a potential clinical candidate for the treatment of peripheral pain, migraine, chemotherapy-induced emesis, and various psychiatric disorders.     

Dissociation of chemotaxis from agonist-induced receptor internalization in a lymphocyte cell line transfected with CCR2B. Evidence that directed migration does not require rapid modulation of signaling at the receptor level

To investigate the role of the carboxyl-terminal region (52 amino acids) of the monocyte chemoattractant protein 1 receptor (CCR2B) in chemotaxis, we created a series of mutants and expressed them in a murine pre-B lymphocyte cell line. Truncation of the cytoplasmic carboxyl tail to 20 amino acids had little or no effect on chemotaxis or signal transduction, but further truncation resulted in marked functional defects. Upon incubation with monocyte chemoattractant protein 1, CCR2B underwent rapid and extensive internalization, and this was impaired progressively as the carboxyl tail was truncated from 52 to 8 amino acids. Mutation of all of the serine and threonine residues in the carboxyl tail to alanine also resulted in markedly impaired receptor internalization but did not affect signaling or chemotaxis. We conclude that the membrane-proximal portion of the cytoplasmic carboxyl tail of CCR2B is critically involved in chemotaxis and signal transduction, but neither phosphorylation of carboxyl serines or threonines nor internalization of the receptor is required for robust chemotaxis.     

The design and simulation of a novel out-of-plane micro electrostatic actuator

This paper presents a mechanism of developing a novel out-of-plane micro electrostatic actuator capable of causing large out-of-plane deflection. The performance of the actuator is evaluated and simulated by MEMCAD software. Initial analysis results indicated that the usage of both the novel U-shape suspension beam and the electrostatic actuation mechanism permit large rotations motion with respect to the increment of the numbers of electrodes. Moreover, stable rotational motion can be achieved by varying the dimensions of electrode and gap spacing. This design advantage brings the possibility of developing other three-dimensional (3D) structures for on and/or out-of-wafer applications such as optical switch or display.     

Distribution of 127 edible plant species for antioxidant activities by two assays

Epidemiological studies have demonstrated the protective effects of fruit and vegetable consumption on human health. A total of 150 edible plants representing 127 species were evaluated for Trolox equivalent antioxidant capacity (TEAC) and superoxide scavenging (SOS) activity. Distributions of vegetables for TEAC and SOS were not continuous but highly skewed. TEAC values on a dry weight basis ranged from 0 to 2105 µmol TE g⁻¹ and SOS values ranged from 0 to 6206 µmol ascorbate equivalent (AE) g⁻¹. The majority of vegetables clustered within 200 µmol TE g⁻¹ and 400 µmol AE g⁻¹. Vegetable species were grouped into six classes after natural logarithm transformation of TEAC and SOS values. Most highly consumed vegetables fell in the very low to medium classes. Species in the very high class for both TEAC and SOS included leaves of Cedrela sinensis (Chinese cedar), Oroxylum indicum (Damocles tree), Cassia siamea (cassod tree) and Cassia tora (sickle senna). Edible plants high in antioxidant activity (AOA) were mostly perennial and underutilised crops, while commonly consumed vegetables were generally low in AOA. There is great potential to increase dietary antioxidants and improve human health through consumption of diverse vegetable species, especially those high in AOA. Copyright © 2006 Society of Chemical Industry     

Calculation of the fundamental mode sizes in optical channelwaveguides using Gaussian quadrature

A fast numerical method using Gaussian quadrature, which takes only seconds on a microcomputer, is presented for calculating the fundamental mode sizes in optical channel waveguides. Variational expressions for the square of the propagation constant, β² , of the TE- and TM-like modes are derived using the vector wave equations. For channel waveguides with gradual refractive index distributions, these expressions approach the variational expression obtained using the scalar wave equation. To show the usefulness of the numerical technique the authors present the results for titanium indiffused lithium niobate channel waveguide which are commonly used in integrated optical circuits. Since these waveguides have gradual refractive index distributions, both types of expressions give the same results; however, it takes less time to compute the mode sizes when using the variational expression obtained from the scalar wave equation. The authors find the calculated mode sizes are in good agreement with published measurements. From the comparison process, best fit parameters are obtained, which give mode sizes close to the values published in the literature. For one special case the authors are able to obtain an analytical variational expression and they use it to test the accuracy of the numerical method. They find that the values of β² given by both methods agree to six significant figures     

Prognostic features and treatment outcome in locoregionally advanced nasopharyngeal carcinoma following concurrent chemotherapy and radiotherapy

PURPOSE: Concurrent chemotherapy and radiotherapy (CCRT) are effective in treatment of locoregionally advanced nasopharyngeal carcinoma (NPC). However, the prognostic factors after CCRT have not been evaluated. We therefore attempt to evaluate factors that influence treatment outcomes following CCRT. METHODS AND MATERIALS: Seventy-four (5 in stage III and 69 in stage IV) patients with locoregionally advanced NPC were treated with CCRT. Radiotherapy was delivered either at 2 Gray (Gy) per fraction per day up to 70 Gy or 1.2 Gy, 2 fractions per day, up to 74.4 Gy. Concurrent chemotherapy consisted of cisplatin and 5-fluorouracil. Cox proportional-hazards model was used to analyze the prognostic factors which included age, gender, pathologic type, T, N, lactate dehydrogenase (LDH), and infiltration of the clivus. RESULTS: The primary tumor control rate at 3 years was 96.7% (95% confidence interval [CI]: 92.5-100), distant metastasis-free survival 81.1% (95% CI: 70.6-91.6), disease-free survival 77.0% (95% CI: 65.3-88.7), and overall survival 79.8% (95% CI: 69.2-90.4) with a median follow-up interval of 29 months (range 15-74 months). Cox proportional-hazards model revealed that infiltration of the clivus and serum level of LDH before treatment were the most two important factors that predict distant metastases. Infiltration of the clivus and the serum LDH level greater than 410 U/L were strongly associated with distant metastasis-free survival (p = 0.0004 and p = 0.0002, respectively). When these two risk factors were considered together, no distant metastasis was observed in 40 patients with both intact clivus and LDH < or = 410 U/L. On the contrary, 13 of the remaining 34 patients with at least one risk factor developed distant metastasis (p = 0.0001). CONCLUSION: Our study demonstrates that CCRT can improve the primary tumor control of 96.7% and disease-free survival of 77.0% at 3-year follow-up. Distant metastasis, however, is the major cause of failure. Infiltration of the clivus by the tumor and LDH greater than 410 U/L are the two independent and useful prognostic factors in patients with locoregionally advanced NPC who were treated with CCRT. Good- and poor-risk patients can be distinguished by virtue of their having both conditions.     

Intact capture of hypervelocity projectiles

The ability to capture projectiles intact at hypervelocities opens new applications in science and technology that would either not be possible or would be very costly by other means. This capability has been demonstrated in the laboratory for aluminum projectiles of 1.6 mm diameter, captured at 6 km/s, in one unmelted piece, and retaining up to 95% of the original mass. Furthermore, capture was accomplished passively using microcellular underdense polymer foam. Another advantage of capturing projectiles in an underdense medium is the ability of such a medium to preserve a record of the projectile's original velocity components of speed and direction. A survey of these experimental results is described in terms of a dozen parameters which characterize the amount of capture and the effect on the projectile due to different capture media.     

Characterization of transport properties in gas diffusion layers for proton exchange membrane fuel cells: 2. Absolute permeability

This is the second in a series of papers in which we present methods demonstrated in our group for the estimation of transport properties in gas diffusion layers (GDLs) for proton exchange membrane fuel cells (PEMFCs). Here we describe a method for determining separately the in-plane (x, y-directions) and through-plane (z-direction), viscous and inertial permeability coefficients of macro-porous substrates and micro-porous layers by controlling the direction of the gas flow through the porous sample. The method is applied initially to the macro-porous substrate of the GDL alone and subsequently to the macro-porous substrate with different micro-porous layers applied on it. The permeability coefficients of the micro-porous layer are calculated from the two measurements. The permeability coefficients are calculated from the Darcy–Forchheimer equation by application of the method of least squares. The method was applied to GDLs having different contents of polytetrafluoroethylene (PTFE) and carbon types. The samples with a higher PTFE content have in-plane and through-plane viscous permeability coefficients higher than those of the samples with lower PTFE content. The in-plane and through-plane viscous permeability coefficients also depend on the carbon type.