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‘Structurally nanoengineered antimicrobial peptide polymers’ (SNAPPs), in the form of star-shaped peptide polymer nanoparticles, have been recently demonstrated as a new class of antimicrobial agents with superior in vitro and in vivo efficacy against Gram-negative pathogens, including multidrug-resistant species. Herein, we present a detailed bionano interaction study on SNAPPs by assessing their antimicrobial activities against several Gram-negative bacteria in complex biological matrices. Simulated body fluid and animal serum were used as test media to reveal factors that influence the antimicrobial efficacy of SNAPPs. With the exception of Acinetobacter baumannii, the presence of divalent cations at physiological concentrations reduced the antimicrobial efficacy of SNAPPs from minimum inhibitory concentrations (MICs) within the nanomolar range (40–300 nM) against Escherichia coli, Pseudomanas aeruginosa, and Klebsiella pneumoniaeto 0.6–4.7 μM. By using E. colias a representative bacterial species, we demonstrated that the reduction in activity was due to a decrease in the ability of SNAPPs to cause outer and inner membrane disruption. This effect could be reversed through coadministration with a chelating agent. Interestingly, the potency of SNAPPs against A. baumanniiwas retained even under high salt concentrations. The presence of serum proteins was also found to affect the interaction of SNAPPs with bacterial membranes, possibly through intermolecular binding. Collectively, this study highlights the need to consider the possible interactions of (bio)molecules present in vivo with any new antimicrobial agent under development. We also demonstrate that outer membrane disruption/destabilization is an important but hitherto under-recognized target for the antimicrobial action of peptide-based agents, such as antimicrobial peptides (AMPs). Overall, the findings presented herein could aid in the design of more efficient peptide-based antimicrobial agents with uncompromised potency even under physiological conditions.

Abstract: This paper discusses the weakly coupled nonlinear Schrödinger equations in the supercritical case. With the best constant of the Gagliardo-Nirenberg inequality, we derive a sufficient condition for the global existence of solutions; this condition is expressed in terms of stationary solutions (nonlinear ground state).

Taranabant is a highly selective and potent cannabinoid CB1receptor inverse agonist. We compared the pharmacological properties of taranabant with another inverse agonist, rimonabant, and determined the preclinical safety margins of taranabant. In vitro studies demonstrated that taranabant is ∼10‐fold more potent than rimonabant at the CB1receptor, and taranabant is more selective based on off‐target in vitro screening. In vivo efficacy studies demonstrated that taranabant is ∼10‐fold more potent than rimonabant in diet‐induced obese rats. In repeat‐dose toxicological studies, taranabant did not cause mortality in rodents and monkeys at exposure margins ≤6478 and 1922 times the estimated human exposure at 0.5 mg/day−1. Taranabant did not produce CNS signs, including seizures, when administered to monkeys for 1 year at 10 mg/kg−1day−1(highest dose tested chronically), corresponding to an exposure margin of 974 times. In contrast to primates, taranabant produced brief handling‐induced seizure‐like activity in rodents, species predisposed to handling‐induced seizures. Throughout the entire preclinical program, taranabant did not cause histopathological changes in the peripheral or central nervous system. In summary, the highly selective nature of taranabant is consistent with its generally favorable preclinical safety profile. Drug Dev Res 2009. © 2009 Wiley‐Liss, Inc.

A theoretical study of the hydraulic jump in a Bingham fluid is presented in this paper. Based on the approximation for lubrication theory, the formulae for conjugate depths, sequent bottom shear stress and critical depth are established. Due to the absence of an exact solution of the basic equations for conjugate depths, an analytical approximation has been developed. This formula is shown to provide good results, with a small error of less than 4%. The analytical results have revealed that the critical depth and the ratio of conjugate depths increase until the bottom shear stress reaches a certain value and decreases above that. Both the critical depth and the ratio of conjugate depths have maximum values where the critical flow or the jump is coupled between the effects of shear-free and shear regions. Reasonable agreement is achieved between the theoretical results and experimental data for conjugate and critical depths. The observation that the critical depth increases greatly when the dimensionless yield stress λ ≥ 0.1 in the experiment provides further justification for the theoretical approach

This paper describes a computing environment WBCSim that increases the productivity of wood scientists conducting research on wood-based composite materials and manufacturing processes. WBCSim integrates Fortran 90 simulation codes with a Web-based graphical front end, an optimization tool, and various visualization tools. WBCSim serves as an example for the design, construction, and evaluation of small-scale problem solving environments. WBCSim supports six models. A detailed description of the system architecture and a typical scenario of usage are presented, along with optimization and visualization features.This paper describes a computing environment WBCSim that increases the productivity of wood scientists conducting research on wood-based composite materials and manufacturing processes. WBCSim integrates Fortran 90 simulation codes with a Web-based graphical front end, an optimization tool, and various visualization tools. WBCSim serves as an example for the design, construction, and evaluation of small-scale problem solving environments. WBCSim supports six models. A detailed description of the system architecture and a typical scenario of usage are presented, along with optimization and visualization features.

In this paper, the capability of the CVD technique to produce uniform foams of different properties, with cell size ranging from ∼ 450 to ∼ 3200 μm, porosity from ∼ 70 to ∼ 98 %, and nominal thickness up to 3 mm is presented. In addition to the established application as a battery electrode material, some other potential capabilities and applications are explored.

In situ high-pressure synchrotron X-ray diffraction and infrared absorption experiments for gibbsite were performed at room temperature up to 53 and 25 GPa, respectively. A phase transition was confirmed at about 2.5 GPa. The high-pressure phase is indexed as an orthorhombic structure, rather than a triclinic structure as reported in previous studies. The compressibility of gibbsite and its high-pressure polymorph were studied, and their bulk moduli K 0 were determined to be 49 and 75 GPa, respectively with K 0' as 4. The in situ high-pressure infrared absorption spectra revealed the gradual disordering of hydrogen substructure above 15 GPa in quasihydrostatic compression.

Abstract:  Physical properties including the equation of state, elasticity, and shear strength of pyrite have been measured by a series of X-ray diffraction in diamond-anvil cells at pressures up to 50 GPa. A Birch–Murnaghan equation of state fit to the quasihydrostatic pressure–volume data obtained from laboratory X-ray source/film techniques yields a quasihydrostatic bulk modulus K 0T =133.5 (±5.2) GPa and bulk modulus first pressure derivative K ′ 0T =5.73 (±0.58). The apparent equation of state is found to be strongly dependent on the stress conditions in the sample. The stress dependency of the high-pressure properties is examined with anisotropic elasticity theory from subsequent measurements of energy-dispersive radial diffraction experiments in the diamond-anvil cell. The calculated values of K 0T depend largely upon the angle ψ between the diffracting plane normal and the maximum stress axis. The uniaxial stress component in the sample, t=σ3−σ1, varies with pressure as t=−3.11+0.43P between 10 and 30 GPa. The pressure derivatives of the elastic moduli dC 11/dP=5.76 (±0.15), dC 12/dP=1.41 (±0.11) and dC 44/dP=1.92 (±0.06) are obtained from the diffraction data assuming previously reported zero-pressure ultrasonic data (C 11=382 GPa, C 12=31 GPa, and C 44=109 GPa).

Combined one-color laser-photolysis/laser-induced fluorescence methods have been applied to photodissociate nitrobenzene (NB) molecules and to detect the resulting nitric oxide (NO) photofragments. A one-color laser is used to induce photodissociation and detection of NO via the A(v‘= 0)–X(v”= 0–4) transitions. A strongly wavelength-dependent signature is obtained due to the population of v”= 0–3 of NO. The ratios of the peak heights of the P12bandhead are (v”= 0):(v”= 1):(v”= 2):(v”= 3) = 1:0.3:0.1:0.02. A detection limit of ∼500 ppb by weight of NB in air at pressures of 10 and 100 Torr is achieved by monitoring NO X(v”= 2). This is the first attempt to use an excited NO vibrational level for NB detection, and the method can be extended to detection of other nitro compounds. It has the advantage that background of ambient ground-state NO is precluded.

Catalytic functions of Mo/HZSM-5 toward methane aromatization are examined under various activation and reaction conditions. Molybdenum ions are necessary in the activation of methane. High benzene yields of around 7% are obtained with a selectivity of more than 96% at 973 K over a 2 wt % Mo/HZSM-5 catalyst in a tubular reactor. Pretreatment with hydrogen is found to be beneficial to the initialization of aromatization. The aromatization activity increases upon decreasing the Si/Al ratio in HZSM-5, indicating an acidity dependence. This is supported by the fact that a Mo catalyst supported on cesium-exchanged ZSM-5 losses its catalytic aromatization activity at all. The effective coordination between molybdenum ion sites and Brønsted acid sites in the framework of ZSM-5 is important in the activation of the stable C−H bonds in methane and the eventual aromatization to form benzene. The constant O1s binding energy in the XPS spectra of both fresh and used catalysts suggests that coke formation does not occur on the SiO4 tetrahedra but rather on the molybdenum sites supported on the external surface of ZSM-5.

Abstract: A theoretical study is presented in this paper to investigate the conjugate heat transfer across a vertical finite wall separating two forced and free convection flows at different temperatures. It is assumed that the heat conduction in the wall is only in the transversal direction. We also assume that countercurrent boundary layers are formed on the both sides of the wall. The governing equations of this problem and their corresponding boundary conditions are all cast into a dimensionless form by using a non-similarity transformation. These resulting equations, which are singular at the points ξc=0 and 1, are solved numerically using a very efficient singular perturbation method. The effects of the resistance parameters and of the Prandtl numbers on heat transfer characteristics are investigated and presented in a table and ten figures.

The newly developed toroidal fluidized bed reactor has potential for improving sulfide roasting efficiency due to its unique and good mass/heat transfer characteristics. To achieve effective roasting at high temperature using the toroidal fluidized bed reactor, engineering issues associated with sintering and ferrite formation are investigated in this study by roasting industrial sulfide concentrates of zinc and copper. Laboratory tests are conducted at 800–1100°C by using an electric tube furnace under controlled roasting conditions. The test program is based on statistical design, and the products are characterized by XRD, SEM and EDX. It is revealed that the oxygen concentration plays an important role in promoting roasting. Roasting temperatures higher than 950°C do not favor roasting conversion due to the sintering of sulfide particles which inhibits oxygen diffusion into the particle core. Close contact of the oxidized particles favors the atomic interdiffusion between particles, leading to the formation of undesired zinc ferrite. Roasting in toroidal fluidized bed reactor results in zinc calcines with increased surface area and reduced zinc ferrite formation, thus improving zinc recovery.

A study was designed to determine the effect of the consumption of the nutritive sweetener aspartame on non-insulin-dependent diabetics. Forty-three adult diabetics between the ages of 21 and 70 completed a 90-day study; all were diabetics whose conditions were managed by diet and/or hypoglycemic agents. Participants in the blind study were instructed to continue their usual diet and to take two capsules of an assigned preparation three times daily with meals, either the aspartame or the placebo. The 1.8 g of aspartame administered is approximately three times the expected daily consumption of aspartame if used as a sweetener to replace sugar. Throughout the study subjects were examined for (1) symptoms of intolerance, (2) fasting plasma phenylalanine levels exceeding 4 mg/100 ml, and (3) deterioration of diabetic control. At the conclusion of the study subjects exhibited no symptoms that could be traced to the administration of aspartame or the placebo, and diabetic control was unaffected by the chronic administration of these substances. Aspartame seems to be well tolerated by non-insulin-dependent diabetics.

The possibility of multiple steady-states and their prediction in chemical reactors was established by the pioneering work of Amundson and colleagues. This paper reports on a heretofore unknown type of multiple steady-state in a chemostat (CFSTR) with a pure culture of E. coli B/r growing under ammonium limitation. Two steady-states at dilution rate (0.91 hr-1) near the maximum growth rate (0.94 hr-1) result in residual concentrations of ammonium ion of ca. 40 mg/L and 1.5 mg/L. Dilution rate is the reciprocal of holding time. Models of single cells of E. coli can be used to predict the existence of such multiple steady-states. Ammonium uptake and assimilation both can occur via parallel pathways. The presence of the parallel pathways admits the possibility of this type of multiplicity. The parameters of the ammonium transport mechanism are crucial in allowing multiple steady-states. The model predicts specific growth rates higher than observed in batch culture for the chemostat low residual ammonium steady-state. Data consistent with the prediction of increased maximum specific growth rates is presented.

Prostaglandin A2 (PGA2) reversibly blocked the cell cycle progression of NIH 3T3 cells at G1 and G2/M phase. When it was applied to cells synchronized in G0 or S phase, cells were blocked at G1 and G2/M, respectively. The G2/M blockage was transient. Microinjected oncogenic leucine 61 Ras protein could not override the PGA2 induced G1 blockage, nor could previous transformation with the v-raf oncogene. The serum-induced activation of mitogen-activated protein kinase was not inhibited by PGA2 treatment. These data suggest that PGA2 blocks cell cycle progression without interfering with the cytosolic proliferative signaling pathway. Combined microinjection of E2F-1 and DP-1 proteins or microinjected adenovirus E1A protein, however, could induce S phase in cells arrested in G1 by PGA2, indicating that PGA2 does not directly inhibit the process of DNA synthesis. In quiescent cells, PGA2 blocked the normal hyperphosphorylation of the retinoblastoma susceptible gene product and the activation of cyclin-dependent kinase (CDK) 2 and CDK4, in response to serum stimulation. PGA2 treatment elevated the p21Waf1/Cip1/Sdi1 protein expression level. These data indicate that PGA2 may arrest the cell cycle in G1 by interfering with the activation of G1 phase CDKs.

In this work, methane conversion was carried out over a group VIII metal in a Pd−Ag membrane reactor to produce hydrogen and higher hydrocarbons in a nonoxidative atmosphere. A two-step reaction sequence operated at two different temperatures was adopted to pass around the thermodynamic barrier of low-temperature methane conversion. Methane was first activated as a result of the dissociative deposition over a Ru catalyst, followed by rehydrogenation to form higher hydrocarbons. The use of the Pd−Ag membrane reactor significantly enhanced the methane conversion into hydrogen and carbonaceous species in the first step and the yield of higher hydrocarbons upon rehydrogenation in the second step. The repartition of different carbonaceous species was monitored by temperature-programed surface reaction (TPSR). The effective methane conversion at low temperatures in the membrane reactor favored the formation of Cα species which were selective to produce higher hydrocarbons. A C2+ yield of about 16% was obtained by conducting methane decomposition at 300 °C and rehydrogenation at 100−120 °C in the Pd−Ag membrane reactor.

While there is considerable structural evidence that insulin-like growth factors (IGFs) share a long evolutionary history, little is known about the conservation of IGF function. In order to address this, we have made recombinant hagfish IGF, hence allowing characterization of an IGF from a representative of the primitive vertebrate class, Agnatha. The production of recombinant hagfish IGF has been complicated by a number of factors including the requirement of a longer leader peptide for fusion protein expression, reduced solubility of the protein, as well as problems in the refolding procedure. However, we were able to produce a small quantity of hagfish IGF with an N-terminal glycine addition which is biologically active. Furthermore, N-terminal amino acid sequencing and mass spectrometry confirm that we have produced hagfish IGF.In vitroassessment of recombinant hagfish IGF in cultured cells indicates that hagfish IGF indeed shares functional properties with mammalian IGFs. Thus, hagfish IGF stimulates protein synthesis in rat myoblasts, but 20- and 5-fold more peptide, respectively, is required to achieve the same half-maximal responses as with human IGF-I (hIGF-I) or IGF-II (hIGF-II). Hagfish IGF also competes for binding to the type-1 IGF receptor present both on rat myoblasts and on salmon embryo fibroblasts, though with somewhat lower affinity than either hIGF-I or hIGF-II. However, studies investigating binding to the IGF-II-specific type-2 receptor suggest that hagfish IGF may in fact be more closely related to IGF-I than to IGF-II. These results indicate that motifs important for functions associated with mammalian IGFs appear to have evolved prior to the Agnathans diverging from the main line of vertebrate evolution 550 million years ago. Accordingly, we now have functional as well as structural evidence that the IGFs have a long evolutionary history.

The microbuckling strength of long fibre–polymer matrix composites under multiaxial in–plane loading is analysed using a finite element code. Cosserat couple stress theory is used to include the role of fibre bending resistance, with the fibre diameter setting the internal length scale of the constitutive law. The matrix is treated as a dilatant nonlinear elastic–plastic solid. Microbuckling is assumed to nucleate from an elliptical region of initial fibre waviness. Both in–plane shear stress and transverse stress significantly knock–down the axial compressive strength. The compressive strength is found to be sensitive to both the magnitude of the fibre waviness and to the physical size of the region of waviness in relation to the fibre diameter d. The dominant geometrical feature is the length of the initial imperfection in the transverse direction: the collapse strength exceeds the infinite band prediction by less than 20 per cent when exceeds about 200 fibre diameters.

Although electroless copper deposition has been widely used in the electronic industry, the selection of the bath solutions relies still on some empirical rules. This paper provides a further exploration of the bath compositions for electroless copper plating. It was found that the formation of Cu2O in electroless copper plating is associated with the presence of Cu(OH)2 in the bath. A chemical equilibrium calculation was thus made for the avoidance of Cu(OH)2 in an electroless copper bath. Sodium thiosulfate was found to be an effective stabilizer for electroless copper plating. The plating was further optimized based on a statistical design of sorts, namely, Taguchi's approach. Effects of individual components on the plating rate were discussed.

The rapid development of catalytic membrane reactors requires materials with a higher permeability and a better mechanical stability than the current thick membranes. Pd-based composite membranes supported on porous stainless steel offer such an alternative. However, commercially available porous stainless steel materials have to be further worked to reduce the surface pore sizes and ensure the formation of thin Pd films in an impervious form. In this work, a shot peening treatment was performed on the surface of a porous stainless steel to modify its surface pore size. Substrates with effectively reduced surface pore sizes were obtained under mild peening conditions. The permeation behavior of the substrates was examined using argon as the permeation gas. Impervious thin palladium films were deposited on the modified porous substrate surface by electroless plating. Hydrogen permeability through the resulting membranes was found to be comparable to that of pure palladium sheets, while the permeation flux was significantly enhanced due to the use of the thin Pd membrane.

Vacuolar H+-pyrophosphatase (H+-PPase) from etiolated hypocotyls of mung bean (Vigna radiata L.) is a homodimer with a molecular mass of 145 kDa. The vacuolar H+-PPase was subjected to high hydrostatic pressure to investigate its structure and function. The inhibition of H+-PPase activity by high hydrostatic pressure has a pressure-, time- and protein-concentration-dependent manner. The Vmax value of vacuolar H+-PPase was dramatically decreased by pressurization from 293.9 to 70.2 µmol of PPi (pyrophosphate) consumed/h per mg of protein, while the Km value decreased from 0.35 to 0.08 mM, implying that the pressure treatment increased the affinity of PPi to vacuolar H+-PPase but decreased its hydrolysis. The physiological substrate and its analogues enhance high pressure inhibition of vacuolar H+-PPase. The HPLC profile reveals high pressure treatment of H+-PPase provokes the subunit dissociation from an active into inactive form. High hydrostatic pressure also induces the conformational change of vacuolar H+-PPase as determined by spectroscopic techniques. Our results indicate the importance of protein–protein interaction for this novel proton-translocating enzyme. Working models are proposed to interpret the pressure inactivation of vacuolar H+-PPase. We also suggest that association of identical subunits of vacuolar H+-PPase is not random but proceeds in a specific manner.

An attempt was made in this study to prepare very thin palladium membranes. Pdwas electrolessly deposited on the inner side surface of a mesoporous ceramic tube using a peristaltic pump to circulate the electroless solution through the tube. To obtain defect‐free Pdmembranes, a two‐step deposition procedure from a dilute Pd2+bath and a concentrated Pd2+bath was practised with great care to avoid the difficulties associated with the mismatch of thermal expansion coefficients between Pdand the ceramic substrate. The various membranes produced were characterized through a study of their permeation behaviors. A dense Pdmembrane about 2 μm thick was permselective to hydrogen. It was found that in this very thin Pdmembrane case, the hydrogen permeation flux was better correlated to hydrogen pressure using a power higher than 0.5, showing deviation from Sieverts' law. To evaluate the efficiency of the prepared thin Pd/ceramic membranes, iso‐butane dehydrogenation was used as a model reaction. Enhanced dehydrogenation yields were obtained in the membrane reactor due to the separation of hydrogen from the reaction medium.

In cabbage (Brassica oleracea var. capitata) and Chinese kale (B. oleracea alboglabra) four types of N-bands can be distinguished: pericentromeric, telomeric (terminal), intercalary and satellite bands. Typical NOR bands were not observed. The pericentromeric bands appear at the pericentric regions, possibly even at the centromeres of all chromosomes. Telomeric bands are observed on the short arms of chromosomes 1,5 and 6 in cabbage and chromosomes 1 and 5 in Chinese kale. Intercalary bands stained weakly in the long arms of chromosome 3 in cabbage and chromosome 2 in Chinese kale. Satellite bands cover the entire satellites in both Brassica species. The N-banding pattern is very similar in appearance to the C-banding pattern in both species and much more convenient to apply.

Abstracts are not published in this journal

A pulsed dc electric discharge in a pulsed supersonic beam has been used as an efficient source of producing radicals. The (2+1) REMPI spectra of the SF2 radicals were investigated between 245 and 365 nm (54945−81630 cm^-1 ). Eight electronic band systems have been observed in this range. One series with quantum defect δ = 1.961(6) is comprised of the &Btilde; ¹B1(4s) and &Jtilde; ¹B1(5s) Rydberg states which have origins at ν0-0 = 54470 and 68951 cm^-1, respectively. Vibrational analyses of these Rydberg states showed that in the &Btilde; ¹B1(4s) state ω1‘(a1 sym str) = 981(23) cm^-1 and in the &Jtilde; ¹B1(5s) state ω1‘(a1 sym str) = 942(3) cm^-1. A second Rydberg series &Etilde; (4p) with quantum defect δ = 1.61 is characterized with the spectroscopic values ν0-0 = 62025 cm^-1, ω1‘(a1 sym str) = 941(27) cm^-1, and ω2‘(a1, bend) = 413(12) cm^-1. Incompletely rotational analysis revealed that the &Ftilde; electronic state with ν0-0 = 63812 cm^-1, ω1‘(a1 sym str) = 966(6) cm^-1, and ω2‘(a1, bend) = 417(23) cm^-1 merges with the vibrational progression of the &Etilde; (4p) state. The &Ftilde; state might be a 4p Rydberg state of another hybrid symmetry with the quantum defect δ = 1.50. A third Rydberg series is comprised of the &Gtilde; (3d) (ν0-0 = 68378 cm^-1, ω1‘ = 939(12) cm^-1, δ = 0.086), the &Htilde; (3d) (ν0-0 = 68571 cm^-1, ω1‘ = 936(4) cm^-1, δ = 0.064), and the Ĩ (3d) (ν0-0 = 68847 cm^-1, ω1‘ = 933(4) cm^-1, δ = 0.032). In addition, two valence states labeled as the &Btilde;‘ state (38623 cm^-1) and &Ctilde; state (56219−61278 cm^-1) were also observed. A fit of the Rydberg formula to the ns(¹B1) (n = 4,5) origins found the adiabatic ionization potential of SF2 radicals to be IPa = 10.021(1) eV.