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The Poisson–Boltzmann equation (P-B) is used as an analytic model in a wide variety of fields in chemistry and physics, because it describes the charge distribution in a solute. Being highly nonlinear, there are only a few known solutions for simple boundary geometries and, beyond, iterative numerical schemes are often employed. This study, on the other hand, presents a systematic perturbation solution of the P-B using a non-dimensional electrokinetic–thermal energy ratio λ which, when it approaches zero, reduces the P-B to the Debye–Huckel approximation. Perturbation-series solutions are obtained for five basic examples, and lead to the surprising result that, even when λ is as large as 3 or larger, the perturbation solution is very accurate with only a few terms included in the series. This is because the perturbation analysis generates very rapidly vanishing coefficients at higher-order approximations. This result has the important implication that the perturbation method presented in this study could be applied quite generally for investigating more complicated problems.

The effect of solid solution treatment at temperature of 415oC and different holding time prior aging at 168oC for 16 hours on the mechanical properties and microstructure of AZ81-4Gd magnesium alloy were analyzed by X-ray and SEM. The results demonstrated that with increasing the solid solution time the primary β-Mg17Al12 phase dissolve in the matrix eventually. While the holding time increases to 20 hrs, the primary β-Mg17Al12 phase was completely vanished, but Al2Gd phase kept unchanged with increasing the holding time. In the mean while, the volume fraction of the β-Mg17Al12 phase precipitated during aging increased at first with increasing the holding time then decreased. Moreover, subgrains and twins began to form within the α grain matrix when the solid solution time increased to 12hrs, and the subgains parallele with each other or in the shape of oval. Increasing the solid solution time to 20 hrs the microstructure change dramatically and consist of very fine recrystallized α grains. Futher increasing the holding time the recrystallized grain size increased accordingly. The mechanical properties testing results showed that when the solid solution time increased to 24 hrs the ultimate tensile strength of AZ81-4Gd magnesium alloy was 270 MPa and the elongation was 11.6% respectively.

A steady directional EOF due to a nonlinear interaction between oscillatory axial electrical fields and oscillatory wall potentials (zeta potentials) is presented. This is a new mechanism to produce such a mean flow. It is found that the flow velocity depends not on the external driving frequency but on the phase angle difference between the electric fields and the zeta potentials. The formulation can also be reduced to the static EOF straightforwardly. For the purpose of theoretical demonstration, we use the Debye-Huckel approximation for the zeta potential. Results of planar and cylindrical capillaries are given.

The initial electroosmotic flow through a small pore or microchannel with annular or rectangular cross section is studied under the Debye-Hückel approximation. Analytical series solutions and their asymptotic behavior for small and large non-dimensional electrokinetic widths are found for these two basic cases. The explicit and accurate solutions are particularly useful for examining various geometric/physical effects on the transient time scales and the flow rates for the transient states. The steady flow rate of the smaller channel may be disproportionately smaller than a reference channel if the electric double layer is thick, but will be in close proportion to the area ratio if the electric double layer is thin. A smaller channel compared to a reference channel has a shorter transient time scale, and the transient flow has characters very different from the steady state if the electric double layer is thin. The total transient flow rate of several smaller pores or channels may exceed largely that of a single large pore or channel with the same total cross section on the transient time scale of the smaller channels. The results have important implications on liquid transport in micropores or channels by pulse voltages or more general time-varying voltages.

An efficient Ritz method is developed from the variational principle to solve the Poisson-Boltzmann equation under the Debye-Hückel approximation for studying the EOF in microchannels. The method is applied to the family of superelliptic cross sections which includes the elliptic channel and the rectangular channel as limiting cases. Several accurate tables presented are useful for design of electroosmotic channels, especially rectangular channels with rounded corners. It is shown how the flow rate Q is a sophisticated consequence of the nondimensional electrokinetic width K, the aspect ratio b as well as the superelliptic exponent n.

Totally strain-controlled low cycle fatigue tests with a strain ratio Rε= -1 were carried out on die-cast AZ91HP, AM50HP and AE 42 alloys at a constant strain rate of 2.5×10-3 s-1 and room temperature. The cyclic deformation behavior of the three alloys was investigated through the characteristics of representative hysteresis loops at various total strain amplitudes. Cyclic deformation hardening was observed and the low-cycle fatigue life data were analyzed using the well known Basquin and Coffin-Manson equations. The transition life of the three alloys is considerably low, which can be attributed to the low ductility of these die cast Mg alloys.

The association between the G894T polymorphism (Glu298Asp) of nitric oxide synthase 3 (NOS3) and risk of Alzheimer’s disease (AD) was explored by performing a meta-analysis of case-control studies. Bibliographical searches were conducted in the MEDLINE, EMBASE and China National Knowledge Infrastructure (CNKI) databases without any language limitations. Two investigators independently assessed abstracts for relevant studies and reviewed all eligible studies. We adopted regrouping in accordance with the most probably appropriate genetic model. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of this association. We performed a meta-analysis including 21 published articles with 23 case-control studies (5,670 cases and 5,046 controls). In the analyses, we found significant association between G894T polymorphism and AD risk under a complete overdominant model (GG + TT vs. GT) (OR = 1.18; 95%CI, 1.04–1.35; P = 0.010). When stratified by time of AD onset, we found the association between this polymorphism and AD susceptibility to be more substantial among late onset patients than among early onset patients (OR for late vs. early onset: 1.33 vs. 1.02, P interaction = 0.049). The meta-analysis showed that the polymorphism G894T of NOS3 was associated with risk of AD.

AIMS: Alzheimer's disease (AD) is a multifactor disease that has been reported to have a close association with type 2 diabetes (T2D) where the v‐akt murine thymoma viral oncogene homolog 1 (AKT1) plays an important role in the protein synthesis pathways and cell apoptosis processes. Evidence has been shown that AKT1 protein may be related to AD risk among patients with T2D. The aim of this study was to analyze the potential association between single nucleotide polymorphisms of AKT1 promoter and the risk of AD among patients with T2D. METHODS: The association between AKT1 polymorphisms and AD risk in patients with T2D was assessed among 574 consecutive unrelated subjects including 112 AD patients with T2D, 231 patients with AD, and 231 healthy controls in a case–control study. The cognitive function of all subjects was assessed using MMSE. Six single nucleotide polymorphisms with minor allele frequency >0.2 (rs2498786, rs74090038, rs2494750, rs2494751, rs5811155, and rs2494752) in AKT1 promoter were analyzed by polymerase chain reaction (PCR), and the concentration of AKT1 protein in serum was tested using enzyme‐linked immunosorbent assay (ELISA). RESULTS: Overall, there was statistically significant difference in AKT1 rs2498786 polymorphism. The CC frequency of AKT1 rs2498786 polymorphism in AD with T2D group and AD control group was significantly higher than that in healthy control group (P (AD+T2D vs. health)

Evidence has been obtained showing that endoplasmic reticulum (ER) stress is closely associated with the development of type 2 diabetes (T2D) and that the human X box binding protein 1 (XBP1) is an important transcription factor involved in the development of ER stress. The study aimed to analyze the potential association between polymorphism -116C/G of XBP1 and the risk of T2D. The association between XBP1 polymorphism -116C/G and T2D risk was assessed among 1058 consecutive unrelated subjects, including 523 T2D patients and 535 healthy controls, in a case control study. The -116GG genotype and -116G allele were more frequent in T2D subjects compared with control subjects by statistical analysis, showing that the -116GG homozygote polymorphism of XBP1 might lead to increased susceptibility to T2D in a Chinese Han population. T2D subjects with the -116GG genotype had higher fasting plasma glucose levels, fasting insulin levels, and HbA1c and worse HOMA-IR than the T2D subjects with -116CG and -116CC genotypes (P0.0001). The study supports a role for -116C/G polymorphism of the XBP1 promoter in the pathogenesis of T2D in a Chinese Han population, and more studies are needed to further evaluate our results.

In a paper published in the JFE in 2013, we provided evidence that market participants perceive staggered boards to be on average value-reducing. In a recent response paper, Amihud and Stoyanov (2015) “contest” our results. They advocate using alternative methods for estimating risk-adjusted returns and excluding some observations from our sample. Amihud and Stoyanov claim that making such changes renders our results not significant (though retaining their direction) and conclude that staggered boards have no significant effect on firm value. This paper examines and replies to the Amihud-Stoyanov challenge. We question their methodological claims, study the consequences of following their suggestions, and conduct additional robustness tests. Our analysis shows that the evidence is overall consistent with the results and conclusions of our JFE paper.

United Biomedical, Inc. (UBI) has developed a set of core technologies for the discovery and production of synthetic peptide-based immunotherapeutics and vaccines. These core technologies have led to products that stimulate functional site-directed antibody responses for therapeutic effects. UBI active immunotherapies can be used to modulate physiological processes effective for the control of cell entry by HIV virions, for control of prostate cancer and allergy, and for immunocastration in livestock leading to boar taint elimination and growth promotion in swine. The UBI technologies are also useful to stimulate site-directed antibodies against pathogenic agents such as foot-and-mouth disease virus. UBITh® Immunotherapeutic peptides were developed as antigens to direct antibody responses against targeted epitopes on self-proteins and viral pathogens that are responsible for biological functions and pathogenicity. A collection of promiscuous UBITh® T helper cell epitopes was used to impart these functionally antigenic peptides with immunogenicity. The T cell helper epitopes were covalently linked to the functional antigenic target sites by peptide synthesis, creating well-defined synthetic immunogens. Finally, vaccine formulations were selected appropriate for the delivery of peptide immunogens. Controlled production processes and the means to characterize the final product provide a framework for the GMP-compliant manufacture of UBITh® immunotherapeutics and vaccines.

A standardized and rapid peptide-based SARS assay is characterized for sensitivity and specificity., A peptide-based enzyme-linked immunosorbent assay (ELISA) can be used for retrospective serosurveillance of severe acute respiratory syndrome (SARS) by helping identify undetected chains of disease transmission. The assay was developed by epitope mapping, using synthetic peptides from the spike, membrane, and nucleocapsid protein sequences of SARS-associated coronavirus. The new peptide ELISA consistently detected seroconversion by week 2 of onset of fever, and seropositivity remained through day 100. Specificity was 100% on normal blood donor samples, on serum samples associated with infection by other pathogens, and on an interference panel. The peptide-based test has advantages of safety, standardization, and automation over previous immunoassays for SARS. The assay was used for a retrospective survey of healthy healthcare workers in Taiwan who treated SARS patients. Asymptomatic seroconversions were detected in two hospitals that had nosocomial disease.

A class of synthetic peptide immunogens for the cell surface HIV receptor complex has been developed to elicit antibodies that block viral entry by inhibiting gp120-CD4 interaction. These peptides extend our HIV receptor-directed approach from passive immunotherapy with mAb B4 (Proc. Natl. Acad. Sci. U.S.A. 96 (1999) 10367) to active immunization by a synthetic peptide-based vaccine. A peptide site from CD4 was identified a s a B cell epitope capable of mimicking a susceptible site on the HIV receptor complex, and then rendered immunogenic. An effective target antigenic site (B cell epitope) for the cell surface HIV receptor complex was selected by epitope mapping from among diverse CD4 and chemokine receptor peptides. It is a cyclized sequence modified from the CDR2-like domain of CD4 (AA 39–66), that was predicted to produce steric hindrance of the discontinuous recognition site of mAb B4. The immunogenicity of the targeted epitope was augmented by tandem combination with promiscuous T helper cell epitopes (Th). The antibody response to this class of immunogens attained sufficient concentrations and affinities of the correct specificity to block the interactions of HIV env glycoprotein with the cellular receptor, and prevent infection. The polyclonal antibodies generated against these fusion constructs in multiple animal species neutralized a broad array of HIV-1 primary isolates from clades A to E. Despite eliciting antibodies to the key CD4 immunomodulatory molecule, the site-specific and chemically defined immunogens displayed no overt immunotoxicity in baboons and have potential for the immunotherapy and immunoprophylaxis of HIV infection. © 2002 Elsevier Science Ltd. All rights reserved.

We have designed a peptide-based vaccine for foot-and-mouth disease (FMD) effective in swine. The peptide immunogen has a G–H loop domain from the VP1 capsid protein of foot-and-mouth disease virus (FMDV) and a novel promiscuous T helper (Th) site for broad immunogenicity in multiple species. The G–H loop VP1 site was optimised for cross-reactivity to FMDV by the inclusion into the peptide of cyclic constraint and adjoining sequences. The incorporation of consensus residues into the hypervariable positions of the VP1 site provided for broad immunogenicity. The vaccine protected 20 out of 21 immunised pigs from infectious challenge by FMDV O1 Taiwan using peptide doses as low as 12.5 μg, and a mild adjuvant that caused no lesions. A safe chemically-defined product would have considerable advantages for vaccination against FMD.

The Helmholtz-Smoluchowski (H-S) velocity is known to be an accurate and useful formula for estimating the electro-osmotic (EO) flow rates in a simple micro-channel with a thin electric-double layer. However, in case the channel cross section is not so simple, the usefulness of H-S velocity could be sharply limited. A case of fundamental interest representing this situation is a rectangular channel (comprising parallel plates) with built-in vertical gratings, in which the surfaces inside the channel may develop different normalized zeta potentials α (on the gratings) and β (on the side walls). In this study, analytical solutions are pursued under the Debye-Huckel approximation to obtain EO pumping rates in a rectangular channel with vertical gratings. In particular, we identify the conditions under which the H-S formula can be properly applied and investigate how the EO flow rates may deviate from those predicted by the H-S velocity with varying physical parameters. Moreover, a diagram of the optimal EO p...

mAb B4 is a monoclonal antibody directed against HIV receptor complex. The antibody had broad neutralizing activity against HIV and provided postexposure prophylaxis to hu–peripheral blood leukocyte (PBL)–severe combined immunodeficient mice and chimpanzees. B4 recognized a complex receptor site for HIV on the T cell surface that includes CD4 and also may be influenced by interaction with HIV coreceptors. mAb B4 preferentially neutralized primary HIV-1 isolates compared with T cell line-adapted strains, including syncytium-inducing and non-syncytium-inducing phenotypes, representatives from HIV-1 subtypes A-G, as well as HIV-2, simian immunodeficiency virus, and chimeric simian/human immunodeficiency virus (SHIV). Neutralization was demonstrated in both pre- and postinfection models. The administration of mAb B4 after infectious challenge totally interrupted the infection of hu-PBL–severe combined immunodeficient mice by PBL-grown HIV-1 and the infection of chimpanzees by chimp-adapted HIV-1. This mode of protection suggested that the anti-HIV receptor antibody is efficacious for prophylaxis after exposure to HIV and for prevention of maternal transmission and may be an effective antiretroviral agent for treatment.

A fungus biosensor based on an oxygen electrode and Aspergillus ustus immobilized in poly(vinyl alcohol) was developed to determine tannic acid in a batch system. The optimum temperature was 30.0°C and the optimum pH was 7.0 in 0.10 M phosphate buffer. The regression equation of the calibration curve between 0.0250 and 1.025 mM was (x ln y ) (−0.72724− x 0.53 /54) + C ( x ln y ) (−0.21891− x 0.08 /2) = A + B/x ( r ≥ 0.99985). The sensor had a life of at least 2 weeks; it yielded a negligible response to the compounds commonly coexisting with vegetable tannins.

A methylene blue (MB) poly (vinyl chloride) membrane electrode based on MBtetraphenylborate (TPB) ion-pair complex is described. The linear response covers the range 1x10−2 - 1x10−6 mol dm−3 MB solution, with a slope of 56.5±0.5 mv/decade (pH range 3.0-1 0.0). The detection limit is 7.75x 10−7 mol dm−3. The electrode shows stability, good reproducibility and fast response. Interferences from common inorganic cations and some organic bases are negligible. These characteristics of the electrode enabled it to be used successfully for the determination of MB in injection.

Tetanus toxoid (TT) was encapsulated in microparticles prepared from polylactide-co-glycolide polymers by a solvent-evaporation technique. Combinations of small- and large-sized microparticles with controlled-release characteristics were used to immunize Sprague-Dawley rats, and the antibody responses were monitored for 1 year. For comparison, control groups of rats were immunized at 0, 1, and 2 months with TT adsorbed to alum. The antibody responses generated by the TT entrapped in microparticles were comparable to those generated by TT adsorbed to alum in control groups from 32 weeks onwards. Microparticles with a single entrapped antigen (TT) induced better antibody responses than microparticles with two antigens (TT and diphtheria toxoid) entrapped simultaneously. A combination vaccine consisting of TT adsorbed to alum and also entrapped in microparticles gave the best antibody responses. In an inhibition assay designed to determine the relative levels of binding of antisera to the antigens, the sera from the microparticle- and the alum-immunized animals showed comparable levels of binding. In addition, in a passive-challenge study with mice, TT adsorbed to alum and TT entrapped in microparticles provided equal levels of protection against a lethal challenge with tetanus toxin. An intradermal-challenge study was also performed with rabbits, which showed similar levels of protection in sera from alum- and microparticle-immunized animals at 4, 12, and 32 weeks after immunization.

Hepatitis B surface antigen (HBsAg) was encapsulated in microparticles prepared from polylactide-co-glycolide (PLG) and polylactide (PLA) polymers using a solvent evaporation process. The immunoreactivity of the entrapped antigen was investigated by SDS-PAGE and Western blot. The microencapsulation process was modified to obtain both small (10 microns) and large microparticles (10-100microns). 80% of the antigen was encapsulated. Various combinations of small and large microparticles with controlled release characteristics were investigated in CD1 mice. Groups of animals were immunized with 30 micrograms equivalent of HBsAg in microparticles per animals. The control group received, three injections of 10 micrograms of HBsAg on alum at 0, 1 and 6 months. Results indicated that a single injection of HBsAg in microparticles could maintain the antibody response at a level comparable to the three-injection alum schedule for at least 1 year. An in vitro inhibition assay was developed to demonstrate that antigen-antibody reactivity were comparable for the microparticle immunized mice and the alum immunized mice. A competition assay with a monoclonal antibody specific for the neutralizing epitope of HBsAg demonstrated comparable binding for the sera from the microparticle and alum immunized mice.

It is known that the eletroosmotic (EO) flow rate through a nano-scale channel is extremely small. A channel made of a periodic array of slats is proposed to effectively promote the EO pumping, and thus greatly improve the EO flow rate. The geometrically simple array is complicated enough that four length scales are involved: the vertical period 2L, lateral period 2aL, width of the slat 2cL as well as the Debye length λD. The EO pumping rate is determined by the normalized lengths: a, c, or the perforation fraction of slats η=1-(c/a) and the dimensionless electrokinetic width K=L/λD. In a nano-scale channel, K is of order unity or less. EO pumping in both longitudinal and transverse directions (denoted as longitudinal EO pumping (LEOP) and transverse EO pumping (TEOP), respectively) is investigated by solving the Debye-Hückel approximation and viscous electro-kinetic equation. The main findings include that (i) the EO pumping rates of LEOP for small K are remarkably improved (by one order of magnitude) when we have longer slats (a≫1) and a large perforation fraction of slats (η0.7); (ii) the EO pumping rates of TEOP for small K can also be much improved but less significantly with longer slats and a large perforation fraction of slats. Nevertheless, it must be noted that in practice K cannot be made arbitrarily small as the criterion of φc≈0 for the reference potential at the channel center put lower bounds on K; in other words, there are geometrical limits for the use of the Poisson-Boltzmann equation.

Rhodotorula taiwanensis RS1 is a high-aluminum (Al)-tolerant yeast that can survive in Al concentrations up to 200 mM. The mechanisms for the high Al tolerance of R. taiwanensis RS1 are not well understood. To investigate the molecular mechanisms underlying Al tolerance and toxicity in R. taiwanensis RS1, Al toxicity-induced changes in the total soluble protein profile were analyzed using two-dimensional gel electrophoresis (2-DE) coupled with mass spectrometry. A total of 33 differentially expressed proteins responding to Al stress were identified from approximately 850 reproducibly detected proteins. Among them, the abundance of 29 proteins decreased and 4 increased. In the presence of 100 mM Al, the abundance of proteins involved in DNA transcription, protein translation, DNA defense, Golgi functions and glucose metabolism was decreased. By contrast, Al treatment led to increased abundance of malate dehydrogenase, which correlated with increased malate dehydrogenase activity and the accumulation of intracellular citrate, suggesting that Al-induced intracellular citrate could play an important role in detoxification of Al in R. taiwanensis RS1.

We have investigated the capacity of synthetic peptides delivered in different adjuvant formulations to induce cytotoxic T lymphocyte (CTL) responses to a class I H-2K d -restricted Plasmodium berghei circumsporozoite epitope, CS 252–260. Using three immunogen formulations: soybean emulsion; Montanide ISA720; and lipopeptide (P3-CS), we first evaluated the effects of immunization routes on CTL induction. No CTL response was induced in mice immunized s.c. or i.p. with CS peptide formulated in soybean emulsion. In contrast, immunization with lipopeptide P3-CS either s.c. or i.p. effectively primed for CTL. Interestingly, CS peptide emulsified in Montanide ISA720 induced a CTL response only when delivered s.c. and not i.p., indicating the critical influence of immunization routes on CTL induction. We then compared the effectiveness of eight adjuvant formulations to induce CTL response following a single s.c. immunization. Notably, lipopeptide P3-CS and CS peptide admixed with P3 or POE lipid molecules stimulated a vigorous CTL response. However, only mice immunized with P3-CS and CS peptide admixed with P3 molecule generated long-lived CTL which persisted in vivo for 5 months. Thus, based on a simultaneous comparison of the different adjuvant formulations, we demonstrated that the conjugated and unconjugated P3 lipopeptides were the most effective immunogens for eliciting primary and memory CTL in mice.

A microencapsulated vaccine was prepared, containing a branched peptide immunogen (200M), representing a portion of the principal neutralizing determinant of HIV-1, entrapped in poly (lactide-co-glycolide) microparticles. Following extensive in vitro characterization of the microparticles, which included assessments of particle size and size distributions, microparticle surface structure, antigen loading level and efficiency of entrapment, moisture content, the levels of residual solvent, the in vitro release rate, an assessment of antigen integrity, the product bioburden and stability during storage, the microparticles were assessed in vivo. The initial assessments undertaken, involved studies in different animal species to determine the safety and pyrogenicity of the vaccine and also the toxicity following oral administration. Once the microparticles had been shown to be safe, pyrogen free and non-toxic, they were assessed for their ability to induce serum IgG and neutralizing antibody responses in guinea pigs. Following oral immunization alone, and combined oral and subcutaneous immunization, the microparticles were shown to induce high levels of both serum IgG and neutralizing antibodies against HIV. Pending review by the U.S. Food and Drugs Administration, the microparticle based oral vaccine against HIV-1 will be assessed in clinical trials in seronegative human volunteers.

Aluminum (Al) toxicity is a primary limitation to crop growth in acidic soils. Rice (Oryza sativa L.) seedlings exposed to Al show significantly inhibited root growth. To understand the precise mechanisms underlying Al toxicity, a comparative protein profile analysis of roots from two rice cultivars was conducted using 2-DE and MALDI-TOF/TOF-MS. A total of 79 Al-regulated proteins were identified, from which 54 and 45 proteins were differentially regulated in Kasalath (Al-sensitive) and Koshihikari (Al-resistant) cultivars, respectively. Gene Ontology and clustering analysis revealed an increase in relative abundance in vacuolar H(+)-ATPase, whereas structural proteins were decreased in both cultivars. Under Al toxicity, proteins involved in the antioxidative system, carbohydrate and nucleotide anabolism were increased in Koshihikari, whereas proteins participating in pathogenesis and carbohydrate catabolism were increased in Kasalath. Furthermore, the abundance of proteins involved in signal transduction, translation and transcription were different between the two cultivars. Our results suggest that destruction of the molecular structure is a major cause of cellular damage, and vacuolar sequestration of Al ions is an important Al resistant mechanism in rice. Both active oxygen scavenging systems and carbohydrate metabolism could play important roles in determining the Al tolerance among rice cultivars.

The traditional formula and calculation method for calculating the ultimate bearing capacity is not scientific. According to the research, the ultimate bearing capacity is equal to the real degree of the material and detection force product. Ultimate bearing capacity is not for the change of detecting the force. On the basis of this understanding, a new theory of the study bearing capacity of rock-soil and new methods is generated.

In this paper, we investigate rotating electro-osmotic (EO) flow over an infinite plate or in a channel formed by two parallel plates. The analysis is based on the Debye-Huckel approximation for charge distributions and the Navier-Stokes equation for a transport electrolyte in the rotating frame. It is shown that, for the single plate, the nondimensional speed of system rotation ω is the singly most important parameter, while for the channel, in addition to ω, the nondimensional electrokinetic width K also plays an important role. However, the parameter ω≡η(2) has different natural appearances in the respective cases of a single plate (SP) and two plates (TPs). More precisely, η(SP) measures the ratio λ(D)/L(K) of the Debye length to the Ekman depth, while η(TP) measures the ratio L/L(K) of the channel width to the Ekman depth. The effect of rotation is always to reduce the axial flow rate along the direction of the applied electric field, accompanied by a (secondary) transverse flow. In the SP case, the plot on the velocity plane for each ω shows an interesting closed EO Ekman spiral. The size of the spiral shrinks with increasing ω. The transverse flow is so significant that the volume transport associated with the EO Ekman spiral turns clockwise 45° to the applied field near ω=0 and gradually turns at a right angle to the applied field as ω is increased. In contrast, in the TP case, the transverse flow rate is smaller than the axial flow rate when ω is small. The transverse flow rates at all K are observed to reach their maxima at ω of order 1. The volume transport is nearly at a zero angle to the applied field near ω=0 and gradually turns to 45° to the applied field as ω is increased. In the limit of ω→∞, for both SP and TP cases, the entire system forms a rigid body rotation-there is neither axial nor transverse flow.

The electro-osmotic flow driven by a screen pump, composed of a line array of evenly spaced identical rectangular solid blocks, is investigated under the Debye-H\"uckel approximation. The geometry of the screen pump is determined by the spacing and aspect ratio of the solid blocks. A constant surface zeta potential is assumed on the block surface. The method of eigenfunction series expansion is applied to solve analytically for the applied electric field, electric charge potential in the fluid, and flow field. Because of the low Reynolds number, Stokes equations are applied for the flow. The analytic result is first confirmed by comparing with the exact solution of the electro-osmotic flow in an infinite channel. Then different geometries of the screen pump and the effect of the electrokinetic width are computed for their influence on the flow rate. Recirculating eddies and reversing flow are found even though the applied electric driving field is unidirectional.

Improved serologic and polymerase chain reaction (PCR)-based tests for hepatitis C virus (HCV) infection provided an opportunity to reexamine a posttransfusion follow-up study done from 1969 to 1972. A total of 213 cardiac surgery patients was prospectively followed after receiving an average of 18 units of blood, 24% of which was from paid donors. Serial sera were tested for antibody to recombinant DNA-derived C100-3 and capsid polypeptides; selected cases were also tested against synthetic peptides derived from different regions of the HCV sequence. PCR and RIBA II immunoblot assays were done on selected sera. Each of 55 probable and 5 of 11 possible hepatitis cases who were seronegative before transfusion seroconverted. Anti-HCV seroconversion also occurred in 6 (4%) of 148 subjects without hepatitis. Among subjects followed > 1 year, PCR positivity persisted in 14 (82%) of 17. If the results of this study can be generalized, all bloodborne non-A, non-B hepatitis may be due to HCV.

The prevalence of antibodies to hepatitis C virus (anti-HCV) in a hepatitis B virus hyperendemic region was evaluated with a second-generation enzyme immunoassay. A general population of 1500 from Northern Taiwan was tested with this immunoassay which includes synthetic peptides from the capsid and non-structural protein region as the solid-phase antigen. A total of 37 subjects out of 1500 (2.5%) were positive, with no significant difference in distribution between hepatitis B antigenemic and non-antigenemic samples. The prevalence of anti-HCV was higher in subjects with abnormal than those with normal liver function tests (8.2% vs. 1.5%). Prevalence increased with age. By polymerase chain reaction, 43% of anti-HCV-positive samples were HCV-RNA-positive. However, only 1 (0.6%) of 150 anti-HCV-negative subjects had HCV-RNA. Comparison of the results with those from a conventional recombinant C100-3-based assay showed that the capsid/non-structural region synthetic antigen system provided more accurate sensitivity and specificity. The more sensitive assay revealed a high prevalence for HCV infection of 2.5% among this general population in Taiwan.

The paper presents semi-analytical solutions to electro-osmotic (EO) flow through polygonal ducts under the Debye-Huckel approximation. Analytical series solutions assisted with numerical collocations are found to yield very fast convergence. The solutions have practical applications as the pores of EO membranes are mostly hexagonal, stacked densely in a beehive-like matrix. In addition, we develop simple asymptotic approximations that would be applicable to all EO tube flows of small as well as large dimensionless electrokinetic width. This facilitates investigation of analytical structures of general EO flows in all shapes of tubes, including the present geometries. In particular, for thick electrical double layers, the flow rate of EO is related to the corresponding viscous Poiseuille flow rate, while for thin electrical double layers, the flow rate is shown to be characterized by the cross-sectional area and the perimeter length of the tubes.

Sera of 40 patients with posttransfusion non-A, non-B hepatitis were tested for hepatitis C and B viral genomes by polymerase chain reaction and for hepatitis C antibodies by synthetic peptide immunoassays. Five were then considered to have chronic hepatitis before transfusion. Six patients without hepatitis C markers and hepatitis B virus DNA recovered. In 29 recipients who became positive for hepatitis C virus RNA, posttransfusion hepatitis C was diagnosed. Of them, 5 were hepatitis B surface antigen carriers. Synthetic peptide immunoassays detected 28 whereas anti-C100 assay detected 23 of the 29 acute hepatitis C patients. Anticapsid antibody appeared earlier than the antinonstructural antibody in 10 seroconverters. They appeared simultaneously in 15 seroconverters but anticapsid antibody appeared later then the antinonstructural antibody in 3 hepatitis B carriers. Transient suppression of hepatitis B surface antigenemia was found in 2, whereas elevated hepatitis B virus DNA was found in 3 carriers during acute hepatitis C superinfection. In 2 carriers whose hepatitis C became chronic, both hepatitis B and C viral genomes persisted throughout 2 years of foliowup. Therefore these assays define posttransfusion hepatitis C more precisely, and there seems no significant interference between chronic hepatitis B and C virus infections.

A titer for homologous viral neutralization activity (greater than 1:19,683) was observed after a 3.5-year immunization period with an octameric, branching peptide representing the principal neutralizing determinant (PND) of the human immunodeficiency virus-1IIIB envelope protein. Booster immunizations elicited persistent and potent antibodies in guinea pigs, exceeding responses produced by a conventional bovine serum albumin conjugate by 100-fold. Peptide length, central presentation of a conserved sequence, and inclusion of an upstream sequence contributed to immunogenicity. Titers (greater than 1:1,000) of heterotypic neutralizing antibodies also developed. Octameric PND peptides are a promising approach for an acquired immunodeficiency syndrome (AIDS) vaccine.

The immunological phenotypes of lymphocytes and myeloma cells in 48 patients with multiple myeloma (MM) were analyzed using a panel of monoclonal antibodies (mAbs). Myeloma cells were positive for OKT10, BL3, PCA1 and BA2. In a few cases, they were also positive for the B cell-associated antigens J5, B1 and I2. Eight of 48 cases had more than 15% J5-positive lymphocytes, and some lymphocytes in MM expressed plasma cell-associated antigens (PCA1, BL3, OKT10), suggesting a possible clonal involvement. These observations demonstrate the heterogeneity of surface antigen expression of myeloma cells and suggest that BL3, PCA1, BA2 and J5 may be useful mAbs for purging myeloma cells from bone marrow for autologous transplantation.

Luteinizing hormone-releasing hormone (LHRH)-derived decapeptide-based vaccines have been used in studies of immunocastration and immunotherapy of prostate cancer, but no image data are available on the kinetics of vaccines post injection (p.i.). Therefore, an 131I radiolabeled LHRH-derived immunogen was developed to visualize and evaluate the retention of LHRH-derived vaccines in rats.The LHRH immunogens, which contained equal moles of 131I-p607E, p667 and p500, were formulated with an equal volume of an adjuvant, Montanide ISA50. MicroSPECT/CT imaging was performed to visualize the retention of the radiolabeled immunogen up to 30 days after intramuscular inoculation of 25 microg immunogens. The pharmacokinetics, distribution and excretion were also evaluated.The radiochemical purity of 131I-p607E was 97.85+/-2.12%. The longitudinal microSPECT/CT imaging revealed that most 131I-p607E was retained at the injected muscle site until 30 days p.i.. Biodistribution showed that 34.56+/-4.27% of radioactivity remained at the injected muscle site at 28 days p.i.. The cumulative radioactivity excreted via urine was 30.02+/-3.82% up to day 28 p.i.. The elimination half-life (t1/2), Tmax and Cmax were 158.67 h, 24 h, and 0.026 percentage of injected dose per gram (%ID/g), respectively.The LHRH immunogen, 131I-p607E, was mainly retained at the intramuscular injection site during the whole study period. The microSPECTICT imaging modality can be used to monitor the location and distribution of the LHRH immunogen, 131I-p607E, in a rat model.

The UBITh ® AD immunotherapeutic vaccine for Alzheimer’s disease uses an amyloid- (A) immunogen having two designer peptides that have been engineered to elicit anti-N terminal A1–14 antibodies while minimizing potential for the generation of adverse anti-A immune responses. The vaccine has been further designed for minimization of inflammatory reactivities through the use of a proprietary vaccine delivery system that biases Th2 type regulatory T cell responses in preference to Th1 pro-inflammatory T cell responses. In vitro studies and in vivo studies in small animals, baboons and macaques show that anti-A antibodies are generated with the expected N-terminus site-specificity, and that these antibodies have functional immunogenicities to neutralize the toxic activity of A and promote clearance of plaque deposition. The antibodies appear to draw A from the CNS into peripheral circulation. Results indicate that the UBITh ® AD vaccine did not evoke anti-A cellular responses in a transgenic mouse model for AD. The vaccine was safe and well tolerated in adult Cynomolgus macaques during a repeat dose acute and chronic toxicity study. © 2007 Elsevier Ltd. All rights reserved.

We have experimentally demonstrated that stored and retrieved light pulses have different frequencies but maintain phase coherence; a stored light pulse is released with a different polarization. However, the manipulation process causes an energy loss of the retrieved pulse. We have discovered that Clebsch-Gordan coefficients among the Zeeman sublevels play an important role in the energy loss and have demonstrated a solution for avoiding the energy loss.

Compartmental analysis is the most important modeling tool in biology and medicine. The perturbation due to a tracer in a biomedical system usually leads to a linear system that can be described by a compartmental matrix. The reducibility of the compartmental matrix has important implications on the system, both analytically and computationally. This note provides an efficient algorithm to determine the reducibility of a compartmental system. Furthermore, if reducible, the algorithm provides a means to delineate the sub-systems to be successively solved.

We have systematically studied the method proposed by Patnaik et al. [Phys. Rev. A 69, 035803 (2004)] that manipulates the retrieval of stored light pulses. The measured probe pulse width of the retrieval is inversely proportional to the intensity of the reading field. We also show that the method does not introduce any phase shift or jump into the retrieved pulses. Our study demonstrates that the distortion at the output of the light storage can be corrected by manipulating the retrieval process and the phase information of the stored pulses can remain intact during the process.

We experimentally demonstrate a low-light-level cross-phase-modulation (XPM) scheme based on the light-storage technique in laser-cooled $^{87}\mathrm{Rb}$ atoms. The proposed scheme can achieve a similar phase shift and has the same figure of merit as one using static electromagnetically induced transparency under the constant coupling field. Nevertheless, the phase shift and the energy loss of a probe pulse induced by a signal pulse are neither influenced by the coupling intensity nor by the atomic optical density in the light-storage XPM scheme. This scheme enhances the flexibility of the experiment and makes possible conditional phase shifts on the order of $\ensuremath{\pi}$ with single photons.

We have designed a peptide-based immunotherapeutic vaccine for treatment of androgen-responsive prostate cancer. The vaccine targets the luteinizing hormone-releasing hormone (LHRH) decapeptide that results in an androgen-deprivation immunotherapy. The design elements of the peptide immunogens are the LHRH peptide or B cell epitope synthetically linked to different promiscuous helper T cell (Th) sequences, the UBITh epitopes, derived from four natural pathogens for effective immunogenicity in outbred populations, and in some cases, also linked to an adjuvanting peptide from Yersinia invasin (Inv) protein. The UBITh LHRH immunogens are adsorbed on Alhydrogel or formulated as several different oil-based emulsions and tested in rodents, dogs, and a non-human primate, baboons. The immunogens generate an anti-LHRH antibody response specific to the LHRH decapeptide element in contrast to LHRH conjugate-carrier protein vaccines where only a small portion of the antibody response is directed to the target epitope and epitopic suppression is noted. Individual UBITh peptide domains, but not the LHRH and Inv peptide domains, are stimulatory in lymphocyte cultures. The UBITh LHRH immunogens in a clinically applicable formulation, controlled the growth of Dunning R3327-H androgen-responsive prostate tumor cells in rats. The results demonstrate universal responsiveness and long duration of androgen deprivation from three diverse species, and thus vaccine efficacy.

An immunotherapeutic vaccine for allergy was produced by designing IgE-based synthetic peptide immunogens and selecting them for functional immunogenicity. The vaccine targets the binding site on IgE for the high affinity receptor Fc eRI, by active immunization. The peptide target site on IgE heavy chain was selected from among the amino acid sequences for the Ce2, Ce3, and Ce4 domains. These were characterised by epitope mapping studies for cross-reactivity to IgE and functional antigenicity. A peptide, modified from positions 413–435 of a loop region of Ce3 and subjected to conformational constraint, elicited anti-IgE antibodies that blocked IgE-mediated histamine release. It was immunopotentiated by linkage to a promiscuous T helper site to produce a wholly synthetic chimaeric immunogen. This immunogen was shown to induce polyclonal site-specific anti-IgE antibodies that obstruct binding to Fc eRI, inhibit histamine release by IgE-sensitised basophils, inhibit passive cutaneous anaphylaxis, and do not signal degranulation. Immunized dogs experienced significant reductions in total serum IgE. © 2002 Elsevier Science Ltd. All rights reserved.

The establishment of a certified ISO Guide 25 testing laboratory for medical devices is an important corner stone for a better national medical device management system and practices of the assorted standards or guidelines. It can also contribute significantly to the educational program for clinical engineer. As a starting point, a medical electrical safety-testing laboratory according to the AAMIES-1 (1993) and IEC 60601 (1988) has been setup and devoted to the safety of electromedical apparatus with joined efforts of the Institute of Biomedical Engineering, National Taiwan University and Department of Biomedical Engineering, National Taiwan University Hospital. To ensure its quality of services, ISO/IEC Guide 25 is implemented and certified by Chinese National Laboratory Accreditation (CNLA). In view of the global harmonization, this painstaking procedure for a medical device-testing laboratory can be fruitful in the aspects of quality assurance for the imported devices and post-market surveillance. It also has positive impact on the infrastructure of domestic medical device regulation and development. In this report, the authors discuss the necessary procedures to train a clinical engineer to account for this need.

We have identified continuous antigenic determinants within the amino acid sequences of the conserved nonstructural region containing proteins 2C and 3ABC of foot-and-mouth disease virus which can distinguish between the sera from vaccinated and infected animals. An ELISA based on a 3B peptide gave a positive reaction with sera from cattle, pigs, sheep and guinea pigs infected with all seven serotypes of the virus, but not with sera from vaccinated animals. In experiments with cattle and pigs to determine the duration of the antibody response, positive reactions were obtained as late as one year after infection. The advantages of using peptides from the nonstructural viral proteins instead of recombinant proteins for differentiating vaccinees from infected animals include their exquisite specificity, nonreactivity with antibodies against host cell-derived proteins (e.g. E. coli and insect cell proteins), and their ease of preparation.

A methylene blue (MB) poly(vinyl chloride) membrane sensor based on MB-silicotungstate (SLT) ion association as electroactive material was described. The linear response covered the range 1 x 10(-3)-1 x 10(-6) mol x dm(-3) MB solution, with a slope 52.0+/-0.8 mV decade(-1) (pH range 3.0-10.0). The detection limit was 7.65 x 10(-7) mol x dm(-3). The electrode showed stability, good reproducibility and fast response. Interferences from common inorganic cations, some organic base were negligible. These characteristics of the electrode enabled it to be used successfully for the determination of MB in injection. There was a good agreement for the results of MB content in injection between potentiometric method and USP standard procedure.

A methylene blue poly (vinyl chloride) membrane electrode based on methylene blue-phosphotungstate ion-pair complex as electroactive material is described. The linear response covered the range of 1 × 10–3 – 1 × 10–6 mol dm–3 methylene blue solution, with a slope of 51.5 ±0.8 mV/decade (pH range 3.0–10.0). The detection limit was 6.79 × 10–7 mol dm–3. The electrode showed stability, good reproducibility and a fast response. Interferences from common inorganic cations and some organic bases were negligible. These characteristics of the electrode enabled its successful use for determination of methylene blue in injection. There was good agreement for the results of methylene blue content in injection between the potentiometric method and the United States Pharmacopoeia standard procedure.