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Chronoamperometric investigations with rotating disc electrodes (RDEs) were used to characterise the anodic half-cell of yeast powered microbial fuel cells using methylene blue (MB) as a mediator. Both convection and mediator adsorption were shown to affect the anodic current. A microbe–mediator limited reaction model was developed and shown to agree well with the experimental data. A power density of ∼150 μW cm–2 was achieved in a full cell, which represented a significant increase from prior reports on yeast-catalysed fuel cells. The increased power density was enabled by using high mediator concentrations and by controlling the mediator adsorption.

The rheological and structural characteristics of polyimides with enhanced melt flow have been investigated. The polyimides were based on 2,3,3′,4′-biphenyltertracarboxylic dianhydride (PBDA) and a mixture of a diamine, 4,4′ (1,4-phenylene-bismethylene) bisaniline (BAX) and a triamine, 1,3,5-Tris (4-aminophenoxybenzene), TAB, where the amount of TAB was 4 and 8%. Melt viscosities of these polymers suggest that they are processable by resin infusion methods. Although curing occurs through the phenylethynyl endcap, the steric and electronic differences of the three amines results in different cure kinetics and heterogeneous crosslinking. This is manifested in multiple Tg values in the differential scanning calorimetry (DSC) scan of the cured samples. Rheological and DSC kinetic studies of the cure behavior indicate that the sample with 4% TAB cures more quickly than the system with 8% TAB and it has a lower activation energy (147 versus 185 kJ mole-1). Thermal gravimetric analysis (TGA) scans indicate that both TAB based samples are more thermally stable than PMR-15. The lower activation energy for 8% TAB, relative to 4% TAB (147.0 versus 170.2 kJ mole-1) suggests the additional branching present decreases the thermal stability.

Vibration is a major problem for helicopters due to flexible rotating blades, an airspeed varying radially and temporally at each rotor blade section, and a highly unsteady aerodynamic environment due to nonuniform wake and dynamic stall. The complexity of the forcing means that efforts to reduce vibration through vibration absorbers and isolators yield only meager vibration reduction and lead to a large weight penalty. The performance of such passive devices also degenerates quickly away from the tuned flight condition. Piezoelectric stack actuators offer the possibility of active vibration control in helicopter rotors, through the actuation of judiciously placed trailing edge flaps at appropriate higher harmonic multiples of the main rotor speed. Such actuators need to be coupled with amplification mechanisms to generate sufficient rotary motion of about 2 degrees which is needed to dramatically reduce vibration by 70–90 %. However, hysteresis is inherent in stack actuators, and this complicates their use in helicopter vibration control. In this chapter, we look at hysteresis compensation methods which can be used along with harmonic optimal control for vibration reduction in periodic rotating systems. The danger of ignoring hysteresis effects on the controller is also highlighted.

Thin films of surfactant-templated mesoporous materials1,2 could find applications in membrane-based separations, selective catalysis and sensors. Above the critical micelle concentration of a bulk silica–surfactant solution, films of mesophases with hexagonally packed one-dimensional channels can be formed at solid–liquid and liquid–vapour interfaces3,4,5. But this process is slow and the supported films3,5 are granular and with the pore channels oriented parallel to the substrate surface, so that transport across the films is not facilitated by the pores. Ogawa6,7 has reported a rapid spin-coating procedure for making transparent mesoporous films, but their formation mechanism, microstructure and pore accessibility have not been elucidated. Here we report a sol–gel-based dip-coating method for the rapid synthesis of continuous mesoporous thin films on a solid substrate. The influence of the substrate generates film mesostructures that have no bulk counterparts, such as composites with incipient liquid-crystalline order of the surfactant–silica phase. We are also able to form mesoporous films of the cubic phase, in which the pores are connected in a three-dimensional network that guarantees their accessibility from the film surface. We demonstrate and quantify this accessibility using a surface-acoustic-wave nitrogen-adsorption technique. We use fluorescence depolarization to monitor the evolution of the mesophase in situ, and see a progression through a sequence of lamellar to cubic to hexagonal structures that has not previously been reported.

In view of a reported association between schizophrenia and the 5-HT2 receptor gene locus, as well as an association with treatment refractoriness at this locus, a case-control association study was conducted using a biallelic polymorphism. The distribution of the polymorphism was investigated among patients with schizophrenia (DSM-III-R, n = 174) and unaffected controls (n = 239). No significant differences in genotype distributions or allele frequencies were noted between the two groups. In support of the earlier report, a significant excess of individuals homozygous for allele C2 was noted among patients who responded unsatisfactorily to antipsychotic medication in comparison with the controls (odds ratio 1.78; 95% confidence intervals 1.06, 2.97). However, this difference was not significant following multivariate analysis. This study does not support an association between the 5-HT2 receptor gene locus and schizophrenia or subgroups based on treatment response.

Sera from schizophrenic patients (n = 186) and healthy control subjects (n = 346) were tested for the presence of seven common autoantibodies by standard immunological methods. The association between handedness and autoantibodies was tested in a multiway contingency table using a log-linear model. For men, but not women, nondextrals (patients and controls) were twice as likely to test positive for autoantibodies than dextrals (p = 0.0002). Although more women (33%) than men (24%) tested positive for autoantibodies, handedness was not a distinguishing factor among women. These data suggest that sinistrality and gender are associated with autoantibodies in a subgroup of schizophrenic patients and healthy control subjects.

A total of 57 schizophrenic patients (of which 17 were first-episode, neuroleptic naive) and 76 healthy controls were screened for anti-histone IgG antibodies using an enzyme immunoassay (ELISA). All patients had significantly higher anti-histone antibody titers than controls (t = 3.1, p less than 0.003). Previously medicated patients had significantly higher titers than neuroleptic-naive first episode patients (t = 2.87, p less than 0.006). This study suggests that neuroleptic medications are associated with anti-histone antibodies.

The present paper describes a hierarchical perception-linked model (HPLM) for recognition of all phonemes that have either characteristic formant structures or significant effects on the formant structures of the adjoining phonemes. The model essentially converts the multiclass multiparameter classification problem into a hierarchy of two-class single-parameter classification problems. The model is based on the perceptual phenomenon of substitution of F1 and F2 by a composite formant when their distance is less than a certain threshold and of comparison with stored prototypes otherwise. It is further shown that the above two perceptually different situations can also be viewed as the composite frequency lying between F1 and F2 in one situation and that lying below F1 in the other situation. The model is tested on adequate samples from Telugu vowels and laterals, Telugu unaspirated plosives, and Bengali vowels for many speakers. The recognition scores obtained for Telugu vowels, Telugu plosives, and Bengali vowels are 79%, 72%, and 83%, respectively.

Patients with schizophrenia (DSM IV, n = 149) and controls (n = 180) participated in a case-control association study in which a trinucleotide repeat polymorphism of pancreatic phospholipase A2 group 1B (PLA2G1B) was examined. Both African-American and Caucasian populations were included in this USA sample. There were no significant case-control differences, therefore his study does not support an association between schizophrenia and a PLA2G1B polymorphism on chromosome 12. © 1999 Lippincott Williams & Wilkins.

Weight gain has been reported with nearly every antipsychotic drug on the market (molindone is an exception). Weight gain occurs no matter what the patient's age, sex, or race and is seen with both oral and depot drug formulations. Numerous studies have found that patients gain weight when treated with a conventional antipsychotic, such as chlorpromazine, fluphenazine, and haloperidol. The newer, novel antipsychotics offer advantages over conventional antipsychotics, especially a relative lack of extrapyramidal symptoms, but some still have the disadvantage of causing weight gain. Clozapine and olanzapine in particular appear to cause substantial weight gain, much more so than do most conventional neuroleptics and novel agents such as risperidone. Given the risks to health and treatment compliance associated with weight gain and obesity, clinicians should monitor weight during the course of antipsychotic therapy and consider switching agents if excessive weight gain occurs.

A case control study was conducted among cases with schizophrenia (DSM IV criteria) and screened adult controls from three cohorts. Bi-allelic polymorphisms in the promoter region of the serotonin transporter gene (5-HTT) were examined in conjunction with those of the serotonin 5-HT2a receptor (HTR2). No significant association with 5-HTT was detected among US Caucasians (n = 207), African-Americans (n = 84) or Caucasians from Sweden (n = 221). However, survival analysis suggested an association with the age at onset among the Swedish cases. The association should be considered tentative as it was not evident in the smaller US samples. The following exploratory analyses among the US samples were also not significant: associations with subgroups of patients based on familiality or response to medications, or altered risk due to the joint effects of 5-HTT and HTR2 genotypes.

The effects of the availability of risperidone and olanzapine on the indications for which clozapine is prescribed (treatment-resistance, treatment-intolerance, and/or negative symptoms) were examined for 252 patients with schizophrenia who began treatment at our hospital between June 1990 and June 1997. There were no statistical differences in the indications for clozapine treatment before and after the availability of either risperidone or olanzapine. Furthermore, there were no significant differences in the frequencies of the indications in subgroups of patients who had previously received a trial with risperidone or olanzapine, as compared with the remaining patients. The indications for clozapine appear to have been unaffected by the advent of risperidone and olanzapine; however, we noted a decrease in the absolute number of patients starting clozapine after risperidone became available. More recently, the majority of patients referred for treatment with clozapine had received previous trials with risperidone or olanzapine.

The effectiveness of clozapine in the treatment of the negative symptoms of schizophrenia remains controversial, as improvements in negative symptoms are invariably accompanied by improvements in positive symptoms and neurological side effects. We examined the effectiveness of treatment with clozapine on negative symptoms in a cohort of patients with minimal positive symptoms. Improvements in positive and negative symptoms were measured by BPRS ratings in a subgroup of schizophrenic patients (n=17, from a state hospital cohort of 75) with minimal positive symptoms, who had received clozapine for 6 months. In this subgroup, significant improvements were noted by a composite score on the three negative symptom items of emotional withdrawal, blunted affect, and motor retardation. Positive and depressive symptoms remained unchanged. The remaining cohort (n=58) showed improvements in overall psychopathology including positive, negative, and depressive symptoms. Interestingly, nearly 50% of each group were discharged from the hospital. These findings suggest that clozapine may be beneficial in the treatment of core negative symptoms, even in the absence of other improvements in psychopathology. This effect of clozapine may be a function of its unique pharmacological profile.

To investigate procreation in schizophrenia, as well as gender-related differences, female patients with schizophrenia (n = 79, DSM-III-R criteria) were compared with screened female controls (n = 124) and subsequently with male patients (n = 86). Two outcomes were investigated: (i) the proportion of subjects with one or more children (an index of fertility) and (ii) the number of children per subject among those with one or more children (an index of fecundity). Multivariate analysis was used to control for confounding variables. No significant differences in fertility between female patients and controls were detected, but reduced fecundity was noted among female patients past the reproductive period. Male patients showed a significant reduction in both fertility and fecundity compared to female patients. These results suggest that there is a relatively small impairment of fecundity among female patients compared with controls, but that there are more significant gender-related differences in both fertility and fecundity. The latter have important implications for the genetics of schizophrenia.

Over the past 65 years, a variety of immunologic abnormalities have been reported in association with schizophrenia. These abnormalities have included alterations in lymphocyte subpopulations, alterations in immunoglobulin production both quantitatively and qualitatively, and altered cytokine physiology (for a review see Ganguli etal., 1994). Of these immunologic findings reported in association with schizophrenia, changes in cytokine physiology appear to be the most consistent and uncontroversial. This chapter will focus primarily on the evidence of cytokine abnormalities in a subgroup of patients, and will place these findings in the framework of the hypothesis that, for this subgroup of patients, an autoimmune process may play a pathogenetic role in their disorder. First, however, since this area of research remains mired in controversy and skepticism (DeLisi, 1996), some methodologic issues will be addressed, which pertain to the theoretical and practical aspects of study design and interpretation of results.

Using a case-control design, an association of schizophrenia with the dopamine D3 receptor gene (D3RG) locus was investigated. Initial analysis of pooled results from published studies revealed a significant excess of individuals homozygous for either allele among the patients. The association was next tested in two cohorts ascertained independently at Pittsburgh, Pennsylvania and at Houston, Texas. The Pittsburgh sample was comprised of patients with schizophrenia (DSM-III-R) (n = 130). The controls belonged to two groups: adults screened for the absence of substance abuse or major psychiatric illness (n = 128), and neonates (n = 160). Multivariate analysis suggested an association with allele 1 of the biallelic D3RG polymorphism in comparison with the adult, but not the neonatal, controls. The association was most marked among Caucasian patients with a family history of schizophrenia (odds ratio 13.69, confidence intervals 1.80, 104.30). Survival analysis suggested an earlier age of onset among male patients homozygous for allele 2. The Houston cohort included Caucasian patients with schizophrenia or schizoaffective disorder (DSM-III-R criteria, n = 50), and normal controls matched for gender (n = 51). In this group, no significant associations were noted among all the patients or among subgroups of patients based on family history or age of onset. Possible reasons for the discordant results are discussed.

Our hypothesis stated that patients with schizophrenia who had obstetric complications (OC) were more likely to have autoimmune abnormalities than those without OC. OC were rated using a checklist. Anti-brain autoantibodies were measured in serum using an enzyme immunoassay. Autoantibodies to non-CNS tissues were detected using serological procedures. There were no significant differences between the two groups with respect to anti-brain antibodies, but patients with OC (n= 24) had a significantly higher prevalence of autoantibodies to non-CNS tissues than patients without OC (n= 25). Both groups were receiving neuroleptic drugs. OC may contribute to autoimmune abnormalities among patients with schizophrenia.

The power densities of microbial fuel cells with yeast cells as the anode catalyst were significantly increased by immobilizing the yeast in electrically conductive alginate electrodes. The peak power densities measured as a function of the electrical conductivity of the immobilized electrodes show that although power increases with rising electrical conductivity, it tends to saturate beyond a certain point. Changing the pH of the anode compartment at that point seems to further increase the power density, suggesting that proton transport limitations and not electrical conductivity will limit the power density from electrically conductive immobilized anodes.

SynopsisSerum concentrations of anti-hippocampal antibodies andin vitroproduction of the lymphokine interleukin-2 (IL-2) in response to phytohaemagglutinin (PHA) stimulation were determined using an enzyme immunoassay in 49 schizophrenic patients and 41 healthy controls. Decrease in IL-2 production, a finding frequently associated with many autoimmune diseases, was associated with an elevation in anti-hippocampal antibody optical density (AHA-OD) in schizophrenic patients. Although some control subjects had elevated antibody levels, this elevation was not associated with decreased IL-2 production. Low IL-2 production is well known to be a state marker associated with active autoimmune disease. We suggest that production of hippocampal antibody is a trait marker of vulnerability to autoimmune diseases. Thus, our finding of low IL-2 production in patients with high concentrations of hippocampal antibody is compatible with the possibility that such patients have an ongoing autoimmune process.

Clozapine, an atypical neuroleptic, is an effective medication in a subgroup of schizophrenic patients who have either failed to respond to the typical neuroleptics or experienced intolerable side effects such as neuroleptic malignant syndrome and disabling tardive dyskinesia. Its efficacy for persistent and disabling akathisia is less clear. Akathisia, especially the chronic and disabling form, can be a treatment dilemma for the clinician and the patient.We describe three representative case illustrations of schizophrenic patients who had severe, persistent treatment-resistant akathisia. Two of them had refractory psychoses and the third had multiple disabling side effects during treatment with typical neuroleptics. Two had tardive dyskinesia. These patients were treated with clozapine while other neuroleptics were discontinued.During a 2-year follow-up, these patients made impressive social and vocational strides coinciding with a fairly rapid remission of akathisia (under 3 months) and a lesser though notable improvement in the psychoses. Tardive dyskinesia also remitted, though over a period of 6 to 12 months.Our experience leads us to suggest a trial of clozapine in a subgroup of schizophrenic patients, who in addition to refractory psychoses have persistent disabling akathisia. However, given the risk of agranulocytosis with clozapine, we suggest that the usual treatment strategies for akathisia be tried before clozapine is initiated in the approved manner. Future controlled trials of clozapine that specifically investigate persistent akathisia may answer this question more conclusively.

Processing can be controlled to produce a family of mesoporous silica films with either disordered, lamellar, hexagonal, or cubic pore distributions[l]. These films, formed by surfactant-templated synthesis and exhibiting a unimodal pore size, promise potential use as inorganic membranes, catalysts, and optically-based sensors[l,2]. The mesoporous films can be formed from initially homogeneous silica sols by a continuous, surfactant-templated process, which relies upon solvent evaporation during the sol-gel dip-coating process. Films of 100-500 nm thick are formed within seconds in a continuous coating operation. The microstructure of the films is dependent upon the cationic surfactant concentration CTAB (CH3(CH2)15N+(CH3)3Br-) and the dip-coating rate. Several films, processed under differing conditions, were investigated by TEM to characterize pore size, structure, and orientation.Figures 1 a & b show the plan view and cross-sectional microstructure of a 2-d hexagonal mesoporous silica film deposited on silicon; the sample was calcined at 400 °C for 3 hours in air. The images were obtained on a Philips CM30 TEM, operated at 300 kV.

Although ncurologic exam nbnonnalitics (NEA) arc gcnernlly :lssumed to represent static lesions, the accuracy of this assumption in schizophrenia is unknown. Several studies have found significant temporal inslttbility of NEA. but have done so acm...s pcriods of major change in lre:llmcnt ami clinical slllie. To identify [he particular NEA t1:~t tend to be stable over time, this study examined test-retest stability of NEA in two groups of chronic schizophrenic and schizoaffective patients. Seven stable medicated patients cnrolled in II longitudinal study of schizophrc. nill were examincd twice across a period of stable medication and clinical Slate (interval 46 :!: 23 days). using a modific:llion of Buchanan & Heinrichs' (19&9) Neurological Evaluation Scale (NES). Thirteen smble medicated patientI'; in a different study were also administered the NES while under similar medication and clinical conditions. before and aCler a period of medication withdrawal (107 :!: 48 d

Marder and Meibach reported a 46%-SS% chance (depending on dose level) of patients finishing an 8-week trial of risperidone. We also observed that there was a large proportion of patients for whom risperidone therapy was not beneficial. Of the 33 schizophrenic patients prescribed risperidone, 10 (30%) discontinued the medication after an average trial length of 14 weeks. The remaining 23 patients (70%) are being prospectively studied (current trial length is 14 weeks). Lack of clinical response explained seven of the 10 failures. Other reasons were noncompliance (N=2) and skin rash (N=1). We report a representative case of the ineffectiveness of risperidone for a patient who was resistant to standard neuroleptic treatment.