Ion selective electrode for cesium based on 5-(4'-nitrophenylazo)25,27-bis(2-propyloxy)26,28-dihydroxycalix[4]arene

A polyvinylchloride (PVC) based liquid membrane ion selective electrode (ISE) for cesium was fabricated with 5-(4'-nitrophenylazo)25,27-bis(2-propyloxy)26,28-dihydroxycalix[4]arene as ionophore. Different membrane constituents were investigated to realise optimum performance of the ISE developed. Of the four plasticizers and two ion additives studied, the best response was observed with membrane having 2-nitro phenyl octyl ether (oNPOE) as plasticizer and potassium tetrakis (perchloro phenyl) borate (KTpClPB) as ion additive. Linear response over concentration range of 10(-5)-10(-1)M CsCl was obtained. The Nernstian slope of the response was 56 mV per decade for Cs with a response time less than 20s. Matched potential method has been applied to find out the selectivity for Cs over several ions like Rb(+), K(+), Na(+), NH(4)(+), Sr(2+), Ba(2+), Ca(2+), Mg(2+), Cu(2+), Pb(2+), Zn(2+), Ni(2+) and Ce(3+). The response of ISE for Cs(+) was fairly constant over the pH range of 3-11. The lifetime of the electrode is 9 months which is the longest life for any membrane-based Cs-ISE so far developed. The concentration of cesium in two simulated high level active waste streams was determined and results agreed well with those obtained independently employing atomic absorption spectrometry.

Novel dansyl-appended calix[4]arene frameworks: fluorescence properties and mercury sensing

Covalently-attached fluorophores may impart enhanced chemosensing capabilities to calixarene frameworks. Synthesis and characterization of six novel dansyl-appended calix[4]arenes, namely, H/Dan4, NO2/Dan4, H/(OH)2Dan2, H/(Ester)2(Dan)2, t-Bu/(OH)2Dan2, and t-Bu/(Ester)2Dan2, containing two or four dansyl moieties are reported. Among these, fluorescence intensity of NO2/Dan4 is observed to decrease significantly in the presence Hg2+ in the solution. Based on the decrease in fluorescence, a limit of detection for Hg2+ of 20 ppb is obtained. NO2/Dan4 as a chemosensing agent for Hg2+ shows excellent selectivity and adequate reversibility. Complexation of NO2/Dan4 with Hg2+ is investigated using fluorescence spectroscopy and is observed to be 2:1. The formation constant of (NO2/Dan4)2Hg2+ is estimated to be 5.2(+/- 0.8) x 10(10) M(-2) at ambient conditions. These observations are traced to the fact that while all other dansyl-appended calix[4]arenes show cone conformation in the solution, NO2/Dan4 is in the 1,3-alternate conformation. Stokes shift versus solvent orientational polarizability for NO2/Dan4 also indicates the difference in the ground- to excited-state dipole moment of this compound to be the maximum among all six, rendering it most sensitive to its environment. Fluorescence emission of NO2/Dan4 in nonpolar chloroform, polar-aprotic acetonitrile, and polar-protic ethanol is observed to be different than that of the rest of the dansyl-appended compounds as well.

Quenching of pyrene fluorescence by calix[4]arene and calix[4]resorcinarenes

Interactions involving calixarene and its derivatives are of major importance due to their widespread applications as unique hosts. Fluorescence from a common probe pyrene is used to study interactions involving calix[4]resorcinarene [1a] and its tetra-morpholine derivative [1b] in 1 M aqueous NaOH. These compounds efficiently quench the pyrene fluorescence. A comparison with the fluorescence quenching behavior of N-methylmorpholine clearly indicates the presence of long-range interactions involving 1a and 1b; the interactions are specific to the calixarene molecular framework. This is not the case for a tetra-nitro-substituted calix[4]arene [2b], an electron/charge acceptor quencher, as p-nitrophenol also shows similar interactions with pyrene. Effectiveness of cesium as the quencher of pyrene fluorescence is reduced in the presence of electron/charge donating 1b; fluorescence enhancement is observed upon addition of cesium as the concentration of 1b is increased in the solution. The role of calixarene framework in interactions involving such compounds is established.

Convenient Direct Synthesis of Bisformylated Calix[4]arenes viaIpsoSubstitution

[reaction: see text] A facile synthesis of bisformylated calix[4]arenes via ipso substitution of p-tert-butylcalix[4]arenes through treatment with hexamethylenetetramine/trifluoroacetic acid is described. Under identical conditions, p-tert-butylcalix[4]arene tetramethyl ether 4 gives proximally substituted bisformylated derivative 4a in a pinched cone conformation.

Eysenck'S personality questionnaire scores of heroin addicts in India

One hundred and ten male heroin addicts were administered 'Eysenck Personality Questionnaire' a self reporting measure. High scores on psychoticism, neuroticism and lie scale and low scores on extroversion in heroin addicts as compared to normal controls (n=50) were observed in this study which were comparable with those reported earlier. Further, it appears that high neuroticism scores are more consistent feature of heroin addicts than deviation on extraversion. Also an attempt to uncover epidemiological factors underlying heroin addiction has been made.

Neuroleptic malignant syndrome and psychotic illness

A typical case of NMS and its successful treatment with bromocriptine is described. The authors noticed an inverse relationship between the process of recovery from NMS and the pre-existing psychotic illness.

Structural changes in the brain in schizophrenia a computed tomographic study

Computed tomography of the brain was performed in thirty schizophrenic patients in the age group of 19-45 years and thirty controls matched for age and sex The size of lateral ventricles, the width of the third ventricle and the sylvian fissure were measured in the CT scans. On group comparison, we found that the size of lateral ventricles expressed as ventricular brain ratio, and the width of the third ventricle and sylvian fissure were significantly greater in the schizophrenic patients (P< 0.001) as compared to the control group. No correlation was observed between the duration of illness and the cerebral findings. There was no significant difference between the group of schizophrenic patients with a history of having been treated with electro-convulsive therapy and the group without such a history.

A behavioural approach to the treatment of writer's cramp

In (perhaps) one of the largest series, treatment of 30 cases of writer's cramp by behaviour therapy alone, has been studied over a period of 5 years. The therapy techniques used were (i) relaxation therapy and retraining (ii) relaxation therapy, retraining and systematic desenetization. The outcome of both the techniques are very encouraging and show definite improvement in all cases. Various factors responsible for degree of improvement and the duration of treatment are discussed.

A repertory grid comparison of endogenous and neurotic depressions

The Repertory Grid Technique was used to study the construct systems of patients diagnosed as Endogenous and Neurotic Depressions. Twenty-five patients of each category were administered a Rank Order Repertory Grid comprising ten elements and fifteen constructs. The completed matrices were subjected to principal component analysis. Inter-element distance was used as the psychological measure to compare the two groups on characteristics like sell-ideal congruence, self-esteem, self-criticalness, degree of identification with parents, and the degree of temperamental and/or personality differences between parents as perceived by them. No significant differences between the two categories emerged on any of the dimensions referred to above. One striking observation in many grids was a tendency to isolate the element 'self'. Another observation was the difficulties some subjects had with a few elements and constructs probably due to cultural factors.

The repertory grid interview of a depressed patient

The construct system of a patient of Depression is investigated with the Rank Order Repertory Grid Technique, using principal component analysis to analyse the grid matrix. The investigation helps test clinical judgments and hypotheses concerning the patient and also suggests new directions for further clinical enquiry. This case study demonstrates how the grid technique can make possible a more comprehensive understanding of the cognitive processes of the patient.

A case of myoclonic epilepsy with unusual presentation

A case of stimulus-precipitated myoclonic jerks is presented. Besides spontaneous jerks, auditory, stimuli striking the palms, abdominal pressure or distension, evoked the jerks. Intermittent stroboscopic stimulation did not precipitate the attacks. The child had spontaneous recovery which is maintained, clinically and EEG wise for the last one year.