bluuebunny/crossref_metadata_2025 huggingface dataset:
Lymphocytic pneumonitis as the manifestation of acute graft‐versus‐host disease of the lung
Authors: Bolaños‐Meade Javier , Ioffe Olga , Hey Jamie C. , Vogelsang Georgia B. , Akpek Görgün
Published: May 2005

Acute graft‐versus‐host disease is a common complication after allogeneic stem cell transplantation. It normally affects the skin, liver, and gut. We report a 54‐year‐old male who developed shortness of breath, cough, and bilateral pulmonary infiltrates in which the work‐up failed to demonstrate an infectious etiology 165 days post‐HLA‐matched allogeneic peripheral blood stem cell transplant. Eighteen days before, his tacrolimus had been tapered and it was subtherapeutic on admission. A transbronchial biopsy showed a perivascular and interstitial lymphocytic infiltrate without evident pathogens on histology or extensive work‐up. The clinical picture was suggestive of pulmonary acute graft‐versus‐host disease. No disease was present elsewhere. Accordingly, the patient was treated with steroids and tacrolimus. After 12 hr on methylprednisolone, his symptoms disappeared with eventual resolution radiologically. Acute graft‐versus‐host disease of the lung is a very uncommon complication after stem cell transplant, but it should be considered in patients who are at high risk for graft‐versus‐host disease or developing symptoms soon after discontinuing immunosuppression. Its diagnosis requires work‐up to rule out an infectious etiology and a biopsy to confirm histology. Am. J. Hematol. 79:132–135, 2005. © 2005 Wiley‐Liss, Inc.
Therapy‐related myelodysplastic syndrome with monosomy 5 after successful treatment of acute myeloid leukemia (M2)
Authors: Ogasawara Toshie , Yasuyama Masako , Kawauchi Kiyotaka
Published: May 2005

We describe a patient who developed myelodysplastic syndrome over 2 years after achieving complete remission of acute myeloid leukemia (AML). The patient was treated in July 1998 with anthracycline, etoposide, and behenoyl cytarabine chemotherapy for AML (French‐American‐British classification, M2; World Health Organization classification, AML with maturation) and achieved complete remission. At presentation, no chromosomal abnormalities were detected. In December 2000, the patient's peripheral blood revealed pancytopenia, and his bone marrow was hypocellular with trilineage myelodysplasia and no blasts. Chromosomal analysis revealed complex karyotypic abnormalities, including monosomy 5. The patient was diagnosed with high‐grade myelodysplastic syndrome (MDS)/refractory anemia with excess blasts (RAEB) subtype. The pancytopenia progressed rapidly, and he died 2 months after the diagnosis of MDS. Therapy‐related MDS and AML (t‐MDS/t‐AML) developing after treatment for acute leukemia is unusual; the primary leukemia associated with most cases of t‐MDS/t‐AML is acute promyelocytic leukemia (APL). This unusual case suggests that AML excluding APL should be considered a primary hematologic malignancy for t‐MDS/t‐AML. Am. J. Hematol. 79:136–141, 2005. © 2005 Wiley‐Liss, Inc.
Leukemic relapse in the central nervous system after allogeneic stem cell transplantation with complete remission in the bone marrow and donor‐type chimerism: Report of two cases
Authors: Ohashi Haruhiko , Kato Chiaki , Fukami Shoko , Saito Hidehiko , Hamaguchi Motohiro
Published: May 2005

We studied two cases with leukemia that relapsed in the central nervous system (CNS) after allogeneic stem cell transplantation. One patient underwent peripheral blood stem cell transplantation (SCT) from a related, yet haplotype‐mismatched, donor for chronic myelomonocytic leukemia. She was kept in complete remission (CR) in the bone marrow (BM) for 7 months, until relapse in the cerebrospinal fluid (CSF) was evident. In the other patient, with acute lymphoblastic leukemia, systemic relapse occurred when he was still on immunosuppression 6 months after SCT from an unrelated donor. After induction chemotherapy following cessation of immunosuppression, the BM examination proved CR. During consolidation chemotherapy, however, he developed leukemic dissemination in the CSF, despite the fact that the BM was in CR. Chimerism status in the BM mononuclear cells and fractionated peripheral blood (PB) cells (granulocytes, T‐lymphocytes, and the others) was assessed by short tandem repeat analysis. In both patients, the BM cells and all the fractions of the PB cells proved donor‐type chimeras. These results seem to suggest that the graft‐versus‐leukemia effects might not be as effective in the CNS as in the BM, even when complete T‐lymphoid chimerism is achieved. Am. J. Hematol. 79:142–146, 2005. © 2005 Wiley‐Liss, Inc.
Human parvovirus B19 in patients with aplastic anemia
Authors: Mishra Baijayantimala , Malhotra Pankaj , Ratho Radha Kanta , Singh Mini P. , Varma Subhash , Varma Neelam
Published: May 2005

Aplastic anemia is characterized by pancytopenia with hypoplastic bone marrow. Various factors including viral infections have been implicated as the precipitating factors. Human parvovirus B19 has been associated with red‐cell aplasia, leukopenia, and thrombocytopenia. The present study was carried out to determine the role of parvovirus B19 in aplastic anemia patients. Twenty‐seven aplastic anemia patients and 20 healthy controls were tested for the presence of parvovirus B19 infection by detecting parvovirus B19‐specific IgM by ELISA and viral DNA by PCR. Parvovirus B19 IgM and viral DNA were detected in significantly higher numbers of patients in comparison to the controls (40.7% vs. 5%, P < 0.01; 37% vs. 0%, P < 0.001, respectively). The presence of parvovirus DNA in aplastic anemia patients indicates active or recent infection. However, more studies are needed to explore the mechanism of bone‐marrow aplasia due to human parvovirus B19 infection. Am. J. Hematol. 79:166–167, 2005. © 2005 Wiley‐Liss, Inc.
Survival role of protein kinase C (PKC) in chronic lymphocytic leukemia and determination of isoform expression pattern and genes altered by PKC inhibition
Authors: Alkan Serhan , Huang Qin , Ergin Melek , Denning Mitchell F. , Nand Sucha , Maududi Tazeen , Paner Gladell P. , Ozpuyan Fulya , Izban Keith F.
Published: May 2005

Recent studies have suggested that protein kinase C (PKC) activation plays an important role in survival of chronic lymphocytic leukemia (CLL). In order to characterize the role of PKC in CLL, we investigated the expression pattern of PKC isoforms in CLL cells (7 cases) and evaluated the effect of PKC inhibition on the survival of CLL cells (20 cases). Expression of the classical PKC isoforms β and γ, the novel isoform δ and the atypical isoform ζ was seen in all analyzed patient samples by Western blot analysis. Expression of the PKC isoforms α, ε, and ι was variable. Following incubation with the PKC inhibitor, safingol, CLL cells underwent marked apoptosis in all cases. In order to characterize the molecular events associated with the apoptotic effect of PKC inhibition, gene expression patterns in CLL cells were evaluated by cDNA‐microarray analysis. Following safingol treatment, several genes showed marked downregulation and PKC‐related proteins demonstrated decreased hybridization signals. Among these proteins, CREB and Daxx were further studied by using Western blotting, nuclear binding assay and confocal immunofluorescent microscopy. These studies showed significant inhibition of these proteins, consistent with the results of microarray gene analysis. Overall, these findings suggest that PKC activation is important for CLL cell survival and that inhibitors of PKC may have a role in the treatment of patients with CLL. Am. J. Hematol. 79:97–106, 2005. © 2005 Wiley‐Liss, Inc.
Hydroxyurea therapy for sickle cell disease in community‐based practices: A survey of Florida and North Carolina hematologists/oncologists
Authors: Zumberg Marc S. , Reddy Suresh , Boyette Robert L. , Schwartz Robert J. , Konrad Thomas R. , Lottenberg Richard
Published: May 2005

Little is known about patterns of hydroxyurea (HU) use by community‐based hematologist/oncologists (H/Os) for the treatment of sickle cell disease (SCD). Determination of these practice patterns pertaining to adult SCD patients was the focus of this study. A self‐administered survey was mailed to H/Os in two southeastern states. Replies were received from 70% of eligible physicians. This study focuses on responses from 184 community H/Os and a comparison group of 30 university‐based/affiliated H/Os providing ongoing care for at least 3 SCD patients/month. The majority of community H/O respondents saw less than 3 SCD patients/month. HU was prescribed by more than half (55%) of community H/Os in at least 10% of their patients. The most common reasons cited for prescribing HU include frequent painful crises (76%), chronic pain with frequent narcotic use (58%), and acute chest syndrome (43%). Although the majority of community H/Os care for few patients with SCD, the reported indications for HU were consistent with currently accepted recommendations. However, community H/Os reported acute chest syndrome, stroke, and pulmonary hypertension as indications for HU less often than the academic H/O group. Barriers to wider use of HU include physician concerns about carcinogenic potential, doubts about HU effectiveness, perceived patient apprehension about adverse effects, concern about lack of contraceptive use, and patient compliance. Further resources should focus on updating physicians on recently published material supporting the effectiveness of HU in symptomatic SCD as well as providing management guidelines to optimize the use of HU. Am. J. Hematol. 79:107–113, 2005. © 2005 Wiley‐Liss, Inc.
Durable molecular remissions with a single cycle of timed sequential consolidation chemotherapy in acute promyelocytic leukemia
Authors: Gore Steven D. , Smith B. Douglas , Gojo Ivana , Grever Michael , Kaufmann Scott H. , Letendre Louis , Leonard Debra G.B. , Marcucci Guido , Miller Carole B. , Morris Lawrence , Piantadosi Steven , Prior Thomas , Stock Wendy , Karp Judith E.
Published: May 2005

In a pilot study to reduce the duration of treatment and potential long‐term toxicities, 39 patients with acute promyelocytic leukemia in remission received a single cycle of intensive consolidation therapy, followed by intermittent ATRA maintenance. Consolidation therapy required prolonged hospitalization and was associated with a high incidence of mucositis (43% grade II or greater) and documented infection (45%). No deaths occurred during consolidation. Seven patients have relapsed; all other patients are in molecular remission (median follow‐up, 2.75 years). Kaplan–Meier estimate of 3 year disease‐free survival is 73% (95% confidence interval 55–91%). The relapse rate (0.06 relapses/patient‐year of follow‐up) is well within the range of larger published series that administer more prolonged consolidation. One patient has developed secondary myelodysplastic syndrome. These pilot data suggest that decreasing the total duration of consolidation chemotherapy did not compromise disease‐free survival for APL patients induced with ATRA/anthracycline and given intermittent ATRA maintenance. However, the toxicity of the consolidation module and the development of secondary myelodysplasia despite decreased total therapy emphasize the need to further improve and refine curative therapy for APL. Am. J. Hematol. 79:119–127, 2005. © 2005 Wiley‐Liss, Inc.
Ethnicity variables in the incidence rates of leukemias in New Zealand populations: Implications for stem‐cell transplantation
Authors: Tracey Mary Clare , Carter John M.
Published: May 2005

New Zealand has a population of 4 million people comprising four main ethnic groups: Caucasian (72.9%), New Zealand Maori (14.7%), New Zealand Pacific Islands people (5.6%), and Asians (6.3%). We examined 10 years of data (1993–2002) from the New Zealand Cancer Registry to determine if there are ethnic differences in leukemia incidence in New Zealand, and we relate this to availability of stem‐cell transplantation. We found that New Zealand Asians have a generally lower incidence of all leukemias investigated. New Zealand Maori have an increased risk of acute myeloid leukemia (RR 1.5 in the age group 25–49 and RR 1.31 in the age group 50–74), relative to New Zealand Caucasians. New Zealand Pacific Islanders have an increased risk of chronic myeloid leukemia (RR 2.13 in the age group 25–49 and RR 1.52 in the age group 50–74). Stem‐cell transplantation is a standard curative treatment for ages 25–49, and current opinion is extending the acceptable age up to age 60, in certain cases. We conclude that, among New Zealand Maori and New Zealand Pacific Islanders, there is an increased risk of acute myeloid leukemia and chronic myeloid leukemia in age groups suitable for stem‐cell transplantation. However, both of these ethnic groups have previously been shown to have a reduced chance of finding a 6/6‐matched unrelated donor on international registries. This leads to disproportionate provision of transplantation health care among the ethnic groups in New Zealand. Am. J. Hematol. 79:114–118, 2005. © 2005 Wiley‐Liss, Inc.
Modern management of respiratory failure due to pulmonary mycoses following allogeneic hematopoietic stem‐cell transplantation
Authors: Koldehoff Michael , Zakrzewski Johames L.
Published: May 2005

Pulmonary mycoses count among the most dangerous complications in allogeneic hematopoietic stem cell transplantation. Despite the establishment of antifungal chemoprophylaxis and empirical antifungal treatment, they frequently lead to respiratory failure and are still associated with an extraordinarily poor prognosis. However, the emergence of new antimycotics with alternative mechanisms of actions and decreased toxicity in combination with the development of new non culture‐based diagnostic techniques may allow earlier, more aggressive and more effective antifungal treatment approaches. In addition, the optimized use of new technologies designed to augment spontaneous breathing efforts by patients, mechanical ventilation, as well as the advantages of early tracheostomy lead us to expect better outcomes in the treatment of respiratory failure due to pulmonary mycoses following allogeneic hematopoietic stem cell transplantation. Am. J. Hematol. 79:158–163, 2005. © 2005 Wiley‐Liss, Inc.
Waldenström macroglobulinemia: A review of therapy
Authors: Gertz Morie A.
Published: May 2005

Waldenström macroglobulinemia is a rare monoclonal gammopathy‐associated lymphoplasmacytic lymphoma. Its incidence is only 4 per million per year. This review contains the known published literature specifically on the available management tools for Waldenström macroglobulinemia and is designed to assist clinicians in making management decisions for patients with this uncommon disorder. Am. J. Hematol. 79:147–157, 2005. © 2005 Wiley‐Liss, Inc.
Congenital methemoglobinemia caused by Hb‐MRatnagiri (β‐63CAT→TAT, His→Tyr) in an Indian family
Authors: Kedar Prabhakar S. , Nadkarni Anita H. , Phanasgoankar Supriya , Madkaikar Manisha , Ghosh Kanjaksha , Gorakshakar Ajit C. , Colah Roshan B. , Mohanty Dipika
Published: May 2005

Hb‐M is a very rare hemoglobinopathy in the Indian subcontinent. We report a family with Hb‐M with lifelong cyanosis from the Ratnagiri district in western India. The propositus was a 11‐year‐old female child with a history of increasing cyanosis exacerbated by fever and weakness. Similar complaints were also noted in her mother and five maternal family members. There was no history of cardiac illness or exposure to drugs and chemicals. The methemoglobin level was 39.3% in the propositus and 21.1% in her mother with normal NADH‐methemoglobin reductase activity. Abnormal absorption peaks by spectroscopic analysis, presence of hemoglobin instability, and a slow‐moving band on starch gel electrophoresis supported the presence of Hb‐M. Automated DNA sequence analysis of the β globin gene showed a C→T substitution at codon 63. This leads to a substitution of histidine (CAT) by tyrosine (TAT) at the β 63 (E7) position, similar to Hb‐M Saskatoon. We have named this variant as Hb‐MRatnagiri. Am. J. Hematol. 79:168–170, 2005. © 2005 Wiley‐Liss, Inc.
The preparation of (Al2O3)x(SiO2)y thin films using [al(OSiEt3)3]2 as a single‐source precursor
Authors: Landry Christopher C. , Cheatham Linda K. , Macinnes Andrew N. , Barron Andrew R.
Published: May 2005

Amorphous (Al2O3)x(SiO2)y thin films have been grown by atmospheric pressure metal‐organic chemical vapour deposition using the single‐source precursor [Al(OSiEt3)3]2. Characterisation by X‐ray photoelectron spectroscopy indicated that the films consisted of a mixture of Al2O3, SiO2 and an aluminosilicate. The relative amount of each species was dependent on the deposition temperature and the carrier gas composition. Use of NH3 as the carrier gas resulted in the increased volatility of the precursor by the in situ formation of the low‐melting Lewis acid–base adduct Al(OSiEt3)3(NH3); however, no nitrogen incorporation was observed in these deposited films.
Electrical breakdown and recovery in rectifying m | lb | m structures
Authors: Martin A. S. , Sambles J. R. , Ashwell G. J.
Published: May 2005

Metal 1 | C16H33–Q3CNQ LB film | metal 2 structures exhibiting asymmetric, non‐linear I/V characteristics have been fabricated using the Langmuir–Blodgett (LB) technique with LB film thicknesses as small as a single monolayer. When such junctions are subjected to low biases, the I/V traces exhibit little or no asymmetry, but as the applied biases increase, so the I/V asymmetry becomes more evident. The largest applied voltages before breakdown are of the order of 1 V, which represents an E‐field of order 108 V m−1. This breakdown under high biases increases the junction conductance and the I/V traces become very noisy. More interestingly, it has been observed that after such breakdown it is possible for the junction to recover on reduction of the bias. It is observed that recovery is not always immediate and may require several voltage sweeps. A subsequent increase in bias will cause breakdown at the same bias as the first breakdown, indicating that no permanent damage has been caused.
Cathodoluminescence wavelength imaging for spatial mapping of excitons bound to dislocations and structural defects in cds
Authors: Hoffmann A. , Christen J. , Gutowski J.
Published: May 2005

By means of the unique technique of cathodoluminescence wavelength imaging we analyse the distribution and nature of dislocations in strain‐distorted CdS by scanning the spatial pattern of a set of lines due to excitons bound to dislocation‐related defects. The method is demonstrated to be most powerful for the study of dislocations in II–VI and other materials which play a crucial role in hetero‐epistructures.
Reactions of GaX3 (x  br, i) with AS(SiMe3)3; crystal structures of I3Ga · as(SiMe3)3 and [I2GaAS(sime3)2]2
Authors: Johansen James D. , McPhail Andrew T. , Wells Richard L.
Published: May 2005

Reactions of GaX3 (X  Br, I) with As(SiMe3)3 in 1:1 and 2:1 mole ratios were investigated. For the latter reactant stoichiometry, substances having the empirical formulae AsBr3Ga2 (1) and Asl3Ga2 (2), the analogues of the previously reported single‐source GaAs precursor (AsCl3Ga2)n, were isolated as yellow isolated as yellow insoluble powders. Low‐temperature reactions in a 1:1 mole ratio resulted in the isolation of the adducts Br3Ga.As(SiMe3)3 (3) and I3Ga.As(SiMe3)3 (4). On the other hand, at room temperature the GaBr3 reaction resulted in a complex mixture from which no characterizable compounds were isolated, whereas the Gal3 reaction afforded the crystalline compound [I2GaAs(SiMe3)2]2 (5). The structures of 4 and 5 were elucidated by complete single‐crystal X‐ray analysis (crystal data: 4, monoclinic, space group P21/c, a = 16.497(2) Å, b = 9.629(1) Å, c = 16.658(2) Å, β = 113.21(1)°, V = 2432(1) Å3, Z = 4; 5, orthorhombic, space group Pbca, a = 14.279(2) Å, b = 17.509(2) Å, c = 13.818(2), Å, V = 3455(1) Å3, Z = 4).
Mesomorphic stilbazole complexes of silver(I) with triflate and nitrate counter‐anions
Authors: Bruce Duncan W. , Dunmur David A. , Hudson Sarah A. , Maitlis Peter M. , Styring Peter
Published: May 2005

Reaction of AgX (X  NO3 or CF3SO3) with two equivalents of 4‐alkyloxystilbazole leads to the mesomorphic silver(I) complexes [Ag(n‐OPhVPy)2] [X] in high yield. The long‐chain homologues of each series show SA and SC mesophases, while for shorter chain lengths the nitrate salts show only an SA phase and the triflate salts only a nematic phase. The phase behaviour of these new complexes is discussed in relation to analogous complexes with different counter‐anions or ligands.
Characterization of ZnS grown by metal‐organic chemical vapour deposition on GaAs(100) using t‐butyl mercaptan and dimethylzinc
Authors: Armitage D. N. , Yates H. M. , Williams J. O. , Cole‐hamilton D. J. , Patterson I. L. J.
Published: May 2005

ZnS has been grown on GaAs(100) substrates by atmospheric pressure metal–organic chemical vapour deposition (MOCVD) using dimethylzinc (DMZn) and t‐butyl mercaptan (t‐BuSH). The effects of the reactant gas phase molar ratio and the growth temperature on the characteristics of the material grown have been investigated. The structural quality of the layer is demonstrated by X‐ray rocking curve half‐widths of less than 300 arcsec for the epilayers. There is little significant pre‐reaction and the layers are of excellent surface morphology and layer uniformity.
Excimer laser projection etching of copper foils in chlorine gas
Authors: Dyer P. E. , Greenough R. D. , Key P. H.
Published: May 2005

Low‐fluence XeCl laser etching of copper foils in a chlorine environment has been studied. The etch rate is fluence‐dependent in the range 0.05–1.0 J cm−2 and is governed by the growth characteristics of the chloride layer formed in the interpulse period. Projection etching with good pattern reproduction and resolution for high‐aspect‐ratio features is demonstrated.
Metal–Organic chemical vapour deposition (mocvd) growth utilising cu(acac)2 (acac  pentane‐3, 5‐dionato) as a source for copper‐containing materials: Influence of carrier gas on surface morphology
Authors: Rees William S. , Caballero Celia R.
Published: May 2005

The unsubstituted bis‐β‐diketonato complex of copper, Cu(acac)2 (acac  pentane‐3, 5‐dionato), has been used to deposit both elemental copper and copper oxide thin films by metal–organic chemical vapour deposition (MOCVD). For all Cu(II) bis‐β‐diketonates, growth of oxygen‐free layers requires the breakage of four copper–oxygen bonds present in the precursor. The influence of carrier gas composition on deposit morphology has been examined for six parameter sets: both hydrous and anhydrous streams, each for reducing (H2), inert (Ar) and oxidising (O2) environments.
Theory of molecular optoelectronics. X: Calculations for MBANP and NMBA
Authors: Munn R. W. , Smith S. P. B.
Published: May 2005

Components of the crystal quadratic susceptibility tensor x(2) for second‐harmonic generation are calculated for the title compounds 2‐(α‐methyl benzylamino)‐5‐nitropyridine (MBANP) and 4‐nitro‐4'‐methyl(benzylidene aniline) (NMBA). Input data are the crystal structure and refractive indices and CNDO hyperpolarizabilities. The calculations also yield effective polarisabilities and local electric fields. Susceptibility components reach 66 pm V−1 in MBANP and 27 pm V−1 in NMBA in the crystal axes; agreement with experiment is poor for MBANP but satisfactory for NMBA. These features seem to reflect the better defined charge transfer axis in NMBA. Screened dipole–dipole interactions calculated from CNDO dipole moments stabilise MBANP by 70 kJ mol−1 and NMBA by 20 kJ mol−1 and imply permanent electric fields of a few GV m−1.
Hole transport in p‐diethylamino‐benzaldehyde‐diphenyl hydrazone
Authors: Borsenberger P. M.
Published: May 2005

Hole mobilities have been measured in vapour‐deposited films of p‐diethylamino‐benzaldehyde‐diphenyl hydrazone (DEH). The results are described by a model based on hopping through a manifold of sites broadened by energetic and positional disorder. The application of the model leads to the conclusion that the width of the density of hopping states is influenced by dipolar disorder due to dipole moments of the DEH molecules. In comparing the results with those observed in other molecular solids, the degree of positional disorder is shown to be relatively small.
Stable and volatile β‐diketonate complexes of copper, calcium, strontium, barium and yttrium for use as chemical vapour deposition precursors
Authors: Thompson Simon C. , Cole‐hamilton David J. , Gilliland Douglas D. , Hitchman Michael L. , Barnes John C.
Published: May 2005

The new β‐diketone 1,1,1,2,2,3,3,7,7,8,8,9,9,9‐tetradecafluorononane‐4,6‐dione (HTDFND) has been prepared and employed in the formation of complexes of Cu, Ca, Sr, Ba and Y. Complexes of the same metals derived from the β‐diketone 1,1,1,2,2,3,3,7,7,7‐decafluoroheptane‐2,4‐dione (HDFHD) have also been prepared. In general the compounds have the formula [M(TDFND)2H2O] or [M(DHFD)2H2O], although the yttrium complexes are [Y(β‐diket)3] · xH2O (β‐diket ≡ TDFND (x = 3) or DFHD (x = 2)). The complexes have been characterised by analytical and spectroscopic means and by a crystal structure of [Cu(TDFND)2EtOH] obtained by recrystallisation of [Cu(TDFND)2H2O] from aqueous ethanol. Crystal data for [Cu(TDFND)2EtOH]: triclinic, P̄1, a = 11.249(4) Å, b = 12.331 (2) Å, c = 12.890(2) Å, α = 96.89(2)°, β = 108.93(3)°, γ = 109.63(3)°, V = 1541.54 Å3, Z = 2. The complex is square pyramidal with the four oxygen atoms of the β‐diketonates occupying the basal sites and the oxygen atom of the co‐ordinated ethanol molecule in the apical position. The C3F7 ligands take up an extended staggered configuration in order to minimise steric repulsions. The complex is monomeric with intermolecular distances all greater than 4 Å. Simultaneous thermal analysis at 1 atm reveals that all the compounds lose water but then sublime, usually completely without decomposition. [Ba(TDFND)2H2O] is the first barium complex for which this is the case and it can be dehydrated to give [Ba(TDFND)2], which is also volatile but becomes less volatile with time. [Ba(TDFND)2H2O], [Sr(TDFND)2H2O] and [Ca(DFHD)2H2O] are suitable precursors for the growth of MF2 on silicon substrates. Complete orientation in the (111) direction is observed. Changes in the film growth rate with time for all the precursors are attributed to sample decomposition ([M(DFHD)2H2O], M ≡ Ca or Sr) or to slow reorganisation of the crystal structure ([Ba(TDFND)2H2O]). Layers with Y:Ba:Cu ratios close to the required 1:2:3 have been grown using [Y(DPM)3], [Cu(DPM)2] and [Ba(DFHD)2H2O] (DPM ≡ 2,2,6,6‐tetramethylheptane‐3,5‐dionato).
Room temperature synthesis of copper indium diselenide in non‐aqueous solution using an organoindium reagent
Authors: Hepp Aloysius F. , Andras Maria T. , Bailey Sheila G. , Duraj Stan A.
Published: May 2005

Reaction of triscyclopentadienylindium with cuprous selenide in 4‐methylpyridine at 25°C produces polycrystalline copper indium diselenide.
Oriented purple membrane multilayers of halobacteria fabricated by langmuir–blodgett and electrophoretic sedimentation techniques
Authors: Maximychev A. V. , Kholmansky A. S. , Levin E. V. , Rambidi N. G. , Chamorovsky S. K. , Kononenko A. A. , Erokhin V. V. , Checulaeva L. N.
Published: May 2005

Organised films containing oriented patches of purple membranes and consisting of 15–75 layers and approximately 1000 layers were fabricated by the Langmuir–Blodgett and electrophoretic sedimentation techniques respectively. ‘Surface pressure vs. molecular area’ isotherms for monolayers of purple membranes suspended in hexane and deposited on the air/water interface were studied. Circular dichroism and absorption spectroscopy were used to investigate the effect of an organic solvent on the chromophore binding site in the purple membranes. Kinetic methods based on flash excitation were employed to determine the influence of the film deposition conditions on the photoelectric response of bacteriorhodopsin and on the M412 intermediate relaxation. Structural characteristics for multilayers prepared from water and hexane purple membrane suspensions were determined by low‐angle X‐ray scattering. The influence of the layer deposition conditions on the electrical, physical and photoelectrical properties of ordered structures containing bacteriorhodopsin is discussed.
SnSSno2 conversion of chemically deposited SnS thin films
Authors: Nair P. K. , Nair M. T. S. , Campos J. , Sanchez A.
Published: May 2005

The thermal decomposition of chemically deposited SnS thin films to SnO2 films by air annealing at temperatures up to 400°C is discussed. The conversion of a 0.7 μm thick SnS thin film to an SnO2 film involves the creation of non‐stoichiometric SnS, SnS + SnS2 mixed phase and non‐stoichiometric SnO2 (i.e. SnO2  x), as concluded from X‐ray diffraction patterns, optical transmission spectra and electrical characteristics. The SnO2 thin films obtained in this manner are photoconductive, with a lowest sheet resistance (in the dark) of about 105 Ω/□ and an activation energy (Ea) of 0.1 eV for the electrical conductivity observed for the SnS films annealed at 325°C. This was found as the onset temperature for conversion of the SnS + SnS2 phase to the non‐stoichiometric SnO2 – x film. Elevation of the annealing temperature to 400°C results in an elevation of the sheet resistance to about 109 Ω/□ with the value of Ea at 1.3 eV, indicating an improvement in the degree of stoichiometry.
A new gas alarm device and integrated‐electrode‐type chemical sensor
Authors: Liu Jun , Weppner Werner
Published: May 2005

A new gas alarm is presented which is based on solid electrolytes with high ionic conductivities. The operating principle of the device is the compensation of the cell voltage and measurement of the direction of the electrical current. Also, the general microelectronic circuit designs are discussed. Several advantages are found in comparison with other types of gas sensors.
Instability in electrical performance of organic semiconductor devices
Authors: Ostoja P. , Guerri S. , Impronta M. , Zabberoni P. , Danieli R. , Rossini S. , Taliani C. , Zamboni R.
Published: May 2005

A field effect transistor (FET) has been fabricated with the hexamer of thiophene (α‐sexithienyl) in order to assess the performance of such electronic devices based on an organic material. Particular emphasis has been given to the determination of the origin of the instability in the electrical performance. From this study it is confirmed that charged species, possibly chemical impurities present in the processed material, can migrate through the film under an applied electric field, even at room temperature.
Microelectrode array device: Photolithographic fabrication and electrochemical characterisation
Authors: Dobson P. J. , Jiang L. , Leigh P. A. , Hill H. A. O. , Kaneko S.
Published: May 2005

A new type of microelectrode array device has been developed using semiconductor‐processing techniques. An array of 15 × 15 square electrodes as small as 1 μm, spaced 100 μm apart, has been fabricated on a silicon chip of dimensions 1.5 × 1.5 mm2. Steady state electrochemistry was performed using these devices in both aqueous and non‐aqueous media.
Metal sulphide thin film photography with lead sulphide thin films
Authors: Nair P. K. , Gomezdaza O. , Nair M. T. S.
Published: May 2005

Metal sulphide thin film (MSTF) photography based on photo‐accelerated chemical deposition (PACD) of PbS thin films is described. Here an intensity distribution over the surface of a growing PbS thin film produces a thickness variation (0.06–0.15 μm) of the film which, when viewed under daylight, yields a specularly reflective image. Under 800 W m−2 of solar radiation a bluish MSTF photographic image (0.15 μm film thickness) on a coppery‐bronze background (0.08 μm) is obtained in the PACD of PbS at the end of 25 min deposition when a high‐contrast photographic negative is used as the object. The best contrast of 0.46 in the PbS MSTF photography in the reflection mode is obtained under the above condition of exposure when the optical transmission in a photographic negative in the image area is ∽30% and that in the background is ∽1%. The contrast available in the transmission mode in the MSTF photographic image is considerably less: ∽0.28 (maximum) for optical transmission of 1% and 100% in the background and image areas of the photographic negative respectively.
Three‐Centre electron transfer as a frame for molecular switch phenomena
Authors: Hammerstad‐pedersen Ja N. M. , Kharkats Yurij I. , Sommer‐Larsen Peter , Ulstrup Jens
Published: May 2005

Molecular three‐centre electron transfer (ET) systems contain an intermediate electronic bridge group state in addition to the donor and acceptor states. This feature is encountered in long‐range ET patterns of metalloproteins, in bacterial photosynthetic reaction centres, in electrochemical processes at modified metal electrodes and in hypothetical or real molecular shift register and photodiode device‐like systems. Overall ET is by superexchange when the intermediate group energy is high. When the energy is low enough that the state is temporarily populated, a range of vibrational features arise depending on the vibrational coupling and relaxation time of the intermediate state. In external fields these properties induce characteristic ‘switch’ effects reflected in rapid changes in the current derivatives and other features in the current–voltage relations. We provide a quantum mechanical frame for three‐centre ET in such molecular systems. The theory rests on second‐order perturbation theory. In contrast to most applications of superexchange concepts, the theory includes explicitly nuclear coupling in the intermediate state and is valid both for high energy superexchange and for low‐energy populated intermediate states. Moreover, mild, finite resonances arise in the transition regions between the various energy ranges represented by analytical rate constants. The theory is appropriate to the molecular electronic behaviour of several biological and synthetic three‐level ‘switch’ ET systems.
A rheological semiconductor
Authors: Bullough W. A.
Published: May 2005

The concept of high‐speed control of a mechanical process via electrical modulation of the flow of some kind of hydraulic cum semiconductor liquid is introduced. This is done in order to stimulate activity towards the provision of improved power transmission media for use in the formulation of intelligent tools and systems. A quantum leap in machine performance is the aim; flexibility of operation and motion‐switching speeds 10 times higher than presently available are in demand. Some information is given on the background and application aims of the concept. Brief state‐of‐the‐art information is presented on the front‐runner of enabling solutions to this industrial equivalent of recent innovations in information technology—the electrorheological fluid.
Compensation phenomena by ion implantation doping of an electroactive polymer, poly(para‐phenylene)
Authors: Le hüe C. , Moliton A. , Lucas B. , Froyer G.
Published: May 2005

We have shown that poly(para‐phenylene) (PPP) can be obtained either n‐type or p‐type by ion implantation at low energy (E ≦ 50 keV); PPP is primarily an insulator pellet obtained from compacted powder synthetised by the Kovacic method. To compare with the chemical doping effect, we have studied the conductivity and thermopower of PPP samples after two successive ion implantations with Cs+ and I+.

The experimental results show that we clearly obtain reversible doping only in the case of an initially I+‐doped sample: the thermopower sign is changed after a Cs+ implantation with a fluence equal to 3 × 1014 ions cm−2. In the other case (Cs+ initial implantation) we observe the change in thermopower sign at higher fluence (2 × 1016 I+ ions cm−2). This last effect can be attributed to a metal transition induced by the accumulation of defects in the material because of too high implantation parameters (graphitisation).
Delayed luminescence in a molecularly doped polymer (TAPC in polycarbonate)
Authors: Hensel K. , Bässler H.
Published: May 2005

Decay of the delayed luminescence of 1,1‐bis(di‐4‐tolylaminophenyl)cyclohexane, both doped into a polycarbonate binder and matrix‐isolated in an MTHF glass, has been studied upon excitation with the 308 nm line of an excimer laser. Time‐resolved emission spectra have also been recorded. In the early time regime, 30 ns < t < 10 μs, the decay of the emission, identified as delayed fluorescence rather than phosphorescence, follows a power‐law characteristic of geminate pair recombination in a disordered medium. Singlet–singlet excitation fusion is considered to be the main pathway for geminate pair formation. Fusion of triplet excitations becomes important for e–h pair formation at long times only (10 μs < t < 10 ms). The rate of triplet–triplet encounters carries a time dependence characteristic of the random walk of excitations in a disordered solid.
The characterisation of GaAs on silicon using polarised laser light
Authors: Morris I. L. , Jenkins T. E. , Goodes S. R.
Published: May 2005

MBE‐grown gallium arsenide epitaxial layers on silicon, with thicknesses between 0.1 and 8.1 μm, have been studied using a simple rotating polariser multiple‐angle‐of‐incidence ellipsometer. From these data, information on the roughness of the surfaces of the layers and the anisotropy of the refractive index of the layers has been obtained. The results are compared with data obtained on the same samples using scanning electron microscopy and conventional spectroscopic ellipsometry.
Development of lithographic techniques for metallisation of organic substrates
Authors: Gilmour Sandra , Kershaw Stephen V. , Pethrick Richard A. , Pantelis Philip , Cassidy Steven , Sherwood John N.
Published: May 2005

A wide range of applications which involve organic crystalline materials require the metallisation of low‐molecular‐weight compounds. Conventional lithographic techniques used in silicon fabrication technology use high‐temperature processing methods which are unsuitable for organic materials. Gold/titanium bilayer and shadow‐masking techniques were found to provide suitable solutions to the problem of metallisation of these materials and allowed fabrication of a surface acoustic wave (SAW) device with (–)‐2‐α‐methylbenzylamino‐5‐nitropyridine (MBANP) as substrate.
Peculiarities of silicon carbide crystal growth under the diffusion mechanism of vapour transfer
Authors: Lilov S. K. , Yanchev I. Y.
Published: May 2005

In the present work the gas dynamics in the growth zone of SiC crystals is investigated. It is shown that the propagation of SiC vapour from the growth cavity walls towards the lids is effected by diffusion. On this basis the calculation of the concentration distribution of SiC vapour (n), the equilibrium vapour concentration (ns) and the supersaturation (α = [(n – ns)/ns] × 100%) in the crystal growth zone at different radial and axial gradients is carried out by solving the Laplace equation in cylindrical co‐ordinates for a stationary case corresponding to the conditions of crystal growth. The results obtained are compared with the available experimental data, which gives the possibility of explaining some of the observed peculiarities during SiC crystal growth from the vapour phase by the sublimation method.
The influence of bath composition on the photocurrent response and morphology of chemically deposited CdS thin films
Authors: Sebastian P. J. , Nair P. K.
Published: May 2005

The influence of the chemical bath composition on the photocurrent response, film morphology and optical transmittance of chemically deposited CdS thin films is reported. The bath parameters such as concentrations of triethanolamine, thiourea, ammonia and cadmium acetate and the bath temperature controlled the photosensitivity, photocurrent decay, morphology and optical transmittance of the films. The optimum concentration of the bath for getting good‐quality photosensitive films with good optical transmittance was identified in this investigation.
A theoretical study of the hyperpolarisabilities of nickel dithiolene molecules
Authors: Craig B. I. , Williams G. R. J.
Published: May 2005

The hyperpolarisabilities γ of nickel dithiolene complexes have been calculated by the finite field method in combination with the CNDO/S molecular orbital method. This computational technique, which has been developed for calculating the polarisation of large organic molecules by a perturbing electric field, is discussed. The changes in γ that occur as a result of different selections of substituent groups in the dithiolene ligand are described. The results are compared with recent experiments investigating these types of molecules. Large values for γ are found to arise from the interaction of the nickel 3d electrons with the conjugated π‐electrons of the metal–ligand complex.
Metal–Organic chemical vapour deposition of polycrystalline tetragonal indium sulphide (InS) thin films
Authors: Maclnnes Andrew N. , Cleaver William M. , Barron Andrew R. , Power Michael B. , Hepp Aloysius F.
Published: May 2005

The dimeric indium thiolate [(tBu)2In(μ‐StBu)]2 has been used as a single‐source precursor for the metal–organic chemical vapour deposition (MOCVD) of InS thin films. The dimeric In2S2 core is proposed to account for the formation of the non‐equilibrium high‐pressure tetragonal phase in the deposited films. Analysis of the deposited films has been obtained by transmission electron microscopy (TEM), with associated energy‐dispersive X‐ray analysis (EDX) and X‐ray photoelectron spectroscopy (XPS).
Second‐Order optical non‐linearities of {4‐(dimethylamino) stilben z & e 4'‐yl} dimesityl borane
Authors: Lequan Minh , Lequan Rose Marie , Chane‐ching Kathleen , Callier Anne‐claude , Barzoukas Marguerite , Fort Alain
Published: May 2005

Samples of {4‐(dimethylamino) stilben Z & E 4'‐yl} dimesityl borane (BNS) were synthesised and investigated for their non‐linear optical properties. The results show that the quadratic hyperpolarisability of the Z‐isomer is smaller than that of the E‐isomer, the beta value found for the latter being as high as 60 × 10−30 esu.
An investigation of LPCVD and PECVD of in situ doped polycrystalline silicon for VLSI
Authors: Ahmed Waqar , Ahmed Ejaz
Published: May 2005

In general, high‐temperature processes cause thermal stresses and diffusion of dopants, resulting in reduced device yields. It is thus desirable to reduce the number of high‐temperature steps and the use of an in situ doping technique eliminates one such step. In this investigation, low‐pressure chemical vapour deposition (LPCVD) and plasma‐enhanced chemical vapour deposition (PECVD) have been utilised to deposit in situ doped polycrystalline silicon films. The process characteristics and properties such as spreading resistance, grain structure, etch rate using a plasma and dopant concentrations of these films have been investigated and explained using a simple model for dopant activation and grain growth. It is shown that good‐quality films suitable for VLSI can be produced.
Electrochemical synthesis of electroactive polyaniline in organic solutions
Authors: Pasquali M. , Pistoia G. , Rosati R.
Published: May 2005

Polyaniline films have been grown in solutions based on acetonitrile or acetonitrile/nitromethane mixtures by galvanostatic, potentiostatic and cyclic voltammetry techniques. LiClO4 or anilinium tetrafluoborate was used as a salt. With the latter, aniline was absent in some tests, since anilinium could act simultaneously as a charge carrier and a polymerising species. The film characteristics have been evaluated by cyclic voltammetry, impedance spectroscopy and SEM experiments. It has been found that the protons released by aniline (following oxidation) or anilinium can be made available to the g| wing chains if the protophilic character of the solvent is sufficiently low. In a 1/1 acetonitrile/nitromethane mixture the galvanostatic and potentiostatic techniques produce electroactive films of reduced resistance, especially if anilinium tetrafluoborate is present. These seem to be the best conditions for the synthesis.
Stability of electrochemically prepared polyaniline films in aqueous and organic solutions
Authors: Pasquali M. , Pistoia G. , Fiordiponti P.
Published: May 2005

Electroactive polyaniline films have been grown by galvanostatic, potentiostatic and cyclic voltammetry techniques in organic solutions based on LiClO4 or anilinium tetrafluoborate as salts and acetonitrile or acetonitrile/nitromethane mixtures as solvents. After storage of these films in a 1 M H2SO4, Na2SO4 aqueous solution, their stability was tested by cyclic voltammetry and impedance spectroscopy in this solution. Different levels of retention of the anodic charge have been found depending on the electrochemical technique and preparation solution. The impedance tests have revealed limited changes in the charge transfer resistance upon storage. This has been interpreted on the basis of a limited deactivation of the films, which in some cases would instead experience physical changes. Confirmation of this assumption was obtained via an SEM experiment.

Films prepared by cyclic voltammetry in the above acidic solution and stored in acetonitrile‐or propylene‐carbonate‐based electrolytes show major degradation processes, as evidenced by the appearance of quinone‐like compounds and the marked increase in the charge transfer resistance.

Finally, films prepared by different electrochemical techniques in acetonitrile‐based solutions and stored in LiClO4‐acetonitrile reveal moderate degradation phenomena.
Chemical sensing by an electrical oscillator: Detection and quantification of cationic surfactants
Authors: Nakata Satoshi , Yoshikawa Kenichi , Shima Osamu , Terada Hiroshi
Published: May 2005

A new chemical sensing system using an electrical oscillator has been developed. This sensing system measures the electrical ‘non‐linearity’ at the surface of an electrode immersed in a test solution: a sinusoidal voltage is applied to the electrode and the higher harmonics of the output current are obtained by Fourier transformation. This sensing system has been used to detect and quantify surfactant molecules in solutions. The relative intensity P2/P1 of the peaks of the second (P2) and first (P1) harmonics in the output current was found to be linearly correlated with the logarithms of the concentrations of cationic surfactants such as cetylpyridium bromide (CPB) and cetyl‐N,N,N‐trimethylammonium bromide (CTAB), but not with those of the anionic surfactant sodium dodecyl sulfate (SDS) or the neutral surfactant Triton X‐100. The reproducibility of this sensing system was shown to be excellent.
Mass spectrometric study of laser‐induced pyrolytic decomposition of TMA
Authors: Ivanov B. , Popov C. , Shanov V.
Published: May 2005

The composition of the gaseous phase during pyrolytic laser‐induced chemical vapour deposition (LCVD) of aluminium from trimethylaluminium (TMA) was determined. The analysis was carried out in situ by means of a quadrupole mass spectrometer (QMS) in a closed reaction cell. The decomposition of the aluminium alkyl was induced by a copper bromide vapour laser on the surface of (111) silicon monocrystalline wafer at 0.22 GW m−2 average power density, 120 μm s−1 scanning speed and 100 Pa (1 mbar) partial pressure of TMA. The detected gaseous products of the pyrolysis of TMA were ethane, ethylene, methane and hydrogen. The presence of ethane and ethylene was probably due to the unconventional way of decomposition caused by pulsed laser irradiation. The mass peak dynamics of the created pyrolytic products at m/e = 28, 16 and 2 indicated significant production of ethane + ethylene, methane and hydrogen in the ratio 1:5:1.75.
Liquid crystalline siloxanes containing spiropyran chromophores as reversible optical data storage materials
Authors: Natarajan L. V. , Tondiglia V. , Bunning T. J. , Crane R. L. , Adams W. W.
Published: May 2005

The application of liquid crystalline siloxanes consisting of pentamethylhydrocyclosiloxane cores with attached cholesteryl‐, biphenyl‐ and photochromic spiropyran‐based mesogens as reversible optical data storage materials is demonstrated by grating formation with an argon ion laser beam operating in the UV and visible regions. Erasure of the gratings with heat or visible radiation was possible.