bluuebunny/crossref_metadata_2025 huggingface dataset:
Human Antiganglioside Autoantibodies: Validation of ELISA
Authors: RAVINDRANATH MEPUR H. , MUTHUGOUNDER SAKUNTHALA , SARAVANAN THIRUVERKADU S. , PRESSER NAFTALI , MORTON DONALD L.
Published: July 2005

Abstract: Gangliosides have a hydrophilic sugar chain that contains antigenic determinants and a hydrophobic ceramide. In humans, gangliosides elicit a T‐cell independent IgM response; antiganglioside IgM autoantibodies may be pentameric or polymeric. A correlation between specific neuropathies and antiganglioside autoantibodies has been confirmed. Although many neurologists attempt to lower titers of antiganglioside autoantibodies, oncologists are developing strategies to augment production of IgM antibodies that will remove immunosuppressive gangliosides from the circulation of patients and target gangliosides and kill tumor cells. Antiganglioside IgM antibodies can cause leakage of the blood‐nerve barrier in a concentration‐dependent and complement‐independent manner, bind to neuronal gangliosides to create a neuromuscular block and serve as a marker of axonal damage in neuropathies such as multiple sclerosis. They are also a promising biomarker of early prostate cancer. There is a need to validate the protocol for enzyme‐linked immunosorbent assay (ELISA) of antiganglioside IgM autoantibodies. This validation must consider the purity of gangliosides from different commercial sources, the coating of gangliosides onto a solid matrix in a manner that maximizes exposure of oligosaccharide epitopes to IgM paratopes, techniques to minimize background noise and eliminate nonspecific antibody binding, and carefully defined positive and negative controls. The validated protocol also must include a simple formula to estimate titers for several replicas. Finally, antibody titers must be converted to natural logs for statistical appraisal.
Identification of Thrombin Antibodies in Patients with Antiphospholipid Syndrome
Authors: MIESBACH WOLFGANG , MATTHIAS TORSTEN , SCHARRER INGE
Published: July 2005

Abstract: Venous or arterial thrombosis, abortion, and the presence of antiphospholipid antibodies (aPL) define the criteria for the antiphospholipid syndrome (APS). A heterogeneous group of antibodies against phospholipids and plasma proteins may influence several coagulation pathways and lead to thrombophilia. We investigated the presence of antibodies to thrombin (Thr) in patients with aPL and reviewed their clinical manifestations. IgG and IgM titers of aPL were measured by ELISA (Aesku.Diagnostics, Wendelsheim, Germany). Lupus anticoagulants (LA) were measured according to the criteria of the Scientific and Standardization Committee of the International Society on Thrombosis and Haemostasis. One hundred twenty patients were identified with LA or anticardiolipin (aCL). Of the 120 patients, 98 (82%) had primary APS and 22 (18%) had secondary APS. Further, 76/120 (63%) were suffering from thromboembolic manifestations, mostly venous thrombosis. Anti‐thrombin‐IgG was detected in 20%, and anti‐thrombin‐IgM was detected in 23% of the patients. The presence of anti‐thrombin antibodies was closely related to the presence of anti‐β2‐glycoprotein‐I (β2‐GP‐I) (96%), aCL (97%), and LA (87%), and less well to the presence of anti‐phosphatidylserine/prothrombin /Ser/Pro) antibodies (71%) or anti‐prothrombin antibodies (Pro) (50%). Sixty‐seven percent of the patients with anti‐Thr‐IgG suffered from thromboembolic complications, mostly arterial thrombosis. The rate of thrombosis was higher for these patients than for patients with anti‐β2‐GP‐I antibodies (37/60, 62%), LA (50/79, 63%), or anti‐Ser/Pro antibodies (18/28, 64%). Anti‐thrombin antibodies were found in 20% of patients with aPL; 67% of these patients were admitted with thrombotic manifestations of APS. The presence of anti‐thrombin antibodies was closely associated with the presence of aCL and anti‐β2‐GP‐I antibodies. The sensitivity of the test for anti‐thrombin antibodies for the diagnosis of APS was higher than the sensitivity of the anti‐prothrombin assay and similar to the sensitivity of the anti‐Ser/Pro assay.
Prevalence of Anticentromere F Protein Autoantibodies in 347 Patients with Non‐Hodgkin's Lymphoma
Authors: BENCIMON CELINE , SALLES GILLES , MOREIRA ANNICK , GUYOMARD STEPHANIE , COIFFIER BERTRAND , BIENVENU JACQUES , FABIEN NICOLE
Published: July 2005

Abstract: An association between autoimmunity and hematological malignancies has been reported including the detection of antinuclear autoantibodies (ANAs) in patients suffering from non‐Hodgkin's lymphoma (NHL), with a high prevalence of ANAs directed to components of the mitotic apparatus or the mitosis‐associated proteins. Previous studies have demonstrated that one of the targets of such ANAs could be the CENP‐F protein, especially in some carcinomas. The prevalence and specificity of anti‐CENP‐F autoantibodies (aAbs) thus were analyzed in 347 patients with different histological subgroups of NHL before any treatment of NHL, along with 150 controls. The detection of these aAbs was performed using two techniques: a radioimmunological assay (RIA) and an indirect immunofluorescence technique (IIF). Twenty‐five (7.2%) NHL patients and 2 (1.3%) control patients displayed anti‐CENP‐F aAbs using RIA. This difference between the two groups was found to be significant (P < 0.01), with a higher prevalence of aAbs in the follicular (13%) and in the marginal zone B and MALT (10.2%) lymphoma subgroups. By IIF, 10 (2.9%) patients with NHL displayed aAbs with a CENP‐F or CENP‐F‐like pattern, whereas none of the control group did. In conclusion, these data demonstrate that a significant incidence of anti‐CENP‐F aAbs is observed, before any treatment, in some histological subgroups of NHL patients. In addition to the usefulness of anti‐CENP‐F aAbs as a marker for some NHL subgroups, prospective studies may be important to evaluate the predictive value of anti‐CENP‐F aAbs for the development of carcinomas.
Comparison of Different Test Systems for Simultaneous Autoantibody Detection in Connective Tissue Diseases
Authors: EISSFELLER PETRA , STICHERLING MICHAEL , SCHOLZ DIETMAR , HENNIG KIRSTEN , LÜTTICH TANJA , MOTZ MANFRED , KROMMINGA ARNO
Published: July 2005

Abstract: The serological diagnosis of connective tissue diseases (CTDs) is based on the analysis of circulating autoantibodies to cytoplasmic and nuclear proteins (extractable nuclear antigens [ENAs]). The determination of autoantibody specificities supports the clinical diagnosis of the type of CTD and also often the prognosis of the disease. The former indirect immunofluorescence (IIF) technique still provides a useful screening method that currently is supplemented by a range of different techniques allowing the exact determination of single autoantibody specificities. These ENA profiling techniques include ELISA, immunoblotting, line‐blot assays, and flow cytometric bead‐based multiplex assays. The novel line immunoassay (LIA) from Mikrogen has been introduced in a recent study as a suitable technique for the simultaneous detection of autoantibodies in a routine clinical laboratory, providing comparable results as ELISA and ELiA (both from Pharmacia Diagnostics) (see Damoiseaux et al., this volume). In this study, LIAs from three different manufacturers were performed in 30 serum samples from patients with dermatological manifestations and 27 samples from SLE patients with renal involvement. The line assays from Mikrogen (recom Line/ANA/ENA), Innogenetics (Inno‐Lia ANA Update), and Imtec (ANA‐LIA) were compared for antigen composition, handling, and statistical analysis including sensitivity and concordance. Autoantibody frequencies detected by the Mikrogen, Innogenetics, and Imtec line assays were 14.0%, 19.3%, and 15.8% for RNP; 14.0%, 22.8%, and 14.0% for Sm; 26.3%, 31.6%, and 40.3% for SSA; 3.5%, 12.3%, and 14.0% for SSB; and 3.5%, 14.0%, and 10.5% for histones. Our studies show that the line assay format is an easy‐to‐use, sensitive, and specific method for ENA antibody detection in human sera.
Evaluation of a Novel Line‐Blot Immunoassay for the Detection of Antibodies to Extractable Nuclear Antigens
Authors: DAMOISEAUX J , BOESTEN K , GIESEN J , AUSTEN J , COHEN TERVAERT J W
Published: July 2005

Abstract: We have evaluated the performance of a novel line‐blot immunoassay (LIA; Mikrogen) and compared results with those obtained by CIE (in‐house), ELISA (Pharmacia Diagnostics), and FEIA (Pharmacia Diagnostics). Sera from systemic lupus erythematosus (SLE) patients (n= 123), systemic sclerosis patients (n= 25), and healthy controls (n= 40) were analyzed for the presence of antibodies to RNP, Sm, SSA, SSB, CENP‐B, Scl‐70, and Jo‐1. Reading of LIA results, as compared with a cutoff control, was performed by automatic analysis of the test strips. Because LIA enables recognition of separate subunits of RNP (68, A, and C), Sm (B and D), and SSA (52 and 60), at least two of the RNP antigens and either one of the Sm or SSA antigens should be detected for considering the test RNP, Sm, or SSA‐positive, respectively. LIA had the highest sensitivity in patients with autoimmune connective tissue diseases: 131 specificities (not PO, PCNA, or histones), as compared with ELISA (121), FEIA (119), and CIE (80). However, LIA revealed three positive reactions in healthy controls; other assays were completely negative. LIA is better than CIE, but similar to ELISA and FEIA, in terms of detecting systemic sclerosis‐associated antibodies (CENP‐B and Scl‐70). Furthermore, LIA had the highest sensitivity (17.9%) for the SLE‐specific anti‐Sm antibodies, as compared with ELISA (11.4%), CIE (8.1%), and FEIA (5.7%). Finally, anti‐SSA antibodies were far more prevalent by LIA in the systemic sclerosis samples because of anti‐SSA52 reactivity. The clinical relevance of the latter finding remains to be determined. In conclusion, LIA is suitable for routine evaluation of autoantibodies to extractable nuclear antigens.
A Prospective Study of 1038 Pregnancies on the Predictive Value of Anti‐Annexin V Antibodies for Fetal Loss
Authors: BIZZARO N , ANTICO A , MUSSO M , PLATZGUMMER S , CAMOGLIANO L , TOZZOLI R , VILLALTA D
Published: July 2005

Abstract: Retrospective studies have demonstrated that anti‐annexin V (anti‐AnxV) antibodies are linked to miscarriage. Their predictive value is, however, unknown. We have carried out a prospective study to evaluate the relationship between anti‐AnxV antibodies and the pregnancy outcome. A serum sample was taken from 1038 consecutive healthy women at the beginning of pregnancy. IgG and IgM anti‐AnxV antibodies were measured by an ELISA method. The cutoff value was set at 5 units for both IgG and IgM. Out of 1038 women, 116 (11.4%) had a miscarriage by the 22nd week; 10 were lost to follow‐up, 10 had an induced abortion, 6 had a preterm delivery, and 896 carried their pregnancy through to term. An adverse outcome of the pregnancy proved to be directly related to the number of previous miscarriages (P= .008)) and the age of the woman (P= .002)). IgG and IgM anti‐AnxV were present in 25% and 27% of the women who miscarried, and in 23% and 28% of those who gave birth (mean antibody concentration IgG, 4.2 vs. 4.4 U/mL; IgM, 3.7 vs. 3.5/U/mL). IgG and IgM anticardiolipin and anti‐β2GPI, together with antinuclear, antithyroperoxidase, and antithyroglobulin antibodies, were also measured in the 116 sera of the women with miscarriage and in an equal number of women who gave birth. Their positivity or level proved not to be useful in discriminating between the risk of miscarriage and term delivery. This large‐scale prospective study demonstrates that the presence of IgG and IgM anti‐AnxV antibodies, when measured in healthy women, does not give a positive predictive lead towards the possibility of a miscarriage, and it is not useful in evaluating the risk of miscarriage at the beginning of pregnancy.
Multiplexed Immunoassay for Detection of Rheumatoid Factors by FIDIS™ Technology
Authors: ABREU I. , LAROCHE P , BASTOS A , ISSERT V , CRUZ M , NERO P , FONSECA J E , BRANCO J , MACHADO CAETANO J A
Published: July 2005

Abstract: Our objective was to (i) compare FIDIS Rheuma, a new multiplexed immunoassay designed for simultaneous detection of IgM class rheumatoid factors (RF) directed against Fc determinants of IgG from humans and animals, with agglutination and ELISA (conventional methods) and (ii) evaluate the clinical sensitivity and specificity of biological markers for rheumatoid arthritis (RA). To do this, FIDIS technology was employed using the Luminex system. It consists of distinct color‐coded microsphere sets, a flow cytometer, and digital signal processing hardware and software. Agglutination and ELISA tests were performed with commercial kits. The study included 134 samples from RA patients and 105 from healthy blood donors. For human specificity, we compared FIDIS with latex agglutination and ELISA. Relative sensitivities were 98.9% and 88.5% and specificities were 90.2% and 94.6%, respectively. For animal specificity, we compared FIDIS with Waaler‐Rose and ELISA. The results were 84.9% and 71.9% for the sensitivities and 97.5% and 98.4% for the specificities, respectively. Detection of IgG anti‐CCP by ELISA and IgG antikeratin by immunofluorescence was also determined in order to compare their clinical sensitivity and specificity with IgM‐RF, according to the method used. The results were: IgG anti‐CCP 72.3%, 97.2%; IgG antikeratin 36.6%, 100%; latex agglutination 66.4%, 97.2%; Waaler‐Rose 55.9%, 96.3%; FIDIS human 73.9%, 92.1%; FIDIS animal 49.2%, 97.2%; ELISA human 93.2%, 95.5%; and ELISA animal 74.6%, 91.3%. The results showed the efficiency of FIDIS with analytical performance equivalent to the conventional methods, but having the advantage of giving quantitative results /IU/mL).
The Interaction of Pemphigus Autoimmunoglobulins with Epidermal Cells: Activation of the Fas Apoptotic Pathway and the Use of Caspase Activity for Pathogenicity Tests of Pemphigus Patients
Authors: FRUŠIĆ‐ZLOTKIN MARINA , PERGAMENTZ ROCHEL , MICHEL BENO , DAVID MICHAEL , MIMOUNI DANIEL , BRÉGÉGÈRE FRANÇOIS , MILNER YORAM
Published: July 2005

Abstract: Pemphigus is a fatal autoimmune disease in which autoimmunoglobulins PV‐IgG (binding to desmoglein 3) and PF‐IgG (binding to desmoglein 1) in pemphigus vulgaris and pemphigus foliaceus, respectively, cause intraepidermal blisters, cell‐cell separation (acantholysis), and cell death. The mechanism of acantholytic lesion formation has not yet been elucidated. Recently, we have reported that an apoptotic mechanism might be operative in PV‐IgG‐induced acantholysis: (1) in patients' lesional and some perilesional skin portions, the FasR pathway is activated as its components were enriched; (2) in cultured keratinocytes, PV‐IgG upregulates effectors of the FasR pathway (including the mitochondrial loop), as found by immunodetermination (cytochemistry, Western blot of pathway effectors) and determination of caspases 1, 3, and 8/activity/activation; (3) in organ cultures of skin incubated with PV‐IgG, activated caspase 8 was found also in perilesional cells and coaggregated with bound PV‐IgG; (4) caspase 8 activation in DISCs precedes caspase 3 activation in keratinocytes in cultures upon incubation with PV‐IgG. Because caspase activation was shown to accompany lesion formation in cell and organ cultures incubated with PV‐IgG, we used caspase activity to monitor the pathogenicity of PV‐IgG in relation to PV‐IgG binding to epithelia. A rough correlation was found between sera titers, determined by IIF and by immunoblot binding to desmoglein 3, and activation of caspase 3.
Hepatic Arterial Oxaliplatin Infusion Plus Intravenous Chemotherapy in Colorectal Cancer With Inoperable Hepatic Metastases: A Trial of the Gastrointestinal Group of the Fédération Nationale des Centres de Lutte Contre le Cancer
Authors: Ducreux Michel , Ychou Marc , Laplanche Agnès , Gamelin Erick , Lasser Philippe , Husseini Fares , Quenet François , Viret Frédéric , Jacob Jacques-Henri , Boige Valérie , Elias Dominique , Delperro Jean-Robert , Luboinski Monique
Published: July 2005

Purpose

Isolated hepatic metastases of colorectal cancer constitute a frequent and serious therapeutic problem that has led to the evaluation of hepatic arterial infusion (HAI) of different drugs. Oxaliplatin combined with fluorouracil (FU) and leucovorin is effective in the treatment of colorectal cancer. In this context, a phase II study was conducted to evaluate concomitant administration of oxaliplatin by HAI and intravenous (IV) FU plus leucovorin according to the LV5FU2 protocol (leucovorin 200 mg/m2, FU 400 mg/m2 IV bolus, FU 600 mg/m2 22-hour continuous infusion on days 1 and 2 every 2 weeks).

Patients and Methods

Patients had metastatic colorectal cancer that was restricted to the liver and inoperable. The patients were not to have previously received oxaliplatin. After surgical insertion of a catheter in the hepatic artery, patients were treated with oxaliplatin 100 mg/m2 HAI combined with FU + leucovorin IV according to the LV5FU2 protocol. Treatment was continued until disease progression or toxicity. Response was evaluated every 2 months.

Results

Twenty-eight patients were included, and 26 patients were treated. Two hundred courses of therapy were administered, and the median number of courses received was eight courses (range, zero to 20 courses). The most frequent toxicity consisted of neutropenia. The main toxicity related to HAI was pain. The intent-to-treat objective response rate was 64% (95% CI, 44% to 81%; 18 of 28 patients). With a median follow-up of 23 months, the median overall and disease-free survival times were 27 and 27 months, respectively.

Conclusion

The combination of oxaliplatin HAI and FU + leucovorin according to the LV5FU2 protocol is feasible and effective in patients presenting with isolated hepatic metastases of colorectal cancer.
Detection of Thymidylate Synthase Expression in Lymph Node Metastases of Colorectal Cancer Can Improve the Prognostic Information
Authors: Öhrling Katarina , Edler David , Hallström Marja , Ragnhammar Peter , Blomgren Henric
Published: July 2005

Purpose

The level of thymidylate synthase (TS) in primary colorectal cancer (CRC) has been reported as a prognostic marker. The purpose of this study was to determine whether TS expression in lymph node metastases of Dukes' C CRC is a prognostic marker.

Patients and Methods

TS expression in the primary tumor and lymph node metastases from 348 patients with Dukes' C CRC was retrospectively assessed using immunohistochemistry and the monoclonal antibody TS 106. The patients had all been enrolled onto our previous study of 862 CRC patients who were included in Nordic trials that randomly assigned the patients to either surgery alone or surgery plus adjuvant chemotherapy.

Results

TS expression in lymph node metastases was a distinct prognostic marker in the entire study group for overall survival (OS; P = .02) and disease-free survival (DFS; P = .04). A low TS expression in the lymph node metastases correlated with a better clinical outcome. In the subgroup of patients treated with surgery alone, the expression of TS in lymph node metastases also had a prognostic value for OS (P = .04) and DFS (P = .03), but this was not the case for the other subgroup who received adjuvant fluorouracil-based chemotherapy (OS, P = .5; DFS, P = .2). The expression of TS in the primary tumor only had a significant prognostic value among patients who were treated with surgery alone (OS, P = .03; DFS, P = .03) and not among the entire patient population.

Conclusion

These data show that TS expression in lymph node metastases is a prognostic marker for patients with Dukes' C CRC.
Fludarabine, Melphalan, and Alemtuzumab Conditioning in Adults With Standard-Risk Advanced Acute Myeloid Leukemia and Myelodysplastic Syndrome
Authors: van Besien Koen , Artz A. , Smith S. , Cao D. , Rich S. , Godley L. , Jones D. , Del Cerro P. , Bennett D. , Casey B. , Odenike O. , Thirman M. , Daugherty C. , Wickrema A. , Zimmerman T. , Larson R.A. , Stock W.
Published: July 2005

Purpose

This prospective phase II study evaluated toxicity, relapse rate, progression-free survival, and overall survival after allogeneic transplantation and conditioning with fludarabine, melphalan, and alemtuzumab in patients with acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS).

Patients and Methods

Fifty-two consecutive adults with AML and MDS were enrolled onto the study. Median age was 52 years (range, 17 to 71 years) and the majority of patients had high-risk disease, comorbidities, and/or modest reduction in performance status. Fifty-six percent of patients had unrelated or mismatched related donors.

Results

After a median follow-up of 18 months (range, 2 to 34 months), 1-year survival was 48% (95% CI, 34% to 61%), progression-free survival was 38% (95% CI, 25% to 52%), relapse rate was 27% (95% CI, 15% to 40%), and treatment-related mortality was 33% (95% CI, 20% to 46%). The cumulative probability of extensive chronic graft-versus-host disease (GVHD) was only 18% (95% CI, 8% to 40%); extensive chronic GVHD was only observed in recipients of unrelated donor transplants. Performance score and disease status were the major predictors of outcome. High-risk disease (ie, active AML or MDS with > 5% blasts) or even modest decreases in performance status were associated with poor outcomes. Patients with standard-risk leukemia (first or second complete remission) or MDS (< 5% blasts) had excellent outcomes despite unfavorable disease characteristics.

Conclusion

Fludarabine and melphalan combined with in vivo alemtuzumab is a promising transplantation regimen for patients with AML or MDS and low tumor burden. For patients with active disease, this regimen provides at best modest palliation. Despite a low incidence of GVHD, transplantation is still associated with considerable nonrelapse mortality in patients with decreased performance status.
Cortical development: the art of generating cell diversity
Authors: Götz Magdalena , Sommer Lukas
Published: July 2005

The fascinating question of how the enormous diversity of neuronal and glial cells in the cerebral cortex is generated during development was recently discussed at a meeting on cortical development and stem cells in Greece. What emerged from this meeting is an equally fascinating answer,namely that precursor diversity at rather early stages of development anticipates later cell type diversity.
Roles of heterogeneous nuclear ribonucleoproteins A and B in cell proliferation
Authors: He Yaowu , Brown Melissa A. , Rothnagel Joseph A. , Saunders Nicholas A. , Smith Ross
Published: July 2005

Overexpression of heterogeneous nuclear ribonucleoproteins (hnRNPs) A2 and B1 has been observed in a variety of tumour types, however, it is unknown whether this dysregulation is a consequence of, or a driving force for, unregulated cell proliferation. We have shown that the levels of hnRNPs A1, A2 and B1, but not A3, are modulated during the cell cycle of Colo16 squamous carcinoma cells and HaCaT immortalized keratinocytes, suggesting that A1, A2 and B1 are needed at particular cell cycle stages. However, the levels of hnRNP A1, A2 and B1 mRNAs were constant, indicating that regulation of protein levels was controlled at the level of translation. RNAi suppression of hnRNP A1 or A3 alone did not affect the proliferation of Colo16 cells but the proliferation rate was significantly reduced when both were suppressed simultaneously, or when either was suppressed together with hnRNP A2. Reducing hnRNP A2 expression in Colo16 and HaCaT cells by RNAi led to a non-apoptotic-related decrease in cell proliferation, reinforcing the view that this protein is required for cell proliferation. Suppression of hnRNP A2 in Colo16 cells was associated with increased p21 levels but p53 levels remained unchanged. In addition, expression of BRCA1 was downregulated, at both mRNA and protein levels. The observed effects of hnRNP A2 and its isoforms on cell proliferation and their correlation with BRCA1 and p21 expression suggest that these hnRNP proteins play a role in cell proliferation.
Correlation of Raman Phonon and Europium(III) Luminescence Spectra as a Probe of Structure in Trisodium Tris(2,6-Pyridinedicarboxylato)Lanthanide(III) Compounds
Authors: Murray G. M. , Sarrio R. V. , Peterson J. R.
Published: July 2005

Raman phonon and probe ion luminescence spectroscopy has been demonstrated as a reliable means of differentiating the various crystal structures of many trisodium tris(2,6-pyridinedicarboxylato)lanthanide(III) compounds. The luminescence spectra have been measured at high resolution and at low temperature (77 K) to show the sensitivity of this spectral method to slight changes in the metal ion coordination polyhedra which are due to differing crystal structures. The use of optical means for determining crystal structure is being explored for potential use with highly radioactive transuranium elements.
Nondestructive Quantitative Analysis of Ethylene-Propylene Blend Polymer by the NIR/ATR/FT-IR Method
Authors: Nishio Etsuo , Morimoto Mitsuhiko , Nishikida Koichi
Published: July 2005

The attenuated total reflectance Fourier transform infrared (ATR/FT-IR) method in the near-infrared region was found to provide a novel opportunity for nondestructive analysis of ethylene-propylene (EP) blend polymer. The absorption due to the overtone of the C-H stretching vibration at ∼5900 cm−1 was utilized to determine the ratio of two monomer units, the ethylene and propylene units, of the blend polymer, since the overlapping of CH3- and -CH2- is not so prohibitive as in the case of the fundamental C-H stretching vibration at ∼2900 cm−1. The well-known disadvantage of the weak intensity of the overtone absorption, however, was overcome by the choice of the high-sensitivity FT-IR technique.
Differential Optical Absorption Spectroscopy (DOAS) Measurements of Ozone in the 280–290 nm Wavelength Region
Authors: Axelsson Håkan , Edner Hans , Galle Bo , Ragnarson PÄR , Rudin Mats
Published: July 2005

The differential absorption structure of the ozone spectrum between 250 and 330 nm has been investigated in order to determine the optimal wavelength region to be utilized for active differential optical absorption spectroscopy (DO AS) measurements. Considering aspects of atmospheric attenuation and interference from other species as well as the magnitude of the differential absorption cross section, an interval around 283 nm was found to be a good candidate for this application. This result was also verified during 12 months of continuous ozone monitoring in an urban environment.
In situ Near-Infrared Internal Reflection Spectroscopy for Surfactant Adsorption Reactions Using Reactive Internal Reflection Elements
Authors: Kellar J. J. , Cross W. M. , Miller J. D.
Published: July 2005

The near-infrared (NIR) (12,000-4000 cm−1) region of the electromagnetic spectrum, between the mid-infrared and visible, has often been viewed by spectroscopists to be of limited utility. This is unfortunate, and recently the use of the NIR has increased greatly, primarily for the quantitative analysis of food and agricultural products. However, many other areas of application of NIR spectroscopy remain unexamined. In this paper a novel use of NIR in the area of surface chemistry is demonstrated. Specifically, it is shown that NIR/Internal Reflection Spectroscopy (IRS) can be used to quantify surfactant adsorption reactions in situ.
Electrostatic Precipitation Atomic Absorption Spectrometry
Authors: Sneddon Joseph
Published: July 2005

The theory and principles, design, construction, and preliminary evaluation of a system based on the electrostatic precipitation of metals in aerosols on a tungsten collecting electrode, followed by injection of this rod into an electrothermal atomizer for atomic absorption spectrometric determination of the metal, is described. With the use of a manganese aerosol generated by an electrothermal vaporizer, the highest atomic absorption signals—and therefore the optimum charging and collecting efficiency for the geometry of the system as described—were achieved with a negative corona of 15 kV and low aerosol velocity. The system determined copper in the laboratory atmosphere on a near-real-time basis.
Signal-to-Noise Comparison of Flame/Furnace Infrared Emission (FIRE) Spectrometry with Room-Temperature, Nondispersive Infrared Absorption Spectrophotometry
Authors: Busch Marianna A. , Busch Kenneth W.
Published: July 2005

A theoretical model has been developed for the comparison of the performance of a detector-noise-limited, flame infrared emission (FIRE) spectrometer with that of a room-temperature, nondispersive, infrared absorption (NDIR) spectrophotometer. The ratio of the signal-to-noise ratio (SNR) in emission to that in absorption is found to depend on the product of five terms: (1) the ratio of the noise in absorption to that in emission; (2) the ratio of the solid angles in emission and absorption; (3) the ratio of the pathlengths in emission and absorption; (4) the ratio of the number densities in emission and absorption; and (5) the ratio of the Boltzmann factor for the flame to the Bose-Einstein factor for the blackbody source. Implications for gas chromatographic detection are considered. Under conditions in which chemical conversion of the sample into an infrared-active species is not required and both measurements employ an uncooled PbSe detector, a sample cell volume of 30 μL, and a filter bandwidth of 0.30 μm at a wavelength 4.35 μm (the antisymmetric stretching vibration of CO2), the major factor which determines the ratio of the two SNRs will be the ratio of the solid angle × pathlength product, which has a constant value of 100, regardless of the sample cell path-length chosen. If a hydrogen/air flame is used in emission (2272 K) and a Nernst glower is used in absorption (1800 K), the FIRE spectrometer is predicted to produce an SNR that is at least 19 times better than that produced by the corresponding NDIR absorption photometer, regardless of the pathlength of the absorption cell.
Coupled External Reflectance FT-IR/Miniaturized Surface Film Apparatus for Biophysical Studies
Authors: Flach Carol R. , Brauner Joseph W. , Mendelsohn Richard
Published: July 2005

An FT-IR spectrophotometer has been interfaced to a miniaturized surface film apparatus for external reflection studies of insoluble monolayers in situ at the air/water interface. Signal-to-noise ratios of 200:1 were routinely achieved for the CH2 stretching vibrations of phospholipids. We have monitored, using the acyl chain symmetric CH2 stretching frequency near 2850 cm−1 as a structural probe, lipid conformational order changes that occur during the surface pressure-induced two-dimensional phase transition in monolayers of 1,2-dipalmitoylphosphatidylserine. In addition, the small volume of the miniaturized film apparatus (30 mL) permitted replacement of H2O with D2O in the subphase. This capability, in turn, permits the acquisition of spectral data in the amide I region of proteins. We report the first external reflection FT-IR spectrum of an insoluble protein monolayer. The protein studied is pulmonary surfactant SP-C.
Single-Shot Elemental Analysis of Liquids Based on Laser Vaporization at Fluences below Breakdown
Authors: Cheung Nai-Ho , Yeung Edward S.
Published: July 2005

A novel yet simple spectrochemical technique for analyzing liquid samples has been demonstrated, which is based on pulsed laser vaporization at sub-breakdown fluences, together with acoustic normalization for improved precision. By the use of ArF laser vaporization of NaCl solution as a test case, a dynamic range of three orders of magnitude was realized, and as little as 0.23 ppm of Na can be detected. Because of the high precision and small focal volume, the absolute detectability can be as low as 0.4 pg (20 fmol). ArF laser vaporization of KCl and BaCl2 was also investigated, and detection limits of 1.5 ppm and 130 ppm were established for K and Ba, respectively.
Polycyclic Aromatic Hydrocarbon Solute Probes. Part X: Evaluation of Select Hydrogenated Pyrene, Benzo[ghi]perylene, and Naphthacene Derivatives as Possible Solvent Polarity Probes
Authors: Tucker Sheryl A. , Acree William E. , Fetzer John C. , Mitchell Reginald H.
Published: July 2005

Fluorescence emission spectra are reported for 3,4,5-trihydrobenzo[cd]pyrene, 3,4-dihydrobenzo[ghi]perylene, 5,6,7,8,9,10-hexahydrobenzo[ghi]perylene, trans-10b,10c-dihydro-10b,10c-dimethylpyrene, trans-12b,12c-dihydro-12b,12c-dimethylbenzo[a]pyrene, and trans-14b,14c-dihydro-14b,14c-dimethylnaphtho[2,1,8-qra]naphthacene dissolved in organic nonelectrolyte solvents of varying polarity. Dihydrobenzo|ghi]perylene was found to exhibit probe character, as evidenced by a systematic variation in emission intensity ratio with solvent polarity. It has a dynamic range of 0.98 and a high fluorescence quantum yield and is thought to be noncarcinogenic. Also reported are mathematical expressions which correlate measured intensity ratios and solvent polarity probe behavior of dihydrobenzo[ghi]perylene, pyrene, benzo[ghi]perylene, coronene, and ovalene in 48 solvents of varying polarity.
Molecular Motion Analysis of E7 in PDLCs as a Function of Droplet Size Using Solid-State 13C NMR Relaxation Spectroscopy
Authors: Buchert Karen L. , Koenig Jack L. , Wang Shi-Qing , West John L.
Published: July 2005

13C NMR relaxation spectroscopy as applied to polymer-dispersed liquid crystals (PDLCs) provides a method for measuring the molecular motions of the liquid crystal molecules within droplets dispersed throughout the material's polymer matrix. Because liquid crystal molecular motion may play a major role in the switching phenomenon of PDLC materials from an opaque film to a clear film, both T1 and T1ρ relaxation experiments are used to measure molecular mobility of the liquid crystal as a function of droplet size for PDLC materials made of E7 and epoxy. The segmental molecular motions measured by T1ρ relaxation show a significant dependence on liquid crystal droplet size. Three models are provided which explain the observed restriction in segmental mobility of the liquid crystal molecules as the droplet size decreases and the polymer/liquid crystal interaction increases.
Feasibility and Performances of a New, Multiplexed, Fast and Low-Cost Fiber-Optic NIR Spectrometer for the On-Line Measurement of Sugar in Fruits
Authors: Bellon Véronique , Vigneau Jean Louis , Leclercq Michel
Published: July 2005

This paper describes an attempt to develop a new NIR spectrometer to sort fruits according to the sugar content in the conditioning stations. This spectrometer, ranging from 800 to 1050 nm, is based on diode array technology. It is coupled with fiber optics, which allow multiplexing; 20 fibers have been detected by the camera, showing the potential multiplexing of 20 different points. The acquisition time is 40 ms per image (i.e., 2 ms per spectrum). A good signal-to-noise ratio has been recorded in the 820–1010 nm range. This spectrometer has been tested with a set of 79 peaches. Partial least-squares processing is applied to different wavelength ranges. The best coefficient of correlation, achieved with a reduced wavelength range (from 847 to 977 nm), is 0.81, and the standard error of prediction is 1.04°Brix. With this calibration, the fruits can be sorted into three maturity classes with a reliability of 76%. This performance, as well as the other characteristics of the instrument, is in accordance with the requirements of the conditioning station managers.
Polarization-Modulated FT-IR Spectroscopy of a Spread Monolayer at the Air/Water Interface
Authors: Blaudez D. , Buffeteau T. , Cornut J. C. , Desbat B. , Escafre N. , Pezolet M. , Turlet J. M.
Published: July 2005

This study devoted to the FT-IR spectroscopy of monolayers spread at the air/water interface is, to our knowledge, the first report presenting complete mid-infrared monolayer spectra perfectly extracted from the strong water vapor bands. This has been possible with the use of the polarization-modulated IRRAS method, which is not sensitive to the isotropic absorptions of the sample environment. On the basis of theoretical modeling and experiments, the best angle of incidence has been found near 76° for detection of intraplane as well as out-of-plane oriented monolayer absorptions. With the use of such experimental conditions, on the normalized difference (covered vs. uncovered water) PM-IRRAS spectra, monolayer vibrational bands come out upward or downward, depending on the orientation of their transition moment with respect to the interface. Application to the study of deuterated arachidic acid and arachidate monolayers allows observation of the vibrational modes of the polar head groups interacting with the liquid water molecules and provides some evidence of their symmetrical anchoring. The vibrational modes of the liquid water subphase contribute to these difference spectra as broad dips that certainly contain information on a possible restructuring of the water molecules at the interface.
Novel Approach to Quantitative Depth Profiling of Surfaces Using ATR/FT-IR Measurements
Authors: Huang Jiangbing , Urban Marek W.
Published: July 2005

Reflection theory for step-wise stratified media is applied to establish the relationship between the reflectivity data obtained from ATR/FT-IR surface depth profiling experiments and the concentration at a given surface depth. In spite of the mathematical complexity of the process, an unknown surface depth profiling can be calculated by using a linear interpolation, or by applying a function with variable parameters. Due to limited assumptions and fairly reasonable computation time, even when the sample is finely divided to achieve high spatial resolution, the linear interpolation approach seems to be particularly advantageous. The proposed methodology is tested for the distribution of surfactant molecules and calculations of the surface depth profiles in latex thin films.
Quantitative Analysis of Sphene (CaTiOSiO4) and Wollastonite (CaSiO3) Crystallizations in Annealed Ceramic Frits by FT-IR Absorption Spectroscopy
Authors: Chen S. K. , Liu H. S. , Wu C. S.
Published: July 2005

Results of this study have shown the feasibility of FT-IR absorption spectra (between 500 and 700 cm−1) for the quantitative determination of the nucleation and crystal growths of sphene (CaTiOSiO4) and wollastonite (β-CaSiO3) in two separate typical ceramic frits that have been annealed between 800 and 1000°C. Synthetic sphene ceramics and natural wollastonite, both of high purity and excellent crystallinity, serve as standard materials for calibration by the classical least-squares method (Basic Quant), employing the peaks of a sharp band at 561–566 cm−1 assigned to the SiO4 vibration and that of a shoulder (676 cm−1) of a broad band assigned to TiO6 vibrations. The correlation coefficients for these calibrations (absorbance vs. concentration of crystalline phase) are given as 0.9964, 0.9936, and 0.9937, respectively. Between annealing temperatures of 850 and 1000°C, both sphene and wollastonite phases appear to grow steadily in frit-S and frit-W, when the highest value of crystal growth is noted for specimens annealed at 1000°C, being approximately 80 wt % and 66 wt % of the formulated content, respectively. Scanning electron micrographs provide pictorial evidence to show that quantitative characterization of crystalline phase growth in ceramic frits by FT-IR absorption spectra is an appropriate technique.
Photopyroelectric (PPE) Spectroscopy of Radiation Conversion Efficiency in Fluorescent Dye Ink Layers
Authors: Chirtoc Mihai , Candea Rodica M. , Pelzl Josef
Published: July 2005

The analytic and spectroscopic potential of a new, reflection mode photopyroelectric technique (RPPE) applied to fluorescent layered materials is demonstrated and validated by alternative optical measurements. The theoretical model defines three conversion efficiencies characterizing the sample at the macro- and microscopic levels. The experimental spectral data allow for the identification of the dye inks as containing Rhodamine B and Coumarin 6. Adverse effects for the fluorescence efficiency in the case of solid layers are also investigated and discussed.
Canonical Correlation Analysis of Mid- and Near-Infrared Oil Spectra
Authors: Devaux M. F. , Robert P. , Qannari A. , Safar M. , Vigneau E.
Published: July 2005

A mathematical procedure based on Canonical Correlation Analysis (CCA) was used in order to assign the wavelengths of the near-infrared spectra through knowledge of the mid-infrared spectra. The relevance of the treatment was tested on commercial oils that mainly differ in their level of unsaturation. Initially, two separated Principal Component Analyses (PCAs) were performed on the near- and mid-infrared data to overcome the high intercorrelations across the wavelengths. CCA was then applied to the resulting principal components. Near- and mid-infrared canonical variates were assessed so that they achieved maximum correlation. The procedure makes it possible to draw CCA spectral patterns that exhibit significant positive and negative peaks. The first near-infrared canonical variate was highly correlated with the first mid-infrared canonical variate ( r2 = 0.97). The corresponding near- and mid-infrared CCA spectral patterns were therefore given the same interpretation. The mid-infrared pattern opposed negative peaks characteristic of CH2 groups to the positive peaks of CH3 and =CH groups. Consequently, in the near-infrared pattern, the positive peaks at 1708, 2140, 2170, and 2480 nm were assigned to CH3 or =CH groups, and the negative peaks at 2304, 2344, and 2445 nm were assigned to CH2 groups. A more precise interpretation was obtained by comparing the wavelengths observed to theoretical values and to previous assignments.
Compositional Effects on the Crystallization Kinetics of Nickel Titanium Thin Films
Authors: Ni Hai , Lee Hoo-Jeong , Ramirez Ainissa G.
Published: July 2005

The crystallization and phase transformations of amorphous NiTi thin films were studied using in situ transmission electron microscopy (TEM). These films were sputter-deposited onto micromachined silicon-nitride membranes and subjected to heating and cooling conditions. The microstructural evolution was monitored and recorded. Kinetic parameters such as the nucleation rate, growth rate, and area-fraction transformed were independently determined by noting the number of grains per frame and their change in size. Using the Johnson–Mehl–Avrami–Kolmogorov analysis, fitted kinetic parameters were determined and found to be consistent with TEM observations. To explore the compositional sensitivity of crystallization, samples near-equiatomic and slightly Ti-rich were studied with these methods. TEM micrographs show that equiatomic films exhibit polymorphic crystallization while samples that are slightly off-stoichiometry showed more complicated behavior.
In situ Transmission Electron Microscopy Ion Irradiation Studies at Orsay
Authors: Ruault M-O. , Fortuna F. , Bernas H. , Chaumont J. , Kaïtasov O. , Borodin V.A.
Published: July 2005

Crucial features of materials evolution due to ion beam irradiation are often revealed only through studies of process dynamics. We review some significant examples of such experiments performed over the last 25 years with the Orsay in situ facility: a transmission electron microscope setup (with temperature stages operating between 4 and 1000 K) on a medium energy (3–570 keV) ion beam line. New results on nanocavity evolution and metal silicide nanoprecipitates in Si are presented briefly.We show that CoSi2 nanoprecipitate growth is mainly due to the constant Co atom contribution from the ion beam, and CoSi2 platelet growth is the result of a three-dimensional to two-dimensional growth mode transition.
In situ Transmission Electron Microscopy Studies on Structural Dynamics of Transition Metal Nanoclusters
Authors: Vystavel T. , Koch S.A. , Palasantzas G. , De Hosson J.Th.M.
Published: July 2005

The structural stability of transition metal nanoclusters has been scrutinized with in situ transmission electron microscopy as a function of temperature. In particular iron, cobalt, niobium, and molybdenum clusters with diameters around 5 nm have been investigated. During exposure to air, a thin oxide shell with a thickness of 2 nm is formed around the iron and cobalt clusters, which is thermally unstable under moderate high vacuum annealing above 200 °C. Interestingly, niobium clusters oxidize only internally at higher temperatures without the formation of an oxide shell. They are unaffected under electron beam irradiation, whereas iron and cobalt undergo severe structural changes. Further, no cluster coalescence of niobium takes place, even during annealing up to 800 °C, whereas iron and cobalt clusters coalesce after decomposition of the oxide, as long as the clusters are in close contact. In contrast to niobium, molybdenum clusters do not oxidize upon annealing; they are stable under electron beam irradiation and coalesce at temperatures higher than 800 °C. In all cases, the coalescence process indicates a strong influence of the local environment of the cluster.
High-temperature Dislocation-precipitate Interactions in Al Alloys: An in situ Transmission Electron Microscopy Deformation Study
Authors: Clark B.G. , Robertson I.M. , Dougherty L.M. , Ahn D.C. , Sofronis P.
Published: July 2005

The fundamental processes controlling the high-temperature interaction of dislocations with precipitates in Al-alloys were investigated in real time by deforming specimens in situ in the transmission electron microscope at elevated temperature. The observations support a bypass mechanism involving the interaction of lattice dislocations with the precipitate–matrix interface dislocations, where the rate-limiting step in the interaction is the release of the dislocation from the particle. These observations are discussed in relation to high-temperature deformation processes and models.
Application of in situ Transmission Electron Microscopyfor Tribological Investigations of Magnetron Sputter Assisted Pulsed Laser Deposition of Yttria-stabilized Zirconia-gold Composite Coatings
Authors: Hu J.J. , Voevodin A.A. , Zabinski J.S.
Published: July 2005

Yttria-stabilized zirconia (YSZ)-Au composite coatings have great potential as solid film lubricants for aerospace applications over a wide range of environmental conditions. They were grown on steel disks or silicon wafers by pulsed laser ablation of YSZ and simultaneous magnetron sputtering of a Au target. Such a combination of ceramics with soft metals improved the toughness of the composite coating and increased its ability to lubricate at high temperature. Information on the time-dependent response of these microstructures to changes in temperature is essential to tribological investigations of high temperature performance. In situ transmission electron microscopy was used to directly measure the dynamic change of YSZ-Au coating structure at elevated temperatures. High-resolution electron microscopy and electron diffraction showed that amorphous YSZ-5 at.% Au coatings proceeded to crystallize under the irradiation of electron beams. Time varying x-ray energy dispersive spectra measured a loss of oxygen in the sample during about 10 min of irradiation with subsequent slight oxygen recovery. This behavior was related to the activation of oxygen diffusion under electron irradiation. X-ray diffraction patterns from vacuum annealed samples verified crystallization of the coatings at 500 °C. Real-time growth of Au nanograins in the sample was observed as the temperature was increased to 500 °C in a TEM specimen holder that could be heated. The grain growth process was recorded using a charge-coupled device camera installed on the transmission electron microscope. The crystallization and growth of zirconia and Au nanograins resulted in low friction during tribological tests. The nucleation of Au islands on heated ball-on-flat specimens was responsible for lowering friction.