ABSTRACT
The non-destructive, in-situ identification of synthetic organic pigments employed in contemporary painting still represents a challenge. In the present study, a non-invasive analytical method based on spectrofluorimetry and visible reflectance spectroscopy was developed to this aim and applied to a considerable number of synthetic organic pigments belonging to the main chemical classes and sold by different manufacturers. In order to discriminate among them, the collected data were processed by a multivariate statistical approach, using principal component analysis (PCA). Moreover, the Kubelka-Munk correction for self-absorption of fluorescence emission was successfully applied to identify pigments in binary mixtures. This approach was finally exploited to recognise the organic pigments used by the artist in a contemporary painting.
ABSTRACT
OBJECTIVES: Most research addressing needs and concerns of young patients with breast cancer (≤40 years) is retrospective. The HOHO European protocol is a prospective multicenter cohort study of young women with newly diagnosed breast cancer, about fertility, psychosocial and quality of life concerns. Here we report the baseline data and focus on predictors of fertility concerns. MATERIALS AND METHODS: Patient surveys and medical record review were used. The baseline survey included sociodemographic, medical and treatment data as well as questions on fertility concerns and preservation strategies. Subscales from the CAncer Rehabilitation Evaluation System-Short Form (CARES-SF) were administered to measure specific quality of life aspects. Uni- and multivariable modeling were used to investigate predictors of greater fertility concern. RESULTS: Among 297 eligible respondents, 67% discussed fertility issues before starting therapy, 64% were concerned about becoming infertile after treatment, and 15% decided not to follow prescribed therapies. Fifty-four percent of women wished future children before diagnosis; of these, 71% still desired biologic children afterwards. In multivariable analysis, not having children was the only patient characteristic significantly associated with fertility concerns at diagnosis. Twenty-seven percent used fertility preservation strategies. Women who received chemotherapy reported greater physical (pâ¯=â¯0.021) and sexual difficulties (pâ¯=â¯0.039) than women who did not. Women who were married or had a partner reported less psychosocial problems than single women (pâ¯=â¯0.039). CONCLUSIONS: Young women with newly diagnosed breast cancer have several concerns, including, but not limited to, fertility. The HOHO European study provides valuable information to develop targeted interventions.
Subject(s)
Breast Neoplasms/diagnosis , Decision Making , Fertility Preservation/psychology , Fertility Preservation/statistics & numerical data , Quality of Life , Adult , Age Factors , Breast Neoplasms/psychology , Breast Neoplasms/therapy , Cohort Studies , Europe , Female , Humans , Italy , Longitudinal Studies , Prospective Studies , Risk Assessment , Surveys and Questionnaires , Switzerland , United StatesABSTRACT
PURPOSE: To investigate the efficacy of metformin (M) plus chemotherapy versus chemotherapy alone in metastatic breast cancer (MBC). METHODS: Non-diabetic women with HER2-negative MBC were randomized to receive non-pegylated liposomal doxorubicin (NPLD) 60 mg/m2 + cyclophosphamide (C) 600 mg/m2 × 8 cycles Q21 days plus M 2000 mg/day (arm A) versus NPLD/C (arm B). The primary endpoint was progression-free survival (PFS). RESULTS: One-hundred-twenty-two patients were evaluable for PFS. At a median follow-up of 39.6 months (interquartile range [IQR] 24.6-50.7 months), 112 PFS events and 71 deaths have been registered. Median PFS was 9.4 months (95% CI 7.8-10.4) in arm A and 9.9 (95% CI 7.4-11.5) in arm B (P = 0.651). In patients with HOMA index < 2.5, median PFS was 10.4 months (95% CI 9.6-11.7) versus 8.5 (95% CI 5.8-9.7) in those with HOMA index ≥ 2.5 (P = 0.034). Grade 3/4 neutropenia was the most common toxicity, occurring in 54.4% of arm A patients and 72.3% of the arm B group (P = 0.019). M induced diarrhea (G2) was observed in 8.8% of patients in Arm A. The effect of M was similar in patients with HOMA index < 2.5 and ≥ 2.5, for PFS and OS. CONCLUSIONS: The MYME trial failed to provide evidence in support of an anticancer activity of M in combination with first line CT in MBC. A significantly shorter PFS was observed in insulin-resistant patients (HOMA ≥ 2.5). Noteworthy, M had a significant effect on CT induced severe neutropenia. Further development of M in combination with CT in the setting of MBC is not warranted.
Subject(s)
Breast Neoplasms/drug therapy , Cyclophosphamide/administration & dosage , Doxorubicin/administration & dosage , Metformin/administration & dosage , Receptor, ErbB-2/deficiency , Aged , Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Breast Neoplasms/metabolism , Breast Neoplasms/mortality , Cyclophosphamide/adverse effects , Doxorubicin/adverse effects , Drug Administration Schedule , Drug Therapy , Female , Humans , Metformin/adverse effects , Middle Aged , Progression-Free Survival , Survival Analysis , Treatment OutcomeABSTRACT
We provide data on fetal growth pattern on the molecular subtypes of Beckwith-Wiedemann syndrome (BWS): IC1 gain of methylation (IC1-GoM), IC2 loss of methylation (IC2-LoM), 11p15.5 paternal uniparental disomy (UPD), and CDKN1C mutation. In this observational study, gestational ages and neonatal growth parameters of 247 BWS patients were compared by calculating gestational age-corrected standard deviation scores (SDS) and proportionality indexes to search for differences among IC1-GoM (n = 21), UPD (n = 87), IC2-LoM (n = 147), and CDKN1C mutation (n = 11) patients. In IC1-GoM subgroup, weight and length are higher than in other subgroups. Body proportionality indexes display the following pattern: highest in IC1-GoM patients, lowest in IC2-LoM/CDKN1C patients, intermediate in UPD ones. Prematurity was significantly more prevalent in the CDKN1C (64%) and IC2-LoM subgroups (37%). Fetal growth patterns are different in the four molecular subtypes of BWS and remarkably consistent with altered gene expression primed by the respective molecular mechanisms. IC1-GoM cases show extreme macrosomia and severe disproportion between weight and length excess. In IC2-LoM/CDKN1C patients, macrosomia is less common and associated with more proportionate weight/length ratios with excess of preterm birth. UPD patients show growth patterns closer to those of IC2-LoM, but manifest a body mass disproportion rather similar to that seen in IC1-GoM cases.
Subject(s)
Beckwith-Wiedemann Syndrome/genetics , Cyclin-Dependent Kinase Inhibitor p57/genetics , DNA Methylation , Fetal Development/genetics , Genomic Imprinting , Uniparental Disomy , Anthropometry , Beckwith-Wiedemann Syndrome/classification , Beckwith-Wiedemann Syndrome/diagnosis , Beckwith-Wiedemann Syndrome/pathology , Chromosomes, Human, Pair 11/chemistry , Fetus , Gene Expression , Genotype , Gestational Age , Humans , Infant, Newborn , Mutation , Phenotype , Premature BirthABSTRACT
We use a holographic technique to measure simultaneously and separately the temporal evolution of the refractive-index and the absorption coefficient modulations induced by light in a photosensitive material. The technique is phase sensitive, allowing separation of the signals from the phase and from the amplitude grating. The refractive-index and the absorption coefficient modulations as well as the kinetic constant of the photoreaction in the positive photoresist SC 1827 were measured at three different wavelengths. The results were compared with independent measurements, performed under homogeneous exposition. The good accord demonstrates the applicability of the technique to study photosensitive materials.
ABSTRACT
As data on X-chromosomal short tandem repeats (X-STRs) for the Brazilian population are scarse, the aim of this study was to determine the allele frequencies of five X-STRs (DXS6854, DXS7424, DXS101, DXS6808 and DXS7132) in the São Paulo State, Brazil. No deviations from the Hardy-Weinberg equilibrium were observed, with the exception of DXS101. The forensic efficiency parameters demonstrated that DXS101 was the most informative marker. Population comparisons revealed that the X-STR profile sampled in the state of São Paulo was more similar to European and African populations than Asiatic populations reported in this work.
Subject(s)
Chromosomes, Human, X/genetics , Genetic Variation , Genetics, Population , Brazil , Female , Gene Frequency/genetics , Humans , Male , Microsatellite Repeats/geneticsABSTRACT
Allele frequency distributions and population data for 12 Y-chromosomal short tandem repeats (STRs) included in the PowerPlex Y Systems (Promega) were obtained for a sample of 200 healthy unrelated males living in São Paulo State (Southeast of Brazil). A total of 192 haplotypes were identified, of which 184 were unique and 8 were found in 2 individuals. The average gene diversity of the 12 Y-STR was 0.6746 and the haplotype diversity was 0.9996. Pairwise analysis confirmed that our population is more similar with the Italy, North Portugal and Spain, being more distant of the Japan.
Subject(s)
Chromosomes, Human, Y , Gene Frequency , Genetics, Population , Tandem Repeat Sequences , Brazil , DNA Fingerprinting , Haplotypes , Humans , Male , Polymerase Chain ReactionABSTRACT
Measurement of the phase difference between the 0th and the 1st transmitted diffraction orders of a symmetrical surface-relief grating recorded on a photoresist film is carried out by replacement of the grating in the same setup with which it was recorded. The measurement does not depend on lateral shifts of thereplaced grating relative to the interference pattern, on environmental phase perturbations or on the wave-front quality of the interfering beams. The experimental data agree rather well with theoretical results calculated for sinusoidal profiled gratings.
ABSTRACT
Cancer is often associated with paraneoplastic syndromes, which may be misinterpreted. We report a case of a patient with occult small cell lung cancer that was initially compounded by clinical features of a paraneoplastic neurologic syndrome. The presence of antineuronal antibodies and positron emission tomography scan guided the search for the underlying tumor. Following chemo-radiotherapy the patient showed no evidence of disease for the next 18 months, whereas only a slight improvement in the neurologic disorders was observed. The course of the small cell lung cancer was very indolent and the paraneoplastic neurologic syndrome did not worsen with the use of cisplatin.
Subject(s)
Carcinoma, Small Cell/complications , Carcinoma, Small Cell/diagnosis , Lung Neoplasms/complications , Lung Neoplasms/diagnosis , Neoplasms, Unknown Primary/complications , Neoplasms, Unknown Primary/diagnosis , Nervous System Diseases/etiology , Paraneoplastic Syndromes/etiology , Ataxia/etiology , Autoantibodies/metabolism , Carcinoma, Small Cell/immunology , Dizziness/etiology , Encephalomyelitis/etiology , Humans , Lung Neoplasms/immunology , Male , Middle Aged , Neoplasms, Unknown Primary/immunology , Nervous System Diseases/immunology , Neurons/immunology , Nystagmus, Pathologic/etiology , Paraneoplastic Syndromes/immunology , Urinary Incontinence/etiologyABSTRACT
INTRODUCTION: Computer-assisted postprocessing was performed on selected digital dental radiographs using a professional software for photographic retouching. MATERIALS AND METHODS: The optical characteristics of 22 digital intraoral images (radio-videographies) taken on 18 patients were modified as regards their density and contrast values. Three different kinds of densitometric curves, corresponding to particular changes in post-processing parameters, were preliminary defined as the most effective for the demonstration of root canals and of alveolar bone. They were then applied to each X-ray image and the pictures thus modified were subsequently printed and read on a blind basis by three observers who considered the conspicuity of each structure of interest (root canals and alveolar bone). RESULTS: The results, submitted to statistical analysis, demonstrate that computer-assisted postprocessing can improve the visual yield and the diagnostic effectiveness of digital dental images in 67% of cases for the periapical bone and in 86% of cases for the root canals. CONCLUSIONS: The most effective sets of post-processing parameters established for each structure of interest are proposed together with a pre-programmed function to be introduced into the software of digital radiographic equipments.
Subject(s)
Image Processing, Computer-Assisted , Radiography, Dental, Digital , Adolescent , Adult , Aged , Alveolar Process/diagnostic imaging , Data Interpretation, Statistical , Dental Pulp Cavity/diagnostic imaging , Female , Humans , Male , Middle Aged , Periapical Tissue/diagnostic imaging , SoftwareABSTRACT
25 patients older than 65 years with metastatic breast cancer were treated with vinorelbine 30 mg/m2 i.v. days 1 and 8 every 3 weeks; the pharmacokinetics were studied in 10 of them. Vinorelbine showed a large apparent volume of distribution (mean 23.4 l/kg), a long terminal half-life (mean 26.2 h) and a large systemic clearance rate (mean 1.2 l/kg). These results are similar to those reported in younger patients. No correlation has been found between toxicity, age and drug exposure. We observed 6 partial responses out of 20 evaluable patients despite a relatively low mean dose intensity (67%). Severe neutropenia occurred in 37% of the patients; other side-effects were acceptable. This study does not provide a pharmacokinetic rationale for reducing the dosage of vinorelbine in selected elderly patients.
Subject(s)
Antineoplastic Agents, Phytogenic/pharmacokinetics , Breast Neoplasms/blood , Vinblastine/analogs & derivatives , Age Factors , Aged , Aged, 80 and over , Antineoplastic Agents, Phytogenic/blood , Antineoplastic Agents, Phytogenic/therapeutic use , Breast Neoplasms/drug therapy , Breast Neoplasms/pathology , Female , Humans , Neoplasm Metastasis , Vinblastine/blood , Vinblastine/pharmacokinetics , Vinblastine/therapeutic use , VinorelbineABSTRACT
A high-performance liquid chromatographic (HPLC) method with fluorescence detection for the determination of vinorelbine in plasma is described. The technique was derived from that published by Debal for an assay of vinorelbine in cell culture medium. The modifications concern the preparation procedure for plasma samples (a two-step liquid-liquid extraction from plasma is described), optimization of the mobile phase composition, and use of a single C18 column. These changes resulted in an improved sensitivity and reproducibility of the assay and led to its feasibility for clinical pharmacokinetic studies. The range of the assay is 2 to 1000 ng/ml.
Subject(s)
Antineoplastic Agents, Phytogenic/blood , Chromatography, High Pressure Liquid/methods , Vinblastine/analogs & derivatives , Antineoplastic Agents, Phytogenic/pharmacokinetics , Antineoplastic Agents, Phytogenic/therapeutic use , Breast Neoplasms/blood , Breast Neoplasms/drug therapy , Humans , Middle Aged , Reproducibility of Results , Sensitivity and Specificity , Spectrometry, Fluorescence , Vinblastine/blood , Vinblastine/pharmacokinetics , Vinblastine/therapeutic use , VinorelbineABSTRACT
BACKGROUND: The main elimination pathway of vinorelbine is hepatic metabolism, and the clearance of vinorelbine could be reduced in patients with liver metastases. OBJECTIVES: To study the pharmacokinetics of vinorelbine in patients who have advanced breast cancer with or without liver metastases and to study the relationship between hepatic function and vinorelbine clearance. PATIENTS AND METHODS: We studied 29 patients with advanced breast cancer: 19 with liver metastases and 10 control patients with extrahepatic metastases (mean age, 61 years; age range, 38 to 81 years). The vinorelbine dose was 30 mg/m2 as a short intravenous infusion; the dose was reduced by 50% in patients with bilirubin > 2 mg/dl. Patients were classified by ultrasonographic estimation of the liver volume replaced by tumor (%LVRT). Standard liver function tests and a monoethylglycinexylidide test (a quantitative liver function test based on lidocaine metabolite formation) were performed. Vinorelbine was assayed in plasma by HPLC with fluorescence detection. Vinorelbine determination was impossible in two patients with more than 75% LVRT because of interferences. Pharmacokinetic parameters were calculated with a noncompartimental method and compared by means of the Kruskal-Wallis test. RESULTS: A lower vinorelbine clearance rate was observed in the five patients with more than 75% LVRT (22.9 L/hr/m2) compared with the 10 patients with no liver metastases (48.0 L/hr/m2) and the 12 patients with 25% to 75% LVRT (45.3 L/hr/m2). Terminal elimination half-life and apparent volume of distribution were not significantly different among groups. The monoethylglycinexylidide test had a significant correlation with vinorelbine clearance. (r2 = 0.70; p = 10(-4). CONCLUSIONS: These results support vinorelbine dose reduction in patients with severe liver failure but not in patients with moderate secondary liver involvement. The monoethylglycinexylidide test may prove to be useful for vinorelbine dose individualization.
Subject(s)
Antineoplastic Agents, Phytogenic/pharmacokinetics , Breast Neoplasms/blood , Liver Neoplasms/blood , Vinblastine/analogs & derivatives , Adult , Aged , Aged, 80 and over , Antineoplastic Agents, Phytogenic/blood , Breast Neoplasms/drug therapy , Breast Neoplasms/pathology , Female , Half-Life , Humans , Lidocaine/analogs & derivatives , Liver Function Tests , Liver Neoplasms/drug therapy , Liver Neoplasms/secondary , Middle Aged , Vinblastine/blood , Vinblastine/pharmacokinetics , VinorelbineABSTRACT
Dynamic coupled-wave theory predicts the bending of recorded hologram phase planes in most photorefractive crystals. Bent holograms occur in LiNbO(3) and other photovoltaic crystals that are particularly interesting as holographic storage media and result in a reduced overall diffraction eff iciency. We show that hologram bending in LiNbO(3) can be avoided or at least sensibly reduced by use of an actively stabilized recording technique.
ABSTRACT
Five patients with metastatic renal cell cancer (RCC) entered this study. The patients received two courses of teniposide (VM26) (200 mg/m2/24 h i.v.) after which no objective response was observed: three patients had stable disease (SD) and two had progressive disease. Cyclosporine (CsA) (5 mg/kg/2 h followed by 30 mg/kg/48 h i.v.) was then added (VM26/CsA) and at least another two courses were administered. Pharmacokinetic and pharmacodynamic parameters were analyzed. CsA increased the area under curve (AUC) of VM26 in four out of five patients; on average, the variation in the paired AUC of VM26 was 41%. Nadir granulocyte count was lower (average 650/mm3, ranging from < 100 to 1800/mm3) after VM26/CsA than after VM26 (average 1260/mm3, ranging from 200 to 2100/mm3) (p < 0.01). Bilirubin concentration in the serum was increased after VM26/CsA compared with VM26 (p < 0.05). Finally, after two courses of VM26/CsA, four patients had stable disease and one patient had a minor response. In conclusion, the ongoing pilot study indicates that CsA affects both the pharmacokinetics and the pharmacodynamics of VM26.
Subject(s)
Carcinoma, Renal Cell/drug therapy , Cyclosporine/adverse effects , Kidney Neoplasms/drug therapy , Teniposide/pharmacokinetics , Aged , Bilirubin/metabolism , Cell Count/drug effects , Female , Granulocytes/drug effects , Humans , Male , Middle Aged , Pilot Projects , Teniposide/therapeutic useABSTRACT
AIMS AND BACKGROUND: A soluble form of intercellular adhesion molecule-1 (sICAM-1) has been recently identified in patients with malignant melanoma. It has been demonstrated that inflammatory cytokines can modulate the cellular expression of ICAM-1 and the shedding of this molecule by cells. To our knowledge, few data exist on serum sICAM-1 levels in cancer patients treated with immunomodulators. Liposomes containing muramyl tripeptide (MLV MTP-PE) can activate monocytes from cancer patients in vitro and in vivo, making them cytotoxic such as tumor necrosis factor-alpha (TNF-alpha) and Interleukin-6 (IL-6). The purpose of the present study was to evaluate the levels of sICAM-1 and their possible correlation with serum inflammatory cytokine levels in melanoma patients treated with MLV MTP-PE. METHODS: The sera from 9 patients with metastatic melanoma treated with MLV MTP-PE, 4 mg i.v. twice a week for 12 weeks, were tested in ELISA system to detect sICAM-1, TNF-alpha, IL-6, Interleukin-1 beta (IL-1 beta) and Interferon-gamma (IFN-gamma) before, and 2 and 24 h after the 1st, 12th and 24th infusion of MLV MTP-PE. RESULTS: Baseline levels of sICAM-1 were elevated in all patients (median 540 ng/ml: range 400-1030 ng/ml). Twenty-four h after the 1st infusion of MLV MTP-PE, we observed 6 increases in sICAM-1 levels, 1 decrease and 2 stable values (median 720 ng/ml: range 410-1820; P = 0.060). Twenty-four h after the 12th infusion, sICAM-1 increased in 3 patients and did not change in 4 (median 790 ng/ml: range 495-1650 ng/ml; P = 0.069). At the 24th infusion, sICAM-1 increased in 4 of 6 evaluable patients and remained stable in 2 (median 802 ng/ml: range 510-1450 ng/ml; P = 0.045). To better analyze the variations in sICAM-1, the patients were arbitrarily divided into two groups according to their clinical behavior: 4 presented stabilization (all lesions, n = 2; some lesions, n = 2) (Group A); 5 presented progressive disease (Group B). In Group A, sICAM-1 levels remained stable or showed a modest increase during treatment (except in 1 patient, who exhibited a substantial variation after the 12th infusion). In contrast, in Group B very high levels of sICAM-1 were observed at the beginning of the study therapy in 1 patient and after the 1st infusion in 3 patients; these values remained high until the 24th infusion. In most of the patients, TNF-alpha and IL-6 increased after the 1st infusion, but not thereafter. IFN-gamma was never detected; IL-1 beta was detectable in a few cases, but only before the infusions. CONCLUSIONS: baseline levels of sICAM-1 were elevated in all patients and further increased during treatment only in patients with more aggressive disease. No correlation was found between sICAM-1 and inflammatory cytokines. It would therefore seem that in patients with advanced disease, higher levels and a progressive increase in sICAM-1 may be unfavorable prognostic factors.
Subject(s)
Acetylmuramyl-Alanyl-Isoglutamine/analogs & derivatives , Antineoplastic Agents/administration & dosage , Cytokines/blood , Intercellular Adhesion Molecule-1/metabolism , Melanoma/drug therapy , Melanoma/metabolism , Acetylmuramyl-Alanyl-Isoglutamine/administration & dosage , Adult , Aged , Drug Carriers , Female , Humans , Liposomes , Male , Melanoma/blood , Middle AgedABSTRACT
Monocyte-mediated cytotoxicity (determined in a 72-h111In release assay) and the circulating levels of tumor necrosis factor alpha (TNF-alpha), interleukin (IL) 1beta, IL-6, IFN-gamma, C-reactive protein, and beta2-microglobulin were determined in 14 melanoma patients treated with multilamellar vesicle liposomes containing muramyl tripeptide phosphatidylethanolamine, 4 mg twice a week for 12 weeks. Monocyte-mediated cytotoxicity increased 24 h after the first infusion in 9 of 14 patients and had reached maximum levels (mean, 44% +/- 8) in all patients by the sixth week; similar values were observed at the 12th week. Once increased in vivo, peripheral blood monocyte cytotoxicity was not susceptible to any further increase after a subsequent in vitro incubation of the monocytes with liposomes. However, the peripheral blood monocytes which were not cytotoxic in vivo were activated by in vitro incubation with liposomes and not by medium. TNF-alpha and IL-6 peaked 2 h after the first infusion and returned to baseline values at 24 h; they were not significantly increased by subsequent treatments. The induction of fever in patients, observed 2 h after the first infusion, correlated with TNF-alpha and IL-6 levels. Similarly, C-reactive protein levels also increased at 24 h, but only after the first dose. No increase in beta2-microglobulin and IL-1beta levels was observed, and IFN-gamma was never detected in serum. Two patients experienced stable disease lasting 7 and 12 months, and 12 patients progressed. These results show that multilamellar vesicle muramyl tripeptide phosphatidylethanolamine administration activates monocyte cytotoxicity and cytokine production (TNF-alpha, IL-6). Chronic treatment with multilamellar vesicle muramyl tripeptide phosphatidylethanolamine results in tachyphylaxis in terms of cytokine secretion but not cytotoxicity. There was no difference between the maximum cytotoxicity levels obtained in vivo and those obtained in vitro using the same agent. A better understanding of immunoregulation is required for a rational application of this and related immunotherapies.
Subject(s)
Acetylmuramyl-Alanyl-Isoglutamine/analogs & derivatives , Antineoplastic Agents/therapeutic use , Cytokines/blood , Cytotoxicity, Immunologic , Melanoma/therapy , Monocytes/immunology , Phosphatidylethanolamines/therapeutic use , Acetylmuramyl-Alanyl-Isoglutamine/administration & dosage , Acetylmuramyl-Alanyl-Isoglutamine/therapeutic use , Adult , Aged , Antineoplastic Agents/administration & dosage , C-Reactive Protein/metabolism , Drug Carriers , Female , Humans , Infusions, Intravenous , Interferon-gamma/blood , Interleukin-1/blood , Interleukin-6/blood , Liposomes , Male , Melanoma/blood , Melanoma/immunology , Middle Aged , Phosphatidylethanolamines/administration & dosage , Tumor Necrosis Factor-alpha/metabolism , beta 2-Microglobulin/metabolismABSTRACT
We report an optoelectronic feedback loop that permits the active stabilization of an interferometric setup for any chosen value of the phase between the interfering beams. This method is based on phase modulation and homodyne detection techniques. The phase can be stabilized with a precision of better than 1 deg for our experimental conditions.
ABSTRACT
We report a simple actively stabilized setup for holographic recording on sillenite photorefractive crystals that is based on the anisotropic diffraction properties of these materials. The method is much simpler than previously published ones, requires neither phase modulation nor synchronous phase-sensitive detection, and needs no external reference. We describe the successful operation of this stabilization procedure for a Bi(12)TiO(20) crystal in a practical holographic interferometry setup, using the 632.8-nm wavelength of a He-Ne laser.