WorldWideScience

Sample records for anti-ganglioside gd2 antibodies

  1. Single Chain Fv Constructs of Anti-Ganglioside GD2 Antibodies for Radioimaging and Radioimmunotherapy

    International Nuclear Information System (INIS)

    of its broad and usually homogeneous distribution in human solid tumors, and most importantly, their absence on cell membranes of normal human tissues. In separate experiments, we have shown that T-cells transduced with the herpes simplex viral thymidine kinase (HSV-tk) gene can be radiolabeled with 131I-FIAU to a safe nuclear radiation dose. Using a dicistronic construct we are inserting chimeric immune receptor plus HSV-tk into T-cells to allow such their trafficking to be radioactively monitored. We plan to study the role of cytokines, chemoreceptors and CD4 helper T-cells in recruiting CD8+ transduced T-cells to the tumor site. These studies should provide us with an adoptive cell therapy approach to target cytotoxicity to human tumors, and a lymphocyte tracking tool to study delivery to the tumor sites, to determine if they proliferate locally and/or recirculate. Such pharmacologic information is crucial for optimizing gene-modified T-cells in future clinical trials. Single chain FV constructs of anti-ganglioside GD2 antibodies for radioimaging

  2. Endothelin A receptor antagonism enhances inhibitory effects of anti-ganglioside GD2 monoclonal antibody on invasiveness and viability of human osteosarcoma cells.

    Directory of Open Access Journals (Sweden)

    Bo Liu

    Full Text Available Endothelin-1 (ET-1/endothelin A receptor (ETAR signaling is important for osteosarcoma (OS progression. Monoclonal antibodies (mAbs targeting ganglioside GD2 reportedly inhibit tumor cell viability independent of the immune system. A recent study suggests that ganglioside GD2 may play an important role in OS progression. In the present study, we for the first time explored the effects of anti-GD2 mAb alone or in combination with ETAR antagonist on OS cell invasiveness and viability. Human OS cell lines Saos-2, MG-63 and SJSA-1 were treated with control IgG (PK136 mAb, 50 µg/mL, anti-GD2 14G2a mAb (50 µg/mL, selective ETAR antagonist BQ123 (5 µM, or 14G2a (50 µg/mL+BQ123 (5 µM. Cells with knockdown of ETAR (ETAR-shRNA with or without 14G2a mAb treatment were also tested. Cells treated with selective phosphatidylinositide 3-kinase (PI3K inhibitor BKM120 (50 µM were used as a positive control. Our results showed that BQ123, ETAR-shRNA and 14G2a mAb individually decreased cell invasion and viability, matrix metalloproteinase-2 (MMP-2 expression and activity, PI3k activity, and phosphorylation at serine 473 (ser473 of Akt in OS cells. 14G2a mAb in combination with BQ123 or ETAR-shRNA showed significantly stronger inhibitory effects compared with each individual treatment. In all three cell lines tested, 14G2a mAb in combination with BQ123 showed the strongest inhibitory effects. In conclusion, we provide the first in vitro evidence that anti-ganglioside GD2 14G2a mAb effectively inhibits cell invasiveness, MMP-2 expression and activity, and cell viability in human OS cells. ETAR antagonist BQ123 significantly enhances the inhibitory effects of 14G2a mAb, likely mainly through inhibiting the PI3K/Akt pathway. This study adds novel insights into OS treatment, which will serve as a solid basis for future in vivo studies on the effects of combined treatment of OS with anti-ganglioside GD2 mAbs and ETAR antagonists.

  3. Anti-ganglioside antibodies in amyotrophic lateral sclerosis revisited.

    Directory of Open Access Journals (Sweden)

    Katja Kollewe

    Full Text Available Amyotrophic Lateral Sclerosis (ALS is a devastating neurodegenerative disorder with typical onset in the 5th- 6th decade of life. The hypothesis of an autoimmune origin of ALS receives less attention today, but immunological phenomena still seem to be involved and mechanisms such as protective autoimmunity may be important. Detection of antibodies against a variety of gangliosides has been repeatedly described in ALS-patients by several authors, but widely differing frequencies and titres have been reported. Therefore, we investigated the presence of six common antibodies with a commercially available test panel for GA1, GM1, GM2, GD1a, GD1b and GQ1b in a large group of clinically well-characterized ALS patients and compared them to a collective of 200 healthy blood donors.IgG and IgM antibodies to the six gangliosides asialoGM1 (GA1, GM1, GM2, GD1a, GD1b, GQ1b were determined by GanglioCombi ELISA in sera of 84 ALS patients. Results were expressed as a %-ratio of a highly positive control and categorized as negative (100%. The values obtained from 200 Swiss blood donors served as a reference group.In twenty-two (26.2% ALS-patients elevated anti-ganglioside antibodies could be detected: Taking all subspecific antibodies together, IgG antibodies were found in 9/84 (10.7% and IgM in 15/84 (17.9% patients. There was no correlation between age, gender, site of onset or survival and anti-ganglioside-positive/-negative titres in ALS-patients. No statistically significant difference in the frequency of anti-ganglioside antibodies compared to the group of healthy blood donors was found.Even with this more comprehensive approach, anti-ganglioside antibody frequencies and patterns in our ALS cohort closely resembled the values measured in healthy controls. In accordance with other studies, we did not observe any association of a distinct ALS phenotype with elevated anti-ganglioside antibodies or an impact on survival.

  4. Anti-ganglioside antibodies in patients with Guillain Barré syndrome and other neurological disorders

    Directory of Open Access Journals (Sweden)

    C Vaishnavi

    2013-01-01

    Full Text Available A study was performed on 59 Guillain-Barré syndrome (GBS cases, 58 neurological controls (NC and 60 non-neurological controls (NNC to investigate the association of anti-ganglioside antibodies in GBS and other neurological disorders. Campylobacter jejuni was isolated from 5.7% of GBS patients. Anti-ganglioside immunoglobulin G was present in 82% and immunoglobulin M in 46% in acute inflammatory demyelinating polyneuropathy patients, 70% and 44% respectively in acute motor axonal neuropathy subgroup and 38% each in acute motor sensory axonal neuropathy subgroup. Though high intensity of anti-gangliosides was present in the GBS patients, the NC patients also had adequate anti-gangliosides compared with the NNC group.

  5. Anti-Ganglioside antibodies in Guillain-Barre Syndrome : Do They indicate Prognosis?

    Directory of Open Access Journals (Sweden)

    Menon Ashok

    2003-01-01

    Full Text Available This study aimed to detect anti-ganglioside antibodies in the sera of patients with Guillain-Barre syndrome and correlate their presence with clinical features, electrophysiological studies and outcome. Twenty patients with GBS were evaluated clinically and electrophysiologically. Serological assays for antibodies against GM1, GD1a and GD1b gangliosides were carried out by ELISA, Twelve patients tested positive; two had antibodies against all three gangliosides, one against both GM1 and GD1a, one against GM1, GD1a or GD1b alone were seen in two, five and one patient respectively. No significant correlation was noted between the presence or type of antibody with clinical features, electrophysiological findings and outcome.

  6. Dissecting the Role of Anti-ganglioside Antibodies in Guillain-Barré Syndrome: an Animal Model Approach.

    Science.gov (United States)

    Asthana, Pallavi; Vong, Joaquim Si Long; Kumar, Gajendra; Chang, Raymond Chuen-Chung; Zhang, Gang; Sheikh, Kazim A; Ma, Chi Him Eddie

    2016-09-01

    Guillain-Barré syndrome (GBS) is an autoimmune polyneuropathy disease affecting the peripheral nervous system (PNS). Most of the GBS patients experienced neurological symptoms such as paresthesia, weakness, pain, and areflexia. There are also combinations of non-neurological symptoms which include upper respiratory tract infection and diarrhea. One of the major causes of GBS is due largely to the autoantibodies against gangliosides located on the peripheral nerves. Gangliosides are sialic acid-bearing glycosphingolipids consisting of a ceramide lipid anchor with one or more sialic acids attached to a neutral sugar backbone. Molecular mimicry between the outer components of oligosaccharide of gangliosides on nerve membrane and lipo-oligosaccharide of microbes is thought to trigger the autoimmunity. Intra-peritoneal implantation of monoclonal ganglioside antibodies secreting hybridoma into animals induced peripheral neuropathy. Recent studies demonstrated that injection of synthesized anti-ganglioside antibodies raised by hybridoma cells into mice initiates immune response against peripheral nerves, and eventually failure in peripheral nerve regeneration. Accumulating evidences indicate that the conjugation of anti-ganglioside monoclonal antibodies to activating FcγRIII present on the circulating macrophages inhibits axonal regeneration. The activation of RhoA signaling pathways is also involved in neurite outgrowth inhibition. However, the link between these two molecular events remains unresolved and requires further investigation. Development of anti-ganglioside antagonists can serve as targeted therapy for the treatment of GBS and will open a new approach of drug development with maximum efficacy and specificity. PMID:26374552

  7. Immunotherapy with GD2 specific monoclonal antibodies

    International Nuclear Information System (INIS)

    Targeted immunotherapy focuses anti-tumor activity of antibodies and effector cells, which are actively developed by the host or adoptively transferred, onto tumor cells and into tumor sites. Such tumor selective therapy can be more specific and efficient. The value of such an approach is evident in the classical interaction of antibodies. This paper reports that the ganglioside GD2 is an ideal antigen for specific tumor targeting because of its relative lack of heterogeneity among human neuroblastoma, its high density on tumor cells, its lack of antigen modulation upon binding to antibody, and its restricted distribution in normal tissues

  8. Anti-ganglioside antibody-induced tumor cell death by loss of membrane integrity.

    Science.gov (United States)

    Roque-Navarro, Lourdes; Chakrabandhu, Krittalak; de León, Joel; Rodríguez, Sandra; Toledo, Carlos; Carr, Adriana; de Acosta, Cristina Mateo; Hueber, Anne-Odile; Pérez, Rolando

    2008-07-01

    Gangliosides have been involved in multiple cellular processes such as growth, differentiation and adhesion, and more recently as regulators of cell death signaling pathways. Some of these molecules can be considered as tumor-associated antigens, in particular, N-glycolyl sialic acid-containing gangliosides, which are promising candidates for cancer-targeted therapy because of their low expression in normal human tissues. In this study, we provided the molecular and cellular characterization of a novel cell death mechanism induced by the anti-NGcGM3 14F7 monoclonal antibody (mAb) in L1210 murine tumor cell line but not in mouse normal cells (B and CD4(+) T lymphocytes) that expressed the antigen. Impairment of ganglioside synthesis in tumor cells abrogated the 14F7 mAb cytotoxic effect; however, exogenous reincorporation of the ganglioside did not restore tumor cell sensitivity to 14F7 mAb-induced cytotoxicity. 14F7 F(ab')(2) but not Fab fragments retained the cytotoxic capacity of the whole mAb. By contrary, other mAb, which recognizes N-glycolylated gangliosides, did not show any cytotoxic effect. These mAbs showed quite different capacities to bind NGcGM3-positive cell lines measured by binding inhibition experiments. Interestingly, this complement-independent cell death mechanism did not resemble apoptosis, because no DNA fragmentation, caspase activation, or Fas mediation were observed. However, NGcGM3 ganglioside-mediated 14F7 mAb-induced cell death was accompanied by cellular swelling, membrane lesion formation, and cytoskeleton activation, suggesting an oncosis-like phenomenon. This novel mechanism of cell death lets us to support further therapeutic approaches using NGcGM3 as a molecular target for antibody-based cancer immunotherapy. PMID:18645013

  9. Correlations between cytomegalovirus, Epstein-Barr virus, anti-ganglioside antibodies, electrodiagnostic findings and functional status in Guillain-Barré syndrome.

    Directory of Open Access Journals (Sweden)

    Aliakbar Taheraghdam

    2014-03-01

    Full Text Available Due to underlying autoimmune background of Guillain-Barré syndrome (GBS, the possible role of infectious agents cytomegalovirus (CMV and Epstein-Barr virus (EBV and also due to association of anti-ganglioside antibodies with GBS, the present study aimed to investigate the associations between serum anti-ganglioside antibodies (AGA level, type of infection and electrodiagnostic (ED findings with the severity and three-month functional outcome of patients with GBS.In a prospective study, 30 patients with GBS were selected and before starting the treatment, baseline serum samples of patients were obtained for measuring the serum AGA including the antibodies against GQ1b, GT1b, GD1a, GD1b, GM1, GM2, GM3 and strains of CMV and EBV. All the patients were precisely examined for ED findings. Functional status of patients on admission and three months after admission were recorded according to the modified Rankin scale (mRS.The results of patients' serum assessment revealed that CMV IgM was positive in one patient (3.3%, CMV IgG in 29 patients (96.7% and EBV IgG in 27 patients (90%. Anti-GM1 was found in 3 patients (10% and anti-GM3 was found only in one patient (3.3%. However, no statistical significant association was found between the AGA and strain of the disease and ED findings.Despite the coexistence of AGA and serum antibodies against CMV and EBV in some GBS patients, there was not clear association in this regard. However, the AGA was positive in patients who suffered from severe phase of the disease.

  10. Bickerstaff’s brainstem encephalitis, Miller Fisher syndrome and Guillain-Barré syndrome overlap in an asthma patient with negative anti-ganglioside antibodies

    Directory of Open Access Journals (Sweden)

    Han Chongyu

    2012-06-01

    Full Text Available Abstract Background Bickerstaff’s brainstem encephalitis (BBE, together with Miller Fisher syndrome (MFS and Guillain-Barré syndrome (GBS were considered to form a continuous clinical spectrum. An anti-GQ1b antibody syndrome has been proposed to underlie the common pathophysiology for the three disorders; however, other studies have found a positive anti-GM1 instead of anti-GQ1b antibody. Case presentation Here we report a 20-year-old male patient with overlapping BBE, MFS and GBS. The patient had a positive family history of bronchial asthma and had suffered from the condition for over 15 years. He developed BBE symptoms nine days after an asthma exacerbation. During the course of illness, he had significantly elevated IgE levels in both serum and cerebrospinal fluid. Serologic analysis of antibodies against ganglioside complexes (anti-GDIa, anti-GDIb, anti-GM1, anti-GM2, anti-GM3, anti-GQIb and anti-GTIb antibodies showed negative results. Conclusions Since asthma has recently been related to autoimmune disease, our case supports an autoimmune mechanism underlying the clinical spectrum composed of BBE, MFS and GBS. However, contrary to a proposed anti-GQ1b antibody syndrome, we would suggest that pathogenesis of this clinical spectrum is not limited to anti-ganglioside antibodies.

  11. A cytotoxic humanized anti-ganglioside antibody produced in a murine cell line defective of N-glycolylated-glycoconjugates.

    Science.gov (United States)

    Fernández-Marrero, Yuniel; Roque-Navarro, Lourdes; Hernández, Tays; Dorvignit, Denise; Molina-Pérez, Marively; González, Addys; Sosa, Katya; López-Requena, Alejandro; Pérez, Rolando; de Acosta, Cristina Mateo

    2011-12-01

    Gangliosides containing the N-glycolyl (NGc) form of sialic acid are tumor-associated antigens and promising candidates for cancer therapy. We previously generated the murine 14F7 monoclonal antibody (mAb), specific for the N-glycolyl-GM3 ganglioside (NGcGM3), which induced an oncosis-like type of cell death on malignant cell lines expressing this antigen and recognized breast carcinoma by immunoscintigraphy in cancer patients. As humanization is expected to enhance its use for human cancer therapy, herein we describe the design and generation of two humanized versions of the 14F7 mAb by disrupting potential human T cell epitopes on its variable region. No differences in antigen reactivity or cytotoxic properties were detected among the variants tested and with respect to the chimeric counterpart. Humanized 14F7 genes were transfected into the NGcGM3-expressing NS0 cell line. Therefore, in the industrial scaling-up of the transfectoma in serum-free medium, cell viability was lost due to the cytotoxic effect of the secreted antibody. This shortcoming was solved by knocking down the CMP-N-acetylneuraminic acid hydroxylase enzyme, thus impairing the synthesis of NGc-glycoconjugates. Humanized 14F7 mAb is of potential value for the therapy of NGcGM3-expressing tumors. PMID:21802167

  12. Ganglioside GD2-specific trifunctional surrogate antibody Surek demonstrates therapeutic activity in a mouse melanoma model

    Directory of Open Access Journals (Sweden)

    Ruf Peter

    2012-11-01

    Full Text Available Abstract Background Trifunctional bispecific antibodies (trAb are a special class of bispecific molecules recruiting and activating T cells and accessory immune cells simultaneously at the targeted tumor. The new trAb Ektomab that targets the melanoma-associated ganglioside antigen GD2 and the signaling molecule human CD3 (hCD3 on T cells demonstrated potent T-cell activation and tumor cell destruction in vitro. However, the relatively low affinity for the GD2 antigen raised the question of its therapeutic capability. To further evaluate its efficacy in vivo it was necessary to establish a mouse model. Methods We generated the surrogate trAb Surek, which possesses the identical anti-GD2 binding arm as Ektomab, but targets mouse CD3 (mCD3 instead of hCD3, and evaluated its chemical and functional quality as a therapeutic antibody homologue. The therapeutic and immunizing potential of Surek was investigated using B78-D14, a B16 melanoma transfected with GD2 and GD3 synthases and showing strong GD2 surface expression. The induction of tumor-associated and autoreactive antibodies was evaluated. Results Despite its low affinity of approximately 107 M-1 for GD2, Surek exerted efficient tumor cell destruction in vitro at an EC50 of 70ng/ml [0.47nM]. Furthermore, Surek showed strong therapeutic efficacy in a dose-dependent manner and is superior to the parental GD2 mono-specific antibody, while the use of a control trAb with irrelevant target specificity had no effect. The therapeutic activity of Surek was strictly dependent on CD4+ and CD8+ T cells, and cured mice developed a long-term memory response against a second challenge even with GD2-negative B16 melanoma cells. Moreover, tumor protection was associated with humoral immune responses dominated by IgG2a and IgG3 tumor-reactive antibodies indicating a Th1-biased immune response. Autoreactive antibodies against the GD2 target antigen were not induced. Conclusion Our data suggest that Surek revealed

  13. Bickerstaff’s brainstem encephalitis, Miller Fisher syndrome and Guillain-Barré syndrome overlap in an asthma patient with negative anti-ganglioside antibodies

    OpenAIRE

    Han Chongyu; Wang Yuan; Jia Jianping; Ji Xunming; Fredrickson Vance; Ding Yuchuan; Sun Wei; Xu Jia; Sun Yong-Xin

    2012-01-01

    Abstract Background Bickerstaff’s brainstem encephalitis (BBE), together with Miller Fisher syndrome (MFS) and Guillain-Barré syndrome (GBS) were considered to form a continuous clinical spectrum. An anti-GQ1b antibody syndrome has been proposed to underlie the common pathophysiology for the three disorders; however, other studies have found a positive anti-GM1 instead of anti-GQ1b antibody. Case presentation Here we report a 20-year-old male patient with overlapping BBE, MFS and GBS. The pat...

  14. Anti-Neuroblastoma Activity of Gold Nanorods Bound with GD2 Monoclonal Antibody under Near-Infrared Laser Irradiation

    Directory of Open Access Journals (Sweden)

    Ching-An Peng

    2011-01-01

    Full Text Available High-risk neuroblastoma is one of the most common deaths in pediatric oncology. Current treatment of this disease involves a coordinated sequence of chemotherapy, surgery, and radiation. Further advances in therapy will require the targeting of tumor cells in a more selective and efficient way so that survival can be improved without substantially increasing toxicity. To achieve tumor-selective delivery, disialoganglioside (GD2 expressed by almost all neuroblastoma tumors represents a potential molecular target that can be exploited for tumor-selective delivery. In this study, GD2 monoclonal antibody (anti-GD2 was conjugated to gold nanorods (GNRs which are one of anisotropic nanomaterials that can absorb near-infrared (NIR laser light and convert it to energy for photothermolysis of tumor cells. Thiolated chitosan, due to its biocompatibility, was used to replace cetyltrimethylammonium bromide (CTAB originally used in the synthesis of gold nanorods. In order to specifically target GD2 overexpressed on the surface of neuroblastoma stNB-V1 cells, anti-GD2 was conjugated to chitosan modified GNRs (CGNRs. To examine the fate of CGNRs conjugated with anti-GD2 after incubation with neuroblastoma cells, rhadoamine B was labeled on CGNRs functionalized with anti-GD2. Our results illustrated that anti-GD2-conjugated CGNRs were extensively endocytosed by GD2+ stNB-V1 neuroblastoma cells via antibody-mediated endocytosis. In addition, we showed that anti-GD2 bound CGNRs were not internalized by GD2– SH-SY5Y neuroblastoma cells. After anti-GD2-linked CGNRs were incubated with neuroblatoma cells for six hours, the treated cells were further irradiated with 808 nm NIR laser. Post-NIR laser exposure, when examined by calcein-AM dye, stNB-V1 cells all underwent necrosis, while non-GD2 expressing SH-SY5Y cells all remained viable. Based on the in vitro study, CGNRs bound with anti-GD2 has the potential to be utilized as a therapeutic thermal coupling agent

  15. Anti-Neuroblastoma Activity of Gold Nanorods Bound with GD2 Monoclonal Antibody under Near-Infrared Laser Irradiation

    International Nuclear Information System (INIS)

    High-risk neuroblastoma is one of the most common deaths in pediatric oncology. Current treatment of this disease involves a coordinated sequence of chemotherapy, surgery, and radiation. Further advances in therapy will require the targeting of tumor cells in a more selective and efficient way so that survival can be improved without substantially increasing toxicity. To achieve tumor-selective delivery, disialoganglioside (GD2) expressed by almost all neuroblastoma tumors represents a potential molecular target that can be exploited for tumor-selective delivery. In this study, GD2 monoclonal antibody (anti-GD2) was conjugated to gold nanorods (GNRs) which are one of anisotropic nanomaterials that can absorb near-infrared (NIR) laser light and convert it to energy for photothermolysis of tumor cells. Thiolated chitosan, due to its biocompatibility, was used to replace cetyltrimethylammonium bromide (CTAB) originally used in the synthesis of gold nanorods. In order to specifically target GD2 overexpressed on the surface of neuroblastoma stNB-V1 cells, anti-GD2 was conjugated to chitosan modified GNRs (CGNRs). To examine the fate of CGNRs conjugated with anti-GD2 after incubation with neuroblastoma cells, rhadoamine B was labeled on CGNRs functionalized with anti-GD2. Our results illustrated that anti-GD2-conjugated CGNRs were extensively endocytosed by GD2+ stNB-V1 neuroblastoma cells via antibody-mediated endocytosis. In addition, we showed that anti-GD2 bound CGNRs were not internalized by GD2− SH-SY5Y neuroblastoma cells. After anti-GD2-linked CGNRs were incubated with neuroblatoma cells for six hours, the treated cells were further irradiated with 808 nm NIR laser. Post-NIR laser exposure, when examined by calcein-AM dye, stNB-V1 cells all underwent necrosis, while non-GD2 expressing SH-SY5Y cells all remained viable. Based on the in vitro study, CGNRs bound with anti-GD2 has the potential to be utilized as a therapeutic thermal coupling agent that generates

  16. In silico driven redesign of a clinically relevant antibody for the treatment of GD2 positive tumors.

    Directory of Open Access Journals (Sweden)

    Mahiuddin Ahmed

    Full Text Available Ganglioside GD2 is a cell surface glycolipid that is highly expressed on cancer cells of neuroectodermal origin, including neuroblastoma, retinoblastoma, melanoma, sarcomas, brain tumors and small cell lung cancer. Monoclonal antibodies (MoAb that target GD2 have shown clinical efficacy in the treatment of GD2 expressing tumors, and are expected to be the new standard of care for the treatment of pediatric neuroblastoma. In this study, the crystal structure of anti-GD2 murine MoAb 3F8 was solved to 1.65 Å resolution and used as a template for molecular docking simulations of its antigen, the penta-saccharide head group of GD2. Molecular docking revealed a binding motif composed of 12 key interacting amino acid side-chains, involving an extensive network of interactions involving main-chain and side-chain hydrogen bonding, two Pi-CH interactions, and an important charged interaction between Arg95 of the H3 loop with the penultimate sialic acid residue of GD2. Based on in silico scanning mutagenesis of the 12 interacting amino acids from the docked 3F8:GD2 model, a single point mutation (Heavy Chain: Gly54Ile was engineered into a humanized 3F8 (hu3F8 MoAb and found to have a 6-9 fold enhancement in antibody-dependent cell-mediated cytotoxicity of neuroblastoma and melanoma cell lines. With enhanced tumor-killing properties, the re-engineered hu3F8 has the potential be a more effective antibody for the treatment of GD2-positive tumors.

  17. Anti-GD2 with an FC point mutation reduces complement fixation and decreases antibody-induced allodynia

    OpenAIRE

    Sorkin, Linda S.; Otto, Mario; Baldwin, William M.; Vail, Emily; Gillies, Stephen D.; Handgretinger, Rupert; Barfield, Raymond C.; Yu, Hui Ming; Yu, Alice L.

    2010-01-01

    Monoclonal antibodies against GD2 ganglioside, such as ch14.18, the human–mouse chimeric antibody, have been shown to be effective for the treatment of neuroblastoma. However, treatment is associated with generalized, relatively opiate-resistant pain. We investigated if a point mutation in ch14.18 antibody (hu14.18K332A) to limit complement-dependent cytotoxicity (CDC) would ameliorate the pain behavior, while preserving antibody-dependent cellular cytotoxicity (ADCC). In vitro, CDC and ADCC ...

  18. Tumor targeting of the IL-15 superagonist RLI by an anti-GD2 antibody strongly enhances its antitumor potency.

    Science.gov (United States)

    Vincent, Marie; Bessard, Anne; Cochonneau, Denis; Teppaz, Géraldine; Solé, Véronique; Maillasson, Mike; Birklé, Stéphane; Garrigue-Antar, Laure; Quéméner, Agnès; Jacques, Yannick

    2013-08-01

    Immunocytokines (ICKs) targeting cytokines to the tumor environment using antibodies directed against a tumor-associated antigen often have a higher therapeutic index than the corresponding unconjugated cytokines. Various ICKs displaying significant antitumoral effects in several murine tumor models have already been developed, and some of them, in particular interleukin (IL)-2-based ICKs, are in Phase II clinical trials. Although sharing common biological activities with IL-2 in vitro, IL-15 is now considered as having a better potential in antitumor immunotherapeutical strategies and has been shown to be less toxic than IL-2 in preclinical studies. We previously developed the fusion protein RLI, linking a soluble form of human IL-15Rα-sushi+ domain to human IL-15. RLI showed better biological activities than IL-15 in vitro as well as higher antitumoral effects in vivo in murine and human cancer models. Here, we investigated, in the context of an ICK, the effect of associating RLI with an antibody targeting the GD2 ganglioside, a validated tumoral target expressed on many neurectodermal tumors. Anti-GD2-RLI fully retained the cytokine potential of RLI and the antibody effector functions (antibody-dependent cellular cytotoxicity and complement-dependent cytotoxicity). It displayed strong antitumor activities in two syngeneic cancer models in immunocompetent mice (subcutaneous EL4 and metastatic NXS2). Its therapeutic potency was higher than those of RLI and anti-GD2 alone or in combination. We suggest that this is related to its bifunctional (cytokine and antibody) nature. PMID:23354868

  19. Titration of serum anti-ganglioside antibodies in patients with chronic medular injury previous to treatment with GM1 ganglioside Titulação de anticorpos anti-gangliosídeos no soro de pacientes com lesão medular crônica e precedendo tratamento com gangliosídeo GM1

    Directory of Open Access Journals (Sweden)

    Tarcísio Eloy Pessoa Barros Filho

    2003-04-01

    Full Text Available Anti-ganglioside serum titers were evaluated by ELISA in 150 patients with complete spinal cord lesion for 6 to 12 months (IgG monosialo GM1, IgM monosialo GM1, IgG asialo GM1, IgM asialo GM1, IgG disialo GD1b e IgM disialo GD1b prior to treatment with GM1 100 mg/day i.m. Only 4 patients showed positive titers for anti-asialo-GM1 (IgM antibodies . All patients were clinically examined during and after treatment. No important side effects were observed with GM1 therapy. These results suggest that GM1-ganglioside administration in patients with chronic spinal cord injury is safe.Soro de 150 pacientes com lesão medular completa com 6 a 12 meses de duração foi analisado para titulação de anticorpos anti-gangliosídeos pelo método ELISA (IgG monosialo GM1, IgM monosialo GM1, IgG asialo GM1, IgM asialo GM1, IgG disialo GD1b e IgM disialo GD1b. Somente 4 pacientes apresentaram títulos elevados de anticorpos contra asialo GM1 (IgM. Os demais apresentaram níveis de anticorpos abaixo dos valores de referência e foram todos tratados com GM1 na dose de 100 mg por dia i.m. Todos os pacientes foram acompanhados clinicamente durante e após o tratamento com GM1. Não foram observados efeitos adversos importantes com a medicação. O tratamento de pacientes lesados medulares crônicos com o gangliosídeo GM1 mostrou-se seguro, nos pontos sem positividade sorológica para anticorpos anti-GM1 .

  20. Anti-GD(2) with an FC point mutation reduces complement fixation and decreases antibody-induced allodynia.

    Science.gov (United States)

    Sorkin, Linda S; Otto, Mario; Baldwin, William M; Vail, Emily; Gillies, Stephen D; Handgretinger, Rupert; Barfield, Raymond C; Ming Yu, Hui; Yu, Alice L

    2010-04-01

    Monoclonal antibodies against GD(2) ganglioside, such as ch14.18, the human-mouse chimeric antibody, have been shown to be effective for the treatment of neuroblastoma. However, treatment is associated with generalized, relatively opiate-resistant pain. We investigated if a point mutation in ch14.18 antibody (hu14.18K332A) to limit complement-dependent cytotoxicity (CDC) would ameliorate the pain behavior, while preserving antibody-dependent cellular cytotoxicity (ADCC). In vitro, CDC and ADCC were measured using europium-TDA assay. In vivo, allodynia was evaluated by measuring thresholds to von Frey filaments applied to the hindpaws after injection of either ch14.18 or hu14.18K332 into wild type rats or rats with deficient complement factor 6. Other rats were pretreated with complement factor C5a receptor antagonist and tested following ch14.18 injection. The mutation reduces the antibody's ability to activate complement, while maintaining its ADCC capabilities. Injection of hu14.18K322 (1 or 3mg/kg) produced faster resolving allodynia than that engendered by ch14.18 (1mg/kg). Injection of ch14.18 (1mg/kg) into rats with C6 complement deficiency further reduced antibody-induced allodynia, while pre-treatment with complement factor C5a receptor antagonist completely abolished ch14.18-induced allodynia. These findings showed that mutant hu14.18 K322 elicited less allodynia than ch14.18 and that ch14.18-elicited allodynia is due to activation of the complement cascade: in part, to formation of membrane attack complex, but more importantly to release of complement factor C5a. Development of immunotherapeutic agents with decreased complement-dependent lysis while maintaining cellular cytotoxicity may offer treatment options with reduced adverse side effects, thereby allowing dose escalation of therapeutic antibodies. PMID:20171010

  1. Iodine 131 labeled GD2 monoclonal antibody in the diagnosis and therapy of human neuroblastoma

    International Nuclear Information System (INIS)

    High dose marrow ablative therapy followed by autologous bone marrow transplantation (ABMT) has prolonged survival in patients with neuroblastoma. Total body and focal irradiation play an integral role in the overall treatment of this disease. The biological basis for radiation is the radiosensitivity and the lack of sublethal repair in neuroblastoma cells. However, radiation therapy has not by itself been adequate because of the usual widespread nature of neuroblastoma and the inability to achieve selective tumor versus normal tissue delivery, especially at multiple tumor sites. Monoclonal antibodies are agents selected for their specificity for human tumors. In vivo they have the ability of targeting selectively to occult metastases. This paper discusses how the availability of radioisotopes and the development of conjugation chemistries have greatly expanded the potentials of these antibodies

  2. Generation and Characterization of a Human/Mouse Chimeric GD2-Mimicking Anti-Idiotype Antibody Ganglidiximab for Active Immunotherapy against Neuroblastoma.

    Directory of Open Access Journals (Sweden)

    Christin Eger

    Full Text Available Vaccination with proteins mimicking GD2 that is highly expressed on neuroblastoma (NB cells is a promising strategy in treatment of NB, a pediatric malignancy with poor prognosis. We previously showed efficacy of ganglidiomab in vivo, a murine anti-idiotype (anti-Id IgG1. In order to tailor immune responses to variable regions, we generated a new human/mouse chimeric anti-Id antibody (Ab ganglidiximab by replacing murine constant fragments with corresponding human IgG1 regions. DNA sequences encoding for variable regions of heavy (VH and light chains (VL were synthesized by RT-PCR from total RNA of ganglidiomab-producing hybridoma cells and further ligated into mammalian expression plasmids with coding sequences for constant regions of human IgG1 heavy and light chains, respectively. We established a stable production cell line using Chinese hamster ovarian (CHO cells co-transfected with two expression plasmids driving the expression of either ganglidiximab heavy or light chain. After purification from supernatants, anti-idiotypic characteristics of ganglidiximab were demonstrated. Binding of ganglidiximab to anti-GD2 Abs of the 14.18 family as well as to NK-92tr cells expressing a GD2-specific chimeric antigen receptor (scFv(ch14.18-zeta was shown using standard ELISA and flow cytometry analysis, respectively. Ganglidiximab binding affinities to anti-GD2 Abs were further determined by surface plasmon resonance technique. Moreover, binding of anti-GD2 Abs to the nominal antigen GD2 as well as GD2-specific Ab-mediated cytotoxicity (ADCC, CDC was competitively inhibited by ganglidiximab. Finally, ganglidiximab was successfully used as a protein vaccine in vivo to induce a GD2-specific humoral immune response. In summary, we report generation and characterization of a new human/mouse chimeric anti-Id Ab ganglidiximab for active immunotherapy against NB. This Ab may be useful to tailor immune responses to the paratope regions mimicking GD2

  3. A recombinant antibody-interleukin 2 fusion protein suppresses growth of hepatic human neuroblastoma metastases in severe combined immunodeficiency mice.

    OpenAIRE

    Sabzevari, H; Gillies, S D; Mueller, B M; Pancook, J D; Reisfeld, R A

    1994-01-01

    A genetically engineered fusion protein consisting of a human/mouse chimeric anti-ganglioside GD2 antibody (ch14.18) and recombinant human interleukin 2 (rhIL-2) was tested for its ability to target rhIL-2 to tumor sites and stimulate immune effector cells sufficiently to achieve effective tumor cell lysis in vivo. The ch14.18-IL-2 fusion protein proved more effective than equivalent doses of rhIL-2 in suppressing dissemination and growth of human neuroblastoma in an experimental hepatic meta...

  4. 99mTc-monoclonal antibody radiolabeled via hydrazino nicotinamide derivative for imaging disialoganglioside GD2-positive tumors

    International Nuclear Information System (INIS)

    3F8 is a murine IgG3 monoclonal antibody (MAb) selective for the ganglioside GD2. Previous studies using 131I-3F8 have shown great potential in the imaging of neuroectodermal tumors and the therapy of human neuroblastoma. 131I is commonly used in radioimmunodiagnosis, but its relatively long half-life (8 days) and its high energy γ-emission (364 KeV) are suboptimal for imaging purposes when compared with 99mTc (6 h and 140 KeV, respectively). To label 3F8 with 99mTc, the antibody was first coupled with a heterobifunctional linker, succinimidyl-6-hydrazinonicotinate hydrochloride (SHNH), obtaining a hydrazinonicotinamide-antibody conjugate. Using 99mTc-Tricine as the precursor complex, 3F8-SHNH was coupled efficiently to 99mTc, resulting in >90% radiometal incorporation, with a specific activity >10 mCi/mg and retaining full immunoreactivity. Immunoscintigraphy at 6, 22, and 46 h after intravenous injection of 1 mCi of 99mTc-3F8 showed selective neuroblastoma localization in xenografted nude mice, comparable to that obtained with the injection of 100 μCi of 131I-3F8. Biodistribution studies of 131I-3F8 and 99mTc-3F8 in mice demonstrated comparable %ID/g uptake in tumor (with a T/B ratio: ∼2.5 at 24 h and ∼3.5 at 48 h) and normal organs, including blood, except for spleen and liver which had about a three times higher uptake of the 99mTc conjugate. In conclusion, 99mTc can be coupled conveniently at high specific activity to 3F8 without compromising immunoreactivity. SHNH appears to be a useful linker for 99mTc in tumor diagnostic imaging and may have potential utility in coupling other radioisotopes (e.g., 94mTc) for positron imaging and therapy

  5. Ganglioside GD2 in reception and transduction of cell death signal in tumor cells

    International Nuclear Information System (INIS)

    Ganglioside GD2 is expressed on plasma membranes of various types of malignant cells. One of the most promising approaches for cancer immunotherapy is the treatment with monoclonal antibodies recognizing tumor-associated markers such as ganglioside GD2. It is considered that major mechanisms of anticancer activity of anti-GD2 antibodies are complement-dependent cytotoxicity and/or antibody-mediated cellular cytotoxicity. At the same time, several studies suggested that anti-GD2 antibodies are capable of direct induction of cell death of number of tumor cell lines, but it has not been investigated in details. In this study we investigated the functional role of ganglioside GD2 in the induction of cell death of multiple tumor cell lines by using GD2-specific monoclonal antibodies. Expression of GD2 on different tumor cell lines was analyzed by flow cytometry using anti-GD2 antibodies. By using HPTLC followed by densitometric analysis we measured the amount of ganglioside GD2 in total ganglioside fractions isolated from tumor cell lines. An MTT assay was performed to assess viability of GD2-positive and -negative tumor cell lines treated with anti-GD2 mAbs. Cross-reactivity of anti-GD2 mAbs with other gangliosides or other surface molecules was investigated by ELISA and flow cytometry. Inhibition of GD2 expression was achieved by using of inhibitor for ganglioside synthesis PDMP and/or siRNA for GM2/GD2 and GD3 synthases. Anti-GD2 mAbs effectively induced non-classical cell death that combined features of both apoptosis and necrosis in GD2-positive tumor cells and did not affect GD2-negative tumors. Anti-GD2 mAbs directly induced cell death, which included alteration of mitochondrial membrane potential, induction of apoptotic volume decrease and cell membrane permeability. This cytotoxic effect was mediated exclusively by specific binding of anti-GD2 antibodies with ganglioside GD2 but not with other molecules. Moreover, the level of GD2 expression correlated with

  6. Generation of human monoclonal antibodies against ganglioside antigens and their applications in the diagnosis and therapy of cancer

    Energy Technology Data Exchange (ETDEWEB)

    Alfonso, M. [Dept. of Tumor Cell Biology, Div. of Cancer Biology, Danish Cancer Society, Copenhagen (Denmark)]|[Dept. of Research and Development, Center of Molecular Immunology, Havana (Cuba); Zeuthen, J. [Dept. of Tumor Cell Biology, Div. of Cancer Biology, Danish Cancer Society, Copenhagen (Denmark)

    1996-10-01

    Different approaches to generating human monoclonal antibodies (MAbs) against tumor-associated ganglioside antigens have been carried out in several laboratories. A specific goal addressed by our laboratory is to produce human MAbs to several ganglioside antigens of relevance as therapeutic targets, such as the GM2, GD2, GD3 and GM3 gangliosides in melanoma. In vitro immunization of human B lymphocytes from normal donors was performed using liposomes containing gangliosides as the immunizing antigen combined with either complete tetanus toxoid or a synthetic peptide corresponding to a T helper epitope to stimulate in vitro immunization. Specific human anti-ganglioside antibodies were obtained, indicating that the antibdoy response found in vitro was antigen-driven. To overcome the widely reported problems concerning stability of immunoglobulin production by the antibody-secreting cell lines, a method of positive selection using GM3-coated magnetic beads has been developed in order to rescue unstable clones. Development of new methods to reproducibly generate ganglioside-specific human MAbs will amplify the possibilities for diagnostic and therapeutic applications. (orig.).

  7. Generation of human monoclonal antibodies against ganglioside antigens and their applications in the diagnosis and therapy of cancer

    International Nuclear Information System (INIS)

    Different approaches to generating human monoclonal antibodies (MAbs) against tumor-associated ganglioside antigens have been carried out in several laboratories. A specific goal addressed by our laboratory is to produce human MAbs to several ganglioside antigens of relevance as therapeutic targets, such as the GM2, GD2, GD3 and GM3 gangliosides in melanoma. In vitro immunization of human B lymphocytes from normal donors was performed using liposomes containing gangliosides as the immunizing antigen combined with either complete tetanus toxoid or a synthetic peptide corresponding to a T helper epitope to stimulate in vitro immunization. Specific human anti-ganglioside antibodies were obtained, indicating that the antibdoy response found in vitro was antigen-driven. To overcome the widely reported problems concerning stability of immunoglobulin production by the antibody-secreting cell lines, a method of positive selection using GM3-coated magnetic beads has been developed in order to rescue unstable clones. Development of new methods to reproducibly generate ganglioside-specific human MAbs will amplify the possibilities for diagnostic and therapeutic applications. (orig.)

  8. Anti-ganglioside anti-idiotypic vaccination: more than molecular mimicry.

    Directory of Open Access Journals (Sweden)

    Ana María eHernández

    2012-11-01

    Full Text Available Surgery, chemotherapy, and radiation therapy are standard modalities for cancer treatment, but the effectiveness of these treatments has reached a plateau. Thus, other strategies are being explored to combine with the current treatment paradigms in order to reach better clinical results. One of these approaches is the active immunotherapy based on the induction of anti-tumor responses by anti-idiotypic vaccination. This approach arose from Jerne’s idiotypic network theory, which postulates that B lymphocytes forms a functional network, with a role in the establishment of the immune repertoires, in the regulation of natural antibody production and even in the establishment of natural tolerance. Due to the large potential diversity of the immunoglobulin variable regions, the idiotypes repertoire can mimic the universe of self and foreign epitopes, even those of non-protein nature, like gangliosides. Gangliosides are sialic acid-containing glycolipids that have been considered attractive targets for cancer immunotherapy, based on the qualitative and quantitative changes they suffer during malignant transformation and due to their importance for tumor biology. Although any idiotype could be able to mimic any antigen, only those related to antigens involved in functions relevant for organism homeostasis, and that in consequence has been fixed by evolution, would be able not only to mimic, but also to activate the idiotypic cascades related with the nominal antigen. The present review updates the results, failures and hopes, obtained with ganglioside mimicking anti-idiotypic antibodies and presents evidences of the existence of a natural response against gangliosides, suggesting that these glycolipids could be idiotypically relevant antigens.

  9. Expression of GD2 and GD3 gangliosides in human embryonic neural stem cells

    Directory of Open Access Journals (Sweden)

    Makoto Yanagisawa

    2011-04-01

    Full Text Available NSCs (neural stem cells are undifferentiated neural cells endowed with a high potential for proliferation and a capacity for self-renewal with retention of multipotency to differentiate into neurons and glial cells. It has been recently reported that GD3, a b-series ganglioside, is a marker molecule for identifying and isolating mouse NSCs. However, the expression of gangliosides in human NSCs is largely unknown. In the present study, we analysed the expression of gangliosides, GD2 and GD3, in human NSCs that were isolated from human brains at gestational week 17 in the form of neurospheres, which are floating clonal aggregates formed by NSCs in vitro. Employing immunocytochemistry, we found that human NSCs were strongly reactive to anti-GD2 antibody and relatively weakly reactive to anti-GD3 antibody. Treatment of these cells with an organic solvent such as 100% methanol, which selectively removes glycolipids from plasma membrane, abolished the immunoreactivity with those antibodies, indicating that the reactivity was due to GD2 and GD3, but not to GD2-/GD3-like glycoproteins or proteoglycans. The immunoreactivity of human NSCs to antibody against SSEA-1 (stage-specific embryonic antigen-1, a well-known carbohydrate antigen of NSCs, was not decreased by the treatment with 100% methanol, indicating that SSEA-1 is mainly carried by glycoproteins and/or proteoglycans in human NSCs. Our study suggests that GD2 and GD3 can be marker gangliosides for identifying human NSCs.

  10. Gd-2 fuel cycle Benchmark (version 1)

    International Nuclear Information System (INIS)

    The new benchmark based on Dukovany NPP Unit-3 history of Gd-2 fuel type utilisation is defined. The main goal of this benchmark is to compare results obtained by different codes used for neutron-physics calculation. Input data are described in this paper including initial state definition. Requested output data format for automatic processing is defined. This paper includes: a) fuel description b) definition of starting point and five fuel cycles with profiled fuel 3.82% only c) definition of four fuel cycles with fuel Gd-2 (enr.4.25%) d) recommendation for calculation e) list of parameters for comparison f) methodology of comparison g) an example of results comparison (Authors)

  11. An Optimized GD2-Targeting Retroviral Cassette for More Potent and Safer Cellular Therapy of Neuroblastoma and Other Cancers.

    Science.gov (United States)

    Thomas, Simon; Straathof, Karin; Himoudi, Nourredine; Anderson, John; Pule, Martin

    2016-01-01

    Neuroblastoma is the commonest extra cranial solid cancer of childhood. Despite escalation of treatment regimens, a significant minority of patients die of their disease. Disialoganglioside (GD2) is consistently expressed at high-levels in neuroblastoma tumors, which have been targeted with some success using therapeutic monoclonal antibodies. GD2 is also expressed in a range of other cancer but with the exception of some peripheral nerves is largely absent from non-transformed tissues. Chimeric Antigen Receptors (CARs) are artificial type I proteins which graft the specificity of a monoclonal antibody onto a T-cell. Clinical data with early CAR designs directed against GD2 have shown some promise in Neuroblastoma. Here, we describe a GD2-targeting CAR retroviral cassette, which has been optimized for CAR T-cell persistence, efficacy and safety. PMID:27030986

  12. Antiganglioside antibodies in Guillain-Barré syndrome after a recent cytomegalovirus infection

    OpenAIRE

    Khalili-Shirazi, A.; Gregson, N.; Gray, I.; Rees, J.; Winer, J; Hughes, R

    1999-01-01

    OBJECTIVE—To study the association between anti-ganglioside antibody responses and Guillan-Barré syndrome (GBS) after a recent cytomegalovirus (CMV) infection.
METHODS—Enzyme linked immunosorbant assay (ELISA) was undertaken on serum samples from 14 patients with GBS with recent cytomegalovirus (CMV) infection (CMV+GBS) and 12 without (CMV-GBS), 17 patients with other neurological diseases (OND), 11 patients with a recent CMV infection but without neurological involvement, 1...

  13. Localization of the Gangliosides GD2 and GD3 in Adhesion Plaques and on the Surface of Human Melanoma Cells

    Science.gov (United States)

    Cheresh, David A.; Harper, John R.; Schulz, Gregor; Reisfeld, Ralph A.

    1984-09-01

    The predominant gangliosides produced by two cultured human melanoma cell lines are GD3 and/or GD2. These gangliosides were found to be cell associated and present in substratum-attached material after cell removal by EDTA. Monoclonal antibodies directed to GD2 and GD3 specified the cell-surface distribution of these gangliosides and localized them in focal adhesion plaques at the interface of cells and their substratum. These attachment sites did not represent indiscriminant membrane fragments remaining after removal of cells with EDTA, because neither melanoma-associated proteoglycan nor class I histocompatibility antigens were detected by their respective antibodies. Our data suggest that the disialogangliosides GD2 and GD3 may be involved in the interaction between human melanoma cells and solid substrata.

  14. Neutronic analysis of Gd2O3 as burnable poison

    International Nuclear Information System (INIS)

    For the reactors core design, the use of burnable poisons is one of the options for the control of in excess reactivity and the power form factor. As alternative procedures, the absorbing material may be included in pellets of an inert material or in fuel pellets. Besides, a cladding material and the locations of the fuel elements must be chosen for the first case. The CAREM reactor core design foresees the use of gadolinium oxide (Gd2O3) as burnable poison. In this work, a comparative study was made, from the neutronic point of view, among the following alternatives for the poisons location: a) Gd2O3 bars supports in alumina (Al2O3), sheathed in steel; b) Gd2O3 bars supports in alumina sheathed in Zry-4; c) Gd2O3 in uranium dioxide (UO2) fuel pellets. (Author)

  15. Potential dual imaging nanoparticle: Gd2O3 nanoparticle

    OpenAIRE

    Ahmad, Md. Wasi; Xu, Wenlong; Kim, Sung June; Baeck, Jong Su; Chang, Yongmin; Bae, Ji Eun; Chae, Kwon Seok; Park, Ji Ae; Kim, Tae Jeong; Lee, Gang Ho

    2015-01-01

    Gadolinium (Gd) is a unique and powerful element in chemistry and biomedicine which can be applied simultaneously to magnetic resonance imaging (MRI), X-ray computed tomography (CT), and neutron capture therapy for cancers. This multifunctionality can be maximized using gadolinium oxide (Gd2O3) nanoparticles (GNPs) because of the large amount of Gd per GNP, making both diagnosis and therapy (i.e., theragnosis) for cancers possible using only GNPs. In this study, the T1 MRI and CT dual imaging...

  16. Gadolinium scandium germanide, Gd2Sc3Ge4

    Directory of Open Access Journals (Sweden)

    Sumohan Misra

    2009-04-01

    Full Text Available Gd2Sc3Ge4 adopts the orthorhombic Pu5Rh4-type structure. The crystal structure contains six sites in the asymmetric unit: two sites are statistically occupied by rare-earth atoms with Gd:Sc ratios of 0.967 (4:0.033 (4 and 0.031 (3:0.969 (3, one site (.m. symmetry is occupied by Sc atoms, and three distinct sites (two of which with .m. symmetry are occupied by Ge atoms. The rare-earth atoms form two-dimensional slabs with Ge atoms occupying the trigonal-prismatic voids.

  17. Gadolinium scandium germanide, Gd2Sc3Ge4

    OpenAIRE

    Sumohan Misra; Miller, Gordon J.

    2009-01-01

    Gd2Sc3Ge4 adopts the orthorhombic Pu5Rh4-type structure. The crystal structure contains six sites in the asymmetric unit: two sites are statistically occupied by rare-earth atoms with Gd:Sc ratios of 0.967 (4):0.033 (4) and 0.031 (3):0.969 (3), one site (.m. symmetry) is occupied by Sc atoms, and three distinct sites (two of which with .m. symmetry) are occupied by Ge atoms. The rare-earth atoms form two-dimensional slabs with Ge atoms occupying the tri...

  18. L X-Rays RYIED Oscillations and Proton-NMRD of Gd2O3 Nanoparticles

    Directory of Open Access Journals (Sweden)

    A. Taborda

    2011-01-01

    variations still present different patterns for Gd2O3 pellet and Gd2O3 nanoparticles. Proton NMRD T1(ω data for Gd2O3 nanoparticles and Gd-DOTA water solutions published by Bridot et al. and Toth et al., respectively, were reproduced using a model for paramagnetic substances in water solutions and identical electronic relaxation times. The analysis of both techniques results points collective electron behaviour as the explanation for the different observations on X-ray data of Gd2O3 nanoparticles and bulk material.

  19. A route to obtain Gd2O3:Nd3+ with different particle size

    International Nuclear Information System (INIS)

    Research highlights: → Thermogravimetric behavior of the precursor Gd2(OH)2(CO3).nH2O:Nd3+ (2 at%) is presented and discussed. → Structural and spectroscopic investigation of theGd2O3:Nd3+ powders revealed that this phosphor displays a band emission in the infrared region. → The treatment with different EDTA concentrations results in different Gd2O3:Nd3+ particle size. - Abstract: This work reports the chemical etching effect of ethylenediaminetetraacetic acid (H4EDTA) on the particle size of Gd2O3:Nd3+ phosphor obtained from the thermal decomposition of Gd2(OH)2(CO3).nH2O:Nd3+. Thermogravimetric behavior of the precursor Gd2(OH)2(CO3).nH2O:Nd3+ (2 at%) is presented and discussed. Structural and spectroscopic investigation of the Gd2O3:Nd3+ powders revealed that this phosphor displays a band emission in the infrared region, which is an important feature for photonic applications. The treatment with different EDTA concentrations results in different Gd2O3:Nd3+ particle size. Through SEM analysis, we have demonstrated that the particle size of Gd2O3:Nd3+ decreases with increasing amount of EDTA. Hereby, we report a chemical etching method as a route to obtain particle size control which is an important requirement to improve phosphor properties and its applicability.

  20. Antibody

    Science.gov (United States)

    An antibody is a protein produced by the body's immune system when it detects harmful substances, called antigens. Examples ... microorganisms (bacteria, fungi, parasites, and viruses) and chemicals. Antibodies may be produced when the immune system mistakenly ...

  1. Synthesis of UO2 and ThO2 doped with Gd2O3

    International Nuclear Information System (INIS)

    Uranium dioxide (urania, UO2) and thorium dioxide (thoria, ThO2) doped with gadolinium oxide (gadolinia, Gd2O3) were prepared via solid-state synthesis. For Gd2O3-doped ThO2, also an alternative, semi-dry process (“suspension coating”) was applied in which Gd2O3-coated ThO2 powder was produced via suspension drying followed by calcination. The microstructure and homogeneity of the materials were investigated by ceramography, EPMA and XRD. Solid-state synthesis is a convenient method to produce Gd2O3-doped UO2. However, this route was found to be inappropriate to obtain Gd2O3-doped ThO2 with an acceptable microstructure and homogeneity. The suspension coating process reported in this work is a simple and practical method to overcome these issues

  2. Synthesis and Characterization of Gd2O3 Hollow Microspheres Using a Template-Directed Method

    Directory of Open Access Journals (Sweden)

    Xueliang Jiang

    2016-04-01

    Full Text Available Uniform rare-earth gadolinium oxide (Gd2O3 hollow microspheres, as formed through a urea-assisted homogenous precipitation process using carbon spheres as a template and a subsequent heat treatment, were characterized by using X-ray diffraction, Fourier transformed infared spectroscopy, thermogravimetry, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy and Brunauer-Emmett-Tellet surface area measurement. The results indicate that the final products can be indexed to a cubic Gd2O3 phase with high purity and have a uniform morphology at 500 nm in diameter and 20 nm in shell thickness. The as-synthesized Gd2O3 hollow microspheres exhibited a superior photooxidation activity to that of Gd2O3 powder and an effect similar to P25, significantly broadening the potential of Gd2O3 hollow microspheres for many practical applications.

  3. The ganglioside antigen GD2 is surface-expressed in Ewing sarcoma and allows for MHC-independent immune targeting

    OpenAIRE

    Kailayangiri, S; Altvater, B; Meltzer, J; Pscherer, S; Luecke, A.; Dierkes, C. (Christian); Titze, U; Leuchte, K; Landmeier, S. (Silke); Hotfilder, M; Dirksen, U; Hardes, J.; Gosheger, G.; Juergens, H; Rossig, C.

    2012-01-01

    Background: Novel treatment strategies are needed to cure disseminated Ewing sarcoma. Primitive neuroectodermal features and a mesenchymal stem cell origin are both compatible with aberrant expression of the ganglioside antigen GD2 and led us to explore GD2 immune targeting in this cancer. Methods: We investigated GD2 expression in Ewing sarcoma by immunofluorescence staining. We then assessed the antitumour activity of T cells expressing a chimeric antigen receptor specific for GD2 against E...

  4. Phase equilibria in BaS-Cu2S-Gd2S3 system

    International Nuclear Information System (INIS)

    Phase equilibria in BaS-Cu2S-Gd2S3 system are studied along isothermal (800 K) and polythermal sections CuGdS2-BaS, Cu2S-BaGdCuS3, BaGdCuS3-Gd2S3, BaGdCuS3-BaGd2S4. Complex sulfide BaGdCuS3 with orthorhombic lattice is formed, lattice parameters are determined. Compositions of eutectics forming in the system are determined

  5. Gd2O3 nanoparticles stabilized by hydrothermally modified dextrose for positive contrast magnetic resonance imaging

    Science.gov (United States)

    Babić-Stojić, Branka; Jokanović, Vukoman; Milivojević, Dušan; Požek, Miroslav; Jagličić, Zvonko; Makovec, Darko; Arsikin, Katarina; Paunović, Verica

    2016-04-01

    Gd2O3 nanoparticles of a few nm in size and their agglomerates dispersed in dextrose derived polymer template were synthesized by hydrothermal treatment. The produced nanosized material was investigated by TEM, FTIR spectroscopy, SQUID measurements and NMR relaxometry. Biological evaluation of this material was done by crystal violet and MTT assays to determine the cell viability. Longitudinal and transverse NMR relaxivities of water diluted Gd2O3 nanoparticle dispersions measured at the magnetic field of 1.5 T, estimated to be r1(Gd2O3)=9.6 s-1 mM-1 in the Gd concentration range 0.1-30 mM and r2(Gd2O3)=17.7 s-1 mM-1 in the lower concentration range 0.1-0.8 mM, are significantly higher than the corresponding relaxivities measured for the standard contrast agent r1(Gd-DTPA)=4.1 s-1 mM-1 and r2(Gd-DTPA)=5.1 s-1 mM-1. The ratio of the two relaxivities for Gd2O3 nanoparticles r2/r1=1.8 is suitable for T1-weighted imaging. Good MRI signal intensities of the water diluted Gd2O3 nanoparticle dispersions were recorded at lower Gd concentrations 0.2-0.8 mM. The Gd2O3 samples did not exert any significant cytotoxic effects at Gd concentrations of 0.2 mM and below. These properties of the produced Gd2O3 nanoparticles in hydrothermally modified dextrose make them promising for potential application in MRI for the design of a positive MRI contrast agent.

  6. Photocatalytic Water Splitting for Hydrogen Production with Gd2MSbO7 (M = Fe, In, Y Photocatalysts under Visible Light Irradiation

    Directory of Open Access Journals (Sweden)

    Jingfei Luan

    2014-12-01

    Full Text Available Novel photocatalysts Gd2FeSbO7, Gd2InSbO7 and Gd2YSbO7 were synthesized by the solid state reaction method for the first time. A comparative study about the structural and photocatalytic properties of Gd2MSbO7 (M = Fe, In, Y was reported. The results showed that Gd2FeSbO7, Gd2InSbO7 and Gd2YSbO7 crystallized with the pyrochlore-type structure, cubic crystal system and space group Fd3m. The lattice parameter a for Gd2FeSbO7, Gd2InSbO7 or Gd2YSbO7 was 10.276026 Å, 10.449546 Å or 10.653651 Å. The band gap of Gd2FeSbO7, Gd2InSbO7 or Gd2YSbO7 was estimated to be 2.151 eV, 2.897 eV or 2.396 eV. For the photocatalytic water-splitting reaction, H2 or O2 evolution was observed from pure water with Gd2FeSbO7, Gd2InSbO7 or Gd2YSbO7 as catalyst under visible light irradiation (wavelength > 420 nm. Moreover, H2 or O2 also spilt by using Gd2FeSbO7, Gd2InSbO7 or Gd2YSbO7 as catalyst from CH3OH/H2O or AgNO3/H2O solutions under visible light irradiation (λ > 420 nm. Gd2FeSbO7 showed the highest activity compared with Gd2InSbO7 or Gd2YSbO7. At the same time, Gd2InSbO7 showed higher activity compared with Gd2YSbO7. The photocatalytic activities were further improved under visible light irradiation with Gd2FeSbO7, Gd2InSbO7 or Gd2YSbO7 being loaded by Pt, NiO or RuO2. The effect of Pt was better than that of NiO or RuO2 for improving the photocatalytic activity of Gd2FeSbO7, Gd2InSbO7 or Gd2YSbO7.

  7. Pulse electrodeposited Ni-Gd2O3 nanocomposite electrode as electrocatalysts for ethanol electro-oxidation

    International Nuclear Information System (INIS)

    Highlights: • Ni-Gd2O3 nanocomposite electrodes are prepared from sulphamate solutions using pulse method. • Ni-Gd2O3 nanocomposites are characterized with SEM, EDAX, XRD and AFM. • Electrocatalytic activity of the Ni-Gd2O3 nanocomposite electrodes are studied using Cyclic voltammetry and chronoamperometry techniques. - Abstract: In this work, pure Ni and Ni-Gd2O3 nanocomposites are deposited on mild steel surface using nickel sulphamate electrolyte by pulse electrodeposition method. The effect of Gd2O3 nano particles concentration on the preferred orientation of Ni-Gd2O3 nanocomposite was studied by X-ray diffractrometer. The surface morphology, surface topography and chemical composition of deposited pure Ni and Ni-Gd2O3 nanocomposite was characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM) and energy dispersive X-ray spectroscopy (EDAX) respectively. The electrocatalytic activity of the pure Ni and Ni-Gd2O3 nanocomposite electrodes for the electro-oxidation of ethanol was studied by cyclic voltammetry and chronoamperometry. The results showed that, Ni-Gd2O3 nanocomposite electrode increases the electrocatalytic activity towards ethanol electro-oxidation compared with pure Ni. However, the chronoamperometry experiments revealed that the stability of the Ni-Gd2O3 composite electrodes with time is found to be equivalent to pure Ni electrode

  8. The ganglioside antigen GD2 is surface-expressed in Ewing sarcoma and allows for MHC-independent immune targeting

    Science.gov (United States)

    Kailayangiri, S; Altvater, B; Meltzer, J; Pscherer, S; Luecke, A; Dierkes, C; Titze, U; Leuchte, K; Landmeier, S; Hotfilder, M; Dirksen, U; Hardes, J; Gosheger, G; Juergens, H; Rossig, C

    2012-01-01

    Background: Novel treatment strategies are needed to cure disseminated Ewing sarcoma. Primitive neuroectodermal features and a mesenchymal stem cell origin are both compatible with aberrant expression of the ganglioside antigen GD2 and led us to explore GD2 immune targeting in this cancer. Methods: We investigated GD2 expression in Ewing sarcoma by immunofluorescence staining. We then assessed the antitumour activity of T cells expressing a chimeric antigen receptor specific for GD2 against Ewing sarcoma in vitro and in vivo. Results: Surface GD2 was detected in 10 out of 10 Ewing sarcoma cell lines and 3 out of 3 primary cell cultures. Moreover, diagnostic biopsies from 12 of 14 patients had uniform GD2 expression. T cells specifically modified to express the GD2-specific chimeric receptor 14. G2a-28ζ efficiently interacted with Ewing sarcoma cells, resulting in antigen-specific secretion of cytokines. Moreover, chimeric receptor gene-modified T cells from healthy donors and from a patient exerted potent, GD2-specific cytolytic responses to allogeneic and autologous Ewing sarcoma, including tumour cells grown as multicellular, anchorage-independent spheres. GD2-specific T cells further had activity against Ewing sarcoma xenografts. Conclusion: GD2 surface expression is a characteristic of Ewing sarcomas and provides a suitable target antigen for immunotherapeutic strategies to eradicate micrometastatic cells and prevent relapse in high-risk disease. PMID:22374462

  9. Structure and optical properties of sol-gel derived Gd2O3 waveguide films

    International Nuclear Information System (INIS)

    Pure and rare earth doped gadolinium oxide (Gd2O3) waveguide films were prepared by a simple sol-gel process and dip-coating method. Gd2O3 was successfully synthesized by hydrolysis of gadolinium acetate. Thermogravimetric analysis (TGA) and differential thermal analysis (DTA) were used to study the thermal chemistry properties of dried gel. Structure of Gd2O3 films annealed at different temperature ranging from 400 to 750 deg. C were investigated by Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results show that Gd2O3 starts crystallizing at about 400 deg. C and the crystallite size increases with annealing temperature. Oriented growth of (4 0 0) face of Gd2O3 has been observed when the films were deposited on (1 0 0) Si substrate and annealed at 750 deg. C. The laser beam (λ=632.8 nm) was coupled into the film by a prism coupler and propagation loss of the film measured by scattering-detection method is about 2 dB/cm. Luminescence properties of europium ions doped films were measured and are discussed

  10. Study on the low-temperature properties of pyrochlores Gd2Hf2O7 and Gd2Zr2O7, using crystal-field theory

    Science.gov (United States)

    Ali Biswas, Aksar; Jana, Yatramohan

    2011-07-01

    The geometrically frustrated pyrochlores Gd2Hf2O7 (GdH) and Gd2Zr2O7 (GdZ) are easy planar anisotropic systems in which considerable single-ion crystal-field anisotropies of D3d symmetry are found in the ground multiplet 8S7/2 due to admixture of higher Russell-Saunders terms. The 8S7/2 splits into 4 doublets with total CF splitting 9.9 K in GdH and 9.4 K in GdZ. The magnetic specific heat Cmag follows a conventional T3 behavior in GdH and an unconventional T4.6 behavior in GdZ down to 0.4 K.

  11. Study on the low-temperature properties of pyrochlores Gd2Hf2O7 and Gd2Zr2O7 using crystal-field theory

    International Nuclear Information System (INIS)

    The geometrically frustrated pyrochlores Gd2Hf2O7 (GdH) and Gd2Zr2O7 (GdZ) are easy planar anisotropic systems in which considerable single-ion crystal-field anisotropies of D3d symmetry are found in the ground multiplet 8S7/2 due to admixture of higher Russell-Saunders terms. The 8S7/2 splits into 4 doublets with total CF splitting 9.9 K in GdH and 9.4 K in GdZ. The magnetic specific heat Cmag follows a conventional T3 behavior in GdH and an unconventional T4.6 behavior in GdZ down to 0.4 K. (author)

  12. Evaluation of the rare earth impurities determination in Gd2O3 matrix by ICP OES

    International Nuclear Information System (INIS)

    The ternary U-Rare Earth-O systems are involved in the nuclear technology due to their application as burnable poison in PWR type reactors. Chemical and physical characterization of both constituents, uranium dioxide (UO2) and gadolinium oxide (Gd2O3), used in the burnable poison production, has a special interest. Inductively coupled plasma optic emission spectrometry (ICP OES) is suitable for the determination of the rare earth elements (REEs) due to its high sensibility. However, REEs have many spectral emission lines hence most of them suffer from spectral interferences due to other REEs and impurities elements. In this work spectral lines REEs interferences and other impurities elements were investigated in Gd2O3 matrix. The sensibility of each selected line and interference lines were determinated. Detection limits and linearity were presented. Validation of the method was carried out mainly with recovery studied in the Gd2O3 spiked matrix. (author)

  13. Photocatalytic Water Splitting for Hydrogen Production with Gd2MSbO7 (M = Fe, In, Y) Photocatalysts under Visible Light Irradiation

    OpenAIRE

    Jingfei Luan; Yanyan Li

    2014-01-01

    Novel photocatalysts Gd2FeSbO7, Gd2InSbO7 and Gd2YSbO7 were synthesized by the solid state reaction method for the first time. A comparative study about the structural and photocatalytic properties of Gd2MSbO7 (M = Fe, In, Y) was reported. The results showed that Gd2FeSbO7, Gd2InSbO7 and Gd2YSbO7 crystallized with the pyrochlore-type structure, cubic crystal system and space group Fd3m. The lattice parameter a for Gd2FeSbO7, Gd2InSbO7 or Gd2YSbO7 was 10.276026 Å, 10.449546 Å or 10.653651 Å. ...

  14. The magnetic phase diagram of Gd2Sn2O7

    International Nuclear Information System (INIS)

    Measurements of the magnetic susceptibility of the frustrated pyrochlore magnet Gd2Sn2O7 have been performed at temperatures below T = 5 K and in magnetic fields up to H = 12 T. The phase boundaries determined from these measurements are mapped out in an H-T phase diagram. In this gadolinium compound, where the crystal-field splitting is small and the exchange and dipolar energy are comparable, the Zeeman energy overcomes these competing energies, resulting in at least four magnetic phase transitions below 1 K. These data are compared against those for Gd2Ti2O7 and will, we hope, stimulate further studies.

  15. Synthesis and luminescent properties of nanoscale Gd2Si2O7:Eu3+ phosphors.

    Science.gov (United States)

    Li, Yong; Wang, Chao-Nan; Wei, Xian-Tao; Zhao, Jiang-Bo; Zhang, Wei-Ping; Yin, Min

    2010-03-01

    Gd2Si2O7:Eu3+ nanoparticles were prepared by the sol-gel method with citric acid as an additive in the precursor solutions. The crystal structure was analyzed by means of X-ray diffraction (XRD). The results indicate that the alpha-Gd2Si2O7 powders in size 35 nm are obtained at a synthesis temperature of 1,100 degrees C, and the doping ion contents do not influence the crystal structure. The excitation and emission spectra of samples were measured. The dependence of photoluminescence intensity and lifetime of level on Eu3+ concentration and synthesis temperature of samples are also discussed. PMID:20355659

  16. Magnetic relaxation behaviour in Gd2-xYxPdSi3 alloys

    International Nuclear Information System (INIS)

    The results of time-dependent remanent magnetization (MIRM) behaviour (magnetic relaxation studies) in polycrystalline Gd2-xYxPdSi3 alloys in a magnetically ordered state are reported. We observed that MIRM undergoes slow relaxation with time. We have also measured ac susceptibility as a function of frequency; however, we did not find any upward shift of the peak-temperature with an increase of frequency, which suggests that these alloys are not spin-glasses. Measurements on single-crystalline Gd2PdSi3 show that the magnetic relaxation is an intrinsic property of the materials. (author). Letter-to-the-editor

  17. Synthesis and characterization of hollow nanoparticles of crystalline Gd2O3

    International Nuclear Information System (INIS)

    Although Gd2O3 (gadolinia) nanoparticle is the subject of intense research interest due to its magnetic property as well as controllable emission wavelengths by doping of various lanthanide ions, it is known to be difficult to prepare monodisperse crystalline gadolinia nanoparticles because it requires high temperature thermal annealing process to enhance the crystallinity. In this article, we demonstrate the synthesis of hollow nanoparticles of crystalline Gd2O3 by employing poly(N-vinylpyrrolidone) (PVP) to stabilize the surface of Gd(OH)CO3·H2O nanoparticles and to successively form SiO2 shell as a protecting layer to prevent aggregation during calcinations processes. Silica shells could be selectively removed after calcinations by a treatment with basic solution to give hollow nanoparticles of crystalline Gd2O3. The formation mechanism of hollow nanoparticles could be suggested based on several characterization results of the size and shape, and crystallinity of Gd2O3 nanoparticles by TEM, SEM, and XRD.

  18. Modifications of local structures of Gd2O3 on incorporation of SiO2

    International Nuclear Information System (INIS)

    In the present work we have reported the results of investigations on local structures of e-beam evaporated (Gd2O3-SiO2) composite thin films by synchrotron based EXAFS measurements. The evolution of local structure in the case of the Gd2O3-SiO2 system is found to be different from the HfO2-SiO2 system reported by us earlier. The EXAFS analysis has shown that the Gd-O bond length decreases monotonically as SiO2 content in the films increases. Also the amplitudes of the peaks in the FT-EXAFS spectra of the samples, which depend jointly on the coordination numbers as well as the Debye-Waller factors (measure of disorder) are found to decrease monotonically with increase in SiO2 contents in the Gd2O3 matrix. Atomic force microscopy (AFM) measurements of the samples also show continuous evolution of amorphous-like denser microstructure with increase in SiO2 content in the films. Hence incorporation of SiO2 in the Gd2O3 matrix, results in a continuous change in oxygen coordination yielding a change in the Gd-O bond length and also results in a continuous increase in amorphousness and a smoother morphology of the samples and, unlike the HfO2-SiO2 system, does not show any maximum for a particular SiO2 concentration.

  19. Solvothermal Synthesis of Gd2O3 : Eu3+ Luminescent Nanowires

    Directory of Open Access Journals (Sweden)

    Guixia Liu

    2010-01-01

    Full Text Available Uniform Gd2O3 : Eu3+ luminescent nanowires were prepared on a large scale by a facile solvothermal method using polyethylene glycol (PEG-2000 as template and ethanol as solvent; the properties and the structure were characterized. X-ray diffraction (XRD patterns and Fourier transform infrared spectrometry (FTIR showed that the precursors are hexagonal phase Gd(OH3 crystals, and the samples calcined at 800C° are cubic phase Gd2O3. Transmission Electron Microscopy (TEM images indicated that the samples are nanowires with a diameter of 30 nm and a length of a few microns. Photoluminescence (PL spectra showed that the ratio of D50→F72 to D50→F71 transition peak of the calcined samples is stronger than that of the precursors, which confirmed that the color purity of the Gd2O3 : Eu3+ is better than that of the precursors. The as-obtained Gd2O3 : Eu3+ luminescent nanowires show a strong red emission corresponding to D50→F72 transition (610 nm of Eu3+ under ultraviolet excitation (250 nm, which have potential application in red-emitting phosphors and field emission display devices.

  20. Molecular beam epitaxy deposition of Gd2O3 thin films on SrTiO3 (100) substrate

    Science.gov (United States)

    Wang, Jinxing; Hao, Jinghua; Zhang, Yangyang; Wei, Hongmei; Mu, Juyi

    2016-06-01

    Gd2O3 thin films are grown on the SrTiO3 (100) substrate by molecular beam epitaxy (MBE) deposition. X-ray diffraction (XRD) analysis, conventional transmission electron microscopy (TEM) and aberration-corrected scanning transmission electron microscopy (STEM) are performed to investigate the microstructure of deposited thin films. It is found that the as-deposited thin film possesses a very uniform thickness of ∼40 nm and is composed of single cubic phase Gd2O3 grains. STEM and TEM observations reveal that Gd2O3 thin film grows epitaxially on the SrTiO3 (100) substrate with (001)Gd2O3//(100)STO and [110]Gd2O3//[001]STO orientations. Furthermore, the Gd atoms are found to diffuse into the SrTiO3 substrate for a depth of one unit cell and substitute for the Sr atoms near the interface.

  1. Antitumor Efficacy of Anti-GD2 IgG1 Is Enhanced by Fc Glyco-Engineering.

    Science.gov (United States)

    Xu, Hong; Guo, Hongfen; Cheung, Irene Y; Cheung, Nai-Kong V

    2016-07-01

    The affinity of therapeutic antibodies for Fcγ receptors (FcγRs) strongly influences their antitumor potency. To generate antibodies with optimal binding and immunologic efficacy, we compared the affinities of different versions of an IgG1 Fc region that had an altered peptide backbone, altered glycans, or both. To produce IgG1 with glycans that lacked α1,6-fucose, we used CHO cells that were deficient in the enzyme UDP-N-acetylglucosamine: α-3-d-mannoside-β-1,2-N-acetylglucosaminyltransferase I (GnT1), encoded by the MGAT1 gene. Mature N-linked glycans require this enzyme, and without it, CHO cells synthesize antibodies carrying only Man5-GlcNAc2, which were more effective in antibody-dependent cell-mediated cytotoxicity (ADCC). Our engineered IgG1, hu3F8-IgG1, is specific for GD2, a neuroendocrine tumor ganglioside. Its peptide mutant is IgG1-DEL (S239D/I332E/A330L), both produced in wild-type CHO cells. When produced in GnT1-deficient CHO cells, we refer to them as IgG1n and IgG1n-DEL, respectively. Affinities for human FcγRs were measured using Biacore T-100 (on CD16 and CD32 polymorphic alleles), their immunologic properties compared for ADCC and complement-mediated cytotoxicity (CMC) in vitro, and pharmacokinetics and antitumor effects were compared in vivo in humanized mice. IgG1n and IgG1n-DEL contained only mannose and acetylglucosamine and had preferential affinity for activating CD16s, over inhibitory CD32B, receptors. In vivo, the antitumor effects of IgG1, IgG1-DEL, and IgG1n-DEL were similar but modest, whereas IgG1n was significantly more effective (P < 0.05). Thus, IgG1n antibodies produced in GnT1-deficient CHO cells may have potential as improved anticancer therapeutics. Cancer Immunol Res; 4(7); 631-8. ©2016 AACR. PMID:27197064

  2. Growth of CaIrO3 and Gd2Ir2O7 by MBE

    Science.gov (United States)

    Nie, Yuefeng; Held, Rainer; Chatterjee, Shouvik; Monkman, Eric; Shai, Daniel; Harter, John; Burganov, Bulat; Adamo, Carolina; Schlom, Darrell; Shen, Kyle

    2012-02-01

    Recently, it was pointed out that the 5d transition metal iridium oxides (iridates) are promising candidates to realize topological insulators, which provide a unique platform in studying the interplay of Coulomb interactions, spin-orbit coupling, and the band topology of solids. We successfully grew epitaxial perovskite CaIrO3 and pyrochlore Gd2Ir2O7 films by reactive molecular-beam epitaxy (MBE). A range of biaxial strains for epitaxial CaIrO3 films was achieved by growing on different substrates. Angle-resolved photoemission spectroscopy (ARPES) will be used to investigate the electronic structure of the epitaxial CaIrO3 and Gd2Ir2O7 films.

  3. Effect of Li+ - dopant on photoluminescence of Gd2O3: Eu3+ nanophosphor

    International Nuclear Information System (INIS)

    Li+ - doped Gd2O3: Eu3+ phosphors have been studied as potential red phosphors for application to field emission displays. The Li+ - doped and undoped Gd2O3: Eu3+ phosphors were synthesized by low temperature solution combustion method. The enhanced luminescence was regarded as the result of the creation of oxygen vacancies due to the Gd3+ sites occupied by Li+ ions, the alteration of the crystal field surrounding the activator Eu3+ ions owing to the incorporation of Li+ ions into interstial sites. The result in a remarkable increase on photoluminescence and the strong emission was observed at 612 nm by a factor of 4.1 in comparison with that of undoped sample. (author)

  4. Synthesis and Characterization of Gd2O3 Hollow Microspheres Using a Template-Directed Method

    OpenAIRE

    Xueliang Jiang; Lu Yu; Chu Yao; Fuqing Zhang; Jiao Zhang; Chenjian Li

    2016-01-01

    Uniform rare-earth gadolinium oxide (Gd2O3) hollow microspheres, as formed through a urea-assisted homogenous precipitation process using carbon spheres as a template and a subsequent heat treatment, were characterized by using X-ray diffraction, Fourier transformed infared spectroscopy, thermogravimetry, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy and Brunauer-Emmett-Tellet surface area measurement. The results indicate that the final prod...

  5. Scintillation properties of RbGd2Br7:Ce advantages and limitations

    International Nuclear Information System (INIS)

    The scintillation properties of RbGd2Br7 crystals, doped with Ce3+ concentrations of 0.02, 0.11, 0.88, 2.05, 4.1, and 9.8%, are studied under X-ray and γ-quanta excitations. For the RbGd2Br7 sample doped with 9.8% Ce, the authors measured a light yield of 56,000 ± 6,000 photons per MeV of absorbed γ-ray energy with a main decay time of 43 ± 1 ns, using a Hamamatsu R1791 photomultiplier (PMT), a 137Cs radioactive source, and a shaping time of 10 micros. A time resolution of 790 ± 10 ps was measured for the RbGd2Br7:9.8% Ce compound, using Baf2 as second scintillator, two XP2020Q PMT's, a 22Na source, and an energy threshold set at E ge 511 keV. With the R1791 PMT, an energy resolution of 4.1% (FWHM over peak position) for the 662-keV full absorption peak has been observed for two crystals of 7 x 4 x 2 mm3 with 4.1 and 9.8% Ce content, respectively. Moreover, the non-proportional responses of three RbGd2Br7:Ce compounds with different concentrations (0.11, 2.05, and 9.8%) were studied revealing an almost-constant light output response from 17.4 keV to 1 MeV. These properties are compared to three other well-known scintillators: NaI:Tl, XsI:Tl, and Lu2SiO5:Ce

  6. Thermal expansion anomaly and spontaneous magnetostriction of Gd2Fe17 compound

    Institute of Scientific and Technical Information of China (English)

    HAO Yanming; LIANG Feifei; ZHANG Xuemin; WANG Fang; WU Yanzhao

    2011-01-01

    Materials with negative thermal expansion have many practical applications.However,these materials are known in only several oxide systems,and when the negative thermal expansion occurs,the contraction is usually small and limited to a narrow temperature range beyond room temperature.For obtaining a compound with negative thermal expansion in broad temperature range,the structural and magnetic properties of Gd2Fe17 compound were investigated by means of X-ray diffraction and magnetization measurements.The Gd2Fe17 compound annealed at 1050 ℃ had a Th2Zn17-type Structure.There existed an anisotropic strong spontaneous magnetostriction and a negative thermal expansion in Gd2Fe17 compound.The average thermal expansion coefficients was α =-7.40×10-6/K in the temperature range of 294-453 K and (α) =-1.80x 10-5/K in 453-534 K,respectively.The spontaneous rnagnetostrictive deformation ωs decreased from 4.34x10-3 to near zero with temperature increasing from 294 to 572 K.The spontaneous linear deformation λc was much larger than λa at the same temperature below about 500 K.

  7. Gd2O3:Eu3+/PPO/POPOP/PS composites for digital imaging radiation detectors

    International Nuclear Information System (INIS)

    Polymer-based scintillator composites have been produced by combining polystyrene (PS) and Gd2O3:Eu3+ scintillator nanoparticles. Polystyrene has been used since it is a flexible and stable binder matrix, resistant to thermal and light deterioration and with suitable optical properties. Gd2O3:Eu3+ has been selected as scintillator material due to its wide band gap, high density and visible light yield. The optical, thermal and electrical characteristics of the composites were studied as a function of filler content, together with their performance as scintillator material. Additionally 1 wt.% of 2,5-diphenyloxazole (PPO) and 0.01 wt.% of 1,4 di[2-(5phenyloxazolyl)]benzene (POPOP) were introduced in the polymer matrix in order to strongly improve light yield, i.e., the measured intensity of the output visible radiation, under X-ray irradiation. Increasing scintillator filler concentration (from 0.25 to 7.5 wt.%) increases scintillator light yield and decreases the optical transparency of the composite. The addition of PPO and POPOP strongly increased the overall transduction performance of the composite due to specific absorption and re-emission processes. It is thus shown that Gd2O3:Eu3+/PPO/POPOP/PS composites with 0.25 wt.% of scintillator content with fluorescence molecules are suitable for the development of innovative large-area X-ray radiation detectors with huge demand from the industries. (orig.)

  8. Preparation and effect of thermal treatment on Gd2O3:SiO2 nanocomposite

    Science.gov (United States)

    Ahlawat, Rachna

    2015-04-01

    Rare earth oxides have been extensively investigated due to their fascinating properties such as enhanced luminescence efficiency, lower lasing threshold, high-performance luminescent devices, drug-carrying vehicle, contrast agent in magnetic resonance imaging (MRI), up-conversion materials, catalysts and time-resolved fluorescence (TRF) labels for biological detection etc. Nanocomposites of silica gadolinium oxide have been successfully synthesized by sol-gel process using hydrochloric acid as a catalyst. Gd(NO3)3ṡ6H2O and tetraethyl orthosilicate (TEOS) were used as precursors to obtain powdered form of gadolinum oxide:silica (Gd2O3:SiO2) composite. The powdered samples having 2.8 mol% Gd2O3 were annealed at 500°C and 900°C temperature for 6 h and characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and transmission electron microscope (TEM). The effect of annealing on the phase evolution of the composite system has been discussed in detail. It was found that the sintering of gadolinium precursor plays a pivotal role to obtain crystalline phase of Gd2O3. Cubic phase of gadolinium oxide was developed for annealed sample at 900°C (6 h) with an average grain size 12 nm.

  9. Electrical characteristics of MOS capacitor using amorphous Gd_2O_3-doped HfO_2 insulator

    Institute of Scientific and Technical Information of China (English)

    季梅; 王磊; 熊玉华; 杜军

    2010-01-01

    This work described the electrical characteristics of a kind of amorphous Gd2O3-doped HfO2 insulator for high-k metal-oxide-semiconductor(MOS) capacitors.Compared with pure HfO2,the doped HfO2 with an optimum concentration of Gd2O3 as MOS gate dielectric exhibited a lower leakage current,thinner effective oxide thickness and less fixed oxide charges density.The result indicated that Gd2O3 doping power of 60 W exhibited the best electrical characteristics,maximum capacitance,lowest leakage current of 9.35079...

  10. Crystallization and dielectric properties of lead-free glass-ceramic composites with Gd_2O_3 addition

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    Lead-free glass-ceramic composites in barium sodium niobate silica system with Gd2O3 addition were synthesized through melt-casting fol-lowed by controlled crystallization technique. Crystallization and dielectric properties of the Gd2O3 adding glass-ceramic composites were investigated. With the increase in the concentration of Gd2O3, the glass transition temperature and the crystallization temperature of the pre-cursor glass shift towards the higher temperature. The crystallization behavior that occurred ...

  11. Experimental phase diagram determination and thermodynamic assessment of the Gd2O3-CoO system

    International Nuclear Information System (INIS)

    New phase diagram data and a thermodynamic assessment of the Gd2O3-CoO system using the CALPHAD approach are presented, giving liquidus data and mutual solid solubilities of Co in Gd2O3 and Gd in CoO. The thermodynamic model parameters for the ternary Gd-Co-perovskite phase and for the mutual solid solubilities of Co in Gd2O3 and Gd in CoO are optimized to reproduce these new experimental data, as well as phase diagram data from literature. The Gd2O3-CoO phase diagram is refined based on the results of experiments using combined differential thermal analysis and thermogravimetry, scanning electron microscopy and X-ray diffraction techniques.

  12. Comparison of photoluminescence properties of Gd2O3 phosphor synthesized by combustion and solid state reaction method

    Directory of Open Access Journals (Sweden)

    Raunak Kumar Tamrakar

    2014-10-01

    Full Text Available In this paper, we presented a comparison of Photoluminescence (PL studies of Gd2O3 phosphor prepared by two synthesis methods, high temperature (1400 °C solid state reaction and low temperature combustion synthesis. Both of these methods synthesized Gd2O3 phosphor successfully. Structural properties of Gd2O3 phosphor were investigated by X-ray diffraction (XRD, Fourier transform infrared spectroscopy (FTIR. Scanning electron microscope (SEM, Energy dispersive X-ray analysis (EDX, and Transmission electron microscopy (TEM. The results obtained for both methods of preparation were compared. The photoluminescence (PL properties of pure Gd2O3 were carried out over the range of 300 nm–650 nm. A PL emission band at UV region in between 318 and 370 nm along with blue, green and red emission was observed at 275 nm excitation.

  13. Phase-Transition and Magnetic Moment of the Gd3+ Ion in the Gd2Fe17 Compound

    Institute of Scientific and Technical Information of China (English)

    HAO Yan-Ming; FU Bin; ZHOU Yan; ZHAO Miao

    2009-01-01

    The structure and magnetic phase transitions of the Gd2Fe17 compound are investigated by using a differential thermal/thermogravimetric analyzer, x-ray diffraction, and magnetization measurements. The result shows that there are two phase structures for the Gd2Fe17 compound: the hexagonal Th2Ni17-type structure at high tem-peratures (above 1243℃), and the rhombohedrai Th2Zn17-type structure, respectively. A method to measure the magnetic moments of the Gd-sublattice and the Fe-sublattice in the Gd2Fe17 compound is presented. The moments of the Gd-sublattice and the Fe-sublattice in the Gd2Fe17 compound from 77 to 500 K are measured in this way with a vibrating sample magnetometer. A detailed discussion is presented.

  14. Image Quality Assessment of a CMOS/Gd2O2S:Pr,Ce,F X-Ray Sensor

    Directory of Open Access Journals (Sweden)

    Christos Michail

    2015-01-01

    Full Text Available The aim of the present study was to examine the image quality performance of a CMOS digital imaging optical sensor coupled to custom made gadolinium oxysulfide powder scintillators, doped with praseodymium, cerium, and fluorine (Gd2O2S:Pr,Ce,F. The screens, with coating thicknesses 35.7 and 71.2 mg/cm2, were prepared in our laboratory from Gd2O2S:Pr,Ce,F powder (Phosphor Technology, Ltd. by sedimentation on silica substrates and were placed in direct contact with the optical sensor. Image quality was determined through single index (information capacity, IC and spatial frequency dependent parameters, by assessing the Modulation Transfer Function (MTF and the Normalized Noise Power Spectrum (NNPS. The MTF was measured using the slanted-edge method. The CMOS sensor/Gd2O2S:Pr,Ce,F screens combinations were irradiated under the RQA-5 (IEC 62220-1 beam quality. The detector response function was linear for the exposure range under investigation. Under the general radiography conditions, both Gd2O2S:Pr,Ce,F screen/CMOS combinations exhibited moderate imaging properties, in terms of IC, with previously published scintillators, such as CsI:Tl, Gd2O2S:Tb, and Gd2O2S:Eu.

  15. Energy transfer and luminescence dynamics in Ca3Gd2(BO3)4:Eu3+

    International Nuclear Information System (INIS)

    Eu3+-doped and -undoped Ca3Gd2(BO3)4 phosphors were synthesized by the high temperature solid-state reaction. The excitation and emission spectra and the decays of the Gd3+ and Eu3+ luminescence in Ca3Gd2(BO3)4:Eu3+ under excitation into the self-trapped excitation (STE) state are investigated in the wavelength region from vacuum ultraviolet to visible. The efficient energy transfer occurs from the host STE state to the emitting state of Eu3+5D0 via two intermediate states: the Gd3+6P7/2 state or the O–Eu charge transfer state. The analyses of decay curves of the Eu3+5D0 emission at 615 nm and the Gd3+6P7/2 emission at 314 nm show much faster energy transfer from Gd3+ to Eu3+ than the energy diffusion among the Gd3+ ions. -- Highlights: • Luminescence dynamics are investigated in Ca3Gd2(BO3)4:Eu3+. • The excited STE state relaxes to the Eu3+5D0 state through the Gd3+6P7/2 state or the O–Eu charge transfer state. • Much faster energy transfer occurs from Gd to Eu than the energy diffusion among the Gd3+ ions. • The feeding of the 5D0 population occurs dominantly from the O–Eu charge transfer state at higher Eu3+ concentration

  16. UV and gamma ray induced thermoluminescence properties of cubic Gd2O3:Er3+ phosphor

    OpenAIRE

    Raunak Kumar Tamrakar; Durga Prasad Bisen; Ishwar Prasad Sahu; Nameeta Brahme

    2014-01-01

    This paper reports the thermoluminescence properties of Er3+ doped gadolinium oxide nanophosphor. The phosphor is prepared by high temperature solid state reaction method. The method is suitable for large scale production. Starting materials used for sample preparation were Gd2O3, Er2O3 (0.5–2.5 mol%) and fixed concentration of boric acid using as a flux. The prepared samples were characterized by X-ray diffraction technique and the particle size calculated by Scherer's formula. The surface m...

  17. Impact of metal electrode on charge transport behavior of metal-Gd2O3 systems

    International Nuclear Information System (INIS)

    In this paper, we have grown an 80 nm thick Gd2O3 thin film by electron beam evaporation on glass substrate and fabricated different metal (Al, Cu, Cr and Au) electrodes on grown sample under same condition. To investigate the charge transport mechanism in these metal-semiconductor systems, the electrical conductivities and current–voltage (I–V) measurements have been measured over temperature range of 250–400 K. We have found that Mott variable range hopping (VRH) is responsible for conduction behavior in all systems for entire temperature range. A strong correlation between transport properties and metal work function has been observed. A space charge model successfully explained the decreasing trend of conductivity with increasing the metal work function. The conductivity decreased from 2.9 × 10−5 to 1.8 × 10−11 S/cm as the metal work function increased from 4 to 5.1 eV for Al to Au metals respectively. The ideality factor also increased from 1.67 to 2.2 with metal work function from Al to Au metal. The observed result can be explained as; high work function metal forms higher depletion layer as compared to metal having low work function, which compensate the empty sites available for hopping and consequently decreased the hopping conductivity. - Graphical abstract: Different metal electrodes (Al, Cu, Cr and Au) were fabricated on 80 nm Gd2O3 thin film by electron beam evaporation and found that Mott VRH is responsible for conduction behavior in all systems for entire temperature range. We also observed a strong correlation between transport properties and metal work function has been observed. - Highlights: • Charge transport mechanism in metal-Gd2O3-metal systems in the temperature range 290–380 K. • Al, Cu, Cr and Au metal electrodes were fabricated on 80 nm Gd2O3 thin film by E.B evaporation. • Mott VRH is responsible for conduction behavior in all systems for entire temperature range. • A strong correlation between transport properties

  18. Critical loading configurations of the IPEN/MB-01 Reactor with UO2GD2O3 burnable poison rods

    International Nuclear Information System (INIS)

    Since 2004, the IPEN and CTMSP jointly has been participating actively to the ICSBEP project conducted by the INEEL. A series of critical experiments with water-moderated square-pitched lattices with low-enriched fuel rods conducted at the IPEN/MB-01 reactor were submitted to the ICSBEP, those evaluations were considered as critical benchmarks. Recently, the CTMSP is conducting research and development the technology to fabricate UO2-Gd2O3 fuel at the Fuel and Material Fabrication Laboratory (LABMAT). The objective driving this development is to fabricate a burnable poison pellets for the Angra I and Angra II nuclear power plants. Once the fabrication process is properly developed, some amount of qualification tests will be required. One of tests needed to be address is related to neutronic absorption efficiency of burnable poison. The UO2-Gd2O3 burnable poison will be fabricated as mixed part of UO2 and Gd2O3 powder. The experimental methodology to evaluate the neutronic absorption efficiency was done performing a set of experimental critical configurations using a few number of UO2-Gd2O3 burnable poison pins. The experiments were performed in two steps, the first evaluation was carried out using only a Gd2O3 rods, the second evaluations was performed using the compound of UO2-Gd2O3 burnable poison rods. This work presents a series of critical configurations obtained at IPEN/MB-01 research reactor using a UO2-Gd2O3 burnable poison rods and compared to the Monte Carlo calculations. (author)

  19. Fabrication and phase transition of Gd2Zr2O7 ceramics immobilized various simulated radionuclides

    International Nuclear Information System (INIS)

    Highlights: • Gd2Zr2O7 ceramics immobilized multi-nuclides were successfully fabricated. • All samples exhibited a single phase structure. • Phase transition happened with enhanced doping content. - Abstract: To investigate the feasibility of Gd2Zr2O7 used for disposal waste of multi-nuclides with multi-valence, simulated trialkyl phosphine oxides (TRPO) waste was chosen to research the fabrication method and phase evolution. A series of (Gd,A)2(Zr,B)2O7 ceramics were successfully fabricated through a solid-state reaction sintering at 1500 °C for 72 h. XRD studies reveal that the compositions containing up to 35 wt.% simulated TRPO waste exhibit a single pyrochlore structure, while the doping content varies from 35 to 65 wt.%, the samples adopt a single defect fluorite structure. In the discussed range, the lattice parameter decreases with the increased doping content, and the rA/rB ratio decreases from 1.43 to 1.27, while the degree order increases in turn. Furthermore, the densification and grain growth in pyrochlore structure are promoted by an enhanced doping content

  20. SmedGD 2.0: The Schmidtea mediterranea genome database

    Science.gov (United States)

    Robb, Sofia M.C.; Gotting, Kirsten; Ross, Eric; Sánchez Alvarado, Alejandro

    2016-01-01

    Planarians have emerged as excellent models for the study of key biological processes such as stem cell function and regulation, axial polarity specification, regeneration, and tissue homeostasis among others. The most widely used organism for these studies is the free-living flatworm Schmidtea mediterranea. In 2007, the Schmidtea mediterranea Genome Database (SmedGD) was first released to provide a much needed resource for the small, but growing planarian community. SmedGD 1.0 has been a depository for genome sequence, a draft assembly, and related experimental data (e.g., RNAi phenotypes, in situ hybridization images, and differential gene expression results). We report here a comprehensive update to SmedGD (SmedGD 2.0) that aims to expand its role as an interactive community resource. The new database includes more recent, and up-to-date transcription data, provides tools that enhance interconnectivity between different genome assemblies and transcriptomes, including next generation assemblies for both the sexual and asexual biotypes of S. mediterranea. SmedGD 2.0 (http://smedgd.stowers.org) not only provides significantly improved gene annotations, but also tools for data sharing, attributes that will help both the planarian and biomedical communities to more efficiently mine the genomics and transcriptomics of S. mediterranea. PMID:26138588

  1. Characterization and luminescent properties of Eu3+ doped Gd2Zr2O7 nanopowders

    International Nuclear Information System (INIS)

    Highlights: • Nanopowders Gd2Zr2O7 doped by europium ions (Eu3+) have been synthesized. • Their luminescence properties have been measured at room temperature. • The temporal evolution of laser induced phenomena are presented using time-resolved technique. • Lifetime analysis for luminescence bands in emission spectra has been done. - Abstract: Nanopowders based on gadolinium zirconium oxide (Gd2Zr2O7) doped by europium ions (Eu3+) were successfully prepared using a flame combustion method. This material is suitable for various optical devices. The structure of prepared materials has been confirmed and characterized using X-ray powder diffraction (XRD), scanning electron microscope (SEM) and photoluminescence (PL) techniques. The luminescence properties of synthesized nanopowders were characterized by emission spectra and luminescence lifetimes by using the streak camera system. PL spectra were obtained at three different excitation wavelengths (Optical Parametric Oscilator (OPO) at 360 nm, laser diode at 365 nm and Ar laser line at 514.5 nm). The strong emission lines at 611 nm and 630 nm corresponding to the 5D0 → 7F2 long lived transition could be used as a new red light source in optical devices

  2. Preparation of highly ordered growth of single-crystalline Gd2O2S:Eu3+ nanostructures

    International Nuclear Information System (INIS)

    Graphical abstract: Fabrication of highly ordered single-crystalline Gd2O2S:Eu3+ nanostructures over a porous anodized aluminum oxide (AAO) template via hydrothermal method is described. Well aligned non-collapsed Gd2O2S:Eu3+ nanostructures are ideal functional components for next generation luminescent devices. Research highlights: → Synthesis of highly ordered Gd2O2S:Eu3+ nanotubes, nanorods and nanoflowers. → Using template-assisted (AAO) hydrothermal method. → Well aligned nanostructures for next generation luminescent devices. → Detailed structural, morphology and the phase composition were studied. -- Abstract: A simple and facile template-assisted hydrothermal route has been demonstrated for the shape-selective preparation of highly ordered single-crystalline Gd2O2S:Eu3+ nanostructures, such as nanotubes, nanorods and nanoflowers. These fabricated nanostructures possess desirable atomic structures, surfaces, morphologies and properties to meet the growing demands and specific requirements of new technologies. The concentration of precursor chemicals, the temperature, the reaction time, and the use of a capping agent are key factors in the morphological control of Gd2O2S:Eu3+ nanostructures. The morphology and the phase composition of the prepared nanostructures were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), energy disperse spectroscopy (EDS) and photoluminescence (PL). We believe this technique will be readily adopted in realizing other forms of various nanostructured materials.

  3. Image Quality Assessment of a CMOS/Gd2O2S:Pr,Ce,F X-ray Sensor

    Science.gov (United States)

    Michail, C. M.; Seferis, I. E.; Sideras, T.; Valais, I. G.; Fountos, G. P.; Bakas, A.; Panayiotakis, G. S.; Kandarakis, I. S.

    2015-09-01

    The aim of the present study was to examine the image quality performance of a CMOS digital imaging optical sensor coupled to custom made gadolinium oxysulfide powder scintillators, doped with praseodymium, cerium and fluorine (Gd2O2S:Pr,Ce,F) screens. The screens, with coating thicknesses 35.7 and 71.2 mg/cm2, were prepared in our laboratory from Gd2O2S:Pr,Ce,F powder (Phosphor Technology, Ltd) by sedimentation on silica substrates and were placed in direct contact with the optical sensor. Image quality was determined through a single index image quality parameter (information capacity). The CMOS sensor/Gd2O2S:Pr,Ce,F screens combinations were irradiated under the RQA-5 (IEC 62220-1) beam quality. The detector response function was linear for the exposure range under investigation. Under the general radiography conditions, both Gd2O2S:Pr,Ce,F screen/CMOS combinations exhibited comparable overall imaging properties, in terms of the information capacity, to previously published scintillators, such as Gd2O2S:Eu.

  4. Combined Effects of Radiation Damage and He Accumulation on Bubble Nucleation in Gd2Ti2O7

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, Caitlin A.; Patel, Maulik K.; Aguiar, Jeffery A.; Zhang, Yanwen; Crespillo, Miguel L.; Wen, Juan; Xue, Haizhou; Wang, Yongqiang; Weber, William J.

    2016-10-01

    Pyrochlores have long been considered as host phases for long-term immobilization of radioactive waste nuclides that would undergo ..alpha..-decay for hundreds of thousands of years. This work utilizes ion-beam irradiations to examine the combined effects of radiation damage and He accumulation on bubble formation in Gd2Ti2O7 over relevant waste-form timescales. Helium bubbles are not observed in pre-damaged Gd2Ti2O7 implanted with 2 x 1016 He/cm2, even after post-implantation irradiations with 7 MeV Au3+ at 300, 500, and 700 K. However, He bubbles with average diameters of 1.5 nm and 2.1 nm are observed in pre-damaged (amorphous) Gd2Ti2O7 and pristine Gd2Ti2O7, respectively, after implantation of 2 x 1017 He/cm2. The critical He concentration for bubble nucleation in Gd2Ti2O7 is estimated to be 6 at.% He.

  5. Lack of survival advantage with autologous stem-cell transplantation in high-risk neuroblastoma consolidated by anti-GD2 immunotherapy and isotretinoin

    Science.gov (United States)

    Kushner, Brian H.; Ostrovnaya, Irina; Cheung, Irene Y.; Kuk, Deborah; Modak, Shakeel; Kramer, Kim; Roberts, Stephen S.; Basu, Ellen M.; Yataghene, Karima; Cheung, Nai-Kong V.

    2016-01-01

    Since 2003, high-risk neuroblastoma (HR-NB) patients at our center received anti-GD2 antibody 3F8/GM-CSF + isotretinoin – but not myeloablative therapy with autologous stem-cell transplantation (ASCT). Post-ASCT patients referred from elsewhere also received 3F8/GM-CSF + isotretinoin. We therefore accrued a study population of two groups treated during the same period and whose consolidative therapy, aside from ASCT, was identical. We analyzed patients enrolled in 1st complete/very good partial remission (CR/VGPR). Their event-free survival (EFS) and overall survival (OS) were calculated from study entry. Large study size allowed robust statistical analyses of key prognosticators including MYCN amplification, minimal residual disease (MRD), FCGR2A polymorphisms, and killer immunoglobulin-like receptor genotypes of natural killer cells. The 170 study patients included 60 enrolled following ASCT and 110 following conventional chemotherapy. The two cohorts had similar clinical and biological features. Five-year rates for ASCT and non-ASCT patients were, respectively: EFS 65% vs. 51% (p = .128), and OS 76% vs. 75% (p = .975). In multivariate analysis, ASCT was not prognostic and only MRD-negativity after two cycles of 3F8/GM-CSF correlated with significantly improved EFS and OS. Although a trend towards better EFS is seen with ASCT, OS is near identical. Cure rates may be similar, as close surveillance detects localized relapse and effective salvage treatments are applied. ASCT may not be needed to improve outcome when anti-GD2 immunotherapy is used for consolidation after dose-intensive conventional chemotherapy. PMID:26623730

  6. Growth and scintillation properties of Ce doped Gd2Si2O7/SiO2 eutectics

    Science.gov (United States)

    Kamada, Kei; Kurosawa, Shunsuke; Murakami, Rikito; Yokota, Yuui; Pejchal, Jan; Ohashi, Yuji; Yoshikawa, Akira

    2015-06-01

    Ce:Gd2Si2O7/SiO2 eutectic was grown by the μ-PD method. The square-shape sample with a side of 5 mm and a length of 15 mm was obtained. Two phases of orthorhombic Gd2Si2O7 and SiO2 was observed. Rod-phase was SiO2 and matrix phase was Gd2Si2O7. Ce3+ 4f5d emission have been observed at 400nm. The sample showed light yield of around 16,000 photons/MeV. Scintillation decay time was 46.3ns(21%) 249ns(79%).

  7. Depth-dependent phase change in Gd2O3 epitaxial layers under ion irradiation

    International Nuclear Information System (INIS)

    Epitaxial Gd2O3 thin layers with the cubic structure were irradiated with 4-MeV Au2+ ions in the 1013–1015 cm−2 fluence range. X-ray diffraction indicates that ion irradiation induces a cubic to monoclinic phase change. Strikingly, although the energy-deposition profile of the Au2+ ions is constant over the layer thickness, this phase transformation is depth-dependent, as revealed by a combined X-ray diffraction and ion channeling analysis. In fact, the transition initiates very close to the surface and propagates inwards, which can be explained by an assisted migration process of irradiation-induced defects. This result is promising for developing a method to control the thickness of the rare-earth oxide crystalline phases

  8. Sensitivity improvement of Cerenkov luminescence endoscope with terbium doped Gd2O2S nanoparticles

    International Nuclear Information System (INIS)

    Our previous study showed a great attenuation for the Cerenkov luminescence endoscope (CLE), resulting in relatively low detection sensitivity of radiotracers. Here, a kind of radioluminescence nanoparticles (RLNPs), terbium doped Gd2O2S was mixed with the radionuclide 68Ga to enhance the intensity of emitted luminescence, which finally improved the detection sensitivity of the CLE by using the radioluminescence imaging technique. With the in vitro and in vivo pseudotumor experiments, we showed that the use of RLNPs mixed with the radionuclide 68Ga enabled superior sensitivity compared with the radionuclide 68Ga only, with 50-fold improvement on detection sensitivity, which guaranteed meeting the demands of the clinical diagnosis of gastrointestinal tract tumors

  9. TEM characterization of UO2-Gd2O3 nuclear fuels synthesized by coprecipitation method

    International Nuclear Information System (INIS)

    We present a micro and nano structural characterization of 4% weight doped Gd2O3-UO2 pellet using Transmission Electron Microscopy (TEM). Agglomerate morphology and crystallite sizes were determined using light/dark field and high resolution (HR-TEM) images. Convergent beam Energy Dispersive Spectroscopy (EDS) and Electron Diffraction (ED) were used to evaluate sample composition and homogeneity, even at the nanometer scale. We obtained an average crystallite size of 90±20 nm. Moreover, from TEM-EDS analyses we determined the presence of Gadolinium in all the analyzed crystallites but with 25% variation among their concentrations. These results show the capability of TEM analysis to characterize a nuclear fuel pellet with burnable poisons nano structure and homogeneity.(author)

  10. Spherical and rod-like Gd2O3:Eu3+ nanophosphors—Structural and luminescent properties

    Indian Academy of Sciences (India)

    N Dhananjaya; H Nagabhushana; B M Nagabhushana; B Rudraswamy; C Shivakumara; R P S Chakradhar

    2012-08-01

    A comparative study of spherical and rod-like nanocrystalline Gd2O3:Eu3+ (Gd1.92Eu0.08O3) red phosphors prepared by solution combustion and hydrothermal methods have been reported. Powder X-ray diffraction (PXRD) results confirm the as-formed product in combustion method showing mixed phase of monoclinic and cubic of Gd2O3:Eu3+. Upon calcinations at 800°C for 3 h, dominant cubic phase was achieved. The as-formed precursor hydrothermal product shows hexagonal Gd(OH)3:Eu3+ phase and it converts to pure cubic phase of Gd2O3:Eu3+ on calcination at 600°C for 3 h. TEM micrographs of hydrothermally prepared cubic Gd2O3:Eu3+ phase shows nanorods with a diameter of 15 nm and length varying from 50 to 150 nm, whereas combustion product shows the particles to be of irregular shape, with different sizes in the range 50–250 nm. Dominant red emission (612 nm) was observed in cubic Gd2O3:Eu3+ which has been assigned to ${}^{5}D_{0} \\rightarrow {}^{7}F_{2}$ transition. However, in hexagonal Gd(OH)3:Eu3+, emission peaks at 614 and 621 nm were observed. The strong red emission of cubic Gd2O3:Eu3+ nanophosphors by hydrothermal method are promising for high performance display materials. The variation in optical energy bandgap (g) was noticed in as-formed and heat treated systems in both the techniques. This is due to more ordered structure in heat treated samples and reduction in structural defects.

  11. Hydrothermal synthesis of Gd2O3:Eu3+ nanophosphors: Effect of surfactant on structural and luminescence properties

    International Nuclear Information System (INIS)

    Highlights: • Gd(OH)3:Eu3+, GdOOH:Eu3+ and Gd2O3:Eu3+ phases were prepared by hydrothermal method. • Phosphors were well characterized by XRD, SEM, TEM, Raman, UV–Vis, FT-IR. • Cubic Gd2O3:Eu3+ show intense red emission, which was highly useful for photonics application. • HDA surfactant plays an important role in conversion of cubic to hexagonal phases. -- Abstract: Various morphologies of Eu3+ activated gadolinium oxide have been prepared by hydrothermal method using hexadecylamine (HDA) as surfactant at different experimental conditions. The powder X-ray diffraction studies reveal as-formed product is hexagonal Gd(OH)3:Eu3+ phase and subsequent heat treatment at 350 and 600 °C transforms to monoclinic GdOOH:Eu3+ and cubic Gd2O3:Eu3+ phases respectively. SEM pictures of without surfactant show irregular shaped rods along with flakes. However, in the presence of HDA surfactant, the particles are converted into rods of various sizes. The temperature dependent morphological evolution of Gd2O3:Eu3+ without and with HDA surfactant is studied. TEM micrographs of Gd(OH)3:Eu3+ sample with HDA confirms smooth nanorods with various diameters in the range 20–100 nm. FTIR studies reveal that HDA surfactant plays an important role in conversion of cubic to hexagonal phases. Among these three phases, cubic phase Gd2O3:Eu3+ (λex = 254 nm) show red emission at 612 nm corresponding to 5D0 → 7F2 and is more efficient host than the monoclinic counterpart. The band gap for hexagonal Gd(OH)3:Eu3+ is more when compared to monoclinic GdOOH:Eu3+ and cubic Gd2O3:Eu3+

  12. Inhomogeneous ferrimagnetic-like behavior in Gd2/3Ca1/3MnO3 single crystals

    OpenAIRE

    Haberkorn, N.; Larrégola, S.; Franco, D.; Nieva, G.

    2008-01-01

    We present a study of the magnetic properties of Gd2/3Ca1/3MnO3 single crystals at low temperatures. We show that this material behave as an inhomogeneous ferrimagnet. In addition to small saturation magnetization at 5 K, we have found history dependent effects in the magnetization and the presence of exchange bias. These features are compatible with microscopic phase separation in the clean Gd2/3Ca1/3MnO3 system studied.

  13. Image Quality Assessment of a CMOS/Gd2O2S:Pr,Ce,F X-Ray Sensor

    OpenAIRE

    Christos Michail

    2015-01-01

    The aim of the present study was to examine the image quality performance of a CMOS digital imaging optical sensor coupled to custom made gadolinium oxysulfide powder scintillators, doped with praseodymium, cerium, and fluorine (Gd2O2S:Pr,Ce,F). The screens, with coating thicknesses 35.7 and 71.2 mg/cm2, were prepared in our laboratory from Gd2O2S:Pr,Ce,F powder (Phosphor Technology, Ltd.) by sedimentation on silica substrates and were placed in direct contact with the optical sensor. Image q...

  14. Investigation of the luminescence properties of Dy3+-doped α-Gd2(MoO4)3 phosphors

    International Nuclear Information System (INIS)

    A series of α-Gd2(MoO4)3 phosphors with various Dy3+ concentrations was synthesized by solid state reaction method. The crystal structure and morphology of the phosphors were characterized by X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). The luminescence properties of Dy3+ in α-Gd2(MoO4)3 were systematically studied. The electric dipole-dipole interaction between Dy3+ ions was identified as the main mechanism for luminescence quenching, according to the analysis of concentration quenching and the fluorescent dynamics. The chromatic nature of the phosphors was also analyzed in detail.

  15. Structure properties and sintering densification of Gd2Zr2O7 nanoparticles prepared via different acid combustion methods

    Institute of Scientific and Technical Information of China (English)

    马雷; 马伟民; 孙旭东; 刘佳男; 纪连永; 宋晗

    2015-01-01

    Gadolinium zirconate (Gd2Zr2O7) nanocrystals were prepared via two different combustion methods:citric acid combus-tion (CAC) and stearic acid combustion (SAC). The effects of the different preparation methods on the phase composition, micro-topography, and sintering densification of the resulting Gd2Zr2O7 nanopowders were investigated by thermal-gravimetric and differ-ential thermal analysis (TG-DTA), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and transmission elec-tron microscopy (TEM) techniques. The results indicated that both methods could produce Gd2Zr2O7 nanopowders with an excellent defective fluorite structure. The reaction time was reduced by the SAC method, compared with the CAC method. The nanopowders synthesized by the two methods were different in grain size distribution. The resulting nanoparticle diameter was about 50 nm for CAC and 10 nm for SAC. After vacuum sintering, the sintered bodies also had a different relative density of about 93%and 98%, respectively. Thus the preparation of Gd2Zr2O7 nanopowders by SAC was the first choice to achieve the desired sintering densifi-cation.

  16. Citrate mediated synthesis and tuning of luminescence in Eu3+ incorporated Gd2O3 nanophosphors

    Science.gov (United States)

    Abhilash Kumar, R. G.; Gopchandran, K. G.

    2015-02-01

    Gd1.9Eu0.1O3 nanophosphors were prepared successfully by a large-scale facile solution based citrate-metal complex controlled combustion method and was systematically studied by varying the citric acid to metal cation ratio. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), photoluminescence (PL) measurements and radiative properties were done to evaluate the crystal structure, phase formation, phase composition, surface morphology, radiative and luminescent properties of the prepared nanophosphors. Photoluminescent emission intensity of the samples can be correlated with the amount of citric acid, improved crystallinity, uniform morphology, particle size, reduced defects, and proper diffusion of Eu3+ in to the crystal structure of Gd2O3. Higher asymmetricity results in intense red emission (612 nm) due to 5D0-7F2 forced electric dipole transition and found that photoluminescence intensity is highest for the sample prepared with citric acid to metal cation ratio of 2:1. The existence of strong red emission from Gd1.9Eu0.1O3 nanophosphor corresponding to 5D0-7F2 transition (612 nm) of Eu3+ under UV light excitation make it a promising candidate for applications in bio assays, magnetic resonance imaging, deep uv LED's, solid state lighting, fluorescent lamps and flat panel displays.

  17. Properties of Gd2O3 nanoparticles studied by hyperfine interactions and magnetization measurements

    Science.gov (United States)

    Correa, E. L.; Bosch-Santos, B.; Cavalcante, F. H. M.; Correa, B. S.; Freitas, R. S.; Carbonari, A. W.; Potiens, M. P. A.

    2016-05-01

    The magnetic behavior of Gd2O3 nanoparticles, produced by thermal decomposition method and subsequently annealed at different temperatures, was investigated by magnetization measurements and, at an atomic level, by perturbed γ - γ angular correlation (PAC) spectroscopy measuring hyperfine interactions at 111In(111Cd) probe nuclei. Nanoparticle structure, size and shape were characterized by X-ray diffraction (XRD) and Transmission Electron Microscopy (TEM). Magnetization measurements were carried out to characterize the paramagnetic behavior of the samples. XRD results show that all samples crystallize in the cubic-C form of the bixbyite structure with space group Ia3. TEM images showed that particles annealed at 873 K present particles with highly homogeneous sizes in the range from 5 nm to 10 nm and those annealed at 1273 K show particles with quite different sizes from 5 nm to 100 nm, with a wide size distribution. PAC and magnetization results show that samples annealed at 873 and 1273 K are paramagnetic. Magnetization measurements show no indication of blocking temperatures for all samples down to 2 K and the presence of antiferromagnetic correlations.

  18. Blue and green emitting Ce3+ and Tb3+ codoped Gd2O3 nanophosphors

    International Nuclear Information System (INIS)

    Tb3+ doped Gd2O3 nanoparticles of 4-10 nm in size were synthesized from nitrate precursors by urea hydrolysis method in ethylene glycol medium at low temperature of 140 ℃. Characteristic Tb3+ ion green emission corresponding to 5D4 ’! 7FJ was observed to be very strong, which further increases with heat treatment temperature. Characteristic blue color emission of Ce3+ ion transitions for 5d’! 2F7/2 and 2F5/2 (at 422 nm and 485 nm respectively) was found to be very strong in as-synthesized Ce0.06Tb0.14Gd0.8O3 nanoparticles. However, its luminescence intensity decreases with increase in heating temperature or increase in the particle size/crystallinity, whereas there was a weak emission peak of Tb3+ ion at 545 nm. The polycrystalline nature of as-prepared sample change to highly crystalline state when heated at elevated temperature (900 ℃). (author)

  19. Irradiation damage in Gd2Ti2O7 single crystals: Ballistic versus ionization processes

    International Nuclear Information System (INIS)

    The structural transformations induced in Gd2Ti2O7 single crystals irradiated at high energies (870-MeV Xe), where ionization processes (electronic stopping) dominate, and at low energies (4-MeV Au), where ballistic processes (nuclear stopping) dominate, have been studied via the combination of Rutherford backscattering spectrometry and channeling (RBS/C), Raman spectroscopy, and transmission electron microscopy (TEM) experiments. At high energy, amorphization occurs directly in individual ion tracks from the extreme electronic-energy deposition, and full amorphization results from the overlapping of these tracks as described by a direct impact model. The track diameters lie in the range 6-9 nm. At low energy, amorphization occurs via indirect processes, driven by ballistic nuclear energy deposition from the ions, that is accounted for in the framework of both direct-impact/defect-stimulated and multi-step damage accumulation models. The ion fluence for total amorphization of the irradiated layer is much higher at low energy (0.5 ion nm-2) than at high energy (0.05 ion nm-2), consistent with the nuclear stopping at low energy (5.2 keV/nm) compared to the electronic stopping at high energy (29 keV/nm).

  20. Temperature dependence of Er3+ ionoluminescence and photoluminescence in Gd2O3:Bi nanopowder

    International Nuclear Information System (INIS)

    Ionoluminescence (IL) and photoluminescence (PL) of trivalent erbium ions (Er3+) in Gd2O3 nanopowder host activated with Bi3+ ions has been studied in order to establish the link between changes in luminescent spectra and temperature of the sample material. IL measurements have been performed with H2+ 100 keV ion beam bombarding the target material for a few seconds, while PL spectra have been collected for temperatures ranging from 20 °C to 700 °C. The PL data was used as a reference in determining the temperature corresponding to IL spectra. The collected data enabled the definition of empirical formula based on the Boltzmann distribution, which allows the temperature to be determined with a maximum sensitivity of 9.7 × 10−3 °C−1. The analysis of the Er3+ energy level structure in terms of tendency of the system to stay in thermal equilibrium, explained different behaviors of the line intensities. This work led to the conclusion that temperature changes during ion excitation can be easily defined with separately collected PL spectra. The final result, which is empirical formula describing dependence of fluorescence intensity ratio on temperature, raises the idea of an application of method in temperature control, during processes like ion implantation and some nuclear applications

  1. Temperature dependence of Er3+ ionoluminescence and photoluminescence in Gd2O3:Bi nanopowder

    CERN Document Server

    Boruc, Zuzanna; Fetliński, Bartosz; Kaczkan, Marcin; Malinowski, Michał

    2016-01-01

    Ionoluminescence (IL) and photoluminescence (PL) of trivalent erbium ions (Er3+) in Gd2O3 nanopowder host activated with Bi3+ ions has been studied in order to establish the link between changes in luminescent spectra and temperature of the sample material. IL measurements have been performed with H2+ 100 keV ion beam bombarding the target material for a few seconds, while PL spectra have been collected for temperatures ranging from 20 to 700{\\deg}C. The PL data was used as a reference in determining the temperature corresponding to IL spectra. The collected data enabled the definition of empirical formula based on the Boltzmann distribution, which allows the temperature to be determined with a maximum sensitivity of 9.7 x 10-3 {\\deg}C-1. The analysis of the Er3+ energy level structure in terms of tendency of the system to stay in thermal equilibrium, explained different behaviors of the lines intensities. This work led to the conclusion that temperature changes during ion excitation can be easily defined wit...

  2. Crystal structure of the ternary silicide Gd2Re3Si5

    Directory of Open Access Journals (Sweden)

    Vitaliia Fedyna

    2014-12-01

    Full Text Available A single crystal of the title compound, the ternary silicide digadolinium trirhenium pentasilicide, Gd2Re3Si5, was isolated from an alloy of nominal composition Gd20Re30Si50 synthesized by arc melting and investigated by X-ray single-crystal diffraction. Its crystal structure belongs to the U2Mn3Si5 structure type. All atoms in the asymmetric lie on special positions. The Gd site has site symmetry m..; the two Mn atoms have site symmetries m.. and 2.22; the three Si atoms have site symmetries m.., ..2 and 4.. . The coordination polyhedra of the Gd atoms have 21 vertices, while those of the Re atoms are cubooctahedra and 13-vertex polyhedra. The Si atoms are arranged as tricapped trigonal prisms, bicapped square antiprisms, or 11-vertex polyhedra. The crystal structure of the title compound is also related to the structure types CaBe2Ge2 and W5Si3. It can be represented as a stacking of Gd-centred polyhedra of composition [GdSi9]. The Re atoms form infinite chains with an Re—Re distance of 2.78163 (5 Å and isolated squares with an Re—Re distance of 2.9683 (6 Å.

  3. Europium-doped Gd2O3 nanotubes cause the necrosis of primary mouse bone marrow stromal cells through lysosome and mitochondrion damage.

    Science.gov (United States)

    Jin, Yi; Chen, Shizhu; Duan, Jianlei; Jia, Guang; Zhang, Jinchao

    2015-05-01

    With the wide applications of europium-doped Gd2O3 nanoparticles (Gd2O3:Eu(3+) NPs) in biomedical fields, it will inevitably increase the chance of human exposure. It was reported that Gd2O3:Eu(3+) NPs could accumulate in bone. However, there have been few reports about the potential effect of Gd2O3:Eu(3+) NPs on bone marrow stromal cells (BMSCs). In this study, the Gd2O3:Eu(3+) nanotubes were prepared and characterized by powder X-ray diffraction (XRD), photoluminescence (PL) excitation and emission spectra, scanning electron microscope (SEM), and transmission electron microscopy (TEM). The cytotoxicity of Gd2O3:Eu(3+) nanotubes on BMSCs and the associated mechanisms were further studied. The results indicated that they could be uptaken into BMSCs by an energy-dependent and macropinocytosis-mediated endocytosis process, and primarily localized in lysosome. Gd2O3:Eu(3+) nanotubes effectively inhibited the viability of BMSCs in concentration and time-dependent manners. A significant increase in the percentage of late apoptotic/necrotic cells, lactate dehydrogenase (LDH) leakage and the number of PI-stained cells was found after BMSCs were treated by 10, 20, and 40μg/mL of Gd2O3:Eu(3+) nanotubes for 12h. No obvious DNA ladders were detected, but a dispersed band was observed. The above results revealed that Gd2O3:Eu(3+) nanotubes could trigger cell death by necrosis instead of apoptosis. Two mechanisms were involved in Gd2O3:Eu(3+) nanotube-induced BMSCs necrosis: lysosomal rupture and release of cathepsins B; and the overproduction of reactive oxygen species (ROS) injury to the mitochondria and DNA. The study provides novel evidence to elucidate the toxicity mechanisms and may be beneficial to more rational applications of these nanomaterials in the future. PMID:25725393

  4. Multicolor photoluminescence and energy transfer properties of dysprosium and europium-doped Gd2O3 phosphors

    International Nuclear Information System (INIS)

    In this study, a series of Gd2O3: Ln3+ (Ln = Dy, Eu) submicrospheres were successfully prepared by a hydrothermal method and a subsequent higher temperature pyrolysis. X-ray diffraction (XRD), Fourier transform infrared (FT-IR), field emission scanning electron microscope (FESEM), energy-dispersive X-ray spectrometer (EDS), photoluminescence (PL) spectra and vibrating sample magnetometer (VSM) were utilized to characterize the as-prepared samples. The precursor sample thoroughly decomposed into Gd2O3 submicrospheres with a diameter of about 550 nm after calcination. Under UV excitation, the samples exhibit multicolor emissions including yellow-green, yellow, red as well as white, moreover, the Dy3+ ions acted as donors can transfer the energy to Eu3+ served as acceptors in Gd2O3: Dy3+, Eu3+ system. The interaction between Dy3+ ions and Eu3+ ions is verified to be phonon-assisted electric quadrupole–quadrupole interaction. Multicolor luminescence including white light emission can be obtained through varying the content of Eu3+ or adopting different excitation wavelengths in Dy3+ and Eu3+ co-doped Gd2O3 system. The energy transfer efficiency reaches 88.2% when the doped concentration of Eu3+ is 0.035. The CIE chromaticity diagram directly reveals the variability of the hue of the as-prepared samples. Besides, the as-prepared samples exhibit paramagnetic properties at room temperature. This type of color-tunable luminescence phosphors has promising applications in the fields of photoelectronic devices and biomedical science. - Graphical abstract: Tunable multicolor emissions and energy transfer properties of lanthanides (Ln3+, Ln3+ = Dy3+, Eu3+) doped cubic Gd2O3 submicrospheres prepared by hydrothermal method and a subsequent calcination. - Highlights: • The as-prepared samples can exhibit multicolor emissions. • Dy3+ transfer energy to Eu3+ in Dy3+ and Eu3+ co-doped Gd2O3. • The as-prepared phosphor has promising applications in the fields of

  5. Spectroscopy and photoluminescence of Tm3+:β′-Gd2(MoO4)3 crystal

    International Nuclear Information System (INIS)

    The polarized absorption and photoluminescence were investigated in a Tm3+-doped β′-Gd2(MoO4)3 single crystal. The spectroscopic parameters were calculated based on the Judd–Ofelt theory. Fluorescence emissions and decay curves were measured under different excitations. Results have indicated that the Tm3+:β′-Gd2(MoO4)3 crystal has good application prospects both in blue phosphor for white LED and in eye-safety lasing around 1.9 μm. -- Highlights: ► Spectroscopy and photoluminescence of Tm3+:GM crystal are investigated. ► The spectroscopic parameters are calculated based on the J–O theory. ► The Tm3+:GM crystal has very good fluorescence properties in the blue and 1.9 μm region. ► Results are useful for exploiting phosphor of white LED and eye-safety high performance laser

  6. Eu(3+) doped gadolinium oxysulfide (Gd(2)O(2)S) nanostructures-synthesis and optical and electronic properties.

    Science.gov (United States)

    Thirumalai, J; Chandramohan, R; Divakar, R; Mohandas, E; Sekar, M; Parameswaran, P

    2008-10-01

    One-dimensional Eu(3+) doped gadolinium oxysulfide (Gd(2)O(2)S:Eu(3+)) nanotubes/nanorods have been synthesized via precursors of Gd(OH)(3) nanostructures using a hydrothermal technique. The blue-shifts in the optical spectra for the Gd(2)O(2)S:Eu(3+) system corresponding to the fundamental absorption and Eu(3+)-X(2-) ligand (X =  O/S) charge transfer bands (CTBs) are significant (∼0.22-0.36 eV) with respect to the bulk counterpart. The nanotubes are good candidates for investigating the size-induced electrical and optical properties of functional oxysulfides. In order to identify the origin and nature of the electronic transitions observed in the visible region, optical and photo-induced impedance measurements have been extended to the nanotubes in this report. PMID:21832604

  7. Tunable properties of spin waves in magnetoelastic {NiFe}/{{Gd}}_{2}{({{MoO}}_{4})}_{3} heterostructure

    Science.gov (United States)

    Graczyk, Piotr; Trzaskowska, Aleksandra; Załȩski, Karol; Mróz, Bogusław

    2016-07-01

    Full ferroelastic and simultaneously ferroelectric materials are interesting candidates for applications in devices based on multiferroic heterostructures. They should allow for non-volatile and low-power writing of data bits in magnetoelectric random access memories. Moreover, ferroelasticity, in contrast to piezoelectric material, make magnetic information in ferromagnetic film resistant to external fields. As an example for such a system, we have studied the magnetoelastic interaction between a thin ferromagnetic layer of {{Ni}}85{{Fe}}15 with a full ferroelastic–ferroelectric gadolinium molybdate {{Gd}}2{({{MoO}}4)}3 crystal. We have investigated the influence of {{Gd}}2{({{MoO}}4)}3 spontaneous strain onto magnetic properties of thin ferromagnetic film. Particularly, we have shown by Brillouin spectroscopy, that it is possible to modulate surface spin wave frequency of {{Ni}}85{{Fe}}15 by spontaneous strain of gadolinium molybdate substrate.

  8. High-temperature scintillation properties of orthorhombic Gd2Si2O7 aiming at well logging

    Science.gov (United States)

    Tsubota, Youichi; Kaneko, Junichi H.; Higuchi, Mikio; Nishiyama, Shusuke; Ishibashi, Hiroyuki

    2015-06-01

    Scintillation and luminescence properties of orthorhombic Gd2Si2O7:Ce (GPS:Ce) single-crystal scintillators were investigated for temperatures ranging from room temperature (RT) to 573 K. Orthorhombic GPS crystals were grown by using a top-seeded solution growth (TSSG) method. The scintillation light yield of the orthorhombic GPS at RT was ∼2.9 times higher than that of Gd2SiO5:Ce (GSO). The light yield values of the orthorhombic GPS (Ce = 2.5%) were almost unchanged for temperatures ranging from RT to 523 K, and at 523 K, were higher than twice the light yield of GSO at RT. These GPS scintillators are expected to contribute to oil exploration at greater depths.

  9. Raman and FTIR spectra of CeO2 and Gd2O3 in iron phosphate glasses

    International Nuclear Information System (INIS)

    Highlights: • The structure of the studied samples has been investigated by Raman and FTIR spectroscopy. • The structure for the all samples has similar features. • The structure consists of predominantly Q1 with a fraction of Q0 and Q2 units. • The Ce and Gd enters in the structure of studied glasses as a network modifier. - Abstract: In the present work, multicomponent oxide samples of composition x(CeO2 + Gd2O3)–(40 − x)Fe2O3–60P2O5 (0 ⩽ x ⩽ 8 mol%) were produced by conventional melting method. The samples were investigated to examine the effect of the CeO2 and Gd2O3 composition on the structure of the iron phosphate glasses system. The X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM) for the x ⩽ 6 mol% samples show all the samples formed homogeneous glass, but for the x = 8 mol% samples show the presence of randomly distributed crystalline phase embedded in an amorphous matrix. The x(CeO2 + Gd2O3)–(40 − x)Fe2O3–60P2O5 glass containing 8 mol% CeO2 and Gd2O3 partially crystallized during annealing and Ce/Gd-rich were identified by EDS in the crystalline phase. The structure of the studied samples has been investigated using Raman and Fourier transform infrared spectroscopy (FTIR). The Raman and FTIR spectra for the samples have analogous spectral features. The Raman and FTIR spectra suggest that the structure is mainly constituted by the pyrophosphate glass based structure, with a part proportion of metaphosphate and orthophosphate structure. Raman and FTIR spectra allowed us to identify the structural units which appear in the structural network of these phosphate glasses and also the network modifier role of cerium and gadolinium ions

  10. Properties of Gd2O3:Eu3+, Tb3+ nanopowders obtained by sol-gel process

    International Nuclear Information System (INIS)

    A significant practical application for nanostructured materials is X-ray medical imagery, because it is necessary to use dense materials in order to enable absorption of high energy photons. An important requirement of these materials is UV-vis range emission produced by X-ray excitation, which can be influenced by the particle size. Europium doped gadolinium oxide is a well known red phosphor. Moreover, nanophosphors of Gd2O3 codoped with Tb3+, Eu3+ increase their light yield by energy transfer between Tb3+ and Eu3+. In this study, Gd2O3 nanopowders codoped with Eu3+ and Tb3+ (2.5 at.% Eu3+, and 0.005 and 0.01 at.% Tb3+) were obtained via a sol-gel process using gadolinium pentanedionate as precursor and europium and terbium nitrates as doping sources. In this paper, we report the influence of annealing temperature on the structure, morphology and luminescent properties of Gd2O3:Eu3+, Tb3+ by means of TGA, XRD, TEM and X-ray emission measurements.

  11. A case for oxygen deficiency in Gd2Ti2−xZrxO7 pyrochlore-type oxides

    International Nuclear Information System (INIS)

    Highlights: •Gd2Ti2−xZrxO7 pyrochlore-type oxides were studied by XANES. •The materials were observed to be slightly oxygen deficient. •The number of oxygen defects present increases with greater Zr incorporation. •The oxygen defects are charge balanced by the reduction of some Ti4+ to Ti3+. -- Abstract: Pyrochlore-type oxides having the formula Gd2Ti2−xZrxO7 have been studied in the past as potential candidates for the sequestration of nuclear waste elements owing to their chemical robustness and increased resistance to radiation induced damage with greater Zr incorporation. To be used for nuclear waste sequestration applications, all aspects of these materials need to be understood. This is especially the case for the stoichiometry of the materials and the effect of crystal defects. X-ray absorption near-edge spectroscopy (XANES) has been used here to study the local chemical environment of the metal atoms depending on composition. Analysis of Ti K-edge XANES spectra has shown that Gd2Ti2−xZrxO7 (0 ⩽ x < 2) can be slightly O-deficient, and that the level of O-deficiency increases with greater Zr incorporation

  12. Exploring the interface structure of TaN/Gd2O5/HfO2 gate stacks

    International Nuclear Information System (INIS)

    The recent introduction of high dielectric constant (high-k) oxides such as HfO2 as replacement materials for the SiO2 gate dielectric has accelerated research activity in high-k materials for transistor-based devices. In this study, a Gd2O5/HfO2 stacked gate dielectric was used to fabricate TaN/ Gd2O5/HfO2 /SiO2/Si thin films and MOS capacitors. The effects of annealing condition on the structure and morphological properties of the proposed films were investigated via transmission electron microscopy (TEM). As shown in earlier works, DFT calculations in conjunction with the electrical and physical characterization of the gate stacks demonstrated the importance of controlling the distribution of both oxygen and nitrogen atoms directly at the TiN/HfO2 interface. With the addition of the Gd2O5 -layer, the oxygen concentration depth profile was derived both by means of electron energy loss spectroscopy (EELS) and atom probe tomography (APT). Structural investigation by means of high resolution transmission electron microscopy (HR-TEM) concluded the detailed study of the metal/dielectric interface.

  13. Synthesis of Gd2O3:Ho3+/Yb3+ upconversion nanoparticles for latent fingermark detection on difficult surfaces

    Science.gov (United States)

    Kumar, A.; Tiwari, S. P.; Singh, A. K.; Kumar, K.

    2016-07-01

    Infrared to visible upconversion fluorescent nanoparticles of Gd2O3 codoped with Ho3+/Yb3+ ions are synthesized via thermal decomposition process. The X-ray diffraction analysis of as-synthesized nanoparticles and annealed sample at 1000 °C has shown body-centered cubic phase of Gd2O3. The synthesized phosphor has shown intense green emission upon 980-nm excitation. High-contrast latent fingermarks on some difficult semi-porous and non-porous surfaces under 980-nm diode laser excitation were developed through powder dusting and colloidal solution spraying techniques and the results are compared with the commercial green luminescent fingermark powder. The latent fingermarks were developed on transparent (biological glass slides), single-color (aluminum foil) and multicolor (plywood, plastic bottle and book cover page) background surfaces. The present study depicts that the upconversion-based latent fingermarks detection using Gd2O3:Ho3+/Yb3+ phosphor material is suitable over the other conventional powders and has potential for practical applications in forensic science.

  14. A simple approach for the synthesis of bifunctional Fe3O4-Gd2O3:Eu3+ core–shell nanocomposites

    International Nuclear Information System (INIS)

    Graphical abstract: The TEM images reveal that Fe3O4-Gd2O3:Eu3+ nanoparticles have a particle size ranging from 175 nm to 300 nm and keep the spherical morphology, core–shell structures, non-aggregation and rough surface. The results revealed that the Gd2O3:Eu3+ phosphor layer uniformly deposited on Fe3O4 nanoparticles and thicknesses of Gd2O3:Eu3+ are 20–30 nm. The selected-area electron diffraction (SAED) reveals the polycrystalline feature of the as-prepared product. Highlights: ► Bifunctional magnetic-luminescent Fe3O4-Gd2O3:Eu3+ nanoparticles with core–shell structures have been successfully fabricated by a facile, green, and efficient hydrothermal method. ► Fe3O4-Gd2O3:Eu3+ composites have robust magnetic responsive properties and strong luminescent properties. ► Fe3O4-Gd2O3:Eu3+ nanoparticles have great potential applications in drug targeting, bioseparation and diagnostic analysis. - Abstract: Bifunctional magnetic-luminescent Fe3O4-Gd2O3:Eu3+ nanoparticles with core–shell structures have been successfully fabricated using a simple, green, and efficient hydrothermal method. These materials were characterized by means of X-ray diffraction (XRD), transmission electron microscopy (TEM), photoluminescence (PL) spectra, and a superconducting quantum interference device (SQUID) magnetometer. The results showed that the spinel of the Fe3O4 cores was uniformly coated with Gd2O3:Eu3+ layers. The inner Fe3O4 cores and the outer Gd2O3:Eu3+ layers yielded composites that combine magnetic-responsive and luminescent properties, thus, nanoparticles of the composite may find potential applications in drug targeting, bioseparation, and diagnostic analysis.

  15. X-ray photoelectron spectroscopy analysis for undegraded and degraded Gd2O2S:Tb3+ phosphor thin films

    International Nuclear Information System (INIS)

    This paper presents the X-ray Photoelectron Spectroscopy (XPS) analysis for the undegraded and degraded Gd2O2S:Tb3+ thin film phosphor. The thin films were grown with the pulsed laser deposition (PLD) technique. XPS measurements were done on Gd2O2S:Tb3+ phosphor thin films before and after electron degradation. The XPS technique has proven the presence of Gd2O3 on the degraded and undegraded thin film spots. The presence of the SO2 bonding was also detected after degradation. This clearly indicates that surface reactions did occur during prolonged electron bombardment in an oxygen atmosphere.

  16. Heat capacity measurements on YbGd2–Zr2O7 ( = 0, 1, 2) ceramics by differential scanning calorimetry

    Indian Academy of Sciences (India)

    Zhan-Guo Liu; Jia-Hu Ouyang; Yu Zhou

    2009-12-01

    YbGd2–Zr2O7 ( = 0, 1, 2) ceramics were pressureless-sintered using ceramic powders acquired by chemical-coprecipitation and calcination methods. Heat capacities of YbGd2–Zr2O7 were measured with a heat flux-type differential scanning calorimetry in the temperature range of 298–1200 K. At 298 K, the heat capacities of Gd2Zr2O7, YbGdZr2O7 and Yb2Zr2O7 were 214, 221 and 230 J.K-1 mol-1, respectively.

  17. UV and gamma ray induced thermoluminescence properties of cubic Gd2O3:Er3+ phosphor

    Directory of Open Access Journals (Sweden)

    Raunak Kumar Tamrakar

    2014-10-01

    Full Text Available This paper reports the thermoluminescence properties of Er3+ doped gadolinium oxide nanophosphor. The phosphor is prepared by high temperature solid state reaction method. The method is suitable for large scale production. Starting materials used for sample preparation were Gd2O3, Er2O3 (0.5–2.5 mol% and fixed concentration of boric acid using as a flux. The prepared samples were characterized by X-ray diffraction technique and the particle size calculated by Scherer's formula. The surface morphology of prepared phosphor is determined by scanning electron microscopic (SEM technique. Functional group analysis was done by Fourier transform infra-red spectroscopy (FTIR analysis. The elemental analysis of prepared sample was determined by energy dispersive X-ray analysis (EDX and the exact particle size of prepared phosphor for the different concentration of dopant (Er3+ was evaluated by transmission electron microscopy (TEM technique. The prepared phosphors for different concentration of Er3+ were examined by thermoluminescence (TL glow curve for UV and gamma irradiation. The UV 254 nm source was used for UV irradiation and Co60 source was used for gamma irradiation. The samples show well resolved broad peak covered the temperature range 50–250 °C and the peak temperature found at 126 °C for UV irradiation and higher temperature peak at 214 °C for gamma irradiation. The effect of heating rate on TL studies was presented for optimized sample. Here UV irradiated sample shows the formation of shallow trap (surface trapping and the gamma irradiated sample shows the formation of deep trapping. The estimation of trap formation was evaluated by knowledge of trapping parameters. The trapping parameters such as activation energy, order of kinetics and frequency factor were calculated by peak shape method. Here most of the peak shows second order of kinetics. The effect of gamma and UV exposure on TL studies was also examined and it shows linear

  18. Synthesis of gadolinium carbonate-conjugated-poly(ethylene)glycol (Gd2(CO3)3@PEG) particles via a modified solvothermal method

    International Nuclear Information System (INIS)

    PEGylated gadolinium carbonate ((Gd2(CO3)3)@PEG) powder was successfully synthesized by a modified solvothermal method. The synthesized products were characterized by means of X-ray diffraction (XRD), Fourier Transform Infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and Energy Dispersive X-ray Spectroscopy (EDS). A systematic change in the chemical surface composition, crystallinity and size properties of the Gd2(CO3)3@PEG particles was observed by increasing the reaction time at 5 hours, 7 hours, and 8 hours. The corresponding XRD patterns showed that the Gd2(CO3)3 particles had hexagonal symmetry (JCPDS No. 37-0559) with a crystallite size of 3.5, 2.9, and 4.6 nm. FTIR spectra showed that the Gd2(CO3)3)@PEG particles were formed with the PEG as carbonyl and hydroxyl group attached to the surface. SEM analysis showed that the Gd2(CO3)3)@PEG particles had a flake-like morphology of homogeneous sized particles and agglomerates. EDS analysis confirmed the presence of constituent Gd2(CO3)3 elements

  19. Yolk-shell structured Gd2O3:Eu(3+) phosphor prepared by spray pyrolysis: the effect of preparation conditions on microstructure and luminescence properties.

    Science.gov (United States)

    Cho, Jung Sang; Jung, Kyeong Youl; Kang, Yun Chan

    2015-01-14

    Gd2O3:Eu(3+) yolk-shell phosphor powders with high photoluminescence intensity were prepared by spray pyrolysis. Preparation temperature and spray solution concentration were varied to find the optimum process conditions for preparation of Gd2O3:Eu(3+) with yolk-shell structure. The formation mechanism of yolk-shell Gd2O3:Eu(3+) was systematically investigated by observing the microstructures of particles produced under various preparation conditions. The morphological structure of Gd2O3:Eu(3+) powders was clearly dependent on reactor temperature and on the precursor solution concentration. Eventually, pure yolk-shell structured Gd2O3:Eu(3+) powders were obtained for a reaction temperature of 1000 °C and concentration of the spray solution below 0.2 M. Also, the yolk-shell structure formed showed high thermal stability, making it possible to maintain the original spherical yolk-shell structure through calcination at high temperatures. As a result, highly crystalline Gd2O3:Eu(3+) phosphor powders having yolk-shell structure and an agglomeration-free spherical shape were successfully synthesized by spray pyrolysis. These phosphor powders were shown to have good photoluminescence characteristics. PMID:25424414

  20. Bubble Formation and Lattice Parameter Changes Resulting from He Irradiation of Defect-Fluorite Gd2Zr2O7

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, Caitlin A.; Patel, Maulik K.; Aguiar, Jeffery A.; Zhang, Yanwen; Crespillo, Miguel L.; Wen, Juan; Xue, Haizhou; Wang, Yongqiang; Weber, William J.

    2016-08-15

    Pyrochlores have long been considered as potential candidates for advanced ceramic waste-forms for the immobilization of radioactive waste nuclides. This work provides evidence that Gd2Zr2O7, often considered the most radiation tolerant pyrochlore, could be susceptible to radiation damage in the form of bubble nucleation at the highest He doses expected over geological time. Ion irradiations were utilized to experimentally simulate the radiation damage and He accumulation produced by ..alpha..-decay. Samples were pre-damaged using 7 MeV Au3+ to induce the pyrochlore to defect-fluorite phase transformation, which would occur due to ..alpha..-recoil damage within several hundred years of storage in a Gd2Zr2O7 waste-form. These samples were then implanted to various He concentrations in order to study the long-term effects of He accumulation. Helium bubbles 1-3 nm in diameter were observed in TEM at a concentration of 4.6 at.% He. Some bubbles remained isolated, while others formed chains 10-30 nm in length parallel to the surface. GIXRD measurements showed lattice swelling after irradiating pristine Gd2Zr2O7 with 7 MeV Au3+ to a fluence of 2.2 x 1015 Au/cm2. An increase in lattice swelling was also measured after 2.2 x 1015 Au/cm2 + 2 x 1015 He/cm2 and 2.2 x 1015 Au/cm2 + 2 x 1016 He/cm2. A decrease in lattice swelling was measured after irradiation with 2.2 x 1015 Au/cm2 + 2 x 1017 He/cm2, the fluence where bubbles and bubble chains were observed in TEM. Bubble chains are thought to form in order to reduce lattice strain normal to the surface, which is produced by the Au and He irradiation damage.

  1. First-principles study of disordering tendencies in Gd2B2O7 (B = Ti, Sn, Zr) compounds

    International Nuclear Information System (INIS)

    This paper performs the density functional theory calculations to obtain some factors influencing the response of pyrochlores Gd2B2O7 (B = Ti, Sn, Zr) to ion irradiation-induced amorphization. The 48f oxygen position parameter x, cohesive energy, bond type and defect-formation energy are discussed. The results show that parameter x can be used to indicate the disordering tendencies within a given pyrochlore family. Bond type, cohesive energy and defect-formation energies can be used to explain some experimental observations, but they are not determined exclusively by radiation “resistance” for a different pyrochlore family. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  2. Flexible Gd2O2S:Tb scintillators pixelated with polyethylene microstructures for digital x-ray image sensors

    International Nuclear Information System (INIS)

    Flexible scintillators for digital x-ray image sensors were designed, fabricated and characterized. In these scintillaotrs, terbium-doped gadolinium oxysulfide (Gd2O2S:Tb) scintillator pixels were embedded into a polyethylene (PE) substrate. To evaluate the difference in the spatial resolution according to the pixel size, we designed three scintillators with pixels of different pitch sizes: 50 µm pitch size (P50), 100 µm pitch size (P100) and 200 µm pitch size (P200). Because of the high flexibility and good formability, polyethylene was used as the substrate of the scintillator. To fabricate nickel micromolds with high-aspect-ratio microstructures, two microfabrication techniques were employed: silicon dry-etching using a deep reactive ion etching (DRIE) process and nickel electroforming. The pixelated PE microstructures were fabricated by a hot embossing process. Because the solution-type Gd2O2S:Tb precursor can be handled at room temperature, Gd2O2S:Tb was used as the scintillator material. The measured sensitivities of the P50 and P100 models were, respectively, about 65% and 97% of that of the P200 model. The lower sensitivity values of the models with a small pitch size were due to two factors, such as the different pixel heights and the different fill factors. Because a scintillator with a small pixel size has a low fill factor, the sensitivity of the scintillator decreases as the pixel size decreases. The fill factors of the P50, P100 and P200 models were 36%, 49% and 56.25%, respectively. On the other hand, the spatial resolution of the scintillator increases as the pixel size decreases. Therefore, P50 gave the best spatial resolution among the designed models. The spatial frequency at 10% of the modulation transfer function (MTF) with P50 was 13.5 mm−1, while that with P200 was 10.0 mm−1. The resolution pattern and the tooth x-ray images obtained from a scintillator with a smaller pixel size was also clearer than that obtained from a scintillator

  3. Solid state reaction synthesis and luminescence properties of Dy3+-doped Gd2Mo3O9 phosphor

    International Nuclear Information System (INIS)

    Gd2Mo3O9 phosphors with various Dy3+ concentrations were synthesized by a traditional solid-state reaction using Na2CO3 as a flux. The influence of reaction temperature and Dy3+-doping concentration on the crystal structure of the phosphors was examined by XRD (X-ray diffraction). The effect of Dy3+-doping concentration on the emissions of Mo–O bond and Dy3+ was experimentally investigated. The energy transfers between host and Dy3+ ions, and between Dy3+ ions were analyzed based on both the Van Uitert and I-H models. The chromatic properties of the phosphors were also discussed.

  4. Magnetic nanoparticles induced dielectric enhancement in (La, Gd)2O3: SiO2 composite systems

    Science.gov (United States)

    Kao, T. H.; Mukherjee, S.; Yang, H. D.

    2013-11-01

    Magnetic Gd2O3 and non-magnetic La2O3 nanoparticles (NPs) have been synthesized together with different doping concentrations in SiO2 matrix via sol-gel route calcination at 700 °C and above. Properly annealed NP-glass composite systems show enhancement of dielectric constant and magnetodielectric effect (MDE) near room temperature, depending on superparamagnetic NPs concentrations. From application point of view, the enhancement of dielectric constant along with MDE can be achieved by tuning the NPs size through varying calcination temperature and/or increasing the doping concentration of magnetic rare earth oxide.

  5. Euphorbia tirucalli mediated green synthesis of rose like morphology of Gd2O3:Eu3+ red phosphor: Structural, photoluminescence and photocatalytic studies

    International Nuclear Information System (INIS)

    Highlights: • Various morphology of Gd2O3:Eu3+ nanoparticles were synthesized using E-tirucalli plant latex as a fuel. • These nanoparticles were characterized by PXRD, SEM, UV–Vis and PL. • Eu3+ doped Gd2O3 is a promising single phased red phosphor. • Gd2O3:Eu3+ (7 mol%, 1 ml) nanophosphor exhibits superior photocatalytic activity. - Abstract: Eco-friendly, cost effective and bio template route was used for the preparation of cubic Gd2O3:Eu3+ nanophosphors using Euphorbia tirucalli (E. tirucalli) plant latex as fuel. As – formed Gd2O3:Eu3+ (7 mol%, 1–7 ml), calcined Gd2O3:Eu3+ (7 mol%, 1–7 ml) and Gd2O3:Eu3+ (1–11 mol%, 7 ml) samples were characterized using XRD, SEM and UV–Vis absorption spectrophotometer. With increase in latex concentration, the nanophosphor gets transformed from nano plates to rose – like nanoflowers with size varying from 20 to 30 nm. X-ray diffraction pattern of as – formed product shows hexagonal Gd (OH)3: Eu3+ phase and it converts to pure cubic phase of Gd2O3:Eu3+ on calcination at 600 °C for 3 h. Rietveld refinement of Gd2O3:Eu3+ (7 mol%, 7 ml) revealed the presence of cations in the 8b (0.25, 0.25, 0. 25) and 24d positions (−0.0287, 0.00, 0. 25) and the anions in the 48e positions (0.39, 0.15, 0. 37) with space group Ia-3(206). The photoluminescence intensities of transitions between different J levels depend on the symmetry of the local environment of Eu3+ ion activators and the high ratio of intensity of (5D0 → 7F2) and (5D0 → 7F1) provides the conclusion that Eu3+ ion occupies sites with a low symmetry and without an inversion centre. The chromaticity and the CIE coordinates were very close to the standard red color region. The absorption observed in the excitation spectra shows the suitability of the nanophosphor obtained in this study for getting excited in UV, NUV and visible regions for variety of display applications. Further, the Gd2O3:Eu3+ (7 mol%, 1–7 ml) samples were experimented towards the

  6. Preparation and upconversion luminescence of monodisperse Gd2O3∶Ho3+,Yb3+ nanocrystals

    Institute of Scientific and Technical Information of China (English)

    PENG Lingling; LIU Bitao; HAN Tao

    2013-01-01

    Gd2O3∶Ho3+,Yb3+ nanocrystals were synthesized via solvothermal method.X-ray diffraction (XRD),transmission electron microscopy (TEM),absorption and upconversion spectra were employed to characterize the synthesized nanocrystals.The results of XRD and TEM showed that obtained Gd2O3∶Ho3+,Yb3+ nanocrystals were cubic in crystal structure and uniform spherical in morphology.The average crystallite size was calculated to be 7.5 nm.Green and red up-conversion emissions corresponding to (5F4,5S2)→5I8 and 5F5→5I8 transition were observed upon 980 nm excitation at room temperature.The results indicated that both green and red luminescence were based on the two-photon processes.Laser power and doping concentration dependence of the upconverted emissions were studied to understand the upconversion mechanisms.Excited state absorption and energy-transfer processes were discussed as the possible mechanisms for the visible emissions.

  7. Percolation threshold near the second phase transition in diluted system of Gd2-x(La, Y)xIn

    International Nuclear Information System (INIS)

    In this paper it is demonstrated that the second phase transition of Gd2In intermetallic compound gets eliminated by diluting Gd2-x(LaY)xIn at a critical composition of x=0.5. The exchange coupling for intra-cluster interactions is estimated in the correlation ranges of 3.3 ACC>4 A where the correlation length is defined as RC=kF|R→i-R→j|. The sign and strength of the exchange coupling are identified by the eigenvalues λ(k) and are obtained from zeros of the 4x4 matrix of JijRR' along the three directions of the reciprocal lattice for each dilution (x=0.25, 0.5, 0.75, 1). The transition temperature is calculated using the minimum eigenvalue λmin (k=0, π) which agrees with the experiment. Magnetic field and temperature dependence of the magnetization and electrical resistivity measurements show that: (i) Elimination of the AFM phase is caused by breaking of some FM short-range exchange couplings, and (ii) Conduction electrons order antiferromagnetically at low temperatures and ferromagnetically at high temperatures.

  8. A co-precipitation preparation, crystal structure and photoluminescent properties of Er5%:Gd2O3 nanorods

    International Nuclear Information System (INIS)

    An inexpensive preparation method is being reported for obtaining erbium doped gadolinium oxide (Er5%:Gd2O3) nanoscale rods. The elongated nanoscale systems, as-formed through a co-precipitation process, are characterized by using X-ray powder diffraction (XRD) patterns, scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) mapping, Ultra Violet-visible (UV-vis.) absorption spectroscopy and photoluminescence (PL) spectroscopy. In addition, the Williamson–Hall (W–H) plot is also performed to distinguish the effect of crystalline size-induced broadening and strain-induced broadening at full-width at half-maximum (FWHM) of the XRD profile. The XRD patterns of as-formed and calcined products show that the phase confirmation. As revealed from the SEM micrographs, the morphology of the products show that the rod-like nanoparticles. The EDX micrographs show that the presence of elements in our samples. The band gap values in calcined samples are found to be in the range of 3.569 eV. Upon 230 nm excitation on calcined samples, three broad emission peaks are observed from PL studies. The possible mechanism for the formation of Er5%:Gd2O3 nanorods is briefly discussed

  9. Synthesis of GdF3 from the Gd2O3-NH4HF2 system

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    GdF3 was synthesized with Gd2O3 and NH4HF2 under atmospheric pressure and vacuum. The effects of pressure,temperature, and reactant ratio on the reaction process were investigated. A new mechanism for the synthesis of GdF3 was proposed. Powdered Gd2O3 started to react with NH4HF2 at low temperature, and the products were GdNH4F4, NH4F, NH3,and H2O. GdNH4F4 decomposed to GdF3 and NH4F after further high-temperature treatment, accompanying the volatilization and decomposition of NH4F. The whole process could be divided into three steps: synthesis, decomposition, and deamination. The initial and final reaction temperatures decreased under vacuum condition. An optimized process for the preparation of GdF3 was obtained: synthesis under atmospheric pressure at low temperature and decomposition and deamination under vacuum at high temperature.

  10. Fast crystallization of amorphous Gd2Zr2O7 induced by thermally activated electron-beam irradiation

    International Nuclear Information System (INIS)

    We investigate the ionization and displacement effects of an electron-beam (e-beam) on amorphous Gd2Zr2O7 synthesized by the co-precipitation and calcination methods. The as-received amorphous specimens were irradiated under electron beams at different energies (80 keV, 120 keV, and 2 MeV) and then characterized by X-ray diffraction and transmission electron microscopy. A metastable fluorite phase was observed in nanocrystalline Gd2Zr2O7 and is proposed to arise from the relatively lower surface and interface energy compared with the pyrochlore phase. Fast crystallization could be induced by 120 keV e-beam irradiation (beam current = 0.47 mA/cm2). The crystallization occurred on the nanoscale upon ionization irradiation at 400 °C after a dose of less than 1017 electrons/cm2. Under e-beam irradiation, the activation energy for the grain growth process was approximately 10 kJ/mol, but the activation energy was 135 kJ/mol by calcination in a furnace. The thermally activated ionization process was considered the fast crystallization mechanism

  11. Association of Anti-GT1a Antibodies with an Outbreak of Guillain-Barre Syndrome and Analysis of Ganglioside Mimicry in an Associated Campylobacter jejuni Strain.

    Directory of Open Access Journals (Sweden)

    Maojun Zhang

    Full Text Available An outbreak of Guillain-Barré syndrome (GBS, subsequent to Campylobacter jejuni enteritis, occurred in China in 2007. Serum anti-ganglioside antibodies were measured in GBS patients and controls. Genome sequencing was used to determine the phylogenetic relationship among three C. jejuni strains from a patient with GBS (ICDCCJ07001, a patient with gastroenteritis (ICDCCJ07002 and a healthy carrier (ICDCCJ07004, which were all associated with the outbreak. The ganglioside-like structures of the lipo-oligosaccharides of these strains were determined by mass spectrometry. Seventeen (53% of the GBS patients had anti-GT1a IgG antibodies. GT1a mimicry was found in the lipo-oligosaccharides of strain ICDCCJ07002 and ICDCCJ07004; but a combination of GM3/GD3 mimics was observed in ICDCCJ07001, although this patient had anti-GT1a IgG antibodies. A single-base deletion in a glycosyltransferase gene caused the absence of GT1a mimicry in ICDCCJ07001. The phylogenetic tree showed that ICDCCJ07002 and ICDCCJ07004 were genetically closer to each other than to ICDCCJ07001. C. jejuni, bearing a GT1a-like lipo-oligosaccharide, might have caused the GBS outbreak and the loss of GT1a mimicry may have helped ICDCCJ07001 to survive in the host.

  12. Synthesis and luminescence of high-brightness Gd2O2SO4:Tb3+ nanopieces and the enhanced luminescence by alkali metal ions co-doping

    International Nuclear Information System (INIS)

    Gd2O2SO4:Tb3+ nanopieces were synthesized by a combined approach of electrospinning and calcination at 1000 °C in mixed gas of sulfur dioxide and air. The nanopieces excited by a 230 nm light showed excellent green luminescence with the strongest emission peak at 545 nm due to the 5D4→7F5 transition of Tb3+. Interestingly, the intensity of emission peak at 545 nm of Gd2O2SO4:Tb3+ nanopieces exhibited about two times stronger than that of the bulk Gd2O2SO4:Tb3+ at the same doping concentrations of Tb3+. Besides, the effects of alkali metal ions doping on the luminescence of the nanopieces have been examined. The emission intensities were further enhanced by alkali metal ions doping, especially for Gd2O2SO4:Tb3+/Li+. The optimal doping concentration of Li+ was 7%. -- Highlights: •Gd2O2SO4:Tb3+ nanopieces were prepared via electrospinning followed by calcination. •A comparison between the nanopieces and the bulk was conducted. •The effects of alkali metal ions on the luminescence of nanopieces are examined. •The content of co-dopant in nanopieces is optimized. •The potential applications of the nanopieces and the facile method are suggested

  13. Upconversion emission enhancement in silica-coated Gd2O3:Tm3+, Yb3+ nanocrystals by incorporation of Li+ ion

    International Nuclear Information System (INIS)

    Silica-coated Tm3+, Yb3+, Li+-tridoped Gd2O3 nanocrystals (GTYLS) were prepared by a reverse microemulsion method. The blue upconversion luminescence intensity of this nanocomposite was enhanced remarkably by the incorporation of Li+ ions as compared with that of lithium-free Gd2O3:Tm3+, Yb3+-SiO2 (GTYS) nanocomposites. X-ray diffraction patterns (XRD) of GTYS and GTYLS revealed that Gd2O3 were cubic, silica shell was noncrystalline. The transmission electron microscope (TEM) photographs showed that the core of GTYLS was crystalline with the size of 50-60 nm, and the size of silica shell was about 15 nm. FT-IR spectra indicated that the absorption bands of OH became weaker with increasing the concentration of Li+. The enhanced luminescence is due to the distortion of the local asymmetry around Tm3+ and the decrease of OH generated by Li+ ion incorporation in the lattices.

  14. α-Gd2S3 -type structure in In2O3 : Experiments and theoretical confirmation of a high-pressure polymorph in sesquioxide

    Science.gov (United States)

    Yusa, Hitoshi; Tsuchiya, Taku; Tsuchiya, Jun; Sata, Nagayoshi; Ohishi, Yasuo

    2008-09-01

    A high-pressure phase, orthorhombic α-Gd2S3 type, was found in In2O3 as a post- Rh2O3(II) phase at pressures over 40 GPa by using an in situ x-ray diffraction method. This structure is composed of unusual sevenfold and eightfold coordinated cations, which has not been predicted for any sesquioxides to date. Compared with the known post- Rh2O3(II) transition to the CaIrO3 structure, this transition to α-Gd2S3 yields a considerable volume change. Density functional lattice energy calculations also show that the transition to α-Gd2S3 is more favorable than the transition to CaIrO3 in In2O3 .

  15. Effects of Ti addition and annealing on high-k Gd2O3 sensing membranes on polycrystalline silicon for extended-gate field-effect transistor applications

    International Nuclear Information System (INIS)

    Gadolinium oxide (Gd2O3) and gadolinium titanium oxide (Gd2TiO5) sensing membranes were deposited on polysilicon substrates and applied in the extended-gate field-effect transistor (EGFET) for pH detection. Effects of Ti addition and annealing on the sensing films have been investigated by multiple material analyses and electrical characterizations. The sensing performance could be improved with proper post-annealing and Ti addition because of reinforcements of crystalline structures and electrical reliability. Gd2TiO5 sensing membranes annealed at a temperature of 800 °C could achieve high sensitivity, high linearity, low hysteresis voltage, and a low drift ratio, which is promising for future generation of bio-medical device applications.

  16. Extracellular biosynthesis of gadolinium oxide (Gd2O3 nanoparticles, their biodistribution and bioconjugation with the chemically modified anticancer drug taxol

    Directory of Open Access Journals (Sweden)

    Shadab Ali Khan

    2014-03-01

    Full Text Available As a part of our programme to develop nanobioconjugates for the treatment of cancer, we first synthesized extracellular, protein-capped, highly stable and well-dispersed gadolinium oxide (Gd2O3 nanoparticles by using thermophilic fungus Humicola sp. The biodistribution of the nanoparticles in rats was checked by radiolabelling with Tc-99m. Finally, these nanoparticles were bioconjugated with the chemically modified anticancer drug taxol with the aim of characterizing the role of this bioconjugate in the treatment of cancer. The biosynthesized Gd2O3 nanoparticles were characterized by UV–vis spectroscopy, transmission electron microscopy (TEM, X-ray diffraction (XRD and X-ray photoemission spectroscopy (XPS. The Gd2O3–taxol bioconjugate was confirmed by UV–vis spectroscopy and fluorescence microscopy and was purified by using high performance liquid chromatography (HPLC.

  17. New single-phase, white-light-emitting phosphors based on δ-Gd 2Si2O7 for solid-state lighting

    OpenAIRE

    Fernández-Carrión, A.J.; Ocaña, Manuel; García-Sevillano, J.; Cantelar, Eugenio; Becerro, Ana Isabel

    2014-01-01

    Two new white-light (WL)-emitting phosphors (δ-Gd2Si 2O7:Dy and δ-Gd2Si2O 7:Eu,Tb) have been synthesized by the sol-gel method. The Gd-Ln 3+ (Ln3+= Dy3+, Tb3+, Eu 3+) energy-transfer band has been used to excite both phosphors, which provides an enhancement of the Ln3+ emissions. First, WL was generated from δ-Gd2Si2O7:xDy thanks to the particular ratio of the blue and yellow emissions observed in all three compositions, which had chromatic coordinates of x = 0.30, y = 0.33 and CCT values of ...

  18. Synthesis and characterization of Gd 2O 3:Eu 3+ phosphor nanoparticles by a sol-lyophilization technique

    Science.gov (United States)

    Louis, C.; Bazzi, R.; Flores, Marco A.; Zheng, W.; Lebbou, K.; Tillement, O.; Mercier, B.; Dujardin, C.; Perriat, P.

    2003-07-01

    The characterization and luminescence properties of nanostructured Gd 2O 3:Eu 3+ phosphors synthesized by a sol-lyophilization process are presented. After preparation of gadolinium-based sols from gadolinium nitrate and ammonium hydroxide, the so-prepared sols were freeze dried at -10°C and calcinated at different temperatures. For temperatures lower than 1300 K, highly crystalline samples with the cubic structure can be obtained without concomitant grain growth of the particles (<50 nm). The luminescence spectra contain all possible transitions of Eu 3+ with C2 symmetry and present two major features: an increase of the luminescence efficiencies of the phosphors in comparison with that obtained by solid-state reaction and the presence of an additional peak at about 609 nm at the vicinity of the 5D0→ 7F0…4 transition.

  19. Synthesis and optical characterization of Gd2O3:Eu3+ nanocrystals: surface states and VUV excitation

    International Nuclear Information System (INIS)

    This paper reports on the synthesis and characterization of Gd2O3:Eu3+ nanocrystals of different sizes. The particles have been synthesized by a sol-lyophilization process. This methods allows the synthesis of 7-100 nm diameter cubic-phase particles. The photoluminescence properties have been studied with different excitation from X-ray to VUV and visible wavelengths. Compared to the properties of the bulk materials, some important changes on the luminescence are observed. In particular some bands are strengthened when the size of the particles is diminished. We could therefore ascribe this bands to doping ions on a site close to the surface. Also a very low efficiency of excitation for small particles is observed when exciting with X-ray or high-energy VUV photons (i.e. when exciting the host matrix) compared to the efficiency obtained when exciting in the charge transfer band or in the doping ions related states

  20. Synthesis and characterization of Gd2O3:Eu3+ phosphor nanoparticles by a sol-lyophilization technique

    International Nuclear Information System (INIS)

    The characterization and luminescence properties of nanostructured Gd2O3:Eu3+ phosphors synthesized by a sol-lyophilization process are presented. After preparation of gadolinium-based sols from gadolinium nitrate and ammonium hydroxide, the so-prepared sols were freeze dried at -10 deg. C and calcinated at different temperatures. For temperatures lower than 1300 K, highly crystalline samples with the cubic structure can be obtained without concomitant grain growth of the particles (3+ with C2 symmetry and present two major features: an increase of the luminescence efficiencies of the phosphors in comparison with that obtained by solid-state reaction and the presence of an additional peak at about 609 nm at the vicinity of the 5D0→7F0...4 transition

  1. Facile synthesis of catalytically active CeO2-Gd2O3 solid solutions for soot oxidation

    Indian Academy of Sciences (India)

    D Naga Durgasri; T Vinodkumar; Benjaram M Reddy

    2014-03-01

    CeO2-Gd2O3 oxides were synthesized by a modified coprecipitation method and subjected to thermal treatments at different temperatures to understand their thermal behaviour. The obtained samples were characterized by XRD, BET, TEM, Raman and TPR techniques. Catalytic efficiencies for oxygen storage/release capacity (OSC) and soot oxidation were evaluated by a thermogravimetric (TG) method. XRD and Raman results indicated the formation of Ce0.8Gd0.2O2− (CG) solid solutions at lower calcination temperatures, and TEM studies confirmed nanosized nature of the particles. Raman studies further confirmed the presence of oxygen vacancies and lattice defects in the CG sample. TPR measurements indicated a facile reduction of ceria after Gd3+ addition. Activity studies revealed that incorporation of Gd3+ into the ceria matrix favoured the creation of more structural defects, which accelerates the oxidation rate of soot compared to pure ceria.

  2. Performance of Ce-doped (La, Gd)2Si2O7 scintillator with an avalanche photodiode

    International Nuclear Information System (INIS)

    Scintillation properties of Ce-doped (La, Gd)2Si2O7 (Ce:La-GPS) crystal were measured with Si avalanche photodiode (APD, Hamamatsu S8664-55). Since Ce:La-GPS is a novel scintillator, its scintillation properties have been evaluated using the APD for the first time. This crystal grown by floating zone method had a good light output of 41,000±1000 photons/MeV and FWHM energy resolution at 662 keV was 4.4±0.1% at 23.0±0.2 °C. The photon non-proportional response (PNR) of Ce:La-GPS was approximately 65% at 32 keV, where light output at 662 keV was normalized to 100%. Moreover, the temperature dependence of the light outputs was determined to be approximately 0.15%/°C from −10 to 30 °C

  3. Speleology and magnetobiostratigraphic chronology of the GD 2 locality of the Gondolin hominin-bearing paleocave deposits, North West Province, South Africa.

    Science.gov (United States)

    Herries, Andy I R; Adams, Justin W; Kuykendall, Kevin L; Shaw, John

    2006-12-01

    Speleological, paleomagnetic, mineral magnetic, and biochronological analyses have been undertaken at the Gondolin hominin-bearing paleocave, North West Province, South Africa. Two fossiliferous but stratigraphically separate sequences, GD2 and GD1/3, which were once part of a large cavern system, have been identified. Although some comparative paleomagnetic samples were taken from the GD 1, 3, and 4 localities that are currently under investigation, the research presented here focuses on the fossil-rich, in situ deposits at locality GD 2, excavated by E.S. Vrba in 1979. The GD 2 deposits are dominated by normal-polarity calcified clastic deposits that are sandwiched between clastic-free flowstone speleothems. The lower flowstone has a sharp contact with the red siltstone deposits and is of reversed polarity. The capping flowstone shows a change from normal to reversed polarity, thereby preserving a polarity reversal. While the paleomagnetic work indicates that the GD 2 fossil material was deposited during a normal-polarity period, the shortness of the sequence made matching of the magnetostratigraphy to the geomagnetic polarity time scale (GPTS) impossible without the aid of biochronology. While lacking multiple time-sensitive taxa, the recovery of specimens attributable to Stage III Metridiochoerus andrewsi is consistent with a deposition date between 1.9 and 1.5 Ma. A comparison of the magnetostratigraphy with the GPTS therefore suggests that the fauna-bearing siltstone of GD 2 date to the Olduvai normal-polarity event, which occurred between 1.95 and 1.78 Ma, and that the reversal from normal to reversed polarity identified in the capping flowstone dates to 1.78 Ma. The main faunal layers therefore date to slightly older than 1.78 Ma. Deposits from the GD 1 locality are dominated by reversed directions of magnetization, which show that this deposit is not of the same age as the faunal layers from the GD 2 locality. PMID:16949648

  4. Radial distribution of UO2 and Gd2O3 in fuel cells of a BWR Reactor

    International Nuclear Information System (INIS)

    The fuel system that is used at the moment in a power plant based on power reactors BWR, includes as much like the one of its substantial parts to the distribution of the fissile materials like a distribution of burnt poisons within each one of the cells which they constitute the fuel assemblies, used for the energy generation. Reason why at the beginning of a new operation cycle in a reactor of this type, the reactivity of the nucleus should be compensated by the exhaustion of the assemblies that it moves away of the nucleus for their final disposition. This compensation is given by means of the introduction of the recharge fuel, starting from the UO2 enriched in U235, and of the Gadolinium (Gd2O3). The distribution of these materials not only defines the requirements of energy generation, but in certain measures also the form in that the margins will behave to the limit them thermal during the operation of the reactor. These margins must be taken into account for the safe and efficient extraction of the energy of the fuel. In this work typical fuel cells appear that are obtained by means of the use of a emulation model of an ants colony. This model allows generating from a possible inventory of values of enrichment of U235, as well as of concentration of Gadolinium a typical fuel cell, which consists of an arrangement of lOxlO rods, of which 92 contain U235, some of these rods contain a concentration of Gd2O3 and 8 of the total contain only water. The search of each cell finishes when the value of the Local Peak Power Factor (LPPF) in the cell reaches a minimal value, or when a pre established value of iterations is reached. The cell parameters are obtained from the results of the execution of the code HELIOS, which incorporates like a part integral of the search algorithm. (Author)

  5. Novel nanocrystalline Gd2O3(Eu) scintillator screens with a micro-pixel structure for high spatial resolution X-ray imaging

    International Nuclear Information System (INIS)

    We developed a novel pixel-structured scintillation screen with nanocrystalline Gd2O3:Eu particle sizes for high spatial resolution X-ray imaging detectors. Nanocrystalline Gd2O3:Eu scintillators were successfully synthesized with a hydrothermal method and a subsequent calcination treatment, which were used as a material for converting incident X-rays into visible light. In this work, silicon-based pixel structures with different 100, 50 and 30 μm pixel sizes, a 10 μm wall width and a 120 μm thickness were prepared with the standard photolithography and the deep reactive ion etching (DRIE) process. Subsequently, a micro-pixel-structured scintillation screen was fabricated by adding the synthesized nanocrystalline Gd2O3:Eu scintillating phosphor to pixel-structured silicon arrays. Additionally, X-ray imaging performance such as relative light intensity, X-ray to light response and the spatial resolution in terms of modulation transfer function (MTF) were measured by using an X-ray source and a lens-coupled charge coupled device (CCD) camera system. The light intensity of the pixel-structured nanocrystalline Gd2O3:Eu screen was much higher than that of a pixel-structured sample made with a commercial microcrystalline Gd2O3:Eu product due to the density of the nanocrystalline Gd2O3:Eu scintillating powder-filled silicon structure. As the pixel size of the pixel-structured silicon decreased, the light intensity decreased. However, as the pixel size decreased, the spatial resolution significantly improved with no evident crosstalk from the emitted optical photons between adjacent scintillating pixels. The MTF of pixel-structured nanocrystalline Gd2O3:Eu screens with a 100 and a 50 μm pixel size was 20% and 30% at 6 lp/mm, respectively. As a result, this new technology showed that a microchannel structure based on a nanocrystalline Gd2O3:Eu scintillator could provide higher light intensity and high spatial resolution imaging compared to conventional microcrystalline

  6. Magnetic and magnetocaloric properties of Gd2In0.8X0.2 compounds (X=Al, Ga, Sn, Pb)

    Science.gov (United States)

    Tencé, Sophie; Chevalier, Bernard

    2016-02-01

    We show that it is possible to replace in Gd2In some amount of In by X=Al, Ga, Sn and Pb to obtain Gd2In1-xXx samples after melting. The magnetic and magnetocaloric properties of the Gd2In0.8X0.2 intermetallic compounds have been investigated through dc magnetization measurements. We evidence that the substitution of Al and Ga for In barely changes the Curie temperature TC but decreases the second magnetic transition temperature T‧ which corresponds to the transition from a ferromagnetic to an antiferromagnetic state. On the other hand, the substitution of Sn and Pb for In strongly increases TC and changes the nature or even suppresses the transition at lower temperature. This magnetic behavior gives rise to an interesting way to tune the Curie temperature near room temperature without diluting the Gd network and thus to modify the magnetocaloric effect in Gd2In1-xXx compounds.

  7. The luminescence properties of Bi3+ sensitized Gd2MoO6:RE3+ (RE = Eu or Sm) phosphors for solar spectral conversion

    Science.gov (United States)

    Huang, M. N.; Ma, Y. Y.; Huang, X. Y.; Ye, S.; Zhang, Q. Y.

    2013-11-01

    Gd2MoO6:RE3+ (RE = Eu or Sm) and Gd2MoO6:Bi3+, RE3+ (RE = Eu or Sm) phosphors have been synthesized by combustion method. The samples are characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), photoluminescence excitation (PLE) and photoluminescence (PL) spectra. By introducing Bi3+ ions into Gd2MoO6:RE3+ (RE = Eu or Sm) phosphors, the excitation bands of Eu3+ and Sm3+ ions are broadened and shifted to short wavelength, meanwhile, the emission intensity are enhanced obviously. The energy transfer from Bi3+ to the activators of Eu3+ or Sm3+ is observed and discussed. In addition, the process of ultraviolet light (250-400 nm) converted into visible light can be achieved by using Gd2MoO6:Bi3+, RE3+ (RE = Eu or Sm) phosphor. These phosphors can be a promising ultraviolet-absorbing luminescent converter to enhance the photoelectrical conversion efficiency of dye-sensitized solar cells (DSSCs).

  8. The properties of Gd2O3-assembled silica nanocomposite targeted nanoprobes and their application in MRI.

    Science.gov (United States)

    Shao, Yuanzhi; Tian, Xiumei; Hu, Wenyong; Zhang, Yongyu; Liu, Huan; He, Haoqiang; Shen, Yingying; Xie, Fukang; Li, Li

    2012-09-01

    The feasibility of the gadolinium-doped mesoporous silica nanocomposite Gd(2)O(3)@MCM-41 as a safe, effective MRI nanoprobe has been validated in the current investigation systematically from atomistic and molecular modeling to its synthesis and characterization on in vivo MR imaging and biocompatibility. The first-principles calculation indicates that it is nearly impossible for toxic Gd ions to dissociate freely from silica. The biocompatibility studies confirm that the nanocomposite is lack of any potential toxicity; the biodistribution studies reveal a greater accumulation of the nanocomposite in liver, spleen, lung and tumor than in kidney, heart and brain; the excretion studies show that the nanocomposite can be cleared nearly 50% via the hepatobiliary transport mechanism after 1.5 months of injection. A larger water proton relaxivity r(1) and a better T(1)-weighted phantom MR imaging capability were detected in the nanocomposite than in the commercially available gadolinium diethylenetriaminepentaacetate. The results demonstrate that the nanocomposite is superior to the commercial counterpart in terms of contrast enhancement with a satisfactory biocompatibility, and it has a high potential to be developed into a safe and effective targeted probe for in vivo molecular imaging of cancer. PMID:22704842

  9. Annealing effects on the photoluminescence yield of Gd2O3:Eu nanoparticles produced by solution combustion synthesis

    International Nuclear Information System (INIS)

    Post-synthesis annealing is commonly required to achieve intense luminescence from nanoparticles synthesized by means of the solution combustion synthesis (SCS) method. We carried out investigation to gain insight on the underpinning mechanisms related to this enhancement. Gd2O3:Eu nanoparticles were prepared by SCS and characterized in their structure, crystallinity, crystallite size, photoluminescence (PL) and PL lifetime. After synthesis, samples were calcined at 500 oC for 4 h to eliminate organic residues, and annealed in air at 1000 oC for up to 180 min. The fast increase of PL intensity in the first ∼15 min of annealing is understood by the decrease of the probability of non-radiative recombination through the elimination of quenching defects. This is in agreement with increasing crystallinity, as determined by the absolute intensity of the (222) and (440) diffraction peaks as a function of annealing time. The systematic measurements of crystallinity, crystallite size, PL intensity and lifetime as a function of annealing time carried out in this work supports the assignment of a major role to crystallization and the elimination of structural disorder on PL yield of SCS-prepared materials.

  10. Corrosion behavior of Mg-10Gd-2Y-0.4Zr alloy under thin electrolyte layers

    Energy Technology Data Exchange (ETDEWEB)

    Chen, C. [Corrosion and Protection Lab., Key Lab. of Superlight Materials and Surface Technology (Harbin Engineering Univ.), Ministry of Education, Harbin (China); Zhang, T.; Meng, G.; Shao, Y.; Wang, F. [Corrosion and Protection Lab., Key Lab. of Superlight Materials and Surface Technology (Harbin Engineering Univ.), Ministry of Education, Harbin (China); State Key Lab. for Corrosion and Protection, Inst. of Metal Research, Chinese Academy of Sciences, Shenyang (China); Li, X. [State Key Lab. for Corrosion and Protection, Inst. of Metal Research, Chinese Academy of Sciences, Shenyang (China); Corrosion and Protection Center, Univ. of Science and Technology Beijing (China); Dong, C. [Corrosion and Protection Center, Univ. of Science and Technology Beijing (China)

    2010-05-15

    The corrosion behavior of Mg-10Gd-2Y-0.4Zr (GW102K) alloy under thin electrolyte layer (TEL) with various thicknesses was investigated by means of cathodic polarization curve, electrochemical impedance spectroscopy (EIS), and electrochemical noise (EN). Based on shot noise theory and stochastic theory, the EN results were quantitatively analyzed by using the Weibull and Gumbel distribution function, respectively. The experimental results showed that the anodic and cathodic processes of the corrosion of GW102K alloy were both retained under thin electrolyte layers. Whether under TEL or not, the cathodic process was dominated by hydrogen evolution reaction. The corrosion was more localized under thin electrolyte layer than that in bulk solution. The results also demonstrated that there were two kinds of effects for thin electrolyte layer on the corrosion behavior of GW102K alloy: (i) the rate of pit initiation was evidently retarded compared to that in bulk solution; (ii) the probability of pit growth decreased, which should be the real reason why the corrosion rate of GW102K alloy decreased with the decrease in layer thickness. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  11. Analysis of core physics experiments on MOX assemblies loaded with Gd2O3-UO2 and UO2 rods

    International Nuclear Information System (INIS)

    In order to extend the database for validation of nuclear design calculations on BWR MOX cores, the Japan Nuclear Energy Safety Organization (JNES) has implemented the MOX core physics experimental program FUBILA that is aimed at obtaining the characteristics of full MOX BWR cores consisting of high Pu-enriched BWR MOX assemblies to achieve high burnups. One of the FUBILA cores was composed of the MOX assemblies loaded with Gd2O3-UO2 and UO2 fuel rods. The critical mass and core fission rate distributions were measured. The core analyses using deterministic calculation codes and a continuous energy Monte Carlo code with nuclear data libraries JENDL-3.3. ENDF/B-VI.8, -VII and JEFF-3.1 show that the critical keff's are 0.999 - 1.006. The calculated relative fission rate distributions slightly underestimate the fission rates of the Cd2O3-UO2 and/or UO2 fuel rods and overestimate those of the MOX rods. (author)

  12. Up-converted ultraviolet luminescence of Er3+:BaGd2ZnO5 phosphors for healthy illumination

    Science.gov (United States)

    Zhang, Ya; Cui, Qingzhi; Wang, Zhanyong; Liu, Gan; Tian, Tian; Xu, Jiayue

    2016-09-01

    Moderate level of exposure to the solar irradiation containing UV component is essential for health care. To incorporate the UV-emitting phosphors into the commercial YAG-based white light-emitting diode introduces the possibilities of healthy illumination to individuals' daily lives. 1 mol.% Er3+-doped BaGd2ZnO5 (BGZ) particles were synthesized via sol-gel method and efficient up-converted luminescence peaked at 380 nm was detected under 480 nm excitation. The mixed phosphors with varied mass ratio of Er3+:BGZ and Ce3+:YAG particles were encapsulated to form LEDs. The study of the LEDs indicated that the introduction of BGZ component favored the enhancement of color-rendering index and the neutralization of the white light emitting. The WLED with the BGZ/YAG ratio of 8:2 was recommendable for its excellent overall white light luminous performances and UV intensity of 84.55 mW/cm2. The UV illumination dose of the WLEDs with mixed YAG and BGZ was controllable by adjusting the ratio, the illumination distance and the illumination time. Er3+:BGZ phosphors are promising UVemitting phosphors for healthy indoor illumination.

  13. Effect of Li+ ion sensitization and optical temperature sensing in Gd2O3: Ho3+/Yb3+

    Science.gov (United States)

    Singh, Priyam; Shahi, P. K.; Rai, Anita; Bahadur, A.; Rai, S. B.

    2016-08-01

    Ho3+/Yb3+ codoped Gd2O3 phosphor has been synthesized by solution combustion method. The concentrations of Ho3+ and Yb3+ were optimized to be 0.3 and 2.0 mol% respectively for maximum emission intensity. The effect of Li+ ion co-doping on phase structure and photo luminescence were investigated. It is found that there is no change in phase of the sample due to Li+ ion co-doping. However the Upconversion (UC) and Downshifting (DS) emission show a remarkable enhancement in intensity. It is concluded that, this enhancement in the emission intensity is mainly due to the change in crystal field around the Ho3+ ion and reduction in quenching centers. The optimum doping concentration of Li+ ion was found to be 20 mol%. We have further explored the temperature sensing behavior using the FIR technique. The maximum sensitivity is found to be 0.0092 K-1 at 505 K.

  14. A study on the oxidation characteristic of UO2-Gd2O3 pellet for recycling of burnable absorber pellet scrap

    International Nuclear Information System (INIS)

    The development of recycling process of defective (U,Gd)O2 scrap is one of the important subject in this project. Among the several burnable absorbers, Gd has a very large neutron absorption cross-section. Therefore, gadolinia bearing UO2 fuel, (U,Gd)O2, has been widely used as a burnable absorber in light water reactors. During the pellet fabrication process, fairly amount of defective (U,Gd)O2 pellets are produced and it is necessary to recycle the scraps. Generally, the defective scraps are powdered through the oxidation in air in the temperature range of 450 to 550 deg C and then mixed with co-milled powder, and further processed to fabricate (U,Gd)O2 pellets. In addition, the sintered pellet properties are closely depend on the powder property of oxidized M3O8 powder. Therefore, the careful investigate of oxidation kinetics and related powder property of (U,Gd)O2 is very important. The oxidation behavior of UO2-6wt% Gd2O3 and UO2-12wt% Gd2O3 has been studied in the temperature range from 350 to 700 deg C using TGA and XRD techniques in air. UO2 was necessarily oxidized to U3O8 regardless of oxidation temperature and its weight gain was 4wt%. However, (U,Gd)O2 exhibit a different oxidation behavior ; The final phase and saturated weight gain depends on oxidation temperature. The saturated weight gain increases with oxidation temperature up to 500deg C and thereafter decreases with temperature. In addition, the amount of weight gain obtained at 500 deg C was smaller in UO2-12wt% Gd2O3 than in UO2-6wt% Gd2O3 and the final phase at the saturated weight gain was M3O8 in UO2-6wt% Gd2O3 but the mixture of M4O9 and M3O8 in UO2-12wt% Gd2O3. It is supposed that Gd substitution for U decreases the equilibrium O/M ratio and thereby enhance the stability of M4O9 type cubic phase

  15. Thyroid Antibodies

    Science.gov (United States)

    ... be limited. Home Visit Global Sites Search Help? Thyroid Antibodies Share this page: Was this page helpful? Also known as: Thyroid Autoantibodies; Antithyroid Antibodies; Antimicrosomal Antibody; Thyroid Microsomal Antibody; ...

  16. Core/shell Fe3O4/Gd2O3 nanocubes as T1-T2 dual modal MRI contrast agents

    Science.gov (United States)

    Li, Fenfen; Zhi, Debo; Luo, Yufeng; Zhang, Jiqian; Nan, Xiang; Zhang, Yunjiao; Zhou, Wei; Qiu, Bensheng; Wen, Longping; Liang, Gaolin

    2016-06-01

    T1-T2 dual modal magnetic resonance imaging (MRI) has attracted considerable interest because it offers complementary diagnostic information, leading to more precise diagnosis. To date, a number of nanostructures have been reported as T1-T2 dual modal MR contrast agents (CAs). However, hybrids of nanocubes with both iron and gadolinium (Gd) elements as T1-T2 dual modal CAs have not been reported. Herein, we report the synthesis of novel core/shell Fe3O4/Gd2O3 nanocubes as T1-T2 dual-modal CAs and their application for enhanced T1-T2 MR imaging of rat livers. A relaxivity study at 1.5 T indicated that our Fe3O4/Gd2O3 nanocubes have an r1 value of 45.24 mM-1 s-1 and an r2 value of 186.51 mM-1 s-1, which were about two folds of those of Gd2O3 nanoparticles and Fe3O4 nanocubes, respectively. In vivo MR imaging of rats showed both T1-positive and T2-negative contrast enhancements in the livers. We envision that our Fe3O4/Gd2O3 nanocubes could be applied as T1-T2 dual modal MR CAs for a wide range of theranostic applications in the near future.T1-T2 dual modal magnetic resonance imaging (MRI) has attracted considerable interest because it offers complementary diagnostic information, leading to more precise diagnosis. To date, a number of nanostructures have been reported as T1-T2 dual modal MR contrast agents (CAs). However, hybrids of nanocubes with both iron and gadolinium (Gd) elements as T1-T2 dual modal CAs have not been reported. Herein, we report the synthesis of novel core/shell Fe3O4/Gd2O3 nanocubes as T1-T2 dual-modal CAs and their application for enhanced T1-T2 MR imaging of rat livers. A relaxivity study at 1.5 T indicated that our Fe3O4/Gd2O3 nanocubes have an r1 value of 45.24 mM-1 s-1 and an r2 value of 186.51 mM-1 s-1, which were about two folds of those of Gd2O3 nanoparticles and Fe3O4 nanocubes, respectively. In vivo MR imaging of rats showed both T1-positive and T2-negative contrast enhancements in the livers. We envision that our Fe3O4/Gd2O3 nanocubes

  17. Energy transfer and colorimetric properties of Eu3+/Dy3+ co-doped Gd2(MoO4)3 phosphors

    International Nuclear Information System (INIS)

    Dy3+ single-doped and Eu3+/Dy3+ co-doped gadolinium molybdate (Gd2(MoO4)3) phosphors were synthesized by a traditional solid-state reaction method. The XRD was used to confirm the crystal structure of the phosphors. The energy transfer between Eu3+ and Dy3+ was observed and studied. The Eu3+ concentration can hardly affect the blue and yellow emission intensities of Dy3+, and the Eu3+ emission intensity increases with the increase of Eu3+ concentration. Co-doping with Eu3+ compensated the red emission component of the Dy3+ doped Gd2(MoO4)3 phosphor. Introducing proper amount of Eu3+ can improve the colorimetric performance of the phosphors.

  18. UO2-7%Gd2O3 fuel process development by mechanical blending with reprocessing of waste products and usage of densification additive

    International Nuclear Information System (INIS)

    In the nuclear fuel cycle, reprocessing and storage of 'burned' fuels, either temporary or permanent, demand high investments and, in addition, can potentially generate environmental problems. A strategy to decrease these problems is to adopt measures to reduce the amount of waste generated. The usage of integrated burnable poison based on gadolinium is a measure that contributes to achieve this goal. The reason to use burnable poison is to control the neutron population in the reactor during the early life of the fresh reactor core or the beginning of each recharging fuel cycle, extending its cycle duration. Another advantage of using burnable poison is to be able to operate the reactor with higher burning rate, optimizing the usage of the fuel. The process of manufacturing UO2-Gd2O3 integrated burnable fuel poison generates waste that, as much as possible, needs to be recycled. Blending of Gd2O3 in UO2 powder requires the usage of a special additive to achieve the final fuel pellet specified density. The objective of this work is to develop the process of obtaining UO2 - 7% Gd2O3 integrated burnable poison using densification additives, aluminum hydroxide (Al(OH)3), and reprocessing manufacturing waste products by mechanical blending. The content of 7%- Gd2O3 is based on commercial PWR reactor fuels - Type Angra 2. The results show that the usage of Al(OH)3 as an additive is a very effective choice that promotes the densification of fuel pellets with recycle up to 10%. Concentrations of 0,20 % of Al(OH)3 were found to be the indicated amount on an industrial scale, specially when the recycled products come from U3O8 obtained by calcination of sintered pellets. This is particularly interesting because it is following the steps of sintering and rectifying of the pellets, which is generating the largest amounts of recycled material. (author)

  19. UO2-7%Gd2O3 fuel process development by mechanical blending with reprocessing of waste products and usage of densification additive

    International Nuclear Information System (INIS)

    In the nuclear fuel cycle, reprocessing and storage of 'burned' fuels, either temporary or permanent, demand high investments and, in addition, can potentially generate environmental problems. A strategy to decrease these problems is to adopt measures to reduce the amount of waste generated. The usage of integrated burnable poison based on gadolinium is a measure that contributes to achieve this goal. The reason to use burnable poison is to control the neutron population in the reactor during the early life of the fresh reactor core or the beginning of each recharging fuel cycle, extending its cycle duration. Another advantage of using burnable poison is to be able to operate the reactor with higher burning rate, optimizing the usage of the fuel. The process of manufacturing UO2-Gd2O3 integrated burnable fuel poison generates waste that, as much as possible, needs to be recycled. Blending of Gd2O3 in UO2 powder requires the usage of a special additive to achieve the final fuel pellet specified density. The objective of this work is to develop the process of obtaining UO2 - 7% Gd2O3 integrated burnable poison using densification additives, aluminum hydroxide (Al(OH)3), and reprocessing manufacturing waste products by mechanical blending. The content of 7%- Gd2O3 is based on commercial PWR reactor fuels - Type Angra 2. The results show that the usage of Al(OH)3 as an additive is a very effective choice that promotes the densification of fuel pellets with recycle up to 10%. Concentrations of 0,20 % of Al(OH)3 were found to be the indicated amount on an 7 industrial scale, specially when the recycled products come from U3O8 obtained by calcination of sintered pellets. This is particularly interesting because it is following the steps of sintering and rectifying of the pellets, which is generating the largest amounts of recycled material. (author)

  20. Passivation of the surfaces of single crystal gadolinium molybdate (Gd2(MoO4)3) against attack by hydrofluoric acid by inert ion beam irradiation

    International Nuclear Information System (INIS)

    The passivation effect from inert ion beam bombardment has been studied on a ferroelectric surface. The mechanism in these materials may have some additional contributions because of the polarization charges of the domains and the dipole effect (ion beam and surface species) on the surfaces. For these studies Gd2(MoO4)3 (GMO) crystals were selected. Two possible mechanisms of passivation of GMO surfaces when bombarded with ion beams are discussed

  1. Study of UO2-10WT%Gd2O3 fuel pellets obtained by seeding method using AUC co-precipitation and mechanical mixing processes

    International Nuclear Information System (INIS)

    The use of gadolinium and uranium mixed oxide as a nuclear fuel aims to obtain a fuel with a performance better than that of UO2 fuel. In this work, seeding method was used to improve ionic diffusivity during sintering to produce high density pellets containing coarse grains by co-precipitation and mechanical mixing processes. Sintered UO2-10 wt% Gd2O3 pellets were obtained using the reference processes with 2 wt% and 5 wt% UO2 seeds with two granulometries, less than 20 μm and between 20 and 38 μm. Characterisation was carried out by chemical analysis, surface area, X-ray diffraction, SEM, WDS, image analysis, and densitometry. The seeding method using mechanical mixing process was more effective than the co-precipitation method. Furthermore, mechanical mixing process resulted in an increase in density of UO2-10wt% Gd2O3 with seeds in relation to that of UO2-10wt% Gd2O3 without seeds. (author)

  2. Activation of human naïve Th cells increases surface expression of GD3 and induces neoexpression of GD2 that colocalize with TCR clusters.

    Science.gov (United States)

    Villanueva-Cabello, Tania M; Mollicone, Rosella; Cruz-Muñoz, Mario E; López-Guerrero, Delia V; Martínez-Duncker, Iván

    2015-12-01

    CD4+ T helper lymphocytes (Th) orchestrate the immune response after their activation by antigen-presenting cells. Activation of naïve Th cells is reported to generate the reduction in surface epitopes of sialic acid (Sia) in α2,3 and α2,6 linkages. In this work, we report that in spite of this glycophenotype, anti-CD3/anti-CD28-activated purified human naïve Th cells show a significant increase in surface Sia, as assessed by metabolic labeling, compared with resting naïve Th cells, suggesting an increased flux of Sia toward Siaα2,8 glycoconjugates. To understand this increase as a result of ganglioside up-regulation, we observed that very early after activation, human naïve Th cells show an increased expression in surface GD3 and neoexpression of surface GD2 gangliosides, the latter clustering with the T cell receptor (TCR). Also, we report that in contrast to GM2/GD2 synthase null mice, lentiviral vector-mediated silencing of the GM2/GD2 synthase in activated human naïve Th cells reduced efficient TCR clustering and downstream signaling, as assessed by proliferation assays and IL-2 and IL-2R expression, pointing to an important role of this enzyme in activation of human naive Th cells. PMID:26263924

  3. Magnetic and dielectric properties of layered perovskite Gd2Ti2O7 thin film epitaxially stabilized on a perovskite single crystal

    Science.gov (United States)

    Ukita, Takashi; Hirose, Yasushi; Ohno, Sawako; Hatabayashi, Kunitada; Fukumura, Tomoteru; Hasegawa, Tetsuya

    2012-04-01

    Layered perovskite (LP) titanates, Ln2Ti2O7 (Ln = lanthanoids), are ferroelectric materials containing magnetic Ln3+ ions at A-site. Metastable LP-Gd2Ti2O7 was fabricated in epitaxial thin film form on lattice-matched perovskite substrates and its dielectric and magnetic properties were investigated. The (100)-oriented LP-Gd2Ti2O7 films were epitaxially grown on (110) plane of (LaAlO3)0.3-(SrAl0.5Ta0.5O3)0.7 (LSAT) and Nb-doped SrTiO3 by using a pulsed laser deposition method. Piezoresponse force microscope measurements revealed that LP-Gd2Ti2O7 has spontaneous polarization along the b-axis at room temperature, strongly suggesting room temperature ferroelectricity. Magnetization measurements showed paramagnetic behavior with weak antiferromagnetic interaction around 2 K. Small positive magneto-dielectric effect (Δɛ/ɛ ˜ 10-5 order) was also confirmed at 10 K.

  4. Obtenção de cerâmicas ferroelétricas de Gd2Mo3O12 e o puxamento de fibras monocristalinas

    Directory of Open Access Journals (Sweden)

    Ferrari C. R.

    2001-01-01

    Full Text Available Nesse trabalho abordamos a obtenção do material cerâmico Gd2Mo3O12 na sua fase beta, denominado beta-GMO, utilizando-se do método convencional de mistura de óxidos e reação do estado sólido. MoO3 e o Gd2O3 nas razões molares 3:1 e 3,25:1 foram usados como pós de partida. Cerâmicas sinterizadas foram usadas como pedestais e sementes na produção de fibras monocristalinas pela técnica Laser Heated Pedestal Growth- LHPG. A cerâmica com fase única Gd2Mo3O12 foi melhor obtida usando a razão molar 3:1 entre os pós de partida. Por outro lado, fibras cristalinas obtidas a partir de pedestais cerâmicos com excesso de MoO3 apresentaram melhor qualidade óptica e a estequiometria desejada.

  5. Syntheses and characterization of Gd2Zr2-xCexO7(0.0≤x≤2.0)

    International Nuclear Information System (INIS)

    In order to get the physical properties, phase change and microstructure of waste forms containing plutonium, cerium with four valences was used as the simulacrum for plutonium with tetravalence. Pyrochlore Gd2Zr2O7 as waste forms was pre pared by Gd2O3, ZrO2 and CeO2 powders with high temperature solid-state method. The solid solubility of pyrochlore Gd2Zr2O7 is ranged from 0 to 100% (in mole) dosage. Waste forms were characterized with density, rigidity, phase composition and micro morphology. The results show that density and rigidity HV increase with x, rigidity and the addition of Ce satisfy the relation: HV=661.27273+223.93636x (R2=0.94638). When x=0.0. the waste forms are single pyrochlore structure: when x=0.2. the waste forms transform from pyrochlore into fluorite structure. In the interval 0.2≤x≤ 2.0. the waste forms are single fluorite structure. Microstructure of waste forms is not regular and plate-like. (authors)

  6. Effect of Gd2O3 on the microstructure and thermal properties of nanostructured thermal barrier coatings fabricated by air plasma spraying

    Directory of Open Access Journals (Sweden)

    Yixiong Wang

    2016-08-01

    Full Text Available The nanostructured 4–8 mol% Gd2O3−4.5 mol% Y2O3-ZrO2 (4–8 mol% GdYSZ coatings were developed by the atmospheric plasma spraying technique. The microstructure and thermal properties of plasma-sprayed 4–8 mol% GdYSZ coatings were investigated. The experimental results indicate that typical microstructure of the as-sprayed coatings were consisted of melted zones, nano-zones, splats, nano-pores, high-volume spheroidal pores and micro-cracks. The porosity of the 4, 6 and 8 mol% GdYSZ coatings was about 9.3%, 11.7% and 13.3%, respectively. It was observed that the addition of gadolinia to the nano-YSZ could significantly reduce the thermal conductivity of nano-YSZ. The thermal conductivity of GdYSZ decreased with increasing Gd2O3 addition. And the reduction in thermal conductivity is mainly attributed to the addition of Gd2O3, which results in the increase in oxygen vacancies, lattice distortion and porosity.

  7. Optimization of photoluminescence of Y2O3:Eu and Gd2O3:Eu phosphors synthesized by thermolysis of 2,4-pentanedione complexes

    International Nuclear Information System (INIS)

    Spherical shaped nanoparticles of series Y2-xEuxO3 (x = 0.06, 0.10, 0.20, and 2) and Gd2-xEuxO3 (x = 0.06, 0.10) were prepared by thermolysis of 2,4-pentanedione complexes of Y, Gd, and Eu. The bixbyite phase of Gd2-xEuxO3 samples was formed at 500 deg. C, whereas the thermal decomposition of Y and Eu complexes' mixtures occurred at higher temperatures. Linearity in the concentration dependence on lattice parameter confirmed the formation of solid solutions. The distribution of Eu3+ in Gd2-xEuxO3 was changed with thermal annealing: in the as-prepared sample (x = 0.10) the distribution was preferential at C3i sites while in the annealed samples, Eu3+ were distributed at both C2 and C3i sites. Rietveld refinement of site occupancies as well as emission spectra showed a random distribution of cations in Y2-xEuxO3. The photoluminescence (PL) measurements of the sample showed red emission with the main peak at 614 nm (5D0-7F2). The PL intensity increased with increasing concentration of Eu3+ in both series. Infrared excitation was required to obtain good Raman spectra. The linear dependence of the main Raman peak wavenumber offers a non-destructive method for monitoring the substitution level and its homogeneity at the micron scale.

  8. Effect of monoclonal antibodies on limited proteolysis of native glycoprotein gD of herpes simplex virus type 1

    International Nuclear Information System (INIS)

    We examined the properties of 17 monoclonal antibodies to glycoprotein gD of herpes simplex type 1 (HSV-1) (gD-1) and HSV-2 (gD-2). The antibodies recognized eight separate determinants of gD, based on differences in radioimmuno-precipitation and neutralization assays. The determinants were distributed as follows: three were gD-1 specific, one was gD-2 specific, and four were type common. Several type-specific and type-common determinants appeared to be involved in neutralization. We developed a procedure for examining the effect that binding of monoclonal antibody has on proteolysis of native gD-1 by Staphylococcus aureus protease V8. We showed that several different patterns of protease V8 cleavage were obtained, depending on the monoclonal antibody used. The proteolysis patterns were generally consistent with the immunological groupings. With four groups of antibodies, we found that fragments of gD-1 remained bound to antibody after V8 treatment. A 38,000-dalton fragment remained bound to antibodies in three different groups of monoclonal antibodies. This fragment appeared to contain one type-common and two type-specific determinants. A 12,000-dalton fragment remained bound to antibodies belonging to one type-common group of monoclonal antibodies. Tryptic peptide analysis revealed that the 12,000-dalton fragment represented a portion of the 38,000-dalton fragment and was enriched in a type-common arginine tryptic peptide

  9. Thickness effect of Gd2Zr2O7 buffer layer on performance of YBa2Cu3O7−δ coated conductors

    International Nuclear Information System (INIS)

    Highlights: • Highly biaxial textured Gd2Zr2O7/Y2O3 structure was prepared on NiW tape. • The optimized thickness of Gd2Zr2O7 buffer layer was reduced by over a half. • The deterioration of microstructure on GZO exceeding 120 nm was proved by RHEED. • We obtained Tc and Jc as 92 K and 0.5 MA/cm2 on the YBCO prepared on optimized GZO. - Abstract: Bilayer buffer architecture of Gd2Zr2O7 (GZO)/Y2O3 was prepared on the biaxially textured tape of Ni–5 at% W (NiW) by reactive sputtering deposition technique. The buffer layer of GZO films were deposited with different thicknesses on Y2O3 seeding layer with a given thickness of 20 nm. According to the results of φ-scan, the in-plane FWHMs of GZO films decreased and then reversed with increasing thickness of GZO, which corresponded with the in-plane FWHMs and superconducting properties of YBa2Cu3O7−δ (YBCO) films. Reflection High-Energy Electron Diffraction (RHEED) was carried out to examine the surface texture of GZO films and the deteriorated surface alignment was found for thicker films. The thickness effect of GZO on performance of YBCO is the coupling result of surface texture and blocking effect caused by thickness. With the balance of these two factors, the YBCO/GZO(120 nm)/Y2O3/NiW architecture exhibit relatively high performance with the transition temperature Tc of 92 K, a transition width ΔTc below 1 K, and a critical current density Jc of 0.65 MA/cm2

  10. Self-powdering and nonlinear optical domain structures in ferroelastic β'-Gd2(MoO4)3 crystals formed in glass

    International Nuclear Information System (INIS)

    Ferroelastic β'-Gd2(MoO4)3, (GMO), crystals are formed through the crystallization of 21.25Gd2O3-63.75MoO3-15B2O3 glass (mol%), and two scientific curious phenomena are observed. (1) GMO crystals formed in the crystallization break into small pieces with a triangular prism or pyramid shape having a length of 50-500 μm spontaneously during the crystallizations in the inside of an electric furnace, not during the cooling in air after the crystallization. This phenomenon is called 'self-powdering phenomenon during crystallization' in this paper. (2) Each self-powdered GMO crystal grain shows a periodic domain structure with different refractive indices, and a spatially periodic second harmonic generation (SHG) depending on the domain structure is observed. It is proposed from polarized micro-Raman scattering spectra and the azimuthal dependence of second harmonic intensities that GMO crystals are oriented in each crystal grain and the orientation of (MoO4)2- tetrahedra in GMO crystals changes periodically due to spontaneous strains in ferroelastic GMO crystals. - Graphical abstract: This figure shows the polarized optical photograph at room temperature for a particle (piece) obtained by a heat treatment of the glass at 590 deg. C for 2 h in an electric furnace in air. This particle was obtained through the self-powdering behavior in the crystallization of glass. The periodic domain structure is observed. Ferroelastic β'-Gd2(MoO4)3 crystals are formed in the particle, and second harmonic generations are detected, depending on the domain structure.

  11. Optical and scintillation properties of ce-doped (Gd2Y1)Ga2.7Al2.3O12 single crystal grown by Czochralski method

    Science.gov (United States)

    Wang, Chao; Wu, Yuntao; Ding, Dongzhou; Li, Huanying; Chen, Xiaofeng; Shi, Jian; Ren, Guohao

    2016-06-01

    Multicomponent garnets, due to their excellent light yield and energy resolution, become one of the most promising scintillators used for homeland security and nuclear non-proliferation applications. This work focuses on the optimization of Ce-doped (Gd,Y)3(Ga,Al)5O12 scintillators using a combination strategy of pre-screening and scale-up. Ce-doped GdxY1-xGayAl5-yO12 (x=1, 2 and y=2, 2.2, 2.5, 2.7, 3) polycrystalline powders were prepared by high-temperature solid state reaction method. The desired garnet phase in all the samples was confirmed using X-ray diffraction measurement. By comparing the radioluminescence intensity, the highest scintillation efficiency was achieved at a component of Gd2Y1Ga2.7Al2.3O12:Ce powders. A (Gd2Y1)Ga2.7Al2.3O12 doped with 1% Ce single crystal with dimensions of Ø35×40 mm was grown by Czochralski method using a oriented seed. Luminescence and scintillation properties were measured. An optical transmittance of 84% was achieved in the concerned wavelength from 500 to 800 nm. Its 5d-4f emission of Ce3+ is at 530 nm. The light yield of a Ce1%: Gd2Y1Ga2.7Al2.3O12 single crystal slab at a size of 5×5×1 mm3 can reach about 65,000±3000 Ph/MeV along with two decay components of 94 and 615 ns under 137Cs source irradiation.

  12. Copper-deficiency in Ln2-xCexCuO4 (Ln=Nd, Gd) crystals and oxygen disorder in Gd2CuO4 crystals

    OpenAIRE

    Galez, Ph.; Collin, G.

    1990-01-01

    The structure of seven Nd2-xCexCuO4 (x=0 and x=0.18) and Gd2CuO4 single crystals is determined by means of X-ray diffraction. All crystals have the Nd2CuO 4 tetragonal T' structure, space group I4/mmm (139). The copper site is found deficient (3 - 6%) in six crystals whereas both oxygen sites (within the CO2 planes O(1) and between rare earth layers 0(2)) remain fully occupied within standard deviation. The vibration ellipsoids of Nd, Cu and O(2) appear to be more ellongated in the c directio...

  13. Synthesis and Characterization of Hollow Magnetic Alloy (GdNi2, Co5Gd Nanospheres Coated with Gd2O3

    Directory of Open Access Journals (Sweden)

    Wang Li

    2014-01-01

    Full Text Available Uniform magnetic hollow nanospheres (GdNi2, Co5Gd coated with Gd2O3 have been successfully prepared on a large scale via a urea-based homogeneous precipitation method using silica (SiO2 spheres as sacrificed templates, followed by subsequent heat treatment. Nitrogen sorption measurements and scanning electron microscope reveal that these hollow-structured magnetic nanospheres have the mesoporous shells that are composed of a large amount of uniform nanoparticles. After reduction treatment, these nanoparticles exhibit superparamagnetism that might have potential applications in medicine. Furthermore, the developed synthesis route may provide an important guidance for the preparation of other multifunctional hollow spherical materials.

  14. Crystal-field interaction and single-ion anisotropy in spin-frustrated antiferromagnet pyrochlore Gd2Ti2O7

    International Nuclear Information System (INIS)

    The geometrically frustrated antiferromagnet Gd2Ti2O7 is an easy-planer anisotropic system in which single ion anisotropy mainly arises due to the considerable admixture of higher Russel-Saunders terms of Gd3+ ion to its ground term 8S. The g-value of the ground CF doublet becomes anisotropic, g parallel = 1.99, g perpendicular = 7.97, instead of the free-ion isotropic value 2. The ground multiplet 8S7/2 splits into 4 doublets with total splitting ∼16 K, thus exhibiting its characteristic specific heat feature below 5 K. (author)

  15. Effect of substitutions on 3d magnetism in Gd2Fe14-xMxC compounds, with M=Ni, Si, Cu or V

    International Nuclear Information System (INIS)

    Results of magnetic measurements and 57Fe Moessbauer spectroscopy performed on Gd2Fe14-xMxC compounds, with M=Ni, Si, Cu or V are presented. As M is substituted for Fe, the six crystallographically inequivalent iron sites split into seven inequivalent sites for M=Si, Cu, V, or eight for M=Ni. The analysis of the hyperfine fields and relative intensities supports a preferential distribution of the substitutional elements on the Fe lattice sites. The effects of the substitutional elements on Curie temperatures and anisotropy fields as well as on Fe hyperfine parameters are discussed on the grounds of the preferential Fe site occupancy. (orig.)

  16. Terbium-doped gadolinium oxysulfide (Gd2O2S:Tb) scintillation-based polymer optical fibre sensor for real time monitoring of radiation dose in oncology

    Science.gov (United States)

    Lewis, E.; O'Keeffe, S.; Grattan, M.; Hounsell, A.; McCarthy, D.; Woulfe, P.; Cronin, J.; Mihai, L.; Sporea, D.; Santhanam, A.; Agazaryan, N.

    2014-05-01

    A PMMA based plastic optical fibre sensor for use in real time radiotherapy dosimetry is presented. The optical fibre tip is coated with a scintillation material, terbium-doped gadolinium oxysulfide (Gd2O2S:Tb), which fluoresces when exposed to ionising radiation (X-Ray). The emitted visible light signal penetrates the sensor optical fibre and propagates along the transmitting fibre at the end of which it is remotely monitored using a fluorescence spectrometer. The results demonstrate good repeatability, with a maximum percentage error of 0.5% and the response is independent of dose rate.

  17. Spectroscopic and magnetic behaviour of xGd2O3 (1 - x)(Bi2O3·PbO) glasses

    International Nuclear Information System (INIS)

    Glasses of the xGd2O3 (1 - x)(Bi2O3·PbO) system (0 ≤ x ≤ 0.15) were obtained and studied by IR spectroscopy, electron paramagnetic resonance (EPR), magnetic susceptibility and density measurements. IR data show that increasing the amount of gadolinium ions in the studied glasses produces structural modifications of the host vitreous matrix consisting in a conversion of the [BiO3] into [BiO6] structural units. EPR and magnetic susceptibility data show that for low gadolinium oxide content of the samples, x ≤ 0.05, the Gd3+ ions are randomly distributed in the host glass matrix and are present only as isolated species. For higher gadolinium oxide contents of the samples, x > 0.05, the Gd3+ ions appear as both isolated and antiferromagnetically coupled species. IR and density measurements support the assumption of the network modifier role played by the gadolinium ions in the xGd2O3 (1 - x)(Bi2O3·PbO) glasses. EPR data show an unusual absorption line for the Gd3+ ions in glass matrices. This absorption line is due to Gd3+ ions that replace Bi3+ and Pb4+ ions from the host glass matrix and play the network former role in the studied glasses

  18. Synthesis and characterization of (3-Aminopropyl)trimethoxy-silane (APTMS) functionalized Gd2O3:Eu3+ red phosphor with enhanced quantum yield

    Science.gov (United States)

    Jain, Akhil; Hirata, G. A.; Farías, M. H.; Castillón, F. F.

    2016-02-01

    We report the surface modification of nanocrystalline Gd2O3:Eu3+ phosphor by (3-Aminopropyl)trimethoxysilane (APTMS). The nanoparticles were first coated with silica using the Stöber process, and then annealed at 650 °C for 2 h. Afterwards, APTMS was functionalized onto the silica layer to obtain Gd2O3:Eu3+ nanoparticles bearing amine groups on the surface. The effect of silica coating, and the subsequent annealing process on the crystallization of the nanophosphor were analyzed by x-ray diffraction (XRD). High-resolution transmission electron microscopy (HR-TEM) confirmed the presence of a silica layer of ∼45 nm thickness. X-ray photoelectron (XPS) and Fourier transform infrared (FTIR) spectroscopy confirmed the presence of silica and the amine groups. Photoluminescence (PL) analysis demonstrated an increased emission after functionalization of nanoparticles. Absolute quantum yield (QY) measurements revealed an 18% enhancement in QY in functionalized nanoparticles compared with unmodified nanoparticles, which is of great importance for their biomedical applications.

  19. A simple polyol-free synthesis route to Gd2O3 nanoparticles for MRI applications: an experimental and theoretical study

    International Nuclear Information System (INIS)

    Chelated gadolinium ions, e.g., Gd-DTPA, are today used clinically as contrast agents for magnetic resonance imaging (MRI). An attractive alternative contrast agent is composed of gadolinium oxide nanoparticles as they have shown to provide enhanced contrast and, in principle, more straightforward molecular capping possibilities. In this study, we report a new, simple, and polyol-free way of synthesizing 4–5-nm-sized Gd2O3 nanoparticles at room temperature, with high stability and water solubility. The nanoparticles induce high-proton relaxivity compared to Gd-DTPA showing r1 and r2 values almost as high as those for free Gd3+ ions in water. The Gd2O3 nanoparticles are capped with acetate and carbonate groups, as shown with infrared spectroscopy, near-edge X-ray absorption spectroscopy, X-ray photoelectron spectroscopy and combined thermogravimetric and mass spectroscopy analysis. Interpretation of infrared spectroscopy data is corroborated by extensive quantum chemical calculations. This nanomaterial is easily prepared and has promising properties to function as a core in a future contrast agent for MRI.

  20. Self-powdering and nonlinear optical domain structures in ferroelastic β‧-Gd2(MoO4)3 crystals formed in glass

    Science.gov (United States)

    Tsukada, Y.; Honma, T.; Komatsu, T.

    2009-08-01

    Ferroelastic β'-Gd 2(MoO 4) 3, (GMO), crystals are formed through the crystallization of 21.25Gd 2O 3-63.75MoO 3-15B 2O 3 glass (mol%), and two scientific curious phenomena are observed. (1) GMO crystals formed in the crystallization break into small pieces with a triangular prism or pyramid shape having a length of 50-500 μm spontaneously during the crystallizations in the inside of an electric furnace, not during the cooling in air after the crystallization. This phenomenon is called "self-powdering phenomenon during crystallization" in this paper. (2) Each self-powdered GMO crystal grain shows a periodic domain structure with different refractive indices, and a spatially periodic second harmonic generation (SHG) depending on the domain structure is observed. It is proposed from polarized micro-Raman scattering spectra and the azimuthal dependence of second harmonic intensities that GMO crystals are oriented in each crystal grain and the orientation of (MoO 4) 2- tetrahedra in GMO crystals changes periodically due to spontaneous strains in ferroelastic GMO crystals.

  1. GD2-specific CAR T Cells Undergo Potent Activation and Deletion Following Antigen Encounter but can be Protected From Activation-induced Cell Death by PD-1 Blockade.

    Science.gov (United States)

    Gargett, Tessa; Yu, Wenbo; Dotti, Gianpietro; Yvon, Eric S; Christo, Susan N; Hayball, John D; Lewis, Ian D; Brenner, Malcolm K; Brown, Michael P

    2016-06-01

    Chimeric antigen receptor (CAR) T cells have shown great promise in the treatment of hematologic malignancies but more variable results in the treatment of solid tumors and the persistence and expansion of CAR T cells within patients has been identified as a key correlate of antitumor efficacy. Lack of immunological "space", functional exhaustion, and deletion have all been proposed as mechanisms that hamper CAR T-cell persistence. Here we describe the events following activation of third-generation CAR T cells specific for GD2. CAR T cells had highly potent immediate effector functions without evidence of functional exhaustion in vitro, although reduced cytokine production reversible by PD-1 blockade was observed after longer-term culture. Significant activation-induced cell death (AICD) of CAR T cells was observed after repeated antigen stimulation, and PD-1 blockade enhanced both CAR T-cell survival and promoted killing of PD-L1(+) tumor cell lines. Finally, we assessed CAR T-cell persistence in patients enrolled in the CARPETS phase 1 clinical trial of GD2-specific CAR T cells in the treatment of metastatic melanoma. Together, these data suggest that deletion also occurs in vivo and that PD-1-targeted combination therapy approaches may be useful to augment CAR T-cell efficacy and persistence in patients. PMID:27019998

  2. Fabrication and evaluation of a Gd2O2S:Tb phosphor screen film for development of a CMOS-based X-ray imaging detector

    Science.gov (United States)

    Park, Ji Koon; Choi, Su Rim; Noh, Si Cheol; Jung, Bong Jae; Choi, Il Hong; Kang, Sang Sik

    2014-08-01

    In this study, Gd2O2S:Tb phosphor screen films were fabricated by using a special particle-inbinder sedimentation method. The phosphor particles used in this study were manufactured in two sizes, 2.5- μm and 5- μm. To evaluate luminescence efficiency and the spatial resolution according to the thickness, we fabricated screen films with thicknesses of 120, 150, 170, and 210- μm. The spatial resolution of the fabricated films was assessed by using an edge method to measure the modulation transfer function (MTF). From the experimental results, the spatial resolution of the mammography exposures (low-energy X-ray quality) was better than that of dental radiography (high-energy X-ray quality). Also, with the same film thickness, the screen with 2.5- μm particles had better resolution than the screen with 5.0- μm particles, but it showed about 20% lower resolution than a commercial Gd2O2S:Tb screen. In the evaluation of the results for the dependence of the spatial resolution on the film's thickness, the 120- μm-thick screen showed the highest resolution, which was similar to that of a commercial screen.

  3. Fabrication of Gd2O2S:Tb based phosphor films coupled with photodetectors for x-ray imaging applications

    International Nuclear Information System (INIS)

    The Gd2O2S:Tb based phosphor coupled with photodetectors has been widely used in digital x-ray imaging applications. The key issues associated with phosphor film are x-ray absorption and conversion efficiency, spatial resolution, deposition uniformity, and integration with the imaging array. In this article we report on experimental studies of the phosphor film synthesis, deposition, and characterization. A composite material, consisting of Gd2O2S:Tb, polyvinyl alcohol, and water coupled with a small amount of additives, is synthesized as a phosphor paste. The parameters controlling film quality include individual component concentrations, grain sizes of phosphor, and viscosity of the solution. A sedimentation technique is used to deposit the phosphor directly on the imaging array. A number of phosphor films have been synthesized with the particle sizes ranging from 2.5 to 25 μm and film thickness ranging from 85 to 1100 μm, and measurement results of x-ray conversion efficiency and spatial resolution in terms of modulation transfer function are presented. A new technology for phosphor patterning is proposed to seamlessly integrate the phosphor with the photodetectors by using negative photoresist SU-8 and preliminary results are presented

  4. Low voltage operated, sol–gel derived oxide thin film transistor based on high-k Gd2O3 gate dielectric

    International Nuclear Information System (INIS)

    Low power-driven oxide thin film transistor (TFT) with a high-k gate dielectric is fabricated by a simple solution process. Sol–gel derived Gd2O3 film exhibits the dielectric constant in the range of 9–14 with breakdown field as high as 3.5 MV cm−1. Zn–In–Sn–O based TFTs combined with a corresponding film demonstrate the readiness of solution processed high-k film as gate insulators. The resultant device exhibits the enhanced performance with the field-effect mobility of ∼1.9 cm2 V−1 s−1, which is improved by a factor of 4.5 comparing with the conventional TFT based on a SiO2 insulator, and the exceptionally low operating voltage of 6 V. - Highlights: ► Solution processed high-k Gd2O3 gate insulator for oxide thin film transistors (TFTs). ► Low voltage-operated TFTs with enhanced switching property can be obtained. ► Applicable to the promising electronic materials for printing-based TFTs

  5. Host factors determine anti-GM1 response following oral challenge of chickens with Guillain-Barre syndrome derived Campylobacter jejuni strain GB11.

    Directory of Open Access Journals (Sweden)

    C Wim Ang

    Full Text Available BACKGROUND: Anti-ganglioside antibodies with a pathogenic potential are present in C. jejuni-associated Guillain-Barré syndrome (GBS patients and are probably induced by molecular mimicry. Immunization studies in rabbits and mice have demonstrated that these anti-ganglioside antibodies can be induced using purified lipo-oligosaccharides (LOS from C. jejuni in a strong adjuvant. METHODOLOGY/PRINCIPAL FINDINGS: To investigate whether natural colonization of chickens with a ganglioside-mimicking C. jejuni strain induces an anti-ganglioside response, and to investigate the diversity in anti-ganglioside response between and within genetically different chicken lines, we orally challenged chickens with different C. jejuni strains. Oral challenge of chickens with a C. jejuni strain from a GBS patient, containing a LOS that mimics ganglioside GM1, induced specific IgM and IgG anti-LOS and anti-GM1 antibodies. Inoculation of chickens with the Penner HS:3 serostrain, without a GM1-like structure, induced anti-LOS but no anti-ganglioside antibodies. We observed different patterns of anti-LOS/ganglioside response between and within the five strains of chickens. CONCLUSIONS: Natural infection of chickens with C. jejuni induces anti-ganglioside antibodies. The production of antibodies is governed by both microbial and host factors.

  6. Ce3+掺杂SiO2-Al2O3-Gd2O3玻璃的闪烁性能∗%Scintillation properties of Ce3+ doped SiO2-Al2O3-Gd2O3 glass

    Institute of Scientific and Technical Information of China (English)

    刘力挽; 周秦岭; 邵冲云; 张瑜; 胡丽丽; 杨秋红; 陈丹平

    2015-01-01

    Scintillation glass is an attractive material due to its many advantages including low-cost and easy-manufacturing compared with single crystal. However the low density of glass scintillator restricts its applications. The introduction of heavy components such as PbO and Bi2O3 allows the density of the glass to be easily increased to more than 6.0 g/cm3 which is desirable for most applications. However, it is usually accompanied with a dramatic decrease in the luminescence response of Ce3+ions. Although Gd2O3 based glass has a relatively high light yield, it is far below the high silica glass. In order to explain why the luminescent efficiency of Ce3+ doped glass with low density is high while that with high density is low, a glass-forming region of SiO2-Al2O3-Gd2O3 ternary system is achieved by high-temperature melt-quenching method. Ce3+doped SiO2-Al2O3-Gd2O3 and SiO2-Al2O3-Gd2O3-Ln2O3 (Ln=Y, La, Lu) scintillation glasses are prepared at reducing atmosphere. Their optical and scintillation properties are investigated. The results show that the content of Gd2O3 can reach as high as 30%mol without phase separation. In addition, the UV cut-off position is red-shifted, PL intensity decreases and decay time reduces from 70 to 37.6 ns with increasing the Gd2O3 concentration. After Lu2O3, La2O3, Y2O3 are added in the glass, the UV cut-off position is red-shifted and PL intensity decreases. Moreover the UV cut-off position is in the order of La>Y>Lu and the decay time is in the order of La With the UV cut-off position red-shifted, the bandgap of glass becomes narrow, resulting in the 5 d level of Ce3+ions gradually approaching to the conduction band and the 5 d electrons easily combining with the holes in the glass through the conduction band. Namely, charge transferring quenching occurs. This is the reason why the PL intensity and decay time both decrease. It can also explain why the luminescent efficiency of Ce3+ doped glass with low density is high while that with

  7. Scintillation properties of Ce3+ doped SiO2-Al2O3-Gd2O3 glass%Ce3+掺杂SiO2-Al2O3-Gd2O3玻璃的闪烁性能∗

    Institute of Scientific and Technical Information of China (English)

    刘力挽; 周秦岭; 邵冲云; 张瑜; 胡丽丽; 杨秋红; 陈丹平

    2015-01-01

    Scintillation glass is an attractive material due to its many advantages including low-cost and easy-manufacturing compared with single crystal. However the low density of glass scintillator restricts its applications. The introduction of heavy components such as PbO and Bi2O3 allows the density of the glass to be easily increased to more than 6.0 g/cm3 which is desirable for most applications. However, it is usually accompanied with a dramatic decrease in the luminescence response of Ce3+ions. Although Gd2O3 based glass has a relatively high light yield, it is far below the high silica glass. In order to explain why the luminescent efficiency of Ce3+ doped glass with low density is high while that with high density is low, a glass-forming region of SiO2-Al2O3-Gd2O3 ternary system is achieved by high-temperature melt-quenching method. Ce3+doped SiO2-Al2O3-Gd2O3 and SiO2-Al2O3-Gd2O3-Ln2O3 (Ln=Y, La, Lu) scintillation glasses are prepared at reducing atmosphere. Their optical and scintillation properties are investigated. The results show that the content of Gd2O3 can reach as high as 30%mol without phase separation. In addition, the UV cut-off position is red-shifted, PL intensity decreases and decay time reduces from 70 to 37.6 ns with increasing the Gd2O3 concentration. After Lu2O3, La2O3, Y2O3 are added in the glass, the UV cut-off position is red-shifted and PL intensity decreases. Moreover the UV cut-off position is in the order of La>Y>Lu and the decay time is in the order of La With the UV cut-off position red-shifted, the bandgap of glass becomes narrow, resulting in the 5 d level of Ce3+ions gradually approaching to the conduction band and the 5 d electrons easily combining with the holes in the glass through the conduction band. Namely, charge transferring quenching occurs. This is the reason why the PL intensity and decay time both decrease. It can also explain why the luminescent efficiency of Ce3+ doped glass with low density is high while that with

  8. Antithyroid microsomal antibody

    Science.gov (United States)

    Thyroid antimicrosomal antibody; Antimicrosomal antibody; Microsomal antibody; Thyroid peroxidase antibody; TPOAb ... Granulomatous thyroiditis Hashimoto thyroiditis High levels of these antibodies have also been linked to an increased risk ...

  9. Autoantibodies against ganglioside GM3 are associated with narcolepsy-cataplexy developing after Pandemrix vaccination against 2009 pandemic H1N1 type influenza virus.

    Science.gov (United States)

    Saariaho, Anna-Helena; Vuorela, Arja; Freitag, Tobias L; Pizza, Fabio; Plazzi, Giuseppe; Partinen, Markku; Vaarala, Outi; Meri, Seppo

    2015-09-01

    Following the mass vaccinations against pandemic influenza A/H1N1 virus in 2009, a sudden increase in juvenile onset narcolepsy with cataplexy (NC) was detected in several European countries where AS03-adjuvanted Pandemrix vaccine had been used. NC is a chronic neurological disorder characterized by excessive daytime sleepiness and cataplexy. In human NC, the hypocretin-producing neurons in the hypothalamus or the hypocretin signaling pathway are destroyed by an autoimmune reaction. Both genetic (e.g. HLA-DQB1*0602) and environmental risk factors (e.g. Pandemrix) contribute to the disease development, but the underlying and the mediating immunological mechanisms are largely unknown. Influenza virus hemagglutinin is known to bind gangliosides, which serve as host cell virus receptors. Anti-ganglioside antibodies have previously been linked to various neurological disorders, like the Guillain-Barré syndrome which may develop after infection or vaccination. Because of these links we screened sera of NC patients and controls for IgG anti-ganglioside antibodies against 11 human brain gangliosides (GM1, GM2, GM3, GM4, GD1a, GD1b, GD2, GD3, GT1a, GT1b, GQ1b) and a sulfatide by using a line blot assay. Samples from 173 children and adolescents were analyzed: 48 with Pandemrix-associated NC, 20 with NC without Pandemrix association, 57 Pandemrix-vaccinated and 48 unvaccinated healthy children. We found that patients with Pandemrix-associated NC had more frequently (14.6%) anti-GM3 antibodies than vaccinated healthy controls (3.5%) (P = 0.047). Anti-GM3 antibodies were significantly associated with HLA-DQB1*0602 (P = 0.016) both in vaccinated NC patients and controls. In general, anti-ganglioside antibodies were more frequent in vaccinated (18.1%) than in unvaccinated (7.3%) individuals (P = 0.035). Our data suggest that autoimmunity against GM3 is a feature of Pandemrix-associated NC and that autoantibodies against gangliosides were induced by Pandemrix vaccination. PMID

  10. Effect of Single-ion Anisotropy on the Low-Temperature Spin Properties of Frustrated Gd2Hf2O7

    Science.gov (United States)

    Biswas, Aksar Ali; Jana, Yatramohan

    2011-06-01

    Considerable single-ion crystal-field (CF) anisotropy of easy-plane type is found in the frustrated pyrochlore antiferromagnet Gd2Hf2O7 (GdH) in the ground multiplet 8S7/2. It arises due to admixture of higher Russell-Saunders terms to the ground term 8S and D3d CF at Gd-site. The 8S7/2 splits into 4 doublets with total CF splitting 9.9 K in GdH. On the basis of CF calculation and phenomenological parametrical fitting, it is shown that magnetic specific heat Cmag follows a conventional T3 behavior down to 0.39 K which may be attributable to gapless magnon excitation.

  11. Optical, scintillation properties and defect study of Gd2Si2O7:Ce single crystal grown by floating zone method

    International Nuclear Information System (INIS)

    Single crystal of Gd2Si2O7:Ce (GPS) presenting attractive scintillation performance was grown by the floating zone method. The vacuum ultra-violet (VUV) excitation and emission, ultra-violet (UV) excitation and emission spectra and fluorescent decay time at 77 K and RT were measured and discussed. Relative energy levels of 5d sublevels of Ce3+ in GPS:Ce are detected by the VUV excitation spectrum. The UV emission curve of GPS:1%Ce peaks around 382 nm at 77 K and moves towards longer wavelength direction as temperature increases. Thermally stimulated luminescence (TSL) was employed to investigate the defects in GPS:1%Ce. Energy depths of two traps detected in GPS:1%Ce are 0.64 and 1.00 eV

  12. Magnetocaloric effect in gadolinium-oxalate framework Gd2(C2O4)3(H2O)6⋅(0⋅6H2O)

    International Nuclear Information System (INIS)

    Magnetic refrigerants incorporating Gd3+ ions and light organic ligands offer a good balance between isolation of the magnetic centers and their density. We synthesized the framework material Gd2(C2O4)3(H2O)6⋅0.6H2O by a hydrothermal route and characterized its structure. The honeycomb lattice of Gd3+ ions interlinked by oxalate ligands in the (a,c) plane ensures their decoupling in terms of magnetic exchange interactions. This is corroborated by magnetic measurements indicating negligible interactions between the Gd3+ ions in this material. The magnetocaloric effect was evaluated from isothermal magnetization measurements. The maximum entropy change −ΔSMmax reaches 75.9 mJ cm−3 K−1 (around 2 K) for a moderate field change (2 T)

  13. Fabrication and characterization of pixelated Gd2O2S:Tb scintillator screens for digital X-ray imaging applications

    International Nuclear Information System (INIS)

    X-ray imaging detectors in combination with scintillator screens have been widely used in digital X-ray imaging applications. Gd2O2S:Tb was used as scintillation material for pixelated scintillator screens based on silicon substrates (wafer) with a micropore array of various dimensions fabricated using the photolithography and deep reactive ion etching (DRIE) process. The relative light output and the modulation transfer function (MTF) of each fabricated scintillator screen were measured by a cooled CCD and compared with those of Lanex screens. The spatial resolution of our scintillator screens was higher but their light outputs were lower than those of Lanex screen probably due to the loss of light at the wall surfaces. Therefore further treatment of the wall surface, such as reflective coating, seems necessary to compensate the light loss.

  14. Optical, scintillation properties and defect study of Gd2Si2O7:Ce single crystal grown by floating zone method

    Science.gov (United States)

    Feng, He; Xu, Wusheng; Ren, Guohao; Yang, Qiuhong; Xie, Jianjun; Xu, Jun; Xu, Jiayue

    2013-02-01

    Single crystal of Gd2Si2O7:Ce (GPS) presenting attractive scintillation performance was grown by the floating zone method. The vacuum ultra-violet (VUV) excitation and emission, ultra-violet (UV) excitation and emission spectra and fluorescent decay time at 77 K and RT were measured and discussed. Relative energy levels of 5d sublevels of Ce3+ in GPS:Ce are detected by the VUV excitation spectrum. The UV emission curve of GPS:1%Ce peaks around 382 nm at 77 K and moves towards longer wavelength direction as temperature increases. Thermally stimulated luminescence (TSL) was employed to investigate the defects in GPS:1%Ce. Energy depths of two traps detected in GPS:1%Ce are 0.64 and 1.00 eV.

  15. Crystal growth and optical properties of Ce:(La,Gd)2Ge2O7 grown by the floating zone method

    Science.gov (United States)

    Kurosawa, Shunsuke; Shishido, Toetsu; Sugawara, Takamasa; Yubuta, Kunio; Jan, Pejchal; Suzuki, Akira; Yokota, Yuui; Shoji, Yasuhiro; Kamada, Kei; Yoshikawa, Akira

    2014-05-01

    Some pyrosilicate scintillators such as Ce:Gd2Si2O7 and Ce:Lu2Si2O7 have a good light output, and especially Ce:(Gd,La)2Si2O7 has an excellent light output of over 36,000 ph/MeV. In order to search novel scintilators, we have developed a pyrogermanate-based scintillation material (Ce0.01,Gd0.90,La0.09)2Ge2O7 using the floating zone method. Although the light output was decreased due to quenching, 5d-4f transition of Ce3+ was observed around 480 nm in photo- and radio-luminescence spectra. This emission wavelength was longer than that of (Ce0.01,Gd0.90,La0.09)2Si2O7 with an emission wavelength of 390 nm.

  16. Interrelated emission and spin-spin relaxation feature mediated by VO+ defects in Gd2O3 nanorods subjected to swift ion impact

    Science.gov (United States)

    Hazarika, Samiran; Mohanta, Dambarudhar

    2016-04-01

    We report on the manifestation and interconnected photoluminescence and electron paramagnetic resonance responses in gadolinium oxide (Gd2O3) nanorods subjected to 80 MeV carbon ion irradiation. On increasing the irradiation fluence between 1 × 1011 and 3 × 1012 ions/cm2, the emission associated with neutral oxygen vacancies (VOx), positioned at ~350 nm, undergoes a steady increase compared to that associated with singly charged vacancies (VO+), located at ~414 nm. The enhancement of spin-spin relaxation time (τss) is ascribed to a substantial changeover from VO+ to VOx defects with irradiation, the former being recognized as the major contributor to paramagnetic centres. Interconnected luminescence and spin-spin relaxation could provide insight for making advanced nanophosphors and spin valve elements.

  17. Pumping-route-dependent concentration quenching and temperature effect of green up- and down-conversion luminescence in Er3+/Yb3+ co-doped Gd2(WO4)3 phosphors

    International Nuclear Information System (INIS)

    Graphical abstract: A comparative study on the concentration quenching behaviors of green down- and up-conversion emissions was carried out for the first time, and the different concentration quenching mechanisms were analyzed. Secondly, the thermal effect induced by 980 nm LD irradiation was investigated, it was observed that the equilibrium temperature of Gd2(WO4)3:Er3+/Yb3+ sample was decided by both the excitation power and Er3+ doping concentration. Highlights: ► Gd2(WO4)3:Er/Yb phosphors were prepared via a co-precipitation reaction. ► Morphology and structure of the phosphors were characterized by XRD and SEM. ► Concentration quenching mechanisms for down and up emissions were studied. ► Thermal effect induced by laser irradiation was studied via temperature sensing tech. - Abstract: Gd2(WO4)3 phosphors with various Er3+ concentrations and fixed Yb3+ concentration were synthesized via a co-precipitation method, and their crystal structure and morphology were characterized by using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The concentration quenching behaviors of green up- and down-conversion emissions of Er3+ were analyzed, and it was confirmed that the difference between quenching concentration for up- and down-conversion emissions resulted from the different population routes. The temperature sensing properties of the Gd2(WO4)3:Er3+/Yb3+ phosphors were studied, and it was found that the Er3+ doping concentration slightly affected the sensitivity, and Gd2(WO4)3:Er3+/Yb3+ phosphors could be used in a broad temperature region for detecting temperature. Finally, the thermal effect induced by 980 nm LD irradiation was investigated, it was observed that the equilibrium temperature of Gd2(WO4)3:Er3+/Yb3+ sample was decided by both the excitation power and Er3+ doping concentration

  18. Preparation and studies of Eu3+ and Tb3+ co-doped Gd2O3 and Y2O3 sol-gel scintillating films

    International Nuclear Information System (INIS)

    Eu3+ (2.5 at.%) and Tb3+ (0.005-0.01 at.%) co-doped gadolinium and yttrium oxide (Gd2O3 and Y2O3) powders and films have been prepared using the sol-gel process. High density and optical quality thin films were prepared with the dip-coating technique. Gadolinium (III) 2,4-pentadionate and yttrium (III) 2,4-pentadionate were used as precursors, and europium and terbium in their nitrate forms were used as doping agents. Chemical and structural analyses (infrared spectroscopy, X-ray diffraction and high-resolution transmission electron microscopy) were conducted on both sol-gel precursor powders and dip-coated films. The morphology of thin films heat-treated at 700 oC was studied by means of atomic force microscopy. It was shown that the highly dense and very smooth films had a root mean roughness (RMS) of 2 nm ± 0.2 (A = 0.0075 Tb3+) and 24 nm ± 3.0 (B = 0.01 Tb3+). After treatment at 700 oC, the crystallized films were in the cubic phase and presented a polycrystalline structure made up of randomly oriented crystallites with grain sizes varying from 20 to 60 nm. The X-ray induced emission spectra of Eu3+- and Tb3+-doped Gd2O3 and Y2O3 powders showed that Tb3+ contents of 0.005, 0.0075 and 0.01 at.% affected their optical properties. Lower Tb3+ concentrations (down to 0.005 at.%) in both systems enhanced the light yield.

  19. Investigation of luminescence and laser transition of Dy3+ in Li2O-Gd2O3-Bi2O3-B2O3 glasses

    Science.gov (United States)

    Zaman, F.; Kaewkhao, J.; Srisittipokakun, N.; Wantana, N.; Kim, H. J.; Rooh, G.

    2016-05-01

    The aim of this study is to develop Li2O-Gd2O3-Bi2O3-B2O3 glass doped with different concentration of Dy3+ ions by melt quenching technique for different applications in photonics and laser devices. From the experimental oscillator strength (fexp) of the absorption spectra the JO intensity parameters (Ω λ = 2, 4, 6) have been calculated, and by using these JO intensity parameters various radiative parameters were calculated. By using JO theory the radiative transition probability (AR), radiative lifetime (τR) and branching ratio (βR) for Dy3+ ion have been found. A decrease in lifetimes of the prepared glass by increasing concentration of Dy3+ is because of the energy transfer through cross relaxation and resonant energy transfer channels in the present glass matrix. Using experimental and calculated lifetimes, the quantum efficiency (η) and non-radiative relaxation rates (WNR) of 4F9/2 excited state have been calculated. From emission spectra, effective bandwidths (Δλeff) and emission stimulated emission cross section σ (λp) were found for 4F9/2 → 6HJ (J = 15/2, 13/2, 11/2 and 9/2). Chromaticity results revealed that the CCT values of the LGBiBDy glass samples are in between to those of day light and commercial white light LED sources. Further investigations are under way for the optimization of dopant concentration in the Li2O-Gd2O3-Bi2O3-B2O3 glass.

  20. Y2O3与Gd2O3共掺杂SrZrO3热障涂层材料的热物理性能%Thermophysical Properties of Y2O3 and Gd2O3 Co-doped SrZrO3 Thermal Barrier Coating Material

    Institute of Scientific and Technical Information of China (English)

    马文; 宋峰雨; 董红英; 许萍; 伦文山; 郑学斌

    2012-01-01

    Y2O3 (5mol%) and Gd2O3 (5mol%) co-doped SiZrO3 (Sr(Zr0.9Y0.05Gd0.05)O2.95, SZYG) was synthesized by solid state reaction method. The phase stability of the SZYG powder synthesized at high temperature of 1450°C for a long period and at temperature range of 200-1400°C was characterized by XRD and DSC, respectively. The coefficients of thermal expansion (CTEs) of bulk SZYG recorded by a high-temperature dilatometer show that the phase transitions of SrZrO3 is suppressed remarkably by co-doping Y2O3 and Gd2O3. The thermal conductivity of bulk SZYG at 10001 is 1.36 W/(mK), which is 35% lower than that of bulk SrZrO3 and 8YSZ. The good chemical compatibility of SZYG with 8YSZ and A12O3, is detected after heat-treatment at 1250°C for 24 h.%采用固相反应法合成了5mol% Y2O3与5mol% Gd2O3共掺杂SrZrO3(Sr(Zr0.9Y0.05Gd0.05)O2.95,SZYG)粉末.采用X射线衍射(XRD)和差示扫描量热仪(DSC)分别研究了SZYG粉末在1450℃长期热处理后以及200~1400℃范围内的相稳定性.采用高温热膨胀仪测量了SZYG块材的热膨胀系数,结果表明:通过Y2O3与Gd2O3共掺杂改性可以明显抑制SrZrO3的相转变.在1000℃下SZYG块材的热导率是~1.36 W/(m.K),与SrZrO3和8YSZ块材相比降低~35% SZYG分别与8YSZ和Al2O3在1250℃热处理24h表现出很好的化学相容性.

  1. Microstructure and super high strength of cast Mg-8.5Gd-2.3Y-1.8Ag-0.4Zr alloy

    International Nuclear Information System (INIS)

    Research highlights: → A super high strength Mg-8.5Gd-2.3Y-1.8Ag-0.4Zr alloy with good ductility is developed using ordinary casting technique and heat treatment. After optimum heat treatment, i.e. solution treatment at 500 deg. C for 10 h and subsequently ageing at 200 deg. C for 32 h, the room temperature TYS, UTS and elongation of the cast-T6 alloy reaches 268 MPa, 403 MPa and 4.9% respectively. → Ag additions produce improved solid solution strengthening and remarkably enhance the age hardening response. The enhanced age hardening response can be attributed to the basal nano-scale plate precipitates, which are not observed in the Ag-free alloy, as well as the refinement of β' phase. The co-precipitation strengthening produced by β' phase and the plate-like precipitate is the largest contributor to the strength of the cast-T6 alloy. → In the paper, we reported a novel super high strength cast magnesium alloy with notable lower rare earth contents and substantially improved ductility. The alloy exhibits a record high ultimate tensile strength of more than 400 MPa with a sufficient elongation of 4.9% at room temperature. Such excellent combination of high strength and ductility is rarely reported in ordinary cast Mg alloys and would be of great significance for the applications of Mg alloys. - Abstract: A super high strength Mg-8.5Gd-2.3Y-1.8Ag-0.4Zr alloy with good ductility was developed using an ordinary casting technique and heat treatment. After the solution treatment at 500 deg. C for 10 h and subsequent ageing at 200 deg. C for 32 h, the room temperature TYS, UTS and elongation of the cast-T6 alloy was 268 MPa, 403 MPa and 4.9% respectively. Ag additions produce improved solid solution strengthening and enhanced the age hardening response. The enhanced age hardening response was attributed to the basal nano-scale plate precipitates, which were not observed in the Ag-free alloy, as well as the refinement of β' phase. The co

  2. Phase 1 study of monoclonal antibody I-131 3F8 targeted radiation therapy of human neuroblastoma

    International Nuclear Information System (INIS)

    This study is phase I of monoclonal antibody 131-I 3F8 targeted radiotherapy of human neuroblastoma. A murine IgG3 monoclonal antibody specific for ganglioside GD2(3F8), has unusually high (0.08% ID/g) tumor localization in patients and restricted distribution in normal tissues. Nine patients with refractory neuroblastoma (seven with soft tissue masses, four with bone disease, and three with bone marrow disease) have been treated with intravenous I-131 3F8 (10 μg 3F8) and oral saturated solution of potassium iodide and potassium perchlorate. Results are presented

  3. Microstructure and high tensile strength of Mg-10Gd-2Y-0.5Zr alloy by solid-state recycling

    International Nuclear Information System (INIS)

    Research highlights: → High tensile strength properties of the recycled GW102K alloy are achieved. → The metastable phases and the work-hardening are considered during heat treatment. → Aging response in the recycled alloy is similar to that in as-extruded reference. → Novel paper to obtain high tensile properties of the recycled Mg-RE alloy. - Abstract: In general, the tensile strengths of the solid-recycled Mg alloys are increased by T6 treatment after extrusion. For Mg alloy with high rare earth (RE) content, it is difficult to obtain the desired higher tensile strength compared with those extruded ones from the original ingots. In this paper, according to some characteristic of Mg-RE alloys, effect of heat treatment and extrusion temperature on the properties of the recycled Mg-10Gd-2Y-0.5Zr was studied. The results show that the aging response in the recycled specimens is similar to that in as-extruded reference samples. The deformation temperature is increased in order to inhibit Mg24(Gd,Y)5 particles precipitation and realize interfacial bonding between chips. After peak-aged treatment at 225 deg. C, the GW102K alloy consolidated at 450 deg. C exhibits excellent tensile strength. It is feasible to obtain the desired tensile properties of the recycled alloys by simultaneously promoting the precipitation of the metastable RE-containing phases and retaining the work-hardening effect during heat treatment.

  4. Mechanical properties of irradiated Gd2Zr2O7 pyrochlores as studied by nanoindentation technique - Effect of grains and grain boundaries

    Science.gov (United States)

    Kurpaska, L.; Jagielski, J.

    2016-07-01

    The influence of ion irradiation on nanomechanical properties of Gd2Zr2O7 pyrochlore have been studied. The polycrystalline samples were irradiated at room temperature with 320 keV Ar ions with fluences from 2 × 1014 to 1 × 1016 ions/cm2. Nanomechanical properties of grains and grains boundaries were measured by means of nanoindentation technique. The measurements were performed in the centers of the grains and at the grain boundaries and point to the conclusion that grain boundary region is usually characterized by higher hardness and Young's modulus than the center of the grain. The analysis performed suggests that the stress induced effect related to the transition to anion-deficient fluorite structure leads to the increase of recorded hardness values and may be considered as primary source of hardening. Studied phenomenon depends on the irradiation fluence and may serve as an indicator of the structure modification in the irradiated sample. Finally, nanomechanical properties of irradiated grain boundaries were interpreted in the frames of incorporation of foreign species near grain boundary.

  5. Luminescence characteristics of Dy3+ doped Gd2O3-CaO-SiO2-B2O3 scintillating glasses

    Institute of Scientific and Technical Information of China (English)

    J Kaewkhao; N Wantana; S Kaewjaeng; S Kothan; HJ Kim

    2016-01-01

    Glasses were prepared from the compositions of 25Gd2O3-10CaO-10SiO2-(55–x)B2O3-xDy2O3 (wherex is 0.0 mol.%–1.0 mol.%) by the conventional melt-quenching technique at 1400 ºC. The results demonstrated the increase in the glass density with re-spect to the increase in the doping concentrations of Dy2O3. Nine absorption bands were observed. The emission spectra of the de-veloped glass showed two strong peaks at 577 nm (4F9/2→6H13/2) and 482 nm (4F9/2→6H15/2). The highest emission intensity was ob-served from the developed glass prepared at 0.4 mol.% of Dy2O3, as the efficient energy transfer took place from Gd3+ to Dy3+. From the X-ray induced optical luminescence, the emission spectra were identical to those from PL measurements, but with the highest in-tensity observed from the glass quenched at 0.45 mol.% of Dy2O3. Finally, the integral scintillation efficiency of the developed glass was determined at 27% of that of the commercially available BGO crystal.

  6. Synthesis and screening of the system SrO-Gd2O3-Al2O3 doped with Tb by polymerized-complex combinatorial chemistry

    International Nuclear Information System (INIS)

    The combinatorial approach has been applied to discover and optimize the composition of the novel or enhanced materials. In this study, we screened the optimum composition of the system SrO-Gd2O3-Al2O3 doped with Tb3+ by a polymerized-complex combinatorial chemistry method. Mixtures with compositions of Sr, Gd and Al component that is in the range from 0 to 1 in about 0.05 increments could be tested. The sample powders were synthesized by a polymerized complex method. To prepare appropriately polymeric precursors, we used the metallic nitrates, citric acid and ethylene glycol. The luminescence properties of the synthesized powders are investigated using the UV and VUV (Vacuum-UV:147 nm) photoluminescence spectrometer. In addition, the crystallinity and morphology of powder were monitored by X-ray diffraction spectrometer and scanning electron microscopy. In result of VUV PL works, there are good luminescent samples with the composition of 0.5951-x-yAlxTbyOδ and 0.049xAl1-x-yTbyOδ, their materials can be applicable to plasma display panels as the green phosphor

  7. X-ray diffraction and Raman spectroscopy on Gd2(Ti2-yTey)O7 prepared at high pressure and high temperature

    International Nuclear Information System (INIS)

    A series of Te-substituted pyrochlores of stoichiometry Gd2(Ti2-yTey)O7 (y ≤ 0.2) were prepared under high-pressure and high-temperature conditions and characterized by X-ray diffraction, X-ray photoelectron spectroscopy and Raman spectroscopy. X-ray diffraction and X-ray photoelectron spectroscopy studies revealed that the Te4+ and Te6+ ions occupy the Ti4+sites; the percentage of the contribution of Te6+ increases as tellurium content. These substitutions induce an increase of the volume of the TiO6 octahedron due to the increase in the Ti-O(2) bond length, which preserves the oxygen positional parameter (x48f) and the Gd-O(1) bond length. Results of Raman spectroscopy showed a significant shift to higher frequencies of the Eg mode associated to the O(2) sublattice, as well an increase in the full-width-at-half-maximum intensity (FWHM) of the F2g mode (O-Gd-O bending) as the level of Te substitution for Ti increases. These results are discussed and compared with those reported in the literature.

  8. The effect of Gd2BaCuO5 nanoparticles on irreversibility fields of (Nd-Sm-Gd)Ba2Cu3O7-δ

    International Nuclear Information System (INIS)

    The flux pinning behaviour of (Nd1/3Sm1/3Gd1/3)Ba2Cu3O7-δ samples, having different concentrations x of Gd2BaCuO5 secondary-phase nanoparticles, was studied using magnetoresistivity data collected in the presence of 0, 0.5, 1, 2, 4, 6, 8 T magnetic fields (H) along and perpendicular to the c axis, with the transport current lying in the ab plane. Significant enhancement of the flux pinning and hence also the irreversibility field Hirr(T) was found. Hirr(T) extrapolated to 77K, Hirr77K(T), was determined from the Hirr(T) plots using best fits to an empirical formula, Hirr(T) Hirr(0)(1- T/Tc)a, where a is a constant. Hirr77K(T) for H parallel c axis (a) remains almost constant up to x = 0.2 (b) increases beyond x = 0.2 (c) peaks at x = 0.4 and (d) falls beyond x = 0.4. Further, Hirr77K(T) values are above 15T, the maximum being 243T for the 40wt% sample

  9. Preparation of translucent Gd2Si2O7:Ce polycrystalline thin plates and their scintillation performance for α-particles

    Science.gov (United States)

    Nishikata, Mami; Ueda, Aki; Higuchi, Mikio; Kaneko, Junichi H.; Tsubota, Youichi; Ishibashi, Hiroyuki

    2015-07-01

    Translucent Gd2Si2O7:Ce (GPS:Ce) polycrystalline plates were prepared via liquid-phase sintering using SiO2 as a self-flux, and their scintillation performances for α-particles were investigated. Dense sintered compacts comprising large grains, some of which were larger than 100 μm in diameter, were successfully prepared by sintering at 1690 °C for 100 h. The best result was obtained with the powder comprising only <40 μm particles. Any combination of powders of <40 μm and <15 μm resulted in inhomogeneous structures with smaller grains of about 50 μm. A translucent GPS:Ce thin plate was fabricated by grinding the sintered compact that contained excess SiO2 of 8 mol%. Since the plate was composed of large grains, scattering at the grain boundaries was effectively suppressed and many of the grains virtually act as single crystals when the plate thickness was less than 100 μm. Therefore, the decrease in the plate thickness brought increase in the total transmission, and light yield and energy resolution were consequently improved. When the plate thickness was 50 μm, light yield was 82% as compared with that of a GPS:Ce single crystal as a reference, and energy resolution attained to 13%.

  10. Microstructure and mechanical properties of extruded Mg-8Gd-2Y-1Nd-0.3Zn-0.6Zr alloy

    International Nuclear Information System (INIS)

    Highlights: → The extruded alloy rod exhibits a weak basal texture. → Tension-compression yield asymmetry varies with increasing temperature. → Yield asymmetry is influenced by the texture at room temperature. → With increasing temperature it is affected by solute atom cluster or precipitate. - Abstract: The microstructure and mechanical properties of extruded Mg-8Gd-2Y-1Nd-0.3Zn-0.6Zr alloy rods were investigated. The as-extruded alloy exhibits a weak basal texture that the {0 0 0 1} basal planes in most grains are distributed parallel to the extrusion direction. The strength of the peak-aged alloy is greatly improved due to the fine β' precipitates. Tension-compression asymmetry is observed in both the as-extruded and peak-aged alloys. The asymmetry at room temperature is connected with the texture which induces large difference in twinning generation between tension and compression. While increasing the test temperatures, the activation of twinning is suppressed, but the mechanical asymmetry still exists. For the as-extruded alloy it is related to the presence of dynamic strain ageing or dynamic precipitation during deformation; and for the peak-aged alloy it is associated with the β' precipitates.

  11. ФАЗОВЫЕ РАВНОВЕСИЯ В СИСТЕМЕ BAS AG2S GD2S3

    OpenAIRE

    Левен, И.; Андреев, О.

    2007-01-01

    Изучены фазовые равновесия в системе BaS-Ag2S-Gd2S3 при 1050°К. Впервые синтезировано соединение BaGdAgS3, которое проиндицировано в моноклинной сингонии, пространственной группы С2/т с параметрами э. я. а = 1.7564 (2) нм, Ъ = 0.4077 (1) нм, с = 0.8562 (9) нм, Ъ= 103.47°. Определено положение конод: BaGdAgS3 BaGd2S4, BaGdAgS3 BaS, Ag2S BaGdAgS3, Ag2S BaGd2S4, AgGdS2 BaGd2S4. В системе выделено 5 подчиненных треугольников: Ag2S-BaGdAgS3-BaS (I), Ag2S-BaGdAgS3-BaGd2S4 (11), Ag2S-BaGd2S4-AgGdS2 ...

  12. Optical emission, vibrational feature, and shear-thinning aspect of Tb3+-doped Gd2O3 nanoparticle-based novel ferrofluids irradiated by gamma photons

    Science.gov (United States)

    Paul, Nibedita; Hazarika, Samiran; Saha, Abhijit; Mohanta, Dambarudhar

    2013-10-01

    The present work reports on the spectroscopic and rheological properties of un-exposed and gamma (γ-) irradiated rare earth (RE) oxide nanoparticle-based ferrofluids (FFs). The FFs were produced by dispersing surfactant coated terbium (Tb3+)-doped gadolinium oxide (Gd2O3) nanoparticles in the ethanol medium and later on they were subjected to energetic γ-irradiation (1.25 MeV) at select doses (97 Gy and 2.635 kGy). The synthesized RE oxide nanoparticles were of ˜7 nm size and having a cubic crystal structure, as predicted from transmission electron microscopy and x-ray diffraction studies. Fourier transformed infra-red (FT-IR) spectra showed an adequate blue shift of the Gd-O vibrational stretching mode from a wavenumber value of ˜558 cm-1, for the un-irradiated sample to a value of ˜540 cm-1 corresponding to the irradiated sample (2.635 kGy). In contrast, photoluminescence spectra have revealed modification of defect states along with Tb3+ assisted radiative transitions. The rheology measurements have illustrated unusual shear thinning behavior of the FFs, with an apparently improved power index (s) value from 0.34 to 0.50, obtained for increasing γ-dose cases. The variation of the decay parameter with irradiation dose, as predicted from the nature of apparent viscosity curves, is attributed to the defect formation, role of impurity ions (Tb3+), and weakening of inter nanoparticle bonding. The unusual properties of the novel RE oxide based FFs may find scope in sealing and shielding elements in the radiation environment including accelerator and other related zones.

  13. Role of ytterbium-erbium co-doped gadolinium molybdate (Gd2(MoO4)3:Yb/Er) nanophosphors in solar cells.

    Science.gov (United States)

    Jin, Xiao; Li, Haiyang; Li, Dongyu; Zhang, Qin; Li, Feng; Sun, Weifu; Chen, Zihan; Li, Qinghua

    2016-09-01

    Insufficient harvest of solar light energy is one of the obstacles for current photovoltaic devices to achieve high performance. Especially, conventional organic/inorganic hybrid solar cells (HSCs) based on PTB7 as p-type semiconductor can only utilize 400-800 nm solar spectrum. One effective strategy to overcome this obstacle is the introduction of up-conversion nanophosphors (NPs), in the virtue of utilizing the near infrared region (NIR) of solar radiation. Up-conversion can convert low-energy photons to high-energy ones through multi-photon processes, by which the solar spectrum is tailored to well match the absorptive domain of the absorber. Herein we incorporate erbium-ytterbium co-doped gadolinium molybdate (Gd2(MoO4)3, GMO), denoted as GMO:Yb/Er, into TiO2 acceptor film in HSCs to enhance the light harvest. Here Er3+ acts as activator while Yb-MoO4 2- is the joint sensitizer. Facts proved that the GMO:Yb/Er single crystal NPs are capable of turning NIR photons to visible photons that can be easily captured by PTB7. Studies on time-resolved photoluminescence demonstrate that electron transfer rate at the interface increases sharply from 0.65 to 1.42 × 109 s-1. As a result, the photoelectric conversion efficiency of the GMO:Yb/Er doped TiO2/PTB7 HSCs reach 3.67%, which is increased by around 25% compared to their neat PTB7/TiO2 counterparts (2.94%). This work may open a hopeful way to take the advantage of those conversional rare-earth ion doped oxides that function in tailoring solar light spectrum for optoelectronic applications. PMID:27607730

  14. Effect of densification additive (Al (OH)3) and U3O8 recycle in sintering UO2-7wt% Gd2O3 fuel pellets

    International Nuclear Information System (INIS)

    The nuclear fuels are the consumable parts of nuclear reactors, and this has several consequences. From an economic point of view, it is important to keep the fuel into reactor for long time. In this context the use of burnable poison, as advanced fuel based in gadolinium oxide dispersed in a uranium oxide matrix, is a technological solution adopted worldwide. The function of the burnable poison fuels is to control the neutrons population in the nuclear reactors cores during its start up and the beginning of the fuel burning cycle to extending their use. In consequence of the use of this advanced fuel, the nuclear reactors can operate with higher rate of power, optimizing the use of the nuclear fuels. The objective of the present work is to show the development of UO2-7wt% Gd2O3 burnable absorber containing pellets by using mechanical blending of (Al(OH)3) densification additive and U3O8 of the recycling of nuclear fuel scrap. In the procedures, the gadolinium content of 7 wt% was established as a consequence of the P and D Cooperation Programmer firmed by the CTMSP and the INB, looking for the nationalization of this type of nuclear fuel used in the Nuclear Facility of Angra 2. The experimental results permit to observe the effectiveness action of the compound Al(OH)3 as a additive to promote the increasing in the densification of the (U-Gd)O2 pellets during its sintering, when amounts of recycle are recycled to the production processing up to 10 wt%, and when 0,20 wt% of Al(OH)3 is used as additive. (author)

  15. Bispecific antibodies.

    Science.gov (United States)

    Kontermann, Roland E; Brinkmann, Ulrich

    2015-07-01

    Bispecific antibodies (bsAbs) combine specificities of two antibodies and simultaneously address different antigens or epitopes. BsAbs with 'two-target' functionality can interfere with multiple surface receptors or ligands associated, for example with cancer, proliferation or inflammatory processes. BsAbs can also place targets into close proximity, either to support protein complex formation on one cell, or to trigger contacts between cells. Examples of 'forced-connection' functionalities are bsAbs that support protein complexation in the clotting cascade, or tumor-targeted immune cell recruiters and/or activators. Following years of research and development (R&D), the first bsAb was approved in 2009. Another bsAb entered the market in December 2014 and several more are in clinical trials. Here, we describe the potentials of bsAbs to become the next wave of antibody-based therapies, focusing on molecules in clinical development. PMID:25728220

  16. Synthesis and structural characterization of (Bi2O3)1– (Y2O3) and (Bi2O3)1– (Gd2O3) solid solutions

    Indian Academy of Sciences (India)

    Srikant Ekhelikar; G K Bichile

    2004-02-01

    Solid solution series, (Bi2O3)1– (Y2O$_3) and (Bi2O$_3)1– (Gd2O$_3), for = 0.10, 0.20, 0.30 and 0.40 were synthesized by standard ceramic technique. The structural phase characterization was carried out using X-ray powder diffraction technique. It was found that the solid solution containing 20–40 mole% of Y2O3 had face-centred cubic structure. All samples of the solid solution series, (Bi2O3)1– (Gd2O3), had rhombohedral single phase in the concentration range 0.10 ≤ ≤ 0.40. Lattice parameters of fcc phase of Y2O3 doped samples were calculated from the X-ray diffraction data. The lattice constant `’ gradually decreases with increasing content of dopant concentration () for the Y2O3 doped system and obeys Vegard’s rule. The unit cell parameters for the (Bi2O3)1– (Gd2O3) doped samples showing rhombohedral phase were obtained on hexagonal setting.

  17. Therapeutic Strategies for Human IgM Antibodies Directed at Tumor-Associated Ganglioside Antigens: Discoveries Made During the Morton Era and Future Directions.

    Science.gov (United States)

    Jones, Peter C; Irie, Reiko F

    2016-01-01

    Tumor-associated gangliosides have been investigated for their potential as antigenic targets for more than 35 years, culminating in the recent Food and Drug Administration approval of dinutuximab (Unituxin), an IgG antibody targeted against GD2, for the treatment of neuroblastoma in children. This review is focused on discoveries and development of therapeutic approaches involving human IgM antibodies directed against gangliosides, which occurred over the past 40 years at University of California-Los Angeles and the John Wayne Cancer Institute, where Dr. Donald Morton led the surgical oncology department until his death. PMID:27481004

  18. Luminescent properties and energy transfer of Ce3+-activated Li2O–B2O3–Gd2O3 scintillating glasses under VUV–UV and X-ray excitation

    International Nuclear Information System (INIS)

    Motivated by potential application for neutron detection, novel Ce3+-activated Li2O–B2O3–Gd2O3 scintillating glasses containing neutron-capture elements were synthesized by melt-quenching method. The energy transfer from the host glass to Gd3+ and Ce3+ ions, as well as from Gd3+ to Ce3+ ions are confirmed by VUV–UV spectra. The strongest emission intensity of Ce3+ ions with about 29 ns is obtained when the scintillating glass contains a fraction of 0.25 mol% CeF3, whose mean distance is estimated to be about 25.63 Å

  19. The influence on the crystallization of Ag doped Gd2 O3-MoO3-B2 O3 glass induced by 250 kHz,800 nm femtosecond laser irradiation%Ag掺杂对高重复频率飞秒激光诱导Gd2 O3-MoO3-B2 O3玻璃析晶的影响

    Institute of Scientific and Technical Information of China (English)

    韩咏梅; 易传祥; 刘丽萍; 张子辰; 钟敏建; 马洪良

    2014-01-01

    We report the influence of the Ag doping on the crystallization ofβ′-Gd2 (MoO4 )3 crystal in the Gd2 O3-MoO3-B2 O3 glasses induced by femtosecond laser irradiation.The fs laser pulses were focused on the surface of Ag-doped Gd2 O3-MoO3-B2 O3 glasses and non-doped Gd2 O3-MoO3-B2 O3 glasses,and the effect of silver on crystallization of b¢-Gd2 (MoO4 )3 crystals in glasses were analyzed.The results indica-ted that the silver greatly enhanced the crystallization of the glass during the fs pulses irradiation.The responsible mechanism for the observed phenomenon can be explained as follows:The glass oxygen bonds are broken by mlti-photon absorption during the femtosecond irradiation,which results in the non-bridging oxygen holes and free electrons.The Ag+ ions capture free electrons to form Ag atoms. Ag atoms move and aggregate to form nanoclaster owning to the thermal driving.Ag nanoclusters act as nuclear and greatly promote the crystallization of the glass.%将800 nm高重复频率250 kHz的飞秒激光分别聚焦到掺Ag和没有掺Ag的Gd2 O3-MoO3-B2 O3玻璃表面,研究掺 Ag对飞秒激光诱导析晶的影响。对激光辐照的区域显微拉曼分析发现对于没掺 Ag 玻璃,诱导玻璃析晶需要的激光功率和辐照时间比掺了 Ag的玻璃要大要长,这说明 Ag的掺入促进了玻璃的析晶。其机理可能为飞秒激光的多光子吸收效应,导致玻璃基质中桥氧键断裂,产生非桥氧空穴和自由电子,玻璃中的 Ag离子捕获电离出来的电子被还原成 Ag 原子,Ag 原子在热动力的驱动下移动聚集形成银纳米颗粒,形成的银纳米团簇作为核促进了钼酸盐玻璃的析晶。

  20. Monoclonal antibodies

    International Nuclear Information System (INIS)

    Monoclonal antibodies (MAbs) are antibodies having single specificity for a given antigen site (epitope). The development of hybridoma technology and the relative ease by which MAbs can be prepared has revolutionized many aspects of serological applications in diagnosis and differentiation of disease producing agents. The property of monospecificity offers advantages in diagnostic applications over polyclonal sera in that tests can be defined exactly with regard to the antigen detected and the affinity of reaction between the given antigenic site and the monoclonal reagent. In addition, MAbs offer better possibilities for test standardization, because the same reagent can be used in different laboratories. Such an MAb can be supplied by a central laboratory or 'grown' from hybridoma cells, ensuring that the resultant product is identical from laboratory to laboratory and that the part of the test involving the MAb reaction is the same. The methodologies for inoculation regimes, mice, cloning methods, selection of fusion partners, etc., have been validated extensively in developed country laboratories. The decision to establish a MAb production facility must be examined on a strict cost-benefit basis, since it is still expensive to produce a product. There are many MAbs available that should be sought to allow exploitation in developing tests. If a production facility is envisaged, it should produce reagents for national needs, i.e. there should be a clear problem oriented approach whereby exact needs are defined. In the field of veterinary applications, MAbs are the central reagent in many immunoassays based on the enzyme linked immunosorbent assay (ELISA). The development of specific tests for diagnosing diseases is dominated by MAbs and has been fuelled by a strong research base, mainly in developed countries allied to developing countries through the study of related diseases. Thus, there are very many assays dependent on MAbs, some of which form the basis of

  1. Monoclonal antibodies.

    Science.gov (United States)

    2009-01-01

    The ability to produce and exploit monoclonal antibodies (mAbs) has revolutionized many areas of biological sciences. The unique property of an mAb is that it is a single species of immunoglobulin (IG) molecule. This means that the specificity of the interaction of the paratopes on the IG, with the epitopes on an antigenic target, is the same on every molecule. This property can be used to great benefit in immunoassays to provide tests of defined specificity and sensitivity, which improve the possibilities of standardization. The performance of assays can often be determined relating the actual weight of antibody (hence the number of molecules) to the activity. Often the production of an mAb against a specific epitope is the only way that biological entities can be differentiated. This chapter outlines the areas involving the development of assays based on mAbs. The problems involved address include the physical aspects of mAbs and how they may affect assay design and also the implications of results based on monospecific reagents. Often these are not fully understood, leading to assays that are less than satisfactory, which does not justify the relatively high cost of preparing and screening of mAbs. There are many textbooks and reviews dealing with the preparation of mAbs, the principles involved, and various purification and manipulative methods for the preparation of fragments and conjugation. There has been little general information attempting to summarize the best approaches to assay design using mAbs. Much time can be wasted through bad planning, and this is particularly relevant to mAbs. A proper understanding of some basic principles is essential. It is beyond the scope of this chapter to discuss all aspects, but major areas are highlighted. PMID:19219589

  2. Nonlinear optical properties of pulsed laser deposited Gd2O3 and Dy2O3 doped K0.5Na0.5NbO3 thin films

    Science.gov (United States)

    Peddigari, Mahesh; Pattipaka, Srinivas; Bharti, Gyan Prakash; Khare, Alika; Dobbidi, Pamu

    2016-08-01

    We report the structural and nonlinear optical properties of Gd2O3 and Dy2O3 doped (K0.5Na0.5)NbO3 (KNN) lead-free thin films fabricated by pulsed laser deposition technique. The crystal structure of the films was analyzed by using Rietveld method. The higher tetragonality and improved surface morphology was observed for the rare-earth oxide doped films. The change in crystal structure and tetragonality with these dopants was explained in terms of change in the internal vibration modes of NbO6 octahedra. The nonlinear optical properties of the films were measured by using single beam Z-scan technique with a continuous wave He-Ne laser (λ = 632.8 nm). All the films have shown a large third-order nonlinear susceptibility and observed to be enhanced for rare-earth doped KNN thin films (|χ(3)| = 2.69 × 10-3 esu). The maximum nonlinear refractive index, n2 = 2.02 × 10-5 cm2/W, and nonlinear absorption coefficient, β = 3.48 cm/W, were obtained for Gd2O3, and Dy2O3 doped films respectively. These results indicate that rare-earth doped KNN thin films are potential candidates for nonlinear photonic applications.

  3. Crystallization of 21.25Gd 2O 3-63.75MoO 3-15B 2O 3 glass induced by femtosecond laser at the repetition rate of 250 kHz

    Science.gov (United States)

    Zhong, M. J.; Han, Y. M.; Liu, L. P.; Zhou, P.; Du, Y. Y.; Guo, Q. T.; Ma, H. L.; Dai, Y.

    2010-12-01

    We report the formation of β'-Gd 2(MoO 4) 3 (GMO) crystal on the surface of the 21.25Gd 2O 3-63.75MoO 3-15B 2O 3 glass, induced by 250 kHz, 800 nm femtosecond laser irradiation. The morphology of the modified region in the glass was clearly examined by scanning electron microscopy (SEM). By micro-Raman spectra, the laser-induced crystals were confirmed to be GMO phases and it is found that these crystals have a strong dependence on the number and power of the femtosecond laser pulses. When the irradiation laser power was 900 mW, not only the Raman peaks of GMO crystals but also some new peaks at 214 cm -1, 240 cm -1, 466 cm -1, 664 cm -1 and 994 cm -1which belong to the MoO 3 crystals were observed. The possible mechanisms are proposed to explain these phenomena.

  4. Cathodoluminescence of Ce-doped Gd2SiO5 and Gd9.33(SiO4)6O2 phosphor under continuous electron irradiation

    International Nuclear Information System (INIS)

    Research highlights: → GSO:Ce is stable under continuous electron irradiation. → GSO:Ce has high luminescence efficiency. → GSO:Ce has rigid crystal structure. - Abstract: Cathodoluminescence was studied on well crystallized Ce-doped Gd2SiO5 (GSO:Ce) and Gd9.33(SiO4)6O2 (GSAP:Ce) prepared by calcining the hydrolyzed alkoxides at 1573 K because GSO:Ce is easily contaminated with GSAP:Ce impurity in solid state reaction. The luminescence efficiency of GSO:Ce was much higher than that of GSAP:Ce, and Stokes shift of the former was smaller than that of the latter, due to the crystal structural difference between the compounds in Gd2O3 and SiO2 binary chemical composition. The luminescence of GSO:Ce degraded much less than that of GSAP:Ce under the continuous electron irradiation (CL degradation). The CL degradation was related to the formation of the carbon overlayer on the phosphor particles from the vacuum ambient during the irradiation in the present manuscript. The amount of the deposited carbon was influenced by the luminescence efficiency.

  5. Crystallization of 21.25Gd2O3-63.75MoO3-15B2O3 glass induced by femtosecond laser at the repetition rate of 250 kHz

    International Nuclear Information System (INIS)

    We report the formation of β'-Gd2(MoO4)3 (GMO) crystal on the surface of the 21.25Gd2O3-63.75MoO3-15B2O3 glass, induced by 250 kHz, 800 nm femtosecond laser irradiation. The morphology of the modified region in the glass was clearly examined by scanning electron microscopy (SEM). By micro-Raman spectra, the laser-induced crystals were confirmed to be GMO phases and it is found that these crystals have a strong dependence on the number and power of the femtosecond laser pulses. When the irradiation laser power was 900 mW, not only the Raman peaks of GMO crystals but also some new peaks at 214 cm-1, 240 cm-1, 466 cm-1, 664 cm-1 and 994 cm-1which belong to the MoO3 crystals were observed. The possible mechanisms are proposed to explain these phenomena.

  6. Thermophysical Properties of Gd2 O3-Yb2 O3-Y2 O3-ZrO2 Thermal Barrier Coating Material%Gd2O3-Yb2O3-Y2O3-ZrO2热障涂层材料的热物理性能

    Institute of Scientific and Technical Information of China (English)

    李嘉; 谢铮; 何箐; 邹晗; 吕玉芬

    2015-01-01

    Objective To improve the performance of traditional ceramic thermal barrier coatings by rare earth oxides doping yt-tria stabilized zirconia ( YSZ) . Methods The Gd2 O3-Yb2 O3-Y2 O3-ZrO2( GYYZO) materials with various doped contents were pre-pared by co-precipitation, and the GYYZO bulk materials and coatings were prepared by cold isostatic pressing ( CIP) and plasma spraying( PS) , respectively. The thermal conductivity and thermal expansion coefficient tests of materials with different composi-tions were taken to analyze and evaluate the thermophysical properties of GYYZO materials. X-ray diffraction ( XRD) analysis of the coatings was conducted after high-temperature annealing treatment to evaluate the high temperature stability of coatings with dif-ferent compositions. Results The thermal conductivities and coefficient of thermal expansion ( CTEs) of zirconia based bulk materi-als decreased with the increasing doped content. The thermal conductivity of bulk GYYZO doped with 5. 5% ~9. 84% mole frac-tion of rare earth oxides at 1000 ℃ was 1. 25~1. 56 W/(m·K), which was reduced by 22% ~37. 5% as compared with that of bulk 8YSZ, and the CTEs was (10~11. 1) ×10-6/K, which was closed to that of the tradition 8YSZ materials. After long-term heat treatment at 1400℃, the content of monoclinic phase for GYYZO coating with low doped content was obviously lower than that of 8YSZ coating. Conclusion The multiple rare earth oxides doped YSZ has good high temperature phase stability, low thermal conductivity and suitable thermal expansion coefficient, and can be used as candidate ceramic materials for high-performance ther-mal barrier coatings.%目的:通过多元稀土氧化物掺杂改性YSZ,提高传统热障涂层的性能。方法使用化学共沉淀法制备不同掺杂量的Gd2 O3-Yb2 O3-Y2 O3-ZrO2( GYYZO)材料,并分别使用冷等静压-烧结和等离子喷涂工艺制备块材和涂层。通过测试块材的热导率和热膨胀系数,分析评价材

  7. Formation and Optical Properties of Ag Nanoparticles in CaB4O7–Ag2O and CaB4O7–Gd2O3–Ag2O Tetraborate Glasses

    Directory of Open Access Journals (Sweden)

    V.T. Adamiv

    2014-11-01

    Full Text Available Formation of Ag nanoparticles (NPs in the near-surface layer of CaB4O7–Ag2O and CaB4O7 –Gd2O3–Ag2O glasses by annealing in vacuum or in air is reported. It is concluded that annealing in vacuum does not necessary require the presence of reducing ions. Intensive plasmon absorption bands peaked at 403, 406 and 413.3 nm were observed in the absorption spectra of glasses with Ag NPs. Average radius of nanoparticles was calculated from the plasmon band half width and falls within 1.3-3.3 nm. It is concluded that calculated from normalized transmission spectra and absorption spectra the non-linear refractive index n2 increases due to the plasmon resonance in Ag NPs.

  8. Formation and Optical Properties of Ag Nanoparticles in CaB4O7–Ag2O and CaB4O7–Gd2O3–Ag2O Tetraborate Glasses

    OpenAIRE

    V.T. Adamiv; Ya.V. Burak; R.V. Gamernyk; R.M. Dutka; I.M. Teslyuk

    2014-01-01

    Formation of Ag nanoparticles (NPs) in the near-surface layer of CaB4O7–Ag2O and CaB4O7 –Gd2O3–Ag2O glasses by annealing in vacuum or in air is reported. It is concluded that annealing in vacuum does not necessary require the presence of reducing ions. Intensive plasmon absorption bands peaked at 403, 406 and 413.3 nm were observed in the absorption spectra of glasses with Ag NPs. Average radius of nanoparticles was calculated from the plasmon band half width and falls within 1.3-3.3 nm. It i...

  9. Síntesis y caracterización de los sistemas Eu(2 subíndice) O(3 subíndice) y Gd(2 subíndice) O(3 subíndice) por molienda mecánica

    OpenAIRE

    Campos Vaquero, Beatriz

    2011-01-01

    This project studies the synthesis of systems Gd2 O3 and Eu2O3 by high energy mechanical milling and the system Gd2O3:Eu by Spray Pyrolysis, comparing the results by the techniques of X-ray diffraction and fluorescence. The sample preparation was performed by mechanical milling in a vibratory mill where samples were taken every hour from 1 hour to 12 hours. These samples were characterized by various techniques such as X-ray diffraction, electron microscopy barrrido (SEM), differential scanni...

  10. Antibodies and Selection of Monoclonal Antibodies.

    Science.gov (United States)

    Hanack, Katja; Messerschmidt, Katrin; Listek, Martin

    2016-01-01

    Monoclonal antibodies are universal binding molecules with a high specificity for their target and are indispensable tools in research, diagnostics and therapy. The biotechnological generation of monoclonal antibodies was enabled by the hybridoma technology published in 1975 by Köhler and Milstein. Today monoclonal antibodies are used in a variety of applications as flow cytometry, magnetic cell sorting, immunoassays or therapeutic approaches. First step of the generation process is the immunization of the organism with appropriate antigen. After a positive immune response the spleen cells are isolated and fused with myeloma cells in order to generate stable, long-living antibody-producing cell lines - hybridoma cells. In the subsequent identification step the culture supernatants of all hybridoma cells are screened weekly for the production of the antibody of interest. Hybridoma cells producing the antibody of interest are cloned by limited dilution till a monoclonal hybridoma is found. This is a very time-consuming and laborious process and therefore different selection strategies were developed since 1975 in order to facilitate the generation of monoclonal antibodies. Apart from common automation of pipetting processes and ELISA testing there are some promising approaches to select the right monoclonal antibody very early in the process to reduce time and effort of the generation. In this chapter different selection strategies for antibody-producing hybridoma cells are presented and analysed regarding to their benefits compared to conventional limited dilution technology. PMID:27236550

  11. Antiphospholipid Antibody Syndrome

    Science.gov (United States)

    ... page from the NHLBI on Twitter. What Is Antiphospholipid Antibody Syndrome? Antiphospholipid (AN-te-fos-fo-LIP-id) antibody ... weeks or months. This condition is called catastrophic antiphospholipid syndrome (CAPS). People who have APS also are at ...

  12. The antibody mining toolbox

    OpenAIRE

    D'Angelo, Sara; Glanville, Jacob; Ferrara, Fortunato; Naranjo, Leslie; Gleasner, Cheryl D.; Shen, Xiaohong; Bradbury, Andrew RM; Kiss, Csaba

    2013-01-01

    In vitro selection has been an essential tool in the development of recombinant antibodies against various antigen targets. Deep sequencing has recently been gaining ground as an alternative and valuable method to analyze such antibody selections. The analysis provides a novel and extremely detailed view of selected antibody populations, and allows the identification of specific antibodies using only sequencing data, potentially eliminating the need for expensive and laborious low-throughput ...

  13. Heavy chain only antibodies

    DEFF Research Database (Denmark)

    Moghimi, Seyed Moein; Rahbarizadeh, Fatemeh; Ahmadvand, Davoud;

    2013-01-01

    Unlike conventional antibodies, heavy chain only antibodies derived from camel contain a single variable domain (VHH) and two constant domains (CH2 and CH3). Cloned and isolated VHHs possess unique properties that enable them to excel conventional therapeutic antibodies and their smaller antigen...

  14. Hepatitis A virus antibody

    International Nuclear Information System (INIS)

    A description is presented of a radioimmunoassay designed to prove the presence of the antibody against the hepatitis A virus (HA Ab, anti-Ha) using an Abbott HAVAB set. This proof as well as the proof of the antibody against the nucleus of the hepatitis B virus is based on competition between a normal antibody against hepatitis A virus and a 125I-labelled antibody for the binding sites of a specific antigen spread all over the surface of a tiny ball; this is then indirect proof of the antibody under investigation. The method is described of reading the results from the number of impulses per 60 seconds: the higher the titre of the antibody against the hepatitis A virus in the serum examined, the lower the activity of the specimen concerned. The rate is reported of incidence of the antibody against the hepatitis A virus in a total of 68 convalescents after hepatitis A; the antibody was found in 94.1%. The immunoglobulin made from the convalescents' plasma showed the presence of antibodies in dilutions as high as 1:250 000 while the comparable ratio for normal immunoglobulin Norga was only 1:2500. Differences are discussed in the time incidence of the antibodies against the hepatitis A virus, the antibodies against the surface antigen of hepatitis B, and the antibody against the nucleus of the hepatitis V virus. (author)

  15. Monoclonal antibodies and cancer

    International Nuclear Information System (INIS)

    The usefulness of radiolabeled monoclonal antibodies for imaging and treatment of human (ovarian) cancer was investigated. A review of tumor imaging with monoclonal antibodies is presented. Special attention is given to factors that influence the localization of the antibodies in tumors, isotope choice and methods of radiolabeling of the monoclonal antibodies. Two monoclonal antibodies, OC125 and OV-TL3, with high specificity for human epithelial ovarian cancer are characterized. A simple radio-iodination technique was developed for clinical application of the monoclonal antibodies. The behavior of monoclonal antibodies in human tumor xenograft systems and in man are described. Imaging of tumors is complicated because of high background levels of radioactivity in other sites than the tumor, especially in the bloodpool. A technique was developed to improve imaging of human tumor xenographs in nude mice, using subtraction of a specific and a non-specific antibody, radiolabeled with 111In, 67Ga and 131I. To investigate the capability of the two monoclonal antibodies, to specifically localize in human ovarian carcinomas, distribution studies in mice bearing human ovarian carcinoma xenografts were performed. One of the antibodies, OC125, was used for distribution studies in ovarian cancer patients. OC125 was used because of availability and approval to use this antibody in patients. The same antibody was used to investigate the usefulness of radioimmunoimaging in ovarian cancer patients. The interaction of injected radiolabeled antibody OC125 with circulating antigen and an assay to measure the antibody response in ovarian cancer patients after injection of the antibody is described. 265 refs.; 30 figs.; 19 tabs

  16. Electronic structure and nesting-driven enhancement of the RKKY interaction at the magnetic ordering propagation vector in Gd2PdSi3 and Tb2PdSi3

    International Nuclear Information System (INIS)

    We present first-time measurements of the Fermi surface and low-energy electronic structure of intermetallic compounds Gd2PdSi3 and Tb2PdSi3 by means of angle-resolved photoelectron spectroscopy (ARPES). We show that the Fermi surface in both compounds consists of an electron barrel at the Γ point surrounded by spindle-shaped electron pockets originating from the same band, with the band bottom of both features lying at 0.5 eV below the Fermi level. From the experimentally measured band structure, we estimate the momentum-dependent RKKY coupling strength and demonstrate that it is peaked at the 1/2Γ K wave vector. Comparison with neutron diffraction data from the same crystals shows perfect agreement of this vector with the propagation vector of the low-temperature in-plane magnetic order, thereby demonstrating the decisive role of the Fermi surface geometry in explaining the complex magnetically ordered ground state of ternary rare earth silicides.

  17. Spontaneous polarization and pyroelectric effect in improper ferroelectrics-ferroelastics Gd2(MoO4)3 and Tb2(MoO4)3 at low temperature

    International Nuclear Information System (INIS)

    Experimental dependencies for spontaneous polarization ΔPs(T) and pyroelectric coefficient γs(T)for Gd2(MoO4)3 (GMO) and Tb2(MoO4)3 (TMO) reported here differs from those for intrinsic ferroelectrics. We found fundamental distinction in GMO and TMO samples behavior at their repolarization at the fixed temperatures 300 and 4.2 K. In TMO monodomainization temperature does not affect experimental data, while in GMO monodomainization at 4.2 K results in increase of ΔPs (T) by order of magnitude at 85 K and γs(T) dependence shows well-defined anomalies, reaching a record magnitude of 3 centre dot 10-4 C/(m2 centre dot K) at T = 25 K. At T = 200 K the pyroelectric coefficients values are -1.45 centre dot 10-6 C/(m2 centre dot K) and-1.8 centre dot 10-6 C/(m2 centre dot K). Taking into account our data, results related to transformation of structure in (001) plane and symmetry reasons we suggested crystallographic model of GMO type improper ferroelectric. It is formed by four meso-tetrahedrons constructed of three coordination tetrahedrons MO4 (a, b and c types). In the framework of this model we discuss the physical meaning of pseudodeviator Q12*, coefficient, that initiate the phase transition at T > 433 K from noncentrosymmetric phase (mm2) to another one (4-bar2m).

  18. Luminescent properties and application of Eu3+ -activated Gd2(MoO4)3 red-emitting phosphor with pseudo-pompon shape for solid-state lighting

    Institute of Scientific and Technical Information of China (English)

    HE

    2010-01-01

    Eu3+ -activated Gd2(MoO4)3 pseudo-pompon-like red-emitting phosphors were prepared by solid-state method.The structure,morphology,and luminescent properties of these powder samples were investigated by X-ray diffraction (XRD),scanning electron microscopy(SEM),and fluorescent spectrophotometry,respectively.The as-obtained phosphors were single crystalline phase with orthorhombic unit cell.The particles of the powder samples had the length of 5-12 μm and width of 3-7 μm with flake shape and large surface area,which is suitable for manufacture of white LEDs.The phosphor could be efficiently excited by the incident light of 348-425 nm,well matched with the output wavelength of near-UV (In,Ga)N chip,and re-emitted an intense red light peaking at 615 nm.By combing this phosphor with a~395 nmemitting (In,Ga)N chip,a red LED was fabricated,so that the applicability of this novel phosphor to white LEDs was confirmed.It is considered to be an efficient red-emitting conversion phosphor for solid-state lighting based on (In,Ga)N LEDs.

  19. Engineering antibody therapeutics.

    Science.gov (United States)

    Chiu, Mark L; Gilliland, Gary L

    2016-06-01

    The successful introduction of antibody-based protein therapeutics into the arsenal of treatments for patients has within a few decades fostered intense innovation in the production and engineering of antibodies. Reviewed here are the methods currently used to produce antibodies along with how our knowledge of the structural and functional characterization of immunoglobulins has resulted in the engineering of antibodies to produce protein therapeutics with unique properties, both biological and biophysical, that are leading to novel therapeutic approaches. Antibody engineering includes the introduction of the antibody combining site (variable regions) into a host of architectures including bi and multi-specific formats that further impact the therapeutic properties leading to further advantages and successes in patient treatment. PMID:27525816

  20. Generating Generalized $G_{D-2}$ solutions

    CERN Document Server

    Bretón, N; López, L A

    2008-01-01

    We show how one can systematically construct vacuum solutions to Einstein field equations with $D-2$ commuting Killing vectors in $D>4$ dimensions. The construction uses Einstein-scalar field seed solutions in 4 dimensions and is performed both for the case when all the Killing directions are spacelike, as well as when one of the Killing vectors is timelike. The later case corresponds to generalizations of stationary axially symmetric solutions to higher dimensions. Some examples representing generalizations of known higher dimensional stationary solutions are discussed in terms of their rod structure and horizon locations and deformations.

  1. Affinity purification of antibodies

    Science.gov (United States)

    Antibodies are provided in a variety of formats that includes antiserum, hybridoma culture supernatant or ascites. They can all be used successfully in crude form for the detection of target antigens by immunoassay. However, it is advantageous to use purified antibody in defined quantity to facil...

  2. Therapeutic Recombinant Monoclonal Antibodies

    Science.gov (United States)

    Bakhtiar, Ray

    2012-01-01

    During the last two decades, the rapid growth of biotechnology-derived techniques has led to a myriad of therapeutic recombinant monoclonal antibodies with significant clinical benefits. Recombinant monoclonal antibodies can be obtained from a number of natural sources such as animal cell cultures using recombinant DNA engineering. In contrast to…

  3. Production Of Human Antibodies

    Science.gov (United States)

    Sammons, David W.; Neil, Garry A.

    1993-01-01

    Process for making human monoclonal antibodies based on combination of techniques. Antibodies made active against specific antigen. Process involves in vivo immunization of human B lymphocyte cells in mice. B cells of interest enriched in vitro before fusion. Method potentially applicable to any antigen. Does not rely on use of Epstein-Barr virus at any step. Human lymphocytes taken from any source.

  4. RBC Antibody Screen

    Science.gov (United States)

    ... the baby is Rh-positive and the mother's antibody status is negative for anti-D, the mother is given additional RhIG. This test also may be used to help diagnose autoimmune-related hemolytic anemia ... when a person produces antibodies against his or her own RBC antigens. This ...

  5. Antibody affinity maturation

    DEFF Research Database (Denmark)

    Skjødt, Mette Louise

    Yeast surface display is an effective tool for antibody affinity maturation because yeast can be used as an all-in-one workhorse to assemble, display and screen diversified antibody libraries. By employing the natural ability of yeast Saccharomyces cerevisiae to efficiently recombine multiple DNA...

  6. Spontaneous polarization and pyroelectric effect in the improper ferroelectrics-ferroelastics Gd2(MoO4)3 and Tb2(MoO4)3 at low temperatures

    Science.gov (United States)

    Matyjasik, S.; Shaldin, Yu. V.

    2013-11-01

    The experimental variations in the spontaneous polarization ΔPs(T) and pyroelectric coefficient γs(T) for Gd2(MoO4)3 (GMO) and Tb2(MoO4)3 (TMO) at low temperatures reported here differ from those for intrinsic ferroelectrics. A fundamental difference is found in the repolarization behavior of samples of GMO and TMO at fixed temperatures of 300 and 4.2 K. While the single domain formation temperature essentially has no effect on the measurements for TMO, a fundamental difference is observed in the case of GMO: single domain formation in the latter at 4.2 K leads to an order of magnitude increase in ΔPs at T > 85 K and distinct anomalies are observed in γs(T), at one of which the pyroelectric coefficient reaches a record peak of 3 × 10-4 C/(m2.K) at T = 25 K. At T = 200 K the pyroelectric coefficients equal -1.45 and -1.8 in units of 10-6 C/(m2.K). Based on these results and taking published data on the rotational structural transformation in the (001) plane and symmetry considerations into account, we propose a crystal physical model for GMO-type improper ferroelectrics consisting of four mesotetrahedra, each of which is made up of three different types (a, b, c) of MoO4 coordination tetrahedra. The physical significance of the pseudodeviator coefficient Q12*, which initiates the phase transition at T > 433 K from one non-centrally symmetric phase (mm2) into another (4¯2m), is discussed in terms of this model.

  7. Cytotoxic activity against human neuroblastoma and melanoma cells mediated by IgM antibodies derived from peripheral blood of healthy donors.

    Science.gov (United States)

    Devarapu, Satish Kumar; Mamidi, Srinivas; Plöger, Frank; Dill, Othmar; Blixt, Ola; Kirschfink, Michael; Schwartz-Albiez, Reinhard

    2016-06-15

    A small percentage of healthy donors identified in the Western population carry antibodies in their peripheral blood which convey cytotoxic activity against certain human melanoma and neuroblastoma cell lines. We measured the cytotoxic activity of sera and plasmas from healthy donors on the human neuroblastoma cell line Kelly and various melanoma cell lines. Antibodies of IgM isotype, presumably belonging to the class of naturally occurring antibodies, exerted cytotoxic activity in a complement-dependent fashion. Apart from complement-dependent tumor cell lysis, we observed C3 opsonization in all tumor cell lines upon treatment with cytotoxic plasmas. Cell lines tested primarily expressed membrane complement regulatory proteins (mCRP) CD46, CD55 and CD59 to various extents. Blocking of mCRPs by monoclonal antibodies enhanced cell lysis and opsonization, though some melanoma cells remained resistant to complement attack. Epitopes recognized by cytotoxic antibodies were represented by gangliosides such as GD2 and GD3, as evidenced by cellular sialidase pretreatment and enhanced expression of distinct gangliosides. It remains to be clarified why only a small fraction of healthy persons carry these antitumor cytotoxic antibodies. PMID:26830059

  8. Selection of Recombinant Human Antibodies.

    Science.gov (United States)

    Tomszak, Florian; Weber, Susanne; Zantow, Jonas; Schirrmann, Thomas; Hust, Michael; Frenzel, André

    2016-01-01

    Since the development of therapeutic antibodies the demand of recombinant human antibodies is steadily increasing. Traditionally, therapeutic antibodies were generated by immunization of rat or mice, the generation of hybridoma clones, cloning of the antibody genes and subsequent humanization and engineering of the lead candidates. In the last few years, techniques were developed that use transgenic animals with a human antibody gene repertoire. Here, modern recombinant DNA technologies can be combined with well established immunization and hybridoma technologies to generate already affinity maturated human antibodies. An alternative are in vitro technologies which enabled the generation of fully human antibodies from antibody gene libraries that even exceed the human antibody repertoire. Specific antibodies can be isolated from these libraries in a very short time and therefore reduce the development time of an antibody drug at a very early stage.In this review, we describe different technologies that are currently used for the in vitro and in vivo generation of human antibodies. PMID:27236551

  9. Development of a method to measure kinetics of radiolabelled monoclonal antibody in human tumour with applications to microdosimetry: positron emission tomography studies of iodine-124 labelled 3F8 monoclonal antibody in glioma

    International Nuclear Information System (INIS)

    We present a method to assess quantitatively the immuhological characteristics of tumours using radiolabelled monoclonal antibody and positron emission tomography (PET) to improve dosimetry for radioimmunotherapy. This method is illustrated with a glioma patient who injected with 96.2 MPq of iodine-124 labelled 3FB, a murine antibody (IgG3) specific against the ganglioside GD2. Serial PET scans and plasma samples were taken over 11 days. A three-compartment model was used to estimate the plasma to tumour transfer constant (K1), the tumour to plasma transfer constant k2, the association and dissociation constants (k3, k4) of antibody binding, and the binding potential. Tumour radioactivity peaked at 18 h at 0.0045% ID/g. The kinetic parameters were estimated to be: K1=0.048 ml h-1 g-1, k2=0.16 h-1, k3=0.03 h-1, k4=0.015 h-1 and BP=2.25. Based on these kinetic parameters, the amount of tumour-bound radiolabelled monoclonal antibody was calculated. This method permits estimates of both macrodosimetry and microdosimetry at the cellular level based on in vivo non-invasive measurement. (orig.)

  10. Immunoscintigraphy of human neuroblastoma xenografted in nude mice using a panel of 125I-labelled monoclonal antibodies

    International Nuclear Information System (INIS)

    Neuroblastoma is the most frequent tumour of the childhood under the age of 5. The staging and the follow up are achieved by MIBG scintigraphy, considered as the method of reference, but sometimes difficult to interpret. The availability of monoclonal antibodies against the ganglioside GD2, expressed on the cell membrane of neuroblastoma and neuro-endocrine cancers offers novel tools that deserve to be carefully explored. We investigated four mouse monoclonal antibodies (3 lgG3: BW704, 7A4, 60C3, and the lgG1 variant of BW704: MAK704), on nude mice xenografted with a human neuroblastoma (REM). Sixty one nude mice were included. The three former MAbs provided tumour imaging, the best results being obtained with BW704, followed by 7A4 and 60C3. MAK704 was disappointing. A control antiphosphorylcholine antibody (P51-1) did not give any tumour image in the three tested mice. Scintigraphy ratios tumour/liver and tumour/muscle reached 20 and 100 with BW704, respectively, on the 10th day. Good imaging quality was already obtained from the 24th h. The tumour uptake, calculated from radioactivity countings of resected samples, reached 22 ± 3% of injected dose per gram. These results let us hope that these antibodies could also provide highly contrasted images in humans and could open the way for therapeutic applications. (authors). 18 refs., 6 figs., 1 tab

  11. Antibody discovery: sourcing of monoclonal antibody variable domains.

    Science.gov (United States)

    Strohl, William R

    2014-03-01

    Historically, antibody variable domains for therapeutic antibodies have been sourced primarily from the mouse IgG repertoire, and typically either chimerized or humanized. More recently, human antibodies from transgenic mice producing human IgG, phage display libraries, and directly from human B lymphocytes have been used more broadly as sources of antibody variable domains for therapeutic antibodies. Of the total 36 antibodies approved by major maket regulatory agencies, the variable domain sequences of 26 originate from the mouse. Of these, four are marketed as murine antibodies (of which one is a mouse-rat hybrid IgG antibody), six are mouse-human chimeric antibodies, and 16 are humanized. Ten marketed antibodies have originated from human antibody genes, three isolated from phage libraries of human antibody genes and seven from transgenic mice producing human antibodies. Five antibodies currently in clinical trials have been sourced from camelids, as well as two from non-human primates, one from rat, and one from rabbit. Additional sources of antibody variable domains that may soon find their way into the clinic are potential antibodies from sharks and chickens. Finally, the various methods for retrieval of antibodies from humans, mouse and other sources, including various display technologies and amplification directly from B cells, are described. PMID:24168292

  12. Radiolabelled antibodies in imaging

    International Nuclear Information System (INIS)

    Recent technological advances make it possible to produce pure (monoclonal) antibodies in unlimited quantities without the need for continuous immunization of animals and to label these antibodies with a variety of radionuclides which can be traced by single-photon computed tomography. An outline review of the state of the art is presented, with particular reference to the imaging of myocardial infarcts and to tumour imaging studies using labelled monoclonal antibodies (sup(99m)Tc and 125I). Lengthy bibliography. (U.K.)

  13. Anti-sulfotyrosine antibodies

    Science.gov (United States)

    Bertozzi, Carolyn R.; Kehoe, John; Bradbury, Andrew M.

    2009-09-15

    The invention provides anti-sulfotyrosine specific antibodies capable of detecting and isolating polypeptides that are tyrosine-sulfated. The sulfotyrosine antibodies and antibody fragments of the invention may be used to discriminate between the non-sulfated and sulfated forms of such proteins, using any number of immunological assays, such ELISAs, immunoblots, Western Blots, immunoprecipitations, and the like. Using a phage-display system, single chain antibodies (scFvs) were generated and screened against tyrosine-sulfated synthetic peptide antigens, resulting in the isolation of scFvs that specifically recognize sulfotyrosine-containing peptides and/or demonstrate sulfotyrosine-specific binding in tyrosine sulfated proteins. The VH and VL genes from one such sulfotyrosine-specific scFv were employed to generate a full length, sulfotyrosine-specific immunoglobulin.

  14. HIV Antibody Test

    Science.gov (United States)

    ... be limited. Home Visit Global Sites Search Help? HIV Antibody and HIV Antigen (p24) Share this page: Was this page helpful? Also known as: HIV Screening Tests; AIDS Test; AIDS Screen; HIV Serology; ...

  15. Antinuclear antibody panel

    Science.gov (United States)

    ... blood may be due to: Chronic liver disease Collagen vascular disease Drug-induced lupus erythematosus Myositis (inflammatory muscle disease) ... Saunders; 2011:chap 51. Read More Antibody Arthritis Collagen vascular disease Drug-induced lupus erythematosus Liver disease Scleroderma Systemic ...

  16. PRODUCTION OF MONOCLONAL ANTIBODIES

    Directory of Open Access Journals (Sweden)

    TOLKOVA E.S.

    2015-01-01

    Full Text Available The article considers the use of monoclonal antibodies in immunotherapy and immunodiagnostics of oncological diseases and their production using hybridoma technolody with flow diagram and technological scheme of manufacturing process

  17. PRODUCTION OF MONOCLONAL ANTIBODIES

    OpenAIRE

    TOLKOVA E.S.

    2015-01-01

    The article considers the use of monoclonal antibodies in immunotherapy and immunodiagnostics of oncological diseases and their production using hybridoma technolody with flow diagram and technological scheme of manufacturing process

  18. Expression of Recombinant Antibodies

    OpenAIRE

    Frenzel, André; Hust, Michael; Schirrmann, Thomas

    2013-01-01

    Recombinant antibodies are highly specific detection probes in research, diagnostics, and have emerged over the last two decades as the fastest growing class of therapeutic proteins. Antibody generation has been dramatically accelerated by in vitro selection systems, particularly phage display. An increasing variety of recombinant production systems have been developed, ranging from Gram-negative and positive bacteria, yeasts and filamentous fungi, insect cell lines, mammalian cells to transg...

  19. Prediction of antibody persistency from antibody titres to natalizumab

    DEFF Research Database (Denmark)

    Jensen, Poul Erik H; Koch-Henriksen, Nils; Sellebjerg, Finn; Sørensen, Per S

    2012-01-01

    In a subgroup of patients with multiple sclerosis natalizumab therapy causes generation of anti-natalizumab antibodies that may be transient or persistent. It is recommended to discontinue natalizumab therapy in persistently antibody-positive patients.......In a subgroup of patients with multiple sclerosis natalizumab therapy causes generation of anti-natalizumab antibodies that may be transient or persistent. It is recommended to discontinue natalizumab therapy in persistently antibody-positive patients....

  20. Prediction of Antibody Epitopes

    DEFF Research Database (Denmark)

    Nielsen, Morten; Marcatili, Paolo

    2015-01-01

    self-proteins. Given the sequence or the structure of a protein of interest, several methods exploit such features to predict the residues that are more likely to be recognized by an immunoglobulin.Here, we present two methods (BepiPred and DiscoTope) to predict linear and discontinuous antibody...

  1. Monoclonal antibodies in myeloma

    DEFF Research Database (Denmark)

    Sondergeld, P.; van de Donk, N. W. C. J.; Richardson, P. G.;

    2015-01-01

    The development of monoclonal antibodies (mAbs) for the treatment of disease goes back to the vision of Paul Ehrlich in the late 19th century; however, the first successful treatment with a mAb was not until 1982, in a lymphoma patient. In multiple myeloma, mAbs are a very recent and exciting add...

  2. Red Blood Cell Antibody Identification

    Science.gov (United States)

    ... limited. Home Visit Global Sites Search Help? RBC Antibody Identification Share this page: Was this page helpful? Also known as: Alloantibody Identification; Antibody ID, RBC; RBC Ab ID Formal name: Red ...

  3. Anti-insulin antibody test

    Science.gov (United States)

    Insulin antibodies - serum; Insulin Ab test ... Normally, there are no antibodies against insulin in your blood. Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or ...

  4. The Art of Making Antibodies.

    Science.gov (United States)

    Headon, Denis R.

    1986-01-01

    Provides background information for teachers on the nature and production of antibodies. Points out that the production of monoclonal antibodies blends the malignant with the beneficial to create a medical tool of exciting potential. (JN)

  5. Lupus anticoagulants and antiphospholipid antibodies

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/000547.htm Lupus anticoagulants and antiphospholipid antibodies To use the sharing features on this page, please enable JavaScript. Lupus anticoagulants are antibodies against substances in the lining ...

  6. Recombinant antibodies and tumor targeting

    OpenAIRE

    Sheikholvaezin, Ali

    2006-01-01

    Different antibody derived constructs are rapidly advancing as putative tools for treatment of malignant diseases. Antibody engineering has added significant new technologies to modify size, affinities, solubility, stability and biodistribution properties for immunoconjugates. In the present thesis, the aim was to increase our knowledge on how new recombinant antibodies could be tailored to optimize localization to experimental tumors in mice. One hybridoma, producing the monoclonal antibody ...

  7. Antibody Engineering and Therapeutics Conference

    OpenAIRE

    Larrick, James W; Parren, Paul WHI; Huston, James S; Plückthun, Andreas; Bradbury, Andrew; Tomlinson, Ian M; Chester, Kerry A.; Burton, Dennis R.; Adams, Gregory P; Weiner, Louis M.; Scott, Jamie K; Alfenito, Mark R; Veldman, Trudi; Reichert, Janice M

    2013-01-01

    The Antibody Engineering and Therapeutics conference, which serves as the annual meeting of The Antibody Society, will be held in Huntington Beach, CA from Sunday December 8 through Thursday December 12, 2013. The scientific program will cover the full spectrum of challenges in antibody research and development, and provide updates on recent progress in areas from basic science through approval of antibody therapeutics. Keynote presentations will be given by Leroy Hood (Institute of System Bi...

  8. Radiolabeled antibodies as imaging agents

    International Nuclear Information System (INIS)

    The author gives a survey of the progress made on radioimmunodetection. Antibodies may now be more readily used in scintigraphy as a result of the development of labeling methods that apply more suitable radionuclides without significant loss of the antigen-binding activity. Antibodies to tumor-specific or tumor-associated antigens can now be produced in large quantities by monoclonal antibody technology

  9. Antibody mimetics: promising complementary agents to animal-sourced antibodies.

    Science.gov (United States)

    Baloch, Abdul Rasheed; Baloch, Abdul Wahid; Sutton, Brian J; Zhang, Xiaoying

    2016-01-01

    Despite their wide use as therapeutic, diagnostic and detection agents, the limitations of polyclonal and monoclonal antibodies have inspired scientists to design the next generation biomedical agents, so-called antibody mimetics that offer many advantages over conventional antibodies. Antibody mimetics can be constructed by protein-directed evolution or fusion of complementarity-determining regions through intervening framework regions. Substantial progress in exploiting human, butterfly (Pieris brassicae) and bacterial systems to design and select mimetics using display technologies has been made in the past 10 years, and one of these mimetics [Kalbitor® (Dyax)] has made its way to market. Many challenges lie ahead to develop mimetics for various biomedical applications, especially those for which conventional antibodies are ineffective, and this review describes the current characteristics, construction and applications of antibody mimetics compared to animal-sourced antibodies. The possible limitations of mimetics and future perspectives are also discussed. PMID:25264572

  10. Monoclonal antibodies to Pneumocystis carinii

    DEFF Research Database (Denmark)

    Kovacs, J A; Halpern, J L; Lundgren, B; Swan, J C; Parrillo, J E; Masur, H

    1989-01-01

    To increase understanding of the antigenic structure of Pneumocystis carinii, we developed monoclonal antibodies to rat and human P. carinii. The specificity of the antibodies was demonstrated by immunofluorescence and immunoblot studies. Only one of five monoclonal antibodies to rat P. carinii...... reacted with human P. carinii, and none of four monoclonal antibodies to human P. carinii reacted with rat P. carinii. Two antibodies to human P. carinii reacted by immunofluorescence with only one human P. carinii isolate. Immunoblot studies identified major antigens of rat P. carinii with molecular...

  11. [Antibody therapy for Alzheimer's disease].

    Science.gov (United States)

    Tabira, Takeshi; Matsumoto, Shin-Ei; Jin, Haifeng

    2011-11-01

    In order to avoid Abeta-induced autoimmune encephalitis, several monoclonal and polyclonal antibodies are in clinical trials. These are bapineuzumab, solanezumab, ponezumab, gantenerumab, BAN2401, gammaguard and octagam. Since each antibody has a different antigen epitope of Abeta, anti-amyloid activities are different. It is unknown which antibody is effective for Alzheimer disease, and we must wait for the result of clinical trials. Some patients who developed tissue amyloid plaque immuno-reactive (TAPIR) antibody showed slower decline after AN-1792 vaccination. We developed TAPIR-like monoclonal antibody, which was found to react with Abeta oligomers preferentially. PMID:22277519

  12. Tabhu: tools for antibody humanization

    DEFF Research Database (Denmark)

    Olimpieri, Pier Paolo; Marcatili, Paolo; Tramontano, Anna

    2015-01-01

    and time-consuming experiments. Here we present tools for antibody humanization (Tabhu) a web server for antibody humanization. Tabhu includes tools for human template selection, grafting, back-mutation evaluation, antibody modelling and structural analysis, helping the user in all the critical steps......Antibodies are rapidly becoming essential tools in the clinical practice, given their ability to recognize their cognate antigens with high specificity and affinity, and a high yield at reasonable costs in model animals. Unfortunately, when administered to human patients, xenogeneic antibodies can...

  13. Monoclonal antibody as radiopharmaceutical

    International Nuclear Information System (INIS)

    The purification of anti-CEA monoclonal antibody 4C11 belonging to IgG sub(2a) subclass from mouse ascitis, donated by Ludwig Institute, Brazil was developed. The fragmentation of purified IgG sub(2a) by pepsin digestion and analytical studies by polyacrilamide gel electrophoresis in the presence of sodium dodecyl sulfate (SDS-PAGE) were done as preliminary assessment for their specific application in immunoscintigraphy. (author)

  14. Anticardiolipin antibodies in leptospirosis.

    OpenAIRE

    Rugman, F P; Pinn, G.; Palmer, M. F.; Waite, M.; Hay, C. R.

    1991-01-01

    The clinical course and serology of 16 cases of leptospirosis in an area with an unusually high endemic infection rate were studied to gain further insight into the pathology of the secondary immune phase that is typical of the disease. IgG anticardiolipin antibody concentrations were measured by immunoassay and found to be increased in eight serologically confirmed cases with severe complicated disease, compared with eight patients with relatively uncomplicated leptospirosis who had IgG anti...

  15. A monoclonal antibody against leptin.

    Science.gov (United States)

    Mahmoudian, Jafar; Jeddi-Tehrani, Mahmood; Bayat, Ali Ahmad; Mahmoudi, Ahmad Reza; Vojgani, Yasaman; Tavangar, Banafsheh; Hadavi, Reza; Zarei, Saeed

    2012-10-01

    Leptin is an important protein that regulates energy storage and homeostasis in humans and animals. Leptin deficiency results in various abnormalities such as diabetes, obesity, and infertility. Producing a high affinity monoclonal antibody against human leptin provides an important tool to monitor and trace leptin function in different biological fluids. In this study, recombinant human leptin was conjugated to KLH and injected into mice. After immunization, mouse myeloma SP2/0 cells were fused with murine splenocytes followed by selection of antibody-producing hybridoma cells. After screening of different hybridoma colonies by ELISA, a high affinity antibody was selected and purified by affinity chromatography. The affinity constant of the antibody was measured by ELISA. Western blot, immunocytochemistry, and flow cytometry experiments were used to characterize the antibody. The anti-leptin antibody had a high affinity (around 1.13 × 10(-9) M) for its antigen. The saturation of the antibody with leptin (20 moles leptin per 1 mole antibody) in Western blot analysis proved that the antibody had specific binding to its antigen. Immunocytochemistry and flow cytometry on JEG-3 (human placental choriocarcinoma cell) cells revealed that the anti-leptin antibody recognized intracellular leptin. In conclusion, we report here the production and characterization of a murine anti-leptin antibody with high affinity for human leptin. PMID:23098305

  16. Antiphospholipid Antibody and Antiphospholipid Syndrome

    Institute of Scientific and Technical Information of China (English)

    吴竞生

    2008-01-01

    @@ Antiphospholipid antibodies (APA) APA is a big category for all kinds of negative charge phospholipid or lecithin - a protein complex autoantibodies or the same antibody, through its recognition of antigen (target protein) different, and phospholipids or lecithin - protein complex combination of various rely on the interference Phospholipid clotting and anti-coagulation factor, and promote endothelial cells, platelets, complement activation and play a role. APA including lupus anticoagulant(LA) and anticardiolipin antibody (ACA), In addition, there are anti-β2 glycoprotein-I (β2-GPI) antibody, anti-prothrombin (a- PT) antibody, anti-lysophosphatidic acid antibody and anti-phosphatidylserine antibody, and so on. APA as the main target of phospholipid-binding protein, including β2-GPI, prothrombin, annexin, protein C (PC) and protein S (PS), plasminogen, and so on.

  17. Antibody therapy for Ebola

    Science.gov (United States)

    Qiu, Xiangguo; Kobinger, Gary P

    2014-01-01

    Ebola viruses can cause severe hemorrhagic fever in humans and nonhuman primates with fatality rates up to 90%, and are identified as biosafety level 4 pathogens and CDC Category A Agents of Bioterrorism. To date, there are no approved therapies and vaccines available to treat these infections. Antibody therapy was estimated to be an effective and powerful treatment strategy against infectious pathogens in the late 19th, early 20th centuries but has fallen short to meet expectations to widely combat infectious diseases. Passive immunization for Ebola virus was successful in 2012, after over 15 years of failed attempts leading to skepticism that the approach would ever be of potential benefit. Currently, monoclonal antibody (mAbs)-based therapies are the most efficient at reversing the progression of a lethal Ebola virus infection in nonhuman primates, which recapitulate the human disease with the highest similarity. Novel combinations of mAbs can even fully cure lethally infected animals after clinical symptoms and circulating virus have been detected, days into the infection. These new developments have reopened the door for using antibody-based therapies for filovirus infections. Furthermore, they are reigniting hope that these strategies will contribute to better control the spread of other infectious agents and provide new tools against infectious diseases. PMID:24503566

  18. Second antibody clearance of radiolabeled antibody in cancer radioimmunodetection.

    OpenAIRE

    Sharkey, R M; Primus, F J; Goldenberg, D. M.

    1984-01-01

    The imaging of tumors using radiolabeled antibodies previously has required the implementation of computer-assisted subtraction techniques to reduce background radioactivity. A decrease in radioactivity in the blood of hamsters bearing human colonic tumor xenografts has been achieved by administering a second antibody directed against a radiolabeled primary antibody to carcinoembryonic antigen (CEA). This method was found to reduce the level of blood radioactivity by a factor of 4 within 2 hr...

  19. Antibody Glossary —

    Science.gov (United States)

    The components of the immune system have diverse roles in the initial development of cancers, progression of early-stage malignancies to invasive tumors, establishment of metastatic lesions, tumor dormancy, and response or resistance to therapy. Characterizing the components of the immune system and their functional status in tissues and in tumors requires the use of highly specific reagents. Researchers employ antibodies in a variety of in vitro and in vivo applications to delineate, enrich, or deplete specific immune subsets in order to understand their role(s) in tumorigenesis. This is a glossary of validated reagents and protocols that are useful for functional phenotyping of the immune system in murine cancer models.

  20. The antibody Hijikata Tatsumi

    Directory of Open Access Journals (Sweden)

    Éden Peretta

    2012-11-01

    Full Text Available Considered one of the most influential modern dance representatives in Japan, Tatsumi Hijikata’s work was a milestone in the Japanese post-war experimental artistic scene. Heretic son of his time, he staged a fertile mix of artistic and cultural influences, overlapping subversive elements of European arts and philosophy with radical references from pre-modern Japanese culture. In this way he built the foundations of its unstable antibody, its political-artistic project of dissolution of a organism, both physical and social.

  1. VIRAL ANTIBODIES IN PRESCHOOL CHILDREN

    Directory of Open Access Journals (Sweden)

    S. Saidi

    1974-08-01

    Full Text Available One hundred sera from children 1 - 6 years of age, representative of a large serum collection, were tested for the prevalence of antibodies against different viruses. Hemagglutination-inhibition (HI antibodies were found in 68% for measles; 61 % for rubella; 75'% for influenza A2/Hong Kong/68, 16% for influenza B/Md./59, 0% for group A arboviruses, 10% for group B arboviruses, 3% for phlebotomus fever group and 4% for Congo-Crimean hemorrhagic fever (C-CHF group of arboviruses Poliomyelitis-neutralizing antibodies for type 1, 2 and 3 were 90%; 85% and 84%~ respectively. Antibody to EH virus was detected in 84% of the sera by immuno-fluorescence. None of the sera were positive for hepatitis-B antigen or antibody by immuno-precipitation test. The prevalence of some viral antibodies found in this survey are compared with results obtained from surveys in other parts of the country.

  2. Antibodies to watch in 2015

    OpenAIRE

    Reichert, Janice M

    2014-01-01

    The commercial pipeline of recombinant antibody therapeutics is robust and dynamic. As of early December 2014, a total of 6 such products (vedolizumab, siltuximab, ramucirumab, pembrolizumab, nivolumab, blinatumomab) were granted first marketing approvals in 2014. As discussed in this perspective on antibodies in late-stage development, the outlook for additional approvals, potentially still in 2014 and certainly in 2015, is excellent as marketing applications for 6 antibody therapeutics (sec...

  3. Monoclonal antibodies for treating cancer

    International Nuclear Information System (INIS)

    The purpose of this study is to assess the current status of in-vivo use of monoclonal antibodies for treating cancer. Publications appearing between 1980 and 1988 were identified by computer searches using MEDLINE and CANCERLIT, by reviewing the table of contents of recently published journals, and by searching bibliographies of identified books and articles. More than 700 articles, including peer-reviewed articles and book chapters, were identified and selected for analysis. The literature was reviewed and 235 articles were selected as relevant and representative of the current issues and future applications for in-vivo monoclonal antibodies for cancer therapy and of the toxicity and efficacy which has been associated with clinical trials. Approaches include using antibody alone (interacting with complement or effector cells or binding directly with certain cell receptors) and immunoconjugates (antibody coupled to radioisotopes, drugs, toxins, or other biologicals). Most experience has been with murine antibodies. Trials of antibody alone and radiolabeled antibodies have confirmed the feasibility of this approach and the in-vivo trafficking of antibodies to tumor cells. However, tumor cell heterogeneity, lack of cytotoxicity, and the development of human antimouse antibodies have limited clinical efficacy. Although the immunoconjugates are very promising, heterogeneity and the antimouse immune response have hampered this approach as has the additional challenge of chemically or genetically coupling antibody to cytotoxic agents. As a therapeutic modality, monoclonal antibodies are still promising but their general use will be delayed for several years. New approaches using human antibodies and reducing the human antiglobulin response should facilitate treatment. 235 references

  4. Metrics for antibody therapeutics development

    OpenAIRE

    Reichert, Janice M

    2010-01-01

    A wide variety of full-size monoclonal antibodies (mAbs) and therapeutics derived from alternative antibody formats can be produced through genetic and biological engineering techniques. These molecules are now filling the preclinical and clinical pipelines of every major pharmaceutical company and many biotechnology firms. Metrics for the development of antibody therapeutics, including averages for the number of candidates entering clinical study and development phase lengths for mAbs approv...

  5. Empowered Antibody Therapies - IBC conference.

    Science.gov (United States)

    Herold, Jens

    2010-10-01

    The Empowered Antibody Therapies conference, held in Burlingame, CA, USA, included topics covering new therapeutic developments in the field of multispecific antibodies. This conference report highlights selected presentations on DVD-Igs from Abbott Laboratories, ImmTACs from Immunocore, 'Dock-and-Lock' technology from Immunomedics, the bispecific BiTE antibody blinatumomab from Micromet, and Triomabs from TRION Pharma and Fresenius Biotech. PMID:20878591

  6. Antibody informatics for drug discovery

    DEFF Research Database (Denmark)

    Shirai, Hiroki; Prades, Catherine; Vita, Randi;

    2014-01-01

    infrastructure for these large data sets has become necessary. In this article, we first identify and discuss the typical obstacles faced during the antibody drug discovery process. We then summarize the current status of three sub-fields of antibody informatics as follows: (i) recent progress in technologies...... (iii) antibody numbering and IMGT. Here, we review “antibody informatics,” which may integrate the above three fields so that bridging the gaps between industrial needs and academic solutions can be accelerated. This article is part of a Special Issue entitled: Recent advances in molecular engineering...

  7. Tumor imaging with monoclonal antibodies

    International Nuclear Information System (INIS)

    Many monoclonal antibodies directed against tumor-associated antigens have been identified, but so far none of these are tumor specific. Polyclonal and monoclonal antibodies have been used for imaging of a wide variety of tumors with success. Radiolabeling of antibody is usually done with iodine isotopes of which 123I is the best candidate for radioimmunodetection purposes. The labeling of antibodies through chelates makes it possible to use metal radioisotopes like 111In, which is the best radioisotope for imaging with monoclonal antibodies due to its favorable half-life of 2.5 days. Usually imaging cannot be performed within 24 h after injection, but clearance of antibody can be increased by using F(ab)2 of Fab. Another approach is to clear non-bound antibody by a second antibody, directed against the first. The detection limit of immunoimaging is about 2 cm, but will be improved by tomography or SPECT. There is still a high false positive and false negative rate, which makes it impossible to use radioimmunodetection as the only technique for diagnosis of tumors. In combination with other detection techniques, tumor imaging with monoclonal antibodies can improve diagnosis. 44 refs.; 3 tabs

  8. Creating Ordered Antibody Arrays with Antibody-Polymer Conjugates

    Science.gov (United States)

    Dong, Xuehui; Obermeyer, Allie; Olsen, Bradley

    Antibodies are a category of functional proteins that play crucial roles in the immune system and have been widely applied in the area of cancer therapeutics, targeting delivery, signal detection, and sensors. Due to the extremely large size and lack of specific functional groups on the surface, it is challenging to functionalize antibodies and manipulate the ordered packing of antibodies in an array with high density and proper orientation, which is critical to achieve outstanding performance in materials. In this work, we demonstrate an efficient and facile approach for preparing antibody-polymer conjugates with two-step sequential ``click'' reaction to form antibody-polymer block copolymers. Highly ordered nanostructures are fabricated based on the principles of block copolymer self-assembly. The nanostructures are studied with both small angle X-ray scattering (SAXS) and transmission electron microscopy (TEM). Lamellae with alternating antibody domain and polymer domain are observed with an overall domain size of ~50 nm. The nanostructure not only increases the packing density and promotes proper orientation of the antibody, but also provides possible channel to facilitate substrate transportation and improves the stability of the antibody.

  9. Evaluación de las propiedades luminiscentes y detección de Eu2+ en partículas nanoestructuradas del sistema Gd2-xEuxO3 (x= 0.05, 0.10 y 0.30)

    OpenAIRE

    Barroso, I.; Mena, I.; Gómez, L. S.; Milosevic, O.; Rabanal, M. Eugenia

    2012-01-01

    [ES] Mediante el método de Spray Pirólisis (SP) operando a 700ºC y en atmósfera de aire seco, se obtuvieron partículas nanoestructuradas de composición Gd2-xEuxO3 (x= 0.05, 0.10 y 0.30) partiendo de las respectivas disoluciones acuosas de nitratos (0.1M). En el presente trabajo, se estudiaron tres muestras con distinta concentración de europio correspondiente al 1, 2 y 6% atómico. Posteriormente, las partículas nanoestructuradas obtenidas se sometieron a distintos tratamientos térmic...

  10. State-of-the-art flux pinning in YBa2Cu3O7-δ by the creation of highly linear, segmented nanorods of Ba2(Y /Gd)(Nb/Ta)O6 together with nanoparticles of (Y /Gd)2O3 and (Y /Gd)Ba2Cu4O8

    International Nuclear Information System (INIS)

    Self-assembled, segmented nanorods of c-axis-aligned Ba2(Y /Gd)(Nb/Ta)O6 as well as randomly distributed nanoparticles of (Y /Gd)2O3 and (Y /Gd)Ba2Cu4O8 were grown into YBa2Cu3O7-δ (YBCO) thin films by pulsed-laser deposition. The complex pinning landscape proves to be extremely effective, particularly at higher fields where the segmented vortices yield a plateau in critical current density (Jc) with field angle around 600. In 0.3 μm thick films, the Jc values are higher than 1 MA cm-2 at 2.5 T (H||c axis). Owing to the combined interactions of the vortices with the different pinning centres, interesting new features are observed at high fields in the angular dependence of Jc.

  11. Antiphospholipid antibodies and infertility.

    Science.gov (United States)

    Chighizola, C B; de Jesus, G R

    2014-10-01

    Since the late 1980s some publications have proposed that antiphospholipid antibodies (aPL) may have some relationship with infertility, considering reported deleterious effects that aPL exert on trophoblast proliferation and growth. Although not included in current classification criteria for antiphospholipid syndrome, many physicians investigate for aPL in patients with a history of infertility, including antibodies not listed in classification criteria, and most of those patients will receive anticoagulant therapy if any of those antibodies have a result considered positive. A review of literature was conducted searching for studies that investigated the association of aPL and infertility and if aPL positivity alters in vitro fertilization (IVF) outcome. The definition of infertility, routine work-up to exclude other causes of infertility, definition of IVF failure as inclusion criteria and control populations were heterogeneous among studies. Most of them enrolled women over 40 years of age, and exclusion of other confounding factors was also inconsistent. Of 29 studies that assessed aPL positivity rates in infertile women, the majority had small sample sizes, implying a lack of power, and 13 (44.8%) reported higher frequency of aPL in infertile patients compared to controls, but most of them investigated a panel of non-criteria aPL tests, whose clinical significance is highly controversial. Only two studies investigated all three criteria tests, and medium-high titer of anticardiolipin cut-off conforming to international guidelines was used in one study. Considering IVF outcome, there was also disparity in this definition: few studies assessed the live birth rate, others the implantation rate. Of 14 publications that addressed the relationship between aPL and IVF outcome, only two described a detrimental effect of these autoantibodies. In conclusion, available data do not support an association between aPL and infertility, and aPL positivity does not seem to

  12. Targeting of Antibodies using Aptamers

    OpenAIRE

    Missailidis, Sotiris

    2003-01-01

    The chapter presents a methodology for the rapid selection of aptamers against antibody targets. It is a detailed account of the various methodological steps that describe the selection of aptamers, including PCR steps, buffers to be used, target immobilisation, partitioning and amplification of aptamers, clonning and sequencing, to results in high affinity and specificity ligands for the chosen target antibody.

  13. Refolding Technologies for Antibody Fragments

    OpenAIRE

    Tsutomu Arakawa; Daisuke Ejima

    2014-01-01

    Refolding is one of the production technologies for pharmaceutical grade antibody fragments. Detergents and denaturants are primarily used to solubilize the insoluble proteins. The solubilized and denatured proteins are refolded by reducing the concentration of the denaturants or detergents. Several refolding technologies have been used for antibody fragments, comprising dilution, dialysis, solid phase solvent exchange and size exclusion chromatography, as reviewed here. Aggregation suppresso...

  14. ANTISPERM ANTIBODIES IN VASOVASOSTOMY

    Directory of Open Access Journals (Sweden)

    Gholamreza Pourmand

    1993-06-01

    Full Text Available Two hundred and forty patients, who had undergone vasectomy from 1977 to 1985 and subsequent vasovasostomy ,were studied for the presence of sperm-specific antibodies by using the Kibrick's gelatin agglutination test. The number of successful pregnancies and the presence of agglutination were also considered in this survey. Sixty-nine pregnancies occurred in total and agglutination was present in 49% out of 51% positive specimens by the Kibrick Test."nThe average sperm motility was slightly higher in the negative Kibrick group than in the positive Kibrick group. The obtained data indicated that there seems to be a relationship between the increased titers and percentage of agglutination in semen samples.

  15. Metrics for antibody therapeutics development.

    Science.gov (United States)

    Reichert, Janice M

    2010-01-01

    A wide variety of full-size monoclonal antibodies (mAbs) and therapeutics derived from alternative antibody formats can be produced through genetic and biological engineering techniques. These molecules are now filling the preclinical and clinical pipelines of every major pharmaceutical company and many biotechnology firms. Metrics for the development of antibody therapeutics, including averages for the number of candidates entering clinical study and development phase lengths for mAbs approved in the United States, were derived from analysis of a dataset of over 600 therapeutic mAbs that entered clinical study sponsored, at least in part, by commercial firms. The results presented provide an overview of the field and context for the evaluation of on-going and prospective mAb development programs. The expansion of therapeutic antibody use through supplemental marketing approvals and the increase in the study of therapeutics derived from alternative antibody formats are discussed. PMID:20930555

  16. Epstein-Barr virus antibody test

    Science.gov (United States)

    EBV antibody test; EBV serology ... a lab, where a lab specialist looks for antibodies to the Epstein-Barr virus. In the first stages of an illness, little antibody may be detected. For this reason, the test ...

  17. Measurement of antibodies to tubulin by radioimmunoassay

    International Nuclear Information System (INIS)

    A solid-phase double antibody radioimmunoassay capable of measuring antibody to tubulin, the principal component of microtubules, is described. This assay is simple, combining sensitivity with specificity and also allowing determination of antibody subclasses. (Auth.)

  18. Antibodies - Office of Cancer Clinical Proteomics Research

    Science.gov (United States)

    NCI announces the release of monoclonal antipeptide antibodies from rabbit for distribution on the antibody portal. There are 60 recently added monoclonal antibodies, with 56 generated from mouse and 4 generated from rabbit.

  19. Antibody fragments: Hope and hype

    OpenAIRE

    Nelson, Aaron L

    2010-01-01

    The antibody molecule is modular and separate domains can be extracted through biochemical or genetic means. It is clear from review of the literature that a wave of novel, antigen-specific molecular forms may soon enter clinical evaluation. This report examines the developmental histories of therapeutics derived from antigen-specific fragments of antibodies produced by recombinant processes. Three general types of fragments were observed, antigen-binding fragments (Fab), single chain variabl...

  20. Functional effects of anticardiolipin antibodies.

    Science.gov (United States)

    Harris, E N; Pierangeli, S S

    1996-10-01

    The 'lupus anticoagulant' phenomenon is the best documented functional effect of antiphospholipid (aPL) antibodies, occurring either by inhibition of the prothrombinase and/or Factor X activation reactions. Understanding the mechanism by which aPL antibodies inhibit phospholipid dependent coagulation reactions may yield important clues about their 'thrombogenic effects' in vivo. We conducted a series of studies to determine the specificity, diversity, and mechanism by which aPL antibodies inhibit phospholipid dependent reactions. Results showed that purified immunoglobulins with lupus anticoagulant and anti-cardiolipin activities were absorbed by negatively charged phospholipids and both activities were recovered from the phospholipid-antibody precipitate. Purified aPL antibodies inhibited the prothrombinase reaction in a plasma free system in which beta 2-glycoprotein 1 (beta 2-GP1) was absent. Affinity purified aPL antibodies had 25-50 times the inhibitory activity of immunoglobulin preparations. The phospholipid binding proteins, beta 2-GPI and placental anticoagulant protein I (PAP I), independently inhibited the prothrombinase reaction, and when these proteins were combined with aPL, inhibition of the prothrombinase reaction was additive. Antibodies of syphilis had no inhibitory effect, partially accounted for by lack of specificity for phosphotidylserine (PS). Although aPL antibodies inhibited the protein C activation reaction, there was no correlation of these activities with inhibition of the prothrombinase reaction. Together, these results show that aPL exert their effects by interaction with negatively charged phospholipids, in particular phosphotidylserine, but lack of correlation between inhibition of the prothrombinase and protein C activation reactions, suggests that the nature of the coagulation protein is also important. PMID:8902763

  1. The antineutrophil antibody in uveitis.

    OpenAIRE

    Young, D W

    1991-01-01

    Ninety eight patients with uveitis of various types were tested for the presence of the antineutrophil antibody or ANCA by an indirect immunofluorescence method. This antibody is found in patients with diseases associated with small vessel vasculitis, including Wegener's granulomatosis and microscopic polyarteritis. Eleven true positive cases were found. A positive test was not associated with the anatomical site of the uveitis but was related to the time course of the disease. In particular ...

  2. Interfacial metal and antibody recognition

    OpenAIRE

    Zhou, Tongqing; Hamer, Dean H.; Hendrickson, Wayne A.; Sattentau, Quentin J.; Kwong, Peter D.

    2005-01-01

    The unique ligation properties of metal ions are widely exploited by proteins, with approximately one-third of all proteins estimated to be metalloproteins. Although antibodies use various mechanisms for recognition, to our knowledge, none has ever been characterized that uses an interfacial metal. We previously described a family of CD4-reactive antibodies, the archetype being Q425. CD4:Q425 engagement does not interfere with CD4:HIV-1 gp120 envelope glycoprotein binding, but it blocks subse...

  3. Pyoderma gangrenosum and anticardiolipin antibody

    Directory of Open Access Journals (Sweden)

    de Godoy Jose Maria

    2006-01-01

    Full Text Available Pyoderma gangrenosum (PG is a rare ulceronecrotic inflammatory cutaneous disorder and is frequently associated with systemic diseases. The authors report a 22-year-old male patient with pyoderma gangrenosum, thrombosis of both popliteal arteries, ischemic stroke and seropositivity for anticardiolipin antibody. Despite intravenous treatment with antibiotics, corticosteroid and heparin, pyoderma gangrenosum caused necrosis of his right lower limb which resulted in amputation. It was concluded that the anticardiolipin antibody may have contributed to the gravity of this case.

  4. Antibodies to watch in 2014.

    Science.gov (United States)

    Reichert, Janice M

    2014-01-01

    Since 2010, mAbs has documented the biopharmaceutical industry's progress in transitioning antibody therapeutics to first Phase 3 clinical studies and regulatory review, and its success at gaining first marketing approvals for antibody-based products. This installment of the "Antibodies to watch" series outlines events anticipated to occur between December 2013 and the end of 2014, including first regulatory actions on marketing applications for vedolizumab, siltuximab, and ramucirumab, as well as the Fc fusion proteins Factor IX-Fc and Factor VIII-Fc; and the submission of first marketing applications for up to five therapeutics (secukinumab, ch14.18, onartuzumab, necitumumab, gevokizumab). Antibody therapeutics in Phase 3 studies are described, with an emphasis on those with study completion dates in 2014, including antibodies targeting interleukin-17a or the interleukin-17a receptor (secukinumab, ixekizumab, brodalumab), proprotein convertase subtilisin/kexin type 9 (alirocumab, evolocumab, bococizumab), and programmed death 1 receptor (lambrolizumab, nivolumab). Five antibodies with US Food and Drug Administration's Breakthrough Therapy designation (obinutuzumab, ofatumumab, lambrolizumab, bimagrumab, daratumumab) are also discussed. PMID:24284914

  5. Tabhu: tools for antibody humanization.

    KAUST Repository

    Olimpieri, Pier Paolo

    2014-10-09

    SUMMARY: Antibodies are rapidly becoming essential tools in the clinical practice, given their ability to recognize their cognate antigens with high specificity and affinity, and a high yield at reasonable costs in model animals. Unfortunately, when administered to human patients, xenogeneic antibodies can elicit unwanted and dangerous immunogenic responses. Antibody humanization methods are designed to produce molecules with a better safety profile still maintaining their ability to bind the antigen. This can be accomplished by grafting the non-human regions determining the antigen specificity into a suitable human template. Unfortunately, this procedure may results in a partial or complete loss of affinity of the grafted molecule that can be restored by back-mutating some of the residues of human origin to the corresponding murine ones. This trial-and-error procedure is hard and involves expensive and time-consuming experiments. Here we present tools for antibody humanization (Tabhu) a web server for antibody humanization. Tabhu includes tools for human template selection, grafting, back-mutation evaluation, antibody modelling and structural analysis, helping the user in all the critical steps of the humanization experiment protocol. AVAILABILITY: http://www.biocomputing.it/tabhu CONTACT: anna.tramontano@uniroma1.it, pierpaolo.olimpieri@uniroma1.it SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

  6. Avian Diagnostic and Therapeutic Antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Bradley, David Sherman [UND SMHS

    2012-12-31

    A number of infectious agents have the potential of causing significant clinical symptomology and even death, but dispite this, the number of incidence remain below the level that supports producing a vaccine. Therapeutic antibodies provide a viable treatment option for many of these diseases. We proposed that antibodies derived from West Nile Virus (WNV) immunized geese would be able to treat WNV infection in mammals and potential humans. We demonstrated that WNV specific goose antibodies are indeed successful in treating WNV infection both prophylactically and therapeutically in a golden hamster model. We demonstrated that the goose derived antibodies are non-reactogenic, i.e. do not cause an inflammatory response with multiple exposures in mammals. We also developed both a specific pathogen free facility to house the geese during the antibody production phase and a patent-pending purification process to purify the antibodies to greater than 99% purity. Therefore, the success of these study will allow a cost effective rapidly producible therapeutic toward clinical testing with the necessary infrastructure and processes developed and in place.

  7. Radiolabeled monoclonal antibodies: a review

    International Nuclear Information System (INIS)

    Since the description by Kohler and Milstein 1975 of their technique for producing monoclonal antibodies of predefined specificity, it has become a mainstay in most laboratories that utilize immunochemical techniques to study problems in basic, applied or clinical research. Paradoxically, the very success of monoclonal antibodies has generated a literature which is now so vast and scattered that it has become difficult to obtain a perspective. This brief review represents the distillation of many publications relating to the production and use of monoclonaal antibodies as radiopharmaceuticals. Significant advances were made possible in the last few years by combined developments in the fields of tumor-associated antigens and of monoclonal antibodies. In fact monoclonal antibodies against some well defined tumor-associated antigens, has led to significantly greater practical possibilities for producing highly specific radiolabeled antibodies as radiopharmaceuticals for diagnosis and therapy of human tumors. One of the main requirements of this methodology is the availability of stable radiopharmaceutical reagents which after labeling in vivo injection retain the capacity of specific interaction with the defined antigen and their molecular integrity. Since injection into human is the objetive of this kind of study all the specifications of radiopharmaceutical have to be fulfilled e.g. sterility, apirogenicity and absence of toxicity. (author)

  8. Radioimmunoguided surgery using monoclonal antibody

    International Nuclear Information System (INIS)

    The potential proficiency of radioimmunoguided surgery in the intraoperative detection of tumors was assessed using labeled monoclonal antibody B72.3 in 66 patients with tissue-proved tumor. Monoclonal antibody B72.3 was injected 5 to 42 days preoperatively, and the hand-held gamma-detecting probe was used intraoperatively to detect the presence of tumor. Intraoperative probe counts of less than 20 every 2 seconds, or tumor-to-adjacent normal tissue ratios less than 2:1 were considered negative (system failure). Positive probe counts were detected in 5 of 6 patients with primary colon cancer (83 percent), in 31 of 39 patients with recurrent colon cancer (79 percent), in 4 of 5 patients with gastric cancer (80 percent), in 3 of 8 patients with breast cancer (37.5 percent), and in 4 of 8 patients with ovarian cancer (50 percent) undergoing second-look procedures. Additional patients in each group were scored as borderline positive. Overall, radioimmunoguided surgery using B72.3 identified tumors in 47 patients (71.2 percent), bordered on positive in 6 patients (9.1 percent), and failed to identify tumor in 13 patients (19.7 percent). Improved selection of patients for antigen-positive tumors, the use of higher affinity second-generation antibodies, alternate routes of antibody administration, alternate radionuclides, and more sophisticatedly bioengineered antibodies and antibody combinations should all lead to improvements in radioimmunoguided surgery

  9. Monoclonal antibodies technology. Protocols

    International Nuclear Information System (INIS)

    Full text: Immunization. The first step in preparing useful monoclonal antibodies (MAbs) is to immunize an animal (Balb/c for example) with an appropriate antigen. Methods (only for soluble antigen): Solubilize selected antigen in Phosphate buffer solution (PBS) at pH 7.2-7.4, ideally at a final concentration per animal between 10 to 50 μg/ml. It is recommended that the antigen under consideration be incorporated into the emulsion adjuvants in 1:1 volumetric relation. We commonly use Frend's adjuvant (FA) to prepared immunized solution. The first immunization should be prepared with complete FA, and the another could be prepared with incomplete FA. It is recommended to inject mice with 0.2 ml intraperitoneal (ip) or subcutaneous (sc). Our experience suggests the sc route is the preferred route. A minimum protocol for immunizing mice to generate cells for preparing hybridomas is s follows: immunize sc on day 0, boost sc on day 21, take a trial bleeding on day 26; if antibody titters are satisfactory, boost ip on day 35 with antigen only, and remove the spleen to obtain cells for fusion on day 38. Fusion protocol. The myeloma cell line we are using is X63 Ag8.653. At the moment of fusion myeloma cells need a good viability (at least a 95%). 1. Remove the spleen cells from immunized mice using sterile conditions. An immune spleen should yield between 7 a 10x107 nucleated cells. 2. Place the spleen in 20 ml of serum-free RPMI 1640 in a Petri dish. Using a needle and syringe, inject the spleen with medium to distend and disrupt the spleen stroma and free the nucleated cells. 3. Flush the cell suspension with a Pasteur pipet to disperse clumps of cells. 4. Centrifuge the spleen cell suspension at 250g for 10 min. Resuspend the pellet in serum-free RPMI 1640. Determine cell concentration using Neuhabuer chamber. 5. Mix the myeloma cells and spleen cells in a conical 50-ml tube in serum-free RPMI 1640, 1 x107 spleen cells to 1x106 myeloma cells (ratio 10:1). Centrifuge

  10. Production of recombinant antibodies using bacteriophages

    OpenAIRE

    Shukra, A. M.; Sridevi, N. V.; Dev Chandran,; Kapil Maithal,

    2014-01-01

    Recombinant antibody fragments such as Fab, scFv, diabodies, triabodies, single domain antibodies and minibodies have recently emerged as potential alternatives to monoclonal antibodies, which can be engineered using phage display technology. These antibodies match the strengths of conventionally produced monoclonal antibodies and offer advantages for the development of immunodiagnostic kits and assays. These fragments not only retain the specificity of the whole monoclonal ...

  11. Antibody-Directed Phototherapy (ADP

    Directory of Open Access Journals (Sweden)

    M. Adil Butt

    2013-04-01

    Full Text Available Photodynamic therapy (PDT is a clinically-approved but rather under-exploited treatment modality for cancer and pre-cancerous superficial lesions. It utilises a cold laser or LED to activate a photochemical reaction between a light activated drug (photosensitiser-drug and oxygen to generate cytotoxic oxygen species. These free radical species damage cellular components leading to cell death. Despite its benefits, the complexity, limited potency and side effects of PDT have led to poor general usage. However, the research area is very active with an increasing understanding of PDT-related cell biology, photophysics and significant progress in molecular targeting of disease. Monoclonal antibody therapy is maturing and the next wave of antibody therapies includes antibody-drug conjugates (ADCs, which promise to be more potent and curable. These developments could lift antibody-directed phototherapy (ADP to success. ADP promises to increase specificity and potency and improve drug pharmacokinetics, thus delivering better PDT drugs whilst retaining its other benefits. Whole antibody conjugates with first generation ADP-drugs displayed problems with aggregation, poor pharmacokinetics and loss of immuno-reactivity. However, these early ADP-drugs still showed improved selectivity and potency. Improved PS-drug chemistry and a variety of conjugation strategies have led to improved ADP-drugs with retained antibody and PS-drug function. More recently, recombinant antibody fragments have been used to deliver ADP-drugs with superior drug loading, more favourable pharmacokinetics, enhanced potency and target cell selectivity. These improvements offer a promise of better quality PDT drugs.

  12. Antibodies to watch in 2016.

    Science.gov (United States)

    Reichert, Janice M

    2016-01-01

    The number of novel antibody therapeutics that received first marketing approvals in 2015 met expectations, with 6 (alirocumab (Praluent®), evolocumab (Repatha®), daratumumab (Darzalex®), dinutuximab (Unituxin®), idarucizumab (Praxbind®), mepolizumab (Nucala®)) granted first approvals as of mid-November*. Seven novel antibody therapeutics (begelomab, brodalumab, elotuzumab, ixekizumab, necitumumab, obiltoxaximab, reslizumab) are in regulatory review, and thus a similar number, if not more, are projected to gain first approvals in 2016. Commercial late-stage antibody therapeutics development exceeded expectations by increasing from 39 candidates in Phase 3 studies as of late 2014 to 53 as of late 2015. Of the 53 candidates, transitions to regulatory review by the end of 2016 are projected for 8 (atezolizumab, benralizumab, bimagrumab, durvalumab, inotuzumab ozogamicin, lebrikizumab, ocrelizumab, tremelimumab). Other "antibodies to watch" include 15 candidates (bavituximab, bococizumab, dupilumab, fasinumab, fulranumab, gevokizumab, guselkumab, ibalizumab, LY2951742, onartuzumab, REGN2222, roledumab, romosozumab, sirukumab, Xilonix) undergoing evaluation in Phase 3 studies that have estimated primary completion dates in 2016. As evidenced by the antibody therapeutics discussed in this perspective, the biopharmaceutical industry has a highly active late-stage clinical pipeline that may deliver numerous new products to the global market in the near future. *See Note added in proof for updates through December 31, 2015. PMID:26651519

  13. Uses of monoclonal antibody 8H9

    Science.gov (United States)

    Cheung, Nai-Kong V.

    2013-04-09

    This invention provides a composition comprising an effective amount of monoclonal antibody 8H9 or a derivative thereof and a suitable carrier. This invention provides a pharmaceutical composition comprising an effective amount of monoclonal antibody 8H9 or a derivative thereof and a pharmaceutically acceptable carrier. This invention also provides an antibody other than the monoclonal antibody 8H9 comprising the complementary determining regions of monoclonal antibody 8H9 or a derivative thereof, capable of binding to the same antigen as the monoclonal antibody 8H9. This invention provides a substance capable of competitively inhibiting the binding of monoclonal antibody 8H9. This invention also provides an isolated scFv of monoclonal antibody 8H9 or a derivative thereof. This invention also provides the 8H9 antigen. This invention also provides different uses of the monoclonal antibody 8H9 or its derivative.

  14. Autologous antibodies that bind neuroblastoma cells.

    Science.gov (United States)

    Sun, Yujing; Sholler, Giselle S; Shukla, Girja S; Pero, Stephanie C; Carman, Chelsea L; Zhao, Ping; Krag, David N

    2015-11-01

    Antibody therapy of neuroblastoma is promising and our goal is to derive antibodies from patients with neuroblastoma for developing new therapeutic antibodies. The feasibility of using residual bone marrow obtained for clinical indications as a source of tumor cells and a source of antibodies was assessed. From marrow samples, neuroblastoma cells were recovered, grown in cell culture and also implanted into mice to create xenografts. Mononuclear cells from the marrow were used as a source to generate phage display antibody libraries and also hybridomas. Growth of neuroblastoma patient cells was possible both in vitro and as xenografts. Antibodies from the phage libraries and from the monoclonal hybridomas bound autologous neuroblastoma cells with some selectivity. It appears feasible to recover neuroblastoma cells from residual marrow specimens and to generate human antibodies that bind autologous neuroblastoma cells. Expansion of this approach is underway to collect more specimens, optimize methods to generate antibodies, and to evaluate the bioactivity of neuroblastoma-binding antibodies. PMID:26210205

  15. Antisperm antibodies and in vitro fertilization.

    Science.gov (United States)

    Janssen, H J; Bastiaans, B A; Goverde, H J; Hollanders, H M; Wetzels, A A; Schellekens, L A

    1992-08-01

    The purpose of this study was to investigate the influence of antisperm antibodies in the male, the female, or both partners on the outcome of in vitro fertilization treatment. The results in terms of ongoing pregnancies in the male and female antibody-positive group were the same as in the antibody-negative group. In the double antibody-positive group two of the three patients became pregnant. When high levels of antisperm antibodies were present on the spermatozoa, the fertilization rate was significantly reduced. In the female positive group no clear relationship between the antibody titer and the fertilization percentage could be detected. Abnormal semen quality was responsible for a much lower fertilization rate than the presence of antibodies. The conclusion of this study is that in vitro fertilization provides an equal change of conception in couples with antisperm antibodies in comparison with couples with no antibodies if the other semen parameters are normal. PMID:1472812

  16. Remembering antibodies coming of age.

    Science.gov (United States)

    Melchers, Fritz

    2016-01-01

    Fifty years ago, Norbert Hilschmann discovered that antibodies have variable immunoglobulin domains to bind antigens, and constant domains to carry out effector functions in the immune system. Just as this happened, the author of this perspective entered the field of immunology. Ten years later, the genetic basis of antibody variability was discovered by Susumu Tonegawa and his colleagues at the Basel Institute for Immunology, where the author had become a scientific member. At the same time, Georges Köhler, a former graduate student of the author's at the Basel Institute, invented with Cesar Milstein at the Laboratory of Molecular Biology in Cambridge, England, the method to produce monoclonal antibodies. The author describes here his memories connected to these three monumental, paradigm-changing discoveries, which he observed in close proximity. PMID:27144253

  17. Molecular-specific urokinase antibodies

    Science.gov (United States)

    Atassi, M. Zouhair (Inventor); Morrison, Dennis R. (Inventor)

    2009-01-01

    Antibodies have been developed against the different molecular forms of urokinase using synthetic peptides as immunogens. The peptides were synthesized specifically to represent those regions of the urokinase molecules which are exposed in the three-dimensional configuration of the molecule and are uniquely homologous to urokinase. Antibodies are directed against the lysine 158-isoleucine 159 peptide bond which is cleaved during activation from the single-chain (ScuPA) form to the bioactive double chain (54 KDa and 33 KDa) forms of urokinase and against the lysine 135 lysine 136 bond that is cleaved in the process of removing the alpha-chain from the 54 KDa form to produce the 33 KDa form of urokinase. These antibodies enable the direct measurement of the different molecular forms of urokinase from small samples of conditioned medium harvested from cell cultures.

  18. Antibody Response to Pneumocystis jirovecii

    OpenAIRE

    Daly, Kieran R.; Huang, Laurence; Morris, Alison; Koch, Judy; Crothers, Kristina; Levin, Linda; Eiser, Shary; Satwah, Supriya; Zucchi, Patrizia; Walzer, Peter D.

    2006-01-01

    We conducted a prospective pilot study of the serologic responses to overlapping recombinant fragments of the Pneumocystis jirovecii major surface glycoprotein (Msg) in HIV-infected patients with pneumonia due to P. jirovecii and other causes. Similar baseline geometric mean antibody levels to the fragments measured by an ELISA were found in both groups. Serum antibodies to MsgC in P. jirovecii patients rose to a peak level 3–4 weeks (p50 cells/μL and first episode of pneumocystosis were the ...

  19. Radioimmunotherapy with engineered antibody fragments

    International Nuclear Information System (INIS)

    Authors have developed and begun evaluating radiometal-chelated (213Bi) engineered antibody fragments as radioimmunotherapy agents that target the HER2/neu (c-erbB-2) antigen. The diabody format was found to have 40-fold greater affinity for HER2/neu and to be associated with significantly greater tumor localization than is achieved with scFv molecule. It is shown that short-lived isotopes like 213Bi would be most effective when used in conjunction with antibodies that targeted diffuse malignancies (leukemia or lymphoma) or when used for very rapid pretargeted radioimmunotherapy application in which the radioisotope is conjugated to a very small ligand

  20. Antibody sensed protein surface conformation

    Directory of Open Access Journals (Sweden)

    Scott R. Schricker

    2011-12-01

    Full Text Available An antibody-modified atomic force microscope (AFM tip was used to detect conformational changes of fibronectin deposited on a poly(methyl methacrylate/poly(acrylic acid block copolymer compared to PMMA and a random poly(methyl methacrylate/poly(acrylic acid copolymer with an identical chemical composition. Based on the antibody-protein adhesive force maps and phase imaging, it was found that the nanomorphology of the triblock copolymer induces the desired conformation of fibronectin. This finding demonstrates that block copolymer nanomorphology can be used to regulate protein conformation and potentially cellular response.

  1. Antibody profiling sensitivity through increased reporter antibody layering

    Energy Technology Data Exchange (ETDEWEB)

    Apel, William A; Thompson, Vicki S

    2013-02-26

    A method for analyzing a biological sample by antibody profiling for identifying forensic samples or for detecting the presence of an analyte. In an embodiment of the invention, the analyte is a drug, such as marijuana, Cocaine (crystalline tropane alkaloid), methamphetamine, methyltestosterone, or mesterolone. The method comprises attaching antigens to a surface of a solid support in a preselected pattern to form an array wherein locations of the antigens are known; contacting the array with the biological sample such that a portion of antibodies in the sample reacts with and binds to the antigens in the array to form immune complexes; washing away antibodies that do form immune complexes; and detecting the immune complexes, to form an antibody profile. Forensic samples are identified by comparing a sample from an unknown source with a sample from a known source. Further, an assay, such as a test for illegal drug use, can be coupled to a test for identity such that the results of the assay can be positively correlated to the subject's identity.

  2. Antibody profiling sensitivity through increased reporter antibody layering

    Energy Technology Data Exchange (ETDEWEB)

    Apel, William A.; Thompson, Vicki S.

    2013-02-26

    A method for analyzing a biological sample by antibody profiling for identifying forensic samples or for detecting the presence of an analyte. In an embodiment of the invention, the analyte is a drug, such as marijuana, Cocaine (crystalline tropane alkaloid), methamphetamine, methyltestosterone, or mesterolone. The method comprises attaching antigens to a surface of a solid support in a preselected pattern to form an array wherein locations of the antigens are known; contacting the array with the biological sample such that a portion of antibodies in the sample reacts with and binds to the antigens in the array to form immune complexes; washing away antibodies that do form immune complexes; and detecting the immune complexes, to form an antibody profile. Forensic samples are identified by comparing a sample from an unknown source with a sample from a known source. Further, an assay, such as a test for illegal drug use, can be coupled to a test for identity such that the results of the assay can be positively correlated to the subject's identity.

  3. Antibody profiling sensitivity through increased reporter antibody layering

    Energy Technology Data Exchange (ETDEWEB)

    Apel, William A.; Thompson, Vicki S

    2010-04-13

    A method for analyzing a biological sample by antibody profiling for identifying forensic samples or for detecting the presence of an analyte. In an embodiment of the invention, the analyte is a drug, such as marijuana, Cocaine (crystalline tropane alkaloid), methamphetamine, methyltestosterone, or mesterolone. The method comprises attaching antigens to a surface of a solid support in a preselected pattern to form an array wherein locations of the antigens are known; contacting the array with the biological sample such that a portion of antibodies in the sample reacts with and binds to the antigens in the array to form immune complexes; washing away antibodies that do form immune complexes; and detecting the immune complexes, to form an antibody profile. Forensic samples are identified by comparing a sample from an unknown source with a sample from a known source. Further, an assay, such as a test for illegal drug use, can be coupled to a test for identity such that the results of the assay can be positively correlated to the subject's identity.

  4. Antibody profiling sensitivity through increased reporter antibody layering

    International Nuclear Information System (INIS)

    A method for analyzing a biological sample by antibody profiling for identifying forensic samples or for detecting the presence of an analyte. In an embodiment of the invention, the analyte is a drug, such as marijuana, Cocaine (crystalline tropane alkaloid), methamphetamine, methyltestosterone, or mesterolone. The method comprises attaching antigens to a surface of a solid support in a preselected pattern to form an array wherein locations of the antigens are known; contacting the array with the biological sample such that a portion of antibodies in the sample reacts with and binds to the antigens in the array to form immune complexes; washing away antibodies that do form immune complexes; and detecting the immune complexes, to form an antibody profile. Forensic samples are identified by comparing a sample from an unknown source with a sample from a known source. Further, an assay, such as a test for illegal drug use, can be coupled to a test for identity such that the results of the assay can be positively correlated to the subject's identity.

  5. Structural Characterization of Peptide Antibodies

    DEFF Research Database (Denmark)

    Chailyan, Anna; Marcatili, Paolo

    2015-01-01

    better understand the underlying mechanisms of antibody-antigen interaction here we present a pipeline developed by us to structurally classify immunoglobulin antigen binding sites and to infer key sequence residues and other variables that have a prominent role in each structural class....

  6. Alternative affinity tools: more attractive than antibodies?

    NARCIS (Netherlands)

    Ruigrok, V.J.B.; Levisson, M.; Eppink, M.H.M.; Smidt, H.; Oost, van der J.

    2011-01-01

    Antibodies are the most successful affinity tools used today, in both fundamental and applied research (diagnostics, purification and therapeutics). Nonetheless, antibodies do have their limitations, including high production costs and low stability. Alternative affinity tools based on nucleic acids

  7. Detection of Campylobacter species using monoclonal antibodies

    Science.gov (United States)

    Young, Colin R.; Lee, Alice; Stanker, Larry H.

    1999-01-01

    A panel of species specific monoclonal antibodies were raised to Campylobacter coli, Campylobacter jejuni and Campylobacter lari. The isotypes, and cross-reactivity profiles of each monoclonal antibody against an extensive panel of micro- organisms, were determined.

  8. Progranulin antibodies in autoimmune diseases.

    Science.gov (United States)

    Thurner, Lorenz; Preuss, Klaus-Dieter; Fadle, Natalie; Regitz, Evi; Klemm, Philipp; Zaks, Marina; Kemele, Maria; Hasenfus, Andrea; Csernok, Elena; Gross, Wolfgang L; Pasquali, Jean-Louis; Martin, Thierry; Bohle, Rainer Maria; Pfreundschuh, Michael

    2013-05-01

    Systemic vasculitides constitute a heterogeneous group of diseases. Autoimmunity mediated by B lymphocytes and their humoral effector mechanisms play a major role in ANCA-associated vasculitis (AAV) as well as in non-ANCA associated primary systemic vasculitides and in the different types of autoimmune connective tissue disorders and rheumatoid arthritis. In order to detect autoantibodies in systemic vasculitides, we screened protein macroarrays of human cDNA expression libraries with sera from patients with ANCA-associated and ANCA-negative primary systemic vasculitides. This approach led to the identification of antibodies against progranulin, a 88 kDA secreted glycoprotein with strong anti-inflammatory activity in the course of disease of giant-cell arteritis/polymyalgia rheumatica (14/65), Takayasu's arteritis (4/13), classical panarteritis nodosa (4/10), Behcet's disease (2/6) and in the course of disease in granulomatosis with polyangiitis (31/75), Churg-Strauss syndrome (7/23) and in microscopic polyangiitis (7/19). In extended screenings the progranulin antibodies were also detected in other autoimmune diseases such as systemic lupus erythematosus (39/91) and rheumatoid arthritis (16/44). Progranulin antibodies were detected only in 1 of 97 healthy controls. Anti-progranulin positive patients with systemic vasculitides, systemic lupus erythematosus or rheumatoid arthritis had significant lower progranulin plasma levels, indicating a neutralizing effect. In light of the anti-inflammatory effects of progranulin, progranulin antibodies might exert pro-inflammatory effects thus contributing to the pathogenesis of the respective autoimmune diseases and might serve as a marker for disease activity. This hypothesis is supported by the fact that a positive progranulin antibody status was associated with active disease in granulomatosis with polyangiitis. PMID:23149338

  9. Virus Strain Discrimination Using Recombinant Antibodies

    OpenAIRE

    Boonham, N.; Barker, I.

    2002-01-01

    Most routine testing for plant viruses is currently carried out using monoclonal and polyclonal antibodies. Traditional methods of antibody production however can be time consuming and require the use of expensive cell culture facilities. Recombinant antibody technology however is starting to make an impact in this area, enabling the selection of antibody fragments in a few weeks compared with the many months associated with traditional methods and requires only basic microbiological faciliti...

  10. Immunoglobulin G4: an odd antibody

    NARCIS (Netherlands)

    R.C. Aalberse; S.O. Stapel; J. Schuurman; T. Rispens

    2009-01-01

    Despite its well-known association with IgE-mediated allergy, IgG4 antibodies still have several poorly understood characteristics. IgG4 is a very dynamic antibody: the antibody is involved in a continuous process of half-molecules (i.e. a heavy and attached light-chain) exchange. This process, also

  11. Nuclear-grade gadolinium oxide (Gd2O3) powder

    International Nuclear Information System (INIS)

    The specification covers the minimum chemical and physical characteristics of nuclear-grade gadolinium oxide powder intended for subsequent processing for use in nuclear fuel application, for example, as an addition to uranium dioxide. The specification includes a description of chemical and physical requirements, cleanliness, quality control, inspection, certification, rejection, packaging, and shipping

  12. Thermoluminescence and fluorescence studies on RbBr:Gd2+

    International Nuclear Information System (INIS)

    TL glow of γ-irradiated crystals shows a single peak at 380 K. On F-light bleaching a new peak attributable to Z1-centres appears around 355 K. The presence of OH-reduces the TL glow. The characteristic emission of the impurity is observed at 3.65 eV. The irradiated crystals show the presence of the 'O2--vacancy' complex. The Tl process is due to the thermal release of F-electrons. (author)

  13. Imaging cancer using PET - the effect of the bifunctional chelator on the biodistribution of a 64Cu-labeled antibody

    International Nuclear Information System (INIS)

    Introduction: Use of copper radioisotopes in antibody radiolabeling is challenged by reported loss of the radionuclide from the bifunctional chelator used to label the protein. The objective of this study was to investigate the relationship between the thermodynamic stability of the 64Cu-complexes of five commonly used bifunctional chelators (BFCs) and the biodistribution of an antibody labeled with 64Cu using these chelators in tumor-bearing mice. Methods: The chelators [S-2-(aminobenzyl)1,4,7-triazacyclononane-1,4,7-triacetic acid (p-NH2-Bn-NOTA): 6-[p-(bromoacetamido)benzyl]-1, 4, 8, 11-tetraazacyclotetradecane-N, N', N'', N'''-tetraacetic acid (BAT-6): S-2-(4-aminobenzyl)-1,4,7,10-tetraazacyclododocane tetraacetic acid (p-NH2-Bn-DOTA): 1,4,7,10-tetraazacyclododocane-N, N', N', N''-tetraacetic acid (DOTA): and 1-N-(4-aminobenzyl)-3,6,10,13,16,19-hexaazabicyclo[6.6.6]eicosane-1, 8-diamine (SarAr)] were conjugated to the anti-GD2 antibody ch14.18, and the modified antibody was labeled with 64Cu and injected into mice bearing subcutaneous human melanoma tumors (M21) (n = 3-5 for each study). Biodistribution data were obtained from positron emission tomography images acquired at 1, 24 and 48 hours post-injection, and at 48 hours post-injection a full ex vivo biodistribution study was carried out. Results: The biodistribution, including tumor targeting, was similar for all the radioimmunoconjugates. At 48 h post-injection, the only statistically significant differences in radionuclide uptake (p 64Cu]ch14.18-p-NH2-Bn-NOTA was 4.74 ± 0.77 per cent of the injected dose per gram of tissue (%ID/g), and for [64Cu]ch14.18-SarAr was 8.06 ± 0.77 %ID/g. Differences in tumor targeting correlated with variations in tumor size rather than which BFC was used. Conclusions: The results of this study indicate that differences in the thermodynamic stability of these chelator-Cu(II) complexes were not associated with significant differences in uptake of the tracer by the tumor

  14. Production, isolation, and characterization of rabbit anti-idiotypic antibodies directed against human antithyrotrophin receptor antibodies.

    OpenAIRE

    Baker, J. R.; Lukes, Y G; Burman, K. D.

    1984-01-01

    Previous studies have shown that anti-idiotypic antibodies can be developed in vivo through animal immunization with idiotype, and that these antibodies can be isolated from other anti-immunoglobulin antibodies by affinity purification. These techniques have relied on large amounts of idiotype, which were produced either by hyperimmunization or by monoclonal antibodies, to serve as the affinity adsorbent. In the present study, we produced anti-idiotypic antibodies to human anti-thyroid-stimul...

  15. Solid phase double-antibody radioimmunoassay procedure

    International Nuclear Information System (INIS)

    The present invention is concerned with the radioimmunoassay (RIA) procedure for assaying body fluid content of an antigenic substance which may either be an antigen itself or a hapten capable of being converted, such as by means of reaction with a protein, to an antigenic material. The present invention is concerned with a novel and improved modification of a double-antibody RIA technique in which there is a first antibody that is specific to the antigenic substance suspected to be present in a body fluid from which the assay is intended. The second antibody, however, is not specific to the antigenic substance or analyte, but is an antibody against the first antibody

  16. The role of antibodies in myasthenia gravis.

    Science.gov (United States)

    De Baets, M; Stassen, M H W

    2002-10-15

    Myasthenia gravis is an autoimmune disease associated with antibodies directed to the postsynaptic acetylcholine receptor. These antibodies reduce the number of receptors. Autoantibodies against AChR and other muscle antigens can be used for the diagnosis of myasthenia gravis and related disorders. The origin and the role of these antibodies in the disease are discussed. Experimental autoimmune myasthenia gravis, an experimental model closely mimicking the disease, has provided answers to many questions about the role of antibodies, complement macrophages and AChR anchor proteins. Genetically modified anti-AChR antibodies may also be used in the future to treat myasthenia. PMID:12220686

  17. Production of Monoclonal Antibody against Human Nestin.

    Science.gov (United States)

    Hadavi, Reza; Zarnani, Amir Hassan; Ahmadvand, Negah; Mahmoudi, Ahmad Reza; Bayat, Ali Ahmad; Mahmoudian, Jafar; Sadeghi, Mohammad-Reza; Soltanghoraee, Haleh; Akhondi, Mohammad Mehdi; Tarahomi, Majid; Jeddi-Tehrani, Mahmood; Rabbani, Hodjattallah

    2010-04-01

    We have employed a peptide-based antibody generation protocol for producing antibody against human nestin. Using a 12-mer synthetic peptide from repetitive region of human nestin protein devoid of any N- or O-glyco-sylation sequences, we generated a mouse monoclonal antibody capable of recognizing human, mouse, bovine, and rat nestin. A wide variety of nestin proteins ranging from 140-250 kDa was detected by this antibody. This antibody is highly specific and functional in applications such as ELISA, flow cytometry, immunocytochemistry, and Western blot assays. PMID:23407796

  18. Production of Monoclonal Antibody against Human Nestin

    OpenAIRE

    Hadavi, Reza; Zarnani, Amir Hassan; Ahmadvand, Negah; Mahmoudi, Ahmad Reza; Bayat, Ali Ahmad; Mahmoudian, Jafar; Sadeghi, Mohammad-Reza; Soltanghoraee, Haleh; Akhondi, Mohammad mehdi; Tarahomi, Majid; Jeddi-Tehrani, Mahmood; Rabbani, Hodjattallah

    2010-01-01

    We have employed a peptide-based antibody generation protocol for producing antibody against human nestin. Using a 12-mer synthetic peptide from repetitive region of human nestin protein devoid of any N- or O-glyco-sylation sequences, we generated a mouse monoclonal antibody capable of recognizing human, mouse, bovine, and rat nestin. A wide variety of nestin proteins ranging from 140–250 kDa was detected by this antibody. This antibody is highly specific and functional in applications such a...

  19. 9 CFR 113.452 - Erysipelothrix Rhusiopathiae Antibody.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Erysipelothrix Rhusiopathiae Antibody... REQUIREMENTS Antibody Products § 113.452 Erysipelothrix Rhusiopathiae Antibody. Erysipelothrix Rhusiopathiae Antibody is a specific antibody product containing antibodies directed against one or more somatic...

  20. Monoclonal Antibody Therapies against Anthrax

    OpenAIRE

    Zhaochun Chen; Mahtab Moayeri; Robert Purcell

    2011-01-01

    Anthrax is a highly lethal infectious disease caused by the spore-forming bacterium Bacillus anthracis. It not only causes natural infection in humans but also poses a great threat as an emerging bioterror agent. The lethality of anthrax is primarily attributed to the two major virulence factors: toxins and capsule. An extensive effort has been made to generate therapeutically useful monoclonal antibodies to each of the virulence components: protective antigen (PA), lethal factor (LF) and ede...

  1. Antibody Peptide Based Antifungal Immunotherapy

    OpenAIRE

    Magliani, Walter; Conti, Stefania; Giovati, Laura; Zanello, Pier Paolo; Sperindè, Martina; Ciociola, Tecla; Polonelli, Luciano

    2012-01-01

    Fungal infections still represent relevant human illnesses worldwide and some are accompanied by unacceptably high mortality rates. The limited current availability of effective and safe antifungal agents makes the development of new drugs and approaches of antifungal vaccination/immunotherapy every day more needed. Among them, small antibody(Ab)-derived peptides are arousing great expectations as new potential antifungal agents. In this topic, the search path from the study of the yeast kill...

  2. Epigenetics of the antibody response

    OpenAIRE

    Li, Guideng; Zan, Hong; Xu, Zhenming; Casali, Paolo

    2013-01-01

    Epigenetic marks, such as DNA methylation, histone posttranslational modifications and microRNAs, are induced in B cells by the same stimuli that drive the antibody response. They play major roles in regulating somatic hypermutation (SHM), class switch DNA recombination (CSR) and differentiation to plasma cells or long-lived memory B cells. Histone modifications target the CSR and, possibly, SHM machinery to the immunoglobulin locus; they together with DNA methylation and microRNAs modulate t...

  3. Pharmacological selection of antibodies for immunoscintigraphy

    International Nuclear Information System (INIS)

    The recent development of hybridoma technology has resulted in the production of monoclonal antibodies that recognize a variety of tumor antigens. Many antibodies have been developed and some of them are used with different success in clinical practice. A list of criteria is proposed for the selection of antibodies suitable for imaging studies illustrated with the example of two monoclonal antibodies anti-CEA and 19.9 used in colorectal carcinoma imaging. Monoclonal antibodies obtained today are not truly tumor-specific, they are tumor-associated; this suggests that some cross-reactions with normal tissues exist. For immunoscintigraphical use it is important to select antibodies which procedure high tumor cell staining with limited reactivity against normal tissues. Antibodies can be separated into F(ab')2 and Fab fragments which diffuse more easily into the tumor with a rapid clearance from the circulation giving higher tumor to normal tissues ratio at an early time. Antibodies with both high affinity and avidity towards tumor cell receptors produce better imaging results. Antibodies can be labelled directly with iodine or technetium and with indium using chelating agents. In vivo kinetics of radiolabelled antibodies are very different considering the nuclide and the labelling method used. Pharmacokinetics on nude mice grated with human tumors are very useful for selecting the most appropriate nuclide antibody fragment and the most efficient labelling technique for a given application. (author)

  4. Application of Monoclonal Antibodies in Veterinary Parasitology

    Directory of Open Access Journals (Sweden)

    Gupta A.

    2011-08-01

    Full Text Available The discovery of hybridoma technology by Kohler and Milstein in 1975, heralded a new era in antibody research. Mouse hybridomas were the first reliable source of monoclonal antibodies. The generation of monoclonal antibodies from species other than rats and mice, has developed slowly over the last 30 years. The advent of antibody engineering and realization of the advantages of non murine antibodies has increased their relevance recently. However, in the area of veterinary parasitology, monoclonal antibodies are just beginning to fulfill the promises inherent in their great specificity for recognizing and selectively binding to antigens. This review describes the recent advances in the application of monoclonal antibodies for immunodiagnosis / prophylaxis and immunotherapy of parasitic diseases. [Vet. World 2011; 4(4.000: 183-188

  5. Development of antibody against sulfamethazine

    International Nuclear Information System (INIS)

    Sulfamethazine (SMT) is widely used to treat bacterial and protozoan infections in food animals. So its residue has been detected in various food products, and in Europe, the tolerance level for sulfonamides in meat and milk is 100 ng/g. To ensure that residues in animal food products do not exceed this limit, a simple, sensitive, and rapid method to determinate their residues in animal tissues is needed. In this paper the development of polyclonal or monoclonal antibodies against sulfamethazine (SMT) and a simplified method to identify residual sulfamethazine by radio immunoassay (RIA) is presented. Polyclonal antibodies (PcAbs) against sulfamethazine (SMT) were obtained by immunizing rabbits with SMT-conjugated bovine serum albumin (BSA). The association constants (Ka) of the PcAbs were higher than 108 and the cross-reactivities with Sulfadiazine(SD), Sulfaquinoxaline(SQX) which were structurally related compounds were lower than 0.05%(RIA). Simultaneous, six strains of hybridoma cell were prepared which can secrete monoclonal antibodies (McAbs) against SMT . The Ka of the McAbs against SMT were higher than 107 and the cross-reactivities with SD, SQX were lower than 0.1%(RIA). (authors)

  6. Monoclonal antibodies in targeted therapy

    Directory of Open Access Journals (Sweden)

    Beata Powroźnik

    2012-09-01

    Full Text Available Targeted therapy is a new therapeutic method consisting in the inhibition of specific molecular pathways. In modern therapy, the key role is played by monoclonal antibodies, included in the group of biological agents. The success of molecularly targeted therapy is to define the proper “molecular target”, selecting the right drug active against a specific “target” and selecting a group of patients who benefit from treatment. Introduction of targeted therapy resulted in improved results of the treatment of many serious and chronic diseases. In general, targeted molecular therapies have good toxicity profiles, but some patients are exquisitely sensitive to these drugs and can develop particular and severe toxicities. Patient selection and proper monitoring significantly decrease the risk of life-threatening adverse events. Data concerning late side effects are still unavailable because of the short follow-up of molecularly targeted therapy. Currently in the U.S. and Europe there are approximately 31 registered therapeutic monoclonal antibodies, while 160 are subjected to clinical trials. This paper presents an overview of therapeutic monoclonal antibodies currently used in therapy and the present state of knowledge about them. 

  7. Advances in monoclonal antibody application in myocarditis

    Institute of Scientific and Technical Information of China (English)

    Li-na HAN; Shuang HE; Yu-tang WANG; Li-ming YANG; Si-yu LIU; Ting ZHANG

    2013-01-01

    Monoclonal antibodies have become a part of daily preparation technologies in many laboratories.Attempts have been made to apply monoclonal antibodies to open a new train of thought for clinical treatments of autoimmune diseases,inflammatory diseases,cancer,and other immune-associated diseases.This paper is a prospective review to anticipate that monoclonal antibody application in the treatment of myocarditis,an inflammatory disease of the heart,could be a novel approach in the future.In order to better understand the current state of the art in monoclonal antibody techniques and advance applications in myocarditis,we,through a significant amount of literature research both domestic and abroad,developed a systematic elaboration of monoclonal antibodies,pathogenesis of myocarditis,and application of monoclonal antibodies in myocarditis.This paper presents review of the literature of some therapeutic aspects of monoclonal antibodies in myocarditis and dilated cardiomyopathy to demonstrate the advance of monoclonal antibody application in myocarditis and a strong anticipation that monoclonal antibody application may supply an effective therapeutic approach to relieve the severity of myocarditis in the future.Under conventional therapy,myocarditis is typically associated with congestive heart failure as a progressive outcome,indicating the need for alternative therapeutic strategies to improve long-term results.Reviewing some therapeutic aspects of monoclonal antibodies in myocarditis,we recently found that monoclonal antibodies with high purity and strong specificity can accurately act on target and achieve definite progress in the treatment of viral myocarditis in rat model and may meet the need above.However,several issues remain.The technology on howto make a higher homologous and weak immunogenic humanized or human source antibody and the treatment mechanism of monoclonal antibodies may provide solutions for these open issues.If we are to further stimulate

  8. Affitins as alternative to antibodies

    International Nuclear Information System (INIS)

    Full text of publication follows. We have developed the use of Sac7d archaeal polypeptide and its homologues as a non-antibody scaffold from which artificial affinity proteins (Affitins) can be derived with a number of favorable properties. Affitins show affinity (sub-nanomolar) and specificity that compare well with those of antibodies [Ref.1]. They are thermally (up to 90 C. degrees) and chemically stable (pH 0-12+, denaturants), well expressed in E. coli (up to 200 mg/L), lack disulfide bridge and have a size compatible with chemical synthesis (7 kDa). We have demonstrated their use as reagents for intra-cellular inhibition [Ref.1], affinity purification [Ref.2], immuno-localization [Ref.3], protein chip array [Ref.4] and biosensors [Ref.5]. We have also shown that Affitins are plastic enough to tolerate several mutagenesis schemes while their fold and their favorable properties are conserved [Ref.6]. Compared to Affitins, monoclonal antibodies are 20 times larger, less stable and more complex molecules. Furthermore, the remarkable stability properties of Affitins make them suited for demanding labeling protocols that are usually used for peptides. All together, these results show that Affitins should be well suited for biomedical applications where fine tuning of the affinity reagent properties is needed. References: [Ref.1] Mouratou, B. et al., (2007), Proc Natl Acad Sci U S A 104, 17983-17988; [Ref.2] Krehenbrink, M. et al. (2008), J Mol Biol 383, 1058-1068; [Ref.3] Buddelmeijer, N. et al. (2009), J Bacteriol 191, 161-168; [Ref.4] Cinier, M. et al. (2009), Bioconjug. Chem. 20, 2270-2277; [Ref.5] Miranda, F. F. et al. (2011), Biosens. Bioelectron. 26, 4184-4190; [Ref.6] Behar G.et al. (2013), Protein Eng Des Sel. 26(4):267-75. (authors)

  9. Production and characterization of peptide antibodies

    DEFF Research Database (Denmark)

    Trier, Nicole Hartwig; Hansen, Paul Robert; Houen, Gunnar

    2012-01-01

    Proteins are effective immunogens for generation of antibodies. However, occasionally the native protein is known but not available for antibody production. In such cases synthetic peptides derived from the native protein are good alternatives for antibody production. These peptide antibodies are...... powerful tools in experimental biology and are easily produced to any peptide of choice. A widely used approach for production of peptide antibodies is to immunize animals with a synthetic peptide coupled to a carrier protein. Very important is the selection of the synthetic peptide, where factors such as......, including solid-phase peptide-carrier conjugation and peptide-carrier conjugation in solution. Upon immunization, adjuvants such as Al(OH)(3) are added together with the immunogenic peptide-carrier conjugate, which usually leads to high-titred antisera. Following immunization and peptide antibody...

  10. Immunogenicity of an engineered internal image antibody.

    OpenAIRE

    Billetta, R; Hollingdale, M. R.; Zanetti, M

    1991-01-01

    We engineered an antibody expressing in the third complementarity-determining region of its heavy chain variable region a "foreign" epitope, the repetitive tetrapeptide Asn-Ala-Asn-Pro (NANP) of the circumsporozoite protein of Plasmodium falciparum parasite, one of the etiologic agents of malaria in humans. A monoclonal antibody to P. falciparum specific for the (NANP)n amino acid sequence bound to the engineered antibody, and a synthetic (NANP)3 peptide blocked this interaction. Immunization...

  11. A general approach to antibody thermostabilization

    OpenAIRE

    McConnell, Audrey D; Xue ZHANG; Macomber, John L.; Chau, Betty; Sheffer, Joseph C; Rahmanian, Sorena; Hare, Eric; Spasojevic, Vladimir; Horlick, Robert A.; King, David J; Bowers, Peter M.

    2014-01-01

    Antibody engineering to enhance thermostability may enable further application and ease of use of antibodies across a number of different areas. A modified human IgG framework has been developed through a combination of engineering approaches, which can be used to stabilize antibodies of diverse specificity. This is achieved through a combination of complementarity-determining region (CDR)-grafting onto the stable framework, mammalian cell display and in vitro somatic hypermutation (SHM). Thi...

  12. Antibody-Mediated Lung Transplant Rejection

    OpenAIRE

    Hachem, Ramsey

    2012-01-01

    Antibody-mediated rejection after lung transplantation remains enigmatic. However, emerging evidence over the past several years suggests that humoral immunity plays an important role in allograft rejection. Indeed, the development of donor-specific antibodies after transplantation has been identified as an independent risk factor for acute cellular rejection and bronchiolitis obliterans syndrome. Furthermore, cases of acute antibody-mediated rejection resulting in severe allograft dysfunctio...

  13. Imaging tumors with radiolabelled monoclonal antibodies

    International Nuclear Information System (INIS)

    Using a metallic radionuclide, either directly bound to a monoclonal antibody, or to a chelating agent (such as di-ethylenetriamine-pentaacetic acid (DTPA)) conjugated to the antibody, a tumor can be traced rapidly and with high specificity. The labelled antibody is injected into the host. In some cases, a localization of distant metastases is possible, giving an indication of tumor spreading. Detection occurs by photoscanning. (Auth.)

  14. Haptens, conjugates and antibodies for pyrimethanil fungicide

    OpenAIRE

    Mercader Badia, Josep Vicent; Abad Fuentes, Antonio; Abad Somovilla, Antonio; Agulló, Consuelo

    2012-01-01

    [EN] The invention relates to haptens, conjugates and antibodies for pyrimethanil fungicide. In addition, the invention relates to the use of pyrimethanil conjugates as assay antigens or immunogens in order to obtain antibodies of the aforementioned fungicide, and to the use of the labelled derivatives of pyrimethanil as assay antigens. The invention also relates to a pyrimethanil analysis method using the antibodies obtained, at times together with assay antigens which are conjugates or labe...

  15. Monoclonal antibodies as diagnostics; an appraisal

    Directory of Open Access Journals (Sweden)

    Siddiqui M

    2010-01-01

    Full Text Available Ever since the development of Hybridoma Technology in 1975 by Kohler and Milstein, our vision for antibodies as tools for research for prevention, detection and treatment of diseases, vaccine production, antigenic characterization of pathogens and in the study of genetic regulation of immune responses and disease susceptibility has been revolutionized. The monoclonal antibodies being directed against single epitopes are homogeneous, highly specific and can be produced in unlimited quantities. In animal disease diagnosis, they are very useful for identification and antigenic characterization of pathogens. Monoclonal antibodies have tremendous applications in the field of diagnostics, therapeutics and targeted drug delivery systems, not only for infectious diseases caused by bacteria, viruses and protozoa but also for cancer, metabolic and hormonal disorders. They are also used in the diagnosis of lymphoid and myeloid malignancies, tissue typing, enzyme linked immunosorbent assay, radio immunoassay, serotyping of microorganisms, immunological intervention with passive antibody, antiidiotype inhibition, or magic bullet therapy with cytotoxic agents coupled with anti mouse specific antibody. Recombinant deoxyribonucleic acid technology through genetic engineering has successfully led to the possibility of reconstruction of monoclonal antibodies viz. chimeric antibodies, humanized antibodies and complementarily determining region grafted antibodies and their enormous therapeutic use.

  16. Single-domain antibodies for biomedical applications.

    Science.gov (United States)

    Krah, Simon; Schröter, Christian; Zielonka, Stefan; Empting, Martin; Valldorf, Bernhard; Kolmar, Harald

    2016-02-01

    Single-domain antibodies are the smallest antigen-binding units of antibodies, consisting either only of one variable domain or one engineered constant domain that solely facilitates target binding. This class of antibody derivatives comprises naturally occurring variable domains derived from camelids and sharks as well as engineered human variable or constant antibody domains of the heavy or light chain. Because of their high affinity and specificity as well as stability, small size and benefit of multiple re-formatting opportunities, those molecules emerged as promising candidates for biomedical applications and some of these entities have already proven to be successful in clinical development. PMID:26551147

  17. Mouse monoclonal antibodies against estrogen receptor.

    Science.gov (United States)

    De Rosa, Caterina; Rossi, Valentina; Abbondanza, Ciro

    2014-01-01

    The production of monoclonal antibodies, by cloning hybridoma derived from the fusion of myeloma cells and spleen lymphocytes, has allowed to obtain great advances in many fields of biological knowledge. The use of specific antibodies to the estrogen receptor, in fact, has been an invaluable method to bring out its mechanisms of action and its effects, both genomic and extra-genomic. Here we describe, step by step, the production of monoclonal antibodies, starting from protocol for antigen preparation to the selection of antibody-secreting hybridoma. PMID:25182770

  18. Heparin-Induced Thrombocytopenia Antibody Test

    Science.gov (United States)

    ... Thrombocytopenia Platelet Factor 4 Antibody Related tests: Complete Blood Count , Platelet Count , Serotonin Release Assay, Heparin-induced Platelet Aggregation All content on Lab Tests Online has been ...

  19. Monoclonal Antibodies for Lipid Management.

    Science.gov (United States)

    Feinstein, Matthew J; Lloyd-Jones, Donald M

    2016-07-01

    In recent years, biochemical and genetic studies have identified proprotein convertase subtilisin/kexin type 9 (PCSK9) as a major mediator of low-density lipoprotein cholesterol (LDL-c) levels and thereby a potential novel target for reducing risk of coronary heart disease (CHD). These observations led to the development of PCSK9 inhibitors, which lower LDL-c levels more than any other non-invasive lipid-lowering therapy presently available. The PCSK9 inhibitors furthest along in clinical trials are subcutaneously injected monoclonal antibodies. These PCSK9 inhibitors have demonstrated LDL-c-lowering efficacy with acceptable safety in phase III clinical trials and may offer a useful therapy in addition to maximally tolerated HMG-CoA reductase inhibitors (statins) in certain patient groups. Longer-term data are required to ensure sustained efficacy and safety of this new class of medications. This review provides an overview of the biology, genetics, development, and clinical trials of monoclonal antibodies designed to inhibit PCSK9. PMID:27221501

  20. Antiphospholipid Antibodies and Systemic Scleroderma

    Directory of Open Access Journals (Sweden)

    Awa Oumar Touré

    2013-03-01

    Full Text Available Objective: Antiphospholipid antibodies (APLs could be associated with an increased risk of vascular pathologies in systemic scleroderma. The aim of our study was to search for APLs in patients affected by systemic scleroderma and to evaluate their involvement in the clinical manifestations of this disease. Materials and Methods: We conducted a cross-sectional descriptive study, from January 2009 until August 2010, with patients received at the Department of Dermatology (Dakar, Senegal. Blood samples were taken at the hematology laboratory and were analyzed for the presence of APLs. Results: Forty patients were recruited. Various types of either isolated or associated APLs were found in 23 patients, i.e. 57.5% of the study population. The most frequently encountered antibody was IgG anti-β2 GPI (37.5% of the patients, followed by anticardiolipins (17.5% and lupus anticoagulants (5%. No statistically significant association of positive antiphospholipid-related tests to any of the scleroderma complications could be demonstrated. Conclusion: A high proportion of patients showing association of systemic scleroderma and APLs suggests the presence of a morbid correlation between these 2 pathologies. It would be useful to follow a cohort of patients affected by systemic scleroderma in order to monitor vascular complications following confirmation of the presence of antiphospholipid syndrome.

  1. An efficient method for isolating antibody fragments against small peptides by antibody phage display

    DEFF Research Database (Denmark)

    Duan, Zhi; Siegumfeldt, Henrik

    2010-01-01

    We generated monoclonal scFv (single chain variable fragment) antibodies from an antibody phage display library towards three small synthetic peptides derived from the sequence of s1-casein. Key difficulties for selection of scFv-phages against small peptides were addressed. Small peptides do not...... scFvs were sequenced and characterized, and specificity was characterized by ELISA. The methods developed in this study are universally applicable for antibody phage display to efficiently produce antibody fragments against small peptides....

  2. Stratification of Antibody-Positive Subjects by Antibody Level Reveals an Impact of Immunogenicity on Pharmacokinetics

    OpenAIRE

    Zhou, Lei; Hoofring, Sarah A.; Wu, Yu; Vu, Thuy; Ma, Peiming; Swanson, Steven J.; Chirmule, Narendra; Starcevic, Marta

    2012-01-01

    The availability of highly sensitive immunoassays enables the detection of antidrug antibody (ADA) responses of various concentrations and affinities. The analysis of the impact of antibody status on drug pharmacokinetics (PK) is confounded by the presence of low-affinity or low-concentration antibody responses within the dataset. In a phase 2 clinical trial, a large proportion of subjects (45%) developed ADA following weekly dosing with AMG 317, a fully human monoclonal antibody therapeutic....

  3. High level transient production of recombinant antibodies and antibody fusion proteins in HEK293 cells

    OpenAIRE

    Jäger, Volker; Büssow, Konrad; Wagner, Andreas; Weber, Susanne; Hust, Michael; Frenzel, André; Schirrmann, Thomas

    2013-01-01

    Background The demand of monospecific high affinity binding reagents, particularly monoclonal antibodies, has been steadily increasing over the last years. Enhanced throughput of antibody generation has been addressed by optimizing in vitro selection using phage display which moved the major bottleneck to the production and purification of recombinant antibodies in an end-user friendly format. Single chain (sc)Fv antibody fragments require additional tags for detection and are not as suitable...

  4. Antibodies to human fetal erythroid cells from a nonimmune phage antibody library

    OpenAIRE

    Huie, Michael A.; Cheung, Mei-Chi; Muench, Marcus O.; Becerril, Baltazar; Kan, Yuet W.; Marks, James D.

    2001-01-01

    The ability to isolate fetal nucleated red blood cells (NRBCs) from the maternal circulation makes possible prenatal genetic analysis without the need for diagnostic procedures that are invasive for the fetus. Such isolation requires antibodies specific to fetal NRBCs. To generate a panel of antibodies to antigens present on fetal NRBCs, a new type of nonimmune phage antibody library was generated in which multiple copies of antibody fragments are displayed on each pha...

  5. Passive antibody transfer in chickens to model maternal antibody after avian influenza vaccination

    Science.gov (United States)

    Birds transfer maternal antibodies (MAb) to their offspring through the egg yolk where the antibody is absorbed and enters the circulatory system. These maternal antibodies, depending on the pathogen, can provide early protection from some diseases, but it may also interfere with the vaccination re...

  6. 21 CFR 866.3290 - Gonococcal antibody test (GAT).

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Gonococcal antibody test (GAT). 866.3290 Section... antibody test (GAT). (a) Identification. A gonococcal antibody test (GAT) is an in vitro device that..., indirect fluorescent antibody, or radioimmunoassay, antibodies to Neisseria gonorrhoeae in sera...

  7. Photonic crystal fiber based antibody detection

    DEFF Research Database (Denmark)

    Duval, A; Lhoutellier, M; Jensen, J B; Hoiby, P E; Missier, V; Pedersen, L H; Hansen, Theis Peter; Bjarklev, Anders Overgaard; Bang, Ole

    An original approach for detecting labeled antibodies based on strong penetration photonic crystal fibers is introduced. The target antibody is immobilized inside the air-holes of a photonic crystal fiber and the detection is realized by the means of evanescent-wave fluorescence spectroscopy and...

  8. Receptor antibodies as novel therapeutics for diabetes

    DEFF Research Database (Denmark)

    Ussar, Siegfried; Vienberg, Sara Gry; Kahn, C Ronald

    2011-01-01

    Antibodies to receptors can block or mimic hormone action. Taking advantage of receptor isoforms, co-receptors, and other receptor modulating proteins, antibodies and other designer ligands can enhance tissue specificity and provide new approaches to the therapy of diabetes and other diseases....

  9. Monoclonal Antibody Therapy for Advanced Neuroblastoma

    Science.gov (United States)

    NCI is sponsoring two clinical trials of a monoclonal antibody called ch14.18, in combination with other drugs, to see if the antibody may be helpful for children or young adults (up to age 21) with relapsed or refractory neuroblastoma.

  10. Bioconjugation of antibodies to horseradish peroxidase (hrp)

    Science.gov (United States)

    The bioconjugation of an antibody to an enzymatic reporter such as horseradish peroxidase (HRP) affords an effective mechanism by which immunoassay detection of a target antigen can be achieved. The use of heterobifunctional cross—linkers to covalently link antibodies to HRP provides a simple and c...

  11. Thyrotropin receptor antibodies and its clinical application

    International Nuclear Information System (INIS)

    Thyrotropin receptor antibodies (TRAb) are not homogeneous, which are composed by four antibodies at least. TRAb plays very important roles in autoimmune thyroid diseases ad off-thyroid symptoms associated, and other thyroiditis in clinical diagnosis, assessment of curative effects, determination of the time to stop medicine, prognostication of recurrence and inspection of high risk population

  12. Monoclonal antibodies to Leptospira interrogans serovar pomona.

    OpenAIRE

    Ainsworth, A J; Lester, T L; Capley, G

    1985-01-01

    Three monoclonal antibodies produced against Leptospira interrogans serovar pomona have been studied for their diagnostic usefulness. All three monoclonals reacted strongly in the enzyme-linked immunosorbent assay and indirect fluorescent antibody test with serovar pomona and did not react with serovars grippotyphosa, canicola, icterohaemorrhagiae and hardjo.

  13. "Unconventional" Neutralizing Activity of Antibodies Against HIV

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Neutralizing antibodies are recognized to be one of the essential elements of the adaptive immune response that must be induced by an effective vaccine against HIV. However, only a limited number of antibodies have been identified to neutralize a broad range of primary isolates of HIV-1 and attempts to induce such antibodies by immunization were unsuccessful. The difficulties to generate such antibodies are mainly due to intrinsic properties of HIV-1 envelope spikes, such as high sequence diversity, heavy glycosylation, and inducible and transient nature of certain epitopes. In vitro neutralizing antibodies are identified using "conventional" neutralization assay which uses phytohemagglutinin (PHA)-stimulated human PBMCs as target cells. Thus, in essence the assay evaluates HIV-1 replication in CD4+ T cells. Recently, several laboratories including us demonstrated that some monoclonal antibodies and HIV-1-specific polyclonal IgG purified from patient sera, although they do not have neutralizing activity when tested by the "conventional" neutralization assay, do exhibit potent and broad neutralizing activity in "unconventional" ways. The neutralizing activity of these antibodies and IgG fractions is acquired through post-translational modifications, through opsonization of virus particles into macrophages and immature dendritic cells (iDCs), or through expression of antibodies on the surface of HIV-1-susceptible cells. This review will focus on recent findings of this area and point out their potential applications in the development of preventive strategies against HIV.

  14. Determination of Biotin: Antibody Molar Ratio

    International Nuclear Information System (INIS)

    The determination of the biotinylation yield (number of biotin molecules per molecule of antibody) is important to ensure that the MAb has maintained its immunoreactivity. If the biotinylation of the MAb is carried out with a molar ratio of biotin:antibody ~10:1, then the number of biotins per MAb usually ranges between 6 and 8

  15. Anti-influenza M2e antibody

    Energy Technology Data Exchange (ETDEWEB)

    Bradbury, Andrew M.

    2013-04-16

    Humanized recombinant and monoclonal antibodies specific for the ectodomain of the influenza virus M2 ion channel protein are disclosed. The antibodies of the invention have anti-viral activity and may be useful as anti-viral therapeutics and/or prophylactic/vaccine agents for inhibiting influenza virus replication and for treating individuals infected with influenza.

  16. Anti-influenza M2e antibody

    Energy Technology Data Exchange (ETDEWEB)

    Bradbury, Andrew M. (Santa Fe, NM)

    2011-12-20

    Humanized recombinant and monoclonal antibodies specific for the ectodomain of the influenza virus M2 ion channel protein are disclosed. The antibodies of the invention have anti-viral activity and may be useful as anti-viral therapeutics and/or prophylactic/vaccine agents for inhibiting influenza virus replication and for treating individuals infected with influenza.

  17. Nano antibody therapy for cancer

    International Nuclear Information System (INIS)

    Nanomedicine, an offshoot of nanotechnology, refers to highly specific medical intervention at the molecular scale for curing disease or repairing damaged tissues, such as bone, muscle, or nerve. Nanotechnology can have an early, paradigm-changing impact on how clinicians will detect cancer in its earliest stages. Exquisitely sensitive devices constructed of nanoscale components-such as nanocantilevers, nanowires and nanochannels-offer the potential for detecting even the rarest molecular signals associated with malignancy. One of the most pressing needs in clinical oncology is for imaging agents that can identify tumors that are far smaller than is possible with today's technology, at a scale of 100,000 cells rather than 1,000,000,000 cells. A new approach in nanotechnology for treating cancer incorporates nano iron particles and attaches them to an antibody that has targets only cancer cells and not healthy cells. The treatment works in two steps. This treatment is an ingenious way to make localized tumor ablation a systemic treatment. The advantages are incredible. There are absolutely no side effects from this treatment. It is not painful or even uncomfortable. The iron particles get flushed harmlessly from the body. It is not a drug and so the cancer cannot build up a resistance to the treatment. It is a systematic treatment; even cancer cells and tumors that are not known about get heated up and ablated. This treatment can even be used to enhance imaging of the cancer because once the cancer cells are coated with the iron particles, they are easy to identify. Everything depends on how reliably the antibodies target cancer cells and not healthy cells. When used in conjunction with other systemic treatments, such as vaccine treatments, we could be looking at a time when even advanced cancers can be brought under control. (author)

  18. Synthetic Antibodies for Reversible Cell Recognition

    Science.gov (United States)

    Zhou, Jing Zhou

    2011-12-01

    Antibody-mediated cell recognition plays a critical role in various biological and biomedical applications. However, strong antibody-cell interactions can lead to the difficulty of separating antibodies from the bound cells in a simple and non-destructive manner, which is often necessary to numerous applications such as cell sorting or separation. Thus, this thesis research is aimed to create an antibody-like nanomaterial with the function of reversible cell recognition It was hypothesized that nucleic acid aptamer and dendrimer could be used as fundamental structural components to develop an antibody-like nanomaterial. The aptamer functions as the binding site of an antibody; the dendrimer is used as a robust, defined nano-scaffold to support the aptamer and to carry small molecules (e.g., fluorophores). To test this hypothesis, a novel method was first developed to discover the essential nucleotides of full-length aptamers to mimic the binding sites of antibodies. The essential nucleotides were further conjugated with a dendrimer to synthesize a monovalent aptamer-dendrimer nanomaterial. The results clearly showed that the essential nucleotides could maintain high affinity and specificity after tethered on dendrimer surface. To further test the hypothesis that antibody-like nanomaterials can be rationally designed to acquire the capability of reversible cell recognition, an aptamer that was selected at 0 °C was used as a model to synthesize a "Y-shaped" nanomaterial by conjugating two aptamers to the same dendrimer. The results showed that the nanomaterial-cell interaction could be affected by the distance between two binding aptamers. In addition, the "Y-shaped" antibody-like nanomaterial could bind target cells more strongly than its monovalent control. Importantly, the strong cell-nanomaterial interaction could be rapidly reversed when the temperature was shifted from 0 °C to 37 °C. In summary, we developed a synthetic antibody that can not only mimic the

  19. Antibodies against chromosomal beta-lactamase

    DEFF Research Database (Denmark)

    Giwercman, B; Rasmussen, J W; Ciofu, Oana; Clemmentsen, I; Schumacher, H; Høiby, N

    1994-01-01

    A murine monoclonal anti-chromosomal beta-lactamase antibody was developed and an immunoblotting technique was used to study the presence of serum and sputum antibodies against Pseudomonas aeruginosa chromosomal group 1 beta-lactamase in patients with cystic fibrosis (CF). The serum antibody...... response was studied with serum samples collected in 1992 from 56 CF patients in a cross-sectional study and with serum samples from 18 CF patients in a longitudinal study. Anti-beta-lactamase immunoglobulin G antibodies were present in all of the serum samples from the patients with chronic...... bronchopulmonary P. aeruginosa infection (CF + P) but in none of the CF patients with no or intermittent P. aeruginosa infection. Anti-beta-lactamase antibodies were present in serum from CF + P patients after six antipseudomonal courses (median) and correlated with infection with a beta-lactam-resistant strain of...

  20. Antibody-Mediated Lung Transplant Rejection

    Science.gov (United States)

    Hachem, Ramsey

    2012-01-01

    Antibody-mediated rejection after lung transplantation remains enigmatic. However, emerging evidence over the past several years suggests that humoral immunity plays an important role in allograft rejection. Indeed, the development of donor-specific antibodies after transplantation has been identified as an independent risk factor for acute cellular rejection and bronchiolitis obliterans syndrome. Furthermore, cases of acute antibody-mediated rejection resulting in severe allograft dysfunction have been reported, and these demonstrate that antibodies can directly injure the allograft. However, the incidence and toll of antibody-mediated rejection are unknown because there is no widely accepted definition and some cases may be unrecognized. Clearly, humoral immunity has become an important area for research and clinical investigation. PMID:23002428

  1. Trends in Malignant Glioma Monoclonal Antibody Therapy

    Science.gov (United States)

    Chekhonin, Ivan; Gurina, Olga

    2015-01-01

    Although new passive and active immunotherapy methods are emerging, unconjugated monoclonal antibodies remain the only kind of biological preparations approved for high-grade glioma therapy in clinical practice. In this review, we combine clinical and experimental data discussion. As antiangiogenic therapy is the standard of care for recurrent glioblastoma multiforme (GBM), we analyze major clinical trials and possible therapeutic combinations of bevacizumab, the most common monoclonal antibody to vascular endothelial growth factor (VEGF). Another humanized antibody to gain recognition in GBM is epidermal growth factor (EGFR) antagonist nimotuzumab. Other antigens (VEGF receptor, platelet-derived growth factor receptor, hepatocyte growth factor and c-Met system) showed significance in gliomas and were used to create monoclonal antibodies applied in different malignant tumors. We assess the role of genetic markers (isocitrate dehydrogenase, O6-methylguanine-DNA methyltransnsferase) in GBM treatment outcome prediction. Besides antibodies studied in clinical trials, we focus on perspective targets and briefly list other means of passive immunotherapy.

  2. Antiphospholipid antibody: laboratory, pathogenesis and clinical manifestations

    Directory of Open Access Journals (Sweden)

    T. Ziglioli

    2011-06-01

    Full Text Available Antiphospholipid antibodies (aPL represent a heterogeneous group of antibodies that recognize various antigenic targets including beta2 glycoprotein I (β2GPI, prothrombin (PT, activated protein C, tissue plasminogen activator, plasmin and annexin A2. The most commonly used tests to detect aPL are: lupus anticoagulant (LAC, a functional coagulation assay, anticardiolipin antibody (aCL and anti-β2GPI antibody (anti-β2GPI, which are enzyme-linked immunoassay (ELISA. Clinically aPL are associated with thrombosis and/or with pregnancy morbidity. Apparently aPL alone are unable to induce thrombotic manifestations, but they increase the risk of vascular events that can occur in the presence of another thrombophilic condition; on the other hand obstetrical manifestations were shown to be associated not only to thrombosis but mainly to a direct antibody effect on the trophoblast.

  3. Isolation of Balamuthia mandrillaris-specific antibody fragments from a bacteriophage antibody display library.

    Science.gov (United States)

    Siddiqui, Ruqaiyyah; Kulsoom, Huma; Lalani, Salima; Khan, Naveed Ahmed

    2016-07-01

    Balamuthia mandrillaris is a protist pathogen that can cause encephalitis with a mortality rate of more than 95%. Early diagnosis followed by aggressive treatment is a pre-requisite for successful prognosis. Current methods for identifying this organism rely on culture and microscopy, antibody-based methods using animals, or involve the use of molecular tools that are expensive. Here, we describe the isolation of antibody fragments that can be used for the unequivocal identification of B. mandrillaris. B. mandrillaris-specific antibody fragments were isolated from a bacteriophage antibody display library. Individual clones were studied by enzyme-linked immunosorbent assay, and immunofluorescence. Four antibody clones showed specific binding to B. mandrillaris. The usefulness of phage antibody display technology as a diagnostic tool for isolating antibody fragments against B. mandrillaris antigens and studying their biological role(s) is discussed further. PMID:27055361

  4. Immobilization of antibodies and enzyme-labeled antibodies by radiation polymerization

    International Nuclear Information System (INIS)

    Immobilization of antibodies and enzyme-labeled antibodies by radiation polymerization at low temperatures was studied. The antibody activity of antibody was not affected by irradiation at an irradiation dose of below 8 MR and low temperatures. Immobilization of peroxidase-labeled anti-rabbit IgG goat IgG, anti-peroxidase, peroxidase, and anti-alpha-fetoprotein was carried out with hydrophilic and hydrophobic monomers. The activity of the immobilized enzyme-labeled antibody membranes varied with the thickness of the membranes and increased with decreasing membrane thickness. The activity of the immobilized antibody particles was varied by particle size. Immobilized anti-alpha-fetoprotein particles and membranes can be used for the assay of alpha-fetoprotein by the antigen-antibody reaction, such as a solid-phase sandwich method with high sensitivity

  5. Vector-Mediated In Vivo Antibody Expression.

    Science.gov (United States)

    Schnepp, Bruce C; Johnson, Philip R

    2014-08-01

    This article focuses on a novel vaccine strategy known as vector-mediated antibody gene transfer, with a particular focus on human immunodeficiency virus (HIV). This strategy provides a solution to the problem of current vaccines that fail to generate neutralizing antibodies to prevent HIV-1 infection and AIDS. Antibody gene transfer allows for predetermination of antibody affinity and specificity prior to "immunization" and avoids the need for an active humoral immune response against the HIV envelope protein. This approach uses recombinant adeno-associated viral (rAAV) vectors, which have been shown to transduce muscle with high efficiency and direct the long-term expression of a variety of transgenes, to deliver the gene encoding a broadly neutralizing antibody into the muscle. Following rAAV vector gene delivery, the broadly neutralizing antibodies are endogenously synthesized in myofibers and passively distributed to the circulatory system. This is an improvement over classical passive immunization strategies that administer antibody proteins to the host to provide protection from infection. Vector-mediated gene transfer studies in mice and monkeys with anti-HIV and simian immunodeficiency virus (SIV)-neutralizing antibodies demonstrated long-lasting neutralizing activity in serum with complete protection against intravenous challenge with virulent HIV and SIV. These results indicate that existing potent anti-HIV antibodies can be rapidly moved into the clinic. However, this methodology need not be confined to HIV. The general strategy of vector-mediated antibody gene transfer can be applied to other difficult vaccine targets such as hepatitis C virus, malaria, respiratory syncytial virus, and tuberculosis. PMID:26104192

  6. Radiohalogenated half-antibodies and maleimide intermediate therefor

    Science.gov (United States)

    Kassis, A.I.; Khawli, L.A.

    1991-02-19

    N-(m-radiohalophenyl) maleimide can be conjugated with a reduced antibody having a mercapto group to provide a radiolabeled half-antibody having immunological specific binding characteristics of whole antibody. No Drawings

  7. Generation and characterization of heavy chain antibodies derived from Camelids

    OpenAIRE

    Schmidthals, Katrin

    2013-01-01

    Antibodies and antibody fragments are essential tools in basic research, diagnostics and therapy. Conventional antibodies consist of two heavy and two light chains with both chains contributing to the antigen-binding site. In addition to these conventional antibodies, camelids (llamas, alpacas, dromedaries and camels) possess so-called heavy chain antibodies (hcAbs) that lack the light chains. The antigen binding site of these unusual antibodies is formed by one single domain only, the so cal...

  8. Antibody Engineering & Therapeutics, the annual meeting of The Antibody Society December 7-10, 2015, San Diego, CA, USA.

    Science.gov (United States)

    Pauthner, Matthias; Yeung, Jenny; Ullman, Chris; Bakker, Joost; Wurch, Thierry; Reichert, Janice M; Lund-Johansen, Fridtjof; Bradbury, Andrew R M; Carter, Paul J; Melis, Joost P M

    2016-01-01

    The 26th Antibody Engineering & Therapeutics meeting, the annual meeting of The Antibody Society united over 800 participants from all over the world in San Diego from 6-10 December 2015. The latest innovations and advances in antibody research and development were discussed, covering a myriad of antibody-related topics by more than 100 speakers, who were carefully selected by The Antibody Society. As a prelude, attendees could join the pre-conference training course focusing, among others, on the engineering and enhancement of antibodies and antibody-like scaffolds, bispecific antibody engineering and adaptation to generate chimeric antigen receptor constructs. The main event covered 4 d of scientific sessions that included antibody effector functions, reproducibility of research and diagnostic antibodies, new developments in antibody-drug conjugates (ADCs), preclinical and clinical ADC data, new technologies and applications for bispecific antibodies, antibody therapeutics for non-cancer and orphan indications, antibodies to harness the cellular immune system, building comprehensive IgVH-gene repertoires through discovering, confirming and cataloging new germline IgVH genes, and overcoming resistance to clinical immunotherapy. The Antibody Society's special session focused on "Antibodies to watch" in 2016. Another special session put the spotlight on the limitations of the new definitions for the assignment of antibody international nonproprietary names introduced by the World Health Organization. The convention concluded with workshops on computational antibody design and on the promise and challenges of using next-generation sequencing for antibody discovery and engineering from synthetic and in vivo libraries. PMID:26909869

  9. IBC’s 23rd Annual Antibody Engineering, 10th Annual Antibody Therapeutics International Conferences and the 2012 Annual Meeting of The Antibody Society

    OpenAIRE

    Klöhn, Peter-Christian; Wuellner, Ulrich; Zizlsperger, Nora; Zhou, Yu; Tavares, Daniel; Berger, Sven; Zettlitz, Kirstin A.; Proetzel, Gabriele; Yong, May; Begent, Richard H.J.; Reichert, Janice M

    2013-01-01

    The 23rd Annual Antibody Engineering, 10th Annual Antibody Therapeutics international conferences, and the 2012 Annual Meeting of The Antibody Society, organized by IBC Life Sciences with contributions from The Antibody Society and two Scientific Advisory Boards, were held December 3–6, 2012 in San Diego, CA. The meeting drew over 800 participants who attended sessions on a wide variety of topics relevant to antibody research and development. As a prelude to the main events, a pre-conference ...

  10. Antiphospholipid Antibodies in Lupus Nephritis.

    Science.gov (United States)

    Parodis, Ioannis; Arnaud, Laurent; Gerhardsson, Jakob; Zickert, Agneta; Sundelin, Birgitta; Malmström, Vivianne; Svenungsson, Elisabet; Gunnarsson, Iva

    2016-01-01

    Lupus nephritis (LN) is a major manifestation of systemic lupus erythematosus (SLE). It remains unclear whether antiphospholipid antibodies (aPL) alter the course of LN. We thus investigated the impact of aPL on short-term and long-term renal outcomes in patients with LN. We assessed levels of aPL cross-sectionally in SLE patients diagnosed with (n = 204) or without (n = 294) LN, and prospectively in 64 patients with active biopsy-proven LN (52 proliferative, 12 membranous), before and after induction treatment (short-term outcomes). Long-term renal outcome in the prospective LN cohort was determined by the estimated glomerular filtration rate (eGFR) and the Chronic Kidney Disease (CKD) stage, after a median follow-up of 11.3 years (range: 3.3-18.8). Cross-sectional analysis revealed no association between LN and IgG/IgM anticardiolipin or anti-β2-glycoprotein I antibodies, or lupus anticoagulant. Both aPL positivity and levels were similar in patients with active LN and non-renal SLE. Following induction treatment for LN, serum IgG/IgM aPL levels decreased in responders (p<0.005 for all), but not in non-responders. Both at active LN and post-treatment, patients with IgG, but not IgM, aPL had higher creatinine levels compared with patients without IgG aPL. Neither aPL positivity nor levels were associated with changes in eGFR from either baseline or post-treatment through long-term follow-up. Moreover, aPL positivity and levels both at baseline and post-treatment were similar in patients with a CKD stage ≥3 versus 1-2 at the last follow-up. In conclusion, neither aPL positivity nor levels were found to be associated with the occurrence of LN in SLE patients. However, IgG aPL positivity in LN patients was associated with a short-term impairment of the renal function while no effect on long-term renal outcome was observed. Furthermore, IgG and IgM aPL levels decreased following induction treatment only in responders, indicating that aPL levels are affected by

  11. Antiphospholipid Antibodies in Lupus Nephritis.

    Directory of Open Access Journals (Sweden)

    Ioannis Parodis

    Full Text Available Lupus nephritis (LN is a major manifestation of systemic lupus erythematosus (SLE. It remains unclear whether antiphospholipid antibodies (aPL alter the course of LN. We thus investigated the impact of aPL on short-term and long-term renal outcomes in patients with LN. We assessed levels of aPL cross-sectionally in SLE patients diagnosed with (n = 204 or without (n = 294 LN, and prospectively in 64 patients with active biopsy-proven LN (52 proliferative, 12 membranous, before and after induction treatment (short-term outcomes. Long-term renal outcome in the prospective LN cohort was determined by the estimated glomerular filtration rate (eGFR and the Chronic Kidney Disease (CKD stage, after a median follow-up of 11.3 years (range: 3.3-18.8. Cross-sectional analysis revealed no association between LN and IgG/IgM anticardiolipin or anti-β2-glycoprotein I antibodies, or lupus anticoagulant. Both aPL positivity and levels were similar in patients with active LN and non-renal SLE. Following induction treatment for LN, serum IgG/IgM aPL levels decreased in responders (p<0.005 for all, but not in non-responders. Both at active LN and post-treatment, patients with IgG, but not IgM, aPL had higher creatinine levels compared with patients without IgG aPL. Neither aPL positivity nor levels were associated with changes in eGFR from either baseline or post-treatment through long-term follow-up. Moreover, aPL positivity and levels both at baseline and post-treatment were similar in patients with a CKD stage ≥3 versus 1-2 at the last follow-up. In conclusion, neither aPL positivity nor levels were found to be associated with the occurrence of LN in SLE patients. However, IgG aPL positivity in LN patients was associated with a short-term impairment of the renal function while no effect on long-term renal outcome was observed. Furthermore, IgG and IgM aPL levels decreased following induction treatment only in responders, indicating that aPL levels are

  12. Antibodies Against Three Forms of Urokinase

    Science.gov (United States)

    Morrison, Dennis R.; Atassi, M. Zouhair

    2007-01-01

    Antibodies that bind to preselected regions of the urokinase molecule have been developed. These antibodies can be used to measure small quantities of each of three molecular forms of urokinase that could be contained in microsamples or conditioned media harvested from cultures of mammalian cells. Previously available antibodies and assay techniques do not yield both clear distinctions among, and measurements of, all three forms. Urokinase is a zymogen that is synthesized in a single-chain form, called ScuPA, which is composed of 411 amino acid residues (see figure). ScuPA has very little enzyme activity, but it can be activated in two ways: (1) by cleavage of the peptide bond lysine 158/isoleucine 159 and the loss of lysine 158 to obtain the high molecular-weight (HMW) form of the enzyme or (2) by cleavage of the bond lysine 135/lysine 136 to obtain the low-molecular-weight (LMW) form of the enzyme. The antibodies in question were produced in mice and rabbits by use of peptides as immunogens. The peptides were selected to obtain antibodies that bind to regions of ScuPA that include the lysine 158/isoleucine 159 and the lysine 135/lysine 136 bonds. The antibodies include monoclonal and polyclonal ones that yield indications as to whether either of these bonds is intact. The polyclonal antibodies include ones that preferentially bind to the HMW or LMW forms of the urokinase molecule. The monoclonal antibodies include ones that discriminate between the ScuPA and the HMW form. A combination of these molecular-specific antibodies will enable simultaneous assays of the ScuPA, HMW, and LMW forms in the same specimen of culture medium.

  13. Studies on Purification of Methamidophos Monoclonal Antibodies and Comoarative Immunoactivity of Purified Antibodies

    Institute of Scientific and Technical Information of China (English)

    SU-QING ZHAO; YUAN-MING SUN; CHUN-YAN ZHANG; XIAO-YU HUANG; HOU-RUI ZHANG; ZHEN-YU ZHU

    2003-01-01

    Objective To purify Methamidophos (Met) monoclonal antibodies with two methods andcompare immune activity of purified antibodies. Method Caprylic acid ammonium sulphateprecipition (CAASP) method and Sepharose protein-A (SPA) affinity chromatography method wereused to purify Met monoclonal antibodies, UV spectrum scanning was used to determine proteincontent and recovery of purified antibodies, sodium dodecylsulphate polyacrylamide gelelectrophoresis (SDS-PAGE) was used to analyze the purity of purified antibodies, and enzyme-linkedimmunosorbent assay (ELISA) was used to determine immune activity of purified antibodies.Results Antibody protein content and recovery rate with CAASP method were 7.62 mg/mL and8.05% respectively, antibody protein content and recovery rate with SPA method were 6.45 mg/mLand 5.52% respectively. Purity of antibodies purified by SPA method was higher than that by CAASPmethod. The half-maximal inhibition concentration (IC50) of antibodies purified by SPA to Met was181.26 μg/mL, and the linear working range and the limit of quantification (LOD) were 2.43-3896.01μg/mL and 1.03 μg/mL, respectively. The IC50 of antibodies purified by CAASP to Met was 352.82μg/mL, and the linear working range and LOD were 10.91-11412.29 ug/mL and 3.42 μg/mL,respectively. Conclusion Antibodies purified by SPA method are better than those by CAASPmethod, and Met monoclonal antibodies purified by SPA method can be used to prepare gold-labelledtesting paper for analyzing Met residue in vegetable and drink water.

  14. Uses of monoclonial antibody 8H9

    Energy Technology Data Exchange (ETDEWEB)

    Cheung, Nai-Kong V.

    2015-06-23

    This invention provides an antibody that binds the same antigen as that of monoclonal antibody 8H9, wherein the heavy chain CDR (Complementary Determining Region)1 comprises NYDIN, heavy chain CDR2 comprises WIFPGDGSTQY, heavy chain CDR3 comprises QTTATWFAY, and the light chain CDR1 comprises RASQSISDYLH, light chain CDR2 comprises YASQSIS, and light chain CDR3 comprises QNGHSFPLT. In another embodiment, there is provided a polypeptide that binds the same antigen as that of monoclonal antibody 8H9, wherein the polypeptide comprises NYDIN, WIFPGDGSTQY, QTTATWFAY, RASQSISDYLH, YASQSIS, and QNGHSFPLT.

  15. Clinical application of a new antimyosin antibody

    International Nuclear Information System (INIS)

    A mouse monoclonal antibody, 3-48 (Rougier Bio-Tech Ltd, Montreal) which recognizes the alpha and beta heavy chains of human atrial and ventricular myosin, and the beta heavy chain of human slow skeletal muscle, has recently been developed. In the rat isoproterenol-induced infarction model and the canine model of selective obstruction of a coronary artery, the antibody was shown to be specifically localized to the necrotic myocardium. A selected group of patients with known infarction was imaged with the 111indium labeled F(ab')2 protion of this antibody in a pre-clinical feasibility study, and the results therefrom are reported in this communication. (orig.)

  16. Antibody catalysis of peptide bond formation.

    OpenAIRE

    Jacobsen, J R; Schultz, P. G.

    1994-01-01

    An antibody generated against a neutral phosphonate diester transition-state (TS not equal to) analog catalyzes the formation of an amide bond between a phenylalanyl amino group and an acyl azide derived from L-alanine. The antibody is selective for L- vs. D-alanine and does not catalyze the hydrolysis of the acyl azide to an appreciable degree. A rate acceleration of 10,000-fold relative to the uncatalyzed reaction is observed. The antibody may achieve its catalytic efficiency both by acting...

  17. The antibody approach of labeling blood cells

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, S.C.

    1991-12-31

    Although the science of blood cell labeling using monoclonal antibodies directed against specific cellular antigens is still in its early stages, considerable progress has recently been accomplished in this area. The monoclonal antibody approach offers the promise of greater selectivity and enhanced convenience since specific cell types can be labeled in vivo, thus eliminating the need for complex and damaging cell separation procedures. This article focuses on these developments with primary emphasis on antibody labeling of platelets and leukocytes. The advantages and the shortcomings of the recently reported techniques are criticality assessed and evaluated.

  18. The antibody approach of labeling blood cells

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, S.C.

    1992-12-31

    Although the science of blood cell labeling using monoclonal antibodies directed against specific cellular antigens is still in its early stages, considerable progress has recently been accomplished in this area. The monoclonal antibody approach offers the promise of greater selectivity and enhanced convenience since specific cell types can be labeled in vivo, thus eliminating the need for complex and damaging cell separation procedures. This article focuses on these developments with primary emphasis on antibody labeling of platelets and leukocytes. The advantages and the shortcomings of the recently reported techniques are critically assessed and evaluated.

  19. The antibody approach of labeling blood cells

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, S.C.

    1991-01-01

    Although the science of blood cell labeling using monoclonal antibodies directed against specific cellular antigens is still in its early stages, considerable progress has recently been accomplished in this area. The monoclonal antibody approach offers the promise of greater selectivity and enhanced convenience since specific cell types can be labeled in vivo, thus eliminating the need for complex and damaging cell separation procedures. This article focuses on these developments with primary emphasis on antibody labeling of platelets and leukocytes. The advantages and the shortcomings of the recently reported techniques are criticality assessed and evaluated.

  20. The antibody approach of labeling blood cells

    International Nuclear Information System (INIS)

    Although the science of blood cell labeling using monoclonal antibodies directed against specific cellular antigens is still in its early stages, considerable progress has recently been accomplished in this area. The monoclonal antibody approach offers the promise of greater selectivity and enhanced convenience since specific cell types can be labeled in vivo, thus eliminating the need for complex and damaging cell separation procedures. This article focuses on these developments with primary emphasis on antibody labeling of platelets and leukocytes. The advantages and the shortcomings of the recently reported techniques are critically assessed and evaluated

  1. Reshaping Human Antibodies: Grafting an Antilysozyme Activity

    Science.gov (United States)

    Verhoeyen, Martine; Milstein, Cesar; Winter, Greg

    1988-03-01

    The production of therapeutic human monoclonal antibodies by hybridoma technology has proved difficult, and this has prompted the ``humanizing'' of mouse monoclonal antibodies by recombinant DNA techniques. It was shown previously that the binding site for a small hapten could be grafted from the heavy-chain variable domain of a mouse antibody to that of a human myeloma protein by transplanting the hypervariable loops. It is now shown that a large binding site for a protein antigen (lysozyme) can also be transplanted from mouse to human heavy chain. The success of such constructions may be facilitated by an induced-fit mechanism.

  2. The antibody approach of labeling blood cells

    International Nuclear Information System (INIS)

    Although the science of blood cell labeling using monoclonal antibodies directed against specific cellular antigens is still in its early stages, considerable progress has recently been accomplished in this area. The monoclonal antibody approach offers the promise of greater selectivity and enhanced convenience since specific cell types can be labeled in vivo, thus eliminating the need for complex and damaging cell separation procedures. This article focuses on these developments with primary emphasis on antibody labeling of platelets and leukocytes. The advantages and the shortcomings of the recently reported techniques are criticality assessed and evaluated

  3. Class specific antibody response to gonococcal infection.

    OpenAIRE

    Miettinen, A; Hakkarainen, K; Grönroos, P; Heinonen, P.; Teisala, K; Aine, R; Sillantaka, I; Saarenmaa, K; Lehtinen, M; Punnonen, R

    1989-01-01

    An enzyme immunoassay was used to determine IgM, IgG, and IgA antibodies to gonococcal pili in 68 patients with uncomplicated gonorrhoea, 35 women with pelvic inflammatory disease, and in 115 normal controls. A clear difference in response rate in all three antibody classes between patients with gonorrhoea and healthy controls was evident. Among women with gonorrhoea, the magnitude of antibody response was higher than among men with gonorrhoea, especially in the IgM class. No major difference...

  4. Imaging cancer using PET - the effect of the bifunctional chelator on the biodistribution of a {sup 64}Cu-labeled antibody

    Energy Technology Data Exchange (ETDEWEB)

    Dearling, Jason L.J., E-mail: jason.dearling@childrens.harvard.ed [Division of Nuclear Medicine and Department of Radiology, Children' s Hospital Boston, 300 Longwood Avenue, Boston, MA 02115 (United States); Harvard Medical School, Boston, MA 02115 (United States); Voss, Stephan D. [Division of Nuclear Medicine and Department of Radiology, Children' s Hospital Boston, 300 Longwood Avenue, Boston, MA 02115 (United States); Harvard Medical School, Boston, MA 02115 (United States); Dunning, Patricia; Snay, Erin [Division of Nuclear Medicine and Department of Radiology, Children' s Hospital Boston, 300 Longwood Avenue, Boston, MA 02115 (United States); Fahey, Frederic [Division of Nuclear Medicine and Department of Radiology, Children' s Hospital Boston, 300 Longwood Avenue, Boston, MA 02115 (United States); Harvard Medical School, Boston, MA 02115 (United States); Smith, Suzanne V. [Australian National Science and Technology Organisation (ANSTO), New Illawarra Road, PMB1, Menai, New South Wales 2234 (Australia); Huston, James S. [EMD Serono Research Center, 45A Middlesex Turnpike, Billerica, MA 01821-3936 (United States); Boston Biomedical Research Institute, Watertown, MA 02472-2899 (United States); Meares, Claude F. [Department of Chemistry, University of California, One Shields Avenue, Davis, CA 95616-5295 (United States); Treves, S. Ted; Packard, Alan B. [Division of Nuclear Medicine and Department of Radiology, Children' s Hospital Boston, 300 Longwood Avenue, Boston, MA 02115 (United States); Harvard Medical School, Boston, MA 02115 (United States)

    2011-01-15

    Introduction: Use of copper radioisotopes in antibody radiolabeling is challenged by reported loss of the radionuclide from the bifunctional chelator used to label the protein. The objective of this study was to investigate the relationship between the thermodynamic stability of the {sup 64}Cu-complexes of five commonly used bifunctional chelators (BFCs) and the biodistribution of an antibody labeled with {sup 64}Cu using these chelators in tumor-bearing mice. Methods: The chelators [S-2-(aminobenzyl)1,4,7-triazacyclononane-1,4,7-triacetic acid (p-NH{sub 2}-Bn-NOTA): 6-[p-(bromoacetamido)benzyl]-1, 4, 8, 11-tetraazacyclotetradecane-N, N', N'', N'''-tetraacetic acid (BAT-6): S-2-(4-aminobenzyl)-1,4,7,10-tetraazacyclododocane tetraacetic acid (p-NH{sub 2}-Bn-DOTA): 1,4,7,10-tetraazacyclododocane-N, N', N', N''-tetraacetic acid (DOTA): and 1-N-(4-aminobenzyl)-3,6,10,13,16,19-hexaazabicyclo[6.6.6]eicosane-1, 8-diamine (SarAr)] were conjugated to the anti-GD2 antibody ch14.18, and the modified antibody was labeled with {sup 64}Cu and injected into mice bearing subcutaneous human melanoma tumors (M21) (n = 3-5 for each study). Biodistribution data were obtained from positron emission tomography images acquired at 1, 24 and 48 hours post-injection, and at 48 hours post-injection a full ex vivo biodistribution study was carried out. Results: The biodistribution, including tumor targeting, was similar for all the radioimmunoconjugates. At 48 h post-injection, the only statistically significant differences in radionuclide uptake (p < 0.05) were between blood, liver, spleen and kidney. For example, liver uptake of [{sup 64}Cu]ch14.18-p-NH{sub 2}-Bn-NOTA was 4.74 {+-} 0.77 per cent of the injected dose per gram of tissue (%ID/g), and for [{sup 64}Cu]ch14.18-SarAr was 8.06 {+-} 0.77 %ID/g. Differences in tumor targeting correlated with variations in tumor size rather than which BFC was used. Conclusions: The results of this

  5. [Anti-basal ganglia antibody].

    Science.gov (United States)

    Hayashi, Masaharu

    2013-04-01

    Sydenham's chorea (SC) is a major manifestation of rheumatic fever, and the production of anti-basal ganglia antibodies (ABGA) has been proposed in SC. The pathogenesis is hypothesized as autoimmune targeting of the basal ganglia via molecular mimicry, triggered by streptococcal infection. The spectrum of diseases in which ABGA may be involved has been broadened to include other extrapyramidal movement disorders, such as tics, dystonia, and Parkinsonism, as well as other psychiatric disorders. The autoimmune hypothesis in the presence and absence of ABGA has been suggested in Tourette's syndrome (TS), early onset obsessive-compulsive disorders (OCD), and pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS). Recently, the relationship between ABGA and dopamine neurons in the basal ganglia has been examined, and autoantibodies against dopamine receptors were detected in the sera from patients with basal ganglia encephalitis. In Japan, the occurrence of subacute encephalitis, where patients suffer from episodes of altered behavior and involuntary movements, has increased. Immune-modulating treatments are effective, indicating the involvement of an autoimmune mechanism. We aimed to detect the anti-neuronal autoantibodies in such encephalitis, using immunohistochemical assessment of patient sera. The sera from patients showing involuntary movements had immunoreactivity for basal ganglia neurons. Further epitopes for ABGA will be investigated in basal ganglia disorders other than SC, TS, OCD, and PANDAS. PMID:23568985

  6. Radioimmunological proof of thyroglobulin antibodies in humans by the use of a double antibody method

    International Nuclear Information System (INIS)

    Thyroid antibodies, especially thyroglobulin antibodies, allow themselves to be proven with the double antibody method, in competitive radio binding assays and with the solid phase technique. These methods offer advantages relative to sensitivity and quantifiability. In this work a sensitive radioimmunoassay as a double antibody method was worked out whereby a 125 I-thyroglobulin/thyroglobulin antibody immune complex was precipitated out using anti-human immunoglobulin. The measured results from the radioimmunoassay show a good correlation with the results of the immune histological findings. A high to very high Tg antibody level occurs with autoimmune thyroiditis (80%), primary hypothyroidism (74%) and hyperthyroidism (70%). The control values with healthy people came to less than 5% specific binding. In correlation with the results of other authors this method is advantageous relative to test start and evaluation procedures. (orig.)

  7. Antibodies against the calcium-binding protein

    International Nuclear Information System (INIS)

    Plant microsomes contain a protein clearly related to a calcium-binding protein, calsequestrin, originally found in the sarcoplasmic reticulum of muscle cells, responsible for the rapid release and uptake of Ca2+ within the cells. The location and role of calsequestrin in plant cells is unknown. To generate monoclonal antibodies specific to plant calsequestrin, mice were immunized with a microsomal fraction from cultured cells of Streptanthus tortuosus (Brassicaceae). Two clones cross-reacted with one protein band with a molecular weight equal to that of calsequestrin (57 kilodaltons) by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting. This band is able to bind 45Ca2+ and can be recognized by a polyclonal antibody against the canine cardiac muscle calsequestrin. Rabbit skeletal muscle calsequestrin cross-reacted with the plant monoclonal antibodies. The plant monoclonal antibodies generated here are specific to calsequestrin protein

  8. Polynucleotides encoding anti-sulfotyrosine antibodies

    Science.gov (United States)

    Bertozzi, Carolyn R.; Kehoe, John; Bradbury, Andrew M.

    2011-01-11

    The invention provides anti-sulfotyrosine specific antibodies capable of detecting and isolating polypeptides that are tyrosine-sulfated. The sulfotyrosine antibodies and antibody fragments of the invention may be used to discriminate between the non-sulfated and sulfated forms of such proteins, using any number of immunological assays, such ELISAs, immunoblots, Western Blots, immunoprecipitations, and the like. Using a phage-display system, single chain antibodies (scFvs) were generated and screened against tyrosine-sulfated synthetic peptide antigens, resulting in the isolation of scFvs that specifically recognize sulfotyrosine-containing peptides and/or demonstrate sulfotyrosine-specific binding in tyrosine sulfated proteins. The VH and VL genes from one such sulfotyrosine-specific scFv were employed to generate a full length, sulfotyrosine-specific immunoglobulin.

  9. Patient-Derived Antibody Targets Tumor Cells

    Science.gov (United States)

    An NCI Cancer Currents blog on an antibody derived from patients that killed tumor cells in cell lines of several cancer types and slowed tumor growth in mouse models of brain and lung cancer without evidence of side effects.

  10. Chemical biology: How to minimalize antibodies

    Science.gov (United States)

    Rader, Christoph

    2015-02-01

    The success of antibodies as pharmaceuticals has triggered interest in crafting much smaller mimics. A crucial step forward has been taken with the chemical synthesis of small molecules that recruit immune cells to attack cancer cells.

  11. Immunoglobulin Classification Using the Colored Antibody Graph.

    Science.gov (United States)

    Bonissone, Stefano R; Pevzner, Pavel A

    2016-06-01

    The somatic recombination of V, D, and J gene segments in B-cells introduces a great deal of diversity, and divergence from reference segments. Many recent studies of antibodies focus on the population of antibody transcripts that show which V, D, and J gene segments have been favored for a particular antigen, a repertoire. To properly describe the antibody repertoire, each antibody must be labeled by its constituting V, D, and J gene segment, a task made difficult by somatic recombination and hypermutation events. While previous approaches to repertoire analysis were based on sequential alignments, we describe a new de Bruijn graph-based algorithm to perform VDJ labeling and benchmark its performance. PMID:27149636

  12. Deep sequencing and human antibody repertoire analysis.

    Science.gov (United States)

    Boyd, Scott D; Crowe, James E

    2016-06-01

    In the past decade, high-throughput DNA sequencing (HTS) methods and improved approaches for isolating antigen-specific B cells and their antibody genes have been applied in many areas of human immunology. This work has greatly increased our understanding of human antibody repertoires and the specific clones responsible for protective immunity or immune-mediated pathogenesis. Although the principles underlying selection of individual B cell clones in the intact immune system are still under investigation, the combination of more powerful genetic tracking of antibody lineage development and functional testing of the encoded proteins promises to transform therapeutic antibody discovery and optimization. Here, we highlight recent advances in this fast-moving field. PMID:27065089

  13. Monoclonal antibodies for radioimmunoimaging: Current perspectives

    International Nuclear Information System (INIS)

    The ability to image tumor using radiolabeled monoclonal antibody products has been widely demonstrated. The questions of safety and efficacy remain open and require further experience, but in some clinical situations, radioimmunoimaging has provided clinically useful information. This paper deals with a set of current problems in imaging with radiolabeled monoclonal antibodies and current perspectives on the possible solutions to these problems. The major areas discussed here are the following: (a) The selection process. How might we choose the ''best'' antibody for imaging from among the multitude now available and what form (i.e., which fragments) may be useful? (b) The imaging procedure: What are the basic optimal imaging parameters and how does the data produced by this modality interface with information obtained by more standard methods of imaging? (c) Quantitative techniques: How can noninvasive quantitative techniques provide information useful to the antibody selection process and to the diagnostic and therapeutic applications

  14. Antibody deficiency in Rubinstein-Taybi syndrome.

    Science.gov (United States)

    Herriot, R; Miedzybrodzka, Z

    2016-03-01

    The developmental disorder Rubinstein-Taybi syndrome (RTS) is frequently complicated by recurrent respiratory infections. In many cases this is likely to be the result of microaspiration or gastro-oesophageal reflux but, in a proportion, underlying antibody deficiency is a potentially modifiable susceptibility factor for infection. Relatively subtle, specific defects of pneumococcal antibody production have previously been described in the context of RTS. Here, we report a rare association between the syndrome and an overt, major primary antibody deficiency disorder (common variable immune deficiency) which was successfully managed with immunoglobulin replacement therapy. Early recognition and investigation for antibody deficiency associated with RTS allied to effective and optimized treatment are essential to minimize morbidity and mortality and improve quality and duration of life. PMID:26307339

  15. New haptens and antibodies for ractopamine.

    Science.gov (United States)

    Wang, Zhanhui; Liu, Meixuan; Shi, Weimin; Li, Chenglong; Zhang, Suxia; Shen, Jianzhong

    2015-09-15

    In this work, three unreported immunizing haptens of ractopamine (RAC) were synthesized and used to produce highly sensitive and specific polyclonal antibody. The spacer arms of haptens for coupling to protein carrier were located on different position of RAC with different length. High affinity polyclonal antibodies were obtained and characterized in terms of titer and sensitivity by using enzyme-linked immunosorbent assay (ELISA). The best antibody employed in a heterologous competitive ELISA exhibited an IC50 value as low as 0.12ngmL(-1) and could not recognize other 10 β-agonists including clenbuterol and salbutamol. The heterologous competitive ELISA was preliminary applied to swine urine and the results showed the new antibody was sufficiently sensitive and specific, and potentially used for the detection of RAC at trace level in real samples. PMID:25863617

  16. Localization of tumors by radiolabelled antibodies

    International Nuclear Information System (INIS)

    A method of utilizing radiolabelled antibodies to carcinoembryonic antigens for determining the site of tumors which produce or are associated with carcinoembryonic antigen is disclosed. 3 claims, no drawings

  17. Lack of in Vivo Antibody Dependent Cellular Cytotoxicity with Antibody Containing Gold Nanoparticles

    OpenAIRE

    Ahmed, Marya; Pan, Dorothy W.; Davis, Mark E.

    2015-01-01

    Antibody-dependent cellular cytotoxicity (ADCC) is a cytolytic mechanism that can elicit in vivo antitumor effects and can play a significant role in the efficacy of antibody treatments for cancer. Here, we prepared cetuximab, panitumumab, and rituximab containing gold nanoparticles and investigated their ability to produce an ADCC effect in vivo. Cetuximab treatment of EGFR-expressing H1975 tumor xenografts showed significant tumor regression due to the ADCC activity of the antibody in vivo,...

  18. Antibody-Specific Model of Amino Acid Substitution for Immunological Inferences from Alignments of Antibody Sequences

    OpenAIRE

    Mirsky, Alexander; Kazandjian, Linda; Anisimova, Maria

    2014-01-01

    Antibodies are glycoproteins produced by the immune system as a dynamically adaptive line of defense against invading pathogens. Very elegant and specific mutational mechanisms allow B lymphocytes to produce a large and diversified repertoire of antibodies, which is modified and enhanced throughout all adulthood. One of these mechanisms is somatic hypermutation, which stochastically mutates nucleotides in the antibody genes, forming new sequences with different properties and, eventually, hig...

  19. Quantitative Assessment of Antibody Internalization with Novel Monoclonal Antibodies against Alexa Fluorophores

    OpenAIRE

    Liao-Chan, Sindy; Daine-Matsuoka, Barbara; Heald, Nathan; Wong, Tiffany; Lin, Tracey; Cai, Allen G.; Lai, Michelle; D’Alessio, Joseph A.; Theunissen, Jan-Willem

    2015-01-01

    Antibodies against cell surface antigens may be internalized through their specific interactions with these proteins and in some cases may induce or perturb antigen internalization. The anti-cancer efficacy of antibody-drug conjugates is thought to rely on their uptake by cancer cells expressing the surface antigen. Numerous techniques, including microscopy and flow cytometry, have been used to identify antibodies with desired cellular uptake rates. To enable quantitative measurements of inte...

  20. Development of Monoclonal Antibodies Suitable for Rabies Virus Antibody and Antigen Detection

    OpenAIRE

    Chander, Vishal; Singh, R.P.; Verma, P. C.

    2012-01-01

    The control of an infectious viral disease as rabies is made easier by rapid and accurate diagnosis. Successful rabies prophylaxis is dependent upon the active immunization with vaccine along with passive administration of rabies virus neutralizing antibodies which together clear the virus before widespread infection of central nervous system occurs. The present study aimed at the development of monoclonal antibodies (MAbs) suitable for rabies virus antibody and antigen detection. For the pro...

  1. A monoclonal thyroid-stimulating antibody

    OpenAIRE

    Ando, Takao; Latif, Rauf; Pritsker, Alla; Moran, Thomas; Nagayama, Yuji; Davies, Terry F.

    2002-01-01

    The thyrotropin receptor, also known as the thyroid-stimulating hormone receptor (TSHR), is the primary antigen of Graves disease. Stimulating TSHR antibodies are the cause of thyroid overstimulation and were originally called long-acting thyroid stimulators due to their prolonged action. Here we report the successful cloning and characterization of a monoclonal antibody (MS-1) with TSHR-stimulating activity. The thyroid-stimulating activity of MS-1 was evident at IgG concentrations as low as...

  2. History and Practice: Antibodies in Infectious Diseases.

    Science.gov (United States)

    Hey, Adam

    2015-04-01

    Antibodies and passive antibody therapy in the treatment of infectious diseases is the story of a treatment concept which dates back more than 120 years, to the 1890s, when the use of serum from immunized animals provided the first effective treatment options against infections with Clostridium tetani and Corynebacterium diphtheriae. However, after the discovery of penicillin by Fleming in 1928, and the subsequent introduction of the much cheaper and safer antibiotics in the 1930s, serum therapy was largely abandoned. However, the broad and general use of antibiotics in human and veterinary medicine has resulted in the development of multi-resistant strains of bacteria with limited to no response to existing treatments and the need for alternative treatment options. The combined specificity and flexibility of antibody-based treatments makes them very valuable tools for designing specific antibody treatments to infectious agents. These attributes have already caused a revolution in new antibody-based treatments in oncology and inflammatory diseases, with many approved products. However, only one monoclonal antibody, palivizumab, for the prevention and treatment of respiratory syncytial virus, is approved for infectious diseases. The high cost of monoclonal antibody therapies, the need for parallel development of diagnostics, and the relatively small markets are major barriers for their development in the presence of cheap antibiotics. It is time to take a new and revised look into the future to find appropriate niches in infectious diseases where new antibody-based treatments or combinations with existing antibiotics, could prove their value and serve as stepping stones for broader acceptance of the potential for and value of these treatments. PMID:26104697

  3. Single-domain antibodies for brain targeting

    OpenAIRE

    Lalatsa, Katerina; Moreira Leite, Diana

    2014-01-01

    Smaller recombinant antibody fragments as single-domain antibodies (sdAbs) are emerging as credible alternatives because of their target specificity, high affinity, and cost-effective recombinant production. sdAbs have been forged into multivalent and multispecif ic therapeutics, or targeting moieties, that are able to shuttle their linked therapeutic cargo (i.e., drugs, nanoparticles, toxins, enzymes, and radionuclides) to the receptor of interest. Their ability to permeate across the blood ...

  4. Influenza-Specific Antibody-Dependent Phagocytosis

    OpenAIRE

    Ana-Sosa-Batiz, Fernanda; Vanderven, Hillary; Jegaskanda, Sinthujan; Johnston, Angus; Rockman, Steven; Laurie, Karen; Barr, Ian; Reading, Patrick; Lichtfuss, Marit; Stephen J Kent

    2016-01-01

    Background Immunity to human influenza A virus (IAV) infection is only partially understood. Broadly non-neutralizing antibodies may assist in reducing disease but have not been well characterized. Methods We measured internalization of opsonized, influenza protein-coated fluorescent beads and live IAV into a monocytic cell line to study antibody-dependent phagocytosis (ADP) against multiple influenza hemagglutinin (HA) subtypes. We analyzed influenza HA-specific ADP in healthy human donors, ...

  5. Clearance of pathological antibodies using biomimetic nanoparticles

    OpenAIRE

    Copp, Jonathan A.; Fang, Ronnie H.; Luk, Brian T.; Hu, Che-Ming J.; Gao, Weiwei; Zhang, Kang; Zhang, Liangfang

    2014-01-01

    The selective depletion of disease-causing antibodies using nanoparticles offers a new model in the management of type II immune hypersensitivity reactions. The demonstration of pathophysiologically inspired nanoengineering serves as a valuable prototype for additional therapeutic improvements with the goal of minimizing therapy-related adverse effects. Through the use of cell membrane-cloaked nanoparticles, nanoscale decoys with strong affinity to pathological antibodies can be administered ...

  6. Monoclonal antibodies to Bacteroides fragilis lipopolysaccharide.

    OpenAIRE

    Linko-Kettunen, L; Arstila, P; Jalkanen, M; Jousimies-Somer, H; Lassila, O; Lehtonen, O P; Weintraub, A; Viljanen, M K

    1984-01-01

    Monoclonal antibodies (MoAbs) to the lipopolysaccharide (LPS) of Bacteroides fragilis were produced by immunizing mice before hybridization with bacterial outer membranes solubilized with Triton X-100. Nineteen stabile clones were established. They all produced antibodies that reacted more strongly with purified B. fragilis LPS than with crude sonicated antigen in an enzyme immunoassay. Four MoAbs were studied by immunoblotting and enzyme immunoassay inhibition. Immunoblotting confirmed that ...

  7. Antibody-Conjugated Nanoparticles for Biomedical Applications

    Directory of Open Access Journals (Sweden)

    Manuel Arruebo

    2009-01-01

    Full Text Available Nanoscience and Nanotechnology have found their way into the fields of Biotechnology and Medicine. Nanoparticles by themselves offer specific physicochemical properties that they do not exhibit in bulk form, where materials show constant physical properties regardless of size. Antibodies are nanosize biological products that are part of the specific immune system. In addition to their own properties as pathogens or toxin neutralizers, as well as in the recruitment of immune elements (complement, improving phagocytosis, cytotoxicity antibody dependent by natural killer cells, etc., they could carry several elements (toxins, drugs, fluorochroms, or even nanoparticles, etc. and be used in several diagnostic procedures, or even in therapy to destroy a specific target. The conjugation of antibodies to nanoparticles can generate a product that combines the properties of both. For example, they can combine the small size of nanoparticles and their special thermal, imaging, drug carrier, or magnetic characteristics with the abilities of antibodies, such as specific and selective recognition. The hybrid product will show versatility and specificity. In this review, we analyse both antibodies and nanoparticles, focusing especially on the recent developments for antibody-conjugated nanoparticles, offering the researcher an overview of the different applications and possibilities of these hybrid carriers.

  8. Decay of maternal antibodies in broiler chickens.

    Science.gov (United States)

    Gharaibeh, Saad; Mahmoud, Kamel

    2013-09-01

    The objective of this study was to determine the decay rate of maternal antibodies against major broiler chicken pathogens. A total of 30 one-day-old broiler chicks were obtained from a commercial hatchery and reared in isolation. These chicks were retrieved from a parent flock that received a routine vaccination program. Chicks were bled at hatch and sequentially thereafter every 5 d through 30 d of age. Maternal antibody titers were measured by ELISA for avian encephalomyelitis (AEV), avian influenza virus (AIV), chicken anemia virus (CAV), infectious bursal disease virus (IBDV), infectious bronchitis virus (IBV), infectious laryngotracheitis virus (ILTV), Mycoplasma gallisepticum (MG), Mycoplasma synoviae (MS), and reovirus (Reo). Maternal antibody titers for Newcastle disease virus (NDV) were measured using a hemagglutination inhibition test. Half-life estimates of maternal antibody titers were 5.3, 4.2, 7, 5.1, 3.9, 3.8, 4.9, 4.1, 6.3, and 4.7 d for AEV, AIV, CAV, IBDV, IBV, ILTV, MG, MS, NDV, and Reo, respectively. The statistical analysis revealed significant differences among half-lives of maternal antibody titers against certain pathogens. Furthermore, all maternal antibody titers were depleted by 10 d of age except for IBDV. PMID:23960115

  9. Quality control of antibodies for assay development.

    Science.gov (United States)

    Schumacher, Sarah; Seitz, Harald

    2016-09-25

    Antibodies are used as powerful tools in basic research, for example, in biomarker identification, and in various forms for diagnostics, for example, identification of allergies or autoimmune diseases. Due to their robustness and ease of handling, immunoassays are favourite methods for investigation of various biological or medical questions. Nevertheless in many cases, additional analyses such as mass spectrometry are used to validate or confirm the results of immunoassays. To minimize the workload and to increase confidence in immunoassays, there are urgent needs for antibodies which are both highly specific and well validated. Unfortunately many commercially available antibodies are neither well characterized nor fully tested for cross-reactivities. Adequate quality control and validation of an antibody is time-consuming and can be frustrating. Such validation needs to be performed for every assay/application. However, where an antibody validation is successful, a highly specific and stable reagent will be on hand. This article describes the validation processes of antibodies, including some often neglected factors, as well as unspecific binding to other sample compounds in a multiparameter diagnostic assay. The validation consists of different immunological methods, with important assay controls, and is performed in relation to the development of a diagnostic test. PMID:26873787

  10. 21 CFR 866.5110 - Antiparietal antibody immunological test system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Antiparietal antibody immunological test system....5110 Antiparietal antibody immunological test system. (a) Identification. An antiparietal antibody... the specific antibody for gastric parietal cells in serum and other body fluids. Gastric...

  11. 21 CFR 866.5100 - Antinuclear antibody immunological test system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Antinuclear antibody immunological test system....5100 Antinuclear antibody immunological test system. (a) Identification. An antinuclear antibody... the autoimmune antibodies in serum, other body fluids, and tissues that react with cellular...

  12. Avian Diagnostic and Therapeutic Antibodies to Viral Emerging Pathogens

    Energy Technology Data Exchange (ETDEWEB)

    David Bradley

    2011-03-31

    During the current period the following key objectives were achieved: demonstration of high titer antibody production by geese following immunization with inactived H1N1 virus; completion of the epitope mapping of West Nile Virus-specific goose antibodies and initiation of epitope mapping of H1N1 flu-specific goose antibodies; advancement in scalable purification of goose antibodies.

  13. A multi-Fc-species system for recombinant antibody production

    OpenAIRE

    Nizak Clément; Vielemeyer Ole; El Marjou Ahmed; Moutel Sandrine; Benaroch Philippe; Dübel Stefan; Perez Franck

    2009-01-01

    Abstract Background Genomic, transcriptomic and proteomic projects often suffer from a lack of functional validation creating a strong demand for specific and versatile antibodies. Antibody phage display represents an attractive approach to select rapidly in vitro the equivalent of monoclonal antibodies, like single chain Fv antibodies, in an inexpensive and animal free way. However, so far, recombinant antibodies have not managed to impose themselves as efficient alternatives to natural anti...

  14. Antigen-Specific Antibody Glycosylation Is Regulated via Vaccination

    OpenAIRE

    Mahan, Alison E.; Jennewein, Madeleine F.; Suscovich, Todd; Dionne, Kendall; Tedesco, Jacquelynne; Chung, Amy W.; Streeck, Hendrik; Pau, Maria; Schuitemaker, Hanneke; Francis, Don; Fast, Patricia; Laufer, Dagna; Walker, Bruce D.; Baden, Lindsey; Barouch, Dan H.

    2016-01-01

    Antibody effector functions, such as antibody-dependent cellular cytotoxicity, complement deposition, and antibody-dependent phagocytosis, play a critical role in immunity against multiple pathogens, particularly in the absence of neutralizing activity. Two modifications to the IgG constant domain (Fc domain) regulate antibody functionality: changes in antibody subclass and changes in a single N-linked glycan located in the CH2 domain of the IgG Fc. Together, these modifications provide a spe...

  15. Stability of rhenium-188 labeled antibody

    International Nuclear Information System (INIS)

    For clinical application of beta-emitter labeled antibody, high specific activity is important. Carrier-free Re-188 from W-188/Re-188 generator is an ideal radionuclide for this purpose. However, low stability of Re-188 labeled antibody, especially in high specific activity, due to radiolytic decomposition by high energy (2.1 MeV) beta ray was problem. We studied the stability of Re-188 labeled antibody, and stabilizing effect of several nontoxic radical-quenching agents. Pre-reduced monoclonal antibody (CEA79.4) was labeled with Re-188 by incubating with generator-eluted Re-188-perrhenate in the presence of stannous tartrate for 2 hr at room temperature. Radiochemical purity of each preparation was determined by chromatography (ITLC-SG/acetone, ITLC-SG/Umezawa, Whatman No.1/saline). Human serum albumin was added to the labeled antibodies(2%). Stability of Re-188-CEA79.4 was investigated in the presence of vitamin C, ethanol, or Tween 80 as radical-quenching agents. Specific activities of 4.29∼5.11 MBq/μg were obtained. Labeling efficiencies were 88±4%(n=12). Very low stability after removal of stannous tartrate from the preparation was observed. If stored after purging with N2, all the preparations were stable for 10 hr. However, if contacted with air, stability decreased. Perrhenate and Re-188-tartrate was major impurity in declined preparation (12∼47 and 9∼38% each, after 10 hr). Colloid-formation was not a significant problem in all cases. Addition of vitamin C stabilized the labeled antibodies either under N2 or under air by reducing the formation of perrhenate. High specific activity Re-188 labeled antibody is unstable, especially, in the presence of oxygen. Addition of vitamin C increased the stability

  16. The antibody mining toolbox: an open source tool for the rapid analysis of antibody repertoires.

    Science.gov (United States)

    D'Angelo, Sara; Glanville, Jacob; Ferrara, Fortunato; Naranjo, Leslie; Gleasner, Cheryl D; Shen, Xiaohong; Bradbury, Andrew R M; Kiss, Csaba

    2014-01-01

    In vitro selection has been an essential tool in the development of recombinant antibodies against various antigen targets. Deep sequencing has recently been gaining ground as an alternative and valuable method to analyze such antibody selections. The analysis provides a novel and extremely detailed view of selected antibody populations, and allows the identification of specific antibodies using only sequencing data, potentially eliminating the need for expensive and laborious low-throughput screening methods such as enzyme-linked immunosorbant assay. The high cost and the need for bioinformatics experts and powerful computer clusters, however, have limited the general use of deep sequencing in antibody selections. Here, we describe the AbMining ToolBox, an open source software package for the straightforward analysis of antibody libraries sequenced by the three main next generation sequencing platforms (454, Ion Torrent, MiSeq). The ToolBox is able to identify heavy chain CDR3s as effectively as more computationally intense software, and can be easily adapted to analyze other portions of antibody variable genes, as well as the selection outputs of libraries based on different scaffolds. The software runs on all common operating systems (Microsoft Windows, Mac OS X, Linux), on standard personal computers, and sequence analysis of 1-2 million reads can be accomplished in 10-15 min, a fraction of the time of competing software. Use of the ToolBox will allow the average researcher to incorporate deep sequence analysis into routine selections from antibody display libraries. PMID:24423623

  17. Antibodies Produced in Response to Cryptococcus neoformans Pulmonary Infection in Mice Have Characteristics of Nonprotective Antibodies

    OpenAIRE

    Zaragoza, Oscar; Casadevall, Arturo

    2004-01-01

    Murine cryptocococcal pulmonary infection elicited serum immunoglobulin M (IgM) and IgG to the capsular polysaccharide, but only IgG stained yeast cells in alveoli. Both isotypes produced punctuate immunofluorescence patterns on yeast cells like those of nonprotective antibodies. The difficulties involved in associating humoral immunity with protection in murine cryptocococcal infection could reflect nonprotective antibody responses.

  18. Passive antibody transfer in chickens to model maternal antibody after avian influenza vaccination.

    Science.gov (United States)

    Faulkner, Olivia B; Estevez, Carlos; Yu, Qingzhong; Suarez, David L

    2013-04-15

    Birds transfer maternal antibodies (MAb) to their offspring through the egg yolk where the antibody is absorbed and enters the circulatory system. Maternal antibodies provide early protection from disease, but may interfere with the vaccination efficacy in the chick. MAb are thought to interfere with vaccine antigen processing that reduces the subsequent immune response. Once MAb titers are depleted, the chick will respond to vaccination, but they are also susceptible to viral infection. This study examines the effect of MAb on seroconversion to different viral-vectored avian influenza virus (AIV) vaccines. Chicks were given passively transferred antibodies (PTA) using AIV hyperimmunized serum, and subsequently vaccinated with a fowlpox-AIV recombinant vaccine (FPr) or a Newcastle disease virus-AIV recombinant vaccine (NDVr). Our results indicate that passively transferred antibodies led to significant reduction of seroconversion and clinical protection from virulent challenge in recombinant virus vaccinated chicks thus demonstrating maternal antibody interference to vaccination. The passive antibody transfer model system provides an important tool to evaluate maternal antibody interference to vaccination. PMID:23398721

  19. Antibody-Mediated Internalization of Infectious HIV-1 Virions Differs among Antibody Isotypes and Subclasses.

    Science.gov (United States)

    Tay, Matthew Zirui; Liu, Pinghuang; Williams, LaTonya D; McRaven, Michael D; Sawant, Sheetal; Gurley, Thaddeus C; Xu, Thomas T; Dennison, S Moses; Liao, Hua-Xin; Chenine, Agnès-Laurence; Alam, S Munir; Moody, M Anthony; Hope, Thomas J; Haynes, Barton F; Tomaras, Georgia D

    2016-08-01

    Emerging data support a role for antibody Fc-mediated antiviral activity in vaccine efficacy and in the control of HIV-1 replication by broadly neutralizing antibodies. Antibody-mediated virus internalization is an Fc-mediated function that may act at the portal of entry whereby effector cells may be triggered by pre-existing antibodies to prevent HIV-1 acquisition. Understanding the capacity of HIV-1 antibodies in mediating internalization of HIV-1 virions by primary monocytes is critical to understanding their full antiviral potency. Antibody isotypes/subclasses differ in functional profile, with consequences for their antiviral activity. For instance, in the RV144 vaccine trial that achieved partial efficacy, Env IgA correlated with increased risk of HIV-1 infection (i.e. decreased vaccine efficacy), whereas V1-V2 IgG3 correlated with decreased risk of HIV-1 infection (i.e. increased vaccine efficacy). Thus, understanding the different functional attributes of HIV-1 specific IgG1, IgG3 and IgA antibodies will help define the mechanisms of immune protection. Here, we utilized an in vitro flow cytometric method utilizing primary monocytes as phagocytes and infectious HIV-1 virions as targets to determine the capacity of Env IgA (IgA1, IgA2), IgG1 and IgG3 antibodies to mediate HIV-1 infectious virion internalization. Importantly, both broadly neutralizing antibodies (i.e. PG9, 2G12, CH31, VRC01 IgG) and non-broadly neutralizing antibodies (i.e. 7B2 mAb, mucosal HIV-1+ IgG) mediated internalization of HIV-1 virions. Furthermore, we found that Env IgG3 of multiple specificities (i.e. CD4bs, V1-V2 and gp41) mediated increased infectious virion internalization over Env IgG1 of the same specificity, while Env IgA mediated decreased infectious virion internalization compared to IgG1. These data demonstrate that antibody-mediated internalization of HIV-1 virions depends on antibody specificity and isotype. Evaluation of the phagocytic potency of vaccine

  20. Platform for high-throughput antibody selection using synthetically-designed antibody libraries.

    Science.gov (United States)

    Batonick, Melissa; Holland, Erika G; Busygina, Valeria; Alderman, Dawn; Kay, Brian K; Weiner, Michael P; Kiss, Margaret M

    2016-09-25

    Synthetic humanized antibody libraries are frequently generated by random incorporation of changes at multiple positions in the antibody hypervariable regions. Although these libraries have very large theoretical diversities (>10(20)), the practical diversity that can be achieved by transformation of Escherichia coli is limited to about 10(10). To constrain the practical diversity to sequences that more closely mimic the diversity of natural human antibodies, we generated a scFv phage library using entirely pre-defined complementarity determining regions (CDR). We have used this library to select for novel antibodies against four human protein targets and demonstrate that identification of enriched sequences at each of the six CDRs in early selection rounds can be used to reconstruct a consensus antibody with selectivity for the target. PMID:26607994

  1. Antibody induction versus placebo, no induction, or another type of antibody induction for liver transplant recipients

    DEFF Research Database (Denmark)

    Penninga, Luit; Wettergren, André; Wilson, Colin H;

    2014-01-01

    BACKGROUND: Liver transplantation is an established treatment option for end-stage liver failure. To date, no consensus has been reached on the use of immunosuppressive T-cell antibody induction for preventing rejection after liver transplantation. OBJECTIVES: To assess the benefits and harms of...... immunosuppressive T-cell specific antibody induction compared with placebo, no induction, or another type of T-cell specific antibody induction for prevention of acute rejection in liver transplant recipients. SEARCH METHODS: We searched The Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane......-cell specific antibody induction compared with placebo, no induction, or another type of antibody induction in liver transplant recipients. Our inclusion criteria stated that participants within each included trial should have received the same maintenance immunosuppressive therapy. We planned to include trials...

  2. Adaptive responses to antibody based therapy.

    Science.gov (United States)

    Rodems, Tamara S; Iida, Mari; Brand, Toni M; Pearson, Hannah E; Orbuch, Rachel A; Flanigan, Bailey G; Wheeler, Deric L

    2016-02-01

    Receptor tyrosine kinases (RTKs) represent a large class of protein kinases that span the cellular membrane. There are 58 human RTKs identified which are grouped into 20 distinct families based upon their ligand binding, sequence homology and structure. They are controlled by ligand binding which activates intrinsic tyrosine-kinase activity. This activity leads to the phosphorylation of distinct tyrosines on the cytoplasmic tail, leading to the activation of cell signaling cascades. These signaling cascades ultimately regulate cellular proliferation, apoptosis, migration, survival and homeostasis of the cell. The vast majority of RTKs have been directly tied to the etiology and progression of cancer. Thus, using antibodies to target RTKs as a cancer therapeutic strategy has been intensely pursued. Although antibodies against the epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2) have shown promise in the clinical arena, the development of both intrinsic and acquired resistance to antibody-based therapies is now well appreciated. In this review we provide an overview of the RTK family, the biology of EGFR and HER2, as well as an in-depth review of the adaptive responses undertaken by cells in response to antibody based therapies directed against these receptors. A greater understanding of these mechanisms and their relevance in human models will lead to molecular insights in overcoming and circumventing resistance to antibody based therapy. PMID:26808665

  3. Recombinant shark natural antibodies to thyroglobulin.

    Science.gov (United States)

    Schluter, Samuel F; Jensen, Ingvill; Ramsland, Paul A; Marchalonis, John J

    2005-01-01

    As cartilaginous fish are the vertebrates most distal from man to produce antibodies, fundamental information regarding conservation and variation of the antigen binding site should be gained by comparing the properties of antibodies directed against the same antigen from the two species. Since monoclonal cell lines cannot be generated using shark B cells, we isolated antigen binding recombinant single chain Fv antibodies (scFv) comprising of the complete variable regions from shark light and heavy chains. Thyroglobulin was used as the selecting antigen as both sharks and humans express natural antibodies to mammalian thyroglobulin in the absence of purposeful immunization. We report that recombinant sandbar shark (Carcharhinus plumbeus) scFvs that bind bovine thyroglobulin consist of heavy chain variable regions (VH) homologous to those of the human VHIII subset and light chain variable regions (VL) homologous to those of the human Vlambda6 subgroup. The homology within the frameworks is sufficient to enable the building of three-dimensional models of the shark VH/VL structure using established human structures as templates. In natural antibodies of both species, the major variability lies in the third complementarity determining region (CDR3) of both VH and VL. PMID:15954089

  4. Cytolytic antibodies to melanocytes in vitiligo.

    Science.gov (United States)

    Cui, J; Arita, Y; Bystryn, J C

    1993-06-01

    Patients with vitiligo have been found to have circulating antibodies to pigment cells. To evaluate the functional activity of these antibodies, a highly sensitive europium release assay was used to compare complement-mediated cytolysis of human melanocytes by sera of 56 patients with vitiligo (20 with active disease, 25 with inactive disease, 11 with unidentified disease activity) and 47 control individuals. Significant melanocyte lysis was mediated by 32 (57%) of the patients with vitiligo but by only three (6%) of the control sera (p < 0.001), and by 17 (85%) of 20 patients with active vitiligo versus 11 (44%) of 25 patients with inactive disease (p < 0.025). Mean melanocyte lysis by vitiligo sera was 24% versus 6% by control sera (p < 0.0001). A subset of 12 vitiligo sera with high titers of cytolytic antibodies to melanocytes (34% mean cytolysis) reacted minimally (< 2% mean cytolysis) to a panel of control cells that included human and murine melanomas, human fibroblasts, lung carcinoma, and rhabdomyosarcoma. These findings indicate that antibodies present in patients with vitiligo have the functional ability to selectively kill melanocytes and are more common in active disease. These observations support, but do not prove, the hypothesis that vitiligo is an autoimmune disease and that anti-pigment cell antibodies have a role in inducing the disease. PMID:8496621

  5. Radiation safety issues related to radiolabeled antibodies

    International Nuclear Information System (INIS)

    Techniques related to the use of radiolabeled antibodies in humans are reviewed and evaluated in this report. It is intended as an informational resource for the US Nuclear Regulatory Commission (NRC) and NRC licensees. Descriptions of techniques and health and safety issues are provided. Principal methods for labeling antibodies are summarized to help identify related radiation safety problems in the preparation of dosages for administration to patients. The descriptions are derived from an extensive literature review and consultations with experts in the field. A glossary of terms and acronyms is also included. An assessment was made of the extent of the involvement of organizations (other than the NRC) with safety issues related to radiolabeled antibodies, in order to identify regulatory issues which require attention. Federal regulations and guides were also reviewed for their relevance. A few (but significant) differences between the use of common radiopharmaceuticals and radiolabeled antibodies were observed. The clearance rate of whole, radiolabeled immunoglobulin is somewhat slower than common radiopharmaceuticals, and new methods of administration are being used. New nuclides are being used or considered (e.g., Re-186 and At-211) for labeling antibodies. Some of these nuclides present new dosimetry, instrument calibration, and patient management problems. Subjects related to radiation safety that require additional research are identified. 149 refs., 3 figs., 20 tabs

  6. Antibody penetration into living cells. V. Interference between two fc gamma receptor-mediated functions: antibody penetration and antibody-dependent cellular cytotoxicity.

    Science.gov (United States)

    Llerena, J M; Ruíz-Argüelles, A; Alarcón-Segovia, D; Llorente, L; Díaz-Jouanen, E

    1981-01-01

    The same Fc gamma receptor appears to be shared for two important phenomena: antibody-dependent cellular cytotoxicity (ADCC) and antibody penetration into living cells. ADCC is inhibited through interaction with the Fc gamma receptor during the antibody penetration process, indicating that both mechanisms may modulate each other in vitro. PMID:6972908

  7. Back to the future: recombinant polyclonal antibody therapeutics.

    Science.gov (United States)

    Wang, Xian-Zhe; Coljee, Vincent W; Maynard, Jennifer A

    2013-11-01

    Antibody therapeutics are one of the fastest growing classes of pharmaceuticals, with an annual US market over $20 billion, developed to treat a variety of diseases including cancer, auto-immune and infectious diseases. Most are currently administered as a single molecule to treat a single disease, however there is mounting evidence that cocktails of multiple antibodies, each with a unique binding specificity and protective mechanism, may improve clinical efficacy. Here, we review progress in the development of oligoclonal combinations of antibodies to treat disease, focusing on identification of synergistic antibodies. We then discuss the application of modern antibody engineering technologies to produce highly potent antibody preparations, including oligoclonal antibody cocktails and truly recombinant polyclonal antibodies. Specific examples illustrating the synergy conferred by multiple antibodies will be provided for diseases caused by botulinum toxin, cancer and immune thrombocytopenia. The bioprocessing and regulatory options for these preparations will be discussed. PMID:24443710

  8. Characterization of monoclonal antibodies directed against human thyroid stimulating hormone

    International Nuclear Information System (INIS)

    Monoclonal antibodies directed against human thyroid stimulating hormone (TSH) were obtained from hybrid myelomas, following fusion of mouse NSI myeloma cells with mouse spleen cells. Ten different antibodies were obtained from 4 separate fusions. Eight antibodies were of the IgG1 subclass. Affinities of antibodies for TSH were in the range 2 x 108-5 x 1010 M-1. Five of the antibodies were specific for TSH and did not react with LH, FSH or hCG. The remaining antibodies reacted with all these hormones and were assumed to recognise their common (α) subunit. The 5 specific antibodies fell into 3 subgroups recognising distinct antigenic determinants, whereas the 5 non-specific antibodies recognised a single determinant or closely related set of sites. It is concluded that these antibodies should be valuable reagents for use in sensitive and specific two-site immunoradiometric assays. (Auth.)

  9. Method for preparation of single chain antibodies

    Science.gov (United States)

    Cheung, Nai-Kong V.; Guo, Hong-fen

    2012-04-03

    This invention provides a method for identifying cells expressing a target single chain antibody (scFv) directed against a target antigen from a collection of cells that includes cells that do not express the target scFv, comprising the step of combining the collection of cells with an anti-idiotype directed to an antibody specific for the target antigen and detecting interaction, if any, of the anti-idiotype with the cells, wherein the occurrence of an interaction identifies the cell as one which expresses the target scFv. This invention also provides a method for making a single chain antibody (scFv) directed against an antigen, wherein the selection of clones is made based upon interaction of those clones with an appropriate anti-idiotype, and heretofore inaccessible scFv so made. This invention provides the above methods or any combination thereof. Finally, this invention provides various uses of these methods.

  10. Engineered antibodies for molecular imaging of cancer.

    Science.gov (United States)

    Wu, Anna M

    2014-01-01

    Antibody technology has transformed drug development, providing robust approaches to producing highly targeted and active therapeutics that can routinely be advanced through clinical evaluation and registration. In parallel, there is an emerging need to access similarly targeted agents for diagnostic purposes, including non-invasive imaging in preclinical models and patients. Antibody engineering enables modification of key properties (immunogenicity, valency, biological inertness, pharmacokinetics, clearance route, site-specific conjugation) in order to produce targeting agents optimized for molecular imaging. Expanded availability of positron-emitting radionuclides has led to a resurgence of interest and applications of immunoPET (immuno-positron emission tomography). Molecular imaging using engineered antibodies and fragments provides a general approach for assessing cell surface phenotype in vivo and stands to play an increasingly important role in cancer diagnosis, treatment selection, and monitoring of molecularly targeted therapeutics. PMID:24091005

  11. Imaging spectrum of primary antiphospholipid antibody syndrome

    International Nuclear Information System (INIS)

    Antiphospholipid antibody syndrome is recognized as one of the most important causes of hypercoagulability. It can be clinically diagnosed if patients have experienced unexplained recurrent venous or arterial thrombosis, recurrent fetal loss, or thrombocytopenia in the presence of circulating autoantibodies to phospholipids, such as anticardiolipin antibody or lupus anticoagulant. Approximately half of all patients with this syndrome do not have associated systemic disease, and their condition is described as primary antiphospholipid antibody syndrome (PAPS). In the remainder, the syndrome is accompanied by systemic lupus erythematosus or other connective tissue diseases, and is known as secondary antiphospholipid syndrome (1). The purpose of this paper is to illustrate the systemic manifestation of PAPS, focusing on the radiological findings of CT, MR and angiography in clinically proven patients. (author). 8 refs., 10 figs

  12. Imaging spectrum of primary antiphospholipid antibody syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Kwon Ha; Won, Jong Jin [Wonkwang University Hospital, Iksan (Korea, Republic of); Ha, Hyun Kwon; Kim, Jung Hoon; Kim, Jeong Gon; Ki, Won Woo; Kim, Pyo Nyun; Lee, Moon Gyu; Auh, Yong Ho [Asan Medical Center, Seoul (Korea, Republic of)

    1998-04-01

    Antiphospholipid antibody syndrome is recognized as one of the most important causes of hypercoagulability. It can be clinically diagnosed if patients have experienced unexplained recurrent venous or arterial thrombosis, recurrent fetal loss, or thrombocytopenia in the presence of circulating autoantibodies to phospholipids, such as anticardiolipin antibody or lupus anticoagulant. Approximately half of all patients with this syndrome do not have associated systemic disease, and their condition is described as primary antiphospholipid antibody syndrome (PAPS). In the remainder, the syndrome is accompanied by systemic lupus erythematosus or other connective tissue diseases, and is known as secondary antiphospholipid syndrome (1). The purpose of this paper is to illustrate the systemic manifestation of PAPS, focusing on the radiological findings of CT, MR and angiography in clinically proven patients. (author). 8 refs., 10 figs.

  13. Origin and pathogenesis of antiphospholipid antibodies

    Directory of Open Access Journals (Sweden)

    C.M. Celli

    1998-06-01

    Full Text Available Antiphospholipid antibodies (aPL are a heterogeneous group of antibodies that are detected in the serum of patients with a variety of conditions, including autoimmune (systemic lupus erythematosus, infectious (syphilis, AIDS and lymphoproliferative disorders (paraproteinemia, myeloma, lymphocytic leukemias. Thrombosis, thrombocytopenia, recurrent fetal loss and other clinical complications are currently associated with a subgroup of aPL designating the antiphospholipid syndrome. In contrast, aPL from patients with infectious disorders are not associated with any clinical manifestation. These findings led to increased interest in the origin and pathogenesis of aPL. Here we present the clinical features of the antiphospholipid syndrome and review the origin of aPL, the characteristics of experimentally induced aPL and their historical background. Within this context, we discuss the most probable pathogenic mechanisms induced by these antibodies.

  14. Antibody engineering & therapeutics, the annual meeting of the antibody society December 7–10, 2015, San Diego, CA, USA

    Science.gov (United States)

    Pauthner, Matthias; Yeung, Jenny; Ullman, Chris; Bakker, Joost; Wurch, Thierry; Reichert, Janice M.; Lund-Johansen, Fridtjof; Bradbury, Andrew R.M.; Carter, Paul J.; Melis, Joost P.M.

    2016-01-01

    ABSTRACT The 26th Antibody Engineering & Therapeutics meeting, the annual meeting of The Antibody Society united over 800 participants from all over the world in San Diego from 6–10 December 2015. The latest innovations and advances in antibody research and development were discussed, covering a myriad of antibody-related topics by more than 100 speakers, who were carefully selected by The Antibody Society. As a prelude, attendees could join the pre-conference training course focusing, among others, on the engineering and enhancement of antibodies and antibody-like scaffolds, bispecific antibody engineering and adaptation to generate chimeric antigen receptor constructs. The main event covered 4 d of scientific sessions that included antibody effector functions, reproducibility of research and diagnostic antibodies, new developments in antibody-drug conjugates (ADCs), preclinical and clinical ADC data, new technologies and applications for bispecific antibodies, antibody therapeutics for non-cancer and orphan indications, antibodies to harness the cellular immune system, building comprehensive IgVH-gene repertoires through discovering, confirming and cataloging new germline IgVH genes, and overcoming resistance to clinical immunotherapy. The Antibody Society's special session focused on “Antibodies to watch” in 2016. Another special session put the spotlight on the limitations of the new definitions for the assignment of antibody international nonproprietary names introduced by the World Health Organization. The convention concluded with workshops on computational antibody design and on the promise and challenges of using next-generation sequencing for antibody discovery and engineering from synthetic and in vivo libraries. PMID:26909869

  15. Utility of feline coronavirus antibody tests.

    Science.gov (United States)

    Addie, Diane D; le Poder, Sophie; Burr, Paul; Decaro, Nicola; Graham, Elizabeth; Hofmann-Lehmann, Regina; Jarrett, Oswald; McDonald, Michael; Meli, Marina L

    2015-02-01

    Eight different tests for antibodies to feline coronavirus (FCoV) were evaluated for attributes that are important in situations in veterinary practice. We compared four indirect immunofluorescent antibody tests (IFAT), one enzyme-linked immunosorbent assay (ELISA) (FCoV Immunocomb; Biogal) and three rapid immunochromatographic (RIM) tests against a panel of samples designated by consensus as positive or negative. Specificity was 100% for all but the two IFATs based on transmissible gastroenteritis virus (TGEV), at 83.3% and 97.5%. The IFAT and ELISA tests were best for obtaining an antibody titre and for working in the presence of virus. The RIM tests were the best for obtaining a result quickly (10-15 mins); of these, the Speed F-Corona was the most sensitive, at 92.4%, followed by FASTest feline infectious peritonitis (FIP; 84.6%) and Anigen Rapid FCoV antibody test (64.1%). Sensitivity was 100% for the ELISA, one FCoV IFAT and one TGEV IFAT; and 98.2% for a second TGEV IFA and 96.1% for a second FCoV IFAT. All tests worked with effusions, even when only blood products were stipulated in the instruction manual. The ELISA and Anigen RIM tests were best for small quantities of sample. The most appropriate FCoV antibody test to use depends on the reason for testing: in excluding a diagnosis of FIP, sensitivity, specificity, small sample quantity, rapidity and ability to work in the presence of virus all matter. For FCoV screening, speed and sensitivity are important, and for FCoV elimination antibody titre is essential. PMID:24966245

  16. In vivo modulators of antibody kinetics

    International Nuclear Information System (INIS)

    The aim of the present study was to summarize the effect of in vivo modulation of antibody kinetics and to present new data on the in vivo effect of the cell membrane active detergent Tween 80 and the cytokine interleukin-2 (IL-2) on the accumulation and clearance of a radioactive antibody. Mice bearing Lewis lung carcinoma xenografts and rats bearing DMBA-induced mammary carcinomas were studied after injecting I-125 labeled IgG1 monoclonal antibody (3c4c7g6) raised against a tyrosine kinase receptor protein Tie. Expression of Tie is known to be abundant in vascular endothelia and possibly related to malignant angiogenesis. Tween 80 was administered intratumorally (0.04% of tumor volume), whereas IL-2 was administered intraperitoneally. In the Lewis lung tumor model, the absolute tumor uptake varied between 2 and 5% ID/g, and maximum uptake was achieved after 24 h with Tween, and after 48 h without Tween. Tween manipulation did not increase the uptake in any normal organ, but it enhanced antibody clearance form the blood. In the DMBA rat model, IL-2 had no effect on blood clearance, but enhanced the uptake of Tie antibody into the tumor from 2.5-0.9 to 4.5-0.4% ID/g at 48 h. These data indicate that antibody biodistribution and pharmacokinetics can be modulated by a surface detergent and a cytokine, giving decreased exposure to critical organs, and increased uptake into the tumor. This type of manipulation provides an opportunity to optimize radioimmunotherapy. (orig.)

  17. Dissection of an antibody-catalyzed reaction.

    OpenAIRE

    Stewart, J D; Krebs, J F; Siuzdak, G; Berdis, A J; Smithrud, D B; Benkovic, S J

    1994-01-01

    Antibody 43C9 accelerates the hydrolysis of a p-nitroanilide by a factor of 2.5 x 10(5) over the background rate in addition to catalyzing the hydrolysis of a series of aromatic esters. Since this represents one of the largest rate accelerations achieved with an antibody, we have undertaken a series of studies aimed at uncovering the catalytic mechanism of 43C9. The immunogen, a phosphonamidate, was designed to mimic the geometric and electronic characteristics of the tetrahedral intermediate...

  18. Antibodies for detecting and quantifying anticoagulant agents

    OpenAIRE

    Salvador, Juan Pablo; Marco, María Pilar

    2012-01-01

    [EN] The present invention relates to the design of haptens that are structurally related to coumarin oral anticoagulant compounds (COAC), to be used for the production of specific antibodies against said type of substances and the subsequent use thereof for the development of diagnosis tools for use in laboratories or in point-of-care (PoC) devices. In particular, the produced antibodies have been used to develop a diagnosis tool that enables the plasma levels of COAC to be quantified in pat...

  19. Immunoglobulin A antibodies to Helicobacter pylori.

    OpenAIRE

    Jaskowski, T D; Martins, T B; Hill, H R; Litwin, C M

    1997-01-01

    Serological testing for immunoglobulin G (IgG) antibodies to Helicobacter pylori has proven useful in supporting the diagnosis of infection with this organism, but the clinical value of IgA antibodies in H. pylori-related gastritis remains controversial. The purpose of our study was to determine the frequency of IgA-positive IgG-negative patients with symptoms of gastrointestinal (GI) disorders, thus assessing the clinical utility of IgA testing for H. pylori-related gastritis. It was found p...

  20. Basic immunology of antibody targeted radiotherapy

    International Nuclear Information System (INIS)

    Antibody targeted radiotherapy brings an important new treatment modality to Radiation oncology clinic. Radiation dose to tumor and normal tissues are determined by a complex interplay of antibody, antigen, tumor, radionuclide, and host-related factors. A basic understanding of these immunologic and physiologic factors is important to optimally utilize this therapy in the clinic. Preclinical and clinical studies need to be continued to broaden our understanding and to develop new strategies to further improve the efficacy of this promising form of targeted therapy

  1. Radiolabelling of monoclonal antibodies for radiotherapy. Thailand

    International Nuclear Information System (INIS)

    Nuclear medicine is now playing a great role not only in diagnostic application but also in therapy of cancer patients. Under the concept of targeted radiotherapy, a number of radiopharmaceuticals based on radiolabelled biomolecules had been evaluated for treatment of cancer by many investigators. Of these, monoclonal antibodies and some small specific peptides labelled with beta emitting radiometals such as Sm-153, Re-186, Re-188 or Y-90, are being introduced into clinical trials. The objective of this project is to develop laboratory procedures to label monoclonal antibodies, peptide or other proteins with beta emitting radionuclides to prepare radiopharmaceuticals for therapeutic purpose

  2. Radiolabelling of monoclonal antibodies for radiotherapy

    International Nuclear Information System (INIS)

    Nuclear medicine is now playing a great role not only in diagnostic application but also in therapy of cancer patients. Under the concept of targeted radiotherapy, a number of radiopharmaceuticals based on radiolabelled biomolecules had been evaluated for treatment of cancer by many investigators. Of these, monoclonal antibodies and some small specific peptides labelled with beta emitting radiometals such as Sm-153, Re-186, Re-188 or Y-90, are being introduced into clinical trials. The objective of this project is to develop laboratory procedures to label monoclonal antibodies, peptide or other proteins with beta emitting radionuclides to prepare radiopharmaceuticals for therapeutic purpose

  3. Measurement of tumour reactive antibody and antibody conjugate by competition, quantitated by flow cytofluorimetry.

    Science.gov (United States)

    Robins, R A; Laxton, R R; Garnett, M; Price, M R; Baldwin, R W

    1986-06-24

    Binding of unlabelled monoclonal antibody preparations has been assessed by competition at saturation with fluorochrome labelled homologous antibody for binding to antigen bearing target cells. The extent of competition was measured by quantitative flow cytofluorimetry, and simple mathematical procedures have been developed to allow the interpretation of competition data in terms of antibody binding activity. In the system studied, non-specific (non-competitive) fluorescence was minimal, but an iterative method to calculate its contribution to the measured signal is given. This approach has the advantage that the antibody preparation to be tested does not need to be labelled or modified; this is particularly important when evaluating the binding activity of therapeutic antibody conjugates. Comparison with a well characterized standard antibody preparation provides a rapid, sensitive and accurate quality control procedure. This test is also simple to perform, requiring only the mixing of labelled and unlabelled antibodies with target cells, a single incubation, followed by analysis without washing of the target cells. PMID:2424997

  4. [Inhibition of adenovirus reproduction in cell culture by specific antibodies].

    Science.gov (United States)

    Povnytsia, O Iu; Nosach, L M; Zhovnovata, V L; Zahorodnia, S D; Vantsak, N P; Tokarchuk, L V; Polishchuk, O M; Diachenko, N S

    2009-01-01

    The capacity of specific antibodies to inhibit the reproduction of homo- and heterologous adenoviruses in Hela cell added to culture medium after virus adsorption was studied. The inhibiting effect of polyclonal antivirus and monospecific antihexone antibodies to homo- and heterologous adenoviruses was shown. The effect was more expressed when using antibodies to homologous antibodies. The intensity of inhibition depended on antibodies concentration in the medium and infecting dose of the virus. Essential reduction of the quantity of infected cells and a decrease of the titer of adenovirus synthesized in the presence of homo- and heterologous antibodies was shown but adenovirus reproduction was not inhibited completely. PMID:19663330

  5. Antibody-mediated immune suppression is improved when blends of anti-RBC monoclonal antibodies are used in mice.

    Science.gov (United States)

    Bernardo, Lidice; Amash, Alaa; Marjoram, Danielle; Lazarus, Alan H

    2016-08-25

    Although the prevention of hemolytic disease of the fetus and newborn is highly effective using polyclonal anti-D, a recombinant alternative is long overdue. Unfortunately, anti-D monoclonal antibodies have been, at best, disappointing. To determine the primary attribute defining an optimal antibody, we assessed suppression of murine red blood cell (RBC) immunization by single-monoclonal antibodies vs defined blends of subtype-matched antibodies. Allogeneic RBCs expressing the HOD antigen (hen egg lysozyme [HEL]-ovalbumin-human transmembrane Duffy(b)) were transfused into naïve mice alone or together with selected combinations of HEL-specific antibodies, and the resulting suppressive effect was assessed by evaluating the antibody response. Polyclonal HEL antibodies dramatically inhibited the antibody response to the HOD antigen, whereas single-monoclonal HEL antibodies were less effective despite the use of saturating doses. A blend of monoclonal HEL-specific antibodies reactive with different HEL epitopes significantly increased the suppressive effect, whereas a blend of monoclonal antibodies that block each other's binding to the HEL protein did not increase suppression. In conclusion, these data show that polyclonal antibodies are superior to monoclonal antibodies at suppressing the immune response to the HOD cells, a feature that can be completely recapitulated using monoclonal antibodies to different epitopes. PMID:27330002

  6. Treatment of leukemia with radiolabeled monoclonal antibodies.

    Science.gov (United States)

    Sgouros, G; Scheinberg, D A

    1993-01-01

    In contrast to radioimmunotherapy of solid disease, wherein the primary obstacle to success is access of radiolabeled antibody to antigen-positive cells, in the treatment of leukemia delivering a lethal absorbed dose to the isolated cell appears to be the primary obstacle. The isolated cell is defined as one that is exposed only to self-irradiation (from internalized or surface-bound radiolabeled antibody) and to irradiation from free antibody in the blood. It is isolated in the sense that the particulate (beta, electron, alpha) emissions from its nearest neighboring antigen-positive cell do not contribute to its absorbed dose. Disease in the bone marrow and other tissues, since it is confined to a smaller volume, is more easily eradicated because the absorbed dose to a given cell nucleus is enhanced by emissions from adjacent cells (a smaller fraction of the emission energy is 'wasted'). The optimization simulations presented above for the M195 antibody suggest that the optimum dose of antibody that should be administered is that required to yield a concentration within the distribution volume of the antibody that is approximately equal to the concentration of antigen sites as determined by the tumor burden. Although not specifically considered in the modeling example presented above, antibody internalization and catabolism may be expected to play an important role in radioimmunotherapy treatment planning of leukemia. Depending upon the kinetics of internalization and catabolism, the absorbed dose to the red marrow and to antigen-positive cells may be reduced considerably, since catabolism, assuming that it is followed by rapid extrusion of the radioactive label, would decrease the cells' exposure time considerably. The recently demonstrated effectiveness of radioimmunotherapy in certain cases of B-cell lymphoma and in reducing tumor burden in acute myelogenous leukemia suggests that radioimmunotherapy is beginning to fulfill the promise held when it was initially

  7. Anti Rh Hemolytic Disease due to Anti C Antibody: Is Testing for Anti D Antibodies Enough?

    OpenAIRE

    Negi, Gita; Singh, Gaur Dushyant

    2011-01-01

    Rh blood group system is a complex blood group system. Rh antibodies are produced in Rh negative individuals following exposure to foreign RBCs after transfusion or pregnancy. Anti C is a rare cause of hemolytic disease of newborn and is very scarcely reported in the literature. The aim of the present case report of Hemolytic disease caused by Anti C antibody is to bring out the fact that antibodies other than anti D should be considered in cases that give a suggestive history but no evidence...

  8. Phase Transitions in Antibody Solutions: from Pharmaceuticals to Human Disease

    Science.gov (United States)

    Wang, Ying; Lomakin, Aleksey; Benedek, George; Dana Farber Cancer Institute Collaboration; Amgen Inc. Collaboration

    2014-03-01

    Antibodies are very important proteins. Natural antibodies play essential role in the immune system of human body. Pharmaceutical antibodies are used as drugs. Antibodies are also indispensable tools in biomedical research and diagnostics. Recently, a number of observations of phase transitions of pharmaceutical antibodies have been reported. These phase transitions are undesirable from the perspective of colloid stability of drug solutions in processing and storage, but can be used for protein purification, X-ray crystallography, and improving pharmokinetics of drugs. Phase transitions of antibodies can also take place in human body, particularly in multiple myeloma patients who overproduce monoclonal antibodies. These antibodies, in some cases, crystallize at body temperature and cause severe complications called cryoglobulinemia. I will present the results of our current studies on phase transitions of both pharmaceutical antibodies and cryoglobulinemia-associated antibodies. These studies have shown that different antibodies have different propensity to undergo phase transitions, but their phase behavior has universal features which are remarkably different from those of spherical proteins. I will discuss how studies of phase behavior can be useful in assessing colloid stability of pharmaceutical antibodies and in early diagnostics of cryoglobulinemia, as well as general implications of the fact that some antibodies can precipitate at physiological conditions.

  9. Immunohistochemical diagnosis of fusariosis with monoclonal antibodies

    DEFF Research Database (Denmark)

    Jensen, H.E.; Aalbæk, B.; Jungersen, Gregers; Hartvig, T.; Moser, C.; Rozell, B.L.; Blennow, O.

    establishing an accurate diagnosis. Although molecular techniques (e.g. in situ hybridization and PCR) have been explored for diagnostic use, the development of specific monoclonal antibodies (Mabs) for immunohistochemical identification of Fusarium spp. will extend the availability of diagnostic options for...

  10. Conjugates of monoclonal antibodies and chelating polymers

    International Nuclear Information System (INIS)

    The primary purpose of protein modification with chelating polymers is to prepare monoclonal antibodies labeled with heavy metal isotopes (alpha-, beta-, and gamma-emitting metal and paramagnetic ions for NMR tomography). Conventional binding of metals to proteins via chelating agents directly coupled to proteins does not permit binding of a large number of metal atoms per protein molecule without causing alterations in the specific properties of the protein molecules. On the other hand, metal ion binding to proteins via intermediate chelating polymers should permit binding of several dozens of the metal atoms per protein molecule without affect the specific properties adversely. Moreover, the biodistribution and clearance rates can be regulated by varying the polymer properties. Modified antibodies may be used successfully in nuclear and NMR diagnostic applications and in radiotherapy. Possible applications of this approach shall be demonstrated with monoclonal antibody R11D10 for visualization of acute myocardial infarction. Use of this modification with other monoclonal antibodies is also discussed. The chemistry of protein modification with these polymers is presented

  11. Production of monoclonal antibodies against canine leukocytes.

    Science.gov (United States)

    Aguiar, Paulo Henrique Palis; Borges dos Santos, Roberto Robson; Lima, Carla Andrade; Rios de Sousa Gomes, Hilton; Larangeira, Daniela Farias; Santos, Patrícia Meira; Barrouin-Melo, Stella Maria; Conrado dos-Santos, Washington Luis; Pontes-de-Carvalho, Lain

    2004-04-01

    A panel of anti-canine leukocyte monoclonal antibodies (MAbs) was produced by immunizing BALB/c mice with canine peripheral blood mononuclear cells (PBMC), either resting or stimulated with concanavalin A (ConA). Three out of 28 clones-IH1, AB6, and HG6-screened by ELISA and producing antibody with the highest specificity for canine cell immunostaining, were subjected to three subsequent subcloning steps by limiting dilution, and selected for further characterization. These MAbs belonged to IgG1 (HG6 and IH1) and IgG2a (AB6) isotypes. The distribution of cell populations expressing the antigen recognized by the antibodies was identified by indirect immunoflorescence on canine PBMC and on tissue sections of lymph node, spleen, liver and skin. The possible crossreactivity with human PBMC was also examined in immunocytochemistry. One of the antibodies specifically recognized macrophages. The MAbs presented here can be foreseen as possible valuable diagnostic and research tools to study immune functions in dogs. PMID:15165486

  12. Monoclonal antibodies against chicken interleukin-6

    Science.gov (United States)

    Monoclonal antibodies (mAb) were produced against a recombinant (r) chicken interleukin-6 (IL-6). Eight mAbs that were produced were tested for isotype; ability to inhibit recombinant forms of chicken (ch), human (h) and murine (m) IL-6; and recognition of rchIL-6 by Western immunoblotting. The mA...

  13. Dengue Antibody Prevalence in German Travelers

    OpenAIRE

    Wichmann, Ole; Lauschke, Annekathrin; Frank, Christina; Shu, Pei-Yun; Niedrig, Matthias; Huang, Jyh-Hsiung; Stark, Klaus; Jelinek, Tomas

    2005-01-01

    We studied 2,259 German citizens after they returned from dengue-endemic countries from 1996 to 2004. Serotype-specific dengue antibodies indicated acute infections in 51 (4.7%) travelers with recent fever and 13 (1.1%) travelers with no recent fever, depending largely on destination and epidemic activity in the countries visited.

  14. Conformational Isomerism Can Limit Antibody Catalysis

    Energy Technology Data Exchange (ETDEWEB)

    Debler, E.W.; Muller, R.; Hilvert, D.; Wilson, I.A.

    2009-05-14

    Ligand binding to enzymes and antibodies is often accompanied by protein conformational changes. Although such structural adjustments may be conducive to enzyme catalysis, much less is known about their effect on reactions promoted by engineered catalytic antibodies. Crystallographic and pre-steady state kinetic analyses of antibody 34E4, which efficiently promotes the conversion of benzisoxazoles to salicylonitriles, show that the resting catalyst adopts two interconverting active-site conformations, only one of which is competent to bind substrate. In the predominant isomer, the indole side chain of Trp{sup L91} occupies the binding site and blocks ligand access. Slow conformational isomerization of this residue, on the same time scale as catalytic turnover, creates a deep and narrow binding site that can accommodate substrate and promote proton transfer using Glu{sup H50} as a carboxylate base. Although 34E4 is among the best catalysts for the deprotonation of benzisoxazoles, its efficiency appears to be significantly limited by this conformational plasticity of its active site. Future efforts to improve this antibody might profitably focus on stabilizing the active conformation of the catalyst. Analogous strategies may also be relevant to other engineered proteins that are limited by an unfavorable conformational pre-equilibrium.

  15. IgA Antibodies in Rett Syndrome

    Science.gov (United States)

    Reichelt, K. L.; Skjeldal, O.

    2006-01-01

    The level of IgA antibodies to gluten and gliadin proteins found in grains and to casein found in milk, as well as the level of IgG to gluten and gliadin, have been examined in 23 girls with Rett syndrome and 53 controls. Highly statistically significant increases were found for the Rett population compared to the controls. The reason for this…

  16. Developing recombinant antibodies for biomarker detection

    Energy Technology Data Exchange (ETDEWEB)

    Baird, Cheryl L.; Fischer, Christopher J.; Pefaur, Noah B.; Miller, Keith D.; Kagen, Jacob; Srivastava, Sudhir; Rodland, Karin D.

    2010-10-01

    Monoclonal antibodies (mAbs) have an essential role in biomarker validation and diagnostic assays. A barrier to pursuing these applications is the reliance on immunization and hybridomas to produce mAbs, which is time-consuming and may not yield the desired mAb. We recommend a process flow for affinity reagent production that utilizes combinatorial protein display systems (eg, yeast surface display or phage display) rather than hybridomas. These systems link a selectable phenotype-binding conferred by an antibody fragment-with a means for recovering the encoding gene. Recombinant libraries obtained from immunizations can produce high-affinity antibodies (<10 nM) more quickly than other methods. Non-immune libraries provide an alternate route when immunizations are not possible, or when suitable mAbs are not recovered from an immune library. Directed molecular evolution (DME) is an integral part of optimizing mAbs obtained from combinatorial protein display, but can also be used on hybridoma-derived mAbs. Variants can easily be obtained and screened to increase the affinity of the parent mAb (affinity maturation). We discuss examples where DME has been used to tailor affinity reagents to specific applications. Combinatorial protein display also provides an accessible method for identifying antibody pairs, which are necessary for sandwich-type diagnostic assays.

  17. Ebola Virus Antibodies in Fruit Bats, Bangladesh

    OpenAIRE

    Kevin J Olival; Islam, Ariful; YU, Meng; Anthony, Simon J.; Epstein, Jonathan H.; Khan, Shahneaz Ali; Khan, Salah Uddin; Crameri, Gary; Wang, Lin-Fa; Lipkin, W. Ian; Luby, Stephen P.; Daszak, Peter

    2013-01-01

    To determine geographic range for Ebola virus, we tested 276 bats in Bangladesh. Five (3.5%) bats were positive for antibodies against Ebola Zaire and Reston viruses; no virus was detected by PCR. These bats might be a reservoir for Ebola or Ebola-like viruses, and extend the range of filoviruses to mainland Asia.

  18. JDIP Genomics, Antibodies, and Proteomics Core Update

    Science.gov (United States)

    The JDIP Genomics, Proteomics, and Antibodies Core has developed several resources that are available for use by JDIP researchers. Five tasks have been completed or are in progress: Task 1 – Transposon mutants: Nearly 24,000 gene disruption M. paratuberculosis mutants are now available for JDIP re...

  19. SPECT assay of radiolabeled monoclonal antibodies

    International Nuclear Information System (INIS)

    The accurate determination of the biodistribution of radiolabeled monoclonal antibodies (MoAbs) is important for calculation of dosimetry and evaluation of pharmacokinetic variables such as antibody dose and route of administration. The hypothesis of this application is that the biodistribution of radiolabeled monoclonal antibodies (MoAbs) can be quantitatively determined using single photon emission computed tomography (SPECT). The major thrusts during the third year include the continued development and evaluation of improved 3D SPECT acquisition and reconstruction approaches to improve quantitative imaging of radiolabeled monoclonal antibodies (MoAbs), and the implementation and evaluation of algorithms to register serial SPECT image data sets, or to register 3D SPECT images with 3D image data sets acquired from positron emission tomography (PEI) and magnetic resonance images (MRI). The research has involved the investigation of statistical models and iterative reconstruction algorithms that accurately account for the physical characteristics of the SPECT acquisition system. It is our belief that SPECT quantification can be improved by accurately modeling the physical processes such as attenuation, scatter, geometric collimator response, and other factors that affect the measured projection data

  20. Neutralizing antibodies in hepatitis C virus infection

    Institute of Scientific and Technical Information of China (English)

    Mirjam B Zeisel; Samira Fafi-Kremer; Isabel Fofana; Heidi Barth; Fran(c)oise Stoll-Keller; Michel Doffo(e)l; Thomas F Baumert

    2007-01-01

    Hepatitis C virus (HCV) is a major cause of hepatitis world-wide. The majority of infected individuals develop chronic hepatitis which can then progress to liver cirrhosis and hepatocellular carcinoma. Spontaneous viral clearance occurs in about 20%-30% of acutely infected individuals and results in resolution of infection without sequaelae. Both viral and host factors appear to play an important role for resolution of acute infection. A large body of evidence suggests that a strong, multispecific and long-lasting cellular immune response appears to be important for control of viral infection in acute hepatitis C. Due too the lack of convenient neutralization assays,the impact of neutralizing responses for control of viral infection had been less defined. In recent years, the development of robust tissue culture model systems for HCV entry and infection has finally allowed study of antibody-mediated neutralization and to gain further insights into viral targets of host neutralizing responses.In addition, detailed analysis of antibody-mediated neutralization in individual patients as well as cohorts with well defined viral isolates has enabled the study of neutralizing responses in the course of HCV infection and characterization of the impact of neutralizing antibodies for control of viral infection. This review will summarize recent progress in the understanding of the molecular mechanisms of antibody-mediated neutralization and its impact for HCV pathogenesis.(C) 2007 The WJG Press. All rights reserved.

  1. Bone marrow dosimetry for monoclonal antibody therapy

    International Nuclear Information System (INIS)

    Immunoglobulins must permeate through the basement membrane of capillaries in order to enter the extracellular space (ECS) of tissue. Since the process is quite slow, the blood plasma activity in various organs contributes considerably to the radiation dose of the dose-limiting tissues. In bone marrow the basement membrane is absent and the blood circulation is functionally open. Therefore, blood plasma and marrow ECS maintain equal concentrations of labeled immunoglobulins. A combination of factors including intravenous administration, slow absorption into most tissues, slow breakdown and elimination of labeled immunoglobulin, and rapid entry into bone marrow ECS as well as known radiosensitivity of marrow led the authors to expect this tissue would prove to be the primary tissue at risk for systemic monoclonal antibody therapy. They have developed and applied in a Phase I clinical study of 131I labeled CEA antibody a procedure for estimation of radiation dose to red bone marrow. Serieal measurements of blood plasma and total body retention are carried out. Binding of labeled antibody to the cellular components of blood is verified to be very low. They have observed bone marrow depression at doses greater than 400 rad. If no special procedures are used to reconstitute marrow after radiation treatment, this level represents a much greater than generally recognized limitation to radiolabeled monoclonal antibody therapy. 25 references, 4 tables

  2. Antiphospholipid Antibody Syndrome Presenting with Hemichorea

    Directory of Open Access Journals (Sweden)

    Yezenash Ayalew

    2012-01-01

    Full Text Available A 25-year-old Bangladeshi lady presented to neurology with a three-month history of involuntary movements of her right arm, associated with loss of power. There was progression to the right leg, and she subsequently developed episodes of slurred speech and blurred vision. At the time of presentation, she was 12 weeks pregnant and the symptoms were reported to have started at conception. Past medical history was unremarkable apart from one first trimester miscarriage and there was no significant family history suggestive of a hereditary neurological condition. MRI of the head revealed no abnormalities but serology showed positive antinuclear antibodies (ANAs at a titre of 1/400. Further investigations revealed strongly positive anticardiolipin antibodies (>120 and positive lupus anticoagulant antibodies. The patient had a second miscarriage at 19 weeks gestation strengthening the possibility that the chorea was related to antiphospholipid antibody syndrome and she was started on a reducing dose of Prednisolone 40 mg daily and aspirin 300 mg daily. Six months later, she had complete resolution of neurological symptoms. There are several reports of chorea as a feature of antiphospholipid syndrome, but no clear consensus on underlying pathophysiology.

  3. Greasing the SCIDs for Universal Flu Antibodies

    Science.gov (United States)

    Yewdell, Jonathan W.; Ince, William L.

    2013-01-01

    Previews In this issue, Nakamura et al. describe a robust SCID mouse-based method for isolating human monoclonal antibodies of desired specificity from adoptively transferred human B cells. As proof-of principle, they isolate human mAbs that could potentially be used to treat or prevent human infection with any influenza A virus strain. PMID:23870308

  4. Burkholderia pseudomallei Antibodies in Children, Cambodia

    OpenAIRE

    Wuthiekanun, Vanaporn; Pheaktra, Ngoun; Putchhat, Hor; Sin, Lina; Sen, Bun; Kumar, Varun; Langla, Sayan; Peacock, Sharon J.; Nicholas P. Day

    2008-01-01

    Antibodies to Burkholderia pseudomallei were detected in 16% of children in Siem Reap, Cambodia. This organism was isolated from 30% of rice paddies in the surrounding vicinity. Despite the lack of reported indigenous cases, melioidosis is likely to occur in Cambodia.

  5. New Antibody Conjugates in Cancer Therapy

    Directory of Open Access Journals (Sweden)

    Serengulam V. Govindan

    2010-01-01

    Full Text Available Targeting of radiation, drugs, and protein toxins to cancers selectively with monoclonal antibodies (MAbs has been a topic of considerable interest and an area of continued development. Radioimmunotherapy (RAIT of lymphoma using directly labeled MAbs is of current interest after approval of two radiolabeled anti-CD20 MAbs, as illustrated with the near 100% overall response rate obtained in a recent clinical trial using an investigational radiolabeled anti-CD22 MAb, 90Y-epratuzumab. The advantage of pretargeted RAIT over directly labeled MAbs is continuing to be validated in preclinical models of lymphoma and solid tumors. Importantly, the advantages of combining RAIT with radiation sensitizers, with immunotherapy, or a drug conjugate targeting a different antigen are being studied clinically and preclinically. The area of drug-conjugated antibodies is progressing with encouraging data published for the trastuzumab-DM1 conjugate in a phase I clinical trial in HER2-positive breast cancer. The Dock-and-Lock platform technology has contributed to the design and the evaluation of complex antibody-cytokine and antibody-toxin conjugates. This review describes the advances made in these areas, with illustrations taken from advances made in the authors' institutions.

  6. Radiopharmaceuticals based on antibodies and peptides

    International Nuclear Information System (INIS)

    The past two decades have seen a great stride in the development of new diagnostic and therapeutic radiopharmaceuticals due to the discovery and availability of a number of specific carrier molecules and the application of synthetic organic chemistry to modify these carrier molecules to accommodate the radionuclide of interest. Radiopharmaceuticals based on antibodies and peptides are discussed

  7. Antibody Request - Office of Cancer Clinical Proteomics Research

    Science.gov (United States)

    In an effort to provide well-characterized monoclonal antibodies to the scientific community, NCI's Antibody Characterization Program requests cancer-related protein targets for affinity production and distribution.

  8. Distribution of Legionella pneumophila Antibody Among Primate Species

    OpenAIRE

    Helmke, R J; Kalter, S. S.; Heberling, R L

    1981-01-01

    Sera representing 16 different primate species were surveyed by indirect immunofluorescence for evidence of antibody to Legionella pneumophila. The presence of antibody in Old and New World monkeys and in apes supports previous observations of the ubiquity of Legionella pneumophila.

  9. Antibodies Act Jointly to Promote Inflammation in Rheumatoid Arthritis

    Science.gov (United States)

    ... Antibodies Act Jointly to Promote Inflammation in Rheumatoid Arthritis Two types of antibody molecules act in concert to stimulate inflammation in people with rheumatoid arthritis, according to research funded in part by the ...

  10. Experimental investigations with radiolabeled anti-collagen antibody

    International Nuclear Information System (INIS)

    Antibodies to collagen were prepared and labelled with indium 111. Kinetic studies were performed using labelled antibody for up to 48 hours following an injury. These results provide a method to detect injury by radioimmunographic techniques. 5 figs., 3 tabs

  11. Visual Reading of Enzyme Immunofluorescence Assays for Human Cytomegalovirus Antibodies

    OpenAIRE

    Forghani, Bagher; Dennis, Juanita; Schmidt, Nathalie J.

    1980-01-01

    Enzyme immunofluorescence assays for cytomegalovirus antibodies could be read satisfactorily using a light box with ultraviolet illumination. Higher antibody titers were obtained with a fluorogenic substrate than with a color-producing substrate.

  12. Lectin immuno tests: quantitation and titration of antigens and antibodies using lectin-antibody conjugates

    International Nuclear Information System (INIS)

    The authors have investigated the possibility of using lectin-antibody conjugates as general reagents in immunological procedures requiring a labeled antigen or antibody. Using these conjugates, labeling is achieved through saccharide binding sites of lectins which operate as acceptors for glycoconjugate marker substances added secondarily. Marker substances used in this work were enzymes, radioactively labeled glycoconjugates and erythrocytes, but other markers can also be used. Using the first two markers, antigens and antibodies were determined with accuracy and sensitivity equal to those of conventional enzyme or radioimmunoassays. Using erythrocytes as a marker, a simple erythro-adsorption procedure, possibly followed by hemolysis, has been developed which allowed the titration of antigens and antibodies to be carried out with a sensitivity at least equal to enzyme or radioimmunoassays. (Auth.)

  13. B cells contribute to MS pathogenesis through antibody-dependent and antibody-independent mechanisms

    Directory of Open Access Journals (Sweden)

    Wilson HL

    2012-05-01

    Full Text Available Heather L Wilson1,21Vaccine and Infectious Disease Organization-International Vaccine Center, 2Department of Biochemistry, University of Saskatchewan, Saskatoon, Saskatchewan, CanadaAbstract: For many years, central dogma defined multiple sclerosis (MS as a T cell-driven autoimmune disorder; however, over the past decade there has been a burgeoning recognition that B cells contribute to the pathogenesis of certain MS disease subtypes. B cells may contribute to MS pathogenesis through production of autoantibodies (or antibodies directed at foreign bodies, which unfortunately cross-react with self-antigens, through promotion of T cell activation via antigen presentation, or through production of cytokines. This review highlights evidence for antibody-dependent and antibody-independent B cell involvement in MS pathogenesis.Keywords: autoantibodies, antibody targets, clinically isolated MS, primary progressive MS, secondary progressive MS, relapsing and remitting MS, T cells, T regulatory cells

  14. Antibodies to poliovirus detected by immunoradiometric assay with a monoclonal antibody

    Energy Technology Data Exchange (ETDEWEB)

    Spitz, M.; Fossati, C.A.; Schild, G.C.; Spitz, L.; Brasher, M. (National Inst. for Biological Standards and Control, London (UK))

    1982-10-01

    An immunoradiometric assay (IRMA) for the assay of antibodies to poliovirus antigens is described. Dilutions of the test sera or whole (finger prick) blood samples were incubated with the poliovirus antigen bound to a solid phase and the specific antibody was detected by the addition of a mouse anti-human IgG monoclonal antibody (McAb), which was itself revealed by iodinated sheep IgG antimouse F(ab). The authors have shown that this technique is suitable for the estimation of IgG anti-poliovirus antibodies induced in children following polio vaccine. The present study shows that SPRIA provides a simple and inexpensive method for serological studies with poliovirus particularly for use in large-scale surveys.

  15. PRODUCTION OF MONOCLONAL ANTIBODY AGAINST HUMAN IMMUNOGLOBULIN

    Directory of Open Access Journals (Sweden)

    J. Majidi

    2000-04-01

    Full Text Available Immunoglobulin E is one of the five classes of immonoglobulins that plays an important role in allergic diseases. Production of monoclonal antibodies by a single clonotype against different epitopes of immunoglobulin E has high priority in development of diagnostic kits.In this study, an attempt was made to produce monoclonal antibodies against human immunoglobulin E. Balb/c mice were immunized with semipurified immunoglobulin E and spleen cells fused with SP2.0 mouse myeloma eel! line in the presence of polyethylene glycol. Supernatant of hybridoma cells was screened for detection of antibody by enzyme linked immonosorbent assay method. Cloning of selective high absorbance wells were done with limiting dilution method. The suitable clone (monoclone was selected by enzyme linked immunosorbent assay and confirmed by immunoblot. The subclass of the chosen monoclonal antibodies was determined and the clones freezed and kept in liquid nitrogen.During this study three successful fusions were carried out, which resulted in development of 156 clones with high production of anti-IgE. Fourteen clones with the highest titres were selected for cloning. After limiting dilution more than 100 monoclonal antibodies were produced and the suitable (me (GJ0F7, i.e.; the clone which displayed the high absorbance in reaction with purified immunoglobulin E and the lowest cross-reactivity with immunoglobulin M, immunoglobulin G and immoglobulin A was chosen. In immunoblotting, presence of high density band in reaction with immunoglobulin E was confirmed. The suitable mab was shown to be IgG 1 subclass with kappa light chain. It seems that, this mab could be successfully used in diagnostic kits.

  16. The antiphospholipid antibody syndrome: a case report

    Directory of Open Access Journals (Sweden)

    Luma HN

    2012-10-01

    Full Text Available Henry Namme Luma,1,2 Marie-Solange Doualla,1,2 Elvis Temfack,1 Servais Albert Fiacre Eloumou Bagnaka,1 Emmanuella Wankie Mankaa,3 Dobgima Fofung41Department of Internal Medicine, Douala General Hospital, Douala, Cameroon; 2Faculty of Medicine and Biomedical Sciences, University of Yaoundé I, Yaoundé, Cameroon; 3Department of Radiology, Douala General Hospital Douala, Cameroon; 4Department of Abdominal Surgery, Daniel Muna Memorial Clinic, Douala, CameroonAbstract: Antiphospholipid antibody syndrome is defined by the presence of thromboembolic complications and/or pregnancy morbidity in the presence of persistently increased titers of antiphospholipid antibodies. Its clinical presentation can be diverse and any organ can be involved, with a current impact in most surgical and medical specialties. The authors present the case of a 43-year-old man who, over a 13-year period of follow-up, presented with thrombosis of the mesenteric vein, inferior vena cava, and axillary and subclavian veins in a setting where diagnostic and therapeutic options are limited and costly. Through this case report, the authors aim to describe the evolution of this complex pathology, which to date has not been described in the authors' milieu – probably because of its challenging diagnosis and the limited treatment options available. The authors conclude that clinicians need to have a high index of suspicion of APS in patients who present with a thrombotic episode – clinicians should investigate for the presence of antiphospholipid antibodies, as early diagnosis may influence the course of the disease. Furthermore, resources for the detection of antiphospholipid antibodies should be made readily available in resource-limited settings. Finally, patient education on the importance of drug compliance, periodic monitoring, and prevention of thrombosis is indispensable, especially as mortality could be associated with the effects of vascular thrombosis and/or the effects

  17. Nature-inspired design of motif-specific antibody scaffolds

    OpenAIRE

    Koerber, James T.; Thomsen, Nathan D.; Hannigan, Brett T.; DeGrado, William F.; Wells, James A.

    2013-01-01

    Aberrant changes in post-translational modifications (PTMs) such as phosphorylation underlie a majority of human diseases. However, detection and quantification of PTMs for diagnostic or biomarker applications often requires monoclonal PTM-specific antibodies, which are challenging to generate using traditional antibody-generation platforms. Here we outline a general strategy for producing synthetic PTM-specific antibodies by engineering a motif-specific ‘hot spot’ into an antibody scaffold. ...

  18. Anti-Cardiolipin Antibody in Acute Myocardial Infarction

    OpenAIRE

    Abdolreza S. Jahromi; Mohammad Shojaie; Samira Dana; Abdoulhossain Madani

    2010-01-01

    Problem statement: Myocardial infarction is the combined result of environmental and personal factors. Data concerning the relation between anti-Phospholipid (aPL) antibodies and myocardial infarction in subjects without evidence of overt autoimmune disease are conflicting. Anticardiolipin antibody is detected in various diseases like rheumatoid arthritis, systemic lupus erythematosus and anti-phospholipid antibody syndrome. The study of Anticardiolipin antibody in Acute Myocardial Infarction...

  19. ANTI-PHOSPHATIDYLSERINE ANTIBODIES IN ACUTE MYOCARDIAL INFARCTION

    OpenAIRE

    Abdolreza Sotoodeh Jahromi; Mohammad Shojaei; Mohammad Reza Farjam; Abdolhossien Madani

    2013-01-01

    Acute Myocardial Infarction (AMI) is the combined result of environmental factors and personal predispositions. Many factors play a role in AMI including anti-Phospholipid (aPL) antibodies, that may act in the induction of immunological response leading to the development of AMI. Anti-Phosphatidylserine (PS) antibody is detected in various diseases like rheumatoid arthritis, systemic lupus erythematosus and anti-phospholipid antibody syndrome. The study of anti-PS antibody in AMI might shed l...

  20. ANTI DEOXYRIBONUCLEIC ACID AND ANTINUCLEAR ANTIGEN ANTIBODIES IN GRAVES’ DISEASE

    OpenAIRE

    H. Mostafavi

    2005-01-01

    Graves’ disease is an autoimmune disorder characterized by presence of antibodies directed against thyroid stimulating hormone (TSH) receptor or nearby region. Other serological abnormalities like antibodies to double stranded DNA (ds–DNA) and antinuclear antibodies (ANA) have also been observed. We studied antibodies to ds-DNA and ANA in our patients with Graves’ disease and compared them with control group. Sera of 84 patients (29 males, 55 females) with diagnosis of Graves’ disease were pr...