Dalia Nayak

Bio: Dalia Nayak is an academic researcher from Saha Institute of Nuclear Physics. The author has contributed to research in topics: Calcium alginate & Extraction (chemistry). The author has an hindex of 18, co-authored 64 publications receiving 864 citations. Previous affiliations of Dalia Nayak include University of Burdwan.

Biosorption of toxic, heavy, no-carrier-added radionuclides by calcium alginate beads

Abstract: Studies on adsorption behavior of heavy radionuclides, present altogether in no-carrier-added state, e.g., 197-200Pb, 197-200Tl and 197Hg, have been carried out with calcium alginate beads. High lead (100%) and moderate thallium removal (~65%) was achieved in pH range 2-7. 100% mercury removal was also achieved at pH 2 and 4. Effort has been made to recover all three radionuclides adsorbed in the calcium alginate beads using various chemicals, such as HCl, thiourea, sodium acetate, sodium oxalate and sodium nitrite. It was found that 0.1M HCl and 0.1M thiourea could remove at pH 1 80-90% of adsorbed Pb. Tl recovery was possible by all chemicals mentioned above. Hg was also recovered by all chemicals except HCl.

Application of radioisotopes in the field of nuclear medicine: I. Lanthanide series elements

Abstract: A comprehensive review has been made to discuss the role of various radionuclides of lanthanide series elements in the field of nuclear medicine. The role of several pharmaceuticals labeled with radiolanthanides and used for investigative purposes like measurement of cerebral blood flow, bone density measurement, bone marrow imaging, etc., have been described. The role of lanthanide radionuclides in radiation synovectomy, radioimmunotherapy, etc., have also been discussed. Methods of preparation of some representative radiopharmaceuticals like153Sm-EDTMP,153Sm-HYP, have been presented. An outline on the production of carrier free radioisotopes of lanthanide series elements has been given.

Attempts to chemically investigate element 112

Abstract: Two experiments aiming at the chemical investigation of element 112 produced in the heavy ion induced nuclear fusion reaction of 48 Ca with 238 U were performed at the Gesellschaft fur Schwerionenforschung (GSI), Darm-stadt, Germany. Both experiments were designed to determine the adsorption enthalpy of element 112 on a gold surface using a thermochromatography setup. The temperature range covered in the thermochromatography experiments allowed the adsorption of Hg at about 35°C and of Rn at about - 180°C. Reports from the Flerov Laboratory for Nuclear Reactions (FLNR), Dubna, Russia claim production of a 5-min spontaneous fission (SF) activity assigned to 283 112 for the 238 U( 48 Ca,3n) 283 112 reaction. Hence, Experiment I was designed to detect spontaneously fissioning (SF) isotopes of element 112 with half-lives (t 1/2 ) longer than about 20s. 11 high-energy events were detected. 7 events exhibit a deposition pattern resembling a chromatographic peak in the vicinity of Rn deposition. However, the energy of the events observed in Experiment I was lower than expected for a SF-decay of 283 112. Therefore, these events could not be unambiguously attributed to the decay of 283 112. In contradiction with earlier publications newer reports from FLNR Dubna claim that 283 112 decays by α-particle emission (E α =9.5MeV) with t 1/2 = 4 s followed by a SF-decay of 279 Ds (t 1/2 = 0.2 s). Therefore, Experiment II was designed to be sensitive to both claimed decay properties of 283 112. However, during this experiment neither short α-SF correlations nor SF coincidences were detected. The conclusion is that 283 112 was not unambiguously detected, neither in Experiment I nor in Experiment II.

Coordinating Radiometals of Copper, Gallium, Indium, Yttrium and Zirconium for PET and SPECT Imaging of Disease

Abstract: Molecular imaging is the visualization, characterization and measurement of biological processes at the molecular and cellular levels in humans and other living systems. Molecular imaging agents are probes used to visualize, characterize and measure biological processes in living systems. These two definitions were put forth by the Sociey of Nuclear Medicine (SNM) in 2007 as a way to capture the interdisciplinary nature of this relatively new field. The emergence of molecular imaging as a scientific discipline is a result of advances in chemistry, biology, physics and engineering, and the application of imaging probes and technologies has reshaped the philosophy of drug discovery in the pharmaceutical sciences by providing more cost effective ways to evaluate the efficacy of a drug candidate and allowing pharmaceutical companies to reduce the time it takes to introduce new therapeutics to the marketplace. Finally the impact of molecular imaging on clinical medicine has been extensive since it allows a physician to diagnose a patient’s illness, prescribe treatment and monitor the efficacy of that treatment non-invasively. Single Photon Emission Computed Tomography (SPECT) and Positron Emission Tomography (PET) were the first molecular imaging modalities used clinically. SPECT requires the use of a contrast agent labeled with a gamma emitting radionuclide, which should have an ideal gamma energy of 100-250 keV. These gamma rays are recorded by the detectors of a dedicated gamma camera or SPECT instrument and after signal processing can be converted into an image indentifying the localization of the radiotracer. PET requires the injected radiopharmaceutical to be labeled with a positron emitting radionuclide. As the radionuclide decays it ejects a positron from its nucleus which travels a short distance before being annihilated with an electron to release two 511 keV gamma rays 180° apart that are detected by the PET scanner (Figure 1). After sufficient acquisition time the data are reconstructed using computer based algorithms to yield images of the radiotracer’s location within the organism. When compared to SPECT, PET has greater advantages with respect to sensitivity and resolution and has been gaining in clinical popularity, with the number of PET-based studies expected to reach 3.2 million by 2010.1 While SPECT and PET technology has been around for decades, its use remained limited because of the limited availability of relevant isotopes which had to be produced in nuclear reactors or particle accelerators. However, the introduction of the small biomedical cyclotron, the self-contained radionuclide generator and the dedicated small animal or clinical SPECT and PET scanners to hospitals and research facilities has increased the demand for SPECT and PET isotopes. Figure 1 Cartoon depicting the fundamental principle of Positron Emission Tomography (PET). As the targeting group interacts with the cell surface receptor, the positron emitting radio-metal decays by ejecting β+ particles from its nucleus. After traveling ... Traditional PET isotopes such as 18F, 15O, 13N and 11C have been developed for incorporation into small molecules, but due to their often lengthy radio-syntheses, short half-lives and rapid clearance, only early time points were available for imaging, leaving the investigation of biological processes, which occur over the duration of hours or days, difficult to explore. With the continuing development of biological targeting agents such as proteins, peptides, antibodies and nanoparticles, which demonstrate a range of biological half-lives, a need arose to produce new radionuclides with half-lives complementary with their biological properties. As a result, the production and radiochemistry of radiometals such as Zr, Y, In, Ga and Cu have been investigated as radionuclide labels for biomolecules since they have the potential to combine their favorable decay characteristics with the biological characteristics of the targeting molecule to become a useful radiopharmaceutical (Tables ​(Tables11 and ​and22).2 Table 1 Gamma- and Beta-Emitting Radiometals Table 2 Positron-Emitting Radiometals The number of papers published describing the production or use of these radiometals continues to expand rapidly, and in recognition of this fact, the authors have attempted to present a comprehensive review of this literature as it relates to the production, ligand development and radiopharmaceutical applications of radiometals (excluding 99mTc) since 1999. While numerous reviews have appeared describing certain aspects of the production, coordination chemistry or application of these radiometals,2-18 very few exhaustive reviews have been published.10,12 Additionally, this review has been written to be used as an individual resource or as a companion resource to the review written by Anderson and Welch in 1999.12 Together, they provide a literature survey spanning 50 years of scientific discovery. To accomplish this goal, this review has been organized into three sections: the first section discusses the coordination chemistry of the metal ions Zr, Y, In, Ga and Cu and their chelators in the context of radiopharmaceutical development; the second section describes the methods used to produce Zr, Y, In, Ga and Cu radioisotopes; and the final section describes the application of these radiometals in diagnostic imaging and radiotherapy.

Heaviest nuclei from 48Ca-induced reactions

Abstract: After a brief introduction of the role of shell effects in determining the limiting nuclear masses, the experimental investigation of the decay properties of the heaviest nuclei is presented. For the production of superheavy nuclides fusion, reactions of heavy actinide nuclei with 48Ca-projectiles have been used. The properties of the new nuclei, the isotopes of elements 112–118, as well as of their decay products, together with the known data for the light isotopes with Z ≤ 113, give evidence of the significant increase of the stability with the neutron number of the heavy nucleus. The obtained results are discussed in the context of the theoretical predictions about the 'island of stability' of the hypothetical superheavy elements.

Separation of high field strength elements (Nb, Ta, Zr, Hf) and Lu from rock samples for MC‐ICPMS measurements

Abstract: [1] The application of multiple collector inductively coupled plasma source mass spectrometry (MC-ICPMS) to 176Lu-176Hf and 92Nb-92Zr chronometry has been hampered by complex Zr-Hf purification procedures that involve multiple ion exchange column steps. This study presents a single-column separation procedure for purification of Hf and Lu by ion exchange using Eichrom® Ln-Spec resin. The sample is loaded in pure HCl, and element yields are not dependent on the sample matrix. For 92Nb-92Zr chronometry, a one-column procedure for purification of Zr using Biorad® AG-1-× 8 resin is described. Titanium and Mo are completely removed from the Zr, thus enabling accurate 92Zr measurements. Zirconium and Nb are quantitatively separated from rock samples using Eichrom Ln-Spec resin, allowing measurements of Zr/Nb with a precision of better than ±5% (2σ). The Ln-Spec and anion resin procedures may be combined into a three-column method for separation of Zr-Nb, Hf, Ta, and Lu from rock samples. For the first time, this procedure permits combined isotope dilution measurements of Nb/Ta, Zr/Hf, and Lu/Hf using a mixed 94Zr-176Lu-180Hf-180Ta tracer. Analytical protocols for Zr and Hf isotope measurements using the Micromass Isoprobe, a second generation, single-focusing MC-ICPMS, are reported. Using the Isoprobe at Munster, 2σ external precisions of ±0.5ɛ units for Hf and Zr isotope measurements are achieved using as little as 5 ng (Hf) to 10 ng (Zr) of the element. The 176Hf/177Hf and Lu/Hf for rock reference materials agree well with other published MC-ICPMS and thermal ionization mass spectrometry (TIMS) data.

Cosmogenic nuclides : principles, concepts and applications in the earth surface sciences

Abstract: This is the first book to provide a comprehensive and state-of-the-art introduction to the novel and fast-evolving topic of in-situ produced cosmogenic nuclides. It presents an accessible introduction to the theoretical foundations, with explanations of relevant concepts starting at a basic level and building in sophistication. It incorporates, and draws on, methodological discussions and advances achieved within the international CRONUS (Cosmic-Ray Produced Nuclide Systematics) networks. Practical aspects such as sampling, analytical methods and data-interpretation are discussed in detail and an essential sampling checklist is provided. The full range of cosmogenic isotopes is covered and a wide spectrum of in-situ applications are described and illustrated with specific and generic examples of exposure dating, burial dating, erosion and uplift rates, and process model verification. Graduate students and experienced practitioners will find this book a vital source of information on the background concepts and practical applications in geomorphology, geography, soil-science, and geology.