Technetium Isotopes Research Articles

Research of Potential Production 94mTc in Medical Cyclotron

To expand the spectrum of used radiopharmaceuticals, it is proposed to obtain a positron-emitting isotope of technetium 94mTc. The intention of this work is to research the possibility of producing various technetium isotopes on a medical cyclotron. For this purpose, we carried out a series of irradiations of an aqueous solution of molybdenum of natural isotopic composition with protons of 11 MeV energy. After technetium isolation, results were analyzed on a γ-spectrometer. 511 keV gamma-ray line was obtained.

Determinants of successful ictal SPECT injection in phase 1 epilepsy presurgical evaluation: Findings from the pediatric epilepsy research consortium surgery database project.

The main goal of presurgical evaluation in drug-resistant focal epilepsy is to identify a seizure onset zone (SOZ). Of the noninvasive, yet resource-intensive tests available, ictal single-photon emission computed tomography (SPECT) aids SOZ localization by measuring focal increases in blood flow within the SOZ via intravenous peri-ictal radionuclide administration. Recent studies indicate that geographic and center-specific factors impact utilization of these diagnostic procedures. Our study analyzed successful ictal SPECT acquisition (defined as peri-ictal injection during inpatient admission) using surgery-related data from the Pediatric Epilepsy Research Consortium (PERC) surgery database. We hypothesized that a high seizure burden, longer duration of video EEG monitoring (VEEG), and more center-specific hours of SPECT availability would increase the likelihood of successful ictal SPECT. We identified study participants (≤18 years of age) who underwent SPECT as part of their phase 1 VEEG from January 2018 to June 2022. We assessed association between ictal SPECT outcomes (success vs. failure) and variables including patient demographics, epilepsy history, and center-specific SPECT practices. Phase 1 VEEG monitoring with ictal SPECT injection was planned in 297 participants and successful in 255 participants (85.86%). On multivariable analysis, the likelihood of a successful SPECT injection was higher in patients of non-Hispanic ethnicity (p = 0.040), shorter duration VEEG (p = 0.004), and higher hours of available SPECT services (p < 0.001). Higher seizure frequency (p = 0.033) was significant only in bivariate analysis. Patients treated at centers with more operational hours were more likely to experience pre-admission protocols prior to VEEG (p = 0.002). There is inter-center variability in protocols and SPECT acquisition capabilities. Shorter duration of EEG monitoring, non-Hispanic ethnicity (when on private insurance), extended operational hours of nuclear medicine as noted on multivariate analysis and higher seizure frequency in bivariate analysis are strongly associated with successful ictal SPECT injection. In pediatric patients with drug-resistant epilepsy, single-photon emission computed tomography (SPECT) scans can be helpful in localizing seizure onset zone. However, due to many logistical challenges described below, which include not only the half-life of the technetium isotope used to inject intravenously during a seizure (called the ictal SPECT scan) but also available nuclear scanner time in addition to the unpredictability of seizures, obtaining an ictal SPECT during a planned elective inpatient hospital stay is not guaranteed. Thus, as healthcare costs increase, planning a prolonged hospital stay during which an ictal SPECT scan is not feasible is not optimal. We leveraged our prospective surgery database to look at center-specific factors and patient-specific factors associated with an ictal SPECT injection in the first, pediatric-focussed, large-scale, multicenter, prospective, SPECT feasibility study. We found that longer availability of the scanner is the most important center-specific factor in assuring ictal SPECT injection. Although seizure frequency is an important patient-specific factor on bivariate analysis, this factor lost statistical significance when other factors like patient insurance status and video EEG duration were also considered in our multivariable logistical model.

ANALYSIS OF THE PRODUCTION OF RARE-EARTH ISOTOPES AT THE WWR-K RESEARCH REACTOR: PROMISING THERAPEUTIC RADIONUCLIDES

Rare Earth Elements (REE) are a group of seventeen chemical elements in the periodic table, including lanthanides and scandium and yttrium. These elements have unique physical and chemical properties that make them valuable in various industries, including electronics, magnets, and catalysts. However, radioactive isotopes of rare earth elements also possess effective nuclear physical properties that make them promising for the development of new radiopharmaceuticals for therapeutic purposes. These radioactive isotopes have unstable atoms with excess nuclear energy, and they undergo radioactive decay, which can be utilized for medical applications.The nuclear physical properties of radioactive isotopes of rare earth elements make them suitable for therapeutic purposes in medicine. For example, technetium-99m, a radioactive isotope of technetium, is widely used in diagnostic nuclear medicine due to its outstanding physical-chemical characteristics. Other radioactive isotopes of rare earth elements, such as holmium-166, have been established for a broad spectrum of medical applications. These isotopes can be used in targeted radiation therapy to treat various diseases, including cancer. The unique properties of these radioactive isotopes allow for precise targeting and delivery of radiation to specific tissues or cells, minimizing damage to healthy tissues.The potential of radioactive isotopes of rare earth elements for therapeutic purposes extends beyond the current applications. Ongoing research and innovations in the field of radiopharmaceuticals continue to explore the use of underutilized lanthanoid radionuclides for theranostic purposes. For example, astatine, a rare and highly radioactive element, exhibits multiple isotopes that can be potentially utilized in targeted therapy. The development of new radiopharmaceuticals using radioactive isotopes of rare earth elements holds promise for advancing medical treatments and improving patient outcomes. With further research and advancements, these isotopes may play a crucial role in the future of therapeutic medicine.This research work makes it possible to evaluate the possibility of obtaining REE such radioisotopes as: 90Y, 141Ce, 147Nd, 153Sm, 165Dy, 166Ho, 169Tm, 175Yb, 177Yb, 177Lu by reaction (n, γ) at the WWR-K reactor.

INFLUENCE OF COPPER COMPLEXES [CU(PTA)4]BF4 AND [СU(ACAC)2] ON RATS IRRADIATED WITH RADIOISOTOPE TECHNETIUM

One of the priority tasks of modern radiobiology is the search for new, effective radioprotective compounds. In this area, metal complexes with high antioxidant activity are of particular interest. In order to study the possible favorable radioprotective effect of two copper complexes in different oxidation states, [Cu(PTA)4]BF4 and [Сu(acac)2], on the irradiated organism, we studied cytogenetic parameters in 4 groups of experimental animals. Group I included intact animals; Group II consisted of animals exposed to technetium (Tc) radioisotope, which were intraperitoneally injected with an isotope with an activity of 4.8 mCi in a volume of 2 mL - "pure irradiation"; Group III consisted of animals that were intraperitoneally injected with the copper(I) complex [Cu(PTA)4]BF4 at a dose of 50 mg/kg in a volume of 2 mL one hour before the administration of the Tc isotope (“irradiation + [Cu(PTA)4]BF4”). Group IV included animals that received the copper(II) complex [Сu(acac)2] before irradiation. We studied survival and cytogenetic parameters, determined the mitotic index, chromosomal aberrations and the percentage of polyploid cells. The survival rate of group II was 40%. In the group of intact animals, as well as in groups III and IV the survival rate was 100%. The dynamics of survival was described by regression equations, which make it possible, by means of extrapolation, to determine the change in the percentage of survival in the long term of the experiment and to predict the further outcome of the experiment. Investigating cytogenetic indicators, for all 3 indicators, a significant difference was found between intact and irradiated animals, i.e. these indicators can be considered as markers of technetium isotope exposure. In terms of proliferative activity, a significant difference was found in irradiated animals compared with groups III and IV, which indicates the radioprotective property of both the copper compounds. As for the [Cu(acac)2], when it was used in group IV and compared with others, we obtained a pronounced significant difference from the group with “pure irradiation” in all studied cytogenetic parameters. It was found that the copper complexes [Cu(PTA)4]BF4 and [Cu(acac)2] have the ability to prevent or mitigate the effect of ionizing radiation on an animal's body. Based on cytogenetic parameters, it can be concluded that these compounds promote reparative processes in the bone marrow cells of irradiated animals. Multiregression analysis of cytogenetic parameters confirmed the highest efficiency of the copper (II) complex [Cu(acac)2]. The results of the research indicate the need to continue work in the direction of searching for agents that have a therapeutic effect in radiation injuries.

Studying and simulation of clean area for Tc 99m production in Radioisotope Production Facility

Clean areas nowadays are advanced technology solutions with very high standard and criteria applied on air quality level. Egyptian Radioisotopes Production facility (RPF) is a facility that requires clean area to produce technetium (Tc99m) isotope for medical purposes. The air cleanliness inside area is dependent on the air quality of supplied air, contaminant and pollutant sources, dedicated ventilation system in addition to rigorous precautions to sterilize space of the area and commitment to follow standard recommendations. Two main standard classes are available in production area, A and C according to ISO 14644-1. Our paper deals with class C in which isotope is produced and some tests are conducted to know particle counts in that area in addition to prediction of these counts by computer simulation Contam-CFD0 program, which predicts transient particles count behavior which compared with standard WHO values and measurements for validation. Biological tests are also implemented to monitor sterility of area to confirm cleanliness and validity for processing medical radioisotope. High efficiency particulate air filters with class H14 are dedicated for the clean area and equipped with pressure drop manometer for replacement in case of blockage. Simulation program is also used to predict particles concentration in case of filter contamination.

Tc-rich M stars: platypuses of low-mass star evolution

AbstractThe technetium-rich (Tc-rich) M stars reported in the literature (Little-Marenin &amp; Little 1979; Uttenthaler et al. 2013) are puzzling objects since no isotope of technetium has a half-life longer than a few million years, and 9999Tc, the longest-lived isotope along the s-process path, is expected to be detected only in thermally-pulsing stars enriched with other s-process elements (like zirconium). Carbon should also be enriched, since it is dredged up at the same time, after each thermal pulse on the asymptotic giant branch (AGB). However, these Tc-enriched objects are classified as M stars, meaning that they neither have any significant zirconium enhancement (otherwise they would be tagged as S-type stars) nor any large carbon overabundance (in which case they would be carbon stars).Here we present the first detailed chemical analysis of a Tc-rich M-type star, namely S Her. We first confirm the detection of the Tc lines, and then analyze its carbon and s-process abundances, and draw conclusions on its evolutionary status. Understanding these Tc-rich M stars is an important step to constrain the threshold luminosity for the first occurrence of the third dredge-up and the composition of s-process ejecta during the very first thermal pulses on the AGB.

105Tc nuclear structure and systematic evolution of states of 1/2+[431] intruder band in odd-A 95,97,99,101,103,105,107Tc isotopes

Previously observed negative and positive parity states of 105Tc were studied in the framework of the particle-rotor model. Transition properties and experimental energies were compared to the predictions of model calculations. A systematic study of the evolution of the intruder π1/2+[413] band in the nuclear structure of odd-A technetium isotopes 95,97,99,101,103,105,107Tc is presented as well. The existence of this intruder band has been argued previously in 95,97,99,101,103Tc isotopes (partially populated) and fully observed and confirmed in 105Tc. It will be shown that changes in deformation and subsequently the position of the Fermi level, vis a vis the 1/2+[431] intruder orbital originating from the π(d5/2, g7/2) subshells, predominantly affect these systematic changes. All four interpreted experimental rotational bands are naturally predicted by the rotational model as bands build on states of good Ω originating from the 5/2+[422], 5/2–[303], 3/2–[301], and 1/2+[431] orbitals near the Fermi level in deformed 105Tc (strong coupling). Further experimental investigation about missing data are needed for those observed in low lying states in both 105Tc and 103Tc to confirm the presence of the 1/2–[301] rotational band that is well defined in lighter 95,97,99,101Tc isotopes.

Radioisotopic purity and imaging properties of cyclotron-produced 99mTc using direct 100Mo(p,2n) reaction

Evaluation of the radioisotopic purity of technetium-99m (99mTc) produced in GBq amounts by proton bombardment of enriched molibdenum-100 (100Mo) metallic targets at low proton energies (i.e. within 15–20 MeV) is conducted. This energy range was chosen since it is easily achievable by many conventional medical cyclotrons already available in the nuclear medicine departments of hospitals. The main motivation for such a study is in the framework of the research activities at the international level that have been conducted over the last few years to develop alternative production routes for the most widespread radioisotope used in medical imaging. The analysis of technetium isotopes and isomeric states (9xTc) present in the pertechnetate saline Na99mTcO4 solutions, obtained after the extraction/purification procedure, reveals radionuclidic purity levels basically in compliance with the limits recently issued by European Pharmacopoeia 9.3 (2018 Sodium pertechnetate (99mTc) injection 4801–3). Moreover, the impact of 9xTc contaminant nuclides on the final image quality is thoroughly evaluated, analyzing the emitted high-energy gamma rays and their influence on the image quality. The spatial resolution of images from cyclotron-produced 99mTc acquired with a mini-gamma camera was determined and compared with that obtained using technetium-99m solutions eluted from standard 99Mo/99mTc generators. The effect of the increased image background contribution due to Compton-scattered higher-energy gamma rays (Eγ > 200 keV), which could cause image-contrast deterioration, was also studied. It is concluded that, due to the high radionuclidic purity of cyclotron-produced 99mTc using 100Mo(p,2n)99mTc reaction at a proton beam energy in the range 15.7–19.4 MeV, the resulting image properties are well comparable with those from the generator-eluted 99mTc.

Nosocomial transmission of hepatitis C virus in a liver transplant center in Hong Kong: implication of reusable blood collection tube holder as the vehicle for transmission.

A liver transplant recipient developed hospital-acquired symptomatic hepatitis C virus (HCV) genotype 6a infection 14 months post transplant. Standard outbreak investigation. Patient chart review, interviews of patients and staff, observational study of patient care practices, environmental surveillance, blood collection simulation experiments, and phylogenetic study of HCV strains using partial envelope gene sequences (E1-E2) of HCV genotype 6a strains from the suspected source patient, the environment, and the index patient were performed. Investigations and data review revealed no further cases of HCV genotype 6a infection in the transplant unit. However, a suspected source with a high HCV load was identified. HCV genotype 6a was found in a contaminated reusable blood-collection tube holder with barely visible blood and was identified as the only shared item posing risk of transmission to the index case patient. Also, 14 episodes of sequential blood collection from the source patient and the index case patient were noted on the computerized time log of the laboratory barcoding system during their 13 days of cohospitalization in the liver transplant ward. Disinfection of the tube holders was not performed after use between patients. Blood collection simulation experiments showed that HCV and technetium isotope contaminating the tip of the sleeve capping the sleeved-needle can reflux back from the vacuum-specimen tube side to the patient side. A reusable blood-collection tube holder without disinfection between patients can cause a nosocomial HCV infection. Single-use disposable tube holders should be used according to the recommendations by Occupational Safety and Health Administration and World Health Organization.

Rhenium and technetium complexes of thioamide derivatives of pyridylhydrazine that bind to amyloid-β plaques.

Age-associated deposition of amyloid-β in cerebral blood vessels, a condition referred to as cerebral amyloid angiopathy, can contribute to stroke and dementia. This research aimed to design new radioactive technetium-99m complexes that bind to amyloid-β plaques that have the potential to assist in diagnosis of cerebral amyloid angiopathy using single-photon-emitted computed tomography (SPECT) imaging. Six new pyridylthiosemicarbazide ligands containing either benzofuran or styrylpyridyl functional groups that are known to selectively bind to amyloid plaques were prepared. Non-radioactive isotopes of technetium are not available so rhenium was used as a surrogate for exploratory chemistry. The new ligands were used to prepare well-defined [Re-oxo]3+ complexes where two pyridylthiosemicarbazide ligands were coordinated to a single metal ion to give bivalent complexes with two amyloid-β targeting functional groups. The interaction of the [Re-oxo]3+ complexes with synthetic amyloid-β1-42 and with amyloid plaques in human brain tissue was investigated. Two ligands were selected to develop methods to prepare their [99mTc-oxo]3+ complexes at the tracer level. These technetium-99m complexes are likely to be isostructural to their rhenium-oxo analogues.

Chemically stable ionic viologen-organic network: an efficient scavenger of toxic oxo-anions from water.

Detoxification of water has been demonstrated with a viologen-based cationic organic network (compound-1), which was stable not only in water, but also in acidic and basic media. The presence of free exchangeable Cl- ions inside the network of compound-1 and a high physiochemical stability of the materials offered a suitable scope for the capture of hazardous anionic pollutants from water. Rapid removal of the toxic water pollutant and carcinogenic chromate (CrO4 2-) from water was shown with compound-1. Furthermore, the oxo-anion of the radioactive isotope of technetium (99Tc), i.e. the TcO4 - ion, also counts as a toxic water pollutant and by using surrogate anions (MnO4 - and ReO4 -), a model capture study was performed. Notably, compound-1 showed high capacity values for each of the oxo-anions and these were comparable to some of the well-performing compounds reported in the literature. Furthermore, to check the real time aspect, removal of all of the aforementioned anions from water was demonstrated, even in the presence of other concurrent anions.

Rhenium and Technetium-oxo Complexes with Thioamide Derivatives of Pyridylhydrazine Bifunctional Chelators Conjugated to the Tumour Targeting Peptides Octreotate and Cyclic-RGDfK.

This research aimed to develop new tumor targeted theranostic agents taking advantage of the similarities in coordination chemistry between technetium and rhenium. A γ-emitting radioactive isotope of technetium is commonly used in diagnostic imaging, and there are two β– emitting radioactive isotopes of rhenium that have the potential to be of use in radiotherapy. Variants of the 6-hydrazinonicotinamide (HYNIC) bifunctional ligands have been prepared by appending thioamide functional groups to 6-hydrazinonicotinamide to form pyridylthiosemicarbazide ligands (SHYNIC). The new bidentate ligands were conjugated to the tumor targeting peptides Tyr3-octreotate and cyclic-RGD. The new ligands and conjugates were used to prepare well-defined {M=O}3+ complexes (where M = 99mTc or natRe or 188Re) that feature two targeting peptides attached to the single metal ion. These new SHYNIC ligands are capable of forming well-defined rhenium and technetium complexes and offer the possibility of using the 99mTc imaging and 188/186Re therapeutic matched pairs.

Technetium: The First Radioelement on the Periodic Table

The radioactive nature of technetium is discussed using a combination of introductory nuclear physics concepts and empirical trends observed in the chart of the nuclides and the periodic table of the elements. Trends such as the enhanced stability of nucleon pairs, magic numbers, and Mattauch’s rule are described. The concepts of nuclear binding energies and the nuclear shell model are introduced and used to explain the relative stability of radionuclides and, in particular, the isotopes of technetium.

Impaired gallbladder function in patients after total gastrectomy

Background and aims: The incidence of gallstones and gallbladder sludge is higher in patients after total gastrectomy than in general population. Formation of gallstones after gastrectomy is multifactorial. Here, we investigate the changes in gallbladder and biliary tract functions by cholescintygraphy and monitored changes in cholecystokinin (CCK) release in long-term survivors after total gastrectomy for gastric carcinoma.Material and methods: Patients had undergone total gastrectomy for gastric carcinoma at least five years ago. The final study population consisted of 25 patients.Results: Eight patients had undergone cholecystectomy before or at the time of gastrectomy. Gallstone formation was observed in seven of the remaining 17 patients during follow-up (41%). Maximum uptake of radioactivity and gallbladder maximum uptake was significantly delayed in the gastrectomy group than in the control group. There was no significant difference in CCK levels after the overnight fasting and at 60 minutes after stimulation among patients with or without stones in situ compared with healthy volunteers, but 30 minutes after the energy-rich drink patients had higher CCK levels than the control group.Conclusions: In gastrectomy patients, technetium isotope visualisation of the gallbladder and time for maximum activity was significantly delayed. This may indicate impaired gallbladder function. On the contrary, CCK release was not impaired.

Imaging study of using radiopharmaceuticals labeled with cyclotron-produced 99mTc

Cyclotron-produced 99mTc (CPTc) has been recognized as an attractive and practical substitution of reactor/generator based 99mTc. However, the small amount of 92-98Mo in the irradiation of enriched 100Mo could lead to the production of other radioactive technetium isotopes (Tc-impurities) which cannot be chemically separated. Thus, these impurities could contribute to patient dose and affect image quality. The potential radiation dose caused by these Tc-impurities produced using different targets, irradiation conditions, and corresponding to different injection times have been investigated, leading us to create dose-based limits of these parameters for producing clinically acceptable CPTc. However, image quality has been not considered.The aim of the present work is to provide a comprehensive and quantitative analysis of image quality for CPTc. The impact of Tc-impurities in CPTc on image resolution, background noise, and contrast is investigated by performing both Monte-Carlo simulations and phantom experiments. Various targets, irradiation, and acquisition conditions are employed for investigating the image-based limits of CPTc production parameters. Additionally, the relationship between patient dose and image quality of CPTc samples is studied. Only those samples which meet both dose- and image-based limits should be accepted in future clinical studies.

Synthesis of Oxorhenium(V) and Oxotechnetium(V) Complexes That Bind to Amyloid-β Plaques.

Alzheimer's disease is characterized by the presence of amyloid plaques in the brain. The primary constituents of the plaques are aggregated forms of the amyloid-β (Aβ) peptide. With the goal of preparing technetium-99(m) complexes that bind to Aβ plaques with the potential to be diagnostic imaging agents for Alzheimer's disease, new tetradentate ligands capable of forming neutral and lipophilic complexes with oxotechentium(V) and oxorhenium(V) were prepared. Nonradioactive isotopes of technetium are not available so rhenium was used as a surrogate for exploratory chemistry. Two planar tetradentate N3O ligands were prepared that form charge-neutral complexes with oxorhenium(v) as well as a ligand featuring a styrylpyridyl functional group designed to bind to Aβ plaques. All three ligands formed complexes with oxorhenium(V), and each complex was characterized by NMR spectroscopy, mass spectrometry, and X-ray crystallography. The oxorhenium(V) complex with a styrylpyridyl functional group binds to Aβ plaques present in post-mortem human brain tissue. The chemistry was extrapolated to technetium-99(m) at the tracer level for two of the ligands. The resulting oxotechnetium(V) complexes were sufficiently lipophilic and charge-neutral to suggest that they have the potential to cross the blood-brain barrier but exhibited modest stability with respect to exchange with histidine. The chemistry presented here identifies a strategy to integrate styrylpyridyl functional groups into tetradentate ligands capable of forming complexes with [M═O](3+) cores (M = Re or Tc).

Technique and outcome of autotransplanting thyroid tissue after total thyroidectomy for simple multinodular goiters

Limited animal and human studies have shown function, albeit inadequate, of implanted thyroid tissue in muscles. This work aimed to ascertain results in a larger number of patients, finding practical method for implantation, studying the effect of changing weight of implant and effect of passage of time on its function. Forty patients had total thyroidectomy for simple multinodular goiters. A piece of the excised gland was finely minced, mixed with saline as emulsion, and injected in thigh muscles. Twelve patients had 5-g implants, while 28 patients had 10-g implants. Four parameters were studied at 2 months, 6 months, and 12 months: technetium isotope uptake by the implant; thyroid stimulating hormone (TSH); free T3 (FT3); and free T4 (FT4). All autotransplanted thyroid tissue survived and functioned. After 12 months, mean values (± standard deviation) of isotope uptake, TSH, FT3, and FT4 of the 5-g implants were 0.44±0.16%, 27.74±30.4UI/mL, 3.07±1.10 pg/mL, and 1.01±0.3ng/dL, repectively. Those for the 10g implants were 0.71±0.20%, 22.78±19.7UI/mL, 3.92±1.2pg/mL, and 1.05±0.3ng/dL, repectively. Ten-gram implants showed significantly higher isotope uptake than 5-g. TSH, FT3, and FT4 significantly improved over the period of 1 year. Injection of thyroid tissue suspension is a simple method for thyroid autotransplantation. TSH was elevated in the majority to maintain normal or near normal thyroid hormones. Ten-gram implants showed higher isotope uptake than 5-g, although this difference was not reflected by thyroid hormone profile. The implant seemed to function better with the passage of time from 2 months to 12 months.

First identification of rotational band structures inRe9175166

Despite that it is more than 100 years since the atomic nucleus was first dis- covered by Ernest Rutherford and coworkers, many of its features still elude our understanding. The fact that the fundamental interactions between the nuclear constituents; nucleons, and ultimately quarks, are not yet known in detail, and the complexity of the nuclear many-body system compound the great challenges facing theoretical interpretations of experimental data. It is therefore important to focus on distinct phenomena where experimental mea- surements can be compared with theoretical predictions, providing stringent tests of theory. One such area is the nuclear phenomenology of collective excitations related to rotations and vibrations of the nucleus as a whole, and how such modes of excitation may develop from the interactions between a few nucleons occupying single-particle orbits outside closed shells.This thesis is devoted to experimental studies of excited states in the 99Tc, 162W, and 166Re nuclei. These nuclei lie in “transitional” regions of the Segre chart, where collective excitation mechanisms start becoming important when adding valence nucleons outside closed neutron and proton shells. Such nuclei are important for testing state-of-the-art theoretical models. The excited states of the nuclei studied in the present work were populated using heavy-ion fusion-evaporation reactions. Prior to the present work, high-spin data were still lacking in 99Tc since in the previous works [1–5] excited states were only populated up to around 3 MeV. Two collective bands have been extended to intermediate angular momentum states in the present work. The experimental results were compared with the systematics of other technetium isotopes, evaluating electromagnetic characteristics based on semiclassical calculations and the particle-rotor model. The 162W and 166Re nuclei are situated in the very neutron-deficient 160-170 mass region, requiring special techniques for identifying their excited-state structures. The level scheme of 162W was first reported by Dracoulis et al. in 1993 [6], where the first excited 2+ state was assigned to be 450 keV above the ground state. However, the lack of selectivity made the γ-ray identification for higher energy levels of 162W uncertain. In this work, the highly selective recoil-decay tagging technique was used to uniquely identify γ-ray transitions from excited states in 162W and to construct its level scheme. In addition, the experimental setup enabled a precise determination of the half-life of the α-decaying ground state of 162W. The α-formation probability for 162W was extracted from the measurement of the half-life and systematical comparisons with the neighboring nuclei were performed. Two rotational-like bands were identified in 166Re for the first time and the lifetimes of the lowest three excited states in band (1) were measured using the recoil distance Doppler shift method. The results were compared with theoretical calculations based on a semiclassical approach, the particle-rotor model, and the tilted axis cranking model in a relativistic mean field approach. The microscopic mechanisms (configuration and alignment, etc) of the rotational bands were interpreted under the framework of total Routhian surface predictions and cranked shell model calculations.

Production of 95mTc for Compton camera imaging

With the development of the Compton camera which can realize high position resolution, technetium isotopes emitting high energy gamma-rays are required. In this study, Technetium-95m which emits some gamma rays with higher than 200 keV was produced by the 95Mo(p,n)95mTc reaction. Image of gamma-rays from 95mTc was taken by a Compton gamma-ray camera.

Leakage from closed-system transfer devices as detected by a radioactive tracer

A study of leakage from selected closed-system transfer devices (CSTDs) under experimental conditions is described. Three CSTDs (the ChemoClave, OnGuard, and PhaSeal systems) were tested. Nine manufacturer-trained oncology pharmacists and pharmacy technicians volunteered to participate in an experiment to determine the degree of leakage of a liquid test agent (a radioactive technetium isotope [(99m)Tc] diluted in normal saline) during CSTD-assisted transfer of liquid from vials to syringes per standard practices. After such transfers, alcohol prep pads (n = 135 for each system) were used to wipe CSTD points of entry and assessed for the presence of (99m)Tc. Comparisons among participants and devices were conducted via analysis of variance (ANOVA), with the a priori level of significance set at 0.05. ANOVA results indicated significant differences among devices in leakage of the test solution, with the PhaSeal device having the lowest geometric mean leakage (0.1 nL; 95% confidence interval [CI], 0-0.2 nL), followed by the OnGuard (1.5 nL; 95% CI, 1.1-1.9 nL) and ChemoClave (35.6 nL; 95% CI, 29.1-43.6 nL) devices; each pairwise comparison was significant (p < 0.001). Despite several major limitations, the research supports the use of CSTDs to help protect health care workers, as recommended by federal authorities and professional groups including the American Society of Health-System Pharmacists. The volume of leakage was significantly less with PhaSeal than with OnGuard and ChemoClave when pharmacists and pharmacy technicians used the three CSTDs and (99m)Tc as a tracer.