Can we predict reactivity for aromatic nucleophilic substitution with [ 18 F]fluoride ion?

The correlation between the 13 C‐NMR chemical shift of the aromatic ring carbon bearing the leaving group and the yield of nucleophilic aromatic displacement with no‐carrier‐added [ 18 F]fluoride ion was evaluated. In comparison of structurally analogous compounds (fluoro, nitro and trimethylammonium substituted benzaldehydes, benzophenones and benzonitriles), the 13 C‐NMR chemical shift of the reactive aryl ring carbon correlated quite well with the [ 18 F]fluorination yield (r 2 =0.87) for most but not all ring structures. Compounds with trimethylammonium leaving groups or methyl ring substituents were found to not fit the proposed correlation. Kinetic studies indicated clearly different rates of reaction for these compounds, with much higher than expected reactivity for the ccompounds with the cationic leaving group. Competition experiments suggest that low reactivity of methyl‐substituted rings may be due to conversion of [ 18 F]fluoride to an unreactive form. Our results indicate that the correlation between [ 18 F]fluorination yields for nucleophilic aromatic substitution reactions and the 13 C NMR chemical shift of the aryl ring carbon bearing the leaving group is applicable to numerous structurally analogous compounds, but cannot be simply generalized to aromatic rings with different leaving groups or ring substituents.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90183/1/2580330702_ftp.pd

A gas-jet system for the study of short-lived, light fission products

For the study of short-lived fission products, a gas jet system has been set up in a beam port of the Ford Nuclear Reactor at the University of Michigan. The system consists of a target chamber joined to three polyethylene tubes which serve as gas inlet, fission product outlet and an outlet for pressure monitoring. The target chamber is housed in a 7.6 cm (ID) aluminum tube supported inside a radial beam port. This tube can be withdrawn by ∼1 m, allowing the target chamber to be positioned either close to or ∼1 m from the core. The aluminum tube is surrounded by water, which provides shielding and protects the target when not in use (at ∼1 m position). The target is ∼1 mg of 235 U, chemically plated on an aluminum planchett. The uranium is covered with 2.7 mg·cm −2 of aluminum. The aluminum covering stops most of the heavy fission fragments; the light fission fragments pass through the foil and are thermalized in a gaseous mixture of nitrogen and ethylene. The transport time of fission products from the target chamber to the detector position was measured to be 970 msec. Preliminary experiments indicate that the transport time can be reduced further. The gas jet system is being utilized for the development of fast, gas-phase chemistry for the separation of bromine from fission products.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43134/1/10967_2005_Article_BF02037088.pd

Public education on sources and effects of radioactive waste disposal

A six-day workshop, developed for providing information on sources and effects of radioactive waste disposal to the general public, is described. The materials were used successfully with a group representing the general public. An extension of the workshop for high school and junior high school science teachers is discussed. *** DIRECT SUPPORT *** A0653119 00009Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43117/1/10967_2005_Article_BF02039694.pd

Characterizing a source of fission fragments for a gas jet

A model for the rate at which various primary fission products stop in the gas of the source chamber of a gas jet has been constructed. It describes the absorption of fission fragments in Al foils placed between the 235 U deposit and the gas chamber as well as the penetration of fragments through the gas. The model is based on reported ranges (mean values as a function of A and the dispersion in ranges) and measured activities of Kr and Xe.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43112/1/10967_2005_Article_BF02060552.pd

Empiric Radiotherapy for Lung Cancer Collaborative Group multi-institutional evidence-based guidelines for the use of empiric stereotactic body radiation therapy for non-small cell lung cancer without pathologic confirmation

The standard of care for managing early stage non-small cell lung cancer (NSCLC) is definitive surgical resection. Stereotactic body radiation therapy (SBRT) has become the standard treatment for patient who are medically inoperable, and it is increasingly being considered as an option in operable patients. With the growing use of screening thoracic CT scans for patients with a history of heavy smoking, as well as improved imaging capabilities, the discovery of small lung nodes has become a common dilemma. As a result, clinicians are increasingly faced with managing lung nodules in patients in whom diagnostic biopsy is not safe or feasible. Herein, we describe the scope of the problem, tools available for predicting the probability that a lung nodule is a malignancy, staging procedures, benefits of pathology-proven and empiric SBRT, considerations of safety based on location of the lesion of concern, and overall efficacy of SBRT

INFECTION PREVENTION AND CONTROL AWARENESS, ATTITUDES, AND PRACTICES AMONG HEALTHCARE PROFESSIONALS IN SOUTH INDIA

Introduction: Infection is a key challenge in healthcare settings around the world. Healthcare professionals (HCPs), including medical laboratory technologists (MLTs) and nurses, are at risk of infection because they are in close contact with infected patients. This investigation was conducted to evaluate the awareness, attitude, and practices of Infection Prevention Control (IPC) among HCPs working in private tertiary hospitals in two states in South India. Methodology: This quantitative study surveyed 571 HCPs in southern India. In September 2021, an online survey was used to collect data on the respondents’ demographic and IPC-related variables, as well as their awareness, attitudes, and practices of IPC. Results: The survey revealed high level of awareness, positive attitudes, and good IPC practices. Among the IPC practices, “changing gloves between contacts with different patients” was the most often practiced and “washing hands after removal of gloves” was the least practiced. Being a nurse, being older, finishing a graduate program, attending a risk assessment training, having sufficient Personal Protective Equipment (PPE) at work, and being aware of the safety guidelines were associated with better awareness. Being a nurse, being older, and holding a diploma were associated with more positive attitudes. Being MLT, attending risk assessment training, having sufficient PPE at work, and being aware of the safety guidelines were associated with better IPC practices. Conclusions: Measures to sustain the high awareness, positive attitudes, and good IPC practices by dealing with the factors associated with these variables identified in this study must be planned and implemented

Endoplasmic reticulum stress and cell death in mTORC1-overactive cells is induced by nelfinavir and enhanced by chloroquine

Inappropriate activation of mammalian/mechanistic target of rapamycin complex 1 (mTORC1) is common in cancer and has many cellular consequences including elevated endoplasmic reticulum (ER) stress. Cells employ autophagy as a critical compensatory survival mechanism during ER stress. This study utilised drug-induced ER stress through nelfinavir in order to examine ER stress tolerance in cell lines with hyper-active mTORC1 signalling. Our initial findings in wild type cells showed nelfinavir inhibited mTORC1 signalling and upregulated autophagy, as determined by decreased rpS6 and S6K1 phosphorylation, and SQTSM1 protein expression, respectively. Contrastingly, cells with hyper-active mTORC1 displayed basally elevated levels of ER stress which was greatly exaggerated following nelfinavir treatment, seen through increased CHOP mRNA and XBP1 splicing. To further enhance the effects of nelfinavir, we introduced chloroquine as an autophagy inhibitor. Combination of nelfinavir and chloroquine significantly increased ER stress and caused selective cell death in multiple cell line models with hyper-active mTORC1, whilst control cells with normalised mTORC1 signalling tolerated treatment. By comparing chloroquine to other autophagy inhibitors, we uncovered that selective toxicity invoked by chloroquine was independent of autophagy inhibition yet entrapment of chloroquine to acidified lysosomal/endosomal compartments was necessary for cytotoxicity. Our research demonstrates that combination of nelfinavir and chloroquine has therapeutic potential for treatment of mTORC1-driven tumours

Quantification of sodium present in dry aggregates and anodes

In aluminum industry, it is important to determine the concentration of contaminants present in anode raw materials as rapidly as possible in order to adjust the anode recipe. Sodium, which is an impurity coming largely from anode butts, significantly influences the anode reactivity, and an increase in its concentration increases the anode consumption. A simple and inexpensive method was developed to quantify the sodium content in dry aggregates and anodes without grinding the samples. The method is based on potentiometric principles using a sodium-ion specific electrode. A sample can be analyzed easily within thirty minutes. In order to prevent the rapid degradation of the specific electrode due to experimental conditions, sodium is extracted from samples by electrophoresis prior to the test. The comparison shows that the measured sodium concentrations obtained are similar to the results determined by other test methods