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The investigation of hydrogen in atom probe tomography appears as a relevant challenge due to its low mass, high diffusion coefficient, and presence as a residual gas in vacuum chambers, resulting in multiple complications for atom probe studies. Different solutions were proposed in the literature like ex situ charging coupled with cryotransfer or H charging at high temperature in a separate chamber. Nevertheless, these solutions often faced challenges due to the complex control of specimen temperature during hydrogen charging and subsequent analysis. In this paper, we propose an alternative route for in situ H charging in atom probe derived from a method developed in field ion microscopy. By applying negative voltage nanosecond pulse on the specimen in an atom probe chamber under a low pressure of H2, it is demonstrated that a high dose of H can be implanted in the range 2-20 nm beneath the specimen surface. An atom probe chamber was modified to enable direct negative pulse application with controlled gas pressure, pulse repetition rate, and pulse amplitude. Through electrodynamical simulations, we show that the implantation energy falls within the range 100-1,000 eV and a theoretical depth of implantation was predicted and compared to experiments., Competing Interests: Conflict of Interest: The authors declare that they have no competing interest., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Microscopy Society of America. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

A position and energy-sensitive detector has been developed for atom probe tomography (APT) instruments in order to deal with some mass peak overlap issues encountered in APT experiments. Through this new type of detector, quantitative and qualitative improvements could be considered for critical materials with mass peak overlaps, such as nitrogen and silicon in TiSiN systems, or titanium and carbon in cemented carbide materials. This new detector is based on a thin carbon foil positioned on the front panel of a conventional MCP-DLD detector. According to several studies, it has been demonstrated that the impact of ions on thin carbon foils has the effect of generating a number of transmitted and reflected secondary electrons. The number generated mainly depends on both the kinetic energy and the mass of incident particles. Despite the fact that this phenomenon is well known and has been widely discussed for decades, no studies have been performed to date for using it as a means to discriminate particles energy. Therefore, this study introduces the first experiments on a potential new generation of APT detectors that would be able to resolve mass peak overlaps through the energy-sensitivity of thin carbon foils.

There is strong, and growing, evidence documenting health inequities across the world. However, most governments do not prioritize policies to encourage action on the social determinants of health and health equity. Furthermore, despite evidence concerning the benefits of joined-up, intersectoral policy to promote health and health equity, it is rare for such policy approaches to be applied systematically. To examine the usefulness of political and social science theory in understanding the reasons for this disjuncture between evidence and practice, researchers and public servants gathered in Adelaide for an Academy of the Social Sciences in Australia (ASSA) Workshop. This paper draws together the learnings that emerged from the Workshop, including key messages about the usefulness of various theories as well as insights drawn from policy practice. Discussions during the Workshop highlighted that applying multiple theories is particularly helpful in directing attention to, and understanding, the influence of all stages of the policy process; from the construction and framing of policy problems, to the implementation of policy and evaluation of outcomes, including those outcomes that may be unintended. In addition, the Workshop emphasized the value of collaborations among public health researchers, political and social scientists and public servants to open up critical discussion about the intersections between theory, research evidence and practice. Such critique is vital to render visible the processes through which particular sources of knowledge may be privileged over others and to examine how political and bureaucratic environments shape policy proposals and implementation action., (© The Author(s) 2018. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Due to the low capacity of contemporary position-sensitive detectors in atom probe tomography (APT) to detect multiple events, material analyses that exhibit high numbers of multiple events are the most subject to compositional biases. To solve this limitation, some researchers have developed statistical correction algorithms. However, those algorithms are only efficient when one is confronted with homogeneous materials having nearly the same evaporation field between elements. Therefore, dealing with more complex materials must be accompanied by a better understanding of the signal loss mechanism during APT experiments. By modeling the evaporation mechanism and the whole APT detection system, it may be possible to predict compositional and spatial biases induced by the detection system. This paper introduces a systematic study of the impact of the APT detection system on material analysis through the development of a simulation tool.

The occurrence of malignant lymphoma is an increasingly important cause of morbidity and mortality in AIDS patients. The incidence of AIDS-related lymphoma in some developing countries such as Brazil is increasing as the survival of HIV infection has improved. Although there is a clear association between several types of immunodeficiency-related lymphomas and Epstein-Barr virus (EBV), the association of EBV infection in AIDS-related lymphoma in Brazil, where the incidence of AIDS is high, is unknown. Formalin-fixed, paraffin-embedded tissue from 24 cases of AIDS-related lymphoma in Brazil were analyzed for morphologic classification, immunophenotype, and EBV association using in situ hybridization studies with an EBV-EBER1 biotinylated probe. Twenty cases of AIDS-related lymphoma were classified as non-Hodgkin's lymphoma and four cases were Hodgkin's disease. Eleven non-Hodgkin's lymphomas were classified as diffuse large cell type, five cases were small non-cleaved cell, Burkitt-type, and four cases were large cell immunoblastic non-Hodgkin's lymphoma. Eighteen cases were of B-cell phenotype; one was a T-cell lymphoma, and one was classified as null. Epstein-Barr virus (EBV) was demonstrated in the majority of tumor cells of 11 of 20 (55%) of the cases non-Hodgkin's lymphomas and in 3 of 4 (75%) cases of Hodgkin's disease. AIDS-related lymphomas in Brazil are usually of large cell/immunoblastic type, but Hodgkin's disease is also seen. Both non-Hodgkin's lymphoma and Hodgkin's disease are often associated with EBV infection. The non-Hodgkin's lymphoma is predominantly of B-cell phenotype.

The authors report the histories of two patients with undifferentiated carcinoma metastatic to lymph nodes simulating the "syncytial variant" of nodular sclerosing Hodgkin's disease. One of the patients initially was treated for Hodgkin's disease, but the clinical evolution was more typical of carcinoma. Both lesions were characterized histologically by noncohesive aggregates of large neoplastic cells with abundant eosinophilic cytoplasm and conspicuous nucleoli. Although cells compatible with diagnostic Reed-Sternberg cells were identified in an "appropriate" cellular background in both patients, the diagnosis of carcinoma was supported by intense cytokeratin immunoreactivity. Subtle histologic clues that should suggest the possibility of metastatic carcinoma in a patient whose morphologic data suggests the syncytial variant of nodular sclerosing Hodgkin's disease include sinus infiltration, phagocytosis of neutrophils by tumor cells, marked nuclear anaplasia, and the presence of spindle-shaped tumor cells.

HMB45 is a melanoma-specific monoclonal antibody that has found widespread use in diagnostic pathology. Recent reports, however, have suggested that this antibody may cross-react with a small number of carcinomas and other epithelial cells. The authors tested the hypothesis that these latter reports represent examples of false-positive immunostaining by comparing the immunostaining on breast, salivary gland, and lung tumors with the following: (1) a commercial ascites preparation of this monoclonal antibody; (2) a protein A-purified antibody preparation derived from ascites fluid; and (3) supernatant fluid obtained from the hybridoma cell line. The authors found that all examples of nonmelanoma immunostaining in the carcinomas tested were eliminated with the nonascites fluid preparations, whereas strong immunostaining of melanomas was retained. The authors conclude that contaminated commercial ascites fluid preparations of HMB45 may account for most, if not all, of the reports of nonmelanoma immunostaining with HMB45.

The antitumour antibiotic bleomycin, supplied as commercial BlenoxaneR (a mixture of bleomycinic acids), at 7 or 14 mg/kg prolonged life greater than 30 days beyond death of controls without relapse or sign of trypanosomes in the peripheral blood of mice infected with Trypanosoma b. brucei EATRO 110. Control mice died in three to four days. The purified A2 and B2 bleomycin congeners were also active at this dose. Spermidine, spermine and hirudonine (1,8-diamidinospermidine) but not putrescine, co-administered with drug, annulled the curative effects of these compounds, as signalled by appearance of trypanosomes in the blood and death of the animals.