Nuclear medicine technologists practice impacted by AI denoising applications in PET/CT images.

PURPOSE: Artificial intelligence (AI) in positron emission tomography/computed tomography (PET/CT) can be used to improve image quality when it is useful to reduce the injected activity or the acquisition time. Particular attention must be paid to ensure that users adopt this technological innovation when outcomes can be improved by its use. The aim of this study was to identify the aspects that need to be analysed and discussed to implement an AI denoising PET/CT algorithm in clinical practice, based on the representations of Nuclear Medicine Technologists (NMT) from Western-Switzerland, highlighting the barriers and facilitators associated. METHODS: Two focus groups were organised in June and September 2023, involving ten voluntary participants recruited from all types of medical imaging departments, forming a diverse sample of NMT. The interview guide followed the first stage of the revised model of Ottawa of Research Use. A content analysis was performed following the three-stage approach described by Wanlin. Ethics cleared the study. RESULTS: Clinical practice, workload, knowledge and resources were de 4 themes identified as necessary to be thought before implementing an AI denoising PET/CT algorithm by ten NMT participants (aged 31-60), not familiar with this AI tool. The main barriers to implement this algorithm included workflow challenges, resistance from professionals and lack of education; while the main facilitators were explanations and the availability of support to ask questions such as a "local champion". CONCLUSION: To implement a denoising algorithm in PET/CT, several aspects of clinical practice need to be thought to reduce the barriers to its implementation such as the procedures, the workload and the available resources. Participants emphasised also the importance of clear explanations, education, and support for successful implementation. IMPLICATIONS FOR PRACTICE: To facilitate the implementation of AI tools in clinical practice, it is important to identify the barriers and propose strategies that can mitigate it.

Double layer SiO2-TiO2 sol-gel thin films on glass for antireflection, antifogging, and UV recoverable self-cleaning.

Double layer thin films, mechanically stable and adhering to glass, were produced through the sol-gel process, using tetraethyl orthosilicate and titanium butoxide as precursors. The refractive index of the titania and silica-titania composite layers were typically 2.1 and 1.7, and their physical thicknesses were approximately 65 nm and 81 nm, respectively, as determined by ellipsometry. These optical constants allowed attainment of quarter-wave optical thicknesses at the center of the visible spectrum (550 nm) as designed, with an increase of 3.4% in transmittance. The nanometric surface roughness, measured by optical profilometry, was effective to decrease light scattering and water contact angles to below 10°. As novelty in dip-coated sol-gel films, superhydrophilicity for self-cleaning, antifogging, and antireflection in the mid-visible spectrum were simultaneously attained with durability of 9 weeks in the dark. Further application of UV light allowed regeneration of contact angles for self-cleaning.

Predicting enteric methane production from cattle in the tropics.

Accurate estimates of methane (CH4) production by cattle in different contexts are essential to developing mitigation strategies in different regions. We aimed to: (i) compile a database of CH4 emissions from Brazilian cattle studies, (ii) evaluate prediction precision and accuracy of extant proposed equations for cattle and (iii) develop specialized equations for predicting CH4 emissions from cattle in tropical conditions. Data of nutrient intake, diet composition and CH4 emissions were compiled from in vivo studies using open-circuit respiratory chambers, SF6 technique or the GreenFeed® system. A final dataset containing intake, diet composition, digestibility and CH4 emissions (677 individual animal observations, 40 treatment means) obtained from 38 studies conducted in Brazil was used. The dataset was divided into three groups: all animals (GEN), lactating dairy cows (LAC) and growing cattle and non-lactating dairy cows (GCNL). A total of 54 prediction equations available in the literature were evaluated. A total of 96 multiple linear models were developed for predicting CH4 production (MJ/day). The predictor variables were DM intake (DMI), gross energy (GE) intake, BW, DMI as proportion of BW, NDF concentration, ether extract (EE) concentration, dietary proportion of concentrate and GE digestibility. Model selection criteria were significance (P < 0.05) and variance inflation factor lower than three for all predictors. Each model performance was evaluated by leave-one-out cross-validation. The Intergovernmental Panel on Climate Change (2006) Tier 2 method performed better for GEN and GCNL than LAC and overpredicted CH4 production for all datasets. Increasing complexity of the newly developed models resulted in greater performance. The GCNL had a greater number of equations with expanded possibilities to correct for diet characteristics such as EE and NDF concentrations and dietary proportion of concentrate. For the LAC dataset, equations based on intake and animal characteristics were developed. The equations developed in the present study can be useful for accurate and precise estimation of CH4 emissions from cattle in tropical conditions. These equations could improve accuracy of greenhouse gas inventories for tropical countries. The results provide a better understanding of the dietary and animal characteristics that influence the production of enteric CH4 in tropical production systems.

Control of osmotic pressure to improve cell viability in cell-laden tissue engineering constructs.

Design of tissue engineering strategies deals with the need to balance both biomaterials characteristics and techniques specificities, often resulting in cell-compromising processing conditions. One important factor often disregarded is the osmotic pressure to which cells are exposed. An in-house microfluidic system was used to prove that addition of an osmotic regulator significantly benefits the generation of viable cell-laden hydrogels under harsh processing conditions. Human adipose-derived stem cells were resuspended in 1.5% alginate and 1% gellan gum (GG; w/v) solutions containing different concentrations (0.12 m, 0.25 m and 1.5 m) of sucrose as osmotic regulator. GG (in water) and alginate (in water or phosphate-buffered saline) solutions were used to vary the conditions under which cells were kept prior processing. Independently of the polymer, addition of sucrose did not affect the processing conditions or the viscosity of the solutions, except at 1.5 m. The obtained results clearly demonstrate that inclusion of 0.25 m sucrose during processing of the cell-laden hydrogels allowed to keep cell viability around 80%, in opposition to the 20% observed in its absence, both for GG and alginate-derived hydrogels prepared in water. Impressively, the level of cell viability observed with the inclusion of 0.25 m sucrose, 76% for GG and 86% for alginate, was similar to that obtained with the standard alginate solution prepared in phosphate-buffered saline (82%). The beneficial effect of sucrose was observed within the first 5 min of processing and was maintained for prolonged experimental setups with viability values above 50%, even after a 2-h time-frame and independently of the material.

Clinical and epidemiological characteristics of injuries caused by venomous snakes observed at the Hospital for Tropical Diseases of Araguaína, Tocantins State, Brazil, from 1995 to 2000

Injuries caused by venomous snakes are considered a problem of public health in Brazil, and further studies for a better knowledge are very important. The aim of this work is to describe clinical and epidemiological characteristics that were observed from 1995 to 2000 in the Hospital for Tropical Diseases of Araguaína, Tocantins State, Brazil, which is a unit of health that takes care of patients suffering from tropical diseases. We studied 440 individuals and the most common characteristics observed were masculine sex, age among 15-45 years, bite in low members, and injuries caused by snakes of the Bothrops genus. The signs and symptoms more frequently observed were edema, pain, erythema, and bleeding. The most observed systemic manifestation was alteration of blood coagulation. The most frequent complications were abscess, necrosis, bacterial infection, and renal failure. The mortality rate was 3%. These data are very important for the evaluation of the problem

Leishmaniasis in Brazil. XXI. Visceral leishmaniasis in the Amazon Region and further observations on the role of Lutzomyia longipalpis (Lutz & Neiva, 1912) as the vector.

Further evidence is presented incriminating the sandfly Lutzomyia longipalpis as the vector of Leishmania chagasi, the causative agent of American visceral leishmaniasis, in the Amazon Region of Brazil. During an outbreak of the disease in Santarém, Pará State, this insect was shown to be the only species of sandfly consistently present in and around the patient's homes, where it often occurred in very large numbers. Of 491 specimens dissected, 35 (7.14%) proved to be infected, and isolates of L. chagasi were made from 16 of 27 of these sandflies following the inoculation of the promastigotes into hamsters. Finally, the parasite was transmitted to four other hamsters which had been subjected to the bites of large numbers of wild-caught Lu. longipalpis. Isolates of Leishmania from Lu. longipalpis captures in Santarém, and in another focus of visceral leishmaniasis on the Island of Marajó, Pará, have been shown to be biologically and biochemically indistinguishable from the parasite infecting man, dogs and foxes in Pará, and from stocks obtained from man elsewhere in Brazil (Bahia and Ceará States).

Leishmaniose cutanea na Amazonia. Registro do primeiro caso humano de infeccao mista, determinado por duas especies distintas de leishmanias: Leishmania brasiliensis e Leishmania mexicana amazonensis. / Cutaneous leishmania in Amazonia. Report of the 1st human case of mixed infection determined by 2 different Leishmania species: Leishmania brasiliensis and Leishmania mexicana amazonensis

Fez-se o registro, na Amazonia, do primeiro caso humano de infeccao cutanea mista determinada por duas especies distintas de Leishmania: a Leishmania brasiliensis e a Leishmania mexicana amazonensis. As duas amostras, em questao foram isoladas de lesoes distintas de um mesmo paciente, e a caracterizacao das especies foi feita com base em observacao de infeccao experimentalem Lutzomya lingipalpis, e eletroforese de isoenzimas em gel de amido. Conclui-se ser de interesse o achado que, combirando com o fato ja conhecido de ausencia de imunidade cruzada entre a maioria das leishmanias, sugere a necessidade do emprego de uma vacina polivalente para a regiao