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1.
Nature ; 604(7907): 635-642, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35478233

RESUMO

The prosperity and lifestyle of our society are very much governed by achievements in condensed matter physics, chemistry and materials science, because new products for sectors such as energy, the environment, health, mobility and information technology (IT) rely largely on improved or even new materials. Examples include solid-state lighting, touchscreens, batteries, implants, drug delivery and many more. The enormous amount of research data produced every day in these fields represents a gold mine of the twenty-first century. This gold mine is, however, of little value if these data are not comprehensively characterized and made available. How can we refine this feedstock; that is, turn data into knowledge and value? For this, a FAIR (findable, accessible, interoperable and reusable) data infrastructure is a must. Only then can data be readily shared and explored using data analytics and artificial intelligence (AI) methods. Making data 'findable and AI ready' (a forward-looking interpretation of the acronym) will change the way in which science is carried out today. In this Perspective, we discuss how we can prepare to make this happen for the field of materials science.


Assuntos
Inteligência Artificial , Ciência de Dados
2.
PLoS Comput Biol ; 20(8): e1012331, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39141681

RESUMO

Surprise is a key component of many learning experiences, and yet its precise computational role, and how it changes with age, remain debated. One major challenge is that surprise often occurs jointly with other variables, such as uncertainty and outcome probability. To assess how humans learn from surprising events, and whether aging affects this process, we studied choices while participants learned from bandits with either Gaussian or bi-modal outcome distributions, which decoupled outcome probability, uncertainty, and surprise. A total of 102 participants (51 older, aged 50-73; 51 younger, 19-30 years) chose between three bandits, one of which had a bimodal outcome distribution. Behavioral analyses showed that both age-groups learned the average of the bimodal bandit less well. A trial-by-trial analysis indicated that participants performed choice reversals immediately following large absolute prediction errors, consistent with heightened sensitivity to surprise. This effect was stronger in older adults. Computational models indicated that learning rates in younger as well as older adults were influenced by surprise, rather than uncertainty, but also suggested large interindividual variability in the process underlying learning in our task. Our work bridges between behavioral economics research that has focused on how outcomes with low probability affect choice in older adults, and reinforcement learning work that has investigated age differences in the effects of uncertainty and suggests that older adults overly adapt to surprising events, even when accounting for probability and uncertainty effects.


Assuntos
Envelhecimento , Reforço Psicológico , Humanos , Idoso , Adulto , Pessoa de Meia-Idade , Masculino , Adulto Jovem , Feminino , Envelhecimento/fisiologia , Envelhecimento/psicologia , Incerteza , Comportamento de Escolha/fisiologia , Biologia Computacional , Aprendizagem/fisiologia
3.
Phys Chem Chem Phys ; 2024 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-39291341

RESUMO

This study explores how laser light affects the morphology of tetracene films, and it presents novel strategies for improving the creation of thin films used in (opto-)electronic devices. We demonstrate that laser light (532 nm, 1.1 W mm-2), applied during tetracene deposition, not only increases grain size but also induces photoalignment. The observed effects arise from enhanced molecular diffusion, resulting from energy transferred by light to the molecules after adsorption, but not from heating the substrate surface underneath. We observe that linearly polarized light promotes photoalignment, while increased crystallite sizes occurs with both linear and circular polarizations. We propose an Ostwald ripening process facilitated by laser illumination, where smaller crystallites get optically heated and dissolve, allowing molecules to surmount step-edge barriers and assemble into larger crystallites. Importantly, the crystallite sizes achieved with laser illumination surpass those attainable by substrate heating alone. The study demonstrates that laser illumination acts as a promising new parameter for controlling thin film properties and is distinct from growth control via substrate temperature and growth rate. Light control also includes the ability for lateral patterning, with implications for the future of molecular materials and their manufacturing technologies.

4.
Arch Toxicol ; 2024 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-39261308

RESUMO

Man-made vitreous fibers (MMVF) comprise diverse materials for thermal and acoustic insulation, including stone wool. Depending on dimension, durability, and dose, MMVF might induce adverse health effects. Therefore, early predictive in vitro (geno)toxicity screening of new MMVF is highly desired to ensure safety for exposed workers and consumers. Here, we investigated, as a starting point, critical in vitro screening determinants and pitfalls using primary rat alveolar macrophages (AM) and normal rat mesothelial cells (NRM2). A stone wool fiber (RIF56008) served as an exemplary MMVF (fibrous vs. ground to estimate impact of fiber shape) and long amosite (asbestos) as insoluble fiber reference. Materials were comprehensively characterized, and in vivo-relevant in vitro concentrations defined, based on different approaches (low to supposed overload: 0.5, 5 and 50 µg/cm2). After 4-48 h of incubation, certain readouts were analyzed and material uptake was investigated by light and fluorescence-coupled darkfield microscopy. DNA-strand break induction was not morphology-dependent and nearly absent in both cell types. However, NRM2 demonstrated material-, morphology- and concentration-dependent membrane damage, CINC-1 release, reduction in cell count, and induction of binucleated cells (asbestos > RIF56008 > RIF56008 ground). In contrast to NRM2, asbestos was nearly inactive in AM, with CINC-1 release solely induced by RIF56008. In conclusion, to define an MMVF-adapted, predictive in vitro (geno)toxicity screening tool, references, endpoints, and concentrations should be carefully chosen, based on in vivo relevance, and sensitivity and specificity of the chosen cell model. Next, further endpoints should be evaluated, ideally with validation by in vivo data regarding their predictivity.

5.
Nano Lett ; 23(13): 5975-5980, 2023 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-37341711

RESUMO

Phonon scattering at grain boundaries (GBs) is significant in controlling the nanoscale device thermal conductivity. However, GBs could also act as waveguides for selected modes. To measure localized GB phonon modes, milli-electron volt (meV) energy resolution is needed with subnanometer spatial resolution. Using monochromated electron energy loss spectroscopy (EELS) in the scanning transmission electron microscope (STEM) we have mapped the 60 meV optic mode across GBs in silicon at atomic resolution and compared it to calculated phonon densities of states (DOS). The intensity is strongly reduced at GBs characterized by the presence of 5- and 7-fold rings where bond angles differ from the bulk. The excellent agreement between theory and experiment strongly supports the existence of localized phonon modes and thus of GBs acting as waveguides.

6.
Nano Lett ; 23(3): 1068-1076, 2023 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-36637381

RESUMO

The integration of metallic contacts with two-dimensional (2D) semiconductors is routinely required for the fabrication of nanoscale devices. However, nanometer-scale variations in the 2D/metal interface can drastically alter the local optoelectronic properties. Here, we map local excitonic changes of the 2D semiconductor MoS2 in contact with Au. We utilize a suspended and epitaxially grown 2D/metal platform that allows correlated electron energy-loss spectroscopy (EELS) and angle resolved photoelectron spectroscopy (nanoARPES) mapping. Spatial localization of MoS2 excitons uncovers an additional EELS peak related to the MoS2/Au interface. NanoARPES measurements indicate that Au-S hybridization decreases substantially with distance from the 2D/metal interface, suggesting that the observed EELS peak arises due to dielectric screening of the excitonic Coulomb interaction. Our results suggest that increasing the van der Waals distance could optimize excitonic spectra of mixed-dimensional 2D/3D interfaces and highlight opportunities for Coulomb engineering of exciton energies by the local dielectric environment or moiré engineering.

7.
Neuroimage ; 273: 120099, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37037380

RESUMO

Aging is associated with changes in spatial navigation behavior. In addition to an overall performance decline, older adults tend to rely more on proximal location cue information than on environmental boundary information during spatial navigation compared to young adults. The fact that older adults are more susceptible to errors during spatial navigation might be partly attributed to deficient dopaminergic modulation of hippocampal and striatal functioning. Hence, elevating dopamine levels might differentially modulate spatial navigation and memory performance in young and older adults. In this work, we administered levodopa (L-DOPA) in a double-blind within-subject, placebo-controlled design and recorded functional neuroimaging while young and older adults performed a 3D spatial navigation task in which boundary geometry or the position of a location cue were systematically manipulated. An age by intervention interaction on the neural level revealed an upregulation of brain responses in older adults and a downregulation of responses in young adults within the medial temporal lobe (including hippocampus and parahippocampus) and brainstem, during memory retrieval. Behaviorally, L-DOPA had no effect on older adults' overall memory performance; however, older adults whose spatial memory improved under L-DOPA also showed a shift towards more boundary processing under L-DOPA. In young adults, L-DOPA induced a decline in spatial memory performance in task-naïve participants. These results are consistent with the inverted-U-shaped hypothesis of dopamine signaling and cognitive function and suggest that increasing dopamine availability improves hippocampus-dependent place learning in some older adults.


Assuntos
Dopamina , Navegação Espacial , Idoso , Humanos , Adulto Jovem , Hipocampo/fisiologia , Levodopa/farmacologia , Memória Espacial/fisiologia , Navegação Espacial/fisiologia , Lobo Temporal/diagnóstico por imagem , Lobo Temporal/fisiologia , Método Duplo-Cego
8.
J Water Health ; 21(7): 884-894, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37515560

RESUMO

Legionella concentrations in drinking water have been regulated for decades and are evaluated with regard to their concentrations in drinking water plumbing systems (DWPS). The respective action levels differ at the international level. In Germany, the Federal Environment Agency (UBA) specifies the application of ISO 11731 for the detection of legionella in drinking water and gives a binding recommendation for the methods to be used for culturing and evaluation. Effective from 01 March 2019, the UBA recommendation was revised. The utilized culture media in the culture approach were altered, consequently affecting the spectrum of legionella colonies detected in drinking water. Using data from a routine legionella monitoring of a large laboratory, over a period of 6 years and 17,270 individual drinking water samples, allowed us to assess the impact of the alteration on the assessment of DWPS. By comparing the amount of action level exceedances before and after the method change, it could be demonstrated that exceedances are reported significantly more often under the new method. Consequently, the corresponding action level for evaluation of legionella contamination and the resulting risk to human health needs to be revised to avoid the misleading impression of increased health risk.


Assuntos
Água Potável , Legionella pneumophila , Legionella , Humanos , Água Potável/análise , Microbiologia da Água , Engenharia Sanitária , Alemanha , Abastecimento de Água
9.
Vet Surg ; 52(7): 994-1008, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37496312

RESUMO

OBJECTIVE: To develop a minimally invasive technique for placing a toggle construct across the coxofemoral joint of small equids using computer-assisted surgery. STUDY DESIGN: Experimental cadaveric study. SAMPLE POPULATION: Three pilot specimens: One donkey, one Shetland pony and one Warmblood foal. Six main study specimens: Three Shetland ponies, one American Miniature Horse, one Warmblood foal and one donkey. METHODS: Experimental surgeries were performed on both coxofemoral joints of each cadaver. Using a minimally invasive surgical approach, 5.5 mm bone canals were drilled through the femur and acetabulum, traversing the coxofemoral joint. Intraoperative guidance was provided by a cone-beam computed tomography (CBCT)-coupled surgical navigation system. A toggle construct was introduced through the bone canals. Surgical accuracy aberrations (SAA) were measured at the femoral entry and exit points and at the acetabular entry point on merged pre- and postoperative CBCT scans. The coxofemoral joint was assessed for articular cartilage damage by gross dissection. RESULTS: A toggle construct was placed across all 18 coxofemoral joints. The overall median SAA in the main study was 2.8 mm (range: 0.4-8.0 mm). No cartilage damage was found in the cadaveric specimens of the main study. CONCLUSION: The described technique allowed for the placement of a toggle construct across the coxofemoral joint of small equid cadaveric specimens without prior coxofemoral luxation. CLINICAL RELEVANCE: This technique may serve as an option for surgical stabilization of coxofemoral joints in small equids. Further biomechanical investigations are required to assess optimal implant positioning and toggle constructs.


Assuntos
Doenças dos Cavalos , Cirurgia Assistida por Computador , Animais , Cavalos/cirurgia , Estudo de Prova de Conceito , Articulação do Quadril/cirurgia , Cirurgia Assistida por Computador/veterinária , Equidae , Cadáver
10.
Neuroimage ; 264: 119670, 2022 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-36243268

RESUMO

Previous studies indicate a role of dopamine in spatial navigation. Although neural representations of direction are an important aspect of spatial cognition, it is not well understood whether dopamine directly affects these representations, or only impacts other aspects of spatial brain function. Moreover, both dopamine and spatial cognition decline sharply during age, raising the question which effect dopamine has on directional signals in the brain of older adults. To investigate these questions, we used a double-blind cross-over L-DOPA/Placebo intervention design in which 43 younger and 37 older adults navigated in a virtual spatial environment while undergoing functional magnetic resonance imaging (fMRI). We studied the effect of L-DOPA, a dopamine precursor, on fMRI activation patterns that encode spatial walking directions that have previously been shown to lose specificity with age. This was done in predefined regions of interest, including the early visual cortex, retrosplenial cortex, and hippocampus. Classification of brain activation patterns associated with different walking directions was improved across all regions following L-DOPA administration, suggesting that dopamine broadly enhances neural representations of direction. No evidence for differences between regions was found. In the hippocampus these results were found in both age groups, while in the retrosplenial cortex they were only observed in younger adults. Taken together, our study provides evidence for a link between dopamine and the specificity of neural responses during spatial navigation. SIGNIFICANCE STATEMENT: The sense of direction is an important aspect of spatial navigation, and neural representations of direction can be found throughout a large network of space-related brain regions. But what influences how well these representations track someone's true direction? Using a double-blind cross-over L-DOPA/Placebo intervention design, we find causal evidence that the neurotransmitter dopamine impacts the fidelity of direction selective neural representations in the human hippocampus and retrosplenial cortex. Interestingly, the effect of L-DOPA was either equally present or even smaller in older adults, despite the well-known age related decline of dopamine. These results provide novel insights into how dopamine shapes the neural representations that underlie spatial navigation.


Assuntos
Levodopa , Navegação Espacial , Humanos , Idoso , Levodopa/farmacologia , Dopamina/fisiologia , Navegação Espacial/fisiologia , Mapeamento Encefálico/métodos , Imageamento por Ressonância Magnética
11.
Perception ; 50(10): 876-889, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34549649

RESUMO

As face masks have become more commonplace in many regions due to COVID-19, concerns have been raised about their effects on the perception of mask wearers and social cohesion more broadly, including racial profiling. In two studies we examined the effects of masks on social judgments of mask wearers, and whether masks have different effects on judgments of Black and White faces. Participants rated 20 Black and 20 White faces with and without masks on trustworthiness/approachability (Studies 1 and 2) and on dominance/competence and attractiveness (Study 2). In both studies masks increased perceived trustworthiness and reduced the effect of face race on judgments. Masks also increased perceived attractiveness, but had no effect on the perception of dominance/competence. Overall, this study found no negative effects of face masks on judgments of mask wearers, though further research is needed.


Assuntos
COVID-19/prevenção & controle , Reconhecimento Facial , Máscaras , Percepção Social , COVID-19/epidemiologia , Humanos , Julgamento , Reconhecimento Psicológico , SARS-CoV-2 , Confiança
12.
Vet Surg ; 50(2): 365-374, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33421172

RESUMO

OBJECTIVE: To report on the feasibility, indications, and diagnostic yield of cone beam computed tomography (CBCT) of horses' extremities performed under standing sedation. STUDY DESIGN: Retrospective clinical case series. SAMPLE POPULATION: Fifty-nine CBCT examinations in 58 horses. METHODS: Examinations were categorized for indications for CBCT dependent on a suspicion, presence, or absence of a diagnosis prior to CBCT. The number of acquisitions per examination, total time for the examination, diagnostic score of each acquisition (diagnostic, diagnostic-compromised, nondiagnostic), and additional diagnostic information regarding preexisting diagnostic information were recorded. RESULTS: Three (median) acquisitions were performed per examination in a median study time of 14 minutes. In 24 of 33 cases with a suspected diagnosis, this diagnosis was confirmed or definitively refuted; in seven of 33 cases, the suspected diagnosis was refuted without a new diagnosis; and, in two of 33 cases, the suspected diagnosis could not be confirmed nor could a new diagnosis be made. In five of nine cases without a preexisting diagnosis, a diagnosis was established. In 16 cases with a diagnosis prior to CBCT, additional information was recorded, or a surgical plan was prepared. In 14 of 18 cases in which additional contrast techniques were used, additional information was gained. CONCLUSION: Standing CBCT of the horses' extremities is feasible and can produce diagnostic information in a timely fashion. CLINICAL SIGNIFICANCE: The results provide evidence of the practicality and diagnostic potential of standing CBCT of horses' extremities.


Assuntos
Tomografia Computadorizada de Feixe Cônico/veterinária , Membro Anterior/diagnóstico por imagem , Membro Posterior/diagnóstico por imagem , Doenças dos Cavalos/diagnóstico por imagem , Animais , Tomografia Computadorizada de Feixe Cônico/métodos , Sedação Consciente/veterinária , Estudos de Viabilidade , Feminino , Doenças dos Cavalos/diagnóstico , Cavalos , Masculino , Estudos Retrospectivos , Posição Ortostática , Suíça
13.
J Am Chem Soc ; 142(30): 12976-12986, 2020 07 29.
Artigo em Inglês | MEDLINE | ID: mdl-32597176

RESUMO

Covalent triazine frameworks are an emerging material class that have shown promising performance for a range of applications. In this work, we report on a metal-assisted and solvent-mediated reaction between calcium carbide and cyanuric chloride, as cheap and commercially available precursors, to synthesize two-dimensional triazine structures (2DTSs). The reaction between the solvent, dimethylformamide, and cyanuric chloride was promoted by calcium carbide and resulted in dimethylamino-s-triazine intermediates, which in turn undergo nucleophilic substitutions. This reaction was directed into two dimensions by calcium ions derived from calcium carbide and induced the formation of 2DTSs. The role of calcium ions to direct the two-dimensionality of the final structure was simulated using DFT and further proven by synthesizing molecular intermediates. The water content of the reaction medium was found to be a crucial factor that affected the structure of the products dramatically. While 2DTSs were obtained under anhydrous conditions, a mixture of graphitic material/2DTSs or only graphitic material (GM) was obtained in aqueous solutions. Due to the straightforward and gram-scale synthesis of 2DTSs, as well as their photothermal and photodynamic properties, they are promising materials for a wide range of future applications, including bacteria and virus incapacitation.

14.
Opt Express ; 28(19): 28306-28323, 2020 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-32988105

RESUMO

The overdetermination of the mathematical problem underlying ptychography is reduced by a host of experimentally more desirable settings. Furthermore, reconstruction of the sample-induced phase shift is typically limited by uncertainty in the experimental parameters and finite sample thicknesses. Presented is a conjugate gradient descent algorithm, regularized optimization for ptychography (ROP), that recovers the partially known experimental parameters along with the phase shift, improves resolution by incorporating the multislice formalism to treat finite sample thicknesses, and includes regularization in the optimization process, thus achieving reliable results from noisy data with severely reduced and underdetermined information.

15.
Mediators Inflamm ; 2020: 8704896, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32714091

RESUMO

Human periodontal ligament stromal cells (hPDLSCs) and gingival mesenchymal stromal cells (hGMSCs) are resident mesenchymal stromal cells (MSCs) of the periodontal tissue. The lipopolysaccharide (LPS) from Porphyromonas gingivalis is structurally distinct from that of other Gram-negative bacteria, and earlier studies linked this structural difference to a distinct virulence activity and the ability to activate toll-like receptor 2 (TLR-2), besides TLR-4 as commonly occurring upon LPS challenge. Later studies, in contrast, argue that TLR-2 activation by P. gingivalis LPS is due to lipoprotein contamination. In the present study, we aimed to define the influence of structure versus purity of P. gingivalis LPS on the immune response of hPDLSCs and hGMSCs. Cells were stimulated with commercially available "standard" P. gingivalis LPS, "ultrapure" P. gingivalis LPS, or "ultrapure" Escherichia coli LPS, and the expression of interleukin- (IL-) 8, IL-6, monocyte chemoattractant protein- (MCP-) 1, TLR-2, and TLR-4 was evaluated. The contribution of TLR-4 to the LPS-induced response was assessed using the specific TLR-4 inhibitor TAK-242. "Standard" P. gingivalis LPS induced significantly higher IL-8, IL-6, and MCP-1 production compared to the "ultrapure" LPS preparations, with no significant difference detectable for "ultrapure" LPS from P. gingivalis and E. coli. By using TAK-242, the response of hPDLSCs and hGMSCs to "ultrapure" LPS preparations was effectively inhibited to the levels comparable to those of nonstimulated controls. In contrast, high levels of response to "standard" LPS were observed, even in the presence of TAK-242. Our data show that the response of MSCs from periodontal tissue to LPS depends more on the purity of the LPS preparation than on the LPS source. Even a small amount of contaminating lipoproteins can drastically enhance the hPDLSCs' and hGMSCs; responsiveness to P. gingivalis LPS, which might also contribute to the progression of periodontal disease.


Assuntos
Lipopolissacarídeos/farmacologia , Células-Tronco Mesenquimais/citologia , Porphyromonas gingivalis/citologia , Sobrevivência Celular/fisiologia , Células Cultivadas , Quimiocina CCL2/metabolismo , Ensaio de Imunoadsorção Enzimática , Humanos , Interleucina-6/metabolismo , Interleucina-8/metabolismo , Células-Tronco Mesenquimais/efeitos dos fármacos , Ligamento Periodontal/citologia , Ligamento Periodontal/metabolismo , Reação em Cadeia da Polimerase , Receptor 2 Toll-Like/metabolismo , Receptor 4 Toll-Like/metabolismo
16.
Vet Surg ; 49(7): 1367-1377, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32652599

RESUMO

OBJECTIVE: To determine the influence of a purpose-built frame on the accuracy of screw placement during computer-assisted orthopedic surgery (CAOS) of the equine extremity. STUDY DESIGN: Experimental cadaveric study. SAMPLE POPULATION: Twenty-four paired equine cadaveric limbs obtained from seven horses. METHODS: Three 4.5-mm cortex screws were inserted in lag technique in three different planes of orientation in the proximal phalanx (P1) by means of CAOS. In the study group (n = 12 limbs), the tracker was anchored on a purpose-built frame designed to stabilize the extremity. In the control group (n = 12 limbs), a conventional tracker array was used that was anchored directly on P1. The stability of both tracker arrays was assessed during the procedure by using fiducial markers. After screw placement, preoperative and postoperative computed tomographic images were assessed to measure surgical accuracy aberrations (SAA) between the planned and achieved screw position. Descriptive statistics and repeated-measures analysis of variance were performed to compare SAA measurements between the study and control group. RESULTS: Both tracker arrays remained consistently stable in all specimens. Mean overall SAA of screw insertion were lower in the study group (0.7 mm; median, 0.5; range 0-3.4) than in the control group (1.2 mm; median, 0.9; range, 0-4.2 mm). CONCLUSION: The mean SAA achieved in cortex screw placement using CAOS lies within the range of approximately 1 mm. The use of a purpose-built frame avoided additional drilling of the target bone and improved surgical accuracy compared with the conventional tracker array. CLINICAL SIGNIFICANCE: The purpose-built frame described in this report can be used to facilitate CAOS in equine orthopedics without compromising surgical accuracy.


Assuntos
Parafusos Ósseos/veterinária , Membro Anterior/cirurgia , Membro Posterior/cirurgia , Cavalos/cirurgia , Procedimentos Ortopédicos/veterinária , Cirurgia Assistida por Computador/veterinária , Animais , Cadáver , Procedimentos Ortopédicos/instrumentação , Procedimentos Ortopédicos/métodos , Cirurgia Assistida por Computador/instrumentação , Cirurgia Assistida por Computador/métodos
17.
Vet Surg ; 49(6): 1075-1087, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32677115

RESUMO

OBJECTIVE: To describe clinical applications of computer-assisted orthopedic surgery (CAOS) in horses with a navigation system coupled with a cone beam computed tomography unit. STUDY DESIGN: Retrospective clinical case series. ANIMALS: Thirteen adult horses surgically treated with CAOS. METHODS: Medical records were searched for horses that underwent CAOS between 2016 and 2019. Data retrieved included signalment, diagnosis, lameness grade prior to surgery, surgical technique and complications, anesthesia and surgery time, and information pertaining to the perioperative case management and outcome. RESULTS: In 10 cases, surgical implants were placed in the proximal phalanx, third metatarsal bone, ulna, or medial femoral condyle. In one case, navigated transarticular drilling was performed to promote ankylosis of the distal tarsal joints. In another case, an articular fragment of the middle phalanx was removed with the help of CAOS guidance. In the final case, a focal osteolytic lesion of the calcaneal tuber was curetted with the aid of CAOS. In seven cases, a purpose-built frame was used for the surgical procedure. All surgeries were performed successfully and according to the preoperative plan. CONCLUSION: Computer-assisted orthopedic surgery can be an integral part of the clinical case management in equine surgery. To optimize workflow and time-efficiency, the authors recommend designating one team for operative planning and another for the execution of the surgical plan. Specialized equipment, such as the purpose-built frame, will further improve CAOS applications in equine surgery. CLINICAL SIGNIFICANCE: After they have become familiar with the operational principles, equine surgeons can readily apply CAOS for a broad spectrum of indications.


Assuntos
Tomografia Computadorizada de Feixe Cônico/veterinária , Cavalos/cirurgia , Procedimentos Ortopédicos/veterinária , Cirurgia Assistida por Computador/veterinária , Animais , Feminino , Membro Anterior/cirurgia , Membro Posterior/cirurgia , Masculino , Procedimentos Ortopédicos/métodos , Estudos Retrospectivos , Cirurgia Assistida por Computador/métodos , Articulações Tarsianas/cirurgia
18.
Environ Sci Technol ; 53(3): 1453-1462, 2019 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-30623663

RESUMO

Monomeric brominated flame retardants often pose risks to the environment. The new group of polymeric flame retardants is claimed to be a safer alternative due to their high molecular weight and persistence by design. Within this publication, the degradation of a commercially widely applied example of this group-the polymer "Polymeric FR"-was studied during UV irradiation and long-term exposure to heat (60 °C) for up to 36 weeks. Both treatments led to a variety of degradation products, which might have potentially adverse environmental effects and an increased mobility compared to the mother polymer. Besides identifying some of the possible degradation products (including for instance 2,4,6-tribromo-3-hydroxybenzoic acid), the degradation via UV irradiation, which yields 75 different degradation products, and via heat, which led to significantly less products, was compared. In addition, further parameters like TOC and the concentration of free bromine were studied and it was demonstrated that the used type of water (distilled, reconstituted, and rainwater) does not influence the outcome of the degradation experiments.


Assuntos
Retardadores de Chama , Hidrocarbonetos Bromados , Bromo , Temperatura Alta , Polímeros , Raios Ultravioleta
19.
Phys Chem Chem Phys ; 21(32): 17662-17672, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31364626

RESUMO

We apply inline electron holography to investigate the electrostatic potential across an individual BaZr0.9Y0.1O3 grain boundary. With holography, we measure a grain boundary potential of -1.3 V. Electron energy loss spectroscopy analyses indicate that barium vacancies at the grain boundary are the main contributors to the potential well in this sample. Furthermore, geometric phase analysis and density functional theory calculations suggest that reduced atomic density at the grain boundary also contributes to the experimentally measured potential well.

20.
Vet Surg ; 48(1): 21-28, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30367692

RESUMO

OBJECTIVE: To describe a closed castration technique in standing equids, report associated complications, and identify potential risk factors. STUDY DESIGN: Prospective cohort study of 300 standing equids that were castrated with the Henderson Equine Castrating Instrument. METHODS: Thirteen participating veterinarians recorded intraoperative difficulties and postoperative complications. Descriptive statistics, univariate analyses with Fisher's exact tests, and logistic regressions were used to evaluate intraoperative difficulties and postoperative complications and to assess risk factors for postoperative complications. RESULTS: Data were collected on 300 equids (269 horses, 23 ponies, and 8 donkeys). Intraoperative difficulties were experienced in 39 of 300 (13%) procedures. Postoperative complications were reported in 69 of 300 (23%) equids, including excessive swelling (29, 9.67%), surgical site infection (SSI; 27, 9%), severe hemorrhage (3, 1%), and prolapse of the omentum (2, 0.64%). Donkeys were at increased risk of severe hemorrhage (2/8, 25%, P = .0019). Equids that were castrated in a hospital setting (83/300, 27.66%) more frequently developed excessive swelling (P = .0034, odds ratio [OR] = 3.20) and SSI (P = .0047, OR = 3.18) compared with equids that were castrated in a field setting (217/300, 72.33%). Prolonging antimicrobial prophylaxis or age of the equid at the time of castration had no effect on the prevalence of excessive swelling or SSI. CONCLUSION: The method of castration evaluated here resulted in a similar prevalence of postoperative complications to that previously reported for castrations in standing horses but fewer SSI. CLINICAL SIGNIFICANCE: The described method provides a viable option for castrating horses and ponies, but is not recommended in donkeys.


Assuntos
Castração/veterinária , Equidae/cirurgia , Doenças dos Cavalos/etiologia , Cavalos/cirurgia , Complicações Pós-Operatórias/veterinária , Animais , Castração/efeitos adversos , Castração/métodos , Doenças dos Cavalos/epidemiologia , Doenças dos Cavalos/patologia , Masculino , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/patologia , Estudos Prospectivos , Fatores de Risco , Suíça/epidemiologia
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