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1.
Sci Rep ; 14(1): 5538, 2024 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-38448554

RESUMO

Globally, food production for an ever-growing population is a well-known threat to the environment due to losses of excess reactive nitrogen (N) from agriculture. Since the 1980s, many countries of the Global North, such as Denmark, have successfully combatted N pollution in the aquatic environment by regulation and introduction of national agricultural one-size-fits-all mitigation measures. Despite this success, further reduction of the N load is required to meet the EU water directives demands, and implementation of additional targeted N regulation of agriculture has scientifically and politically been found to be a way forward. In this paper, we present a comprehensive concept to make future targeted N regulation successful environmentally and economically. The concept focus is on how and where to establish detailed maps of the groundwater denitrification potential (N retention) in areas, such as Denmark, covered by Quaternary deposits. Quaternary deposits are abundant in many parts of the world, and often feature very complex geological and geochemical architectures. We show that this subsurface complexity results in large local differences in groundwater N retention. Prioritization of the most complex areas for implementation of the new concept can be a cost-efficient way to achieve lower N impact on the aquatic environment.

2.
J Phys Condens Matter ; 36(6)2023 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-37871600

RESUMO

Proximitized 2D materials present exciting prospects for exploring new quantum properties, enabled by precise control of structures and interfaces through epitaxial methods. In this study, we investigated the structure of ultrathin coverages formed by depositing high-Z element bismuth (Bi) on monolayer graphene (MLG)/SiC(0001). By utilizing electron diffraction and scanning tunneling microscopy, ultrathin Bi nanostructures epitaxially grown on MLG were studied. Deposition at 300 K resulted in formation of needle-like Bi(110)-terminated islands elongated in the zig-zag direction and aligned at an angle of approximately 1.75∘with respect to the MLG armchair direction. By both strain and quantum size effects, the shape, the orientation and the thickness of the Bi(110) islands can be rationalized. Additionally, a minority phase of Bi(110) islands orthogonally aligned to the former ones were seen. The four sub-domains of this minority structure are attributed to the formation of mirror twin boundaries, resulting in two potential alignments of Bi(110) majority and minority domains with respect to each other, in addition to two possible alignments of the majority domain with respect to graphene. Notably, an annealing step at 410 K or lowering the deposition temperature, significantly increases the concentration of the Bi(110) minority domain. Our findings shed light on the structural control of proximitized 2D materials, showcasing the potential for manipulating 2D interfaces.

3.
GMS J Med Educ ; 40(4): Doc42, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37560038

RESUMO

Background: Traditionally, direct medical competences are taught in medical studies, whereas leadership and quality management competences are hardly taught, although graduates are already confronted with management tasks at the beginning of their clinical work. With the upcoming amendment of the Medical Licensing Regulations, this topic area will probably be addressed and must be adequately taught by the faculties. The learning objectives in the area of quality management listed in the current working version of the German National Catalogue of Learning Objectives in Medicine (NKLM) 2.0 have so far been formulated in rather general terms and need to be concretized. Aim: To develop a competence-based learning objectives catalog for the topic area of quality management in medical studies as a structured framework recommendation for the design of faculty teaching-learning programs and as a suggestion for further development of the NKLM. Methods: The competence-based learning objectives catalog was developed by an eight-member working group "Quality Management in Education, Training and Continuing Education" of the Gesellschaft für Qualitätsmanagement in der Gesundheitsversorgung e.V. (GQMG) within the framework of a critical synthesis of central publications. The members of the project group have many years of project experience in quality management in health care as well as in university didactics. Results: Six basic competence goals as well as 10 specific competence goals could be formulated and consented upon. These are each flanked by a list of essential basic concepts and examples. These focus on quality improvements, including patient safety and treatment success against the background of a physician leadership role in an interprofessional context. Discussion: A competency-based set of learning objectives has been compiled that encompasses the necessary concepts and basic knowledge of quality management required for those entering the profession to understand and actively participate in quality management after completing medical school. To the authors' knowledge, no comparable learning objectives catalog is currently available for medical studies, even internationally.


Assuntos
Currículo , Educação de Graduação em Medicina , Humanos , Aprendizagem , Educação Continuada , Atenção à Saúde , Competência Clínica , Alemanha
4.
Antioxidants (Basel) ; 12(8)2023 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-37627615

RESUMO

In organisms that use reduced sulfur compounds as alternative or additional electron donors to organic compounds, transcriptional regulation of genes for enzymes involved in sulfur oxidation is needed to adjust metabolic flux to environmental conditions. However, little is known about the sensing and response to inorganic sulfur compounds such as thiosulfate in sulfur-oxidizing bacteria. In the Alphaproteobacterium Hyphomicrobium denitrificans, one strategy is the use of the ArsR-SmtB-type transcriptional regulator SoxR. We show that this homodimeric repressor senses sulfane sulfur and that it is crucial for the expression not only of sox genes encoding the components of a truncated periplasmic thiosulfate-oxidizing enzyme system but also of several other sets of genes for enzymes of sulfur oxidation. DNA binding and transcriptional regulatory activity of SoxR are controlled by polysulfide-dependent cysteine modification. The repressor uses the formation of a sulfur bridge between two conserved cysteines as a trigger to bind and release DNA and can also form a vicinal disulfide bond to orchestrate a response to oxidizing conditions. The importance of the sulfur bridge forming cysteines was confirmed by site-directed mutagenesis, mass spectrometry, and gel shift assays. In vivo, SoxR interacts directly or indirectly with a second closely related repressor, sHdrR.

5.
Sensors (Basel) ; 23(12)2023 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-37420879

RESUMO

This paper presents a novel method for online tool recognition in manual assembly processes. The goal was to develop and implement a method that can be integrated with existing Human Action Recognition (HAR) methods in collaborative tasks. We examined the state-of-the-art for progress detection in manual assembly via HAR-based methods, as well as visual tool-recognition approaches. A novel online tool-recognition pipeline for handheld tools is introduced, utilizing a two-stage approach. First, a Region Of Interest (ROI) was extracted by determining the wrist position using skeletal data. Afterward, this ROI was cropped, and the tool located within this ROI was classified. This pipeline enabled several algorithms for object recognition and demonstrated the generalizability of our approach. An extensive training dataset for tool-recognition purposes is presented, which was evaluated with two image-classification approaches. An offline pipeline evaluation was performed with twelve tool classes. Additionally, various online tests were conducted covering different aspects of this vision application, such as two assembly scenarios, unknown instances of known classes, as well as challenging backgrounds. The introduced pipeline was competitive with other approaches regarding prediction accuracy, robustness, diversity, extendability/flexibility, and online capability.


Assuntos
Robótica , Humanos , Atividades Humanas , Percepção Visual
6.
Sci Total Environ ; 873: 162326, 2023 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-36842572

RESUMO

Lake Urmia, located in northwest Iran, was among the world's largest hypersaline lakes but has now experienced a 7 m decrease in water level, from 1278 m to 1271 over 1996 to 2019. There is doubt as to whether the pixel-based analysis (PBA) approach's answer to the lake's drying is a natural process or a result of human intervention. Here, a non-parametric Mann-Kendall trend test was applied to a 21-year record (2000-2020) of satellite data products, i.e., temperature, precipitation, snow cover, and irrigated vegetation cover (IVC). The Google Earth Engine (GEE) cloud-computing platform utilized over 10 sub-basins in three provinces surrounding Lake Urmia to obtain and calculate pixel-based monthly and seasonal scales for the products. Canonical correlation analysis was employed in order to understand the correlation between variables and lake water level (LWL). The trend analysis results show significant increases in temperature (from 1 to 2 °C during 2000-2020) over May-September, i.e., in 87 %-25 % of the basin. However, precipitation has seen an insignificant decrease (from 3 to 9 mm during 2000-2019) in the rainy months (April and May). Snow cover has also decreased and, when compared with precipitation, shows a change in precipitation patterns from snow to rain. IVC has increased significantly in all sub-basins, especially the southern parts of the lake, with the West province making the largest contribution to the development of IVC. According to the PBA, this analysis underpins the very high contribution of IVC to the drying of the lake in more detail, although the contribution of climate change in this matter is also apparent. The development of IVC leads to increased water consumption through evapotranspiration and excess evaporation caused by the storage of water for irrigation. Due to the decreased runoff caused by consumption exceeding the basin's capacity, the lake cannot be fed sufficiently.

7.
Biochim Biophys Acta Bioenerg ; 1864(1): 148932, 2023 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-36367491

RESUMO

Many obligately heterotrophic methylotrophs oxidize thiosulfate as an additional electron source during growth on C1 compounds. Although two different pathways of thiosulfate oxidation are implemented in Hyphomicrobium denitrificans XT, a pronounced negative effect on growth rate is observed when it is cultured in the simultaneous presence of methanol and thiosulfate. In this model organism, periplasmic thiosulfate dehydrogenase TsdA catalyzes formation of the dead-end product tetrathionate. By reverse genetics we verified the second pathway that also starts in the periplasm where SoxXA catalyzes the oxidative fusion of thiosulfate to SoxYZ, from which sulfate is released by SoxB. Sulfane sulfur is then further oxidized in the cytoplasm by the sulfur-oxidizing heterodisulfide reductase-like system (sHdr) which is produced constitutively in a strain lacking the transcriptional repressor sHdrR. When exposed to thiosulfate, the ΔshdrR strain exhibited a strongly reduced growth rate even without thiosulfate in the pre-cultures. When grown on methanol, cells exhibit significantly increased NAD+/NADH ratios in the presence of thiosulfate. In contrast, thiosulfate did not exert any negative effect on growth rate or increase NAD+ levels during growth on formate. On both C1 substrates, excretion of up to 0.5 mM sulfite as an intermediate of thiosulfate (2 mM) oxidation was recorded. Sulfite is known to form adducts with pyrroloquinoline quinone, the cofactor of periplasmic methanol dehydrogenase. We rationalize that this causes specific inhibition of methanol degradation in the presence of thiosulfate while formate metabolism in the cytoplasm remains unaffected.


Assuntos
Metanol , Tiossulfatos , Tiossulfatos/metabolismo , Metanol/metabolismo , NAD , Enxofre/metabolismo , Sulfitos , Formiatos
8.
Ann Surg ; 277(4): e885-e892, 2023 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-35129468

RESUMO

OBJECTIVE: To assesses the prevalence and severity of CAS in patients undergoing PD/total pancreatectomy and its association with major postoperative complications after PD. SUMMARY OF BACKGROUND DATA: CAS may increase the risk of ischemic complications after PD. However, the prevalence of CAS and its relevance to major morbidity remain unknown. METHODS: All patients with a preoperative computed tomography with arterial phase undergoing partial PD or TP between 2014 and 2017 were identified from a prospective database. CAS was assessed based on computed tomography and graded according to its severity: no stenosis (<30%), grade A (30%-<50%), grade B (50%-≤80%), and grade C (>80%). Postoperative complications were assessed and uni- and multivariable risk analyses were performed. RESULTS: Of 989 patients, 273 (27.5%) had CAS: 177 (17.9%) with grade A, 83 (8.4%) with grade B, and 13 (1.3%) with grade C. Postoperative morbidity and 90-day mortality occurred in 278 (28.1%) patients and 41 (4.1%) patients, respectively. CAS was associated with clinically relevant pancreatic fistula ( P =0.019), liver perfusion failure ( P =0.003), gastric ischemia ( P =0.001), clinically relevant biliary leakage ( P =0.006), and intensive care unit ( P =0.016) and hospital stay ( P =0.001). Multivariable analyses confirmed grade B and C CAS as independent risk factors for liver perfusion failure; in addition, grade C CAS was an independent risk factor for clinically relevant pancreatic fistula and gastric complications. CONCLUSIONS: CAS is common in patients undergoing PD. Higher grade of CAS is associated with an increased risk for clinically relevant complications, including liver perfusion failure and postoperative pancreatic fistula. Precise radiological assessment may help to identify CAS. Future studies should investigate measures to mitigate CAS-associated risks.


Assuntos
Fístula Pancreática , Pancreaticoduodenectomia , Humanos , Pancreaticoduodenectomia/efeitos adversos , Pancreaticoduodenectomia/métodos , Fístula Pancreática/epidemiologia , Fístula Pancreática/etiologia , Pancreatectomia/efeitos adversos , Pancreatectomia/métodos , Fatores de Risco , Complicações Pós-Operatórias/etiologia , Morbidade , Estudos Retrospectivos
9.
Langmuir ; 38(51): 16067-16072, 2022 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-36512752

RESUMO

Bi-layer epitaxial graphene (BLG) on 6H-SiC(0001) (EG/SiC) was grown and modified by thermal deposition of the molecular electron acceptor tetrafluoro-tetra cyano quinodimethane (F4-TCNQ). The surface-modified system, F4-TCNQ/EG/SiC, was studied by X-ray photoelectron spectroscopy (XPS) and angle-resolved polarized Raman spectroscopy (ARPRS). XPS results indicate that bonding of deposited F4-TCNQ molecules depends on their concentration. Although bonding through the cyano groups is present at all concentrations, charge transfer from graphene to fluorine is evident only at sub-monolayer concentrations. The corresponding change in bond character is coupled with a change in molecular orientation. Raman spectroscopy not only provides results consistent with the findings from the XPS study but also reveals a significant degree of molecular stacking above the monolayer concentration. Thus, both the variation of the acceptor concentration and the number of graphene layers provide further handles to manipulate charge and doping that may be useful in device applications.

10.
Langmuir ; 38(37): 11191-11198, 2022 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-36083165

RESUMO

A core-shell strategy was developed to protect synthetic DNA in organosilica particles encompassing dithiol linkages allowing for a DNA loading of 1.1 wt %. DNA stability tests involving bleach as an oxidant showed that following the procedure DNA was sandwiched between core particles of ca. 450 nm size and a protective outer layer, separating the DNA from the environment. Rapid aging tests at 60 °C and 50% relative humidity revealed that the DNA protected within this material was significantly more stable than nonprotected DNA, with an expected ambient temperature half-life of over 60 years. Still, and due to the presence of the dithiol linkages in the backbone of the organosilica material, the particles degraded in the presence of reducing agents (TCEP and glutathione) and disintegrated within several days in a simulated compost environment, which was employed to test the biodegradability of the material. This is in contrast to DNA encapsulated following state of the art procedures in pure SiO2 particles, which do not biodegrade in the investigated timeframes and conditions. The results show that synthetic DNA protected within dithiol comprising organosilica particles presents a strategy to store digital data at a high storage capacity for long time frames in a fully biodegradable format.


Assuntos
Nanopartículas , Dióxido de Silício , DNA/genética , Glutationa , Oxidantes , Substâncias Redutoras , Tolueno/análogos & derivados
11.
Phys Rev Lett ; 129(11): 116802, 2022 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-36154419

RESUMO

Besides graphene, further honeycomb 2D structures were successfully synthesized on various surfaces. However, almost flat plumbene hosting topologically protected edge states could not yet be realized. In this Letter, we investigated the intercalation of Pb on buffer layers on SiC(0001). Thereby, suspended and charge neutral graphene emerged, and the intercalated Pb formed plumbene honeycomb lattices, which are rotated by ±7.5° with respect to graphene. Along with this twist, a proximity-induced modulation of the hopping parameter in graphene opens a band gap of around 30 meV at the Fermi energy, giving rise to a metal-insulator transition. Moreover, the edges of the intercalated plumbene layers revealed edge states within the gap of the conduction bands at around 1 eV as expected for charge neutral plumbene.

12.
Children (Basel) ; 9(7)2022 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-35883989

RESUMO

BACKGROUND/AIM: The pattern of lower-limb amputation, indications, complications, and revision in pediatric cases differs globally. Therefore, we conducted this study to describe the patterns of lower-limb amputation at our institution. METHODS: During a set period between 2010 and 2020, adolescent patients undergoing lower-limb amputation within the orthopedic department of Heidelberg University Hospital were retrospectively collected and analyzed. The retrieved dataset included two parts: data on lower-limb amputations and data on subsequent complications and revision surgeries at the same time. Besides patients' general information (age, gender), the dataset included data regarding amputation patterns (number, indications, and level of amputation, complications, and revision surgeries and their indications). RESULTS: Twenty-two patients undergoing lower-limb amputation were examined, of which the majority were males (63.6%) with a mean age of 12 (5.1) years. Tumor was the most common indication for amputation (72.7%), and transfemoral amputation was the most frequent level (68.2%). Complications occurred in 10 patients, mostly due to stump impalement or bony overgrowth. Of all recorded patients requiring revision, nine were regarding bone and one case regarding soft tissue. CONCLUSIONS: Lower-limb amputation in adolescents is a rare encounter and it is commonly indicated due to bone tumors. The thigh is the most common level of amputation. Postoperative complications are frequent, mainly secondary to bony overgrowth, and often require revision surgery.

13.
Sci Transl Med ; 14(638): eabi4632, 2022 03 30.
Artigo em Inglês | MEDLINE | ID: mdl-35353539

RESUMO

The origin and function of CD20+ T cells are poorly understood. Here, we characterized CD20+ T cells in mice and humans and investigated how they are affected by anti-CD20 antibody treatment. We report that murine CD20+ T cells are unable to endogenously express the B cell lineage marker CD20; the development of CD20+ T cells in rodents requires the presence of CD20-expressing B cells. Our results demonstrated that both murine and human T cells acquire CD20 from B cells via trogocytosis while being activated by an antigen-presenting B cell. In patients with multiple sclerosis (MS) and mice with experimental autoimmune encephalomyelitis (EAE), expression of CD20 on T cells is associated with an up-regulation of activation markers, proinflammatory cytokines, and adhesion molecules, suggesting high pathogenic potential. Supporting this hypothesis, CD20+ T cells expand during active EAE in rodents; furthermore, adoptive transfer of CD20+ T cells into EAE-diseased mice worsened histological and clinical severity. Of direct therapeutic relevance, we demonstrate that the exclusive therapeutic elimination of CD20+ T cells effectively ameliorates EAE, independent of B cells. The results support the hypothesis that CD20+ T cells arise upon B cell-T cell interaction and that depletion of CD20+ T cells might contribute to the success of anti-CD20 antibody therapies in MS and other inflammatory disorders.


Assuntos
Autoimunidade , Encefalomielite Autoimune Experimental , Animais , Antígenos CD20/uso terapêutico , Linfócitos B , Encefalomielite Autoimune Experimental/tratamento farmacológico , Humanos , Camundongos , Linfócitos T
14.
J Med Case Rep ; 16(1): 119, 2022 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-35313981

RESUMO

PURPOSE: During the severe acute respiratory syndrome coronavirus 2 pandemic, several patient groups are at particular risk. Mortality is higher among cancer patients and may be increased further by thromboembolic events, which are more common in coronavirus 2019 patients according to recent publications. We discuss the association of gynecologic malignancies, Severe acute respiratory syndrome coronavirus 2, and thromboembolism by reporting a case study and summarizing available literature. CASE REPORT: A 71-year-old Caucasian patient with ovarian cancer receiving first-line chemotherapy was diagnosed with deep vein thrombosis and pulmonary embolism. Routine screening revealed infection with severe acute respiratory syndrome coronavirus 2 in absence of specific symptoms. After uneventful recovery, oncologic treatment could be continued a few weeks later. METHODS: We performed a systematic review of the literature on PubMed following Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines. The search included articles ahead of print, published between 1 December 2019 and 1 June 2020. Cross-searches were conducted on all relevant articles. RESULTS: We identified five articles meeting the defined criteria, including two retrospective studies, a review, a position paper, as well as a letter to the editor. CONCLUSION: Cancer patients infected with severe acute respiratory syndrome coronavirus 2 have a relatively poor outcome, which may partially be due to a higher rate of thromboembolic events. Thromboprophylaxis is recommended, and scoring systems are helpful in early detection. In cancer patients with severe acute respiratory syndrome coronavirus 2, individual risk for thromboembolic events should be taken into account when considering interruption versus continuation of antitumoral therapy. However, further data and studies are required.


Assuntos
COVID-19 , Neoplasias dos Genitais Femininos , Tromboembolia Venosa , Idoso , Anticoagulantes/uso terapêutico , COVID-19/complicações , Feminino , Neoplasias dos Genitais Femininos/complicações , Humanos , Estudos Retrospectivos
15.
Small ; 18(15): e2107381, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35218608

RESUMO

Using DNA as a durable, high-density storage medium with eternal format relevance can address a future data storage deficiency. The proposed storage format incorporates dehydrated particle spots on glass, at a theoretical capacity of more than 20 TB per spot, which can be efficiently retrieved without significant loss of DNA. The authors measure the rapid decay of dried DNA at room temperature and present the synthesis of encapsulated DNA in silica nanoparticles as a possible solution. In this form, the protected DNA can be readily applied to digital microfluidics (DMF) used to handle retrieval operations amenable to full automation. A storage architecture is demonstrated, which can increase the storage capacity of today's archival storage systems by more than three orders of magnitude: A DNA library containing 7373 unique sequences is encapsulated and stored under accelerated aging conditions (4 days at 70 °C, 50% RH) corresponding to 116 years at room temperature and the stored information is successfully recovered.


Assuntos
DNA , Microfluídica , Vidro , Armazenamento e Recuperação da Informação , Temperatura
16.
Chem Commun (Camb) ; 58(19): 3174-3177, 2022 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-35171192

RESUMO

The resilience of ancient DNA (aDNA) in bone gives rise to the preservation of synthetic DNA with bioinorganic materials such as calcium phosphate (CaP). Accelerated aging experiments at elevated temperature and humidity displayed a positive effect of co-precipitated, crystalline dicalcium phosphate on the stability of synthetic DNA in contrast to amorphous CaP. Quantitative PXRD in combination with SEM and EDX measurements revealed distinct CaP phase transformations of calcium phosphate dihydrate (brushite) to anhydrous dicalcium phosphate (monetite) influencing DNA stability.


Assuntos
Materiais Biocompatíveis/química , Fosfatos de Cálcio/química , DNA/química , Teste de Materiais
17.
Sci Total Environ ; 822: 153464, 2022 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-35093341

RESUMO

Groundwater recharge quantification is essential for sustainable groundwater resources management, but typically limited to local and regional scale estimates. A high-resolution (1 km × 1 km) dataset consisting of long-term average actual evapotranspiration, effective precipitation, a groundwater recharge coefficient, and the resulting groundwater recharge map has been created for all of Europe using a variety of pan-European and seven national gridded datasets. As an initial step, the approach developed for continental scale mapping consists of a merged estimate of actual evapotranspiration originating from satellite data and the vegetation controlled Budyko approach to subsequently estimate effective precipitation. Secondly, a machine learning model based on the Random Forest regressor was developed for mapping groundwater recharge coefficients, using a range of covariates related to geology, soil, topography and climate. A common feature of the approach is the validation and training against effective precipitation, recharge coefficients and groundwater recharge from seven national gridded datasets covering the UK, Ireland, Finland, Denmark, the Netherlands, France and Spain, representing a wide range of climatic and hydrogeological conditions across Europe. The groundwater recharge map provides harmonised high-resolution estimates across Europe and locally relevant estimates for areas where this information is otherwise not available, while being consistent with the existing national gridded datasets. The Pan-European groundwater recharge pattern compares well with results from the global hydrological model PCR-GLOBWB 2. At country scale, the results were compared to a German recharge map showing great similarity. The full dataset of long-term average actual evapotranspiration, effective precipitation, recharge coefficients and groundwater recharge is available through the EuroGeoSurveys' open access European Geological Data Infrastructure (EGDI).


Assuntos
Água Subterrânea , Geologia , Hidrologia , Aprendizado de Máquina , Solo
18.
Antimicrob Resist Infect Control ; 11(1): 4, 2022 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-35012659

RESUMO

BACKGROUND: To establish effective infection control protocols, understanding pathogen transmission pathways is essential. Non-infectious surrogate tracers may safely explore these pathways and challenge pre-existing assumptions. We used silica nanoparticles with encapsulated DNA (SPED) for the first time in a real-life hospital setting to investigate potential transmission routes of vancomycin-resistant enterococci in the context of a prolonged outbreak. METHODS: The two study experiments took place in the 900-bed University Hospital Zurich, Switzerland. A three-run 'Patient experiment' investigated pathogen transmission via toilet seats in a two-patient room with shared bathroom. First, various predetermined body and fomite sites in a two-bed patient room were probed at baseline. Then, after the first patient was contaminated with SPED at the subgluteal region, both patients sequentially performed a toilet routine. All sites were consequently swabbed again for SPED contamination. Eight hours later, further spread was tested at predefined sites in the patient room and throughout the ward. A two-run 'Mobile device experiment' explored the potential transmission by mobile phones and stethoscopes in a quasi-realistic setting. All SPED contamination statuses and levels were determined by real-time qPCR. RESULTS: Over all three runs, the 'Patient experiment' yielded SPED in 59 of 73 (80.8%) predefined body and environmental sites. Specifically, positivity rates were 100% on subgluteal skin, toilet seats, tap handles, and entertainment devices, the initially contaminated patients' hands; 83.3% on patient phones and bed controls; 80% on intravenous pumps; 75% on toilet flush plates and door handles, and 0% on the initially not contaminated patients' hands. SPED spread as far as doctor's keyboards (66.6%), staff mobile phones (33.3%) and nurses' keyboards (33.3%) after eight hours. The 'Mobile device experiment' resulted in 16 of 22 (72.7%) positive follow-up samples, and transmission to the second patient occurred in one of the two runs. CONCLUSIONS: For the first time SPED were used to investigate potential transmission pathways in a real hospital setting. The results suggest that, in the absence of targeted cleaning, toilet seats and mobile devices may result in widespread transmission of pathogens departing from one contaminated patient skin region.


Assuntos
Infecção Hospitalar/transmissão , Infecções por Bactérias Gram-Positivas/transmissão , Controle de Infecções , Nanopartículas/química , Quartos de Pacientes , Enterococos Resistentes à Vancomicina/fisiologia , DNA , Contaminação de Equipamentos , Fômites , Hospitais , Dióxido de Silício/química , Suíça
19.
Indoor Air ; 32(1): e12945, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34676590

RESUMO

Aerosolized particles play a significant role in human health and environmental risk management. The global importance of aerosol-related hazards, such as the circulation of pathogens and high levels of air pollutants, have led to a surging demand for suitable surrogate tracers to investigate the complex dynamics of airborne particles in real-world scenarios. In this study, we propose a novel approach using silica particles with encapsulated DNA (SPED) as a tracing agent for measuring aerosol distribution indoors. In a series of experiments with a portable setup, SPED were successfully aerosolized, recaptured, and quantified using quantitative polymerase chain reaction (qPCR). Position dependency and ventilation effects within a confined space could be shown in a quantitative fashion achieving detection limits below 0.1 ng particles per m3 of sampled air. In conclusion, SPED show promise for a flexible, cost-effective, and low-impact characterization of aerosol dynamics in a wide range of settings.


Assuntos
Poluição do Ar em Ambientes Fechados , Dióxido de Silício , Aerossóis , DNA , Humanos , Ventilação
20.
J Hist Ideas ; 82(4): 569-591, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34840189

RESUMO

This article outlines what is arguably the uniquely German trajectory of the imagination, focusing on the relation between the imagination and "Urbild" in eighteenth-century German aesthetics, particularly in Kant and Schelling. I contend that shared German roots of the "Einbildung" (imagination) and "Urbild" (archetype) in "Bild" led German aesthetic thinkers to conceive of the imagination much more in (Neo-)Platonic terms. This article therefore argues that there is a perceptible rift in how the imagination is conceived in eighteenth-century discourse which follows a linguistic fault line between the Latin-origin "imagination" and the German "Einbildung."


Assuntos
Imaginação , Estética
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