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1.
EMBO J ; 39(19): e103889, 2020 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-32815200

RESUMEN

Plasticity of the proteome is critical to adapt to varying conditions. Control of mitochondrial protein import contributes to this plasticity. Here, we identified a pathway that regulates mitochondrial protein import by regulated N-terminal processing. We demonstrate that dipeptidyl peptidases 8/9 (DPP8/9) mediate the N-terminal processing of adenylate kinase 2 (AK2) en route to mitochondria. We show that AK2 is a substrate of the mitochondrial disulfide relay, thus lacking an N-terminal mitochondrial targeting sequence and undergoing comparatively slow import. DPP9-mediated processing of AK2 induces its rapid proteasomal degradation and prevents cytosolic accumulation of enzymatically active AK2. Besides AK2, we identify more than 100 mitochondrial proteins with putative DPP8/9 recognition sites and demonstrate that DPP8/9 influence the cellular levels of a number of these proteins. Collectively, we provide in this study a conceptual framework on how regulated cytosolic processing controls levels of mitochondrial proteins as well as their dual localization to mitochondria and other compartments.


Asunto(s)
Adenilato Quinasa/metabolismo , Dipeptidil-Peptidasas y Tripeptidil-Peptidasas/metabolismo , Proteínas Mitocondriales/metabolismo , Complejo de la Endopetidasa Proteasomal/metabolismo , Proteolisis , Células HEK293 , Células HeLa , Humanos , Transporte de Proteínas
2.
Ann Surg ; 277(4): e885-e892, 2023 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-35129468

RESUMEN

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.


Asunto(s)
Fístula Pancreática , Pancreaticoduodenectomía , Humanos , Pancreaticoduodenectomía/efectos adversos , Pancreaticoduodenectomía/métodos , Fístula Pancreática/epidemiología , Fístula Pancreática/etiología , Pancreatectomía/efectos adversos , Pancreatectomía/métodos , Factores de Riesgo , Complicaciones Posoperatorias/etiología , Morbilidad , Estudios Retrospectivos
3.
Sensors (Basel) ; 23(12)2023 Jun 19.
Artículo en Inglés | MEDLINE | ID: mdl-37420879

RESUMEN

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.


Asunto(s)
Robótica , Humanos , Actividades Humanas , Percepción Visual
4.
Small ; 18(15): e2107381, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-35218608

RESUMEN

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.


Asunto(s)
ADN , Microfluídica , Vidrio , Almacenamiento y Recuperación de la Información , Temperatura
5.
Phys Rev Lett ; 129(11): 116802, 2022 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-36154419

RESUMEN

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.

6.
Langmuir ; 38(51): 16067-16072, 2022 Dec 27.
Artículo en Inglés | MEDLINE | ID: mdl-36512752

RESUMEN

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.

7.
Langmuir ; 38(37): 11191-11198, 2022 09 20.
Artículo en Inglés | MEDLINE | ID: mdl-36083165

RESUMEN

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.


Asunto(s)
Nanopartículas , Dióxido de Silicio , ADN/genética , Glutatión , Oxidantes , Sustancias Reductoras , Tolueno/análogos & derivados
8.
Indoor Air ; 32(1): e12945, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34676590

RESUMEN

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.


Asunto(s)
Contaminación del Aire Interior , Dióxido de Silicio , Aerosoles , ADN , Humanos , Ventilación
9.
Environ Sci Technol ; 55(10): 6867-6875, 2021 05 18.
Artículo en Inglés | MEDLINE | ID: mdl-33901401

RESUMEN

Environmental tracers are chemical species that move with a fluid and allow us to understand its origin and material transport properties. DNA-based materials have been proposed and used for tracing due to their potential for multitracing with high specificity and sensitivity. For large-scale applications of this new material it is of interest to understand its impact on the environment. We therefore assessed the ecotoxicity of sub-micron silica particles with and without encapsulated DNA in the context of surface and underground tracing of natural waterflows using standard ecotoxicity assays according to ISO standards. Acute toxicity tests were performed with Daphnia magna (48 h), showing no effect on mobility at tracer concentrations below 300 ppm. Chronic ecotoxicological potential was tested with Raphidocelis subcapitata (green algae) (72 h) and Ceriodaphnia species (7 d) with no effect observed at realistic exposure scenario concentrations for both silica particles with and without encapsulated DNA. These results suggest that large-scale environmental tracing with DNA-tagged silica particles in the given exposure scenarios has a low impact on aquatic species with low trophic levels such as select algae and planktonic crustaceans.


Asunto(s)
Dióxido de Silicio , Contaminantes Químicos del Agua , Animales , ADN , Daphnia , Ecotoxicología , Dióxido de Silicio/toxicidad , Contaminantes Químicos del Agua/toxicidad
10.
Small ; 16(16): e1906934, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32162787

RESUMEN

3D nanoparticle assemblies offer a unique platform to enhance and extend the functionality and optical/electrical properties of individual nanoparticles. Especially, a self-supported, voluminous, and porous macroscopic material built up from interconnected semiconductor nanoparticles provides new possibilities in the field of sensing, optoelectronics, and photovoltaics. Herein, a method is demonstrated for assembling semiconductor nanoparticle systems containing building blocks possessing different composition, size, shape, and surface ligands. The method is based on the controlled destabilization of the particles triggered by trivalent cations (Y3+ , Yb3+ , and Al3+ ). The effect of the cations is investigated via X-ray photoelectron spectroscopy. The macroscopic, self-supported aerogels consist of the hyperbranched network of interconnected CdSe/CdS dot-in-rods, or CdSe/CdS as well as CdSe/CdTe core-crown nanoplatelets is used to demonstrate the versatility of the procedure. The non-oxidative assembly method takes place at room temperature without thermal activation in several hours and preserves the shape and the fluorescence of the building blocks. The assembled nanoparticle network provides longer exciton lifetimes with retained photoluminescence quantum yields, that make these nanostructured materials a perfect platform for novel multifunctional 3D networks in sensing. Various sets of photoelectrochemical measurements on the interconnected semiconductor nanorod structures also reveal the enhanced charge carrier separation.

11.
Int J Cancer ; 145(3): 614-620, 2019 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-30628063

RESUMEN

The lysine-specific demethylase 6A/UTX (gene name KDM6A) acts as a component of the COMPASS complex to control gene activation. UTX demethylates H3K27me2/3 at genes and enhancers. Deleterious mutations in KDM6A are found in many cancer types, prominently urothelial carcinoma and certain T-cell leukemias. In certain cancers, however, UTX supports oncogenic transcription factors, e.g. steroid hormone receptors in breast and prostate cancer. In fetal development, UTX regulates lineage choice and cell differentiation. Analogously, loss of UTX function in cancer may lead to metaplasia or impede differentiation. Likely because its function is contingent on its interacting transcription factors, the effects of UTX inactivation are not uniform and require detailed investigation in each cancer type. In urothelial carcinoma, in particular, the functional consequences of the frequent mutations in KDM6A and other COMPASS component genes are poorly understood. Nevertheless, UTX inactivation appears to sensitize many cancers to inhibitors of the H3K27 methyltransferase EZH2. Conversely, inhibitors of UTX enzymatic activity may be applicable in cancers with an oncogenic UTX function. Intriguingly, the fact that KDM6A is localized on the X-chromosome, but both copies are expressed, may account for gender-specific differences in cancer susceptibility. In conclusion, despite recent progress, many open questions need to be addressed, most importantly, the detailed mechanisms by which KDM6A inactivation promotes various cancers, but also with which proteins UTX interacts in and apart from the COMPASS complex, and to which extent its catalytic function is required for its tumor-suppressive function.


Asunto(s)
Histona Demetilasas/metabolismo , Neoplasias/enzimología , Animales , Humanos , Neoplasias/patología
12.
Sci Total Environ ; 947: 174533, 2024 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-38972412

RESUMEN

Redox conditions play a crucial role in determining the fate of many contaminants in groundwater, impacting ecosystem services vital for both the aquatic environment and human water supply. Geospatial machine learning has previously successfully modelled large-scale redox conditions. This study is the first to consolidate the complementary information provided by sediment color and water chemistry to enhance our understanding of redox conditions in Denmark. In the first step, the depth to the first redox interface is modelled using sediment color from 27,042 boreholes. In the second step, the depth of the first redox interface is compared against water chemistry data at 22,198 wells to classify redox complexity. The absence of nitrate containing water below the first redox interface is referred to as continuous redox conditions. In contrast, discontinuous redox conditions are identified by the presence of nitrate below the first redox interface. Both models are built using 20 covariate maps, encompassing diverse hydrologically relevant information. The first redox interface is modelled with a mean error of 0.0 m and a root-mean-squared error of 8.0 m. The redox complexity model attains an accuracy of 69.8 %. Results indicate a mean depth to the first redox interface of 8.6 m and a standard deviation of 6.5 m. 60 % of Denmark is classified as discontinuous, indicating complex redox conditions, predominantly collocated in clay rich glacial landscapes. Both maps, i.e., first redox interface and redox complexity are largely driven by the water table and hydrogeology. The developed maps contribute to our understanding of subsurface redox processes, supporting national-scale land-use and water management.

13.
Sci Rep ; 14(1): 5538, 2024 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-38448554

RESUMEN

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.

14.
J Phys Condens Matter ; 36(6)2023 Nov 06.
Artículo en Inglés | MEDLINE | ID: mdl-37871600

RESUMEN

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.

15.
Sci Total Environ ; 873: 162326, 2023 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-36842572

RESUMEN

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.

16.
Antioxidants (Basel) ; 12(8)2023 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-37627615

RESUMEN

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.

17.
GMS J Med Educ ; 40(4): Doc42, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37560038

RESUMEN

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.


Asunto(s)
Curriculum , Educación de Pregrado en Medicina , Humanos , Aprendizaje , Educación Continua , Atención a la Salud , Competencia Clínica , Alemania
18.
Biochim Biophys Acta Bioenerg ; 1864(1): 148932, 2023 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-36367491

RESUMEN

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.


Asunto(s)
Metanol , Tiosulfatos , Tiosulfatos/metabolismo , Metanol/metabolismo , NAD , Azufre/metabolismo , Sulfitos , Formiatos
19.
Children (Basel) ; 9(7)2022 Jul 04.
Artículo en Inglés | MEDLINE | ID: mdl-35883989

RESUMEN

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.

20.
Antimicrob Resist Infect Control ; 11(1): 4, 2022 01 10.
Artículo en Inglés | MEDLINE | ID: mdl-35012659

RESUMEN

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.


Asunto(s)
Infección Hospitalaria/transmisión , Infecciones por Bacterias Grampositivas/transmisión , Control de Infecciones , Nanopartículas/química , Habitaciones de Pacientes , Enterococos Resistentes a la Vancomicina/fisiología , ADN , Contaminación de Equipos , Fómites , Hospitales , Dióxido de Silicio/química , Suiza
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