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1.
Appl Opt ; 62(35): 9353-9360, 2023 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-38108707

RESUMO

An optical system for multichannel coupling of laser arrays to polymer waveguide array probes with a single biconvex lens is developed. The developed cylindrical module with 13 mm and 20 mm in diameter and length, respectively, enables coupling of eight individual optical channels using an aspheric lens. Specific coupling with crosstalk below -13d B for each channel and quasi-uniform coupling over all channels is achieved for a waveguide array with 100 µm lateral facet pitch at the incoupling site. The polymer waveguide technology allows for tapering of the lateral waveguide pitch to 25 µm toward the tip of the flexible waveguide array. SU-8 and PMMA are used as the waveguide core and cladding, respectively. The optical coupling module is designed as a prototype for preclinical evaluation of optical neural stimulators.

2.
Plant Cell Rep ; 43(1): 22, 2023 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-38150091

RESUMO

KEY MESSAGE: A novel plant binary expression system was developed from the compactin biosynthetic pathway 27 of Penicillium citrinum ML-236B. The system achieved >fivefold activation of gene expression in 28 transgenic tobacco. A diverse and well-characterized genetic toolset is fundamental to achieve the overall goals of plant synthetic biology. To properly coordinate expression of a multigene pathway, this toolset should include binary systems that control gene expression at the level of transcription. In plants, few highly functional, orthogonal transcriptional regulators have been identified. Here, we describe the process of developing synthetic plant transcription factors using regulatory elements from the Penicillium citrinum ML-236B (compactin) pathway. This pathway contains several genes including mlcA and mlcC that are transcriptionally regulated in a dose-dependent manner by the activator mlcR. In Nicotiana benthamiana, we first expressed mlcR with several cognate synthetic promoters driving expression of GFP. Synthetic promoters contained operator sequences from the compactin gene cluster. Following identification of the most active synthetic promoter, the DNA-binding domain from mlcR was used to generate chimeric transcription factors containing variable activation domains, including QF from the Neurospora crassa Q-system. Activity was measured at both protein and RNA levels which correlated with an R2 value of 0.94. A synthetic transcription factor with a QF activation domain increased gene expression from its synthetic promoter up to sixfold in N. benthamiana. Two systems were characterized in transgenic tobacco plants. The QF-based plants maintained high expression in tobacco, increasing expression from the cognate synthetic promoter by fivefold. Transgenic plants and non-transgenic plants were morphologically indistinguishable. The framework of this study can easily be adopted for other putative transcription factors to continue improvement of the plant synthetic biology toolbox.


Assuntos
Penicillium , Biologia Sintética , Nicotiana/genética , Plantas Geneticamente Modificadas/genética , Fatores de Transcrição/genética
3.
ACS Synth Biol ; 11(8): 2741-2755, 2022 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-35901078

RESUMO

While the installation of complex genetic circuits in microorganisms is relatively routine, the synthetic biology toolbox is severely limited in plants. Of particular concern is the absence of combinatorial analysis of regulatory elements, the long design-build-test cycles associated with transgenic plant analysis, and a lack of naming standardization for cloning parts. Here, we use previously described plant regulatory elements to design, build, and test 91 transgene cassettes for relative expression strength. Constructs were transiently transfected into Nicotiana benthamiana leaves and expression of a fluorescent reporter was measured from plant canopies, leaves, and protoplasts isolated from transfected plants. As anticipated, a dynamic level of expression was achieved from the library, ranging from near undetectable for the weakest cassette to a ∼200-fold increase for the strongest. Analysis of expression levels in plant canopies, individual leaves, and protoplasts were correlated, indicating that any of the methods could be used to evaluate regulatory elements in plants. Through this effort, a well-curated 37-member part library of plant regulatory elements was characterized, providing the necessary data to standardize construct design for precision metabolic engineering in plants.


Assuntos
Nicotiana , Biologia Sintética , DNA/metabolismo , Folhas de Planta/genética , Folhas de Planta/metabolismo , Plantas Geneticamente Modificadas/genética , Biologia Sintética/métodos , Nicotiana/genética
4.
Science ; 377(6603): 285-291, 2022 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-35857591

RESUMO

Carbonaceous asteroids, such as (101955) Bennu, preserve material from the early Solar System, including volatile compounds and organic molecules. We report spacecraft imaging and spectral data collected during and after retrieval of a sample from Bennu's surface. The sampling event mobilized rocks and dust into a debris plume, excavating a 9-meter-long elliptical crater. This exposed material is darker, spectrally redder, and more abundant in fine particulates than the original surface. The bulk density of the displaced subsurface material was 500 to 700 kilograms per cubic meter, which is about half that of the whole asteroid. Particulates that landed on instrument optics spectrally resemble aqueously altered carbonaceous meteorites. The spacecraft stored 250 ± 101 grams of material, which will be delivered to Earth in 2023.

5.
Front Plant Sci ; 13: 873480, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35548302

RESUMO

Phytosensors are genetically engineered plant-based sensors that feature synthetic promoters fused to reporter genes to sense and report the presence of specific biotic and abiotic stressors on plants. However, when induced reporter gene output is below detectable limits, owing to relatively weak promoters, the phytosensor may not function as intended. Here, we show modifications to the system to amplify reporter gene signal by using a synthetic transcription factor gene driven by a plant pathogen-inducible synthetic promoter. The output signal was unambiguous green fluorescence when plants were infected by pathogenic bacteria. We produced and characterized a phytosensor with improved sensing to specific bacterial pathogens with targeted detection using spectral wavelengths specific to a fluorescence reporter at 3 m standoff detection. Previous attempts to create phytosensors revealed limitations in using innate plant promoters with low-inducible activity since they are not sufficient to produce a strong detectable fluorescence signal for standoff detection. To address this, we designed a pathogen-specific phytosensor using a synthetic promoter-transcription factor system: the S-Box cis-regulatory element which has low-inducible activity as a synthetic 4xS-Box promoter, and the Q-system transcription factor as an amplifier of reporter gene expression. This promoter-transcription factor system resulted in 6-fold amplification of the fluorescence after infection with a potato pathogen, which was detectable as early as 24 h post-bacterial infection. This novel bacterial pathogen-specific phytosensor potato plant demonstrates that the Q-system may be leveraged as a powerful orthogonal tool to amplify a relatively weak synthetic inducible promoter, enabling standoff detection of a previously undetectable fluorescence signal. Pathogen-specific phytosensors would be an important asset for real-time early detection of plant pathogens prior to the display of disease symptoms on crop plants.

6.
Nat Commun ; 13(1): 1387, 2022 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-35297401

RESUMO

Tailored nanoscale quantum light sources, matching the specific needs of use cases, are crucial building blocks for photonic quantum technologies. Several different approaches to realize solid-state quantum emitters with high performance have been pursued and different concepts for energy tuning have been established. However, the properties of the emitted photons are always defined by the individual quantum emitter and can therefore not be controlled with full flexibility. Here we introduce an all-optical nonlinear method to tailor and control the single photon emission. We demonstrate a laser-controlled down-conversion process from an excited state of a semiconductor quantum three-level system. Based on this concept, we realize energy tuning and polarization control of the single photon emission with a control-laser field. Our results mark an important step towards tailored single photon emission from a photonic quantum system based on quantum optical principles.

7.
Space Sci Rev ; 218(2): 5, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35250103

RESUMO

Two of the instruments onboard the OSIRIS-REx spacecraft, the MapCam color imager and the OVIRS visible and infrared spectrometer, observed the surface of asteroid (101955) Bennu in partially overlapping wavelengths. Significant scientific advances have been enabled by using data from these two instruments in tandem, but a robust statistical understanding of their relationship is needed for future analyses to cross-compare their data as accurately and sensitively as possible. Here we present a cross-instrument comparison of data acquired by MapCam and OVIRS, including methods and results for all global and site-specific observation campaigns in which both instruments were active. In our analysis, we consider both the absolute radiometric offset and the relative (normalized) variation between the two instruments; we find that both depend strongly on the photometric and instrumental conditions during the observation. The two instruments have a large absolute offset (>15%) due to their independent radiometric calibrations. However, they are very consistent (relative offset as low as 1%) when each instrument's response is normalized at a single wavelength, particularly at low phase angles where shadows on Bennu's rough surface are minimized. We recommend using the global datasets acquired at 12:30 pm local solar time for cross-comparisons; data acquired at higher phase angles have larger uncertainties.

8.
Anaesthesiologie ; 71(6): 426-436, 2022 06.
Artigo em Alemão | MEDLINE | ID: mdl-34748025

RESUMO

BACKGROUND: Timely emergency surgery is vital as this often has a direct impact on morbidity and mortality. The joint recommendations of the German Associations of Anesthesiologists (BDA), Surgeons (BDC), and Operating Room Management (VOp.M) for coordinative implementation have been available since 2016: N0 (surgery immediately), N1 (surgery start in the next free operating room), N2 (surgery start ≤ 6 h), N3 (surgery at the end of the elective schedule), N4/Urgent (surgery within 12-24 h). The aim of this study was to describe the situation of care in German hospitals of different sizes for the first time using routine data. METHODS: The data were collected in 26 hospitals with different levels of care over a period of 10 days. The frequency distribution of the individual emergency categories and the duration from the notification of the operation to the start of anesthesia or surgery were examined for the hospital as a whole and for the four operating departments with a typically high ratio of emergencies: general surgery, trauma surgery, gynecology/obstetrics and urology. RESULTS: A total of 1603 emergency surgical interventions were analyzed. The number of N0 cases was very low due to the specific entity of these emergencies, N1 made up approximately 13-15% of emergencies and categories N2-N4/Urgent comprised approximately 25-32% of emergencies each. The average duration between the notification of the operation and the start of anesthesia or surgery was (min): N0 20.7 ± 14.3 and 43.6 ± 31.8, N1 61.5 ± 48.7 and 90.1 ± 56.1, N2 187.9 ± 152.0 and 220.5 ± 153.4, N3 394.5 ± 392.3 and 428.3 ± 397.9 and N4/Urgent 494.8 ± 484.4 and 519.6 ± 486.6, respectively. The distribution of the emergency categories did not differ significantly between community hospitals compared to tertiary care hospitals, including university hospitals (p = 0.731) and also the duration between notification and start of anesthesia and operation was similar. Significant differences depending on the service level were only found for N1 until the start of anesthesia and for N3 until the start of anesthesia and of surgery. General surgery classified as N3 has a significantly shorter implementation time in community hospitals compared to tertiary care hospitals, including university hospitals, both at the start of anesthesia (mean 287.8 min versus 417.1 min; p = 0.045) and at the start of surgery (mean 316.3 min versus 459.0 min; p = 0.032). The implementation of trauma surgery emergencies classified as N1 took place, based on the start of surgery in community hospitals with an average duration of 91.2 min, statistically significantly faster than in hospitals with a maximum care of 133.0 min (p = 0.036). In urology, there were notable variations between smaller and larger hospitals in emergency interventions with the classification N4/Urgent for both periods of time, both up to the start of anesthesia (p = 0.012) and up to the start of surgery (p = 0.007). At an average of 291.8 min (start of anesthesia) or 294.4 min (start of surgery), the implementation time in hospitals with maximum care, including university hospitals, was shorter than in urological clinics of community providers (626.5 min and 645.6 min, respectively). In gynecology/obstetrics, there was no statistically significant difference between the two groups. CONCLUSION: Cases with high urgency were surgically treated within a short time period. Overall, differences in time management of emergencies were only small between hospital types. The gradations in the temporal implementation of the individual emergency categories were due particularly to distinctions in the resources available, such as the number of operating theaters, including the run times.


Assuntos
Anestesia , Anestesiologia , Emergências , Feminino , Hospitais Universitários , Humanos , Salas Cirúrgicas , Gravidez
9.
Thromb J ; 19(1): 105, 2021 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-34937572

RESUMO

BACKGROUND: Antithrombin deficiency (ATD) is an autosomal dominant thrombophilia presenting with varying phenotypes. In pediatric patients with ATD, thrombosis typically develops during the neonatal period or adolescence. However, to date there are no consistent recommendations on the therapeutic management of children with ATD. Inferior vena cava atresia (IVCA) belongs to a range of congenital or acquired vena cava malformations and is described as an independent risk factor for thrombosis. The present case report explores two cases of combined ATD and IVCA in an adolescent and his mother. CASE PRESENTATION: A 14-year-old male presented with extensive deep venous thromboses (DVTs) of both lower extremities as well as an IVCA. The patient had previously been diagnosed with an asymptomatic ATD without therapeutic consequences at that time. His mother was suffering from an ATD and had herself just been diagnosed with IVCA, too. The DVTs in the adolescent were treated by systemic anticoagulation and catheter-directed local thrombolysis causing favourable results. Yet, despite adequate oral anticoagulation the DVTs in both lower extremities reoccurred within 1 week after the patient was discharged from hospital. This time, thrombolysis could not be fully achieved. Surprisingly, probing and stenting of the IVCA was achieved, indicating an acquired IVCA which could have occurred after undetected thrombosis in early childhood. Genetic analyses showed the same mutation causing ATD in both son and mother: heterozygote missense mutation c.248 T > C, p.(Leu83Pro), within the heparin binding domain of antithrombin. This mutation was never reported in mutation databases before. CONCLUSIONS: To our knowledge this is the first case report discussing combined ATD and IVCA in two family members. Since ATDs present with clinical heterogeneity, taking a thorough family history is crucial for the anticipation of possible complications in affected children and decisions on targeted diagnostics and therapeutic interventions. Affected families must be educated on risk factors and clinical signs of thrombosis and need an immediate diagnostic workup in case of clinical symptoms. IVCA in patients with ATD could occur due to thrombotic occlusion at a very early age. Therefore, in case of family members with IVCA and ATD ultrasound screening in newborns should be considered.

10.
Anaesthesist ; 70(12): 1003-1010, 2021 12.
Artigo em Alemão | MEDLINE | ID: mdl-34003303

RESUMO

BACKGROUND: This study aimed to determine the current state of implementation of the recommendations for the classification of emergency surgery published in 2016 by the German societies of anesthesiology (BDA/DGAI), surgery (BDC/DGCH) and operating room management (VOPM). METHODS: Based on these societies' recommendations, various organizational issues were explored using an online questionnaire that was limited to German operating room (OR) managers and coordinators for hospitals that had surgical programs and at least 200 hospital beds. RESULTS: A total of 550 hospitals were contacted and 274 participated in the survey (49.8%). Of these 70.7% reported that they had implemented the recommendations, and 15.2% were aware of the recommendations but did not consistently apply them. Of the participating OR managers and coordinators that had either implemented or were aware of the recommendations, 78.2% agreed that the standardized definition of medical emergencies led to improvements in emergency treatment but 33.6% stated that the defined response intervals for emergency categories induced a certain degree of subjectivity in categorizing emergencies. Additional in-house guidelines specifically for the most frequent surgeries were or would be welcomed by 80.1% of the respondents and 39.1% of the surveyed hospitals had already implemented such guidelines. Of the OR managers and coordinators, 62.9% were informed about their emergency volumes and 47.3% stated that they regularly assessed them. There was no dedicated capacity for emergency care in 65.2% of hospitals. Of the respondents 3.9% stated that a separate emergency OR was reserved with a freely available team, which, during core operating hours, could be used for interdisciplinary emergency care and 26.2% of hospitals considered the capacity required for emergency procedures when planning the OR program or determining OR capacities. CONCLUSION: The recommendations for classifying emergency operations are an essential and generally accepted control mechanism in OR coordination. They simplify interdisciplinary coordination and communication when dynamically incorporating emergency procedures into an OR program. Most OR managers and coordinators view the recommendations as improving the speed of action in emergency care. To support the adoption of emergency classifications within an organization it may be advisable to incorporate them into the OR statutes and integrate them within the hospital information systems. The majority of participants supported additional specifications based on medical indicators for classifying the most frequent emergency operations. Being cognizant of key metrics concerning in-house emergency volume represents a crucial basis for interdisciplinary OR management and emergency care integration. Contrary to common perception, blocking fixed OR capacities remains the exception. When establishing a concept to provide emergency capacity, it is advisable to align developments with demand calculations based on in-house figures and to emphasize interdisciplinary participation and consensus.


Assuntos
Anestesiologia , Serviços Médicos de Emergência , Serviço Hospitalar de Emergência , Humanos , Salas Cirúrgicas , Inquéritos e Questionários
11.
J Chem Phys ; 154(15): 154501, 2021 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-33887920

RESUMO

We performed rheological measurements of the typical deep eutectic solvents (DESs) glyceline, ethaline, and reline in a very broad temperature and dynamic range, extending from the low-viscosity to the high-viscosity supercooled-liquid regime. We find that the mechanical compliance spectra can be well described by the random free-energy barrier hopping model, while the dielectric spectra on the same materials involve significant contributions arising from reorientational dynamics. The temperature-dependent viscosity and structural relaxation time, revealing non-Arrhenius behavior typical for glassy freezing, are compared to the ionic dc conductivity and relaxation times determined by broadband dielectric spectroscopy. For glyceline and ethaline, we find essentially identical temperature dependences for all dynamic quantities. These findings point to a close coupling of the ionic and molecular translational and reorientational motions in these systems. However, for reline, the ionic charge transport appears decoupled from the structural and reorientational dynamics, following a fractional Walden rule. In particular, at low temperatures, the ionic conductivity in this DES is enhanced by about one decade compared to expectations based on the temperature dependence of the viscosity. The results for all three DESs can be understood without invoking a revolving-door mechanism previously considered as a possible charge-transport mechanism in DESs.

12.
Anaesthesist ; 70(9): 772-784, 2021 09.
Artigo em Alemão | MEDLINE | ID: mdl-33660043

RESUMO

BACKGROUND: The number of high-risk patients undergoing surgery is steadily increasing. In order to maintain and, if necessary, optimize perioperative hemodynamics as well as the oxygen supply to the organs (DO2) in this patient population, a timely assessment of cardiac function and the underlying pathophysiological causes of hemodynamic instability is essential for the anesthesiologist. A variety of hemodynamic monitoring procedures are available for this purpose; however, due to method-immanent limitations they are often not able to directly identify the underlying cause of cardiovascular impairment. OBJECTIVE: To present a stepwise algorithm for a perioperative echocardiography-based hemodynamic optimization in noncardiac surgery high-risk patients. In this context, echocardiography on demand according to international guidelines can be performed under certain conditions (hemodynamic instability, nonresponse to hemodynamic treatment) as well as in the context of a planned intraoperative procedure, mostly as a transesophageal echocardiography. METHODS AND RESULTS: Hemodynamically focused echocardiography as a rapidly available bedside method, enables the timely diagnosis and assessment of cardiac filling obstructions, volume status and volume response, right and left heart function, and the function of the heart valves. CONCLUSION: Integrating all echocardiographic findings in a differentiated assessment of the patient's cardiovascular function enables a (patho)physiologically oriented and individualized hemodynamic treatment.


Assuntos
Ecocardiografia Transesofagiana , Ecocardiografia , Anestesiologistas , Coração , Hemodinâmica , Humanos
13.
Anaesthesist ; 70(2): 171-184, 2021 02.
Artigo em Alemão | MEDLINE | ID: mdl-33410921

RESUMO

Pulmonary aspiration of solid components leads to displacement of the tracheobronchial tree, the aspiration of acidic gastric juices to chemical pneumonitis (Mendelson's syndrome) and the aspiration of oropharyngeal secretions or gastrointestinal pathogens to aspiration pneumonia. Principally, pulmonary aspiration can occur at any stage of anesthesia. In the clinical routine the aim must therefore be to identify those patients who have an increased risk of aspiration. When this is successful, measures can be taken to reduce the risk; these can be regional anaesthesia or the performance of general anaesthesia as rapid sequence induction (RSI). If severe pulmonary aspiration occurs despite all preventive measures, mostly during induction of anaesthesia, extensive experience and rapid action are necessary. This can only be achieved if the induction to RSI is performed by three persons with supervision of the trainee anaesthetist by a consultant anaesthetist.


Assuntos
Anestesiologia , Pneumonia Aspirativa , Anestesia Geral , Humanos , Intubação Intratraqueal , Indução e Intubação de Sequência Rápida
14.
Anaesthesist ; 70(2): 112-120, 2021 02.
Artigo em Alemão | MEDLINE | ID: mdl-32970160

RESUMO

BACKGROUND: Sepsis-associated encephalopathy (SAE) is one of the most frequent causes of neurocognitive impairment in intensive care patients. It is associated with increased hospital mortality and poor long-term neurocognitive outcome. To date there are no evidence-based recommendations for the diagnostics and neuromonitoring of SAE. OBJECTIVE: The aim of the study was to evaluate the current clinical practice of diagnostics and neuromonitoring of SAE on intensive care units (ICU) in Germany. MATERIAL AND METHODS: Based on available literature focusing on SAE, a questionnaire consisting of 26 items was designed and forwarded to 438 members of the Scientific Working Group for Intensive Care Medicine (WAKI) and the Scientific Working Group for Neuroanesthesia (WAKNA) as an online survey. RESULTS: The total participation rate in the survey was 12.6% (55/438). A standardized diagnostic procedure of SAE was reported by 21.8% (12/55) of the participants. The majority of participants preferred delirium screening tools (50/55; 90.9%) and the clinical examination (49/55; 89.1%) to detect SAE. Brain imaging (26/55; 47.3%), laboratory/biomarker determination (15/55; 27.3%), electrophysiological techniques (14/55; 25.5%) and cerebrospinal fluid examination (12/55; 21.8%) are less frequently performed. The follow-up examination of SAE is most frequently performed by a clinical examination (45/55; 81.8%). Neuromonitoring techniques, such as continuous electroencephalography (31/55; 56.4%), transcranial doppler sonography (31/55; 56.4%) and near-infrared spectroscopy (18/55, 32.7%) are not frequently used. We observed statistically significant differences between the theoretically attributed importance and clinical practice. The great majority of respondents (48/55; 87.3%) endorse the development of guidelines containing recommendations for diagnostics and neuromonitoring in SAE. DISCUSSION: This explorative survey demonstrated a great heterogeneity in diagnostics and neuromonitoring of SAE in German ICUs. Uniform concepts have not yet been established but are desired by the majority of study participants. Innovative biomarkers of neuroaxonal injury in blood and cerebrospinal fluid as well as electrophysiological and brain imaging techniques could provide valuable prognostic information on the neurocognitive outcome of patients and would thus be a useful addition to the clinical assessment of ICU patients with SAE.


Assuntos
Encefalopatia Associada a Sepse , Encéfalo , Cuidados Críticos , Humanos , Unidades de Terapia Intensiva , Inquéritos e Questionários
15.
J Clin Monit Comput ; 35(2): 229-243, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32458170

RESUMO

The number of high-risk patients undergoing surgery is growing. To maintain adequate hemodynamic functioning as well as oxygen delivery to the vital organs (DO2) amongst this patient population, a rapid assessment of cardiac functioning is essential for the anesthesiologist. Pinpointing any underlying cardiovascular pathophysiology can be decisive to guide interventions in the intraoperative setting. Various techniques are available to monitor the hemodynamic status of the patient, however due to intrinsic limitations, many of these methods may not be able to directly identify the underlying cause of cardiovascular impairment. Hemodynamic focused echocardiography, as a rapid diagnostic method, offers an excellent opportunity to examine signs of filling impairment, cardiac preload, myocardial contractility and the function of the heart valves. We thus propose a 6-step-echocardiographic approach to assess high-risk patients in order to improve and maintain perioperative DO2. The summary of all echocardiographic based findings allows a differentiated assessment of the patient's cardiovascular function and can thus help guide a (patho)physiological-orientated and individualized hemodynamic therapy.


Assuntos
Ecocardiografia , Hemodinâmica , Anestesiologistas , Coração , Humanos , Monitorização Fisiológica
16.
Sci Adv ; 6(41)2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33033037

RESUMO

Thermal inertia and surface roughness are proxies for the physical characteristics of planetary surfaces. Global maps of these two properties distinguish the boulder population on near-Earth asteroid (NEA) (101955) Bennu into two types that differ in strength, and both have lower thermal inertia than expected for boulders and meteorites. Neither has strongly temperature-dependent thermal properties. The weaker boulder type probably would not survive atmospheric entry and thus may not be represented in the meteorite collection. The maps also show a high-thermal inertia band at Bennu's equator, which might be explained by processes such as compaction or strength sorting during mass movement, but these explanations are not wholly consistent with other data. Our findings imply that other C-complex NEAs likely have boulders similar to those on Bennu rather than finer-particulate regoliths. A tentative correlation between albedo and thermal inertia of C-complex NEAs may be due to relative abundances of boulder types.

17.
Science ; 370(6517)2020 11 06.
Artigo em Inglês | MEDLINE | ID: mdl-33033155

RESUMO

The composition of asteroids and their connection to meteorites provide insight into geologic processes that occurred in the early Solar System. We present spectra of the Nightingale crater region on near-Earth asteroid Bennu with a distinct infrared absorption around 3.4 micrometers. Corresponding images of boulders show centimeters-thick, roughly meter-long bright veins. We interpret the veins as being composed of carbonates, similar to those found in aqueously altered carbonaceous chondrite meteorites. If the veins on Bennu are carbonates, fluid flow and hydrothermal deposition on Bennu's parent body would have occurred on kilometer scales for thousands to millions of years. This suggests large-scale, open-system hydrothermal alteration of carbonaceous asteroids in the early Solar System.

18.
Trends Plant Sci ; 25(12): 1176-1179, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32891561

RESUMO

Until recently, robust autoluminescence in plants has proven elusive. Two recent pioneering manuscripts (Khakhar et al. and Mitiouchkina et al.) expand our understanding of fungal bioluminescence to provide a new blueprint for engineering autoluminescence in plants. Here we discuss translating a fungal bioluminescence pathway into plants, along with potential future applications.


Assuntos
Fungos , Plantas , Luciferases , Plantas/genética
19.
J Chem Phys ; 153(1): 014502, 2020 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-32640802

RESUMO

We have performed a dielectric investigation of the ionic charge transport and the relaxation dynamics in plastic crystalline 1-cyano-adamantane (CNA) and in two mixtures of CNA with the related plastic crystals adamantane or 2-adamantanon. Ionic charge carriers were provided by adding 1% of Li salt. The molecules of these compounds have nearly globular shape and, thus, the so-called revolving-door mechanism assumed to promote ionic charge transport via molecular reorientations in other PC electrolytes should not be active here. Indeed, a comparison of the dc resistivity and the reorientational α-relaxation times in the investigated PCs reveals complete decoupling of both dynamics. Similar to other PCs, we find a significant mixing-induced enhancement of the ionic conductivity. Finally, these solid-state electrolytes reveal a second relaxation process, slower than the α-relaxation, which is related to ionic hopping. Due to the mentioned decoupling, it can be unequivocally detected and is not superimposed by the reorientational contributions as found for most other ionic conductors.

20.
Anaesthesist ; 69(11): 781-792, 2020 11.
Artigo em Alemão | MEDLINE | ID: mdl-32572502

RESUMO

Perioperative phases of hypotension are associated with an increase in postoperative complications and organ damage. Whereas some years ago hemodynamic stabilization was primarily carried out by volume supplementation, in recent years the use and dosing of cardiovascular-active substances has significantly increased. But like intravascular volume therapy, also substances with a cardiovascular effect have therapeutic margins, and thus, potential side effects. This review article discusses indications for each cardiovascular-active agent, weighing up advantages and disadvantages. Special attention is paid to the question how to administrate them: central venous catheter vs. peripheral indwelling venous cannula. The authors come to the conclusion that it is not a question of whether it is principally allowed to apply cardiovascular-active drugs via peripheral veins but more importantly, what should be taken into consideration if a peripheral venous access is used. This article provides concise recommendations.


Assuntos
Fármacos Cardiovasculares , Cateterismo Venoso Central , Cateteres Venosos Centrais , Hipotensão , Hemodinâmica , Humanos
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