135 research outputs found
Electrically Switchable Photonic Molecule Laser
We have studied the coherent intercavity coupling of the evanescent fields of
the whispering gallery modes of two terahertz quantum-cascade lasers
implemented as microdisk cavities. The electrically pumped single-mode
operating microcavities allow to electrically control the coherent mode
coupling for proximity distances of the cavities up to 30-40 \mu\m. The optical
emission of the strongest coupled photonic molecule can be perfectly switched
by the electrical modulation of only one of the coupled microdisks. The
threshold characteristics of the strongest coupled photonic molecule
demonstrates the linear dependence of the gain of a quantum-cascade laser on
the applied electric field.Comment: 4 pages, 4 figure
Biomarkers for CNS injury in CSF are elevated in COVID-19 and associated with neurological symptoms and disease severity
BACKGROUND: Neurological symptoms have been frequently reported in hospitalized patients with coronavirus disease 2019 (COVID-19) and biomarkers of CNS injury are reported to be increased in plasma but not extensively studied in CSF. This study examines CSF for biomarkers of CNS injury and other pathology in relation to neurological symptoms and disease severity in patients with neurological manifestations of COVID-19. METHODS: Nineteen patients with neurological symptoms and mild to critical COVID-19 were prospectively included. Extensive analysis of CSF, including measurement of biomarkers of CNS injury (neurofilament light chain protein (NfL) glial fibrillary acidic protein (GFAp) and total tau) was performed and related to neurological features and disease severity. RESULTS: Neurological symptoms included altered mental status (42%), headache (42%), central (21%) and peripheral weakness (32%). Two patients demonstrated minor pleocytosis and four patients had increased immunoglobulin G levels in CSF. Neuronal autoantibody testing using commercial tests was negative in all patients. Increased CSF levels of NfL, GFAp and total-tau protein were seen in 63%, 37%, and 16% of patients, respectively. Increased NfL correlated with disease severity, time in intensive care and level of consciousness. NfL in CSF was higher in patients with central neurological symptoms. CONCLUSION: Although limited by small sample size, our data suggest that levels of NfL, GFAp and total tau in CSF are commonly elevated in patients with COVID-19 with neurological symptoms. This is in contrast to the standard CSF work-up where pathological findings are scarce. NfL in particular, is associated with central neurological symptoms and disease severity
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Metaproteome analysis reveals that syntrophy, competition, and phage-host interaction shape microbial communities in biogas plants
Background: In biogas plants, complex microbial communities produce methane and carbon dioxide by anaerobic digestion of biomass. For the characterization of the microbial functional networks, samples of 11 reactors were analyzed using a high-resolution metaproteomics pipeline. Results: Examined methanogenesis archaeal communities were either mixotrophic or strictly hydrogenotrophic in syntrophy with bacterial acetate oxidizers. Mapping of identified metaproteins with process steps described by the Anaerobic Digestion Model 1 confirmed its main assumptions and also proposed some extensions such as syntrophic acetate oxidation or fermentation of alcohols. Results indicate that the microbial communities were shaped by syntrophy as well as competition and phage-host interactions causing cell lysis. For the families Bacillaceae, Enterobacteriaceae, and Clostridiaceae, the number of phages exceeded up to 20-fold the number of host cells. Conclusion: Phage-induced cell lysis might slow down the conversion of substrates to biogas, though, it could support the growth of auxotrophic microbes by cycling of nutrients. © 2019 The Author(s)
Anti-SARS-CoV2 antibody responses in serum and cerebrospinal fluid of COVID-19 patients with neurological symptoms
Antibody responses to SARS-CoV-2 in serum and CSF from 16 COVID-19 patients with neurological symptoms were assessed using two independent methods. IgG specific for the virus spike protein was found in 81% of cases in serum and in 56% in CSF. SARS-CoV-2 IgG in CSF was observed in two cases with negative serology. Levels of IgG in both serum and CSF were associated with disease severity (p<0.05). All patients with elevated markers of CNS damage in CSF also had CSF antibodies (p=0.002), and CSF antibodies had the highest predictive value for neuronal damage markers of all tested clinical variables
Systematic review of antiepileptic drugs’ safety and effectiveness in feline epilepsy
Understanding the efficacy and safety profile of antiepileptic drugs (AEDs) in feline epilepsy is a crucial consideration for managing this important brain disease. However, there is a lack of information about the treatment of feline epilepsy and therefore a systematic review was constructed to assess current evidence for the AEDs’ efficacy and tolerability in cats. The methods and materials of our former systematic reviews in canine epilepsy were mostly mirrored for the current systematic review in cats. Databases of PubMed, CAB Direct and Google scholar were searched to detect peer-reviewed studies reporting efficacy and/or adverse effects of AEDs in cats. The studies were assessed with regards to their quality of evidence, i.e. study design, study population, diagnostic criteria and overall risk of bias and the outcome measures reported, i.e. prevalence and 95% confidence interval of the successful and affected population in each study and in total
Microcavity-integrated graphene photodetector
There is an increasing interest in using graphene (1, 2) for optoelectronic applications. (3-19) However, because graphene is an inherently weak optical absorber (only ≈2.3% absorption), novel concepts need to be developed to increase the absorption and take full advantage of its unique optical properties. We demonstrate that by monolithically integrating graphene with a Fabry-Pérot microcavity, the optical absorption is 26-fold enhanced, reaching values >60%. We present a graphene-based microcavity photodetector with responsivity of 21 mA/W. Our approach can be applied to a variety of other graphene devices, such as electro-absorption modulators, variable optical attenuators, or light emitters, and provides a new route to graphene photonics with the potential for applications in communications, security, sensing and spectroscopy
International Veterinary Epilepsy Task Force recommendations for systematic sampling and processing of brains from epileptic dogs and cats
Traditionally, histological investigations of the epileptic brain are required to identify epileptogenic brain lesions, to evaluate the impact of seizure activity, to search for mechanisms of drug-resistance and to look for comorbidities. For many instances, however, neuropathological studies fail to add substantial data on patients with complete clinical work-up. This may be due to sparse training in epilepsy pathology and or due to lack of neuropathological guidelines for companion animals.
The protocols introduced herein shall facilitate systematic sampling and processing of epileptic brains and therefore increase the efficacy, reliability and reproducibility of morphological studies in animals suffering from seizures.
Brain dissection protocols of two neuropathological centres with research focus in epilepsy have been optimised with regards to their diagnostic yield and accuracy, their practicability and their feasibility concerning clinical research requirements.
The recommended guidelines allow for easy, standardised and ubiquitous collection of brain regions, relevant for seizure generation. Tissues harvested the prescribed way will increase the diagnostic efficacy and provide reliable material for scientific investigations
Coding of procedures documented by general practitioners in Swedish primary care-an explorative study using two procedure coding systems
<p>Abstract</p> <p>Background</p> <p>Procedures documented by general practitioners in primary care have not been studied in relation to procedure coding systems. We aimed to describe procedures documented by Swedish general practitioners in electronic patient records and to compare them to the Swedish Classification of Health Interventions (KVÅ) and SNOMED CT.</p> <p>Methods</p> <p>Procedures in 200 record entries were identified, coded, assessed in relation to two procedure coding systems and analysed.</p> <p>Results</p> <p>417 procedures found in the 200 electronic patient record entries were coded with 36 different Classification of Health Interventions categories and 148 different SNOMED CT concepts. 22.8% of the procedures could not be coded with any Classification of Health Interventions category and 4.3% could not be coded with any SNOMED CT concept. 206 procedure-concept/category pairs were assessed as a complete match in SNOMED CT compared to 10 in the Classification of Health Interventions.</p> <p>Conclusions</p> <p>Procedures documented by general practitioners were present in nearly all electronic patient record entries. Almost all procedures could be coded using SNOMED CT.</p> <p>Classification of Health Interventions covered the procedures to a lesser extent and with a much lower degree of concordance. SNOMED CT is a more flexible terminology system that can be used for different purposes for procedure coding in primary care.</p
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The health-related quality of life in a Swedish sample of HIV-infected persons
The purposes of the present study are (1) to assess the health-related quality of life (HRQOL) and the subjective health status in a sample of human immunodeficiency virus (HIV)-infected persons (2) to relate the results to different population groups and (3) to investigate the relationship of medical and demographic variables with HRQOL. A total of 72 HIV-infected men were included. They answered the Swedish health-related quality of life questionnaire and the health index. Demographic and medical data were obtained from the medical records. The data collection took place before entering a therapeutic HIV vaccine trial. The results showed a more negative impact on the HRQOL and subjective health status in the HIV-positive subjects, compared with male population groups. The dimensions of emotional well-being were most affected. When comparisons were made according to the medical and demographic variables for different subgroups within the HIV sample, differences in the physical-dimension scales were most prominent. Symptomatic HIV infection or acquired immunodeficiency syndrome (AIDS), anti-retroviral treatment, sick leave or disability pension, low income and basic education were associated with worse HRQOL and health status. In conclusion, it is of utmost importance to take into account, aspects of the patients' emotional well-being in nursing, as well as in medical care and interventions. Moreover, individualized caring programs are needed because the disruptions in HRQOL fluctuated within the HIV sample
Identity and distinctness in online interaction: encountering a problem for narrative accounts of self
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