Single photons and entangled photon pairs are a key resource of many quantum secure communication and quantum computation protocols, and non-Poissonian sources emitting in the low-loss wavelength ...region around 1,550 nm are essential for the development of fibre-based quantum network infrastructure. However, reaching this wavelength window has been challenging for semiconductor-based quantum light sources. Here we show that quantum dot devices based on indium phosphide are capable of electrically injected single photon emission in this wavelength region. Using the biexciton cascade mechanism, they also produce entangled photons with a fidelity of 87 ± 4%, sufficient for the application of one-way error correction protocols. The material system further allows for entangled photon generation up to an operating temperature of 93 K. Our quantum photon source can be directly integrated with existing long distance quantum communication and cryptography systems, and provides a promising material platform for developing future quantum network hardware.
We present two real-time reverse-transcription polymerase chain reaction assays for a novel human coronavirus (CoV), targeting regions upstream of the E gene (upE) or within open reading frame ...(ORF)1b, respectively. Sensitivity for upE is 3.4 copies per reaction (95% confidence interval (CI): 2.5–6.9 copies) or 291 copies/mL of sample. No cross-reactivity was observed with coronaviruses OC43, NL63, 229E, SARS-CoV, nor with 92 clinical specimens containing common human respiratory viruses. We recommend using upE for screening and ORF1b for confirmation.
Aim
Nitrogen use efficiency (NUE) in subtropical cropping systems is low causing a large quantity of reactive N loss to the environment. However, the mechanisms and pathways of such losses are poorly ...understood. The objectives of the research were to quantify N volatilization rates and corresponding NUE in a biochar and nitrapyrin-treated cabbage field using N-control as well as a
15
N-based approach.
Methods
The treatments consisted of: N-control, urea alone, urea with nitrapyrin (UN), urea with biochar (UB), and urea with biochar and nitrapyrin (UNB). In each plot,
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N-labeled urea was applied in 1 m
2
micro-plots to repeat the treatments.
Results
The UNB had higher (
p
< 0.001) crop yields than other treatments by 29, 23 and 16% over the urea, UN and UB treatments, respectively, while the UN and UB were also higher than the urea alone. The estimated
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N-based NUE was higher (
p
< 0.01) in the UNB (40%) than in the urea alone (32%) but similar to the UN (36%) and UB (38%). The N-control based calculation overestimated NUE by 2–13% relative to the
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N-based approach. The UNB treatment reduced NH
3
volatilization by 37, 22, and 33% over urea alone, UB and UN, respectively (
p
< 0.01). Post-harvest soil organic carbon (SOC) and total N were higher (
p
< 0.001) in the UNB and UB treatments than the other treatments.
Conclusion
Our results with a subtropical crop suggest that biochar alone or co-applied with nitrapyrin improves NUE and mitigates NH
3
volatilization while increasing SOC and TN contents.
Abstract Autologous chondrocyte implantation (ACI) is an established and well-accepted procedure for the treatment of localized full-thickness cartilage defects of the knee. The present review of the ...working group “Clinical Tissue Regeneration” of the German Society of Orthopedics and Trauma (DGOU) describes the biology and function of healthy articular cartilage, the present state of knowledge concerning therapeutic consequences of primary cartilage lesions and the suitable indication for ACI. Based on best available scientific evidence, an indication for ACI is given for symptomatic cartilage defects starting from defect sizes of more than 3–4 cm2; in the case of young and active sports patients at 2.5 cm2, while advanced degenerative joint disease needs to be considered as the most important contraindication. The present review gives a concise overview on important scientific background, the results of clinical studies and discusses the advantages and disadvantages of ACI.
Context. Methyl isocyanide (CH3NC) is the isocyanide with the largest number of atoms confirmed in the interstellar medium (ISM), but it is not an abundant molecule, having only been detected towards ...a handful of objects. Conversely, its isomer, methyl cyanide (CH3CN), is one of the most abundant complex organic molecules detected in the ISM, with detections in a variety of low- and high-mass sources. Aims. The aims of this work are to determine the abundances of methyl isocyanide in the solar-type protostellar binary IRAS 16293–2422 and to understand the stark abundance differences observed between methyl isocyanide and methyl cyanide in the ISM. Methods. We use Atacama Large Millimeter/submillimeter Array (ALMA) observations from the Protostellar Interferometric Line Survey (PILS) to search for methyl isocyanide and compare its abundance with that of its isomer methyl cyanide. We use a new line catalogue from the Cologne Database for Molecular Spectroscopy (CDMS) to identify methyl isocyanide lines. We also model the chemistry with an updated version of the three-phase chemical kinetics model MAGICKAL, presenting the first chemical modelling of methyl isocyanide to date. Results. We detect methyl isocyanide for the first time in a solar-type protostar, IRAS 16293–2422 B, and present upper limits for its companion protostar, IRAS 16293–2422 A. Methyl isocyanide is found to be at least 20 times more abundant in source B compared to source A, with a CH3CN/CH3NC abundance ratio of 200 in IRAS 16293–2422 B and >5517 in IRAS 16293–2422 A. We also present the results of a chemical model of methyl isocyanide chemistry in both sources, and discuss the implications for methyl isocyanide formation mechanisms and the relative evolutionary stages of both sources. The chemical modelling is unable to match the observed CH3CN/CH3NC abundance ratio towards the B source at densities representative of that source. The modelling, however, is consistent with the upper limits for the A source. There are many uncertainties in the formation and destruction pathways of methyl isocyanide, and it is therefore not surprising that the initial modelling attempts do not reproduce observations. In particular, it is clear that some destruction mechanism of methyl isocyanide that does not destroy methyl cyanide is needed. Furthermore, these initial model results suggest that the final density plays a key role in setting the abundance ratio. The next steps are therefore to obtain further detections of methyl isocyanide in more objects, as well as undertaking more detailed physico-chemical modelling of sources such as IRAS16293.
We describe SGC-GAK-1 (11), a potent, selective, and cell-active inhibitor of cyclin G-associated kinase (GAK), together with a structurally related negative control SGC-GAK-1N (14). 11 was highly ...selective in an in vitro kinome-wide screen, but cellular engagement assays defined RIPK2 as a collateral target. We identified 18 as a potent RIPK2 inhibitor lacking GAK activity. Together, this chemical probe set can be used to interrogate GAK cellular biology.
The removal efficiency of carbon (C) and nitrogen (N) in constructed wetlands (CWs) is very inconsistent and frequently does not reveal whether the removal processes are due to physical attenuation ...or whether the different species have been transformed to other reactive forms. Previous research on nutrient removal in CWs did not consider the dynamics of pollution swapping (the increase of one pollutant as a result of a measure introduced to reduce a different pollutant) driven by transformational processes within and around the system. This paper aims to address this knowledge gap by reviewing the biogeochemical dynamics and fate of C and N in CWs and their potential impact on the environment, and by presenting novel ways in which these knowledge gaps may be eliminated. Nutrient removal in CWs varies with the type of CW, vegetation, climate, season, geographical region, and management practices. Horizontal flow CWs tend to have good nitrate (NO3−) removal, as they provide good conditions for denitrification, but cannot remove ammonium (NH4+) due to limited ability to nitrify NH4+. Vertical flow CWs have good NH4+ removal, but their denitrification ability is low. Surface flow CWs decrease nitrous oxide (N2O) emissions but increase methane (CH4) emissions; subsurface flow CWs increase N2O and carbon dioxide (CO2) emissions, but decrease CH4 emissions. Mixed species of vegetation perform better than monocultures in increasing C and N removal and decreasing greenhouse gas (GHG) emissions, but empirical evidence is still scarce. Lower hydraulic loadings with higher hydraulic retention times enhance nutrient removal, but more empirical evidence is required to determine an optimum design. A conceptual model highlighting the current state of knowledge is presented and experimental work that should be undertaken to address knowledge gaps across CWs, vegetation and wastewater types, hydraulic loading rates and regimes, and retention times, is suggested. We recommend that further research on process-based C and N removal and on the balancing of end products into reactive and benign forms is critical to the assessment of the environmental performance of CWs.
ABSTRACT
The division between stripped-envelope supernovae (SE-SNe) and superluminous supernovae (SLSNe) is not well-defined in either photometric or spectroscopic space. While a sharp luminosity ...threshold has been suggested, there remains an increasing number of transitional objects that reach this threshold without the spectroscopic signatures common to SLSNe. In this work, we present data and analysis on four SNe transitional between SE-SNe and SLSNe; the He-poor SNe 2019dwa and 2019cri, and the He-rich SNe 2019hge and 2019unb. Each object displays long-lived and variable photometric evolution with luminosities around the SLSN threshold of Mr < −19.8 mag. Spectroscopically however, these objects are similar to SE-SNe, with line velocities lower than either SE-SNe and SLSNe, and thus represent an interesting case of rare transitional events.
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