Space-based quantum networking in the presence of a nuclear disturbed environment.

Space-based quantum networks provide a means for near-term long-distance transmission of quantum information. This article analyzed the performance of a downlink quantum network between a low-Earth-orbit satellite and an observatory operating in less-than-ideal atmospheric conditions. The effects from fog, haze, and a nuclear disturbed environment on the long-range distribution of quantum states were investigated. A density matrix that estimates the quantum state by capturing the effects from increased signal loss and elevated background noise to estimate the state fidelity of the transmitted quantum state was developed. It was found that the nuclear disturbed environment and other atmospheric effects have a degrading effect on the quantum state. These environments impede the ability to perform quantum communications for the duration of the effects. In the case of the nuclear disturbed environment, the nuclear effects subside quickly, and network performance should return to normal by the next satellite pass.

Bone Marrow Mesenchymal Stem Cell-Derived Extracellular Vesicle Infusion for the Treatment of Respiratory Failure From COVID-19: A Randomized, Placebo-Controlled Dosing Clinical Trial.

BACKGROUND: Bone marrow mesenchymal stem cell (BM-MSC)-derived extracellular vesicles (ExoFlo) convey the immunomodulatory and regenerative properties of intact BM-MSCs. This study aimed to determine the safety and efficacy of ExoFlo as treatment for moderate to severe ARDS in patients with severe COVID-19. RESEARCH QUESTION: Do two doses of ExoFlo safely reduce mortality in COVID-19-associated moderate to severe ARDS compared with placebo? STUDY DESIGN AND METHODS: A prospective phase 2 multicenter double-anonymized randomized placebo-controlled dosing trial was conducted at five sites across the United States with infusions of placebo, 10 mL of ExoFlo, or 15 mL of ExoFlo on days 1 and 4. Patients (N = 102) with COVID-19-associated moderate to severe ARDS were enrolled and randomized to treatment. Adverse events were documented throughout the study. The primary outcome measure was all-cause 60-day mortality rate. Secondary outcomes included time to death (overall mortality); the incidence of treatment-emergent serious adverse events; proportion of discharged patients at 7, 30, and 60 days; time to hospital discharge; and ventilation-free days. RESULTS: No treatment-related adverse events were reported. Mortality (60-day) in the intention-to-treat population was reduced with 15 mL ExoFlo mixed with 85 mL normal saline (ExoFlo-15) compared with placebo (not significant, χ2, P = .1343). For the post hoc subgroup analyses, 60-day mortality was decreased with ExoFlo-15 compared with placebo (relative risk, 0.385; 95% CI, 0.159-0.931; P = .0340; n = 50). With ExoFlo-15, a relative risk of 0.423 (95% CI, 0.173-1.032; P = .0588; n = 24) was determined for participants aged 18 to 65 years with moderate to severe ARDS. Ventilation-free days improved with ExoFlo-15 (P = .0455; n = 50) for all participants aged 18 to 65 years. INTERPRETATION: The 15 mL dose of ExoFlo was found to be safe in patients with severe or critical COVID-19-associated respiratory failure. In participants aged 18 to 65 years, the risk reduction in 60-day mortality was further improved from subjects of all ages in the intention-to-treat population after two doses of 15 mL of ExoFlo compared with placebo. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov; No.: NCT04493242; URL: www. CLINICALTRIALS: gov.

Broadband polarization-entangled source for C+L-band flex-grid quantum networks.

The rising demand for transmission capacity in optical networks has motivated steady interest in expansion beyond the standard C-band (1530-1565 nm) into the adjacent L-band (1565-1625 nm) for an approximate doubling of capacity in a single stroke. However, in the context of quantum networking, the L-band has yet to be fully leveraged with the suite of advanced tools for characterization and management available from classical lightwave communications. In this work, we demonstrate an ultrabroadband two-photon source integrating both C- and L-band wavelength-selective switches for complete control of spectral routing and allocation across 7.5 THz in a single setup. Polarization state tomography of all 150 pairs of 25-GHz-wide channels reveals an average fidelity of 0.98 and total distillable entanglement greater than 181 kebits/s. This source is explicitly designed for flex-grid optical networks and can facilitate optimal utilization of entanglement resources across the full C+L-band.

Effects of a nuclear disturbed environment on a quantum free space optical link.

This manuscript investigates the potential effect of a nuclear-disturbed atmospheric environment on the signal attenuation of a ground/satellite transmitter/receiver system for both classical optical and quantum communications applications. Attenuation of a signal transmitted through the rising nuclear cloud and the subsequently transported debris is modeled climatologically for surface-level detonations of 10 kt, 100 kt, and 1 Mt. Attenuation statistics were collected as a function of time after detonation. These loss terms were compared to normal loss sources such as clouds, smoke from fires, and clear sky operation. Finally, the loss was related to the degradation of transmitted entanglement derived from Bayesian mean estimation.

Agile frequency transformations for dense wavelength-multiplexed communications.

The broad bandwidth and spectral efficiency of photonics has facilitated unparalleled speeds in long-distance lightwave communication. Yet efficient routing and control of photonic information without optical-to-electrical conversion remains an ongoing research challenge. Here, we demonstrate a practical approach for dynamically transforming the carrier frequencies of dense wavelength-division-multiplexed data. Combining phase modulators and pulse shapers into an all-optical frequency processor, we realize both cyclic channel hopping and 1-to-N broadcasting of input data streams for systems with N = 2 and N = 3 users. Our method involves no optical-to-electrical conversion and enables low-noise, reconfigurable routing of fiber-optic signals with in principle arbitrary wavelength operations in a single platform, offering new potential for low-latency all-optical networking.

Characterizing photon number statistics using conjugate optical homodyne detection.

We study the problem of determining the photon number statistics of an unknown quantum state using conjugate optical homodyne detection. We quantify the information gain in a single-shot measurement and show that the photon number statistics can be recovered in repeated measurements on an ensemble of identical input states without scanning the phase of the input state or randomizing the phase of the local oscillator used in homodyne detection. We demonstrate how the expectation maximization algorithm and Bayesian inference can be utilized to facilitate the reconstruction and illustrate our approach by conducting experiments to study the photon number distributions of a weak coherent state and a thermal state source.

Graphene Oxide Involved Air-Controlled Electrospray for Uniform, Fast, Instantly Dry, and Binder-Free Electrode Fabrication.

We report a facile air-controlled electrospray method to directly deposit binder-free active materials/graphene oxide (GO) onto current collectors. This method is inspired from an electrospinning process, and possesses all the advantages that electrospinning has such as low cost, easy scaling up, and simultaneous solvent evaporation during the spraying process. Moreover, the spray slurry is only a simple mixture of active materials and GO suspension in water, no binder polymer, organic solvent, and conductive carbon required. In our research, high-capacity Si nanoparticles (Si NP, 70-100 nm) and SiO microparticles (SiO MP, 3-10 µm) were selected to demonstrate the capability of this method to accommodate particles with different sizes. Their mixture with GO was sprayed onto a collector and then thermally annealed in an inert gas to obtain Si NP or SiO MP/reduced graphene oxide (RGO) binder-free electrodes. We are also able to directly deposit fairly large electrode sheets (e.g., 12 × 21 in.) upon the application requirement. To the best of our knowledge, this is the simplest approach to produce Si-related materials/RGO layered structures directly on current collector with controllable area and loading. Si and SiO MP/RGO are evaluated in both half and full lithium cells, showing good electrochemical performance. Prelithiation is also studied and gives a high first cycle Coulombic efficiency. In addition to Si-related materials, other materials with different shapes and sizes (e.g., MoO3 nanobelts, Sn/carbon nanofibers, and commercial sulfur particles) can also be sprayed. Beyond the preparation of battery electrodes, this approach can also be applied for other types of electrode preparation such as that of a supercapacitor, fuel cell, and solar cell.

Superdense Coding over Optical Fiber Links with Complete Bell-State Measurements.

Adopting quantum communication to modern networking requires transmitting quantum information through a fiber-based infrastructure. We report the first demonstration of superdense coding over optical fiber links, taking advantage of a complete Bell-state measurement enabled by time-polarization hyperentanglement, linear optics, and common single-photon detectors. We demonstrate the highest single-qubit channel capacity to date utilizing linear optics, 1.665±0.018, and we provide a full experimental implementation of a hybrid, quantum-classical communication protocol for image transfer.

Induction of Pulmonary Granuloma Formation by Propionibacterium acnes Is Regulated by MyD88 and Nox2.

Sarcoidosis is characterized by noncaseating granulomas with an unknown cause that present primarily in the lung. Propionibacterium acnes, an immunogenic commensal skin bacterium involved in acne vulgaris, has been implicated as a possible causative agent of sarcoidosis. Here, we demonstrate that a viable strain of P. acnes isolated from a patient with sarcoidosis and instilled intratracheally into wild-type mice can generate pulmonary granulomas similar to those observed in patients with sarcoidosis. The formation of these granulomas is dependent on the administration of viable P. acnes. We also found that mice deficient in the innate immunity adapter protein MyD88 had a greater number and a larger area of granuloma lesions compared with wild-type mice administered P. acnes. Early after P. acnes administration, wild-type mice produced proinflammatory mediators and recruited neutrophils into the lung, a response that is dependent on MyD88. In addition, there was an increase in granuloma number and size after instillation with P. acnes in mice deficient in CybB, a critical component of nicotinamide adenine dinucleotide phosphate oxidase required for the production of reactive oxygen species in the phagosome. Myd88-/- or Cybb-/- mice both had increased persistence of P. acnes in the lung, together with enhanced granuloma formation. In conclusion, we have generated a mouse model of early granuloma formation induced by a clinically relevant strain of P. acnes isolated from a patient with sarcoidosis, and, using this model, we have shown that a deficiency in MyD88 or CybB is associated with impaired bacterial clearance and increased granuloma formation in the lung.

Graphene Folding in Si Rich Carbon Nanofibers for Highly Stable, High Capacity Li-Ion Battery Anodes.

Silicon nanoparticles (Si NPs) wrapped by graphene in carbon nanofibers were obtained via electrospinning and subsequent thermal treatment. In this study, water-soluble poly(vinyl alcohol) (PVA) with low carbon yield is selected to make the process water-based and to achieve a high silicon yield in the composite. It was also found that increasing the amount of graphene helps keep the PVA fiber morphology after carbonization, while forming a graphene network. The fiber SEM and HRTEM images reveal that micrometer graphene is heavily folded into sub-micron scale fibers during electrospinning, while Si NPs are incorporated into the folds with nanospace in between. When applied to lithium-ion battery anodes, the Si/graphene/carbon nanofiber composites show a high reversible capacity of ∼2300 mAh g(-1) at a charging rate of 100 mA/g and a stable capacity of 1191 mAh g(-1) at 1 A/g after more than 200 cycles. The interconnected graphene network not only ensures the excellent conductivity but also serves as a buffering matrix for the mechanic stress caused by volume change; the nanospace between Si NPs and folded graphene provides the space needed for volume expansion.

Enhanced Dispersion and Stability of Petroleum Coke Water Slurries via Triblock Copolymer and Xanthan Gum: Rheological and Adsorption Studies.

The rheology of petroleum coke (petcoke) water slurries was investigated with a variety of nonionic and anionic dispersants including poly(ethylene oxide) (PEO)-b-poly(propylene oxide) (PPO)-b-PEO triblock copolymers (trade name: Pluronic, BASF), poly(vinyl alcohol) (PVA), polyvinylpyrrolidone (PVP), poly(ethylene oxide) (PEO), poly(carboxylate acid) (PCA), sodium lignosulfonate (SLS), and poly(acrylic acid) (PAA). Each effective dispersant system shared very similar rheological behavior to the others when examined at the same volume fraction from its maximum petcoke loading. Triblock copolymer, Pluronic F127 (F127), was found to be the best dispersant by comparing the maximum petcoke loading for each dispersant. The yield stress was measured as a function of petcoke loading and dispersant concentration for F127, and a minimum dispersant concentration was observed. An adsorption isotherm and atomic force microscopy (AFM) images reveal that this effective dispersion of petcoke particles by F127 is due to the formation of a uniform monolayer of brushes where hydrophobic PPO domains of F127 adhere to the petcoke surface, while hydrophilic PEO tails fill the gap between petcoke particles. F127 was then compared to other Pluronics with various PEO and PPO chain lengths, and the effects of surface and dispersant hydrophilicity were examined. Finally, xanthan gum (XG) was tested as a stabilizer in combination with F127 for potential industrial application, and F127 appears to break the XG aggregates into smaller aggregates through competitive adsorption, leading to an excellent degree of dispersion but the reduced stability of petcoke slurries.