Creation of memory-memory entanglement in a metropolitan quantum network.

Towards realizing the future quantum internet1,2, a pivotal milestone entails the transition from two-node proof-of-principle experiments conducted in laboratories to comprehensive multi-node set-ups on large scales. Here we report the creation of memory-memory entanglement in a multi-node quantum network over a metropolitan area. We use three independent memory nodes, each of which is equipped with an atomic ensemble quantum memory3 that has telecom conversion, together with a photonic server where detection of a single photon heralds the success of entanglement generation. The memory nodes are maximally separated apart for 12.5 kilometres. We actively stabilize the phase variance owing to fibre links and control lasers. We demonstrate concurrent entanglement generation between any two memory nodes. The memory lifetime is longer than the round-trip communication time. Our work provides a metropolitan-scale testbed for the evaluation and exploration of multi-node quantum network protocols and starts a stage of quantum internet research.

Anisotropic Piezoresistive Sensors Made with Magnetically Induced Vertically Aligned Carbon Nanotubes/Polydimethylsiloxane.

A piezoresistive material consisting of internal vertically aligned carbon nanotubes acting in concert with an external microdome structure is prepared to obtain a flexible piezoresistive sensor with high anisotropy. Here, we first obtained flexible piezoresistive composites (VCP) with anisotropic properties by inducing the vertical alignment of multiwalled carbon nanotubes in the pressure direction under a weak magnetic field of 0.6 T. Then, the composite with a microdome structure on the surface (m-VCP) was fabricated by a mold with a microstructure to further increase the anisotropy of the composite. The m-VCP microstructure was docked with VCP and placed between two layers of copper foil. With the synergistic effect of vertically aligned carbon nanotubes and the microdome structure, the sensitivity of the flexible sensor in the pressure direction was dramatically increased. In the low-strain range (0-6%), the sensitivity of m-VCP (GF = 9.208) is improved by 49% compared to m-CP and by 86% compared to VCP. The sensor has high anisotropy in the piezoresistive direction and retains good fatigue resistance under fatigue testing for 2000 cycles. This means that the sensor can be used in emerging fields such as human health monitoring, wearable electronics, and intelligent human-computer interaction.

Interplay of valley polarized dark trion and dark exciton-polaron in monolayer WSe2.

The interactions between charges and excitons involve complex many-body interactions at high densities. The exciton-polaron model has been adopted to understand the Fermi sea screening of charged excitons in monolayer transition metal dichalcogenides. The results provide good agreement with absorption measurements, which are dominated by dilute bright exciton responses. Here we investigate the Fermi sea dressing of spin-forbidden dark excitons in monolayer WSe2. With a Zeeman field, the valley-polarized dark excitons show distinct p-doping dependence in photoluminescence when the carriers reach a critical density. This density can be interpreted as the onset of strongly modified Fermi sea interactions and shifts with increasing exciton density. Through valley-selective excitation and dynamics measurements, we also infer an intervalley coupling between the dark trions and exciton-polarons mediated by the many-body interactions. Our results reveal the evolution of Fermi sea screening with increasing exciton density and the impacts of polaron-polaron interactions, which lay the foundation for understanding electronic correlations and many-body interactions in 2D systems.

Improving the quality of Napier grass silage with pyroligneous acid: Fermentation, aerobic stability, and microbial communities.

The presence of undesirable microorganisms in silage always leads to poor fermentation quality and low aerobic stability. Pyroligneous acid (PA), a by-product of biochar production, is known to have strong antimicrobial and antioxidant activities. To investigate the effects of PA on fermentation characteristics, aerobic stability, and microbial communities, Napier grass was ensiled with or without 1 and 2% PA for 30 days and then aerobically stored for 5 days. The results showed that PA application decreased (P < 0.01) the pH value, ammonia nitrogen content, and number of undesirable microorganisms (coliform bacteria, yeasts, and molds) after 30 days of ensiling and 5 days of exposure to air. The temperature of the PA-treated group was stable during the 5-day aerobic test, which did not exceed room temperature more than 2°C. The addition of PA also enhanced the relative abundance of Lactobacillus and reduced that of Klebsiella and Kosakonia. The relative abundance of Candida was higher in PA-treated silage than in untreated silage. The addition of PA decreased the relative abundance of Kodamaea and increased that of Monascus after 5 days of exposure to air. The abundances of Cladosporium and Neurospora were relatively high in 2% PA-treated NG, while these genera were note observed in the control group. These results suggested that the addition of PA could improve fermentation characteristics and aerobic stability, and alter microbial communities of silage.

Genome-Wide Identification and Expression Analysis of the Aux/IAA Gene Family of the Drumstick Tree (Moringa oleifera Lam.) Reveals Regulatory Effects on Shoot Regeneration.

Auxin plays a critical role in organogenesis in plants. The classical auxin signaling pathway holds that auxin initiates downstream signal transduction by degrading Aux/IAA transcription repressors that interact with ARF transcription factors. In this study, 23 MoIAA genes were identified in the drumstick tree genome. All MoIAA genes were located within five subfamilies based on phylogenetic evolution analysis; the gene characteristics and promoter cis-elements were also analyzed. The protein interaction network between the MoIAAs with MoARFs was complex. The MoIAA gene family responded positively to NAA treatment, exhibiting different patterns and degrees, notably for MoIAA1, MoIAA7 and MoIAA13. The three genes expressed and functioned in the nucleus; only the intact encoding protein of MoIAA13 exhibited transcriptional activation activity. The shoot regeneration capacity in the 35S::MoIAA13-OE transgenic line was considerably lower than in the wild type. These results establish a foundation for further research on MoIAA gene function and provide useful information for improved tissue culture efficiency and molecular breeding of M. oleifera.

Postselected Entanglement between Two Atomic Ensembles Separated by 12.5 km.

Quantum internet gives the promise of getting all quantum resources connected, and it will enable applications far beyond a localized scenario. A prototype is a network of quantum memories that are entangled and well separated. In this Letter, we report the establishment of postselected entanglement between two atomic quantum memories physically separated by 12.5 km directly. We create atom-photon entanglement in one node and send the photon to a second node for storage via electromagnetically induced transparency. We harness low-loss transmission through a field-deployed fiber of 20.5 km by making use of frequency down-conversion and up-conversion. The final memory-memory entanglement is verified to have a fidelity of 90% via retrieving to photons. Our experiment makes a significant step forward toward the realization of a practical metropolitan-scale quantum network.

Helping Older Residents Remain in Subsidized Housing: Predictive Validity of the Live Well at Home-Rapid Screen (LWAH-RS) in a Real-World Application.

Common Bond Communities (CBC) is a nonprofit organization that provides housing for low-income individuals and families. CBC utilized the Live Well at Home-Rapid Screen (LWAH-RS) to identify the risks for nursing home admission or assisted living entry among housing residents aged 60 or above. Drawing data from 842 assessments, we studied how well the LWAH-RS predicted moves to nursing homes or assisted living settings. Cox regression models showed that the LWAH-RS did predict which residents would move to a care setting. Every 1-point higher in the LWAH-RS assessment score was associated with a 38% higher risk of moving to a higher-level care facility due to health issues. Given this demonstrated predictive validity in a real-world setting, we suggest more systematic approaches for housing practitioners to combat low assessment completion rates and unclear protocols for actions based on the scores.

Global Transcriptomic Analysis Reveals Differentially Expressed Genes Involved in Embryogenic Callus Induction in Drumstick (Moringa oleifera Lam.).

The plant embryogenic callus (EC) is an irregular embryogenic cell mass with strong regenerative ability that can be used for propagation and genetic transformation. However, difficulties with EC induction have hindered the breeding of drumstick, a tree with diverse potential commercial uses. In this study, three drumstick EC cDNA libraries were sequenced using an Illumina NovaSeq 6000 system. A total of 7191 differentially expressed genes (DEGs) for embryogenic callus development were identified, of which 2325 were mapped to the KEGG database, with the categories of plant hormone signal transduction and Plant-pathogen interaction being well-represented. The results obtained suggest that auxin and cytokinin metabolism and several embryogenesis-labeled genes are involved in embryogenic callus induction. Additionally, 589 transcription factors from 20 different families were differentially expressed during EC formation. The differential expression of 16 unigenes related to auxin signaling pathways was validated experimentally by quantitative real time PCR (qRT-PCR) using samples representing three sequential developmental stages of drumstick EC, supporting their apparent involvement in drumstick EC formation. Our study provides valuable information about the molecular mechanism of EC formation and has revealed new genes involved in this process.

Improved Spatial Resolution Achieved by Chromatic Intensity Interferometry.

Interferometers are widely used in imaging technologies to achieve enhanced spatial resolution, but require that the incoming photons be indistinguishable. In previous work, we built and analyzed color erasure detectors, which expand the scope of intensity interferometry to accommodate sources of different colors. Here we demonstrate experimentally how color erasure detectors can achieve improved spatial resolution in an imaging task, well beyond the diffraction limit. Utilizing two 10.9-mm-aperture telescopes and a 0.8 m baseline, we measure the distance between a 1063.6 and a 1064.4 nm source separated by 4.2 mm at a distance of 1.43 km, which surpasses the diffraction limit of a single telescope by about 40 times. Moreover, chromatic intensity interferometry allows us to recover the phase of the Fourier transform of the imaged objects-a quantity that is, in the presence of modest noise, inaccessible to conventional intensity interferometry.

Non-Line-of-Sight Imaging with Picosecond Temporal Resolution.

Non-line-of-sight (NLOS) imaging enables monitoring around corners and is promising for diverse applications. The resolution of transient NLOS imaging is limited to a centimeter scale, mainly by the temporal resolution of the detectors. Here, we construct an up-conversion single-photon detector with a high temporal resolution of ∼1.4 ps and a low noise count rate of 5 counts per second (cps). Notably, the detector operates at room temperature, near-infrared wavelength. Using this detector, we demonstrate high-resolution and low-noise NLOS imaging. Our system can provide a 180 µm axial resolution and a 2 mm lateral resolution, which is more than 1 order of magnitude better than that in previous experiments. These results open avenues for high-resolution NLOS imaging techniques in relevant applications.

Effects of Gallic Acid on Fermentation Parameters, Protein Fraction, and Bacterial Community of Whole Plant Soybean Silage.

Whole plant soybean (WPS) is a kind of legume resource with characteristics of high nutrition, large biomass, and wide distribution. In the present study, we have investigated the feasibility and effects of gallic acid (GA) on WPS silage quality, nitrogen distribution, tannin content, and bacterial community. The 0.5 and 1% (fresh matter basis) GA were added into WPS for dynamic ensiling (days 3, 7, 14, and 30, respectively). The results showed that the WPS silage with GA addition significantly decreased pH value (6.16-5.38 at ensiling day 30), coliform bacteria count and butyric acid (65.3-62.0 g/kg dry matter at ensiling day 30), and amino nitrogen contents (259-88.2 g/kg total nitrogen at ensiling day 30) and promoted lactic acid (9.62-31.5 g/kg dry matter at ensiling day 30), acetic acid (24.1-85.6 g/kg dry matter at ensiling day 30), and tannin (total phenol and hydrolyzable tannin) contents. Additionally, the GA addition also contributed to the change of bacterial community, where Firmicutes and Lactobacillus were most abundant on phylum and genus levels, respectively. The above results suggested that GA additive applied in WPS silage was an effective strategy to protect nutrition and improve fermentation quality, and the 1% GA addition showed a better effect.

Altering bacterial community: A possible way of lactic acid bacteria inoculants reducing CO2 production and nutrient loss during fermentation.

CO2 production during ensiling is a source of greenhouse gases emissions and a cause of nutrient loss of silage. To investigate the influence of additives on CO2 production and relevant bacterial communities, stylo and rice straw were ensiled with sucrose and Lactobacillus plantarum (LP). After 30 days fermentation, LP reduced CO2 production (from 66.2 to 0 mL/100 g fresh matter in stylo, from 83.7 to 16.6 mL/100 g fresh matter in rice straw) and weight loss (from 2.71 to 1.72% in stylo, from 2.75 to 2.40% in rice straw). CO2 production was positively correlated (P < 0.05) with Lactococcus (0.99), Leuconostoc (0.55), Lachnoclostridium (0.45), Prevotella (0.23) and was negatively correlated (P < 0.05) with Serratia (-0.66), Sphingobacterium (-0.58), Pediococcus (-0.36). LP decreased the relative abundance of genera positively correlated with CO2 production and increased that of genera negatively correlated. In conclusion, LP could reduce CO2 production by altering bacterial community during ensiling.

Mentoring Social Work PhD Students to Help Re-imagine Long-term Care.

This commentary explores the role of mentoring in creating the next generation of gerontological social work scholars through examining the mentoring of Dr. Rosalie Kane. We review how Rosalie exemplified some of key characteristics of an exceptional academic mentor based on communications with many of her former mentees, provide an account of her last formal mentoring relationship with a graduate student, and discuss how Rosalie's mentorship related to her hopes for re-imagining long-term care and the future of gerontological social work.

Chromatic interferometry with small frequency differences.

By developing a 'two-crystal' method for color erasure, we can broaden the scope of chromatic interferometry to include optical photons whose frequency difference falls outside of the 400 nm to 4500 nm wavelength range, which is the passband of a PPLN crystal. We demonstrate this possibility experimentally, by observing interference patterns between sources at 1064.4 nm and 1063.6 nm, corresponding to a frequency difference of about 200 GHz.

Optimizing up-conversion single-photon detectors for quantum key distribution.

High-performance single-photon detectors (SPDs) at 1550-nm band are critical for fiber-based quantum communications. Among many types of SPDs, the up-conversion SPDs based on periodically poled lithium niobate waveguides are of great interest. Combined with a strong pump laser, the telecom single-photons are converted into short wavelength ones and detected by silicon-based SPDs. However, due to the difficulty of precise controlling waveguide profile, the direct coupling between a single-mode fiber and the waveguide is not efficient. Here by utilizing fiber taper with proper diameter, optimal mode-matching is achieved and coupling efficiency up to 93% is measured. With an optimized design, a system detection efficiency of 36% and noise counting rate of 90 cps are realized. The maximum detection efficiency is characterized as 40% with a noise counting rate of 200 cps. Numerical simulation results indicate that our device can significantly improve the performance of QKD and extend the communication distance longer than 200 km.

Entanglement of two quantum memories via fibres over dozens of kilometres.

A quantum internet that connects remote quantum processors1,2 should enable a number of revolutionary applications such as distributed quantum computing. Its realization will rely on entanglement of remote quantum memories over long distances. Despite enormous progress3-12, at present the maximal physical separation achieved between two nodes is 1.3 kilometres10, and challenges for longer distances remain. Here we demonstrate entanglement of two atomic ensembles in one laboratory via photon transmission through city-scale optical fibres. The atomic ensembles function as quantum memories that store quantum states. We use cavity enhancement to efficiently create atom-photon entanglement13-15 and we use quantum frequency conversion16 to shift the atomic wavelength to telecommunications wavelengths. We realize entanglement over 22 kilometres of field-deployed fibres via two-photon interference17,18 and entanglement over 50 kilometres of coiled fibres via single-photon interference19. Our experiment could be extended to nodes physically separated by similar distances, which would thus form a functional segment of the atomic quantum network, paving the way towards establishing atomic entanglement over many nodes and over much longer distances.

Color Erasure Detectors Enable Chromatic Interferometry.

By engineering and manipulating quantum entanglement between incoming photons and experimental apparatus, we construct single-photon detectors which cannot distinguish between photons of very different wavelengths. These color-erasure detectors enable a new kind of intensity interferometry, with potential applications in microscopy and astronomy. We demonstrate chromatic interferometry experimentally, observing robust interference using both coherent and incoherent photon sources.

1.064-µm-band up-conversion single-photon detector.

Based on the technique of periodically poled lithium niobate waveguide, up-conversion single-photon detection at 1.064-µm is demonstrated. We have achieved a system photon detection efficiency of 32.5% with a very low noise count rate of 45 counts per second by pumping with a 1.55-µm-band single frequency laser using the long-wavelength pumping technique and exploiting volume Bragg grating as a narrow band filter. Replacing the volume Bragg grating with a combination of adequate dielectric filters, a detection efficiency of up to 38% with a noise count rate of 700 counts per second is achieved, making the overall system stable and practical. The up-conversion single-photon detector operating at 1.064 µm can be a promising robust counter and find usage in many fields.

Integrated four-channel all-fiber up-conversion single-photon-detector with adjustable efficiency and dark count.

Up-conversion single photon detector (UCSPD) has been widely used in many research fields including quantum key distribution, lidar, optical time domain reflectrometry, and deep space communication. For the first time in laboratory, we have developed an integrated four-channel all-fiber UCSPD which can work in both free-running and gate modes. This compact module can satisfy different experimental demands with adjustable detection efficiency and dark count. We have characterized the key parameters of the UCSPD system.

GPIbα reflects the development and progress of the patients with severe preeclampsia.

UNLABELLED: Preeclampsia (PE) is a pregnancy-specific syndrome that occurs in a previously normotensive woman. Some data suggested that the activation parameters of platelets in preeclampsia. The aim of this study is to determine whether the levels of GPIbα and GPIIb for patients with preeclampsia were enhanced after cesarean section. In this study, detecting levels of GPIbα and GPIIb by flow cytometry (FCM). The venous blood of 48 severe preeclampsia women, 16 mild preeclampsia and 22 normotensive women, were collected before operation and 72 hours after the operation. Blood samples were obtained also from 20 non-pregnant women. RESULTS: The level of GPIbα of the normotensive pregnancy was lower than the control group, but there was no significance (P > 0.05). The level of GPIbα of the severe preeclampsia group was much lower than other groups (P < 0.01). In the severe preeclampsia group, the level of GPIbα of postoperative patients was higher than preoperative patients (P < 0.01). There was no significance of GPIIb levels between each group (P > 0.05). In conclusion, GPIbα was an important index of reflecting the change of severe preeclampsia. Detecting the levels of GPIbα plays an important role in observing the development of this disease and guiding clinical treatment.