Generating ion-photon entanglement is a crucial step for scalable trapped-ion quantum networks. To avoid the crosstalk on memory qubits carrying quantum information, it is common to use a different ...ion species for ion-photon entanglement generation such that the scattered photons are far off-resonant for the memory qubits. However, such a dual-species scheme can be subject to inefficient sympathetic cooling due to the mass mismatch of the ions. Here we demonstrate a trapped-ion quantum network node in the dual-type qubit scheme where two types of qubits are encoded in the S and F hyperfine structure levels of
Yb
ions. We generate ion photon entanglement for the S-qubit in a typical timescale of hundreds of milliseconds, and verify its small crosstalk on a nearby F-qubit with coherence time above seconds. Our work demonstrates an enabling function of the dual-type qubit scheme for scalable quantum networks.
We experimentally realize a universal set of single-bit and two-bit geometric quantum gates by adiabatically controlling solid-state spins in a diamond defect. Compared with the nonadiabatic ...approach, the adiabatic scheme for geometric quantum computation offers a unique advantage of inherent robustness to parameter variations, which is explicitly demonstrated in our experiment by showing that the single-bit gates remain unchanged when the driving field amplitude varies by a factor of 2 or the detuning fluctuates in a range comparable to the inverse of the gate time. The reported adiabatic control technique and its convenient implementation offer a paradigm for achieving quantum computation through robust geometric quantum gates, which is important for quantum information systems with parameter-fluctuation noise such as those from the inhomogeneous coupling or the spectral diffusion.
We study the techno-economics of submarine systems constrained by a fixed electrical power supply. We show significant cost savings for high-capacity submarine systems using massive space-division ...multiplexing (SDM), even without assuming any savings from SDM-specific subsystem integration. Systems with about 100 parallel optical paths, e.g., ~50 fiber pairs are shown to provide minimum cost/bit, operating at reduced spectral efficiencies and deep within the linear regime. While advanced nonlinearity-optimized fibers and digital nonlinearity compensation schemes provide little to no gain in such systems, SDM integration of amplifiers and transponders is shown to be a source for significant additional cost savings. We further examine the permissible cost premium for multicore fibers in such massively parallel systems and revisit various design tradeoffs for optical amplifiers, showing that a reduced noise figure can be traded for better power conversion efficiency. We also evaluate potential gains from increasing the available electrical supply power and discuss reliability aspects of massively parallel submarine systems.
Summary
Background
Indigo naturalis and its refined formulation, Lindioil, are effective in treating psoriatic symptoms topically. Indirubin is the active ingredient in indigo naturalis.
Objectives
...To determine the efficacy and safety of different concentrations of indirubin in Lindioil ointment for treating psoriasis.
Methods
In this randomized, double‐blind trial, adult patients presenting with chronic plaque psoriasis for > 1 year and with < 20% of the body surface area (BSA) affected were randomized to apply Lindioil ointment containing 200, 100, 50 or 10 μg g−1 of indirubin twice daily for 8 weeks followed by an additional 12‐week safety/extension period. The primary end point was the mean percentage change in Psoriasis Area and Severity Index (PASI) score along with the proportion of participants achieving 75% and 90% reductions in PASI scores (PASI 75 and PASI 90, respectively) from baseline to week 8.
Results
The results from week 8 revealed that the 200 μg g−1 group had the greatest reduction in PASI score 69·2%, 95% confidence interval (CI) 55·5–82·8, followed by the 100 μg g−1 group (63·1%, 95% CI 52·8–73·5), the 10 μg g−1 group (53·4%, 95% CI 42·8–64·0) and the 50 μg g−1 group (50·3%, 95% CI 37·4–63·2), with a between‐group comparison of P = 0·0445. The group with the highest proportion of the patients achieving PASI 75 (57%, P = 0·0474) and PASI 90 (30%, P = 0·0098) was the 200 μg g−1 group. No severe treatment‐related adverse events were reported during the 20‐week evaluation.
Conclusions
An amount of 200 μg g−1 of indirubin in Lindioil ointment is the most effective concentration studied so far for treating psoriasis topically, and is safe.
What's already known about this topic?
As a result of safety concerns about the long‐term use of corticosteroids and other standard treatments, there is a growing demand for herbal treatments for psoriasis.
Indigo naturalis, a herb used in Chinese medicine, is effective for the topical treatment of psoriasis when used as a crude ointment or in its refined form, Lindioil.
What does this study add?
Indirubin is the active ingredient in indigo naturalis, and different concentrations of indirubin in indigo naturalis ointment yield different results in treating psoriasis.
This study provides evidence that 200 μg g−1 of indirubin, the highest concentration studied so far, is the most effective concentration and is safe.
Linked Comment: Sekhon and Koo. Br J Dermatol 2018; 178:21.
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Wide bandgap MAPb(I1–y Br y )3 perovskites show promising potential for application in tandem solar cells. However, unstable photovoltaic performance caused by phase segregation has been observed ...under illumination when y is above 0.2. Herein, we successfully demonstrate stabilization of the I/Br phase by partially replacing Pb2+ with Sn2+ and verify this stabilization with X-ray diffractometry and transient absorption spectroscopy. The resulting MAPb0.75Sn0.25(I1–y Br y )3 perovskite solar cells show stable photovoltaic performance under continuous illumination. Among these cells, the one based on MAPb0.75Sn0.25(I0.4Br0.6)3 perovskite shows the highest efficiency of 12.59% with a bandgap of 1.73 eV, which make it a promising wide bandgap candidate for application in tandem solar cells. The engineering of internal bonding environment by partial Sn substitution is believed to be the main reason for making MAPb0.75Sn0.25(I1–y Br y )3 perovskite less vulnerable to phase segregation during the photostriction under illumination. Therefore, this study establishes composition engineering of the metal site as a promising strategy to impart phase stability in hybrid perovskites under illumination.
Trapped ions constitute one of the most promising systems for implementing quantum computing and networking1,2. For large-scale ion-trap-based quantum computers and networks, it is critical to have ...two types of qubit: one for computation and storage, and another for auxiliary operations such as qubit detection3, sympathetic cooling4–7 and entanglement generation through photon links8,9. Although the two qubit types can be implemented using two different ion species3,10–13, this approach introduces substantial complexity into creating and controlling each qubit type14,15. Here we resolve these challenges by implementing two coherently convertible qubit types using one ion species. We encode the qubits into two pairs of clock states of the 171Yb+ ions, and achieve microsecond-level conversion rates between the two types with one-way fidelities of 99.5%. We further demonstrate that operations on one qubit type, including sympathetic laser cooling, single-qubit gates and qubit detection, have crosstalk errors less than 0.06% on the other type, which is below the best-known error threshold of ~1% for fault-tolerant quantum computing using the surface code1,16. Our work establishes the feasibility and advantages of using coherently convertible dual-type qubits with the same ion species for large-scale quantum computing and networking.Quantum computing with trapped ions requires qubits that can store and manipulate quantum information, and others that can be used for destructive incoherent operations. Different states of ytterbium-171 ions can be used to realize both qubit types
A measurement of electron antineutrino oscillation by the Daya Bay Reactor Neutrino Experiment is described in detail. Six 2.9-GWth nuclear power reactors of the Daya Bay and Ling Ao nuclear power ...facilities served as intense sources of ν¯e’s. Comparison of the ν¯e rate and energy spectrum measured by antineutrino detectors far from the nuclear reactors (∼1500–1950 m) relative to detectors near the reactors (∼350–600 m) allowed a precise measurement of ν¯e disappearance. More than 2.5 million ν¯e inverse beta-decay interactions were observed, based on the combination of 217 days of operation of six antineutrino detectors (December, 2011–July, 2012) with a subsequent 1013 days using the complete configuration of eight detectors (October, 2012–July, 2015). The ν¯e rate observed at the far detectors relative to the near detectors showed a significant deficit, R=0.949±0.002(stat)±0.002(syst). The energy dependence of ν¯e disappearance showed the distinct variation predicted by neutrino oscillation. Analysis using an approximation for the three-flavor oscillation probability yielded the flavor-mixing angle sin22θ13=0.0841±0.0027(stat)±0.0019(syst) and the effective neutrino mass-squared difference of |Δmee2|=(2.50±0.06(stat)±0.06(syst))×10−3 eV2. Analysis using the exact three-flavor probability found Δm322=(2.45±0.06(stat)±0.06(syst))×10−3 eV2 assuming the normal neutrino mass hierarchy and Δm322=(−2.56±0.06(stat)±0.06(syst))×10−3 eV2 for the inverted hierarchy.
The limitations of current anti-angiogenic therapies necessitate other targets with complimentary mechanisms. Here, we show for the first time that soluble E-cadherin (sE-cad) (an 80-kDa soluble ...form), which is highly expressed in the malignant ascites of ovarian cancer patients, is a potent inducer of angiogenesis. In addition to ectodomain shedding, we provide further evidence that sE-cad is abundantly released in the form of exosomes. Mechanistically, sE-cad-positive exosomes heterodimerize with VE-cadherin on endothelial cells and transduce a novel sequential activation of β-catenin and NFκB signaling. In vivo and clinical data prove the relevance of sE-cad-positive exosomes for malignant ascites formation and widespread peritoneal dissemination. These data advance our understanding of the molecular regulation of angiogenesis in ovarian cancer and support the therapeutic potential of targeting sE-cad. The exosomal release of sE-cad, which represents a common route for externalization in ovarian cancer, could potentially be biomarkers for diagnosis and prognosis.
Quantum computers are expected to outperform conventional computers in several important applications, from molecular simulation to search algorithms, once they can be scaled up to large ...numbers-typically millions-of quantum bits (qubits)
. For most solid-state qubit technologies-for example, those using superconducting circuits or semiconductor spins-scaling poses a considerable challenge because every additional qubit increases the heat generated, whereas the cooling power of dilution refrigerators is severely limited at their operating temperature (less than 100 millikelvin)
. Here we demonstrate the operation of a scalable silicon quantum processor unit cell comprising two qubits confined to quantum dots at about 1.5 kelvin. We achieve this by isolating the quantum dots from the electron reservoir, and then initializing and reading the qubits solely via tunnelling of electrons between the two quantum dots
. We coherently control the qubits using electrically driven spin resonance
in isotopically enriched silicon
Si, attaining single-qubit gate fidelities of 98.6 per cent and a coherence time of 2 microseconds during 'hot' operation, comparable to those of spin qubits in natural silicon at millikelvin temperatures
. Furthermore, we show that the unit cell can be operated at magnetic fields as low as 0.1 tesla, corresponding to a qubit control frequency of 3.5 gigahertz, where the qubit energy is well below the thermal energy. The unit cell constitutes the core building block of a full-scale silicon quantum computer and satisfies layout constraints required by error-correction architectures
. Our work indicates that a spin-based quantum computer could be operated at increased temperatures in a simple pumped
He system (which provides cooling power orders of magnitude higher than that of dilution refrigerators), thus potentially enabling the integration of classical control electronics with the qubit array
.
Metastasis is the predominant cause of death in breast cancer patients. Several lines of evidence have shown that microRNAs (miRs) can have an important role in cancer metastasis. Using isogenic ...pairs of low and high metastatic lines derived from a human breast cancer line, we have identified miR-149 to be a suppressor of breast cancer cell invasion and metastasis. We also identified GIT1 (G-protein-coupled receptor kinase-interacting protein 1) as a direct target of miR-149. Knockdown of GIT1 reduced migration/invasion and metastasis of highly invasive cells. Re-expression of GIT1 significantly rescued miR-149-mediated inhibition of cell migration/invasion and metastasis. Expression of miR-149 impaired fibronectin-induced focal adhesion formation and reduced phosphorylation of focal adhesion kinase and paxillin, which could be restored by re-expression of GIT1. Inhibition of GIT1 led to enhanced protein degradation of paxillin and α5β1 integrin via proteasome and lysosome pathways, respectively. Moreover, we found that GIT1 depletion in metastatic breast cancer cells greatly reduced α5β1-integrin-mediated cell adhesion to fibronectin and collagen. Low level of miR-149 and high level of GIT1 was significantly associated with advanced stages of breast cancer, as well as with lymph node metastasis. We conclude that miR-149 suppresses breast cancer cell migration/invasion and metastasis by targeting GIT1, suggesting potential applications of the miR-149-GIT1 pathway in clinical diagnosis and therapeutics.
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