Quantum nonlinear effect in a dissipatively coupled optomechanical system.

A full-quantum approach is used to study the quantum nonlinear properties of a compound Michelson-Sagnac interferometer optomechanical system. By deriving the effective Hamiltonian, we find that the reduced system exhibits a Kerr nonlinear term with a complex coefficient, entirely induced by the dissipative and dispersive couplings. Unexpectedly, the nonlinearities resulting from the dissipative coupling possess non-Hermitian Hamiltonian-like properties preserving the quantum nature of the dispersive coupling beyond the traditional system dissipation. This protective mechanism allows the system to exhibit strong quantum nonlinear effects when the detuning (the compound cavity detuning Δc and the auxiliary cavity detuning Δe) and the tunneling coupling strength (J) of two cavities satisfy the relation J2 = ΔcΔe. Moreover, the additive effects of dispersive and dissipative couplings can produce strong anti-bunching effects, which exist in both strong and weak coupling conditions. Our work may provide a new way to study and produce strong quantum nonlinear effects in dissipatively coupled optomechanical systems.

Relationships between the coronary fat attenuation index for patients with heart-related disease measured automatically on coronary computed tomography angiography and coronary adverse events and degree of coronary stenosis.

Background: Pericoronary artery coronary tissue (PACT) is a type of epicardial fat that can reflect the state of the coronary artery (inflammation, etc.). However, it cannot be reasonably and efficiently utilized in routine computed tomography (CT) examination. The aim of this study was to use artificial intelligence (AI) software to analyze coronary computed tomography angiography (CCTA) and measure the coronary perivascular fat attenuation index (FAI) of patients. The relationship between FAI and the occurrence of coronary adverse events and the degree of coronary stenosis were further analyzed. Methods: This study involved patients who experienced CCTA in West China Hospital, Sichuan University, from January 2012 to December 2012. These patients were followed up to 2020 and classified according to the occurrence of coronary adverse events and the degree of stenosis of the lumen. For all patients, AI software was used to analyze the CCTA images of patients, and the FAI of 3 coronary arteries, the left anterior descending artery (LAD), the left circumflex artery (LCX), and the right coronary artery (RCA), was measured. Moreover, the relationship between FAI and patients with different degrees of coronary stenosis and adverse coronary events was determined. Results: Comparisons between any 2 groups showed that the differences in the FAI among the 4 groups for the LAD were significant (all P values <0.05). There were no significant differences between the group with less-than-moderate stenosis (Mb) without adverse events and the group with moderate-or-above stenosis (M) with no adverse events for the LCX (P>0.05). For the remaining groups, FAI values exhibited statistically significant differences (P<0.05). According to the degree of lumen stenosis, the patients were divided into groups according to LAD, LCX, and RCA and the sum of the 3 vessels. There were significant differences in coronary FAI among the groups with different degrees of lumen stenosis for the sum of the 3 vessels, the LAD, and the LCX (P<0.05). Conclusions: FAI can reflect the state of the coronary artery, which is related to inflammation of the coronary lumen. Moreover, there is a relationship between FAI and the degree of stenosis in the coronary lumen: the narrower the coronary lumen is, the higher the FAI around the lumen.

Clinical characterization of EFHD2 (swiprosin-1) in Glioma-associated macrophages and its role in regulation of immunosuppression.

Glioblastoma has been extensively studied due to its high mortality and short survival. The evolution mechanism of tumor-associated macrophages (TAMs) to Glioma-associated microglia and macrophages (GAMs) in the tumor microenvironment (TME) remains to be elucidated. The tumor cell-to-cell interaction patterns have not been well defined yet. The EF-Hand Domain Family Member D2 (EFHD2) has been reported to be differentially expressed as an immunomodulatory molecule in a variety of cancers. But large-scale clinical data from multiple ethnic communities have not been used to investigate the role of EFHD2 in glioma. RNA-seq data from 313 or 657 glioma patients from the Chinese Glioma Genome Atlas (CGGA) database and 603 glioma patients from the Cancer Genome Atlas (TCGA) database were analyzed retrospectively. Cell localization was performed using single-cell sequencing data from the CGGA database and the GSE131928 dataset. Mouse glioma cell lines and primary macrophages isolated from Efhd2 knockout mice were co-cultured to validate the immunomodulatory effects of EFHD2 on macrophages and the remodeling of TME of glioblastoma. EFHD2 is enriched in high-grade gliomas, isocitrate dehydrogenase wild-type, and 1p/19q non-co-deficient gliomas. It is a potential biomarker of glioma-proneuronal subtypes and an independent prognostic factor for overall survival in patients with malignant glioblastoma. EFHD2 regulates the monocyte-macrophage system function and positively correlates with immunosuppressive checkpoints. Further experimental data demonstrates that Efhd2 influences the polarization state of GAMs and inhibits the secretion of TGF-ß1. In vitro experiments have revealed that macrophages lacking Efhd2 suppress the vitality of two glioma cell lines and decelerate the growth of glioma xenografts. In conclusion, EFHD2 promises to be a key target for TME-related immunotherapy.

Optomechanical noise suppression with the optimal squeezing process.

Quantum squeezing-assisted noise suppression is a promising field with wide applications. However, the limit of noise suppression induced by squeezing is still unknown. This paper discusses this issue by studying weak signal detection in an optomechanical system. By solving the system dynamics in the frequency domain, we analyze the output spectrum of the optical signal. The results show that the intensity of the noise depends on many factors, including the degree or direction of squeezing and the choice of the detection scheme. To measure the effectiveness of squeezing and to obtain the optimal squeezing value for a given set of parameters, we define an optimization factor. With the help of this definition, we find the optimal noise suppression scheme, which can only be achieved when the detection direction exactly matches the squeezing direction. The latter is not easy to adjust as it is susceptible to changes in dynamic evolution and sensitive to parameters. In addition, we find that the additional noise reaches a minimum when the cavity (mechanical) dissipation κ(γ) satisfies the relation κ = Nγ, which can be understood as the restrictive relationship between the two dissipation channels induced by the uncertainty relation. Furthermore, by taking into account the noise source of our system, we can realize high-level noise suppression without reducing the input signal, which means that the signal-to-noise ratio can be further improved.

Unidirectional amplification in optomechanical system coupling with a structured bath.

Nonreciprocity plays an indispensable role in quantum information transmission. We theoretically study the unidirectional amplification in the non-Markovian regime, in which a nanosphere surrounded by a structured bath is trapped in a single (dual)-mode cavity. The global mechanical response function of the nanosphere is markedly altered by the non-Markovian structured bath through shifting the effective frequency and magnifying the response function. Consequently, when there is a small difference in the transmission rate within the regime of Markovian, the unidirectional amplification is achieved in the super-Ohmic spectral environment. In the double-optomechanical coupling system, the phase difference between two optomechanical couplings can reverse the transmission direction. Meanwhile, the non-Markovian bath still can amplify the signal because of the XX-type coupling between nanosphere and its bath.

Case report: A double pathogenic mutation in a patient with late-onset MELAS/PEO overlap syndrome.

Mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) and progressive external ophthalmoplegia (PEO) are established phenotypes of mitochondrial disorders. They are maternally-inherited, multisystem disorder that is characterized by variable clinical, biochemical, and imaging features. We described the clinical and genetic features of a Chinese patient with late-onset MELAS/PEO overlap syndrome, which has rarely been reported. The patient was a 48-year-old woman who presented with recurrent ischemic strokes associated with characteristic brain imaging and bilateral ptosis. We assessed her clinical characteristics and performed mutation analyses. The main manifestations of the patient were stroke-like episodes and seizures. A laboratory examination revealed an increased level of plasma lactic acid and a brain MRI showed multiple lesions in the cortex. A muscle biopsy demonstrated ragged red fibers. Genetic analysis from a muscle sample identified two mutations: TL1 m.3243A>G and POLG c.3560C>T, with mutation loads of 83 and 43%, respectively. This suggested that mitochondrial disorders are associated with various clinical presentations and an overlap between the syndromes and whole exome sequencing is important, as patients may carry multiple mutations.

Warming Shapes nirS- and nosZ-Type Denitrifier Communities and Stimulates N2O Emission in Acidic Paddy Soil.

Warming strongly stimulates soil nitrous oxide (N2O) emission, contributing to the global warming trend. Submerged paddy soils exhibit huge N2O emission potential; however, the N2O emission pathway and underlying mechanisms for warming are not clearly understood. We conducted an incubation experiment using 15N to investigate the dynamics of N2O emission at controlled temperatures (5, 15, 25, and 35°C) in 125% water-filled pore space. The community structures of nitrifiers and denitrifiers were determined via high-throughput sequencing of functional genes. Our results showed that elevated temperature sharply enhanced soil N2O emission from submerged paddy soil. Denitrification was the main contributor, accounting for more than 90% of total N2O emission at all treatment temperatures. N2O flux was coordinatively regulated by nirK-, nirS-, and nosZ-containing denitrifiers but not ammonia-oxidizing archaea or ammonia-oxidizing bacteria. The nirS-containing denitrifiers were more sensitive to temperature shifts, especially at a lower temperature range (5 to 25°C), and showed a stronger correlation with N2O flux than that of nirK-containing denitrifiers. In contrast, nosZ-containing denitrifiers exhibited substantial variation at higher temperatures (15 to 35°C), thereby playing an important role in N2O consumption. Certain taxa of nirS- and nosZ-containing denitrifiers regulated N2O flux, including nirS-containing denitrifiers affiliated with Rhodanobacter and Cupriavidus as well as nosZ-containing denitrifiers affiliated with Azoarcus and Azospirillum. Together, these findings suggest that elevated temperature can significantly increase N2O emission from denitrification in submerged paddy soils by shifting the overall community structures and enriching some indigenous taxa of nirS- and nosZ-containing denitrifiers. IMPORTANCE The interdependence between global warming and greenhouse gas N2O has always been the hot spot. However, information on factors contributing to N2O and temperature-dependent community structure changes is scarce. This study demonstrated high-temperature-induced N2O emission from submerged paddy soils, mainly via stimulating denitrification. Further, we speculate that key functional denitrifiers drive N2O emission. This study showed that denitrifiers were more sensitive to temperature rise than nitrifiers, and the temperature sensitivity differed among denitrifier communities. N2O-consuming denitrifiers (nosZ-containing denitrifiers) were more sensitive at a higher temperature range than N2O-producing denitrifiers (nirS-containing denitrifiers). This study's findings help predict N2O fluxes under different degrees of warming and develop strategies to mitigate N2O emissions from paddy fields based on microbial community regulation.

[Differential Responses of Rhizospheric nirK- and nirS-type Denitrifier Communities to Different Phosphorus Levels in Paddy Soil].

Phosphorus is an essential life element, which can affect the activities and functions of denitrifiers. Both nirK and nirS genes can code nitrite reductase; however, it remains unclear whether nirK- and nirS-containing denitrifers respond differentially to changes in the availability of phosphorus in paddy soil. In this study, P-deficient paddy soil was used to grow rice plants. Three phosphorus levels established by applying P fertilizer at a rate of 0 mg·kg-1 (CK), 15 mg·kg-1 (P1), and 30 mg·kg-1(P2), respectively. The abundance and community structure of nirK- and nirS- containing denitrifers were determined using quantitative PCR and high-throughput sequencing techniques. Results indicated that nirK- and nirS-containing communities responded differentially to changes in the P levels. The nirS-containing communities are more sensitive to the changes in P in both rhizosphere and bulk soil samples. In addition, the abundance of nirS genes was 2-3 times higher in the P2 treatment than in the CK treatment. Furthermore, the nirS community structure is also clearly differed from the CK treatment. However, P addition only induced partial modification of the community structure and abundance of nirK-containing denitrifiers. Moreover, compared to the bulk soil with each phosphorus level, the nirS community structure in the rhizosphere soil changed significantly; however, only the P2 treatment induced significant increases in the abundance of the nirS gene. In contrast, no significant differences in the abundance and composition of nirK-containing denitrifers were detected between rhizosphere and bulk soils under different phosphorus levels. Collectively, application of phosphate fertilizer in P-deficient paddy soil could significantly increase the abundance of nirK- and nirS-containing denitrifiers, changing their community structures, with nirS-type showing a greater sensitivity than nirK-type denitrifiers. In comparison, the denitrifying communities in the rhizosphere were more sensitive to variable P levels than that in the bulk soil. Compared to bulk soils, rice growth shifted the community structure of nirS- and nirK-containing denitrifiers in rhizosphere soils at each level of P, but failed to induce significant changes in their abundance (except for P2) that could cause a significant increase in nirS abundance. These results could provide a theoretical basis for exploring the effects of fertilization on soil denitrification.

Generation of entangled Schrödinger cat state of two macroscopic mirrors.

We propose a scheme to generate the macroscopic entangled Schrödinger cat state of two mechanical resonators in a hybrid optomechanical system by introducing modulated photon-hopping interaction between two cavities. We show that the obtained entangled cat state possesses large average phonon number and the two base vectors of which are nearly orthogonal, thus causing the high degree of entanglement. To justify the robust of the scheme, the dissipation of the system and the noise from the environment are considered. It shows that the high fidelity between the obtained state and the target state can be achieved in the presence of dissipation and thermal noise within our parameter regions, which suggests that our state-generation proposal is feasible.

[Variation of community structure and function of rhizospheric denitrifiers at tillering and booting stages of rice]. / æ°´ç¨»åˆ†è˜–æœŸå’Œå­•ç©—æœŸæ ¹é™ åç¡åŒ–èŒç¾¤è½ç»“æž„åŠåŠŸèƒ½å˜åŒ–.

We investigated the variation of denitrifying communities in rice rhizosphere at tillering and booting stages in comparison with bulk soils with a pot experiment. The techniques of quantitative polymerase chain reaction (qPCR) and terminal restriction fragment length polymorphism (T-RFLP) were used to measure the abundance and community composition of denitrifiers (narG and nosZ), respectively. The results showed that the potential denitrification activity in the rhizosphere at tillering stage was significantly lower than bulk soils. No significant difference was detected between the rhizosphere and bulk soils at booting stage. The abundance of both narG- and nosZ-containing denitrifying bacteria was significantly higher in rhizosphere than in bulk soils at both tillering and booting stages. In comparison with narG-containing community, community composition and diversity of nosZ-containing bacteria were more sensitive to rice growth. In conclusion, the exudates of rice could induce significantly more denitrifying bacteria in rhizosphere, whose denitrifying activities were related to growth stage of rice. At the period with strong growth, the secretion of roots showed clear restriction to the functions of rhizospheric denitrifiers compared to booting stage.

Multi-path photon-phonon converter in optomechanical system at single-quantum level.

Based on photon-phonon nonlinear interaction, a scheme of controllable photon-phonon converters is proposed at single-quantum level in a composed quadratically coupled optomechanical system. With the assistance of the mechanical oscillator, the Kerr nonlinear effect between photon and phonon is enhanced so that the single-photon state can be converted into the phonon state with high fidelity even under the current experimental condition that the single-photon coupling rate is much smaller than mechanical frequency (g ≪ ωm). The state transfer protocols and their transfer fidelity are discussed analytically and numerically. A multi-path photon-phonon converter is designed by combining the optomechanical system with low frequency resonators, which can be controlled by experimentally adjustable parameters. This work provides us a potential platform for quantum state transfer and quantum information.

Chiral Primary Amine Catalyzed Asymmetric α-Benzylation with In Situ Generated ortho-Quinone Methides.

A dual activation strategy integrating primary amine catalysis and Lewis base activation has been developed for an asymmetric α-benzylation reaction. Enamines derived from ß-ketocarbonyls could react effectively with in situ generated ortho-quinone methides under Lewis base activation in asymmetric α-benzylation of ß-ketocarbonyls and α-branched aldehydes. The approach enables the creation of acyclic all-carbon quaternary stereocenters with excellent enantioselectivities and good activity.

Single-photon multi-ports router based on the coupled cavity optomechanical system.

A scheme of single-photon multi-port router is put forward by coupling two optomechanical cavities with waveguides. It is shown that the coupled two optomechanical cavities can exhibit photon blockade effect, which is generated from interference of three mode interaction. A single-photon travel along the system is calculated. The results show that the single photon can be controlled in the multi-port system because of the radiation pressure, which should be useful for constructing quantum network.

Preservation Macroscopic Entanglement of Optomechanical Systems in non-Markovian Environment.

We investigate dynamics of an optomechanical system under the non-Markovian environment. In the weak optomechanical single-photon coupling regime, we provide an analytical approach fully taking into account the non-Markovian memory effects. When the cavity-bath coupling strength crosses a certain threshold, an oscillating memory state for the classical cavity field is formed. Due to the existence of the non-decay optical bound state, a nonequilibrium optomechanical thermal entanglement is preserved even without external driving laser. Our results provide a potential usage to generate and protect entanglement via non-Markovian environment.

Direct enantiospecific substitution of primary α-aminoalkylferrocenes via Lewis acid-catalyzed C-N bond cleavage.

Highly enantioenriched primary α-aminoalkylferrocenes were found to undergo zinc chloride-catalyzed substitution with various carbon, nitrogen, and sulfur nucleophiles in an enantiospecific fashion through C-N bond cleavage. The reaction tolerates air and moisture and exhibits high atom-economy by releasing ammonia as the sole byproduct.