Sideband cooling of a trapped ion in strong sideband coupling regime.

Conventional theoretical studies on the ground-state laser cooling of a trapped ion have mostly focused on the weak sideband coupling (WSC) regime, where the cooling rate is inverse proportional to the linewidth of the excited state. In a recent work [New J. Phys.23, 023018 (2021)10.1088/1367-2630/abe273], we proposed a theoretical framework to study the ground state cooling of a trapped ion in the strong sideband coupling (SSC) regime, under the assumption of a vanishing carrier transition. Here we extend this analysis to more general situations with nonvanishing carrier transitions, where we show that by properly tuning the coupling lasers a cooling rate proportional to the linewidth can be achieved. Our theoretical predictions closely agree with the corresponding exact solutions in the SSC regime, which provide an important theoretical guidance for sideband cooling experiments.

Tunable multi-channel inverse optomechanically induced transparency and its applications.

In contrast to the optomechanically induced transparency (OMIT) defined conventionally, the inverse OMIT behaves as coherent absorption of the input lights in the optomechanical systems. We characterize a feasible inverse OMIT in a multi-channel fashion with a double-sided optomechanical cavity system coupled to a nearby charged nanomechanical resonator via Coulomb interaction, where two counter-propagating probe lights can be absorbed via one of the channels or even via three channels simultaneously with the assistance of a strong pump light. Under realistic conditions, we demonstrate the experimental feasibility of our model by considering two slightly different nanomechanical resonators and the possibility of detecting the energy dissipation of the system. In particular, we find that our model turns to be a unilateral inverse OMIT once the two probe lights are different with a relative phase, and in this case the relative phase can be detected precisely.

Ground state cooling of an optomechanical resonator assisted by a Λ-type atom.

We propose a ground state cooling scheme for an optomechanical resonator based on the system of one Λ-type three-level atom trapped in an optomechanical cavity. This cooling scheme works in a single-photon coupling, and strong atom-cavity coupling regimes. By investigating the cooling dynamics, we find that there is an EIT-like quantum coherent effect in this system which can suppress the undesired transitions for heating. Moreover, our study shows that the final average phonon number of the optomechanical resonator can be smaller than the one based on the sideband cooling. Furthermore, the ground state cooling of the resonator can still be achieved after thermal fluctuations included. In addition, in comparison with previous cooling methods, there are fewer limitations on the decay rates of both the cavity and the atom in this scheme. As a result, this scheme is very suitable to realize the ground cooling of an optomechanical resonator in the experiment.

Decreased circulating microRNA-223 level predicts high on-treatment platelet reactivity in patients with troponin-negative non-ST elevation acute coronary syndrome.

To investigate the relationship between circulating microRNA 223 (miR-223) levels and clopidogrel responsiveness in patients with coronary heart disease. A total of 62 consecutive patients with troponin-negative non-ST elevation acute coronary syndrome (NSTE-ACS) scheduled for elective percutaneous coronary intervention were enrolled. The plasma circulating miR-223 levels were quantified by real-time PCR, and platelet reactivity was determined by platelet reactivity index (PRI), measured by vasodilator-stimulated phosphoprotein (VASP) phosphorylation flow cytometry after 300 mg (for at least 24 h) or 75 mg clopidogel (for at least 5 days) plus aspirin treatment. All subjects were dichotomized according to PRI median (normal-responders: PRI ≤ 56.3%, n = 31 and low-responders: PRI > 56.3%, n = 31). Compared with normal-responders, circulating miR-223 level was significantly decreased in low-responders (P = 0.007). In addition, miR-223 level was statistically correlated with PRI (Spearman r = -0.379, P = 0.002). Stepwise binary logistic regression analysis revealed that among factors that potentially influence platelet reactivity (CYP2C19*2/*3 loss-of-function genotypes, use of calcium channel blockers/proton-pump inhibitors, age, diabetes and smoking), decreased circulating miR-223 level was the only independent predictor for the presence of PRI-determined lower responders (OR 0.111, 95% CI 0.018-0.692, P = 0.019). Our data suggest that circulating miR-223 may serve as a novel biomarker for assessment of clopidogrel responsiveness in troponin-negative NSTE-ACS patients.

Hedysarumqilianshanense sp. nov. (Fabaceae, Hedysareae), a new species from the Qilianshan Mountains in Gansu, China.

Hedysarumqilianshanensesp. nov. (Fabaceae, Hedysareae) is described and illustrated from the Qilianshan Mountains in Gansu, China. This new species is similar to H.przewalskii, but can be distinguished by its corolla being light purple to purple, standard 15-19 mm long, wings 14-16 mm long, keels 16-19 mm long, and the ovary and legume being glabrous. The new species can be easily distinguished from H.neglectum Ledeb. by its bract being shorter than the pedicel, and the ovary and legume being glabrous. Phylogenetic tree based on the nuclear ITS and ETS sequences shows that H.qilianshanense is sister to H.przewalskii, while the tree based on the plastid psbA-trnH, trnC-petN, trnL-F, trnS-G and petN-psbM sequences shows H.qilianshanense as sister to a clade consisting of H.hedysaroides, H.inundatum, H.americanum and H.neglectum. The new species is a diploid with the chromosome number 2n = 14. Based on morphological, phylogenetic and karyotypic evidence, the new species may originate from an ancient homoploid hybrid speciation event.

Chiral quantum heating and cooling with an optically controlled ion.

Quantum heat engines and refrigerators are open quantum systems, whose dynamics can be well understood using a non-Hermitian formalism. A prominent feature of non-Hermiticity is the existence of exceptional points (EPs), which has no counterpart in closed quantum systems. It has been shown in classical systems that dynamical encirclement in the vicinity of an EP, whether the loop includes the EP or not, could lead to chiral mode conversion. Here, we show that this is valid also for quantum systems when dynamical encircling is performed in the vicinity of their Liouvillian EPs (LEPs), which include the effects of quantum jumps and associated noise-an important quantum feature not present in previous works. We demonstrate, using a Paul-trapped ultracold ion, the first chiral quantum heating and refrigeration by dynamically encircling a closed loop in the vicinity of an LEP. We witness the cycling direction to be associated with the chirality and heat release (absorption) of the quantum heat engine (quantum refrigerator). Our experiments have revealed that not only the adiabaticity breakdown but also the Landau-Zener-Stückelberg process play an essential role during dynamic encircling, resulting in chiral thermodynamic cycles. Our observations contribute to further understanding of chiral and topological features in non-Hermitian systems and pave a way to exploring the relation between chirality and quantum thermodynamics.

Fast optical cooling of nanomechanical cantilever with the dynamical Zeeman effect.

We propose an efficient optical electromagnetically induced transparency (EIT) cooling scheme for a cantilever with a nitrogen-vacancy center attached in a non-uniform magnetic field using dynamical Zeeman effect. In our scheme, the Zeeman effect combined with the quantum interference effect enhances the desired cooling transition and suppresses the undesired heating transitions. As a result, the cantilever can be cooled down to nearly the vibrational ground state under realistic experimental conditions within a short time. This efficient optical EIT cooling scheme can be reduced to the typical EIT cooling scheme under special conditions.

[Study of automatic marine oil spills detection using imaging spectroscopy].

To reduce artificial auxiliary works in oil spills detection process, an automatic oil spill detection method based on adaptive matched filter is presented. Firstly, the characteristics of reflectance spectral signature of C-H bond in oil spill are analyzed. And an oil spill spectral signature extraction model is designed by using the spectral feature of C-H bond. It is then used to obtain the reference spectral signature for the following oil spill detection step. Secondly, the characteristics of reflectance spectral signature of sea water, clouds, and oil spill are compared. The bands which have large difference in reflectance spectral signatures of the sea water, clouds, and oil spill are selected. By using these bands, the sea water pixels are segmented. And the background parameters are then calculated. Finally, the classical adaptive matched filter from target detection algorithms is improved and introduced for oil spill detection. The proposed method is applied to the real airborne visible infrared imaging spectrometer (AVIRIS) hyperspectral image captured during the deepwater horizon oil spill in the Gulf of Mexico for oil spill detection. The results show that the proposed method has, high efficiency, does not need artificial auxiliary work, and can be used for automatic detection of marine oil spill.

The 156KELK159 tetrapeptide of HIV-1 integrase is critical for lentiviral gene integration.

HIV-1 integrase (HIV-1 IN), a key element of HIV-1-derived lentiviral vectors, is crucial for the stable maintenance of the vector gene by inserting them into host genome. HIV-1 IN has been found to have functions other than integration, such as involving in virion morphology, viral DNA synthesis and viral DNA nuclear import. In our study, the yeast two-hybrid assay identified a tetrapeptide 156KELK159 in HIV-1 IN that was crucial for HIV-1 IN and Daxx interaction. To investigate the functions of the tetrapeptide 156KELK159 of the HIV-1 IN, both the wild type HIV-1 IN and a mutant without 156KELK159 were used to package the EGFP reporter gene contained lentivirus. p24 based titer assay revealed that deleting the tetrapeptide did not affect virus packaging. The result was verified by quantitative real time PCR with viral specific primers. But the 156KELK159 was crucial for lentiviral gene integration. Deleting the tetrapeptide made the percentage of cells expressing the reporter gene significantly decreased and did not affect the level of DNA entered into the cells or nucleus. Real time reverse transcription PCR and FACS were used to detect the lentiviral report gene expression in infection maintaining cells and revealed 156KELK159 did not affect lentiviral vector gene expression. Our results may shed light on the regulatory mechanism of gene integration of lentivirus.

Target acquisition performance in a cluttered environment.

Most existing target acquisition (TA) models neglect the influence of background clutter, which results in inaccurate prediction of TA performance in a complicated environment. In this paper, all the background clutter is first quantitatively characterized by the distribution of edge clutter metric, and its effects on the target detection probability are analyzed. Further, a novel TA model is developed by combining this proposed clutter metric and the target task performance metric based on probability statistics theory. Moreover, this proposed model is validated by the search_2 dataset, and experiment results show that it is more consistent with the subjective detection probability than other models.

Sparse-representation-based clutter metric.

Background clutter is becoming one of the most important factors affecting the target acquisition performance of electro-optical imaging systems. A novel clutter metric based on sparse representation is proposed in this paper. Based on sparse representation, the similarity vector is defined to describe the similarity between the background and the target in the feature domain, which is a typical feature of the background clutter. This newly proposed metric is applied to the Search_2 data set, and the experiment results show that its prediction correlates well with the detection probability of observers.

[A new imaging FTIR spectroradiometer].

According to the characteristic of single-element detector and non-imaging spectroradiometer, a new imaging FTIR spectroradiometer system was developed for spectral data acquisition This system is composed of a spectroradiometer, a synchronous controller and a scanning device. Using the data interface of spectroradiometer, spectral radiometric calibration can be achieved for the system. The image resolution is 500 x 500 pixels, spectral range is 667-5000 cm(-1), spectral resolution is 1 cm(-1), and space Field of view is 150 degrees, Instant Field of View is 0.3 degrees. Experiments were held for actual data acquisition and data analysis was made. The analysis result indicates that the proposed system is adequate for non-realtime imaging spectral data acquisition

Cellular protein TTRAP interacts with HIV-1 integrase to facilitate viral integration.

TTRAP is a PML-NB protein that is involved in the NF-kappaB signaling pathway. TTRAP was recently identified by yeast two-hybrid analysis as a HIV-1 integrase (HIV-1 IN) interacting protein. This interaction was verified by co-immunoprecipitation, GST pull-down, and intracellular imaging, and deletion assays suggested that the N-terminal 180 residues of TTRAP are responsible for the interaction. In stable TTRAP knock-down cell lines, the integration of viral vectors decreased significantly compared with non-silenced cell lines. Conversely, overexpression of TTRAP by transient transfection increased the percentage of integration events. This is the first time that TTRAP has been shown to interact with HIV-1 IN and facilitate lentiviral vector integration. These findings reveal a new function of TTRAP and expand our understanding of the cellular response to HIV infection. The interaction between TTRAP and HIV-1 IN may be useful in designing new anti-viral strategies as well as for improving the efficiency of lentiviral-vector-mediated gene delivery.

Effects of allisartan isoproxil on blood pressure and target organ injury in patients with mild to moderate essential hypertension.

Evidence has shown that angiotensin II type 1 receptor antagonists have lower blood pressure and have target organ protective effects, but this is not the case for the drug allisartan isoproxil. The aim of this study was to evaluate the effects of allisartan isoproxil on blood pressure and target organ injury in patients with mild to moderate essential hypertension.In total, 80 essential hypertensive participants were randomly divided into an allisartan group and a nifedipine group (n = 40 per group), and their blood pressure was measured once per month for 6 months. A 2-dimensional echocardiogram was performed at baseline and at the end of the study. The serum levels of renal injury indexes, endothelial function markers, inflammatory factors, blood biochemical assays and urinary measurements were determined at baseline and at 6 months.At the end of the study, both systolic and diastolic blood pressure were significantly decreased in the allisartan group compared with baseline and showed the same antihypertensive effect as the nifedipine group. Meanwhile, the left ventricular remodeling, 24-hours levels of urinary microalbumin, endothelial dysfunction, and arterial stiffness were all significantly improved compared with that of the baseline and the nifedipine group (all P < .05).The present study showed that allisartan isoproxil had favorable blood pressure lowering and heart, renal, and endothelial protective effects in patients with mild to moderate essential hypertension.

Daxx interacts with HIV-1 integrase and inhibits lentiviral gene expression.

The death-associated protein Daxx is a ubiquitously expressed gene in mammals and is widely involved in transcriptional regulation and cellular intrinsic immune response against incoming virus. We found here that knocking down endogenous Daxx with specific siRNA increased HIV-1-derived lentiviral reporter gene expression in 293T cells. This repressive effect of Daxx is not due to its inhibition on viral gene integration into the cellular genome and is independent of the ubiquitin promoter on the vFUGW lentiviral vector. Instead, this inhibition is dependent on Daxx's interaction with HIV-1 integrase. A histone deacetylases (HDACs) inhibitor increased reporter gene expression to the level similar to Daxx knockdown in vFUGW infected cells but there was no additive effect in combination of HDACs inhibitor and Daxx-specific siRNA. Our results suggest that Daxx may associate with HIV-1-derived lentiviral DNA via interacting with HIV-1 integrase and recruit HDACs to viral DNA to repress lentiviral gene expression.

[Preparation of palladium nanoparticles by laser ablation and its spectral properties study].

Palladium colloid was obtained via laser ablation under 1064 nm excitation from an Nd:YAG laser in redistilled deionized water. The Pd colloid consisted of "chemically pure" Pd nanoparticles, which were free from extraneous ions or other chemicals since no chemical reaction was involved in the preparation. There was no characteristic peak in UV/Vis spectrum of Pd colloid in the region of 200-800 nm. Hence, in contrast to the Au and Ag nanoparticles, the average size and the size distribution of the Pd nanoparticles could not be estimated from their UV/Vis adsorption spectral features. After the laser ablation, one drop (50 microL) of Pd colloid was deposited on the aluminum plate and dried naturally to form the Pd island films. This method resulted in the formation of a rough surface with a large number of separated Pd islands 20 microm in diameter. According to the SEM measurement, Pd nanoparticles with the average diameter of approximately 200 nm formed Pd island films. Surface-enhanced Raman scattering (SERS) activity of Pd colloid and Pd island films was evaluated by using 4-mercaptopyridine (4MPY) as a probe molecule. The SERS study revealed that Pd island film was a highly efficient SERS-active substrate while there was no SERS signal observed from Pd colloid. The surface enhancement factor of Pd island films for 4MPY was estimated, which could reach values as high as 8. 7 X 10(4) under 632.8 nm excitation. This value was comparable with the largest value of 10(4) cited in the literature. The SERS spectra of 4MPY molecules adsorbed on Pd surface showed that 4MPY molecules probably tilted from the Pd nanoparticle surface-via sulphur. By contrast, SERS spectrum of 4MPY adsorbed on Ag island films was recorded and analysed. From SERS data it was inferred that 4MPY molecules assumed the standing up orientation on the silver nanoparticle surface. It could be concluded that the 4MPY molecules were more perpendicular to the silver nanoparticle surface than to the Pd nanoparticle surface.

Double-passage ground-state cooling induced by quantum interference in the hybrid optomechanical system.

We propose a quantum interference cooling scheme for a nano-mechanical resonator (NAMR) in a hybrid optomechanical system. In our scheme, atoms are trapped in an optomechanical cavity, and this optomechanical cavity interacts both atoms and an optical cavity. Therefore, the absorption of the optomechanical resonator can be modified by quantum interference effects induced by the atom-cavity and cavity-cavity couplings. With the modification of the quantum interference, the desired transition for cooling is enhanced, while the undesired transition for heating can be suppressed. As a result, the NAMR vibration can be cooled down to its ground state. Particularly, with the assistance of the atoms, the experimental difficulty can be reduced since the effective decay rate of the cavity can be decreased via the quantum interference for the atom-cavity coupling.

Elevating VEGF-A and PDGF-BB secretion by salidroside enhances neoangiogenesis in diabetic hind-limb ischemia.

Hind-limb ischemia (HLI) is one of the major complication of diabetic patients. Angiogenesis potential in diabetic patients is severely disrupted, and the mechanism underlying it has not been fully elucidated, making it an obstacle for developing an efficient therapeutic angiogenesis strategy. Skeletal muscle cells, through their paracrine function, had been known to be critical for neoangiogenesis. Here we found that hyperglycemia upregulates the expression of skeletal muscle cells prolyl hydroxylase domain 3 (PHD3), which resulted in the decrease of the secretion of angiogenic factors, especially VEGF-A and PDGF-BB. We showed that treatment with salidroside, a small molecule drug, significantly suppresses PHD3 expression and increases VEGF-A and PDGF-BB secretion from skeletal muscle cells, which in turn enhances the proliferation and migration potentials of endothelial and smooth muscle cells. Finally, we demonstrated that intramuscular injection of salidroside into the ischemic hind limbs of diabetic HLI model mice could efficiently induce neoangiogenesis and blood perfusion recovery. Thus, our novel findings not only reveal the effects of hyperglycemia on the angiogenesis potential of skeletal muscle cells and the mechanism underlying it, but also provides a novel finding suggesting that salidroside might be a potential small molecule drug for diabetic HLI.

Fast optical cooling of a nanomechanical cantilever by a dynamical Stark-shift gate.

The efficient cooling of nanomechanical resonators is essential to exploration of quantum properties of the macroscopic or mesoscopic systems. We propose such a laser-cooling scheme for a nanomechanical cantilever, which works even for the low-frequency mechanical mode and under weak cooling lasers. The cantilever is coupled by a diamond nitrogen-vacancy center under a strong magnetic field gradient and the cooling is assisted by a dynamical Stark-shift gate. Our scheme can effectively enhance the desired cooling efficiency by avoiding the off-resonant and undesired carrier transitions, and thereby cool the cantilever down to the vicinity of the vibrational ground state in a fast fashion.

The Emerging Role of miR-223 in Platelet Reactivity: Implications in Antiplatelet Therapy.

Platelets are anuclear cells and are devoid of genomic DNA, but they are capable of de novo protein synthesis from mRNA derived from their progenitor cells, megakaryocytes. There is mounting evidence that microRNA (miRNA) plays an important role in regulating gene expression in platelets. miR-223 is the most abundant miRNAs in megakaryocytes and platelets. One of the miR-223-regulated genes is ADP P2Y12, a key target for current antiplatelet drug therapy. Recent studies showed that a blunted response to P2Y12 antagonist, that is, high on-treatment platelet reactivity (HTPR), is a strong predictor of major cardiovascular events (MACEs) in coronary heart disease (CHD) patients receiving antiplatelet treatment. Recent clinical cohort study showed that the level of circulating miR-223 is inversely associated with MACE in CHD patients. In addition, our recent data demonstrated that the level of both intraplatelet and circulating miR-223 is an independent predictor for HTPR, thus providing a link between miR-223 and MACE. These lines of evidence indicate that miR-223 may serve as a potential regulatory target for HTPR, as well as a diagnostic tool for identification of HTPR in clinical settings.