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Myocardial infarction (MI) is lethal to patients because of acute ischemia and hypoxia leading to cardiac tissue apoptosis. Autophagy played a key role in MI through affecting the survival of cardiomyocytes. LncRNA-MHRT (myosin heavy-chain-associated RNA transcripts) was specific to the heart and cardiomyocytes, and inhibition of lncRNA-MHRT transcription under pathological stimuli could cause cardiac hypertrophy and even heart failure (HF). Sonodynamic therapy (SDT) is a new and developing medical technique that utilizes low-intensity ultrasound to locally activate a preloaded sonosensitizer. Our group previously reported that SDT could regulate autophagy. In this study, we investigated whether SDT could reduce MI-induced cardiomyocyte apoptosis via activating autophagy pathway. SDT improved cardiac function and suppresses MI-induced cardiomyocyte apoptosis. SDT alleviated MI-induced cardiomyocyte apoptosis by improving autophagy. MHRT mediated the inhibiting effect of SDT on cardiomyocyte apoptosis via activating autophagy pathway. Our data reveal a novel effect that SDT protects against MI and confirm that SDT reduces MI-induced cardiomyocyte apoptosis via activating MHRT-mediated-autophagy. Thus, our findings also indicate that SDT may be used as a potential method for treatment of post-myocardial infarction heart failure.

This study was intended to explore the effect of proanthocyanidin (PC) combined with trimetazidine in non-small-cell lung cancer (NSCLC) with radiation-induced heart damage (RIHD). It was a prospective randomized controlled study that 86 NSCLC patients with radiation treatment in Cangzhou People’s Hospital from January 2019 and June 2021 were enrolled and randomized to either the control group or the study group via the random table method, 43 cases in each group. The control group received trimetazidine, and the study group additionally received PC. The incidence of RIHD-related clinical manifestation, RIHD-related ECG, and RIHD-related cardiac ultrasound change were all lower in the study group. After radiotherapy, the serum level of superoxide dismutase (SOD) was higher, and malondialdehyde (MDA) was lower in the study group when compared with the control group. After radiotherapy, the serum levels of brain natriuretic peptide (BNP), cardiac troponin (cTnT), creatine kinase (CK), and creatine kinase isoenzymes (CKMB) were all lower in the study group when compared with the control group. The efficacy of PC plus trimetazidine for NSCLC with RIHD is superior to trimetazidine alone, and it significantly mitigates radiation-induced inflammatory response and oxidative stress.

Wave environment is a common fact happened when objects enter water under real conditions, which changes the morphology of the free interface when entering water. However, the influence of wave environment on the flow when entering water and on the evolution of object motion parameters after entering water is not clear. In this research, a rocking plate wave maker is used to generate a wave environment in the test pool, and a truncated cone rotating body equipped with an internal test system is used as the test model. The compressed air cannon is used to provide launch power, and the launch control system uniformly controls the start timing process of the wave maker and the launcher. The wave maker and the launcher will control the relative position of the object's entry point and the wave surface in collaboration. Various condition tests were carried out, including enter in static water, different wave surface positions and different wave heights. Quantitative trajectory parameters including the acceleration, and attitude angle of the model in the water-entry process were obtained, and the evolution of the flow field was photographed. The experimental results show that under high-speed conditions, the influence of waves on the water-entry process is mainly reflected in the change of the water entry angle relative to the water surface at the water-entry moment. The wave surface encountering negative inclination can effectively reduce the impact load of water entry, but it is more likely to induce the extreme situation such as "jumping".

We have demonstrated waveguide integration of terahertz quantum cascade lasers (THz QCLs) at frequencies above 4.7 THz. A precision micromachining technique, followed by diamond-turning and electroless-plating has been used to manufacture hollow rectangular waveguides with integrated diagonal feedhorns. We show that surface roughness at the 1μm level is achieved, enabling outcoupling of radiation in the 4.75–5.05 THz band, with a divergence angle of 5° along the plane of the QCL substrate.

An ongoing outbreak of pneumonia associated with 2019 novel coronavirus was reported in China. It is unclear whether the virus is infective exists during the incubation period, although person-to-person transmission has been reported elsewhere. We report the epidemiological features of a familial cluster of 4 patients in Shanghai, including an 88-year-old man with limited mobility who was exposed only to asymptomatic family members whose symptoms developed later. The epidemiological evidence has shown possible transmission of 2019 novel coronavirus during the incubation period., In a familial cluster of four 2019 novel coronavirus (nCoV) cases in Shanghai, the first patient was exposed only to asymptomatic family members, whose symptoms developed later. These findings suggest possible transmission of 2019-nCoV during the incubation period.

By taking into account sampled-data mechanism and transmission delay, the novel event-triggering load frequency control (LFC) strategy involving random dynamic triggering algorithm (RDTA) is developed for multi-area power systems in this paper. Firstly, an improved multi-area LFC model considering sampling and transmission delay (STD) simultaneously is addressed. Secondly, a modified event-triggering mechanism (ETM) with RDTA is proposed, considering parameter disturbances and a dynamic adjustment mechanism of the triggering threshold. Thirdly, a more advanced Lyapunov-Krasovskii functional (LKF) is constructed, introducing the delay-dependent matrices, more variable cross terms and the two-sided closed functional. Furthermore, two less conservative stability criteria are obtained according to the designed approach. Finally, two multi-area LFC systems are presented to verify the progressiveness of the proposed approach.

We have developed precision micromachining techniques for integration of terahertz quantum cascade lasers (QCLs) with waveguides and feedhorns for use as local oscillators in satellite-borne receivers. We demonstrate these techniques using QCLs at 3.4 THz and 4.7 THz, as well as the first QCL with a monolithically integrated power modulator.

We demonstrate a terahertz gas spectroscopy technique based on self-mixing in a multimode quantum cascade laser (QCL). The spectral parameters of the H/D exchange reaction between water (H 2 O) and deuterated water (D 2 O) have been measured between 3.36-3.37 THz.

In the present work, the drought response in Tiger grass (Thysanolaena latifolia) plants has been investigated by monitoring water status using THz QCL based Laser Feedback Interferometry imaging technique.

We present a self-mixing terahertz-frequency gas spectroscopy technique using a multimode quantum cascade laser. A precision-micro-machined external waveguide module and a double-metal quantum cascade laser device are used to increase the optical feedback and the laser’s frequency tuning range. Methanol spectra are obtained using two laser modes at 3.362 THz and 3.428 THz simultaneously, with more than 8 absorption peaks resolved over a 17-GHz bandwidth, which provide minimum detectable absorption coefficients of 2.7×10-4 cm−1 and 4.9×10−4 cm−1, respectively. In contrast to all previous self-mixing spectroscopy, our multimode technique expands the sensing bandwidth significantly. This broadband spectroscopy technique can potentially be used for the identification and analysis of chemical, biological radiological and nuclear (CBRN) agents and explosives.

we present an electromagnetic-field analysis of a terahertz-frequency quantum-cascade laser (THz QCL) integrated with a mechanically micro-machined waveguide cavity and diagonal feedhorn. A hybrid finite-element/Fourier transform approach enables analysis of both the near-field and far-field regions and is shown to agree well with experimental observations. The far-field antenna patterns show enhancement of the beam profile when compared with an unmounted QCL, in terms of beam divergence and side-lobe suppression ratio. Furthermore, we demonstrate integration of the QCL with dual diagonal feedhorns, enabling simultaneous access to both facets of the QCL, underpinning future integration with a satellite-based receiver and frequency-stabilization subsystem.

We report a coherent terahertz (THz) imaging system that utilises a quantum cascade laser (QCL) operating in pulsed-mode as both the source and detector. The realisation of a short-pulsed THz QCL feedback interferometer permits both high peak powers and improved thermal efficiency, which enables the cryogen-free operation of the system. In this work, we demonstrated pulsed-mode swept-frequency laser feedback interferometry experimentally. Our interferometric detection scheme not only permits the simultaneous creation of both amplitude and phase images, but inherently suppresses unwanted background radiation. We demonstrate that the proposed system utilising microsecond pulses has the potential to achieve 0.25 mega-pixel per second acquisition rates, paving the pathway to video frame rate THz imaging.

Terahertz-frequency quantum-cascade lasers (THz QCLs) are compact, electrically-driven sources of narrowband radiation in the ~2–5-THz band. Numerous scientifically important gas-phase species within the Earth’s upper atmosphere have distinctive spectral features within this band, making QCLs attractive sources for spectroscopic and radiometric atmospheric studies. In this paper, we demonstrate the integration of a QCL with a satellite-compliant cryocooler, precision-micromachined waveguide, a pair of diagonal feedhorns and a Cassegrain telescope, as key steps toward a complete 3.5-THz integrated receiver system.

With the popularity of large data network, data mining technology can be used in human resource management and provide strong decision support. In this paper, the author put forward the application of BIRCH clustering algorithm in HRM database, and analyze the associated reasoning methods. Based on the multiple regression analysis, the result shows that strategic human resource management effectiveness has significant positive correlation with organizational innovation (p

With the development of social economy, the public cultural service is the main service platform for the whole society, which not considers profit as the purpose. However, as the characteristics of the China’s government function and the financial investment, the government tends to pursue the maximization of the scale, then how to scientifically evaluate the performance of public cultural services has become a hot issue. In this paper, the authors construct the performance evaluation index of public cultural service based on web survey, and make empirical analysis by using DEA method. The result shows that the overall efficiency of national museum is moderate; the efficiency level is 0.87. At the same time, the overall efficiency of the national public library is low; the efficiency level is 0.746. On this basis, we put forward relevant policy recommendations

We demonstrate continuous frequency tuning in terahertz quantum cascade lasers with double metal waveguides using a Y-branched coupler. Two THz QCLs placed side-by-side couple by evanescent fields across the air gap between them. Each QCL waveguide comprises a 48-μm-wide coupler and S-bend section, which are connected to an 88-μm-wide Y-branch through an impedance matching tapered section. Photonic lattices are patterned on top of the coupler section in each QCL using focused ion-beam milling to control the spectral characteristics. The waveguide design used for individual QCL sections is optimized using finite element modelling and the spectral characteristics are modelled using a transfer matrix model. Continuous frequency tuning of ~19 GHz is demonstrated while maintaining an output power of ~4.2–4.8 mW and a heat sink temperature of 50 K. The tuning is controlled electrically through Stark shift and cavity pulling effects by driving both QCLs simultaneously and represents the widest electrically-controlled continuous tuning performance from a THz QCL without significant change in output power.

We report electrically-controlled continuous frequency tuning over ∼20 GHz by exploiting the additive Vernier tuning effect in a THz QCL based on a longitudinally-coupled Y-branched waveguide.

We present antenna-pattern measurements obtained from a double-metal supra-terahertz-frequency (supra-THz) quantum cascade laser (QCL) mounted within a mechanically micro-machined waveguide cavity and dual diagonal feedhorn assembly. With the QCL operating in continuous-wave mode at 3.5 THz, and at an ambient temperature of ∼60 K, emission from both laser facets has been simultaneously directed to a suitable supra-THz detector mounted on a multi-axis linear scanner. Comparison of simulated and measured far-field antenna patterns shows an excellent degree of correlation between beamwidth (full-width-half-maximum) and sidelobe content. Furthermore, when compared with unmounted equivalents, very substantially enhanced QCL beam profiles are observed. Our novel device demonstrates the effectiveness of diagonal feedhorns intended for use in future spaceborne Earth-observing supra-THz heterodyne radiometers.

The authors demonstrate a broadband, heterogeneous terahertz frequency quantum cascade laser by exploiting an active region design based on longitudinal optical-phonon-assisted interminiband transitions. They obtain continuous wave laser emission with a threshold current density of ~120 A/cm 2 , a dynamic range of ~3.1, and an emission spectrum spanning from 2.4 to 3.4 THz at 15 K.

We present the first antenna power measurements from a double metal terahertz-frequency quantum cascade laser (THz QCL) mounted within a waveguide cavity and incorporating dual diagonal feedhorns that enable directional output coupling of THz radiation from both laser facets. The feedhorn antenna patterns have been measured simultaneously at a frequency of 3.5 THz and with the QCL operating at an ambient temperature of 60 K in continuous wave mode. Comparison with a feedhorn theoretical model shows good pattern correlation and implies that the QCL signal is likely propagating within the waveguide in a fundamental mode.

We report the development of terahertz frequency quantum cascade lasers for applications as local oscillators. A range of active region designs and waveguide structures have been characterised in order to develop the devices for operation at high temperatures, with high output power and low dissipated power. Quantum cascade lasers based on a LO-phonon bound-to-continuum design emitting at 3.5 THz, suitable for the detection of hydroxyl, were fabricated with a double-metal (gold-gold) waveguide structure. These devices operated in continuous-wave up to 94 K, with an output power of 0.4 mW and dissipated power of 1.7 W at 10 K. A new, mechanically robust packaging and waveguide-integration scheme is also presented for operation outside laboratory environments, which further allows integration of quantum cascade lasers with terahertz waveguides, mixers and other system components. This integration scheme yielded a better beam quality, with a divergence of

Terahertz-frequency quantum cascade lasers (THz QCLs) have numerous potential applications as 1–5 THz radiation sources in space science, biomedical and industrial sensing scenarios. However, the key obstacles to their wide-scale adoption outside laboratory environments have included their poor far-field beam quality and the lack of mechanically robust schemes that allow integration of QCLs with THz waveguides, mixers and other system components. A block integration scheme is presented, in which a continuous-wave ∼3.4 THz double-metal QCL is bonded into a precision-machined rectangular waveguide within a copper heat-sink block. This highly reproducible approach provides a single-lobed far-field beam profile with a divergence of ≲20°, and with no significant degradation in threshold current or in the range of operating temperatures.

We report an extraction-controlled terahertz (THz)-frequency quantum cascade laser design in which a diagonal LO-phonon scattering process is used to achieve efficient current injection into the upper laser level of each period and simultaneously extract electrons from the adjacent period. The effects of the diagonality of the radiative transition are investigated, and a design with a scaled oscillator strength of 0.45 is shown experimentally to provide the highest temperature performance. A 3.3 THz device processed into a double-metal waveguide configuration operated up to 123 K in pulsed mode, with a threshold current density of 1.3 kA/cm2 at 10 K. The QCL structures are modeled using an extended density matrix approach, and the large threshold current is attributed to parasitic current paths associated with the upper laser levels. The simplicity of this design makes it an ideal platform to investigate the scattering injection process.

The LOCUS atmospheric sounder is a satellite-borne THz radiometer concept, for studying molecular species in the mesosphere and lower thermosphere. We report waveguide-integrated THz quantum-cascade lasers for use as 3.5 THz local oscillators. A waveguide-integration scheme, using an integrated diagonal feedhorn significantly improves power outcoupling. 1.3 mW THz emission is demonstrated in a space-qualified Stirling cryocooler at 57 K, with ∼15° beam divergence.

A hybrid mode section is integrated into the end of the metal-metal waveguide of a terahertz (THz) frequency quantum cascade laser (QCL) by removing sub-wavelength portions of the top metal layer. This allows a hybrid mode to penetrate into the air, which reduces the effective index of the mode and improves the out-coupling performance at the facet. The transmission of the hybrid section is further increased by ensuring its length fulfills the criterion for constructive interference. These simple modifications to a 2.5-THz metal-metal QCL waveguide result in a significant increase in the output emission power. In addition, simulations show that further improvements in out-coupling efficiency can be achieved for lower frequencies with effective refractive indices close to the geometric mean of the indices of the metal-metal waveguide and air.

Since their first demonstration in 2002, the performance of terahertz frequency quantum cascade lasers has developed extremely rapidly. We consider the potential use of terahertz frequency quantum cascade lasers as local oscillators in satellite-borne instrumentation for future Earth observation and planetary science missions. A specific focus will be on the development of compact, waveguide-integrated, heterodyne detection systems for the supra-terahertz range.

We demonstrate a gas spectroscopy technique, using self-mixing in a 3.4 terahertz quantum-cascade laser (QCL). All previous QCL spectroscopy techniques have required additional terahertz instrumentation (detectors, mixers, or spectrometers) for system pre-calibration or spectral analysis. By contrast, our system self-calibrates the laser frequency (i.e., with no external instrumentation) to a precision of 630 MHz (0.02%) by analyzing QCL voltage perturbations in response to optical feedback within a 0–800 mm round-trip delay line. We demonstrate methanol spectroscopy by introducing a gas cell into the feedback path and show that a limiting absorption coefficient of ∼1×10⁻⁴ cm⁻¹ is resolvable.

We demonstrate high-performance THz QCLs lasing at 2.2, 2.53, 3.5 and 4.7 THz, which target absorption lines of water, methane, hydroxyl and atomic oxygen respectively. Reliable single-mode targeting of gas species is obtained through the use of a photonic lattice design. A highly reproducible micro-machined waveguide block yields narrow beam-divergence and enables future integration of a complete THz heterodyne system including local-oscillator, mixer, and feed-horn.

A hybrid mode section is integrated into the end of the metal-metal (MM) waveguide of a terahertz (THz) frequency quantum cascade laser (QCL) by removing sub-wavelength portions of the top metal layer. This allows a hybrid mode to penetrate into the air, which reduces the effective index of the mode and improves the out-coupling performance at the facet. The transmission of the processed metal-metal hybrid section (MMHS) waveguide is further increased by ensuring its length fulfills the criterion for constructive interference. These simple modifications to a 2.5 THz MM QCL waveguide result in a significant increase in the output emission power. In addition, simulations show that further improvements in out-coupling efficiency can be achieved for lower frequencies with effective refractive indices close to the geometric mean of the indices of the MM waveguide and air.

Different ammonia flow rates were used during temperature ramping up to 1050°C after InGaN/GaN multiple quantum wells (MQWs) were grown at 820°C. Temperature-dependent photoluminescence (PL) as well as time-resolved PL (TRPL) spectra were measured and higher optical efficiency was obtained when higher ammonia flow rates were used. The effects of ammonia flow on the optical properties of InGaN/GaN multiple quantum wells were attributed to different indium content redistribution. At lower ammonia flow, In-rich regions became more uniform while the number of the In-rich regions decreased as a result of the disappearance of some In-rich regions with less In-rich regions. We ascribed enhancement of desorption of indium atoms to the lower ammonia flow.