The action of topical application of Vitamin B12 ointment on radiodermatitis in a porcine model.

Radiodermatitis is an inevitable side effect of radiotherapy in cancer treatment and there is currently no consensus on effective drugs for treating the condition. Vitamin B12 is known to be effective for repairing and regenerating damaged skin. However, there are few studies on the use of Vitamin B12 for treating radiodermatitis. This study explored the therapeutic efficacy and mechanism of action of Vitamin B12 ointment on radiodermatitis. A porcine model of grade IV radiodermatitis was established. The ointment was applied for 12 weeks after which histological staining, transmission electron microscopy, RT-qPCR, western blotting, and gene sequencing were performed for the evaluation of specific indicators in skin samples. After 12 weeks of observation, the Vitamin B12 treatment was found to have significantly alleviated radiodermatitis. The treatment also significantly reduced the expression levels of NF-κB, COX-2, IL-6, and TGF-ß in the skin samples. The pathways involved in the effects of the treatment were identified by analysing gene expression. In conclusion, Vitamin B12 ointment was found to be highly effective for treating radiodermatitis, with strong anti-radiation, anti-inflammatory, and anti-fibrosis effects. It is thus a promising drug candidate for the treatment of severe radiodermatitis.

Correlation of the detection rate of upper GI cancer with artificial intelligence score: results from a multicenter trial (with video).

BACKGROUND AND AIMS: The quality of EGD is a prerequisite for a high detection rate of upper GI lesions, especially early gastric cancer. Our previous study showed that an artificial intelligence system, named intelligent detection endoscopic assistant (IDEA), could help to monitor blind spots and provide an operation score during EGD. Here, we verified the effectiveness of IDEA to help evaluate the quality of EGD in a large-scale multicenter trial. METHODS: Patients undergoing EGD in 12 hospitals were consecutively enrolled. All hospitals were equipped with IDEA developed using deep convolutional neural networks and long short-term memory. Patients were examined by EGD, and the results were recorded by IDEA. The primary outcome was the detection rate of upper GI cancer. Secondary outcomes were part scores, total scores, and endoscopic procedure time, which were analyzed by IDEA. RESULTS: A total of 17,787 patients were recruited. The total detection rate of cancer-positive cases was 1.50%, ranging from .60% to 3.94% in each hospital. The total detection rate of early cancer-positive cases was .36%, ranging from .00% to 1.58% in each hospital. The average total score analyzed by IDEA ranged from 64.87 ± 16.87 to 83.50 ± 9.57 in each hospital. The cancer detection rate in each hospital was positively correlated with total score (r = .775, P = .003). Similarly, the early cancer detection rate was positively correlated with total score (r = .756, P = .004). CONCLUSIONS: This multicenter trial confirmed that the quality of the EGD result is positively correlated with the detection rate of cancer, which can be monitored by IDEA. (Clinical trial registration number: ChiCTR2000029001.).

Magnon-induced optical high-order sideband generation in hybrid atom-cavity optomagnonical system.

The nonlinearity of magnons plays an important role in the study of an optomagnonical system. Here in this paper, we focus on the high-order sideband and frequency comb generation characteristics in the atom coupled optomagnonical resonator. We find that the atom-cavity coupling strength is related to the nonlinear coefficients, and the efficiency of sidebands generation could be reinforced by tuning the polarization of magnons. Besides, we show that the generation of the sidebands could be suppressed under the large dissipation condition. This study provides a novel way to engineer the low-threshold high-order sidebands in hybrid optical microcavities.

Direct measurement of radial fluence distribution inside a femtosecond laser filament core.

Modulation and direct measurement of the radial fluence distribution inside a single filament core (especially less than 100 µm in diameter) is crucial to filament-based applications. We report direct measurements of the radial fluence distribution inside a femtosecond laser filament core and its evolution via the filament-induced ablation method. The radial fluence distributions were modulated by manipulating the input pulse diffraction through an iris. Compared with using a traditionally circular iris, a stellate iris substantially suppressed the diffraction effect, and laser fluence, intensity and plasma density inside the filament core were considerably increased. The radial fluence inside filament cores was also quantitatively measured via the filament drilling diaphragms approach. Furthermore, numerical simulations were performed to support the experimental results by solving nonlinear Schrödinger equations. The effects of the tooth size of the stellate iris were numerically investigated, which indicated that bigger tooth favors higher fluence and longer filament. In addition to being beneficial in understanding the filamentation process and its control, the results of this study can also be valuable for filament-based applications.

Laser ellipticity-dependent supercontinuum generation by femtosecond laser filamentation in air.

We experimentally investigate the laser polarization effect on the supercontinuum (SC) generation through femtosecond laser filamentation in air. By tuning filamenting laser ellipticity from linear polarization to circular polarization, the spectral intensity of the SC after filamentation gradually increases, while the spectral bandwidth of the SC continuously decreases. The laser ellipticity-dependent spectral intensity modulation of the SC is stronger at higher filamenting pulse energy. Laser energy deposits more in linearly polarized laser filaments than in circularly polarized laser filaments. The experimental results are supported by numerical simulations. A physical picture based on the laser ellipticity-dependent clamped intensity inside the filament, together with the Kerr nonlinearity and plasma related self-phase modulations, is proposed to explain the observation.

Berry phase in an anti-PT symmetric metal-semiconductor complex system.

Berry phase can be used to generate quantum state which is robust to environmental noises in quantum information processing. Recently, the relationship between Berry phase and quantum phase transition attracts great attention in the research about topological states of matter. Here, we investigate the behavior of Berry phase in an anti parity-time symmetric system consisting of a metal nanoparticle and semiconductor quantum dot. The change of Berry phase undergoes a sudden death around exceptional point, i.e., Berry phase keeps unchanged in symmetry unbroken region, while it can be well adjusted through changing the strength and frequency of input light in symmetry broken region. The result demonstrated in this paper may be of significant importance in quantum computation and topological physics.

Temporal evolution of condensation and precipitation induced by a 22-TW laser.

Water condensation and precipitation induced by 22-TW 800-nm laser pulses at 1 Hz in an open cloud chamber were investigated in a time-resolved manner. Two parts of precipitation in two independent periods of time were observed directly following each laser shot. One part started around the filament zone at t < 500 µs and ended at t ≅ 1.5 ms after the arrival of the femtosecond laser pulse. The other following the laser-induced energetic air motion (turbulence), started at t ≅ 20 ms and ended at t ≅ 120 ms. Meanwhile, the phase transitions of large-size condensation droplets with diameters of 400-500 µm from liquid to solid (ice) in a cold area (T < -30 °C) were captured at t ≅ 20 ms.

Optothermal control of gains in erbium-doped whispering-gallery microresonators.

Erbium-doped whispering-gallery-mode (WGM) microcavities have great potential in many important applications, such as the precision detection and the micro/nano laser. However, they are sensitive to the fluctuations from the pump laser and the environment. Here we demonstrate the precise controlling of transmission spectra and optical gains using optothermal scanning methods in erbium-doped WGM microcavities. The transmission spectrum of the probe signal exhibits the transition between asymmetric Fano-like resonance and the Lorentz peak (or dip) through tuning the input frequency and the scanning speed of the pump laser. In particular, the analytical calculations can fit well with our experimental results through adiabatically eliminating the anticlockwise optical mode. This Letter shows that the optothermal control of gains is more robust to external noises, which paves a crucial step toward the application in the ultra-sensitive detection.

Optomechanically engineered phononic mode resonance.

Optomechanics describes the interaction between the optical field and mechanics, and the optomechanical system provides an ideal interface between photons and phonons. The role of the electromagnetic field during optomechanical interaction is studied in this paper as it is regarded as a phonon transmission medium. An analytical model is built to study the phononic mode resonance and reveals the transmission properties of the phonons, which are related to the variance of the frequency of the electromagnetic field. Moreover, when one mechanical mode is driven, different mode resonant properties could be achieved on the transmission spectrum of phonons between the two mechanical modes. We believe that the current work provides significant results for the research of phononic devices.

Hyperentanglement purification using imperfect spatial entanglement.

As the interaction between the photons and the environment which will make the entangled photon pairs in less entangled states or even in mixed states, the security and the efficiency of quantum communication will decrease. We present an efficient hyperentanglement purification protocol that distills nonlocal high-fidelity hyper-entangled Bell states in both polarization and spatial-mode degrees of freedom from ensembles of two-photon system in mixed states using linear optics. Here, we consider the influence of the photon loss in the channel which generally is ignored in the conventional entanglement purification and hyperentanglement purification (HEP) schemes. Compared with previous HEP schemes, our HEP scheme decreases the requirement for nonlocal resources by employing high-dimensional mode-check measurement, and leads to a higher fidelity, especially in the range where the conventional HEP schemes become invalid but our scheme still can work.

Implementation of single-photon quantum routing and decoupling using a nitrogen-vacancy center and a whispering-gallery-mode resonator-waveguide system.

Quantum router is a key element needed for the construction of future complex quantum networks. However, quantum routing with photons, and its inverse, quantum decoupling, are difficult to implement as photons do not interact, or interact very weakly in nonlinear media. In this paper, we investigate the possibility of implementing photonic quantum routing based on effects in cavity quantum electrodynamics, and present a scheme for single-photon quantum routing controlled by the other photon using a hybrid system consisting of a single nitrogen-vacancy (NV) center coupled with a whispering-gallery-mode resonator-waveguide structure. Different from the cases in which classical information is used to control the path of quantum signals, both the control and signal photons are quantum in our implementation. Compared with the probabilistic quantum routing protocols based on linear optics, our scheme is deterministic and also scalable to multiple photons. We also present a scheme for single-photon quantum decoupling from an initial state with polarization and spatial-mode encoding, which can implement an inverse operation to the quantum routing. We discuss the feasibility of our schemes by considering current or near-future techniques, and show that both the schemes can operate effectively in the bad-cavity regime. We believe that the schemes could be key building blocks for future complex quantum networks and large-scale quantum information processing.

Computed Tomography-Guided Interstitial Brachytherapy for Locally Advanced Cervical Cancer: Introduction of the Technique and a Comparison of Dosimetry With Conventional Intracavitary Brachytherapy.

OBJECTIVE: We present a new technique of 3-dimensional computed tomography-guided interstitial (IS) brachytherapy (BT) for locally advanced cervical cancer, offering a more advantageous clinical treatment approach. MATERIALS/METHODS: Interstitial BT was performed using an applicator combining uterine tandem and metal needles; needles were inserted freehand under real-time 3-dimensional computed tomography guidance. Twenty-eight patients with bulky tumors and/or parametrial extension (tumor size > 5 cm) after external beam radiotherapy received IS BT. Dosimetric outcomes of the IS BT including the total dose (external beam radiotherapy and high dose-rate BT) D90 for the high-risk clinical target volume (HR-CTV) and D2cc for the organs at risk (OARs) were investigated and compared with a former patient group consisting of 30 individuals who received the conventional intracavitary (IC) BT. RESULTS: The mean D90 values for HR-CTV in the IC BT and IS BT groups were 76.9 ± 5.7 and 88.1 ± 3.3 Gy, respectively. Moreover, 85.7% of the patients received D90 for HR-CTV of 87 Gy or greater in the IS BT group, and only 6.7% of the patients received D90 for HR-CTV of 87 Gy or greater in the IC BT group. The D2cc for the bladder, rectum, and sigmoid were 84.7 ± 6.8, 69.2 ± 4.2, and 67.8 ± 4.5 Gy in the IC BT group and 81.8 ± 6.5, 66.8 ± 4.0, and 64.8 ± 4.1 Gy in the IS BT group. The mean number of needles was 6.9 ± 1.4, with a mean depth of 2.9 ± 0.9 mm for each IS BT. Interstitial BT was associated with only minor complications. CONCLUSIONS: The IS BT technique resulted in better dose-volume histogram parameters for large volume tumors (>5 cm) compared with the conventional IC BT and acceptable risk of acute complications in locally advanced cervical cancer and is clinically feasible.

Construction of high-dimensional universal quantum logic gates using a Λ system coupled with a whispering-gallery-mode microresonator.

High-dimensional quantum system provides a higher capacity of quantum channel, which exhibits potential applications in quantum information processing. However, high-dimensional universal quantum logic gates is difficult to achieve directly with only high-dimensional interaction between two quantum systems and requires a large number of two-dimensional gates to build even a small high-dimensional quantum circuits. In this paper, we propose a scheme to implement a general controlled-flip (CF) gate where the high-dimensional single photon serve as the target qudit and stationary qubits work as the control logic qudit, by employing a three-level Λ-type system coupled with a whispering-gallery-mode microresonator. In our scheme, the required number of interaction times between the photon and solid state system reduce greatly compared with the traditional method which decomposes the high-dimensional Hilbert space into 2-dimensional quantum space, and it is on a shorter temporal scale for the experimental realization. Moreover, we discuss the performance and feasibility of our hybrid CF gate, concluding that it can be easily extended to a 2n-dimensional case and it is feasible with current technology.

High-efficient entanglement distillation from photon loss and decoherence.

We illustrate an entanglement distillation protocol (EDP) for a mixed photon-ensemble which composed of four kinds of entangled states and vacuum states. Exploiting the linear optics and local entanglement resource (four-qubit entangled GHZ state), we design the nondemolition parity-checking and qubit amplifying (PCQA) setup for photonic polarization degree of freedom which are the key device of our scheme. With the PCQA setup, a high-fidelity entangled photon-pair system can be achieved against the transmission losses and the decoherence in noisy channels. And in the available purification range for our EDP, the fidelity of this ensemble can be improved to the maximal value through iterated operations. Compared to the conventional entanglement purification schemes, our scheme largely reduces the initialization requirement of the distilled mixed quantum system, and overcomes the difficulties posed by inherent channel losses during photon transmission. All these advantages make this scheme more useful in the practical applications of long-distance quantum communication.

Discerning electromagnetically induced transparency from Autler-Townes splitting in plasmonic waveguide and coupled resonators system.

Electromagnetically induced transparency (EIT) and Autler-Townes splitting (ATS) are two phenomena that can affect the transmission of a probe field in the presence of a stronger field, both yielding transparency in the absorption profile. Being able to discriminate these two similar but distinct phenomena is of vital importance. Here we propose a scheme to describe the EIT and ATS phenomena in a plasmonic system. The proposed system consists of one radiative resonator and one subradiant resonator in metal-insulator-metal waveguide, and the transition is observed from the ATS model to the EIT model through three qualitative regions as the coupling strength decreases. In addition, we apply the method proposed by Anisimov to the induced transparency spectrum in our model, and numerically discerning EIT from ATS based on the Akaike's information criterion in a clear way.

One-step hyperentanglement purification and hyperdistillation with linear optics.

We investigate a new approach for achieving hyperdistillation and hyperentanglement purification operations simultaneously on two-photon systems, whose state is described by nonlocal hyperentangled Bell states on both the spatial mode and polarization degree of freedoms. Exploiting linear optics and local entanglement resource, the quantum nondemolition (QND) parity-checking measurement and the heralded two-qubit amplification could are key steps in our scheme. With the QND parity-checking measurement and heralded qubit amplification operations, both the bit-flip (phase-flip) errors caused by decoherence in noisy channels and the vacuum errors caused by the transmission losses can be corrected. We show that the proposed scheme provides a new solution to overcome the problem of photon losses and decoherence simultaneously, which could be achieved with current technologies.

Pulse polarization evolution and control in the wake of molecular alignment inside a filament.

The polarization evolution and control of a femtosecond laser pulse in the wake of molecular alignment inside a laser filament was investigated. A weak probe pulse was delayed with respect to the field-free revivals of the pre-excited rotational wave-packets created by an infrared filamenting pulse in nitrogen gas. 30° was set between the pump and probe's initial linear polarization directions in order to control the output probe's polarization ellipse. The detailed physical response of the probe's polarization states was analyzed in the wake of alignment and dephasing of molecular N(2). The probe's polarization was modulated by varying the retarded time between the pump and probe pulses.

Concentration of entangled nitrogen-vacancy centers in decoherence free subspace.

Exploiting the input-output process of low-Q cavities confining nitrogen-vacancy centers, we present an efficient entanglement concentration protocol on electron spin state in decoherence free subspace. Less entangled state can be concentrated to maximally entangled state with the assistance of single photon detection. With its robustness and scalability, the present protocol is immune to dephasing and can be further applied to quantum repeaters and distributed quantum computation.

Investigation of a chalcohalide glass optical waveguide structure fabricated by dual-energy carbon-ion implantation.

A planar waveguide structure in a chalcohalide glass was fabricated by dual-energy C ion implantation with energies of 5.5 and 6.0 MeV at fluences of 7.0×10¹4 and 8.0×10¹4ions cm⁻², respectively. A waveguide with a thickness of 5.9 µm was formed. SRIM 2013 was used to simulate the defect distribution fabricated by C ion implantation. Images of the polished end face of the C-implanted chalcohalide glass were measured with a metallographic microscope using reflected polarized light. The micro-Raman spectra were measured in air. The near-field intensity distributions were investigated at visible (633 nm) and near-infrared (1300, 1400, and 1539 nm) bands.

Comparison of waveguide properties and Raman spectroscopic visualization of C and O ion implantation on LaAlO(3) crystals.

LaAlO3 crystals were implanted by C ions and O ions at an energy of 6.0 MeV with a fluence of 1.5×1015 ions/cm2. The profiles of the guided modes were measured through prism coupling and end-face coupling methods with a 633 nm laser source. A nonleaky waveguide structure in the TM mode was fabricated by O ion implantation after a proper annealing treatment. Characteristics of the implanted C and O ions were compared. Some changes of the full width at half of the maximum and intensity of the Raman spectra were observed between the waveguide and substrate regions in LaAlO3 crystals. Thus, the Raman spectra can be used to visualize any damage or defects in the LaAlO3 crystals during the implantation process.