Acute suppurative thyroiditis with thyroid metastasis from oesophageal cancer

Not required for Clinical Vignette

Graded-index breathing solitons from Airy pulses in multimode fibers

Breathing solitons, as localized wave packets with a periodic evolution in amplitude and duration, are able to model extreme wave events in complex nonlinear dispersive systems. We have numerically studied the formation and manipulation of graded-index breathing solitons embedded in nonlinear multimode fibers based on a single nonlinear Schrödinger equation that includes the spatial self-imaging effect through a periodically varying nonlinear parameter. Through changing specific parameters of the input optical field, we can manipulate the period and depth of graded-index breathing soliton dynamics under different relative strengths between the dispersion length and the self-imaging period of the multimode fiber. Our study can explicitly derive a robust mechanism to control the behavior of the breathing localized structure directly and contribute to a better understanding of the much more complex nonlinear graded-index soliton dynamics in multimode fibers

Effects of Probiotics on Gut Microbiota in Type 2 Diabetes Patients

Objective: To study the effect of probiotics on gut microbiota in Type 2 diabetes patients and its clinical application value. Methods: Select Type 2 diabetes patients to take orally probiotics for 24 weeks, collect stool samples of subjects at the baseline and end of the trial, identify and analyze gut microbiota of each sample by 16srRNA high-throughput sequencing, and compare the changes of blood glucose, blood lipid and insulin resistance before and after the intervention. Results: A total of 75 patients completed clinical observations. 16srRNA high-throughput sequencing showed that the proportion of the subjects with increased Actinobacteria and Tenericutes at the end of the trial has increased (37.8% and 75.7% respectively). The genus level analysis showed that the number of subjects with increased intestinal probiotics and with decreased conditioned pathogens all increased. Cluster analysis before and after intervention showed that the gut microbiota of samples in the same group had a higher similarity. Compared with the subjects at the baseline status, at the end of the trial after the intervention, fasting blood glucose (FBG) of the subjects significantly decreased (P<0.05), the proportion of the subjects with triglyceride (TG) and cholesterol up to standard increased, and HOMA-IR was significantly improved (P<0.05). Conclusions: Probiotics can regulate the gut microbiota of Type 2 diabetes patients, promote fasting blood glucose (FBG) to reach the standard and improve insulin resistance, and help improve lipid metabolism

Optical event horizon-based complete transformation and control of dark solitons

We propose a manipulation approach to vary the wave speed, as well as the grayness, of dark solitons under the optical event horizon arising from the interaction between a dark soliton and a probe wave. To the best of our knowledge, the optical event horizon effect is demonstrated for the first time to be capable of inducing a reversible conversion between a black soliton and a gray one. This reversible soliton transformation and control process originates from the intrinsic competition between the probe-induced nonlinear phase shift and the internal phase of the dark soliton. In a cascaded system consisting of two optical event horizons, we also observe the new optical soliton tunneling phenomena where a dark soliton can be reset longitudinally purposely. The results may find applications in information cloaking such as effectively hiding the presence of intermediate fiber section to the receiver

Widely wavelength-tunable mid-infrared fluoride fiber lasers

We demonstrate widely wavelength-tunable continuous-wave (CW) and Q-switched Er3+-doped ZBLAN fluoride fiber lasers operating around 3 μm enabled by a volume Bragg grating (VBG). In the CW operation regime, a total wavelength tuning range of over 160-nm spanning from 2694 to 2854 nm has been achieved. For the Q-switched mode of operation, a slightly modified resonator configuration, incorporating a passive Q-switcher, topological insulator Bi2Te3 nanosheets, can produce stable pulse trains with a pulse width of 880 ns at a repetition rate of 81 kHz, while maintaining a wavelength tuning range of 62 nm from 2762 to 2824 nm through adjusting the VBG. In both operation regimes, the output spectral width is measured to be <;0.3 nm (full-width at half-maximum) over the whole tuning range. Our work both demonstrates the great wavelength-tuning potential of the Er3+ -doped fluoride fiber laser, and also paves a way for the development of a range of high-performance midinfrared laser sources

Observation of Three-dimensional Photonic Dirac points and Spin-polarized Surface Arcs

Topological phases arise from the elegant mathematical structures imposed by the interplay between symmetry and topology1-5. From gapped topological insulators to gapless semimetals, topological materials in both quantum and classical systems, have grown rapidly in the last decade. Among them, three-dimensional Dirac semimetal lies at the topological phase transition point between various topological phases. It shares multiple exotic topological features with other topological materials, such as Fermi arcs and chiral anomaly with Weyl semimetals30, spin-dependent surface states with topological insulators29. In spite of the important role it plays in topological physics, no experimental observation of three-dimension Dirac points has been reported in classical systems so far. Here, we experimentally demonstrate three-dimension photonic Dirac points in an elaborately designed photonic metamaterial, in which two symmetrically placed Dirac points are stabilized by electromagnetic duality symmetry31. Spin-polarized surface arcs (counterparts of Fermi arcs in electronic systems) are demonstrated, which paves the way towards spin-multiplexed topological surface wave propagation. Closely linked to other exotic states through topological phase transitions, our system offers an effective medium platform for topological photonics.Comment: 18 pages, 4 figure

Graded-index breathing solitons from Airy pulses in multimode fibers

Breathing solitons, as localized wave packets with a periodic evolution in amplitude and duration, are able to model extreme wave events in complex nonlinear dispersive systems. We have numerically studied the formation and manipulation of graded-index breathing solitons embedded in nonlinear multimode fibers based on a single nonlinear Schrödinger equation that includes the spatial self-imaging effect through a periodically varying nonlinear parameter. Through changing specific parameters of the input optical field, we can manipulate the period and depth of graded-index breathing soliton dynamics under different relative strengths between the dispersion length and the self-imaging period of the multimode fiber. Our study can explicitly derive a robust mechanism to control the behavior of the breathing localized structure directly and contribute to a better understanding of the much more complex nonlinear graded-index soliton dynamics in multimode fibers