Broadband opto-mechanical phase shifter for photonic integrated circuits

A broadband opto-mechanical phase shifter for photonic integrated circuits is proposed and numerically investigated. The structure consists of a mode-carrying waveguide and a deformable non-mode-carrying nanostring, which are parallel with each other. Utilizing the optical gradient force between them, the nanostring can be deflected. Thus the effective refractive indices of the waveguide is changed with the deformation, and further causes a phase shift. The phase shift under different geometry sizes, launched powers and boundary conditions are calculated and the dynamical properties as well as the thermal noise's effect are also discussed. It is demonstrated that a $\pi$ phase shift can be realized with only about 0.64 mW launched power and 50 $\mu m$ long nanostring. The proposed phase shifter may find potential usage in future investigation of photonic integrated circuits

Case Report: Persistent left superior vena cava: an incidental finding during peripherally inserted central catheter placement

BackgroundA peripherally inserted central catheter (PICC) is a specialized type of long-term intravenous catheter commonly employed for administering chemotherapy. The operation and management of PICC should exclusively be carried out by trained healthcare professionals equipped with the requisite knowledge of anatomy, procedural technique and patient care. Persistent left superior vena cava (PLSVC) is a vascular malformation which is typically asymptomatic in clinical presentation, almost always identified during invasive surgery or imaging examinations.Case presentationHerein, we detailed a case involving a breast cancer patient whose PLSVC was identified during the placement of PICC because of the negative P-wave in electrocardiogram (ECG). Subsequent examination, including chest x-ray imaging, postoperative enhanced CT of the chest, ECG, and consultation with an experienced imaging physician confirmed that the patient's variant type was PLSVC type I. 2160. Removal of the catheter was deemed unnecessary, as the catheter tip was appropriately positioned and no other concomitant cardiovascular malformations were detected.ConclusionThe PLSVC is a vascular anomaly and is relatively uncommon within the general population. The operator should possess a thorough familiarity with the potential anatomical variations of left superior vena cava, and specialized case profile should be established for patients diagnosed with PLSVC

Prevalence survey on pterygium among people aged 40 and above in Hengli Town of Dongguan

AIM:To investigate the prevalence of pterygium of the household population aged 40 and above in Hengli Town of Dongguan.<p>METHODS: Using the method of cluster random sampling, select 3 628 people aged 40 and above in four villages and one community for visual examination, intraocular pressure check, slit lamp examination and questionnaire.<p>RESULTS: The actual number of subjects was 3 393 people, and examination rate was 93.52%. We detected 843 patients with pterygium. The prevalence of pterygium was 24.85%.<p>CONCLUSION: There is high prevalence of pterygium in Dongguan area. The prevalence of pterygium is related with age and working environment, but has no relation with gender

Movable Fiber-Integrated Hybrid Plasmonic Waveguide on Metal Film

A waveguide structure consisting of a tapered nanofiber on a metal film is proposed and analyzed to support highly localized hybrid plasmonic modes. The hybrid plasmonic mode can be efficiently excited through the in-line tapered fiber based on adiabatic conversion and collected by the same fiber, which is very convenient in the experiment. Due to the ultrasmall mode area of plasmonic mode, the local electromagnetic field is greatly enhanced in this movable waveguide, which is potential for enhanced coherence light emitter interactions, such as waveguide quantum electrodynamics, single emitter spectrum and nonlinear optics

Magnetic Borophenes from an Evolutionary Search

A computational methodology based on ab initio evolutionary algorithms and spin-polarized density functional theory was developed to predict two-dimensional magnetic materials. Its application to a model system borophene reveals an unexpected rich magnetism and polymorphism. A metastable borophene with nonzero thickness is an antiferromagnetic semiconductor from first-principles calculations, and can be further tuned into a half-metal by finite electron doping. In this borophene, the buckling and coupling among three atomic layers are not only responsible for magnetism, but also result in an out-of-plane negative Poisson\u27s ratio under uniaxial tension, making it the first elemental material possessing auxetic and magnetic properties simultaneously