Search

Low-dimensional nanostructures, especially one-dimensional materials, exhibit remarkable anisotropic characteristics due to their low symmetry, making them promising candidates for polarization-sensitive photodetection. Here, we present a chemical vapor deposition synthesis method for tellurium suboxide (TeOx), confirming the practicality of photodetectors constructed from TeOx nanowires (NWs) in high-responsivity, broadband, and polarization-sensitive detection. By precisely controlling the thermodynamics and kinetics of TeOx NWs growth, we achieve large-scale growth of TeOx NWs with highly controllable dimensions and propose a method to induce intrinsic built-in strain in TeOx NWs. Photodetectors based on quasi-one-dimensional TeOx NWs with ohmic contact demonstrate broadband spectral response (638–1550 nm), high responsivity (13 700 mA·W−1), and superior air stability. Particularly, owing to the inherent structural anisotropy of the photodetectors, they exhibit polarization-sensitive photodetection, with anisotropy ratios of 1.70 and 1.71 at 638 and 808 nm, respectively. [ABSTRACT FROM AUTHOR]

AIM: To explore the clinical features, diagnosis and treatment experience and the distribution characteristics of pathogenic microorganisms of primary canaliculitis, and provide reference for its diagnosis and treatment. METHODS: Retrospective clinical study. A total of 119 cases(120 eyes)diagnosed as primary canaliculitis in the department of ophthalmology of Wuxi No.2 People's Hospital from June 2019 to February 2023 were included. The treatment methods were mainly divided into conservative treatment(removing canaliculus stones through lacrimal punctum combined with injecting antibiotic eye ointment into the tube)and surgical treatment. The inspection methods of pathogenic microorganisms included secretion smear microscopy and microbial culture.RESULTS: Primary canaliculitis was more common in middle-aged and older female, mainly manifested by long-term red eye and increased secretion; however, the majority was not accompanied by tearing. Totally, 118 cases(99.2%)had monocular disease, while 63 cases(63 eyes; 52.5%)had inferior lacrimal canaliculus disease. Laboratory examination: Among 119 cases(120 eyes), 4 cases(4 eyes)did not undergo laboratory examination, and the other 115 cases(116 eyes)were as follows: Gram staining microscopy of secretion smear showed that Actinomyces were detected in 102 cases(103 eyes; 88.8%), while no fungus was detected; Microbial culture: 85 cases(86 eyes; 74.1%)were positive for bacterial culture. A total of 111 bacterial strains were cultured, which contained 26 types of bacteria. Among them, 32 strains were aerobic(28.8%); 26 strains were anaerobic(23.4%); and 53 strains were facultative anaerobic(47.7%). The most common bacteria were streptococcus(20 strains), staphylococcus(13 strains), Propionibacterium(10 strains), and capnocytophaga(10 strains). Only 4 cases(4 eyes; 3.4%)of microbial cultures were positive for Actinomyces. Fungus was negative in all microbial cultures. Treatment: Of the 119 cases(120 eyes), 114 cases(115 eyes; 95.8%)were cured by conservative treatment of removing lacrimal canaliculus stones through lacrimal punctum and intracanalicular ointment infiltration(IOI), while 5 cases(5 eyes)were not effective in conservative treatment; however, all of them were cured after surgical treatment, and the cure rate for primary canaliculitis was 100.0%.CONCLUSION: The incidence of primary canaliculitis is low, and it is prevalent in middle-aged and older female. Single lacrimal canaliculus is more common, which could be missed and misdiagnosed in clinic. Actinomyces is the major pathogen observed mostly in mixed infections, with heterogeneous strains, mainly anaerobic or facultative anaerobic bacteria. Streptococcus and Staphylococcus are the most common whereas fungal canaliculitis is rare. The cure rate of primary canaliculitis is high after diagnosis, and IOI method is recommended as the initial treatment of canaliculitis.

In this study, we experimentally showcase the microfiber evanescent-field photothermal gas detection by exploiting all-fiber MHz-level frequency shift scheme. Based on the acousto-optic interaction effect, the low-frequency shifts of 0.9 MHz and 1.83 MHz can be obtained through the cyclic conversion between the transverse core modes LP01 and LP11 in the few-mode fiber. Our proposed all-fiber frequency shifters show flexible MHz-level up(down) frequency shifts with superior sideband rejection ratio (over 40 dB) and low insertion loss (less than 1 dB). Furthermore, an all-fiber heterodyne interferometric detection system is implemented by leveraging the above low-frequency shifters, in which around 1-μm-diameter microfiber is investigated for photothermal gas detection. A pump-probe configuration is employed to obtain the photothermal effect induced by the gas absorption of the modulated evanescent field. By demodulating the phase of the beat signal output by the interferometer, an equivalent detection limit (1σ) of 32 ppm and a response time of 22 s are achieved for ammonia, as well as 0.24 % instability within 48 pump cycles. Given its compact all-fiber configuration and high sensitivity with fast response, the experimental results can pave the way for widespread applications like heterodyne detection, fiber optical sensors, and interplanetary coherent communications.

In atomically-thin two-dimensional (2D) semiconductors, the nonuniformity in current flow due to its edge states may alter and even dictate the charge transport properties of the entire device. However, the influence of the edge states on electrical transport in 2D materials has not been sufficiently explored to date. Here, we systematically quantify the edge state contribution to electrical transport in monolayer MoS2/WSe2 field-effect transistors, revealing that the charge transport at low temperature is dominated by the edge conduction with the nonlinear behavior. The metallic edge states are revealed by scanning probe microscopy, scanning Kelvin probe force microscopy and first-principle calculations. Further analyses demonstrate that the edge-state dominated nonlinear transport shows a universal power-law scaling relationship with both temperature and bias voltage, which can be well explained by the 1D Luttinger liquid theory. These findings demonstrate the Luttinger liquid behavior in 2D materials and offer important insights into designing 2D electronics.