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Palmprints are a recognizable biometric feature that contains multimodal information. Contact-based high-resolution palmprints are the most commonly used image in automatic palmprint identification systems with high-level security requirements because of its high matching accuracy and robustness. Currently, the traditional contact-based high-resolution palmprint acquisition system only captures the total internal reflection (TIR) image, which is similar to fingerprint acquisition systems. However, it is worth noting that the palm is much larger than the finger, and different regions of the palm cannot be easily pressed to the same plane. We observed that the images obtained by these existing contact-based high-resolution palmprint image acquisition systems often have poor integrity and sharpness, especially in the center of the palm. Considering this problem, we proposed an improved contact-based high-resolution palmprint image acquisition system. In addition to the TIR image, it can also simultaneously acquire a diffuse reflection (DR) image. A high-resolution DR image has low contrast and is thus not suitable for direct identification. However, the high integrity and sharing of structural information with the TIR image make it possible to complement the TIR image. Our strategy is to transfer the DR image to the TIR domain through a convolution neural network (CNN) and then fuse it with the corresponding TIR image to obtain a higher quality TIR domain image. The partial-to-“full” identification experimental results show that the rank-1 accuracy of the fused TIR (FTIR) image is improved by approximately 23% compared with the traditional TIR image, which proves the effectiveness of our strategy.

Background: Tuberculosis and lung cancer are common high-mortality lung diseases, but it is rare that lung cancer and tuberculosis exist in the same lesion. In addition, lung cancer with pulmonary tuberculosis is similar in morphology to lung cancer without tuberculosis. For these reasons, lung cancer patients with tuberculosis are often misdiagnosed and mistreated, so these patients have a poorer prognosis than lung cancer patients without tuberculosis. Therefore, a full understanding of such cases can help early diagnosis, so that appropriate treatments can be performed timely. Case presentations: A 52-year-old male. The physical examination revealed a cavity-like nodule in the upper left lung and the first diagnosis was tuberculosis. There was no significant change in lung nodules after anti-tuberculosis treatment. So the patient was admitted to the hospital for surgical treatment of lung cancer. Postoperative pathological showed that the lesion was lung squamous cell carcinoma with tuberculosis.Conclusion: the survival rate of patients with active pulmonary tuberculosis and lung cancer is lower than those with lung cancer or tuberculosis alone. Which is mainly due to incomplete diagnosis. if we find hollow shadows in the lungs on CT, we should think about the possibility of coexistence of lung cancer and tuberculosis, and then the appropriate treatment and management strategies should be developed.

Perovskite nanocrystals (PNCs) have emerged as highly promising optical gain materials for laser applications. Despite the recent surge of reports on their lasing performance, it remains a challenge to achieve PNCs-based single-mode vertical cavity surface emitting lasers (VCSELs) because of their inhomogeneous gain saturation. Here, we successfully demonstrate high performance single-mode VCSELs using CsPbBr3 PNCs that were synthesized via a facile ligand-assisted reprecipitation strategy. The optical gain medium with wide crystal size range was fabricated, and the dense assembly of each individual PNCs was expected to offer a homogeneous optical continuum to reduce gain saturation inhomogeneity. The fabricated VCSELs exhibit excellent single-mode lasing at ~541 nm without mode hopping and high spontaneous emission coupling factor of ~0.24, which is one order of magnitude higher than those of nitride-based VCSELs. Through streak camera direct observations, the stimulated emission of the laser device exhibits an ultrafast decay of ~10 ps, and the electron hole plasma (EHP) mechanism is considered responsible for stimulated emission in the VCSELs. This work paves the way toward next-generation high performance PNC-based single-mode laser devices with reduced fabrication cost for practical application.

All-inorganic perovskite micro/nanolasers are emerging as a class of miniaturized coherent photonic sources for many potential applications, such as optical communication, computing, and imaging, owing to their ultracompact sizes, highly localized coherent output, and broadband wavelength tunability. However, to achieve single-mode laser emission in the microscale perovskite cavity is still challenging. Herein, we report unprecedented single-mode laser operations at room temperature in self-assembly CsPbX 3 microcavities over an ultrawide pumping wavelength range of 400–2300 nm, covering one- to five-photon absorption processes. The superior frequency down- and upconversion single-mode lasing manifests high multiphoton absorption efficiency and excellent optical gain from the electron–hole plasma state in the perovskite microcavities. Through direct compositional modulation, the wavelength of a single-mode CsPbX 3 microlaser can be continuously tuned from blue-violet to green (427–543 nm). The laser emission remains stable and robust after long-term high-intensity excitation for over 12 h (up to 4.3 × 10 7 excitation cycles) in the ambient atmosphere. Moreover, the pump-wavelength dependence of the threshold, as well as the detailed lasing dynamics such as the gain-switching and electron–hole plasma mechanisms, are systematically investigated to shed insight into the more fundamental issues of the lasing processes in CsPbX 3 perovskite microcavities.

Obtaining whispering gallery mode (WGM) lasing with prominent stability and high quality optical cavities is extremely desirable but still a great challenge. Despite the recent surge of reports on microspheres, nanowires and nanoplatelets metal halide crystals, there has few reports on the morphology of Hemispheres (HSs) in the form of uniform, component-tunable microcrystals. Here, CsPbX3 (X = Cl/Br) HSs with smooth surface and regular geometry structure were synthesized on silicon substrates by chemical vapor deposition (CVD) method, and the wavelength of laser can be continuously tuned from blue to green (450–540 nm) at room temperature by varying the halide composition. WGM laser with polarization ratio of 0.70 and cavity quality factor Q of 2485 were realized in the CsPbBr3 HS cavity. Besides, the crystal cavity suggested a high photonic and thermal stability for the superb capability of continuous stable lasing output under ambient conditions. All these results illustrate that the synthesis of cesium lead halide perovskite HSs may provide an alternative solution for fundamental researches and applications in optical devices.