Retroreflection from a single layer of electromagnetic Helmholtz cavities based on magnetic symmetric dipole modes.

We demonstrate a new electromagnetic mode which is formed by the dynamic interaction between a magnetic quadrupole mode and an electric monopole mode in a two-dimensional electromagnetic Helmholtz cavity. It is termed a magnetic symmetric dipole mode since it shares similarity with a magnetic dipole mode in the sense that their radiation is both overwhelmingly dominant in the forward and backward directions with respect to the incident wave. However, the phase distribution in the two radiation directions is symmetric, in stark contrast to the antisymmetry of magnetic dipole modes. When the Helmholtz cavities are arranged in a line, the incident wave will be reflected back to the source, in other words, retroreflection occurs because of the peculiar properties of magnetic symmetric dipole modes. We show that the retroreflection is quite robust against the disorder of the orientation angle of Helmholtz cavities and there exists a wide tolerance for wavelength and the outer radius of the cavity. With low fabrication demands, this might offer a feasible solution for the design of ultrathin retroreflectors towards device miniaturization and the realization of multiplexing holography.

Misdiagnosis of pneumorrhagia leptospirosis as common CAP: A case report and literature review.

Background: The incidence of critical leptospirosis manifested as massive pulmonary hemorrhage has been significantly reduced, which has been rarely reported in recent years, while the mortality rate is extremely high once it occurs. Case presentation: A 54-year-old man with no HIV infection was admitted to the local county hospital due to high-grade continuous fever lasting four days (38.5-40.5C), upper limb and shoulder-back muscle pain, and general fatigue. The chest CT (Aug 26, 2021) showed "multiple patchy, cloudy, and fuzzy shadows in both lungs, mainly under the pleura of the upper and lower lobes of both lungs; some lymph nodes in the mediastinum are enlarged". Despite being diagnosed with "common community-acquired pneumonia" and starting injectable levofloxacin, the symptoms worsened, and massive hemoptysis occurred. However, after being transferred to our hospital, the patient was diagnosed with the "pulmonary hemorrhage type of leptospirosis" through comprehensive dynamic analysis. The patient recovered very well after undergoing "penicillin 3MIU q6h" alone for two weeks to fight the infection. Conclusions: Leptospirosis has a high mortality rate when it becomes critical or severe. Diagnosis typically relies on factors such as epidemiology, clinical symptoms, and pathogenetic testing. Metagenomic next-generation sequencing (mNGS) is more effective in sensitivity and speed than traditional detection methods, making it an excellent option for diagnosing challenging and severe infections in emergencies. Additionally, when experiencing sudden coughing up of blood, it's important to consider the possibility of pulmonary hemorrhage as a type of leptospirosis.

Corrigendum: Metformin Ameliorates Inflammation and Airway Remodeling of Experimental Allergic Asthma in Mice by Restoring AMPKα Activity.

[This corrects the article DOI: 10.3389/fphar.2022.780148.].

Metformin Ameliorates Inflammation and Airway Remodeling of Experimental Allergic Asthma in Mice by Restoring AMPKα Activity.

Metformin has been involved in modulating inflammatory state and inhibiting cell proliferation and angiogenesis. This study aimed to determine whether metformin alleviates airway inflammation and remodeling of experimental allergic asthma and elucidate the underlying mechanism. We sensitized and challenged mice with ovalbumin (OVA) to induce allergic asthma. During the challenge period, metformin was administered by intraperitoneal injection. By histopathological and immunohistochemical analyses, metformin-treated mice showed a significant alleviation in airway inflammation, and in the parameters of airway remodeling including goblet cell hyperplasia, collagen deposition and airway smooth muscle hypertrophy compared to those in the OVA-challenged mice. We also observed elevated levels of multiple cytokines (IL-4, IL-5, IL-13, TNF-α, TGF-ß1 and MMP-9) in the bronchoalveolar lavage fluid, OVA-specific IgE in the serum and angiogenesis-related factors (VEGF, SDF-1 and CXCR4) in the plasma from asthmatic mice, while metformin reduced all these parameters. Additionally, the activity of 5'-adenosine monophosphate-activated protein kinase a (AMPKα) in the lungs from OVA-challenged mice was remarkably lower than control ones, while after metformin treatment, the ratio of p-AMPKα to AMPKα was upregulated and new blood vessels in the sub-epithelial area as evidenced by CD31 staining were effectively suppressed. These results indicate that metformin ameliorates airway inflammation and remodeling in an OVA-induced chronic asthmatic model and its protective role could be associated with the restoration of AMPKα activity and decreased asthma-related angiogenesis.

Concentration and integrity indexes of urine cell-free DNA as promising biomarkers for early lung cancer diagnosis.

Aim: To explore the role of urine cell-free DNA (ucfDNA) concentration and integrity indexes as potential biomarkers for lung cancer diagnosis. Materials & methods: Quantitative real-time PCR targeting Arthrobacter luteus (ALU) repeats at three size fragments (ALU-60, 115 and 247 bp) was performed in 55 lung cancer patients and 35 healthy individuals. Results: ucfDNA concentration and integrity indexes were significantly higher in lung cancer patients than in healthy controls. The area under the receiver operating characteristic curve for differentiating patients with stage I/II from healthy controls by ALU fragments concentration were 0.856, 0.909 and 0.932, respectively. In addition, the ucfDNA integrity indexes in patients with lymph node metastasis were significantly higher than in patients with non-metastatic. Conclusion: ucfDNA concentration and integrity indexes could serve as promising biomarkers for lung cancer diagnosis.

Sensitive detection of low-abundance in-frame deletions in EGFR exon 19 using novel wild-type blockers in real-time PCR.

Epidermal growth factor receptor (EGFR) mutations are associated with response of tyrosine kinase inhibitors (TKIs) for patients with advanced non-small cell lung cancer (NSCLC). However, the existing methods for detection of samples having rare mutations(i.e. ~0.01%) have limits in terms of specificity, time consumption or cost. In the current study, novel wild-type blocking (WTB) oligonucleotides modified with phosphorothioate or inverted dT at the 5'-termini were designed to precisely detect 11 common deletion mutations in exon 19 of EGFR gene (E19del) using a WTB-PCR assay. And internal competitive leptin amplifications were further applied to enhance the specificity of the WTB-PCR system. Our results showed that WTB-PCR could completely block amplification of wild-type EGFR when 200 ng of DNA was used as template. Furthermore, the current WTB-PCR assay facilitated the detection of E19del mutations with a selectivity of 0.01% and sensitivity as low as a single copy. And, the results showed that the current WTB-PCR system exceeded detection limits afforded by the ARMS-PCR assay. In conclusion, the current WTB-PCR strategy represents a simple and cost-effective method to precisely detect various low-abundance deletion mutations.