246 research outputs found

    Anti-parity-time symmetry hidden in a damping linear resonator

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    Phase transition from the over-damping to under-damping states is a ubiquitous phenomenon in physical systems. However, what kind of symmetry is broken associated with this phase transition remains unclear. Here, we discover that this phase transition is determined by an anti-parity-time (anti-PT\mathcal{PT}) symmetry hidden in a single damping linear resonator, which is significantly different from the conventional anti-PT\mathcal{PT}-symmetric systems with two or more modes. We show that the breaking of the anti-PT\mathcal{PT} symmetry yields the phase transition from the over-damping to under-damping states, with an exceptional point (EP) corresponding to the critical-damping state. Moreover, we propose an optomechanical scheme to show this anti-PT\mathcal{PT} symmetry breaking by using the optical spring effect in a quadratic optomechanical system. We also suggest an optomechanical sensor with the sensitivity enhanced significantly around the EPs for the anti-PT\mathcal{PT} symmetry breaking. Our work unveils the anti-PT\mathcal{PT} symmetry hidden in damping oscillations and hence opens up new possibilities for exploiting wide anti-PT\mathcal{PT} symmetry applications in single damping linear resonators.Comment: 12 pages, 6 figures, Research Highlight by Prof. Cheng-Wei Qiu: https://www.sciengine.com/SCPMA/doi/10.1007/s11433-023-2195-

    A prospective study of age trends of high-risk human papillomavirus infection in rural China

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    BACKGROUND: In China, high-risk human papillomavirus (HR-HPV) prevalence is unexpectedly high in older women, but the possible reasons have not been well studied yet. This study investigated the age trends of HR-HPV infection in a prospective study. METHODS: A total of 7397 women aged 25-65 years without cervical precancer or cancer were evaluated during 2010-2011 with a stratified sample of 2791 women re-evaluated after one year. Test results for careHPV and careHPV16/18/45 were used to describe the HR-HPV prevalence, incidence and clearance. Risk factors associated with HR-HPV infections were explored using a logistic regression model. RESULTS: The overall HR-HPV prevalence was 13.1% at baseline, with a peak of 19.3% in women aged 55-59 years. The prevalence of HR-HPV (p for trends < 0.001), HPV16/18/45 (p for trends = 0.002), and HR-HPV other than HPV16/18/45 (p for trends = 0.002) generally increased with increasing age. Number of infections that cleared was generally greater than number of incident infections within age groups. One-year clearance rate decreased with increasing age (p for trends < 0.001), however, incidence rate was unrelated to age (p for trends = 0.159). Risk factors that associated with HR-HPV infection differed between younger and older women. CONCLUSIONS: The greater HR-HPV prevalence in older versus younger women in rural China may be explained by a cohort effect, higher than expected incidence, and/or poorer clearance at older age

    Accuracy of triage strategies for human papillomavirus DNA-positive women in low-resource settings: A cross-sectional study in China

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    CareHPV is a human papillomavirus (HPV) DNA test for low-resource settings (LRS). This study assesses optimum triage strategies for careHPV-positive women in LRS

    Micropathogen community analysis in Hyalomma rufipes via high-throughput sequencing of small RNAs

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    Ticks are important vectors in the transmission of a broad range of micropathogens to vertebrates, including humans. Because of the role of ticks in disease transmission, identifying and characterizing the micropathogen profiles of tick populations have become increasingly important. The objective of this study was to survey the micropathogens of Hyalomma rufipes ticks. Illumina HiSeq2000 technology was utilized to perform deep sequencing of small RNAs (sRNAs) extracted from field-collected H. rufipes ticks in Gansu Province, China. The resultant sRNA library data revealed that the surveyed tick populations produced reads that were homologous to St. Croix River Virus (SCRV) sequences. We also observed many reads that were homologous to microbial and/or pathogenic isolates, including bacteria, protozoa, and fungi. As part of this analysis, a phylogenetic tree was constructed to display the relationships among the homologous sequences that were identified. The study offered a unique opportunity to gain insight into the micropathogens of H. rufipes ticks. The effective control of arthropod vectors in the future will require knowledge of the micropathogen composition of vectors harboring infectious agents. Understanding the ecological factors that regulate vector propagation in association with the prevalence and persistence of micropathogen lineages is also imperative. These interactions may affect the evolution of micropathogen lineages, especially if the micropathogens rely on the vector or host for dispersal. The sRNA deep-sequencing approach used in this analysis provides an intuitive method to survey micropathogen prevalence in ticks and other vector species

    Spontaneous activities in baroreflex afferent pathway contribute dominant role in parasympathetic neurocontrol of blood pressure regulation

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    Aim To study the dominant role of parasympathetic inputs at cellular level of baroreflex afferent pathway and underlying mechanism in neurocontrol of blood pressure regulation. Methods Whole‐cell patch‐clamp and animal study were conducted. Results For the first time, we demonstrated the spontaneous activities from resting membrane potential in myelinated A‐ and Ah‐type baroreceptor neurons (BRNs, the 1st‐order), but not in unmyelinated C‐types, using vagus‐nodose slice of adult female rats. These data were further supported by the notion that the spontaneous synaptic currents could only be seen in the pharmacologically and electrophysiologically defined myelinated A‐ and Ah‐type baroreceptive neurons (the 2nd‐order) of NTS using brainstem slice of adult female rats. The greater frequency and the larger amplitude of the spontaneous excitatory postsynaptic currents (EPSCs) compared with the inhibitory postsynaptic currents (IPSCs) were only observed in Ah‐types. The ratio of EPSCs:IPSCs was estimated at 3:1 and higher. These results confirmed that the afferent‐specific spontaneous activities were generated from baroreflex afferent pathway in female‐specific subpopulation of myelinated Ah‐type BRNs in nodose and baroreceptive neurons in NTS, which provided a novel insight into the dominant role of sex‐specific baroreflex‐evoked parasympathetic drives in retaining a stable and lower blood pressure status in healthy subjects, particularly in females. Conclusion The data from current investigations establish a new concept for the role of Ah‐type baroreceptor/baroreceptive neurons in controlling blood pressure stability and provide a new pathway for pharmacological intervention for hypertension and cardiovascular diseases
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