Hepatitis B virus （HBV） exclusively infects liver parenchymal cells and forms covalently closed circular DNA （cccDNA） within their nuclei. HBV cccDNA serves as the essential template for viral gene transcription， the sole source of progeny virus production， and the key driver of viral antigen expression， and it is the molecular basis for the persistence of HBV infection. Therefore， elimination and/or functional silencing of cccDNA is the key to eradicate chronic HBV infection. This article discusses the critical scientific issues that need to be solved during elimination of the harm of HBV infection from the perspectives of the synthesis， transcription， and clearance of cccDNA， as well as the impact of nonparenchymal cells on cccDNA， in order to provide a reference for eradicating HBV infection in the future.

Background The decline of physical activity in the elderly due to aging may increase the risk of sarcopenia. Currently, there is a lack of evidence from large natural populations on the relationship between PA and sarcopenia. Objective To explore the relationship between PA and sarcopenia in the elderly aged 60 years and above in 10 provinces (autonomous regions) of China. Methods Data were retrieved from the 2022—2023 round of the China Development and Nutrition Health Impact Cohort. Personal basic information and PA data were collected by questionnaire survey. Skeletal muscle mass was measured by bio-electrical impedance analysis, muscle strength was measured using a grip dynamometer, and physical performance was reflected by 6-meter walk speed. The Asian Working Group for Sarcopenia (AWGS) 2019 criteria were used to diagnose sarcopenia. Light physical activity (LPA) duration, moderate-to-vigorous physical activity (MVPA) duration, and total physical activity volume were calculated. A total of 3326 residents aged ≥60 years with complete data were selected as the survey participants. Multiple logistic regression models and restricted cubic splines (RCS) were used to assess the association between PA duration/volume and sarcopenia. Results In 10 provinces (autonomous regions) of China, the prevalence of sarcopenia in the elderly aged 60 years and above was 5.5% (95%CI: 4.7%, 6.2%). The logistic regression analysis showed that compared with the elderly reporting 0-7.0 h·week⁻¹ in LPA duration, the risk of sarcopenia in the elderly with LPA duration of >14.0-21.0 h·week⁻¹ was reduced by 51% (OR=0.49, 95%CI: 0.26, 0.96). Compared with the elderly with total physical activity ≥15.0 metabolic equivalent of task (MET)-h·week⁻¹, those with <7.5 MET-h·week⁻¹ had a 2.24-fold increased risk of sarcopenia (OR=2.24, 95%CI: 1.17, 4.29). The RCS results found that LPA duration and total physical activity volume each showed a nonlinear dose-response relationship with the risk of sarcopenia (P_overall<0.05, P_non-linear<0.05). Compared with the elderly with an LPA duration of 0 h· week⁻¹, the risk of sarcopenia in the elderly with an LPA duration of 12.6 h· week⁻¹ was the lowest (OR=0.42, 95%CI: 0.21, 0.83). Compared with the elderly with a total physical activity volume of 15.0 MET-h· week⁻¹, the elderly with a total physical activity volume of 46.0 MET-h· week⁻¹ had the lowest risk of sarcopenia (OR=0.57, 95%CI: 0.38, 0.84). There was no statistically significant association between weekly MVPA duration and the risk of sarcopenia (P>0.05). Conclusion Increasing weekly LPA duration and total physical activity volume would help to reduce the risk of sarcopenia.

The risk prediction of paroxysmal atrial fibrillation (PAF) is a challenge in the field of biomedical engineering. This study integrated the advantages of machine learning feature engineering and end-to-end modeling of deep learning to propose a PAF risk prediction method based on multimodal feature fusion. Additionally, the study utilized four different feature selection methods and Pearson correlation analysis to determine the optimal multimodal feature set, and employed random forest for PAF risk assessment. The proposed method achieved accuracy of (92.3 ± 2.1)% and F1 score of (91.6 ± 2.9)% in a public dataset. In a clinical dataset, it achieved accuracy of (91.4 ± 2.0)% and F1 score of (90.8 ± 2.4)%. The method demonstrates generalization across multi-center datasets and holds promising clinical application prospects.
Humans ; Atrial Fibrillation/diagnosis* ; Machine Learning ; Deep Learning ; Risk Assessment/methods*

Automatic classification of medical questions is of great significance in improving the quality and efficiency of online medical services, and belongs to the task of intent recognition. Joint entity recognition and intent recognition perform better than single task models. Currently, most publicly available medical text intent recognition datasets lack entity annotation, and manual annotation of these entities requires a lot of time and manpower. To solve this problem, this paper proposes a medical text classification model, bidirectional encoder representation based on transformer-recurrent convolutional neural network-entity-label-semantics (BRELS), which integrates medical entity label semantics. This model firstly utilizes an adaptive fusion mechanism to absorb prior knowledge of medical entity labels, achieving local feature enhancement. Then in global feature extraction, a lightweight recurrent convolutional neural network (LRCNN) is used to suppress parameter growth while preserving the original semantics of the text. The ablation and comparison experiments are conducted on three public medical text intent recognition datasets to validate the performance of the model. The results show that F1 score reaches 87.34%, 81.71%, and 77.74% on each dataset, respectively. The results show that the BRELS model can effectively identify and understand medical terminology, thereby effectively identifying users' intentions, which can improve the quality and efficiency of online medical services.
Semantics ; Neural Networks, Computer ; Humans ; Natural Language Processing

Objective To explore the effects of nicotinamide mononucleotide （NMN） on hypertensive rats. Methods Two rat hypertension models including spontaneously hypertensive rats（SHR）and two-kidney two-clip （2K2C） rats were used to be given single, long-term or lifelong administration of NMN respectively. NMN’s effects were assessed comprehensively by monitoring survival time, blood pressure levels, and the extent of organ damage in hypertensive model rats. Results It was revealed that NMN did not exhibit protective effects in terms of lowering blood pressure levels, reducing organ damage or increasing survival time in hypertensive rats. Conclusion This study suggested that NMN did not demonstrate anti-hypertensive effects in rat hypertension models and could provide valuable insights for future clinical observation on NMN.

Chronic obstructive pulmonary disease(COPD)often leads to disease progression due to"inflammation extravasation"and development to the whole body"weakness".Professor Miao Qing believes that"disorder of qi movement,impairment of the descending function of the lung"is the key pathogenesis of COPD,and proposes the method of"mediating triple energizers and tonifying three qi"to treat COPD,that is,based on upper energizer-pectoral qi-heart and lung qi,middle energizer-middle qi-spleen-stomach qi,lower energizer-primordial qi-kidney qi and kidney essence,respectively,"raising pectoral qi,nourishing upper energizer heart and lung","cultivating and nourishing middle qi,balancing the spleen and stomach of middle energizer","reinforcing the primordial qi,collecting and absorbing the kidney essence of lower energizer",and achieved good efficacy.

Central nerve injuries, most commonly caused by traffic accidents or falls, frequently result in irreversible deficits such as paralysis, cognitive impairment and respiratory failure, profoundly impairing patients′ life quality and even proving to be fatal. Current therapeutic strategies including early surgical decompression, corticosteroid administration and neurotrophic pharmacotherapy fail to restore the neuro-homeostatic balance and systemic function. In recent years, biomaterial-based interventions have emerged as a promising alternative for central nerve injuries. Among them, the human amniotic membrane (HAM), a placental basement-membrane scaffold rich in collagen, hyaluronic acid and a cocktail of growth factors, perfectly combines angiogenic, anti-fibrotic and neurotropic properties that meet the complex demands of central nerve repair. Nevertheless, HAM-based therapies for central nerve injuries remain at an early stage of pre-clinical investigation. In the meantime, most studies have simply translated protocols validated for peripheral nerve injuries without addressing the pathological microenvironment specific to central nerve injuries. To this end, the authors reviewed recent advances in the modes of HAM application for central nerve injuries, aiming to provide novel insights and reference for future research on central nerve injuries.

Objective:To evaluate the diagnostic value of targeted next-generation sequencing (tNGS) of throat swab samples for detecting community-acquired respiratory viruses (CARV) in patients with hematological diseases.Methods:Clinical and laboratory data from 64 episodes involving patients with hematological diseases and suspected infections—who underwent both pharyngeal swab tNGS and CARV polymerase chain reaction (PCR) testing concurrently—were retrospectively analyzed. The cases were drawn from the Department of Hematology, Peking University People’s Hospital, between September 2023 and April 2024. Concordance between tNGS and CARV PCR results, as well as the diagnostic performance of tNGS in detecting CARV, were evaluated.Results:Among the 64 episodes, 29 were clinically diagnosed with respiratory tract infections, including one case of cytomegalovirus pneumonia and 28 CARV-positive cases. The remaining 35 episodes involved patients with fever or respiratory symptoms attributed to other causes, including 14 with extrapulmonary infections and 21 with noninfectious etiologies. The median follow-up duration was 215.5 days (range: 7-271 days). PCR detected 24 strains of seven CARV types, whereas tNGS detected 25 strains of eight CARV types. Using PCR results as the reference standard, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of tNGS were 85.0%, 88.6%, 77.3%, 92.9%, and 87.5%, respectively. The two methods showed good concordance (Kappa=0.717, P<0.001) . Conclusion:Pharyngeal swab tNGS may serve as a viable alternative to PCR for diagnosing CARV infections in patients with hematological diseases.

Objective:To explore the clinical characteristics and healthcare burden in patients with McCune-Albright syndrome (MAS).Methods:A cross-sectional study was conducted at the Children′s Hospital, Zhejiang University School of Medicine. Clinical and healthcare burden data were systematically collected through structured questionnaires in 164 children with MAS from February 2022 to May 2023. According to the clinical characteristics, patients were categorized into 3 groups: monosymptomatic, bisymptomatic and trisymptomatic groups. Patients were also divided into 3 groups according to the age of <7, 7-<10 and 10-18 years. Comparative analyses of clinical characteristics and healthcare burden were conducted across age, sex, and symptom categories.Results:The cohort comprised 59 males (36.0%) and 105 females (64.0%) with an age of 4.6 (2.0, 7.4) years. Age stratification revealed 117 cases (71.3%) aged 0-<7 years, 29 cases (17.7%) aged 7-<10 years, and 18 cases (11.0%) aged 10-<18 years. Among monosymptomatic (67 cases, 40.9%), the cohort comprised 32 females (47.8%) and 35 males (52.2%), predominantly presenting with fibrous dysplasia (57 cases, 85.1%). This subgroup showed peak prevalence in the 0-<7 years age range (29 cases (50.9%)). The bisymptomatic cohort (56 cases, 34.1%) consisted of 39 females (69.6%) and 17 males (30.4%), predominantly manifesting fibrous dysplasia with skin hyperpigmentation (25 cases, 44.6%). Peak prevalence occurred in the 0-<7 years subgroup(16 cases (64.0%)). The trisymptomatic cohort (41 cases, 25.0%) consisted of 34 females (82.9%) and 7 males (17.1%), with peak prevalence occurring in the 0-<7 years subgroup (36 cases (87.8%)). The diagnostic journey analysis revealed 94 cases (57.3%) required 1-3 referrals, and 34 cases (20.7%) necessitated >3 referrals from symptom onset to definitive diagnosis. Healthcare expenditure analysis revealed 69 families (42.1%) incurred direct medical costs of 10 000-100 000 CNY, with 11 families (6.7%) exceeding >100 000 CNY. Direct non-medical costs reached of 10 000-100 000 CNY for 62 families (37.8%) and >100 000 CNY for 4 families (2.4%). Productivity loss affected 58 families (35.4%) at 10 000-100 000 CNY and 8 families (4.9%) above 100 000 CNY during the study period.Conclusion:MAS requires increased attention to skeletal manifestations, especially in children aged 0-<7 years. Moreover, the significant financial burden on families necessitates a society-wide support system.

Traumatic injuries represent the fifth leading cause of death in China and the primary cause of death among young adults. While facial fractures can lead to significant aesthetic and psychological consequences, fractures in the limbs and joints impair functional mobility. In traumatic incidents requiring forensic evaluation, such as traffic accidents or violent conflicts, the type and severity of fractures directly determine injury grading and disability assessment. Consequently, the accurate diagnosis of traumatic fractures is not only a critical medical issue impacting patient management and rehabilitation but also a significant social issue influencing judicial fairness. This article systematically reviews advancements in multi-modal imaging techniques. While conventional X-ray radiography remains a fundamental screening tool, it faces challenges in detecting occult fractures. Multi-slice spiral computed tomography (MSCT), utilizing 3D reconstruction, enables spatial analysis of complex fractures. Magnetic resonance imaging (MRI), with its multi-sequence capabilities, plays an indispensable role in detecting bone marrow edema and assessing concomitant soft tissue injuries. Regarding innovative technologies, dual-energy computed tomography (DECT) employs virtual non-calcium (VNC) techniques for quantitative bone marrow edema analysis; ultra-high-resolution computed tomography (U-HRCT) breaks through imaging limitations of trabecular microarchitecture with a resolution of approximately 10 μm; and 7.0 T ultra-high-field MRI, alongside MRI-based CT-like imaging techniques, advances radiation-free bone structure evaluation. Artificial intelligence (AI) models significantly enhance diagnostic efficiency in fracture detection. Future developments will focus on multi-modal image fusion, the construction of intelligent decision-support systems, and the quantitative functional assessment of bone microstructure, facilitating a paradigm shift from anatomical description to prognostic prediction and realizing the principles of personalized medicine.