Science Progress最新文献

Bacterial meningitis is a severe infection affecting the protective membranes of the brain and spinal cord, with rapidly worsening symptoms that can lead to life-threatening complications. This study presents an autonomous deterministic epidemic model, $S{I}_a{I}_{s}MRS$, to explore the dynamics of bacterial meningitis in a community implementing control strategies like media coverage, early diagnosis, isolation, and treatment. We adjust the transmission probability based on media coverage and calculate the effective reproduction number, $R_{ef}$, which includes contributions from asymptomatic $R_{ef}^a$ and symptomatic individuals $R_{ef}^s$. We derive the basic reproduction number, $R_0$, to characterize initial infection spread and analyze the local stability of infection-free and endemic equilibria, using the Routh-Hurwitz criteria. For global stability, we apply Castillo-Chavez method for the infection-free equilibrium and the Lyapunov functional technique for the endemic equilibrium, after a uniform persistence study. A local sensitivity analysis evaluates the impact of each parameter on the threshold dynamical parameters $R_{ef}^a$ and $R_{ef}^s$. We also explore an optimal control problem using Pontryagin's maximum principle. The paper concludes with numerical simulations that bridge theoretical and numerical findings.

Due to the high frequency of fifth-generation (5G) signals, which leads to an extremely large computational scale when traditional algorithms solve the channel path loss, it is necessary to seek a fast solution method for the 5G channel path loss in substations in order to achieve a fast adaptation of the channel to the signal receiver and to ensure the reception quality of the 5G signals. Aiming at the problem that traditional algorithms suffer from extremely high computational complexity when dealing with the dyadic reflection-diffraction coefficients, a method based on singular value decomposition is proposed to reduce the dimensionality of the channel matrix for solution. Firstly, the ray tube model is used to divide the channel, and the incident angle information within the channel matrix is chunked through the nodes to discard the duplicates and those that contribute very little to the channel path loss. Then, matrix dimensionality reduction is achieved by the singular value decomposition algorithm, and the dimensionality-reduced channel matrix is substituted into the sum-vector inverse wrap-around coefficient solution formula to achieve the fast solution of 5G channel path loss. Finally, a comparison of the computational results of the proposed algorithm with those of the traditional algorithm is carried out by taking the 5G base station antenna of AAU5270E as an example and using the computational results of the experimental measurement data as a benchmark. The results show that the accuracy loss of the method proposed in the paper is only 1.31%, the compression of the data is 84.89, and the order of magnitude of the computation is 10⁵ lower than that of the traditional algorithm. Future research could further integrate real-time channel data to achieve dynamic adaptive optimization, while extending this dimensionality reduction framework to high-dimensional complex channel modeling such as the sixth generation (6G), thereby promoting the continuous development of the algorithm in terms of real-time performance and generalization capability.

With environmental changes and rapid urbanization, Chinese cities face serious challenges such as disrupted water cycles, frequent flooding, and ecological imbalances. Therefore, China launched the Sponge City initiative in 2013, which evolved into a comprehensive, multiobjective urban management system by 2020. This study focuses on Nanning City, using multisource data from 1990 to 2020 and the Patch-generating Land Use Simulation model to examine land-use changes, driving forces, and future scenarios. Results show that: (1) Construction land increased 5.62 times, spreading from the Chaoyang Creek Basin to flat areas in the east and southeast; (2) Cultivated land and woodland contributed 89.13% and 7.65%, respectively, as main sources; (3) Digital Elevation Model, slope, and transportation were key drivers; and (4) Under ecological protection, woodland and grassland expanded, showing that policy can effectively limit urban growth. This study builds a historical-mechanism-scenario framework to support urban planning and ecological resilience in Nanning.

ObjectiveEndovascular recanalization is the preferred treatment for peripheral vascular diseases. This study evaluated the short-term outcomes of endovascular therapy for transplant renal artery stenosis (TRAS) administered based on anatomical foundations and three-dimensional digital subtraction angiography (3D-DSA).MethodsPatients with TRAS treated with endovascular therapy at a single center between October 2022 and October 2023 were retrospectively analyzed. The primary endpoint was the 12-month primary patency rate, defined as uninterrupted vessel patency without reintervention. Secondary endpoints included secondary patency rate (patency maintained after reintervention), blood pressure, and serum creatinine (Scr) levels.ResultsThe study included 23 patients (mean age: 41.1 ± 11.5 years; 9 females). All patients underwent successful plain old balloon angioplasty (POBA); 13 underwent POBA plus balloon-expandable bare-metal stent (BMS) deployment. The procedure-related complication rate was 13.04%. Technical success was defined as <30% residual stenosis with restoration of antegrade flow at completion angiography and was achieved in all cases (100%). The median follow-up was 14.9 ± 2.3 months (range11-19 months). The 12-month primary and secondary patency rates were 86.96% and 100%, respectively. The primary patency rates significantly differed between the POBA + BMS (100%) and POBA-only (70%) groups (P = 0.032). The systolic and diastolic blood pressure, pulse pressure, and Scr levels significantly differed pre- and post-operatively. No stent-related complications occurred.ConclusionsEndovascular treatment of TRAS based on anatomical foundations and 3D-DSA is safe and effective with a high patency rate. POBA with BMS might be a better solution.

The escalating prevalence of diabetes, along with its complications and mortality risks, imposes a substantial disease burden worldwide. The current suboptimal medical conditions and poor self-management among diabetic patients have exacerbated the deterioration of diabetes globally, particularly in economically underdeveloped countries. However, this situation may now be approaching a turning point. With the constantly advancement of intelligent technologies, the widespread adoption of information management systems and the rise of artificial intelligence have made it possible to enhance the efficiency of diabetes treatment and reduce management costs. Therefore, we have reviewed the relevant literature and conducted a narrative review following the guidance of the Scale for the Assessment of Narrative Review Articles (SANRA). The present paper provides a narrative review of research advances from information management to artificial intelligence in the field of diabetes treatment and management, while also discussing the opportunities and challenges in clinical translation and application. The present review offers a conceptual framework to inform future research and development in intelligent diabetes care.

Inconsistent measurement of multimorbidity hinders comparative research and evidence synthesis. To address this, this study is a narrative review, informed by a structured scoping search of three major databases. We synthesized formal expert-consensus studies to identify a foundational core set of conditions that can serve as a pragmatic starting point for improving research comparability. Our synthesis of three expert consensus studies identified a comprehensive core set of 105 consistently recommended condition categories at the International Classification of Diseases, 10th revision (ICD-10) three-digit level. These conditions span 10 major clinical domains, covering key conditions such as ischemic heart disease, diabetes, dementia, and depression. To facilitate application, we mapped this core set to both ICD-10 and preliminary ICD-11 codes. A foundational consensus for measuring multimorbidity is emerging. We propose a "Core-plus-Customization" framework, where the identified core set serves as an evidence-based starting point for research, requiring local adaptation rather than being a prescriptive "minimum dataset." This operationalized core set provides a practical tool to begin standardizing measurement in the field.

The complex paddy field environments of Southern China characterized by fragmented plots and heavy, moist, and soft soils pose a severe challenge to the adaptability of agricultural machinery, representing a key bottleneck to enhancing the quality and efficiency of regional rice production. This study systematically reviews the current state of agricultural machinery in these paddy fields, with a focus on comparing the performance of wheeled and tracked chassis during key operations like tillage, transplanting, and harvesting. A significant performance trade-off is identified: tracked machinery exhibits superior trafficability and stability on soft, wet surfaces, whereas wheeled equipment offers advantages in maneuverability and cost-effectiveness. However, current equipment faces three core challenges: functional specialization, potential for crop root damage during operation, and a decoupling of machinery and agronomy. Prospectively, the development of intelligent paddy field equipment should focus on three key directions: the platformization and universalization of chassis design, minimizing disturbance to the crop's entire life cycle, and deepening the systemic integration of machinery and agronomy. Such advancements will promote the coordinated development of agricultural equipment and the paddy field ecosystem, ensuring the sustainability of regional food production.

Background and ObjectivesTumor Endothelial Marker 8 (TEM8) is integral to angiogenesis, tumor microenvironment remodeling, and cancer cell proliferation, and its expression is upregulated in a variety of malignancies. Despite its potential as both a prognostic biomarker and a therapeutic target in triple-negative breast cancer (TNBC), the exact role of TEM8 in TNBC remains poorly understood. This study seeks to examine the expression of TEM8 protein in TNBC and explore its associations with clinicopathological characteristics and patient survival outcomes.MethodsClinical and pathological data from 118 patients diagnosed with TNBC via surgical pathology between January 2015 and December 2017 were retrospectively analyzed at Harbin Medical University Cancer Hospital. A total of 35 adjacent non-cancerous tissue samples were randomly selected from the tumor tissue samples of the 118 TNBC patients. Immunohistochemistry (IHC) was employed to assess the expression levels of TEM8 and CD31 proteins. The correlations between TEM8 expression and various clinicopathological features, as well as survival status, were analyzed.ResultThe positive expression rate of TEM8 in TNBC tumor tissues was 89.8% (106/118), significantly higher than 60% (21/35) observed in adjacent non-tumorous tissues (χ² = 17.029, P < .01). TEM8 expression was significantly correlated with microvessel density (MVD), axillary lymph node status, and TNM staging. Moreover, patients with high TEM8 expression levels exhibited significantly lower overall survival (OS) rates compared to those with low TEM8 expression. Multivariate analysis revealed that TEM8 expression and tumor size were independent prognostic factors for OS.ConclusionsTEM8 is highly expressed in TNBC tissues and is closely associated with angiogenesis, tumor proliferation, lymph node metastasis, and poor prognosis. TEM8 may serve as a potential prognostic marker, offering new insights for the diagnosis and therapeutic strategies in TNBC.

Transjugular intrahepatic portosystemic shunt (TIPS) stands as a pivotal interventional therapy for managing portal hypertension (PH) and its associated complications. Distinguished from pharmacological treatments, endoscopic interventions, or surgical portocaval shunts, TIPS has achieved extensive clinical application attributed to its minimally invasive nature and efficacy. Notwithstanding, complications ensuing from TIPS, such as hepatic encephalopathy (HE) and shunt dysfunction, etc, significantly impact patient prognosis. Over the course of several decades, a diverse array of stent types and diameters have become available for TIPS procedures. Moreover, the stent puncture position and the initial stent position also exhibit variability. Our review aims to address this gap in knowledge by reviewing the research progress on stent types, diameters, puncture positions, and initial stent positions in the context of TIPS. It presents a comprehensive overview of the various stent options available for TIPS procedures and highlights the importance of individualized treatment approaches in reducing surgical complications and improving patient prognosis. The findings outlined in our review provide valuable insights for clinicians and researchers in the field.