As China accelerates its efforts in deep space exploration and long-duration space missions, including the operationalization of the Tiangong Space Station and the development of manned lunar missions, safeguarding astronauts’ physiological and cognitive functions under extreme space conditions becomes a pressing scientific imperative. Among the multifactorial stressors of spaceflight, microgravity emerges as a particularly potent disruptor of neurobehavioral homeostasis. Dopamine (DA) plays a central role in regulating behavior under space microgravity by influencing reward processing, motivation, executive function and sensorimotor integration. Changes in gravity disrupt dopaminergic signaling at multiple levels, leading to impairments in motor coordination, cognitive flexibility, and emotional stability. Microgravity exposure induces a cascade of neurobiological changes that challenge dopaminergic stability at multiple levels: from the transcriptional regulation of DA synthesis enzymes and the excitability of DA neurons, to receptor distribution dynamics and the efficiency of downstream signaling pathways. These changes involve downregulation of tyrosine hydroxylase in the substantia nigra, reduced phosphorylation of DA receptors, and alterations in vesicular monoamine transporter expression, all of which compromise synaptic DA availability. Experimental findings from space analog studies and simulated microgravity models suggest that gravitational unloading alters striatal and mesocorticolimbic DA circuitry, resulting in diminished motor coordination, impaired vestibular compensation, and decreased cognitive flexibility. These alterations not only compromise astronauts’ operational performance but also elevate the risk of mood disturbances and motivational deficits during prolonged missions. The review systematically synthesizes current findings across multiple domains: molecular neurobiology, behavioral neuroscience, and gravitational physiology. It highlights that maintaining DA homeostasis is pivotal in preserving neuroplasticity, particularly within brain regions critical to adaptation, such as the basal ganglia, prefrontal cortex, and cerebellum. The paper also discusses the dual-edged nature of DA plasticity: while adaptive remodeling of synapses and receptor sensitivity can serve as compensatory mechanisms under stress, chronic dopaminergic imbalance may lead to maladaptive outcomes, such as cognitive rigidity and motor dysregulation. Furthermore, we propose a conceptual framework that integrates homeostatic neuroregulation with the demands of space environmental adaptation. By drawing from interdisciplinary research, the review underscores the potential of multiple intervention strategies including pharmacological treatment, nutritional support, neural stimulation techniques, and most importantly, structured physical exercise. Recent rodent studies demonstrate that treadmill exercise upregulates DA transporter expression in the dorsal striatum, enhances tyrosine hydroxylase activity, and increases DA release during cognitive tasks, indicating both protective and restorative effects on dopaminergic networks. Thus, exercise is highlighted as a key approach because of its sustained effects on DA production, receptor function, and brain plasticity, making it a strong candidate for developing effective measures to support astronauts in maintaining cognitive and emotional stability during space missions. In conclusion, the paper not only underscores the centrality of DA homeostasis in space neuroscience but also reflects the authors’ broader academic viewpoint: understanding the neurochemical substrates of behavior under microgravity is fundamental to both space health and terrestrial neuroscience. By bridging basic neurobiology with applied space medicine, this work contributes to the emerging field of gravitational neurobiology and provides a foundation for future research into individualized performance optimization in extreme environments.

ObjectivePrimary liver cancer, predominantly hepatocellular carcinoma (HCC), is a significant global health issue, ranking as the sixth most diagnosed cancer and the third leading cause of cancer-related mortality. Accurate and early diagnosis of HCC is crucial for effective treatment, as HCC and non-HCC malignancies like intrahepatic cholangiocarcinoma (ICC) exhibit different prognoses and treatment responses. Traditional diagnostic methods, including liver biopsy and contrast-enhanced ultrasound (CEUS), face limitations in applicability and objectivity. The primary objective of this study was to develop an advanced, light-weighted classification network capable of distinguishing HCC from other non-HCC malignancies by leveraging the automatic analysis of brightness changes in CEUS images. The ultimate goal was to create a user-friendly and cost-efficient computer-aided diagnostic tool that could assist radiologists in making more accurate and efficient clinical decisions. MethodsThis retrospective study encompassed a total of 161 patients, comprising 131 diagnosed with HCC and 30 with non-HCC malignancies. To achieve accurate tumor detection, the YOLOX network was employed to identify the region of interest (ROI) on both B-mode ultrasound and CEUS images. A custom-developed algorithm was then utilized to extract brightness change curves from the tumor and adjacent liver parenchyma regions within the CEUS images. These curves provided critical data for the subsequent analysis and classification process. To analyze the extracted brightness change curves and classify the malignancies, we developed and compared several models. These included one-dimensional convolutional neural networks (1D-ResNet, 1D-ConvNeXt, and 1D-CNN), as well as traditional machine-learning methods such as support vector machine (SVM), ensemble learning (EL), k-nearest neighbor (KNN), and decision tree (DT). The diagnostic performance of each method in distinguishing HCC from non-HCC malignancies was rigorously evaluated using four key metrics: area under the receiver operating characteristic (AUC), accuracy (ACC), sensitivity (SE), and specificity (SP). ResultsThe evaluation of the machine-learning methods revealed AUC values of 0.70 for SVM, 0.56 for ensemble learning, 0.63 for KNN, and 0.72 for the decision tree. These results indicated moderate to fair performance in classifying the malignancies based on the brightness change curves. In contrast, the deep learning models demonstrated significantly higher AUCs, with 1D-ResNet achieving an AUC of 0.72, 1D-ConvNeXt reaching 0.82, and 1D-CNN obtaining the highest AUC of 0.84. Moreover, under the five-fold cross-validation scheme, the 1D-CNN model outperformed other models in both accuracy and specificity. Specifically, it achieved accuracy improvements of 3.8% to 10.0% and specificity enhancements of 6.6% to 43.3% over competing approaches. The superior performance of the 1D-CNN model highlighted its potential as a powerful tool for accurate classification. ConclusionThe 1D-CNN model proved to be the most effective in differentiating HCC from non-HCC malignancies, surpassing both traditional machine-learning methods and other deep learning models. This study successfully developed a user-friendly and cost-efficient computer-aided diagnostic solution that would significantly enhances radiologists’ diagnostic capabilities. By improving the accuracy and efficiency of clinical decision-making, this tool has the potential to positively impact patient care and outcomes. Future work may focus on further refining the model and exploring its integration with multimodal ultrasound data to maximize its accuracy and applicability.

Tumor cells use glycolysis to provide material and energy under hypoxic conditions to meet the energy requirements for rapid growth and proliferation， namely the Warburg effect. Even under aerobic conditions， tumor cells mainly rely on glycolysis to provide energy. Therefore， glucose transporter protein 1（GLUT1）， which is involved in the process of glucose metabolism， plays an important role in tumorigenesis， development and drug resistance， and is considered to be one of the important targets in the treatment of malignant tumors. In recent years， research on tumor glucose metabolism has gradually become a hot spot. It has been shown that various factors are involved in the regulation of tumor energy metabolism， among which the role of GLUT1 is the most critical. In this paper， the authors reviewed the latest research progress of GLUT1-targeted traditional Chinese medicine（TCM） active ingredient nano-delivery system in tumor therapy， aiming to reveal the feasibility and effectiveness of this system in the delivery of chemotherapeutic drugs. The GLUT1-targeted TCM active ingredient nano-delivery system can overcome the bottleneck of the traditional targeting strategy as well as the high-permeability long retention（EPR） effect. In summary， the authors believe that the GLUT1-targeted TCM active ingredient nano-delivery system provides a new strategy for targeted treatment of tumors and has a broad application prospect in tumor prevention and treatment.

Objective To summarize the epidemiological and clinical features of infectious diseases of the central nervous system(CNS)by a single-center analysis.Methods A retrospective analysis was conducted on the data of 1247 cases of CNS infectious diseases diagnosed and treated in the First Medical Center of PLA General Hospital from 2001 to 2020.Results The data for this group of CNS infectious diseases by disease type in descending order of number of cases were viruses 743(59.6％),Mycobacterium tuberculosis 249(20.0％),other bacteria 150(12.0％),fungi 68(5.5％),parasites 18(1.4％),Treponema pallidum 18(1.4％)and rickettsia 1(0.1％).The number of cases increased by 177 cases(33.1％)in the latter 10 years compared to the previous 10 years(P<0.05).No significant difference in seasonal distribution pattern of data between disease types(P>0.05).Male to female ratio is 1.87︰1,mostly under 60 years of age.Viruses are more likely to infect students,most often at university/college level and above,farmers are overrepresented among bacteria and Mycobacterium tuberculosis,and more infections of Treponema pallidum in workers.CNS infectious diseases are characterized by fever,headache and signs of meningeal irritation,with the adductor nerve being the more commonly involved cranial nerve.Matagenomic next-generation sequencing improves clinical diagnostic capabilities.The median hospital days for CNS infectious diseases are 18.00(11.00,27.00)and median hospital costs are ￥29,500(￥16,000,￥59,200).The mortality rate from CNS infectious diseases is 1.6％.Conclusions The incidence of CNS infectious diseases is increasing last ten years,with complex clinical presentation,severe symptoms and poor prognosis.Early and accurate diagnosis and standardized clinical treatment can significantly reduce the morbidity and mortality rate and ease the burden of disease.

Objective: To learn the characteristics of varicella breakthrough cases aged under 14 years in Haizhu District, Guangzhou City and the effects of vaccination on incidence of breakthrough cases, so as to provide the basis for improving varicella vaccination strategy. Methods: Data of varicella cases aged under 14 years and vaccination in Haizhu District were collected through Chinese Disease Prevention and Control Information System and Guangdong Provincial Vaccination and Vaccine Circulation Management Information System from 2015 to 2022. Temporal distribution, population distribution and vaccination history of varicella breakthrough cases were descriptively analyzed. Effects of primary immunization age and inoculation interval on breakthrough interval were analyzed using least square method fitting bi-cubic functional equation. Results: A total of 4 008 varicella breakthrough cases aged under 14 years were reported in Haizhu District from 2015 to 2022, accounting for 29.16% of all varicella cases. There were mainly 1-dose breakthrough cases, with 3 607 cases accounting for 90.00%. The proportion of 1-dose breakthrough cases showed a downward trend, while the proportion of 2-dose breakthrough cases showed an upward trend (both P<0.05). The epidemics peaked from March to May and from November to January, with a male-to-female ratio of 1.41︰1. The age of onset was mainly at 4 to 6 years, with 1 189 cases accounting for 29.67%. The primary immunization age was mainly ranged from 12 to <24 months, with 2 662 cases accounting for 66.42%. Vaccination of the second dose was concentrated at the age of 48 to <60 months, with 136 cases accounting for 33.92%. The breakthrough interval was relatively long among cases with primary immunization age at 12 to <36 months and inoculation interval within 45 months, with a median breakthrough interval of 25.24 (interquartile range, 20.00) months. Primary immunization age and inoculation interval were negatively correlated with breakthrough interval (P<0.05). Conclusions The varicella breakthrough cases aged under 14 years in Haizhu District from 2015 to 2022 were mainly occurred at the beginning of the new term, with a high incidence among preschool children. It is recommended that children receive the first dose of varicella vaccine within 36 months of age and booster within 45 months of interval.

Vitamin D is a unique fat-soluble vitamin that plays an indispensable role in human health. It exists in various forms, the most significant being vitamin D₂ (derived from plant sources) and vitamin D₃ (synthesized naturally in human skin upon exposure to sunlight). Vitamin D’s primary function is to facilitate the absorption of calcium and phosphorus, which are crucial for maintaining healthy bones. Beyond its role in bone health, vitamin D significantly influences the immune system, muscle function, cardiovascular health, and the regulation of brain functions. A deficiency in vitamin D can lead to various chronic diseases such as rickets, osteoporosis, decreased immunity, increased risk of mental disorders, and cancers. The synthesis of vitamin D in the human body, both peripherally and centrally, relies on sunlight exposure, dietary sources, and various supplements. As a neuroactive steroid, vitamin D impacts both the physiological and pathological processes of the nervous system and plays a key role in brain health. It profoundly affects the brain by regulating neurotransmitter synthesis and maintaining intracellular calcium balance. As an essential chemical molecule, vitamin D participates in complex signal transduction pathways, impacting neurotransmitter functions and synaptic plasticity. Vitamin D’s role in regulating dopamine (DA)—a neurotransmitter critical for motivation, reward perception, and other higher cognitive functions—is particularly noteworthy. Recent studies have revealed that vitamin D not only promotes the synthesis of DA but also plays a role in regulating DA levels within the brain. It exerts neuroprotective effects on DA neurons through anti-inflammatory, antioxidant actions, and neurotrophic support, thereby creating an optimal environment for DA neurons, influencing neuronal structure, and affecting the movement of calcium ions within nerve cells, positively impacting the overall health and functionality of the DA system. Furthermore, vitamin D can regulate the synthesis and release of DA, thus affecting the signal transmission of various DA neural projection pathways in the brain. This function is vital for understanding the complex interactions between neural mechanisms and their effects on key behaviors and cognitive functions. This review aims to delve deeply into the synthesis, metabolism, and pathways of vitamin D’s action, especially its regulatory mechanisms on DA neurons. Through this exploration, this article seeks to provide a solid theoretical foundation and research framework for a deeper understanding of vitamin D’s role in motivation and reward behaviors. This understanding is crucial for appreciating the broader significance of vitamin D in the fields of neuroscience and neurology. In summary, research and discoveries regarding vitamin D’s impact on the nervous system highlight its importance in neural health and function. These insights not only enhance our understanding of the complex workings of the nervous system but also open new avenues for the prevention and treatment of neurological diseases. The exploration of vitamin D’s multifaceted roles offers promising prospects for developing new therapeutic strategies, underscoring the compound’s potential in addressing a range of neural dysfunctions and diseases. As research continues to evolve, the profound implications of vitamin D in the field of neurology and beyond become increasingly apparent, marking it as a key target for ongoing and future scientific inquiry.

Ankylosing spondylitis (AS) combined with lower cervical fracture is often categorized into unstable fracture, with a high incidence of neurological injury and a high rate of disability and morbidity. As factors such as shoulder occlusion may affect the accuracy of X-ray imaging diagnosis, it is often easily misdiagnosed at the primary diagnosis. Non-operative treatment has complications such as bone nonunion and the possibility of secondary neurological damage, while the timing, access and choice of surgical treatment are still controversial. Currently, there are no clinical practice guidelines for the treatment of AS combined with lower cervical fracture with or without dislocation. To this end, the Spinal Trauma Group of Orthopedics Branch of Chinese Medical Doctor Association organized experts to formulate Clinical guidelines for the treatment of ankylosing spondylitis combined with lower cervical fracture in adults ( version 2024) in accordance with the principles of evidence-based medicine, scientificity and practicality, in which 11 recommendations were put forward in terms of the diagnosis, imaging evaluation, typing and treatment, etc, to provide guidance for the diagnosis and treatment of AS combined with lower cervical fracture.

Objective:To explore the clinical and electrophysiological characteristics of peripheral neuropathy in prediabetic patients.Methods:Subjects aged 20-65 years with high-risk factors of impaired glycemia enrolled in Beijing Tiantan Hospital, Capital Medical University from 2019 to 2022 were recruited to conduct oral glucose tolerance test, after excluding other causes of neuropathy or radiculopathy. Patients with impaired fasting glucose or impaired glucose tolerance were defined by American Diabetes Association criteria. These patients were divided into clinical polyneuropathy (PN) and clinical non-PN groups, according to the 2010 Toronto consensus criteria and the presence of PN symptoms and signs or not. Nerve conduction studies (NCS), F wave, sympathetic skin response (SSR), R-R interval variation (RRIV) and current perception thresholds (CPT) were performed and the abnormal rate was compared between different electrodiagnostic methods and between clinical subgroups.Results:Among the 73 prediabetic patients ultimately enrolled, only 20 (27.4%) can be diagnosed as clinical PN according to the Toronto consensus criteria. The abnormal rate of CPT (68.5%, 50/73) was significantly higher than those of F wave (2.7%, 2/73), lower limb NCS (0, 0/73), upper limb NCS changes of carpal tunnel syndrome (26.0%, 19/73), SSR (6.8%, 5/73) and RRIV (5.5%, 4/73; McNemar test, all P<0.001). With sinusoid-waveform current stimuli at frequencies of 2 000 Hz, 250 Hz and 5 Hz, the CPT device was used to measure cutaneous sensory thresholds of large myelinated, small myelinated and small unmyelinated sensory fibers respectively. CPT revealed a 21.9% (16/73) abnormal rate of unmyelinated C fiber in the hands of prediabetic patients, significantly higher than that of large myelinated Aβ fibers [8.2% (6/73), χ2=5.352, P=0.021]. Both abnormal rates of small myelinated Aδ [42.5% (31/73)] and unmyelinated C fibers [39.7% (29/73)] in the feet of prediabetic patients were significantly higher than that of large myelinated Aβ fibers [11.0% (8/73), χ2=18.508, 15.965, both P<0.001]. Compared with the clinical non-PN group, the abnormal rates of CPT [90.0% (18/20) vs 60.4% (32/53), χ2=5.904, P=0.015] and SSR [20.0% (4/20) vs 1.9% (1/53), P=0.016) were significantly higher in the clinical PN group. Conclusions:Peripheral neuropathies in prediabetic patients are usually asymptomatic or subclinical, and predispose to affect unmyelinated and small myelinated sensory fibers. Selective electrodiagnostic measurements of small fibers help to detect prediabetic neuropathies in the earliest stages of the disease.

Objective To explore the impact of SARS-CoV-2-positive donors on the prognosis of heart transplant recipients. Methods The Medline, EMbase, CENTRAL, CNKI, Wanfang Data, VIP and China Biology Medicine from inception to May 2023 were searched by computer for studies about impact of SARS-CoV-2-positive donors on the prognosis of heart transplant recipients. The data were extracted from all the relevant literatures, and the quality of the data was assessed using the Newcastle-Ottawa Scale (NOS). All statistical analyses were conducted by the Stata 11.0 software. Results A total of 10 studies (NOS score ranging from 5 to 9 points) involving 643 patients were enrolled. The pooled results demonstrated that the pooled mortality of heart transplant recipients from SARS-CoV-2-positive donors was 4% (95%CI 2% to 5%). And the incidence of composite outcome, regarding graft failure, rejection and death as poor prognosis, was 7% (95%CI 5% to 9%). Besides, compared with recipients from SARS-CoV-2-negative donors, the pooled odds ratio (OR) value of death of SARS-CoV-2-positive donors was 0.68 (95%CI 0.38 to 1.22, Z=1.28, P=0.200). The pooled OR value of rejection rate was 0.41 (95%CI 0.27 to 0.64, Z=3.97, P<0.005). For the composite outcome, the pooled OR value was 0.50 (95%CI 0.37 to 0.69, Z=4.30, P<0.005). In addition, there was no statistical difference in the length of hospital stay between heart transplant recipients from SARS-CoV-2-positive donors and negative donors (SMD=–0.03, 95%CI –0.22 to 0.15, Z=0.36, P=0.720). Conclusion The application of heart from SARS-CoV-2-positive donor for transplantation is safe and feasible. However, further prospective studies with longer follow-up are still needed to verify its impact on long-term outcomes.

Objective:To evaluate the association between preoperative serum β 2-microglobulin (β 2MG) concentrations and postoperative delirium (POD) in elderly patients. Methods:The study selected patients who underwent knee or hip arthroplasty under spinal-epidural anesthesia on an elective basis at Qingdao Municipal Hospital from May 2021 to November 2022. The patients were divided into a POD group and a non-POD group based on the occurrence of POD. The study was conducted as part of the Perioperative Neurocognitive Impairment and Biomarkers Lifestyle Cohort, which was a nested case-control study. The study collected baseline data from two groups of patients and analyzed the differences between them. Logistic regression was used to identify the risk factors for POD. The stability of the regression model was tested using sensitivity analysis. The mediation model was used to examine whether cerebrospinal fluid (CSF) biomarkers mediated the relationship between β 2MG and POD. The receiver operating characteristic curve was drawn and the area under the curve was calculated to evaluate the accuracy of preoperative β 2MG concentrations and CSF biomarker concentration in predicting POD. Results:There were 57 cases in POD group and 449 cases in non-POD group. The results of logistic regression analysis showed that the increased β 2MG and CSF total tau protein (t-tau) concentrations were risk factors for POD, and the increased CSF β-amyloid 42 concentration was a protective factor for POD after adjustment for multiple confounders such as age, gender, education, Mini-Mental State Examination, history of hypertension and infusion volume ( P<0.05). The results of mediation analysis showed that the serum β 2MG′s effect on POD was partly mediated by t-tau (18.1%). The results of the receiver operating characteristic curve showed that the area under the curve of the β 2MG concentration combined with the CSF biomarker concentration was 0.742. Conclusions:Elevated preoperative serum β 2MG concentration is a risk factor for POD in elderly patients, and the relationship may be partly mediated by CSF t-tau.