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.

Objective Based on the “excellent” performance achieved by our institution in the 2024 national intercomparison of monitoring individual dose from external exposure, this paper systematically summarizes key technical elements and optimization experiences in instrument calibration, operational protocols, and data analysis, aiming to provide methodological references and practical support for continuously enhancing the accuracy and reliability of individual dose monitoring. Methods As a participant in the intercomparison activity, our laboratory strictly followed the technical protocol formulated by the Chinese Center for Disease Control and Prevention. Results In the 2024 national intercomparison of monitoring individual dose from external exposure, the measurement results met the criteria of single-group performance \begin{document}$ \left|{P}_{i}\right| $\end{document} ≤ 0.10 and comprehensive performance B² + S² ≤ 0.10², and were rated as excellent. Conclusion The accuracy and reliability of monitoring individual dose from external exposure depend on the precision of instrument calibration, standardization of operations, and strictness of quality control. The effectiveness of the above quality control methods has been confirmed by the practice of our laboratory. These methods can be used to ensure the accuracy of measurement results.

Objective:To analyze the status quo and advanced trend of voice training research in the world, and provide new ideas for voice training research in China.Methods:The literature on voice training in Web of Science core collection database was searched from January 1, 2013 to July 31, 2023, and visual analysis was performed using CiteSpace 6.1.R6 software.Results:A total of 964 papers were retrieved, and the number of published papers showed an increasing trend. The country with the largest number of publications was the United States, with 387. The Journal with the most publications was Journal of Voice. The research focused on voice rehabilitation of patients with different voice disorders, voice training intervention methods, improvement of quality of life and improvement of training compliance. The application of voice training in geriatric diseases might be a future research trend. Conclusions:At present, the field of voice training is deepening in the direction of new research and application, and the public's demand for voice rehabilitation is increasing. It is suggested that multidisciplinary collaboration should be strengthened in the future to explore the clinical efficacy of voice training in more different populations and diseases.

Sick sinus syndrome(SSS)refers to damage to the sinoatrial node and its surrounding tissues,which leads to excitation and conduction dysfunction of the sinoatrial node,Resultsing in arrhythmia diseases.A better understanding of the pathogenesis of SSS is required to provide a basis for its treatment,including establishing an animal model that can simulate human sinus node dysfunction.In this paper,we review the animal selection,the principles and method of modeling,and the evaluation method and detection indicators of the models,to provide a basis for further studies of the pathogenesis of SSS.

AIM To explore the effects and mechanism of verbascoside on adenine-induced infertility in rats.METHODS Rats randomly divided into the blank group,the model group,the positive control group(100 mg/kg Compound Xuanju Capsule)and low and high dose groups of verbascoside(50 and 100 mg/kg)were given 150 mg/kg adenine daily for 14 days to establish the rat model of infertility,except those of the blank group,followed by the 28 days corresponding gavage of the drugs.The rats had their general activities observed;their indexes levels of liver,kidney,testis and epididymis calculated;their sperms checked under the microscope;their pathological morphology of the liver,the kidney and the testis observed by HE staining;their spermatogenesis evaluated using the Johnsen scoring method;their serum levels of T,LH,FSH and GnRH detected by ELISA;and their testicular mRNA and protein expressions of mTOR,LC3B and ULK1 detected by RT-qPCR and Western blot.RESULTS Compared with the blank group,the model group displayed increased index level of the kidney(P＜0.05),decreased sperm count,sperm activity rate and sperm index level(P＜0.05),decreased serum levels of T and GnRH(P＜0.05),increased levels of LH and FSH(P＜0.05),obviously pathological damage of the kidney and testis,increased testicular expressions of mTOR mRNA and protein(P＜0.05),decreased expressions of LC3B and ULK1 mRNA and protein(P＜0.05),and decreased expression of p-mTOR protein(P＜0.05).Compared with the model group,the high-dose verbascoside group demonstrated decreased renal index level(P＜0.05),increased sperm count and sperm activity rate(P＜0.05),increased serum T level(P＜0.05),decreased LH and FSH levels(P＜0.05),improved pathological damage of the kidney and the testis at different levels,decreased testicular expressions of mTOR mRNA and protein(P＜0.05),increased expressions of LC3B,ULK1 mRNA and protein(P＜0.05),and increased expression of p-mTOR protein(P＜0.05).The high-dose verbascoside group displayed the same effects as those of the positive control Compound Xuanju Capsule.CONCLUSION Verbascoside can effectively improve the sperm quality,sex hormone disorder,reproductive function and pathological damage of kidney and testis in infertile rats,and its mechanism may be related to the enhanced positive regulation of autophagy and regulated hypothalamus-pituitary-testis axis disorder.

Lipopolysaccharides (LPS) are major outer membrane components of Gram-negative bacteria. Unlike most Gram-negative bacteria, Acinetobacter baumannii can still survive and acquire polymyxin resistance after complete loss of LPS. Previous studies of LPS-deficient Acinetobacter baumannii mostly focused on LPS-deficient strains induced by polymyxin, whose background was complex and unstable. To investigate LPS loss-mediated polymyxin resistant-Acinetobacter baumannii, this study constructed a stable and clear background LPS-deficient strain by knocking out lpxC gene in Acinetobacter baumannii ATCC 19606 with CIRSPR/Cas9, and then studied the phenotypic changes of the lpxC-deficient strain including morphology, growth rate, antibiotic susceptibility, virulence, membrane permeability, and membrane potential. Animal experiments were approved by the Animal Care and Welfare Committee Institute of Medicinal Biotechnology, CAMS and PUMC (approval number: IMB-20240119D₉). The results indicated that the lpxC gene of Acinetobacter baumannii ATCC 19606 was successfully knocked out. After losing the lpxC, the strain underwent the morphological change from rod-shaped to spherical. Furthermore, it leads to reduced growth rate, enhanced membrane permeability, decreased membrane potential, lower virulence, and increased antibiotic susceptibility to β-lactams, quinolones, aminoglycosides, macrolides, glycopeptides. The lpxC deletion results in significant changes in membrane homeostasis and adaptability of Acinetobacter baumannii. Understanding the phenotypic changes of colistin-resistant Acinetobacter baumannii mediated by LPS loss is useful for exploring the resistance mechanism of Acinetobacter baumannii and developing new therapeutic strategies.

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.

Humans ; Aortic Dissection ; Aorta

The end of the COVID-19 infection peak in 2022 prompts a backlog of cardiovascular surgical patients to gradually return to the hospital, resulting in a surge in cardiovascular surgeries. However, against the backdrop of the COVID-19 pandemic, the clinical practice of cardiovascular surgery faces many problems. Therefore, organized by Beijing Anzhen Hospital, experts in cardiovascular surgery and related fields have formulated hospital expert experience on perioperative treatment principles of cardiovascular surgery for patients infected with COVID-19. This article summarizes the clinical decision-making of patients requiring cardiovascular surgery after COVID-19 infection, and advises on the corresponding recommendations according to the existing evidence-based medical evidence as well as the actual clinical practice experience of relevant experts. The main content of the article includes special requirements for cardiovascular surgical treatment indications in patients with COVID-19 infection, selection of surgical timing, special requirements of preoperative, intraoperative and postoperative management, etc., which aims to provide COVID-19-infected patients with guidance on rational decision-making when receiving cardiovascular surgery.