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关键词： alloying elements   exchange coupling interaction   intrinsic magnetic parameters   microstructure   nanocomposite permanent magnets  

摘要： Nanocomposite magnets have become a promising next-generation permanent magnet material due to their potential high magnetic energy product. The implementation of high magnetic performance depends on precise control of the microstructure, including the grain size and distribution of soft and hard magnetic phases, the content of soft magnetic phases, the orientation of hard magnetic phases, the structure and chemical composition, etc. At present, the microstructure of nanocomposite magnets is mainly controlled by adjusting the alloy composition and preparation process. By adding alloying elements, not only can improve the microstructure of nanocomposite permanent magnets, but also can change the intrinsic magnetic parameters of the main phase in the magnet, which is a common method to improve the magnetic performance of the magnet. In this work, the role of alloying elements in microstructure control of RE₂Fe₁₄B (RE=Nd, Pr) based nanocomposite permanent magnet materials is summarized and evaluated. The addition of rare earth elements (La, Ce, Pr, Dy, Tb, etc.) to replace Nd atoms alters the intrinsic magnetic parameters of Nd₂Fe₁₄B phase. Elements such as Co, Cr, Ni, and Mn can enter the lattice of α-Fe and RE₂Fe₁₄B to replace by the point position of Fe, while changing the intrinsic magnetic parameters of the soft and hard magnetic phases, thereby altering the magnetic properties of the magnet. It has been confirmed that elements such as Nb, Ti, and Zr can enter the main phase Nd₂Fe₁₄B, but are more enriched at grain boundaries, playing a role in enhancing domain wall pinning and refining grain size. Elements such as Sn and Ga can improve the high-temperature magnetic performance of magnets and enhance their thermal stability. Adjusting the alloy composition through the addition of alloying elements is an effective way to control the microstructure of nanocomposite magnets, but t

关键词： Helicobacter pylori   Influence factor   Navy   Positivity rate  

摘要： Objective To analyze the Ｈelicobacter pylori（Hp）positivity rate and its related influencing factors among naval personnel. Methods From September 2022 to December 2023，4 377 naval personnel were selected as the study population by the convenience sampling method. The ¹³C-urea breath test was employed for detecting Hp infection. Basic demographic information and the occurrence of gastrointestinal symptoms in the past three months were collected through questionnaire surveys for analyzing the factors influencing the Hp positivity rate among naval personnel. Results The overall Hp positivity rate among the 4 377 naval personnel was 31.7%. The positivity rate was significantly related with gender，smoking，cumulative mission duration in the past three months，yogurt consumption，antibiotic use in the past two weeks，abdominal pain in the past three months，and nausea in the past three months（all P<0.05）. Multivariate logistic regression analysis revealed that age（38-47 years）（OR=0.628， P=0.011）and antibiotics use in the past two weeks（OR=0.655，P=0.027）were independent protective factors against Hp positivity，while being male（OR=1.857，P=0.009），cumulative mission duration in the past three months（31-60 days）（OR=1.321，P=0.020），and smoking（OR=1.210，P=0.005）were independent risk factors for Hp positivity. Conclusion Regarding the factors influencing Hp positivity，it is necessary to enhance health education and hygiene promotion concerning Hp infection among naval personnel，improve sanitation facilities at the small-unit level，correct unhealthy lifestyle habits，and maintain a high vigilance for symptoms such as abdominal pain and nausea. A systematic plan for the prevention，detection，and eradication of Hp among naval personnel should be developed to ensure their combat readiness. © 2025 Chinese Medical Journals Publishing House ***. All rights reserved.

关键词： Advanced gastric cancer   Hyperbaric oxygen   Neoadjuvant chemotherapy   Neutrophil-to-lymphocyte ratio   Platelet-to-lymphocyte ratio   Recurrence rate  

摘要： Objective To investigate the clinical efficacy of hyperbaric oxygen combined with neoadjuvant chemotherapy in patients undergoing radical surgery for advanced gastric cancer，and its impact on neutrophil-to-lymphocyte ratio（NLR），platelet-to-lymphocyte ratio（PLR），and postoperative recurrence. Methods Eighty-six patients who underwent radical gastrectomy at the Peace Hospital Affiliated to Changzhi Medical College from May 2018 to June 2023 were randomly divided into a control group and a study group，with 43 cases in each，according to the random number table method. The control group received postoperative neoadjuvant chemotherapy，while the study group additionally received hyperbaric oxygen therapy on the basis of the treatment of the control group. The clinical efficacy，incidence of adverse reactions，tumor recurrence rate within six months post-treatment，and levels of carcinoembryonic antigen（CEA），carbohydrate antigen 72-4（CA72-4），gastrointestinal hormones（motilin and gastrin），and inflammation-related indicators［tumor necrosis factor-alpha（TNF-α），interleukin-6（IL-6），NLR，and PLR］before and after treatment were compared between the two groups. Results After treatment，the total effective rate in the study group（65.12%）was higher than that in the control group（53.49%），with a statistically significant difference（P<0.05）. The levels of CEA，CA72-4，TNF-α，IL-6，NLR，and PLR in the study group were lower than those in the control group，while the levels of motilin and gastrin were higher，all with statistically significant differences（all P<0.05）. There was no significant difference in the overall incidence of adverse reactions between the two groups during treatment（P>0.05）. The tumor recurrence rate within six months post-treatment in the study group（0）was lower than that in the control group（9.30%），with a statistically significant difference（P<0.05）. Conclusion Hyperbaric oxygen combined with neoadjuvant chemotherapy in patients undergoing radical surgery for advanced gastric c

关键词： CO2 embolism   Endoscopic retrograde cholangiopancreatography   Hyperbaric oxygen  

关键词： Atorvastatin   Coagulation function   Coronary heart disease   Hyperbaric oxygen   Inflammatory response   Percutaneous coronary intervention   Vascular endothelial function  

摘要： Objective To explore the effects of hyperbaric oxygen combined with atorvastatin on the indexes of serum inflammatory factors，vascular endothelial function，and coagulation function in patients with coronary heart disease after percutaneous coronary intervention（PCI）. Methods A total of 186 patients with coronary heart disease who underwent PCI in the Department of Cardiovascular Medicine of Chang An Hospital from January 2021 to December 2023 were selected as the research subjects，and were divided into control group（n=93）and observation group（n=93），according to the random number table method. The control group was treated with atorvastatin on the basis of conventional symptomatic treatment，and the observation group was additionally treated with hyperbaric oxygen on the basis of the treatment of the control group. Before and after treatment，the levels of hypersensitive C-reactive protein（hs-CRP），lipoprotein-associated phospholipase A2（LP-PLA₂），and tumor necrosis factor（TNF-α）were detected by radioimmunoassay. The levels of serum nitric oxide（NO），endothelin-1（ET-1），and homocysteine（HCY）were also detected by radioimmunoassay. Plasma prothrombin time（PT），activated partial thromboplastin time（APTT），thrombin time（TT），and D-dimer（D-D）levels were measured by automatic blood coagulation analyzer. The incidence of major adverse cardiovascular events（MACE）such as cardiac deterioration，stent thrombosis，and recurrent angina pectoris were recorded. Results After treatment，the levels of hs-CRP，LP-PLA2，TNF-α，ET-1，and HCY in the two groups were significantly decreased（all P<0.01），and the above indexes in the observation group were significantly lower than those in the control group after treatment（all P<0.05）. After treatment，the level of NO was significantly increased（P<0.01），and the level of NO in the observation group was significantly higher than that in the control group（P<0.05）. After treatment，the plasma D-D levels in the two groups were significantly decreased，and