1.Comprehensive Application of AHP-CRITIC Hybrid Weighting Method, Grey Correlation Analysis and BP-ANN in Optimization of Extraction Process of Qizhi Prescription
Qun LAN ; Yi CHENG ; Zian LI ; Bingyu WU ; Jinyu WANG ; Dewen LIU ; Yan TONG
Chinese Journal of Experimental Traditional Medical Formulae 2025;31(8):176-186
ObjectiveBased on analytic hierarchy process(AHP)-criteria importance through intercriteria correlation(CRITIC) hybrid weighting method, grey relational analysis and backpropagation artificial neural network(BP-ANN), to optimize the water extraction process of Qizhi prescription, so as to provide an experimental basis for optimization of the preparation process of this prescription and the establishment of quality standards. MethodsL9(34) orthogonal test was employed, and the AHP-CRITIC hybrid weighting method was utilized to determine the weight coefficients of the quality fractions of various components, including astragaloside Ⅳ, polygalaxanthone Ⅲ, calycosin-7-O-β-D-glucoside, tenuifolin, and 3,6′-disinapoylsucrose, as well as the dry extract yield. The comprehensive score of each factor level combination in the orthogonal test were calculated as evaluation indicator to select the optimal extraction process parameters. The effects of extraction times, extraction time, and solvent dosage on the aqueous extraction process of the formula were investigated through intuitive analysis, variance analysis, and grey relational analysis. Meanwhile, a BP-ANN model was established to reverse-predict the optimal extraction process parameters of Qizhi prescription, and the optimized process parameters were validated. ResultsThe weight coefficients of the five index components(astragaloside Ⅳ, tenuifolin, calycosin-7-O-β-D-glucoside, polygalaxanthone Ⅲ, and 3,6′-disinapoylsucrose) and dry extract yield were 25.7%, 20.82%, 16.41%, 12.45%, 15.96% and 8.67%, respectively. The optimized extraction process parameters were extracted 3 times with 8, 6, 6 times the amount of water, each time for 1 h. The network prediction results of BP-ANN test samples were consistent with the orthogonal test results, and the mean square error(MSE) of the predicted and measured values of the network was <1%. The water extraction process of Qizhi prescription analyzed and predicted by relevant mathematical models was stable and feasible, which could effectively improve the extraction efficiency of the active ingredients of Astragali Radix and Polygalae Radix, and the average comprehensive score of the validation test was 90.85 with the relative standard deviation(RSD) of 1.55%. ConclusionThis study establishes a water extraction process for compound Qizhi granules, and the optimized extraction process can effectively improve the extraction efficiency of active ingredients, which provides useful references for the optimization of preparation process and the establishment of quality standards for other clinical experience formulas.
2.Oxylipidomics Combined with Transcriptomics Reveals Mechanism of Jianpi Huogu Prescription in Treating Steroid-induced Osteonecrosis of Femoral Head in Rats
Lili WANG ; Qun LI ; Zhixing HU ; Qianqian YAN ; Liting XU ; Xiaoxiao WANG ; Chunyan ZHU ; Yanqiong ZHANG ; Weiheng CHEN ; Haijun HE ; Chunfang LIU ; Na LIN
Chinese Journal of Experimental Traditional Medical Formulae 2025;31(11):190-199
ObjectiveTo unveil the mechanism of Jianpi Huogu prescription (JPHGP) in ameliorating the dyslipidemia of steroid-induced osteonecrosis of the femur head (SONFH) by oxylipidomics combined with transcriptomics. MethodsSixty SD rats were assigned into normal, model, low-, medium-, and high-dose (2.5, 5, 10 g·kg-1, respectively) JPHGP, and Jiangushengwan (1.53 g·kg-1) groups. Lipopolysaccharide was injected into the tail vein at a dose of 20 μg·kg-1 on days 1 and 2, and methylprednisolone sodium succinate was injected at a dose of 40 mg·kg-1 into the buttock muscle on days 3 to 5. The normal group received an equal volume of normal saline. Drug administration by gavage began 4 weeks after the last injection, and samples were taken after administration for 8 weeks. Hematoxylin-eosin staining was conducted to reveal the histopathological changes of the femoral head, and the number of adipocytes, the rate of empty bone lacunae, and the trabecular area were calculated. Micro-computed tomography was used for revealing the histological and histomorphometrical changes of the femoral head. Enzyme-linked immunosorbent assay was employed to measure the serum levels of triglyceride (TG), total cholesterol (TC), low-density lipoprotein (LDL), high-density lipoprotein (HDL), apolipoprotein A1 (ApoA1), and apolipoprotein B (ApoB). At the same time, the femoral head was collected for oxylipidomic and transcriptomic detection. The differential metabolites and differential genes were enriched and analyzed, and the target genes regulating lipid metabolism were predicted. The predicted target proteins were further verified by molecular docking, immunohistochemistry, and Western blot. ResultsCompared with the normal group, the model group showcased thinning of the femoral head, trabecular fracture, karyopyknosis, subchondral cystic degeneration, increases in the number of adipocytes and the rate of empty bone lacunae (P<0.01), a reduction in the trabecular area (P<0.01), decreases in BMD, Tb.Th, Tb.N, and BV/TV, and increases in Tb.Sp and BS/BV (P<0.01). Compared with the model group, the JPHGP groups showed no obvious thinning of the femoral head or subchondroidal cystic degeneration. The high- and medium-dose JPHGP groups presented declines in the number of adipocytes and the rate of empty bone lacunae, an increase in the trabecular area (P<0.05, P<0.01), rises in BMD, Tb.Th, Tb.N, and BV/TV, and decreases in Tb.Sp and BS/BV (P<0.05, P<0.01). Compared with the normal group, the model group showcased raised serum levels of TG, TC, LDL, and ApoB and lowered serum levels of HDL and ApoA1 (P<0.01). Compared with the model group, the JPHGP groups had lowered serum levels of TG, TC, LDL, and ApoB (P<0.05, P<0.01) and a risen serum level of ApoA1 (P<0.05, P<0.01). Moreover, the serum level of HDL in the high-dose JPHGP group increased (P<0.01). A total of 19 different metabolites of disease set and drug set were screened out by oxylipidomics of the femoral head, and 119 core genes with restored expression were detected by transcriptomics. The enriched pathways were mainly concentrated in inflammation, lipids, apoptosis, and osteoclast differentiation. Molecular docking, immunohistochemistry, and Western blot results showed that compared with the normal group, the model group displayed increased content of 5-lipoxygenase (5-LO) and peroxisome proliferator-activated receptor γ (PPARγ) in the femoral head (P<0.01). Compared with the model group, medium- and high-dose JPHGP reduced the content of 5-LO and PPARγ (P<0.05, P<0.01). ConclusionJPHGP can restore the levels of oxidized lipid metabolites by regulating the 5-LO-PPARγ axis to treat SONFH in rats. Relevant studies provide experimental evidence for the efficacy mechanism of JPHGP in the treatment of SONFH.
3.Oxylipidomics Combined with Transcriptomics Reveals Mechanism of Jianpi Huogu Prescription in Treating Steroid-induced Osteonecrosis of Femoral Head in Rats
Lili WANG ; Qun LI ; Zhixing HU ; Qianqian YAN ; Liting XU ; Xiaoxiao WANG ; Chunyan ZHU ; Yanqiong ZHANG ; Weiheng CHEN ; Haijun HE ; Chunfang LIU ; Na LIN
Chinese Journal of Experimental Traditional Medical Formulae 2025;31(11):190-199
ObjectiveTo unveil the mechanism of Jianpi Huogu prescription (JPHGP) in ameliorating the dyslipidemia of steroid-induced osteonecrosis of the femur head (SONFH) by oxylipidomics combined with transcriptomics. MethodsSixty SD rats were assigned into normal, model, low-, medium-, and high-dose (2.5, 5, 10 g·kg-1, respectively) JPHGP, and Jiangushengwan (1.53 g·kg-1) groups. Lipopolysaccharide was injected into the tail vein at a dose of 20 μg·kg-1 on days 1 and 2, and methylprednisolone sodium succinate was injected at a dose of 40 mg·kg-1 into the buttock muscle on days 3 to 5. The normal group received an equal volume of normal saline. Drug administration by gavage began 4 weeks after the last injection, and samples were taken after administration for 8 weeks. Hematoxylin-eosin staining was conducted to reveal the histopathological changes of the femoral head, and the number of adipocytes, the rate of empty bone lacunae, and the trabecular area were calculated. Micro-computed tomography was used for revealing the histological and histomorphometrical changes of the femoral head. Enzyme-linked immunosorbent assay was employed to measure the serum levels of triglyceride (TG), total cholesterol (TC), low-density lipoprotein (LDL), high-density lipoprotein (HDL), apolipoprotein A1 (ApoA1), and apolipoprotein B (ApoB). At the same time, the femoral head was collected for oxylipidomic and transcriptomic detection. The differential metabolites and differential genes were enriched and analyzed, and the target genes regulating lipid metabolism were predicted. The predicted target proteins were further verified by molecular docking, immunohistochemistry, and Western blot. ResultsCompared with the normal group, the model group showcased thinning of the femoral head, trabecular fracture, karyopyknosis, subchondral cystic degeneration, increases in the number of adipocytes and the rate of empty bone lacunae (P<0.01), a reduction in the trabecular area (P<0.01), decreases in BMD, Tb.Th, Tb.N, and BV/TV, and increases in Tb.Sp and BS/BV (P<0.01). Compared with the model group, the JPHGP groups showed no obvious thinning of the femoral head or subchondroidal cystic degeneration. The high- and medium-dose JPHGP groups presented declines in the number of adipocytes and the rate of empty bone lacunae, an increase in the trabecular area (P<0.05, P<0.01), rises in BMD, Tb.Th, Tb.N, and BV/TV, and decreases in Tb.Sp and BS/BV (P<0.05, P<0.01). Compared with the normal group, the model group showcased raised serum levels of TG, TC, LDL, and ApoB and lowered serum levels of HDL and ApoA1 (P<0.01). Compared with the model group, the JPHGP groups had lowered serum levels of TG, TC, LDL, and ApoB (P<0.05, P<0.01) and a risen serum level of ApoA1 (P<0.05, P<0.01). Moreover, the serum level of HDL in the high-dose JPHGP group increased (P<0.01). A total of 19 different metabolites of disease set and drug set were screened out by oxylipidomics of the femoral head, and 119 core genes with restored expression were detected by transcriptomics. The enriched pathways were mainly concentrated in inflammation, lipids, apoptosis, and osteoclast differentiation. Molecular docking, immunohistochemistry, and Western blot results showed that compared with the normal group, the model group displayed increased content of 5-lipoxygenase (5-LO) and peroxisome proliferator-activated receptor γ (PPARγ) in the femoral head (P<0.01). Compared with the model group, medium- and high-dose JPHGP reduced the content of 5-LO and PPARγ (P<0.05, P<0.01). ConclusionJPHGP can restore the levels of oxidized lipid metabolites by regulating the 5-LO-PPARγ axis to treat SONFH in rats. Relevant studies provide experimental evidence for the efficacy mechanism of JPHGP in the treatment of SONFH.
4.Protective effect of sub-hypothermic mechanical perfusion combined with membrane lung oxygenation on a yorkshire model of brain injury after traumatic blood loss.
Xiang-Yu SONG ; Yang-Hui DONG ; Zhi-Bo JIA ; Lei-Jia CHEN ; Meng-Yi CUI ; Yan-Jun GUAN ; Bo-Yao YANG ; Si-Ce WANG ; Sheng-Feng CHEN ; Peng-Kai LI ; Heng CHEN ; Hao-Chen ZUO ; Zhan-Cheng YANG ; Wen-Jing XU ; Ya-Qun ZHAO ; Jiang PENG
Chinese Journal of Traumatology 2025;28(6):469-476
PURPOSE:
To investigate the protective effect of sub-hypothermic mechanical perfusion combined with membrane lung oxygenation on ischemic hypoxic injury of yorkshire brain tissue caused by traumatic blood loss.
METHODS:
This article performed a random controlled trial. Brain tissue of 7 yorkshire was selected and divided into the sub-low temperature anterograde machine perfusion group (n = 4) and the blank control group (n = 3) using the random number table method. A yorkshire model of brain tissue injury induced by traumatic blood loss was established. Firstly, the perfusion temperature and blood oxygen saturation were monitored in real-time during the perfusion process. The number of red blood cells, hemoglobin content, NA+, K+, and Ca2+ ions concentrations and pH of the perfusate were detected. Following perfusion, we specifically examined the parietal lobe to assess its water content. The prefrontal cortex and hippocampus were then dissected for histological evaluation, allowing us to investigate potential regional differences in tissue injury. The blank control group was sampled directly before perfusion. All statistical analyses and graphs were performed using GraphPad Prism 8.0 Student t-test. All tests were two-sided, and p value of less than 0.05 was considered to indicate statistical significance.
RESULTS:
The contents of red blood cells and hemoglobin during perfusion were maintained at normal levels but more red blood cells were destroyed 3 h after the perfusion. The blood oxygen saturation of the perfusion group was maintained at 95% - 98%. NA+ and K+ concentrations were normal most of the time during perfusion but increased significantly at about 4 h. The Ca2+ concentration remained within the normal range at each period. Glucose levels were slightly higher than the baseline level. The pH of the perfusion solution was slightly lower at the beginning of perfusion, and then gradually increased to the normal level. The water content of brain tissue in the sub-low and docile perfusion group was 78.95% ± 0.39%, which was significantly higher than that in the control group (75.27% ± 0.55%, t = 10.49, p < 0.001), and the difference was statistically significant. Compared with the blank control group, the structure and morphology of pyramidal neurons in the prefrontal cortex and CA1 region of the hippocampal gyrus were similar, and their integrity was better. The structural integrity of granulosa neurons was destroyed and cell edema increased in the perfusion group compared with the blank control group. Immunofluorescence staining for glail fibrillary acidic protein and Iba1, markers of glial cells, revealed well-preserved cell structures in the perfusion group. While there were indications of abnormal cellular activity, the analysis showed no significant difference in axon thickness or integrity compared to the 1-h blank control group.
CONCLUSIONS
Mild hypothermic machine perfusion can improve ischemia and hypoxia injury of yorkshire brain tissue caused by traumatic blood loss and delay the necrosis and apoptosis of yorkshire brain tissue by continuous oxygen supply, maintaining ion homeostasis and reducing tissue metabolism level.
Animals
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Perfusion/methods*
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Disease Models, Animal
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Brain Injuries/etiology*
;
Swine
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Male
;
Hypothermia, Induced/methods*
5.CFAP300 loss-of-function variant causes primary ciliary dyskinesia and male infertility via disrupting sperm flagellar assembly and acrosome formation.
Hua-Yan YIN ; Yu-Qi ZHOU ; Qun-Shan SHEN ; Zi-Wen CHEN ; Jie-Ru LI ; Huan WU ; Yun-Xia CAO ; Rui GUO ; Bing SONG
Asian Journal of Andrology 2025;27(6):743-750
Primary ciliary dyskinesia (PCD) is a genetically heterogeneous disorder characterized by impaired motility of cilia and flagella. Mutations in cilia- and flagella-associated protein 300 ( CFAP300 ) are associated with human PCD and male infertility; however, the underlying pathogenic mechanisms remain poorly understood. In a consanguineous Chinese family, we identified a homozygous CFAP300 loss-of-function variant (c.304delC) in a proband presenting with classical PCD symptoms and severe sperm abnormalities, including dynein arm deficiency and acrosomal malformation, as confirmed by transmission electron microscopy (TEM). Histological analysis revealed multiple morphological abnormalities of the sperm flagella in CFAP300 -mutant individual, whereas immunofluorescence demonstrated markedly reduced CFAP300 expression in the spermatozoa of the proband. Furthermore, tandem mass tag (TMT)-based quantitative proteomics showed that the CFAP300 mutation reduced key spermatogenesis proteins (e.g., sperm flagellar 2 [SPEF2], solute carrier family 25 member 31 [SLC25A31], and A-kinase anchoring protein 3 [AKAP3]) and mitochondrial ATP synthesis factors (e.g., SLC25A31, cation channel sperm-associated 3 [CATSPER3]). It also triggered abnormal increases in autophagy-related proteins and signaling mediator phosphorylation. These molecular alterations are likely to contribute to progressive deterioration of sperm ultrastructure and function. Notably, successful pregnancy was achieved via intracytoplasmic sperm injection (ICSI) using the proband's sperm. Overall, this study expands the known CFAP300 mutational spectrum and offers novel mechanistic insights into its role in spermatogenesis.
Humans
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Male
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Infertility, Male/pathology*
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Acrosome/pathology*
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Sperm Tail/pathology*
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Pedigree
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Spermatozoa
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Adult
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Loss of Function Mutation
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Ciliary Motility Disorders/genetics*
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Spermatogenesis/genetics*
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Female
6.Comparison of the therapeutic efficacy of different methods of anesthesia in microscopic varicocelectomy for the treatment of varicocele.
Qun-Sheng LI ; Ning-Hua LI ; Lei ZHOU ; Dong-Run LI ; Jie LU ; Chun-Yan HE ; Yu-Nu ZHOU ; Jian-Mo CHEN ; Wen-Tao YANG
National Journal of Andrology 2025;31(8):692-697
OBJECTIVE:
To compare the therapeutic efficacy and safety of local anesthesia and spinal anesthesia for the patients with varicocele (VC) who underwent microsurgical varicocelectomy (MV).
METHODS:
We retrospectively analyzed the data of VC patients who underwent MV treatment at the Andrology Department of the Affiliated Ruikang Hospital of Guangxi University of Chinese Medicine from May 2020 to March 2023. Cases with complete clinical data and follow-up evaluation were selected and divided into a control group (spinal anesthesia) and an observation group (local anesthesia) according to different anesthesia methods. The surgical time (including anesthesia time), visual analogue scale (VAS) score for pain, hospital stay, treatment cost, sperm concentration, forward motile sperm rate, and normal sperm morphology rate after three months of surgery, as well as postoperative complications and recurrence rate were compared between the two groups.
RESULTS:
A total of 107 eligible cases were included, with 56 cases in the control group and 51 cases in the observation group. There was no significant difference in the VAS score for pain during and after four hours of surgery, as well as postoperative complications, and recurrence rate between the two groups (P> 0.05). There was an significant increase in sperm concentration, forward motile sperm rate, and normal sperm morphology rate in both of two groups after three months of surgery (P<0.05). However, there was no significant difference between the two groups three months after surgery (P>0.05). The surgical time and hospital stay were shorter than those of the control group (P<0.05). And the treatment cost in observation group was lower than that of the control group (P<0.05).
CONCLUSION
Both local anesthesia and lumbar anesthesia for MV treatment of VC have good efficacy and safety. However, patients treated with MV under local anesthesia for VC have obvious advantages in terms of operation time (including anesthesia time), hospital stay, and treatment cost, which is worthy of clinical promotion and application.
Humans
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Male
;
Varicocele/surgery*
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Retrospective Studies
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Microsurgery
;
Anesthesia, Spinal
;
Adult
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Treatment Outcome
;
Anesthesia, Local
7.Expert consensus on the application of nasal cavity filling substances in nasal surgery patients(2025, Shanghai).
Keqing ZHAO ; Shaoqing YU ; Hongquan WEI ; Chenjie YU ; Guangke WANG ; Shijie QIU ; Yanjun WANG ; Hongtao ZHEN ; Yucheng YANG ; Yurong GU ; Tao GUO ; Feng LIU ; Meiping LU ; Bin SUN ; Yanli YANG ; Yuzhu WAN ; Cuida MENG ; Yanan SUN ; Yi ZHAO ; Qun LI ; An LI ; Luo BA ; Linli TIAN ; Guodong YU ; Xin FENG ; Wen LIU ; Yongtuan LI ; Jian WU ; De HUAI ; Dongsheng GU ; Hanqiang LU ; Xinyi SHI ; Huiping YE ; Yan JIANG ; Weitian ZHANG ; Yu XU ; Zhenxiao HUANG ; Huabin LI
Journal of Clinical Otorhinolaryngology Head and Neck Surgery 2025;39(4):285-291
This consensus will introduce the characteristics of fillers used in the surgical cavities of domestic nasal surgery patients based on relevant literature and expert opinions. It will also provide recommendations for the selection of cavity fillers for different nasal diseases, with chronic sinusitis as a representative example.
Humans
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Nasal Cavity/surgery*
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Nasal Surgical Procedures
;
China
;
Consensus
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Sinusitis/surgery*
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Dermal Fillers
8.Longitudinal study on catch-up growth in preterm infants with small for gestational age at corrected ages 0-24 months
Jia-Mei LI ; Qun-Ying XIE ; Yu-Qi WEN ; Yan-Yan SONG ; Hui-Ying LIANG ; Yan HU
Chinese Journal of Contemporary Pediatrics 2024;26(1):72-80
Objective To understand the growth and development status and differences between small for gestational age(SGA)and appropriate for gestational age(AGA)preterm infants during corrected ages 0-24 months,and to provide a basis for early health interventions for preterm infants.Methods A retrospective study was conducted,selecting 824 preterm infants who received regular health care at the Guangzhou Women and Children's Medical Center from July 2019 to July 2022,including 144 SGA and 680 AGA infants.The growth data of SGA and AGA groups at birth and corrected ages 0-24 months were analyzed and compared.Results The SGA group had significantly lower weight and length than the AGA group at corrected ages 0-18 months(P<0.05),while there were no significant differences between the two groups at corrected age 24 months(P>0.05).At corrected age 24 months,85%(34/40)of SGA and 79%(74/94)of AGA preterm infants achieved catch-up growth.Stratified analysis by gestational age showed that there were significant differences in weight and length at corrected ages 0-9 months between the SGA subgroup with gestational age<34 weeks and the AGA subgroups with gestational age<34 weeks and≥34 weeks(P<0.05).In addition,the weight and length of the SGA subgroup with gestational age≥34 weeks showed significant differences compared to the AGA subgroups with gestational age<34 weeks and≥34 weeks at corrected ages 0-18 months and corrected ages 0-12 months,respectively(P<0.05).Catch-up growth for SGA infants with gestational age<34 weeks and≥34 weeks mainly occurred at corrected ages 0-12 months and corrected ages 0-18 months,respectively.Conclusions SGA infants exhibit delayed early-life physical growth compared to AGA infants,but can achieve a higher proportion of catch-up growth by corrected age 24 months than AGA infants.Catch-up growth can be achieved earlier in SGA infants with a gestational age of<34 weeks compared to those with≥34 weeks.
9.Prevalence of comorbidity of hypertension, diabetes and dyslipidemia and the association between comorbidity and cardiovascular mortality in population aged 40 years and over in Liaoning Province
Li JING ; Yuanmeng TIAN ; Han YAN ; Qun SUN ; Shubao LI ; Shimin CUI ; Jixu SUN ; Lei SHI ; Yuyao MA ; Guangxiao LI ; Shuang LIU ; Liying XING
Chinese Journal of Cardiology 2024;52(11):1311-1316
Objective:To investigate the comorbidity status of hypertension, diabetes, and dyslipidemia (the"three diseases") among residents aged≥40 in Liaoning Province, and to explore the correlation between the comorbidity and cardiovascular disease mortality.Methods:This investigation was a prospective cohort study. From February 2017 to March 2019, a multi-stage stratified cluster random sampling method was used to carry out a baseline survey of 18 758 permanent residents aged≥40 years in Liaoning Province. Demographic information and history of hypertension, diabetes, and dyslipidemia were collected and followed up every year. Death was mainly identified by linkage to the Population Death Information Registration Management System. Cox proportional hazard regression model was used to analyze the association between the comorbidity of the "three diseases" and cardiovascular disease mortality risk.Results:A total of 18 758 residents aged≥40 in Liaoning Province were included, with an age of (60.3±9.9) years and 7 325 males (39.1%). The comorbidity rate of hypertension, diabetes, and dyslipidemia was 6.7% (1 256/18 758), and the standardized prevalence rate was 5.4%. The comorbidity rate increased with age (P<0.001), which was higher in women than in men, and more significant in urban areas than in rural areas (all P<0.001). The comorbidity of "three diseases" accounted for 39.3% (1 256/3 198), 18.7% (1 256/6 710), and 11.8% (1 256/10 653) in patients with diabetes, dyslipidemia, and hypertension, respectively. With a follow-up of (4.3±0.6) years, 463 people died of cardiovascular disease. The mortality rate of cardiovascular disease in the comorbidity of hypertension, diabetes, and dyslipidemia was 8.74/1 000 person-years. After adjusting potential confounders, Cox proportional hazard regression model analysis showed that compared with normal individuals, the hazard ratio of cardiovascular disease mortality in patients with the "three diseases" was 2.55 (95% CI: 1.63-3.99). Conclusion:The prevalence of comorbidity of hypertension, diabetes, and dyslipidemia among residents aged≥40 in Liaoning Province was relatively high, and the risk of cardiovascular disease mortality in patients with the "three diseases" was increased.
10.Effect of laser process parameters on the pores,surface roughness,and hardness of laser selective melting of den-tal cobalt-chrome alloys
Lei SANG ; Jiazhen YAN ; Ning LI ; Chenglai XIN ; Qun WANG ; Chang LIU
West China Journal of Stomatology 2024;42(4):462-469
Objective To address the quality problems caused by high porosity in the preparation of dental cobalt-chrome alloy prosthetics based on selective laser melting(SLM)technology,we investigated the influence mechanism of different forming process parameters on the microstructure and properties of the materials.Moreover,the range of form-ing process parameters that can effectively reduce defects was precisely defined.Methods The effects of laser power,scanning speed,and scanning distance on the pore properties,surface roughness,and hardness of dental cobalt-chrome al-loy were investigated by adjusting the printing parame-ters in the process of SLM.Through metallographic anal-ysis,image analysis,and molten pool simulation,the pore formation mechanism was revealed,and the relation-ship between the porosity and energy density of SLM dental cobalt-chrome alloy was elucidated.Results When the linear energy density was higher than 0.18 J/mm,the po-rosity defect easily appeared at the bottom of the molten pool.When the laser energy density was lower than 0.13 J/mm,defects occurred in the gap of the molten pool due to insufficient melting of powder.In particular,when the linear energy density exceeded the threshold of 0.30 J/mm or was below 0.12 J/mm,the porosity increased significantly to more than 1%.In addition,we observed a negative correlation between free surface roughness and energy density and an inverse re-lationship between macroscopic hardness and porosity.Conclusion On the basis of the conditions of raw materials and molding equipment used in this study,the key process parameters of SLM of molding parts with porosity lower than 1%were successfully determined.Specifically,these key parameters included the line energy density,which ranged from 0.13 J/mm to 0.30 J/mm,and the scan spacing should be strictly controlled below 90 μm.

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