1.Comparison between sinking and floating fresh Rehmanniae Radix samples by UHPLC-Q-Orbitrap HRMS, fingerprinting, and chemometrics.
Shi-Long LIU ; Hong-Wei ZHANG ; Zhen-Ling ZHANG ; Han-Ting JIA ; Zhi-Jun GUO ; Rui-Sheng WANG ; Hong-Wei ZHANG ; Shuo WANG ; Yi-Jian ZHONG
China Journal of Chinese Materia Medica 2025;50(14):3918-3929
This study aims to explore the scientific connotation of sinking Rehmanniae Radix has the best quality and compare the quality between floating and sinking fresh Rehmanniae Radix samples. Ultra-performance liquid chromatography tandem quadrupole electrostatic field Orbitrap high-resolution mass spectrometry(UHPLC-Q-Orbitrap HRMS) was employed to detect the chemical components in floating and sinking fresh Rehmanniae Radix samples. The fingerprint of fresh Rehmanniae Radix was established by high performance liquid chromatography(HPLC), and four index components were determined simultaneously. The cluster analysis, principal component analysis(PCA), and orthogonal partial least squares-discriminant analysis(OPLS-DA) were conducted to compare the quality of floating and sinking fresh Rehmanniae Radix samples. An evaporative light-scattering detector was used to compare the content of five sugars. The extract yield and drying rate were determined, and the quality connotation of sinking Rehmanniae Radix has the best quality was explained by multiple indicators. A total of 41 components were preliminarily identified from fresh Rehmanniae Radix by UHPLC-Q-Orbitrap HRMS, including 7 iridoid glycosides, 9 phenylethanol glycosides, 6 amino acids, 4 sugars, 3 phenolic acids, 5 nucleosides, 3 organic acids, 1 ionone, 1 furan, 1 coumarin, and 1 phenylpropanoid. The results showed that the main chemical components were consistent between floating and sinking fresh Rehmanniae Radix. Nine common peaks were identified in the fingerprints of 15 batches of floating and sinking fresh Rehmanniae Radix samples, and the similarity of fingerprints was greater than 0.9. The cluster analysis, PCA, and OPLS-DA classified floating and sinking fresh Rehmanniae Radix sasmples into two categories, indicating differences in the quality between them. The total content of catalpol, rehmannioside D, ajugol, and verbascoside in sinking fresh Rehmanniae Radix samples was higher than that in floating samples of the same batch and specification, and the main differential component was catalpol. The total content of fructose, glucose, sucrose, raffinose, and stachyose in sinking fresh Rehmanniae Radix samples was higher than that in floating samples of the same batch and specification, and the main differential component was stachyose. The extract yield and drying rate of the sinking samples were higher than those of floating samples. This study preliminarily showed that floating and sinking fresh Rehmanniae Radix samples had the same components but great differences in the content of medicinal substance basis. The total content of four glycosides and five sugars, extract yield, and drying rate of sinking fresh Rehmanniae Radix samples is higher than that of floating samples of the same batch and specification. These findings, to a certain extent, explains the scientificity of sinking Rehmanniae Radix has the best quality recorded in ancient books and provide a reference for the quality control and clinical application of fresh Rehmanniae Radix.
Chromatography, High Pressure Liquid/methods*
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Drugs, Chinese Herbal/chemistry*
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Rehmannia/chemistry*
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Chemometrics
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Mass Spectrometry/methods*
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Quality Control
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Principal Component Analysis
;
Plant Extracts
2.Lu'e Biyan Formula for Treatment of Allergic Rhinitis Patients with Fei (Lung)-Qi Deficiency-Coldness Syndrome: A Randomized, Double Blind, and Placebo-Controlled Trial.
Ming-Yue JIA ; Mei-Yi ZHANG ; Si-Yao XIAO ; Yang YU ; Xiang SHAO ; Chun-Sheng HAN ; Gui-Ling HAN
Chinese journal of integrative medicine 2025;31(11):1029-1036
OBJECTIVE:
To observe the clinical effect and safety of Lu'e Biyan Formula (LBF) combined with loratadine in the treatment of moderate to severe allergic rhinitis (AR) patients with Fei (Lung)-qi deficiency-coldness (FQDC) syndrome.
METHODS:
From September 2023 to December 2024, moderate to severe AR patients with FQDC syndrome were recruited from the Outpatient Department of Integrated Traditional Chinese and Western Medicine for Pulmonary Diseases Part 1, China-Japan Friendship Hospital. Participants were randomly assigned to a test group and a control group by using a random number table at a ratio of 1:1. Both groups received oral loratadine tablets (10 mg, once daily) for 2 weeks. In addition, the test group received oral LBF (30 mL, twice daily), and the control group received a placebo of LBF. Changes in the Total Nasal Symptom Score (TNSS), Total Non-nasal Symptom Score (TNNSS), Visual Analog Scale (VAS), Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ), and Chinese medicine (CM) syndrome scores before and after treatment were compared between groups. Moreover, the total effective rates and disease recurrence rates were compared. Adverse events (AEs) during the study period were also recorded.
RESULTS:
Totally 109 participants were recruited, and the full analysis set included 105 cases, 54 in the test group and 51 in the control group. Compared with the pre-treatment values, the scores of sneezing, runny nose, nasal obstruction, nasal itching, TNSS, TNNSS, VAS, RQLQ, and CM syndrome were significantly reduced in both groups at 1 and 2 weeks post-treatment and 12 weeks post-drug withdrawal (P<0.01). After treatment, the aforementioned scores in the test group were all markedly lower than those in the control group (P<0.01). Moreover, the total effective rate in the test group was higher than that in the control group (98.15% vs. 70.59%, P<0.01). After 12 weeks of drug withdrawal, there was no significant difference in the recurrence rate between groups (13.21% vs. 22.22%, P>0.05). No obvious AEs were observed in either group following treatment.
CONCLUSIONS
The combination of LBF with loratadine can effectively alleviate the symptoms of moderate to severe AR patients with FQDC syndrome, thereby improving their quality of life. This therapy demonstrated both precise effect and high safety. (Trial registration No. ITMCTR2025000589).
Humans
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Drugs, Chinese Herbal/therapeutic use*
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Male
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Rhinitis, Allergic/drug therapy*
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Female
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Adult
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Double-Blind Method
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Quality of Life
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Qi
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Middle Aged
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Loratadine/therapeutic use*
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Medicine, Chinese Traditional
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Syndrome
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Lung/drug effects*
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Young Adult
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Treatment Outcome
3.Specific effect of inserted sham acupuncture and its impact on the estimation of acupuncture treatment effect in randomized controlled trials: A systematic survey.
Xiao-Chao LUO ; Jia-Li LIU ; Ming-Hong YAO ; Ye-Meng CHEN ; Arthur Yin FAN ; Fan-Rong LIANG ; Ji-Ping ZHAO ; Ling ZHAO ; Xu ZHOU ; Xiao-Ying ZHONG ; Jia-Hui YANG ; Bo LI ; Ying ZHANG ; Xin SUN ; Ling LI
Journal of Integrative Medicine 2025;23(6):630-640
BACKGROUND:
The use of inserted sham acupuncture as a placebo in randomized controlled trials (RCTs) is controversial, because it may produce specific effects that cause an underestimation of the effect of acupuncture treatment.
OBJECTIVE:
This systematic survey investigates the magnitude of insert-specific effects of sham acupuncture and whether they affect the estimation of acupuncture treatment effects.
SEARCH STRATEGY:
PubMed, Embase and Cochrane Central Register of Controlled Trials were searched to identify acupuncture RCTs from their inception until December 2022.
INCLUSION CRITERIA:
RCTs that evaluated the effects of acupuncture compared to sham acupuncture and no treatment.
DATA EXTRACTION AND ANALYSIS:
The total effect measured for an acupuncture treatment group in RCTs were divided into three components, including the natural history and/or regression to the mean effect (controlled for no-treatment group), the placebo effect, and the specific effect of acupuncture. The first two constituted the contextual effect of acupuncture, which is mimicked by a sham acupuncture treatment group. The proportion of acupuncture total effect size was considered to be 1. The proportion of natural history and/or regression to the mean effect (PNE) and proportional contextual effect (PCE) of included RCTs were pooled using meta-analyses with a random-effect model. The proportion of acupuncture placebo effect was the difference between PCE and PNE in RCTs with non-inserted sham acupuncture. The proportion of insert-specific effect of sham acupuncture (PIES) was obtained by subtracting the proportion of acupuncture placebo effect and PNE from PCE in RCTs with inserted sham acupuncture. The impact of PIES on the estimation of acupuncture's treatment effect was evaluated by quantifying the percentage of RCTs that the effect of outcome changed from no statistical difference to statistical difference after removing PIES in the included studies, and the impact of PIES was externally validated in other acupuncture RCTs with an inserted sham acupuncture group that were not used to calculate PIES.
RESULTS:
This analysis included 32 studies with 5492 patients. The overall PNE was 0.335 (95% confidence interval [CI], 0.255-0.415) and the PCE of acupuncture was 0.639 (95% CI, 0.567-0.710) of acupuncture's total effect. The proportional contribution of the placebo effect to acupuncture's total effect was 0.191, and the PIES was 0.189. When we modeled the exclusion of the insert-specific effect of sham acupuncture, the acupuncture treatment effect changed from no difference to a significant difference in 45.45% of the included RCTs, and in 40.91% of the external validated RCTs.
CONCLUSION
The insert-specific effect of sham acupuncture in RCTs represents 18.90% of acupuncture's total effect and significantly affects the evaluation of the acupuncture treatment effect. More than 40% of RCTs that used inserted sham acupuncture would draw different conclusions if the PIES had been controlled for. Considering the impact of the insert-specific effect of sham acupuncture, caution should be taken when using inserted sham acupuncture placebos in RCTs. Please cite this article as: Luo XC, Liu JL, Yao MH, Chen YM, Fan AY, Liang FR, Zhao JP, Zhao L, Zhou X, Zhong XY, Yang JH, Li B, Zhang Y, Sun X, Li L. Specific effect of inserted sham acupuncture and its impact on the estimation of acupuncture treatment effect in randomized controlled trials: A systematic survey. J Integr Med. 2025; 23(6):630-640.
Acupuncture Therapy/methods*
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Humans
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Randomized Controlled Trials as Topic
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Placebo Effect
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Placebos
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Treatment Outcome
4.Serum Lipidomics Profiling to Identify Potential Biomarkers of Ischemic Stroke: A Pilot Study in Chinese Adults.
Ji Jun SHI ; Zu Jiao NIE ; Shu Yao WANG ; Hao ZHANG ; Xin Wei LI ; Jia Ling YAO ; Yi Bing JIN ; Xiang Dong YANG ; Xue Yang ZHANG ; Ming Zhi ZHANG ; Hao PENG
Biomedical and Environmental Sciences 2025;38(8):918-925
OBJECTIVE:
Lipid oxidation is involved in the pathogenesis of atherosclerosis and may be contribute to the development of Ischemic stroke (IS). However, the lipid profiles associated with IS have been poorly studied. We conducted a pilot study to identify potential IS-related lipid molecules and pathways using lipidomic profiling.
METHODS:
Serum lipidomic profiling was performed using LC-MS in 20 patients with IS and 20 age- and sex-matched healthy controls. Univariate and multivariate analyses were simultaneously performed to identify the differential lipids. Multiple testing was controlled for using a false discovery rate (FDR) approach. Enrichment analysis was performed using MetaboAnalyst software.
RESULTS:
Based on the 294 lipids assayed, principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) models were used to distinguish patients with IS from healthy controls. Fifty-six differential lipids were identified with an FDR-adjusted P less than 0.05 and variable influences in projection (VIP) greater than 1.0. These lipids were significantly enriched in glycerophospholipid metabolism (FDR-adjusted P = 0.009, impact score = 0.216).
CONCLUSIONS
Serum lipid profiles differed significantly between patients with IS and healthy controls. Thus, glycerophospholipid metabolism may be involved in the development of IS. These results provide initial evidence that lipid molecules and their related metabolites may serve as new biomarkers and potential therapeutic targets for IS.
Humans
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Pilot Projects
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Lipidomics
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Male
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Female
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Biomarkers/blood*
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Middle Aged
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Ischemic Stroke/blood*
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Aged
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China
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Lipids/blood*
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Adult
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Case-Control Studies
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East Asian People
5.Epidemiological Investigation of Dampness Syndrome Manifestations in the Population at Risk of Cerebrovascular Disease
Xiao-Jia NI ; Hai-Yan HUANG ; Qing SU ; Yao XU ; Ling-Ling LIU ; Zhuo-Ran KUANG ; Yi-Hang LI ; Yi-Kai ZHANG ; Miao-Miao MENG ; Yi-Xin GUO ; Xiao-Bo YANG ; Ye-Feng CAI
Journal of Guangzhou University of Traditional Chinese Medicine 2024;41(3):531-539
Objective To make an epidemiological investigation on traditional Chinese medicine(TCM)dampness syndrome manifestations in the population at risk of cerebrovascular diseases in Guangdong area.Methods A cross-sectional study was conducted to analyze the clinical data related to the risk of cerebrovascular diseases in 330 Guangdong permanent residents.The diagnosis of dampness syndrome,quantitative scoring of dampness syndrome and rating of the risk of stroke were performed for the investigation of the distribution pattern of dampness syndrome and its influencing factors.Results(1)A total of 306(92.73%)study subjects were diagnosed as dampness syndrome.The percentage of dampness syndrome in the risk group was 93.82%(258/275),which was slightly higher than that of the healthy group(48/55,87.27%),but the difference was not statistically significant(χ2 = 2.91,P = 0.112).The quantitative score of dampness syndrome in the risk group was higher than that of the healthy group,and the difference was statistically significance(Z =-2.24,P = 0.025).(2)Among the study subjects at risk of cerebrovascular disease,evaluation time(χ2 = 26.11,P = 0.001),stroke risk grading(χ2= 8.85,P = 0.031),and history of stroke or transient ischemic attack(TIA)(χ2 = 9.28,P = 0.015)were the factors influencing the grading of dampness syndrome in the population at risk of cerebrovascular disease.Conclusion Dampness syndrome is the common TCM syndrome in the population of Guangdong area.The manifestations of dampness syndrome are more obvious in the population with risk factors of cerebrovascular disease,especially in the population at high risk of stroke,and in the population with a history of stroke or TIA.The assessment and intervention of dampness syndrome should be taken into account for future project of stroke prevention in Guangdong.
6.Exploring Intervention Mechanism of Changzhou Tongbian Formula on Functional Constipation Combined with Depressive-like Behaviors in Rats Based on TRPV4-mediated BDNF/TrkB/CREB Signaling Pathway
Ling YAO ; Longfang QUAN ; Zhennian XIE ; Jie DAI ; Qiuning LIU ; Yonghai LI ; Xiaoqiang JIA
Traditional Chinese Drug Research & Clinical Pharmacology 2024;35(9):1289-1298
Objective To explore the intervention mechanism of Changzhou Tongbian Formula on functional constipation(FC)combined with depression in rats.Methods A rat model of FC combined with depressive-like behaviors was established by using gastric gavage of berberine hydrochloride and chronic unpredictable mild stress.The model rats were randomly divided into blank group,model group,lactulose group,and Changzhou Tongbian Formula high-,medium-,and low-dose groups,and the intervention was carried out for five weeks.The fecal water content was calculated before and after intervention.The small intestinal propulsion rate was calculated after intervention.The depressive-like behavior levels of rats were evaluated by forced swimming test and sucrose preference test before and after intervention.The colonic mucosal morphology was observed by HE staining.The morphology and number of pyramidal cells in the hippocampal CA1 and DG regions were observed by Nissl staining.The relative protein expression levels of the transient receptor potential vanilloid 4(TRPV4)in colonic tissue,as well as brain-derived neurotrophic factor(BDNF),tyrosine kinase receptor B(TrkB),mitogen-activated protein kinase(MAPK),and cAMP-response element binding protein(CREB)in the hippocampus of rats in each group were detected by Western Blot method.Results Compared with the blank group,the fecal water content of rats in the model group was significantly reduced(P<0.001),the small intestinal propulsion rate was significantly lower(P<0.01),the sucrose preference index was significantly decreased(P<0.001),the number of pyramidal cells in the CA1 and DG regions of the hippocampus was significantly reduced(P<0.001),and the TRPV4 in the colon and the BDNF,TrkB,MAPK,and CREB protein contents in the hippocampus were all significantly decreased(all P<0.001).Compared with the model group,the fecal water content of the Changzhou Tongbian Formula high-,midium-,low-dose groups and the lactulose group were significantly increased(P<0.001,P<0.01).The small intestinal propulsion rate of the Changzhou Tongbian Formula high-,low-dose groups and lactulose group were significantly increased(P<0.01,P<0.05).The sucrose preference indices of the Changzhou Tongbian Formula high-,midium-,low-dose groups and lactulose group were significantly increased(P<0.01,P<0.05).There was no abnormality in the colonic histology.The numbers of pyramidal cells in the CA1 and DG regions of the hippocampus of the Changzhou Tongbian Formula high-,midium-,low-dose groups and lactulose group were significantly increased(P<0.01,P<0.001).The TRPV4 content in the colon of the Changzhou Tongbian Formula high-,midium-,low-dose groups and lactulose group were significantly increased(P<0.001),and the BDNF,TrkB,MAPK,and CREB protein contents in the hippocampus were all significantly increased(P<0.05,P<0.01,P<0.001).Conclusion After intervention,Changzhou Tongbian Formula can significantly improve the TRPV4 content in the colon of model rats with the comorbidity of FC with depression,increase the moisture content of feces,promote intestinal peristalsis and improve constipation.Meanwhile,TRPV4 can activate the BDNF/TrkB/MAPK pathway,trigger an increase in downstream CREB,improve neuroplasticity and thus alleviate some depressive-like behavior.
7.Expression and mechanism of N6-methyladenosine methylation-related factors in the repair of skeletal muscle injury in mice
Jia-Yin LU ; Zhi-Chao YAO ; Xiao-Jing HAO ; Yi YAN ; Pei MA ; Hui-Ling ZHANG ; Hai-Dong WANG
Acta Anatomica Sinica 2024;55(3):285-294
Objective To investigate the dynamic expression with the time change of N6-methyladenosine(m6A)methylation-related factors in the repair process of skeletal muscle injury and its mechanism in the inflammatory response of macrophage in the injure process.Methods In vivo mice models of BaCl2 injury in the gastrocnemius were established.Four mice per group in the control group and injury group.Gastrocnemius tissues were harvested at day 1,3,5,7,and 9 after injury for experiments.Primary gastrocnemius muscle tissue cells,muscle satellite cells,muscle cells,and cell line C2C12 cells were treated with dexamethasone(DEX,50 μmol/L)to mimic injury.Lipopolysaccharide(LPS,100 μg/L)induced RAW264.7 cell lines to mimic the inflammatory response after skeletal muscle injury,and STM2457(30 μmol/L)was added to inhibit the effect of methyltransferase 3(Mettl3)before LPS treatment.The expression of m6A methylation-related factors(Writers,Erasers,Readers)and inflammation factors were detected by Real-time PCR and Western blotting.Results The muscle fibers were dissolved and then gradually repaired with the extension of injury time,the number of monocytes/macrophages increased first and then decreased,and the Pax7 mRNA level increased first and then decreased with the change of injury time.Compared with the control group,the mRNA and protein levels of m6A methylation-related factors in gastrocnemius did not change significantly on the injury-1 day.However,they were significantly increased on the injury-3 days compared with the control group(P<0.05),and then obviously decreased on the injury-5 days group compared with the injury-3 days group(P<0.05).Compared with the control group,they were no significant differences on the injury-7 days group and-9 days group.In vitro DEX decreased the mRNA levels of m6A methyltransferase factors in primary muscle satellite cells and C2C12 cells and increased the mRNA expression level of methylation-recognition enzyme factors(P<0.05).The mRNA levels of m6A methylation-related factors increased significantly in skeletal muscle tissue cells and myocytes after DEX treatment(P<0.05).After LPS treatment,the mRNA and protein expression levels of m6A methylation-related factors and the mRNA expression levels of inflammatory factors interleukin(IL)-6 and IL-1β in macrophages increased significantly(P<0.05),while the levels of IL-6 and IL-1β mRNA in macrophages decreased significantly when the Mettl3 was inhibited(P<0.05).Conclusion m6A methylation-related factors primarily is activated in the damaged muscle cells and inflammation response of macrophages.Inhibition of m6A methyltransferase can reduce the inflammatory response of macrophages.
8.Research progress on processing technology,chemical constituents and pharmacological activities of Polygoni multiflori radix praeparata
Rui YAO ; Hong GUO ; Xiaoshu ZHANG ; Ying WANG ; Xiaohan GUO ; Jia CHEN ; Jinhao LI ; Ling XU ; Jianbo YANG ; Wenguang JING ; Xianlong CHENG ; Feng WEI
China Pharmacist 2024;28(11):523-535
Polygoni multiflori radix praeparata is a processed product of Polygoni multiflori radix(Polygonum multiflorum Thunb.),and its main components include stilbene glycosides,anthraquinones,flavonoids,alkaloids,phenolic acids,etc.It has antioxidant,antianemic,anti-tumor,hypoglycemic,anti-inflammatory effects,etc,and is widely used in clinical practice.The processing technology is mainly stewinging with black bean juice,steaming,processing for 9 times and braising and simmering.After processing,the color deepens and the content of composition changes.By consulting domestic and foreign literature,the research on Polygoni multiflori radix praeparata is not comprehensive enough compared with Polygoni multiflori radix.Therefore,this paper mainly summarizes the processing technology,chemical composition and pharmacological activity of Polygoni multiflori radix preparata reported in the past 20 years,and provides a reference for further development of Polygoni multiflori radix preparata.
9.Temporal trend of the global prevalence rate of tension-type headache in children and adolescents in 1990-2021
Ling-Zi YAO ; De-Nan JIANG ; Jing WU ; Guang-Dian SHEN ; Jin CAO ; Si-Qing CHENG ; Shi-Yi SHAN ; Ze-Yu LUO ; Jia-Li ZHOU ; Pei-Ge SONG
Chinese Journal of Contemporary Pediatrics 2024;26(10):1058-1065
Objective To investigate the prevalence of tension-type headache(TTH)in children and adolescents aged 0-19 years globally in 1990-2021,and to provide a basis for the prevention and treatment of TTH.Methods Based on the Global Burden of Disease Study data,the age-standardized prevalence distribution of TTH and its changing trend were analyzed among the children and adolescents aged 0-19 years,with different sexes,age groups,sociodemographic index(SDI)regions and countries/territories.Results The age-standardized prevalence rate(ASPR)of TTH in children and adolescents aged 0-19 globally in 2021 was 17 339.89/100 000,which was increased by 1.73%since 1990.The ASPR in females was slightly higher than that in males(1990:17 707.65/100 000 vs 16 403.78/100 000;2021:17 946.29/100 000 vs 16 763.09/100 000).The ASPR in adolescence was significantly higher than that in school-aged and preschool periods(1990:27 672.04/100 000 vs 10 134.16/100 000;2021:28 239.04/100 000 vs 10 059.39/100 000).Regions with high SDI exhibited a higher ASPR than the other regions,with significant differences in prevalence rates across different countries.From 1990 to 2021,there was a slight increase in global ASPR,with an average annual percentage change(AAPC)of 0.06%.Females experienced a smaller increase than males based on AAPC(0.04%vs 0.07%).There was reduction in ASPR in preschool and school-aged groups,with an AAPC of-0.02%,while there was a significant increase in ASPR in adolescence,with an AAPC of 0.07%.ASPR decreased in regions with low-middle and low levels of SDI,with an AAPC of-0.02%and-0.04%,respectively,while it increased in regions with middle SDI,with an AAPC of 0.24%.Conclusions There is a consistent increase in the ASPR of TTH in children and adolescents aged 0-19 years globally,with significant differences across sexes,age groups,SDI regions and countries/territories.
10.Development of low-oxygen mixed gas generator for pilot hypoxia testing
Lin-Xia LI ; Jia-Ling XU ; Guo-Yun MAO ; Yao-Xuan JI ; Jin MA ; Yun-Ying WANG
Chinese Medical Equipment Journal 2024;45(7):24-28
Objective To develop a low-oxygen mixed gas generator to make up for the deficiencies of low-pressure chambers and load-resistant hypoxia trainers during pilot hypoxia tolerance testing.Methods The device prepared the low-oxygen gas with the principle of gas separation,which was composed of a Sunsource OLF1100D-220AF air compressor,a SMC IDG75SAM4-03 filter,a buffer tank,an AIR Products PA3010 integrated assembly,a control box,sensors and regulators.The sensors included the pressure sensor,flow sensor,concentration sensor and dew point temperature sensor,and the control box consisted of a main control board,a power supply module,a transmission module,a communication module,a display and a housing.The embedded control software of the device was developed with KEIL 5 and C++.Results The device developed prepared the low-oxygen gas with the volume fraction being 4%to 18%and the maximum error of volume fraction being 0.05%,and the main components of the prepared gas met the technical requirements of medical oxygen as stipulated in GB 8982-2009 Oxygen supplies for medicine and aircraft breathing.Conclusion The low-oxygen gas prepared by the device has its volume fraction precisely controlled and can be used for hypoxia tolerance testing and acclimation training for pilots.[Chinese Medical Equipment Journal,2024,45(7):24-28]

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