1.Effects of metformin on gut microbiota and short-/medium-chain fatty acids in high-fat diet rats.
Ying SHI ; Lin XING ; Shanyu WU ; Fangzhi YUE ; Tianqiong HE ; Jing ZHANG ; Lingxuan OUYANG ; Suisui GAO ; Dongmei ZHANG ; Zhijun ZHOU
Journal of Central South University(Medical Sciences) 2025;50(5):851-863
OBJECTIVES:
Recent evidence suggests that the gut may be a primary site of metformin action. However, studies on the effects of metformin on gut microbiota remain limited, and its impact on gut microbial metabolites such as short-/medium-chain fatty acids is unclear. This study aims to investigate the effects of metformin on gut microbiota, short-/medium-chain fatty acids, and associated metabolic benefits in high-fat diet rats.
METHODS:
Twenty-four Sprague-Dawley rats were randomly divided into 3 groups: 1) Normal diet group (ND group), fed standard chow; 2) high-fat diet group (HFD group), fed a high-fat diet; 3) high-fat diet + metformin treatment group (HFD+Met group), fed a high-fat diet for 8 weeks, followed by daily intragastric administration of metformin solution (150 mg/kg body weight) starting in week 9. At the end of the experiment, all rats were sacrificed, and serum, liver, and colonic contents were collected for assessment of glucose and lipid metabolism, liver pathology, gut microbiota composition, and the concentrations of short-/medium-chain fatty acids.
RESULTS:
Metformin significantly improved HFD-induced glucose and lipid metabolic disorders and liver injury. Compared with the HFD group, the HFD+Met group showed reduced abundance of Blautia, Romboutsia, Bilophila, and Bacteroides, while Lactobacillus abundance significantly increased (all P<0.05). Colonic contents of butyric acid, 2-methyl butyric acid, valeric acid, octanoic acid, and lauric acid were significantly elevated (all P<0.05), whereas acetic acid, isoheptanoic acid, and nonanoic acid levels were significantly decreased (all P<0.05). Spearman correlation analysis revealed that Lactobacillus abundance was negatively correlated with body weight gain and insulin resistance, while butyrate and valerate levels were negatively correlated with insulin resistance and liver injury (all P<0.05).
CONCLUSIONS
Metformin significantly increases the abundance of beneficial bacteria such as Lactobacillus and promotes the production of short-/medium-chain fatty acids including butyric, valeric, and lauric acid in the colonic contents of HFD rats, suggesting that metformin may regulate host metabolism through modulation of the gut microbiota.
Animals
;
Metformin/pharmacology*
;
Rats, Sprague-Dawley
;
Diet, High-Fat/adverse effects*
;
Rats
;
Gastrointestinal Microbiome/drug effects*
;
Male
;
Fatty Acids, Volatile/metabolism*
;
Fatty Acids/metabolism*
2.NLRP3 signaling pathway promotes hepatocyte pyroptosis in mice with nonalcoholic steatohepatitis in hypoxic environment.
Shanyu LUO ; Qiang ZHU ; Yufei YAN ; Zonghong JI ; Huajie ZOU ; Ruixia ZHANG ; Yinggui BA
Journal of Southern Medical University 2025;45(9):2026-2033
OBJECTIVES:
To investigate the regulatory role of the NLRP3 signaling pathway in hepatocyte pyroptosis in nonalcoholic steatohepatitis (NASH) under hypoxia.
METHODS:
Twenty-four male C57BL/6 mice were randomized equally into hypoxic control (A), hypoxic NASH model (B), hypoxic NASH+NLRP3 inhibitor (C), and hypoxic NASH+caspase-1 inhibitor (D) groups. In groups B-D, the mice were fed a methionine choline-deficient (MCD) diet under hypoxic conditions (to simulate a 5000 m altitude) for 6 weeks; the mice in groups C and D received intraperitoneal injections of the respective inhibitors every other day.
RESULTS:
Compared with those in group A, the mice in group B showed significantly elevated serum levels of FBG, TC, TG, ALT and AST, increased liver lipid content, inflammatory cell infiltration and collagen fiber deposition, and enhanced hepatic expressions of NLRP3, caspase-1, IL-1β and GSDMD proteins, with obvious swelling, cristae breakage, vacuolization, and outer membrane disruption of the mitochondria, ribosome loss in the cytoplasm, destruction of the nuclear membrane, and pathological changes of the rough endoplasmic reticulum. Treatment with NLRP3 inhibitor and caspase-1 inhibitor both significantly lowered serum levels of TC, TG, ALT and AST (but without significantly affecting FBG) in the mouse models, and reduced liver lipid content, inflammatory cell infiltration, collagen deposition, and expression levels of NLRP3, caspase-1, GSDMD and IL-1β. The treatments also significantly improved pathological changes in the mitochondria, ribosomes and endoplasmic reticulum in liver tissues of the mice.
CONCLUSIONS
NLRP3 signaling pathway plays a key role in promoting hepatocyte pyroptosis in NASH mice under hypoxic condition, and inhibiting this pathway can effectively reduce liver inflammation, suggesting its potential as a therapeutic target for NASH treatment.
Animals
;
Non-alcoholic Fatty Liver Disease/metabolism*
;
NLR Family, Pyrin Domain-Containing 3 Protein/metabolism*
;
Pyroptosis
;
Mice, Inbred C57BL
;
Male
;
Hepatocytes/pathology*
;
Signal Transduction
;
Mice
;
Hypoxia/metabolism*
;
Caspase 1/metabolism*
;
Interleukin-1beta/metabolism*
;
Liver/metabolism*
3.Impact of health education interventions on the proper use of respiratory protective equipment among dust-exposed workers
Yuhao WANG ; Zhao ZHANG ; Jinyi LU ; Shanyu ZHOU ; Xiaoxin LI ; Zhiming ZHUANG ; Manjia GONG ; Qiaoli WEI ; Shuling HUANG ; Luyao XU ; Xudong LI
China Occupational Medicine 2025;52(5):552-557
Objective To investigate the impact of various health education intervention strategies on the proper use of personal respiratory protective equipment (RPE) among workers exposed to dust. Methods Dust-exposed workers were recruited from 60 selected enterprises in Guangdong Province using cluster random sampling method. They were randomly allocated to the control, low-intensity intervention, and high-intensity intervention groups, with 358, 346, and 371 workers in each group, respectively. Workers in the control group received no designed intervention. Workers in the low-intensity intervention group received traditional plus mobile health education on the proper use of RPE. Workers in the high-intensity intervention group received all components of the low-intensity intervention, supplemented with peer education. The intervention lasted for six months. RPE usage was compared among the three groups of workers before and after the intervention. Results Workers in the control, low-intensity intervention, and high-intensity intervention groups showed higher rates of both RPE wearing and correct RPE wearing after the intervention than before it within their respective groups (RPE wearing rate: 94.1% vs 99.2%, 95.7% vs 100.0%, 94.6% vs 100.0%, all P<0.01; correct RPE wearing rate: 66.8% vs 91.1%, 67.3% vs 95.7%, 66.6% vs 96.5%, all P<0.01). Post-intervention correct RPE wearing rates were highest in the high-intensity intervention group, followed by the low-intensity intervention group, and the control group, with the percentage of 96.50%, 95.66% and 91.06%, respectively (P<0.01). Binary logistic regression analysis result showed that different intervention strategies affected the correct use of personal RPE among dust-exposed workers after adjusting for gender, age, and other confounding factors (P<0.05). Compared with the control group, the rates of correct RPE use increased in the low-intensity intervention group and the high-intensity intervention group (odd ratio was 2.14 and 3.01; 95% confidence interval was 1.12 - 4.10 and 1.53 - 5.91, respectively). Conclusion The implementation of traditional plus mobile health education interventions on the proper use of RPE can promote correct RPE utilization among dust-exposed workers, and integrating peer education further enhances the intervention effectiveness.
4.Cross-sectional survey on occupational health literacy of manufacturing workers in Bao′an District, Shenzhen City
Liyin ZHANG ; Jun CHEN ; Yijia GUO ; Shanyu ZHOU ; Min YANG
China Occupational Medicine 2025;52(4):426-430
Objective To analyze the current occupational health literacy (OHL) level and its influencing factors among manufacturing workers in Bao'an District, Shenzhen City. Methods The front-line workers of manufacturing enterprises from seven key industries in two streets of Bao'an District were selected as the research subjects using a stratified cluster random sampling method. The Occupational Health Literacy Questionnaire of National Key Populations was used to online investigate their OHL level. Multivariable logistic regression analysis was used to screen the influencing factors of OHL. Results A total of 633 front-line workers of manufacturing enterprises were surveyed, and 283 had OHL, with an overall OHL level of 44.7%. The levels of literacy across different dimensions, from high to low, were basic knowledge of occupational health protection (84.5%), legal knowledge of occupational health (41.5%), health behaviors and practices (41.2%), and basic skills for occupational health protection (22.0%). The results of the multivariable logistic regression analysis showed that younger age, higher educational level, and higher personal monthly income, were related to higher OHL level among the workers (all P<0.05). Conclusion The OHL level of manufacturing workers in Bao'an District, Shenzhen City still has room for improvement. Efforts should focus on workers with low education levels, low incomes, and older ages, with targeted training in theoretical knowledge to improve the practical application of basic skills for occupational health protection, to improve their OHL.
5.Early cellular immune exhaustion in patients with Epstein-Barr virus activation following haploidentical hematopoietic stem cell transplantation
Yifei HUANG ; Shanyu ZHANG ; Jiabao HE ; Ya ZHOU ; Rongtao XUE ; Zhiping FAN ; Fen HUANG ; Na XU ; Jing SUN ; Qifa LIU ; Ren LIN
Chinese Journal of Hematology 2024;45(11):998-1004
Objective:This study aimed to investigate the association between early immune reconstitution and Epstein-Barr virus (EBV) reactivation by analyzing changes in natural killer (NK), B, and T cells and their functional status in the peripheral blood during the early post-transplant period.Methods:This study included 23 patients who underwent haplo-hematopoietic stem cell transplantation (HSCT). The immune reconstitution of NK cells, T cells, and B cells as well as the expression levels of NK and T cell exhaustion markers (PD-1, TIM-3, and CTLA-4) and cytotoxic function at 1, 2, and 3 months post-transplantation were compared between patients with EBV activation (EBV+ group) and those without activation (EBV- group) post- transplantation.Results:EBV activation occurred in nine patients post-transplantation (EBV+ group), whereas 14 patients demonstrated no activation (EBV- group). All patients with EBV activation exhibited EBV viremia, and no EBV-associated diseases occurred. No significant differences in the clinical characteristics were found between the two groups of patients. The median proportion of CD3 +CD8 + T cells in the EBV+ group was significantly lower than that in the EBV- group at 1 month post-transplantation ( P=0.033). The median proportion of the CD3 -CD16 negCD56 bri subset in the EBV+ group was significantly higher than that in the EBV- group at 2 months post-transplantation ( P=0.046). No significant differences in the median proportions of CD3 -CD19 + B cells were observed between the two groups at 1, 2, and 3 months post-transplantation. The expression of CTLA-4 on CD3 -CD16 briCD56 dim NK cells in the EBV+ group was significantly higher than that in the EBV- group at 1 month post-transplantation ( P=0.033). The expression of TIM-3 on CD3 +CD8 + T cells in the EBV+ group was significantly higher than that in the EBV- group ( P=0.009). The expression level of TIM-3 on CD3 -CD16 negCD56 dim NK cells in the EBV+ group was significantly lower than that in the EBV- group at 2 months post-transplantation ( P=0.023). The expression levels of TIM-3 on CD3 +CD4 + T cells in the EBV+ group than those in the EBV- group at 1 and 3 months post-transplantation ( P=0.002, P=0.043). The median positive rate of Granzyme B expression in CD3 +CD8 + T cells and CD3 +CD4 + T cells in the EBV+ group was significantly lower than that in the EBV- group at 1-month post-transplantation ( P=0.033, P=0.016). The median positive rate of Granzyme B expression in the CD3 -CD16 briCD56 neg cell subset in the EBV+ group was higher than that in the EBV- group at 2 months post-transplantation ( P=0.012). The median positive rate of Granzyme B expression in CD3 +CD4 + T cells in the EBV+ group remained significantly lower than that in the EBV- group at 2 months post-transplantation ( P=0.049). The median positive rate of perforin expression in the CD3 -CD16 briCD56 dim cell subset was significantly higher in the EBV+ group than in the EBV- group at 3 months post-transplantation ( P=0.003). The median positive rate of IFN-γ expression in CD3 +CD8 + T cells in the EBV+ group was significantly lower than that in the EBV- group at 3 months post-transplantation ( P=0.036) . Conclusion:Delayed NK cell and T lymphocyte reconstitution, high exhaustion marker expression, and weakened cytotoxic functions may be related to EBV reactivation after haploidentical HSCT.
6.Optimization of Preparation Technology of Xinqingduyin Granules Based on Characteristic Chromato-grams and Index Components
Xiaomeng LU ; Yuzheng GU ; Ruimei LIU ; Yinhui LIN ; Shanyu ZHOU ; Xinxin HE ; Fei XIAO ; Jun ZHANG ; Xin'an HUANG
Traditional Chinese Drug Research & Clinical Pharmacology 2024;35(2):263-273
Objective To establish high performance liquid chromatography(HPLC)characteristic chromatograms of Xinqingduyin Granules(composed of Taraxaci Herba,Lonicerae Japonicae Flos,Chrysanthemi Indici Flos,etc.)and content determination of chicory acid and glycyrrhizic acid,and to optimize the preparation process of Xinqingduyin Granules.Methods Using the characteristic chromatograms of Xinqingduyin and the retention rate of chicory acid and glycyrrhizic acid as indexes,we carried out orthogonal experiment to optimize the extraction process of Xinqingduyin,and studied the concentration process.The molding process of Xinqingduyin Granules was conducted by screening the types and dosage of auxiliary materials,then three batches of pilot experiments were carried out.Results HPLC characteristic chromatograms of Xinqingshuyin Granules and the determination methods of chicory acid and glycyrrhizic acid were established.The optimal preparation technology was as follows:8 times amount of water was added,the drug was decocted for 3 times,with 1 hour per time.After the extract was concentrated under reduced pressure at 80℃,the appropriate amount of steviol glycoside and lactose was added into the extract and mixed.One-step granulation and packaging were adopted.The retention rates of chicoric acid and glycyrrhizic acid in the 3 batches of Xinqingduyin Granules,which were prepared on the pilot scale,were(54.56±1.63)%and(54.96±1.08)%,and the rate of finished product was(87.47±0.49)%,respectively.The quality is uniform,and the characteristic map of Xinqingduyin Granules showed high similarity with that of decoction prepared from the same batch of slices.Conclusion The optimized preparation technology is reasonable,feasible and reproducible.This preparation can be used to obtain the granule with similar materials of Xinqingduyin decoction.
7.Introduction to the revision of Diagnostic Standard for Occupational Medicamentose-like Dermatitis due to Trichloroethylene
Lihua XIA ; Ying ZHANG ; Xiaofeng DENG ; Shanyu ZHOU ; Yongshun HUANG ; Xiying LI ; Qifeng WU ; Muwei CAI ; Xiaowen LUO ; Fengling ZHAO
China Occupational Medicine 2024;51(1):37-42
With the development of clinical related disciplines, the update and establishment of relevant standards/guidelines at home and abroad, GBZ 185-2006 Diagnostic Criteria for Occupational Medicamentose-like Dermatitis due to Trichloroethylene (hereinafter referred to as “GBZ 185-2006”) was unable to meet clinical needs. Therefore, the GBZ 185-2006 was revised based on the principles of evidence-based medicine, in accordance with relevant laws/regulations and relevant standards/guidelines in combination with review of research data on occupational medicamentose-like dermatitis due to trichloroethylene (OMDT) home and abroad, and the development of clinical practice and clinical related disciplines. The main modifications include: adding terms and definitions of OMDT, modifying the description of clinical manifestations of the diagnostic principles, adjusting the description of latency, deleting the diagnostic requirement of the incidence probability, adding the specific allergen patch test as the etiological diagnostic index, standardizing the application scope, operating procedure and precautions of the specific allergen patch test. In addition, the relevant content of “Basic Characteristics and Clinical Types of Skin Damage of Medicamentose-like Dermatitis due to Trichloroethylene” in Appendix A is improved, the treatment principles are revised, and the content of new progress in treatment, artificial liver application, are added. The revised GBZ 185-2024 Diagnostic Standard for Occupational Medicamentose-like Dermatitis due to Trichloroethylene is more scientific and practical, and can provide technical basis for the standardized diagnosis and treatment of OMDT in medical and health institutions.
8.Effect of lncRNA NEAT1 on radiosensitivity in breast cancer cells by regulating miR-149-5p/GPT2 axis
Dandan WANG ; Tingyin JIANG ; Guanjie ZHANG ; Shanyu WU
Chinese Journal of Radiation Oncology 2024;33(4):353-359
Objective:To evaluate the effect of long non-coding RNA (lncRNA) nuclear enriched abundant transcript 1 (NEAT1) on the radiosensitivity in breast cancer cells by regulating the miR-149-5p/ glutamic pyruvic transaminase 2 (GPT2) axis.Methods:Real-time reverse transcription PCR (RT-qPCR) was used to detect NEAT1, miR-149-5p and glutamic pyruvic transaminase 2 (GPT2) mRNA levels in human breast cells MCF-10A, and human breast cancer cells MCF-7, MDA-MB-231 and MDA-MB-468, respectively. MCF-7 cells were divided into 0, 2, 4, 6 and 8 Gy irradiation groups. MCF-7 cells were divided into NEAT1 knockdown (si-NEAT1) group and control (si-NC) group, NEAT1 knockdown +miR-149-5p knockdown (si-NEAT1+anti-miR-149-5p) group and control (si-NEAT1+anti-miR-NC) group, NEAT1 knockdown + GPT2 overexpression (si-NEAT1+GPT2) group and control (si-NEAT1+NC) group. On the basis of the above grouping, irradiate each group of cells with 4 Gy radiation for 2 h, denoted as IR+si-NEAT1, IR+si-NC, IR+si-NEAT1+anti-miR-149-5p, IR+si-NEAT1+anti-miR-NC, IR+si-NEAT1+GPT2, IR+si-NEAT1+NC groups. Subsequently, MCF-7 cells were irradiated at a dose of 4 Gy and divided into the IR+si-NEAT1, IR+si-NC, IR+si-NEAT1+anti-miR-149-5p, IR+si-NEAT1+anti-miR-NC, IR+si-NEAT1+GPT2 and IR+si-NEAT1+NC groups. RT-qPCR was used to detect NEAT1, miR-149-5p, GPT2 mRNA levels in cells. Colony formation assay was used to detect cell radiosensitivity. CCK-8 assay was adopted to detect cell proliferation ability. The binding sites of NEAT1 and miR-149-5p were predicted by StarBase database. The binding sites of miR-149-5p and GPT2 were predicted by Targetscan database, and validated by dual luciferase assay. Single factor ANOVA was used for inter-group comparisons. LSD- t test was used for pairwise comparison. Results:Compared with MCF-10A cells, NEAT1 and GPT2 mRNA levels in cell lines were up-regulated, whereas miR-149-5p level was down-regulated (all P<0.05). Compared with the 0 Gy dose group, NEAT1 and GPT2 mRNA levels were down-regulated, while miR-149-5p levels were up-regulated in the 2, 4, 6, and 8 Gy dose groups (all P<0.05). Knockdown of NEAT1 expression or radiation alone could enhance cell radiosensitivity, and reduce cell proliferation ability (all P<0.05). Simultaneous radiation treatment with knockdown of NEAT1 expression could strengthen the above effects upon cells (all P<0.05). Knockdown of miR-149-5p expression or overexpression of GPT2 could partially reverse the aforementioned effects of knockdown of NEAT1 expression (all P<0.05). Conclusion:Knockdown of NEAT1 expression enhances breast cancer cell radiosensitivity, and reduces cell proliferation ability by regulating the miR-149-5p/GPT2 signal axis.
9.Early cellular immune exhaustion in patients with Epstein-Barr virus activation following haploidentical hematopoietic stem cell transplantation
Yifei HUANG ; Shanyu ZHANG ; Jiabao HE ; Ya ZHOU ; Rongtao XUE ; Zhiping FAN ; Fen HUANG ; Na XU ; Jing SUN ; Qifa LIU ; Ren LIN
Chinese Journal of Hematology 2024;45(11):998-1004
Objective:This study aimed to investigate the association between early immune reconstitution and Epstein-Barr virus (EBV) reactivation by analyzing changes in natural killer (NK), B, and T cells and their functional status in the peripheral blood during the early post-transplant period.Methods:This study included 23 patients who underwent haplo-hematopoietic stem cell transplantation (HSCT). The immune reconstitution of NK cells, T cells, and B cells as well as the expression levels of NK and T cell exhaustion markers (PD-1, TIM-3, and CTLA-4) and cytotoxic function at 1, 2, and 3 months post-transplantation were compared between patients with EBV activation (EBV+ group) and those without activation (EBV- group) post- transplantation.Results:EBV activation occurred in nine patients post-transplantation (EBV+ group), whereas 14 patients demonstrated no activation (EBV- group). All patients with EBV activation exhibited EBV viremia, and no EBV-associated diseases occurred. No significant differences in the clinical characteristics were found between the two groups of patients. The median proportion of CD3 +CD8 + T cells in the EBV+ group was significantly lower than that in the EBV- group at 1 month post-transplantation ( P=0.033). The median proportion of the CD3 -CD16 negCD56 bri subset in the EBV+ group was significantly higher than that in the EBV- group at 2 months post-transplantation ( P=0.046). No significant differences in the median proportions of CD3 -CD19 + B cells were observed between the two groups at 1, 2, and 3 months post-transplantation. The expression of CTLA-4 on CD3 -CD16 briCD56 dim NK cells in the EBV+ group was significantly higher than that in the EBV- group at 1 month post-transplantation ( P=0.033). The expression of TIM-3 on CD3 +CD8 + T cells in the EBV+ group was significantly higher than that in the EBV- group ( P=0.009). The expression level of TIM-3 on CD3 -CD16 negCD56 dim NK cells in the EBV+ group was significantly lower than that in the EBV- group at 2 months post-transplantation ( P=0.023). The expression levels of TIM-3 on CD3 +CD4 + T cells in the EBV+ group than those in the EBV- group at 1 and 3 months post-transplantation ( P=0.002, P=0.043). The median positive rate of Granzyme B expression in CD3 +CD8 + T cells and CD3 +CD4 + T cells in the EBV+ group was significantly lower than that in the EBV- group at 1-month post-transplantation ( P=0.033, P=0.016). The median positive rate of Granzyme B expression in the CD3 -CD16 briCD56 neg cell subset in the EBV+ group was higher than that in the EBV- group at 2 months post-transplantation ( P=0.012). The median positive rate of Granzyme B expression in CD3 +CD4 + T cells in the EBV+ group remained significantly lower than that in the EBV- group at 2 months post-transplantation ( P=0.049). The median positive rate of perforin expression in the CD3 -CD16 briCD56 dim cell subset was significantly higher in the EBV+ group than in the EBV- group at 3 months post-transplantation ( P=0.003). The median positive rate of IFN-γ expression in CD3 +CD8 + T cells in the EBV+ group was significantly lower than that in the EBV- group at 3 months post-transplantation ( P=0.036) . Conclusion:Delayed NK cell and T lymphocyte reconstitution, high exhaustion marker expression, and weakened cytotoxic functions may be related to EBV reactivation after haploidentical HSCT.
10.Effects of breast milk intake ratio during hospitalization on antibiotic therapy duration in preterm infants less than 34 gestational weeks: a multicenter retrospective cohort study
Chengpeng GU ; Wenjuan CHEN ; Shuping HAN ; Yan GAO ; Rongping ZHU ; Jihua ZHANG ; Rongrong CHEN ; Yan XU ; Shanyu JIANG ; Yuhan ZHANG ; Xingxing LU ; Mei XUE ; Mingfu WU ; Zhaojun PAN ; Dongmei CHEN ; Xiaobo HAO ; Xinping WU ; Jun WAN ; Huaiyan WANG ; Songlin LIU ; Danni YE ; Xiaoqing CHEN ; Weiwei HOU ; Li YANG
Chinese Journal of Perinatal Medicine 2023;26(7):546-553
Objective:To investigate the effects of breast milk to total milk intake ratio during hospitalization on the duration of antibiotic therapy in preterm infants less than 34 weeks of gestation.Methods:Clinical data of preterm infants ( n=1 792) less than 34 gestational weeks were retrospectively collected in 16 hospitals of Jiangsu Province Neonatal-Perinatal Cooperation Network from January 1, 2019, to December 31, 2021. The days of therapy (DOT) were used to evaluate the duration of antibiotic administration. The median DOT was 15.0 d (7.0-27.0 d). The patients were divided into four groups based on the quartiles of DOT: Q 1 (DOT≤7.0 d), Q 2 (7.0 d

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