BACKGROUND:The structure,physical and chemical properties(such as rheological properties)and biological activity of hyaluronic acid with different molecular weights are quite different.When the degradation degree of non-cross-linked hyaluronic acid is too large and the high-molecular-weight hyaluronic acid is degraded to low-molecular-weight hyaluronic acid,the properties and biological functions of the product will also change,which will affect the use of the product. OBJECTIVE:To review the mechanism of molecular weight degradation of non-cross-linked hyaluronic acid and the impacts of molecular weight degradation on the structure,rheological properties,biological activity and applications of non-cross-linked hyaluronic acid. METHODS:The first author searched the articles related to the molecular weight of hyaluronic acid collected in PubMed,CNKI database and other databases.The high-quality articles with high correlation were screened according to the inclusion and exclusion criteria.The search time was from January 2017 to December 2022.The Chinese and English search terms were"hyaluronic acid,non-cross-linked hyaluronic acid,molecular weight,degradation,structure,rheological properties,biologic activity".Finally,47 articles were included for review and analysis. RESULTS AND CONCLUSION:(1)The molecular weight of non-cross-linked hyaluronic acid is mainly degraded by specific enzymatic hydrolysis and non-specific free radical degradation.(2)The molecular weight degradation of non-cross-linked hyaluronic acid will change its structure and rheological properties,resulting in the untie of polymer network structure,the decrease of rheological properties such as viscosity and viscoelasticity,and the decrease of mechanical properties,which will eventually affect the practical application effect of the product.(3)The biological activity of non-cross-linked hyaluronic acid is molecular weight dependent,and the biological activity of different molecular weight hyaluronic acid is different.Even the same receptor combined with high-molecular-weight hyaluronic acid and low-molecular-weight hyaluronic acid will express completely opposite biological effects.(4)The degradation of molecular weights of non-cross-linked hyaluronic acid will reduce the safety and efficacy of the products,affect their service life and application performance,and ultimately influence the clinical application results.(5)Non-cross-linked hyaluronic acid has great potential as a biodegradable biomaterial in wound healing,tissue engineering,aesthetic medicine and other fields,and further research and understanding of the correlation between molecular weight degradation of non-cross-linked hyaluronic acid and bioactivity is a prerequisite for better development of wound dressings,drug delivery systems and tissue-engineered scaffolds.(6)However,there are currently few studies on the molecular weight degradation of non-cross-linked hyaluronic acid,and it is unclear how to effectively avoid the potential risks associated with the molecular weight degradation of non-cross-linked hyaluronic acid in clinical applications.(7)Therefore,a series of potential risks associated with the molecular weight degradation of non-cross-linked hyaluronic acid during its application,including the effects on its structure,properties and biological activity,and the resulting changes on the body,is one of the future directions that need to be closely investigated.

Objective:To observe the changes of pelvic floor structure and function in female vaginal laxity after CO 2 fractional laser transvaginal treatment. Methods:This study reviewed the improvement of pelvic floor structure and function after CO 2 fractional laser transvaginal treatment in 28 female patients [aged 26-59 (37.5±8.3) years] with vaginal laxity syndrome seen at the Department of Dermatology, the First Affiliated Hospital of Air Force Medical University from March 2020 to November 2021. A total of 28 female patients with vaginal laxity syndrome underwent intravaginal treatment by CO 2 fractional laser instrument once/month for 3 times. The clinical efficacy and safety were evaluated according to the pre- and post-treatment transverse vaginal diameter, FSFI score of female sexual function, VHIS score of vaginal environment, vaginal tactile imaging system (VTI), pelvic ultrasound and MRI, tissue biopsy, patient satisfaction, pain score, and postoperative adverse effects. Results:Twenty-one of the twenty-eight female patients with vaginal laxity syndrome showed significant improvement in symptoms related to vaginal laxity syndrome after intravaginal treatment with CO 2 fractional laser therapy. All patients showed improvement in all indexes before and 1 month after treatments the mean vaginal transverse diameter decreased from (3.00±0.39) fingers to (2.71±0.40) fingers ( P<0.05), VHIS increased from (17.12±3.97) to (21.69±3.61) ( P<0.05), FSFI score improved from (23.11±3.70) to (27.43±5.33) ( P<0.05), and VTI examination showed that vaginal muscle strength and elasticity were improved to different degrees, and there was a statistical difference compared with that before treatment (total contractility of the anterior vaginal wall: t=26.23, P<0.001; total contractility of posterior vaginal wall: t=39.02, P<0.001; the mean contractility of the anterior vaginal wall: t=17.92, P<0.001; the mean contractility of the posterior vaginal wall: t=22.57, P<0.001). At the same time, questionnaire score of international consultation on incontinent questionnaire short form (ICI-Q-SF scale) of 13 patients with combined mild to moderate stress urinary incontinence showed a statistically significant decrease compared with those before treatment (8.97±2.99 before treatment and (7.18±1.79) one month after treatment; t=2.792, P<0.01). Pelvic ultrasound and magnetic resonance examination indicated a tightening of the vaginal wall structure, and pelvic ultrasound observed a significant decrease in bladder neck mobility and a significant decrease in vesicourethral rotation angle. Vaginal tissue biopsy indicated an increase in the thickness of the vaginal mucosa and an increase in the number and more regular arrangement of collagen fibers after treatment. All patients had high treatment satisfaction and there were no adverse effects such as infection and bleeding during the treatment. Conclusions:Transvaginal CO 2 fractional laser treatment can improve the pelvic floor structure and function around the vagina, treat female vaginal laxity syndrome, stress urinary incontinence and female sexual dysfunction, with significant clinical efficacy and good safety.

【Objective】 To evaluate the efficacy and safety of intravaginal fractional superpulse CO2 laser in the treatment of mild to moderate female stress urinary incontinence (SUI), so as to provide reference for the treatment options for female SUI. 【Methods】 A total of 41 female mild-to-moderate SUI patients confirmed at the Department of Urology, The First Affiliated Hospital, Air Force Medical University, during Aug.2019 and Nov.2020 were involved.All patients received 3 intravaginal fractional superpulse CO2 laser treatments (1/month).The improvement of urinary incontinence symptoms after treatment was evaluated with International Consultation on Incontinent Questionnaire Short Form (ICI-Q-SF).The motion of bladder neck and rotation angle of bladder and urethra were measured with pelvic ultrasound before and after treatment.The therapeutic effects, pain and patients’ satisfaction were evaluated, and adverse reactions such as bleeding, infection and scar were observed. 【Results】 Three months after treatment, urinary incontinence symptoms improved to varying degrees, the ICI-Q-SF score decreased, the motion of bladder neck [ (28.70±3.11) mm vs.(19.10±4.54) mm] and the vesicourethral rotation angle [(52.78°±15.79°) vs.(41.56°±13.24°)] significantly decreased (P<0.05).The total effective rate was 100.0%.No patients complained severe pain during treatment.All patients were satisfied with the treatment.No adverse reactions such as bleeding, infection or scar occurred. 【Conclusion】 Intravaginal fractional superpulse CO2 laser is effective and safe in the treatment of mild to moderate female SUI, but the long-term efficacy still needs further observation.

Objective:To investigate the current comorbidity status among hypertension, diabetes, and dyslipidemia in residents aged 35-75 years in Tianjin and to explore the main influencing factors to provide a scientific basis for the prevention and treatment of chronic disease comorbidity.Methods:From June 2019 to November 2023, 10 districts (Hedong, Hexi, Dongli, Beichen, Nankai, Xiqing, Wuqing, Baodi, Jizhou, and Binhai New District) in Tianjin were selected as the project sites. The community and natural village was used as the primary sampling unit, and each project site selected the screening sites by cluster random sampling method. Residents aged 35-75 who lived in the screening sites for 6 months and above were surveyed by questionnaire, physical examination, and biochemical tests. The chi-square test, analysis of variance, and multivariate unconditional logistic regression analysis were used for statistical analysis. Age-standardized prevalence was based on the data of the sixth national census.Results:A total of 146 832 participants were included in this study, including 61 994 males (42.22%) and 84 838 females (57.78%), with an age of (56.83±8.84) years. The number of people with only one disease was 55 485 (37.79%), the number of people with two diseases was 36 942 (25.16%), and the number of people with three diseases was 9 683 (6.59%). The prevalence of hypertension combined with dyslipidemia was the highest (17.23%), and the standardized prevalence were 14.44%. The prevalence rates of three diseases and hypertension combined with diabetes was 6.59% and 4.98%, respectively, and the standardized prevalence was 5.42% and 4.11%, respectively. The prevalence of diabetes combined with dyslipidemia was 2.95%, and the standardized prevalence was 2.45%. Multivariate unconditional logistic regression analysis showed that advanced age (65- 75 years old: OR=2.69, 95% CI: 2.28-3.18), overweight/obesity (overweight: OR=2.21, 95% CI: 2.02-2.41; obesity: OR=4.50, 95% CI: 4.03-5.02), daily smoking ( OR=1.96, 95% CI: 1.72-2.24), regular and heavy drinking ( OR=1.63, 95% CI: 1.18-2.27), family history of hypertension/diabetes/hyperlipidemia (family history of hypertension: OR=81.17, 95% CI: 74.68-88.22; family history of diabetes: OR=15.26, 95% CI: 13.71-16.99; family history of hyperlipidemia: OR=7.13, 95% CI: 5.92-8.59), tea drinking (occasional tea drinking group: OR=1.74, 95% CI: 1.52-2.00; frequent tea drinking group: OR=2.23, 95% CI: 1.92-2.59) were risk factors for the comorbidity of hypertension, diabetes and dyslipidemia (all P<0.05), while higher education level was a protective factor (senior high school/technical secondary school: OR=0.79, 95% CI: 0.72-0.86; college/bachelor's degree and above: OR=0.60, 95% CI: 0.53-0.68, all P<0.001). Conclusions:The comorbidity rate of hypertension, diabetes, and dyslipidemia is high in residents aged 35-75 years in Tianjin. It is necessary to strengthen the co-management of blood pressure, blood glucose, and blood lipid in key populations with old age, overweight/obesity, junior high school education or below, daily smoking, daily drinking, occasional or frequent tea drinking, and family history of hypertension/diabetes/dyslipidemia, and promote a healthy lifestyle.

Objective:To understand the interaction effect of general obesity, central obesity, and dyslipidemia on the risk of hypertension to provide scientific evidence for the early prevention and control of hypertension.Methods:From 2019 to 2023, 10 of the 16 districts in Tianjin were selected as project sites. A community and a natural village were selected as monitoring sites in each project site using a multi-stage cluster random sampling method. A questionnaire, physical, and biochemical examination were conducted on permanent residents aged 35-75 who had lived in the surveillance sites for more than half a year. The chi-square test univariate and multivariate logistic regression were used for statistical analysis. The multiplicative and additive models were used to calculate the interaction between general obesity and dyslipidemia, as well as central obesity and dyslipidemia, respectively.Results:A total of 177 160 subjects were included in the study, with an age of (56.44±8.62) years old. There were 29 535 (16.67%) patients with general obesity, 67 338 (38.01%) patients with central obesity, 64 906 (36.64%) patients with dyslipidemia, and 90 266 (50.95%) patients with hypertension. Multiplication interaction analysis results showed that, after adjusting for gender, age, culture level, marriage status, drinking, smoking, and diabetes, the multiplicative interactions between general obesity and dyslipidemia, and central obesity and dyslipidemia on hypertension were statistically significant (all P<0.001), and the adjusted OR and 95% CI were 2.57 (2.47-2.68) and 2.14 (2.08-2.20), respectively. The results of the additive interaction analysis demonstrated that after adjusting for relevant variables, the relative excess risk of interaction ( RERI), the attributable proportion of interaction ( API), and the synergy index ( SI) of the interaction between generalized obesity and dyslipidemia were 0.48 (95% CI: 0.33-0.63), 0.15 (95% CI: 0.11-0.19), and 1.27 (95% CI: 1.18-1.36), respectively; the RERI, API, and SI of the interaction between central obesity and dyslipidemia were 0.37 (95% CI: 0.28-0.46), 0.13 (95% CI: 0.10-0.16), and 1.25 (95% CI: 1.18-1.32), respectively. Conclusions:There might be multiplicative and additive interactions between general obesity, central obesity, and dyslipidemia on the risk of hypertension. Simultaneous control of BMI, waist circumference, and blood lipid levels may effectively reduce the risk of hypertension.

Objective:To investigate the effects of Shenghui Yizhi Decoction on learning and memory ability of SAMP8 mice; To explore its mechanism.Methods:Totally 24 male SAMP8 mice were randomly divided into model group, donepezil hydrochloride group (1 mg/kg) and Shenghui Yizhi Decoction group (15.6 g/kg), with 8 mice in each group, and eight anti rapid aging mice (SAMR1) of the same age and strain were set as the control group. The mice in each group were given corresponding medication or the same volume of distilled water for 90 days. After administration, Morris water maze was used to detect the learning and memory ability and space exploration ability of mice. Immunohistochemistry was used to detect expression of β Amyloid protein 1-42 (Aβ 1-42) in hippocampal. ELISA was used to detect the levels of interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α). Real time PCR was used to detect expressions of NOD-like receptor thermal protein domain associated protein 3 (NLRP3), cysteine protease-1 (Caspase-1), and IL-1β mRNA. Western Blot was used to detect expression of NLRP3, Caspase-1and IL-1β protein. Results:Compared with model group, the spatial exploration ability and memory ability of mice in Shenghui Yizhi Decoction group and donepezil hydrochloride group were improved ( P<0.05, P<0.01), the expression of Aβ 1-42 in hippocampus decreased ( P<0.05, P<0.01), the contents of IL-1β, IL-6 and TNF-α decreased ( P<0.05, P<0.01), and the mRNA and protein expressions of NLRP3, Caspase-1 and IL-1β decreased ( P<0.05, P<0.01). Conclusion:Shenghui Yizhi Decoction can effectively improve the learning and memory ability of SAMP8 mice, and its mechanism may be related to inhibiting the activation of inflammasome and neuroinflammatory response by regulating the NLRP3/ Caspase-1/ IL-1β signaling pathway.

Objective:To assess the efficacy and safety of skin care products containing mandelic acid and niacinamide in the management of mild to moderate acne.Methods:A total of 50 patients with mild to moderate acne were prospectively enrolled at Xijing Hospital, Air Force Military Medical University, from June to October 2020. Participants were randomly assigned into an observation group and a control group using a random number table method, with each group comprising 25 individuals. The observation group consisted of 3 males and 22 females, with a mean age of (22.5±3.2) years; the control group also included 3 males and 22 females, with a mean age of (22.9±2.8) years. The control group received conventional acne treatment without any additional skin care interventions apart from daily facial cleaning; conversely, the observation group was treated with skin care products containing mandelic acid and niacinamide alongside standard treatment protocols. At weeks 2, 4, and 8 post-treatment, objective assessments utilizing skin property system and VISIA complexion analysis system were conducted to evaluate changes in lesion count as well as recovery of skin barrier function between both groups; additionally, patients completed adverse reaction record forms.Results:No significant differences were observed regarding gender distribution, age demographics, disease duration or severity between the two groups ( P>0.05). After 8 weeks of treatment, the rates of effective improvement for skin lesions and acne were observed to be 84.0% (21/25) in the observation group compared to 56.0% (14/25) in the control group for lesion improvement, and 84.0% (21/25) versus 44.0% (11/25) for acne improvement, respectively. When compared to the control group, the observation group demonstrated significantly higher rates of effective improvement in both skin lesions and acne ( P<0.001).VISIA analysis revealed that pore size scores as well as violet scores decreased significantly after eight weeks in comparison to controls ( P=0.035; P=0.027). CK results indicated reduced transepidermal water loss along with diminished sebum levels within the observation cohort relative to controls ( P=0.009; P=0.042). Skin erythema along with symptoms such as dryness or burning sensations occurred among five patients (three from the observation cohort while two belonged to controls) with no serious adverse reactions reported across either study arm. Conclusions:Skin care products incorporating mandelic acid and niacinamide can serve effectively as adjunctive treatments for mild-to-moderate acne with enhancing clinical outcomes accompanied by minimal adverse effects.

Objective To construct the etoposide (VP-16)combined with cisplatin (DDP) chemotherapy scheme (EP chemotherapy scheme)resistant small cell lung cancer (SCLC)cell line H446/EP and to identify the drug resistance characteristics and explore the mechanism.Methods NCI-H446 cells were treated with increasing concentrations of VP-16 and DDP to construct an H446/EP cell line.H446/EP and NCI-H446 cells were used as the research objects.The cell viability was detected by MTT assay,and the resistance index (RI)of H446/EP cells was calculated.Cell cloning assay and Incucyte cell proliferation (label-free)assay were used to detect cell proliferation ability.Transcriptome sequencing was performed to analyze the enrichment of differentially expressed genes (DEGs)in the 2 cell lines.Western blotting was applied to detect the protein expression levels of drug resistance,DNA damage repair (DDR),and autophagy markers.Results MTT assay showed that the resistance index (RI)of H446/EP cells to VP-16,DDP,and DOX were 6.14,3.43,and 1.96,respectively.The results of cell cloning assay and Incucyte cell proliferation assay indicated that the proliferation ability was significantly higher in the H446/EP cells than the NCI-H446 cells (P<0.01).Transcriptome sequencing and pathway enrichment analysis displayed that the DEGs between H446/EP and NCI-H446 cells were enriched in tumor chemoresistance,DDR,and autophagy pathways.Western blot results showed the expression levels of MRP1,BCRP,RAD51,γ-H2AX,and LC3-Ⅱ/LC3-Ⅰ were significantly increased,and that of p62 was obviously decreased in the H446/EP cells when compared with the NCI-H446 cells (P<0.05).Conclusion An EP chemotherapy-resistant H446/EP cell line is successfully constructed.Stronger proliferation ability,increased expression of efflux transporters,and enhanced DDR and autophagy may be the mechanisms of the resistance of SCLC to EP chemotherapy scheme.

Objective:To explore the effects of life events, family environment and coping style on self-injury behavior in adolescents with first-episode depression.Methods:From July 2019 to December 2022, a total of 110 adolescent patients with first-episode depression were selected in the Psychiatry Department of the First Affiliated Hospital of Zhengzhou University. According to whether the patients had self-injury behavior, the patients were divided into group without self-injury( n=54)and group with self-injury( n=56).Patients in the two groups were evaluated by a general clinical data questionnaire, adolescent self-rating life events checklist (ASLEC), family environment scale-Chinese version(FES-CV), simplified coping style questionnaire (SCSQ), 24 items Hamilton depression scale (HAMD-24), Hamilton anxiety scale (HAMA) and 90 symptom checklist-90 (SCL-90). Statistical analysis including t-test, χ2 test and binary Logistic regression analysis were performed on the enrolled data by SPSS 25.0 statistical software. Results:Among 110 patients, there were 56 patients(50.9%) exhibited self-injury behavior.The scores of ASLEC(51.04±5.99, 48.02±6.86), intimacy(3.70±1.85, 4.59±1.60), emotional expression(3.84±1.80, 4.69±1.96), positive coping styles(15.84±5.85, 18.22±4.84), negative coping styles(12.50±3.23, 11.06±3.64), and HAMA(20.63±2.86, 19.48±2.55) showed statistically significant differences between the group with and without self-injury ( t=-2.46, 2.72, 2.36, 2.32, -2.20, -2.21, all P<0.05). Binary Logistic regression analysis showed that life events ( B=0.079, OR=1.083, 95% CI=1.008-1.163, P=0.030), negative coping style ( B=0.173, OR=1.188, 95% CI=1.033-1.367, P=0.016), HAMA ( B=0.225, OR=1.252, 95% CI=1.057-1.482, P=0.009) were risk factors for self-injury, while intimacy ( B=-0.264, OR=0.768, 95% CI=0.593-0.995, P=0.046) and positive coping styles ( B=-0.092, OR=0.912, 95% CI=0.834-0.997, P=0.044) were protective factors for self-injury. Conclusion:The self-injury behavior of adolescents with first-episode depression may be related to negative life events, early adverse family environment and coping style.

Objective:To explore the effects of depressive symptoms on sleep quality in adolescents with depressive disorder, and the mediating roles of cognitive fusion and sleep belief.Methods:A sample of 210 adolescents with first episode depressive disorder aged 12-18 years were recruited to complete 17-item Hamilton depression scale (HAMD-17), Pittsburgh sleep quality index (PSQI), cognitive fusion questionnaire (CFQ), and dysfunctional beliefs and attitudes about sleep scale (DBAS-16) from November 2021 to July 2022. SPSS 26.0 software was used to perform descriptive analysis and correlation analysis. The mediating effect was tested by Bootstrap analysis using PROCESS V 3.4 Macro program.Results:The incidence of low sleep quality in adolescents with depressive disorder was 69.0%(145/210). HAMD-17 score was (22.4±7.9), PSQI score was (9.7±3.7), CFQ score was (51.6±7.8), DBAS-16 score was (43.5±8.4).PSQI was positively correlated with the scores of HAMD-17 and CFQ( r=0.613, 0.463, both P<0.001).HAMD-17 was positively correlated with CFQ score ( r=0.488, P<0.001).DBAS-16 was negatively correlated with scores of PSQI, HAMD-17 and CFQ( r=-0.326, -0.284, -0.354, all P<0.001). The direct effect of depression on sleep quality was 0.230(95% CI=0.169-0.293). The indirect effect of depression on sleep quality through two pathways, the separate mediating effect value of cognitive fusion was 0.041 (95% CI=0.011-0.074), and the chain mediating effect value of cognitive fusion and sleep beliefs was 0.008(95% CI=0.001-0.020). Conclusion:Depressive symptoms can directly affect sleep quality of depressive disorder adolescents and indirectly through cognitive fusion and sleep beliefs.