Objective:To construct and validate a predictive model for postoperative pulmonary complications (PPCs) in patients undergoing robot-assisted laparoscopic urological surgery.Methods:This retrospective study included the medical records of 932 patients who underwent robot-assisted laparoscopic urological surgery at the First Affiliated Hospital of Zhejiang University School of Medicine from January 2020 to February 2022. The patients were divided into a training group ( n=559) and a validation group ( n=373) at a 6∶4 ratio. Logistic regression analysis was used to determine the independent risk factors for PPCs, and a nomogram prediction model was constructed based on these factors. The performance of the model was evaluated using the receiver operating characteristic curve and calibration curve, and the clinical benefit was assessed using the clinical decision curve analysis. Results:The independent risk factors for PPCs included advanced age (>60 yr), smoking history, respiratory tract infection within 1 month, preoperative low SpO 2 (<96%), and prolonged length of postoperative hospital stay ( P<0.05), and the body mass index (18.5-<28.0 kg/m 2) was a protective factor. The nomogram prediction model developed based on the aforementioned 6 influencing factors had an area under the receiver operating characteristic curve of 0.81 (95% confidence interval 0.76-0.86) in training group and 0.80 (95% confidence interval 0.75-0.86) in validation group. The calibration curve indicated a good consistency between the predicted and actual occurrence curves, and the clinical decision curve analysis showed good accuracy and net benefit of the prediction model. Conclusions:The predictive model for PPCs is successfully constructed based on age, low body mass index, smoking history, history of respiratory tract infection within 1 month, preoperative low SpO 2 and prolonged length of postoperative hospital stay and has good predictive performance in patients undergoing robot-assisted laparoscopic urological surgery.

Polycystic ovary syndrome （PCOS） is a common gynecological endocrine and reproductive disorder，with the main clinical manifestations including ovulation failure，insulin resistance，hyperandrogenism，and obesity. Its occurrence and development are closely related to cellular regulatory mechanisms such as apoptosis，autophagy，oxidative stress，and inflammatory response. Autophagy，as a clearance mechanism that maintains cellular homeostasis，plays a crucial role in maintaining the growth，development，and maturation of oocytes. Exploring the mechanism of autophagy during the occurrence and development of diseases can help develop treatment methods for PCOS by regulating autophagy. Studies have shown that autophagy plays an important role in the pathogenesis of PCOS，and it can affect the occurrence and development of PCOS through multiple pathways，levels，and targets. Traditional Chinese medicine （TCM） regulates autophagy in ovarian granulosa cells or endometrium of patients with PCOS by targeting the expression of autophagy signaling pathways，regulatory factors，and non-coding single-stranded RNA molecules，thereby alleviating inflammation，regulating metabolism disorders，and balancing hormone levels in PCOS. Accordingly，TCM can ameliorate pathological conditions such as insulin resistance，hyperandrogenism，and ovulation failure in PCOS. This article summarizes the TCM formulas and extracts for the treatment of PCOS，as well as the main autophagy pathways and regulatory factors involved，aiming to provide reference and suggestions for the future treatment of PCOS with TCM by regulating autophagy.

Objective:To construct and validate a predictive model for postoperative pulmonary complications (PPCs) in patients undergoing robot-assisted laparoscopic urological surgery.Methods:This retrospective study included the medical records of 932 patients who underwent robot-assisted laparoscopic urological surgery at the First Affiliated Hospital of Zhejiang University School of Medicine from January 2020 to February 2022. The patients were divided into a training group ( n=559) and a validation group ( n=373) at a 6∶4 ratio. Logistic regression analysis was used to determine the independent risk factors for PPCs, and a nomogram prediction model was constructed based on these factors. The performance of the model was evaluated using the receiver operating characteristic curve and calibration curve, and the clinical benefit was assessed using the clinical decision curve analysis. Results:The independent risk factors for PPCs included advanced age (>60 yr), smoking history, respiratory tract infection within 1 month, preoperative low SpO 2 (<96%), and prolonged length of postoperative hospital stay ( P<0.05), and the body mass index (18.5-<28.0 kg/m 2) was a protective factor. The nomogram prediction model developed based on the aforementioned 6 influencing factors had an area under the receiver operating characteristic curve of 0.81 (95% confidence interval 0.76-0.86) in training group and 0.80 (95% confidence interval 0.75-0.86) in validation group. The calibration curve indicated a good consistency between the predicted and actual occurrence curves, and the clinical decision curve analysis showed good accuracy and net benefit of the prediction model. Conclusions:The predictive model for PPCs is successfully constructed based on age, low body mass index, smoking history, history of respiratory tract infection within 1 month, preoperative low SpO 2 and prolonged length of postoperative hospital stay and has good predictive performance in patients undergoing robot-assisted laparoscopic urological surgery.

Objective:To analyze the current status of internet-based patient education materials related to labor analgesia in China.Methods:Labor analgesia-related materials were retrieved and screened according to the search habits of Chinese search engine users. The coverage and accuracy of the content were evaluated by 3 anesthesiologists. The Chinese version of the Patient Education Materials Assessment Tool for Print Materials was used to subjectively assess comprehensibility and operability from a medical text perspective. The consistency of the evaluation results of the three anesthesiologists was analyzed using the intraclass correlation coefficient method. A machine learning method combined with ChatGPT-4.0 was employed to establish a Chinese readability classification model to objectively evaluate the readability difficulty of the included materials from a Chinese text perspective.Results:A total of 97 web pages were retrieved, with 21 valid materials included in the study. The coverage rate of contraindications for labor analgesia was only 62% (13/21), and the accuracy rate of materials exceeding 90% was 71% (15/21). Internet-based materials that were easy to understand accounted for 81% (17/21), while the constituent ratio of internet-based materials with instructional significance were only 5% (1/21). The intraclass correlation coefficient values of consistency evaluation for coverage rate, accuracy rate, and comprehensibility and operability were 0.975, 0.833, 0.758, and 0.773, respectively ( P<0.001). Internet-based materials suitable for compulsory education level were only 5% (1/21), while those suitable for high school and above education level accounted for 43% (9/21). Conclusions:There are numerous internet-based patient education materials related to labor analgesia in China, but the quality needs improvement. In the future, a collaborative model of " anesthesiology+ linguistics" should be developed to provide patients with more comprehensive, accurate, and pregnant-friendly patient education materials.

Congenital median cleft lip caused by all kinds of reasons is the most basic presentation of facial median cleft. Although a wide array of options is available, the technique employed will largely depend on the surgeon preference and experience, and lack of uniform standards. The basic surgical treatments of midline cleft lip and nose deformities include exposure of abnormal anatomy, repair soft tissue and skin, anatomic approximation of cartilaginous elements, orbicularis oris muscle repair and craniofacial osteotomy. However, there is still no common classification system to stratify the wide variations of midline cleft lip and nasal deformity, which is important to formulate specific surgical method for different types. This article summarized various classifications, recommended to use the Kolker’s classification by which the treatment options were summarized and proposed research prospects to provide ideas for further study.

Objective:To understand the relevant situation of people seeking tattoo removal in laser cosmetic clinics.Methods:A face-to-face questionnaire survey was conducted among respondents seeking tattoo removal who visited the Laser Cosmetic Clinic of the Provincial Hospital Affiliated to Shandong First Medical University from June 2021 to May 2022. The questionnaire survey content included 4 categories and a total of 30 questions: basic information of the tattoo respondents, tattoo-related situations, respondents’ cognition of tattoos, and tattoo removal needs. The questionnaire responses were statistically analyzed, and differences were analyzed according to the gender, age of the tattoo respondents, and educational level at the time of tattooing. Descriptive statistical analysis was conducted on the general information of the questionnaire; Mantel-Haenszel chi-square test or Pearson’s chi-squared test were used for the analysis of the difference in the composition ratio of each data.Results:A total of 150 questionnaires were distributed and 142 valid questionnaires were collected. There were 81 male and 61 female tattoo respondents, with an age of (21.8±4.9) years (13-41 years). The result of the survey showed that 52.8%(75/142) of the respondents were minors (<18 years old) at the time of tattooing, and 97.2%(138/142) were <24 years old at the time of tattooing; 67.6% (96/142) regretted the act of tattooing; 73.2%(104/142) of the respondents themselves asked for the removal of tattoos; who removed their tattoos for personal development (joining the army, working, studying) was 68.3%(97/142); only 23.2%(33/142) of the respondents understood the harms of tattoos; and 21.8%(31/142) of the respondents suffered from adverse reactions after getting tattoos. The percentage of respondents who hid their tattoos from their family members was 82.4%(117/142); the percentage of respondents whose family members approved of the tattoos was only 25.4%(36/142). Analysis of variance showed that there was no correlation between the education level of the respondents and their knowledge of the tattoo risks( P>0.05); the reasons for removing tattoos were correlated with the age and gender of the respondents at the time of consultation ( P<0.01); the size of tattoos was correlated with the gender of the respondents ( P<0.01) and the female respondents were more inclined to choose a small tattoo; the age of tattooing of the respondents was correlated with the level of education of the respondents when they had tattooed themselves ( P<0.01), the proportion of tattoos aged <18 years old was highest among respondents with junior high school education at the time of tattooing [76.2%(32/42)], and this proportion tended to decrease significantly as the education level at the time of tattooing increased. Conclusion:The respondents seeking tattoo removal in the laser cosmetic clinic are mainly teenagers. About half of the respondents were minors at the time of tattooing, and most of them were not aware of the tattoo risks. There is a certain correlation between the age of the respondents and their educational background at the time of tattooing. There are certain differences in the reasons for removing tattoos among respondents depending on gender and age. There is no correlation between the educational background of the respondents and their understanding of the tattoo risks.

Objective:To understand the relevant situation of people seeking tattoo removal in laser cosmetic clinics.Methods:A face-to-face questionnaire survey was conducted among respondents seeking tattoo removal who visited the Laser Cosmetic Clinic of the Provincial Hospital Affiliated to Shandong First Medical University from June 2021 to May 2022. The questionnaire survey content included 4 categories and a total of 30 questions: basic information of the tattoo respondents, tattoo-related situations, respondents’ cognition of tattoos, and tattoo removal needs. The questionnaire responses were statistically analyzed, and differences were analyzed according to the gender, age of the tattoo respondents, and educational level at the time of tattooing. Descriptive statistical analysis was conducted on the general information of the questionnaire; Mantel-Haenszel chi-square test or Pearson’s chi-squared test were used for the analysis of the difference in the composition ratio of each data.Results:A total of 150 questionnaires were distributed and 142 valid questionnaires were collected. There were 81 male and 61 female tattoo respondents, with an age of (21.8±4.9) years (13-41 years). The result of the survey showed that 52.8%(75/142) of the respondents were minors (<18 years old) at the time of tattooing, and 97.2%(138/142) were <24 years old at the time of tattooing; 67.6% (96/142) regretted the act of tattooing; 73.2%(104/142) of the respondents themselves asked for the removal of tattoos; who removed their tattoos for personal development (joining the army, working, studying) was 68.3%(97/142); only 23.2%(33/142) of the respondents understood the harms of tattoos; and 21.8%(31/142) of the respondents suffered from adverse reactions after getting tattoos. The percentage of respondents who hid their tattoos from their family members was 82.4%(117/142); the percentage of respondents whose family members approved of the tattoos was only 25.4%(36/142). Analysis of variance showed that there was no correlation between the education level of the respondents and their knowledge of the tattoo risks( P>0.05); the reasons for removing tattoos were correlated with the age and gender of the respondents at the time of consultation ( P<0.01); the size of tattoos was correlated with the gender of the respondents ( P<0.01) and the female respondents were more inclined to choose a small tattoo; the age of tattooing of the respondents was correlated with the level of education of the respondents when they had tattooed themselves ( P<0.01), the proportion of tattoos aged <18 years old was highest among respondents with junior high school education at the time of tattooing [76.2%(32/42)], and this proportion tended to decrease significantly as the education level at the time of tattooing increased. Conclusion:The respondents seeking tattoo removal in the laser cosmetic clinic are mainly teenagers. About half of the respondents were minors at the time of tattooing, and most of them were not aware of the tattoo risks. There is a certain correlation between the age of the respondents and their educational background at the time of tattooing. There are certain differences in the reasons for removing tattoos among respondents depending on gender and age. There is no correlation between the educational background of the respondents and their understanding of the tattoo risks.

Objective:To explore the therapeutic efficacy and factors influencing the sequential combination of nucleos(t)ide analogues (NAs) with pegylated interferon alpha (Peg-IFN-α) in the treatment of patients with chronic hepatitis B (CHB).Methods:144 CHB cases with NAs treatment for more than 1 year, HBV DNA < 20 IU/ml, hepatitis B surface antigen (HBsAg) quantification < 3 000 IU/ml, treated with a sequential combination of Peg-IFN-α treatment for 48 to 96 weeks, and followed up were selected from the Fifth Medical Center of the PLA General Hospital between May 2018 and May 2020. Intention-to-treat analysis was used to measure the HBsAg clearance rate at 96 weeks. The Kaplan-Meier method was used to compute the cumulative HBsAg clearance rate at 96 weeks. Univariate and multivariate logistic regression were used to analyze the factors influencing HBsAg clearance at 48 weeks of sequential combination therapy. Univariate and multifactorial COX proportional hazard models were used to analyze the factors influencing HBsAg clearance following 96 weeks of prolonged PEG-IFN-α treatment. The receiver operating characteristic curve was used to assess the predictive value of factors influencing HBsAg clearance. A Mann-Whitney U test was used to compare the measurement data between groups. The count data was compared using the χ2 test between groups. Results:41 (28.47%) cases achieved HBsAg clearance at 48 weeks of sequential combination therapy. The HBsAg clearance rate at 96 weeks was 40.28% (58/144) by intention-to-treat analysis. The Kaplan-Meier method computed that the cumulative HBsAg clearance rate at 96 weeks was 68.90%. Multivariate logistic regression analysis showed that HBsAg quantification at baseline ( OR = 0.090, 95% CI: 0.034-0.240, P < 0.001) and a 24-week drop in HBsAg level ( OR = 7.788, 95% CI: 3.408-17.798, P < 0.001) were independent predictors of HBsAg clearance in CHB patients treated sequentially in combination with NAs and Peg-IFN-α for 48 weeks. Receiver operating characteristic curve analysis showed that the baseline HBsAg quantification [area under the receiver operating characteristic curve (AUC), 0.911, 95% CI: 0.852-0.952)] and 24-week drop in HBsAg level (AUC = 0.881, 95% CI: 0.814-0.930) had equally good predictive value for 48-week HBsAg clearance, but there was no statistically significant difference between the two ( Z = 0.638, P = 0.523). The value of the combination of baseline HBsAg quantification and 24-week drop in HBsAg level (AUC = 0.981, 95% CI: 0.941-0.997) was superior to that of single baseline HBsAg quantification ( Z = 3.017, P = 0.003) and 24-week drop in HBsAg level ( Z = 3.214, P = 0.001) in predicting HBsAg clearance rate at 48 weeks. Multivariate COX proportional hazards model analysis showed that HBsAg quantification at 48 weeks ( HR = 0.364, 95% CI: 0.176-0.752, P = 0.006) was an independent predictor of HBsAg clearance with a prolonged course to 96 weeks of Peg-IFN-α treatment. Conclusion:The HBsAg clearance rate can be accurately predicted with baseline HBsAg quantification combined with a 24-week drop in HBsAg level in patients with CHB who are treated with a sequential combination of NAs and Peg-IFN-α therapy for 48 weeks. Prolonging the course of Peg-IFN-α treatment can enhance the HBsAg clearance rate's capability. An independent predictor of HBsAg clearance is HBsAg quantification at 48 weeks of sequential combination therapy with a prolonged course of 96 weeks of Peg-IFN-α treatment.

Objective:To explore the influence of pH value on tube formation of human dermal microvascular endothelial cells (HDMECs) and study its molecular mechanism, so as to provide theoretical basis for the study of promoting angiogenesis in the process of wound healing.Methods:The experimental study methods were applied. HDMECs of 4 or 5 passages in the logarithmic growth phase were collected for experiments. Culture mediums with pH values of 6.4, 6.6, 6.8, 7.0, 7.2, 7.4, 7.6, and 7.8 were prepared, and the cells were adaptively cultured (the same culture method below) for 24 h before further experiments being carried out. After another 36 h of culture, the relative fluorescence value of cytoplasmic pH value was measured by flow cytometry, and the correlation analysis between the relative fluorescence value of cytoplasmic pH value and the medium pH value was carried out. After another 1.5, 2.5, 3.5, 4.5, and 5.5 days of culture, the cell proliferation activity was detected with cell counting kit 8. Oris TM cell migration detection kit was used to detect the remaining area of cell migration at 0 (immediately), 24, and 48 h after removing the cell seeding stopper. Three-dimensional stromal gel cell tube formation experiment was carried out to detect the lumen diameter of tube formed by cells after another 48 h of culture. The protein expressions of phosphorylation sites 473 and 308 of protein kinase B (Akt) were detected by Western blotting after another 48 h of culture. The sample number was 3. Data were statistically analyzed with Pearson correlation analysis, one-way analysis of variance, analysis of variance for factorial design, analysis of variance for repeated measurement, and Bonferroni correction. Results:After another 36 h of culture, the relative fluorescence values of cytoplasmic pH value of cells cultured in pH 6.8-7.8 mediums were significantly higher than the level in pH 6.4 medium ( P<0.05); compared with those in pH 6.6-7.0 mediums, the relative fluorescence values of cytoplasmic pH value of cells cultured in pH 7.4-7.8 mediums were significantly increased ( P<0.05), and the relative fluorescence value of cytoplasmic pH value of cells cultured in pH 6.6 medium was significantly lower than that in pH 7.0 or 7.2 mediun (with P values all <0.05); the relative fluorescence values of cytoplasmic pH value of cells cultured in pH 7.6 and 7.8 mediums were significantly higher than those in pH 7.2 and 7.4 mediums ( P<0.05). The relative fluorescence value of cytoplasmic pH value was significantly positively correlated with the medium pH value ( r=0.99, P<0.05). The proliferation activity was similar among cells cultured in 8 mediums of different pH values for another 1.5 days ( P>0.05). After another 2.5 days of culture, the proliferation activity of cells cultured in pH 6.4-6.8 mediums was significantly decreased compared with that in pH 7.6 medium ( P<0.05). After another 3.5 days of culture, the proliferation activity of cells cultured in pH 7.0-7.8 mediums was significantly higher than that in pH 6.4-6.8 mediums ( P<0.05); compared with that in pH 7.6 medium, the proliferation activity of cells cultured in pH 7.0-7.4 and 7.8 mediums was significantly decreased ( P<0.05). After another 4.5 or 5.5 days of culture, the proliferation activity of cells cultured in pH 6.8-7.8 mediums was significantly higher than that in pH 6.4 medium ( P<0.05); compared with that in pH 6.6 and 6.8 mediums, the proliferation activity of cells cultured in pH 7.0-7.8 mediums was significantly increased ( P<0.05). After another 4.5 days of culture, the proliferation activity of cells cultured in pH 7.6 medium was significantly higher than that in pH 7.0 medium ( P<0.05). After another 5.5 days of culture, the proliferation activity of cells cultured in pH 7.2-7.6 mediums was significantly increased compared with that in pH 7.0 medium ( P<0.05); the proliferation activity of cells cultured in pH 7.2 and 7.4 mediums was significantly lower than that in pH 7.6 medium (with P values all <0.05) but significantly higher than that in pH 7.6 medium (with P values all <0.05). Immediately after removing the cell seeding stopper, the remaining migration areas were similar among cells cultured in 8 mediums of different pH values ( P>0.05). At 24 h after removing the cell seeding stopper, the remaining migration areas of cells cultured in pH 6.6-7.8 mediums were significantly smaller than the area in pH 6.4 medium ( P<0.05); compared with those in pH 6.6 and 6.8 mediums, the remaining migration areas of cells cultured in pH 7.0 to 7.6 mediums were significantly reduced ( P<0.05). At 48 h after removing the cell seeding stopper, compared with those in pH 6.4 and 6.6 mediums, the remaining migration areas of cells cultured in pH 7.0-7.8 mediums were significantly reduced ( P<0.05); the remaining migration areas of cells cultured in pH 7.2 and 7.4 mediums were significantly smaller than those in pH 6.8, 7.0, and 7.8 mediums ( P<0.05) but significantly larger than the area in pH 7.6 medium ( P<0.05); the remaining migration area of cells cultured in pH 7.6 medium was significantly smaller than that in pH 6.8 or 7.8 medium (with P values all <0.05). After another 48 h of culture, the lumen diameters of tubes formed by cells cultured in pH 7.0, 7.2, 7.4, 7.6, and 7.8 mediums were (5.0±0.5), (7.6±0.9), (8.5±0.7), (11.0±0.8), and (5.3±0.8) μm, respectively, which were significantly longer than (2.8±0.8) μm in pH 6.4 medium ( P<0.05); the lumen diameters of tubes formed by cells cultured in pH 6.6 ((4.2±0.3) μm), 6.8 ((4.5±0.6) μm), 7.0, and 7.8 mediums were significantly shorter than the diameter in pH 7.6 medium ( P<0.05). After another 48 h of culture, compared with those in pH 6.4 and 6.6 mediums, the protein expressions of Akt phosphorylation sites 473 and 308 of cells cultured in pH 6.8 to 7.8 mediums were significantly increased ( P<0.05). Moreover, the protein expression of Akt phosphorylation site 308 of cells cultured in pH 6.6 medium was significantly higher than that in pH 6.4 medium ( P<0.05); compared with the expression in pH 6.8 medium, the protein expressions of Akt phosphorylation site 473 of cells cultured in pH 7.0 and 7.4-7.8 mediums were significantly increased ( P<0.05); compared with the expression in pH 7.6 medium, the protein expressions of Akt phosphorylation site 473 of cells cultured in pH 7.0-7.4 and 7.8 mediums were significantly decreased ( P<0.05); compared with the expression in pH 7.8 medium, the protein expressions of Akt phosphorylation site 308 of cells cultured in pH 7.0 to 7.6 mediums were significantly increased ( P<0.05). Conclusions:pH value can regulate the lumen diameter of HDMEC-formed capillaries, which is closely related to the activation of Akt. 7.2-7.6 is the appropriate pH value for constructing tissue engineered capillaries.

Objective:To understand the relevant situation of people seeking tattoo removal in laser cosmetic clinics.Methods:A face-to-face questionnaire survey was conducted among respondents seeking tattoo removal who visited the Laser Cosmetic Clinic of the Provincial Hospital affiliated to Shandong First Medical University from June 2021 to May 2022. The survey content mainly included: basic information of the tattoo respondents, tattoo-related situations, respondents’ cognition of tattoos, and 30 questions on tattoo removal needs. The questionnaire responses were statistically analyzed, and differences were analyzed according to the gender, age of the tattoo respondents, and educational level at the time of tattooing. Descriptive statistical analysis was conducted on the general information of the questionnaire; Mantel-Haenszel chi-square test or Pearson’ s chi-squared test were used for the analysis of the difference in the composition ratio of each data.Results:A total of 150 questionnaires were distributed and 142 valid questionnaires were collected. There were 81 male and 61 female tattoo respondents, and (21.8±4.9) years (13- 41 years) . The result of the survey showed that 52.8% (75/142) of the respondents were minors (<18 years old) at the time of tattooing, and 97.2% (138/142) were <24 years old at the time of tattooing; 67.6% (96/142) regretted the act of tattooing; 73.2% (104/142) of the respondents themselves asked for the removal of tattoos; who removed their tattoos for personal development (joining the army, working, studying) was 68.3% (97/142) ; only 23.2% (33/142) of the respondents understood the harms of tattoos; and 21.8% (31/142) of the respondents suffered from adverse reactions after getting tattoos. The percentage of respondents who hid their tattoos from their family members was 82.4% (117/142) ; the percentage of respondents whose family members approved of the tattoos was only 25.4% (36/142) . Analysis of variance showed that there was no correlation between the education level of the respondents and their knowledge of the dangers of tattooing ( P>0.05) ; the reasons for removing tattoos were correlated with the age and gender of the respondents at the time of consultation ( P<0.01) ; the size of tattoos was correlated with the gender of the respondents ( P<0.01) and the female respondents were more inclined to choose a small tattoo; the age of tattooing of the respondents was correlated with the level of education of the respondents when they had tattooed themselves ( P<0.01) , the proportion of tattoos aged <18 years old was highest among respondents with junior high school education at the time of tattooing [76.2% (32/42) ] , and this proportion tended to decrease significantly as the education level at the time of tattooing increased. Conclusions:The respondents seeking tattoo removal in the laser cosmetic clinic are mainly teenagers. About half of the respondents were minors at the time of tattooing, and most of them were not aware of the dangers of tattoos. There is a certain correlation between the age of the respondents and their educational background at the time of tattooing. There are certain differences in the reasons for removing tattoos among respondents depending on gender and age. There is no correlation between the educational background of the respondents and their understanding of the dangers of tattoos.