【Objective】 To investigate the electronic screen exposure of preschool children in Longhua District of Shenzhen, and to analyze the influencing factors. 【Methods】 A total of 25 266 children in kindergarten in Longhua District of Shenzhen were selected as study subjects. A self-designed questionnaire (completed by their guardians) was used to investigate the use of electronic products in the families of preschoolers in April 2019. 【Results】 A total of 23 407 valid questionnaires were collected in this survey, of which 12 593 (53.80%) were boys and 10 814 (46.20%) were girls; and 17 188(73.43%) children were 5 years old. Among the surveyed children, the rate of excessive exposure to electronic screens (>1h/d) was 37.72%, and 6.40% of preschool children used electronic products for more than 2 hours per day. There were statistically significant differences between the excessive exposure group and the non-excessive exposure group in gender, household registration, parents′ educational level, average monthly household income, whether exclusive electronic products,whether restriction of children′s use of electronic products, whether living with elders, only children or not, and the type of main caregiver (P<0.05). Multivariate binary Logistic regression analysis showed that girls, mothers with college education or above,not living with elders,primary caregivers being parents or nannies/others,and no exclusive electronic products were protective factors for children′s excessive exposure to electronic products(P<0.05).Non-household resident population,not-only child,and non-restriction of children′s use of electronic products were risk factors for children′s excessive exposure to electronic products(P<0.05). 【Conclusions】 The excessive use of electronic products in preschoolers is a common phenomenon in Longhua district, Shenzhen. Therefore, it is necessary to strengthen the intervention on the use time of electronic products in preschoolers, and pay more attention to the influence of family environmental factors.

Objective: To study the expression of TNF-α and PCNA in human breast tissue with polyacrylamide hydrogel(PAHG) injection, and to provide the initial theory basis for its prognosis and clinical treatment. Methods: Immunohistochemistry was used to measure the expression of tumor necrosis factor α(TNF-α)and proliferating cell nuclear antigen (PCNA) in 20 normal breast tissues and 40 cases with PAHG injection, analysis was also done by HE staining. Results: ①HE staining showed that there were a large number of homogeneous amorphous gel-like injections under optical microscope. Around PAHG there were different degrees of fibrous tissue hyperplasia with or without fibrous degeneration and lots of inflammatory cells. Local foreign body giant cell reaction and ductal dilatation also can be seen around PAHG. ②The IA levels of TNF-α and PCNA in the experimental group were 3.9± 0.3 and 3.2 ± 0.2, the IA levels of TNF-α and PCNA in the control group were 1.0 ± 0.1 and 1.3 ± 0.3, the IA level in the experimental group was significantly higher than that in the control group (P=0.000). The difference was statistically significant. The positive rates of TNF-α and PCNA in the experimental group were 90% (36/40)and 85% (34/40)respectively; the positive rates of TNF-α and PCNA in the control group were 30% (6/20), 40% (8/20). The positive expression rate in the experimental group was significantly higher than that in the control group (P=0.000). The difference was statistically significant. TNF-α and PCNA has Pearson positive relevance in the changes(r=0.3, P=0.040), the difference was statistically significant. Conclusions TNF-α and PCNA are involved in the immunoreaction of mammalian breast tissue injected with polyacrylamide hydrogel, which may induce the aseptic inflammation, fibrous tissue hyperplasia and related issues through mutual influence.

At present,the treatment of non-small cell lung cancer (NSCLC) has entered the era of targeted therapy,and small molecule tyrosine kinase inhibitors are typical representatives,which have clear molecular targets and remarkable effects.But many patients without mutations are not able to benefit from them.Vascular endothelial growth factor and immune targeted therapy have become the new focus of NSCLC treatment.Inhibitors such as programmed cell death-1 and programmed cell death-ligand 1 have shown great applied potential in a series of clinical trials of NSCLC.

Objective To investigate the role of different parenting styles plays in conduct problems of 3-years-old preschool children.Methods Participants were from 148 preschools in Longhua Shenzhen,China.A structured questionnaire covering family demographic characteristics,Conners' Parent Symptom Questionnaire and Egna Minnen Betraffande Uppfostran-Parents (EMBU-P) were conducted among primary caregivers of each child.There were 9289 valid participants in the analysis and logistic regression was used to assess the relationship between three dimensions of parenting (rejection,emotional warmth and control/overprotection) and conduct problems.Results After allowing for certain confounders,parental rejection (OR =1.17,P＜0.01) and control/overprotection (OR =1.03,P＜0.01) was positively associated with conduct problems and emotional warmth was negatively related to conduct problems (OR=0.98,P＜0.01).Stratified analysis showed a significant relationship between conduct problems and both parents' rejection (OR father=1.16,P＜0.01;OR motber=1.17,P＜0.01),father's emotional warmth (OR=0.96,P＜0.01) and mother's control/overprotection (OR=1.04,P＜0.01).This relationship did not vary between boys and girls and between single and not single children.Conclusion Influence of parenting should be taken into consideration in the prevention and intervention of conduct problems.

BACKGROUND:Hyperbaric oxygen (HBO) therapy can aleviate the skin flap congestion by improving the angiogenesis and increasing the oxygen content of blood in skin flaps. Although the HBO therapy ability to increase flap survival has been wel described, the research on the application of HBO pretreatment in skin flap transplantation does not arouse adequate concern.
OBJECTIVE: To investigate the effect of HBO pretreatment on early-stage flap congestion in the rat model of over-length dorsal random skin flaps.
METHODS: Thirty-six SD rats were randomly divided into control group (n=12), HBO pretreatment group (n=12) and HBO treatment group (n=12). Rats in the HBO pretreatment group received 4 days of HBO therapy prior to transplantation, once a day. Rats in the HBO treatment group received 4 days of HBO therapy after transplantation. Rats in the control group were raised in the normal conditions after flap transplantation. At postoperative days 3 and 5, rats were sacrificed and the samples were colected. The inflammation of flap tissues was detected using hematoxylin-eosin staining. The expression of vascular endothelial growth factor and transforming growth factor-β was analyzed by immunohistochemistry staining. The flap survival rate was calculated at postoperative day 5.
RESULTS AND CONCLUSION:The flap survival area of the HBO pretreatment group and HBO treatment group was larger than that of the control group (P < 0.05). At postoperative days 3 and 5, the expression levels of vascular endothelial growth factor and transforming growth factor-β in the flap tissue were higher in the HBO pretreatment group and HBO treatment group than the control group (P < 0.05). However, there was no significant difference in the flap survival area and the expression of vascular endothelial growth factor and transforming growth factor-β between HBO pretreatment and HBO treatment groups (P > 0.05). HBO pretreatment can increase the expression of vascular endothelial growth factor and transforming growth factor-β and promotes angiogenesis in random pattern flaps,thereby improving skin flap survival.

Objective To explore the addictive tendency of internet and its influence factors among adolescents in Longhua District of Shenzhen. Methods A total of 6552 Students were selected from Longhua District of Shenzhen us?ing randomly stratified cluster sampling method. They were inquired about their gender, grade, family type, behaviors of surfing internet, risk behaviors, and internet addiction tendency with a self-report structured questionnaire and the adoles?cent pathological internet use scale (APIUS). Results The prevalence of addictive tendency of internet was 9.0%(590/6552) among adolescents in Longhua District of Shenzhen. Multiple logistic regression analysis indicated that the addic?tive tendency of internet was significantly and positively associated with male (OR=1.32, P<0.05), living in Minzhi area (OR=1.66, P<0.01), secondary school stage (OR=1.62, P<0.01), uncomplete family type (OR=1.49, P<0.01), surfing in cy?bercafé frequently (OR=2.00, P<0.01), compared with surfing 0~2 h/d, surfing 2~4 h/d (OR=1.92,P<0.01), 4~5 h/d (OR=2.97, P<0.01) or more than 6 h/d (OR=4.90, P<0.01), playing games (OR=3.27, P<0.01), chatting (OR=2.80, P<0.01) or having other kinds of entertaining (OR=2.80, P<0.01), and having risky behaviors (OR=2.39, P<0.01). Conclusion The addictive tendency of internet is affected by multiple factors among adolescents in Longhua District of Shenzhen. There?fore, comprehensive intervention measures shall be used to regulate adolescents habits of using internet and prevent them from the internet addiction.

[ ABSTRACT] AIM:To investigate the effect of hydrogen sulfide ( H2 S) on airway inflammation induced by ozone (O3) exposure and its mechanisms.METHODS:C57BL/6 mice (n=32) were randomly divided into control group, O3 group, NaHS+O3 group and NaHS group.The mice in O3 group and O3 +NaHS group were exposed to 2.14 mg/m3 O3 for 3 h on days 1, 3 and 5, while the mice in control group and NaHS group were exposed to filtered air .NaHS (14μmol/kg) was administered intraperitoneally to the mice in NaHS group and O 3 +NaHS group 30 min before each exposure .After the last exposure for 24 h, the airway responsiveness was determined , and bronchoalveolar lavage fluid ( BALF) was collected for counting inflammatory cells and measuring total protein concentration .The lung tissues were collected for observing the morphological changes with HE staining .The levels of interleukin-6 ( IL-6 ) , interleukin-8 ( IL-8 ) , malondialdehyde ( MDA) and NF-κB p65 protein in the lungs were determined .RESULTS: Compared with control group , the airway re-sponsiveness, inflammatory cells, protein concentration, inflammation score, levels of IL-6, IL-8, MDA and NF-κB p65 in O3 group increased significantly , but these in NaHS+O3 group decreased compared with O 3 group.CONCLUSION: The present findings suggest that H 2 S attenuates O3 induced airway inflammation by inhibiting NF-κB expression and preventing lipid peroxidation .

Objective To explore the interaction between passive smoking and folic acid supplement during pregnancy on children autism spectrum disorder (ASD) behaviors.Methods Children aged about 3 years were enrolled at kindergarten entrance in Longhua district of Shenzhen in 2014.Self-administered questionnaires were completed by their primary caregivers and the information about children' s age,gender,history of preterm birth and low birth weight,parents' education level,parents' reproductive age and family income were collected.The children ASD behaviors were assessed with Autism Behavior Checklist (ABC).According to the cut point of ABC,the children were divided into normal group with score less than 31,sub-clinical group with score ranging from 31 to 61 and suspect clinical group with score no less than 62.After controlling for potential confounders,multivariate logistic regression analysis was performed to evaluate the main effects and the interaction between passive smoking and folic acid supplement during pregnancy on children ASD behaviors.Results Maternal passive smoking during pregnancy was significantly associated with children ASD behaviors (sub-clinical group:OR=1.48;suspect clinical group:OR=2.85),and maternal folic acid supplement during pregnancy was not related to children ASD behaviors (sub-clinical group:OR=1.04;suspect clinical group:OR=0.75).Stratified analysis showed that folic acid supplement during pregnancy was negatively associated with children ASD behaviors (suspect clinical group:OR=0.30) among children without mothers' passive smoking during pregnancy,and that mothers' passive smoking during pregnancy was positively associated with children ASD behaviors (sub-clinical group:OR=1.52;suspect clinical group:OR=4.45) among the children whose mothers had folic acid supplement during pregnancy.Furthermore,an interaction effect on children ASD behaviors was found between passive smoking and folic acid supplement during pregnancy (suspect clinical group:OR=5.30).Conclusion Passive smoking and folic acid supplement during pregnancy were related to children ASD behaviors and had an interaction on children ASD behaviors.

Objective:To investigate the correlation between the plasma sphingomyelin (SM ) levels and the severity of coro‐nary artery disease in patients with coronary atherosclerotic heart disease(CAD) on admission .Methods:Clinical data of 464 pa‐tients undergoing coronary angiography were retrospectively analyzed ,which included 345 male cases and 119 female cases with mean age of 62 .71 ± 0 .46 .The patients were divided into stenosis group (n=327) and normal group (n=137) according to the results of coronary angiography .The severity of coronary artery stenosis was calculated according to Gensini score .The SM levels of all patients were measured on admission .Results:SM levels in control group and stenosis group were 39 .45 ± 0 .91 mg/dL ,45 .05 ± 0 .78 mg/dL ,respectively ,and the difference between the two groups was statistically significant (P<0 .001) .SM levels were positively correlated with Gensini scores(r=0 .155 ,P=0 .001) .The Gensini scores according to their tertiles of SM levels were 6(0‐38) ,18(2‐50) ,19(0‐49) ,respectively .The differences regarding Gensini scores among the three groups were statistically significant (P=0 .035) .After multiple related risk factors had been corrected ,the multivariate linear regression analysis showed that plasma SM levels were independently associated with Gensini scores (β=0 .143 ,95% CI 0 .148~0 .654 ,P=0 .002) .Conclusions:SM level was significantly associated with coronary angiography Gensini score ,and its level might be an independent risk factor for predicting the degree of coronary stenosis .SM might provide novel therapeutic tar‐get for the treatment of CAD .

Objective To investigate the changes of serum gastrin level in patients with colon cancer and the relationship between serum gastrin level and colon cancer occurrence and development.Methods Data of 35 patients underwent colon cancer surgery from January 2010 to January 2012 in our hospital were collected,at the same time data of 28 patients with colonic polyps and 30 cases of normal were collected as normal control.Serum gastrin levels were tested by radioimmunoassay in patients with colon cancer before surgery,1,3,7 d after surgery and they were analyzed.Results The serum gastrin level of patients with colon cancer was significantly increased compared with colon polyps and healthy controls((92.45 ± 12.98) ng/L vs (49.66 ±10.34) ng/L vs (30.12 ±6.39) ng/L;F =9.455,P ＜0.001)).Serum gastrin level in patients with obstructive colon cancer was significantly higher than that in non-obstructive cancer((129.84 ± 15.32) ng/L vs (75.34 ±11.45) ng/L,t =12.181,P ＜0.001) ;Serum gastrin levels in patients who cut off colon tumor was signifcanfly lower than before surgery((43.02 ±8.34) ng/L,(40.74 ±6.78) rig/L,(38.12 ±7.09) ng/L vs (89.45 ±12.98) ng/L;P ＜0.05).But no significant change of serum gastrin levels in patients with the colon tumor compared with the preoperative((97.34 +8.30) ng/L vs (95.82 ±7.20) ng/L vs (94.44 ±7.74) ng/L vs (100.23 ± 10.82) ng/L; P ＞ 0.05).But there was significant difference on serum gastrin levels between patients who cut off colon tumor and patients with the colon tumor(within groups:F =8.341,P =0.012 ;between groups:F =7.871,P =0.024).Conchusion Serum gastrin levels in patients with colon cancer were significantly higher than that of patients with colon polyps and normal controls.There was also a significant reduction of serum gastrin in tumor resection,and therefore gastrin may be involved in the development of colon cancer.