Objective: To understand the implementation of daily study time standard among secondary school students in Shandong Province, so as to provide scientific basis for the formulation and implementation of relevant policies. Methods: From January to May 2023, a multi stage random sampling method was used to select 8 725 middle school students in Shandong Province. A survey questionnaire was designed based on the Requirements for Daily Study Time of Primary and Secondary School Students(GB/T 17223-2012), to investigate indicators such as students daily learning schedule, sleep and physical activity time, break time and scheduling requirements. Results: The compliance rates for daily study time in junior and senior high school students in Shandong Province were 29.2% and 23.6%, respectively, with a statistically significant difference ( χ 2=33.63, P <0.01). Compliance rates for sleep duration, physical activity and recess time, morning and afternoon class hours, and class duration were 19.3%, 26.2%, 30.5%, 73.2% and 16.2%. Class duration compliance was relatively high, with rates of 96.7% in junior high and 94.4% in senior high school students. There was a statistically significant difference in compliance rates for extended class breaks between different educational stages ( χ 2= 81.78, P <0.01), with rates of 84.6% in junior high and 83.4% in senior high school students. As students progressed through their educational stages, compliance rates for physical activities, class breaks, consecutive classes, and total weekly class hours showed a decreasing trend, with rates of 31.8% and 18.3%, 35.7% and 23.1%, 60.5% and 29.6%, 55.2% and 35.1% in junior and senior high school students, respectively. Conclusions The revised standard of Requirements for Daily Study Time of Primary and Secondary School Students(GB/T 17223-2012) optimizes the daily study and life schedule of middle school students to a certain extent. However, daily study time for middle school students in Shandong Province exceeds standard. Relevant departments need to enhance their ability to implement standards and strengthen the supervision of policy standards implementation.

Objective:To investigate the biological effects of acute high-dose radon exposure on mice.Methods:BALB/c male mice aged 6 to 8 weeks were exposed once in an HD-3 ecological radon chamber with an average radon concentration of 7 × 10 5 Bq/m 3 for 10 h. Mice were weighed, their lung tissues and blood samples were collected at 1, 2 and 3 months after exposure. Control groups were set up at the three time points with four mice in each group. For these mice, the lung tissue pathology was observed using hematoxylin-eosin (HE) staining method, routine blood tests were conducted using a hematology analyzer and the levels of superoxide dismutase (SOD) and malondialdehyde (MDA) in the serum and lung tissues were measured using corresponding assay kits. Results:The HE staining result revealed that compared to the control groups, the experimental groups exhibited thickening of alveolar walls and increased infiltration of granulocyte, whose degrees, however, reduced over time and displayed no significant difference at 3 months after exposure. There was no significant difference in body weight or blood routine between the experimental and control groups. The detection result revealed decreased SOD levels in the lung tissues at 2 months after exposure, which were (11.34 ± 1.03) U/mgprot and (9.75 ± 0.71) U/mgprot, respectively for the control and experimental groups ( t = 2.54, P < 0.05). The MDA levels in lung tissue increased at 1 month after exposure, which were(2.30 ± 0.24) and (2.77 ± 0.29) nmol/mgprot, respectively for the control and experimental groups ( t = 2.49, P < 0.05). At 3 months after exposure, the SOD and MDA levels differed insignificantly between the control and experimental groups ( P > 0.05). Conclusions:After acute high-dose radon exposure, the mice suffered damage to the lung tissue, with changes in their oxidative stress indicators being detected. However, these effects gradually diminished at 3 months after exposure. Additionally, acute high-dose radon exposure did not give rise to significant changes in the body weight or routine blood result of the mice.

OBJECTIVE: To explore the effect and mechanism of schisandrin B (Sch B) in the treatment of cerebral ischemia in rats. METHODS: The cerebral ischemia models were induced by middle cerebral artery occlusion (MCAO) and reperfusion. Sprague-Dawley rats were divided into 6 groups using a random number table, including sham, MCAO, MCAO+Sch B (50 mg/kg), MCAO+Sch B (100 mg/kg), MCAO+Sch B (100 mg/kg)+LY294002, and MCAO+Sch B (100 mg/kg)+wortmannin groups. The effects of Sch B on pathological indicators, including neurological deficit scores, cerebral infarct volume, and brain edema, were subsequently studied. Tissue apoptosis was identified by terminal transferase-mediated dUTP nick end-labeling (TUNEL) staining. The protein expressions involved in apoptosis, inflammation response and oxidative stress were examined by immunofluorescent staining, biochemical analysis and Western blot analysis, respectively. The effect of Sch B on phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signaling was also explored. RESULTS: Sch B treatment decreased neurological deficit scores, cerebral water content, and infarct volume in MCAO rats (P<0.05 or P<0.01). Neuronal nuclei and TUNEL staining indicated that Sch B also reduced apoptosis in brain tissues, as well as the Bax/Bcl-2 ratio and caspase-3 expression (P<0.01). Sch B regulated the production of myeloperoxidase, malondialdehyde, nitric oxide and superoxide dismutase, as well as the release of cytokine interleukin (IL)-1 β and IL-18, in MCAO rats (P<0.05 or P<0.01). Sch B promoted the phosphorylation of PI3K and AKT. Blocking the PI3K/AKT signaling pathway with LY294002 or wortmannin reduced the protective effect of Sch B against cerebral ischemia (P<0.05 or P<0.01). CONCLUSIONS Sch B reduced apoptosis, inflammatory response, and oxidative stress of MCAO rats by modulating the PI3K/AKT pathway. Sch B had a potential for treating cerebral ischemia.

Objective:To summarize the patient profiles and therapeutic efficacies of ABO-incompatible living-related kidney transplantations at 19 domestic transplant centers and provide rationales for clinical application of ABOi-KT.Methods:Clinical cases of ABO-incompatible/compatible kidney transplantation (ABOi-KT/ABOc-KT) from December 2006 to December 2009 were collected. Then, statistical analyses were conducted from the aspects of tissue matching, perioperative managements, complications and survival rates of renal allograft or recipients.Results:Clinical data of 342 ABOi-KT and 779 ABOc-KT indicated that (1) no inter-group differences existed in age, body mass index (BMI), donor-recipient relationship or waiting time of pre-operative dialysis; (2) ABO blood type: blood type O recipients had the longest waiting list and transplantations from blood type A to blood type O accounted for the largest proportion; (3) HLA matching: no statistical significance existed in mismatch rate or positive rate of PRA I/II between two types of surgery; (4) CD20 should be properly used on the basis of different phrases; (5) hemorrhage was a common complication during an early postoperative period and microthrombosis appeared later; (6) no difference existed in postoperative incidence of complications or survival rate of renal allograft and recipients at 1/3/5/10 years between ABOi-KT and ABOc-KT. The acute rejection rate and serum creatinine levels of ABOi-KT recipients were comparable to those of ABOc-KT recipients within 1 year.Conclusions:ABOi-KT is both safe and effective so that it may be applied at all transplant centers as needed.

OBJECTIVE: To evaluate the effect of baicalin on subarachnoid hemorrhage (SAH) in rats and explore the potential mechanisms. METHODS: Sprague-Dawley rats underwent experimental SAH and received treatment with baicalin at 10 or 50 mg/kg after 2 and 12 h of SAH. Neurological scores, brain water content, Evans-blue extravasation, and levels of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), myeloperoxidase (MPO), and malondialdehyde (MDA) were measured 24 h after SAH. Expression of nuclear factor erythroid-related factor 2 (Nrf2), NAD(P)H: quinone oxidoreductase 1 (NQO1), matrix metalloproteinase-9 (MMP-9), aquaporin 4 (AQP4), occludin, and zonulaoccludens-1 (ZO-1) were detected in the brain by Western blot. Heme oxygenase-1 (HO-1) was detected by quantitative polymerase chain reaction, and tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) were assessed by enzyme-linked immunosorbent assay. RESULTS: Baicalin attenuated EBI 24 h after SAH in rats (P<0.05). Baicalin elevated neurological scores, GSH-Px, SOD, and increased the expression of Nrf2, NQO1, HO-1, occludin, and ZO-1 in SAH rats (P<0.05 or P<0.01). Baicalin reduced MPO, MDA, and the expression of MMP-9, AQP4, TNF-α, and IL-1β (P<0.05 or P<0.01). CONCLUSION Baicalin reduced SAH-induced EBI, partially via activation of the Nrf2/HO-1 pathway and inhibition of MMP-9 and AQP4.

Objective: To explore the expression of the N-methyl-D-aspartate (NMDA) receptor in the rat model of orchialgia and its possible mechanisms. METHODS: According to Yoshioka's method, the male rats in the control group were injected with 0.2 ml saline, and those in the experimental group with 0.2 ml 2% acetic acid solution. Then we tested the behavioral responses of the rats and determined the expressions of the subunits NR1 and NR2B of the NMDA receptor in the dorsal root ganglion and spinal dorsal horn by Western blot, RT-qPCR and immunofluorescence staining. RESULTS: The withdrawal latency was decreased in the model rats, reaching the lowest value at 4 hours after modeling, significantly lower than in the controls (［4.15 ± 0.84］ vs ［12.32 ± 1.05］, P < 0.05). Compared with the controls, the model rats showed remarkably increased mRNA and protein expressions of NR2B in the dorsal root ganglion (P < 0.05) but not in the spinal dorsal horn at 4 hours. However, no statistically significant difference was found in the expression of NR1 either in the dorsal root ganglion or in the spinal dorsal horn between the two groups (P > 0.05). CONCLUSIONS The NMDA receptor plays an important role in pathogenesis of orchialgia in rats. In the early stage of pain, upregulating the expression of the subunit NR2B of the NMDA receptor can mediate peripheral hyperalgesia and consequently orchialgia.

Objective To evaluate effects of antisense oligonucleotides against microRNA-155 (miRNA-155) on the proliferation,apoptosis,migration and invasion of a human cutaneous squamous cell carcinoma cell line A431.Methods A431 cells were divided into 3 groups:nonsense oligonucleotide group transfected with nonsense control oligonucleotides using liposomes,antisense oligonucleotide group transfected with antisense oligonucleotides against microRNA-155 using liposomes,and blank control group treated with Dulbecco's minimum essential medium (DMEM) containing Lipofectamine 2000.Real-time quantitative polymerase chain reaction (qRT-PCR)was performed to determine the expression of miRNA-155 in A431 cells:Methyl thiazolyl tetrazolium (MTT) assay was conducted to estimate cellular proliferative activity at 24,36,72,96 and 120 hours after transfection,flow cytometry to detect apoptosis and cell cycle changes,and Transwell assay to evaluate the migration and invasion of A431 cells.Statistical analysis was carried out by one-way analysis of variance (ANOVA) for intergroup comparisons and by least significant difference (LSD)-t test for multiple comparisons.Results After transfection,there were significant differences in the expression of miRNA-155 among the nonsense oligonucleotide group,antisense oligonucleotide group and blank control group (0.98 ± 0.02,0.28 ± 0.18,1.00 ± 0.01 respectively,F =634.57,P ＜ 0.001),and the expression of miRNA-155 was significantly lower in the antisense oligonucleotide group than in the blank control group and nonsense oligonucleotide group (both P ＜ 0.05).At 72,96 and 120 hours,there were significant differences in the survival rate of A431 cells among the 3 groups (all P ＜ 0.05),and the antisense oligonucleotide group showed a significantly lower survival rate of A431 cells compared with the blank control group and nonsense oligonucleotide group (all P ＜ 0.05).Additionally,the proportions of cells at G0/G1 phase and at S phase,and the cellular proliferative index all significantly differed among the 3 groups (F =23.46,36.81,19.35,respectively,P ＜ 0.01).The antisense oligonucleotide group showed significantly higher proportion of cells at G0/G1 phase (74.63％ ± 2.13％),but lower proportion of cells at S phase (9.88％ ± 1.83％) and cellular proliferative index (25.36 ± 2.13) compared with the blank control group(62.92％ ± 2.56％,18.86％ ± 2.78％,37.08 ± 2.56,respectively,all P ＜ 0.05) and nonsense oligonucleotide group (63.75％ ± 3.06％,18.33％ ± 3.72％,36.25 ± 3.06,respectively,all P ＜ 0.05).Additionally,the antisense oligonucleotide group showed significantly lower numbers of migratory cells and invasive cells compared with the blank control group and nonsense oligonucleotide group (all P ＜ 0.05).Conclusion Transfection of A431 squamous cell carcinoma cells with antisense miRNA-155 oligonucleotides can decrease the expression of miRNA-155,effectively inhibit the proliferation,migration and invasion of A431 cells,and promote cell apoptosis.

Objective To evaluate the effect of small interfering RNA (siRNA)targeting survivin gene on the expression of survivin and proliferation,apoptosis,migration and invasion of a human cutaneous squamous cell carcinoma cell line A431 in vitro.Methods A survivin-specific siRNA was designed and synthesized.Cultured A431 cells were divided into 3 groups to be transfected with 50.0 nmol/L liposome complexes containing survivin-specific siRNA (survivin siRNA group),50.0 nmol/L liposome complexes containing unrelated siRNA (negative control group) and 50.0 nmol/L prepared vesicles (blank control group).Real-time quantitative reverse transcription-PCR (RT-PCR) and Western blot analysis were performed to determine the mRNA and protein expression of survivin in A431 cells,respectively.Methyl thiazolyl tetrazolium (MTT) assay was conducted to evaluate cellular proliferative activity,flow cytometry using annexin-V/propidium iodide (PI) staining to detect cell apoptosis,Transwell assay to estimate migratory and invasive activities of A431 cells,and flow cytometry to detect cell cycle changes.Results At 48 hours after transfection,the mRNA and protein expression of survivin both significantly differed among the survivin siRNA group,negative control group and blank control group (mRNA:0.56 ± 0.15,0.88 ± 0.37,0.90 ± 0.43,F =276.67,P ＜ 0.001;protein:0.59 ± 0.04,0.86 ± 0.05,0.91 ± 0.07,F =243.61,P ＜ 0.001),the survivin siRNA group showed significantly lower mRNA and protein expression of survivin compared with the negative control group and blank control group (all P ＜ 0.05),and there were no significant differences between the negative control group and blank control group (both P ＞ 0.05).Repeated measures analysis of variance showed that the transfection with survivin siRNA could significantly inhibit the proliferation of A431 cells (F =13.19,P =0.004),the proliferation inhibition rate was significantly higher in the survivin siRNA group than in the negative control group and blank control group (both P ＜ 0.05),and no significant difference was observed between the negative control group and blank control group (P ＞ 0.05).At 24 hours after transfection,the apoptosis rate significantly differed among the 3 groups (F =83.97,P =0.002).The survivin siRNA group showed a significantly higher apoptosis rate compared with the negative control group and blank control group (both P ＜ 0.05),and there was no significant difference between the negative control group and blank control group (P ＞ 0.05).At 48 hours after transfection,the survivin siRNA group showed a significantly higher proportion of cells at G2/M phase,but lower number of migratory cells and invasive cells compared with the negative control group and blank control group (all P ＜ 0.05).Conclusion Survivin-specific siRNA can inhibit the expression of survivin gene and the proliferation of A431 cells,promote cell apoptosis,and suppress cell migration and invasion,indicating that survivin may serve as a genetic target for the treatment of cutaneous squamous cell carcinoma.

A comprehensively comparison of the chemical profiles between sun-drying BJ (NBJ) and sulfur-fumigated BJ (SBJ) was conducted by HPLC analysis and the discrepant peaks were identified or tentatively assigned by HPLC-ESI-MSn. A total of 32 chemical components were used for qualitative comparison. Meanwhile, a quantitative comparison of BJwere conducted by HPLC analysis and determining seven compounds from 3 NBJ and 3 SBJ samples dramatic chemical changes were found. After sulfur fumigation, the contents of flavonoids glycosides and phenolic acids were remarkably reduced, but the contents of flavonoids aglycones were significantly increased. Multivariate statistics, including principle component analysis (PCA) and partial least squares discriminate analysis (PLS-DA) were used to investigate the potential damaging effect of sulfur-fumigating process. The PCA score plots showed six samples were clearly classified into the sun-drying and sulfur-fumigating groups. And according to VIP >1, the most important chemical markers were apigenin, luteolin and 3,5-dicaffeoylquninic acid which could be used to distinguish NBJ and SBJ samples. Combining the results of qualitative and quantitative analysis, it showed that the sulfur fumigation has a significant effect on BJ.
Chromatography, High Pressure Liquid ; Chrysanthemum ; chemistry ; Fumigation ; Least-Squares Analysis ; Principal Component Analysis ; Sulfur