1.Electroacupuncture Ameliorates NLRP3-mediated Pyroptosis in Spinal Cord Injury Rats by Reshaping The Gut Microbiota
Yin-Jie CUI ; Hong-Ru LI ; Jing-Yi LIU ; Hai-Lin DU ; Shu-Wen LIU ; Yuan YANG ; Chen-Guang ZHENG ; Jian-Qin XIANG ; Xiao-Juan SONG
Progress in Biochemistry and Biophysics 2026;53(5):1132-1153
ObjectiveSpinal cord injury (SCI) directly impairs the regulatory function of the autonomic nervous system, induces intestinal dysfunction, and significantly reduces patients’ quality of life. Preclinical studies have shown that electroacupuncture (EA) therapy can regulate the brain-gut axis and is used to treat central nervous system diseases such as major depressive disorder, Alzheimer’s disease and Parkinson’s disease. Recent research has established that fecal microbiota transplantation (FMT) from EA-treated SCI rats restored intestinal motility and colonic morphology. However, it remains unclear whether the regulation of gut microbiota by EA therapy directly contributes to neural repair after SCI. This study aims to explore whether gut microbiota mediates the neuroprotective effect of EA in the treatment of SCI and its possible mechanism. MethodsThe study employed RNA transcriptome analysis of spinal cord tissue to characterize gene expression profiles and to identify key signaling pathways following EA treatment for SCI. Hematoxylin-Eosin (HE) staining and Nissl staining were used to observe the morphological changes in spinal cord tissue. Western blot (WB) and enzyme-linked immunosorbent assay (ELISA) were applied to detect the effects of EA on the expression of proteins related to nucleotide-binding domain leucine-rich repeat and pyrin domain-containing receptor 3 (NLRP3) -dependent pyroptosis. Using 16S rDNA sequencing, the study observed alterations in gut microbiota diversity and community composition in SCI rats. Prior to establishing SCI models, rats were pretreated with an antibiotic cocktail to induce gut dysbiosis, and the effects on intestinal function and spinal cord neural repair were evaluated. FMT was performed to investigate the regulatory effects of post-EA FMT on motor function, general status, liver and spleen indices, and NLRP3-mediated pyroptosis in SCI rats. ResultsEA improved motor function and reduced regulated neuronal cell death in SCI rats. Transcriptomic analysis demonstrated the activation of immune- and inflammation-related pathways post-SCI, including NOD-like receptors, nuclear factor-kappa B(NF-κB), and Toll-like receptor (TLR) pathways. EA primarily influenced intestinal inflammation and autoimmune functions. 16S rDNA sequencing illustrated that EA did not alter the diversity of gut microbiota. However, EA altered the gut microbiota composition in SCI rats, increasing Lactobacillus and Akkermansia genera while rebalancing the Firmicutes/Bacteroidetes ratio. Furthermore, depletion of gut microbiota by antibiotics disrupted the intestinal barrier, reduced the expression of intestinal barrier proteins Zonula Occludens-1 (ZO-1) and Occludin, elevated serum lipopolysaccharide-binding protein (LBP) levels, exacerbated spinal cord tissue damage, and hindered motor function recovery in SCI rats. FMT from donors treated with EA reduced LBP levels in the intestine, blood, and spinal cord of rats, inhibited the TLR4 myeloid differentiation primary response protein 88 (MyD88)-NF‑κB pathway and NLRP3-dependent pyroptosis, and improved motor function. On the other hand, FMT treatment resulted in decreased body weight and food intake, whereas FMT using EA-treated donors effectively alleviated these alterations. ConclusionEA effectively alleviated neuroinflammatory responses in rats with SCI, primarily through regulating the gut microbiota and suppressing the NLRP3-dependent pyroptosis signaling pathway.
2.Research progress on the association between physical activity and sleep quality in adolescents
WANG Jinxian*, LIU Yuan, WU Jian, WU Huipan, WANG Zhe, ZHANG Yingkun, WANG Yi, YIN Xiaojian
Chinese Journal of School Health 2026;47(1):140-143
Abstract
To promote adolescents active participation in physical activity and improve sleep quality, the article analyzes the relationship of adolescent physical activity with subjective sleep satisfaction, sleep latency, sleep continuity, sleep efficiency, and sleep duration. It explores potential mechanisms underlying the link between physical activity and sleep quality, including physiological mechanisms (circadian rhythms, body temperature, neuroendocrine systems, and immune function), and psychological mechanisms (stress relief, improvement of negative emotions, and promotion of mental relaxation). Based on existing research, it is recommended that adolescents engage in moderate to vigorous physical activity daily to promote improved sleep quality.
3.Mosquito monitoring and influence of meteorological factors on mosquito density around Beijing Capital International Airport, 2016-2022
Ran FENG ; Tie-zheng MA ; Si-jie ZHU ; Bo TIAN ; Fei QUAN ; Zhi-lin WU ; Xiao-tao LIU ; Fu-yuan ZHANG ; Song-jian ZHANG
Acta Parasitologica et Medica Entomologica Sinica 2026;33(1):40-48
Objective To understand mosquito density, species composition, and seasonal variations around the Beijing Capital International Airport(BCIA)and provide scientific evidence for mosquito-borne disease prevention and control. Methods Meteorological data were collected from 2016 to 2022, and mosquito density was monitored at seven surveillance sites around the BCIA from May to October each year using CO2-baited mosquito traps to analyze the relationship between mosquito density and meteorological factors. Results In total,68 518 female mosquitoes were captured, with a mosquito density of 10.20 per light · hour. The dominant species was Culex pipiens pallens(73.90%), followed by Aedes albopictus(9.71%)and Ae. vexans(9.29%);the mosquito density was highest in 2016(14.8 per light·hour)and lowest in 2022(4.46 per light·hour). Significant statistical differences were observed in mosquito density among different species(F=18.118, P<0.05). The density of Cx. pipiens pallens and other mosquito species showed a mutually exclusive trend; the peak of mosquito density varied based on years and habitats, with significant statistical differences in mosquito density among different habitats(F=8.504, P<0.05). The highest mosquito density was observed near the Wenyu River(21.50 per light·hour), whereas the lowest was recorded at the BCIA construction site(2.44 per light· hour). The monthly average temperature(r=0.595), monthly average highest temperature(r=0.575), and monthly average lowest temperature(r=0.624)showed moderate positive correlations, whereas the monthly average air pressure(r=-0.484)showed a moderate negative correlation. The monthly average minimum temperature was included in the regression model(F=25.575, P<0.000), and the equation Y=1.029X4-8.181 was used. The monthly average air pressure 2 months prior(b=-2.418, β=-1.619, P<0.05)and the monthly average relative humidity(b=-0.739, β=-1.201, P<0.05)significantly negatively predicted the mosquito density. Notably, the regression equation used was y=2526.170+(-2.418)X9+(-0.739)X13. The exposure-response analysis revealed that the density of mosquitoes was not linearly related to the average monthly air pressure, rainfall, and duration of sunshine. Conclusions The dominant mosquito species around the BCIA was Cx. pipiens pallens, Ae. albopictus, and Ae. vexans. During the control of Cx. pipiens pallens, the impact on other mosquito species must also be considered. Environmental management, breeding sites, and scientific use of pesticides should be prioritized based on the activity periods of mosquitoes. Further studies on mosquitoes and meteorological factors should be conducted to provide references and novel avenues for mosquito control.
4.Electroacupuncture Ameliorates NLRP3-mediated Pyroptosis in Spinal Cord Injury Rats by Reshaping The Gut Microbiota
Yin-Jie CUI ; Hong-Ru LI ; Jing-Yi LIU ; Hai-Lin DU ; Shu-Wen LIU ; Yuan YANG ; Chen-Guang ZHENG ; Jian-Qin XIANG ; Xiao-Juan SONG
Progress in Biochemistry and Biophysics 2026;53(5):1132-1153
ObjectiveSpinal cord injury (SCI) directly impairs the regulatory function of the autonomic nervous system, induces intestinal dysfunction, and significantly reduces patients’ quality of life. Preclinical studies have shown that electroacupuncture (EA) therapy can regulate the brain-gut axis and is used to treat central nervous system diseases such as major depressive disorder, Alzheimer’s disease and Parkinson’s disease. Recent research has established that fecal microbiota transplantation (FMT) from EA-treated SCI rats restored intestinal motility and colonic morphology. However, it remains unclear whether the regulation of gut microbiota by EA therapy directly contributes to neural repair after SCI. This study aims to explore whether gut microbiota mediates the neuroprotective effect of EA in the treatment of SCI and its possible mechanism. MethodsThe study employed RNA transcriptome analysis of spinal cord tissue to characterize gene expression profiles and to identify key signaling pathways following EA treatment for SCI. Hematoxylin-Eosin (HE) staining and Nissl staining were used to observe the morphological changes in spinal cord tissue. Western blot (WB) and enzyme-linked immunosorbent assay (ELISA) were applied to detect the effects of EA on the expression of proteins related to nucleotide-binding domain leucine-rich repeat and pyrin domain-containing receptor 3 (NLRP3) -dependent pyroptosis. Using 16S rDNA sequencing, the study observed alterations in gut microbiota diversity and community composition in SCI rats. Prior to establishing SCI models, rats were pretreated with an antibiotic cocktail to induce gut dysbiosis, and the effects on intestinal function and spinal cord neural repair were evaluated. FMT was performed to investigate the regulatory effects of post-EA FMT on motor function, general status, liver and spleen indices, and NLRP3-mediated pyroptosis in SCI rats. ResultsEA improved motor function and reduced regulated neuronal cell death in SCI rats. Transcriptomic analysis demonstrated the activation of immune- and inflammation-related pathways post-SCI, including NOD-like receptors, nuclear factor-kappa B(NF-κB), and Toll-like receptor (TLR) pathways. EA primarily influenced intestinal inflammation and autoimmune functions. 16S rDNA sequencing illustrated that EA did not alter the diversity of gut microbiota. However, EA altered the gut microbiota composition in SCI rats, increasing Lactobacillus and Akkermansia genera while rebalancing the Firmicutes/Bacteroidetes ratio. Furthermore, depletion of gut microbiota by antibiotics disrupted the intestinal barrier, reduced the expression of intestinal barrier proteins Zonula Occludens-1 (ZO-1) and Occludin, elevated serum lipopolysaccharide-binding protein (LBP) levels, exacerbated spinal cord tissue damage, and hindered motor function recovery in SCI rats. FMT from donors treated with EA reduced LBP levels in the intestine, blood, and spinal cord of rats, inhibited the TLR4 myeloid differentiation primary response protein 88 (MyD88)-NF‑κB pathway and NLRP3-dependent pyroptosis, and improved motor function. On the other hand, FMT treatment resulted in decreased body weight and food intake, whereas FMT using EA-treated donors effectively alleviated these alterations. ConclusionEA effectively alleviated neuroinflammatory responses in rats with SCI, primarily through regulating the gut microbiota and suppressing the NLRP3-dependent pyroptosis signaling pathway.
5.Investigating the nuclear radiation health emergency response capacity of nuclear power plants sites in Guangdong Province
Jian HUANG ; Jiaxin JIANG ; Weixu HUANG ; Long YUAN ; Xiaoyong LIU ; Haihui LIN
China Occupational Medicine 2026;53(2):207-211
Objective To investigate the existing nuclear radiation health emergency response capacity of local health systems at nuclear power plant sites in Guangdong Province. Methods The health administrative departments of all nuclear power plants sites in Guangdong Province, along with radiation health protection institutions, designated nuclear radiation treatment hospitals, and township health centers, were selected as the study subjects using the purposive sampling method. A series of standardized questionnaires on the capacities for nuclear radiation health emergency response, developed uniformly by the National Institute for Radiological Protection, Chinese Center for Disease Control and Prevention, were adopted to separately investigate the capacities for nuclear radiation health emergency response in the study subjects. Results There were 13 health administration departments, 15 radiological health protection institutions, 18 designated hospitals for nuclear radiation medical response, and 18 township health centers located in the nuclear power plants sites in Guangdong Province. Among the 13 health administration departments, the Health Commission of Guangdong Province met all 15 criteria for nuclear radiation health emergency response capacities. All six prefecture-level health administrative departments possessed more than 10 capacities for nuclear radiation health emergency response, while only one of the six county-level departments had more than 10 such capacities. Among radiation health protection institutions, the provincial-level institution possessed all 18 capacity for nuclear radiation health emergency response; of the six prefectural-level institutions, only four had more than 10 capacities; none of the eight county-level institutions or 18 township health centers possessed more than 10 capacities. Among designated nuclear radiation treatment hospitals, provincial-level institution met all 32 capacities for nuclear radiation health emergency response; of the eight prefecture‑level hospitals, only four meet more than ten such capacities; and of the nine county‑level hospitals and 18 township health centers, none possess more than 10 capacities. Conclusion Provincial- and prefectural-level nuclear radiation emergency capacity in Guangdong Province is adequate, whereas county-level and township health centers have obvious weaknesses in organizational structure, personnel training, equipment reserves, funding, and technical reserves; emergency response capacity needs urgent enhancement.
6.Construction plan for prefecture-level nuclear radiation health emergency response teams in nuclear power plant sites
Xiaoyong LIU ; Jian HUANG ; Jiaxin JIANG ; Weixu HUANG ; Huifeng PENG ; Long YUAN
China Occupational Medicine 2026;53(1):37-42
Objective To analyze the current status of nuclear radiation health emergency response capacity in areas of the nuclear power plants in Guangdong Province, and to formulate a construction plan for municipal-level nuclear radiation health emergency response teams. Methods Provincial-, municipal-, and county-level administrative regions in the nuclear power plant host areas of Guangdong Province were selected as the study subjects. A series of questionnaires designed by the National Institute for Radiological Protection, Chinese Center for Disease Control and Prevention, were used to assess the capacity of nuclear radiation health emergency response. Based on the findings, a construction plan for municipal-level nuclear radiation health emergency response teams was formulated. Results A total of 13 administrative regions which host nuclear power plants were involved, including one provincial-level, six municipal-level, and six county-level regions. The availability rates of 31 capacity indicators of nuclear radiation health emergency response among 13 administrative regions ranged from 15% to 100%, with an average of 51%. Provincial-level capacity of nuclear radiation health emergency response was relatively well established, county-level radiation monitoring and protection capacity was nearly absent, municipal-level regions possessed basic capacity, but with obvious regional disparities and a general lack of specialized facilities and materials required for the treatment of nuclear radiation injuries, making them the key level for improvement in nuclear radiation health emergency response. The Construction Plan for Municipal-Level Nuclear Radiation Health Emergency Response Teams specifies that the total number of team members should be no fewer than 30 to ensure rapid response and immediate arrival at the scene. The List of Key Professional Equipment proposes the prioritized allocation of five categories of equipment: personal basic equipment, contamination detection and classification equipment, decontamination equipment, medical treatment equipment, and command and logistical support equipment. Conclusion Nuclear radiation health emergency response capacity in Guangdong Province requires further improvement, particularly in standardized development of municipal-level nuclear radiation health emergency response teams. The Construction Plan for Municipal-Level Nuclear Radiation Health Emergency Response Teams defines capacity requirements and provides a list of essential equipment, offering a practical reference for other regions.
7.An exploratory study on the effect of ultrasonic waves against Aedes albopictus larvae
Shuqing JIN ; Xinyi CAI ; Heyi WEN ; Jian FAN ; Hui CAO ; Tianyu SHA ; Hongxia LIU ; Yuan FANG ; Qiang GAO
Shanghai Journal of Preventive Medicine 2026;38(7):550-555
ObjectiveTo evaluate the larvicidal effect of ultrasonic waves against Aedes albopictus larvae at various exposure parameters (distance and time), and to preliminarily investigate the effects of different containers (water volume and depth) and ultrasonic devices on the larvicidal efficacy, so as to provide experimental evidence for the application of ultrasound-based mosquito control technology. MethodsUnder controlled laboratory conditions, two commercially available ultrasonic devices [40 kHz/300 W and (50±5) kHz/70 W] were used to systematically examine the effects of exposure distance (20, 40, 60, 80, and 100 cm), exposure duration (1, 3, 6, 15 and 60 min), larval instar(Ⅰ‒Ⅱ and Ⅲ‒Ⅳ), and container type on the immediate mortality of Aedes albopictus larvae collected from urban areas of Shanghai. Statistical analysis of the mortality rates of larvae among different experimental groups was performed using the chi-square test. ResultsUltrasonic exposure exerted a detectable larvicidal effect against Aedes albopictus larvae of all instars. For early-instar larvae, exposure time significantly affected mortality at all tested distances (20, 40, 60, 80 and 100 cm), with χ² values ranging from 25.57 to 32.74 ( all P<0.001). No significant distance effect was observed in the first and second instar larvae after short-term exposure (1 and 3 min; P>0.05). However, a distance-dependent effect emerged from 6 min onward (P<0.05). During short-term exposure (1 min and 3 min) at close range (20 cm and 40 cm), the immediate mortality of the third and fourth instar larvae was higher than that of the first and second instar larvae. Conversely, during prolonged exposure (15 min and 60 min), the first and second instar larvae exhibited significantly higher mortality than that of the third and fourth instar larvae. These results indicated that larval mortality was jointly influenced by exposure duration and distance. Preliminary experiments indicated that larvicidal efficacy in shallow water was lower than that in deep water. No significant difference in larvicidal effect was observed between the two ultrasonic devices with different frequencies and power outputs. ConclusionUnder laboratory conditions, ultrasound can effectively kill Aedes albopictus larvae, and the larvicidal effect is jointly influenced by larval instar, exposure distance, and aquatic environment. Compact ultrasonic devices show potential for field application in biological mosquito control.
8.Translational Research of Electromagnetic Fields on Diseases Related With Bone Remodeling: Review and Prospects
Peng SHANG ; Jun-Yu LIU ; Sheng-Hang WANG ; Jian-Cheng YANG ; Zhe-Yuan ZHANG ; An-Lin LI ; Hao ZHANG ; Yu-Hong ZENG
Progress in Biochemistry and Biophysics 2025;52(2):439-455
Electromagnetic fields can regulate the fundamental biological processes involved in bone remodeling. As a non-invasive physical therapy, electromagnetic fields with specific parameters have demonstrated therapeutic effects on bone remodeling diseases, such as fractures and osteoporosis. Electromagnetic fields can be generated by the movement of charged particles or induced by varying currents. Based on whether the strength and direction of the electric field change over time, electromagnetic fields can be classified into static and time-varying fields. The treatment of bone remodeling diseases with static magnetic fields primarily focuses on fractures, often using magnetic splints to immobilize the fracture site while studying the effects of static magnetic fields on bone healing. However, there has been relatively little research on the prevention and treatment of osteoporosis using static magnetic fields. Pulsed electromagnetic fields, a type of time-varying field, have been widely used in clinical studies for treating fractures, osteoporosis, and non-union. However, current clinical applications are limited to low-frequency, and research on the relationship between frequency and biological effects remains insufficient. We believe that different types of electromagnetic fields acting on bone can induce various “secondary physical quantities”, such as magnetism, force, electricity, acoustics, and thermal energy, which can stimulate bone cells either individually or simultaneously. Bone cells possess specific electromagnetic properties, and in a static magnetic field, the presence of a magnetic field gradient can exert a certain magnetism on the bone tissue, leading to observable effects. In a time-varying magnetic field, the charged particles within the bone experience varying Lorentz forces, causing vibrations and generating acoustic effects. Additionally, as the frequency of the time-varying field increases, induced currents or potentials can be generated within the bone, leading to electrical effects. When the frequency and power exceed a certain threshold, electromagnetic energy can be converted into thermal energy, producing thermal effects. In summary, external electromagnetic fields with different characteristics can generate multiple physical quantities within biological tissues, such as magnetic, electric, mechanical, acoustic, and thermal effects. These physical quantities may also interact and couple with each other, stimulating the biological tissues in a combined or composite manner, thereby producing biological effects. This understanding is key to elucidating the electromagnetic mechanisms of how electromagnetic fields influence biological tissues. In the study of electromagnetic fields for bone remodeling diseases, attention should be paid to the biological effects of bone remodeling under different electromagnetic wave characteristics. This includes exploring innovative electromagnetic source technologies applicable to bone remodeling, identifying safe and effective electromagnetic field parameters, and combining basic research with technological invention to develop scientifically grounded, advanced key technologies for innovative electromagnetic treatment devices targeting bone remodeling diseases. In conclusion, electromagnetic fields and multiple physical factors have the potential to prevent and treat bone remodeling diseases, and have significant application prospects.
9.Application of machine learning in the restoration of dentition defects
Xinxi YUAN ; Yekang XIA ; Han WANG ; Jian HU ; Laikui LIU ; Weiwei LIANG
STOMATOLOGY 2025;45(9):707-712,720
Machine learning,as a core branch of artificial intelligence,has gradually demonstrated significant potential in the field of dentition defect repair in recent years.By employing techniques such as data mining and pattern recognition,machine learning has been applied in various aspects including oral implant restoration,fixed bridge design,and fabrication of removable partial dentures.This paper seeks to provide a comprehensive review of machine learning applications within the aforementioned three aspects.It endeavors to assess the current developmental landscape and chart a course for future investigative endeavors,in hopes of offering a reference for re-search on machine learning in prosthodontics.
10.Compound Xishu Granules Inhibit Proliferation of Hepatocellular Carcinoma Cells by Regulating Ferroptosis
Yuan TIAN ; Yuxi WANG ; Zhen LIU ; Yuncheng MA ; Hongyu ZHU ; Xiaozhu WANG ; Qian LI ; Jian GAO ; Weiling WANG ; Wenhui XU ; Ting WANG
Chinese Journal of Experimental Traditional Medical Formulae 2025;31(2):37-45
ObjectiveTo study the mechanism of compound Xishu granules (CXG) in inhibiting the proliferation of hepatocellular carcinoma cells by regulating ferroptosis. MethodsThe transplanted tumor model of human Huh7 was established with nude mice and the successfully modeled mice were randomized into model, Fufang Banmao (0.21 g·kg-1), low-dose (1.87 g·kg-1) CXG, medium-dose (3.74 g·kg-1) CXG, and high-dose (7.49 g·kg-1) CXG groups. Mice were administrated with drinking water or CXG for 28 days, and the body weight and tumor volume were measured every 4 days. Hematoxylin-eosin staining was employed to observe the histopathological changes of tumors. The cell-counting kit-8 (CCK-8) was used to examine the survival rate of Huh7 cells treated with different concentrations (0, 31.25, 62.5, 125, 250, 500, 1 000 mg·L-1) of CXG for 24 h and 48 h. CA-AM, DCFH-DA, and C11-BODIPY581/591 fluorescent probes were used to determine the intracellular levels of ferrous ion (Fe2+), reactive oxygen species (ROS), and lipid peroxide (LPO), respectively. The colorimetric method was employed to measure the levels of glutathione (GSH) and superoxide dismutase (SOD). Western blot was employed to determine the protein levels of glutathione peroxidase 4 (GPX4), transferrin receptor 1 (TFR1), and ferritin heavy chain 1 (FTH1), respectively. ResultsIn the animal experiment, compared with the model group, the drug treatment groups showed reductions in the tumor volume from day 12 (P<0.01). After treatment, the Fufang Banmao and low-, medium-, and high-dose CXG groups had lower tumor volume, relative tumor volume, and tumor weight than the model group (P<0.05), with tumor inhibition rates of 48.99%, 79.93%, 91.38%, and 97.36%, respectively. Moreover, the CXG groups had lower tumor volume and relative tumor volume (P<0.05 in all the three dose groups) and lower tumor weight (P<0.05 in medium-dose and high-dose groups) than the Fufang Banmao group. Compared with the model group, the drug treatment groups showed reduced number of tumor cells, necrotic foci with karyopyknosis, nuclear fragmentation, and nucleolysis, and the high-dose CXG group showed an increase in the proportion of interstitial fibroblasts. In the cell experiment, compared with the blank group, CXG reduced the survival rate of Huh7 cells in a dose-dependent manner after incubation for 24 h and 48 h (P<0.05). Compared with the blank group, the RSL3 group and the low-, medium-, and high-dose CXG groups showed a decrease in the relative fluorescence intensity of CA-AM and increases in the fluorescence intensity of DCFH-DA and fluorescence ratio of C11-BODIPY581/591, which indicated elevations in the levels of Fe2+ (P<0.01), ROS (P<0.05), and LPO (P<0.01), respectively. Compared with the blank group, the RSL3 and low-, medium-, and high-dose CXG groups showed lowered levels of GSH and SOD (P<0.05). In addition, the RSL3 group and the medium- and high-dose CXG groups showed down-regulated expression of GPX4 and FTH1 (P<0.05), and the low- and high-dose CXG groups presented up-regulated expression of TFR1 (P<0.05). ConclusionCXG suppresses the proliferation of hepatocellular carcinoma cells by inducing ferroptosis via downregulating the GSH-GPX4 signaling axis and increasing intracellular Fe2+and LPO levels.


Result Analysis
Print
Save
E-mail