Objective To investigate the photodynamic antitumor activity and chemical characteristics of pheophorbide A (PPBa)in vitro. Methods Breast cancer cells (MCF-7), lung cancer cells (A549), cervical cancer cells (HeLa), and three kinds of hepatoma cells (HepG2, hep3B and sk-Hep1) were planted in 96-well plates.The effects of light and dark toxicity, light intensity, and drug concentration on the phototoxicity of PPBa were investigated by MTT, and the uptake of PPBa was observed by Hoechst staining under a confocal microscope.The production of singlet oxygen was observed by flow cytometry and confocal microscopy with the reactive oxygen species detection kit.The photobleaching of PPBa was investigated by measuring the absorbance by a microplate reader according to the luminescence characteristics of PPBa. Results PPBa showed strong phototoxicity and low dark toxicity to six kinds of cancer cells, and IC₅₀ values to cancer cells were as follows: MCF-7:1.033 μmol/L, A549:1.911 μmol/L, HeLa: 2.319 μmol/L, HepG2:2.015 μmol/L, Hep3B: 2.089 μmol/L, sk-Hep1:2.467 μmol/L.The main uptake site of PPBa was the cytoplasm.The production of singlet oxygen was strongly dependent on the administration concentration, and photobleaching was very low. Conclusion For the six kinds of cancer cells, PPBa has the highest phototoxicity to breast cancer cells (MCF-7), with excellent properties and ideal photosensitizer characteristics.

Objective: To understand literacy development of school-aged children of grade 2-5 and its influencing factors in Guangzhou,and to provide a reference for the reform of the teaching of Chinese subject. Methods: By using cluster sampling method, 1 661 school-age children from grade 2 to grade 5 from 5 primary schools in Guangzhou were selected. The self-designed questionnaire was used to obtain demographic data of the participants. The Primary School Literacy Assessment Scale and the Pupil Rating Scale Revised Screening for Learning Disabilities was used to evaluate the literacy and the cognitive characteristics of participants. Results: The average literacy of children of grade 2 to grade 5 in Guangzhou was as follows: grade 2 was (1 159±295), grade 3 was (1 919±394), grade 4 was (2 599±365), grade 5 was (2 947±303), higher than the norm(P<0.01). The average literacy of grade 2 students was lower than the national curriculum requirements while students of grade 3 to grade 5 met the requirements. Univariate analysis found differences in literacy among school-age children based on gender, reading experience before age 6, and parental education background (P<0.01). Multiple linear regression analysis revealed that grade (β=607.04), preschool reading experience (β=109.89), father’s education (β=27.14), language factor (β=27.21), social behavior (β=16.03) was positively correlated with literacy in boys (P<0.05). Grade (β=603.53), auditory comprehension and memory (β=29.39), language factor (β=16.74) was positively correlated with the literacy of girls (P<0.05), while time and orientation judgments were negatively correlated with the literacy of both boys (β=-18.95) and girls (β=-21.93) (P<0.05). Conclusion The literacy level of school-age children in grade 2 to 5 in Guangzhou has reached the national literacy requirements with students in grade 2 being relatively lower. Literacy is related to grade, preschool reading experience, father’s education, and child’s cognitive characteristics. Factors affecting literacy in boys and girls are different. Literacy education should vary according to gender.

Objective: This study aims to explore the influence of birth order and age difference on the emotional and behavioral problems among children from two-child family, so as to provide advice on parenting. Methods: A total of 482 students in grades 2 to 5 from the 5 primary schools in Guangzhou were selected, all of whom came from two-child families (excluding twin children). Emotional and behavioral problems were investigated by using the Conner’s Parental Symptom Questionnaire (PSQ). Results: Among children from two-child families, higher prevalence of behavioral problems, learning problems, impulsive hyperactivity and hyperactivity index in older compared with younger children (β=-0.09，-0.16，-0.09，-0.10,P<0.05). The scores of behavioral problems and hyperactivity index were significantly higher among those of children who were 6-9 years older than young siblings, compared to those who were 0-3 years older than younger siblings(β=0.20,0.21,P<0.05). No similar pattern was found among the younger siblings(P>0.05). Conclusion Among school-age children from two-child families, emotional and behavioral problems of the elder ones were more serious than the younger ones’. Age difference between siblings shows impact on the emotional and behavioral development among elder children, however no significant impact is noticed among the younger ones.

Identification of the risk factors for conversion to cesarean section during labor can significantly improve the mother and infant outcomes. Though advocated by the International Society of Ultrasound in Obstetrics and Gynecology (ISUOG), intrapartum ultrasound is not widely practiced in managing labor progress. The Obstetrics and Gynecology Center of Zhujiang Hospital of Southern Medical University has carried out intrapartum ultrasound in recent years. We summarize the clinical key point and the significance of measuring the major sonographic parameters during labor and illustrate the role of occiput-spine angle, a new sonographic index, in predicting fetal head descent during the first stage of labor.

Objective To analyze the clinical characteristics of thyroid dysfunction induced by camrelizumab in the treatment of classical Hodgkin lymphoma(cHL)and explore the influencing factors.Methods The medical records of cHL patients treated with camrelizumab from January 1st,2017 to December 31st,2020,were collected.The clinical characteristics of thyroid dysfunction induced by camrelizumab were analyzed,and the influencing factors of adverse drug reactions(ADRs)were discussed.Results A total of 47 patients were included,12 patients(25.53%)experiencing thyroid dysfunction after receiv-ing camrelizumab.Among them,3 patients had hypothyroidism,7 had subclinical hypothyroidism,and 2 had subclinical hyperthy-roidism.The severity of ADRs was between grade 1 and 2(mild to moderate).None of the patients with thyroid dysfunction dis-continued camrelizumab.Thyroid dysfunction occurred between 1 and 22 months after camrelizumab treatment,with a median time of 6 months.2 patients with hypothyroidism treated with levothyroxine,the thyroid function returned to normal in 1 patient and was improved in the other.1 patient with subclinical hypothyroidism was treated with levothyroxine with the thyroid function continued to be abnormal.The rest of the 9 patients with thyroid dysfunction received no intervention,and 4 of them returned to normal,and others remained with no obvious change or loss in follow-up.Thyroid dysfunction was associated with baseline thyroid stimulating hormone level(P=0.03).The level of thyroglobulin antibodies and thyroid peroxidase antibodies was increased in 2 patients a-mong 3 patients with moderate thyroid dysfunction.Conclusion The incidence of thyroid dysfunction induced by camrelizum-ab in cHL was high.Camrelizumab-induced thyroid dysfunction was related to TSH baseline level(P=0.03).The severity was between grade 1 and 2,which was related to the level of TgAb and TPOAb.The subtype of thyroid dysfunction was mainly sub-clinical hypothyroidism with a long period.Patients could continue camrelizumab treatment,and the thyroid function of patients with grade 2 hypothyroidism was improved after the treatment with levothyroxine.

Small interfering RNA-based RNA interference(RNAi)is an emerging treatment which has attracted more and more attention from both academia and industry. Studies on clinical translation of siRNA are popular in biomedical field, where safe and efficient carriers are necessary. As novel drug/gene vectors, dendrimers are widely used in siRNA delivery due to their unique and precise structure, multiple terminal groups and nano-sized chemophysical properties. Here, we present an overall view of current studies on dendrimer-based siRNA delivery systems, with the aim to provide an understanding of future siRNA therapeutics which could be used in clinic.

OBJECTIVE: To establish a method for detecting human urinary thiocyanate by gas chromatographic and pre-column derivatization with 2,3,4,5,6-pentafluorobenzyl bromide( PFB-Br). METHODS: A total of 20. 0 μL of urine was taken and 1. 0 m L of acetonitrile and 100. 0 μL of PFB-Br were added for derivative reaction. The gas chromatography was directly used for measurement. RESULTS: The urinary thiocyanate concentration showed a good linear range of 1. 000-10. 000 mg/L. The linear correlation coefficient was 0. 999 6. The minimum detection concentration was 0. 112 mg/L,and the minimum quantitative concentration was 0. 411 mg/L( 20. 0 μL urine sample). The standard recovery rate was 97. 22%-102. 04%.The within-run relative standard deviation( RSD) of this method was 1. 56%-5. 35%. The between-run RSD was 1. 46%-5. 10%. Hydrocyanic acid ions interfered with the measurement. Other common inorganic ions such as chloride,sulfate,and nitrate ions did not interfere with the measurement results. The samples can be stored at 4 ℃ for at least 15 days. CONCLUSION: This method is suitable for detecting human urinary thiocyanate.

OBJECTIVE: To establish a method for detecting dichloromethane,trichloromethane and 1,2-dichloroethane in blood by gas chromatography-mass spectrometry. METHODS: Using static headspace analysis, three halogenated hydrocarbons in blood samples were separated by DB-5 MS elastic capillary column and detected by gas chromatographymass spectrometry. RESULTS: There was a good linear relationship in the selected range of dichloromethane,trichloromethane and 1,2-dichloroethane in blood. The linear correlation coefficient was greater than 0. 999 8. The detection limit and the lower limit of quantitation was 0. 19-0. 28 and 0. 64-0. 93 μg/L,respectively. The average recovery rate was 95. 1%-106. 6%. The within-run and between-run relative standard deviation was 2. 9%-4. 9% and 5. 0%-7. 0%,respectively. The samples could be preserved at room temperature or 4 ℃ for 3 days and at-8 ℃ or below for7 days. CONCLUSION: With the features of high sensitivity,precision,accuracy,easy operation and less interference,this method is suitable for detecting dichloromethane,trichloromethane and 1,2-dichloroethane in the blood.

OBJECTIVE: To establish a headspace gas chromatography-mass spectrometry method for the determination of 14 chlorinated hydrocarbons in urine. METHODS: The urine sample 4.00 mL and anhydrous sodium sulfate 3.00 g were added into a 10.00 mL headspace bottle, then the headspace bottle was maintained at 70 ℃ for 40.0 min. After headspace pretreatment, 14 chlorinated hydrocarbons in headspace air were separated in the DB-5 MS capillary column of the gas chromatography and detected by mass spectrometer. RESULTS: There was a good linear relationship of 14 chlorinated hydrocarbons in urine in the range of 0.62-1 630.00 μg/L. The linear correlation coefficient was greater than 0.999 0.The minimum detectable concentration was 0.19-0.43 μg/L and the minimum quantitative concentration was 0.62-1.44 μg/L. The average recovery rate was 89.8%-107.1%. The within-run relative standard deviation(RSD) was 4.0%-8.5% and the between-run RSD was 6.3%-9.1%. Urine samples can be stored at 4 ℃ or-8 ℃ for 3 days and below-20 ℃ for 7 days. CONCLUSION: This method is rapid, simple, sensitive, accurate and has little interference,which can be used as a method for detecting 14 kinds of chlorinated hydrocarbons in urine samples of patients with occupational poisoning.