ObjectiveTo understand the trend and influencing factors of vitamin A status among students from the pilot area of the "Nutrition Improvement Program for Compulsory Education Students in Rural Areas" (Shorten as "Program") in Hainan Province from 2014 to 2017.MethodsFrom 2014 to 2017, a total of 2 603 students were selected from Qiongzhong county in Hainan Province through stratified cluster random sampling method. The serum retinol and other indicators were detected and questionnaire survey were carried out.ResultsIn 4 years, the average serum retinol concentration of students was (333.4±81.9)-(370.9±88.1) ng/mL, with an overall variation trend of decline and then increase (P<0.05); The subclinical vitamin A deficiency (SVAD) rate of students was 18.0% to 31.5%, which increased first and then decreased (P<0.05); and the vitamin A deficiency (VAD) rate was 0.8% to 2.0%, without significant change in 4 years (P>0.05). From 2014 to 2017, The serum retinol concentration of junior high school students was higher than that of primary school students (P<0.05), except for 2015, there was no statistically significant difference between different genders (P>0.05); and the SVAD rate of junior high school students was lower than that of primary school students (P<0.05). The minority nationality (OR=2.290) and anemia (OR=2.373) were risk factors for SVAD or VAD, the junior middle school students (OR=0.235) and daily outdoor activity time≥30 min (OR=0.554) were protective factors.ConclusionThe nutritional status of vitamin A among students in the region had been improved, but the SVAD was still a striking problem, the minority nationality and pupils were at higher risk, and improving anemia and increasing outdoor activity might help reduce the risk of SVAD or VAD in students.

以邻苯二胺为络合显色剂,采用紫外分光光度法测定海南澄迈富硒地瓜中微量元素硒的含量.结果表明,检测波长为337nm,线性方程为A=0.3225C+0.0383(R2=0.9998),硒在0～1.0μg/mL范围内相关性良好,相关系数γ=0.9999.提取条件为,混酸(硝酸:高氯酸=4:1)用量为10mL,酸度控制在pH=2,络合时间为60min,1％邻苯二胺溶液用量为2.5mL,5％EDTA-2Na溶液用量为2.0mL.富硒地瓜中总硒的平均含量为12.46μg/g.该方法操作简单,测定快速,灵敏度高,毒性较小,适用于检测富硒地瓜中微量硒的含量.

目的 了解预防医学本科生对岗位胜任力的认知情况.方法 采用自制问卷对某医学院校在读及已毕业的393名预防医学学生进行了问卷调查.结果 20.10％(79/393)的调查对象从来没听说过岗位胜任力,不同年级间差异显著,总体上呈现随年级和专业实践学时的增加其对岗位胜任力的认知更好的情况,毕业生的认知情况优于在校生,高年级的认知情况优于低年级.结论 针对预防医学专业学生对岗位胜任力普遍缺乏正确认识,缺乏对公共卫生执业医师考试情况的了解的现象,专业教师需进一步提升实践操作和岗位胜任力在教学中的比重,尤其是在低年级学生的教学中,研究结果为预防医学专业以提升学生岗位胜任力为目标的实践教学改革提供了理论依据.

Objective To investigate the status of malnutrition in students in poor areas of Hainan Province so as to provide a scientific basis for formulating nutritional improvement measures. Methods A stratified cluster sampling method was used to randomly select twelve primary schools and middle schools in poverty areas implemented the Nutrition Improvement Program for Rural Compulsory Students in Hainan Province. Students of 1-2 classes in each grade of the selected schools were chosen as the surveyed subjects, and their height and weight were measured according to the unified standard. Results A total of 5, 006 students, including 2, 636 boys and 2, 370 girls, were investigated. The detection rates of malnutrition and growth retardation were28.5％ and 4. 6％ respectively, and they were both higher in boys than in girls, higher in pupils than in junior middle school students and higher in township school students than in county school students, all showing statistically significant differences (all P＜ 0.05). The detection rate of mild weight loss was 9.8％, and it was higher in boys than in girls, showing a statistically significant difference (P＜ 0.05). The detection rate of moderate and severe weight loss was 14. 1％, and it was higher in Li nationality students, higher in boys than in girls, higher in pupils than in junior middle school students, higher in township school students than in county school students, all showing statistically significant differences (all P＜ 0.05). Conclusions Malnutrition rate is higher among students in poor areas of Hainan Province, especially in boys, pupils and township school students; and hence, special attention should be paid to them.

<span id="ChDivSummary" name="ChDivSummary" class="abstract-text">目的了解海南省贫困地区2016—2017学年7～15岁中小学生超重肥胖流行现况,为制定相关干预措施提供依据。方法采用分层整群抽样方法,随机选取海南省实施"农村义务教育学生营养改善计划"地区24所学校的4 722名中小学生为研究对象,通过身高、体重计算体质指数（BMI）,分析不同性别、年龄、城乡、民族的超重肥胖分布特征。结果共调查4 722名学生,超重和肥胖检出率分别为3.60%和2.01%。男、女生超重检出率分别为4.31%和2.82%,肥胖检出率分别为2.45%和1.52%,差异均有统计学意义;小学和初中学生超重检出率分别为3.35%和3.60%,差异无统计学意义,肥胖检出率分别为2.25%和1.38%,差异有统计学意义;汉族和少数民族学生超重检出率分别为3.67%和3.56%,肥胖检出率分别为2.28%和1.85%,差异均无统计学意义;县城和乡镇学校学生超重检出率分别为3.50%和3.65%,肥胖检出率分别为2.56%和1.73%,差异均无统计学意义。结论海南贫困地区中小学生超重肥胖检出率较低,但存在性别差异,男生超重肥胖检出率高于女生。</span>

目的 了解海南省少数民族地区中小学生维生素A (VA)和维生素D(VD)营养状况,为进一步制定营养干预措施提供参考依据.方法 采用多阶段整群随机抽样方法,抽取海南省琼中县和白沙县1～9年级中小学生(6～18岁)1055名,采集清晨空腹静脉血,采用高效液相色谱法(HPLC)和液相色谱-串联质谱法(LC-MS/MS)检测血清VA和VD水平.结果 中小学生血清视黄醇浓度为(1.17±0.29) μmol/L,初中生高于小学生,差异有统计学意义(P＜0.001);VA缺乏率3.8％,边缘缺乏率35.6％,小学生VA缺乏率和边缘缺乏率均高于初中生,差异有统计学意义(VA缺乏:P=0.001;VA边缘缺乏:P＜0.001).学生血清VD平均浓度为(0.066±0.014) μmol/L,小学生血清VD浓度高于初中生,男生高于女生,差异均具有统计学意义(均P＜0.001);VD缺乏率为0.0％,不足率12.1％,初中生VD不足率高于小学生,女生高于男生,差异均有统计学意义(均P＜0.001).多因素分析显示,影响学生血清视黄醇浓度的因素主要包括年龄、市县来源、供餐模式和民族,年龄越大血清视黄醇浓度越高,琼中县学生浓度高于白沙县,学校食堂供餐学生浓度高于企业供餐,汉族学生浓度高于少数民族;影响VD水平的因素主要包括性别、年龄、供餐模式和民族.男生血清VD水平高于女生,年龄越高VD水平越低,学校食堂供餐的学生VD水平高于企业供餐,少数民族学生VD水平高于汉族学生.结论 海南省少数民族地区学生中VA缺乏较少,但边缘缺乏较普遍;VD营养状况总体较好,但仍有部分学生VD不足,需采取针对性的措施进行营养干预.

目的 了解海南省三市县家长营养知识水平,分析影响因素,为中小学生家长的营养健康教育与干预提供理论依据.方法 采用自行设计的营养知识问卷,应用分阶段抽样方式对3 742名家长进行问卷调查.结果 海南省三市县家长膳食指南知晓率为28.89％,营养知识得分均值为(45.70±22.81)分.不同文化程度、不同职业、不同民族、不同区域之间家长膳食指南知晓率(Hc=57.972、22.650、17.223、64.655,P＜0.01)和营养知识得分(F=123.516、12.457、15.992,46.889,P＜0.01)差异均有统计学意义.不同亲缘关系之间营养知识得分差异有统计学意义(F=4.430,P＜0.01).Logistic分析发现,文化程度是影响膳食指南知晓率和营养知识得分的影响因素.结论 家长营养知识水平普遍较低,提高中小学生家长文化素养,多方式强化家长营养知识水平势在必行.

Objective To assess the level and prevalence rate of vitamin A deficiency (VAD) and sub-clinical vitamin A deficiency (SVAD) among primary and middle school students in the "Student Nutrition Improvement Program" implementing poverty areas in Hainan Province,to provide reference for further nutrition intervention measures.Methods A total of 4 primary schools and 4 middle schools were selected and students of 1-2 classes randomly chosen from every grade of the selected schools were enrolled in the study.Fasting venous blood samples were collected and serum retinol concentrations were measured using a high-performance liquid chromatography method.Results 1398 students were enrolled in this study.The average serum retinol concentration was (337.5±82.4) μg/L.The gender difference was statistically insignificant.Yet the serum retinol concentration increases with age.The overall prevalence rate of VAD and SVAD were 2.4％ and 31.1％,respectively.The VAD rate for boy students and girl students were 2.6％ and 2.1％,and SVAD rate of boy students and girl students were 31.6％ and 30.7％,respectively.The gender differences of both VAD and SVAD were statistically insignificant.The VAD rate of primary and middle school students were 3.1％ and 0.9％,respectively and the SVAD rate of the same groups were 38.8％ and 15.3％,respectively.The difference between primary and middle school students was statistically significant.Conclusion The overall vitamin A deficiency rate is not high among students in the study schools.But vitamin A in subclinical deficiency is still high.Targeted measures should be taken to carry out nutritional interventions

Objective To understand nutritional knowledge and associated factors among Li nationality students in the "Student Nutrition Improvement Program" carried out in undeveloped counties in Hainan Province.Methods By multistage sampling,1 826 Li nationality students from grade 3 to 9 in the "Student Nutrition Improvement Program" from undeveloped counties in Hainan Province were randomly enrolled in the study.Nutritional knowledge questionnaire survey was conducted among all students.Results The average score of the nutritional knowledge was (3.15 ± 1.71) points.Nutritional knowledge score showed significant differences in gender,grade,school meal providers,knowledge sources,boarding in school,left-behind children and area (t/F were-4.676,-6.692,7.645,93.074,3.194,-3.348 and 6.014,P＜0.01).Multiple regression analysis showed that grade,meal providers,gender,family population and area was main risk factor for nutritional knowledge.Average rate of nutritional knowledge awareness was 45.06％.Most of children were familiar with "iron-rich food to prevent anemia" and "vitamin-and mineral-rich food",while few of them were aware of "factors affecting height".The main source for students to acquire nutritional knowledge was campus publicity or classroom teaching(42.7％),parents or family (41.2％) and textbooks (38.7％).Conclusion Li nationality primary and middle school students in the "Student Nutrition Improvement Program" from the undeveloped counties in Hainan Province are lack of proper nutritional knowledge,grade,school meal provider,gender,family population and area plays a vital role.Targeted nutritional health education practice should be taken to improve students' nutritional awareness.

The volatile chemical components of guava fruit were analyzed by HS-SPME-GC-MS.The relative content of each component was calculated using the peak areas to determine the chemical compositions compared with computer retrieval and standard spectrogram.71 compounds were separated fiom guava fruit and 38 of them were identified,which accounted for 76.55％ of the volatile chemical components.Comparison of the relative contents of those volatile chemical components showed that:terpenes＞aldehydes＞esters＞alkanes＞ other compounds.The main components with higher relative mass fraction were hexanal (22.91％),(-)-β-caryophyllene (15.31％),cis-3-hexenyl acetate (8.52％),(E)-2-hexenal (6.45％),α-copaene (4.56％),D-limonene (3.84％),(+)-δ-cadinene (2.11％),(+)-aromandendrene (1.93％),Z,Z,Z-1,5,9,9-tetramethyl-l,4,7,-cycloundecatriene(1.54％),(-)-caryophyllene oxide (0.95％),(4E,6Z)-2,6-dimethylocta-2,4,6-triene (0.89％) and so on.The present study can provide scientific evidence for the further development and utilization of the biological activity of guava fruits.

Objective:To study the optimum extraction process of total flavonoids in fruits of Psidium guajava.Methods:An orthogonal experiment was designed to obtain the best extraction conditions,in which 4 factors (alcohol concentration,fruits:ethanol ratio,reflux time and extraction times)were examined,with the extraction rate of total flavonoids as the final indicator.The content of total flavonoids was determined by spectrophotometry at 508 nm.Results:The optimum extraction technology was identified as follows:extraction solvent,60 percent ethanol;fruits:ethanol ratio,1∶25;reflux time,2.5 h;extraction times,3 times.The linear ranges of the total flavonoids was 8.24-50.42 mg.mL-1 (r =0.999 9).The average recovery was 98.23％ (RSD =1.36％).The total flavonoids were 1.54％.Conclusion:The process proved to be simple and reasonable,with high extraction rate and feasibility.The determination method was easy and accurate which can be used for the study of total flavonoids in P.guajava.

Objective To establish a method for the simultaneous determination of berberin and cepharanthine in Stephania longa L.by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS).Methods The separation of the analytes were carried out on a Phenomenex Synergi Fusion-RP 80A column (2.0 mm×50 mm,4 μm) using methanol containing 0.1‰ formic acid as mobile phase,the column temperature was 40℃,flow rate was 0.35 mL/min,gradient elution.HPLC-MS/MS was performed in multiple reaction monitoring mode via positive electrospray ionization (ESI+).Results The calibration curves showed good linearity over the tested range from 5.0 to 1000.0 ng/mL for 2 compounds (the correlation coefficients＞ 0.98).The recoveries and the relative standard deviations of berberin and cepharanthine was 101.46％-104.76％,2.14％ and 95.96％-104.39％,4.63％ respectively.The content of berberin and cepharanthine in Stephania longa L.from Wenchang,Xinglong 2 areas were 0.889,1.07 μg/g and 7.62,38.0 μg/g.Conclusion The method is simple,fast and highly sensitivity,which can be used to control the quality of alkaloids from Stephania longa L..

(1.海南医学院药学院,海南海口 571199)(2.海南医学院公共卫生学院,海南海口 571199) 摘要:采用顶空固相微萃取(HS-SPME)结合气相色谱-质谱(GC-MS)联用技术分析番石榴果实中的挥发性成分。经计算机 检索与标准谱图对照,确定其化学成分,采用峰面积归一法计算各成分的相对含量。从番石榴果实中共分出 71 个色谱峰,初步鉴定 了其中的 38 种化学成分,占总挥发性化学成分的 76.55%。相对含量由高到低依次为萜烯类、醛类、酯类、烷类及其它类化合物,其 中主要成分为己醛(22.91%)、β-石竹烯(15.31%)、(顺)-乙酸叶醇酯(8.52%)、(E)-2-己烯醛(6.45%)、α-蒎烯(4.56%)、(D)-柠 檬烯(3.84%)、(+)-δ-杜松烯(2.11%)、(+)-香橙烯(1.93%)、Z,Z,Z-1,5,9,9-四甲基-1,4,7-环十一碳三烯(1.54%)、氧化石竹烯(0.95%)、 别罗勒烯(0.89%)等。本研究结果可为进一步开发和利用番石榴果实的生物活性提供基础研究数据。 关键词:番石榴果实;顶空固相微萃取(HS-SPME);气相色谱-质谱联用(GC-MS);挥发性成分 文章篇号:1673-9078(2017)11-230-234 DOI: 10.13982/j.mfst.1673-9078.2017.11.033

Objective To evaluate the implementing effect of the “Students Nutrition Improvement Plan” by analyzing the changing trend of malnutrition prevalence rate among primary and middle school students in Qiongzhong County between 2014 and 2016 in Hainan Province.Methods Schools in Qiongzhong County were grouped by the catering mode of “Students Nutrition Improvement Plan” as canteen meal schools and enterprise food schools.3 primary schools and 3 middle schools from each group were selected randomly as study sites.One or two classes were chosen randomly from each grade in the selected schools were included as study objectives.Body height and body weight of each objective were measured.Body mass index (BMI) was calculated and malnutrition was diagnosed by height-for-age and BMI-for-age.Results The number of objectives was 1978,1 818 and 2 730 respectively in 2014,2015 and 2016.The students'malnutrition prevalence rate was 30.3％,27.0％ and 26.0％ respectively in the same time period and the differences were statistically significant (P ＜ 0.05).The malnutrition rate of canteen food students has declined significantly (P ＜ 0.05) while declining rate of enterprise food students was insignificant (P ＞ 0.05).Conclusion The malnutrition prevalence rate of primary and middle school students in Qiongzhong County as a whole has declined from 2014 to 2016.But the malnutrition rate is still high.The improvement of students in enterprise food schools is insignificant.

An orthogonal experiment was designed to screen an optimum method for extraction of total alkaloids from Stephania hainanensis. The total alkaloids extracted was used as an index, and ethanol volume fraction, extraction time, altrasonic power, extraction frequency were used as factors to design the orthogonal experiment to optimize the altrasonic extraction of the total alkaloids from S. hainanensis. The content of total alkaloids extracted was determined by using spectrophotometry at 418 nm with berberine hydrochloride as a reference substance. The extraction was identified optimum when the volume fraction of ethanol was 80%, the extraction time was 30 min, the altrasonic power was 160 W, the solid-liquid ratio was 1:20, and the extraction frequency was 2 times. Berberine hydrochloride had a good linear relationship (r=0.9994) at the range of 0~18.0 μg/mL. The average recovery was 99.03% (RSD=2. 38%). The content of total alkaloids extracted was 4.67%. This extraction technology was proved to be simple, time saving and higher in extraction rate. The determination method for total alkaloids was easy, highly sensitive and good in repeatability, and can be used for determination of the content of total alkaloids from S. hainanensis.

[目的]建立海南粪箕笃总生物碱含量测定的方法.[方法]以盐酸小檗碱为对照品,溴甲酚绿为酸性染料,在缓冲溶液pH =5.4条件下,于421 nm波长处测定其吸光度.[结果]粪箕笃在0～ 15.75 μg/ml浓度范围内线性关系良好(r=0.999 5),平均回收率为103.21％,RSD =0.30％.[结论]该法简便、灵敏度高、重复性好,可用于粪箕笃总生物碱的含量测定.

Objective: To develop the method for the simultaneous determination of 9 sulfonamides(SAs) residues in shrimps by high performance liquid chromatography and tandem mass spectrometry(HPLC-MS/MS).Methods: The sample was extracted with acetonitrile,defatted and purified and then concentrated by evaporation.The 9 analytes were separated with a mobile phase composed of methanol and 0.50 mmol/L aqueous ammonium acetate solution.The mass spectrometer was operated using multiple reaction monitoring(MRM).Results: The 9 drugs showed good linear correlation in the range of 0-100 ng/ml(γ>0.999 0).The average recovery rate was 75.3% to 95.6% at two concentration levels.The relative standard deviation was 4.5% to 13.5%.Conclusion: The results indicate that the HPLC-MS/MS assay is accurate,reliable,and sensitive,thus it is suitable for the determination of SAs in aquatic products.

According to the investivation of wile Dendrobium resources in ChangJiang,and basically understanding of the current situation of Dendrobium spp.,the important influence factor causing Dendrobium to be endangered was disscussed,and suggestions for Dendrobium resources protection were made for the development and application of Dendrobium plants,so as to provide scientific evidence for the substainable utilization of Dendrobium plants.

Objective: To establish a credible analytical method based on high performance liquid chromatography for the determination of malachite green(MG),crystal violet and their leuco-metabolites in aquatic product.Methods: The MG,crystal violet and their leuco-metabolites were extracted by acetonitrile,then were concentrated and purified.Samples were isolated by Waters UPLC BEH C18 column(2.1 mm×50 mm,diameter 1.7 μm)and determined with 0.5 mmol/L ammonium acetate∶acetonitrile(30∶70) as mobile phase.Results: The mean recovery rate of MG and leucomalachite green were in the range of 90.3%-102.83% and 85.10%-98.60%,respectively.Values of RSD were 4.96%-6.88% and 6.24%-11.65%,respectively.Conclusions: The method is simple,sensitive,stable and suitable for the determination of trace malachite green and leucomalachite green green in aquatic product.