快速消解-石墨炉原子吸收法测定土壤中镉

目的建立测定土壤中镉含量的快速消解-石墨炉原子吸收法。方法土壤样品于石墨消解仪上120℃下消解1 h,冷却后直接以去离子水定容后用石墨炉原子吸收法测定土壤中镉含量。结果将土壤镉标准品用电热板湿法消解法、微波消解法和石墨快速消解法进行消解,检测结果的相对标准偏差(RSD)分别为7.6%、6.7%、3.6%。使用标准加入法和浓度外标法分别对6个土壤样品进行加标回收测定,标准加入法的回收率为90.8%~103.2%,浓度外标法的回收率为75.0%~91.6%。使用二次方程曲线拟合和一次方程曲线拟合对2个土壤标准样品进行测定,其相对误差分别为3.8%、5.0%和5.2%、8.6%。本实验在0μg/L~10.0μg/L时线性关系良好(相关系数r=0.999 3),方法检出限为2.0μg/kg,相对误差为3.8%~5.0%,相对标准偏差(RSD)为1.7%~3.5%。结论该方法前处理操作简单、快速、实用,检出限、准确度、精密度都能满足测定要求,适合于日常土壤样品中镉含量的快速测定。     

微波消解-石墨炉原子吸收光谱法测定水产品中痕量镉

目的:建立微波消解-石墨炉原子吸收光谱法测定水产品中镉含量的测定方法。方法:采用微波消解法对样品进行前处理,以磷酸二氢铵和硝酸镁为混合基体改进剂,采用Zeeman扣背景,利用石墨炉原子吸收法对样品中的镉进行测定。结果:镉在0.4μg/L~1.6μg/L范围具有良好的线性,相关系数大于0.999,RSD在4.3%~7.0%范围。采用本法对紫菜成分分析标准物质(GBW10023)和对虾成分分析标准物质(GBW08572)进行测定,与标准值比较其相对误差分别为1.8%和4.3%。结论:本法具有简便、灵敏、准确的优点,适合水产品中痕量镉的测定。     

微波消解-石墨炉原子吸收测定可能加入明胶的食品中铬的含量

目的建立微波消解技术进行样品前处理,结合石墨炉原子吸收光谱法,测定可能加入明胶的食品中的铬含量。方法采用微波消解技术处理样品,选用磷酸铵作基体改进剂。结果微波消解前处理一石墨炉原子吸收法测定可能加入明胶的食品中铬含量,样品测定的平均回收率为95.57%~102.2%,RSD为2.36%。结论该法具有操作简便、快速、准确、灵敏、精密度高等优点,可用于可能加入明胶的食品中铬的测定。     

微波消解—石墨炉原子吸收法检测动物肝脏中的镉

目的探讨用石墨炉原子吸收法检测动物肝脏中镉含量的最佳试验条件。方法将动物肝脏进行预处理和微波消解后,采用塞曼校正,石墨炉原子吸收光谱法自动进样测定样品中镉含量。结果方法线性范围为镉含量0.0μg/L~10.0μg/L,回归方程为y=0.038 5 x+0.007 3,线性系数0.999 2,检出限0.53μg/L;加标回收率在96.6%~101.30%之间;RSD值1.15%~3.90%。结论样品经过微波消解、赶酸、去离子水定容后可直接石墨炉自动进样检测,该法线性好,回收率高,变异小,操作简单,可用于动物肝脏中镉含量测定。     

微波消解-石墨炉原子吸收测定食品中铝的探讨

目的:通过对微波消解前处理条件和石墨炉原子吸收条件的最优化研究,达到快速、简便、准确地测定食品中铝的含量。方法:采用标准样品进行不同处理方法间的比对实验,来证明新方法准确度、精密度能满足现行标准的要求,灵敏度高于现行国标。结果:微波消解前处理-石墨炉原子吸收法测定食品中的铝,其平均回收率为98.3%,n=21,与国标法比较没有显著性差异。结论:微波消解前处理-石墨炉原子吸收法具有操作简便、快速、干扰少、灵敏度高的特点,能适用于食品中铝含量的测定。     

微波消解-石墨炉原子吸收法测定米粉中镉含量

目的建立检测米粉中镉含量的微波消解-石墨炉原子吸收光谱法,并对测定条件进行优化选择,达到快速、准确检测的目的。方法采用微波消解对米粉样品进行前处理,实验中以磷酸二氢铵为基体改进剂,通过优化灰化温度和原子化温度,在228.8 nm共振线,应用石墨炉原子吸收法测定米粉中镉的吸光度值,与标准系列比较定量。结果镉在0~4μg/L范围内线性关系良好,相关系数为0.999 1;最佳灰化温度为800℃,最佳原子化温度为1 200℃;方法检出限为0.065μg/L;精密度(RSD)为1.87%(n=6);回收率为95.5%~104.0%。结论微波消解石墨炉原子吸收法具有操作简便、快速、灵敏度高等特点,并有较高的回收率,能适用于米粉中镉的测定。     

智能样品处理器联用微波消解-石墨炉原子吸收光谱测定鲫鱼中痕量镉方法的建立

目的建立智能样品处理器联用微波消解-石墨炉原子吸收光谱法测定鲫鱼中痕量镉的新方法。方法智能样品处理器联用微波消解进行样品前处理,优化选择2种消解液及其加入量,调整横向塞曼石墨炉原子吸收光谱法测定的最佳状态直接测定样品中的痕量镉。结果镉含量在0~3 ng/ml范围内线性关系良好,相关系数为0.998 0。方法检出限为0.000 35 mg/kg,RSD为2.72%~4.88%,加标回收率为94.0%~98.7%。结论该方法空白值低,灵敏度高,可简便、快速、准确地进行大批量鱼样中镉的测定。     

湿式消解和微波消解-石墨炉原子吸收法对畜禽肉中镍含量的测定

目的建立畜禽肉中镍含量的石墨炉原子吸收测定方法。方法称取捣碎并混合均匀的样品,采用湿式消解和微波消解2种前处理方法处理样品,在选定的最佳仪器工作条件下,采用硝酸钯-磷酸二氢铵混合溶液为基体改进剂有效消除基体干扰,降低背景吸收,石墨炉原子吸收光谱法进行测定。结果本法在0.00μg/L~30.0μg/L具有良好的线性关系,标准曲线的相关系数为0.999 6,检出限为0.80μg/L;采用湿式消解法和微波消解法进行前处理所测得镍含量的相对标准偏差(RSD)分别为4.31%和3.58%,回收率分别为94.2%~103.0%和96.5%~102.0%。结论 2种前处理方法都具有较好的准确度和精密度,且操作简便、分析速度快、结果准确、适用性强,是较为理想的测定畜禽肉中镍含量的方法。     

微波消解—石墨炉原子吸收光谱法测定蔬菜中的微量镉

目的:建立微波消解—石墨炉原子吸收光谱法,用于蔬菜中微量镉的测定。方法:选择最优的微波消解条件进行消解,采用磷酸二氢铵作为基体改进剂,用石墨炉原子吸收光谱法进行蔬菜中镉含量的测定。结果:在优化的最佳消解条件和仪器检测条件下,方法具有很好的准确度和灵敏度,试验的RSD为2.4%~4.0%,回收率为95.8%~99.1%,检出限为0.010μg/L。结论:方法具有灵敏度高、稳定性好、检出限低、回收率高等特点,能满足蔬菜中镉含量的测定。     

微波消解-石墨炉原子吸收光谱法测定土壤中铅和镉

[目的]建立微波消解-石墨炉原子吸收光谱测定土壤中铅和镉的分析方法。[方法]土壤样品研磨过100目筛,用硝酸-氢氟酸-过氧化氢混合消解液微波消解后,石墨炉原子吸收光谱测定。[结果]铅浓度为5.0~40.0μg/L、镉浓度为0.20~2.00μg/L时,石墨炉原子吸收光谱测定土壤中铅和镉的方法线性良好,相关系数均为0.9999。铅和镉的方法定量检出限分别为5.0、0.040mg/kg。加标回收率为90.0%~110.0%,相对标准偏差为4.1%~6.9%,标样的测定结果在不确定度范围内。[结论]该方法简便、快速,基体干扰少,结果准确,适用于土壤中铅、镉含量的测定。     

企业职工高尿酸血症与血压、血脂、血糖的相关性研究

目的探讨企业职工高尿酸血症（HUA）与血压、血脂、血糖的相关性,为企业进行健康管理提供依据。方法以中国石油长庆油田公司各下属企业为抽样单位,整群随机抽取2个单位,每个单位中所有的HUA者作为HUA组,共720人;同时在尿酸水平正常者中随机选取620人为正常组。通过Logistic回归分析HUA与年龄、性别、血压、血脂、血糖的关系。结果HUA合并高血压、高血脂、空腹m糖受损任意一项、两项、三项的比例均远高于正常组（OR值分别为：4．036,2．562,4．174）。多因素Logistic回归发现：男性、收缩压、总胆固醇、三酰甘油、低密度脂蛋白胆固醇是HUA的危险因素（OR值分别为7．736,2．309,1．721,2．761,1．411）;高密度脂蛋白胆固醇为HUA的保护因素（OR值为0．211）。结论HUA存在性别差异,且与血压、血脂密切相关。企业对职工的健康管理应充分考虑多危险因素的综合作用,全面的进行健康教育及干预。     

Continuity and change in neighborhood disadvantage and adolescent depression and anxiety

We used data from the Fragile Families and Child Wellbeing Study which includes a sample of adolescents of age 15 at the most recent wave (between 2014 and 2017) from mainly low-income urban families in the United States, to examine the association between neighborhood poverty entries and exits and adolescent depression and anxiety. In addition, we examined whether these associations differed by gender. Adolescents who consistently lived in disadvantaged neighborhoods had the highest level of depression and anxiety. Those who entered poor neighborhoods were more depressed than those who never lived in poor neighborhoods. Those who exited poor neighborhoods showed no significant difference in depression and anxiety compared to those never lived in poor neighborhoods. Furthermore, these associations applied to adolescent girls only and were not statistically significant for boys. The results suggest that neighborhood poverty has cumulative negative impacts on adolescent mental health and disproportionally affects adolescent girls. Reducing neighborhood poverty would substantially improve the health of adolescents, especially girls, which would reduce health disparities.     

Enabling positive change: Progress and setbacks in HIV and sexual and reproductive health and rights

At a point in history when the future of sexual and reproductive health including HIV looks particularly uncertain, it is helpful to recognise that many of the challenges currently faced are neither new nor insurmountable. Reflecting on past achievements and lessons learned helps us to have confidence that positive change is feasible. This paper reflects on some of the changes observed in countries like India and Mozambique and identifies a range of factors which need to coalesce to enable these developments, along with specific contextual factors. It is the combination of these influences rather than any one of them alone that brought about the change in the three instances described – fostering a positive political response to HIV in its early years in India; bringing about policy reform on abortion in Mozambique; and increasing contraceptive prevalence and age at marriage in some districts in Bihar, India. Change is always fragile and susceptible to setbacks, but change-seekers can learn in the process and gain renewed hope that progress can and often does take place if they persevere.     

儿童青少年超重肥胖评价方法及SPSS和SAS实现

超重肥胖已成为世界各国儿童青少年面临的重大公共卫生问题之一。现行的儿童青少年超重肥胖筛查标准不统一,逐条评价或自行编写程序容易出错且效率较低。本研究以中国学龄儿童青少年超重与肥胖筛查标准为例,详细介绍了国际和中国共四种评价儿童青少年超重肥胖的方法和步骤,结合具体案例详细介绍其应用方法,同时编制SPSS和SAS程序包和解...     

癌缺氧病因及预防和治疗

目的 探讨癌及安阳林州市食管癌高发原因及癌病因预防和治疗措施.方法 对林州市食管癌等疾病现场进行调查,在进行10余年统计分析基础上,综合分析了全国156篇文献成果.结果 提出癌缺氧病因学说,使用制氧机、按摩器、饮用纯净水治疗恶性肿瘤,取得良好效果,改水能够大幅降低林州市居民食管癌发病率、死亡率.结论 癌可能是由于机体长...     

Recruitment and retention challenges and successes

Objective: Addressing health disparities requires well designed, culturally adapted research. However, recruiting/retaining minority participants has often been challenging. We present strategies used to successfully recruit and retain rural Hispanic women during a breastfeeding education intervention.

Design: This study involved a two-group repeated measures quasi-experimental design with assessments at seven intervals between enrollment and 6 months postpartum. Participants (Hispanic women?≥?15 years old) were recruited through a regional hospital.

Results: We successfully met our recruitment goals, most women contacted were enrolled (46 of 58), and 100% completed the study.

Discussion: Research staff with ties within the community helped establish trust. Using bilingual study materials, simple language, and an interpreter addressed language/literacy concerns. Phone assessments facilitated participation as transportation was an issue. Accommodating requests to deliver or mail study materials and providing incentives were important. Extra effort was needed to maintain contact when phone service was disrupted or participants moved. Keys to success were persistence, flexibility, and alleviating barriers to participation.     

Cholesterol and Egg Intakes with Cardiometabolic and All-Cause Mortality among Chinese and Low-Income Black and White Americans

We examined the associations of dietary cholesterol and egg intakes with cardiometabolic and all-cause mortality among Chinese and low-income Black and White Americans. Included were 47,789 Blacks, 20,360 Whites, and 134,280 Chinese aged 40–79 years at enrollment. Multivariable Cox models with restricted cubic splines were applied to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for mortality outcomes using intakes of 150 mg cholesterol/day and 1 egg/week as the references. Cholesterol intake showed a nonlinear association with increased all-cause mortality and a linear association with increased cardiometabolic mortality among Black Americans: HRs (95% CIs) associated with 300 and 600 mg/day vs. 150 mg/day were 1.07 (1.03–1.11) and 1.13 (1.05–1.21) for all-cause mortality (P-linearity = 0.04, P-nonlinearity = 0.002, and P-overall < 0.001) and 1.10 (1.03–1.16) and 1.21 (1.08–1.36) for cardiometabolic mortality (P-linearity = 0.007, P-nonlinearity = 0.07, and P-overall = 0.005). Null associations with all-cause or cardiometabolic mortality were noted for White Americans (P-linearity ≥ 0.13, P-nonlinearity ≥ 0.06, and P-overall ≥ 0.05 for both). Nonlinear inverse associations were observed among Chinese: HR (95% CI) for 300 vs. 150 mg/day was 0.94 (0.92–0.97) for all-cause mortality and 0.91 (0.87–0.95) for cardiometabolic mortality, but the inverse associations disappeared with cholesterol intake > 500 mg/day (P-linearity ≥ 0.12; P-nonlinearity ≤ 0.001; P-overall < 0.001 for both). Similarly, we observed a positive association of egg intake with all-cause mortality in Black Americans, but a null association in White Americans and a nonlinear inverse association in Chinese. In conclusion, the associations of cholesterol and egg intakes with cardiometabolic and all-cause mortality may differ across ethnicities who have different dietary patterns and cardiometabolic risk profiles. However, residual confounding remains possible.     

骨钙素与儿童生长发育

骨钙素是成骨细胞分泌的骨蛋白 ,骨钙素水平与成骨细胞活性成正相关 ,是一项很好的反映骨形成与骨转化的生化指标。小儿骨生长发育有自身特点 ,骨钙素水平的改变类似儿童身高生长曲线 ,可以很好地应用于评价儿童生长发育及监测生长障碍患儿对治疗的反应