The preparation and certification of five China Sea and continental shelf sediment reference materials MSCS-1- 5 are reported. The raw samples were collected separately from the East China Sea and the South China Sea. First,they were ground by a ball mill to a homogenous powder of less than 74μm,then these samples was further processed by an ultra-fine processing technique,a jet mill,to form an ultra-fine powder. The particle size distribution of the samples was determined with a laser particle-analyser,their average particle size is < 4μm. The homogeneity was tested by high-precision WD-XRF and the minimum sampling mass is 5 mg,which was confirmed by XRF,ICP-AES and ICP-MS. Twelve laboratories participated in the cooperative study and 60 constituents were determined. 50 and 51 components were certified as certified values and 1 and 2 components as reference values respectively for MSCS-1 and MSCS-2,52 constituents were certified as certified values for MSCS-3,4 and 5. The sum of the major and minor components in the five reference materials MSCS-1 -5 is 99.9% ,99.6% ,100.4% ,100.1% and 99.7% ,respectively.

Objective To observe the clinical efficacy and safety of nifedipine controlled-release tablets on the antihypertensive effect of hypertensive patients under high altitude environment. Methods 42 hypertensive inpatients in the 940th hospital (altitude 1500 ) were set to the plain hypertension group, and 42 cases of hypertensive inpatients in Bayi hospital (altitude 3800 m) were set to the plateau hypertension group. Both groups of patients were given nifedipine controlled-release tablets 30 mg daily, taken orally in the morning for 6 consecutive days. Monitor blood pressure and heart rate three times a day to compare the clinical efficacy and occurrence of adverse drug reactions in the two groups. Results After treatment, the total effective rates of the high-altitude hypertension group and the plain hypertension group were 47.62% (20 cases/42 cases) and 76.19% (32 cases/42 cases) respectively with no statistical difference (P<0.05). The adverse drug reactions of the two groups of patients were tachycardia and palpitations. The incidence of total adverse drug reactions in the high-altitude hypertension group and the plain hypertension group were 14.29% and 11.90% respectively with no statistical difference (P>0.05). Conclusion The high-altitude hypoxic environment could affect the antihypertensive effect of nifedipine controlled-release tablets, which could not control the patient's blood pressure effectively in the short term.

Objective To assess the effects of maternal subclinical hypothyroidism (SCH) during the first trimester on neuropsychological development of the offspring by 20-30 months. Methods In this study, 1 761 pregnant women from 10 hospitals with about 8 weeks of gestation were enrolled. Urinary iodine excretion and serum thyrotropin ( TSH ), free thyroxine ( FT4 ), and thyroid peroxidase antibody ( TPOAb ) levels were determined in all subjects. Pregnant women with SCH (TSH≥2.5 mIU/L) were divided into two subgroups using trimester-specific thyroid function reference: group A (2.5 mIU/L≤TSH＜3.93 mIU/L, 18 cases), and group B (TSH ≥3.93 mIU/L, 20 eases). Thirty euthyroid and TPOAb-negative women from the same cohort were selected as controls. Intellectual and motor development score evaluations were performed in the children by 20-30 months of age. Results Children of women with SCH and subgroups A and B had lower mean intelligence scores 6.55,3.39, and 9.40 points compared with those of the control group (P=0. 001, P=0. 125, and P＜0. 001 ); the respective mean motor scores were 6.31,4.35, and 8.07 points being lower than that of the control ( P=0. 003,P=0. 070, and P=0. 001 ). Intelligence scores and motor scores were negatively correlated with TSH levels (r=-0.425, P＜0. 001 and r=-0. 394, P=0. 001 ). Multiple group comparisons revealed that differences of TSH affected intelligence and motor scores (F=9. 277, P＜0. 001 and F=5. 909, P=0. 004). Ordinal logistic regression analysis showed that possibilities for the reduction of filial mental development index ( MDI ) and psychomotor development index ( PDI ) scores in SCH with maternal TSH levels≥3.93 mIU/L were 8.66 and 6.27 times that of controls ( OR = 8.66,95% CI 2.72-27.57, OR =6.27,95% CI 2.03-19.34 ). Conclusion Maternal elevated TSH levels diagnosed by trimester-specific reference during early gestation are independently associated with lowered filial neurodevelopment scores by 20-30 months.

Objective To investigate the effect of melatonin on mice with ischemia-reperfusion via a silent information regulator 1 (SIRT1) reducing mitochondrial oxidative stress mechanism. Methods A transient middle cerebral artery occlusion ( MCAO) cerebral ischemia-reperfusion ( IR) model in mice was established by the suture-occluded method. One hundred and ninety mice were injected with melatonin intraperitoneally or the SIRT1 inhibitor (EX527) intracerebroventricularly,30 dead and model failure mice were excluded. They were divided into IR,melatonin,melatonin +EX527,and EX527 groups (n =40 in each group ) according to the random number table. The cerebral infarct volume was detected by the triphenyltetrazolium chloride (TTC) method,the brain edema was measured by the wet and dry weight method and the neurological deficit scores were measured. Western blot was used to detect SIRT1,Ac-P53, acetylated-nuclear factorκB (Ac-NF-κB),BCl2,Bax proteins in the mitochondria and cytoplasm,as well as the cytochrome C protein expression. A single factor analysis of variance was used for comparison among the groups. Results ( 1 ) There were significant differences in cerebral infarction volume, neurological dysfunction scores and cerebral edema among the four groups ( F values,16. 452,23. 622,and 18. 786, respectively (all P<0. 05). There were significant differences in the expression levels of SIRT1,Ac-P53, Ac-NF-κB,BCl2, and Bax among the four groups ( F values, 2348. 158, 1434. 841, 7042. 563, 14627. 128,and 691. 475,respectively,all P<0. 05). There were significant differences in mitochondrial membrane potential,mitochondrial reactive oxygen species,and complex I activity in mice among the four groups (F value,28. 454,33. 728 and 29. 716,respectively,all P <0. 05). (2) Compared with the IR group,the infarct volume was reduced (32 ± 5 mm3 vs. 57 ± 5 mm3,P<0. 05),neurological deficit scores were decreased (2. 4 ± 0. 3 vs. 3. 5 ± 0. 3,P<0. 05);brain edema was reduced (80. 2 ± 0. 9% vs. 83. 9 ± 1. 2%,P<0. 05);the expression levels of SIRT1 and anti-apoptosis protein BCL2 were increased in the melatonin group (P<0. 05);the expression levels of pro-apoptotic protein BAX and Ac-P53,Ac-NF-κB were reduced ( P <0. 05 );the mitochondrial membrane potential, mitochondrial complex I activity and cytochrome C level were increased (P<0. 05);and the cytoplasmic reactive oxygen species and cytochrome C level were decreased (P < 0. 05). (3) Compared with the melatonin group,cerebral infarction volume were increased (42 ± 5 mm3 vs. 32 ± 5 mm3,P < 0. 05);nerve dysfunction scores were increased(3. 2 ± 0. 3 vs. 2. 4 ± 0. 3,P<0. 05);cerebral edema was aggravated (83. 4 ± 0. 8% vs. 80. 2 ± 0. 9%, P < 0. 05 );the expression levels of SIRT1 and anti-apoptotic protein BCL2 were reduced (P <0. 05);the pro-apoptotic protein BAX,Ac-P53,and Ac-NF-κB expression levels were increased (P<0. 05);the mitochondrial membrane potential and mitochondrial complex I activity and cytochrome C level were decreased (P<0. 05);and the cytoplasmic reactive oxygen species and cytoplasmic cytochrome C level were increased in the melatonin+EX527 group (P<0. 05). Conclusion In ischemic stroke model mice, melatonin plays a neuroprotective role by activating the SIRT1 signaling pathway and reducing oxidative stress injury and cell death in mitochondria,thus plays a role in cerebral protection.

OBJECTIVE: A failed electrocardiography (ECG)-trigger often leads to a long acquisition time (TA) and deterioration in image quality. The purpose of this study was to evaluate and optimize the technique of self-gated (SG) cardiovascular magnetic resonance (CMR) for cardiac late gadolinium enhancement (LGE) imaging of rats with myocardial infarction/reperfusion. MATERIALS AND METHODS: Cardiovascular magnetic resonance images of 10 rats were obtained using SG-LGE or ECG with respiration double-gating (ECG-RESP-gating) method at 7T to compare differences in image interference and TA between the two methods. A variety of flip angles (FA: 10°–80°) and the number of repetitions (NR: 40, 80, 150, and 300) were investigated to determine optimal scan parameters of SG-LGE technique based on image quality score and contrast-to-noise ratio (CNR). RESULTS: Self-gated late gadolinium enhancement allowed successful scan in 10 (100%) rats. However, only 4 (40%) rats were successfully scanned with the ECG-RESP-gating method. TAs with SG-LGE varied depending on NR used (TA: 41, 82, 154, and 307 seconds, corresponding to NR of 40, 80, 150, and 300, respectively). For the ECG-RESP-gating method, the average TA was 220 seconds. For SG-LGE images, CNR (42.5 ± 5.5, 43.5 ± 7.5, 54 ± 9, 59.5 ± 8.5, 56 ± 13, 54 ± 8, and 41 ± 9) and image quality score (1.85 ± 0.75, 2.20 ± 0.83, 2.85 ± 0.37, 3.85 ± 0.52, 2.8 ± 0.51, 2.45 ± 0.76, and 1.95 ± 0.60) were achieved with different FAs (10°, 15°, 20°, 25°, 30°, 35°, and 40°, respectively). Optimal FAs of 20°–30° and NR of 80 were recommended. CONCLUSION: Self-gated technique can improve image quality of LGE without irregular ECG or respiration gating. Therefore, SG-LGE can be used an alternative method of ECG-RESP-gating.
Animals ; Electrocardiography ; Gadolinium* ; Magnetic Resonance Imaging ; Methods ; Myocardial Infarction* ; Rats* ; Respiration

Objective To explore the value of methylation of SDC2 and SFRP2 genes promoter in fecal DNA for colorectal cancer ( CRC) screening. Methods All stool samples were enrolled from Changhai Hospital of Naval Medical University, the Tenth People' s Hospital of Tongji University and the Seventh Medical Center of Chinese People's Liberation Army General Hospital. A total of 500 stool samples collected from March 2018 to December 2018 were allocated to CRC group ( 132 CRCs ) , adenoma group ( 38 advanced adenomas), healthy group (152 healthy individuals), interferential group (178 cases of benign colorectal disease or other non-colorectal tumors) and negative group (330 cases composed of healthy group and interferential group ) . The promoter methylation of fecal SDC2 and SFRP2 genes was detected by methylation-specific PCR (MSP) and compared with single gene methylation and the fecal immunochemical tests ( FIT) to evaluate its sensitivity and specificity. Results The stool sample analysis showed that the sensitivity of combined detection of SDC2 and SFRP2 in CRC group was 97. 73％ ( 129/132 ) , which was significantly higher than those of the single gene SDC2 test [ 70. 45％ ( 93/132) , P=0. 000] , single SFRP2 test [81. 82％ (108/132), P=0. 000] and FIT [69. 70％ (92/132), P=0. 000]. In adenoma group, the sensitivity of combined detection of SDC2 and SFRP2 was 57. 89％ (22/38), which was significantly higher than those of the single gene SDC2 test [ 15. 79％ ( 6/38 ) , P= 0. 000 ] and FIT [ 21. 05％ ( 8/38 ) , P=0. 021] , with no significant difference compared with that of SFRP2 test [ 47. 37％ ( 18/38) , P=0. 358] . In healthy group, the specificity of combined detection of SDC2 and SFRP2 was 98. 68％ (150/152), with no significant difference compared with those of single gene SDC2 test [ 100. 00％( 152/152) , P=0. 156] , single SFRP2 test [98. 68％ (150/152), P=1. 000] or FIT [95. 39％ (145/152), P=0. 091]. Specificities of combined detection of two genes in interferential and negative groups were 90. 45％ ( 161/178) and 94. 24％( 311/330) , which were significantly higher than 73. 03％( 130/178, P=0. 000) and 83. 33％( 275/330, P=0. 000) of FIT, respectively. Conclusion The combined detection test of methylation of SDC2 and SFRP2 is superior to single gene test, whose sensitivity of CRC and aggressive adenoma and specificity of distinguishing benign and malignant lesions are higher than FIT, which has potential application value.

Objective To investigate the epidemiological characteristics of non-toxic goiter and non-toxic thyroid nodules in the regions with different iodine intakes and the factors influencing the occurrence, development and outcome of goiter and thyroid nodules. Methods 3 385 subjects, who had taken part in the previous survey in 1999 with the ultrasonic examination of thyroid, were composed of individuals in Panshan with chronic mild iodine deficiency,in Zhangwu with more than adequate iodine "after iodine supplementation and in Huanghua with excessive iodine. These 3 groups of subjects were followed up in 2004. Results (1) The cumulative incidences of diffuse goiter in Panshan ,Zhangwu and Huanghua were 7.1% ,4.4% and 6.9% ,respectively ,being the lowest in Zhangwu (P<0.01) and those of nodular goiter were 5.0% ,2. 4% and 0.8%, respectively, being the highest in Panshan (P<0.01). (2) The incidences of single nodule were 4.0% ,5.7% and 5.6%, respectively, and those of multiple nodules 0.4%, 1.2% and 1.0%, respectively. (3)The result of logistic analysis showed that iodine deficiency,iodine excess and positive thyroid autoantibodies (TAA) were the independent risk factors for the occurrence of goiter. (4)In Zhangwu ,the incidence of non-toxic goiter in the group with positive TAA was higher than that in the group with negative TAA(P<0.01) ,while there were no such differences in Panshan and Huanghua. (5)In these three regions, the rates of positive TAA in the individuals with diffuse non-toxic goiter were higher than those in the healthy subjects (P<0.05). And in Huanghua,the rate of positive TAA in subjects with non-toxic nodular goiter was also higher than that in the healthy individuals (P<0.05). Conclusion Iodine deficiency and iodine excess may both induce the raising incidence of goiter. Nodular goiter is prevalent in iodine deficient district and diffuse goiter is the predominant form in places with iodine excess. Thyroid autoimmunity is associated with occurrence and maintenance of goiter, and this phenomenon is more obvious in the community with previous iodine deficiency followed then by treatment with more than adequate iodine.

Objective To clarify the effect of iodine intake on serum thyroglobulin (Tg). Methods A 5-year prospective study was conducted in the 3 different iodine intake areas in China [Panshan (miht deficiency) ,Zhangwu (more than adequate) and Huanghua (excess)]. A total of 3 099 people with normal serum levels of Tg in 1999 were followed and 2 448 of these participants were feasible to be observed in 2004 and included in the present study. The serum levels of Tg, thyraglobulin antibody(TgAb), thyroid peroxidase antibody(TPOAb) and TSH, thyroid volume, family and personal histories of thyroid diseases were measured and inquried. The general linear model (GLM) was used to explore the determinants of Tg. Results Among the study population at baseline, serum Tg were significantly different in three areas [7.5 (4.4-13. 1) μg/L at Panshan, 6.8 (3.6-11.2)μg/L at Huanghua, 5.9 (3.2-10.7) μg/L at Zhangwu, P<0.01]. They were associated with age, sex and the rate of positive TgAb, abnormal thyroid volume, abnormal TSH and positive personal history of thyroid diseases, in order to control the effects of confounding factors, the data from 1856 subjects with thyroid-related indexes all in normal range and without personal history of thyroid diseases were analyzed to clarify the effect of iodine intake on Tg. The serum Tg among three areas were significantly different in both 1999 and 2004, they were all increased in 5 years with significant augment (△ Tg) among the three areas[3.1 (-0.2-8.0) μg/L at Panshan, 3.5 (0.5-9.0)μg/L at Huanghua vs 2. 5(0.3-6.1) μg/L at Zhangwu,P<0.01]. The GLM analysis revealed that age, Tg and TSH levels at baseline were the determinants of △Tg in addition to iodine intake. Conclusion Iodine intake is a dominant determinant of serum Tg. Age and TSH should also be considered while indicating iodine intake by serum Tg.