A microwave digestion system was preparation for the digestion of the sediment samples of 16 stations in the Southe mid_Atlantic ridge by using HNO3_H2 O2_HF as the digestion reagent. The rare earth elements ( RE ) in sediments were determined by inductively coupled plasma mass spectrometry, and distribution characteristics of rare earth elements were studied. The microwave digestion_ICP_MS method was used for the determination of rare earth elements with a good linear relationship ( r=0 . 9997-1 . 0000 ) for each element. The detection limit reached ng/L level, the relative standard deviation ( RSD, n=3 ) was less than 3% and the relative error was 6%. The total amount of rare earth elements (ΣRE) in sediment samples from 16 stations varied in the range of 37. 25-134. 77 μg/g, the ratio range of light RE/heavy RE ( LRE/HRE) was 0 . 61-1 . 70 , the average value was 1 . 27 , and the enrichment of light rare earth elements in sediments was slightly obvious. The RE distribution patterns were basically the same in each station with obvious fractionation between LRE and HRE. The RE distribution patterns were also similar in sediments from different sources with slightly difference between terrestrial and marine sediments. The δEu and δCe in the sediments had negative anomaly which showed that the rare earth elements in sediments came from the seawater. This study first analyzed the content and distribution of rare earth elements in the southern Atlantic, providing data and technical support for further study of the distribution of rare earth elements in the Atlantic.

Objective To construct Fas-targeting siRNA-expressing plasmid, and explore the significance of Fas inhibition in the treatment of acute aplastic anemia. Methods U6 promoter cassette and siFas sequence were obtained by PCR method, and cloned into modified pcDNA3.1 to produce plasmid pU6-siFas, which was transfected into P815 cells with limpofectin 2000, and then Fas expression was detected by immunohistochemistry. Results The plasmid pU6-siFas could efficiently reduce the expression of Fas and confer G-418 resistance in P815 cells. Conclusion The successful construction of the siRNA expressing plasmid will facilitate the application of RNA interference technique, and lay foundation for further studies of the therapeutic effect of Fas inhibition on acute aplastic anemia.

Objective To explore the developmental characteristics of white matter volume in autism spectrum disorder (ASD) children longitudinal.Methods From May 2011 to September 2014,37 ASD children (ASD group)and 27 developmental delays (DD) children (control group) were treated at the Child Mental Health Research Center,Nanjing Brian Hospital Affiliated of Nanjing Medical University,and the children whose age,gender and developmental quotient matched with the ASD children were scanned by structure magnetic resonance imaging (sMRI) at the age of 2-3 years old and 4-5 years old respectively.Region of interest (ROI) technology was adopted to investigate the change of the cerebrum white and the sub-lobes structure white matter volume with time.Then the correlation between clinical symptoms and brain white matter volume changes was analyzed.Results Among the 2-3 years old,compared with the control group,the white matter volume of the total brain[(383 521.84 ±6 427.57) mm3 vs.(364 014.06 ±6 856.97) mm3],the left cerebral hemisphere [(191 609.35 ± 3 206.60) mm3 vs.(181 695.89 ± 3 389.54)mm3],temporal lobe [(41 860.49 ±816.38) mm3 vs.(39 444.18 ± 834.85) mm3] and the right temporal lobe [(21 312.79 ± 414.07) mm3 vs.(20 084.22 ± 412.13) mm3] were significantly larger in the ASD group,and the differences were statistically significant (all P ＜ 0.05).With the analysis of covariance with age or the total brain volume as the covariate,the differences disappeared(all P ＞ 0.05).Among the 4-5 years old,compared with the control group,the white matter volumes of the total brain[(417 651.42 ± 6 443.86) mm3 vs.(394 317.27 ± 6 404.86)mm3],left cerebral hemisphere [(208 714.16 ±3 214.61) mm3 vs.(197 192.82 ±3 262.02) mm3],right cerebral hemisphere [(208937.26±3242.09) mm3 vs.(7 124.45 ±3 193.13) mm3],frontal lobe [(107 107.46±1 681.99) mm3 vs.(100 326.19 ± 1 883.24) mm3],left frontal lobe [(54 569.63 ± 846.85) mm3 vs.(51 177.25 ±979.09) mm3],right frontal lobe [(52 537.83 ± 841.99) mm3 vs.(49 148.94 ±928.31) mm3],temporal lobe [(45 189.75 ± 833.29) mm3 vs.(42 487.73 ± 786.27) mm3],left temporal lobe [(22 204.21 ±411.77) mm3 vs.(20 922.90 ± 418.46) mm3],and right temporal lobe [(22 985.54 ± 426.93) mm3 vs.(21 564.83 ± 378.78) mm3]were significantly larger in the ASD group,and the differences were statistically significant (all P ＜ 0.05).With the analysis of covariance with age as the covariate,the differences still existed (all P ＜ 0.05).With the analysis of covariance with the total brain volume as the covariate,the differences disappeared (all P ＞ 0.05).For longitudinal analysis,there was a significant difference in the white matter volume between the whole brain,left cerebral hemisphere,right cerebral hemisphere,frontal lobe,left frontal lobe,fight frontal lobe,temporal lobe,left temporal lobe,right temporal lobe and the differences were statistically significant (F =5.521,5.533,5.459,5.830,5.800,5.723,4.857,4.418,5.159,all P ＜0.05).There was a positive correlation between the changes of the volume of whole brain,the white matter volume in the whole brain,bilateral cerebral hemisphere,frontal lobe,parietal lobe,right parietal lobe and Childhood Autism Rating Scale (r =0.367,0.343,0.321,0.349,0.296,0.308,0.351,all P ＜ 0.05).Conclusions Among the 2-3 years old,the white matter volume of the brain regions have been increased significantly in ASD.Among the 4-5 years old,the increase of the white matter volume of the brain regions implicated more widely which mainly concentrated in the frontal and temporal lobe in ASD.The severity of the clinical symptoms of ASD may be associated with the white matter volume of the total brain,bilateral cerebral hemisphere,frontal lobe,parietal lobe and right parietal lobe.

In order to understand the actual needs and influencing factors of cancer patients to participate in medical decision-making, 29 cancer patients were selected for semi-structured interviews by purpose sampling from September 2020 to February 2021, and the data were analyzed by substantive coding step by step according to interview method. The results showed that the quality of patient-clinician interaction was an important factor influencing the decision quality. The elements for cancer patients to participate in medical decision-making include: patients’ disease knowledge, awareness of choice, communication duration, support from family members and doctors, and mutual trust between doctors and patients. Medical staff should respect patients’ preference to participate in medical decision-making, break the medical-centered system arrangement, help patients obtain services matching their preferences for participating in decision-making, and achieve a pattern that is beneficial to both patients and the medical system.

Heme/metabolism* ; Cryoelectron Microscopy ; Membrane Transport Proteins ; Escherichia coli Proteins/metabolism*