Toward understanding early Earth evolution: Prescription for approach from terrestrial noble gas and light element records in lunar soils

Because of the almost total lack of geological record on the Earth''s surface before 4 billion years ago, the history of the Earth during this period is still enigmatic. Here we describe a practical approach to tackle the formidable problems caused by this lack. We propose that examinations of lunar soils for light elements such as He, N, O, Ne, and Ar would shed a new light on this dark age in the Earth''s history and resolve three of the most fundamental questions in earth science: the onset time of the geomagnetic field, the appearance of an oxygen atmosphere, and the secular variation of an Earth–Moon dynamical system.     

硝酸稀土促进布鲁氏菌生长试验

我们用硝酸稀土培养基做了猪种、羊种布鲁氏菌促进生长试验,结果表明,猪种布鲁氏菌菌体细胞每分裂一次其时间可提前22分钟,羊种布鲁氏菌则可提前12.7～17.5分钟,说明硝酸稀土有促进布鲁氏菌生长作用。     

稀土氧化物着色牙色四方多晶氧化锆陶瓷的机械性能研究

目的探讨添加微量稀土氧化物对牙色四方多晶氧化锆（Y-TZP）陶瓷的机械性能的影响。方法以稀土氧化物（Pr6O11、CeO2、Er2O3）和过渡元素氧化物（MnO2）为着色剂,采用粉体掺杂方法在Y-TZP粉体中添加不同质量分数的着色剂,制备出6组牙色Y-TZP,测试其机械性能（包括弯曲强度、维氏硬度、断裂韧性）,并通过扫描电子显微镜观察各组陶瓷烧结体断裂面的显微结构,分析其断裂模式。结果6组牙色Y-TZP的弯曲强度为（792±20）～（960±17）MPa,断裂韧性为（4.72±0.31）～（5.64±0.38）MPam1/2,维氏硬度为（1 332±19）～（1 380±17）MPa;显微结构显示6组陶瓷均呈致密的多晶结构,断裂模式为混合型断裂。结论以稀土氧化物作为着色剂制备的Y-TZP具有较好的断裂韧性和维氏硬度,可满足口腔临床的应用要求。     

Sustainability of rare earth elements chain: from production to food – a review

Rare earth elements (REE) are a group of chemical elements that include lanthanoids (lanthanum to lutetium), scandium and yttrium. In the last decades, the REE demand in the industry and other areas has increased significantly. In general, REE have shown low concentrations in soils, plants, water and atmosphere, but they may accumulate in such environments due to anthropogenic inputs. In areas where there is REE contamination, the slow accumulation of these elements in the environment could become problematic. Many studies have shown environmental areas contaminated with REE and their toxic effects. Thus, it is important to review, in order to improve the current understanding of these elements in the environment, showing the effects of REE exposure in mining, soil, water, plants and food. Besides, there are few suppliers and a limited quantity of these elements in the world. This paper suggests options to improve the sustainability management of REE chain.     

Effect of Rare Earth Metals (Y,La) and Refractory Metals (Mo,Ta, Re) to Improve the Mechanical Properties of W–Ni–Fe Alloy—A Review

Tungsten heavy alloys are two-phase metal matrix composites that include W–Ni–Fe and W–Ni–Cu. The significant feature of these alloys is their ability to acquire both strength and ductility. In order to improve the mechanical properties of the basic alloy and to limit or avoid the need for post-processing techniques, other elements are doped with the alloy and performance studies are carried out. This work focuses on the developments through the years in improving the performance of the classical tungsten heavy alloy of W–Ni–Fe through doping of other elements. The influence of the percentage addition of rare earth elements of yttrium, lanthanum, and their oxides and refractory metals such as rhenium, tantalum, and molybdenum on the mechanical properties of the heavy alloy is critically analyzed. Based on the microstructural and property evaluation, the effects of adding the elements at various proportions are discussed. The addition of molybdenum and rhenium to the heavy alloy gives good strength and ductility. The oxides of yttrium, when added in a small quantity, help to reduce the tungsten’s grain size and obtain good tensile and compressive strengths at high temperatures.     

Influence of Dissolving Fe–Nb–B–Dy Alloys in Zirconium on Phase Structure,Microstructure and Magnetic Properties

This paper refers to the structural and magnetic properties of [(Fe₈₀Nb₆B₁₄)_0.88Dy_0.12]_1−xZr_x (x = 0; 0.01; 0.02; 0.05; 0.1; 0.2; 0.3; 0.5) alloys obtained by the vacuum mold suction casting method. The analysis of the phase contribution indicated a change in the compositions of the alloys. For x < 0.05, occurrence of the dominant Dy₂Fe₁₄B phase was observed, while a further increase in the Zr content led to the increasing contribution of the Fe–Zr compounds and, simultaneously, separation of crystalline Dy. The dilution of (Fe₈₀Nb₆B₁₄)_0.88Dy_0.12 in Zr strongly influenced the magnetization processes of the examined alloys. Generally, with the increasing x parameter, we observed a decrease in coercivity; however, the unexpected increase in magnetic saturation and remanence for x = 0.2 and x = 0.3 was shown and discussed.     

Enhanced dual contrast agent,Co-doped NaYF4:Yb,Tm nanorods,for near infrared-to-near infrared upconversion luminescence and magnetic resonance imaging

Dual-modality imaging with magnetic resonance (MR) and upconversion luminescence (UCL) is a promising technique for molecular imaging in biomedical research. Multifunctional lanthanide-based nanoparticles have been widely investigated as agents for contrast enhanced MR and fluorescence imaging. However, the use of rare earth fluoride nanoparticles for dual-modality imaging of T2-weighted MR and UCL is rarely reported. We find that NaYF₄:Yb³⁺,Tm³⁺,Co²⁺ (MUC) nanorods can be applied as a high-performance dual contrast agent for both T2-weighted MR and UCL dual-modality imaging. After modification with 6-O-carboxymethyl chitosan (OCC), MUC nanorods can be endocytosed by cells without showing signs of cytotoxicity. High-quality UCL images of living cells incubated with MUC-OCC nanorods were acquired on a near-infrared (NIR) confocal microscopy under the excitation at 980 nm. Moreover, MUC-OCC nanorods display high transverse (r2) relaxivities in vitro. The application of low-dose MUC-OCC nanorods for NIR-to-NIR UCL and MR dual-modality in vivo imaging was also carried out successfully. In addition, the toxicity of MUC-OCC nanorods was evaluated by MTT assay, serological tests and histological analysis of visceral organs.     

从《周易》坤卦浅论脾脏功能

从"脾"之造字,可得人体之"脾"与自然界之"土"关系密切。将中医脾脏的功能(承载、化生、运达、收纳)与《周易》坤土之卦的功能(厚德载物、万物滋生、行地无疆、辟户阖户)相比较,两者皆可一一对应,以此作为佐证,可以看出中医确实是植根于中国传统文化。同时中医确为"天人合一"之医学,其大而无外,天地万物皆在其中,小而无内,一人之身无有其外,皆可取类比象。中医之整体观,包罗万象,宇宙自然皆在其中,并非割裂人体而谈某脏器功能。脾脏"厚德载物""万物滋生""行地无疆""辟户阖户"这四大功能突出"脾脏"与"土地"的对应关系,此四种功能在人体内"如环无端,不分主次",不可割裂。将中医所讲人体脏器的功能,与自然界中所对应事物的功能取类比象,将抽象的脏腑功能具体化,方便理解记忆的同时,更能使中医的核心理论得到体现。     

“益火补土”法应用数据分析

收集清代以前各类医书中用＂益火补土＂法治疗的医案201例,运用频数统计和聚类统计方法,对其性别、年龄、主治病种症状、所用方剂、药味药量等进行分析,结果示：＂益火补土＂法以泄泻、腹胀、腹痛、纳差、痞满、呕吐、浮肿、疲倦乏力、下痢脓血、面色萎黄、脉虚细微、舌淡为主证,在用药上补肾药与治脾药总体比例为1.17：1,补肾药用量略重于治脾药。     

三氯化镧对CBRH-7919细胞CyclinD1和CDK4蛋白表达的影响

背景与目的:研究三氯化镧(LaCl3)对大鼠肝癌细胞CyclinD1和CDK4蛋白表达的影响.材料与方法:采用体外培养大鼠肝癌细胞株CBRH-7919,分别加入0.01、0.10、1.00 mmol/L LaCl3培养1、3、5 d后观察CBRH-7919细胞生长变化;运用流式细胞术、MTF实验和免疫细胞化学检测与G1期调控有关的CyclinD1和CDK4的变化情况,以培养液中不加LaCl3体外培养CBRH-7919作为对照.结果:0.10、1.00 mmol/L LaCl3组培养后3、5 d对细胞的生长均具有抑制作用,与对照组比差异具有统计学意义(P＜0.01);G0/G1期细胞百分数均有显著性增加,与对照组比差异均具有统计学意义(P＜0.01);CyclinD1、CDK4阳性表达均显著减弱,与对照组比差异具有统计学意义(P＜0.01).结论:LaCl3可通过下调CyclinD1和CDK4,使肿瘤细胞从G1期进入S期受阻,从而抑制CBRH-7919细胞的生长.