Taipingite-(Ce),(Ce73+,Ca2)∑9Mg(SiO4)3[SiO3(OH)]4F3,a new mineral from the Taipingzhen REE deposit,North Qinling Orogen,central China

A new cerite group mineral species,taipingite-(Ce),ideally(Ce7^3+,Ca2)∑9Mg(SiO4)3[SiO3(OH)]4 F3,has been found in the Taipingzhen rare earth element(REE)deposit in the North Qinling Orogen(NQO),Central China.It forms subhedral grains(up to approximately 100 μm×200 μm)commonly intergrown with the REE mineral assemblages and is closely associated with allanite-(Ce),gatelite-(Ce),tornebohmite-(Ce),fluocerite-(Ce),fluocerite-(La),fluorite,bastnasite-(Ce),parisite-(Ce)and calcite.Taipingite-(Ce)is light red to pinkish brown under a binocular microscope and pale brown to colorless in thin section,and it is translucent to transparent with a grayish-white streak and vitreous luster.This mineral is brittle with conchoidal fracture;has a Mohs hardness value of approximately 51/2 and exhibits no cleavage twinning or parting.The calculated density is 4.900(5)g/cm3.Optically,taipingite-(Ce)is uniaxial(+),withω=1.808(5),ε=1.812(7),c=ε,and a=b=ω.Furthermore,this mineral is insoluble in HCl,HNO3 and H2 SO4.Electron microprobe analysis demonstrated that the sample was relatively pure,yielding the empirical formula(with calculated H2 O):(Ce4.02La1.64Nd1.49Pr0.41Sm0.10Gd0.02Ho0.02Tm0.01Lu0.02Y0.03Ca0.66Mg0.05Th(0.01-0.51∑9(Mg0.75Fe0.253+)∑1(SiO4)3{[SiO3(OH)]3.98[PO3(OH)]0.02}∑4(F1.81OH1.17Cl0.02∑3.Taipingite-(Ce)is trigonal and exhibits space group symmetry R3 c with unit cell parameters a=10.7246(3)Å,c=37.9528(14)Å,V=3780.39(20)Å3 and Z=6.The strongest eight lines in the X-ray diffraction pattern are[d in A(I)(hkl)]:4.518(50)(202),3.455(95)(122),3.297(85)(214),3.098(35)(300),2.941(100)(02,10),2.683(65)(220),1.945(40)(238)and 1.754(40)(30,18).The crystal structure has been refined to a R1 factor of 0.025,calculated for the 2312 unique observed reflections(Fo≥4σ).The mineral is named after its discovery locality and is characterized as the F-dominant analogue of cerite-(Ce).

Excess Diffusion of a Driven Colloidal Particle in a Convection Array

We numerically investigate the transport of a passive colloidal particle in a periodic array of planar counterrotating convection rolls,at high Peclet numbers.It is shown that an external bias,oriented parallel to the array,produces a huge excess diffusion peak,in cases where bias and advection drag become comparable.This effect is not restricted to one-dimensional convection geometries,and occurs independently of the array’s boundary conditions.

Pathophysiological mechanisms and therapeutic approaches in obstructive sleep apnea syndrome

Obstructive sleep apnea syndrome(OSAS)is a common breathing disorder in sleep in which the airways narrow or collapse during sleep,causing obstructive sleep apnea.The prevalence of OSAS continues to rise worldwide,particularly in middle-aged and elderly individuals.The mechanism of upper airway collapse is incompletely understood but is associated with several factors,including obesity,craniofacial changes,altered muscle function in the upper airway,pharyngeal neuropathy,and fluid shifts to the neck.The main characteristics of OSAS are recurrent pauses in respiration,which lead to intermittent hypoxia(IH)and hypercapnia,accompanied by blood oxygen desaturation and arousal during sleep,which sharply increases the risk of several diseases.This paper first briefly describes the epidemiology,incidence,and pathophysiological mechanisms of OSAS.Next,the alterations in relevant signaling pathways induced by IH are systematically reviewed and discussed.For example,IH can induce gut microbiota(GM)dysbiosis,impair the intestinal barrier,and alter intestinal metabolites.These mechanisms ultimately lead to secondary oxidative stress,systemic inflammation,and sympathetic activation.We then summarize the effects of IH on disease pathogenesis,including cardiocerebrovascular disorders,neurological disorders,metabolic diseases,cancer,reproductive disorders,and COVID-19.Finally,different therapeutic strategies for OSAS caused by different causes are proposed.Multidisciplinary approaches and shared decision-making are necessary for the successful treatment of OSAS in the future,but more randomized controlled trials are needed for further evaluation to define what treatments are best for specific OSAS patients.

A unified global genotyping framework of dengue virus serotype-1 for a stratified coordinated surveillance strategy of dengue epidemics

Background: Dengue is the fastest spreading arboviral disease, posing great challenges on global public health. A reproduceable and comparable global genotyping framework for contextualizing spatiotemporal epidemiological data of dengue virus (DENV) is essential for research studies and collaborative surveillance.Methods: Targeting DENV-1 spreading prominently in recent decades, by reconciling all qualified complete E gene sequences of 5003 DENV-1 strains with epidemiological information from 78 epidemic countries/areas ranging from 1944 to 2018, we established and characterized a unified global high-resolution genotyping framework using phylogenetics, population genetics, phylogeography, and phylodynamics.Results: The defined framework was discriminated with three hierarchical layers of genotype, subgenotype and clade with respective mean pairwise distances 2-6%, 0.8-2%, and ≤ 0.8%. The global epidemic patterns of DENV-1 showed strong geographic constraints representing stratified spatial-genetic epidemic pairs of Continent-Genotype, Region-Subgenotype and Nation-Clade, thereby identifying 12 epidemic regions which prospectively facilitates the region-based coordination. The increasing cross-transmission trends were also demonstrated. The traditional endemic countries such as Thailand, Vietnam and Indonesia displayed as persisting dominant source centers, while the emerging epidemic countries such as China, Australia, and the USA, where dengue outbreaks were frequently triggered by importation, showed a growing trend of DENV-1 diffusion. The probably hidden epidemics were found especially in Africa and India. Then, our framework can be utilized in an accurate stratified coordinated surveillance based on the defined viral population compositions. Thereby it is prospectively valuable for further hampering the ongoing transition process of epidemic to endemic, addressing the issue of inadequate monitoring, and warning us to be concerned about the cross-national, cross-regional, and cross-continental diffusions of dengue, which can potentially trigger large epidemics.Conclusions: The framework and its utilization in quantitatively assessing DENV-1 epidemics has laid a foundation and re-unveiled the urgency for establishing a stratified coordinated surveillance platform for blocking global spreading of dengue. This framework is also expected to bridge classical DENV-1 genotyping with genomic epidemiology and risk modeling. We will promote it to the public and update it periodically.

比率成像纳米探针在内源性小分子成像中的应用

内源性信号小分子在生命活动过程中起着重要的作用,其浓度的变化和分布的异常与多种生理病理状态相关.设计可实时检测其在体内动态变化的成像体系对疾病诊断、病因探讨及细胞信号转导机制的研究至关重要.传统的检测方式多采用单一通道成像,干扰因素较多难以精确定量.近年来,比率成像纳米探针借助其独特的优势被广泛应用于生物医学领域.本文简要综述了响应于氢离子、活性氧/氮物种(ROS/RNS)和气体信号分子的比率成像纳米探针的设计原理及生物学应用.

Non-Gaussian normal diffusion in low dimensional systems

Brownian particles suspended in disordered crowded environments often exhibit non-Gaussian normal diffusion(NGND),whereby their displacements grow with mean square proportional to the observation time and non-Gaussian statistics.Their distributions appear to decay almost exponentially according to“universal”laws largely insensitive to the observation time.This effect is generically attributed to slow environmental fluctuations,which perturb the local configuration of the suspension medium.To investigate the microscopic mechanisms responsible for the NGND phenomenon,we study Brownian diffusion in low dimensional systems,like the free diffusion of ellipsoidal and active particles,the diffusion of colloidal particles in fluctuating corrugated channels and Brownian motion in arrays of planar convective rolls.NGND appears to be a transient effect related to the time modulation of the instantaneous particle’s diffusivity,which can occur even under equilibrium conditions.Consequently,we propose to generalize the definition of NGND to include transient displacement distributions which vary continuously with the observation time.To this purpose,we provide a heuristic one-parameter function,which fits all time-dependent transient displacement distributions corresponding to the same diffusion constant.Moreover,we reveal the existence of low dimensional systems where the NGND distributions are not leptokurtic(fat exponential tails),as often reported in the literature,but platykurtic(thin sub-Gaussian tails),i.e.,with negative excess kurtosis.The actual nature of the NGND transients is related to the specific microscopic dynamics of the diffusing particle.

A magnetism/laser-auxiliary cascaded drug delivery to pulmonary carcinoma

Although high-efficiency targeted delivery is investigated for years, the efficiency of tumor targeting seems still a hard core to smash. To overcome this problem, we design a three-step delivery strategy based on streptavidin-biotin interaction with the help of c(RGDfK), magnetic fields and lasers.The ultrasmall superparamagnetic iron oxide nanoparticles(USIONPs) modified with c(RGDfK) and biotin are delivered at step 1, followed by streptavidin and the doxorubicin(Dox) loaded nanosystems conjugated with biotin at steps 2 and 3, respectively. The delivery systems were proved to be efficient on A549 cells. The co-localization of signal for each step revealed the targeting mechanism. The external magnetic field could further amplify the endocytosis of USPIONs based on c(RGDfK), and magnify the uptake distinctions among different test groups. Based on photoacoustic imaging, laser-heating treatment could enhance the permeability of tumor venous blood vessels and change the insufficient blood flow in cancer. Then, it was noticed in vivo that only three-step delivery with laser-heating and magnetic fields realized the highest tumor distribution of nanosystem. Finally, the magnetism/laser-auxiliary cascaded delivery exhibited the best antitumor efficacy. Generally, this study demonstrated the necessity of combining physical, biological and chemical means of targeting.