37 research outputs found

    A Case of Congenital Isolated Adrenocorticotropic Hormone Deficiency Caused by Two Novel Mutations in the TBX19 Gene

    Get PDF
    Congenital isolated adrenocorticotropic hormone (ACTH) deficiency (CIAD) is a rare disorder which can result in 20% mortality in the neonatal period if misdiagnosed. A 2 years and 7 months old boy was hospitalized many times because of recurrent hypoglycemia. On initial physical examination, the patient showed special appearance and indications of fast growth (≥P97). Laboratory investigations revealed low levels of ACTH and cortisol in his plasma. Except thyroid-stimulating hormone, the anterior pituitary hormone concentrations were normal. Molecular data showed compound heterozygosity for two novel mutations in the TBX19 gene (encoding the transcription factor T-Box 19). Mutation c.205C>T was inherited from mother and the fragment deletion (from g.168,247,374 to g.168,278,264) was from father. Hydrocortisone replacement therapy was effective. We reported two novel TBX19 mutations, expanding the mutation spectrum of this disorder, in a CIAD patient who presented with special appearance, signs of fast growth, and thyroid-stimulating hormone derangement. In addition, for avoiding misdiagnosis, criterion for ACTH and cortisol detection of CIAD should be established

    Exosome delivery to the testes for dmrt1 suppression: a powerful tool for sex-determining gene studies

    Get PDF
    Exosomes are endosome-derived extracellular vesicles about 100 nm in diameter. They are emerging as prom ising delivery platforms due to their advantages in biocompatibility and engineerability. However, research into and applications for engineered exosomes are still limited to a few areas of medicine in mammals. Here, we expanded the scope of their applications to sex-determining gene studies in early vertebrates. An integrated strategy for constructing the exosome-based delivery system was developed for efficient regulation of dmrt1, which is one of the most widely used sex-determining genes in metazoans. By combining classical methods in molecular biology and the latest technology in bioinformatics, isomiR-124a was identified as a dmrt1 inhibitor and was loaded into exosomes and a testis-targeting peptide was used to modify exosomal surface for efficient delivery. Results showed that isomiR-124a was efficiently delivered to the testes by engineered exosomes and revealed that dmrt1 played important roles in maintaining the regular structure and function of testis in juvenile fish. This is the first de novo development of an exosome-based delivery system applied in the study of sex determining gene, which indicates an attractive prospect for the future applications of engineered exosomes in exploring more extensive biological conundrums.info:eu-repo/semantics/publishedVersio

    Patch-level based vegetation change and environmental drivers in Tarim River drainage area of West China

    Get PDF
    Information on vegetation-related land cover change and the principle drivers is critical for environmental management and assessment of desertification processes in arid environments. In this study, we investigated patch-level based changes in vegetation and other major land cover types in lower Tarim River drainage area in Xinjiang, West China, and examined the impacts of environmental factors on those changes. Patterns of land cover change were analyzed for the time sequence of 1987-1999-2004 based on satellite-derived land classification maps, and their relationships with environmental factors were determined using Redundancy Analysis (RDA). Environmental variables used in the analysis included altitude, slope, aspect, patch shape index (fractal dimension), patch area, distance to water body, distance to settlements, and distance to main roads. We found that during the study period, 26% of the land experienced cover changes, much of which were the types from the natural riparian and upland vegetation to other land covers. The natural riparian and upland vegetation patches were transformed mostly to desert and some to farmlands, indicating expanding desertification processes of the region. A significant fraction of the natural riparian and upland vegetation experienced a phase of alkalinity before becoming desert, suggesting that drought is not the exclusive environmental driver of desertification in the study area. Overall, only a small proportion of the variance in vegetation-related land cover change is explainable by environmental variables included in this study, especially during 1987-1999, indicating that patch-level based vegetation change in this region is partly attributable to environmental perturbations. The apparent transformation from the natural riparian and upland vegetation to desert indicates an on-going process of desertification in the region

    Investigation on Wire Electrochemical Discharge Micro-Machining

    No full text
    With the development of MEMS, the machining demand and requirements for difficult-to-machine metal micro parts are getting higher. Microelectric discharge machining is an effective method to process difficult-to-machine metals. However, the recast layer caused by high temperatures in microelectric discharge machining affects the properties of machined materials. Here, we propose the wire electrochemical discharge micro-machining (WECDMM) and develop a new electrolyte system, which removes the recast layer. In this study, the mechanism of WECDMM was elucidated. The electrolyte was optimized through a comparison experiment, and NaNO3-glycol solution was determined as the best electrolyte. The influences of key process parameters including the conductivity of the electrolyte, pulse voltage, pulse-on time and wire feed rate were analyzed on the slit width, standard deviation, the radius of fillet at the entrance of the slit and roughness. Typical microstructures were machined, which verified the machining ability of WECDMM

    Effect of Excitation Beam Divergenceon the Goos–HänchenShift Enhanced byBloch Surface Waves

    No full text
    The Goos–Hänchen (GH) shift is simulated and experimentally studied when the Bloch surface wave is excited in the forbidden band of a one-dimensional photonic band-gap structure for an excitation beam with different divergence. By changing the beam waist radius, a correspondingly changed Goos–Hänchen shift curve can be observed, where with a larger waist radius and the corresponding less divergence of the excitation beam, a greater GH shift that is closer to the Artmann estimation is obtained. The experimental demonstration of this phenomenon agrees well with the theoretical simulation

    The Impacts of Land Use Spatial Form Changes on Carbon Emissions in Qinghai–Tibet Plateau from 2000 to 2020: A Case Study of the Lhasa Metropolitan Area

    No full text
    The ecological contribution of the Qinghai–Tibet Plateau has received considerable attention as a result of the increased focus on global climate change and the continuous growth of carbon emissions in all countries. In this study, we proposed a method and measured the carbon emissions from land use in the Lhasa metropolitan area from 2000 to 2020, based on image interpretation data, by exploiting corrected carbon emission factors in different land types from the Qinghai–Tibet Plateau. We studied the impact of construction land form on carbon emissions using the spatial lag model (SLM) and the spatial error model (SEM), and the results show that the Lhasa metropolitan area’s carbon emissions showed an overall increasing trend from 2000 to 2020, with the characteristics of “slow acceleration–slight deceleration–acceleration”, with a deceleration period from 2005 to 2015. As a result, the construction land has a relatively low capacity, but it constitutes about 90% of all emissions; moreover, carbon emissions from cultivated land cover about 9%. The rate of spatial expansion of carbon emissions from land use is significantly slower in the Lhasa metropolitan area, yet the spatial expansion of carbon emissions has a clear direction and increases in the north and west of Lhasa. The carbon emissions from land use in the Lhasa metropolitan area is characterized by “one core, many points, and multiple belts” in spatial distribution. The changing of spatial forms of construction land has a significant impact on carbon emissions. Finally, we depicted the impact logic of land use pattern on carbon emissions and provided policy and management recommendations that were both feasible and reasonable

    Polarimetric-Phase-Enhanced Intensity Interrogation Scheme for Surface Wave Optical Sensors with Low Optical Loss

    No full text
    A polarimetric-phase-enhanced intensity interrogation scheme leveraging the polarization-dependent sharp phase change induced by the surface wave excitation at a low-optical-loss sensor’s surface is proposed and experimentally demonstrated. Based on a simple setup with no moving parts during interrogation, a polarimetric-phase-enhanced intensity can be obtained by subtracting the reflected intensities of two beam polarization states. Our results show a ~4-fold sensitivity increase compared to traditional intensity detection schemes for similar sensors. As novel surface wave optical sensors are designed and engineered with optimized phase responses, this scheme offers a low-complexity solution for such devices instead of traditional phase interrogation schemes

    Bloch-Surface-Polariton-Based Hybrid Nanowire Structure for Subwavelength, Low-Loss Waveguiding

    No full text
    Surface plasmon polaritons (SPPs) have been thoroughly studied in the past decades for not only sensing but also waveguiding applications. Various plasmonic device structures have been explored due to their ability to confine their optical mode to the subwavelength level. However, with the existence of metal, the large ohmic loss limits the propagation distance of the SPP and thus the scalability of such devices. Therefore, different hybrid waveguides have been proposed to overcome this shortcoming. Through fine tuning of the coupling between the SPP and a conventional waveguide mode, a hybrid mode could be excited with decent mode confinement and extended propagation distance. As an effective alternative of SPP, Bloch surface waves have been re-investigated more recently for their unique advantages. As is supported in all-dielectric structures, the optical loss for the Bloch surface wave is much lower, which stands for a much longer propagating distance. Yet, the confinement of the Bloch surface wave due to the reflections and refractions in the multilayer structure is not as tight as that of the SPP. In this work, by integrating a periodic multilayer structure that supports the Bloch surface wave with a metallic nanowire structure, a hybrid Bloch surface wave polariton could be excited. With the proposed hybrid nanowire structure, a hybrid mode is demonstrated with the deep subwavelength mode confinement and a propagation distance of tens of microns
    corecore