A Quick and Parallel Analytical Method Based on Quantum Dots Labeling for ToRCH-Related Antibodies

Quantum dot is a special kind of nanomaterial composed of periodic groups of II–VI, III–V or IV–VI materials. Their high quantum yield, broad absorption with narrow photoluminescence spectra and high resistance to photobleaching, make them become a promising labeling substance in biological analysis. Here, we report a quick and parallel analytical method based on quantum dots for ToRCH-related antibodies including Toxoplasma gondii, Rubella virus, Cytomegalovirus and Herpes simplex virus type 1 (HSV1) and 2 (HSV2). Firstly, we fabricated the microarrays with the five kinds of ToRCH-related antigens and used CdTe quantum dots to label secondary antibody and then analyzed 100 specimens of randomly selected clinical sera from obstetric outpatients. The currently prevalent enzyme-linked immunosorbent assay (ELISA) kits were considered as “golden standard” for comparison. The results show that the quantum dots labeling-based ToRCH microarrays have comparable sensitivity and specificity with ELISA. Besides, the microarrays hold distinct advantages over ELISA test format in detection time, cost, operation and signal stability. Validated by the clinical assay, our quantum dots-based ToRCH microarrays have great potential in the detection of ToRCH-related pathogens

RNA topoisomerase is prevalent in all domains of life and associates with polyribosomes in animals

DNA Topoisomerases are essential to resolve topological problems during DNA metabolism in all species. However, the prevalence and function of RNA topoisomerases remain uncertain. Here, we show that RNA topoisomerase activity is prevalent in Type IA topoisomerases from bacteria, archaea, and eukarya. Moreover, this activity always requires the conserved Type IA core domains and the same catalytic residue used in DNA topoisomerase reaction; however, it does not absolutely require the non-conserved carboxyl-terminal domain (CTD), which is necessary for relaxation reactions of supercoiled DNA. The RNA topoisomerase activity of human Top3β differs from that of Escherichia coli topoisomerase I in that the former but not the latter requires the CTD, indicating that topoisomerases have developed distinct mechanisms during evolution to catalyze RNA topoisomerase reactions. Notably, Top3β proteins from several animals associate with polyribosomes, which are units of mRNA translation, whereas the Top3 homologs from E. coli and yeast lack the association. The Top3β-polyribosome association requires TDRD3, which directly interacts with Top3β and is present in animals but not bacteria or yeast. We propose that RNA topoisomerases arose in the early RNA world, and that they are retained through all domains of DNA-based life, where they mediate mRNA translation as part of polyribosomes in animals

Transforming growth factor-β1 protects mechanically injured cortical murine neurons by reducing trauma-induced autophagy and apoptosis

Transforming growth factor β1 (TGF-β1) has a neuroprotective function in traumatic brain injury (TBI) through its anti-inflammatory and immunomodulatory properties. However, the precise mechanisms underlying the neuroprotective actions of TGF-β1 on the cortex require further investigation. In this study, we were aimed to investigate the regulatory function of TGF-β1 on neuronal autophagy and apoptosis using an in vitro primary cortical neuron trauma-injury model. LDH activity was assayed to measure cell viability, and intracellular [Ca2+] was measured using Fluo-4-AM in an in vitro primary cortical neuron trauma-injury model. RNA-sequencing (RNAseq), immunofluorescent staining, transmission electron microscopy (TEM), western blot and CTSD activity detection were employed. We observed significant enrichment of DEGs related to autophagy, apoptosis, and the lysosome pathway in trauma-injured cortical neurons. TEM confirmed the presence of autophagosomes as well as autophagolysosomes. Western blot revealed upregulation of autophagy-related protein light chain 3 (LC3-II/LC3-I), sequestosome 1 (SQSTM1/p62), along with apoptosis-related protein cleaved-caspase 3 in trauma-injured primary cortical neurons. Furthermore, trauma-injured cortical neurons showed an upregulation of lysosomal marker protein (LAMP1) and lysosomal enzyme mature cathepsin D (mCTSD), but a decrease in the activity of CTSD enzyme. These results indicated that apoptosis was up-regulated in trauma- injured cortical neurons at 24 h, accompanied by lysosomal dysfunction and impaired autophagic flux. Notably, TGF-β1 significantly reversed these changes. Our results suggested that TGF-β1 exerted neuroprotective effects on trauma- injured cortical neurons by reducing lysosomal dysfunction, decreasing the accumulation of autophagosomes and autophagolysosomes, and enhancing autophagic flux

Low-Temperature Preparation of Amorphous-Shell/ Nanocrystalline-Core Nanostructured Electrodes for Flexible Dye-Sensitized Solar Cells

An amorphous shell/nanocrystalline core nanostructured TiO2 electrode was prepared at low temperature, in which the mixture of TiO2 powder and TiCl4 aqueous solution was used as the paste for coating a film and in this film amorphous TiO2 resulted from direct hydrolysis of TiCl4 at 100◦C sintering was produced to connect the particles forming a thick crack-free uniform nanostructured TiO2 film (12 μm), and on which a photoelectrochemical solar cell-based was fabricated, generating a short-circuit photocurrent density of 13.58 mA/cm2, an open-circuit voltage of 0.647 V, and an overall 4.48 % light-to-electricity conversion efficiency under 1 sun illumination. Copyright © 2008 Dongshe Zhang et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. 1

Effect of Sodium Penetration on Microscopic Deformation of Carbon-Based Cathode Materials During Aluminum Electrolysis

In this paper, the macroscopic and microscopic deformation caused by sodium penetration in the carbon cathode has been studied during aluminum electrolysis. The distributions of sodium concentration in the carbon cathode has been measured by SEM-EDS. The microstructure change caused by the gradient of the sodium concentration in the carbon cathode has been studied using transmission electron microscopy (TEM). The results indicate that sodium penetration decreases with the increase of the penetration depth. The stresses caused by the gradient of the sodium concentration result in a remarkable change for the microstructure of the carbon cathode. The formation of dislocations resulting in dislocation arrays and the development of kink band networks bring about material damage growth and possibly subsequent weakening of the cathode. These results can provide useful information that is helpful in developing an improved comprehending of the microscopic deformation mechanism of the carbon cathode during aluminum electrolysis

Cdc28–Clb5 (CDK-S) and Cdc7–Dbf4 (DDK) collaborate to initiate meiotic recombination in yeast

S-phase cyclin-dependent kinase Cdc28–Clb5 (CDK-S) and Dbf4-dependent kinase Cdc7–Dbf4 (DDK) are highly conserved kinases well known for their roles in the initiation of DNA replication. CDK-S is also essential for initiation of meiotic recombination because it phosphorylates Ser30 of Mer2, a meiosis-specific double-strand break (DSB) protein. This work shows that the phosphorylation of Mer2 Ser30 by CDK-S primes Mer2 for subsequent phosphorylation by DDK on Ser29, creating a negatively charged “patch” necessary for DSB formation. CDK-S and DDK phosphorylation of Mer2 S30 and S29 can be bypassed by phosphomimetic amino acids, but break formation under these conditions is still dependent on DDK and CDK-S activity. Coordination between premeiotic S and DSB formation may be achieved by using CDK-S and DDK to initiate both processes. Many other proteins important for replication, recombination, repair, and chromosome segregation contain combination DDK/CDK sites, raising the possibility that this is a common regulatory mechanism

R: A quick and parallel analytical method based on quantum dots labeling for to RCH-related antibodies. Nanoscale Res Lett 2009

Abstract Quantum dot is a special kind of nanomaterial composed of periodic groups of II-VI, III-V or IV-VI materials. Their high quantum yield, broad absorption with narrow photoluminescence spectra and high resistance to photobleaching, make them become a promising labeling substance in biological analysis. Here, we report a quick and parallel analytical method based on quantum dots for ToRCH-related antibodies including Toxoplasma gondii, Rubella virus, Cytomegalovirus and Herpes simplex virus type 1 (HSV1) and 2 (HSV2). Firstly, we fabricated the microarrays with the five kinds of ToRCH-related antigens and used CdTe quantum dots to label secondary antibody and then analyzed 100 specimens of randomly selected clinical sera from obstetric outpatients. The currently prevalent enzyme-linked immunosorbent assay (ELISA) kits were considered as ''golden standard'' for comparison. The results show that the quantum dots labeling-based ToRCH microarrays have comparable sensitivity and specificity with ELISA. Besides, the microarrays hold distinct advantages over ELISA test format in detection time, cost, operation and signal stability. Validated by the clinical assay, our quantum dots-based ToRCH microarrays have great potential in the detection of ToRCH-related pathogens

Effects of CdSe/ZnS quantum dots covered multi-walled carbon nanotubes on murine embryonicstem cells

Stem cells nanotechnology has emerged as a new exciting area, and holds great potential for research and development of stem cells as novel therapeutic platforms for genetic, traumatic, and degenerative medicine. Vital to the success of this technology are approaches that reproducibly facilitate in vivo cell tracking, expansion, differentiation, and transplantation. Herein we reported the effects of CdSe/ZnS quantum dots covered multi-walled carbon nanotubes (FMNTs) on mice embryonic stem cell line CCE cells. The FMNTs were prepared by plasma surface treatment and characterized by high resolution transmission electron microscopy (HR-TEM), and incubated with murine ES CCE cells for 1 to 28 day.These ES cells were observed by confocal laser scanning microscopy, and were analyzed by real time reverse transcription-polymerase chain reaction (RTPCR), flow cytometry (FCM) and MTT method. Results showed that prepared FMNTs exhibited green fluorescent signal, could enter into ES cells in time-dependent means, more than 20 µg ml-1 FMNTs induced ES cells become smaller and smaller as the incubation time increased, and inhibited cell growth in dose-and time-dependent means, induced apoptosis of ES cells; conversely, 5 µg ml-1 FMNTs could markedly stimulate the expression of Sox1 and Hsp27, and inhibit expression of OCT4 in ES cells, FCM analysis showed that differentiation marker Flk-1 exhibited higher expression compared with control ES cells. In conclusion, high dose of FMNTs can inhibit proliferation of ES cells, low dose of FMNTs can improve the differentiation of ES cells, FMNTs can have potential applications in in vivo tracking, imaging and regulation of the proliferation and differentiation of ES cells