The coronavirus disease 2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a global health concern. The development of vaccines with high ...immunogenicity and safety is crucial for controlling the global COVID-19 pandemic and preventing further illness and fatalities. Here, we report the development of a SARS-CoV-2 vaccine candidate, Nanocovax, based on recombinant protein production of the extracellular (soluble) portion of the spike (S) protein of SARS-CoV-2. The results showed that Nanocovax induced high levels of S protein-specific IgG and neutralizing antibodies in three animal models: BALB/c mouse, Syrian hamster, and a non-human primate (
). In addition, a viral challenge study using the hamster model showed that Nanocovax protected the upper respiratory tract from SARS-CoV-2 infection. Nanocovax did not induce any adverse effects in mice (
var. albino) and rats (
). These preclinical results indicate that Nanocovax is safe and effective.
Ulvan, a sulfated heteropolysaccharide with structural and functional properties of interest for various uses, was extracted from the green seaweed Ulva papenfussii. U. papenfussii is an unexplored ...Ulva species found in the South China Sea along the central coast of Vietnam. Based on dry weight, the ulvan yield was ~15% (w/w) and the ulvan had a sulfate content of 13.4 wt%. The compositional constitution encompassed L-Rhamnose (Rhap), D-Xylose (Xylp), D-Glucuronic acid (GlcAp), L-Iduronic acid (IdoAp), D-Galactose (Galp), and D-Glucose (Glcp) with a molar ratio of 1:0.19:0.35:0.52:0.05:0.11, respectively. The structure of ulvan was determined using High-Performance Liquid Chromatography (HPLC), Fourier Transform Infrared Spectroscopy (FT-IR), and Nuclear Magnetic Resonance spectroscopy (NMR) methods. The results showed that the extracted ulvan comprised a mixture of two different structural forms, namely (“A3s”) with the repeating disaccharide →4)-β-D-GlcAp-(1→4)-α-L-Rhap 3S-(1→n, and (“B3s”) with the repeating disaccharide →4)-α-L-IdoAp-(1→4)-α-L-Rhap 3S(1→n. The relative abundance of A3s, and B3s was 1:1.5, respectively. The potential anticarcinogenic attributes of ulvan were evaluated against a trilogy of human cancer cell lineages. Concomitantly, Quantitative Structure–Activity Relationship (QSAR) modeling was also conducted to predict potential adverse reactions stemming from pharmacological interactions. The ulvan showed significant antitumor growth activity against hepatocellular carcinoma (IC50 ≈ 90 µg/mL), human breast cancer cells (IC50 ≈ 85 µg/mL), and cervical cancer cells (IC50 ≈ 67 µg/mL). The QSAR models demonstrated acceptable predictive power, and seven toxicity indications confirmed the safety of ulvan, warranting its candidacy for further in vivo testing and applications as a biologically active pharmaceutical source for human disease treatment.
c-Maf is one of the large Maf (musculoaponeurotic fibrosarcoma) transcription factors that belong to the activated protein-1 super family of basic leucine zipper proteins. Despite its overexpression ...in hematologic malignancies, the physiologic roles c-Maf plays in normal hematopoiesis have been largely unexplored. On a C57BL/6J background, c-Maf−/− embryos succumbed from severe erythropenia between embryonic day (E) 15 and E18. Flow cytometric analysis of fetal liver cells showed that the mature erythroid compartments were significantly reduced in c-Maf−/− embryos compared with c-Maf+/+ littermates. Interestingly, the CFU assay indicated there was no significant difference between c-Maf+/+ and c-Maf−/− fetal liver cells in erythroid colony counts. This result indicated that impaired definitive erythropoiesis in c-Maf−/− embryos is because of a non–cell-autonomous effect, suggesting a defective erythropoietic microenvironment in the fetal liver. As expected, the number of erythroblasts surrounding the macrophages in erythroblastic islands was significantly reduced in c-Maf−/− embryos. Moreover, decreased expression of VCAM-1 was observed in c-Maf−/− fetal liver macrophages. In conclusion, these results strongly suggest that c-Maf is crucial for definitive erythropoiesis in fetal liver, playing an important role in macrophages that constitute erythroblastic islands.
In vitro grafting is one of the promising techniques for fruit crop breeding. This study was performed to produce in vitro vigorous passion fruit rootstocks and developed a simple in vitro grafting ...protocol with the support of nylon microtubes—a low cost, wide availability, non-toxic and reusable material. The results showed that stem-lTCL explants (longitudinal thin cell layers) cultured on MS medium containing 0.5 mg/L BA and 0.5 mg/L NAA gave the highest shoot regeneration, and these shoots were initial materials for micropropagation of passion fruit rootstock. MSM medium containing 5 mg/L AgNPs increased shoot multiplication twofold higher than that of control and significantly reduced leaf yellowing and leaf drop during this stage. Rooting rate and quality of the plantlets were optimal on MSM medium contained with 2.5 mg/L IBA as well as their survival rate was enhanced in nursery. Nylon microtubes improved the efficiency of passion fruit in vitro grafts to 73.33% with yellow passion fruit as rootstock and purple passion fruit nodal segments as scion. In addition, the use of nylon microtubes significantly improved the in vitro growth of in vitro grafted plants resulting in increased survival rate and plantlet growth in the nursery stage. The present results provide an efficient protocol for micropropagation of yellow passion fruit for rootstock and production of purple passion fruit via nylon microtubule-mediated in vitro grafting.
Key message
An efficient protocol was established for multiplication of
in vitro
vigorous passion fruit rootstock via the application of thin cell layer culture techniques, nanotechnology and modification of the culture medium. Nylon microtubes enhanced the success rate of
in vitro
grafting and
ex vitro
grafted plant growth.
In order to increase the contribution of donor HSC cells, irradiation and DNA alkylating agents have been commonly used as experimental methods to eliminate HSCs for adult mice. But a technique of ...HSC deletion for mouse embryo for increase contribution of donor cells has not been published. Here, we established for the first time a procedure for placental HSC transplantation into E11.5 Runx1-deficient mice mated with G1-HRD-Runx1 transgenic mice (Runx1
::Tg mice) that have no HSCs in the fetal liver. Following the transplantation of fetal liver cells from mice (allogeneic) or rats (xenogeneic), high donor cell chimerism was observed in Runx1
::Tg embryos. Furthermore, chimerism analysis and colony assay data showed that donor fetal liver hematopoietic cells contributed to both white blood cells and red blood cells. Moreover, secondary transplantation into adult recipient mice indicated that the HSCs in rescued Runx1
::Tg embryos had normal abilities. These results suggest that mice lacking fetal liver HSCs are a powerful tool for hematopoiesis reconstruction during the embryonic stage and can potentially be used in basic research on HSCs or xenograft models.
We investigated the consequences of colistin use in backyard chicken farms in Vietnam by examining the prevalence of mcr-1 in fecal samples from chickens and humans. Detection of mcr-1-carrying ...bacteria in chicken samples was associated with colistin use and detection in human samples with exposure to mcr-1-positive chickens.
Fluorescent proteins with light wavelengths within the optical window are one of the improvements in in vivo imaging techniques. Near-infrared (NIR) fluorescent protein (iRFP) is a stable, nontoxic ...protein that emits fluorescence within the NIR optical window without the addition of exogenous substrate. However, studies utilizing an in vivo iRFP model have not yet been published. Here, we report the generation of transgenic iRFP mice with ubiquitous NIR fluorescence expression. iRFP expression was observed in approximately 50% of the offspring from a matings between iRFP transgenic and WT mice. The serum and blood cell indices and body weights of iRFP mice were similar to those of WT mice. Red fluorescence with an excitation wavelength of 690 nm and an emission wavelength of 713 nm was detected in both newborn and adult iRFP mice. We also detected fluorescence emission in whole organs of the iRFP mice, including the brain, heart, liver, kidney, spleen, lung, pancreas, bone, testis, thymus, and adipose tissue. Therefore, iRFP transgenic mice may therefore be a useful tool for various types of in vivo imaging.
•Somatic embryos regenerated from AgNPs-sterilized leaf explants of Ngoc Linh ginseng.•Tetraploid induction by colchicine in Panax vietnamensis Ha et Grushv. from somatic embryo.•Tetraploid plantlets ...had vigorous growth compared to the diploid plantlets.
In the present study, the protocol of polyploid induction via somatic embryogenesis of the Ngoc Linh ginseng (Panax vietnamensis Ha et Grushv.) (2n = 2x = 24) was developed. Ex vitro leaf explants were disinfected with AgNPs at concentrations of 0.05, 0.1, 0.2 and 0.5 g/L for 5, 10, 15, 20 and 30 min and cultured on MS medium supplemented with 1.0 mg/L 2,4-D, 0.5 mg/L NAA and 0.2 mg/L Kin for somatic embryogenesis. Globular embryos induced from the leaf explants were treated with colchicine by immersed method at different concentrations of 0, 0.1, 0.2, 0.3, 0.5 and 0.7% for 24, 36, 48 and 72 h. Then, these embryos were cultured on medium supplemented with 1.0 mg/L 2,4-D, 0.5 mg/L NAA and 0.2 mg/L Kin for secondary embryos induction. The ploidy level was identified by counting chromosomes of the root tip of plantlets derived from these secondary embryos. The results showed that the survival rate and somatic embryo induction the highest (65.56% and 29.89%, respectively) at 0.2 g/L AgNPs for 20 min. For colchicine treatment, the increase in the concentration and exposure time of colchicine decreased the survival rate of explants and the number of secondary embryos but increased the abnormal secondary embryo formation. Identifying the ploidy level showed that the treatments with colchicine concentrations from 0.3% to 0.5% for 48 h lead to tetraploid induction rates from 22.22% to 25.92%. The results also revealed that the tetraploids (2n = 4x = 48) had larger stomatal size, lower stomatal density, denser stomatal chloroplast density, and better growth than did the diploids.
Along with the development of the Internet of Things (IoT), waste management has appeared as a serious issue. Waste management is a daily task in urban areas, which requires a large amount of labour ...resources and affects natural, budgetary, efficiency, and social aspects. Many approaches have been proposed to optimize waste management, such as using the nearest neighbour search, colony optimization, genetic algorithm, and particle swarm optimization methods. However, the results are still too vague and cannot be applied in real systems, such as in universities or cities. Recently, there has been a trend of combining optimal waste management strategies with low-cost IoT architectures. In this paper, we propose a novel method that vigorously and efficiently achieves waste management by predicting the probability of the waste level in trash bins. By using machine learning and graph theory, the system can optimize the collection of waste with the shortest path. This article presents an investigation case implemented at the real campus of Ton Duc Thang University (Vietnam) to evaluate the performance and practicability of the system’s implementation. We examine data transfer on the LoRa module and demonstrate the advantages of the proposed system, which is implemented through a simple circuit designed with low cost, ease of use, and replace ability. Our system saves time by finding the best route in the management of waste collection.
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