Tube Development Research Articles

Development of biotesting method for water quality control

The article presents a method for biotesting natural waters based on the rate of growth of nasturtium pollen tubes on a nutrient medium prepared using tested water samples; pollen tubes of flowering plants are used as an indicator; the waters of a large water-transport artery Moscow Canal and the Klyazminskoye Reservoir are subject to biotesting. For the research, pollen of nasturtium plants, which has convenient for observation sizes of pollen grains and a high initial growth rate of pollen tubes, was selected. Within the process of research, the factors influencing the development of pollen tubes were identified and optimal conditions for germination were proposed. As well, the article attempts to indicate the state of water in the Moscow Canal during the season using the proposed method.

Studying Hedgehog Signaling During Mouse Neural Tube Development.

The identity of ventral neural progenitors in the neural tube is largely dependent on Hedgehog (Hh) signaling. Variations in staining patterns are excellentindicatorsof aberrant Hh signaling. Here we describe the basic protocol to stain for progenitor populations based on transcription factor expression. We also provide an overview of ciliary and centrosomal staining in the neural tube.

A theoretical study of condensation heat transfer in tubes with novel cross-sections

This paper presents a numerical study of stratified flow condensation heat transfer in tubes with novel cross-section designs. A design framework of the novel cross-section geometry was developed by first studying and analyzing the condensate film distribution in a circular tube. It was found that the circular arc diameter and orientation have effects on the condensate film thickness. Based on this understanding, four different cross-section designs (models N1, N2, N3 and N4) formed by connecting circular arcs of different curvatures at various orientations were proposed. The heat transfer performances of these models were compared to a circular tube of the same perimeter. Our simulations show that all models possess higher average heat transfer coefficients than a circular tube when no accumulated condensate layer is present. Among all the models proposed, model N4 exhibits the largest heat transfer enhancement ratio of 1.42 at ∊ = 0.96. The design of model N4 utilizes small circular arcs which are arranged in an orientation that increases the effect of the gravitational force, providing significant condensate film thickness reduction over a large area. This study not only demonstrates the possibility of enhancing condensation heat transfer by simply varying the tube curvature but also provided a design guideline which can be employed for the development of novel cross-section tubes that can be fabricated by advanced manufacturing techniques such as selective laser melting.

No developmental toxicity observed with dolutegravir in rat whole embryo culture.

An in vitro rat whole embryo culture study investigated whether direct exposure to dolutegravir (TivicayTM ) during the critical period for neural tube development would result in abnormal development. Dolutegravir (DTG), and HIV integrase inhibitor, was administered at 0 (vehicle), 5.3 μg/mL and 9.3 μg/mL on Gestation Day (GD) 9 through 11 (approximate 40 hour exposure period) along with positive (Valproic Acid) and negative (Penicillin G) controls. The DTG concentrations tested were selected based on clinical exposure at the maximum human recommended dose and maximum feasible concentration that could be formulated under the experimental conditions. Approximately 6% of DTG present in the culture media was absorbed into the embryos, demonstrating embryonic exposure at a similar level to that observed in a rat DTG placental transfer study. There was no effect in either the DTG or Penicillin G groups on visceral yolk sac size/morphology, embryo size, somite number and embryo morphology at any concentration tested. Valproic Acid, by contrast, produced statistically significant decreases in visceral yolk sac size, embryo size and somite number along with defects in visceral yolk sac and embryonic morphology, including neural tube defects (NTDs), in all embryos. DTG at the maximum human recommended dose administered to rats in a whole embryo culture assay did not produce any abnormal effects, while the positive control Valproic Acid produced abnormal effects, including neural tube defects.

Development of cost-effective shock tube based on experimental and numerical analysis

PurposeThe purpose of the study is to design economical shock tube. It is an instrument used for experimental investigations not only related to shock phenomena but also for the behavior of the material when it is subjected to high-speed flow. The material used here in this shock tube is stainless steel ss304 and aluminum. A shock tube consists of two sections, namely, the driver and the driven. The gas in the driven and driver is filled with atmospheric air and nitrogen, respectively, under the predominant condition.Design/methodology/approachThe focus of the study is on the design and fabrication of shock tubes. a shock tube is a research tool to make an aerodynamic test in the presence of high pressure and temperature by generating moving normal shock waves under controlled conditions.FindingsThe main necessity for instrumentation in the shock tube experiment is to know the velocity of the moving shock wave from which the other parameters can be calculated. the pressure transducers are located in the shock tube in various locations to measure aerodynamic parameters in terms of pressure.Originality/valueThe main objective of this project work is to make an experimental setup to produce supersonic velocity with the readily available material in the market in a highly safe manner.

Costunolide Influences Germ Tube Orientation in Sunflower Broomrape - A First Step Toward Understanding Chemotropism.

Orobanche cumana WALLR. is a host-specific root parasite of cultivated sunflowers with increasing economic importance in Europe, North Africa, and parts of Asia. While sesquiterpene lactones (STLs) released from sunflower roots were identified as natural germination stimulants of O. cumana seeds in the soil, the chemical nature of the signals guiding the emerging germ tube toward the host root has remained unknown hitherto. Thus, we designed a bioassay that allowed the observation of broomrape germination and subsequent germ tube development in the presence of substances with putative chemotropic activity. Root exudates and sunflower oil extracts, both containing STLs in micromolar concentrations, caused the positive chemotropic orientation of germ tubes. A similar positive chemotropic effect was achieved with costunolide, one of the four STLs of sunflower present in the exudate and oil extracts. In contrast, GR24, a synthetic strigolactone (SL) with germination-inducing activity on O. cumana seeds, showed no effect on the germ tube orientation. The effect of costunolide was concentration-dependent and within the range of its natural micromolar occurrence in roots. We assume that an STL gradient is responsible for the stronger inhibition of elongation growth on the host-facing flank of the germ tube compared with the far side flank. This would confer a double role of STLs from sunflower root exudates in the sunflower–broomrape interaction, namely, as germination stimulants and as chemotropic signals.

High-frequency acoustic impedance tube based on MEMS microphones

Acoustic impedance tubes are commonly used to measure a test specimen's acoustic characteristics, such as reflection factor, absorption coefficient, or acoustic impedance, in combination with one or two condenser measurement microphones according to associated standards. In the development process of an impedance tube, the microphone diaphragm's size has an important role in the measurement quality. On the one hand, the microphone diameter has to be large enough to ensure the possibility of measuring at low sound pressure levels (SPLs), but on the other hand, the size of the microphone diaphragm should be small in order not to influence the sound propagation through the impedance tube due to the microphone coupling. Micro-Electro-Mechanical Systems (MEMS) microphones are recently widely applied in various acoustic applications due to their small size and high sensitivity. This paper proposes the development of an acoustic impedance tube equipped with 16 MEMS microphones and an inner diameter of 8 mm with an operating frequency range between 60 Hz and 16 kHz. The bottom port MEMS microphones are connected via a 1 mm hole to the tube. The system evaluation is based on standard test specimens like empty probe adapters, rigid termination, and porous absorbers.

Single-cell transcriptome profiling of the human developing spinal cord reveals a conserved genetic programme with human-specific features.

ABSTRACTThe spinal cord receives input from peripheral sensory neurons and controls motor output by regulating muscle innervating motor neurons. These functions are carried out by neural circuits comprising molecularly distinct neuronal subtypes generated in a characteristic spatiotemporal arrangement from progenitors in the embryonic neural tube. To gain insight into the diversity and complexity of cells in the developing human neural tube, we used single-cell mRNA sequencing to profile cervical and thoracic regions in four human embryos of Carnegie stages (CS) CS12, CS14, CS17 and CS19 from gestational weeks 4-7. Analysis of progenitor and neuronal populations from the neural tube and dorsal root ganglia identified dozens of distinct cell types and facilitated the reconstruction of the differentiation pathways of specific neuronal subtypes. Comparison with mouse revealed overall similarity of mammalian neural tube development while highlighting some human-specific features. These data provide a catalogue of gene expression and cell type identity in the human neural tube that will support future studies of sensory and motor control systems. The data can be explored at https://shiny.crick.ac.uk/scviewer/neuraltube/.

Development and test of a multi-target transmission X-ray tube based on the electron deflection in an electric field

The multitarget X-ray tube has special advantage for the X-ray fluorescence analysis of complex sample. The current paper reports on a four-target transmission X-ray tube based on the electron deflection in an electric field. It consists of four 90° sector targets, which are Cr, Ni, Au, Mo. The electron trajectory is selectively bent by the deflection field to bombard the desired target. The emission spectrum was detected by the silicon drift detector (SDD) at 1.1 W (−22 kV, 50 μA). The results showed the characteristic X-rays of the corresponding target produced clearly, especially for the Cr or Au target with a high intensity. The focal spot size was tested using the pinhole camera method. The results showed the electrons were bent effectively, the corrected area of real focal spot was between about 4 mm2 to 9 mm2. This multitarget X-ray tube will provide the selective X-ray spectrum of the application for the sample analysis.

Altered Cytokine Response of Human Brain Endothelial Cells after Stimulation with Malaria Patient Plasma.

Infections with the deadliest malaria parasite, Plasmodium falciparum, are accompanied by a strong immunological response of the human host. To date, more than 30 cytokines have been detected in elevated levels in plasma of malaria patients compared to healthy controls. Endothelial cells (ECs) are a potential source of these cytokines, but so far it is not known if their cytokine secretion depends on the direct contact of the P. falciparum-infected erythrocytes (IEs) with ECs in terms of cytoadhesion. Culturing ECs with plasma from malaria patients (27 returning travellers) resulted in significantly increased secretion of IL-11, CXCL5, CXCL8, CXCL10, vascular endothelial growth factor (VEGF) and angiopoietin-like protein 4 (ANGPTL4) if compared to matching controls (22 healthy individuals). The accompanying transcriptome study of the ECs identified 43 genes that were significantly increased in expression (≥1.7 fold) after co-incubation with malaria patient plasma, including cxcl5 and angptl4. Further bioinformatic analyses revealed that biological processes such as cell migration, cell proliferation and tube development were particularly affected in these ECs. It can thus be postulated that not only the cytoadhesion of IEs, but also molecules in the plasma of malaria patients exerts an influence on ECs, and that not only the immunological response but also other processes, such as angiogenesis, are altered.

Axial elongation of caudalized human organoids mimics aspects of neural tube development.

Axial elongation of the neural tube is crucial during mammalian embryogenesis for anterior-posterior body axis establishment and subsequent spinal cord development, but these processes cannot be interrogated directly in humans as they occur post-implantation. Here, we report an organoid model of neural tube extension derived from human pluripotent stem cell (hPSC) aggregates that have been caudalized with Wnt agonism, enabling them to recapitulate aspects of the morphological and temporal gene expression patterns of neural tube development. Elongating organoids consist largely of neuroepithelial compartments and contain TBXT+SOX2+ neuro-mesodermal progenitors in addition to PAX6+NES+ neural progenitors. A critical threshold of Wnt agonism stimulated singular axial extensions while maintaining multiple cell lineages, such that organoids displayed regionalized anterior-to-posterior HOX gene expression with hindbrain (HOXB1) regions spatially distinct from brachial (HOXC6) and thoracic (HOXB9) regions. CRISPR interference-mediated silencing of TBXT, a Wnt pathway target, increased neuroepithelial compartmentalization, abrogated HOX expression and disrupted uniaxial elongation. Together, these results demonstrate the potent capacity of caudalized hPSC organoids to undergo axial elongation in a manner that can be used to dissect the cellular organization and patterning decisions that dictate early human nervous system development.

A comparison expression analysis of CXCR4, CXCL9 and Caspase-9 in dermal vascular endothelial cells between keloids and normal skin on chemotaxis and apoptosis

This present study was designed to explore key biological characteristics and biomarkers associated with dermal vascular endothelial cells of keloids. GSE121618 dataset was downloaded in the Gene Expression Omnibus (GEO) Database, including the KECs group and NVECs group. Through GEO2R, we have screened the differentially expressed genes (DEGs) and performed gene ontology (GO), Gene Set Enrichment Analysis (GSEA), and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. Then, we constructed a protein–protein interaction (PPI) network and analyzed hub genes via the Search Tool for the Retrieval of Interacting Genes (STRING) Online Database and Cytoscape software. Furthermore, experiments were performed to validate the expression of selected genes, including H&E staining, immunohistochemical staining, Western blot, and RT-qPCR. A total of 1040 DEGs were selected with GEO2R online tools. Most of the enriched pathways and processes focus on cell migration, tube development, chemotaxis, cell motility, and regulation of apoptosis. With the assistance of STRING and Cytoscape, hub genes were selected. In our validation experiments of RT-qPCR, the mRNA expression of selected genes has significant differences between different groups in tissue and cell experiments. As was shown in immunohistochemical staining, the proteins of CXCR4, CXCL9, and Caspase-9 had higher expression levels in tissue samples of the Keloid group than the Normal skin group. Western blot and RT-qPCR in dermal vascular endothelial cell experiments were consistent with the aforementioned results. This study has provided a deeper analysis of the pathogenesis of dermal vascular endothelial cells in keloids. Genes of CXCR4, CXCL9, and Caspase-9 may influence the processes of inflammatory responses and vascular endothelial cell apoptosis to exert crucial effects in the development of keloids. Abbreviations: GEO: gene expression omnibus; DEGs: differentially expressed genes; KVECs: keloid vascular endothelial cells; NVECs: normal skin vascular endothelial cells; GO: gene ontology; KEGG: Kyoto encyclopedia of genes and genomes; PPI: protein protein interaction; BP: biological process; CC: cellular component; MF: molecular function; GSEA: gene set enrichment analysis; STRING: search tool for the retrieval of interacting genes; MCODE: molecular complex detection

A high level of KLF12 causes folic acid-resistant neural tube defects by activating the Shh signaling pathway in mice†.

Although adequate periconceptional folic acid (FA) supplementation has reduced the occurrence of pregnancies affected by neural tube defects (NTDs), the mechanisms underlying FA-resistant NTDs are poorly understood, and thus NTDs still remain a global public health concern. A high level of Krüppel-like factor 12 (KLF12) exerts deleterious effects on heath in most cases, but evidence for its roles in development has not been published. We observed KLF12-overexpressing mice showed disturbed neural tube development. KLF12-overexpressing fetuses died in utero at approximately 10.5days post-coitus, with 100% presenting cranial NTDs. Neither FA nor formate promoted normal neural tube closure in mutant fetuses. The RNA-seq results showed that a high level of KLF12 caused NTDs in mice via overactivating the sonic hedgehog (Shh) signaling pathway, leading to the upregulation of patched 1, GLI-Krüppel family member GLI1, hedgehog-interacting protein, etc., whereas FA metabolism-related enzymes did not express differently. PF-5274857, an antagonist of the Shh signaling pathway, significantly promoted dorsolateral hinge point formation and partially rescued the NTDs. The regulatory hierarchy between a high level of KLF12 and FA-resistant NTDs might provide new insights into the diagnosis and treatment of unexplained NTDs in the future.

Proteomic Analysis of Generative and Vegetative Nuclei Reveals Molecular Characteristics of Pollen Cell Differentiation in Lily.

In plants, the cell fates of a vegetative cell (VC) and generative cell (GC) are determined after the asymmetric division of the haploid microspore. The VC exits the cell cycle and grows a pollen tube, while the GC undergoes further mitosis to produce two sperm cells for double fertilization. However, our understanding of the mechanisms underlying their fate differentiation remains limited. One major advantage of the nuclear proteome analysis is that it is the only method currently able to uncover the systemic differences between VC and GC due to GC being engulfed within the cytoplasm of VC, limiting the use of transcriptome. Here, we obtained pure preparations of the vegetative cell nuclei (VNs) and generative cell nuclei (GNs) from germinating lily pollens. Utilizing these high-purity VNs and GNs, we compared the differential nucleoproteins between them using state-of-the-art quantitative proteomic techniques. We identified 720 different amount proteins (DAPs) and grouped the results in 11 fate differentiation categories. Among them, we identified 29 transcription factors (TFs) and 10 cell fate determinants. Significant differences were found in the molecular activities of vegetative and reproductive nuclei. The TFs in VN mainly participate in pollen tube development. In comparison, the TFs in GN are mainly involved in cell differentiation and male gametogenesis. The identified novel TFs may play an important role in cell fate differentiation. Our data also indicate differences in nuclear pore complexes and epigenetic modifications: more nucleoporins synthesized in VN; more histone variants and chaperones; and structural maintenance of chromosome (SMC) proteins, chromatin remodelers, and DNA methylation-related proteins expressed in GN. The VC has active macromolecular metabolism and mRNA processing, while GC has active nucleic acid metabolism and translation. Moreover, the members of unfolded protein response (UPR) and programmed cell death accumulate in VN, and DNA damage repair is active in GN. Differences in the stress response of DAPs in VN vs. GN were also found. This study provides a further understanding of pollen cell differentiation mechanisms and also a sound basis for future studies of the molecular mechanisms behind cell fate differentiation.

Effect of buscopan, a compound that alleviates cramps, on the developing nervous system of the chick embryo.

Buscopan is used to treat stomach cramps including those resulting from irritable bowel syndrome, bladder cramps, and pain related to menstruation. Its pregnancy category is determined as C. It has been shown in experimental animal studies that the drug has a negative effect on the embryo, but sufficient and well-controlled studies have not been conducted in humans. The aim of this study is to investigate effects of buscopan on the development of the neural tube (NT) in chick embryos. Sixty specific pathogen-free (SPF) fertilized eggs were used. SPF eggs were placed in an incubator and divided into six groups at 28 hr of incubation. Five different doses (low to high) of buscopan were injected sub-blastodermally.At the end of 48 hr, the embryos were evaluated morphologicallyand histopathologically. The argyrophilic nucleolar-organizing region (AgNOR) method was used in this study to determine the proliferation activity of cells in NT development in chick embryos. AgNOR number and total AgNOR area/nuclear area (TAA/NA) were detected for each embryo. Depending on the dose, the embryo's crown-rump length and somite number decreased (p < .05). Significant differences were detected among all groups for mean AgNOR number (p < .05) and TAA/NA ratio (p < .05). Considering the average count of AgNOR cells and TAA/NA ratio, it was found that there was a decrease in cell division depending on the dose. It was determined that buscopan treatment on chick embryos adversely affected early nervous system and NT development.

Pregnancy preeclampsia: the main stages of pathogenesis. An infuence into fetal organogenesis (literature review)

In the current article there is observed a serious problem of the development of preeclampsia (PE) at a level of severity among women in Ukraine. It is disassembled in the description of the main theories of the development of PE: allergic, hormonal and renal. So that it can be instilled in some types of diseases and the theory of cortical-visceral ailments, which is leading on the pink modern data.The study of cephalic changes to the pathogenesis of PE made it possible to see and describe the peculiarities of the structure of the placenta’s vessels with this pathology with an eye on the development of endothelial dysfunction; hormone-stimulating activity in the mother - placenta - fetus system. Statistically, persons are indicated in a hematoencephalic institution, they are seen in the organisms of fetuses from mothers from the stage of severity. All the above specialties are seen as far as the degree of severity of the PE. It has been shown that in fetuses from mothers and PEs in the later ontogeny, there may be a breakdown of the implementation and the main stages in the development of cells, uterus and uterine tubes. Moreover, there is a trend towards the development of the pathology of the organs of the statutory system in case of women, women of all types of mothers from the moderate and severe stage, as well as a great number of changes in the development of PE at a given birth.

Early Prenatal Diagnosis And Prevention Of Birth Damage Development In Children (Spina Bifida - A Defect In The Development Of The Nervous System)

Spina bifida-is a defect in the development of the neural tube, which is a splittinq of the spinal canal and is one of the most common conqenital malformation of the fetus. Worldwidt, the incidence of fetal neural tube defects ranqes from 0,17 to 6,39 per 1000 newborns. This article describes methods for early diaqnosis of fetal neural tube malformation in earle preqnancy and the results of studies of preqnant woman at different staqes of preqnancy.

Methylation Patterns in the 5’ Flanking Region of The Hoxb9 Gene in Sea Turtle Embryos with Congenital Malformations

Sea turtles are wild animals whose embryonic development largely depends on environmental factors. The shell of sea turtles is a novelty among vertebrates and follows a Hox code and axial formula for the group. The hoxb9 gene is a transcription factor involved in the regulation of embryonic development, mainly during neural tube development and plays an important role in shaping the thoracic-lumbar transition of sea turtles. Although it is known that Hox genes are regulated by chromatin modulating proteins, DNA methylation in CpG islands may also contribute to gene regulation. Previous studies have shown a high prevalence of congenital malformations in the olive ridley sea turtle (Lepidochelys olivacea), including Schistosomus Reflexus (SR) syndrome. Here we studied the methylation profiles in the 5’ flanking region of hoxb9 comparing normal and abnormal sea turtle embryos. Our results indicate that methylation of the putative promoter region of hoxb9 in sea turtle embryos occurred, however methylated cytosines showed individual patterns, not directly related to the development of congenital malformations.

From Neural Crest to Definitive Roof Plate: The Dynamic Behavior of the Dorsal Neural Tube.

Research on the development of the dorsal neural tube is particularly challenging. In this highly dynamic domain, a temporal transition occurs between early neural crest progenitors that undergo an epithelial-to-mesenchymal transition and exit the neural primordium, and the subsequent roof plate, a resident epithelial group of cells that constitutes the dorsal midline of the central nervous system. Among other functions, the roof plate behaves as an organizing center for the generation of dorsal interneurons. Despite extensive knowledge of the formation, emigration and migration of neural crest progenitors, little is known about the mechanisms leading to the end of neural crest production and the transition into a roof plate stage. Are these two mutually dependent or autonomously regulated processes? Is the generation of roof plate and dorsal interneurons induced by neural tube-derived factors throughout both crest and roof plate stages, respectively, or are there differences in signaling properties and responsiveness as a function of time? In this review, we discuss distinctive characteristics of each population and possible mechanisms leading to the shift between the above cell types.

Review on the effect of heat exchanger tubes on flow behavior and heat/mass transfer of the bubble/slurry reactors

Bubble/Slurry bubble column reactors (BCR/SBCR) are intensively used as multiphase reactors for a wide range of application in the chemical, biochemical and petrochemical industries. Most of these applications involve complicate gas–liquid/gas–liquid–solid flow behavior and exothermic process, thus it is necessary to equip the BCR/SBCR with heat exchanger tubes to remove the heat and govern the performance of the reactor. Amounts of experimental and numerical studies have been carried out to describe the phenomena taking place in BCR/SBCRs with heat exchanger tubes. Unfortunately, little effort has been put on reviewing the experiments and simulations for examining the effect of internals on the performance and hydrodynamics of BCR/SBCR. The objective of this work is to give a state-of-the-art review of the literature on the effects of heat exchanger tubes with different types and configurations on flow behavior and heat/mass transfer, then provide adequate information and scientific basis for the design and the development of heat exchanger tubes in BCR/SBCR, ultimately provide reasonable suggestions for better comprehend the performance of different heat exchanger tubes on hydrodynamics.