Early Stages Of Cell Development Research Articles

Magnetic Force Dilatometry of Silicon-NMC622 Lithium-Ion Coin Cells: The Effects of Binder, Capacity Ratio, and Electrolyte Selection

Operando cell expansion measurements on Si-NMC622 coin cells using a magnetic dilatometer were performed to understand the effects of electrode binder content, electrode formulation, negative-to-positive electrode capacity ratio (N/P ratio), and electrolyte selection on reversible and irreversible cell expansions. Our experiments reveal a complex relationship between cell properties, imparted by the selected cell parameters, and cell expansion. Reversible cell expansions scaled with cell discharge capacity and electrode mechanical properties, while irreversible cell expansions were sensitive to capacity fade, silicon utilization, and electrolyte decomposition mechanisms. Additionally, volumetric cell energy densities were calculated using the measured capacities and irreversible expansions over the life of the cells. We show that judicious selection of cell parameters can improve volumetric energy density after 200 charge/discharge cycles by approximately two-fold. Our work provides valuable insight, at an early stage of cell development, towards minimizing the effects of cell expansion on battery cell, pack, and module designs.

Breast ovarian cancer syndrome

BRCA1 and BRCA2, known as breast and ovarian cancer predisposition genes, were discovered in the 1990s. As part of a normal genetic structure, these genes are intrinsic to all human beings, but they are mutated in some individuals increasing the risk for breast and ovarian cancers development. BRCA1 is not only expressed in endocrine tissues but is also detected in other cells such as the neuroepithelial cells in the early stage of cell development. Like BRCA1, BRCA2 is also expressed in a wide variety of tissues and is observed with higher rates in the breast and thymus and with lower rates in the lung, ovary and spleen. We presented to you a case of 40 year old female admitted in surgical ward with lump in the left breast since 2 months with ipsilateral discrete axillary lymphadenopathy. Bilateral sono-mammography showed BIRADS V lesion in left breasts with satellite nodules. Ultrasonography of abdomen and pelvis showed large left adnexal solid mass lesion and right sided ovarian cyst with retrocaval, preaortic lymphadenopathy. Patient underwent a diagnostic laparoscopy which was converted to a laparotomy. Total abdominal hysterectomy with bilateral salphingo-oophorectomy was done. For the breast lump, patient underwent left sided modified radical mastectomy. Gene testing for revealed BRCA1 positivity. Chemotherapy was given to cover both breast and ovarian carcinoma. Patient came back with abdominal distension after 9 months and was offered palliative care. Patient succumbed for disease after 1 year after diagnosis. We reviewed the literature for the same.

Internet of health things-driven deep learning system for detection and classification of cervical cells using transfer learning

Cervical cancer is one of the fastest growing global health problems and leading cause of mortality among women of developing countries. Automated Pap smear cell recognition and classification in early stage of cell development is crucial for effective disease diagnosis and immediate treatment. Thus, in this article, we proposed a novel internet of health things (IoHT)-driven deep learning framework for detection and classification of cervical cancer in Pap smear images using concept of transfer learning. Following transfer learning, convolutional neural network (CNN) was combined with different conventional machine learning techniques like K nearest neighbor, naive Bayes, logistic regression, random forest and support vector machines. In the proposed framework, feature extraction from cervical images is performed using pre-trained CNN models like InceptionV3, VGG19, SqueezeNet and ResNet50, which are fed into dense and flattened layer for normal and abnormal cervical cells classification. The performance of the proposed IoHT frameworks is evaluated using standard Pap smear Herlev dataset. The proposed approach was validated by analyzing precision, recall, F1-score, training–testing time and support parameters. The obtained results concluded that CNN pre-trained model ResNet50 achieved the higher classification rate of 97.89% with the involvement of random forest classifier for effective and reliable disease detection and classification. The minimum training time and testing time required to train model were 0.032 s and 0.006 s, respectively.

Multi-Dimensional Modeling of the Influence of Cell Design on Temperature, Displacement and Stress Inhomogeneity in Large-Format Lithium-Ion Cells

In this paper, an efficient multi-dimensional approach to model mechanical effects in lithium-ion cells is presented. Using this modeling approach, we introduce mechanical criteria to rate different cell designs, complementary to commonly used criteria such as homogeneity of temperature or current density distribution. The additionally considered mechanical criteria are the displacement distribution on the cell due to the superposition of intercalation induced volume changes and thermal expansion, and the stresses in the electrodes’ active material particles. Two cell designs are compared comprising identical electrode stack dimensions with differing tab alignments. The model shows that the variation in local cell displacement is small due to the overlay of thermal and intercalation displacement, which act in opposite directions during discharge. Looking into the stress formation in the active material particles, we found that the tab pattern can influence the maximum stress and the gradients in stress distribution significantly, especially for the positive electrode particles. Our study shows the interaction of the electrochemical, electrical, thermal, and mechanical behavior of large-format pouch cells, representing a step toward a better understanding of the complex processes in lithium-ion cells and enabling the multi-disciplinary design optimization considering mechanical effects in an early stage of cell development.

Ultrastructural calli analysis of Inga vera Willd. subsp. Affinis (DC.) T.D. Penn

Subcellular changes are relevant to understand plant organogenesis and embryogenesis in the early stages of cell development. The cytology during cell development in tissue culture is however still poorly characterized. This study aimed to characterize the ultrastructural differences related to callogenesis of anthers, ovaries, leaf and nodal segments of Inga vera Willd. subsp. Affinis (DC.) T.D. Penn. Flower buds, nodal segments and leaves were disinfected and inoculated in test tubes containing MS medium with 3% sucrose and 4.5µM 2.4-D, except for leaf callogenesis, where 9µM of this auxin was used, and for the callogenesis of anthers and ovaries, where the culture medium was enriched with 0.25% activated charcoal and 90µM PVP. After 45 days in culture medium, the anther, ovary, leaf and nodal segment calli were fixed in Karnovisky and prepared for visualization by scanning and transmission electron microscopy. Ultrastructural differences were observed among the callus cells of anthers, ovaries, segments and leaves. There was no evidence of somatic embryo formation in the anther, leaf and nodal segment calli, in spite of some embryogenic characteristics in the cells. The ovary calli, with indications of embryo formation, seem to be the most responsive explant source for embryogenesis.

Reprogramming of root epidermal cells in response to nutrient deficiency

Post-embryonic development of the root system is highly plastic to environmental cues, compensating for the sessile lifestyle of plants. The fate of epidermal cells of Arabidopsis roots is particularly responsive to nutritional signals, leading to an increase in the root's surface area in the absence of the essential but immobile minerals iron, phosphate and manganese. The resulting phenotype is characteristic of the respective condition. Growth under nutrient starvation affects the expression of genes involved in cell specification, indicating that environmental signals are perceived at an early stage of cell development. Cell fate decisions are controlled at different levels, probably integrated at the level of chromatin organization.

The self-assembly of keratin intermediate filaments into macrofibrils: Is this process mediated by a mesophase?

Abstract Within wool and hair follicle cells, differences in the mode of assembly of intermediate filaments (IFs) into macrofibrils are key factors leading to the classification of different cortical cells as ortho, meso, or para cells. This paper offers a model for macrofibril formation based on the generic propensity of particles of high axial ratio to separate into isotropic and anisotropic phases above a certain low concentration. The statistical mechanical theories of Flory describing such behaviour in mesogenic polymers are applied to this case. The effects of random coil protuberances on the IF rods are deduced to be important in achieving the observed packing density in the mesophase. Observational evidence to support the mesophase hypothesis in the early stages of cell development is reviewed, providing considerable support for the model.

High aspartate accumulation and defect of glutamate/aspartate transport in low potassium dog red blood cells

The accumulation of Asp in low potassium (LK) dog red blood cells (RBCs) with defective Na-dependent (ND) glutamate (Glu)/aspartate (Asp) transport was examined. In RBCs with LK and defective ND-Glu/Asp transport (LK/GAT−), the amino acid influx defect appears to be specific to Glu/Asp, since influxes of the neutral amino acids alanine (Ala) and glutamine (Gln) were similar in both LK/GAT− RBCs and LK dog RBCs without the defect (LK/GAT+). Contrary to what might be expected with this transport defect, the Asp concentration in LK/GAT− RBCs was 10-fold higher than that in LK/GAT+ RBCs. Large, light RBCs separated by specific gravity were younger than small, dense RBCs in both LK/GAT− and LK/GAT+ RBCs. The youngest 10% of the cells had a 20% higher Asp concentration than the oldest 10% of the cells in both LK/GAT+ and LK/GAT− RBCs. The Glu and Gln concentrations decreased by 37%–47% as the cells aged, whereas Asp concentration decreased by 18%–19%. Therefore, the change in Asp metabolism during cell ageing might be smaller than the changes in the other amino acids. Thus, the Asp accumulation perhaps occurs at an early stage of cell development in LK/GAT− RBCs. The most likely cause of the Asp accumulation is a defect in Asp extrusion through ND-Glu/Asp transport.

Uptake and localization of lead in corn (Zea mays L.) seedlings, a study by histochemical and electron microscopy

A detailed microscopic analyses of the mode of lead uptake and localization in root, stem and leaf initials of corn seedlings grown in cultural solution is reported. Lead, as other minerals, was passively absorbed into the root tip region and transported by the active apical growth force. The entrance of lead was mainly from the thin epidermal cell walls at the meristematic region. Only limited amounts of lead entered into protoplasts, primarily during the early stage of cell development. However, accumulation of lead within cell walls increased as cells matured. Both local and long distance transport of lead were apoplastic. Once the vascular stele differentiated from the ground meristem, lead entered into the central conducting systems. Lead was also absorbed from the water absorbing zone but this lead mainly remained in the cortex. The Casparin strip was an effective barrier limiting the movement of lead. However, transport through passage cells was observed. The direction of lead movement was also mainly towards high growth rate areas as seen at meristematic root initials, the leaf primordia and the transaction zone at the stem apical meristem. Damaged plasmalemmae allowed lead to enter cells from cell walls. Lead deposition in the cytoplast was observed.

COMPARATIVE ANALYSIS OF THE FINE STRUCTURE OF YOUNG AND ADULT INDIVIDUALS OF DUNALIELLA SALINA (POLYBLEPHARIDACEAE, CHLOROPHYCEAE) WITH EMPHASIS ON THE FLAGELLAR APPARATUS1

ABSTRACTIndividuals of Dunaliella salina (Dunal.) Teod. change their shape during ontogenesis. Here we describe the fine structure of this species with emphasis on distinctions between young and adult individuals. The cell coat is present at early stages of cell development and may be synthesized by vesicles of nuclear membrane‐associated endoplasmic reticulum. Scanning electron microscopical observations show differences in the surface pattern of the cell coat in young and adult cells. The nucleus of young cells is more or less spherical, whereas that of adult cells is pyriform. The Golgi apparatus is positioned immediately under the basal bodies and consists of three dictyosomes in young cells and six to eight dictyosomes in adult cells. The flagellar apparatuses of young and adult cells have a 1/7 o'clock (i.e. clockwise) displacement of basal bodies and are grossly similar, but there are subtle differences between specific components. Two non‐axonemic basal bodies (1′, 2′) appear in a plane perpendicular to that determined by the flagella‐bearing basal bodies (1, 2). The cruciate microtubular rootlet system has a 4–2–4–2 alternation pattern. In adult cells, rhizoplasts emerge from each terminal body and run parallel to the four rootlets.

The endoplasmic reticulum in the cortex of developing guard cells: Coordinate studies with chlorotetracycline and osmium ferricyanide

The distribution of endoplasmic reticulum (ER) was investigated in young guard cells of Vicia faba and Allium cepa in order to gain more information on the control of guard cell development. Young, living guard cells of V. faba fluoresce when exposed to 25–100 μ M chlorotetracycline (CTC). Intense fluorescence is restricted to the cytoplasm between the nucleus and adjacent regions of the ventral and paradermal walls. Much of the fluorescence is fibrillar in appearance and seems to arise from endomembranes, but not from particulate organelles such as mitochondria and plastids. A similar fluorescence pattern is produced by the membrane probes oxytetracycline and N-phenyl-1-napthylamine. Procaine and dibucaine render the fluorescence highly prone to photobleaching. Fluorescence appears near the ventral wall during early stages of cell development but declines when the guard cells mature. Epidermal tissue of V. faba and A. cepa was examined in the electron microscope with the aid of osmium ferricyanide staining. ER appears to be concentrated in regions of the guard cell that exhibit intense CTC fluorescence, while no other organelles (e.g., mitochondria) are similarly distributed. Much of the ER consists of a tubular network in close proximity to the plasmalemma. Our results indicate that the ER becomes asymmetrically distributed in young guard cells adjacent to those regions of the cell wall that undergo extensive thickening during cell differentiation. Furthermore, these membranes appear to sequester divalent cations such as Ca 2+.

Histological Studies on breaking Resistance of Lower Internodes in Rice Culm : II. Ultrastructural and histochemical observations on the secondary wall formation.

In this paper, we report an observation with light and electron microscope on the process of the secondary wall thickening and lignin accumulation in the cells of the 4th internode from the top of rice culm, var. Koshihikari. Materials for ultra thin sections were fixed in 2-4% glutaraldehyde, postfixed with 1-2% osmium tetroxide, and embedded in Spurr's resin. Meshes were stained with uranium and lead. For histochemical detections of lignin, free hand sections, 60-80 μm in thickness, were treated with Maule's reagents (M-reaction) and phloroglucinol-HCl (P-reaction). The secondary wall of the cortical fibers makes a start of thickening just after the cell has completed its elongation. It usually consists of three layers; S1, S2 and S3. In crease in secondary wall thickness is associated with increase in number of Golgi apparatus, Golgi vesicles, exocytosis and invagination. The ribosomes are often present as polysomes on the rough endoplasmic reticulum, some of which connect with the plasmalemma (Figs. 1-4). The fiber cells have smaller diameter and thicker walls in the outer rows near the epidermis than those in the inner rows which sometimes lack S3 layer. The secondary walls of the tips of fiber cells thicken more slowly and are thinner than those of the central part (Fig. 5). The epidermal long cells have a large number of small papillae, and a number of large ones on both sides of the short cells, but a fewer papillae on the small vascular bundle (Fig. 6). The aspects of cell organelles at their wall thickening stage are similar to those in the cortical fibers (Figs. 8-10). At this stage, silica deposition cetripetally progresses from the inside of cuticular layer in all the outer walls of the long cells, especially in those of the silica cells (Figs. 9-12). As for the parenchyma cells, a large vacuole is formed from an early stage of cell development, and conspicuous invaginations are often seen accompanying with ribosomes (Fig. 13). No lignin is detected in elongating cell walls except those of the protoxylem vesseles. On and after beginning of the secondary wall thickening, M-reaction begins by appearing (Fig. 14A). On and after beginning of the S2 layer thickening, P-reaction follows up the traces of M-reaction. M-reaction decreases in the part where P-reaction is positive (Fig. 14B). In the 4th mature internode, P-reaction is generally intensive in thc epidermis, cortical fibers and small vascular bundle. M-reaction is thc most intensive in the large vascular bundle sheath (Fig. 14C). In a fiber cell, P-reaction is the most intensive in the middle lamella-primary wall complex and decreases centripetally. On the contrary, M-reaction is intensive on the faint parts of P-reaction, but both reactions are not obvious in the parenchyma. In briefly saying, P- and M-reactions relate complementally each other. The secondary wall thickening and the lignin accumulation in the 4th internode of the cultivar terminate about 5 days after heading and entirely complete after next 10 days.

The role of the nuclear protein matrix during development of rabbit gr anulocytes

A proteinaceous nuclear substructure (nuclear protein matrix or nuclear pore complex-lamina) has been described in a number of cells and may be a universal feature of cell nuclei. We have investigated the nuclear protein matrix (NPM) in the rabbit blood granulocyte and its precursor cells to determine (A) whether the NPM composition is similar to other cells that have been studied and (B) to determine whether the dramatic morphological changes that the granulocyte nucleus undergoes during cell maturation are related to changes in the composition or structure of the NPM. NPM preparations from rabbit granulocytes were similar but not identical to those found in HeLa cells or rat liver nuclei. The NPM structure of more mature cells retained more DNA during the isolation procedures than did immature cell NPMs, and the DNA was less accessible to DNAse in the mature cell nuclei. Scanning and transmission electron microscopy revealed a continuous outer covering of the NPM preparation and a lattice-like internal structure. Recognizable nuclear form persisted although the preparations represented less than 20% of the original nuclear protein. NPM preparations from mature cells were similar in overall dimensions and internal structure to NPM from immature cells, suggesting reexpansion during isolation of a previously compacted NPM structure in segmented neutrophils. NPM proteins are synthesized primarily in early stages of cell development. The NPM appears to play a major, but passive, structural role in the nuclear changes observed during maturation of granulocytes.

The Role of the Nuclear Protein Matrix During Development of Rabbit Granulocytes

AbstractA proteinaceous nuclear substructure (nuclear protein matrix or nuclear pore complex-lamina) has been described in a number of cells and may be a universal feature of cell nuclei. We have investigated the nuclear protein matrix (NPM) in the rabbit blood granulocyte and its precursor cells to determine (A) whether the NPM composition is similar to other cells that have been studied and (B) to determine whether the dramatic morphological changes that the granulocyte nucleus undergoes during cell maturation are related to changes in the composition or structure of the NPM. NPM preparations from rabbit granulocytes were similar but not identical to those found in HeLa cells or rat liver nuclei. The NPM structure of more mature cells retained more DNA during the isolation procedures than did immature cell NPMs, and the DNA was less accessible to DNAse in the mature cell nuclei. Scanning and transmission electron microscopy revealed a continuous outer covering of the NPM preparation and a lattice-like internal structure. Recognizable nuclear form persisted although the preparations represented less than 20% of the original nuclear protein. NPM preparations from mature cells were similar in overall dimensions and internal structure to NPM from immature cells, suggesting reexpansion during isolation of a previously compacted NPM structure in segmented neutrophils. NPM proteins are synthesized primarily in early stages of cell development. The NPM appears to play a major, but passive, structural role in the nuclear changes observed during maturation of granulocytes.