Morphology of antennae of Dendroctonus vitei (Coleoptera: Curculionidae: Scolytinae), with special reference to sensilla clustered into pit craters

2018 ◽  
Vol 150 (4) ◽  
pp. 471-480 ◽  
Author(s):  
María Fernanda López ◽  
Francisco Armendáriz-Toledano ◽  
Arnulfo Albores-Medina ◽  
Gerardo Zúñiga
Keyword(s):  
Species Complex ◽  
Dendroctonus Frontalis ◽  
Environmental Scanning ◽  
Type I ◽  
Sensilla Basiconica ◽  
The Third ◽  
Transmission Electron ◽  
Inner Surface ◽  
Anterior Side ◽  
Taxonomic Importance

AbstractAs reported recently by the authors, the third and fourth antennomeres of the antennal club of the bark beetle Dendroctonus vitei Wood (Coleoptera: Curculionidae: Scolytinae) possess conoid sensilla clustered inside spherical or bulb-shaped invaginations of the cuticle that resemble geological pit craters. These structures are novel relative to other Dendroctonus Erichson species examined. The morphology and ultrastructure of different sensilla types on the antennal club and within the pit craters of D. vitei are herein described in detail with the aid of light, environmental scanning electron, and transmission electron microscopy. Five types of sensilla were found: fluted, basiconica type I, and trichodea types I, II, and III. The pit craters were composed of clusters of multiporous sensilla basiconica arising from the inner surface of the concavities, and the morphology and ultrasructure of these sensilla are consistent with an olfactory function. The presence of pit craters in the D. vitei on the anterior side of the antennal club is an diagnostic character for this species and an autapomorphy of great taxonomic importance within the Dendroctonus frontalis Zimmermann species complex.

ELECTROLYTIC EXCHANGE FEATURES DURING MYOCARDIAL INFARCTION WITH RECURRENT EPISODES OF ISCHEMIA IN MEN UNDER 60 YEARS OLD

2021 ◽  
pp. 120-126
Author(s):  
Golikov A.V. ◽  
Epifanov S.Yu. ◽  
Reiza V.A.
Keyword(s):  
Myocardial Infarction ◽  
Blood Serum ◽  
Absolute Risk ◽  
Risk Groups ◽  
Unfavorable Outcome ◽  
Study Group ◽  
Type I ◽  
Sodium Potassium ◽  
The Third ◽  
Recurrent Myocardial Infarction

Relevance. Recurrent myocardial infarction and early postinfarction angina negatively effects on the prognosis of myocardial infarction. Aim. To evaluate myocardial infarction sodium, potassium, chlorides, calcium metabolism, features in men under 60 years old with recurrent myocardial infarction and early postinfarction angina to improve prevention and outcomes. Material and methods. The study included men aged 19-60 years old with type I myocardial infarction. Patients are divided into two age-comparable groups: I - the study group, with recurrent myocardial infarction - 110 patients; II - control, without it - 555 patients. A comparative analysis of blood serum electrolyte levels, their dynamics from the first hours to the end of the third week of myocardial infarction in the selected groups were performed. Their impact on the risk of recurrent ischemia and unfavorable outcome was assessed. Results. In the study group, in the first hours of the disease, the levels of chloride were higher (103.7±5.5 and 101.7±4.7 (mmol/l); p=0.002), and total calcium at the end of the third week of myocardial infarction (2.3±0.2 mmol/l) - lower than in the control (2.46±0.16; p=0.001). With an unfavorable outcome in the study group, the sodium level was lower in the first hours of the disease (138.7±4.9 and 142.7±6.6 (mmol/l); p=0.049). Moreover, the risk of its development was associated with sodium levels ≥148.0 mmol/l (absolute risk: 100.0%; relative - 13.8; p<0.0001) and potassium levels ≥5.3 mmol/l (absolute: 71,4%; relative - 12.4; p<0.0001). The risk of developing recurrent episodes of ischemia in the examined increased at chloride levels ≥104.7 mmol/l (absolute: 28.4%; relative: 3.1; p=0.0001) and sodium ≥139.0 mmol/l (absolute: 19.5%; relative: 1.7; p=0.03) in the first hours of myocardial infarction and calcium (<2.4 mmol/l) at the end of the third week of the disease (absolute: 31.0%; relative: 4.9; p=0.003). Conclusions. The listed combinations of levels of basic electrolytes in blood serum are markers of recurrence of ischemia in myocardial infarction and poor outcome. They should be used to identify risk groups with the necessary preventive measures and for predictive modeling.

Collagen Expression in Tissue Engineered Cartilage of Aged Human Articular Chondrocytes in a Rotating Bioreactor

2003 ◽  
Vol 26 (4) ◽  
pp. 319-330 ◽  
Author(s):  
S. Marlovits ◽  
B. Tichy ◽  
M. Truppe ◽  
D. Gruber ◽  
W. Schlegel
Keyword(s):  
Electron Microscopy ◽  
Collagen Type ◽  
Articular Chondrocytes ◽  
Three Dimensional ◽  
Collagen Type I ◽  
Human Articular Chondrocytes ◽  
Type I ◽  
Transmission Electron ◽  
Low Shear Stress ◽  
Engineered Cartilage

This study describes the culture and three-dimensional assembly of aged human articular chondrocytes under controlled oxygenation and low shear stress in a rotating-wall vessel. Chondrocytes cultured in monolayer were released and placed without any scaffold as a single cell suspension in a rotating bioreactor for 12 weeks. Samples were analyzed with immunohistochemistry, molecular biology and electron microscopy. During serial monolayer cultures chondrocytes dedifferentiated to a “fibroblast-like” structure and produced predominantly collagen type I. When these dedifferentiated cells were transferred to the rotating bioreactor, the cells showed a spontaneous aggregation and formation of solid tissue during the culture time. Expression of collagen type II and other components critical for the extracellular cartilage matrix could be detected. Transmission electron microscopy revealed a fine network of randomly distributed collagen fibrils. This rotating bioreactor proves to be a useful tool for providing an environment that enables dedifferentiated chondrocytes to redifferentiate and produce a cartilage-specific extracellular matrix.

Microstructure Imaging, Precipitation Formation and Mechanical Properties: Al–Li and Al–Mg–Zn Alloys

2019 ◽  
Author(s):  
Wilfried Wunderlich ◽  
Janos Lendvai ◽  
Hans-Joachim Gudladt
Keyword(s):  
Hydrogen Embrittlement ◽  
Driving Force ◽  
Hydrogen Diffusion ◽  
Nano Particles ◽  
Peak Hardness ◽  
Free Zone ◽  
The Third ◽  
Transmission Electron ◽  
Moisture Conditions ◽  
Precipitation Formation

This article describes concepts of three features of microstructure–properties relationship, first the imaging and formation of nano-particles, then their contribution to hardness, and finally hydrogen embrittlement during fatigue. First, we briefly review the imaging modes in transmission electron microscopy (TEM) for nano-sized precipitates. The next issue is the hardening in Aluminum alloys, which is caused by GP-zones or precipitates, formed at the second step of the annealing process. After homogenization, the peak-hardness can be generally achieved by a few hours of annealing between 120°C and 200°C. Hardness measurements and equal-channel axial pressing (ECAP) showed that even at room temperature the driving force for formation of the particles is so strong that already within one hour of annealing after homogenization a remarkable hardening occurs. The third issue, hydrogen embrittlement, is caused by oxidation of pure Al surfaces produced at the crack tip during fatigue under ambient or wet moisture conditions. The cracks propagate preferentially along the precipitation free zone adjacent to grain boundaries, where hydrogen diffusion is fastest.

scholarly journals Cellular tropism of SARS-CoV-2 in the respiratory tract of Syrian hamsters and B6.Cg-Tg(K18-ACE2)2Prlmn/J transgenic mice

2021 ◽  
pp. 030098582110430
Author(s):  
Hui-Ling Yen ◽  
Sophie Valkenburg ◽  
Sin Fun Sia ◽  
Ka Tim Choy ◽  
J. S. Malik Peiris ◽  
...  
Keyword(s):  
Transgenic Mice ◽  
Lung Parenchyma ◽  
Productive Infection ◽  
Type I ◽  
Syrian Hamsters ◽  
Transmission Electron ◽  
Type Ii Pneumocytes ◽  
Viral Particles ◽  
Cellular Tropism ◽  
Conducting Airways

Several animal models have been developed to study the pathophysiology of SARS-CoV-2 infection and to evaluate vaccines and therapeutic agents for this emerging disease. Similar to infection with SARS-CoV-1, infection of Syrian hamsters with SARS-CoV-2 results in moderate respiratory disease involving the airways and lung parenchyma but does not lead to increased mortality. Using a combination of immunohistochemistry and transmission electron microscopy, we showed that the epithelium of the conducting airways of hamsters was the primary target for viral infection within the first 5 days of infection, with little evidence of productive infection of pneumocytes. At 6 days postinfection, antigen was cleared but parenchymal damage persisted, and the major pathological changes resolved by day 14. These findings are similar to those previously reported for hamsters with SARS-CoV-1 infection. In contrast, infection of K18-hACE2 transgenic mice resulted in pneumocyte damage, with viral particles and replication complexes in both type I and type II pneumocytes together with the presence of convoluted or cubic membranes; however, there was no evidence of virus replication in the conducting airways. The Syrian hamster is a useful model for the study of SARS-CoV-2 transmission and vaccination strategies, whereas infection of the K18-hCE2 transgenic mouse results in lethal disease with fatal neuroinvasion but with sparing of conducting airways.

Aromatase Inhibitors in the Treatment and Prevention of Breast Cancer

2001 ◽  
Vol 19 (3) ◽  
pp. 881-894 ◽  
Author(s):  
Paul E. Goss ◽  
Kathrin Strasser
Keyword(s):  
Breast Cancer ◽  
Aromatase Inhibitors ◽  
Clinical Status ◽  
Phase Iii ◽  
Type I ◽  
Third Generation ◽  
Line Treatment ◽  
Second Line ◽  
First Line ◽  
The Third

PURPOSE: The purpose of this article is to provide an overview of the current clinical status and possible future applications of aromatase inhibitors in breast cancer. METHODS: A review of the literature on the third-generation aromatase inhibitors was conducted. Some data that have been presented but not published are included. In addition, the designs of ongoing trials with aromatase inhibitors are outlined and the implications of possible results discussed. RESULTS: All of the third-generation oral aromatase inhibitors—letrozole, anastrozole, and vorozole (nonsteroidal, type II) and exemestane (steroidal, type I)—have now been tested in phase III trials as second-line treatment of postmenopausal hormone-dependent breast cancer. They have shown clear superiority compared with the conventional therapies and are therefore considered established second-line hormonal agents. Currently, they are being tested as first-line therapy in the metastatic, adjuvant, and neoadjuvant settings. Preliminary results suggest that the inhibitors might displace tamoxifen as first-line treatment, but further studies are needed to determine this. CONCLUSION: The role of aromatase inhibitors in premenopausal breast cancer and in combination with chemotherapy and other anticancer treatments are areas of future exploration. The ongoing adjuvant trials will provide important data on the long-term safety of aromatase inhibitors, which will help to determine their suitability for use as chemopreventives in healthy women at risk of developing breast cancer.

scholarly journals Submicroscopical Features of Leaves of Xyris Species

2001 ◽  
Vol 44 (4) ◽  
pp. 405-410 ◽  
Author(s):  
Maria das Graças Sajo ◽  
Silvia Rodrigues Machado
Keyword(s):  
Electron Microscope ◽  
Cell Walls ◽  
Guard Cells ◽  
Leaf Ultrastructure ◽  
Mesophyll Cells ◽  
Transmission Electron ◽  
Inner Surface ◽  
Stomatal Guard Cells ◽  
Adaptative Significance ◽  
Scanning Electron

The leaf ultrastructure of five Xyris species were examined using scanning electron microscope (SEM), transmission electron microscope (TEM) and histochemical methods. All studied leaves show some features in epidermis and mesophyll, which were of considerable adaptative significance to drought stress. Such features included the occurrence of a pectic layer on the stomatal guard cells and the presence of a network of pectic compounds in the cuticle. Pectic compunds were also in abundance in lamellated walls of the mesophyll cells and on the inner surface of the sclerified cell walls of the vascular bundle sheaths. There were also specialized chlorenchymatous "peg cells" in the mesophyll and drops of phenolic compounds inside the epidermal cells.

scholarly journals Gliocyte and synapse analyses in cerebral ganglia of the Chinese mitten crab, Eriocheir sinensis: ultrastructural study

2016 ◽  
Author(s):  
H. Zhang ◽  
P. Yu ◽  
S. Zhong ◽  
T. Ge ◽  
S. Peng ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Eriocheir Sinensis ◽  
Type I ◽  
Aquatic Species ◽  
Histological Findings ◽  
Chinese Mitten Crab ◽  
Cerebral Ganglia ◽  
Transmission Electron ◽  
Mitten Crab ◽  
Nerve System

The Chinese mitten crab Eriocheir sinensis is an economically important aquatic species in China. Many studies on gene structure, breeding, and diseases of the crab have been reported. However, knowledge about the organization of the nerve system of the crab remains largely unknown. To study the ultrastructure of the cerebral ganglia of E. sinensis and to compare the histological findings regarding the nerve systems of crustaceans, the cerebral ganglia were observed by transmission electron microscopy. The results showed that four types of gliocytes, including type I, II, III, and IV gliocytes were located in the cerebral ganglia. In addition, three types of synapses were present in the cerebral ganglia, including unidirectional synapses, bidirectional synapses, and combined type synapses. 

Uncovering the ultrastructure of ramiform pits in the parenchyma cells of bamboo [Phyllostachys edulis (Carr.) J. Houz.]

Holzforschung ◽  
2020 ◽  
Vol 74 (3) ◽  
pp. 321-331 ◽  
Author(s):  
Caiping Lian ◽  
Shuqin Zhang ◽  
Xianmiao Liu ◽  
Junji Luo ◽  
Feng Yang ◽  
...  
Keyword(s):  
Environmental Scanning Electron Microscopy ◽  
Environmental Scanning ◽  
Type I ◽  
Aperture Diameter ◽  
Parenchyma Cells ◽  
Vascular Parenchyma ◽  
Function Relationship ◽  
Relationship Of ◽  
Important Evidence

AbstractPits are the main transverse channels of intercellular liquid transport in bamboo. Ramiform pits are a special type of simple pit with two or more branches. However, little is known about the morphology and physiological functions of ramiform pits. The anatomy of plants can provide important evidence for the role of cells. To better understand the ultrastructure and the structure-function relationship of ramiform pits, their characteristics need to be investigated. In this study, both qualitative and quantitative features of ramiform pits were studied using field-emission environmental scanning electron microscopy (FE-ESEM). The samples included the native structures and the replica structures obtained by resin castings. The results show that the ramiform pits have a diverse morphology that can be divided into main categories: type I (the primary branches) and type II (the secondary branches). The distribution of ramiform pits is different in ground parenchyma cells (GPCs) and vascular parenchyma cells (VPCs). The number, the pit aperture diameter and the pit canal length of ramiform pits in the VPCs were, respectively, greater (3-fold), larger (2–3-fold) and shorter (1.3-fold) than those in the GPCs.

Formation and Properties of Porous Si Superlattices

1994 ◽  
Vol 358 ◽  
Author(s):  
M.G. Berger ◽  
R. Arens-Fischer ◽  
St. Frohnhoff ◽  
C. Dieker ◽  
K. Winz ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Doping Level ◽  
Layer Structure ◽  
Optical Data ◽  
Type I ◽  
Optical Components ◽  
Porous Layers ◽  
Long Term Stability ◽  
Transmission Electron

ABSTRACTPorous silicon superlattices (PS-SL) were investigated by transmission electron microscopy (TEM), scanning electron microscopy (SEM), spectroscopic ellipsometry and reflectance spectroscopy. Type I superlattices were formed by periodically changing the current density during the etch process. The quality of the interface between layers of different porosity depends on the quality of the silicon substrate. Optical components such as Bragg reflectors or Fabry-Perot filters were designed using the optical data of single porous layers. A good long term stability of the layers is achieved by using thermal oxidation steps. Type II superlattices were formed on substrates with layers of alternating doping level. The more complex layer structure of these superlattices is explained by the selectivity of the etch process on the doping level.

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