Synthesis and Biological Studies of Novel β-Lactams*

2013 ◽  
pp. 53-94 ◽  
Keyword(s):  
Biological Studies

Modification of the Electron Microscope for Investigation of Fully Hydrated Biological Specimens

1969 ◽  
Vol 27 ◽  
pp. 418-419 ◽  
Author(s):  
R. C. Moretz ◽  
D. F. Parsons
Keyword(s):  
Electron Beam ◽  
Electron Microscope ◽  
Structural Damage ◽  
Lower Percentage ◽  
Vacuum Drying ◽  
Total Removal ◽  
Total Absence ◽  
Biological Studies ◽  
Electron Microscopes ◽  
Beam Damage

Short lifetime or total absence of electron diffraction of ordered biological specimens is an indication that the specimen undergoes extensive molecular structural damage in the electron microscope. The specimen damage is due to the interaction of the electron beam (40-100 kV) with the specimen and the total removal of water from the structure by vacuum drying. The lower percentage of inelastic scattering at 1 MeV makes it possible to minimize the beam damage to the specimen. The elimination of vacuum drying by modification of the electron microscope is expected to allow more meaningful investigations of biological specimens at 100 kV until 1 MeV electron microscopes become more readily available. One modification, two-film microchambers, has been explored for both biological and non-biological studies.

Design of Sensitive Photographic Materials for the High-Voltage Electron Microscope

1975 ◽  
Vol 33 ◽  
pp. 156-157
Author(s):  
Murray Vernon King ◽  
Donald F. Parsons
Keyword(s):  
Electron Microscope ◽  
Radiation Damage ◽  
High Voltage ◽  
Radiation Sensitivity ◽  
Fast Electrons ◽  
Voltage Electron ◽  
High Voltage Electron Microscope ◽  
High Voltage Electron ◽  
Biological Studies ◽  
Low Sensitivity

Effective application of the high-voltage electron microscope to a wide variety of biological studies has been restricted by the radiation sensitivity of biological systems. The problem of radiation damage has been recognized as a serious factor influencing the amount of information attainable from biological specimens in electron microscopy at conventional voltages around 100 kV. The problem proves to be even more severe at higher voltages around 1 MV. In this range, the problem is the relatively low sensitivity of the existing recording media, which entails inordinately long exposures that give rise to severe radiation damage. This low sensitivity arises from the small linear energy transfer for fast electrons. Few developable grains are created in the emulsion per electron, while most of the energy of the electrons is wasted in the film base.

Application of stereological analysis of cell volume to isolated myocytes in culture with and without adrenergic innervation

1990 ◽  
Vol 48 (3) ◽  
pp. 416-417
Author(s):  
Jane K. Rosenthal ◽  
Dianne L. Atkins ◽  
William J. Marvin ◽  
Penny A. Krumm
Keyword(s):  
Cardiac Myocytes ◽  
Structural Changes ◽  
Three Dimensional ◽  
Adrenergic Innervation ◽  
Culture Cell ◽  
Serial Sections ◽  
Newborn Rats ◽  
Primary Culture Cell ◽  
Biological Studies ◽  
Cell Volumes

To comprehend structural changes in cardiac myocytes accompanying adrenergic innervation, it is essential that a three dimensional analysis be performed. To date, biological studies which utilize stereological methods have been limited to cells in tissue and in organs. Our laboratory has utilized current stereological techniques for measuring absolute volumes of individual myocytes in primary culture. Cell volumes are calculated for two distinct groups of cells at 96 hours in culture: isolated myocytes and myocytes innervated with adrenergic neurons (Figure 1).Cardiac myocytes are cultured from the ventricular apices of newborn rats. Cells are plated directly onto tissue culture dishes with or without preplated explants from the paravertebral thoracolumbar sympathetic chain. On day four cultures are photographed and marked for one-to-one cell location. Following conventional fixation and embeddment in eponate-12, the cells are relocated and mounted for microtomy. The cells are completely sectioned at 120nm in their parallel orientation to the surface of the dish (Figure 2). Serial sections are collected on formvar coated slotted grids and are recorded in sequence.

Catechin derivatives from Parapiptadenia rigida: biological studies and conformational analysis

Planta Medica ◽  
2010 ◽  
Vol 76 (12) ◽  
Author(s):  
C Schmidt ◽  
M Fronza ◽  
R Murillo ◽  
V Wray ◽  
G Bringmann ◽  
...  
Keyword(s):  
Conformational Analysis ◽  
Biological Studies

Chemical and biological studies on the methanol extract of Gynura pseudochina var. hispida

Planta Medica ◽  
2010 ◽  
Vol 76 (12) ◽  
Author(s):  
N Siriwatanametanon ◽  
J Prieto ◽  
M Heinrich
Keyword(s):  
Methanol Extract ◽  
Biological Studies

Taxonomic characterization and identification of Saccharomyces cerevisiae D8 for brandy production from pineapple

2018 ◽  
Vol 39 (4) ◽  
pp. 474-482
Author(s):  
Hoang Thi Le Thuong ◽  
Nguyen Quang Hao ◽  
Tran Thi Thuy
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Low Ph ◽  
Yeast Strains ◽  
Biological Studies ◽  
Taxonomic Characterization

Eight yeast strains (denoted as D1 to D8) were isolated from samples of natural fermented pineapple. Strain D8 showed highest alcoholic production at low pH and special aroma of pineapple has been chosen for further study. Taxonomic characterization of strain D8 using morphological, biochemical and molecular biological studies confirmed that strain D8  belong to Saccharomycetaceae family, Saccharomycetales order and Saccharomyces cerevisiae species. Therefore, we named this strain as Saccharomyces cerevisiae D8 for further study on Brandy production from pineapple. Citation: Hoang Thi Le Thuong, Nguyen Quang Hao, Tran Thi Thuy, 2017. Taxonomic characterization and identification of Saccharomyces cerevisiae D8 for brandy production from pineapple. Tap chi Sinh hoc, 39(4): 474- 482. DOI: 10.15625/0866-7160/v39n4.10864.*Corresponding author: [email protected] Received 5 December 2016, accepted 12 August 2017

Biological studies on a concrete dam

10.1617/13659 ◽  
2001 ◽  
Vol 34 (242) ◽  
pp. 502-505
Author(s):  
L. P. Traversa
Keyword(s):  
Concrete Dam ◽  
Biological Studies

Xeroderma pigmentosum with diabetes mellitus. A report of 2 cases plus clinical and biological studies of 8 cases of xeroderma pigmentosum occurring in Tokushima.

1988 ◽  
Vol 50 (5) ◽  
pp. 833-838
Author(s):  
Seiji ARASE ◽  
Hideki NAKANISHI ◽  
Atsuo FUJIMOTO ◽  
Hiroaki NAGAE ◽  
Fumio SHIGEMI ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Xeroderma Pigmentosum ◽  
Biological Studies

A Fused Thiophene-S,S-Dioxide-Based Super-Photostable Fluorescent Marker for Lipid Droplets

2020 ◽  
Author(s):  
Masayasu Taki ◽  
Keiji Kajiwara ◽  
Eriko Yamaguchi ◽  
Yoshikatsu Sato ◽  
Shigehiro Yamaguchi
Keyword(s):  
Small Molecules ◽  
Lipid Droplets ◽  
Trajectory Analysis ◽  
Super Resolution ◽  
Fluorescent Marker ◽  
Selective Staining ◽  
Fluorescent Markers ◽  
Biological Studies ◽  
Particle Level

Lipid droplets (LDs) are essential organelle in most eukaryotes, and tracking intracellular LDs dynamics using synthetic small molecules is crucial for biological studies. However, only a limited number of fluorescent markers that satisfy all requirements, such as the selective staining of LDs, high photostability, and sufficient biocompatibility, have been developed. Herein, we report a series of donor-p-acceptor dyes based on the thiophene-containing fused polycyclic scaffold [1]benzothieno[3,2-<i>b</i>][1]benzothiophene (BTBT), in which either or both thiophene rings are oxidized into thiophene-<i>S</i>,<i>S</i>-dioxide to form an electron-accepting building block. Among these dyes, LAQ1 satisfied all the aforementioned requirements, and allowed us capturing ultra-small LDs on the endoplasmic reticulum (ER) membrane by stimulation emission depletion (STED) microscopy with a super-resolution below the diffraction limit of light. Moreover, the extremely high photostability of LAQ1 enabled recording the lipolysis of LDs and the concomitant lipogenesis as well as long-term trajectory analysis of micro LDs at the single particle level in living cells.

Sign in / Sign up

Export Citation Format

Share Document