scholarly journals Evaluation of Operability of the PhaSeal system, a Sealed Handling Device for Anticancer Agents

2006 ◽  
Vol 32 (12) ◽  
pp. 1211-1221 ◽  
Author(s):  
Hironobu Miyamatsu ◽  
Masumi Sakamoto ◽  
Kanako Azuma ◽  
Fumio Ishii ◽  
Akira Mae ◽  
...  
Keyword(s):  
Anticancer Agents ◽  
System A ◽  
Handling Device

scholarly journals Efficient Isolation and Structure Analysis of (+)-Ranuncoside, a Unique Tricyclic Spiroacetal Glycoside, from Christmas Rose (Helleborus niger L.)

2022 ◽  
Vol 17 (1) ◽  
pp. 1934578X2110694
Author(s):  
Eckehard Cuny ◽  
Franz-Dietrich Klingler
Keyword(s):  
Structure Analysis ◽  
Anticancer Agents ◽  
Structure Activity Relationship ◽  
Activity Relationship ◽  
System A ◽  
Structure Activity ◽  
First Time ◽  
Absolute Stereochemistry ◽  
Helleborus Niger ◽  
Christmas Rose

The use of medicinal herbs as remedies reaches back to the Stone Age, and their importance as a source of drugs has continuously increased since then. Herbal ingredients can serve as active pharmaceuticals themselves or as lead substances for the development of synthetic pharmaceuticals with less toxicity, higher effectiveness or with new properties. To date, only 6% of the ∼600,000 plants on earth have been tested pharmacologically. Among these, the medicinal plant Helleborus niger L. (Christmas rose) is especially promising because its leaves contain ( + )-ranuncoside 1, characterized by a spiroacetal ring system, a motif which is responsible for the biological activity of a multitude of natural products. Structure-activity relationship studies of ( + )-ranuncoside 1 are lacking and no synthesis of 1 has been described yet. Therefore, we developed a protocol for the rapid and efficient isolation of 1 from the leaves of cultivated Christmas rose. Crystals of high purity were obtained that enabled us to study the stereochemistry of 1 by NMR spectroscopy in solution for the first time. The spiro configuration, the absolute stereochemistry, and the geometry of all three rings was then confirmed by x-ray structure analysis. Our data will enable future structure-activity relationship studies to assess the potential of 1 as a lead substance for the development of novel antibiotics and anticancer agents.

Feasibility Study of a Novel Micro-Handling Device Based on Smart Materials

2007 ◽  
Author(s):  
Claudia Pagano ◽  
Irene Fassi
Keyword(s):  
Feasibility Study ◽  
Smart Materials ◽  
High Surface ◽  
Volume Ratio ◽  
System A ◽  
Reduced Dimensions ◽  
Variable Curvature ◽  
Good Ability ◽  
Handling Device ◽  
Manipulation System

Due to their high surface to volume ratio, microsystems are characterized by great superficial forces, which become dominant with respect to inertial ones. Superficial interactions influence fabrication processes as well as working conditions of microsystems and make most of the techniques used at the macrolevel inadequate at the microlevel. In particular, the traditional manipulation techniques are often not suitable for the fabrication of hybrid microsystems and the development of new handling techniques for microcomponents is strongly required. This has aimed a large number of recent studies that have been addressed the possibilities of controlling and exploiting superficial forces in order to manipulate microobjects. In this context, this paper is focused on a new handling system based on the capillary force; in particular, it concerns the first investigations on the use of smart materials for the realization of an innovative manipulation system. A gripper with variable curvature has been theoretically studied and a first prototype has been developed. It has demo good ability in performing accurate pick & place operations of component of the millimetric size. The results obtained from this prototype have, then, encouraged the development of a smaller prototype, able to manipulate objects with micrometric size. Due to the reduced dimensions of the prototype, smart materials have been considered suitable for the actuation of such a gripper. Therefore, different materials and configurations have been conceived and a novel configuration based on electroactive polymers (EAP) has been studied. A feasibility study has been carried out in order to evaluate their functionality and performances as actuator and the results are presented.

scholarly journals Nanoparticle-Based Drug Delivery System: A Patient-Friendly Chemotherapy for Oncology

Dose-Response ◽  
2020 ◽  
Vol 18 (3) ◽  
pp. 155932582093616 ◽  
Author(s):  
Lina Yan ◽  
Jingjing Shen ◽  
Jinqiao Wang ◽  
Xiaoyan Yang ◽  
Shiyan Dong ◽  
...  
Keyword(s):  
Side Effects ◽  
Anticancer Agents ◽  
Chemotherapeutic Agents ◽  
Chemotherapeutic Drugs ◽  
Conventional Chemotherapy ◽  
Killing Effect ◽  
Advantages And Disadvantages ◽  
System A ◽  
Stage Of Development ◽  
Different Types

Chemotherapy is widely used to treat cancer. The toxic effect of conventional chemotherapeutic drugs on healthy cells leads to serious toxic and side effects of conventional chemotherapy. The application of nanotechnology in tumor chemotherapy can increase the specificity of anticancer agents, increase the killing effect of tumors, and reduce toxic and side effects. Currently, a variety of formulations based on nanoparticles (NPs) for delivering chemotherapeutic drugs have been put into clinical use, and several others are in the stage of development or clinical trials. In this review, after briefly introducing current cancer chemotherapeutic methods and their limitations, we describe the clinical applications and advantages and disadvantages of several different types of NPs-based chemotherapeutic agents. We have summarized a lot of information in tables and figures related to the delivery of chemotherapeutic drugs based on NPs and the design of NPs with active targeting capabilities.

New Design for a Differentially Pumped Hydration Chamber for a Siemens IA

1971 ◽  
Vol 29 ◽  
pp. 44-45
Author(s):  
R. C. Moretz ◽  
G. G. Hausner ◽  
D. F. Parsons
Keyword(s):  
Electron Microscopy ◽  
Water Vapor ◽  
Electron Diffraction ◽  
Water Vapor Pressure ◽  
Biological Materials ◽  
Thin Membrane ◽  
Reliable System ◽  
System A ◽  
Water Films ◽  
Aperture Opening

Electron microscopy and diffraction of biological materials in the hydrated state requires the construction of a chamber in which the water vapor pressure can be maintained at saturation for a given specimen temperature, while minimally affecting the normal vacuum of the remainder of the microscope column. Initial studies with chambers closed by thin membrane windows showed that at the film thicknesses required for electron diffraction at 100 KV the window failure rate was too high to give a reliable system. A single stage, differentially pumped specimen hydration chamber was constructed, consisting of two apertures (70-100μ), which eliminated the necessity of thin membrane windows. This system was used to obtain electron diffraction and electron microscopy of water droplets and thin water films. However, a period of dehydration occurred during initial pumping of the microscope column. Although rehydration occurred within five minutes, biological materials were irreversibly damaged. Another limitation of this system was that the specimen grid was clamped between the apertures, thus limiting the yield of view to the aperture opening.

High-resolution electron microscopy of Cu2O surfaces

1986 ◽  
Vol 44 ◽  
pp. 396-397
Author(s):  
V. Castano ◽  
W. Krakow
Keyword(s):  
High Resolution ◽  
Natural Extension ◽  
High Resolution Electron Microscopy ◽  
Point Of View ◽  
Initial Oxidation ◽  
System A ◽  
Resolution Electron ◽  
Surface Reconstructions ◽  
Atomic Surface ◽  
Au Thin Films

In non-UHV microscope environments atomic surface structure has been observed for flat-on for various orientations of Au thin films and edge-on for columns of atoms in small particles. The problem of oxidation of surfaces has only recently been reported from the point of view of high resolution microscopy revealing surface reconstructions for the Ag2O system. A natural extension of these initial oxidation studies is to explore other materials areas which are technologically more significant such as that of Cu2O, which will now be described.

Twin boundary structure of a Y-Ba-Cu-O superconductor

1989 ◽  
Vol 47 ◽  
pp. 168-169
Author(s):  
Yimei Zhu ◽  
Masaki Suenaga ◽  
R. L. Sabatini ◽  
Youwen Xu
Keyword(s):  
Twin Boundary ◽  
Fine Particles ◽  
Imaging Techniques ◽  
Fine Powder ◽  
Orthorhombic Phase ◽  
Boundary Structure ◽  
Crystallographic Axis ◽  
System A ◽  
High Resolution Structure ◽  
Electron Microscopes

The (110) twin structure of YBa2Cu3O7 superconductor oxide, which is formed to reduce the strain energy of the tetragonal to orthorhombic phase transformation by alternating the a-b crystallographic axis across the boundary, was extensively investigated. Up to now the structure of the twin boundary still remained unclear. In order to gain insight into the nature of the twin boundary in Y-Ba-Cu-O system, a study using electron diffraction techniques including optical and computed diffractograms, as well as high resolution structure imaging techniques with corresponding computer simulation and processing was initiated.Bulk samples of Y-Ba-Cu-O oxide were prepared as described elsewhere. TEM specimens were produced by crushing bulk samples into a fine powder, dispersing the powder in acetone, and suspending the fine particles on a holey carbon grid. The electron microscopy during this study was performed on both a JEOL 2000EX and 2000FX electron microscopes operated at 200 kV.

Speech Therapy Services in a Large School System: A Six-Year Overview

1976 ◽  
Vol 7 (4) ◽  
pp. 207-219 ◽  
Author(s):  
Constance P. DesRoches
Keyword(s):  
School System ◽  
Speech Therapy ◽  
Factors Affecting ◽  
Case Load ◽  
Number Of Children ◽  
School Population ◽  
System A ◽  
Therapy Services ◽  
And Shifts ◽  
Selection Factors

A statistical review provides analysis of four years of speech therapy services of a suburban school system which can be used for comparison with other school system programs. Included are data on the percentages of the school population enrolled in therapy, the categories of disabilities and the number of children in each category, the sex and grade-level distribution of those in therapy, and shifts in case-load selection. Factors affecting changes in case-load profiles are identified and discussed.

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