Recoltare celule stem

Banci de celule stem

Despre Celule Stem

Ce sunt celulele stem?

Definitie


Celula stem este definita ca o celula care, prin diviziune mitotica, produce doua celule ce au capacitatea de a ramane an stadiul de celula stem (pastrand astfel caracterul nediferentiat) sau de a se diferentia in urma unor diviziuni succesive.

In acest fel, celula stem se poate divide fie simetric, caz in care rezulta doua noi celule stem sau doua celule diferentiate fie asimetric, rezultand o celula stem si o celula diferentiata .
Capacitatea celulei stem de a da nastere unei celule identice se numeste auto-innoire (self-renewal in limba engleza), iar cea de a da nastere altor tipuri de celule se numeste diferentiere.

Celulele stem au remarcabila capacitate de a se dezvolta in mai multe tipuri de celule ale organismului.Celulele stem se pot imparti in doua mari categorii: embrionare si adulte.Celulele stem embrionare pot da nastere oricarui alt tip de celula/tesut, si pot fi obtinute din tesut embrionar.

.

Clasificare


Dupa originea de recoltare a celulelor stem, acestea se impart in:

- celule stem embrionare: fac referire in special la celulele stem totipotente si pluripotente

- celule stem fetale: se limiteaza la celule stem pluripotente

- celule stem adulte: includ celule stem multipotente, oligopotente si unipotente.

La adultii celule stem se mai gasesc in inima, creier, oase, plamani si alte organe. Sunt rezerva noastra pentru regenerarea celulelor distruse de boli din organism.

Initial se credea ca celule stem adulte sunt cu mult mai limitate in posibilitati decat cele embrionare si ca ar da nastere doar la tesuturi de tipul celor din care provin, dar noile cercetari ne indica faptul ca celulele stem adulte pot genera si alte tipuri de tesuturi . De exemplu, celulele hepatice pot fi folosite pentru producerea de insulina, care de obicei este creata de pancreas. Aceasta capacitate este cunoscuta ca plasticitate sau transdiferentiere.

Celulele Stem Embrionare au abilitatea de a se dezvolta in mai multe tipuri diferite de celule, cu risc minor de contaminare.

Totusi, exista un numar de dezbateri etice care vizeaza acest tip de obtinere de celule stem embrionare Celule Stem Adulte care se gasesc in maduva si in sangele periferic au de asemenea capacitatea de a se transforma in alte tipuri de celule, dar sunt mai greu de obtinut, si din cauza faptului ca celulele sunt imbatranite exista un risc mai mare ca acestea sa fie respinse de gazda.

Generalitati


Descoperirea metodelor de izolare si cultivare a celulelor stem in 1998 a adus o noua speranta cercetatorilor si medicilor din lumea intreaga.

Transplantul de celule stem poate vindeca in momentul de fata peste 70 de boli, iar medicina este in plin progres.

Boli precum Alzheimer, atrofii musculare, leucemii, cancere si alte boli pot fi tratatate cu celule stem, iar cercetatorii studiaza acum tratamentul cu celule stem in bolile mostenite.

Celulele stem embrionare au rolul de a se transforma in celule specializate din care se va forma embrionul, iar mai apoi fetusul.

Cele din cordonul ombilical sunt celule multipotente care se pot diferentia intr-un numar limitat de celule specializate si pot fi prelevate si conservate dupa nasterea fatului. Celulele stem adulte se gasesc atat la adult, cat si la copil si au rolul de a inlocui celulele distruse sau moarte cu altele noi.

HTML and CSS Code

HTML

The HTML is coded using XHTML 1.0 Strict. Four files are available, "index.html" containing the overview, "mf54_grid.html" the grid styles, "mf54_content.html" the content styles and "mf54_tutorial.html" the tutorial.

A special feature which makes Multiflex really flexible is that the HTML-tag coding is uniform throughout the entire content and subcontent sections. In other words, the HTML data has identical coding, and can thus easily be moved from one part of the template to another without having to change the tags. All examples given in Content Toolbox (with sidebar) and in Content Toolbox (without sidebar) use the absolutely identical HTML code, regardless of their grid (layout) positions.

CSS

The CSS is coded using CSS 2.0. Three files are available, "mf54_reset.css" resetting all CSS parameters to a common value in order to reduce cross-browser inconsisttencies, "mf54_grid.css" and "mf54_grid_nosidebar.css" define the grid styles, while "mf54_content.css" and "mf54_content_nosidebar.css" define the content styles.

Browsers

Multiflex-5 has been tested successfully for Firefox, Opera, Netscape, Safari and Internet Explorer. The template is highly robust and stable, and works safely in any modern browser environment.

Toolboxes

Grid Toolbox

The Grid Toolbox is the tool with which the basic grid structure is constructed. This serves as the backbone of the template. Go to the Grid Toolbox (with sidebar) or Grid Toolbox (without sidebar) to see the available styles.

Content Toolbox

The Content Toolbox is the tool with which you fill the grid with actual text, image, audio or video content. Go to the Content Toolbox (with sidebar) or Grid Toolbox (without sidebar) to see the available styles.

Template Packages

Basic Template Package

The Basic Template Package contains all the necessary HTML, CSS and image files. This corresponds to the package version available at typical open source webdesign sites. If you downloaded your package from such a site, this is most probably the package you received.

If you don't care about offering audio and video content on your site, this package is all you need! The package does not contain any files needed for media content presentation or modification of original graphics files.

Installation instructions
  • Download (File size: 70 KB)
  • Unzip the file "mf54_basic.zip".
  • To build your webpage, follow the instructions in Getting Started.

Full Template Package

The Full Template Package is an all-in-one package containing all files related to Multiflex-5, that is, the Basic Template Package, the Media Package and the Graphics Package. Here you have the option of also using audio and video content on your website. When unzipping the file, all files necessary for audio and media content are automatically installed in the right place.

Installation instructions
  • Download (File size: 11.9 MB)
  • Unzip the file "mf54_full.zip".
  • To build your webpage, follow the instructions in Getting Started.

Media Package

The Media Package is of interest to those persons who downloaded or have built their website using the Basic Template Package, but now would like to include audio and video content as well. The Media Package includes all the necessary files to get your media content going. As for the HTML coding, all necessary code is already in place in the Basic Template Package. The Media Package supplies the extra files needed for the flash player.

Installation instructions
  • Download (File size: 11.0 MB)
  • Unzip the file "mf54_media.zip" into the folder where your HTML files are located.
  • You should see three new directories, namely "media", "source" and ".svn".
  • You should see one new file, namely "mediaplayer.swf".
  • The directory "media" contains an audio and two video demo files (FLV and MP4), and one image preview file. This is also where you put your own media files and preview images.
  • The flash player works for users having Adobe Flash Player 9.0 or higher, which corresponds to about 90% of the global web surfers.
  • You are now ready to play media content.
Playable file formats

The media player can play the file formats MP3, SWF, FLV and MP4 (H.264). Please note that MP4 files must be encoded in H.264. Playback of MP4 files is only possible for users having Adobe Flash Player 9.0.115.0 or later installed.

Streaming

The MP3, SWF and FLV files immediately start playing in streaming mode, while MP4 playback waits until the entire file has been downloaded. However, the player can also be put in streaming-mode for MP4 files. Check Wijering's Media Player Setup Wizard to get the informations you need.

Further options

When the Javascript version of the media player is used, there are lots of additional options such as playlists and other effects. See a remarkable Media Player demo site with many examples.

Graphics Package

The Graphics Package is of interest to those persons who want to modify some or all of the graphical elements used in Multiflex-5. For this reason, files are offered in the original Corel, Adobe Photoshop or high-resolution PNG graphics formats.

Installation instructions
  • Download (File size: 0.8 MB)
  • Unzip the file "mf54_graphics.zip" to any location you prefer.
  • Edit the graphics according to your needs.

Solicita Oferta

Oferta prelevare celule stem

preturi costuri tarife recoltare