Plasma-jet systems - experiment and model

In the present work we study the ow of working gas through a plasmajet system. In this work we describe the basic principle of hollow cathode discharge and its use for technological applications, mainly for thin layers coating. One of the important parameters during the deposition is the speed of the working gas ow and with it the sputtered target material towards the substrate. Because of the reproducibility and precision of the experiments it is important to know the relation between the working gas ow and external parameters of the experiment, e.g. ow of the gas and the pressure in the chamber. This is the reason why measurements of ions velocity using Langmuire electrostatic probe and pulse regime of plasmajet were done. Measured data are compared with a computer model, which was developed in this work. This model describes the ow of the working gas by solving Navier-Stokes equation for compressible Newtonian uids. The results of this model are compared with results from the paper describing the ow through the hollow cathode. It shows good agreement inside the cathode. The model is giving dierent results when comparing to measured data which are from the area outside the cathode. Part of the model description is a discussion of the temperature dependence of the ow

Synthesis and Biological Evaluation of Epidithio‑, Epitetrathio‑, and bis-(Methylthio)diketopiperazines: Synthetic Methodology, Enantioselective Total Synthesis of Epicoccin G, 8,8′-<i>epi</i>-<i>ent</i>-Rostratin B, Gliotoxin, Gliotoxin G, Emethallicin E, and Haematocin and Discovery of New Antiviral and Antimalarial Agents

An improved sulfenylation method for the preparation of epidithio-, epitetrathio-, and bis-(methylthio)­diketopiperazines from diketopiperazines has been developed. Employing NaHMDS and related bases and elemental sulfur or bis­[bis­(trimethylsilyl)­amino]­trisulfide (<b>23</b>) in THF, the developed method was applied to the synthesis of a series of natural and designed molecules, including epicoccin G (<b>1</b>), 8,8′-<i>epi</i>-<i>ent</i>-rostratin B (<b>2</b>), gliotoxin (<b>3</b>), gliotoxin G (<b>4</b>), emethallicin E (<b>5</b>), and haematocin (<b>6</b>). Biological screening of selected synthesized compounds led to the discovery of a number of nanomolar antipoliovirus agents (i.e., <b>46</b>, 2,2′-<i>epi</i>-<b>46</b>, and <b>61</b>) and several low-micromolar anti-Plasmodium falciparum lead compounds (i.e., <b>46</b>, 2,2′-<i>epi</i>-<b>46</b>, <b>58</b>, <b>61</b>, and <b>1</b>)

Synthesis and Biological Evaluation of Epidithio‑, Epitetrathio‑, and bis-(Methylthio)diketopiperazines: Synthetic Methodology, Enantioselective Total Synthesis of Epicoccin G, 8,8′-<i>epi</i>-<i>ent</i>-Rostratin B, Gliotoxin, Gliotoxin G, Emethallicin E, and Haematocin and Discovery of New Antiviral and Antimalarial Agents

An improved sulfenylation method for the preparation of epidithio-, epitetrathio-, and bis-(methylthio)­diketopiperazines from diketopiperazines has been developed. Employing NaHMDS and related bases and elemental sulfur or bis­[bis­(trimethylsilyl)­amino]­trisulfide (<b>23</b>) in THF, the developed method was applied to the synthesis of a series of natural and designed molecules, including epicoccin G (<b>1</b>), 8,8′-<i>epi</i>-<i>ent</i>-rostratin B (<b>2</b>), gliotoxin (<b>3</b>), gliotoxin G (<b>4</b>), emethallicin E (<b>5</b>), and haematocin (<b>6</b>). Biological screening of selected synthesized compounds led to the discovery of a number of nanomolar antipoliovirus agents (i.e., <b>46</b>, 2,2′-<i>epi</i>-<b>46</b>, and <b>61</b>) and several low-micromolar anti-Plasmodium falciparum lead compounds (i.e., <b>46</b>, 2,2′-<i>epi</i>-<b>46</b>, <b>58</b>, <b>61</b>, and <b>1</b>)

Synthesis and Biological Evaluation of Epidithio‑, Epitetrathio‑, and bis-(Methylthio)diketopiperazines: Synthetic Methodology, Enantioselective Total Synthesis of Epicoccin G, 8,8′-<i>epi</i>-<i>ent</i>-Rostratin B, Gliotoxin, Gliotoxin G, Emethallicin E, and Haematocin and Discovery of New Antiviral and Antimalarial Agents

An improved sulfenylation method for the preparation of epidithio-, epitetrathio-, and bis-(methylthio)­diketopiperazines from diketopiperazines has been developed. Employing NaHMDS and related bases and elemental sulfur or bis­[bis­(trimethylsilyl)­amino]­trisulfide (<b>23</b>) in THF, the developed method was applied to the synthesis of a series of natural and designed molecules, including epicoccin G (<b>1</b>), 8,8′-<i>epi</i>-<i>ent</i>-rostratin B (<b>2</b>), gliotoxin (<b>3</b>), gliotoxin G (<b>4</b>), emethallicin E (<b>5</b>), and haematocin (<b>6</b>). Biological screening of selected synthesized compounds led to the discovery of a number of nanomolar antipoliovirus agents (i.e., <b>46</b>, 2,2′-<i>epi</i>-<b>46</b>, and <b>61</b>) and several low-micromolar anti-Plasmodium falciparum lead compounds (i.e., <b>46</b>, 2,2′-<i>epi</i>-<b>46</b>, <b>58</b>, <b>61</b>, and <b>1</b>)

Synthesis and Biological Evaluation of Epidithio‑, Epitetrathio‑, and bis-(Methylthio)diketopiperazines: Synthetic Methodology, Enantioselective Total Synthesis of Epicoccin G, 8,8′-<i>epi</i>-<i>ent</i>-Rostratin B, Gliotoxin, Gliotoxin G, Emethallicin E, and Haematocin and Discovery of New Antiviral and Antimalarial Agents

An improved sulfenylation method for the preparation of epidithio-, epitetrathio-, and bis-(methylthio)­diketopiperazines from diketopiperazines has been developed. Employing NaHMDS and related bases and elemental sulfur or bis­[bis­(trimethylsilyl)­amino]­trisulfide (<b>23</b>) in THF, the developed method was applied to the synthesis of a series of natural and designed molecules, including epicoccin G (<b>1</b>), 8,8′-<i>epi</i>-<i>ent</i>-rostratin B (<b>2</b>), gliotoxin (<b>3</b>), gliotoxin G (<b>4</b>), emethallicin E (<b>5</b>), and haematocin (<b>6</b>). Biological screening of selected synthesized compounds led to the discovery of a number of nanomolar antipoliovirus agents (i.e., <b>46</b>, 2,2′-<i>epi</i>-<b>46</b>, and <b>61</b>) and several low-micromolar anti-Plasmodium falciparum lead compounds (i.e., <b>46</b>, 2,2′-<i>epi</i>-<b>46</b>, <b>58</b>, <b>61</b>, and <b>1</b>)

Synthesis and Biological Evaluation of Epidithio‑, Epitetrathio‑, and bis-(Methylthio)diketopiperazines: Synthetic Methodology, Enantioselective Total Synthesis of Epicoccin G, 8,8′-<i>epi</i>-<i>ent</i>-Rostratin B, Gliotoxin, Gliotoxin G, Emethallicin E, and Haematocin and Discovery of New Antiviral and Antimalarial Agents

An improved sulfenylation method for the preparation of epidithio-, epitetrathio-, and bis-(methylthio)­diketopiperazines from diketopiperazines has been developed. Employing NaHMDS and related bases and elemental sulfur or bis­[bis­(trimethylsilyl)­amino]­trisulfide (<b>23</b>) in THF, the developed method was applied to the synthesis of a series of natural and designed molecules, including epicoccin G (<b>1</b>), 8,8′-<i>epi</i>-<i>ent</i>-rostratin B (<b>2</b>), gliotoxin (<b>3</b>), gliotoxin G (<b>4</b>), emethallicin E (<b>5</b>), and haematocin (<b>6</b>). Biological screening of selected synthesized compounds led to the discovery of a number of nanomolar antipoliovirus agents (i.e., <b>46</b>, 2,2′-<i>epi</i>-<b>46</b>, and <b>61</b>) and several low-micromolar anti-Plasmodium falciparum lead compounds (i.e., <b>46</b>, 2,2′-<i>epi</i>-<b>46</b>, <b>58</b>, <b>61</b>, and <b>1</b>)