Longevity of preserved Solanum lycopersicum L. seeds: physicochemical characteristics.

Ex situ conservation of plant biodiversity has been increasingly used to prevent further loss of genetic resources. Seed banks, for example, shelter the passport data of germplasm, preserved in detail, and made available for easy access, actions included in the FAO's Second Global Plan. We examined the deterioration of tomato seeds of different varieties stored for 10-year intervals at COMAV's genebank. Samples were analyzed using the conventional Germination and Tetrazolium tests, as well as the non-conventional Differential Scanning Calorimetry and Fourier Transform Infrared Spectrometry techniques, to quickly identify the physiological status of the accessions. Fatty acid profile was also determined. The relationship observed between lipid behavior and seed deterioration under long time storage conditions was the same for both non-conventional and conventional techniques. The viability of the samples was not affected by storage time, however, all the employed methods permitted identifying differences between varieties or accessions of the same variety. The complementary methods helped us interpret a complex data set with many interacting factors, leading to rapid identification of seed quality, increasing processing efficiency in tomato seeds conservation. Supplementary Information: The online version contains supplementary material available at 10.1007/s12298-022-01157-9.

Modeling of electron-cyclotron-resonance-heated plasmas

This article describes the behavior of electron-cyclotron-resonance-heated plasmas, with particular attention paid to mirror-confined plasmas, which are of great interest in plasma processing and in highly charged ion production. Using a one-dimensional (in velocity) description of the electron distribution function, we calculate the electron density and confinement time. The theoretical results are compared with experiments, and it is shown that a maximum critical density can be achieved in such plasmas.

Polymerase-chain-reaction-based semi-quantification of hepatitis D viraemia in patients treated with high doses of alpha 2b interferon.

To study the antiviral efficacy of high doses of alpha 2b interferon (alpha 2b-IFN) for chronic hepatitis D treatment, we used polymerase-chain-reaction(PCR)-based semi-quantitative detection of HDV RNA. The semi-quantification method used was based on the appearance of a positive amplification signal as a function of the number of PCR cycles. By amplifying dilutions (10(-1)-10(-8)) of an HDV-positive woodchuck liver RNA, we confirmed that exponential amplification efficacy occurred at between 20 and 30 cycles. Positive signals were observed from dilution 10(-2) (gel electrophoresis after 20 cycles of PCR) to dilution 10(-7) (hybridization after 30 cycles of PCR). To characterize the HDV RNA level in sera of 8 patients treated with alpha 2b-IFN (10 MU/3 times a week) for 1 year, we extracted RNA from serum samples taken every 6 months. All samples were amplified in parallel for 20 and 30 PCR cycles. Analysis of HDV cDNA after ethidium bromide/agarose gel electrophoresis and after molecular hybridization (100 times more sensitive than gel analysis), enabled us to grade the signals observed from negative to positive as 1+, 2+, 3+ and 4+, with all results being positive. Three types of evolution of HDV viraemia were evidenced among the 8 treated patients. HDV replication continued to occur at a high level at the 6th and 12th month in 2 patient sera. For 2 other patients, an HDV RNA decrease or disappearance was evidenced in the serum at the 6th month; however, viral replication recurred at a higher level at the 12th month.(ABSTRACT TRUNCATED AT 250 WORDS)

Polymerase chain reaction-based detection of hepatitis D virus genome in patients infected with human immunodeficiency virus.

The polymerase chain reaction (PCR) was used to detect hepatitis D (HD) viremia in patients infected with the human immunodeficiency virus (HIV). Nineteen (9%) of 206 such patients, unselected for liver disease or HBV infection, were found prospectively to be infected by HDV. Thirty-one anti-HIV-positive patients were studied by means of PCR, and the results were analyzed according to HDV and hepatitis B virus (HBV) serological status. HDV-PCR was positive in 5 patients. Two had detectable serum HDV antigen. Four patients had anti-HD IgM and IgG antibodies. All these patients were HBs antigen-positive, and 3 were HBV-DNA-positive. All the other patients were HDV-PCR-negative. Statistical analysis suggested more extensive liver damage and immunological impairment in HDV-PCR-positive patients. In this unselected HIV-infected population, HDV-RNA detection by PCR was restricted to HDV infected patients in whom 5/19 were positive. This test permitted direct diagnosis of HDV viremia and will be useful for monitoring HDV infection.

Polymerase chain reaction-based detection of hepatitis D virus RNA in patients infected with human immunodeficiency virus.

We used the polymerase chain reaction (PCR) to detect hepatitis D (HD) viremia in patients infected with the human immunodeficiency virus (HIV). Nineteen (9%) of 206 such patients were prospectively found to be infected by HDV. Thirty-one anti-HIV-positive patients were studied by means of PCR and the results were analysed according to HDV and hepatitis B virus (HBV) serological status. HDV-PCR was positive in five patients. Two had detectable serum HDV antigen. Four patients had anti-HD IgM and IgG antibodies. All these patients were HBs antigen-positive, and three were HBV-DNA positive. All the other patients were HDV-PCR-negative. Statistical analysis suggested more extensive liver damage and immunological impairement in HDV-PCR positive patients. In this unselected HIV-infected population, HDV-RNA detection by PCR was only evidenced in HDV infected patients in whom 5/19 were positive. This test allowed direct diagnosis of HDV viremia and will be useful for the monitoring of HDV infection.