Here we report the solid phase synthesis and characterization (LC-ESIMS, CD) of a cationic nucleobase-containing α-peptide, composed of both l-arginine residues and l-lysine-based nucleoamino acids ...sequentially present in the structure. The binding properties of this novel basic nucleopeptide towards nucleic acids were investigated by CD spectroscopy which revealed the ability of the thymine-containing oligomer to bind both adenine-containing DNA (dA
) and RNA (poly rA) molecules inducing high conformational variations in the nucleic acid structures. Moreover, the artificial oligonucleotide inhibited the enzymatic activity of HIV reverse transcriptase, opening the door to the exploitation of novel antiviral strategies inspired to this molecular tool.
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IJS, KILJ, NUK, UL, UM, UPUK
Correction for 'Solid phase synthesis and RNA-binding activity of an arginine-containing nucleopeptide' by G. N. Roviello
et al.
,
RSC Adv.
, 2016,
6
, 14140-14148.
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In this paper methods for obtaining graphene oxide from rice husk were developed, which using a downward approach based on a four-stage strategy: preliminary carbonization, desilication, activation ...with KOH, and exfoliation and its comparison with the method of graphite oxidation. The samples were analyzed by elemental analysis, SEM, Raman, TGA and FTIR. The elemental analysis show that the proposed approach allows to produce graphene materials with a carbon content around 70% and rich in inorganic matter (0–20 wt.%) (K, Fe, Si). To remove inorganic contents, purification and functionalization step were applied. The Raman spectra of the samples indicate the presence of a mixture of graphene layers and amorphous carbon. The thermogravimetric profile of samples is characterized by a slowly weight decrease up to a final residue of ~10 wt.%. FTIR spectra are characterized by the typical broad shape of large condensed aromatic carbon bonds; only the peak due to C=C stretching modes and the overlapped peaks between 900 and 1500 cm-1 due to skeleton vibrations are detected.
Nucleobase-bearing peptides and their interaction with DNA and RNA are an important topic in the development of therapeutic approaches. On one hand, they are highly effective for modulating the ...nucleic-acid-based biological processes. On the other hand, they permit to overcome some of the main factors limiting the therapeutic efficacy of natural oligonucleotides, such as their rapid degradation by nucleases.
This article describes the synthesis and characterization of a novel thymine-bearing nucleoamino acid based on the l-diaminopropionic acid (l-Dap) and its solid phase oligomerization to α-peptides (oligoDapT), characterized using mass spectrometry, spectroscopic techniques, and scanning electron microscopy (SEM) analysis. The interaction of the obtained nucleopeptide with DNA and RNA model systems as both single strands (dA
, rA
, and poly(rA)) and duplex structures (dA
/dT
and poly(rA)/poly(rU)) was investigated by means of circular dichroism (CD) and ultraviolet (UV) experiments. From the analysis of our data, a clear ability of the nucleopeptide to bind nucleic acids emerged, with oligoDapT being able to form stable complexes with both unpaired and double-stranded DNA and RNA. In particular, dramatic changes in the dA
/dT
and poly(rA)/poly(rU) structures were observed as a consequence of the nucleopeptide binding. CD titrations revealed that multiple peptide units bound all the examined nucleic acid targets, with T
/A or T
/A:T(U) ratios >4 in case of oligoDapT/DNA and ~2 in oligoDapT/RNA complexes.
Our findings seem to indicate that Dap-based nucleopeptides are interesting nucleic acid binding-tools to be further explored with the aim to efficiently modulate DNA- and RNA-based biological processes.
In the present study, we report the interaction of an artificial oligolysine (referred to as AOL) realized in our laboratory with targets of biomedical importance. These included polyinosinic acid ...(poly rI) and its complex with polycytidylic acid (poly I:C), RNAs with well-known interferon-inducing ability, and double-stranded (ds) DNA. The ability of the peptide to bind both single-stranded poly rI and ds poly I:C RNAs emerged from our circular dichroism (CD) and ultraviolet (UV) studies. In addition, we found that AOL forms complexes with dsDNA, as shown by spectroscopic binding assays and UV thermal denaturation experiments. These findings are encouraging for the possible use of AOL in biomedicine for nucleic acid targeting and oligonucleotide condensation, with the latter being a key step preceding their clinical application. Moreover, we tested the ability of AOL to bind to proteins, using serum albumin as a model protein. We demonstrated the oligolysine-protein binding by CD experiments which suggested that AOL, positively charged under physiological conditions, binds to the protein regions rich in anionic residues. Finally, the morphology characterization of the solid oligolysine, performed by scanning electron microscopy, showed different crystal forms including cubic-shaped crystals confirming the high purity of AOL.
•Natural and anthropogenic radionuclides along the Domitia sandy beaches.•The natural (238U, 232Th, 226Ra, 40K) activities increase in the sand fraction.•The Cesium (137Cs) activity excludes any ...contribution of the nuclear plant.•The Plutonium ratios (240Pu/239Pu) exclude any contribution of the nuclear plant.•The applied methodology can be used as a reference for sand analyses.
The work aims to investigate the distribution versus depth of natural (238U, 232Th, 226Ra, 40K) and anthropogenic radionuclides (137Cs, 239Pu, 240Pu) along the Domitia coastal zone (Campania Region, Southern Italy) downstream the Garigliano and Volturno rivers, to value the influence of the decommissioned Garigliano Nuclear Power Plant (GNPP) releases. Despite the coastal systems are in continuous evolution, they hold memory of the radioactive contamination to be monitored in order to disseminate new knowledge both about the geochemistry of the isotopes and on their possible interactions with the geologic-sedimentologic context. Given the limited scientific investigations during the years in this field, the present work attempted to fill the gap of knowledge, trying to investigate the presence of radionuclide pollution in the Campanian coastal littoral. A constant distribution of natural radioisotopes in the medium-fine sand fraction is found, with an increase in the coarse fraction, showing an interesting correlation between the radioactive content with the lithology and mineralogy. About the anthropogenic cesium, the low concentrations (due to its strong solubility in the water) allowed to exclude any contribution of the GNPP. Furthermore the 239,240Pu actinides results, detected for both the ivestigated areas and for the used techniques, falls completely in the reference range values: the isotopic ratio is in the global fallout range allowing to exclude any contribution from the GNPP. The extraction and purification method has allowed to obtain excellent results to detect 239,240Pu actinides both for the ICP-MS, at Risø National Laboratory, and for the AMS technique, at CIRCE laboratory. For these reason the method is so reliable and reproducible that it could be considered as a reference for future environmental radioactivity studies on the sandy matrix.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Here we report the solid phase synthesis and characterization (LC-ESIMS, CD) of a cationic nucleobase-containing α-peptide, composed of both
l
-arginine residues and
l
-lysine-based nucleoamino acids ...sequentially present in the structure. The binding properties of this novel basic nucleopeptide towards nucleic acids were investigated by CD spectroscopy which revealed the ability of the thymine-containing oligomer to bind both adenine-containing DNA (dA
12
) and RNA (poly rA) molecules inducing high conformational variations in the nucleic acid structures. Moreover, the artificial oligonucleotide inhibited the enzymatic activity of HIV reverse transcriptase, opening the door to the exploitation of novel antiviral strategies inspired to this molecular tool.
Here we report the solid phase synthesis and characterization (LC-ESIMS, CD) of a cationic nucleobase-containing α-peptide, composed of both
l
-arginine residues and
l
-lysine-based nucleoamino acids sequentially present in the structure.
Full text
Available for:
IJS, KILJ, NUK, UL, UM, UPUK
Here we report the solid phase synthesis and characterization (LC-ESIMS, CD) of a cationic nucleobase-containing α-peptide, composed of both
l
-arginine residues and
l
-lysine-based nucleoamino acids ...sequentially present in the structure.
Here we report the solid phase synthesis and characterization (LC-ESIMS, CD) of a cationic nucleobase-containing α-peptide, composed of both
l
-arginine residues and
l
-lysine-based nucleoamino acids sequentially present in the structure. The binding properties of this novel basic nucleopeptide towards nucleic acids were investigated by CD spectroscopy which revealed the ability of the thymine-containing oligomer to bind both adenine-containing DNA (dA
12
) and RNA (poly rA) molecules inducing high conformational variations in the nucleic acid structures. Moreover, the artificial oligonucleotide inhibited the enzymatic activity of HIV reverse transcriptase, opening the door to the exploitation of novel antiviral strategies inspired to this molecular tool.
Full text
Available for:
IJS, KILJ, NUK, UL, UM, UPUK
Background
Several associations between microsatellite instability (MSI) and other clinicopathological factors have been reported in gastric cancer, but the results have been ambiguous. This ...systematic review and meta‐analysis investigated the relationship between MSI and overall survival and clinicopathological characteristics of patients with gastric cancer.
Methods
A systematic literature search of the PubMed, Cochrane and Ovid databases until 31 January 2016 was performed in accordance with the PRISMA statement. The articles were screened independently according to PICO (population, intervention, comparator, outcome) eligibility criteria. All eligible articles were evaluated independently by two reviewers for risk of bias according to the Quality In Prognosis Study tool.
Results
Overall, 48 studies with a total of 18 612 patients were included. MSI was found in 9·2 per cent of patients (1718 of 18 612), and was associated with female sex (odds ratio (OR) 1·57, 95 per cent c.i. 1·31 to 1·89; P < 0·001), older age (OR 1·58, 2·20 to 1·13; P < 0·001), intestinal Laurén histological type (OR 2·23, 1·94 to 2·57; P < 0·001), mid/lower gastric location (OR 0·38, 0·32 to 0·44; P < 0·001), lack of lymph node metastases (OR 0·70, 0·57 to 0·86, P < 0·001) and TNM stage I–II (OR 1·77, 1·47 to 2·13; P < 0·001). The pooled hazard ratio for overall survival of patients with MSI versus those with non‐MSI gastric cancer from 21 studies was 0·69 (95 per cent c.i. 0·56 to 0·86; P < 0·001).
Conclusion
MSI in gastric cancer was associated with good overall survival, reflected in several favourable clinicopathological tumour characteristics.
Microsatellite instabililty subgroup does better
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
This research has investigated the properties of thermally insulating geopolymer composites that were prepared using waste expanded polystyrene as lightweight aggregate. The geopolymer matrix was ...synthetized using metakaolin and an alkaline activating solution. To improve its mechanical properties, this matrix was modified by the addition of an epoxy resin to form an organic-inorganic composite. Moreover, in order to reduce drying shrinkage marble powder was used as an inert filler. The materials obtained were characterized in terms of physico-mechanical properties, thermal performance and microstructure. The geopolymer expanded polystyrene composite have improved properties compared to Portland cement-based materials, with higher strengths and lower thermal conductivity. The research demonstrates the manufacture of sustainable lightweight thermally insulating geopolymer composites using waste expanded polystyrene.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
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