An ancient coronavirus from individuals in France, circa 16th century.

OBJECTIVES: At the time when the COVID-19 pandemic was responsible for more than six million deaths worldwide, the antiquity of coronaviruses remains undefined. We investigated individuals buried during the 16th century in France for the direct and paleoserological diagnosis of the coronavirus. METHODS: The 2011-2012 excavation of Abbey Saint-Pierre in Baume-Les-Messieurs, France uncovered 12 skeletons of individuals from the 13th to the 18th century. The total proteins extracted from dental pulps were subjected to microbial paleoserology, targeting SARS-CoV-2, human-associated coronavirus (HCoV)-229E, and OC43 antigens and for coronavirus peptide research using metaproteomics, in parallel to negative controls. RESULTS: Three peptide sequences totaling 36 amino acids indicative of a coronavirus were retrieved from the dental pulp remains collected from two individuals buried circa 16th century, in whom paleoserology confirmed a specific immunological response against modern-day SARS-CoV-2 and HCoV-229E. CONCLUSION: We provide serological and proteomic evidence for a betacoronavirus with no modern correspondent, infecting populations in the 16th century, extending the antiquity of coronaviruses by more than three centuries. Historical, archaeozoological, and paleoproteomic data suggested close contacts between these two individuals and domestic swine, cattle, and poultry, suggesting an ancient zoonotic coronavirus. Coronaviruses have been undesirable companions of populations long before the ongoing coronavirus disease 2019 outbreak emerged.

Five millennia of Bartonella quintana bacteraemia.

During the two World Wars, Bartonella quintana was responsible for trench fever and is now recognised as an agent of re-emerging infection. Many reports have indicated widespread B. quintana exposure since the 1990s. In order to evaluate its prevalence in ancient populations, we used real-time PCR to detect B. quintana DNA in 400 teeth collected from 145 individuals dating from the 1st to 19th centuries in nine archaeological sites, with the presence of negative controls. Fisher's exact test was used to compare the prevalence of B. quintana in civil and military populations. B. quintana DNA was confirmed in a total of 28/145 (19.3%) individuals, comprising 78 citizens and 67 soldiers, 20.1% and 17.9% of which were positive for B. quintana bacteraemia, respectively. This study analysed previous studies on these ancient samples and showed that the presence of B. quintana infection followed the course of time in human history; a total of 14/15 sites from five European countries had a positive prevalence. The positive rate in soldiers was higher than those of civilians, with 20% and 18.8%, respectively, in the 18th and 19th centuries, but the difference in frequency was not significant. These results confirmed the role of dental pulp in diagnosing B. quintana bacteraemia in ancient populations and showed the incidence of B. quintana in both civilians and soldiers.

An outbreak of relapsing fever unmasked by microbial paleoserology, 16th century, France.

OBJECTIVES: Depicting past epidemics currently relies on DNA-based detection of pathogens, an approach limited to pathogens with well-preserved DNA sequences. We used paleoserology as a complementary approach detecting specific antibodies under a mini line-blot format including positive and negative control antigens. METHODS: Mini line blot assay incorporated skim milk as negative control, Staphylococcus aureus as positive control, and antigens prepared from lice-borne pathogens Rickettsia prowazekii, Borrelia recurrentis, Bartonella quintana, and Yersinia pestis. Paleoserums were extracted from rehydrated dental pulp recovered from buried individuals. Mini line blots observed with the naked eye, were quantified using a scanner and appropriate software. Paleoserology was applied to the indirect detection of lice-borne pathogens in seven skeletons exhumed from a 16th-17th century suspected military burial site (Auxi-le-Château); and 14 civils exhumed from a 5th-13th century burial site (Saint-Mont). Direct detection of pathogens was performed using quantitative real-time PCR. RESULTS: In Auxi-le-Château, paleoserology yielded 7/7 interpretable paleoserums including 7/7 positives for B. recurrentis including one also positive for B. quintana. In Saint-Mont, paleoserology yielded 8/14 interpretable paleoserums and none reacted against any of the four pathogens. Antibodies against R. prowazekii and Y. pestis were not detected. The seroprevalence was significantly higher in the military burial site of Auxi-le-Château than in the civil burial site of Saint-Mont. Real-time PCR detection of B. quintana yielded 5/21 positive (3 at Saint-Mont and 2 at Auxi-le-Château) whereas B. recurrentis was not detected. CONCLUSIONS: Paleoserology unmasked an outbreak of relapsing B. recurrentis fever in one 16th - 17th century military garrison, missed by real-time PCR. Paleoserology offers a new tool for investigating past epidemics, in complement to DNA sequence-based approaches.

Bimetallic Catalytic Systems Based on Sb, Ge and Ti for the Synthesis of Poly(ethylene terephthalate-co-isosorbide terephthalate).

The insertion of rigid monomers such as isosorbide into poly(ethylene terephthalate) (PET) allows for the access of polymers with improved properties, notably in terms of thermal stability. This biobased monomer is however poorly reactive, and harsh reaction conditions lead to color concerns regarding the resulting polymer. This has motivated the development of catalytic systems enabling an increase of the reaction rate and a good coloration. In this study, we have assessed bimetallic catalytic systems based on the main metals used for PET catalysis, i.e., antimony, germanium and titanium, for the synthesis of poly(ethylene terephthalate-co-isosorbide terephthalate) (PEIT). The Sb2O3/Ti(OiPr)4 combination leads to a high reaction rate while maintaining an acceptable coloration. On the other hand, combining Sb2O3 with GeO2 affords the formation of poly(ethylene terephthalate-co-isosorbide terephthalate) without coloration concerns and a reaction rate higher than that observed using the single metal catalysts. Molecular weights and microstructure including diethyleneglycol (DEG) and isosorbide contents are also discussed, together with the thermal properties of the resulting PEIT. The GeO2/Ti(OiPr)4 is also assessed, and leads to average performances.

Synthesis of 1,4:3,6-dianhydrohexitols diesters from the palladium-catalyzed hydroesterification reaction.

The hydroesterification of alpha olefins has been used to synthesize diesters from bio-based secondary diols: isosorbide, isomannide, and isoidide. The reaction was promoted by 0.2% palladium catalyst generated in situ from palladium acetate/triphenylphosphine/para-toluene sulfonic acid. Optimized reaction conditions allowed the selective synthesis of the diesters with high yields and the reaction conditions could be scaled up to the synthesis of hundred grams of diesters from isosorbide and 1-octene with solvent-free conditions.

A joint experimental/theoretical investigation of the statistical olefin/conjugated diene copolymerization catalyzed by a hemi-lanthanidocene [(Cp*)(BH4)LnR].

Statistical copolymerization of ethylene and isoprene was achieved by using a borohydrido half-lanthanidocene complex. Under copolymerization conditions, activation of [(Cp*)(BH(4))(2)Nd(thf)(2)] (Cp*=η(5)-C(5)Me(5)) by an appropriate alkylating agent affords trans-1,4-poly-isoprene-co-ethylene. Analysis of the microstructure of the copolymer revealed the presence of successive short sequences of ethylene/ethylene, trans-1,4-isoprene/ethylene, and trans-1,4-isoprene/trans-1,4-isoprene. A small amount of 1,2-insertion of isoprene was observed, and no cyclic structures within the chain were characterized. Test runs showed that these catalysts are unable to copolymerize α-olefins (such as hex-1-ene) with isoprene. The probable initial steps in the copolymerization have been computed at the DFT level of theory. Analysis of the energy profile provides insight into the catalyst's activity and selectivity. Our theoretical results highlight the key role played by the allyl intermediate, in which diene insertion, and to a lesser extent olefin insertion, is the rate-determining step of the process. These results also illustrate the coordination behavior of the allyl ligand during the insertion of an incoming monomer, which directly inserts, after pre-coordination to the metal center, into the η(3)-allyl ligand without inducing an η(3) to η(1) haptotropic shift. Finally, the inactivity of this family of catalysts towards the copolymerization of hex-1-ene was rationalized on the basis of the free-energy profile of the copolymerization.

Neodymium alkoxides: synthesis, characterization and their combinations with dialkylmagnesiums as unique systems for polymerization and block copolymerization of ethylene and methyl methacrylate.

The synthesis and characterization (NMR and X-ray) of a variety of neodymium alkoxides derived from simple and functionalized tertiary monoalcohols, and their application as inorganic precursors in combination with dialkylmagnesium reagents for ethylene and methyl methacrylate (MMA) (co)polymerization have been investigated. Salt metathesis reactions between NdCl(3) and sodium alkoxides in THF led to the formation of trinuclear complexes [Nd(3)(mu(3)-OR)(2)(mu(2)-OR)(3)(OR)(4)(thf)(2)] with R=tBu (1), tAm (2), while aggregate structure [Nd(12)(OtAm)(26)(HOtAm)(2)Cl(11)Na].(OEt(2))(2) (3) was obtained when the synthesis was performed in Et(2)O. [Nd(3)(mu(3)-OtBu)(2)(mu(2)-OtBu)(3)(OtBu)(4)(HOtBu)(2)] (4), prepared by aminolysis of Nd[N(SiMe(3))(2)](3) in hexane, slowly decomposed in toluene into oxo complex [Nd(5)(mu(5)-O)(mu(3)-OtBu)(4)(mu(2)-OtBu)(4)(OtBu)(5)] (5). Finally, the dimer [Nd(2)(mu(2),eta(2)-OR)(2)(eta(2)-OR)(2)(eta(1)-OR)(2)] (OR=OCMe(2)CH(2)CH(2)OMe) (6) was synthesised by aminolysis reaction from the corresponding gamma-donor-functionalized alcohol. Some of these neodymium alkoxides, in particular homoleptic complex 1, when associated in situ to one equivalent of a dialkylmagnesium, allow the formation of an active catalyst for ethylene polymerization. Under mild conditions (0 degrees C, 1 bar), the latter catalyst system exhibited a moderate activity (5-10 kg mol(-1) h(-1) bar(-1)). Effective transfer reactions were observed in the presence of H(2) or PhSiH(3) and renewal/improvement of activity occurred upon extra addition of dialkylmagnesium. The most outstanding feature of this catalytic system lies in the precipitation of the active "Nd-polyethylenyl" species during the ethylene polymerization course as solid S which could be isolated. This heterogeneity was turned to good account, enabling to achieve heterogeneous solid-gas ethylene polymerization and to prepare diblock PE-PMMA copolymers with high diblock efficiency and high molecular weights (M(n) > 200 000). A catalytic cycle for this unique system is proposed based on the isolation of a transmetallation product (7) from a neodymium alkoxide/dialkylmagnesium combination and NMR studies of the latter.