Background: Omicron JN.1 has become the dominant SARS-CoV-2 variant in recent months. JN.1 has the highest number of amino acid mutations in its receptor binding domain (RBD) and has acquired a hallmark L455S mutation...Background: Omicron JN.1 has become the dominant SARS-CoV-2 variant in recent months. JN.1 has the highest number of amino acid mutations in its receptor binding domain (RBD) and has acquired a hallmark L455S mutation. The immune evasion capability of JN.1 is a subject of scientific investigation. The US CDC used SGTF of TaqPath COVID-19 Combo Kit RT-qPCR as proxy indicator of JN.1 infections for evaluation of the effectiveness of updated monovalent XBB.1.5 COVID-19 vaccines against JN.1 and recommended that all persons aged ≥ 6 months should receive an updated COVID-19 vaccine dose. Objective: Recommend Sanger sequencing instead of proxy indicator to diagnose JN.1 infections to generate the data based on which guidelines are made to direct vaccination policies. Methods: The RNA in nasopharyngeal swab specimens from patients with clinical respiratory infection was subjected to nested RT-PCR, targeting a 398-base segment of the N-gene and a 445-base segment of the RBD of SARS-CoV-2 for amplification. The nested PCR amplicons were sequenced. The DNA sequences were analyzed for amino acid mutations. Results: The N-gene sequence showed R203K, G204R and Q229K, the 3 mutations associated with Omicron BA.2.86 (+JN.1). The RBD sequence showed 24 of the 26 known amino acid mutations, including the hallmark L455S mutation for JN.1 and the V483del for BA.2.86 lineage. Conclusions: Sanger sequencing of a 445-base segment of the SARS-CoV-2 RBD is useful for accurate determination of emerging variants. The CDC may consider using Sanger sequencing of the RBD to diagnose JN.1 infections for statistical analysis in making vaccination policies.展开更多
In order to evaluate the tendency of mechanical properties degrudation due to weld-ing and other processing in materials used for supporting coils in super conducting rnaguets utilized in thermonuclear jusion reactore...In order to evaluate the tendency of mechanical properties degrudation due to weld-ing and other processing in materials used for supporting coils in super conducting rnaguets utilized in thermonuclear jusion reactore, a small punch (SP) test was used.This test, which was originally developed to study irradiation damage using miniatursized specimens was performed at 77 and 4 K for solution treated and sensitized JN1 austenitic stainless steel, a candidate cryogenic structural material. The area under the load-deflection curve up to the maximum applied load in SP test was defined as the SP enerpy, to characterize the resistance to fracture. Although solution treated material exhibited ductile fracture mode with high SP enerpy, embrittlement behavior due to sensitization at 650-800°for 1-5 h was shown clearlg by SP test with brittle intergranular fracture and decreased SP enerpy. Comparison of the results obtained by SP test with those by fracture toughness test showed the usefulness of SP test for evaluation of sensitization induced embrittlement at cryogenic temperature. The re-sults obtained in this study can be very usefol in predicting the degradation due to welding and other processing in cryogenic materials.展开更多
Periodically updating coronavirus disease 19(COVID-19)vaccines that offer broad-spectrum protection is needed giventhe strong immune evasion by the circulating omicron sublineages.The effectiveness of prototype and BA...Periodically updating coronavirus disease 19(COVID-19)vaccines that offer broad-spectrum protection is needed giventhe strong immune evasion by the circulating omicron sublineages.The effectiveness of prototype and BA.4/5-containing bivalent mRNA vaccines is reduced when XBB subvariants predominate.We initiated an observer-blinded,threearms study in 376 patients in Chinese individuals aged from 18 to 55 years old who had previously received three dosesCOVID-19 vaccine.Immunogenicity in terms of neutralizing antibodies elicited by a 30-mg dose of XBB.1.5-containingbivalent vaccine(RQ3027),a 30-mg dose of BA.2/BA.5-Alpha/Beta bivalent vaccine(RQ3025)and their precedent 30-mg Alpha/Beta(combined mutations)monovalent mRNA vaccine(RQ3013)and safety are primary and secondary endpoints,respectively.We recorded prescribed COVID-19 cases to explore the preliminary efficacy of three vaccines.RQ3027 and RQ3025 boosters elicited superior neutralizing antibodies(NAbs)against XBB.1.5,XBB.1.16,XBB.1.9.1,and JN.1 compared to RQ3013 at day 14 in participants without SARS-CoV-2 infection.All study vaccines were welltolerated without serious adverse reactions identified.The incidence rates per 1000 person-years of COVID-19 casesduring the 2nd-19th week after randomization were lowest in RQ3027.Overall,our data show that XBB.1.5-containingbivalent booster generated superior immunogenicity and better protection against newer severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)variants compared to BA.2/BA.5-containing bivalent and Alpha/Beta monovalentwith no new safety concerns.展开更多
文摘Background: Omicron JN.1 has become the dominant SARS-CoV-2 variant in recent months. JN.1 has the highest number of amino acid mutations in its receptor binding domain (RBD) and has acquired a hallmark L455S mutation. The immune evasion capability of JN.1 is a subject of scientific investigation. The US CDC used SGTF of TaqPath COVID-19 Combo Kit RT-qPCR as proxy indicator of JN.1 infections for evaluation of the effectiveness of updated monovalent XBB.1.5 COVID-19 vaccines against JN.1 and recommended that all persons aged ≥ 6 months should receive an updated COVID-19 vaccine dose. Objective: Recommend Sanger sequencing instead of proxy indicator to diagnose JN.1 infections to generate the data based on which guidelines are made to direct vaccination policies. Methods: The RNA in nasopharyngeal swab specimens from patients with clinical respiratory infection was subjected to nested RT-PCR, targeting a 398-base segment of the N-gene and a 445-base segment of the RBD of SARS-CoV-2 for amplification. The nested PCR amplicons were sequenced. The DNA sequences were analyzed for amino acid mutations. Results: The N-gene sequence showed R203K, G204R and Q229K, the 3 mutations associated with Omicron BA.2.86 (+JN.1). The RBD sequence showed 24 of the 26 known amino acid mutations, including the hallmark L455S mutation for JN.1 and the V483del for BA.2.86 lineage. Conclusions: Sanger sequencing of a 445-base segment of the SARS-CoV-2 RBD is useful for accurate determination of emerging variants. The CDC may consider using Sanger sequencing of the RBD to diagnose JN.1 infections for statistical analysis in making vaccination policies.
文摘In order to evaluate the tendency of mechanical properties degrudation due to weld-ing and other processing in materials used for supporting coils in super conducting rnaguets utilized in thermonuclear jusion reactore, a small punch (SP) test was used.This test, which was originally developed to study irradiation damage using miniatursized specimens was performed at 77 and 4 K for solution treated and sensitized JN1 austenitic stainless steel, a candidate cryogenic structural material. The area under the load-deflection curve up to the maximum applied load in SP test was defined as the SP enerpy, to characterize the resistance to fracture. Although solution treated material exhibited ductile fracture mode with high SP enerpy, embrittlement behavior due to sensitization at 650-800°for 1-5 h was shown clearlg by SP test with brittle intergranular fracture and decreased SP enerpy. Comparison of the results obtained by SP test with those by fracture toughness test showed the usefulness of SP test for evaluation of sensitization induced embrittlement at cryogenic temperature. The re-sults obtained in this study can be very usefol in predicting the degradation due to welding and other processing in cryogenic materials.
基金supported by a grant(2023YFC2307600,to Z.J.Z.)from the Na-tional Key Research and Development Program of Chinaa grant(202102AA100051,to Z.J.Z.)from the Yunnan Provincial Sci-ence and Technology Department,China+2 种基金a grant(H-2018102,to J.W.)from the High-level Health Technical Personnel Project of Yunnan Province,Chinaa grant(2022SCP001,to Z.J.Z.)from the Spring City Plan:The High-level Talent Promotion and Training Project of Kunmingand a grant(32371000,to C.M.L.)from the National Natural Science Foundation of China.
文摘Periodically updating coronavirus disease 19(COVID-19)vaccines that offer broad-spectrum protection is needed giventhe strong immune evasion by the circulating omicron sublineages.The effectiveness of prototype and BA.4/5-containing bivalent mRNA vaccines is reduced when XBB subvariants predominate.We initiated an observer-blinded,threearms study in 376 patients in Chinese individuals aged from 18 to 55 years old who had previously received three dosesCOVID-19 vaccine.Immunogenicity in terms of neutralizing antibodies elicited by a 30-mg dose of XBB.1.5-containingbivalent vaccine(RQ3027),a 30-mg dose of BA.2/BA.5-Alpha/Beta bivalent vaccine(RQ3025)and their precedent 30-mg Alpha/Beta(combined mutations)monovalent mRNA vaccine(RQ3013)and safety are primary and secondary endpoints,respectively.We recorded prescribed COVID-19 cases to explore the preliminary efficacy of three vaccines.RQ3027 and RQ3025 boosters elicited superior neutralizing antibodies(NAbs)against XBB.1.5,XBB.1.16,XBB.1.9.1,and JN.1 compared to RQ3013 at day 14 in participants without SARS-CoV-2 infection.All study vaccines were welltolerated without serious adverse reactions identified.The incidence rates per 1000 person-years of COVID-19 casesduring the 2nd-19th week after randomization were lowest in RQ3027.Overall,our data show that XBB.1.5-containingbivalent booster generated superior immunogenicity and better protection against newer severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)variants compared to BA.2/BA.5-containing bivalent and Alpha/Beta monovalentwith no new safety concerns.
