Objective:To evaluate the cost-effectiveness of annual trivalent inactivated influenza vaccine(IIV3)under the context of Zhejiang province.Methods:A state transition simulation model was constructed to estimate the he...Objective:To evaluate the cost-effectiveness of annual trivalent inactivated influenza vaccine(IIV3)under the context of Zhejiang province.Methods:A state transition simulation model was constructed to estimate the health and economic outcomes of IIV3 vaccination program compared to no vaccination for hypothetical cohorts of Zhejiang province stratified by age and risk status.Model input parameters were chosen based on published literatures and expert advices.The analysis used societal perspectives and a one-year time horizon,and permanent outcomes were also included.The primary outcome was the incremental cost-effectiveness ratio(ICER),with expression of US dollars per quality adjusted life years(QALYs)gained.Results:In subgroups not at high risk for influenza-related complications(non-high risk subgroup),ICER ranged from $6268/QALY(for adults aged 50-64 years)to $11260/QALY(for children aged from 6 months to 4 years).In subgroups at high risk for influenza-related complications(high risk subgroup),ICER ranged from cost-saving(adults aged≥65 years)to $5260/QALY(for children aged from 6 months to 4 years).ICER were most sensitive to changes in probability of influenza illness,cost of hospitalization,and probability of death for adults aged 18-49 years with non-high risk status.Conclusions:ICERs of annual influenza vaccination varied by age and risk status but were less than the Gross Domestic Product(GDP)per capita of Zhejiang province($17745 in 2023),which remained cost-effective for all-age and different risk status groups from a societal perspective.展开更多
Some H5 viruses isolated in poultry or wild birds between 2020 and 2021 were found to be antigenically different from the vaccine strains(H5-Re11 and H5-Re12) used in China. In this study, we generated three new recom...Some H5 viruses isolated in poultry or wild birds between 2020 and 2021 were found to be antigenically different from the vaccine strains(H5-Re11 and H5-Re12) used in China. In this study, we generated three new recombinant vaccine seed viruses by using reverse genetics and used them for vaccine production. The vaccine strain H5-Re13 contains the hemagglutinin(HA) and neuraminidase(NA) genes of an H5 N6 virus that bears the clade 2.3.4.4 h HA gene, H5-Re14 contains the HA and NA genes of an H5 N8 virus that bears the clade 2.3.4.4 b HA gene, and H7-Re4 contains the HA and NA genes of H7 N9 virus detected in 2021. We evaluated the protective efficacy of the novel H5/H7 trivalent inactivated vaccine in chickens, ducks, and geese. The inactivated vaccine was immunogenic and induced substantial antibody responses in the birds tested. Three weeks after vaccination, chickens were challenged with five different viruses detected in 2020 and 2021: three viruses(an H5 N1 virus, an H5 N6 virus, and an H5 N8 virus) bearing the clade 2.3.4.4 b HA gene, an H5 N6 virus bearing the clade 2.3.4.4 h HA gene, and an H7 N9 virus. All of the control birds shed high titers of virus and died within 4 days post-challenge, whereas the vaccinated chickens were completely protected from these viruses. Similar protective efficacy against H5 viruses bearing the clade 2.3.4.4 h or 2.3.4.4 b HA gene was observed in ducks and geese. Our study indicates that the newly updated H5/H7 vaccine can provide solid protection against the H5 and H7 N9 viruses that are currently circulating in nature.展开更多
We developed an H5/H7 trivalent inactivated vaccine by using Re-11, Re-12, and H7-Re2 vaccine seed viruses, which were generated by reverse genetics and derived their HA genes from A/duck/Guizhou/S4184/2017(H5N6) (DK/...We developed an H5/H7 trivalent inactivated vaccine by using Re-11, Re-12, and H7-Re2 vaccine seed viruses, which were generated by reverse genetics and derived their HA genes from A/duck/Guizhou/S4184/2017(H5N6) (DK/GZ/S4184/17) (a clade 2.3.4.4d virus), A/chicken/Liaoning/SD007/2017(H5N1) (CK/LN/SD007/17) (a clade 2.3.2.1d virus), and A/chicken/ Guangxi/SD098/2017(H7N9) (CK/GX/SD098/17), respectively. The protective efficacy of this novel vaccine and that of the recently used H5/H7 bivalent inactivated vaccine against different H5 and H7N9 viruses was evaluated in chickens. We found that the H5/H7 bivalent vaccine provided solid protection against the H7N9 virus CK/GX/SD098/17, but only 50–60% protection against different H5 viruses. In contrast, the novel H5/H7 trivalent vaccine provided complete protection against the H5 and H7 viruses tested. Our study underscores the importance of timely updating of vaccines for avian influenza control.展开更多
The aim of this study is to evaluate the effect of various molar ratios of glycine to chromium salt(Gly:Cr)and different current densities on the corrosion and wear behaviors of Cr(III)electroplated coatings.The morph...The aim of this study is to evaluate the effect of various molar ratios of glycine to chromium salt(Gly:Cr)and different current densities on the corrosion and wear behaviors of Cr(III)electroplated coatings.The morphology and thickness of the coatings were investigated by scanning electron microscopy.The wear properties of the coatings were studied using pin on disk and hardness tests,while corrosion behavior of the coatings was identified using linear polarization,small amplitude cyclic voltammetry,and electrochemical impedance spectroscopy methods.By increasing the glycine concentration,a structure with low crack density was obtained.In all molar ratios,maximum thickness and current efficiency was observed at a current density of 150 mA·cm?2.All the electrochemical methods had a consistent result,and maximum corrosion resistance of approximately 16000Ω·cm2 was obtained in the case of Gly:Cr=3:1 and current density of 200 mA·cm?2.展开更多
The formulation of hard chromium plating from trivalent chromium electrolyte and its related process have been intensively studied in this work. Through optimized conditions, the coating hardness can achieve more than...The formulation of hard chromium plating from trivalent chromium electrolyte and its related process have been intensively studied in this work. Through optimized conditions, the coating hardness can achieve more than HV0.1900 without any treatment and HV0.11700 after heat treatment for five minutes at 300°C, and the thickness of hard chromium coating was about 100 μm. The hard chromium coatings show good adhesion on the carbon steel and low alloy structural steel. The corrosion resistance of hard chromium coatings was enhanced by the adding nanometer materials into trivalent chromium plating coatings. More than 120 hours salt spray corrosion resistance can be achieved with 40 to 50 microns thickness of trivalent chromium plating coatings.展开更多
The lanthanum trivalent ion doped TiO2 nanopowders were prepared by liquid plasma spray with solution of titanium tetra-tert-butoxide and alcohol as feedstock and La(NO3)3·6H2O as doping component. The photocatal...The lanthanum trivalent ion doped TiO2 nanopowders were prepared by liquid plasma spray with solution of titanium tetra-tert-butoxide and alcohol as feedstock and La(NO3)3·6H2O as doping component. The photocatalytic activity of samples at different doping concentrations in photocatalytic degradation of methyl orange was discussed. The powders were characterized by Transmission Electron Microscopy (TEM) and X-Ray Diffraction (XRD), and the effect of doped ion on the pattern, phase composition and crystallite sizes were analyzed. The results indicated that lanthanum trivalent ion doped TiO2 nanopowders could be prepared by liquid plasma spray. Lanthanum trivalent ion doping increased the photocatalytic activity of TiO2 greatly, the optimal doping concentration was 0.5%. The doped powders were the mixture of anatase phase and rutile phase. The contents of anatase phase decreased firstly and then increased with an increase in the contents of lanthanum trivalent ion. Doping lanthanum trivalent ion could make the TiO2 nanopowders uniform and reduced its particle size.展开更多
Considering aviation and space sectors, aluminium alloys are commonly used due to its excellent mechanical and physical properties. Though satellite hard-ware is confined to controlled environment, it requires anticor...Considering aviation and space sectors, aluminium alloys are commonly used due to its excellent mechanical and physical properties. Though satellite hard-ware is confined to controlled environment, it requires anticorrosive treatment over metal substrate followed by a systematic coating scheme. The trivalent chromium coating was deposited over three aluminium alloys namely AA6063, AA7075 and AA6082. The variation in corrosion resistance property of trivalent chromium over each aluminium alloy has been studied in detail. The Neutral Salt Spray (NSS) test result shows that trivalent chromium coating over AA7075 alloy is affected by pitting corrosion compared to other two alloys. In addition to that, NSS test also proves that thickness of the layer does not have any influence corrosion resistance property of trivalent chromium coating. Furthermore, ions in trivalent chromium coating was identified using Secondary Neutral Mass Spectroscopy (SNMS) and degradation of coating in a corrosive liquid studied using Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) instrument to understand mechanism of corrosion. The results indicated that both coating and substrate is involved in corrosion process. The number of elements dissolved in to salt solution reveals the weak ionic bonding of coating towards substrates. In comparison, AA7075 alloy has weaker bonding than AA6082 and AA6063 series. The alloying elements such as zinc and copper are removed from substrate by corrosive solution.展开更多
Alkaloids are natural, semisynthetic or synthetic organic compounds, normally polar with basic chemical properties and containing at least one nitrogen atom in a heterocyclic ring. Some synthetic or semisynthetic subs...Alkaloids are natural, semisynthetic or synthetic organic compounds, normally polar with basic chemical properties and containing at least one nitrogen atom in a heterocyclic ring. Some synthetic or semisynthetic substances resemble the alkaloid architecture. Trivalent nitrogen in these substances is normal;however, some natural and semisynthetic alkaloids have pentavalent nitrogen. The drug pholcodine is a derivative of morphine. Pholcodine has very little addiction- developing effect. It is a semisynthetic alkaloid that was first synthesized in 1950 by Chabrier et al. Pholcodine possesses antitussive (cough relief) properties similar to codeine, morphine and ethylmorphine. The drug was used in liquid formulations as Tuxi and Tuxi Forte, and it is in present use in Tuxidrin as liquid mixture and in tablet form. Pholcodine is an Active Pharmacological Ingredient (API) in tablets and liquid mixtures. Leiras International and Weifa in Norway manufacture medical forms with pholcodine. Several impurities in pholcodine were described by J. Roe in 1997 and by Denk et al. in 2000 and 2002. In addition, several degradation products may be formed in liquid formulations under storage. Some of these products are related not to the original production of pholcodine but rather to its oxidation under storage. The appearance of degradation products strongly depends on the storage temperature and pH of the liquid phase. Pholcodine-N-oxide and pholcodine-N,N’-dioxide are among the degradation (oxidation) products;pholcodine can also degrade to morphine. There is little information about the toxicity of the N-oxide and no information on the N,N’-di- oxide of pholcodine. In this study, the fact that morphine is generated during the storage of formulations containing pholcodine is presented. Another antitussive mixture under the name Cosylan was analyzed to examine the oxidation of ethylmorphine to ethylmorphine-N-oxide. Ethylmorphine is the API in Cosylan.展开更多
Hydrothermal reaction of terbium（ Ⅲ） chloride with 5-sulfoisophthalic acid monosodium salt and 1,10-phenanthroline（phen） at 415 K resulted in the formation of a novel coordination polymer, [ Tb （sip） （phen） ...Hydrothermal reaction of terbium（ Ⅲ） chloride with 5-sulfoisophthalic acid monosodium salt and 1,10-phenanthroline（phen） at 415 K resulted in the formation of a novel coordination polymer, [ Tb （sip） （phen） （H2O） ],（sip =5-sulfoisophthalate trivalent anion） with a three-dimensional network structure. Each centrosymmetrically related pair of terbium ions axe linked by two sip anions, forming a binuclear unit, and each binuclear unit links to four adjacent tetranuclear units, extending a two-dimensional hybrid layer at crystallographic bc plane. On the other hand, every three-terbium ion is connected by three sip anions, generating a trinuclear ring, and the trinuclear ring connects six neighboring trinuclear rings to produce another two-dimensional layer at crystallographic ab plane. Moreover, each sip anion acts as a pontadentate bridge, interconnecting two different types of layers to yield a novel three-dimensional framework.展开更多
The title complex [(phen) 2Cu(Htcb)Cu(phen) 2]H 3tcb(tcb=1,2,4,5-benzenetetracarboxylato tetravalent anion; phen=1,10-phenanthroline) was synthesized by the hydrothermal synthesis method. The crystal structure was ...The title complex [(phen) 2Cu(Htcb)Cu(phen) 2]H 3tcb(tcb=1,2,4,5-benzenetetracarboxylato tetravalent anion; phen=1,10-phenanthroline) was synthesized by the hydrothermal synthesis method. The crystal structure was determined by single-crystal X-ray diffraction analysis. It crystallizes in the triclinic system with space group P1, a=1.04174(8) nm, b=1.07119(8) nm, c=1.26360(10) nm, α=98.169(2)°, β=99.679(10)°, γ=93.658(10)°, V=1.37031(18) nm3, Z=1. The two copper(Ⅱ) cations are bridged by Htcb in the monodentate fashion, and have the same five-coordinated environment completed by the four N atoms from the two phen molecules and one O atom from the carboxylic group of Htcb respectively, which can be best described as distorted trigonal-bipyramid geometry. Moreover, the three dimensional network is formed by H-bonding interactions [O…O distance from 0.2506(10) nm to 0.3176(11) nm] and π-π stacking interactions between the phen rings of adjacent binuclear entities with a face-to-face separation of ca. 0.354 nm.展开更多
Ulcerative colitis (UC) has reactive oxygen species (ROS) and immunologic pathways implicated in its pathogenesis. The search for new therapeutic protocols in managing UC is tailored in suppressing or preventing these...Ulcerative colitis (UC) has reactive oxygen species (ROS) and immunologic pathways implicated in its pathogenesis. The search for new therapeutic protocols in managing UC is tailored in suppressing or preventing these pathways. The influence of trivalent chromium (Cr3+), an essential mineral on experimental colitis was investigated. Mice were grouped into 3;group 1 (control) received clean drinking water while groups 2 and 3 received 10 and 100 ppm Cr3+ respectively for 12 weeks through drinking water. After Cr3+ administration, 5 animals per group were sacrificed on day 0. Thereafter, experimental colitis was induced intra-rectally using acetic acid (4%, 0.3mL) and 5 mice per group were subsequently sacrificed on days 3, 7 and 14. Blood and colonic tissues were obtained and processed appropriately. Blood Cr3+ level, haematological variables, gross and microscopic colitis scores, colonic myeloperoxidase (MPO), Superoxide Dismutase (SOD) and malondialdehyde (MDA) levels were determined using standard methods. Colon cytokine mRNA genes were quantified using real-time PCR. There was a significant decrease in colon gross and histology scores on days 3 and 7 in chromium treated compared with control. The MPO and MDA in chromium groups reduced significantly compared with control while SOD activities increased significantly in Cr3+ groups compared with control. Total RNA increased in chromium groups compared with control on day 3 post-colitis. There was up-regulation of IL-10, down-regulation of TNF-α and IFN-λ in chromium administered groups compared with control. Chromium enhanced healing of colitis by suppression of ROS, inflammation and promotion of antioxidant activities.展开更多
In the paper “Supercritical Fluid Chromatography-Mass Spectrometry (SFC-MS) and MALDI-TOF-MS of Heterocyclic Compounds with Trivalent and Pentavalent Nitrogen in Cough Relief Medical Forms Tuxi and Cosylan” [1], the...In the paper “Supercritical Fluid Chromatography-Mass Spectrometry (SFC-MS) and MALDI-TOF-MS of Heterocyclic Compounds with Trivalent and Pentavalent Nitrogen in Cough Relief Medical Forms Tuxi and Cosylan” [1], the presence of morphine and other degradation products of pholcodine in cough relief medical forms of Tuxi are discussed. Tuxiis recalled from the Norwegian market by Weifa pharmaceutical company, and hence it no longer presents problems to users and health authorities there;however, the medical form Tuxidrin, which contains a significant amount of pholcodine as the active pharmacological ingredient, is still marketed. In the present paper, Tuxidrin is analyzed to determine the presence of degradation products of pholcodine. The degradation of pholcodine to morphine has been discussed previously as a factor in the development of addiction to narcotics in young persons. The structures of the contaminants in Tuxidrin, such as oxides of pholcodine, are elucidated in the present paper. The toxicity and pharmacology of oxides of alkaloids have generally not been well studied, and very little is known about the toxicity and pharmacology of the degradation (oxidation) products of pholcodine: the N-oxide and the N, N'-dioxide of pholcodine. According to Brondz and Brondz[1], the N-oxide and possibly also the N, N'-dioxide are less toxic than the original alkaloids and possess greater pharmacological activity, and hence they may be a source of useful new semisynthetic drugs. The question of possible addiction to pholcodine oxides has not been studied, and the potential of these substances to provoke allergies is unclear. The recall of Tuxi from the Norwegian marketis mainly based on the fact that pholcodine causes significantly increased levels of IgE antibodies in sensitized patients. Tuxidrin contains pholcodine and has the same negative effect as Tuxi, namely provoking allergies or even anaphylactic shock. From this point of view, Tuxidrin has no advantage over Tuxi. These two medical forms only differ in one respect: Tuxidrin requires a prescription (prescription duty medicine), but Tuxi doesnot (prescription free medicine). This aspect is also discussed in the present paper.展开更多
The reaction of Os(RL1)(PPh3)2(CO)Br, 1b, with qui-nolin-8-ol (HQ), 2, has furnished complexes of the type [Os(RL2)(PPh3)2(CO)(Q)], 3, in excellent yield (RL1 is C6H2O-2-CHNHC6H4R(p)-3-Me-5, RL2 is C6H2OH-2-CHNC6H4R(p...The reaction of Os(RL1)(PPh3)2(CO)Br, 1b, with qui-nolin-8-ol (HQ), 2, has furnished complexes of the type [Os(RL2)(PPh3)2(CO)(Q)], 3, in excellent yield (RL1 is C6H2O-2-CHNHC6H4R(p)-3-Me-5, RL2 is C6H2OH-2-CHNC6H4R(p)-3-Me-5 and R is Me, OMe, Cl). In this process, quinolin-8-olato (Q) undergoes five-membered chelation, the iminium-phenolato function tautomerizing to the imine-phenol function. The trans geometry of the Os(PPh3)2 fragment is consistent with the occurrence of a single 31P resonance near –6.0 ppm in 3. In dichloromethane solution, 3 displays a quasireversible 3+/3 couple near 0.40 V vs. SCE (3+ is the osmium (III) analogue of 3). Coulometrically generated solutions of 3+ displays a strong absorption near 340 nm, 415 nm and 500 nm and are one-electron paramagnetic (low-spin d5, S = 1/2) and show rhombic EPR spectra in 1:1 dichloromethanetoluene solution at 77 K with g values near 2.44, 2.20, 1.83. Distortion parameters using the observed g values have been computed. Solutions of 3 absorb near 420 nm and emit near 510 nm at 298 K and 580 nm at 77 K. The fluorescence is believed to originate from the 3MLCT state.展开更多
Foot and mouth disease is the most contagious disease of mammals and has a great potential for causing severe economic loss in susceptible cloven-hoofed animals. Routine prophylactic vaccination in Egypt from 2012 til...Foot and mouth disease is the most contagious disease of mammals and has a great potential for causing severe economic loss in susceptible cloven-hoofed animals. Routine prophylactic vaccination in Egypt from 2012 till now has been conducted with Trivalent and/or hexavalent vaccine of MERIAL, against virus strains (O manisa + O-3039 + A Iran 05 + A Saudi 95 + Asia 1 + Sat2). This study aimed to evaluate the hemato-biochemical and immunological changes associated with the use of hexavalent vaccine alone or in combination with trivalent FMD vaccine. This study was carried out on 24 cattle divided into three groups eight cattle each. Group I served as control. Group II were selected from farms vaccinated with hexavalent FMD vaccine. Group III were selected from farms vaccinated with a combination of trivalent and hexavalent FMD vaccine. The results showed that both vaccinated groups showed a significant increase in total leukocytic count. Sera from hexavalent-trivalent vaccinated cattle demonstrated a significant increase in serum cortisol concentrations. Significant increase in serum activity of aspartate aminotransferase was recorded in animals vaccinated with a combination of hexavalent and trivalent vaccine. In addition, both regimes resulted in a significant increase in serum blood urea nitrogen compared to control. Both regimes induced a significant increase in serum levels of ceruloplasmin while phagocytic activity of neutrophils and phagocytic index was enhanced only by the hexavalent vaccine. Both vaccinated groups had significantly increased serum values of gamma globulins. These results suggested that hexavalent vaccine produced higher levels of safety and protective effects against FMD in cattle as compared to those produced by a combination of hexavalent and trivalent vaccines. It is also advisable to include the hexavalent vaccine within the program of obligatory and imperative vaccination against FMD.展开更多
The study of trivalent actinide(An(III))interactions with nitrogen and oxygen donor(N,O-donor)extractants is highly relevant to efforts aimed at closing the nuclear fuel cycle.Despite their importance,extraction of tr...The study of trivalent actinide(An(III))interactions with nitrogen and oxygen donor(N,O-donor)extractants is highly relevant to efforts aimed at closing the nuclear fuel cycle.Despite their importance,extraction of transplutonium actinides remains underexplored.A popular N,O-donor extractant,phenanthroline diamide(DAPhen),has incurred interest for f-element separations due to numerous positive qualities such as molar acid stability,a pre-organized binding mode,and tunable amide functionalities.Solvent extraction experiments of TEtDAPhen in nitrobenzene demonstrated selectivity for multiple An(III)(An=Am,Cm,Bk,Cf)metals over Eu(III).展开更多
The preparation process and properties of the thermally prepared Ti anodes coated with IrO2+Ta2O5 was studied. The structure and morphologies of the IrO2+Ta2O5 coatings were determined by XRD and SEM. Their electroche...The preparation process and properties of the thermally prepared Ti anodes coated with IrO2+Ta2O5 was studied. The structure and morphologies of the IrO2+Ta2O5 coatings were determined by XRD and SEM. Their electrochemical properties were studied by polarization curve and cyclic voltammetry. Trivalent chromium electroplating using Ti/IrO2+Ta2O5 anodes is carried out and the results were analyzed. Results show that this anode exhibits excellent electrochemical activity and stability in sulfate electrolysis. The electrocatalytic activity is determined not only by the content of IrO2 but also the structure and morphology of the anode coatings. The electroplating results indicats that Ti/IrO2+Ta2O5 anodes have excellent capabilities and merits in improving the stability of trivalent chromium electroplating in sulfate system.展开更多
Phenanthroline-based tetradentate ligands with hard-soft donors have been the hotspots for the selec-tive separation of minor actinides from lanthanides.Most of the previous studies closely focused on the impact of th...Phenanthroline-based tetradentate ligands with hard-soft donors have been the hotspots for the selec-tive separation of minor actinides from lanthanides.Most of the previous studies closely focused on the impact of the side substituents or different skeletons on the extraction and complexation properties of ligands towards f-elements.Few strategies have been used to modify the hard O-donor atoms.In this work,two new tetradentate N,O-hybrid organophosphorus ligands,Et-Ph-BPPhen(L_(1))and Et-Ph-PIPhen(L2),were synthesized and employed to investigate the impact of the charge properties of O donor atoms.Their extraction properties and complexation behaviours with trivalent actinides and lanthanides were thoroughly studied through solvent extraction,^(1)H/^(31)P NMR titration,UV-vis titration and X-ray single-crystal diffraction measurement.It was found that L_(2)showed a better extraction property and selective separation ability than L_(1).Through the^(1)H/^(31)P NMR spectra titration,only 1:1 metal-to-ligand complexes of two ligands(L_(1)and L2)with La(NO_(3))_(3)were formed.And both 1:1 and 1:2 species were formed for Lu(NO_(3))_(3).The UV-vis titration revealed that both logβvalues of EuL_(1)(6.99±0.04)and Eu(L_(1))_(2)(12.21±0.10)were smaller than those of EuL_(2)(7.04±0.04)and Eu(L_(2))_(2)(12.56±0.08),which was consistent with the extraction results.The stability constants of 1:1 complexes increased along with the lanthanide contrac-tion(from La(NO_(3))_(3)to Lu(NO_(3))_(3)).The single-crystal structures of the complexes of L_(1)and L_(2)with lantha-nides(La(NO_(3))_(3),Eu(NO_(3))_(3)and Lu(NO_(3))_(3))were obtained.The results of the extraction and UV-vis titration were confirmed from the average distances of Eu-O_(L)(L_(1)>L_(2)).As reasonable estimators of selectivity factors,average distances of Eu-N L displayed a particular trend(L_(2)<L_(1)),which corresponded to the pattern of SF(L_(2)>L_(1)).Finally,for a series of crystals concerned with L_(1),the coordination numbers(CNs)reduced along with the lanthanide contraction.These results indicate that the separation ability could be improved by modifying the O donor atoms and phosphinate ligands may be an alternative for the separ-ation of actinides from lanthanides.展开更多
Reduced arene complexes of rare-earth metals are of great interest and importance because of their unique reactivity mimicking low-valence rare-earth metal species.Here,we present the synthesis and structural characte...Reduced arene complexes of rare-earth metals are of great interest and importance because of their unique reactivity mimicking low-valence rare-earth metal species.Here,we present the synthesis and structural characterization of a series of reduced naphthalene or anthracene complexes of mononuclear scandium with mixed C_(5)Me_(5)(Cp^(*))and amidinate ligands.Among them,the reduced anthracene complexes of mononuclear scandium have been found for the first time to undergo a rapid inter-ring rearrangement.Significantly,a reduced anthracene complex with a scandium center attached to the terminal six-membered ring of anthracene was synthesized by modulating the substituents on the amidinate ligand.The diversified two-electron redox reactions of the reduced naphthalene complex of mononuclear scandium toward cyclooctatetraene(COT),dibenzo[a,e]cyclooctene,benzophenone,1,4-diazabutadiene(DAD),isothiocyanate,and selenium were examined.The scope of two-electron redox reactions via the trivalent scandium complex with the mixed Cp^(*)/amidinate/arene ligand system is significantly expanded,and thus,these results remedy the shortcomings where it is difficult for rare-earth complexes to undergo the two-electron redox process.展开更多
In the past few years,phenanthroline-based ligands have become an attractive target for the partitioning of trivalent actinides (Ac) from lanthanides (Ln) in nuclear waste management.However,designing efficient ligand...In the past few years,phenanthroline-based ligands have become an attractive target for the partitioning of trivalent actinides (Ac) from lanthanides (Ln) in nuclear waste management.However,designing efficient ligands for selectively trapping radioactive minor actinides requires complete knowledge of the structure–property relationship to understand the solvent extraction processes in a better way.Therefore,a series of CyMe_(4)BTPhen (2,9-bis(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-1,2,4-benzotriazin-3-yl)-1,10-phenanthroline) derivatives with a five-membered aliphatic ring and a six-membered aliphatic ring have been considered and their complexes with americium and europium [ML(NO_(3))_(3) (L = 1–6)] are studied using scalar relativistic ZORA/DFT calculations.Herein,we envisage the effect of change of a six-membered aliphatic ring to a five-membered aliphatic ring along with the role of substitution of a phenol group on the CyMe_(4)BTPhen ligand.All ligands show preferential binding towards Am^(3+) as compared to the Eu^(3+) ion.The calculated thermodynamic properties and the separation factors indicate that the five-membered aliphatic ring has the highest selectivity for the Am^(3+) ion.Energy decomposition analysis has been carried out to understand the total binding energy with its various energy components,while the nature of interactions between metal and ligand is addressed by QTAIM analysis.The results reveal that ligands with six-membered aliphatic rings and phenol substitution at the 5 and 6 positions are the best bet for stripping actinide ions compared to other designed ligands.In summary,this study offers insights into the structure–binding ability relationship to design efficient candidates for nuclear waste management.展开更多
Major outbreaks of severe acute respiratory syndrome(SARS)and coronavirus disease 2019(COVID-19),together with the continuous risk of zoonotic spillover of animal sarbecoviruses,underscore the urgent need for vaccines...Major outbreaks of severe acute respiratory syndrome(SARS)and coronavirus disease 2019(COVID-19),together with the continuous risk of zoonotic spillover of animal sarbecoviruses,underscore the urgent need for vaccines that confer broad protection across the sarbecovirus subgenus.Current immunogen selection strategies for pansarbecovirus vaccine development predominantly rely on phylogenetic or spike sequence conservation analyses,which often fail to accurately predict the breadth of cross-neutralization.To overcome this limitation,we systematically evaluated cross-neutralization profiles among 25 representative sarbecoviruses from clades 1 and 3 via guinea pig antisera individually raised against full-length spike proteins in pseudovirus neutralization assays while excluding clade 2 viruses lacking known receptor usage.Neutralization profiling revealed four distinct immunogenic clusters that diverged from traditional phylogenetic relationships.Antisera induced by the palm civet-derived SARS-CoV-1 strain SZ1 broadly neutralized all clade 1a viruses,whereas full coverage of clade 1b viruses required at least two distinct immunogens.Remarkably,sera elicited by multiple clade 1 immunogens also neutralized clade 3 viruses despite no prior exposure to clade 3 antigens.Guided by these findings,we proposed a minimal trivalent immunogen combination—SZ1,SARS-CoV-2,and PCoV-GX—that elicited broad neutralization against both clade 1 and clade 3.This rational approach eliminates the need for additional clade 3-specific antigens and provides a preclinical framework for developing next-generation pansarbecovirus vaccines.展开更多
基金funded by Medical and Health Science and Technology Project of Zhejiang province(Grant number:2023KY633).
文摘Objective:To evaluate the cost-effectiveness of annual trivalent inactivated influenza vaccine(IIV3)under the context of Zhejiang province.Methods:A state transition simulation model was constructed to estimate the health and economic outcomes of IIV3 vaccination program compared to no vaccination for hypothetical cohorts of Zhejiang province stratified by age and risk status.Model input parameters were chosen based on published literatures and expert advices.The analysis used societal perspectives and a one-year time horizon,and permanent outcomes were also included.The primary outcome was the incremental cost-effectiveness ratio(ICER),with expression of US dollars per quality adjusted life years(QALYs)gained.Results:In subgroups not at high risk for influenza-related complications(non-high risk subgroup),ICER ranged from $6268/QALY(for adults aged 50-64 years)to $11260/QALY(for children aged from 6 months to 4 years).In subgroups at high risk for influenza-related complications(high risk subgroup),ICER ranged from cost-saving(adults aged≥65 years)to $5260/QALY(for children aged from 6 months to 4 years).ICER were most sensitive to changes in probability of influenza illness,cost of hospitalization,and probability of death for adults aged 18-49 years with non-high risk status.Conclusions:ICERs of annual influenza vaccination varied by age and risk status but were less than the Gross Domestic Product(GDP)per capita of Zhejiang province($17745 in 2023),which remained cost-effective for all-age and different risk status groups from a societal perspective.
基金supported by the National Key Research and Development Program of China(2021YFD1800200)the Laboratory for Lingnan Modern Agriculture Project(NT2021007)the China Agriculture Research System of the MOF and MARA(CARS-41-G12)。
文摘Some H5 viruses isolated in poultry or wild birds between 2020 and 2021 were found to be antigenically different from the vaccine strains(H5-Re11 and H5-Re12) used in China. In this study, we generated three new recombinant vaccine seed viruses by using reverse genetics and used them for vaccine production. The vaccine strain H5-Re13 contains the hemagglutinin(HA) and neuraminidase(NA) genes of an H5 N6 virus that bears the clade 2.3.4.4 h HA gene, H5-Re14 contains the HA and NA genes of an H5 N8 virus that bears the clade 2.3.4.4 b HA gene, and H7-Re4 contains the HA and NA genes of H7 N9 virus detected in 2021. We evaluated the protective efficacy of the novel H5/H7 trivalent inactivated vaccine in chickens, ducks, and geese. The inactivated vaccine was immunogenic and induced substantial antibody responses in the birds tested. Three weeks after vaccination, chickens were challenged with five different viruses detected in 2020 and 2021: three viruses(an H5 N1 virus, an H5 N6 virus, and an H5 N8 virus) bearing the clade 2.3.4.4 b HA gene, an H5 N6 virus bearing the clade 2.3.4.4 h HA gene, and an H7 N9 virus. All of the control birds shed high titers of virus and died within 4 days post-challenge, whereas the vaccinated chickens were completely protected from these viruses. Similar protective efficacy against H5 viruses bearing the clade 2.3.4.4 h or 2.3.4.4 b HA gene was observed in ducks and geese. Our study indicates that the newly updated H5/H7 vaccine can provide solid protection against the H5 and H7 N9 viruses that are currently circulating in nature.
基金This work was supported by the National Key R&D Program of China(2016YFD0501602,2017YFD0500701,and 2016YFEO203200)the National Natural Science Foundation of China(3167131307)+1 种基金the China Agriculture Research System(CARS-41-G12)and Central Publicinterest Scientific Institution Basal Research Fund(1610302017001).
文摘We developed an H5/H7 trivalent inactivated vaccine by using Re-11, Re-12, and H7-Re2 vaccine seed viruses, which were generated by reverse genetics and derived their HA genes from A/duck/Guizhou/S4184/2017(H5N6) (DK/GZ/S4184/17) (a clade 2.3.4.4d virus), A/chicken/Liaoning/SD007/2017(H5N1) (CK/LN/SD007/17) (a clade 2.3.2.1d virus), and A/chicken/ Guangxi/SD098/2017(H7N9) (CK/GX/SD098/17), respectively. The protective efficacy of this novel vaccine and that of the recently used H5/H7 bivalent inactivated vaccine against different H5 and H7N9 viruses was evaluated in chickens. We found that the H5/H7 bivalent vaccine provided solid protection against the H7N9 virus CK/GX/SD098/17, but only 50–60% protection against different H5 viruses. In contrast, the novel H5/H7 trivalent vaccine provided complete protection against the H5 and H7 viruses tested. Our study underscores the importance of timely updating of vaccines for avian influenza control.
文摘The aim of this study is to evaluate the effect of various molar ratios of glycine to chromium salt(Gly:Cr)and different current densities on the corrosion and wear behaviors of Cr(III)electroplated coatings.The morphology and thickness of the coatings were investigated by scanning electron microscopy.The wear properties of the coatings were studied using pin on disk and hardness tests,while corrosion behavior of the coatings was identified using linear polarization,small amplitude cyclic voltammetry,and electrochemical impedance spectroscopy methods.By increasing the glycine concentration,a structure with low crack density was obtained.In all molar ratios,maximum thickness and current efficiency was observed at a current density of 150 mA·cm?2.All the electrochemical methods had a consistent result,and maximum corrosion resistance of approximately 16000Ω·cm2 was obtained in the case of Gly:Cr=3:1 and current density of 200 mA·cm?2.
文摘The formulation of hard chromium plating from trivalent chromium electrolyte and its related process have been intensively studied in this work. Through optimized conditions, the coating hardness can achieve more than HV0.1900 without any treatment and HV0.11700 after heat treatment for five minutes at 300°C, and the thickness of hard chromium coating was about 100 μm. The hard chromium coatings show good adhesion on the carbon steel and low alloy structural steel. The corrosion resistance of hard chromium coatings was enhanced by the adding nanometer materials into trivalent chromium plating coatings. More than 120 hours salt spray corrosion resistance can be achieved with 40 to 50 microns thickness of trivalent chromium plating coatings.
基金the Natural Science Foundation of Shannxi ,China (2005E103)
文摘The lanthanum trivalent ion doped TiO2 nanopowders were prepared by liquid plasma spray with solution of titanium tetra-tert-butoxide and alcohol as feedstock and La(NO3)3·6H2O as doping component. The photocatalytic activity of samples at different doping concentrations in photocatalytic degradation of methyl orange was discussed. The powders were characterized by Transmission Electron Microscopy (TEM) and X-Ray Diffraction (XRD), and the effect of doped ion on the pattern, phase composition and crystallite sizes were analyzed. The results indicated that lanthanum trivalent ion doped TiO2 nanopowders could be prepared by liquid plasma spray. Lanthanum trivalent ion doping increased the photocatalytic activity of TiO2 greatly, the optimal doping concentration was 0.5%. The doped powders were the mixture of anatase phase and rutile phase. The contents of anatase phase decreased firstly and then increased with an increase in the contents of lanthanum trivalent ion. Doping lanthanum trivalent ion could make the TiO2 nanopowders uniform and reduced its particle size.
文摘Considering aviation and space sectors, aluminium alloys are commonly used due to its excellent mechanical and physical properties. Though satellite hard-ware is confined to controlled environment, it requires anticorrosive treatment over metal substrate followed by a systematic coating scheme. The trivalent chromium coating was deposited over three aluminium alloys namely AA6063, AA7075 and AA6082. The variation in corrosion resistance property of trivalent chromium over each aluminium alloy has been studied in detail. The Neutral Salt Spray (NSS) test result shows that trivalent chromium coating over AA7075 alloy is affected by pitting corrosion compared to other two alloys. In addition to that, NSS test also proves that thickness of the layer does not have any influence corrosion resistance property of trivalent chromium coating. Furthermore, ions in trivalent chromium coating was identified using Secondary Neutral Mass Spectroscopy (SNMS) and degradation of coating in a corrosive liquid studied using Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) instrument to understand mechanism of corrosion. The results indicated that both coating and substrate is involved in corrosion process. The number of elements dissolved in to salt solution reveals the weak ionic bonding of coating towards substrates. In comparison, AA7075 alloy has weaker bonding than AA6082 and AA6063 series. The alloying elements such as zinc and copper are removed from substrate by corrosive solution.
文摘Alkaloids are natural, semisynthetic or synthetic organic compounds, normally polar with basic chemical properties and containing at least one nitrogen atom in a heterocyclic ring. Some synthetic or semisynthetic substances resemble the alkaloid architecture. Trivalent nitrogen in these substances is normal;however, some natural and semisynthetic alkaloids have pentavalent nitrogen. The drug pholcodine is a derivative of morphine. Pholcodine has very little addiction- developing effect. It is a semisynthetic alkaloid that was first synthesized in 1950 by Chabrier et al. Pholcodine possesses antitussive (cough relief) properties similar to codeine, morphine and ethylmorphine. The drug was used in liquid formulations as Tuxi and Tuxi Forte, and it is in present use in Tuxidrin as liquid mixture and in tablet form. Pholcodine is an Active Pharmacological Ingredient (API) in tablets and liquid mixtures. Leiras International and Weifa in Norway manufacture medical forms with pholcodine. Several impurities in pholcodine were described by J. Roe in 1997 and by Denk et al. in 2000 and 2002. In addition, several degradation products may be formed in liquid formulations under storage. Some of these products are related not to the original production of pholcodine but rather to its oxidation under storage. The appearance of degradation products strongly depends on the storage temperature and pH of the liquid phase. Pholcodine-N-oxide and pholcodine-N,N’-dioxide are among the degradation (oxidation) products;pholcodine can also degrade to morphine. There is little information about the toxicity of the N-oxide and no information on the N,N’-di- oxide of pholcodine. In this study, the fact that morphine is generated during the storage of formulations containing pholcodine is presented. Another antitussive mixture under the name Cosylan was analyzed to examine the oxidation of ethylmorphine to ethylmorphine-N-oxide. Ethylmorphine is the API in Cosylan.
基金the National Natural Science Foundation of China(No 20571057)the Natural Science Foundation of Zhe-jiang Province(No Y405078)
文摘Hydrothermal reaction of terbium（ Ⅲ） chloride with 5-sulfoisophthalic acid monosodium salt and 1,10-phenanthroline（phen） at 415 K resulted in the formation of a novel coordination polymer, [ Tb （sip） （phen） （H2O） ],（sip =5-sulfoisophthalate trivalent anion） with a three-dimensional network structure. Each centrosymmetrically related pair of terbium ions axe linked by two sip anions, forming a binuclear unit, and each binuclear unit links to four adjacent tetranuclear units, extending a two-dimensional hybrid layer at crystallographic bc plane. On the other hand, every three-terbium ion is connected by three sip anions, generating a trinuclear ring, and the trinuclear ring connects six neighboring trinuclear rings to produce another two-dimensional layer at crystallographic ab plane. Moreover, each sip anion acts as a pontadentate bridge, interconnecting two different types of layers to yield a novel three-dimensional framework.
基金Supported by the Natural Science Foundation of Zhejiang Province(No. 2 0 2 137)
文摘The title complex [(phen) 2Cu(Htcb)Cu(phen) 2]H 3tcb(tcb=1,2,4,5-benzenetetracarboxylato tetravalent anion; phen=1,10-phenanthroline) was synthesized by the hydrothermal synthesis method. The crystal structure was determined by single-crystal X-ray diffraction analysis. It crystallizes in the triclinic system with space group P1, a=1.04174(8) nm, b=1.07119(8) nm, c=1.26360(10) nm, α=98.169(2)°, β=99.679(10)°, γ=93.658(10)°, V=1.37031(18) nm3, Z=1. The two copper(Ⅱ) cations are bridged by Htcb in the monodentate fashion, and have the same five-coordinated environment completed by the four N atoms from the two phen molecules and one O atom from the carboxylic group of Htcb respectively, which can be best described as distorted trigonal-bipyramid geometry. Moreover, the three dimensional network is formed by H-bonding interactions [O…O distance from 0.2506(10) nm to 0.3176(11) nm] and π-π stacking interactions between the phen rings of adjacent binuclear entities with a face-to-face separation of ca. 0.354 nm.
文摘Ulcerative colitis (UC) has reactive oxygen species (ROS) and immunologic pathways implicated in its pathogenesis. The search for new therapeutic protocols in managing UC is tailored in suppressing or preventing these pathways. The influence of trivalent chromium (Cr3+), an essential mineral on experimental colitis was investigated. Mice were grouped into 3;group 1 (control) received clean drinking water while groups 2 and 3 received 10 and 100 ppm Cr3+ respectively for 12 weeks through drinking water. After Cr3+ administration, 5 animals per group were sacrificed on day 0. Thereafter, experimental colitis was induced intra-rectally using acetic acid (4%, 0.3mL) and 5 mice per group were subsequently sacrificed on days 3, 7 and 14. Blood and colonic tissues were obtained and processed appropriately. Blood Cr3+ level, haematological variables, gross and microscopic colitis scores, colonic myeloperoxidase (MPO), Superoxide Dismutase (SOD) and malondialdehyde (MDA) levels were determined using standard methods. Colon cytokine mRNA genes were quantified using real-time PCR. There was a significant decrease in colon gross and histology scores on days 3 and 7 in chromium treated compared with control. The MPO and MDA in chromium groups reduced significantly compared with control while SOD activities increased significantly in Cr3+ groups compared with control. Total RNA increased in chromium groups compared with control on day 3 post-colitis. There was up-regulation of IL-10, down-regulation of TNF-α and IFN-λ in chromium administered groups compared with control. Chromium enhanced healing of colitis by suppression of ROS, inflammation and promotion of antioxidant activities.
文摘In the paper “Supercritical Fluid Chromatography-Mass Spectrometry (SFC-MS) and MALDI-TOF-MS of Heterocyclic Compounds with Trivalent and Pentavalent Nitrogen in Cough Relief Medical Forms Tuxi and Cosylan” [1], the presence of morphine and other degradation products of pholcodine in cough relief medical forms of Tuxi are discussed. Tuxiis recalled from the Norwegian market by Weifa pharmaceutical company, and hence it no longer presents problems to users and health authorities there;however, the medical form Tuxidrin, which contains a significant amount of pholcodine as the active pharmacological ingredient, is still marketed. In the present paper, Tuxidrin is analyzed to determine the presence of degradation products of pholcodine. The degradation of pholcodine to morphine has been discussed previously as a factor in the development of addiction to narcotics in young persons. The structures of the contaminants in Tuxidrin, such as oxides of pholcodine, are elucidated in the present paper. The toxicity and pharmacology of oxides of alkaloids have generally not been well studied, and very little is known about the toxicity and pharmacology of the degradation (oxidation) products of pholcodine: the N-oxide and the N, N'-dioxide of pholcodine. According to Brondz and Brondz[1], the N-oxide and possibly also the N, N'-dioxide are less toxic than the original alkaloids and possess greater pharmacological activity, and hence they may be a source of useful new semisynthetic drugs. The question of possible addiction to pholcodine oxides has not been studied, and the potential of these substances to provoke allergies is unclear. The recall of Tuxi from the Norwegian marketis mainly based on the fact that pholcodine causes significantly increased levels of IgE antibodies in sensitized patients. Tuxidrin contains pholcodine and has the same negative effect as Tuxi, namely provoking allergies or even anaphylactic shock. From this point of view, Tuxidrin has no advantage over Tuxi. These two medical forms only differ in one respect: Tuxidrin requires a prescription (prescription duty medicine), but Tuxi doesnot (prescription free medicine). This aspect is also discussed in the present paper.
文摘The reaction of Os(RL1)(PPh3)2(CO)Br, 1b, with qui-nolin-8-ol (HQ), 2, has furnished complexes of the type [Os(RL2)(PPh3)2(CO)(Q)], 3, in excellent yield (RL1 is C6H2O-2-CHNHC6H4R(p)-3-Me-5, RL2 is C6H2OH-2-CHNC6H4R(p)-3-Me-5 and R is Me, OMe, Cl). In this process, quinolin-8-olato (Q) undergoes five-membered chelation, the iminium-phenolato function tautomerizing to the imine-phenol function. The trans geometry of the Os(PPh3)2 fragment is consistent with the occurrence of a single 31P resonance near –6.0 ppm in 3. In dichloromethane solution, 3 displays a quasireversible 3+/3 couple near 0.40 V vs. SCE (3+ is the osmium (III) analogue of 3). Coulometrically generated solutions of 3+ displays a strong absorption near 340 nm, 415 nm and 500 nm and are one-electron paramagnetic (low-spin d5, S = 1/2) and show rhombic EPR spectra in 1:1 dichloromethanetoluene solution at 77 K with g values near 2.44, 2.20, 1.83. Distortion parameters using the observed g values have been computed. Solutions of 3 absorb near 420 nm and emit near 510 nm at 298 K and 580 nm at 77 K. The fluorescence is believed to originate from the 3MLCT state.
文摘Foot and mouth disease is the most contagious disease of mammals and has a great potential for causing severe economic loss in susceptible cloven-hoofed animals. Routine prophylactic vaccination in Egypt from 2012 till now has been conducted with Trivalent and/or hexavalent vaccine of MERIAL, against virus strains (O manisa + O-3039 + A Iran 05 + A Saudi 95 + Asia 1 + Sat2). This study aimed to evaluate the hemato-biochemical and immunological changes associated with the use of hexavalent vaccine alone or in combination with trivalent FMD vaccine. This study was carried out on 24 cattle divided into three groups eight cattle each. Group I served as control. Group II were selected from farms vaccinated with hexavalent FMD vaccine. Group III were selected from farms vaccinated with a combination of trivalent and hexavalent FMD vaccine. The results showed that both vaccinated groups showed a significant increase in total leukocytic count. Sera from hexavalent-trivalent vaccinated cattle demonstrated a significant increase in serum cortisol concentrations. Significant increase in serum activity of aspartate aminotransferase was recorded in animals vaccinated with a combination of hexavalent and trivalent vaccine. In addition, both regimes resulted in a significant increase in serum blood urea nitrogen compared to control. Both regimes induced a significant increase in serum levels of ceruloplasmin while phagocytic activity of neutrophils and phagocytic index was enhanced only by the hexavalent vaccine. Both vaccinated groups had significantly increased serum values of gamma globulins. These results suggested that hexavalent vaccine produced higher levels of safety and protective effects against FMD in cattle as compared to those produced by a combination of hexavalent and trivalent vaccines. It is also advisable to include the hexavalent vaccine within the program of obligatory and imperative vaccination against FMD.
基金supported by the U.S.Department of Energy Office of Science,Office of Basic Energy Sciences,and Colorado School of Mines under award number DE-SC0020189(E.M.A.,S.S.G.,J.A.J.,and J.C.S.)We thank the U.S.Department of Energy,Office of Science,Office of Basic Energy Sciences,Heavy Element Chemistry program(2020LANLE372)(J.C.G.,B.L.H.,J.G.K,S.A.K.)+1 种基金the US Department of Energy,National Nuclear Security Association(NNSA),Plutonium Modernization Program(NA-191,B.N.L.)for funding the synthesis and characterization of Am(TEtDAPhen)(NO3)3 complexAdditional support for this effort came from LANL’s LDRD projects(20220054DR)for characterization measurements.
文摘The study of trivalent actinide(An(III))interactions with nitrogen and oxygen donor(N,O-donor)extractants is highly relevant to efforts aimed at closing the nuclear fuel cycle.Despite their importance,extraction of transplutonium actinides remains underexplored.A popular N,O-donor extractant,phenanthroline diamide(DAPhen),has incurred interest for f-element separations due to numerous positive qualities such as molar acid stability,a pre-organized binding mode,and tunable amide functionalities.Solvent extraction experiments of TEtDAPhen in nitrobenzene demonstrated selectivity for multiple An(III)(An=Am,Cm,Bk,Cf)metals over Eu(III).
文摘The preparation process and properties of the thermally prepared Ti anodes coated with IrO2+Ta2O5 was studied. The structure and morphologies of the IrO2+Ta2O5 coatings were determined by XRD and SEM. Their electrochemical properties were studied by polarization curve and cyclic voltammetry. Trivalent chromium electroplating using Ti/IrO2+Ta2O5 anodes is carried out and the results were analyzed. Results show that this anode exhibits excellent electrochemical activity and stability in sulfate electrolysis. The electrocatalytic activity is determined not only by the content of IrO2 but also the structure and morphology of the anode coatings. The electroplating results indicats that Ti/IrO2+Ta2O5 anodes have excellent capabilities and merits in improving the stability of trivalent chromium electroplating in sulfate system.
基金support from the National Natural Science Foundation of China(No.U2067213)the Natural Science Foundation of Zhejiang Province(LR21B060001).
文摘Phenanthroline-based tetradentate ligands with hard-soft donors have been the hotspots for the selec-tive separation of minor actinides from lanthanides.Most of the previous studies closely focused on the impact of the side substituents or different skeletons on the extraction and complexation properties of ligands towards f-elements.Few strategies have been used to modify the hard O-donor atoms.In this work,two new tetradentate N,O-hybrid organophosphorus ligands,Et-Ph-BPPhen(L_(1))and Et-Ph-PIPhen(L2),were synthesized and employed to investigate the impact of the charge properties of O donor atoms.Their extraction properties and complexation behaviours with trivalent actinides and lanthanides were thoroughly studied through solvent extraction,^(1)H/^(31)P NMR titration,UV-vis titration and X-ray single-crystal diffraction measurement.It was found that L_(2)showed a better extraction property and selective separation ability than L_(1).Through the^(1)H/^(31)P NMR spectra titration,only 1:1 metal-to-ligand complexes of two ligands(L_(1)and L2)with La(NO_(3))_(3)were formed.And both 1:1 and 1:2 species were formed for Lu(NO_(3))_(3).The UV-vis titration revealed that both logβvalues of EuL_(1)(6.99±0.04)and Eu(L_(1))_(2)(12.21±0.10)were smaller than those of EuL_(2)(7.04±0.04)and Eu(L_(2))_(2)(12.56±0.08),which was consistent with the extraction results.The stability constants of 1:1 complexes increased along with the lanthanide contrac-tion(from La(NO_(3))_(3)to Lu(NO_(3))_(3)).The single-crystal structures of the complexes of L_(1)and L_(2)with lantha-nides(La(NO_(3))_(3),Eu(NO_(3))_(3)and Lu(NO_(3))_(3))were obtained.The results of the extraction and UV-vis titration were confirmed from the average distances of Eu-O_(L)(L_(1)>L_(2)).As reasonable estimators of selectivity factors,average distances of Eu-N L displayed a particular trend(L_(2)<L_(1)),which corresponded to the pattern of SF(L_(2)>L_(1)).Finally,for a series of crystals concerned with L_(1),the coordination numbers(CNs)reduced along with the lanthanide contraction.These results indicate that the separation ability could be improved by modifying the O donor atoms and phosphinate ligands may be an alternative for the separ-ation of actinides from lanthanides.
基金work was supported by the National Key R&D Program of China(No.2021YFF0701600)the National Natural Science Foundation of China(No.21725201,21890721,and 22131001).
文摘Reduced arene complexes of rare-earth metals are of great interest and importance because of their unique reactivity mimicking low-valence rare-earth metal species.Here,we present the synthesis and structural characterization of a series of reduced naphthalene or anthracene complexes of mononuclear scandium with mixed C_(5)Me_(5)(Cp^(*))and amidinate ligands.Among them,the reduced anthracene complexes of mononuclear scandium have been found for the first time to undergo a rapid inter-ring rearrangement.Significantly,a reduced anthracene complex with a scandium center attached to the terminal six-membered ring of anthracene was synthesized by modulating the substituents on the amidinate ligand.The diversified two-electron redox reactions of the reduced naphthalene complex of mononuclear scandium toward cyclooctatetraene(COT),dibenzo[a,e]cyclooctene,benzophenone,1,4-diazabutadiene(DAD),isothiocyanate,and selenium were examined.The scope of two-electron redox reactions via the trivalent scandium complex with the mixed Cp^(*)/amidinate/arene ligand system is significantly expanded,and thus,these results remedy the shortcomings where it is difficult for rare-earth complexes to undergo the two-electron redox process.
基金the Department of Science and Technology-Science and Engineering Research Board(DST-SERB)for the Early Career Research award(ref.no.ECR/2017/001147)CE acknowledges the financial support from the DST-SERB-ECR project of RVS.
文摘In the past few years,phenanthroline-based ligands have become an attractive target for the partitioning of trivalent actinides (Ac) from lanthanides (Ln) in nuclear waste management.However,designing efficient ligands for selectively trapping radioactive minor actinides requires complete knowledge of the structure–property relationship to understand the solvent extraction processes in a better way.Therefore,a series of CyMe_(4)BTPhen (2,9-bis(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-1,2,4-benzotriazin-3-yl)-1,10-phenanthroline) derivatives with a five-membered aliphatic ring and a six-membered aliphatic ring have been considered and their complexes with americium and europium [ML(NO_(3))_(3) (L = 1–6)] are studied using scalar relativistic ZORA/DFT calculations.Herein,we envisage the effect of change of a six-membered aliphatic ring to a five-membered aliphatic ring along with the role of substitution of a phenol group on the CyMe_(4)BTPhen ligand.All ligands show preferential binding towards Am^(3+) as compared to the Eu^(3+) ion.The calculated thermodynamic properties and the separation factors indicate that the five-membered aliphatic ring has the highest selectivity for the Am^(3+) ion.Energy decomposition analysis has been carried out to understand the total binding energy with its various energy components,while the nature of interactions between metal and ligand is addressed by QTAIM analysis.The results reveal that ligands with six-membered aliphatic rings and phenol substitution at the 5 and 6 positions are the best bet for stripping actinide ions compared to other designed ligands.In summary,this study offers insights into the structure–binding ability relationship to design efficient candidates for nuclear waste management.
基金supported by the Natural Science Foundation of China(grant no.82172244)the Major Project of Guangzhou National Laboratory(GZNL2024A01019).
文摘Major outbreaks of severe acute respiratory syndrome(SARS)and coronavirus disease 2019(COVID-19),together with the continuous risk of zoonotic spillover of animal sarbecoviruses,underscore the urgent need for vaccines that confer broad protection across the sarbecovirus subgenus.Current immunogen selection strategies for pansarbecovirus vaccine development predominantly rely on phylogenetic or spike sequence conservation analyses,which often fail to accurately predict the breadth of cross-neutralization.To overcome this limitation,we systematically evaluated cross-neutralization profiles among 25 representative sarbecoviruses from clades 1 and 3 via guinea pig antisera individually raised against full-length spike proteins in pseudovirus neutralization assays while excluding clade 2 viruses lacking known receptor usage.Neutralization profiling revealed four distinct immunogenic clusters that diverged from traditional phylogenetic relationships.Antisera induced by the palm civet-derived SARS-CoV-1 strain SZ1 broadly neutralized all clade 1a viruses,whereas full coverage of clade 1b viruses required at least two distinct immunogens.Remarkably,sera elicited by multiple clade 1 immunogens also neutralized clade 3 viruses despite no prior exposure to clade 3 antigens.Guided by these findings,we proposed a minimal trivalent immunogen combination—SZ1,SARS-CoV-2,and PCoV-GX—that elicited broad neutralization against both clade 1 and clade 3.This rational approach eliminates the need for additional clade 3-specific antigens and provides a preclinical framework for developing next-generation pansarbecovirus vaccines.
