Establishing a screening strategy for non-discriminatory reactive blood donors by constructing a predictive model of hepatitis B virus infection status from a single blood center in China.

Background: When employing the transcription-mediated amplification method for screening blood donors, there are some non-discriminatory reactive results which are screening assay reactive but HBV-DNA discriminatory assay negative. This raises concerns regarding the possibility of false positives among donors, which may lead to permanent deferral of blood donors and affect blood supply. This study aimed to elucidate the infection status of these non-discriminatory reactive blood donors and develop and validate a model to predict individualized hepatitis B status to establish an optimal screening strategy. Methods: Supplementary tests were conducted on initial non-discriminating reactive donations to determine their HBV infection status, including repeat testing, viral load, serological marker detection, and follow-up. Primary clinical variables of the donors were recorded. Based on the Akaike information criterion, a stepwise forward algorithm was used to identify the predictive factors for information and construct a predictive model. The optimal screening strategy was determined through cost-effectiveness analysis. Results: At the Blood Center of Zhejiang Province, 435 cases of initial non-discriminatory reactive donations were collected over two successive periods and sub-categorized through repeated testing into the following three groups: non-repeated positive group, non-discriminated positive group, and non-repeated HBV-DNA positive group. The HBV discriminatory rate increased after repeated testing (110/435, 25.29%). According to supplementary tests, the HBV-DNA positivity rate was 65.52% (285/435), and occult HBV infection was a significantly different among groups (χ2 = 93.22, p < 0.01). The HBV serological markers and viral load in the non-repeated positive group differed from those in the other two groups, with a lower viral load and a higher proportion of false positives. The predictive model constructed using a stepwise forward algorithm exhibited high discrimination, good fit, high calibration, and effectiveness. A cost-effectiveness analysis indicated that utilizing repeated discriminatory testing and the predictive model is an extremely beneficial screening approach for non-discriminatory reactive blood donors. Conclusion: Nearly two-third (65.52%) of the non-discriminatory reactive blood donors were HBV-DNA positive. Our innovative approach of constructing a predictive model as a supplementary screening strategy, combined with repeated discriminatory experiments, can effectively identify the infection status of non-discriminatory reactive blood donors, thereby increasing the safety of blood transfusions.

Thermodynamic and Kinetic Activity Descriptors for the Catalytic Hydrogenation of Ketones.

Activity descriptors are a powerful tool for the design of catalysts that can efficiently utilize H2 with minimal energy losses. In this study, we develop the use of hydricity and H- self-exchange rates as thermodynamic and kinetic descriptors for the hydrogenation of ketones by molecular catalysts. Two complexes with known hydricity, HRh(dmpe)2 and HCo(dmpe)2, were investigated for the catalytic hydrogenation of ketones under mild conditions (1.5 atm and 25 °C). The rhodium catalyst proved to be an efficient catalyst for a wide range of ketones, whereas the cobalt catalyst could only hydrogenate electron-deficient ketones. Using a combination of experiment and electronic structure theory, thermodynamic hydricity values were established for 46 alkoxide/ketone pairs in both acetonitrile and tetrahydrofuran solvents. Through comparison of the hydricities of the catalysts and substrates, it was determined that catalysis was observed only for catalyst/ketone pairs with an exergonic H- transfer step. Mechanistic studies revealed that H- transfer was the rate-limiting step for catalysis, allowing for the experimental and computation construction of linear free-energy relationships (LFERs) for H- transfer. Further analysis revealed that the LFERs could be reproduced using Marcus theory, in which the H- self-exchange rates for the HRh/Rh+ and ketone/alkoxide pairs were used to predict the experimentally measured catalytic barriers within 2 kcal mol-1. These studies significantly expand the scope of catalytic reactions that can be analyzed with a thermodynamic hydricity descriptor and firmly establish Marcus theory as a valid approach to develop kinetic descriptors for designing catalysts for H- transfer reactions.

Computational Study of Dehydration and Dehydrogenation of Ethanol on (TiO2)n (n = 2-4) Nanoclusters.

Dehydration and dehydrogenation of an ethanol molecule on (TiO2)n, n = 2-4, nanoclusters were studied at the correlated molecular orbital theory CCSD(T)/aug-cc-pVDZ(-PP(Ti)) level using density functional theory B3LYP/DZVP2-optimized geometries. Physisorption and chemisorption of ethanol at the bridge Ti site on the trimer and tetramer are thermodynamically preferred over these reactions at the Ti site with a terminal Ti═O. Two possible lowest energy reaction coordinates of dehydration were predicted for the dimer and trimer where the ß hydrogen on ethanol transfers to the adjacent terminal oxygen, or to the adjacent bidentate oxygen. Only the latter reaction coordinate was predicted to be the lowest energy one for the tetramer. Removal of ethylene from the (TiO2)nOH2-C2H4 complex for n = 2-4 at 0 K requires 2-7 kcal/mol. For dehydrogenation, transfer of the α hydrogen to the adjacent Ti atom results in the lowest energy reaction coordinate following a proton-coupled electron-transfer (PCET) process. Removal of the acetaldehyde molecule requires 14-26 kcal/mol from the (TiO2)nH2-C2H4O complex. Loss of H2 from the (TiO2)nH2 complex requires 5-8 kcal/mol. Dehydration and dehydrogenation of one ethanol molecule occur below the reactant asymptote for (TiO2)n, n = 2-4, whereas for (WO3)3 and (MoO3)3, two ethanol molecules are required for this process to be below the reactant asymptote. Dehydration of ethanol is thermodynamically preferred over dehydrogenation on (TiO2)n, n = 2-4. There is an approximate linear correlation of metal Lewis acidity with physisorption of ethanol. A quadratic correlation is predicted between the chemisorption barrier of ethanol and the corresponding proton affinity of oxygen to which the proton is being transferred. There are linear correlations between the basicity of the oxygen site and the acidity of the OH group versus the energy to remove C2H4 from that site. The results for the nanoclusters for n = 3 and 4 are consistent with the experimental results for the reactivity of ethanol on Ti5c4+ rutile TiO2 (110) surface sites.

The Neurobase of ambiguity loss aversion about decision making.

In our daily decision-making, there are two confusing problems: risk and ambiguity. Many psychological studies and neuroscience studies have shown that the prefrontal cortex (PFC) is an important neural mechanism for modulating the human brain in risk and ambiguity decision-making, especially the dorsolateral prefrontal cortex (DLPFC). We used transcranial direct current stimulation (tDCS) to reveal the causal relationship between the DLPFC and ambiguity decision-making. We design two experimental tasks involving ambiguity to gain and ambiguity to loss. The results of our study show that there is a significant effect on left DLPFC stimulation about ambiguity to loss, there is an insignificant effect on left DLPFC stimulation about ambiguity to gain, and there is an insignificant effect on right DLPFC stimulation about ambiguity to gain and ambiguity to loss. This result indicates that people are more sensitive to ambiguity loss than ambiguity gain. Further analysis found that the degree of participants' attitudes toward ambiguity loss who received anodal simulation was lower than that who received sham stimulation across the left DLPFC, which means that the subjects had a strong ambiguity loss aversion after the participants received the anodal simulation of the left DLPFC.

Thermodynamics of the Metal Carbonates and Bicarbonates of Mn, Co, Ni, Cu, and Zn Relevant to Mineral Energetics.

The gas phase heats of formation of ground-state MCO3, M(HCO3)2, and M(HCO3)(OH), where M = Mn, Co, Ni, Cu, and Zn, have been predicted using the correlated molecular orbital theory at the CCSD(T) level extrapolated to the complete basis set limit using the Feller-Peterson-Dixon (FPD) approach. Cohesive energies of the carbonates were predicted based on the calculated gas phase and experimental solid heats of formation. Coulombic dissociation energies (CDEs) between metal cations and anions show a near-linear correlation with Shannon metal cation atomic radii, yet no correlation is found with the hardness of these cations. The total reaction dissociation energies (TRDEs) of transition metals are higher than their CDEs for the di-bicarbonates, in contrast to those for Mg and Ca based on our prior work. In addition to differences in the energies needed to prepare the transition metal dications, electron donation from the ligands to the 3d orbitals of open-shell transition metal dications from lone pairs of adjacent O atoms also plays a role. No electron donation from the ligands to the fully occupied 3d orbitals of Zn and Cd was found. Decomposition energies for generating MO, CO2, and/or H2O were calculated. Gas phase metal exchange energies only partially correlate with the electrochemical series for M(s) → M2+(aq). The FPD heats of formation were used to benchmark a range of density functional theory exchange-correlation functionals, including those commonly used in solid-state mineral calculations. None of the functionals provided chemical accuracy agreement (±1 kcal/mol) with the FPD results. The best agreement with the FPD results is predicted for the τ-HCTH functional with an average unsigned error of 8.3 kcal/mol.

The impact of nucleic acid testing to detect human immunodeficiency virus, hepatitis C virus, and hepatitis B virus yields from a single blood center in China with 10-years review.

BACKGROUND: Since 2010, the Blood Center of Zhejiang province, China, has conducted a pilot nucleic acid amplification testing (NAT) screening of blood donors for Hepatitis B virus (HBV), Hepatitis C virus (HCV), and Human immunodeficiency virus (HIV). This study aims to assess the results of NAT testing over 10 years to establish the effects and factors influencing NAT yields of HBV, HCV, and HIV. METHODS: Blood donations from seven different blood services were screened for HBV DNA, HCV RNA, and HIV RNA using 6 mini pools (6MP) or individual donation (ID)-NAT method between August 1, 2010, and December 31, 2019, at the NAT centralized screening center. We compared 3 transcription-mediated amplification (TMA) assays and 2 polymerase chain reaction (PCR) assays. Further, HBV, HCV, and HIV NAT yields were calculated and donor characteristics and prevalence of HBV NAT yields analyzed. Donors with HCV and HIV NAT yield were also followed up. RESULTS: 1916.31 per million donations were NAT screening positive overall. The NAT yields for HBV, HCV, HIV and non-discriminating reactive were 1062.90 per million, 0.97 per million, 1.45 per million, and 850.99 per million, respectively, which varied in the seven blood services and different years. HBV NAT yields were higher than those of HCV and HIV and varied across demographic groups. Risk factors included being male, old age, low education level, and first-time donors. We found no differences in NAT yields of HBV, HCV, and HIV between the 3 TMA and 2 PCR assays; nonetheless, statistically, significant differences were noted between the five assays. CONCLUSION: In summary, NAT screening in blood donations reduces the risk of transfusion-transmitted infections and shortens the window period for serological marker screening. Therefore, a sensitive NAT screening method, ID-NAT workflow, and recruitment of regular low-risk donors are critical for blood safety.

Electronically Excited Complex Formation in Magnesium Cluster-Halogen Atom Reactions.

A near ultraviolet transition of Mg2F has been observed in emission from the reaction between magnesium clusters, most likely Mg3, and fluorine atoms. Because there is little evidence for upper-state internal excitation, the spectrum is assigned assuming that the upper state is quenched to its lowest vibrational levels. Two of possibly three ground-state vibrational frequencies, υ1 = 516 ± 10 cm-1 and υ2 = 104 ± 10 cm-1, have been established. Dispersed laser-induced fluorescence studies extrapolating on the observed chemiluminescence indicate an excited-state symmetric stretch frequency of order 370 ± 30 cm-1. Electronic structure calculations at the CCSD(T)/CBS level predict that the ground state of Mg2F has C2v symmetry and can be described as an Mg2+F- ion pair with two Mg-F bonds. Like the MgF A-X transition that is largely a transition between Mg orbitals, the observed transition in Mg2F is largely between orbitals on the magnesium dimer ion. The asymmetric C∞v Mg2+F- complex is also a minimum and is predicted to be 6.7 kcal/mol higher in energy. Calculated structures for the Mg2Cl isomers are also presented and used to further interpret the experimental results for the reaction of Mg clusters with Cl atoms. In contrast to Mg2F, the ground state of Mg2Cl is a linear C∞v MgMgCl structure with the C2v and D∞h isomers of the MgClMg structure slightly higher in energy.

Characteristic of HBV nucleic acid amplification testing yields from blood donors in China.

BACKGROUND: Nucleic acid amplification testing (NAT) for blood screening has been previously performed in some countries to determine NAT yields. The current study sought to explore the non-discriminating reactive NAT yields using individual-NAT (ID-NAT) and characteristics of HBV NAT yields through a 10-year retrospective analysis in Zhejiang, China. METHODS: Blood donations were analyzed using individual-NAT mode by the transcription-mediated amplification (TMA) method. Supplementary HBV serological tests were performed using chemiluminescent immunoassay, and HBV viral load assay was performed by real-time polymerase chain reaction. Follow-up studies were performed in partial donors with low HBV viral loads. RESULTS: Non-discriminating reactive NAT yields and HBV NAT yields varied in different years. The yields ranged from 853.73 per million to 2018.68 per million and 624.60 per million to 1669.50 per million, respectively. In the 476 NAT yields, 19 were probable window periods (WP), 33 probable occult hepatitis B virus infections (OBIs), 409 were confirmed OBIs and 15 were chronic HBV infections. ID-NAT results were categorized in four groups, and the findings showed that the levels of HBV DNA viral loads were different in the four different groups (χ2 = 275.02, p < 0.01). HBV viral load distribution was significantly different between anti-HBs positive and anti-HBc positive samples (χ2 = 49.429, p < 0.01). Notably, only 42.03% donors were NAT repeated positive in the 138 repeat donors' follow up tests. CONCLUSION: NAT screening of blood donations can reduce the risk of transfusion-transmitted HBV infections. Positive proportions of anti-HBs and anti-HBc are correlated with the HBV viral load level. However, low level of viral load donors pose risks in HBV NAT assays, and show fluctuating state for HBV viral load and leads to non-repeated NAT results during follow up studies.

Different Carbonate Isomers Formed by the Addition of CO2 to M3O6- for M = Ti, Zr, and Hf.

The chemisorption addition of CO2 to M3O6 and M3O6- for M = Ti, Zr, and Hf was examined using couple cluster CCSD(T) theory using density functional theory B3LYP geometries. For neutral M3O6CO2, a bridge chemisorbed tridentate carbonate cluster is the lowest energy for Ti and Zr, and a terminal chemisorbed bidentate carbonate is the lowest energy for Hf. For anionic M3O6CO2-, the lowest energy structure is a terminal chemisorbed bidentate carbonate for all three metals. The use of correlation-consistent weighted core basis sets for the CCSD(T) calculations is shown to be necessary to obtain the correct energy ordering for the isomers. Only for Ti3O6CO2- is a center tridentate carbonate cluster a low energy isomer. The electron affinities of M3O6CO2 are ∼0.2 eV larger than for M3O6. The CO2 chemisorption binding energies increase slightly for M3O6- as compared to those for M3O6.

Elucidation of Bottom-Up Growth of CaCO3 Involving Prenucleation Clusters from Structure Predictions and Decomposition of Globally Optimized (CaCO3)n Nanoclusters.

Low-energy minima structures for (CaCO3)n, n ≤ 28, are predicted using bottom-up genetic algorithms in conjunction with density functional theory electronic structure calculations, in comparison with the frozen and relaxed top-down clusters generated by cuts from the calcite, vaterite, and aragonite crystal structures. Similarities in structural motifs for the bottom-up and relaxed top-down are revealed using a fragment recognition technique. Fragment energy decomposition analysis shows that the bottom-up and relaxed top-down clusters belong to two classes of amorphous clusters with distinct intracluster energy distributions, despite their structural similarity. The bottom-up clusters with >20 formula units are surface stabilized with negative surface energy densities. In contrast, the top-down clusters are interior stabilized with positive surface energy densities. We prove that the sign of the surface energy density determines whether the nucleation reaction energy as a function of nuclear size has a maximum or a minimum. The surface-stabilized bottom-up clusters are proposed to be a type of prenucleation cluster at the minimum of the nucleation reaction energy. A mechanism for mineralization of CaCO3 involving prenucleation clusters and nonclassical growth pathway is proposed on the basis of our theoretical findings, which is consistent with previous titration experiments.

Thermodynamics of Metal Carbonates and Bicarbonates and Their Hydrates for Mg, Ca, Fe, and Cd Relevant to Mineral Energetics.

The heats of formation of the carbonate, bicarbonate, and bicarbonate/hydroxide metal complexes, including hydrates of Mg2+, Ca2+, Fe2+, and Cd2+, and the oxides, dichlorides, and dihydroxides are predicted from atomization energies using correlated molecular orbital theory at the CCSD(T) level extrapolated to the complete basis set limit following the Feller-Peterson-Dixon (FPD) approach. Using the calculated gas phase values and the available experimental solid-state values, we predicted the cohesive energies of selective minerals. The gas phase decomposition energies of MO, CO2, and H2O follow the order Mg ≈ Ca > Cd ≈ Fe and correlate with the hardness of the metal +2 ions. Gas phase hydration energies show that the order is Mg > Fe > Ca ≈ Cd. There are a number of bulk hydrated Mg and Ca complexes that occur as minerals but there are few if any for Fe and Cd, suggesting that a number of factors are important in determining the stability of the bulk mineral hydrates. The FPD heats of formation were used to benchmark a range of density functional theory exchange-correlation functionals, including those commonly used in solid-state mineral calculations. None of the functionals provided chemical accuracy agreement (±1 kcal/mol) with the FPD results. The best agreement to the FPD results is predicted for ωB97X and ωB97X-D functionals with an average unsigned error of 10 kcal/mol. The worst functionals are PW91, BP86, and PBE with average unsigned errors of 32-36 kcal/mol.

Impact of green credit on industrial structure in China: theoretical mechanism and empirical analysis.

Chinese industrial structure is characterized by a large proportion of industries with high energy consumption and high pollution, such as coal, steel, and cement production, and with only a small proportion of green and environment protection industries. In order to optimize this structure, the Chinese government has clearly proposed to upgrade the industrial structure by solving funding problems in the field of environmental protection in the 13th 5-year plan. However, there are no systematic researches on how green credit affects industrial structure and what the corresponding effects are in the current theoretical circle. Therefore, by analyzing current situations of green credit and the industrial structure, this research explores mechanisms concerning the effects of green credit on the industrial structure. Furthermore, this study conducts an empirical research by using a fixed effects model constructed based on sample data from eastern, central, and western China from 2006 to 2016. The results find that (1) green credit mainly influences the industrial structure through capital and funding channels of enterprises. (2) On the whole, China's green credit has significant effects on the transformation of the industrial structure. (3) Influences of green credit in China on the industrial structure are significantly different in each region. In order to effectively upgrade the industrial structure, for the related stakeholders, some effective ways are to establish a sound legal system for green credit, raise depth of understanding on green credit, and implement green credit according to local conditions.

A single-label fluorescent derivatization method for quantitative determination of neurotoxin in vivo by capillary electrophoresis coupled with laser-induced fluorescence detection.

Neurotoxin (NT), a short-chain α-neurotoxin, is the main neurotoxic protein identified from the venom of Naja naja atra. As an effective drug for the analgesis of advanced cancer patients, NT lasts longer than morphine and does not cause addiction. However, achieving a sensitive and high-resolution measurement of NT is difficult because of the extra-low content of NT in vivo. Therefore, developing a novel method to quantify NT is essential to study its pharmacokinetics in vivo. Although NT contains four primary amine groups that could react with the thiourea in fluorescein isothiocyanate (FITC), we developed a simple and reproducible single-label fluorescent derivatization method for NT which is related to the reaction of N-terminal α-amino of NT alone under optimized derivatization conditions. Furthermore, neurotoxin labelled with fluorescein isothiocyanate (NT-FITC) was prepared by high-performance liquid chromatography (HPLC) with a purity value higher than 99.29% and identified by MALDI-TOF/TOF-MS. Finally, NT-FITC could be detected at 0.8 nmol L(-1) in rat plasma using capillary electrophoresis coupled with laser induced fluorescence detection (CE-LIF). In this paper, the established method robustly and reliably quantified NT labelled with FITC via intravenous and intramuscular administrations in vivo. In addition, this work fully demonstrated the pharmacokinetic characteristics of NT in vivo, which could reduce the risk of drug accumulation, optimize therapies, and provide sufficient evidence for the rational use of NT in clinical and research laboratories.

Piperine mediates LPS induced inflammatory and catabolic effects in rat intervertebral disc.

Piperine is an exact of the active phenolic component from Black pepper. It has been reported to have many biological activities including anti-oxidant, anti-inflammatory and anti-tumor effects. Intervertebral disc degeneration (IDD) is a degenerative disease closely relate to inflammation of nucleus pulposus (NP) cells. This study aimed to assess the anti-inflammatory and anti-catabolic effects of piperine in rat intervertebral disc using in vitro and ex vivo analyzes. We demonstrated that piperine could inhibit LPS induced expression and production of inflammatory factors and catabolic proteases in NP cells culture model. It significantly inhibited multiple inflammatory factors and oxidative stress-associated genes (IL-1ß, TNF-α, IL-6, iNOS), MMPs (MMP-3, MMP-13), ADAMTS (ADAMTS-4, ADAMTS-5) mRNA expression and NO production in a concentration-dependent manner. Moreover, piperine could reverse the LPS-induced inhibition of gene expression of aggrecan and collagen-II. Histologic and dimethylmethylene blue analysis indicated piperine could also against LPS induced proteoglycan (PG) depletion in a rat intervertebral disc culture model. Western blot results showed that piperine inhibited the LPS-mediated phosphorylation of JNK and activation of NF-κB. Finally, our results demonstrated the ability of piperine to antagonize LPS-mediated inflammation of NP cells and suppression of PG in rat intervertebral disc, suggesting a potential agent for treatment of IDD in future.