Causal relationship between circulating cytokines and follicular lymphoma: a two-sample Mendelian randomization study.

Follicular lymphoma (FL), derived from germinal centre (GC) B cells, is a kind of systemic neoplasm. Even though FL is indolent, it remains an incurable haematology Neoplasm. Accumulating evidence has suggested that the circulating cytokine is associated with the development of FL, yet the causal relationship between FL and circulating cytokines remains undetermined. Therefore, we conducted a two-sample Mendelian randomization (MR) to confirm the causal link between FL and levels of circulating cytokines with the use of summary data on circulating cytokines and FL. All these data from genome-wide association study were derived from the Genome-wide pQTL mapping which contains 14,824 individuals. FL data were acquired exclusively from FinnGen, where 218,792 individuals (522 cases vs. 218,270 controls) were involved. Various statistical methods, including the inverse variance weighted method (IVW), weighted median (WME), simple model, weighted model (WM) and MR-Egger, were used to evaluate the potential causal connection between circulating cytokines and FL. Sensitivity analysis, which involves the examination of the heterogeneity, pleiotropy, and leave-one-out method, was also performed to ensure more trustworthy results. A bidirectional MR test was performed to evaluate the direction of causal association between circulating cytokines and FL. Combining all the steps of MR analysis, we revealed four causal cytokines: C-X-C motif chemokine ligand 5 (CXCL5), interleukin-15 receptor A (IL15RA), interleukin-20 (IL20), and neurotrophin-3 (NT-3). The risk of FL may be inversely linked to CXCL5 (OR=0.73, CI: 0.545-0.979, P=0.036), IL-15RA (OR=0.669, CI: 0.451-0.993, P=0.046), and IL-20 (OR=0.565, CI: 0.325-0.981, P=0.043) but positively linked to NT-3 (OR=1.872, CI: 1.063-3.297, P=0.03). In addition, in our study, no causal effect of FL on cytokines was demonstrated and no significant heterogeneity and pleiotropy were found. Our research revealed the causal relationship between cytokines and FL, along with both the anti-protective effect of CXCL5, IL-15RA, and IL-20 and the protective effect of neurotrophin-3 on FL. These findings aim to provide new clues regarding the pathogenesis of FL and to extend the potential of circulating cytokines to therapeutic interventions.

CCK+ interneurons contribute to thalamus-evoked feed-forward inhibition in prelimbic prefrontal cortex.

Interneurons in the medial prefrontal cortex (PFC) regulate local neural activity to influence cognitive, motivated, and emotional behaviors. Parvalbumin-expressing (PV+) interneurons are the primary mediators of thalamus-evoked feedforward inhibition across mouse cortex, including anterior cingulate cortex, where they are engaged by inputs from mediodorsal (MD) thalamus. In contrast, in the adjacent prelimbic cortex (PL), we find that PV+ interneurons are scarce in the principal thalamo-recipient layer 3 (L3), suggesting distinct mechanisms of inhibition. To identify the interneurons that mediate MD-evoked inhibition in PL, we combine slice physiology, optogenetics, and intersectional genetic tools in mice of both sexes. We find interneurons expressing cholecystokinin (CCK+) are abundant in L3 of PL, with cells exhibiting fast-spiking (fs) or non-fast-spiking (nfs) properties. MD inputs make stronger connections onto fs-CCK+ interneurons, driving them to fire more readily than nearby L3 pyramidal cells and other interneurons. CCK+ interneurons in turn make inhibitory, peri-somatic connections onto L3 pyramidal cells, where they exhibit cannabinoid 1 receptor (CB1R) mediated modulation. Moreover, MD-evoked feedforward inhibition, but not direct excitation, is also sensitive to CB1R modulation. Our findings indicate that CCK+ interneurons contribute to MD-evoked inhibition in PL, revealing a mechanism by which cannabinoids can modulate MD-PFC communication.Significance Statement Here we use anatomy, slice physiology, and optogenetics to examine how mediodorsal (MD) thalamus evokes feed-forward inhibition in layer 3 of the prelimbic subregion of mouse prefrontal cortex (PFC). We first show that PV+ interneurons are relatively sparse in layer 3 of prelimbic PFC, whereas CCK+ interneurons are prevalent, and we describe the properties of these cells. We then show how MD thalamus preferentially drives a sub-population of fast-spiking CCK+ interneurons to fire more readily than nearby pyramidal cells and other interneurons. Lastly, we show that CCK+ interneurons make peri-somatic inhibitory connections onto pyramidal cells, and both CCK+ and thalamus-evoked inhibition are modulated by CB1 receptors. Our findings identify a novel and unexpected role for CCK+ interneurons in thalamus-evoked inhibition in the PFC.

A Mendelian randomization study on the causal effects of circulating cytokines on the risk of vitiligo.

Background: Accumulating evidence reveals an association between circulating cytokine levels and vitiligo. However, the causal association between circulating cytokine levels and vitiligo remains unrevealed. Methods: We performed a two-sample Mendelian randomization (MR) analysis using a genome-wide association study of the 41 cytokines dataset, which was conducted with 3 Finnish cohorts (n = 8,293). Vitiligo data were acquired from strictly defined vitiligo data collected by FinnGenbiobank analysis, which included 207,613 European ancestors (131 vitiligo patients, 207,482 controls). The inverse-variance weighted (IVW) method, weighted median (WME), simple model, weighted model, and MR-Egger were used to determine the changes in vitiligo pathogenic cytokine taxa, followed by sensitivity analysis, including horizontal pleiotropy analysis. The MR Steiger test evaluated the strength of a causal association, and the leave-one-out method was used to assess the reliability of the results. The possibility of reverse causality was also investigated using a reverse MR study. Results: We observed that rising IL-4 levels generated an enhanced probability of vitiligo in IVW (OR 2.72, 95%CI 1.19-6.22, p = 0.018). According to the results of the MR analysis, there were causal links between IL-4 and vitiligo. Results were steady after sensitivity and heterogeneity analyses. Conclusion: Our research reveals that a genetically determined increased level of circulating IL-4 may be linked to a higher risk of developing vitiligo. The development of innovative treatment approaches (such as tofacitinib or dupilumab) that focus on blocking IL-4 as a novel way of preventing and treating vitiligo is significantly impacted by our findings.

Knowledge about, attitudes toward and acceptance and predictors of intention to receive the mpox vaccine among cancer patients in China: A cross-sectional survey.

This study aimed to investigate the knowledge about, attitudes toward, and acceptance and predictors of receiving the mpox vaccine among Chinese cancer patients. Patients were selected using a convenience sampling method. A web-based self-report questionnaire was developed to assess cancer patients' knowledge, attitudes, and acceptance regarding the mpox vaccine. Multivariate logistic regression analysis was used to determine predictors of acceptance of the mpox vaccine. A total of 805 cancer patients were included in this study, with a vaccine hesitancy rate of 27.08%. Approximately 66% of the patients' information about mpox and the vaccine came from the mass media, and there was a significant bias in the hesitant group's knowledge about mpox and the vaccine. Multivariable logistic regression analysis suggested that retirement; chemotherapy; the belief that the mpox vaccine could prevent disease, that vaccination should be compulsory when appropriate and that the mpox vaccine prevents mpox and reduces complications; the willingness to pay for the mpox vaccine; the willingness to recommend that friends and family receive the mpox vaccine; and the belief that the mpox vaccine should be distributed fairly and equitably were factors that promoted vaccination. The belief that mpox worsens tumor prognosis was a driving factor for vaccine hesitancy. This study investigated the knowledge of cancer patients about mpox and the vaccine, evaluated the acceptance and hesitancy rates of the mpox vaccine and examined the predictors of vaccination intention. We suggest that the government scientifically promote the vaccine and develop policies such as free vaccination and personalized vaccination to increase the awareness and acceptance rate of the mpox vaccine.

Gut dysbiosis impairs intestinal renewal and lipid absorption in Scarb2 deficiency-associated neurodegeneration.

Scavenger receptor class B, member 2 (SCARB2) is linked to Gaucher disease (GD) and Parkinson's disease (PD). Deficiency in the SCARB2 gene causes progressive myoclonus epilepsy (PME), a rare group of inherited neurodegenerative diseases characterized by myoclonus. We found that Scarb2 deficiency in mice leads to age-dependent dietary lipid malabsorption, accompanied with vitamin E deficiency. Our investigation revealed that Scarb2 deficiency is associated with gut dysbiosis and an altered bile acid pool, leading to hyperactivation of FXR in intestine. Hyperactivation of FXR impairs epithelium renewal and lipid absorption. Patients with SCARB2 mutations have a severe reduction in their vitamin E levels and cannot absorb dietary vitamin E. Finally, inhibiting FXR or supplementing vitamin E ameliorates the neuromotor impairment and neuropathy in Scarb2 knockout mice. These data indicate that gastrointestinal dysfunction is associated with SCARB2 deficiency-related neurodegeneration, and SCARB2-associated neurodegeneration can be improved by addressing the nutrition deficits and gastrointestinal issues.

Powdery mildew-induced changes in phyllosphere microbial community dynamics of cucumber.

As an important habitat for microorganisms, the phyllosphere has a great impact on plant growth and health, and changes in phyllosphere microorganisms are closely related to the occurrence of leaf diseases. However, there remains a limited understanding regarding alterations to the microbial community in the phyllosphere resulting from pathogen infections. Here, we analyzed and compared the differences in phyllosphere microorganisms of powdery mildew cucumber from three disease severity levels (0% < L1 < 30%, 30% ≤ L2 < 50%, L3 ≥ 50%, the number represents the lesion coverage rate of powdery mildew on leaves). There were significant differences in α diversity and community structure of phyllosphere communities under different disease levels. Disease severity altered the community structure of phyllosphere microorganisms, Rosenbergiella, Rickettsia, and Cladosporium accounted for the largest proportion in the L1 disease grade, while Bacillus, Pantoea, Kocuria, and Podosphaera had the highest relative abundance in the L3 disease grade. The co-occurrence network analysis of the phyllosphere microbial community indicated that the phyllosphere bacterial community was most affected by the severity of disease. Our results suggested that with the development of cucumber powdery mildew, the symbiotic relationship between species was broken, and the entire bacterial community tended to compete.

Discussion on the recruitment strategy for apheresis platelet donors in Chongqing during a public health emergency.

Objective: This study aimed to analyze the population characteristics of apheresis platelet donors in Chongqing Province and provide a scientific basis for the development of precise and efficient recruitment strategies. The ultimate goal is to increase the number of regular platelet donors in preparation for public health emergencies. Methods: This study involved 53,089 blood donors who donated apheresis platelets to the Chongqing Blood Center from 2020 to 2022. Data regarding age, sex, blood type, education level, occupation, and frequency of blood donation were collected and analyzed to identify factors influencing platelet donation. Results: Between 2020 and 2022, the majority of apheresis platelet donors in Chongqing were aged 25-35 years, with a male-to-female ratio of 2.6:1. The ABO blood group distribution was O > A > B > AB. The apheresis platelet donors mainly consisted of college students, and the donors who had donated only once accounted for the greatest proportion. Conclusion: Based on the population characteristics of apheresis platelet donors in Chongqing, blood collection and supply organizations must refine emergency blood collection and supply plans during public health emergencies. This study underscores the importance of developing precise and efficient recruitment strategies for apheresis platelet donors and expanding the pool of regular apheresis platelet donors. These measures are essential to ensure the timely, safe, and effective use of clinical blood resources during public health emergencies.

Generation of mitochondrial replacement monkeys by female pronucleus transfer.

Mutations in mitochondrial DNA (mtDNA) are maternally inherited and have the potential to cause severe disorders. Mitochondrial replacement therapies, including spindle, polar body, and pronuclear transfers, are promising strategies for preventing the hereditary transmission of mtDNA diseases. While pronuclear transfer has been used to generate mitochondrial replacement mouse models and human embryos, its application in non-human primates has not been previously reported. In this study, we successfully generated four healthy cynomolgus monkeys ( Macaca fascicularis) via female pronuclear transfer. These individuals all survived for more than two years and exhibited minimal mtDNA carryover (3.8%-6.7%), as well as relatively stable mtDNA heteroplasmy dynamics during development. The successful establishment of this non-human primate model highlights the considerable potential of pronuclear transfer in reducing the risk of inherited mtDNA diseases and provides a valuable preclinical research model for advancing mitochondrial replacement therapies in humans.

Multifunctional Umbrella: In Situ Interface Film Forming on the High-Voltage LiCoO2 Cathode by a Tiny Amount of Nanoporous Polymer Additives for High-Energy-Density Li-Ion Batteries.

The LiCoO2 (LCO) cathode is foreseen for extensive commercial applications owing to its high specific capacity and stability. Therefore, there is considerable interest in further enhancing its specific capacity by increasing the charging voltage. However, single-crystal LCO suffers from a significant capacity degradation when charged to 4.5 V due to the irreversible phase transition and unstable structure. Herein, an ultra-small amount (0.5% wt. in the electrode) of multi-functional PIM-1 (a polymer with intrinsic microporosity) additive is utilized to prepare a kind of binder-free electrode. PIM-1 modulates the solvation structure of LiPF6 due to its unique structure, which helps to form a stable, robust, and inorganic-rich cathod-eelectrolyte interphase (CEI) film on the surface of LCO at a high voltage of 4.5 V. This reduces the irreversible phase transition of LCO, thereby enhancing the cyclic stability and improving the rate performance, providing new perspectives for the electrodes fabrication and improving LCO-based high-energy-density cathodes.

A global dataset on species occurrences and functional traits of Schizothoracinae fish.

The Schizothoracinae fish are a natural group of cyprinids widely distributed in rivers and lakes in the Qinghai-Tibetan Plateau (QTP) and adjacent regions. These fish parallelly evolved with the QTP uplift and are thus important for uncovering geological history, the paleoclimatic environment, and the mechanisms of functional adaptation to environmental change. However, a dataset including species occurrences and functional traits, which are essential for resolving the above issues and guiding relevant conservation, remains unavailable. To fill this gap, we systematically compiled a comprehensive dataset on species occurrences and functional traits of Schizothoracinae fish from our long-term field samplings and various sources (e.g., publications and online databases). The dataset includes 7,333 occurrence records and 3,204 records of 32 functional traits covering all the genera and species of Schizothoracinae fish (i.e., 12 genera and 125 species or subspecies). Sampling records spanned over 180 years. This dataset will serve as a valuable resource for future research on the evolution, historical biogeography, responses to environmental change, and conservation of the Schizothoracinae fish.

The crucial role of transient tri-coordinated oxygen in the flow of silicate melts.

The transport properties of high-temperature silicate melts control magma flow and are crucial for a wide variety of industrial processes involving minerals. However, anomalous melt properties have been observed that cannot be explained by the traditional polymerization degree theory, which was derived based on quenched melts. Ab initio molecular dynamics (AIMD) simulations were conducted to investigate the flow mechanism of CaO-Al2O3-SiO2 melts under high temperature atmospheric conditions. By analyzing the dynamic structure of melted silicates and employing molecular orbital theory, we gained a fundamental understanding of the flow mechanism from a chemistry perspective. Transient tri-coordinated oxygen (TO) bonded with one Si and two Al atoms (SiOAl2) was found to be a pivotal intermediate in melt flow and atomic diffusion processes. Frequent chemical transition between TO in SiOAl2 and bridging oxygen (BO) dominated the fluidity of melted silicates. The presence of such transitions is facilitated by the unstable nature of [SiAlO2] 4-membered rings, which are susceptible to instability due to the intense repulsion between the O 2p lone pairs and the excessively bent O-Al-O angle. Additionally, the density of SiOAl2 type TO motif could serve as an indicator to determine the relationship between structure and fluidity. Our results challenge the traditional polymerization degree theory and suggest the need to reassess high-temperature liquid properties that govern processes in the Earth and industry by monitoring transient motifs.

Intestinal lysozyme1 deficiency alters microbiota composition and impacts host metabolism through the emergence of NAD+-secreting ASTB Qing110 bacteria.

The intestine plays a pivotal role in nutrient absorption and host defense against pathogens, orchestrated in part by antimicrobial peptides secreted by Paneth cells. Among these peptides, lysozyme has multifaceted functions beyond its bactericidal activity. Here, we uncover the intricate relationship between intestinal lysozyme, the gut microbiota, and host metabolism. Lysozyme deficiency in mice led to altered body weight, energy expenditure, and substrate utilization, particularly on a high-fat diet. Interestingly, these metabolic benefits were linked to changes in the gut microbiota composition. Cohousing experiments revealed that the metabolic effects of lysozyme deficiency were microbiota-dependent. 16S rDNA sequencing highlighted differences in microbial communities, with ASTB_g (OTU60) highly enriched in lysozyme knockout mice. Subsequently, a novel bacterium, ASTB Qing110, corresponding to ASTB_g (OTU60), was isolated. Metabolomic analysis revealed that ASTB Qing110 secreted high levels of NAD+, potentially influencing host metabolism. This study sheds light on the complex interplay between intestinal lysozyme, the gut microbiota, and host metabolism, uncovering the potential role of ASTB Qing110 as a key player in modulating metabolic outcomes. IMPORTANCE: The impact of intestinal lumen lysozyme on intestinal health is complex, arising from its multifaceted interactions with the gut microbiota. Lysozyme can both mitigate and worsen certain health conditions, varying with different scenarios. This underscores the necessity of identifying the specific bacterial responses elicited by lysozyme and understanding their molecular foundations. Our research reveals that a deficiency in intestinal lysozyme1 may offer protection against diet-induced obesity by altering bacterial populations. We discovered a strain of bacterium, ASTB Qing110, which secretes NAD+ and is predominantly found in lyz1-deficient mice. Qing110 demonstrates positive effects in both C. elegans and mouse models of ataxia telangiectasia. This study sheds light on the intricate role of lysozyme in influencing intestinal health.

Identification of adult resistant genes to stripe rust in wheat from southwestern China based on GWAS and WGCNA analysis.

KEY MESSAGE: In this study, genome-wide association studies combined with transcriptome data analysis were utilized to reveal potential candidate genes for stripe rust resistance in wheat, providing a basis for screening wheat varieties for stripe rust resistance. Wheat stripe rust, which is caused by the wheat stripe rust fungus (Puccinia striiformis f. sp. tritici, Pst) is one of the world's most devastating diseases of wheat. Genetic resistance is the most effective strategy for controlling diseases. Although wheat stripe rust resistance genes have been identified to date, only a few of them confer strong and broad-spectrum resistance. Here, the resistance of 335 wheat germplasm resources (mainly wheat landraces) from southwestern China to wheat stripe rust was evaluated at the adult stage. Combined genome-wide association study (GWAS) and weighted gene co-expression network analysis (WGCNA) based on RNA sequencing from stripe rust resistant accession Y0337 and susceptible accession Y0402, five candidate resistance genes to wheat stripe rust (TraesCS1B02G170200, TraesCS2D02G181000, TraesCS4B02G117200, TraesCS6A02G189300, and TraesCS3A02G122300) were identified. The transcription level analyses showed that these five genes were significantly differentially expressed between resistant and susceptible accessions post inoculation with Pst at different times. These candidate genes could be experimentally transformed to validate and manipulate fungal resistance, which is beneficial for the development of the wheat cultivars resistant to stripe rust.

Machine learning predicts atomistic structures of multielement solid surfaces for heterogeneous catalysts in variable environments.

Solid surfaces usually reach thermodynamic equilibrium through particle exchange with their environment under reactive conditions. A prerequisite for understanding their functionalities is detailed knowledge of the surface composition and atomistic geometry under working conditions. Owing to the large number of possible Miller indices and terminations involved in multielement solids, extensive sampling of the compositional and conformational space needed for reliable surface energy estimation is beyond the scope of ab initio calculations. Here, we demonstrate, using the case of iron carbides in environments with varied carbon chemical potentials, that the stable surface composition and geometry of multielement solids under reactive conditions, which involve large compositional and conformational spaces, can be predicted at ab initio accuracy using an approach that combines the bond valence model, Gaussian process regression, and ab initio thermodynamics. Determining the atomistic structure of surfaces under working conditions paves the way toward identifying the true active sites of multielement catalysts in heterogeneous catalysis.

Causal relationship between gut microbiota and hidradenitis suppurativa: a two-sample Mendelian randomization study.

Background: Accumulating evidence suggests that alterations in gut microbiota composition are associated with the hidradenitis suppurativa (HS). However, the causal association between gut microbiota and HS remain undetermined. Methods: We performed a bidirectional two-sample Mendelian randomization (MR) analysis using genome-wide association study summary data of gut microbiota and hidradenitis suppurativa from the MiBioGen consortium which concluded 18,340 individuals analyzed by the MiBioGen Consortium, comprising 211 gut microbiota. HS data were acquired from strictly defined HS data collected by FinnGenbiobank analysis, which included 211,548 European ancestors (409 HS patients, 211,139 controls). The inverse variance weighted method (IVW), weighted median (WME), simple model, weighted model, weighted median, and MR-Egger were used to determine the changes of HS pathogenic bacterial taxa, followed by sensitivity analysis including horizontal pleiotropy analysis. The MR Steiger test evaluated the strength of a causal association and the leave-one-out method assessed the reliability of the results. Additionally, a reverse MR analysis was carried out to seek for possible reverse causality. Results: By combining the findings of all the MR steps, we identified four causal bacterial taxa, namely, Family XI, Porphyromonadaceae, Clostridium innocuum group and Lachnospira. The risk of HS might be positively associated with a high relative abundance of Clostridium innocuum group (Odds ratio, OR 2.17, p = 0.00038) and Lachnospira (OR 2.45, p = 0.017) but negatively associated with Family XI (OR 0.67, p = 0.049) and Porphyromonadaceae (OR 0.29, p = 0.014). There were no noticeable outliers, horizontal pleiotropy, or heterogeneity. Furthermore, there was no proof of reverse causation found in the reverse MR study. Conclusion: This study indicates that Clostridium innocuum group and Lachnospira might have anti-protective effect on HS, whereas Family XI and Porphyromonadaceae might have a protective effect on HS. Our study reveals that there exists a beneficial or detrimental causal effect of gut microbiota composition on HS and offers potentially beneficial methods for therapy and avoidance of HS.

Multi-modality trajectory prediction with the dynamic spatial interaction among vehicles under connected vehicle environment.

Compared to non-connected vehicle environments, the connected vehicle environment establishes vehicle interconnection through communication technologies, resulting in more complex interaction, network topologies, and large-scale inputs. This complexity renders traditional trajectory prediction models, which rely primarily on inputting historical information of the target vehicle, inadequate for handling the complex and dynamic interactive lane-changing scenarios in connected vehicle environments. In a connected vehicle environment, it is necessary to propose a more targeted and stable lane-changing behavior prediction method based on vehicle traveling characteristics. Taking into account dynamic spatial interaction among vehicles, this study proposes a multi-modality trajectory prediction model called STA-LSTM to perform analysis on the potential interactive behaviors among vehicles under connected vehicle lane-changing scenarios, and specifically to expand the multi-modality feature input of the vehicle trajectory prediction model. The spatial grid occupancy method is used to model the interactions between vehicles. A space-dimensional attention mechanism is introduced to adaptively match the influencing weights of the surrounding vehicles with the target vehicle and to improve the interactive information extraction method. In addition, the attention module is incorporated into the LSTM decoder from the time dimension so that the established model can identify significant historical hidden features during each trajectory decoding process. To account for the uncertainty of trajectory prediction, the vectors of vehicle interactions are incorporated into contextual information to improve the reliability of prediction results and the robustness of the established model. Compared with conventional baseline models, the proposed model exhibited lower root mean square error (RMSE) and negative log-likelihood (NLL) values, and the RMSE values at different prediction times of 1s, 2s, 3s, 4s, and 5s are 0.46m, 1.15m, 1.89m, 2.84m, and 4.05m, respectively. This indicates that the proposed model can accurately predict the interactions between vehicles and the travel paths of surrounding target vehicles.

Operando Mobile Catalysis for Reverse Water Gas Shift Reaction.

Metal atoms on the support serve as active sites for many heterogeneous catalysts. However, the active metal sites on the support are conventionally described as static, and the intermediates adsorbed on the support far away from the active metal sites cannot be transformed. Herein, we report the first example of operando mobile catalysis to promote catalytic efficiency by enhancing the collision probability between active sites and reactants or reaction intermediates. Specifically, ligand-coordinated Pt single atoms (isolated MeCpPt- species) are bonded on CeO2 and transformed into mobile MeCpPt(H)CO complexes during the reverse water gas shift reaction for operando mobile catalysis. This strategy enables the conversion of inert carbonate intermediates on the CeO2 support. A turnover frequency (TOF) of 6358 mol CO2 molPt -1 ⋅ h-1 and 99 % CO selectivity at 300 °C is obtained for reverse water gas shift reaction, dramatically higher than those of Pt catalysts reported in the literature. Operando mobile catalysis presents a promising strategy for designing high-efficiency heterogeneous catalysts for various chemical reactions and applications.

Simultaneous Determination of Transuranium Radionuclides in Urine by Tandem Quadrupole ICP-MS/MS with Mass-Shift Mode Combined with Chemical Separation.

The urine bioassay method for transuranium nuclides (237Np, 239,240,241Pu, 241Am, and 244Cm) is needed to quickly assess the potential internal contamination in emergency situations. However, in the case that the analysis of multiple radionuclides is required in the same sample, time-consuming/tedious sequential analytical procedures using multiple chromatographic separation resins would have to be employed for the separation of every single radionuclide. In this work, a rapid method for the simultaneous determination of transuranium nuclides in urine was developed by using triple quadrupole inductively coupled plasma mass spectrometry (ICP-MS/MS) combined with a single DGA resin column. The chemical behaviors of Np/Pu and Am/Cm on the DGA resin were consistent in 8-10 mol/L HNO3 and 0.005-0.02 mol/L NaNO2 when 242Pu and 243Am were selected as tracers for Np/Pu and Am/Cm yield monitoring. Based on their different reaction rates with O2, 237Np, 239,240,241Pu, 241Am, and 244Cm in the same solution were simultaneously measured by ICP-MS/MS in the same run. The elimination efficiency of 238U+ tailing (7.43 × 10-9), 238U1H16O2+/238U16O2+ (8.11 × 10-8) and cross contamination of 241Pu and 241Am (<1%) were achieved using 10.0 mL/min He-0.3 mL/min O2 even if the eluate was directly measured without any evaporation. The detection limits of transuranium nuclides were at the femtogram level, demonstrating the feasibility of ICP-MS/MS for simultaneous transuranic radionuclides urinalysis. The developed method was validated by analyzing the spiked urine samples.

Characterization of the starch molecular structure of wheat varying in the content of resistant starch.

Resistant starch (RS) is the total amount of starch that is incompletely or not digested and absorbed in the small intestine. It plays a role similar to dietary fibre with beneficial effects for human health. In this study, the RS content of 129 wheat accessions was determined, and the relationship between the several starch physical properties and resistant starch content were analyzed. By comparing the total starch content, amylose starch content, starch chain length distribution, starch crystallization type, starch branching degree, and starch granule morphology between the high RS and low RS content wheat accessions, it was found that the amylose content and RS content were significantly positively correlated. However, in the range of chain length fb 3 (DP ≥ 37), there was a significant negative correlation between amylopectin content and RS content. The surface of starch granules became increasingly smooth as the content of RS increased.

Towards understanding the lower CH4 selectivity of HCP-Co than FCC-Co in Fischer-Tropsch synthesis.

In Fischer-Tropsch synthesis (FTS), the cobalt catalyst has higher C5+ and lower CH4 selectivity in the hcp phase than in the fcc phase. However, a detailed explanation of the intrinsic mechanism is still missing. The underlying reason was explored combining density functional theory, Wulff construction, and a particle-level descriptor based on the slab model of surfaces that are prevalent in the Wulff shape to provide single-particle level understanding. Using a particle-level indicator of the reaction rates, we have shown that it is more difficult to form CH4 on hcp-Co than on fcc-Co, due to the larger effective barrier difference of CH4 formation and C-C coupling on hcp-Co particles, which leads to the lower CH4 selectivity of hcp-Co in FTS. Among the exposed facets of fcc-Co, the (311) surface plays a pivotal role in promoting CH4 formation. The reduction of CH4 selectivity in cobalt-based FTS is achievable through phase engineering of Co from fcc to hcp or by tuning the temperature and size of the particles.