Influence of Selective Carbon 1s Excitation on Auger-Meitner Decay in the ESCA Molecule

Two-dimensional spectral mapping is used to visualize how resonant Auger-Meitner spectra are influenced by the site of the initial core-electron excitation and the symmetry of the core-excited state in the trifluoroethyl acetate molecule (ESCA). We observe a significant enhancement of electron yield for excitation of the COO 1s → π* and CF3 1s → σ* resonances unlike excitation at resonances involving the CH3 and CH2 sites. The CF3 1s → π* and CF3 1s → σ* resonance spectra are very different from each other, with the latter populating most valence states equally. Two complementary electronic structure calculations for the photoelectron cross section and Auger-Meitner intensity are shown to effectively reproduce the site- and state-selective nature of the resonant enhancement features. The site of the core-electron excitation and the respective final state hole locality increase the sensistivity of the photoelectron signal at specific functional group sites. This showcases resonant Auger-Meitner decay as a potentially powerful tool for selectively probing structural changes at specific functional group sites of polyatomic molecules.

Superatomic Aromaticity in Cyclic Superatomic Molecules: Ligand-Protected Penta-Icosahedral [M@Au11]5 (M = Au, Pt) Clusters

Pure or doped gold icosahedra, which can be generally viewed as superatoms, are promising candidates for cluster-assembled structures. As the first large-scale ring-like gold cluster, the report of [Au60Se2(Ph3P)10(SeR)15]+ has arisen much interest, where its Au60 core is composed of five vertex-sharing gold icosahedra in a cyclic way. From electronic characters, this Au60 core is a 40e cyclic penta-superatom network formed by five 8e closed-shell superatoms (S2P6). When more valence electrons are introduced into the penta-superatom network by atomic doping, global delocalized bonds are induced in its bonding framework. In the 42e Au60 core of the [Au60Se2Cl15]- cluster, two extra electrons occupy one delocalized π-bonding orbital formed by super D orbitals of five superatoms, resulting in superatomic π aromaticity. In the 46e [Pt@Au11]5 core of [(Pt@Au11)5Ga2Cl15] cluster, three delocalized super-π bonds are formed, which are organized in the similar way as the aromatic C5H5- molecule. The unveiling of superatomic aromaticity promotes our understanding of the stability of cyclic superatom assemblies and extends the family of superatomic bonding patterns.

[Frontiers and advances in dental caries research]

Dental caries is a prevalent infectious disease caused by microbial metabolism, affecting the hard tissues of teeth. According to data from the Fourth National Oral Health Epidemiological Survey, there is a gradual increase in caries prevalence in China, particularly among children and elderly individuals. As an etiological factor for dental lesions, caries not only impact oral health but also exhibit significant associations with various systemic diseases, suggesting that systemic diseases may serve as potential risk factors of caries development. To effectively implement the plan of national oral health action, researchers investigate the pathogenesis of caries actively while concurrently develop innovative preventive and treatment strategies based on advanced concepts and technologies, aiming to comprehensively enhance China's oral health status. Therefore, this article provides insights into the pathogenesis of caries, its correlation with systemic diseases, as well as cutting-edge research advancements pertaining to novel preventive measures for caries.

[Effect of a novel pH-responsive tertiary amine monomer dodecylmethylaminoethyl methacrylate modified resin adhesive on biofilm formation of Streptococcus mutans and Lactobacillus casei in vitro]

Objective: To explore the application prospect of a new pH-responsive tertiary amine monomer dodecylmethylaminoethyl methacrylate (DMAEM) modified resin adhesive (DMAEM@RA) in the prevention and treatment of secondary caries. Methods: Five percents DMAEM was added to the resin adhesive to synthesize DMAEM@RA for modifying. Streptococcus mutans (Sm) and Lactobacillus casei (Lc) biofilms were cultured on resin adhesive and DMAEM@RA, respectively. The culture systems were set up at pH=7.4, 6.0, 5.5, and 5.0. The antimicrobial activity of DMAEM@RA was evaluated by quantitative PCR. The effects of DMAEM@RA on biofilm thickness, bacterial amount, and extracellular polysaccharides were studied by scanning electron microscope (SEM) and extracellular polysaccharide staining. Real-time fluorescence quantitative PCR was used to study the effect of DMAEM@RA on the expression levels of cariogenic genes in Sm. Results: DMAEM@RA could significantly reduce the amount of Sm and Lc under acidic conditions, especially Lc. At pH=5.0, the logarithm value of co-cultured Sm bacteria [lg (CFU/ml)] in DMAEM@RA group (7.58±0.01) was significantly lower than that in control group (7.87±0.03) (t=14.32, P<0.001), and the logarithm value of Lc bacteria [lg (CFU/ml)] (7.29±0.04) was also significantly lower than that in control group (7.93±0.15) (t=6.93, P=0.002). SEM observed that the bacteria decreased and the cell fragments appeared in DMAEM@RA group. In addition, DMAEM@RA significantly reduced the biomass of extracellular polysaccharides in the dual-species biofilm under acidic conditions. At pH=5.0, the biomass of extracellular polysaccharides in DMAEM@RA group [(25.13±3.14) mm3/mm2] was significantly lower than that in the control group [(42.66±7.46) mm3/mm2] (t=3.75, P=0.020). DMAEM@RA could significantly up-regulate the expressions of gtfB and gtfC genes in Sm under acidic conditions. At pH=5.0, gtfB and gtfC genes were significantly up-regulated by (14.64± 0.44) times and (2.99±0.20) times, respectively (t=-42.74, P<0.001; t=-13.55, P<0.001). Conclusions: The DMAEM@RA has a good antibacterial effect under acidic conditions, demonstrating that it has a good potential to prevent the occurrence and development of secondary caries.

Natural disasters: a comprehensive study using EMDAT database 1995-2022

INTRODUCTION

The frequency, intensity, and geographical reach of natural disasters, fueled in part by factors such as climate change, population growth, and urbanization, have undeniably been escalating concerns around the world.

DESIGN AND METHODS

This is a retrospective analysis of natural disasters recorded in the Emergency Events Database from 1995 to 2022.

RESULTS

Between 1995 and 2022, 11,360 natural disasters occurred, with a mean of 398 per year. Asia experienced the most disasters (4390) and the highest number of casualties (918,198). Hydrological disasters were the most common subgroup (4969), while geophysical disasters led in terms of deaths (770,644). Biological disasters caused the most injuries (2544), particularly in Africa.

CONCLUSION

Recognizing the historical impacts of the various subtypes of natural disasters may help different regions better risk analyze and mitigate the unique risks associated with such events.

HPV-positive clinically advanced squamous cell carcinoma of the urinary bladder (aBSCC): A comprehensive genomic profiling (CGP) study

BACKGROUND

Advanced bladder squamous cell carcinoma (aBSCC) is an uncommon form of urinary bladder malignancy when compared with the much higher urothelial carcinoma incidence. We studied the genomic alteration (GA) landscape in a series of aBSCC based on the association with human papilloma virus (HPV) to determine if differences in GA would be observed between the positive and negative groups.

METHODS

Using a hybrid capture-based FDA-approved CGP assay, a series of 171 aBSCC were sequenced to evaluate all classes of GA. Tumor mutational burden (TMB) was determined on up to 1.1 Mbp of sequenced DNA and microsatellite instability (MSI) was determined on up to 114 loci. Programmed cell death ligand -1 (PD-L1) expression was determined by IHC (Dako 22C3) with negative expression when PD-L1 was 0, lower expression of positivity set at 1 to 49%, and higher expression set at ≥50% expression.

RESULTS

Overall, 11 (6.4%) of the aBSCC were found to harbor HPV sequences (10 HPV16 and 1 HPV 11). HPV+ status was identified slightly more often in women (NS) and in younger patients (P = 0.04); 2 female patients with aBSCC had a prior history of SCC including 1 anal SCC and 1 vaginal SCC. HPV+ aBSCC had fewer GA/tumor (P < 0.0001), more inactivating mutations in RB1 (P = 0.032), and fewer inactivating GA in CDKN2A (P < 0.0001), CDKN2B (P = 0.05), TERT promoter (P = 0.0004) and TP53 (P < 0.0001). GA in genes associated with urothelial carcinoma including FGFR2 and FGFR3 were similar in both HPV+ and HPV- aBSCC groups. MTAP loss (homozygous deletion) which has emerged as a biomarker for PRMT5 inhibitor-based clinical trials was not identified in any of the 11 HPV+ aBSCC cases, which was significantly lower than the 28% positive frequency of MTAP loss in the HPV- aBSCC group (P < 0.0001). MTOR and PIK3CA pathway GA were not significantly different in the 2 groups. Putative biomarkers associated with immunotherapy (IO) response, including MSI and TMB status, were also similar in the 2 groups. PD-L1 expression data was available for a subset of both HPV+ and HPV- cases and showed high frequencies of positive staining which was not different in the 2 groups.

CONCLUSIONS

HPV+ aBSCC tends to occur more often in younger patients. As reported in other HPV-associated squamous cell carcinomas, HPV+ aBSCC demonstrates significantly reduced frequencies of inactivating mutations in cell cycle regulatory genes with similar GA in MTOR and PIK3CA pathways. The implication of HPV in the pathogenesis of bladder cancer remains unknown but warrants further exploration and clinical validation.

The generation of genuine quadripartite Einstein-Podolsky-Rosen steering in an optical superlattice

Einstein-Podolsky-Rosen (EPR) steering is a quantum effect based on quantum entanglement and it is the key resource for building quantum networks because of its useful properties. Based on the criterion for genuine multipartite EPR steering, the genuine quadripartite EPR steering is confirmed and it can be generated by a spontaneous parametric down-conversion cascaded process with two sum-frequency generations in an optical superlattice. This occurs either below the oscillation threshold and without oscillation threshold. The influence of the parameters of cascaded nonlinear process on the quadripartite EPR steering among signal, idler, and two sum-frequency beams are also discussed. Choosing appropriate nonlinear parameters can achieve good quadripartite quantum steering. This scheme of the generation of genuine quadripartite EPR steering has potential applications in quantum communication and computing.

Theoretical study of the saturation and nature of the hydrogen bonds to gold

Traditional hydrogen bonds are well-known to exhibit directionality and saturation. By contrast, gold involved hydrogen bonds (GHBs) have been extensively studied but remain lack of in-depth understanding towards the intrinsic nature and saturation property. This work exemplifies three series of complexes: [L-Au-L]-⋯(HF)n (L = H, CH3, (CH3)3; n = 1-8) containing GHBs to dig into the intrinsic nature with the aid of multiple theoretical analysis methods, finding that the formation of GHB is highly subject to orbital interactions along with steric hindrance. Moreover, the saturation level of GHBs largely depends on the ligand attached to the gold center, since different ligands typically possess varying electron-giving ability and steric volume. This work confirms the coexistence of as many as 6 GHBs for one Au atom and thoroughly studies the saturation level of GHBs, which will provide new insights into GHBs and facilitate future synthesis of more complicated gold complexes.

Temporal Structures in Positron Spectra and Charge-Sign Effects in Galactic Cosmic Rays

We present the precision measurements of 11 years of daily cosmic positron fluxes in the rigidity range from 1.00 to 41.9 GV based on 3.4×10^{6} positrons collected with the Alpha Magnetic Spectrometer (AMS) aboard the International Space Station. The positron fluxes show distinctly different time variations from the electron fluxes at short and long timescales. A hysteresis between the electron fluxes and the positron fluxes is observed with a significance greater than 5σ at rigidities below 8.5 GV. On the contrary, the positron fluxes and the proton fluxes show similar time variation. Remarkably, we found that positron fluxes are modulated more than proton fluxes with a significance greater than 5σ for rigidities below 7 GV. These continuous daily positron fluxes, together with AMS daily electron, proton, and helium fluxes over an 11-year solar cycle, provide unique input to the understanding of both the charge-sign and mass dependencies of cosmic rays in the heliosphere.

High genetic merit dairy heifers grazing low quality forage had similar weight gain and urinary nitrogen excretion to those of low genetic merit heifers

Climate variability and increasing drought events have become significant concerns in recent years. However, there is limited published research on body weight (BW) change of dairy heifers with different genetic merit when grazing on drought impacted pastures in southern Australia. Achieving target body weight (BW) is vital for dairy heifers, especially during critical stages like mating and calving. This study aimed to assess dry matter (DM) intake, BW change, urinary nitrogen excretion, and grazing behaviours of high vs. low genetic dairy heifers grazing pasture during a 43-day experimental period in a drought season. Forty-eight Holstein Friesian heifers grazed on ryegrass-dominant pasture and were divided into two groups based on their high and low Balanced Performance Index (HBPI and LBPI, respectively). Each group was further stratified into six plots, with similar BW, resulting in four heifers per replication group. Data from the five measurement days were averaged for individual cows to analyse the dry matter intake, nitrogen intake and nitrogen excretion. The statistical model included the treatment effect of BPI (H and L) and means were analysed using ANOVA. The pasture quality was poor, with metabolizable energy 9.3 MJ/Kg DM and crude protein 5.9% on a DM basis. Nitrogen intake and urinary nitrogen excretion were significantly higher (p  <  0.05) in HBPI compared to the LBPI. However, despite these differences, the study did not find any advantages of having HBPI heifer grazing on low quality forage in terms of BW performance.

Unraveling the Aromatic Rule of Cyclic Superatomic Molecules in π-Conjugated Compounds

The aromaticity of π-conjugated compounds has long been a confusing issue. Based on a recently emerged two-dimensional (2D) superatomic-molecule theory, a unified rule was built to decipher the aromaticity of cyclic superatomic molecules of π-conjugated compounds from the chemical bonding perspective. Herein, a series of planar [n]helicenes and [n]circulenes, composed of benzene, thiophene, or furfuran, are systemically studied and seen as superatomic molecules ◊On-2◊F2 or ◊On, where superatoms ◊F and ◊O denote π-conjugated units with 5 and 4 π electrons, respectively. The ascertained superatomic Lewis structures intuitively display aromaticity with each basic unit meeting the superatomic sextet rule of benzene, similar to classical valence bond theory, which is favored by the synthesized complex π-conjugated compounds comprising different numbers and kinds of subrings. The evolutionary trend of ring currents and chemical bonding suggests a local ribbon-like aromaticity in these π-conjugated compounds. Moreover, nonplanar helical π-conjugated compounds have the potential to evolve into spring-like periodic materials with excellent physical properties.

[Research advances on allergen component-resolved diagnosis in respiratory allergic diseases]

Allergen component-resolved diagnosis (CRD) is an emerging molecular diagnostic technology, which can further clarify the protein profile of allergen components in allergic patients, achieve accurate detection of allergens, and have great significance and value for the precise prevention and treatment of allergic diseases. In this article, the CRD technology and its research progress in respiratory allergic diseases are introduced, and the importance of CRD in the evaluation, prevention and treatment of respiratory allergic diseases are discussed.

Clashes and crowds: protests, riots, and other mass gathering events in North America 2021-2022

OBJECTIVE

This study aimed to provide an overview of the scope and challenges of historic events and help better prepare emergency healthcare services for future similar mass gathering events.

STUDY DESIGN

This was a retrospective descriptive analysis of protest and conflict events in North America from 2021 to 2022.

INTRODUCTION

Recent protests, riots, and other conflict events in North America have highlighted the increasing challenges hospital-based and prehospital healthcare providers face. This study provides a retrospective descriptive analysis of protest and conflict events in North America from 2021 to 2022, which may aid emergency healthcare services in understanding the scope and challenges of historic events and help better prepare for future similar mass gathering events.

METHODS

Data collection was performed using a retrospective database search through the Armed Conflict Location & Event Data Project (ACLED) database. The ACLED database was searched using the internal database search functions for recorded events that occurred in North America from January 1, 2021 to December 31, 2022. Date, event type, event subtype, the country of incident, and fatality numbers were extracted. The results were exported into an Excel spreadsheet and analyzed independently by L.C., H.S., and R.H.

RESULTS

There were a total of 52,529 recorded events of political conflict in North America, with 30,269 events in 2021 and 29,260 in 2022. Political conflict events included protests (40,934, 68.8%), violence against civilians (11,532, 19.4%), strategic developments (2,819, 4.7%), battles (2,293, 3.9%), riots (1,909, 3.2%), and remote violence (42, 0.1%). Violence against civilians caused the highest fatalities (13,466, 82.6%), followed by battles (2,662, 16.3%), riots (111, 0.7%), strategic developments, remote violence, and protests (57, 6, and 3 respectively).

CONCLUSION

Mexico and the United States accounted for most of the political conflicts in North America across 2021 and 2022. In Mexico, protests and violence against civilians were the most common types of conflict, with the latter accounting for the comparatively high fatality compared with the other countries. Battles in Mexico between cartels were the most deadly political conflicts recorded in North America.

[Clinical effect of the giant deep inferior epigastric artery paraumbilical perforator flap in repairing the circular high-voltage electric burn wounds on the wrist]

Objective: To investigate the clinical effect of the giant deep inferior epigastric artery paraumbilical perforator flap in repairing the circular high-voltage electric burn wounds on the wrist. Methods: A retrospective observational study method was used. From September 2016 to October 2021, thirteen male patients (aged 20-43 years) with annular high voltage (10-100 kV) electrical burns on the wrist were admitted to the Beijing Jishuitan Hospital. At the early stage after injury, the patient's wrist was subjected to incision, tension reduction and debridement, with the wound area after debridement being 27 cm×16 cm-32 cm×19 cm; in 12 patients with vascular injury, the radial or ulnar artery was reconstructed by great saphenous vein transplantation, with the length of 15-25 cm; the wrist wound was repaired by free transplantation of the deep inferior epigastric artery paraumbilical perforator flap (if the wound was giant, the lower abdominal flap carrying other perforators was used), with the area of 30 cm×19 cm-35 cm×20 cm. The donor site was repaired by direct suture+skin grafting or relay flap transplantation. After surgery, the survival of flap in recipient area, as well as survival of the skin or flap in donor site were observed. During follow-up, the appearances of the flap in recipient area and the recovery of hand function, as well as the healing of donor site, occurrence of abdominal wall hernia, and scar in skin graft area were observed. Results: After surgery, all the 13 patients' paraumbilical perforator flaps survived. Among them, 3 patients had subcutaneous fat necrosis at the distal end of the wrist flap, and the wound had mild infection, which healed after re-expansion and dressing change. All the skin grafts in the donor site of 10 patients survived, and the flaps in the donor site of 3 patients survived well. The patients were followed up for 6 months to 3 years. The flaps in recipient area were in good shape, 8 cases had partial recovery of hand function, and 5 cases had loss of finger flexion function; the donor site of abdominal flap healed well with no abdominal hernia occurred, and the skin graft site had no obvious scar hyperplasia and was soft in texture. Conclusions: Early vascular reconstruction after injury, together with free transplantation of the giant deep inferior epigastric artery paraumbilical perforator flap are effective in repairing circular high-voltage electrical burn wounds on the wrist.

Disaggregated Nano-Hydroxyapatite (DnHAP) with Inhibitory Effects on Biofilms and Demineralization

Nano-hydroxyapatite (nHAP) is considered a biocompatible agent that promotes the remineralization of dental hard tissue; however, its antibacterial efficacy is under scientific discussion. Therefore, this investigation aimed to specify the inhibitory effects of disaggregated nano-hydroxyapatite (DnHAP) on regrown biofilms and demineralization. Regrown biofilm models of single-species (Streptococcus mutans), dual-species (S. mutans and Candida albicans), and saliva-derived microcosm biofilms were established in vitro. Repeat treatment with DnHAP was applied to biofilms. The viability, lactic acid, biofilm structure, biomass, the inhibitory effect of demineralization, and virulence factors' expression were determined. In addition, the biofilm microbial community was analyzed by 16S ribosomal RNA gene sequencing. DnHAP inhibited metabolism, lactic acid production, biomass, and water-insoluble polysaccharide production (P < 0.05) of regrown single/dual-species biofilms. Concerning the saliva-derived biofilms, samples treated with DnHAP showed lower biofilm metabolic activity without significant differences from samples treated with sterile deionized water (P > 0.05); in addition, saliva-derived biofilms treated with DnHAP exhibited lower lactic acid production (P < 0.05). The demineralization of bovine enamel was the lowest in the DnHAP group, as detected by transverse microradiography, and the lesion depth and volume decreased significantly (P < 0.05). The application of DnHAP did not change the diversity of regrown saliva-derived microcosm biofilms. In conclusion, this investigation showed that DnHAP could be a promising solution for the management of regrown biofilms to combat dental caries.

[Incidence and prognosis of olfactory and gustatory dysfunctions related to infection of SARS-CoV-2 Omicron strain: a national multi-center survey of 35 566 population]

Objective: This cross-sectional investigation aimed to determine the incidence, clinical characteristics, prognosis, and related risk factors of olfactory and gustatory dysfunctions related to infection with the SARS-CoV-2 Omicron strain in mainland China. Methods: Data of patients with SARS-CoV-2 from December 28, 2022, to February 21, 2023, were collected through online and offline questionnaires from 45 tertiary hospitals and one center for disease control and prevention in mainland China. The questionnaire included demographic information, previous health history, smoking and alcohol drinking, SARS-CoV-2 vaccination, olfactory and gustatory function before and after infection, other symptoms after infection, as well as the duration and improvement of olfactory and gustatory dysfunction. The self-reported olfactory and gustatory functions of patients were evaluated using the Olfactory VAS scale and Gustatory VAS scale. Results: A total of 35 566 valid questionnaires were obtained, revealing a high incidence of olfactory and taste dysfunctions related to infection with the SARS-CoV-2 Omicron strain (67.75%). Females(χ2=367.013, P<0.001) and young people(χ2=120.210, P<0.001) were more likely to develop these dysfunctions. Gender(OR=1.564, 95%CI: 1.487-1.645), SARS-CoV-2 vaccination status (OR=1.334, 95%CI: 1.164-1.530), oral health status (OR=0.881, 95%CI: 0.839-0.926), smoking history (OR=1.152, 95%CI=1.080-1.229), and drinking history (OR=0.854, 95%CI: 0.785-0.928) were correlated with the occurrence of olfactory and taste dysfunctions related to SARS-CoV-2(above P<0.001). 44.62% (4 391/9 840) of the patients who had not recovered their sense of smell and taste also suffered from nasal congestion, runny nose, and 32.62% (3 210/9 840) suffered from dry mouth and sore throat. The improvement of olfactory and taste functions was correlated with the persistence of accompanying symptoms(χ2=10.873, P=0.001). The average score of olfactory and taste VAS scale was 8.41 and 8.51 respectively before SARS-CoV-2 infection, but decreased to3.69 and 4.29 respectively after SARS-CoV-2 infection, and recovered to 5.83and 6.55 respectively at the time of the survey. The median duration of olfactory and gustatory dysfunctions was 15 days and 12 days, respectively, with 0.5% (121/24 096) of patients experiencing these dysfunctions for more than 28 days. The overall self-reported improvement rate of smell and taste dysfunctions was 59.16% (14 256/24 096). Gender(OR=0.893, 95%CI: 0.839-0.951), SARS-CoV-2 vaccination status (OR=1.334, 95%CI: 1.164-1.530), history of head and facial trauma(OR=1.180, 95%CI: 1.036-1.344, P=0.013), nose (OR=1.104, 95%CI: 1.042-1.171, P=0.001) and oral (OR=1.162, 95%CI: 1.096-1.233) health status, smoking history(OR=0.765, 95%CI: 0.709-0.825), and the persistence of accompanying symptoms (OR=0.359, 95%CI: 0.332-0.388) were correlated with the recovery of olfactory and taste dysfunctions related to SARS-CoV-2 (above P<0.001 except for the indicated values). Conclusion: The incidence of olfactory and taste dysfunctions related to infection with the SARS-CoV-2 Omicron strain is high in mainland China, with females and young people more likely to develop these dysfunctions. Active and effective intervention measures may be required for cases that persist for a long time. The recovery of olfactory and taste functions is influenced by several factors, including gender, SARS-CoV-2 vaccination status, history of head and facial trauma, nasal and oral health status, smoking history, and persistence of accompanying symptoms.

Properties of Cosmic-Ray Sulfur and Determination of the Composition of Primary Cosmic-Ray Carbon, Neon, Magnesium, and Sulfur: Ten-Year Results from the Alpha Magnetic Spectrometer

We report the properties of primary cosmic-ray sulfur (S) in the rigidity range 2.15 GV to 3.0 TV based on 0.38×10^{6} sulfur nuclei collected by the Alpha Magnetic Spectrometer experiment (AMS). We observed that above 90 GV the rigidity dependence of the S flux is identical to the rigidity dependence of Ne-Mg-Si fluxes, which is different from the rigidity dependence of the He-C-O-Fe fluxes. We found that, similar to N, Na, and Al cosmic rays, over the entire rigidity range, the traditional primary cosmic rays S, Ne, Mg, and C all have sizeable secondary components, and the S, Ne, and Mg fluxes are well described by the weighted sum of the primary silicon flux and the secondary fluorine flux, and the C flux is well described by the weighted sum of the primary oxygen flux and the secondary boron flux. The primary and secondary contributions of the traditional primary cosmic-ray fluxes of C, Ne, Mg, and S (even Z elements) are distinctly different from the primary and secondary contributions of the N, Na, and Al (odd Z elements) fluxes. The abundance ratio at the source for S/Si is 0.167±0.006, for Ne/Si is 0.833±0.025, for Mg/Si is 0.994±0.029, and for C/O is 0.836±0.025. These values are determined independent of cosmic-ray propagation.

Stabilizing hydrogen-mediated sextuple bonds by quintuple superatomic bonding and a bond

Multiple bond orders of four and five are frequently obtained for d-block elements. However, compounds with sextuple bonding (2σ, 2π, and 2δ), for instance, Cr₂, Mo₂ and W₂, are less stable and trapped only in the gas phase or inert matrices, probably resulting from large repulsion of two σ-type (σ_s and ) orbitals within the same zone. Herein, a superatomic bonding model is proposed to describe experimentally synthesized bridging hydride compounds. We theoretically predicted four unprecedented quintuple bridging hydride species with large E_HL values, among which [(Cp)₂Sc₂(μ-H)₅]^- and [(Cp)₂Mn₂(μ-H)₅]^- (Cp = cyclopentadienyl) contain quintuple superatomic bonding (σ, 2π, and 2δ). In particular, two other species, [(Cp)₂Ti₂(μ-H)₅]^- and [(Cp)₂V₂(μ-H)₅]⁺, were found to feature stable hydrogen-mediated sextuple bonding comprising a quintuple superatomic delocalized bond and an extra localized bond. Thereinto, the superatomic σ_s bond disperses to the outer space for better overlap with the orbitals of bridging H atoms, thus leaving the inner regions with low electron densities and providing adequate space for the bond. These two quintuple bridging hydride compounds are verified to have thermal stability by molecular dynamics simulations and expected to provide an effective strategy to synthesize molecules with stable hydrogen-mediated sextuple bonding under normal experimental conditions.

Compressive Symbol: A New Way to Evaluate the High-Pressure Behaviors of Energetic Tetrazole Materials

Energetic materials may transit to different phases or decompose directly under compression. Their reactivity in the explosions can be evaluated by their high-pressure induced behaviors, including polymorphism or phase transition. Here, we applied DFT methods to understand high-pressure behaviors of four typical tetrazole derivate crystals, including 5-aminotetrazole (ATZ), 1,5-aminotetrazole (DAT), 5-hydrazinotetrazole (HTZ), and 5-azidotetrazole (ADT), under the gradually increased pressure from ambient pressure to 200 GPa. In response to the extreme-high pressures, the performances are dominated by compressibility of crystals, reflected by compressive symbols on the basis of the molecular orientation in crystals. The crystal with weak compressibility (large symbol) generally dissociates, triggered by cleavage of weak bonds. However, the crystal with low compressive symbol is generally corresponding to a pressure-induced structural transformation or phase transition.

Signal-processing electronics for stable and sensitive weak-field atomic vector magnetometers

We present the electronics developed for a sensitive and stable atomic vector magnetometer used in low-field detections. These electronics are required to be not only highly reliable and sophisticated for signal processing but also compact in size and low cost in resource consumption for the purpose of miniaturization. In addition, this magnetometer works with multiple modulations, where the interferences between harmonics of modulation fields often disturb the long-term measurements of the sensor. We work out a robust method to eliminate this problem by choosing the modulation frequencies with separations to match the minimum response points of the low-pass filters used in the demodulation processes. We validate the performance of the electronics and the frequency-selection scheme of the modulation fields with corresponding experimental results.

Temporal Structures in Electron Spectra and Charge Sign Effects in Galactic Cosmic Rays

We present the precision measurements of 11 years of daily cosmic electron fluxes in the rigidity interval from 1.00 to 41.9 GV based on 2.0×10^{8} electrons collected with the Alpha Magnetic Spectrometer (AMS) aboard the International Space Station. The electron fluxes exhibit variations on multiple timescales. Recurrent electron flux variations with periods of 27 days, 13.5 days, and 9 days are observed. We find that the electron fluxes show distinctly different time variations from the proton fluxes. Remarkably, a hysteresis between the electron flux and the proton flux is observed with a significance of greater than 6σ at rigidities below 8.5 GV. Furthermore, significant structures in the electron-proton hysteresis are observed corresponding to sharp structures in both fluxes. This continuous daily electron data provide unique input to the understanding of the charge sign dependence of cosmic rays over an 11-year solar cycle.

Enhanced Stability of Rhombic Dodecahedron Nb15- with Well-Organized Superatomic States

Well-resolved Nb_n^- clusters are produced and reacted with ethene and propene via a downstream flow tube reactor. Interestingly, the Nb_n^- clusters readily react with ethene and propene to form dehydrogenation products; however, Nb₁₅^- shows up in the mass spectra with prominent mass abundance indicating its inertness to react with olefins. For this cluster, we conduct photoelectron velocity map imaging (VMI) experiments and verify the stability of Nb₁₅^- within a highly symmetrical rhombic dodecahedron structure. Theoretical studies show that the stability of the Nb₁₅^- cluster is correlated with its superatomic nature pertaining to both geometric and electronic shell closures. Notably, the superatomic 1s orbital is dominated by the 5s electron of the central Nb atom, while the other superatomic orbitals are contributed by s-d hybridization, especially a remarkable contribution of s-d_z² hybridization. Apart from the closed shells, the highly symmetric geometry of Nb₁₅^- is associated with a regular polyhedral structure directed by all rhombus facets, embodying a magic number for body-centered dodecahedra, indicative of enhanced stability as a double magic cluster free of olefin adsorption.

Unraveling the flexible aromaticity of C13H9+/0/-: a 2D superatomic-molecule theory

Phenalenyl (C₁₃H₉) is the smallest triangular unit of a graphene nanosheet, and has been experimentally verified to be stable in radical (C₁₃H₉˙), cationic (C₁₃H₉⁺), and anionic (C₁₃H₉^-) states. All these three species feature high symmetry and stability as well as delocalized π electrons, a visible sign of aromaticity, but their aromatic origin remains a challenge. This work reports new chemical insights into the π electrons of C₁₃H₉^+/0/- and deciphers their aromaticity using a recently emerged two-dimensional (2D) superatomic-molecule theory. 12π-C₁₃H₉⁺, 13π-C₁₃H₉˙, and 14π-C₁₃H₉^- are seen as triangular 2D superatomic molecules ^◊O₃, ^◊O₃^-, and ^◊O₃^2-, respectively, where ^◊O denotes a 2D benzenoid superatom bearing 4 π electrons. Visualized superatomic Lewis structures show that each ^◊O can dynamically adjust its π electrons to satisfy the superatomic sextet rule of benzene via superatomic lone pairs and covalent bonds. C₁₃H₉^+/0/- are representatives of adaptive aromaticity in the 2D superatomic-molecule system, exhibiting flexible π electronic structures to achieve shell-closure. Moreover, we specially adopt a progressive methodology to study the evolution of 2D periodic materials, by applying this theory to the similar family of C₆H₃N₇, C₁₈H₆N₂₂ and graphitic carbon nitride (g-C₃N₄) crystals, and meanwhile accounting for the special stability of g-C₃N₄. This work enriches 2D superatomic bonding chemistry and provides a useful strategy to design new 2D functional nanostructured materials.

Planar σ-Aromaticity in Ga-Doped Au Clusters

Recently, the first example of Au-Ga clusters is synthesized and characterized, which can be described by the jellium model as a superatom with 8 valence electrons that come from the joint contribution of Au and Ga atoms, opening a whole new field for further research. Here, the structure features and stability of one Ga-doped Au cluster with magic number electrons (6 and 8) are analyzed in detail. Moreover, the valence electron fillings and chemical bonding of them are also further explored. It is found that Au₃Ga and Au₅Ga clusters present planar configurations, and they have higher stability than that of neighbor clusters. The AIMD simulations show that these two clusters still have a good thermal stability at 500 K. The molecular orbital analyses show that the Au₃Ga and Au₅Ga have three and one typical delocalization orbital throughout the whole planar spaces, respectively, following the planar σ-aromaticity rule. The ELF and LOL analyses are further performed, and the results are consistent with the molecular orbital analyses. The NICSzz-scan curves confirm that the Au₃Ga is more aromatic than the Au₅Ga, and the reason is that the former has more delocalized electrons than the latter. Our work opens up aromaticity studies in the Au-Ga clusters.

The nature of stability and adsorption interactions of binary Au-Li clusters with bridge adsorption structures

Earlier findings have confirmed that CO molecules have propensities to adsorb on low-coordinated gold atoms (top sites) of Au-based clusters, which can be treated by the Blyholder model wherein the σ donation and π-back donation take place. Here, the structural features and stability of (AuLi)_n (n = 1-9) clusters were first analyzed using the GA-DFT method. The new adsorption modes, vibration frequencies and electronic interactions for Au-Li clusters with CO were investigated in detail. More excitingly, we found that CO prefers to adsorb on the bridge sites of the Au-Li clusters rather than on the top sites, which are much lower in energies than the top adsorptions, and the C-O stretching frequencies are also red-shifted. AIMD simulations show that the adsorption structures still have good thermal stability at 500 K. The density of states reveals that the electronic structures of Au-Li clusters have excellent stability for the bridge adsorptions of CO molecules. The ETS-NOCV analysis and NPA charges show that the direction of charge flow is from Au-Li clusters → CO. Our study provides an idea to elucidate the new adsorption mechanism on Au-Li clusters and the connection between the geometries and reaction properties.

Dabrafenib and Trametinib Therapy for Advanced Anaplastic Thyroid Cancer - Real-World Outcomes From UK Centres

AIMS

Anaplastic thyroid cancer (ATC) is a rare but aggressive form of thyroid cancer with a median survival of 4 months. Recent advances in molecular profiling have shown that up to half of ATCs harbour the BRAF-V600E mutation. The aim of this study was to provide real-world data and experience on the use of combination therapy dabrafenib and trametinib in patients with BRAF-V600E-mutated advanced ATC.

MATERIALS AND METHODS

We retrospectively evaluated patients with confirmed BRAF-V600E-mutated ATC, defined as patients with locally advanced or metastatic ATC with no locoregional, radical treatment options. Outcomes measured were overall survival, progression-free survival, response rate, discontinuation rate, dose reduction rate and toxicity data.

RESULTS

Seventeen patients were evaluated and the mean age was 68 years. Ten patients died by the time of censoring. The median duration of follow-up was 12 months (3-43 months). The estimated median overall survival was 6.9 months (95% confidence interval 2.46 months - upper confidence interval not reached) and the median progression-free survival was 4.7 months (95% confidence interval 1.4-7.8 months). Dose interruptions and/or reductions were common, but none of the patients had to permanently discontinue treatment because of toxicities. Severe toxicities (grades 3 and 4) were uncommon.

CONCLUSIONS

This study supports the indication of dabrafenib and trametinib in BRAF-V600E-mutated ATC as an effective and well-tolerated treatment in an historically difficult to treat cancer.

[Characteristics and significance of outer retinal thickness changes in reticular macular disease]

Objective: To study the characteristics and significance of changes in the thickness of the outer retinal layer (ORL) outside the macula in patients with reticular macular disease (RMD). Methods: A cross-sectional study was conducted. The clinical data of patients who visited the Department of Ophthalmology of the First Affiliated Hospital of Guangzhou Medical University from February to September 2019 were retrospectively collected. Thirty-one patients with at least one eye (54 eyes in total) diagnosed with early/mid-stage age-related macular degeneration (AMD) were consecutively included in the AMD group, and 33 patients with at least one eye (64 eyes in total) showing subretinal wart-like deposits on optical coherence tomography images were consecutively included in the RMD group. Thirty-two volunteers aged between 50 to 90 years with a normal fundus in both eyes (64 eyes in total) were consecutively included in the healthy control (HC) group. Frequency domain optical coherence tomography was applied to examine and analyze the thickness features of the ORL, inner retinal layer and choroid at the macular fovea (F), 2 mm of the temporal edge (T), the nasal edge (N), the superior edge (S) and inferior edge (I) of the macular fovea in each group. The correlations of the thickness of ORL with the choroidal thickness and the blood flow density of the choriocapillaris layer in patients with RMD were also analyzed. Results: The thickness of ORL at the F, T, S and I sites in the RMD group was significantly thinner than that in the AMD and HC groups. The difference was most obvious at the F site [(90.27±8.93), (98.04±11.7) and (97.19±7.02)μm] in the RMD, AMD and HC groups, respectively; all P<0.01). In the logistic regression model with independent variables of the ORL thickness at the macular F site, gender and age, there was a significant association between the thickness of ORL at the F site and the incidence of RMD (odds ratio=0.926, P<0.05). The ORL and choroid in the eyes of patients with RMD were significantly thinner at the F site [(90.27±8.93) and (163.21±72.43) μm, respectively; both P<0.01] compared with the AMD [(98.04±11.7) and (235.34±64.15) μm, respectively] and HC [(97.19±7.02) and (240.08±62.27) μm, respectively] groups. However, the ORL and choroidal thickness did not show significant and strong linear correlations at multiple sites. In contrast, there was a significant linear correlation between the blood flow density of the choriocapillaris layer and the thickness of ORL at the F, T and S sites in patients with RMD (r=0.487, 0.722, 0.467, respectively; all P<0.05). Conclusions: The thickness of ORL outside the macula of eyes with RMD is thinner than that of healthy eyes and eyes with early/mid-stage AMD. The thinning of ORL outside the macula is related to the decrease in the blood flow density of the choriocapillaris layer in patients with RMD.

Superatomic Three-Center Bond in a Tri-Icosahedral Au36Ag2(SR)18 Cluster: Analogue of 3c-2e Bond in Molecules

Probing the nature of electronic stability for ligand-protected gold clusters is important in gold chemistry. A thermally stable Au₃₆Ag₂(SR)₁₈ nanocluster was synthesized recently. It has a D_3h tri-icosahedral [Au₃₀Ag₂]¹²⁺ core with 20 valence electrons, which does not follow the magic number of gold superatoms. Herein, we propose a superatomic three-center bond to unveil its electronic stability. The [Au₃₀Ag₂]¹²⁺ core is viewed as a union of three face-fused superatoms, and chemical bonding analysis suggests a three-superatom-center two-electron (3sc-2e) bond for the octet rule of each superatom, which mimics the bonding framework of the D_3h O₃^2- molecule. Moreover, a liganded tri-icosahedral [Au₂₇Pt₃Ag₂]¹¹⁺ core with 18 valence electrons is predicted, and three 2sc-2e bonds are formed between each of two superatoms to satisfy the octet rule (analogue of D_3h O₃), indicating the flexibility of superatomic bonding. Such a superatomic three-center bond extends the community of superatomic bonding and gives a new perspective for superatom assembling.

Sodium Cationization Enables Exotic Deprotonation Sites on Gaseous Mononucleotides

We report observation and photoelectron spectroscopic characterization of sodium cationization on four doubly deprotonated mononucleotide dianions Na⁺·[dNMP-2H]^2- (N = A, G, C, or T) in the gas phase. Multiple tautomers with distinct deprotonated sites are identified, in which Na⁺ enables novel double deprotonation patterns and folds the resultant mononucleotide dianions. The most stable isomer for the whole family is derived from detaching one proton from the phosphate and the other from the nucleobase (amino group for N = A, G, and C, but nitrogen atom for T), whereas high-lying isomers with protons detached separately from the phosphate and the hydroxy group of sugar coexist. Particularly, an exotic deprotomer with both protons deprived from guanosine is populated as well. This work thus displays a remarkably diverse binding landscape enabled by sodium cationization, a potentially critical element in developing a general formulism to better model metal cation and nucleotide interactions.

A unified superatomic-molecule theory for local aromaticity in π-conjugated systems

Aromaticity is one of the most important concepts in chemistry. However, there is still no unified chemical insight for various systems with conjugated sp2 carbon. Herein, we proposed a superatomic-molecule theory to build a generalized electron-rule for polycyclic conjugated hydrocarbons, fullerenes and 2D periodic materials. Taking benzenoid units as 2D superatoms, polycyclic conjugated hydrocarbons and C60 can be seen as superatomic molecules consisting of bonded superatoms, resulting in local aromaticity. In superatomic molecules, π electrons are not totally delocalized, but localized in a single superatom forming superatomic lone pairs or shared by two atoms forming a superatomic bond, mimicking rules in classical valence bond theory. Moreover, two 2D superatomic crystals (C18H6 and C54H18) are predicted to have fairly large band gaps (∼1.8 eV), although the π electrons are conjugated and delocalized. The proposed superatomic-molecule theory provides generalized chemical insights into the nature of local aromaticity, which can be qualitatively evaluated by the chemical intuition given by superatomic Lewis structures.

Assembling Au4 Tetrahedra to 2D and 3D Superatomic Crystals Based on Superatomic-Network Model

Thiolate-protected gold nanoclusters (denoted as Au _m (SR) _n or Au _n L _m ) have received extensive attention both experimentally and theoretically. Understanding the growth mode of the Au₄ unit in Au _m (SR) _n is of great significance for experimental synthesis and the search for new gold clusters. In this work, we first build six clusters of Au₇(AuCl₂)₃, Au₁₂(AuCl₂)₄, Au₁₆(AuCl₂)₆, Au₂₂(AuCl₂)₆, and Au₃₀(AuCl₂)₆ with the Au₄ unit as the basic building blocks. Density functional theory (DFT) calculations show that these newly designed clusters have high structural and electronic stabilities. Based on chemical bonding analysis, the electronic structures of these clusters follow the superatom network (SAN) model. Inspired by the cluster structures, we further predicted an Au₄ two-dimensional (2D) monolayer and a three-dimensional (3D) crystal using graphene and diamond as templates, respectively. The computational results demonstrate that the two structures have high dynamic, thermal, and mechanical stabilities, and both structures exhibit metallic properties according to the band structures calculated at the HSE06 level. The chemical bonding analysis by the solid-state natural density partitioning (SSAdNDP) method indicates that they are superatomic crystals assembled by two electron Au₄ ^- superatoms. With this construction strategy, the new bonding pattern and properties of Au _n L _m are studied and the structure types of gold are enriched.

Theoretical study on L-H+-L with identical donors: short strong hydrogen bond or not?

Short strong hydrogen bonds (SSHBs) play crucial role in many chemical processes. Recently, as the representative of SSHBs, [F-H-F]- was experimentally observed. [F-H-F]- has a symmetric structure, which can be described as a H+ acid shared by two terminal F- donors (F--H+-F-). To explore whether two identical donors are bound to result in SSHBs, we performed theoretical studies on a series of compounds (L-H+-L) with two identical electron donors (L corresponds to donors containing group 14, 15, 16 and 17 elements). The results show that identical donors do not definitely lead to SSHBs. Instead, typical hydrogen bonds also exist. We found that both electronegativity and basicity contribute to the patterns of hydrogen bonds, where more electronegative and weaker donors benefit to SSHBs. Besides, it was found that zero-point energies also respond to the hydrogen bonding systems. This systemic work is expected to provide more insights into SSHBs.

New insight into the electronic structure of SiF4: synergistic back-donation and the eighteen-electron rule

SiF₄ demonstrated high thermal stability in dry air or vacuum, and a Si-F bond length of 1.554 Å is close to the second period element C-C bond length (1.54 Å) of C₂H₆. To determine which factors confer this property of SiF₄, here we conduct a comparative study of a series of molecules SiH_nF_4-n (n = 0, 1, 2, 3), SiX₄ (X = Cl, Br, I), CF₄ and TiF₄ in terms of bond length and energy, molecular orbitals, and adaptive natural density partitioning (AdNDP) analysis. The AdNDP analysis shows that there are five 5c-2c bonds in SiF₄, here named synergistic back-donation (SBD) bonds. These SBD bonds together with the Si-F σ bonds and the eighteen-electron rule are demonstrated as the main factors contributing to the short Si-F bond length and the high thermal stability of SiF₄ in dry air or vacuum. Moreover, the SBD bonds exist widely in other isoelectronic species of SiF₄ such as ClO₄^-, SO₄^2-, PO₄^3- and XeO₄.

P-606 Androgen receptor splice variant lead to PCOS with insulin resistance via IRS1/AKT signaling pathway in mice

Study question

How does the androgen receptor splice variant (ARSV) contribute to insulin resistance in polycystic ovary syndrome (PCOS) patients?

Summary answer

ARSV inhibited the intracellular signaling pathway of insulin, resulting in decreased glucose transporter type 4 (GLUT4) translocation, impaired cellular glucose uptake, and insulin resistance.

What is known already

PCOS is the most common endocrine disorder in women of reproductive age and characterized by hyperandrogenism, ovulation dysfunction, and ovarian polycystic changes. In addition, a significant proportion of PCOS patients will experience insulin resistance. Our previous study identified an ARSV in granulosa cells from PCOS patients, which may be associated with higher insulin levels in follicular fluid.

Study design, size, duration

/

Participants/materials, setting, methods

Glucose metabolism of a mouse model presenting ARSV by CRISPR-Cas9 was measured by glucose tolerance test and insulin tolerance test. Body composition was measured by a nuclear magnetic resonance system. KGN cell lines stably overexpressing wild type androgen receptor (AR group) or ARSV (ARSV group) were successfully constructed by lentivirus infection. The process of glucose uptake by GLUT4, and the expression of target genes in the glucose uptake pathway were detected in cells.

Main results and the role of chance

The mice expressing ARSV had higher body weight and body fat content than the wild type mice, while the muscle content was equivalent.ARSV mice displayed diabetes with impaired glucose tolerance and insulin tolerance at 48 week-age. The levels of fasting glucose and insulin levels were significantly higher in ARSV mice. The basal and insulin-stimulated glucose uptake capacity were also found impaired in ARSV group. Immunofluorescence demonstrated that under insulin stimulation, GLUT4 protein was less expressed in the membrane and more expressed in the cytoplasm in ARSV group. Similar results were obtained by detecting the expression of GLUT4 protein after separating the cell membrane and cytoplasmic proteins. Further detection of the upstream signaling molecules of GLUT4 revealed that the phosphorylation levels of insulin receptor substrate 1 (IRS1) at Ser1101 were slightly increased in ARSV group, after stimulation with insulin and DHT. Besides, the phosphorylation levels of protein kinase B (AKT) were also found significantly decreased at Thr308 and slightly decreased at Ser473 in ARSV group. ARSV inhibited the intracellular signaling pathway of insulin by altering the phosphorylation level of IRS1/AKT signaling, resulting in decreased GLUT4 translocation, impaired cellular glucose uptake, and insulin resistance.

Limitations, reasons for caution

In this study, we failed to obtain clinical samples of PCOS to prospectively verify the association between ARSV and glucose uptake, insulin resistance, and subsequent onset diabetes.

Wider implications of the findings

This transgenic animal model can simulate the reproductive and metabolic phenotypes of PCOS patients, providing a model for future PCOS research. PCOS patients with ARSV should delay the onset of insulin resistance through lifestyle intervention, exercise, and drug therapy as early as possible.

Trial registration number

NA

Properties of Daily Helium Fluxes

We present the precision measurement of 2824 daily helium fluxes in cosmic rays from May 20, 2011 to October 29, 2019 in the rigidity interval from 1.71 to 100 GV based on 7.6×10^{8} helium nuclei collected with the Alpha Magnetic Spectrometer (AMS) aboard the International Space Station. The helium flux and the helium to proton flux ratio exhibit variations on multiple timescales. In nearly all the time intervals from 2014 to 2018, we observed recurrent helium flux variations with a period of 27 days. Shorter periods of 9 days and 13.5 days are observed in 2016. The strength of all three periodicities changes with time and rigidity. In the entire time period, we found that below ∼7  GV the helium flux exhibits larger time variations than the proton flux, and above ∼7  GV the helium to proton flux ratio is time independent. Remarkably, below 2.4 GV a hysteresis between the helium to proton flux ratio and the helium flux was observed at greater than the 7σ level. This shows that at low rigidity the modulation of the helium to proton flux ratio is different before and after the solar maximum in 2014.

FeP2 monolayer: isoelectronic analogue of MoS2 with excellent electronic and optical properties

Two-dimensional semiconductors with suitable indirect band gaps, excellent light absorption capacity, and oxidation resistance are particularly suitable for material applications. Here based on first-principle calculations, we report that the FeP₂ monolayer, which is isoelectronic with MoS₂, has novel electronic properties and an ultra-low diffusion energy barrier of K on the surface, indicating its potential as an anode material of K-ion batteries. The calculated phonon dispersion curves, molecular dynamics, and elastic constants showed that it has high structural stability and oxidation resistance. The monolayer was a semiconductor with an indirect band gap of 0.68 eV. In addition, the FeP₂ monolayer had obvious light absorption in the infrared, visible, and ultraviolet regions, which can be widely used in optoelectronic devices. Bonding analysis showed that there were multicenter bonds inside every hexagonal ring. As the anode material of K-ion batteries, the FeP₂ monolayer had a capacity of 456.84 mA h g^-1, low diffusion energy barrier, and open-circuit voltage. All these characteristics suggest that the FeP₂ monolayer is a potential anode material for K-ion batteries, which needs to be further verified by experiments.

POS0562 AUTOANTIBODIES TO JOINT PROTEINS AS NOVEL BIOMARKERS FOR THE DIAGNOSIS OF UNTREATED EARLY RHEUMATOID ARTHRITIS

Background

Autoantibodies to citrullinated protein (ACPA; measured as anti-CCP; aCCP) and rheumatoid factor (RF) appear years before clinical onset of RA and are essential tools in today’s classification criteria for RA. In animal models, antibodies to joint specific proteins (JP) can induce arthritis, and they are also present at onset of RA [1]. As there is a need for increased precision for early diagnosis of RA as well as identification of different subtypes of the disease, we aim to assess whether autoantibodies to native or modified JP can be used for early and precise diagnosis of RA.

Objectives

To study whether antibodies to JP, alone or in combination with ACPA/RF, could increase the diagnostic sensitivity and specificity in untreated early (ue)RA patients.

Methods

Antibodies to JP were analysed in serum from patients in three independent ueRA cohorts as well as from population controls without rheumatic diseases (WINGA, Gothenburg and MFM-ÅUS, Malmö n=1062). ERAp (n=66), the smallest and most recent cohort was chosen for screening, and BARFOT and TIRA-2 (n=1939) for validation. We have developed a bead-based multianalyte flow immunoassay [2] and screened approx. 350 peptides derived from JPs of interest. We included monoclonal antibodies as assay calibrators and determined limit of detection (LoD). To assess positivity for autoantibodies to JP of interest above LoD, we used 5MAD (median absolute deviation) of the control populations as the cut-off.

Results

In the ERAp cohort, 5 autoantibodies discriminated RA patients from controls with 81% sensitivity and 100% specificity (Table 1). The same autoantibodies had 68% sensitivity and 98% specificity in the combined BARFOT and TIRA-2 cohorts. Together with RF and aCCP, only 2 of the 5 autoantibodies added statistically significant diagnostic value, increasing the sensitivity from 48% to 61% with 99% specificity. In aCCP- and RF-negative ueRA patients (n=536), the novel biomarkers identified 22.5% of the patients with 99% specificity compared to controls.

Table 1.

Diagnostic capacity of the joint-specific antibodies

Test panelPerformanceGroup of patientsaCCP+RF+JP+SensitivitySpecificityAUC(ROC)ERApAll patients (n=66)--X81%100%89%RF and aCCP-neg patients (n=7)1------BARFOT and TIRA-2, combined dataAll patients (N=1939)--X68%98%86%All patients (N=1939)X--58%99%78%All patients (N=1939)2XX-48%100%84%All patients (N=1939)2, 3XXX61%99%86%RF and/or aCCP-pos patients (N=1403)--X84%99%93%RF and aCCP-neg patients (N=536)--X22%99%67%RA, literature valuesAnti-CCP testXN/AN/A53–71%95–96%N/A

1Not analysed due to lack of power

2This patient population is both aCCP+ and RF+

3Only 2 of the 5 autoantibodies added statistically significant to the diagnostic value

AUC, Area under the curve; ROC, receiver operating characteristic curve; N/A, not applicable. Controls without rheumatic diseases: N=935 for BARFOT / TIRA-2 and N=27 for ERAp.

Conclusion

Autoantibodies to JP discriminate ueRA patients better then aCCP and RF alone and add an increased diagnostic value in particular for seronegative patients.

References

[1]Holmdahl, R., V. Malmstrom, and H. Burkhardt, Autoimmune priming, tissue attack and chronic inflammation - the three stages of rheumatoid arthritis. Eur J Immunol, 2014. 44(6): p. 1593-9.

[2]Viljanen, J., et al., Synthesis of an Array of Triple-Helical Peptides from Type II Collagen for Multiplex Analysis of Autoantibodies in Rheumatoid Arthritis. ACS Chem Biol, 2020. 15(9): p. 2605-2615. Correction: ACS Chem Biol, 2020. 15(11): p. 3072

Acknowledgements

BARFOT study group.

Disclosure of Interests

Erik Lönnblom: None declared, Monica Leu Agelii: None declared, Outi Sareila Employee of: Part time employee in Vacara AB, Ingiäld Hafström: None declared, Maria Andersson: None declared, Lei Cheng: None declared, Göran Bergström: None declared, Anna-Karin H Ekwall: None declared, Anna Rudin: None declared, Alf Kastbom: None declared, Christopher Sjowall: None declared, Bingze Xu: None declared, Lennart T.H. Jacobsson: None declared, Johan Viljanen: None declared, Jan Kihlberg: None declared, Inger Gjertsson: None declared, Rikard Holmdahl Shareholder of: Rikard Holmdahl the founder of Vacara AB.

Adsorption properties of pyramidal superatomic molecules based on the structural framework of the Au20 cluster

The pyramidal Au₂₀ cluster is a highly inert and stable superatomic molecule, but it is not suitable as a potential catalyst for covalent bond activations, e.g., CO oxidation reaction. Herein, the adsorption and electronic properties of CO molecules on various pyramidal clusters based on the structural framework of Au₂₀ are investigated using density functional theory. According to the SVB model, we constructed isoelectronic superatomic molecules with different pyramid configurations by replacing the vertex atoms of the Au₂₀ using metal M atoms (M = Li, Be, Ni, Cu, and Zn group atoms). After the CO molecules are adsorbed on the vertex atoms of these metal clusters, we analyzed the CO adsorption energies, C-O bond stretching frequencies, and electronic properties of the adsorption structures. It was found that the adsorption of CO molecules results in minimal changes in the parent geometries of the pyramidal clusters, and most adsorption structures are consistent with the geometry of CO adsorption at the vertex site of the Au₂₀ cluster. There are significant red shifts when CO molecules are adsorbed on the Ni/Pd/Pt atoms of the clusters, and their CO adsorption energies were also greater. The molecular orbitals and density of states reveal that there are overlaps between the frontier orbitals of the clusters and CO, and the electronic structure of NiAu₁₉^- is not sensitive to CO. The ETS-NOCV analysis shows that the increase in the density of the bonding area caused by the orbital interactions between the fragments is higher than the decrease in the density of the bonding area caused by Pauli repulsion, presenting that the direction of charge flow in the deformation density is from CO → clusters. From energy decomposition analysis (EDA) and NPA charge, we find a predominant covalent nature of the contributions in CO⋯M interactions (σ-donation). Our study indicates that the SVB model provides a new direction to expand the superatomic catalysts from the superatom clusters, which also provides inference for the extension of the single atom catalysis.

Exoergic pathways triggered by O/H radicals in different metallic carbohydrazide perchlorates (M2+ = Mn2+, Fe2+, Co2+, Ni2+, Zn2+ and Cd2+)

Metallic carbohydrazide perchlorates (M[(N₂H₃)₂C = O](ClO₄)₂, M²⁺ = Mn²⁺, Fe²⁺, Co²⁺, Ni²⁺, Zn²⁺ and Cd²⁺, simplified as MCPs) are a series of energetic primary explosives, among which ZnCP and CdCP are already applied in civilian/military fields. The six MCPs possess similar structures but demonstrate different energetic performances in their decomposition, which are obviously determined by their different central metals. Here, we apply DFT and Car-Parrinello molecular dynamics (CPMD) to understand the electronic structures and decomposition pathways of the MCPs. Based on the results, the crystal MCPs with larger electronic band gaps show lower impact sensitivity. However, the friction sensitivity of MCPs is dominated by the strength of their intermolecular O⋯H interactions. In the CPMD simulations, we obtained a different conclusion from the traditional viewpoint, where the decomposition is spontaneous from the cleavage of M-N bonds. Indeed, there are two stages in the decomposition of the MCPs, based on our calculations: (I) nonspontaneous 3-step departure of the CHZ groups and (II) spontaneous exoergic decomposition pathways of the CHZ groups triggered by the transfer of O/H radicals. Our study provides a systematic study of the MCP family, which also affords a new route for understanding the relationship between the energetic properties and electronic structures of energetic metal complexes.

Enhancement of the Thermoelectric Performance of Cu2GeSe3 via Isoelectronic (Ag, S)-co-substitution

Recently, ternary Cu-based Cu-IV-Se (IV = Sb, Ge, and Sn) compounds have received extensive attention in the thermoelectric field. Compared with Cu-Sb-Se and Cu-Sn-Se, Cu-Ge-Se compounds have been less studied due to its poor Seebeck coefficient and high thermal conductivity. Here, the Cu₂GeSe₃ material with high electrical conductivity was first prepared, and then, its effective mass was increased by doping with S, which led to the Seebeck coefficient of the doped sample being 1.93 times higher than that of pristine Cu₂GeSe₃ at room temperature. Moreover, alloying Ag at the Cu site in the Cu₂GeSe_2.96S_0.04 sample could further cause a 5.16 times increase in the Seebeck coefficient at room temperature, and the lattice thermal conductivity was remarkably decreased because of the introduction of the dislocations in the Cu₂GeSe₃ sample. Finally, benefitted from the high Seebeck coefficient and low thermal conductivity, a record high ZT = 0.9 at 723 K was obtained for the Cu_1.85Ag_0.15GeSe_2.96S_0.04 sample, which increased 345% in comparison with the pristine Cu₂GeSe₃, and it is among the highest reported values for Cu₂GeSe₃-based thermoelectric.