Catalysts with Trimetallic Sites on Graphene-like C2N for Electrocatalytic Nitrogen Reduction Reaction: A Theoretical Investigation.

Electrocatalytic nitrogen reduction reaction (NRR) is a green and highly efficient way to replace the industrial Haber-Bosch process. Herein, clusters consisting of three transition metal atoms loaded on C2N as NRR electrocatalysts are investigated using density functional theory (DFT). Meanwhile, Ca was introduced as a promoter and the role of Ca in NRR was investigated. It was found that Ca anchored to the catalyst can act as an electron donor and effectively promote the activation of N2 on M3. In both M3@C2N and M3Ca@C2N (M = Fe, Co, Ni), the limiting potential (UL) is less negative than that of the Ru(0001) surface and has the ability to suppress the competitive hydrogen evolution reaction (HER). Among them, Fe3@C2N is suggested to be the most promising candidate for NRR with high thermal stability, strong N2 adsorption ability, low limiting potential, and good NRR selectivity. The concepts of trimetallic sites and alkaline earth metal promoters in this work provide theoretical guidance for the rational design of atomically active sites in electrocatalytic NRR.

Clinical responses to vemurafenib in postoperative recurrence of papillary thyroid carcinoma with esophageal fistula: A case report.

BACKGROUND: While papillary thyroid carcinoma (PTC) generally exhibits a favorable prognosis post-surgery, the poorly differentiated subtype presents elevated rates of postoperative recurrence. Certain aggressive cases demonstrate invasive behavior, compromising adjacent structures and leading to a poor prognosis. This study delineates a unique case of postoperative PTC recurrence, complicated by esophageal fistula, that showed favorable outcomes following brief Vemurafenib treatment. PATIENT DESCRIPTION: A 64-year-old female patient underwent surgical resection for PTC, subsequently experiencing rapid tumor recurrence and development of an esophageal fistula. DIAGNOSIS: The patient was confirmed to have locally advanced PTC through intraoperative cytopathology. The cancer recurred postoperatively, culminating in the formation of an esophageal fistula. METHODS: The patient was administered Vemurafenib at a dosage of 960 mg twice daily following tumor recurrence. RESULTS: A 12-month regimen of targeted Vemurafenib therapy led to a substantial reduction in tumor size. Concurrently, the esophageal fistula underwent complete healing, facilitating successful removal of the gastrostomy tube. The tumor response was classified as stable disease. CONCLUSION SUBSECTIONS: Vemurafenib demonstrates potential as a targeted therapeutic strategy for recurrent PTC harboring the BRAFV600E mutation. This approach may effectively mitigate tumor dimensions and the associated risk of esophageal and tracheal fistulas.

Exploring the stability and aromaticity of rare earth doped tin cluster MSn16- (M = Sc, Y, La).

Rare earth elements have high chemical reactivity, and doping them into semiconductor clusters can induce novel physicochemical properties. The study of the physicochemical mechanisms of interactions between rare earth and tin atoms will enhance our understanding of rare earth functional materials from a microscopic perspective. Hence, the structure, electronic characteristics, stability, and aromaticity of endohedral cages MSn16- (M = Sc, Y, La) have been investigated using a combination of the hybrid PBE0 functional, stochastic kicking, and artificial bee colony global search technology. By comparing the simulated results with experimental photoelectron spectra, it is determined that the most stable structure of these clusters is the Frank-Kasper polyhedron. The doping of atoms has a minimal influence on density of states of the pure tin system, except for causing a widening of the energy gap. Various methods such as ab initio molecular dynamics simulations, the spherical jellium model, adaptive natural density partitioning, localized orbital locator, and electron density difference are employed to analyze the stability of these clusters. The aromaticity of the clusters is examined using iso-chemical shielding surfaces and the gauge-including magnetically induced currents. This study demonstrates that the stability and aromaticity of a tin cage can be systematically adjusted through doping.

Application of whole-genome tiling array at Shanghai port, China: An alternative method for SARS-CoV-2 surveillance.

The ongoing coronavirus disease 2019 (COVID-19) pandemic, driven by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), highlights the critical role of genomic surveillance in tracking rapidly spreading viruses and their evolving lineages. The emergence of the SARS-CoV-2 tiling array, a comprehensive tool capable of capturing the entire viral genome, has presented a promising avenue for variants. This study introduces the SARS-CoV-2 tiling array as a novel method for port inspection. Using next-generation sequencing as a benchmark, 35 positive samples underwent sequencing through both methodologies, including the Alpha variant (B.1.1.7), Delta variants (AY.120, AY.122, AY.23.1), and Omicron variants (BA.1, BA.2, BA.2.75, BA.4, BA.5, BE.1, BF.7, BN.1, BQ.1, XBB.1) within the sample set. The whole-genome tiling array demonstrated successful identification of various sublineages of SARS-CoV-2. The average sequencing coverage rates were 99.22% (96.82%-99.92%) for the whole-genome tiling array and 98.56% (92.81%-99.59%) for Illumina sequencing, respectively. The match rates of these two methods ranged from 92.81%-99.59%, with an average rate of 98.56%. Among the benefits of the whole-genome tiling array are its cost-effectiveness and equipment simplification, making it particularly suitable for identifying SARS-CoV-2 variants in the front-line inspection department. The aforementioned findings provide valuable insights into the surveillance of COVID-19 and present a pragmatic solution for improving quarantine measures at entry points.

A full genome tiling array enhanced the inspection and quarantine of SARS-CoV-2.

As the worldwide spreading epidemic of SARS-CoV-2, quick inspection and quarantine of passengers for SARS-CoV-2 infection are essential for controlling the spread of SARS-CoV-2, especially the cross-border transmission. This study reports a SARS-CoV-2 genome sequencing method based on a re-sequencing tiling array successfully used in border inspection and quarantine. The tiling array chip has four cores, with one core of 240,000 probes dedicated to the whole genome sequencing of the SAR-CoV-2 genome. The assay protocol has been improved to reduce the detection time to within one day and can detect 96 samples in parallel. The detection accuracy has been validated. This fast and simple procedure is also of low cost and high accuracy, and it is particularly suitable for the rapid tracking of viral genetic variants in custom inspection applications. Combining these properties means this method has significant application potential in the clinical investigation and quarantine of SARS-CoV-2. We used this SARS-CoV-2 genome re-sequencing tiling array to inspect and quarantine China's entry and exit ports in the Zhejiang Province. From November 2020 to January 2022, we observed the gradual shift of SARS-CoV-2 variants from the D614G type to the Delta Variant, and then to the dominance of the Omicron variant recently, consistently with the global emergency pattern of the new SARS-CoV-2 variant.

SARS-CoV-2 variant identification using a genome tiling array and genotyping probes.

With over 5.5 million deaths worldwide attributed to the respiratory disease COVID-19 caused by the novel coronavirus SARS-CoV-2, it is essential that continued efforts be made to track the evolution and spread of the virus globally. The authors previously presented a rapid and cost-effective method to sequence the entire SARS-CoV-2 genome with 95% coverage and 99.9% accuracy. This method is advantageous for identifying and tracking variants in the SARS-CoV-2 genome compared with traditional short-read sequencing methods which can be time-consuming and costly. Herein, the addition of genotyping probes to a DNA chip that targets known SARS-CoV-2 variants is presented. The incorporation of genotyping probe sets along with the advent of a moving average filter improved the sequencing coverage and accuracy of the SARS-CoV-2 genome.

Throughout the COVID-19 pandemic the virus known as SARS-CoV-2 has continued to mutate and evolve. It is imperative to continue to track these mutations and where the virus has traveled to best inform healthcare practices and global strategies to combat the virus. The authors previously developed a method to investigate 95% of this viral genome with 99.9% accuracy that was more cost-effective and less time-consuming than previous methods. In this work, specific markers were added to the technology to allow tracking of mutations in the virus that have already been documented. In doing so, the accuracy and how much of the viral genome can be sequenced was improved.

Heteronuclear Trimetallic MFe2 and M2 Fe (M=V, Nb, and Ta) Clusters for Dinitrogen Activation.

Catalysts with heteronuclear metal active sites may have high performance in the nitrogen reduction reaction (NRR), and the in-depth understanding of the reaction mechanisms is crucial for the design of related catalysts. In this work, the dissociative adsorption of N2 on heteronuclear trimetallic MFe2 and M2 Fe (M=V, Nb, and Ta) clusters was studied with density functional theory calculations. For each cluster, two reaction paths were studied with N2 initially on M and Fe atoms, respectively. Mayer bond order analysis provides more information on the activation of N-N bonds. M2 Fe is generally more reactive than MFe2 . The coordination mode of N2 on three metal atoms can be end-on: end-on: side-on (EES) for both MFe2 and M2 Fe. In addition, a unique end-on: side-on: side-on (ESS) coordination mode was found for M2 Fe, which leads to a higher degree of N-N bond activation. Nb2 Fe has the highest reactivity towards N2 when both the transfer of N2 and the dissociation of N-N bonds are taken into account, while Ta-containing clusters have a superior ability to activate the N-N bond. These results indicate that it is possible to improve the performance of iron-based catalysts by doping with vanadium group metals.

Trimetallic clusters in the sumanene bowl for dinitrogen activation.

It is of great importance to find catalysts for the nitrogen reduction reaction (NRR) with high stability and reactivity. A series of M3 clusters (M = Ti, Zr, V, and Nb) supported on sumanene (C21H12) were designed as potential catalysts for the NRR by taking advantage of the high reactivity of trimetallic clusters and the unique geometric and electronic properties of sumanene, a bowl-like organic molecule. Detailed mechanisms of NN bond cleavage on C21H12-M3 were investigated by DFT calculations and compared with those on bare M3 clusters. M3 in the sumanene bowl is very stable with large binding energies, which prohibits the cohesion of M3 into M6. In the bowl, M3 has a (quasi-) equilateral triangle structure with lengthened M-M bonds, which is particularly beneficial to the N2 transfer process on Ti3 and V3 clusters. The N-N bond can be dissociated by both M3 and C21H12-M3 clusters without the overall energy barriers. A blurring effect is found in which some geometric and electronic properties of different metal types become similar when M3 is supported on the substrate. Our work demonstrates that sumanene is a suitable substrate to support M3 in the activation of N2 with enhanced stability and maintained a high level of reactivity compared to bare M3.

Comparison of Nitrogen Activation on Trinuclear Niobium and Tungsten Sulfide Clusters Nb3 Sn and W3 Sn (n=0-3): A DFT Study.

The front cover artwork is provided by Prof. Xun-Lei Ding's group at North China Electric Power University (NCEPU). The image shows the cleavage of the triple bond of a dinitrogen molecule on trinuclear metal clusters with sulfide ligands, which is the critical step in nitrogen reduction reactions (NRR). Read the full text of the Research Article at 10.1002/cphc.202200124.

Comparison of Nitrogen Activation on Trinuclear Niobium and Tungsten Sulfide Clusters Nb3 Sn and W3 Sn (n=0-3): A DFT Study.

The reaction of N2 with trinuclear niobium and tungsten sulfide clusters Nb3 Sn and W3 Sn (n=0-3) was systematically studied by density functional theory calculations with TPSS functional and Def2-TZVP basis sets. Dissociations of N-N bonds on these clusters are all thermodynamically allowed but with different reactivity in kinetics. The reactivity of Nb3 Sn is generally higher than that of W3 Sn . In the favorite reaction pathways, the adsorbed N2 changes the adsorption sites from one metal atom to the bridge site of two metal atoms, then on the hollow site of three metal atoms, and at that place, the N-N bond dissociates. As the number of ligand S atoms increases, the reactivity of Nb3 Sn decreases because of the hindering effect of S atoms, while W3 S and W3 S2 have the highest reactivity among four W3 Sn clusters. The Mayer bond order, bond length, vibrational frequency, and electronic charges of the adsorbed N2 are analyzed along the reaction pathways to show the activation process of the N-N bond in reactions. The charge transfer from the clusters to the N2 antibonding orbitals plays an essential role in N-N bond activation, which is more significant in Nb3 Sn than in W3 Sn , leading to the higher reactivity of Nb3 Sn . The reaction mechanisms found in this work may provide important theoretical guidance for the further rational design of related catalytic systems for nitrogen reduction reactions (NRR).

Facile N≡N Bond Cleavage by Anionic Trimetallic Clusters V3-x Tax C4- (x=0-3): A DFT Study.

Activation of N2 on anionic trimetallic V3-x Tax C4- (x=0-3) clusters was theoretically studied employing density functional theory. For all studied clusters, initial adsorption of N2 (end-on) on one of the metal atoms (denoted as Site 1) is transferred to an of end-on: side-on: side-on coordination on three metal atoms, prior to N2 dissociation. The whole reaction is exothermic and has no global energy barriers, indicating that the dissociation of N2 is facile under mild conditions. The reaction process can be divided into two processes: N2 transfer (TRF) and N-N dissociation (DIS). For V-series clusters, which has a V atom on Site 1, the rate-determining step is DIS, while for Ta-series clusters with a Ta on Site 1, TRF may be the rate-determining step or has energy barriers similar to those of DIS. The overall energy barriers for heteronuclear V2 TaC4- and VTa2 C4- clusters are lower than those for homonuclear V3 C4- and Ta3 C4- , showing that the doping effect is beneficial for the activation and dissociation of N2 . In particular, V-Ta2 C4- has low energy barriers in both TRF and DIS, and it has the highest N2 adsorption energy and a high reaction heat release. Therefore, a trimetallic heteronuclear V-series cluster, V-Ta2 C4- , is suggested to have high reactivity to N2 activation, and may serve as a prototype for designing related catalysts at a molecular level.

Emergency Transcatheter Arterial Embolization for Acute Mediastinal Hemorrhage.

PURPOSE: The aim of this study was to investigate the application value of transcatheter arterial embolization (TAE) for mediastinal hemorrhage. MATERIALS AND METHODS: The study retrospectively analyzed the status of TAE treatment in 13 patients with mediastinal hemorrhage. RESULTS: Aortic angiography and bleeding artery angiography showed that the bleeding in 13 mediastinal hemorrhage patients, respectively, originated from intercostal artery, esophageal artery, or bronchial artery. All patients were embolized with gelatin sponge and (or) polyvinyl alcohol particles. Chest computed tomography scan found that all 13 patients showed reduced range of mediastinal hematoma after TAE. CONCLUSION: TAE has the advantages of reduced trauma, rapid and direct hemostasis, and solid therapeutic effects in the treatment of mediastinal hemorrhage.

PDPOB Exerts Multiaspect Anti-Ischemic Effects Associated with the Regulation of PI3K/AKT and MAPK Signaling Pathways.

The discovery of new therapeutic agents for ischemic stroke remains an urgent need. Here, we identified a novel phenyl carboxylic acid derivative, n-pentyl 4-(3,4-dihydroxyphenyl)-4-oxobutanoate (PDPOB), with anti-ischemic activities. The in vitro anti-ischemic neuroprotective and anti-inflammatory capacities of PDPOB were investigated using neuronal cells suffering from oxygen-glucose deprivation/reperfusion (OGD/R) and microglial cells stimulated by lipopolysaccharide (LPS). PDPOB attenuated the OGD/R-evoked cellular damage of SH-SY5Y cells and primary cortical neurons in a concentration-dependent manner. Likewise, PDPOB displayed protective roles against OGD/R-evoked multiaspect neuronal deterioration in SH-SY5Y cells, as evidenced by alleviated mitochondrial dysfunction, oxidative stress, and apoptosis. A further study unveiled the accelerated phosphorylation of protein kinase B (AKT) by PDPOB treatment, while blockade of phosphoinositide 3-kinase (PI3K)/AKT signaling substantially diminished the neuroprotective capacities of PDPOB. Additionally, the PDPOB pretreatment dampened the LPS-evoked neuroinflammation in BV2 cells, characterized by the suppressed secretion of nitric oxide (NO) and proinflammatory cytokines, as well as normalized expression of nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Western blotting further revealed that PDPOB abated the overabundant phosphorylation of the extracellular signal-regulated kinase (ERK), c-Jun-N-terminal kinase (JNK), and p38 in LPS-exposed BV2 cells. The intravenous application of PDPOB (30 mg/kg, single dose) attenuated ipsilateral cerebral infarction in middle cerebral artery occlusion (MCAO) rats, accompanied by recovered neurological behaviors. Collectively, the above observations provided substantial evidence for the favorable properties and mechanistic explanations of PDPOB in the regulation of ischemia-associated neuronal injury and microglial inflammation, which may furnish ideas for the discovery of new therapeutic strategies against cerebral ischemia.

Effects of different breathing techniques on the IVIM-derived quantitative parameters of the normal pancreas.

PURPOSE: To prospectively compare the differences in intravoxel incoherent motion (IVIM)-derived quantitative parameters in different anatomic locations of the normal pancreas with different breathing techniques in a healthy population. METHOD: Twenty-six volunteers successfully underwent pancreas axial IVIM imaging with a 3.0-T MR system using 11 b-values (from 0 to 1000 sec/mm2) with three different breathing techniques: free breath (FB), liver dome scout (LDS), and phase scout (PS). The IVIM-derived quantitative parameters in three anatomic locations (head, body, and tail of the pancreas) were calculated. The intra-, inter-, and short-term consistency of IVIM-derived quantitative parameters were assessed by comparing 95% confidence interval (CI) of limits of agreement (LOA) of difference between measurements and clinical maximum allowed difference using the Bland-Altman method. The Kruskal-Wallis test was used to compare pancreatic IVIM-derived parameters. RESULTS: In Bland-Altman graph, the maximum values of the 95% CIs of LOAs of Dslow, Dfast, and f were (0.123 ± 0.022) × 10-3 mm2/sec, (22.093 ± 4.997) × 10-3 mm2/sec, and (3.942 ± 0.621)%, and the consistency of Dslow and f was good and that of Dfast was poor overall. The Dslow, Dfast, and f values of normal pancreas were (1.056 ± 0.121) × 10-3 mm2/sec, (55.755 ± 13.011) × 10-3 mm2/sec, and (26.036 ± 2.361)%, respectively, and there aren't any breathing technique (P > 0.05) or location (P > 0.05) dependent differences. CONCLUSIONS: Our study shows that IVIM-derived quantitative parameters of the pancreas may not be affected by breathing techniques and anatomic locations. The f and Dslow values have good repeated measurement consistency under different breathing techniques.

Detecting SARS-CoV-2 and its variant strains with a full genome tiling array.

Coronavirus disease 2019 pandemic is the most damaging pandemic in recent human history. Rapid detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and variant strains is paramount for recovery from this pandemic. Conventional SARS-CoV-2 tests interrogate only limited regions of the whole SARS-CoV-2 genome, which are subjected to low specificity and miss the opportunity of detecting variant strains. In this work, we developed the first SARS-CoV-2 tiling array that captures the entire SARS-CoV-2 genome at single nucleotide resolution and offers the opportunity to detect point mutations. A thorough bioinformatics protocol of two base calling methods has been developed to accompany this array. To demonstrate the effectiveness of the tiling array, we genotyped all genomic positions of eight SARS-CoV-2 samples. Using high-throughput sequencing as the benchmark, we show that the tiling array had a genome-wide accuracy of at least 99.5%. From the tiling array analysis results, we identified the D614G mutation in the spike protein in four of the eight samples, suggesting the widespread distribution of this variant at the early stage of the outbreak in the United States. Two additional nonsynonymous mutations were identified in one sample in the nucleocapsid protein (P13L and S197L), which may complicate future vaccine development. With around $5 per array, supreme accuracy, and an ultrafast bioinformatics protocol, the SARS-CoV-2 tiling array makes an invaluable toolkit for combating current and future pandemics. Our SARS-CoV-2 tilting array is currently utilized by Molecular Vision, a CLIA-certified lab for SARS-CoV-2 diagnosis.

SARS-CoV-2 Variant Identification Using a Genome Tiling Array and Genotyping Probes.

With over three million deaths worldwide attributed to the respiratory disease COVID-19 caused by the novel coronavirus SARS-CoV-2, it is essential that continued efforts be made to track the evolution and spread of the virus globally. We previously presented a rapid and cost-effective method to sequence the entire SARS-CoV-2 genome with 95% coverage and 99.9% accuracy. This method is advantageous for identifying and tracking variants in the SARS-CoV-2 genome when compared to traditional short read sequencing methods which can be time consuming and costly. Herein we present the addition of genotyping probes to our DNA chip which target known SARS-CoV-2 variants. The incorporation of the genotyping probe sets along with the advent of a moving average filter have improved our sequencing coverage and accuracy of the SARS-CoV-2 genome.

Non-Dissociative Activation of Chemisorbed Dinitrogen on One or Two Vanadium Atoms Supported by a Mo6 S8 Cluster.

Adsorption of N2 on Mo6 S8 q _Vx clusters (x=0, 1, 2; q=0, ±1) were systematically studied by density functional theory calculations with dispersion corrections. It was found that the N2 can be chemisorbed and undergo non-dissociative activation on single or double metal atoms. The adsorption and activation are influenced by metal types (V or Mo), N2 coordination modes and charge states of the clusters. Particularly, anionic Mo6 S8 - _V2 clusters have remarkable ability to fix and activate N2 . In Mo6 S8 - _V2 , two V atoms prefer to adsorb on two adjacent S-Mo-S hollow sites, leading to the formation of a supported V…V unit. The N2 is bridged side-on coordinated with these two V atoms with high adsorption energy and significant charge transfer. The bond order, bond length and vibration frequency of the adsorbed N2 are close to those of a N-N single bond.

Highly Accurate Chip-Based Resequencing of SARS-CoV-2 Clinical Samples.

SARS-CoV-2 has infected over 128 million people worldwide, and until a vaccine is developed and widely disseminated, vigilant testing and contact tracing are the most effective ways to slow the spread of COVID-19. Typical clinical testing only confirms the presence or absence of the virus, but rather, a simple and rapid testing procedure that sequences the entire genome would be impactful and allow for tracing the spread of the virus and variants, as well as the appearance of new variants. However, traditional short read sequencing methods are time consuming and expensive. Herein, we describe a tiled genome array that we developed for rapid and inexpensive full viral genome resequencing, and we have applied our SARS-CoV-2-specific genome tiling array to rapidly and accurately resequence the viral genome from eight clinical samples. We have resequenced eight samples acquired from patients in Wyoming that tested positive for SARS-CoV-2. We were ultimately able to sequence over 95% of the genome of each sample with greater than 99.9% average accuracy.

Ximaoglaucumins A - F, new cembranoids with anti-inflammatory activities from the South China Sea soft coral Sarcophyton glaucum.

Six new cembrane-type diterpenoids, namely ximaoglaucumins A-F (1-6), along with fifteen known related ones (7-10 and 14-24), have been isolated from the soft coral Sarcophyton glaucum collected off the Ximao Island in the South China Sea. Their structures, including absolute stereochemistry, were elucidated by extensive spectroscopic analysis, quantum mechanical nuclear magnetic resonance (QM-NMR) methods, X-ray diffraction analysis, chemical methods, as well as comparison with the reported data in the literature. Further, detailed analysis of spectroscopic data of 7 not only clarified the confusions regarding 7, 11 (sarcophytolol) and 12/13 (sarcotrocheliol) in the literature, but also led to revise the structure of 11, which was mis-assigned due to careless/erroneous interpretation of the 2D NMR spectra, and to correct the structures of 12/13, which were both wrongly depicted. In in vitro bioassay, compounds 8 and 20 exhibited potent inhibitory effects on lipopolysaccharide (LPS)-induced inflammatory responses in BV-2 microglial cells.

Diterpenoids from the seeds of Euphorbia lathyris and their effects on microglial nitric oxide production.

Four new lathyrane-type diterpenoids (1-4) and a novel macrocyclic diterpenoid (5) featuring a 5/7/7/4-fused ring system, together with seventeen known ones (6-22), were isolated from the seeds of Euphorbia lathyris. Their structures were elucidated by extensive spectroscopic analyses and single crystal X-ray crystallography. These isolates were evaluated for their inhibition against nitric oxide (NO) production induced by lipopolysaccharide (LPS) in BV-2 microglial cells. As a result, the inhibitory rates of compounds 1, 3, 4, 6, 7, 9-11, 13-15, 20, and 21 on NO production were more than 40% with the cell viability more than 80% at their effective concentrations. In addition, compounds 6 and 11 markedly reduced the mRNA levels of pro-inflammatory cytokines IL-6 and IL-1ß in LPS-stimulated BV-2 cells.