Facilitating the Electrochemical Oxidation of ZnS through Iodide Catalysis for Aqueous Zinc-Sulfur Batteries.

Aqueous zinc-sulfur (Zn-S) batteries show great potential for unlocking high energy and safety aqueous batteries. Yet, the sluggish kinetic and poor redox reversibility of the sulfur conversion reaction in aqueous solution challenge the development of Zn-S batteries. Here, we fabricate a high-performance Zn-S battery using highly water-soluble ZnI2 as an effective catalyst. In situ experimental characterizations and theoretical calculations reveal that the strong interaction between I- and the ZnS nanoparticles (discharge product) leads to the atomic rearrangement of ZnS, weakening the Zn-S bonding, and thus facilitating the electrochemical oxidation reaction of ZnS to S. The aqueous Zn-S battery exhibited a high energy density of 742 Wh kg(sulfur) -1 at the power density of 210.8 W kg(sulfur) -1 and good cycling stability over 550 cycles. Our findings provide new insights about the iodide catalytic effect for cathode conversion reaction in Zn-S batteries, which is conducive to promoting the future development of high-performance aqueous batteries.

Prospective randomized comparison between upgraded '2C3L' vs. PVI approach for catheter ablation of persistent atrial fibrillation: PROMPT-AF trial design.

BACKGROUND: In randomized studies, the strategy of pulmonary vein antral isolation (PVI) plus linear ablation has failed to increase success rates for persistent atrial fibrillation (PeAF) ablation when compared with PVI alone. Peri-mitral reentry related atrial tachycardia due to incomplete linear block is an important cause of clinical failures of a first ablation procedure. Ethanol infusion (EI) into the vein of Marshall (EI-VOM) has been demonstrated to facilitate a durable mitral isthmus linear lesion. OBJECTIVE: This trial is designed to compare arrhythmia-free survival between PVI and an ablation strategy termed upgraded '2C3L' for the ablation of PeAF. STUDY DESIGN: The PROMPT-AF study (clinicaltrials.gov 04497376) is a prospective, multicenter, open-label, randomized trial using a 1:1 parallel-control approach. Patients (n = 498) undergoing their first catheter ablation of PeAF will be randomized to either the upgraded '2C3L' arm or PVI arm in a 1:1 fashion. The upgraded '2C3L' technique is a fixed ablation approach consisting of EI-VOM, bilateral circumferential PVI, and 3 linear ablation lesion sets across the mitral isthmus, left atrial roof, and cavotricuspid isthmus. The follow-up duration is 12 months. The primary end point is freedom from atrial arrhythmias of >30 seconds, without antiarrhythmic drugs, in 12 months after the index ablation procedure (excluding a blanking period of 3 months). CONCLUSIONS: The PROMPT-AF study will evaluate the efficacy of the fixed '2C3L' approach in conjunction with EI-VOM, compared with PVI alone, in patients with PeAF undergoing de novo ablation.

Vein of Marshall ethanol infusion: First-step or adjunctive choice for perimitral atrial tachycardia?

BACKGROUND: Perimitral atrial tachycardia (PMAT) is the most frequent type of iatrogenic atrial tachycardia (AT) after atrial fibrillation (AF) ablation. Vein of Marshall ethanol infusion (EIVOM) is a promising technique in mitral isthmus (MI) ablation. METHODS: A total of 165 patients with PMAT were divided into three groups according to ablation strategies, including RF only group (n = 89), RF-EIVOM group (initial RF ablation with adjunctive EIVOM, n = 28), and EIVOM-RF group (first-step EIVOM with touch-up RF ablation, n = 48). Acute and follow-up procedure outcomes were evaluated. RESULTS: PMAT terminated in 89.9%, 89.3%, and 93.7% of patients in RF only, RF-EIVOM and EIVOM-RF groups, respectively (p = .715), with complete MI block achieved in 80.9%, 89.3%, and 95.8% of patients (EIVOM-RF vs. RF only, p = .012). First-step utilization of EIVOM was associated with a significant shortening of RF ablation time at MI (EIVOM-RF 2.1 ± 1.3 min, RF only 7.9 ± 5.9 min, RF-EIVOM 6.8 ± 5.8 min; p < .001) and a decrease in the proportion of patients need ablation within coronary sinus (CS, EIVOM-RF 14.6%, RF only 61.8%, RF-EIVOM 64.3%; p < .001). After a mean follow-up of 12.1 ± 6.2 months, AF/AT recurred in 39 (43.8%), 6 (21.4%), and 12 (25.0%) patients in RF only, RF-EIVOM, and EIVOM-RF group (RF-EIVOM vs. RF only, p = .026; EIVOM-RF vs. RF only, p = .022). CONCLUSIONS: EIVOM was associated with an enhanced acute MI block rate as well as reduced AF/AT recurrence. First-step utilization of EIVOM promises to significantly simplify the RF ablation process. CONDENSED ABSTRACT: PMAT is the most common type of iatrogenic AT after AF ablation procedures. EIVOM contributed to a higher acute MI block rate and lower arrhythmia recurrence risk during follow-up. First-step utilization of EIVOM significantly reduced the need for radiofrequency ablation at MI and inside CS with the advantage of creating a homogenous, transmural lesion and eliminating epicardial connections.

Measurement of Serum Ultra-Sensitive Thyroid-Stimulating Hormone Levels to Determine the Risk for Recurrence of Atrial Fibrillation Following Catheter Ablation in 575 Patients from a Single Center.

BACKGROUND Thyroid dysfunction has been proved to contribute to the occurrence of atrial fibrillation (AF), leading to the development of AF in animal models and clinical populations. This single-center study investigated the relationship between ultra-sensitive thyroid-stimulating hormone (uTSH) levels and the recurrence of atrial fibrillation (AF) in 575 hospitalized patients who had undergone catheter ablation. MATERIAL AND METHODS The study enrolled 575 hospitalized patients with AF who needed catheter ablation, 105 were non-first catheter ablation patients, and 470 were first catheter ablation (CA) patients. Before ablation, fasting biochemical indexes, including uTSH, were detected. Patients were classified according to uTSH quartile. The presence of AF was confirmed by 12-lead electrocardiogram or 24-h ambulatory electrocardiogram. RESULTS A total of 105 (18.44%) patients had undergone catheter ablation of AF twice or more. Univariate logistic regression analysis showed no significant relationship between uTSH and AF recurrence (HR, 1.047; 95% CI 0.986-1.111; P=1.127). Multivariate logistic regression analysis indicated that compared with low quartiles (Q1 OR, 0.71, 95% CI: 0.35-1.46; P=0.36; Q2 OR 0.71, 95% CI 0.36-1.39; P=0.31;Q3 OR 0.22, 95% CI 0.09-0.53; P=0.001), high quartiles of uTSH had a higher risk of AF recurrence. After adjusting for sex, the risk of AF recurrence in the high quartile uTSH was higher in males than in the low quartile (Q1 OR, 0.60, 95% CI: 0.29-1.26; P=0.18;Q2 OR, 0.52, 95% CI, 0.24-1.13; P=0.09;Q3 OR, 0.42, 95% CI, 0.18-0.94; P=0.03), but not in women. CONCLUSIONS Serum TSH levels in male patients treated for AF with cardiac ablation were significantly associated with AF recurrence.

Association Between Pre-Radiofrequency Catheter Ablation Serum Lipid Levels and Recurrence of Atrial Fibrillation in 412 Patients in Beijing, China: A Single-Center Study.

BACKGROUND This study from a single center in Beijing, China, included 412 patients with atrial fibrillation (AF) who underwent radiofrequency catheter ablation. We aimed to determine whether pre-ablation serum lipid levels were related to recurrence of atrial fibrillation (RAF). MATERIAL AND METHODS A total of 412 patients with AF who underwent radiofrequency catheter ablation were enrolled in the study. Fasting levels of triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and total cholesterol (TC), were measured at baseline before ablation, and patients were classified according to lipid level quartiles (Q1-Q4). RAF was affirmed via 24-h electrocardiography or 12-lead electrocardiography. RESULTS A total of 82 (19.90%) patients experienced RAF. After adjusting for other relevant factors and sex, univariate logistic regression analysis revealed LDL-C (hazard ratio [HR], 1.17; 95% confidence interval [CI], 0.93-1.47) and TC (HR, 1.17; 95% CI, 0.96-1.42) levels were not significantly related to RAF. Multivariate logistic regression analysis revealed that, compared with the highest quartile (Q4), female patients with lower quartiles of TC had higher RAF, especially Q3 (HR, 16.24; 95% CI, 1.14-231.56). LDL-C levels were higher in Q1 than in Q4 but lower in Q2 and Q3 than in Q4 (Q1: HR, 1.34; 95% CI, 0.08-18.89; Q2: HR, 0.09, 95% CI, 0.06-1.52; Q3: HR, 0.02, 95% CI, 0.14-0.57). CONCLUSIONS This study showed RAF in almost 20% of treated patients and RAF was significantly related to pre-ablation serum levels of LDL-C and TC in women.

[Stapled anoplin peptide combined with photothermal therapy enhances oncolytic immunotherapy of triple-negative breast cancer].

This study constructed a nano-drug delivery system, A3@GMH, by co-delivering the stapled anoplin peptide(Ano-3, A3) with the light-harvesting material graphene oxide(GO), and evaluated its oncolytic immunotherapy effect on triple-negative breast cancer(TNBC). A3@GMH was prepared using an emulsion template method and its physicochemical properties were characterized. The in vivo and in vitro photothermal conversion abilities of A3@GMH were investigated using an infrared thermal imager. The oncoly-tic activity of A3@GMH against TNBC 4T1 cells was evaluated through cell counting kit-8(CCK-8), lactate dehydrogenase(LDH) release, live/dead cell staining, and super-resolution microscopy. The targeting properties of A3@GMH on 4T1 cells were assessed using a high-content imaging system and flow cytometry. In vitro and in vivo studies were conducted to investigate the antitumor mechanism of A3@GMH in combination with photothermal therapy(PTT) through inducing immunogenic cell death(ICD) in 4T1 cells. The results showed that the prepared A3@GMH exhibited distinct mesoporous and coated structures with an average particle size of(308.9±7.5) nm and a surface potential of(-6.79±0.58) mV. The encapsulation efficiency and drug loading of A3 were 23.9%±0.6% and 20.5%±0.5%, respectively. A3@GMH demonstrated excellent photothermal conversion ability and biological safety. A3@GMH actively mediated oncolytic features such as 4T1 cell lysis and LDH release, as well as ICD effects, and showed enhanced in vitro antitumor activity when combined with PTT. In vivo, A3@GMH efficiently induced ICD effects with two rounds of PTT, activated the host's antitumor immune response, and effectively suppressed tumor growth in 4T1 tumor-bearing mice, achieving an 88.9% tumor inhibition rate with no apparent toxic side effects. This study suggests that the combination of stapled anoplin peptide and PTT significantly enhances the oncolytic immunotherapy for TNBC and provides a basis for the innovative application of anti-tumor peptides derived from TCM in TNBC treatment.

Vanadium Oxides with Amorphous-Crystalline Heterointerface Network for Aqueous Zinc-Ion Batteries.

Rechargeable aqueous Zn-VOx batteries are attracting attention in large scale energy storage applications. Yet, the sluggish Zn2+ diffusion kinetics and ambiguous structure-property relationship are always challenging to fulfil the great potential of the batteries. Here we electrodeposit vanadium oxide nanobelts (VO-E) with highly disordered structure. The electrode achieves high capacities (e.g., ≈5 mAh cm-2 , 516 mAh g-1 ), good rate and cycling performances. Detailed structure analysis indicates VO-E is composed of integrated amorphous-crystalline nanoscale domains, forming an efficient heterointerface network in the bulk electrode, which accounts for the good electrochemical properties. Theoretical calculations indicate that the amorphous-crystalline heterostructure exhibits the favorable cation adsorption and lower ion diffusion energy barriers compared to the amorphous and crystalline counterparts, thus accelerating charge carrier mobility and electrochemical activity of the electrode.

Decavanadate Doped Polyaniline for Aqueous Zinc Batteries.

Polyaniline (PANI) is a promising cathode material for aqueous rechargeable zinc batteries (ARZBs), mainly benefitting from its good electrical conductivity. The high conductivity of PANI requires high doping level, yet the introduced nonactive dopants (e.g., SO4 2- ) limit the gravimetric capacity of PANI (usually < 180 mAh g-1 ). Herein, an electro-active dopant (decavanadate anion, V10 O28 6- ) is employed to fabricate the PANI cathode (PANI-V10 O28 ) for ARZBs. The doped decavanadate anion with the sub-nanometer structure can fully expose the V-based active sites, exhibiting good electrochemical activity. Due to the steric hindrance effect as well as the strong interaction between decavanadate anions and PANI chains, the active dopants are trapped in the polymer chains, demonstrating good structural and electrochemical stability. PANI-V10 O28 achieves a record-high gravimetric capacity of 355 mAh g-1 at 0.1 A g-1 , which is significantly higher than other reported PANI cathodes. Experimental results suggest that the charge storage mechanism of PANI-V10 O28 includes reversible injection/extraction of Zn(H2 O)2 Cl4 2- ions in PANI, as well as the protonation/deprotonation of V10 O28 6- . This work enriches the doping chemistry of conducting polymer and pushes the development of organic cathodes for ARZBs to a new stage.

Observation of synergistic antibacterial properties of prodigiosin from Serratia marcescens jx-1 with metal ions in clinical isolates of Staphylococcus aureus.

Methicillin-resistant Staphylococcus aureus (MRSA) infections are a major global health problem, and novel and effective antimicrobial drugs are urgently required to combat this life-threatening pathogen. Prodigiosin (PG) is a bacterial secondary metabolite with excellent anticancer and antibacterial properties. However, little is known about the antibacterial function of PG against MRSA. Therefore, the antibacterial efficacy of PG alone and PG in combination with different metal ions against clinic isolates of MRSA and methicillin-sensitive S. aureus (MSSA) strain was evaluated in the present study. The minimum inhibitory concentration of PG against both MRSA and MSSA was 0.25 µg/mL. However, 0.1 µg/mL PG showed a stronger inhibitory effect on MSSA cell growth (47.12%) than on MRSA cell growth (35.87%). Surprisingly, we observed a significant difference (p < 0.01) in membrane integrity between PG-treated MRSA and MSSA using the propidium iodide staining assay. Further, we found that in combination with PG, Zn2+, Al3+, and Cu2+ showed synergistic antibacterial effects against MRSA and MSSA. Our results could increase the current knowledge regarding the efficacy of PG in inhibiting the growth of different types of S. aureus clinical isolates and also offer a novel strategy for developing efficient antibacterial agents.

Solid-Liquid Interfacial Coordination Chemistry Enables High-Capacity Ammonium Storage in Amorphous Manganese Phosphate.

Ammonium (NH4 + ) ion as charge carrier is attracting attention in aqueous batteries. Yet, most NH4 + host materials are still limited by the relatively low capacities. Here, we fabricated a manganese phosphate (MP-20) for NH4 + ion storage. MP-20 displays a high capacity of 299.6 mAh g-1 at 1 A g-1 in ammonium acetate (NH4 Ac) electrolyte, outperforming other reported NH4 + host materials. Spectroscopy studies suggest a new NH4 + /H+ co-insertion mechanism. We surprisingly discover that the NH4 Ac electrolyte plays an important role in improving the charge storage capability of the materials. Experimental and computational results indicate acetate ions can form coordination bonds with the Mn atoms, tailoring the electronic structure of the Mn atoms and the surrounding O atoms, and therefore facilitating the NH4 + storage process. Our findings provide a new NH4 + host material and propose the important role of the electrolyte-electrode coordination effect in aqueous ammonium batteries.

Characteristics of bone metabolism in postmenopausal female patients with different types of idiopathic benign paroxysmal positional vertigo: A single-centre retrospective study.

OBJECTIVE: The association between benign paroxysmal positional vertigo (BPPV) and impaired calcium metabolism has attracted widespread interest. Several studies have suggested that decreased bone mineral density (BMD) and serum 25-hydroxyvitamin D (25(OH)D) level are related to the occurrence and/or recurrence of BPPV; however, the characteristics of bone metabolism in patients with BPPV subtypes have not been fully investigated, and conclusions have been controversial. This study aimed to evaluate BMD and serum levels of 25(OH)D and bone turnover markers to clarify the characteristics of bone metabolism in patients with different types of BPPV. METHOD: We retrospectively analysed the data of new-onset idiopathic postmenopausal female patients with BPPV at our institution from January 2016 to January 2020. The patients' demographic data including age, medication history, concomitant diseases, onset time, clinical form, laboratory indicators, such as serum levels of 25(OH)D, bone formation markers, namely, amino-terminal propeptide of type I procollagen (PINP) and osteocalcin (OC), bone resorption marker, namely, ß-isomerized carboxy-terminal telopeptide of type I collagen (ß-CTX), and BMD were collected and analysed. RESULTS: This study included 201 consecutive postmenopausal female patients with BPPV. Among them, 138 were diagnosed with posterior semicircular canal BPPV, 42 were diagnosed with lateral semicircular canal canalolithiasis, and 21 were diagnosed with lateral semicircular canal cupulolithiasis. There were no significant differences in age distribution, body mass index, clinical history, levels of albumin, globulin, uric acid, creatinine, or blood urea nitrogen, lipid profiles (except high-density lipoprotein cholesterol) and routine blood parameters among these groups (P > 0.05). There were no significant differences in the mean T-score and BMD values of different sites or in the serum levels of 25(OH)D and bone turnover markers (PINP, OC and ß-CTX) among the subgroups (P > 0.05). The proportion of reduction in BMD (T-score < -1 SD) and decreased serum vitamin D level (< 20 ng/ml) were not significantly different between the subgroups (P > 0.05). CONCLUSION: There were no significant differences in bone metabolism in postmenopausal female patients with different types of idiopathic BPPV.

Ammonium-Ion Storage Using Electrodeposited Manganese Oxides.

NH4 + ions as charge carriers show potential for aqueous rechargeable batteries. Studied here for the first time is the NH4 + -storage chemistry using electrodeposited manganese oxide (MnOx ). MnOx experiences morphology and phase transformations during charge/discharge in dilute ammonium acetate (NH4 Ac) electrolyte. The NH4 Ac concentration plays an important role in NH4 + storage for MnOx . The transformed MnOx with a layered structure delivers a high specific capacity (176 mAh g-1 ) at a current density of 0.5 A g-1 , and exhibits good cycling stability over 10 000 cycles in 0.5 M NH4 Ac, outperforming the state-of-the-art NH4 + hosting materials. Experimental results suggest a solid-solution behavior associated with NH4 + migration in layered MnOx . Spectroscopy studies and theoretical calculations show that the reversible NH4 + insertion/deinsertion is accompanied by hydrogen-bond formation/breaking between NH4 + and the MnOx layers. These findings provide a new prototype (i.e., layered MnOx ) for NH4 + -based energy storage and contributes to the fundamental understanding of the NH4 + -storage mechanism for metal oxides.

Late clinical outcomes of lambre versus amplatzer occluders for left atrial appendage closure.

INTRODUCTION: The LAmbre (LifeTech Scientific, Shenzhen, China) is a novel occluder for left atrial appendage closure (LAAC) in patients with atrial fibrillation. This study compares late clinical outcomes of LAmbre and the established Amplatzer devices (Abbott, St Paul, MN). METHODS: Between 2012 and 2018, 265 consecutive patients underwent LAAC with LAmbre and Amplatzer devices at a single center. After a 3:1 propensity score matching, 40 (LAmbre) vs 107 (Amplatzer) patients were compared by the primary efficacy endpoint of all-cause stroke, systemic embolism and cardiovascular/unexplained death, the primary safety endpoint of major periprocedural complications and major bleeding events at follow-up, and the combined hazard endpoint, a composite of all the above-mentioned hazards. RESULTS: The mean age 75.6 ± 8.9 (LAmbre) vs 75.5 ± 9.0 (Amplatzer) years, CHA2 DS2 -VASc score 4.8 ± 1.7 vs 4.8 ± 1.7 and HAS-BLED score 3.1 ± 0.9 vs 3.2 ± 0.8 were similar. After 3.6 ± 1.9 vs 2.5 ± 1.4 years, the clinical efficacy (12/146, 8.2% [LAmbre] vs 28/266, 10.5% [Amplatzer]; hazard ratio [HR], 0.73; 95% confidence interval [CI], 0.38-1.40; P = .34) and safety (5/146, 3.4% vs 14/266, 5.3%; HR, 0.47; 95% CI, 0.14-1.6; P = .22), as well as the combined hazard endpoint (15/146, 10.3% vs 36/266, 13.6%; HR, 0.67; 95% CI, 0.36-1.25; P = .21) were comparable. CONCLUSION: In the presented report, in patients with nonvalvular atrial fibrillation, the LAmbre offered similar long-term efficacy and safety in comparison to Amplatzer devices.

The Development of Vanadyl Phosphate Cathode Materials for Energy Storage Systems: A Review.

Various cathode materials have been proposed for high-performance rechargeable batteries. Vanadyl phosphate is an important member of the polyanion cathode family. VOPO4 has seven known crystal polymorphs with tunneled or layered frameworks, which allow facile cation (de)intercalations. Two-electron transfer per formula unit can be realized by using VV /VIV and VIV /VIII redox couples. The electrochemical performance is closely related to the structures of VOPO4 and the types of inserted cations. This Review outlines the crystal structures of VOPO4 polymorphs and their lithiated phases. The research progress of vanadyl phosphate cathode materials for different energy storage systems, including lithium-ion batteries, sodium-ion batteries, potassium-ion batteries, multivalent batteries, and supercapacitors, as well as the related mechanism investigations are summarized. It is hoped that this Review will help with future directions of using vanadyl phosphate materials for energy storage.

Propensity-matched comparison of antiplatelet versus anticoagulant after left atrial appendage closure with the Watchman.

BACKGROUND: Optimal antithrombotic therapy following left atrial appendage closure (LAAC) with the Watchman occluder remains uncertain. This study retrospectively compared clinical outcomes of a 3-month dual antiplatelet therapy (DAPT group) and a protocol of anticoagulation plus aspirin for 45 days followed by DAPT for 6 months (ACT group) after LAAC with the Watchman device. METHODS: Of two Watchman registries (Coburg and Lichtenfels hospitals, Germany), 220 and 304 consecutive patients with successful LAAC were included. Patients in Coburg hospital received DAPT while they received ACT in Lichtenfels. After a 1:1 propensity score matching, 174 (DAPT) versus 174 (ACT) patients were compared by use of the primary efficacy endpoint of thromboembolic events and cardiovascular/unexplained death, the primary safety endpoint of nonprocedural related major bleeding events at follow-up, and the combined hazard endpoint, a composite of all above-mentioned hazards. RESULTS: The mean age 77.5 ± 7.2 (DAPT) versus 77.3 ± 7.1 (ACT) years, CHA2 DS2 -VASc score 4.6 ± 1.5 versus 4.7 ± 1.6, and HAS-BLED score 3.3 ± 0.8 versus 3.3 ± 0.8 were similar. After 12 months, the clinical efficacy (13/174, 7.4% [DAPT] vs 11/174, 6.3% [ACT]; hazard ratio [HR], 0.84; 95% confidence interval [CI], 0.38-1.86; P = .66) and safety (6/174, 3.4% vs 8/174, 4.5%; HR, 0.86; 95% CI, 0.29-2.56; P = .79) as well as the combined hazard endpoint (18/174, 10.3% vs 18/174, 10.3%; HR,1.01; 95% CI, 0.53-1.95; P = .97) were comparable. CONCLUSIONS: This study suggests comparable efficacy and safety of 3-month DAPT versus 6 weeks ACT plus aspirin following LAAC with the Watchman.

A capillary electrophoresis strategy to sensitively detect dynamic properties of coiled coil polypeptides.

The self-assembly behavior of polypeptides plays an essential role to form biological and functional macromolecules, which have attracted a lot of attention due to their excellent characters. Understanding the polypeptide self-assembly systems and dynamic behaviors is fundamental to improve the potential of biomedical applications. In this work, coiled coil polypeptides PC10 and PC10 P were designed and biosynthesized. PC10 and PC10 P could form nanogels when the concentration of polypeptides was less than 2% (m/v). The dynamic behaviors of PC10 and PC10 P were measured by Förster resonance energy transfer method based on a capillary electrophoresis system. The Förster resonance energy transfer efficiency of this system was 60.4%, and the distance of self-assembled domains in the polypeptides was calculated as 6.14 nm, demonstrating that the exchange behavior occurred between two different polypeptides containing the same coiled coil region.

Human DNA Polymerase µ Can Use a Noncanonical Mechanism for Multiple Mn2+-Mediated Functions.

Recent research on the structure and mechanism of DNA polymerases has continued to generate fundamentally important features, including a noncanonical pathway involving "prebinding" of metal-bound dNTP (MdNTP) in the absence of DNA. While this noncanonical mechanism was shown to be a possible subset for African swine fever DNA polymerase X (Pol X) and human Pol λ, it remains unknown whether it could be the primary pathway for a DNA polymerase. Pol µ is a unique member of the X-family with multiple functions and with unusual Mn2+ preference. Here we report that Pol µ not only prebinds MdNTP in a catalytically active conformation but also exerts a Mn2+ over Mg2+ preference at this early stage of catalysis, for various functions: incorporation of dNTP into a single nucleotide gapped DNA, incorporation of rNTP in the nonhomologous end joining (NHEJ) repair, incorporation of dNTP to an ssDNA, and incorporation of an 8-oxo-dGTP opposite template dA (mismatched) or dC (matched). The structural basis of this noncanonical mechanism and Mn2+ over Mg2+ preference in these functions was analyzed by solving 19 structures of prebinding binary complexes, precatalytic ternary complexes, and product complexes. The results suggest that the noncanonical pathway is functionally relevant for the multiple functions of Pol µ. Overall, this work provides the structural and mechanistic basis for the long-standing puzzle in the Mn2+ preference of Pol µ and expands the landscape of the possible mechanisms of DNA polymerases to include both mechanistic pathways.

A two-circular RNA signature as a noninvasive diagnostic biomarker for lung adenocarcinoma.

BACKGROUND: Recently, circular RNAs (circRNAs) have been reported to be microRNA sponges and play essential roles in cancer development. This study aimed to evaluate whether circulating circRNAs could be used as diagnostic biomarkers for lung adenocarcinoma (LUAD). METHODS: The Gene Expression Omnibus (GEO) dataset was used to investigate differentially expressed circRNAs (DEcircRNAs) in paired LUAD tissues and adjacent nontumor tissues. The expression levels of the host genes were analyzed in The Cancer Genome Atlas (TCGA)-LUAD dataset, and the prognostic value was assessed using the Kaplan-Meier plotter. Quantitative real-time PCR (qRT-PCR) was performed to validate the expression of candidate circRNAs in the LUAD plasma and cells. The CCK8 assay was used to measure the function of circRNAs in cell proliferation. Competing endogenous RNA (ceRNA) network, gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed to predict the possible mechanisms and functions of circRNAs in LUAD. RESULTS: Two upregulated and two downregulated circRNAs were identified as candidate circRNAs using bioinformatics analysis. qRT-PCR demonstrated that hsa_circ_0005962 was upregulated in LUAD plasma and cells, whereas hsa_circ_0086414 was downregulated. Receiver operating characteristic (ROC) curve analysis confirmed that a signature comprising the two circRNAs had good diagnostic potential, with an area under the ROC curve (AUC) of 0.81 (P < 0.0001). In addition, we observed that overexpression of plasma hsa_circ_0086414 was related to EGFR mutations (P = 0.001). Plasma hsa_circ_0005962 displayed significantly different expression before and after surgery in patients with LUAD (P < 0.0001). In vitro experiments suggested that hsa_circ_0005962 promoted LUAD cell proliferation. For future studies, we predicted the circRNA-miRNA-mRNA network for hsa_circ_0005962. Bioinformatics analysis revealed that hsa_circ_0005962 might be involved in LUAD development. CONCLUSION: A circRNA signature was identified as a potential noninvasive biomarker for LUAD diagnosis.

Inhibiting VOPO4 ⋠x H2 O Decomposition and Dissolution in Rechargeable Aqueous Zinc Batteries to Promote Voltage and Capacity Stabilities.

VOPO4 ⋅x H2 O has been proposed as a cathode for rechargeable aqueous zinc batteries. However, it undergoes significant voltage decay in conventional Zn(OTf)2 electrolyte. Investigations show the decomposition of VOPO4 ⋅x H2 O into VOx in the electrolyte and voltage drops after losing the inductive effect from polyanions.PO4 3- was thus added to shift the decomposition equilibrium. A high concentration of cheap, highly soluble ZnCl2 salt in the electrolyte further prevents VOPO4 ⋅x H2 O dissolution. The cathode shows stable capacity and voltage retentions in 13 m ZnCl2 /0.8 m H3 PO4 aqueous electrolyte, in direct contrast to that in Zn(OTf)2 where the decomposition product VOx provides most electrochemical activity over cycling. Sequential H+ and Zn2+ intercalations into the structure are revealed, delivering a high capacity (170 mAh g-1 ). This work shows the potential issue with polyanion cathodes in zinc batteries and proposes an effective solution using fundamental chemical principles.

Evolutionary relationships between seryl-histidine dipeptide and modern serine proteases from the analysis based on mass spectrometry and bioinformatics.

Seryl-histidine dipeptide (Ser-His) has been recognized as the shortest peptide with hydrolysis cleavage activity; however, its protein cleavage spectrum has not yet been fully explored. Here, four differently folded proteins were treated with Ser-His, and the digestion products were evaluated with high-resolution mass spectrometry. The cleavage efficiency and cleavage propensity of Ser-His against these protein substrates were calculated at both the primary and secondary sequence levels. The above experiments show that Ser-His cleaves a broad spectrum of substrate proteins of varying secondary structures. Moreover, Ser-His could cleave at all 20 amino acids with different efficiencies according to the protein, which means that Ser-His has the original digestion function of serine proteases. Furthermore, we collected and compared the catalytic sites and cleavage sites of 340 extant serine proteases derived from 17 representative organisms. A consensus motif Ser-[X]-His was identified as the major pattern at the catalytic sites of serine proteases from all of the organisms represented except Danio rerio, which uses Ser-Lys instead. This finding indicates that Ser-His is the core component of the serine protease catalytic site. Moreover, our analysis revealed that the cleavage sites of modern serine proteases have become more specific over the evolutionary history of this family. Based on the above analysis results, it could be found that Ser-His is likely the original serine protease and maybe the evolutionary core of modern serine proteases.