Lower Limit Research Articles

Preparation and Properties of High Sound-Absorbing Porous Ceramics Reinforced by In Situ Mullite Whisker from Construction Waste

Porous sound absorption ceramic is one of the most promising materials for effectively eliminating noise pollution. However, its high production cost and low mechanical strength limit its practical applications. In this work, low-cost and in situ mullite whisker-reinforced porous sound-absorbing ceramics were prepared using recyclable construction waste and Al2O3 powder as the main raw materials, and AlF3 and CeO2 as the additives, respectively. The effects of CeO2 content, AlF3 content, and sintering temperature on the microstructure and properties of the porous ceramics were systematically investigated. The results showed that a small amount of CeO2 significantly promoted the growth of elongated mullite crystals in the resultant porous ceramics, decreased the growth temperature of the mullite whiskers, and significantly increased the biaxial flexural strength. When 2 wt.% CeO2 and 12 wt.% AlF3 were added to the system, mullite whiskers were successfully obtained at a sintering temperature of 1300 °C for 1 h, which exhibited excellent properties, including an open porosity of 56.4 ± 0.6%, an average pore size of 1.32–2.54 μm, a biaxial flexural strength of 23.7 ± 0.9 MPa, and a sound absorption coefficient of >0.8 at 800–4000 Hz.

Synthesis of a cysteine functional covalent organic framework via facile click reaction for the efficient solid phase extraction of substituted p-phenylenediamine-derived quinones

N,N′-Substituted p-phenylenediamine quinones (PPD-Qs) are the emerging toxicant, which transform from the rubber tire antioxidant N,N′-substituted p-phenylenediamines (PPDs). Because of their potential toxic and widespread occurrence in the environment, PPD-Qs have received great attention. However, efficiently extracting PPD-Qs from complex samples is still a challenge. Herein, a cysteine functional covalent organic framework (Cys-COF) designed according to the “donor-acceptor” sites of hydrogen bonding of PPD-Qs was synthesized via click reaction and then used as solid-phase extraction (SPE) adsorbent. Cys-COF can form the seven-member ring adsorption structure with PPD-Qs via hydrogen bonding. The adsorption mechanism was tentatively revealed by density functional theory (DFT). After optimizing the Cys-COF-SPE parameters, PPD-Qs were efficiently extracted from water, soil, sediment, and fish, followed by detection using ultra-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). The Cys-COF-SPE-UHPLC-MS/MS method exhibited ideal linearity (R2 ≥ 0.9932), high relative recoveries (80.4–111 %), and low limits of detection (0.0001–0.0013 ng mL−1). In addition, the bioconcentration kinetics in goldfish provides a feasible platform to investigate the toxicity and accumulated ability of PPD-Qs.

Ln-MOFs with in-situ exsolved perovskite as ratiometric fluorescent for H2O and Cu2+: Spacial charge transfer and detection mechanism

Herein, a ratiometric fluorescent sensor based on CPB⊆Pb/Eu-MOF heterojunction has been designed for rapid, sensitive and visual detection of H2O and Cu2+ in extraction solution. The energy transfer from Pb2+ to Eu3+ in Pb/Eu-MOF has enhanced the luminescent emission of Eu3+, and the CPB⊆Pb/Eu-MOF n-n heterojunction with S-scheme charge transfer can stabilize CPB to activate the detecting for H2O and Cu2+. In-situ XPS and XRD have confirmed the phase transformation from cubic CPB to CsPb2Br5 majorly contributes to color switch when being introduced by H2O. Moreover, the dynamic quenching and electron transfer are verified by the adsorption energy Br-Cu bonding according to DFT calculation and the shortened fluorescence lifetime. Typically, 0.2CPB⊆Pb/Eu-MOF composite exhibits a highly sensitive and selective ratiometric fluorescent sensing. The proper linear ranges from 10.80 % to 23.10 % and a low detection limit of 0.26 % for H2O, while 20–180 μM, R2 = 0.996, and 8.09 μM for Cu2+. More importantly, the paper-based sheet sensor has been manufactured practically in the real floral teas and different solvents for the visual detection of H2O and Cu2+ by naked eyes.

The Tumor Risk Score (TRS) - next level risk prediction in head and neck tumor surgery.

Head and neck cancer surgery often requires postoperative monitoring in an intensive care unit (ICU) or intermediate care unit (IMC). With a variety of different risk scores, it is incumbent upon the investigator to plan a risk-adapted allocation of resources. Tumor surgery in the head and neck region itself offers a wide range of procedures in terms of resection extent and reconstruction methods, which can be stratified only vaguely by a cross-disciplinary score. Facing a variety of different risk scores we aimed to develop a new Tumor Risk Score (TRS) enabling anterograde preoperative risk evaluation, resource allocation and optimization of cost and outcome measurements in tumor surgery of the head and neck. A collective of 547 patients (2010-2021) with intraoral tumors was studied to develop the TRS by grading the preoperative tumor size and location as well as the invasiveness of the planned surgery by means of statistical modeling. Two postoperative complications were defined: (1) prolonged postoperative stay in IMC/ICU and (2) prolonged total length of stay (LOS). Each parameter was analyzed using TRS and all preoperative patient parameters (age, sex, preoperative hemoglobin, body-mass-index, preexisting medical conditions) using predictive modeling design. Established risk scores (Charlson Comorbidity Index (CCI), American Society of Anesthesiologists risk classification (ASA), Functional Comorbidity Index (FCI)) and Patient Clinical Complexity Level (PCCL) were used as benchmarks for model performance of the TRS. The TRS is significantly correlated with surgery duration (p < 0.001) and LOS (p = 0.001). With every increase in TRS, LOS rises by 9.3% (95%CI 4.7-13.9; p < 0.001) or 1.9 days (95%CI 1.0-2.8; p < 0.001), respectively. For each increase in TRS, the LOS in IMC/ICU wards increases by 0.33 days (95%CI 0.12-0.54; p = 0.002), and the probability of an overall prolonged IMC/ICU stay increased by 32.3% per TRS class (p < 0.001). Exceeding the planned IMC/ICU LOS, overall LOS increased by 7.7 days (95%CI 5.35-10.08; p < 0.001) and increases the likelihood of also exceeding the upper limit LOS by 70.1% (95%CI 1.02-2.85; p = 0.041). In terms of predictive power of a prolonged IMC/ICU stay, the TRS performs better than previously established risk scores such as ASA or CCI (p = 0.031). The lack of a standardized needs assessment can lead to both under- and overutilization of the IMC/ICU and therefore increased costs and losses in total revenue. Our index helps to stratify the risk of a prolonged IMC/ICU stay preoperatively and to adjust resource allocation in major head and neck tumor surgery.

Scaled experiment and numerical study on the effect of a novel makeup air system on smoke control in atrium fires

In the field of fire safety engineering, makeup air systems design for atriums is always a concern for researchers and engineers. A novel makeup air system integrating breathing zone and underfloor air supply (BUMS) was applied in the investigated atrium in this study. However, the flow rates proportional relationship of makeup air required for effective smoke control on each floor remains unclear. Scaled experiments and numerical simulations were carried out to address this problem in this study. The results show that the BUMS effectively controlled temperature, followed by visibility, with minimal impact on carbon monoxide (CO) concentrations. When the flow rate of makeup air was equal on each floor, the sizes of the safe evacuation passageways created by the BUMS on the third and fourth floors were not conducive to the safe evacuation of personnel. Based on the proportion of the CO concentration of each floor under natural ventilation, distribution proportions of makeup air flow rate were obtained. The effective action area was used to help determine the upper limit flow rate ratio for each floor. Calculation results revealed that when the flow rate distribution proportion for the first to fourth floors was 15 %, 27 %, 28 % and 30 %, respectively, the smoke control effectiveness has been improved. These findings are expected are expected to provide a theoretical basis for designing makeup air systems in atrium and large-space buildings.

Lateral flow assay with dual-emission nitrogen-doped carbon dots for ratiometric fluorescent determination of nitrite in food

Nitrite ion (NO2–), renowned for its potent antiseptic properties and color-preserving abilities, potentially leads to carcinogenesis and hypertension if consumed excessively. Herein, a ratiometric fluorescent probe exhibits specific response to NO2– using nitrogen-doped carbon dots (N-CDs) with a low detection limit (LOD) as low as 52 nM and a low quantification limit (LOQ) of 173 nM. Initially, the emission peaks at 495 nm and 415 nm decrease as result of the internal filtration effect (IFE). With further increasing NO2– concentration, the reaction between NO2– and N-CDs forms an azoic compound (N-CDs@NO2–), which promotes the instant quenching of the emission peak at 415 nm through fluorescence resonance energy transfer (FRET). Moreover, portable N-CDs/LFASs devices with smartphone are successfully applied to visually identify NO2– with the exceptional LOD, achieving excellent recoveries and high precision in real sample. Therefore, this newly N-CDs/LFASs offers a reliable means for the NO2– detection, showcasing potential applications.

Application of polyethylene glycol 8000 as plasticizer for the development of ellagic acid and Eudragit® EPO based solid dispersions using hot melt extrusion.

Solid dispersion formation by Hot melt extrusion (HME) is a widely used formulation strategy to improve the solubility and bioavailability of poorly water-soluble drugs. Despite this, they are limited by various factors such as drug-excipient miscibility, poor stability, limited drug loading and extrudability of physical drug-excipient mixtures. In this work, polyethylene glycol 8000 (PEG 8000) was used as a plasticizer for the manufacture of ellagic acid solid dispersions (EASD) with high drug loading. Indeed, EA is a polyphenolic active compound with antimalarial and other promising therapeutic activities. However, its low solubility and low permeability limit its therapeutic use. Solid dispersions formation may overcome this challenge, but its high melting point negatively influences the extrudability of its binary physical mixtures with a high drug loading rate, hence the need to use a plasticizer. Thus, five formulations consisting of EA, Eudragit® EPO and PEG 8000 in the ratio of 15:75:10 (F1), 20:70:10 (F2), 25:65:10 (F3), 15:80:5 (F4) and 20:85:5 (F5) % w/w, respectively, have been extruded, four of which were successful. The extrudates were evaluated by X-ray powder diffraction, FTIR spectroscopy and in vitro dissolution tests. Based on the results of these tests, the F5 formulation was identified as the most promising. Indeed, after 15 min of dissolution test, the dissolution rate of ellagic acid from the formulations was 62.67±3.10%, 58.74±7.23 %, 88.75±3.02% and 83.47±4.40% respectively for formulation F1, F2, F4 and F5. Moreover, the results of the FTIR spectroscopy analyses showed stronger interactions between the different constituents in the F4 and 5 formulations compared to the F1 and 2 formulations. Extruded materials of the F5 formulation, characterized by solid state nuclear magnetic resonance (ssNMR) spectroscopy and subjected to stability studies, showed good physical stability for twelve months under real-time stability study conditions and for six months under accelerated conditions.

Zeolitic Imidazolate Framework-8 enhanced with tungsten carbide for high-performance hybrid supercapacitors and hydrogen evolution

A promising metal-organic framework (MOF) called Zeolitic Imidazolate Framework-8 (ZIF-8) stands out for its electrochemical applications. Its versatility in physicochemical properties makes it a strong candidate for breakthroughs in energy storage and electrochemical water splitting. The electrode nanomaterials lower specific capacity, small charging/discharging rate, and low conductivity limit its supercapacitor and hydrogen evaluation reaction (HER) applications. The ZIF-8 zeolite structure was decorated with tungsten carbide (WC) to overcome these issues. These modifications result in improved porosity, surface area, density, and pore size, shape, and structure. These characteristics contribute significantly to enhanced electrochemical activity. ZIF-8 MOF/WC nanocomposites have excellent dispersion and stability due to their porosity and strong connection between embedded WC nanoclusters and the framework. The prepared electrode showed a 118.11 mV overpotential and 36.45 mV/dec Tafel slope throughout HER activity. ZIF-8 MOF/WC was used for electrochemical studies and to make a hybrid energy storage device using activated carbon (AC). The hybrid supercapacitor had higher energy and power densities (87 W h/kg and 850 W/kg). The theoretical technique (Dunn model) was also employed to analyze experimental results more thoroughly.

Immunological assay using a solid-state pore with a low limit of detection

Emerging infectious diseases, cancer, and other diseases are quickly tested mainly via immune reactions based on specific molecular recognition between antigens and antibodies. By changing the diameter of solid-state pores, biomolecules of various sizes can be rapidly detected at the single-molecule level. The combination of immunoreactions and solid-state pores paves the way for an efficient testing method with high specificity and sensitivity. The challenge in developing this method is achieving quantitative analysis using solid-state pores. Here, we demonstrate a method with a low limit of detection for testing tumor markers using a combination of immunoreactions and solid-state pore technology. Quantitative analysis of the mixing ratio of two and three beads with different diameters was achieved with an error rate of up to 4.7%. The hybrid solid-state pore and immunoreaction methods with prostate-specific antigen (PSA) and anti-PSA antibody-modified beads achieved a detection limit of 24.9 fM PSA in 30 min. The hybrid solid-state pore and immunoreaction enabled the rapid development of easy-to-use tests with lower limit of detection and greater throughput than commercially available immunoassay for point-of-care testing.

Zeolitic imidazolate framework-8 as a high-affinity adsorbent for dispersive solid-phase extraction in the analysis of plant growth regulators in fruits.

Facile and sensitive determination of plant growth regulators (PGRs) in food samples is crucial but still poses a significant challenge. In this study, to enhance the sensitivity of the HPLC-DAD method for PGR detection, a dispersive solid phase extraction (d-SPE) method using zeolitic imidazolate framework-8 (ZIF-8) as the highly effective adsorbent is developed. ZIF-8 nanoparticles are formed through the coordination of Zn2+ with 2-methylimidazole. Due to its high porosity, large surface area, abundant π electronics and nitrogen electronics, ZIF-8 exhibits a strong affinity to PGRs due to the synergistic effects of π-π interaction, van der Waals force, H-bond, and surface effect. Under the optimal d-SPE conditions, the sensitivity of the method is significantly enhanced with outstanding performances, including a wide range of linearity (2.0-200 ng g-1) with high correlation coefficients (R ≥ 0.9989), low limits of detection (LODs, 0.9-8.0 ng g-1 for all PGRs), satisfactory precision (intra-day RSDs ≤ 3.3%, inter-day RSDs ≤ 4.2%), and high accuracy (recovery: 86.6-101.5%). The developed method was successfully applied to quantitatively detect 9 PGRs in fruit samples, yielding satisfactory results. This d-SPE-HPLC-DAD method, characterized by high sensitivity, simplicity, efficiency, ease of practice and cost-effectiveness for PGR detection, shows potential for detecting PGRs in other complex samples and provides a strategy for designing target-affinity adsorbents.

Assessment of intestinal inflammation via fecal calprotectin for early prediction of adverse outcomes in advanced chronic liver disease.

Intestinal inflammation assessed by fecal calprotectin (F-CAL) in advanced chronic liver disease (ACLD) may represent an early sign of intestinal barrier dysfunction. We aimed to explore the usefulness of F-CAL testing in ACLD in the prediction of adverse outcomes (AO, death, or LT) and refinement of prognostic stratification. We explored the RH7 cirrhosis registry comprising consecutive hospitalized patients and a control group with data on disease phenotype, demographics, anthropometrics, prognostic indices, and medication. The F-CAL was evaluated on admission and reported in multiples of the upper limit of normal or terciles. Predictive power was tested in the Cox model for AO over 180days. Additional risk refinement by F-CAL was tested for both groups. We enrolled 263 cases in the study group with a median age of 57.2years, M/F ratio 167/96, with alcohol, metabolic dysfunction-associated steatotic liver disease, MetALD, and viral etiologies in 72.2%, 9.1, 8.0, 3.4%. The median F-CAL was 3.92×ULN. The control group comprised 108 cases. The adjusted Cox model confirmed F-CAL (hazard ratio [HR]=1.05, p<0.001) and F-CAL terciles (HR=1.413, p=0.009) as independent predictors of AO. F-CAL terciles had higher predictive accuracy in CLIF-C-AD<50 (HR=2.49, p=0.013) and Child stages A and B (HR=1.706, p=0.025), in whom high F-CAL (cut-off >11×ULN) could identify patients having 2-3 times higher risk of AO. This approach has been validated in the control group. Among hospitalized patients with ACLD, F-CAL values were independently proportional to the risk of AO, particularly in early disease stages when high F-CAL values could refine prognostic stratification.

Nonlinear properties of uni-directional cellulose nanofiber-reinforced poly (lactic acid) composite filaments: a multiscale computational study

In the quest to elevate the mechanical properties of cellulose nanofiber-reinforced poly (lactic acid) composite materials for robust industrial applications, we conducted multiscale nonlinear finite element analysis rooted in homogenization theory. Our study delved into the intricate web of mechanical mechanisms and their pivotal influencers. This paper zeroed in on three paramount factors: the distribution of fibers, the fiber–matrix interface, and the aspect ratio of the fibers. For fiber distribution, we assumed fiber orientation control in fused filament fabrication and clarified the limit of material improvement by setting one-dimensional orientation as the upper limit. Our analysis of the fiber–matrix interface proposed a comprehensive three-scale structure, encompassing microstructures featuring intricate interfacial phases around the fibers, sub-microstructures with myriad dispersed fibers, and macrostructures subjected to external loads. The profound impact of the fiber–matrix interface on material properties was unveiled through a meticulous two-step homogenization process. Furthermore, we examined the substantial influence of the fiber aspect ratio on material properties. By unraveling the complex interplay among these critical factors, this research provided new design guidelines for fiber morphology to the performance of cellulose composites.

SERS biosensors based on catalytic hairpin self-assembly and hybridization chain reaction cascade signal amplification strategies for ultrasensitive microRNA-21 detection.

A highly sensitive surface-enhanced Raman scattering (SERS) biosensor has been developedfor the detection of microRNA-21 (miR-21) using an isothermal enzyme-free cascade amplification method involving catalytic hairpin assembly (CHA) and hybridization chain reaction (HCR). The CHA reaction is triggered by the target miR-21, which causes hairpin DNA (C1 and C2) to self-assemble into CHA products. After AgNPs@Capture captures the resulting CHA product, the HCR reaction is started, forming long-stranded DNA on the surface of AgNPs. A strong SERS signal is generated due to the presence of a large amount of the Raman reporter methylene blue (MB) in the vicinity of the SERS "hot spot" on the surface of AgNPs. The monitoring of the SERS signal changes of MB allows for the highly sensitive and specific detection of miR-21. In optimal conditions, the biosensor exhibits a satisfactory linear range and a low detection limit for miR-21 of 42.3 fM. Additionally, this SERS biosensor shows outstanding selectivity and reproducibility. The application of this methodology to clinical blood samples allows for the differentiation of cancer patients from healthy controls. As a result, the CHA-HCR amplification strategy used in this SERS biosensor could be a useful tool for miRNA detection and early cancer screening.

Collaborative CRISPR-Cas System-Enabled Detection of Circulating Circular RNA for Reliable Monitoring of Acute Myocardial Infarction.

Acute myocardial infarction (AMI) is one of the major causes of death worldwide, posing significant global health challenges. Circular RNA (circRNA) has recently emerged as a potential diagnostic biomarker for AMI, providing valuable information for timely medical care. In this work, a new electrochemical method for circRNA detection by engineering a collaborative CRISPR-Cas system is developed. This system integrates the unique circRNA-targeting ability with cascade trans-cleavage activities of Cas effectors, using an isothermal primer exchange reaction as the bridge. Using cZNF292, a circulating circRNA biomarker for AMI is identified by this group; as a model, the collaborative CRISPR-Cas system-based method exhibits excellent accuracy and sensitivity with a low detection limit of 2.13 × 10-15 m. Moreover, the method demonstrates a good diagnostic performance for AMI when analyzing whole blood samples. Therefore, the method may provide new insight into the detection of circRNA biomarkers and is expected to have great potential in AMI diagnosis in the future.

Electrochemically deposited Au nano-island on laser-scribed graphene substrates as EC-SERS biochips for uremic toxins detection

BackgroundChronic kidney disease (CKD) leads to uremic toxin buildup, requiring early detection for better management. Existing methods lack sensitivity, speed, or affordability for point-of-care diagnosis. This work addresses this by creating a novel sensor for rapid, sensitive uremic toxin detection. MethodsThe sensor leverages the combined effects of surface-enhanced Raman scattering (SERS) and electrochemistry (EC) for superior detection. The LIG substrate provides a stable platform for AuNPs, facilitating interaction with target molecules. Additionally, electrochemical deposition optimizes the sensor's sensitivity by amplifying the local electromagnetic field around AuNPs and offering specific binding sites for uremic toxins. Significant findingsThe developed sensor demonstrates exceptional performance in detecting uremic toxins. It achieves remarkably low detection limits (10-3 M for creatinine/uric acid, 10-4 M for urea) and offers distinct, concentration-dependent responses for different toxins in cyclic voltammetry (CV) measurements. Furthermore, characteristic oxidation peaks at specific potentials allow for direct identification and quantification of the toxins. These findings highlight the immense potential of this cost-effective and scalable sensor for point-of-care diagnostics and remote monitoring of kidney function. This advancement can significantly improve patient care by facilitating early detection of kidney problems and enabling timely intervention.

The synergistic effect of MnSe2/pyridine diketopyrrolopyrrole-grafted graphene oxide composite for sensitivity electrochemical detection of 4-nitrochlorobenzene

In view of the hazards and degradation inertia of 4-nitrochlorobenzene (4-NCB), it is very important to detect the content of 4-NCB in water samples. Here, we developed a simple platform to accurately monitor the content of 4-NCB based on MnSe2/pyridine diketopyrrolopyrrole-grafted graphene oxide nanocomposite (MnSe2/PDPP-rGO) constructed glass carbon electrode (GCE) sensor. MnSe2/PDPP-rGO composited has been synthesized by two-step hydrothermal method, and MnSe2 nanoclusters composed of nanorods grows uniformly on the surface of PDPP-rGO lamella. Combined with electrochemical activity of MnSe2 to 4-NCB and the excellent conductivity of PDPP-rGO which have been confirmed by cyclic voltammetry and electrochemical impedance spectroscopy, the as-prepared MnSe2/PDPP-rGO/GCE displays outstanding electrochemical sensing comprehensive performance to 4-NCB with wide linear range of 0.05–280 μM, low limit of detection of 4.8 nM, long stability for up to 20 days, satisfactory interference and repeatability. These results provide sufficient basis for accurate and practical detection of 4-NCB based on MnSe2/PDPP-rGO/GCE platform.

Efficacy Analysis of PTCD + TACE vs PTCD + Apatinib in the Treatment of HCC with Obstructive Jaundice: A Retrospective Study.

The aim was to evaluate the safety and effectiveness of PTCD combined with TACE in the treatment of hepatocellular carcinoma with obstructive jaundice and to compare the efficacy of TACE in patients with different levels of bilirubin after PTCD. The clinical data of 141 patients with HCC complicated with obstructive jaundice were analyzed retrospectively. The patients underwent PTCD first. When the total bilirubin decreased, the patients received TACE or Apatinib treatment. They were divided into two groups: (1) PTCD+TACE group, N=68; (2) PTCD+Apatinib group, N=73. The PTCD+TACE group had higher ORR and DCR than the PTCD+Apatinib group (57.4% vs 12.3%, p < 0.001;80.9% vs 60.3%, p = 0.010). The mPFS of the PTCD+TACE group was longer than that of the PTCD+Apatinib group (7.1 months vs 3.8 months, p < 0.001). The mOS of the PTCD+TACE group was longer than that of the PTCD+Apatinib group(11.5 months vs 7.7 months, p < 0.001). In the subgroup analysis of the PTCD+TACE group, the results showed that the survival benefits of the groups with total bilirubin <2 times and 2-3 times were greater. In patients with HCC and obstructive jaundice, superselective TACE(lipiodol+epirubicin emulsion) significantly prolonged OS and PFS compared with Apatinib after using PTCD to reduce total bilirubin to <100umol/L. Patients whose total bilirubin dropped to ≤3 times of the upper limit of normal value after PTCD had longer OS and PFS than patients >3 times.

TESS Giants Transiting Giants. VI. Newly Discovered Hot Jupiters Provide Evidence for Efficient Obliquity Damping after the Main Sequence

The degree of alignment between a star’s spin axis and the orbital plane of its planets (the stellar obliquity) is related to interesting and poorly understood processes that occur during planet formation and evolution. Hot Jupiters orbiting hot stars (≳6250 K) display a wide range of obliquities, while similar planets orbiting cool stars are preferentially aligned. Tidal dissipation is expected to be more rapid in stars with thick convective envelopes, potentially explaining this trend. Evolved stars provide an opportunity to test the damping hypothesis, particularly stars that were hot on the main sequence and have since cooled and developed deep convective envelopes. We present the first systematic study of the obliquities of hot Jupiters orbiting subgiants that recently developed convective envelopes using Rossiter–McLaughlin observations. Our sample includes two newly discovered systems in the Giants Transiting Giants survey (TOI-6029 b, TOI-4379 b). We find that the orbits of hot Jupiters orbiting subgiants that have cooled below ∼6250 K are aligned or nearly aligned with the spin axis of their host stars, indicating rapid tidal realignment after the emergence of a stellar convective envelope. We place an upper limit for the timescale of realignment for hot Jupiters orbiting subgiants at ∼500 Myr. Comparison with a simplified tidal evolution model shows that obliquity damping needs to be ∼4 orders of magnitude more efficient than orbital period decay to damp the obliquity without destroying the planet, which is consistent with recent predictions for tidal dissipation from inertial waves excited by hot Jupiters on misaligned orbits.

Light axion-like particles and the pseudoscalar mesonic decays M⃗M′νν¯

The axion-like particle (ALP) is one kind of the best-motivated new particles. We consider its production from the pseudoscalar mesonic decays M→M′a , with M being a pseudoscalar meson B or K. The upper limits on the flavor-conserving ALP–quark coupling parameter g u are obtained by assuming the ALP to be an invisible particle. We find that the most severe constraint on g u comes from the decay K+→π+νν¯ for 0.05 GeV ≤ M a ≤ 0.35 GeV, while the decays B+,0→K+,0νν¯ and B+,0→π+,0νν¯ can also generate significant constraints.

A ~40-kb flavi-like virus does not encode a known error-correcting mechanism

It is commonly held that there is a fundamental relationship between genome size and error rate, manifest as a notional "error threshold" that sets an upper limit on genome sizes. The genome sizes of RNA viruses, which have intrinsically high mutation rates due to a lack of mechanisms for error correction, must therefore be small to avoid accumulating an excessive number of deleterious mutations that will ultimately lead to population extinction. The proposed exceptions to this evolutionary rule are RNA viruses from the order Nidovirales (such as coronaviruses) that encode error-correcting exonucleases, enabling them to reach genome lengths greater than 40 kb. The recent discovery of large-genome flavi-like viruses (Flaviviridae), which comprise genomes up to 27 kb in length yet seemingly do not encode exonuclease domains, has led to the proposal that a proofreading mechanism is required to facilitate the expansion of nonsegmented RNA virus genomes above 30 kb. Herein, we describe a ~40 kb flavi-like virus identified in a Haliclona sponge metatranscriptome that does not encode a known exonuclease. Structural analysis revealed that this virus may have instead captured cellular domains associated with nucleic acid metabolism that have not been previously found in RNA viruses. Phylogenetic inference placed this virus as a divergent pesti-like lineage, such that we have provisionally termed it "Maximus pesti-like virus." This virus represents an instance of a flavi-like virus achieving a genome size comparable to that of the Nidovirales and demonstrates that RNA viruses have evolved multiple solutions to overcome the error threshold.