Supercooled erythritol for high-performance seasonal thermal energy storage.

Seasonal storage of solar thermal energy through supercooled phase change materials (PCM) offers a promising solution for decarbonizing space and water heating in winter. Despite the high energy density and adaptability, natural PCMs often lack the necessary supercooling for stable, long-term storage. Leveraging erythritol, a sustainable mid-temperature PCM with high latent heat, we introduce a straightforward method to stabilize its supercooling by incorporating carrageenan (CG), a bio-derived food thickener. By improving the solid-liquid interfacial energy with the addition of CG the latent heat of erythritol can be effectively locked at a very low temperature. We show that the composite PCM can sustain an ultrastable supercooled state below -30 °C, which guarantees no accidental loss of the latent heat in severe cold regions on Earth. We further demonstrate that the common ultrasonication method can be used as the key to unlocking the latent heat stored in the CG-thickened erythritol, showing its great potential to serve as a high-performance, eco-friendly PCM for long-term seasonal solar energy storage.

Efficient and scalable synthesis of 3,4-dihydroisoquinolin-1(2H)-ones by benzylic oxidation of tetrahydroisoquinoline derivatives using cerium ammonium nitrate (CAN).

An efficient and scalable method for the synthesis of 3,4-dihydroisoquinolin-1(2H)-ones through benzylic oxidation of tetrahydroisoquinoline derivatives using a catalytic amount of cerium ammonium nitrate (CAN) and a stoichiometric amount of NaBrO3 as oxidants was developed. The reaction is significantly influenced by the substituent groups on the phenyl ring. While electron-withdrawing groups on the phenyl ring can lower the reactivities of the substrates, electron-donating groups on the phenyl ring can dramatically promote the oxidation rate.

Spatial heterogeneity of neo- and paleo-endemism for plants in Madagascar.

Madagascar is a biogeographically unique island with a remarkably high level of endemism. However, endemic taxa in Madagascar are massively threatened due to unprecedented pressures from anthropogenic habitat modification and climate change. A comprehensive phylogeny-based biodiversity evaluation of the island remains lacking. Here, we identify hotspots of taxonomic and phylogenetic plant diversity and neo- and paleo-endemism by generating a novel dated tree of life for the island. The tree is based on unprecedented sampling of 3,950 species (33% of the total known species) and 1,621 genera (93% of the total known genera and 69% of endemic genera) of Malagasy vascular plants. We find that island-endemic genera are concentrated in multiple lineages combining high taxonomic and phylogenetic diversity. Integrating phylogenetic and geographic distribution data, our results reveal that taxon richness and endemism are concentrated in the northern, eastern, and southeastern humid forests. Paleo-endemism centers are concentrated in humid eastern and central regions, whereas neo-endemism centers are concentrated in the dry and spiny forests in western and southern Madagascar. Our statistical analysis of endemic genera in each vegetation region supports a higher proportion of ancient endemic genera in the east but a higher proportion of recent endemic genera in the south and west. Overlaying centers of phylogenetic endemism with protected areas, we identify conservation gaps concentrated in western and southern Madagascar. These gaps should be incorporated into conservation strategies to aid the protection of multiple facets of biodiversity and their benefits to the Malagasy people.

Antimicrobial resistance and its detection in Staphylococcus saprophyticus urinary isolates.

The aim of this study was to describe the antibiotic susceptibility of clinical Staphylococcus saprophyticus isolates collected prospectively from urine specimens over a 2-month period from September to October 2022 at a single centre in Melbourne, Australia. Species identification was performed by MALDI-TOF MS. All isolates underwent phenotypic antibiotic susceptibility testing by disc diffusion using European Committee on Antimicrobial Susceptibility Testing (EUCAST) and Clinical and Laboratory Standards Institute (CLSI) guidelines and VITEK2, and mecA polymerase chain reaction. A total of 302 S. saprophyticus isolates from 298 patients were included in this study. Most specimens (91.1%) were referred by community general practitioners from non-hospitalised patients. Antimicrobial resistance to non-ß-lactam antibiotics was uncommon; trimethoprim susceptibility was 97%; trimethoprim/sulfamethoxazole, 98%; nitrofurantoin, 100%; and ciprofloxacin, 100% (100% ciprofloxacin susceptible, increased exposure by EUCAST breakpoints). Methicillin resistance (by mecA detection) was the most common form of urinary antibiotic resistance at 5.6%. VITEK2 susceptibility testing for methicillin resistance had a poor specificity of 61.8% (95% CI 55.8-67.4%) compared to mecA detection. These findings indicate that empiric antibiotic recommendations of trimethoprim, trimethoprim/sulfamethoxazole, and nitrofurantoin for treatment of urinary S. saprophyticus remain appropriate.

The Sino-Himalayan flora evolved from lowland biomes dominated by tropical floristic elements.

BACKGROUND: The Sino-Himalayan flora harbors highly diverse high-elevation biotas, but our understanding of its evolutionary history in temporal and spatial dimensions is limited. In this study, we integrated a dated phylogenetic tree with comprehensive species distribution data to investigate changes over time and space in floristic elements, including the tropical, Tethys, northern temperate, and East Asian floristic elements, across the entire Sino-Himalaya and its three floristic regions: the Yunnan Plateau, Hengduan Mountains, and East Himalaya regions. RESULTS: Our results revealed that the Sino-Himalayan flora developed from lowland biomes and was predominantly characterized by tropical floristic elements before the collision between the Indian subcontinent and Eurasia during the Early Cenozoic. Subsequently, from the Late Eocene onwards, the uplifts of the Himalaya and Hengduan Mountains transformed the Sino-Himalayan region into a wet and cold plateau, on which harsh and diverse ecological conditions forced the rapid evolution of local angiosperms, giving birth to characteristic taxa adapted to the high altitudes and cold habitat. The percentage of temperate floristic elements increased and exceeded that of tropical floristic elements by the Late Miocene. CONCLUSIONS: The Sino-Himalayan flora underwent four significant formation periods and experienced a considerable increase in endemic genera and species in the Miocene, which remain crucial to the present-day patterns of plant diversity. Our findings support the view that the Sino-Himalayan flora is relatively young but has ancient origins. The three major shifts in the divergence of genera and species during the four formation periods were primarily influenced by the uplifts of the Himalaya and Hengduan Mountains and the onset and intensification of the Asian monsoon system. Additionally, the temporal patterns of floristic elements differed among the three floristic regions of the Sino-Himalaya, indicating that the uplift of the Himalaya and surrounding areas was asynchronous. Compared to the Yunnan Plateau region, the East Himalaya and Hengduan Mountains experienced more recent and drastic uplifts, resulting in highly intricate topography with diverse habitats that promoted the rapid radiation of endemic genera and species in these regions.

Knockdown of Porf-2 restores visual function after optic nerve crush injury.

Retinal ganglion cells (RGCs), the sole output neurons in the eyes, are vulnerable to diverse insults in many pathological conditions, which can lead to permanent vision dysfunction. However, the molecular and cellular mechanisms that contribute to protecting RGCs and their axons from injuries are not completely known. Here, we identify that Porf-2, a member of the Rho GTPase activating protein gene group, is upregulated in RGCs after optic nerve crush. Knockdown of Porf-2 protects RGCs from apoptosis and promotes long-distance optic nerve regeneration after crush injury in both young and aged mice in vivo. In vitro, we find that inhibition of Porf-2 induces axon growth and growth cone formation in retinal explants. Inhibition of Porf-2 provides long-term and post-injury protection to RGCs and eventually promotes the recovery of visual function after crush injury in mice. These findings reveal a neuroprotective impact of the inhibition of Porf-2 on RGC survival and axon regeneration after optic nerve injury, providing a potential therapeutic strategy for vision restoration in patients with traumatic optic neuropathy.

Intravitreal injection of Huperzine A promotes retinal ganglion cells survival and axonal regeneration after optic nerve crush.

Traumatic optic neuropathy (TON) is a condition that causes massive loss of retinal ganglion cells (RGCs) and their axonal fibers, leading to visual insufficiency. Several intrinsic and external factors can limit the regenerative ability of RGC after TON, subsequently resulting in RGC death. Hence, it is important to investigate a potential drug that can protect RGC after TON and enhance its regenerative capacity. Herein, we investigated whether Huperzine A (HupA), extracted from a Chinese herb, has neuroprotective effects and may enhance neuronal regeneration following the optic nerve crush (ONC) model. We compared the three modes of drug delivery and found that intravitreal injection of HupA could promote RGC survival and axonal regeneration after ONC. Mechanistically, HupA exerted its neuroprotective and axonal regenerative effects through the mTOR pathway; these effects could be blocked by rapamycin. To sum up, our findings suggest a promising application of HupA in the clinical treatment of traumatic optic nerve.

A novel anterior nasal swab to detect respiratory viruses: a prospective study of diagnostic accuracy.

Detection of respiratory viruses requires testing of the upper respiratory tract to obtain specimens for analysis. However, nasal and throat swabs can cause discomfort and procedural anxiety in children. Respiratory sampling methods which are accurate and less invasive are needed. We aim to determine the positive and negative percentage agreement of a novel anterior nasal swab (ANS) compared with the combined throat and anterior nasal swab (CTN), the reference standard, for detection of respiratory viruses. Children 5 - 18 years of age presenting to a tertiary paediatric hospital with respiratory symptoms were tested with both swabs in randomised order. Respiratory samples were tested on a multiplex RT-PCR panel. Viral detections, RT-PCR cycle-threshold values and child/parent/clinician experience of the swab were recorded. There were 157 viral detections from 249 participant CTN swabs. In comparison with the CTN, the overall positive and negative percentage agreement of ANS for detection of respiratory viruses was 96.2% (95% CI, 91.8-98.3%) and 99.8% (95% CI, 99.6-99.9%), respectively. The ANS was "extremely comfortable", or only a "little uncomfortable" for 90% of children compared with 48% for CTN. 202 children (84%) rated the ANS as the preferred swab, and 208 (87%) indicated they would prefer ANS for future testing. The ANS required additional laboratory handling processes compared to the CTN. The ANS has high positive percentage agreement and is comparable to the current standard of care. The high acceptability from the less invasive ANS provides a more comfortable method for respiratory virus testing in children.Trial registrationClinicalTrials.gov ID NCT05043623.

Default mode network overshadow executive control network in coma emergence and awakening prediction of patients with sTBI.

OBJECTIVE: We aimed to explore the pathogenesis of traumatic coma related to functional connectivity (FC) within the default mode network (DMN), within the executive control network (ECN) and between the DMN and ECN and to investigate its capacity for predicting awakening. METHODS: We carried out resting-state functional magnetic resonance imaging (fMRI) examinations on 28 traumatic coma patients and 28 age-matched healthy controls. DMN and ECN nodes were split into regions of interest (ROIs), and node-to-node FC analysis was conducted on individual participants. To identify coma pathogenesis, we compared the pairwise FC differences between coma patients and healthy controls. Meanwhile, we divided the traumatic coma patients into different subgroups based on their clinical outcome scores at 6 months postinjury. Considering the awakening prediction, we calculated the area under the curve (AUC) to evaluate the predictive ability of changed FC pairs. RESULTS: We found a massive pairwise FC alteration in the patients with traumatic coma compared to the healthy controls [45% (33/74) pairwise FC located in the DMN, 27% (20/74) pairwise FC located in the ECN, and 28% (21/74) pairwise FC located between the DMN and ECN]. Moreover, in the awake and coma groups, there were 67% (12/18) pairwise FC alterations located in the DMN and 33% (6/18) pairwise FC alterations located between the DMN and ECN. We also indicated that pairwise FC that showed a predictive value of 6-month awakening was mainly located in the DMN rather than in the ECN. Specifically, decreased FC between the right superior frontal gyrus and right parahippocampal gyrus (in the DMN) showed the highest predictive ability (AUC = 0.827). CONCLUSION: In the acute phase of severe traumatic brain injury (sTBI), the DMN plays a more prominent role than the ECN and the DMN-ECN interaction in the emergence of traumatic coma and the prediction of 6-month awakening.

Clinical and Health System Impact of Biofire Filmarray Meningitis/Encephalitis Routine Testing of CSF in a Pediatric Hospital: An Observational Study.

BACKGROUND: Rapid cartridge-based molecular test panels targeting multiple pathogens are increasingly available, improve pathogen detection and reduce turn-around-time but are more expensive than standard testing. Confirmation that these test panels contribute to improved patient or health service outcomes is required. METHODS: In March 2021, our pediatric hospital laboratory implemented the BioFire Filmarray™ meningitis/encephalitis (M/E) panel as an additional routine test for all cerebrospinal fluid (CSF) samples collected from infants <90 days or from any patient in the emergency department. A retrospective chart review was done to ascertain changes in clinical outcomes, antimicrobial prescribing practices, and hospital length of stay, comparing two discrete 6-month periods: preimplementation (March-August 2019) and postimplementation (March-August 2021). RESULTS: Both pre- and postimplementation groups were similar at baseline, except the preimplementation group had a higher proportion of infants with enterovirus and parechovirus meningitis. There was no significant difference between the groups in terms of median length of stay (2.94 vs 3.47 days, p = 0.41), duration of antibiotic treatment (2.0 vs 2.3 days, p = 0.25), need for central venous access (12.9% vs 17%, p = 0.38) or hospital-in-the-home admission (9.4% vs 9%, p = 0.92). A similar proportion of infants received aciclovir (33% vs 31%), however, a reduction in duration was observed (1.36 vs 0.90 days, p = 0.03) in the postimplementation period. CONCLUSIONS: Introduction of the Biofire Filmarray™ M/E panel for routine testing of CSF samples reduced the duration of antiviral prescribing but had only a minor impact on antibiotic prescribing practices or health service outcomes in our pediatric hospital. The introduction of new laboratory testing needs to be supported by a comprehensive stewardship program to see optimal outcomes from new testing platforms.

Stick with the nose Saliva rapid antigen testing is not a viable method for testing children under 5 years old.

AIM: Respiratory testing with rapid antigen tests (RATs) in children under 5 years of age may be uncomfortable and presents specific challenges to testing due to compliance and procedural distress. The aim of this study was to investigate sensitivity and feasibility of self-collected nasal and saliva RAT tests compared with a combined nose and throat (CTN) swab PCR in children under 5. METHODS: Children aged between 1 month and 5 years, with confirmed COVID-19 or who were a household contact within 7 days were included. A saliva RAT, nasal RAT and CTN swab were collected by the parent. SARS-CoV-2 cycle threshold (Ct) values for CTN tested by PCR were compared with saliva and nasal RAT results. Parent preference for method of sample was recorded. RESULTS: Forty-one children were recruited with median age of 1.5 (interquartile range 0.7-4.0) years. Only 22/41 (54%) of parents were able to successfully collect a saliva RAT from their child. Sensitivity of the nasal RAT and saliva RAT was 0.889 (95% confidence interval (CI) 0.739-0.969) and 0.158 (95% CI 0.034-0.396), respectively. Upper limit of nasal RAT detection by CTN Ct value was higher than saliva (36.05 vs. 27.29). While saliva RAT was rated most comfortable, nasal RAT was rated the preferred specimen by parents for future testing, due to saliva collection difficulties and time taken. CONCLUSIONS: Rapid antigen testing with nasal RAT is a more feasible and sensitive method for SARS-CoV-2 detection in young children compared with saliva RAT.

Reaction Mechanism and Selectivity Tuning of Propene Oxidation at the Electrochemical Interface.

Electrochemical conversion of propene is a promising technique for manufacturing commodity chemicals by using renewable electricity. To achieve this goal, we still need to develop high-performance electrocatalysts for propene electrooxidation, which highly relies on understanding the reaction mechanism at the molecular level. Although the propene oxidation mechanism has been well investigated at the solid/gas interface under thermocatalytic conditions, it still remains elusive at the solid/liquid interface under an electrochemical environment. Here, we report the mechanistic studies of propene electrooxidation on PdO/C and Pd/C catalysts, considering that the Pd-based catalyst is one of the most promising electrocatalytic systems. By electrochemical in situ attenuated total reflection Fourier transform infrared spectroscopy, a distinct reaction pathway was observed compared with conventional thermocatalysis, emphasizing that propene can be dehydrogenated at a potential higher than 0.80 V, and strongly adsorb via µ-C═CHCH3 and µ3-η2-C═CHCH3 configuration on PdO and Pd, respectively. The µ-C═CHCH3 is via bridge bonds on adjacent Pd and O atoms on PdO, and it can be further oxidized by directly taking surface oxygen from PdO, verified by the H218O isotope-edited experiment. A high surface oxygen content on PdO/C results in a 3 times higher turnover frequency than that on Pd/C for converting propene into propene glycol. This finding highlights the different reaction pathways under an electrochemical environment, which sheds light on designing next-generation electrocatalysts for propene electrooxidation.

Comparable antigen-specific T cell responses in vaccinees with diverse humoral immune responses after the primary and booster BBIBP-CorV vaccination.

BBIBP-CorV exerts efficient protection against SARS-CoV-2 infection. However, waning vaccine-induced humoral immune responses after two-dose vaccination have significantly undermined durable immuno-protection. In this study, we have demonstrated that although anti-spike (S) antibody responses in BBIBP-CorV vaccinees exhibited three serotypes after 6 months, including de novo sero-negative, sero-positive, and sero-decay features, S-specific interferon-γ release as well as Th1 cytokine production in CD4+ and CD8+ T cells were comparable, especially in vaccinees without detectable neutralizing antibodies. Notably, regardless of dramatic increases in humoral immunity after booster vaccination, T cell responses targeting S protein from either wild type or Omicron remained stable before and after booster vaccination in all three serotype vaccinees. No severe cases were observed even in the sero-decay group during the Omicron epidemic in Shanghai. Our results thus illustrate that unlike fluctuating humoral responses, viral-specific T cell responses are extremely stable after booster vaccination. Sustained T cell responses might be dedicated to the rapid restoration of antibody responses after booster vaccination.

Development of a fully automatic separation system coupled with online ICP-MS for measuring rare earth elements in seawater.

Rare earth elements (REEs) are useful geological indicators of marine geochemistry. However, extremely low concentrations (sub-ng L-1) and high-salt matrices result in inefficient measurements. A fully automatic separation system (ELSPE-2 Precon) is used in the online determination of ultra-trace REEs in seawater using inductively coupled plasma mass spectrometry. This system mainly comprises three sections: (i) an auto-sampler (eas-2A) with 120 positions; (ii) a poly(styrene-divinylbenzene) resin column (Prin-Cen Col007) with iminodiacetic and ethylenediaminetriacetic acid functional groups to eliminate the high-salt matrix (e.g., Na, Ca, K, Mg, Al, Ba, Fe, Sr, P, and S) and preserve the target REEs; and (iii) a Trp002 cleanup column for the reduction of the reagent and procedural blank values. The detection limits (3σ) were in the range 0.002 (Dy)-0.097 ng L-1 (La), and the long-term reproducibility (8 h) was between 80% and 120% for all REEs in a 3.5% NaCl matrix solution. The accuracy of this method was verified using a seawater reference material (NASS-6), and the measured REE concentrations were consistent with those previously reported. The proposed online system was used to investigate coastal water samples with varying salinities from the Pearl River Estuary (Guangdong, China). Variations in the REE distribution patterns of different layers of seawater were observed, which could be due to the mixing of potentially light rare earth element-enriched bottom seawater. Moreover, a positive Gd anomaly in river water and seawater might be attributed to anthropogenic pollution from hospitals and the pharmaceutical industry.

Less invasive SARS-CoV-2 testing for children: A comparison of saliva and a novel Anterior Nasal Swab

Reducing procedural discomfort for children requiring respiratory testing for SARS-CoV-2 is important in supporting testing strategies for case identification. Alternative sampling methods to nose and throat swabs, which can be self-collected, may reduce laboratory-based testing requirements and provide rapid results for clearance to attend school or hospital settings. The aim of this study was to compare preference and diagnostic sensitivity of a novel anterior nasal swab (ANS), and saliva, with a standard combined nose and throat (CTN) swab. The three samples were self-collected by children aged 5-18 years who had COVID-19 or were a household close contact. Samples were analysed by reverse transcription polymerase chain reaction (RT-PCR) on the Allplex SARS-CoV-2 Assay. Most children and parents preferred the ANS and saliva swab over the CTN swab for future testing. The ANS was highly sensitive (sensitivity 1.000 (95% Confidence Interval (CI) 0.920, 1.000)) for SARS-CoV-2 detection, compared to saliva (sensitivity 0.886, 95% CI 0.754, 0.962). We conclude the novel ANS is a highly sensitive and more comfortable method for SARS-CoV-2 detection when compared to CTN swab.

Virology and immune dynamics reveal high household transmission of ancestral SARS-CoV-2 strain.

BACKGROUND: Household studies are crucial for understanding the transmission of SARS-CoV-2 infection, which may be underestimated from PCR testing of respiratory samples alone. We aim to combine the assessment of household mitigation measures; nasopharyngeal, saliva, and stool PCR testing; along with mucosal and systemic SARS-CoV-2-specific antibodies, to comprehensively characterize SARS-CoV-2 infection and transmission in households. METHODS: Between March and September 2020, we obtained samples from 92 participants in 26 households in Melbourne, Australia, in a 4-week period following the onset of infection with ancestral SARS-CoV-2 variants. RESULTS: The secondary attack rate was 36% (24/66) when using nasopharyngeal swab (NPS) PCR positivity alone. However, when respiratory and nonrespiratory samples were combined with antibody responses in blood and saliva, the secondary attack rate was 76% (50/66). SARS-CoV-2 viral load of the index case and household isolation measures were key factors that determine secondary transmission. In 27% (7/26) of households, all family members tested positive by NPS for SARS-CoV-2 and were characterized by lower respiratory Ct values than low transmission families (Median 22.62 vs. 32.91; IQR 17.06-28.67 vs. 30.37-34.24). High transmission families were associated with enhanced plasma antibody responses to multiple SARS-CoV-2 antigens and the presence of neutralizing antibodies. Three distinguishing saliva SARS-CoV-2 antibody features were identified according to age (IgA1 to Spike 1, IgA1 to nucleocapsid protein (NP)), suggesting that adults and children generate distinct mucosal antibody responses during the acute phase of infection. CONCLUSION: Utilizing respiratory and nonrespiratory PCR testing, along with the measurement of SARS-CoV-2-specific local and systemic antibodies, provides a more accurate assessment of infection within households and highlights some of the immunological differences in response between children and adults.

Prognostic Value of Different Computed Tomography Scoring Systems in Patients With Severe Traumatic Brain Injury Undergoing Decompressive Craniectomy.

OBJECTIVE: In this study, we investigate the preoperative and postoperative computed tomography (CT) scores in severe traumatic brain injury (TBI) patients undergoing decompressive craniectomy (DC) and compare their predictive accuracy. METHODS: Univariate and multivariate logistic regression analyses were used to determine the relationship between CT score (preoperative and postoperative) and mortality at 30 days after injury. The discriminatory power of preoperative and postoperative CT score was assessed by the area under the receiver operating characteristic curve (AUC). RESULTS: Multivariate logistic regression analysis adjusted for the established predictors of TBI outcomes showed that preoperative Rotterdam CT score (odds ratio [OR], 3.60; 95% confidence interval [CI], 1.13-11.50; P = 0.030), postoperative Rotterdam CT score (OR, 4.17; 95% CI, 1.63-10.66; P = 0.003), preoperative Stockholm CT score (OR, 3.41; 95% CI, 1.42-8.18; P = 0.006), postoperative Stockholm CT score (OR, 4.50; 95% CI, 1.60-12.64; P = 0.004), preoperative Helsinki CT score (OR, 1.44; 95% CI, 1.03-2.02; P = 0.031), and postoperative Helsinki CT score (OR, 2.55; 95% CI, 1.32-4.95; P = 0.005) were significantly associated with mortality. The performance of the postoperative Rotterdam CT score was superior to the preoperative Rotterdam CT score (AUC, 0.82-0.97 vs 0.71-0.91). The postoperative Stockholm CT score was superior to the preoperative Stockholm CT score (AUC, 0.76-0.94 vs 0.72-0.92). The postoperative Helsinki CT score was superior to the preoperative Helsinki CT score (AUC, 0.88-0.99 vs 0.65-0.87). CONCLUSIONS: In conclusion, assessing the CT score before and after DC may be more precise and efficient for predicting early mortality in severe TBI patients who undergo DC.

High CO-Tolerant Ru-Based Catalysts by Constructing an Oxide Blocking Layer.

CO poisoning of Pt-group metal catalysts is a long-standing problem, particularly for hydrogen oxidation reaction in proton exchange membrane fuel cells. Here, we report a catalyst of Ru oxide-coated Ru supported on TiO2 (Ru@RuO2/TiO2), which can tolerate 1-3% CO, enhanced by about 2 orders of magnitude over the classic PtRu/C catalyst, for hydrogen electrooxidation in a rotating disk electrode test. This catalyst can work stably in 1% CO/H2 for 50 h. About 20% of active sites can survive even in a pure CO environment. The high CO tolerance is not via a traditional bifunctional mechanism, i.e., oxide promoting CO oxidation, but rather via hydrous metal oxide shell blocking CO adsorption. An ab initio molecular dynamics (AIMD) simulation indicates that water confined in grain boundaries of the Ru oxide layer and Ru surface can suppress the diffusion and adsorption of CO. This oxide blocking layer approach opens a promising avenue for the design of high CO-tolerant electrocatalysts for fuel cells.

Water-Soluble Polysaccharides Extracted from Pueraria lobata Delay Aging of Caenorhabditis elegans under Heat Stress.

Pueraria lobata is a perennial legume, commonly used as a food source in China. The polysaccharides extracted from P. lobata have demonstrated various biological activities. However their anti-aging effects and the underline mechanisms are largely unknown. In this study, water-soluble polysaccharides (WSPS) from P. lobata were extracted and demonstrated antioxidant activity against DPPH radicals and hydroxyl radicals in vitro. Using nematode Caenorhabditis elegans as a model, we found that WSPS remarkably prolonged the survival, increased growth and locomotion under heat stress. To investigate the possible mechanism, the levels of reactive oxygen species (ROS) and lipid peroxidation product malondialdehyde (MDA) were determined. WSPS significantly decreased ROS and MDA levels which is consistent with increased activity of superoxide dismutase (SOD). Meanwhile, WSPS upregulated the expression of stress resistance genes sod-1, sod-5, hsf-1, hsp-12.6, hsp-16.2, skn-1 and gst-4. Together, these results suggest that the anti-aging activity of WSPS under heat stress was mediated most likely by activation of the target genes of heat-shock transcription factor (HSF)-1 and skinhead (SKN)-1, and thus inducing endogenous ROS scavenging response.

Gestational Leucylation Suppresses Embryonic T-Box Transcription Factor 5 Signal and Causes Congenital Heart Disease.

Dysregulated maternal nutrition, such as vitamin deficiencies and excessive levels of glucose and fatty acids, increases the risk for congenital heart disease (CHD) in the offspring. However, the association between maternal amino-acid levels and CHD is unclear. Here, it is shown that increased leucine levels in maternal plasma during the first trimester are associated with elevated CHD risk in the offspring. High levels of maternal leucine increase embryonic lysine-leucylation (K-Leu), which is catalyzed by leucyl-tRNA synthetase (LARS). LARS preferentially binds to and catalyzes K-Leu modification of lysine 339 within T-box transcription factor TBX5, whereas SIRT3 removes K-Leu from TBX5. Reversible leucylation retains TBX5 in the cytoplasm and inhibits its transcriptional activity. Increasing embryonic K-Leu levels in high-leucine-diet fed or Sirt3 knockout mice causes CHD in the offspring. Targeting K-Leu using the leucine analogue leucinol can inhibit LARS activity, reverse TBX5 K-Leu modification, and decrease the occurrence of CHD in high-leucine-diet fed mice. This study reveals that increased maternal leucine levels increases CHD risk in the offspring through inhibition of embryonic TBX5 signaling, indicating that leucylation exerts teratogenic effects during heart development and may be an intervening target of CHD.