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This study presents an investigation of the isotropic superconductor Ti4Ir2O, focusing on its magnetic field vs. temperature phase diagram near and above the Pauli limit for superconductivity. The data exhibits characteristic features that align with the formation of a Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) state, including a deviation of the upper critical field line from the standard WHH model upon approaching the Pauli limiting field and a phase transition line separating the ordinary low-field superconducting phase from an unusual high field superconducting state above the Pauli limit. We discuss why the upper critical field line in this isotropic superconductor can approach the Pauli limit, necessitating a particularly high orbital limit for superconductivity. The research also identifies peculiar features in the specific heat data set taken at 0.6 K, which may be an example of the segmentation of the FFLO phase with multiple q phases. The findings provide an explanation for the violation of the Pauli limit in this superconductor, adding a fully isotropic superconductor to the list of potential FFLO superconductors and providing new insights for contemporary theories of the FFLO state.

In this work, ~100 nm wide quantum anomalous Hall insulator (QAHI) nanoribbons are etched from a two-dimensional QAHI film. One part of the nanoribbon is covered with superconducting Nb, while the other part is connected to an Au lead via two-dimensional QAHI regions. Andreev reflection spectroscopy measurements were performed, and multiple in-gap conductance peaks were observed in three different devices. In the presence of an increasing magnetic field perpendicular to the QAHI film, the multiple in-gap peak structure evolves into a single zero-bias conductance peak (ZBCP). Theoretical simulations suggest that the measurements are consistent with the scenario that the increasing magnetic field drives the nanoribbons from a multi-channel occupied regime to a single channel occupied regime, and that the ZBCP may be induced by zero energy Majorana modes as previously predicted [24]. Although further experiments are needed to clarify the nature of the ZBCP, we provide initial evidence that quasi-1D QAHI nanoribbon/superconductor heterostructures are new and promising platforms for realizing zero-energy Majorana modes.

We have fabricated three-dimensional (3D) networks of ultrathin carbon nanotubes (CNTs) within the ~5-Angstrom diameter pores of zeolite ZSM-5 crystals using the chemical vapour deposition (CVD) process. The 1D electronic characteristics of ultrathin CNTs are characterized by van Hove singularities in the density of states. Boron doping was strategically employed to tune the Fermi energy near a van Hove singularity, which is supported by extensive ab-initio calculations, while the 3D network structure ensures the formation of a phase-coherent bulk superconducting state under a 1D to 3D crossover. We report characteristic signatures of superconductivity using four complementary experimental methods: magnetization, specific heat, resistivity, and point-contact spectroscopy, all consistently support a critical temperature Tc at ambient conditions ranging from 220 to 250 K. In particular, point-contact spectroscopy revealed a multigap nature of superconductivity with a large ~30 meV leading gap, in rough agreement with the prediction of the Bardeen-Cooper-Schrieffer (BCS) theory of superconductivity. The differential conductance response displays a particle-hole symmetry and is tuneable between the tunnelling and Andreev limits via the transparency of the contact, as uniquely expected for a superconductor. Preliminary experiments also reveal a giant pressure effect which increases the Tc above the ambient temperature.

We report on the discovery, structural analysis, and the physical properties of Nb\\(_4\\)SiSb\\(_2\\) -- a hitherto unknown compound crystallizing in the V\\(_4\\)SiSb\\(_2\\)-type structure with the tetragonal space group \\(I4/mcm\\) and unit cell parameters \\(a\\) = 10.3638(2) \\(A\\) and \\(c\\) = 4.9151(2) \\(A\\). We find Nb\\(_4\\)SiSb\\(_2\\) to be a metal undergoing a transition to a superconducting state at a critical temperature of \\(T_ c \\) 1.6 K. The bulk nature of the superconductivity in this material is confirmed by the observation of a well defined discontinuity in specific heat with a normalized specific heat jump of \\( C(T_ c)/ T_ c = 1.33\\, mJ\\, mol^-1\\, K^-2\\). We find that for Nb\\(_4\\)SiSb\\(_2\\), the unoccupied sites on the \\(4b\\) Wyckoff position can be partially occupied with Cu, Pd, or Pt. Low-temperature resistivity measurements show transitions to superconductivity for all three compounds at \\(T_ c \\, 1.2\\, K\\) for Nb\\(_4\\)Cu\\(_0.2\\)SiSb\\(_2\\), and \\(T_ c \\, 0.8\\, K\\) for Nb\\(_4\\)Pd\\(_0.2\\)SiSb\\(_2\\) as well as for Nb\\(_4\\)Pt\\(_0.14\\)SiSb\\(_2\\). The addition of electron-donor atoms into these void positions, henceforth, lowers the superconducting transition temperature in comparison to the parent compound.

Antibiotic tolerance poses a threat to current antimicrobial armamentarium. Bacteria at a tolerant state survive in the presence of antibiotic treatment and account for persistence, relapse and recalcitrance of infections. Antibiotic treatment failure may occur due to antibiotic tolerance. Persistent infections are difficult to treat and are often associated with poor prognosis, imposing an enormous burden on the healthcare system. Effective strategies targeting antibiotic-tolerant bacteria are therefore highly warranted. In this study, small molecule compound SA-558 was identified to be effective against Staphylococcus aureus that are tolerant to being killed by conventional antibiotics. SA-558 mediated electroneutral transport across the membrane and led to increased ATP and ROS generation, resulting in a reduction of the population of antibiotic-tolerant bacteria. In a murine chronic infection model, of which vancomycin treatment failed, we demonstrated that SA-558 alone and in combination with vancomycin caused significant reduction of MRSA abundance. Our results indicate that SA-558 monotherapy or combinatorial therapy with vancomycin is an option for managing persistent S. aureus bacteremia infection and corroborate that bacterial metabolism is an important target for counteracting antibiotic tolerance.

During the investigation of a pet shop outbreak of severe acute respiratory coronavirus 2 (SARS-CoV-2) with probable hamster-to-human transmission, the environmental and hamster samples in epidemiologically linked pet shops were found positive for SARS-CoV-2 Delta variant AY.127 strains which are phylogenetically closely related to patients and reported European strains. This interspecies' spill-over has triggered transmission in 58 patients epidemiologically linked to three pet shops. Incidentally, three dwarf hamsters imported from the Netherlands and centralized in a warehouse distributing animals to pet shops were positive for SARS-CoV-2 spike variant phylogenetically related to European B.1.258 strains from March 2020. This B.1.258 strain almost disappeared in July 2021. While no hamster-to-human transmission of B.1.258-like strain was found in this outbreak, molecular docking showed that its spike receptor-binding domain (RBD) has a similar binding energy to human ACE2 compared to that of Delta variant AY.127. Therefore, the potential of this B.1.258-related spike variant for interspecies jumping cannot be ignored. The co-circulation of B.1.258-related spike variants with Delta AY.127, which originated in Europe and was not previously found in Hong Kong, suggested that hamsters in our wholesale warehouse and retail pet shops more likely have acquired these viruses in the Netherlands or stopovers during delivery by aviation than locally. The risk of human-to-hamster reverse zoonosis by multiple SARS-CoV-2 variants leading to further adaptive spike mutations with subsequent transmission back to humans cannot be underestimated as an outbreak source of COVID-19. Testing imported pet animals susceptible to SARS-CoV-2 is warranted to prevent future outbreaks.

ObjectiveCognitive stimulation (CS) is a non-pharmacological intervention aimed at enhancing cognitive function. However, the effectiveness of CS in individuals diagnosed with mild cognitive impairment (MCI) remains inconclusive. Therefore, this study aimed to assess the effectiveness of CS in improving cognitive function, psychological well-being, instrumental activities of daily living (IADL) and quality of life (QoL) in individuals with MCI, based on randomised controlled trials (RCTs).DesignSystematic review and meta-analysis.Data sourcesSix English databases were systematically searched, including PubMed, Web of Science, Embase, Cumulative Index to Nursing and Allied Health Literature, American Psychological Association PsycInfo and Academic Search Premier.Eligibility criteriaRCTs about CS for individuals with MCI, published between January 2003 and December 2024.Data extraction and synthesisData were extracted and assessed using the revised Cochrane risk of bias tool for randomised trials by independent researchers. The meta-analysis was conducted using the standardised mean difference (SMD) and 95% CIs of the included studies.ResultsThe meta-analysis included five eligible studies for the primary outcomes of cognitive function and three eligible studies for the secondary outcomes of psychological wellness. In the pooled samples, the CS intervention had a significant effect on cognitive function (SMD=0.63, 95% CI 0.25 to 1.01; p=0.001) and depression symptoms (SMD=−0.29, 95% CI −0.55 to −0.03; p=0.03) in individuals with MCI. However, no significant improvements in anxiety symptoms were identified after the CS intervention (SMD=−0.05; 95% CI −0.31 to 0.21; p=0.71).ConclusionThe CS intervention can effectively improve cognitive function and alleviate depression symptoms. Although a meta-analysis was not conducted for IADL and QoL due to the limited number of included studies, positive trends in enhancing IADL performance and augmenting QoL were observed in individuals with MCI. However, due to the scarcity of relevant studies in this research field, more comprehensive RCTs are warranted to provide a better understanding of the potential benefits of CS and to guide its clinical application in the future.PROSPERO registration numberCRD42023494685.

Carotenoids and vitamin A are nutrients crucial to infants’ development. To date, there is limited data on their availability in breastmilk and the associated dietary factors, especially in Hong Kong, where people follow a westernized Chinese diet. This study determined the selected breastmilk’s carotenoid and vitamin A (retinol) contents by ultraperformance liquid chromatography with photodiode detection (UPLC-PDA) and the dietary intakes by three-day food records in 87 Hong Kong lactating mothers, who were grouped into tertiles based on their daily carotenoid intake. Low vitamin A intake (530.2 ± 34.2 µg RAE/day) and breastmilk retinol level (1013.4 ± 36.8 nmol/L) were reported in our participants, suggesting a poor vitamin A status of the lactating participants having relatively higher socioeconomic status in Hong Kong. Mothers in the highest tertile (T3) had higher breastmilk carotenoid levels than those in the lowest (T1) (p < 0.05). There were significant associations between maternal carotenoid intakes and breastmilk lutein levels in the linear regression models (p < 0.05) regardless of dietary supplement intake. Furthermore, maternal dark green vegetable intakes were associated with breastmilk retinol, lutein, and β-carotene levels. These findings can serve as dietary references for lactating mothers to enhance breastmilk carotenoid and vitamin A contents for the benefits of child growth and development.

There is insufficient understanding on systemic interferon (IFN) responses during COVID-19 infection. Early reports indicated that interferon responses were suppressed by the coronavirus (SARS-CoV-2) and clinical trials of administration of various kinds of interferons had been disappointing. Expression of interferon-stimulated genes (ISGs) in peripheral blood (better known as interferon score) has been a well-established bioassay marker of systemic IFN responses in autoimmune diseases. Therefore, with archival samples of a cohort of COVID-19 patients collected before the availability of vaccination, we aimed to better understand this innate immune response by studying the IFN score and related ISGs expression in bulk and single cell RNAs sequencing expression datasets. In this study, we recruited 105 patients with COVID-19 and 30 healthy controls in Hong Kong. Clinical risk factors, disease course, and blood sampling times were recovered. Based on a set of five commonly used ISGs (IFIT1, IFIT2, IFI27, SIGLEC1, IFI44L), the IFN score was determined in blood leukocytes collected within 10 days after onset. The analysis was confined to those blood samples collected within 10 days after disease onset. Additional public datasets of bulk gene and single cell RNA sequencing of blood samples were used for the validation of IFN score results. Compared to the healthy controls, we showed that ISGs expression and IFN score were significantly increased during the first 10 days after COVID infection in majority of patients (71%). Among those low IFN responders, they were more commonly asymptomatic patients (71% vs 25%). 22 patients did not mount an overall significant IFN response and were classified as low IFN responders (IFN score < 1). However, early IFN score or ISGs level was not a prognostic biomarker and could not predict subsequent disease severity. Both IFI27 and SIGLEC1 were monocyte-predominant expressing ISGs and IFI27 were activated even among those low IFN responders as defined by IFN score. In conclusion, a substantial IFN response was documented in this cohort of COVID-19 patients who experience a natural infection before the vaccination era. Like innate immunity towards other virus, the ISGs activation was observed largely during the early course of infection (before day 10). Single-cell RNA sequencing data suggested monocytes were the cell-type that primarily accounted for the activation of two highly responsive ISGs (IFI44L and IFI27). As sampling time and age were two major confounders of ISG expression, they may account for contradicting observations among previous studies. On the other hand, the IFN score was not associated with the severity of the disease.

Antibiotic tolerance poses a threat to current antimicrobial armamentarium. Bacteria at a tolerant state survive in the presence of antibiotic treatment and account for persistence, relapse and recalcitrance of infections. Antibiotic treatment failure may occur due to antibiotic tolerance. Persistent infections are difficult to treat and are often associated with poor prognosis, imposing an enormous burden on the healthcare system. Effective strategies targeting antibiotic-tolerant bacteria are therefore highly warranted. In this study, small molecule compound SA-558 was identified to be effective against Staphylococcus aureus that are tolerant to being killed by conventional antibiotics. SA-558 mediated electroneutral transport across the membrane and led to increased ATP and ROS generation, resulting in a reduction of the population of antibiotic-tolerant bacteria. In a murine chronic infection model, of which vancomycin treatment failed, we demonstrated that SA-558 alone and in combination with vancomycin caused significant reduction of MRSA abundance. Our results indicate that SA-558 monotherapy or combinatorial therapy with vancomycin is an option for managing persistent S. aureus bacteremia infection and corroborate that bacterial metabolism is an important target for counteracting antibiotic tolerance.