Evidence for d-wave superconductivity of infinite-layer nickelates from low-energy electrodynamics.

The discovery of superconductivity in infinite-layer nickelates established another category of unconventional superconductors that shares structural and electronic similarities with cuprates. However, key issues of the superconducting pairing symmetry, gap amplitude and superconducting fluctuations are yet to be addressed. Here we utilize static and ultrafast terahertz spectroscopy to address these. We demonstrate that the equilibrium terahertz conductivity and non-equilibrium terahertz responses of an optimally Sr-doped nickelate film (superconducting transition temperature of Tc = 17 K) are in line with the electrodynamics of d-wave superconductivity in the dirty limit. The gap-to-Tc ratio (2Δ/kBTc) is found to be 3.4, indicating that the superconductivity falls in the weak coupling regime. In addition, we observed substantial superconducting fluctuations near Tc that do not extend into the deep normal state as the optimally hole-doped cuprates do. Our results support a d-wave system that closely resembles the electron-doped cuprates.

Differentiated roles of Lifshitz transition on thermodynamics and superconductivity in La2-xSrxCuO4.

The effect of Lifshitz transition on thermodynamics and superconductivity in hole-doped cuprates has been heavily debated but remains an open question. In particular, an observed peak of electronic specific heat is proposed to originate from fluctuations of a putative quantum critical point p* (e.g., the termination of pseudogap at zero temperature), which is close to but distinguishable from the Lifshitz transition in overdoped La-based cuprates where the Fermi surface transforms from hole-like to electron-like. Here we report an in situ angle-resolved photoemission spectroscopy study of three-dimensional Fermi surfaces in La2-xSrxCuO4 thin films (x = 0.06 to 0.35). With accurate kz dispersion quantification, the said Lifshitz transition is determined to happen within a finite range around x = 0.21. Normal state electronic specific heat, calculated from spectroscopy-derived band parameters, reveals a doping-dependent profile with a maximum at x = 0.21 that agrees with previous thermodynamic microcalorimetry measurements. The account of the specific heat maximum by underlying band structures excludes the need for additionally dominant contribution from the quantum fluctuations at p*. A d-wave superconducting gap smoothly across the Lifshitz transition demonstrates the insensitivity of superconductivity to the dramatic density of states enhancement.

Study on the spatiotemporal distribution of algal blooms and its influencing factors in young reservoirs based on remote sensing interpretation.

Algal blooms caused by excessive proliferation of phytoplankton in young reservoirs have been frequently reported, seriously threatening the unstable aquatic ecosystem, water quality safety and public health. Thus, there is an urgent need to investigate the dynamics of phytoplankton in these young reservoirs, and many current studies on phytoplankton in young reservoirs are based on point monitoring information. This study used remote sensing interpretation to invert the chlorophyll-a concentration in 131 images of Zipingpu Reservoir from 2013 to 2021, and analyzed the spatiotemporal characteristics of algal blooms. Partial least squares-structural equation modeling was used to identify the environmental influencing factors of algal blooms. The results showed that the average chlorophyll-a concentration in the reservoir was 4.49 mg/m3, and the frequency of algal blooms was 28%. The maximum area of algal blooms shows a significant increase trend in the interannual (increase by 0.05%/yr in the proportion of water surface area), and the average blooms area shows a weaker increase trend (0.01%/yr). The prone period of algal bloom is from April to August every year. The solar duration and wind speed had significant direct positive effects on the maximum and average algal bloom area, which was the similar effects in different years and months (path coefficient exceeds 0.44). TP also has a significant direct positive effect on the average algal bloom area between different years (path coefficient of 0.30). The suitable meteorological factors level making the bloom-prone period from April to August, the prevailing westerly and southerly winds provide transport for the aggregation of phytoplankton and algal blooms outbreak in the northeastern waters. This study expand the monitoring frequency and spatial information of algal blooms, which provided a reference for young reservoir management and prevention of blooms.

Mechanism and Application of Surface-Charged Ferrite Nanozyme-Based Biosensor toward Colorimetric Detection of l-Cysteine.

Peroxidase-like nanozymes with robust catalytic capacity and detection specificity have been proposed as substitutes to natural peroxidases in biochemical sensing. However, the catalytic activity enhancement, detection mechanism, and application of nanozyme-based biosensors toward l-cysteine (l-Cys) detection still remain significant challenges. In this work, a doped ferrite nanozyme with well-defined structure and surface charges is fabricated by a two-step method of continuous flow coprecipitation and high-temperature annealing. The resulted ferrite nanozyme possesses an average size of 54.5 nm and a zeta-potential of 6.45 mV. A high-performance biosensor is manufactured based on the peroxidase-like catalytic feature of the doped ferrite. The ferrite nanozyme can oxidize the 3,3',5,5'-tetramethylbenzidine (TMB) with the assistance of H2O2 because of the instinctive capacity to decompose H2O2 into ·OH. The Michaelis-Menten constants (0.0911 mM for TMB, 0.140 mM for H2O2) of the ferrite nanozyme are significantly smaller than those of horseradish peroxidase. A reliable colorimetric method is established to selectively analyze l-Cys via a facile mixing-and-detecting methodology. The detection limit and linear range are 0.119 µM and 0.2-20 µM, respectively. Taking the merits of the ferrite nanozyme-based biosensors, the l-Cys level in the human serum can be qualitatively detected. It can be anticipated that the surface-charged ferrite nanozyme shows great application prospects in the fields of bioanalytical chemistry and point-of-care testing.

Variation in Compositions and Biological Activities of Essential Oils from Four Citrus Species: Citrus limon, Citrus sinensis, Citrus paradisi, and Citrus reticulata.

Species of the genus Citrus are cultivated in many regions of China and are widely used for medicinal purposes. In the present study, essential oils (EOs) were extracted from four different Citrus species using steam distillation. The chemical components of these four essential oils were separated using gas chromatography-mass spectrometry, and 52 compounds were confirmed. D-limonene was found to be the most abundant compound. All four essential oils demonstrated varied but remarkable radical scavenging capacity (IC50 ; 0.77-13.9 %). Citrus paradisi essential oil exhibited excellent antioxidant activity. Compared to ibuprofen, topical application of the four Citrus spp. essential oils significantly inhibited ear edema formation in mice. Furthermore, essential oils from the four Citrus species reduced the expression levels of interleukin-6 (IL-6), cyclooxygenase-2 (COX-2) and nuclear transcription factor kappa B p65 (NF-κB) to different degrees. The cytotoxicity of the four essential oils on BV2 microglial cells was determined using the MTT assay (IC50 ; 321.37-1558.87 µg/mL), wherein Citrus limon essential oil showed the lowest cytotoxicity. The essential oils of Citrus limon, Citrus reticulata, and Citrus paradisi had an inhibitory effect on the lung cancer cell lines H1299 by inducing a G0/G1 cell cycle arrest. Cluster and principal component analyses were used to determine the relationship among the Citrus species. These results suggest that the four Citrus essential oils have potential for use as active ingredients in functional foods or cosmeceutical products.

Stabilization of Sr3Al2O6 Growth Templates for Ex Situ Synthesis of Freestanding Crystalline Oxide Membranes.

A new synthetic approach has recently been developed for the fabrication of freestanding crystalline perovskite oxide nanomembranes, which involves the epitaxial growth of a water-soluble sacrificial layer. By utilizing an ultrathin capping layer of SrTiO3, here we show that this sacrificial layer, as grown by pulsed laser deposition, can be stabilized in air and therefore be used as transferrable templates for ex situ epitaxial growth using other techniques. We find that the stability of these templates depends on the thickness of the capping layer. On these templates, freestanding superconducting SrTiO3 membranes were synthesized ex situ using molecular beam epitaxy, enabled by the lower growth temperature which preserves the sacrificial layer. This study paves the way for the synthesis of an expanded selection of freestanding oxide membranes and heterostructures with a wide variety of ex situ growth techniques.

Prevention of IL-6 signaling ameliorates toluene diisocyanate-induced steroid-resistant asthma.

BACKGROUND: Accumulating evidence indicated the crucial role for interleukin 6 (IL-6) signaling in the development of allergic asthma. Yet, the role of IL-6 signaling in toluene diisocyanate (TDI)-induced mixed granulocytic airway inflammation still remains unclear. Thus, the aims of this study were to dissect the role of IL-6 signaling and to evaluate the effect of tocilizumab on TDI-induced steroid-resistant asthma. METHODS: TDI-induced asthma model was prepared and asthmatic mice were respectively given IL-6 monoclonal antibody, IL-6R monoclonal antibody (tocilizumab, 5 mg/kg, i.p. after each challenge) for therapeutic purposes or isotype IgG as control. RESULTS: TDI exposure just elevated IL-6R expression in the infiltrated inflammatory cells around the airway, but increased glycoprotein 130 expression in the whole lung, especially in bronchial epithelium. Moreover, TDI inhalation increased airway hyperresponsiveness (AHR) to methacholine, coupled with mixed granulocytic inflammation, exaggerated epithelial denudation, airway smooth muscle thickening, goblet cell metaplasia, extensive submucosal collagen deposition, dysregulated Th2/Th17 responses, as well as innate immune responses and raised serum IgE. And almost all these responses except for raised serum IgE were markedly ameliorated by the administration of IL-6 neutralizing antibody or tocilizumab, but exhibited poor response to systemic steroid treatment. Also, TDI challenge induced nucleocytoplasm translocation of HMGB1 and promoted its release in the BALF, as well as elevated lung level of STAT3 phosphorylation, which were inhibited by anti-IL-6 and anti-IL-6R treatment. CONCLUSIONS: Our data suggested that IL-6 monoclonal antibody and tocilizumab might effectively abrogate TDI-induced airway inflammation and remodeling, which could be used as a clinical potential therapy for patients with severe asthma.

Phonon-Mediated Long-Range Attractive Interaction in One-Dimensional Cuprates.

Establishing a minimal microscopic model for cuprates is a key step towards the elucidation of a high-T_{c} mechanism. By a quantitative comparison with a recent in situ angle-resolved photoemission spectroscopy measurement in doped 1D cuprate chains, our simulation identifies a crucial contribution from long-range electron-phonon coupling beyond standard Hubbard models. Using reasonable ranges of coupling strengths and phonon energies, we obtain a strong attractive interaction between neighboring electrons, whose strength is comparable to experimental observations. Nonlocal couplings play a significant role in the mediation of neighboring interactions. Considering the structural and chemical similarity between 1D and 2D cuprate materials, this minimal model with long-range electron-phonon coupling will provide important new insights on cuprate high-T_{c} superconductivity and related quantum phases.

Gate-Induced Interfacial Superconductivity in 1T-SnSe2.

Layered metal chalcogenide materials provide a versatile platform to investigate emergent phenomena and two-dimensional (2D) superconductivity at/near the atomically thin limit. In particular, gate-induced interfacial superconductivity realized by the use of an electric-double-layer transistor (EDLT) has greatly extended the capability to electrically induce superconductivity in oxides, nitrides, and transition metal chalcogenides and enable one to explore new physics, such as the Ising pairing mechanism. Exploiting gate-induced superconductivity in various materials can provide us with additional platforms to understand emergent interfacial superconductivity. Here, we report the discovery of gate-induced 2D superconductivity in layered 1T-SnSe2, a typical member of the main-group metal dichalcogenide (MDC) family, using an EDLT gating geometry. A superconducting transition temperature Tc ≈ 3.9 K was demonstrated at the EDL interface. The 2D nature of the superconductivity therein was further confirmed based on (1) a 2D Tinkham description of the angle-dependent upper critical field Bc2, (2) the existence of a quantum creep state as well as a large ratio of the coherence length to the thickness of superconductivity. Interestingly, the in-plane Bc2 approaching zero temperature was found to be 2-3 times higher than the Pauli limit, which might be related to an electric field-modulated spin-orbit interaction. Such results provide a new perspective to expand the material matrix available for gate-induced 2D superconductivity and the fundamental understanding of interfacial superconductivity.

Imaging and tuning polarity at SrTiO3 domain walls.

Electrostatic fields tune the ground state of interfaces between complex oxide materials. Electronic properties, such as conductivity and superconductivity, can be tuned and then used to create and control circuit elements and gate-defined devices. Here we show that naturally occurring twin boundaries, with properties that are different from their surrounding bulk, can tune the LaAlO3/SrTiO3 interface 2DEG at the nanoscale. In particular, SrTiO3 domain boundaries have the unusual distinction of remaining highly mobile down to low temperatures, and were recently suggested to be polar. Here we apply localized pressure to an individual SrTiO3 twin boundary and detect a change in LaAlO3/SrTiO3 interface current distribution. Our data directly confirm the existence of polarity at the twin boundaries, and demonstrate that they can serve as effective tunable gates. As the location of SrTiO3 domain walls can be controlled using external field stimuli, our findings suggest a novel approach to manipulate SrTiO3-based devices on the nanoscale.

Superconducting Tunneling Spectroscopy of Spin-Orbit Coupling and Orbital Depairing in Nb:SrTiO_{3}.

We have examined the intrinsic spin-orbit coupling and orbital depairing in thin films of Nb-doped SrTiO_{3} by superconducting tunneling spectroscopy. The orbital depairing is geometrically suppressed in the two-dimensional limit, enabling a quantitative evaluation of the Fermi level spin-orbit scattering using Maki's theory. The response of the superconducting gap under in-plane magnetic fields demonstrates short spin-orbit scattering times τ_{so}≤1.1 ps. Analysis of the orbital depairing indicates that the heavy electron band contributes significantly to pairing. These results suggest that the intrinsic spin-orbit scattering time in SrTiO_{3} is comparable to those associated with Rashba effects in SrTiO_{3} interfacial conducting layers and can be considered significant in all forms of superconductivity in SrTiO_{3}.

Serum Levels of TRIM72 Are Lower among Patients with Colon Cancer: Identification of a Potential Diagnostic Marker.

Colon cancer is one of the most common malignancies causing the majority of cancer-related deaths worldwide. The tripartite motif family protein 72 (TRIM72), also known as mitsugumin 53, acts as an E3 ubiquitin ligase. TRIM72 is involved in insulin resistance and metabolic syndrome, which are risk factors of colon cancer. However, the correlation between TRIM72 and colon cancer remains unknown. In the present study, we explored the expression profile of TRIM72 in colon cancer tissues and the diagnostic value of serum TRIM72 in colon cancer. The receiver operating characteristic (ROC) curves were applied for evaluating the diagnostic value of serum TRIM72. We thus found that immunoreactive TRIM72 levels were significantly lower in colon cancer tissues than those in normal colon tissues. Moreover, serum TRIM72 levels were significantly lower in colon cancer patients than those in healthy volunteers. Importantly, the lower serum TRIM72 levels were associated with advanced clinical stage, lymph node, and distant metastases in colon cancer patients. The ROC curve analysis showed that serum TRIM72 has a superior diagnostic value (the area under the curve (AUC) = 0.829) than the traditional tumor biomarkers, carcinoembryonic antigen (CEA) (AUC = 0.707) and carbohydrate antigen 19-9 (CA199) (AUC = 0.750), and the combination of TRIM72 with CEA and CA199 showed the best diagnostic value for colon cancer (AUC = 0.928). In conclusion, serum TRIM72 may be a potential biomarker for the diagnosis and the prognosis of colon cancer.

Dual-Gate Modulation of Carrier Density and Disorder in an Oxide Two-Dimensional Electron System.

Carrier density and disorder are two crucial parameters that control the properties of correlated two-dimensional electron systems. In order to disentangle their individual contributions to quantum phenomena, independent tuning of these two parameters is required. Here, by utilizing a hybrid liquid/solid electric dual-gate geometry acting on the conducting LaAlO3/SrTiO3 heterointerface, we obtain an additional degree of freedom to strongly modify the electron confinement profile and thus the strength of interfacial scattering, independent from the carrier density. A dual-gate controlled nonlinear Hall effect is a direct manifestation of this profile, which can be quantitatively understood by a Poisson-Schrödinger sub-band model. In particular, the large nonlinear dielectric response of SrTiO3 enables a very wide range of tunable density and disorder, far beyond that for conventional semiconductors. Our study provides a broad framework for understanding various reported phenomena at the LaAlO3/SrTiO3 interface.

Direct Imaging of Nanoscale Conductance Evolution in Ion-Gel-Gated Oxide Transistors.

Electrostatic modification of functional materials by electrolytic gating has demonstrated a remarkably wide range of density modulation, a condition crucial for developing novel electronic phases in systems ranging from complex oxides to layered chalcogenides. Yet little is known microscopically when carriers are modulated in electrolyte-gated electric double-layer transistors (EDLTs) due to the technical challenge of imaging the buried electrolyte-semiconductor interface. Here, we demonstrate the real-space mapping of the channel conductance in ZnO EDLTs using a cryogenic microwave impedance microscope. A spin-coated ionic gel layer with typical thicknesses below 50 nm allows us to perform high resolution (on the order of 100 nm) subsurface imaging, while maintaining the capability of inducing the metal-insulator transition under a gate bias. The microwave images vividly show the spatial evolution of channel conductance and its local fluctuations through the transition as well as the uneven conductance distribution established by a large source-drain bias. The unique combination of ultrathin ion-gel gating and microwave imaging offers a new opportunity to study the local transport and mesoscopic electronic properties in EDLTs.

Tunable surface electron spin splitting with electric double-layer transistors based on InN.

Electrically manipulating electron spins based on Rashba spin-orbit coupling (SOC) is a key pathway for applications of spintronics and spin-based quantum computation. Two-dimensional electron systems (2DESs) offer a particularly important SOC platform, where spin polarization can be tuned with an electric field perpendicular to the 2DES. Here, by measuring the tunable circular photogalvanic effect (CPGE), we present a room-temperature electric-field-modulated spin splitting of surface electrons on InN epitaxial thin films that is a good candidate to realize spin injection. The surface band bending and resulting CPGE current are successfully modulated by ionic liquid gating within an electric double-layer transistor configuration. The clear gate voltage dependence of CPGE current indicates that the spin splitting of the surface electron accumulation layer is effectively tuned, providing a way to modulate the injected spin polarization in potential spintronic devices.

Role of Candida albicans-secreted aspartyl proteinases (Saps) in severe early childhood caries.

Candida albicans is strongly associated with severe early childhood caries (S-ECC). However, the roles of secreted aspartyl proteinases (Saps), an important virulence factor of C. albicans, in the progress of S-ECC are not clear. In our study, the Saps activities were evaluated by the yeast nitrogen base-bovine serum albumi (YNB-BSA) agar plate method and by the MTT method with bovine serum albumin (BSA) as the substrate. Genotypes of C. albicans and gene expression of Sap1-5 were evaluated. The relationships of Saps activities and genotypes with S-ECC were analyzed. The results showed that enzyme activities of Saps in the S-ECC group were significantly higher than those in the caries free (CF) group (p<0.05). Genotypes A, B and C were detected in the S-ECC group, and genotypes A and C were detected in the CF group. In the genotype A group, Saps activity in the S-ECC group was significantly different from that in the CF group (p<0.05). The gene expression level of Sap1 in the S-ECC group was significantly higher than that in the CF group (p=0.001), while Sap4 expression was significantly lower than that in the CF group (p=0.029). It can be concluded that Sap1-5 are the predominant proteinase genes expressed in C. albicans from dental biofilm and Sap1 may play an important role in the development of S-ECC.

The association of SNPs in Hsp90ß gene 5' flanking region with thermo tolerance traits and tissue mRNA expression in two chicken breeds.

Thermo stress induces heat shock proteins (HSPs) expression and HSP90 family is one of them that has been reported to involve in cellular protection against heat stress. But whether there is any association of genetic variation in the Hsp90ß gene in chicken with thermo tolerance is still unknown. Direct sequencing was used to detect possible SNPs in Hsp90ß gene 5' flanking region in 3 chicken breeds (n = 663). Six mutations, among which 2 SNPs were chosen and genotypes were analyzed with PCR-RFLP method, were found in Hsp90ß gene in these 3 chicken breeds. Association analysis indicated that SNP of C.-141G>A in the 5' flanking region of the Hsp90ß gene in chicken had some effect on thermo tolerance traits, which may be a potential molecular marker of thermo tolerance, and the genotype GG was the thermo tolerance genotype. Hsp90ß gene mRNA expression in different tissues detected by quantitative real-time PCR assay were demonstrated to be tissue dependent, implying that different tissues have distinct sensibilities to thermo stress. Besides, it was shown time specific and varieties differences. The expression of Hsp90ß mRNA in Lingshan chickens in some tissues including heart, liver, brain and spleen were significantly higher or lower than that of White Recessive Rock (WRR). In this study, we presume that these mutations could be used in marker assisted selection for anti-heat stress chickens in our breeding program, and WRR were vulnerable to tropical thermo stress whereas Lingshan chickens were well adapted.

Tunable spin-orbit interaction in trilayer graphene exemplified in electric-double-layer transistors.

Taking advantage of ultrahigh electric field generated in electric-double-layer transistors (EDLTs), we investigated spin-orbit interaction (SOI) and its modulation in epitaxial trilayer graphene. It was found in magnetotransport that the dephasing length L(φ) and spin relaxation length L(so) of carriers can be effectively modulated with gate bias. As a direct result, SOI-induced weak antilocalization (WAL), together with a crossover from WAL to weak localization (WL), was observed at near-zero magnetic field. Interestingly, among existing localization models, only the Iordanskii-Lyanda-Geller-Pikus theory can successfully reproduce the obtained magnetoconductance well, serving as evidence for gate tuning of the weak but distinct SOI in graphene. Realization of SOI and its large tunability in the trilayer graphene EDLTs provides us with a possibility to electrically manipulate spin precession in graphene systems without ferromagnetics.

Geographic distribution and impacts of climate change on the suitable habitats of Glycyrrhiza species in China.

Climate change has a major impact on the growth and distribution of plants. Glycyrrhiza is widely used in the treatment of many diseases in China. However, with the overexploitation and the growing demand for medicinal uses in of Glycyrrhiza plants. The investigation of the geographical distribution of Glycyrrhiza plants and the analysis of future climate change are of great significance for the conservation of Glycyrrhiza. In this study, combined with administrative maps of Chinese provinces, the present and future of geographical distribution and richness of six Glycyrrhiza plants in China were studied by using DIVA-GIS and MaxEnt software. A total of 981 herbarium records of these six species of Glycyrrhiza were collected to research. Results show that the change of climate in the future will lead to an increase in habitat suitability for some Glycyrrhiza species as follows: Glycyrrhiza inflata by 61.6%, Glycyrrhiza squamulosa by 47.5%, Glycyrrhiza pallidiflora by 34.0%, Glycyrrhiza yunnanensis by 49.0%, Glycyrrhiza glabra by 51.7%, and Glycyrrhiza aspera by 65.9%. Glycyrrhiza plants have considerable medicinal and economic value, so it is necessary to adopt targeted development and rational management strategies for it.