[Clinical characteristics and genetic analysis of two children with Tuberous sclerosis complex].

OBJECTIVE: To explore the clinical characteristics and genetic variants in two children with Tuberous sclerosis complex (TSC). METHODS: Two children who had presented at the Children's Hospital Affiliated to Zhengzhou University respectively in June 2020 and July 2021 were selected as the study subjects. Clinical data of the children were collected, and potential pathogenic variants were screened by whole exome sequencing (WES). Candidate variants were verified by Sanger sequencing of their family members. RESULTS: Child 1 was a 7-month-and-29-day-old male, and child 2 was a 2-year-and-6-month-old male. Both children had shown symptoms of epileptic seizures and multiple hypomelanotic macules. Genetic testing revealed that both children had harbored de novo variants of the TSC2 gene, namely c.3239_3240insA and c.3330delC, which were unreported previously. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), both variants were rated as pathogenic (PVS1+PS2+PM2_Supporting). CONCLUSION: This study has uncovered the genetic etiology for two children with TSC. Above findings have also enriched the phenotypic and mutational spectrum of TSC in the Chinese population.

[Application of fluorescence in situ hybridization combined with chromosomal karyotyping analysis in children with disorders of sex development due to sex chromosome abnormalities].

OBJECTIVE: To retrospectively analyze sex chromosomal abnormalities and clinical manifestations of children with disorders of sex development (DSD). METHODS: A total of 14 857 children with clinical features of DSD including short stature, cryptorchidism, hypospadia, buried penis and developmental delay were recruited from Zhengzhou Children's Hospital from January 2013 to March 2022. Fluorescence in situ hybridization (FISH) and chromosomal karyotyping were carried out for such children. RESULTS: In total 423 children were found to harbor sex chromosome abnormalities, which has yielded a detection rate of 2.85%. There were 327 cases (77.30%) with Turner syndrome and a 45,X karyotype or its mosaicism. Among these, 325 were females with short stature as the main clinical manifestation, 2 were males with short stature, cryptorchidism and hypospadia as the main manifestations. Sixty-two children (14.66%) had a 47,XXY karyotype or its mosaicism, and showed characteristics of Klinefelter syndrome (KS) including cryptorchidism, buried penis and hypospadia. Nineteen cases (4.49%) had sex chromosome mosaicisms (XO/XY), which included 11 females with short stature, 8 males with hypospadia, and 6 cases with cryptorchidism, buried penis, testicular torsion and hypospadia. The remainder 15 cases (3.55%) included 9 children with a XYY karyotype or mosaicisms, with main clinical manifestations including cryptorchidisms and hypospadia, 4 children with a 47,XXX karyotype and clinical manifestations including short stature and labial adhesion, 1 child with a 46,XX/46,XY karyotype and clinical manifestations including micropenis, hypospadia, syndactyly and polydactyly, and 1 case with XXXX syndrome and clinical manifestations including growth retardation. CONCLUSION: Among children with DSD due to sex chromosomal abnormalities, sex chromosome characteristics consistent with Turner syndrome was most common, among which mosaicism (XO/XX) was the commonest. In terms of clinical manifestations, the females mainly featured short stature, while males mainly featured external genital abnormalities. Early diagnosis and treatment are particularly important for improving the quality of life in such children.

[Analysis of CLCN4 gene variant in a child with Raynaud-Claes syndrome].

OBJECTIVE: To analyze the clinical phenotype and genetic variant in a child with Raynaud-Claes syndrome (RCS). METHODS: A child who was diagnosed with RCS at the Children's Hospital Affiliated to Zhengzhou University for delayed language and motor development in August 2022 was selected as the study subject. Clinical data of the child were collected, and potential genetic variant was detected by next-generation sequencing and Sanger sequencing. The pathogenicity of the candidate variant was analyzed. RESULTS: The child, a 4-year-and-4-month-old male, has manifested global developmental delay, speech disorders, special facial features and behavioral abnormalities. Genetic testing revealed that he has harbored a hemizygous c.1174C>T (p.Gln392Ter) variant of the CLCN4 gene, which was not detected in either of his parents. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the variant was rated as pathogenic (PVS1+PS2+PM2_Supporting). CONCLUSION: The c.1174C>T (p.Gln392Ter) variant of the CLCN4 gene probably underlay the PCS in this child. Above finding has expanded the mutational spectrum of the CLCN4 gene and enabled genetic counseling and prenatal diagnosis for his family.

Atomic-Scale Insights into the Interlayer Characteristics and Oxygen Reactivity of Bilayer Borophene.

Bilayer (BL) two-dimensional boron (i.e., borophene) has recently been synthesized and computationally predicted to have promising physical properties for a variety of electronic and energy technologies. However, the fundamental chemical properties of BL borophene that form the foundation of practical applications remain unexplored. Here, we present atomic-level chemical characterization of BL borophene using ultrahigh vacuum tip-enhanced Raman spectroscopy (UHV-TERS). UHV-TERS identifies the vibrational fingerprint of BL borophene with angstrom-scale spatial resolution. The observed Raman spectra are directly correlated with the vibrations of interlayer boron-boron bonds, validating the three-dimensional lattice geometry of BL borophene. By virtue of the single-bond sensitivity of UHV-TERS to oxygen adatoms, we demonstrate the enhanced chemical stability of BL borophene compared to its monolayer counterpart by exposure to controlled oxidizing atmospheres in UHV. In addition to providing fundamental chemical insight into BL borophene, this work establishes UHV-TERS as a powerful tool to probe interlayer bonding and surface reactivity of low-dimensional materials at the atomic scale.

Controlling Localized Plasmons via an Atomistic Approach: Attainment of Site-Selective Activation inside a Single Molecule.

Chemical reactions such as bond dissociation and formation assisted by localized surface plasmons (LSPs) of noble metal nanostructures hold promise in solar-to-chemical energy conversion. However, the precise control of localized plasmons to activate a specific moiety of a molecule, in the presence of multiple chemically equivalent parts within a single molecule, is scarce due to the relatively large lateral distribution of the plasmonic field. Herein, we report the plasmon-assisted dissociation of a specific molecular site (C-Si bond) within a polyfunctional molecule adsorbed on a Cu(100) surface in the scanning tunneling microscope (STM) junction. The molecular site to be activated can be selected by carefully positioning the tip and bringing the tip extremely close to the molecule (atomistic approach), thereby achieving plasmonic nanoconfinement at the tip apex. Furthermore, multiple reactive sites are activated in a sequential manner at the sub-molecular scale, and different sets of products are created and visualized by STM topography and density functional theory (DFT) modeling. The illustration of site-selective activation achieved by localized surface plasmons implies the realization of molecular-scale resolution for bond-selected plasmon-induced chemistry.

Angstrom-Scale Spectroscopic Visualization of Interfacial Interactions in an Organic/Borophene Vertical Heterostructure.

Two-dimensional boron monolayers (i.e., borophene) hold promise for a variety of energy, catalytic, and nanoelectronic device technologies due to the unique nature of boron-boron bonds. To realize its full potential, borophene needs to be seamlessly interfaced with other materials, thus motivating the atomic-scale characterization of borophene-based heterostructures. Here, we report the vertical integration of borophene with tetraphenyldibenzoperiflanthene (DBP) and measure the angstrom-scale interfacial interactions with ultrahigh-vacuum tip-enhanced Raman spectroscopy (UHV-TERS). In addition to identifying the vibrational signatures of adsorbed DBP, TERS reveals subtle ripples and compressive strains of the borophene lattice underneath the molecular layer. The induced interfacial strain is demonstrated to extend in borophene by ∼1 nm beyond the molecular region by virtue of 5 Šchemical spatial resolution. Molecular manipulation experiments prove the molecular origins of interfacial strain in addition to allowing atomic control of local strain with magnitudes as small as ∼0.6%. In addition to being the first realization of an organic/borophene vertical heterostructure, this study demonstrates that UHV-TERS is a powerful analytical tool to spectroscopically investigate buried and highly localized interfacial characteristics at the atomic scale, which can be applied to additional classes of heterostructured materials.

Tip-enhanced Raman spectroscopy: Chemical analysis with nanoscale to angstrom scale resolution.

Tip-enhanced Raman spectroscopy (TERS), a cutting-edge near-field spectroscopic tool, provides invaluable chemical insight with impressive spatial resolution in chemistry-related fields such as molecular and catalytic systems, surface science, two-dimensional materials, and biochemistry. High-resolution TERS, in particular, which has advanced exceptionally in the last five years, provides a unique opportunity to scrutinize single molecules individually. Here, this perspective places emphasis on the basic concepts and recent experimental findings of this state-of-the-art research and concludes with a glimpse of future prospects.

Angstrom Scale Chemical Analysis of Metal Supported Trans- and Cis-Regioisomers by Ultrahigh Vacuum Tip-Enhanced Raman Mapping.

Real space chemical analysis of two structurally very similar components, that is, regioisomers lies at the heart of heterogeneous catalysis reactions, modern-age electronic devices, and various other surface related problems in surface science and nanotechnology. One of the big challenges in surface chemistry is to identify different surface adsorbed molecules and analyze their chemical properties individually. Herein, we report a topological and chemical analysis of two regioisomers, trans- and cis-tetrakispentafluorophenylporphodilactone ( trans- and cis-H2F20TPPDL) molecules by high-resolution scanning tunneling microscopy, and ultrahigh vacuum tip-enhanced Raman spectroscopy (UHV-TERS). Both isomeric structures are investigated individually on Ag(100) at liquid nitrogen temperature. Following that, we have successfully distinguished these two regioisomeric molecules simultaneously through TERS with an angstrom scale (8 Å) spatial resolution. Also, the two-component organic heterojunction has been characterized at large scale using high-resolution two-dimensional mapping. Combined with time-dependent density functional theory simulations, we explain the TERS spectral discrepancies for both isomers in the fingerprint region.

[The value of detecting MLL gene rearrangement in children with acute monocytic leukemia].

OBJECTIVE: To assess the value of detecting the rearrangement of mixed lineage leukemia (MLL) gene in children with acute mononuclear leukemia (AML). METHODS: Dual-color fluorescence in situ hybridization (FISH) probe was used to detect MLL gene rearrangement in 68 children with AML by interphase FISH. The results were compared with that of conventional G banding chromosomal analysis. RESULTS: Among the 68 children, 28 were detected by FISH with positive hybridization signals, with a detection rate for MLL gene rearrangement being 41.2%. Twelve (17.6%) reciprocal translocations and interruption of 11q23 were detected by G banding analysis. The difference in the detection rates between the two methods was statistically significant (P< 0.05). CONCLUSION: The sensitivity of FISH assay for MLL gene rearrangement was significantly higher than that of G banding chromosomal karyotyping. Combined use of both methods for children with AML can improve the detection rate of MLL gene rearrangements and provide crucial clues for clinical diagnosis, treatment and prognosis.

Carbon Monoxide Oxidation on Metal-Supported Monolayer Oxide Films: Establishing Which Interface is Active.

Ultrathin (monolayer) films of transition metal oxides grown on metal substrates have recently received considerable attention as promising catalytic materials, in particular for low-temperature CO oxidation. The reaction rate on such systems often increases when the film only partially covers the support, and the effect is commonly attributed to the formation of active sites at the metal/oxide boundary. By studying the structure and reactivity of FeO(111) films on Pt(111), it is shown that, independent of the film coverage, CO oxidation takes place at the interface between reduced and oxidized phases in the oxide film formed under reaction conditions. The promotional role of a metal support is to ease formation of the reduced phase by reaction between CO adsorbed on metal and oxygen at the oxide island edge.

Fabrication of graphene-silicon layered heterostructures by carbon penetration of silicon film.

A new, easy, in situ technique for fabricating a two-dimensional graphene-silicon layered heterostructure has been developed to meet the demand for integration between graphene and silicon-based microelectronic technology. First, carbon atoms are stored in bulk iridium, and then silicon atoms are deposited onto the Ir(111) surface and annealed. With longer annealing times, the carbon atoms penetrate from the bulk iridium to the top of the silicon and eventually coalesce there into graphene islands. Atomically resolved scanning tunneling microscopy images, high-pass fast Fourier transform treatment and Raman spectroscopy demonstrate that the top graphene layer is intact and continuous, and beneath it is the silicon layer.

Preparation and structure of Fe-containing aluminosilicate thin films.

In attempts to fabricate model systems of Fe-containing aluminosilicates, we studied the incorporation of iron into silicate and aluminosilicate bilayer films grown on Ru(0001). Structural characterization was performed by low energy electron diffraction, X-ray photoelectron spectroscopy, infrared reflection-absorption spectroscopy and scanning tunneling microscopy. The experimental results show that even at low concentrations Fe does not randomly substitute Si(Al) cations in the silicate framework, but segregates into a pure silicate (aluminosilicate) phase and an Fe-silicate phase which is formed by an FeO(111)-like layer underneath a silicate layer. At high Fe/(Si + Al) molar ratios, the resulting films showed two phases depending on the annealing temperature. In both phases, the surface exposes a silicate layer and the bottom layer is dominated by FeO. The Al ions seem to be present in the bottom layer at relatively low oxidation temperatures, but segregate as alumina clusters at the surface at higher temperatures. The results suggest that the formation of in-frame Fe species in silicalites and zeolites is thermodynamically unfavourable. This study provides further steps towards the rational design of model systems for studying surface chemistry of a wide class of layered minerals.

Monolayer PtSe2, a New Semiconducting Transition-Metal-Dichalcogenide, Epitaxially Grown by Direct Selenization of Pt.

Single-layer transition-metal dichalcogenides (TMDs) receive significant attention due to their intriguing physical properties for both fundamental research and potential applications in electronics, optoelectronics, spintronics, catalysis, and so on. Here, we demonstrate the epitaxial growth of high-quality single-crystal, monolayer platinum diselenide (PtSe2), a new member of the layered TMDs family, by a single step of direct selenization of a Pt(111) substrate. A combination of atomic-resolution experimental characterizations and first-principle theoretic calculations reveals the atomic structure of the monolayer PtSe2/Pt(111). Angle-resolved photoemission spectroscopy measurements confirm for the first time the semiconducting electronic structure of monolayer PtSe2 (in contrast to its semimetallic bulk counterpart). The photocatalytic activity of monolayer PtSe2 film is evaluated by a methylene-blue photodegradation experiment, demonstrating its practical application as a promising photocatalyst. Moreover, circular polarization calculations predict that monolayer PtSe2 has also potential applications in valleytronics.

Construction of 2D atomic crystals on transition metal surfaces: graphene, silicene, and hafnene.

The synthesis and structures of graphene on Ru(0001) and Pt(111), silicene on Ag(111) and Ir(111) and the honeycomb hafnium lattice on Ir(111) are reviewed. Epitaxy on a transition metal (TM) substrate is a pro-mising method to produce a variety of two dimensional (2D) atomic crystals which potentially can be used in next generation electronic devices. This method is particularly valuable in the case of producing 2D materials that do not exist in 3D forms, for instance, silicene. Based on the intensive investigations of epitaxial graphene on TM in recent years, it is known that the quality of graphene is affected by many factors, including the interaction between the 2D material overlayer and the substrate, the lattice mismatch, the nucleation density at the early stage of growth. It is found that these factors also apply to many other epitaxial 2D crystals on TM. The knowledge from the reviewed systems will shine light on the design and synthesis of new 2D crystals with novel properties.

Buckled silicene formation on Ir(111).

Silicene, a two-dimensional (2D) honeycomb structure similar to graphene, has been successfully fabricated on an Ir(111) substrate. It is characterized as a (√7×√7) superstructure with respect to the substrate lattice, as revealed by low energy electron diffraction and scanning tunneling microscopy. Such a superstructure coincides with the (√3×√3) superlattice of silicene. First-principles calculations confirm that this is a (√3×√3)silicene/(√7×√7)Ir(111) configuration and that it has a buckled conformation. Importantly, the calculated electron localization function shows that the silicon adlayer on the Ir(111) substrate has 2D continuity. This work provides a method to fabricate high-quality silicene and an explanation for the formation of the buckled silicene sheet.

Two-dimensional transition metal honeycomb realized: Hf on Ir(111).

Two-dimensional (2D) honeycomb systems made of elements with d electrons are rare. Here, we report the fabrication of a transition metal (TM) 2D layer, namely, hafnium crystalline layers on Ir(111). Experimental characterization reveals that the Hf layer has its own honeycomb lattice, morphologically identical to graphene. First-principles calculations provide evidence for directional bonding between adjacent Hf atoms, analogous to carbon atoms in graphene. Calculations further suggest that the freestanding Hf honeycomb could be ferromagnetic with magnetic moment µ/Hf = 1.46 µ(B). The realization and investigation of TM honeycomb layers extend the scope of 2D structures and could bring about novel properties for technological applications.

Nanoscale Chemical Probing of Metal-Supported Ultrathin Ferrous Oxide via Tip-Enhanced Raman Spectroscopy and Scanning Tunneling Microscopy.

Metal-supported ultrathin ferrous oxide (FeO) has attracted immense interest in academia and industry due to its widespread applications in heterogeneous catalysis. However, chemical insight into the local structural characteristics of FeO, despite its critical importance in elucidating structure-property relationships, remains elusive. In this work, we report the nanoscale chemical probing of gold (Au)-supported ultrathin FeO via ultrahigh-vacuum tip-enhanced Raman spectroscopy (UHV-TERS) and scanning tunneling microscopy (STM). For comparative analysis, single-crystal Au(111) and Au(100) substrates are used to tune the interfacial properties of FeO. Although STM images show distinctly different moiré superstructures on FeO nanoislands on Au(111) and Au(100), TERS demonstrates the same chemical nature of FeO by comparable vibrational features. In addition, combined TERS and STM measurements identify a unique wrinkled FeO structure on Au(100), which is correlated to the reassembly of the intrinsic Au(100) surface reconstruction due to FeO deposition. Beyond revealing the morphologies of ultrathin FeO on Au substrates, our study provides a thorough understanding of the local interfacial properties and interactions of FeO on Au, which could shed light on the rational design of metal-supported FeO catalysts. Furthermore, this work demonstrates the promising utility of combined TERS and STM in chemically probing the structural properties of metal-supported ultrathin oxides on the nanoscale.

[Factors Influencing Willingness of Farmers to Pay for Agricultural Non-point Source Pollution Control Based on Distributed Cognitive Theory].

The analysis of the willingness of individual farmers to cover costs is an important basis for measuring the economic value of agricultural non-point pollution management， and determining the ecological and economic value of rural surface pollution control is a necessary measure to internalize the externalities of agricultural production. Based on the analysis of the hierarchy of factors influencing the cognition of farmers， this study constructed a theoretical framework based on distributed cognition theory to analyze their willingness to pay for agricultural non-point source pollution control from the perspective of individual farmers. On the basis of this framework， we used the Double-Hurdle model to empirically test the overall process of farmers'willingness to pay and their willingness to pay the amount for agricultural non-point source pollution control by combining 531 microscopic research datapoints in Guanzhong， Shaanxi Province. The results showed that： ① the number of farmers with willingness to pay for agricultural non-point source pollution control was 267， accounting for 50.30% of the total sample， and the average value of willingness to pay was 1 469.77 yuan·hm-2； the total economic value of agricultural non-point source pollution control in Shaanxi Province in 2020 was estimated to be 5.791 billion yuan based on the expected value of the willingness to pay level of the research sample. ② Farmers'willingness to pay for agricultural non-point source pollution control was influenced by the combined effects of personal， regional， and cultural forces， and the effects of each dimension were similar； farmers' willingness to pay for agricultural non-point source pollution control was mainly influenced by the cultural force factor， and the effects of personal and regional forces were very limited. ③ The results of the regressions by income level showed that personal and cultural strengths had a significant impact on the willingness to pay among the low-income group but did not contribute to the increase in the willingness to pay.

Numerical study of Richtmyer-Meshkov instability in finite thickness fluid layers with reshock.

The evolution of a shock-induced fluid layer is numerically investigated in order to reveal the underlying mechanism of the Richtmyer-Meshkov instability under the effect of a reshock wave. Six different types of fluid layer are initially set up to study the effect of amplitude perturbation, fluid-layer thickness, and phase position on the reshocked fluid-layer evolution. Interface morphology results show that the interface-coupling effect gets strengthened when the fluid-layer thickness is small, which means the development of spikes and bubbles is inhibited to some extent compared to the case with large initial fluid-layer thickness. Two jets emerge on interface II_{1} under out-of-phase conditions, while bubbles are generated on interface II_{1} when the initial phase position is in-phase. The mixing width of the fluid layer experiences an early linear growth stage and a late nonlinear stage, between which the growth of the mixing width is considerably inhibited by the passage of the first and the second reshock and mildly weakened during phase reversion. The amplitude growth of interfaces agrees well with the theoretical model prediction, including both the linear and nonlinear stages. In the very late stage, the amplitude perturbation growth tends to differ from the theoretical prediction due to the squeezing effect and stretching effect.

Can low-carbon cities increase urban housing prices? Evidence from China's low-carbon city pilot.

The low-carbon transformation is a broad and profound systemic change that will inevitably impact many areas of the urban environment, economy, and social system. We evaluated the impact of China's ongoing "low-carbon pilot policy" on urban housing prices as a "quasi-natural experiment." Existing research findings and hedonic theory predictions suggest that the low-carbon city pilot (LCCP) policy is increasing urban housing prices through air quality improvements. However, this study contradicts these speculations based on the situation in China. This study employed the analytical framework of staggered difference-in-differences (DID), which revealed that the LCCP policy had generally reduced housing prices; the implementation of the policy had led to an average decrease of 6.2% in housing prices in pilot cities, compared to non-pilot cities. The LCCP policy affected housing prices by influencing both the "demand side" and "supply side" of housing. In terms of the demand side, the policy significantly reduced the level of urban air pollution but did not impact housing prices. Instead, it negatively affected housing prices by lowering labor wages. In terms of the supply side, housing prices were negatively affected, mainly by increasing the cost of emission reduction of real estate enterprises, which impacted the original longstanding housing production process. Additionally, there were significant differences in the impact of the LCCP policy on housing prices in cities across different geographical locations and different tiers of cities. This study suggests important policy insights for achieving stable market housing prices and promoting high-quality urban development in the process of low-carbon transformation.