Search

Background: Cardiovascular disease (CVD) is a chronic disease with a serious prognosis, and obesity is a risk factor for CVD. Lipid accumulation product index (LAP) is a new indicator of obesity, waist circumference, and triglycerides were included in the formula, but its association with CVD is inconsistent. Therefore, this study researched the effect of LAP levels on CVD. Methods: This prospective cohort study was based on the Kailuan cohort. A total of 95,981 participants who completed the first physical examination in 2006 and had no history of CVD or LAP absence were included. The participants were divided into four groups according to the LAP quartile (Q1 - Q4). Up until December 31, 2022, incidence density was calculated for each group. The hazard ratio (HR) and 95% confidence interval (CI) of CVD in each group were calculated by the Cox proportional hazards model. Results: During a median follow-up period of 15.95 years, 9925 incident CVD events occurred (2123 myocardial infarction and 8096 stroke). There were differences in potential confounders among the four groups (P < 0.001). The incidence density and 95% CI of CVD in Q1-Q4 groups were 4.76(4.54, 5.00), 6 0.50(6.24, 6.77), 8.13(7.84, 8.44) and 9.34(9.02, 9.67), respectively. There were significant differences in the survival curves among the four groups by log-rank test (P < 0.001). After adjusting for potential confounders, Cox proportional hazards model results showed that compared with the Q1 group, the HR and 95% CI of CVD in the Q2, Q3, and Q4 groups were1.15(1.08, 1.23), 1.29(1.21, 1.38) and 1.39(1.30, 1.49), respectively. The HR and 95%CI of myocardial infarction were 1.28(1.10, 1.49), 1.71(1.47, 1.98) and 1.92(1.64, 2.23), respectively. The HR and 95%CI of stroke were 1.11 (1.03, 1.19), 1.20 (1.12, 1.29) and 1.28 (1.19, 1.38), respectively. After subgroup analysis by gender, there was no significant interaction (P = 0.169), and the relationship between LAP and CVD in different genders was consistent with the main results. After subgroup analysis by age, there was a significant interaction (P = 0.007), and the association between LAP and CVD in different age groups was consistent with the main results. After subgroup analysis by BMI, there was no significant interaction (P = 0.506), and the association between LAP and CVD in different BMI groups was consistent with the main results. The results remained robust after sensitivity analyses. For each unit increase in ln(LAP), the HR and 95%CI of CVD were 4.07 (3.92, 4.23). Conclusion: This study demonstrated that the risk of CVD increased with the increase of LAP level. The risk of CVD in group Q2 - Q4 was 1.15, 1.29, and 1.39 times higher than that in group Q1, respectively. Clinical trial registration number: ChiCTR2000029767 [ABSTRACT FROM AUTHOR]

Although convolutional neural networks (CNNs) have achieved remarkable progress in weakly supervised semantic segmentation (WSSS), there are still deficiencies of object incompleteness due to the lack of receptive field and insufficient utilization of global context information of CNN. Based on the above observations, we propose a simple and effective method, WegFormer. Specifically, WegFormer captures the global context information with the Vision Transformer (ViT) as the classification network and is equipped with Deep Taylor Decomposition (DTD) principle and Soft Erase (SE) module to generate more integral pseudo labels and smooth further. However, we observe that although the generated pseudo‐labels are more complete, they intrude into the background region, that is, background incompleteness problem. The Efficient Potential Object Mining (EPOM) module we propose solves this problem well. Extensive experiments on the challenging PASCAL VOC 2012 and MS COCO 2014 demonstrate the effectiveness of WegFormer, where superior results of 71.4% and 38.3% are obtained on the PASCAL VOC 2012 and MS COCO 2014 validation sets, respectively. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Müller's hydrocarbon and its analogues are classical examples of Kekulé diradicaloids and have gained great attention. However, because of their high reactivities, their isolation and structural characterizations are still challenging. Herein, we report the isolation of two bis‐BN‐based analogues of Müller's hydrocarbon (1 and 2) as crystalline solids in moderate yields. Experimental results and theoretical studies demonstrated that compound 1 possessing the terminal 1,3,2‐diazaboryl groups is an open‐shell singlet diradicaloid, which is in contrast to the closed‐shell singlet ground states of the bis‐BN‐based analogues of Thiele's and Chichibabin's hydrocarbons with the same terminal groups, illustrating the strong influence of the central linkers on the ground state. Additionally, the replacement of the terminal 1,3,2‐diazaboryl groups in 1 with the bis(2,4,6‐triisopropylphenyl)boryl groups affords 2 with higher diradical character and a smaller singlet‐triplet energy gap. [ABSTRACT FROM AUTHOR]

Background: Refractive errors are one of the most common ocular conditions among children and adolescents, with myopia showing an increasing prevalence and early onset in this population. Recent studies have identified a correlation between refractive errors and ocular biometric parameters. Methods: A systematic search was conducted in electronic databases including PubMed, EMBASE, Cochrane Library, Web of Science, and Medline from January 1, 2012, to May 1, 2023. Various ocular biometric parameters were summarized under different refractive states, including axial length (AL), central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness (LT), corneal curvature (CC), Corneal curvature radius (CR),axial length-to-corneal radius ratio (AL/CR ratio), choroidal thickness (ChT), retinal thickness (RT), retinal nerve fiber layer thickness (RNFL), and retinal blood density (VD). The differences in these parameters among different refractive states were analyzed using Stata software with fixed or random-effects models, taking into account the assessed heterogeneity level. Results: This meta-analysis included a total of 69 studies involving 128,178 eyes, including 48,795 emmetropic eyes, 60,691 myopic eyes, 13,983 hyperopic eyes, 2,040 low myopic eyes, 1,201 moderate myopic eyes, and 1,468 high myopic eyes. The results of our study demonstrated that, compared to the control group (emmetropic group), the myopic group and low, moderate, and high myopic groups showed significant increases in AL, AL/CR ratio, and ACD, while the hyperopic group exhibited significant decreases. Compared to the control group, the myopic group had a significantly increase for CC, while CR, CCT, perifoveal RT, subfoveal ChT, foveal ChT, parafoveal ChT, perifoveal (except nasal) ChT, and pRNFL (except temporal) significantly decreased. Compared to the control group, the hyperopic group had a significantly increase for subfoveal ChT, foveal ChT, parafoveal ChT, perifoveal ChT, and nasal pRNFL. Compared to the control group, the low and moderate myopic groups had a significantly decreases for the CCT, parafoveal RT (except nasal), perifoveal RT (except nasal), and pRNFL (except superior and temporal). Compared to the control group, the high myopic group had a significantly increase for CR, while LT, perifoveal ChT (except nasal), parafoveal RT, perifoveal RT, and pRNFL (except temporal) had significant decreased. Conclusion: The changes of ocular biometric parameters in children and adolescents are closely related to refractive errors. Ocular biometric parameters devices, as effective non-invasive techniques, provide objective biological markers for monitoring refractive errors such as myopia. [ABSTRACT FROM AUTHOR]

The initial seed based on the convolutional neural network (CNN) for weakly supervised semantic segmentation always highlights the most discriminative regions but fails to identify the global target information. Methods based on transformers have been proposed successively benefiting from the advantage of capturing long-range feature representations. However, we observe a flaw regardless of the gifts based on the transformer. Given a class, the initial seeds generated based on the transformer may invade regions belonging to other classes. Inspired by the mentioned issues, we devise a simple yet effective method with multi-estimations complementary patch (MECP) strategy and adaptive conflict module (ACM), dubbed MECPformer. Given an image, we manipulate it with the MECP strategy at different epochs, and the network mines and deeply fuses the semantic information at different levels. In addition, ACM adaptively removes conflicting pixels and exploits the network self-training capability to mine potential target information. Without bells and whistles, our MECPformer has reached new state-of-the-art 72.0 % mIoU on the PASCAL VOC 2012 and 42.4 % on MS COCO 2014 dataset. The code is available at https://github.com/ChunmengLiu1/MECPformer. [ABSTRACT FROM AUTHOR]

The physical and chemical properties of nanoribbon edges are important for characterizing nanoribbons and applying them in electronic devices, sensors, and catalysts. The mechanical response of molybdenum disulfide nanoribbons, which is an important issue for their application in thin resonators, is expected to be affected by the edge structure, albeit this result is not yet being reported. In this work, the width‐dependent Young's modulus is precisely measured in single‐layer molybdenum disulfide nanoribbons with armchair edges using the developed nanomechanical measurement based on a transmission electron microscope. The Young's modulus remains constant at ≈166 GPa above 3 nm width, but is inversely proportional to the width below 3 nm, suggesting a higher bond stiffness for the armchair edges. Supporting the experimental results, the density functional theory calculations show that buckling causes electron transfer from the Mo atoms at the edges to the S atoms on both sides to increase the Coulomb attraction. [ABSTRACT FROM AUTHOR]

D. Cvetković, M. Doob and H. Sachs considered the high order eigenvalue problems of graphs. The high order eigenvalues of a graph G are solutions of the high degree homogeneous polynomial equations derived from G. We propose the adjacency tensor A (G) of a graph G and show that the high order eigenvalues of G can be regarded as eigenvalues of A (G). Some results of the spectrum of the adjacency matrix are extended to the spectrum of A (G) by using the spectral theory of nonnegative tensors. An upper bound of chromatic number is given via the spectral radius of A (G). Our upper bound is a generalization of Wilf's bound χ (G) ≤ ρ (G) + 1 (where ρ (G) is the spectral radius of the adjacency matrix of a graph G) and sharper than the bound of Wilf in some classes of graphs. A formula of the number of cliques of fixed size which involve the spectrum of A (G) is obtained. [ABSTRACT FROM AUTHOR]

Mantel’s theorem is a classical result in extremal graph theory which implies that the maximum number of edges of a triangle-free graph of order n. In 1970, Nosal obtained a spectral version of Mantel’s theorem which gave the maximum spectral radius of a triangle-free graph of order n. In this paper, the clique tensor of a graph G is proposed and the spectral Mantel’s theorem is extended via the clique tensor. Furthermore, a sharp upper bound of the number of cliques in G via the spectral radius of the clique tensor is obtained. These results imply that a result of Erdős (Magyar Tud Akad Mat Kutató Int Közl 7:459–464, 1962) under certain conditions. [ABSTRACT FROM AUTHOR]

The heaviest pnictogen-dipyrromethenes DPMPnCl2 (Pn = Sb, 3; Bi 4), which are direct analogues of boron-dipyrromethene (BODIPY), have been readily prepared and isolated as crystalline solids. Both compounds display green photoluminescence with small full widths at half maximum in toluene. Moreover, the reduction of 3 with sodium metal afforded the cyclic dicoordinate stibinidene 5. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Both dipyrromethene complexes and radicals of heavier main group elements have been of high interest. However, cationic germanium radicals and dipyrromethene‐based radicals of heavier main group elements are still escaped to be isolated. Herein, we report the isolation and full characterization of a neutral Ge(I)‐masked dipyrromethene‐based radical 3 and the first cationic Ge(III)‐centered radical 5·+ as stable crystalline solids. 3 behaves as a germanium(I) radical in its reaction with diphenyl disulfide to form the Ge—S bond, although X‐ray crystallographic, EPR spectroscopic, computational studies revealed that the unpaired electron of 3 is mainly delocalized over the C9N2Ge backbone and the allylic radical character is also significant in 3. In contrast to 3, the spin density of 5·+ is mainly localized at the Ge center with minor contribution from the dipyrromethene ligand. Moreover, reduction of 5·+ with potassium graphite quantitatively regenerates 5, illustrating a reversible one‐electron redox pair. [ABSTRACT FROM AUTHOR]

Two radical cations of bis-BN-based analogues of Thiele's hydrocarbons were facilely synthesized, fully characterized, and theoretically investigated. One-electron oxidation leads to the reduced bond length alternation and NICS values of the central C4N2 rings, suggesting the decreasing antiaromatic character. The spin density of the radical cations is significantly delocalized over the central linkers with a small contribution from two terminal N-heterocyclic boryl units. [ABSTRACT FROM AUTHOR]

The first bis(imino)carbazolate pincer ligand supported mononuclear Ga(I) compound LGa: (3) was synthesized and fully characterized. Oxidation of 3 with elemental selenium afforded the dinuclear Ga(III) compound [LGa(μ-Se)]2 (4) bearing two bridging Se atoms. Ligand substitution of Cr(CO)6 with 3 under UV light irradiation afforded the gallylene-chromium complex LGa: → Cr(CO)5 (5). In addition, the attempted synthesis of the aluminium analogue LAl: through reduction of LAlI2 (7) only led to isolation of the dinuclear Al(III) compound (LAlI)2 (8), most probably formed through the C–C coupling of two imino radicals. [ABSTRACT FROM AUTHOR]

Graphene nanoribbon is an attractive material for nano-electronic devices, as their electrical transport performance can be controlled by their edge structures. However, in most cases, the electrical transport has been investigated only for graphene nanoribbons fabricated on a substrate, which hinders the appearance of intrinsic electrical transport due to screening effects. In this study, we developed special devices based on silicon chips for transmission electron microscopy to observe a monolayer graphene nanoribbon suspended between two gold electrodes. Moreover, with the development of an in-situ transmission electron microscopy holder, the current–voltage characteristics were achieved simultaneously with observing and modifying the structure. We found that the current–voltage characteristics differed between 1.5 nm-wide graphene nanoribbons with armchair and zigzag edge structures. The energy gap of the zigzag edge was more than two-fold larger than that of the armchair edge and exhibited an abrupt jump above a critical bias voltage in the differential conductance curve. Thus, our in-situ transmission electron microscopy method is promising for elucidating the structural dependence of electrical conduction in two-dimensional materials. [ABSTRACT FROM AUTHOR]

We give a Brualdi-type Z-eigenvalue inclusion set of tensors, and prove that it is tighter than the inclusion set given by G. Wang, G. L. Zhou, and L. Caccetta [Discrete Contin. Dyn. Syst. Ser. B, 2017, 22: 187–198] in a special case. We also give an inclusion set for lk,s-singular values of rectangular tensors. [ABSTRACT FROM AUTHOR]

A series of Ln-doped KSrPO4 (Ln = Ce3+, Eu3+, Eu2+, Pr3+) phosphors are prepared through a high-temperature solid-state method. The KSrPO4 compound is confirmed to possess a β-K2SO4 structure with the Pnma group by Rietveld refinement, and the temperature-dependent lattice parameters are investigated with the powder X-ray diffraction results at different temperatures. Ce3+ and Eu3+ ions are introduced to probe the crystal field strength (CFS) and the lanthanide site symmetry by using VUV-UV-vis spectroscopy. The temperature-dependent luminescence properties of KSrPO4: Ce3+/Eu2+ exhibit an excellent thermal stability of Ce3+/Eu2+ luminescence. Based on the VUV-UV-vis spectra of Ce3+ and Eu3+ doped KSrPO4, the vacuum referred binding energy (VRBE) scheme is constructed to understand the redox properties of Eu, the 5d energy levels of Pr3+ and the thermal quenching characteristics of Ce3+ and Eu2+ luminescence. [ABSTRACT FROM AUTHOR]

A series of LuNbO4:xDy3+ (x = 0–0.20) phosphors was prepared using a high-temperature solid-state reaction technique. X-ray diffraction (XRD) along with Rietveld refinement, field emission scanning electron microscopy (FE-SEM) observations, diffuse reflectance spectra (DRS), UV-vis photoluminescence (PL), fluorescence decays, PL quantum yields (QYs), and low-voltage cathodoluminescence (CL) were employed to characterize the phosphors. Nonradiative relaxation and host sensitization dramatically influence the LuNbO4:Dy3+ luminescence spectra and decay dynamics. It is shown that cross-relaxation arising from electric dipole–dipole interactions between adjacent Dy3+ ions is the leading mechanism of quenching the Dy3+ emission. The host sensitization for Dy3+ emission in LuNbO4 was confirmed and the energy transfer efficiency from the host to Dy3+ increased with increasing Dy3+ doping concentration/temperature. Upon excitation with ultraviolet light (261 nm) and a low-voltage electron beam (2 kV, 127 μA cm−2), the synthesized LuNbO4:Dy3+ phosphors show both the blue broadband emission of the LuNbO4 host and the characteristic emission of Dy3+ (the dominant one is the 4F9/2→6H13/2 transition, yellow), and the luminescence colour of the LuNbO4:Dy3+ phosphors can be tuned over a large gamut of colours by varying the Dy3+ doping concentration, and a single-phase intense white-light-emission has been achieved in the LuNbO4:0.015Dy3+ phosphor. On the basis of the good UV-vis PL and CL properties, LuNbO4:Dy3+ phosphors might be promising for applications in UV light-emitting diodes (UV-LEDs) and field emission displays (FEDs). [ABSTRACT FROM AUTHOR]

A 180-day incubation experiment was conducted to investigate the effect of different organic materials on the chemical properties of coastal soil with high salinity and relatively low pH. Four organic materials (three kinds of plant residues: straw, composted straw, and fresh reed; and one kind of poultry manure: chicken manure) were applied at a ratio of 15 g·kg to samples of costal saline soil from the Yellow River Delta of China. The results showed that the soil pH and exchangeable sodium percentage (ESP) decreased, whereas soil cation exchangeable capacity (CEC) and macronutrient concentrations increased, regardless of the type of organic material used. All treatments showed a remarkable increase in soil soluble organic carbon (SOC) during the 180-day incubation. The peak values of SOC in descending order were chicken manure, reed, composted straw, straw, and control soil. At the end of incubation, the highest level of SOC occurred in the straw-amended soil, followed by composted straw, reed, and chicken manureamended soils. Soil respiration rate and available nitrogen were significantly influenced by the type of material used. Although reed-amended soil had a relatively high SOC and respiration rate, the ESP was reduced the least. Considering the possible risk of heavy metals caused by chicken manure, it is proposed that straw and composted straw are the more efficient materials to use for reclaiming costal saline soil and improving the availability of macronutrients. [ABSTRACT FROM AUTHOR]

Photoluminescence properties of Ba2MgSi2O7:Eu2+ synthesized by a solid-state reaction method are first investigated in the vacuum ultraviolet (VUV) to visible (vis) excitation energy range. The band gap of the host is found to be around 7.44 eV. The incorporation of Eu2+ leads to bright green luminescence with weak thermal quenching above room temperature. Cathodoluminescence (CL) properties under low-voltage excitations are then studied, and the results suggest a potential application of the compound in field emission displays (FEDs). Electronic properties of the compound are finally calculated by a hybrid density functional theory (DFT) method, and are discussed in association with observed luminescence properties. [ABSTRACT FROM AUTHOR]

The host sensitized near-infrared (NIR) emitting phosphor Sr2CaMoO6:Yb3+ was fabricated by the solid state reaction method. The structural refinement and Raman spectra elucidate that Yb3+ ions preferentially occupy Ca2+ sites. The phosphor can harvest ultraviolet (UV)-blue photons and exhibits intense NIR emission at around 1012 nm with full-width-at-half-maximum of 1635 cm-1. Moreover, the absolute NIR photoluminesence quantum yield (PLQY) is estimated to be about 9%. The Sr2CaMoO6:Yb3+ phosphor may be a promising luminescence downshifting material for improving the spectral response of solar cells in the UV region. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]

Ultraviolet and vacuum ultraviolet spectra are reported for Ce3+ and Eu2+ singly doped into the Sr5(PO4)3Cl lattice, synthesized by a solid-state process. The maxima of the emission intensities are at 346 nm (Ce3+) and 442 nm (Eu2+), with lifetimes of 25 ns and 494 ns, respectively. The Ce3+ excitation spectra exhibit five bands assigned to vibronic structures of the 4f1→ 5d1 electronic transition, in addition to the host absorption at 166 nm at 295 K. The 5d centroid shift is similar to that in SrCl2:Ce3+. The Eu2+ excitation spectrum is mainly comprised of two 4f7→ 4f65d broad bands between 200 nm and 450 nm, peaking at 343 nm and 275 nm. Both of the singly doped systems exhibit concentration quenching, with energy transfer rates being in the low (μs)−1 range for concentrations up to 4 at.% of total cations. The energy transfer rates are linearly and quadratically related to dopant ion concentrations of Ce3+ and Eu2+, respectively. The energy transfer between Ce3+ and Eu2+ in the co-doped Sr5(PO4)3Cl lattice has been studied by the analysis of intensity and decay measurements of both Ce3+ and Eu2+ emissions. The electric dipole–electric dipole transfer has an efficiency of 91% in Sr4.8−xCe0.01EuxNa0.01(PO4)3Cl, with a critical distance of 21 Å. Although energy transfer between Ce3+ and Eu2+ upon excitation into the overlapping Ce3+/Eu2+ absorption band is definitely demonstrated by the dramatic shortening of Ce3+ lifetime, the emission of Eu2+ is also enhanced at low Ce3+ concentrations using exclusive excitation into the Eu2+ absorption band. The quantum yields (QY) of the co-doped system approach those of BaMgAl10O17:Eu2+ (BAM) for the excitation wavelengths of 317 and 365 nm, but are inferior for 254 nm excitation. The addition of 1 at.% Ce3+ to Sr4.98Eu0.02(PO4)3Cl increases the QY by ∼20% of the original value. The cathodoluminesce of the co-doped phosphor is comparable to that of BAM, with CIE coordinates of the emission (0.274, 0.237), so that the application as a field emission display phosphor is proposed. [ABSTRACT FROM AUTHOR]

An intense reddish-orange phosphor, Gd2MoO6:Sm3+, was developed by solid state chemistry. The photoluminescence excitation and emission spectra, concentration effect are investigated. The results show an efficient energy transfer from MoO66- group to Sm3+ occurs and Sm3+ ion emits an intense reddish-orange light with high color purity and an excellent reproduction quality of optical properties. These results demonstrate that Sm3+ ion with low 4f-4f absorption efficiency in near ultraviolet region can play a role of activator in narrow reddish-orange emitting phosphor potentially useful in ∼370 nm GaN-based light emitting diode through efficient energy feeding by charge transfer absorption of MoO66- group. [ABSTRACT FROM AUTHOR]