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Objective To investigate the application value of 3D microscope in vascular anastomosis in oral and maxillofacial surgery, to provide a reference for clinicians. Methods Eighty-seven cases of free flap reconstruction in oral and maxillofacial surgery were retrospectively included, including 30 cases in the 3D microscope group and 57 cases in the optical microscope group. The differences in intraoperative vascular anastomosis time, postoperative flap survival rate and doctor evaluation scores between the 3D microscope group and the optical microscope group were compared and statistically analyzed, and the feasibility of using three-dimensional microscope in surgery was evaluated. Results The arterial anastomosis time was (26.53±3.83) min/root in the 3D microscope group and (24.88 ± 2.97) min/root in the optical microscope group, and the difference was statistically significant (P0.05). The doctor's evaluation scores of visual fatigue, training and learning, operative difficulty index, image sharing in the three-dimensional microscope group were higher than those in the optical microscope group, and the differences were statistically significant (P

Objective To summarize the clinical manifestations of IgG4-related diseases in the head and neck, explore treatment methods. Methods The clinical data of 21 patients diagnosed with IgG4-related diseases were retrospectively analyzed. The clinical data and the results of glucocorticoid and immunosuppressive therapy were studied retrospectively. Results All patients had swollen sclerotic masses, and CT showed irregular high-density masses with uniform enhancement in the enlarged glands. Some patients had mucosal thickening and mass-like changes in theoral cavity, nose, sinuses, throat and other tissues, and most of the patients had cervical lymphadenopathy and elevated serum IgG4 levels (≥ 1.35 g/L). Histopathological examination of affected exosine glands and affected mucosa and lymph nodes in all patients showed infiltration of lymphocytes, plasma cells and IgG4+ plasma cells. In 21 patients, the mass in the affected glands and mucosa (including head, neck and other tissues) disappeared, and the clinical symptoms were relieved after the application of glucocorticoids. However, with a reduction in glucocorticoids, the mass recurred or even worsened. Conclusion For patients with a single mass in the submandibular gland, parotid gland and other salivary glands, as well as lymph node enlargement, CT is the first choice to identify the nature of gland neoplasms. Combined with pathological examination, related auxiliary examination and peripheral blood examination are also needed to obtain a definitive diagnosis. Glucocorticoid therapy is used to achieve a good prognosis, and long-term follow-up and timely adjustment of medication regimens are required.

A novel complex Ni(C12H12N2)3●(C7H5O3)2●(H3BO3) has been synthesized from a hydrothermal reaction and the crystal structure has been determined by means of single-crystal X-ray diffraction. Triclinic, P-1. a= 12.5380(13) Å, b = 13.0100(15) Å, c = 15.1490(18) Å, α= 102.760(3)°, β= 94.480(2)°, γ= 94.540(2)°. V=2390.9(5) Å3. Z=2. R1 =0.0661, wR2 = 0.2128, T=293(2) K. The Ni atom is coordinated by six N atoms from three 4,4′-dimethyl-2,2′-dipyridyl molecular. The molecular structure stabilized by the O-H…O hydrogen-bonding interactions.

Cells are known to perceive their microenvironment through extracellular and intracellular mechanical signals. Upon sensing mechanical stimuli, cells can initiate various downstream signaling pathways that are vital to regulating proliferation, growth, and homeostasis. One such physiologic activity modulated by mechanical stimuli is osteogenic differentiation. The process of osteogenic mechanotransduction is regulated by numerous calcium ion channels-including channels coupled to cilia, mechanosensitive and voltage-sensitive channels, and channels associated with the endoplasmic reticulum. Evidence suggests these channels are implicated in osteogenic pathways such as the YAP/TAZ and canonical Wnt pathways. This review aims to describe the involvement of calcium channels in regulating osteogenic differentiation in response to mechanical loading and characterize the fashion in which those channels directly or indirectly mediate this process. The mechanotransduction pathway is a promising target for the development of regenerative materials for clinical applications due to its independence from exogenous growth factor supplementation. As such, also described are examples of osteogenic biomaterial strategies that involve the discussed calcium ion channels, calcium-dependent cellular structures, or calcium ion-regulating cellular features. Understanding the distinct ways calcium channels and signaling regulate these processes may uncover potential targets for advancing biomaterials with regenerative osteogenic capabilities.

Custom synthesis of extracellular matrix (ECM)-inspired materials for condition-specific reconstruction has emerged as a potentially translatable regenerative strategy. In skull defect reconstruction, nanoparticulate mineralized collagen glycosaminoglycan scaffolds (MC-GAG) have demonstrated osteogenic and anti-osteoclastogenic properties, culminating in the ability to partially heal in vivo skull defects without the addition of exogenous growth factors or progenitor cell loading. In an effort to reduce catabolism during early skull regeneration, we fabricated a composite material (MCGO) of MC-GAG and recombinant osteoprotegerin (OPG), an endogenous anti-osteoclastogenic decoy receptor. In the presence of differentiating osteoprogenitors, MCGO demonstrated an additive effect with endogenous OPG limited to the first 14 days of culture with total eluted and scaffold-bound OPG exceeding that of MC-GAG. Functionally, MCGO exhibited similar osteogenic properties as MC-GAG, however, MCGO significantly reduced maturation and resorptive activities of primary human osteoclasts. In a rabbit skull defect model, MCGO scaffold-reconstructed defects displayed higher mineralization as well as increased hardness and microfracture resistance compared to non-OPG functionalized MC-GAG scaffolds. The current work suggests that MCGO is a development in the goal of reaching a materials-based strategy for skull regeneration.

Targeted refinement of regenerative materials requires mechanistic understanding of cell-material interactions. The nanoparticulate mineralized collagen glycosaminoglycan (MC-GAG) scaffold is shown to promote skull regeneration in vivo without additive exogenous growth factors or progenitor cells, suggesting potential for clinical translation. This work evaluates modulation of MC-GAG stiffness on canonical Wnt (cWnt) signaling. Primary human bone marrow-derived mesenchymal stem cells (hMSCs) are differentiated on two MC-GAG scaffolds (noncrosslinked, NX-MC, 0.3 kPa vs conventionally crosslinked, MC, 3.9 kPa). hMSCs increase expression of activated β-catenin, the major cWnt intracellular mediator, and the mechanosensitive YAP protein with near complete subcellular colocalization on stiffer MC scaffolds. Overall Wnt pathway inhibition reduces activated β-catenin and osteogenic differentiation, while elevating BMP4 and phosphorylated Smad1/5 (p-Smad1/5) expression on MC, but not NX-MC. Unlike Wnt pathway downregulation, isolated canonical Wnt inhibition with β-catenin knockdown increases osteogenic differentiation and mineralization specifically on the stiffer MC. β-catenin knockdown also increases p-Smad1/5, Runx2, and BMP4 expression only on the stiffer MC material. Thus, while stiffness-induced activation of the Wnt and mechanotransduction pathways promotes osteogenesis on MC-GAG, activated β-catenin is a limiting agent and may serve as a useful target or readout for optimal modulation of stiffness in skeletal regenerative materials.

The ability of the extracellular matrix (ECM) to instruct progenitor cell differentiation has generated excitement for the development of materials-based regenerative solutions. Described a nanoparticulate mineralized collagen glycosaminoglycan (MC-GAG) material capable of inducing in vivo skull regeneration without exogenous growth factors or ex vivo progenitor cell-priming is described previously. Here, the contribution of titrating stiffness to osteogenicity is evaluated by comparing noncrosslinked (NX-MC) and crosslinked (MC) forms of MC-GAG. While both materials are osteogenic, MC demonstrates an increased expression of osteogenic markers and mineralization compared to NX-MC. Both materials are capable of autogenously activating the canonical BMPR signaling pathway with phosphorylation of Smad1/5. However, unlike NX-MC, human mesenchymal stem cells cultured on MC demonstrate significant elevations in the major mechanotransduction mediators YAP and TAZ expression, coincident with β-catenin activation in the canonical Wnt signaling pathway. Inhibition of YAP/TAZ activation reduces osteogenic expression, mineralization, and β-catenin activation in MC, with less of an effect on NX-MC. YAP/TAZ inhibition also results in a reciprocal increase in Smad1/5 phosphorylation and BMP2 expression. The results indicate that increasing MC-GAG stiffness induces osteogenic differentiation via the mechanotransduction mediators YAP/TAZ and the canonical Wnt signaling pathway, whereas the canonical BMPR signaling pathway is activated independent of stiffness.

The instructive capabilities of extracellular matrix-inspired materials for osteoprogenitor differentiation have sparked interest in understanding modulation of other cell types within the bone regenerative microenvironment. We previously demonstrated that nanoparticulate mineralized collagen glycosaminoglycan (MC-GAG) scaffolds efficiently induced osteoprogenitor differentiation and bone healing. In this work, we combined adenovirus-mediated delivery of osteoprotegerin (AdOPG), an endogenous anti-osteoclastogenic decoy receptor, in primary human mesenchymal stem cells (hMSCs) with MC-GAG to understand the role of osteoclast inactivation in augmentation of bone regeneration. Simultaneous differentiation of osteoprogenitors on MC-GAG and osteoclast progenitors resulted in bidirectional positive regulation. AdOPG expression did not affect osteogenic differentiation alone. In the presence of both cell types, AdOPG-transduced hMSCs on MC-GAG diminished osteoclast-mediated resorption in direct contact; however, osteoclast-mediated augmentation of osteogenic differentiation was unaffected. Thus, the combination of OPG with MC-GAG may represent a method for uncoupling osteogenic and osteoclastogenic differentiation to augment bone regeneration.

The ability of the extracellular matrix (ECM) to direct cell fate has generated the potential for developing a materials-only strategy for tissue regeneration. Previously, we described a nanoparticulate mineralized collagen glycosaminoglycan (MC-GAG) material that efficiently induced osteogenic differentiation of human mesenchymal stem cells (hMSCs) and calvarial bone healing without exogenous growth factors or progenitor cell expansion. In this work, we evaluated the interactions between MC-GAG and primary human osteoclasts (hOCs). In the absence of hMSCs, mineralized Col-GAG materials directly inhibited hOC viability, proliferation, and resorption in contrast to nonmineralized Col-GAG, which demonstrated a modest inhibition of resorptive activity only. Cocultures containing differentiating hMSCs with hOCs demonstrated increased hOC-mediated resorption only on Col-GAG while MC-GAG cocultures continued to inhibit resorption. Unlike Col-GAG, hMSCs on MC-GAG expressed increased amounts of osteoprotegerin (OPG) protein, the major endogenous osteoclast inhibitor. Interestingly, OPG expression was found to be antagonized by small mothers against decapentaplegic1/5 (Smad1/5) phosphorylation, an obligate pathway for osteogenic differentiation of hMSCs on MC-GAG, and potentiated by extracellular signal-regulated kinase (ERK1/2) phosphorylation. Collectively, these results suggested that the MC-GAG material both directly inhibited the osteoclast viability, proliferation, and resorptive activity as well as induced hMSCs to secrete osteoprotegerin, an antiosteoclastogenic factor, via a signalling pathway distinct from osteogenic differentiation.

Deciphering the precise catalytic growth mechanism of atomically thin graphene-based lateral heterostructures is of great interest in low-dimensional physics and materials. Here, based on first-principles calculations and extensive screenings, we reveal that the deposited transition metal atoms (TM = Mn, Zr, Nb, Mo, Hf, Ta, and W), particularly Mo, act as single-atom catalysts (SACs) to effectively promote C adatom dimerization both energetically and kinetically on a C-dimer-unpreferred Rh(111) substrate. Meanwhile, the TM-SAC increases the stability of the boron-nitride (BN) dimer, which promotes rapid growth of a hexagonal boron nitride-graphene (h-BN-G) lateral heterostructure. Specifically, taking TM = Mo as a typical example, we demonstrate that the Mo–C(BN) couplings weaken the C(BN)-substrate interactions, which sharply reduces the kinetic barriers for both C and BN nucleation and migration in the initial stage of growing the h-BN-G lateral heterostructure on Rh(111). Interestingly, Mo-SAC can dynamically involve and migrate out of the h-BN-G interface during the growth processes for C2 dimers as feeding blocks. Moreover, the presence of Mo-SAC can effectively tune the patching boundary of the 1D h-BN-G heterostructure, i.e., from C–N to C–B linking with half-metallicity. The present findings provide significantly new insights into controllable catalytic growth of two-dimensional (2D) lateral heterostructures with various important potential applications, such as transport in spintronic devices. [ABSTRACT FROM AUTHOR]

Tin-based Babbitt alloys are a widely used bearing bushing material which have good comprehensive properties. However, problems such as high-temperature softening and insufficient bearing capacity occur during their use, so the optimization of tin-based Babbitt alloys has become a research hotspot. In this paper, ZChSnSb11-6 alloy was mainly prepared by the gravity casting method, and different amounts of Zn were added to the alloy (the mass fraction values were 0 wt.%, 0.05 wt.%, 0.1 wt.%, 0.15 wt.%, and 0.2 wt.%, respectively). Through the hardness test, the tensile test, the friction and wear test, and the microstructure observation of the prepared alloy, the influence of Zn on the organization and properties of the ZChSnSb11-6 alloy was analyzed. The results show that the size of the SnSb hard phase changed with the increasing content of Zn. The size of the hard phase of the SnSb tended to increase first and then decrease, and the number of phase particles increased first and then decreased, resulting in changes in performance. Through comparison, it was learned that the addition of Zn can effectively improve the hardness, tensile strength, yield strength, and wear resistance of the alloy, but the elongation rate was reduced. When the Zn content was 0.1 wt.%, the hardness value of the alloy reached the maximum value, 25.82 HB, which increased by 7.3% when compared with the sample without Zn. The hardness of the Zn, 0.15 wt.%, is close to that of the Zn, 0.1 wt.%. Compared to the sample without Zn, the tensile strength and elongation of the alloy were maximized at a Zn content of 0.15 wt.%. Compared to the sample without the Zn, the tensile strength was increased by 21.29%, and the elongation rate was increased by 46%. An analysis showed that the alloy has good comprehensive mechanical properties when the Zn content is 0.15 wt.%. [ABSTRACT FROM AUTHOR]

Babbitt alloy is a bearing material with excellent properties, including good anti-friction wear resistance, embeddedness, corrosion, and compliance, as well as sufficient bearing capacity. However, with the development of engines to have high speed and heavy load, the use of Babbitt alloy as a bearing material exposes its weaknesses of low bearing capacity, insufficient fatigue strength and a sharp decline in mechanical properties with an increase in working temperature. Therefore, its application scope is gradually narrowed and subject to certain limitations. Improving the tensile strength and wear resistance of tin-based Babbitt alloy is of great significance to expanding its application. In this study, tin-based Babbitt alloy was taken as the main research object; the particle size, microstructure, mechanical properties, and friction were systematically studied after the single addition of Y-Cu composite in tin-based Babbitt alloy liquid. The wear performance and the strengthening, toughening and wear mechanisms of tin-based Babbitt alloy were investigated under the action of Y in order to prepare a high-performance tin-based Babbitt alloy for bimetallic bearing. It was found that when rare-earth Y was added to the Babbitt alloy body, the wear properties were greatly improved. [ABSTRACT FROM AUTHOR]

Sustainable spatial planning increasingly emphasizes the protection and restoration provided by nature to human welfare, yet scientifically assessing and managing the societal utilization status of natural ecological assets (EAs) remains a challenge. This study introduces a novel classification of EAs based on the degree of dependency of human societies, and establishes an assessment framework for the spatial utilization status of EAs, incorporating indicators related to "pattern-quality-supply-demand- risk". These indicators are integrated into the construction of ecological security patterns to optimize the management of EAs. Validated in Changxing County, Zhejiang Province, China, key findings include: (1) In 2020, the EAs of Changxing provided a value of CNY 77.936 billion, with livable climate assets dominating and carbon assets least prevalent. (2) Urban development has led to EA loss, with the most significant losses in high-supply areas and the highest loss risks in areas with scarce EAs, yet maintaining an overall balance of supply and demand. (3) In 2020, the total area of EA sources in Changxing was 487.34 km2, accounting for 34% of the total land area, with 42.34% classified as high-security zones and 11.21% as high-alert zones. This study proposes an approach to ecological spatial optimization management that integrates the spatial utilization status of EAs, providing planners with practical tools and illustrative cases for seamlessly incorporating localized ecological elements into spatial planning. Our research applies to regions facing challenges related to EA loss and striving for sustainable development, offering strategies for ecological restoration, compensation, and optimization management. [ABSTRACT FROM AUTHOR]

Developing high-loading spin-polarized p-block-element-based single-atom catalysts (p-SACs) upon defect-free substrates for various chemical reactions wherein spin selection matters is generally considered a formidable challenge because of the difficulty of creating high densities of underpinning stable defects and the delocalized electronic features of p-block elements. Here our first-principles calculations establish that the defect-free rutile TiO2(110) wide-bandgap semiconducting anchoring support can stabilize and localize the wavefunctions of p-block metal elements (Sb and Bi) via strong ionic bonding, forming spin-polarized p-SACs. Cooperated by the underlying d-block Ti atoms via a delicate spin donation-back-donation mechanism, the p-block single-atom reactive center Sb(Bi) exhibits excellent catalysis for spin-triplet O2 activation and CO oxidation in alignment with Wigner's spin selection rule, with a low rate-limiting reaction barrier of ∼0.6 eV. This work is crucial in establishing high-loading reactive centers of high-performance p-SACs for various important physical processes and chemical reactions, especially wherein the spin degree of freedom matters, i.e., spin catalysis. [ABSTRACT FROM AUTHOR]

The transportation sector plays a pivotal role in China's efforts to achieve CO2 reduction targets. As the capital of China, Beijing has the responsibility to lead the era's demand for low-carbon development and provide replicable and scalable low-carbon transportation development experience and knowledge for other cities in China. This study calculates the CO2 emissions of the transportation sector in Beijing from 1999 to 2019, constructs an extended STIRPAT model (population, affluence, technology, and efficiency), employs ridge regression to mitigate the effects of multicollinearity among the eight indicators, reveals the extent and direction of influence exerted by different indicators on CO2 emissions, and predicts the development trends, peak times, and quantities of transportation CO2 emissions in nine scenarios for Beijing from 2021 to 2035. Finally, adaptive low-carbon planning strategies are proposed for Beijing pertaining to population size and structure, industrial layout optimization, urban functional reorganization and adjustment, transportation infrastructure allocation, technological research and promotion, energy transition planning, and regional collaborative development. The results are as follows: (1) The total amount of CO2 emissions from Beijing's transportation sector exhibits a trend of gradually stabilizing in terms of growth, with a corresponding gradual deceleration in the rate of increase. Kerosene, gasoline, and diesel are the main sources of transportation CO2 emissions in Beijing, with an annual average proportion of 95.78%. (2) The degree of influence of the indicators on transportation CO2 emissions, in descending order, is energy intensity, per capita GDP, population size, GDP by transportation sector, total transportation turnover, public transportation efficiency, possession of private vehicles, and clean energy structure. Among them, the proportion of clean energy structure and public transportation efficiency are negatively correlated with transportation CO2 emissions, while the remaining indicators are positively correlated. (3) In the nine predicted scenarios, all scenarios, except scenario 2 and scenario 4, can achieve CO2 emission peaks by 2030, while scenarios 7 and 9 can reach the peak as early as 2025. (4) The significant advancement and application of green carbon reduction technologies have profound implications, as they can effectively offset the impacts of population, economy, and efficiency indicators under extensive development. Effective population control, sustainable economic development, and transportation efficiency improvement are viable means to help achieve carbon peaking and peak value in the transportation sector. [ABSTRACT FROM AUTHOR]