Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 117
Filtrar
1.
Chem Asian J ; : e202400411, 2024 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-38719729

RESUMO

In this paper, we have established an operationally convenient protocol for the rapid construction of polysubstituted methyleneindene and quinoline derivatives under mild conditions. This new synthetic method is achieved through the conversion of acetyl-substituted methylenecyclopropanes with TsOH·H2O and ortho-amino-substituted methylenecyclopropanes with aromatic aldehyde and TsOH·H2O, respectively. A variety of transformations of the obtained products was demonstrated. The plausible reaction mechanisms were also proposed.

2.
J Am Chem Soc ; 2024 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-38723144

RESUMO

The transformation of two-dimensional (2D) covalent-organic frameworks (COFs) into three-dimensions (3D) is synthetically challenging, and it is typically addressed through interlayer cross-linking of alkene or alkyne bonds. Here, we report the first example of the chemical reconstruction of a 2D COF to a 3D COF with a complete lattice rearrangement facilitated by base-triggered boron hybridization. This chemical reconstruction involves the conversion of trigonal boronate ester linkages to tetrahedral anionic spiroborate linkages. This transformation reticulates the coplanar, closely stacked square cobalt(II) phthalocyanine (PcCo) units into a 3D perpendicular arrangement. As a result, the pore size of COFs expands from 2.45 nm for the initial 2D square lattice (sql) to 3.02 nm in the 3D noninterpenetrated network (nbo). Mechanistic studies reveal a base-catalyzed boronate ester protodeboronation pathway for the formation of the spiroborate structure.

3.
Int J Neurosci ; : 1-10, 2024 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-38618672

RESUMO

Purpose: To examine effects of aerobic exercise interventions on brain via the structural Magnetic Resonance Imaging (MRI), as well as functional change during working memory (WM) task using fMRI in deaf children.Method: The study applied a cluster randomized controlled design. Twelve deaf children in the intervention group were required to complete an eleven-week aerobic exercise intervention, while other twelve age and gender matched deaf children in the control group were required to keep their normal daily life. Task fMRI images of each participant were acquired in the baseline and post intervention period. The surface-based morphometry (SBM) analysis and functional activation analysis were employed to probe the effects of 11-week aerobic exercise on cerebral structural and functional in deaf children, respectively.Results: The 11-week aerobic exercise intervention did not change brain structure in deaf children. However, behavior performance (reaction time and mean accuracy rate) presented significant improvements after the 11-week aerobic exercise intervention. Compared to the control group, the intervention group showed decreased reaction time in the 2-back (p < 0.001) and 2-0 back (p < 0.001), and increased mean accuracy rate during 2-back (p = 0.034). Furthermore, enhanced brain activations in the left supplementary motor cortex (p < 0.05, FDR-corrected) and left paracentral lobule (p < 0.05, FDR-corrected) were observed in the intervention group.Conclusion: 11-week aerobic exercise intervention may not be able to modulate brain structure in deaf children, but may have significantly positive effects on behavior performance and brain functional activation during WM task.

4.
J Pain Res ; 17: 1313-1326, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38563035

RESUMO

Background: Intervertebral disc degeneration (IVDD) is the main cause of low back pain (LBP), but the specific regulatory factors, pathways and specific molecular mechanisms remain unclear. Methods: We identified and quantitatively analyzed Pfirrmann Grade II (n=3) and Pfirrmann Grade IV (n=3) pulposus samples via MRI. The differential abundance of proteins in the samples was determined and quantitatively analyzed by relative and absolute quantitative analysis of the isotope marker levels combined with the liquid chromatography-tandem mass spectrometry (LC‒MSMS/MS). Results: A total of 70 proteins (30 significantly increased proteins (> 1.2-fold change) and 40 significantly decreased proteins (< 0.8-fold change)) showed different levels among the groups. Kyoto Encyclopedia of Genes and Genomes and Gene Ontology (GO) enrichment analyses and Western blot analysis showed that CYCS, RAC1, and PSMD14 may play important roles in IVDD and that Epstein‒Barr virus infection, viral myocarditis, colorectal cancer, nonalcoholic fatty liver disease (NAFLD) and amyotrophic lateral sclerosis (ALS) are the main pathways involved in IVDD. Conclusion: CYCS, RAC1 and PSMD14 may play important roles in IVDD, and Epstein‒Barr virus infection, viral myocarditis, colorectal cancer, NAFLD and ALS may be the main pathways involved in IVDD.

5.
Clin Rheumatol ; 43(5): 1675-1682, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38538907

RESUMO

OBJECTIVE: This study aimed to evaluate the value of machine learning models (ML) based on MRI radiomics in diagnosing early parotid gland injury in primary Sjögren's syndrome (pSS). METHODS: A total of 164 patients (114 in the training cohort and 50 in the testing cohort) with pSS (n=82) or healthy controls (HC) (n=82) were enrolled. Itksnap software was used to perform two-dimensional segmentation of the bilateral parotid glands on T1-weighted (T1WI) and fat-suppressed T2-weighted imaging (fs-T2WI) images. A total of 1548 texture features of the parotid glands were extracted using radiomics software. A radiomics score (Radscore) was constructed and calculated. A t-test was used to compare the Radscore between the two groups. Finally, five machine learning models were trained and tested to identify early pSS parotid injury, and the performance of the machine learning models was evaluated by calculating the acceptance operating curve (ROC) and other parameters. RESULTS: The Radscores between the pSS and HC groups showed significant statistical differences (p<0.001). Among the five machine learning models, the Extra Trees Classifier (ETC) model performed high predictive efficacy in identifying early pSS parotid injury, with an AUC of 0.87 in the testing set. CONCLUSION: MRI radiomics-based machine learning models can effectively diagnose early parotid gland injury in primary Sjögren's syndrome.


Assuntos
Glândula Parótida , Síndrome de Sjogren , Humanos , Glândula Parótida/diagnóstico por imagem , Síndrome de Sjogren/diagnóstico por imagem , Radiômica , Imageamento por Ressonância Magnética/métodos , Aprendizado de Máquina , Estudos Retrospectivos
6.
Acc Chem Res ; 57(8): 1111-1122, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38372967

RESUMO

ConspectusMolecular polyhedral cages, notable for their enclosed inner cavities, can possess varying degrees of symmetry, spanning from regular Platonic polyhedra to lower symmetry forms that may display chirality. Crafting chiral molecular cages typically involves using building blocks containing stereogenic elements or arranging achiral components in a manner that lacks mirror and inversion symmetries. Achieving precise control over their chirality poses both significance and challenges.In this Account, we present an overview of our research endeavors in the realm of chiral molecular polyhedral cages, drawing inspiration from Buckminster Fuller's "Face-Rotating Polyhedra (FRP)". Mathematically, FRP introduce a unique form of chirality distinguished by a rotating pattern around the center of each face, setting it apart from regular polyhedra.Molecular FRP can be constructed using two types of facial building blocks. The first includes rigid, planar molecules such as truxene and triazatruxene, which exhibit either clockwise or counterclockwise rotations in two dimensions. The second category involves propeller-like molecules, e.g., tetraphenylethylene, 1,2,3,4,5-penta(4-phenylaldehyde)pyrrole, and tridurylborane, displaying dynamic stereochemistry.The synthesis of FRP may potentially yield a diverse array of stereoisomers. Achieving high stereoselectivity becomes feasible through the selection of building blocks with specific substitution patterns and rigidity. Prominent noncovalent repulsive forces within the resulting cages often play a pivotal role in the dynamic covalent assembly process, ultimately leading to the formation of thermodynamically stable FRP products.The capacity to generate a multitude of stereoisomers, combined with the integration of chiral vertices, has facilitated investigations into phenomena such as chiral self-sorting and the "sergeant and soldiers" chiral amplification effect in FRP. Even the inclusion of one chiral vertex significantly impacts the stereochemical configuration of the entire cage. While many facial building blocks establish a stable rotational pattern in FRP, other units, such as tridurylborane, can dynamically transition between P and M configurations within the cage structures. The kinetic characteristics of such stereolabile FRP can be elucidated through physicochemical investigations.Our research extends beyond the FRP concept to encompass mathematical analysis of these structures. Graph theory, particularly the coloring problem, sheds light on the intricate facial patterns exhibited by various FRP stereoisomers and serves as an efficient tool to facilitate the discovery of novel FRP structures. This approach offers a fresh paradigm for designing and analyzing chiral molecular polyhedral cages, showcasing in our work the synergy between mathematics and molecular design.

7.
Heliyon ; 10(2): e24548, 2024 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-38304777

RESUMO

Aim: The study aimed to explore the relationship between urate deposition and surrounding atherosclerotic plaques, and to confirm the contribution of urate deposition to the development of coronary atherosclerosis. Methods and results: The present study employed Dual-energy CT (DECT) material separation technology through calcium score scan to access the presence of MSU crystal deposition in coronary atherosclerotic plaques in patients with clinically suspected coronary heart diseases undergoing DECT. DECT showed that among 872 patients, 441 had plaques in coronary arteries; the incidence of plaque was 50.6 %. The patients were divided in the atherosclerotic plaque vs. non-plaque groups. There were significant differences in age, sex, blood pressure, blood glucose, serum creatinine, and history of gout and hyperuricemia between the plaque and non-plaque groups (all P < 0.05). Among the patients with coronary plaques, there were 348 patients (78.9 %) with simple atherosclerotic plaque (AP), 8 (1.8 %) with simple urate depositions (UD), and 85 (19.3 %) with urate depositions and atherosclerotic plaques (UDAP). The multivariable analysis showed that urate deposition was independently associated with plaques after adjustment for age, sex, blood pressure, blood glucose, serum creatinine, history of gout, and history of hyperuricemia (OR = 13.69, 95%CI: 7.53-22.95, P = 0.035). UPAP patients had significantly higher coronary calcium scores than AP patients [210.1 (625.2) AU vs 58.2 (182.5) AU, P < 0.001] Urate deposition (16.7 mm3) positively correlated with plaque calcification (73.8 mm³) in UPAP patients (r = 0.325, P < 0.001). Conclusion: Patients with gout or a history of hyperuricemia were more likely to exhibit UDAP. Urate deposition was independently associated with plaques.

8.
Nat Mater ; 23(4): 570-576, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38297141

RESUMO

Soft building blocks, such as micelles, cells or soap bubbles, tend to adopt near-spherical geometry when densely packed together. As a result, their packing structures do not extend beyond those discovered in metallic glasses, quasicrystals and crystals. Here we report the emergence of two Frank-Kasper phases from the self-assembly of five-fold symmetric molecular pentagons. The µ phase, an important intermediate in superalloys, is indexed in soft matter, whereas the ϕ phase exhibits a structure distinct from known Frank-Kasper phases in metallic systems. We find a broad size and shape distribution of self-assembled mesoatoms formed by molecular pentagons while approaching equilibrium that contribute to the unique packing structures. This work provides insight into the manipulation of soft building blocks that deviate from the typical spherical geometry and opens avenues for the fabrication of 'soft alloy' structures that were previously unattainable in metal alloys.

9.
Chem Soc Rev ; 53(4): 1892-1914, 2024 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-38230701

RESUMO

Molecular assembly is the process of organizing individual molecules into larger structures and complex systems. The self-assembly approach is predominantly utilized in creating artificial molecular assemblies, and was believed to be the primary mode of molecular assembly in living organisms as well. However, it has been shown that the assembly of many biological complexes is "catalysed" by other molecules, rather than relying solely on self-assembly. In this review, we summarize these catalysed-assembly (catassembly) phenomena in living organisms and systematically analyse their mechanisms. We then expand on these phenomena and discuss related concepts, including catalysed-disassembly and catalysed-reassembly. Catassembly proves to be an efficient and highly selective strategy for synergistically controlling and manipulating various noncovalent interactions, especially in hierarchical molecular assemblies. Overreliance on self-assembly may, to some extent, hinder the advancement of artificial molecular assembly with powerful features. Furthermore, inspired by the biological catassembly phenomena, we propose guidelines for designing artificial catassembly systems and developing characterization and theoretical methods, and review pioneering works along this new direction. Overall, this approach may broaden and deepen our understanding of molecular assembly, enabling the construction and control of intelligent assembly systems with advanced functionality.

10.
Gait Posture ; 108: 307-312, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38199089

RESUMO

BACKGROUND: Gait imbalance has been reported in overweight individuals and could further impair their mobility and quality of life. As the feet are the most distal part of the body and sensitively interface with external surroundings, evaluating the plantar pressure distribution can provide critical insights into their roles in regulating gait balance control. Therefore, the purpose of this study was to evaluate the effect of body weight and different gait speeds on the plantar pressure distribution and whole-body center of mass (COM) motion during walking. METHODS: Eleven overweight individuals (OB) and 13 non-overweight individuals (NB) walked on a 10-meter walkway at three speed conditions (preferred, 80% and 120% of preferred speed). Gait balance was quantified by the mediolateral COM sway. Plantar pressure data were obtained using wireless pressure-sensing insoles that were inserted into a pair of running shoes. Analysis of variance models were used to examine the effect of body size, gait speeds, or their interactions on peak mediolateral COM and peak plantar pressure during walking. RESULTS: Significant group effects of peak plantar pressure under the lateral forefoot (P = 0.03), lateral midfoot (P = 0.02), and medial heel (P = 0.02) were observed. However, the mediolateral COM motion and spatiotemporal gait parameters only revealed significant speed effects. SIGNIFICANCE: Findings from this study indicated that overweight individuals exhibited increased plantar pressure under the lateral aspect of the foot, particularly during the late stance phase of walking, in an effort to maintain a comparable mediolateral COM motion to that of non-overweight individuals. Such elevated pressure in overweight individuals may potentially increase the risk of musculoskeletal pathology in the long term. The identified patterns are noteworthy as they have practical implications for designing targeted interventions and improving the overall health of individuals with a high BMI.


Assuntos
Sobrepeso , Qualidade de Vida , Humanos , Pressão , Caminhada/fisiologia , Marcha/fisiologia
11.
Small ; 20(4): e2304968, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37715278

RESUMO

The contrast agents and tumor treatments currently used in clinical practice are far from satisfactory, due to the specificity of the tumor microenvironment (TME). Identification of diagnostic and therapeutic reagents with strong contrast and therapeutic effect remains a great challenge. Herein, a novel carbon dot nanozyme (Mn-CD) is synthesized for the first time using toluidine blue (TB) and manganese as raw materials. As expected, the enhanced magnetic resonance (MR) imaging capability of Mn-CDs is realized in response to the TME (acidity and glutathione), and r1 and r2 relaxation rates are enhanced by 224% and 249%, respectively. In addition, the photostability of Mn-CDs is also improved, and show an efficient singlet oxygen (1 O2 ) yield of 1.68. Moreover, Mn-CDs can also perform high-efficiency peroxidase (POD)-like activity and catalyze hydrogen peroxide to hydroxyl radicals, which is greatly improved under the light condition. The results both in vitro and in vivo demonstrate that the Mn-CDs are able to achieve real-time MR imaging of TME responsiveness through aggregation of the enhanced permeability and retention effect at tumor sites and facilitate light-enhanced chemodynamic and photodynamic combination therapies. This work opens a new perspective in terms of the role of carbon nanomaterials in integrated diagnosis and treatment of diseases.


Assuntos
Neoplasias , Fotoquimioterapia , Humanos , Cloreto de Tolônio , Manganês , Espécies Reativas de Oxigênio , Carbono , Peróxido de Hidrogênio , Imageamento por Ressonância Magnética , Microambiente Tumoral , Linhagem Celular Tumoral
12.
Food Chem ; 432: 137195, 2024 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-37625298

RESUMO

In this work, pomelo peel was fermented by Aspergillus oryzae CGMCC23295 to enhance its anti-diabetic properties. Results showed the total phenolic and flavonoids contents, ferric reducing antioxidant power (FRAP), scavenging capacities against 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydroxyl radicals, as well as inhibitory abilities against α-amylase and α-glucosidase of pomelo peel were increased and fermentation for 8 days was the best. Additionally, the fermented sample could also enhance the glucose consumption and glycogen of HepG2 cell. Based on UPLC-MS/MS analysis, binding energy calculation, concentration determination and IC50 measurement, purpurin, apigenin, genistein, and paxilline could be concluded to be the main compounds to enhance the inhibition activities of fermented sample against α-amylase and α-glucosidase. Furthermore, computational studies were performed to reveal the the binding site and molecular interactions between paxilline and α-amylase, as well as purpurin and α-glucosidase. These findings provide a base for the utilization and valorization of pomelo peels as functional food additives by fermentation.


Assuntos
Aspergillus oryzae , Fermentação , Cromatografia Líquida , Espectrometria de Massas em Tandem , alfa-Glucosidases
13.
Food Chem X ; 20: 101018, 2023 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-38144749

RESUMO

Nitrogen application delays rice quality deterioration due to changes in its pasting characteristics; however, the underlying mechanisms remain unclear. Using a label-free quantitative proteomics approach, we identified differentially expressed proteins (DEPs) during storage in paddy rice treated with different nitrogen levels. On combining the changes in physiological indicators, high-nitrogen treatment was found to downregulate ß-1,3-glucanase, reduce the decomposition of cell wall components, downregulate three proteins involved in starch metabolism, decrease the range of the amylose content and increase the range of the amylopectin, upregulate three proteins related to the lysosomal pathway, and enhance glutelin degradation. In addition, it upregulated three proteins related to flavonoid synthesis, which enhanced the stress response ability of rice, thereby contributing to the stability of biological macromolecules. The discovery of these key DEPs provides potential targets for further control over the deterioration of crop seed storage quality.

14.
Biomed Opt Express ; 14(11): 5921-5931, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-38021116

RESUMO

Autoantibodies against New York esophageal squamous cell cancer 1 (NY-ESO-1) play a crucial role in the diagnosis of esophageal cancer. In this work, a surface plasmonic tilted fiber Bragg grating (TFBG) biosensor is proposed for the detection of NY-ESO-1 antibody, as well as the investigation of the hook effect (which refers to the false negative result in some immunoassays when the concentration of antibodies in the sample is very high) during biomolecular binding between NY-ESO-1 antigen and antibody. The biosensor is made by an 18° TFBG coated with a 50-nm-thick gold film over the fiber surface together with NY-ESO-1 antigens attached to the metallic surface serving as bio-receptors. This biosensor can provide a limit of detection at a concentration of 2 × 10-7 µg/ml with a good linearity in the range from 2 × 10-7 to 2 × 10-5 µg/ml. For a concentration higher than 2 × 10-3 µg/ml, the performance of the sensor probe is reduced owing to the hook effect. Furthermore, experimental results have also demonstrated the repeatability of the proposed biosensor. This proposed biosensor features label-free, compactness, and fast response, which could be potentially applied in the diagnosis of esophageal cancer.

15.
Artigo em Inglês | MEDLINE | ID: mdl-38015666

RESUMO

This paper introduces the Long Short-Term Memory with Dual-Stage Attention (LSTM-MSA) model, an approach for analyzing electromyography (EMG) signals. EMG signals are crucial in applications like prosthetic control, rehabilitation, and human-computer interaction, but they come with inherent challenges such as non-stationarity and noise. The LSTM-MSA model addresses these challenges by combining LSTM layers with attention mechanisms to effectively capture relevant signal features and accurately predict intended actions. Notable features of this model include dual-stage attention, end-to-end feature extraction and classification integration, and personalized training. Extensive evaluations across diverse datasets consistently demonstrate the LSTM-MSA's superiority in terms of F1 score, accuracy, recall, and precision. This research provides a model for real-world EMG signal applications, offering improved accuracy, robustness, and adaptability.


Assuntos
Aprendizado Profundo , Antebraço , Humanos , Eletromiografia , Gestos , Extremidade Superior
16.
J Am Chem Soc ; 145(42): 23352-23360, 2023 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-37824718

RESUMO

Soft porous crystals combine flexibility and porosity, allowing them to respond structurally to external physical and chemical environments. However, striking the right balance between flexibility and sufficient rigidity for porosity is challenging, particularly for molecular crystals formed by using weak intermolecular interactions. Here, we report a flexible oxygen-bridged prismatic organic cage molecule, Cage-6-COOH, which has three pillars that exhibit "hinge-like" rotational motion in the solid state. Cage-6-COOH can form a range of hydrogen-bonded organic frameworks (HOFs) where the "hinge" can accommodate a remarkable 67° dihedral angle range between neighboring units. This stems both from flexibility in the noncovalent hydrogen-bonding motifs in the HOFs and the molecular flexibility in the oxygen-linked cage hinge itself. The range of structures for Cage-6-COOH includes two topologically complex interpenetrated HOFs, CageHOF-2α and CageHOF-2ß. CageHOF-2α is nonporous, while CageHOF-2ß has permanent porosity and a surface area of 458 m2 g-1. The flexibility of Cage-6-COOH allows this molecule to rapidly transform from a low-crystallinity solid into the two crystalline interpenetrated HOFs, CageHOF-2α and CageHOF-2ß, under mild conditions simply by using acetonitrile or ethanol vapor, respectively. This self-healing behavior was selective, with the CageHOF-2ß structure exhibiting structural memory behavior.

17.
Sensors (Basel) ; 23(17)2023 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-37688031

RESUMO

This article reviews recent research progress on the annealing effects on polymer optical fibers (POFs), which are of great importance for inscription, stability and sensing applications of fiber Bragg gratings (FBGs) in POFs due to their unique properties related to polymer molecular chains. In this review, the principle of annealing to reduce frozen-in stress in POFs drawing and different annealing timings are firstly summarized. Then, the annealing methods for POFs are introduced under several different conditions (temperature, humidity, strain, stress and solution). Afterwards, the principle of FBGs and several inscription techniques are reported. Subsequently, the annealing effects on the properties of POFs and polymer optical fiber Bragg gratings (POFBGs) quality are discussed. Finally, the influence of annealing on POFBG sensitivity is summarized. Overall, this paper provides a comprehensive overview of annealing techniques and their impact on both POFs and POFBGs. We hope that it will highlight the important progress made in this field.

18.
Zhongguo Gu Shang ; 36(9): 896-900, 2023 Sep 25.
Artigo em Chinês | MEDLINE | ID: mdl-37735085

RESUMO

OBJECTIVE: To investigate the clinical efficacy of acrylic cement (PMMA) mixed with calcium sulfate combined with percutaneous kyphoplasty (PKP) in the treatment of osteoporotic fracture (OVCF). METHODS: The clinical data of 191 patients with OVCF treated with PKP from January 2020 to March 2021 were retrospectively analyzed. Among them, 82 patients with 94 vertebral bodies were treated with PMMA mixed with calcium sulfate as the observation group, and 109 patients with 125 vertebral bodies were treated with pure PMMA as the control group. Among the 82 patients in the observation group, there were 16 males and 66 females, with a mean age of (75.35±11.22) years old, including 36 thoracic vertebrae and 58 lumbar vertebrae. In the control group, there were 109 patients, 22 males and 87 females, with an average age of (74.51±9.21) years old, including 63 thoracic vertebrae and 62 lumbar vertebrae. The visual analog scale (VAS) before operation and 1 day, 3 months and 1 year after operation were calculated. The Oswestry disability index (ODI), Cobb's angle, vertebral body height and the probability of postoperative bone cement leakage were used to analyze the efficacy of the two groups. RESULTS: All the patients were followed up for more than one year. Compared with the control group, there was no significant difference in operation time, bleeding volume and bone cement injection volume between the two groups(P>0.05), while the leakage rate of bone cement was significantly lower in the observation group (P<0.05). In addition, there was no significant difference in VAS, ODI, Cobb angle, and vertebral body height between the two groups before operation, and 1 day, 3 months, and 1 year after operation (P>0.05), but each index was improved compared with that before operation (P<0.05). CONCLUSION: PMMA mixed with calcium sulfate has equivalent efficacy in treating OVCF than PMMA alone, but can effectively reduce the probability of cement leakage.


Assuntos
Cifoplastia , Fraturas por Osteoporose , Feminino , Masculino , Humanos , Idoso , Idoso de 80 Anos ou mais , Pessoa de Meia-Idade , Polimetil Metacrilato , Sulfato de Cálcio/uso terapêutico , Fraturas por Osteoporose/cirurgia , Cimentos Ósseos/uso terapêutico , Estudos Retrospectivos , Vértebras Lombares/cirurgia
19.
J Am Chem Soc ; 145(32): 17795-17804, 2023 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-37527407

RESUMO

The manipulation of chirality in molecular entities that rapidly interconvert between enantiomeric forms is challenging, particularly at the supramolecular level. Advances in controlling such dynamic stereochemical systems offer opportunities to understand chiral symmetry breaking and homochirality. Herein, we report the synthesis of a face-rotating tetrahedron (FRT), an organic molecular cage composed of tridurylborane facial units that undergo stereomutations between enantiomeric trefoil propeller-like conformations. After resolution, we show that the racemization barrier of the enantiopure FRT can be regulated in situ through the reversible binding of fluoride anions onto the tridurylborane moieties. Furthermore, the addition of an enantiopure phenylethanol to the FRT can effectively induce chirality of the molecular cage by preferentially binding to one of its enantiomeric conformers. This study presents a new paradigm for controlling dynamic chirality in supramolecular systems, which may have implications for asymmetric synthesis and dynamic stereochemistry.

20.
Chemistry ; 29(64): e202302420, 2023 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-37615406

RESUMO

Crystalline porous organic salts (CPOS) are a subclass of molecular crystals. The low solubility of CPOS and their building blocks limits the choice of crystallisation solvents to water or polar alcohols, hindering the isolation, scale-up, and scope of the porous material. In this work, high throughput screening was used to expand the solvent scope, resulting in the identification of a new porous salt, CPOS-7, formed from tetrakis(4-sulfophenyl)methane (TSPM) and tetrakis(4-aminophenyl)methane (TAPM). CPOS-7 does not form with standard solvents for CPOS, rather a hydrated phase (Hydrate2920) previously reported is isolated. Initial attempts to translate the crystallisation to batch led to challenges with loss of crystallinity and Hydrate2920 forming favorably in the presence of excess water. Using acetic acid as a dehydrating agent hindered formation of Hydrate2920 and furthermore allowed for direct conversion to CPOS-7. To allow for direct formation of CPOS-7 in high crystallinity flow chemistry was used for the first time to circumvent the issues found in batch. CPOS-7 and Hydrate2920 were shown to have promise for water and CO2 capture, with CPOS-7 having a CO2 uptake of 4.3 mmol/g at 195 K, making it one of the most porous CPOS reported to date.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...