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1.
BMC Musculoskelet Disord ; 25(1): 484, 2024 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-38898448

RESUMO

BACKGROUND: Spinal fractures in patients with ankylosing spondylitis (AS) mainly present as instability, involving all three columns of the spine, and surgical intervention is often considered necessary. However, in AS patients, the significant alterations in bony structure and anatomy result in a lack of identifiable landmarks, which increases the difficulty of pedicle screw implantation. Therefore, we present the clinical outcomes of robotic-assisted percutaneous fixation for thoracolumbar fractures in patients with AS. METHODS: A retrospective review was conducted on a series of 12 patients diagnosed with AS. All patients sustained thoracolumbar fractures between October 2018 and October 2022 and underwent posterior robotic-assisted percutaneous fixation procedures. Outcomes of interest included operative time, intra-operative blood loss, complications, duration of hospital stay and fracture union. The clinical outcomes were assessed using the visual analogue scale (VAS) and Oswestry Disability Index (ODI). To investigate the achieved operative correction, pre- and postoperative radiographs in the lateral plane were analyzed by measuring the Cobb angle. RESULTS: The 12 patients had a mean age of 62.8 ± 13.0 years and a mean follow-up duration of 32.7 ± 18.9 months. Mean hospital stay duration was 15 ± 8.0 days. The mean operative time was 119.6 ± 32.2 min, and the median blood loss was 50 (50, 250) ml. The VAS value improved from 6.8 ± 0.9 preoperatively to 1.3 ± 1.0 at the final follow-up (P < 0.05). The ODI value improved from 83.6 ± 6.1% preoperatively to 11.8 ± 6.6% at the latest follow-up (P < 0.05). The average Cobb angle changed from 15.2 ± 11.0 pre-operatively to 8.3 ± 7.1 at final follow-up (P < 0.05). Bone healing was consistently achieved, with an average healing time of 6 (5.3, 7.0) months. Of the 108 screws implanted, 2 (1.9%) were improperly positioned. One patient experienced delayed nerve injury after the operation, but the nerve function returned to normal upon discharge. CONCLUSION: Posterior robotic-assisted percutaneous internal fixation can be used as an ideal surgical treatment for thoracolumbar fractures in AS patients. However, while robot-assisted pedicle screw placement can enhance the accuracy of pedicle screw insertion, it should not be relied upon solely.


Assuntos
Fixação Interna de Fraturas , Vértebras Lombares , Procedimentos Cirúrgicos Robóticos , Fraturas da Coluna Vertebral , Espondilite Anquilosante , Vértebras Torácicas , Humanos , Fraturas da Coluna Vertebral/cirurgia , Fraturas da Coluna Vertebral/diagnóstico por imagem , Fraturas da Coluna Vertebral/etiologia , Masculino , Pessoa de Meia-Idade , Vértebras Torácicas/cirurgia , Vértebras Torácicas/lesões , Vértebras Torácicas/diagnóstico por imagem , Feminino , Estudos Retrospectivos , Espondilite Anquilosante/cirurgia , Espondilite Anquilosante/complicações , Vértebras Lombares/cirurgia , Vértebras Lombares/lesões , Vértebras Lombares/diagnóstico por imagem , Procedimentos Cirúrgicos Robóticos/métodos , Fixação Interna de Fraturas/métodos , Fixação Interna de Fraturas/instrumentação , Resultado do Tratamento , Idoso , Duração da Cirurgia , Tempo de Internação , Parafusos Pediculares , Adulto , Perda Sanguínea Cirúrgica/estatística & dados numéricos , Seguimentos
2.
Angew Chem Int Ed Engl ; : e202411815, 2024 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-39032126

RESUMO

Developing functional adhesives combining strong adhesion, good recyclability and diverse harsh-condition adaptability is a grand challenge. Here, we introduce a general dendritic molecule doping strategy to activate commercial polymers into a new family of supramolecular adhesives integrating high adhesion strength, ultralow temperature, water resistant and multi-reusable properties. Our method involves rational design of a new rigid-flexible coupled dendritic molecule - M4C8OH as a versatile dopant, while simple M4C8OH doping into commercial polymers can modulate internal and external non-covalent interaction to enable H-bonding enhanced interchain cross-linking for tough cohesion along with enhanced interphase interaction. This endows 20 wt% M4C8OH-doped polycaprolactone (PCL) adhesives (PCL-M4C8OH) with improved adhesion strength on various substrates with the maximum increase up to 2.87 times that of PCL. In particular, the adhesion strengths of PCL-M4C8OH on polymethyl methacrylate at 25 °C and -196 °C reach 4.67 and 3.58 MPa - 1.9 and 2.3 times those of PCL and superior to diverse commercial adhesives and most reported adhesives. PCL-M4C8OH also displays markedly-improved multi-usability and tolerance against ultralow temperature and diverse wet environments. Mechanism studies reveal the crucial role of  M4C8OH molecular structures toward superior adhesion. Our method can be expanded to other polymer matrices, yielding diverse new supramolecular adhesives.

3.
Angew Chem Int Ed Engl ; 63(23): e202401957, 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38526332

RESUMO

Here, we build a tunable multipolar conjugated polymer framework platform via pore wall chemistry to probe the role of electronic structure engineering in improving the Li+ conduction by theoretical studies. Guided by theoretical prediction, we develop a new cyano-vinylene-linked multipolar polymer framework namely CNF-COF, which can act as efficient ion sieves to modify solid polymer electrolytes to simultaneously tune Li+ migration and stable Li anodes for long-lifespan all-solid-state (ASS) Li metal batteries at high rate. The dual-decoration of cyano and fluorine groups in CNF-COF favorably regulates electronic structure via multipolar donor-acceptor electronic effects to afford proper energy band structure and abundant electron-rich sites for enhanced oxidative stability, facilitated ion-pair dissociation and suppressed anion movements. Thus, the CNF-COF incorporation into poly (ethylene oxide) (PEO) electrolytes not only renders fast selective Li+ transport but also facilitates the Li dendrite suppression. Specifically, the constructed PEO composite electrolyte with an ultra-low CNF-COF content of only 0.5 wt % is endowed with a wide electrochemical window, a high ionic conductivity of 0.634 mS cm-1 at 60 °C and a large Li+ transference number of 0.81-remarkably outperforming CNF-COF-free counterparts (0.183 mS cm-1 and 0.22). As such, the Li symmetric cell delivers stable Li plating/stripping over 1400 h at 0.1 mA cm-2. Impressively, by coupling with LiFePO4 (LFP) cathodes, the assembled ASS Li battery under 60 °C allows for stable cycling over 2000 cycles at 1 C and over 1000 cycles even at 2 C with a large capacity retention of ~75 %, surpassing most reported ASS Li batteries using PEO-based electrolytes.

4.
Angew Chem Int Ed Engl ; 63(16): e202402349, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38349340

RESUMO

Improving the photoswitching rate and robustness of photochromic molecules in bulk solids is paramount for practical applications but remains an on-going challenge. Here, we introduce an octupolar design paradigm to develop a new family of visible light organic photoswitches, namely multi-branched octupolar Stenhouse Adducts (MOPSAs) featuring a C3-symmetrical A3-(D-core) architecture with a dipolar donor-acceptor (D-A) photochrome in each branch. Our design couples multi-dimensional geometric and electronic effects of MOPSAs to enable robust ultrafast reversible photoswitching in bulk polymers. Specifically, the optimal MOPSA (4 wt %) in commercial polyurethane films accomplishes nearly 100 % discoloration in 6 s under visible light with ∼ 100 % thermal-recovery in 17.4 s at 60 °C, while the acquired kinetics constants are 3∼7 times that of dipolar DASA counterpart and 1∼2 orders of magnitude higher than those of reported DASAs in polymers. Importantly, the MOPSA-doped polymer films sustain 500 discoloration/recovery cycles with slow degradation, superior to the existing DASAs in polymers (≤30 cycles). We discover that multi-dipolar coupling in MOPSA enables enhanced polarization and electron delocalization, promoting the rate-determining thermal cyclization, while the branched and non-planar geometry of MOPSA induces large free volume to facilitate the isomerization. This design can be extended to develop spiropyran or azobenzene-based ultrafast photochromic films. The superior photoswitching performance of MOPSAs together with their high-yield and scalable synthesis and facile film processing inspires us to explore their versatile uses as smart inks or labels for time-temperature indicators, optical logic encryption and multi-levelled data encryption.

5.
J Am Chem Soc ; 145(26): 14417-14426, 2023 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-37339431

RESUMO

The development of highly luminescent two-dimensional covalent organic frameworks (COFs) for sensing applications remains challenging. To suppress commonly observed photoluminescence quenching of COFs, we propose a strategy involving interrupting the intralayer conjugation and interlayer interactions using cyclohexane as the linker unit. By variation of the building block structures, imine-bonded COFs with various topologies and porosities are obtained. Experimental and theoretical analyses of these COFs disclose high crystallinity and large interlayer distances, demonstrating enhanced emission with record-high photoluminescence quantum yields of up to 57% in the solid state. The resulting cyclohexane-linked COF also exhibits excellent sensing performance for the trace recognition of Fe3+ ions, explosive and toxic picric acid, and phenyl glyoxylic acid as metabolites. These findings inspire a facile and general strategy to develop highly emissive imine-bonded COFs for detecting various molecules.

6.
Small ; 19(44): e2303903, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37381092

RESUMO

1D van der Waals (vdW) materials have attracted significant interest in recent years due to their giant anisotropic and weak interlayer-coupled characters. More 1D vdW materials are urgently to be exploited for satisfying the practice requirement. Herein, the study of 1D vdW ternary HfSnS3 high-quality single crystals grown via the chemical vapor transport technique is reported. The Raman vibration modes and band structure of HfSnS3 are analyzed via DFT calculations. Its strong in-plane anisotropic is verified by the polarized Raman spectroscopy. The field-effect transistors (FETs) based on the HfSnS3 nanowires demonstrate p-type semiconducting behavior as well as outstanding photoresponse in a broadband range from UV to near-infrared (NIR) with short response times of ≈0.355 ms, high responsivity of ≈11.5 A W-1 , detectivity of ≈8.2 × 1011 , external quantum efficiency of 2739%, excellent environmental stability, and repeatability. Furthermore, a typical photoconductivity effect of the photodetector is illustrated. These comprehensive characteristics can promote the application of the p-type 1D vdW material HfSnS3 in optoelectronics.

7.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 54(1): 203-207, 2023 Jan.
Artigo em Zh | MEDLINE | ID: mdl-36647668

RESUMO

Terahertz waves, the electromagnetic waves in the range of 0.1 to 10 THz, has the advantages of being damage-free, causing no ionizing radiation injury, and being capable of recognizing the fingerprint spectrum of molecular characteristics, thus holding encouraging prospects for wide applications in the field of biomedicine. Terahertz spectrum can be used to identify and characterize biological structures of different levels, from biomolecules such as proteins to cells and tissues, through the spectral signals and/or restored images of the samples. Herein, we summarized the current stomatogical application of and research progress in terahertz spectroscopy and imaging in dentistry, reported the latest research findings, strengths and limitations from three perspectives, tooth anatomical structure, the extent of caries progression, and oral soft tissue, and suggested possible directions for future exploration.


Assuntos
Medicina Bucal , Espectroscopia Terahertz , Espectroscopia Terahertz/métodos , Proteínas/química , Tecnologia
8.
Angew Chem Int Ed Engl ; 62(13): e202217635, 2023 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-36744701

RESUMO

Atomically dispersed Fe was designed on TiO2 and explored as a Janus electrocatalyst for both nitrogen oxidation reaction (NOR) and nitrogen reduction reaction (NRR) in a two-electrode system. Pulsed electrochemical catalysis (PE) was firstly involved to inhibit the competitive hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Excitingly, an unanticipated yield of 7055.81 µmol h-1 g-1 cat. and 12 868.33 µmol h-1 g-1 cat. were obtained for NOR and NRR at 3.5 V, respectively, 44.94 times and 7.8 times increase in FE than the conventional constant voltage electrocatalytic method. Experiments and density functional theory (DFT) calculations revealed that the single-atom Fe could stabilize the oxygen vacancy, lower the energy barrier for the vital rupture of N≡N, and result in enhanced N2 fixation performance. More importantly, PE could effectively enhance the N2 supply by reducing competitive O2 and H2 agglomeration, inhibit the electrocatalytic by-product formation for longstanding *OOH and *H intermediates, and promote the non-electrocatalytic process of N2 activation.

9.
Small ; 18(21): e2200388, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35491241

RESUMO

Efficient detection of aqueous copper ions is of high significance for environmental and human health, since copper is involved in potent redox activity in physiological and pathological processes. Covalent organic frameworks (COFs) have shown advantages in efficient capturing and detecting of copper ions due to their large surface area, robust chemical stability, and high sensitivity, but most of them are hydrophobic, leading to the limitation in sensing copper ions in aqueous media. Herein, the design and synthesis of an sp2 -carbon conjugated COF (sp2 -TPE-COF) are reported with surfactant-assisted water dispersion for detecting traces of copper ions based on the photo-induced electron transfer (PET) mechanism. Importantly, the olefin-linked conjugated backbone of sp2 -TPE-COF works as a signal amplified transducer for metal ion sensing. Notably, it is found that a surfactant-assisted strategy can greatly enhance COF's dispersion in aqueous solution and finely modulate their sensitivity with a significantly improved KSV to 15.15 × 104 m-1 in SDBS (sodium dodecyl benzene sulfonate) solution, the value of which is larger than that of a majority of COF/MOF based sensors for copper ions. This research demonstrates the promise of surfactant modulated fully π-conjugated COFs for sensing applications.


Assuntos
Corantes Fluorescentes , Estruturas Metalorgânicas , Cobre , Humanos , Estruturas Metalorgânicas/química , Tensoativos , Água
10.
Environ Res ; 213: 113637, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35688221

RESUMO

Power plants emit sulfur dioxide (SO2) during combustion, which is typically removed via wet flue gas desulfurization, but this process produces numerous secondary pollutants. Ionic liquids (ILs) can potentially be used to remove SO2, but they suffer from poor mass transfer rates. Hydroxyl ammonium ILs are classical cheap ILs that contain electron-rich O and N sites that favor high absorption capacities. To accelerate mass transfer, two hydroxyl ammonium ILs, triethanolamine citrate and triethanolamine lactate, were immobilized on activated carbon (SILs) and used to capture SO2 from simulated flue gas. They exhibited excellent adsorption at low SO2 partial pressures due to the presence of a large gas-liquid interface. The molar adsorption ratios reached 7.65 and 2.40 mol/mol at 10 kPa SO2. The SILs possessed good SO2 selectivity in SO2/CO2 and SO2/O2 mixtures, because of the only 8% reduction in the total adsorption of SILs at 60 °C. And they exhibited excellent reversibility in which their total adsorption capacities were unaffected after 5 adsorption-desorption cycles. The mechanism analysis revealed that chemical adsorption was the major adsorption route, although physical adsorption also occurred. The main reactive sites included C-O and N-H groups in the ionic liquid. These SILs may potentially replace traditional chemical absorption materials for the separation of SO2 from flue gas.


Assuntos
Poluentes Atmosféricos , Compostos de Amônio , Líquidos Iônicos , Poluentes Atmosféricos/análise , Compostos de Amônio/análise , Carvão Vegetal , Radical Hidroxila/análise , Líquidos Iônicos/química , Dióxido de Enxofre/análise
11.
J Clin Lab Anal ; 36(12): e24792, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36447406

RESUMO

BACKGROUND: We described a patient who exhibited a gradual increase in carbohydrate antigen 19-9 (CA19-9) concentrations for 4 years at three hospitals, with no associated clinical manifestations; however, we were unable to define the cause of this increase, forcing us to consider whether it was a false-positive result. METHODS: Given the potential for interference, this study used multiple system detection, gradient dilution, Polyethylene glycol (PEG) precipitation and heterophilic antibody blocking assay to evaluate the reliability of CA19-9 concentration increase. RESULTS: Analysis of the patient sample using multiple systems indicated that CA19-9 concentrations showed an obvious increase (154.0, and 889.2 IU/ml, respectively) using the Cobas E602 and Advia Centaur XP systems, and were within the reference ranges (<10 IU/ml) on other modules. PEG precipitation on the Cobas E602 and Advia Centaur XP systems reduced the CA19-9 concentration, as did heterophilic blocking tube (HBT-6, HBT-1) blockade. CONCLUSION: CA19-9 was incorrectly identified to increase due to the presence of heterophilic antibodies. We recommend that heterophilic antibodies should be evaluated in cases with elevated CA19-9 level but no associated clinical manifestations to prevent false positives.


Assuntos
Anticorpos Heterófilos , Antígeno CA-19-9 , Humanos , Reprodutibilidade dos Testes , Seguimentos , Carboidratos
12.
Zhonghua Nan Ke Xue ; 28(7): 603-607, 2022 Jul.
Artigo em Zh | MEDLINE | ID: mdl-37556217

RESUMO

OBJECTIVE: To investigate the correlation of the anterior lobe thickness of the prostate (ALTP) with bladder outlet obstruction (BOO), and evaluate the effect of ALTP on the clinical progression of BPH. METHODS: This retrospective study included 159 cases of BPH. We obtained the clinical indicators of the patients, including ALTP, prostate volume (PV), postvoid residual urine (PVR), maximum urinary flow rate (Qmax), BOO index (BOOI) and IPSS, and analyzed the correlations of ALTP with IPSS, PV, Qmax, age, PVR and BOOI. Using the ROC curve and cut-off point of ALTP, we compared the clinical indicators between the small and large ALTP groups, and analyzed the correlation between ALTP and the clinical progression of BPH. RESULTS: IPSS was not significantly correlated with ALTP (P > 0.05), nor was ALTP with PV and Qmax (P > 0.05). The area under the ROC curve was 0.742 (95% CI: 0.656-0.828) and the cut-off point of ALTP was 0.65 cm. Statistically significant differences were observed in PV, Qmax, IPSS and the rate of surgery between the small ALTP (<0.65 cm) and large ALTP (≥0.65 cm) groups (P < 0.05). CONCLUSION: ALTP is not proportional to PV or to IPSS. ALTP ≥ 0.65 cm increases the incidence of BOO, and may be a risk factor for the clinical progression of BPH.


Assuntos
Hiperplasia Prostática , Obstrução do Colo da Bexiga Urinária , Retenção Urinária , Masculino , Humanos , Hiperplasia Prostática/complicações , Próstata , Estudos Retrospectivos , Obstrução do Colo da Bexiga Urinária/etiologia , Progressão da Doença
13.
Angew Chem Int Ed Engl ; 61(8): e202114182, 2022 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-34874599

RESUMO

Herein, we report the first synthesis of colloidal C4 N quantum dots (QDs) and their functional composites and explore their optical activities and edge-selective polysulfide adsorption-catalysis. As-obtained C4 NQDs are rich in carbonyl groups and edges, allowing good solution processability and facile assembly with other moieties for creating functionalities. While C4 NQDs show normal fluorescence (FL), the QD/poly(vinyl alcohol) (PVA) composites give FL/room-temperature-phosphorescence (RTP) dual-mode emission, enabling the corresponding solution to be used as an encryption ink. The QDs anchored onto carbon nanotubes can be used as a barrier layer to decorate commercial separators, endowing a Li-S cell with excellent cycling stability, high rate capability, and large areal capacity. Computation and experiment studies show that edge sites in C4 N favor polysulfide adsorption and catalysis and the enriched edges and carbonyl groups in QDs synergically promotecatalytic conversion of sulfur species.

14.
Small ; 17(36): e2100955, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34319656

RESUMO

Herein, alkoxylation chemistry is introduced as a "one-stone-three-birds" solution for exploring a new family of highly-fluorescent octupolar 2D-conjugated organic polymers/frameworks (OCOPs/OCOFs) combining far-red emission, high fluorescence quantum yield (QY), and strong two-photon absorption (TPA). Both alkoxy-substituted OCOP and OCOF comprising acrylonitrile-bridged strongly-coupled donor3-(acceptor core) chromophores densely packed in either disordered or ordered forms, exhibit significantly redshifted emission. They produce high QY of 22.2% and 27.8% in tetrahydrofuran, large TPA cross section of 600 and 1124 GM, and 2-3 folds and 15-30 folds that of non-alkoxylate amorphous counterpart respectively. Combined theoretical and experimental studies reveal unique "one-stone-three-birds" role of the alkoxylation in realizing red-shifted-emission, improved QY and TPA enabled by inducing steric hindrance effect for weakened π-π stacking, and triggering p-π conjugation effect for electronically engineering octupolar chromophores, while the crystalline engineering enables enforced coplanarity conformation and improved π-electron delocalization for further improved QY and TPA. The robust and biocompatible pentoxy-substituted polymer can be used not only as metal-free red-emissive phosphor for efficient warm white light-emitting diodes, but also as efficient two-photon fluorescence probes for bio-imaging.


Assuntos
Acrilonitrila , Polímeros , Elétrons , Fótons , Espectrometria de Fluorescência
15.
BMC Musculoskelet Disord ; 22(1): 497, 2021 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-34051759

RESUMO

Lag screw cut-out is the most common cause of fixation failure of trochanteric fractures. Intraoperative assessment of fracture reduction and fixation quality is vital to avoid fracture reduction and achieve good functional outcomes. In a recent study, Zhang et al. reported the occurrence of a reverse wedge effect after intraoperative nail insertion based on a new computed tomography(CT)-guided fracture classification system, which specifically happened to the basicervical facture type and resulted in valgus deformity with gapping at the medial inferior fracture line. Impingement between the reamer/nail and superolateral cortex of the femoral neck has been regarded as the main cause. Based on these findings, together with an extensive literature review, the practicality of the new fracture classification system, the definition of basicervical trochanteric fracture, and the mechanisms underlying the reverse wedge effect have been deeply discussed. More studies should be carried out in the future to analyse pre- and intraoperative related factors that could affect the intraoperative fragment migration effects and determine highly specific measures to address them.


Assuntos
Fixação Intramedular de Fraturas , Fraturas do Quadril , Parafusos Ósseos , Fixação de Fratura , Fixação Intramedular de Fraturas/efeitos adversos , Fraturas do Quadril/diagnóstico por imagem , Fraturas do Quadril/cirurgia , Humanos
16.
Opt Express ; 28(11): 16795-16804, 2020 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-32549494

RESUMO

Nominal dopant-free zinc blende twinning superlattice InP nanowires have been grown with high crystal-quality and taper-free morphology. Here, we demonstrate its superior optical performance and clarify the different carrier recombination mechanisms at different temperatures using a time resolved photoluminescence study. The existence of regular twin planes and lateral overgrowth do not significantly increase the defect density. At room temperature, the as-grown InP nanowires have a strong emission at 1.348 eV and long minority carrier lifetime (∼3 ns). The carrier recombination dynamics is mainly dominated by nonradiative recombination due to surface trapping states; a wet chemical etch to reduce the surface trapping density thus boosts the emission intensity and increases the carrier lifetime to 7.1 ns. This nonradiative recombination mechanism dominates for temperatures above 155 K, and the carrier lifetime decreases with increasing temperature. However, radiative recombination dominates the carrier dynamics at temperature below ∼75 K, and a strong donor-bound exciton emission with a narrow emission linewidth of 4.5 meV is observed. Consequently, carrier lifetime increases with temperature. By revealing carrier recombination mechanisms over the temperature range 10-300 K, we demonstrate the attraction of using InP nanostructure for photonics and optoelectronic applications.

17.
Chirality ; 31(7): 513-521, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31136021

RESUMO

Most amino acids contain chiral centres and exist as both D-enantiomer and L-enantiomer. The optically pure enantiomer is often more valuable than the racemate. Enzymatic resolution provides an effective strategy to obtain optically pure amino acids but often results in large amounts of unwanted isomer. In this study, optically pure L-glufosinate (L-PPT) was obtained by coupling amidase-mediated hydrolysis of N-phenylacetyl-D,L-glufosinate with racemization of N-phenylacetyl-D-glufosinate (NPDG), which exclusively exhibits effective herbicidal properties compared with its D-enantiomer. To improve the yield of L-PPT, the racemization reaction conditions were optimized, and through single-factor experiments, the optimal reaction temperature, reaction time, and mole ratio of phenylacetic acid to NPDG were determined to be 150°C, 30 minutes, and 1.5, respectively. The response surface methodology was applied to further optimize the racemization conditions, and the final yield of L-PPT reached 96.13% with optimum reaction temperature of 154°C, reaction time of 23 minutes, and phenylacetic acid/NPDG mole ratio of 1.7, respectively. Moreover, adding a small amount of acetic anhydride further raised the yield of L-PPT to 97.02%.

18.
Angew Chem Int Ed Engl ; 58(45): 16217-16222, 2019 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-31424611

RESUMO

A combined surface and dual electronic modulation strategy is used to realize metal-free all-pH catalysis towards the hydrogen evolution reaction (HER) by coupling a N-doped carbon framework (MHCF, electron acceptors) derived from MOFs with higher-Fermi-level pure carbon nanotubes (CNTs, electron donors), followed by surface modification with carboxyl-group-rich polymers. Although the three constituents are inactive, as-assembled ternary membranes yield superior HER performance with low overpotentials and high durability (≤5 % activity loss over 100 h) at all pH values. The C adjacent to pyrrolic N in MHCF is the most active site and the induced directional interfacial electron transfer from CNTs to MHCF coupled with N-driven intramolecular electron transfer in MHCF optimizes Gibbs free energy for hydrogen adsorption (ΔGH* ) near zero, while the polymer modulation enables local H+ enrichment in acidic media and enhanced water adsorption and activation in neutral and basic media.

19.
J Cell Mol Med ; 22(11): 5208-5219, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30589494

RESUMO

Acute myocardial infarction (MI) is a leading cause of morbidity and mortality in the world. Traditional method to induce MI by left coronary artery (LCA) ligation is typically performed by an invasive approach that requires ventilation and thoracotomy, causing serious injuries in animals undergoing this surgery. We attempted to develop a minimally invasive method (MIM) to induce MI in mice. Under the guide of ultrasound, LCA ligation was performed in mice without ventilation and chest-opening. Compared to sham mice, MIM induced MI in mice as determined by triphenyltetrazolium chloride staining and Masson staining. Mice with MIM surgery revealed the reductions of LVEF, LVFS, E/A and ascending aorta (AAO) blood flow, and the elevations of S-T segment and serum cTn-I levels at 24 post-operative hours. The effects of MI induced by MIM were comparable to the effects of MI produced by traditional method in mice. Importantly, MIM increased the survival rates and caused less inflammation after the surgery of LCA ligation, compared to the surgery of traditional method. Further, MIM induced angiogenesis and apoptosis in ischaemic hearts from mice at postoperative 28 days as similarly as traditional method did. Finally, the MIM model was able to develop into the myocardial ischaemia/reperfusion model by using a balloon catheter with minor modifications. The MI model is able to be efficiently induced by a minimally invasive approach in mice without ventilation and chest-opening. This new model is potentially to be used in studying ischaemia-related heart diseases.


Assuntos
Vasos Coronários/cirurgia , Procedimentos Cirúrgicos Minimamente Invasivos/métodos , Infarto do Miocárdio/cirurgia , Isquemia Miocárdica/cirurgia , Animais , Vasos Coronários/fisiopatologia , Modelos Animais de Doenças , Humanos , Ligadura/métodos , Camundongos , Infarto do Miocárdio/fisiopatologia , Isquemia Miocárdica/fisiopatologia , Miocárdio/patologia , Toracotomia/métodos
20.
Biochem Biophys Res Commun ; 486(3): 607-612, 2017 05 06.
Artigo em Inglês | MEDLINE | ID: mdl-28341124

RESUMO

Tenascin-C (TNC), as a member of the extracellular matrix (ECM), plays an important role in cancer cell proliferation and migration and tumor invasion in various types of cancer. Here, we attempted to investigate the role of TNC as a prognostic factor in prostate cancer. We studied TNC expression via immunohistochemistry in 145 prostate cancer tissue samples. The clinicopathological relevance of TNC expression was examined, as well as other cancer-associated fibroblasts (CAFs)-related factors. Our results showed that the high levels of TNC expression in prostate cancer stroma was significantly associated with lymph node metastasis (P = 0.024) and clinical stage (P = 0.032). Furthermore, TNC was positively correlated with increased micro-vessel density (MVD) (P = 0.017) and tumor associated macrophage (TAM) population (P = 0.025). In both univariate and multivariate Cox regression analyses, TNC (P < 0.001) was an independent poor prognostic factor for overall survival in prostate cancer patients. Moreover, over-expression of TNC (P < 0.001), SMA (P = 0.042) and vimentin (P = 0.010) were significantly correlated with the lower overall survival. In addition, TNC expression in prostate cancer stroma was significantly associated with FSP1 (P = 0.011), SMA (P = 0.021), and vimentin (P = 0.002). In conclusion, our study revealed that high level of TNC as a potential biomarker of CAFs was significantly correlated with the poor prognosis for prostate cancer patients.


Assuntos
Actinas/genética , Biomarcadores Tumorais/genética , Carcinoma/diagnóstico , Neoplasias da Próstata/diagnóstico , Tenascina/genética , Vimentina/genética , Actinas/metabolismo , Idoso , Biomarcadores Tumorais/metabolismo , Proteínas de Ligação ao Cálcio/genética , Proteínas de Ligação ao Cálcio/metabolismo , Fibroblastos Associados a Câncer/metabolismo , Fibroblastos Associados a Câncer/patologia , Carcinoma/genética , Carcinoma/mortalidade , Carcinoma/patologia , Regulação Neoplásica da Expressão Gênica , Humanos , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Estadiamento de Neoplasias , Prognóstico , Neoplasias da Próstata/genética , Neoplasias da Próstata/mortalidade , Neoplasias da Próstata/patologia , Proteína A4 de Ligação a Cálcio da Família S100 , Transdução de Sinais , Análise de Sobrevida , Tenascina/metabolismo , Vimentina/metabolismo
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