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1.
Int J Biol Macromol ; 268(Pt 2): 131946, 2024 Apr 29.
Artículo en Inglés | MEDLINE | ID: mdl-38692545

RESUMEN

The development of flexible wearable multifunctional electronics has gained great attention in the field of human motion monitoring. However, developing mechanically tough, highly stretchable, and recyclable composite conductive materials for application in multifunctional sensors remained great challenges. In this work, a mechanically tough, highly stretchable, and recyclable composite conductive elastomer with the dynamic physical-chemical dual-crosslinking network was fabricated by the combination of multiple hydrogen bonds and dynamic ester bonds. To prepare the proposed composite elastomers, the polyaniline-modified carboxylate cellulose nanocrystals (C-CNC@PANI) were used as both conductive filler to yield high conductivity of 15.08 mS/m, and mechanical reinforcement to construct the dynamic dual-crosslinking network with epoxidized natural rubber latex to realize the high mechanical strength (8.65 MPa) and toughness (29.57 MJ/m3). Meanwhile, the construction of dynamic dual-crosslinking network endowed the elastomer with satisfactory recyclability. Based on these features, the composite conductive elastomers were used as strain sensors, and electrode material for assembling flexible and recyclable self-powered sensors for monitoring human motions. Importantly, the composite conductive elastomers maintained reliable sensing and energy harvesting performance even after multiple recycling process. This study provides a new strategy for the preparation of recyclable, mechanically tough composite conductive materials for wearable sensors.

2.
Front Oncol ; 14: 1374674, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38590648

RESUMEN

Backgrounds: The value of circulating microRNA (miR)-155 for breast cancer (BC) diagnosis may differ in different studies. Therefore, we conducted this systematic review and meta-analysis to evaluate the potential application of circulating miR-155 in the diagnosis of BC. Methods: Articles published before December 2023 and in English were searched in these databases: PubMed, Web of Science, Medline, EMBASE and Google Scholar. A summary of sensitivity, specificity, positive likelihood ratios (PLR), negative likelihood ratios (NLR), and diagnostic odds ratio (DOR) were calculated from the true positive (TP), true negative (TN), false positive (FP) and false negative (FN) of each study. Additionally, the summary receive-operating characteristics (SROC) curve was constructed to summarize the TP and FP rates. Results: The pooled parameters calculated were as follows: sensitivity, 0.93 (95% CI: 0.83-0.97); specificity, 0.85 (95% CI: 0.74-0.92); PLR, 6.4 (95% CI: 3.4-11.9); NLR, 0.09 (95% CI: 0.04-0.20); and DOR, 74 (95% CI: 22-247). The analysis showed a significant heterogeneity (sensitivity, I2 = 95.19%, p < 0.001; specificity, I2 = 95.29%, p < 0.001; DOR, I2 = 92.9%, p < 0.001). The SROC curve was with an area under curve (AUC) of 0.95 (95% CI: 0.93-0.97). Conclusion: Circulating miR-155 has a potential in the diagnosis of BC.

3.
Water Res ; 256: 121589, 2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38608620

RESUMEN

Fe2+ is usually adsorbed to the surface of iron-bearing clay, and iron (hydr)oxide in groundwater. However, the reductive activity of Fe(OH)2, a prevalent intermediate during the transformation of Fe2+, remains unclear. In this study, high-purity Fe(OH)2 was synthesized and tested for its activity in the degradation of carbon tetrachloride (CT). XRD data confirm that the synthesized material is a pure Fe(OH)2 crystal, exhibiting sharp peaks of (001) and (100) facets. Zeta potential analysis confirms that the off-white Fe(OH)2 is a colloidal suspension with a positive charge of ∼+35-50 mV. FTIR spectra reveal the formation of a coordination compound Fe2+ with OH-/OD-, derived from NaOH/OD. SEM and HRTEM results demonstrate that the Fe(OH)2 crystal has a regular octahedral structure with a size of ∼30-70 nm and average lattice spacings of 2.58 Å. Mössbauer spectrum verifies that the Fe2+ in Fe(OH)2/Fe(OD)2 is hexacoordinated with six Fe-O bonds. XAFS data demonstrate that the Fe-O bonds become shorter as the OH-:Fe(II) ratios increase. DFT results indicate that the (100) crystal face of Fe(OH)2 more readily transfers electrons to CT. In addition to being adsorbed to iron compounds, structural Fe2+ compounds such as Fe(OH)2 could also accelerate the electron transfer from Fe2+ to CT through shortened Fe-O bonds. The rate constant of CT reduction by Fe(OH)2 is as high as 0.794 min-1 when the OH-:Fe(II) ratio is 2.5 in water. This study aims to enhance our understanding of the structure-reactivity relationship of Fe2+ compounds in groundwater, particularly in relation to electron transfer mechanisms.


Asunto(s)
Coloides , Coloides/química , Hierro/química , Oxidación-Reducción , Compuestos Férricos/química , Halogenación , Agua Subterránea/química
4.
Sensors (Basel) ; 24(5)2024 Feb 25.
Artículo en Inglés | MEDLINE | ID: mdl-38475025

RESUMEN

A simple microwave photonic, reconfigurable, instantaneous frequency measurement system based on low-voltage thin-film lithium niobate on an insulator phase modulator is put forward and experimentally demonstrated. Changing the wavelength of the optical carrier can realize the flexibility of the frequency measurement range and accuracy, showing that during the ranges of 0-10 GHz, 3-15 GHz, and 12-18 GHz, the average measurement errors are 26.9 MHz, 44.57 MHz, and 13.6 MHz, respectively, thanks to the stacked integrated learning models. Moreover, this system is still able to respond to microwave signals of as low as -30 dBm with the frequency measurement error of 62.06 MHz, as that low half-wave voltage for the phase modulator effectively improves the sensitivity of the system. The general-purpose, miniaturized, reconfigurable, instantaneous frequency measurement modules have unlimited potential in areas such as radar detection and early warning reception.

5.
Water Res ; 254: 121342, 2024 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-38428238

RESUMEN

The coordination environment of Fe(II) significantly affect the reductive reactivity of Fe(II). Lactate is a common substrate for enhancing microbial dechlorination, but its effect on abiotic Fe(II)-driven reductive dechlorination is largely ignored. In this study, the structure-reactivity relationship of Fe(II) is investigated by regulating the ratio of lactate:Fe(II). This work shows that lactate-Fe(II) complexing enhances the abiotic Fe(II)-driven reductive dechlorination with the optimum lactate:Fe(II) ratio of 10:20. The formed hydrogen bond (Fe-OH∙∙∙∙∙∙O = C-) and Fe-O-C metal-ligand bond result in a reduced Fe(II) coordination number from six to four, which lead to the transition of Fe(II) coordination geometry from octahedron to tetrahedron/square planar. Coordinatively unsaturated Fe(II) results in the highest reductive dechlorination reactivity towards carbon tetrachloride (k1 = 0.26254 min-1). Excessive lactate concentration (> 10 mM) leads to an increased Fe(II) coordination number from four to six with a decreased reductive reactivity. Electrochemical characterization and XPS results show that lactate-Fe(II)-I (C3H5O3-:Fe(II) = 10:20) has the highest electron-donating capacity. This study reveals the abiotic effect of lactate on reductive dechlorination in a subsurface-reducing environment where Fe(II) is usually abundant.


Asunto(s)
Ácido Láctico , Metales , Tetracloruro de Carbono/química , Compuestos Ferrosos
6.
Amino Acids ; 56(1): 17, 2024 Feb 23.
Artículo en Inglés | MEDLINE | ID: mdl-38393495

RESUMEN

The development of the goat mammary gland is mainly under the control of ovarian hormones particularly estrogen and progesterone (P4). Amino acids play an essential role in mammary gland development and milk production, and sodium-coupled neutral amino acid transporter 2 (SNAT2) was reported to be expressed in the mammary gland of rats and bovine mammary epithelial cells, which may affect the synthesis of milk proteins or mammary cell proliferation by mediating prolactin, 17ß-estradiol (E2) or methionine function. However, whether SNAT2 mediates the regulatory effects of E2 and P4 on the development of the ruminant mammary gland is still unclear. In this study, we show that E2 and P4 could increase the proliferation of goat mammary epithelial cells (GMECs) and regulate SNAT2 mRNA and protein expression in a dose-dependent manner. Further investigation revealed that SNAT2 is abundantly expressed in the mammary gland during late pregnancy and early lactation, while knockdown and overexpression of SNAT2 in GMECs could inhibit or enhance E2- and P4-induced cell proliferation as well as mammalian target of rapamycin (mTOR) signaling. We also found that the accelerated proliferation induced by SNAT2 overexpression in GMECs was suppressed by the mTOR signaling pathway inhibitor rapamycin. This indicates that the regulation of GMECs proliferation mediated by SNAT2 in response to E2 and P4 is dependent on the mTOR signaling pathway. Finally, we found that the total content of the amino acids in GMECs changed after knocking-down and overexpressing SNAT2. In summary, the results demonstrate that the regulatory effects of E2 and P4 on GMECs proliferation may be mediated by the SNAT2-transported amino acid pathway. These results may offer a novel nutritional target for improving the development of the ruminant mammary gland and milk production.


Asunto(s)
Estrógenos , Cabras , Progesterona , Animales , Femenino , Embarazo , Aminoácidos/metabolismo , Proliferación Celular , Células Epiteliales/metabolismo , Estrógenos/metabolismo , Cabras/genética , Cabras/metabolismo , Glándulas Mamarias Animales/metabolismo , Progesterona/metabolismo , Serina-Treonina Quinasas TOR/genética , Serina-Treonina Quinasas TOR/metabolismo
7.
Water Res ; 245: 120636, 2023 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-37748348

RESUMEN

Labile Fe(III) phase (includes Fe(III)aq, Fe(III)ads, or Fe(III)s species) is an important intermediate during the interaction between Fe(II) and Fe(III) (oxyhydr)oxides, but how does labile Fe(III) influence the electron transfer from Fe(II) to oxidant environmental pollutant during this Fe(II)-Fe(III) interaction is unclear. In this work, the dynamic change of Fe(II,III) (oxyhydr)oxides at the same time scale is simulated by synthesizing Fe(III)-Fe(II)-I (Fe(III)+NaOH+Fe(II)+NaOH) with different Fe(II)/Fe(III) ratios. CCl4 is used as a convenient probe to test the reduction kinetics of mixed valence Fe(II,III)(oxyhydr)oxides with different Fe(II):Fe(III) ratios. The Mössbauer spectra results reveal the Fe(III)labile in the solid phase is in octahedral coordination. The electron-donating capability of Fe(II) was improved with increasing Fe(III) content, but suppressed when [Fe(III)] ≥ 30 mM. The reductive dechlorination of CT by Fe(III)-Fe(II)-I decreased gradually with the increase of Fe(III) content, because more amount Fe(III)labile in solid phase is accumulated. This shows that the electron transfer from Fe(II) to Fe(III)labile rather than to CT is enhanced with increasing Fe(III) content. FTIR data shows that the hydroxylation of Fe(II) with Fe(OH)3 occurs preferentially in the non-hydrogen bonded hydroxyl group, causing the decrease of its reductive reactivity. The presence of [Fe(III)-O-Fe(II)]+ in Fe(III)-Fe(II)-I can stabilize the dichlorocarbene anion (:CCl2-), favouring the conversion of CT to CH4 (13.1%). The aging experiment shows that Fe(III)labile surface may maintain the reductive reactivity of Fe(II) during aging when [Fe(III)] = 5-20 mM. This study deepens our understanding of the mass transfer pathway of iron oxyhydroxides induced by Fe(II) and its impact on the reductive dechlorination of CT.

8.
Stress ; 26(1): 2252938, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37632459

RESUMEN

As endocrine hormones, glucocorticoids (GCs) play a pivotal role in numerous physiological processes, including mammary growth and lactation, circulatory metabolism, and responses to external stimuli. In the dairy industry, milk production from cows or goats is important for newborns and economic benefits. However, the milk yields from ruminant animals are always affected by the extent of mammary development, mammary disease, stress, or changes in metabolism. Thus, it is necessary to clarify how GCs changes in ruminants affect ruminant mammary gland function and mammary disease. This review summarizes the findings identifying that GCs modulate mammary gland development before lactation, but the stress-induced excessive release of GCs leads to milk production loss. In addition, the manner of GCs release may change under different concentrations of metabolites or during mastitis or inflammatory challenge. Nevertheless, exogenous GCs administration to animals may alleviate the clinical symptoms of mastitis. This review demonstrates that GCs offer a fascinating contribution to both physiologic and pathogenic conditions of the mammary gland in ruminant animals. Characterizing and understanding these changes or functions of endogenous and exogenous GCs in animals will be crucial for developing more endocrine regulators and therapies for improving milk production in ruminants.


Asunto(s)
Glucocorticoides , Mastitis , Femenino , Humanos , Bovinos , Animales , Leche , Estrés Psicológico , Rumiantes
9.
J Hazard Mater ; 458: 131872, 2023 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-37379598

RESUMEN

Humic acid (HA) and ferrous minerals (e.g. green rust, GR) are abundant in groundwater. HA acts as a geobattery that take up and release electrons in redox-alternating groundwater environments. However, the impact of this process on the fate and transformation of groundwater pollutants is not fully understood. In this work, we found that the adsorption of HA on GR inhibited the adsorption of tribromophenol (TBP) under anoxic conditions. Meanwhile, GR could donate electrons to HA, causing the electron donating capacity of HA rapidly increase from 12.7% to 27.4% in 5 min. The electron transfer process from GR to HA significantly increased the yield of hydroxyl radicals (•OH) and the degradation efficiency of TBP during GR-involved dioxygen activation process. Compared to the limited electronic selectivity (ES) of GR for •OH production (ES = 0.83%), GR-reduced HA improves the ES by an order of magnitude (ES = 8.4%). HA-involved dioxygen activation process expands the •OH generation interface from solid phase to aqueous phase, which is conducive to the degradation of TBP. This study not only deepens our understanding on the role of HA in •OH production during GR oxygenation, but also provides a promising approach for groundwater remediation under redox-fluctuating conditions.

10.
Opt Lett ; 48(9): 2465-2467, 2023 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-37126299

RESUMEN

Difficulty in etching lithium niobate (LN) results in a relatively high propagation loss, which necessitates sophisticated processes to fabricate high-quality factor (Q) microresonators. Here, we fabricate a multimode microring resonator with an intrinsic Q of 6 × 106, which exhibits a propagation loss 50 times lower than that of a single-mode LN microring fabricated under the same process. Notably, the excitation of higher-order modes in the multimode microring is effectively suppressed by utilizing the Euler bend. The highly regular transmission spectrum of the resonator demonstrates a free spectral range (FSR) of 56 GHz. Based on this microresonator, we implement a bandpass microwave photonic filter with an ultra-narrow 3 dB bandwidth of 47.5 MHz and a large tuning range of 2-26.5 GHz. It can be anticipated that the combination of existing advanced etching techniques with this work will drive the propagation loss of a LN waveguide closer to the material absorption loss, significantly facilitating the optimization of performance in applications requiring ultrahigh-Q LN microresonators, such as frequency combs, frequency conversion, electro-optic modulation, and quantum photonics.

11.
Biochem Pharmacol ; 213: 115617, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-37211174

RESUMEN

Fusion with host cell membrane is the main mechanism of infection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Here, we propose that a new strategy to screen small-molecule antagonists blocking SARS-CoV-2 membrane fusion. Using cell membrane chromatography (CMC), we found that harringtonine (HT) simultaneously targeted SARS-CoV-2 S protein and host cell surface TMPRSS2 expressed by the host cell, and subsequently confirmed that HT can inhibit membrane fusion. HT effectively blocked SARS-CoV-2 original strain entry with the IC50 of 0.217 µM, while the IC50 in delta variant decreased to 0.101 µM, the IC50 in Omicron BA.1 variant was 0.042 µM. Due to high transmissibility and immune escape, Omicron subvariant BA.5 has become the dominant strain of the SARS-CoV-2 virus and led to escalating COVID-19 cases, however, against BA.5, HT showed a surprising effectiveness. The IC50 in Omicron BA.5 was even lower than 0.0019 µM. The above results revealed the effect of HT on Omicron is very significant. In summary, we characterize HT as a small-molecule antagonist by direct targeting on the Spike protein and TMPRSS2.


Asunto(s)
COVID-19 , Harringtoninas , Humanos , SARS-CoV-2
12.
Sensors (Basel) ; 23(8)2023 Apr 07.
Artículo en Inglés | MEDLINE | ID: mdl-37112146

RESUMEN

This work presents a silicon-based capacitively transduced width extensional mode (WEM) MEMS rectangular plate resonator with quality factor (Q) of over 10,000 at a frequency of greater than 1 GHz. The Q value, determined by various loss mechanisms, was analyzed and quantified via numerical calculation and simulation. The energy loss of high order WEMs is dominated by anchor loss and phonon-phonon interaction dissipation (PPID). High-order resonators possess high effective stiffness, resulting in large motional impedance. To suppress anchor loss and reduce motional impedance, a novel combined tether was designed and comprehensively optimized. The resonators were batch fabricated based on a reliable and simple silicon-on-insulator (SOI)-based fabrication process. The combined tether experimentally contributes to low anchor loss and motional impedance. Especially in the 4th WEM, the resonator with a resonance frequency of 1.1 GHz and a Q of 10,920 was demonstrated, corresponding to the promising f × Q product of 1.2 × 1013. By using combined tether, the motional impedance decreases by 33% and 20% in 3rd and 4th modes, respectively. The WEM resonator proposed in this work has potential application for high-frequency wireless communication systems.

13.
Medicine (Baltimore) ; 102(14): e33297, 2023 Apr 07.
Artículo en Inglés | MEDLINE | ID: mdl-37026911

RESUMEN

The effect of various metastases patterns on the prognosis of lung adenocarcinoma (AD) remains unknown. The purpose of our retrospective study is to determine whether various metastases patterns have a prognostic impact on patients with organ metastatic lung AD. Patient data was extracted from the Surveillance, Epidemiology, and End Results (SEER) database. The Kaplan-Meier method was chosen for the evaluation of overall survival (OS) rate. Univariable and multivariable Cox regression analyses were conducted to evaluate independent prognostic factors. In the SEER database, 12,228 patients with IV lung AD were retrieved in total. And 78.78% of those patients (9633/12,228) suffered from one of brain, lung, liver or bone metastasis due to disease progression. It was found that the most common site in patients with metastatic lung AD was brain (21.20%), and the least common site of metastasis was liver (3.50%). Patients who suffered single lung metastatic showed relatively good OS, and the median survival time was 11 months (95% CI 0.470-0.516). For those with 2 metastatic sites, data analysis suggested that the median survival times of patients with bone and lung metastasis (10 months; 95% CI 0.469-0.542) were better than others. For those with 3 metastatic sites, data analysis suggested that metastatic pattern had no effect on the OS. Brain is the most common single metastasis site of lung AD. Compared with the other 3 metastatic sites, patients with lung metastasis had better survival results. Deeper knowledge of metastatic patterns will help doctors to better understand the prognosis and formulate more appropriate treatment plans.


Asunto(s)
Adenocarcinoma del Pulmón , Neoplasias Hepáticas , Neoplasias Pulmonares , Humanos , Pronóstico , Estudios Retrospectivos , Neoplasias Hepáticas/patología , Programa de VERF , Estimación de Kaplan-Meier , Neoplasias Pulmonares/patología
14.
J Chromatogr A ; 1693: 463903, 2023 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-36870232

RESUMEN

Patients have different responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections and these may be life-threatening for critically ill patients. Screening components that act on host cell receptors, especially multi-receptor components, is challenging. The in-line combination of dual-targeted cell membrane chromatography and a liquid chromatography-mass spectroscopy (LC-MS) system for analyzing angiotensin-converting enzyme 2 (ACE2) and cluster of differentiation 147 (CD147) receptors based on SNAP-tag technology provides a comprehensive solution for screening multiple components in complex samples acting on the two receptors. The selectivity and applicability of the system were validated with encouraging results. Under the optimized conditions, this method was used to screen for antiviral components in Citrus aurantium extracts. The results showed that 25 µmol /L of the active ingredient could inhibit virus entry into cells. Hesperidin, neohesperidin, nobiletin, and tangeretin were identified as antiviral components. In vitro pseudovirus assays and macromolecular cell membrane chromatography further verified the interaction of these four components with host-virus receptors, showing good effects on some or all of the pseudoviruses and host receptors. In conclusion, the in-line dual-targeted cell membrane chromatography LC-MS system developed in this study can be used for the comprehensive screening of antiviral components in complex samples. It also provides new insight into small-molecule drug-receptor and macromolecular-protein-receptor interactions.


Asunto(s)
COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/metabolismo , Enzima Convertidora de Angiotensina 2 , Peptidil-Dipeptidasa A/química , Peptidil-Dipeptidasa A/metabolismo , Membrana Celular/metabolismo , Antivirales/farmacología
15.
Anal Bioanal Chem ; 415(7): 1371-1383, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36651973

RESUMEN

In this study, a novel cell membrane chromatography (CMC) model was developed to investigate cluster of differentiation 147 (CD147) targeted anti-tumor drug leads for specific screening and ligand-receptor interaction analysis by SNAP-tagged CD147 fusion protein conjugation and polystyrene microspheres (PS) modification. Traditional Chinese medicines (TCMs) are widely used in the treatment of cancer. CD147 plays important roles in tumor progression and acts as an attractive target for therapeutic intervention; therapeutic drugs for CD147-related cancers are limited to date. Thus, a screening method for active components in TCMs is crucial for the further research and development of CD147 antagonists. However, improvement is still needed to perform specific and accurate drug lead screening using the CMC-based method. Recently, our group developed a covalently immobilized receptor-SNAP-tag/CMC model using silica gel as carrier. Besides the carboxyl group on multi-step modified silica particles, the amino group of benzyl-guanine (BG, substrate of SNAP-tag) also possesses reactivity towards the carboxyl group on available carboxyl-modified PS. Herein, we used PS as carrier and an extended SNAP-tag with CD147 receptor to construct the PS-BG-CD147/CMC model for active compound investigation coupled with HPLC/MS and applied this coupled PS-BG-CD147/CMC-HPLC/MS two-dimensional system to drug lead screening from Nelumbinis Plumula extract (NPE) sample. In addition, to comprehensively verify the pharmacological effects of screened ingredients, a cell proliferation inhibition assay was performed, and the interaction between the ingredients and CD147 was studied by the frontal analysis method. This study developed a high-throughput PS-based CMC screening platform, which could be widely applied and utilized in chromatographic separation and drug lead discovery.


Asunto(s)
Medicamentos Herbarios Chinos , Medicamentos Herbarios Chinos/química , Poliestirenos/análisis , Microesferas , Cromatografía Líquida de Alta Presión/métodos , Membrana Celular/química
16.
Water Res ; 228(Pt A): 119386, 2023 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-36427462

RESUMEN

Fe(II) and silicate can form Si-Fe(II) co-precipitates in anoxic groundwater and sediments, but their phase composition and reactivity towards subsurface pollutants are largely unknown. Three types of Si-Fe(II) co-precipitations with the same chemical composition, namely Si-Fe(II)-I, Si-Fe(II)-II, and Si-Fe(II)-III, have been synthesized by different hydroxylation sequences in this work. It was found that Si-Fe(II)-III reduce carbon tetrachloride (CT) much faster (k1=0.04419 min-1) than Si-Fe(II)-I (0 min-1) and Si-Fe(II)-II (7.860 × 10-4 min-1). XRD results show that the main component of Si-Fe(II)-III is ferrous silicate (FeSiO3), which is quite different from that of Si-Fe(II)-I and Si-Fe(II)-II. The unique arrangement of hydroxyl coordination, the less distorted octahedral structure, the polyhedral morphology and the absence of Si-A center vacancies in Si-Fe(II)-III are responsible for its high reductive dehalogenation reactivity. The highest redox activity of Si-Fe(II)-III was shown by electrochemical characterization. The [FeII-O-Si]+ in Si-Fe(II)-III may stabilize the dichlorocarbene anion (˸CCl2-), which favors the transformation of CT to methane (9.2%). The Si-Fe(II) co-precipitates consist of countless internal electric fields, and the transformation of hydroxyl and CT both consumed electrons. The coexistence of hydroxyl and CT increases the electron density in the electron-rich region due to their electronegativity, enhancing their electron-accepting capabilities. This study deepens our understanding of the phase composition and electronic structure of Si-Fe(II) co-precipitates, which fills the gap in the reductive dehalogenation of halides by Si-Fe(II) co-precipitates.


Asunto(s)
Electricidad , Agua Subterránea , Tetracloruro de Carbono , Electrones , Radical Hidroxilo , Compuestos Ferrosos
17.
Small ; 19(4): e2205735, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36437051

RESUMEN

The construction of hollow metallic microspheres with rationally designed building blocks of the metal shell is a promising way to achieve low density and functionality control, but the microengineering of the metallic structures on a micrometer spherical surface is a great challenge. In the present work, a novel and simple calcination-induced aggregation strategy is developed to realize the distribution status and microstructure control of Co-Cu bimetal building blocks assembled on a hollow glass microsphere support, and thus a series of low-density (0.58 g cm-3 ) dual shell composite hollow microspheres are constructed with gradient in electromagnetic property depending on the calcination temperature (CT). The optimized microwave shielding performance can be achieved at a CT of 500 °C, while further increasing CT to 700 °C leads to an interesting conversion from microwave shielding to absorption with an optimized effective absorption bandwidth of 4.64 GHz at a low matching thickness of 1.33 mm. The mechanism underlying the CT-dependent metallic shell structure variation and further the decisive effect of the shell structure on the microwave response behavior are proposed based on a series of contrast experiments.

18.
Polymers (Basel) ; 14(23)2022 Nov 25.
Artículo en Inglés | MEDLINE | ID: mdl-36501524

RESUMEN

Based on the reduction of environmental pollution, a biological enzyme assisted alkali-oxygen pulping method was explored to improve the delignification efficiency and fiber accessibility of wheat straw and improve the properties of wheat straw pulp. In this paper, lipase and xylanase were used to pretreat wheat straw and the effects of different enzyme types and enzyme dosage on the microstructure and pulp properties of wheat straw were investigated and experimented. The results showed that the lipase can remove fat and wax on the surface of wheat straw, while xylanase degraded the hemicellulose components, such as xylan, of wheat straw fiber, destroyed the structure of the lignin-carbohydrate complex, increasing lignin removal as a result and enhancing the impregnating, diffusion and penetration of alkali. Compared with wheat straw without enzyme pretreatment, the skeleton of wheat straw pretreated by enzyme became looser, the internal cavity appeared and the wall cavity became thin and transparent. The fines decreased obviously and the length of fibers increased. After combined pretreatment with lipase (15 U·g-1) and xylanase (15 U·g-1), the pulping performance of wheat straw was improved and the tensile index (97.37 N·m·g-1), brightness (40.9% ISO) and yield (58.10%) of the pulp increased by 12.9%, 19.9% and 9.9%, respectively. It can be seen that enzyme pretreatment is a green and effective approach to improving the alkali-oxygen pulping performance of wheat straw.

19.
Medicine (Baltimore) ; 101(40): e29999, 2022 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-36221346

RESUMEN

BACKGROUND: To compare the effects of thermal softening of double-lumen endotracheal tubes (DLT) at different temperatures during fiberoptic bronchoscopy (FOB)-guided intubation. METHODS: We randomly divided 144 patients undergoing thoracic surgery into 4 groups as follows: T1 (T = 24 ± 1°C, n = 36), T2 (T = 36 ± 1°C, n = 36), T3 (T = 40 ± 1°C, n = 36), and T4 (T = 48 ± 1°C, n = 36). All groups underwent FOB-guided double-lumen endotracheal intubation and positioning. We recorded the duration of positioning and intubation using DLT, intubation resistance (IR), the success rate of the first attempt at endotracheal intubation, and the incidence of postoperative vocal cord injury and hoarseness. RESULTS: The time to intubation was longer in the T1 group than that in the T2, T3, and T4 groups (P < .05). The time for positioning was longer in the T4 group than that in the T1, T2, and T3 groups (P < .05). IR was lower in the T3 and T4 groups than those in T1 and T2 groups (P < .05). The success rate of the first attempt at endotracheal intubation was higher in the T2, T3, and T4 groups than that in the T1 group (P < .05). Postoperative glottic injury and hoarseness were higher in the T1 and T2 groups than those in the T3 and T4 groups (P < .05). CONCLUSION: A thermally softened DLT shortened the time to intubation, reduced the IR, improved the success rate of the first attempt at endotracheal intubation, and lowered the incidence of postoperative glottic injury and hoarseness. The optimal tube temperature for FOB-guided intubation of thermally softened DLT was 40 ± 1°C.


Asunto(s)
Broncoscopía , Intubación Intratraqueal , Broncoscopios , Broncoscopía/efectos adversos , Broncoscopía/instrumentación , Ronquera/epidemiología , Humanos , Intubación Intratraqueal/efectos adversos , Intubación Intratraqueal/métodos , Temperatura
20.
Appl Opt ; 61(23): 6795-6803, 2022 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-36255758

RESUMEN

This work presents a simple microwave photonic downconversion channelizer based on multi-wavelength laser sources. The design of two laser diode (LD) arrays enables signal multiplexing and simultaneous multichannel downconversion processing, which provide stable, relatively flat, and strong multi-frequency combs. A proof-of-concept experiment was taken, showing that 14.375-17.75 GHz broadband radio frequency (RF) signals were successfully downconverted to the same intermediate frequency (IF) and were sliced into four subchannels with 875 MHz bandwidth showing excellent image rejection and channel uniformity, which agrees with the simulation results. The spurious free dynamic range (SFDR) of the proposed RF channelizer is 100dBHz2/3, the image rejection is over 28 dB, and the frequency measurement error is less than ±6MHz. Replacing optical filters with electrical filters, the proposed simple optoelectronic hybrid reconfigurable microwave photonic channelizer system acquits stable performance and high maturity and meets the application requirements, behaving with stupendous potential in fields such as radar, satellite communication, electronic warfare, and others.

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