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1.
Environ Monit Assess ; 196(5): 448, 2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38607467

RESUMO

Soil in mining wastelands is seriously polluted with heavy metals. Zero-valent iron (ZVI) is widely used for remediation of heavy metal-polluted soil because of its excellent adsorption properties; however, the remediation process is affected by complex environmental conditions, such as acid rain and freeze-thaw cycles. In this study, the effects of different pH values and freeze-thaw cycles on remediation of antimony (Sb)- and arsenic (As)-contaminated soil by ZVI were investigated in laboratory simulation experiments. The stability and potential human health risks associated with the remediated soil were evaluated. The results showed that ZVI has a significant stabilizing effect on Sb and As in both acidic and alkaline soils contaminated with dual levels of Sb and As, and the freeze-thaw process in different pH value solution systems further enhances the ability of ZVI to stabilize Sb and As, especially in acidic soils. However, it should be noted that apart from the pH=1.0 solution environment, ZVI's ability to stabilize As is attenuated under other circumstances, potentially leading to leaching of its unstable form and thereby increasing contamination risks. This indicates that the F1 (2% ZVI+pH=1 solution+freeze-thaw cycle) processing exhibits superior effectiveness. After F1 treatment, the bioavailability of Sb and As in both soils also significantly decreased during the gastric and intestinal stages (about 60.00%), the non-carcinogenic and carcinogenic risks of Sb and As in alkaline soils are eliminated for children and adults, with a decrease ranging from 60.00% to 70.00%, while in acidic soil, the non-carcinogenic and carcinogenic risks of As to adults and children is acceptable, but Sb still poses non-carcinogenic risks to children, despite reductions of about 65.00%. These findings demonstrate that soil pH is a crucial factor influencing the efficacy of ZVI in stabilizing Sb and As contaminants during freeze-thaw cycles. This provides a solid theoretical foundation for utilizing ZVI in the remediation of Sb- and As-contaminated soils, emphasizing the significance of considering both pH levels and freeze-thaw conditions to ensure effective and safe treatment.


Assuntos
Antimônio , Arsênio , Humanos , Adulto , Criança , Ferro , Monitoramento Ambiental , Medição de Risco , Solo , Concentração de Íons de Hidrogênio
2.
Planta ; 258(5): 99, 2023 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-37837470

RESUMO

MAIN CONCLUSION: Integrated root phenotypes and transcriptome analysis have revealed key candidate genes responsible for maize root growth and development in potassium deficiency. Potassium (K) is a vital macronutrient for plant growth, but our understanding of its regulatory mechanisms in maize root system architecture (RSA) and K+ uptake remains limited. To address this, we conducted hydroponic and field trials at different growth stages. K+ deficiency significantly inhibited maize root growth, with metrics like total root length, primary root length, width and maximum root number reduced by 50% to 80% during early seedling stages. In the field, RSA traits exhibited maximum values at the silking stage but continued to decline thereafter. Furthermore, K deprivation had a pronounced negative impact on root morphology and RSA growth and grain yield. RNA-Seq analysis identified 5972 differentially expressed genes (DEGs), including 17 associated with K+ signaling, transcription factors, and transporters. Weighted gene co-expression network analysis revealed 23 co-expressed modules, with enrichment of transcription factors at different developmental stages under K deficiency. Several DEGs and transcription factors were predicted as potential candidate genes responsible for maize root growth and development. Interestingly, some of these genes exhibited homology to well-known regulators of root architecture or development in Arabidopsis, such as Zm00001d014467 (AtRCI3), Zm00001d011237 (AtWRKY9), and Zm00001d030862 (AtAP2/ERF). Identifying these key genes helps to provide a deeper understanding of the molecular mechanisms governing maize root growth and development under nutrient deficient conditions offering potential benefits for enhancing maize production and improving stress resistance through targeted manipulation of RSA traits in modern breeding efforts.


Assuntos
Deficiência de Potássio , Zea mays , Zea mays/metabolismo , Deficiência de Potássio/genética , Transcriptoma/genética , Melhoramento Vegetal , Perfilação da Expressão Gênica , Fatores de Transcrição/genética , Genes Reguladores , Crescimento e Desenvolvimento , Regulação da Expressão Gênica de Plantas
3.
Luminescence ; 2023 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-38013245

RESUMO

The aggregate luminescence behaviors of polymeric luminescent materials have been attracting great attention. However, the importance of the polymerization process on luminescence, namely, polymerization-induced emission (PIE), has rarely been overviewed. In this review, recent advances in polymerization with PIE effects are summarized, including PIE with aromatic rings based on one-/two-/multi-component polymerizations, and PIE without aromatic rings according to disparate mechanisms of polymerizations. Typical examples are selected to elaborate the basic design principles, as well as the properties and potential applications of the luminous polymers. Moreover, the challenges and perspectives in this area are also discussed.

4.
J Cell Physiol ; 237(1): 86-97, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34289095

RESUMO

Microtubule affinity regulating kinase 4 (MARK4), an important member of the serine/threonine kinase family, regulates the phosphorylation of microtubule-associated proteins and thus modulates microtubule dynamics. In human atherosclerotic lesions, the expression of MARK4 is significantly increased. Recently, accumulating evidence suggests that MARK4 exerts a proatherogenic effect via regulation of lipid metabolism (cholesterol, fatty acid, and triglyceride), inflammation, cell cycle progression and proliferation, insulin signaling, and glucose homeostasis, white adipocyte browning, and oxidative stress. In this review, we summarize the latest findings regarding the role of MARK4 in the pathogenesis of atherosclerosis to provide a rationale for future investigation and therapeutic intervention.


Assuntos
Aterosclerose , Proteínas Serina-Treonina Quinases , Aterosclerose/genética , Aterosclerose/metabolismo , Humanos , Microtúbulos/metabolismo , Fosforilação , Transdução de Sinais
5.
J Pineal Res ; 66(4): e12543, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30584671

RESUMO

Aflatoxin B1 (AFB1) is a major food and feed contaminant that threaten public health. Previous studies indicate that AFB1 exposure disrupted oocyte maturation. However, an effective and feasible method is unavailable for protecting oocytes against toxicity of AFB1. In the present study, using in vitro matured porcine oocytes and parthenogenetic embryos as model, we confirmed that AFB1 exposure during in vitro oocyte maturation (IVM) significantly impaired both nuclear and cytoplasmic maturation in a dose- and time-dependent manner. The different concentrations of melatonin were also tested for their protective effects on oocytes against the AFB1-induced toxicity. Our results showed that supplementation of a relative high concentration of melatonin (10-3 mol/L) during IVM efficiently reversed the impaired development rate and blastocyst quality, to the levels comparable to those of the control group. Further analysis indicated that melatonin application efficiently alleviated reactive oxygen species accumulation and initiation of apoptosis induced by AFB1 exposure. In addition, disrupted GSH/GPX system, as well as inhibited mitochondrial DNA (mtDNA) replication and mitochondrial biogenesis in AFB1-treated oocytes, can be notably reversed by melatonin application. Furthermore, cumulus cells may be important in mediating the toxicity of AFB1 to oocytes, and the metabolism of AFB1 in cumulus cells can be depressed by melatonin. To the best of our knowledge, this is the first report to confirm that melatonin application can efficiently protect oocytes from AFB1-induced toxicity. Our study provides a promising and practical strategy for alleviating or reversing AFB1-induced female reproductive toxicity in both clinical treatment and domestic reproductive management.


Assuntos
Aflatoxina B1/farmacologia , Técnicas de Maturação in Vitro de Oócitos , Melatonina/farmacologia , Oócitos/citologia , Oócitos/efeitos dos fármacos , Animais , Apoptose/efeitos dos fármacos , Células Cultivadas , Células do Cúmulo/citologia , Células do Cúmulo/efeitos dos fármacos , Células do Cúmulo/metabolismo , Variações do Número de Cópias de DNA/genética , Variações do Número de Cópias de DNA/fisiologia , DNA Mitocondrial/efeitos dos fármacos , Feminino , Glutationa/metabolismo , Marcação In Situ das Extremidades Cortadas , Oócitos/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Suínos
6.
Macromol Rapid Commun ; 38(9)2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28321938

RESUMO

Due to the axial group initiation in traditional (salen)CoX/quaternary ammonium catalyst system, it is difficult to construct single active center propagating polycarbonates for copolymerization of CO2 /epoxides. Here a redox-responsive poly(vinyl cyclohexene carbonate) (PVCHC) with detachable disulfide-bond backbone is synthesized in a controllable manner using (salen)CoTFA/[bis(triphenylphosphine)iminium, [PPN]TFA binary catalyst, where the axial group initiation is depressed by judiciously choosing 3,3'-dithiodipropionic acid as starter. While for those comonomers failing to obtain polycarbonate with unimodal gel permeation chromatography (GPC) curve, a versatile method is developed by combination of immortal copolymerization and prereaction approach, and functional aliphatic polycarbonates having well-defined architecture and narrow polydispersity can be prepared. The resulting PVCHC can be further functionalized with alkenes by versatile cross-metathesis reaction to tune the physicochemical properties. The combination of immortal polymerization and prereaction approach creates a powerful platform for controllable synthesis of functional CO2 -based polycarbonates.


Assuntos
Dióxido de Carbono/química , Técnicas de Química Analítica/métodos , Cimento de Policarboxilato/síntese química , Oxirredução , Cimento de Policarboxilato/química , Polimerização
7.
Reprod Fertil Dev ; 28(12): 1916-1925, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26111862

RESUMO

Intraperitoneal busulfan injections are used to prepare recipients for spermatogonial stem cell (SSC) transplantation but they are associated with haematopoietic toxicity. Testicular injections of busulfan have been proposed to overcome this limitation. To date, testicular injections have not been studied in the mouse model. Therefore, in the present study we used ICR mice as recipients for SSC transplantation and prepared these mice by testicular injection of busulfan on both sides (2, 3, 4 or 6mgkg-1 per side). Following this, donor germ cells expressing red fluorescent protein (RFP) from transgenic C57BL/6J male mice were transplanted into recipients via the efferent duct on Days 16-17 after busulfan treatment. Positive control mice were prepared by intraperitoneal injection of 40mgkg-1 busulfan and negative control mice were treated with bilateral testicular injection of 50% dimethyl sulfoxide. On Day 49 after transplantation, recipient mice that were RFP-positive by in vivo imaging were mated with ICR female mice. Donor-derived germ cell colonies with red fluorescence were observed on Day 60 after transplantation, and donor-derived offspring were obtained. The results demonstrated that endogenous germ cells were successfully eliminated in the seminiferous tubules via testicular busulfan administration, and that exogenous SSCs successfully undergo spermatogenesis in the testes of recipient mice prepared by testicular injections of busulfan. In addition to its effects on recipient preparation, this method was safe in rodents and could possibly be adapted for use in other species.


Assuntos
Bussulfano/administração & dosagem , Espermatogônias/transplante , Transplante de Células-Tronco , Testículo/efeitos dos fármacos , Animais , Feminino , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos ICR , Espermatogênese
8.
Ecotoxicol Environ Saf ; 133: 1-9, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27395817

RESUMO

Antimony (Sb) can pose great risks to the environment in mining and smelting areas. The migration of Sb in contaminated mine soil was studied using lysimeter experiments. The exchangeable concentration of soil Sb decreased with artificial leaching. The concentrations of Sb retained in the subsoil layers (5-25cm deep) were the highest for Isohumosol and Ferrosol and the lowest for Sandy soil. The Sb concentrations in soil solutions decreased with soil depth, and were adequately simulated using a logarithmic function. The Sb migration pattern in Sandy soil was markedly different from the patterns in the other soils which suggested that Sb may be transported in soil colloids. Environmental factors such as water content, soil temperature, and oxidation-reduction potential of the soil had different effects on Sb migration in Sandy soil and Primosol. The high Fe and Mn contents in Ferrosol and Isohumosol significantly decreased the mobility of Sb in these soils. The Na and Sb concentrations in soils used in the experiments positively correlated with each other (P<0.01). The Sb concentrations in soil solutions, the Sb chemical fraction patterns, and the Sb/Na ratios decreased in the order Sandy soil>Primosol>Isohumosol>Ferrosol, and we concluded that the Sb mobility in the soils also decreased in that order.


Assuntos
Antimônio/análise , Resíduos Industriais/análise , Mineração , Poluentes do Solo/análise , Solo/química , Poluição Ambiental/análise , Ferro/análise , Manganês/análise , Oxirredução , Sódio/análise , Solo/classificação , Solubilidade , Temperatura , Água/química
9.
Fa Yi Xue Za Zhi ; 30(4): 257-60, 2014 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-25434086

RESUMO

OBJECTIVE: To observe the effects of intermedin preconditioning on hypoxic injury in rat's cardiac myocytes and to provide the hypothetical mechanism of sudden cardiac death in the field of forensic pathology. METHODS: The H9c2 cultured rat cardiac myocytes were randomly divided into control group, hypoxia group and IMD group. The myocardial cell viability, cellular ultrastructure, intracellular calcium concentration and apoptosis rate were determined by MTT assay, transmission electron microscopy, laser scanning confocal microscope and flow cytometry, respectively. RESULTS: Compared with the control group, cell viability obviously decreased with inner ultrastructure injury in the hypoxia group (P<0.05), while cell viability significantly increased in the IMD group by reducing the hypoxia injury of cardiac myocytes (P<0.05). Compared with the control group, [Ca2+]i (fluorescence intensity) and apoptosis rate significantly increased in the hypoxia group, but decreased in the IMD group (P<0.05). CONCLUSION: IMD increases the cell survival rate and decreases the cell apoptosis inhibited by intracellular calcium overload from hypoxia. This finding may reveal the mechanism of protective effects of myocardial hypoxia, and provide a scientific basis for the identification sudden cardiac death.


Assuntos
Hipóxia Celular , Sobrevivência Celular , Hipóxia , Miocárdio/citologia , Miócitos Cardíacos/fisiologia , Animais , Apoptose , Cálcio , Isquemia Miocárdica , Ratos , Ratos Sprague-Dawley
10.
Polymers (Basel) ; 16(7)2024 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-38611241

RESUMO

A novel functional polycarbonate (PAGC), characterized by the presence of double bonds within its side chain, was successfully synthesized through a ternary copolymerization of propylene oxide (PO), allyl glycidyl ether (AGE), and carbon dioxide (CO2). Polyhedral oligomeric silsesquioxanes octamercaptopropyl (POSS-SH) was employed as a crosslinking agent, contributing to the formation of organic-inorganic hybrid materials. This incorporation was facilitated through thiol-ene click reactions, enabling effective interactions between the POSS molecules and the double bonds in the side chains of the polycarbonate. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) confirmed a homogeneous distribution of silicon (Si) and sulfur (S) in the polycarbonate matrix. The thiol-ene click reaction between POSS-SH and the polycarbonate led to a micro-crosslinked structure. This enhancement significantly increased the tensile strength of the polycarbonate to 42 MPa, a notable improvement over traditional poly (propylene carbonate) (PPC). Moreover, the cross-linked structure exhibited enhanced solvent resistance, expanding the potential applications of these polycarbonates in various plastic materials.

11.
J Colloid Interface Sci ; 668: 1-11, 2024 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-38669987

RESUMO

Hierarchical engineering of magnetic-dielectric composite microspheres has attracted increasing attention owing to its potential to enhance electromagnetic wave absorption (EMA) through magnetic-dielectric synergy. However, optimizing magnetic-dielectric balance in composite microspheres at the nanoscale remains a formidable task due to their limited component optimization and microstructural regulation. Herein, a novel approach is proposed to modify conventional carbonyl iron powder (CIP) microspheres via synergistic etching-assembly strategy. By applying a polydopamine coating, successive tannic acid (TA) etching-assembly, and pyrolysis, hierarchical iron@carbon-1/N-doped carbon (Fe@C-1/NC) composite microspheres are obtained. This overcomes the drawbacks of CIP microspheres, including their high density and poor impedance matching, which hinder EMA performance. Hierarchical carbon layer engineering can introduce abundant dipole centers, heterogeneous interfaces, and conductive networks to induce dielectric loss, while magnetic components contribute to magnetic resonance and eddy current loss, as demonstrated by the results. Accordingly, Fe@C-1/NC composite microspheres demonstrate a minimum reflection loss (RLmin) of -70.7 dB and an effective absorption bandwidth of 3.75 GHz at a matching thickness of 2.3 mm. Generally, this work paves the way towards CIP engineering to provide guidance to the future exploration of hierarchical magnetic-dielectric EMA materials.

12.
Anim Biosci ; 2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38754842

RESUMO

Objective: This study investigated the efficacy of different concentrations of Cholesterol-loaded cyclodextrin (CLC) on cryopreservation in boar sperm quality. Methods: In this study, we treated boar sperm with different concentrations of CLC before freezing and analyzed the sperm cholesterol concentration, plasma membrane, acrosome integrity rate and total motility rate before and after freeze-thawing. We also investigated the levels of reactive oxygen species (ROS), malondialdehyde (MDA), ATP, and structural- and oxidative-damage related proteins in all groups after thawing. Results: The results revealed that the cholesterol concentration of the CLC-treated groups was higher than that of the control group, both before freezing and after thawing (p < 0.05). The plasma membrane integrity rate, acrosome integrity rate, and total motility rate of sperm were also enhanced after thawing in the CLC-treated group (all p < 0.05). Moreover, ROS and MDA production and ATP loss were reduced in CLC-treated sperm during freezing and thawing (p < 0.05). Finally, CLC pretreatment partially prevented the consumption of various proteins involved in metabolism including CAPZB, HSP90AA1 and PGAM2 (p < 0.05). Conclusion: CLC treatment increased cholesterol concentration and decreased structural injury and oxidative damage during boar sperm freezing and thawing, improving the efficacy of sperm cryopreservation in boar.

13.
Guang Pu Xue Yu Guang Pu Fen Xi ; 33(2): 476-80, 2013 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-23697136

RESUMO

Adopting atomic absorption spectrometry (novAA400), the present study investigated the distribution characteristics of soil cadmium (Cd) in different textured paddy soil profiles under rice-wheat rotation and its correlation with Cd uptake by rice and wheat in Chengdu Plain through repeatedly taking soil and plant samples at the fixed sites in the field. The results revealed that Cd in the paddy soil profiles was mainly concentrated at the plough layer (0-15 cm) that obviously featured 'Cd accumulates towards the rooting layer'. Soil total Cd and available Cd (1 mol x L(-1) MgCl2 extraction) in the profile declined with soil depths and its average values at 30-45 cm only accounted for 47.60% and 39.49% of those at 0-15 cm. The potential downward movement of Cd in the different textured soil profiles was observed as sandy loam > heavy loam > loam. There was no significant correlation between soil pH and available Cd(r = - 0.46) at 0-15 cm soil depth, while significantly negative correlations between soil pH and available Cd were observed at 15-30 cm (r = -0.78) and 30-45 cm (r = -0.86). The results further demonstrated that the Cd contents in either grain or straw of rice and wheat were not well correlated with soil total Cd at any soil depth (r = -0.092-0.383 for rice and r = 0.174-0.424 for wheat), but significantly correlated with soil available Cd at 0-15 cm and at 15-30 cm (r = 0.766*-0.953**) despite insignificant correlation at 30-45 cm (r = 0.526-0.584). It is strongly suggested that the soil available Cd can be used as a better criterion than the total soil Cd to rate Cd contaminated soils in relation to safety of agricultural products.


Assuntos
Cádmio/análise , Produtos Agrícolas/crescimento & desenvolvimento , Poluentes do Solo/análise , Solo/química , Espectrofotometria Atômica/métodos , China , Monitoramento Ambiental , Oryza/crescimento & desenvolvimento , Triticum/crescimento & desenvolvimento
14.
Polymers (Basel) ; 15(3)2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36772049

RESUMO

The copolymerization of carbon dioxide (CO2) with epoxides demonstrates promise as a new synthetic method for low-carbon polymer materials, such as aliphatic polycarbonate materials. In this study, a binary Schiff base cobalt system was successfully used to catalyze the copolymerization of 1,2-butylene oxide (BO) and CO2 and its terpolymerization with other epoxides such as propylene oxide (PO) and cyclohexene oxide (CHO). 1H nuclear magnetic resonance (1H NMR), diffusion-ordered spectroscopy (DOSY), gel permeation chromatography (GPC), and differential scanning calorimetry (DSC) confirmed the successful synthesis of the alternating terpolymer. In addition, the effects of the polymerization reaction conditions and copolymerization monomer composition on the polymer structure and properties were examined systematically. By regulating the epoxide feed ratio, polycarbonates with an adjustable glass transition temperature (Tg) (11.2-67.8 °C) and hydrophilicity (water contact angle: 85.2-95.2°) were prepared. Thus, this ternary polymerization method provides an effective method of modulating the surface hydrophobicity of CO2-based polymers and their biodegradation properties.

15.
Appl Spectrosc ; 77(9): 1025-1032, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37448330

RESUMO

In a Fourier transform infrared (IR) spectrometer, the Michelson interference signal extrapolation method based on linear prediction is often used to improve spectral resolution. In this method, an autoregressive (AR) model is established for the Michelson interference signal in the spectrometer. Once the AR model parameters are determined, the AR process is predictable. The interference signal can be used to figure out the AR model's parameters. Based on this, the AR model can be used to extrapolate the interference signal to improve the spectral resolution. In this paper, the forward-backward linear prediction total least squares (FB-TLS) method is proposed to estimate the parameters of the AR model. The parameters that are estimated are used to improve the IR spectral resolution. By simulating different order and signal-to-noise ratio situations, the effects of the Burg, the least square, and the FB-TLS parameter estimation methods on spectral resolution enhancement are studied. The simulation results demonstrate that the FB-TLS parameter estimation method can effectively suppress noise and avoid spurious peaks. The experimental results demonstrate that the FB-TLS parameter estimation method is effective for spectral resolution enhancement technology based on linear prediction. When the FB-TLS method is used to enhance NH3 IR spectral resolution from 2 cm-1 to 1 cm-1, the spectral prediction error in the NH3 characteristic band is only 0.21% compared with the measured NH3 spectrum, whose spectral resolution is 1 cm-1.

16.
J Pharm Pharmacol ; 75(11): 1395-1404, 2023 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-37584490

RESUMO

Atherosclerosis is a lipid-driven chronic inflammatory disease that poses a serious threat to health. Legumain (LGMN), also known as asparagine endonuclease, is a new type of cysteine proteases that can specifically hydrolyze substrate molecules containing asparagine residues. It has anti-apoptotic effects in mammals and plays an antigen-presenting role in inflammatory response. Several studies have found that LGMN can activate multiple signal pathways to promote cell apoptosis and migration, inflammatory response, and the development of atherosclerosis. Importantly, LGMN exerts pro-atherogenic effects by participating in a variety of pathophysiological mechanisms of atherosclerosis, including vascular remodeling, inflammatory response, plaque stability, and the degradation of extracellular matrix. In the present review, we describe the LGMN distribution, structure, generation, and functional partners. Furthermore, we summarize the relationship between LGMN and atherosclerosis. Based on the relationship between LGMN and atherosclerosis, LGMN may be a potential biomarker for atherosclerosis.


Assuntos
Asparagina , Aterosclerose , Animais , Humanos , Cisteína Endopeptidases/metabolismo , Biomarcadores , Mamíferos/metabolismo
17.
Front Chem ; 11: 1202735, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37214483

RESUMO

The production of biodegradable polycarbonate by copolymerizing CO2 with epoxides has emerged as an effective method to utilize CO2 in response to growing concerns about CO2 emissions and plastic pollution. Previous studies have mainly focused on the preparation of CO2-based polycarbonates from petrochemical-derived propylene oxide (PO) or cyclohexene oxide (CHO). However, to reduce dependence on fossil fuels, the development of 100% bio-based polymers has gained attention in polymer synthesis. Herein, we reported the synthesis of glycidyl 4-pentenoate (GPA) from lignocellulose based 4-pentenoic acid (4-PA), which was further copolymerized with CO2 using a binary catalyst SalenCoCl/PPNCl to produce bio-based polycarbonates with vinyl side chains and molecular weights up to 17.1 kg/mol. Introducing a third monomer, PO, allows for the synthesis of the GPA/PO/CO2 terpolymer, and the glass transition temperature (T g) of the terpolymer can be adjusted from 2°C to 19°C by controlling the molar feeding ratio of GPA to PO from 7:3 to 3:7. Additionally, post-modification of the vinyl side chains enables the production of functional polycarbonates, providing a novel approach to the preparation of bio-based materials with diverse side chains and functions.

18.
Front Vet Sci ; 10: 1298132, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38274662

RESUMO

Follicular cysts are a common reproductive disorder in mammals that is usually caused by stress. However, the pathogenesis of follicular cysts in sows remains unclear. To provide new insights into the mechanisms of follicular cyst formation in pigs, we conducted a combined transcriptomic and metabolomic analysis on theca interna and mural granulosa cells of follicular cysts and mature follicles. We identified 2,533 up-regulated and 1,355 down-regulated genes in follicular cysts, compared with mature follicles. These differentially expressed genes were mainly found in signaling pathways related to tumor formation and cortisol synthesis and secretion as shown by Ingenuity Pathway Analysis, which predicted 4,362 upstream regulatory factors. The combined gene expression and pathway analysis identified the following genes as potential biomarkers for porcine follicular cysts: cytochrome P450 family 2 subfamily C polypeptide 18, L-lactate dehydrogenase, carbamoyl-phosphate synthase, fibroblast growth factor 7, integrin binding sialoprotein, interleukin 23 receptor, prolactin receptor, epiregulin, interleukin 1 receptor type II, arginine vasopressin receptor 1A, fibroblast growth factor 10, claudin 7, G Protein Subunit Gamma 3, cholecystokinin B receptor and cytosolic phospholipase A2. Metabolomics analysis found significant differences in 87 metabolites, which were enriched in unsaturated fatty acid biosynthesis, and sphingolipid signaling pathways. These results provide valuable information on the molecular mechanisms of follicular cyst formation, which may facilitate the development of new therapeutics to prevent and treat follicular cysts.

19.
J Colloid Interface Sci ; 650(Pt B): 1434-1445, 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-37481781

RESUMO

Magnetic-dielectric synergy is currently regarded as among the most effective approaches to achieve low-frequency electromagnetic wave absorption (EMA). However, designing and fabricating EMA materials with tunable magnetic-dielectric balance towards high-performance low-frequency EMA remains challenging. Herein, a polymer self-assembly guided heterogeneous structure engineering strategy is proposed to fabricate hierarchical magnetic-dielectric nanocomposite. Polymer assemblies not only can be employed as intermediates to encapsulate metal-organic frameworks and load metal hydroxide, but also that they play a crucial role for the in-situ formation of polycrystalline FeCo/Co composite nanoparticles. As a result, the minimum reflection loss (RLmin) can reach -59.61 dB at 5.4 GHz (4.8 mm) with a 20 wt% filler loading, while the effective absorption bandwidth (EAB, RLmin ≤ -10 dB) is 2.16 GHz, exhibiting excellent low-frequency EMA performance. Systematic investigations demonstrate that hierarchical mesoporous carbon matrix that supports FeCo/Co composite nanoparticles is beneficial for optimizing impedance matching and increasing attenuation capacity. In general, this study opens up new prospects for developing magnetic-dielectric EMA materials using a polymer self-assembly guided heterogeneous structure engineering strategy, which may receive significant attention in future research.

20.
Animals (Basel) ; 13(21)2023 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-37958056

RESUMO

After estrus, when mature follicles fail to ovulate, they may further develop to form follicular cysts, affecting the normal function of ovaries, reducing the reproductive efficiency of dairy cows and causing economic losses to cattle farms. However, the key points of ovarian follicular cysts pathogenesis remain largely unclear. The purpose of the current research was to analyze the formation mechanism of ovarian follicular cysts from hormone and gene expression profiles. The concentrations of progesterone (P4), estradiol (E2), insulin, insulin-like growth factor 1 (IGF1), leptin, adrenocorticotropic hormone (ACTH) and ghrelin in follicle fluid from bovine follicular cysts and normal follicles were examined using enzyme-linked immunosorbent assay (ELISA) or 125I-labeled radioimmunoassay (RIA); the corresponding receptors' expression of theca interna cells was tested via quantitative reverse transcription polymerase chain reaction (RT-qPCR), and the mRNA expression profiling was analyzed via RNA sequencing (RNA-seq). The results showed that the follicular cysts were characterized by significant lower E2, insulin, IGF1 and leptin levels but elevated ACTH and ghrelin levels compared with normal follicles (p < 0.05). The mRNA expressions of corresponding receptors, PGR, ESR1, ESR2, IGF1R, LEPR, IGFBP6 and GHSR, were similarly altered significantly (p < 0.05). RNA-seq identified 2514 differential expressed genes between normal follicles and follicular cysts. The Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis linked the ovarian steroidogenesis pathway, especially the STAR, 3ß-HSD, CYP11A1 and CYP17A1 genes, to the formation of follicular cysts (p < 0.01). These results indicated that hormone metabolic disorders and abnormal expression levels of hormone synthesis pathway genes are associated with the formation of bovine ovarian follicular cysts.

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