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1.
J Hazard Mater ; 475: 134903, 2024 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-38878441

RESUMO

Copper is one of the unavoidable heavy metals in wine production. In this study, the effects on fermentation performance and physiological metabolism of Saccharomyces cerevisiae under copper stress were investigated. EC1118 was the most copper-resistant among the six strains. The ethanol accumulation of EC1118 was 26.16-20 mg/L Cu2+, which was 1.90-3.15 times higher than that of other strains. The fermentation rate was significantly reduced by copper, and the inhibition was relieved after 4-10 days of adjustment. Metabolomic-transcriptomic analysis revealed that amino acid and nucleotide had the highest number of downregulated and upregulated differentially expressed metabolites, respectively. The metabolism of fructose and mannose was quickly affected, which then triggered the metabolism of galactose in copper stress. Pathways such as oxidative and organic acid metabolic processes were significantly affected in the early time, resulting in a significant decrease in the amount of carboxylic acids. The pathways related to protein synthesis and metabolism under copper stress, such as translation and peptide biosynthetic process, was also significantly affected. In conclusion, this study analyzed the metabolite-gene interaction network and molecular response during the alcohol fermentation of S. cerevisiae under copper stress, providing theoretical basis for addressing the influence of copper stress in wine production.


Assuntos
Cobre , Etanol , Fermentação , Saccharomyces cerevisiae , Transcriptoma , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/genética , Cobre/toxicidade , Etanol/toxicidade , Etanol/metabolismo , Transcriptoma/efeitos dos fármacos , Metabolômica , Vinho , Perfilação da Expressão Gênica
2.
Front Chem ; 12: 1417763, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38887698

RESUMO

Introduction: Facial nerve injury significantly impacts both the physical and psychological] wellbeing of patients. Despite advancements, there are still limitations associated with autografts transplantation. Consequently, there is an urgent need for effective artificial grafts to address these limitations and repair injuries. Recent years have witnessed the recognition of the beneficial effects of chitosan (CS) and graphene in the realm of nerve repair. Dental pulp stem cells (DPSCs) hold great promise due to their high proliferative and multi-directional differentiation capabilities. Methods: In this study, Graphene/CS (G/CST) composite tubes were synthesized and their physical, chemical and biological properties were evaluated, then DPSCs were employed as seed cells and G/CST as a scaffold to investigate their combined effect on promoting facial nerve injury repair. Results and Disscussion: The experimental results indicate that G/CST possesses favorable physical and chemical properties, along with good cyto-compatibility. making it suitable for repairing facial nerve transection injuries. Furthermore, the synergistic application of G/CST and DPSCs significantly enhanced the repair process for a 10 mm facial nerve defect in rabbits, highlighting the efficacy of graphene as a reinforcement material and DPSCs as a functional material in facial nerve injury repair. This approach offers an effective treatment strategy and introduces a novel concept for clinically managing facial nerve injuries.

3.
Front Pharmacol ; 15: 1256649, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38860173

RESUMO

Background: Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive interstitial lung disease of unknown etiology. Pirfenidone (PFD) and nintedanib (NDN) were both conditionally recommended in the clinical practice guideline published in 2015. Safety and tolerability are related to the risk of treatment discontinuation. Therefore, this study evaluated and compared the adverse events (AEs) of PFD and NDN in a large real-world population by analyzing data from the FDA Adverse Event Reporting System (FAERS) to provide a reference for their rational and safe use. Methods: The AEs of PFD and NDN were extracted from the FAERS database. The pharmacovigilance online analysis tool OpenVigil 2.1 was used to retrieve data from the FAERS database from the first quarter of 2012 to the second quarter of 2022. The reporting odds ratio (ROR) and proportional reporting ratio were used to detect the risk signals. Results: The database included 26,728 and 11,720 reports for PFD and NDN, respectively. The most frequent AEs of PFD and NDN were gastrointestinal disorders. The RORs for these drugs were 5.874 and 5.899, respectively. "Cardiac disorders" was the most statistically significant system order class for NDN with an ROR of 9.382 (95% confidence interval = 8.308-10.594). Furthermore, the numbers of designated medical events of PFD and NDN were 552 and 656, respectively. Notably, liver injury was reported more frequently for NDN (11.096%) than for PFD (6.076%). Conclusion: This study revealed differences in the reporting of AEs between PFD and NDN. The findings provide reference for physicians in clinical practice. Attention should be paid to the risks of cardiac disorders and liver injury associated with NDN.

4.
Small Methods ; : e2400214, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38888380

RESUMO

Controllable fabrication of formamidinium (FA)-based perovskite solar cells (PSCs) with both high efficiency and long-term stability is the key to their further commercialization. However, the diversity of PbI2 complexes and perovskite compositions usually leads to light sensitive PbI2 residues and phase impurities in the film, which can accelerate the device degradation. Here, the crystallization kinetics of FA-based perovskite films are studied and a bridging-solvent strategy is proposed to modulate the reaction kinetics between PbI2 and ammonium salts by prohibiting the formation of undesired intermediates. N-methylpyrrolidone (NMP) solvent is introduced into the PbI2 precursor solution to obtain stable and homogeneous PbI2-NMP complex films. The strong interaction between NMP and formamidinium iodide (FAI) molecules promotes the conversion from PbI2-NMP into (001)-oriented quasi-single-crystal perovskite films with negligible impurities, long carrier lifetime of 1.5 µs and a large grain size of 3 µm. The optimized PSCs exhibit a high power conversion efficiency of 24.1%, as well as superior shelf stability which maintains 95% initial efficiency after storage in air for 1200 h (T95 = 1200 h), and operating stability with T96 = 300 h under continuous working at the maximum power point. This work offers a simple and reproducible method for fabricating phase-pure and uniaxially oriented perovskite films.

6.
Int Immunopharmacol ; 134: 112259, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38749336

RESUMO

Alzheimer's disease (AD) is a progressive neurodegenerative disease. Neuronal calcium overload plays an important role in Aß deposition and neuroinflammation, which are strongly associated with AD. However, the specific mechanisms by which calcium overload contributes to neuroinflammation and AD and the relationship between them have not been elucidated. Phospholipase C (PLC) is involved in regulation of calcium homeostasis, and CN-NFAT1 signaling is dependent on intracellular Ca2+ ([Ca2+]i) to regulate transcription of genes. Therefore, we hypothesized that the PLC-CN-NFAT1 signaling might mediate the interaction between Aß and inflammation to promote neuronal injury in AD. In this experiment, the results showed that the levels of Aß, IL-1ß and [Ca2+]i in the hippocampal primary neurons of APP/PS1 mice (APP neurons) were significantly increased. IL-1ß exposure also significantly increased Aß and [Ca2+]i in HT22 cells, suggesting a close association between Aß and IL-1ß in the development of AD. Furthermore, PLC activation induced significant calcium homeostasis imbalance, cell apoptosis, Aß and ROS production, and significantly increased expressions of CN and NFAT1, while PLC inhibitor significantly reversed these changes in APP neurons and IL-1ß-induced HT22 cells. Further results indicated that PLC activation significantly increased the expressions of NOX2, APP, BACE1, and NCSTN, which were inhibited by PLC inhibitor in APP neurons and IL-1ß-induced HT22 cells. All indications point to a synergistic interaction between Aß and IL-1ß by activating the PLC-CN-NFAT1 signal, ultimately causing a vicious cycle, resulting in neuronal damage in AD. The study may provide a new idea and target for treatment of AD.


Assuntos
Doença de Alzheimer , Peptídeos beta-Amiloides , Hipocampo , Interleucina-1beta , Fatores de Transcrição NFATC , Neurônios , Transdução de Sinais , Fosfolipases Tipo C , Animais , Hipocampo/metabolismo , Hipocampo/patologia , Interleucina-1beta/metabolismo , Neurônios/metabolismo , Neurônios/patologia , Fatores de Transcrição NFATC/metabolismo , Camundongos , Fosfolipases Tipo C/metabolismo , Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/metabolismo , Calcineurina/metabolismo , Camundongos Transgênicos , Cálcio/metabolismo , Linhagem Celular , Humanos , Células Cultivadas , Apoptose , Espécies Reativas de Oxigênio/metabolismo , Camundongos Endogâmicos C57BL , Precursor de Proteína beta-Amiloide/metabolismo , Precursor de Proteína beta-Amiloide/genética
7.
J Biomater Sci Polym Ed ; 35(10): 1550-1570, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38630632

RESUMO

In recent years, mouse nerve growth factor (mNGF) has emerged as an important biological regulator to repair peripheral nerve injury, but its systemic application is restricted by low efficiency and large dosage requirement. These limitations prompted us to search for biomaterials that can be locally loaded. Oxidized sodium alginate hydrogel (OSA) exhibits good biocompatibility and physicochemical properties, and can be loaded with drugs to construct a sustained-release system that can act locally on nerve injury. Here, we constructed a sustained-release system of OSA-mouse nerve growth factor (mNGF), and investigated the loading and release of the drug through Fourier transform infrared spectroscopy and drug release curves. In vitro and in vivo experiments showed that OSA-mNGF significantly promoted the biological activities of RSC-96 cells and facilitated the recovery from sciatic nerve crush injury in rats. This observation may be attributed to the additive effect of OSA on promoting Schwann cell biological activities or its synergistic effect of cross-activating phosphoinositide 3-kinase (PI3K) through extracellular signal regulated kinase (ERK) signaling. Although the specific mechanism of OSA action needs to be explored in the future, the current results provide a valuable preliminary research basis for the clinical application of the OSA-mNGF sustained-release system for nerve repair.


Assuntos
Alginatos , Preparações de Ação Retardada , Liberação Controlada de Fármacos , Hidrogéis , Fator de Crescimento Neural , Traumatismos dos Nervos Periféricos , Alginatos/química , Alginatos/farmacologia , Animais , Fator de Crescimento Neural/química , Preparações de Ação Retardada/química , Camundongos , Hidrogéis/química , Hidrogéis/farmacologia , Ratos , Traumatismos dos Nervos Periféricos/tratamento farmacológico , Traumatismos dos Nervos Periféricos/metabolismo , Células de Schwann/efeitos dos fármacos , Células de Schwann/metabolismo , Nervo Isquiático/lesões , Nervo Isquiático/efeitos dos fármacos , Regeneração Nervosa/efeitos dos fármacos , Oxirredução , Linhagem Celular , Masculino , Ratos Sprague-Dawley , Portadores de Fármacos/química , Fosfatidilinositol 3-Quinases/metabolismo
8.
Adv Sci (Weinh) ; 11(19): e2401184, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38467038

RESUMO

Perovskite films with large crystal size, preferred orientation, and facile fabrication process, combining advantages of single-crystal and polycrystalline films, have gained considerable attention recently. However, there is little research on the facet properties of perovskite films. Here, (111)- and (001)-oriented perovskite films with bandgaps ranging from 1.53 to 1.77 eV, and systematically investigated their orientation-dependent properties are achieved. The (111)-oriented films show electron-dominated traps and the (001)-oriented films show hole-dominated traps, which are related to their atomic arrangement at the surface. Compared with the (001)-oriented films, the (111)-oriented films exhibit lower work function and superior water/oxygen robustness. For the wide-bandgap films, the lattice of the (001)-oriented film provides an unobstructed passage for ion migration. Comparably, the (111)-oriented films exhibit suppressed ion migration and excellent phase stability. The optimized unencapsulated solar cells based on both (001) and (111) orientations show a similar high efficiency of ≈23%. The (111)-oriented solar cell exhibits excellent stability, maintaining 95% of its initial efficiency after 1500 h maximum power point (MPP) tracking test, and 97% initial efficiency after 3000 h aging in ambient conditions. This work paves the way for the rational design, controllable synthesis, and targeted optimization of uniaxial-oriented perovskite films for various electronic applications.

9.
Microb Pathog ; 190: 106633, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38554778

RESUMO

Interferon-stimulated gene product 15 (ISG15) can be conjugated to substrates through ISGylation. Currently, the E3 ligase for porcine ISGylation remains unclear. Here, we identified porcine HERC5 and HERC6 (pHERC5/6) as ISGylation E3 ligases with pHERC6 acting as a major one by reconstitution of porcine ISGylation system in HEK-293 T cell via co-transfecting E1, E2 and porcine ISG15(pISG15) genes. Meanwhile, our data demonstrated that co-transfection of pISG15 and pHERC5/6 was sufficient to confer ISGylation, suggesting E1 and E2 of ISGylation are interchangeable between human and porcine. Using an immunoprecipitation based ISGylation analysis, our data revealed pHERC6 was a substrate for ISGylation and confirmed that K707 and K993 of pHERC6 were auto-ISGylation sites. Mutation of these sites reduced pHERC6 half-life and inhibited ISGylation, suggesting that auto-ISGylation of pHERC6 was required for effective ISGylation. Conversely, sustained ISGylation induced by overexpression of pISG15 and pHERC6 could be inhibited by a well-defined porcine ISGylation antagonist, the ovarian tumor (OTU) protease domain of Porcine Reproductive and Respiratory Syndrome Virus (PRRSV)-nsp2 and PRRSV-nsp1ß, further indicating such method could be used for identification of virus-encoded ISG15 antagonist. In conclusion, our study contributes new insights towards porcine ISGylation system and provides a novel tool for screening viral-encoded ISG15 antagonist.


Assuntos
Ubiquitina-Proteína Ligases , Ubiquitinas , Animais , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitina-Proteína Ligases/genética , Suínos , Humanos , Células HEK293 , Ubiquitinas/metabolismo , Ubiquitinas/genética , Vírus da Síndrome Respiratória e Reprodutiva Suína/metabolismo , Vírus da Síndrome Respiratória e Reprodutiva Suína/genética , Citocinas/metabolismo , Ubiquitinação , Proteínas não Estruturais Virais/metabolismo , Proteínas não Estruturais Virais/genética
10.
Vet Microbiol ; 292: 110035, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38484577

RESUMO

Porcine reproductive and respiratory syndrome virus (PRRSV) poses a significant threat to the global pork industry, resulting in substantial economic losses. Current control measures rely on modified live virus (MLV) vaccines with safety concerns. However, the lack of consensus on protective PRRSV antigens is impeding the development of effective and safety subunit vaccines. In this study, we conducted in vitro virus neutralization (VN) assays in MARC-145 and CRL-2843CD163/CD169 cell lines and primary porcine alveolar macrophages (PAMs) to systemically identify PRRSV structural proteins (SPs) recognized by virus-neutralizing antibodies in hyperimmune serum collected from piglets infected with highly pathogenic PRRSV (HP-PRRSV). Additionally, piglets immunized with different combinations of recombinant PRRSV-SPs were challenged with HP-PRRSV to evaluate their in vivo protection potential. Intriguingly, different in vitro VN activities of serum antibodies elicited by each PRRSV SP were observed depending on the cell type used in the VN assay. Notably, antibodies specific for GP3, GP4, and M exhibited highest in vitro VN activities in PAMs, correlating with complete protection (100% survival) against HP-PRRSV challenge in vivo after immunization of piglets with combination of GP3, GP4, M and N (GP3/GP4/M/N). Further analysis of lung pathology, weight gain, and viremia post-challenge revealed that the combination of GP3/GP4/M/N provided superior protective efficacy against severe infection. These findings underscore the potential of this SP combination to serve as an effective PRRSV subunit vaccine, marking a significant advancement in pork industry disease management.


Assuntos
Guanidinas , Piperazinas , Síndrome Respiratória e Reprodutiva Suína , Vírus da Síndrome Respiratória e Reprodutiva Suína , Doenças dos Suínos , Vacinas Virais , Animais , Suínos , Síndrome Respiratória e Reprodutiva Suína/prevenção & controle , Macrófagos Alveolares , Anticorpos Antivirais
11.
Heliyon ; 10(4): e26290, 2024 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-38434074

RESUMO

During the welding process, temperature filed distribution of weldment is one of the key factors which influence welding quality. In order to improve the mechanical properties of welding joint, a technology for heating process of weldment using auxiliary pulse current was proposed in this article. Firstly, through metallographic experiment, strength experiment and hardness experiment, it was proved that the auxiliary pulse current not only can refine grain size but also improves the mechanical property of the welding joint. Then the paper used ANSYS and its ANSYS Parametric Design Language parametric design language to simulate the welding process with assistant pulse current, and the temperature field, the pulse current density distribution and the time of effective pulse current in the welded joint were obtained. Quantitative analyses were undertaken on the influence laws of auxiliary pulse current parameters on weld temperature field, auxiliary pulse current density distribution and the time of effective pulse current. A new parameter was defined as time-current density (the time integral of current density) to demonstrate the change rule of auxiliary pulse current density distribution with time. Finally, analyzing the reasons for raising the welding quality. There were two reasons for such phenomenon: one was auxiliary pulse current change the state of heat distribution in the weld seam area, the other was that the impulse oscillation of the auxiliary pulse influences the nucleation process of melting region.

12.
Molecules ; 29(3)2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38338311

RESUMO

The prevalence of facial nerve injury is substantial, and the restoration of its structure and function remains a significant challenge. Autologous nerve transplantation is a common treatment for severed facial nerve injury; however, it has great limitations. Therefore, there is an urgent need for clinical repair methods that can rival it. Tissue engineering nerve conduits are usually composed of scaffolds, cells and neurofactors. Tissue engineering is regarded as a promising method for facial nerve regeneration. Among different factors, the porous nerve conduit made of organic materials, which has high porosity and biocompatibility, plays an indispensable role. This review introduces facial nerve injury and the existing treatment methods and discusses the necessity of the application of porous nerve conduit. We focus on the application of porous organic polymer materials from production technology and material classification and summarize the necessity and research progress of these in repairing severed facial nerve injury, which is relatively rare in the existing articles. This review provides a theoretical basis for further research into and clinical interventions on facial nerve injury and has certain guiding significance for the development of new materials.


Assuntos
Traumatismos do Nervo Facial , Engenharia Tecidual , Humanos , Engenharia Tecidual/métodos , Traumatismos do Nervo Facial/terapia , Porosidade , Próteses e Implantes , Polímeros , Regeneração Nervosa , Alicerces Teciduais
13.
Environ Res ; 248: 118267, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38244969

RESUMO

In recent years, the utilization of wastewater recycling as an alternative water source has gained significant traction in addressing urban water shortages. Accurate prediction of wastewater quantity is paramount for effective urban river water resource management. There is an urgent need to develop advanced forecasting technologies to further enhance the accuracy and efficiency of water quantity predictions. Decomposition ensemble models have shown excellent predictive capabilities but are challenged by boundary effects when decomposing the original data sequence. To address this, a rolling forecast decomposition ensemble scheme was developed. It involves using a machine learning (ML) model for prediction and progressively integrating prediction outcomes into the original sequence using complementary ensemble empirical mode decomposition with adaptive noise (CEEMDAN). Long short-term memory (LSTM) is then applied for sub-signal prediction and ensemble. The ML-CEEMDAN-LSTM model was introduced for wastewater quantity prediction, compared with non-decomposed ML models, CEEMDAN-based LSTM models, and ML-CEEMDAN-based LSTM models. Three ML algorithms-linear regression (LR), gradient boosting regression (GBR), and LSTM-were examined, using real-time prediction data and historical monitoring data, with historical data selected using the decision tree method. The study used daily water volumes data from two reclaimed water plants, CH and WQ, in Beijing. The results indicate that (1) ML models varied in their selection of real-time factors, with LR performing best among ML models during testing; (2) the ML-CEEMDAN-LSTM model consistently outperformed ML models; (3) the ML-CEEMDAN-LSTM hybrid model performed better than the CEEMDAN-LSTM model across different seasons. This study offers a reliable and accurate approach for reclaimed water volumes forecasting, critical for effective water environment management.


Assuntos
Rios , Água , Conservação dos Recursos Naturais , Águas Residuárias , Água Doce , Previsões
14.
BMC Psychiatry ; 24(1): 90, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38297253

RESUMO

BACKGROUND: A lack of confidence in perinatal bereavement care (PBC) and the psychological trauma experienced by nurses and midwives during bereavement care leads to their strong need for sufficient organisational support. The current study intended to test a hypothesised model of the specific impact paths among organisational support, confidence in PBC, secondary traumatic stress, and emotional exhaustion among nurses and midwives. METHODS: A descriptive, cross-sectional survey was conducted in sixteen maternity hospitals in Zhejiang Province, China, from August to October 2021. The sample (n = 779) consisted of obstetric nurses and midwives. A path analysis was used to test the relationships among study variables and assess model fit. RESULTS: Organisational support directly and positively predicted confidence in PBC and demonstrated a direct, negative, and significant association with secondary traumatic stress and emotional exhaustion. Confidence in PBC had a positive direct effect on secondary traumatic stress and a positive indirect effect on emotional exhaustion via secondary traumatic stress. Secondary traumatic stress exhibited a significant, direct effect on emotional exhaustion. CONCLUSIONS: This study shows that nurses' and midwives' confidence in PBC and mental health were leadingly influenced by organisational support in perinatal bereavement practice. It is worth noting that higher confidence in PBC may lead to more serious psychological trauma symptoms in nurses and midwives. Secondary traumatic stress plays an essential role in contributing to emotional exhaustion. The findings suggest that support from organisations and self-care interventions were required to improve confidence in PBC and reduce negative psychological outcomes among those providing PBC. The development of objective measures for assessing competence in PBC and organizational support are essential.


Assuntos
Luto , Esgotamento Profissional , Fadiga de Compaixão , Cuidados Paliativos na Terminalidade da Vida , Tocologia , Humanos , Feminino , Gravidez , Exaustão Emocional , Estudos Transversais , China , Inquéritos e Questionários
15.
Int J Biol Macromol ; 254(Pt 2): 127720, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37913882

RESUMO

Bacterial infection of wounds remains one of the major clinical challenges, calling for the urgent development of novel multifunctional biological dressings. In this study, we developed a chitosan-based supramolecular aerogel NADES/PVA/CS, constructed by hydrogen bonding between chitosan, a natural deep eutectic solvents and polyvinyl alcohol, as a novel wound dressing against bacterial infections. The effect of polyvinyl alcohol content and its incorporation within chitosan-based supramolecular aerogels were investigated. The results of antibacterial test and MTT assay showed that it has obvious inhibitory effect on Staphylococcus aureus and Escherichia coli, showing excellent biocompatibility and effectively promotes wound healing. The microstructure of chitosan-based supramolecular aerogel showed that by adjusting the addition amount of polyvinyl alcohol, it could exhibit a perfect skeleton-type 3D network structure, which also made it possess smaller density and larger porosity and exhibit excellent water absorption property, contributing to the wetting of wound surface. More importantly, chitosan-based supramolecular aerogel is an environment-friendly biomaterial, which has been verified by degradability experiment. In a word, these unique advantages provide a broad prospect for the medical application of chitosan-based supramolecular aerogel NADES/PVA/CS, and provide a new strategy for the construction of green polysaccharide medical materials.


Assuntos
Quitosana , Quitosana/química , Solventes Eutéticos Profundos , Álcool de Polivinil/química , Antibacterianos/farmacologia , Antibacterianos/química , Escherichia coli , Bandagens
16.
Sci Total Environ ; 912: 168875, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38013095

RESUMO

With accelerating anthropogenic activities, the overloading of land-derived nutrients and the resultant eutrophication are threatening coastal aquatic habitats worldwide. In semi-enclosed coastal bays, eutrophication is always considered a local problem that can be mitigated by nutrient reduction at a regional scale. However, as the main nutrient drains major global river discharges can have far-reaching effects over hundreds of kilometers alongshore, which are usually not precisely recognized in local coastal zone management. Here, we first quantified the contributions from both local and remote nutrient sources in Xiangshan Bay (XSB), a eutrophic semi-enclosed bay in China 200 km south of the mouth of the Changjiang River (CJR, the world's third largest river), employing a salinity-based conservative mixing model. We found that the nutrients in Xiangshan Bay were mainly supplied by intruded coastal water fed by CJR discharge, contributing 63 % of dissolved inorganic nitrogen (DIN), 65 % of dissolved silicon (DSi), and 49 % of dissolved inorganic phosphorus (DIP) during the summer of 2017, and 75 % of DIN, 75 % of DSi and 60 % of DIP during the winter of 2019. Additionally, long-term interannual trends in the nutrient concentrations of XSB were generally synchronous with those of the downstream portion of the CJR, indicating that CJR discharge seems to be a strong driver of the eutrophication observed in XSB. In contrast, the impact of local nutrient inputs, such as riverine sewage drainage, aquaculture, biogenic activities, and elemental recycling, was much lower and was regionally limited to the inner bay. Interestingly, the DIP contributions of the local and remote sources were similar, indicating the greater relevance of the internal process. Overall, to mitigate eutrophication in large river-adjacent coastal bays, the inter-regional united practices for nutrient source regulation and ecosystem restoration should be permanently applied along the entire river basin-estuary-coastal continuum.

17.
Int J Biol Macromol ; 255: 127698, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37949277

RESUMO

A large number of hydrogen bonds is the main reason for hindering the dissolution and reaction of chitin, and a mild and green deacetylation method to prepare chitosan for a wider range of applications is urgent. As a non-toxic and degradable green solvent, the deep eutectic solvent can effectively interfere with the hydrogen bond network of chitin, making chitin more susceptible to other solvents. Therefore, a NADES system consisting of betaine and glycerol was proposed for application in the deacetylation reaction of chitin to facilitate further attack of N-acetyl groups by low concentrations of NaOH. After optimizing the reaction conditions, chitosan with 83.77 % deacetylation was prepared, requiring only a concentration of 25 wt% NaOH. The analysis of the product chitosan showed that NADES could not only effectively improve the degree of deacetylation, but also reduce the degree of damage to the molecular weight by alkali. In addition, the potential mechanisms involved in the deacetylation process by NADES were explored. The nature of the reaction was verified by FT-IR, XRD and theoretical calculations as the process of opening intra/intermolecular hydrogen bonds of chitin by NADES. More importantly, experimental and in-depth theoretical studies provide a reference for the green preparation of chitosan.


Assuntos
Quitina , Quitosana , Quitina/química , Solventes/química , Quitosana/química , Solventes Eutéticos Profundos , Hidróxido de Sódio , Espectroscopia de Infravermelho com Transformada de Fourier
18.
Opt Lett ; 49(1): 33-36, 2024 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-38134145

RESUMO

High-gain materials and high-quality structures are the two main conditions that determine the amplification performance of optical waveguides. However, it has been hard to balance each other, to date. In this work, we demonstrate breakthroughs in both glass optical gain and optical waveguide structures. We propose a secondary melting dehydration technique that prepares high-quality Er3+-Yb3+ co-doped phosphate glass with low absorption loss. Additionally, we propose a femtosecond laser direct-writing technique that allows controlling the cross section, size, and mode field of waveguides written in glass with high accuracy, leveraging submicron-resolution multi-scan direct-writing optical waveguide technology, which is beneficial for reducing insertion loss. As a proof of concept demonstration, we designed and fabricated two kinds of waveguides, namely, LP01- and LP11-mode waveguides in the Er3+-Yb3+ co-doped phosphate glass, enabling insertion loss as low as 0.9 dB for a waveguide length of 2 mm. Remarkably, we successfully achieved an optical amplification for both the waveguides with a net gain of >7 dB and a net-gain coefficient of >3.5 dB/mm, which is approximately one order of magnitude larger than that in the Er3+-Yb3+ co-doped phosphate glass fabricated by the traditional melt-quenching method. This will open new avenues toward the development of integrated photonic chips.

19.
Int J Biol Macromol ; 258(Pt 1): 128920, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38141697

RESUMO

Chinese steamed bread (CSB), a conventional high-GI staple food, with a short shelf life and a single flavor. In this work, 10-20 % kiwi starch (KS) was used to substitute wheat flour for the production of CSB and the effects of different substitution ratios on the quality and shelf life of mixed flour, dough, and CSB were explored. The results showed that the substitution of KS could improve the water binding capacity of mixed flour and lead to easier pasting in the system, lower the cooking power consumption, increase and improve the viscoelasticity and gas holding capacity of the dough, and make the microstructure more compact and uniform. As the substitution ratio increased, the reduction in protein content within the system further affected the formation of the gluten network, leading to a significant decrease in the CSB's specific volume and cohesiveness, whereas the chewiness and hardness were significantly improved. Meanwhile, KS substitution significantly reduced the starch hydrolysis rate and estimated glycemic index of CSB. 10 % KS substitution enriched the aroma and color of CSB, improved its internal organizational structure, and became more popular among consumers. A substitution ratio of 15-20 % was beneficial for extending the shelf life of CSB.


Assuntos
Pão , Farinha , Farinha/análise , Pão/análise , Amido/química , Triticum/química , Vapor , Reologia , China
20.
Anal Chem ; 95(50): 18470-18478, 2023 12 19.
Artigo em Inglês | MEDLINE | ID: mdl-38051701

RESUMO

Blood is one of the most frequent and valuable traces encountered at crime scenes, where knowing the time since deposition (TSD) of bloodstains tremendously assists forensic experts to screen out crime-related evidence and aids in the reconstruction of the event sequence. Although increasing proof-of-concept methodologies for investigating the TSD of bloodstains have been reported, there is still no accepted strategy in forensic practice as the aging mechanism involves complex components, leading to the inaccuracy of the estimation results. Herein, an endogenous biomarker of alkaline phosphatase (ALP) was chosen to investigate the TSD by scanning electrochemical microscopy (SECM). Results demonstrate that the ALP activity acquired via SECM lateral scan assay exhibited a clear decrease over time, and a similar trend was observed on both poly(vinylidene fluoride) (PVDF) membrane and glass, with the aging kinetics on PVDF membrane being faster than glass. By means of quantitatively calculating the flux of generated p-aminophenol (PAP), we established the aging curve and realized the TSD estimation of blood fingerprints (BFPs) that was unable to be distinguished via optical measurements. Intriguingly, the as-obtained estimation accuracy ranged from 74.6 to 93.7%, proving the possibility of using an ALP biomarker and SECM. More appealingly, the predicted TSDs were capable of accurately differentiating the deposition sequence of overlapping BFPs, which was hardly achieved by optical means. Therefore, this proof-of-concept strategy demonstrates the value of SECM as a forensic tool and opens possibilities for revealing multidimensional information about crime.


Assuntos
Fosfatase Alcalina , Polivinil , Microscopia Eletroquímica de Varredura , Biomarcadores
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