Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.803
Filtrar
1.
Sci Rep ; 14(1): 21972, 2024 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-39304680

RESUMO

The recent investigation targets to use adapted carbon paste (CP) with copper nanoparticles (CuNs) operating in a phosphate buffer (PBS) medium with a pH range of 5.0-8.0, to synthesize a novel, susceptible, and simple electrochemical sensor for the detection of one of the most important drugs, vitamin B6. Copper (Cu) is one of the most three common essential trace elements found in the bodies of both humans and animals, along with iron and zinc for all crucial physiological and biochemical functions. Its properties, which are assessed using a variety of methods including scanning electron microscopy (SEM), cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS), have also drawn a lot of attention recently. We considered the effects of pH, buffer, scan rate, interference, and calibration curve. The susceptible electrode's linear calibration curve encompassed concentration values between 8.88 and 1000.0 µM. The calculated limits of detection and quantification were 32.12 and 107.0 µM, respectively. Furthermore, this method was established in real human urine samples and drug validation which have been shown satisfactory results for vitamin B6 detection.


Assuntos
Carbono , Cobre , Técnicas Eletroquímicas , Eletrodos , Vitamina B 6 , Carbono/química , Humanos , Técnicas Eletroquímicas/métodos , Vitamina B 6/análise , Vitamina B 6/urina , Cobre/análise , Cobre/urina , Piridoxina/análise , Piridoxina/urina , Nanopartículas Metálicas/química , Concentração de Íons de Hidrogênio , Limite de Detecção , Espectroscopia Dielétrica/métodos
2.
Acta Pharm ; 74(3): 479-493, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-39279529

RESUMO

The formulation of biopharmaceutical drugs is designed to eliminate chemical instabilities, increase conformational and colloidal stability of proteins, and optimize interfacial stability. Among the various excipients involved, buffer composition plays a pivotal role. However, conventional buffers like histidine and phosphate buffers may not always be the optimal choice for all monoclonal antibodies (mAbs). In this study, we investigated the effects of several alternative buffer systems on seven different mAbs, exploring various combinations of ionic strengths, concentrations of the main buffer component, mAb concentrations, and stress conditions. Protein stability was assessed by analyzing soluble aggregate formation through size exclusion chromatography. At low protein concentrations, protein instability after temperature stress was exclusively observed in the bis-TRIS/ glucuronate buffer. Conversely, freeze-thaw stress led to a significant increase in aggregate formation in tested formulations, highlighting the efficacy of several alternative buffers, particularly arginine/ citrate, in preserving protein stability. Under temperature stress, the introduction of arginine to histidine buffer systems provided additional stabilization, while the addition of lysine resulted in protein destabilization. Similarly, the incorporation of arginine into histi-dine/HCl buffer further enhanced protein stability during freeze--thaw cycles. At high protein concentrations, the histidine/citrate buffer emerged as one of the most optimal choices for addressing temperature and light-induced stress. The efficacy of histidine buffers in combating light stress might be attributed to the light-absorbing properties of histidine molecules. Our findings demonstrate that the development of biopharmaceutical formulations should not be confined to conventional buffer systems, as numerous alternative options exhibit comparable or even superior performance.


Assuntos
Anticorpos Monoclonais , Excipientes , Estabilidade Proteica , Soluções Tampão , Anticorpos Monoclonais/química , Excipientes/química , Concentração Osmolar , Composição de Medicamentos/métodos , Temperatura , Estabilidade de Medicamentos , Histidina/química , Congelamento , Química Farmacêutica/métodos , Arginina/química , Agregados Proteicos
3.
Cureus ; 16(8): e67423, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39310474

RESUMO

Background Efficient management of hospital inventories, particularly pharmaceuticals, is essential for ensuring timely patient care and optimizing resource allocation. Buffer stock is the backup stock, which is kept for providing a supply of drugs when the main stock is consumed and new stock is in the process of procurement. The buffer stock is sometimes kept in excess, which causes unnecessary overutilization of the financial resources. Therefore, the author's team aimed to optimize the inventory control of the buffer stock. This study addressed these challenges by integrating always better control (ABC) and vital, essential, and desirable (VED) analysis to categorize drugs based on consumption patterns and clinical importance to minimize buffer stock and ensure optimum resource allocation. To overcome these challenges, there is a need to integrate financial and clinical factors into inventory management decisions. Methods This study was done at the pharmacy of an apex hospital situated in a rural region of western India. The study aimed at the categorization of drugs that require strict inventory management control. The drugs and consumables used in the month of April 2024 in the hospital pharmacy were considered for the study & inventory control methods were applied.  Results The study discovered that a subgroup of drugs accounted for a significant portion of the pharmacy's budget, with 12.18% categorized as high-value (Category A), 22.07% as moderate-value (Category B), and 65.74% as low-value (Category C) items. ABC analysis showed that Category A drugs consumed 70.1% of the average daily expenditure (ADE) of the pharmacy, while Category B and Category C drugs contributed 19.9% and 9.98% of the ADE, respectively. VED analysis classified drugs into vital (11.34%), essential (58.26%), and desirable (30.39%) categories. The ABC-VED matrix further categorized drugs into subgroups, with class I items constituting 20.62% of the inventory and accounting for 73.82% of the ADE. Class II items comprised 56.69% of the inventory, consuming 22.91% of the ADE, while class III items constituted 22.68% of the inventory and consumed 3.28% of the ADE. Conclusion ABC and VED analysis integration provides a comprehensive framework for optimizing drug inventory management in healthcare facilities. By considering both financial and clinical factors, this approach enables tailored management strategies, minimizing buffer stock, eliminating stockouts, and enhancing patient care. The rural hospital's location is responsible for maintaining the buffer stock level and the reorder level quantity. This study highlighted the role of inventory control techniques in healthcare facilities, particularly in pharmacies, to ensure the availability of essential medications while optimizing resource utilization. By integrating segmentation techniques such as ABC and VED analysis, this study provided valuable insights into categorizing drugs based on their consumption patterns, criticality, and importance in the clinical area.

4.
Biotechnol Bioeng ; 2024 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-39295215

RESUMO

Polysorbates (PS) are commonly used as stabilizers of biopharmaceuticals such as monoclonal antibodies (mAbs). However, they are prone to chemical and enzymatic degradation. The latter can be caused by residual host cell proteins (HCPs) in the drug substance. Degradation affects the functionality of the PS surfactant which can lead to formation of particles. An increasing number of publications describe enzymatic PS degradation. Significant efforts have been made to characterize HCP removal during Downstream Processing (DSP) of mAbs and to develop mitigation strategies. Here we describe the use of glycine buffer for acidic elution in Protein A affinity chromatography compared to acetate buffer, which is more commonly used in the biopharmaceutical industry. Increased turbidity was observed during pH re-adjustment after low pH virus inactivation when using glycine buffer. Analytical data suggests that this turbidity is caused by the formation of precipitates which include HCP and DNA impurities. Additionally, as a zwitterion, glycine does not contribute to conductivity; this further enhances HCP removal during anion-exchange flow-through chromatography. Although glycine is well known as a possible elution buffer for Protein A affinity chromatography, its positive impact on HCP removal and PS stability have not yet been described in literature.

5.
Int J Mol Sci ; 25(17)2024 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-39273579

RESUMO

Proteins, saccharides, and low molecular organic compounds in the blood, urine, and saliva could potentially serve as biomarkers for diseases related to diet, lifestyle, and the use of illegal drugs. Lifestyle-related diseases (LSRDs) such as diabetes mellitus (DM), non-alcoholic steatohepatitis, cardiovascular disease, hypertension, kidney disease, and osteoporosis could develop into life-threatening conditions. Therefore, there is an urgent need to develop biomarkers for their early diagnosis. Advanced glycation end-products (AGEs) are associated with LSRDs and may induce/promote LSRDs. The presence of AGEs in body fluids could represent a biomarker of LSRDs. Urine samples could potentially be used for detecting AGEs, as urine collection is convenient and non-invasive. However, the detection and identification of AGE-modified proteins in the urine could be challenging, as their concentrations in the urine might be extremely low. To address this issue, we propose a new analytical approach. This strategy employs a method previously introduced by us, which combines slot blotting, our unique lysis buffer named Takata's lysis buffer, and a polyvinylidene difluoride membrane, in conjunction with electrospray ionization-mass spectrometry (ESI)/matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS). This novel strategy could be used to detect AGE-modified proteins, AGE-modified peptides, and free-type AGEs in urine samples.


Assuntos
Biomarcadores , Produtos Finais de Glicação Avançada , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Produtos Finais de Glicação Avançada/urina , Humanos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Biomarcadores/urina , Espectrometria de Massas por Ionização por Electrospray/métodos
6.
J Immunol Methods ; : 113762, 2024 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-39343085

RESUMO

BACKGROUND AIMS: Cord blood mononuclear cells (CBMCs) comprise a variety of single-nucleated cells found in the cord blood, mainly consisting of monocytes and lymphocytes. They also include a smaller proportion of other cell types, such as hematopoietic stem and progenitor cells (HSPCs) and mesenchymal stromal cells (MSCs). CBMCs are vital for acquiring hematopoietic stem and progenitor cells, MSCs, and other immune cells, like natural killer cells. These cells are essential for supporting subsequent research and clinical applications. Although automated equipment for CBMC enrichment has shown promise, the high cost of these machines and the expense of disposable consumables limit their routine use. Furthermore, limited information is available on manual strategies for isolating CBMCs from cryopreserved cord blood. Therefore, we aimed to optimize the dilution buffer and refine the isolation procedure for CBMCs. METHODS: We enhanced the CBMC recovery rate from cryopreserved cord blood using an optimized dilution buffer and a modified isolation procedure. RESULTS: We achieved average recovery rates of 42.4 % and 54.3 % for CBMCs and CD34+ cells, respectively. Notably, all reagents used in the isolation procedure were of GMP-grade or pharmaceutical preparations, underscoring the potential clinical benefits of our strategy. DISCUSSION: We devised an optimized protocol suitable for routine research and clinical applications for enhanced recovery of CBMCs from cryopreserved cord blood units using an optimized dilution buffer and a modified isolation procedure.

7.
Viruses ; 16(9)2024 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-39339831

RESUMO

High-consequence pathogens such as the Ebola, Marburg, and Lassa viruses are handled in maximum-containment biosafety level 4 (BSL-4) laboratories. Genetic material is often isolated from such viruses and subsequently removed from BSL-4 laboratories for a multitude of downstream analyses using readily accessible technologies and equipment available at lower-biosafety level laboratories. However, it is essential to ensure that these materials are free of viable viruses before removal from BSL-4 laboratories to guarantee sample safety. This study details the in-house procedure used for validating the inactivation of Ebola, Marburg, and Lassa virus cultures after incubation with AVL lysis buffer (Qiagen) and ethanol. This study's findings show that no viable virus was detectable when high-titer cultures of Ebola, Marburg, and Lassa viruses were incubated with AVL lysis buffer for 10 min, followed by an equal volume of 95% ethanol for 3 min, using a method with a sensitivity of ≤0.8 log10 TCID50 as the limit of detection.


Assuntos
Ebolavirus , Etanol , Vírus Lassa , Marburgvirus , Inativação de Vírus , Vírus Lassa/efeitos dos fármacos , Marburgvirus/efeitos dos fármacos , Ebolavirus/efeitos dos fármacos , Ebolavirus/fisiologia , Etanol/farmacologia , Inativação de Vírus/efeitos dos fármacos , Animais , Humanos , Contenção de Riscos Biológicos/métodos , Febre Lassa/virologia , Cultura de Vírus/métodos , Chlorocebus aethiops , Células Vero
8.
Small ; : e2406635, 2024 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-39340283

RESUMO

Aqueous zinc ion batteries (AZIBs) stand out from the crowd of energy storage equipment for their superior energy density, enhanced safety features, and affordability. However, the notorious side reaction in the zinc anode and the dissolution of the cathode materials led to poor cycling stability has hindered their further development. Herein, ammonium salicylate (AS) is a bidirectional electrolyte additive to promote prolonged stable cycles in AZIBs. NH4 + and C6H4OHCOO- collaboratively stabilize the pH at the interface of the electrolyte/electrode and guide the homogeneous deposition of Zn2+ at the zinc anode. The higher adsorption energy of NH4 + compared to H2O on the Zn (002) crystal plane mitigates the side reactions on the anode surface. Moreover, NH4 + is similarly adsorbed on the cathode surface, maintaining the stability of the electrode. C6H4OHCOO- and Zn2+ are co-intercalation/deintercalation during the cycling process, contributing to the higher electrochemical performance of the full cell. As a result, with the presence of AS additive, the Zn//Zn symmetric cells achieved 700 h of highly reversible cycling at 5 mA cm-2. In addition, the assembled NH4V4O10(NVO)//Zn coin and pouch batteries achieved higher capacity and higher cycle lifetime, demonstrating the practicality of the AS electrolyte additive.

9.
Vet Sci ; 11(9)2024 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-39330774

RESUMO

Subacute ruminal acidosis (SARA) is a prevalent metabolic disorder in highly productive dairy cows that results in serious issues, including hoof lamellar injuries. This study aimed to investigate the efficacy of a carbonate buffer mixture (CBM) in preventing hoof lamella injury in dairy goats, a species also susceptible to SARA due to similar feeding practices over a 17-week period. Twenty-four healthy dairy goats were randomly assigned to three groups: control, SARA, and CBM groups. The control group received a standardized diet, whereas the SARA and CBM groups were subjected to a high-grain feeding regimen to induce SARA. The CBM group received a daily supplement of 10 g CBM mixed with their diet. Clinical assessments, including body temperature, rumen pH, inflammatory markers, matrix metalloproteinases (MMPs), and hoof lamellar injuries, were monitored throughout the study. The results showed that the CBM group maintained a more stable rumen pH and had lower levels of inflammatory markers than the SARA group did. The incidence of hoof lamellar injury was slightly lower in the CBM group. These findings suggest that long-term CBM supplementation may mitigate SARA-associated hoof lamella injury in dairy goats by regulating the rumen environment, fostering the growth of healthy bacterial communities, and by reducing the production of harmful metabolites. The use of CBM as a dietary supplement may have significant implications in improving the health, welfare, and productivity of dairy animals.

10.
BMC Biotechnol ; 24(1): 63, 2024 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-39313794

RESUMO

BACKGROUND: Vibrio natriegens, a halophilic marine γ-proteobacterium, holds immense biotechnological potential due to its remarkably short generation time of under ten minutes. However, the highest growth rates have been primarily observed on complex media, which often suffer from batch-to-batch variability affecting process stability and performance. Consistent bioprocesses necessitate the use of chemically defined media, which are usually optimized for fermenters with pH and dissolved oxygen tension (DOT) regulation, both of which are not applied during early-stage cultivations in shake flasks or microtiter plates. Existing studies on V. natriegens' growth on mineral media report partially conflicting results, and a comprehensive study examining the combined effects of pH buffering, sodium concentration, and medium osmolality is lacking. RESULTS: This study evaluates the influence of sodium concentration, pH buffering, and medium osmolality on the growth of V. natriegens under unregulated small-scale conditions. The maximum growth rate, time of glucose depletion, as well as the onset of stationary phase were observed through online-monitoring the oxygen transfer rate. The results revealed optimal growth conditions at an initial pH of 8.0 with a minimum of 300 mM MOPS buffer for media containing 20 g/L glucose or 180 mM MOPS for media with 10 g/L glucose. Optimal sodium chloride supplementation was found to be between 7.5 and 15 g/L, lower than previously reported ranges. This is advantageous for reducing industrial corrosion issues. Additionally, an osmolality range of 1 to 1.6 Osmol/kg was determined to be optimal for growth. Under these optimized conditions, V. natriegens achieved a growth rate of 1.97 ± 0.13 1/h over a period of 1 h at 37 °C, the highest reported rate for this organism on a mineral medium. CONCLUSION: This study provides guidelines for cultivating V. natriegens in early-stage laboratory settings without pH and DOT regulation. The findings suggest a lower optimal sodium chloride range than previously reported and establish an osmolality window for optimal growth, thereby advancing the understanding of V. natriegens' physiology. In addition, this study offers a foundation for future research into the effects of different ions and carbon sources on V. natriegens.


Assuntos
Técnicas de Cultura Celular por Lotes , Meios de Cultura , Vibrio , Concentração de Íons de Hidrogênio , Concentração Osmolar , Vibrio/crescimento & desenvolvimento , Vibrio/efeitos dos fármacos , Meios de Cultura/química , Técnicas de Cultura Celular por Lotes/métodos , Sódio/metabolismo , Sódio/farmacologia , Oxigênio/metabolismo , Reatores Biológicos
11.
Heliyon ; 10(17): e37221, 2024 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-39319125

RESUMO

Alveolar macrophages (AMs) are a fully differentiated lung-resident immune cell population and are a critical component of lung immunity. AMs can be easily isolated from mice via bronchoalveolar lavage fluid (BALF) collection. The quality and quantity of AMs in BALF isolation are critical for generating reliable and high-quality data for ex vivo studies. Traditional techniques use ice-cold (4°C) buffer to collect AMs in BALF and result in low yield. Hence, a new method that consistently gives a higher yield of AMs is needed. We demonstrate here an optimized method that significantly increases the quantity of AM recovery in BALF (>2.8 times than the traditional method). Our method uses a warm-buffer (37°C) containing EDTA. We compared the viability and functional parameters (cytokine/chemokine expression, phagocytosis) of AMs isolated by our new and traditional methods. Our study revealed that AMs collected using our method have similar viability and functional characteristics to those collected using traditional method. Hence, our new method can be used for the collection of a higher number of AMs without altering their function. This protocol might also be useful for isolating tissue-resident immune cells from other anatomical sites for ex vivo and other downstream applications.

12.
Talanta ; 281: 126824, 2024 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-39250868

RESUMO

In native mass spectrometry (MS) salts are indispensable for preserving the native structures of biomolecules, but detrimental to mass sensitivity, resolution, and accuracy. Such a conflict makes desalting in native MS more challenging, distinctive, and sample-dependent than in peptide-centric MS. This review first briefly introduces the charged residue mechanism whereby native-like gaseous protein ions are released from electrospray droplets, revealing a higher degree of salt adduction than denatured proteins. Subsequently, this review summarizes and explores the existing strategies, underlying mechanisms and future perspectives of desalting in native MS. These strategies mainly focus on buffer exchange into volatile salts (offline and online approaches), addition of solution additives (e.g., anion, supercharging reagent, solution phase chelator and amino acid), use of submicron electrospray emitters (down to 60 nm), and other potential approaches (e.g., induced and electrophoretic nanoelectrospray ionization). The strategies of online buffer exchange and using nanoscale electrospray emitters are highlighted. This review would not only be a valuable addition to the field of sample preparation in MS, but would also serve as a beginner's guide to desalting in native MS.

13.
J Pharm Bioallied Sci ; 16(Suppl 3): S2353-S2355, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39346216

RESUMO

Introduction: Orthodontic treatment can alter the oral environment, leading to plaque accumulation and changes in microbial colonization. This study aimed to assess microbiological changes in 10 to 16-year-old children undergoing fixed orthodontic treatment. Methodology: The study included children aged 10-16 years, with one group wearing fixed orthodontic appliances and a control group without brackets. Data on salivary pH, buffer capacity, Streptococcus mutans, and Lactobacillus spp were collected at baseline and after 6 months. Logistic regression models evaluated associations between orthodontic treatment and elevated bacterial levels, adjusting for age, gender, pH, and buffer capacity. Results: Wearing fixed orthodontic appliances was significantly associated with elevated Streptococcus mutans (aOR: 6.62, 95% CI: 1.91-21.88) and Lactobacillus spp (aOR: 9.49, 95% CI: 2.57-35.07). Gender showed a significant association with Lactobacillus spp levels (aOR: 0.28, 95% CI: 0.09-0.87). Conclusion: Fixed orthodontic appliances significantly impact oral microbial changes, underscoring the need for proper oral hygiene during orthodontic treatment to reduce dental caries risk.

14.
Front Bioeng Biotechnol ; 12: 1452796, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39267904

RESUMO

Currently, Gramicidin S (GR-S) is produced enzymatically with the drawback of the presence of trifluoroacetic acid (TFA) or produced by fermentation involving several separation and purification steps. Therefore, this study is focused on the use of green solvents as unique extraction step to produce Gramicidin S from microbial biomass of Aneurinibacillus aneurinilyticus. Among the tested solvents, such as ethanol, acidic ethanol or buffer phosphate, the most favorable was acidic ethanol, extracting 96% of Gramicidin S from cells with a purity of 90%. Using acidic ethanol, extraction time within the range of 30-120 min exhibited minimal impact on Gramicidin S yield, whereas the biomass-to-extractant ratio emerged as a critical parameter. Gramicidin S extracts were characterized using Fourier Transform Infrared Spectroscopy (FTIR), Matrix Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF-MS), and Electrospray Ionization Mass Spectrometry (ESI-MS) coupled with Ultra Performance Liquid Chromatography (UPLC) and compared with commercial Gramicidin S.

15.
J Microencapsul ; : 1-12, 2024 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-39268923

RESUMO

AIM: To investigate the conformational changes in human serum albumin (HSA) caused by chemical (CD) and thermal denaturation (TD) at pH 7.4 and 9.9, crucial for designing controlled drug delivery systems with paclitaxel (PTX). METHODS: Experimental and computational methods, including differential scanning calorimetry (DSC), UV-Vis and intrinsic fluorescence spectroscopy, mean diameter, polydispersity index (PDI), ζ-potential, encapsulation efficiency (EE), in vitro release and protein docking studies were conducted to study the HSA denaturation and nanoparticles (NPs) preparation. RESULTS: TD at pH 7.4 produced smaller NPs (287.1 ± 12.9 nm) than CD at pH 7.4 with NPs (584.2 ± 47.7 nm). TD at pH 9.9 exhibited high EE (97.3 ± 0.2%w/w) with rapid PTX release (50% within 1h), whereas at pH 7.4 (96.4 ± 2.1%w/w), release only 40%. ζ-potentials were around -30 mV. CONCLUSION: Buffer type and pH significantly influence NP properties. TD in PBS at pH 7.4, provided optimal conditions for a stable and efficient drug delivery system.

16.
J Immunol Methods ; 533: 113742, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39153729

RESUMO

Stability of conjugated critical reagents supporting ligand binding assays to enable biotherapeutic drug development is a universal concern. Formulation buffer employed for long-term cold storage may be key to mitigate protein aggregation issues. We investigated biophysical and functional attributes of murine mAb and human multispecific drug labeled with biotin, ruthenium, and Alexa fluor 647 frozen at -80 °C in PBS or a protein storage buffer for 3-15 months. Aggregation was observed at 4 months in mAb A-Ru (11.2%) and -Alexa (10%) in PBS followed by precipitation and reduced biological binding at 15 months. Increased aggregation in drug Ru (11.7%, 6 months) and Alexa (6.9%, 15 months) were noted but without impact on performance. There were no observations with biotin labeled reagents.


Assuntos
Anticorpos Monoclonais , Soluções Tampão , Humanos , Animais , Anticorpos Monoclonais/química , Camundongos , Biotina/química , Estabilidade de Medicamentos , Agregados Proteicos , Rutênio/química , Estabilidade Proteica
17.
Sci Total Environ ; 951: 175437, 2024 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-39134268

RESUMO

Natural disaster can disrupt soil structure and replace established vegetation with younger plants, altering the local hydrological processes. We used hydrogen and oxygen stable isotopes to examine soil water dynamics and plant water uptake patterns in two adjacent fir stands in the eastern Qinghai-Tibet Plateau: a primeval mature stand (MF, finer- textured soil) and a debris flow-developed half-mature stand (HMF, coarser-textured soil). Our results showed that the isotopic composition and soil gravimetric water content (SWC) in deep soil water in MF exhibited a more pronounced hysteresis pattern in response to precipitation compared to HMF, indicating lower turnover rate of soil water in MF. This was also confirmed by a smaller contribution of preferential flow to deep soil water in MF compared to HMF. The higher water storage (higher SWC values) and lower turnover rate of soil water suggest a higher soil water buffer capacity in MF. Additionally, both stands showed no significant difference in plant water sources, but plants in MF used more winter precipitation due to the lower soil water turnover rate. These differences suggest MF may be more vulnerable to water disasters, while HMF may be more susceptible to seasonal droughts under climate change. Our insights enhance understanding of hydrological processes linked to changing surface conditions and offer valuable information for managing forest water resources in mountainous regions.


Assuntos
Solo , Água , Tibet , Solo/química , Abies , Mudança Climática , Monitoramento Ambiental
18.
J Environ Manage ; 368: 122095, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39126839

RESUMO

In designing and implementing initiatives to conserve biodiversity and ensure the flow of ecosystem services, it is crucial to understand the perspectives of communities living near protected areas. Improving conservation efforts may depend on analyzing socio-ecological factors and their impact on Local Ecological Knowledge (LEK) and perceptions of ecosystem services. We employed participatory methodologies with 80 farmers from agrarian settlements adjacent to protected areas in the Cerrado biome, Brazil, we quantified LEK and assessed perceptions of ecosystem services using an adaptation of the Q-methodology. We collected data on thirteen socio-ecological variables, including age, gender, farm size, education, engagement with conservation initiatives, and interactions with protected areas and Legal Reserves. Using artificial intelligence in a Random Forest (RF) modelling approach, we identified the most influential variables on LEK and perceptions. Our findings demonstrate that engagement in nature conservation and restoration initiatives, along with the use of native areas (protected and managed areas) significantly influence LEK levels within the farmers' communities. Farmers with full participation, from conception to implementation and evaluation of the initiatives, had a significantly higher LEK level (28.5 ± 13.0) compared to farmers without participation in those initiatives (11.4 ± 5.9). Farmers who used the cerrado for leisure and education (28.2 ± 21.2) had significantly higher LEK levels compared to farmers who do not attend or use the cerrado areas (13.5 ± 8.9) and those using areas of native vegetation for cattle raising (12.8 ± 6.8). These results highlight that, in addition to farmers' participation in conservation and restoration initiatives, the sustainable use of natural areas is fundamental to strengthen their local knowledge of ecosystem functioning. Furthermore, we found that the type of agroecosystem present on farms strongly? shapes farmers' perceptions of ecosystem services. Farmers perceive different ecosystem services depending on land use, indicating the need for tailored interventions for the planning and management of conservation areas. Farmers practicing soybean monoculture had significantly lower perception scores on ecosystem services (-5.1 ± 3.8) than to the other four evaluated groups. Overall, the study highlights the critical role of incorporating local knowledge and perceptions for the design of effective management strategies to increase ecosystem services provision and biodiversity conservation in areas adjacent to protected areas.


Assuntos
Biodiversidade , Conservação dos Recursos Naturais , Ecossistema , Brasil , Fazendeiros/psicologia , Humanos , Conhecimento , Ecologia , Percepção , Agricultura
19.
J Environ Manage ; 368: 121992, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39137634

RESUMO

Sustaining the development of rural and pastoral communities' hinges on livelihood resilience. Pastoralist household resilience relies on resource availability and decision-making abilities. Despite extensive studies on pastoralist livelihoods, a significant knowledge gap remains in understanding the nuanced adaptive capacities of diverse households, particularly amid grassland degradation. Thus, this study investigates the household-based livelihood resilience of pastoralists in China's Three-River Headwater Region, offering policy recommendations for resilient livelihoods. Using stratified random sampling, 758 pastoralist household heads underwent semi-structured interviews to collect data. Five household characteristics, encompassing age, gender, energy use, well-being perception, and multi-household grazing participation, were evaluated. Looking ot the nature of data, descriptive statistics and non-parametric tests were performed in this study to draw the valid inferences. The results revealed a positive correlation (p < 0.05) between household head age and livelihood resilience, with divergent resilience across age groups. Varied energy usage yielded distinct impacts; households employing solar or mixed energy sources exhibited heightened resilience (p < 0.05). Household well-being emerged as an invariant variable concerning resilience. Furthermore, engagement in multi-household grazing (an informal institution) significantly (p < 0.05) influenced pastoralist livelihood resilience. These insights advocate targeted support for young household heads and the adoption of clean energy. Exploring the deeper strategies and mechanisms of multi-household grazing can enhance understanding and policy integration, guiding eco-friendly progress within rustic landscapes for pastoral communities.


Assuntos
Ecossistema , Pradaria , China , Humanos , Características da Família , Conservação dos Recursos Naturais
20.
Nano Lett ; 24(35): 10899-10907, 2024 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-39186254

RESUMO

The oxygen evolution reaction (OER) performance of ruthenium-based oxides strongly correlates with the electronic structures of Ru. However, the widely adopted monometal doping method unidirectionally regulates only the electronic structures, often failing to balance the activity and stability. Here, we propose an "elastic electron transfer" strategy to achieve bidirectional optimization of the electronic structures of Sr, Cr codoped RuO2 catalysts for acidic OER. The introduction of electron-withdrawing Sr intrinsically activates the Ru sites by increasing the oxidation state of Ru. Simultaneously, Cr acts as an electron buffer, donating electrons to Ru in the presence of Sr in the as-prepared catalysts and absorbing excess electrons from Sr leaching during the OER. Such a bidirectional regulation feature of Cr prevents overoxidation of Ru and maintains its high oxidation state during the OER. The optimal Ru3Cr1Sr0.175 catalyst exhibits a low overpotential (214 mV @ 10 mA cm-2) and excellent stability (over 300 h).

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...