Relevant Products Research Articles

Exploring the intersection of sustainable design and cultural heritage: Enhancing community enterprise through product innovation in bamboo basketry using post-harvest sugar cane leaves

This research explores the dynamic intersection of sustainable design, cultural heritage, and community enterprise, focusing on the innovative utilization of post-harvest sugar cane leaves in bamboo basketry production from various provinces in Thailand. This study aims to investigate how design anthropology principles can enhance community enterprises’ resilience and sustainability by employing a qualitative case study approach. Findings reveal that while traditional bamboo basketry reflects the region’s rich cultural heritage, a shift towards sustainable practices offers environmental benefits and economic opportunities. Design anthropology informs the development of culturally relevant products, fostering market competitiveness and preserving traditional craftsmanship. Moreover, government policies play a pivotal role in supporting or hindering the growth of community enterprises, with soft power initiatives holding promise for promoting cultural heritage and sustainability. Collaboration between policymakers, design anthropologists, and local stakeholders is essential for developing inclusive policies that empower communities and foster sustainable development. Overall, integrating sustainable design practices and cultural insights holds significant potential for enhancing the resilience and effectiveness of community enterprises, ensuring a prosperous and sustainable future for both the industry and the communities it serves. This study is a testament that design anthropology provides a powerful framework for addressing complex social and environmental issues through the lenses of culture and design.

The impact of Digital literacy on ICT self-efficacy in Islamic secondary school teachers in District Kot addu South Pakistan

Digital literacy is the skill of using digital technologies in order to find, assess and produce relevant information and products. ICT self-efficacy refers to self-confidence in instructional use of Information and Communication Technology tools.This paper focuses on effects of Digital Literacy on ICT self-efficacy of teachers in Islamic secondary schools in District Kot Addu South Pakistan. Hence, probing into how digital literacy affects teacher’s self efficacy when using ICT in teaching becomes relevant given rising push on adoption of technology in learning. The results are expected to contribute to the body of knowledge regarding professional development needed to support appropriate incorporation of technology into teaching practices.It seeks to alert professional development providers on the potential of impacting teacher confidence and competence on using technological tools in instruction. This paper presents a qualitative investigation concerned with the effects of digital literacy on ICT self-efficacies of teachers in the Islamic secondary schools in District Kot Addu, South Pakistan. The research sought to establish the present level of use of, and confidence in use of, information communication technology among teachers; personal computer/Internet literacy skills; and correlation between these skills and attitude towards the use of ICT in teaching. In this study, data was collected through use of semi structured interviews and focus group discussions with fifteen teachers from five Islamic secondary schools. Finally, through analyzing themes identified in the cross-case analysis, it was shown that although most teachers adopted digital literacy and were comfortable with technological tools, they lacked adequate knowledge on how to incorporate digital technologies with higher complexity into their teaching practice. In addition, the study showed that the profile of digital literacy influenced ICT self efficacy, the need to address with immediacy and desire the continuing professional learning to improve on it. The study has therefore called for enhanced training that not only increases computer literacy skills but also the level of self-confidence in the use of ICT in teaching to enhance teaching practices in era of technology.The professional development programs should then focus on developing the skills that would increase ICT self efficacy among teachers so as to increase the level of self confidence in integration of technology in teaching and learning practices.

Structures and Biological Activities of Secondary Metabolites from Daldinia spp.

The genus Daldinia have long been recognized as a source of structural novel, pharmaceutically relevant natural products. We reviewed the structures and activities of secondary metabolites isolated from the genus of Daldinia from January 1995 to June 2024, and 280 compounds, including six major categories—terpenoids, alkaloids, polyketides, polyphenols, steroids, and other classes—are presented in this review. Among these metabolites, 196 were identified as new structures. Remarkably, 112 compounds exhibited a range of biological activities, including cytotoxic, antimicrobial, anti-inflammatory, antifungal, anti-virus, and enzyme-inhibitory activities. This review highlights the bioactive metabolites discovered in the past three decades from the genus of Daldinia while also exploring the potential of these symbiotic fungi as rich sources of novel and diverse natural products. The varying bioactivities of these metabolites offer a vast array of promising lead compounds and also could significantly contribute to the development of new medicines.

Rubber additives and relevant oxidation products in groundwater in a central China region: Levels, influencing factors and exposure

This study investigated the presence of rubber additives and relevant oxidation products (RAROPs) in groundwater in central China's aboveground river region. Seven RAROPs were detected, and their levels in shallow groundwater showed a mild decreasing trend from the area near the Yellow River (Avg: 8.49 ng·L-1) to the area on the far bank of the Yellow River (Avg: 5.01 ng·L-1). In contrast, deep groundwater's RAROPs contents showed a dramatic decrease to only 0.26 ng·L-1. The dominant contaminant was found to be N-(1, 3-dimethylbutyl) -N′-phenyl -p-phenylenediamine (6PPD). The vicinity of the garages and car parks was often characterized as contamination hotspots. Correlation analyses further indicated that aquaculture was likely to be a potential pathway for shallow groundwater contaminant inputs. The amount of RAROPs intake by humans through groundwater is nearly 30 times different due to the imbalanced development between urban and rural areas. Children were the most vulnerable to RAROPs. Therefore, human activities (transportation, waste tire storage, water resource allocation and utilization patterns, diversion of Yellow River water to aquaculture ponds) may exacerbate RAROPs pollution in groundwater by leaching contaminants through the surface soil. These results are important for developing appropriate utilization and protection strategies for groundwater resources in developing countries.

Mining Area Production Safety Optimization Based on Multi-objective Particle Swarm Optimization Model

Safe production in metal mines is an important task to ensure the safety of workers and the integrity of production equipment. From the perspective of optimization, this paper establishes an early warning model and a multi-objective particle swarm optimization algorithm model by analyzing the relevant production data affecting the indicator system of mine safety production, and then solves the model through the multi-objective particle swarm optimization algorithm to give an optimization scheme for maximizing the safety production of the relevant mines. For the safety production problems in metal mines, four indicator systems are proposed, namely, production ecological environment safety, production personnel safety standards, production equipment safety and production information security, and then the relevant production data of the four indicator systems are analyzed and the early warning model is established. Based on the relevant production data of the four indicator systems, the mathematical relationship between the production data affecting each indicator system is constructed. Then, a multi-objective particle swarm optimization algorithm is established to construct the relationship between the maximum safe production of the mine and each indicator system, and the index of the maximum safe production production data of the mine is obtained. The feasibility of the mine safety production optimization scheme is given.

Research on Sustainable Design of Smart Charging Pile Based on Machine Learning

With the rapid growth of the electric vehicle market, the importance of the user experience and product sustainability requirements for intelligent charging stations has become increasingly significant. However, accurately capturing the complex associations between design features and sustainability elements remains challenging. Therefore, this study aims to balance user needs and environmental standards in designing smart charging piles, ensuring adherence to symmetry principles. This balance addresses the growing demand for personalization and ensures sustainability. In this paper, the semiotic approach to product construction (SAPAD) model is introduced to analyze the user behavioral process in depth and clarify the core needs of users. Subsequently, these core needs are translated into specific technical requirements for products, and a correlation matrix linking user needs with product technical requirements is constructed using fuzzy quality function deployment (FQFD) to identify design features that fulfill the user requirements. The sustainability factors are then comprehensively evaluated and prioritized based on three dimensions: economic, environmental, and social, i.e., the triple bottom line (TBL). Furthermore, a mapping matrix is developed to connect the design features and sustainability factors, which is combined with the particle swarm optimization–random forest (PSO-RF) algorithm to predict the sustainability factors associated with design features that meet users’ needs. The number of branches m and the maximum depth d of the random forest (RF) algorithm are optimized using the particle swarm optimization (PSO) method. The results indicate that the SAPAD-FQFD model effectively identifies the user needs and relevant product design features. In contrast, the PSO-RF model adeptly manages the nonlinear relationships between charging pile design features and various sustainability factors, e.g., aesthetics and material selection, ensuring that the intelligent charging pile meets users’ core needs in terms of form and function, while embodying the principles of design symmetry. This integrated approach effectively bridges the gap between user needs analysis and product functional design, ensuring the sustainability of the design solution. This study contributes a sustainable framework for the development and design of smart charging piles and related products, further promoting the adoption of green design principles and symmetry design concepts within the supporting infrastructure of new energy vehicles.

Highs and Lows: A Mixed-Methods Analysis of the Impact of Adult Use Legalization on Medical Cannabis Patients

ABSTRACT Presently, 24 states have legalized adult use (recreational) cannabis, each following medical-only access. Although states that pass adult use laws report substantial declines in the number of registered medical patients, these laws expand the market, potentially enhancing patient benefits. However, research on federal adult use cannabis legislation in Canada suggests that adult use laws negatively impact medical patients. The purpose of this mixed-methods study was to examine medical cannabis patients’ perceptions of the impact of adult use cannabis laws in the US. We conducted an online survey with forced choice and open-ended questions in a convenience sample of 505 medical cannabis patients. Quantitative analysis indicated that adult use laws decreased stress and legal concerns, and that patient perceptions of cannabis product quality and availability were higher, but prices were also higher. Qualitative analysis largely aligned with quantitative findings, however data were somewhat divergent on price and product availability (with some patients reporting lower prices and accessibility issues). Mixed-methods analysis revealed that legalization also reduced patients’ experience of social stigma. Addressing the patient concerns revealed by these data may help to restore or maintain patient access to affordable, medically relevant cannabis products as additional states merge medical cannabis programs into adult use paradigms.

A dual-inducible control system for multistep biosynthetic pathways

BackgroundThe successful production of industrially relevant natural products hinges on two key factors: the cultivation of robust microbial chassis capable of synthesizing the desired compounds, and the availability of reliable genetic tools for expressing target genes. The development of versatile and portable genetic tools offers a streamlined pathway to efficiently produce a variety of compounds in well-established chassis organisms. The σ70lac and tet expression systems – adaptations of the widely used lac and tet regulatory systems developed in our laboratory – have shown effective regulation and robust expression of recombinant proteins in various Gram-negative bacteria. Understanding the strengths and limitations of these regulatory systems in controlling recombinant protein production is essential for progress in this area.ResultsTo assess their capacity for combinatorial control, both the σ70lac and tet expression systems were combined into a single plasmid and assessed for their performance in producing fluorescent reporters as well as the terpenoids lycopene and β-carotene. We thoroughly characterized the induction range, potential for synergistic effects, and metabolic costs of our dual σ70lac and tet expression system in the well-established microorganisms Escherichia coli, Pseudomonas putida, and Vibrio natriegens using combinations of fluorescent reporters. The dynamic range and basal transcriptional control of the σ70 expression systems were further improved through the incorporation of translational control mechanisms via toehold switches. This improvement was assessed using the highly sensitive luciferase reporter system. The improvement in control afforded by the integration of the toehold switches enabled the accumulation of a biosynthetic intermediate (lycopene) in the β-carotene synthesis pathway.ConclusionThis study presents the development and remaining challenges of a set of versatile genetic tools that are portable across well-established gammaproteobacterial chassis and capable of controlling the expression of multigene biosynthetic pathways. The enhanced σ70 expression systems, combined with toehold switches, facilitate the biosynthesis and study of enzymes, recombinant proteins, and natural products, thus providing a valuable resource for producing a variety of compounds in microbial cell factories.Graphical

Asymmetric Synthesis of Polycyclic Heterocyclic Compounds via Friedel-Crafts Reaction/Cyclization Reaction Catalyzed by Nickel Catalyst.

The first highly enantioselective asymmetric Friedel-Crafts reaction/cyclization reaction of 5-aminopyrazoles with 3-alkenyloxindoles to afford polycyclic heterocyclic compounds bearing an all-carbon quaternary stereocenter catalyzed by a complex of NiII with the C2-symmetric bipyridine-N,N'-dioxide ligand L12 has been developed. The relevant products with a wide range of substrates and good functional tolerance were obtained in 89-98% yield with 56-99% ee in the presence of 10 mol % Ni(OTf)2 and 11 mol % L12 in DCM at 25 °C. Moreover, an experiment on scaling up the process along with the transformations of the cycloadducts further emphasized the practical application of the synthesis.

What can a journal editorial team do to strive for equity in health professions education publishing? Leading by example

What was the Educational Challenge? Representation gaps in medical education publishing are widely recognized and may be attributed to epistemic injustice, defined as ‘wrong done to someone in their capacity as a knower.’ Although peer review is meant to ensure ‘rigor,’ some quality assurance practices can inadvertently silence entire populations and impede understanding of a field’s foundational concepts. What was the Proposed Solution? To honor our journal’s commitment to equitable knowledge production, a diversity, equity, and inclusion working group at Teaching and Learning in Medicine (TLM) reimagined rigor to include striving for a ‘more equitable, diverse, and inclusive research system.’ How was the Proposed Solution Implemented? We implemented structural peer review reform at TLM by adapting Hogan et al.’s Dimensionality and R4P framework for health equity, prioritizing change in our communication with contributors. What Lessons Learned are Relevant to a Wider Audience? Since implementation, our journal has received feedback expressing appreciation for humanity and personal connection in our peer review, and we have observed increased publications from geographically marginalized authors. We believe our outcomes result from respecting marginalized authors’ authority to pursue their own interests, concerns, and successes with respect to knowledge production. What are the Next Steps? We believe our approach can be adopted by other peer-reviewed journals. We invite application and critique of our framework to advance community development in creating relevant, accessible, and equitable knowledge production for all people.

Genomic Comparisons Revealed the Key Genotypes of Streptomyces sp. CB03234-GS26 to Optimize Its Growth and Relevant Production of Tiancimycins.

Strain robustness and titer improvement are major challenges faced in the industrial development of natural products from Streptomyces. Tiancimycins (TNMs) produced by Streptomyces sp. CB03234 are promising anticancer payloads for antibody-drug conjugates, but further development is severely limited by the low titer of TNMs. Despite many efforts to generate various TNMs overproducers, the mechanisms underlying high TNMs production remain to be explored. Herein, genome resequencing and genomic comparisons of different TNMs overproducers were conducted to explore the unique genotypes in CB03234-GS26. Four target genes were selected for further bioinformatic analyses and genetic validations. The results indicated that the inactivation of histidine ammonia-lyase (HAL) showed the most significant effect by blocking the intracellular degradation of histidine to facilitate relevant enzymatic catalysis and thus improve the production of TNMs. Additionally, the potassium/proton antiporter (P/PA) was crucial for intracellular pH homeostasis, and its deficiency severely impaired the alkaline tolerance of the cells. Subsequent pan-genomic analysis suggested that HAL and P/PA are core enzymes that are highly conserved in Streptomyces. Therefore, HAL and P/PA represented novel targets to regulate secondary metabolism and enhance strain robustness and could become potential synthetic biological modules to facilitate development of natural products and strain improvement in Streptomyces.

Kinetics of galactooligosaccharides (GOS) production with two β-galactosidases: Metallic ion effect and mathematical model

Galactooligosaccharides (GOS) are functional carbohydrates produced from different lactose sources like cheese whey. They are relevant products in the dairy industry. However, its enzymatic production implies a challenge due to its inhibition by metallic ions presence. Enzymatic production of GOS from lactose using β-galactosidase from Kluyveromyces lactis and Aspergillus oryzae were studied in the presence of metallic ions (calcium, potassium, sodium, and magnesium). Also, a kinetic enzymatic model was proposed and correlated to explain the metallic ion effect in the GOS production. For both enzymes, stronger inhibition effects were observed when calcium was present, followed by potassium, sodium, and magnesium. Consequently, additional efforts must be made for the calcium remotion before the enzymatic reaction for industrial applications. Moreover, the second-order kinetic model proposed in this work describes the GOS production using both enzymes with metallic ions presence. It was stablished that for GOS production using β-gal from K. lactis and A. oryzae with various salts, calcium showed the strongest inhibition for both enzymes, followed by potassium and sodium. A second-order kinetic model accurately described GOS production, better reflecting hydrolysis inhibition than transgalactosylation inhibition

Synthetic Approaches for the Construction of Chiral Aziridines

Optically active aziridines represent a pivotal class of rigid three‐membered nitrogen‐heterocyclic compounds found in natural products, pharmaceuticals, agrochemicals, and functional motifs, which have demonstrated outstanding practicability as therapeutic molecular frameworks, versatile synthetic endpoints, and functional materials in both academic and industrial communities. Recent years have witnessed a broad spectrum of prominent breakthroughs in the field of chiral aziridines due to the aziridine‐based rigid and three‐dimensional pharmacophores, which have resulted in streamlining the drug discovery process. Over the past few decades, particular attention has been directed towards the strategically efficient, versatile, and practical assembly of optically active aziridines. These synthesis approaches have demonstrated great potential in the context of the construction of pharmaceutical molecules, biologically and pharmacologically relevant natural products, and functional materials. In this review, several synthetic strategies for the assembly of chiral aziridines are summarized, which could be divided into five categories; (1) Introduction; (2) Construction of optically active aziridines via reactions of olefines with nitrene sources; (3) Construction of optically active aziridines via reactions of imines with carbenes; (4) Construction of optically active aziridines via reaction of azirines; (5) Construction of optically active aziridines via intramolecular cyclization of amine derivatives.

LitChemPlast: An Open Database of Chemicals Measured in Plastics.

Plastics contain various chemical substances, which can impact human and ecosystem health and the transition to a circular economy. Meanwhile, information on the presence of individual substances in plastics is generally not made publicly available, but relies on extensive analytical efforts. Here, we review measurement studies of chemicals in plastics and compile them into a new LitChemPlast database. Over 3500 substances, stemming from all plastic life-cycle stages, have been detected in different plastics in 372 studies. Approximately 75% of them have only been detected in nontargeted workflows, while targeted analyses have focused on limited well-known substances, particularly metal(loid)s, brominated flame retardants, and ortho-phthalates. Some product categories have rarely been studied despite economic importance, e.g., consumer and industrial packaging (other than food packaging), building and construction, and automotive plastics. Likewise, limited studies have investigated recycled plastics, while existing measurements of recycled plastics show higher detection frequencies and median concentrations of regulated brominated flame retardants across many product categories. The LitChemPlast database may be further developed or utilized, e.g., for exposure assessment or substance flow analysis. Nonetheless, the plethora of relevant substances and products underscores the necessity for additional measures to enable the transition to a safe circular plastics economy.

Higher Precision Is Not Always Better: Search Algorithm and Consumer Engagement

On decentralized e-commerce platforms, search algorithms play a critical role in matching buyers and sellers. A typical search algorithm routinely refines and improves its catalog of data to increase search precision, but the effects of a more precise search are little known. We evaluate such effects via a 2019 quasiexperiment on a world-leading e-commerce platform in which the search algorithm refined some product categories into finer subgroups to allocate consumer queries to more relevant product listings. Our data cover millions of consumers’ search and purchase behaviors over six months across multiple search sessions and product categories, enabling us to investigate trade-offs over time and across categories. We find that a more precise search algorithm improves consumers’ click-through and purchase rates drastically and instantaneously, but it comes at the cost of a significant decrease in consumer engagement and unplanned purchases over a longer time horizon. On average, consumers who used to spend more time searching now conduct 5.5% fewer searches, spend 4.1% less time on the platform, and decrease their spending on related categories by 2.2% in the week after the search precision increases. Our examination of the mechanisms behind these consequences calls for more careful search algorithm designs that account for not only instant conversion based on search precision but also consumer engagement and sellers’ strategic responses in the longer horizon. This paper was accepted by Anindya Ghose, information systems. Funding: This work was supported by the Key Program of the National Natural Science Foundation of China [Grants 72141305 and 72192803] and the Ministry of Education, People’s Republic of China (Fundamental Research Funds for the Central Universities), both to L. Fang. Supplemental Material: The online appendix and data files are available at https://doi.org/10.1287/mnsc.2023.00478 .

Environmental impact assessment in microalgal lipid production: carbon footprint and net emissions

This study focuses on analyzing the role of microalgae in mitigating climate change through CO2 capture and lipid production, which can be used in the development of energy products and commercially relevant products. The objective was to evaluate the net CO2 emissions in three lipid production scenarios from microalgae, in addition to analyzing the impact of various biomass pretreatment technologies before lipid extraction. For this purpose, only the emissions directly generated by energy consumption in the process and the amount of CO2 that can be captured by microalgae cultivation were considered. In all three scenarios, CO2 capture during biomass cultivation and emissions associated with maintaining the process in operation were evaluated. The results show that the emissions generated by energy consumption were 3.56 kg-CO2/kg-oil, 2.19 kg-CO2/kg-oil, and 2.36 kg-CO2/kg-oil in scenarios 1, 2, and 3, respectively, while the CO2 emissions captured in microalgae cultivation were three to four times higher, ultimately resulting in negative emissions in all scenarios. The efficiency of CO2 capture per kilogram of oil produced varies between scenarios, suggesting that the choice of technology and process conditions significantly influence the overall environmental impact. This analysis identifies areas of opportunity to improve microalgal biomass utilization processes, highlighting the stages of the process with the greatest impact on the carbon footprint and enabling the comparison of different technologies on the same basis.

Scaling of ultrashort-pulsed laser structuring processes for electromobility applications using a spatial light modulator

The structuring of lithium-ion battery (LIB) electrodes and the diffusion media (DM) for polymer electrolyte membrane fuel cells (PEMFCs) with ultrashort laser pulses enables improved performance characteristics of both technologies. However, the transfer of the approaches from a laboratory scale to a commercial use has previously been hindered by the low average output power of ultrashort-pulsed (USP) laser beam sources and the limited productivity of single-beam structuring using scanning optics. Recent advancements in the development of USP laser systems have led to a steady increase in the available output power, thereby enabling new fields of applications. This study aims at accelerating the USP laser structuring of LIB electrodes and DM for PEMFCs to industrially relevant processing rates by comparing a single-beam with a multibeam structuring process regarding ablation characteristics and quality. For the multibeam strategy, the shape of the laser beam was modified by a spatial light modulator (SLM). In addition to microholes, the insertion of microchannels was investigated to demonstrate the high flexibility of state-of-the-art SLMs. The geometry of the created structures was measured with a laser scanning microscope, and the different layers were tested for their geometrical and electrochemical properties to compare both technologies. The results confirmed that applying an SLM enables high-quality microstructures with significantly higher structuring rates. Furthermore, this contribution includes a theoretical analysis of the specifications required for a laser setup to reach an industrially relevant productivity of the structuring processes.

Analysis of tetrahydroisoquinolines formed after simultaneous consumption of ethanol and amphetamine or its derivatives by LC-MS/MS in human blood, brain, and liver tissue.

The effects of the simultaneous consumption of amphetamine or amphetamine derivatives and alcohol have not yet been adequately clarified, particularly concerning potential condensation products resulting from the endogenous reaction between these substances and their metabolites (e.g., acetaldehyde, a metabolite of ethanol). In this study, we developed an LC-MS/MS method employing liquid-liquid extraction for the qualitative detection of some relevant condensation products belonging to the class of tetrahydroisoquinolines and their derivatives in human blood, brain, and liver samples. This includes the analysis of the substrates amphetamine, methamphetamine, methylenedioxymethamphetamine, methylenedioxyamphetamine, as well as the condensation products 1,3-dimethyl-1,2,3,4-tetrahydroisoquinoline, N-methyl-1,3-dimethyl-1,2,3,4-tetrahydroisoquinoline, 1,3-dimethyl-7,8-methylenedioxy-1,2,3,4-tetrahydroisoquinoline, and N-methyl-1,3-dimethyl-7,8-methylenedioxy-1,2,3,4-tetrahydroisoquinoline. Therefore, the reference standards of the mentioned tetrahydroisoquinolines were synthesized in advance and the method was validated with regard to the question of the qualitative detection of these compounds. The validation parameters included selectivity, specificity, limit of detection, lower limit of quantification, recovery, matrix effects, and stability for blood, brain, and liver samples. Following the analysis of human blood and post-mortem tissue samples, evidence of the condensation product 1,3-dimethyl-1,2,3,4-tetrahydroisoquinoline originating from the interaction between amphetamine and acetaldehyde was identified in two liver samples. On the contrary, no evidence of this or other tetrahydroisoquinolines was found in the remaining tissue and serum samples.

Pancreatic Differentiation of Oral Minor Salivary Gland Stem Cells.

Stem cells from various sources including major salivary glands have been used to establish pancreatic differentiation in an attempt to provide new treatment options for patients with diabetes mellitus. In contrast, the potential of using the more easily accessible intraoral minor salivary glands has not been evaluated so far. Salivary stem cells were isolated from normal labial minor salivary glands that were removed during the excision of a mucocele and were attempted to differentiate into pancreatic cell lines using a culture medium enriched with activin A, retinoic acid and GLP-1.Real time RT-PCR was used to evaluate the expression of the genes of pancreatic transcription factors MafA, Ptf1a, Hb9 and Arx. Complementary, 22 labial minor salivary gland paraffin-embedded specimens were examined using immunohistochemistry for the presence of the relevant gene products of the pancreatic transcription factors Arx, MafA, Ptf1a and Pdx1. The differentiated salivary stem cells(cells of passage 3) expressed the genes of the pancreatic transcription factors MafA, Ptf1a, Hb9 and Arx even on the first day of the experiment while immunohistochemistry also confirmed the presence of the protein products of Arx, MafA, Ptf1a as well as Pdx1[> 50% of the specimens for Arx(5/8) and MafA(7/8), < 50% for Ptf1a(5/11) and Pdx1(5/11)] in ducts, mesenchymal connective tissue and acinar cells. Labial minor salivary glands may share gene and protein characteristics with pancreas suggesting a possible usefulness for pancreatic regeneration or substitution in cases of deficiency.

Study on Agglomeration and Plugging Behavior of Fine Particles in Reservoir Based on DEM-CFD Coupling

Abstract Given the particularity, significance, and complexity of particle migration behavior in fine silt sand hydrate reservoirs, the agglomeration and plugging behavior of free fine particles are mainly studied. Based on the discrete element method (DEM) and computational fluid dynamics (CFD), the DEM-CFD coupled 3D wellbore sand production numerical model is established and verified. The DEM module divides the reservoir particles into coarse and fine components according to the actual particle size distribution, and assigns adhesive and non-adhesive rolling resistance linear models, respectively. The CFD module uses the finite volume method to solve the incompressible Darcy flow in coarse grids. The results show that the DEM-CFD coupled numerical model established can effectively simulate the phenomenon of fine particle agglomeration during particle migration; Compared with the condition without particle agglomeration, fine particle agglomeration can lead to lower wellbore sand production and more severe pore blockage and permeability loss in the surrounding reservoir; The influences of different production and reservoir parameters such as flow rate, porosity and mud content on the variation of wellbore sand production and reservoir permeability under the condition of fine particle agglomeration is further determined, and relevant production measures and suggestions are put forward. The research results help to clarify the sand production mechanism and characteristics of fine silt sand reservoirs and are expected to provide theoretical and technical support for the efficient and safe development of natural gas hydrate resources in fine silt sand reservoirs.