Different Stages Of Maturation Research Articles

Innovations and smart technologies at Brazilian ports

Innovations can help ports become smarter and more effective and differentiate themselves from competitors. This study aims to explore the current state of innovations and smart technologies at Brazilian ports. The study sampled sixteen ports, representing 70% of port movements in Brazilian public ports in 2021. This is an exploratory and descriptive field study involving qualitative analysis. The results show that the surveyed ports are seeking strategies to innovate. Only one of the surveyed ports had a registered patent. Half of all ports had agreements with educational/research institutions, companies, or other ports for developing innovations. By contrast, no port engaged in technology transfer contracts with educational/research institutions, companies, or other ports. Few surveyed ports collaborated with HUBs, laboratories, or innovation centres. The three most widely used smart technologies at the surveyed ports were cloud computing, automated systems, and drone technologies. This study shows that Brazilian ports are undergoing a transformation process, but they find themselves in different stages of maturity regarding the appropriation and development of new technologies. New technologies are still incipient for some ports, while others have yet to adopt them. For example, only a few surveyed ports used smart technologies such as the Internet of Things, blockchain technology, or automated systems. Innovations and the inclusion of new technologies can generate benefits, but they require time and financial resources.

Effect of application rate of sodium nitrite and hexamine on the fermentation and the chemical composition of guinea grass silage harvested at different stages of maturity

Grass ensilability varies with maturity stage, mainly due to changing concentrations of dry matter and soluble carbohydrates with progressing forage maturity. Consequently, the required dose of silage additive to prevent the development of undesirable microorganisms may change with maturity stage. The objective of this study was to verify whether the application rate of an additive containing sodium nitrite and hexamine interacts with guinea grass maturity to alter silage fermentation and chemical composition. Four fields of guinea grass (0.5–0.7 ha each field) were mowed and divided into two plots per field. After 5 wk, one plot of each field was mowed again to establish differences in stage of maturity. Ten weeks after the first mowing, the grass plots with 5- and 10-wk regrowth were manually harvested and used for the trial. The grass from each plot (approx. 30 kg) was chopped and divided into 3 piles, totaling to 24 piles, as result of four fields, two maturities, and three additive treatments: control (without additive), low dose of sodium nitrite (0.5 g/kg) + hexamine (0.325 g/kg) (NHL), and high dose of sodium nitrite (1 g/kg) + hexamine (0.65 g/kg) (NHH). After 90 d of storage, the silos were opened and silages sampled to determine dry matter (DM) loss, microbial counts, fermentation end-products, aerobic stability, chemical composition, and in vitro DM digestibility. Guinea grass harvested at 10-wk regrowth had a lower content of crude protein (P < 0.001) and a greater content of cell wall components (P < 0.001), resulting in a more lignified (P < 0.001) and less digestible (P < 0.001) forage than that harvested at 5 wk. There were interactions between plant maturity and additive dose for several silage traits (P < 0.05), likely due to the slightly greater fermentability coefficient (+5.1 points) for the more mature grass (P < 0.001). Within each maturity stage, silage pH and fermentation end-products associated with clostridia metabolism (i.e., n-butyric acid, propionic acid, i-butyric acid, i-valeric acid, n-valeric acid, ammonia, and 2,3-butanediol) linearly decreased (P < 0.001) with additive application rate, but the magnitude of improvement was slightly greater for 5-wk than 10-wk regrowth. Application of additive linearly decreased silage DM loss at both 5-wk (95.2, 46.7, and 20.6 g/kg DM, P < 0.001) and 10-wk (66.5, 31.7, and 13.6 g/kg DM, P < 0.001) regrowth stages, but only silages treated with NHH had n-butyric acid concentration < 3 g/kg DM. The proportion of rumen undegradable protein (P < 0.001), soluble carbohydrates concentration (P < 0.001), and in vitro DM digestibility (P < 0.001) were linearly increased with additive dose within each maturity stage. As treated silages were better conserved, silage aerobic stability was linearly reduced (P < 0.001) with additive dose, although all silages were aerobically stable for ≥ 4.7 d. In conclusion, the additive based on sodium nitrite and hexamine, applied at a regular dose, was able to largely restrict Clostridium development and DM losses during fermentation of guinea grass silage at both maturity stages. However, harvesting more mature grass markedly impaired its chemical composition and digestibility, rendering it no feasible strategy to reduce the additive application rate by half.

Implementing Innovation: Informatics-Based Technologies to Improve Care Delivery and Clinical Research.

Improving technology has promised to improved health care delivery and the lives of patients. The realized benefits of technology, however, are delayed or less than anticipated. Three recent technology initiatives are reviewed: the Clinical Trials Rapid Activation Consortium (CTRAC), minimal Common Oncology Data Elements (mCODE), and electronic Patient-Reported Outcomes. Each initiative is at a different stage of maturity but promises to improve the delivery of cancer care. CTRAC is an ambitious initiative funded by the National Cancer Institute (NCI) to develop processes across multiple NCI-supported cancer centers to facilitate the development of centralized electronic health record (EHR) treatment plans. Facilitating interoperability of treatment regimens has the potential to improve sharing between centers and decrease the time to begin clinical trials. The mCODE initiative began in 2019 and is currently Standard for Trial Use version 2. This data standard provides an abstraction layer on top of EHR data and has been implemented across more than 60 organizations. Patient-reported outcomes have been shown to improve patient care in numerous studies. Best practices for how to leverage these in an oncology practice continue to evolve. These three examples show how innovative has diffused into practice and evolved cancer care delivery and highlight a movement toward patient-centered data and interoperability.

Changes in anthocyanins, total phenolics, total flavonoid, and antioxidant activity of Karanda fruit at different stages of maturity

Karanda (Carissa carandas L.) is mostly eaten raw and contains numerous phytochemicals and high antioxidant capacity. The objective of this study was to investigate the effects of the Karanda fruit’s developmental stages on its phytochemical contents, antioxidant capacity, and volatile compounds. The study herein examined three developmental stages; unripe, semi-ripe, and ripe, based on their stage of maturity as observed in their color and texture. Phytochemical properties; including pH, titratable acidity, vitamin C contents, total soluble solid, total phenolic contents, total flavonoid content, anthocyanin contents, and antioxidant capacity (determined through FRAP, DPPH, and ABTS) were measured. Our results found significant differences in the phytochemical properties in each stage of development. Ripe fruits had the highest pH, total soluble solid, anthocyanin content, and antioxidant capacity determined by FRAP. Thirteen volatile compounds were identified in the fruit samples: eight compounds within the unripe fruits, nine within the semi-ripe fruits, and seven compounds were present in the fully ripe fruits. Alanine ethyl amide and acetic acid were major volatile compounds found in unripe and semi-ripe fruits, whereas tartronic acid was present in the fully ripe fruit. We may conclude that the ripe stage of development, having the highest phytochemical contents and antioxidant activity, is most suitable for harvest and most beneficial for human health. The information obtained in this study will be useful for the efficient utilization of Karanda fruit

ATG9 vesicles comprise the seed membrane of mammalian autophagosomes.

As the autophagosome forms, its membrane surface area expands rapidly, while its volume is kept low. Protein-mediated transfer of lipids from another organelle to the autophagosome likely drives this expansion, but as these lipids are only introduced into the cytoplasmic-facing leaflet of the organelle, full membrane growth also requires lipid scramblase activity. ATG9 harbors scramblase activity and is essential to autophagosome formation; however, whether ATG9 is integrated into mammalian autophagosomes remains unclear. Here we show that in the absence of lipid transport, ATG9 vesicles are already competent to collect proteins found on mature autophagosomes, including LC3-II. Further, we use styrene-maleic acid lipid particles to reveal the nanoscale organization of protein on LC3-II membranes; ATG9 and LC3-II are each fully integrated into expanding autophagosomes. The ratios of these two proteins at different stages of maturation demonstrate that ATG9 proteins are not continuously integrated, but rather are present on the seed vesicles only and become diluted in the expanding autophagosome membrane.

Post-harvest conservation of mangosteen (Garcinia mangostana): Influence of fruit harvest stage and effectiveness of some practical conservation treatments

ABSTRACT Post-harvest losses caused by poor fruit storage can in some cases reach more than 80% of the crop. For the mangosteen crop, these losses are all the more important as they constitute a major problem. In Côte d’Ivoire, the few mangosteen preservation techniques have been developed mainly by traders and are based on limiting exchanges with the surrounding environment. However, these techniques are not very effective because they only preserve the fruit for a few days. In order to address this issue, the present study aims to evaluate the influence of the harvesting stage and the effectiveness of preservation treatments on the storage time and the evolution of several physical and biochemical parameters of the mangosteen. To this end, mangosteens harvested at two different stages of maturity were subjected to different preservation treatments (refrigeration, bagging, oil coating and blanching). The results showed that the storage time of the mangosteen was significantly longer with fruit harvested at the orange-red stage. Also, two of the four storage treatments evaluated, namely refrigeration and bagging, significantly extended the shelf life of the mangosteen (+15 and+6 days respectively with these treatments). In contrast to these treatments, blanching caused a reduction in fruit storage time.

Callovian source rock modelling as encountered in the Chotts Basin and the Gulf of Gabes: Generation and maturity distribution

The Callovian series are considered as proven to have sourced the reservoirs of the Ezzaouia and El Bibene fields of south-eastern Tunisia. However, its potential is still subject of debate associated with its paleogeographic distribution along with its burial and thermal histories. In this study, 17 wells drilled in the southern Chotts Basin and the Gulf of Gabes were used to model the burial and maturity histories of the Callovian series and estimate volumes of generated and expelled hydrocarbons.The Callovian organic material is generally marked by type II-III with low to moderate contents (up to 1%). The Callovian successions located in the north-eastern part of the Chotts Basin bear low total organic carbon (TOC) contents averaging 0.25%.TOC content and petroleum potential maps were generated with the Callovian series showing a source potential, southwards of the study area.Modelling results show variable burial and thermal histories depending on the location of selected wells. The series with source rock potential in wells located south of the Chotts Basin are in a an early to mid-mature stage with substantial amounts of generated oil. The Callovian series in the Gulf of Gabes are marked by advanced thermal maturity with gas generation being initiated since 10My. A maturity map is proposed for the Callovian series underlying four different stages of maturity.

Brazilians technology transfer offices: processes’ performance and effectiveness

Considering relations between universities and the productive sector, the Technology Transfer Offices (TTOs) fundamentally foster innovation. In the technology process, transfer TT) since they are responsible for studies of prospecting and competitive intelligence and their protection in intellectual property (IP). The present study aims to identify the effectiveness of TT processes as a measure of the performance of Brazilians Science and Technology Institutions (STIs) TTOs considering their technology, innovation promotion policies and intellectual property protection. It regards qualitative, exploratory-descriptive research with a multiple-study method. The data was collected through documentary research and semi-structured interviews with three groups of actors already participating in TT processes: researchers, TTO managers, and company managers. Through the triangulation of data, data triangulation these institutions still need to have adequate adherence to the models of business innovation management used by the local productive sector and need more bidirectional planning. Despite the advancement of the scope and quality of services offered by TTOs and the amounts of technology contracts, there has been an extensive effort to improve the communication channels and promote innovation by identifying factors that contribute to and hamper the promotion of change in the Ceará' scenario, the characteristics that group STIs in different stages of maturation were detected.

Zika virus-induces metabolic alterations in fetal neuronal progenitors that could influence in neurodevelopment during early pregnancy.

Cortical development consists of an orchestrated process in which progenitor cells exhibit distinct fate restrictions regulated by time-dependent activation of energetic pathways. Thus, the hijacking of cellular metabolism by Zika virus (ZIKV) to support its replication may contribute to damage in the developing fetal brain. Here, we showed that ZIKV replicates differently in two glycolytically distinct pools of cortical progenitors derived from human induced pluripotent stem cells (hiPSCs), which resemble the metabolic patterns of quiescence (early hi-NPCs) and immature brain cells (late hi-NPCs) in the forebrain. This differential replication alters the transcription of metabolic genes in both pools of cortical progenitors but solely upregulates the glycolytic capacity of early hi-NPCs. Analysis using Imagestream® revealed that, during early stages of ZIKV replication, in early hi-NPCs there is an increase in lipid droplet abundance and size. This stage of ZIKV replication significantly reduced the mitochondrial distribution in both early and late hi-NPCs. During later stages of ZIKV replication, late hi-NPCs show reduced mitochondrial size and abundance. The finding that there are alterations of cellular metabolism during ZIKV infection which are specific to pools of cortical progenitors at different stages of maturation may help to explain the differences in brain damage over each trimester.

Design teams and industry life cycles: The interplay of innovation and complexity

AbstractThis paper studies how innovation teams can be optimally configured to yield the best possible performance at different stages of a certain technology's life cycle, which correspond to different levels of environmental complexity. To conduct our analysis, we have employed computational simulations of communities searching NK landscapes at varying levels of complexity. We studied how the relative proportion of exploring agents to exploiting agents in a community impacts the evolution of scores over time, and conducted additional investigations into the role of specialization (i.e., the agents' propensity to take their preferred action) and density (i.e., the expected width of social groups within the community).We discover that majority‐explorer teams are to be preferred when complexity is high and over the long run, whereas majority‐exploiter teams are more effective in the short run and at low complexities. Furthermore, we show that higher levels of specialization yield better results at higher complexities, and that majority‐explorer teams benefit the most from higher levels of density. We conclude that different team compositions are to be preferred at different stages of maturity, and that selecting a time horizon for operations is of crucial importance when designing an innovation team.

Modal analysis of the coffee fruit-peduncle-branch system coffee fruit-peduncle-branch system

The mechanized harvesting of coffee fruits is performed by machines that uses the mechanical vibrations principles and has been widely adopted due the operational cost reductions compared to manual way. Maturation stages, frequency and amplitude of vibration influence the fruits detachment during the mechanized harvesting by mechanical vibrations. In this context, the determination of the modal parameters of the coffee plant is essential, considering, the full and selective harvesting. Modal analysis can be performed experimentally by using a specific instrumentation and, from this technique, it is possible to determine the vibration modes, damping factors and natural frequencies of the system in order to identify its dynamical behavior, supporting in the design and set-up of harvesting machines. In this way, this study was developed with the objective of determining and evaluating the modal characteristics of the coffee fruit-peduncle-branch system, such as the natural frequency, ratio and damping coefficient, from impact modal analysis. Additionally, the influence of the maturation stage, branch configurations (with/without leaves and fruits) and plant position in relation to the modal parameters of the system were evaluated. For branches without leaves and with fruits in different stages of maturation, several scenarios were studied. The results obtained verify that branches with ripe fruits (25.51 Hz, 24.19 Hz and 16.00 Hz for upper, middle and lower position in the plant, respectively) generally showed higher mean natural frequencies than branches with unripe fruits (16.77 Hz, 15.30 Hz and 15.49 Hz for upper, middle and lower position in the plant, respectively). For the complete branches with leaves and fruits, no significant differences in the first natural frequency were found between the mean natural frequencies throughout the plant and for different maturation stages. This pattern was repeated for the second and third natural frequencies, except for the difference in the average natural frequency found for branches with ripe fruits in the middle third of the plant. This behavior may be an important finding for the adjustment of harvesting machines since there was no differentiation between the average values of the natural frequency throughout the plant.

The Effects of Downhill Running and Maturation on Histological and Morphological Properties of Tendon and Enthesis in Mice.

To date, it remains unclear how overuse affects the tendons and entheses at different stages of maturation. Therefore, we evaluated histological and morphological changes in the tendons and entheses in adolescent (4-week-old) and adult mice (8-week-old) by performing flat-land and downhill running exercises. The mice were divided into the Sedentary, High Flat (flat-land high-speed running; concentric-contraction exercise), Low Down (downhill low-speed running; eccentric-contraction exercise), and High Down (downhill high-speed running; eccentric-contraction exercise) groups. Histological changes and inflammatory factor expressions were compared in the entheses and tendons after 4 weeks of exercise. Downhill, but not flat-land high-speed running, induced muscle-tendon complex hypertrophy in both adolescent and adult mice. Histological enthesis changes were induced in both groups during downhill running but were less pronounced in adult mice. Conversely, no significant cell aggregation or fiber orientation changes were observed in the tendon, but increased inflammatory factors were observed in both groups, with significantly higher expression in the tendons of adult mice. Downhill running induced histological and morphological enthesis changes and inflammatory factor increase in the tendons, regardless of running speed variations. These results may help elucidate the pathogenesis of enthesopathy and tendinopathy, which have different pathophysiologies despite having the same pathogenetic factors.

A Superstructure Mixed-Integer Nonlinear Programming Optimization for the Optimal Processing Pathway Selection of Sludge-to-Energy Technologies

The perception of sewage sludge has increasingly changed from being a waste, which is a burden to the environment and society, to a useful resource of materials and renewable energy. There are several available technologies at different stages of maturity that aim to convert sludge to energy in the form of electricity and/or fuels. In this paper, a decision-making support tool is proposed to help in choosing the optimal pathway for the sludge-to-energy conversion from a techno-economic perspective. The conversion technologies under study are: (1) anaerobic digestion, (2) pyrolysis, (3) gasification, (4) incineration, (5) supercritical water oxidation, (6) supercritical water gasification, as well as the corresponding dewatering and drying methods for each technology. Different synergies between the available technologies are compared by the formulation of a superstructure optimization problem expressed in a mixed-integer non-linear program (MINLP) model. The applicability of the proposed model is explored via a case study for a hypothetical sludge treatment plant with a capacity of 100 tons of dry solids (tDS) per day. The model is solved via the BARON solver using GAMS software within a reasonable processing time. According to the obtained results, the fast pyrolysis technology, coupled with filter press dewatering and thermal drying as pre-treatment steps, show the most promising outcomes with the minimum treatment cost of USD 180/tDS. Fast pyrolysis converts the sludge to bio-oil, which can be used as an alternative fuel after further refining, and biochar, which can be used for soil amendment or adsorption purposes. The model parameters are subject to uncertainty that is addressed in the sensitivity analysis section of this paper. Moreover, the pyrolysis pathway shows a high degree of robustness in most of the sensitivity analysis scenarios. Meanwhile, anaerobic digestion coupled with fast pyrolysis demonstrates the best energy recovery performance upon increasing electricity prices.

Understanding the compositional changes of organic matter in torrefied olive mill pomace compost using infrared spectroscopy and chemometrics

Composting olive mill pomace (OMP), the major by-product of the olive oil industry, is an attractive waste management practice in the context of sustainable food production. Thermal treatment of compost at mild temperatures (torrefaction) can aid to improve its characteristics as a soil amendment. This study aims to understand the chemical changes occurring during torrefaction of olive mill pomace-based (OMP) compost, as well as to evaluate the treatment effects on compost at different stages of maturation. Here, treatments at different temperatures (175, 225, and 275 °C) and duration (from 1 to 5 h) have been employed to obtain a sort of torrefied samples. In general, the H/C and O/C atomic ratios of compost samples decreased with torrefaction temperatures, which suggests an incipient coalification of the organic matter. Furthermore, the results showed that a combination of FT-NIR and FT-MIR spectroscopy using a low-level data fusion strategy is very sensitive to the molecular changes occurring both in the composting process and during heating. Principal Component Analysis (PCA) of the merged spectra revealed that the changes at 175 °C are mainly the loss of water (O–H contributions at 3300 and 5169 cm−1) together with the degradation of proteins (observed in the decrease of amide I and II characteristic bands). Furthermore, the samples heated at this temperature can still be differentiated by their initial maturation stage. On the other hand, thermochemical changes occurring at higher temperatures are more intense and make the samples more alike, independently of the composting time. When heating above 225 °C, the loss of O–H happens together with the decrease of aliphatic moieties, reflected in the bands 2920 and 2850 cm−1 (FT-MIR) and 4258, 4323, 5665, and 5781 cm−1 (FT-MIR). This can be attributed to the thermal degradation of cellulosic materials and, additionally, to the degradation of the residual oil in the case of poorly composted samples. Heated samples are characterized by the presence of carbonyl groups (1709 cm−1) and humic-like complex and polymerized aromatic structures (1579 cm−1). Since the characteristics of the torrefied compost at 275 °C are very similar regardless of the initial maturation stage, torrefaction may be a very interesting way to reduce the composting time of olive mill pomace to obtain a high-quality organic amendment for soil application.

Does maturity level influence the use of Agile UX methods by digital startups? Evaluating design thinking, lean startup, and lean user experience

Agile UX methods such as Design Thinking, Lean Startup, and Lean User Experience have been employed to deliver customer value and improve organizational performance. However, there is a lack of studies that assess how these tools are used at different stages of maturity of digital startups. The present study aims to compare the knowledge of graduated, incubated, and pre-incubated digital startups at university incubators concerning the use of Agile UX methods so that weaknesses and opportunities can be identified to provide co founders and scholars with new strategic insights. Six reduced focus groups were conducted with 14 members of the six selected startups via multiple case studies. Answers were registered by researchers and then analyzed using an inductive process and codification. The results indicated that digital startups had contact with consumers through market research, viability analysis, and product discontinuity. However, except for one startup, deficiencies in co-founders' participation throughout developing products and services projects were identified. As far as the multiple case studies are concerned, Design Thinking and Lean Startup were employed by four of the startups, while two of them used the Lean User Experience method due to its higher maturity level. Although all Agile UX methods were employed, all six digital startups reported having made adaptations to the methods or to have used them only partially. Finally, it was concluded that the maturity level influences the Agile UX methods of each digital startup according to its nature and its stage of development in the market.

Chemical Composition and Sensory Quality of Coffee Fruits at Different Stages of Maturity

The configuration of the sensory quality of coffee begins in the tree, where chemical precursors are deposited and formed in the seeds as the fruits develop. Fruit within the range classified as mature can have a wide range of properties. This study evaluated three degrees of maturity and established their chemical and sensory characteristics using analytical techniques such as liquid and gas chromatography. The maturity states evaluated did not show differences in organic acids, free fatty acids, lipids, total chlorogenic acids, proteins, alkaloids or sucrose. Fructose and glucose showed differences with respect to the degree of maturity, with higher values associated with more developed states. The analysis of variance did not show a significant effect on sensory attributes or sensory quality. The chromatic coordinate a* of the CIEL*a*b* scale reached a maximum value of 25.16, and the evaluated states were different from each other.

An aberrant presentation of non-hodgkin’s lymphoma as pus: A curious journey

T-lymphoblastic lymphoma (T-LBL) is most commonly found in younger age group and rare. It is most aggressive form ofnon-Hodgkin’s lymphoma. T-lymphoblastic lymphoma (T-LBL) response rate to chemotherapy is very good although relapse is common with poor survival rates.A 25 years old female presented to emergency department of a tertiary care centre with dyspnoea and chest tube in left Hemothorax in situ. She had earlier history of pulmonary tuberculosis 3 years back and took anti tubercular treatment for 6 months. On general examination we found left supraclavicular lymphadenopathy of size 2 × 1.5cm and grade 2 clubbing.The pleural fluid was sent for analysis. It was reported as exudative pleural effusion with low ADA and negative for malignant cells. Lymph node biopsy was sent for histopathological examination which was reported as T Lymphoblastic lymphoma. NHL is a diverse category of cancers that originate from B or T cells at different stages of maturation. In relation to our case; earlier history of tuberculosis, pus from lymph node could mislead to infective aetiology; as lymph node necrosis is commonly found in Hodgkin’s disease. This fact reiterates the fact that through clinical examination and history leads to proper diagnosis and management of the patient and can save time of the patients.

Programming Delayed Dissolution Into Sacrificial Bioinks For Dynamic Temporal Control of Architecture within 3D‐Bioprinted Constructs

AbstractSacrificial printing allows introduction of architectural cues within engineered tissue constructs. This strategy adopts the use of a 3D‐printed sacrificial ink that is embedded within a bulk hydrogel which is subsequently dissolved to leave open‐channels. However, current conventional sacrificial inks do not recapitulate the dynamic nature of tissue development, such as the temporal presentation of architectural cues matching cellular requirements during different stages of maturation. To address this limitation, a new class of sacrificial inks is developed that exhibits tailorable and programmable delayed dissolution profiles (1–17 days), by exploiting the unique ability of the ruthenium complex and sodium persulfate initiating system to crosslink native tyrosine groups present in non‐chemically modified gelatin. These novel sacrificial inks are also shown to be compatible with a range of biofabrication technologies, including extrusion‐based printing, digital‐light processing, and volumetric bioprinting. Further embedding these sacrificial templates within cell‐laden bulk hydrogels displays precise control over the spatial and temporal introduction of architectural features into cell‐laden hydrogel constructs. This approach demonstrates the unique capacity of delaying dissolution of sacrificial inks to modulate cell behavior, improving the deposition of mineralized matrix and capillary‐like network formation in osteogenic and vasculogenic culture, respectively.

Evaluation of extracellular polymeric substances matrix volume, surface roughness and bacterial adhesion property of oral biofilm

Background/purposeOral biofilms are highly structured bacterial colonies embedded in a highly hydrated extracellular polymeric substances (EPS) matrix. This study aimed to investigate the characteristics of oral biofilm at different stages of maturation. Materials and methodsOral multispecies biofilms were grown anaerobically from plaque bacteria on collagen coated hydroxyapatite discs in brain heart infusion broth for one and three weeks. The volume of live bacteria and EPS matrix of the biofilms were determined by using corresponding fluorescent probes and confocal laser scanning microscopy. Atomic force microscopy (AFM) was used to quantitatively probe and correlate cell surface adhesion force of biofilms. The surface roughness was quantified in terms of the root mean square average of the height deviations. Adhesion was measured from force–distance data for the retraction of the cell from the surface. ResultsThe volume of live bacteria and EPS of 3-week-old biofilms was higher than 1-week-old biofilms. The surface roughness value in 1-week-old biofilms was significantly higher than that in 3-week-old biofilms. AFM force–distance curve results showed that the adhesion force at the cell–cell interface was significantly more at-tractive than those at bacterial cells surface of both stages biofilms. Adhesion forces between the AFM tip and the surface of bacterial cell were fairly constant, whereas the cell–cell interface experienced greater adhesion forces in the biofilm's development. ConclusionAs oral biofilms become mature, EPS volume and cell–cell adhesion forces increase while the surface roughness decreases.

Variation in physicochemical properties and bioactivities of Morinda citrifolia L. (Noni) polysaccharides at different stages of maturity.

Morinda citrifolia L. (Noni) as an evergreen plant is a rich source of natural polysaccharides. The present work aims to investigate the maturation-related changes in polysaccharides of Morinda citrifolia L. (Noni) at five stages of maturity (stages from the lowest to highest degree - 1, 2, 3, 4, and 5). The chemical composition (carbohydrate, protein, uronic acid, and sulfate radical) of Noni polysaccharides was determined by different chemical assays. Ion chromatography system was used to analyze the monosaccharide composition, and the molecular weight was measured by HPGPC. The polysaccharides were also analyzed by FT-IR and their radical scavenging effect against DPPH, hydroxyl radicals and ABTS was evaluated. The UV-vis assay and gel electrophoresis assay were performed to investigate the DNA damage protective effect. Results indicated the significant effect of fruit maturities on the extraction yields, molecular weights, uronic acid contents, sugar levels, monosaccharide compositions and proportions, antioxidant capacities, and DNA protective effects of Noni polysaccharides. However, no fruit maturity stage had prominent impact on the sulfuric radical contents and preliminary structure characteristics. Noni polysaccharides extracted at stage 5 (N5) had the largest extraction yield (8.26 ± 0.14%), the highest sugar content (61.94 ± 1.86%) and the most potent scavenging effect on DPPH (IC50: 1.06 mg/mL) and ABTS (IC50: 1.22 mg/mL) radicals. The stronger DPPH and ABTS radical scavenging activities of N5 might be contributed by its higher content of fucose and rhamnose and smaller molecular weight. Noni polysaccharides extracted at stage 4 (N4) showed the highest uronic acid content (4.10 ± 0.12%), and the superior performance in scavenging hydroxyl radicals and protecting DNA. The greater hydroxyl radical scavenging effect of N4 might be attributed to its higher percentage of the low molecular weight counterpart. Moreover, the DNA protective effects of N4 displayed a positive correlation with its hydroxyl radical scavenging ability. Overall, stage 4 and stage 5 could be ideal stages of fruit maturity aiming at high-quality Noni polysaccharides extraction. This study provided valuable information for the selection of suitable Noni polysaccharides to cater for various industrial applications.