Basic Functions Research Articles

PENETRATION TESTING APPROACHES EMPLOYING THE OPENVAS VULNERABILITY MANAGEMENT UTILITY

Currently, issues of security of information systems of critical information infrastructure facilities are becoming relevant. At the same time, the current tasks of an information security (IS) audit of critical information infrastructure objects, as a rule, come down to checking them for compliance with IS requirements. However, with this approach to auditing, the resistance of these objects to real attacks by intruders often remains unclear. To test this resistance, objects are subjected to a testing procedure, namely penetration testing. The goal is a comparative analysis of existing foreign and domestic penetration testing methods and standards. The elements of novelty of the work are the identified features, advantages, disadvantages and scope of applicability of existing standards and methods of penetration testing. This article will review the OpenVAS vulnerability scanner. Readers will become familiar with the basic and advanced functions of the program; its settings depend on the functions and capabilities.

Identification of viral protease-dependent cleavage sites within the human astrovirus polyprotein.

Infection by human astrovirus (HAstV), a small, positive-strand RNA virus, is a major cause of gastroenteritis and has been implicated in an increasing number of severe, sometimes fatal, neurological diseases since 2008. Currently, there are no vaccines or antiviral treatments available to treat HAstV infection. An attractive target for antiviral therapeutics is the viral protease due to its essential functions throughout infection. However, the molecular mechanisms of the HAstV protease, nonstructural protein 1a/3 (nsp1a/3), are poorly understood. In fact, the specific residues within the cleavage junctions that are targeted by nsp1a/3 during polyprotein processing have yet to be experimentally identified. To identify the junctions between viral proteins, we performed mass spectrometry and site-directed mutagenesis using epitope-tagged viral polyprotein expression plasmids. Using these strategies, we identified a consensus motif that is found throughout the polyprotein near previously proposed junctions. We found that cleavage occurs after a hydrophobic residue - X - Gln motif. Further mutagenesis of surrounding sequence identified the importance of basic residues following the motif for efficient processing. Cleavage at each junction was determined to be essential for the production of progeny virions. However, abolishing nsp1a/4-VPg cleavage allowed efficient replication, suggesting that VPg can function in an intermediate form. Overall, our results identify a conserved cleavage motif that is recognized by the nsp1a/3 protease within the viral polyprotein, and cleavage at this motif was found to be essential for the recovery of progeny virions. These findings will be instrumental in further understanding the basic functions of HAstV polyprotein processing during infection.IMPORTANCEHuman astroviruses (HAstVs) are a leading cause of non-bacterial gastroenteritis in children, elderly individuals, and immunocompromised patients. However, infection by divergent strains of HAstV is now recognized as a causative agent of severe neurological diseases, which can have fatal outcomes. Despite the global prevalence of HAstV, we currently have a limited understanding of the biology of these viruses. Translation of the viral genome leads to the production of polyproteins that are processed by viral and host proteases into functional proteins. In this study, we identified a conserved recognition sequence targeted by the viral protease for cleavage. Importantly, these findings elucidate the N- and C-termini of the nonstructural proteins within the HAstV polyprotein, offering valuable information for future studies on the function of individual viral proteins. Similar to other positive-sense RNA viruses, the necessity of proteolytic processing for the HAstV polyprotein highlights the viral protease as a promising target for antiviral development.

Homo academicus in Transition

Modern universities, especially the ones not belonging to the small elite group from the top of the world ranking lists, but occupying the slippery terrain of the open market of the “economy of knowledge”, are forced to change the traditional, habitual modes of work, principles and values, and are considered obliged to perform as more competitive, responsible, and efficient in the eyes of the society and the world of the new era. Broadly, this is the framework of the explanation of the huge scientific-professional hyperproduction treating the university changes, both in the world context and our domestic one. Here the focus is on the Belgrade University and the modes in which the members of this institution relate to the changes in the socio-economic, political, and cultural context, that influence the development of the local academic community and its “culture”. The paper is the result of the research conducted during 2022 and 2024, based mainly on the interviews with several full professors of the Belgrade University. The aim has been to reach the most authentic insight into the experience of working at this University during the 30-year long period of transition in Serbia. According to the statements of my interviewees, the “Bologna reform” in the widest sense of this term is habitually taken to represent the reference point of the higher education “transition”, according to which we can observe the key changes in this area, directly or indirectly linked to the process of the wider social transition. The vast material was first systematized according to the chronological principle, dividing the process of transition into three decades, where my interlocutors compared the conditions and changes that accompanied and determined the university work. The material was then systematized according to the qualitative principle, singling out the most important changes that the interviewees experienced themselves or observed in their surroundings, in respect to two basic functions of university: teaching and research. The theoretical-methodological postulation of this approach is that the members of an academic community share the so-called “academic culture” and that the characteristics of this culture and the ways it changes (or remains the same) may only be approached by focusing on individuals and the modes in which they change their social actions, interpret and modulate the newly acquired culture, due to the pressures of the changing conditions.

Research on performance curve prediction of centrifugal pump based on improved whale optimization algorithm and characteristic deformation method

This article proposes an improved hybrid method combining whale optimization algorithm (IMWOA) and the characteristic deformation method (CDM) to predict the performance curve of centrifugal pumps. The traditional whale optimization algorithm (WOA) is enhanced by introducing chaos mapping, adaptive weight, nonlinear convergence factor strategies, and mutation concept from the genetic algorithm. These improvements make IMWOA significantly superior to the traditional WOA in the basic criterion test functions. To address the limitations of sample set size and differences in data characteristics in practical applications, this paper also introduces CDM strategies, including dynamic parameter adjustment strategy and mixed standardization strategy. Comparative analysis shows that the IMWOA-CDM method achieves better results in various performance evaluation indicators. The final experimental results validated the high accuracy and reliability of the IMWOA-CDM method in predicting the performance curve of centrifugal pumps, with a maximum absolute error of 1.21 m for head and 1.08% for efficiency.

Urban Landscape Resilience: Reconnecting the River with Al-Kut’s Traditional City Centre

The importance of this study is due to its direct interest in the river bank of the Kut city centre and its concern for reconnecting its traditional part with the basic functions of the entire city. Here, the resilience of the Iraqi city of Kut can be enhanced and its viability increased. The aim of the study is to establish a comprehensive framework for the study of the various cultural and historical aspects of the study area with a view to reconnecting the city with its river. The research here focuses on the importance of the principle of urban resilience in urban design, and these activities include attention to open spaces and linking them to motor hubs to increase their urban resilience. Furthermore, it is imperative to prioritise pedestrian and bicycle traffic in public areas, while also ensuring the preservation of the city's historical aspects as tourist attractions. Additionally, residents should be provided with optimal comfort and safety. The study suggests using a shared stakeholder strategy to address the many challenges in the investigated region. By integrating the principles of ecosystem-based adaptation and social equity, a resilient urban environment can be created that can withstand future shocks and pressures. The research implies that the city's historic status and citizens' quality of life are poor so that the situation can be rectified and the river's relevance highlighted. Strategies can be established and enhanced to adapt to the riverside and preserve it for future generations in a more flexible and sustainable manner.

Emerging Role of Sorting Nexin 17 in Human Health and Disease.

The distortion of the cellular membrane transport pathway has a profound impact on cell dynamics and can drive serious physiological consequences during the process of cell sorting. SNX17 is a member of the Sorting Nexin (SNX) family and plays a crucial role in protein sorting and transport in the endocytic pathway. SNX17, SNX27, and SNX31 belong to the SNX-FERM subfamily and possess the FERM domain, which can assist in endocytic transport and lysosomal degradation. The binding partners of SNX27 have been discovered to number over 100, and SNX27 has been linked to the development of Alzheimer's disease progression, tumorigenesis, cancer progression, and metastasis. However, the role and potential mechanisms of SNX17 in human health and disease remain poorly understood, and the function of SNX17 has not been fully elucidated. In this review, we summarize the structure and basic functions of SNX protein, focusing on providing current evidence of the role and possible mechanism of SNX17 in human neurodegenerative diseases and cardiovascular diseases.

Ultraweak light-modulated heterostructure with bidirectional photoresponse for static and dynamic image perception

The human visual system’s adaptability to varying brightness levels has inspired the development of optoelectronic neuromorphic devices. However, achieving bidirectional photoresponse, essential for mimicking these functions, often requires high operation voltages or high light intensities. Here, we propose a bidirectional ZnO/CsPbBr3 heterostructure based neuromorphic image sensor array (10 × 10 pixels) capable of ultraweak light stimulation. The device demonstrates positive and negative photoconductivity through the ionization and deionization of oxygen vacancies in the ZnO channel, extendable to other ZnO/perovskites and IGZO/perovskites heterostructures. Operating at a reduced bias voltage of 2.0 V, the array achieves synaptic weight updates under green (525 nm) and UV (365 nm) light with light intensities ranging from as low as 45 nW/cm² to 15.69 mW/cm², mimicking basic synaptic functions and visual adaptation. It performs multiple image pre-processing tasks, including background denoising and encoding spatiotemporal motion, achieving 92% accuracy in pattern recognition and 100% accuracy in motion clustering. This straightforward strategy highlights a potential for intelligent visual systems capable of real-time image processing under low voltage and dark conditions.

Comparison of the verbalization of “heroes” in the author’s tale and the folk tale (based on the tales of P.P. Bazhov “The Malachite Box” and “The Stone Bowl”)

INTRODUCTION. Philological study of texts is a new step in studying the entire repertoire of the fairy tale fund in a wide comparison with the texts of other works. Philologists, writers, screenwriters use the concept of V.Ya. Propp and the methodology of A.J. Greimas in modern text theory. Close attention is paid to the concept of actant, actant model and basic functions in fairy tales, which are important for constructing the plot of any text, building a scheme of functional characters. The purpose of the study is to compare the characters of the author’s fairy tale by P.P. Bazhov “The Malachite Box” with the Ural folk tale “The Stone Bowl”.MATERIALS AND METHODS. By means of functional analysis, based on the concept of the famous Russian philologist, folklorist V.Ya. Propp (1895–1970) and actantial analysis, developed by the French linguist, philologist A.J. Greimas (1917–1992), we can see the structure of the fairy tale text, identify its actantial model and describe its specificity, which reflects the culture of the people.RESULTS AND DISCUSSION. The results obtained during the study have added to the body of achievements in folklore studies and linguacultural studies. The philological method of identifying actant models used in the work allows scientists to better see the cultural specificity of the Ural people. The methods of work can be used to study not only folklore texts, but also for authorial works.CONCLUSION. The research of V.Ya. Propp and A.J. Greimas allows us in our time, using the seven-character scheme of V.Ya. Propp and the actant model of A.J. Greimas, to analyze any text, designating the meanings of actants and their functions. The conclusions of this study can be used in the process of teaching the Russian language in classes on folklore and philological analysis of the text.

Computerised Attention Functions Training Versus Computerised Executive Functions Training for Children with Attention Deficit/Hyperactivity Disorder: A Randomised Controlled Trial

Computerised Attention Functions Training Versus Computerised Executive Functions Training for Children with Attention Deficit/Hyperactivity Disorder: A Randomised Controlled Trial

Exploring socio-economic inequalities in access to the 15-minute city across 200 Swedish built-up areas

In recent years, the 15-minute city has gained prominence as a vision for urban development, aiming to create attractive and vibrant neighborhoods where essential services are within a 15-minute walk. However, its implementation raises concerns about socio-spatial segregation, as the potential increase in desirability of these neighborhoods—combined with various underlying factors—can lead to increased housing prices, potentially excluding economically vulnerable groups. Despite its popularity, few studies have thoroughly explored how access to the 15-minute city varies among different socio-economic groups and across different cities and towns, highlighting a significant research gap. This study aims to explore potential socio-economic inequalities in 15-minute city access across the 200 largest built-up areas in Sweden. Specifically, our study compares average incomes among residents living in neighborhoods that either meet or do not meet various 15-minute city criteria within each built-up area. These criteria are designed to operationalize the proximity dimension of the 15-minute city by capturing which residents that have access to different sets of non-work urban social functions (e.g., healthcare, restaurants, retail) within 1 km from their homes. Two research questions guide the study: Are there differences in access to the 15-minute city, in terms of proximity to non-work urban social functions, across different income groups in Swedish built-up areas? How do variations in the types of functions included in the 15-minute city model, as well as differences in built-up areas characterized by population size, density, land use mix, and the proportion of older buildings, affect these outcomes? Findings reveal significant impact from both the definition of the 15-minute city and across different types of built-up areas. When the 15-minute city only encompasses basic functions such as a grocery store, school, restaurant, etc., average incomes are lower, irrespective of population size. However, mean incomes are notably higher for residents who can locally access many different urban social functions, indicative of larger cities with a higher population density and jobs-to-worker ratio. This highlights a cautionary aspect for cities and planners implementing the 15-minute city vision, as the city characteristics strongly correlated with effective adherence to the 15-minute city may also contribute to excluding lower-income groups.

Neuropsychological performances and brain perfusion patterns in patients with first episode psychosis

Abnormalities in cognition are a pronounced feature in primary psychotic disorders and may appear long before the manifestation of the first-episode psychosis (FEP). Although brain functional changes may precede structural alterations, brain perfusion patterns in FEP and most importantly their correlations with cognition remain poorly understood. In the present study we assessed neurocognitive functions and regional cerebral blood flow (rCBF) in 53 patients with a diagnosis of FEP. A special emphasis was placed on the assessment of basic executive functions. Cerebral perfusion patterns were measured by SPECT rCBF scintigraphy in cerebral lobes bilaterally and Brodmann Areas (BAs).Patients showed impairments in long-term verbal memory, processing speed/response latency and executive cognition. Pathological perfusion was prominent in the limbic lobes bilaterally. BAs with the largest hypoperfusion, were the subgenual area (BA25) and hippocampal areas (BA 28 and 36). The left temporal lobe was also hypoperfused, and specifically the inferior temporal gyrus (BA 20), the left middle (BA 21) and superior (BA 22) temporal gyrus, and the temporal pole (BA 38). Hypoperfusion was limited in the frontal regions, although specific BAs displayed pathological perfusion (i.e., BA 24). Cerebral lobe perfusion was not correlated with compromised cognitive abilities.

Molecular design strategy for microorganism discrimination based on keto-salicylaldehyde azine derivatives

The rapid and selective identification of microorganisms is of great significance for clinical therapy applications. To develop high performance probes for microbe determination, we systemically constructed series aggregation-induced emission (AIE) luminogens by modulating the structural planarity, the basicity of functional group, the length of linker moiety and the hydrophobicity based on our previous work. The detail structure-property relationship study based on experimental and theoretical observation revealed that: i) the planar skeleton is essential for probe insertion towards the cell wall via van n der Waals' force. ii) the basic function group enable the anchoring on the membrane by binding with acidic biomolecules. iii) the shortened alkyl chain is in favor of the efficient binding of basic groups with microbes and endows the desirable hydrophobicity. Based on the developed probes, the successful detection of the pathogens in clinic samples was achieved in highly sensitive and simple way. This work provides a reliable strategy for designing intelligent luminogens for microorganism discrimination and identification in efficient and sensitive way for in vitro diagnosis applications, especially point-of-care testing (POCT).

A comparative analysis of partial sleep restriction versus split sleep regimen on cognitive processing, declarative memory, and affective behaviour in nursing students

Objectives: Sleep plays a regulatory role in functions such as abstraction, fluid intelligence, and declarative memory. This research seeks to assess the influence of two sleep restriction schedules—partial nocturnal sleep restriction and a split sleep (SS) regimen—on fluid intelligence and various memory functions (including encoding, consolidation, and retrieval) in shift-working nurses. Materials and Methods: The research involved 46 4th-year nursing students (23 males and 23 females) assigned to night duties, categorised into two groups: Partial sleep restriction (5 h of night sleep with 4 h of daytime recovery sleep) and SS (5 h of night sleep with 1.5 h of an afternoon nap and recovery sleep of 2.5 h following the tests). Instruments such as the Pittsburgh sleep quality index (PSQI), Karolinska sleepiness scale (KSS), and Raven’s Progressive Matrices were utilised to evaluate sleep quality, sleepiness levels, overall mood, benefits of daytime naps, and fluid intelligence. Memory-related activities comprised a picture-encoding task and a factual knowledge task, evaluated through subjective assessments and two alternative choice questions. Results: The PSQI global scores highlighted notable differences, with female nursing students in the partial sleep group scoring lower (9 ± 2.311) than their counterparts in the SS group (5 ± 1.09). Sleepiness, gauged by the KSSKSS score, was higher in the partial sleep group (7 ± 3.2) compared to female nursing students in the SS regimen (5 ± 5.8). Results from Raven’s progressive matrices pointed to delayed abstraction in the partial sleep restriction group (9.31 ± 6.24) in contrast to the SS group (9.01 ± 5.59), indicating poorer performance in visual attentive tasks. Positive and negative affect schedule scores unveiled heightened negativity in mood due to sleep restriction in the partial sleep group, with less hostility observed in those with an afternoon nap, albeit not reaching statistical significance. Positive moods exhibited fluctuation, with attentiveness declining in the partial sleep group. The study affirmed the advantages of a daytime nap on long-term memory. Female nurses in the SS regimen displayed statistically significant picture encoding accuracy (78 ± 3.65) with faster reaction times (2 ± 6.37) compared to the partial sleep group. Males in the SS regimen recorded a higher percentage of hits (88 ± 5.16). Learning sessions at 3 pm, coinciding with the circadian dip, affected the partial sleep groups, whereas the nap mitigated such effects for the SS group. Allowing a 1.5-h afternoon nap synchronised with the circadian dip enhanced memory in the SS group. Conclusion: By comparing partial nocturnal sleep restriction and a SS regimen, this study unveils their distinct effects on fluid intelligence and memory processes among shift-working nurses. The results provide valuable insights into the degree of dependence of basic cortical functions on sleep for healthcare professionals navigating demanding schedules, underscoring the significance of accounting for both nocturnal sleep duration and daytime naps to optimise cognitive performance.

MACARONI AND MANAGEMENT: PRODUCING CULINARY DEMONSTRATIONS TO TEACH THE FOUR FUNCTIONS OF MANAGEMENT AND FACILITATING CLASSROOM PERFORMANCE IMPROVEMENT

Visual learning has become an important tool in higher education, particularly in the field of management in which students need to acquire skills that will prepare them for employment after graduation. Many institutions have embraced visual learning technology as an effective pedagogy method, especially since the COVID-19 pandemic changed the way instructors deliver knowledge. The usage of video technology is particularly useful in business management programs, in which it can enhance learning opportunities. The author of this study is an assistant professor teaching graduate and undergraduate business and hospitality courses, and he has used video technology to record cooking demonstrations that illustrate management principles to undergraduate students. The approach has been well-received, and academic performance has improved. The study focuses on one example of a culinary demonstration that explains the four basic functions of management. The results reveal positive correlations between the pedagogical approach and classroom assessment performance.

The exocyst complex controls multiple events in the pathway of regulated exocytosis.

Eukaryotic cells depend on exocytosis to direct intracellularly synthesized material toward the extracellular space or the plasma membrane, so exocytosis constitutes a basic function for cellular homeostasis and communication between cells. The secretory pathway includes biogenesis of secretory granules (SGs), their maturation and fusion with the plasma membrane (exocytosis), resulting in release of SG content to the extracellular space. The larval salivary gland of Drosophila melanogaster is an excellent model for studying exocytosis. This gland synthesizes mucins that are packaged in SGs that sprout from the trans-Golgi network and then undergo a maturation process that involves homotypic fusion, condensation, and acidification. Finally, mature SGs are directed to the apical domain of the plasma membrane with which they fuse, releasing their content into the gland lumen. The exocyst is a hetero-octameric complex that participates in tethering of vesicles to the plasma membrane during constitutive exocytosis. By precise temperature-dependent gradual activation of the Gal4-UAS expression system, we have induced different levels of silencing of exocyst complex subunits, and identified three temporarily distinctive steps of the regulated exocytic pathway where the exocyst is critically required: SG biogenesis, SG maturation, and SG exocytosis. Our results shed light on previously unidentified functions of the exocyst along the exocytic pathway. We propose that the exocyst acts as a general tethering factor in various steps of this cellular process.

The exocyst complex controls multiple events in the pathway of regulated exocytosis

Eukaryotic cells depend on exocytosis to direct intracellularly synthesized material toward the extracellular space or the plasma membrane, so exocytosis constitutes a basic function for cellular homeostasis and communication between cells. The secretory pathway includes biogenesis of secretory granules (SGs), their maturation and fusion with the plasma membrane (exocytosis), resulting in release of SG content to the extracellular space. The larval salivary gland of Drosophila melanogaster is an excellent model for studying exocytosis. This gland synthesizes mucins that are packaged in SGs that sprout from the trans-Golgi network and then undergo a maturation process that involves homotypic fusion, condensation, and acidification. Finally, mature SGs are directed to the apical domain of the plasma membrane with which they fuse, releasing their content into the gland lumen. The exocyst is a hetero-octameric complex that participates in tethering of vesicles to the plasma membrane during constitutive exocytosis. By precise temperature-dependent gradual activation of the Gal4-UAS expression system, we have induced different levels of silencing of exocyst complex subunits, and identified three temporarily distinctive steps of the regulated exocytic pathway where the exocyst is critically required: SG biogenesis, SG maturation, and SG exocytosis. Our results shed light on previously unidentified functions of the exocyst along the exocytic pathway. We propose that the exocyst acts as a general tethering factor in various steps of this cellular process.

Physicochemical and functional properties of yogurt enriched with ultrafiltered juice of Red Prickly Pear (Opuntia ficus-indica) as a functional ingredient

Yogurt has long been recognized as a health-promoting food for its bioavailability of protein, energy, probiotics and calcium, increasing digestibility, as well as preventing potential diseases beyond basic nutritional function. Recently, yogurt has become one of those foods whose functional properties are developed by adding functional substances with a potential positive effect on health. The objective was to evaluate the effect of ultrafiltered juice of red fruits of O. ficus-indica as a functional ingredient in yogurt. A completely randomized block design (CRBD) was used. The treatments were: yogurt with 0 % ultrafiltered red prickly pear juice (Y0) as a control; yogurt with 10 % ultrafiltered red prickly pear juice (Y1); yogurt with 20 % ultrafiltered red prickly pear (Y2); and yogurt with 30 % ultrafiltered red prickly pear juice (Y3). The variables to measure in each yogurt treatment were pH during lactic fermentation and the final product, syneresis, energy content, colorimetry, composition (total solids, protein, fat and ash), antioxidant activity (DPPH, ABTS and FRAP), phenol content and sensory evaluation. The incorporation of red prickly pear ultrafiltrates accelerated antioxidant activity and total phenolic contents. Finally, the sensory panel satisfactorily accepted the incorporation of red prickly pear ultrafiltered in yogurt. DOI: https://doi.org/10.54167/tch.v18i4.1614

The application of hepatopancreatoduodenectomy in advanced gallbladder carcinoma: Patients’ selection, surgical outcome and influence on survival compared to radical cholecystectomy

Aimto investigate hepatopancreatoduodenectomy (HPD) application in gallbladder carcinoma (GBC) and compare it to radical cholecystectomy (RC) regarding patients’ characteristics, surgical outcome and survival. MethodsPatients treated in our center were included. Three groups (HPD, RC, no-surgery) were compared. Comparisons included basic characteristics, liver function, tumor biomarkers, surgical complications, outcome, and survival. Differences in severity, surgical risks and survival were investigated. ResultsIn total, 19 patients in HPD, 89 in RC and 20 in no-surgery groups were included. Median follow-up was 42.0 months. Compared to RC, HPD group revealed increased severity represented by significantly higher rates of elevated ALT, AST, TB, DB, preoperative biliary decompression, T3/4, N1/2, stage III/IV, and MVI. Similar severity was observed between HPD and no-surgery groups. Additionally, HPD presented higher risks of perioperative bleeding, transfusion and complications (grade III/IV). Pancreatic fistula and delayed gastric emptying were most encountered in HPD and only one mortality was recorded. Although HPD had shorter survival in general population (HPD: 17 ± 5.804, RC: 49 ± 11.433,P < 0.001); however, in matched (PSM) advanced stages, its benefits matched RC (HPD: 17 ± 4.793, RC: 11 ± 1.169, P = 0.966). Significant survival advantages were observed when comparing HPD to no-surgery group (HPD: 17 ± 5.804, no-surgery: 7 ± 0.836, P = 0.013). ConclusionCases benefiting from HPD are usually severe and comparable to unresectable cases. Although HPD complexity and complication risks are higher than RC, the survival benefits of HPD in advanced GBC stages are not inferior. Thus, HPD is a valuable option in such patients and can be the only approach to achieve R0 resection.

Macromolecular crowding agent dependent extracellular matrix deposition and growth factor retention in human corneal fibroblast cultures

The major obstacle in the commercialisation and clinical translation of tissue engineered medicines is the required for the development of implantable tissue surrogates prolonged in vitro culture. Macromolecular crowding (MMC) enhances and accelerates extracellular matrix (ECM) deposition, thus offering an opportunity to bridge the gap between research and development in tissue engineered substitutes. However, the optimal MMC agent is still elusive. Herein, we first assessed the biophysical properties of the most widely used MMC agents [κλ carrageenan (κλ CR), λ carrageenan (λ CR) and Ficoll™ cocktail (FC)] and then assessed their effect in basic cell function, ECM deposition and growth factor retention in human corneal fibroblast (hCF) cultures. Dynamic light scattering analysis revealed that both CR macromolecules had significantly lower and higher zeta potential and hydrodynamic radius, respectively, than the FC. None of the MMC agents affected hCF morphology and all induced similar hCF viability, proliferation and metabolic activity. Electrophoresis and immunofluorescence analyses made apparent that at day 10 (longest time point assessed), the FC brought about the highest fibronectin and collagen types I, III, IV, V and VI deposition. Deposited ECM pattern analysis showed that at day 10, the FC induced the lowest lacunarity and normalised end points and the highest fractal dimension and % high density matrix. Further immunofluorescence analysis revealed no significant differences between the groups in vimentin, aldehyde dehydrogenase 3 family member A1, keratocan, paired box protein 6 and α-smooth muscle actin. Importantly, at day 10, the FC resulted in the highest growth factor retention (20 molecules). Our data clearly illustrate a MMC agent dependent cell response, with the FC having the highest positive effect in hCF cultures.

Analysis of physiological and biochemical changes and metabolic shifts during 21-Day fasting hypometabolism

This study aimed to evaluate the impact of prolonged fasting on the physiological and biochemical alterations and metabolic shifts in healthy adults and to provide experimental data and theoretical support for the hypometabolic state induced by prolonged fasting. Thirteen volunteers were selected through public recruitment to undergo a 21-day complete fasting experiment. The experimental period lasted 34 days, including a 3-day baseline, 21-day completing fasting, 5-day calorie restriction and 5-day full recovery diet. Physiological indicators such as body weight, blood pressure, blood glucose, blood ketones, and blood uric acid were evaluated along with resting metabolic rate, routine blood tests, liver function, and heart function indexes employing traditional approaches. During the 21-day complete fasting period, there was a significant decrease in body weight (average − 14.96 ± 1.55%), a reduction in blood glucose (average − 21.63 ± 0.058%), an increase in blood ketones (from baseline 0.1 ± 0.04 mmol/L to 6.61 ± 1.25 mmol/L) and blood uric acid (from baseline 385.38 ± 57.78 µmol/L to 866.31 ± 172.01 µmol/L), a continuous decline in resting energy expenditure (average − 20.3 ± 11.13%), and the respiratory quotient tending towards fat metabolism. Most of the items in the complete blood count and liver indicators remained stable and within the normal range. Heart function showed functional adaptive changes without structural damage. Prolonged fasting can reduce the body’s resting energy expenditure and adapt to body weight loss through physiological regulatory mechanisms without adverse effects on basic physiological functions or the structure of important organs. Under medical supervision, healthy adults can safely engage in prolonged fasting for up to 21 days with metabolic adaption and no damage to pivotal organ, which could provide potential technical support for human health and survival strategies in extreme conditions such as food shortages during long-duration manned spaceflight.