Sort by

Artiles

Article

28 May 2024

Efficacy and Cytocompatibility of a Pressure Garment—Silicone Composite Dressing Material for Scar Healing

Pressure garment therapy (PGT) and silicone gel sheeting (SGS) predominate non-invasive interventions for burn injuries, but the market lacks a composite solution combining pressure garment fabric (PGF) and medical-grade silicone (e.g. Biopor®AB) for multi-therapeutic efficacy. To address this gap, a versatile composite dressing of PGF-Biopor®AB was developed. PGF-Biopor®AB incorporates dual PGF-SGS therapy, mechanotherapy, and active moisture management, to facilitate recovery of hypertrophic subsidiary structures. The PGF structure enables the application of PGT, while the Biopor®AB silicone characteristics enforce silicone gel therapy (SGT). The PGF-SGS efficacy optimization not only reduces tension but also facilitates water vapor and oxygen penetration, along with hydration of the stratum corneum. Mechanotherapy, involving tension-shielding and pressure redistribution, promotes the reorganization of the collagen-fiber network. For active moisture management, the incorporation of a microchannel structure with active nylon absorbency facilitates effective moisture control through water absorption, retention, and cellular pathways of transport. In this study, the microscale features in the structure were further investigated. Under ISO 10993-5 standard, an over 70% cell viability in 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay containing the L929 cell line verified the enhanced cell growth and inhibited proliferation, endorsing the safe usage of PGF-Biopor®AB. Patient studies of one-month efficacy in both high and low-cell-density samples and an early scarless healed wound suggest that over 70% cell viability is sufficient for optimal scar therapeutics. The multifaceted scar repair roles are fulfilled by addressing persistent inflammation, insufficient oxygenation, low levels of perfusion, and scar-healing tension, hence realising the multi-therapeutic efficacy of the composite dressing.

Keywords: Pressure garment; Silicone; Composite dressing; Dual therapy; Scar-healing

Article

27 May 2024

The Strange Question of Species: Biocratic Implications in Interwar Paleoanthropology

Species was one of the most controversial concepts in biological science. Not even the “New Systematics” of the 1930s and 1940s succeeded in bringing complete clarity to the issue. During the first half of the twentieth century the conceptualization of species was challenged by paleontology, a then-emerging discipline, but an ancient essentialist conception resisted, whereby each species is characterized by its own immutable essence (eidos). This simplification was transferred to physical anthropology in the study of human populations, with further cultural and political outcomes. For example: the meaning of species developed a series of biopolitical and legal implications regarding the construction of a society preserved from foreign dangerous bodies. From this perspective, the racial policy of the Third Reich established that the German national community was to be based on belonging to a same species (Art), from which Jewish population was excluded, considering it an alien species (Artfremd) and therefore incompatible. The concept of species, defined from an essentialist perspective, was in fact considered more differentiating and selective than that of “race”. Consequently, foreignness to the human species became a more radical distinguishing factor than racial classification. The article, with a focus on German academia, aims to reconstruct the debate in paleoanthropology during interwar period.

Keywords: Species; Race; Human populations; Polygenism; Essentialism; Biocracy; Eugenics; Nazi regime

Review

24 May 2024

Current Progress on Microbial l-malic Acid Production

As an important intermediate in the tricarboxylic acid (TCA) cycle, l-malic acid (l-MA) is also one of the 12 important platform bulk chemicals with high added value. Owing to its various applications in food, pharmaceuticals, cosmetics and industry, the global l-MA market size is growing year by year. Over the last few decades, increasing concerns regarding fossil fuels depletion and excessive CO2 emissions have led the global commitment to fostering a green economy and sustainable development. Alternatively, the sustainable microbial fermentation of l-MA has gradually attracted more and more attention. Here, this review summarizes the common l-MA biosynthesis pathways and compares the differences between different chassis microorganisms as well. Moreover, regulation strategies of genetic metabolic engineering and fermentation process to boost the l-MA production are summarized, and the research status of l-MA production from the cheaper substrates is also discussed. Finally, the direction of further exploration of industrialized l-MA biosynthesis is proposed, which provides a theoretical guidance on promoting technological innovation in industrial l-MA production.

Keywords: l-malic acid; Microbial biosynthesis; Strain engineering; Process optimization

Article

23 May 2024

Proposal for A Systemic Human Ecological Turn for Health Science and Medicine

Industrial development processes, accompanied by extreme growth processes, regards world population, pollution, food production and the exploitation of natural resources have caused severe ecological problems. This has been well known since 1972 through the study ‘The Limits to Growth’, in which humanity and the world society was called upon to make an ecological turn and to change its consumption model and the type of economic development that was not suited to finite natural resources (or a finite planet). However, the relationships between the state of the environment and human health have hardly been considered, although an ecological view of health was already proposed by Hippocrates, and as in the meantime, the technical terms “Environmental Health” and “Environmental Medicine” have become established at universities. It is only in recent times that global terms such as climate medicine, One Health, Eco Health, etc. have become powerful pragmatic and action-oriented initiatives. They can be understood as calls for a worldwide health-related ‘ecologization’ of (health) culture. Regarding these approaches we highlight theoretical and metatheoretical aspects, since in general, any real action is only as good as the analytical quality of the plan that serves as a guide for that action. From this point of view, we find that these approaches exhibit striking weaknesses. These are, among other things: the neglect of epistemological challenges combined with inconsistent conceptualizations of the category environment, the very superficial models of human beings, weaknesses of ecological frameworks in relation to the macro-, meso- and micro-eco-social levels of the targeted topics, and a vague notion of systems methodology. Following on from this, we call for an explicit social-/human-ecological framework (New Viennese School, Australian School) for environmental health issues as it has been established for decades in the field of environmental, sustainability and transformation sciences.

Keywords: Global environmental health initiatives; Human ecology; Anthropological medicine; Transdisciplinary knowledge integration; Systems thinking

Article

23 May 2024

Numerical Study on Pyrolysis Characteristics of Oil-Based Drilling Cuttings in a Two-Layer Screw-Driving Spiral Heat Exchanger

Oil-based drilling cuttings is a pollutive nearly-solid waste produced in oil exploitation that has to be treated for meeting clean production requirement of oil and gas exploration. A two-layer screw-driving spiral heat exchanger was thus proposed for this purpose. To investigate its effectiveness and performance, a 10-component n-decane one-step product proportional distribution chemical model was used to describe oil-based drilling cuttings pyrolysis process, and numerical simulations were carried out of forced convection inside the heat exchanger with a full consideration of pyrolysis and evaporation effects. The influences of rotation speed, screw pitch and cross-sectional shape of spiral tube on pyrolysis, flow, and heat mass transfer characteristics were studied. The results show that the heat absorbed needed for evaporation is much less than that for pyrolysis, and the heat transfer coefficient with consideration of evaporation and pyrolysis is almost two times greater than that without. The pyrolysis rate increases first, and then decreases once the temperature is higher than 838 K due to the coupled effects of temperature and reactant concentration change. The velocity, heat transfer coefficient and conversion ratio of oil-based drilling cuttings all increase with rotation speed, but the conversion ratio increase becomes slower and slower once the rotation speed exceeds 0.2 rad·s−1. The average vorticity and flow resistance of oil-based drilling cuttings both decrease with screw pitch monotonously, while heat transfer coefficient increases first and then decreases because of the opposite effects of centrifugal force and thermal entrance length. Reducing screw pitch can increase conversion ratio, but once screw pitch is smaller than 800 mm, the conversion ratio approaches to a constant. Cross-sectional shape of spiral tube also affects pyrolysis performance, and circular cross-sectional spiral tube seems to be the best.

Keywords: Pyrolysis; Oil-based drilling cuttings; Numerical simulation; Heat and mass transfer

Review

20 May 2024

Advancements in the Bio-degradation of Plastic Waste into Value-added Chemicals: A Recent Perspective

Plastics are an essential component of modern life, but the plastic waste has caused significant environmental pollution and economic losses. The effective solution to these problems is the biodegradation and high-value conversion of plastic waste. After biodegradation, plastic waste is broken into smaller molecules and eventually transformed into innocuous substances like water, carbon dioxide and biomass. High-value conversion enables plastic waste to be converted into products with higher economic value and environmental friendliness. Based on this, we summarize the biodegradation methods of bioplastics and analyze the shortage of these methods. Subsequently, we summarize the progress of converting the degradation products into value-added chemicals, comprehensively analyze the advantages and disadvantages of these bioconversion process, and propose some strategies to address these disadvantages. Finally, we analyze the significance of establishing a microbial-based conversion process that integrates the degradation and the conversion, and propose some potential strategies.

Keywords: Bioplastics; Bioconversion; Biodegradation

Article

17 May 2024

Review

16 May 2024

The Application of Forensic Imaging to Sex Estimation: Focus on Skull and Pelvic Structures

Forensic imaging is recognized as a vital tool in forensic practice mostly reflected by the wide use of post-mortem imaging in death investigations. With the surge of forensic imaging applications and research in recent years, many forensic subdisciplines have adopted this tool as a scientific investigation method, including forensic anthropology. Sex estimation is one of the key assignments in forensic anthropology along with age, ancestry and stature estimation. Traditionally, this assignment is done with non-metric macroscopic examination and metric analysis performed by forensic anthropologists. Today, forensic imaging serves as an auxiliary tool that adds to traditional methods and brings sex estimation to a dynamic era. The purpose of this article is to review forensic imaging methods in forensic anthropology sex estimation with a focus on skull and pelvic structures, aiming to provide insights into the best practices and prospective research directions. 

Keywords: Forensic imaging; Forensic anthropology; Macroscopic examination; Metric analysis; Sex estimation

Article

14 May 2024

Measurement and Structure of Common Prosperity of Urban Residents the Case of Hangzhou, China

Common prosperity is an important feature of the social state that the people of the world aspire to, and an important feature of the Chinese path to modernization. Taking common prosperity as the result of income and assets does not facilitate a full understanding of people’s common prosperity, because common prosperity also includes people’s pursuit of subjective happiness such as happiness and satisfaction. From the perspective of the need for a better life in China, this study constructs a subjective evaluation system of the common prosperity of urban residents, including 5 dimensions and 25 specific indicators. It uses survey data from 460 participants and applies the graded response models to estimate parameters and predict latent variables. We find that 21 indicators are in line with the reasonable range of basic assumptions and parameters. They have a strong ability to distinguish the common prosperity of residents in different regions, but have different functional characteristics. The confirmatory factor analysis shows that the common prosperity index of residents includes four potential factors: income, education, medical care, and old-age care, and ecology, which has a good structural effect. In terms of weight, education, medical care and old-age care are the most important factors influencing common prosperity. Among them, the classification policy of high school entrance examination, the quality and fairness of primary and secondary education, the degree of medical insurance security, and the waste sorting and community security are important aspects of evaluating the Common prosperity of residents. 

Keywords: Subjective cognition of the need for a better life; Common prosperity; Graded Response Models; Measurement; Influence Factors

Article

13 May 2024

Expression of Redox Partner Fusions for Light Driven Cytochrome P450s in the Cyanobacterium Synechocystis PCC. 6803

Cytochrome P450s (P450s) catalyze stereo- and regioselective monooxygenations in the biosynthesis of a wide range of valuable natural compounds. The turnover of P450s requires dedicated electron transfer, usually via a NADPH-dependent reductase. The need for an NADPH-dependent reductase can be circumvented if expressed in photosynthetic organisms by exploiting the photosynthetic reducing power. However, partitioning reducing equivalents towards the P450s needs further optimization. Using our model P450, SbCYP79A1, we have previously shown that by targeting this P450 to the thylakoid membrane, the P450 can obtain its reducing power directly from photosystem I via soluble ferredoxin. Furthermore, we demonstrated using transient expression that fusing a soluble electron carrier to this P450 improves electron partitioning towards the P450 in tobacco. In order to characterize these fusions in a stably transformed organism, we expressed three different redox partner fusions in the cyanobacterium Synechocystis sp. PCC. 6803. We show that biochemical trends observed in the tobacco system are recapitulated in stably transformed Synechocystis sp. PCC. 6803. Overall, the FMN binding domain fusion produces the most oxime per unit of enzyme with and without the presence of the endogenous competing electron sink FNR and NADP+. However, the overall yield of oxime is comparable to the other strains, due to poor steady state levels of the fusion protein. Synechocystis sp. PCC. strains expressing the P450-FMN fusion also display a chlorotic phenotype that can be rescued by switching the nitrogen source from nitrate to ammonia, implying impaired nitrate assimilation. Optimizing electron transport towards the P450 is indeed possible in vivo but also highlights interference with native metabolic processes.

Keywords: Cytochrome P450; Electron transfer; Protein fusions; Photosynthesis; Nitrogen
TOP