Human Body Research Articles

Modelling human postural stability and muscle activation augmented by a supernumerary robotic tail.

Wearable robots have promising characteristics for human augmentation; however, the the design and specification stage needs to consider biomechanical impact. In this work, musculoskeletal software is used to assess the biomechanical implications of having a two-degrees-of-freedom supernumerary robotic tail mounted posterior to the human trunk. Forward and backward tilting motions were assessed to determine the optimal design specification. Specifically; the key criteria utilised included the centre of pressure, the dynamic wrench exerted by the tail onto the human body and a global muscle activation index. Overall, it was found that use of a supernumerary tail reduced lower limb muscle activation in quiet stance. Furthermore, the optimal design specification required a trade-off between the geometric and inertial characteristics, and the amount of muscle assistance provided by the tail to facilitate safe physical Human-Robot interaction. &#xD.

Risky first-in-human clinical trials on medically fragile persons: owning the moral cost.

The purpose of a first-in-human (FIH) clinical trial is to gather information about how the drug or device affects and interacts with the human body: its safety, side effects, and (potential) dosage. As such, the primary goal of a FIH trial is not participant benefit but to gain knowledge of drug or device efficacy, i.e., baseline human safety knowledge. Some FIH clinical trials carry significant foreseeable risk to participants with little to no foreseeable participant benefit. Participation in such trials would be a bad deal for participants, and the research is considered justifiable because of the promise of significant potential social benefit. I argue that there is an ethical tension inherent in risky FIH research and that researchers should fairly compensate risky FIH trial participants. This does not make the risk-benefit outcome more favorable for participants; rather, it amounts to a collective reckoning with the ethical tension inherent in the research.

Human body temperature and cardiovascular response to changes in ambient temperature and body posture

Health problems due to heat or cold exposure is closely related not only to body temperature (BT) but also to blood flow rate (BFR) and blood pressure (BP). Therefore, it is necessary to understand the physiological mechanisms of the human body, such as how these physiological quantities change and how they affect each other. In this study, to clarify the physiological mechanisms of the human body, we measured the whole-body distribution of BT and BFR, as well as BP, heart rate, and metabolic rate under changes in ambient temperature and body posture. A total of 19 subjects were tested in three cases, including the temperature up-step and down-step cases, where the ambient temperature changed from 28 °C to 38 °C or 18 °C in the supine position, and the posture change case, where the posture changed alternately between the supine and standing positions at an ambient temperature of 28 °C. The results showed that the core temperature was efficiently maintained due to BFR regulation, especially in the extremities, in response to changes in ambient temperature. Additionally, changes in cerebral BFR in response to changes in posture were suppressed due to regulation of BFR, especially in the lower limbs, and heart rate. Furthermore, in the extremities, the BFR not only in the skin but also in the subcutaneous tissue and muscle was estimated to increase in hot environments and decrease in cold environments.

Analysis of Cancer-Resisting Evolutionary Adaptations in Wild Animals and Applications for Human Oncology.

This literature review is to present a new direction in developing better treatment or preventive measures. The larger the body of an organism, the more numerous the cells, which theoretically lead to a higher risk of cancer. However, observational studies suggest the lack of correlation between body size and cancer risk, which is known as Peto's paradox. The corollary of Peto's paradox is that large organisms must be cancer-resistant. Further investigation of the anti-cancer mechanisms in each species could be potentially rewarding, and how the anti-cancer mechanisms found in wild animals can help influence and develop more effective cancer treatment in humans is the main focus of this literature review. Due to a lack of research and understanding of the exact molecular mechanisms of the researched species, only a few (Elephants and rodents) that have been extensively researched have made substantive contributions to human oncology. A new research direction is to investigate the positively selective genes that are related to cancer resistance and see if homologous genes are presented in humans. Despite the great obstacle of applying anti-cancer mechanisms to the human body from phylogenetically distant species, this research direction of gaining insights through investigating cancer-resisting evolutionary adaptations in wild animals has great potential in human oncology research.

Changes in the liver of Djungarian hamsters under conditions of a three-month supply of water-soluble silicon of various concentrations

BACKGROUND: Silicon enters the human body through drinking water, air and food. Silicon nanoparticles used in the cosmetic, pharmaceutical and food industries are known to have biological activity. Taking into account the widespread prevalence of silicon compounds, the issue of the safety of its use is becoming more urgent. AIM: To study the effect of water-soluble silicon on the morphological structure of the liver of Djungarian hamsters for three months. MATERIALS AND METHODS: The experiment was carried out on Djungarian hamsters kept in normal vivarium conditions under natural light. The animals were divided into three groups: control, which received bottled drinking water; the first experimental group, which received the same water, but with the addition of sodium metasilicate nine-hydrate at a concentration of 10 mg/l in terms of silicon; the second experimental group, which also received the same water, but with the concentration of sodium metasilicate nine-hydrate doubled (up to 20 mg/l). After three months, the animals were removed from the experiment. Sections were processed by general histological (hematoxylin and eosin, Van Gieson method, toluidine blue), histochemical (monoamine oxidase-positive cells) methods. RESULTS: In the liver of hamsters from the experimental groups, changes in the micromorphological structure were revealed, such as an increase in the nuclear area, nuclear-cytoplasmic ratio of hepatocytes, and the diameter of sinusoidal capillaries. Moreover, more pronounced changes were observed in the liver of hamsters of the second experimental group, such as polymorphic cell infiltration of the portal tracts, an increase in the number of eosinophils, deformation of hepatocyte nuclei and the appearance of apoptotic bodies. A decrease in the area of mast cells and an increase in their number, as well as the number of monoamine oxidase-positive cells in the liver of hamsters of both experimental groups were recorded. CONCLUSIONS: An increase in the concentration of silicon supplied with drinking water in both cases is reflected in the micromorphological structure of the liver of hamsters. Moreover these changes are more pronounced in the liver of hamsters of the second experimental group.

Adsorption of Fluoride Ions Using Si–Al–Mg Layered Double Hydroxides

ABSTRACT Removal of fluoride ions from water environments has become a research topic because high concentrations of fluoride ions in drinking water are harmful to the human body. The adsorption of fluoride ions by a Si – Al – Mg layered double hydroxide (LDH) was investigated in this study. The prepared adsorbent had a hydrotalcite-like LDH structure, which was decomposed by calcination and reconstructed upon contacting water. The adsorption process followed pseudo-second-order kinetics. Granulation of the adsorbent for application to chromatographic operation decreased the adsorption rate constant. Adsorption of fluoride ions was high at 7 < pHeq <10 and decreased at higher pHs. The adsorption mechanism involved ion exchange between the fluoride ions in aqueous solution and chloride ions in the adsorbent as well as physisorption via van der Waals forces. The adsorbent was selective towards fluoride ions over nitrate and sulfate ions, although the adsorption of fluoride ions was suppressed in the presence of chloride, carbonate, and phosphate ions. Chromatographic operation using the granulated adsorbent with an alumina-based binder was characterized by slow kinetics, necessitating a low flow rate for the feed solution. The prepared adsorbent was also used to selectively adsorb fluoride ions from simulated wastewater produced by the semiconductor manufacturing process.

Association between composite dietary antioxidant index and erectile dysfunction among American adults: a cross-sectional study

Erectile dysfunction (ED) is closely related to oxidative stress, and antioxidant is a treatment and prevention method for erectile dysfunction. The Compound Dietary Antioxidant Index (CDAI) represents the overall dietary antioxidant intake of the human body. However, the link between CDAI and ED is unclear. The objective of this research was to examine the linkage between CDAI and ED. The research utilized information collected from the National Health and Nutrition Examination Survey (NHANES) spanning the years 2001 to 2004. To assess the association between CDAI and ED, the analysis employed weighted multivariate logistic regression along with weighted restricted cubic splines (RCS). Additionally, subgroup interaction analysis was conducted to confirm the findings. In this investigation, 3184 adults from the U.S., all above the age of 20, were part of the study cohort, with 863 of them identified as having ED. Adjustments for potential confounding variables revealed that the odds ratio (95% confidence interval) of CDAI associating with ED was 0.95 (0.92–0.99; P = 0.01). Besides, compared to the lowest tertile, the highest tertile of CDAI was associated with a lower risk of ED (0.63 [0.46–0.88]; P = 0.01). The application of weighted restricted cubic splines (RCS) analysis delineated a nonlinear inverse relationship between CDAI levels and the probability of ED. Subgroup analysis further demonstrated that the association between CDAI and ED remained consistent across subgroups. This cross-sectional analysis revealed a significant correlation, indicating that elevated levels of CDAI are closely linked with a lower likelihood of ED.

Investigating early childhood education students’ ideas about microorganisms

ABSTRACT Various age groups of students often hold alternative ideas regarding aspects of microorganisms, such as their biological functions, activity and typical habitats. Taking into account that (a) although there are research data on school students’ ideas about microorganisms, there do not seem to be much data on the ideas of university students, and (b) the ideas early childhood education students hold about microorganisms are of particular importance as preschool educators are called to support the building of a proper understanding of microorganisms by preschoolers, we investigated the ideas of 84 early childhood education students about microorganisms, focusing on their perceived locations, beneficial/harmful activities and biological functions. The results reveal a significant number of students associating microorganisms with surfaces, objects we touch and the human body. The prevailing conceptualisation portrays microorganisms as a threat to human health, with the most common harmful activity being the induction of diseases and the most beneficial activity being the stimulation of antibody production that follows the intrusion of microorganisms into the body. Regarding biological functions, there is a limited understanding, with only about one-third of students attributing all essential functions to microorganisms. We discuss relevant literature and explore the potential implications of our findings.

Self-powered strain sensing devices with wireless transmission: DIW-printed conductive hydrogel electrodes featuring stretchable and self-healing properties

With rapid advancements in health and human–computer interaction, wearable electronic skins (e-skins) designed for application on the human body provide a platform for real-time detection of physiological signals. Wearable strain sensors, integral functional units within e-skins, can be integrated with Internet of Things (IoT) technology to broaden the applications for human body monitoring. A significant challenge lies in the reliance of most existing wearable strain sensors on rigid external power supplies, limiting their practical flexibility. In this study, we present an innovative strategy to fabricate glutaraldehyde (GA)-poly(vinyl alcohol) (PVA)/cellulose nanocrystals (CNC)/Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) conductive hydrogels through multiple hydrogen bonding systems. Combining the advantageous rheological properties of the precursor solution and the high specific surface area after freeze–thaw cycling, we have created a self-powered sensing system prepared by large-area printing using direct ink writing (DIW) printing. The resulting conductive hydrogel exhibits commendable mechanical properties (411 KPa), impressive stretchability (580 %), and robust self-healing capabilities (>98.3 %). The strain sensor, derived from the conductive hydrogel, demonstrates a gauge factor (GF) of 2.5 within a stretching range of 0–580 %. Additionally, the resultant supercapacitor displays a peak energy density of 0.131 mWh/cm3 at a power density of 3.6 mW/cm3. Benefiting from its elevated strain response and remarkable power density features, this self-powered strain sensing system enables the real-time monitoring of human joint motion. The incorporation of a 5G transmission module enhances its capabilities for remote data monitoring, thereby contributing to the progress of wireless tracking technologies for self-powered electronic skin.

The Digital Hereafter, or: Nirvana in the Cloud

In the discussion of posthuman encounters, the focus is predominantly on robotics and the cyborg, artificial intelligence, and the implementation of technological elements into the human body. Less often explored is the complementary vision of the uploaded mind as a promise of life extension or even immortality. Nevertheless, there is, by now, quite a body of conceptual explorations, promises, warnings and also popularizations of this idea. The technological options described range from memory transfer to whole brain emulation or simulation, and they raise a multitude of theoretical, technological, philosophical and ethical concerns. Unsurprisingly, the assessment varies from enthusiastic celebration to dystopian nightmares, and the concepts have also been explored controversially in literary works. In my paper I outline the most important arguments and discuss some works of science fiction which explore visions of uploaded minds, most importantly Greg Evans’s Permutation City, Amitav Ghosh’s The Calcutta Chromosome, and Jeanette Winterson’s Frankissstein.

Adverse health effects of exposure to plastic, microplastics and their additives: environmental, legal and policy implications for Israel

BackgroundIsrael is a regional "hotspot" of plastic pollution, with little discussion of potential adverse health effects from exposure to plastic. This review aims to stimulate discussion and drive policy by focusing on these adverse health effects.Main bodyPlastics are synthetic polymers containing additives which can leach from food- and beverage-contact plastic into our food and beverages, and from plastic textiles onto our skin. Plastics persist in the environment for generations, fragmenting into MNPs: Micro (1 micron–5 mm)-Nano (1 nm–1 micron)-Plastic, which contaminate our atmosphere, water, and food chain. MNP can enter the human body through ingestion, inhalation and touch. MNP < 10 microns can cross epithelial barriers in the respiratory and gastrointestinal systems, and fragments < 100 nm can cross intact skin, enabling entry into body tissues. MNP have been found in multiple organs of the human body. Patients with MNP in atheromas of carotid arteries have increased risk of a combined measure of stroke, cardiovascular disease, and death. Toxic additives to plastics include bisphenols, phthalates, and PFAS, endocrine-disrupting chemicals (EDCs) which cause dysregulation of thyroid function, reproduction, and metabolism, including increased risk of obesity, diabetes, endometriosis, cancer, and decreased fertility, sperm count and quality. Fetal exposure to EDCs is associated with increased rates of miscarriages, prematurity and low birth weight. There is likely no safe level of exposure to EDCs, with increasing evidence of trans-generational and epigenetic effects. There are several existing Israeli laws to reduce plastic use and waste. Taxes on single-use plastic (SUP) were recently cancelled. There are many gaps in regulatory standards for food-, beverage- and child- safe plastic. Existing standards are poorly enforced.ConclusionReduction in production and use of plastic, promotion of recycling and reduction of leaching of toxic additives into our food and beverages are essential policy goals. Specific recommendations: Periodic monitoring of MNP in bottled beverages, food, indoor air; Strengthen enforcement of standards for food-, beverage-, and child-safe plastic; Renew tax on SUPs; National ban on SUP at public beaches, nature reserves and parks; Ban products manufactured with MNP; Increase research on sources and health outcomes of exposure to MNP and EDCs.

Mendelian randomization provides causal association between COVID-19 and thyroid cancer: insights from a multi-cancer analysis

Since the onset of the COVID-19 pandemic, the SARS-CoV-2 virus has caused over 600 million confirmed infections and more than 6.8 million deaths worldwide, with ongoing implications for human health. COVID-19 has been extensively documented to have extrapulmonary manifestations due to the widespread expression of necessary ACE2 receptors in the human body. Nevertheless, the association between COVID-19 and cancer risk remains inadequately explored. This study employs Mendelian randomization (MR) methods to examine the causal relationship between genetic variations associated with COVID-19 and the risk of developing cancer. The findings indicate that COVID-19 has negligible impact on most cancer risks. Interestingly, a higher COVID-19 impact is associated with a decreased risk of thyroid cancer. In summary, our findings demonstrate a genetic correlation between COVID-19 and thyroid cancer, contributing to our understanding of the interplay between COVID-19 and cancer risk.

Introduction

In parallel to the evolution of the multivocal critical debate around it, the posthuman has increasingly invaded everyday life over the last 50-odd years. In the 2020s, posthuman encounters are, for large parts of humanity, occurrences in multiple areas of everyday life. The number of artificially created entities, some of which are ever more indistinguishable from their human creators, has multiplied. The human body has become the focal point of enhancements that call hitherto largely unchallenged notions about its humanness into question, from prosthetic joint replacements and the medical procedures enabling them to the promises of genetic engineering and neurotechnology.

Applications of mixture methods in epidemiological studies investigating the health impact of persistent organic pollutants exposures: a scoping review.

Persistent organic pollutants (POPs) are environmental chemicals characterized by long half-lives in nature and human bodies, posing significant health risks. The concept of the exposome, encompassing all lifetime environmental exposures, underscores the importance of studying POP as mixtures rather than in isolation. The increasing body of evidence on the health impacts of POP mixtures necessitates the proper application of statisticalmethods. We aimed to summarize studies on the overall effects of POP mixtures, identify patterns in applications of mixture methods-statistical methods for investigating the association of mixtures-and highlight current challenges in synthesizing epidemiologic evidence of POP mixtures on health effects as illustrated through a case study. We conducted a systematic literature search on PubMed and Embase for epidemiological studies published between January 2011 and April 2023. We included 240 studies that met our eligibility criteria. 126 studies focused on per- and polyfluoroalkyl substances (PFAS) mixtures only, while 40 analyzed three or more classes of POPs in mixture analyses. We identified 23 unique mixture methods used to estimate the overall effects of POP mixtures, with Bayesian Kernel Machine Regression (BKMR), a type of response-surface modeling, being the most common. Additionally, 22.9% of studies used a combination of methods, including response-surface modeling, index modeling, dimension reduction, and latent variable models. The most extensively explored health outcome category was body weight and birth sizes (n = 43), and neurological outcomes (n = 41). In the case study of PFAS mixtures and birth weight, 12 studies showed negative associations, while 4 showed null results, and 2 showed positive associations. This scoping review consolidates the existing literature on the overall effects of POP mixtures using statistical methods. By providing a comprehensive overview, our study illuminates the present landscape of knowledge in this field and underscores the methodological hurdles prevalent in epidemiological studies focused on POP mixtures. Through this analysis, we aim to steer future research directions, fostering a more nuanced comprehension of the intricate dynamics involved in assessing the health effects of POP mixtures. Our work stands as a significant contribution to the ongoing exploration of the chemicalexposome.

Explant analysis of a chromium nitride coated metal-on-metal total wrist replacement: A case study.

Explant analysis can provide important understanding of how artificial joints perform in the human body. The articulating surfaces of the metacarpal head and the radius cup from a chromium nitride coated metal-on-metal Motec wrist implant were analysed. Due to bone resorption and aseptic loosening, the implant was removed after 6 years in the patient, and metallosis was observed during removal. Visually, some areas of the articulating surfaces appeared polished, others were dulled. A chemical composition analysis of the metacarpal head showed that the polished surfaces were chromium rich, implying this surface was the original chromium nitride coating, whereas the dulled surfaces were cobalt rich, indicating the underlying cobalt chromium substrate. In addition, the underlying cobalt chromium substrate was an order of magnitude rougher than the polished surface, indicating the scale of damage to it. It is speculated that the loss of the coating, and the subsequent damage to the underlying substrate due to a third-body wear process, led to osteolysis and the metallosis seen at revision surgery.

A high-performance wearable microneedle sensor based on a carboxylated carbon nanotube-carbon nanotube composite electrode for the simultaneous detection of uric acid and dopamine

Uric acid (UA) and dopamine (DA) are crucial biomarkers in the human body. However, there is limited research on detecting UA or DA in subcutaneous interstitial fluid (SISF), and no studies on their simultaneous detection in SISF. Here, we developed an electrochemical microneedle sensor based on the carboxylated carbon nanotubes/multiwalled carbon nanotubes (CCNT/CNT) composite electrode for the simultaneous detection of UA and DA. Highly carboxylated CCNT was prepared and mixed with CNT and organosilicon-modified acrylic resin to form the CCNT/CNT composite. The carboxyl functional groups of CCNT enhance the electrode’s adsorption of UA and DA, while CNT improves electron conduction. The sensor achieves a wide linear detection range for UA (5–600 μM) with high sensitivity (7.13 μA μM−1 cm−2) and linearity (R2 = 0.994), as well as a wide linear range for DA (2–200 μM) with high sensitivity (13.31 μA μM−1 cm−2) and linearity (R2 = 0.994). The sensor achieved simultaneous detection of DA and UA in artificial interstitial fluid (ISF), with sensitivity and linearity remaining nearly unchanged compared to that in PBS, and is not affected by high levels of ascorbic acid (AA). Finally, the sensor successfully detected changes in UA levels in ISF of subjects before and after alcohol consumption in vivo, demonstrating its practical application capabilities. This study presents a practical strategy for detecting human biomarkers characterized by low cost, easy fabrication and excellent performance of electrode materials, and a well-designed microneedle sensor preparation scheme, making it highly promising for further research extension.

The potency of Monascus purpureus to achieve the transformation from inorganic selenium into organic selenium during the fermentation process

Selenium (Se), as an essential element for the human body, cannot be produced by itself, making Se-rich products research a current hotspot. Microorganisms are common Se-rich carriers and previous experiments mainly focused on yeast and lactic acid bacteria, lacking mold. In this study, the total Se and organic Se content in Monascus purpureus (M. purpureus) were determined by a liquid chromatography-atomic fluorescence spectrometry after fermentation, applying inorganic sodium selenite as exogenous Se. The research results indicated that M. purpureus successfully converted inorganic Se into organic Se, with an organic Se to total Se ratio of 30.50%, 36.14%, 39.94%, 46.18%, and 53.00% at 2, 4, 6, 8, and 10 mg/L sodium selenite, respectively. The proportion of Se-protein (28.04%–47.33%) was highest in organic Se, especially water-soluble Se-protein, followed by Se-polysaccharide (3.80%–5.07%) and Se-nucleic acid (1.84%–3.07%). Furthermore, Se-enriched treatment did not significantly alter the morphology or structure of M. purpureus, while enriching the types and content of volatile components in the fermentation broth. Thus, this study was expected to lay the foundation for the development and utilization of Se-rich M. purpureus products.

Recurrent evolution of small body size and loss of the sword ornament in Northern swordtail fish.

Across the tree of life, species have repeatedly evolved similar phenotypes. While well-studied for ecological traits, there is also evidence for recurrent evolution of sexually selected traits. Swordtail fish (Xiphophorus) are a classic model system for studying sexual selection, and female Xiphophorus exhibit strong mate preferences for large male body size and a range of sexually dimorphic ornaments. Interestingly, sexually selected traits have also been lost multiple times in the genus. However, there has been uncertainty over the number of losses of ornamentation and large body size because phylogenetic relationships between species in this group have historically been controversial, partially due to prevalent gene flow. Here, we use whole-genome sequencing approaches to re-examine phylogenetic relationships within a Xiphophorus clade that varies in the presence and absence of sexually selected traits. Using wild-caught individuals, we determine the phylogenetic placement of a small, unornamented species, X. continens, confirming an additional loss of ornamentation and large body size in the clade. With these revised phylogenetic relationships, we analyze evidence for coevolution between body size and other sexually selected traits using phylogenetic comparative methods. These results provide insights into the evolutionary pressures driving the recurrent loss of suites of sexually selected traits.

Research Progress on the Mechanism of Correlation Between Vitamin D and Thyroid Cancer

Vitamin D is a kind of fat-soluble vitamin, which is mainly involved in the metabolism of calcium and bone in the human body. As a metabolic substance, it also has a certain impact on the cellular microenvironment, and vitamin D also inhibits the proliferation of tumor cells. 25(OH)D is considered the best index to evaluate the vitamin D level in the human body because of its relatively stable characteristics in the circulation. Thyroid cancer is a common malignant tumor that develops from malignant thyroid nodules. A large number of studies have found that the lower the serum 25(OH)D level, the higher the risk of thyroid nodules. A large number of studies have found that the lower the serum 25(OH)D level, the higher the risk of thyroid nodules.

Dynamic pupillometry system

The phenomena of miosis (constriction) and mydriasis (dilation) of the pupil are exhibited in response to varying levels of light intensity cast upon the eye. In general, the size and responsiveness of the human pupil are under the regulatory purview of the nervous system. Consequently, the study of the pupil offers a means to discern potential abnormalities in the human organism, as it permits an assessment of the nervous system’s behavior. However, the comprehension of pupillary dynamics remains incomplete in certain facets, and methodologies for enhancing diagnostic precision continue to evolve, primarily contingent upon current technological equipment advancements. Thus, the imperative lies in the advancement of technologies that meet these research needs, as the scrutiny of pupillary responses holds the capability to detect anomalies within the human body. Hence, the objective of this endeavor is to conduct preliminary trials of a dynamic pupillometry system, designed to both stimulate and capture images of human pupils, facilitating an investigation into their behavioral patterns. The findings elucidate various pupillary parameters and reveal significant alterations in pupillary conduct, thereby contributing to the advancement of research and technologies within the realm of pupillometry. Thus, this study undertakes an innovative exploration into pupillometry, particularly regarding stimuli of varying wavelengths, thereby providing improvements on the diagnostic, prognostic and preventive capacity with heightened reliability, given the pupil’s size and its reactions cannot be manipulated or falsified since they are involuntary.