An experimental and theoretical investigation on the hyper-viscoelasticity of polyamide 12 produced by selective laser sintering.

Polyamide 12 (PA12) is vastly utilized in many additive manufacturing methods, such as Selective Laser Sintering (SLS), and a better understanding of its mechanical behaviors promotes available knowledge on the behaviors of 3D-printed parts made from this polymer. In this paper, SLS-produced standard tensile specimens are studied under monotonic and cyclic tension tests, as well as stress relaxation experiments, and the obtained force-displacement responses are shown to be consistent with a hyper-viscoelastic material model. This finding is also observed in typical pantographic structures produced by the same manufacturing parameters.

An application of the density standard and scaled-pixel-counting protocol to assess the radiodensity of equine incisor teeth affected by resorption and hypercementosis: preliminary advancement in dental radiography.

Background: Equine Odontoclastic Tooth Resorption and Hypercementosis (EOTRH) syndrome is a dental disease where the radiographic signs may be quantified using radiographic texture features. This study aimed to implement the scaled-pixel-counting protocol to quantify and compare the image structure of teeth and the density standard in order to improve the identification of the radiographic signs of tooth resorption and hypercementosis using the EOTRH syndrome model.

Methods And Results: A detailed examination of the oral cavity was performed in 80 horses and maxillary incisor teeth were evaluated radiographically, including an assessment of the density standard.

Serum testosterone level correlates with left ventricular hypertrophy in older women.

Introduction: Sex hormones may play an important role in age-related cardiac remodeling. However, their impact on cardiac structure and function in females of advanced age still remains unclear. The aim of this study is to evaluate the relationship between sex hormones level and echocardiographic parameters in older women with concomitant cardiovascular diseases.

Hormones and depression in the advanced age.

Introduction: In older people, depression and mental disability are more frequently present than in younger subjects. It is found that depressionis a risk factor for dementia, just as dementia is a risk factor for depression. In turn, both disturbances are known to be influenced by hormones.

Allergy: Involvement of Cap a 7, a New Clinically Relevant Gibberellin-Regulated Protein Cross-Reactive With Cry j 7, the Gibberellin-Regulated Protein From Japanese Cedar Pollen.

The genus belongs to the Solanaceae family. Bell or chili peppers are consumed worldwide, but allergy to is rare. It is involved in the celery-birch-mugwort-spice syndrome and cross-reactivities were reported with latex.

Gonadotropins at Advanced Age - Perhaps They Are Not So Bad? Correlations Between Gonadotropins and Sarcopenia Indicators in Older Adults.

Many hormones fluctuate during the aging process. It has been suggested that gonadotropins, which increase with age, contribute to the occurrence of many diseases and syndromes in older life, such as cardiovascular diseases, obesity, frailty syndrome and osteoporosis. This study aims to assess the relationship between circulating gonadotropins and other hormones potentially contributing to age-related functional decline and sarcopenia indicators in 39 male and 61 female community-dwelling seniors, mean age 80 years.

Some aspects related to the indentation-based viscoelastic modelling of trabecular bone tissue.

Purpose: The aim of this research was to verify to what extent the shape of an indenter tip influences the final form of the constitutive equation for the trabecular bone.

Methods: Trabecular bone was formulated as a non-linear viscoelastic material with Mooney-Rivlin hyperelastic model to describe the purely elastic response of the bone tissue. Tests of the mechanical properties of the trabecular bone, resected from the femoral head of a 56-year-old patient, were carried out with two types of indenter: the spherical tip of a diameter of 200 µm and pyramid Vickers tip with 136° between plane faces.

Comparative analyses of blood flow through mechanical trileaflet and bileaflet aortic valves.

Purpose: The primary aim of the present study was to compare the bileaflet and trileaflet aortic valves' performance during uniform blood flow model and boundary conditions. The secondary aim of the study was to determine the effect of Newtonian/non-Newtonian fluid flow assumption on blood flow directly behind the trileaflet valve.

Methods: The geometrical model of the whole system consist of the left ventricle, fragment of the aorta and mechanical valves.

Optical Spectra of Oligofurans: A Theoretical Approach to the Transition Energies, Reorganization Energies, and the Vibronic Activity.

There is experimental evidence of high vibronic activity that accompanies the allowed transition between the ground state and the lowest electronic singlet excited state of oligofurans that contain two, three, and four furan rings. The absorption and emission spectra of the three lowest oligofurans measured at liquid nitrogen temperature show distinct fine structures that are reproduced using the projection-based model of vibronic coupling (with Dushinsky rotation included) parameterized utilizing either Density Functional Theory (DFT, with several different exchange-correlation functionals) or ab initio (CC2) quantum chemistry calculations. Using as a reference the experimental data concerning the electronic absorption and fluorescence for the eight lowest oligofurans, we first analyzed the performance of the exchange-correlation functionals for the electronic transition energies and the reorganization energies.

Endocrine and metabolic aspects of COVID-19.

The paper presents the theoretical considerations on the role of endocrine and metabolic alterations accompanying COVID-19 infection. These alterations may be presumed on the basis of the following two observations. Firstly, the virus SARS-CoV-2 responsible for the COVID-19 infection uses an important renin-angiotensin system (RAS) element - angiotensin-converting enzyme 2 (ACE2) - as a receptor protein for entry into target cells and, in consequence, disturbs the function of the main (circulating) renin-angiotensin-aldosterone system (RAAS) and of the local renin-angiotensin system localized in different tissues and organs.

Ten-year cardiovascular risk among cancer survivors: The National Health and Nutrition Examination Survey.

Background: Cancer survivors have a higher risk of developing and dying from cardiovascular disease (CVD) compared to the general population. We sought to determine whether 10-year risk of atherosclerotic CVD (ASCVD) is elevated among those with vs. without a cancer history in a nationally representative U.

Possible role of gonadotropin excess in age-related diseases - return to the old hypothesis in the light of current data.

The paper presents the evaluation of a hypothesis assuming that the elevated levels of gonadotropins which occur physiologically in older persons are involved by their direct extra-gonadal action in the pathogenesis of age-related disorders. The data on the possibilities of the direct action of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) and their possible deleterious effects in the brain, bone, cardiovascular system and cancer in older persons are reviewed. A proposal of a new approach to the hormonal prevention treatment of age-related disorders (suppression of gonadotropins by means of gonadotropin releasing hormone analogs) is discussed.

NCL Inhibition Exerts Antineoplastic Effects against Prostate Cancer Cells by Modulating Oncogenic MicroRNAs.

Prostate cancer (PCa) is the most frequently diagnosed cancer in men and second most common cause of cancer-related deaths in the United States. Androgen deprivation therapy (ADT) is only temporarily effective for advanced-stage PCa, as the disease inevitably progresses to castration-resistant prostate cancer (CRPC). The protein nucleolin (NCL) is overexpressed in several types of human tumors where it is also mislocalized to the cell surface.

Immunohistochemical detection of prolactin in clinically non-functioning pituitary adenomas.

Introduction: Approximately one third of pituitary adenomas are manifested neither by specific symptoms of hormone overproduction nor by elevated blood levels of pituitary hormones. However, these tumours, diagnosed before surgical intervention as clinically non-functioning pituitary adenomas (CNFPAs) express in majority different pituitary hormones, as can be revealed by means of immunohistochemical examination. One of the pituitary hormones which may be expressed in CNFPAs is prolactin (PRL) but the clinical and pathological data on this condition are very scarce.

Are physical and mental abilities of older people related to gonadotropins and steroid hormones levels?

Background: Aging is characterized by deep alterations of hormone secretion. In majority, hormone secretion, except gonadotropins, undergoes a pronounced decrease which is thought to contribute to the progression of aging. The recent data indicate that gonadotropin excess may also by itself influence the aging process.

Direct actions of gonadotropins beyond the reproductive system and their role in human aging and neoplasia [Bezpośrednie działanie gonadotropin poza układem rozrodczym i ich rola w starzeniu się i nowotworzeniu u człowieka].

Pituitary hormones folitropin (follicle-stimulating hormone, FSH) and lutropin (luteinising hormone, LH) are known as the key regulators of human reproduction. However, their receptors have been identified also in several organs and tissues beyond the reproductive system, and there is cumulating evidence of their direct extra-gonadal actions. The expression of LH receptors (LHR) was found in the brain and adrenal cortex.

Immunohistochemical demonstration of LH/CG receptors in non-neoplastic human adrenal cortex and adrenocortical tumors.

Introduction: Numerous data indicate that luteinizing hormone and/or chorionic gonadotropin (LH/CG) exert direct actions on the adrenal cortex and are involved in the adrenal pathology. However, the immunohistochemical studies on the expression of LH/CG receptors (LH/CGR) in the human adrenal cortex and in the adrenocortical tumors are scarce.

Material And Methods: Paraffin sections of samples of 6 human non-neoplastic adrenal cortex and 25 adrenocortical tumors were immunostained with anti-LH/CGR polyclonal antibody.

Expression of α-Klotho protein in human thyroid cancers - an immunohistochemical study.

Introduction: The α-Klotho protein was discovered as a gene controlling the process of aging, but further studies indicated that it also plays the role of a tumour suppressor. Although numerous studies were performed on the role of the α-Klotho gene and protein in neoplasia, the data on α-Klotho protein expression in thyroid cancers are very scarce. Our study presents the immunohistochemical investigation of α-Klotho expression in benign and malignant thyroid tumours.

Influence of Cryopreservation on Structural, Chemical, and Immunoenzymatic Properties of Aortic Valve Allografts.

Objectives: The problems in preparing (including cryopreservation) and implanting aortic valve allografts (AVAs) is widely elaborated, but some issues need explanation.

Material And Methods: Twenty AVAs cryopreserved in dimethylsulphoxide/RPMI solution under -160°C for 1-15 years and 3 controls stored at +4°C up to 2 weeks, from 19 male and 4 female donors, aged 20-51, ±30.8 years, were examined using light (LM), digital (DM), and scanning electron microscopy (SEM), energy dispersion X-ray spectroscopy (EDS), and enzyme-linked immunosorbent assay immunoenzymatic tests (PECAM1, CD34).

RANBP9 affects cancer cells response to genotoxic stress and its overexpression is associated with worse response to platinum in NSCLC patients.

Although limited by severe side effects and development of resistance, platinum-based therapies still represent the most common first-line treatment for non-small cell lung cancer (NSCLC). However, a crucial need in the clinical management of NSCLC is represented by the identification of cases sensitive to DNA damage response (DDR)-targeting drugs, such as cisplatin or PARP inhibitors. Here, we provide a molecular rationale for the stratification of NSCLC patients potentially benefitting from platinum compounds based on the expression levels of RANBP9, a recently identified player of the cellular DDR.

New microscale constitutive model of human trabecular bone based on depth sensing indentation technique.

A new constitutive model for human trabecular bone is presented in the present study. As the model is based on indentation tests performed on single trabeculae it is formulated in a microscale. The constitutive law takes into account non-linear viscoelasticity of the tissue.

The influence of the cumulated deformation energy in the measurement by the DSI method on the selected mechanical properties of bone tissues.

Purpose: The goal of the study was to determine the influence of DSI test conditions, i.e., loading/unloading rates, hold time, and the value of the maximum loading force on selected mechanical properties of trabecular bone tissue.

[Dehumanizacja współczesnej medycyny: przyczyny i przeciwdziałanie].

A discussion of causes of dehumanisation in contemporary medicine and possible methods of preventing this situation. The causes can be divided into external, associated with the influence of the environment of civilisation, and internal, which constitute a form of aunwanted side effects" of the rapid progress of civilisation. The latter include reductionist thinking and axiological neutrality typical of natural sciences, increased import_ance of technology, and excessive specialisation combined with poor coordination of diagnostic work-up and treatment or the lack of such coordination.

"Silent" thyrotropin (TSH) expression in acromegaly and clinically non-functioning pituitary adenomas.

Introduction: The pituitary adenomas secreting thyrotropin (TSH) are considered the rarest type of hormonally active pituitary tumour. In spite of that, many cases are described in the literature. On the other hand, the observations of the co-expression of TSH with other pituitary hormones (mostly with growth hormone [GH]) and "silent" expression of TSH in clinically non-functioning pituitary adenomas (CNFPA) are rather scarce.