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Background: Wearing is a prominent problem in friction stir welding. The material flow stress equation is a key factor that decides the accuracy of the simulation of the wearing process. Objective: We aim to propose a material flow stress equation based on material true stress and true strain curve, which takes proper factors into account and leads to good accuracy in numerical simulation of stir tool wear. Methods: The value of the material temperature rise caused by the material deformation heat and the value of the effect caused by the temperature rise on flow stress was calculated, and the effect value was used to modify the material flow stress and the related curve, and then the modified flow stress equation was obtained. On this basis, the equation was used to simulate the stir tool wear, and the simulation results were compared with those results without considering the effect of temperature rise. Results & Discussion: the wear amount of the stir needle when considering the effect of temperature rise is significantly less than that when the effect of temperature rise is not considered. Conclusion: In the simulation of the wear of the stir tool, it is necessary to adopt the modified flow stress equation considering the effect of temperature rise.

Regardless of the fascinating progress of humanity, biotechnology and medicine, the outbreak of the global pandemic of the SARS-CoV-2 virus has shown us that we are just as vulnerable as in previous eras when communicable diseases decimated the world’s population. But the discoveries made so far at the molecular level allow us to connect knowledge interdisciplinary and find solutions and therapeutic strategies where there seems to be no link. It was the previous coronavirus infections that served as a homologous model for finding the connection between the SARS-CoV-2 virus and autophagy. Autophagy, a conserved universal process of all eukaryotic cells responsible for cell survival under stressful circumstances, has been shown to play a significant role in viral invasions. It contributes to both direct and indirect antiviral responses such the elimination of viruses, the presentation of their antigens, and the reduction of inflammatory responses. The autophagy machinery of host cells can, however, be suppressed, evaded, or used by viruses to their benefit. Therefore, autophagy has an ambiguous role in coronavirus-related infections, especially in COVID-19. &nbsp

Introduction. The consequences of acquired hearing loss in adults condition their psychosocial functioning and imply changes in the quality of life related to disorders in social and emotional functioning. Hearing loss is considered a risk factor for reduced psychosocial functioning and self-esteem. Psychosocial well-being and preserved self-esteem imply having a positive self-image and realizing that a person is an important part of the social community in which he/she lives. The paper deals with self-esteem and psychosocial functioning of adults with acquired hearing loss. The aim of this research is to determine the level of self-esteem and the degree of expression of consequences in psychosocial functioning, that is, the connection between the level of self-esteem and the degree of expression of consequences in psychosocial functioning in adults with acquired hearing loss. Methods. The research was conducted on a sample of 60 adult subjects with acquired hearing loss and 60 subjects with normal hearing. The average age of the respondents with hearing loss was 54.1 (SD = 10.84), and the sample consisted mostly of male respondents (56.7%) with moderate hearing loss (25.4%). The Rosenberg Self-Esteem Scale and the questionnaire for the subjective assessment of the hearing condition - the HHIA questionnaire (Hearing Handicap Inventory for Adults) were used as instruments. Results. The results showed that the respondents expressed moderate or average self-esteem and that there was a connection between self-esteem and psychosocial functioning in adults with acquired hearing loss. Conclusion. Future research could be directed more towards examining self-esteem in more detail in more specific domains of psychosocial functioning of adults with acquired hearing loss.

Introduction. In recent years, more and more attention has been paid to the research of factors that can potentially contribute to the development of speech and language impairment. It is believed that the results of these studies can contribute to better planning and implementation of early intervention in the field of speech and language in children. The aim of this research is to determine the influence of risk factors on the appearance of language disorders in children. Methods. A total of 97 children aged four to six who participated in the research were divided into two groups. The first group consisted of 54 respondents with a speech and language impairment, and the second group consisted of 43 respondents with typical language development. In both groups, 70 children with risk factors were found. All children with speech and language impairment had some of the risk factors (diseases of mothers during pregnancy, medication during pregnancy, premature labor, caesarean section, asphyxia, disease of newborns, seizures, third tonsil, shortened frenulum, ear infection), while in the group of children with typical language development, 16 respondents had risk factors. The Global Articulation Test, Vocabulary Test, and Comic Story Test were used to assess speech and language abilities. Data on risk factors were obtained on the basis of a survey for parents, which was constructed for the purposes of this research. Results. The results showed that children with risk factors had significantly worse results on the articulation test and the vocabulary test compared to children without risk factors. The results obtained on the Strip Story test did not show that these two groups differ significantly in terms of the number of words produced, the number of sentences and the grammatical structure of the sentence. Conclusion. In general, the results of this research showed a significant connection between risk factors and speech and language disorder in children.

Introduction. Multiparametric magnetic resonance mammography (mMRM) has an important role in detection, evaluation and follow-up of breast lesions. The aim of this study was to explore whether imaging parameters, in particular ADC, can be used as a biomarker of cell proliferation in breast cancer. Methods. This cohort-study included 67 lesions in 50 female patients who underwent mMRM on a 3T scanner. Percutaneous biopsies and surgical excisions were performed after imaging in period up to 3 weeks. The Ki67 index was assessed microscopically. Seven Ki67 categories were defined: 0–5%, 10–20%, 20–40%, 40–50%, 50–80% and over 80%. Methods of descriptive statistics were used; correlations were determined using Pearson’s correlation test. ROC curve was constructed and analyzed for determination of “cut-off” values for diagnostic potential. Statistical significance was set at p < 0.05. Results. Different subtypes of breast carcinomas were involved: ductal carcinoma (59.9%), lobular carcinoma (17.9%), metastatic carcinoma (10.5%), ductal carcinoma in situ (9%), and tubular carcinoma (3%). It was not possible to determine whether there was significant difference in values of ADC for histological subtypes of breast carcinoma because of small number of samples in some groups. The cut off value of ADC for breast carcinoma was 0.792 (sensitivity 98.6%, specificity 65.7%). There was no significant difference in values of ADC for categories of Ki67. There was no significant correlation between ADC mean and Ki67 for all histological subtypes of breast carcinomas (r = 0.156, p = 0.243). Conclusion. ADC cannot be used as a reliable imaging marker for proliferative activity in breast cancer.

Introduction. In addition to the development of spoken language, typical intellectual abilities, preservation of the senses of hearing and sight, phonological awareness and the ability of graphomotor expression are necessary for mastering the skills of reading and writing. With this in mind, the aim of this research is to determine the level of phonological awareness and the ability of graphomotor expression in children with developmental language disorder (DLD) and children with typical language development (TLD). Methods. The sample consisted of 46 children aged five to seven years, who were divided into two groups based on the status of speech and language abilities. The first group consisted of 23 children with DLD, and the second of 23 children with TLD. The FONT test was used to assess phonological awareness, and the Prediction Test for Dysgraphia was used to assess graphomotor abilities. Results. The results of the research show that children with DLD performed poorly on phonological awareness tasks compared to TLD children. Age proved to be a significant factor in differences in the development of phonological awareness. Achievements on the Prediction Test for Dysgraphia show that children with DLD have almost twice the weaker ability of graphomotor expression compared to TLD children. Furthermore, the research results show that there are significant differences in the level of development of graphomotor skills between children of different ages. Also, no significant difference in achievements on the Prediction Test for Dysgraphia or on the FONT test has been found in relation to gender. Conclusion. Children with developmental language disorder had significantly lower achievements on the phonological awareness test and the Prediction Test for Dysgraphia compared to children with typical language development.