Breathable and waterproof coated textiles

katedra: KTC; přílohy: 1 CD; rozsah: 62Demands for textiles that can impart hydrophobic qualities have increased greatly over the years as their application has become more prevalent in many industries. Their production can be based either from fabric construction or chemical applications such as coatings and laminates. This experimental work focuses on the use of coatings technology to produce cotton materials that would be both water repellent and breathable. It analyses the effects of using different treatments on the cotton materials samples. Finishes include paste and foam coats with Acrylic/Polyutherane compounds, as well as Pretreatment and post treatments with fluorocarbon based compounds. Applications were done using standard coating methods such as knife on roller and air blade techniques. The experiments also accounts for the different porosity values that cotton fabrics have, and how they affect the air and water permeability of the coated materials.Demands for textiles that can impart hydrophobic qualities have increased greatly over the years as their application has become more prevalent in many industries. Their production can be based either from fabric construction or chemical applications such as coatings and laminates. This experimental work focuses on the use of coatings technology to produce cotton materials that would be both water repellent and breathable. It analyses the effects of using different treatments on the cotton materials samples. Finishes include paste and foam coats with Acrylic/Polyutherane compounds, as well as Pretreatment and post treatments with fluorocarbon based compounds. Applications were done using standard coating methods such as knife on roller and air blade techniques. The experiments also accounts for the different porosity values that cotton fabrics have, and how they affect the air and water permeability of the coated materials

A phytochemical and pharmacological investigation of indigenous agathosma species

Faculty of Sciences School of Pharmacy and Pharmacology 0000073k [email protected] part of an investigation of the biological activities of South African plants and due to their extensive traditional use and lack of scientific evidence, a phytochemical and pharmacological investigation was performed on 17 indigenous Agathosma species (19 samples). The chemical composition of the essential oils was determined using gas chromatography coupled to mass spectroscopy (GC-MS). Analysis resulted in the identification of 333 compounds. To evaluate the chemical similarities and differences, cluster analysis was used to assess the essential oil composition of the samples. The results showed qualitative and quantitative differences amongst the taxa. The essential oils of Agathosma hirsuta and A. zwartbergense are particularly rich in citronellal, hence they are tightly clustered in the dendrogram obtained from the cluster analysis. Linalool, myrcene and limonene are the major constituents of both A. capensis (Gamka) and A. capensis (Besemfontein). Qualitative and quantitative differences are noted in the chemical compositions of the leaf oils of Agathosma capensis (Gamka) and A. capensis (Besemfontein). Agathosma arida and A. lanata are united in a single cluster due to the compounds β-pinene, linalool and spathulenol being major components in both species. The presence of 1,8-cineole in large quantities in both Agathosma namaquensis (23.5%) and A. ovalifolia (9.7%), unites them in a single cluster. A wide chemical variability for the essential oils of indigenous Agathosma species has been demonstrated. There was considerable variation in the percentage oil yield of the essential oils. Agathosma hirsuta produced the highest yield (1.15%) whilst A. ovalifolia produced the lowest yield (0.16%). vi Previous studies have revealed that the coumarin and flavonoid components of Agathosma species are responsible for their biological activities. High performance liquid chromatography (HPLC) was used to document the non-volatile composition of Agathosma species and to establish if phenolic patterns were present amongst the species. All species were found to be rich in flavonoids (i.e. flavones and flavonols). Many of the compounds detected were common to most of the species. A pure coumarin, puberulin, was identified in the diethyl ether extract of Agathosma ovata (round-leaf) and detected in the dichloromethane and methanol (1:1) extract of A. namaquensis. Agathosma species have been used traditionally to treat a wide variety of infections. They has been used as a cough remedy, for the treatment of colds and flu, kidney and urinary tract infections, for the treatment of cholera and other stomach ailments. Based on the extensive use and lack of scientific evidence, a study was embarked upon to determine its bioactivity. Using the disc diffusion assay as a preliminary screening and thereafter the minimum inhibitory concentration (MIC) assay, the antimicrobial activity of the essential oils and non-volatile compounds was assessed on two Gram-positive bacteria, Staphylococcus aureus and Bacillus cereus, one Gram-negative bacterium, Klebsiella pneumoniae, and one yeast, Candida albicans. All of the extracts proved to be active against the four pathogens tested with the exception of Agathosma bathii which showed poor activity against Klebsiella pneumoniae (MIC value of 32mg/ml). The extracts exhibited stronger activity against the pathogens as compared to the essential oils. Both the essential oils and extracts exhibited higher activity towards the Gram-positive bacteria than the Gram-negative bacterium, with the extract of Agathosma ovata (round-leaf) displaying the greatest vii activity against Staphylococcus aureus (MIC value of 0.156mg/ml) and Bacillus cereus (MIC value of 0.125mg/ml). The extract of Agathosma parva displayed the greatest activity against Candida albicans and Klebsiella pneumoniae (MIC value of 1.5mg/ml). Amongst the essential oils, Agathosma pungens proved to be the most active against the Gram-positive pathogen, Bacillus cereus (MIC value of 3mg/ml). Agathosma collina was the most active against Candida albicans (MIC value of 3mg/ml) whilst A. zwartbergense proved to be the least active against most of the tested pathogens. The antimicrobial activity of the essential oils may be ascribed to oxygenated constituents, such as 1,8-cineole, linalool and carvacrol. The activity of the extracts may be ascribed to constituents such as flavonoids, coumarins and alkaloids. Due to the availability and accessibility of Agathosma ovata, a seasonal variation study was performed on the chemical composition of the essential oils and how this may impact on the antimicrobial activity. Furthermore, this species has recently been earmarked for commercial development by the flavour and fragrance industry and information on variability is required to establish the harvesting protocol. Ten samples were harvested in total. There was a substantial variation in the oil yield throughout the year, ranging from 0.23% in early Spring to 0.85% in late Autumn. A higher yield was observed during the flowering season as compared to the non-flowering season. Oil yields were low during Summer (0.44%-0.48%) which may have been due to the low oil content in stems and higher proportion of stems after flowering. The proportion of oil-rich green leaves also decreased markedly, hence affecting the yield. Overall the yields were dependant on the season harvested and proportion of plant parts distilled. viii The chemical composition of the essential oils was determined using GC-MS and resulted in the identification of 145 compounds in 10 of the samples. All samples contained a large number of common monoterpenes and had very similar compositions, with minor quantitative variation. Some components common to all samples include: sabinene, p-cymene, β-pinene, α-pinene, α-thujene, myrcene, limonene, linalool and terpinen-4-ol. Sabinene was found to be the most dominant component in all samples, ranging between 25.6% and 44.4%. Myrcene levels dropped sharply between the beginning of Spring and end of Summer, from 14.9% to 1.0%. β-pinene followed a similar trend, peaking during Spring and decreasing during the Summer months. The lowest levels of linalool (4.3%), myrcene (1.0%), β-pinene (3.9%), limonene (1.9%) and sabinene (25.6%), occurred during the Summer months when the temperatures were high. There was a Springtime increase in the levels of β- pinene, terpinen-4-ol, linalool, sabinene, limonene and p-cymene in the non-flowering Agathosma ovata. These changes may have been due to the higher proportion of young leaves during Spring, which may have oil compositions slightly different to those of mature leaves. A rare thiol derivative (tr) that could not be identified was detected in the March sample. Many of the changes were associated with flowering and the results obtained reveal that the chemical composition of the essential oil of Agathosma ovata is subject to seasonal variation. Using the MIC assay, the antimicrobial activity of the essential oils was assessed on two Gram-positive bacteria, Staphylococcus aureus and Bacillus cereus, one Gramnegative bacterium, Klebsiella pneumoniae, and one yeast, Candida albicans. The study demonstrated differences in the potency of antimicrobial activity of the essential oils distilled each month. The Winter samples were more active against Bacillus cereus, Staphylococcus aureus and Klebsiella pneumoniae. Activity in mid Spring ix was greater against Staphylococcus aureus (MIC value of 3mg/ml) and Klebsiella pneumoniae (MIC value of 3mg/ml), whilst activity decreased in Summer. There was a correlation between the concentrations of the active compounds each month and the oils antimicrobial activity. The results reveal that the antimicrobial activity of the essential oil of Agathosma ovata may not depend on the level of one component but rather the ratio of several components. ‘Buchu’ has been used traditionally as a general tonic and medicine. Tonics generally have a high anti-oxidant content in order to promote the overall well-being of the user. The anti-oxidant properties of the essential oils and non-volatile compounds was investigated using the 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and 2, 2'-azinobis(3- ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays. Only the non-volatile compounds exhibited activity. Their activities may be ascribed to the flavonoid components. Most of the species portrayed moderate to poor activity in the DPPH assay with the exception of Agathosma capensis (Gamka) (IC50 value of 24.08 + 4.42μg/ml) and A. pubigera (IC50 value of 35.61 + 0.86μg/ml) which were two of the most active species, although their activities were inferior when compared to vitamin C. The results from the ABTS assay differed from that of the DPPH assay. All extracts showed greater activity in this assay with Agathosma namaquensis (IC50 value of 15.66 ± 4.57μg/ml) and A. capensis (Besemfontein) (IC50 value of 19.84 ± 0.09μg/ml) being the most active species. This may be due to the ABTS assay having an additional reaction system. ‘Buchu’ has been used traditionally as an antipyretic, topically for the treatment of burns and wounds and for the relief of rheumatism, gout and bruises. The antix inflammatory activity of the essential oils and non-volatile compounds was assessed using the 5-lipoxygenase (LOX) assay. Only the essential oils exhibited activity. All proved to be active with the exception of Agathosma stipitata which was UV active and caused interference. This was due to its major compounds neral (39.9%) and geranial (10.1%) which absorbed strongly at 234 nm and hence rendered its spectrophotometric measurement impossible. The essential oil of Agathosma collina displayed the most promising activity (IC50 value of 25.98 ± 1.83μg/ml). It is well known that many herbal medicines can have adverse effects, in which case it is necessary to evaluate the benefit-risk profile. The toxic effects of Agathosma species have been poorly studied and no information is available in this regard. Hence the toxicity profile of the non-volatile compounds and essential oils was assessed on transformed human kidney epithelium (Graham) cells using the microculture tetrazolium (MTT) cellular viability assay. The extracts of Agathosma lanata (IC50 value of 26.17 ± 9.58μg/ml) and A. ovata (round-leaf) (IC50 value of 25.20 ± 6.30μg/ml) proved to be the most toxic, whilst the extracts of Agathosma bathii, A. capensis (Besemfontein), A. betulina, A. crenulata and A. namaquensis did not prove to be toxic at the concentrations tested. Serial dilutions displayed different inhibitions of cell growth and the species proved to be toxic in a dose-dependant manner. The essential oils of all 19 species proved to be much more toxic (IC50 values < 0.0001μg/ml) than a plant-derived compound that is considered relatively safe, namely quinine (IC50 value of 136.06 ± 4.06μg/ml). The toxicities of the essential oils may be due to compounds like methyl chavicol, eugenol, methyl eugenol, pulegone and methyl salicylate whilst the toxicities of the extracts may be due to the alkaloid and coumarin components

The Impact of Traumatic Dental Injuries on the Mental and Social Well-Being of Children and Adolescents: Recommendations for Patient Management

Traumatic injuries to the oral cavity are frequent during childhood, with a documented rate of more than 30% worldwide. These injuries commonly include the skull and mouth, and thus teeth are frequently impacted. Consequently, the individual ends up in pain accompanied by both esthetic and functional issues. The combination of these factors can have a detrimental impact upon normal functioning of a young individual’s lives if the injury is not efficiently treated or managed. This then impacts on the individual’s mental health and their quality of life. Not being able to function as part of a society that they are accustomed to, can cause people to withdraw from society and lose self-confidence. The negative psychological effect of traumatic dental injuries is specific to an individual, and as such each patient should be treated holistically with all factors taken into account. There is a dearth in literature around the full psycho-social impacts of traumatic dental injuries. Dentistry as a clinical field is advancing in treatment of such injuries, but there is still a lack of knowledge and awareness regarding the individual experience and how this could be managed going forward in terms in-chair strategies and the involvement of a multi-disciplinary team

Signs of Child Abuse and Neglect: A Practical Guide for Dental Professionals

Children are the future of society. Society should, in turn protect their dignity and wellbeing by ensuring that they are treated with respect and care. Dental practitioners are often the first health professionals to come into contact with victims of child abuse and neglect, not only to render treatment to abuse victims but also to serve as their first line of defense. As part of a larger human community, dental practitioners are responsible for identifying evidence of intentional harm befalling children and reporting it to law enforcers. Physically abused children predominantly present with injuries to the maxillofacial and oral regions. It is therefore important for dental practitioners to be aware of the intra-oral and extra-oral signs that may be indicative of child abuse and neglect in order to champion the fight against child abuse

Coping mechanisms during the COVID-19 pandemic and lockdown in metropolitan Johannesburg, South Africa: A qualitative study

Background: The COVID-19 pandemic has caused prolonged stress on numerous fronts. While the acute health impacts of psychosocial stress due to the pandemic are well-documented, less is known about the resources and mechanisms utilized to cope in response to stresses during the pandemic and lockdown. Objective: The aim of this study was to identify and describe the coping mechanisms adults utilized in response to the stressors of the COVID-19 pandemic during the 2020 South African lockdown. Methods: This study included adults (n=47: 32 female; 14 male; 1 non-binary) from the greater Johannesburg region in South Africa. Interviews with both closed and open-ended questions were administered to query topics regarding the COVID-19 pandemic. Data were coded and thematically analyzed to identify coping mechanisms and experiences. Results: Adults engaged in a variety of strategies to cope with the pandemic and the ensued lockdown. The ability to access or engage in multiple coping mechanisms were either enhanced or constrained by financial and familial situations. Participants engaged in seven major coping mechanisms: interactions with family and friends, prayer and religion, staying active, financial resources, mindset reframing, natural remedies, and following COVID-19 prevention protocols. Conclusions: Despite the multiple stressors faced during the pandemic and lockdown, participants relied on multiple coping strategies which helped pre-serve their well-being and overcome pandemic-related adversity. The strategies participants engaged in were impacted by access to financial resources and family support. Further research is needed to examine the potential impacts these strategies may have on people\u27s health

A psycho-educational model to facilitate the mental health of street children

Ph.D. (Education)The effects of daily abuse and hardship on the streets lead street children to suffer from poor mental health resulting in them choosing ineffective and self-destructive coping strategies that then impacts their physical health and their overall sense of well-being. Facilitation of the mental health of street children subjected to daily threats to their survival is thus crucially needed. In my previous research, I indicated that street children are more vulnerable to impaired psychological health than any other group of children (Moolla, 2007:65-78; Moolla, Myburgh & Poggenpoel, 2008:597). The results of this research further confirmed that street children experience a vast array of negative feelings during their daily survival activities on the street which impact negatively on their mental and physical health. I also found that negative feelings of fear, abandonment, rejection, sadness, loss of trust, disillusionment and a sense of both hopelessness and uncertainty were experienced by all the street children in the study during their daily activities necessary for their survival. As a psycho-educational facilitator, I am equipped with the skills to provide the facilitation of the mental health of street children subjected to daily abuse and hardship on the streets. Psycho-educational facilitators are highly valuable in providing an integrated healthcare-social-psychological approach when working with vulnerable individuals. To date, they are not being utilized to benefit the community and social health services, places of care and institutions catering for the neglected and abused individuals in our society. The development of a model “Facilitating the mental health of street children” is the primary purpose of this research. The problem of street children suffering from challenges to their mental health due to their daily abuse encountered on the streets, made me realise that street children need urgent facilitation of their mental health. The fact that they made a decision to leave a usually abusive home and family environment for the street shows that street children already possess an inner resilience when it comes to self preservation. However, they frequently end up choosing destructive coping strategies which makes it more difficult for them to utilise their inner resources to enhance their lives. Thus, this model focuses on nurturing this inner resilience present in street children in order to facilitate them toward enhanced mental health. Other important aspects of this research are guidelines and recommendations for psycho-educational facilitators or any healthcare professional with regard to how they should implement the model

The lived experiences of children living on the streets of Hillbrow

Background: The effects of daily abuse and hardship on the streets lead to poor mental health in children living on the streets, resulting in them choosing ineffective and self-destructive coping strategies that impact their physical health and overall sense of wellbeing. The facilitation of the mental health of children living on the streets who are subjected to daily threats to their survival is thus crucial. Objectives: The aim of this research was to explore and describe the lived experiences of children living on the streets of Hillbrow, Johannesburg. Method: The research design was qualitative, exploratory, descriptive and contextual. A purposive sample was selected through a temporary shelter in Johannesburg, Gauteng, South Africa and consisted of 14 male children living on the streets. Data were collected using drawings, in-depth phenomenological interviews and field notes. The central interview opening statement was: ‘Tell me about your life on the street’. Results: The results obtained indicated that children living on the streets are threatened, exploited and exposed to physical, sexual and emotional abuse on a daily basis by the community, the authorities and other street dwellers. This leads to feelings of sadness, fear, anxiety, misery, despair, hopelessness, helplessness and suicide ideation, which in turn lead to drug abuse and criminal activities. In contrast, positive feelings of sympathy for other children living on the streets emerged and these children also displayed perseverance, resilience and a striving for autonomy. Conclusion: Street life exposes children to a variety of experiences, both positive and negative. A striving after autonomy is clearly depicted by these children, who are able to tap into a range of responses, both on- and off-street

Coping strategies employed by public psychiatric healthcare workers during the COVID-19 pandemic in southern Gauteng, South Africa.

Within the context of the novel coronavirus pandemic and new challenges to a resource-constrained public healthcare system, many healthcare workers in South Africa have faced numerous stressors that have compromised their mental health. While the current literature on COVID-19 in South Africa highlights the widespread psychosocial stress experienced by healthcare workers during the pandemic, little is known about the coping strategies utilized to continue service delivery and maintain ones mental health and well-being during this ongoing public health emergency. In this study, we sought to explore the coping strategies used by healthcare workers employed in the public psychiatric care system in southern Gauteng, South Africa during the coronavirus disease (COVID-19) pandemic. Psychiatric healthcare workers (n = 55) employed in three tertiary public hospitals and two specialized psychiatric facilities participated in in-depth interviews between July 2020 and March 2021. We found that coping strategies spanned multi-level and multi-systemic efforts. Intrapersonal, interpersonal, material, and structural coping were mapped across individual, family, and hospital systems. The most commonly utilized coping strategies included positive mindsets and reappraisal, social support systems, and COVID-19 specific protections. Findings also highlighted the contextual and interconnected nature of coping. Healthcare workers applied multiple coping strategies to combat the negative mental health effects of the COVID-19 pandemic. Better understanding these strategies, contexts in which they are employed, and how they interact can be used to develop evidence-based interventions to support healthcare workers experiencing healthcare-related stressors during the COVID-19 pandemic

The lived experiences of tuberculosis survivors during the COVID-19 pandemic and government lockdown in South Africa: a qualitative analysis

Abstract Background Tuberculosis (TB) is a major health concern in South Africa, where prior to COVID-19 it was associated with more deaths than any other infectious disease. The COVID-19 pandemic disrupted gains made in the global response to TB, having a serious impact on the most vulnerable. COVID-19 and TB are both severe respiratory infections, where infection with one places individuals at increased risk for negative health outcomes for the other. Even after completing TB treatment, TB survivors remain economically vulnerable and continue to be negatively affected by TB. Methods This cross-sectional qualitative study, which was part of a larger longitudinal study in South Africa, explored how TB survivors’ experienced the COVID-19 pandemic and government restrictions. Participants were identified through purposive sampling and were recruited and interviewed at a large public hospital in Gauteng. Data were analyzed thematically, using a constructivist research paradigm and both inductive and deductive codebook development. Results Participants (n = 11) were adults (24–74 years of age; more than half male or foreign nationals) who had successfully completed treatment for pulmonary TB in the past two years. Participants were generally found to be physically, socioeconomically, and emotionally vulnerable, with the COVID-19 pandemic exacerbating or causing a recurrence of many of the same stressors they had faced with TB. Coping strategies during COVID similarly mirrored those used during TB diagnosis and treatment, including social support, financial resources, distraction, spirituality, and inner strength. Conclusions Implications and suggestions for future directions include fostering and maintaining a strong network of social support for TB survivors