Search

The aim of the present paper is to study the effect of multi-recycling on the fracture behavior of high impact polystyrene from disposable cups. After collecting and washing the material, it was subjected to six cycles of recycling. After each cycle, it was subjected to tensile tests to determine the R-curves. The theory of the J-integral contour has been used for the development of a characterization method of the fracture strength appropriate to the case of this non-linear elastoplastic polymer material. To this end, the method of multiple specimens (Single edge notch tension SENT) of thin thickness was used, by introducing cracks of the same lengths to several identical test pieces. The results suggested a slight decrease in crack resistance of recycled high impact polystyrene, especially during the first cycle, demonstrated by a comparison of JIC values related to initiation of crack propagation. The fracture energy absorbed as a function of the cycles suggested a weakening within the material. ABSTRAK: Tujuan kajian ini adalah bagi mengkaji kesan tindak balas pada pelbagai peringkat-kitar semula ke atas kerapuhan polisterin berimpak tinggi pada cawan pakai buang. Selepas mengumpul dan membasuh cawan ini, terdapat enam peringkat kitar semula. Pada setiap peringkat, ianya akan melalui ujian tegangan bagi mendapatkan lengkung-R. Teori kamiran-J kontur telah digunakan bagi mencipta kaedah khas bagi mengkaji kekuatan retakan bersesuaian bagi kes bahan polimer elastoplastik yang tidak-linear. Sehingga kini, kaedah Regangan Tepi Takuk Tunggal (SENT) telah digunakan pada spesimen berketebalan rendah, dengan menghasilkan keretakan sama panjang di permulaan kajian di buat pada pelbagai bahan uji yang serupa. Dapatan kajian menunjukkan rintangan pada retakan telah berkurang sedikit pada polisterin kitar semula berimpak tinggi, terutama pada kitaran pertama, yang ditunjukkan pada nilai JIC pada permukaan rambatan retakan awal. Tenaga kerapuhan yang meresap pada setiap kitaran menunjukkan bahan telah melemah dari dalam.

This work presents an in-depth experimental study aimed at assessing the impact of natural weathering on the behavior of high-density polyethylene (HDPE) bottles. To this end, several analytical techniques were employed, including Fourier transform infrared spectroscopy (FTIR) to examine molecular changes, scanning electron microscopy (SEM) to study morphology, thermogravimetric analysis (TGA) to assess thermal properties, and tensile and compression tests to evaluate mechanical properties. The results obtained reveal significant changes in HDPE exposed to natural weathering. FTIR analysis enabled us to identify that the 1IDPE bottles had been subjected to an oxidation process initiated b) the absorption of solar radiation during natural weathering treatments, while SEM analysis showed the presence of holes resulting from the detachment of material fragments after exposure, TGA analysis confirms the impact of natural exposure time on the decrease in the average molecular weight and chemical degradation of HDPE macromolecules, through a reduction in the initial degradation temperature and the maximum thermodegradation temperature. However, tensile and compressive tests showed a reduction in the mechanical strength of HDPE after exposure to natural conditions, with notable variations depending on environmental conditions, making the material damaged. These results enabled us to calculate the damage caused by three damage laws. These results offer important insights into the mechanisms of HDPE degradation under the influence of natural climatic factors, paving the way for the development of more resistant and durable packaging materials in the face of variable environmental conditions. Highlights * The objective of this study is to analyze and describe the effects of natural weathering on high-density polyethylene bottles. This involves evaluating the deterioration of physicochemical, mechanical, and morphological properties. Additionally, three damage laws aBe employed to assess the extent of damage inflicted by this material. * Analytical techniques were used, including SEM, FT1R, and TGA, tensile and compressive test. KEYWORDS damage, FTIR, HDPE bottles, natural weathering, SEM, TGA, 1 | INTRODUCTION Growing demand in sectors such as packaging, automotive and construction has led to an exponential increase in global plastics consumption since the 1950s. (1,2) Packaging plays an [...]

It is important to study the Behaviour of high-density polyethylene (HDPE) under notch effects as it is widely used in industrial applications (Qi, 2018). However, there are only a few studies on the Behaviour of HDPE with defects, this work aims to study the deformation mechanisms under a tensile test experimentally performed on blank and notched specimens at constant speed and room temperature, and by developing our study by simulating HDPE using commercial software code.

Considering the wide use of high impact polystyrene in different fields, it is important to know its behavior in different environmental conditions. This work is interested in the characterization of the behavior of high impact polystyrene (HIPS) under tensile and bending stress.

Dictation is a traditional technique for both teaching and testing overall language ability and listening comprehension. In a dictation, a passage is read aloud by the teacher and examinees write down what they hear. Due to the peculiar form of dictations, psychometric analysis of dictations is challenging. In a dictation, there is no clear boundary between the items and every word in the text is potentially an item. This makes the analysis of dictations with classical and modern test theories rather difficult. In this study, we suggest a procedure to make dictations analyzable with psychometric models. Our strategy entailed using several independent short passages instead of a single long passage. The number of mistakes in each passage was counted and entered into the analysis. Rasch model analysis was then applied to the passage scores (mistakes). Our findings showed that dictations fit the Rasch model very well and it is possible to measure examinees' ability on an interval scale using dictations.

Archivo histórico de Kipus: Revista Andina de Letras y Estudios Culturales, 2004.

Background Colorectal cancer (CRC) is a widespread malignancy globally, yet effective therapeutic approaches for advanced, metastatic, and chemo-resistant cases remain limited. In this study, we knocked out CRC cell line HCT 116 for two autophagy genes (ATG5 and ATG7), then we conducted a transcriptomic analysis on those isogenic cell lines. which revealed an upregulation of Krϋppel-like factor 3 (KLF3) expression, that was biologically validated. Methods In this study, we performed CRISPR/Cas9 gene editing on HCT 116 followed with transcriptomics analysis on HCT 116 KO cells for ATG5 and ATG7. Various bioinformatics analyses were performed to investigate the KLF3/8 with autophagy and affected functional pathways, and immune genes related to the different types. Validation of expression in different cell lines were done using qPCR and Western blot. Results To further investigate the role of autophagy genes in CRC, we utilized publicly available data and web-based tools. Our analysis showed a marked correlation between KLF3/KLF8 and the expression of autophagy genes in CRC, denoting that its upregulation is likely to be a compensatory mechanism. We also examined the co-expression of autophagy genes and KLF3/KLF8 with multiple markers of epithelial-to-mesenchymal transition (EMT), and significant positive correlations were observed. Moreover, KLF8 expression was upregulated at the mRNA level in the metastatic cell lines LoVo and SK-CO-1, compared to HCT 116. Interestingly, KLF3/KLF8 expression was high in MSS molecular subtype of CRC as shown in HCT 116 cell line knocked in with MLH gene as well as they were negatively correlated with crucial immune-infiltrating cells such as CD8+ cells, indicating their potential as a negative biomarker for response to immunotherapy. Conclusion Our study proposes that a synergistic approach involving the inhibition of KLF8 and autophagy holds a potential therapeutic target for effectively tackling metastatic CRC cells, especially in cases characterized by deficient mismatch repair (MMR).

Summary: Triple-negative breast cancer (TNBC) is characterized by lack of the estrogen (ER) receptor, progesterone receptor (PR), and human epidermal growth factor receptor-2 (HER2), and standard receptor-targeted therapies are ineffective. FOXC1, a transcription factor aberrantly overexpressed in many cancers, drives growth, metastasis, and stem-cell-like properties in TNBC. However, the molecular function of FOXC1 is unknown, partly due to heterogeneity of TNBC. Here, we show that although FOXC1 regulates many cancer hallmarks in TNBC, its function is varied in different cell lines, highlighted by the differential response to CDK4/6 inhibitors upon FOXC1 loss. Despite this functional heterogeneity, we show that FOXC1 regulates key oncogenes and tumor suppressors and identify a set of core FOXC1 peaks conserved across TNBC cell lines. We identify the ER-associated and drug-targetable nuclear receptor NR2F2 as a cofactor of FOXC1. Finally, we show that core FOXC1 targets in TNBC are regulated in parallel by the pioneer factor FOXA1 and the nuclear receptor NR2F2 in ER + breast cancer.

Prostate cancer (PCa) is considered one of the most common cancers worldwide. Despite advances in patient diagnosis, management, and risk stratification, 10%–20% of patients progress to castration-resistant disease. Our previous report highlighted a protective role of Dickkopf-3 (DKK3) in PCa stroma. This role was proposed to be mediated through opposing extracellular matrix protein 1 (ECM-1) and TGF-β signalling activity. However, a detailed analysis of the prognostic value of DKK3, ECM-1 and members of the TGF-β signalling pathway in PCa was not thoroughly investigated. In this study, we explored the prognostic value of DKK3, ECM-1 and TGFB1 using a bioinformatical approach through analysis of large publicly available datasets from The Cancer Genome Atlas Program (TGCA) and Pan-Cancer Atlas databases. Our results showed a significant gradual loss of DKK3 expression with PCa progression (p < 0.0001) associated with increased DNA methylation in its promoter region (p < 1.63E-12). In contrast, patients with metastatic lesions showed significantly higher levels of TGFB1 expression compared to primary tumours (p < 0.00001). Our results also showed a marginal association between more advanced tumour stage presented as positive lymph node involvement and low DKK3 mRNA expression (p = 0.082). However, while ECM1 showed no association with tumour stage (p = 0.773), high TGFB1 expression showed a significant association with more advanced stage presented as advanced T3 stage compared to patients with low TGFB1 mRNA expression (p < 0.001). Interestingly, while ECM1 showed no significant association with patient outcome, patients with high DKK3 mRNA expression showed a significant association with favourable outcomes presented as prolonged disease-specific (p = 0.0266), progression-free survival (p = 0.047) and disease-free (p = 0.05). In contrast, high TGFB1 mRNA expression showed a significant association with poor patient outcomes presented as shortened progression-free (p = 0.00032) and disease-free survival (p = 0.0433). Moreover, DKK3, TGFB1 and ECM1 have acted as immune-associated genes in the PCa tumour microenvironment. In conclusion, our findings showed a distinct prognostic value for this three-gene signature in PCa. While both DKK3 and TGFB1 showed a potential role as a clinical marker for PCa stratification, ECM1 showed no significant association with the majority of clinicopathological parameters, which reduce its clinical significance as a reliable prognostic marker.

The fast development of vehicle technology and the appearance of 5G networks have brought new opportunities as well as challenges for vehicular fog computing. On the one hand, these advances would bring a safer, more efficient, and comfortable car onto our roads; but on the other, they open up huge security and privacy vulnerabilities. Current solutions typically offer inadequate security coverage, rendering vehicular networks susceptible to diverse attacks. We present a first holistic solution that combines entity authentication with privacy preservation in 5G-enabled vehicular fog computing. A novel feature obfuscation involves the vehicle request messages at an early stage and employs advanced cryptographic methods, rendering any potential attacks much more challenging while preventing even a Trusted Authority (TA) from inferring their underlying purpose. This scheme not only maximizes request communication, reduces interaction and computational overhead but also lessens the dependency on TA thus making it more scalable as well as resilient. Theoretical and simulation results show the merits of this protocol in reducing verification latency, and packet loss rate along with computation overheads as well as communication overhead. Experimental results demonstrate the effectiveness of our proposed protocol against existing approaches to provide privacy and security for vehicular communications. The work thus adds to the body of knowledge taking vehicular communication in 5G capable networks a step forward enhancing secured and efficient operation ensuring more secure roads that deliver their contextual alerts setting new standards for safety levels within any existing vehicular network as well.

In the present research, ginger extracted compounds, namely; Gingerol {(1-[4′-hydroxy-3′-methoxyphenyl]-5-hydroxy-3-decanone} (1), Zingerone {(4-(4-Hydroxy-3-methoxyphenyl)-2-butanone)} (2), and Shogoals {(E)-1-(4-Hydroxy-3- methoxyphenyl) dec-4-en-3-one)} (3) have been investigated as SARS-Cov-2 inhibitors. The interaction of extracted compounds with the virus's spikes may restrict the virus's reproduction or give time to the body's immune system to detect viruses, consequently producing appropriate antibodies. Gaussian 09 with a 6-311G (d, p) basis set, UCA FUKUI, MGL implement, DSV, and LigPlus software were utilized. The active sites for adsorption were identified using the total electron density (TED), FUKUI function, and Millikan charges. Furthermore, docking analysis clearly showed that the inhibition of viral replication depends on binding energy (Eb) and ligand efficiency (LE). A docking study revealed that the inhibition ability of the studied compounds on SARS-CoV-2 was in the order of 2 > 3 > 1.

The increase of plastic waste in the marine environment raises several ecological, human, and biological problems. In this work, an accelerated artificial aging study was conducted in seawater after immersing samples of high-density polyethylene bottles for several aging times and at three different temperatures. The deterioration of the mechanical properties of High density polyethylene (HDPE) under different aging conditions was investigated using tensile and compression tests. The absorption of seawater by the samples was analyzed using a gravimetric method and Fourier transform infrared spectrometry (FTIR). Further surface analysis of the samples during accelerated aging was performed using a scanning electron microscope. The results show that HDPE loses its ductility and rigidity. FTIR analysis confirms the increase in crystallinity during aging. KEYWORDS accelerated aging in marine environment, compression tests, crystallinity rate, FTIR, SEM, tensile tests, 1 | INTRODUCTION Pollution of the world's oceans by plastics has been recognized as a serious problem. Improper disposal of plastic waste can lead directly or indirectly to the release [...]

Objectives: The ability of mothers to accurately predict the presence of fever in their children using the tactile method is still controversial. This study evaluated the accuracy of Iraqi mothers’ tactile fever detection in children under 5 during COVID-19 pandemic. Materials and methods: Interviews were conducted with 200 mothers whose children were under the age of 5 years and who assumed they had fever. Each mother was then asked to touch her child’s body for fever evaluation, while an investigator observed them, recorded their responses, and documented the places of palpation. Thereafter, the investigator determined the child’s temperature using a non-contact temple thermometer (NCTT). Statistical analysis was conducted to compare the maternal tactile approach to NCTT and single site to multiple site palpation in terms of sensitivity, specificity, and predictive values. Results: The prevalence of fever in the study sample was 72%, as 144 of the 200 children involved were confirmed to have fever by NCTT. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the maternal tactile method were 96.5%, 62.5%, 86.9%, and 87.5%, respectively. Multiple child body sites were palpated by 42.5% of mothers, whereas 57.5% palpated a single site, with the forehead being the most common palpated site (31%). Multiple site palpation had a significantly lower incorrect temperature assessment rate than single site palpation (3.5% vs. 27%, p = 0.00001). Additionally, the accuracy increased significantly when the mother palpated multiple sites (96.5% vs. 73%). Conclusion: The findings of this study suggest that mothers’ use of tactile assessment is an effective screening tool when assessing their children’s fever; however, mothers’ fears can reduce the accuracy of this method, whereas instructing the mother to palpate multiple body parts can increase its reliability.

تعد الصناعات الدوائية من الصناعات الكيمياوية والاستراتيجية المهمة، والتي تحظى بالدعم والاهتمام من جميع دول العالم كونها تؤثر بشكل مباشر على صحة الإنسان وحياته، يهدف البحث إلى دراسة وتقييم الأداء للشركات الدوائية الكبيرة في القطاع الخاص، بالاعتماد على المنهج الاقتصادي التحليلي. وينقسم البحث على ثلاثة مباحث، تناول المبحث الأول منهجية الدراسة، فيما تناول المبحث الثاني الاطار النظري الخاص بدراسة كفاءة الأداء الاقتصادي والاطار النظري للصناعات الدوائية، وقد ركز المبحث الثالث على نبذة عن الصناعات الدوائية ووقعها في القطاع الخاص وتناول أيضاً تحليل الأداء الاقتصادي للشركات الكبيرة للصناعات الدوائية في القطاع الخاص باستخدام ثلاثة معايير فقط (معيار الإنتاج الجزئية، معيار القيمة المضافة، معيار النمو) بسبب عدم توفر البيانات الكافية للقطاع الخاص، وخلص البحث إلى نتائج عدة أهمها أن الصناعات الدوائية المحلية بحاجة إلى اعادة تأهيل وإن القطاع الدوائي الخاص بحاجة إلى الاستثمار الأجنبي من أجل الحصول على التمويل والتكنولوجيا الحديثة، كما أوصى البحث إلى تنشيط القوانين المنظمة لعمل القطاع الخاص التي يمكن من خلالها أن تشجعه على تعبئة إمكانات وخبراته داخل البلد.