Carboxyalkylated cullulose nanocrystals for novel applications

Cellulose nanocrystals (CNC), rigid rod-like nanoparticles, are derived from cellulose through acid hydrolysis and are considered as emerging nanomaterials according to their beneficial properties and commercial availability. In this thesis, the use of CNC derivatives in novel applications was explored. To make CNC more suitable for these applications, carboxyalkylation has been carried out to increase the charge density of CNC and induce hairy structure on the surface of CNC. Since the dispersibility of kaolinite particles are very crucial in their end-use applications ranging from cosmetics to drilling, carboxymethylated CNC was used as a dispersant to increase the stability of such suspensions. In the meantime, CNC was produced in different sizes prior to carboxymethylation to analyze the effect of CNC size on its performance as a dispersant. It was observed that the larger the modified CNC, the higher the charge density, and thus, the more the CNC adsorption to kaolinite particles. Hence, with increasing the CNC size, a lower dosage of modified CNC was observed to be required for attaining better kaolinite stability, which would be industrially attractive. Another fundamental discovery of this research study was that the functional groups on the carboxymethylation of CNC was observed to play a more critical role in the settling affinity of the kaolinite particles than the CNC size

Effect of Amperage and Field of View on Detection of Vertical Root Fracture in Teeth with Intracanal Posts

Introduction: This study sought to assess the effects of amperage (mA) and field of view (FOV) on intracanal metal post artifacts and the diagnostic parameters for detection of vertical root fracture (VRF) in teeth with intracanal posts. Methods and Materials: In this diagnostic study, 80 human single-canal teeth were evaluated by cone-beam computed tomography (CBCT). Nickel chrome cast posts were placed into root canals after root canal therapy and canal preparation. In the test group, fracture was induced by an instron machine while no fracture was induced in the control group. Deterministic and probabilistic sensitivity and specificity values at different exposure settings were statistically analyzed using the one-way ANOVA and pairwise comparisons were performed by Tukey’s test. Results: Significant differences were found between the two groups in terms of deterministic (P<0.0001) and probabilistic (P<0.013) sensitivity and deterministic (P<0.037) and probabilistic (P<0.0001) specificity at different FOV and mA combinations. Conclusion: A smaller FOV and lower mA should be preferably used for detection of VRFs in teeth with intracanal posts.Keywords: Amperage; Cone-Beam Computed Tomography; Field of View; Metal Artifact; Vertical Root Fractur

Inequality in household catastrophic health care expenditure in a low-income society of Iran

Background We assessed change in household catastrophic health care expenditures (CHE) and inequality in facing such expenditures in south-west Tehran. Methods A cluster-sampled survey was conducted in 2003 using the World Health Survey questionnaire. We repeated the survey on the same sample in 2008 (635 and 603 households, respectively). We estimated the proportion of households facing CHE using the ‘household's capacity to pay'. We identified the determinants of the household CHE using regression analysis and used the concentration index to measure socio-economic inequality and decompose it into its determinants factors. Results Findings showed that the proportion of household facing CHE had no significant change in this period (12.6% in 2003 vs 11.8% in 2008). The key determinants of CHE for both years were health care utilization and health care insurance status. Socio-economic status was the main contributor to inequality in CHE, while unequal utilization of dentistry and outpatient services had reduced the inequality in CHE between socio-economic groups. Conclusions We observed no significant change in the CHE proportion despite policy interventions aimed at reducing such expenditures. Any solution to the problem of CHE should include interventions aimed at the determinants of CHE. It is essential to increase the depth of social insurance coverage by expanding the basic benefit package and reducing co-payment

Inequality in household catastrophic health care expenditure in a low-income society of Iran

Background We assessed change in household catastrophic health care expenditures (CHE) and inequality in facing such expenditures in south-west Tehran. Methods A cluster-sampled survey was conducted in 2003 using the World Health Survey questionnaire. We repeated the survey on the same sample in 2008 (635 and 603 households, respectively). We estimated the proportion of households facing CHE using the ‘household's capacity to pay'. We identified the determinants of the household CHE using regression analysis and used the concentration index to measure socio-economic inequality and decompose it into its determinants factors. Results Findings showed that the proportion of household facing CHE had no significant change in this period (12.6% in 2003 vs 11.8% in 2008). The key determinants of CHE for both years were health care utilization and health care insurance status. Socio-economic status was the main contributor to inequality in CHE, while unequal utilization of dentistry and outpatient services had reduced the inequality in CHE between socio-economic groups. Conclusions We observed no significant change in the CHE proportion despite policy interventions aimed at reducing such expenditures. Any solution to the problem of CHE should include interventions aimed at the determinants of CHE. It is essential to increase the depth of social insurance coverage by expanding the basic benefit package and reducing co-payment

Effects of cold stratification and chemical treatments on seed germination in four hazelnut cultivars

Propagation of European hazelnut by seed is influenced by some seed treatments. In this investigation, effect of stratification period and some chemicals on seeds of four hazelnut cultivars were studied. GA3 and four months of stratification, each individually resulted in the highest germination percentage at 82.73% and 83.75%, respectively. There were significant differences between cultivars and treatments in terms of germination percentage and rate. The highest germination percentage and rate were observed in the local cultivar Gerd under GA3 treatment at 100 mg/L and also after four months of stratification

In vivo assessment of nanostructured lipid carrier for oral delivery of zerumbone in leukemic mice model

Cancer nanotherapeutics are progressing rapidly with innovative drug delivery systems to replace conventional delivery systems. Although, antitumor activity of zerumbone (ZER) has been reported, there has been no available information of ZER-loaded nanostructured lipid carrier (NLC) affects murine leukemia cells in vivo. In a previous study, ZER was incorporated into NLC by high pressure homogenization (HPH) technique. Physicochemical characterization included particle size, polydipersity index, zeta potential, pH, entrapment efficiency, loading capacity, stability study, and in vitro drug release, as well as physicochemical stability after being autoclaved and stored at 4˚C, 25˚C and 40˚C for 1 month, were examined. In this study, in vivo effects of ZER-NLC on murine leukemia WEHI-3B cells were investigated. The outcomes of histopathology, TEM and TUNEL assays of BALB/c leukemia mice revealed that the number of leukemia cells were significantly (P < 0.05) decreased in spleen tissue after four weeks of oral administration of ZER-NLC. In conclusion, NLC is suggested as a promising carrier for ZER oral delivery

Isolation, purification and evaluation of anticancer principle from Zingiber zerumbet

The Zingiberaceae family is found in tropical and subtropical areas, with approximately 161 species from 18 genera of this family found in Peninsular Malaysia. Zingiber zerumbet (L.) Smith tree belonging to this family is an edible ginger, originating in South-East Asia, and has been cultivated for thousands of years as a spice and for medical purposes. The aim of this study is to isolate the active principle from extracted essential oil of fresh Zingiber Zerumbet rhizomes by steam-hydrodistillation method. In addition, to determine the purity of this active compound using validated reverse phase high performance liquid chromatography (RP-HPLC). Moreover, the antiproliferative effects of this active principal on various human cancerous and noncancerous cell lines at concentrations of 1 to 100 μg/mL were quantified by MTT assay. As a result, colorless zerumbone (ZER) crystals about 1.3 g/kg as an active principal were extracted from the essential oil of fresh Z. Zerumbet rhizomes. The purity of ZER crystals were shown to be (99.96%). Simultaneously, ZER exhibited significant (P < 0.05) inhibitory effects towards various human cancerous cell lines, while not affected noncancerous cell lines. In conclusion, ZER is suggested to be further developed into a safe therapeutic compound for the treatment of various human cancers

The outcomes of head trauma due to road traffic accident in hospitalized elderly patients

Introduction: Head trauma is one of the most important causes of death in trauma centers. In particular, treatment of head injury in the elderly seems more complicated than that of the young and middle aged. This study aimed to identify the outcomes of head trauma due to road traffic accidents (RTAs) in elderly patients. Materials and Methods: In a descriptive-analytical study, records of 294 elderly patients with head trauma due to RTA retrieved from health information system were reviewed using a checklist. The outcomes of patients were evaluated using the Glasgow Outcome Scale. Complete recovery and partial disability were considered as favorable outcomes, whereas severe disability, vegetative state, and death were defined as unfavorable outcomes. Descriptive factors and adjusted coefficients were calculated using SPSS software. Results: Of 294 elderly patients, 77.2 were men. About half of the road accidents had occurred in urban areas (58.8). Less than half of the injured elderly were pedestrian (44.9). The mean Glasgow Coma Scale of patients equaled 13.42 ± 3.29. Unfavorable outcomes were observed only in 20.4 of the patients. There were significant differences in head injury severity between the groups with favorable and unfavorable outcomes (P Conclusion: The results of our study mentioned that most of the elderly who had accidents were pedestrian, most of which occurred in the cities. Moderate and severe head injuries in patients had unfavorable clinical outcome

The COVID-19 vaccination acceptance/hesitancy rate and its determinants among healthcare workers of 91 Countries: A multicenter cross-sectional study.

The aim of this study was to investigate the COVID-19 vaccination acceptance rate and its determinants among healthcare workers in a multicenter study. This was a cross-sectional multi-center survey conducted from February 5 to April 29, 2021. The questionnaire consisted of 26 items in 6 subscales. The English version of the questionnaire was translated into seven languages and distributed through Google Forms using snowball sampling; a colleague in each country was responsible for the forward and backward translation, and also the distribution of the questionnaire. A forward stepwise logistic regression was utilized to explore the variables and questionnaire factors tied to the intention to COVID-19 vaccination. 4630 participants from 91 countries completed the questionnaire. According to the United Nations Development Program 2020, 43.6 % of participants were from low Human Development Index (HDI) regions, 48.3 % high and very high, and 8.1 % from medium. The overall vaccination hesitancy rate was 37 %. Three out of six factors of the questionnaire were significantly related to intention to the vaccination. While 'Perceived benefits of the COVID-19 vaccination' (OR: 3.82, p-value<0.001) and 'Prosocial norms' (OR: 5.18, p-value<0.001) were associated with vaccination acceptance, 'The vaccine safety/cost concerns' with OR: 3.52, p-value<0.001 was tied to vaccination hesitancy. Medical doctors and pharmacists were more willing to take the vaccine in comparison to others. Importantly, HDI with OR: 12.28, 95 % CI: 6.10-24.72 was a strong positive determinant of COVID-19 vaccination acceptance. This study highlighted the vaccination hesitancy rate of 37 % in our sample among HCWs. Increasing awareness regarding vaccination benefits, confronting the misinformation, and strengthening the prosocial norms would be the primary domains for maximizing the vaccination coverage. The study also showed that the HDI is strongly associated with the vaccination acceptance/hesitancy, in a way that those living in low HDI contexts are more hesitant to receive the vaccine

Distinct characteristics and severity of brain magnetic resonance imaging lesions in women and men with multiple sclerosis assessed using verified texture analysis measures

Background and goalIn vivo characterization of brain lesion types in multiple sclerosis (MS) has been an ongoing challenge. Based on verified texture analysis measures from clinical magnetic resonance imaging (MRI), this study aimed to develop a method to identify two extremes of brain MS lesions that were approximately severely demyelinated (sDEM) and highly remyelinated (hREM), and compare them in terms of common clinical variables.MethodTexture analysis used an optimized gray-level co-occurrence matrix (GLCM) method based on FLAIR MRI from 200 relapsing-remitting MS participants. Two top-performing metrics were calculated: texture contrast and dissimilarity. Lesion identification applied a percentile approach according to texture values calculated: ≤ 25 percentile for hREM and ≥75 percentile for sDEM.ResultsThe sDEM had a greater total normalized volume yet smaller average size, and worse MRI texture than hREM. In lesion distribution mapping, the two lesion types appeared to overlap largely in location and were present the most in the corpus callosum and periventricular regions. Further, in sDEM, the normalized volume was greater and in hREM, the average size was smaller in men than women. There were no other significant results in clinical variable-associated analyses.ConclusionPercentile statistics of competitive MRI texture measures may be a promising method for probing select types of brain MS lesion pathology. Associated findings can provide another useful dimension for improved measurement and monitoring of disease activity in MS. The different characteristics of sDEM and hREM between men and women likely adds new information to the literature, deserving further confirmation