Additive Manufacturing and Performance of Architectured Cement-Based Materials

There is an increasing interest in hierarchical design and Additive Manufacturing (AM)of cement-based materials. However, the brittle behavior of these materials and the presence of interfaces from the additive manufacturing process represent the current major challenges. Our work focuses on harnessing the heterogeneous interfaces by employing clever designs from bio-inspired Bouligand architectured materials. In this paper, we aim to demonstrate some key mechanisms that can allow brittle hardened cement-based materials to gain flaw-tolerant properties. Mechanisms such as cracktwisting at the interfaces have been previously observed in naturally-occurring orsynthetic composite Bouligand architectures. In this paper, a heterogeneous interface with porous characteristics in 3D-printed solid hardened cement paste (hcp)architectures were characterized. We hypothesize that the presence of heterogeneous interface in 3D-printed hardened cement paste (hcp) elements, in conjunction with clever architectures, promote key damage mechanisms such as interfacial cracking and crack twisting that lead to damage delocalization. This delocalization can be energetically favorable and allow energy dissipation and promote toughening and flaw-tolerant properties. We found that these architectures can enhance the properties from the typical strength-porosity relationship, classically known for brittle hcp materials

Effects of endometriosis on sleep quality of women: Does life style factor make a difference?

Background: This study aimed to compare the lifestyle factors and SQ between women with and without endometriosis. Also in this essay, the influence of food intake, socio-demographic and clinical characteristics on sleep quality of women with endometriosis was determined. Methods: Of the 156 infertile women approached for the study, 78 women had endometriosis and 78 were included in the control group. At first, each participant completed a checklist including questions about demographics, physical activity, reproductive and menstrual status. SQ was assessed by the Pittsburgh Sleep Quality Index (PSQI). Dietary data were collected using a validated 147-item semi-quantitative FFQ. Results: Irregular menstrual status, menorrhagia, dysmenorrhea, pelvic pain, history of abortion, family history of endometriosis were associated with endometriosis risk (P < 0.05). In women with physical activity more than 3 h per week, high consumption of the dairy product, and fruit endometriosis is less common (P < 0.05). The total PSQI score, and the scores for subjective sleep quality, sleep latency, sleep disturbance domains were significantly different between the two groups (P < 0.05). In women with endometriosis, poor SQ was associated with dysmenorrhea, pelvic pain, dyspareunia, physical activity, and low consumption of the dairy product, fruit, and nut (p < 0.05). Conclusion: In endometriosis women, SQ was lower than healthy individuals. Lifestyle factors can effect on SQ of these patients. © 2020 The Author(s)

Comparison of artificial neural network and logistic regression models for prediction of mortality in head trauma based on initial clinical data

BACKGROUND: In recent years, outcome prediction models using artificial neural network and multivariable logistic regression analysis have been developed in many areas of health care research. Both these methods have advantages and disadvantages. In this study we have compared the performance of artificial neural network and multivariable logistic regression models, in prediction of outcomes in head trauma and studied the reproducibility of the findings. METHODS: 1000 Logistic regression and ANN models based on initial clinical data related to the GCS, tracheal intubation status, age, systolic blood pressure, respiratory rate, pulse rate, injury severity score and the outcome of 1271 mainly head injured patients were compared in this study. For each of one thousand pairs of ANN and logistic models, the area under the receiver operating characteristic (ROC) curves, Hosmer-Lemeshow (HL) statistics and accuracy rate were calculated and compared using paired T-tests. RESULTS: ANN significantly outperformed logistic models in both fields of discrimination and calibration but under performed in accuracy. In 77.8% of cases the area under the ROC curves and in 56.4% of cases the HL statistics for the neural network model were superior to that for the logistic model. In 68% of cases the accuracy of the logistic model was superior to the neural network model. CONCLUSIONS: ANN significantly outperformed the logistic models in both fields of discrimination and calibration but lagged behind in accuracy. This study clearly showed that any single comparison between these two models might not reliably represent the true end results. External validation of the designed models, using larger databases with different rates of outcomes is necessary to get an accurate measure of performance outside the development population

Postnatal quality of life in women after normal vaginal delivery and caesarean section

<p>Abstract</p> <p>Background</p> <p>Caesarean section might increase the incidence of surgical interventions and problems resulting from hospitalization and thus affecting quality of life in women after delivery. This study aimed to compare quality of life in women after normal delivery and caesarean section.</p> <p>Methods</p> <p>This was a prospective study. A sample of women with normal delivery and caesarean section from 5 health care centers in Isfahan, Iran were entered into the study. Quality of life was measured using the SF-36 at two points in time (time 1: 6 to 8 weeks after delivery; time 2: 12 to 14 weeks after delivery). Data were analyzed to compare quality of life in the two study groups.</p> <p>Results</p> <p>In all 100 women were interviewed (50 with normal delivery and 50 with caesarean section). Postnatal quality of life in both groups was improved from time1 to time 2. However, comparing the mean scores between the normal and caesarean delivery groups the results showed that in general the normal vaginal delivery group had a better quality of life for almost all subscales in both assessment times. The differences were significant for vitality (mean score 62.9 vs. 54.4 P = 0.03) and mental health (mean score 75.1 vs. 66.7, P = 0.03) at first assessment and for physical functioning (mean score 88.4 vs. 81.5, P = 0.03) at second evaluation. However, comparing the findings within each group the analysis showed that the normal vaginal delivery group improved more on physical health related quality of life while the caesarean section group improved more on mental health related quality of life.</p> <p>Conclusion</p> <p>Although the study did not show a clear cut benefit in favor of either methods of delivery that are normal vaginal delivery or caesarean section, the findings suggest that normal vaginal delivery might lead to a better quality of life especially resulting in a superior physical health. Indeed in the absence of medical indications normal vaginal delivery might be better to be considered as the first priority in term pregnancy.</p

Provenancing Archaeological Wool Textiles from Medieval Northern Europe by Light Stable Isotope Analysis (δ13C, δ15N, δ2H)

We investigate the origin of archaeological wool textiles preserved by anoxic waterlogging from seven medieval archaeological deposits in north-western Europe (c. 700-1600 AD), using geospatial patterning in carbon (δ13C), nitrogen (δ15N) and non-exchangeable hydrogen (δ2H) composition of modern and ancient sheep proteins. δ13C, δ15N and δ2H values from archaeological wool keratin (n = 83) and bone collagen (n = 59) from four sites were interpreted with reference to the composition of modern sheep wool from the same regions. The isotopic composition of wool and bone collagen samples clustered strongly by settlement; inter-regional relationships were largely parallel in modern and ancient samples, though landscape change was also significant. Degradation in archaeological wool samples, examined by elemental and amino acid composition, was greater in samples from Iceland (Reykholt) than in samples from north-east England (York, Newcastle) or northern Germany (Hessens). A nominal assignment approach was used to classify textiles into local/non-local at each site, based on maximal estimates of isotopic variability in modern sheep wool. Light element stable isotope analysis provided new insights into the origins of wool textiles, and demonstrates that isotopic provenancing of keratin preserved in anoxic waterlogged contexts is feasible. We also demonstrate the utility of δ2H analysis to understand the location of origin of archaeological protein samples

Developing criteria for Cesarean Section using the RAND appropriateness method

<p>Abstract</p> <p>Background</p> <p>Cesarean section rates are increasing worldwide, and a rapid increase has been observed in Iran. Disagreement exists between clinicians about when to use cesarean section. We aimed to identify the appropriateness criteria for the use of cesarean section in Iran.</p> <p>Method</p> <p>A consensus development study using a modified version of the RAND Appropriateness Method (RAM). We generated scenarios from valid clinical guidelines and expert opinions. A panel of experts participated in consensus development: first round via mail (12 members), second round face-to-face (9 members). We followed the RAM recommendations for the development of the scenario lists, rating scales, and statistical analyses.</p> <p>Results</p> <p>294 scenarios relevant to cesarean section were identified. 191 scenarios were considered appropriate, of which 125 scenarios were agreed upon. The panel found cesarean inappropriate for 21% of scenarios, and 'equivocal' for 14% of scenarios.</p> <p>Conclusion</p> <p>RAM is useful for identifying stakeholder views in settings with limited resources. The participants' views on appropriateness of certain indications differed with available evidence. A large number of scenarios without agreement may partly explain why it has been difficult to curb the growth in cesarean section rate.</p