End plate connections and their influence on steel and composite structures

The structural members of steel frames are jointed by connections. These connections are neither rigid nor pinned but semi-rigid. The performance of steel structures is highly influenced by the behaviour of connections which is characterized by the moment-rotation curve. This thesis studies the effects of semi-rigid connections on steel and composite steel-concrete frames, in particular the behaviour and influence of end plate connections. The first part of the thesis concerns the performance of unbraced planar steel frames with semi-rigid joints. Several aspects are investigated, concerned mainly with the serviceability limit state. Using the definition given in Eurocode 3 for a rigid connection, it is suggested that the conventional limit for the sway angle should be relaxed by 10% when the rotational behaviour of the joints is included in the analysis. For frames designed by the wind-moment method, it is proposed that deflections based on the assumption of rigid joints should be increased by 50% to allow for the connection flexibility. An approximate method, in which the stiffness of beams are reduced to account for joint flexibility, was found to be sufficiently accurate if deflections based on semi-rigid behaviour were to be calculated. Finally, studies on the ultimate limit state show that the resistance of a joint has significant effect on the collapse load of a frame, compared to the more modest influence of joint flexibility. The second part of the thesis concerns the behaviour of composite connections in braced frames. This part consists of a concise collection of the available experimental data, a description of the test programme conducted by the author, a proposed method for prediction of connection stiffness and studies on redistribution of moments in composite beams. Eleven tests have been carried out on bare steel and composite end plate joints. Their moment-rotation behaviour is recorded and the influence of variables on the joint stiffness is pointed out. These variables are the amount of reinforcement in the concrete slab, the type of steelwork connection and the beam depth. Increase in the amount of reinforcement increases significantly the moment resistance of the composite joint but does not influence its initial stiffness. I % reinforcement with respect to the area of concrete slab is proposed to be used for an efficient design. The increase in the depth of steel section increases the moment resistance and stiffness of composite connection but reduces its rotation,capacity. The effect of semi-rigid composite connections on column stability is also studied and a value of 0.75 is proposed as the effective length factor for columns. The proposed method for prediction of connection behaviour is shown to be in satisfactory agreement with the test results. From the final studies in Part Two formulae are proposed for calculation of the required rotation capacity of composite connections

Validity and feasibility of remote measurement systems for functional movement and posture assessments in people with axial spondylarthritis

Introduction: This study aimed to estimate the criterion validity of functional movement and posture measurement using remote technology systems in people with and without Axial spondylarthritis (axSpA). Methods: Validity and agreement of the remote-technology measurement of functional movement and posture were tested cross-sectionally and compared to a standard clinical measurement by a physiotherapist. The feasibility of remote implementation was tested in a home environment. There were two cohorts of participants: people with axSpA and people without longstanding back pain. In addition, a cost-consequence analysis was performed. Results: Sixty-two participants (31 with axSPA, 53% female, age = 45(SD14), BMI = 26.6(SD4.6) completed the study. In the axSpA group, cervical rotation, lumbar flexion, lumbar side flexion, shoulder flexion, hip abduction, tragus-to-wall and thoracic kyphosis showed a significant moderate to strong correlation; in the non-back pain group, the same measures showed significant correlation ranging from weak to strong. Conclusions: Although not valid for clinical use in its current form, the remote technologies demonstrated moderate to strong correlation and agreement in most functional and postural tests measured in people with AxSA. Testing the CV-aided system in a home environment suggests it is a safe and feasible method. Yet, validity testing in this environment still needs to be performed

Combined chemo-magnetic field-photothermal breast cancer therapy based on porous magnetite nanospheres

The efficacy of different modalities of treating breast cancer is inhibited by several limitations such as off-targeted drug distribution, rapid drug clearance, and drug resistance. To overcome these limitations, we developed Lf-Doxo-PMNSs for combined chemo-MF-PTT. The PMNSs were synthesized by hydrothermal method and their physicochemical properties were examined by FE-SEM, TEM, DLS, TGA, XRD investigations. The cytotoxicity of as-synthesized NPs against 4T1 cells was carried out by MTT and flow cytometry assays. Afterwards, the anti-cancer activities of as-synthesized Lf-Doxo-PMNSs on the tumor status, drug distribution and apoptosis mechanism were evaluated. The anti-cancer assays showed that Lf-Doxo-PMNSs significantly suppressed the cancer cell proliferation and tumor weight by prolonging drug availability and potential drug loading in tumor cells; whereas they showed a minimum cytotoxicity against non-cancerous cells. Likewise, combined chemo-MF-PTT using Lf-Doxo-PMNSs displayed the highest anti-cancer activity followed by combined chemo-PTT and combined chemo-MF therapy based on altering the apoptosis mechanism. Therefore, these results showed that combined chemo-MF-PTT based on Lf-Doxo-PMNSs can be used as a promising therapeutic platform with potential targeted drug delivery and high loading capacity features as well as reducing cancer drug resistance

Prevalence of Cannabis Lifetime Use in Iranian High School and College Students: A Systematic Review, Meta-Analyses,and Meta-Regression

Cannabis is the most widely used substance in the world. This study aimed to estimate the prevalence of cannabis lifetime use (CLU) in high school and college students of Iran and also to determine factors related to changes in prevalence. A systematic review of literature on cannabis use in Iran was conducted according to MOOSE guideline. Domestic scientific databases, PubMed/Medline, ISI Web of Knowledge, and Google Scholar, relevant reference lists, and relevant journals were searched up to April, 2014. Prevalences were calculated using the variance stabilizing double arcsine transformation and confidence intervals (CIs) estimated using the Wilson method. Heterogeneity was assessed by Cochran's Q statistic and I-2 index and causes of heterogeneity were evaluated using meta-regression model. In electronic database search, 4,000 citations were retrieved, producing a total of 33 studies. CLU was reported with a random effects pooled prevalence of 4.0 (95 CI = 3.0 to 5.0). In subgroups of high school and college students, prevalences were 5.0 (95 CI = 3.0 to -7.0) and 2.0 (95 CI = 2.0 to -3.0), respectively. Meta-regression model indicated that prevalence is higher in college students (beta = 0.089, p < .001), male gender (beta = 0.017, p < .001), and is lower in studies with sampling versus census studies (beta = -0.096, p < .001). This study reported that prevalence of CLU in Iranian students are lower than industrialized countries. In addition, gender, level of education, and methods of sampling are highly associated with changes in the prevalence of CLU across provinces

Quality of life in patients with breast cancer before and after diagnosis: an eighteen months follow-up study

<p>Abstract</p> <p>Background</p> <p>Measuring quality of life in breast cancer patients is of importance in assessing treatment outcomes. This study examined the impact of breast cancer diagnosis and its treatment on quality of life of women with breast cancer.</p> <p>Methods</p> <p>This was a prospective study of quality of life in breast cancer patients. Quality of life was measured using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30) and its breast cancer supplementary measure (QLQ-BR23) at three points in time: baseline (pre diagnosis), three months after initial treatment and one year after completion of treatment (in all 18 months follow-up). At baseline the questionnaires were administered to all suspected identified patients while both patients and the interviewer were blind to the final diagnosis. Socio-demographic and clinical data included: age, education, marital status, disease stage and initial treatment. Repeated measure analysis was performed to compare quality of life differences over the time.</p> <p>Results</p> <p>In all, 167 patients diagnosed with breast cancer. The mean age of breast cancer patients was 47.2 (SD = 13.5) years and the vast majority (82.6%) underwent mastectomy. At eighteen months follow-up data for 99 patients were available for analysis. The results showed there were significant differences in patients' functioning and global quality of life at three points in time (P < 0.001). Although there were deteriorations in patients' scores for body image and sexual functioning, there were significant improvements for breast symptoms, systematic therapy side effects and patients' future perspective (P < 0.05).</p> <p>Conclusion</p> <p>The findings suggest that overall breast cancer patients perceived benefit from their cancer treatment in long-term. However, patients reported problems with global quality of life, pain, arm symptoms and body image even after 18 months following their treatments. In addition, most of the functional scores did not improve.</p

Renal Function and Risk Factors of Moderate to Severe Chronic Kidney Disease in Golestan Province, Northeast of Iran

Introduction: The incidence of end-stage renal disease is increasing worldwide. Earlier studies reported high prevalence rates of obesity and hypertension, two major risk factors of chronic kidney disease (CKD), in Golestan Province, Iran. We aimed to investigate prevalence of moderate to severe CKD and its risk factors in the region. Methods: Questionnaire data and blood samples were collected from 3591 participants (≥18 years old) from the general population. Based on serum creatinine levels, glomerular filtration rate (GFR) was estimated. Results: High body mass index (BMI) was common: 35.0 of participants were overweight (BMI 25-29.9) and 24.5 were obese (BMI ≥30). Prevalence of CKD stages 3 to 5 (CKD-S3-5), i.e., GFR &lt;60 mL/min/1.73 m2, was 4.6. The odds ratio (OR) and 95 confidence interval (95 CI) for the risk of CKD-S3-5 associated with every year increase in age was 1.13 (1.11- 1.15). Men were at lower risk of CKD-S3-5 than women (OR = 0.28; 95 CI 0.18-0.45). Obesity (OR = 1.78; 95 CI 1.04-3.05) and self-reported diabetes (OR = 1.70; 95 CI 1.00-2.86), hypertension (OR = 3.16; 95 CI 2.02-4.95), ischemic heart disease (OR = 2.73; 95 CI 1.55-4.81), and myocardial infarction (OR = 2.69; 95 CI 1.14-6.32) were associated with increased risk of CKD-S3-5 in the models adjusted for age and sex. The association persisted for self-reported hypertension even after adjustments for BMI and history of diabetes (OR = 2.85; 95 CI 1.77-4.59). Conclusion: A considerable proportion of inhabitants in Golestan have CKD-S3-5. Screening of individuals with major risk factors of CKD, in order to early detection and treatment of impaired renal function, may be plausible. Further studies on optimal risk prediction of future end-stage renal disease and effectiveness of any screening program are warranted. © 2010 Najafi et al

The global, regional, and national burden of stomach cancer in 195 countries, 1990-2017 : a systematic analysis for the Global Burden of Disease study 2017

Background: Stomach cancer is a major health problem in many countries. Understanding the current burden of stomach cancer and the differential trends across various locations is essential for formulating effective preventive strategies. We report on the incidence, mortality, and disability-adjusted life-years (DALYs) due to stomach cancer in 195 countries and territories from 21 regions between 1990 and 2017. Methods: Estimates from GBD 2017 were used to analyse the incidence, mortality, and DALYs due to stomach cancer at the global, regional, and national levels. The rates were standardised to the GBD world population and reported per 100 000 population as age-standardised incidence rates, age-standardised death rates, and age-standardised DALY rates. All estimates were generated with 95% uncertainty intervals (UIs). Findings: In 2017, more than 1·22 million (95% UI 1·19–1·25) incident cases of stomach cancer occurred worldwide, and nearly 865 000 people (848 000–885 000) died of stomach cancer, contributing to 19·1 million (18·7–19·6) DALYs. The highest age-standardised incidence rates in 2017 were seen in the high-income Asia Pacific (29·5, 28·2–31·0 per 100 000 population) and east Asia (28·6, 27·3–30·0 per 100 000 population) regions, with nearly half of the global incident cases occurring in China. Compared with 1990, in 2017 more than 356 000 more incident cases of stomach cancer were estimated, leading to nearly 96 000 more deaths. Despite the increase in absolute numbers, the worldwide age-standardised rates of stomach cancer (incidence, deaths, and DALYs) have declined since 1990. The drop in the disease burden was associated with improved Socio-demographic Index. Globally, 38·2% (21·1–57·8) of the age-standardised DALYs were attributable to high-sodium diet in both sexes combined, and 24·5% (20·0–28·9) of the age-standardised DALYs were attributable to smoking in males. Interpretation: Our findings provide insight into the changing burden of stomach cancer, which is useful in planning local strategies and monitoring their progress. To this end, specific local strategies should be tailored to each country's risk factor profile. Beyond the current decline in age-standardised incidence and death rates, a decrease in the absolute number of cases and deaths will be possible if the burden in east Asia, where currently almost half of the incident cases and deaths occur, is further reduced. Funding: Bill & Melinda Gates Foundation