Design of automotive structural components using high strength sheet steels structural strength of cold-formed steel I-beams and hat sections subjected to web crippling load

INTRODUCTION When cold-formed steel beam webs are subjected to partial edge loading, they may fail by web crippling rather than bending of the beam. Web crippling is caused by a highly localized intensity of the load or reaction. Because of the complexity of the web crippling behavior, empirical expressions are presently used for the design of cold-formed steel beams in buildings and automotive structural components to prevent web crippling. 1,2,3. The research on the structural behavior of cold-formed steel beam webs subjected to web crippling has been conducted at Cornell University and the University of Missouri-Rolla (UMR) under the sponsorship of the American Iron and Steel Institute (AISI).4,5 Since 1982, additional work has been performed at the University of Missouri-Rolla, Inland Steel Company, and Ford Motor Company to investigate the web crippling strength of automotive structural components using high strength sheet steels. 6-9 The research findings of the UMR study were summarized in the Eighth Progress Report. 7 In the UMR Fifth and Eighth Progress Reports, it was noted that if the I-beam specimens are subjected to the end one-flange loading without connecting the beam flange to the bearing plate, the failure of all sections used in the pilot tests occured by cross-bending of the flange about the connector location as shown in Fig. 1 instead of the conventional web crippling. This type of failure will be referred to as a flange cross-bending mode of failure in this report. It seems to be dependent primarily on the bend radius, the thickness of the web, the location of connectors and other parameters. Figure 2 shows the failure of an I-beam subjected to end one-flange loading. The tested loads for the specimens having the flange cross-bending type of failure were lower than those caused by the conventional web crippling. The purpose of this brief study reported herein was to review the test results described in Ref. 6 for the flange cross-bending type of failure of cold-formed steel I-beams using high strength sheet steels and to develop some new design criteria, if possible. Because of the limited number of test results, the present investigation can only be treated as a preliminary study of the problem. An extensive experimental work will be needed for the development of general design criteria. Section II contains a review of the experimental research results described in Ref. 6. In Section III, an analytical study of this type of failure mode for cold-formed steel I-beams is presented by using the finite element method. The development of an empirical expression for predicting the ultimate load is discussed in Section IV. Also included in this section is the comparison of test results and predicted values based on the newly developed equations for flange cross-bending failure. In addition to the study of the web crippling strength of I-beams, this report also evaluates the results of 157 beam tests using hat sections. These tests were conducted recently at the Research Laboratories of Inland Steel Company. Section V includes the information on beam specimens 10 and comparisons of the tested and predicted failure loads on the basis of the design recommendations proposed in Ref. 7. Finally, conclusions are drawn in Section VI

Honokiol Eliminates Human Oral Cancer Stem-Like Cells Accompanied with Suppression of Wnt/ β

Honokiol, an active compound of Magnolia officinalis, exerted many anticancer effects on various types of cancer cells. We explored its effects on the elimination of cancer stem-like side population (SP) cells in human oral squamous cell carcinoma SAS cells. The sorted SP cells possessed much higher expression of stemness genes, such as ABCG2, ABCC5, EpCAM, OCT-4, CD133, CD44, and β-catenin, and more clonogenicity as compared with the Non-SP cells. After 48 h of treatment, honokiol dose dependently reduced the proportion of SP from 2.53% to 0.09%. Apoptosis of honokiol-treated SP cells was evidenced by increased annexin V staining and cleaved caspase-3 as well as decreased Survivin and Bcl-2. Mechanistically, honokiol inhibited the CD44 and Wnt/β-catenin signaling of SP cells. The Wnt signaling transducers such as β-catenin and TCF-4 were decreased in honokiol-treated SP cells, while the β-catenin degradation promoting kinase GSK-3α/β was increased. Consistently, the protein levels of β-catenin downstream targets such as c-Myc and Cyclin D1 were also downregulated. Furthermore, the β-catenin-related EMT markers such as Slug and Snail were markedly suppressed by honokiol. Our findings indicate honokiol may be able to eliminate oral cancer stem cells through apoptosis induction, suppression of Wnt/β-catenin signaling, and inhibition of EMT

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Test-retest reliability of the Mini Nutritional Assessment and its relationship with quality of life in patients with stroke.

Background & objectiveMalnutrition is one of commonly issues in patients with stroke. The Mini Nutritional Assessment (MNA) is a widely used measure for assessing nutritional status in patients with stroke. A nutritional measure with acceptable test-retest reliability allows clinicians to consistently assess patients' nutritional status. Knowledge of the relationship between nutritional status and quality of life (QOL) could guide clinicians to improve QOL in patients with stroke more effectively. This study aimed to examine test-retest reliability of the MNA and its relationship with QOL in patients with stroke.MethodsFifty-nine patients participated in the test-retest reliability study and the correlation between the MNA and WHO Quality of Life-BREF (WHOQOL-BREF) study. A repeated-assessments design (1 week apart) was used to examine the test-retest reliability of the MNA.ResultsThe intraclass correlation coefficient for the MNA was 0.91. The minimal detectable change and percentage of minimal detectable change for the MNA were 2.1 and 8.2%, respectively. The MNA was positively associated with the QOL (r = 0.32; p = 0.013). The result of linear regression analysis shows that after controlling for age, sex and activities of daily living functions, only the MNA was significantly associated with the WHOQOL-BREF (r2 = 0.104; p = 0.008).ConclusionsThe MNA has satisfactory test-retest reliability that is useful for repeatedly assessing the nutritional status of patients with stroke. The MDC of the MNA has acceptable random measurement error which is useful for determining whether the change score of a patient is outside the range of random measurement error. Future studies that recruit stroke patients in the acute stage is needed to further examine the relationship between the nutritional status and QOL

Copper-mediated Trimethylsilyl Azide In Amination Of Bromoflavonoids To Synthesize Unique Aminoflavonoids

Aminoflavonoids are unique antioxidants comparing to other abundant flavonoids in nature. Their syntheses and biological activities were scarcely reported. An effectively copper-mediated amination of the corresponding bromoflavonoids to synthesize a series of new aminoflavonoids is described. © 2014 Elsevier Ltd. All rights reserved

Long-term outcomes of surgical treatment for intravascular leiomyomatosis

Background: Intravascular leiomyomatosis (IVL) is relatively rare. The optimal surgical method and long-term outcomes are not completely understood. Methods: Medical records between 2007 and 2017 in our hospital were analyzed to identify IVL cases with surgical intervention. Their medical records, operative details, and follow-up were collected by chart review and telephone communication. Results: Eight patients with IVL were included in the study, accounting for 0.26% of all uterine leiomyoma cases. Primary IVL was confined to pelvic cavity in three patients, extended to the inferior vena cava (IVC) below renal vein in one, reached IVC and right atrium in three, and reached main pulmonary artery in one. One-stage operation was performed for seven patients. Cardiopulmonary bypass was done in four patients, and aortic cross-clamp and temporary circulatory arrest was performed in two patients. None of the four patients with intrapulmonary tumors received concomitant pulmonary tumor resection. There was no operative mortality and four morbidities, including ureter injury (2), bladder injury (1), and femoral vein thrombosis (1). During follow-up, two patients exhibited local recurrence of the tumor in the pelvis, and one patient had rapidly growing intrapulmonary tumor three months post-operatively. Intrapulmonary tumors in the other three patients remained stationary at 6, 84, and 120 months post-operatively. Conclusion: One-stage operation to completely remove IVL is feasible and with good long-term outcomes, which is recommended if the patient can tolerate the operation. Concomitant intrapulmonary tumors can be followed up watchfully except when associated with pleural effusion or the pathology indicating trend of increasing malignancy. Keywords: Intravascular leiomyomatosis, Intracardiac leiomyomatosis, Cardiac tumor, Surgery, Cardiopulmonary bypass, Follow-u

Are Risk Factors for Postoperative Significant Hemorrhage following Total Knee Arthroplasty Potentially Modifiable? A Retrospective Cohort Study

Total knee arthroplasty (TKA) is the treatment of choice for end-stage osteoarthritis (OA) of the knee, because it alleviates pain and restores function of the knee. However, TKA-associated hemorrhage and subsequent anemia remain a concern. Most previous studies have defined meaningful postoperative bleeding as blood loss > 500 mL or hemoglobin (Hb) drop > 20 g/L. Therefore, we defined significant hemorrhage as a postoperative Hb drop more than 20 g/L in this study, and we investigated possible risk factors related to significant hemorrhage in TKA and whether these risk factors are modifiable. This retrospective study was conducted through a comprehensive review of the perioperative records of patients with OA of the knee who underwent TKA between January 2009 and December 2015 at our hospital. Patients were allocated into two groups: patients in Group A had their Hb drop ≤ 20 g/L; patients in Group B had their Hb drop > 20 g/L. Factors analyzed included sex, age, body mass index (BMI), the American Society of Anesthesiologists (ASA) classification, comorbidities, preoperative platelet count, use of tranexamic acid (TXA), operation time, and type of anesthesia. A total of 3350 patients met the criteria for analysis, with 1782 patients allocated to Group A and 1568 patients to Group B. Five independent risk factors for significant hemorrhage were identified: male sex (odds ratio(OR), 1.29; 95% confidence interval(CI), 1.08–1.53; p = 0.005), age (OR, 1.02; 95% CI, 1.01–1.03; p = 0.001), use of TXA (OR, 0.39; 95% CI, 0.34–0.45; p p = 0.004), and preoperative platelet count (OR, 0.96; 95% CI, 0.93–0.98; p = 0.001). Of these identified risk factors, preoperative platelet count, use of TXA, and spinal anesthesia are modifiable. These potentially modifiable risk factors need to be taken into consideration when making both the perioperative care and anesthesia plan by surgeons and anesthesiologists, especially in patients at risk of significant hemorrhage

Using Fractal Dimension Analysis with the Desikan–Killiany Atlas to Assess the Effects of Normal Aging on Subregional Cortex Alterations in Adulthood

Normal aging is associated with functional and structural alterations in the human brain. The effects of normal aging and gender on morphological changes in specific regions of the brain are unknown. The fractal dimension (FD) can be a quantitative measure of cerebral folding. In this study, we used 3D-FD analysis with the Desikan–Killiany (DK) atlas to assess subregional morphological changes in adulthood. A total of 258 participants (112 women and 146 men) aged 30–85 years participated in this study. Participants in the middle-age group exhibited a decreased FD in the lateral frontal lobes, which then spread to the temporal and parietal lobes. Men exhibited an earlier and more significant decrease in FD values, mainly in the right frontal and left parietal lobes. Men exhibited more of a decrease in FD values in the subregions on the left than those in the right, whereas women exhibited more of a decrease in the lateral subregions. Older men were at a higher risk of developing mild cognitive impairment (MCI) and exhibited age-related memory decline earlier than women. Our FD analysis using the DK atlas-based prediagnosis may provide a suitable tool for assessing normal aging and neurodegeneration between groups or in individual patients