Approach for testing the material behavior in roll forming in a small scale

Roll forming of ultra-high strength steels (UHSS) and other high strength alloys is an advanced manufacturing methodology with the ability of cold forming those materials to complex three-dimensional shapes for lightweight structural applications. Due to their high strength, most of these materials have a reduced ductility which excludes conventional sheet forming methods under cold forming conditions. Roll forming is possible due to its low strains and incremental forming characteristic. Recent research investigates the development of high strength nano-structured aluminum sheet and titanium alloys, as well as their behaviour in roll forming with regard to formability, material behaviour and shape defects. The development of new materials is often limited to small scale samples due to the high preparation costs. In contrast, industrial application needs larger scale tests for validation, especially in roll forming where a minimum sheet length is required to feed the sample trough the roll forming machine. This work describes a novel technique for studying roll forming of a short length of experimental material. DP780 steel strips (500mm &ndash; 1300mm length) were welded between two mild steel carrier sheets of similar width and thickness giving an overall strip length of 2m. Roll forming trials were performed and longitudinal edge strain, bow and springback determined on the welded samples and samples formed of full length DP780 strip before and after cut off. The experimental results of this work show that this method gives a reasonable approach for predicting material behavior in roll forming transverse to the rolling direction. In contrast to that significant differences in longitudinal bow were observed between the welded sections and the sections formed of full length DP780 strip; this indicates that the applicability of this method is limited with regard to predicting longitudinal material behavior in roll forming.<br /

Retinal Detachment in Down Syndrome: Characteristics and Surgical Outcomes

Purpose. To determine the functional and anatomic outcomes of rhegmatogenous retinal detachment (RRD) surgery in patients with Down syndrome. Methods. A retrospective chart review was performed of patients with Down syndrome who had undergone surgery for RRD at King Khalid Eye Specialist Hospital between 1995 and 2014. Results. A total of 245 patients with Down syndrome were evaluated during the study period. Eighteen eyes of 15 patients (6.1%) with RRD were identified. Three out of 15 patients (20%) presented with bilateral retinal detachment. All eyes presented with macula off retinal detachment. The retina was successfully reattached in 16/18 (88.8%) eyes after a mean follow-up of 48 months. The final postoperative visual acuity ranged from light perception to 20/125 (median: hand motion) (11/18 eyes). Conclusions. The anatomic success rate of retinal reattachment surgery in patients with Down syndrome is comparable to the general population. Patients with Down syndrome should undergo regular ophthalmic examinations for early diagnosis. Despite late diagnosis and the presence of proliferative vitreoretinopathy (PVR) in some patients, favorable anatomical outcomes can be achieved

Nephroprotective Role of Combined Sitagliptin and Oleuropein in Cisplatin-Induced Acute Kidney Injury: Regulation of SDF-1α/Nrf2/ HO-1 Axis and Autophagy

Background: Accumulating evidence proves that cisplatin, a widely used anticancer, causes acute kidney injury (AKI). Sitagliptin (Sita), a dipeptidyl peptidase-4 (DPP4) inhibitor, is a hypoglycemic agent that can promote tissue angiogenesis and cell survival. However, little is known about the nephroprotective effect of Sita in cisplatin-induced AKI especially its effect on SDF-1α, usually degraded by DPP4. Meanwhile, the olive oil component oleuropein (Ole) activates Nrf2/heme oxygenase-1 (HO-1) axis, which ultimately leads to SDF-1α activation. Herein, we studied the nephroprotective effects of combined Sita and Ole on oxidative stress and autophagy through SDF-1α/Nrf2/ HO-1 axis in cisplatin-induced AKI in rats. Methods: AKI was induced in vivo through single IP injection of cisplatin (7 mg/kg), while Sita (10 mg/kg) and Ole (16 mg/kg) were given separately and in combination for 7 days prior and 5 days after cisplatin injection. AKI was assessed through histopathological examination, measurement of serum creatinine and urea. Also, serum GLP-1, serum and kidney SDF-1α levels were measured by ELISA. LC3-II, P62, HO-1, Nrf2, and caspase-3 were investigated by western blotting. Results: Sita and Ole monotherapy and in combination accelerated kidney recovery as they suppress serum SDF-1α, serum BUN, creatinine and renal histopathological features. Each of Sita and Ole enhanced Nrf2/HO-1axis in renal tissues while only Sita enhanced renal SDF-1α. Sita and Ole monotherapy showed incompetent autophagy where the late steps of autophagy were incomplete. Combined treatment enhanced SDF-1α in kidney tissue which showed recovery through autophagy process. Conclusion: Sita and Ole show promising nephroprotective effects in cisplatin-induced AK

Cytotoxic activity of Thymus capitatus collected from Hail region in Saudi Arabia with mechanistic study via induction of caspase-dependent apoptosis and S-phase arrest

Thymus capitatus is a plant grows in Mediterranean area and some Arab countries such as Saudi Arabia. It possesses numerous medicinal values. Its common name is Zaatar and it belongs to family Lamiaceae Thymus capitatus leaves and stem were collected from Hail region, Saudi Arabia. Then both leaves and stem were extracted with ethanol. This study was performed to evaluate cytotoxic activity of Thymus capitatus leaves and stem ethanolic extract in details. Doxorubicin was used as a standard and the relevant half maximal inhibitory concentration (IC50) values were computed for each cell line by 3-(4,5- diemthylthiazole-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. In addition, further mechanistic study was carried out by using Apoptosis assay to explore cytotoxic activity of plant extract. Both leaves and stems extracts were screened against HepG2, A-549, HCT-116 and   MCF-7 cancer cell lines. It was found that leaves’ extract shows high and moderate cytotoxic activity against both A-549 and HepG2 cancer cell lines, respectively (with IC50 = 13.6 and 21.5 μg/ml, respectively), while stem’s extract exerted moderate cytotoxic activity against A-549 cancer cell lines (with IC50 = 21.38 μg/ml).  Further mechanistic study was carried out on A-549 cells by using apoptosis assay. It showed that leaves’ extract resulted in arrest of S-phase and caused apoptosis through activation of caspase-3, p53 and Bax, in addition to down regulation of Bcl-2

Electrical performance of efficient quad-crescent-shaped Si nanowire solar cell

The electrical characteristics of quad-crescent-shaped silicon nanowire (NW) solar cells (SCs) are numerically analyzed and as a result their performance optimized. The structure discussed consists of four crescents, forming a cavity that permits multiple light scattering with high trapping between the NWs. Additionally, new modes strongly coupled to the incident light are generated along the NWs. As a result, the optical absorption has been increased over a large portion of light wavelengths and hence the power conversion efficiency (PCE) has been improved. The electron–hole (e–h) generation rate in the design reported has been calculated using the 3D finite difference time domain method. Further, the electrical performance of the SC reported has been investigated through the finite element method, using the Lumerical charge software package. In this investigation, the axial and core–shell junctions were analyzed looking at the reported crescent and, as well, conventional NW designs. Additionally, the doping concentration and NW-junction position were studied in this design proposed, as well as the carrier-recombination-and-lifetime effects. This study has revealed that the high back surface field layer used improves the conversion efficiency by ∼ 80%. Moreover, conserving the NW radial shell as a low thickness layer can efficiently reduce the NW sidewall recombination effect. The PCE and short circuit current were determined to be equal to 18.5% and 33.8 mA/cm$^{2}$ for the axial junction proposed. However, the core–shell junction shows figures of 19% and 34.9 mA/cm$^{2}$. The suggested crescent design offers an enhancement of 23% compared to the conventional NW, for both junctions. For a practical surface recombination velocity of 10$^{2}$ cm/s, the PCE of the proposed design, in the axial junction, has been reduced to 16.6%, with a reduction of 11%. However, the core–shell junction achieves PCE of 18.7%, with a slight reduction of 1.6%. Therefore, the optoelectronic performance of the core–shell junction was marginally affected by the NW surface recombination, compared to the axial junction

Electrical performance of efficient quad-crescent-shaped Si nanowire solar cell

The electrical characteristics of quad-crescent-shaped silicon nanowire (NW) solar cells (SCs) are numerically analyzed and as a result their performance optimized. The structure discussed consists of four crescents, forming a cavity that permits multiple light scattering with high trapping between the NWs. Additionally, new modes strongly coupled to the incident light are generated along the NWs. As a result, the optical absorption has been increased over a large portion of light wavelengths and hence the power conversion efficiency (PCE) has been improved. The electron–hole (e–h) generation rate in the design reported has been calculated using the 3D finite difference time domain method. Further, the electrical performance of the SC reported has been investigated through the finite element method, using the Lumerical charge software package. In this investigation, the axial and core–shell junctions were analyzed looking at the reported crescent and, as well, conventional NW designs. Additionally, the doping concentration and NW-junction position were studied in this design proposed, as well as the carrier-recombination-and-lifetime effects. This study has revealed that the high back surface field layer used improves the conversion efficiency by ∼ 80%. Moreover, conserving the NW radial shell as a low thickness layer can efficiently reduce the NW sidewall recombination effect. The PCE and short circuit current were determined to be equal to 18.5% and 33.8 mA/ cm 2 for the axial junction proposed. However, the core–shell junction shows figures of 19% and 34.9 mA/ cm 2. The suggested crescent design offers an enhancement of 23% compared to the conventional NW, for both junctions. For a practical surface recombination velocity of 10 2 cm/s, the PCE of the proposed design, in the axial junction, has been reduced to 16.6%, with a reduction of 11%. However, the core–shell junction achieves PCE of 18.7%, with a slight reduction of 1.6%. Therefore, the optoelectronic performance of the core–shell junction was marginally affected by the NW surface recombination, compared to the axial junction

A Highly Sensitive Assay for Monitoring the Secretory Pathway and ER Stress

Background: The secretory pathway is a critical index of the capacity of cells to incorporate proteins into cellular membranes and secrete proteins into the extracellular space. Importantly it is disrupted in response to stress to the endoplasmic reticulum that can be induced by a variety of factors, including expression of mutant proteins and physiologic stress. Activation of the ER stress response is critical in the etiology of a number of diseases, such as diabetes and neurodegeneration, as well as cancer. We have developed a highly sensitive assay to monitor processing of proteins through the secretory pathway and endoplasmic reticulum (ER) stress in real-time based on the naturally secreted Gaussia luciferase (Gluc). Methodology/Principle Findings: An expression cassette for Gluc was delivered to cells, and its secretion was monitored by measuring luciferase activity in the conditioned medium. Gluc secretion was decreased down to 90% when these cells were treated with drugs that interfere with the secretory pathway at different steps. Fusing Gluc to a fluorescent protein allowed quantitation and visualization of the secretory pathway in real-time. Expression of this reporter protein did not itself elicit an ER stress response in cells; however, Gluc proved very sensitive at sensing this type of stress, which is associated with a temporary decrease in processing of proteins through the secretory pathway. The Gluc secretion assay was over 20,000-fold more sensitive as compared to the secreted alkaline phosphatase (SEAP), a well established assay for monitoring of protein processing and ER stress in mammalian cells. Conclusions/Significance: The Gluc assay provides a fast, quantitative and sensitive technique to monitor the secretory pathway and ER stress and its compatibility with high throughput screening will allow discovery of drugs for treatment of conditions in which the ER stress is generally induced

Associations Between Eight Earth Observation-Derived Climate Variables and Enteropathogen Infection : An Independent Participant Data Meta-Analysis of Surveillance Studies With Broad Spectrum Nucleic Acid Diagnostics

Diarrheal disease, still a major cause of childhood illness, is caused by numerous, diverse infectious microorganisms, which are differentially sensitive to environmental conditions. Enteropathogen-specific impacts of climate remain underexplored. Results from 15 studies that diagnosed enteropathogens in 64,788 stool samples from 20,760 children in 19 countries were combined. Infection status for 10 common enteropathogens-adenovirus, astrovirus, norovirus, rotavirus, sapovirus, Campylobacter, ETEC, Shigella, Cryptosporidium and Giardia-was matched by date with hydrometeorological variables from a global Earth observation dataset-precipitation and runoff volume, humidity, soil moisture, solar radiation, air pressure, temperature, and wind speed. Models were fitted for each pathogen, accounting for lags, nonlinearity, confounders, and threshold effects. Different variables showed complex, non-linear associations with infection risk varying in magnitude and direction depending on pathogen species. Rotavirus infection decreased markedly following increasing 7-day average temperatures-a relative risk of 0.76 (95% confidence interval: 0.69-0.85) above 28 degrees C-while ETEC risk increased by almost half, 1.43 (1.36-1.50), in the 20-35 degrees C range. Risk for all pathogens was highest following soil moistures in the upper range. Humidity was associated with increases in bacterial infections and decreases in most viral infections. Several virus species' risk increased following lower-than-average rainfall, while rotavirus and ETEC increased with heavier runoff. Temperature, soil moisture, and humidity are particularly influential parameters across all enteropathogens, likely impacting pathogen survival outside the host. Precipitation and runoff have divergent associations with different enteric viruses. These effects may engender shifts in the relative burden of diarrhea-causing agents as the global climate changes. Plain Language Summary Diarrheal disease is a big health problem for children. It can be caused by different bugs, which can be caught more easily in certain weather conditions, though not much is understood about this because the climate varies so much from one place to the next. This study combined data from many different countries where diarrhea-causing bugs were diagnosed in children's stool. Satellites recorded what the weather was like on the day each sample was collected. Rotavirus is easiest to catch in cold weather and when water washes over the ground after rain. Dry weather also makes it and other viruses easy to catch. Bacteria spread best when the air is warm and humid, and the soil moist, though one type of E. coli can also be spread in rainwater. Climate change will make dry places drier, wet places wetter and everywhere warmer. This might lead to more diarrhea caused by bacteria and less by viruses in some places, though places with moist soil might see more of every kind of bug.Peer reviewe