151 research outputs found

    Tests of Full Scale Brick Veneer Steel Stud Walls to Determine Strength and Rain Penetration Characteristics

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    The design, construction and physical testing of five full scale (2.75 m x 5.2 m) brick veneer rain screen wall specimens are reported. Also, the documentation of the design and fabrication of a new test apparatus and of the development of test procedures are major components of the report. The test program included sequences of air pressure loading stages both with and without simulated rain to establish both the structural and rain penetration performances of the test walls. The test walls included four brick veneer/steel stud specimens and one brick veneer/concrete block specimen. Additional tests were performed on bricks, mortar and masonry assemblages to define relevant characteristics. The design and construction of the wall specimens were consistent with current practices in order to assess the appropriateness of these practices. The major points addressed in the report relate to the vulnerabilities of the wall system to excessive rain penetration and resulting moisture damage. In line with these concerns, the likelihood of veneer cracking, the impact of cracking on structural behaviour and on rain penetration and the importance of cavity compartmentalization were addressed. The conclusions indicated that brick veneer rain screen walls are vulnerable to rain penetration if adequate air tightness in the backup and clean comparted cavities are not provided. Also, it was concluded that veneer cracking is likely under full design loads. It is recommended that the design should address the properties of the brick veneer/backup wall system and that the veneer deflections should be limited to control the size of cracks

    Transient development of gravity waves for two layered fluids

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    The transient gravity waves generated by a harmonically oscillating wave maker immersed in two incompressible fluids, the upper fluid having a free surface, is considered. The resulting linearized initial value problem is solved using the method of generalized functions, and asymptotic analysis for large time and distance are given for the elevation

    Possible protective and curative effects of selenium nanoparticles on testosterone-induced benign prostatic hyperplasia rat model

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    Background: Men over the age of 40 are more likely to develop benign prostatic hyperplasia (BPH). BPH is characterized by proliferation of the prostatic epithelium and stroma. Selenium nanoparticles (SeNPs), is an essential metalloid mineral and antioxidant. In this study, SeNPs were tested for their potential protective and curative impacts on BPH in rats. Materials and methods: 50 male Sprague-Dawley rats were randomly divided into five groups: Group I (Control group); Group II (Orchiectomized group): bilateral orchiectomy was conducted on rats; Group III (BPH group): testosterone (TE) enanthate injection was used to induce BPH; Group IV (Protective group): rats were given SeNP before subjecting rats to BPH; Group V (Curative group): rats were succumbed to BPH, followed by administration of SeNP. Measurement of prostate specific antigen (PSA) and TE in serum was performed and prostates were weighed and prepared for histological, immunohistochemical and ultrastructural examination. Results: In the BPH group, serum TE- and PSA-levels, as well as prostate weight, increased significantly and significant decreases in the protective and curative groups. Reduced acinar lumen, expansion of stroma and epithelial hyperplasia were noticed in the BPH group, which were ameliorated significantly both in protective and curative groups. There was an increase in PCNA immunoreaction in the BPH group and a decrease in both the protective and curative groups. On TEM of BPH group, the nuclei appeared irregular with dilated endoplasmic reticulum, loss of cell boundaries and apical microvilli. The protective group showed more improvement than the curative group. Conclusions: The effects of SeNPs on BPH induced by TE in rats, were both protective and curative, although the protective effects were more pronounced

    Applying an internal transcribed spacer as a single molecular marker to differentiate between Tetraselmis and Chlorella species

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    In the realm of applied phycology, algal physiology, and biochemistry publications, the absence of proper identification and documentation of microalgae is a common concern. This poses a significant challenge for non-specialists who struggle to identify numerous eukaryotic microalgae. However, a promising solution lies in employing an appropriate DNA barcoding technique and establishing comprehensive databases of reference sequences. To address this issue, we conducted a study focusing on the molecular characterization and strain identification of Tetraselmis and Chlorella species, utilizing the internal transcribed spacer (ITS) barcode approach. By analyzing the full nuclear ITS region through the Sanger sequencing approach, we obtained ITS barcodes that were subsequently compared with other ITS sequences of various Tetraselmis and Chlorella species. To ensure the reliability of our identification procedure, we conducted a meticulous comparison of the DNA alignment, constructed a phylogenetic tree, and determined the percentage of identical nucleotides. The findings of our study reveal the significant value of the ITS genomic region as a tool for distinguishing and identifying morphologically similar chlorophyta. Moreover, our results demonstrate that both the ITS1 and ITS2 regions are capable of effectively discriminating isolates from one another; however, ITS2 is preferred due to its greater intraspecific variation. These results underscore the indispensability of employing ITS barcoding in microalgae identification, highlighting the limitations of relying solely on morphological characterization

    Polyamide capsules via soft templating with oil drops—1. Morphological studies of the capsule wall

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    Poly(terephthalamide) microcapsules can be reproducibly and easily prepared by interfacial polycondensation around emulsion droplets in water. Oil drops of cyclohexane/chloroform mixture stabilized with poly(vinyl alcohol) containing terephthaloylchloride serve as soft template. The interfacial polycondensation starts immediately after addition of an amine mixture (hexamethylenediamine/diethylenetriamine). Light and scanning electron microscopy prove the formation of capsules with size distribution in the range from a few up to 100 µm depending on particular composition of the reaction mixture. The morphology of the capsule wall is characterized by precipitated particles. If instead of pure organic solvents a reactive oil phase is used as template, the capsules can serve in subsequent reactions as templates for the synthesis of composite particles. In this way, styrene can be radically polymerized inside the capsule leading to composite capsules. The capsule morphology is determined by the partition of all components between all phases

    Transglutaminase inhibition ameliorates experimental diabetic nephropathy

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    Diabetic nephropathy is characterized by excessive extracellular matrix accumulation resulting in renal scarring and end-stage renal disease. Previous studies have suggested that transglutaminase type 2, by formation of its protein crosslink product epsilon-(gamma-glutamyl)lysine, alters extracellular matrix homeostasis, causing basement membrane thickening and expansion of the mesangium and interstitium. To determine whether transglutaminase inhibition can slow the progression of chronic experimental diabetic nephropathy over an extended treatment period, the inhibitor NTU281 was given to uninephrectomized streptozotocin-induced diabetic rats for up to 8 months. Effective transglutaminase inhibition significantly reversed the increased serum creatinine and albuminuria in the diabetic rats. These improvements were accompanied by a fivefold decrease in glomerulosclerosis and a sixfold reduction in tubulointerstitial scarring. This was associated with reductions in collagen IV accumulation by 4 months, along with reductions in collagens I and III by 8 months. This inhibition also decreased the number of myofibroblasts, suggesting that tissue transglutaminase may play a role in myofibroblast transformation. Our study suggests that transglutaminase inhibition ameliorates the progression of experimental diabetic nephropathy and can be considered for clinical application

    P2X7R mutation disrupts the NLRP3-mediated Th program and predicts poor cardiac allograft outcomes

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    Purinergic receptor-7 (P2X7R) signaling controls Th17 and Th1 generation/differentiation, while NOD-like receptor P3 (NLRP3) acts as a Th2 transcriptional factor. Here, we demonstrated the existence of a P2X7R/NLRP3 pathway in T cells that is dysregulated by a P2X7R intracellular region loss-of-function mutation, leading to NLRP3 displacement and to excessive Th17 generation due to abrogation of the NLRP3-mediated Th2 program. This ultimately resulted in poor outcomes in cardiac-transplanted patients carrying the mutant allele, who showed abnormal Th17 generation. Transient NLRP3 silencing in nonmutant T cells or overexpression in mutant T cells normalized the Th profile. Interestingly, IL-17 blockade reduced Th17 skewing of human T cells in vitro and abrogated the severe allograft vasculopathy and abnormal Th17 generation observed in preclinical models in which P2X7R was genetically deleted. This P2X7R intracellular region mutation thus impaired the modulatory effects of P2X7R on NLRP3 expression and function in T cells and led to NLRP3 dysregulation and Th17 skewing, delineating a high-risk group of cardiac-transplanted patients who may benefit from personalized therapy
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