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2021 ◽  
Vol 14 (2) ◽  
pp. 5-12
Author(s):  
Yahia Y.k. ◽  
Khalid K.K.

Current work was conducted to investigate the histological architecture of the uterine tube and uterus during the period of late pregnancy in rabbits. Twelve adult local breed rabbits were used. The samples from different parts of the uterine tube were prepared for histological study after staining with H&E, Masson’s trichrome and combine Alcian blue (pH2.5)-PAS. The pre ampulla was a narrow tube and its tunica mucosa had slightly long simple mucosal folds lined by pseudostratified columnar epithelium, the ampulla had a wide lumen and its tunica mucosa displayed several highly tall branched mucosal folds with few short simple folds while the isthmus was the narrowest region and its tunica mucosa displayed few of tall and short simple mucosal folds. The mucosa of three parts of the uterine tube was lined by pseudostratified columnar epithelium which is composed of three types of cells: mucous secretory cells, non-secretory cells and basal cells, the mucous secretory cells were the predominant type and revealed secretory activities. The lamina propria-submucosa of the uterine tube was composed of cellular connective tissue and tunica muscularis. The uterus had a very thick wall with well-recognized endometrium and myometrium, the endometrium was composed of many-branched and simple endometrial folds that were covered by multinucleated syncytial cells and simple cuboidal epithelial cells. Lamina propria was composed of loose connective tissue had scattered groups of well growing simple uterine glands that showed secretory activities. The current result showed that the uterus during the late period of pregnancy was differed from those of non-pregnant rabbits, while the uterine tube at late pregnancy has a structure that appeared prepared for the next physiological period.


2021 ◽  
Vol 2021 ◽  
pp. 1-23
Author(s):  
Yawei Duan ◽  
Mi Zhao ◽  
Jingqi Huang ◽  
Huifang Li ◽  
Xiuli Du

An analytical solution for the seismic-induced thrust and moment of the circular tunnel in half-space under obliquely incident P waves is developed in this study, which is the superposition of the solution for deep tunnels under incident and reflected P waves and the reflected SV waves. To consider tangential contact stiffness at the ground-tunnel interface, a spring-type stiffness coefficient is introduced into the force-displacement relationship. Moreover, the tunnel lining is treated as the thick-wall cylinder, providing more precise forecasts than beam or shell models used in previous analytical solution, especially for tunnels with thick lining. The reliability of the proposed analytical solution is assessed by comparing with the dynamic numerical results. Based on the proposed analytical solution, parametrical studies are conducted to investigate the effect of some critical factors on the tunnel’s seismic response, including the incident angles, the tangential contact stiffness at the ground-tunnel interface, and the relative stiffness between the ground and the tunnel. The results demonstrate that the proposed analytical solution performs well and can be adopted to predict the internal forces of circular tunnels under obliquely incident P waves in seismic design.


Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4081
Author(s):  
Ion Sandu ◽  
Claudiu Teodor Fleaca ◽  
Florian Dumitrache ◽  
Bogdan Alexandru Sava ◽  
Iuliana Urzica ◽  
...  

A polyester fabric with rectangular openings was used as a sacrificial template for the guiding of a sub-micron sphere (polystyrene (PS) and silica) aqueous colloid self-assembly process during evaporation as a patterned colloidal crystal (PCC). This simple process is also a robust one, being less sensitive to external parameters (ambient pressure, temperature, humidity, vibrations). The most interesting feature of the concave-shape-pattern unit cell (350 μm × 400 μm × 3 μm) of this crystal is the presence of triangular prisms at its border, each prism having a one-dimensional sphere array at its top edge. The high-quality ordered single layer found inside of each unit cell presents the super-prism effect and left-handed behavior. Wider yet elongated deposits with ordered walls and disordered top surfaces were formed under the fabric knots. Rectangular patterning was obtained even for 20 μm PS spheres. Polyester fabrics with other opening geometries and sizes (~300–1000 μm) or with higher fiber elasticity also allowed the formation of similar PCCs, some having curved prismatic walls. A higher colloid concentration (10–20%) induces the formation of thicker walls with fiber-negative replica morphology. Additionally, thick-wall PCCs (~100 μm) with semi-cylindrical morphology were obtained using SiO2 sub-microspheres and a wavy fabric. The colloidal pattern was used as a lithographic mask for natural lithography and as a template for the synthesis of triangular-prism-shaped inverted opals.


Author(s):  
Yong Pang ◽  
Tao Zhang ◽  
Hongyu Wei ◽  
Ting Zeng ◽  
Yinliang Zhang ◽  
...  
Keyword(s):  

Author(s):  
Peng Fan ◽  
Yuchun Kuang ◽  
Bo Yang

Compressed packer rubber is large deformation material, which endures biaxial contact friction between oil-pipe and casing-pipe in sitting and sealing process. Large-deformation theory analysis of rubber brings huge difficulties to solve, this is due to the material, geometry and contact non-linearity should be considered. In this article, the deformation of compressed packer rubber tube (CPRT) is divided into free deformation, unidirectional and bidirectional constrained deformations. Based on the theory of thick-wall-cylinder and the linear constitutive of rubber material segment, the CPRT mathematical model in different deformation processes is established and the influences of axial load, axial height of CPRT and contact friction coefficient of casing inner wall etc are considered. Based on incremental calculated approach, the mathematical model is solved. By comparing the results of the theoretical model with the results of finite element method and experimental results, it is found that the theoretical maximum contact stress is more conservative than the FEM and experimental solutions, so the sealing reliability of packer effectively predicted under the premise of allowable contact stress and the theoretical results can provide a lower limit reference value for the contact stress of the packer in the actual seal process. Meanwhile, the deviation of contact stress in FEM and theoretical value at z150 height of CPRT is among 1.13%∼4.90%, which can predict the contact stress in the compressed area near the stress concentration upper end-face of CPRT under the low friction factor, the results provide a reference for the compressed packer design.


Plant Disease ◽  
2021 ◽  
Author(s):  
Lin Chang ◽  
Kang Liu ◽  
Liang-gui Wang ◽  
Xiu-lian Yang ◽  
Hui Sun

Chinese catalpa, Catalpa bungei C.A. Mey is native to China and has been widely cultivated as an important tree species for timber and ornamental purposes (Tao et al. 2019). The properties and high durability of the wood can resist the damage caused by microorganisms and insects (Xiao Y et al. 2019). In September 2020, stem cankers were observed in 5-year-old and 3-year-old C. bungei in a pilot experiment field covering 16-hectare area in Shuyang city (Jiangsu province, China) and in a nursery in Binhai city (Jiangsu Province, China), respectively. The disease incidence in both locations was about 1% to 3%. The typical disease symptoms include small to large, dark-brown and irregular-sunken canker around and along the stem under 2 meters from the stem base. The phloem and xylem of the symptomatic stem were dark brown and the xylem had larger necrosis than the phloem. The cross section of the diseased stem was partially died. The symptomatic stem were collected in both locations for pathogen isolation. In total, seven purified isolates from the diseased samples were obtained using potato dextrose agar (PDA) following standard isolation protocol (Huang et al. 2019). In order to determine the pathogenicity, 3-year-old Chinese catalpa seedlings were artificially inoculated with each of the seven isolates in April 2021. After removing the bark of the stem by a sterilized punch (diameter 6mm), an agar plug (diameter 6mm) pre-colonized by the isolate was inoculated to the stem and the inoculation point was sealed with parafilm. The agar plug without pre-colonization was used as control. Six tree seedlings were inoculated for each isolate. Ten days after inoculation, only the treatment with isolate QS.1 showed obvious discoloration around the inoculation point. One month after inoculation, the canker around the inoculation point was formed (3.4 cm ± 1.0 cm) and spread to the xylem, similar to the symptoms observed in the field. Isolate QS.1 was re-isolated successfully from the inoculated stem based on morphological characters, confirming the Koch's postulates and QS.1 as the causal pathogen. The isolate QS.1 formed white colonies with abundant aerial mycelia on V8 juice agar and produced a large amount of persistent and papillary ovoid sporangia with size of 22 ~ 45μm (average 31μm) × 18 ~ 39μm (average 23μm) in 10% aqueous solution of V8. The spore was spherical with thick-wall and diameter of 24 ± 3.9μm. The morphology of QS.1 is similar to that of Phytophthora nicotianae. The genomic DNA of representative isolate QS.1 was extracted from mycelium by a modified CTAB method (Murray et al. 1980). The rDNA internal transcribed spacer (ITS) region, β-tubulin and EF1-α genes were amplified and sequenced with primers ITS1/ITS4 (White et al. 1990), BTub_F1/TUBUR1 (L. et al. 2004) and EF1A_for/EF1A_rev (Blair et al. 2008), respectively. The BLAST results of these sequences (Accession No. MZ646302, MZ672116, and MZ675589, respectively) showed 99%, 100% and 100% identity with sequences of P. nicotianae (Accession No. KJ494902, KY205750, and MH359041), respectively. Based on the morphological characteristics and DNA analysis, isolate QS.1 was identified as P. nicotianae. To our best knowledge, this is the first report of P. nicotianae causing stem canker on Chinese Catalpa. This disease may pose potential threat on Catalpa due to the increase in Catalpa planting for economic and ecological purposes in China.


Buildings ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 457
Author(s):  
Alison Conroy ◽  
Phalguni Mukhopadhyaya ◽  
Guido Wimmers

The Wood Innovation Research Lab was designed as a low energy-use building to facilitate the construction and testing of engineered wood products by the faculty and staff of the Master of Engineering in Integrated Wood Design Program at the University of Northern British Columbia in Prince George, BC, Canada. Constructed using a 533 mm thick-wall and 659 mm flat roof assembly, it received certification as Canada’s first industrial facility built to the International Passive House standard. Temperature and humidity sensors were installed in the north and south exterior wall assemblies to measure long-term hygrothermal performance. Data collected between 2018–2020 shows no record of long-term moisture accumulation within the exterior assemblies. Data collected during this time period was used to validate hygrothermal performance models for the building created using the WUFI® Plus software. Long-term performance models created using future climate data for five cities across Canada under two global warming scenarios shows favorable results, with an increase in average annual temperatures resulting in lower average relative humidity values at the interior face of the exterior sheathing board in the exterior wall assemblies.


Author(s):  
Yunan Prawoto ◽  
Rachmad Imbang Trittjahjono

Thick-wall vessels and pipes cylindrical shape are very typical in power plant, chemical, processing, oil and gas industry. The equipment with cylindrical shape can be either thin or thick wall which depends on the function of that particular equipment. Typically, thick-wall cylinder is used when the equipment is needed to accommodate high pressure contents. Mostly, cracks appear either on the internal or external of a thick-wall cylinder. Primarily, when welding is applied in the fabrication of the thick-wall cylinder, cracks can easily appear due to solidification or hydrogen embrittlement at the welded joint, typically butt-welded joint. Hence, it is critical to examine the stress distribution along the crack and resolve the stress intensity factor of the cracks in both welded and non-welded internally pressurized thick-wall cylinder. Finite element analysis has been conducted using the engineering software, ABAQUS CAE to investigate the stress distribution and to perform the evaluation of stress intensity factor. Besides, weight function method has also been used by other researchers to determine the factor of stress intensity for both welded and non-welded thick-wall cylinder. The results were compared in terms of both of the methods applied. The last, the effect of the butt-welded joint profile in thick-wall cylinder has also been investigated.


2021 ◽  
Author(s):  
Ying Li ◽  
Deqiang Zhang ◽  
Yongfeng Lou ◽  
Xinmin An ◽  
Zhimin Gao

Primary thickening determines bamboo yield and wood property. However, little is known about the regulatory networks involved in this process. The present study identified a total of 58,652 genes and 521 miRNAs via transcriptome and small RNA sequencing using the underground thickening shoot samples of wild type (WT) Moso bamboo (Phyllostachys edulis) and a thick wall (TW) variant (P. edulis cv. Pachyloen) at five developmental stages (WTS1/TWS1-WTS5/TWS5). A total of 11,636 (54.05%) differentially expressed genes (DEGs) and 515 (98.85%) differentially expressed miRNAs (DEmiRs) were identified from the WT, TW, and WTTW groups. The first two groups were composed of four pairwise combinations each between two successive stages (WTS2/TWS2_vs_WTS1/TWS1, WTS3/TWS3_vs_WTS2/TWS2, WTS4/TWS4_vs_WTS3/TWS3 and WTS5/TWS5_vs_WTS4/TWS4), and the WTTW group was composed of five between two relative stages (TWS1-5_vs_WTS1-5). Additionally, among the phytohormones, zeatin (ZT) showed more remarkable changes in concentrations than indole-3-acetic acid (IAA), gibberellic acid (GA3), and abscisic acid (ABA) throughout the five stages in the WT and the TW groups. Moreover, 118 sites were identified for 590 miRNA-mRNA pairs via degradome sequencing. The dual-luciferase reporter assay confirmed that 14 miRNAs bound to 12 targets. Fluorescence in situ hybridization (FISH) localized miR166 and miR160 in the shoot apical meristem (SAM) and the procambium of Moso bamboo shoots at the S1 stage. Thus, primary thickening is a complex process regulated by miRNA-gene-phytohormone networks, and the miRNAome and transcriptome dynamics regulate phenotypic plasticity. These findings provide insights into the molecular mechanisms underlying wood formation and properties and propose targets for bamboo breeding.


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