primary wall
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Holzforschung ◽  
2019 ◽  
Vol 73 (12) ◽  
pp. 1121-1123
Author(s):  
Mihály Bariska ◽  
Zoltán Pásztory ◽  
Zoltán Börcsök

Abstract A study of tylosis in European Turkey oak (Quercus cerris L.) shows correspondences in the formation of tyloses and of regular cell walls. The outer tylosis wall has a smooth, granular surface with simple perforations analogous to that of the primary wall of ordinary cells. The underlying wall stratum shows parallel oriented macro-fibrils, normally found in the secondary walls of regular cells. At the contact areas of tyloses, stabilizing seams can be observed. Various types of wall openings such as simple pits, blind pits and vestured pits were present. Also tylosis division was detected. The characteristics of parenchyma cell walls can be re-discovered in tyloses.


Author(s):  
I Ketut Putra ◽  
Ida Bagus Made Suryatika ◽  
I Gusti Agung Ayu Ratnawati ◽  
Gusti Ngurah Sutapa

One source of radiation is X-ray aircraft, which utilization must pay attention to safety aspects. Room design is the first step that must be done before the operation of X-ray aircraft. Radiology Unit Kasih Ibu Kedonganan Hospital operates an X-ray aircraft with specifications of 250 kV-85 mA, needs to be tested for radiation exposure which is an integral part of the verification of radiation protection. Test for radiation exposure at least once a year. The purpose of the installation room design is to ensure that workers or the general public around the plant receive radiation exposure that is smaller than the applicable dose limit value (DLV), by the radiation safety provisions that refer to the Decree. BAPETEN No. 7 of 2009 concerning Radiation Safety in the use of radiographic equipment. This study will test exposure to room wall shields associated with radiation workers and the general public. The results showed that all walls A, B, C, D, and E could still completely weaken the rate of X-ray radiation. The highest radiation dose detected on wall B is the primary wall for the Buky stand examination.


Development ◽  
2019 ◽  
Vol 146 (10) ◽  
pp. dev179036 ◽  
Author(s):  
Arun Sampathkumar ◽  
Alexis Peaucelle ◽  
Miki Fujita ◽  
Christoph Schuster ◽  
Staffan Persson ◽  
...  

2018 ◽  
Vol 115 (27) ◽  
pp. E6366-E6374 ◽  
Author(s):  
Yoichiro Watanabe ◽  
Rene Schneider ◽  
Sarah Barkwill ◽  
Eliana Gonzales-Vigil ◽  
Joseph L. Hill ◽  
...  

In plants, plasma membrane-embedded CELLULOSE SYNTHASE (CESA) enzyme complexes deposit cellulose polymers into the developing cell wall. Cellulose synthesis requires two different sets of CESA complexes that are active during cell expansion and secondary cell wall thickening, respectively. Hence, developing xylem cells, which first undergo cell expansion and subsequently deposit thick secondary walls, need to completely reorganize their CESA complexes from primary wall- to secondary wall-specific CESAs. Using live-cell imaging, we analyzed the principles underlying this remodeling. At the onset of secondary wall synthesis, the primary wall CESAs ceased to be delivered to the plasma membrane and were gradually removed from both the plasma membrane and the Golgi. For a brief transition period, both primary wall- and secondary wall-specific CESAs coexisted in banded domains of the plasma membrane where secondary wall synthesis is concentrated. During this transition, primary and secondary wall CESAs displayed discrete dynamic behaviors and sensitivities to the inhibitor isoxaben. As secondary wall-specific CESAs were delivered and inserted into the plasma membrane, the primary wall CESAs became concentrated in prevacuolar compartments and lytic vacuoles. This adjustment in localization between the two CESAs was accompanied by concurrent decreased primary wall CESA and increased secondary wall CESA protein abundance. Our data reveal distinct and dynamic subcellular trafficking patterns that underpin the remodeling of the cellulose biosynthetic machinery, resulting in the removal and degradation of the primary wall CESA complex with concurrent production and recycling of the secondary wall CESAs.


2015 ◽  
Vol 21 (5) ◽  
pp. 1304-1313 ◽  
Author(s):  
Jianfeng Ma ◽  
Xunli Lv ◽  
Shumin Yang ◽  
Genlin Tian ◽  
Xing’e Liu

AbstractStructural organization of the plant cell wall is a key parameter for understanding anisotropic plant growth and mechanical behavior. Four imaging platforms were used to investigate the cell wall architecture ofMiscanthus sinensiscv. internode tissue. Using transmission electron microscopy with potassium permanganate, we found a great degree of inhomogeneity in the layering structure (4–9 layers) of the sclerenchymatic fiber (Sf). However, the xylem vessel showed a single layer. Atomic force microscopy images revealed that the cellulose microfibrils (Mfs) deposited in the primary wall of the protoxylem vessel (Pxv) were disordered, while the secondary wall was composed of Mfs oriented in parallel in the cross and longitudinal section. Furthermore, Raman spectroscopy images indicated no variation in the Mf orientation of Pxv and the Mfs in Pxv were oriented more perpendicular to the cell axis than that of Sfs. Based on the integrated results, we have proposed an architectural model of Pxv composed of two layers: an outermost primary wall composed of a meshwork of Mfs and inner secondary wall containing parallel Mfs. This proposed model will support future ultrastructural analysis of plant cell walls in heterogeneous tissues, an area of increasing scientific interest particularly for liquid biofuel processing.


2013 ◽  
Vol 873 ◽  
pp. 257-266
Author(s):  
Yi Ying Luo ◽  
Xiao Yan Wu ◽  
Yi Xiang ◽  
Zhi Rong Niu

Experiments are performed aiming at the hot summer and cold winter area climate characteristics. The BWNH-3021 type weather-resistant testing apparatus is used to achieve performances of foam glass exterior thermal insulation walls. Real-time temperatures of each functional layer are tested under hot rain cycle effect. The temperature curves are plotted to make comparisons. When the environment temperature rises about 60°C, the temperatures of primary wall will rise only 8.20°C9.30°C each in 1#2# testing wall. When cold water is suddenly sprayed, the environment temperature will fall about 51°C. Then the temperatures of primary wall will fall only 4.00°C4.20°C each in 1#2# testing wall. It shows the good thermal insulating property of foam glass exterior thermal insulation wall. The environment temperature fluctuation can also be eliminated significantly. Attenuation coefficients of different thermal insulation walls are calculated. The maximum attenuation coefficients are present when temperature is rising. The coefficients of 1#2# testing wall are 15.00 and 4.60 separately. And the delay-times of two walls are 148min133min respectively. Both of the total attenuation coefficient and delay-time of 1# wall are greater than those of 2# wall. It indicates that a thicker layer makes the temperature wave decays more and takes longer time to delay. It proved that a thicker external thermal insulation structural layer contributes to the resistance of temperature fluctuation and thermal stability.


2012 ◽  
Vol 24 (6) ◽  
pp. 2624-2634 ◽  
Author(s):  
Shoko Hongo ◽  
Kaori Sato ◽  
Ryusuke Yokoyama ◽  
Kazuhiko Nishitani

2011 ◽  
Vol 99-100 ◽  
pp. 664-675
Author(s):  
Fu Liang Mei ◽  
Gui Ling Li

In this dissertation, the mathematical models of thermal conduction procedure and thermal deformation for an insulated composite wall are established. That thermal conduction model takes complicately environmental changes (such as solar radiation, building self-radiation, reflecting ground radiation, air temperature, outdoor heat convection and indoor heat convection) into account. The thermal conduction problem is solved using finite difference method on spatial domain and DIPIM on time domain respectively. Computational formulae of thermal stress are deduced based on theory of thermal elasticity and plane section assumption. Finally, both the hourly temperature field and the thermal stress for an exteriorly and an interiorly insulated composite wall within a typical day of winter and summer are analyzed. Computational results show although the exterior insulation system is more beneficial to the stability of primary wall than interior one, the effect of environmental changes on mortar cracking and decorative materials inside the exteriorly insulated system than that inside the interiorly insulated system. The temperature gradient inside the insulated lamination is bigger than that in other laminations for any insulated system within whether winter or summer. In addition, the temperature gradient inside the insulated lamination for the interiorly insulated system within winter is bigger than that within summer, but the temperature gradient inside the insulated lamination for the interiorly insulated system within summer is bigger than that within winter. Although the exteriorly insulated system is more beneficial to the stability of primary wall than the interiorly insulated, the effect of environmental changes on mortar cracking and decorative materials for the exteriorly insulated system is bigger than that for the interiorly insulated. An exteriorly insulated system is more beneficial to the primary wall than an interiorly insulated system according to environmental attacks on the primary wall.


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