scholarly journals THE EFFECT OF LOW TEMPERATURE ON THE DEVELOPMENT OF THE LAMELLAR SYSTEM IN CHLOROPLASTS

1960 ◽  
Vol 8 (2) ◽  
pp. 529-538 ◽  
Author(s):  
Shimon Klein
Keyword(s):  
Low Temperature ◽  
Normal Development ◽  
Tap Water ◽  
Prolamellar Body ◽  
Lamellar System ◽  
Submicroscopic Structure ◽  
Ring Structures ◽  
In Situ Absorption ◽  
The One

The influence of low temperature (3°C.) on development of submicroscopic structure in plastids of Zea m. leaves was studied. Leaves from 8-day old etiolated plants, with plastids showing the prolamellar body and few lamellae, were floated for 1 day on tap water both in the dark and in the light, at 26°C and at 3°C. The structures remain unchanged in the dark, independent of temperature. Whereas in the light at 26°C., normal development of parallel compound lamellae and formation of grana occurs, in light at 3°C. ring structures are formed. Under the latter conditions protochlorophyll is converted to chlorophyll, although the in situ absorption maximum is different from the one for chlorophyll in plants grown in light at 26°C. When leaves were transferred from light at 3°C. to light at 26°C., ring structures in the plastids disappeared and normal development occurred. The possibility is discussed that development of parallel-arranged compound lamellae is due both to photochemical and synthetic processes, involving not only accumulation of chlorophyll, but also synthesis of other compounds.

scholarly journals FINE STRUCTURE AND PIGMENT CONVERSION IN ISOLATED ETIOLATED PROPLASTIDS

1961 ◽  
Vol 11 (2) ◽  
pp. 433-440 ◽  
Author(s):  
Shimon Klein ◽  
A. Poljakoff-Mayber
Keyword(s):  
Fine Structure ◽  
Photosynthetic Apparatus ◽  
Prolamellar Body ◽  
Submicroscopic Structure ◽  
Outer Membranes ◽  
Prolamellar Bodies ◽  
Bean Plants ◽  
Isolation Methods

Proplastids containing a prolamellar body were isolated from leaves of etiolated bean plants. The isolation methods do not necessarily lead to destruction of their submicroscopic structure and most of the isolated proplastids show well preserved outer membranes, lamellar strands, and the prolamellar body. Morphological intactness of the proplastids varies; certain leaf fractions contain single prolamellar bodies as well as proplastids. Since pellets after centrifugation between 350 g and 1000 to 3000 g contain intact proplastids and, as was shown by quantitative experiments, the same fractions show photoconversion of protochlorophyll to chlorophyll, it is supposed that the isolated particles probably retain many of the properties which are characteristic of them in situ. Isolated proplastids may thus be a valuable tool in investigations on the development of the photosynthetic apparatus.

scholarly journals Interplay between ER Exit Code and Domain Conformation in CFTR Misprocessing and Rescue

2010 ◽  
Vol 21 (4) ◽  
pp. 597-609 ◽  
Author(s):  
Gargi Roy ◽  
Elaine M. Chalfin ◽  
Anita Saxena ◽  
Xiaodong Wang
Keyword(s):  
Low Temperature ◽  
Limited Proteolysis ◽  
Transmembrane Conductance Regulator ◽  
Wild Type ◽  
Transmembrane Conductance ◽  
The One ◽  
Cystic Fibrosis Transmembrane ◽  
Clear Change ◽  
Level Of Processing

Multiple mutations in cystic fibrosis transmembrane conductance regulator (CFTR) impair its exit from the endoplasmic reticulum (ER). We compared two processing mutants: ΔF508 and the ER exit code mutant DAA. Although both have severe kinetic processing defect, DAA but not ΔF508 has substantial accumulation in its mature form, leading to higher level of processing at the steady state. DAA has much less profound conformational abnormalities. It has lower Hsp70 association and higher post-ER stability than ΔF508. The ER exit code is necessary for ΔF508 residual export and rescue. R555K, a mutation that rescues ΔF508 misprocessing, improves Sec24 association and enhances its post-ER stability. Using in situ limited proteolysis, we demonstrated a clear change in trypsin sensitivity in ΔF508 NBD1, which is reversed, together with that of other domains, by low temperature, R555K or both. We observed a conversion of the proteolytic pattern of DAA from the one resembling ΔF508 to the one similar to wild-type CFTR during its maturation. Low temperature and R555K are additive in improving ΔF508 conformational maturation and processing. Our data reveal a dual contribution of ER exit code and domain conformation to CFTR misprocessing and underscore the importance of conformational repair in effective rescue of ΔF508.

In situ low-temperature Raman studies of iodine molecules confined in the one-dimensional channels of AlPO 4 -5 crystals

2016 ◽  
Vol 221 ◽  
pp. 76-80 ◽  
Author(s):  
Shuanglong Chen ◽  
Ye Yuan ◽  
Xigui Yang ◽  
Mingrun Du ◽  
Zhaodong Liu ◽  
...  
Keyword(s):  
Low Temperature ◽  
One Dimensional ◽  
The One

An In-Situ Post Growth Annealing Process for the Improvement of 4H-SiC/SiO2 MOS Interface Prepared by CVD Using TEOS, and its Characteristic Study

2005 ◽  
Vol 483-485 ◽  
pp. 681-684
Author(s):  
Kumaresan Ramanujam ◽  
Hidetsugu Furuichi ◽  
Koshi Taguchi ◽  
Satoshi Yukumoto ◽  
Shigehiro Nishino
Keyword(s):  
Low Temperature ◽  
High Performance ◽  
Semiconductor Device ◽  
Oxide Semiconductor ◽  
Interface Properties ◽  
Amorphous Sio2 ◽  
Interface Quality ◽  
N2 Atmosphere ◽  
The One

Investigations were carried out to achieve high performance Silicon Carbide Metal-Oxide-Semiconductor device structures. 4H-SiC/SiO2 interface was prepared by growing amorphous SiO2 layers by an alternate low temperature atmospheric CVD technique using TEOS as source material and the interface properties were compared with the one prepared by conventional thermal oxidation technique. The low temperature CVD technique offered the improvement of the interface properties with reduced Dit in comparison with thermally oxidized interface. As a new attempt, an in situ post growth annealing technique in N2 atmosphere was carried out to reduce the Dit further. Both the CVD technique and the in situ annealing processes that were used in the present study have been identified to be potential approaches to improve the interface quality.

In situ Tensile Experiments at Low Temperatures on Niobium Single Crystals by H.V.E.M.

1975 ◽  
Vol 33 ◽  
pp. 58-59
Author(s):  
F. H. Louchet ◽  
L. P. Kubin
Keyword(s):  
Electron Microscope ◽  
Transition Temperature ◽  
Low Temperature ◽  
Slip System ◽  
Low Temperatures ◽  
Tensile Axis ◽  
Image Intensifier ◽  
Screw Dislocations ◽  
Source Operation

Experiments have been carried out on the 3 MeV electron microscope in Toulouse. The low temperature straining holder has been previously described Images given by an image intensifier are recorded on magnetic tape.The microtensile niobium samples are cut in a plane with the two operative slip directions [111] and lying in the foil plane. The tensile axis is near [011].Our results concern:- The transition temperature of niobium near 220 K: at this temperature and below an increasing difference appears between the mobilities of the screw and edge portions of dislocations loops. Source operation and interactions between screw dislocations of different slip system have been recorded.

Role of boundaries in the crystallization of amorphous films

1988 ◽  
Vol 46 ◽  
pp. 626-627
Author(s):  
D. A. Smith
Keyword(s):  
Low Temperature ◽  
Amorphous State ◽  
Nucleation And Growth ◽  
Amorphous Films ◽  
Island Nucleation ◽  
Surface Steps ◽  
Transmission Electron ◽  
Component Systems ◽  
Temperature Deposition

The nucleation and growth processes which lead to the formation of a thin film are particularly amenable to investigation by transmission electron microscopy either in situ or subsequent to deposition. In situ studies have enabled the observation of island nucleation and growth, together with addition of atoms to surface steps. This paper is concerned with post-deposition crystallization of amorphous alloys. It will be argued that the processes occurring during low temperature deposition of one component systems are related but the evidence is mainly indirect. Amorphous films result when the deposition conditions such as low temperature or the presence of impurities (intentional or unintentional) preclude the atomic mobility necessary for crystallization. Representative examples of this behavior are CVD silicon grown below about 670°C, metalloids, such as antimony deposited at room temperature, binary alloys or compounds such as Cu-Ag or Cr O2, respectively. Elemental metals are not stable in the amorphous state.

CBED study of low-temperature InP grown by gas source MBE

1993 ◽  
Vol 51 ◽  
pp. 810-811
Author(s):  
R. Rajesh ◽  
M.J. Kim ◽  
J.S. Bow ◽  
R.W. Carpenter ◽  
G.N. Maracas
Keyword(s):  
Low Temperature ◽  
Second Phase ◽  
Material System ◽  
Ion Milling ◽  
Electrical Measurements ◽  
Gas Source ◽  
Structural And Electrical Properties ◽  
The One ◽  
Lt Inp ◽  
Gas Source Mbe

In our previous work on MBE grown low temperature (LT) InP, attempts had been made to understand the relationships between the structural and electrical properties of this material system. Electrical measurements had established an enhancement of the resistivity of the phosphorus-rich LT InP layers with annealing under a P2 flux, which was directly correlated with the presence of second-phase particles. Further investigations, however, have revealed the presence of two fundamentally different types of precipitates. The first type are the surface particles, essentially an artefact of argon ion milling and containing mostly pure indium. The second type and the one more important to the study are the dense precipitates in the bulk of the annealed layers. These are phosphorus-rich and are believed to contribute to the improvement in the resistivity of the material.The observation of metallic indium islands solely in the annealed LT layers warranted further study in order to better understand the exact reasons for their formation.

The study of Apara (placenta) and its correlation with the Prakriti and Weight of newborn

2017 ◽  
Vol 2 (05) ◽  
Author(s):  
Apurva Dhakulkar ◽  
Sachin Khedikar
Keyword(s):  
Basic Concept ◽  
Normal Development ◽  
Unique Contribution ◽  
Multiple Functions ◽  
Intrauterine Life ◽  
Foetal Growth ◽  
Healthy Pregnancy ◽  
The One

The placenta is the most important and the only organ between mother and foetus serving multiple functions like endocrinal, respiratory and metabolic. Normal development of the placenta is the one of the important requirements for a healthy pregnancy, regulating foetal growth and foetal health so that formation of the healthy progeny. In cotemporary sciences many researches are going in the aim of formation of healthy progeny. Apara is the vital feature related to Garbha Sharira in Ayurveda, but its description is in a Sutra form. Hence this study is an humble attempt to explore the concept of ‘Ayurveda Garbha Sharira’ by studying the description of Apara trying to establishment of the assessment of correlation between features of placenta with that of Prakriti is more instinct for this study. Prakriti is the basic concept of Ayurveda. It forms in intrauterine life by combination of Shukra and Shonita. However we do not find direct references of Apara relation with the Prakriti of newborn in Ayurveda. This study intends to fill in the lacunae of both the disciplines by knowledge of integration. If this study establishes some parameters based on the characteristics of Apara with weight and Prakriti of newborn then it will be the unique contribution for Ayurveda Garbha Sharira.

scholarly journals Insight into the Promoting Role of Er Modification on SO2 Resistance for NH3-SCR at Low Temperature over FeMn/TiO2 Catalysts

Catalysts ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 618
Author(s):  
Huan Du ◽  
Zhitao Han ◽  
Xitian Wu ◽  
Chenglong Li ◽  
Yu Gao ◽  
...  
Keyword(s):  
Low Temperature ◽  
Catalyst Surface ◽  
Impregnation Method ◽  
In Situ Drifts ◽  
Tio2 Catalyst ◽  
Nh3 Scr ◽  
Nh3 Adsorption ◽  
So2 Resistance ◽  
Fast Scr

Er-modified FeMn/TiO2 catalysts were prepared through the wet impregnation method, and their NH3-SCR activities were tested. The results showed that Er modification could obviously promote SO2 resistance of FeMn/TiO2 catalysts at a low temperature. The promoting effect and mechanism were explored in detail using various techniques, such as BET, XRD, H2-TPR, XPS, TG, and in-situ DRIFTS. The characterization results indicated that Er modification on FeMn/TiO2 catalysts could increase the Mn4+ concentration and surface chemisorbed labile oxygen ratio, which was favorable for NO oxidation to NO2, further accelerating low-temperature SCR activity through the “fast SCR” reaction. As fast SCR reaction could accelerate the consumption of adsorbed NH3 species, it would benefit to restrain the competitive adsorption of SO2 and limit the reaction between adsorbed SO2 and NH3 species. XPS results indicated that ammonium sulfates and Mn sulfates formed were found on Er-modified FeMn/TiO2 catalyst surface seemed much less than those on FeMn/TiO2 catalyst surface, suggested that Er modification was helpful for reducing the generation or deposition of sulfate salts on the catalyst surface. According to in-situ DRIFTS the results of, the presence of SO2 in feeding gas imposed a stronger impact on the NO adsorption than NH3 adsorption on Lewis acid sites of Er-modified FeMn/TiO2 catalysts, gradually making NH3-SCR reaction to proceed in E–R mechanism rather than L–H mechanism. DRIFTS.

scholarly journals NIR responsive tumor vaccine in situ for photothermal ablation and chemotherapy to trigger robust antitumor immune responses

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Lirong Zhang ◽  
Jingjing Zhang ◽  
Lixia Xu ◽  
Zijian Zhuang ◽  
Jingjin Liu ◽  
...  
Keyword(s):  
Immune Responses ◽  
Tumor Vaccine ◽  
Oxidative Polymerization ◽  
Delivery Mode ◽  
Tumor Treatment ◽  
One Pot ◽  
Photothermal Ablation ◽  
Prolonged Retention ◽  
The One

Abstract Background Therapeutic tumor vaccine (TTV) that induces tumor-specific immunity has enormous potentials in tumor treatment, but high heterogeneity and poor immunogenicity of tumor seriously impair its clinical efficacy. Herein, a novel NIR responsive tumor vaccine in situ (HA-PDA@IQ/DOX HG) was prepared by integrating hyaluronic acid functionalized polydopamine nanoparticles (HA-PDA NPs) with immune adjuvants (Imiquimod, IQ) and doxorubicin (DOX) into thermal-sensitive hydrogel. Results HA-PDA@IQ NPs with high photothermal conversion efficiency (41.2%) and T1-relaxation efficiency were using HA as stabilizer by the one-pot oxidative polymerization. Then, HA-PDA@IQ loaded DOX via π-π stacking and mixed with thermal-sensitive hydrogel to form the HA-PDA@IQ/DOX HG. The hydrogel-confined delivery mode endowed HA-PDA@IQ/DOX NPs with multiple photothermal ablation performance once injection upon NIR irradiation due to the prolonged retention in tumor site. More importantly, this mode enabled HA-PDA@IQ/DOX NPs to promote the DC maturation, memory T cells in lymphatic node as well as cytotoxic T lymphocytes in spleen. Conclusion Taken together, the HA-PDA@IQ/DOX HG could be served as a theranostic tumor vaccine for complete photothermal ablation to trigger robust antitumor immune responses.

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