Synthesis and properties of temperature-sensitive and chemically crosslinkable poly(ether-urethane) hydrogel

2015 ◽  
Vol 6 (19) ◽  
pp. 3671-3684 ◽  
Author(s):  
Ruizhi Li ◽  
Na Liu ◽  
Bingqiang Li ◽  
Yinong Wang ◽  
Guolin Wu ◽  
...  
Keyword(s):  
Uv Light ◽  
Temperature Sensitive ◽  
Physiological Temperature

The PEU-MA solutions can gelate at physiological temperature, and be further crosslinked by UV light.

Phase-Change Heat Transfer Measurements Using Temperature-Sensitive Paints

2017 ◽  
Vol 140 (3) ◽  
Author(s):  
Husain Al Hashimi ◽  
Caleb F. Hammer ◽  
Michel T. Lebon ◽  
Dan Zhang ◽  
Jungho Kim
Keyword(s):  
Heat Transfer ◽  
High Speed ◽  
Uv Light ◽  
Flow Boiling ◽  
Low Cost ◽  
Data Interpretation ◽  
Temperature Sensitive ◽  
Time Resolved ◽  
Light Emitting ◽  
Phase Change Heat Transfer

Techniques based on temperature-sensitive paints (TSP) to measure time-resolved temperature and heat transfer distributions at the interface between a wall and fluid during pool and flow boiling are described. The paints are excited using ultraviolet (UV) light emitting diodes (LEDs), and changes in fluorescence intensity are used to infer local temperature differences across a thin insulator from which heat flux distribution is obtained. Advantages over infrared (IR) thermometry include the ability to use substrates that are opaque to IR (e.g., glass, plexiglass and plastic films), use of low-cost optical cameras, no self-emission from substrates to complicate data interpretation, high speed, and high spatial resolution. TSP-based methods to measure wall heat transfer distributions are validated and then demonstrated for pool and flow boiling.

scholarly journals Incubation at the nonpermissive temperature induces deficiencies in UV resistance and mutagenesis in mouse mutant cells expressing a temperature-sensitive ubiquitin-activating enzyme (E1).

1997 ◽  
Vol 17 (3) ◽  
pp. 1484-1489 ◽  
Author(s):  
H Ikehata ◽  
S Kaneda ◽  
F Yamao ◽  
T Seno ◽  
T Ono ◽  
...  
Keyword(s):  
Dna Repair ◽  
Mammalian Cells ◽  
Uv Light ◽  
Temperature Sensitive ◽  
Restrictive Temperature ◽  
Nonpermissive Temperature ◽  
Conjugation System ◽  
Ubiquitin Conjugating Enzyme ◽  
Mutant Phenotypes ◽  
Mutant Cells

In temperature-sensitive (ts) mutants of mouse FM3A cells, the levels of mutagenesis and survival of cells treated with DNA-damaging agents have been difficult to assess because they are killed after their mutant phenotypes are expressed at the nonpermissive temperature. To avoid this difficulty, we incubated the ts mutant cells at the restrictive temperature, 39 degrees C, for only a limited period after inducing DNA damage. We used ts mutants defective in genes for ubiquitin-activating enzyme (E1), DNA polymerase alpha, and p34(cdc2) kinase. Whereas the latter two showed no effect, E1 mutants were sensitized remarkably to UV light if incubated at 39 degrees C for limited periods after UV exposure. Eighty-five percent of the sensitization occurred within the first 12 h of incubation at 39 degrees C, and more than 36 h at 39 degrees C did not produce any further sensitization. Moreover, while the 39 degrees C incubation gave E1 mutants a moderate spontaneous mutator phenotype, the same treatment significantly diminished the level of UV-induced 6-thioguanine resistance mutagenesis and extended the time necessary for expression of the mutation phenotype. These characteristics of E1 mutants are reminiscent of the defective DNA repair phenotypes of Saccharomyces cerevisiae rad6 mutants, which have defects in a ubiquitin-conjugating enzyme (E2), to which E1 is known to transfer ubiquitin. These results demonstrate the involvement of E1 in eukaryotic DNA repair and mutagenesis and provide the first direct evidence that the ubiquitin-conjugation system contributes to DNA repair in mammalian cells.

Temperature-sensitive mutants of bacteriophage SH-133 specific for the hydrogen bacterium Pseudomonas facilis: isolation, complementation, and partial characterization

1979 ◽  
Vol 25 (1) ◽  
pp. 86-93
Author(s):  
Christine M. Battreall ◽  
William E. Friedrichs ◽  
Jeffrey P. Reed ◽  
Gary M. Aron
Keyword(s):  
Uv Light ◽  
Temperature Sensitive ◽  
Permissive Temperature ◽  
Wild Type ◽  
Temperature Sensitive Mutants ◽  
Specific Phage ◽  
Autotrophic Metabolism ◽  
Complementation Groups ◽  
Type Phage ◽  
The Relationship

Seventeen temperature-sensitive mutants of bacteriophage SH-133 have been isolated following mutagenesis with UV-light, nitrosoguanidine, and ethyl methanesulfonate. The mutants were classified into 15 complementation groups according to their ability to complement each other at 32 °C, the nonpermissive temperature. Each mutant was studied with regard to the relationship between its ability to multiply in heterotrophically (H-) and autotrophically (A-) grown Pseudomonas facilis cells. At 27 °C, the permissive temperature, the plaque-forming ability of the 17 mutants and wild-type phage was reduced 10-fold in A-grown cells. At 32 °C, mutants belonging to 10 groups exhibited identical levels of multiplicity-dependent leak under both modes of growth. However, the infection of A-grown cells by mutants belonging to the remaining five groups resulted in as much as 500-fold inhibition of multiplicity-dependent leak when contrasted with the infection of cells grown heterotrophically. These observations indicate that the expression of five SH-133 phage cistrons is defective when multiplication proceeds under autotrophic metabolism. Seven mutants were found to differ from the wild-type phage with regard to thermal stability at 56 °C which suggests that they possess altered structural proteins. Four of the seven thermosensitive mutants exhibited reduced levels of multiplicity-dependent leak in A-grown cells. The data suggest that the reduction in plaque-forming ability of SH-133 in A-grown cells is caused by a defect in the expression of specific phage structural components.

scholarly journals pH and Temperature Thermosensitive for Modification of Cotton Fabric (A Review)

2021 ◽  
Vol 12 (2) ◽  
pp. 2216-2228
Keyword(s):  
Drug Release ◽  
Cotton Fabric ◽  
Delivery System ◽  
Medical Applications ◽  
Temperature Sensitive ◽  
Physiological Temperature ◽  
Responsive Hydrogels

Because of their unusual properties, Hydrogels have been one of the most exciting areas within the drug system. Responsive hydrogels gave the delivery system excellent spatial and temporal power with gelation at physiological temperature. In different medical applications such as sensors, drug release systems, and so on, SRHs have been used. Other fields such as practical textiles and clever garments also undergo active study. The research covers the use of biotherapy molecules in temperature-sensitive gel systems.

scholarly journals Mechanical and chemical resistance of thermochromic packaging prints

2020 ◽  
Author(s):  
Sonja Jamnicki Hanzer ◽  
◽  
Rahela Kulčar ◽  
Marina Vukoje ◽  
Petra Širol ◽  
...  
Keyword(s):  
Standard Method ◽  
Food Packaging ◽  
Visual Inspection ◽  
Chemical Resistance ◽  
Uv Light ◽  
Chemical Degradation ◽  
Temperature Sensitive ◽  
Severe Damage ◽  
Thermochromic Effect ◽  
Adverse Environmental Conditions

Thermochromic inks are temperature-sensitive materials that change colour due to a temperature change. These inks are mostly printed on smart packaging applications where they are used in a form of temperature indicators. The colorants in these inks are microencapsulated which makes the prints obtained with these inks more sensitive to abrasion in comparison to the prints obtained with conventional inks. Thermochromic prints are also very sensitive to adverse environmental conditions, such as exposure to UV light, heat and certain chemicals and solvents. Abrasion and chemical resistance of thermochromic prints obtained on metallized label papers are discussed in this paper. For that purpose, two thermochromic UV screen inks were printed on two types of metalized papers that are commonly used as food packaging labels. The prints thus obtained were then subjected to a rub test in accordance with standard method BS 3110. Rub test was performed using Hanatek RT4 Rub and Abrasion Tester. The degree of rubbing was assessed by visual inspection and by detection of the colorimetric changes on the prints after their exposure to rubbing. Assessment of prints' resistance to various liquid agents (water, ethanol and citric acid) was done in accordance to standard method ISO 2836. Evaluation of chemical degradation on prints was done by the spectrophotometric measurements. The results of conducted research showed good rub resistance of these inks, as no rubbing was detected, but poor resistance to all liquid agents they were exposed to. Exposure to ethanol, particularly, caused severe damage to the prints. The bleeding of the colorants from the prints was also detected. However, even though the prints were not able to completely withstand exposure to specific liquid agents which was demonstrated by their optical deterioration, the thermochromic effect was still present in them after resistance tests were conducted.

scholarly journals Signals from the stressed endoplasmic reticulum induce C/EBP-homologous protein (CHOP/GADD153).

1996 ◽  
Vol 16 (8) ◽  
pp. 4273-4280 ◽  
Author(s):  
X Z Wang ◽  
B Lawson ◽  
J W Brewer ◽  
H Zinszner ◽  
A Sanjay ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Damage ◽  
Endoplasmic Reticulum ◽  
Er Stress ◽  
Uv Light ◽  
Growth Arrest ◽  
Protein Glycosylation ◽  
Temperature Sensitive ◽  
Gene Encoding ◽  
Homologous Protein

The gene encoding C/EBP-homologous protein (CHOP), also known as growth arrest and DNA-damage-inducible gene 153 (GADD153), is activated by agents that adversely affect the function of the endoplasmic reticulum (ER). Because of the pleiotropic effects of such agents on other cellular processes, the role of ER stress in inducing CHOP gene expression has remained unclear. We find that cells with conditional (temperature-sensitive) defects in protein glycosylation (CHO K12 and BHK tsBN7) induce CHOP when cultured at the nonpermissive temperature. In addition, cells that are defective in initiating the ER stress response, because of overexpression of an exogenous ER chaperone, BiP/GRP78, exhibit attenuated inducibility of CHOP. Surprisingly, attenuated induction of CHOP was also noted in BiP-overexpressing cells treated with methyl methanesulfonate, an agent thought to activate CHOP by causing DNA damage. The roles of DNA damage and growth arrest in the induction of CHOP were therefore reexamined. Induction of growth arrest by culture to confluence or treatment with the enzymatic inhibitor N-(phosphonacetyl)-L-aspartate did not induce CHOP. Furthermore, both a DNA-damage-causing nucleoside analog (5-hydroxymethyl-2'-deoxyuridine) and UV light alone did not induce CHOP. These results suggest that CHOP is more responsive to ER stress than to growth arrest or DNA damage and indicate a potential role for CHOP in linking stress in the ER to alterations in gene expression.

scholarly journals Enhancement of alphavirus replication in mammalian cells at sub-physiological temperatures

2021 ◽  
Author(s):  
Jinchao Guo ◽  
Mark Harris
Keyword(s):  
Mammalian Cells ◽  
Chikungunya Virus ◽  
Stress Granules ◽  
Mammalian Host ◽  
Temperature Sensitive ◽  
Mosquito Vector ◽  
Structural Protein ◽  
Physiological Temperature ◽  
Mosquito Bite ◽  
Mosquito Cells

AbstractChikungunya virus (CHIKV) is a re-emerging Alphavirus transmitted by Aedes mosquitoes and causing fever, rash and arthralgia. Currently there are no vaccines or antiviral agents against CHIKV, therefore it is important to understand the molecular details of CHIKV replication. In this regard, the function of the Alphavirus non-structural protein 3 (nsP3) remains enigmatic. Building on previous studies (Gao et al, 2019), we generated a panel of mutants in a conserved and surface exposed cluster in the nsP3 alphavirus unique domain (AUD) and tested their replication phenotype using a sub-genomic replicon (SGR) in mammalian and mosquito cells. We identified three mutants that replicated poorly in mammalian cells but showed no defect in mosquito cells. We further showed that these mutants were temperature-sensitive, rather than species-specific, as they exhibited no replication defect in mammalian cells at sub-physiological temperature (28°C). Similar effects were observed in the context of infectious CHIKV as well as a closely related virus: O’Nyong Nyong virus (ONNV). Intriguingly, this analysis also revealed that the wildtype SGR replicated much more efficiently at sub-physiological temperature as compared to 37°C. This was not due to impaired interferon responses as this enhancement was also observed in Vero cells. Neither was this due to a defect in the phosphorylation of eIF2α as treatment with ISRIB, an inhibitor of global translation attenuation, did not compensate for replication defects at 37°C. However, we noticed significant differences between the sizes and numbers of virus-induced stress granules (SG) at physiological and sub-physiological temperatures. As cells in the periphery will be at sub-physiological temperatures, and these will be the first cells infected in the mammalian host following a mosquito bite, we propose that alphaviruses have evolved mechanisms to limit antiviral responses in these cells to promote viral genome replication.Author summaryChikungunya virus (CHIKV) is a re-emerging arbovirus. It is transmitted by Aedes species of mosquitos and poses massive epidemic threats. Arboviruses are unique in that they must be able to replicate efficiently in both the mosquito vector and the mammalian host, and therefore at different temperatures. Importantly, the first cells infected in the mammalian host following a mosquito bite will be in the skin and therefore at sub-physiological temperature (lower than 37°C). Here we show that mutants within one of the CHIKV proteins (nsP3) were unable to replicate at 37°C but replicated efficiently in mammalian cells at a sub-physiological temperature (28°C). We also showed that the wildtype virus replicated more efficiently at 28°C in comparison to at 37°C in mammalian cells. We investigated the mechanism behind this phenomenon and showed that at sub-physiological temperatures the virus induced the formation of smaller and more numerous cytoplasmic stress granules. We propose that alphaviruses have evolved mechanisms to promote their replication in mammalian cells at sub-physiological temperatures to facilitate infection of mammals via a cutaneous mosquito bite.

Oncogenesis and the Lucké Virus

1968 ◽  
Vol 26 ◽  
pp. 200-201
Author(s):  
A. E. Vatter ◽  
J. Zambernard
Keyword(s):  
Rna Viruses ◽  
Vegetative State ◽  
Temperature Sensitive ◽  
Structural Level ◽  
Oncogenic Viruses ◽  
Dna Viruses ◽  
Leopard Frogs ◽  
Renal Adenocarcinoma ◽  
Induced Tumors ◽  
Northern Leopard Frogs

Oncogenic viruses, like viruses in general, can be divided into two classes, those that contain deoxyribonucleic acid (DNA) and those that contain ribonucleic acid (RNA). The RNA viruses have been recovered readily from the tumors which they cause whereas, the DNA-virus induced tumors have not yielded the virus. Since DNA viruses cannot be recovered, the bulk of present day investigations have been concerned with RNA viruses.The Lucké renal adenocarcinoma is a spontaneous tumor which occurs in northern leopard frogs (Rana pipiens) and has received increased attention in recent years because of its probable viral etiology. This hypothesis was first advanced by Lucké after he observed intranuclear inclusions in some of the tumor cells. Tumors with inclusions were examined at the fine structural level by Fawcett who showed that they contained immature and mature virus˗like particles.The use of this system in the study of oncogenic tumors offers several unique features, the virus has been shown to contain DNA and it can be recovered from the tumor, also, it is temperature sensitive. This latter feature is of importance because the virus can be transformed from a latent to a vegetative state by lowering or elevating the environmental temperature.

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