A Novel Approach to Crosslink Delay of Low-pH Fracturing Fluid

2015 ◽  
Author(s):  
Magnus Legemah ◽  
Hong Sun ◽  
Paul Carman ◽  
John Mayor
Keyword(s):  
Low Ph ◽  
Fracturing Fluid ◽  
Novel Approach

Development and Field Application of a Low pH, Efficient Fracturing Fluid for Tight Gas Fields in the Greater Green River Basin, Wyoming

2009 ◽  
Vol 24 (04) ◽  
pp. 602-610 ◽  
Author(s):  
D.V. Satya Gupta ◽  
Terry L. Jackson ◽  
Gary J. Hlavinka ◽  
James B. Evans ◽  
Hoang V. Le ◽  
...  
Keyword(s):  
River Basin ◽  
Low Ph ◽  
Field Application ◽  
Tight Gas ◽  
Fracturing Fluid ◽  
Green River Basin ◽  
Green River ◽  
Gas Fields

The Future of Fracture Acidizing: A Low pH, Robust, and Residue-Free Crosslinked Fracturing Fluid

2016 ◽  
Author(s):  
Ibrahim Abdullah Al-Hulail ◽  
Prasad Karadkar ◽  
Yahya Hassan Al-Janabi ◽  
Haidr Al-Khabaz ◽  
Mohamed Khalifa
Keyword(s):  
Low Ph ◽  
Fracturing Fluid ◽  
The Future

Development and Field Application of a Low pH, Efficient Fracturing Fluid for Tight Gas Fields in the Greater Green River Basin, Wyoming

2008 ◽  
Author(s):  
D.V. Satya Gupta ◽  
Terry Lee Jackson ◽  
Gary J. Hlavinka ◽  
James Bernard Evans ◽  
Hoang Van Le ◽  
...  
Keyword(s):  
River Basin ◽  
Low Ph ◽  
Field Application ◽  
Tight Gas ◽  
Fracturing Fluid ◽  
Green River Basin ◽  
Green River ◽  
Gas Fields

Development and Field Application of a Low-pH, Efficient Fracturing Fluid for Western Siberian Oil and Gas Wells

2008 ◽  
Author(s):  
D.V. Satya Gupta ◽  
Hoang Van Le ◽  
Alexander Batrashkin ◽  
Pavel Nickolaevich Nevsky
Keyword(s):  
Oil And Gas ◽  
Low Ph ◽  
Field Application ◽  
Gas Wells ◽  
Fracturing Fluid ◽  
Oil And Gas Wells

Cell Function, Viability, and Icodextrin

1994 ◽  
Vol 14 (2_suppl) ◽  
pp. 28-32 ◽  
Author(s):  
Nicholas Topley ◽  
Tomasz Liberek ◽  
Chandra Mistry ◽  
Gerald A. Coles ◽  
John D. Williams
Keyword(s):  
Molecular Weight ◽  
Cell Function ◽  
Inhibitory Effect ◽  
Low Ph ◽  
Laboratory Setting ◽  
Novel Approach ◽  
Glucose Polymer ◽  
Per Se ◽  
Dialysis Fluids ◽  
High Lactate

The bioincompatibility of conventional dialysis fluids is related primarily to the combination of low pH and high lactate concentrations. This results in the reduction of intracellular pH and a consequent inhibition of cell function. The use of high glucose concentrations to increase fluid osmolality adds to the cytotoxicity and has a further inhibitory effect on peritoneal cells. The clinical need for fluids that provide sustained ultrafiltration has led to a novel approach using a high molecular weight glucose polymer (icodextrin) to generate an ultrafiltration gradient in an iso-osmolar fluid. In the studies presented we have had the opportunity of examining, in the laboratory setting, the biocompatibility of such a fluid. As in previous studies with conventional fluids, pH per se has a profound effect on most modalities of cell function. In addition, there appearto be a few areas where problems can be ascribed to icodextrin itself. Furthermore, it is possible that Staph. epidermidis survives better in icodextrin than in conventional dialysate. Whether the benefits of sustained ultrafiltration outweigh the possible disadvantages outlined can only be judged when the results from ongoing clinical trials are available.

scholarly journals Investigation of Fatty Acid Ketohydrazone Modified Liposome’s Properties as a Drug Carrier

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Keita Hayashi ◽  
Madoka Kiriishi ◽  
Keishi Suga ◽  
Yukihiro Okamoto ◽  
Hiroshi Umakoshi
Keyword(s):  
Drug Carrier ◽  
Acyl Chain ◽  
Low Ph ◽  
Endocytic Pathway ◽  
Membrane Properties ◽  
The Novel ◽  
Ph Responsive ◽  
Novel Approach ◽  
Ph Conditions ◽  
Dmpc Liposome

pH-responsive liposomes were prepared by modifying the liposome with acid-cleaving amphiphiles. Palmitic ketohydrazone (P-KH) or stearic ketohydrazone (S-KH), composed of hydrophilic sugar headgroup and hydrophobic acyl chain, was used as a modifier of the DMPC liposome. Because the ketohydrazone group of P-KH or S-KH was cleaved at low pH conditions (<pH 5.0), the delivery of the P-KH modified liposomes was observed probably via an endocytic pathway. The membrane properties of these liposomes were characterized, focusing on the variation of both polarity (measured by Laurdan) and membrane fluidity (measured by DPH) at low pH condition. The interface of the P-KH modified liposome at acidic pH was found to become more hydrophobic and less fluidic as compared with that at neutral pH; that is, P-KH modified liposome became more rigid structure. Therefore, it seems that the P-KH modified liposome could protect encapsulated drugs from the enzymes in the lysosome. This study shows the novel approach about design of pH-responsive liposomes based on the membrane properties.

Relationship between golgi apparatus and axonal reticulum in sympathetic ganglion cells

1978 ◽  
Vol 36 (2) ◽  
pp. 598-599
Author(s):  
J. Quatacker ◽  
W. De Potter
Keyword(s):  
Golgi Apparatus ◽  
Sympathetic Ganglion ◽  
Phosphotungstic Acid ◽  
Ganglion Cells ◽  
Low Ph ◽  
Dense Core ◽  
Dense Core Vesicles ◽  
Large Dense Core Vesicles ◽  
Cervical Ganglia ◽  
Axoplasmic Reticulum

Mucopolysaccharides have been demonstrated biochemically in catecholamine-containing subcellular particles in different rat, cat and ox tissues. As catecholamine-containing granules seem to arise from the Golgi apparatus and some also from the axoplasmic reticulum we examined wether carbohydrate macromolecules could be detected in the small and large dense core vesicles and in structures related to them. To this purpose superior cervical ganglia and irises from rabbit and cat and coeliac ganglia and their axons from dog were subjected to the chromaffin reaction to show the distribution of catecholamine-containing granules. Some material was also embedded in glycolmethacrylate (GMA) and stained with phosphotungstic acid (PTA) at low pH for the detection of carbohydrate macromolecules.The chromaffin reaction in the perikarya reveals mainly large dense core vesicles, but in the axon hillock, the axons and the terminals, the small dense core vesicles are more prominent. In the axons the small granules are sometimes seen inside a reticular network (fig. 1).

Copper-dependent ATP7B up-regulation drives the resistance of TMEM16A-overexpressing head-and-neck cancer models to platinum toxicity

2019 ◽  
Vol 476 (24) ◽  
pp. 3705-3719 ◽  
Author(s):  
Avani Vyas ◽  
Umamaheswar Duvvuri ◽  
Kirill Kiselyov
Keyword(s):  
Oxidative Stress ◽  
Head And Neck ◽  
Transcriptional Activation ◽  
Platinum Resistance ◽  
Mrna Levels ◽  
Strong Positive Correlation ◽  
Platinum Compounds ◽  
Copper Chelation ◽  
Novel Approach ◽  
Cancer Models

Platinum-containing drugs such as cisplatin and carboplatin are routinely used for the treatment of many solid tumors including squamous cell carcinoma of the head and neck (SCCHN). However, SCCHN resistance to platinum compounds is well documented. The resistance to platinum has been linked to the activity of divalent transporter ATP7B, which pumps platinum from the cytoplasm into lysosomes, decreasing its concentration in the cytoplasm. Several cancer models show increased expression of ATP7B; however, the reason for such an increase is not known. Here we show a strong positive correlation between mRNA levels of TMEM16A and ATP7B in human SCCHN tumors. TMEM16A overexpression and depletion in SCCHN cell lines caused parallel changes in the ATP7B mRNA levels. The ATP7B increase in TMEM16A-overexpressing cells was reversed by suppression of NADPH oxidase 2 (NOX2), by the antioxidant N-Acetyl-Cysteine (NAC) and by copper chelation using cuprizone and bathocuproine sulphonate (BCS). Pretreatment with either chelator significantly increased cisplatin's sensitivity, particularly in the context of TMEM16A overexpression. We propose that increased oxidative stress in TMEM16A-overexpressing cells liberates the chelated copper in the cytoplasm, leading to the transcriptional activation of ATP7B expression. This, in turn, decreases the efficacy of platinum compounds by promoting their vesicular sequestration. We think that such a new explanation of the mechanism of SCCHN tumors’ platinum resistance identifies novel approach to treating these tumors.

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